505 research outputs found

    Wives' Labor Supply and Taxation:a Conditional Preferences Approach

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    Strong association between a single gene and fertilization efficiency of males and fecundity of their mates in the bulb mite.

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    Although variation in male fertilization efficiency has been shown to have a genetic basis in several species, the genes responsible for the effect are generally unknown. Here, we show a strong association between the fertilization success of males and their phosphogluconate dehydrogenase (Pgdh) genotype in the bulb mite Rhizoglyphus robini. Males homozygous for the slow (S) allele fathered a significantly greater proportion of offspring when competing with males homozygous for the fast (F) allele. There was no evidence that female fecundity was influenced by their Pgdh genotype. The fecundity of FF females did not differ significantly from the fecundity of SS females but female fecundity was significantly influenced by the genotype of their mate. Females paired with SS males laid significantly fewer eggs than females paired with FF males. Altogether these data show a trade-off, with the male SS genotype associated with their higher fertilization efficiency but at the cost of a negative impact on the fecundity of females mating with them

    Structure of the UspA1 protein fragment from Moraxella catarrhalis responsible for C3d binding

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    The gram-negative bacterium Moraxella catarrhalis infects humans exclusively, causing various respiratory tract diseases, including acute otitis media in children, septicaemia or meningitis in adults, and pneumonia in the elderly. To do so, M. catarrhalis expresses virulence factors facilitating its entry and survival in the host. Among them are the ubiquitous surface proteins (Usps): A1, A2, and A2H, which all belong to the trimeric autotransporter adhesin family. They bind extracellular matrix molecules and inhibit the classical and alternative pathways of the complement cascade by recruiting complement regulators C3d and C4b binding protein. Here, we report the 2.5 Å resolution X-ray structure of UspA1299-452, which previous work had suggested contained the canonical C3d binding site found in both UspA1 and UspA2. We show that this fragment of the passenger domain contains part of the long neck domain (residues 299 – 336) and a fragment of the stalk (residues 337 – 452). The coiled-coil stalk is left-handed, with 7 polar residues from each chain facing the core and coordinating chloride ions or water molecules. Despite the previous reports of tight binding in serum-based assays, we were not able to demonstrate binding between C3d and UspA1299-452 using ELISA or biolayer interferometry, and the two proteins run separately on size-exclusion chromatography. Microscale thermophoresis suggested that the dissociation constant was 140.5 ± 8.4 μM. We therefore suggest that full-length proteins or other additional factors are important in UspA1-C3d interactions. Other molecules on the bacterial surface or present in serum may enhance binding of those two molecules.Peer reviewe

    Text messaging and brief phone calls for weight loss in overweight and obese English- and Spanish-speaking adults: A 1-year, parallel-group, randomized controlled trial.

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    BACKGROUND:Weight loss interventions based solely on text messaging (short message service [SMS]) have been shown to be modestly effective for short periods of time and in some populations, but limited evidence is available for positive longer-term outcomes and for efficacy in Hispanic populations. Also, little is known about the comparative efficacy of weight loss interventions that use SMS coupled with brief, technology-mediated contact with health coaches, an important issue when considering the scalability and cost of interventions. We examined the efficacy of a 1-year intervention designed to reduce weight among overweight and obese English- and Spanish-speaking adults via SMS alone (ConTxt) or in combination with brief, monthly health-coaching calls. ConTxt offered 2-4 SMS/day that were personalized, tailored, and interactive. Content was theory- and evidence-based and focused on reducing energy intake and increasing energy expenditure. Monthly health-coaching calls (5-10 minutes' duration) focused on goal-setting, identifying barriers to achieving goals, and self-monitoring. METHODS AND FINDINGS:English- and Spanish-speaking adults were recruited from October 2011 to March 2013. A total of 298 overweight (body mass index [BMI] 27.0 to 39.9 kg/m2) adults (aged 21-60 years; 77% female; 41% Hispanic; 21% primarily Spanish speaking; 44% college graduates or higher; 22% unemployed) were randomly assigned (1:1) to receive either ConTxt only (n = 101), ConTxt plus health-coaching calls (n = 96), or standard print materials on weight reduction (control group, n = 101). We used computer-based permuted-block randomization with block sizes of three or six, stratified by sex and Spanish-speaking status. Participants, study staff, and investigators were masked until the intervention was assigned. The primary outcome was objectively measured percent of weight loss from baseline at 12 months. Differences between groups were evaluated using linear mixed-effects regression within an intention-to-treat framework. A total of 261 (87.2%) and 253 (84.9%) participants completed 6- and 12-month visits, respectively. Loss to follow-up did not differ by study group. Mean (95% confidence intervals [CIs]) percent weight loss at 12 months was -0.61 (-1.99 to 0.77) in the control group, -1.68 (-3.08 to -0.27) in ConTxt only, and -3.63 (-5.05 to -2.81) in ConTxt plus health-coaching calls. At 12 months, mean (95% CI) percent weight loss, adjusted for baseline BMI, was significantly different between ConTxt plus health-coaching calls and the control group (-3.0 [-4.99 to -1.04], p = 0.003) but not between the ConTxt-only and the control group (-1.07 [-3.05 to 0.92], p = 0.291). Differences between ConTxt plus health-coaching calls and ConTxt only were not significant (-1.95 [-3.96 to 0.06], p = 0.057). These findings were consistent across other weight-related secondary outcomes, including changes in absolute weight, BMI, and percent body fat at 12 months. Exploratory subgroup analyses suggested that Spanish speakers responded more favorably to ConTxt plus health-coaching calls than English speakers (Spanish contrast: -7.90 [-11.94 to -3.86], p < 0.001; English contrast: -1.82 [-4.03 to 0.39], p = 0.107). Limitations include the unblinded delivery of the intervention and recruitment of a predominantly female sample from a single site. CONCLUSIONS:A 1-year intervention that delivered theory- and evidence-based weight loss content via daily personalized, tailored, and interactive SMS was most effective when combined with brief, monthly phone calls. TRIAL REGISTRATION:ClinicalTrials.gov NCT01171586

    Imaging with extended focal depth by means of the refractive light sword optical element

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    The paper presents first experiments with a refractive light sword optical element (LSOE). A refractive version of the LSOE was prepared in photoresist by gray scale photolithography. Then we examined chromatic aberrations of the produced element and compared them with those corresponding to two different lenses. For this purpose we performed two experiments, the first one where white light illumination was used and the latter one by the help of monochromatic illumination with three different wavelengths. The obtained results lead to the conclusion that the refractive LSOE does not exhibit significant chromatic aberrations and can be successfully used for imaging with extended depth of focus in polychromatic illuminationThis work was supported by Warsaw University of Technology, by National Institute of Telecommunications and by the Spanish Ministerio de Educación y Ciencia, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+i), grant FIS2005-05020- C03-02 and FEDERS

    Imaging properties of the light sword optical element used as a contact lens in a presbyopic eye model

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    The paper analyzes the imaging properties of the light sword optical element (LSOE) applied as a contact lens to the presbyopic human eye. We performed our studies with a human eye model based on the Gullstrand parameterization. In order to quantify the discussion concerning imaging with extended depth of focus, we introduced quantitative parameters characterizing output images of optotypes obtained in numerical simulations. The quality of the images formed by the LSOE were compared with those created by a presbyopic human eye, reading glasses and a quartic inverse axicon. Then we complemented the numerical results by an experiment where a 3D scene was imaged by means of the refractive LSOE correcting an artificial eye based on the Gullstrand model. According to performed simulations and experiments the LSOE exhibits abilities for presbyopia correction in a wide range of functional vision distances.This work was supported by the Polish Ministry of Science and Higher Education under grant N N 514 149038 and by the Spanish Ministerio de Ciencia e Innovación (MICINN), grant FIS2008-03884 with complementary support from the European Social Fund implemented under the Human Capital Programme (POKL), project, “Preparation and Realization of Medical Physics Specialty.”S

    Strehl ratios characterizing optical elements designed for presbyopia compensation

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    We present results of numerical analysis of the Strehl ratio characteristics for the light sword optical element (LSOE). For comparison there were analyzed other optical imaging elements proposed for compensation of presbyopia such as the bifocal lens, the trifocal lens, the stenopeic contact lens, and elements with extended depth of focus (EDOF), such as the logarithmic and quartic axicons. The simulations were based on a human eye’s model being a simplified version of the Gullstrand model. The results obtained allow to state that the LSOE exhibits much more uniform characteristics of the Strehl ratio comparing with other known hitherto elements and therefore it could be a promising aid to compensate for the insufficient accommodation range of the human eye.This work was supported by the Polish Ministry of Science and Higher Education under grants N N 514 149038 and N N 518 378237 as well as by the European Social Fund implemented under the Human Capital Operational Programme (POKL), project: “Preparation and Realization of Medical Physics Specialty” with complementary support from the Spanish Ministerio de Ciencia e Innovación (MICINN) grant FIS2008-03884S

    The oxidizing power of the dark side: Rapid nocturnal aging of biomass burning as an overlooked source of oxidized organic aerosol

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    Oxidized organic aerosol (OOA) is a major component of ambient particulate matter, substantially affecting both climate and human health. A considerable body of evidence has established that OOA is readily produced in the presence of daylight, thus leading to the association of high concentrations of OOA in the summer or mid-afternoon. However, this current mechanistic understanding fails to explain elevated OOA concentrations during night or wintertime periods of low photochemical activity, thus leading atmospheric models to under predict OOA concentrations by a factor of 3-5. Here we show that fresh emissions from biomass burning rapidly forms OOA in the laboratory over a few hours and without any sunlight. The resulting OOA chemical composition is consistent with the observed OOA in field studies in major urban areas. To estimate the contribution of nocturnally aged OOA in the ambient atmosphere, we incorporate this nighttime-aging mechanism into a chemical-transport model and find that over much of the United States greater than 75% of the OOA formed from fresh biomass burning emissions underwent nighttime aging processes. Thus, the conceptual framework that OOA is predominantly formed in the presence of daylight fails to account for a substantial and rapid oxidation process occurring in the dark
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