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To cope with changes in the environment, organisms not only show behavioural but also phenotypic adjustments. This is well established for the digestive tract. Here we present a first case of birds adjusting their flight machinery in response to predation risk. In an indoor experiment, ruddy turnstones Arenaria interpres were subjected to an unpredictable daily appearance of either a raptor or a small gull (as a control). Ruddy turnstones experiencing threat induced by a flying raptor model, longer than after similar passage by the gull model, refrained from feeding after this disturbance. Pectoral muscle mass, but not lean mass, responded in a course of a few days to changes in the perceived threat of predation. Pectoral muscle mass increased after raptor scares. Taking the small increases in body mass into account, pectoral muscle mass was 3.6% higher than aerodynamically predicted for constant flight performance. This demonstrates that perceived risk factors may directly affect organ size.  相似文献   
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Book Review     
International Journal of Primatology -  相似文献   
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An antigen making a major contribution to the immune response to Drosophila melanogaster chromatin resides primarily on a nonhistone charge-class family of proteins of Mr 74,000. Immunofluorescence detects this antigen at interbands, puffs and diffuse bands of D. melanogaster salivary chromosomes isolated without exposure to acid fixatives, and on nucleoplasmic ribonucleoprotein droplets. In the electron microscope, gold labelling reveals the binding of monoclonal antibodies specific for the antigen at chromosomal loci generally bearing putative ribonucleoprotein (RNP) particles. However, the locus 3C 11–12 is remarkable in that it bears putative RNP particles but is virtually unlabelled, suggesting protein specificity at different active loci.  相似文献   
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Linkage between the locus for coagulation factor XIIIA (F13A) and HLA-region genes has been revealed during a linkage study between F13A and approximately 40 other polymorphic marker genes. In males, the maximum lod score between F13A and HLA-region genes (HLA-A, -C, -B, -DR; C4A, -B; Bf; and/or C2) is 7.60 at theta 1 = .18. To GLO, the maximum lod score is 2.37 at theta 1 = .19; to PGM3, .22 at theta 1 = .35. Female data indicate a clear sex difference in recombination frequency between F13A and HLA. The present findings, in combination with earlier knowledge of PGM3/GLO/HLA localization and gene distances, show that F13A is distal to HLA on the short arm of chromosome 6 in man. It is thus likely that by including FXIIIA typing in linkage studies, the whole male 6p is within mapping distance of highly polymorphic, classical marker genes. Earlier findings that the Hageman factor gene (F12) is located in the same chromosomal region may indicate the presence of a coagulation factor gene cluster in this region.  相似文献   
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An automated follow-up register for the detection of iatrogenic thyroid disease has been established as a joint venture between the general practitioners in the north-east of Scotland and the thyroid clinic of Aberdeen General Hospitals.The data-processing operations in the system are handled by an International Computers Limited 4/50 computer. Patients are followed up at predetermined intervals and the system has been designed to process, screen, and store clinical and biochemical follow-up data and report results to the patients, general practitioners, and the hospital records department.  相似文献   
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Purine Ribonucleosidase g from Aspergillus foetidus   总被引:1,自引:0,他引:1  
Nucleosidase g was prepared by growing Aspergillus foetidus on bran, and was purified by passage through a diethylaminoethyl-Sephadex column. The enzyme acted on the purine ribosides (except xanthosine) and on their 5'-phosphates. Action on the latter was a good means for preparing ribose-5-phosphate.  相似文献   
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