1,689 research outputs found
Short-term therapy with rosiglitatzone, a PPAR-¿ agonist improves metabolic profile and vascular function in non-obese lean wistar rats
A number of preclinical and clinical studies have reported blood-pressure-lowering benefits of thiazolidinediones in diabetic subjects and animal models of diabetes. This study was designed to further elucidate vascular effects of rosiglitazone, on healthy nonobese, lean animals. Adult male Wistar rats were randomized and assigned to control and rosiglitazone-treated groups and were dosed daily with either vehicle or rosiglitazone (10 mg kg(−1) day(−1)) by oral gavage for 5 days. Compared with control group, rosiglitazone treatment significantly reduced plasma levels of triglycerides (>240%) and nonesterified free fatty acids (>268%) (both, P < 0.001). There were no changes in vascular contractility to KCl or noradrenaline between two groups. However, rosiglitazone therapy improved carbamylcholine-induced vasorelaxation (93 ± 3 % versus control 78 ± 2, P < 0.01) an effect which was abolished by L-NAME. There was no difference in sodium nitroprusside-induced vasorelaxation between the control and rosiglitazone-treated animals. These results indicate that short-term rosiglitazone therapy improves both metabolic profile and vascular function in lean rats. The vascular effect of rosiglitazone appears to be mediated by alteration in NO production possibly by activation of endothelial PPARγ. This increased NO production together with improved lipid profile may explain mechanism(s) of blood-pressure-lowering effects of thiazolidinediones on both human and experimental animals
Optimisation of quantum Monte Carlo wave function: steepest descent method
We have employed the steepest descent method to optimise the variational
ground state quantum Monte Carlo wave function for He, Li, Be, B and C atoms.
We have used both the direct energy minimisation and the variance minimisation
approaches. Our calculations show that in spite of receiving insufficient
attention, the steepest descent method can successfully minimise the wave
function. All the derivatives of the trial wave function respect to spatial
coordinates and variational parameters have been computed analytically. Our
ground state energies are in a very good agreement with those obtained with
diffusion quantum Monte Carlo method (DMC) and the exact results.Comment: 13 pages, 3 eps figure
Frequency-Doubling of Femtosecond Pulses in “Thick” Nonlinear Crystals With Different Temporal and Spatial Walk-Off Parameters
We present a comparative study on frequency-doubling characteristics of femtosecond
laser pulses in thick nonlinear crystals with different temporal and spatial walk-off
parameters. Using single-pass second harmonic generation (SHG) of 260 fs pulses at
1064 nm from a high-average-power femtosecond Yb-fiber laser in 5-mm-long crystals of
β-BaB2O4 (BBO) and BiB3O6 (BIBO), we find that for comparable values of temporal and
spatial walk-off parameters in each crystal, the optimum focusing condition for SHG is more
strongly influenced by spatial walk-off than temporal walk-off. It is also observed that under
such conditions, the Boyd and Kleinman theory commonly used to define the optimum focusing
condition for frequency-doubling of cw and long-pulse lasers is also valid for SHG
of ultrafast lasers. We also investigate the effect of focusing on the spectral, temporal, and
spatial characteristics of the second harmonic (SH) radiation, as well as angular acceptance
bandwidth for the SHG process, under different temporal and spatial walk-off conditions in
the two crystalsPeer ReviewedPostprint (author's final draft
Hump on upper shelf of ductile-brittle transition temperature curve of a plain carbon steel
The ductile—brittle transition temperature (DBTT) in a plain carbon steel has been studied in a series of Charpy V notch samples. Both non-standard and standard samples were used in the as drawn, normalised and annealed conditions. In all cases, a hump was recorded on the upper shelf of the DBTT. Examination of fractures in the SEM in the vicinity of the hump showed typical microvoid coalescence. Low temperature fractures showed classical cleavage fractures with river markings. In the normalised and annealed conditions, both yield stress σy and impact transition temperature Tc varied inversely with square root of the ferrite grain size, in agreement with previous workers. However, the points for ‘as drawn’ samples lay off the linear plot. The reasons for this are discussed. The hump on the upper shelf of the DBTT is thought to be associated with dynamic strain aging
Standard of knowledge about their disease among patients with diabetes in Karachi, Pakistan
Objective: The aim of this study was to determine the standard of knowledge among people with diabetes.METHOD: Two hundred and thirty patients were randomly chosen from outpatient clinics and a 34-item multiple choice questionnaire administered to them. The questionnaire was structured to assess knowledge about the disease state, diagnostic tests, complications and management.Results: The average score of correct answers for the group was 40%. A significantly higher score correlated with younger age (16-30 years), educational status and regular follow-up with a diabetic clinic. There was no significant difference in the knowledge score between males and females or between those on oral hypoglycemic agents (OHA) and insulin. Fifty percent of the patients could correctly answers questions regarding food and nutrition and only 60% were aware of target blood glucose levels for optimal control. It was alarming to learn that 75% of those on insulin did not know that using U-40 or U-100 insulin does not change the dose required.CONCLUSION: The study emphasizes the need for diabetes education at all levels, both for the patients as well as the health care providers to counter the pandemic of diabetes-related complications globally
Vehicular traffic flow at an intersection with the possibility of turning
We have developed a Nagel-Schreckenberg cellular automata model for
describing of vehicular traffic flow at a single intersection. A set of traffic
lights operating in fixed-time scheme controls the traffic flow. Open boundary
condition is applied to the streets each of which conduct a uni-directional
flow. Streets are single-lane and cars can turn upon reaching to the
intersection with prescribed probabilities. Extensive Monte Carlo simulations
are carried out to find the model flow characteristics. In particular, we
investigate the flows dependence on the signalisation parameters, turning
probabilities and input rates. It is shown that for each set of parameters,
there exist a plateau region inside which the total outflow from the
intersection remains almost constant. We also compute total waiting time of
vehicles per cycle behind red lights for various control parameters.Comment: 8 pages, 17 eps figures, Late
Program Performance and Multiple Constituency Theory
This paper seeks to deepen our understanding of performance measurement in the nonprofit human services sector by investigating issues related to funder and provider motivations for collecting and analyzing program level performance information. Using survey and interview data from nonprofit human service organizations and their funders (nonprofit and local government), we analyze this study’s research questions through the lens of multiple constituency theory. Consistent with multiple constituency theory, the study found similarities and differences in funder and provider motivations for collecting performance information. The study also indicates other key constituents (such as service beneficiaries, donors to nonprofit organizations and other levels of government that provide resources to local governments) play a role in defining program performance. The paper suggests that multiple constituency theory applies to program level performance and that understanding program performance requires considering the perspectives of multiple stakeholders
Semiclassical Strings Probing NS5 Brane Wrapped on S^5
We study little string theory on R^1 x S^5, defined by a theory which lives
on type IIA N NS5 branes wrapped on S^5, using its supergravity dual. In
particular we study semiclassical rotating closed strings in this background.
We also consider Penrose limit of this background that leads to a plane wave on
which string theory is exactly solvable.Comment: 14 pages, Latex, v2: typos corrected, Refs. added, v3: typos
correcte
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