Backscattering of Ultrasonic Leaky Waves from Liquid-Solid Interfaces

It is well known that when a finite ultrasonic beam of a given spatial distribution is incident at the Rayleigh angle to a liquid-solid interface, the spatial distribution of the reflected field may be altered significantly. The “energy redistribution” is due to the interference between the specularly reflected beam and a surface wave which has leaked back to the water. The “shape” of the reflected field depends on the so-called Schoch displacement (which is characteristic of the interface) and on the width of the ultrasonic beam. It has also been observed that significant energy is scattered back to the transmitter at the Rayleigh angle. Experimental results will be presented on the evaluation of the parameters effecting the back-scattered amplitude. The backscattered Rayleigh angle phenomena are also applied to measured surface wave velocities of anisotropic materials such as casts and welds

25-Hydroxyvitamin D Threshold for the Effects of Vitamin D Supplements on Bone Density:Secondary Analysis of a Randomized Controlled Trial

Most trials of vitamin D supplementation have shown no benefits on bone density (BMD), though severe vitamin D deficiency causes osteomalacia which is associated with profound BMD deficits. Recently, the ViDA-BMD study from New Zealand demonstrated a threshold of baseline 25-hydroxyvitamin D (30 nmol/L) below which vitamin D supplementation did benefit BMD. We have now re-examined data from a similar trial in Aberdeen to determine whether a baseline 25-hydroxyvitamin D threshold of 30 nmol/L is also observed in that database. The Aberdeen study recruited 305 postmenopausal women in late winter and randomized them to receive placebo, vitamin D 400 IU/day or vitamin D 1000 IU/day over one year. As previously reported, BMD loss at the hip was reduced by vitamin D 1000 IU/day only, and there was no significant treatment effect of either dose at the lumbar spine. In the present analysis, when the trial participants were grouped according to whether their baseline 25-hydroxyvitamin D was ≤30 nmol/L or above this threshold, significant treatment effects were apparent at both the spine and hip in those with baseline 25-hydroxyvitamin D ≤30 nmol/L, but no significant effects were apparent in those with baseline 25-hydroxyvitamin D above this level. There was evidence of a similar threshold for effects on parathyroid hormone, but no groups showed changes in bone turnover markers during the study. It is concluded that vitamin D supplements only increase bone density in adults with nadir 25-hydroxyvitamin D ≤30 nmol/L. This moves us further towards a trial-based definition of vitamin D deficiency in adults with adequate calcium intakes, and suggests that supplement use should be targeted accordingly. Future trials of vitamin D supplementation should focus on individuals with 25-hydroxyvitamin D concentrations in this range

Suplementacao energetica e energetico-proteica para vacas em lactacao durante a epoca da seca.

bitstream/item/90984/1/CT-08-Suplementacao-energetica.pd

Comparative evaluation of Fungitest, Neosensitabs and broth microdilution method for yeasts susceptibility testing

The need of a simple and reliable method for routine yeasts susceptibility testing led us to evaluate two commercially available methods. We investigated the in vitro susceptibility of 67 clinical isolates (26 C. albicans, 32 C. glabrata, 4 C. krusei, 2 C. tropicalis, 2 C. kefyr and 1 S. cerevisiae) to 6 drugs flucytosine (FC), amphotericin B (A), fluconazole (FZ), itraconazole (IT), kétoconazole (K), miconazole (M), comparing two methods Fungitest (Sanofi Pasteur) and Neosensitabs (Rosco). A broth microdilution adaptation from the NCCLS-M27A procedure was used as reference method. Fungitests consist of individually packed 16 wells microplates containing 6 drugs at two critical concentrations in buffered medium. Reading was performed after 24 and 48h incubation. Neosensitabs is an agar diffusion method on Shadomy agar using antifungals tablets. Reading was performed after 24h. For all strains Neosensitabs was in concordance with NCCLS M27-A for FC (94%), A (98%), FZ (55%) I (53%) with p<0.05. Fungitest correlated with NCCLS method for all antifungals after 24 and 48h incubation time (p<0.05) with respectively 95/95% for FC, 100/100% for A, 80/76% for FZ, 81/55% for I and 93/75% for K, and 88/81 for M. Candida glabrata gave the poorest result with Neosensitabs with 28% concordance for FZand 39% for I; therefore the method can't be recommended for this species. Fungitest concordance observed was 55% for I after 48h. Our results suggest that Fungitest is appropriate for routine yeast susceptibility testing. However itraconazole testing has to be improved with this method

Circulating 250HD, dietary vitamin D, PTH, and calcium associations with incident cardiovascular disease and mortality: The MIDSPAN Family Study

&lt;p&gt;Context: Observational studies relating circulating 25-hydroxyvitamin D (25OHD) and dietary vitamin D intake to cardiovascular disease (CVD) have reported conflicting results.&lt;/p&gt; &lt;p&gt;Objective: Our objective was to investigate the association of 25OHD, dietary vitamin D, PTH, and adjusted calcium with CVD and mortality in a Scottish cohort.&lt;/p&gt; &lt;p&gt;Design and Setting: TheMIDSPAN Family Study is a prospective study of 1040 men and 1298 women from the West of Scotland recruited in 1996 and followed up for a median 14.4 yr. Participants: Locally resident adult offspring of a general population cohort were recruited from 1972–1976.&lt;/p&gt; &lt;p&gt;Main Outcome Measures: CVD events (n &#61; 416) and all-cause mortality (n&#61;100) were evaluated.&lt;/p&gt; &lt;p&gt;Results: 25OHD was measured using liquid chromatography-tandem mass spectrometry in available plasma (n&#61;2081). Median plasma 25OHD was 18.6 ng/ml, and median vitamin D intake was 3.2 &#181; g/d (128 IU/d). Vitamin D deficiency (25OHD&#60;15 ng/ml) was present in 689 participants (33.1%). There was no evidence that dietary vitamin D intake, PTH, or adjusted calcium were associated with CVD events or with mortality. Vitamin D deficiency was not associated with CVD (fully adjusted hazard ratio&#61;1.00; 95% confidence interval&#61;0.77–1.31). Results were similar after excluding patients who reported an activity-limiting longstanding illness at baseline (18.8%) and those taking any vitamin supplements (21.7%). However, there was some evidence vitamin D deficiency was associated with all-cause mortality (fully adjusted hazard ratio&#61;2.02; 95% confidence interval&#61;1.17–3.51).&lt;/p&gt; &lt;p&gt;Conclusion: Vitamin D deficiency was not associated with risk of CVD in this cohort with very low 25OHD. Future trials of vitamin D supplementation in middle-aged cohorts should be powered to detect differences inmortality outcomes as well as CVD.(J Clin EndocrinolMetab97: 0000 –0000, 2012)&lt;/p&gt

Fish oil supplements, longevity and aging

Fish oil supplementation is of great medical and public interest with epidemiological evidence of health benefits in humans, in particular by conferring protection against heart diseases. Its anti-inflammatory properties have also been reported. Initial results from short-lived mouse strains showed that fish oil can increase lifespan, affecting pathways like inflammation and oxidation thought to be involved in the regulation of aging. Could fish oil and its omega-3 fatty acids act as geroprotectors? Probably not. A new study by Strong et al. challenges the role for fish oil supplementation in aging. Using a large cohort of genetically heterogeneous mice in three sites, part of the Interventions Testing Program of the NIA, Strong et al. show that fish oil supplementation at either low or high dosages has no effect on the lifespan of male or female mice. Although it is still possible that fish oil supplementation has health benefits for specific age-related diseases, it does not appear to slow aging or have longevity benefits

Analysis of a wild mouse promoter variant reveals a novel role for FcγRIIb in the control of the germinal center and autoimmunity.

Genetic variants of the inhibitory Fc receptor FcγRIIb have been associated with systemic lupus erythematosus in humans and mice. The mechanism by which Fcgr2b variants contribute to the development of autoimmunity is unknown and was investigated by knocking in the most commonly conserved wild mouse Fcgr2b promoter haplotype, also associated with autoimmune-prone mouse strains, into the C57BL/6 background. We found that in the absence of an AP-1-binding site in its promoter, FcγRIIb failed to be up-regulated on activated and germinal center (GC) B cells. This resulted in enhanced GC responses, increased affinity maturation, and autoantibody production. Accordingly, in the absence of FcγRIIb activation-induced up-regulation, mice developed more severe collagen-induced arthritis and spontaneous glomerular immune complex deposition. Our data highlight how natural variation in Fcgr2b drives the development of autoimmune disease. They also show how the study of such variants using a knockin approach can provide insight into immune mechanisms not possible using conventional genetic manipulation, in this case demonstrating an unexpected critical role for the activation-induced up-regulation of FcγRIIb in controlling affinity maturation, autoantibody production, and autoimmunity

Surface and subsurface changes as a result of tribocorrosion at the stem-neck interface of bi-modular prosthesis

This study presents a detailed multi-scale analysis of the degradation processes occurring on both the CoCrMo and TMZF alloy surfaces at different regions across the taper interface. Co-ordinate measurement machine, scanning electron microscopy, transmission electron microscopy and X-ray Diffraction methods have been utilised to identify the roles of degradation from the mm to nm scale. Dependant on the region of interest, varying topographies and subsurface morphologies were observed across both surfaces. In regions where high pressures are expected, retention of the surface topography was seen on the CoCrMo trunnion. This was complimented by gross shear and plastic deformation of the subsurface material. In regions where maximum penetration was seen, evidence of fretting-corrosion was seen and a loss of the nano-crystalline layer. For the TMZF surface, refinement of the alloy was seen in the top 5 μm, with fatigue cracks within the bulk present. Precipitation and formation of oxide species were observed at depths of 2 μm. The degradation of bi-modular prosthesis is a complex multifactorial process. It is hypothesised that this formation of oxide species at the interface and within the bulk alloy play an important role in the degradation through a combined work-hardening and corrosion process

Hopefulness Among Non‐U.S.‐Born Latino Youth and Young Adults

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88034/1/j.1744-6171.2011.00307.x.pd

Complex Odor from Plants under Attack: Herbivore's Enemies React to the Whole, Not Its Parts

Background: Insect herbivory induces plant odors that attract herbivores ’ natural enemies. Assuming this attraction emerges from individual compounds, genetic control over odor emission of crops may provide a rationale for manipulating the distribution of predators used for pest control. However, studies on odor perception in vertebrates and invertebrates suggest that olfactory information processing of mixtures results in odor percepts that are a synthetic whole and not a set of components that could function as recognizable individual attractants. Here, we ask if predators respond to herbivoreinduced attractants in odor mixtures or to odor mixture as a whole. Methodology/Principal Findings: We studied a system consisting of Lima bean, the herbivorous mite Tetranychus urticae and the predatory mite Phytoseiulus persimilis. We found that four herbivore-induced bean volatiles are not attractive in pure form while a fifth, methyl salicylate (MeSA), is. Several reduced mixtures deficient in one component compared to the full spider-mite induced blend were not attractive despite the presence of MeSA indicating that the predators cannot detect this component in these odor mixtures. A mixture of all five HIPV is most attractive, when offered together with the noninduced odor of Lima bean. Odors that elicit no response in their pure form were essential components of the attractive mixture. Conclusions/Significance: We conclude that the predatory mites perceive odors as a synthetic whole and that th