2,791 research outputs found
Paying for "End-of-Life" Drugs in Australia, Germany, and the United Kingdom: Balancing Policy, Pragmatism, and Societal Values
Analyzes British, Australian, and German health systems' policies on covering expensive end-of-life drugs while maintaining equity and efficiency, such as requiring evidence of comparative clinical and cost-effectiveness. Outlines challenges for the U.S
Strukturelle und elektrische Charakterisierungen ferroelektrischer Feldeffekttransistoren auf Silizium
In heutigen Computersystemen mit stetig steigender Leistung, nehmen Speichermedien eine zunehmend wichtigere Funktion ein. Seitens der Halbleiter-Industrie wird ein erheblicher Aufwand betrieben, um neue Speichermedien zu entwickeln, welche den gestiegenen Anforderungen an ein Speicherelement gerecht werden. Der FeFET � der ferroelektrische Feldeffekttransistor � besitzt ein hohes Anwendungspotential und könnte als nichtflüchtiger-Speicher die bisher in Computern verwendeten Arbeitsspeicher ersetzten. Im Gegensatz zu FeRAMs, bei denen die Information in einem ferroelektrischen Kondensator gespeichert werden (1T1C), wird in einem FeFET eine ferroelektrische Schicht in den Gateschichtstapel eines Feldeffekttransistors integriert; es entsteht eine ein-Transistor- Speicherzelle (1T). Die Integration einer ferroelektrischen Schicht, wie PbZrxTi(1-x)O3 (PZT), in einen Siliziumbasierten Transistor, kann nur mit Hilfe einer zusätzlichen Buffer-Schicht zwischen Ferroelektrikum und dem Silizium-Substrat erfolgen. Diese Arbeit behandelt einerseits die Herstellung und Charakterisierung dielektrischer Bufferschichten auf Silizium, andererseits die Charakterisierung ferroelektrischer Gateschichten unter Verwendung der untersuchten Bufferschichten. Als dielektrische Bufferschichten wurden einkristalline SrTiO3(STO)-, polykristalline CeO2(CeO) und amorphe DyScO3-Schichten auf Silizium abgeschieden und in Form von MOS-Dioden und Transistoren elektrisch charakterisiert. CeO2- und DyScO3- Schichten zeigten geringe Leckströme, eine Dielektrizitätskonstante von epsilon = 25 und eine geringe Anzahl fester Ladungen in der Schicht. DyScO3-Schichten eignen sich, aufgrund der amorphen Struktur, nur bedingt als Buffer für ferroelektrische Schichten, könnten aber als Austauschmaterial für SiO2 in FETs benutzt werden (hoch-epsilon-Material). Unter Verwendung des ferroelektrischen Co-Polymers P(VDF-TrFE) konnten MFIS-Dioden und ferroelektrische Transistoren, mit Operationsspannungen unterhalb von 10V auf Basis von SiO2- und DyScO3-Buffer-Schichten hergestellt werden
Replication study: a cross-country field observation study of real world PIN usage at ATMs and in various electronic payment scenarios:towards understanding why people do, or do not, shield PIN entry
In this paper, we describe the study we carried out to replicate and extend the field observation study of real world ATM use carried out by De Luca et al., published at the SOUPS conference in 2010. Replicating De Luca et al.'s study, we observed PIN shielding rates at ATMs in Germany. We then extended their research by conducting a similar field observation study in Sweden and the United Kingdom. Moreover, in addition to observing ATM users (withdrawing), we also observed electronic payment scenarios requiring PIN entry. Altogether, we gathered data related to 930 observations. Similar to De Luca et al., we conducted follow-up interviews, the better to interpret our findings. We were able to confirm De Luca et al.'s findings with respect to low PIN shielding incidence during ATM cash withdrawals, with no significant differences between shielding rates across the three countries. PIN shielding incidence during electronic payment scenarios was significantly lower than incidence during ATM withdrawal scenarios in both the United Kingdom and Sweden. Shielding levels in Germany were similar during both withdrawal and payment scenarios. We conclude the paper by suggesting a number of explanations for the differences in shielding that our study revealed
Excessive working hours and health complaints among hospital physicians: a study based on a national sample of hospital physicians in Germany
Objectives: To determine correlations between excessively long working hours and subjectively experienced somatic health complaints among hospital physicians
Environmental Enrichment and its effects on Welfare in fish
Although public and consumer awareness is increasing fast in regard to welfare in captive fish; one often neglected aspect of fish welfare is the complexity of their holding environment. Increasing the complexity in any given way is termed environmental enrichment. Enriching the environment of fishes can have various positive effects on physiology, health, survival and therefore general welfare. However, it usually is also increasing labor through increasing maintenance and handling time and is lowering thus the efficiency. Fish welfare in general includes also the acceptance that fish can feel a certain degree of pain and should be considered, at least to a certain degree, sentient and conscious beings, which is scientifically still under serious debate.
Under the assumption that fish have the capabilities to feel pain and are, at least to a certain extent, conscious and sentient beings, the often neglected welfare‐aspect of environmental enrichment and its effects on fish under captive conditions are discussed in this review. This includes farmed fish for human consumption and restocking purposes (aquaculture) and fish kept for research. A definition of environmental enrichment is as well provided as a historical context, different enrichment types and the aims of environmental enrichment and areas of its application. Whether or not fish can feel pain is also debated.
An extensive table is included, providing natural micro‐, meso‐ and macrohabitat preferences of some important freshwater salmonids (rainbow and brown trout, Arctic char), Eurasian perch and common carp in different life stages (fry, juveniles, adults). Furthermore the environmental enrichment is considered under the perspective of in‐stream restorations and its effect on, primarily, salmonids in culture. Environmental enrichment includes physical structures added to the captive environment to provide increase the structural complexity while other forms of environmental enrichment may include sensory, social, nutritional or even occupational enrichment. The latter, however, is usually not of higher importance for fish. In the various research papers reviewed, it is obvious that environmental enrichment can provide several beneficial advantages although some negative effects have been observed too. Observations of environmental enrichment effects on a production or farm level are basically completely missing in the literature and therefore a large knowledge gap exists between laboratory studies and practical application. While several types of environmental enrichment have been adapted to aquaculture out of necessity, mainly in terms of reproduction success, little is known of environmental enrichment effects on fish welfare under production conditions and whether benefits may outweigh the drawbacks like increased installation costs or increased effort for maintenance
Fluid leakage past tracheal tube cuffs: evaluation of the new Microcuff endotracheal tube
Objective: This study compared the recently introduced Microcuff endotracheal tube HVLP ICU featuring an ultrathin (7-µm) polyurethane cuff membrane with endotracheal tubes from different manufacturers regarding fluid leakage past the tube cuff. Design: In vitro setup. Measurements and results: The following endotracheal tubes (ID 7.5mm) were compared: Mallinckrodt HiLo, Microcuff HVLP ICU, Portex Profile Soft Seal, Rüsch Super Safety Clear, and Sheridan CF. A vertical PVC trachea model (ID 20mm) was intubated, and cuffs were inflated to 10, 15, 20, 25, 30, and 60cmH2O. Colored water (5ml) was added to the top of the cuff. The amount of leaked fluid past the tube cuff within 5, 10, and 60min was recorded. Experiments were performed four times using two examples of each tube brand. Fluid leakage past tube cuffs occurred in all conventional endotracheal tubes at cuff pressures from 10 to 60cmH2O. In the Microcuff tube cuff pressure fluid leakage was observed within 10min only at 10cmH2O. Results with the Microcuff tube were significantly better than all other tube brands at cuff pressures of 10-30cmH2O. Conclusions: Within the acceptable upper limit for tracheal cuff pressure (25-30cmH2O) the Microcuff endotracheal tube was the only one of the tested tubes to prevent fluid leakage in our in vitro setup. In vivo studies are required to confirm these finding
Flexible Kooperation zwischen Autonomen Agenten in Dynamischen Umgebungen
Die vorliegende Dissertation präsentiert ein Schema zur Holonenformierung
in dynamischen Umgebungen eines holonischen Multiagenten-Systems. Holo-
ne werden dazu eingesetzt, um eine Gruppe von Agenten für einen begrenzten Zeitraum zu einem strukturierten Verbund zusammenzufassen. Unter der
Führung eines ausgezeichneten Agenten, dem Holonenführer bzw. Kopf des Holons, können gemeinsam komplexe Aufgaben gelöst werden. Die Holonenführer,
wie auch die restlichen Agenten eines Multiagenten-Systems, besitzen dabei nur
ein eingeschränktes, vages und zum Teil fehlerhaftes Wissen über die anderen
Agenten. Das Schema beschreibt, wie jeder Agent sein Wissen erlernen und davon ausgehend potentielle Holonenstrukturen simulationsbasiert aufbauen kann.
Anschlieÿend werden diese hypothetischen Holonenstrukturen in Verhandlungen
realisiert. Zur Umsetzung des Schemas und der daraus resultierenden Algorithmen wird ein mathematischer Formalismus zur Abbildung eines Multiagenten-
Systems auf einen Vektorraum vorgestellt, der es ermöglicht, die Entitäten des
Multiagenten-Systems und die Funktionen des Schemas formal zu beschreiben.
Aufbauend auf diesen Arbeiten und des Schemas werden abschlieÿend vier Algorithmen, von einem einfachen randomisierten Verfahren bis hin zu komplexen wissensbasierten Verfahren zur Holonenformierung, exemplarisch entwickelt,
diskutiert und evaluiert.This work proposes a scheme for the formation of holonic agents in a multiagentsystem acting in a dynamic environment. This model captures cooperative holonic multiagent-systems in which each agent has incomplete, vague and erroneous information about the other agents and about its dynamic and uncertain world. Holons are temporarily formed to fulfill complex tasks, that a single agent cannot handle alone. To find assistance the head of a holon continuously tries to improve its holonic structure. Therefore it builds a set of hypothetical holons, rating them and if a higher ranked holon structure than the current one is found, it starts with the (re-)negotiation of the holon. Also if the holon is for some reason not longer capable to achieve its goals, re-negotiation starts. The scheme describes in particular, how an agent learns the properties of other agents. Based on this knowledge the agents are then able to build hypothetical holons by simulations. In the following these hypothetical holons are realised by bilateral negotiations with the agents of that pre-computed holonstructure. For describing this scheme and the algorithms based on this scheme, I first present a formalism to map a multiagent-system onto a vector space, such that it is possible to give a formal description of the entities of a multiagenten-system and of the functions of the proposed scheme. Finally present four algorithms to form dynamically holons based on that scheme. These algorithms consist of a simple randomised agent selection to a complex knowledge-based selection of relevant agents to solve the given tasks. These algorithms are in the end discussed and evaluated in detail
The impact of the pre-treatment interval on antimicrobial efficacy in a biological model
The impact of pre-treatment intervals on the antipseudomonal efficacy of gentamicin, ticarcillin and ceftazidime was studied in an experimental thigh infection model in normal and granulocytopenic mice. Human-equivalent doses were used for simulating human pharmacokinetic profiles of the two study β-lactam drugs. A lethal inoculum of a virulent strain of Pseudomonas aeruginosa was injected into the thigh muscle. Treatment was started at various post-infection intervals. Antimicrobial efficacy was assessed by determinations of surviving organisms at the site of infection, and plasma drug concentrations were determined in the same mice. The age of infection had a substantial impact on antipseudomonal efficacy of the three study drugs even though high, brief supra-MIC concentrations of gentamicin and persistent supra-MIC concentrations of the β-lactam drugs were obtained. A pre-treatment interval of six or more hours abolished the bactericidal effect of all three study drugs despite accumulation of the drugs to multiple-MBC plasma concentrations. We believe that the impact of pre-treatment intervals on antimicrobial efficacy is of paramount importance for the interpretation of antimicrobial activity studies in experimental models of infection, although the mechanisms remain to be elucidate
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