997 resultados para (modified) reflection equation algebra
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Esta investigación se realizó para determinar el crecimiento de Platyxanthus orbignyi “cangrejo violáceo” capturados en la caleta de Huanchaco, ubicado en el distrito de Huanchaco, Provincia de Trujillo, Departamento La Libertad, durante el 2015. El objetivo fue determinar el crecimiento de P. orbignyi, la muestra estuvo constituida por 1477 ejemplares procedentes de las capturas que realizan los pescadores artesanales empleando caballitos de totora y trampas denominadas nasas. Estos muestreos fueron mensuales durante el año 2015. La relación entre longitud cefalotorácica (mm) y ancho cefalotorácico (mm) presentó diferencia estadística entre las líneas de regresión de ambos sexos, la relación entre el ancho cefalotorácico (mm) y peso total (g) mostró alometría en el crecimiento de hembras y machos, estadísticamente no se encontró diferencia entre los sexos. Mediante el método de Bhattacharya (1967) modificado por Pauly y Caddy (1985) se establecieron siete estados de muda para las hembras y nueve estados de muda para los machos. Según el criterio de Kurata (1962) se estableció que el crecimiento en ambos sexos es de tipo geométrico retrogresivo. Los parámetros calculados se ajustaron a la ecuación de von Bertalanffy.
Resumo:
OBJECTIVE: To assess the suitability of a hot-wire anemometer infant monitoring system (Florian, Acutronic Medical Systems AG, Hirzel, Switzerland) for measuring flow and tidal volume (Vt) proximal to the endotracheal tube during high-frequency oscillatory ventilation. DESIGN: In vitro model study. SETTING: Respiratory research laboratory. SUBJECT: In vitro lung model simulating moderate to severe respiratory distress. INTERVENTION: The lung model was ventilated with a SensorMedics 3100A ventilator. Vt was recorded from the monitor display (Vt-disp) and compared with the gold standard (Vt-adiab), which was calculated using the adiabatic gas equation from pressure changes inside the model. MEASUREMENTS AND MAIN RESULTS: A range of Vt (1-10 mL), frequencies (5-15 Hz), pressure amplitudes (10-90 cm H2O), inspiratory times (30% to 50%), and Fio2 (0.21-1.0) was used. Accuracy was determined by using modified Bland-Altman plots (95% limits of agreement). An exponential decrease in Vt was observed with increasing oscillatory frequency. Mean DeltaVt-disp was 0.6 mL (limits of agreement, -1.0 to 2.1) with a linear frequency dependence. Mean DeltaVt-disp was -0.2 mL (limits of agreement, -0.5 to 0.1) with increasing pressure amplitude and -0.2 mL (limits of agreement, -0.3 to -0.1) with increasing inspiratory time. Humidity and heating did not affect error, whereas increasing Fio2 from 0.21 to 1.0 increased mean error by 6.3% (+/-2.5%). CONCLUSIONS: The Florian infant hot-wire flowmeter and monitoring system provides reliable measurements of Vt at the airway opening during high-frequency oscillatory ventilation when employed at frequencies of 8-13 Hz. The bedside application could improve monitoring of patients receiving high-frequency oscillatory ventilation, favor a better understanding of the physiologic consequences of different high-frequency oscillatory ventilation strategies, and therefore optimize treatment.
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Investigations of solute transport in fractured rock aquifers often rely on tracer test data acquired at a limited number of observation points. Such data do not, by themselves, allow detailed assessments of the spreading of the injected tracer plume. To better understand the transport behavior in a granitic aquifer, we combine tracer test data with single-hole ground-penetrating radar (GPR) reflection monitoring data. Five successful tracer tests were performed under various experimental conditions between two boreholes 6 m apart. For each experiment, saline tracer was injected into a previously identified packed-off transmissive fracture while repeatedly acquiring single-hole GPR reflection profiles together with electrical conductivity logs in the pumping borehole. By analyzing depth-migrated GPR difference images together with tracer breakthrough curves and associated simplified flow and transport modeling, we estimate (1) the number, the connectivity, and the geometry of fractures that contribute to tracer transport, (2) the velocity and the mass of tracer that was carried along each flow path, and (3) the effective transport parameters of the identified flow paths. We find a qualitative agreement when comparing the time evolution of GPR reflectivity strengths at strategic locations in the formation with those arising from simulated transport. The discrepancies are on the same order as those between observed and simulated breakthrough curves at the outflow locations. The rather subtle and repeatable GPR signals provide useful and complementary information to tracer test data acquired at the outflow locations and may help us to characterize transport phenomena in fractured rock aquifers.
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Tot seguit presentem un entorn per analitzar senyals de tot tipus amb LDB (Local Discriminant Bases) i MLDB (Modified Local Discriminant Bases). Aquest entorn utilitza funcions desenvolupades en el marc d’una tesi en fase de desenvolupament. Per entendre part d’aquestes funcions es requereix un nivell de coneixement avançat de processament de senyals. S’han extret dels treballs realitzats per Naoki Saito [3], que s’han agafat com a punt de partida per la realització de l’algorisme de la tesi doctoral no finalitzada de Jose Antonio Soria. Aquesta interfície desenvolupada accepta la incorporació de nous paquets i funcions. Hem deixat un menú preparat per integrar Sinus IV packet transform i Cosine IV packet transform, tot i que també podem incorporar-n’hi altres. L’aplicació consta de dues interfícies, un Assistent i una interfície principal. També hem creat una finestra per importar i exportar les variables desitjades a diferents entorns. Per fer aquesta aplicació s’han programat tots els elements de les finestres, en lloc d’utilitzar el GUIDE (Graphical User Interface Development Enviroment) de MATLAB, per tal que sigui compatible entre les diferents versions d’aquest programa. En total hem fet 73 funcions en la interfície principal (d’aquestes, 10 pertanyen a la finestra d’importar i exportar) i 23 en la de l’Assistent. En aquest treball només explicarem 6 funcions i les 3 de creació d’aquestes interfícies per no fer-lo excessivament extens. Les funcions que explicarem són les més importants, ja sigui perquè s’utilitzen sovint, perquè, segons la complexitat McCabe, són les més complicades o perquè són necessàries pel processament del senyal. Passem cada entrada de dades per part de l’usuari per funcions que ens detectaran errors en aquesta entrada, com eliminació de zeros o de caràcters que no siguin números, com comprovar que són enters o que estan dins dels límits màxims i mínims que li pertoquen.
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We consider the Clifford algebra C(q) of a regular quadratic space (V, q) over a field K with its structure of Z/2Z-graded K-algebra. We give a characterization of the group of graded automorphisms of C(q). In the last section we introduce the Z/nZ-graded algebras and we study as well as the group of graded automorphisms for some of them.
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This study aimed to evaluate the impact of genetically modified (GM) wheat with introduced pm3b mildew resistance transgene, on two types of root-colonizing microorganisms, namely pseudomonads and arbuscular mycorrhizal fungi (AMF). Our investigations were carried out in field trials over three field seasons and at two locations. Serial dilution in selective King's B medium and microscopy were used to assess the abundance of cultivable pseudomonads and AMF, respectively. We developed a denaturing gradient gel electrophoresis (DGGE) method to characterize the diversity of the pqqC gene, which is involved in Pseudomonas phosphate solubilization. A major result was that in the first field season Pseudomonas abundances and diversity on roots of GM pm3b lines, but also on non-GM sister lines were different from those of the parental lines and conventional wheat cultivars. This indicates a strong effect of the procedures by which these plants were created, as GM and sister lines were generated via tissue cultures and propagated in the greenhouse. Moreover, Pseudomonas population sizes and DGGE profiles varied considerably between individual GM lines with different genomic locations of the pm3b transgene. At individual time points, differences in Pseudomonas and AMF accumulation between GM and control lines were detected, but they were not consistent and much less pronounced than differences detected between young and old plants, different conventional wheat cultivars or at different locations and field seasons. Thus, we conclude that impacts of GM wheat on plant-beneficial root-colonizing microorganisms are minor and not of ecological importance. The cultivation-independent pqqC-DGGE approach proved to be a useful tool for monitoring the dynamics of Pseudomonas populations in a wheat field and even sensitive enough for detecting population responses to altered plant physiology.
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Contamination of weather radar echoes by anomalous propagation (anaprop) mechanisms remains a serious issue in quality control of radar precipitation estimates. Although significant progress has been made identifying clutter due to anaprop there is no unique method that solves the question of data reliability without removing genuine data. The work described here relates to the development of a software application that uses a numerical weather prediction (NWP) model to obtain the temperature, humidity and pressure fields to calculate the three dimensional structure of the atmospheric refractive index structure, from which a physically based prediction of the incidence of clutter can be made. This technique can be used in conjunction with existing methods for clutter removal by modifying parameters of detectors or filters according to the physical evidence for anomalous propagation conditions. The parabolic equation method (PEM) is a well established technique for solving the equations for beam propagation in a non-uniformly stratified atmosphere, but although intrinsically very efficient, is not sufficiently fast to be practicable for near real-time modelling of clutter over the entire area observed by a typical weather radar. We demonstrate a fast hybrid PEM technique that is capable of providing acceptable results in conjunction with a high-resolution terrain elevation model, using a standard desktop personal computer. We discuss the performance of the method and approaches for the improvement of the model profiles in the lowest levels of the troposphere.
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The right of a person to be protected from natural hazards is a characteristic of the social and economical development of the society. This paper is a contribution to the reflection about the role of Civil Protection organizations in a modern society. The paper is based in the inaugural conference made by the authors on the 9th Plinius Conference on Mediterranean Storms. Two major issues are considered. The first one is sociological; the Civil Protection organizations and the responsible administration of the land use planning should be perceived as reliable as possible, in order to get consensus on the restrictions they pose, temporary or definitely, on the individual free use of the territory as well as in the entire warning system. The second one is technological: in order to be reliable they have to issue timely alert and warning to the population at large, but such alarms should be as "true" as possible. With this aim, the paper summarizes the historical evolution of the risk assessment, starting from the original concept of "hazard", introducing the concepts of "scenario of event" and "scenario of risk" and ending with a discussion about the uncertainties and limits of the most advanced and efficient tools to predict, to forecast and to observe the ground effects affecting people and their properties. The discussion is centred in the case of heavy rains and flood events in the North-West of Mediterranean Region.
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Apart from therapeutic advances related to new treatments, our practices in the management of early breast cancer have been modified by to key organizational settings (1) mass screening, substantially altering the presentation and epidemiology of breast cancer and (2) the development of guidelines to ensure that any patient management is in agreement with the demonstrated impact in the adjuvant treatment. In daily practice, the impact of screening and guidelines recommendations has put us now in a paradoxical situation: while the majority of non-metastatic breast cancers treated in the hexagon are node negative, most of the results of clinical studies on chemotherapy and targeted therapies today arise from populations predominantly node positive. Therefore, it seemed legitimate to convene a working group around a reflection on the directions of adjuvant chemotherapy in a growing node negative population in order to better respond to the questions of the field oncologists, trying to address the discrepancies between different existing guidelines.
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Ammonia gas detection by pure and catalytically modified WO3 based gas sensor was analysed. The sensor response of pure WO3 to NH3 was not only rather low but also presented an abnormal behaviour, probably due to the unselective oxidation of ammonia to NOx. Copper and vanadium were introduced in different concentrations and the resulting material was annealed at different temperatures in order to improve the sensing properties for NH3 detection. The introduction of copper and vanadium as catalytic additives improved the response to NH3 and also eliminated the abnormal behaviour. Possible mechanisms of NH3 reaction over these materials are discussed. Sensor responses to other gases like NO2 or CO and the interference of humidity on ammonia detection were also analysed so as to choose the best sensing element.
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284 million people worldwide suffered from type 2 diabetes mellitus (T2DM) in 2010, which will, in approximately half of them, lead to the development of diabetic peripheral neuropathy (DPN). Although DPN is the most common complication of diabetes mellitus and the leading cause of non-traumatic amputations its pathophysiology is still poorly understood. To get more insight into the molecular mechanism underlying DPN in T2DM, I used a rodent model of T2DM, the db/db mice.¦ln vivo electrophysiological recordings of diabetic animals indicated that in addition to reduced nerve conduction velocity db/db mice also present increased nerve excitability. Further ex vivo evaluation of the electrophysiological properties of db/db nerves clearly established a presence of the peripheral nerve hyperexcitability (PNH) phenotype in diabetic animals. Using pharmacological inhibitors we demonstrated that PNH is mostly mediated by the decreased activity of Kv1 channels. ln agreement with these data 1 observed that the diabetic condition led to a reduced presence of the Kv1.2 subunits in juxtaparanodal regions of db/db peripheral nerves whereas its mANA and protein expression levels were not affected. Lmportantly, I confirmed a loss of juxtaparanodal Kv1.2 subunits in nerve biopsies from type 2 diabetic patients. Together these observations indicate that the type 2 diabetic condition leads to potassium-channel mediated changes of nerve excitability thus identifying them as potential drug targets to treat sorne of the DPN related symptoms.¦Schwann cells ensheath and isolate peripheral axons by the production of myelin, which consists of lipids and proteins in a ratio of 2:1. Peripheral myelin protein 2 (= P2, Pmp2 or FABP8) was originally described as one of the most abundant myelin proteins in the peripheral nervous system. P2, which is a member of the fatty acid binding protein (FABP) family, is a 14.8 kDa cytosolic protein expressed on the cytoplasmic side of compact myelin membranes. As indicated by their name, the principal role of FABPs is thought to be the binding and transport of fatty acids.¦To study its role in myelinating glial cells I have recently generated a complete P2 knockout mouse model (P2-/-). I confirmed the loss of P2 in the sciatic nerve of P2-/- mice at the mRNA and protein level. Electrophysiological analysis of the adult (P56) mutant mice revealed a mild but significant reduction in the motor nerve conduction velocity. lnterestingly, this functional change was not accompanied by any detectable alterations in general myelin structure. However, I have observed significant alterations in the mRNA expression level of other FABPs, predominantly FABP9, in the PNS of P2-/- mice as compared to age-matched P2+/+ mice indicating a role of P2 in the glial myelin lipid metabolism.¦Le diabète de type 2 touche 284 million de personnes dans le monde en 2010 et son évolution conduit dans la moitié des cas à une neuropathie périphérique diabétique. Bien que la neuropathie périphérique soit la complication la plus courante du diabète pouvant conduire jusqu'à l'amputation, sa physiopathologie est aujourd'hui encore mal comprise. Dans le but d'améliorer les connaissances moléculaires expliquant les mécanismes de la neuropathie liée au diabète de type 2, j'ai utilisé un modèle murin du diabète de type 2, les souris db/db.¦ln vivo, les enregistrements éléctrophysiologiques des animaux diabétiques montrent qu'en plus d'une diminution de la vitesse de conduction nerveuse, les souris db/db présentent également une augmentation de l'excitabilité nerveuse. Des mesures menées Ex vivo ont montré l'existence d'un phénotype d'hyperexcitabilité sur les nerfs périphériques isolés d'animaux diabétiques. Grâce à l'utilisation d'inhibiteurs pharmacologiques, nous avons pu démontrer que l'hyperexcitabilité démontrée était due à une réduction d'activité des canaux Kv1. En accord avec ces données, j'ai observé qu'une situation de diabète conduisait à une diminution des canaux Kv1.2 aux régions juxta-paranodales des nerfs périphériques db/db, alors que l'expression du transcrit et de la protéine restait stable. J'ai également confirmé l'absence de canaux Kv1.2 aux juxta-paranoeuds de biopsies de nerfs de patients diabétiques. L'ensemble de ces observations montrent que les nerfs périphériques chez les patients atteints de diabète de type 2 est due à une diminution des canaux potassiques rapides juxtaparanodaux les identifiant ainsi comme des cibles thérapeutiques potentielles.¦Les cellules de Schwann enveloppent et isolent les axones périphériques d'une membrane spécialisée, la myéline, composée de deux fois plus de lipides que de protéines. La protéine P2 (Pmp2 "peripheral myelin protein 2" ou FABP8 "fatty acid binding protein") est l'une des protéines les plus abondantes au système nerveux périphérique. P2 appartient à la famille de protéines FABP liant et transportant les acides gras et est une protéine cytosolique de 14,8 kDa exprimée du côté cytoplasmique de la myéline compacte.¦Afin d'étudier le rôle de P2 dans les cellules de Schwann myélinisantes, j'ai généré une souris knockout (P2-/-). Après avoir validé l'absence de transcrit et de protéine P2 dans les nerfs sciatiques P2-/-, des mesures électrophysiologiques ont montré une réduction modérée mais significative de la vitesse de conduction du nerf moteur périphérique. Il est important de noter que ces changements fonctionnels n'ont pas pu être associés à quelconque changement dans la structure de la myéline. Cependant, j'ai observé dans les nerfs périphériques P2-/-, une altération significative du niveau d'expression d'ARNm d'autres FABPs et en particulier FABP9. Ce dernier résultat démontre l'importance du rôle de la protéine P2 dans le métabolisme lipidique de la myéline.