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  • 1
    Electronic Resource
    Electronic Resource
    Water relations and desiccation-avoiding behavior in the vinegaroon Mastigoproctus giganteus (Arachnida: Uropygi) (1971)
    Springer
    Entomologia experimentalis et applicata 14 (1971), S. 99-106 
    Details
    ISSN: 1570-7458
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Mastigoproctus giganteus se rencontre dans les régions arides du Sud-Ouest des U.S.A.; rare pendant la saison sèche, il appraît après les pluies. C'est un prédateur nocturne. principalement d'insectes. Le présent travail tente de préciser comment cet Arachnide réagit aux conditions d'aridité des régions désertiques. De grands exemplaires vivants de M. giganteus montrent un taux de perte en eau relativement élevé pour une température de 26° avec une humidité relative pouvant aller jusqu'à 95%. Pour ces grands spécimens la transpiration à travers la cuticule s'accroît de façon approximativement linéaire pour les températures supérieures, ce qui indique l'absence probable d'une couche cireuse épicuticulaire fonctionnelle. Des animaux hydratés ne répondent pas à un gradient d'humidité, mais après avoir été soumis à des conditions de dessication les individus de petite taille montrent une préférence marquée pour l'air le plus humide. Ils ne manifestent aucune préférence entre la lumière (1,500 lux) ou l'obscurité lorsqu'ils sont placés sur sable sec ou humide, même après avoir une dessication partielle. La faible aptitude physiologique de ces animaux pour réduire leurs pertes en eau semble compensée par un sens thigmotactique hautement développé qui leur permet d'une part, de capturer aisément leurs proies, d'autre part de détecter des surfaces non-horizontales contre lesquelles ils creusent alors si le substrat est humide. Ce comportement doit jouer un rôle important en évitant à l'animal les conditions de dessication.
    Notes: Abstract The vinegaroon or whip scorpion Mastigoproctus giganteus gains water by drinking from a moist substrate and from its prey. These are found by the sensitive antenniform front legs. Large specimens readily lose water to the air at 26° at humidities up to 95% R.H. As temperatures increase they lose water in proportion to the saturation deficit of the atmosphere, suggesting the absence of an epicuticular wax layer. Desiccated vinegaroons respond positively to moist air in a humidity gradient, but show no preference between darkness and light. Substrate moisture does not affect the lack of such a preference by normal animals. Burrowing is characteristic of dehydrated individuals. By using their sensitive front legs these first detect nonhorizontal surfaces and, provided the substrate is moist, dig burrows against — and in nature most likely beneath — such surfaces so that further water loss is presumably avoided.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341130
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  • 2
    Electronic Resource
    Electronic Resource
    Water and temperature relations, and diurnal rhythms of scolopendromorph centipedes (1970)
    Springer
    Entomologia experimentalis et applicata 13 (1970), S. 187-193 
    Details
    ISSN: 1570-7458
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les Myriapodes étudiés montrent une perte d'eau par évaporation lorsqu'ils sont placés dans une ambiance à 27° et dont l'humidité relative est de 98%; il n'y a aucune indication permettant de penser que ces arthropodes peuvent se rehydrater à partir des surfaces mouillées ou de l'humidité atmosphérique, par prélèvement à travers leur tégument. La perte d'eau par transpiration est directement en rapport avec la déficience de saturation de l'air et il n'y a aucune température critique de transition pour laquelle la cuticule deviendrait perméable à l'eau. Néanmoins l'eau est retenue plus efficacement par Scolopendra que par Lithobius, ce qui suggère chez le premier genre une adaptation aux milieux chauds et secs. Le point de surfusion mesuré pour de grands spécimens maintenus en insectarium, est en moyenne de -3,1±0.48° et un seul choc à cette température de surfusion peut être préjudiciable ou même fatal. Cela indique que ces arthropodes doivent éviter les froids de l'hiver en creusant plus profondément les galeries. Des expériences utilisant un actographe montrent que ces Myriapodes ont une activité nocturne. Le rythme naturel d'activité persiste à l'obscurité et à une température constante, mais il est rapidement perdu par exposition à un éclairement continu.
    Notes: Abstract Water is lost by transpiration at relative humidities (R.H.) as high as 98% at 27° C and there is no evidence of the uptake of moisture through the integument from unsaturated air or moist surfaces. Water-loss through transpiration is directly related to saturation deficiency and there is no ‘critical’ transitional temperature at which the cuticle becomes porous. Nevertheless, water is retained more efficiently in Scolopendra than it is in Lithobius, suggesting an adaptation to hot-dry environments. The mean supercooling point of large specimens conditioned in an insectary is -3.1±0.48° and a single supercooling can be injurious or fatal. This indicates that cold winter weather must be avoided by burrowing deeply. Aktograph experiments show that these centipedes are nocturnal. The rhythm persists in darkness at constant temperature, but is quickly lost in constant light.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00344460
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  • 3
    Electronic Resource
    Electronic Resource
    A Comparison of Selected Diversity, Similarity, and Biotic Indices for Detecting Changes in Benthic-Invertebrate Community Structure and Stream Quality (2000)
    Springer
    Archives of environmental contamination and toxicology 39 (2000), S. 469-479 
    Details
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract Implementation of advanced wastewater treatment at the two municipal wastewater-treatment plants for Indianapolis, Indiana, resulted in substantial improvement in the quality of the receiving stream and significant changes in the benthic-invertebrate community. Diversity, similarity, and biotic indices were compared to determine which indices best reflected changes in the composition of the biota in the river. None of the indices perfectly reflected the changes in river quality or community structure. Similarity indices, especially percentage similarity, exhibit the most promise of the three classes of indices. Diversity indices were least useful, wrongly indicating that water quality deteriorated after the upgrade of the wastewater-treatment plants. The most descriptive tool in analyzing the data was the percentage of Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa present. Using a mixture of indices and other analytical tools, such as EPT, in the analysis of biological data will ensure the most effective investigations of water quality.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002440010129
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  • 4
    Electronic Resource
    Electronic Resource
    Comparison of gas chromatography/mass spectrometry and immunoassay techniques on concentrations of atrazine in storm runoff (1996)
    Springer
    Archives of environmental contamination and toxicology 31 (1996), S. 378-385 
    Details
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract Gas chromatography/mass spectrometry (GC/MS) and enzyme-linked immunosorbent assay (ELISA) techniques were used to measure concentrations of dissolved atrazine in 149 surface-water samples. Samples were collected during May 1992–September 1993 near the mouth of the White River (Indiana) and in two small tributaries of the river. GC/MS was performed on a Hewlett-Packard 5971 A Use of brand names is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey, the Uniroyal Chemical Company, or Wichita State University. with electron impact ionization and selected ion monitoring of filtered water samples extracted by C-18 solid phase extraction; ELISA was performed with a magnetic-particle-based assay with photometric analysis. ELISA results compared reasonably well to GC/MS measurements at concentrations below the Maximum Contaminant Level for drinking water set by the U.S. Environmental Protection Agency (3.0 μg/L), but a systematic negative bias was observed at higher concentrations. When higher concentration samples were diluted into the linear range of calibration, the relation improved. A slight positive bias was seen in all of the ELISA data compared to the GC/MS results, and the bias could be partially explained by correcting the ELISA data for cross reactivity with other triazine herbicides. The highest concentrations of atrazine were found during the first major runoff event after the atrazine was applied. Concentrations decreased throughout the rest of the sampling period even though large runoff events occurred during this time, indicating that most atrazine loading to surface waters in the study area occurs within a few weeks after application.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212676
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  • 5
    Electronic Resource
    Electronic Resource
    Comparison of Gas Chromatography/Mass Spectrometry and Immunoassay Techniques on Concentrations of Atrazine in Storm Runoff (1996)
    Springer
    Archives of environmental contamination and toxicology 31 (1996), S. 378-385 
    Details
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract. Gas chromatography/mass spectrometry (GC/MS) and enzyme-linked immunosorbent assay (ELISA) techniques were used to measure concentrations of dissolved atrazine in 149 surface-water samples. Samples were collected during May 1992–September 1993 near the mouth of the White River (Indiana) and in two small tributaries of the river. GC/MS was performed on a Hewlett-Packard 5971A with electron impact ionization and selected ion monitoring of filtered water samples extracted by C-18 solid phase extraction; ELISA was performed with a magnetic-particle–based assay with photometric analysis. ELISA results compared reasonably well to GC/MS measurements at concentrations below the Maximum Contaminant Level for drinking water set by the U.S. Environmental Protection Agency (3.0 μg/L), but a systematic negative bias was observed at higher concentrations. When higher concentration samples were diluted into the linear range of calibration, the relation improved. A slight positive bias was seen in all of the ELISA data compared to the GC/MS results, and the bias could be partially explained by correcting the ELISA data for cross reactivity with other triazine herbicides. The highest concentrations of atrazine were found during the first major runoff event after the atrazine was applied. Concentrations decreased throughout the rest of the sampling period even though large runoff events occurred during this time, indicating that most atrazine loading to surface waters in the study area occurs within a few weeks after application.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002449900121
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  • 6
    Electronic Resource
    Electronic Resource
    Food, ingestion rates, and assimilation in the desert millipede Orthoporus ornatus (Girard) (Diplopoda) (1975)
    Springer
    Oecologia 20 (1975), S. 231-236 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Orthoporus ornatus feeds mostly on dead plant material and on superficia tissue of desert shrubs. Sand, small particles of rock, and parts of arthropods are also ingested. Millipedes could not be induced to feed in the absence of moist soil in the laboratory after an initial day of feeding. Field observations of apparent food preferences were made at several sites in the southwestern U.S. Millipedes at Big Bend National Park, Texas, fed regularly on bark of the following desert shrubs: cholla (Opuntia sp.), cresotebush (Larrea divaricata), and ocotillo (Fouqueria splendens). Millipedes on the West Mesa of Albuquerque, New Mexico, fed mostly on superficial tissues of dead Russian-thistle (Salsola kali). At the Jornada Validation Site, Dona Ana County, New Mexico, millipedes fed regularly on the bark of Mormon tea (two Ephedra spp.) and mesquite (Prosopis glandulosa). Otherwise, grazing on an assortment of surface litter was commonly observed. Ingestion rates and assimilation efficiencies were determined in the laboratory for millipedes feeding on Prosopis and Ephedra using an ash-free technique. Assimilation efficiencies and ingestion rates were temperature dependent, increasing with a rise in temperature. Ingestion rates for Ephedra ranged from 0.020 to 0.050 g ash-free dry wt per g dry wt tissue per day, with assimilation efficiencies ranging from 20–37%. Ingestion rates were lower for Prosopis than for Ephedra. Feeding experiments at 24° C were considered to depict feeding characteristics found in surface millipedes under field conditions. These millipedes ingested 0.034 g ash-free dry weight of Ephedra per g dry body weight per day with 31.4% of the food being assimilated. No significant differences occurred between assimilation efficiencies calculated by ash-free techniques and by using caloric values of food and feces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00347475
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  • 7
    Electronic Resource
    Electronic Resource
    Feeding-season production in the desert millipede Orthoporus ornatus (Girard) (Diplopoda) (1976)
    Springer
    Oecologia 24 (1976), S. 265-276 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Production during an assumed 131-day feeding season in 1974 was estimated for Orthoporus ornatus between 4.0 and 12.0 mm in midsegment width at Tornillo Flat, Big Bend National Park, Texas. A conservative density estimate in 1973 of 1,302 millipedes ha-1 involved daily specimen removal from three, 929-m2 plots for a month. Each plot typified a different aspect of local desert vegetation; most specimens came from the plot with greatest plant diversity and relatively high (20%) cover. Production calculations using 1973 density estimates were based on increase in size-class specific dry weight (minus gut contents) between 14 May and 21 September, 1974. Production ha-1 of cuticle and tissue was estimated at 0.85 kg (1972 kcal), while that of tissue alone came to 0.29 kg (1971 kcal). Orthoporus ornatus from Albuquerque, New Mexico increased in dry weight during 92 days in 1974 more rapidly and to a greater extent than comparable size classes at Tornillo Flat. An estimated feeding-season energy budget based on ash-free values of shrub food eaten at Tornillo Flat indicated ingestion ha-1 of 3,434 g (13,712 kcal) and defecation of 3,181 g (9,187 kcal). An independent estimate of ingestion based on known ingestion rates was 8,851 g ha-1. Considering probable net primary production at Tornillo Flat, local O. ornatus exert a trophic impact similar to that of other large invertebrate detritivores elsewhere.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00345478
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  • 8
    Electronic Resource
    Electronic Resource
    Respiratory metabolism of the desert millipede Orthoporus ornatus (Girard) (Diplopoda) (1974)
    Springer
    Oecologia 17 (1974), S. 179-186 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Respiratory metabolism was measured each month for Orthoporus ornatus throughout a year. Respiratory rates were determined at a standard 20°C and at the mean ambient soil temperature at time of collection. No significant differences were noted between respiratory rates of reproductively mature males and females. A size relationship between live body weight and oxygen consumption per unit weight was found. The b values for 20°C and 25°C were-0.28 and-0.24, respectively. Premolt specimens had lower respiratory rates than postmolt individuals. There were significant differences between Q 10 values of animals exposed to temperatures above and below ambient field conditions. Seasonal changes in the use of metabolic reserves by O. ornatus were indicated by corresponding changes in RQ values. A “best estimate” of annual respiratory metabolism was 1332 cal g-1yr-1. Respiratory metabolism closely paralleled changes in ambient field temperature and was at its peak in July when animals were on the soil surface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00346280
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  • 9
    Electronic Resource
    Electronic Resource
    Allocation of reproductive effort in Mus domesticus: responses of offspring sex ratio and quality to social density and food availability (1988)
    Springer
    Behavioral ecology and sociobiology 23 (1988), S. 357-365 
    Details
    ISSN: 1432-0762
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Female mammals in good condition can maximize their inclusive fitness by investing more in male offspring than in female offspring during periods of poor environmental quality. To test this hypothesis, we measured the effects of undernutrition and crowding before and during gestation on the sex ratio and weight of offspring at parturition and at weaning in Mus domesticus. Sex ratio was not significantly affected by density. Dams altered the sex ratio of their offspring in response to food availability, but only if variance in competitive success within the experimental subpopulation was evident. Thus ad lib fed females produced litters with an unbiased sex ratio, competitively successful females under moderate food availability produced a male-biased sex ratio, and severely food deprived females produced litters with a female-biased sex ratio. In groups that experienced competition for food, successful dams favoured male offspring during lactation. These results are consistent with the predictions of Trivers and Willard (1973). Analysis of within-cell variance and covariance suggests that the interaction of social structure and food availability provides specific cues for the dams' tactical reproductive choices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00303709
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  • 10
    Electronic Resource
    Electronic Resource
    Characterization of maize endosperm-derived suspension cells throughout the culture cycle and enhancement of tissue friability (1989)
    Springer
    Plant cell, tissue and organ culture 18 (1989), S. 153-165 
    Details
    ISSN: 1573-5044
    Keywords: friability ; fructose ; glucose ; growth cycle ; pH regulation ; sucrose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Batch suspension cultures derived from developing maize (Zea mays L.) endosperm were examined throughout the culture cycle to determine the interaction between the tissue and the medium in relation to sugar transport and the effect of subculturing procedures on growth and friability. The growth rate and friability were improved by increasing the frequency of subculture or by physical screening during transfer. An increase in the conductivity of the medium preceded a decrease in fresh weight associated with tissue senescence. Sucrose in the medium was rapidly hydrolysed, and fructose was depleted more rapidly than glucose. Tissue sucrose concentration expressed on a dry weight basis was higher during the middle of the growth cycle, but hexose, starch, zein, lipid, and soluble protein levels changed very little. The medium pH declined from 5.2 to about 4.5 within one day of subculture. Medium pH changed to 4.5 within one day regardless of initial pH (3.0 to 7.0), indicating regulation of external pH rather than passive acidification. Results are consistent with studies of sugar uptake by these cultures, and indicate that cell clump size can be manipulated without exogenous auxin. The characterization of this tissue line establishes its suitability as a model system for studies of sugar transport and other biochemical events in developing maize endosperm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00047741
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