Influence of dietary feathers on the fecal microbiota in captive Arctic fox: Do dietary hair or feathers play a role in the evolution of carnivorous mammals?

Hair and feathers are composed of keratin and are indigestible, inalimental and unpalatable for carnivores. However, carnivores often ingest hair and feathers during feeding or when grooming. We hypothesized that ingestion of hair and feathers changes species diversity and relative abundance of bacteria in the gut of carnivores. To test this hypothesis, we added disinfected poultry down feathers to the normal diet of captive Arctic foxes (Alopex lagopus). We then used fluorescently labeled terminal restriction fragments (T‐RFs) to examine changes in fecal bacterial diversity and abundance. The results showed that the number of bacterial species increased significantly after feather ingestion, but that total abundance was unchanged. This demonstrated that addition of disinfected feathers to the diet stimulated increased production among less abundant bacteria, resulting in a balancing of relative abundance of different bacterial species, or that some newly‐ingested microbial species would colonize the gut because a suitable microhabitat had become available. This implies that the overall production of bacterial metabolites would be made up of a greater range of substances after feather ingestion. On one hand, the host's immune response would be more diverse, increasing the capacity of the immune system to regulate gut microflora. On the other hand, the animal's physiological performance would also be affected. For wild animals, such altered physiological traits would be subjected to natural selection, and, hence, persistent geographic differences in the character of ingested feathers or fur would drive speciation.     

三倍体方正银鲫(古)同二倍体红鲫(早)杂交胚胎的非整倍体发育

根据囊胚细胞和原肠胚细胞染色体数的观察，三倍体雄性方正银鲫Carassius auratus gihelio)和二倍体雌性红鲫(Carssius auratus red variety)杂交获得的胚胎，是杂合的非整倍体胚胎，因此胚胎发育畸形，中途死亡。胚胎染色体数从50142，变异幅度很宽，86％以上胚胎细胞染色体数分布在56-105范围内，其中以染色体数为76—86的胚胎细胞最常见，占34％。     

珠江卷口鱼年龄生长、食性和繁殖的研究

本文报道了珠江卷口鱼的年龄生长、食住和繁殖方面的研究结果。通过分析确定:卷口鱼的年龄级由I—IV龄鱼组成,各龄鱼分别占渔获物总量的42.21％、38.21％、19.21％和0.38％。用统计学方法,计算出卷口鱼体长与鳞长的相关式为:L=8 43.30R(r=0.9956);体长与体重的相关式为:W=8.226×10~(-3)L~(3.374)(Γ=0.9654)。对卷口鱼各种食物的组成、季节变化及出现率作了分析探讨。卷口鱼个体绝对怀卵量波动于7878—48880粒之间,平均22250.7粒。绝对怀卵量与体长和体重的相关式为:R=4.5419L~(3.6208)和R=40.88W 1209. 文中对卷口鱼的资源繁殖保护,网具使用和合理捕捞规格等问题进行了讨论。     

棉酚对鲤鱼急性中毒的研究

鲤鱼（体重约16克）腹腔注射乙酸棉酚0，7．3，54，100，200，400mg/kg体重，经四天（96小时）后，死亡率分别是0，0，20％，70％，90％，100％。96小时半数致死剂量是63．6mg/kg体重。注射剂量高于54mg/kg体重时，发生腹腔红肿、体壁溃烂，甚至死亡。实验结果说明虽然棉籽水平的棉酚不引起鲤鱼的任何可见的中毒症状，但是腹腔注射大剂量棉酚可引起与哺乳类相似的中毒症状。     

飞船返回舱高海况打捞设备电液控制系统

飞船返回舱高海况打捞设备是我国载人航天工程着陆场系统海上应急救生的重要设备,是解决恶劣海况条件下飞船返回舱的打捞方法和系统装备协调控制问题。通过系统研究与试验,完善了打捞方法与系统装备。系统采用现代液压传动与计算机PLVC编程控制,设计系统报警与故障诊断功能,通过集中监控系统,解决了复杂系统内各种设备的协调操作与自动控制问题;通过电气、液压与CAN-Bus通讯技术的集成,满足了恶劣海况条件下打捞返回舱的各系统设备安全运行和高可靠性的要求。系统设备经过了多次模拟返回舱打捞试验,验证了该项目打捞方法合理可行,系统设备安全可靠。     

对虾、青蟹、江篱混养试验研究

本试验研究改良了池塘水质环境,预防了疾病的发生和避免了虾蟹相残,使以虾为主的虾、蟹、藻混养试验池与对虾单养对照池的对虾成活率大体接近,实现亩均综合产量222.05kg,亩均产值6985.13元,亩均盈利2472.61元,是一种高产、优质、高效的多元化养殖模式。     

中华乌塘鳢人工诱食剂筛选试验

对人工繁育的75日龄中华乌塘鳢（长约4cm，重约0.986g/i）进行一个月饲养试验，从虾粉、海带粉、谷氨酸，甜菜碱，大蒜素等组合成的8种诱食剂中筛选诱食效果最佳者，试验结果表明，在以白鱼粉为主的基础日糖中加入不同配方的诱食剂,对试验鱼的诱食效果不同，其中以2号诱食剂（第三组）的诱食效果最好，增重和成活率拉近鲜虾对照组（第一组）的水平。     

摄食促进剂对对虾生长的影响

IntroductionMeasures to assure that all feed offered to animals in commercial operation is consumed and to reduceformulated feed waste pollution,have been considered as some of the most relevant for lowering productioncosts in aquaculture.Considering the importance of chemical stimulant in development of the crustacean lifecircle,it is logical to assume that by adding attractants to the feed,the animal would rapidly find potentialfeed and ingest it.Additionally,measures involving the incorpora…     

野生苦瓜主要经济性状杂交分离分析

为挖掘利用野生苦瓜优良有利基因,开展苦瓜种质创新,利用野生型小苦瓜M041530和栽培苦瓜高代自交系CY013杂交分离,分析其主要经济性状的分离特点。结果表明:单株产量、结果数、果实纵径、横径、肉厚及单瓜质量等6个经济性状的平均值在F1和F2代均介于双亲之间,其中单株产量和结果数偏向于大值亲本,且在F2出现超亲分离;其他4个性状则偏向于小值亲本;相关分析表明,6个性状的表型相关与遗传相关大小和方向基本一致;对F2代果色性状分离的初步观察显示其呈现数量遗传分离的特征。     

陆地棉铃壳率与产量、早熟性及纤维品质的关系

对22个棉花杂交组合的伏前桃、伏桃、秋桃的铃壳质量进行了研究.结果表明,不同组合间、收获时期间的铃壳质量、铃壳率、棉铃经济系数存在极显著的差异,伏桃的铃壳质量最大,秋桃次之,伏前桃最轻;秋桃的铃壳率最低,伏桃次之,伏前桃最高;秋桃的棉铃经济系数最高,伏桃次之,伏前桃最低.铃壳率降低,有利于产量性状的提高.铃壳率与铃重、小样衣分、单次收花量都呈极显著的负相关,铃壳率与子指呈显著的正相关.铃壳率降低,还能够提高棉花的早熟性,铃壳率与第一次收花率呈极显著的负相关.铃壳率增加,有使纤维品质变优的趋势.铃壳率与马克隆值呈极显著的负相关,铃壳质量、铃壳率与纤维比强度都呈极显著的正相关.