2,093 research outputs found
Empiric design evaluation in urban planning
We propose a system to simulate, analyze and visualize occupant behavior in urban environments by combining parametric modeling and agent-based simulation. A procedurally generated 3D city model, with semantic information about the functions and behaviors of buildings, is automatically populated with artificial agents (i.e. pedestrians, cars, and public transport vehicles). In a simulation the built environment and the agents interact with each other. The system identifies empiric correlations between properties such as: functions of buildings and other urban elements, population density, utilization and capacity of the public transport network, and congestion effect on the street network. Practical applications include the assessment of a) bottlenecks, b) public transit efficiency, c) accessibility of amenities, d) quality of service of public transport and the traffic network, as well as e) the stress level and exhaustion of pedestrians. All these aspects ultimately relate to the quality of life within the given urban areas. (C) 2010 Elsevier B.V. All rights reserved.Aschwanden G.D.P.A., Haegler S., Bosché F., Van Gool L., Schmitt G., ''Empiric design evaluation in urban planning'', Automation in construction, vol. 20, no. 3, pp. 299-310, May 2011.status: publishe
Single-File Diffusion of Externally Driven Particles
We study 1-D diffusion of hard-core interacting Brownian particles driven
by the space- and time-dependent external force. We give the exact solution of
the -particle Smoluchowski diffusion equation. In particular, we investigate
the nonequilibrium energetics of two interacting particles under the
time-periodic driving. The hard-core interaction induces entropic repulsion
which differentiates the energetics of the two particles. We present exact
time-asymptotic results which describe the mean energy, the accepted work and
heat, and the entropy production of interacting particles and we contrast these
quantities against the corresponding ones for the non-interacting particles
Composite Texture Synthesis
Many textures require complex models to describe their intricate structures. Their modeling can be simplified if they are considered composites of simpler subtextures. After an initial, unsupervised segmentation of the composite texture into the subtextures, it can be described at two levels. One is a label map texture, which captures the layout of the different subtextures. The other consists of the different subtextures. This scheme has to be refined to also include mutual influences between textures, mainly found near their boundaries. The proposed composite texture model also includes these. The paper describes an improved implementation of this idea. Whereas in a previous implementation subtextures and their interactions were synthesized sequentially, this paper proposes a parallel implementation, which yields results of higher qualit
Targeting EZH2 Reprograms Intratumoral Regulatory T Cells to Enhance Cancer Immunity.
Regulatory T cells (Tregs) are critical for maintaining immune homeostasis, but their presence in tumor tissues impairs anti-tumor immunity and portends poor prognoses in cancer patients. Here, we reveal a mechanism to selectively target and reprogram the function of tumor-infiltrating Tregs (TI-Tregs) by exploiting their dependency on the histone H3K27 methyltransferase enhancer of zeste homolog 2 (EZH2) in tumors. Disruption of EZH2 activity in Tregs, either pharmacologically or genetically, drove the acquisition of pro-inflammatory functions in TI-Tregs, remodeling the tumor microenvironment and enhancing the recruitment and function of CD8+ and CD4+ effector T cells that eliminate tumors. Moreover, abolishing EZH2 function in Tregs was mechanistically distinct from, more potent than, and less toxic than a generalized Treg depletion approach. This study reveals a strategy to target Tregs in cancer that mitigates autoimmunity by reprogramming their function in tumors to enhance anti-cancer immunity
Neuropsychiatric symptoms of cholinergic deficiency occur with degradation of the projections from the nucleus basalis of Meynert
This study aims to evaluate the relation between a cluster of neuropsychiatric symptoms related to cholinergic deficiency and degradation of the cortical cholinergic projections which project from the nucleus basalis of Meynert to the cerebral cortex. An atlas of the pathway from the nucleus basalis to the cortex (NbM cortical pathway) was constructed using diffusion tensor imaging and tractography in 87 memory clinic patients. Structural degradation was considered to be represented by lower fractional anisotropy (FA) and higher mean diffusivity (MD). Neuropsychiatric symptoms were assessed using the Neuropsychiatric Inventory. A predefined cluster including agitation, anxiety, apathy, delusions, hallucinations, and irritability was labeled as the cholinergic deficiency syndrome (CDS). In regression analyses, lower FA and higher MD in the NbM cortical pathway were associated with CDS symptoms but not with other neuropsychiatric symptoms. These associations were independent of cerebral atrophy and overall FA or MD. There was no association between interruption of the NbM cortical pathway by white matter hyperintensities and CDS symptoms. Cox regression suggested a trend for higher mortality with lower FA in the NbM cortical pathway may exist. These findings provide anatomical support for the hypothesis that degradation of the cholinergic projections from the nucleus basalis of Meynert may lead to a distinct clinical syndrome. Future studies could use our results to test the utility of assessing NbM projection integrity to identify patients who may benefit from cholinergic treatment or with a worse prognosi
Escherichia coli RuvBL268S: A mutant RuvB protein that exhibits wild-type activities in vitro but confers a UV-sensitive ruv phenotype in vivo
The RuvABC proteins of Escherichia coli process recombination intermediates during genetic recombination and DNA repair. RuvA and RuvB promote branch migration of Holliday junctions, a process that extends heteroduplex DNA. Together with RuvC, they form a RuvABC complex capable of Holliday junction resolution. Branch migration by RuvAB is mediated by RuvB, a hexameric ring protein that acts as an ATP-driven molecular pump. To gain insight into the mechanism of branch migration, random mutations were introduced into the ruvB gene by PCR and a collection of mutant alleles were obtained. Mutation of leucine 268 to serine resulted in a severe UV-sensitive phenotype, characteristic of a ruv defect. Here, we report a biochemical analysis of the mutant protein RuvBL268S. Unexpectedly, the purified protein is fully active in vitro with regard to its ATPase, DNA binding and DNA unwinding activities. It also promotes efficient branch migration in combination with RuvA, and forms functional RuvABC-Holliday junction resolvase complexes. These results indicate that RuvB may perform some additional, and as yet undefined, function that is necessary for cell survival after UV-irradiatio
De relatie tussen waterkwaliteit en welzijn bij Afrikaanse meerval en tong op Nederlandse viskwekerijen
Het doel van deze literatuurstudie is het beschrijven van de mogelijke knelpunten in de relatie tussen het welzijn van vissen en de waterkwaliteit in recirculatiesystemen (RAS), gespecificeerd op de Afrikaanse meerval (Clarias gariepinus) en tong (Solea solea). Hiernaast is bij een tongkwekerij en bij twee meervalkwekerijen een studie uitgevoerd naar de waterkwaliteit. De resultaten tonen aan dat de temperatuur, pH en zuurstofconcentratie van het water constant zijn. Het TAN-niveau (Total Ammonia Nitrogen) laat een variabel beeld zien bij de meervalkwekerijen, bij de tongkwekerij is het TAN-niveau constant laag
The importance of both setting and intensity of physical activity in relation to non-clinical anxiety and depression
Physical activity is associated with good physical and mental health. Current recommendations suggest that people should achieve 30 minutes of moderate-intensity activity most days of the week to gain health benefits. This activity may be accumulated in leisure time, in active commuting, at work or in the home. Here we look at the cross-sectional relationship between physical activity and mental health as measured by the HADS anxiety and depression scores in a sample of 1,742 participants from a Scottish general population survey. The participants were men and women in three age cohorts aged around 24, 44 and 64 years who, in 1995, were interviewed face to face and also self-completed the HADS depression and anxiety scale. Respondents reported their levels of physical activity at work, in the home and in leisure time; the intensities of activity were also determined. Physical activity was related to depression scores but not to anxiety scores. There was no relationship between work physical activity and depression score. Among women, depression score increased with each additional episode of vigorous home activity. In both sexes, depression score decreased with each additional episode of vigorous leisure activity, but among men the decrease in depression score with moderate leisure activity was reversed if a lot of moderate activity was undertaken. We have found a variable relationship between depression scores and various settings for physical activity. Researchers, policymakers and practitioners who are interested in the relationship between physical activity and mental health should take into account the setting for activity as well as frequency, duration and intensity of activity
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