Alterations in cell cholesterol content modulate Ca2+-induced tight junction assembly by MDCK cells

Transepithelial electrical resistance (TER), a measure of tight junction (TJ) barrier function, develops more rapidly and reaches higher values after preincubation of MDCK cells for 24 h with 2 μM Lovastatin (lova), an inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase. While this effect was attributed to a 30% fall in cholesterol (CH), possible effects of lova on the supply of prenyl group precursors could not be excluded. In the current study, strategies were devised to examine effects on TER of agents that simultaneously lower CH and increase the flux of intermediates through the CH biosynthetic pathway. Zaragozic acid, 20 μM, an inhibitor of squalene synthase known to increase the synthesis of isoprenoids and levels of prenylated proteins, lowered cell CH by 30% after 24 h, while accelerating development of TER in the same manner as lova. TER was also enhanced, despite a 23% increase in the rate of [³H]acetate incorporation into CH, when total CH was reduced by 45% during a 2-h incubation with 2 mM methyl β-cyclodextrin (MBCD), an agent that stimulates CH efflux from cells. The fact that the rate of TER development was diminished when cell CH content was elevated by incubation with a complex of CH and MBCD is further evidence that this sterol modulates development of the epithelial barrier. Cell associated CH derived from the complex was similar to endogenous CH with respect to its accessibility to cholesterol oxidase. Lova's effect on TER was diminished when 5 μg/mL of CH was added to the medium during the last 11 h of incubation with lova.     

Real-time biomechanical biofeedback effects on top-level rifle shooters

The aim was to examine the effects of training with real-time biomechanical biofeedback on technique and performance of rifle shooters. Top-level shooters were randomly assigned to biofeedback- (n = 5) and control- (n = 4) groups. Bi-weekly training of 20 shots air-rifle for 4 weeks, with pre- and post-tests of 20 shots air-rifle and smallbore, were performed. The biofeedback group received individualized real-time auditory biofeedback on postural- and barrel-stabilities. Results revealed a technique of reducing postural- and barrel-stabilities towards triggering (e.g. barrel speed 8.0 ± 1.2 mm/s at 3.0-1.0 s reducing to 5.4 ± 0.8 mm/s at 0.3-0.1 s). There were no changes pre- to post-tests and no differences between groups in these measures of stability. The biofeedback group showed meaningful improvements in performance measures, whereas the control group showed no improvement (e.g. smallbore shot group diameter change: biofeedback group -2.6 mm; control group 0.1 mm). Biomechanical biofeedback is proposed to have improved performance, possibly through training better decision making, but the actual cause requires further research.     

Computer-assisted motion analysis of neuronal cell growth

Characterization of neuronal cell growth provides key information about the development of neural pathways during embryogenesis as well as their regeneration following postnatal nerve injury. However, very active cell types like growing neurons are difficult to track in detail because their motion is complex and cellular features have a tendency to move out of the focal plane or occlude one another. Due to these difficulties, characterization of neuronal growth dynamics has been less quantitative than desired. To address this problem, we developed a method for the automated motion analysis of neuronal growth based on image analysis and shape correspondence techniques. This method increases the rate at which we can obtain dynamic data by at least an order of magnitude. We focus specifically on the growth cone, a specialized, cell-like structure at the growing neurite tip whose behavior is believed to be a key determinant of neuronal growth. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1413–1422, 1997     

Smokers and non-smokers talk about regulatory options in tobacco control

Objective

Community members are occasionally polled about tobacco control policies, but are rarely given opportunities to elaborate on their views. We examined laypeople''s conversations to understand how 11 regulatory options were supported or opposed in interactions.

Design

Qualitative design; purposive quota sampling; data collection via focus groups.

Setting

Three locations in Sydney, Australia.

Participants

63 smokers and 75 non‐smokers, men and women, from three age groups (18–24, 35–44, 55–64 years), recruited primarily via telephone.

Measurements

Semi‐structured question route; data managed in NVivo; responses compared between groups.

Results

Laypeople rejected some regulatory proposals and certain arguments about taxation and the cost of cessation treatments. Protecting children and hypothecating tobacco excise for health education and care were highly acceptable. Plain packaging, banning retail displays and youth smoking prevention received qualified support. Bans on political donations from tobacco corporations were popular in principle but considered logistically fraught. Smokers asked for better cessation assistance and were curious about cigarette ingredients. Justice was an important evaluative principle. Support was often conditional and unresolved arguments frequent. We present both sides of these conflicts and the ways in which policies were legitimised or de‐legitimised in conversation.

Conclusions

Simple measures of agreement used in polls may obscure the complexity of community responses to tobacco policy. Support was frequently present but contested; some arguments that seem self‐evident to advocates were not so to participants. The detailed understanding of laypeople''s responses provided through qualitative methods may help frame proposals and arguments to meet concerns about justice, effectiveness and feasibility.     

Antarctic research bases: local sources of polybrominated diphenyl ether (PBDE) flame retardants

Contemporary studies of chemical contamination in Antarctica commonly focus on remnants of historical local releases or long-range transport of legacy pollutants. To protect the continent's pristine status, the Antarctic Treaty's Protocol on Environmental Protection prohibits importation of persistent organic pollutants. However, some polybrominated diphenyl ether (PBDE) congeners exhibit similar properties. Many modern polymer-containing products, e.g., home/office furnishings and electronics, contain percent levels of flame retardant PBDEs. PBDE concentrations in indoor dust and wastewater sludge from the U.S. McMurdo and New Zealand-operated Scott Antarctic research bases were high. Levels tracked those in sludge and dust from their respective host countries. BDE-209, the major constituent in the commercial deca-PBDE product, was the dominant congener in sludge and dust, as well as aquatic sediments collected near the McMurdo wastewater outfall. The pattern and level of BDE-209 sediment concentrations, in conjunction with its limited environmental mobility, suggest inputs from local sources. PBDE concentrations in fish and invertebrates near the McMurdo outfall rivaled those in urbanized areas of North America and generally decreased with distance. The data indicate that reliance on wastewater maceration alone, as stipulated by the Protocol, may permit entry of substantial amounts of PBDEs and other chemicals to the Antarctic environment.     

锡膏检测--统筹协调各要素

现在有不计其数的文章和实例说明采用二维或三维锡膏检测工艺来控制印刷流程,排除或发现粘贴印刷中出现的错误具有很多优点。作为自动光学检测(AOI)和锡膏检测(SPI)领域的领导者,安捷伦科技公司可以证实大多数公司和人都赞同的一个事实,即当今的制造领域面对日益严峻的芯片规模包装(CSP)挑战,而且部件已经降到0201级,所以制订一定的测试方案非常必要。但是在设计锡膏检测使用模式中碰到的最大问题之一是:在设计一个强有力的生产流程并随后控制这个流程时,要考虑到每一个生产流程有自身的一套变量。在锡膏检测业中最常出现的问题是用户希望只使用一个规则或流程控制模式来建立一个成功的锡膏检测方案。锡膏检测使用模式不同于电子检测和其他过去失败的测试策略,它是一个为用户度身设计的检测战略,需要锡膏检测用户预先工作以建立最佳的流程控制方法。概述了一种可用于成功进行锡膏测试的方法论或思维过程。这一方法论将有助于发现锡膏使用模式,并推进锡膏检测方案合理而有效的实施。     

From the lab to the clinic: Effectiveness of cognitive-behavioral treatments for anxiety disorders.

A controversy exists over whether results of randomized controlled trials of psychological treatment methods generalize to routine clinical practice. To examine the generalizability of cognitive-behavioral interventions for anxiety disorders, a meta-analysis of 11 effectiveness studies was conducted. Only studies that closely approximated real-world clinical practice were included in the present meta-analysis (e.g., studies were conducted in a nonuniversity setting, practitioners had regular caseloads, clients were not excluded if they had comorbid conditions). Cognitive-behavioral interventions were associated with significant improvement in anxiety symptoms at the end of treatment (dw = 1.35) and again at follow-up (dw = 1.14). On the basis of these results, it seems that cognitive-behavioral interventions for anxiety disorders generalize to real-world clinical practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)