92 research outputs found

    LIPID PEROXIDATION AND ANTIOXIDANT STATUS: A COMPARISON BETWEEN MIDDLE AGED AND ELDERLY POPULATION

    Get PDF
    Objective : In recent years a large body of experimental research indicates that oxidative stress and antioxidant defenses are related to processes  such as aging and several diseases.Vitamins and antioxidant enzymes have a fundamental role in defending organisms from oxidative stress.The objective of present study was to compare age related oxidative stress in middle aged and older subjects. Design: The present hospital based nonintervention cross sectional study was designed to evaluate age related oxidative stress and its impact in 40 middle aged (35-55y) and 40 older subjects (60y)  by measuring Thiobarbituric Acid Reactive substances (TBARs) for lipid  peroxidation vis-à-vis antioxidant defense with estimatimation of plasma superoxide dismutase (SOD) and serum alpha-tocopherol concentration . Intervention: none Results: On the basis of the data obtained from our study it was evident that concentration of Thiobarbituric Acid reactive substances were significantly higher in older subjects, whereas enzymatic antioxidant serum superoxide dismutase and free radical scavenging alpha-tocopherol (vitamin E) were significantly lower in elderly age group than middle aged subjects. Conclusion :The present study provides some important information regarding age related oxidative stress in elderly population compared to middle aged subjects. Lipid peroxidation which refers to oxidative degradation of lipids and acts as an oxidative  stressor in the organism is significantly higher in elderly subjects but in so far as antioxidants are concerned we observe that they are significantly lower in elderly than middle aged subjects. Keywords: aging, antioxidant ,lipid peroxidation, oxidative stres

    EFFECT OF SUB MAXIMAL EXERCISE ON ENDOTHELIUM-DERIVED NITRIC OXIDE CONCENTRATIONS IN HEALTHY YOUNG SUBJECTS.

    Get PDF
    Objective: To determine any possible contribution of 10 minutes single session sub maximal exercise on Nitric oxide level in healthy young population.Design: A descriptive observational study on forty healthy volunteers (20 male & 20 female) of 20-30 years designed to evaluate the level of nitric oxide after 10 minutes cycling.Intervention:  Young populations are allowed to exercise in a bicycle ergo meter for 10 minutes regular exercise under protocol YMCA Sub maximal Cycle Ergo meter Testing against a constant workload.  Main outcome measures: Serum Creatine Phosphokinase  and  Nitrate-Nitrite ratio (Surrogate marker of nitric oxide)  measured. Continuous heart rate monitoring is done from ECG system. Vo2 max calculated and energy expenditure for physical activity obtained from prediction equation after adjusting age, gender & body mass.Results: Comparison of Activity Energy Expenditure (AEE) before and after exercise done, (p value<0.0001)(n = 40).  Significant amount of  work done in this exercise. Increase in the serum creatine phosphokinase level (p value<0.0001). Serum Nitrate-Nitrite ratio (nitric oxide level) showed increase (p value 0.1113) in post exercise level.Conclusion: As far as energy expenditure concerned, significant muscular activity in both male & female showed insignificant endothelium derived Nitric oxide production. On the basis of the data obtained it is evident that in a single session sub maximal exercise beneficial effect of vasodilator Nitric oxide was not observed in studied  young population.Keywords: sub maximal exercise, activity energy expenditure, nitrate-nitrite ratio

    日本イエズス会版『サルヴァトル・ムンヂ』ポルトガル語全訳注 : 第一誡「御一体のデウスを敬ひ,貴み奉るべし」に関わる10の尋問

    Get PDF
    A new method for the preparation of the synthon (±)-2,6,7,7a-tetrahydro-1β-hydroxy-4-formyl-7aβ-methylindene (1,a) for the total synthesis of steroids in both (±) and (+) forms, starting from the known β-ketoester, (±)-methyl 1β-t-butoxy-5,6,7,7a-tetrahydro-7aβ-methyl-5-keto-4-indancarboxylate (2,a) has been described. An alternative route to (1,a) has been investigated. Although the compound, (±)-1β-hydroxy-5,6,7,7a-tetrahydro-7aβ-methyl-5-keto-4-methoxymethylindan (2,b) could not be prepared, interesting pathways leading to two unexpected products, (±)-5,6,7,7a-tetrahydro-4,7a-dimethyl-5H-indene-1,5-dione and (±)-2,6-diketo-3-methyltricyclo-(5,2,1,0)decan-8-ol (3 and 4), were encountered during an attempted annelation reaction of the ketone, N-diethylamino-5-methoxypentan-3-one (6), with 2-methylcyclopentan-1,3-dione (5). Trapping of the intermediate, (±)-3a,4,5,6,7,7a-hexahydro-3a-hydroxy-4-methylene-7a-methylindene-1,5-dione (7), through the formation of the adduct, (±)-3a,4,5,6,7,7a-hexahydro-3a-hydroxy-4-(1', 3'-diketo-2'-methylcyclopentano-2'-methylene)-7a-methylindene-1,5-dione (8), established the mechanism of the formation of the products (3 and 4)

    Gravitational Waves From Known Pulsars: Results From The Initial Detector Era

    Get PDF
    We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom

    Search for gravitational waves associated with the InterPlanetary Network short gamma ray bursts

    Full text link
    We outline the scientific motivation behind a search for gravitational waves associated with short gamma ray bursts detected by the InterPlanetary Network (IPN) during LIGO's fifth science run and Virgo's first science run. The IPN localisation of short gamma ray bursts is limited to extended error boxes of different shapes and sizes and a search on these error boxes poses a series of challenges for data analysis. We will discuss these challenges and outline the methods to optimise the search over these error boxes.Comment: Methods paper; Proceedings for Eduardo Amaldi 9 Conference on Gravitational Waves, July 2011, Cardiff, U

    Swift follow-up observations of candidate gravitational-wave transient events

    Get PDF
    We present the first multi-wavelength follow-up observations of two candidate gravitational-wave (GW) transient events recorded by LIGO and Virgo in their 2009-2010 science run. The events were selected with low latency by the network of GW detectors and their candidate sky locations were observed by the Swift observatory. Image transient detection was used to analyze the collected electromagnetic data, which were found to be consistent with background. Off-line analysis of the GW data alone has also established that the selected GW events show no evidence of an astrophysical origin; one of them is consistent with background and the other one was a test, part of a "blind injection challenge". With this work we demonstrate the feasibility of rapid follow-ups of GW transients and establish the sensitivity improvement joint electromagnetic and GW observations could bring. This is a first step toward an electromagnetic follow-up program in the regime of routine detections with the advanced GW instruments expected within this decade. In that regime multi-wavelength observations will play a significant role in completing the astrophysical identification of GW sources. We present the methods and results from this first combined analysis and discuss its implications in terms of sensitivity for the present and future instruments.Comment: Submitted for publication 2012 May 25, accepted 2012 October 25, published 2012 November 21, in ApJS, 203, 28 ( http://stacks.iop.org/0067-0049/203/28 ); 14 pages, 3 figures, 6 tables; LIGO-P1100038; Science summary at http://www.ligo.org/science/Publication-S6LVSwift/index.php ; Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p110003

    A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

    Get PDF
    We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000

    First Low-Latency LIGO+Virgo Search for Binary Inspirals and their Electromagnetic Counterparts

    Get PDF
    Aims. The detection and measurement of gravitational-waves from coalescing neutron-star binary systems is an important science goal for ground-based gravitational-wave detectors. In addition to emitting gravitational-waves at frequencies that span the most sensitive bands of the LIGO and Virgo detectors, these sources are also amongst the most likely to produce an electromagnetic counterpart to the gravitational-wave emission. A joint detection of the gravitational-wave and electromagnetic signals would provide a powerful new probe for astronomy. Methods. During the period between September 19 and October 20, 2010, the first low-latency search for gravitational-waves from binary inspirals in LIGO and Virgo data was conducted. The resulting triggers were sent to electromagnetic observatories for followup. We describe the generation and processing of the low-latency gravitational-wave triggers. The results of the electromagnetic image analysis will be described elsewhere. Results. Over the course of the science run, three gravitational-wave triggers passed all of the low-latency selection cuts. Of these, one was followed up by several of our observational partners. Analysis of the gravitational-wave data leads to an estimated false alarm rate of once every 6.4 days, falling far short of the requirement for a detection based solely on gravitational-wave data.Comment: 13 pages, 13 figures. For a repository of data used in the publication, go to: http://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=P1100065 Also see the announcement for this paper on ligo.org at: http://www.ligo.org/science/Publication-S6CBCLowLatency

    The characterization of Virgo data and its impact on gravitational-wave searches

    Get PDF
    Between 2007 and 2010 Virgo collected data in coincidence with the LIGO and GEO gravitational-wave (GW) detectors. These data have been searched for GWs emitted by cataclysmic phenomena in the universe, by non-axisymmetric rotating neutron stars or from a stochastic background in the frequency band of the detectors. The sensitivity of GW searches is limited by noise produced by the detector or its environment. It is therefore crucial to characterize the various noise sources in a GW detector. This paper reviews the Virgo detector noise sources, noise propagation, and conversion mechanisms which were identified in the three first Virgo observing runs. In many cases, these investigations allowed us to mitigate noise sources in the detector, or to selectively flag noise events and discard them from the data. We present examples from the joint LIGO-GEO-Virgo GW searches to show how well noise transients and narrow spectral lines have been identified and excluded from the Virgo data. We also discuss how detector characterization can improve the astrophysical reach of gravitational-wave searches.Comment: 50 pages, 12 figures, 5 table

    Upper limits on a stochastic gravitational-wave background using LIGO and Virgo interferometers at 600-1000 Hz

    Get PDF
    A stochastic background of gravitational waves is expected to arise from a superposition of many incoherent sources of gravitational waves, of either cosmological or astrophysical origin. This background is a target for the current generation of ground-based detectors. In this article we present the first joint search for a stochastic background using data from the LIGO and Virgo interferometers. In a frequency band of 600-1000 Hz, we obtained a 95% upper limit on the amplitude of ΩGW(f)=Ω3(f/900Hz)3\Omega_{\rm GW}(f) = \Omega_3 (f/900 \mathrm{Hz})^3, of Ω3<0.33\Omega_3 < 0.33, assuming a value of the Hubble parameter of h100=0.72h_{100}=0.72. These new limits are a factor of seven better than the previous best in this frequency band.Comment: 29 pages, 6 figures. For a repository of data used in the publication, please see https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=22210. Also see the announcement for this paper at http://www.ligo.org/science/Publication-S5VSR1StochIso
    corecore