Histological and immunohistological aspects of the ovarian cycle of the algerian wild sand rat, Psammomys obesus Cretzschmar, 1828.

The sand rat, Psammomys obesus, is largely used as a model for studying several metabolic disorders. In order to perform breeding laboratory conditions, the reproductive function of this species was investigated. Using histological and immunohistochemical techniques, several aspects of the ovaries were studied throughout the sexual cycle. During the ovarian cycle, the different stages of folliculogenesis, from primordial to Graafian follicle, have been shown; the differentiation of both granulosa and theca cells, the formation of the antrum, cumulus oophorus and corona radiate were described. Broken follicles and corpora lutea have been observed, confirming a spontaneous ovulation in isolated females. Steroid activities were analysed using immunohistochemical techniques. Estrogen, androgen and progesterone hormones were visualized in the different compartments of the ovary

Morphometry and immunohistochemistry of follicles growth and steroidogenesis in saharian wild sand rat, Psammomys obesus, ovary.

The sand rat (Psammomys obesus) constitutes a model to study seasonal changes and several metabolic disorders. In order to perform breeding laboratory conditions, the reproductive function of this species living in North Occidental Algerian Sahara was studied. The aim of this work was to investigate the follicular growth changes and the steroidogenic associated aspects. The study was performed using morphometrical and immunohistochemical methods. From primordial to preantral states, the follicle diameter increased progressively from 17-20 mum to 192-225 mum. The preovulatory follicles reached about 500 mum in diameter. Immunoreactivity to progesterone, androstenediol and estradiol, varied in the different parts of the ovary and follicular cells. The progesterone antibody appeared clearly labelled in the theca interna of the growing follicle and increased in the granulosa; the androgen antibody was continuously weak and diffuses in all follicles; the estradiol labelling appeared weak and diffuse in preantral follicles then increased in antral follicles in both theca and granulosa or only in granulosa. In antral follicles, estradiol label was clearly localized in granulosa cells and totally devoid in theca cells. In Psammomys ovary, labels of hormone were diffuse or localized, weak or intense in the theca and or in the granulosa according to the follicle size

Analyse de la contribution des nouvelles routes de la soie dans le renforcement de la coopération entre la chine et les pays de la région du Nord d’Afrique et du Moyen-Orient

China's attempts to interact with the outside world and increase its presence on the international arena are exemplified by the new Silk Road Strategy. In the near future, China's execution of this policy may encounter hurdles. The greatest impediments for Chinese diplomacy are geopolitical conflicts, but internal instability in certain countries and the concern of becoming too reliant on China are also obstacles. The manner in which China handles these obstacles along the Silk Roads will inevitably impact the development of the New Silk Road. In order to prevent connectivity initiatives from devolving into geopolitical games, China asserts that it adheres to the principles of non-interference and win-win cooperation, and it pledges to provide more public goods through initiatives such as the Asian Infrastructure Investment Bank and the Silk Road Fund. In a multipolar world characterized by managed economic diplomacy and global economic governance, China has entered the process of regional and mega-regional economic integration through the Silk Roads and the Economic Belt in order to promote exports, international relations between the various countries along the route in the form of transmission channels, and to establish the principle of global economic cooperation. This article examines trade diplomacy between North African and Middle Eastern nations and analyzes how the New Silk Roads Initiative might transform trade diplomacy between these nations. For this goal, we compiled a sample of thirteen nations for the years 2007 through 2019. Using panel regression, we determined that the program had a significant influence on the trade diplomacy of nations in the North Africa and Middle East area.   Keywords: New Silk Roads, Economic Cooperation, Economic Diplomacy, Panel Regression, North Africa, Middle East JEL Classification: F14 Paper type: Empirical researchLes tentatives de la Chine pour interagir avec le monde extérieur et accroître sa présence sur la scène internationale sont illustrées par la nouvelle initiative de la route de la soie. Dans un avenir proche, l'exécution de cette politique par la Chine pourrait se heurter à des obstacles. Les plus grands obstacles pour la diplomatie chinoise sont les conflits géopolitiques, mais l'instabilité interne de certains pays et la crainte de devenir trop dépendant de la Chine sont également des obstacles. La manière dont la Chine gère ces obstacles le long des Routes de la soie aura inévitablement un impact sur le développement de la Nouvelle route de la soie. Afin d'éviter que les initiatives de connectivité ne se transforment en jeux géopolitiques, la Chine affirme qu'elle adhère aux principes de non-ingérence et de coopération gagnant-gagnant, et elle s'engage à fournir davantage de biens publics par le biais d'initiatives telles que la Banque asiatique d'investissement dans les infrastructures et le Fonds de la route de la soie. Dans un monde multipolaire caractérisé par une diplomatie économique dirigée et une gouvernance économique mondiale, la Chine s'est engagée dans le processus d'intégration économique régionale et méga-régionale par le biais des Routes de la soie et de la Ceinture économique afin de promouvoir les exportations, les relations internationales entre les différents pays le long de la route sous forme de canaux de transmission, et d'établir le principe de la coopération économique mondiale. Cet article examine la diplomatie commerciale entre les nations d'Afrique du Nord et du Moyen-Orient et analyse comment l'initiative des Nouvelles Routes de la Soie pourrait transformer la diplomatie commerciale entre ces nations. Pour ce faire, nous avons compilé un échantillon de treize nations pour les années 2007 à 2019. En utilisant la régression de panel, nous avons déterminé que le programme avait une influence significative sur la diplomatie commerciale des nations de la zone Afrique du Nord et Moyen-Orient.   Mots clés : Nouvelles routes de la soie, Coopération économique, Diplomatie économique, Régression de panel, Afrique du Nord, Moyen-Orient Classification JEL : F14 Type de l’article : Recherche appliqué

Tool and Process Design for Semi-dry Drilling of Steel: An Innovation for Green Manufacturing

The current trend in the metal-cutting industry is to find ways to completely eliminate or drastically reduce cutting fluid use in most machining operations. Recent advances in tool and machine technology have made it possible to perform some machining without cutting fluid use or with minimum quantity lubrication (MQL). Drilling takes a key position in the realization of dry or MQL machining. Economical mass machining of common metals (e.g., tool and construction-grade steels) requires knowledge of the work piece characteristics as well as the optimal machining conditions. In this study we investigated the effects of using MQL in drilling 1020 and 4140 steels using HSS tools with different coatings and geometries. The treatments selected for MQL in this study are commonly used by industry under flood cooling for these materials. A full factorial experiment was conducted, and the regression models for both surface finish and hole size were generated. The regression models were then used in a Pareto optimization study, and the trade-off between surface finish and hole size deviation from the nominal size was reported. The results showed a definite increase in tool life and better or very acceptable surface quality and size of holes drilled when usingMQL compared with flood cooling.ISTC Sponsored Research Program ; HWR05-192Ope

L’impact des nouvelles routes de la soie sur la gouvernance économique dans la région du Moyen-Orient et Afrique du Nord

The strength of China's economy has historically been linked to its openness and connections with the rest of the world. For fifteen centuries, the ancient Silk Road provided a network of roads and sea lanes for the trade of goods and the transfer of knowledge in Europe, the Middle East and Africa. The Silk Road Initiative is an attempt to reconstruct a modern Silk Road in order to, among other reasons, reduce the transportation costs of traded goods. The objective of this paper is to provide an overview of China's international trade with the Middle East and North Africa region and to study the sensitivity of bilateral trade flows between countries along the Belt and Road to distance, economic and demographic masses, and other variables of cultural and political proximity in order to investigate the impact of the new Silk Roads. To do so, we use a gravity model to analyze China's trade flows in relation to countries in the Middle East and North Africa region to those predicted by the model. However, we adopted the panel regression method to analyze the relationship that may exist between economic governance and the New Silk Roads. As a result, we found that the New Silk Roads have only a small effect on country governance.     JEL Classification: F14 Paper type: Empirical researchLa force de l'économie chinoise a été historiquement liée à son ouverture et à ses liens avec le reste du monde. Pendant quinze siècles, l'ancienne route de la soie a fourni un réseau de routes et de voies maritimes pour le commerce des marchandises et le transfert des connaissances avec l'Europe, le Moyen-Orient et l’Afrique. L'initiative « route de la soie » est une tentative de reconstruction d'une route de la soie moderne afin, entre autres raisons, de réduire les coûts de transport des marchandises échangées. L'objectif de cet article est de fournir un panorama du commerce international de la Chine avec la région Moyen-Orient et Afrique du Nord et d'étudier la sensibilité des flux commerciaux bilatéraux entre les pays situés le long de la Ceinture et de la Route à la distance, aux masses économiques et démographiques, ainsi qu’à d’autres variables de proximité culturelle et politique afin d’étudier l’impact des nouvelles routes de la soie. Pour ce faire, nous utilisons un modèle de gravité, afin d'analyser les flux commerciaux de la Chine par rapport aux pays de la région Moyen-Orient et Afrique du nord à ceux prévus par le modèle. Cependant, nous avons adopté la méthode de régression de panel afin d’analyser la relation qui peut exister entre la gouvernance économique et les nouvelles routes de la soie. Par conséquent, nous avons constaté que les nouvelles routes de la soie n’exercent qu’un faible effet sur la gouvernance des pays.     Classification JEL :  F14   Type de l’article : Recherche appliquée

Ethanol Induced Toxicity and Lipid Peroxidation in Pregnant Mice: Protective Effects of Butanolic Extract from Leaves of Chrysanthemum fontanesii, Vitamin E and C

Background: The objective of the present study was to investigate the ability of butanolic extract from leaves of Chrysanthemum fontanesii, vitamin E and C to modulate ethanol-Induced toxicity and oxidation damage in maternal and fetal tissues of mice. Butanolic extract from leaves of Chrysanthemum fontanesii (200 mg/Kg per day), vitamin E (100mg/Kg per day) and C (8.3mg/Kg per day) were administered by gavage to groups of pregnant mice from the 6 th to 17 th day of gestation. A number of animals received plant extract, vitamin E and C, also treated with an oral administration of ethanol (0.02ml/g of 25% v/v absolute ethanol in water per day) in same conditions. On day 18 of gestation, pregnant mice were killed, fetus, placenta, fetal liver, liver, kidneys and brain were removed, homogenised and used for determination of lipid peroxidation (LPO) using TBARS method. Embryotoxicity was assessed by counting the number of live and dead fetus and growth retardation. Results: Severe alterations in all biomarkers were observed after injury with ETOH. ETOH produced significant decreases in fetal weight and significant increases in embryolethality and lipid peroxidation relative to control values. Treatment with Chrysanthemum fontanesii extract, vitamin C and vitamin E resulted in markedly decreased embryolethality and fetal growth retardation, while increased fetal weight were observed. Conclusion: The butanolic extract from leaves of Chrysanthemum fontanesii, vitamin E and C protected against ethanol induce fetal and maternal toxicity as revealed by the decrease in the extent of lipid peroxidation. So that butanolic extract from leaves of Chrysanthemum fontanesii posses in vivo antioxidant properties