Modeling Cholinesterase Activity for Human Dietary Risk Assessment of Carbamate Insecticides

This article demonstrates statistical models to quantify the interaction between a carbamate insecticide and acetylcholinesterase. Carbamates are a class of chemicals that inhibit the activity of acetylcholinesterase in humans, an enzyme involved in the regulation of the neurotransmitter acetylcholine. Following exposure to a carbamate insecticide, we specifically address (1) if acetylcholinesterase activity recovers to its level of preexposure activity; (2) the level of inhibition of acetylcholinesterase activity; (3) the recovery time of acetylcholinesterase activity to its preexposure level for a typical individual; and (4) the upper percentiles of the recovery time of acetycholinesterase activity across individuals. A nonlinear mixed-effects model is fitted to data from a repeated measures experiment conducted with human volunteers randomly assigned to a control and four dose groups. Repeated measurements were taken prior to exposure and at 1, 2, 4, 6, 8, and 21 hours after exposure to the carbamate aldicarb. It was found that full recovery did occur. Inhibition at 1 hour was estimated with maximum inhibition most likely occurring prior to 1-hour postexposure. In addition, recovery was rapid even for sensitive individuals. Given this information, the potential effect from exposure to a carbamate consumed in the diet during a day can be quantitatively assessed.     

Eschew Obfuscation in Discussing Political Correctness

ABSTRACT

Despite the spectrum of available resources, homelessness is a persistent societal and public health challenge throughout the United States and in San Diego County. Beginning in January 2014, San Diego began the integration of a Coordinated Entry System into its homeless system-of-care. This historical prospective study examined the predictors of establishing eligibility for permanent housing resources among 15,042 single homeless adults enrolled in the Coordinated Entry System Multivariable logistic regression was conducted to assess the relationship between client vulnerability as measured by the triage tool VI-SPDAT and establishing client eligibility for permanent housing. Overall, being of moderate or high vulnerability was associated with establishing eligibility for a permanent housing resource. Veterans established eligibility faster and more frequently than others, regardless of their vulnerability score. However, the demand for services far outweighed the ability of the system to respond to those with moderate to high vulnerability. More housing navigators and fewer client “hand-offs” between housing professionals are recommended to increase the efficiency of the process. Additional research examining the second and third steps is also needed to more fully understand the factors that promote permanent housing solutions for those seeking services.     

Collectively seeing the wind: Distributed cognition in smokejumping

This paper examines a segment of the activity of smokejumping—the aerial deployment of forest fire fighters—for clues as to how cognition is distributed among the participants. Unlike the Cartesian paradigm in which actors are portrayed as individuals who send and receive messages, the collective nature of developing a shared vision of the environment is emphasized. A shared vision of the environment is vital to the success of the smokejumping activity. It is achieved here through both the use of common reference points in the environment and through historically constituted artifacts designed for the sharing of visions. Thus, human activity can be seen as a collective, historical process.     

Introduction

This essay contrasts two different modes of iconic appropriation and organizational symbolism, with reference to a single physical structure: on the one hand, that of a local folk society, seeking to define itself and preserve its distinctiveness as against the wider nation state of which it is a part; and, on the other hand, that of the nation-state itself, seeking to incorporate the diverse elements out of which it is constituted into a coherent synthesis. Both modes operate by selecting particular elements out of the material remains and recoding them within specific ideologies, although they go about their “symbolic work” in strikingly different ways, the one technologically passive and the other technologically proactive. Moreover, of these two appropriations, one (that of the nation) is hegemonic, in that it imposes itself and pre-empts the other. By reference to diverse historical examples, the discussion in the latter part of the paper attempts to elucidate the salient features of symbolic hegemony.     

将休闲游客纳入海洋保护区规划——以加拿大不列颠哥伦比亚地区的游艇研究为例

海洋保护区(MPAs)与海洋功能区划的社会目标和生态目标若要实现,必须得到利益相关方的理解。本文以游憩机会序列(ROS)和游憩冲突模型为基础,考察了加拿大不列颠哥伦比亚海洋保护区里面的游艇者。笔者在夏季对到访该地区的游艇者(n=543)进行了问卷调查。调查结果显示,游艇者对环境的偏好各异,证明应该以游憩机会序列为基础进行海洋保护区规划与海洋功能区划。站在游艇者这一群体的角度,他们最看重的是自然环境,帆船驾驶者比汽艇驾驶者更倾向于自然和安静的环境,而汽艇驾驶者则比帆船驾驶者更倾向于以建成设施和采掘活动为特征的环境。有些海洋活动则成为游艇者冲突的根源,包括私人船只、商业赏鲸船只以及贝类水产养殖。本文通过分析指出,有些冲突可以通过海洋功能区划解决,而另外一些最好是通过教育和沟通的方式。文末还针对海洋保护区的管理及未来的研究方向提出了建议。     

Race, Genetic Ancestry, and Health

Knowledge from human genetic research continuously challenges the notion that race and biology are inextricably linked, with implications across biomedical and public health disciplines. However, biomedical research continues to explore health and disease under a racial framework ignoring and at times confounding the identification of true biological and/or environmental risk factors. Within this article, we present a brief overview of the use of race in biomedical research and studies of human genome variation and how genetic ancestry may help us understand health disparities. We believe that the casual use of “race” to define groups in biomedical research has contributed to our limited understanding of complex disease etiology and risk factors driving health disparities.     

Tracking national and regional spatial-temporal mortality risk associated with NO2 concentrations in Canada: a Bayesian hierarchical two-level model

The association between daily variations in urban air quality and mortality has been well documented using time series statistical methods. This approach assumes a constant association over time. We develop a space-time dynamic model that relaxes this assumption, thus more directly examining the hypothesis that improvements in air quality translate into improvements in public health. We postulate a Bayesian hierarchical two-level model to estimate annual mortality risks at regional and national levels and to track both risk and heterogeneity of risk within and between regions over time. We illustrate our methods using daily nitrogen dioxide concentrations (NO2) and nonaccidental mortality data collected for 1984-2004 in 24 Canadian cities. Estimates of risk and heterogeneity are compared by cause of mortality (cardio-pulmonary [CP] versus non-CP) and season, respectively. Over the entire period, the NO2 risk for CP mortality was slightly lower but with a narrower credible interval than that for non-CP mortality, mainly due to an unusually low risk for a single year (1998). Warm season NO2 risk was higher than cold season risk for both CP and non-CP mortality. For 21 years overall there were no significant differences detected among the four regional NO2 risks. We found overall that there was no strong evidence for time trends in NO2 risk at national or regional levels. However, an increasing linear time trend in the annual between-region heterogeneities was detected, which suggests the differences in risk among the four regions are getting larger, and further studies are necessary to understand the increasing heterogeneity.     

The racial politics of STEM education in the USA: interrogations and explorations

ABSTRACT

This special issue brings together a mix of early-career, mid, and senior scholars to critically examine current realities of, and boldly imagine future possibilities for, STEM education in the lives of racially minoritized children in the United States. Given the implicit and sometimes explicit aspirations of STEM education to be a counteracting force against racialized injustice, how do students and communities of color experience and make sense of STEM reforms/initiatives? By examining a broad range of STEM contexts including mathematics, computer science, science and environmental science education, and through a diversity of methodological approaches, this special issue aims to contribute to a scholarly conversation about how racialized power intersects with the larger themes and foci of STEM education. In our introduction, we both highlight broad themes of the issue, and offer possible directions for future research at the intersections of race, power, and STEM.