837 resultados para Rate
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Lobjectif de la prsente tude tait dvaluer un test destrase leucocytaire (LE) pour le diagnostic de lendomtrite subclinique chez les vaches Holstein en priode postpartum. Les tests effectus partir dchantillons provenant soit de lendomtre (UtLE) ou du col utrin (CxLE) ont t compars la cytologie endomtriale (CE). Par ailleurs, deux mthodes dvaluation des lames ont t compares. Deux cent quatre vingt-cinq vaches Holstein de 5 troupeaux laitiers commerciaux ont t values entre 21 et 47 jours en lait (JEL). Soixante sept vaches ont t diagnostiques avec une endomtrite clinique suite un examen transrectal et vaginoscopique et ont t exclues de ltude. Deux cent dix-huit vaches ont eu des prlvements pour la CE et le test LE. La fonction ovarienne a t dtermine la palpation transrectale. La banque de donnes utilise pour chacune des vaches a t effectue partir du logiciel DSA (Dossier de Sant Animale) laitier. Le pourcentage de neutrophiles tait significativement corrl avec les scores de LE utrin et cervical. Lactivit de CxLE et UtLE diminuait significativement avec les JEL, mais ntait pas associe au risque de gestation 90 JEL (n= 186). Le pourcentage de neutrophiles mesur la CE entre 32 et 47 JEL tait associ significativement au risque de gestation 90 JEL (n=94, P=0.04). Pour la mme priode, selon une analyse de survie, les vaches avec >2,6% de neutrophiles la CE taient dfinies comme tant atteintes dune endomtrite subclinique avec une prvalence de 56%. Les rsultats indiquent que le test destrase utrin ou cervical a une bonne concordance avec le pourcentage de neutrophiles la CE. Une endomtrite subclinique diagnostique par cytologie endometriale entre 32 et 47 JEL est associe une rduction du risque de gestation au premier service.
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La grossesse induit de profonds changements hmodynamiques et mtaboliques de lorganisme maternel qui ont des consquences sur le cur. Ladaptation du cur cette condition physiologique ncessite un remodelage de sa structure et par consquent des ajustements de sa fonction. Les mcanismes responsables de ces adaptations sont en grande partie inconnus. Cependant, ces connaissances sont essentielles pour la comprhension des complications cardiovasculaires, telle que lhypertension gestationnelle (HG), qui constituent un risque pour la sant de la mre et du ftus. Afin de caractriser les adaptations du cur lors de la grossesse, loriginalit de notre approche exprimentale consistait tudier le remodelage lchelle des cardiomyocytes du ventricule gauche. Ainsi, notre premier objectif tait de dterminer les modifications structurales et fonctionnelles des cardiomyocytes chez la rate en vue didentifier les altrations lors de lHG. Chez les rates gestantes, le remodelage structural des cardiomyocytes se caractrise par une hypertrophie cellulaire avec une augmentation proportionnelle des dimensions. LHG a t induite par un supplment sodique (0.9% NaCl) dans la dite. Linadaptation structurale lors de lHG se traduit par une diminution du volume cellulaire. Ltude des modifications fonctionnelles a rvl que lors de la gestation le fonctionnement contractile des cellules est dpendant de ladaptation du mtabolisme maternel. En effet, les substrats nergtiques, lactate et pyruvate, induisent une augmentation de la contractilit des cardiomyocytes. Cet effet est plus faible dans les cellules des rates hypertendues, ce qui suggre des anomalies du couplage excitation-contraction, dans lequel les courants calciques de type L (ICa-L) jouent un rle important. Paradoxalement, le lactate et le pyruvate ont induit une augmentation de la densit des courants ICa-L seulement chez les rates hypertendues. Le rcepteur aux minralocorticodes (RM) est connu pour son implication dans le remodelage structuro-fonctionnel du cur dans les conditions pathologiques mais pas dans celui induit par la grossesse. Notre deuxime objectif tait donc de dterminer le rle du RM dans ladaptation de la morphologie et de la contractilit des cardiomyocytes. Des rates gestantes ont t traites avec le canrnoate de potassium (20 mg/kg/jr), un antagoniste des RM. Linhibition des RM pendant la gestation empche lhypertrophie cellulaire. De plus, linhibition des RM bloque leffet du lactate et du pyruvate sur la contractilit. Chez la femme, la grossesse est associe des changements des proprits lectriques du cur. Sur llectrocardiogramme, lintervalle QTc est plus long, tmoignant de la prolongation de la repolarisation. Les mcanismes rgulant cette adaptation restent encore inconnus. Ainsi, notre troisime objectif tait de dterminer le rle du RM dans ladaptation de la repolarisation. Chez la rate gestante, lintervalle QTc est prolong ce qui est corrobor par la diminution des courants potassiques Ito et IK1. Linhibition des RM pendant la gestation empche la prolongation de lintervalle QTc et la diminution des courants Ito. Les travaux exposs dans cette thse apportent une vision plus prcise du remodelage cardiaque induit par la grossesse, qui est permise par ltude lchelle cellulaire. Nos rsultats montrent que lors de la gestation et de lHG les cardiomyocytes subissent des remodelages morphologiques contrasts. Notre tude a aussi rvl que lors de la gestation, la fonction contractile est tributaire des adaptations mtaboliques et que cette relation est altre lors de lHG. Nos travaux montrent que la rgulation de ces adaptations gestationnelles fait intervenir le RM au niveau de la morphologie, de la relation mtabolisme/fonctionnement contractile et de la repolarisation. En faisant avancer les connaissances sur lhypertrophie de la grossesse, ces travaux vont permettre damliorer la comprhension des complications cardiovasculaires gestationnelles.
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Mmoire numris par la Division de la gestion de documents et des archives de l'Universit de Montral
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Les causes de la crise irakienne actuelle sont multiples. Au-del des implications immdiates, les squelles de lintervention militaire de 2003 sont les plus dterminantes. Lchec du processus de reconstruction institutionnelle a donn lieu un tat dficient, dysfonctionnel et corrompu offrant ainsi un terreau fertile limplantation et la prolifration des mouvements terroristes et mafieux. Lauteur tente, dans la prsente contribution, didentifier les raisons profondes du drame actuel en tenant compte de limpact des bouleversements intervenus depuis la chute du rgime baathiste en avril 2003 sur les structures tatiques.
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Selected grades of low density polyethylene (LDPE) polystyrene (PS) were extruded in a laboratory extruder by varying the feeding rate at different revolutions per minute and temperatures. The mechanical properties of the extruded plastic sheets were determined. LDPE shows a marked variation in mechanical properties with feeding rate while PS shows a marginal change in mechanical properties with feeding rate. However, for both plastics there is a particular feeding rate in the starved region which results in maximum mechanical properties.
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Filled and gum compounds of Isobutylene-Isoprene rubber were extruded through a laboratory extruder at various feeding rates, different temperatures and revolutions per minute. The extruded compounds were vulcanized up to their optimum cure times and the mechanical properties of the vulcanizates were determined. The properties suggest that there is a particular feeding rate in the starved fed region, which results in maximum mechanical properties. The study shows that running the extruder at a slightly starved condition is an attractive means of improving the physical properties.
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A novel sensing technique for the in situ monitoring of the rate of pulsed laser deposition (PLD) of metal thin films has been developed. This optical fibre based sensor works on the principle of the evanescent wave penetration of waveguide modes into the uncladded portion of a multimode fibre. The utility of this optical fibre sensor is demonstrated in the case of PLD of silver thin films obtained by a Q-switched Nd:YAG laser which is used to irradiate a silver target at the required conditions for the preparation of thin films. This paper describes the performance and characteristics of the sensor and shows how the device can be used as an effective tool for the monitoring of the deposition rate of silver thin films. The fibre optic sensor is very simple, inexpensive and highly sensitive compared with existing techniques for thin film deposition rate measurements
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A novel sensing technique for the in situ monitoring of the rate of pulsed laser deposition (PLD) of metal thin films has been developed. This optical fibre based sensor works on the principle of the evanescent wave penetration of waveguide modes into the uncladded portion of a multimode fibre. The utility of this optical fibre sensor is demonstrated in the case of PLD of silver thin films obtained by a Q-switched Nd:YAG laser which is used to irradiate a silver target at the required conditions for the preparation of thin films. This paper describes the performance and characteristics of the sensor and shows how the device can be used as an effective tool for the monitoring of the deposition rate of silver thin films. The fibre optic sensor is very simple, inexpensive and highly sensitive compared with existing techniques for thin film deposition rate measurements.
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A novel fibre optic sensor for the in situ measurement of the rate of deposition of thin films has been developed. Evanescent wave in the uncladded portion of a multimode fibre is utilised for this sensor development. In the present paper we demonstrate how this sensor is useful for the monitoring of the deposition rate of polypyrrole thin films, deposited by an AC plasma polymerisation method. This technique is simple, accurate and highly sensitive compared with existing techniques.
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The design and development of an evanescent wave sensor to determine the etching rate of the core of an optical fibre is discussed in this paper. The working of the device is based on the principle of propagation and loss of the evanescent wave in the cladding region of the fibre. The fraction of light intensity creeping out of the core of an uncladded fibre is a function of the core radius. As this radius decreases, the evanescent wave coupling to the medium surrounding the core enhances. This results in a decrease of the transmitted light intensity through the fibre. This technique is useful to design and fabricate optical fibres with different core geometries.
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We investigate chaotic, memory, and cooling rate effects in the three-dimensional Edwards-Anderson model by doing thermoremanent (TRM) and ac susceptibility numerical experiments and making a detailed comparison with laboratory experiments on spin glasses. In contrast to the experiments, the Edwards-Anderson model does not show any trace of reinitialization processes in temperature change experiments (TRM or ac). A detailed comparison with ac relaxation experiments in the presence of dc magnetic field or coupling distribution perturbations reveals that the absence of chaotic effects in the Edwards-Anderson model is a consequence of the presence of strong cooling rate effects. We discuss possible solutions to this discrepancy, in particular the smallness of the time scales reached in numerical experiments, but we also question the validity of the Edwards-Anderson model to reproduce the experimental results.
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The present study is focused on the intensity distribution of rainfall in different classes and their contribution to the total seasonal rainfall. In addition, we studied the spatial and diurnal variation of the rainfall in the study areas. For the present study, we retrieved data from TRMM (Tropical Rain Measuring Mission) rain rate available in every 3 h temporal and 25 km spatial resolutions. Moreover, station rainfall data is used to validate the TRMM rain rate and found significant correlation between them (linear correlation coefficients are 0.96, 0.85, 0.75 and 0.63 for the stations Kota Bharu, Senai, Cameron highlands and KLIA, respectively). We selected four areas in the Peninsular Malaysia and they are south coastal, east coastal, west coastal and highland regions. Diurnal variation of frequency of rain occurrence is different for different locations. We noticed bimodal variation in the coastal areas in most of the seasons and unimodal variation in the highland/inland area. During the southwest monsoon period in the west coastal stations, there is no distinct diurnal variation. The distribution of different intensity classes during different seasons are explained in detail in the results
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Starve feeding of single screw extruder was described as an important means of improving the performance characteristics of the extruder. In addition to such improvement with versatility, the starve feeding technique also may affect the mechanical properties of the extrudate since the heat transfer an(l mixing characteristics in the starve fed and Hood fed extruders are not the same. Since the material is more loosely packed in the channels of the starve fed extruder, there may be greater bed mobility and uniformity. Further, the. thermal an(l shear induced degradation are also less since possibilities of developing local high temperatures are less compared to a densely compacted extruder bed. This study has been undertaken mainly to explore the effect of feeding rate on the mechanical properties of rubber and plastic extrudates since the effect of feeding rate has not been analysed from this angle so far.
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Coded OFDM is a transmission technique that is used in many practical communication systems. In a coded OFDM system, source data are coded, interleaved and multiplexed for transmission over many frequency sub-channels. In a conventional coded OFDM system, the transmission power of each subcarrier is the same regardless of the channel condition. However, some subcarrier can suffer deep fading with multi-paths and the power allocated to the faded subcarrier is likely to be wasted. In this paper, we compute the FER and BER bounds of a coded OFDM system given as convex functions for a given channel coder, inter-leaver and channel response. The power optimization is shown to be a convex optimization problem that can be solved numerically with great efficiency. With the proposed power optimization scheme, near-optimum power allocation for a given coded OFDM system and channel response to minimize FER or BER under a constant transmission power constraint is obtained
