3,749 research outputs found
Callous-Unemotional Traits and Fearlessness: A Cardiovascular Psychophysiological Perspective in Two Adolescent Samples using Virtual Reality
There has been a longstanding debate about the link between callous-unemotional traits and fearlessness. However, biological evidence for a relationship in adolescents is lacking. Using two adolescent samples, we measured emotional reactivity, and cardiac measures of sympathetic (pre-ejection period) and parasympathetic (respiratory sinus arrhythmia) reactivity during 3D TV and virtual reality fear induction. Study 1 included 62 community adolescents from a stratified sample. Study 2 included 60 adolescents from Emotional and Behavioral Difficulties schools. Results were consistent across both studies. Adolescents with high callous-unemotional traits showed coactivation of the sympathetic and parasympathetic nervous system. Consistent with these results, youths with callous-unemotional traits self-reported that they felt more in control after the fear induction. Thus, in both samples, youth with callous-unemotional traits displayed a physiological and emotional profile suggesting they maintained control during fear induction. Therefore, it is proposed here that a shift in thinking of youth with callous-unemotional traits as fearless to youth with callous-unemotional traits are better able to manage fearful situations, may be more appropriate
Encoding of tactile stimulus parameters by mechanosensory P cells of the medicinal leech Hirudo medicinalis
Bioturbator-stimulated loss of seagrass sediment carbon stocks
© 2018 Association for the Sciences of Limnology and Oceanography Seagrass ecosystems are highly productive, and are sites of significant carbon sequestration. Sediment-held carbon stocks can be many thousands of years old, and persist largely due to sediment anoxia and because microbial activity is decreasing with depth. However, the carbon sequestered in seagrass ecosystems may be susceptible to remineralization via the activity of bioturbating fauna. Microbial priming is a process whereby remineralization of sediment carbon (recalcitrant organic matter) is stimulated by disturbance, i.e., burial of a labile source of organic matter (seagrass). We investigated the hypothesis that bioturbation could mediate remineralization of sediment carbon stocks through burial of seagrass leaf detritus. We carried out a 2-month laboratory study to compare the remineralization (measured as CO 2 release) of buried seagrass leaves (Zostera muelleri) to the total rate of sediment organic matter remineralization in sediment with and without the common Australian bioturbating shrimp Trypaea australiensis (Decapoda: Axiidea). In control sediment containing seagrass but no bioturbators, we observed a negative microbial priming effect, whereby seagrass remineralization was favored over sediment remineralization (and thus preserving sediment stocks). Bioturbation treatments led to a two- to five-fold increase in total CO 2 release compared to controls. The estimated bioturbator-stimulated microbial priming effect was equivalent to 15% of the total daily sediment-derived CO 2 releases. We propose that these results indicate that bioturbation is a potential mechanism that converts these sediments from carbon sinks to sources through stimulation of priming-enhanced sediment carbon remineralization. We further hypothesized that significant changes to seagrass faunal communities may influence seagrass sediment carbon stocks
The microaerophilic microbiota of de-novo paediatric inflammatory bowel disease: the BISCUIT study
<p>Introduction: Children presenting for the first time with inflammatory bowel disease (IBD) offer a unique opportunity to study aetiological agents before the confounders of treatment. Microaerophilic bacteria can exploit the ecological niche of the intestinal epithelium; Helicobacter and Campylobacter are previously implicated in IBD pathogenesis. We set out to study these and other microaerophilic bacteria in de-novo paediatric IBD.</p>
<p>Patients and Methods: 100 children undergoing colonoscopy were recruited including 44 treatment naïve de-novo IBD patients and 42 with normal colons. Colonic biopsies were subjected to microaerophilic culture with Gram-negative isolates then identified by sequencing. Biopsies were also PCR screened for the specific microaerophilic bacterial groups: Helicobacteraceae, Campylobacteraceae and Sutterella wadsworthensis.</p>
<p>Results: 129 Gram-negative microaerophilic bacterial isolates were identified from 10 genera. The most frequently cultured was S. wadsworthensis (32 distinct isolates). Unusual Campylobacter were isolated from 8 subjects (including 3 C. concisus, 1 C. curvus, 1 C. lari, 1 C. rectus, 3 C. showae). No Helicobacter were cultured. When comparing IBD vs. normal colon control by PCR the prevalence figures were not significantly different (Helicobacter 11% vs. 12%, p = 1.00; Campylobacter 75% vs. 76%, p = 1.00; S. wadsworthensis 82% vs. 71%, p = 0.312).</p>
<p>Conclusions: This study offers a comprehensive overview of the microaerophilic microbiota of the paediatric colon including at IBD onset. Campylobacter appear to be surprisingly common, are not more strongly associated with IBD and can be isolated from around 8% of paediatric colonic biopsies. S. wadsworthensis appears to be a common commensal. Helicobacter species are relatively rare in the paediatric colon.</p>
Can we manage coastal ecosystems to sequester more blue carbon?
© The Ecological Society of America To promote the sequestration of blue carbon, resource managers rely on best-management practices that have historically included protecting and restoring vegetated coastal habitats (seagrasses, tidal marshes, and mangroves), but are now beginning to incorporate catchment-level approaches. Drawing upon knowledge from a broad range of environmental variables that influence blue carbon sequestration, including warming, carbon dioxide levels, water depth, nutrients, runoff, bioturbation, physical disturbances, and tidal exchange, we discuss three potential management strategies that hold promise for optimizing coastal blue carbon sequestration: (1) reducing anthropogenic nutrient inputs, (2) reinstating top-down control of bioturbator populations, and (3) restoring hydrology. By means of case studies, we explore how these three strategies can minimize blue carbon losses and maximize gains. A key research priority is to more accurately quantify the impacts of these strategies on atmospheric greenhouse-gas emissions in different settings at landscape scales
Modelling Framework and the Quantitative Analysis of Distributed Energy Resources in Future Distribution Networks
Retinal Biomarker Discovery for Dementia in an Elderly Diabetic Population
Dementia is a devastating disease, and has severe implications on affected individuals, their family and wider society. A growing body of literature is studying the association of retinal microvasculature measurement with dementia. We present a pilot study testing the strength of groups of conventional (semantic) and texture-based (non-semantic) measurements extracted from retinal fundus camera images to classify patients with and without dementia. We performed a 500-trial bootstrap analysis with regularized logistic regression on a cohort of 1,742 elderly diabetic individuals (median age 72.2). Age was the strongest predictor for this elderly cohort. Semantic retinal measurements featured in up to 81% of the bootstrap trials, with arterial caliber and optic disk size chosen most often, suggesting that they do complement age when selected together in a classifier. Textural features were able to train classifiers that match the performance of age, suggesting they are potentially a rich source of information for dementia outcome classification
TLR7-mediated skin inflammation remotely triggers chemokine expression and leukocyte accumulation in the brain
Background:
The relationship between the brain and the immune system has become increasingly topical as, although it is immune-specialised, the CNS is not free from the influences of the immune system. Recent data indicate that peripheral immune stimulation can significantly affect the CNS. But the mechanisms underpinning this relationship remain unclear. The standard approach to understanding this relationship has relied on systemic immune activation using bacterial components, finding that immune mediators, such as cytokines, can have a significant effect on brain function and behaviour. More rarely have studies used disease models that are representative of human disorders.
Methods:
Here we use a well-characterised animal model of psoriasis-like skin inflammation—imiquimod—to investigate the effects of tissue-specific peripheral inflammation on the brain. We used full genome array, flow cytometry analysis of immune cell infiltration, doublecortin staining for neural precursor cells and a behavioural read-out exploiting natural burrowing behaviour.
Results:
We found that a number of genes are upregulated in the brain following treatment, amongst which is a subset of inflammatory chemokines (CCL3, CCL5, CCL9, CXCL10, CXCL13, CXCL16 and CCR5). Strikingly, this model induced the infiltration of a number of immune cell subsets into the brain parenchyma, including T cells, NK cells and myeloid cells, along with a reduction in neurogenesis and a suppression of burrowing activity.
Conclusions:
These findings demonstrate that cutaneous, peripheral immune stimulation is associated with significant leukocyte infiltration into the brain and suggest that chemokines may be amongst the key mediators driving this response
Protocol for a mixed methods study investigating the impact of investment in housing, regeneration and neighbourhood renewal on the health and wellbeing of residents: the GoWell programme
Background: There is little robust evidence to test the policy assumption that housing-led area regeneration strategies will contribute to health improvement and reduce social inequalities in health. The GoWell Programme has been designed to measure effects on health and wellbeing of multi-faceted regeneration interventions on residents of disadvantaged neighbourhoods in the city of Glasgow, Scotland.
Methods/Design: This mixed methods study focused (initially) on 14 disadvantaged neighbourhoods experiencing regeneration. These were grouped by intervention into 5 categories for comparison. GoWell includes a pre-intervention householder survey (n = 6008) and three follow-up repeat-cross sectional surveys held at two or three year intervals (the main focus of this protocol) conducted alongside a nested longitudinal study of residents from 6 of those areas. Self-reported responses from face-to-face questionnaires are analysed along with various routinely produced ecological data and documentary sources to build a picture of the changes taking place, their cost and impacts on residents and communities. Qualitative methods include interviews and focus groups of residents, housing managers and other stakeholders exploring issues such as the neighbourhood context, potential pathways from regeneration to health, community engagement and empowerment.
Discussion: Urban regeneration programmes are 'natural experiments.' They are complex interventions that may impact upon social determinants of population health and wellbeing. Measuring the effects of such interventions is notoriously challenging. GoWell compares the health and wellbeing effects of different approaches to regeneration, generates theory on pathways from regeneration to health and explores the attitudes and responses of residents and other stakeholders to neighbourhood change
Incentives as connectors : insights into a breastfeeding incentive intervention in a disadvantaged area of North-West England
PMID: 22458841 [PubMed - indexed for MEDLINE] PMCID: PMC3414740 Free PMC ArticlePeer reviewedPublisher PD
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