43 research outputs found

    Modeling of plate structures

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    Bei der Planung eines Bauwerkes müssen im voraus Aussagen über das Schalldämmverhalten eines Bauteils getroffen werden, was aufgrund der komplexen Wechselwirkungen zwischen Materialien, Bauelementen und Umgebung sehr schwierig sein kann. Deswegen gewinnen numerische Verfahren zur Berechnung des Schalldurchgangs durch Wände immer mehr an Bedeutung. Da Wände in der Regel aus porösem Material bestehen, z.B. aus Beton oder Ziegeln, ist eine möglichst realitätsnahe Abbildung als poroelastische plattenförmige Bauteile für die Entwicklung eines Verfahrens zur die Berechnung des Schalldurchgangs durch poröse Wände eine sinnvolle Grundlage. Dazu wird die poröse Struktur in geeigneter Weise erfasst und zur numerischen Berechnung als ebenes Flächentragwerk aufbereitet . Dabei wird ein mit Hilfe der Theorie von Biot beschriebenes dreidimensionales poroelastisches Kontinuum mit Hilfe einer Reihenentwicklung bezüglich der Dickenkoordinate in ein zweidimensionales Kontinuum überführt. Einerseits kann die Reihe nach einer bestimmten Ordnung der Freiwerte abgebrochen werden, andererseits besteht die Möglichkeit die Reihenentwicklung nach einer bestimmten Potenz der Plattendicke abzubrechen. Je nach Wahl des Abbruchpunktes entstehen Scheiben- und Plattentheorien unterschiedlicher Ordnung, wobei auf die Scheibentheorien nur kurz eingegangen wird. Die hergeleiteten poroelastischen Plattengleichungen werden in Finite-Element-Formulierungen überführt. Die Plattentheorien unterschiedlicher Ordnung werden miteinander verglichen und anhand von Berechnungen des Verhaltens einer Felsplatte verifiziert. Außerdem wird das Verhalten von einigen Schäumen untersucht.The prediction of the acoustical behavior of a building can be very complicated because of the interaction between material, construction and surrounding. The numerical treatment of noise insulation of solid walls has been an object of scientific research for several years. The main noise source is the bending vibration of the walls modeled by plate theory. In general, walls consist of porous material, e.g., concrete or bricks. Therefore a poroelastic plate theory is useful to establish a basis to develop a numerical model for sound transmission through porous walls. Starting from the 3-D-Formulation for a poroelastic continuum using Biot's Theory, a 2-D theory is established by series expansion of the thickness coordinate. Depending on the point of truncation plate theories of different order are developed. The series can be truncated after a defined order of the thickness coordinate or after a defined power of the plate thickness. A Finite Element methodology is developed to analyze the behaviour of different plates numerically. Plate theories of different order are compared to each other and will be verified by the analysis of a rock plate and a foam plate

    Perspectives on gender and product design

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    International audienceInteractive technologies have a profound mediating effect on the way we obtain and contribute to knowledge, relate to each other and contribute to society. Often, "gender" is not a factor that is explicitly considered in the design of these technologies. When gender is considered, products are often designed with idealised models of gendered "users" -- designed for men, designed for women, designed for boys, designed for girls, or designed for the "average user" who could be male or female. However, the ways in which gender-bias or gender-neutrality are constructed in the design process and the resulting effect on the interactive artifacts that are produced is not well understood. This workshop will address what HCI is currently bringing, and can bring, to the table in addressing this issue

    Negative Regulation of Bone Formation by the Transmembrane Wnt Antagonist Kremen-2

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    Wnt signalling is a key pathway controlling bone formation in mice and humans. One of the regulators of this pathway is Dkk1, which antagonizes Wnt signalling through the formation of a ternary complex with the transmembrane receptors Krm1/2 and Lrp5/6, thereby blocking the induction of Wnt signalling by the latter ones. Here we show that Kremen-2 (Krm2) is predominantly expressed in bone, and that its osteoblast-specific over-expression in transgenic mice (Col1a1-Krm2) results in severe osteoporosis. Histomorphometric analysis revealed that osteoblast maturation and bone formation are disturbed in Col1a1-Krm2 mice, whereas bone resorption is increased. In line with these findings, primary osteoblasts derived from Col1a1-Krm2 mice display a cell-autonomous differentiation defect, impaired canonical Wnt signalling and decreased production of the osteoclast inhibitory factor Opg. To determine whether the observed effects of Krm2 on bone remodeling are physiologically relevant, we analyzed the skeletal phenotype of 24 weeks old Krm2-deficient mice and observed high bone mass caused by a more than three-fold increase in bone formation. Taken together, these data identify Krm2 as a regulator of bone remodeling and raise the possibility that antagonizing KRM2 might prove beneficial in patients with bone loss disorders

    How does mental health care perform in respect to service users' expectations? Evaluating inpatient and outpatient care in Germany with the WHO responsiveness concept

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    <p>Abstract</p> <p>Background</p> <p>Health systems increasingly try to make their services more responsive to users' expectations. In the context of the World Health Report 2000, WHO developed the concept of health system <it>responsiveness </it>as a performance parameter. <it>Responsiveness </it>relates to the system's ability to respond to service users' legitimate expectations of non-medical aspects. We used this concept in an effort to evaluate the performance of mental health care in a catchment area in Germany.</p> <p>Methods</p> <p>In accordance with the method WHO used for its <it>responsiveness </it>survey, <it>responsiveness </it>for inpatient and outpatient mental health care was evaluated by a standardised questionnaire. <it>Responsiveness </it>was assessed in the following domains: <it>attention, dignity</it>, <it>clear communication</it>, <it>autonomy, confidentiality, basic amenities, choice </it>of health care provider, <it>continuity</it>, and <it>access to social support</it>. Users with complex mental health care needs (i.e., requiring social and medical services or inpatient care) were recruited consecutively within the mental health services provided in the catchment area of the Hanover Medical School.</p> <p>Results</p> <p>221 persons were recruited in outpatient care and 91 in inpatient care. Inpatient service users reported poor <it>responsiveness </it>(22%) more often than outpatients did (15%); however this was significant only for the domains <it>dignity </it>and <it>communication</it>. The best performing domains were <it>confidentiality </it>and <it>dignity</it>; the worst performing were <it>choice</it>, <it>autonomy </it>and <it>basic amenities </it>(only inpatient care). <it>Autonomy </it>was rated as the most important domain, followed by <it>attention </it>and <it>communication</it>. <it>Responsiveness </it>within outpatient care was rated worse by people who had less money and were less well educated. Inpatient <it>responsiveness </it>was rated better by those with a higher level of education and also by those who were not so well educated. 23% of participants reported having been discriminated against in mental health care during the past 6 months.</p> <p>The results are similar to prior <it>responsiveness </it>surveys with regard to the overall better performance of outpatient care. Where results differ, this can best be explained by certain characteristics that are applicable to mental health care and also by the users with complex needs. The expectations of <it>attention </it>and <it>autonomy</it>, including participation in the treatment process, are not met satisfactorily in inpatient and outpatient care.</p> <p>Conclusion</p> <p><it>Responsiveness </it>as a health system performance parameter provides a refined picture of inpatient and outpatient mental health care. Reforms to the services provided should be orientated around domains that are high in importance, but low in performance. Measuring <it>responsiveness </it>could provide well-grounded guidance for further development of mental health care systems towards becoming better patient-orientated and providing patients with more respect.</p

    Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

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    Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

    Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

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    There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

    Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

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    Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

    How farmers think about insects: perceptions of biodiversity, biodiversity loss and attitudes towards insect-friendly farming practices

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    An alarming decrease of insects in number and variety calls for measures of protection and promotion, since insects are crucial for the functioning of ecosystems and provide multiple ecosystem services. Agricultural landscapes can provide vast insect habitats if they are managed accordingly. However, little is known about farmers’ problem awareness and attitudes toward insect biodiversity loss, related farming practises, or alternative acceptable insect-friendly solutions. To fill these research gaps, this paper aimed to reveal farmers’ perceptions and attitudes regarding these aspects in two German case studies. We conducted 23 semi-structured interviews with farmers in 2019 and qualitatively analysed them using semantic web analysis. Farmers mostly reported awareness of insects’ ecosystem services and disservices related to agricultural production rather than mentioning the holistic ecological importance of insects. About half of the farmers confirmed insect loss based on their own observations, whereas a similar number doubted there had been a decrease of insects. Most farmers are open-minded towards insect-friendly measures if financially compensated. The farmers also mentioned a joint societal responsibility for insects, economic pressure on farmers to use pesticides due to global market prices, and unbalanced agricultural policies. This study revealed in-depth insights into farmers’ thinking about insects and how farmers contextualise arguments. Our results identified overlaps in farmers’ mental models, which paves the way for co-designing insect-friendly farming practices in landscape labs. Local transformation efforts can also demonstrate new pathways for a shift on the higher levels

    Prevalence of visceral artery involvement in patients with peripheral artery disease found on run-off MRA

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    Background!#!In patients with peripheral artery disease (PAD), run-off MR-angiography (MRA) is a commonly performed diagnostic test to obtain high-resolution images for evaluation of the arterial system from the aorta through the distal run-off vessels. The aim of this study was to investigate the prevalence of visceral artery involvement (VAI) in patients with PAD and leg symptoms examined with run-off MRA.!##!Methods!#!We retrospectively analyzed 145 patients (median age 68 years, range 27-91) who underwent MRA due to known or suspected PAD at our institution between 2012 and 2018. MRA examinations were re-evaluated for visceral artery stenosis. Patient dossiers were reviewed to determine cardiovascular risk factors, kidney function and Fontaine stage of PAD.!##!Results!#!Involvement of at least one visceral artery with ≥ 50% diameter stenosis was found in 72 (50%) patients. There were no differences in age, gender, MRA indication, Fontaine stage, levels of C-reactive protein (CRP), cardiovascular risk factors or vascular comorbidities between patients with and without VAI. Renal artery (RA) involvement with ≥ 50% diameter stenosis was observed in 28 (20%) of patients. Patients with involvement of the RA were more likely to suffer from hypertension (79 vs. 54%, p = 0.019) and reduced renal function (glomerular filtration rate 70 vs. 88 mL/min/1.73m!##!Conclusion!#!Visceral artery stenosis can be seen in half of patients with known or suspected PAD and leg symptoms on run-off MRA. Investigating for RA stenosis in patients with PAD and hypertension and/or impaired renal function may have high diagnostic yield
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