2,764 research outputs found

    Effekte des Ringschneidereinsatzes zur pfluglosen Boden-bearbeitung auf physikalische Eigenschaften sandiger Böden

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    Organic farming on sandy soils in Brandenburg is especially vulnerable to climate change impacts like drought and heavy rainfall. Reduced tillage is considered as one possible adaptation measure. For technical implementation the ring cutter allowing shallow non-inversion tillage with overall root-cutting is under investigation. Its effects on soil bulk density, soil organic matter content, root mass and soil water retention as well as the yield of winter rye were quantified. Results from the spring showed a significant accumulation of organic matter in the tilled top layer and both a significant increase of bulk density and a significant decrease of root mass in the non-tilled lower topsoil. Water retention in the non-tilled layer was reduced. The yield of winter rye was 27 % lower. Due to a compaction the non-tilled layer of the soil was less penetrable by roots. The showed results of only one date do not allow reasoning to a whole tillage system. In the present case it is recommended to loosen the compacted non-tilled layer with additional non-inversion tillage

    Observation of many-body localization of interacting fermions in a quasi-random optical lattice

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    We experimentally observe many-body localization of interacting fermions in a one-dimensional quasi-random optical lattice. We identify the many-body localization transition through the relaxation dynamics of an initially-prepared charge density wave. For sufficiently weak disorder the time evolution appears ergodic and thermalizing, erasing all remnants of the initial order. In contrast, above a critical disorder strength a significant portion of the initial ordering persists, thereby serving as an effective order parameter for localization. The stationary density wave order and the critical disorder value show a distinctive dependence on the interaction strength, in agreement with numerical simulations. We connect this dependence to the ubiquitous logarithmic growth of entanglement entropy characterizing the generic many-body localized phase.Comment: 6 pages, 6 figures + supplementary informatio

    Relationship of Dropout and Psychopathology in a High School Sample in Mexico

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    School dropout has significant consequences for both individuals and societies. Only 21% of adults in Mexico achieve the equivalent of a high school education. We examined the relationship between school dropout and self-reported psychiatric symptoms in a middle school in a suburb of Mexico City. We used binomial logistic regression to examine the odds ratio (OR) of school dropout associated with students’ self-reported psychopathology. Two-hundred thirty-seven students participated in the study. Psychosis [OR = 8.0 (95% confidence interval, CI: 1.7–37.2)], depression [OR = 4.7 (95% CI: 2.2–9.7)], tic disorders [OR = 3.7 (95% CI: 1.4–9.5)], ADHD [OR = 3.2 (95% CI: 1.5–6.4)], and social phobia [OR = 2.6 (95% CI: 1.2–5.8)] were associated with increased risk of school dropout after controlling for age and gender as covariates. Our study suggested that students’ self-reported psychopathology is associated with increased school dropout in Mexico. ADHD and depression may be particularly useful childhood psychiatric disorders to target with public health interventions because they explain the greatest amount of the variance in school dropout of child psychiatric disorders

    Measuring the temporal coherence of an atom laser beam

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    We report on the measurement of the temporal coherence of an atom laser beam extracted from a 87^{87}Rb Bose-Einstein condensate. Reflecting the beam from a potential barrier creates a standing matter wave structure. From the contrast of this interference pattern, observed by magnetic resonance imaging, we have deduced an energy width of the atom laser beam which is Fourier limited by the duration of output coupling. This gives an upper limit for temporal phase fluctuations in the Bose-Einstein condensate.Comment: 4 pages, 3 figure

    Analysis of clogging in constructed wetlands using magnetic resonance

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    In this work we demonstrate the potential of permanent magnet based magnetic resonance sensors to monitor and assess the extent of pore clogging in water filtration systems. The performance of the sensor was tested on artificially clogged gravel substrates and on gravel bed samples from constructed wetlands used to treat wastewater. Data indicate that the spin lattice relaxation time is linearly related to the hydraulic conductivity in such systems. In addition, within biologically active filters we demonstrate the ability to determine the relative ratio of biomass to abiotic solids, a measurement which is not possible using alternative techniques

    Optics with an Atom Laser Beam

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    We report on the atom optical manipulation of an atom laser beam. Reflection, focusing and its storage in a resonator are demonstrated. Precise and versatile mechanical control over an atom laser beam propagating in an inhomogeneous magnetic field is achieved by optically inducing spin-flips between atomic ground states with different magnetic moment. The magnetic force acting on the atoms can thereby be effectively switched on and off. The surface of the atom optical element is determined by the resonance condition for the spin-flip in the inhomogeneous magnetic field. A mirror reflectivity of more than 98% is measured

    Internationale Beziehungen und Soziologie : das ‚Scharnier’ der Differenzierung

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    Meta-analysis of the heterogeneous symptoms of obsessive-compulsive disorder (OCD) has found a four-factor structure of symptom dimensions consisting of cleaning, forbidden thoughts, symmetry, and hoarding. Research into age of onset of symptom dimensions has yielded inconsistent results, and it is unknown whether symptoms along these dimensions differ in their clinical course. We assessed age of onset and clinical course of different OCD symptom dimensions in a large cohort of adult patients. Nine-hundred fifty-five subjects were assessed using the Dimensional Yale-Brown Obsessive-Compulsive Scale. For age of onset analysis, we tested across three methods of classification: (1) primary (more severe) symptom dimension (2) clinically significant symptoms within a dimension or (3) any symptoms within a dimension. Age of onset was defined as the earliest age of onset reported for any individual item within a symptom dimension. For analysis of different types of clinical course, we used chi-square tests to assess for differences between primary symptom dimensions. OCD symptoms in the symmetry dimension had an earlier age of onset than other OCD symptom dimensions. These findings remained significant across all three methods of classification and controlling for gender and comorbid tics. No significant differences were found between the other dimensions. Subjects with primary OCD symptoms in the forbidden thoughts dimension were more likely to report a waxing-and-waning course, whereas symmetry symptoms were less likely to be associated with a waxing-and-waning course. © 2013

    Severe Illness Anxiety Treated by Integrating Inpatient Psychotherapy With Medical Care and Minimizing Reassurance

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    Illness anxiety disorder (IAD, formerly hypochondriasis) is characterized by preoccupation with fear of serious illness despite medical reassurance. IAD is common, debilitating, challenging to treat, and results in high healthcare utilization. Outpatient management of IAD is challenging because patients can compulsively seek reassurance from numerous providers, which interferes with learning more productive coping skills. We present the case of a woman with severe IAD who presented to the emergency room with increasing frequency over several months, despite regular outpatient medical visits and escalating psychiatric care. We made the unusual decision to hospitalize her for IAD for 1 month, in the absence of typical hospitalization criteria. This hospitalization allowed us to consolidate all medical and psychiatric care into a single provider team and train all staff and family to communicate with her in a consistent manner. We successfully treated her by integrating a general cognitive-behavioral therapy (CBT) protocol into medical care and decision-making. In response to her numerous health concerns, we minimized medical work-up, reassurance, and reactive medication changes, and instead used the concerns as opportunities to reinforce the psychotherapy. This approach allowed us to simplify her medication regimen and manage her co-morbid hypertension and vitamin deficiencies. Though inpatient hospitalization is likely infeasible in most cases of IAD, outpatient providers may create similar treatment plans based on the example of our case report, without needing highly specialized expertise. Such a plan would require a straightforward understanding of IAD psychology, which we review here, combined with readily accessible tools including a universal CBT protocol, online CBT courses, and clinical symptom scales. We discuss our approach for responding to health concerns, maintaining therapeutic alliance, integrating CBT principles into patient interactions, and managing medications. Since patients with IAD share health concerns with all providers, staff, and family, we also include our own IAD communication guide, appropriate for a general audience, that demonstrates how to respond in these conversations

    Overnight Immune Regulation and Subjective Measures of Sleep: A Three Night Observational Study in Adolescent Track and Field Athletes

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    To ensure health maintenance of young athletes, immunological stress due to physical exercise has to be balanced for performance development and health maintenance. Sleep is an important influencing factor for immune regulation because of its regenerating effect. In an attempt to assess overnight immune regulation, this observational study aimed to examine associations between changes in capillary immunological blood markers and measures of sleep in adolescent athletes. Over a period of three nights, 12 male ( n = 6) and female ( n = 6) adolescent track and field athletes aged 16.4 ± 1.1 years were monitored for their sleep behavior (e.g., sleep duration, sleep depth) and immune regulation by using subjective (e.g., sleep) and objective (capillary blood markers) measurement tools. Over the 4 day (three nights), athletes followed their daily routines (school, homework, free time activities, and training). Training was performed for different disciplines (sprint, hurdles, and long-jump) following their daily training routines. Training included dynamic core stability training, coordination training, speed training, resistance training, and endurance training. Capillary blood samples were taken 30–45 min after the last training session (10:00–12:00 a.m. or 5:00–6:00 p.m.) and every morning between 7:00 and 10:00 a.m. Changes in capillary blood markers from post-training to the next morning and morning-to-morning fluctuations in capillary blood markers were analyzed over a three-night period using a generalized estimating equations (GEE) statistical approach. Associations of overnight changes with measures of sleep were analyzed using GEE. We found significant decreases in white blood cell count (WBC), granulocytes (GRAN), granulocytes% (GRAN%), monocytes (MID), and granulocyte-lymphocyte-ratio. In contrast, lymphocytes% (LYM%) increased significantly and systemic inflammation index showed no difference from post-training to the next morning. Furthermore, there was a significant decrease in WBC and GRAN between morning 1 and morning 3. At morning 4, values returned to baseline (morning 1), irrespective if athletes performed a training session or rested on day 3. Furthermore, sleep duration was significantly and negatively associated with changes in WBC (β z = −0.491) and lymphocytes (β z = −0.451). Our results indicate that overnight sleep duration is an important parameter of immunological overnight regulation for adolescent athletes
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