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  • 1
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    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/22997 | 19325 | 2018-03-05 09:06:04 | 22997 | Fisheries Society of Nigeria
    Publication Date: 2021-07-12
    Description: Studies on the effects of crude oil and its fractions on the blood haemoglobin (HB) neutrophil (NP) concentration in the blood of Heterobranchus bidorsalis juveniles were carried out. Two study periods (toxicity and recovery) and four oil types (Bonny-light crude oil (BLCO), premium motor spirit (PMS), kerosene (DPK) and lubricating engine oil (lBO) at 1.00, 2.00, 4.00 and 8.00ml were used. There were significant differences (P〈0.05, p〈 0.01) on the HB and NP values in blood of fish samples. The elevated values of HB levels in fish exposed to 2.00,4.00 and 8.00m1 L-1 BLCC, 2.00ml L-1 PMS and DPK; and 4.00ml L -1 LBO over the levels in the control fish were in consonance with the results of other workers. Increases in NP values in fish exposed to the four oil types (BLCO, PMS, DKP and LBO) relative to the control could be part of the immunological attempts by the fish to mobilize the body's defence mechanisms. The relatively high percent mortality and low survival of H. bidorsalis juveniles exposed to 4.00 and 8.00mlL-1 concentration of the four oil types over the other concentration implied that these concentrations were probably lethal to fish existence.
    Description: Includes:- 4 tables.;23 refs.
    Keywords: Fisheries ; Health ; Pollution ; Heterobranchus bidorsalis ; Nigeria ; Delta State ; freshwater environment ; Crude oil ; Fish ; Toxicity ; Haemoglobins ; Lethal effects
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    Format: 152 - 159
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  • 2
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    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/23040 | 19325 | 2018-03-05 20:36:36 | 23040 | Fisheries Society of Nigeria
    Publication Date: 2021-07-12
    Description: The growth performance and nutrient utilization in Clarias gariepinus fingerlings fed cooked breadfruit (Artocarpus altilis) seed meal based diet as a replacement for maize, investigated for 8 weeks. Five (5) diets of breadfruit seed meal substituted for maize at different levels of inclusion (0%; 25%; 50%; 75% and 100%) were fed to the fingerlings at 5% body weight twice daily in hapa of 1m x 1m x 1m. The hapas wee submerged in a pond and each hapa stocked with 20 fingerlings of mean weight of 5.8~c0.00g. Evaluation of growth parameters nutrient utilization of the experimental diets showed that there was no significant difference (P〉0.05) in mean final weight (MFW); specific growth rate (SGR); feed conversion rate (FCR) protein efficiency ratio (PER) and apparent net protein utilization (ANPU) among the treatments. The results suggested a net advantage of replacing dietary maize with cooked breadfruit seed meal for Clarias gariepinus fingerlings at 50% and above levels of inclusion under the condition of the experiment.
    Description: Includes:- 4 tables.;10 refs.
    Keywords: Aquaculture ; Clarias gariepinus ; Nigeria ; Makurdi ; freshwater environment ; Fish culture ; Feeding experiments ; Growth rate ; Diets
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    Format: 292 - 296
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  • 3
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    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/23044 | 19325 | 2018-03-05 20:45:24 | 23044 | Fisheries Society of Nigeria
    Publication Date: 2021-07-12
    Description: The physical and chemical characteristics of freshwater bodies Ikot Ebak and Abeneyentem streams in Essien Udim Local Government Area, Akwa Ibom State, Nigeria were studied from (July December 1996). The mean values obtained in the two water bodies were pH (6.8~c0.12, 6.8~c0.09, respectively). Conductivity (4.9~c2.26, 5.0~c2.09 iScm-1), total dissolved solid (16~c7.58, 37~c26.9 mg/l), TSS (46~c26.0, 53~c53.1)g/l), alkalinity (17.5~c7.27, 10.7~c8S MgCaCo3/1), DO (6.98~C1.46, 8.3~C29.0mg/1), BOD (2.65~c2.44, 3.15~c2.79mg/1), Salinity (0.41~c0.12, 0.31~c0.04%o') total hardness (0.64~c0.21, 0.84~c0.42mg/l, N03-N (0.31~cO.26, 0.35~c0.29mg/l), and PD4-P (0.022~c0.0199 0.023~c.022mg/1), respectively. There were significant difference in the means of the parameters in the two water bodies except TDS, Alkalinity and Hardness. The water bodies were found to be slightly acidic with low conductivity. The properties in the water bodies were in conformity with international standards for both drinking and aquatic life.
    Description: includes:- 2 tables.;6 refs.
    Keywords: Chemistry ; Limnology ; Nigeria ; Ikot Ebak ; Nigeria ; Abeneyentem ; freshwater environment ; Physicochemical properties ; Alkalinity ; Salinity ; Dissolved oxygen
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    Format: 310 - 312
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  • 4
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    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/23037 | 19325 | 2018-03-05 09:18:00 | 23037 | Fisheries Society of Nigeria
    Publication Date: 2021-07-12
    Description: An experimental growth trial in floating net-hapas at three stocking densities in concrete pond was carried out. 4.68 5.25g mean individual weight fish were stocked at 25, 50 and 100 per m3. A 40% protein balanced diet was used as feed. The results of the study showed no statistical significant difference in growth among the three treatments. Food conversion ratios ranged in 1.60 to 1.82, and specific growth rates were between 3.80 and 4.16%/day. The result suggests that culture of C. gariepinus at a density of 50/m3 and production of 4.15kg/m3 in 84 days with production of 8.30kg/m3 in a growing season of 180 days is possible using the net-hapa systems enclosed in a concrete pond.
    Description: includes:- 2 tables.;8 refs.
    Keywords: Aquaculture ; Clarias gariepinus ; Nigeria ; Alau L. ; freshwater environment ; Fish culture ; Stocking density ; Growth rate ; Floating cages
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    Format: 276 - 278
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  • 5
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    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/23039 | 19325 | 2018-03-05 20:35:11 | 23039 | Fisheries Society of Nigeria
    Publication Date: 2021-07-12
    Description: A feeding experiment was conducted to quantify the minimum dietary vitamin C requirement of Heterobranchus longifilis fingerlings and the minimal dietary inclusion levels that will meet these requirements after degradation from feed processing and storage. Fish were fed a basal diet with 42.5% crude protein for a conditioning period of 2 weeks. Following conditioning, fingerlings with initial mean weight, 2.3~c0.3 g were stocked as groups of 20 fingerlings into 30 litre tanks in a mini flowthrough experimental system and fed the basal diet and experimental diets supplemented with 0, 50, 100, 150, 200, or 250 mg of L-ascorbic acid kg-1 diet obtained from TUYIL PHARM. INDUSTRIES, lIorin, included into the basal diet by replacing part of the silica component and fed to triplicate groups for 20 weeks. Fish fed the control (0 mg vitamin C kg-1) diet exhibited deficiency signs including lordosis, caudal fin deformity, skin erosion and significantly suppressed weight gain and higher condition factor. Protein efficiency ratio and specific growth rate were significantly improved with increasing levels of vitamin C up to 200mg kg-1 diet. Tissue (liver, kidney, gills and muscle) ascorbate concentration generally reflected dietary inclusion levels with the signiticant lowest level occurring in the control groups. Vitamin C analysis after feed processing revealed 18 - 21% loss. The least mean squares error regression analysis of weight gain data on inclusion level of vitamin C revealed that the minimum dietary requirement of H. longifilis is 82.2~c0.2 mg vitamin C kg-1 diet which corresponds to 100 mg of vitamin C kg-1 diet based on data from this study.
    Description: Includes:- 4 tables.;1 fig.;6 plates.;32 refs.
    Keywords: Aquaculture ; Heterobranchus longifilis ; Nigeria ; New Bussa ; freshwater environment ; Fish culture ; Feeding experiments ; Vitamin C ; Growth rate
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    Format: 283 - 291
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  • 6
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    Fisheries Society of Nigeria | Kaduna (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23289 | 19325 | 2018-03-30 14:45:43 | 23289 | Fisheries Society of Nigeria
    Publication Date: 2021-07-13
    Description: The growth, mortality and recruitment pattern of Tympanotonus fuscatus var fuscatus were investigated using shell length (SL) - frequency data obtained from the mangrove swamps of the Bonny River, population. Computer based software package FiSAT (FAO - ICLARM Fish Stock Assessment tool) were used for the analysis. Sampling was done between January to December, 2004. Results obtained showed relatively high growth, low mortality and recruitment pattern with two peaks annually.
    Description: Includes:- 2 tables.;1 fig.;11 refs.
    Keywords: Ecology ; Fisheries ; Tympanotonus fuscatus var fuscatus ; Nigeria ; Bonny Estuary ; freshwater environment ; Population dynamics ; Growth rate ; Mortality ; Recruitment
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    Format: 46-49
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  • 7
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23440 | 19325 | 2018-05-02 08:25:12 | 23440 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: The physical and chemical parameters of ABU Dam and Zaria Dam were carried out between September and October 2009. The results obtained in the two water bodies were temperature 27.7 0C, pH (7.5 and 7.3), dissolved oxygen (5.8 mg/l and 5.0 mg/l), biochemical oxygen demand (1.74 mg/l and 2. 16 mg/l), alkalinity (58 mg CaC03/l and 49 mgCaCO3/l) P04-P (2.47 mg/l and 1.59 mg/l) NO3-N (3.67 mg/l and 3.47 mg/l), conductivity (54.70 ~ks-1 and 42.48 ~ks-1), total hydrocarbon (TH) (47.66 mg/l) and 48.00 mg/l) and total dissolved solids (32.68 mg/l and 25.35 mg/l) respectively. There was no significant difference in the mean values of the parameters (P〉0.05) except conductivity and total dissolved solids. The water bodies were found to be neutral with high conductivity. All the properties in the water bodies were in conformity with international standards both for drinking and aquatic life.
    Description: Includes:- 2 tables.;7 refs.
    Keywords: Chemistry ; Limnology ; Pollution ; Nigeria ; Zaria Dam ; Nigeria ; ABU Dam ; freshwater environment ; Physicochemical properties ; Pollution
    Repository Name: AquaDocs
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    Format: 144-146
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  • 8
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23442 | 19325 | 2018-05-02 08:28:15 | 23442 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: In recent times there has been an upsurge in the culture of Tilapia in Nigeria resulting in increased demand for the fingerlings which is hardly satisfied. This is due to increasing demand for table size tilapia as food fish and under-sized tilapia in the fish meal and fish canning industries in Nigeria. Collection of Tilapia guineensis fingerlings from the wild, to augment hatchery production, has been the practice and this is subject to environmental fluctuations. Multivariate regression and correlation analyses of accumulated data were used to investigate the effects of changes in water quality parameters on abundance of fingerlings of Tilapia guineensis in a brackishwater habitat in Lagos. Dissolved oxygen (DO), salinity and secchi transparency were found to be the most dominant factors affecting the abundance of Tilapia guineensis fingerlings in the Lagos lagoon. Peak period of abundance was closely associated with period of low salinity (0.50%o to 5.60%o), which coincided with the period of low transparency and low DO in the rainy season. The correlation analyses of Tilapia guineensis fingerlings with the water quality parameters yielded the following correlation coefficients (r)- 0.598; (salinity); -0.644 (transparency); -0.710 (DO); -0.566; (temperature) and 0.129 (pH). The abundance of Tilapia guineensis fingerlings in the Lagoon was ultimately defined by a suitable regression equation. This result is expected to optimize the collection of fingerlings of Tilapia guineensis from the wild and boost food fish security in Nigeria and elsewhere.
    Description: Includes:- 1 table.;1 fig.;( refs.
    Keywords: Chemistry ; Fisheries ; Tilapia guineensis ; Nigeria ; Port Harcourt ; brackishwater environment ; Water quality ; Fingerlings ; Chemical properties ; Physicochemical properties
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    Format: 153-157
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  • 9
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23445 | 19325 | 2018-05-02 08:32:33 | 23445 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: Spatial and temporal variations of physico-chemical variables of Onu-Iyi ?Ukwu stream were studied for 12 months from March 2005 to February 2006. Three sampling stations were established along the main stream channel from source to mouth. Spatial variation in physico-chemical parameters indicated that total alkalinity, total hardness, conductivity, and nitrate-nitrogen (NO3) recorded their highest values at the upper reaches (with values 14.0mg/l, 88.09mg/l, 17.00~kscmiscm, and 0.60mg/l respectively). Dissolved Oxygen (DO) and pH had their maximum values of 8.20mg/l and 6.94 at the middle reaches. Turbidity, biochemical oxygen demand (BOD), temperature and phosphate-phosphorus (PO4) increased steadily from source to mouth. The observed seasonal variation indicated that wet season values were higher for all the parameters except temperature, turbidity, phosphate-phosphorus (PO4) and total alkalinity although the values were not statistically significant at p〉0.05. The correlation coefficient (r) showed no significant relationships p〈0.05 between physico-chemical parameters except DO and BOD with correlation values of (0.75 and -0.54) respectively.
    Description: includes:- 2 tables.;1 fig.;17 refs.
    Keywords: Chemistry ; Limnology ; Nigeria ; Onu-Iyi-Uku Stream ; freshwater environment ; Physicochemical properties ; Phosphates ; Phosphorus ; Turbidity
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    Format: 174-180
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  • 10
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23449 | 19325 | 2018-05-02 08:39:20 | 23449 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: The physico-chemical parameters of Bosso Dam were analyzed weekly for a period of six (6) weeks from 29th October, 2009. In all, six (6) stations were identified within the dam. The physico-chemical parameters assessed were: temperature, dissolved oxygen, pH, alkalinity, hardness, conductivity and transparency. The results obtained from the analysis revealed slight variations in most parameters. There was no significant difference p〉0.05 in pH regardless of stations and weeks. But significant difference p〉0.05 were observed in dissolved oxygen, nitrate, temperature, conductivity, hardness, alkalinity, biological oxygen demand, transparency, in respect regard to stations. These variations could be due to influx of organic waste from surface run offs and inorganic waste deposited by man. The physico-chemical parameters observed, indicated that most of them fall with the recommended range or standard by the Federal Ministry of Environment
    Description: Includes:- 2 tables.;10 figs.;18 refs.
    Keywords: Chemistry ; Limnology ; Nigeria ; Bosso dam ; freshwater environment ; Physicochemical properties ; Chemical properties ; Physical properties ; Water properties
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  • 11
    Publication Date: 2021-07-14
    Description: An experiment was carried out to find out the comparative effect of imported fish meal, blood meal and local fish waste based diets on the growth and survival of juvenile tilapia. (O. niloticus) in concrete tank. Four diets consisting of N.I.O.M.R. pelleted feed containing 40% CP, with imported fish meal, as the control and three others formulated with fresh, boiled cattle blood and local fish waste meal at 30% CP, were fed to juvenile tilapia with average initial weight of 55.24g in four treatments and four replicates in a completely randomized design. Result indicated final body weights of 100.83, 96.54, 98.4 and 86.82g and average body length of 18.47, 18.16, 18.4 and 18.14cm, for treatments 1 (control), 2 (fresh blood based diet), 3 (boiled blood based diet) and 4 (local fish waste meal based diet) respectively, with no significant difference between the treatments (P〉0.05). The same was also true for average daily weight gain of 0.41, 0.36, 0.31 and 0.28g. However, treatment 1 and 2 had better relative weight gain 93.69 and 80.21%, than 3 and 4 at 62.37 and 64.85% respectively, (P〈0.05). The survival was 100% in all treatments. Treatment 2 was more cost effective at N539.06/Kg fish, followed by 1 with N667.52. Treatments 3 and 4 had the highest at N698.20 and N718.60 per kg fish. The trial showed that tilapia feed processed with fresh cattle blood performed as well as imported fish meal, boiled blood and local fish waste and in addition was more cost effective.
    Description: Includes:- 6 tables.;11 refs.
    Keywords: Aquaculture ; Oreochromis niloticus ; Nigeria ; Port Harcourt ; Feed evaluation ; freshwater environment ; Feeding experiments ; Diets ; Nutritional requirements ; Survival ; Growth rate
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  • 12
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23503 | 19325 | 2018-05-07 12:27:24 | 23503 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: Growth (Percentage weight gain, Specific growth rate , total body length), survival rate and condition factor of Heteroclarias fry fed shell free Artemia, cultured Moina micrura and mixture of both as starter feed were investigated. 30 individual fry were placed in a 4-litre plastic bowl in three treatments of 3 replicates for 25 days in Fish Hatchery. Individual water quality parameters (water pH, temperature, Dissolved oxygen, total Alkalinity and carbon dioxide) monitored for each treatment were not significantly different (p〉0.05) from each Heteroclarias fry fed live M. micrura had the highest percentage weight gain (496.03%), Specific growth rate (3.09), percentage survival rate (88.83%) and condition factor (39.75) but these results were not significant different (P〉0.05) from those of shell free Artemia except those of condition factor. Shell free Artemia and Live M. micrura combination was observed to have the lowest fry Percentage weight gain (428.30%),. specific growth rate(2.54), % survival rate (85.50), condition factor(24.39) and total body length(1.52cm). The highest total body length was observed in shell free Artemia although not significantly different (p〉0.05) from others. The implication of using cultured live M. micrura instead of shell free Artemia as starter diet for Heteroclarias hatchlings at the critical stage of development are discussed
    Description: Includes:- 6 figs.;16 refs.
    Keywords: Aquaculture ; Heteroclarias ; Moina micrura ; Nigeria ; Keffi ; freshwater environment ; Growth rate ; Survival ; Condition factor ; Feeding experiments ; Fish culture
    Repository Name: AquaDocs
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    Format: 519-525
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  • 13
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23505 | 19325 | 2018-05-07 12:31:00 | 23505 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: Feeding trial was conducted in static water to assess the growth of Clarias gariepinus fingerlings fed different inclusion levels of Mucuna seed meal (MSM). Raw MSM was used at 10%, 20% and 30% inclusion levels and the performance of fish fed these diets was compared with the fish fed soybean-based diet which contained 40%protein. All diets were prepared to be isonitrogenous and isocaloric. A four by six factorial experiment with three replicates using ten fish each of average initial weight of 6.6g was carried out. Daily fish ration of five percent body weight was administered two times for twelve weeks. The specific growth rate (SGR) in diet 1 (control) was significantly (p〈0.05) higher than the other dietary groups and worsens as inclusion level increased similar trend was also observed in the food conversion ratio (FCR) and protein efficiency ratio (PER). The significantly lower growth performance of fish fed diets containing raw MSM might be due to the presence of anti-nutritional factors present raw MSM. The possibility of improving this trend through processing should be investigated.
    Description: Includes:- 3 tables.;14 refs.
    Keywords: Aquaculture ; Clarias gariepinus ; Nigeria ; Osogbo ; freshwater environment ; Feeding experiments ; Fish culture ; Diets ; Growth rate
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    Format: 531-535
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  • 14
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23510 | 19325 | 2018-05-05 13:09:20 | 23510 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: Clarias gariepinus (0.73 ~c 0.01g) and Heterobranchus longifilis fingerlings (0.67 ~c 0.01g) were fed five isonitrogenous diets of about 40% crude protein, with varying levels (0-100%) of palm grub meal for 12 weeks. At the end of the study, C. gariepinus and H. longifilis fingerlings fed 25% palm grub inclusion diet had the highest weight gain (5.30g and 4.05g respectively), relative (726.0% and 595.6%) and specific (1.09% and 1.00%) growth rates while those fed 100% palm grub inclusion diet showed least growth; weight gain (2.68g and 2.15g), relative (367.1% and 316.2%) and specific (0.80% and 0.45%) growth rates respectively. Food conversion and protein efficiency were also best in fingerlings fed 25% palm grub meal diet (0.70 and 1.35 for C. gariepinus; 0.75 and 1.35 for H. longifilis respectively) with decreasing efficiency as palm grub inclusion level increased in the diets. The differences in the growth and nutrient utilization of the fingerlings on the various diets were generally insignificant (p〉0.05) above 25% inclusion level of palm grub. The study showed that palm grub can be used to completely replace fish meal in mudcatfish diets. However, for optimal growth and nutrient utilization, 25% level of replacement of fish meal with palm grub meal is most adequate in C. gariepinus and H. longifilis fingerlings diets.
    Description: Includes:- 7 tables.;2 figs.;12 refs.
    Keywords: Aquaculture ; Clarias gariepinus ; Heterobranchus longifilis ; Oryctes rhinoceros ; Nigeria ; Ibadan ; freshwater environment ; Feeding experiments ; Growth rate ; Fish culture ; Diets
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  • 15
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23536 | 19325 | 2018-05-10 10:07:34 | 23536 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: The paper defined quarantine as the totality of measures taken by every country to prevent the entry of foreign exotic pest, pathogens and diseases of plant, animals and aquatic resources through international boundries. Also discussed is the international regulatory framework on quality control and quarantine of agricultural products. The advantages and socioeconomics impact of quarantine are discussed. The paper further examined the best practice procedure in quarantine service delivery in the aquatic resources and products right from production, processing, marketing and condition for exporting of aquatic (Live fish) from Nigeria, In conclusion the paper enumerated the challenges in meeting best practice procedures in quarantine service delivery
    Description: Paper delivered at the Agricultural Quarantine Services (NAQS) Paramilitary Training for Officers and Men, Jaji, Kaduna, 15-29 ?, 2009 Presented at FISON EKO 2010: Other materials. Pagination on document pp. 1-18
    Keywords: Fisheries ; Health ; Nigeria ; Quarantine ; freshwater environment ; marine environment ; Quarantine regulations ; Legislation ; Safety regulations
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  • 16
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    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/22999 | 19325 | 2018-03-05 09:30:30 | 22999 | Fisheries Society of Nigeria
    Publication Date: 2021-07-12
    Description: Water samples were collected from River Gurara around the Gurara Falls and Izom settlement once every month for a period of twelve (12) months (June 2004 May 2005). Microbial studies were carried out on the water samples collected. There were marked variations between different samples, stations and seasons. The microbial studies showed the presence of enteric gram negative, gram positive and pyogeric groups of bacteria. Some species of indicator organisms were recorded. The results obtained showed that the activities of Izom populace has some impact on the water quality and public health status of River Gurara
    Description: Includes:- 2 tables.;12 refs.
    Keywords: Biology ; Conservation ; Health ; Nigeria ; Gurara R. ; freshwater environment ; Public health ; Microbiological analysis ; Bacteria ; Fungi
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  • 17
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    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/22998 | 19325 | 2018-03-05 20:41:44 | 22998 | Fisheries Society of Nigeria
    Publication Date: 2021-07-12
    Description: The effect of exposing juveniles of Heterobranchus bidorsalis (Geoffroy St. Hilaire, 809) (mean weight: 15.02~c:0.14g) to different concentrations of Bonny-light crude oil (BLCO) on alanine kinase and alanine transaminase activities were studied. The exposure of the fish to 1.00, 2.00, 4.00, 8.001L-1 BLCO and a control (0.00m1 L-1) within 4 days toxicity and 42 days recovery periods indicated that the significant increases (P〈0.05; P〈0.01) in the serum alanine transaminase (HCAT) activities were dependent on the BLCO concentrations. The reduced SAK and (HCAK) activities noticed within the first 14 days recovery period implied that the removal of the oil pollutant probably lowered the pressure on the SAK and HCAK to participate in the metabolism of ingested carbohydrate. The significant increases in the serum alanine transminase (SAT) and the hepatic cytosolic alanine transminase (HCAT) activities in the fish corresponded with the trend shown by the SAK and HCAK activities. Generally, the increased activities of SAK, HCAK, SAT and HCAT in H. bodorsalis juveniles in this study might be due to a shift in the carbohydrate metabolism of the fish caused probably by the crude oil exposure.
    Description: Includes:- 3 tables.;31 refs.
    Keywords: Fisheries ; Health ; Pollution ; Heterobranchus bidorsalis ; Nigeria ; freshwater environment ; Crude oil ; Toxicity ; Fish ; Serum ; Serological studies ; Alanine ; Cytotoxicity
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  • 18
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    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/23017 | 19325 | 2018-03-05 09:26:57 | 23017 | Fisheries Society of Nigeria
    Publication Date: 2021-07-12
    Description: The physico-chemical and biological characteristics and nutrient concentration of Kigera Fish Farm ponds were monitored for two months to assess the water quality. The parameters measured were dissolved oxygen, temperature, hydrogen ion concentration, Secchi-disc transparency and zooplankton composition. Some fish species were identified in the course of study. Temperature ranged from 26 -30degreesC; dissolved oxygen ranged from 3mg/l-6.6mg/l, pH ranged 7.0 -7.2; while Secchi-disc transparency ranged from 0.19 - 0.25m. The three ponds were quite similar in these parameters. All the parameters that were investigated in this study are within the tolerable level for warm water fishes. Five different zooplankton species were identified at the Kigera Fish Farm, and were grouped according to their major categories namely: Copepods, Cyclopoids and Copepodite), Cladoceran (〈i〉Moina〈/i〉), and Rotifera (〈i〉Asplanchina〈/i〉). 〈i〉Branchionus〈/i〉 species in the Rotifers group dominated the zooplankton species in all the three ponds.
    Description: includes:- 5 tables.;7 refs.
    Keywords: Aquaculture ; Chemistry ; Nigeria ; Kigaria Dam ; freshwater environment ; Water quality ; Physicochemical properties ; Zooplankton
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  • 19
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    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/23058 | 19325 | 2018-03-06 15:37:11 | 23058 | Fisheries Society of Nigeria
    Publication Date: 2021-07-12
    Description: A study was conducted to determine the concentrations of nine heavy Metals (Cadmium, lead.Copper, Chromium, Iron, Zinc, Selenium, Nickel and Aluminum) in gills, muscles and skin of Clarias gariepinus within three different locations (Kuatansule, Wadata and UAM fish) with the use of standard flame Atomic Absorption Spectrophotometry Techniques. Iron was found in high concentration in all the sites with the gills having the highest concentration while lead. Cadmium, Selenium, Nickel and Aluminum were not detectable. Significant differences in metal concentrations were observed between locations with UAM fish farm having the highest metal concentration. It is concluded that concentration, of heavy metals found in selected organs of Clarias gariepinus were within tolerable limits as recommended by FAO.
    Description: Includes:- 1 fig.;13 refs.
    Keywords: Fisheries ; Health ; Clarias gariepinus ; Nigeria ; Makurdi ; freshwater environment ; Metals ; Heavy metals ; Fish ; Toxicity ; Health and safety
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  • 20
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    Fisheries Society of Nigeria | Kaduna (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23290 | 19325 | 2018-03-30 14:47:44 | 23290 | Fisheries Society of Nigeria
    Publication Date: 2021-07-13
    Description: The knowledge of sources and routes of fish contamination is a very important aspect in maintaining the quality of safety of fish. This is paramount because the sources constitute the acess through which most unwanted microorganisms may be transmitted onto fish and fishery products. Unwanted microorganisms may be found in the final product through raw material, personal handling or mobile equipment such as forklifts, through leakage and openings in building, or through pests. Some pathogens may even become established in the processing equipment and rough contact surfaces such as fish retail tables and from niches where they can survive for long periods of time. Many of these microorganisms occur naturally in aquatic and general environments, and may be transmitted onto fish before capture, during and after processing. Also, contamination via air can occur through dust particles or via aerosols. Water is also a vehicle for transmission of many agents of diseases. Thus, the quality of the raw material, personnel hygiene, equipment used for processing, the quality of the water used and pests are key issues in this context. As for quality assurance, methods such as the Good Manufacturing Practice (GMP), Good Hygiene Practice (GHP) and Hazard Analysis Critical Control Point (HACCP) are recommended by the Codex Alimentarius Commission for use by any food processing establishment to ensure safe, wholesome and nutritious food for human consumption
    Description: 27 refs.
    Keywords: Fisheries ; Health ; Nigeria ; freshwater environment ; Health and safety ; Safety regulations ; Sample contamination ; Microorganisms ; Hygiene ; Fishery products
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  • 21
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    Fisheries Society of Nigeria | Zaria (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23305 | 19325 | 2018-03-30 15:13:13 | 23305 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: Factors which threaten sustainable commercial fisheries are considered in this paper. Oil and grease, suspended solids, overfishing impact on fishes and fisheries. Whereas overfishing declines adult fish values; the duo of oil and suspended solids clog and disable gills of affected fishes and deplete insolation. And barnacles foul boats.
    Description: Includes:- 1 table.;13 refs.
    Keywords: Fisheries ; Health ; ASE ; Nigeria Coast ; freshwater environment ; Pollution ; Pollution effects ; Oil pollution
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  • 22
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    Fisheries Society of Nigeria | Zaria (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23301 | 19325 | 2018-03-30 15:07:39 | 23301 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: Screened retail table was designed to improve the hygiene of fish sold in our local markets. Investigation was carried out on the microbiological population on Tilapia fish. Overall value obtained from plate counts show that fish were more infested outside the table. The sensory values are 4, 13, and 6 for on-sport open table and screened respectively, also microbial load range between 7x10-5 to 88 x 10-5 cfu/g for open table where 3x 10-10 - 33 x 10-10 for screened table. This shows that fresh fish on open retail table in our markets were prone to deterioration.
    Description: Includes:- 3 tables.;1 refs.
    Keywords: Fisheries ; Health ; Nigeria ; Fresh fish marketing ; freshwater environment ; Deterioration ; Fish spoilage ; Quality control ; Processing fishery products ; Marketing ; Hygiene
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  • 23
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    Fisheries Society of Nigeria | Kaduna (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23319 | 19325 | 2018-03-30 15:34:16 | 23319 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: The seasonal variations in the physicochemical parameters were studied from January, 2007 to December 2007, in Kontagora Reservoir, Niger State, Nigeria. The physico- chemical parameters were determined bi-monthly , using the following methods , temperature using mercury thermometer in degree centigrade, transparency using Secchi-disc , Pye Unicam model 292 meter used for pH and electrical conductivity. Dissolved oxygen by modified Winklerazide method, water hardness and Phosphate- phosphorus by method of Lind (1979), total alkalinity by standard method described by Boyd(l979) , Nitrate- Nitrogen by Phenoldisulphonic acid method. The rainy season mean values for water temperature, depth, pH, Nitrate-Nitrogen, were significantly (P〈0.05) higher than those for the dry season. However, for transparency, conductivity, dissolved oxygen, hardness, alkalinity, phosphate-phosphorus and total dissolved solid, the dry season mean values were higher than the rainy season mean value. As in most other Africa inland water bodies, there was seasonality in the physicochemical parameters variables. The torrential rains of the dam environment, the characteristics trade winds of the dry season, effect of deforestation, fertilizer application, herbicides, insecticide and other chemical factors might have contributed to the fluctuations of some of the physicochemical parameters detennined in the Reservoir.
    Description: Includes:- 2 tables.;1 fig.;39 refs.
    Keywords: Chemistry ; Nigeria ; Kontagora L. ; freshwater environment ; Physicochemical properties ; Seasonal variations
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  • 24
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    Fisheries Society of Nigeria | Kaduna (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23309 | 19325 | 2018-03-30 15:18:56 | 23309 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: Selective breeding studies were carried out in four genetic mating combinations of Clarias gariepinus with the aim of improving its growth performance. F2 intraspecific and backcross were produced using the best male and female of the best genetic mating combination in the F generation in crosses of three wild strains of Clara gariepinus. The highest percentage hatchability (75%) was recorded in female Kainji parental and male Kainji F1. and the least (53.67%) in female and Male Kainji Fl. The cross involving female Kainji F1. and Male Kainji Parental had the best survival (49%) indoor and also best (38.67%) outdoor, while the least (37.67%) was recorded in female Kainji parental and Male Kainji F1 and also gave the least (32.67%) outdoor. The female Kainji F1, and male Kainji parental gave the best growth performance (1.61 g) at 19 days indoor rearing, while female and male Kainji parental gave the least (1.50g). At the end of seven months rearing outdoor, the female Kainji parental and male Kainji F1. gave the best growth performance of(222.49g) and the least (180.66) was recorded in female Kainji F1 and male Kainji parental.
    Description: Includes:- 3 tables.;2 figs.;14 refs.
    Keywords: Aquaculture ; Fisheries ; Clarias gariepinus ; Nigeria ; Fish genetics ; fish breeding ; freshwater environment ; Genetics ; Breeding ; Fish culture ; Growth rate ; Hybrid culture ; Hybrids
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  • 25
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    Fisheries Society of Nigeria | Kaduna (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23316 | 19325 | 2018-03-30 15:28:47 | 23316 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: The initial mean wet weight of the test fish were 7.64:~c 1.3 for the control and 6.33~c 0.9, 6.88~c 0.9 and 6.2~c 0.7 for the fish exposed to 1.02, 1.40 and 2.0mg/l of paraquat in water respectively. Growth was estimated from the sum of the individual wet weights of the fish at 2, 4, 6 and 8 weeks of exposure to the toxicant and expressed as percent Cumulative wet weight gain. The results showed that the cumulative percent wet weight gain in the control group increased from 10.34% at 1 week to 36.13% at 8 weeks. The growth of fish that were exposed to 1.02, 1.04 and 2.00mg/l increased from 3%, 0.44% and 1.55% at 1 week to 30.81 %, 9.59% and 19.81 % at week 8 respectively. A statistically significant difference in growth rate of the treated and control was observed (p〈0.05).
    Description: Includes:- 4 tables.;5 refs.
    Keywords: Aquaculture ; Pollution ; Oreochromis niloticus ; Nigeria ; Paraquat ; freshwater environment ; Fish culture ; Growth rate ; Growth ; Sublethal effects ; Toxicity
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  • 26
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23496 | 19325 | 2018-05-07 12:15:56 | 23496 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: The study accessed the quality changes of Alestes nurse displayed at 31-33oC average daily temperature on different platforms, the traditional retail table used by fish processors and the NIFFR improved retail table. The fishes were displayed on the tables for 9 hours and quality attributes were monitored hourly by trained panelists. For A. nurse, the gills and intestine recorded faster deterioration starting from the fourth and fifth hours for samples in the traditional table while those in improved table were prolonged by one hour. Scores for skin brightness and texture did not indicate quality deterioration throughout the display period. However, at the end of the storage time, samples in screened table recorded 1.5 x 104 cfu/g while samples in unscreened table recorded 3.7 x 107 cfu/g. The study shows the effectiveness of the improved table over the traditional table in enhancing the keeping quality, minimizing fish contamination and improving the general hygiene of fresh fish.
    Description: Includes:- 3 tables.;2 figs.;7 refs.
    Keywords: Fisheries ; Health ; Alestes nurse ; Nigeria ; New Bussa ; freshwater environment ; Fish handling ; Hygiene ; Public health
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  • 27
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23460 | 19325 | 2018-05-05 12:31:34 | 23460 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: The morphometric characters of Cynothrissa mento from three major Lagoons (Ologe, Badagry and Epe) in Lagos, Nigeria were compared to assess the possibility of this fish species from the three Lagoons belonging to the same sub-population. The length-weight relationships (LWR), and condition factors (CF) of the fish were also described as well as the physico-chemical parameters of the three water bodies. The study was conducted between May, 2009 and April, 2010 and monthly sampling of fish and water was done in each sampling site. Seven7 physico-chemical parameters were assessed and these are; temperature, pH, salinity, turbidity, dissolved oxygen, total alkalinity and total hardness. A total of 294 specimens (Ologe 60, Badagry 174 and Epe 60) of C. mento were collected from the landings of the local fisher folks from the sampling sites. Seven morphometric characters; total length (TL), standard length (SL), body depth (BD), head length (HL), head depth (HD), eye diameter (ED) and interorbital width (IW) were measured. There was no significant difference (p 〉 0.05) in all the physico-chemical parameters measured among the sampling sites except pH. Coefficient of difference revealed that the C. mento from the three lagoons are uniform in all the morphometric parameters examined, which means that the specimens from the three sampling sites do not belong to different sub-populations. The growth coefficient/slope (b) values obtained for the fish species from the sampling sites ranged from 2.27 - 2.53, and differed significantly (p 〈 0.05) from 3, which indicates that most of the fish species have negative algometric growth.
    Description: Includes:- 4 tables.;1 fig.;24 refs.
    Keywords: Ecology ; Chemistry ; Cynothrissa mento ; Nigeria ; Ologe Lagoon ; Nigeria ; Badagry Lagoon ; Nigeria Epe Lagoon ; marine environment ; Population dynamics ; Morphometry ; Check lists ; Length-weight relationships ; Condition factor ; Physicochemical properties
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  • 28
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23466 | 19325 | 2018-05-05 12:42:05 | 23466 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: An experiment was conducted to determine the survival rate, fertilization rate, growth performance and feed utilization of the reciprocal hybrids of Clarias gariepinus and Heterobranchus bidorsalis. Two genetic crosses were made: C. gariepinus (male) x H. bidorsalis (female)(Clariabranchus) and H. bidorsalis male x C. gariepinusmale (Heteroclarias. The experiment was divided into two phases; artificial propagation of the fish species using synthetic hormone and rearing the fry for 14 days; and rearing the 14 days old fry for 35 days. In the first phase of the experiment, survival of frys were estimated in each experimental unit (genetic cross) while in the second phase, growth and nutrient utilization were investigated. The result revealed that the highest %fertilization, hatching rate and %survival occurred in H. bidorsalisfemale x C. gariepinus male (Heteroclarias) and the differences were significant (p 〈 0.05). Percentage weight gain and specific growth rate were significantly (p 〈 0.05) higher in Clariabranchus than Heteroclarias. Based on the result of this study, reciprocal hybrids of Clarias gariepinus and Heterobranchus, bidorsalis is recommended for commercial aquacultural practices.
    Description: Includes:- 3 tables.;13 refs.
    Keywords: Aquaculture ; Clarias gariepinus ; Heterobranchus bidorsalis ; Heteroclarias ; Nigeria ; Lagos ; freshwater environment ; Survival ; Growth rate ; Feed efficiency ; Genetics ; Fish culture
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  • 29
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    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23497 | 19325 | 2018-05-07 12:17:33 | 23497 | Fisheries Society of Nigeria
    Publication Date: 2021-07-14
    Description: The changes that occur on proximate composition of some common fish processing methods used in Nigeria were studied in order to determine the nutritional content of the processed products. Traditional (smoke drying and sun drying) and modern (electrical oven drying) methods of processing were used to process Pseudotholithus elongatus and the results were compared with the fresh sample to determine the changes that occur during processing. The results for the fresh sample of P. elongatus were 79.50%, 1.50%, 0.8% and 18.2% for moisture, ash, lipid and protein. For the processed products, the moisture content for smoke-dried, sun-dried, salt sun-dried and oven-dried fish were 27.00%, 21.83%, 19.50% and 20.17% . Oven dried had the highest protein content (69.87%) while salt sun-dried had the lowest (54.90%). Lipid content was highest in sun-dried (6.6%) and lowest in smoke-dried (4.6%). Correlation between smoke-dried and sun-dried were r2 = 0.99, smoke-dried and oven-dried were r2= 0.98 and smoke-dried and salt sun-dried were r2= 0.98. There was no correlation between the fresh and the processed P.elongatus. The present findings revealed that processing affect the nutritional composition of fish.
    Description: Includes:- 1 table.;22 refs.
    Keywords: Fisheries ; Health ; Pseudotolithus elongatus ; Nigeria Lagos ; Proximate composition ; freshwater environment ; Processing fishery products ; Moisture ; Proteins ; Chemical analysis ; Lipids
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  • 30
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    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/23020 | 19325 | 2018-03-05 20:30:27 | 23020 | Fisheries Society of Nigeria
    Publication Date: 2021-07-12
    Description: The growth response, nutrient utilization, cost benefits and haematological responses of two hundred and fifty (250) Heterobranchus longifilis fingerlings fed maggot meal based diets were evaluated for 70 days in mini flow through system. Twenty fingerlings were stocked in triplicate in fifteen mini flow through system of plastic tanks of fifty (50) litres capacity and coded MM1 - MM5 in relation to their diet name. Five isonitrogenous (40.0%) and caloric content (2017.S 2092.3kJ/100g) maggot meal based diets namely MM1 O%maggot meal, MM2 25% maggot meal, MM3 -50% maggot meal, MM4- 75% maggot meal and MM5- 100% maggot meal were used for the experiment. The higher the proportion of maggot in the meal, the higher the ether extract and crude fibre. No significant difference (p〉0.05) existed between ash content of the experimental diets. Diet MM2 had the best growth performance and highest MGR with a significant difference (p〈0.05) with other diets fed fish. No significant differences (p〉0.05) existed between the growth parameters for diets MM1 MM3 and MM4 A positive correlation (r = 1.0) existed (p〈0.05, 0.25) between the growth parameters for the different experimental diets. Highest correlation (r =0.9981) existed p〈0.05 between MGR within the treatments. Highest Haematocrit (23%) Haemoglobin content (7.68g/dl) and whole blood clotting time (46 see) were recorded from H. longifilis fed MM5. Without any reservation, inclusion of maggot based meal diet is recommended as feed in the diet of H. longifilis to 75% replacement of fish meal for growth and better healthy condition so as to ensure sustainable aquaculture in Nigeria.
    Description: Includes:- 3 tables.;1 fig.;26 refs.
    Keywords: Aquaculture ; Heterobranchus longifilis ; Nigeria ; Maggot meal ; freshwater environment ; Fish culture ; Food organisms ; Diets ; Feed efficiency ; Growth rate ; Haemoglobins
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  • 31
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    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/23059 | 19325 | 2018-03-06 15:38:43 | 23059 | Fisheries Society of Nigeria
    Publication Date: 2021-07-12
    Description: The proximate composition of the fresh water shrimp Atya gabonensis (Irvine), preserved by smoking, salting and sun - drying was determined and compared to the fresh shrimp. All the preservation methods significantly (p〈 0.05) increased the total dry matter (38.34 93%), protein content (17.31 48.9) and ash content (28.36 36.17%) over the fresh shrimp value. Moisture and lipid contents however, were reduced from the fresh shrimp's 61.66% and 25.29% to low value of 7.00% and 5.10% respectively. The preserved shrimp is, therefore, nutritionally superior to the fresh shrimp as preservation enhances its proximate composition. Of all the preservation methods used in this work, smoking is the best. It recorded the best preservation indices of lowest moisture content, higher dry matter, higher protein content and highest ash content.
    Description: Includes:- 1 table.;13 refs.
    Keywords: Fisheries ; Chemistry ; Atya gabonensis ; Nigeria ; Benue R. ; freshwater environment ; Lipids ; Organic compounds ; Proteins ; Ash content ; Cured products ; Fish ; Shrimp fisheries
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  • 32
    ISSN: 1432-2285
    Keywords: Dendrochronology ; Growth rate ; Pilgerodendron uviferum ; Chile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Increment borer samples taken at breast height in Pilgerodendron uviferum (Cupressaceae) trees growing in two Chilean forest stands near latitude 42° south were used to study growth rates in diameter, basal area, and height. Radial average growth is 0.51 mm/year in Santa Luciă 0.44 mm/year in the Piuchué stand; the correlation between diameter and age is 0.79 in Santa Lucía and 0.64 in Piuchué. Similar results were obtained in the basal area/age relationship. Both groups of trees have a low rate of growth compared to rates obtained in other studies. Maximum values for radial growth (culmination age) are reached at 110 years of age in Santa Lucia and 50 years in Piuchue. Growth in height, averaging 5.8 cm/year, appears to be similar in all trees analyzed; occasional differences can be attributed to understory position of some trees. Comparison of radial growth and germination of Pilgerodendron plants shows a synchronous relationship, suggesting an influence of climate on the pattern of forest regeneration.
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  • 33
    ISSN: 1432-2048
    Keywords: Chlorophyll fluorescence ; Growth rate ; Nitrogen and photosynthesis ; Photoacclimation ; Photoinhibition of photosynthesis ; Photosynthesis and N supply ; Quantum yield ; Ulva
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Clonal tissue of the marine chlorophyte macroalga,Ulva rotundata Blid., was transferred from 100 to 1700 μmol photons · m−2 · s−1 under limiting (1.5 μM NH 4 + maximum, N/P=2) and sufficient (15 μM NH 4 + maximum, N/P=20) nitrogen supply at 18° C and 11 h light-13 h darkness daily. Photoinhibition was assayed by light-response curves (photosynthetic O2 exchange), and chlorophyll fluorescence at 77 K and room temperature. Daily surface-area growth rate (μSA) in N-sufficient plants increased sixfold over 3 d and was sustained at that level. During this period, respiration (R d) doubled and light-saturated net photosynthesis capacity (P m) increased by nearly 50%, indicating acclimation to high light. Quantum yield (ϕ) decreased by 25% on the first day, but recovered completely within one week. The ratio of variable to maximum fluorescence (F v/F m) also decreased markedly on the first day, because of an increase in initial fluorescence (F o) and a decrease inF m, and partially recovered over several days. Under the added stress ofN deficiency, μSA accelerated fivefold over 4 d, despite chronic photoinhibition, then declined along with tissue-N. Respiration doubled, butP m decreased by 50% over one week, indicating inability to acclimate to high light. Bothϕ andF v/F m decreased markedly on the first day and did not significantly recover. Changes inF o,F m and xanthophyll-cycle components indicate concurrent photodamage to photosystem II (PSII) and photoprotection by thermal deexcitation in the antenna pigments. Increasing μSA coincided with photoinhibition of PSII. Insufficient diel-carbon balance because of elevatedR d and decliningP m and tissue-N, rather than photochemical damage per se, was the apparent proximate cause of decelerating growth rate and subsequent tissue degeneration under N deficiency inU. rotundata.
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  • 34
    ISSN: 1432-2048
    Keywords: Chlorophyll fluorescence ; Growth rate ; Nitrogen and photosynthesis ; Photoacclimation ; Photoinhibition of photosynthesis ; Photosynthesis and N supply ; Quantum yield ; Ulva
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Clonal tissue of the marine chlorophyte macroalga, Ulva rotundata Blid., was transferred from 100 to 1700 μmol photons · m−2 · s−1 under limiting (1.5 μM NH 4 + maximum, N/P=2) and sufficient (15 μM NH 4 + maximum, N/P=20) nitrogen supply at 18° C and 11 h light-13 h darkness daily. Photoinhibition was assayed by light-response curves (photosynthetic O2 exchange), and chlorophyll fluorescence at 77 K and room temperature. Daily surface-area growth rate (μSA) in N-sufficient plants increased sixfold over 3 d and was sustained at that level. During this period, respiration (R d) doubled and light-saturated net photosynthesis capacity (P m) increased by nearly 50%, indicating acclimation to high light. Quantum yield (ϕ) decreased by 25% on the first day, but recovered completely within one week. The ratio of variable to maximum fluorescence (F v/F m) also decreased markedly on the first day, because of an increase in initial fluorescence (F o) and a decrease in F m, and partially recovered over several days. Under the added stress of N deficiency, μSA accelerated fivefold over 4 d, despite chronic photoinhibition, then declined along with tissue-N. Respiration doubled, but P m decreased by 50% over one week, indicating inability to acclimate to high light. Both ϕ and F v/F m decreased markedly on the first day and did not significantly recover. Changes in F o, F m and xanthophyll-cycle components indicate concurrent photodamage to photosystem II (PSII) and photoprotection by thermal deexcitation in the antenna pigments. Increasing μSA coincided with photoinhibition of PSII. Insufficient diel-carbon balance because of elevated R d and declining P m and tissue-N, rather than photochemical damage per se, was the apparent proximate cause of decelerating growth rate and subsequent tissue degeneration under N deficiency in U. rotundata.
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  • 35
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 90 (1995), S. 733-739 
    ISSN: 1432-2242
    Keywords: Oncorhynchus kisutch ; Nested design ; Heritability ; Freshwater ; Growth rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Genetic parameters of size through sexual maturity have been relatively unexplored for Pacific salmon. In this study, individually tagged coho salmon were raised in freshwater, and the heritabilities of size and growth rate were estimated at several intervals between 13 and 24 months of age (spawning). Heritability estimates for size were moderate to high from 13 to 19 months of age, ranging from 0.36 to 0.50, and lower from 21 months to spawning at 24 months, ranging from 0.17 to 0.32. Heritabilities of specific growth rates estimated over 3-month intervals were moderate from 16 to 21 months of age, ranging from 0.21 to 0.34. Genetic and phenotypic correlations between sizes measured at different ages were moderate to high, ranging from about 0.7 to 1.0. Correlations between growth rate and size indicated that the larger fish were the fastest growing between 16 and 19 months of age and were slower growing between 19 and 21 months of age.
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  • 36
    ISSN: 1432-1939
    Keywords: Phase polymorphism ; Density ; Mamestra brassicae ; Baculovirus ; Growth rate
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    Notes: Abstract This study examines phenotypic plasticity in relation to rearing density in larvae of the moth, Mamestra brassicae. Larval phase, growth rate, weight at moulting and susceptibility to disease were quantified when reared at five densities. Larvae develop more quickly, but attain a smaller size and are more susceptible to disease, when reared at high than at intermediate densities. They also exhibit a higher degree of melanisation than larvae reared at intermediate densities, or singly. A review of the literature suggests that a switch to a rapidly developing dark phase at high densities is a widespread phenomenon within the Lepidoptera. Rapid development at the expense of attaining a large size, and increased melanisation, are interpreted as adaptive responses to reach pupation before food supplies are depleted, as is likely when larval density is high. High susceptibility to viral infection at high density may be a result of physiological stress associated with rapid development, or due to a shift in allocation of resources from resistance to development: larvae that developed quickly were more susceptible to infection. Larvae reared singly appeared to be less fit than larvae reared at intermediate densities: they exhibited many of the characteristics of larvae reared at high density, particularly low weight, a right-hand skew in their weight frequency distribution, and high susceptibility to disease. I hypothesise that expression of resistance may be phenotypically plastic with regard to environment. Contact with other larvae may, up to a point, stimulate both growth and resistance to infection, for the risk of infection will increase with the density of conspecifics.
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    Oecologia 114 (1998), S. 226-235 
    ISSN: 1432-1939
    Keywords: Key words Arctic geese ; Food supply ; Growth rate ; Seasonal variation ; Timing of reproduction
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    Topics: Biology
    Notes: Abstract Even though growth rate is an important fitness component, it is still controversial to what extent parent birds adjust the timing of offspring hatch to natural variations in food supply to maximize offspring growth. We studied the role of food availability in explaining inter- and intra-seasonal variation of growth rate in goslings of greater snow geese over 5 years. The peak of hatching generally coincided with the peak of food availability. However, early-hatched goslings usually grew faster than birds hatched at the peak, which in␣turn grew faster than late-hatched goslings, although this phenomenon was not observed in all years. There was considerable variation in growth rate among the five years, the smallest goslings produced in the best year (1991) being larger than the largest goslings of the poorest year (1994). We developed three indices of food availability, based on the cumulative availability of plant biomass and nitrogen content during the growth period, and showed that the cumulative exposure to nitrogen biomass explained up to 43% of variation (intra- and inter-annual) in body size just before fledging. In years with good feeding conditions, early-hatched goslings had access to more nitrogen during their growing period than those hatching on or after the peak and they grew faster. In years of lower food availability, early-hatched goslings had no detectable advantage over peak- or late-hatched birds for access to protein-rich food and no seasonal decline in growth rate was observed. These results confirm the critical role of food supply in the seasonal variation of growth rate in Arctic-nesting geese.
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  • 38
    ISSN: 1432-1939
    Keywords: Key words Complex life cycle ; Developmental rate ; Growth rate ; Metamorphosis ; Amphibians
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    Topics: Biology
    Notes: Abstract  Amphibian larvae vary tremendously in size at metamorphosis and length of larval period. We raised pond-dwelling four-toed salamander (Hemidactylium scutatum) larvae to test two models that predict a larva’s age and size at metamorphosis. The Wilbur-Collins model proposes that the developmental rate of a larva responds to changes in growth rate in an adaptive manner throughout the larval period, and that metamorphosis can be initiated after a minimum size has been reached. The Leips-Travis or fixed-rate model states that developmental rate is set early in the larval period, perhaps by early growth rate or food availability and their positive correlation with developmental rate, and that changes in growth rate during the larval period affect size at metamorphosis, but have no effect on the age of an individual at metamorphosis. A modified version of the Wilbur-Collins model suggests that a larva’s developmental rate becomes fixed about two-thirds of the way through the larval period, with changes in growth rate after that point only affecting size at metamorphosis. Larvae were raised on eight different feeding regimes which created two constant and six variable growth histories. Growth history did significantly affect size at metamorphosis. However, an a posteriori statistical test revealed a group of seven and an overlapping group of six treatments with indistinguishable lengths of larval period, indicating a general picture of a fixed developmental rate regardless of growth history. This result is unique among similar studies on invertebrates, fish, and frogs. There was no association between early growth or food level and development rates. Neither the Wilbur-Collins nor the Leips-Travis fixed-rate models were supported. The invariable developmental rate of Hemidactylium and recent osteological evidence from the literature suggest that larvae begin the process of metamorphosis as soon as they hatch, probably a trait selected for by strong predation pressure in the aquatic environment. A variety of different approaches (ecological, developmental, phylogenetic) are necessary to fully evaluate the adaptive nature of the timing of transitions between life cycle stages.
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  • 39
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    Journal of molecular evolution 15 (1980), S. 79-101 
    ISSN: 1432-1432
    Keywords: Molecules ; Interstellar ; Chemistry ; Isotopes ; Solar system
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    Topics: Biology
    Notes: Summary The study of interstellar molecules broadly includes two areas of interest. One area uses the unique ability of molecules to act as probes of the physical conditions in the cold, dense, visually opaque component of the interstellar medium. The physical properties of this and other components of the interstellar medium are summarized. The other area deals with the chemistry of interstellar molecules, recent aspects of which are emphasized in this review. Gas-phase chemistry, shock chemistry, and grain surface chemistry are discussed in the context of recent observations. No present observations suggest that surface reactions are relevant, but neither can they be ruled out. Ion-molecule reactions are clearly operative, at least for the simpler species. Chemical isotope fractionation is reviewed, andd it is concluded that the complexities of the chemistry allow no cosmological conclusions to be drawn from observations of deuterium in interstellar molecules, while the presence of13C in interstellar molecules permits an estimate of the12C/13C ratio which is consistent with the current concepts of the nucleosynthesis history of the Galaxy. Possible connections between interstellar molecules and the early molecular history of the solar system are discussed.
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  • 40
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    Oecologia 101 (1995), S. 59-67 
    ISSN: 1432-1939
    Keywords: Dioecious plant ; Sex ratio ; Growth rate ; Differential flowering ; Biomass allocation
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    Topics: Biology
    Notes: Abstract Sex ratio and sexual dimorphism of Borderea pyrenaica, a long-lived dioecious geophyte endemic to the Pyrenees (north-east Iberian Peninsula), were examined in three alpine populations. In this species, age can be estimated and the sex of nonreproductive adult plants identified. Male plants attain sexual maturity earlier, flower more frequently and grow faster than female plants, whereas females allocate a higher biomass to reproduction than males. These results support the hypothesis that female plants incur a higher cost of sexual reproduction and that this higher cost is measurable as reduced vegetative growth and lower flowering frequency. Variation of sex ratio among young, intermediate and old adults within populations suggests, however, that this higher female reproductive investment does not result in sexual differences in mortality. The overall male-biased sex ratio in B. pyrenaica is mainly a consequence of the tendency of males to reproduce at an earlier age and more frequently than females.
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  • 41
    ISSN: 1432-1939
    Keywords: Key words Development rate ; Egg production ; Growth rate ; Reproductive tactics ; Romalea guttata
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    Notes: Abstract We tested alternative developmental hypotheses describing when during an insect oviposition cycle reproductive tactics are determined. Newly eclosed adult females of the grasshopper Romalea guttata were raised on eight different feeding treatments consisting of a low food diet, a high food diet, and changes from high to low food, or low to high food, at different times during the first oviposition cycle. When initial food availability was high, a decline in food availability 〉7 days after adult eclosion produced no significant increase in time to oviposition compared to constant high food. In contrast, when initial food availability was low, an increase in food availability as late as day 14 produced a significant decrease in time to oviposition compared to constant low food. Thus, time to oviposition is determined by feeding rate early in the oviposition cycle, but the time of this determination is later when food availability is lower. Masses of individual eggs were unaffected by these treatments. When initial food availability was high, a decrease in food availability on day 21 produced no significant change in numbers of eggs in a clutch compared to constant high food. In contrast, when initial food availability was low, an increase in food availability after day 7 produced no significant change in number of eggs in a clutch compared to constant low food. Changes in egg production resulted from oocyte resorption, which appeared to become unresponsive to food availability between day 14 and day 21. Our results refute the hypothesis that reproductive tactics are continuously flexible. Development toward oviposition seems to be structured so that reproductive tactics become independent of feeding late during the first oviposition cycle. Reproductive tactics become unresponsive to food at different times for groups initially receiving low or high food, suggesting that a particular developmental state, rather than some absolute time, marks the shift to development that is unresponsive to␣food. Plasticity in reproductive tactics appears to be␣controlled by hormones in a manner similar to the hormonal control of plasticity of metamorphosis in other insects.
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  • 42
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    Oecologia 88 (1991), S. 277-288 
    ISSN: 1432-1939
    Keywords: Body size ; Competition ; Fecundity ; Growth rate ; Stoneflies
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    Topics: Biology
    Notes: Summary We conducted experiments in replicated circular streams to measure the effect of intraspecific larval density on growth rates, size at emergence, timing of emergence, and fecundity of two species of predatory stoneflies (Megarcys signata and Kogotus modestus, Perlodidae). Early instars of both species showed no significant effect of intraspecific larval density on mean growth rates, despite the observation that in the absence of competitors stoneflies ate on average, significantly more prey (Baetis bicaudatus, Ephemeroptera, Baetidae) than in the presence of competitors. However, larval size of stoneflies held at higher densities (two per chamber) diverged over time, resulting in a greater size variability (coefficient of variation) among Kogotus than in treatments with low densities of stoneflies (one per chamber). The effect of doubling the density of early-instar Megarcys larvae was also asymmetrical, resulting in one larger and one smaller individual. In contrast, doubling the density of last-instar stoneflies whose feeding rates declined significantly prior to emergence had few measurable consequences, except that male Megarcys, which continued to feed throughout the last instar, had lower average feeding rates in high-density than in low-density chambers, and emerged at a significantly smaller mean size. We conclude that competition between early-instar stonefly larvae results in an asymmetry of body sizes, but that competitive effects are reduced as larvae slow or cease feeding before emergence. Since larger females of both stonefly species produced more eggs, the probable cost to females of early-instar larval competition was a reduction in their potential contribution of offspring to the next generation. The cost of attaining a smaller body size for male stoneflies is unknown; but if, as in many other insects, larger males have greater reproductive success, larval competition may increase the opportunity for sexual selection among males. This hypothesis remains to be tested experimentally.
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    Oecologia 72 (1987), S. 605-611 
    ISSN: 1432-1939
    Keywords: Andromonoecy ; Geographic variation ; Growth rate ; Life history ; Lomatium grayi ; Population divergence ; Sex ratio ; Umbelliferae
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    Topics: Biology
    Notes: Summary Populations of Lomatium grayi (Umbelliferae), an andromonoecious, perennial herb, differe in growth rates, flowering frequency, and survivorship. Effects of these different life histories on the ontogeny of sex expression were analyzed for plants from two populations grown from seedlings in a common garden and monitored for six years. Plants from Smoot Hill, Washington grew faster, had a higher probability of flowering at each age and size after the first year of growth, and a higher probability of flowering repeatedly among years than did plants from Clarkston, Washington. The proportion of plants producing some hermaphroditic flowers increased with plant size in both populations. Smoot Hill plants, however, were more likely to begin flowering as small, staminate plants than Clarkston plants. Clarkston plants did not begin flowering until they were older and larger, and most of these plants produced some hermaphroditic flowers when they began reproduction. The positive association between production of hermaphroditic flowers and both plant size and age was consistent with the hypothesis that hermaphroditic flowers are more costly to produce than staminate flowers. Although the populations did not differ in the total number of flowers per plant produced at any age or size, Smoot Hill plants consistently produced a lower percentage of hermaphroditic flowers than Clarkston plants at larger sizes and later ages. Consequently, selection for faster growth rates and higher flowering frequency at small sizes and early ages may have favored the more staminate-biased sex ratios in the Smoot Hill population.
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  • 44
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    Oecologia 82 (1990), S. 56-67 
    ISSN: 1432-1939
    Keywords: Optimal foraging ; Fitness ; Ground squirrels ; Energy intake ; Growth rate
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    Topics: Biology
    Notes: Summary Optimal diets were determined for each of 109 individual Columbian ground squirrels (Spermophilus columbianus) at two sites in northwestern Montana. Body mass, daily activity time, and vegetation consumption rates for individuals were measured in the field, along with the average water content of vegetation at each ground squirrel colony. I also measured stomach and caecal capacity and turnover rate of plant food through the digestive tract for individuals in the laboratory to construct regressions of digestive capacity as a function of individual body mass. Finally, I obtained literature estimates of average daily energy requirements as a function of body mass and digestible energy content of vegetation. These data were used to construct a linear programming diet model for each individual. The model for each individual was used to predict the proportion of two food types (monocots and dicots) that maximized daily energy intake, given time and digestive constraints on foraging. Individuals were classified as “optimal” or “deviating”, depending on whether their observed diet was significantly different from their predicted optimal diet. I determined the consequences of selecting an optimal diet for energy intake and fitness. As expected, daily energy intake calculated for deviators (based on their observed diet proportion) was less than that for optimal foragers. Deviating foragers do not appear to compensate for their lower calculated energy intake through other factors such as body size or physiological efficiency of processing food. Growth rate, yearly survivorship, and litter size increase with calculated energy intake, and optimal foragers have six times the reproductive success of deviators by age three. Optimal foraging behavior, therefore, appears to confer a considerable fitness advantage.
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  • 45
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    Oecologia 78 (1989), S. 508-512 
    ISSN: 1432-1939
    Keywords: Plasticity ; Growth rate ; Photosynthesis ; Abutilon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We present a method for quantifying the growth advantage, if any, that results from the plasticity of plant traits in response to growth in high vs. low resource levels. The method, which uses two phenotypes and two resource levels, quantifies the average advantage that a phenotype has, in its own set of conditions, over the other phenotype. The method is applied to the growth of two phenotypes of Abutilon theophrasti, induced by high and low light intensity, in response to two levels of incident light intensity. We calculated the growth advantage first using relative growth rate, and second using whole-plant photosynthetic assimilation rate, as the response variable. Then we used the photosynthetic responses to changes in light intensity to calculate changes in growth rates of each phenotype when exposed to a change in light conditions. These three quantifications of growth advantage broadly agree with one another. Despite the great plasticity of its traits induced by growth in high vs. low light intensity, whole-plant plasticity did not allow Abutilon theophrasti to exhibit a significant growth advantage under these conditions. Indeed, the relative growth rate of the low light phenotype greatly exceeded that of the high light phenotype in high incident light conditions. This may have resulted from the higher leaf area ratio of the low light phenotype. Furthermore, the high light phenotype had significantly greater transpiration rate in both light conditions. For these reasons we suggest that light-induced plasticity of traits in Abutilon theophrasti may confer advantage in response to the variation in vapor pressure deficit that is associated with variation in light intensity. Light-induced plasticity may also be advantageous because under high incident light conditions the high-light phenotype has greater reproductive allocation than the low-light phenotype.
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    Oecologia 96 (1993), S. 232-238 
    ISSN: 1432-1939
    Keywords: Temperature ; Seedling mortality ; Growth rate ; Tropical rainforest ; Ecological niche
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Controlled environment treatments were applied to assess the effects of temperature on the seedling mortality and growth rates of Toona australis and Flindersia brayleyana, two tropical rainforest tree species from northeast Queensland, Australia. Past workers have assigned these two species to the same ecological niche in terms of their response to canopy disturbance and gap-phase regeneration; however, their geographic ranges are very different. The hypothesis was that the species confined to the warm tropics (F. brayleyana) would have higher seedling mortality and a slower growth rate at lower temperatures than the species that occurs over a wide latitudinal range from the warm tropics to cooler temperate environments (T. australis). Significant differences were found in the growth rates of these two species in the warm (29/22° C) and cool (22/10°C), but not the intermediate (24/16° C), day/night temperature regimes. Their growth rates both decreased with decreasing temperature, but the decrease was significantly less for F. brayleyana which had the faster growth rate and lower seedling mortality in the cool regime. These results led to the rejection of the hypothesis and a test of the assignment of these two species to the same ecological niche. The test involved monitoring their growth to sapling-size in the intermediate temperature regime together with four other co-occurring tropical rainforest tree species belonging to different ecological niches. The growth rates and proportions of above-ground biomass allocated to woody tissue distinguished T. australis and a fast-growing pioneer species from F. brayleyana and three primary forest species. The stem heights and aboveground biomass of T. australis and the pioneer species exceeded the other four species by factors ranging from two to five. It is concluded that T. australis does not belong to the same ecological niche as F. brayleyana, and it is recommended that more research be conducted on the ecotypic temperature responses of the taxon T. australis.
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  • 47
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    Oecologia 70 (1986), S. 106-112 
    ISSN: 1432-1939
    Keywords: Chrysomela ; Salix ; Elevation difference ; Predator protection ; Growth rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Adults and larvae of Chrysomela aenicollis (Coleoptera: Chrysomelidae) feed on foliage of Salix species (Salicaceae) between 2,400–3,400 m above sea level in the eastcentral Sierra Nevada mountains of California. We predicted that (1) cold climatic conditions would be a more frequent source of mortality at higher elevations, (2) mildweather agents of mortality such as predation should be more severe at lower elevations, and (3) populations of C. aenicollis would be adapted to the local selective regime at each elevation. We tested these predictions in 1984 and 1985 by transferring over 6,000 eggs and larvae within and between two sites at 2,810 and 3,240 m elevation above sea level. During mild summer weather at both sites, survivorship on Salix branches isolated by a barrier of sticky resin was similar to that on control branches, and we concluded that aerial predators were the primary cause of mortality. At least one major predator, a solitary wasp (Symmorphus sp., Hymenoptera: Eumenidae), was specifically associated with C. aenicollis at the lower site, where beetle mortality was highest. At both sites in 1984 and 1985, larvae originating from the lower site remained in aggregations and survived more frequently than larvae from the upper site, suggesting that they are better defended against predators. During a storm with cold weather late in the 1984 season, larvae and pupae died more frequently at the upper site, and there was a marginally significant trend (P〈0.1) for the lower site individuals to die more frequently than upper site larvae during the cold storm. Upper site larvae grew approximately 10% faster than lower site larvae at the lower site and under controlled conditions in the laboratory. These findings indicate that upper and lower site populations were adapted to the local selective regime, which suggest how populations of montane phytopagous insects may adapt to changing elevations.
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  • 48
    ISSN: 1432-1939
    Keywords: Life history ; Countergradient variation ; Growth rate ; Seasonality ; Latitudinal variation
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    Topics: Biology
    Notes: Summary How do organisms adapt to the differences in temperature and length of the growing season that occur with latitude? Among Atlantic silversides (Menidia menidia) along the east coast of North America, the length of the first growing season declines by a factor of about 2.5 with increasing latitude. Yet body size at the end of the first growing season does not decline. High-latitude fish must, therefore, grow faster within the growing season than do low-latitude fish. This geographical pattern has a genetic basis. Laboratory experiments on fish from six different locations revealed a latitudinal gradient in the capacity for growth (i.e., maximum growth potential). In two subsequent experiments using fish from Nova Scotia (NS), New York (NY) and South Carolina (SC) that had been separately reared in a common environment for several generations, differences in growth rate among populations were highly significant. The rank order was NS〉NY〉SC, but the difference among populations depended on temperature. High-latitude fish outperformed those from low latitudes primarily at the high temperatures that low-latitude fish would be expected to experience most often in nature. These results suggest that instead of being adapted for growth at low temperatures, fish from high latitudes are adapted for rapid elevation of growth rate during the brief interval of the year when high temperatures occur. Selection on growth rate results from sizedependent winter mortality: the importance to winter survival of being large increases with latitude but the length of the growing season simultaneously decreases. The end result is countergradient variation in growth rate, a phenomenon that may be much more widespread than currently recognized.
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    Calcified tissue international 23 (1977), S. 39-44 
    ISSN: 1432-0827
    Keywords: Dental cementum ; Collagen ; Protein ; Chemistry
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    Topics: Biology , Medicine , Physics
    Notes: Summary Cyanogen bromide (CNBr) peptides were prepared of the insoluble collagen of bovine dental cementum. Following chromatographic separation, the peptides were identified by their amino-acid composition. Type I collagen ([α1(I)]2α2) accounted for more than 90% of the organic matrix, while Type III collagen ([α1(III)]3) was present at a level of approximately 5%. Amino-acid analyses revealed that the CNBr peptides from α1(I) and α2 chains of cementum closely resembled the corresponding peptides from calf skin. The only systematic difference was a higher level of hydroxylation of prolyl and lysyl residues of the cementum peptides.
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    Calcified tissue international 7 (1971), S. 150-162 
    ISSN: 1432-0827
    Keywords: Uranium ; Bone ; Distribution ; Fission ; Chemistry
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    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une concentration moyenne de 2.4×10−8 g U/g de cendre a été obtenue à partir de l'os humain normal. La microdistribution de l'uranium dans l'os indique que cet élément est surtout limité à surface de l'endoste et, en particulier, aux surfaces de l'os lamellaire et aux parois des canaux de Havers, ouverts dans l'os corticol. Cette répartition suggère que l'uranium se présente sous une forme chimique impropre à son incorporation dans l'apatite osseux: il ne semble donc pas exister une distribution diffuse significative de l'uranium dans l'os.
    Abstract: Zusammenfassung Eine mittlere Konzentration von 2,4×10−8 g Uran/g Asche wurde in normalen menschlichen Knochen gefunden. Die Feinverteilung von Uran im Knochen zeigt, daß dieses Element hauptsächlich an der endostalen Oberfläche vorkommt, insbesondere an der Oberfläche des trabeculären Knochens und an den Wänden der offenen Haversschen Kanäle im kortikalen Knochen. Diese Verteilung läßt vermuten, daß Uran in einer chemischen Form vorliegt, welche sich für den Einbau in das Knochenapatit nicht eignet. Daraus folgt, daß keine signifikante diffuse Verteilung des Urans innerhalb des Knochens vorliegt.
    Notes: Abstract A mean concentration of 2.4×10−8 g U/g ash has been obtained for normal human bone The microdistribution of uranium in bone indicates that this element is mainly restricted to endosteal surfaces; in particular the surfaces of trabecular bone and the walls of open Haversian canals in cortical bone. This distribution suggests that uranium is present in a chemical form that is not acceptable for incorporation into bone apatite and consequently there does not appear to be a significant diffuse distribution of uranium throughout bone.
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  • 51
    ISSN: 1432-0827
    Keywords: Morphology ; Glycosaminoglycans ; Cartilage ; Chemistry ; Audioradiography ; Healing
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    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une perte de substance ostéo-cartilagineuse, de taille limitée et identique, est réalisée chez le lapin adulte et la cicatrisation est étudiée histologiquement et par autoradiographie après marquagein vitro au35S-sulfate. Une analyse microchimique est pratiquée pour le contenu et la composition en glycosaminoglycanes. 1. Entre la première semaine et la 4ème et 8ème semaine, un tissu conjonctif non-métachromatique se différencie en un cartilage métachromatique et la quantité de sulfate de chondroitine augmente de façon significative aux dépens des glycoprotéines. 2. Jusqu'à la 4ème semaine, la perte de substance est surtout comblée par de l'os néoformé: après cette période, la région est comblée au delà de la limite de la surface articulaire. 3. Le cartilage hyalin, ressemblant morphologiquement, autoradiographiquement et chimiquement au cartilage articulaire, en ce qui concerne la distribution en glycosaminoglycanes, constitute la surface articulaire de la perte de substance comblée dans un tiers des cas après 8 semaines. Le cartilage hyalin s'observe surtout dans les régions où de l'os néoformé a comblé la cavité médullaire. 4. Dans les deux tiers des cas, après 8 semaines, les surfaces articulaires des zones comblées comportent, non seulement du cartilage, mais aussi du tissu fibreux se formant essentiellement sur les parties latérales et dans les régions, où la cavité médullaire, fliant face, à la surface articulaire, n'a pas été comblée par du tissue osseux. La fraction glycoprotéique augmente par rapport à la fraction chondroitine sulfate. 5. Dans la majorité des cas, après 20 semaines, le cartilage néoformé subit des phénomènes dégénératifs, qui se traduisent par une diminution en chondroitine sulfate.
    Abstract: Zusammenfassung Bei ausgewachsenen Kaninchen wurde ein begrenzter, standardisierter, osteochondraler Defekt hervorgerufen, und das regenerierte Gewebe wurde histologisch und autoradiographisch durch Markierung in vitro mit35S-Sulfat und durch mikrochemische Bestimmung des Gehaltes und der Zusammensetzung der Glykosaminglykane untersucht. Die wichtigsten Befunde waren: 1. Zwischen 1 und 4–8 Wochen veränderte sich nichtmetachromatisches Bindegewebe zu metachromatisch gefärbtem Knorpel, und der Anteil an Chondroitin-Sulfat nahm auf Kosten der Glykoproteine signifikant zu. 2. Bis zu 4 Wochen war der Hauptteil des defekten Gebietes mit neugebildetem Knochen gefüllt; nach dieser Zeit lag dieser Bezirk oberhalb der Verknöcherungsgrenze in Richtung der Gelenkoberfläche. 3. Nach 8 Wochen bestand die Gelenkoberfläche des defekten Gebietes in einem Drittel der Fälle aus hyalinem Knorpel, der morphologisch, autoradiographisch und chemisch dem Gelenkknorpel in Bezug auf die Verteilung von Glykosaminoglykanen glich. Hyaliner Knorpel wurde hauptsächlich an Stellen beobachtet, wo neugebildeter Knochen die Markhöhle geschlossen hatte. 3. Nach 8 Wochen bestand die Gelenkoberfläche des defekten Gebietes in einem Drittel der Fälle aus hyalinem Knorpel, der morphologisch, autoradiographisch und chemisch dem Gelenkknorpel in Bezug auf die Verteilung von Glykosaminoglykanen glich. Hyaliner Knorpel wurde hauptsächlich an Stellen beobachtet, wo neugebildeter Knochen die Markhöhle geschlossen hatte. 4. Nach 8 Wochen bestanden Teile der Gelenkoberfläche des Defektes in zwei Dritteln der Fälle nicht nur aus Knorpel, sondern auch aus fibrösem Gewebe, welches vor allem in den seitlichen Teilen des Defektes und an Stellen vorlag, wo die Markhöhle gegenüber der Gelenkoberfläche nicht mit Knochengewebe verschlossen worden war. Die Glykoproteinfraktion nahm im Vergleich zur Chondroitin-Sulfatfraktion zu. 5. Nach 20 Wochen zeigten sich in den meisten Fällen bei neugebildetem Knorpel degenerative Veränderungen, welche durch eine gewisse Abnahme des Chondroitin-Sulfats wiedergegeben wurden.
    Notes: Abstract A limited, standardized osteochondral defect was created in adult rabbits and the regenerated tissue was examined histologically and autoradiographically after labellingin vitro with35S-sulphate, and microchemically for its content and composition of glycosaminoglycans. The principal findings were: 1. Between 1 week and 4 to 8 weeks, non-metachromatic connective tissue differentiated to metachromatically stained cartilage, and the proportion of the chondroitin sulphate increased significantly at the expense of the glycoproteins. 2. Up to 4 weeks, the major part of the defect area was filled with newly formed bone; after this time, the area lay above the level of the “tidemark”, towards the articular surface. 3. Hyaline cartilage with morphological, autoradiographic and chemical resemblance to the articular cartilage in terms of the distribution of glycosaminoglycans constituted the articular surface of the defect area in one-third of the cases at observation times after 8 weeks. Hyaline cartilage was observed mainly in areas where newly formed bone had closed the medullary cavity. 4. In two-thirds of the cases, after 8 weeks, parts of the articular surface of the defect consisted not only of cartilage but also of fibrous tissue, occurring mainly in the lateral parts of the defect and in areas where the medullary cavity facing the articular surface had not been sealed by bone tissue. The glycoprotein fraction increased relative to the chondroitin sulphate fraction. 5. In most cases after 20 weeks, newly-formed cartilage underwent degenerative changes, which were reflected in some reduction of the chondroitin sulphate.
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    Calcified tissue international 10 (1972), S. 82-90 
    ISSN: 1432-0827
    Keywords: Calcium ; Phosphate ; Precipitation ; Kinetics ; Chemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La cinétique de la formation et de la transformation des précipités de phosphate de calcium, obtenus en mélangeant de volumes égaux de solutions à 6×10−3 M de calcium total et/ou phosphate total est étudiée à 25°C. Les solutions de phosphate sont préajustées à un pH de 7.4. Les changements de pH et de turbidité des solutions sont suivis simultanément en fonction du temps. Les précipités sont isolés à des intervalles de temps variables et caractérisés par diverses méthodes physico-chimiques. Initialement un précipité avec un rapport molaire Ca/P de 1.5, amorphe aux rayons X et en diffraction électronique, est formé. Le spectre IR indique la présence de PO 4 3− et de HPO 4 2− . Après une période métastable, on observe la précipitation d'un matériel cristallin dans ou sur la phase amorphe. Vingt quatre heures après préparation de l'échantillon les précipités présentent surtout les caractères du phosphate octocalcique.
    Abstract: Zusammenfassung Die Kinetik der Bildung und Transformation von Calciumphosphat-Niederschlägen wurde bei 25°C untersucht. Es wurden dazu gleiche Volumen von Lösungen gemischt, bei einer Konzentration von 6×10−3M totales Calcium und/oder totales Phosphat. Die Phosphatlösungen wurden zuerst auf pH 7,4 eingestellt. Veränderungen des pH und Trübung der Lösungen wurden gleichzeitig als eine Funktion der Zeit aufgezeichnet. Niederschläge wurden in verschiedenen Zeitintervallen isoliert und mit verschiedenen physiko-chemischen Methoden charakterisiert. Am Anfang wurde ein Niederschlag mit einem molaren Ca/P-Verhältnis von 1,5, im Röntgenbild und in der Elektronendiffraktion amorph, gebildet. Infrarotspektren deuteten die Anwesenheit von PO 4 3− - und HPO 4 2− -Ionen an. Nach einer metastabilen Periode erfolgte ein Niederschlag aus kristallinem Material innerhalb oder auf der amorphen Substanz. 24 Std nach der Herstellung der Proben zeigten die Niederschläge in der Hauptsache die Charakteristiken von Octocalciumphosphat.
    Notes: Abstract The kinetics of the formation and transformation of calcium phosphate precipitates obtained by mixing equal volumes of solutions, 6×10−3 M in total calcium and/or total phosphate was investigated at 25°. The phosphate solutions were preadjusted to pH 7.4. Changes of the pH and turbidity of the solutions were followed simultaneously as a function of time. Precipitates were isolated at various time intervals and characterized by different physicochemical methods. Initially a precipitate with a molar Ca/P ratio of 1.5, amorphous to X-ray and electron diffraction was formed. IR spectra indicated the presence of PO 4 3− and HPO 4 2− ions. After a period of metastability, precipitation of a crystalline material within or upon the amorphous matter occurred. Twenty four hours after sample preparation the precipitates showed mainly the characteristics of octacalcium phosphate.
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    Calcified tissue international 14 (1974), S. 3-14 
    ISSN: 1432-0827
    Keywords: Hydroxyapatite ; Mineral ; Phase ; Chemistry ; Synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des diagrammes de phase d'équilibre ont été déterminés pour le système CaO-P2O5-H2O en utilisant des techniques de synthèse hydrothermique au cours de variatio nsde température allant de 300–600° et 2 Kb H2O de pression. De l'hydroxyapatite bien cristallisé a été synthétisé et caractérisé. De faibles variations de paramètres de la maille cristalline, liées à la température de synthèse et composition globale du matériel initial, ont été déterminées. Des conditions chimiques précises sont nécessaires pour obtenir de l'apatite, en tant que seule phase solide en équilibre dans la solution. Les résultats de diagramme de phase d'équilibre sont comparés avec ceux obtenus dans des milieux synthétiques.
    Abstract: Zusammenfassung Es wurden Gleichgewichts-Phasendiagramme für das System CaO-P2O5-H2O bestimmt, indem hydrothermale Synthese-Techniken im Temperaturbereich von 300–600° und bei einem Druck von 2 Kb H2O verwendet wurden. Es wurde gut-kristallisiertes Hydroxyapatit erzeugt und charakterisiert. Es wurden geringe Unterschiede in den Parametern der Zelleinheiten festgestellt, welche von der angewandten Temperatur und der Zusammensetzung des Startmaterials abhingen. Es waren genaue chemische Bedingungen nötig, um Apatit als die einzige feste Phase im Gleichgewicht mit der Lösung zu erhalten. Die Resultate der Gleichgewichts-Phasendiagramme werden mit früheren Untersuchungen mit der Synthesetechnik verglichen.
    Notes: Abstract Equilibrium phase diagrams have been determined for the system CaO-P2O5-H2 using hydrothermal synthesis techniques in the temperature range 300–600° and 2 Kb H2O pressure. Well-crystallized hydroxyapatite has been produced and characterized. Small variations in unit cell parameters dependent on temperature of synthesis and bulk composition of the starting materials have been determined. Precise chemical conditions were required to obtain apatite as the only solid phase in equilibrium with solution. Equilibrium phase diagram results are compared with previous synthetic investigations.
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    Calcified tissue international 13 (1973), S. 259-270 
    ISSN: 1432-0827
    Keywords: Fluorapatite ; Exchange ; Chemistry ; Crystallography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Un échantillon minéral provenant de Burgess, Canada s'est révélé être un speciment exceptionnellement pur de fluoroapatite après analyse chimique et cristallographique. La composition globale de cet échantillon est la suivante: $$(Ca^2 )9.98(Sr^{2 + } ,Na^ + ,K^ + ,Mg^{2 + } )0.02(PO_4^{3 - } )5.98(HCO_3^ - ,CO_3^{2 - } )0.02(F^ - )2$$ . L'axe cristallographique C est de 6.865 A et l'axe a de 9.374 A. Des expériences d'échanges réalisés à l'aide de45Ca,32P et18F indiquent la présence de gros cristallites de surface spécifique de l'ordre de 1 m2/g. Il apparait que l'interprétation physique des processus d'échange ne nécessite pas l'existence de compartiments séparés, avec chacun son propre facteur cinétique, les échanges semblent être simplement liés à un changement exponentiel dans l'énergie libre de la réaction. Pour la réaction suivante: $$(Ca)_5 (PO_4 )_3 OH solide + (F^ - ) \rightleftarrows (Ca)_5 (PO_4 )_3 F solide + (OH^ - )$$ , la constante thermodynamique de 101.26 a été calculée, suggérant que le fluorapatite se forme toujours aux dépens de l'hydroxyapatite dans des conditions physiologiques. Cette transformation se continue en abaissant le pH.
    Abstract: Zusammenfassung Eine Mineralprobe aus Burgess, Kanada, erwies sich nach chemischer und kristallographischer Analyse als außergewöhnlich reines Fluorapatit. Die Gesamtzusammensetzung entspricht: $$(Ca^{2 + } )_{9,98} (Sr^{2 + } ,Na^ + ,K^ + ,Mg^{2 + } )_{0,02} (PO_4^{3 - } )_{5,98} (HCO_3^ - ,CO_3^{2 - } )_{0,02} (F^ - )_2 $$ . Die kristallographische c-Achse wurde bestimmt und ergab 6,865 Å, und die a-Achse ergab 9,374 Å. Austauschwerte, welche durch Anwendung von45Ca,32P und18F erhalten wurden, deuteten auf große Kristalliten mit einer spezifischen Oberfläche von ca. 1 m2/g. Die Befunde deuten darauf hin, daß für die physikalische Erklärung des Austauschvorganges keine separaten Kompartimente mit eigenen kinetischen Faktoren nötig sind, sondern daß der Austausch mit dem exponentiellen Wechsel in der freien Energie der Reaktion in einfacher Beziehung steht. Für die Reaktion $$(Ca)_5 (PO_4 )_3 OH_{in fester Form} + (F^ - ) \rightleftarrows (Ca)_5 (PO_4 )_3 F_{in fester Form} + (OH^ - )$$ wurde als thermodynamische Konstante 101,26 errechnet, was darauf deutet, daß unter physiologischen Bedingungen immer Fluorapatit auf Kosten von Hydroxyapatit entsteht. Diese Umwandlung wird erhöht, wenn das pH erniedrigt wird.
    Notes: Abstract A mineral specimen from Burgess, Canada, proved upon chemical and crystallographic analyses to be an exceptionally pure sample of fluorapatite. The over-all composition corresponds to $$(Ca^{2 + } )_{9.98} (Sr^{2 + } ,Na^ + ,K^ + ,Mg^{2 + } )_{0.02} (PO_4^{3 - } )_{5.98} (HCO_3^ - ,CO_3^{2 - } )_{0.02} (F^ - )_2 $$ . The crystallographic c-axis was determined to be 6.865 Å, and the a-axis 9.374 A. Exchange data obtained by employing45Ca,32P, and18F indicate the presence of large crystallites with a specific surface of the order of 1 m2/g. It is indicated that the physical interpretation of the exchange process does not require the existence of separate departments, each with its own kinetic factor, but that the exchange may be simply related to the exponential change in the free energy of the reaction. For the reaction $$(Ca)_5 (PO_4 )_3 OH_{solid} + (F^ - ) \rightleftarrows (Ca)_5 (PO_4 )_3 F_{solid} + (OH^ - )$$ the thermodynamic constant has been calculated to be 101.26, implying that fluorapatite always will form at the expense of hydroxyapatite under physiologic conditions. This transformation will be furthered by lowering the pH.
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    Calcified tissue international 23 (1977), S. 87-94 
    ISSN: 1432-0827
    Keywords: Calcium ; Osteoporosis ; Lactation ; Chemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The calcium homeostatic mechanism was challenged in adult female rats by feeding them a calcium-deficient diet containing oxalate, and by subjecting them to pregnancy and lactation. The regimen caused a substantial weight loss, especially in those animals which reared their young well. Severe hypocalcaemia was observed in the lactating rats. Serum-P was slightly elevated. The content of hydroxyproline in serum was considerably elevated, reflecting the degree of calcium deprivation. Serum proteins were least influenced. The calcium depriving regimen reduced the growth of long bones, but did not stop it. The ash content of the bones was considerably reduced, the degree of reduction depended on the degree of calcium deprivation. Ash as percentage of total bone organ was reduced, but not to the same extent as total ash. Analyses of different parts of femur showed that the proximal and distal parts had lost more bone mineral than the diaphyseal shaft. The ash content of cortical bone tissue from the femur was estimated by a volumetric method. No differences were observed between test groups and controls, indicating that no measurable amounts of bone mineral had been removed from the walls of the vascular canals or by osteocytic osteolysis. Planimetric determinations on cross sections from femora disclosed that a great amount of bone had been removed from the endosteal surface of the diaphysis, while the periosteal surface demonstrated reduced bone apposition.
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    Calcified tissue international 12 (1973), S. 125-136 
    ISSN: 1432-0827
    Keywords: Mineralization ; Molt ; Isopod ; Chemistry ; Light microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Au cours de la phase inhabituelle de mue d'un isopode d'eau courante,Lirceuts brachyrus, la moitié postérieure de l'exosquelette est éliminée 24 heures avant la moitié antérieure. A ce stade, une reminéralisation se développe dans la partie postérieure alors que la partie antérieure est dans un stade de pré-mue. Le pourcentage de différence en calcium dans les deux moitiés à mi-mue et mue complète est respectivement de 22% (p〈0.01) et 33% (p〈0.01), indiquant une complexation du calcium pendant la mue. La rapidité de la reminéralisation est illustrée par le fait que le contenu minéral total double dans la partie postérieure entre la mi-mue et la mue totale et dans la partie antérieure entre la fin de la mue et un jour après. Le carbonate de calcium, sous forme de calcite, a pu être identifié par diffraction électronique de coupes fines des téguments.
    Abstract: Zusammenfassung Während der ungewöhnlichen Häutungssequenz des Frischwasser-IsopodenLirceus brachyurus (Harger) wird die hintere Hälfte des äußeren Skeletts 24 Std vor der vorderen Hälfte abgestoßen. In der halbgehäuteten Phase erfolgt Remineralisation im hinteren Teil, während der vordere Teil in einem Vorhäutungszustand ist. Der prozentuale Unterschied des Calciums in den zwei Hälften bei Halb- und Vollhäutungszustand ist 22% (p〈0,01) bzw. 33% (p〈0,01), was andeutet, daß Calcium während der Häutung abgesondert wird. Die Geschwindigkeit der Remineralisation erhellt aus der Tatsache, daß sich der Gesamtmineralgehalt im hinteren Teil zwischen Halt- und Vollhäutung, in der vorderen Hälfte jedoch zwischen Endhäutung und einem Tag nach der Häutung verdoppelt. Calciumcarbonat in kristalliner Calcitform wurde mittels Elektronendiffraktion von dünnen Hautschnitten nachgewiesen.
    Notes: Abstract During the unusual molt sequence of the fresh-water isopod,Lirceus brachyrus (Harger), the posterior half of the exoskeleton is shed 24 hours before the anterior half. At the half-molt stage, occurs in the posterior part while the anterior portion is in a pre-molt condition. The percentage difference in calcium in the two halves at half-molt and full-molt is22 (p〈0.01) and33 (p〈0.01) respectively, an indication that calcium is sequestered during The rapidity of remineralization is illustrated by the fact that the total mineral content doubles in the posterior part between half and full molt and in the anterior half between the end of molt and one day after ecdysis. Calcium carbonate in the calcite cystalline form was demonstrated by electron diffraction of thin sections of the integument.
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    Calcified tissue international 16 (1974), S. 145-152 
    ISSN: 1432-0827
    Keywords: EHDP ; Bone ; Chemistry ; Serum ; Rabbits
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    Topics: Biology , Medicine , Physics
    Notes: Abstract The effects of disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) on bone and serum chemistry were investigated in adult rabbits. EHDP was administered by subcutaneous injection at doses of 0.25, 2.5 and 10 mg/kg body weight/day for of 28 days. Blood samples were obtained weekly from each rabbit and serum levels of total calcium, ionized calcium, inorganic phosphate and alkaline phosphatase were determined. At the end of the treatment period all rabbits were sacrificed and the tibiae removed for chemical analysis and histological evaluation. The effect of EHDP administration on serum chemistry was both dose- and time-related. The highest of the three doses, 10 mg/kg/day, resulted in a time-related decrease in total serum calcium. This dose also caused a rapid but transient reduction in serum ionized calcium. The effect of EHDP on serum inorganic phosphate was biphasic. Administration of 2.5 mg/kg/day resulted in a time-related elevation in this parameter, whereas the 10 mg/kg/day dose resulted in a time-related hypophosphatemic response. There were no significant drug-related changes in tibial fat-free dry weight, ash weight, total calcium or total phosphorus values. However, administration of 2.5 and 10 mg/kg/day EHDP resulted in increased osteoid tissue as measured histologically. These results are compared with data from other EHDP studies, and discussed in relation to the maturity and growth-state of the experimental animals.
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    Calcified tissue international 8 (1971), S. 197-210 
    ISSN: 1432-0827
    Keywords: Fluorescence ; Calcium ; Collagen ; Chemistry ; Bone ; Dentine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des composants fluorescents de l'os et la dentine sont séparés des hydrolysats alcalins de leur marice sur des colonnes Sephadex C25 CM d'échange cationique. Les concentrations en fluorescence et le spectre d'excitation (λ max 330 nm) et d'émission (λ max 395 nm) sont les mêmes que ceux observés au niveau des matrices intactes et gélatinisées. Les paramètres de fluorescence ne sont pas altérés par hydrolyse. La filtration sur gel à l'aide de colonnes Sephadex G 10 perment de différencier le matériel isolé en deux composants, ayant la même fluorescence et la même absorption UV. La fluorescence est indépendante de pH de 3.5–9.5. Des études de dialyse et de filtration sur gel de matrices gélatinisées indiquent une association étroite du matériel fluorescent avec les chaines polypeptidiques de collagène.
    Abstract: Zusammenfassung Fluorescierende Bestandteile aus Knochen und Dentin wurden in Sephadex C25 CM Kationen-Austauschersäulen von alkalischen Hydrolysaten ihrer Matrices getrennt. Die Fluorescenzintensitäten sowie die Erregungs- (λ max 330 nm) und Emissions- (λ max 395 nm) Spektren waren dieselben wie bei intakten und gelatinisierten Matrices. Die Fluorescenzparameter wurden durch die Hydrolyse nicht verändert. Eine Gelfiltration über Sephadex-G10-Säulen trennte das isolierte Material in 2 Komponenten auf, welche gleiche Fluorescenz- und UV-Absorptionseigenschaften zeigten. Im pH-Bereich zwischen 3,5 und 9,5 war die Fluorescenz unabhängig vom pH. Dialysierversuche sowie Gelfiltrationsexperimente mitden gelatinisierten Matrices zeigten eine starkgefügte Bindung des fluorescierenden Materials mit den Polypeptidketten des Kollagens.
    Notes: Abstract Fluorescent components in bone and dentine were separated from alkaline hydrolysates of their matrices on Sephadex C25 CM cationic exchange columns. The fluorescence levels, and the excitation (λ max 330 nm) and emission (λ max 395 nm) spectra, were the same as those observed in the intact and gelatinised matrices. The fluorescence parameters were unaltered by the hydrolysis procedure. Gel filtration on Sephadex G. 10 columns further resolved the isolated material into two components with the same fluorescence and UV absorption properties. The fluorescence was independent of pH over the range 3.5–9.5. Dialysis and gel filtration studies on the gelatinised matrices indicated a firmly-bonded association of the fluorescent material with the collagen polypeptide chains.
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    Pure and applied geophysics 118 (1980), S. 128-151 
    ISSN: 1420-9136
    Keywords: Galactic cosmic rays ; Solar proton events ; Particle precipitation ; Chemistry
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    Topics: Geosciences , Physics
    Notes: Abstract An assessment is made of the relative contribution of certain classes of energetic particle precipitation to the chemical composition of the middle atmosphere with emphasis placed on the production of odd nitrogen and odd hydrogen species and their subsequent role in the catalytic removal of ozone. Galactic cosmic radiation is an important source of odd nitrogen in the lower stratosphere but since the peak energy deposition occurs below the region where catalytic removal of O3 is most effective, it is questionable whether this mechanism is important in the overall terrestrial ozone budget. The precipitation of energetic solar protons can periodically produce dramatic enhancement in upper stratospheric NO. The long residence time of NO in this region of the atmosphere, where catalytic interaction with O3 is also most effective, mandates that this mechanism be included in future modelling of the global distribution of O3. Throughout the mesosphere the precipitation of energetic electrons from the outer radiation belt (60°≲Λ≲70°) can sporadically act as a major local source of odd hydrogen and odd nitrogen leading to observable O3 depletion. Future satellite studies should be directed at simultaneously measuring the precipitation flux and the concomitant atmosphere modification, and these results should be employed to develop more sophisticated models of this important coupling.
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  • 60
    ISSN: 0931-1890
    Keywords: Key words Stem growth ; Eucalyptus globulus ; Eucalyptus nitens ; Dendrometer ; Growth rate
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    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Daily increments in stem radius were determined from hourly dendrometer measurements in each of three irrigated Eucalyptus nitens and E. globulus trees. Multiple regressions determined from daily weather variables accounted for 40–50% of the variance in increment. The use of weather variables lagged by 1–2 days increased the variance explained. The diurnal variation in stem radius was resolved into three mathematically defined phases: shrinkage, recovery and increment. The positive daily net increment in stem radius, by definition, occurred in the increment phase. Average weather conditions during this phase (predominantly night-time) did not explain any more variance in increment than the average daily conditions, determined over a 24 h period. Daily increment was resolved into a rate of stem radius increase during the increment phase and the duration (hours) of that phase. Significant species by month interactions were evident with growth in summer characterised by faster rates of stem expansion over shorter time periods within each diurnal cycle. E. nitens tended to have longer increment phases in spring and autumn, and faster phase rates in autumn than E. globulus. Interactions between weather variables and cambial growth were complicated and varied over the year. The correlation between temperature and stem growth varied from positive in spring to zero or negative during summer. The data indicate a need to understand weather-by- climate interactions at the level of whole tree physiology in order to fully understand the effect of weather on cambial activity and therefore stem increment and wood properties.
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    Calcified tissue international 10 (1972), S. 171-197 
    ISSN: 1432-0827
    Keywords: Amorphous ; Crystalline ; Calcium phosphate ; Chemistry ; Composition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des échantillons non lavés de phosphate de calcium amorphe (ACP) contiennent une fraction labile, non remplaçable, riche en phosphate acide avec un rapport Ca/P faible: cette fraction est perdue de façon irréversible au cours du lavage. De l'ACP frais, précipité entre pH 6.6–10.6, varie dans un rapport molaire Ca/P de 1.18 à 1.50 et dans un rapport HPO 4 2− /P total de 33.0% à 10.1%. A pH 7.40, de l'ACP frais a un rapport molaire Ca/P de 1.36±0.02 et contient 22.8 (±2.2)% HPO 4 2− . Les résultats obtenus avec du précipité non lavé ne peuvent s'expliquer par du Ca2+ emprisonné et de l'HPO 4 2− ou du Na+, Cl− et CO 3 2− exogènes. Les phosphates de calcium amorphes constituent une classe de sels ayant des caractères chimiques variables et des propriétés physiques identiques, comparables au verre. Le CaHPO4·xH2O non cristallin peut être un ACP, surtout au cours des phases précoces de formation. A des pH physiologiques, l'ACP se transforme en petits cristaux applatis contenant de fortes quantités de phosphate acide facilement remplaçable. Le fait de laver la couche de surface produit un changement chimique dans les nouveaux cristaux: des cristaux non lavés donnent des diagrammes de diffraction d'apatite peu cristallins, ainsi que des spectres infra-rouges peu nets, intermédiaires entre des apatites et du phosphate octocalcique. Des explications structurales sont proposées et les compositions minérales amorphe/cristalline de l'os et du cartilage sont recalculées.
    Abstract: Zusammenfassung Ungewaschene Proben von amorphem Calciumphosphat (ACP) enthalten eine unersetzliche labile Fraktion, welche reich an saurem Phosphat ist und ein niederes Ca/P-Verhältnis hat und welche während des Waschprozesses unwiderruflich verloren geht. Natives ACP, welches im pH-Bereich 6,6–10,6 ausgefällt wurde, variierte im molaren Ca/P-Verhältnis zwischen 1,18 und 1,50 und in HPO 4 2− /totales P zwischen 33,0 und 10,1%. Bei pH 7,40 hatte natives ACP ein molares Ca/P-Verhältnis von 1,36±0,02 und enthielt 22,8 (±2,2)% HPO 4 2− . Die Werte beim ungewaschenen Niederschlag rühren weder von aus dem Überstand aufgenommenem Ca2+ und HPO2−, noch von außen kommendem Na+, Cl− und CO 3 2− her. Die amorphen Calciumphosphate werden als eine Klasse von Salzen erkannt, welche veränderliche chemische, aber identische glasartige physicochemische Eigenschaften haben. Nicht kristallines CaHPO4·xH2O kann auch ein ACP sein, besonders in den frühen Bildungsstadien. Bei physiologischem pH verwandelt sich ACP in kleine plattenförmige Kristalle, welche große Mengen von leicht ersetzbarem saurem Phosphat enthalten. Das Waschen dieser Oberflächenschicht erzeugte chemische Veränderungen in den resultierenden Kristallen; ungewaschene Kristalle zeigten ein Diffraktionsmuster, das nur schwach demjenigen des kristallinen Aspatites glich, aber ein schlecht aufgelöstes Infrarotspektrum, welches zwischen Apatit und Octocalciumphosphat war. Es werden strukturelle Erklärungen für alle diese Phenomena diskutiert, und revidierte amorph/kristalline Mineralzusammensetzungen von Knochen und Knorpel wurden neu berechnet.
    Notes: Abstract Unwashed samples of amorphous calcium phosphate (ACP) contain an irreplaceable labile fraction, rich in acid phosphate and low in Ca/P ratio, which is irreversibly lost during the washing process. Native ACP precipitated in the pH range 6.6–10.6 varied in Ca/P molar ratio from 1.18 to 1.50 and in HPO 4 2− /total P from 33.0% to 10.1%. At pH 7.40, native ACP had a Ca/P molar ratio of 1.36±0.02 and contained 22.8 (±2.2)% HPO 4 2− . Unwashed precipitate data could not be attributed to either trapped supernatant Ca2+ and HPO 4 2− or extraneous Na+, Cl−, and CO 3 2− . The amorphous calcium phosphates are recognized as a class of salts having variable chemical but identical glass-like, physicochemical properties. Non-crystalline CaHPO4·xH2O may also be an ACP, especially during early formative stages. At physiological pH, ACP transforms to small platy crystals containing large amounts of readily-replaceable acid phosphate. Washing this surface layer produced chemical alterations in the resultant crystals; unwashed crystals had poorly-crystalline apatitic diffraction patterns but exhibited poorly-resolved infrared spectra intermediate between apatite and octacalcium phosphate. Structural explanations for all these phenomena are discussed, and revised bone and cartilage amorphous/crystalline mineral compositions have been re-calculated.
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    Calcified tissue international 23 (1977), S. 13-17 
    ISSN: 1432-0827
    Keywords: Dental calculus ; Glycopeptide ; Chemistry
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    Topics: Biology , Medicine , Physics
    Notes: Summary A method is described for the isolation and purification of a sulphated glycopeptide from human supragingival calculus. The compound was isolated after using EDTA treatment, 2 M CaCl2 extraction, proteolytic digestion, ethanol precipitation, and finally purified by DEAE cellulose chromatography. It migrated as a single component on cellulose acetate electrophoresis, and chemical and infrared spectral analysis showed the presence of covalently attached sulphate groups. The sulphated glycopeptide was distinguished from being a sulphated glycosaminoglycan.
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  • 63
    ISSN: 1432-0827
    Keywords: Bacterial amphophile ; Purification ; Chemistry ; Resorption ; Ca influx ; Cyclic AMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The bone resorptive factor and amphipathic antigen (AcA) previously identified by us in preparations fromActinomyces viscosus have been partially purified, characterized chemically, and compared. They elute at the same location on chromatography with Ac 22. The fatty acid composition of AcA and the bone resorptive factor is the same. Some differences in carbohydrate composition are observed. TheActinomyces factor does not affect calcium influx or cyclic AMP in isolated bone cells. Therefore it is concluded that AcA stimulates resorption either by gaining entrance into bone cells or by way of a yet undetermined second messenger.
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    Calcified tissue international 8 (1971), S. 228-236 
    ISSN: 1432-0827
    Keywords: Skin ; Calcinosis ; Keratin ; Chemistry ; X-ray diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des études histologiques antérieures ont montré que le follicle pileux est particulièrement susceptible de se calcifier, lorsque la peau de rats hypercalcémiques est lésée. Des analyses chimiques et par diffraction aux rayons X du follicule ont confirmé ce résultat. — En se basant sur l'augmentation du calcium et du phosphore, les calcifications débutent dans le tissue folliculaire 6–12 h après une blessure d'intensité moyenne de la peau de rats, ayant reçu du dihydrotachysterol (DHT), et 24–48 h après une blessure similaire chez des rats non injectés. Les diagrammes de diffraction aux rayons X sont diffus. Trois heures après la blessure, on note une augmentation du calcium du tissu folliculaire qui ne semble pas en rapport avec le DHT qui traduit probablement une liaison de calcium plutôt qu'un dépot minéral.
    Abstract: Zusammenfassung Frühere histologische Untersuchungen haben gezeigt, daß der Haarfollikel besonders anfällig für Verkalkungen ist, wenn die Haut von hypercalcämischen Ratten verletzt wird. Dieses Resultat wurde nun durch direkte chemische Bestimmungen und Röntgendiffraktions-analysen von Follikelgewebe bestätigt. Aufgrund der erhöhten Calcium- und Phosphatwerte kann gesagt werden, daß nach einer leichten Quetschung der Haut von Ratten, die mit Dihydrotachysterol (DHT) behandelt wurden, im Haarfollikelgewebe nach 6–12 Std Mineral-ablagerungen stattfanden, wogegen Kontrollratten mit der gleichen leichten Hautverletzung diese Ablagerungen erst nach 24–48 Std zeigten. Röntgendiffraktionsanalysen ergaben ein diffuses Apatit-Muster. Innerhalb 3 Std nach der Verletzung wurde ein Anstieg des Calcium-gehaltes im Follikelgewebe beobachtet, der nicht im Zusammenhang mit der DHT-Behandlung stand, also nicht eine Mineralablagerung, sondern eher eine Bindung von Calcium widerspiegelte.
    Notes: Abstract Previous histological investigations have shown that the hair follicle is particularly susceptible to mineralization when the skin of hypercalcaemic rats is injured. Direct chemical and X-ray diffraction analyses of follicle tissue have now confirmed this finding. As judged by increases in both calcium and phosphorus, mineral deposits began to form in hair follicle tissue 6–12 h after a mild crush injury to the skin of rats dosed with dihydrotachysterol (DHT), and 24–48 h after a similar injury to the skin of non-dosed rats. X-ray diffraction gave a diffuse apatite pattern. Within 3 h of injury there was a rise in the calcium content of follicle tissue which was not related to DHT-dosing and which was probably a reflection of calcium binding rather than mineral deposition.
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    Calcified tissue international 8 (1971), S. 304-319 
    ISSN: 1432-0827
    Keywords: Chemistry ; Calcium ; Phosphate ; Solubility ; Computer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Un programme d'ordinateur a été mis au point pour calculer les activités ioniques du calcium et l'orthophosphate dans un grand nombre de solutions. Dans le cas de solutions synthétiques, les calculs sont vérifiés en comparant les valeurs de pH, obtenues par ordinateur, avec celles observées expérimentalement. Des essais de ce type, avec des solutions possèdant des concentrations de calcium et d'orthophosphate trouvées dans les liquides biologiques et à des valeurs de pH variant de 3.00 à 10.00, indiquent que le programme est adapté pour des applications biologiques. Le programme n'est pas effectif pour des solutions, dans les lesquelles l'ion bromure est la source principale de la force ionique, sans doute, par manque d'équation étendue de Debye-Hückel dans ces circonstances. Aucune formation de complexe de phosphate de sodium n'a été notée à des concentrations biologiques normales.
    Abstract: Zusammenfassung Es wurde ein Computer-Programm ausgearbeitet, um die Ionenaktivitäten von Calcium und Orthophosphat in einer breiten Varietät von Lösungen zu berechnen. Die Berechnungen wurden bei synthetischen Lösungen durch Vergleiche zwischen den auf diese Weise errechneten pH-Werten und den experimentell gefundenen kontrolliert. Diese Art Kontrollen mit Calcium-und Orthophosphatkonzentrationen, wie sie in biologischen Flüssigkeiten gefunden werden, und mit pH-Werten zwischen 3,0 und 10,0 wies darauf hin, daß das Programm für biologische Anwendungen geeignet war. Das Programm konnte nicht benützt werden für solche Lösungen, bei welchen hauptsächlich das Bromidion zur Einstellung der Ionenstärke verwendet wurde, vermutlich weil die erweiterte Debye-Hückel-Gleichung unter diesen Umständen nicht anwendbar ist. Die Bildung eines Natriumphosphat-Komplexes unter normalen biologischen Konzentrationen konnte nicht nachgewiesen werden.
    Notes: Abstract A computer program has been designed to calculate the ionic activities of calcium and orthophosphate in a wide variety of solutions. In the case of synthetic solutions the calculations were checked by comparing the computed pH values with those observed experimentally. Tests of this type with solutions having the concentrations of calcium and orthophosphate found in biological fluids and with pH values ranging from pH 3.0–10.0 indicated that the program was suitable for biological applications. The program was not effective for solutions in which the bromide ion was a principal source of ionic strength probably because of the failure of the extended Debye-Hückel equation under those circumstances. No evidence for the formation of any sodium phosphate complex at normal biological concentrations could be found.
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    Archives of microbiology 142 (1985), S. 389-392 
    ISSN: 1432-072X
    Keywords: Ethanol tolerance ; Cytoplasmic inheritance ; Mitochondria ; Growth rate ; Fermentation rate ; Ethanol inhibition constant ; Aerobiosis ; Anaerobiosis ; S. cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The presence of active mitochondria and oxidative metabolism is shown to be essential to maintain low inhibition levels by ethanol of the growth rate (μ), fermentation rate (v) or respiration rate (ϱ) of Saccharomyces cerevisiae wild type strain S288C. Cells which have respiratory metabolism show K i (ethanol inhibition constant) values for μ, v and ϱ, higher (K i〉1 M) than those of “petite” mutants or “grande” strains grown in anaerobiosis (K i=0.7 M). In addition, the relationship between μ or v and ethanol concentration is linear in cells with respiratory metabolism and exponential in cells lacking respiration. When functional mitochondria are transferred to “petite” mutants, the resulting strain shows K i values similar to those of the “grande” strain and the inhibition of μ and v by increasing ethanol concentrations becomes linear.
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    Archives of microbiology 157 (1991), S. 66-69 
    ISSN: 1432-072X
    Keywords: Geosmin ; Anabaena ; Nitrogen source ; Growth rate ; Earth odor ; Heterocyst
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    Topics: Biology
    Notes: Abstract The addition of the proper amount of ammonium to the culture medium containing nitrate as nitrogen source enhanced the growth rate of Anabaena viguieri. The amount of geosmin produced by these cells varied with the concentrations of ammonium added. A negative correlation between the amount of geosmin produced and of the growth rate of cells was revealed. This was also found in cells grown on various forms of nitrogen sources. Without supply of any nitrogen compound, this organism is capable of fixing gaseous nitrogen, and under these conditions the cells grew relatively slowly. However, they produced more geosmin (per unit protein mass) than cells grown in the presence of combined nitrogen. The isolation of heterocysts, in which nitrogen was fixed, showed that these cells produced higher amounts of geosmin than vegetative cells. The possible relation of nitrogen assimilation to the production of geosmin in the cells was discussed.
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  • 68
    ISSN: 1432-1009
    Keywords: Pesticides ; Beliefs ; Knowledge ; Guatemala ; Health ; Farmers ; Housewives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Throughout Central America, the United States Agency for International Development (USAID), and the Zamorano Pan-American Agricultural School support a Safe Pesticide Use program. In 1993, a study of results was carried out among farmers and housewives in eastern Guatemala. Aspects of the methodology included: (1) participation of extension workers in all aspects of the study; (2) small, region-focused samples (eight cells, 30 interviews per cell); (3) comparison to control groups of untrained farmers and housewives; (4) a traditional questionnaire for studying acquisition of specific knowledge; and (5) a flexible instrument for building a cognitive map of knowledge and beliefs regarding pesticides. The cognitive map is a step toward applying modern psychocultural scaling, an approach already well developed for medicine and public health, to environmental problems. Positive results detected include progress at learning the meaning of colors on containers that denote toxicity and where to store pesticides. Pesticide application problems detected were mention by farmers of highly toxic, restricted pesticides as appropriate for most pest problems and of insecticides as the correct solution to fungus problems, and the widespread belief that correct pesticide dosage depends on number of pests seen rather than on land or foliage surface. Health-related problems detected were admission by a vast majority of housewives that they apply highly toxic pesticides to combat children's head-lice; low awareness that pesticides cause health problems more serious than nausea, dizziness, and headaches; and a common belief that lemonade and coffee are effective medicines for pesticide poisoning.
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  • 69
    ISSN: 1432-0975
    Keywords: Key words Otolith ; Chemistry ; ICP-MS ; Stock discrimination ; Epinephelus striatus
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    Topics: Biology , Geosciences
    Notes: Abstract  We examined the utility of otolith minor and trace element chemistry, assayed with inductively coupled plasma mass spectrometry (ICP-MS), as a means of delineating population structure in the Nassau grouper (Epinephelus striatus). We characterized the elemental composition of otoliths collected in 1993 from three locations in Exuma Sound, Bahamas and from Glover Reef, Belize in 1995. A single location in Exuma Sound was sampled in 1994 to test temporal variability in otolith composition. Five elements (Ca, Zn, Sr, Ba and Pb) were routinely detected, at levels significantly above background, by solution-based ICP-MS. Results from analysis of variance of elemental data, expressed as a ratio to Ca, indicated that there were no significant differences among the Exuma locations for any element, but significant variability was found between Glover Reef and the pooled Exuma localities for Zn/Ca, Sr/Ca and Ba/Ca ratios. Significant inter-annual differences at one Exuma Sound location was restricted to Ba/Ca ratios. Discriminant function analysis correctly classified 86% and 95% of the Belize and pooled Exuma sites, respectively. Otoliths from Belize were characterized by low Zn/Ca and high Ba/Ca and Pb/Ca ratios compared to otoliths from fish collected in Exuma Sound. Although differences in Ba levels may be related to upwelling at Glover Reef, more data are needed to definitely link otolith composition with regional differences in water chemistry.
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    Archives of microbiology 107 (1976), S. 41-47 
    ISSN: 1432-072X
    Keywords: Escherichia coli B ; Continuous culture ; “Phauxostat” ; Growth rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A method for the continuous culture of microorganisms is described which employs growth-dependent pH changes to control the rate of addition of fresh medium to a culture vessel. The apparatus (the “phauxostat”) supports, at constant pH, longterm continuous culture at rates near or at the maximum of which the organisms are capable. The buffering capacity of the inflowing medium determines the steady-state population density of the culture, but the rate of growth is independent of the buffering capacity. The fundamental theory of operation is tested and some basic parameters of growth are estimated using Escherichia coli B growing continuously in media containing glucose, glycerol or DL-lactate.
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    Biology and fertility of soils 17 (1994), S. 147-153 
    ISSN: 1432-0789
    Keywords: [14C]-Leucine ; [3H]-Thymidine ; Soil bacteria ; Growth rate ; Homogenization centrifugation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The incorporation of [14C]-leucine into protein by soil organisms was measured both in soil slurries and for bacteria extracted from soil by homogenization-centrifugation. The result was compared with thymidine incorporation. Using a soil slurry, 9.1×10-10 mol leucine h-1g-1 dry weight of soil was incorporated into protein, with a calculated leucine: thymidine ratio (mol:mol) of about 34. Non-specific labelling of macromolecules other than protein was observed with both the soil slurry and the homogenization-centrifugation method. With the latter, 46.5% of the total incorporation was found in the protein fraction (hot-acid insoluble). The incorporation of leucine was linear with time for at least 4 h for extracted bacteria. Even at 2000 nM, [14C]-leucine did not saturate incorporation into protein. Isotope dilution plots indicated that with 750 nM leucine, the degree of participation of the labelled substance in protein synthesis was 0.59. With this value, the ratio of leucine:thymidine incorporation into total macromolecules was calculated as 41 for extracted bacteria. On the basis of incorporation into protein (leucine) and incorporation into DNA (thymidine) only, the leucine:thymidine ratio was calculated as 117. The mean turnover time of bacteria at 22°C, calculated using conversion factors from published studies and leucine incorporation into protein of extracted bacteria, was 4.3 days.
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    Biology and fertility of soils 20 (1995), S. 53-56 
    ISSN: 1432-0789
    Keywords: Eisenia fetida breeding ; Selection ; Growth rate ; Maturation ; Reproduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Selective breeding of invertebrates has been suggested by many but studied by few. The possibilities of improving characters like biomass, maturation time, coccoon production rate, and hatching success of cocoons for the earthworm Eisenia fetida were examined in the present study. The results showed that biomass, maturation time, and number of hatchlings could be successfully improved by selective breeding, although a concomitant tendency to a lower reproductive rate, as found in vertebrates, was observed. Other characters like cocoon production rate, hatching success, and number of hatchlings per cocoon also showed promising results.
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    International journal of biometeorology 33 (1989), S. 145-150 
    ISSN: 1432-1254
    Keywords: Far-infrared radiation ; Growth ; Health ; Skin blood flow ; Sleep
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract Contrary to previous presumption, accumulated evidence indicates that far-infrared rays are biologically active. A small ceramic disk that emist far-infrared rays (4–16 μm) has commonly been applied to a local spot or a whole part of the body for exposure. Pioneering attempts to experimentally analyze an effect of acute and chronic radiation of far-infrared rays on living organisms have detected a growth-promoting effect in growing rats, a sleep-modulatory effect in freely behaving rats and an insomiac patient, and a blood circulation-enhancing effect in human skin. Question-paires to 542 users of far-infrared radiator disks embedded in bedelothes revealed that the majority of the users subjectively evaluated an improvement of their health. These effects on living organisms appear to be non-specifically triggered by an exposure to far-infrared rays, which eventually induce an increase in temperature of the body tissues or, more basically, an elevated motility of body fluids due to decrease in size of water clusters.
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    International journal of biometeorology 37 (1993), S. 113-124 
    ISSN: 1432-1254
    Keywords: History ; Climate ; Health ; Tourism ; Hippocratic corpus philosophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract This paper creates a framework for the study of the history of tourism for climate and health. It traces the ways in which people have both moved away from detrimental health conditions and towards places thought to provide climatic cures. It brings to light the complex issues that have affected the course of the tourist trade. In this way it helps to explain that the modern geographical distribution of the highly fashionable resort areas of the world owe a great deal to past and present interpretations of the HippocraticCorpus.
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    Archives of microbiology 111 (1976), S. 51-58 
    ISSN: 1432-072X
    Keywords: Macromolecule synthesis ; Cell division ; Morphogenesis ; Growth rate ; Continuous culture ; Thymine Starvation ; Mitomycin C ; Arthrobacter crystallopoietes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The sphere-rod-sphere morphology cycle of Arthrobacter crystallopoietes was accompanied by changes in the rate of growth and the rates of DNA, RNA and protein synthesis. The patterns of macromolecule synthesis resembled those found in other bacteria during a step-up followed by a step-down in growth rate. During the step-up in growth spherical cells grew into rods and macromolecules were synthesized in the absence of cell division. During stepdown, successive rounds of septation produced progressively smaller cells which did not separate and remained in chains. The morphology of the cells was dependent on the growth rate and could be altered by changing the dilution rate in a malate-limited chemostat. Gradual transitions in morphology and gradual increases in macromolecule content of the cells occurred as the growth rate was increased in the chemostat. Sphere to rod morphogenesis occurred when DNA synthesis was inhibited by treatment with mitomycin C or by thymine starvation. The DNA-deficient rods did not divide and eventually lysed. DNA, RNA and protein synthesis were continuously required for the reductive division of rods to spheres.
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    Archives of microbiology 119 (1978), S. 323-325 
    ISSN: 1432-072X
    Keywords: Halobacterium ; Chemostat ; Energetics ; Bacteriorhodopsin ; Oxygen ; Growth rate ; Membrane ; Regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The independent effects of oxygen tension and growth rate on bacteriorhodopsin synthesis in Halobacterium halobium have been studied in chemostat cultures. Bacteriorhodopsin synthesis occurs only at low growth rates and is stimulated by low oxygen tension. Fast growth rates override the stimulatory effects of oxygen tension, with the result that bacteriorhodopsin can scarcely be detected. Illumination of cultures maintained at low growth rate and low oxygen tension significantly increases the steady state cell yield. This finding suggests that under these conditions the purple membrane proton pump is coupled to energy transduction.
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    Archives of microbiology 131 (1982), S. 247-251 
    ISSN: 1432-072X
    Keywords: Bacillus subtilis ; Growth rate ; Guanosine triphosphate ; RNA accumulation
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    Topics: Biology
    Notes: Abstract After addition of amino acids to a Bacillus subtilis glucose culture the intracellular guanosine triphosphate (GTP) concentration increased. The growth rate and the rate of RNA accumulation increased too. With mycophenolic acid, an inhibitor of inosinate dehydrogenase, it was possible to adjust the intracellular GTP concentration to values ranging between that of the glucose culture and that of the culture which had received amino acids. This led to intermediate growth rate values. Guanosine abolished the mycophenolic acid inhibition of GTP synthesis. It also counteracted the drug effects on growth rate and RNA accumulation. In cultures growing on Nutrient Sporulation Medium, in which the growth rate decreases as cell density increases, the GTP concentration did correlate with the growth rate.
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    Archives of microbiology 130 (1981), S. 248-249 
    ISSN: 1432-072X
    Keywords: Growth rate ; Phospholipids ; Fatty acids ; Ethanol ; Microsporum gypseum ; Microsporum cookie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ethanol supplementation to the growth medium of Microsporum gypseum and Microsporum cookie resulted in changes in phospholipid composition and degree of unsaturation of their fatty acids without affecting the growth rate of the organism. Phosphatidylethanolamine increased with a simultaneous decrease in phosphatidylserine. Unsaturated fatty acids of total phospholipids decreased significantly which was primarily due to the decreased levels of linoleic acid.
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    Archives of microbiology 131 (1982), S. 36-42 
    ISSN: 1432-072X
    Keywords: Escherichia coli ; Growth rate ; Low nutrient concentration ; Precision measurement ; Diffusion-limited growth ; Theoretical maximum growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Using a 10cm flow-through cuvette in a high precision spectrophotometer linked to a mini-computer, the growth rate dependence of Escherichia coli on glucose concentration has been studied. The specific growth rate vs bacterial mass of single cultures consuming small amounts of glucose was followed. The data were analyzed with the computer programs described previously. For neither batch nor chemostat-cultured organisms did growth follow the monod growth law. Rather, the growth rate vs residual glucose concentration has an almost abrupt change in slope, indicative of a passive diffusion barrier prior to an uptake system possessing hyperbolic dependency. Calculations showed that the diffusion through the outer membrane via the porin channels could quantitatively account for the deviations from hyperbolic dependency. Long term chemostat culture alters the bacteria so that the maximum specific growth rate is reduced, but the initial dependence on glucose concentration is increased approaching more closely the theoretical limit. Therefore there was both a change in the outer membrane channels and the uptake activity of the cytoplasmic membrane.
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    Archives of microbiology 142 (1985), S. 81-86 
    ISSN: 1432-072X
    Keywords: Carbon-fixation ; Cell volume ; Dinophyceae ; Growth rate ; Irradiance ; Macromolecular composition ; Nucleic acid composition ; Amphidinium carteri
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of irradiance on the growth rate, macromolecular composition and photosynthetic carbon metabolism of Amphidinium carteri was studied in batch culture. Growth rate increased linearly with increasing irradiance up to a maximum growth rate of 0.04 h-1 at an irradiance of 80 μEm-2s-1. In contrast to a number of other studies on both prokaryotic and eukaryotic microorganisms, ours showed that cellular content of RNA, DNA, protein and carbohydrate of A. carteri were invariant with growth rate over the range μ=0.04 to 0.007 h-1. The invariant macromolecular composition was correlated with a constant modal cell volume. Chlorophyll and lipid per cell increased with decreasing irradiance. The distribution of [14C]-bicarbonate in the major end products of photosynthesis after incubation with isotope for 14% of a doubling time showed that the percentage carbon in the chloroform (lipids and pigments) fraction increased with decreasing irradiance while that of the trichloroacetic acid soluble (carbohydrate) fractions decreased. The percentage of isotope in the trichloroacetic acid insoluble (protein) fraction and methanol: water fraction (metabolites) remained constant. Because this species, under light-limited growth, differs from other organisms so far studied, more species must be similarly examined before nucleic acid content is used as an index growth rate in the field.
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    Archives of microbiology 143 (1985), S. 143-146 
    ISSN: 1432-072X
    Keywords: Exoglucanase ; Saccharomyces cerevisiae ; Continuous culture ; Growth rate
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    Topics: Biology
    Notes: Abstract The rate of synthesis and secretion of exo-1–3-β-glucanase activity closely paralleled the specific rate of growth in exponentially growing Saccharomyces cerevisiae cells in batch culture. When the stationary phase was reached both synthesis and secretion stopped. No activity was synthesized when the cells were maintained in carbon sources that did not allow them to grow. Studies in continuous culture indicate a strong relationship between the synthesis of exoglucanase activity and the specific growth rate. These results are taken as evidence of an essential role of this activity during the yeast budding cycle.
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    Accreditation and quality assurance 5 (2000), S. 409-413 
    ISSN: 1432-0517
    Keywords: Key words Metrology ; Comparisons ; Chemistry ; Standards
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract  After stressing the importance in the modern world of accurate and reproducible measurements, the actions taken by the Bureau International des Poids et Mesures to set up, together with the regional metrology organizations, a series of key comparisons are described. They are the technical foundation of a mutual recognition of national measurement standards arrangement prepared in conjunction with the National Metrology Institutes (NMIs). This arrangement also includes the recognition of calibration and measurement certificates issued by these institutes. Then, the consequences of this arrangement for trade are described. The case of chemical analysis is illustrated by the application of the Kyoto protocol on the reduction of greenhouse gases. But the global workload to be taken up by the International Committee of Weights and Measures, its Consultative Committee for Amount of Substance and the NMIs is huge.
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    Aquatic sciences 51 (1989), S. 108-128 
    ISSN: 1420-9055
    Keywords: Chemistry ; mountain lakes ; silica ; acidity ; sediment
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    Topics: Biology
    Notes: Abstract Alpine lakes in siliceous catchments of Tyrol and Carinthia (Austria) show signs of acidification. About 9% of the studied lakes have no alkalinity, more than 20% are below pH 6. About two thirds of all lakes have acid neutralizing capacities below 100 μeq 1−1. In spite of moderate precipitation acidity, some lakes show considerable concentrations of dissolved reactive aluminum during or shortly after snowmelt. High altitude lakes of the Alps are definitely more acidic than high mountain lakes in remote areas. Large differences in water and soil chemistry of nearby situated lakes were attributed to heterogeneities of bedrock geology. Paleolimnological investigations on former pH values of five lakes, based on diatom assemblages in the sediment, showed different developments: recent and past acidification, stable conditions, and alkalinization.
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    Theoretical and applied genetics 63 (1982), S. 145-150 
    ISSN: 1432-2242
    Keywords: Mice ; Selection ; Growth rate ; ad libitum feeding ; Restricted feeding
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    Topics: Biology
    Notes: Summary Selection for post-weaning weight gain in mice from 21 to 42 days, on either a full or restricted feeding level during this period was carried out for seven generations. Control lines were maintained for each feeding level. The rate of selection response was higher on full feeding due to a higher heritability and a larger phenotypic variance. Realised heritabilities of 0.29±0.05 and 0.19±0.04 for selection on full and restricted feeding respectively, were in close agreement with base population estimates. Selection on full feeding led to positive correlated responses in 21 day weight, 42 day weight, food intake and efficiency between 21 and 42 days, and 42 day tail length, but with little change in reproductive performance. Correlated responses to selection on restricted feeding were reduced 21 day weight, but an increase in 42 day weight and increased efficiency from 21 to 42 days. However, overall reproductive performance fell.
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  • 85
    ISSN: 1432-2242
    Keywords: Oats ; Selection ; Growth rate ; Biological yield ; Independent culling ; Harvest index
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    Topics: Biology
    Notes: Summary Grain yield was selected in Avena sativa X A. sterilis populations of segregates by applying independent culling for harvest index and either vegetative growth index or unit straw weight. Samples of lines intensively selected for harvest index had high harvest index but low grain yield because they had low vigor. Populations intensively selected for growth rate index or unit straw weight had high biological yield but low harvest index. Intensive selection for grain yield per se resulted in samples with high grain yield, but they were late and tall. Samples selected for harvest index at a 25% selection intensity first and subsequently selected for vegetative growth index or unit straw weight had grain yield as high as the samples selected for grain yield per se and vegetative growth index, and they had acceptable heading date and plant height. Backcrosses three and four were best, among the various BC generations, for selecting oat lines with high grain yield and suitable agronomic traits. CI 7463 was superior to CI 8044 as a recurrent parent, and B 445 was inferior to other A. sterilis accessions as a donor parent.
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    Planta 201 (1997), S. 441-445 
    ISSN: 1432-2048
    Keywords: Key words: Brassica (temperature stress) ; Growth rate ; Lycopersicon (temperature stress) ; Respiration ; Temperature coefficient ; Temperature stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract.  The temperature dependence of metabolic rates determines how plant growth rates vary with temperature. This paper shows that equations on physiological relations between respiration rates (i.e. rates of heat loss and CO2 evolution) and growth rates can be used to describe temperature effects on plant growth rate. Incorporating measured values of plant respiratory heat and CO2 rates at a few temperatures into the equations allows description of growth rates as a function of temperature and provides a physiological basis for understanding the effects of temperature on growth rate. The paper presents data on cabbage (Brassica oleracea L. Capitata) and tomato (Lycopersicon esculentum Miller cv. Ace) as model cool-climate and warm-climate cultivars to illustrate application of the methods in determining optimal growth climates for different cultivars, accessions, and ecotypes. The respiration-based calculations of growth rate vs. temperature yield curves for both species that are consistent with known temperature-growth requirements. We conclude that plant responses to temperature can be accurately predicted in detail from respiration rate measurements and the growth-respiration model. These studies demonstrate that the temperature dependence of growth rates is a function of the temperature dependencies of both metabolic rates and metabolic efficiency, which change continuously with temperature. The ultimate cause of high- and low-temperature growth limits is commonly not membrane phase transitions or enzyme denaturation as has been supposed, but is loss of substrate carbon conversion efficiency. The results show that “plant temperature stress” has been misunderstood and must be redefined because there is no “nonstressfull temperature”.
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    Astrophysics and space science 224 (1995), S. 81-84 
    ISSN: 1572-946X
    Keywords: Chemistry ; Depletions ; Shocks ; IRAS 05338-0624 ; NGC 1333 IRAS 4
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    Topics: Physics
    Notes: Abstract High resolution interferometer and single-dish observations of young, deeply embedded stellar systems reveal a complex chemistry in the circumstellar environments of low to intermediate mass stars. Depletions of gas-phase molecules, grain mantle evaporation, and shock interactions actively drive chemical processes in different regions around young stars. We present results for two systems, IRAS 05338-0624 and NGC 1333 IRAS 4, to illustrate the behavior found and to examine the physical processes at work.
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    Astrophysics and space science 216 (1994), S. 153-154 
    ISSN: 1572-946X
    Keywords: Chemistry ; Molecular Hydrogen ; Cloud Models
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    Topics: Physics
    Notes: Abstract Observations of the CO J=1-0 line are commonly used as a tracer for molecular material in clouds. The ratio of the H2 column density to the integrated intensity of this line,X, is often taken to be constant, despite theoretical and observational uncertainty. We have tried to identify how this ratio depends on cloud parameters, testing a simple theoretical argument suggesting its invariance with respect to density. The apparent constancy can be understood if clouds are clumpy on scales of Av ≈ 1-2 mag.
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    Astrophysics and space science 233 (1995), S. 125-137 
    ISSN: 1572-946X
    Keywords: Interstellar Medium ; Dark Clouds ; Chemistry ; Bistability ; C-shock Waves
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    Topics: Physics
    Notes: Abstract Shock waves perturb the chemical state of the interstellar gas. We consider the effects of C-shocks on the composition of molecular clouds, for a range of values of the pre-shock gas density and magnetic induction. The time required to re-establish equilibrium in the post-shock gas depends on the initial conditions and can become very large. The significance of the two known chemical phases of dark clouds and of bistability is considered in this context.
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    Astrophysics and space science 233 (1995), S. 161-164 
    ISSN: 1572-946X
    Keywords: Stars ; Chemistry ; Diffusion
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    Topics: Physics
    Notes: Abstract We have assessed the role of diffusion in determining chemical abundances in molecular interface regions. Chemical models have been developed which include the appropriate diffusion terms and that are appropriate to a narrow diffusion region (∼0.01pc) that may exist at the interface between a dark core and a hot, shocked T-Tauri wind. We have assumed pressure balance throughout and have calculated the chemical abundances as functions of time and position through the interface. The results show that significant enhancements of detectable molecules/transitions are expected (e.g. CO J=6→5, OH and CH). Using a realistic value of the diffusion coefficient a diffusive region of dimension 0.01pc may be established within about 104 years. In general it seems likely that diffusion processes are highly significant on these and smaller lengthscales.
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    Plant foods for human nutrition 44 (1993), S. 195-211 
    ISSN: 1573-9104
    Keywords: Legumes ; Pulses ; Nutrition ; Health ; Culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Starchy legumes have been consumed by humans since the earliest practice of agriculture and have been ascribed medicinal and cultural as well as nutritional roles. They are an important component of the diet in the developing countries in Africa, Latin America, and Asia where they are especially valuable as a source of dietary protein to complement cereals, starchy roots and tubers. Legumes contain 20–30% protein which is generally rich in lysine and limiting in sulfur amino acids. The nutritional quality of legume protein is limited by the presence of both heat labile and heat stable antinutrients as well as an inherent resistance to digestion of the major globulins. In addition to its nutritional impact, legume protein has been shown to reduce plasma low density lipoprotein when consumed. Legume starch is more slowly digested than starch from cereals and tubers and produces less abrupt changes in plasma glucose and insulin upon ingestion. Starchy legumes are also valuable sources of dietary fiber as well as thiamin and riboflavin. Starchy legumes are a valuable component of a prudent diet, but their consumption is constrained by low yields, the lack of convenient food applications, and flatulence.
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    Biology and fertility of soils 9 (1990), S. 101-109 
    ISSN: 1432-0789
    Keywords: Phryganella acropodia ; Testate amoeba ; Growth rate ; Rhizopoda ; Feeding ; Fungal species ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Clones of Phryganella acropodia were cultivated under different trophic conditions with bacteria as the food source. The doubling time was estimated to be 3 days. The edibility of four species of fungi, Aspergillus niger, Cunninghamella echinulata, Penicillium echinulatum and Stilbella bulbicola, was tested, but only Penicillium enchinulatum and Stilbella bulbicola were eaten and digested by the amoeba. An ultrastructure examination showed that there are two contractile vacuoles, many dictyosomes, a single nucleus with several nucleoli, and peroxisomes. The pseudopodia are filiform when attached to the substrate but change to lobose when the animal is floating. A thin organic membrane covers the aperture of resting forms.
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    Biology and fertility of soils 7 (1989), S. 198-201 
    ISSN: 1432-0789
    Keywords: Plate technique ; Colony formation ; Growth rate ; Bacterial grouping ; Oligotrophic bacteria ; Copiotrophic bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The colony formation of soil bacteria was studied in relation to incubation time. The process was simulated by a colony-forming curve (CFC) which was a superposition of several component curves (cCFC) given theoretically by the first-order reaction (FOR) model. This model had been previously proposed to define the colony formation of cells of a single culture. Soil bacteria were divided into several groups by these cCFC, as different types of bacteria produced their own colonies. Bacteria belonging to a single group grew at a similar rate on the plating medium and each group was characterized by a different growth rate. Most copiotrophic bacteria were fast growers and most oligotrophic bacteria slow growers.
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  • 94
    ISSN: 1440-1703
    Keywords: Growth rate ; Mortality ; Net production ; Pipe model theory ; Secondary ; succession
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Growth and death rates of aboveground plant parts were measured in a mature forest and four different-aged deciduous broadleaf forests regeneratede after clear-cutting, with special reference to rates for woody parts (stems and branches) of different diameters (ø) in rerms of the pipe model theory (Shinozaki et al., 1964). The total biomass increment of woody parts of trees higher than 1.3 m varied within a range of 2.1-4.6 ton ha−1 yr−1, the increase beingdue largely to the growth of canopy trees exposed to direct sunlight. Biomass increments of small (ø〈1 cm) and medium (1≤ø〈5 cm) woody parts were negligibly small except in the youngest forest, and changes in aboveground woody biomass with forest age after clear-cutting mainly resulted from accumulation of large (5 cm〈ø) woody parts of canopy trees. Biomass loss of trees due to death and grazing increased with forest age from 4.0 to 8.3 ton ha−1 yr−1. Recovery of leaf and small wood falls was observed at the early stage of regeneration, while large wood falls increased during regeneration. Flower and fruit fall was markedly higher in the mature forest than in the other four forest types. Mortality of woody parts became higher with forest age and was 20, 5.0 and 0.46% yr−1 for small, medium and large parts, respectively, at the mature stage. Aboveground net production of the forest was in therange 7.6-13.3 ton ha−1 yr−1 with the undergrowth vegetation lower than 1.3 m being 0.4-1.4 ton ha−1 yr−1. Production recovered rapidly at an early stage of regeneration and was highest in mature forest.
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    Journal of industrial microbiology and biotechnology 11 (1993), S. 157-161 
    ISSN: 1476-5535
    Keywords: Kluyveromyces ; Growth rate ; Temperature ; Water activity ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The effects of various physicochemical parameters on the growth of twoKluyveromyces marxianus strains were investigated, including: pH values, sodium chloride, water activity in the medium and temperature. Both yeast strains were unaffected by pH changes. Optimal pH for growth was found to be 4 with both strains, but they were able to develop within the pH 3–8 range. Suitable growth was obtained at temperatures of 4–44°C and the optimal temperature for growth was 36°C for both strains. Modelling of this latter parameter is described. Growth of both microorganisms was considerably modified by increased NaCl or decreased water activity in the medium.
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    Journal of industrial microbiology and biotechnology 12 (1993), S. 190-194 
    ISSN: 1476-5535
    Keywords: Predictive microbiology ; Growth rate ; Lag time ; Differential equation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The main steps of modeling bacterial growth responses are summarized and a new model for growth curves is shown. Its advantages are analyzed from some theoretical and practical points of view. The new model fits better and has more advantageous statistical properties than the Gompertz curve.
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    Plant and soil 85 (1985), S. 163-183 
    ISSN: 1573-5036
    Keywords: Growth rate ; N content ; Mineralization ; N uptake ; Assimilate partition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Quantitative relationships for key processes influencing N response were derived from measurements of inorganic N in soil, the weights and N contents of foliage and tubers made at intervals during growth of maincrop potatoes in 11 N fertilizer experiments. Apparent mineralization rates (calculated from measurements of N uptake and inorganic N in the top metre and averaged over the growth period) were remarkably similar from site to site despite wide differences in the textures, water contents and organic matter contents of the soils. They were mostly about 0.78 kg N ha−1 m−1 d−1. Inorganic N in the top 50 cm of soil was rapidly removed by the crop until it fell on all sites to a low value (about 4 μg N cm−3) which was maintained for the remainder of the growth period. When N fertilizer was applied, growth rate until at least the end of July was always well defined by a single coefficient in a previously derived equation. Average values of this coefficient for each of the soil types and for each of the years in which the experiments were carried out were within 20% of each other. The minimum %N in the dry matter needed to permit maximum growth rate declined with increase in plant weight in a similar manner to that previously found for other crops. Equations were found for the partition of assimilate and of nitrogen between the foliage and tubers. The coefficients in them were little affected by whether or not N fertilizer was applied. According to these relationships the maximum potential dry weight yield of tubers is 20 t ha−1 and requires the crop to contain at least 290 kg N ha−1.
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    Plant and soil 80 (1984), S. 201-213 
    ISSN: 1573-5036
    Keywords: Dinitrogen fixation ; Growth rate ; Nitrate ; Trifolium subterraneum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Subterranean clover plants were grown as swards (about 2000 plants/m2) under controlled conditions with N provided either by N2-fixation (NO 3 − withheld) or by assimilation of NO 3 − (NO 3 − supplied). Crop growth rates were measured by dry matter sampling over periods of up to 70 days at PPFD values of 400–1000 μmole quanta/m2/s. When NO 3 − was supplied from sowing the swards grew more rapidly than when the swards were not supplied with NO 3 − and plants had to establish an N2-fixing apparatus. When inter-plant competition was reduced within the sward, a difference in growth rate in favour of NO 3 − -fed plants continued for at least 50 days. When however, a closed canopy was allowed to form, the NO 3 − -fed swards had more dry weight than the N2-fed swards at the time of canopy closure but thereafter the two swards grew at similar rates at light flux densities of above about 800 μmole quanta/m2/s. At light flux densities of about 400 μmole quanta/m2/s N2-fed swards had a growth rate 70–80% of that of NO 3 − -fed plants. NO 3 − -fed plants had a higher organic N content than did N2-fed plants under all conditions.
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    Boundary layer meteorology 85 (1997), S. 197-222 
    ISSN: 1573-1472
    Keywords: Turbulence ; Chemistry ; Closure ; Convective boundary layer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract We study the interactions of chemistry and turbulent mixing of tracersin the convective boundary layer with a second-order closure model,including higher order chemistry terms. In order to limit the number of predictive equations we prescribe the profiles for ¯w¯Θ, ¯w¯θ ¯θ and the lengthscale l. However, for model validation we treat temperature and humidity asinert tracers, and compare the results with profiles observed during theAir Mass Transformation Experiment, and with similarity expressions for thesurface layer. We find good agreement of the mean profiles, but the (co-)variances are slightly underpredicted. Furthermore, the model usesdiagnostic equations expressing third moments of concentration in terms ofsecond moments and their vertical derivatives. They are compared withlarge-eddy model results, showing good agreement and, therefore, thesimplifications are justified. The model is applied to the transport of two gases subject to one bimolecular reaction. The importance of concentration correlations on themean transformation rate is studied. For two gases diffusing in oppositedirections we find for moderate and fast chemistry a 50% and90% decreased transformation rate due to the negatively correlatedconcentrations. These values are similar to large-eddy results of Schumannand Sykes et al. For two bottom-up tracers we find that the covariance ofboth reactive species is either positive or negative, increasing or reducingthe effective transformation rate depending on the Damköhler number (the ratio of the turbulent and the chemistry timescale). A significantdirect influence of chemistry on the flux divergence is found in bothcases. According to the model the effective transport to mid-levels of theboundary layer is increased when two reactive tracers diffuse in oppositedirections, and decreased in the case of two bottom-up tracers.
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    Earth, moon and planets 88 (2000), S. 35-58 
    ISSN: 1573-0794
    Keywords: Chemistry ; interplanetary dust particles (IDPs) ; Leonids ; meteor trails ; meteoroids ; meteors ; structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The cometary Leonid meteoroids represent a size range in between largest carbon-richIDPs and the smallest CI meteorites. Their dustball structure and chemistry offer anopportunity to constrain hierarchical dust accretion inferred from petrologic studies ofaggregate and cluster IDPs. The Leonid shower meteoroids of known ``comet ejection''ages provide an opportunity to study space weathering of cometary dust over periodsof up to several hundred years. The meteors and aggregate and cluster IDPs displaycontinuous thermal modification of organics and volatile element (Na, K-bearing phases), that occur as discrete minerals and amorphous solids each different response during kinetically controlled ablation. Leonid meteoroids are not excessively Na-rich. The occurrences of Leonid meteors can now be accurate predicted and combined withknowledge better models for the settling rates, collections of surviving dust becomea comet nucleus-sampling mission.
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