Effects of Amphibian Chytrid Fungus on Individual Survival Probability in Wild Boreal Toads

Abstract: Chytridiomycosis is linked to the worldwide decline of amphibians, yet little is known about the demographic effects of the disease. We collected capture–recapture data on three populations of boreal toads (Bufo boreas [Bufo = Anaxyrus]) in the Rocky Mountains (U.S.A.). Two of the populations were infected with chytridiomycosis and one was not. We examined the effect of the presence of amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]; the agent of chytridiomycosis) on survival probability and population growth rate. Toads that were infected with Bd had lower average annual survival probability than uninfected individuals at sites where Bd was detected, which suggests chytridiomycosis may reduce survival by 31–42% in wild boreal toads. Toads that were negative for Bd at infected sites had survival probabilities comparable to toads at the uninfected site. Evidence that environmental covariates (particularly cold temperatures during the breeding season) influenced toad survival was weak. The number of individuals in diseased populations declined by 5–7%/year over the 6 years of the study, whereas the uninfected population had comparatively stable population growth. Our data suggest that the presence of Bd in these toad populations is not causing rapid population declines. Rather, chytridiomycosis appears to be functioning as a low‐level, chronic disease whereby some infected individuals survive but the overall population effects are still negative. Our results show that some amphibian populations may be coexisting with Bd and highlight the importance of quantitative assessments of survival in diseased animal populations.     

A04-60氨基烘干磁漆抗霉性能研究

目的研究添加和未添加防霉剂的A04-60氨基烘干磁漆的抗霉性能。方法对添加和未添加防霉剂的A04-60氨基烘干磁漆样件进行霉菌试验,并对菌种进行分离、纯化和鉴定。采用扫描电子显微镜(SEM)分析涂层老化、变质特征。结果分离并鉴定出侵蚀菌种,获得了霉菌对A04-60氨基烘干磁漆涂层的侵蚀特征。结论添加防霉剂显著提高了A04-60氨基烘干磁漆的抗霉性能,黑曲霉是侵蚀A04-60氨基烘干磁漆涂层的主要菌种,并造成涂层疏松,且侵蚀孔洞结构随霉菌试验时间的增长而变得粗大。     

生产工艺条件对菌粉爆炸特征参数的影响

利用扫描电镜及激光粒度分析仪,探究了不同生产工艺条件下医药中间体菌粉A和菌粉B的表面形状及粒径分布,并进行了热解分析,证实上述特征参数存在一定差别。在此基础上进行了爆炸特性参数研究。研究结果表明,上述两种菌粉爆炸下限处于70~90 g/m3,最大爆炸压力峰值0.4~0.5 MPa之间,爆炸性相对较弱,但也必须引起足够的重视。与菌粉B相比,菌粉A相对安全,因此条件许可时优先采用菌粉A生产工艺流程。     

蚁群算法在马斯京根模型参数估计中的应用

蚁群算法是一种模拟进化算法,该算法具有许多优越的性质.研究了一种可用于求解连续空间优化问题的蚁群算法策略,针对洪水演算的马斯京根模型参数估计问题,应用连续性空间优化问题的蚁群算法模型进行了求解.应用实例表明,蚁群算法在求解连续空间优化问题中是很有效的,可以广泛应用于各种自然灾害模型的优化问题.     

重庆大气微生物污染状况调查与评价

本文在对重庆大气微生物污染含量调查的基础上，评价分析了重庆大气微生物的污染状况。调查结果表明：城区大气微生物污染高于区县；并分析了霉菌污染普遍性的原因。     

三种菌制剂净化杞麓湖水质的试验研究

在杞麓湖约1200m^2围隔水域的现场试验中，“真光元”、“毫使特”和“光合菌”三种菌制剂对抑制杞麓湖水体中的藻类疯长、提高水体透明度、增加水体溶解氧确有较好效果，且有投加量少、无二次污染产生等特点，三种菌剂的投放均可直接喷洒于水面，易于实施，对人体和环境均无毒副作用。     

黄孢原毛平革菌P450对难降解有机物降解的研究现状

难降解有机物由于具有极大的环境危害,已成为环境保护的一大难题.其降解的主要研究方向是依靠微生物的降解功能.黄孢原毛平革菌(P.C.菌)是研究异源物质代谢最广泛的白腐真菌.目前的研究主要集中在胞外木质过氧化物酶和锰过氧化物酶,而对胞内细胞色素P450降解功能的研究还很少.     

Six years' experience with rapid karyotyping in prenatal diagnosis: Correlations between phenotype detected by ultrasound and fetal karyotype

From September 1985 to March 1992, 804 amniotic fluid samples from 64 different diagnostic centres of the Federal Republic of Germany were sent to our laboratory exclusively for rapid karyotyping. The average time needed for notification of the analysed karyotype was 4·65 days when the ‘pipette method’ was used for chromosome harvesting and 5·97 days when the ‘in situ’ technique was used. The overall incidence of chromosome aberrations was 15·3 per cent. Data are presented about the likelihood of abnormal ultrasound findings being caused by chromosome aberrations. These findings include polyhydramnios, oligohydramnios, growth retardation, fetal effusions, neural tube defects, craniofacial defects, heart defects, gastroschisis and omphalocele, gastrointestinal tract defects, urinogenital defects, and limb defects. In future, such data need to contain larger numbers of cases for each week of gestation. This will improve the risk evaluation for each case with abnormal ultrasound findings, which should lead to better management during pregnancy, delivery, and postnatal care for those who require rapid karyotyping.     

硒胁迫螺旋藻(Spirulina platensis)集落形成及富硒稳定性

探讨在琼脂糖半固体培养基中硒胁迫螺旋藻(Spirulina platensis,SP)集落形成及其富硒稳定性.培养基中添加亚硒酸钠,硒含量分别为2.5mmolL-1、5mmolL-1和10mmolL-1,培养并观察螺旋藻集落形成,挑取藻集落进行富硒培养,多次转种后,测定生长率、硒含量,筛选稳定的富硒螺旋藻.从含硒5mmolL-1的培养皿中挑选12个典型藻丝集落接种培养,发现其中6个生长率达到对照的80%,有两个藻集落(编号为SP0803和SP0809)硒含量较高,干藻硒含量分别为ρ(Se)=924μg/g和ρ(Se)=831μg/g,连续3次转种培养,藻体含硒量保持稳定.以上结果表明,利用琼脂糖半固体培养基进行微藻集落培养是可行的,并成功筛选到富硒螺旋藻.图3表2参12     

稻草秆粉基质中白腐茵对三苯甲烷类染料的降解特性

研究了稻草秆粉基质中自腐菌对三苯甲烷类染料（孔雀绿、溴酚蓝和结晶紫）的降解特性．结果表明，白腐菌10d内对三苯甲烷类染料脱色率均可达到93％以上．染料加入对木素过氧化物酶分泌有抑制作用．随着培养过程的进行，染料脱色率增加，脱色降解以漆酶为主．紫外扫描发现，染料吸收波长有偏移，标志着染料结构发生变化，其中溴酚蓝能被完全矿化．图2表2参10