Sand drifting on road networks in the region of the Lower Algerian Sahara is one of the main problems for the sector. Machines are repeatedly deployed to overcome this phenomenon. The long experience acquired while dealing with the removal of sand from roads pushed us to focus on obstacles called "Draas". The purpose of this study is to perform an optimization of these special protective structures called “Draas”, using a reduced physical model. Model tests were performed in flow channel. The principle of modeling the wind transport using a reduced model is to simulate the wind using a liquid stream while respecting the laws of hydraulic and sedimentological similarity. The results obtained are extrapolated to make a normal size prototype.
The category of expectation constitutes an important element of reflection in many scientific disciplines focusing on man. it is treated in both the categories of expectations inscribed in large social projects (e.g. of utopian nature) and individual expectations which build human daily routine. The article is divided into two parts. in the first, the issues of interpersonal expectations, analysed in the perspective of social psychology and sociology, will be undertaken. what will be explored here are the problems of defining the notion of expectation and the problems of expectations at school, which will be exemplified by the pygmalion effect. The first part is completed with some considerations on the meaning of expectation in sociology, the role of expectations in interaction, and the relations between expecting and social order.
In the second part, the author focuses on the issues of expectations inscribed in utopian projects (“great expectations”). pedagogical utopias and relations between utopias and popularization of normative (formal) or informal pedagogies are subjected to analysis. The author makes here some references to the concept of post-materialistic society, attempting to elicit relations between this type of society and popularization of nonformal pedagogies.
I n t r o d u c t i o n: Interactions between oral microbiota and systemic diseases have been suggested. We aimed to examine the composition of oral microbiota with reference to antioxidative defense and its correlation with clinical state in Crohn’s disease (CD) in comparison to ulcerative colitis (UC).
Ma t e r i a l s a n d Me t h o d s: Smears were taken from the buccal and tongue mucosa of patients with CD, UC and controls, and cultured with classical microbiology methods. Bacterial colonies were identified using matrix-assisted laser desorption/ionization (MALDI) with a time-of-flight analyzer (TOF). Blood morphology and C-reactive protein (CRP) were analyzed in the hospital laboratory. Antioxidative defense potential (FRAP) was determined using spectrophotometry in saliva and serum.
R e s u l t s: Oral microbiota in CD patients were characterized by lower diversity in terms of the isolated bacteria species compared to UC and this correlated with reduced FRAP in the oral cavity and intensified systemic infl ammation. Oral microbiota composition in CD did not depend on the applied treatment. In CD patients, a negative correlation was observed between the FRAP value in saliva and serum and the CRP value in serum. Individual differences in the composition of oral microbiota suggest that different bacteria species may be involved in the induction of oxidative stress associated with a weakening of antioxidative defense in the oral cavity, manifested by ongoing systemic inflammation.
C o n c l u s i o n s: Analysis of both the state of the microbiota and antioxidative defense of the oral cavity, as well as their referencing to systemic inflammation may potentially prove helpful in routine diagnostic applications and in aiding a better understanding of CD and UC pathogenesis associated with oral microbiota.
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