Can we reestablish a self-sustaining population?A case study on reintroduced Crested Ibis with population viability analysis

Background:One of the most challenging tasks in wildlife conservation and management is clarifying which and how external and intrinsic factors influence wildlife demography and long-term viability.The wild population of the Crested Ibis(Nipponia nippon)has recovered to approximately 4400,and several reintroduction programs have been carried out in China,Japan and Korea.Population viability analysis on this endangered species has been limited to the wild population,showing that the long-term population growth is restricted by the carrying capacity and inbreeding.However,gaps in knowledge of the viability of the reintroduced population and its drivers in the release environment impede the identification of the most effective population-level priorities for aiding in species recovery.Methods:The field monitoring data were collected from a reintroduced Crested Ibis population in Ningshan,China from 2007 to 2018.An individual-based VORTEX model(Version 10.3.5.0)was used to predict the future viability of the reintroduced population by incorporating adaptive patterns of ibis movement in relation to catastrophe frequency,mortality and sex ratio.Results:The reintroduced population in Ningshan County is unlikely to go extinct in the next 50 years.The popula-tion size was estimated to be 367,and the population genetic diversity was estimated to be 0.97.Sensitivity analysis showed that population size and extinction probability were dependent on the carrying capacity and sex ratio.The carrying capacity is the main factor accounting for the population size and genetic diversity,while the sex ratio is the primary factor responsible for the population growth trend.Conclusions:A viable population of the Crested Ibis can be established according to population viability analysis.Based on our results,conservation management should prioritize a balanced sex ratio,high-quality habitat and low mortality.

Computer Image Analysis as a Tool for Microbial Viability Assessment: Examples of Use and Prospects

Application of the computer image analysis for improving microbial viability assessment by plate count and fluorescence microscopy was investigated. Yeast cells were used as a model microorganism. The application of the improved methods for the viability assessment of yeast cells after preservation by freezing and freeze-drying was demonstrated.

Facing the 2013 Gold Rush: A Population Viability Analysis for the Endangered White-Lipped Peccary (<i>Tayassu pecari</i>) in Corcovado National Park, Costa Rica

The white-lipped peccary (Tayassu pecari) is facing range-wide declines throughout the Neotropics. It has been eliminated from about 89% of its historical range in Costa Rica. Corcovado National Park, in the Osa Peninsula of Costa Rica, is the last remaining stronghold for the white-lipped peccary in the country. In 2013, the Park experienced a sudden gold rush that brought with it a wave of 250 miners and vigorous hunting pressures on the population. Given that the species is endangered and is susceptible to hunting due to its herding behavior and tendency to cohere and attack when threatened rather than flee, it is important to assess its probability of extinction under various hunting scenarios. Incorporating data from studies on the life history of the species throughout its range in the Neotropics and in Corcovado, I used the population viability analysis software VORTEX to simulate the population trajectories and probabilities of extinction of the species under current hunting pressures and under various management scenarios. The results of this study revealed that under the 2013 scenario where 250 miners were present in the Park, the population of white-lipped peccaries has a about a 40% chance of extinction within five years and about a 99% chance of extinction within 10 years. Moreover, there is an “extinction threshold” for the population between the presence of 100 and 150 miners hunting in the Park. At this threshold, the population growth rate, r, drops from a positive growth rate (r = 0.09, SD = 0.08) to a negative one (r = -0.07, SD = 0.29). I suggest that anti-mining and anti-poaching laws be enforced immediately, and that the number of miners be reduced to 100 at a minimum, if not completely, in order to ensure that the population of white-lipped peccaries becomes viable and evades a local extinction.

Analysis of a New Composite Material for Watercraft Manufacturing

In this paper, we investigate the properties of an alternative material for use in marine engineering, namely a rigid and light sandwich-structured composite made of expanded polystyrene and fiberglass. Not only does this material have an improved section modulus, but it is also inexpensive, light, easy to manipulate, and commercially available in various sizes. Using a computer program based on the finite element method, we calculated the hogging and sagging stresses and strains acting on a prismatic boat model composed of this material, and determined the minimum sizes and maximum permissible stresses to avoid deformation. Finally, we calculated the structural weight of the resulting vessel for comparison with another structure of comparable dimensions constructed from the commonly used core material Divinycell.

Image Analysis in Microbiology: A Review

This review is focused on using computer image analysis as a means of objective and quantitative characterizing optical images of the macroscopic (e.g. microbial colonies) and the microscopic (e.g. single cell) objects in the microbiological research. This is the way of making many visual inspection assays more objective and less time and labor consuming. Also, it can provide new visually inaccessible information on relation between some optical parameters and various biological features of the microbial cul-tures. Of special interest is application of image analysis in fluorescence microscopy as it opens new ways of using fluorescence based methodology for single microbial cell studies. Examples of using image analysis in the studies of both the macroscopic and the microscopic microbiological objects obtained by various imaging techniques are presented and discussed.

Jebel Kurun Phosphate Rock Characteristics and Technical Viability to Produce Phosphoric Acid

The technical viability for utilizing Jebel Kurun phosphate reserve in Sudan for the production of a fertilizer grade phosphoric acid is assessed. Statistical analysis has been carried for 56 samples. Phosphate rock has been classified into three main types and then the number of samples representing each type has been identified. Average values for phosphorus pentoxide is 19% and for uranium is 81.47 ppm. The most abundant elements are silicon, aluminum, phosphorus, calcium and iron. Aluminophosphate ore (CaO% ≤ 12%, Al2O3% ≥ 20%, P2O5% ≥ 18%) is represented by 55.36% of sampled phosphate rock. This type can be used to produce phosphoric acid when P2O5 > 30%. Apatite rock including aluminophosphate CaO% ≥ 25%, Al2O3% ≤ 10%, P2O5% ≥ 20%, 12% ≤ SiO2 ≤ 35% is represented by 1.79% of sampled phosphate rock, this type can be used to produce phosphoric acid when it can meet the requirements of (CaO% ≥ 30%, Al2O3% ≤ 7%, P2O5% ≥ 25%, SiO2% ≤ 30%). Silica ore including phosphorus (SiO2% ≥ 40%, P2O5% ≤ 10%) is represented by 16.07% of sampled phosphate rock and Iron ore including phosphorus (Fe2O3% ≥ 20%, P2O5% ≤ 10%) is represented by 5.36% of samples. Both types cannot be used to produce phosphoric acid. The statistical distribution of P2O5 in the size fractions for a core drilled samples is required.

Economic and Financial Viability in Spanish Thermal Power Station

This article tracked, identified, and demonstrated the economic and financial viability of the renewable energy sector from biomass in a Spanish Thermal Power Plant. The methodology used came from Theoretical postulates （GITMAN, 2004; VAN HORNE, 1993） called, Technical Preparation of capital budgets （Economic and Financial Analysis） called, payback, Net Present Value, and Internal Rate of Return）. The economic and financial viability results demonstrated were in two stages： the first identified that the plant is viable according to the payback. The second traced the economic and financial viability from the thermal energy production hypothesis equivalent to electricity power in the amount of 7,699.08 MWh, which resulted in the following indicators： payback of seven years and three months, NPV of R$ 369,064.98, and the IRR of 12.46%. Therefore, managers would have to make a user raising campaign in the ratio of 24.66%, taking into account of an unused capacity of 25%. These indicators were calculated using the following financial data： initial investment of R $ 3,654,731.86, operational income of R $1,262,264.16, operational inputs of R$ 503,639.59, and capital cost of 10.95% over 20 years. This industrial plant is located in the city of Cuellar in northern Spain, having two employees working eight hours a day; it produces only thermal power, represented in this study by MWh of electric power. This industrial plant produces power by burning forest residues from tree pruning. It was concluded that, given the research question developed in this paper--is the study plant profitable from the economic and financial point of view？--The response was identified by calculating the economic and financial indicators that the plant studied is viable from the proposed of maximizing sales revenues to 7,699.08 MWh.

General Economic Analysis about the Wind Farms Repowering in Spain

Environmental pollution and emissions from greenhouse gases caused by fossil fuel use are a threat to sustainable development. With renewable energy sources, no polluting emissions are released into the atmosphere. Therefore, using these sources on a large-scale is a key to reducing emissions and meeting the commitments established by Kyoto Protocol. Moreover, EU wants that the 20% of energy consumption is renewable in 2020. This study describes economic aspects, such as net present value and internal profitability rate, of the repowering process for the wind farms. Repowering can generate considerably more power with fewer facilities. This process was the result of a growing demand for renewable energies, facilitated by the great potential of wind energy in the north of Spain. The wind farms studied in this work were set up before 1998 and they had obsolete machinery with low power. There are strong indications that repowering is a profitable endeavour.

Population viability analysis of small population:a case study for Asian elephant in China

Small populations are at risk of extinction from deterministic and stochastic factors.Less than 250 Asian elephants(Elephas maximus)remain in China,and are distributed in a few isolated areas;yet,population viability analyses of this endangered population have not been conducted.Here,the current genetic status of the Pu’Er-Mengyang Asian elephant populations in China was analyzed,and the risk of extinction was predicted over the next 500 years.Factors affecting the viability of this population were determined through simulations.The genetic diversity of the population was very low(mean allele number:3.1;expected heterozygosity:0.463),even though a recent population bottleneck was not detected.The effective population size was approximately 24.1 adult elephants.Enough adult breeding individuals exist to maintain population viability.VORTEX simulation model showed that this population would not go extinct in the next 500 years.However,illegal poaching and harvesting could negatively affect population size.A sensitivity analysis showed that the mean stochastic growth rate of the study population is sensitive to sex ratio,number of breeding females,mortality of females of different age classes,carrying capacity,and lethal equivalents.Based on our results,we suggest that action should be taken to alleviate inbreeding and any further loss of genetic diversity,by connecting fragmented elephant habitat or by translocating individual elephants.In addition,human–elephant conflict should be mitigated using various modern approaches,including crop guarding techniques,and by encouraging farmers to switch to crops and income sources not vulnerable to elephant raids.

Population viability analysis: using a modeling tool to assess the viability of tapir populations in fragmented landscapes

A population viability analysis(PVA)was conducted of the lowland tapir populations in the Atlantic Forest of the Pontal do Paranapanema region,Brazil,including Morro do Diabo State Park(MDSP)and surrounding forest fragments.Results from the model projected that the population of 126 tapirs in MDSP is likely to per-sist over the next 100 years;however,200 tapirs would be required to maintain a viable population.Sensitiv-ity analysis showed that sub-adult mortality and adult mortality have the strongest influence on the dynamics of lowland tapir populations.High road-kill has a major impact on the MDSP tapir population and can lead to population extinction.Metapopulation modeling showed that dispersal of tapirs from MDSP to the surrounding fragments can be detrimental to the overall metapopulation,as fragments act as sinks.Nevertheless,the model showed that under certain conditions the maintenance of the metapopulation dynamics might be determinant for the persistence of tapirs in the region,particularly in the smaller fragments.The establishment of corridors con-necting MDSP to the forest fragments models resulted in an increase in the stochastic growth rate,making ta-pirs more resilient to threats and catastrophes,but only if rates of mortality were not increased when using cor-ridors.The PVA showed that the conservation of tapirs in the Pontal region depends on:the effective protection of MDSP;maintenance and,whenever possible,enhancement of the functional connectivity of the landscape,reducing mortality during dispersal and threats in the unprotected forest fragments;and neutralization of all threats affecting tapirs in the smaller forest fragments.

Evaluation of viability to simulated gastrointestinal tract passage of probiotic strains and pioneer bioaccessibility analyses of antioxidants in chocolate

Chocolate is appreciated worldwide for its flavor and antioxidant properties.This study aims to evaluate the viability of Lactiplantibacillus plantarum,Lacticaseibacillus casei,and Bacillus subtilis in milk and 70%cocoa chocolates during 90-days.Chocolates incorporated with free and microencapsulated strains were subjected to a gastrointestinal tract(GIT)in vitro passage simulation.Results indicate that survival depends on the strain used;B.subtilis presented the highest performance,with values above 8.0 log CFU/g.GIT simulation demonstrated strains survival during the passage through all the phases,with intestinal phase average values above 7.9 log CFU/g for B.subtilis and L.casei;a factor attributed to the protection provided by the chocolate matrix.Bioaccessibility to phenolics,flavonoids,and antioxidants was also higher in all samples simulated analysis,and 70%cocoa chocolates showed the highest concentrations.The chocolates showed high acceptance in the sensorial analysis.The maintenance of the viability of potential probiotic microorganisms in the food matrix,and the high content of antioxidant compounds,indicate the great potential of chocolate for the diversification of probiotic foods currently available in the market.

社区人群心内膜下心肌活力率的影响因素研究

背景心血管疾病目前在全球范围仍然有很高的发病率和死亡率。心内膜下心肌活力率(SEVR)是侵入性血流动力学研究中分析左心室和主动脉压力曲线引出的一个指标,是评估心肌灌注的一个有价值的工具,在不同人群的心血管不良事件和死亡率方面也具有潜在的预测价值。无创的测量方法可以估测SEVR,虽然有一定局限性,但仍然是评估心肌灌注和心血管风险的有价值的工具并显示出了巨大的临床应用潜力。目前缺乏大规模流行病学调查研究探索SEVR在心血管疾病一级和二级预防中的实际价值。目的在北京社区人群中使用无创方法估测SEVR,并分析其相关影响因素。方法本文基于队列研究的横断面随访,研究对象来源于北京大学第一医院心血管内科2011年12月—2012年4月在北京市石景山区首钢社区建立的动脉粥样硬化研究队列,招募人群为年龄≥40岁的社区居民。2018年随访时采用无创方法进行脉搏波分析检查,并获得SEVR结果。采用线性回归分析探究SEVR的相关影响因素。结果2018年参加随访的6568例研究对象中,排除因心律不齐等未能完成脉搏波分析检查获得SEVR者,最终入选6382例,97.2%的研究对象有SEVR结果。6382例社区居民中男2130例、女4252例,平均SEVR为(144±22)%。线性回归分析结果显示,在总社区居民中,性别(β=-11.00)、年龄(β=-0.53)、吸烟(β=2.36)、高血压(β=-4.12)、脂代谢紊乱(β=-1.45)、糖尿病(β=-4.36)、服用降压药(β=3.72)、降糖治疗(β=-3.71)是SEVR的独立影响因素(P<0.05)。在男性居民中,年龄(β=-0.67)、高血压(β=-3.20)、脂代谢紊乱(β=-2.73)、糖尿病(β=-3.42)及降糖治疗(β=-5.07)是SEVR的独立影响因素(P<0.05)。在女性居民中,年龄(β=-0.48)、吸烟(β=9.44)、高血压(β=-4.98)、糖尿病(β=-4.95)、服用降压药(β=5.26)及降糖治疗(β=-2.82)是SEVR的独立影响因素(P<0.05)。结论无创的SEVR测定在大规模社区人群的队列研究中应用是可行的。SEVR与性别、年龄、吸烟、高血压、脂代谢紊乱、糖尿病这些传统冠心病危险因素相关,其与药物治疗的关系还需要进一步研究探讨。

基于TTC染色的水稻种子活力定量分析

为了揭示种子活力与TTC染色之间的定量关系,本研究以水稻种子CY-150为试验材料,经人工加速老化处理和TTC染色后,利用体视镜获取种子胚部纵切面的RGB图像,并用农业农村部植物新品种测试(昆明)分中心建立的图像分析软件分析图像的CIELab值,计算单位面积染色强度。结果表明,发芽率、TTC染色率和活力指数之间呈显著正相关。其中,发芽率和活力指数、发芽率和染色率、染色率和活力指数之间的相关系数分别为0.9976、0.9718和0.9631。此外,CIELab值与发芽率、染色率和活力指数之间显著相关,其中,L^(*)和a^(*)分别呈负相关和正相关,相关系数分别为-0.9749、-0.9761、-0.9721、0.9737、0.9915和0.9678。利用种子活力指数与CIELab值建立了种子活力方程。通过随机选取4个水稻品种对方程进行验证,结果显示,4个品种的活力指数真实值略高于预测值。研究表明,TTC染色不仅可用于水稻种子活力快速定性分析,而且通过种胚RGB图像可以实现种子活力的定量分析,为进一步普及水稻种子活力快速检测提供参考。

婺源蓝冠噪鹛种群生存力分析

为了解蓝冠噪鹛(Pterorhinus courtoisi)的灭绝风险,预测未来种群变化趋势,采用Vortex 10.5.0模型对蓝冠噪鹛进行种群生存力分析,并模拟不同参数对蓝冠噪鹛种群数量的影响,探索制约蓝冠噪鹛种群增长的主要因子,为该物种的保护管理提供科学依据。结果显示:在标准状态下(考虑近交、灾难因素),蓝冠噪鹛灭绝概率为73%,内禀增长率(R)为0.1480,周期增长率(λ)为1.1595,净生殖率(R0)为1.5046,雌性和雄性的平均世代时间(T)为2.76 a。在9个参数敏感度分析中,性别比例、1岁后雄性死亡率和天敌灾害发生频率3个参数是影响种群数量变化的主要参数。结果表明,在复杂的环境条件下蓝冠噪鹛仍有灭绝风险,其保护工作仍面临较大压力。控制天敌捕食压力、提高蓝冠噪鹛雄鸟成活率,将有益于蓝冠噪鹛种群增长。

MTT法检测RAW264.7细胞活力及可能因素分析

目的通过MTT法检测RAW264.7细胞活力并绘制生长曲线,探讨MTT作用环节中的可能影响因素,优化实验方案。方法以对数生长期的RAW264.7细胞为实验对象,分别用正常培养和脱离血清培养法,记录在不同时间点的OD值。并在加入DMSO后,分别在6、12、24和48h及3、15和30d进行OD值测量。结果加入DMSO后不同时间点的MTT法检测结果,随着时间的延长,结果差异越来越大,超过3d后影响较大,与对照组比较,差异具有统计学意义(P<0.05)。3d内,与对照组比较,差异没有统计学意义(P>0.05)。结论①验证、测量并绘制RAW264.7的生长曲线;②加盖后影响透光度,增大了OD值,影响了实验结果;③随着DMSO时间的延长以第3天为限,否则影响实验结果。

濒危物种保护方法研究进展

对濒危物种的科学内涵、濒危机制和物种保护方法进行综述。具体阐述了种群生存力分析 (PVA)技术和复合种群理论(Meta- population)在濒危物种保护中的应用 ;总结了分子生物学方法在濒危物种保护中的作用 ;探讨了“3S”技术在濒危物种保护中的应用前景。分析和评价了各种保护方法的实用性和局限性 ,提出了各种保护方法在濒危物种保护中的应用前景和发展趋势。总之 ,物种保护方法的不断发展开创了保护生物学研究的新篇章 ,怎样运用交叉学科理论和综合应用各种保护方法探讨物种濒危机制、制定濒危物种有效管理和保护措施 ,是需要进一步解决的科学问题。

鸢尾属7个品种花粉活力及柱头可授性研究

为探索鸢尾属不同品种的花粉活力及柱头可授性的变化规律,从而提高其杂交效率,以鸢尾属7个品种为试验材料,对其开花过程中不同时间的花粉活力和柱头可授性进行观测,并对其结果进行UPGMA聚类分析。结果表明,7个鸢尾品种花粉活力最高期与柱头可授性最高期在时间上不吻合。‘贵格少女’开花后2h花粉即散尽,6-8h柱头可授性保持最高;蓝蝴蝶、黄菖蒲、马蔺、‘音箱’、‘紫褐’和‘平瓣粉’分别于花后2h、2h、4h、6h、6h、6h花粉活力达到最大值,4-24h、4-26h、4-24h、6-8h、6h、6-8h柱头可授性保持最高。在欧式距离D2=2.68处,7个鸢尾品种可分为两大类,第一类包括4个品种,按相似度依次为‘音箱’、‘平瓣粉’、‘贵格少女’和‘紫褐’。第二类包括3个品种,按相似度依次为黄菖蒲、马蔺、蓝蝴蝶。

中国现阶段后备耕地资源经济供给能力分析

后备耕地资源开发是补充建设占用耕地的重要途径。自50年代起,我国政府就非常重视后备耕地资源的调查评价,但是大部分的估算都是从自然适宜性角度出发,在市场经济条件下,后备耕地资源开发的利润是决定后备耕地资源能否开发的重要因素。该文从经济学角度探讨了后备耕地资源的划分及测算方法,并对我国各区域后备耕地资源开发的可能性进行了分析。根据国家土地局1996年完成的土地利用详查,我国现有后备耕地资源661×104hm2(从自然适宜性角度出发进行估算)。该文以此为基础,运用净现值法(NPV)对市场经济条件下的后备耕地资源数量进行估算。经过计算:除了位于东北平原、长白山山地、辽宁平原丘陵、河西走廊平原、河套银川平原、阿拉善高原、东疆盆地以及南疆和北疆的平原的后备耕地资源共236×104hm2在市场经济条件下具有开发价值外,其余地区的后备耕地资源不具备开发价值。即,从自然适宜性角度出发估算的后备耕地资源,大部分在市场经济条件下是不具备开发价值的。

马边大风顶自然保护区大熊猫种群生存力模拟分析

采用漩涡模型Vortexmondel7 3,模拟了马边大风顶自然保护区大熊猫种群在未来 1 0 0年内的变动趋势。结果显示 :在无交配限制、无密度制约、无近亲交配衰退等条件下 ,马边大风顶自然保护区大熊猫种群数量呈下降趋势 ;在考虑近交衰退的影响后 ,遗传多样性水平降低 ,灭绝率提高 ;竹子开花虽能加速大熊猫种群的绝灭 ,但由于保护区分布有多个竹种 ,因此并不会对大熊猫种群产生灾难性影响 ;但是人为捕杀可迅速减少大熊猫种群数量 ,加速其灭绝过程。因此 ,对该保护区大熊猫进行保护的最重要措施就是严格控制人为捕杀 。

秦岭大熊猫(Ailuropoda melanoleuca)的种群存活力分析

以对秦岭野生大熊猫多年研究的资料 ,建立了一个机理性的随机模型 ,并用此模型对秦岭大熊猫种群进行了种群动态的模拟。分析了该种群的存活力 ,结果显示 :秦岭大熊猫种群具有正的增长潜力 ;在环境维持现状的情况下 ,秦岭大熊猫种群以小于 5 %的灭绝概率维持 2 0 0年所需的最小种群规模为 2 8～ 30只 ,低于此数值 ,由于种群统计学随机性 ,种群会有较高的灭绝概率 ;在密度制约因素的影响下 ,种群维持需要 5 0～ 6 0只个体 ;在非密度制约因素的影响下 ,每年由种群中减少的个体不应超过种群数量的 1%。结合秦岭目前大熊猫种群的实际数量 ,秦岭的大熊猫种群由于种群统计学随机性而发生灭绝的可能性很小 ,如果能够在保证现有的环境状况不恶化 ,并且能够逐步恢复的前提下 。