Metabolic discrimination between cholesterol and β-amyrin byPhytophthora cactorum

When cultures ofPhytophthora cactorum were incubated on solid medium for 3 weeks in the dark at 20 C with [¹⁴C] cholesterol or [¹⁴C]β-amyrin, the [¹⁴C] cholesterol was assimilated into the advancing mycelium to a greater extent than the [¹⁴C]β-amyrin. Examination of the mycelium and medium for radioactive metabolites showed significant differences in the metabolism of the 2 labeled compounds. Cholesterol was converted mainly to esters and to some extent to glycosides, whereas β-amyrin was only slightly converted to esters and not at all to glycosides. Presented at the International Symposium on “Phytophthora, Its Biology, Ecology, and Physiology,” at the University of California, Riverside, CA, April 1–4, 1981.     

中国部分医院患者体验和满意监测工具应用比较分析

目的:患者体验和满意调查已被认为是收集患者对医疗服务的评价信息和促进医疗服务质量改善的重要方法,2005年至2009年,北京和广西共50余家医院使用本土化的澳大利亚维多利亚州患者满意度监测工具(victorian patient satisfaction monitoring,VPSM)进行了满意度测量,比较分析当前本土化VPSM在我国医院应用情况,为其进一步应用提供参考建议.方法:采用文献研究方法,收集2005年至2009年以来公开或未公开发表的VPSM医院调查方案和监测报告,比较各次调查的操作过程和调查结果,分析优势与不足.结果:各次调查方法大致相同,但问卷结构、提醒感谢信发放、数据采集分析机构等略有差异;调查结果的稳定性和医院间可比性较好,但结果报告形式不够统一,总体上调查逐渐规范.长期监测能够发现医院服务质量的变化,对医院服务质量改进有参考意义.结论:各次调查验证了本土化VPSM工具的优势特点,但仍存在问题,有待进一步本土化和扩大调查范围.     

An Investigation of the Presence and Development of Social Capital in an Electrical Engineering Laboratory

Social capital consists of resources embedded in social networks that are purposefully mobilized through personal interactions. This project examined the factors that affected the development of social capital in an electrical and computer engineering laboratory. Data were collected through participant observation over the course of a term, interviews with students, and a survey. Interview and observational data were analyzed to determine themes or patterns in behaviors and actions that indicated the presence of social capital and affected the development of social capital in this setting. The open‐ended nature of the laboratory assignments and the complexity of a learning tool called TekBot? required students to access information. The lack of relevant information from the teaching assistants, internet, and laboratory assignment handouts required students to mobilize information from each other to succeed. Multiple methods of data collection validate the result that specific factors encouraged the development of social capital in this laboratory.     

DISTRIBUTION AND ABUNDANCE OF STREAM FISHES IN RELATION TO BARRIERS: IMPLICATIONS FOR MONITORING STREAM RECOVERY AFTER BARRIER REMOVAL

Dams are ubiquitous in coastal regions and have altered stream habitats and the distribution and abundance of stream fishes in those habitats by disrupting hydrology, temperature regime and habitat connectivity. Dam removal is a common restoration tool, but often the response of the fish assemblage is not monitored rigorously. Sedgeunkedunk Stream, a small tributary to the Penobscot River (Maine, USA), has been the focus of a restoration effort that includes the removal of two low‐head dams. In this study, we quantified fish assemblage metrics along a longitudinal gradient in Sedgeunkedunk Stream and also in a nearby reference stream. By establishing pre‐removal baseline conditions and associated variability and the conditions and variability immediately following removal, we can characterize future changes in the system associated with dam removal. Over 2 years prior to dam removal, species richness and abundance in Sedgeunkedunk Stream were highest downstream of the lowest dam, lowest immediately upstream of that dam and intermediate farther upstream; patterns were similar in the reference stream. Although seasonal and annual variation in metrics within each site was substantial, the overall upstream‐to‐downstream pattern along the stream gradient was remarkably consistent prior to dam removal. Immediately after dam removal, we saw significant decreases in richness and abundance downstream of the former dam site and a corresponding increase in fish abundance upstream of the former dam site. No such changes occurred in reference sites. Our results show that by quantifying baseline conditions in a small stream before restoration, the effects of stream restoration efforts on fish assemblages can be monitored successfully. These data set the stage for the long‐term assessment of Sedgeunkedunk Stream and provide a simple methodology for assessment in other restoration projects. Copyright © 2011 John Wiley & Sons, Ltd.     

Occurrence,Treatment, and Toxicological Relevance of EDCs and Pharmaceuticals in Water

Over the past decade a great amount of interest has arisen regarding the occurrence and fate of trace organic contaminants in the aquatic environment. Of particular concern are human hormones and pharmaceuticals, many of which are ubiquitous contaminants in conventional municipal wastewater treatment plant effluents when measured with ng/L detection limits. As analytical procedures and bioassay techniques become more readily available and increasingly sensitive, new contaminants will be discovered. The presence or absence of any chemical in a wastewater effluent is essentially a function of analytical detection capability. This poses a unique challenge for drinking water treatment plants intent on the removal of organic contaminants, as complete removal is merely a reflection of reporting limits. The investigation described here sought to determine the occurrence, treatment, and human health relevance of a chemically diverse group of emerging contaminants.     

Recombinant Landscapes in the American City

How are urban actors, such as landscape designers, community groups, developers and local politicians, actively restructuring their environments to meet the challenges of the American city in the new global context? Grahame Shane outlines the approaches to landscape that have been emerging since the mid-20th century and are set to recombine urban assemblages whether they are located in historic city centres, postindustrial waterfronts or suburban sprawl. Copyright © 2007 John Wiley & Sons, Ltd.     

Rates of mass transfer to patch electrodes in disturbed flows using oxygen reduction under limiting current conditions

The cases of a sudden pipe expansion and a sudden pipe contraction are simulated within a flow loop-based test section designed to approximate disturbed conduit flow. Mass transfer rates to patch electrodes at selected positions within the test section have been measured using a limiting current methodology applied to oxygen reduction at copper in 3.5% wt./vol. NaCl. Using both large-scale polarisation linear sweep voltammetry and a potential step current transient technique with hydrodynamic steps, absolute and relative rates of oxygen mass transfer have been examined as a function of Reynolds number and location within the test section. The highest rates of oxygen transfer were observed both within the high velocity area of the test section and close to known regions of flow disturbance. Under the flow conditions used, patch electrode mass transfer relates to wall shear stress, which allowed areas of high mean and high fluctuating wall shear stress to be identified.     

Characteristics of Milk Powders Produced by Spray Freeze Drying

Skim and whole milk powders were manufactured at lab scale by spray freeze drying (SFD), using liquid nitrogen as the cryogen. The polydispersity of droplet/particle sizes was limited using an encapsulator nozzle to atomize the feed. Particle morphology was examined using a scanning electron microscope. Samples were compared with equivalent spray-dried powders in tests of wettability and dissolution in water. The spray freeze-dried powders were found to be highly porous, with a uniform structure of pores throughout the entire particles. When tested in water, SFD skim milk powders wetted roughly three times as fast as industrially spray-dried agglomerated skim milk powders and were observed to dissolve rapidly by breaking down into smaller particles.