Convective updraught evaluation in high-resolution NWP simulations using single-Doppler radar measurements

This study presents an evaluation of the size and strength of convective updraughts in high-resolution simulations by the UK Met Office Unified Model (UM). Updraught velocities have been estimated from range–height indicator (RHI) Doppler velocity measurements using the Chilbolton advanced meteorological radar, as part of the Dynamical and Microphysical Evolution of Convective Storms (DYMECS) project. Based on mass continuity and the vertical integration of the observed radial convergence, vertical velocities tend to be underestimated for convective clouds due to the undetected cross-radial convergence. Velocity fields from the UM at a resolution corresponding to the radar observations are used to scale such estimates to mitigate the inherent biases. The analysis of more than 100 observed and simulated storms indicates that the horizontal scale of updraughts in simulations tend to decrease with grid length; the 200 m grid length agreed most closely with the observations. Typical updraught mass fluxes in the 500 m grid length simulations were up to an order of magnitude greater than observed, and greater still in the 1.5 km grid length simulations. The effect of increasing the mixing length in the sub-grid turbulence scheme depends on the grid length. For the 1.5 km simulations, updraughts were weakened though their horizontal scale remained largely unchanged. Progressively more so for the sub-kilometre grid lengths, updraughts were broadened and intensified; horizontal scale was now determined by the mixing length rather than the grid length. In general, simulated updraughts were found to weaken too quickly with height. The findings were supported by the analysis of the widths of reflectivity patterns in both the simulations and observations.

Reading aloud in high schools: students and teachers across the curriculum

Reading aloud is apparently an indispensible part of teaching. Nevertheless, little is known about reading aloud across the curriculum by students and teachers in high schools. Nor do we understand teachers’ attitudes towards issues such as error correction, rehearsal time, and selecting students to read. A survey of 360 teachers in England shows that, although they have little training in reading aloud, they are extremely confident. Reading aloud by students and teachers is strongly related, and serves to further understanding rather than administrative purposes or pupils’ enjoyment. Unexpectedly, Modern Language teachers express views that set them apart from other subjects.

Aspects of particle filtering in high-dimensional spaces

Nonlinear data assimilation is high on the agenda in all fields of the geosciences as with ever increasing model resolution and inclusion of more physical (biological etc.) processes, and more complex observation operators the data-assimilation problem becomes more and more nonlinear. The suitability of particle filters to solve the nonlinear data assimilation problem in high-dimensional geophysical problems will be discussed. Several existing and new schemes will be presented and it is shown that at least one of them, the Equivalent-Weights Particle Filter, does indeed beat the curse of dimensionality and provides a way forward to solve the problem of nonlinear data assimilation in high-dimensional systems.

Antiobesity Effects of yerba mate Extract (Ilex paraguariensis) in High-fat Diet-induced Obese Mice

Because the potential of yerba mate (Ilex paraguariensis) has been suggested in the management of obesity, the aim of the present study was to evaluate the effects of yerba mate extract on weight loss, obesity-related biochemical parameters, and the regulation of adipose tissue gene expression in high-fat diet-induced obesity in mice. Thirty animals were randomly assigned to three groups. The mice were introduced to standard or high-fat diets. After 12 weeks on a high-fat diet, mice were randomly assigned according to the treatment (water or yerba mate extract 1.0 g/-kg). After treatment intervention, plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, triglyceride, low-density lipoprotein (LDL) cholesterol, and glucose were evaluated. Adipose tissue was examined to determine the mRNA levels of several genes such as tumor necrosis factor-alpha (TNF-alpha), leptin, interleukin-6 (IL-6), C-C motif chemokine ligand-2 (CCL2), CCL receptor-2 (CCR2), angiotensinogen, plasminogen activator inhibitor-1 (PAI-1), adiponectin, resistin, peroxisome proliferator-activated receptor-gamma(2) (PPAR-gamma(2)), uncoupling protein-1 (UCP1), and PPAR-gamma coactivator-1 alpha (PGC-1 alpha). The F4/80 levels were determined by immunoblotting. We found that obese mice treated with yerba mate exhibited marked attenuation of weight gain, adiposity, a decrease in epididymal fat-pad weight, and restoration of the serum levels of cholesterol, triglycerides, LDL cholesterol, and glucose. The gene and protein expression levels were directly regulated by the high-fat diet. After treatment with yerba mate extract, we observed a recovery of the expression levels. In conclusion, our data show that yerba mate extract has potent antiobesity activity in vivo. Additionally, we observed that the treatment had a modulatory effect on the expression of several genes related to obesity.

Chlorogenic acid protects paraoxonase 1 activity in high density lipoprotein from inactivation caused by physiological concentrations of hypochlorite

We hypothesized that chlorogenic acids, the main phenolics in coffee, many fruits and Ilex paraguariensis extracts, protect paraoxonase 1 activity in HDL from inactivation by chlorination at concentrations of HOCl (50 mu M) and chlorogenic acid (2-10 mu M) compatible with those found in humans. When human HDL was incubated in the presence of HOCl/OCl-, a concentration dependent loss of activity was apparent. Of interest, 5 caffeoylquinic acid at 5 mu mol/L affords more than 60% protection of the activity reaching 100% at 25 mu mol/L. This compound and the plant sources that are rich in them may be protectors of paraoxonase 1 activity. (C) 2009 Elsevier B.V. All rights reserved.

Evaluation of Mid-upper Arm Circumference in Pre-school Children: Comparison Between NCHS/CDC-2000 and WHO-2006 References

We aimed to evaluate the classification of arm circumference (AC) in pre-school children by using National Center for Health Statistics (NCHS/CDC-2000) and World Health Organization (WHO-2006) references. We evaluated 205 children: weight, height and AC were assessed and the body mass index (BMI) was calculated. The BMI values were classified into Z-scores by the WHO referential. The AC was classified into Z-cores by two references, comparing the whole-sample value and among groups (tercis) of BMI Z-score. The correlation was also evaluated between differences of AC with BMI Z-score. The WHO referential classified the AC in Z-scores greater than the NCHS/CDC, which is more specific and less sensitive than the NCHS/CDC for lean children and at the same time more sensitive and less specific for children with overweight. In conclusion, a significant difference in the AC classification occurs according to the referential used.

Oxidative stress and inflammatory mediators contribute to endothelial dysfunction in high-fat diet-induced obesity in mice

Objective We investigated the effects of high-fat diet-induced obesity on vascular proinflammatory factors and oxidative stress on endothelium-dependent relaxation of the aorta. Methods Female Swiss mice were submitted to a high-fat diet for 16 weeks. At the end of the experimental period, we evaluated blood pressure, relaxation in response to acetylcholine in aortic rings in the absence and the presence of the superoxide anion scavenger, superoxide dismutase (SOD, 150 U/ml), and the nuclear factor (NF)-kappa B inhibitor, sodium salicylate (5 mmol/l). Aortic protein expression of endothelial nitric oxide synthase, Cu/Zn-SOD, NF-kappa B, I kappa B-alpha, and proinflammatory cytokines were also evaluated. Results Obese mice presented higher systolic and diastolic blood pressure than control mice (P<0.05). The relaxation of aortas to acetylcholine, but not to sodium nitroprusside, was significantly decreased in obese mice and was corrected by both SOD and sodium salicylate (P<0.05). The protein expression of endothelial nitric oxide synthase and Cu/Zn-SOD was significantly decreased in aorta from obese mice (P<0.05). Total p65 NF-kappa B subunit protein expression was not affected by obesity, but the protein expression of NF-kappa B inhibitor I kappa B-alpha was lower in aorta from obese mice (P<0.05). There were no significant differences in the interleukin (IL)-1 beta and IL-6 protein expression between groups. In contrast, the expression of TNF-alpha was significantly increased in aortas from obese mice. Conclusion Our resultssuggest that the reducedantioxidant defense and the local NF-kappa B pathway play an important role in the impairment of endothelium-dependent relaxation in aorta from obese mice. J Hypertens 28: 2111-2119 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

Antihyperon polarization in high-energy inclusive processes

We propose a model for the antihyperon polarization in high-energy proton-nucleus inclusive reactions, based on the final-state interactions between the antihyperons and other produced particles (predominantly pions). To formulate this idea, we use the previously obtained low-energy pion-(anti-)hyperon interaction using effective chiral Lagrangians, and a hydrodynamic parametrization of the background matter, which expands and decouples at a certain freezeout temperature.

EXACT AND APPROXIMATE RELATIONS FOR THE SPIN-DEPENDENCE OF THE EXCHANGE ENERGY IN HIGH MAGNETIC FIELDS

The exchange energy of an arbitrary collinear-spin many-body system in an external magnetic field is a functional of the spin-resolved charge and current densities, E(x)[n(up arrow), n(down arrow), j(up arrow), j(down arrow)]. Within the framework of density-functional theory (DFT), we show that the dependence of this functional on the four densities can be fully reconstructed from either of two extreme limits: a fully polarized system or a completely unpolarized system. Reconstruction from the limit of an unpolarized system yields a generalization of the Oliver-Perdew spin scaling relations from spin-DFT to current-DFT. Reconstruction from the limit of a fully polarized system is used to derive the high-field form of the local-spin-density approximation to current-DFT and to magnetic-field DFT.

Removal of phenol in high salinity media by a hybrid process (activated sludge plus photocatalysis)

The degradation of phenol by a hybrid process (activated sludge + photocatalysis) in a high salinity medium (50 g L-1 of chloride) has been investigated. The sludge used from a municipal wastewater facility was adapted to the high salt concentrations prior to use. The photocatalytic conditions were optimized by means of a factorial experimental design. TiO2 P25 from Degussa was used as the photocatalyst. The initial phenol concentration was approximately 200 mg L-1 and complete removal of phenol and a mineralization degree above 98% were achieved within 25 h of treatment (24 h of biological treatment and I h of photocatalysis). From HPLC analyses, five hydroxylated intermediates formed during oxidation have been identified. The main ones were catechol and hydroquinone, followed by 1,2,4-benzenetriol, 2-hydroxy- 1,4-benzoquinone, and pyrogallol, in this order. No formation of organochlorine compounds was observed. Therefore, the proposed hybrid process showed itself to be suited to treat phenol in the presence of high contents of salt. (c) 2007 Elsevier B.V. All rights reserved.