209 research outputs found

    Small angle neutron scattering study of the step-like magnetic transformation in Pr0.70Ca0.30MnO3

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    Small angle neutron scattering (SANS) magnetic and electrical transport measurements were performed to study a single crystal of Pr0.7Ca0.3MnO3, a colossal magnetoresistive (CMR) material. While the magnetic field induced transformation of this phase separated compound consisting of an antiferromagnetic insulating phase (AFI) and a ferromagnetic insulating phase (FI), is continuous at high temperature (above 5K), at lower temperature a step like transformation is observed (around 5T at 2K). Macroscopic magnetization measurements and SANS indicate that this transformation occurs by the formation of mesoscopic ferromagnetic metallic (FM) domains in the AFI phase, and, eventually, in the FI phase. Although above 5K this transformation is continuous, below 5K a magnetization step marks the abrupt transition from a large scale FI/AFI phase separation to a large scale phase separation between AFI, FI and FM phases. Our results suggest that relaxation of elastic strains inherent to the coexistence of these different phases plays a crucial role in the mechanism of these transformations. The occurrence of magnetization steps could result from an intrinsic behavior of the AFI phase at low temperature

    Liquid-based cytology for primary cervical cancer screening: a multi-centre study

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    The aim of this six-centre, split-sample study was to compare ThinPrep fluid-based cytology to the conventional Papanicolaou smear. Six cytopathology laboratories and 35 gynaecologists participated. 5428 patients met the inclusion criteria (age > 18 years old, intact cervix, informed consent). Each cervical sample was used first to prepare a conventional Pap smear, then the sampling device was rinsed into a PreservCyt vial, and a ThinPrep slide was made. Screening of slide pairs was blinded (n = 5428). All non-negative concordant cases (n = 101), all non-concordant cases (n = 206), and a 5% random sample of concordant negative cases (n = 272) underwent review by one independent pathologist then by the panel of 6 investigators. Initial (blinded) screening results for ThinPrep and conventional smears were correlated. Initial diagnoses were correlated with consensus cytological diagnoses. Differences in disease detection were evaluated using McNemar's test. On initial screening, 29% more ASCUS cases and 39% more low-grade squamous intraepithelial lesions (LSIL) and more severe lesions (LSIL+) were detected on the ThinPrep slides than on the conventional smears (P = 0.001), including 50% more LSIL and 18% more high-grade SIL (HSIL). The ASCUS:SIL ratio was lower for the ThinPrep method (115:132 = 0.87:1) than for the conventional smear method (89:94 = 0.95:1). The same trend was observed for the ASCUS/AGUS:LSIL ratio. Independent and consensus review confirmed 145 LSIL+ diagnoses; of these, 18% more had been detected initially on the ThinPrep slides than on the conventional smears (P = 0.041). The ThinPrep Pap Test is more accurate than the conventional Pap test and has the potential to optimize the effectiveness of primary cervical cancer screening. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Tailoring of ferromagnetic Pr0.85Ca0.15MnO3/ferroelectric Ba0.6Sr0.4TiO3 superlattices for multiferroic properties

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    Superlattices composed of ferromagnetic Pr0.85Ca0.15MnO3 and ferroelectric Ba0.6Sr0.4TiO3 layers were fabricated on (100) SrTiO3 substrates by a pulsed-laser deposition method. The capacitance and resistive parts of the samples were analyzed from the complex impedance measurements, performed on the samples using a special experimental set-up. The superlattice with larger ferroelectric thickness shows unique characteristics which are not present in the parent ferromagnetic thin film. The superlattice show both ferromagnetic and ferroelectric transitions which is an evidence for the coexistence of both the properties. The high magnetoresistance (40 % at 80K) shown by the superlattice can be attributed to the coupling between ferromagnetic and ferroelectric layers, i.e, to the magnetoelectric effect.Comment: To be published in App. Phys. Let

    Health and working conditions of pregnant women working inside and outside the home in Mexico City

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    BACKGROUND: To explore differences related to health and working conditions by comparing socio-demographic parameters, reproductive and prenatal care characteristics and working conditions among pregnant women who are employed outside the home (extra-domestic) while still performing a domestic workload versus those who perform exclusively domestic work in the home (intra-domestic). METHODS: A cross-sectional study was carried out at Family Medicine Unit N 31 of the Mexican Institute of Social Security (IMSS) in Mexico City between April and July 2003. Interviews were conducted with 537 pregnant women engaged in either extra-domestic work plus intra-domestic tasks, or those performing strictly intra-domestic work. Information was obtained regarding their demographic status, prenatal care, reproductive, work characteristics, and health during pregnancy. RESULTS: One hundred ninety-six (36.5%) of the interviewed women had paid jobs outside the home in addition to domestic tasks, while three hundred forty-one (63.5 %) engaged in exclusively intra-domestic occupations. Of the women with paid jobs, 78.6% worked as clerks. Among domestic tasks, we found that the greatest workload was associated with washing of clothes, and our micro-ergonomic analysis revealed that women who worked strictly inside the home had a higher domestic workload versus employed women (69.2 vs. 44.9%). When we analyzed the effect of work on health during pregnancy, we observed that women who worked strictly inside the home were at a higher risk for musculoskeletal and genitourinary symptoms than those employed outside the home. CONCLUSION: These findings suggest that the effect of intra-domestic work should not be ignored when considering women's health during pregnancy, and that greater attention should be paid to women's working conditions during intra and extra-domestic work

    MĂ©mento 2 : RĂ©sidences 1999-2000

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    This richly illustrated catalogue documents the work of 35 artists who took part in six residencies (including two events - La Cueillette and La Ruche) that took place in 1999 and 2000 at Centre Est-Nord-Est. The centre’s director, F. Michel, describes the nature and purpose of the residencies as well as that of the catalogue : to reflect each participant’s experience. Includes brief comments by the artist on their work and on their stay. Text in French and English. Biographical notes

    Proteomic Analysis of Grape Berry Cell Cultures Reveals that Developmentally Regulated Ripening Related Processes Can Be Studied Using Cultured Cells

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    The original publication is available at http:/www.plosone.orgBackground: This work describes a proteomics profiling method, optimized and applied to berry cell suspensions to evaluate organ-specific cultures as a platform to study grape berry ripening. Variations in berry ripening within a cluster(s) on a vine and in a vineyard are a major impediment towards complete understanding of the functional processes that control ripening, specifically when a characterized and homogenous sample is required. Berry cell suspensions could overcome some of these problems, but their suitability as a model system for berry development and ripening needs to be established first. Methodology/Principal Findings: In this study we report on the proteomic evaluation of the cytosolic proteins obtained from synchronized cell suspension cultures that were established from callus lines originating from green, véraison and ripe Vitis vinifera berry explants. The proteins were separated using liquid phase IEF in a Microrotofor cell and SDS PAGE. This method proved superior to gel-based 2DE. Principal component analysis confirmed that biological and technical repeats grouped tightly and importantly, showed that the proteomes of berry cultures originating from the different growth/ripening stages were distinct. A total of twenty six common bands were selected after band matching between different growth stages and twenty two of these bands were positively identified. Thirty two % of the identified proteins are currently annotated as hypothetical. The differential expression profile of the identified proteins, when compared with published literature on grape berry ripening, suggested common trends in terms of relative abundance in the different developmental stages between real berries and cell suspensions. Conclusions: The advantages of having suspension cultures that accurately mimic specific developmental stages are profound and could significantly contribute to the study of the intricate regulatory and signaling networks responsible for berry development and ripening. © 2011 Sharathchandra et al.Publishers' Versio

    Identification of stable QTLs for vegetative and reproductive traits in the microvine (Vitis vinifera L.) using the 18 K Infinium chip

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    UMR AGAP - équipe DAAV - Diversité, adaptation et amélioration de la vigne[b]Background[/b] [br/]The increasing temperature associated with climate change impacts grapevine phenology and development with critical effects on grape yield and composition. Plant breeding has the potential to deliver new cultivars with stable yield and quality under warmer climate conditions, but this requires the identification of stable genetic determinants. This study tested the potentialities of the microvine to boost genetics in grapevine. A mapping population of 129 microvines derived from Picovine x Ugni Blanc flb, was genotyped with the Illumina® 18 K SNP (Single Nucleotide Polymorphism) chip. Forty-three vegetative and reproductive traits were phenotyped outdoors over four cropping cycles, and a subset of 22 traits over two cropping cycles in growth rooms with two contrasted temperatures, in order to map stable QTLs (Quantitative Trait Loci). [br/][b]Results[/b] [br/]Ten stable QTLs for berry development and quality or leaf area were identified on the parental maps. A new major QTL explaining up to 44 % of total variance of berry weight was identified on chromosome 7 in Ugni Blanc flb, and co-localized with QTLs for seed number (up to 76 % total variance), major berry acids at green lag phase (up to 35 %), and other yield components (up to 25 %). In addition, a minor QTL for leaf area was found on chromosome 4 of the same parent. In contrast, only minor QTLs for berry acidity and leaf area could be found as moderately stable in Picovine. None of the transporters recently identified as mutated in low acidity apples or Cucurbits were included in the several hundreds of candidate genes underlying the above berry QTLs, which could be reduced to a few dozen candidate genes when a priori pertinent biological functions and organ specific expression were considered. [br/][b]Conclusions[/b] [br/]This study combining the use of microvine and a high throughput genotyping technology was innovative for grapevine genetics. It allowed the identification of 10 stable QTLs, including the first berry acidity QTLs reported so far in a Vitis vinifera intra-specific cross. Robustness of a set of QTLs was assessed with respect to temperature variatio
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