83 research outputs found
The GALEX UV emission in shell galaxies: tracing galaxy "rejuvenation" episodes
We present the GALEX far FUV and near NUV ultraviolet imaging of three nearby
shell galaxies, namely NGC 2865, NGC 5018 and NGC 7135. The system of shells
and fine structures visible in the optical is detected in the NUV image of NGC
2865 and in both NUV and FUV images of NGC 7135. The NUV image of NGC 5018 does
not present shell structures. We detect absorption features in the nuclear
region of all three galaxies. NGC 2865 has a nearly flat colour profile with
(FUV-NUV)~2 throughout the whole galaxy. NGC 7135 is blue in the center
(FUV-NUV)~0 and as red as (FUV-NUV)~1.5 in the outskirts, including the faint
shell-like feature. We investigate the ability of the nuclear GALEX (FUV-NUV)
colour to provide information about rejuvenation phenomena in the stellar
populations of the shell galaxies. To this aim, we derive from theory the
relationship between the Mg2, Hbeta, HgammaA, HdeltaA Lick line-strength
indices and the (FUV-NUV) colour. We extend the study to a sample of early-type
galaxies with emission lines in their optical spectra (Annibali et al. 2007).
In the index vs.(FUV-NUV) colour diagrams, most of the galaxies are well
explained by passively evolving SSPs. On the average, ages and metallicities of
the galaxies in our sample estimated from optical line-strength indices are
consistent with those inferred from the (FUV-NUV) colour. In general, all the
colours but for (FUV-NUV) and (FUV-V), become nearly age insensitive when 1-2
Gyr have elapsed from the last star forming event. Considering composite
stellar population models with a recent burst of star formation, we suggest
that the position of the NGC 7135 and NGC 2865 nuclei in the (FUV-NUV)-Hbeta
plane could be explained in term of a recent rejuvenation episode. (Abridged)Comment: Accepted for publication in MNRAS Main Journal, 21 pages, 15 figure
Walk well:a randomised controlled trial of a walking intervention for adults with intellectual disabilities: study protocol
Background - Walking interventions have been shown to have a positive impact on physical activity (PA) levels, health and wellbeing for adult and older adult populations. There has been very little work carried out to explore the effectiveness of walking interventions for adults with intellectual disabilities. This paper will provide details of the Walk Well intervention, designed for adults with intellectual disabilities, and a randomised controlled trial (RCT) to test its effectiveness. Methods/design - This study will adopt a RCT design, with participants allocated to the walking intervention group or a waiting list control group. The intervention consists of three PA consultations (baseline, six weeks and 12 weeks) and an individualised 12 week walking programme. A range of measures will be completed by participants at baseline, post intervention (three months from baseline) and at follow up (three months post intervention and six months from baseline). All outcome measures will be collected by a researcher who will be blinded to the study groups. The primary outcome will be steps walked per day, measured using accelerometers. Secondary outcome measures will include time spent in PA per day (across various intensity levels), time spent in sedentary behaviour per day, quality of life, self-efficacy and anthropometric measures to monitor weight change. Discussion - Since there are currently no published RCTs of walking interventions for adults with intellectual disabilities, this RCT will examine if a walking intervention can successfully increase PA, health and wellbeing of adults with intellectual disabilities
Space charge saturated sheath regime and electron temperature saturation in Hall thrusters
Secondary electron emission in Hall thrusters is predicted to lead to space charge saturated wall sheaths resulting in enhanced power losses in the thruster channel. Analysis of experimentally obtained electron-wall collision frequency suggests that the electron temperature saturation, which occurs at high discharge voltages, appears to be caused by a decrease of the Joule heating rather than by the enhancement of the electron energy loss at the walls due to a strong secondary electron emission
Effect of Carnitine and herbal mixture extract on obesity induced by high fat diet in rats
<p>Abstract</p> <p>Background</p> <p>Obesity-associated type 2 diabetes is rapidly increasing throughout the world. It is generally recognized that natural products with a long history of safety can modulate obesity.</p> <p>Aim</p> <p>To investigate the development of obesity in response to a high fat diet (HFD) and to estimate the effect of L-carnitine and an Egyptian Herbal mixture formulation (HMF) (consisting of T. chebula, Senae, rhubarb, black cumin, aniseed, fennel and licorice) on bodyweight, food intake, lipid profiles, renal, hepatic, cardiac function markers, lipid Peroxidation, and the glucose and insulin levels in blood and liver tissue in rats.</p> <p>Method</p> <p>White male albino rats weighing 80-90 gm, 60 days old. 10 rats were fed a normal basal diet (Cr), 30 rats fed a high-fat diet (HFD) for 14 weeks during the entire study. Rats of the HFD group were equally divided into 3 subgroups each one include 10 rats. The first group received HFD with no supplement (HFD), the 2<sup>nd </sup>group HFD+L-carnitine and the third group received HFD+HMF. Carnitine and HMF were administered at 10<sup>th </sup>week (start time for treatments) for 4 weeks.</p> <p>Body weight, lipid profile & renal function (urea, uric acid creatinine) ALT & AST activities, cardiac markers, (LDH, C.K-NAC and MB) the oxidative stress marker reduced glutathione (GSH), and Malondialdehyde (MDA) catalase activity, in addition to glucose, insulin, and insulin resistance in serum & tissues were analyzed.</p> <p>Results</p> <p>Data showed that feeding HFD diet significantly increased final body weight, triglycerides (TG), total cholesterol, & LDL concentration compared with controls, while significantly decreasing HDL; meanwhile treatment with L-carnitine, or HMF significantly normalized the lipid profile.</p> <p>Serum ALT, urea, uric acid, creatinine, LDH, CK-NAC, CK-MB were significantly higher in the high fat group compared with normal controls; and administration of L-carnitine or herbal extract significantly lessened the effect of the HFD. Hyperglycemia, hyperinsulinemia, and high insulin resistance (IR) significantly increased in HFD in comparison with the control group. The treatment with L-carnitine or HMF improved the condition. HFD elevated hepatic MDA and lipid peroxidation associated with reduction in hepatic GSH and catalase activity; whereas administration of L-carnitine or herbal extract significantly ameliorated these hepatic alterations.</p> <p>Conclusion</p> <p>HFD induced obesity associated with a disturbed lipid profile, defective antioxidant stability, and high values of IR parameters; this may have implications for the progress of obesity related problems. Treatment with L-carnitine, or HMF extract improved obesity and its associated metabolic problems in different degrees. Also HMF has antioxidant, hypolipidaemic insulin sensitizing effects. Moreover HMF might be a safe combination on the organs whose functions were examined, as a way to surmount the obesity state; and it has a distinct anti-obesity effect.</p
Estudios físicos de las estrellas pulsantes Delta Cephei y su uso para la determinación de las distancias de sistemas extragalácticos. IV etapa.
IP 1101-05-153-89ARTICULO(S)EN REVISTA: The short period cepheid E.U tau. II physical properties oh the star / Wolfgang P.;Gieren - En: The astronomical journal vol. 99 No 4 (abril: 1990); p. 1196-1206
Overview of tracer techniques in studies of material erosion, re-deposition and fuel inventory in Tokamaks
C-13 labeled methane and rhenium-boron coated plates were used at the JET tokamak as tracers for studies of the material transport, its erosion and re-deposition. Experimental procedures are described. The results are discussed in terms of processes underlying the material transport and the change of morphology of targets exposed to the plasma: physical sputtering, chemical erosion, prompt re-deposition. The influence of wall materials on fuel inventory is also addressed. C-14 measurements in the TEXTOR tokamak are presented and possibilities of using C-14 in carbon migration studies are considered. (C) 2004 Elsevier B.V. All rights reserved
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