2,083 research outputs found

    Multivariate functional and structural relationships.

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    Turbofan noise generation. Volume 1: Analysis

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    Computer programs were developed which calculate the in-duct acoustic modes excited by a fan/stator stae operating at subsonic tip speed. Three noise source mechanisms are included: (1) sound generated by the rotor blades interacting with turbulence ingested into, or generated within, the inlet duct; (2) sound generated by the stator vanes interacting with the turbulent wakes of the rotors blades; and (3) sound generated by the stator vanes interacting with the mean velocity deficit wakes of the rotor blades. The fan/stator stage is modeled as an ensemble of blades and vanes of zero camber and thickness enclosed within an infinite hard-walled annular duct. Turbulence drawn into or generated within the inlet duct is modeled as nonhomogeneous and anisotropic random fluid motion, superimposed upon a uniform axial mean flow, and convected with that flow. Equations for the duct mode amplitudes, or expected values of the amplitudes, are derived

    Turbofan noise generation. Volume 2: Computer programs

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    The use of a package of computer programs developed to calculate the in duct acoustic mods excited by a fan/stator stage operating at subsonic tip speed is described. The following three noise source mechanisms are included: (1) sound generated by the rotor blades interacting with turbulence ingested into, or generated within, the inlet duct; (2) sound generated by the stator vanes interacting with the turbulent wakes of the rotor blades; and (3) sound generated by the stator vanes interacting with the velocity deficits in the mean wakes of the rotor blades. The computations for three different noise mechanisms are coded as three separate computer program packages. The computer codes are described by means of block diagrams, tables of data and variables, and example program executions; FORTRAN listings are included

    Control of E. coli and Salmonella in growing-finishing pigs through the use of potassium diformate (KDF) – European case studies

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    Control of pathogenic bacteria has a high priority in European pork production. They can be a significant cause of zoonotic diseases and cause major economic losses in the pork production chain, through reduced productivity, increased veterinary and hygiene control costs. Preventing the spread of E. coli and Salmonella to the consumer requires special control measures during slaughter and processing. The extra cost of these controls is increasingly being transferred back to the producer in the form of financial penalties or the loss of the market for contaminated pigs. Improving gut health has been shown to be effective against intestinal pathogens, a strategy that has only really been made possible through the removal of antibiotic growth promoters in feed. Creating and maintaining a healthy intestinal environment has become essential to productivity and food safety programmes alike

    Prevalence and awareness of type 2 diabetes mellitus among adult population in Mwanza city, Tanzania

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    Type 2 diabetes mellitus (T2DM) prevalence is increasing rapidly around the world. This cross-sectional study was conducted to assess the prevalence and awareness of type 2 diabetes mellitus in Mwanza city, Tanzania. A multistage random sampling technique was used to obtain representative subjects. Information about causes and risk factors were collected using structured questionnaire. In addition, community random blood glucose testing was employed to identify those at risk. Subjects with ≥200mg/dl on the following day were subjected to fasting blood glucose testing and they were confirmed to have T2DM if they had blood glucose level of ≥126mg/dl. In each subject, height, weight, waist and hip circumferences and total fat and fat free mass were measured using standard procedures. A total of 640 participants were included in this study, 55% were females and 45% were males. Mean age of the respondent was 43.84 ± 10.80 years. Most (46.4%) respondents were in the age group 30-40 years. Mean age for females was 44.0 ± 10.31 years while for males was 43.6 ± 11.3 years (Table 1). Overall prevalence of T2DM was 11.9%, (n=76). Prevalence was high in females (7.2%; n=46) than in males (4.7%; n=30). The age between 41-50 years had the highest prevalence of T2DM 28.6% followed by 51-60 years age group (17.2%). Significant independent associations were found for age (OR 3.88, 95% CI: 2.16-6.95) positive first degree relative with T2DM (OR 1.34; 95%C: 1.10-1.64) alcohol intake (OR 1.23; 95%CI: 1.02-1.48,) smoking (OR 3.86; 95%CI: 2.57-5.78) and hypertension (OR 0.096; 95%CI: 1.954-18.251). Only 49.2 (n=315) of the respondents knew about the causes and symptoms of T2DM. Public education on T2DM should be emphasized and routine measurement of blood glucose levels is recommended among adults

    "Defences" bei Kriegsverbrechen am Beispiel Deutschlands und der USA : zugleich ein Beitrag zu einem Allgemeinen Teil des Völkerstrafrechts

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    Durch die Ereignisse im ehemaligen Jugoslawien und in Ruanda hat die völkerstrafrechtliche Diskussion einen neuen politischen Schub erfahren. Während ein Internationaler Strafgerichtshof mittlerweile errichtet wurde - wenn auch bislang nur mit einer Ad-hoc-Strafgerichtsbarkeit - ist die Entwicklung materiellrechtlicher Regeln des Völkerstrafrechts nicht mit entsprechender Dringlichkeit vorangetrieben worden. So dokumentieren die jüngst verabschiedeten Entwürfe der International Law Commission, einem Nebenorgan der UNO, daß insbesondere die Diskussion über einen Allgemeinen Teil eines Völkerstrafgesetzbuchs bislang eher vernachlässigt wurde. Die hier vorgelegte Arbeit zeigt die Problematik eines Völkerstrafgesetzes auf und leistet einen Beitrag zu dessen Allgemeinem Teil, indem einzelne Strafausschließungsgründe analysiert werden. Die Autorin untersucht zunächst die bereits bekannten defences auf ihre völkerrechtliche Anerkennung hin, um dann deren Voraussetzungen, Struktur und dogmatische Einordnung herauszuarbeiten. Im Mittelpunkt der Analyse stehen das Handeln auf Befehl, die Notstandsfrage und die Repressalie. Bezüglich der übrigen defences begnügt sich die Arbeit mit einer Problemanalyse. In der gegenwärtigen völkerstrafrechtlichen Diskussion bietet die Untersuchung wertvolle Ansätze für die Reform

    Body Size, Rather Than Male Eye Allometry, Explains Chrysomya megacephala (Diptera: Calliphoridae) Activity in Low Light

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    Male Chrysomya megacephala (F.) blow fly compound eyes contain an unusual area of enlarged dorsal facets believed to allow for increased light capture. This region is absent in females and has been hypothesized to aid in mate tracking in low light conditions or at greater distances. Many traits used in the attraction and capture of mates are allometric, growing at different rates relative to body size. Previous reports concerning C. megacephala eye properties did not include measurements of body size, making the relationship between the specialized eye region and body size unclear. We examined different morphological features of the eye among individuals of varying sizes. We found total eye size scaled proportionately to body size, but the number of enlarged dorsal facets increased as body size increased. This demonstrated that larger males have an eye that is morphologically different than smaller males. On the basis of external morphology, we hypothesized that since larger males have larger and a greater number of dorsally enlarged facets, and these facets are believed to allow for increased light capture, larger males would be active in lower light levels than smaller males and females of equal size. In a laboratory setting, larger males were observed to become active earlier in the morning than smaller males, although they did not remain active later in the evening. However, females followed the same pattern at similar light levels suggesting that overall body size rather than specialized male eye morphology is responsible for increased activity under low light conditions

    Theta Motion Processing in Fruit Flies

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    The tiny brains of insects presumably impose significant computational limitations on algorithms controlling their behavior. Nevertheless, they perform fast and sophisticated visual maneuvers. This includes tracking features composed of second-order motion, in which the feature is defined by higher-order image statistics, but not simple correlations in luminance. Flies can track the true direction of even theta motions, in which the first-order (luminance) motion is directed opposite the second-order moving feature. We exploited this paradoxical feature tracking response to dissect the particular image properties that flies use to track moving objects. We find that theta motion detection is not simply a result of steering toward any spatially restricted flicker. Rather, our results show that fly high-order feature tracking responses can be broken down into positional and velocity components – in other words, the responses can be modeled as a superposition of two independent steering efforts. We isolate these elements to show that each has differing influence on phase and amplitude of steering responses, and together they explain the time course of second-order motion tracking responses during flight. These observations are relevant to natural scenes, where moving features can be much more complex
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