Bilan hydrologique et envasement du barrage Saboun (Maroc)

La présente étude s'inscrit dans le cadre d'un programme de recherche sur la gestion des lacs et barrages collinaires en zone méditerranéenne HYDROMED. Elle a pour objectif le suivi hydrologique et la sédimentation du barrage collinaire Saboun, situé dans la zone de Tanger au Nord-Ouest du Maroc. Un dispositif hydro-pluviométrique automatique a été installé à ce sujet depuis novembre1997. Il a permis le suivi du bilan en eau de la retenue et l'analyse de son fonctionnement hydrologique. Parallèlement, une étude de la bathymétrie par sondage ponctuel a montré que le taux de sédimentation est de l'ordre de 2% par an. Cette perte en eau de la capacité totale de la retenue est une conséquence directe d'une forte dégradation des sols du bassin versant estimée à 115 T/ha/an.It is proposed that many Mediterranean countries could make better use of their water resources by constructing small hill reservoirs. Since 1980, Morocco has built more than 158 small dams in order to meet the requirements of rural population water use. Due to both environmental degradation and bad management, these small infrastructures are now in a critical situation. Furthermore, pollution and siltation, resulting in a deterioration of water quality and a reduction of water capacity, are problems at these sites.The present study is part of the HYDROMED research program on the hydrological balance of small dams in the Mediterranean area. Its objective is the monitoring of hydrological balance and siltation of a small dam, Saboun, located in Tangier in Northwest Morocco. A remote hydrological station was installed in November 1997. This station allowed the examination of the dam water balance and analyses of its hydrological function.The analyses of water balance demonstrated that the volume of water stored in the Saboun reservoir increased rapidly in November 1997, and was then followed by a progressive decrease. The load factor varied from 1.9 in 1997/98 to approximately 2 times the current capacity of reservoir, to only 0.3 in the following year 1998/99. These results show that even for a short hydrological period (2 years), the hydrological balance of the Saboun reservoir varied greatly as a result of the irregularity of its hydrological parameters. The essential reasons for this variability were the rainfall characteristics that control the runoff from the watershed and bad management practices.In addition, a bathymetric survey was carried out by a punctual method to estimate the rate of dam siltation and sedimentation from the watershed. The results of this control demonstrated that the dam siltation rate was about 2 % per year. This loss of total water retention capacity of the dam is the consequence of high specific soil degradation of the watershed. The rate of sediment delivered from watershed and deposited in the reservoir was estimated at 37 T/ha/year. The total soil erosion for watershed was estimated at 115 T/ha/year by integrating both the sediment evacuated at the time of dam overflow and the sediment deposited in stream flow. This erosion, which comes essentially from cultivated soil (95 % of the watershed surface), may have serious effects on the hydrological balance of the dam, particularly by reducing the reservoir capacity of the dam, and on the reservoir water quality

Ультразвуковой контроль качества заготовок в условиях металлургического предприятия

Целью работы является изучение возможности использования неразрушающего контроля качества металлопродукции с помощью ультразвуковой установки в условиях современного металлургического предприятия. Использование эхо–импульсного метода для испытания заготовок сечением 150х150 мм позволяет достаточно хорошо выявлять дефекты типа шлаковых включений, усадочной раковины, внутренних трещин и разрывов, расслоений. Анализ результатов ультразвукового контроля позволяет оценить уровень технологии производства и качества проката, определить ряд технических и организационных мер, обеспечивающих конкурентоспособность продукции.Метою роботи є вивчення можливості використання неруйнівного контролю якості металопродукції за допомогою ультразвукової установки в умовах сучасного металургійного підприємства. Використано ехо–імпульсний метод для контролю якості заготовок перетином 150х150 мм, що дозволяє достатньо надійно виявляти дефекти типу шлакових включень, усадкової раковини, внутрішніх тріщин і розривів, розшарувань. Аналіз результатів ультразвукового контролю дозволяє оцінити рівень технології виробництва і якості прокату, визначити ряд технічних і організаційних заходів, що забезпечують конкурентоспроможність продукції.The work purpose of not destroying quality assurance application possibility studying of metal products by means of ultrasonic apparatus in the conditions of the modern metallurgical enterprise. Application of an echo-impulse method for test of billet with the section 150х150 mm allows to reveal well enough defects of slag inclusions type, a pipe, internal cracks and ruptures, stratifications. The analysis of results of the ultrasonic control allows to estimate a technological level of manufacture and quality of rolled metal, to define a number of the technical and organizational measures providing competitiveness of production

Screening and identification of lactic acid bacteria isolated from sorghum silage processes in west Algeria

The lactic acid bacteria (LAB) isolated from sorghum (Sorghum bicolor. L.) silage were identified during different periods of evolution of sorghum silage in west Algeria. Morphological, physiological, biochemical and technological techniques were used to characterize lactic acid bacteria isolates. A total number of 27 representatives of lactic acid bacterial strains were retained and among them four dominant genus were identified as Lactobacillus (44%), Lactococcus (14.81%), Weissella (29.62%) and Leuconostoc (11.11%). The representative species identified were Lactobacillus brevis (25%), Lactobacillus pentosus (3.7%), Lactobacillus manihotivorans (11.11%), and Lactobacillus fermentum (3.7%). Lactococcus lactis subsp. lactis biovar. diacetylactis (14.81%), Weissella cibaria (7.2%), Weissella minor (11.11%), Weissella soli (3.7%), Weissella viridescense (7.2%) and Leuconostoc mesenteroides subsp. mesenteroides (11.11%). Only two strains of lactic acid bacteria were amylolytic. These results will enable future research on the relationship between LAB species and silage fermentation quality.Keywords: Lactic acid bacteria, identification, silage, sorghum, evolution, amylolytic, technology, speciesAfrican Journal of Biotechnology Vol. 12(14), pp. 1703-170

Maternal Lipids as Strong Determinants of Fetal Environment and Growth in Pregnancies With Gestational Diabetes Mellitus

OBJECTIVE—To determine the contribution of maternal glucose and lipids to intrauterine metabolic environment and fetal growth in pregnancies with gestational diabetes mellitus (GDM)

A novel approach to differentiate rat embryonic stem cells in vitro reveals a role for RNF12 in activation of X chromosome inactivation

textabstractX chromosome inactivation (XCI) is a mammalian specific, developmentally regulated process relying on several mechanisms including antisense transcription, non-coding RNA-mediated silencing, and recruitment of chromatin remodeling complexes. In vitro modeling of XCI, through differentiation of embryonic stem cells (ESCs), provides a powerful tool to study the dynamics of XCI, overcoming the need for embryos, and facilitating genetic modification of key regulatory players. However, to date, robust initiation of XCI in vitro has been mostly limited to mouse pluripotent stem cells. Here, we adapted existing protocols to establish a novel monolayer differentiation protocol for rat ESCs to study XCI. We show that differentiating rat ESCs properly downregulate pluripotency factor genes, and present female specific Xist RNA accumulation and silencing of X-linked genes. We also demonstrate that RNF12 seems to be an important player in regulation of initiation of XCI in rat, acting as an Xist activator. Our work provides the basis to investigate the mechanisms directing the XCI process in a model organism different from the mouse

Some Biological Activities of Malaysian Leech Saliva Extract

Leeches were fed on the phagostimulatory solution through parafilm membrane. The satiated leeches were forced to regurgitate the solution by soaking them in an ice-container. The anticoagulant activity was ascertained using thrombin time assay (TT). The result revealed that the saliva concentration which increases TT by 100% (IC100) is 43.205µg/ml plasma. The antimicrobial activity of the saliva was tested against several bacterial spp. (E.coli, P.aeruginosa, B.cereus, Sal.typhi and S.aureus)  and fungi spp. (C.albicans and C.neoformans). It was found that saliva has an inhibition activity against Sal.typhi (minimal inhibitory concentration MIC 78.253µg/ml), S.aureus (MIC 78.253µg/ml) and E.coli (MIC 121.256µg/ml). ABSTRAK: Pacat-pacat diberi makan larutan phagostimulatory menerusi membran parafilem. Pacat-pacat yang kekenyangan itu dipaksa memuntahkan larutan tersebut dengan direndam di dalam bekas berisi ais. Aktiviti antigumpal ditentukan menggunakan cerakin masa trombin (TT). Keputusan menunjukkan kepekatan air liur pacat menyebabkan pertambahan TT sebanyak 100% (IC100) iaitu 43.205µg/ml plasma. Aktiviti antimikrob air liur telah diuji dengan pelbagai jenis bakteria (E.coli, P.aeruginosa, B.cereus, Sal.typhi dan S.aureus) dan pelbagai jenis kulat (C.albicans and C.neoformans). Didapati air liur menghasilkan aktiviti perencatan terhadap Sal.typhi (kepekatan perencat minima (Minimal inhibitory concentration - MIC) 78.253µg/ml), S.aureus (MIC 78.253µg/ml) dan E.coli (MIC 121.256µg/ml)

BLM helicase suppresses recombination at G-quadruplex motifs in transcribed genes

Bloom syndrome is a cancer predisposition disorder caused by mutations in the BLM helicase gene. Cells from persons with Bloom syndrome exhibit striking genomic instability characterized by excessive sister chromatid exchange events (SCEs). We applied single-cell DNA template strand sequencing (Strand-seq) to map the genomic locations of SCEs. Our results show that in the absence of BLM, SCEs in human and murine cells do not occur randomly throughout the genome but are strikingly enriched at coding regions, specifically at sites of guanine quadruplex (G4) motifs in transcribed genes. We propose that BLM protects against genome instability by suppressing recombination at sites of G4 structures, particularly in transcribed regions of the genome

Assessment of acute and sub-acute toxicity of olive pomace in female Wistar rats

Objective: Olive Pomace (OP) is considered to be a rich source of phenolic compounds. Recently many researches showed a broad biological activity of this by-product of the olive oil production process in addition to their emergence as value-added materials with potential applications in the pharmaceutical, food, and nutraceutical industries. The present study is aimed to evaluate in vivo toxicological activities of OP. Materials and Methods: The qualitative phytochemical analysis aims to determine the key phytoconstituents found in OP. For the in vivo study, two types of tests are performed: acute and 28-day repeated oral toxicity studies in Wistar rats for evaluation of hematological, biochemical, and histological parameters. Results: The qualitative phytochemical analysis has revealed the presence of polyphenols, flavonoids, tannins, saponins, quinones, anthraquinones, terpenoids, and compounds reduced in our methanol extract of OP. In acute oral toxicity, no treatment-related death or toxic signs are observed in female rats for 14 days in 200, 2000, 3000, and 5000 mg/kg doses, besides LD50 value is found to be up to 2000 mg/kg bodyweight. As for the Globally Harmonized System of Classification and Labelling of Chemicals. 28-days sub-acute toxicity study is carried in female rats at four dose levels (3.12, 31.25, 125 and 500 mg/kg), no changes in observation related death and toxic signs when compared with control. The hematological and biochemical investigation shows a significant change (p>0.05) in the high-level doses (500 mg/kg). Conclusions: According to the findings of this study, OP extract has the potential to be used to generate new anti-cancer and antioxidant additives for pharmaceutical and food manufacturing. Long-term in vivo toxicological tests should also be conducted to determine a safe dosage of OP extract