基于改进的SURF指数甄选海州湾鱼类群落的关键捕食者

关键捕食者在生态系统中对饵料生物的数量波动、丰富度和空间分布等都起到重要的调控作用。本研究基于在海州湾进行的5个航次的渔业资源底拖网调查资料及胃含物分析数据,通过对传统SURF指数进行改进,甄选海州湾鱼类群落中的关键捕食者。结果表明: 星康吉鳗、长蛇鲻、大泷六线鱼、小眼绿鳍鱼和小黄鱼为海州湾鱼类群落中的关键捕食者,这5种鱼类不但具有较高的连接数,还是多种生物的主要捕食者,在物种连接中具有较强的聚集效应,它们的数量波动会对生态系统能量流动和食物网结构产生较大的影响。通过本方法对关键捕食者进行甄选,不仅考虑了物种间的摄食比例,还将捕捞量及物种的资源量作为重要影响因素,与传统方法相比,具有较大的改进,为关键捕食者的甄选提供了一种新的方法。本研究还发现,物种之间的强相互作用在维护食物网的结构与功能中起着重要作用,加强对关键捕食者的保护,有利于维持生物群落的稳定性和物种多样性,在实施基于生态系统的管理时,要优先保护这些关键物种。星康吉鳗和小黄鱼作为重要的经济鱼种,承受的捕捞压力较高,尤其需要加强保护和管理。     

吉富罗非鱼群体遗传多样性的AFLP分析

为了分析吉富罗非鱼的遗传多样性,为其育种提供理论依据,本实验利用5对引物组合(E-AGG/M-CTT, E-AGG/M-CTG, E-AAC/M-CAG, E-ACA/M-CTG, E-ACA/M-CAG)对广东省化州光辉养殖场有限公司新选育的吉富罗非鱼第16代群体(F16)进行遗传多样性的AFLP分析.27个个体共检出187个扩增位点,其中多态位点163个,平均每对引物扩增出32.6个位点,多态位点比例87.17%;平均Nei's基因多样性0.2886;平均Shannon's指数0.4339.结果说明实验群体存在较丰富的遗传多样性且保持有较高的遗传杂合度,具有进一步育种和开发的价值.     

The sex ratio of wild Chinese alligators Alligator sinensis

The Chinese alligator Alligator sinensis is one of the most endangered crocodilian species, and typically exhibits temperature-dependent sex determination. It is extremely important to clarify the sex structure of Chinese alligators to implement recovery projects successfully. However, the sex ratio of wild Chinese alligators remains unknown. In this study, we collected 28 years of sex ratio data from Chinese alligators residing in the natural and artificial habitats of Changxing Nature Reserve, China, and examined the differences in the sex ratio dynamics between these two populations. We observed that the sex ratio of wild Chinese alligators is 1 male to 4.507 females, which was significantly lower compared to that of the captive population （1 to 2.040; P 〈 0.001）, and is significantly different to previously documented sex ratios for this species （all P 〈 0.01）. Furthermore, we documented an annually stable （P = 1.000） female-biased sex ratio for wild alligators at hatching [1 male to 4.747 females; 0.174 （0.167~）.182）], in contrast to a dramatically fluctuating sex ratio （P 〈 0.001） in captivity [1 male to 1.674 females; 0.374 （0.246-0.593）], showing a potential mechanism for adjusting the sex structure. Finally, we found that the hatchling sex ratios were similar to that of the population sex ratio （P = 0.748）, with little correlation to air temperature values in the 60-70 day incubation period during the breeding season （July and August; both P 〉 0.05）. Overall, this study indicates that the stabilized female-biased sex ratio of Changxing Chinese alligators might result from selection pressure caused by local mate competition and major inbreeding .     

安徽铜陵叶山次生阔叶混交林主要树种的生态位特征分析

采用样方调查法研究了安徽铜陵叶山次生阔叶混交林不同坡位5个样带中20个主要树种的重要值,并对其中14个主要树种的生态位宽度(包括Levins和Hudbert生态位宽度)、生态位相似比例和生态位重叠值进行了计算和分析.结果表明:各样带中的树种组成明显不同,麻栎(Quercus acutissima Carr.)的重要值在Q2样带中最高,而马尾松(Pinus massoniana Lamb.)的重要值则随着海拔的升高逐渐增大并在Q5样带中达到最高;5个样带中麻栎的重要值总和最高,达195.481,说明麻栎在该次生阔叶混交林中占有明显优势.该群落主要树种麻栎、苦槠[Castanpsis sclerophylla (Lindl.)Schott.]、白栎(Quercus fabri Hance)、青冈栎[Cyclobalanopsis glauca (Thunb.) Oerst.)、石栎[Lithocarpus glaber (Thunb.) Nakai]和山鸡椒(Litsea cubeba (L our.) Pers.]的Levins生态位宽度值分别为0.666、0.664、0.653、0.609、0.594和0.541,Hurlbert生态位宽度值分别为0.856、0.862、0.756、0.613、0.717和0.514,这些主要树种的2项生态位宽度指标均较大且排列顺序基本一致,进一步说明麻栎为该次生阔叶混交林的优势种.该群落中,生态位宽度高的树种间生态位相似比例和生态位重叠值都较高;生态位相似比例在0.3以上的种对有58个,占总种对数的63.7％;生态位重叠值在0.4以上的种对有53个,占总种对数的58.2％,说明该群落尚未演替至稳定的常绿阔叶林群落状态.     

岩生红豆天然林主要树种生态位研究

基于对贵州省岩生红豆(Ormosia saxatilis)天然林群落样地调查,采用定量分析方法对群落不同层次主要树种生态位宽度、生态位相似比例、生态位重叠等进行研究。结果表明:1)采用Levins和Shannon-Wiener两指数测定的生态位宽度值存在较大差异,但前几位顺序基本一致;2)在乔木层中,岩生红豆、云贵鹅耳枥(Carpinus pubescens)、朴树(Celtis sinensis)、青冈栎(Cyclobalanopsis glauca)等具有较大生态位宽度值,其B(SW)i和B(H)i值分别为0.6559、0.5113、0.3635、0.3369和0.9086、0.4545、0.4071、0.3298;3)在灌木层中,岩生红豆、圆果化香(Platycarya longipes)等也具有较大生态位宽度值;4)物种生态位宽度大小体现其对环境的适应范围,宽度越大,适应能力就越强;5)物种生态位宽度大小与生态位重叠值之间有密切关系,生态位宽度大的物种对间一般具有较大的重叠值,生态位宽度较大物种与其它物种间往往具有较大的生态位相似比例和重叠值,重叠值越大,其利用资源的相似程度就越大,竞争就会越激烈。     

Sexual differences and sex ratios of dioecious plants under stressful environments

雌雄异株植物对环境胁迫响应的性别差异与性别比例 雌雄异株植物在性特征(繁殖器官)和次级性特征(植物的特征)均表现出性二态。形态、生理与生态特征等次级性特征的性别差异,通常在繁殖成本和其他功能性状之间存在着权衡。尽管有证据表明性二态对环境胁迫的响应不一定存在于所有植物中,但次级性特征的权衡可能受到环境胁迫的影响。当植物表现出性二态时,不同的物种与胁迫因子可以导致性别特异性的响应。因此,胁迫作用对雌雄异株植物影响的概括性研究是必须的。另外,性二态可能会影响雌雄异株植物沿着环境梯度的频率和分布,引起生态位分化与性别空间分异。目前,控制性别比例偏差的原因和机制还知之甚少。本综述旨在讨论不利环境下的性别特异性响应与性别比例偏差,有利于深入的理解性二态对环境胁迫的响应。     

支气管哮喘急性发作期超敏C-反应蛋白、白细胞、中性粒细胞比例检测的意义及比较

探讨超敏C-反应蛋白（hs-CRP）、血白细胞总数（WBC）、中性粒细胞比例（N％）在支气管哮喘（简称哮喘）急性发作期诊治中的临床意义。方法：分析60例患者治疗前及自觉症状缓解时hs—CRP、WBC、N％动态变化情况,观察上述指标在急性发作期的阳性率以及自觉症状缓解时的阴性率。结果：①hs-CRP、N％、WBC在自觉症状缓解时均明显低于哮喘急性发作期（P〈0．05）;②哮喘患者急性发作期hs—CRP、N％阳性率均高于WBC阳性率,且与后者比较均具有统计学差异（P〈0．05）;③哮喘患者经治疗自觉症状缓解时hs-CRP、WBC阴性率均高于N％阴性率,且与后者比较均具有统计学差异（P〈0．05）。结论-血清hs-CRP既可作为哮喘患者急性发作期感染的敏感指标,又是反映急性发作期治疗效果的早期评判指标,比WBC、N％更迅速、敏感。     

Comparing children's Homo sapiens and chimpanzees' Pan troglodytes quantity judgments of sequentially presented sets of items

We presented a quantity judgment task that involved comparing two sequentially presented sets of items to preschoolers and chimpanzees using nearly identical pr...     

An Efficient Multi-Scale Modelling Approach for ssDNA Motion in Fluid Flow

The paper presents a multi-scale modelling approach for simulating macromolecules in fluid flows. Macromolecule transport at low number densities is frequently encountered in biomedical devices, such as separators, detection and analysis systems. Accurate modelling of this process is challenging due to the wide range of physical scales involved. The continuum approach is not valid for low solute concentrations, but the large timescales of the fluid flow make purely molecular simulations prohibitively expensive. A promising multi-scale modelling strategy is provided by the meta-modelling approach considered in this paper. Meta-models are based on the coupled solution of fluid flow equations and equations of motion for a simplified mechanical model of macromolecules. The approach enables simulation of individual macromolecules at macroscopic time scales. Meta-models often rely on particle-corrector algorithms, which impose length constraints on the mechanical model. Lack of robustness of the particle-corrector algorithm employed can lead to slow convergence and numerical instability. A new FAst Linear COrrector （FALCO） algorithm is introduced in this paper, which significantly improves computational efficiency in comparison with the widely used SHAKE algorithm. Validation of the new particle corrector against a simple analytic solution is performed and improved convergence is demonstrated for ssDNA motion in a lid-driven micro-cavity.     

一种新型中药制剂--肤康的生产

介绍了治疗皮肤病的新型纯中药制剂的配药比例．生产方法及成品检验标准。