Tolerance of disturbance by humans in long-time resident and recent colonist urban doves

Background: A critical trait for successful urban dwelling by birds is the ability to tolerate high levels of disturbing stimulation by humans. If such tolerance is partly acquired gradually after colonization, species with a long history of residence in cities are likely to be more tolerant of such stimulation than recent urban colonists, but this has not often been tested.Methods: We tested whether introduced Rock(Columba livia) and Spotted(Streptopelis chinensis) Doves, historically long-term residents of Melbourne, Australia, were more tolerant of disturbance by humans than the very recent colonist, the native Crested Pigeon(Ochyphaps lophotes) by comparing the Flight Initiation Distances(FID) and time allocations to vigilance during foraging of all three species in urban Melbourne. That all three species are members of the Columbiformes reduces the possibility that any species differences in tolerance are simply phylogenetic in origin.Results: Flight initiation distance was shorter in Rock Doves than in the other two species, which did not differ in approachability by a human. Rock Doves retreated from an approaching human mainly by walking a relatively short distance, Crested Pigeons mainly by running a relatively short distance and Spotted Doves primarily by flying a comparatively long distance. The time allocation to anti-predator vigilance of Rock Doves was smaller than that of the other two species, whose allocations were similar.Conclusions: The very recent colonist of eastern Melbourne, the Crested Pigeon, was not the least tolerant of disturbance by humans of the three related species. Natural selection for tolerance therefore probably cannot entirely explain the pattern of tolerance evident among these urban dove species and behavioural flexibility is probably involved. Length of residency in a city is not an infallible guide to a species’ level of tolerance of disturbance by humans.     

苎麻自交一代分离和变异的研究

1983～1985年以“黄壳早”、“芦竹青”、“古巴苎麻”和“武冈红皮种”为材料进行自交,并观测了自交一代的分离和变异情况,研究结果表明:a.根据自交一代的形态分类,可将“芦竹青”繁殖后代分为40个类型,“芦竹青”自交一代的麻骨颜色分离为四种,其分离比例为9.3:4.2:3:0.7,基本符合孟德尔遗传规律;b.个体间产量性状差异很大,株高变冥为0.23～1.68m,茎粗变异为0.48～1.14 cm,有效株变异为1～23株;c.40个类型的纤维细度的变异呈正态分布,变异为1168～1905公支,最细的类型和最粗的类型相差747支上述结果表明:苎麻自交后代的形态性状、产量性状和纤维细度均产生显著的分离和差异。     

A distinct Mendelian autosomal recessive syndrome involving the association of anotia, palate agenesis, bifid tongue, and polydactyly in the dog.

A presumed genetic syndrome is described in a family of St. Bernards. Four identically affected littermates presented the association of palate agenesis, anotia, incomplete bifid tongue, preaxial hind paw polydactyly, and an extra thoracic vertebra and rib. Pedigree analysis is compatible with an autosomal recessive gene.     

Studies on the suitability of trap-tubs to control noxious rodents in forests

Various types of trap-tubs were tested both under controlled conditions in standardised trial series and in the field. New trap-tubs were poorly accepted by the animals, whereas weathered tubs were readily accepted within a very short period of time. The trapping mechanisms of tubs used in Lower Saxony and improved tubs in Hesse were both found to be suitable. The trapping method proved to be highly selective since long-tailed mice (Apodemus spp.) can easily escape by jumping onto the edge of the tub. Voles (Microtus agrestis, Clethrionomys glareolus) explored the inside of the tub and worked its exits with decreasing intensity during the time of captivity. They died of hypothermia within a few hours. Elimination of the trapped rodents by their natural enemies was not observed. The trials showed that trap-tubs are suitable for selective reduction of the density of field voles and red-backed voles in forests. The results also contribute to assessing the humaneness of the control method.     

Effect of staphylococcal enterotoxin B on cardiorenal functions and survival in X-irradiated rhesus macaques.

Pretreatment of rhesus macaques with nonlethal total-body x-irradiation (400 R) prolonged survival time from an average of 15 hours to 101 hours after intravenous (IV) inoculation of 50 microgram of staphylococcal enterotoxin B (SEB)/kg of body weight. Radiation exposure per se did not produce detectable cardiorenal changes; however, the longer survival after SEB challenge exposure in x-irradiated rhesus macaques was associated with improved cardiorenal functions if compared with that of nonirradiated macaques given the same dose of SEB. Total-body radiation exposure 4 days prior to IV SEB inoculation prevented typical SEB-induced decreases (where measured at 5 hours) in cardiac output, stroke volume, TcH2O, CPAH, Cosm, and urine flow, as well as increases in total peripheral and renal resistance. A theory concerning the significance of radiation-induced leukopenia on modification of SEB-induced cardiorenal functions is postulated.     

采用现代食品加工技术开发蛋白质食物资源

本文分析了现阶段我国人民的食物结构以及食品加工在开发蛋白质食物开源中的地位和作用,并从五个方面进行了论述。