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Caractérisation et stabilité de la matière organique du sol en contexte montagnard calcaire : proposition d'indicateurs pour le suivi de la qualité des sols à l'échelle du paysageSaenger, Anais 16 April 2013 (has links) (PDF)
Les sols de montagne représentent d'importants réservoirs de carbone (C) potentiellement vulnérables aux changements climatiques et changements d'usage qui les affectent de manière amplifiée. Or la grande variabilité de ces milieux, leur faible accessibilité ainsi que le manque d'outils de mesure appropriés limitent nos connaissances qui restent aujourd'hui très fragmentaires en ce qui concerne les stocks, la chimie et la réactivité du carbone organique des sols (COS). Ces informations sont pourtant nécessaires pour appréhender l'évolution de ces sols et de leur C dans ce contexte de changements globaux. Les objectifs de ce travail de thèse étaient (i) d'accéder à une meilleure compréhension de la nature, de la stabilité et de la vulnérabilité du COS dans une mosaïque d'écosystèmes des Préalpes calcaires (massif du Vercors), (ii) de rechercher des outils de caractérisation rapides et fiables adaptés à l'étude et au suivi du COS à l'échelle du paysage, et enfin (iii) de proposer des indices pour l'évaluation et le suivi de la qualité des sols en milieu de montagne. Dans un premier temps, nous avons testé l'application de la pyrolyse Rock-Eval pour l'étude du COS à grande échelle sur un ensemble d'unités écosystémiques. Nous avons ensuite comparé la pyrolyse Rock-Eval à deux techniques classiques d'étude de la matière organique du sol (MOS) : le fractionnement granulodensimétrique de la MOS et la spectroscopie moyen infrarouge. Ces approches analytiques couplées nous ont permis de quantifier les stocks de C à l'échelle de la zone d'étude et d'expliquer la stabilité et la vulnérabilité du COS sous des angles variés. Les facteurs responsables des patrons observés dans les différentes unités écosystémiques sont discutés. Ce travail a également confirmé la pertinence de l'outil Rock-Eval pour répondre aux objectifs fixés. Parallèlement, des approches biologiques nous ont permis d'évaluer l'importance de la composante microbienne dans ces sols. Enfin, des indices évaluant le statut organique des sols (stockage de COS, fertilité des sols, vulnérabilité du COS) sont proposés pour constituer des outils de gestion et d'aide à la décision.
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A Concept of inter-AS Priority Signaling using BGP AttributesKnoll, Thomas Martin 04 February 2009 (has links)
The increasing number of delay and loss critical
services in packet networks require differentiated packet
handling in the forwarding plane. Quality of Service (QoS)
guarantees can be given for networks using resource reservation
and admission control. However, such strategies require complex
control plane extensions and might lead to higher operation
expenditures.
Network operators therefore often use over-provisioning and
traffic differentiation to offer cheaper class of service quality in
their internet protocol (IP) packet networks.
Priority marking and forwarding of packetized data traffic
can be realized mainly using different layer two and three
mechanisms. The number of differentiated classes and their
autonomous system (AS) internal implementation is at the
operator’s choice.
This paper proposes a concept of cross-domain and cross-layer
priority signaling between packet switched networks to be used
at the inter-AS peering points. It makes use of the Border
Gateway Protocol (BGP) as the predominantly used routing
protocol for AS peering communication. A new BGP-4 path
attribute is used to convey the structured priority information.
The new concept ensures that all receiving AS peers are
consistently and comprehensively informed about the QoS
handling within the IP prefix originating AS. Based on this
information, all ASes can perform close QoS treatment
approximation in a cross-domain and cross-layer manner.
The approach is now work in progress at the IETF.
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Class of Service based AS InterconnectionKnoll, Thomas Martin 04 February 2009 (has links)
The increasing number of delay and loss critical services in packet networks require differentiated packet handling in the forwarding plane. Quality of Service (QoS)
guarantees can be given for networks using resource reservation and admission control. However, such strategies require complex control plane extensions and might lead to higher operation expenditures.
Network operators therefore often use over-provisioning and
traffic differentiation to offer cheaper Class of Service (CoS)
quality in their internet protocol (IP) packet networks.
The number of differentiated classes and their autonomous
system (AS) internal implementation is at the operator’s choice.
This paper proposes a signalling concept for inter-AS layer
three Class Set signalling, supported classes, their encoding and
packet rate limitations. It makes use of the Border Gateway
Protocol (BGP) as the predominantly used routing protocol for
AS peering communication. The paper specifies two new nontransitive
attributes, which enable adjacent peers to signal Class
of Service capabilities and admission control limitations. The new
"CoS Capability Attribute" and the “CoS Parameter Attribute"
are simple data structures, which signal the classes, their per hop
behaviour (PHB) ID code and the token bucket control
performed at the ingress AS border router for rate limitation
purposes. The denoted Class of Service forwarding support is
meant as the AS externally available (transit) Class of Service
support.
The approach is now work in progress at the IETF.
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BGP Class of Service InterconnectionKnoll, Thomas Martin 04 February 2009 (has links)
This document focuses on Class of Service Interconnection at inter-
domain peering points. It specifies two new non-transitive
attributes, which enable adjacent peers to signal Class of Service
Capabilities and certain Class of Service admission control
Parameters. The new "CoS Capability Attribute" is deliberately kept
simple and denotes the general EF, AF Group and BE forwarding support
across the advertising AS. The second "CoS Parameter Attribute" is
of variable length and contains a more detailed description of
available forwarding behaviours using the PHB id Code encoding. Each
PHB id Code is associated with rate and size based traffic
parameters, which will be applied in the ingress AS Border Router for
admission control purposes to a given forwarding behaviour. The denoted Class of Service forwarding support is meant as the AS
externally available (transit) Class of Service support.
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Cuerpo y violencia y en México (1988-2018). Un estudio sobre la permeabilidad de la violencia en las artes contemporáneas mexicanas y sus repercusiones en el entendimiento del cuerpoMéndez Landa, Francisco Javier 02 March 2021 (has links)
[ES] La presente Tesis Doctoral constituye un estudio sobre las formas en que la violencia contemporánea en México ha repercutido el campo de las artes visuales, con un especial énfasis en la forma de entender y representar el cuerpo humano.
Acotado en tres décadas (1988-2018), este trabajo es una investigación contextual que se afianza en el entramado social, político, histórico y económico para construir un análisis más profundo en torno a las formas en que la violencia ha trastocado igualmente el ámbito artístico, y poder ver cómo, a lo largo del tiempo, se ha modificado la imagen del cuerpo humano en la producción artística, gracias a que, por una parte, la muerte se presenta con más frecuencia en lo cotidiano y, por otra, los grupos criminales han recrudecido sus formas de ejercer violencia.
Este panorama facilitó que muchos delitos graves se volvieran comunes, y poco a poco, los criminales llegaran a ejecutar actos violentos novedosos permitiendo nuevas formas de relación y trato con el cuerpo humano.
Si con el paso del tiempo el crimen organizado ha vulnerado el cuerpo humano de formas cada vez más atroces, haciendo además un esfuerzo por visibilizarlos y acercarlos a la sociedad civil, ciertos artistas pueden ver en ello una oportunidad para reflexionar y construir nociones del cuerpo hasta ahora inéditas, como la de imaginar un cuerpo volátil, manifestado en la obra Vaporización (2001) de la artista sinaloense Teresa Margolles, donde propone un espacio lleno de vapor, consecuencia de alimentar condensadores situados al interior del museo, con agua previamente usada para lavar cadáveres en la morgue. El cuerpo que aquí presenta Margolles, anula toda figuración sólida y adquiere la capacidad incluso de flotar y adherirse a la piel y ropa del visitante, quién saldrá del espacio portando una milimétrica esencia humana ajena a su ser. Otro ejemplo son las concepciones humanas más cercanas a la máquina y la alta tecnología propias de las investigaciones del artista mexicano Rafael Lozano-Hemmer quién visualiza cuerpos humanos dependientes del código binario y que no dejan de ser inquietantes luego de reconocer que muchos de estos artefactos tecnológicos son igualmente usados tanto por el ejército como por los criminales en sus abyectos actos.
Así, esta Tesis parte de un análisis contextual del México reciente, dejando cronológicamente el punto de inflexión de esta escalada de violencia -el año 2006- cerca de la mitad del período de tiempo estudiado para tener un antes y un después de la Declaración de Guerra por parte del Estado y permitir una cierta distancia en el análisis de las repercusiones en el arte de este enfrentamiento bélico.
La segunda parte constituye un corpus teórico donde convergen reflexiones relativas a la violencia, la memoria y el duelo, para posteriormente reparar en el cuerpo humano y sus múltiples posibilidades. Lo anterior sirve de preámbulo para poder entender cómo el ser humano, en su total fragilidad, se ve afectado por agentes endógenos y exógenos que terminan por provocarle la muerte -una muerte impregnada con mayores o menores dosis de violencia-, para luego investigar sus correlatos en el campo artístico. Este análisis brinda un panorama del trabajo y pensamiento alrededor del cuerpo y permite ver cómo la violencia ha jugado un papel importante no solo en el contexto socio político de México, sino también en la forma de pensar e imaginar el cuerpo.
Finalmente, gran parte de la riqueza de esta investigación proviene de las aportaciones de fuentes primarias, como son las entrevistas que pude realizar a más de veinticinco artistas, curadores e investigadores vivos que, en sus propias palabras, ayudan a entender los cambios que ha vivido México, sus artistas y la noción de cuerpo en las tres últimas décadas. / [CA] La present Tesi Doctoral constitueix un estudi sobre les formes en què la violència contemporània a Mèxic ha repercutit el camp de les arts visuals, amb un especial èmfasi en la manera d'entendre i representar el cos humà.
Delimitat en tres dècades (1988-2018), aquest treball és una investigació contextual que s'aferma en l'entramat social, polític, històric i econòmic per a construir una anàlisi més profunda entorn de les formes en què la violència ha trastocat igualment l'àmbit artístic, i poder veure com, al llarg del temps, s'ha modificat la imatge del cos humà en la producció artística, gràcies a que, d'una banda, la mort es presenta amb més freqüència en el quotidià i, per una altra, els grups criminals han empitjorat les seues maneres d'exercir violència.
Aquest panorama va facilitar que molts delictes greus es tornaren comuns, i a poc a poc, els criminals arribaren a executar actes violents nous permetent noves formes de relació i tracte amb el cos humà.
Si amb el pas del temps el crim organitzat ha vulnerat el cos humà de formes cada vegada més atroços, fent a més un esforç per visibilitzar-los i acostar-los a la societat civil, uns certs artistes poden veure en això una oportunitat per a reflexionar i construir nocions del cos fins ara inèdites, com la d'imaginar un cos volàtil, manifestat en l'obra Vaporización (2001) de l'artista sinaloense Teresa Margolles, on proposa un espai ple de vapor, conseqüència d'alimentar condensadors situats a l'interior del museu, amb aigua prèviament usada per a llavar cadàvers en la morgue. El cos que ací presenta Margolles, anul·la tota figuració sòlida i adquireix la capacitat fins i tot de surar i adherir-se a la pell i roba del visitant, qui eixirà de l'espai portant una mil·limètrica essència humana aliena a la seua ser. Un altre exemple són les concepcions humanes més pròximes a la màquina i l'alta tecnologia pròpies de les investigacions de l'artista mexicà Rafael Lozano-Hemmer qui visualitza cossos humans dependents del codi binari i que no deixen de ser inquietants després de reconéixer que molts d'aquests artefactes tecnològics són igualment usats tant per l'exèrcit com pels criminals en els seus abjectes actes.
Així, aquesta Tesi parteix d'una anàlisi contextual del Mèxic recent, deixant cronològicament el punt d'inflexió d'aquesta escalada de violència -l'any 2006- prop de la meitat del període de temps estudiat per a tindre un abans i un després de la Declaració de Guerra per part de l'Estat i permetre una certa distància en l'anàlisi de les repercussions en l'art d'aquest enfrontament bèl·lic.
La segona part constitueix un corpus teòric on convergeixen reflexions relatives a la violència, la memòria i el duel, per a posteriorment reparar en el cos humà i les seues múltiples possibilitats. L'anterior serveix de preàmbul per a poder entendre com l'ésser humà, en la seua total fragilitat, es veu afectat per agents endògens i exògens que acaben per provocar-li la mort -una mort impregnada amb majors o menors dosis de violència-, per a després investigar els seus correlats en el camp artístic. Aquesta anàlisi brinda un panorama del treball i pensament al voltant del cos i permet veure com la violència ha jugat un paper important no sols en el context soci polític de Mèxic, sinó també en la manera de pensar i imaginar el cos.
Finalment, gran part de la riquesa d'aquesta investigació prové de les aportacions de fonts primàries, com són les entrevistes que vaig poder realitzar a més de vint-i-cinc artistes, commissari i investigadors vius que, en les seues pròpies paraules, ajuden a entendre els canvis que ha viscut Mèxic, els seus artistes i la noció de cos en les tres últimes dècades. / [EN] This Doctoral Thesis constitutes a study on the ways in which contemporary violence in Mexico has impacted the field of visual arts, with a special emphasis on understanding and representing the human body.
Limited to three decades (1988-2018), this work is a contextual investigation that is strengthened in the social, political, historical and economic framework to build a deeper analysis around the ways in which violence has also disrupted the artistic field, and to be able to see how, over time, the image of the human body has been modified in the artistic production, thanks to the fact that, on one hand, death is more frequently presented in everyday life and, on the other, criminal groups have intensified their ways of exercising violence.
This panorama made serious crimes become common, and little by little, the criminals execute new violent acts with new forms of relation and treatment with the human body.
Though over the years organized crime has violated the human body in increasingly atrocious ways, also making an effort to make them visible and bring them closer to civil society, certain artists can see in this an opportunity to reflect on and work on notions of the body unpublished to this day, such as imagining a volatile body, as manifested in the work Vaporización (2001) by Sinaloan artist Teresa Margolles, where she proposes a space full of steam, the result of feeding condensers located inside the museum with water previously used to wash corpses in the morgue. The body presented here by Margolles cancels out all solid figuration and acquires the capacity to float and adhere to the skin and clothes of the visitor, who will leave the space carrying a millimetric human essence alien to his being. Another example is the human conceptions closer to the machine and high technology, typical of the investigations of mexican artist Rafael Lozano-Hemmer, who visualizes human bodies dependent on the binary code and which do not cease to be disturbing after recognizing that many of these technological artifacts are equally used by the army and by criminals in their abject acts.
This Thesis starts from a contextual analysis of México recently, leaving chronologically the turning point of this escalation of violence - the year 2006 - about half of the period of time studied to have a before and after the Declaration of War by the State and allow a certain distance in the analysis of the repercussions in art of this warlike confrontation.
The second part constitutes a theoretical corpus where reflections on violence, memory and grief converge, to later repair the human body and its multiple possibilities. This serves as a preamble to understand how human beings, in their total fragility, are affected by endogenous and exogenous agents that end up causing death - a death impregnated with greater or lesser doses of violence - and then investigate its correlations in the artistic field. This analysis provides a panorama of the work and thoughts around the body and allows us to see how violence has played an important role not only in the socio-political context of México, but also in the way of thinking and imagining the body.
Finally, a lot of the richness of this research comes from the contributions of primary sources, such as the interviews I was able to conduct with more than twenty-five living artists, curators and researchers who, in their own words, help to understand the changes that México, its artists and the notion of body have undergone in the last three decades. / Méndez Landa, FJ. (2021). Cuerpo y violencia y en México (1988-2018). Un estudio sobre la permeabilidad de la violencia en las artes contemporáneas mexicanas y sus repercusiones en el entendimiento del cuerpo [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/162917 / TESIS
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Dynamic bandwidth allocation MAC protocols for gigabit-capable passive optical networksChang, Ching-Hung January 2008 (has links)
The research initiatives addressed in this thesis are geared towards improving the performance of passive optical networks (PONs) through the development of advanced dynamic bandwidth allocation (DBA) protocols. In particular, the aim of the research undertaken is to enhance the quality of service (QoS) offered by standard PONs by means of providing subscribers with service level agreement (SLA) to fulfil applications and associated bandwidth requirements on demand. To accomplish the research objectives, a novel service and bandwidth focused DBA protocol is developed for standard time division multiplexing (TDM), gigabit-capable PONs (GPONs) by flexibly assigning a guaranteed minimum bandwidth to each optical network unit (ONU),terminated at subscribers premises. Modelling and simulation of the developed algorithms have displayed a tenfold enhancement in network performance, showing a superior performance to other published DBA protocols, in terms of mean packet delay. To accomplish protocol optimisation, the ONU upstream transmission properties of TDM-PONs have been further analysed and subsequently the ONU data transfer order in each communication cycle has been dynamically configured to increase the network upstream throughput by overlapping the upstream transmission period with parts of the bandwidth request-allocation process between OLT and ONUs. In addition, with the objective of extending the application of the developed protocol to long-reach PONs by means of reducing the augmented propagation delays due to the network’s extensive reach, the concept of virtual communication cycles has been incorporated into the optimised DBA algorithm. This approach demonstrates comparable transmission efficiency in the context of subscriber throughput and packet delay as in a standard PON but at much longer distances from the network exchange. To overcome the inevitably limited communication capacity of single wavelength TDM protocols and with the transportation of the ever increasing, time-sensitive, multi-media services in mind, a novel multi-wavelength DBA protocol is then developed to be applied to a wavelength division multiplexing–PON. With this protocol, both the downstream and upstream network capacity is dynamically adjusted according to subscribers’ service level and bandwidth demand in each polling cycle as opposed to a fixed upstream network capacity in TDM-PONs. It therefore also demonstrates improved upstream transmission efficiency.
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Soil organic carbon (SOC) now and in the future. Effect of soil characteristics and agricultural management on SOC and model initialisation methods using recent SOC data / Le carbone du sol maintenant et dans le futur. Impact de gestion agricole et importance de l'initialisation des modèlesNemoto, Rie 19 December 2013 (has links)
La concentration de Carbone organique de sol (COS) et les émissions de gaz à effet de serre (GES) ne sont pas uniformes à travers l’espace, mais se regroupent en “hotspots” dans des endroits spécifiques. Ces différences s’expliquent principalement par les activités anthropiques telles que la gestion agricole. 40-50% de la surface de la Terre est utilisé par l’agriculture, par exemple les terres cultivées, les prairies gérées et cultures permanentes, y compris l’agro-foresterie et de bio-cultures énergétiques. En outre, 62% du carbone globale est COS, et le sol conserve plus que 3 fois plus de C que l’atmosphère. Ainsi, la séquestration du carbone dans les sols agricoles joue un rôle potentiellement important dans l’augmentation de stockage de COS et l’atténuation des GES, et il y a un intérêt considérable pour comprendre les effets de la gestion agricole sur le COS et les flux de GES aux prairies et terres cultivées, afin de mieux évaluer l’incertitude et la vulnérabilité des réservoirs de COS. Afin de découvrir les pratiques de gestion agricole qui contribuent à la séquestration efficace et durable du carbone aux terres agricoles en Europe, il est essentiel de simuler les stocks futurs de carbone terrestriel et les budgets de GES par rapport aux systèmes de gestion agricole variés sur les grands écosystèmes européens. Dans ce contexte, la modélisation est une méthode utile, et la modélisation a déjà été utilisée dans beaucoup d’études. Cependant beaucoup de résultats de la modélisation n’ont pas encore été validés avec les données mesurées sur l’horizon long-terme, et d’ailleurs d’autres études ont constaté un fort impact de l’initialisation du modèle sur le résultat du modèle. Néanmoins, la variabilité des prévisions annuelles et décennales concernant le C et le GES en Europe dépendent des résultats du modèle. Par conséquence, il est important de trouver la meilleure méthode d’initialisation des modèles pour obtenir des résultats des modèles fiables, notamment pour les modèles d’écosystèmes dits “process-based”. Au cours des dernières années, Zimmermann et al. (2007) a réussit à initialiser le modèle de Rothamsted carbone (RothC) en utilisant une méthode (physique et chimique) de fractionation des sols. Pour cette raison, j’ai fait l’hypothèse que les données COS détaillées seraient utiles pour initialiser des modèles d’écosystème, et que cette hypothèse doit être testée avec les modèles différents par rapport aux gestions agricoles différentes. Les buts de cette thèse sont les suivants: i) évaluation des influences des gestions agricoles sur le stockage de COS, en utilisant des approches expérimentales et des approches de modélisation; et ii) déterminer la meilleur méthode d’initialisation des modèles. (...) / Soil organic carbon (SOC) concentrations and greenhouse gas (GHG) emissions are not uniform across the landscape, but assemble in “hotspots” in specific areas. These differences are mainly driven by human-induced activities such as agricultural management. 40-50% of the Earth’s land surface is under agricultural land-use, for instance cropland, managed grassland and permanent crops including agro-forestry and bio-energy crops. Furthermore, 62% of the global soil C stock is SOC and the soil stores more than 3 times more C than the atmosphere. Thus, C sequestration in agricultural soil has a potentially important role in increasing SOC storage and GHG mitigation, and there is considerable interest in understanding the effects of agricultural management on SOC and GHG fluxes in both grasslands and croplands, in order to better assess the uncertainty and vulnerability of terrestrial SOC reservoirs. For the sake of discovering the agricultural management practices relating to the effective and sustainable C sequestration in agricultural lands in Europe, simulating future terrestrial C stocks and GHG budgets under varied agricultural management systems in major European ecosystems is essential. Using models is a useful method with the purpose of this and abundant studies have carried out. However, many model results have not been validated with reliable observed long-term data, while other studies have reported a strong impact of model initialisation on model result. Nevertheless, predictions of annual to decadal variability in the European terrestrial C and GHG ressources largely rely on model results. Consequently, finding the most appropriate and comprehensive model initialisation method for obtaining reliable model simulations became important, especially for process-based ecosystem models. In recent years, Zimmermann et al. (2007) have succeed in initialising the Rothamsted Carbon model (RothC) using a physical and chemical soil fractionation method. For that reason, we hypothesised that measured detailed SOC data would be useful to initialise ecosystem models, and this hypothesis should be tested for different process-based models and agricultural land-use and management. (...)
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Estudi estructural, ultraestructural i histoquímic de les glàndules sexuals accessòries del mascle reproductor porcí (Sus domesticus)Badia Brea, Maria Elena 22 October 2003 (has links)
El present treball analitza al microscopi òptic i al microscopi electrònic de transmissió les glàndules sexuals accessòries de Sus domesticus (raça Landrace - varietat anglesa) a partir de mascles reproductors porcins adults i sans. Un millor coneixement dels patrons estructural i ultraestructural normals de las glàndules sexuals accessòries permetrà diagnosticar amb facilitat quina ha estat l'estructura o la funció glandular afectada en mascles en els que s'observa una disminució de la qualitat del semen. Per altra banda, els estudis anatomopatològics s'han de complementar amb tècniques histoquímiques que generalment permeten confirmar o excloure un diagnòstic histopatològic previ.Les glàndules sexuals accessòries del mascle reproductor porcí estan molt desenvolupades i inclouen les glàndules vesiculars, la pròstata i les glàndules bulbouretrals. L'epiteli secretor de les glàndules vesiculars està format per cèl·lules columnars, cèl·lules basals i mastòcits. Les cèl·lules columnars es caracteritzen per presentar tres morfologies diferents que es consideren diferents estadis d'un mateix tipus cel·lular: les cèl·lules principals, les cèl·lules clares i les cèl·lules denses. Les cèl·lules principals secreten activament glicoproteïnes N- i O- glicosilades amb residus d'α-L-fucosa, α(16)fucosa, α-D-mannosa, α-D-glucosa, α- i -D-N-acetilgalactosamina, -D-galactosa-(13)-D-N-acetilgalactosamina, α-D-galactosa, galactosa-(14)-N-acetilglucosamina, D-N-acetilglucosamina i àcid neuramínic. Aquestes glicoproteïnes afavoreixen les interaccions entre l'espermatozoide i l'occit i regulen la permeabilitat de la membrana espermàtica. La pròstata està formada per dues porcions glandulars, el cos de la pròstata (BP) y la pròstata disseminada (DP), entre las quals s'observen diferencies estructurals, ultraestructurals, histoquímiques i funcionals. En ambdues porcions, l'epiteli secretor està constituït per cèl·lules columnars principals, denses i cèl·lules basals, i també per cèl·lules cúbiques en el BP i per cèl·lules mucoses en la DP. En ambdues porcions glandulars, se sintetitzen i secreten N- i O- glicoproteïnes neutres i àcides. Aquestes glicoproteïnes s'alliberen mitjançant un mecanisme regulat en el BP y mitjançant un mecanisme regulat i un constitutiu en la DP. Les glucoproteïnes luminals del BP contenen residus de fucosa, mannosa, α- i -D-N-acetilgalactosamina, galactosa-(14)-N-acetilglucosamina, D-N-acetilglucosamina i àcid neuramínic. En la DP les glicoproteïnes presenten, a més, -D-galactosa-(13)-D-N-acetilgalactosamina i α-D-galactosa. Les glicoproteïnes secretades en el BP i en la DP per via regulada, participen en el control de l'estabilitat del plasmalemma dels espermatozoides, eviten la resposta immune uterina i l'aglutinació dels espermatozoides i afavoreixen la seva motilitat progressiva. Les glicoproteïnes secretades per via constitutiva en la DP protegeixen i lubrifiquen la uretra pelviana.L'epiteli secretor de les glàndules bulbouretrals està format per cèl·lules piramidals principals i denses. Les cèl·lules principals sintetitzen i secreten principalment O-glicoproteïnes àcides carboxilades i sulfatades amb residus glicosídics d'N-acetilgalactosamina, -D-galactosa-(13)-D-N-acetilgalactosamina, α-D-galactosa, D-N-acetilglucosamina i àcid neuramínic. Aquests residus proporcionen resistència a la proteolisi a les O-glicoproteïnes secretades, les quals participen en la lubrificació y protecció de l'epiteli, i intervenen en el control de la permeabilitat del plasmalemma dels espermatozoides i en el transport d'ions al seu través. / The present study evaluates by means of light and transmission electron microscopy, the accessory sex glands coming from adult and healthy boars (Sus domesticus Landrace breed - British variety). A deeper knowledge of the normal structural and ultrastructural patterns of the accessory sex glands will allow diagnosing easily the structure or the glandular function affected when a low spermatic quality is observed. On the other hand, anatomopathological studies must to be complemented with histochemical techniques which generally allow confirming or rejecting a previous histopathological diagnostic. The boar accessory sex glands were very developed and formed by the vesicular glands, the prostate and the bulbourethral glands. Columnar cells, basal cells and mast cells composed the secretory epithelium of the vesicular glands. Columnar cells showed three morphologies, which were considered different stages of the same cell typology and named: principal cells, clear cells and dense cells. Principal cells secreted actively N- and O- glycoproteins that exhibited residues of: α-L-fucose, α(16)fucose, α-D-mannose, α-D-glucose, α- and -D-N-acetilgalactosamine, -D-galactose-(13)-D-N-acetilgalactosamine, α-D-galactose, galactose-(14)-N-acetilglucosamine, D-N-acetilglucosamine and neuraminic acid. These glycoproteins improve sperm-oocyte interactions and regulate plasma membrane permeability.The prostate was constituted by two glandular portions, the prostate body (PB) and the disseminate prostate (DP). Both of them showed structural, ultrastructural, histochemical and functional differences. Principal columnar cells, dense columnar cells and basal cells composed the secretory epithelium of these two glandular parts. The PB contained also cubic cells and the DP contained mucous cells. Both glandular portions synthesised and secreted N- and O- neutral and acid glycoproteins. These glycoproteins were thought to be released by a regulated pathway in the BP while in the DP the glycoproteins seemed to follow a regulated and a constitutive pathway. The BP luminal glycoproteins exhibited residues of: fucose, mannose, α- and -D-N-acetilgalactosamine, galactose-(14)-N-acetilglucosamine, D-N-acetilglucosamine and neuraminic acid. The DP glycoproteins also contained -D-galactose-(13)-D-N-acetilgalactosamine and α-D-galactose residues.The BP and the DP glycoproteins secreted by the regulated pathway participate in the control of sperm membrane stability, avoid uterine immune response and sperm agglutination and, improve their progressive motility. The DP glycoproteins secreted by the constitutive pathway protect and lubricate the pelvic urethra.Principal and dense piramidal cells composed the secretory epithelium of the bulbourethral glands. The principal cells mainly synthesised and secreted carboxylated and sulfated acid O-glycoproteins with residues of: N-acetilgalactosamine, -D-galactose-(13)-D-N-acetilgalactosamine, α-D-galactose, D-N-acetilglucosamine and neuraminic acid. These O-linked oligosaccharides make these proteins extremely resistant to proteolysis, provide lubrication and protection to the epithelium, and participate in ion transport throughout the plasma membrane.
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Traffic Engineering with MPLS and QOSIkram, Imran January 2009 (has links)
In the modern era there exist applications that require very high resources and generate a tremendous amount of traffic so they require considerable amount of bandwidth and QOS to operate and perform correctly. MPLS is a new and a fast technology that offers much remuneration both in terms of providing trouble-free and efficient security together with the high speed of switching. MPLS not only guarantees quality of service of IP networks but in addition to provides scope for traffic engineering it offers many enhanced features of IP networks as it does not replace IP routing, but works along with existing and future routing technologies to provide high-speed data forwarding between label-switched routers (LSRs) together with QOS. Many network carriers are facing the problem of how to accommodate such ever-growing demands for bandwidth. And the static nature of current routing algorithms, such as OSPF or IS-IS, the situation is going even worse since the traffic is concentrated on the "least cost" paths which causes the congestion for some links while leaving other links lightly loaded. Therefore, MPLS traffic engineering is proposed and by taking advantage of MPLS, traffic engineering can route the packets through explicit paths to optimize network resource utilization and traffic performance. MPLS provides a robust quality of service control feature in the internet. MPLS class of service feature can work in accordance with other quality of service architectures for IP networks.
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ESTABLISHING AND MANIPULATING THE DIMERIC INTERFACE OF VISUAL/NON-VISUAL OPSINSComar, William D., Ph.D. 12 October 2018 (has links)
No description available.
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