1,086 research outputs found

    Spin-resolved electron-impact ionization of lithium

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    Electron-impact ionization of lithium is studied using the convergent close-coupling (CCC) method at 25.4 and 54.4 eV. Particular attention is paid to the spin-dependence of the ionization cross sections. Convergence is found to be more rapid for the spin asymmetries, which are in good agreement with experiment, than for the underlying cross sections. Comparison with the recent measured and DS3C-calculated data of Streun et al (1999) is most intriguing. Excellent agreement is found with the measured and calculated spin asymmetries, yet the discrepancy between the CCC and DS3C cross sections is very large

    Physical Mapping of Micronutritional Genes in Wheat-rye Translocations

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    In rye (Secale cereale L.), there are loci on chromosome arm 5RL which give rise to increased copper (Cu)- and iron (Fe)-efficiency, respectively. Four different wheat-rye translocations each harboring a terminal segment of different size of the rye chromosome arm 5RL were identified by test crosses and Giemsa-banding: \u27T29\u27 (5AS.5RL), \u27T63\u27 (5BS.5BL-5RL), \u27Vhn\u27 (4BS.4BL-5RL) and \u27Cor\u27 (4BS.4BL-5RL). The translocation break points were detected by chromosome painting technique GISH and the sizes of the rye chromosome segments involved were determined by computer image analysis. The Cu-efficiency gene Ce was physically mapped to the terminal region of 5RL, and the genes for mugineic acid and for hydroxymugineic acid synthetases involved in the strategy II of Fe-efficiency control to two intercalary regions of 5RL. In all wheat-rye translocation lines the Ce gene is linked to the dominant hairy neck character (HaI) from rye. This morphological trait and the RFLP probe \u27WG 199\u27 as well can serve as proper markers for a marker-based large-scale selection in wheat breeding

    Calculation of the free-free transitions in the electron-hydrogen scattering S-wave model

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    The S-wave model of electron-hydrogen scattering is evaluated using the convergent close-coupling method with an emphasis on scattering from excited states including an initial state from the target continuum. Convergence is found for discrete excitations and the elastic free-free transition. The latter is particularly interesting given the corresponding potential matrix elements are divergent

    Patient characteristics differently affect early cup and stem loosening in THA: a case-control study on 7,535 patients

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    We postulated that certain patient characteristics have different effects on early THA component loosening. With two matched case-control studies we assessed 3,028 cups and 5,224 stems. Loosening was defined using signs of mechanical component failure on routine follow-up radiographs or revision for aseptic loosening. Women and men had similar cup-loosening odds, but women had lower odds for stem loosening (p < 0.0001). Odds for cup loosening decreased by 2.1% per additional year of age (p = 0.0004), those for stem loosening by 2.4% (p < 0.0001). Each additional kilogram of weight decreased cup loosening odds by 1.3% (p = 0.0051). Each additional unit of BMI increased stem loosening odds (p = 0.0109). Charnley classes B and C were protective factors against loosening of both components. There were no risk differences for the various main diagnoses. Certain patient characteristics differently affected early cup and stem loosening, although some characteristics had the same protective or harmful effect on component surviva

    Verwendungsraten von Prothesen der unteren Extremität in Deutschland und der Schweiz: Ein Vergleich der Jahre 2005-2008

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    Zusammenfassung: Hintergrund: In den USA hat die Verwendung der totalen Hüftprothese innerhalb der letzten Dekade stark zugenommen. Es ist jedoch nicht bekannt, ob sich dieser Trend auf andere Länder übertragen lässt. Ziel dieser Untersuchung war daher der detaillierte Vergleich der Verwendungsraten von Hüft-, Knie- und OSG-Prothesen in der BRD und der Schweiz im Zeitraum 2005-2008 und ein Sekundärvergleich mit den USA. Patienten und Methoden: Aus Daten der beiden statistischen Bundesämter wurden die Einwohnerzahl, Geschlechts- und Altersverteilung sowie die Anzahl von Primär- und Revisionseingriffen ermittelt. Aus diesen Kennzahlen konnte die Anzahl von Primär-, Revisions- und Gesamteingriffen, der Revisionslast, von Primär- und Revisionsraten pro 100.000 Einwohner und Jahr sowie geschlechts- und altersspezifische Primär- und Revisionsraten berechnet werden. Ein im Vergleich dazu reduzierter Datensatz aus den USA stammt direkt vom Autor der entsprechenden Auswertungen. Ergebnisse: In Deutschland, der Schweiz und den USA stieg die Anzahl der Voll- und Teilhüftprothesenimplantationen pro 100.000 Personen von 235,8, 238,2 und 116,8 im Jahr 2005 auf 254,7, 262,7 und 127,3 an. Für Voll- und Teilknieprothesen lagen die Raten bei 156,3, 140,1 und 178,2 Implantationen in 2005 und 188,3, 176,8 und 213,6 in 2008. Die Revisionslast für Hüftprothesen lag in der BRD in 2005 mit 13,6% um 3,6% höher als in der Schweiz und betrug 11,2% in den USA. In 2008 lag sie mit 15,1% um 4,6% höher als in der Schweiz und betrug wiederum 11,2% in den USA. Für Knieprothesen lag die Last in der BRD in 2005 bei 11,1% und damit 3,5% höher als in der Schweiz; in den USA betrug sie 7,4%. In 2008 lag sie bei 12,8% und somit 4,2% höher als in der Schweiz und betrug 8,9% in den USA. In allen 3 Ländern lag die Revisionslast für Knieprothesen stets unter derjenigen für Hüftprothesen. Schlussfolgerung: In allen 3 Ländern stiegen die Primärraten für Hüft- und Knieprothesen an, diejenigen für Knieprothesen stärker. Die Revisionslasten lagen in 2008 für beide Prothesentypen in der BRD am höchsten. In der Schweiz gab es eine vorübergehende Senkung der Revisionslasten und erst ab 2007 wieder einen Anstieg. Die Verwendungsrate von Hüftprothesen pro 100.000 Einwohner lag in den USA stark unter den Raten der BRD und der Schweiz, für Knieprothesen lag sie leicht darübe

    Evaluation of laboratory and on-farm tests to estimate colostrum quality for dairy cows

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    The objectives of this study were to evaluate different analytical methods to determine colostrum quality in dairy cattle, including one laboratory-based method (ELISA) and 4 on-farm tests. We hypothesized that the colostral IgG concentration using different analytical methods, such as ELISA (mg/mL), digital Brix refractometer (% Brix), colostrometer (specific gravity and mg/mL), an outflow funnel (seconds), and a lateral flow assay (mg/mL), were highly correlated with the reference method, radial immunodiffusion (RID; mg/mL) and would generate comparable results. Colostrum samples were collected from 209 Holstein Friesian cows on 2 commercial dairy farms in Germany. Colostrum weight and colostrum temperature were measured. Test characteristics, such as optimum thresholds, sensitivity, specificity, and area under the curve (AUC) were determined using a receiver operating characteristic curve analyses for each test. Out of 209 colostrum samples assessed by RID, 186 (89%) samples had high quality (≥50 mg IgG/mL), while 23 colostrum samples (11%) showed poor quality with IgG concentrations less than 50 mg/mL. The mean IgG concentration (±SD) was 101.3 ± 45.9 mg/mL and the range was 6.0 to 244.3 mg/mL. The Pearson correlation coefficient (r) between RID and ELISA was r = 0.78. In comparison to RID, Pearson correlation coefficients for the on-farm tests were: r = 0.79 (digital Brix refractometry), r = 0.58 (colostrometer: specific gravity), r = 0.61 (colostrometer: temperature corrected), r = 0.26 (outflow funnel) and r = 0.43 (lateral flow assay), respectively. The optimal threshold to identify high-quality colostrum using ELISA was 50.8 mg/mL with sensitivity 91.3%, specificity 92.3%, and AUC of 0.94. For the on-farm tests sensitivity ranged from 95.7% (Brix refractometry) to 60.9% (lateral flow assay). Specificity ranged from 88.6% (lateral flow assay) to 75.9% (colostrometer: temperature corrected). The AUC ranged from 0.93 (Brix refractometry) to 0.73 (outflow funnel). Based on the AUC, ELISA (0.94) and Brix refractometry (0.93) can be considered highly accurate. In conclusion, the ELISA is accurate to assess colostrum quality. Regarding the on-farm tests only the digital Brix refractometer and the colostrometer were adequate to determine colostrum quality

    Electron-impact ionization of atomic hydrogen at 2 eV above threshold

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    The convergent close-coupling method is applied to the calculation of fully differential cross sections for ionization of atomic hydrogen by 15.6 eV electrons. We find that even at this low energy the method is able to yield predictive results with small uncertainty. As a consequence we suspect that the experimental normalization at this energy is approximately a factor of two too high.Comment: 10 page

    Competing Ground States of the New Class of Halogen-Bridged Metal Complexes

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    Based on a symmetry argument, we study the ground-state properties of halogen-bridged binuclear metal chain complexes. We systematically derive commensurate density-wave solutions from a relevant two-band Peierls-Hubbard model and numerically draw the the ground-state phase diagram as a function of electron-electron correlations, electron-phonon interactions, and doping concentration within the Hartree-Fock approximation. The competition between two types of charge-density-wave states, which has recently been reported experimentally, is indeed demonstrated.Comment: 4 pages, 5 figures embedded, to appear in J. Phys. Soc. Jp

    Maternal stress, child behavior and the promotive role of older siblings

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    Abstract Background: In the first years of their lives, children develop the cognitive, social and emotional skills that will provide the foundations for their lifelong health and achievements. To increase their life prospects and reduce the long-term effects of early aversive conditions, it is therefore crucial to understand the risk factors that negatively affect child development and the factors that are instead beneficial. In this study, we tested (i) the effects of different social and environmental stressors on maternal stress levels, (ii) the dynamic relationship between maternal stress and child behavior problems during development, and (iii) the potential promotive (i.e. main) or protective (i.e. buffering) effect of siblings on child behavior problems during development.Methods: We used longitudinal data from 373 mother–child pairs (188 daughters, 185 sons) from pregnancy until 10 years of age. We assessed maternal stress and child behavior problems (internalizing and externalizing) with vali-dated questionnaires, and then used linear mixed models, generalized linear mixed models and longitudinal cross-lagged models to analyze the data.Results: Our results showed that higher maternal stress levels were predicted by socio-environmental stressors (i.e. the lack of sufficient social areas in the neighborhood). Moreover, prenatal maternal stress reliably predicted the occurrence of behavior problems during childhood. Finally, the presence of older siblings had a promotive function, by reducing the likelihood that children developed externalizing problems.Conclusions: Overall, our results confirm the negative effects that maternal stress during pregnancy may have on the offspring, and suggest an important main effect of older siblings in promoting a positive child development

    Breakdown of a conservation law in incommensurate systems

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    We show that invariance properties of the Lagrangian of an incommensurate system, as described by the Frenkel Kontorova model, imply the existence of a generalized angular momentum which is an integral of motion if the system remains floating. The behavior of this quantity can therefore monitor the character of the system as floating (when it is conserved) or locked (when it is not). We find that, during the dynamics, the non-linear couplings of our model cause parametric phonon excitations which lead to the appearance of Umklapp terms and to a sudden deviation of the generalized momentum from a constant value, signalling a dynamical transition from a floating to a pinned state. We point out that this transition is related but does not coincide with the onset of sliding friction which can take place when the system is still floating.Comment: 7 pages, 6 figures, typed with RevTex, submitted to Phys. Rev. E Replaced 27-03-2001: changes to text, minor revision of figure
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