Experimental hut comparisons of nets treated with carbamate or pyrethroid insecticides, washed or unwashed, against pyrethroid-resistant mosquitoes.

The efficacy against mosquitoes (Diptera: Culicidae) of a bednet treated with carbamate insecticide [carbosulfan capsule suspension (CS) 200 mg/m(2)] was compared with four types of pyrethroid-treated nets in veranda-trap huts at Yaokoffikro near Bouaké, Côte d'Ivoire, where the malaria vector Anopheles gambiae Giles carries the kdr gene (conferring pyrethroid resistance) at high frequency and Culex quinquefasciatus Say is also pyrethroid resistant. Pyrethroids compared were lambdacyhalothrin CS 18 mg/m(2), alphacypermethrin water dispersible granules (WG) 20 mg/m(2), deltamethrin 50 mg/m(2) (Permanet) and permethrin emulsifiable concentrate (EC) 500 mg/m(2). Insecticidal power and personal protection from mosquito bites were assessed before and after the nets were used for 8 months and hand washed five times in cold soapy water. Before washing, all treatments except permethrin significantly reduced blood-feeding and all had significant insecticidal activity against An. gambiae. The carbosulfan net gave significantly higher killing of An. gambiae than all pyrethroid treatments except the Permanet. Against Culex spp., carbosulfan was more insecticidal and gave a significantly better protective effect than any of the pyrethroid treatments. After washing, treated nets retained various degrees of efficacy against both mosquito genera - but least for the carbosulfan net. Washed nets with three types of pyrethroid treatment (alphacypermethrin, lambdacyhalothrin, permethrin) gave significantly higher mortality rates of Culex than in huts with the same pyrethroid-treated nets before washing. After five washes, the Permanet, which is sold as a long-lasting insecticidal product, performed no better than the other nets in our experimental conditions

High serum osteopontin levels are associated with prevalent fractures and worse lipid profile in post-menopausal women with type 2 diabetes

Purpose: Patients with type 2 diabetes (T2DM) have increased fracture risk. Osteopontin (OPN) is a protein involved in bone remodeling and inflammation. The aim of this study was to evaluate the association of OPN with fracture prevalence and with metabolic parameters in post-menopausal women with T2DM. Methods: Sixty-four post-menopausal women with T2DM (age 67.0 ± 7.8 years, diabetes duration 8.9 ± 6.7 years), enrolled in a previous study, were followed up (3.6 ± 0.9 years). Previous fragility fractures were recorded. The FRAX score (without BMD) was calculated and biochemical parameters (plasma glucose, HbA1c, lipid profile and renal function) were assessed. Serum 25OH-vitamin D, calcium, PTH and OPN were evaluated at baseline. The association between OPN and fracture prevalence at baseline was evaluated by a logistic model. Results: OPN levels were higher in patients with previous fractures (n.25) than in patients without previous fractures at baseline (n.39) (p = 0.006). The odds of having fractures at baseline increased by 6.7 (1.9–31.4, 95% CI, p = 0.007) for each increase of 1 ng/ml in OPN levels, after adjustment for vitamin D and HbA1c levels. Fracture incidence was 4.7%. Higher OPN associated with a decrease in HDL-cholesterol (p = 0.048), after adjustment for age, basal HDL-cholesterol, basal and follow-up HbA1c and follow-up duration. 25OH-vitamin D associated with an increase in FRAX-estimated probability of hip fracture at follow-up (p = 0.029), after adjustment for age, 25OH-vitamin D and time. Conclusions: In post-menopausal women with T2DM, OPN might be a useful marker of fracture and worse lipid profile

Stochastic Variation of the Aero-Thermal Flow Field in a Cooled High-Pressure Transonic Vane Configuration

In transonic high-pressure turbine stages, oblique shocks originated from vane trailing edges impact the rear suction side of each adjacent vane. High-pressure vanes are usually cooled to tolerate the combustor exit temperature levels, which would reduce dramatically the residual life of a solid vane. Then, it is highly probable that shock impingement will occur in proximity of one of the coolant rows. It has already been observed that the presence of an adverse pressure gradient generates non-negligible effects on heat load due to the increase in boundary layer thickness and turbulence level, with a detrimental impact on the local adiabatic effectiveness values. Furthermore, the generation of a tornado-like vortex has been recently observed that could further decrease the efficacy of the cooling system by moving cold flow far from the vane wall. It must be also underlined that manufacturing deviations and in-service degradation are responsible for the stochastic variation of geometrical parameters. This latter phenomenon greatly alters the unsteady location of the shock impingement and the time-dependent thermal load on the vane. Present work starts from what is shown in literature and provides a highly-detailed description of the aero-thermal field that occurs on a model that represents the flow conditions occurring on the rear suction side of a cooled vane. The numerical model is initially validated against the experimental data obtained by the University of Karlsruhe during TATEF2 EU project, and then an uncertainty quantification methodology based on the probabilistic collocation method and on Padè's polynomials is used to consider the probability distribution of the geometrical parameters. The choice of aleatory unknowns allows to consider the mutual effects between shock-waves, trailing edge thickness and hole diameter. Turbulence is modelled by using the Reynolds Stress Model already implemented in ANSYS® Fluent®. Special attention is paid to the description of the flow field in the shock/boundary layer interaction region, where the presence of a secondary effects will completely change the local adiabatic effectiveness values

Oxidative stress-mediated platelet CD40 ligand upregulation in patients with hypercholesterolemia: effect of atorvastatin

Objectives: We speculated that in patients with hypercholesterolemia CD40L overexpression could depend on low-density lipoprotein (LDL)-induced enhanced intraplatelet formation of O-2(.-) and statin could reduce platelet CD40L via interference with platelet O-2(.-) production. Background: CD40L is a protein with inflammatory and thrombotic properties. CD40L is upregulated in platelets from hypercholesterolemic (HC) patients but the underlying mechanism is unclear. Methods: Collagen-induced platelet CD40L and platelet O-2(.-) expression were investigated in 40 HC patients and 40 healthy subjects. HC patients were then randomized to either a diet (n = 20) (group A) or atorvastatin 10 mg day (n = 20) (group B); the above variables were measured at baseline and after 3 and 30 days of treatment. O-2(.-) and CD40L were also measured in vitro in LDL-treated platelets with or without nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor or atorvastatin added. Results: Compared with controls, HC patients showed higher values of platelet CD40L (P < 0.001) and O-2(.-) (P < 0.001). Platelet CD40L was significantly correlated with O-2(.-) (P < 0.001). The interventional trial showed no changes in group A and a significant and parallel decrease in platelet CD40L (P < 0.001) and O-2(.-) (P < 0.001) in group B. In vitro studies demonstrated that LDL-induced platelet CD40L and GP IIb/IIIa (PAC1 binding) activation via the NADPH oxidase pathway. CD40L upregulation was counteracted by atorvastatin in a dose-dependent fashion. Conclusions: This study suggests that in patients with hypercholesterolemia platelet CD40L is upregulated via NADPH oxidase-dependent O-2(.-) generation. Atorvastatin downregulated CD40L with an oxidative stress-mediated mechanism likely involving platelet NADPH oxidase, an effect that seemed to be independent of its cholesterol-lowering action

On variational principles for coherent vortex structures

Different approaches are discussed of variational principles characterizing coherent vortex structures in two-dimensional flows. Turbulent flows seem to form ordered structures in the large scales of the motion and the self-organization principle predicts asymptotic states realizing an extremal value of the energy or a minimum of enstrophy. On the other hand the small scales take care of the increase of entropy, and asymptotic results can be obtained by applying the theory of equilibrium statistical mechanics

A Cross-Over in the Enstrophy Decay in Two-Dimensional Turbulence in a Finite Box

The numerical simulation of two-dimensional decaying turbulence in a large but finite box presented in this paper uncovered two physically different regimes of enstrophy decay. During the initial stage, the enstrophy, generated by a random Gaussian initial condition, decays as t^{-gamma} with gamma approximately 0.7-0.8. After that, the flow undergoes a transition to a gas or fluid composed of distinct vortices. Simultaneously, the magnitude of the decay exponent crosses over to gamma approximately 0.4. An exact relation for the total number of vortices, N(t), in terms of the mean circulation of an individual vortex is derived. A theory predicting that N(t) is proportional to t^{-xi} and the magnitudes of exponents gamma=2/5 and xi=4/5 is presented and the possibility of an additional very late-time cross-over to gamma=1/3 and xi=2/3 is also discussed.Comment: 11 pages, 7 figure

Acceleration-based condition monitoring of track longitudinal level using multiple regression models

In this paper, a condition monitoring system for railway track geometry is presented. The methodology has been designed for high-speed application, where the train travels at the maximum allowed speed for most of the trip. The system is designed to rely on acceleration data recorded by in-service vehicles to provide estimations of the track longitudinal level, based on pre-built regression models. It exploits synthetic indicators sampled over predefined track sections 100 m long. Different predictors are considered, computed both from acceleration data and from track geometry measured by the diagnostic train. The proposed modelling strategy allows distinguishing between isolated and distributed defects that populate the railway track as well as reproducing the evolution over time of the maximum longitudinal level registered in the considered track section; moreover, also accurate predictions of the defect amplitude are made. The results have been validated against track geometry data recorded by the diagnostic train during a monitoring period of 2 years. It is proven that the proposed system could support current maintenance strategies, providing a continuous flow of data to monitor the track infrastructure