427 research outputs found

    Associations Between Visceral Adipose Tissue Estimates Produced By Near-Infrared Spectroscopy, Mobile Anthropometrics, and Traditional Body Composition Assessments and Estimates Derived From Dual-Energy X-Ray Absorptiometry

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    Assessments of visceral adipose tissue (VAT) are critical in preventing metabolic disorders; however, there are limited measurement methods that are accurate and accessible for VAT. The purpose of this cross-sectional study was to evaluate the association between VAT estimates from consumer-grade devices and traditional anthropometrics and VAT and subcutaneous adipose tissue (SAT) from dual-energy X-ray absorptiometry (DXA). Data were collected from 182 participants (female = 114; White = 127; Black/African-American (BAA) = 48) which included anthropometrics and indices of VAT produced by near-infrared reactance spectroscopy (NIRS), visual body composition (VBC) and multifrequency BIA (MFBIA). VAT and SAT were collected using DXA. Bivariate and partial correlations were calculated between DXAVAT and DXASAT and other VAT estimates. All VAT indices had positive moderate–strong correlations with VAT (all P \u3c 0·001) and SAT (all P \u3c 0·001). Only waist:hip (r = 0·69), VATVBC (r = 0·84), and VATMFBIA (r = 0·86) had stronger associations with VAT than SAT (P \u3c 0·001). Partial associations between VATVBC and VATMFBIA were only stronger for VAT than SAT in White participants (r = 0·67, P \u3c 0·001) but not female, male, or BAA participants individually. Partial correlations for waist:hip were stronger for VAT than SAT, but only for male (r = 0·40, P \u3c 0·010) or White participants (r = 0·48, P \u3c 0·001). NIRS was amongst the weakest predictors of VAT which was highest in male participants (r = 0·39, P \u3c 0·010) but non-existent in BAA participants (r = –0·02, P \u3e 0·050) after adjusting for SAT. Both anthropometric and consumer-grade VAT indices are consistently better predictors of SAT than VAT. These data highlight the need for a standardised, but convenient, VAT estimation protocol that can account for the relationship between SAT and VAT that differs by sex/race

    Mining microbial genomes for new natural products and biosynthetic pathways

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    Analyses of microbial genome sequences have revealed numerous examples of ‘cryptic’ or ‘orphan’ biosynthetic gene clusters, with the potential to direct the production of novel, structurally complex natural products. This article summarizes the various methods that have been developed for discovering the products of cryptic biosynthetic gene clusters in microbes and gives an account of my group's discovery of the products of two such gene clusters in the model actinomycete Streptomyces coelicolor M145. These discoveries hint at new mechanisms, roles and specificities for natural product biosynthetic enzymes. Our efforts to elucidate these are described. The identification of new secondary metabolites of S. coelicolor raises the question: what is their biological function? Progress towards answering this question is also summarized

    Contemporary Africa through the theory of Louis Dumont

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    Abstract This article responds to a trend in recent anthropological scholarship in Africa that has overemphasized a lack of social organization following the advancement of neoliberal reforms across the continent. Using a theoretical framework informed by the theory of Louis Dumont, I show that social organization remains an important analytical topic in times of crisis, and that this is best apprehended through an analysis of values. The ethnographic focus of this article is Pentecostal Christianity as it is practiced on the Zambian Copperbelt. In this particular African context, Pentecostalism is animated by an overarching value that I call "moving," which is in turn made up to two sub-values: charisma and prosperity. By exploring how Pentecostal believers navigate the hierarchical relationship between these two sub-values, we are given a clear picture of the social world that Pentecostal adherence makes possible

    Marine stratocumulus aerosol-cloud relationships in the MASE-II experiment: Precipitation susceptibility in eastern Pacific marine stratocumulus

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    Observational data on aerosol-cloud-drizzle relationships in marine stratocumulus are presented from the second Marine Stratus/Stratocumulus Experiment (MASE-II) carried out in July 2007 over the eastern Pacific near Monterey, California. Observations, carried out in regions of essentially uniform meteorology with localized aerosol enhancements due to ship exhaust (“ship tracks”), demonstrate, in accord with those from numerous other field campaigns, that increased cloud drop number concentration Nc and decreased cloud top effective radius r_e are associated with increased subcloud aerosol concentration. Modulation of drizzle by variations in aerosol levels is levels is clearly evident. Variations of cloud base drizzle rate R_(cb) are found to be consistent with the proportionality, R_(cb) / H^3/N_c, where H is cloud depth. Simultaneous aircraft and A-Train satellite observations are used to quantify the precipitation susceptibility of clouds to aerosol perturbations in the eastern Pacific region

    On the Northern Annular Mode Surface Signal Associated with Stratospheric Variability

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    The wintertime northern annular mode (NAM) at the surface is known to undergo slow intraseasonal variations in association with stratospheric variability, which leads the surface signal by up to several weeks. The relative contributions, however, of potentially relevant stratosphere–troposphere coupling mechanisms are not yet fully understood. In this study the relative roles of (i) the downward effect of the zonal-mean secondary circulation induced by quasigeostrophic (QG) adjustment to stratospheric wave drag and radiative damping and (ii) wave drag local to the troposphere are estimated. For this purpose, a spectral tendency equation of the QG zonal-mean zonal wind is derived and used, in a first step, to obtain the external mechanical forcing that, in the QG framework, drives exactly the observed stratospheric and tropospheric daily NAM. In a second step, the equation is then integrated in time to reconstruct the daily NAM, but with the forcing restricted to either stratospheric or tropospheric levels, each case leaving a characteristic NAM surface signal. The relative roles of the above-mentioned mechanisms are found to be of similar quantitative importance, but to differ in a qualitative sense. The downward effect of stratospheric QG adjustment is responsible for the initiation of the NAM surface signal, whereas subsequently local tropospheric wave drag actively maintains and persists the signal over several weeks. Furthermore, the downward effect of QG adjustment to stratospheric radiative damping is shown to have only a minor impact, compared to that from stratospheric wave drag. The robustness of these conclusions is demonstrated by a sensitivity study with respect to various model parameters

    Clinical Results of Atticoantrotomy with Attic Reconstruction or Attic Obliteration for Patients with an Attic Cholesteatoma

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    ObjectivesWe aimed to investigate the clinical results of atticoantrotomy in patients with an attic cholesteatoma.MethodsNinety-eight ears in 98 patients were operated on using atticoantrotomy between October 2002 and December 2006. A retrospective review of the otology database (operative findings and methods, postoperative physical examination and pre- and postoperative audiometry) was performed.ResultsThere were 58 female and 40 male patients with a mean age of 40 yr. The cholesteatoma was limited to the attic region in 24 patients (24.5%); attic with antrum in 18 (18.4%); and attic with antrum and middle ear in 56 (57.1%). Attic obliteration was performed in 59 patients (60.2%), attic reconstruction in 39 (39.8%) and ossicular reconstruction was performed in 59 (60.2%). The mean preoperative and postoperative air-bone gaps were 29.2±13.5 dB and 25.0±15.4 dB, respectively (P=0.01) and the mean preoperative and postoperative high-tone bone conduction levels were 14.5±9.7 dB and 15.23±14.0 dB, respectively (P=0.411). A recurrent cholesteatoma was detected in 3 ears (3%) and revision surgery was performed on these patients.ConclusionAtticoantrotomy showed a low recurrence rate and no deterioration in hearing levels. If there is a intact malleus head or body of incus, attic reconstruction was possible and this procedure could lead to improved hearing. However, postoperative retraction occurred in 18% of patients, a problem that will need to be solved in the future

    Multimodel climate and variability of the stratosphere

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    The stratospheric climate and variability from simulations of sixteen chemistry‐climate models is evaluated. On average the polar night jet is well reproduced though its variability is less well reproduced with a large spread between models. Polar temperature biases are less than 5 K except in the Southern Hemisphere (SH) lower stratosphere in spring. The accumulated area of low temperatures responsible for polar stratospheric cloud formation is accurately reproduced for the Antarctic but underestimated for the Arctic. The shape and position of the polar vortex is well simulated, as is the tropical upwelling in the lower stratosphere. There is a wide model spread in the frequency of major sudden stratospheric warnings (SSWs), late biases in the breakup of the SH vortex, and a weak annual cycle in the zonal wind in the tropical upper stratosphere. Quantitatively, “metrics” indicate a wide spread in model performance for most diagnostics with systematic biases in many, and poorer performance in the SH than in the Northern Hemisphere (NH). Correlations were found in the SH between errors in the final warming, polar temperatures, the leading mode of variability, and jet strength, and in the NH between errors in polar temperatures, frequency of major SSWs, and jet strength. Models with a stronger QBO have stronger tropical upwelling and a colder NH vortex. Both the qualitative and quantitative analysis indicate a number of common and long‐standing model problems, particularly related to the simulation of the SH and stratospheric variability
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