Loss of Skeletal Calcium by Patients on Maintenance Dialysis

Direct radiological measurements of the mineral content of femoral bone were performed in 13 patients on maintenance dialysis. They were found to be sufficiently sensitive to be used for monitoring, and it is suggested that the technique gives more information than do calcium-balance studies.     

Inhibition by 6-mercaptopurine of purine phosphoribosyltransferases from Ehrlich ascites-tumour cells that are resistant to this drug

1. A strain of Ehrlich ascites-tumour cells that showed little inhibition of growth in the presence of 6-mercaptopurine accumulated less than 5% as much 6-thioinosine 5′-phosphate in vivo, in the presence of 6-mercaptopurine, as did the sensitive strain from which it was derived. 2. Specific activities of the phosphoribosyltransferases that convert adenine, guanine, hypoxanthine and 6-mercaptopurine into AMP, GMP, IMP and 6-thioinosine 5′-phosphate were similar in extracts of the resistant and the sensitive cells. 3. As found previously with sensitive cells, 6-mercaptopurine is a competitive inhibitor of guanine phosphoribosyltransferase and hypoxanthine phosphoribosyltransferase from the resistant cells and does not inhibit the adenine phosphoribosyltransferase from these cells. Michaelis constants and inhibitor constants of the purine phosphoribosyltransferases from resistant cells did not differ significantly from those measured with the corresponding enzymes from sensitive cells. 4. Resistance to 6-mercaptopurine in this case is probably not due to qualitative or quantitative changes in these transferases.     

Post-marital residence patterns show lineage-specific evolution

Where a newly-married couple lives, termed post-marital residence, varies cross-culturally and changes over time. While many factors have been proposed as drivers of this change, among them general features of human societies like warfare, migration and gendered division of subsistence labour, little is known about whether changes in residence patterns exhibit global regularities. Here, we study ethnographic observations of post-marital residence in societies from five large language families (Austronesian, Bantu, Indo-European, Pama-Nyungan and Uto-Aztecan), encompassing 371 ethnolinguistic groups ranging widely in local ecologies and lifeways, and covering over half the world's population and geographical area. We apply Bayesian comparative methods to test the hypothesis that post-marital residence patterns have evolved in similar ways across different geographical regions. By reconstructing past post-marital residence states, we compare transition rates and models of evolution across groups, while integrating the historical descent relationships of human societies. We find that each language family possesses its own best fitting model, demonstrating that the mode and pace of post-marital residence evolution is lineage-specific rather than global.     

Range contraction and increasing isolation of a polar bear subpopulation in an era of sea‐ice loss

Climate change is expected to result in range shifts and habitat fragmentation for many species. In the Arctic, loss of sea ice will reduce barriers to dispersal or eliminate movement corridors, resulting in increased connectivity or geographic isolation with sweeping implications for conservation. We used satellite telemetry, data from individually marked animals (research and harvest), and microsatellite genetic data to examine changes in geographic range, emigration, and interpopulation connectivity of the Baffin Bay (BB) polar bear (Ursus maritimus) subpopulation over a 25‐year period of sea‐ice loss. Satellite telemetry collected from n = 43 (1991–1995) and 38 (2009–2015) adult females revealed a significant contraction in subpopulation range size (95% bivariate normal kernel range) in most months and seasons, with the most marked reduction being a 70% decline in summer from 716,000 km² (SE 58,000) to 211,000 km² (SE 23,000) (p < .001). Between the 1990s and 2000s, there was a significant shift northward during the on‐ice seasons (2.6^° shift in winter median latitude, 1.1^° shift in spring median latitude) and a significant range contraction in the ice‐free summers. Bears in the 2000s were less likely to leave BB, with significant reductions in the numbers of bears moving into Davis Strait (DS) in winter and Lancaster Sound (LS) in summer. Harvest recoveries suggested both short and long‐term fidelity to BB remained high over both periods (83–99% of marked bears remained in BB). Genetic analyses using eight polymorphic microsatellites confirmed a previously documented differentiation between BB, DS, and LS; yet weakly differentiated BB from Kane Basin (KB) for the first time. Our results provide the first multiple lines of evidence for an increasingly geographically and functionally isolated subpopulation of polar bears in the context of long‐term sea‐ice loss. This may be indicative of future patterns for other polar bear subpopulations under climate change.     

The Hermes element from Musca domestica can transpose in four families of cyclorrhaphan flies

Transgenic insect technology will provide opportunities to explore the basic biology of a broad range of insect species in ways that will prove insightful and important. It is also a technology that will provide opportunities to manipulate the genotypes of insects of practical significance to the health and welfare of humans. TheHermes transposable element from the housefly,Musca domestica, is a short inverted repeat-type element related tohobo fromDrosophila melanogaster, Ac fromZea mays, andTam3 fromAntirrhinum majus. It has potential to become a versatile and efficient broad host-range insect transformation vector. The ability ofHermes to transpose when introduced into five species of diptera from four divergent families was tested using anin vivo, interplasmid transpositional recombination assay.Hermes was capable of transposing in all species tested, demonstrating thatHermes has a broad host-range. In addition, the rates of transposition were sufficiently high in all species tested to suggest thatHermes will be an efficient gene transfer vector in a wide range of insect species. TheHermes element also revealed a pattern of integration into the target substrate that permitted factors determining integration site selection to be identified. Primary nucleotide sequence of the integration site played a role as did proximity to preferred integration sites and the nucleosomal organization of the target.     

The Difference Between Activity When in Bed and Out of Bed. I. Healthy Subjects and Selected Patients

The activity records of five groups of healthy or ill subjects have been measured for 4-26 days by an accelerometer placed on the nondominant wrist. These data, together with a record of times retiring to/rising from bed, have been used to produce a series of dichotomy indices for comparing the amounts of activity when in bed and out of bed. Reliable differences between individuals were found, with healthy subjects showing a greater degree of dichotomy than one subject with delayed sleep phase syndrome or three subjects with colorectal cancer. The method is convenient for extended data collection and offers the possibility of describing an individual's activity profile in a variety of circumstances.