56 research outputs found
LIPID PEROXIDATION AND ANTIOXIDANT STATUS: A COMPARISON BETWEEN MIDDLE AGED AND ELDERLY POPULATION
Objective : In recent years a large body of experimental research indicates that oxidative stress and antioxidant defenses are related to processes ĂÂ 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) ĂÂ by measuring Thiobarbituric Acid Reactive substances (TBARs) for lipidĂÂ peroxidation vis-ĂÂ -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 ĂÂ 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.
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:ĂÂ 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. ĂÂ Main outcome measures: Serum Creatine Phosphokinase ĂÂ and ĂÂ Nitrate-Nitrite ratio (Surrogate marker of nitric oxide)ĂÂ 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). ĂÂ Significant amount of ĂÂ 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 studiedĂÂ young population.Keywords: sub maximal exercise, activity energy expenditure, nitrate-nitrite ratio
Plasmodium falciparum uses gC1qR/HABP1/p32 as a receptor to bind to vascular endothelium and for platelet-mediated clumping
The ability of Plasmodium falciparum-infected red blood cells (IRBCs) to bind to vascular endothelium, thus enabling sequestration in vital host organs, is an important pathogenic mechanism in malaria. Adhesion of P. falciparum IRBCs to platelets, which results in the formation of IRBC clumps, is another cytoadherence phenomenon that is associated with severe disease. Here, we have used in vitro cytoadherence assays to demonstrate, to our knowledge for the first time, that P. falciparum IRBCs use the 32-<Da human protein gC1qR/HABP1/p32 as a receptor to bind to human brain microvascular endothelial cells. In addition, we show that P. falciparum IRBCs can also bind to gC1qR/HABP1/p32 on platelets to form clumps. Our study has thus identified a novel host receptor that is used for both adhesion to vascular endothelium and platelet-mediated clumping. Given the association of adhesion to vascular endothelium and platelet-mediated clumping with severe disease, adhesion to gC1qR/HABP1/p32 by P. falciparum IRBCs may play an important role in malaria pathogenesis
The homeodomain transcriptional regulator DVE-1 directs a program for synapse elimination during circuit remodeling
The elimination of synapses during circuit remodeling is critical for brain maturation; however, the molecular mechanisms directing synapse elimination and its timing remain elusive. We show that the transcriptional regulator DVE-1, which shares homology with special AT-rich sequence-binding (SATB) family members previously implicated in human neurodevelopmental disorders, directs the elimination of juvenile synaptic inputs onto remodeling C. elegans GABAergic neurons. Juvenile acetylcholine receptor clusters and apposing presynaptic sites are eliminated during the maturation of wild-type GABAergic neurons but persist into adulthood in dve-1 mutants, producing heightened motor connectivity. DVE-1 localization to GABAergic nuclei is required for synapse elimination, consistent with DVE-1 regulation of transcription. Pathway analysis of putative DVE-1 target genes, proteasome inhibitor, and genetic experiments implicate the ubiquitin-proteasome system in synapse elimination. Together, our findings define a previously unappreciated role for a SATB family member in directing synapse elimination during circuit remodeling, likely through transcriptional regulation of protein degradation processes.<br/
A review on the two-phase pressure drop characteristics in helically coiled tubes
Due to their compact design, ease of manufacture and enhanced heat transfer and fluid mixing properties, helically coiled tubes are widely used in a variety of industries and applications. In fact, helical tubes are the most popular from the family of coiled tube heat exchangers. This review summarises and critically reviews the studies reported in the pertinent literature on the pressure drop characteristics of two-phase flow in helically coiled tubes. The main findings and correlations for the frictional two-phase pressure drops due to: steam-water flow boiling, R-134a evaporation and condensation, air-water two-phase flow and nanofluid flows are reviewed. Therefore, the purpose of this study is to provide researchers in academia and industry with a practical summary of the relevant correlations and supporting theory for the calculation of the two-phase pressure drop in helically coiled tubes. A significant scope for further research was also identified in the fields of: air-water bubbly flow and nanofluid two phase and three-phase flows in helically coiled tubes
Search for gravitational waves associated with the InterPlanetary Network short gamma ray bursts
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
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
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
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
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