2,591 research outputs found
First Observational Tests of Eternal Inflation: Analysis Methods and WMAP 7-Year Results
In the picture of eternal inflation, our observable universe resides inside a
single bubble nucleated from an inflating false vacuum. Many of the theories
giving rise to eternal inflation predict that we have causal access to
collisions with other bubble universes, providing an opportunity to confront
these theories with observation. We present the results from the first
observational search for the effects of bubble collisions, using cosmic
microwave background data from the WMAP satellite. Our search targets a generic
set of properties associated with a bubble collision spacetime, which we
describe in detail. We use a modular algorithm that is designed to avoid a
posteriori selection effects, automatically picking out the most promising
signals, performing a search for causal boundaries, and conducting a full
Bayesian parameter estimation and model selection analysis. We outline each
component of this algorithm, describing its response to simulated CMB skies
with and without bubble collisions. Comparing the results for simulated bubble
collisions to the results from an analysis of the WMAP 7-year data, we rule out
bubble collisions over a range of parameter space. Our model selection results
based on WMAP 7-year data do not warrant augmenting LCDM with bubble
collisions. Data from the Planck satellite can be used to more definitively
test the bubble collision hypothesis.Comment: Companion to arXiv:1012.1995. 41 pages, 23 figures. v2: replaced with
version accepted by PRD. Significant extensions to the Bayesian pipeline to
do the full-sky non-Gaussian source detection problem (previously restricted
to patches). Note that this has changed the normalization of evidence values
reported previously, as full-sky priors are now employed, but the conclusions
remain unchange
Alleviation of Brain Injury-Induced Cerebral Metabolic Depression by Amphetamine: A Cytochrome Oxidase Histochemistry Study
Measurements of oxidative metabolic
capacity following the ablation of rat sensorimotor
cortex and ,he administration of amphetamine
were examined to determine their
effects on the metabolic dysfunction that
follows brain injury. Twenty-four hours after
surgery, rats sustaining either sham operations
or unilateral cortical ablation were administered
a single injection of D-amphetamine (2 mg/kg;
i.p.) or saline and then sacrificed 24 h later.
Brain tissue was processed for cytochrome
oxidase histochemistry, and 12 bilateral cerebral
areas were measured, using optical density as
an index of the relative amounts of the
enzyme. Compared with that of the control
groups, cytochrome oxidase in the injured
animals was significantly reduced throughout
the cerebral cortex and in 5 of II subcortical
structures. This injury-induced depression of
oxidative capacity was most pronounced in
regions of the hemisphere ipsilateral to the
ablation. Animals given D-amphetamine had less depression of oxidative capacity, which
was most pronounced bilaterally in the cerebral
cortex, red nucleus, and superior colliculus;
and in the nucleus accumbens, caudateputamen,
and globus pallidus ipsilaterai to the
ablation. The ability of D-amphetamine to
alleviate depressed cerebral oxidative metabolism
following cortical injury may be one mechanism
by which drugs increasing noradrenaline
release accelerate functional recovery in both
animals and humans
Patterns of dairy food intake, body composition and markers of metabolic health in Ireland:results from the National Adult Nutrition Survey
Background: Studies examining the association between dairy consumption and metabolic health have shown mixed results. This may be due, in part, to the use of different definitions of dairy, and to single types of dairy foods examined in isolation. Objective: The objective of the study was to examine associations between dairy food intake and metabolic health, identify patterns of dairy food consumption and determine whether dairy dietary patterns are associated with outcomes of metabolic health, in a cross-sectional survey. Design: A 4-day food diary was used to assess food and beverage consumption, including dairy (defined as milk, cheese, yogurt, cream and butter) in free-living, healthy Irish adults aged 18–90 years (n=1500). Fasting blood samples (n=897) were collected, and anthropometric measurements taken. Differences in metabolic health markers across patterns and tertiles of dairy consumption were tested via analysis of covariance. Patterns of dairy food consumption, of different fat contents, were identified using cluster analysis. Results: Higher (total) dairy was associated with lower body mass index, %body fat, waist circumference and waist-to-hip ratio (P<0.001), and lower systolic (P=0.02) and diastolic (P<0.001) blood pressure. Similar trends were observed when milk and yogurt intakes were considered separately. Higher cheese consumption was associated with higher C-peptide (P<0.001). Dietary pattern analysis identified three patterns (clusters) of dairy consumption; 'Whole milk', 'Reduced fat milks and yogurt' and 'Butter and cream'. The 'Reduced fat milks and yogurt' cluster had the highest scores on a Healthy Eating Index, and lower-fat and saturated fat intakes, but greater triglyceride levels (P=0.028) and total cholesterol (P=0.015). conclusion: Overall, these results suggest that while milk and yogurt consumption is associated with a favourable body phenotype, the blood lipid profiles are less favourable when eaten as part of a low-fat high-carbohydrate dietary pattern. More research is needed to better understand this association. Conclusion: Overall, these results suggest that although milk and yogurt consumption is associated with a favourable body phenotype, the blood lipid profiles are less favourable when eaten as part of a low-fat high-carbohydrate dietary pattern. More research is needed to better understand this association
Evidence of a relationship between adult attachment variables and appraisals of chronic pain
Objective: Although threat and challenge appraisals of pain have been linked to both the acute and laboratory-induced pain experience, these appraisals have not yet been explored in relation to chronic pain. In addition, although attachment theory has been separately linked to the chronic pain experience and to responses to perceived threat, it has not been explored in the context of threat and challenge appraisals of chronic pain. The present paper addresses these two main goals. Methods: A sample of 141 participants reporting noncancer pain longer than two months in duration completed a battery of assessments before commencing treatment in one of two multidisciplinary rehabilitation programs. Results: Analysis of the pain appraisal inventory produced two factors (threat and challenge), replicating earlier findings. Reliability coefficients for the two extracted scales were 0.87 and 0.86, respectively. Links between the two pain appraisal scales and adult attachment variables proved to be significant. In particular, comfort with closeness was strongly related to challenge appraisal, while anxiety over relationships was strongly associated with threat appraisal. As expected, both appraisals and attachment variables were also related to catastrophizing and emotional distress. Conclusions: Results support use of the pain appraisal inventory as an evaluation tool for those with chronic pain. Findings further suggest a substantial association between adult attachment and pain appraisal, supporting the need for more in-depth analysis and consideration of implications for treatment
The effects of altered distances between obstacles on the jump kinematics and apparent joint angulations of large agility dogs
Canine agility is a rapidly growing sport in the UK. However, there is a paucity of scientific research examining jump kinematics and associated health and welfare implications of the discipline. The aim of this research was to examine differences in jump kinematics and apparent joint angulation of large (> 431 mm at the withers) agility dogs (n = 54), when the distance between hurdles was altered (3.6 m, 4 m and 5 m apart) and to determine how level of skill impacted upon jump kinematics. Significant differences were observed for both the take-off (P < 0.001) and landing distances (P < 0.001) between the 3.6 m, 4 m and 5 m distances. Further differences were observed when level of skill was controlled for; take-off (F[3,55] = 5.686, P = 0.002) and landing (F[3,55] = 7.552, P < 0.001) distances differed at the 3.6 m distance, as did the take-off distance at the 4 m hurdle distance (F[3,50] = 6.168, P = 0.001). Take-off and landing speeds differed for hurdle distances (P < 0.001) and level of skill (P < 0.001). There were significant differences in apparent neck angle during take-off and landing (P < 0.001), lumbar spine angles during take-off, bascule and landing (P < 0.01), and in shoulder angles during the bascule phase (P < 0.05). The results indicate that agility dogs alter their jumping patterns to accommodate the spacing between hurdles, which ultimately may impact long term health and welfare due to altered kinematics
Raising argument strength using negative evidence: A constraint on models of induction
Both intuitively, and according to similarity-based theories of induction, relevant evidence raises argument strength when it is positive and lowers it when it is negative. In three experiments, we tested the hypothesis that argument strength can actually increase when negative evidence is introduced. Two kinds of argument were compared through forced choice or sequential evaluation: single positive arguments (e.g., “Shostakovich’s music causes alpha waves in the brain; therefore, Bach’s music causes alpha waves in the brain”) and double mixed arguments (e.g., “Shostakovich’s music causes alpha waves in the brain, X’s music DOES NOT; therefore, Bach’s music causes alpha waves in the brain”). Negative evidence in the second premise lowered credence when it applied to an item X from the same subcategory (e.g., Haydn) and raised it when it applied to a different subcategory (e.g., AC/DC). The results constitute a new constraint on models of induction
Romantic jealousy and relationship satisfaction: the costs of rumination
The experience of romantic jealousy and its influence on relationship outcomes is unclear. Romantic jealousy is often associated with damaging effects; on the other hand, jealousy is linked to positive relationship outcomes such as increased commitment. In this study, we aimed to address inconsistencies in previous research by proposing rumination as a mediator between romantic jealousy (cognitive jealousy and surveillance behaviors) and relationship dissatisfaction. We also aimed to extend our understanding of behavioral responses to jealousy, and in particular, partner surveillance and its link to relational dissatisfaction by proposing a research question. Overall, there were two paths to relationship dissatisfaction: Cognitive jealousy and surveillance behaviors were associated with relationship dissatisfaction via rumination, and cognitive jealousy was also directly associated with relationship dissatisfaction. Interestingly, surveillance behaviors were directly associated with relationship satisfaction. From these results, rumination is highlighted as a factor in explaining the link between romantic jealousy and relationship dissatisfaction. Clinical implications are discussed
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