206 research outputs found
A systematic review of local vulnerability to climate change: in search of transparency, coherence and comparability
Because vulnerability is a conceptual construct rather than a directly observable phenomenon,
most vulnerability assessments measure a set of “vulnerability indicators”. In order to identify
the core approaches and range of variation in the field, we conducted a systematic literature
review on local vulnerability to climate change. The systematic review entailed an
identification of frameworks, concepts, and operationalizations and a transparency assessment
of their reporting. Three fully defined relevant frameworks of vulnerability were identified:
IPCC, Patterns of Smallholder Vulnerability and Vulnerability as Expected Poverty.
Comparative analysis found substantial heterogeneity in frameworks, concepts and
operationalizations, making it impossible to identify patterns of climate vulnerability
indicators and determinants that have robust empirical support. If research measuring farmers’
vulnerability to climate change is to have any comparability, it needs greater conceptual
coherence and empirical validity. We recommend a systematic program of testing and
validating vulnerability measures before institutionalizing them in programmatic contexts
Modulation of SK Channel Trafficking by Beta Adrenoceptors Enhances Excitatory Synaptic Transmission and Plasticity in the Amygdala
Emotionally arousing events are particularly well remembered. This effect is known to result from the release of stress hormones and activation of beta adrenoceptors in the amygdala. However, the underlying cellular mechanisms are not understood. Small conductance calcium-activated potassium (SK) channels are present at glutamatergic synapses where they limit synaptic transmission and plasticity. Here, we show that beta adrenoceptor activation regulates synaptic SK channels in lateral amygdala pyramidal neurons, through activation of protein kinase A. We show that SK channels are constitutively recycled from the postsynaptic membrane and that activation of beta adrenoceptors removes SK channels from excitatory synapses. This results in enhanced synaptic transmission and plasticity. Our findings demonstrate a novel mechanism by which beta adrenoceptors control synaptic transmission and plasticity, through regulation of SK channel trafficking, and suggest that modulation of synaptic SK channels may contribute to beta adrenoceptor-mediated potentiation of emotional memories
α2-adrenoceptor-mediated inhibition in the central amygdala blocks fear-conditioning
The central amygdala is critical for the acquisition and expression of fear memories. This region receives a dense innervation from brainstem noradrenergic cell groups and has a high level of α2-adrenoceptor expression. Using whole-cell electrophysiological recordings from rat brain slices, we characterise the role of pre-synaptic α2-adrenoceptor in modulating discrete inhibitory and excitatory connections within both the lateral and medial division of the central amygdala. The selective α2-adrenoceptor agonist clonidine blocked the excitatory input from the pontine parabrachial neurons onto neurons of the lateral central amygdala. In addition, clonidine blocked inhibitory connections from the medial paracapsular intercalated cell mass onto both lateral and medial central amygdala neurons. To examine the behavioural consequence of α2-adrenoceptor-mediated inhibition of these inputs, we infused clonidine into the central amygdala prior to contextual fear-conditioning. In contrast to vehicle-infused rats, clonidine-infused animals displayed reduced levels of freezing 24 hours after training, despite showing no difference in freezing during the training session. These results reveal a role for α2-adrenoceptors within the central amygdala in the modulation of synaptic transmission and the formation of fear-memories. In addition, they provide further evidence for a role of the central amygdala in fear-memory formation
An Evaluation of Food Insecurity & Health Behavior among Rural Community Supported Agriculture (CSA) Participants
Introduction. Access to healthy foods is a major barrier for individuals achieving a healthy diet. The literature reveals several investigations into causes of food insecurity, but few focus on Community Supported Agriculture (CSA) programs that attempt to address food insecurity and related health behaviors of participants.https://scholarworks.uvm.edu/comphp_gallery/1199/thumbnail.jp
Association Between Chronic Hepatitis C Virus Infection and Myocardial Infarction Among People Living With HIV in the United States.
Hepatitis C virus (HCV) infection is common among people living with human immunodeficiency virus (PLWH). Extrahepatic manifestations of HCV, including myocardial infarction (MI), are a topic of active research. MI is classified into types, predominantly atheroembolic type 1 MI (T1MI) and supply-demand mismatch type 2 MI (T2MI). We examined the association between HCV and MI among patients in the Centers for AIDS Research (CFAR) Network of Integrated Clinical Systems, a US multicenter clinical cohort of PLWH. MIs were centrally adjudicated and categorized by type using the Third Universal Definition of Myocardial Infarction. We estimated the association between chronic HCV (RNA+) and time to MI while adjusting for demographic characteristics, cardiovascular risk factors, clinical characteristics, and history of injecting drug use. Among 23,407 PLWH aged ≥18 years, there were 336 T1MIs and 330 T2MIs during a median of 4.7 years of follow-up between 1998 and 2016. HCV was associated with a 46% greater risk of T2MI (adjusted hazard ratio (aHR) = 1.46, 95% confidence interval (CI): 1.09, 1.97) but not T1MI (aHR = 0.87, 95% CI: 0.58, 1.29). In an exploratory cause-specific analysis of T2MI, HCV was associated with a 2-fold greater risk of T2MI attributed to sepsis (aHR = 2.01, 95% CI: 1.25, 3.24). Extrahepatic manifestations of HCV in this high-risk population are an important area for continued research
Strengthening the food systems governance evidence base: Supporting commensurability of research through a systematic review of methods
Governance of food systems is a poorly understood determinant of food security.
Much scholarship on food systems governance is non-empirical, while existing
research is often case study-based and theoretically and methodologically
incommensurable. This frustrates aggregation of evidence and generalisation. We
undertook a systematic review of methods used in food systems governance research
with a view to identifying a core set of indicators for future research. We gathered
literature through a structured consultation and sampling from recent reviews.
Indicators were identified and classified according to the levels and sectors they
investigate. We found a concentration of indicators in food production at local to
national levels and a sparseness in distribution and consumption. Unsurprisingly,
many indicators of institutional structure were found, while agency-related indicators
are moderately represented. We call for piloting and validation of these indicators and
for methodological development to fill gaps identified. These efforts are expected to
support a more consolidated future evidence base and eventual meta-analysis
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