湿地生态系统服务、功能和价值评价研究进展

随着对湿地重要性认识的加深,湿地生态系统的服务价值越来越受到人们的重视.湿地生态系统服务价值评价的成果可为制定惩处破坏者及补偿损失者政策提供科学依据.本文在界定湿地生态系统服务、功能和价值之间关系的基础上,总结了当前湿地生态系统服务功能价值评价的方法和应用特点,主要包括市场价格法、生产函数法、机会成本法、影子工程法、生产力变化法、人力资本法、旅行费用法、享乐价值法、权变价值评估和生态价值法.讨论了影响评价结果的因素及相关研究中存在的问题,并对今后的发展前景进行展望.     

生态系统多功能性的测度方法

生物多样性与生态系统多功能性(biodiversity and ecosystem multifunctionality, BEMF)之间的关系是目前生态学研究的一个热点, 其中, 生态系统多功能性(EMF)的测度方法是研究该问题的技术关键。由于缺乏统一的认识, 目前存在多个多功能性的测度方法, 这使人们对生物多样性与生态系统多功能性之间关系的理解复杂化。本文介绍了国际上常用的单功能法、功能-物种替代法、平均值法、单阈值法、多阈值法、直系同源基因法和多元模型法的原理及其特点, 并对其中较难理解的多阈值法进行了举例说明, 希望能对理解EMF的测度方法有所帮助。本文按不同的EMF测度方法对已发表的有关文章进行了归类, 以期帮助读者更好地选择EMF的测度方法。由于缺乏相对统一的、代表各个层次的生态系统功能的测度方法, 导致不同的研究结果难以相互比较, 严重限制了生物多样性与生态系统多功能性研究的发展; 所以, 研发新的、具有普遍适用性的EMF测度方法已成为当务之急。     

Powerful Exact Unconditional Tests for Agreement between Two Raters with Binary Endpoints

Asymptotic and exact conditional approaches have often been used for testing agreement between two raters with binary outcomes. The exact conditional approach is guaranteed to respect the test size as compared to the traditionally used asymptotic approach based on the standardized Cohen''s kappa coefficient. An alternative to the conditional approach is an unconditional strategy which relaxes the restriction of fixed marginal totals as in the conditional approach. Three exact unconditional hypothesis testing procedures are considered in this article: an approach based on maximization, an approach based on the conditional p-value and maximization, and an approach based on estimation and maximization. We compared these testing procedures based on the commonly used Cohen''s kappa with regards to test size and power. We recommend the following two exact approaches for use in practice due to power advantages: the approach based on conditional p-value and maximization and the approach based on estimation and maximization.     

新生隐球菌总RNA抽提方法的实验研究

目的探讨快速获取高质量的新生隐球菌总RNA的实验方法。方法选取新生隐球菌的荚膜株、荚膜缺陷株,分别设计采用4种方法提取总RNA:酸洗玻璃珠法、液氮研磨法、异硫氰酸胍一步法、冷酸洗玻璃珠联合Yeast RNA kit法。用紫外线分光光度计测量其OD260、OD280的值,并且进行琼脂糖凝胶电泳,同时应用定量PCR法鉴定RNA质量。结果酸洗玻璃珠法、液氮研磨法、异硫氰酸胍一步法、冷酸洗玻璃珠联合Yeast RNA kit法的RNA产量分别为0.2μg/105细胞、0.4μg/105细胞、0.1μg/105细胞、0.6μg/105细胞。结论冷酸洗玻璃珠联合Yeast RNA kit法提取的RNA均一性和完整性最好,是简便、快捷地提取具有荚膜和细胞壁双重屏障的新生隐球菌RNA的理想方法。     

Marginal analyses of clustered data when cluster size is informative

We propose a new approach to fitting marginal models to clustered data when cluster size is informative. This approach uses a generalized estimating equation (GEE) that is weighted inversely with the cluster size. We show that our approach is asymptotically equivalent to within-cluster resampling (Hoffman, Sen, and Weinberg, 2001, Biometrika 73, 13-22), a computationally intensive approach in which replicate data sets containing a randomly selected observation from each cluster are analyzed, and the resulting estimates averaged. Using simulated data and an example involving dental health, we show the superior performance of our approach compared to unweighted GEE, the equivalence of our approach with WCR for large sample sizes, and the superior performance of our approach compared with WCR when sample sizes are small.     

Outlier detection methods are still effective even using virtual species created with the probabilistic approach

Liu et al. (Journal of Biogeography, 2018, 45 :164–176) presented an approach to detect outliers in species distribution data by developing virtual species created using the threshold approach. Meynard et al. (Journal of biogeography, 2019, 46 :2141–2144) raised concerns about this approach stating that ‘using a probabilistic approach … may significantly change results’. Here we provide a new series of simulations using the two approaches and demonstrate that the outlier detection approach based on pseudo species distribution models was still effective when using the probabilistic approach, although the detection rate was lower than when using the threshold approach.     

Effect of Risk on Aspects of Escape Behavior by a Lizard, Holbrookia propinqua, in Relation to Optimal Escape Theory

Prey must balance gains from activities such as foraging and social behavior with predation risk. Optimal escape theory has been successful in predicting escape behavior of prey under a range of risk and cost factors. The optimal approach distance, the distance from the predator at which prey should begin to flee, occurs when risk equals cost. Optimal escape theory predicts that for a fixed cost, the approach distance increases as risk increases. It makes no predictions about approach distance for prey in refuges that provide only partial protection or about escape variables other than approach distance, such as the likelihood of stopping before entering refuge and escape speed. By experimentally simulating a predator approaching keeled earless lizards, Holbrookia propinqua, the predictions of optimal escape theory for two risk factors, predator approach speed and directness of approach were tested. In addition, predictions that the likelihood of fleeing into refuge without stopping and the speed of escape runs increase with risk, in this case predator approach speed, and that lizards in incompletely protective refuges permit closer approach than lizards not in refuges were also tested. Approach distance increased with predator approach speed and directness of approach, confirming predictions of optimal escape theory. Lizards were more likely to enter refuge and ran faster when approached rapidly, verifying that predation risk affects escape decisions by the lizards for escape variables not included in optimal escape theory. They allowed closer approach when in incompletely protective refuges than when in the open, confirming the prediction that risk affects escape decisions while in refuge. Optimal escape theory has been highly successful, but testing it has led to relative neglect of important aspects of escape other than approach distance.     

Donor Conception Disclosure: Directive or Non-Directive Counselling?

It is widely agreed among health professionals that couples using donor insemination should be offered counselling on the topic of donor conception disclosure. However, it is clear from the literature that there has long been a lack of agreement about which counselling approach should be used in this case: a directive or a non-directive approach. In this paper we investigate which approach is ethically justifiable by balancing the two underlying principles of autonomy (non-directive approach) and beneficence (directive approach). To overrule one principle in favour of another, six conditions should be fulfilled. We analyse the arguments in favour of the beneficence principle, and consequently, a directive approach. This analysis shows that two conditions are not met; the principle of autonomy should not be overridden. Therefore, at this moment, a directive counselling approach on donor conception disclosure cannot be ethically justified.     

On prediction of genetic values in marker-assisted selection.

We suggest a new approximation for the prediction of genetic values in marker-assisted selection. The new approximation is compared to the standard approach. It is shown that the new approach will often provide substantially better prediction of genetic values; furthermore the new approximation avoids some of the known statistical problems of the standard approach. The advantages of the new approach are illustrated by a simulation study in which the new approximation outperforms both the standard approach and phenotypic selection.     

经肛门改良Soave术和经腹治疗先天性巨结肠的疗效对比研究

目的：探讨经肛门改良Soave术和经腹治疗先天性巨结肠的临床疗效。方法：对大于3岁的41例患儿（经肛门改良Soave术治疗28例,经腹治疗24例,在术后并发症和排便功能等方面进行回顾性对比分析。结果：并发症的总发生率经肛门改良Soavc术明显少于经腹。HAEC发生率低于经腹组,有统计学意义。总的排便控制和大便形态方面经肛门改良Soave术优于经腹。结论：经肛门改良Soave术治疗先天性巨结肠方法可行、安全,效果优于经腹,但是术后仍有诸多并发症,特别在排便控制方面,仍需大量的病例进行长期的随访研究评估。     

Towards autonomic performance management of large scale data centers using interaction balance principle

In this paper, an autonomic performance management approach is introduced that can be applied to a general class of web services deployed in large scale distributed environment. The proposed approach utilizes traditional large scale control-based algorithms by using interaction balance approach in web service environment for managing the response time and the system level power consumption. This approach is developed in a generic fashion that makes it suitable for web service deployments, where web service performance can be adjusted by using a finite set of control inputs. This approach maintains the service level agreements, maximizes the revenue, and minimizes the infrastructure operating cost. Additionally, the proposed approach is fault-tolerant with respect to the failures of the computing nodes inside the distributed deployment. Moreover, the computational overhead of the proposed approach can also be managed by using appropriate value of configuration parameters during its deployment.     

经肛门改良Soave 术和经腹治疗先天性巨结肠的疗效对比研究

目的:探讨经肛门改良Soave术和经腹治疗先天性巨结肠的临床疗效。方法:对大于3岁的41例患儿(经肛门改良Soave术治疗28例,经腹治疗24例,在术后并发症和排便功能等方面进行回顾性对比分析。结果:并发症的总发生率经肛门改良Soave术明显少于经腹,HAEC发生率低于经腹组,有统计学意义。总的排便控制和大便形态方面经肛门改良Soave术优于经腹。结论:经肛门改良Soave术治疗先天性巨结肠方法可行、安全,效果优于经腹,但是术后仍有诸多并发症,特别在排便控制方面,仍需大量的病例进行长期的随访研究评估。     

Community perceptions on the community-directed treatment and school-based approaches for the control of schistosomiasis and soil-transmitted helminthiasis among school-age children in Lushoto District, Tanzania

The success of the Community-Directed Treatment (ComDT) approach in the control of onchocerciasis and filariasis has caught the attention of other disease control programmes. In this study the ComDT approach was implemented and compared with the school-based approach for control of schistosomiasis and soil-transmitted helminthiasis among school-age children in Lushoto District, Tanzania. This was a qualitative study, consisting of in-depth interviews with village leaders, community drug distributors (CDDs) and schoolteachers, as well as focus group discussions with separate groups of mothers and fathers to assess the perceptions and experiences of the villagers on the implementation of the two approaches. It was found that the villagers accepted the ComDT approach and took the responsibility of selecting the CDDs, organizing and implementing their own method of distributing drugs to the school-age children in their villages. The ComDT approach was well received and was successfully implemented in the villages. Although the villagers pointed out the limitation in reaching the non-enrolled children in the school-based approach, they also expressed satisfaction with this approach. This study suggests that the ComDT approach is well accepted and can be implemented effectively to ensure better coverage of especially non-enrolled school-age children.     

Can interaction coefficients be determined from census data? Testing two estimation methods with Negev Desert rodents

Two approaches based on regression models are proposed to estimate competition from census data. The "static" approach is based on censuses of population sizes among species at one point in time over many sites. The "dynamic" approach relies on a time series of species abundance data to examine whether per capita changes in one species are associated with the abundance of other species. We estimated competition interactions in a Negev rodent community consisting of 10 species using both approaches, basing on 8 years (16 half-year periods) of observations. The static approach revealed significant competitive interactions in four of 45 pairs of species, whereas the dynamic approach did so in the same four plus two more pairs. For each species pair, both approaches revealed significant negative interactions in only 1–4 of 16 seasons. The static approach provided nearly symmetric estimations of competition, whereas estimations of dynamic approach were asymmetric. Moreover, estimations of the two approaches did not coincide in time. Cases of negative interactions recorded by the static approach were more frequent at peak and increase phases of population density dynamics, whereas those recorded by the dynamic approach were more frequent at peak and decline phases. Results of field removal experiments with Mus musculus and Gerbillus dasyurus supported predictions of dynamic but not static approaches. We hypothesized that in harsh and fluctuating desert environments that disrupt equilibrium, the dynamic approach indicates true (exploitation) competition, whereas the static approach reflects negative interspecific spatial association (interference).     

A new approach for estimating the efficiencies of the nucleotide substitution models

In this article, a new approach is presented for estimating the efficiencies of the nucleotide substitution models in a four-taxon case and then this approach is used to estimate the relative efficiencies of six substitution models under a wide variety of conditions. In this approach, efficiencies of the models are estimated by using a simple probability distribution theory. To assess the accuracy of the new approach, efficiencies of the models are also estimated by using the direct estimation method. Simulation results from the direct estimation method confirmed that the new approach is highly accurate. The success of the new approach opens a unique opportunity to develop analytical methods for estimating the relative efficiencies of the substitution models in a straightforward way.     

A dynamic approach to tolerate soft errors

Dynamic implementation for software-based soft error tolerance method which can protect more types of codes can cover more soft errors. This paper explores soft error tolerance with dynamic software-based method. We propose a new dynamic software-based approach to tolerate soft errors. In our approach, the objective which is protected is dynamic program. For those protected dynamic binary codes, we make sure right control flow and right data flow to significant extent in our approach. Our approach copies every data and operates every operation twice to ensure those data stored into memory are right. Additionally, we ensure every branch instruction can jump to the right address by checking condition and destination address. Our approach is implemented by the technique dynamic binary instrumentation. Specifically, our tool is implemented on the basis of valgrind framework which is a heavyweight dynamic binary instrumentation tool. Our experimental results demonstrate that our approach can get higher reliability of dynamic software than those approaches which is implemented with static program protection method. However, our approach is only suitable for the system which has a strict requirement of reliability because our approach also sacrifices more performance of software than those static program protection methods.     

Linkage disequilibrium mapping of quantitative-trait Loci by selective genotyping

The principles of linkage disequilibrium mapping of dichotomous diseases can be well applied to the mapping of quantitative-trait loci through the method of selective genotyping. In 1999, M. Slatkin considered a truncation selection (TS) approach. We propose in this report an extended TS approach and an extreme-rank-selection (ERS) approach. The properties of these selection approaches are studied analytically. By using a simulation study, we demonstrate that both the extended TS approach and the ERS approach provide remarkable improvements over Slatkin's original TS approach.     

中国木质林产品碳储量及其减排潜力

伐后木质林产品作为森林生态系统碳循环的一个组成部分,对森林生态系统和大气之间的碳平衡起着至关重要的作用.为准确合理估算木质林产品碳储量和我国参加气候变化谈判提供依据,在达喀尔会议上确立的3种估算方法框架下,即:储量变化法、生产法和大气流动法,利用寿命分析法和逐步递归法以及国内参数计算我国木质林产品的碳储量,且对生产法的应用提出了一种新假设思路,并分析我国木质林产品在替代建筑材料方面的减排潜力,结果显示:①分别利用储量变化法、生产法和大气流动法估算我国1961～2004年木质林产品的碳储量变化,证明我国的木质林产品是一个碳库,并且这个碳库的碳储量不断在增长;② 3种方法估算1961～2004年木质林产品碳储量的年平均增长量分别是11.73Mt · a-1(Mt=106t)、9.31Mt · a-1和7 90Mt · a-1;③木质林产品在建筑材料领域的替代作用以及延长其使用寿命使其减排潜力增大;④从碳储量计量和估算的难易程度来看,储量变化法的应用可能对我国较为有利;⑤针对生产法假设的实践应用,还需要进一步的研究.     

Chest wall resection and reconstruction: a true thoracoscopic approach

We set out to perform resection of a chest wall mass with subsequent reconstruction using a pure thoracoscopic approach. Using video-assisted thoracic surgery via a three-incision approach, we successfully removed an 8.5 × 3.5-cm specimen en bloc. We then reconstructed the chest wall with 2-mm polytetrafluoroethylene. A total thoracoscopic approach to chest wall resection and reconstruction represent an additional option in this area of thoracic surgery. This approach avoids some of the drawbacks of more invasive procedures. This report outlines a totally thoracoscopic approach that we feel represents a safe and viable option for patients requiring chest wall resection and reconstruction.     

Translational synthetic biology

Synthetic biology is a recent scientific approach towards engineering biological systems from both pre-existing and novel parts. The aim is to introduce computational aided design approach in biology leading to rapid delivery of useful applications. Though the term reprogramming has been frequently used in the synthetic biology community, currently the technological sophistication only allows for a probabilistic approach instead of a precise engineering approach. Recently, several human health applications have emerged that suggest increased usage of synthetic biology approach in developing novel drugs. This mini review discusses recent translational developments in the field and tries to identify some of the upcoming future developments.