1,012 research outputs found
Larval developmental temperature and ambient temperature affect copulation duration in a seed beetle
The effects of temperature on cellular, systemic and whole-organism processes can be short-term, acting within seconds or minutes of a temperature change, or long-term, acting across ontogenetic stages to affect an organism’s morphology, physiology and behavioural phenotype. Here we examine the effect of larval development temperature on adult copulatory behaviour in the bruchid beetle, Callosobruchus maculatus. As predicted by temperature’s kinetic effects, copulation duration was longest at the lowest ambient temperature. However, where ambient temperature was fixed and developmental temperature experimentally varied, males reared at the highest temperature were least likely to engage in copulation, whilst those reared at the lowest temperature copulated for longer. Previous research has shown males reared at cooler temperatures inseminate fewer sperm. Thus, in this species longer copulations are associated with reduced sperm transfer. We argue that knowledge of preceding ontogenetic conditions will help to elucidate the causes of variation in copulatory behaviour
Nitrogenase of Klebsiella pneumoniae. Interaction of the component proteins studied by ultracentrifugation
Characteristics of N2 fixation in Mo-limited batch and continuous cultures of Azotobacter vinelandii
Rapid Prenatal Diagnosis and Exclusion of Epidermolysis Bullosa Using Novel Antibody Probes
Prenatal diagnosis of recessive dystrophic epidermolysis bullosa was successfully achieved at 19 weeks' gestation by indirect immunofluorescence examination of a fetal skin biopsy sample using the monoclonal antibody LH 7:2. The abortus displayed marked blistering and the diagnosis was confirmed by transmission electron microscopy (TEM). In 3 further pregnancies at risk for lethal junctional epidermolysis bullosa the diagnosis was excluded using the polyclonal antibody AA3. In all these studies the results were available within 4h of receiving the samples. These new techniques offer a quick and simple alternative to TEM for midtrimester prenatal diagnosis of 2 severe recessive forms of epidermolysis bullosa
Glutathione determination by the Tietze enzymatic recycling assay and its relationship to cellular radiation response.
Large fluctuations in glutathione content were observed on a daily basis using the Tietze enzyme recycling assay in a panel of six human cell lines of varying radiosensitivity. Glutathione content tended to increase to a maximum during exponential cell proliferation, and then decreased at different rates as the cells approached plateau phase. By reference to high-performance liquid chromatography and flow cytometry of the fluorescent bimane derivative we were able to verify that these changes were real. However, the Tietze assay was occasionally unable to detect glutathione in two of our cell lines (MGH-U1 and AT5BIVA), although the other methods indicated its presence. The existence of an inhibitory activity responsible for these anomalies was confirmed through spiking our samples with known amounts of glutathione. We were unable to detect a direct relationship between cellular glutathione concentration and aerobic radiosensitivity in our panel of cell lines
Hydrazine is a product of dinitrogen reduction by the vanadium-nitrogenase from Azotobacter chroococcum
Nitrogenase of Klebsiella pneumoniae. Rhodanese-catalysed restoration of activity of the inactive 2Fe species of the Fe protein
Purification and characterization of the assimilatory nitrate reductase of Azotobacter vinelandii
Intellectual disability - the essentials for general practitioners
n this article we introduce the key features and health considerations associated with intellectual disability. Although roughly 1% of the population has an intellectual disability, their needs are frequently overlooked, both in medical training and in clinical practice. This contributes to worse clinical outcomes and excess mortality. General Practitioners have an important role in the co-ordination and delivery of high-quality care for this group
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