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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

Liens entre la morphologie et les marques épigénétiques, la qualité de l'ADN, le contenu chromosomique et les capacités fécondantes du spermatozoïde humain / How to link human sperm morphology to its epigenetic status, DNA integrity, chromosome content and fecundity ?

Boitrelle, Florence 27 June 2014 (has links)
Les qualités intrinsèques spermatiques (état de condensation de la chromatine, intégrité de l’ADN, contenu chromosomique, capacités fécondantes..) sont très variables d’un spermatozoïde à l’autre. Le pari aujourd’hui en assistance médicale à la procréation est de relier un aspect morphologique spermatique à ces qualités intrinsèques dans le but de mieux choisir le spermatozoïde vivant à injecter et d’améliorer les taux de grossesse. Depuis 2002, le MSOME (Motile Sperm Organelle Morphology Examination) permet d’observer les spermatozoïdes à fort grossissement, en contraste interférentiel de Nomarski et d’observer des structures qu’on appelle les « vacuoles ». L’injection intra-ovocytaire de spermatozoïdes sélectionnés en MSOME (IMSI) comme non porteurs de vacuoles céphaliques permettrait d’améliorer les taux de grossesses évolutives. Ici, nous avons montré que les vacuoles spermatiques correspondaient à des cratères nucléaires en lien avec une non-condensation chromatinienne (non remplacement des histones au cours de la spermiogenèse). Certaines atypies morphologiques spermatiques sont aussi en lien avec une non-condensation de la chromatine. De plus, spermatozoïdes vacuolés présentent parfois des taux de fragmentation élevés. Aucun lien n’a cependant été retrouvé entre un aspect morphologique spermatique d’une part et un contenu chromosomique ou des capacités fécondantes particulières d’autre part. De ces liens, nous avons pu dégager de nouvelles indications d’IMSI. Ainsi, nous avons avancé dans la description des critères de sélection du spermatozoïde humain vivant donnant le moins de risque d’échec d’implantation embryonnaire et/ou d’anomalies pour la descendance / Intrinsic sperm quality criteria (chromatin condensation, DNA fragmentation, chromosome content, fecundity, etc.) vary from one spermatozoon to another. It is critical to be able to link morphological aspects to these quality criteria, in order to improve the selection of high-quality, live spermatozoa and thus improve pregnancy and delivery rates. Since 2002, motile sperm organelle morphology examination has been used to screen for defects under high magnification and thus select vacuole-free spermatozoa (which are known to be associated with higher pregnancy rates in intracytoplasmic morphologically selected sperm injection (IMSI) programmes). Here, we demonstrate that sperm vacuoles are nuclear concavities associated with chromatin condensation failure (due to a lack of histone replacement during spermiogenesis). A number of other morphological abnormalities were found to be linked to chromatin condensation failure. In some cases, vacuolated spermatozoa were seen to be more DNA-fragmented than vacuole-free ones. In contrast, sperm morphology was not related to chromosomal content or fecundity characteristics. Our observations enabled us to identify new indications for IMSI and refine the criteria for selecting the best spermatozoon: the spermatozoon with the lowest risk of implantation failure or abnormalities in the offspring
2

Polismyndighetens användning av IMSI-catchers : en studie utifrån rätten till respekt för privatlivet och skyddet för den personliga integriteten / The use of IMSI-catchers by The Swedish Police Authority : in relation to the right to respect for private life and the protection of personal integrity

Bränneson Petersson, William January 2019 (has links)
No description available.
3

Encrypting IMSI to improve privacy in 5G Networks

Cobo Jiménez, Enrique January 2017 (has links)
Nowadays, the long-term identifier of a user in a mobile network, namely International Mobile Subscriber Identity or IMSI, is transmitted in clear text over the radiointerface. Given that this interface is used as a shared medium, anyone with a radio transceiver and processing software can thus read such identifier. This fact constitutes a threat to user privacy, considering that the user is traceable by following the presence of the identifier in the network. Moreover, the menace has been known in the literature for the last 25 years, but no countermeasures have been deployed because the severity was judged not to be sufficiently high. However, the current situation is different. One the one hand, the user is made more vulnerable: the needed equipment for catching IMSIs over the radio interface is becoming cheaper, while user-related connected devices are arising in the form of Internet of Things. On the other hand, mobile devices are now computationally more powerful, and the upcoming standardization of 5G represents an opportunity to address such issues. This dissertation presents a proposal to encrypt the IMSI based on Elliptic Curve Integrated Encryption Scheme, a public-key approach in which the long-term subscription identifier is concealed over the radio interface. By doing so, the IMSI is never publicly disclosed, and thus privacy is enhanced. Besides, research was conducted to show the technical feasibility of the proposal. First, the impact of the encrypted identifier on the network was studied. Secondly,the execution time needed for Android devices to perform encryption operations was measured. In both cases, the results were favorable, drawing the conclusion that there are no impediments to the adoption of the presented solution. The Thesis was developed in cooperation with Ericsson AB, Security Research. / Den långsiktiga identifieraren för en användare i ett mobilt nätverk, IMSI (International Mobile Subscriber Identity), överförs i klartext via radiogränssnittet. Med detta gränssnitt som delat medium kan någon med en radiomottagare och mjukvara läsasåna identierare. Detta utgör ett hot mot användarnas personliga integritet med tanke på att användaren kan spåras genom att följa förekomsten av identifierare i nätverket. Dessutom har hotet varit känt under de senaste 25 åren, men inga åtgärder har använts eftersom att risken bedömdes inte vara tillräckligt hög. Däremot är den nuvarande situationen annorlunda. Å ena sidan är användaren mer sårbar: den utrustning som behövs för att fånga IMSI över radiogränssnittet blir billigare medan antalet användarrelaterade anslutna enheter ökar. Å andra sidan kan moderna mobila enheter utföra mycket mer beräkningar, och den kommande standardiseringen av 5G utgör en möjlighet att lösa sådana problem. Rapporten presenterar ett förslag för att kryptera IMSI baserat på ECIES (Elliptic Curve Integrated Encryption Scheme), en asymmetrisk-kryptografi algoritm där den långsiktiga identifieraren är dold över radiogränssnittet. Genom att göra så avslöjas aldrig IMSI, och därmed förbättras den personliga integriteten. Dessutom har forskning bedrivits för att visa den tekniska genomförbarheten avförslaget. Först studerades effekten av den krypterade identifieraren i nätverket. Sedan mättes exekveringstiden som krävs för Android-enheter för att utföra krypteringsoperationer. I båda fallen var resultaten gynnsamma, och därav dras slutsatsen att det inte finns några hinder för antagandet av den presenterade lösningen. Denna rapport framställdes i samarbete med Ericsson AB, Security Research.
4

Morphométrie des vacuoles du spermatozoïde humain : intérêt physiopathologique / Pathophysiological interest of human sperm vacuoles

Gatimel, Nicolas 04 November 2016 (has links)
Depuis plus de 30 ans, de nombreuses publications se sont attachées à expliquer la physiopathologie des anomalies morphologiques du spermatozoïde humain et ont mis en évidence des corrélations entre le pourcentage de formes normales et certaines anomalies fonctionnelles et des relations avec certains facteurs d'exposition. Le caractère physiologique de la plupart des " traits " morphologiques du spermatozoïde humain rend très difficile l'interprétation du spermocytogramme en dehors des syndromes d'anomalies monomorphes. A ces difficultés d'interprétation, viennent se rajouter le manque cruel de fiabilité analytique des techniques actuelles pour l'évaluation de la morphologie du spermatozoïde humain rendant très difficile l'utilisation de seuil décisionnel pour le choix d'une technique d'Assistance Médicale à la Procréation. Cette morphologie est classiquement observée sur lame après coloration (de Schorr le plus souvent). Il a récemment été développé une technique d'observation des spermatozoïdes mobiles associant un contraste interférentiel de Nomarski et un fort grossissement numérique et optique de x6000 au total permettant de mieux déceler certaines anomalies et notamment des vacuoles au niveau de la tête des spermatozoïdes. Cette technique est appelé MSOME (Motile Sperm Organelle MorphologyExamination). L'origine de ces vacuoles reste controversée, sont-elles d'origine nucléaire ou acrosomique ? Certains auteurs ont mis en évidence une relation entre la présence de larges vacuoles et des anomalies de condensation de la chromatine. De plus, beaucoup de questions subsistent quant au réel intérêt diagnostic du MSOME. Au cours d'un premier travail j'ai essayé d'amener un argument supplémentaire à l'origine des vacuoles. J'ai étudié le cas de deux patients atteints de globozoospermie totale (patients porteurs de spermatozoïdes sans acrosome confirmé par microscopie électronique). Au cours de ce travail, outre l'analyse morphométrique des vacuoles avec le MSOME, j'ai utilisé des techniques d'immunofluorescence (lectines PNA et anticorps anti-CD46) pour analyser le statut acrosomique et des techniques TUNEL (terminal deoxynucleotidyltransferase-mediateddUTPnick-end labelling assay) et SCSA (spermchromatin structure assay) pour le statut nucléaire du spermatozoïde. Les deux patients avaient un nombre et une surface vacuolaire (6,3% et 5%) très similaires à celles de 12 témoins fertiles (5%) permettant d'exclure une origine acrosomique de la plupart de ces vacuoles. Je me suis ensuite intéressé à l'impact de la congélation du sperme (très utilisé en pratique clinique) sur l'apparition de ces vacuoles. Après analyse morphométrique précise à l'aide d'un logiciel d'analyse d'image de plus de 2000 spermatozoïdes avant et après congélation (27 individus) je n'ai retrouvé aucune différence statistiquement significative en termes de nombre, surface et position de ces vacuoles entre avant et après congélation. De nombreux auteurs plaident en faveur d'une utilisation en pratique clinique de cette évaluation des vacuoles à fort grossissement sans qu'il n'y ait aucune donnée sur la présence de ces vacuoles dans une population de référence (témoins fertiles). J'ai donc réalisé une analyse morphométrique précise de ces vacuoles dans une population de 50 témoins fertiles. La très grande fréquence de ces vacuoles (95,8 %) dans cette population souligne le caractère physiologique de la plupart d'entre elles. / For over 30 years, many publications have sought to explain the pathophysiology of human sperm morphological abnormalities and showed correlations between the percentage of normal forms and functional defect and some relationships with some exposure factors. The physiological nature of most of the "features" of human sperm morphology makes the interpretation of human sperm morphology very difficult except for monomorphic defects. To these difficulties of interpretation, come to add the lack of analytical reliability of current techniques for assessing human sperm morphology making very difficult the use of threshold of normal forms for the choice of medical treatment of infertile couple in Assisted Reproductive Treatment. Recently a new aspect of sperm morphology, the head vacuoles, has shown to be of interest. The vacuoles can be easily observed using Nomarski interference contrast microscopy at high magnification: ×6000 to 10000 (optical magnification ×1000 associated with digital enhancements that achieves a final magnification up to 6000) even on motile spermatozoa (MSOME: Motile Sperm Organellar Morphology Examination). The origin of these vacuoles raises many questions. Several studies have found a link between chromatin condensation defects and the presence of sperm head vacuoles and clinical interest of MSOME is still somewhat debated. To add new arguments concerning the origin of the sperm-head vacuoles observed under high magnification with interference contrast microscopy, we carried out in two patients with total globozoospermia confirmed using transmission electron microscopy (TEM), a detailed sperm morphometric analysis with MSOME, an acrosomal status analysis (using fluorescent labelling with peanut agglutinin (PNA) lectins and anti-CD46 antibodies) and a nuclear status analysis (using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling assay TUNEL, sperm chromatin structure assay SCSA and aniline blue staining). Our two patients with globozoospermia had relative sperm vacuole areas of 6.3% and 5%, similar to those observed in a reference population of 12 fertile men (5.9%). This study provides further information on the non-acrosomal origin of the sperm-head vacuoles. Since the development of MSOME for observing the cephalic vacuoles at high magnification, no study as yet assessed the effect of cryopreservation on these vacuoles, although sperm freezing-thawing procedures are known to affect sperm quality. In 27 sperm samples from fertile men, morphological analysis at high magnification (·6000) using image analysis software was performed before freezing and after thawing, there was no evidence for any difference in any vacuolar criteria (relative vacuole area, total vacuole area, vacuole area in the anterior, median and basal parts of the head, percentage of spermatozoa with a vacuole area < 6.5% and percentage of spermatozoa with a vacuole area >13%). Freezing-thawing procedures have no effect on human sperm vacuoles. In order to establish reference values concerning sperm vacuoles and to know if the assessment of sperm vacuoles at high magnification can contribute to the explanation of idiopathic infertility, I investigated the number, position and area of sperm head vacuoles using an image analysis software in 50 fertile men and 50 infertile men were within couples who had unexplained infertility and were consulting in our centre. After analysis, the characteristics of sperm head vacuoles (number, area, position) are no different between fertile controls and patients with unexplained infertility.
5

Brave New World Reloaded: Advocating for Basic Constitutional Search Protections to Apply to Cell Phones from Eavesdropping and Tracking by Government and Corporate Entities

Berrios-Ayala, Mark 01 December 2013 (has links)
Imagine a world where someone’s personal information is constantly compromised, where federal government entities AKA Big Brother always knows what anyone is Googling, who an individual is texting, and their emoticons on Twitter. Government entities have been doing this for years; they never cared if they were breaking the law or their moral compass of human dignity. Every day the Federal government blatantly siphons data with programs from the original ECHELON to the new series like PRISM and Xkeyscore so they can keep their tabs on issues that are none of their business; namely, the personal lives of millions. Our allies are taking note; some are learning our bad habits, from Government Communications Headquarters’ (GCHQ) mass shadowing sharing plan to America’s Russian inspiration, SORM. Some countries are following the United States’ poster child pose of a Brave New World like order of global events. Others like Germany are showing their resolve in their disdain for the rise of tyranny. Soon, these new found surveillance troubles will test the resolve of the American Constitution and its nation’s strong love and tradition of liberty. Courts are currently at work to resolve how current concepts of liberty and privacy apply to the current conditions facing the privacy of society. It remains to be determined how liberty will be affected as well; liberty for the United States of America, for the European Union, the Russian Federation and for the people of the World in regards to the extent of privacy in today’s blurred privacy expectations.

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