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Rimac A.,Max Planck Institute for Meteorology | Rimac A.,International Max Planck Research School | Von Storch J.-S.,Max Planck Institute for Meteorology | Eden C.,University of Hamburg | Haak H.,Max Planck Institute for Meteorology
Geophysical Research Letters | Year: 2013

The wind power input to near-inertial (NI) motions is studied using a global eddy-permitting ocean general circulation model. The model is forced by high- (1-hourly, at 0.35° resolution) and low-resolution (6-hourly, at 1.875° resolution) wind data. A change from low- to high-resolution forcing results in an increase in NI kinetic energy by a factor three and raises the wind-generated power input to NI motions from 0.3 TW to 1.1 TW. Time and space filtering of the wind fields yield less kinetic energy, with a larger drop from time filtering. This strong sensitivity to wind forcing points to a possible underestimation of the wind-generated energy available for deep ocean mixing in previous studies based on low-resolution winds. © 2013. American Geophysical Union. All Rights Reserved.

Dallmeyer A.,Max Planck Institute for Meteorology | Claussen M.,Max Planck Institute for Meteorology | Claussen M.,University of Hamburg | Otto J.,International Max Planck Research School
Climate of the Past | Year: 2010

The impact of vegetation-atmosphere and ocean-atmosphere interactions on the mid- to late Holocene climate change as well as their synergy is studied for different parts of the Asian monsoon region, giving consideration to the large climatic and topographical heterogeneity in that area. We concentrate on temperature and precipitation changes as the main parameters describing monsoonal influenced climates. For our purpose, we analyse a set of coupled numerical experiments, performed with the comprehensive Earth system model ECHAM5/JSBACH-MPIOM under present-day and mid-Holocene (6 k) orbital configurations (Otto et al., 2009b). The temperature change caused by the insolation forcing reveals an enhanced seasonal cycle, with a pronounced warming in summer (0.58 K) and autumn (1.29 K) and a cooling in the other seasons (spring: -1.32 K; winter: -0.97 K). Most of this change can be attributed to the direct response of the atmosphere, but the ocean, whose reaction has a lagged seasonal cycle (warming in autumn and winter, cooling in the other seasons), strongly modifies the signal. The simulated contribution of dynamic vegetation is small and most effective in winter, where it slightly warms the near-surface atmosphere (approx. 0.03 K). The temperature difference attributed to the synergy is on average positive, but also small. Concerning the precipitation, the most remarkable change is the postponement and enhancement of the Asian monsoon (0.46 mm/day in summer, 0.53 mm/day in autumn), mainly related to the direct atmospheric response. On regional average, the interactive ocean (ca. 0.18 mm/day) amplifies the direct effect, but tends to weaken the East Asian summer monsoon and strongly increases the Indian summer monsoon rainfall rate (0.68 mm/day). The influence of dynamic vegetation on precipitation is comparatively small (<0.04 mm/day). The synergy effect has no influence, on average. © Author(s) 2010.

Held M.,Free University of Berlin | Held M.,International Max Planck Research School | Metzner P.,University of Lugano | Metzner P.,Deutsche Forschungsgemeinschaft Research Center | And 4 more authors.
Biophysical Journal | Year: 2011

Protein-ligand interactions are essential for nearly all biological processes, and yet the biophysical mechanism that enables potential binding partners to associate before specific binding occurs remains poorly understood. Fundamental questions include which factors influence the formation of protein-ligand encounter complexes, and whether designated association pathways exist. To address these questions, we developed a computational approach to systematically analyze the complete ensemble of association pathways. Here, we use this approach to study the binding of a phosphate ion to the Escherichia coli phosphate-binding protein. Various mutants of the protein are considered, and their effects on binding freeenergy profiles, association rates, and association pathway distributions are quantified. The results reveal the existence of two anion attractors, i.e., regions that initially attract negatively charged particles and allow them to be efficiently screened for phosphate, which is subsequently specifically bound. Point mutations that affect the charge on these attractors modulate their attraction strength and speed up association to a factor of 10 of the diffusion limit, and thus change the association pathways of the phosphate ligand. It is demonstrated that a phosphate that prebinds to such an attractor neutralizes its attraction effect to the environment, making the simultaneous association of a second phosphate ion unlikely. This study suggests ways in which structural properties can be used to tune molecular association kinetics so as to optimize the efficiency of binding, and highlights the importance of kinetic properties. © 2011 by the Biophysical Society.

Gazi M.A.,International Center for Diarrheal Disease Research | Islam M.R.,International Max Planck Research School | Islam M.R.,University of Bordeaux Segalen | Kibria M.G.,International Center for Diarrheal Disease Research | Mahmud Z.,University of Dhaka
European Journal of Clinical Microbiology and Infectious Diseases | Year: 2015

The global control of tuberculosis remains a great challenge from the standpoint of diagnosis, detection of drug resistance, and treatment, because treatment can only be initiated when infection is detected, and is guided by the results of antimicrobial susceptibility testing. To a large extent, non-molecular, immunological, and other biochemical methods are refinements or modifications of conventional methods, with the primary goal of providing more rapid test results. In contrast, molecular methods use novel technologies to detect the presence of Mycobacterium tuberculosis complex and genes conferring drug resistance. As a group, molecular technologies offer the greatest potential for laboratories in resource-rich countries because they have the highest sensitivity and specificity. In resource-poor settings, continued development of affordable, sensitive, and specific diagnostic tools will be required, where the incidence of disease is highest. © 2015, Springer-Verlag Berlin Heidelberg.

Koring M.,Free University of Berlin | Koring M.,International Max Planck Research School | Richert J.,Free University of Berlin | Parschau L.,Free University of Berlin | And 3 more authors.
Psychology, Health and Medicine | Year: 2012

Many individuals are motivated to improve their physical activity levels, but often fail to act upon their intention. Interventions fostering volitional strategies, suchas action planning, coping planning, and self-efficacy beliefs, can help to translate intentions into behavior. This study examines the effectiveness and themechanisms of a combined planning and self-efficacy intervention to promote physical activity among motivated individuals. Participants (N = 883) were randomly assigned to the intervention or to a waiting-list control condition. Multivariate analysis of variance revealed that the intervention resulted in significantly more physical activity, higher levels of action planning, coping planning, and volitional self-efficacy beliefs (p < 0.01). In addition, multiple mediation analysis showed that action planning, coping planning, and volitional self-efficacy mediate between the intervention and physical activity. The study shows that the intervention successfully fostered physical activity and unfolds the underlying self-regulatory mechanisms of the intervention's effectiveness. © 2012 Taylor and Francis.

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