Efficacy of ovine artificial insemination at farm level in Tunisia

Les inséminations artificielles des brebis (n=3765) réalisées en contre-saison enregistrées durant 3 années successives chez les éleveurs privés ont été analysées afin de déterminer les facteurs influençant la réussite de l’insémination. Les brebis appartenaient à 13 éleveurs adhérant au programme de contrôle des performances de la Direction de l’Amélioration Génétique de l’Office de l’élevage et des Pâturages. Quatre races autochtones: Sicilo-Sarde (SS), Noire de Thibar (NT), Queue Fine de l’Ouest (QFO) et Barbarine tête noire (BTN) et tête rousse (BTR) ont fait l’objet de cette étude. Après avoir reçu un traitement de synchronisation des chaleurs, ces brebis ont subi une insémination cervicale avec du sperme frais ou refroidi à 15°C environ 55 ± 1 h après le retrait de l'éponge. Notre étude a montré que la fertilité des brebis inséminées en contre saison par la technique IA cervicale variait de 32 à 74 % avec une moyenne de 47,6 ± 9,9 %. L’utilisation de la semence refroidie a réduit significativement (p<0,01) le taux de réussite de l’IA avec 43,8 ± 7,6 % contre 55,9 % ± 9,6 % en utilisant la semence fraiche. Nos résultats ont montré la supériorité de la race SS par rapport aux races à viande Tunisienne. Un effet important de la conduite d’élevage a été décelé, montrant l’importance de la préparation des brebis avant le recours à l’IA. Mots clés : Brebis, Fertilité, Insémination cervicaleThe artificial inseminations of ewes (n = 3765) carried out during spring mating season recorded during 3 successive years at private farms were analyzed in order to determine the factors influencing the results of insemination. Ewes belonged to 13 privet breeders adhering to the program of ovine’s performances control of the Department of Genetic Improvement of the Livestock and Pasture Office, Tunisia. Four indigenous breeds: Sicilo-Sarde (SS), Noire de Thibar (NT), Queue Fine de l'Ouest (QFO) and black head (BTN) and red head (BTR) Barbarine were used. Ewes received an estrus synchronization treatment and AI was performed 55 ± 1hours after PMSG administration with fresh or chilled (at 15° C) semen. Our study showed that the fertility of ewes inseminated in out-of-season by the cervical IA technique varied from 32 to 74 % with an average of 47.6 ± 9.9 %. The use of chilled semen significantly (p <0.01) reduced the success rate of AI with 43.8 ± 7.6 % versus 55.9 % ± 9.6 % using the fresh semen. Our results showed the superiority of the SS breed over the Tunisian meat breeds. An important effect of breeding management was detected, showing the importance of preparing ewes before using AI. Keywords: Cervical insemination, Ewes, Fertilit

Современные методы анализа риска аварий и пожаров на опасных химических объектах

Объектом исследования является фармацевтическое производство, на котором располагается цех с сушильной установкой. Данная установка – аэрофонтанная сушилка, предназначена для сушки пара-нитробензойной кислоты на производстве. Готовый продукт способен образовывать пылевоздушную, взрывоопасную смесь. В случае взрыва это может привести к непоправимым последствиям на предприятии.The object of the study is the pharmaceutical production, on which the drying plant is located. This installation is an aerophone dryer, designed for drying para- nitrobenzoic acid in production. The finished product is capable of forming a dusty, explosive mixture. In the case of an explosion, this can lead to irreparable consequences in the enterprise

Regional research priorities in brain and nervous system disorders

The characteristics of neurological, psychiatric, developmental and substance-use disorders in low-and middle-income countries are unique and the burden that they have will be different from country to country. Many of the differences are explained by the wide variation in population demographics and size, poverty, conflict, culture, land area and quality, and genetics. Neurological, psychiatric, developmental and substance-use disorders that result from, or are worsened by, a lack of adequate nutrition and infectious disease still afflict much of sub-Saharan Africa, although disorders related to increasing longevity, such as stroke, are on the rise. In the Middle East and North Africa, major depressive disorders and post-traumatic stress disorder are a primary concern because of the conflict-ridden environment. Consanguinity is a serious concern that leads to the high prevalence of recessive disorders in the Middle East and North Africa and possibly other regions. The burden of these disorders in Latin American and Asian countries largely surrounds stroke and vascular disease, dementia and lifestyle factors that are influenced by genetics. Although much knowledge has been gained over the past 10 years, the epidemiology of the conditions in low-and middle-income countries still needs more research. Prevention and treatments could be better informed with more longitudinal studies of risk factors. Challenges and opportunities for ameliorating nervous-system disorders can benefit from both local and regional research collaborations. The lack of resources and infrastructure for health-care and related research, both in terms of personnel and equipment, along with the stigma associated with the physical or behavioural manifestations of some disorders have hampered progress in understanding the disease burden and improving brain health. Individual countries, and regions within countries, have specific needs in terms of research priorities.Fil: Ravindranath, Vijayalakshmi. Indian Institute of Science; IndiaFil: Dang, Hoang Minh. Vietnam National University; VietnamFil: Goya, Rodolfo Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Mansour, Hader. University of Pittsburgh; Estados Unidos. Mansoura University; EgiptoFil: Nimgaonkar, Vishwajit L.. University of Pittsburgh; Estados UnidosFil: Russell, Vivienne Ann. University of Cape Town; SudáfricaFil: Xin, Yu. Peking University; Chin

Design, modeling and characterization of bio-nano-robotic systems

Cette thèse porte sur la conception, la modélisation et le prototypage de nanorobots pour des applications en nanomédecine, en biologie et en nanosystèmes. Principalement deux approches ont été proposées. La première approche implique la modélisation multi-échelle (la mécanique quantique, dynamique moléculaire, mécanique continue) couplée aux techniques de réalité virtuelle. La plateforme ainsi développée a permis en premier lieu, la caractérisation biomécanique de différents composants nanorobotiques : nanoressorts à base de protéines et de nanomoteurs moléculaires (ADN, nanotube de carbone, protéines). Le développement de la plateforme a permis ensuite d’assembler d’une manière interactive (retour visuel et retour de force) des structures nanorobotiques, d’optimiser leur structure et de caractériser leur comportement dynamique. Dans la seconde approche, une méthodologie originale de co-prototypage à été développée. Le co-prototypage permet en effet de coupler les expérimentations et les simulations afin d’avoir un modèle réaliste. Ceci permet de mettre à jour les paramètres de simulation et de réajuster le processus de fabrication après optimisation. D’autre part, les simulations permettent d’observer des phénomènes à l’échelle nanométrique qui sont jusque là inaccessibles par expérimentation. Durant ce travail de thèse, j’ai développé des nouvelles structures nanorobotiques : des nanomachines à base d’ADN, un bio-nanoactionneur linéaire ainsi qu’une nanomachine rotative à base de nanotubes de carbone. Quelques uns de ces prototypes ont été fabriqués, optimisés et validés expérimentalement.Nanorobots represent a nanoscale devices where proteins such as DNA, carbon nanotubes could act as motors, mechanical joints, transmission elements, or sensors. When these different components were assembled together they can form nanorobots with multi-degree-of-freedom, able to apply forces and manipulate objects in the nanoscale world. In this work, we investigated the design, assembly, simulation, and prototyping of biological and artificial molecular structures with the goal of implementing their internal nanoscale movements within nanorobotic systems in an optimized manner. The thesis focuses, mainly on two approaches. The first one involves multiscale modeling tools (quantum mechanics, molecular dynamics, continuum mechanics) coupled to virtual reality advanced techniques. In order to design and evaluate the characteristics of molecular robots, we proposed interactive nanophysics-based simulation which permits manipulation of molecules, proteins and engineered materials in molecular dynamics simulations with real-time force feedback and graphical display. The second approach uses a novel co-prototyping methodology. The optimization of engineered nanorobotic device is coupled to experimental measurements and force field modeling algorithms

Guidelines for the Design of Magnetic Nanorobots to Cross the Blood–Brain Barrier

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