Involvement of the endocannabinoid system in reward processing in the human brain

Rationale Disturbed reward processing in humans has been associated with a number of disorders, such as depression, addiction, and attention-deficit hyperactivity disorder. The endocannabinoid (eCB) system has been implicated in reward processing in animals, but in humans, the relation between eCB functioning and reward is less clear. Objectives The current study uses functional magnetic resonance imaging (fMRI) to investigate the role of the eCB system in reward processing in humans by examining the effect of the eCB agonist Δ9-tetrahydrocannabinol (THC) on reward-related brain activity. Methods Eleven healthy males participated in a randomized placebo-controlled pharmacological fMRI study with administration of THC to challenge the eCB system. We compared anticipatory and feedback-related brain activity after placebo and THC, using a monetary incentive delay task. In this task, subjects are notified before each trial whether a correct response is rewarded (“reward trial”) or not (“neutral trial”). Results Subjects showed faster reaction times during reward trials compared to neutral trials, and this effect was not altered by THC. THC induced a widespread attenuation of the brain response to feedback in reward trials but not in neutral trials. Anticipatory brain activity was not affected. Conclusions These results suggest a role for the eCB system in the appreciation of rewards. The involvement of the eCB system in feedback processing may be relevant for disorders in which appreciation of natural rewards may be affected such as addiction

'Issues of equity are also issues of rights': Lessons from experiences in Southern Africa

BACKGROUND: Human rights approaches to health have been criticized as antithetical to equity, principally because they are seen to prioritise rights of individuals at the expense of the interests of groups, a core tenet of public health. The objective of this study was to identify how human rights approaches can promote health equity. METHODS: The Network on Equity in Health in Southern Africa undertook an exploration of three regional case studies – antiretroviral access, patient rights charters and civic organization for health. A combination of archival reviews and stakeholder interviews were complemented with a literature review to provide a theoretical framework for the empirical evidence. RESULTS: Critical success factors for equity are the importance of rights approaches addressing the full spectrum from civil and political, through to socio-economic rights, as well as the need to locate rights in a group context. Human rights approaches succeed in achieving health equity when coupled with community engagement in ways that reinforce community capacity, particularly when strengthening the collective agency of its most vulnerable groups. Additionally, human rights approaches provide opportunities for mobilising resources outside the health sector, and must aim to address the public-private divide at local, national and international levels. CONCLUSION: Where it is clear that rights approaches are predicated upon understanding the need to prioritize vulnerable groups and where the way rights are operationalised recognizes the role of agency on the part of those most affected in realising their socio-economic rights, human rights approaches appear to offer powerful tools to support social justice and health equity

Identification and Structural Characterization of a New Three-Finger Toxin Hemachatoxin from Hemachatus haemachatus Venom

10.1371/journal.pone.0048112PLoS ONE710

Climate Change, Coral Reef Ecosystems, and Management Options for Marine Protected Areas

Marine protected areas (MPAs) provide place-based management of marine ecosystems through various degrees and types of protective actions. Habitats such as coral reefs are especially susceptible to degradation resulting from climate change, as evidenced by mass bleaching events over the past two decades. Marine ecosystems are being altered by direct effects of climate change including ocean warming, ocean acidification, rising sea level, changing circulation patterns, increasing severity of storms, and changing freshwater influxes. As impacts of climate change strengthen they may exacerbate effects of existing stressors and require new or modified management approaches; MPA networks are generally accepted as an improvement over individual MPAs to address multiple threats to the marine environment. While MPA networks are considered a potentially effective management approach for conserving marine biodiversity, they should be established in conjunction with other management strategies, such as fisheries regulations and reductions of nutrients and other forms of land-based pollution. Information about interactions between climate change and more “traditional” stressors is limited. MPA managers are faced with high levels of uncertainty about likely outcomes of management actions because climate change impacts have strong interactions with existing stressors, such as land-based sources of pollution, overfishing and destructive fishing practices, invasive species, and diseases. Management options include ameliorating existing stressors, protecting potentially resilient areas, developing networks of MPAs, and integrating climate change into MPA planning, management, and evaluation

HIV Seroprevalence across the Rural/ Urban Continuum

While the first decade of the AIDS epidemic was characterized by high prevalence rates of AIDS infection in urban areas, there is increasing recognition of the spread of HIV into rural communities in the United States. Data from the Miami CARES cohort collected on 3,555 chronic drug users from 1988 to 1994 provide a unique opportunity to assess sociodemographic characteristics, drug-using behaviors and HIV risk behaviors related to HIV seropositivity in three communities across the rural-urban continuum: Miami, Florida; Belle Glade, Florida and Immokalee, Florida. The three very different communities studied demonstrate that HIV is no respecter of ecological site. The spread of HIV between areas and within areas is specifically correlated with the risk factors including injection drug use, use of crack cocaine, exchange of sex for money, and the rates for sexually transmitted diseases. All of these factors are shown to increase the risk of HIV so that the constellation of these practices helps determine the differential rates and spread of HIV in the three different areas. [Translations are provided in the International Abstracts Section of this issue.

Behavior Changes among Crack-Using Rural and Urban Women

This study compared rural and urban crack-using women and examined their responses to two interventions. A prospective cohort study design was employed to assess the effectiveness of standard and innovative HIV prevention interventions on 541 urban and 268 rural women in Florida. Generalized estimating equation analysis, accounting for repeated measures, found that for combined urban and rural samples, the innovative intervention was more effective than the standard for a number of drug and sexual risk behaviors. However, the analysis indicated no significant differences in intervention efficacy between rural and urban women. The results imply that there is a need for similar HIV prevention services in both areas. [Translations are provided in the International Abstracts Section of this issue.