372 research outputs found

    All-glass shell scale models made with an adjustable mould

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    Ever since Lucio Blandini developed a doubly curved synclastic shell with adhesively bonded glass components, the concept of building a self-supporting glass-only shell has almost become within reach. In the current contribution a small-scaled experimental concept is presented of a self-supporting anticlastic all-glass shell scale model, created by means of an adaptable mould. First, different manufacturing parameters of relatively small shells are investigated, such as mould type, glass supporting system and dimensions, oven temperature and shell curvature. Next, an adjustable mould for the bending of glass is developed, built and tested. With this mould it is possible to make glass panels synclastic and anticlastic in a great variety of forms. With this new moulding technique we were able to create different prototypes. They are forming the basis an intended larger shell, composed of smaller segments. The objective is to join the latter by using fusing techniques, which result is completely transparent monolithic all-glass shells. Therefore, additional experiments have been performed to explore different variants of glass fusion techniques to be applied for double curved glass shells

    Sheaf theory for stacks in manifolds and twisted cohomology for S^1-gerbes

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    This is the first of a series of papers on sheaf theory on smooth and topological stacks and its applications. The main result of the present paper is the characterization of the twisted (by a closed integral three-form) de Rham complex on a manifold. As an object in the derived category it will be related with the push-forward of the constant sheaf from a S^1-gerbe with Dixmier-Douady class represented by the three-form. In order to formulate and prove this result we develop in detail the foundations of sheaf theory for smooth stacks.Comment: 39 pages, v2 typos corrected and references added. v3 confusion in 2.2.5 cleaned u

    Activity of metazoa governs biofilm structure formation and enhances permeate flux during Gravity-Driven Membrane (GDM) filtration

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    The impact of different feed waters in terms of eukaryotic populations and organic carbon content on the biofilm structure formation and permeate flux during Gravity-Driven Membrane (GDM) filtration was investigated in this study. GDM filtration was performed at ultra-low pressure (65 mbar) in dead-end mode without control of the biofilm formation. Different feed waters were tested (River water, pre-treated river water, lake water, and tap water) and varied with regard to their organic substrate content and their predator community. River water was manipulated either by chemically inhibiting all eukaryotes or by filtering out macrozoobenthos (metazoan organisms). The structure of the biofilm was characterized at the meso- and micro-scale using Optical Coherence Tomography (OCT) and Confocal Laser Scanning Microscopy (CLSM), respectively. Based on Total Organic Carbon (TOC) measurements, the river waters provided the highest potential for bacterial growth whereas tap water had the lowest. An increasing content in soluble and particulate organic substrate resulted in increasing biofilm accumulation on membrane surface. However, enhanced biofilm accumulation did not result in lower flux values and permeate flux was mainly influenced by the structure of the biofilm. Metazoan organisms (in particular nematodes and oligochaetes) built-up protective habitats, which resulted in the formation of open and spatially heterogeneous biofilms composed of biomass patches. In the absence of predation by metazoan organisms, a flat and compact biofilm developed. It is concluded that the activity of metazoan organisms in natural river water and its impact on biofilm structure balances the detrimental effect of a high biofilm accumulation, thus allowing for a broader application of GDM filtration. Finally, our results suggest that for surface waters with high particulate organic carbon (POC) content, the use of worms is suitable to enhance POC removal before ultrafiltration units

    Model structures on the category of small double categories

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    In this paper we obtain several model structures on DblCat, the category of small double categories. Our model structures have three sources. We first transfer across a categorification-nerve adjunction. Secondly, we view double categories as internal categories in Cat and take as our weak equivalences various internal equivalences defined via Grothendieck topologies. Thirdly, DblCat inherits a model structure as a category of algebras over a 2-monad. Some of these model structures coincide and the different points of view give us further results about cofibrant replacements and cofi brant objects. As part of this program we give explicit descriptions and discuss properties of free double categories, quotient double categories, colimits of double categories, and several nerves and categorifications

    Standardized Screening for Mental Health Needs of Detained Youths from Various Ethnic Origins: The Dutch Massachusetts Youth Screening Instrument-Second Version (MAYSI-2)

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    In the U.S., the Massachusetts Youth Screening Instrument-Second Version (MAYSI-2) has been shown to be a reliable and valid tool to identify youth with mental health needs upon entry in detention facilities. The present study examined the factor structure, internal consistency, and convergent validity of the Dutch MAYSI-2 administered as part of routine clinical assessments in up to 955 detained male adolescents. Standardized mental health screening questionnaires (Youth Self-Report and Strengths and Difficulties Questionnaire) were used to test the convergent validity of the Dutch MAYSI-2. Confirmatory factor analyses showed that the factor structure of the original MAYSI-2 could be replicated with the Dutch MAYSI-2. Internal consistency indices showed that the Dutch MAYSI-2 provides a reliable screening of mental health needs. In addition, the Dutch MAYSI-2 scales were related with conceptually parallel measures of the same targeted mental health needs in the total group. With a few exceptions, the internal consistency and convergent validity was supported across ethnic groups as well. Overall, these results suggest the psychometric properties of the Dutch MAYSI-2 to be promising. Implications and limitations of the current study\u27s findings and directions for future research are discussed

    Combining web-based attentional bias modification and approach bias modification as a self-help smoking intervention for adult smokers seeking online help: Double-blind randomized controlled trial

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    Background: Automatically activated cognitive motivational processes such as the tendency to attend to or approach smoking-related stimuli (ie, attentional and approach bias) have been related to smoking behaviors. Therefore, these cognitive biases are thought to play a role in maintaining smoking behaviors. Cognitive biases can be modified with cognitive bias modification (CBM), which holds promise as an easy-access and low-cost online intervention. However, little is known about the effectiveness of online interventions combining two varieties of CBM. Targeting multiple cognitive biases may improve treatment outcomes because these biases have been shown to be relatively independent. Objective: This study aimed to test the individual and combined effects of two web-based CBM varieties-attentional bias modification (AtBM) and approach bias modification (ApBM)-in a double-blind randomized controlled trial (RCT) with a 2 (AtBM: Active versus sham) × 2 (ApBM: Active versus sham) factorial design. Methods: A total of 504 adult smokers seeking online help to quit smoking were randomly assigned to 1 of 4 experimental conditions to receive 11 fully automated CBM training sessions. To increase participants' intrinsic motivation to change their smoking behaviors, all participants first received brief, automated, tailored feedback. The primary outcome was point prevalence abstinence during the study period. Secondary outcomes included daily cigarette use and attentional and approach bias. All outcomes were repeatedly self-assessed online from baseline to the 3-month follow-up. For the examination of training effects on outcome changes, an intention-to-treat analysis with a multilevel modeling (MLM) approach was adopted. Results: Only 10.7% (54/504) of the participants completed all 11 training sessions, and 8.3% (42/504) of the participants reached the 3-month follow-up assessment. MLM showed that over time, neither AtBM or ApBM nor a combination of both differed from their respective sham training in point prevalence abstinence rates (P=.17, P=.56, and P=.14, respectively), and in changes in daily cigarette use (P=.26, P=.08, and P=.13, respectively), attentional bias (P=.07, P=.81, and P=.15, respectively), and approach bias (P=.57, P=.22, and P=.40, respectively), while daily cigarette use decreased over time across conditions for all participants (P<.001). Conclusions: This RCT pro

    Obesity, starch digestion and amylase: association between copy number variants at human salivary (AMY1) and pancreatic (AMY2) amylase genes

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    The human salivary amylase genes display extensive copy number variation (CNV), and recent work has implicated this variation in adaptation to starch-rich diets, and in association with body mass index. In this work, we use paralogue ratio tests, microsatellite analysis, read depth and fibre-FISH to demonstrate that human amylase CNV is not a smooth continuum, but is instead partitioned into distinct haplotype classes. There is a fundamental structural distinction between haplotypes containing odd or even numbers of AMY1 gene units, in turn coupled to CNV in pancreatic amylase genes AMY2A and AMY2B. Most haplotypes have one copy each of AMY2A and AMY2B and contain an odd number of copies of AMY1; consequently, most individuals have an even total number of AMY1. In contrast, haplotypes carrying an even number of AMY1 genes have rearrangements leading to CNVs ofAMY2A/AMY2B. Read-depth and experimental data showthat different populations harbour different proportions of these basic haplotype classes. In Europeans, the copy numbers of AMY1 and AMY2A are correlated, so that phenotypic associations caused by variation in pancreatic amylase copy number could be detected indirectly as weak association with AMY1 copy number.We showthat the quantitative polymerase chain reaction (qPCR) assay previously applied to the high-throughput measurement of AMY1 copy number is less accurate than the measures we use and that qPCR data in other studies have been further compromised by systematic miscalibration. Our results uncover new patterns in human amylase variation and imply a potential role for AMY2 CNV in functional associations

    Utilization of community pharmacy space to enhance privacy: A qualitative study

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    © 2015 The Authors. Background: Community pharmacists require access to consumers' information about their medicines and health-related conditions to make informed decisions regarding treatment options. Open communication between consumers and pharmacists is ideal although consumers are only likely to disclose relevant information if they feel that their privacy requirements are being acknowledged and adhered to. Objective: This study sets out to explore community pharmacy privacy practices, experiences and expectations and the utilization of available space to achieve privacy. Methods: Qualitative methods were used, comprising a series of face-to-face interviews with 25 pharmacists and 55 pharmacy customers in Perth, Western Australia, between June and August 2013. Results: The use of private consultation areas for certain services and sensitive discussions was supported by pharmacists and consumers although there was recognition that workflow processes in some pharmacies may need to change to maximize the use of private areas. Pharmacy staff adopted various strategies to overcome privacy obstacles such as taking consumers to a quieter part of the pharmacy, avoiding exposure of sensitive items through packaging, lowering of voices, interacting during pharmacy quiet times and telephoning consumers. Pharmacy staff and consumers regularly had to apply judgement to achieve the required level of privacy. Discussion: Management of privacy can be challenging in the community pharmacy environment, and on-going work in this area is important. As community pharmacy practice is increasingly becoming more involved in advanced medication and disease state management services with unique privacy requirements, pharmacies' layouts and systems to address privacy challenges require a proactive approach
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