Finite Element Analysis of Temperature Field in Automotive Dry Friction Clutch

The friction clutch design is strongly dependent upon the frictional heat generated between contact surfaces during the slipping at beginning of engagement. Because of that the frictional heat generated firstly will reduce the performance of clutch system and then will lead to premature failure in some cases. Finite element method was used to investigate aneffect of thermal load type on the temperature field of the clutch system. Two-dimensional axisymmetric model was used to study the temperature distribution for the clutch system (pressure plate, clutch disc and flywheel) during heating phase (slipping period) and in the cooling phase (full engagement period). Depending on basic friction clutch design two types of thermal loads were applied; load type A (uniform pressure) and load type B (uniform wear). Repeated engagements made at regular interval wereconsidered in this work. ANSYS13 has been used to perform the numerical calculation in this paper

Procalcitonin-guided therapy in intensive care unit patients with severe sepsis and septic shock – a systematic review and meta-analysis

INTRODUCTION: Procalcitonin (PCT) algorithms for antibiotic treatment decisions have been studied in adult patients from primary care, emergency department, and intensive care unit (ICU) settings, suggesting that procalcitonin-guided therapy may reduce antibiotic exposure without increasing the mortality rate. However, information on the efficacy and safety of this approach in the most vulnerable population of critically ill patients with severe sepsis and septic shock is missing. METHOD: Two reviewers independently performed a systematic search in PubMed, Embase, ISI Web of Knowledge, BioMed Central, ScienceDirect, Cochrane Central Register of Controlled Trials, http://www.ClinicalTrials.gov and http://www.ISRCTN.org. Eligible studies had to be randomized controlled clinical trials or cohort studies which compare procalcitonin-guided therapy with standard care in severe sepsis patients and report at least one of the following outcomes: hospital mortality, 28-day mortality, duration of antimicrobial therapy, length of stay in the intensive care unit or length of hospital stay. Disagreements about inclusion of studies and judgment of bias were solved by consensus. RESULTS: Finally seven studies comprising a total of 1,075 patients with severe sepsis or septic shock were included in the meta-analysis. Both hospital mortality (RR [relative risk]: 0.91, 95%CI [confidence interval]: 0.61; 1.36) and 28-day mortality (RR: 1.02, 95%CI: 0.85; 1.23) were not different between procalcitonin-guided therapy and standard treatment groups. Duration of antimicrobial therapy was significantly reduced in favor of procalcitonin-guided therapy (HR [hazard ratio]: 1.27, 95%CI: 1.01; 1.53). Combined estimates of the length of stay in the ICU and in hospital did not differ between groups. CONCLUSION: Procalcitonin-guided therapy is a helpful approach to guide antibiotic therapy and surgical interventions without a beneficial effect on mortality. The major benefit of PCT-guided therapy consists of a shorter duration of antibiotic treatment compared to standard care. Trials are needed to investigate the effect of PCT-guided therapy on mortality, length of ICU and in-hospital stay in severe sepsis patients

Zoonotic multidrug-resistant microorganisms among non-hospitalized horses from Germany

Colonization with multidrug-resistant organisms (MDROs) belonging to the genus Staphylococcus and the order Enterobacterales poses a particular threat to populations at risk. While previous studies focused on MDRO carriage among livestock or companion animals, respective epidemiological data on the general equine population are limited. Here, carriage of methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum beta-lactamase (ESBL) producing Enterobacteriaceae (ESBL-E) in non-hospitalized horses living on private farms in the rural area in Northwest Germany was assessed. Intranasal and perianal swab samples were cultured on solid chromogenic media directly and after enrichment in tryptic soy broth, respectively. S. aureus isolates were spa-typed, MRSA and ESBL-E were further classified by phenotypic and molecular methods. Additionally, a subgroup of the first 20 samples was used to isolate and characterize staphylococci other than S. aureus. Among 223 horses, fifteen (6.8%) carried S. aureus. Two isolates were identified as MRSA (0.9% of all horses, mecA-positive) and classified as spa types t011 and t6867, both known as members of the livestock-associated MRSA MLST clonal complex 398. Nine horses (4.0%) were colonized by ESBL-Escherichia coli positive for blaCTX-M and/or blaTEM. ESBL-E carriage was associated with prior antibiotic treatment (4/31 vs. 5/183; p = 0.0362) and veterinary examinations (4/31 vs. 5/183; p = 0.0362). In the subgroup, nine different staphylococcal species other than S. aureus were found. The high prevalence of ESBL-E. coli in non-hospitalized horses underlines the necessity to raise awareness for strain dissemination across different hosts in order to do justice to the “One Health” concept

Selective carious tissue removal using subjective criteria or polymer bur: study protocol for a randomised controlled trial (SelecCT)

Introduction: Selective (incomplete/partial) carious tissue removal is suitable for treating deep carious lesions in teeth with vital, asymptomatic pulps. In the periphery of a cavity, removal to hard dentin is performed, while in pulpo-proximal areas, leathery or soft dentin is left to avoid pulp exposure. As the decision of what contains 'soft' or 'leathery' dentin is subjective, using self-limiting burs which help to standardise the hardness of the remaining dentin, has been suggested to increase the reliability of carious tissue removal. The trial compares subjectively measured selective carious tissue removal in deep lesions in primary teeth with objectively measured selective removal with a self-limiting bur (Polybur, Komet). Methods and analysis: A community-based single-blind clustered randomised controlled superiority trial nested into a larger evaluation is performed. Recruitment for this trial has been concluded. We have recruited 115 children aged 6-8 years with >= 1 vital primary molar with a deep dentin lesion. The unit of randomisation was the child, with all eligible molars per child treated identically. Treatment was performed in a mobile dental unit. Subjective and objective carious tissue removal was performed at random. Teeth were restored using glass ionomer cement (Equia Forte, GC). Our primary outcome will be the time until complications occur, evaluated via multilevel survival analysis. Secondary outcomes will be the time until extraction is needed, subjective satisfaction of the child with the treatment (measured using a Likert scale) and cost-effectiveness. Re-examination will be performed after 12, 24 and 36 months (the final examination is expected in 2020). Ethics and dissemination: This trial has been approved by the Ethics Committee of the Health Sciences of the University of Brasilia (CAAE 51310415.0.0000.0030). Trial results will be published in peer-reviewed journals and presented on conferences

Ignorant Experts – Heightened Confidence Undermines the Beneficial Effect of a Forewarning About the Anchoring Effect

Anchoring effects are remarkably robust and difficult to correct. Forewarnings about the influence of anchor values have not led to a reduction of the anchoring effect (Wilson, Houston, Etling, & Brekke, 1996). Overconfidence constitutes a potential reason for the failure of forewarnings because it may affect people’s awareness about their vulnerability to influences. As experts are particularly overconfident when making judgments (Törngren & Montgomery, 2004), they are expected to be even less responsive to forewarnings than non-experts in reducing the magnitude of the anchoring effect. In Studies 1 to 3, expertise was operationalized through different experience levels. Students either had experience with an anchoring task (e.g., estimation of a flat rent) or were unfamiliar with it (e.g., estimation of a company value). In Study 4, experts (management consultants) and non-experts (students) were directly compared while performing economic anchoring tasks. First, half of the participants received an overconfidence note (Study 1) or their confidence was reduced by difficult general knowledge questions (Studies 2 to 4). Afterwards, half of the participants received a forewarning about the anchoring effect. As predicted, forewarnings reduced the magnitude of anchoring in the low expertise conditions. More importantly, the magnitude of anchoring was also reduced in the high expertise conditions, but only after a confidence reduction (Studies 2 to 4), whereas an explicit overconfidence note (Study 1) failed to produce the same effect (Study 1). For management consultants who received a forewarning, the effect of the confidence reduction on the magnitude of anchoring was mediated by the degree of confidence (Study 4). Taken together, higher confidence of experts can explain why expertise impedes the effectiveness of forewarnings about anchoring effects. However, reducing experts’ confidence can render a forewarning effective even in the case of high expertise. Directions for future research and practical implications are discussed

Essays in Macroeconomics

Understanding the role of public policy in shaping individual behavior, and thus broader economic outcomes, is fundamental to the design of effective policy interventions. Individuals do not make decisions in a vacuum: their choices are shaped by incentives, constraints, and the economic and institutional context in which they operate. This dissertation contributes to the ongoing discussion by examining how individual decisions interact with the design of public policies in two areas that are both economically and politically salient: social mobility and climate policy. Across three chapters, I investigate how structural features of the economic environment, such as regional disparities in labor demand and heterogeneity in household carbon emissions, mediate the effects of policy interventions. These features shape not only how individuals respond to policies, but also who benefits and who bears the costs, with significant implications for both the effectiveness of policies and their distributional consequences. Chapter 1 explores how regional labor demand influences the persistence of occupational choices across generations, affecting income mobility. The study finds that accounting for regional and occupation-specific demand reduces occupational persistence by up to 10%, highlighting the importance of addressing regional disparities in job opportunities to improve social mobility. Chapters 2 and 3 examine the distributional impacts of climate policies, focusing on carbon taxation and subsidies for carbon-neutral technologies. Chapter 2 finds that policies aimed at quickly reducing emissions, like carbon taxes with subsidies, tend to redistribute wealth from low- to high-income households, but financing them through progressive income taxes can balance emissions reductions with broader political support. Chapter 3 highlights regional differences, showing that rural households have higher carbon footprints than urban ones and proposing mechanisms like place-based transfers to avoid unfair redistribution and maintain political support for climate policies

Real-Time Markerless Tracking the Human Hands for 3D Interaction

This thesis presents methods for enabling suitable human computer interaction using only movements of the bare human hands in free space. This kind of interaction is natural and intuitive, particularly because actions familiar to our everyday life can be reflected. Furthermore, the input is contact-free which is of great advantage e.g. in medical applications due to hygiene factors. For enabling the translation of hand movements to control signals an automatic method for tracking the pose and/or posture of the hand is needed. In this context the simultaneous recognition of both hands is desirable to allow for more natural input. The first contribution of this thesis is a novel video-based method for real-time detection of the positions and orientations of both bare human hands in four different predefined postures, respectively. Based on such a system novel interaction interfaces can be developed. However, the design of such interfaces is a non-trivial task. Additionally, the development of novel interaction techniques is often mandatory in order to enable the design of efficient and easily operable interfaces. To this end, several novel interaction techniques are presented and investigated in this thesis, which solve existing problems and substantially improve the applicability of such a new device. These techniques are not restricted to this input instrument and can also be employed to improve the handling of other interaction devices. Finally, several new interaction interfaces are described and analyzed to demonstrate possible applications in specific interaction scenarios.Markerlose Verfolgung der menschlichen Hände in Echtzeit für 3D Interaktion In der vorliegenden Arbeit werden Verfahren dargestellt, die sinnvolle Mensch- Maschine-Interaktionen nur durch Bewegungen der bloßen Hände in freiem Raum ermöglichen. Solche "natürlichen" Interaktionen haben den besonderen Vorteil, dass alltägliche und vertraute Handlungen in die virtuelle Umgebung übertragen werden können. Außerdem werden auf diese Art berührungslose Eingaben ermöglicht, nützlich z.B. wegen hygienischer Aspekte im medizinischen Bereich. Um Handbewegungen in Steuersignale umsetzen zu können, ist zunächst ein automatisches Verfahren zur Erkennung der Lage und/oder der Art der mit der Hand gebildeten Geste notwendig. Dabei ist die gleichzeitige Erfassung beider Hände wünschenswert, um die Eingaben möglichst natürlich gestalten zu können. Der erste Beitrag dieser Arbeit besteht aus einer neuen videobasierten Methode zur unmittelbaren Erkennung der Positionen und Orientierungen beider Hände in jeweils vier verschiedenen, vordefinierten Gesten. Basierend auf einem solchen Verfahren können neuartige Interaktionsschnittstellen entwickelt werden. Allerdings ist die Ausgestaltung solcher Schnittstellen keinesfalls trivial. Im Gegenteil ist bei einer neuen Art der Interaktion meist sogar die Entwicklung neuer Interaktionstechniken erforderlich, damit überhaupt effiziente und gut bedienbare Schnittstellen konzipiert werden können. Aus diesem Grund wurden in dieser Arbeit einige neue Interaktionstechniken entwickelt und untersucht, die vorhandene Probleme beheben und die Anwendbarkeit eines solchen Eingabeinstruments für bestimmte Arten der Interaktion verbessern oder überhaupt erst ermöglichen. Diese Techniken sind nicht auf dieses Eingabeinstrument beschränkt und können durchaus auch die Handhabung anderer Eingabegeräte verbessern. Des Weiteren werden mehrere neue Interaktionsschnittstellen präsentiert, die den möglichen Einsatz bloßhändiger Interaktion in verschiedenen, typischen Anwendungsgebieten veranschaulichen

Inhibition of the potassium channel Kv1.3 reduces infarction and inflammation in ischemic stroke.

ObjectiveInhibitors of the voltage-gated K+ channel Kv1.3 are currently in development as immunomodulators for the treatment of autoimmune diseases. As Kv1.3 is also expressed on microglia and has been shown to be specifically up-regulated on "M1-like" microglia, we here tested the therapeutic hypothesis that the brain-penetrant small-molecule Kv1.3-inhibitor PAP-1 reduces secondary inflammatory damage after ischemia/reperfusion.MethodsWe studied microglial Kv1.3 expression using electrophysiology and immunohistochemistry, and evaluated PAP-1 in hypoxia-exposed organotypic hippocampal slices and in middle cerebral artery occlusion (MCAO) with 8 days of reperfusion in both adult male C57BL/6J mice (60 min MCAO) and adult male Wistar rats (90 min MCAO). In both models, PAP-1 administration was started 12 h after reperfusion.ResultsWe observed Kv1.3 staining on activated microglia in ischemic infarcts in mice, rats, and humans and found higher Kv1.3 current densities in acutely isolated microglia from the infarcted hemisphere than in microglia isolated from the contralateral hemisphere of MCAO mice. PAP-1 reduced microglia activation and increased neuronal survival in hypoxia-exposed hippocampal slices as effectively as minocycline. In mouse MCAO, PAP-1 dose-dependently reduced infarct area, improved neurological deficit score, and reduced brain levels of IL-1β and IFN-γ without affecting IL-10 and brain-derived nerve growth factor (BDNF) levels or inhibiting ongoing phagocytosis. The beneficial effects on infarct area and neurological deficit score were reproduced in rats providing confirmation in a second species.InterpretationOur findings suggest that Kv1.3 constitutes a promising therapeutic target for preferentially inhibiting "M1-like" inflammatory microglia/macrophage functions in ischemic stroke

The Impact of Work-Based Learning on Graduates Job Performance: Insights from School-in-Factory (SiF) Project

The School-in-Factory (SiF) is a pilot project for implementing dual technical and vocational education and training in Thailand by using a Work-based Learning approach with the combination of learning and working in the real process of work through the collaboration between the private company and educational institute. This study aims to evaluate the output and outcome of the SiF project by analyzing the program completion rate and the impact of the SiF project on the graduates\u27 job performance in the labour market. The study employed both quantitative and qualitative approaches. The quantitative data is collected from official project records. The qualitative data is collected by using an open-ended. It is found that 85% of the learners from the year 2017-2020 successfully completed the SiF program (100 out of 117 learners). The impact of the SiF program has mostly contributed to the development of subject-oriented competence, that is technical knowledge and skills of the learners. The graduates reported that the SiF program has a positive impact on their performance where knowledge of the work process, ability to adapt to the workplace, and valuable work experience gained during training are the most valued impact. Moreover, from the perspective of the employers, the employees who graduated from the SiF program have shown their competencies in technical proficiency and job professional behaviour, constructive communication and expression, teamwork, job- related problem-solving skills. The results of the study stressed the importance of work-based learning where training at the company and learning at the classroom are combined, like the SiF program, to support learner competency development. The SiF program has shown a strong collaboration with the private company partner in implementing work-based learning in Thailand. Further studies should be conducted to find out the financial benefits of the project.

The Impact of Covariance Misspecification in Multivariate Gaussian Mixtures on Estimation and Inference: An Application to Longitudinal Modeling

Multivariate Gaussian mixtures are a class of models that provide a flexible parametric approach for the representation of heterogeneous multivariate outcomes. When the outcome is a vector of repeated measurements taken on the same subject, there is often inherent dependence between observations. However, a common covariance assumption is conditional independence---that is, given the mixture component label, the outcomes for subjects are independent. In this paper, we study, through asymptotic bias calculations and simulation, the impact of covariance misspecification in multivariate Gaussian mixtures. Although maximum likelihood estimators of regression and mixing probability parameters are not consistent under misspecification, they have little asymptotic bias when mixture components are well-separated or if the assumed correlation is close to the truth even when the covariance is misspecified. We also present a robust standard error estimator and show that it outperforms conventional estimators in simulations and can indicate the model is misspecified. Body mass index data from a national longitudinal study is used to demonstrate the effects of misspecification on potential inferences made in practice