繁殖前期中国大鲵雄性成体的冲凉行为及其意义

为揭示和探讨中国大鲵(Andrias davidianus)繁殖前期的冲凉行为及其意义,在仿生态养殖环境条件下,采用定时定点观察法和全事件记录法,对雄性成鲵的冲凉行为过程及姿势进行了观察记录,并分析了冲凉行为与年龄、求偶行为、繁殖成功率之间的关系.繁殖前期雄性成鲵表现出冲凉行为,冲凉行为与求偶行为之间存在极显著的正相关,表现出求偶行为的6尾雄性成鲵有4尾成功参与了繁殖.冲凉行为可能促进了雄性成鲵精巢的发育,引发求偶行为,最终达到成功繁殖.     

Factors affecting incidence and severity of leaf spot disease on lettuce caused by Septoria birgitae

In the 1990s during wet seasons a new disease causing brown leaf spots on lettuce (Lactuca sativa) was found for the first time in many lettuce‐growing areas of Austria and Germany. The causal agent, a new pathogenic species called Septoria birgitae, may be responsible for total crop loss. To study how temperature, inoculum density and leaf wetness period influence disease incidence and severity of leaf spot on lettuce caused by S. birgitae, we carried out in vivo experiments in growth chambers and in the field. Additionally, we evaluated the relevance of infected plant debris acting as a primary inoculum source in soil for subsequent crops. S. birgitae produces spores over a wide temperature range between 5°C and 30°C, and can infect plants at temperatures between 10°C and 30°C, with an optimum between 20°C and 30°C. Spores of S. birgitae at a density of at least 10³ conidia mL^–1 are essential for disease outbreak on lettuce. Because leaf wetness is crucial for releasing conidia from pycnidia, we studied the impact of leaf wetness duration on disease development under various temperature conditions. For relevant leaf spot disease development on lettuce in vivo, a leaf wetness duration of at least 24 h and temperatures higher than 10°C were necessary. Leaf spot disease development in the field required several leaf wetness periods longer than 20 h at approximately 15°C at the beginning of crop cultivation. Incorporating S. birgitae infected plant debris in soil as a primary inoculum was not relevant for leaf spot disease outbreak in the next year. However, in cases of continuous cropping of lettuce on the same field and in the same season, Septoria‐infected lettuce debris may become more relevant.     

Spatial memory deficits in maternal iron deficiency paradigms are associated with altered glucocorticoid levels

"The goal of this study was to examine the effect of maternal iron deficiency on the developing hippocampus in order to define a developmental window for this effect, and to see whether iron deficiency causes changes in glucocorticoid levels. The study was carried out using pre-natal, post-natal, and pre + post-natal iron deficiency paradigm. Iron deficient pregnant dams and their pups displayed elevated corticosterone which, in turn, differentially affected glucocorticoid receptor (GR) expression in the CA1 and the dentate gyrus. Brain Derived Neurotrophic Factor (BDNF) was reduced in the hippocampi of pups following elevated corticosterone levels. Reduced neurogenesis at P7 was seen in pups born to iron deficient mothers, and these pups had reduced numbers of hippocampal pyramidal and granule cells as adults. Hippocampal subdivision volumes also were altered. The structural and molecular defects in the pups were correlated with radial arm maze performance; reference memory function was especially affected. Pups from dams that were iron deficient throughout pregnancy and lactation displayed the complete spectrum of defects, while pups from dams that were iron deficient only during pregnancy or during lactation displayed subsets of defects. These findings show that maternal iron deficiency is associated with altered levels of corticosterone and GR expression, and with spatial memory deficits in their pups."     

2007－2012 年佛冈县稻飞虱灯下发生期及种群数量动态分析

明确佛冈县稻飞虱灯下发生期及灯诱种群数量动态,对当地稻飞虱的预测预报和防治工作具有重要意义.根据佛冈县2007-2012年白背飞虱和褐飞虱的灯诱数据,分析了该县白背飞虱和褐飞虱的灯下始见日、终见日、发生期及灯诱量等.结果表明在佛冈地区,白背飞虱和褐飞虱混合发生;白背飞虱的灯下始见日集中在3月底至4月上旬,明显比褐飞虱早一个月,终见日均在10月下旬,差别不大;稻飞虱在早稻和晚稻期间均会出现大小不一的灯诱高峰,早稻期间白背飞虱高峰期集中在5月中旬至6月中旬,褐飞虱灯诱高峰期较迟,主要在7月中旬前后;晚稻期间向背飞虱高峰期大多在9月上旬至10月上旬,褐飞虱高峰期在10月份;早稻期间,白背飞虱的灯诱量占绝对优势,晚稻期间褐飞虱的灯诱量上升,与白背飞虱灯诱量基本持平.因此,佛冈县稻飞虱的灯下发生期及种群数量动态在一定程度上可反映当地稻飞虱的发生情况.     

Fringes of the empire: Diet and cultural change at the Roman to post‐Roman transition in NW Iberia

A growing number of paleodiet investigations over recent years have begun to reveal the stark dietary differences that existed between regions of the Roman Empire, as well as significant changes in subsistence strategies after its fall. The present study explores the dietary changes at the Roman to post‐Roman (Germanic) transition in the Northwest Iberian Peninsula, in order to improve our understanding of the changes that occurred at end of the Roman Empire in different regions across Europe and to also consider the influence of climate had on them. The carbon and nitrogen stable isotope investigation in bone collagen from A Lanzada, NW Spain (100–700 AD), which was an important commercial, coastal settlement has been presented. A human sample of 59 individuals, 6 of them subadults, is compared with 31 faunal specimens, which include a number of marine fish. Isotope data for the terrestrial fauna reveal the influence of the sea on the local isotope baseline. Analysis of the human samples indicates a mixed marine‐terrestrial diet. A shift in mean human δ¹³C values from ?16.7‰ to ?14.3‰ provides clear evidence for a significant change in diet in the post‐Roman period, probably through the intensification of both marine resources exploitation and C₄‐plant consumption (presumably millet). A deterioration of paleoenvironmental conditions, together with a poor socioeconomic situation and the arrival of new people, the Sueves, who brought a new political and socioeconomic system have been discussed as the main causes for the dietary modification in post‐Roman times.     

High fitness costs of climate change‐induced camouflage mismatch

Anthropogenic climate change has created myriad stressors that threaten to cause local extinctions if wild populations fail to adapt to novel conditions. We studied individual and population‐level fitness costs of a climate change‐induced stressor: camouflage mismatch in seasonally colour molting species confronting decreasing snow cover duration. Based on field measurements of radiocollared snowshoe hares, we found strong selection on coat colour molt phenology, such that animals mismatched with the colour of their background experienced weekly survival decreases up to 7%. In the absence of adaptive response, we show that these mortality costs would result in strong population‐level declines by the end of the century. However, natural selection acting on wide individual variation in molt phenology might enable evolutionary adaptation to camouflage mismatch. We conclude that evolutionary rescue will be critical for hares and other colour molting species to keep up with climate change.     

胰岛素注射液启封后有效期内细菌污染情况调查分析

目的:分析生物合成胰岛素注射液启封后有效期内细菌污染情况,并总结其合理的使用方法及时间。方法:收集我院各个科室使用的胰岛素注射液96瓶,启封后分别在不同使用时间和保存温度下采集样本进行细菌学检测。结果:本实验中96瓶启封后有效期内的生物胰岛素注射液中,共有10瓶细菌培养呈阳性,阳性率为10.41%。其中7d之内启封的胰岛素注射液细菌培养全部呈阴性,其余各组的胰岛素注射液细菌培养均呈阳性及存在菌落,随着启封时间的延长,细菌培养阳性率及菌落数上升,且各组之间的差异均具有统计学意义(P0.05)。研究中保存温度2~4℃的细菌培养全部呈阴性,其余各组的胰岛素注射液细菌培养均呈阳性及存在菌落,随着保存温度的升高,细菌培养阳性率及菌落数上升,且各组之间的差异均具有统计学意义(P0.05)。结论:胰岛素注射液启封后有效期内随着时间的延长以及保存温度的升高,细菌培养的阳性率及菌落数量上升,临床使用时要应尽量在7d内使用完,并且尽量保存在低于25℃环境中。     

Underwater acoustic behavior of bearded seals (Erignathus barbatus) in the northeastern Chukchi Sea, 2007–2010

Bearded seal (Erignathus barbatus) calls were recorded using autonomous passive acoustic recorders deployed in the northeastern Chukchi Sea between October 2007 and October 2010. Continuous acoustic data were acquired during summer (August to mid‐October), and overwinter data (mid‐October through July) were acquired on a duty cycle of 40/48 min every 4 h. We investigated the spatio‐temporal distribution and acoustic behavior of vocalizing bearded seals in this multiyear data set. Peaks in calling occurred in spring, coinciding with the mating period, and calls stopped abruptly in late June/early July. Fewer calls were detected in summer, and the vocal presence of seals increased with the formation of pack ice in winter. Vocal activity was higher at night than during the day, with a peak around 0400 (AKST). Monthly patterns in proportional use of each call type and call duration were examined for the first time. The proportion and duration of AL1(T) and AL2(T) call types increased during the mating period, suggesting that males advertise their breeding condition by producing those specific longer trills. The observed seasonal and diel trends were consistent between years. These results improve our understanding of occurrence and acoustic behavior of bearded seals across the northeastern Chukchi Sea.     

濒危植物金花猕猴桃繁殖生物学初步研究

繁殖生物学是目前濒危植物保护生物学研究的重点领域之一,金花猕猴桃(Actinidia chrysantha)是猕猴桃属濒危物种之一,目前未见其繁殖生物学相关报道。因此,该文以分布于花坪国家级自然保护区的野生金花猕猴桃为研究对象,用游标卡尺测量了花器官及果实形态,通过野外观察记录了其物候、访花昆虫及开花结果习性,用人工授粉和套袋法确定其传粉媒介,开展田间播种试验确定种子繁殖力,对其繁殖生物学开展了较为系统的研究。结果表明：金花猕猴桃物候因海拔高度不同而不同,较低海拔地区5月中下旬开花,高海拔地区5月下旬至6月上旬开花,花期持续7~10 d,果实每年9月下旬至10月上旬成熟;雄株花枝率76.5％,雌株果枝率61.9％,果实长圆柱形、短圆柱形或椭圆形,平均单果重7.34~27.53 g,最大果重35.0 g;金花猕猴桃为虫媒和风媒共同授粉,主要访花昆虫有蜜蜂科、细蜂科、鼻蝇亚科、食蚜蝇科、蜡蝉科、大蚊科长脚蚊属昆虫等;金花猕猴桃种子发芽率低,参试的3个居群的种子发芽率存在差异,分别为花坪17.5％,资源车田15.36％,贺州姑婆山0;4种不同种子处理方式中,低温＋GA3处理的种子发芽率(22.67％)最高。综上所述,金花猕猴桃不存在传粉障碍,种子萌发率低可能是致其濒危的重要原因。该研究结果为保护金花猕猴桃种质资源提供了科学依据。