Factor structure of the transformational leadership model in human service teams

The purpose of this study was to examine the factor structure of the transformational leadership model in human service teams. As the nature of this work environment mandates certain management‐by‐exception practices, patterns of correlations between perceptions of active and passive management‐by‐exception behaviors and transformational, transactional, and laissez‐faire leadership were of interest. 236 leaders and 620 subordinates from 54 mental health teams completed the Multifactor Leadership Questionnaire, form 8Y. Results suggest that active and passive management‐by‐exception factors are independent constructs. Copyright © 2003 John Wiley & Sons, Ltd.     

Hematology and Some Biochemical Parameters of Wild Rodents in Pistachio Gardens of Kerman Province, Southeast Iran

Wild rodents were collected using live snap traps in pistachio gardens of Kerman Province, Southeast Iran from 2007 to 2009, then some physiological parameters of them were measured. The samples were identified as follow: Nesokia indica, Meriones persicus, Meriones lybicus and Tatera indica. Blood samples were obtained from the heart, then the blood parameters (glucose, cholesterol, triglyceride, total protein, HDL, red and white blood cell number) in wild species of rodents and laboratory rat were compared. The results showed that there were no significant differences in serum glucose, triglyceride, HDL and total protein levels among different experimental groups. The concentration of cholesterol in T. indica was more than that in N. indica (P < 0.01). The total numbers of red blood cells also showed significant difference between wild garden rodent species and laboratory rat (P < 0.01), while the numbers of white blood cells showed no significant difference.     

A Simulation Framework for Assessing Physical and Wildlife Impacts of Oil and Gas Development Scenarios in Southwestern Wyoming

Foreseeable natural gas development in southwestern Wyoming has the potential to increase sagebrush fragmentation and risks to resident wildlife species. The ability to balance future development with conservation goals, however, is enhanced by advances in directional-drilling technologies that use multiple wells per pad and produce less surface disturbance than conventional drilling methods. To evaluate the conservation potential of this technology, I developed an energy footprint model that simulates well, pad, and road patterns for oil and gas recovery options that vary in well types (vertical and directional) and number of wells per pad and use simulation results to quantify physical and wildlife-habitat impacts. I applied the model to assess tradeoffs among 10 conventional and directional-drilling scenarios in a natural gas field in southwestern Wyoming. Scenarios spanned a gradient in the number of vertical and directional wells, and in number of pads (2000 to 250), but all extracted the same amount of gas over a 15-year period. Reducing pad numbers with directional-drilling technology reduced surface disturbance area and impacts on spatially extensive habitats (48–96% of study area) such as sagebrush-obligate songbird habitat, elk winter range, and sagebrush core area. Impacts declined for spatially restricted mule deer migration corridors (24% of study area) and greater sage-grouse leks until energy infrastructure densities within corridors and near leks were similar to the initial landscape. Scenario simulations and tradeoff assessments such as illustrated in this study are intended to help decision-makers identify development designs that best achieve both energy and conservation goals.     

Nuclear events during early development in gametophytes of Macrocystis pyrifera,and the temporal effects of a marine contaminant

The time course of DNA synthesis in developing haploid gametophytes of the giant kelp Macrocystis pyrifera was determined, and the effects of arsenic (As) on the temporally distinct nuclear events, DNA synthesis and subsequent nuclear division/translocation, were investigated to establish which of these specific events may be disrupted by this contaminant. Experiments were carried out on material collected from kelp beds near Santa Barbara, California from 1993–1994. Timing of DNA synthesis was determined during development by use of the fluorochrome, DAPI (4,6-diamidino-2-phenylindole), and single-cell microspectrofluorometry. Zoospores, which result from meiosis, had already undergone two rounds of DNA synthesis at the time of release. The developing gametophytes underwent an additional two rounds of replication of DNA by 16 h of development, and following the first nuclear division/translocation, the gametophyte contained eight times the minimum DNA level throughout subsequent development. Both DNA synthesis and nuclear division/translocation, were found to be inhibited by As. Phosphate enrichment reduced the inhibitory effects of As on division/translocation of the nucleus, supporting the hypothesis that As interferes with phosphorylation. Gametophytes were more severely affected by As under light conditions, as opposed to dark, suggesting that photosynthesis may be more sensitive than dark metabolism.     

Kinetics of chromate adsorption on goethite in the presence of sorbed silicic acid

The adsorption of chromate on mineral surfaces has received much attention due to its toxicity in natural systems. Spectroscopic studies have demonstrated that chromate forms inner-sphere complexes on variable-charge surfaces. However, in natural systems chromate has been observed to be fairly mobile, which has been explained by the presence of naturally occurring ligands competing with chromate for mineral surface sites. Silicic acid is a ubiquitous ligand in soil and water environments and also sorbs strongly to variable-charge surfaces. Yet little research has examined its influence on chromate adsorption to variable-charge surfaces such as goethite. This study examined the influence of silicic acid (0.10 and 1.0 mM) on the adsorption kinetics of chromate (0.05 and 0.10 mM) on goethite over a range of common soil pH values (4, 6, and 8). The rate and total quantity of chromate adsorption decreased in all the experiments except at a pH value of 4 and a chromate concentration of 0.05 mM. The inhibition of chromate adsorption ranged from 3.1% (pH = 4, Si = 0.10 mM, chromate = 0.10 mM) to 83.3% (pH = 8, Si = 1.0 mM, chromate = 0.05 mM). The rate of chromate adsorption decreased with an increase in pH and silicic acid concentration. This was attributed to a reduction in the surface potential of goethite on silicic acid adsorption as well as a competition for surface sites. The presence of naturally occurring ligands such as silicic acid may be responsible for the enhanced mobility of chromate in natural systems and demonstrates the importance of competitive adsorption for evaluating the mobility of trace elements.     

An introduction to digital methods in remote sensing of forested ecosystems: Focus on the Pacific Northwest,USA

Aerial photography has been routinely used for several decades by natural resource scientists and managers to map and monitor the condition of forested landscapes. Recently, along with the emergence of concepts in managing forests as ecosystems, has come a significant shift in emphasis from smaller to larger spatial scales and the widespread use of geographic information systems. These developments have precipitated an increasing need for vegetation information derived from other remote sensing imagery, especially digital data acquired from high-elevation aircraft and satellite platforms. This paper introduces fundamental concepts in digital remote sensing and describes numerous applications of the technology. The intent is to provide a balanced, nontechnical view, discussing the shortcomings, successes, and future potential for digital remote sensing of forested ecosystems.     

水环境中镍毒性的机制研究：有害结局路径(AOP)分析

目前对镍(Ni)生态风险评估和水质法规采用了基于机制的预测工具,如生物配体模型(BLMs)。然而,尽管有许多具体细致的研究,Ni对水生生物毒性的精确机制仍然难以确定。对Ni行为机制的不确定性导致了大家在一些管理设置中应用像BLM这样的工具时,有所顾虑。为了解决这一认知差距,作者使用了有害结局路径(AOP)分析,也是第一个用于金属的AOP分析,来确定Ni毒性的多种潜在机制以及它们与淡水水生生物的相互作用。在金属的分子起始事件(molecular initiating events)在分类群中可能存在的前提下,在许多不同种水生和陆生生物数据的基础上,考虑建立一种潜在的行为机制。通过分析,作者识别了Ni可能对水生生物产生毒性的5个潜在的分子起始事件：Ca²⁺体内平衡的破坏,Mg²⁺体内平衡的破坏,Fe²⁺/³⁺体内平衡的破坏,活性氧类物质引起的氧化损伤,以及呼吸上皮细胞的过敏反应。在生物组织的器官水平,这5个潜在的分子起始事件会分解成3个可能的途径：支持外骨骼、外壳和骨骼生长的Ca²⁺减少;呼吸受损;细胞毒性和肿瘤形成。在整个生物体的水平,器官水平的反应将可能导致生长、繁殖的降低和/或能量代谢的改变,并且在每个通路之间有几个潜在的反馈回路。总体来说,目前的AOP分析可指导Ni的毒性机制研究,并为其他金属开发AOPs提供了有效的参考。
精选自Brix, K. V., Schlekat, C. E. and Garman, E. R. (2017), The mechanisms of nickel toxicity in aquatic environments: An adverse outcome pathway analysis. Environmental Toxicology and Chemistry, 36: 1128–1137. doi: 10.1002/etc.3706
详情请见http://onlinelibrary.wiley.com/wol1/doi/10.1002/etc.3706/full