Characterization of microsatellites for parentage studies of white‐throated magpie‐jays (Calocitta formosa) and brown jays (Cyanocorax morio)

White‐throated magpie‐jays (Calocitta formosa) and brown jays (Cyanocorax morio) are cooperative breeders that live in complex groups composed of helpers and multiple male and female breeders. Behavioral observations and multilocus DNA fingerprinting have indicated that the social and genetic mating systems of these two species are diverse. Extra‐group paternity appears to be common in both species, necessitating the use of single locus genetic methods to efficiently search for fathers. We therefore characterized 19 microsatellite loci for these two species (12 for magpie‐jays and seven for brown jays) to aid in parentage studies.     

Vitamin D Metabolism in Experimental Uraemia: Effects on Intestinal Transport <Superscript>45</Superscript>Ca and on Formation of 1,25-Dihydroxycholecalciferol in Rat

INTESTINAL malabsorption of calcium occurs regularly in patients with advanced renal failure and is commonly associated with rickets or osteomalacia, which closely resemble the osteodystrophy of vitamin D deficiency¹. Large amounts of vitamin D are required to correct this defect in calcium absorption and to promote healing of the bone lesions but the nature of the relative insensitivity to the biological effects of the vitamin is uncertain^1,2. The suggestion³ that vitamin D resistance in uraemia is due to an effective deficiency of 25-hydroxycholecalciferol has been refuted^2,4. The demonstration of the role of the kidney in producing a second biologically potent metabolite, 1,25-dihydroxycholecalciferol^5,6, makes it likely that the abnormalities in uraemic patients are due to loss of renal tissue (see preceding communication⁷).     

Secondary production of Chironomidae (Diptera) in a north temperate stream

SUMMARY 1. Secondary production of chironomids (Diptera: Chironomidae) in a third-order northern Indiana stream was estimated using species-specific, and in most cases cohort-specific, life-history data from the field.
2. Chironomid life-history patterns were diverse, ranging from one to four generations per year in addition to asynchronous development. Cohort production intervals (CPI) for all taxa ranged from 56 to 266 days. CPI for cohorts of conspecifics differed up to 3-fold.
3. Annual secondary production was estimated using the instantaneous growth method or the size—frequency method depending on whether cohorts were distinguishable or not. Total annual chironomid production was 29 700 mg dry mass m⁻², which is the highest value reported for chironomids from a north temperate stream.
4. Eighty per cent of the total chironomid production was attributed to five species: Diamesa nivoriunda (33.9%), Cricotopus bicinctus (16.6%), Pagastia sp. (10.2%), C. trifascia (9.7%) and Orthodadius obumbratus (9.6%).
5. The annual P:B ratio ranged from 4.7 to 21.9. Thus, high secondary production was due to high mean annual standing stocks and not to rapid biomass turnover.