7,148 research outputs found
Flow Visualisation Studies On Wall Mounted Pitot Type Intake With Splitter Plate
Flow Visualisation Studies Employing Schlieren/Shadowgraph Technique And -Simple Oil Flow Technique Were Carried Out On A Simple Pitot Type Of 1-Btake With Splitter Plate Mounted On Base Plate In The NAL 0 .3m Tunnel . Between The Splitter Plate And The Base Plate, A Heat Exchanger Duct With Wedge Diverters Was Also Simulated . From These Studies, The Effect Of Closure Of The Intake Duct And The Heat Exchanger Duct On The Flow Behaviour Was Qualitatively Determined . It Was Found That Flow Constraint In The Heat Exchanger Duct And Diverter Passages Had Considerable Effect On The Flow Through The Intake
Aging Effects of Caenorhabditis elegans Ryanodine Receptor Variants Corresponding to Human Myopathic Mutations
Delaying the decline in skeletal muscle function will be critical to better maintenance of an active life-style in old age. The skeletal muscle ryanodine receptor, the major intracellular membrane channel through which calcium ions pass to elicit muscle contraction, is central to calcium ion balance, and is hypothesized to be a significant factor for age-related decline in muscle function. The nematode Caenorhabditis elegans is a key model system for the study of human aging and strains with modified C. elegans ryanodine receptors corresponding to human myopathic variants linked with malignant hyperthermia and related conditions were generated. The altered response of these strains to pharmacological agents reflected results of human diagnostic tests for individuals with these pathogenic variants. Involvement of nerve cells in the C. elegans responses may relate to rare medical symptoms concerning the central nervous system that have been associated with ryanodine receptor variants. These single amino acid modifications in C. elegans also conferred a reduction in lifespan and an accelerated decline in muscle integrity with age, supporting the significance of ryanodine receptor function for human aging
Asymptotic behaviour of estimators of the parameters of nearly unstable INAR(1) models
A sequence of first-order integer-valued autoregressive type (INAR(1))
processes is investigated, where the autoregressive type coefficients converge to 1. It
is shown that the limiting distribution of the joint conditional least squares estimators
for this coefficient and for the mean of the innovation is normal. Consequences
for sequences of Galton{Watson branching processes with unobservable immigration,
where the mean of the offspring distribution converges to 1 (which is the
critical value), are discussed
LittleDarwin: a Feature-Rich and Extensible Mutation Testing Framework for Large and Complex Java Systems
Mutation testing is a well-studied method for increasing the quality of a
test suite. We designed LittleDarwin as a mutation testing framework able to
cope with large and complex Java software systems, while still being easily
extensible with new experimental components. LittleDarwin addresses two
existing problems in the domain of mutation testing: having a tool able to work
within an industrial setting, and yet, be open to extension for cutting edge
techniques provided by academia. LittleDarwin already offers higher-order
mutation, null type mutants, mutant sampling, manual mutation, and mutant
subsumption analysis. There is no tool today available with all these features
that is able to work with typical industrial software systems.Comment: Pre-proceedings of the 7th IPM International Conference on
Fundamentals of Software Engineerin
Sex-specific associations of adiposity with cardiometabolic traits in the UK: A multi-life stage cohort study with repeat metabolomics
Background Sex differences in cardiometabolic disease risk are commonly observed across the life course but are poorly understood and may be due to different associations of adiposity with cardiometabolic risk in females and males. We examined whether adiposity is differently associated with cardiometabolic trait levels in females and males at 3 different life stages. Methods and findings Data were from 2 generations (offspring, Generation 1 [G1] born in 1991/1992 and their parents, Generation 0 [G0]) of a United Kingdom population-based birth cohort study, the Avon Longitudinal Study of Parents and Children (ALSPAC). Follow-up continues on the cohort; data up to 25 y after recruitment to the study are included in this analysis. Body mass index (BMI) and total fat mass from dual-energy X-ray absorptiometry (DXA) were measured at mean age 9 y, 15 y, and 18 y in G1. Waist circumference was measured at 9 y and 15 y in G1. Concentrations of 148 cardiometabolic traits quantified using nuclear magnetic resonance spectroscopy were measured at 15 y, 18 y, and 25 y in G1. In G0, all 3 adiposity measures and the same 148 traits were available at 50 y. Using linear regression models, sex-specific associations of adiposity measures at each time point (9 y, 15 y, and 18 y) with cardiometabolic traits 3 to 6 y later were examined in G1. In G0, sex-specific associations of adiposity measures and cardiometabolic traits were examined cross-sectionally at 50 y. A total of 3,081 G1 and 4,887 G0 participants contributed to analyses. BMI was more strongly associated with key atherogenic traits in males compared with females at younger ages (15 y to 25 y), and associations were more similar between the sexes or stronger in females at 50 y, particularly for apolipoprotein B-containing lipoprotein particles and lipid concentrations. For example, a 1 standard deviation (SD) (3.8 kg/m2) higher BMI at 18 y was associated with 0.36 SD (95% confidence interval [CI] = 0.20, 0.52) higher concentrations of extremely large very-low-density lipoprotein (VLDL) particles at 25 y in males compared with 0.15 SD (95% CI = 0.09, 0.21) in females, P value for sex difference = 0.02. By contrast, at 50 y, a 1 SD (4.8 kg/m2) higher BMI was associated with 0.33 SD (95% CI = 0.25, 0.42) and 0.30 SD (95% CI = 0.26, 0.33) higher concentrations of extremely large VLDL particles in males and females, respectively, P value for sex difference = 0.42. Sex-specific associations of DXA-measured fat mass and waist circumference with cardiometabolic traits were similar to findings for BMI and cardiometabolic traits at each age. The main limitation of this work is its observational nature, and replication in independent cohorts using methods that can infer causality is required. Conclusions The results of this study suggest that associations of adiposity with adverse cardiometabolic risk begin earlier in the life course among males compared with females and are stronger until midlife, particularly for key atherogenic lipids. Adolescent and young adult males may therefore be high priority targets for obesity prevention efforts
Brain activity and connectivity during poetry composition: Toward a multidimensional model of the creative process
Creativity, a multifaceted construct, can be studied in various ways, for example, investigating phases of the creative process, quality of the creative product, or the impact of expertise. Previous neuroimaging studies have assessed these individually. Believing that each of these interacting features must be examined simultaneously to develop a comprehensive understanding of creative behavior, we examined poetry composition, assessing process, product, and expertise in a single experiment. Distinct activation patterns were associated with generation and revision, two major phases of the creative process. Medial prefrontal cortex (MPFC) was active during both phases, yet responses in dorsolateral prefrontal and parietal executive systems (DLPFC/IPS) were phase‐dependent, indicating that while motivation remains unchanged, cognitive control is attenuated during generation and re‐engaged during revision. Experts showed significantly stronger deactivation of DLPFC/IPS during generation, suggesting that they may more effectively suspend cognitive control. Importantly however, similar overall patterns were observed in both groups, indicating the same cognitive resources are available to experts and novices alike. Quality of poetry, assessed by an independent panel, was associated with divergent connectivity patterns in experts and novices, centered upon MPFC (for technical facility) and DLPFC/IPS (for innovation), suggesting a mechanism by which experts produce higher quality poetry. Crucially, each of these three key features can be understood in the context of a single neurocognitive model characterized by dynamic interactions between medial prefrontal areas regulating motivation, dorsolateral prefrontal, and parietal areas regulating cognitive control and the association of these regions with language, sensorimotor, limbic, and subcortical areas distributed throughout the brain. Hum Brain Mapp 36:3351–3372, 2015. © 2015 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113109/1/hbm22849.pd
Unrelated Helpers in a Primitively Eusocial Wasp: Is Helping Tailored Towards Direct Fitness?
The paper wasp Polistes dominulus is unique among the social insects in that nearly one-third of co-foundresses are completely unrelated to the dominant individual whose offspring they help to rear and yet reproductive skew is high. These unrelated subordinates stand to gain direct fitness through nest inheritance, raising the question of whether their behaviour is adaptively tailored towards maximizing inheritance prospects. Unusually, in this species, a wealth of theory and empirical data allows us to predict how unrelated subordinates should behave. Based on these predictions, here we compare helping in subordinates that are unrelated or related to the dominant wasp across an extensive range of field-based behavioural contexts. We find no differences in foraging effort, defense behaviour, aggression or inheritance rank between unrelated helpers and their related counterparts. Our study provides no evidence, across a number of behavioural scenarios, that the behaviour of unrelated subordinates is adaptively modified to promote direct fitness interests
Gravitational redshift of galaxies in clusters as predicted by general relativity
The theoretical framework of cosmology is mainly defined by gravity, of which
general relativity is the current model. Recent tests of general relativity
within the \Lambda Cold Dark Matter (CDM) model have found a concordance
between predictions and the observations of the growth rate and clustering of
the cosmic web. General relativity has not hitherto been tested on cosmological
scales independent of the assumptions of the \Lambda CDM model. Here we report
observation of the gravitational redshift of light coming from galaxies in
clusters at the 99 per cent confidence level, based upon archival data. The
measurement agrees with the predictions of general relativity and its
modification created to explain cosmic acceleration without the need for dark
energy (f(R) theory), but is inconsistent with alternative models designed to
avoid the presence of dark matter.Comment: Published in Nature issued on 29 September 2011. This version
includes the Letter published there as well as the Supplementary Information.
23 pages, 7 figure
Management of the mass casualty from the 2001 Jos crisis
Background: We report our experience in the hospital management of mass casualty following the Jos civil crisis of 2001.Materials and Methods: Aretrospective analysis of the records of patients managed in the Jos civil crisis of September 2001, in Plateau State, Nigeria. Information extracted included demographic data of patients, mechanisms of injury, nature and site of injury, treatment modalities and outcome of care.Results: A total of 463 crisis victims presented over a 5 day period. Out of these, the records of 389 (84.0%) were available and analyzed. There were 348 (89.5%) males and 41 females (10.5%) aged between 3 weeks and 70 years, with a median age of 26 years. Most common mechanisms of injury were gunshot in 176 patients (45.2%) and blunt injuries from clubs and sticks in 140 patients (36.0%). Debridement with or without suturing was the most common surgical procedure, performed in 128 patients (33%) followed by exploratory laparotomy in 27 (6.9%) patients. Complications were documented in 55 patients (14.1%) and there were 16 hospital deaths (4.1% mortality). Challenges included exhaustion of supplies, poor communication and security threats both within the hospital and outside.Conclusion: Most patients reaching the hospital alive had injuries that did not require lifesaving interventions. Institutional preparedness plan would enable the hospital to have an organized approach to care, with better chances of success. More effective means of containing crises should be employed to reduce the attendant casualty rate.Key words: Challenges, civilian conflicts, crisis, disaster, mass casualty, trauma, violenc
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