• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 359
  • 1
  • 1
  • Tagged with
  • 361
  • 361
  • 358
  • 349
  • 295
  • 232
  • 232
  • 230
  • 188
  • 188
  • 188
  • 149
  • 127
  • 126
  • 126
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

BMI, physical inactivity, cigarette and alcohol consumption in female nursing students: a 5-year comparison

Lehmann, Franziska, von Lindeman, Katharina, Klewer, Jörg, Kugler, Joachim 14 July 2014 (has links) (PDF)
Background: Nursing staff are often involved in counseling patients with regard to health behavior. Although care promoting healthy lifestyle choices is included in the curriculum of nursing students in Germany, several studies of nursing students have reported a high prevalence of unhealthy behavior. This paper focuses on the behavior of female nursing students with regard to body mass index (BMI), physical activity, and cigarette and alcohol consumption. It describes trends through the comparison of results from 2008 and 2013. Methods: Data was collected in two waves at a regional medical training college. First, 301 nursing students were asked to fill out a 12 page questionnaire on health behavior in 2008. The questioning was repeated in 2013 with 316 participating nursing students using the previous questionnaire. Results: 259 female nursing students completed the questionnaire in 2013. 31.6% of them were either overweight or obese, 28.5% exercised less than once a week, 42.9% smoked between 10 and 20 cigarettes a day and 72.6% drank alcohol, wherefrom 19.7% consumed alcohol in risky quantities. In comparison to the data of 266 female nursing students from 2008, there were significant differences in the BMI and alcohol consumption: The percentage of overweight and obese students and the percentage of alcohol consumers at risk increased significantly. Conclusions: Health behavior of female nursing students is often inadequate especially in regard to weight and cigarette and alcohol consumption. Strategies are required to promote healthy lifestyle choices.
162

Work-related complaints and diseases of physical therapists – protocol for the establishment of a “Physical Therapist Cohort” (PTC) in Germany

Girbig, Maria, Deckert, Stefanie, Kopkow, Christian, Latza, Ute, Dulon, Madeleine, Nienhaus, Albert, Groneberg, David, Seidler, Andreas 07 July 2014 (has links) (PDF)
Background: Only few studies deal with the workload of physical therapists and the health consequences, although this occupational group is quite important for the health care system in many industrialized countries (e.g. ca. 136 000 people are currently employed as physical therapists in Germany). Therefore, the current state of knowledge of work-related diseases and disorders of physical therapists is insufficient. The aim of the "Physical Therapist Cohort" (PTC) study is to analyze the association between work-related exposures and diseases among physical therapists in Germany. This article describes the protocol of the baseline assessment of the PTC study. Methods/Design: A cross-sectional study will be conducted as baseline assessment and will include a representative random sample of approximately 300 physical therapists employed in Germany (exposure group), and a population-based comparison group (n = 300). The comparison group will comprise a sample of working aged (18–65 years) inhabitants of a German city. Variables of interest will be assessed using a questionnaire manual including questions regarding musculoskeletal, dermal, and infectious diseases and disorders as well as psychosocial exposures, diseases and disorders. In addition to subjective measures, a clinical examination will be used to objectify the questionnaire-based results (n = 50). Discussion: The study, which includes extensive data collection, provides a unique opportunity to study the prospective association of work-related exposures and associated complaints of physical therapists. Baseline results will give first clues with regard to whether and how prevalent main exposures of physiotherapeutic work and typical work areas of physical therapists are associated with the development of work-related diseases. Thereby, this baseline assessment provides the basis for further investigations to examine causal relationships in accordance with a longitudinal design.
163

Fear Processing in Dental Phobia during Crossmodal Symptom Provocation: An fMRI Study

Hilbert, Kevin, Evens, Ricarda, Maslowski, Nina Isabel, Wittchen, Hans-Ulrich, Lüken, Ulrike 09 July 2014 (has links) (PDF)
While previous studies successfully identified the core neural substrates of the animal subtype of specific phobia, only few and inconsistent research is available for dental phobia. These findings might partly relate to the fact that, typically, visual stimuli were employed. The current study aimed to investigate the influence of stimulus modality on neural fear processing in dental phobia. Thirteen dental phobics (DP) and thirteen healthy controls (HC) attended a block-design functional magnetic resonance imaging (fMRI) symptom provocation paradigm encompassing both visual and auditory stimuli. Drill sounds and matched neutral sinus tones served as auditory stimuli and dentist scenes and matched neutral videos as visual stimuli. Group comparisons showed increased activation in the insula, anterior cingulate cortex, orbitofrontal cortex, and thalamus in DP compared to HC during auditory but not visual stimulation. On the contrary, no differential autonomic reactions were observed in DP. Present results are largely comparable to brain areas identified in animal phobia, but also point towards a potential downregulation of autonomic outflow by neural fear circuits in this disorder. Findings enlarge our knowledge about neural correlates of dental phobia and may help to understand the neural underpinnings of the clinical and physiological characteristics of the disorder.
164

Enhanced Passive RF-DC Converter Circuit Efficiency for Low RF Energy Harvesting

Chaour, Issam, Fakhfakh, Ahmed, Kanoun, Olfa 02 May 2017 (has links) (PDF)
For radio frequency energy transmission, the conversion efficiency of the receiver is decisive not only for reducing sending power, but also for enabling energy transmission over long and variable distances. In this contribution, we present a passive RF-DC converter for energy harvesting at ultra-low input power at 868 MHz. The novel converter consists of a reactive matching circuit and a combined voltage multiplier and rectifier. The stored energy in the input inductor and capacitance, during the negative wave, is conveyed to the output capacitance during the positive one. Although Dickson and Villard topologies have principally comparable efficiency for multi-stage voltage multipliers, the Dickson topology reaches a better efficiency within the novel ultra-low input power converter concept. At the output stage, a low-pass filter is introduced to reduce ripple at high frequencies in order to realize a stable DC signal. The proposed rectifier enables harvesting energy at even a low input power from −40 dBm for a resistive load of 50 kΩ. It realizes a significant improvement in comparison with state of the art solutions
165

Experimental observation and quantum chemical investigation of thallium(I) (Z)-methanediazotate: synthesis of a long sought and highly reactive species

Singh, Neeraj, Fiedler, Benjamin, Friedrich, Joachim, Banert, Klaus 28 April 2017 (has links) (PDF)
For the first time, successful synthesis and characterisation of the missing (Z)-isomer of thallium(I) methanediazotate has been accomplished, utilising low-temperature NMR monitoring analysis. The title compound was synthesised from N-methyl-N-nitrosourea and thallium(I) propoxide, under sub-ambient temperature conditions, as a highly moisture sensitive entity. Quantum chemical calculations, performed at the CCSD(T) level, depict excellent conformity to experimental results. Indeed, compared to its (E) counterpart, the formation of the title compound is thermodynamically less favoured, but preferred by means of kinetic control owing to a hindered isomerisation.
166

Timing and expectation of reward: a neuro-computational model of the afferents to the ventral tegmental area

Vitay , Julien, Hamker, Fred H. 08 July 2014 (has links) (PDF)
Neural activity in dopaminergic areas such as the ventral tegmental area is influenced by timing processes, in particular by the temporal expectation of rewards during Pavlovian conditioning. Receipt of a reward at the expected time allows to compute reward-prediction errors which can drive learning in motor or cognitive structures. Reciprocally, dopamine plays an important role in the timing of external events. Several models of the dopaminergic system exist, but the substrate of temporal learning is rather unclear. In this article, we propose a neuro-computational model of the afferent network to the ventral tegmental area, including the lateral hypothalamus, the pedunculopontine nucleus, the amygdala, the ventromedial prefrontal cortex, the ventral basal ganglia (including the nucleus accumbens and the ventral pallidum), as well as the lateral habenula and the rostromedial tegmental nucleus. Based on a plausible connectivity and realistic learning rules, this neuro-computational model reproduces several experimental observations, such as the progressive cancelation of dopaminergic bursts at reward delivery, the appearance of bursts at the onset of reward-predicting cues or the influence of reward magnitude on activity in the amygdala and ventral tegmental area. While associative learning occurs primarily in the amygdala, learning of the temporal relationship between the cue and the associated reward is implemented as a dopamine-modulated coincidence detection mechanism in the nucleus accumbens.
167

Temperature-Compensated Force/Pressure Sensor Based on Multi-Walled Carbon Nanotube Epoxy Composites

Dinh, Nghia Trong, Kanoun, Olfa 10 November 2015 (has links) (PDF)
In this study, we propose a multi-walled carbon nanotube epoxy composite sensor for force and pressure sensing in the range of 50 N–2 kN. A manufacturing procedure, including material preparation and deposition techniques, is proposed. The electrode dimensions and the layer thickness were optimized by the finite element method. Temperature compensation is realized by four nanocomposites elements, where only two elements are exposed to the measurand. In order to investigate the influence of the filler contents, samples with different compositions were prepared and investigated. Additionally, the specimens are characterized by cyclical and stepped force/pressure loads or at defined temperatures. The results show that the choice of the filler content should meet a compromise between sensitivity, temperature influence and noise behavior. At constant temperature, a force of at least 50N can be resolved. The measurement error due to the temperature influence is 150N in a temperature range of –20°C–50°C.
168

Advanced Joining Technologies for Load and Fibre Adjusted FRP-Metal Hybrid Structures

Klein, Mario, Podlesak , Frank, Höfer, Kevin, Seidlitz, Holger, Gerstenberger, Colin, Mayr, Peter, Kroll, Lothar 27 August 2015 (has links) (PDF)
Multi-material-design (MMD) is commonly realized through the combination of thin sheet metal and fibre reinforced plastics (FRP). To maximize the high lightweight potential of the material groups within a multi-material system as good as possible, a material-adapted and particularly fibre adjusted joining technology must be applied. The present paper focuses on two novel joining technologies, the Flow Drill Joining (FDJ) method and Spin-Blind-Riveting (SBR), which were developed for joining heavy-duty metal/composite hybrids. Tests were carried out with material combinations which are significant for lightweight constructions such as aluminium (AA5083) and carbon fibre-reinforced polyamide in sheet thickness of 1.8 mm. The mechanical testing and manufacturing of those multi-material joints was investigated.
169

Causes and Consequences of Schadenfreude and Sympathy: A Developmental Analysis

Schindler, Rose, Körner, André, Bauer, Sylvia, Hadji, Sarina, Rudolph, Udo 11 November 2015 (has links) (PDF)
Moral judgments and moral emotions are a ubiquitous feature of social interactions. Humans decide quickly and intuitively whether an action is morally right or wrong. Schadenfreude and sympathy, as emotional reactions to the misfortunes of others, are prototypical moral emotions. So far, however, little evidence exists concerning children’s understanding of schadenfreude. Within three studies, we investigated the experience of schadenfreude and sympathy among N = 364 children of different age groups. We interviewed the children while showing them picture stories. In the picture stories, we varied the behavior of the protagonist prior to a misfortune: (1) whether his behavior had been morally right or wrong, (2) whether the protagonist attained his goal, (3) whether the protagonist was responsible for the misfortune. In addition, in one study we varied (4) the emotional relationship of the interviewed children to the protagonist. Furthermore, we asked the children to decide whether they want to sit next to the protagonist or do him a favor. Results show that children experience sympathy as well as schadenfreude at the age of 4 years. Sympathy is more likely to arise when the protagonists of a story are likable, when these actors typically pursue morally positive goals, and if they are not responsible for their misfortune. In contrast, schadenfreude is more likely when the protagonist is disliked, when actors pursue immoral goals and if they are responsible for their misfortune. In addition, sympathy increases approach (helping behavior, sitting next to the agent and doing favors), whereas schadenfreude increases avoidance tendencies.
170

ANNarchy: a code generation approach to neural simulations on parallel hardware

Vitay, Julien, Dinkelbach, Helge Ülo, Hamker, Fred Henrik 07 October 2015 (has links) (PDF)
Many modern neural simulators focus on the simulation of networks of spiking neurons on parallel hardware. Another important framework in computational neuroscience, rate-coded neural networks, is mostly difficult or impossible to implement using these simulators. We present here the ANNarchy (Artificial Neural Networks architect) neural simulator, which allows to easily define and simulate rate-coded and spiking networks, as well as combinations of both. The interface in Python has been designed to be close to the PyNN interface, while the definition of neuron and synapse models can be specified using an equation-oriented mathematical description similar to the Brian neural simulator. This information is used to generate C++ code that will efficiently perform the simulation on the chosen parallel hardware (multi-core system or graphical processing unit). Several numerical methods are available to transform ordinary differential equations into an efficient C++code. We compare the parallel performance of the simulator to existing solutions.

Page generated in 0.1066 seconds