Low-Level Prenatal and Postnatal Blood Lead Exposure and Adrenocortical Responses to Acute Stress in Children

BACKGROUND: A few recent studies have demonstrated heightened hypothalamic–pituitary–adrenal (HPA) axis reactivity to acute stress in animals exposed to heavy metal contaminants, particularly lead. However, Pb-induced dysregulation of the HPA axis has not yet been studied in humans. OBJECTIVE: In this study, we examined children’s cortisol response to acute stress (the glucocorticoid product of HPA activation) in relation to low-level prenatal and postnatal Pb exposure. METHODS: Children’s prenatal blood Pb levels were determined from cord blood specimens, and postnatal lead levels were abstracted from pediatrician and state records. Children’s adrenocortical responses to an acute stressor were measured using assays of salivary cortisol before and after administration of a standard cold pressor task. RESULTS: Pb exposure was not associated with initial salivary cortisol levels. After an acute stressor, however, increasing prenatal and postnatal blood Pb levels were independently associated with significantly heightened salivary cortisol responses. CONCLUSIONS: Our results suggest that relatively low prenatal and postnatal blood lead levels— notably those below the 10 µg/dL blood lead level identified by the Centers for Disease Control and Prevention for public health purposes—can alter children’s adrenocortical responses to acute stress. The behavioral and health consequences of this Pb-induced HPA dysregulation in children have yet to be determined

Women, know your limits: Cultural sexism in academia

Despite the considerable advances of the feminist movement across Western societies, in Universities women are less likely to be promoted, or paid as much as their male colleagues, or even get jobs in the first place. One way in which we can start to reflect on why this might be the case is through hearing the experiences of women academics themselves. Using feminist methodology, this article attempts to unpack and explore just some examples of ‘cultural sexism’ which characterise the working lives of many women in British academia.This article uses qualitative methods to describe and make sense of just some of those experiences. In so doing, the argument is also made that the activity of academia is profoundly gendered and this explicit acknowledgement may contribute to our understanding of the under-representation of women in senior positions

Self-interest And Public Interest: The Motivations Of Political Actors

Self-Interest and Public Interest in Western Politics showed that the public, politicians, and bureaucrats are often public spirited. But this does not invalidate public-choice theory. Public-choice theory is an ideal type, not a claim that self-interest explains all political behavior. Instead, public-choice theory is useful in creating rules and institutions that guard against the worst case, which would be universal self-interestedness in politics. In contrast, the public-interest hypothesis is neither a comprehensive explanation of political behavior nor a sound basis for institutional design

Evidence for a regulatory role of CTP : Choline phosphate cytidylyltransferase in the synthesis of phosphatidylcholine in fetal lung following premature birth

The sequence of reactions which function to incorporate choline into phosphatidylcholine was investigated in lung from fetuses following premature delivery. The rate of [methyl-14C]choline incorporation by rat lung slices into phosphatidylcholine increases following premature delivery at both 20 and 21 days gestation. The increase in choline incorporation is primarily due to an increased specific activity of phosphorylcholine resulting from a decreased pool size of phosphorylcholine. The decrease in the concentration of phosphorylcholine following premature delivery is apparently caused by an increased activity of cytidylyltransferase which leads to an increase in the conversion of phosphorylcholine to phosphatidylcholine. The total activity of choline kinase, cytidylyltransferase, cholinephosphotransferase and phosphatidate phosphohydrolase did not change significantly. However, the cytidylyltransferase activity in the microsome fraction increased following premature delivery at 20 and 21 days gestation. The amount of cytidylyltransferase in the H form in the cytosol fraction increased following premature delivery at 21 days gestation but not at 20 days gestation. The results are interpreted to indicate that the active form of cytidylyltransferase in lung cells is the membrane-bound enzyme and this form increases following birth resulting in an increased synthesis of phosphatidylcholine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24304/1/0000570.pd

Elevated Salivary Alpha Amylase in Adolescent Sexual Abuse Survivors with Posttraumatic Stress Disorder Symptoms

Objective: Little is known regarding neuroendocrine responses in adolescent girls with posttraumatic stress disorder (PTSD) who have experienced sexual abuse. Therefore, we collected saliva samples three times daily for 3 days to assess concentrations of salivary alpha amylase (sAA) – a surrogate marker for autonomic nervous system (ANS) activity and, in particular, sympathetic activity – in sexually abused adolescent girls

Investigation of the deposition and emission of mercury in arctic snow during an atmospheric mercury depletion event

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94701/1/jgrd14741.pd

Competing biosecurity and risk rationalities in the Chittagong poultry commodity chain, Bangladesh

This paper anthropologically explores how key actors in the Chittagong live bird trading network perceive biosecurity and risk in relation to avian influenza between production sites, market maker scenes and outlets. They pay attention to the past and the present, rather than the future, downplaying the need for strict risk management, as outbreaks have not been reported frequently for a number of years. This is analysed as ‘temporalities of risk perception regarding biosecurity’, through Black Swan theory, the idea that unexpected events with major effects are often inappropriately rationalized (Taleb in The Black Swan. The impact of the highly improbable, Random House, New York, 2007). This incorporates a sociocultural perspective on risk, emphasizing the contexts in which risk is understood, lived, embodied and experienced. Their risk calculation is explained in terms of social consent, practical intelligibility and convergence of constraints and motivation. The pragmatic and practical orientation towards risk stands in contrast to how risk is calculated in the avian influenza preparedness paradigm. It is argued that disease risk on the ground has become a normalized part of everyday business, as implied in Black Swan theory. Risk which is calculated retrospectively is unlikely to encourage investment in biosecurity and, thereby, points to the danger of unpredictable outlier events

A synthesis of atmospheric mercury depletion event chemistry in the atmosphere and snow

It was discovered in 1995 that, during the spring time, unexpectedly low concentrations of gaseous elemental mercury (GEM) occurred in the Arctic air. This was surprising for a pollutant known to have a long residence time in the atmosphere; however conditions appeared to exist in the Arctic that promoted this depletion of mercury (Hg). This phenomenon is termed atmospheric mercury depletion events (AMDEs) and its discovery has revolutionized our understanding of the cycling of Hg in Polar Regions while stimulating a significant amount of research to understand its impact to this fragile ecosystem. Shortly after the discovery was made in Canada, AMDEs were confirmed to occur throughout the Arctic, sub-Artic and Antarctic coasts. It is now known that, through a series of photochemically initiated reactions involving halogens, GEM is converted to a more reactive species and is subsequently associated to particles in the air and/or deposited to the polar environment. AMDEs are a means by which Hg is transferred from the atmosphere to the environment that was previously unknown. In this article we review Hg research taken place in Polar Regions pertaining to AMDEs, the methods used to collect Hg in different environmental media, research results of the current understanding of AMDEs from field, laboratory and modeling work, how Hg cycles around the environment after AMDEs, gaps in our current knowledge and the future impacts that AMDEs may have on polar environments. The research presented has shown that while considerable improvements in methodology to measure Hg have been made but the main limitation remains knowing the speciation of Hg in the various media. The processes that drive AMDEs and how they occur are discussed. As well, the role that the snow pack and the sea ice play in the cycling of Hg is presented. It has been found that deposition of Hg from AMDEs occurs at marine coasts and not far inland and that a fraction of the deposited Hg does not remain in the same form in the snow. Kinetic studies undertaken have demonstrated that bromine is the major oxidant depleting Hg in the atmosphere. Modeling results demonstrate that there is a significant deposition of Hg to Polar Regions as a result of AMDEs. Models have also shown that Hg is readily transported to the Arctic from source regions, at times during springtime when this environment is actively transforming Hg from the atmosphere to the snow and ice surfaces. The presence of significant amounts of methyl Hg in snow in the Arctic surrounding AMDEs is important because this species is the link between the environment and impacts to wildlife and humans. Further, much work on methylation and demethylation processes has occurred but these processes are not yet fully understood. Recent changes in the climate and sea ice cover in Polar Regions are likely to have strong effects on the cycling of Hg in this environment; however more research is needed to understand Hg processes in order to formulate meaningful predictions of these changes