1,050 research outputs found
Immunosympathectomy and avoidance behaviour in mice
W. B. Cannon and his co-workers during the 1930's had purported to have demonstrated the non-essential character of the sympathetic nervous system's role in mediating emotion, but later workers using behavioural studies have tended to implicate the system in emotional behaviour. In this thesis an immunological technique was used to induce hypotrophic growth in the sympathetic nervous system of neonatal rodents. The injection technique used a split- litter design with the control neonates being injected with normal horse serum (NHS) .Following failure to obtain behavioural separation between the immunosympathectomized (IS) and the control (NHS) litter- mates using standard active and passive avoidance tasks it was argued that the time course of these procedures allowed ample opportunity for internal compensatory mechanisms to mask any essential differences. Accordingly an avoidance task (startle response) with a very short time course was used to test the animals. This task also failed to show unequivocal behavioural separation. Measuring the catecholamine metabolism of the adrenals some evidence was obtained which showed that IS mice metabolized larger amounts of the sympathetic nervous system's transmitter substance, noradrenaline, when subjected to a novel or an avoidance task. Evidence was examined on the essential interaction between the sympatho-adrenal medulla and the pituitary-adrenal cortex axis. It was concluded that certain controls are essential if an unambiguous demonstration is to be made of these two important central nervous system's efferent outflows in emotional states. IS mice were placed on free operant avoidance schedules in specially constructed apparatus. The final experiment reported concerns an attempt to further reduce the range of IS mice adaptive responses by the use of an inclined alleyway avoidance task interpolated between two equal periods of free operant avoidance responding. It was finally concluded that unequivocal behavioural separation, using avoidance tasks, has not been shown between IS and control litterraate mice either in this thesis or other published work. Hypotheses are discussed as to why this should be so
Influence of fuselage on propeller design
In the present paper I shall not consider the problem of the best arrangement of airplane and propeller, but only a simple method for designing a propeller for a given arrangement of airplane parts. The inflow to the propeller and hence the efficiency of the propeller is affected most by the fuselage
Pressure-distribution measurements on a tapered wing with a partial-span split flap in curved flight
Pressure-distribution tests were made on the 32-foot whirling arm of the Daniel Guggenheim Airship Institute of a tapered wing to determine the rolling and the yawing moments due to an angular velocity in yaw. The model was tested at 0 degree and 5 degree pitch; 0 degree, 5 degree, and 10 degree yaw; and with split flaps covering 25, 50, 75, and 100 percent of the wing span and deflected 60 degrees. The results are given in the form of load distributions and as calculated moment coefficients. The experimental values of rolling- and yawing- moment coefficients were in fairly close agreement with theory
Pressure-distribution Measurements on a Tapered Wing with a Full-span Split Flap in Curved Flight
Pressure-distribution tests were made on the 32-foot whirling arm of the Daniel Guggenheim Airship Institute of a tapered wing to determine the rolling and yawing moments due to an angular velocity in yaw. The model was tested at 0 degree and 5 degrees pitch, -1 degree and 5 degree yaw, and with a full-span flap deflected 60 degrees. The results are given in the form of span load distributions and in calculated moment coefficients. The rolling-moment coefficients are in fairly close agreement with those derived by means of a simple approximate theory even for high deflection of the full-span flap
Physiologic Cold Shock Increases Adherence of Moraxella catarrhalis to and Secretion of Interleukin 8 in Human Upper Respiratory Tract Epithelial Cells
Moraxella catarrhalis, a major nasopharyngeal pathogen of the human respiratory tract, is exposed to rapid and prolonged downshifts of environmental temperature when humans breathe cold air. In the present study, we show that a 26°C cold shock up-regulates the expression of UspA1, a major adhesin and putative virulence factor of M. catarrhalis, by prolonging messenger RNA half-life. Cold shock promotes M. catarrhalis adherence to upper respiratory tract cells via enhanced binding to fibronectin, an extracellular matrix component that mediates bacterial attachment. Exposure of M. catarrhalis to 26°C increases the outer membrane protein-mediated release of the proinflammatory cytokine interleukin 8 in pharyngeal epithelial cells. Furthermore, cold shock at 26°C enhances the binding of salivary immunoglobulin A on the surface of M. catarrhalis. These data indicate that cold shock at a physiologically relevant temperature of 26°C affects the nasopharyngeal host-pathogen interaction and may contribute to M. catarrhalis virulenc
Down-regulation of porin M35 in Moraxella catarrhalis by aminopenicillins and environmental factors and its potential contribution to the mechanism of resistance to aminopenicillins
Objectives The outer membrane protein M35 of Moraxella catarrhalis is an antigenically conserved porin. Knocking out M35 significantly increases the MICs of aminopenicillins. The aim of this study was to determine the biological mechanism of this potentially new antimicrobial resistance mechanism of M. catarrhalis and the behaviour of M35 in general stress situations. Methods PCR using m35-specific primers was used to detect the m35 gene in clinical isolates. The m35 mRNA expression of strains 300, O35E and 415 after exposure to amoxicillin and different stress conditions was measured by real-time PCR and normalized in relation to their 16S rRNA expression. The expression of M35 protein was analysed by SDS-PAGE and western blotting. Results Screening of 52 middle ear isolates resulted in positive PCR products for all tested strains. The analysis of m35 mRNA expression after amoxicillin treatment showed 24%-85% down-regulation compared with the respective amoxicillin-free controls in all three strains tested. Also, analysis of protein concentrations revealed lower M35 expression after growth with amoxicillin. Investigation of M35 during general stress responses showed down-regulation of the porin with growth at 26°C and 42°C, under hyperosmolar stress and under iron restriction. Conclusions The reduced expression of M35 after aminopenicillin exposure indicates a novel resistance mechanism against aminopenicillins in M. catarrhalis, which may be relevant in vivo. The differences in expression after different stress treatments demonstrate that M35 is involved in general stress response
Determination of the spatial and temporal variation of tropospheric water vapour using CGPS networks
Tropospheric water vapour is the main limiting factor in using GPS to determine crustal deformation at highest accuracy. On the other hand, it is an important variable to monitor meteorological and climatic processes. This paper discusses both aspects: the modelling of tropospheric water vapour using meteorological data as well as the determination of the integrated amount of water vapour and its spatiotemporal variation using GPS data. Switzerland has been chosen as experiment area. The Swiss continuous GPS (CGPS) network AGNES is used as a reference network, which represents a realistic scenario for GPS-based water vapour determination. Data of the Swiss numerical weather model aLMo are used for systematic comparison and validation. For the first aspect, integrated tropospheric wet refractivity values are determined from meteorological measurements and compared with GPS path delays. An overall agreement of 1 cm of zenith wet path delay was achieved. For the second aspect a tomographic approach has been developed. A total of 6720 GPS-determined profiles are compared with data of the numerical weather model and radio soundings. The results are statistically evaluated and systematically compared with each other. A correlation between the accuracy and the weather situation was found. Overall, an agreement of 5-7 ppm (refractivity unit) was obtained compared to aLMo. The use of GPS-determined path delays from a permanent GPS network is the recommended method to correct GPS measurements. In all other cases, the two methods presented (COITROPA, COMEDIE) are a feasible alternative to determine path delays accurately. Furthermore, GPS is a convenient application to determine the amount of water vapour in the troposphere. It is demonstrated that the vertical distribution of water vapour can be deduced by applying the tomographic approac
Mycobacterium bovis detection in slaughtered pigs in the state of Rio Grande do Sul, Brazil
The infection by the Mycobacterium genus is important in pig farming due to the economic losses caused by total or partial carcass condemnation in slaughterhouses. The present study investigated the occurrence of a tuberculosis outbreak in pigs, based on the identification of lesions at the slaughter line of a slaughterhouse. At the inspection line of the slaughterhouse, carcasses were identified with viscera containing macroscopic lesions that indicated tuberculosis (granulomatous lymphadenitis). Tracheobronchial, mesenteric, and submandibular lymph nodes were collected, as well as liver samples and their corresponding lymph nodes. The samples were sent to the Federal Agricultural Defense Laboratory (LFDA/RS) and processed for the diagnosis of tuberculosis and the molecular characterization of Mycobacterium bovis. Based on the results of post-mortem and laboratory inspections, the occurrence was characterized as a tuberculosis outbreak in pigs, which originated from a farm in the state of Rio Grande do Sul, Brazil. Over three months, three batches, adding up to 2884 animals, were sent to slaughter, of which 102 (3.5%) had tuberculosis-like lesions at the inspection line. Based on these results, the productive process was investigated, assessing the feeding, water supply, and milk whey offered in the diet of pigs. It was concluded that the outbreak was caused by feeding unpasteurized or inadequately pasteurized (insufficient time x temperature relation) whey to the pigs. The use of whey from cheese production is a frequent practice in the state of Rio Grande do Sul and one of the risk factors for granulomatous lymphadenitis in pigs
Physiologic cold shock of Moraxella catarrhalis affects the expression of genes involved in the iron acquisition, serum resistance and immune evasion
<p>Abstract</p> <p>Background</p> <p><it>Moraxella catarrhalis</it>, a major nasopharyngeal pathogen of the human respiratory tract, is exposed to rapid downshifts of environmental temperature when humans breathe cold air. It was previously shown that the prevalence of pharyngeal colonization and respiratory tract infections caused by <it>M. catarrhalis </it>are greatest in winter. The aim of this study was to investigate how <it>M. catarrhalis </it>uses the physiologic exposure to cold air to upregulate pivotal survival systems in the pharynx that may contribute to <it>M. catarrhalis </it>virulence.</p> <p>Results</p> <p>A 26°C cold shock induces the expression of genes involved in transferrin and lactoferrin acquisition, and enhances binding of these proteins on the surface of <it>M. catarrhalis</it>. Exposure of <it>M. catarrhalis </it>to 26°C upregulates the expression of UspA2, a major outer membrane protein involved in serum resistance, leading to improved binding of vitronectin which neutralizes the lethal effect of human complement. In contrast, cold shock decreases the expression of Hemagglutinin, a major adhesin, which mediates B cell response, and reduces immunoglobulin D-binding on the surface of <it>M. catarrhalis</it>.</p> <p>Conclusion</p> <p>Cold shock of <it>M. catarrhalis </it>induces the expression of genes involved in iron acquisition, serum resistance and immune evasion. Thus, cold shock at a physiologically relevant temperature of 26°C induces in <it>M. catarrhalis </it>a complex of adaptive mechanisms that enables the bacterium to target their host cellular receptors or soluble effectors and may contribute to enhanced growth, colonization and virulence.</p
Project Risk Management
Tato bakalářská práce se zabývá řízením rizik projektu. V první části teoretického bloku se čtenář seznámí se základními prvky projektového managementu, jako jsou cíle projektu a plánování projektu. V druhé části teoretického bloku jsou popsány základy řízení rizik v projektu. Blok věnovaný praktické části popisuje společnost Hospimed, spol. s r.o. a projekt "ZŠ Fr. Plamínkové Rekonstrukce kuchyňského provozu, ul. Fr. Křižíka 490/2". Hlavním cílem práce je identifikace, ohodnocení a návrh ošetření rizik tohoto projektu. Výstupem práce je registr rizik projektu doplněný o návrh na zefektivnění řízení rizik. Společnosti Hospimed, spol. s r.o. je doporučeno využít tuto bakalářskou práci jako podklad ke zlepšení řízení rizik u budoucích projektů.ObhájenoThis bachelor thesis deals with project risk management. In the first part of the theoretical block, the reader is introduced to the basic elements of project management, such as project objectives and project planning. The second part of the theoretical block describes the basics of risk management in a project. The case study describes Hospimed, spol. s r.o. and the project "ZŠ Fr. Plamínkové Rekonstrukce kuchyňského provozu, ul. Fr. Křižíka 490/2 ". The main aim of the work is to identify, evaluate and suggest a suitable reaction on risks of this project. The outcome of this thesis is the risk register of the project supplemented by a proposal for improving the risk management. This bachelor thesis is recommended to be used as a basis for improving the risk management of future projects at the Hospimed, spol. s r.o
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