ALBERT

Notes: . Microsporidia are obligate intracellular protozoan parasites that can cause opportunistic infections in AIDS patients. Species from five genera of microsporidia are presently known to infect man. One species, Septata intestinalis originally was detected in stool specimens of individuals with chronic diarrhea and subsequently was found to disseminate to the kidneys, lungs, and nasal sinuses. This organism has since been reclassified as Encephalitozoon and in this study, we report the culture of Encephalitozoon intestinalis from a bronchoalveolar lavage specimen and a nasal mucus aspirate of two AIDS patients living in the USA. The bronchoalveolar and nasal microsporidian isolates grew in several continuous cell lines including RK-13, MDCK, HT-29, Caco-2, Vero, and 1047. Transmission electron microscopy of the clinical and cell culture specimens revealed that the new isolates appeared to be E. intestinalis based on morphology and growth of organisms in septated membrane-bound parasitophorous vacuoles. The new E. intestinalis isolates were characterized and compared with the first isolated E. intestinalis that was cultured from stool to confirm their identity and to determine if there existed any minor differences, as seen in the closely related Encephalitozoon cuniculi strains. By the methods of sodium dodecyl sulfate-polyacrylamide gel electrophoresis staining for proteins and carbohydrates, Western blot immunodetection, and polymerase chain reaction-based methods with restriction endonuclease digestion, double-stranded DNA heteroduplex mobility shift analysis, and DNA sequencing of the ribosomal DNA intergenic spacer region, the new isolates were identical to each other and to the reference isolate of E. intestinalis. In addition, with any of these methods, the E. intestinalis organisms could be distinguished from the three E. cuniculi strains, Encephalitozoon hellem, and Vittaforma corneae, which is important for diagnostics, therapeutic strategies, and epidemiology.

Notes: Three small plot experiments were conducted to investigate the effects of species of grass and forbs, defoliation regime, inclusion of white clover and forb blend on the herbage dry matter (DM) yield, botanical composition and mineral content of swards managed with zero fertilizer inputs. The results of all three experiments were characterized by decline in herbage production and large variations in treatment effects over the harvest period.When sown singly with a standard grass mix the species that competed well with grasses and produced annual forb herbage yields greater than 20 t DM ha−1 were black knapweed, oxeye daisy, ribwort plantain, burnet, birdsfoot trefoil, chicory, kidney vetch, red clover and white clover. When sown singly with a standard forb mix, grass species significantly affected the annual yield of total (P〈005). grass (P〈001) and forb (P〈0.001) herbage. The species that most surpressed the yield of forbs were common bent, Yorkshire fog and perennial ryegrass. Those that allowed for the highest yield of forbs were rough meadow grass, sweet vernal grass and crested dogstail. Averaged over the three harvest years, defoliation regime did not significantly affect herbage production, but the inclusion of white clover in mixtures increased the yield of grasses (P〈0.01) The use of rosette-type forb blends increased forb yield (P〈0.01), compared with erect-type blends.The effects of treatments on herbage N and mineral contents and yields were inconsistent. However, there was some evidence to support the view that the presence of forb species in swards can result in greater contents of minerals in herbage, compared with grass-only swards.

Notes: Upper lethal temperature tolerance was determined for 26–81 mm, age 0 black crappie Pomoxis nigromaculatus of three size classes using both a rapid transfer and slow heating protocol. Rapid transfer protocols determined 24 LT50 values of 33–8, 35–1 and 31–5° C for size classes with mean total lengths of 30–2, 45–6 and 74–9 mm. A predictive model was generated from the slow heating protocols that relates lethal temperature to acclimation temperature, total length, and condition factor (K) as predictors.

Notes: Mutation breeding was used to produce mutants of the potato breeding selection NDA1725-1 with reduced levels of tuber glycoalkaloids. Excised tuber eye-pieces were exposed to 35 Gy of gamma rays from a 60Co source. In the M1V1, leaf tissue was screened using high-performance thin layer chromatography and each plant given a relative score based on a subjective rating of band intensity. Tubers were harvested from all plants that produced leaves with relatively low levels of glycoalkaloids. Tuber glycoalkaloids were quantified in the M1V2 and M1V3 using high-performance liquid chromatography, and 35% and 23% of clones with the lowest glycoalkaloid content were selected for further evaluation in each generation, respectively. In the M1V4, M1V5 and M1V6, selection was based on statistically significant differences between the mutant clones and the controls for glycoalkaloid content, as determined using a gravimetric quantification method, as well as on agronomic and quality characteristics. At the end of six clonal generations three selections exhibited acceptable levels of tuber glycoalkaloids and retained enough of the parent clone's exceptional traits to have potential in the commercial potato chip (crisp) industry.

Notes: Humpback whales feed in several high-latitude areas of the North Pacific. We examined the interchange of humpback whales between one of these areas, off California, and those in other feeding grounds in the eastern North Pacific:. Fluke photographs of 597 humpback whales identified off California between 1986 and 1992 were compared with those off Oregon and Washington (29); British Columbia (81); southeastern Alaska (343); Prince William Sound, Alaska (141); Kodiak Island, Alaska (104); Shumagin Islands, Alaska (22); and in the Bering Sea (7). A high degree of interchange, both inter-and intrayear, was found among humpback whales seen off California, Oregon, and Washington., A low rate of interchange was found between British Columbia and California.: two whales seen near the British Columbia/Washington border were photographed off California in a different year, No interchange was found between California and the three feeding areas in Alaska. Humpback whales off California, Oregon, and Washington form a single intermixing feeding aggregation with only limited interchange with areas farther north. These findings are consistent with photographic identification studies in the North Atlantic and with genetic studies in both the North Atlantic and North Pacific.

Notes: We investigated the synthesis and translocation of amino compounds in Parasponia, a genus of the Ulmaceae that represents the only non-legumes known to form a root nodule symbiosis with rhizohia. In the xylem sap of P. andersonii we identified asparagine. aspartate. glutamine, glutamated significant quantities of a non-protein amino acid. 4-methylglutamte(2-amino-4-methylpentanedioic acid). This identification was confirmed by two methods, capillary gas chromatography (GC) electron ionization (El) mass spectrometry (MS) and reverse phase high pressure liquid chromatography (HPLC) analysis of derivatized compounds. In leaf, root and nodule samples from P. andersonii and P. parviflora we also identified the related compounds 4-methyleneglutamate and 4-methyleneglulamine. Using 15N2 labelling and GC-Ms analysis of root nodule extracts we followed N2 fixation and ammonia assimilation in P. andersonii root nodules and observed Label initially in glutamine and subsequently in glutamate, suggesting operation of the glutamine synthetase/glutamine:2-oxoglutarate aminotransferase (GS/GOGAT) pathway. Importantly, we observed the incorporation of significant quantities of 15N into 4-methylglutamate in nodules, demonstrating the de nova synthesis of this non protein amino acid and suggesting a role in the translation of N in symbioticParasponia.

Notes: Early concretionary and non-concretionary siderites are common in subsurface Triassic sandstones and mudrocks of the Rewan Group, southern Bowen Basin. A detailed petrological and stable isotopic study was carried out on these siderites in order to provide information on the depositional environment of the host rocks. The siderites are extremely pure, containing 85–97 mol% FeCO3, and are commonly enriched in manganese. δ13C (PDB) values are highly variable, ranging from - 18·4 to +2·9‰, whereas δ18O (PDB) values are very consistent, ranging from - 14·0 to - 10·2‰ (mean= - 11·9 ± 1·0‰). The elemental and oxygen isotopic composition of the siderites indicates that only meteoric porewaters were involved in siderite formation, implying that host rocks accumulated in totally non-marine environments. The carbon isotopic composition of the siderites is interpreted to reflect mixing of bicarbonate/carbon dioxide generated by methane oxidation and methanogenesis. Very low δ13C values demonstrate that, contrary to current views, highly 13C-depleted siderite can be produced at shallow burial depths in anoxic non-marine sediments.

Notes: Over a 56-day feeding period, during which juvenile African catfish, Clarias gariepinus (Burchell) increased in body weight at least threefold, diets containing fresh or rancid oils (0.352 and 9.133 mmol MDA equivalents per g oil, respectively) at two levels of supplemental vitamin E (20 or 100 mg all-rac-α-tocopheryl acetate kg-1 dry diet) were fed at 3% body weight per day. On termination of the feeding trial, growth performance and food utilization were assessed. Additionally, health criteria such as hepatosomatic index (HSI), haematocrit, plasma haemoglobin and plasma α-tocopherol concentration were determined. Plasma α-tocopherol was seen to increase significantly (P 〈 0.05) concomitant with dietary dose of the vitamin. Oxidation of dietary lipid source was observed to cause significant depletion (P 〈 0.05) of α-tocopherol from the plasma pool on consumption of the rancid test-diets. Final body weights of the catfish revealed that vitamin E supplementation in rancid diets significantly improved growth (P 〈 0.05), although supplementation into fresh-oil diets did not result in appreciable benefits in terms of final attained weight (P 〉 0.05). Values of other growth parameters and nutrient utilization indices were seen to respond positively to increased vitamin E levels and fresher dietary oils. With respect to other health indices, HSI was strongly correlated (P 〈 0.05) to dietary vitamin E dose and not oil oxidation state, with catfish fed lower α-tocopherol doses exhibiting larger livers proportional to somatic mass. Haematocrit values were significantly (P 〈 0.05) lower in fish fed low-tocopherol/fresh-oil diets. Although no measurably significant differences were found between treatments with respect to plasma-haemoglobin concentration, higher mean values for the fish fed rancid oils at the lower α-tocopherol inclusion level may indicate heightened Spontaneous haemolysis in this group. Mechanisms to account for dietary modulation of health indices in catfish under the present dietary regime are postulated. It was concluded that supplemental α-tocopheryl acetate in diets likely to undergo oxidation, would protect catfish from the nutritional stress imposed by rancid oils and increase growth above levels associated with unsupplemented dietary treatments.

Notes: Production of hepatic docosahexaenoic acid in juvenile Clarias gariepinus was significantly increased (P 〈0.05) by ingestion of rancid diets and this effect was modulated by dietary vitamin E. This has not been described previously in fish. Causal mechanisms are postulated.