417 research outputs found

    On the Coexistence of Diagonal and off-Diagonal Long-Range Order, a Monte Carlo Study

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    The zero temperature properties of interacting 2 dimensional lattice bosons are investigated. We present Monte Carlo data for soft-core bosons that demonstrate the existence of a phase in which crystalline long-range order and off-diagonal long-range order (superfluidity) coexist. We comment on the difference between hard and soft-core bosons and compare our data to mean-field results that predict a larger coexistence region. Furthermore, we determine the critical exponents for the various phase transitions.Comment: 7 pages and 8 figures appended in postscript, KA-TFP-93-0

    Adaptation of photosystem II to high and low light in wild-type and triazine-resistant Canola plants: analysis by a fluorescence induction algorithm

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    Plants of wild-type and triazine-resistant Canola (Brassica napus L.) were exposed to very high light intensities and after 1 day placed on a laboratory table at low light to recover, to study the kinetics of variable fluorescence after light, and after dark-adaptation. This cycle was repeated several times. The fast OJIP fluorescence rise curve was measured immediately after light exposure and after recovery during 1 day in laboratory room light. A fluorescence induction algorithm has been used for resolution and analysis of these curves. This algorithm includes photochemical and photo-electrochemical quenching release components and a photo-electrical dependent IP-component. The analysis revealed a substantial suppression of the photo-electrochemical component (even complete in the resistant biotype), a partial suppression of the photochemical component and a decrease in the fluorescence parameter Fo after high light. These effects were recovered after 1 day in the indoor light

    Role of Adiposity and Lifestyle in the Relationship Between Family History of Diabetes and 20-Year Incidence of Type 2 Diabetes in U.S. Women

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    OBJECTIVE - To evaluate to what extent the association between family history of diabetes and risk of type 2 diabetes can be explained by excess adiposity and lifestyle risk factors. RESEARCH DESIGN AND METHODS - We analyzed data from 73,227 women who participated in the Nurses' Health Study cohort. A family history of diabetes was defined as having at least one first-degree family member with diabetes. Lifestyle factors, weight, and height were assessed by using validated questionnaires, and BMI was calculated. The relative risk of type 2 diabetes was estimated using Cox proportional hazards analysis. RESULTS - We documented 5,101 cases of type 2 diabetes during 20 years of follow-up. The age-adjusted relative risk of type 2 diabetes in participants with a family history was 2.27 (95% CI 2.14-2.40) compared with the risk in those without a family history of diabetes. Participants with a family history of diabetes had a higher BMI and were more likely to have a parental history of obesity. BMI explained 21.1% (19.4-22.9) of the association between family history of diabetes and risk of type 2 diabetes. Intakes of red meat, alcohol, and sugar-sweetened beverages explained 1.1% (0.8-1.3), 4.8% (4.3-5.3), and 2.8% (2.4-3.2) of this association, respectively. CONCLUSIONS - These results suggest that excess adiposity and, to a lesser extent, specific dietary habits can explain a substantial part of the association between having a family history of diabetes and risk of type 2 diabetes. © 2010 by the American Diabetes Association

    Time sequence of the damage to the acceptor and donor sides of photosystem II by UV-B radiation as evaluated by chlorophyll a fluorescence

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    The effects of ultraviolet-B (UV-B) radiation on photosystem II (PS II) were studied in leaves of Chenopodium album. After the treatment with UV-B the damage was estimated using chlorophyll a fluorescence techniques. Measurements of modulated fluorescence using a pulse amplitude modulated fluorometer revealed that the efficiency of photosystem II decreased both with increasing time of UV-B radiation and with increasing intensity of the UV-B. Fluorescence induction rise curves were analyzed using a mechanistic model of energy trapping. It appears that the damage by UV-B radiation occurs first at the acceptor side of photosystem II, and only later at the donor side

    Impaired Collateral Recruitment and Outward Remodeling in Experimental Diabetes

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    OBJECTIVE—In this study, the effect of chronic hyperglycemia on acute ligation-induced collateral vasodilation, on monocyte chemotaxis, and on structural outward remodeling of collaterals was investigated

    Bronchoalveolar lavage in infants with recurrent lower respiratory symptoms

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    Background: Few data are available about the inflammatory cytokine profile of bronchoalveolar lavage (BAL) from young children with frequent wheeze. The first aim was to investigate the BAL cellular and cytokine profiles in infants with recurrent lower respiratory symptoms in whom bronchoscopy was indicated for clinical symptom evaluation. The second aim was to relate the BAL results with the histological findings of the endobronchial carina biopsies. Methods: Thirty-nine infants (median age 0.9 years) underwent lung function testing by whole-body plethysmography prior to the bronchoscopy. The BAL differential cell counts and cytokine levels were quantified. These findings were compared with the histological findings of the endobronchial carina biopsies. Results: The differential cytology reflected mainly that described for healthy infants with lymphocyte counts at the upper range level. A positive association between BAL CD8+ lymphocytes and neutrophils and endobronchial reticular basement membrane was found. Detectable levels of pro-inflammatory cytokine proteins IL-1 beta, IL-17A, IL-18, IL-23, and IL-33 were found, whereas levels of Th2-type cytokine proteins were low. Frequent wheeze was the only clinical characteristic significantly related to detectable combined pro-inflammatory cytokine profile. Lung function did not correlate with any cytokine. Conclusions: A positive association between BAL CD8+ lymphocytes and neutrophils and endobronchial reticular basement thickness was found. Detectable production of pro-inflammatory cytokines associated positively with frequent wheeze.Peer reviewe
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