1,342 research outputs found
L-Arginine promotes gut hormone release and reduces food intake in rodents
Aims: To investigate the anorectic effect of Lâarginine (LâArg) in rodents.
Methods: We investigated the effects of LâArg on food intake, and the role of the anorectic gut hormones glucagonâlike peptideâ1 (GLPâ1) and peptide YY (PYY), the Gâproteinâcoupled receptor family C group 6 member A (GPRC6A) and the vagus nerve in mediating these effects in rodents.
Results: Oral gavage of LâArg reduced food intake in rodents, and chronically reduced cumulative food intake in dietâinduced obese mice. Lack of the GPRC6A in mice and subdiaphragmatic vagal deafferentation in rats did not influence these anorectic effects. LâArg stimulated GLPâ1 and PYY release in vitro and in vivo. Pharmacological blockade of GLPâ1 and PYY receptors did not influence the anorectic effect of LâArg. LâArgâmediated PYY release modulated net ion transport across the gut mucosa. Intracerebroventricular (i.c.v.) and intraperitoneal (i.p.) administration of LâArg suppressed food intake in rats.
Conclusions: LâArg reduced food intake and stimulated gut hormone release in rodents. The anorectic effect of LâArg is unlikely to be mediated by GLPâ1 and PYY, does not require GPRC6A signalling and is not mediated via the vagus. I.c.v. and i.p. administration of LâArg suppressed food intake in rats, suggesting that LâArg may act on the brain to influence food intake. Further work is required to determine the mechanisms by which LâArg suppresses food intake and its utility in the treatment of obesity
Surprising dissimilarities in a newly formed pair of 'identical twin' stars
The mass and chemical composition of a star are the primary determinants of
its basic physical properties--radius, temperature, luminosity--and how those
properties evolve with time. Thus, two stars born at the same time, from the
same natal material, and with the same mass are 'identical twins,' and as such
might be expected to possess identical physical attributes. We have discovered
in the Orion Nebula a pair of stellar twins in a newborn binary star system.
Each star in the binary has a mass of 0.41 +/- 0.01 solar masses, identical to
within 2 percent. Here we report that these twin stars have surface
temperatures that differ by ~300K (~10%), and luminosities that differ by ~50%,
both at high confidence level. Preliminary results indicate that the stars'
radii also differ, by 5-10%. These surprising dissimilarities suggest that one
of the twins may have been delayed by several hundred thousand years in its
formation relative to its sibling. Such a delay could only have been detected
in a very young, definitively equal-mass binary system3 such as that reported
here. Our findings reveal cosmic limits on the age synchronisation of young
binary stars, often used as tests for the age calibrations of star-formation
models.Comment: Published in Nature, 19 June 200
Emplacement of inflated PÄhoehoe flows in the Naudeâs Nek Pass, Lesotho remnant, Karoo continental flood basalt province: use of flow-lobe tumuli in understanding flood basalt emplacement
Physical volcanological features are presented for a 710-m-thick section, of the Naudeâs Nek Pass, within the lower part of the Lesotho remnant of the Karoo Large Igneous Province. The section consists of inflated pÄhoehoe lava with thin, impersistent sedimentary interbeds towards the base. There are seven discreet packages of compound and hummocky pÄhoehoe lobes containing flow-lobe tumuli, making up approximately 50% of the section. Approximately 45% of the sequence consists of 14 sheet lobes, between 10 and 52-m-thick. The majority of the sheet lobes are in two packages indicating prolonged periods of lava supply capable of producing thick sheet lobes. The other sheet lobes are as individual lobes or pairs, within compound flows, suggesting brief increases in lava supply rate. We suggest, contrary to current belief, that there is no evidence that compound flows are proximal to source and sheet lobes (simple flows) are distal to source and we propose that the presence of flow-lobe tumuli in compound flows could be an indicator that a flow is distal to source. We use detailed, previously published, studies of the Thakurvadi Formation (Deccan Traps) as an example. We show that the length of a lobe and therefore the sections that are âmedial or distal to sourceâ are specific to each individual lobe and are dependent on the lava supply of each eruptive event, and as such flow lobe tumuli can be used as an indicator of relative distance from source
Root aphid (Aploneura lentisci) population size on perennial ryegrass is determined by drought and endophyte strain
Climate change is anticipated to lead to an increase in the occurrence and intensity of drought and fluctuations in insect cycles that will challenge modern pasture systems. Feeding by root aphids such as Aploneura lentisci Pass. can be a significant challenge to pastures. These below-ground living aphids are commonly found in New Zealand and Australia, feeding year-round on the roots of graminaceous plants such as perennial ryegrass (Lolium perenne L.). Some strains of the fungal endophyte Epichloë festucae var. lolii in perennial ryegrass can provide protection against root aphids and greater resilience under drought, contributing to higher persistency and growth than endophyte-free plants. However, the interaction between insect pressure and drought is not understood. This study examined the effect of drought on root aphid populations and plant performance in perennial ryegrass plants relative to endophyte status (±) and endophyte strain (AR37, NZCT) in a glasshouse experiment. Plants were cloned across the drought and well-watered treatments, and half of the plants were inoculated with root aphids, whilst half of the plants were treated with insecticide. Endophyte infection with strain NZCT and AR37 reduced root aphid numbers. Aphid populations were significantly higher in drought-stressed than in well-watered plants in both endophyte-infected and endophyte-free treatments. Under drought conditions, root aphid populations were increased 4-fold in NZCT and 8-fold in AR37 and endophyte-free plants in comparison with their well-watered counterparts. Root aphids reduced shoot dry weight by 16% in drought-exposed and 26% in well-watered plants in comparison with their insecticide-treated counterparts whilst reducing root biomass by 49%. Our results suggest that root aphids are likely able to exploit the higher availability of amino acids in the plant sap of drought-exposed plants. This study provides evidence that climate change-mediated impacts of root aphids could reduce production in perennial ryegrass-dominant pastures. However, field trials would be necessary to determine whether this effect is seen in situ, where numerous additional factors will be operating at the same time
An Autopsy Study Describing Causes of Death and Comparing Clinico-Pathological Findings among Hospitalized Patients in Kampala, Uganda
Background: Information on causes of death in HIV-infected patients in Sub-Saharan Africa is mainly derived from observational cohort and verbal autopsy studies. Autopsy is the gold standard to ascertain cause of death. We conducted an autopsy study to describe and compare the clinical and autopsy causes of death and contributory findings in hospitalized HIV-infected and HIV-uninfected patients in Uganda. Methods: Between May and September 2009 a complete autopsy was performed on patients that died on a combined infectious diseases gastroenterology ward in Mulago Hospital in Kampala, Uganda. Autopsy cause of death and contributing findings were based on the macro- and microscopic post-mortem findings combined with clinical information. Clinical diagnoses were reported by the ward doctor and classified as confirmed, highly suspected, considered or not considered, based on information derived from the medical chart. Results are reported according to HIV serostatus. Results: Fifty-three complete autopsies were performed in 66 % HIV-positive, 21 % HIV-negative and 13 % patients with an unknown HIV serological status. Infectious diseases caused death in 83 % of HIV-positive patients, with disseminated TB as the main diagnosis causing 37 % of deaths. The spectrum of illness and causes of death were substantially different betwee
Synergism of verbal autopsy and diagnostic pathology autopsy for improved accuracy of mortality data
Holographic Kondo Model in Various Dimensions
We study the addition of localised impurities to U(N) Supersymmetric
Yang-Mills theories in (p+1)-dimensions by using the gauge/gravity
correspondence. From the gravity side, the impurities are introduced by
considering probe D(8-p)-branes extendingalong the time and radial directions
and wrapping an (7-p)-dimensional submanifold of the internal (8-p)-sphere, so
that the degrees of freedom are point-like from the gauge theory perspective.
We analyse both the configuration in which the branes generate straight flux
tubes -corresponding to actual single impurities - and the one in which
connected flux tubes are created- corresponding to dimers. We discuss the
thermodynamics of both the configurations and the related phase transition. In
particular, the specific heat of the straight flux-tube configuration is
negative for p<3, while it is never the case for the connected one. We study
the stability of the system by looking at the impurity fluctuations. Finally,
we characterise the theory by computing one- and two-point correlators of the
gauge theory operators dual to the impurity fluctuations. Because of the
underlying generalised conformal structure, such correlators can be expressed
in terms of an effective coupling constant (which runs because of its
dimensionality) and a generalised conformal dimension.Comment: 56 pages, 3 figures; v2: typos correcte
Protocol for the 'e-Nudge trial' : a randomised controlled trial of electronic feedback to reduce the cardiovascular risk of individuals in general practice [ISRCTN64828380]
Background: Cardiovascular disease (including coronary heart disease and stroke) is a major
cause of death and disability in the United Kingdom, and is to a large extent preventable, by lifestyle
modification and drug therapy. The recent standardisation of electronic codes for cardiovascular
risk variables through the United Kingdom's new General Practice contract provides an
opportunity for the application of risk algorithms to identify high risk individuals. This randomised
controlled trial will test the benefits of an automated system of alert messages and practice
searches to identify those at highest risk of cardiovascular disease in primary care databases.
Design: Patients over 50 years old in practice databases will be randomised to the intervention
group that will receive the alert messages and searches, and a control group who will continue to
receive usual care. In addition to those at high estimated risk, potentially high risk patients will be
identified who have insufficient data to allow a risk estimate to be made. Further groups identified
will be those with possible undiagnosed diabetes, based either on elevated past recorded blood
glucose measurements, or an absence of recent blood glucose measurement in those with
established cardiovascular disease.
Outcome measures: The intervention will be applied for two years, and outcome data will be
collected for a further year. The primary outcome measure will be the annual rate of cardiovascular
events in the intervention and control arms of the study. Secondary measures include the
proportion of patients at high estimated cardiovascular risk, the proportion of patients with missing
data for a risk estimate, and the proportion with undefined diabetes status at the end of the trial
Magnetic loop antenna with electronic tuning for frequencies below 30MHz
Tento projekt se zabĂœvĂĄ nĂĄvrhem elektronickĂ©ho ladÄnĂ a automatizovanĂ©ho pĆizpĆŻsobenĂ magnetickĂœch, smyÄkovĂœch antĂ©n, pracujĂcĂch v oblasti krĂĄtkĂœch vln. CelĂĄ prĂĄce je rozdÄlena do tĆĂ ÄĂĄstĂ (ladĂcĂ, pĆizpĆŻsobovacĂ a ĆĂdĂcĂ). LadĂcĂ ÄĂĄst je realizovanĂĄ zmÄnou kapacity pomocĂ kaskĂĄdy kondenzĂĄtorĆŻ a pĆizpĆŻsobovĂĄnĂ je provedeno rĆŻznĂœmi zmÄnami bodĆŻ napĂĄjenĂ. CelĂœ systĂ©m je ĆĂzen mikroprocesorem ATmega16. Dle poĆŸadavkĆŻ obsluĆŸnĂ©ho programu, spĂnĂĄ mikroprocesor pĆĂsluĆĄnĂ© kapacity, ÄĂmĆŸ ladĂ antĂ©nu na potĆebnĂœ kmitoÄet, pracovĂĄvĂĄ informace o vĂœkonovĂ©m pĆizpĆŻsobenĂ a automaticky dolaÄuje antĂ©nu zmÄnou polohy napĂĄjenĂ.This project deals with electronic tuning and automated adjustment of magnetic loop antennas, working in the High Frequencys. The whole work is divided into three parts tuning, adjustment and control). The tuning part is realized by changing the capacity of the array capacitors and adjustment is done by different changes of power points. The whole system is controlled by a microprocessor ATmega16. According to utility switches the microprocessor capacity, which tunes the antenna to the required frequency, processes information about power adjustment and autimatically fine-tuning the antenna by changing the position of charging.
Altered splicing of the BIN1 muscle-specific exon in humans and dogs with highly progressive centronuclear myopathy
Amphiphysin 2, encoded by BIN1, is a key factor for membrane sensing and remodelling in different cell types. Homozygous BIN1 mutations in ubiquitously expressed exons are associated with autosomal recessive centronuclear myopathy (CNM), a mildly progressive muscle disorder typically showing abnormal nuclear centralization on biopsies. In addition, misregulation of BIN1 splicing partially accounts for the muscle defects in myotonic dystrophy (DM). However, the muscle-specific function of amphiphysin 2 and its pathogenicity in both muscle disorders are not well understood. In this study we identified and characterized the first mutation affecting the splicing of the muscle-specific BIN1 exon 11 in a consanguineous family with rapidly progressive and ultimately fatal centronuclear myopathy. In parallel, we discovered a mutation in the same BIN1 exon 11 acceptor splice site as the genetic cause of the canine Inherited Myopathy of Great Danes (IMGD). Analysis of RNA from patient muscle demonstrated complete skipping of exon 11 and BIN1 constructs without exon 11 were unable to promote membrane tubulation in differentiated myotubes. Comparative immunofluorescence and ultrastructural analyses of patient and canine biopsies revealed common structural defects, emphasizing the importance of amphiphysin 2 in membrane remodelling and maintenance of the skeletal muscle triad. Our data demonstrate that the alteration of the muscle-specific function of amphiphysin 2 is a common pathomechanism for centronuclear myopathy, myotonic dystrophy, and IMGD. The IMGD dog is the first faithful model for human BIN1-related CNM and represents a mammalian model available for preclinical trials of potential therapies
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