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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Sacro-caudal musculoskeletal morphological diversity in catarrhines / 狭鼻類における仙尾部筋骨格形態の多様性

Tojima, Sayaka 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18106号 / 理博第3984号 / 新制||理||1574(附属図書館) / 30964 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 中務 真人, 教授 山極 壽一, 教授 疋田 努 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
2

MODELAMIENTO HIDROGEOLÓGICO PARA ESTIMAR EL CAUDAL ÓPTIMO DE LA PARTE BAJA DEL ACUÍFERO DEL VALLE DEL RÍO LURÍN

Díaz Jara, Paúl Jhonatan January 2015 (has links)
La parte baja del Acuífero del Valle del Río Lurín, el cual comprende los distritos de Lurín, Pachacamac y Cieneguilla, desde hace años viene sufriendo un déficit en sus reservas de aguas subterráneas, este problema se ha ido agravando durante el tiempo por el incremento no contralado de nuevos pozos, y la extracción no contralada de sus reservas de aguas subterráneas, la siguiente tesis trata de representar el comportamiento del Acuífero con la elaboración del modelo Matemático Visual ModFlow, con la finalidad de recomendar el caudal apropiado para evitar el descenso de la napa freática
3

Optimização do dimensionamento de projectos de mini-hídricas

Félix, Paulo Alexandre Alves January 2011 (has links)
Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Energia). Universidade do Porto. Faculdade de Engenharia. 2011
4

Morphology and possible function of Sepiella japonica Sasaki, 1929 (Sepiidae: Cephalopoda: Mollusca).

Hsueh, Meng-Min 29 July 2002 (has links)
The gland in the posterior end of Sepiella is a conspicuous structure, and is a diagnostic character of the genus Sepiella. Researches on this gland were few, with only Steenstrup¡]1879-80¡^described its morphology, and he thought it was very peculiar. One species of the genus Sepiella, S. japonica is a common species in fish markets in Taiwan; therefore, it was used to study the gland. Sasaki (1929) named the gland as the caudal gland, and it is followed here. The caudal gland is located at the posterior end of the mantle, along the midline, in between the two fins, and between the dorsal skin and the cuttlebone. The caudal gland is an egg-shaped cavity, and the walls of the cavity have many vertical folds. There is brown liquid in the cavity, and the liquid contains dark brown granules. The outer opening of the cavity is in the cleft between two fins, in the junction of fins and mantle, but closer to the ventral skin. There are iridophores in the connective tissue of the hypodermis of the dorsal skin above the caudal gland. As the cephalopod can control the activities of chromatophores, S. japonica may have the ability to control the expression of the caudal gland. There are circular muscles, posterior fin conjunctive muscle, surrounding the caudal gland, so we consider that the caudal gland can emit the secretions at well, and the muscle of the walls of caudal gland can assist to emit the secretions. Development of the caudal gland begins from the ventral side of the caudal gland. In embryo, the caudal gland is a lamellar epidermis. With growth, the front of the caudal gland evaginates and the caudal gland becomes sacciform gradually. The folds of the ventral walls of the caudal gland are more massive and complicated than those of the dorsal walls. There are many pores on the surface of caudal gland¡¦s walls. The secretion can be extruded from those pores. Histological sections of caudal glands indicated that the epidermis of the caudal gland is composed of simple columnar epithelial cells, and that the secretion is secreted from epithelial cells. There are many dark brown granules in the secretion of caudal glands. Some are spherical with a ciliary edge. Some are crystalloid. Some are transparent spherical balloons, and some are basophilic grains. The secretion also contains cells, including circular cells, cells with V- shaped nucleus, and cells with pseudopods. The secretion of caudal glands is organic, and also contains P, S, and Cl etc. The cobia juveniles fed with caudal glands or cuttlefish flesh drenched with caudal gland secretion disgorged the food immediately, indicating the cobias dislike something in the secretion. The length of the caudal gland is about 15.7¢Mof the dorsal mantel length of S. japonica. A positive trend between the caudal gland size and the dorsal mantle length was observed. The caudal gland sizes were not significantly different between male and female. The proportion of caudal gland length to dorsal mantle length of S. japonica was not significantly different between mature and immature individuals. The proportion was also not significantly different among seasons. It is concluded that defence is among the functions of the caudal gland.
5

Comportamento da artéria caudal bovina como enxerto biológico vascular alternativo: estudo Experimental em cães

ARRUDA FILHO, Mauro Barbosa January 1996 (has links)
Made available in DSpace on 2014-06-12T16:25:40Z (GMT). No. of bitstreams: 2 arquivo5379_1.pdf: 1580638 bytes, checksum: 5a645d832f6d02ae8e8bbf4a7abf46c3 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 1996 / Foram interpostos 20 segmentos de artéria caudal bovina, até então, considerada inédita, na aplicação clínica ou experimental, tratadas com glutaraldeído e formaldeído, nas artérias femorais de dez cães. O período de seguimento pós-operatório variou de 180 a 297 dias. Foram avaliados: Função motora, pulsos (à palpação e ao ultra-sônar), variações das pressões arteriais sistólica, diastólica e média e fluxo através do enxerto, assim como consistência, dilatação e coloração quando da retirada dos enxertos. Não houve óbitos, alteração da marcha ou infecção nas feridas operatórias. Houve trombose total (15%), trombose mural focal (30%), reação linfoplasmocitária focal da adventícia (100%), calcificação nas miocélulas (5%), reendotelização total (60%) e parcial (30%).Por apresentar adequação com diâmetro de pequenas artérias, ter comprimento suficiente para substituir ou atingir os diversos segmentos de artérias distais, apresentar rápida endotelização, bem como flexibilidade, demonstram a receptividade ao uso da ACB como enxerto vascular alternativo
6

Cellular and Molecular Mechanisms of Zebrafish Fin Regeneration

McMillan, Stephanie January 2016 (has links)
During fin regeneration, a blastema, a group of de-differentiated cells, forms underneath the wound epidermis. As regeneration proceeds, cells leave the proximal blastema and enter the differentiation zone. Adjacent to the differentiation zone, a subset of cells in the basal epidermal layer (BEL) express sonic hedgehog a (shha). Cells that come in contact with BEL differentiate into osteoblasts and joint cells, enabling the formation of bone segments at the end of each fin ray. Generally, fin regeneration occurs similarly in males and females. However, breeding tubercles (BT), keratinized epidermal structures on the male pectoral fin, result in regenerative differences when compared to females. In this thesis, three aspects of zebrafish fin regeneration were studied: 1) Cell lineage tracing of shha-expressing cells in the caudal fin regenerate; 2) The differentiation of joint cells and osteoblasts in the caudal fin regenerate; 3) Regeneration of pectoral fin BTs. Studies on caudal fin regenerates suggest osteoblasts and joint cells originate from a common cell lineage, but are committed to different cell fates. Joint cells follow a genetic pathway in which evx1 occurs downstream or parallel to hoxa13a and upstream of pthrp1. In the absence of Evx1, presumptive joint cells are committed to an osteoblast cell fate. Furthermore, joint cells do not regenerate following laser cell ablation, suggesting joint cell differentiation occurs only at specific intervals during osteoblast regeneration. Collectively, these results suggest a mechanism for joint cell differentiation during caudal fin regeneration. Studies on pectoral fins indicate androgens induce and estrogens inhibit BT formation. BT regeneration in males and androgen-treated females follows the initiation of revascularization, but occurs concomitantly with a novel second wave of angiogenesis. The inhibition of angiogenesis in androgen-treated females prevents BT formation. Altogether, these results suggest the growth and regeneration of BTs requires a v hormonal stimulus and the presence of an additional blood vessel network naturally found in males. In conclusion, these studies have increased the overall knowledge of key aspects of zebrafish fin regeneration. A gain in understanding zebrafish regeneration provides a basis in which treatments can be developed to induce regeneration in species with limited regenerative capabilities.
7

Evolution of the tail in the genus Macaca / マカク属における尾の進化

Wakamori, Hikaru 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22229号 / 理博第4543号 / 新制||理||1653(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 濱田 穣, 准教授 平﨑 鋭矢, 教授 髙井 正成 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
8

Caudal ambiental en el sitio Ramsar Lagunas de Guanacache, Desaguadero y del Bebedero, Argentina

Bastidas Mejía, Luis Bernardo 15 June 2023 (has links)
Definido por la Declaración de Brisbane de 2018, los caudales ambientales representan la cantidad, frecuencia, calidad y niveles de agua necesarios para sostener ecosistemas acuáticos, los cuales a su vez sustentan culturas, economías, formas de vida sustentables y bienestar social. El área de estudio, localizado a sotavento de la cordillera de los Andes, es el sitio Ramsar Lagunas de Guanacache, Desaguadero y del Bebedero. Se localiza entre los 34º06’ S y 32º00’ S y los 68º42’ O y 66º24’ O, (centro-oeste de la República Argentina). Esta región, caracterizada por su aridez, es regada por escurrimientos andinos, principalmente desde los ríos Mendoza, San Juan y Tunuyán. El sitio Ramsar representa un área de humedales cuyos ecosistemas y sociedades han sido perjudicados por la sobreexplotación del agua en los oasis. Para esta zona, es imprescindible la aplicación de los caudales ambientales, hecho posible mediante un consenso económico y un marco legal estricto que ampare la protección de estos espacios de humedales de zonas áridas. Dada la aridez natural, las actividades humanas en los oasis aguas arriba del sitio restringen las escorrentías al sitio Ramsar, por lo que es importante el estudio de los caudales ambientales. En estos términos, se analizaron múltiples metodologías (de tipo hidrológico), cuyas bondades radican en la capacidad de emular los ciclos hidrológicos naturales, destacando los métodos del Caudal de Mantenimiento, NGPRP (método del programa de las grandes llanuras septentrionales) y el método de la propuesta de modificación de la Ley argentina N.º 25688. Ante la aplicación de estas metodologías y como aporte científico relevante, se propuso una modificación que considerara las extensas distancias entre el sitio Ramsar y las estaciones de aforo aguas arriba, teniendo en cuenta de esta forma las pérdidas por infiltración y evapotranspiración en cauces. Por otra parte, se estudió el estado del balance hídrico regional, cuyos déficits denotan la sobreexplotación del recurso en los oasis aguas arriba. Asimismo, se analizó la relación sociedad-naturaleza dentro del sitio Ramsar, cuyos valores y cultura son alcanzados por los objetivos de los caudales ambientales. Asimismo, se determinaron los alcances y recomendaciones derivados de la declaración de Brisbane del año 2018, su vinculación con los objetivos del desarrollo sostenible y los escenarios relacionados al cambio climático, asociados al informe del Panel Intergubernamental del Cambio Climático (IPCC, 2021). Como conclusión, en la investigación se comprobó la alteración antrópica de los caudales afluentes al sitio Ramsar, siendo responsable de su degradación socioambiental. Por otra parte, los vínculos con el clima regional, su variabilidad y sus proyecciones (cambio climático) representan uno de los principales desafíos para la conservación de este espacio protegido. De esta forma y como propuesta, las opciones de restauración deben involucrar herramientas ambientales, económicas, legales y sociales (enmarcados dentro de las recomendaciones de implementación de los caudales ambientales), las cuales permitan un adecuado balance de consumo de agua para las sociedades y ecosistemas en la región. / Defined Brisbane Declaration set in 2018, environmental flows represent the quantity, timing, and quality of freshwater flows and levels necessary to sustain aquatic ecosystems (e.g., wetlands), which, in turn, support human cultures, economies, sustainable livelihoods, and well-being. The study area, located on the leeward side of the Andes Mountains, is the Ramsar site Lagunas de Guanacache, Desaguadero and Bebedero. It is located between 34º06' S and 32º00' S, and 68º42' W and 66º24' W, (central-western Argentina). This region, characterized by its aridity, is irrigated by Andean runoff, mainly from the Mendoza, San Juan and Tunuyán rivers. The Ramsar site represents an area whose wetlands ecosystems and societies have been harmed by overexploitation of water in the oases. Implementing environmental flows is essential for this area, made possible through economic consensus and a strict legal framework to protect these arid zone wetland areas. Given the natural aridity, human activities in the oases upstream of the site restrict runoff to the Ramsar site, so the importance of environmental flows begins to apply. Multiple hydrological methodologies were analyzed, whose benefits lie in the ability to emulate natural hydrological cycles. The most accurate methods assessed were Maintenance Flow, NGPRP (method of the Great Northern Plains Program) and the method of the proposed amendment of the Argentine Law No. 25688. Given the application of these methodologies and as a relevant scientific contribution, a modification was proposed to consider the long distances between the Ramsar site and the upstream gauging stations. The proposal aimed to consider the water losses due to infiltration and evapotranspiration in watercourses. On the other hand, the state of the regional water balance was analyzed, whose deficits denote the overexploitation of the resource in upstream oases. Likewise, the society-nature relationship within the Ramsar site was analyzed, whose values and the objectives of the environmental flows achieve culture. Also, the scopes and recommendations derived from the Brisbane declaration of 2018, its linkage with the objectives of sustainable development and scenarios related to climate change associated with the report of the Intergovernmental Panel on Climate Change (IPCC, 2021) were analyzed. In conclusion, the investigation verified the anthropic alteration of the tributary flows to the Ramsar site is responsible for its socio-environmental degradation. On the other hand, the links with the regional climate, its variability, and its projections (climate change) represent one of the main challenges for conserving this protected area. In this way and as a proposal, the restoration options must involve environmental, economic, legal and social tools (framed within the recommendations for implementing environmental flows), allowing an adequate water consumption balance for societies and ecosystems in the region.
9

Effect of Kinematics and Caudal Fin Properties on Performance of a Freely-Swimming Fin

Nayak, Anshul 23 December 2020 (has links)
Traditionally, underwater vehicles have been using propellers for locomotion but they are not only inefficient but generate large acoustic signature. Researchers have taken inspiration from efficient swimmers like fish to address the issue with alternate propulsion mechanism. Mostly, research on fish locomotion involved studying a foil tethered to a fixed point inside uniform flow. A major drawback of such study is that neither it resembles a freely swimming fish nor it takes into consideration the dynamics of moving fish on propulsive forces. Hence, in our current study, we focus on comparing the performance of a free swimming fin over tethered fin both experimentally and numerically. Experimentally, we focus on the oscillatory form of locomotion where the caudal fin pitches to generate necessary thrust as seen in boxfish. We intend to investigate the Caudal fin kinematics and its physical properties on locomotion performance. To better understand, we build an automated robo-physical model that swims in a circular path so as to carry extensive experiments. We focus on understanding the effect of flexibility, shape and thickness of caudal fin on performance. Currently, we have studied three different flexibility and for each flexibility, we studied three different shape. We found there must be an optimal flexibility for minimising the Cost of Transport (COT). We also propose that the steady forward speed linearly varies with tail tip velocity. Furthermore, we investigated the effect of thickness of fin and considered uniform and tapered fin with equal area moment of inertia. Numerically, we investigated the effect of phase offset between heave and pitch motion on the performance of a freely swimming fin and compared that to a tethered fin. A freely-swimming fin self propels and moves with steady speed while a tethered fin remains stationary and actuates under uniform flow. We model the fin as a rigid body undergoing prescribed motion in an inviscid fluid and solved for coupled interaction using panel method. We show the effect of phase offset for optimum performance and found a significant difference between tethered and freely swimming fin. / M.S. / Underwater vehicles use propeller based mechanism but they are inefficient and generate noise. Researchers have taken inspiration from nature to replace propellers with efficient propulsion mechanism. In the current study, we design a robotic model to understand the effect of various kinematic and physical properties of tail fin on performance. Our research is unique from past study in the aspect that most research involved studying performance using a robotic model fixed at its position which does not resemble a freely-swimming fish. Hence, in our current study, we focus on comparing the performance of our freely swimming model with tethered fin. The robot has one degree of freedom and can pitch its tail to generate thrust. We intend to investigate the tail fin kinematics and its physical properties on locomotion performance. We focus on understanding the effect of flexibility, shape and thickness of fin on performance. Currently, we have studied three different flexibility and for each flexibility, we studied three different shape. We showed there exists an optimal flexibility for maximising efficiency. For any fin undergoing combined pitch and heave motion, there exists a phase offset between them which will maximise the performance. Researchers have tried to understand its impact using both experiment and numerical simulation. In the current study, we study the impact of phase offset between pitch and heave for a freely-swimming fin and compare that to a fixed fin. A freely-swimming fin self propels and moves with steady speed while a tethered fin remains stationary and actuates under uniform flow. We show the effect of phase offset for optimum performance and found a significant difference between tethered and freely swimming fin.
10

Apprentissage et mémorisation de la trajectoire d'une cible visuelle en mouvement : étude neuro-psycho-physiologique chez le primate non-humain / Learning and memorization of the trajectory of a moving visual target : neuro-psycho-physiological study in the non-human primate

Bourrelly, Clara 30 November 2017 (has links)
Suivre du regard un objet qui se déplace dans le champ visuel constitue un défi facilement relevé par le système nerveux central. Ce suivi consiste en une succession de mouvements rapides (saccades) et lents (poursuites) des yeux. La précision spatiotemporelle implique une annulation du délai entre l'activité rétinienne et la contraction des muscles extra-oculaires, et nécessite que la trajectoire de la cible soit connue et mémorisée. La question de l'élaboration de cette mémoire a été longtemps négligée, et les substrats neuronaux sous-jacents largement méconnus. L'objectif de mon travail était de mieux comprendre comment la trajectoire d'un objet est mémorisée et restituée lors du suivi oculaire d'une cible mobile. Il s'agissait en effet de caractériser comment s'opère la synergie entre les deux composantes oculaires (saccade et poursuite). Un premier versant comportemental, renseigne sur la mémorisation d'une trajectoire spatiotemporelle. Un second versant neurophysiologique, révèle le rôle du cervelet dans la restitution de cette trace mnésique. Au-delà de leur intérêt fondamental pour la neurologie, mes travaux apportent les prérequis pour accroître nos connaissances sur la mémorisation d'un évènement spatialement dynamique et pose les bases pour une compréhension neurophysiologique de la présence visuomotrice. / To track an object that moves in the visual field is a challenge easily executed by the central nervous system. This tracking consists of a succession of rapid (saccades) and slow (pursuit) eye movements. Spatiotemporal accuracy involves a cancellation of the delay between retinal activity and contraction of the extraocular muscles and requires that the trajectory of the target has been known and memorized. However, very few studies tried to explain how this memory was constructed, and the underlying neuronal substrates are largely unknown. The objective of my work was to better understand how the trajectory of an object is memorized and restored during the tracking of a moving target. The aim was to characterize the synergy between the two ocular components (saccade and pursuit). The first behavioral part of this work informs on the memorization of a spatiotemporal trajectory. The second neurophysiological part reveals the role of the cerebellum in the restitution of this memory. Beyond their fundamental interests in neurology, my work provides the prerequisites to increase our knowledge on the memorization of a spatially dynamic event.

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