Environmental Risk Assessment of Dams by Using Multi-Criteria Decision-Making Methods: A Case Study of the Polrood Dam,Guilan Province,Iran

A dam's construction always imposes some risks to the environment. In this article, the environmental risks of the Polrood dam, located in a northern province of Iran, during its construction phase, were identified, ranked, and evaluated. The risk factors were initially identified by Delphi questionnaire and then rated using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Subsequently, the Analytical Hierarchy Process (AHP) was applied to classify the risk factors into four major categories, and Expert Choice software was used to weight them. Based on the obtained results, Physicochemical; Biological; Economic, Social, and Cultural; and Health and Safety risks were rated by the weights of 0.124, 0.080, 0.048, and 0.021, respectively. Among the physicochemical risks, Erosion and Sedimentation weighted 0.061 and 0.047, respectively, were identified as the most serious risks. Among the biological risks, the highest negative impact was assigned to Land Cover with the weight of 0.189. In the third category, the most important risk was Population Displacement, weighted 0.114. Workers’ Falls with the weight of 0.109 was also determined as the highest risk in the last category. A comprehensive risk response plan will be required for dealing with the identified risks and their mitigation.     

Modelling the impact of microbial grazers on soluble rhizodeposit turnover

Rhizodeposition represents a relatively large carbon flow from a plant’s root into the surrounding soil. This carbon flow may have important implications for nitrogen mineralisation and carbon sequestration, but is still poorly understood. In this paper we use a simple compartment model of carbon flow in the rhizosphere to investigate the proposed benefits of rhizodeposition and the effect of microbial grazers. Model parameters were fitted to published, experimental data. Analysis of the model showed that dead organic matter (necromass) had a much longer time-scale than the other carbon pools (soluble, microbial and grazer carbon), which allowed an approximate, mathematical solution of the model to be derived. This solution shows that the level of necromass in the soil is an important factor in many processes of interest. The short-term carbon and nitrogen turnover increases with the level of necromass. Microbial grazers decrease carbon turnover at high levels of necromass, whilst at lower, and possibly more realistic, levels of necromass grazers increase turnover. However, the largest effect of grazers was to increase carbon turnover by 10%, suggesting that grazers are relatively unimportant in larger scale models of soil organic matter turnover. The marginal benefits of rhizodeposition increase with the level of necromass. The model suggests that the short-term benefits of rhizodeposition to a plant are marginal, but long-term benefits may still occur.     

Social Dominance Hierarchies and Phenotypic Correlates of Dominance in Captive Groups of the Grey‐cheeked Fulvetta Alcippe morrisonia in Taiwan

Dominance hierarchies usually form quickly among avian foraging groups because they are beneficial to most individuals by reducing conflict. Several characteristics that correlate with dominance rank have been identified in birds, but most of these conclusions rely on studies of temperate species. Hence, we studied whether captive group members of a subtropical species, grey‐cheeked fulvetta Alcippe morrisonia, form social dominance hierarchies when competing for food during the non‐breeding season. We also investigated whether sex, age, body condition and fat score were related to an individual's dominance rank which was established by counting aggressive interactions in six captive groups of nine individuals each. In all groups, linear dominance hierarchies were formed whereby yearlings dominated over adult birds, and individuals with a better body condition were also more dominant, while sex and fat score had no discernable effect. Male yearlings had significantly higher body masses and body condition indices than male adults, while female yearlings had significantly higher body masses, body condition indices and fat scores than female adults. However, there were no significant differences between male and female yearlings or adults for any of these variables. We suggest possible reasons for the dominance of yearlings, such as captive conditions or the higher body weight of yearlings.     

贵阳市10种观赏草基于AHP方法的观赏适应性综合评价

从观赏草观赏性出发,结合与适应性和生长繁殖相关的11个指标,通过层次分析法(AHP)对贵阳市引进的10个观赏草品种进行观赏适应性综合评价。结果表明,11个评价指标中,观赏草的株型、叶色、耐旱性所占权重均较大(＞0.1),是影响其观赏适应性的重要指标;通过建立评分标准后,得出10个品种的观赏性排名为火焰狼尾草、花叶蒲苇、紫叶狼尾草、矮蒲苇、新西兰亚麻、金叶苔草、粉黛乱子草、蓝羊茅、红巨人朱蕉、黄金苔草;生长适应性排名为矮蒲苇、花叶蒲苇、火焰狼尾草、紫叶狼尾草、新西兰亚麻、黄金苔草、粉黛乱子草、金叶苔草、红巨人朱蕉、蓝羊茅;最终综合评分观赏适应价值极好的(Ⅰ级＞4.30分)有花叶蒲苇、火焰狼尾草;观赏适应价值较好的(Ⅱ级3.56～4.30分)有矮蒲苇、紫叶狼尾草、新西兰亚麻、粉黛乱子草、金叶苔草;观赏适应价值一般的(Ⅲ级＜3.56分)有蓝羊茅、红巨人朱蕉、黄金苔草。     

基于生境适宜性指数模型的俚岛海黍子生境层级分布

为了深入了解海黍子生境,利用模型对山东俚岛海黍子生境进行适宜性分析,分别选取温度、盐度、水深、浊度、底质、无机氮浓度、磷酸盐浓度和距海藻床距离8种环境因子,通过层次分析法赋值因子权重,结合空间分析方法建立了海黍子HSI模型。利用该模型对山东俚岛近岸海域2018年春、秋两季的环境因子调查结果进行了海黍子生境分析。结果表明: 研究区域内的海黍子海藻床区域主要由极佳生境和适宜生境组成,春季和秋季的分布面积分别占14.2%和18.6%。海黍子生境层级分布随季节而变化,且不同季节的生境层级具有一定的空间重合性。温度和磷酸盐浓度的适宜性变化具有明显的季节性差异,是导致俚岛海黍子HSI季节变化的主要原因。海黍子HSI模型不仅可用于检测海黍子海藻床区域的生境层级分布,还能发现海黍子潜在的适宜生境区域。这为今后开展海黍子资源保护和人工增殖工作提供了科学参考。     

The social position of multiracial groups in the United States: evidence from residential segregation

I use multiple perspectives on the racial order in the United States to generate hypotheses about the social position of mixed-race groups. Perspectives that view the racial order as binary, ternary with an undifferentiated middle, or ternary with a stratified middle present different expectations for the social position of multiracial groups. I use a group's level of residential segregation as an index of social position. In 2000, multiracial persons lived in neighbourhoods that were more white than the neighbourhoods of single-race minorities, though more diverse than the neighbourhoods of whites. Thus, multiracial groups appear to occupy an intermediate social position relative to blacks and whites, a finding that supports contemporary arguments about shifting colour-lines in the United States and the emergence of a triracial system of stratification. Yet, findings also suggest that the social space between blacks and whites is, itself, racially stratified.     

Aldehyde dehydrogenase activity selects for the holoclone phenotype in prostate cancer cells

Aldehyde dehydrogenase 1 (ALDH) activity is considered to be a marker of cancer stem cells (CSCs) in many tumour models, since these cells are more proliferative and tumourigenic than ALDH^Lo cells in experimental models. However it is unclear whether all CSC-like cells are within the ALDH^Hi population, or whether all ALDH^Hi cells are highly proliferative and tumourigenic. The ability to establish a stem cell hierarchy in vitro, whereby sub-populations of cells have differing proliferative and differentiation capacities, is an alternate indication of the presence of stem cell-like populations within cell lines. In this study, we have examined the interaction between ALDH status and the ability to establish a stem cell hierarchy in PC3 prostate cancer cells. We demonstrate that PC3 cells contain a stem cell hierarchy, and isolation of ALDH^Hi cells enriches for the most primitive holoclone population, however holoclone formation is not restricted to ALDH^Hi cells. In addition, we show that ALDH activity undergoes phenotypic plasticity, since the ALDH^Lo population can develop ALDH^Hi populations comparable to parental cells within 2 weeks in culture. Furthermore, we show that the majority of ALDH^Hi cells are found within the least primitive paraclone population, which is circumvented by culturing PC3 cells as spheroids in defined medium favouring stem cell characteristics. Although ALDH^Hi status enriches for holoclone formation, this activity may be mediated by a minority of ALDH^Hi cells.     

Ecological Discord and the Importance of Scale in Scientific Inquiry

Scale is widely recognized today as an important concept in ecology because the scale of investigation determines the patterns and processes that can be observed. Ecological investigations can produce different outcomes depending on the scale at which observations are made, and ecological disagreements have occurred simply because investigators addressed the same question using different scales. Here I draw on quail research to illustrate the importance of scale in ecological studies and how lack of scale consideration can lead to discord. I use northern bobwhite (Colinus virginianus) as the focal species and discuss 2 areas of investigation (woody-cover requirements and influence of rainfall) that are characterized by confusion and disagreement but where consideration of scale brings clarity. In the process, I discover 2 formerly unrecognized patterns: northern bobwhite use of woody cover is inversely related with spatial extent of observation, and the influence of rainfall on northern bobwhite abundance decreases with decreasing spatial extent. In both cases, consideration of scale clarifies muddled knowledge and creates a unified framework for management. Future ecological investigations should formulate research questions within a scale framework, provide an explicit statement of scale in methods, and interpret findings within a scale context to help advance wildlife science and management. © 2020 The Wildlife Society.