bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contribution à l’évaluation des traces de microcystine dissoute et intracellulaire dans les eaux marocaines brutes et traitées
Authors: Khlil Naima , Zidane Fatiha , Naamane Abderrahim , Loutfi Mohamed , Blaghen Mohamed 
Published: September 2012

L’approvisionnement en eau potable de la ville de Casablanca, capitale économique et industrielle du Maroc, est assuré en grande partie par les eaux du réservoir de stockage Tit Mellil alimenté par les eaux traitées provenant de la retenue de barrage Sidi Mohammed Ben Abdellah (SMBA). Or, les eaux brutes du barrage sont souvent affectées par le phénomène d’eutrophisation qui se manifeste par la prolifération des cyanobactéries qui exercent un impact négatif sur la filière de production d’eau potable. En effet, les analyses physico-chimiques, effectuées sur les eaux brutes et traitées, ont permis de faire un diagnostic. Ce dernier a montré que les caractéristiques des eaux brutes favorisent la prolifération de cyanobactéries. Plusieurs genres toxiques ont été identifiés avec Microcystis et Oscillatoria qui sont producteurs de microcystines. L’évaluation des microcystines dans les eaux brutes et traitées a été réalisée par le test colorimétrique d’inhibition de la protéine phosphatase type 2A (PP2A), sur des extraits préconcentrés des fractions dissoutes et des fractions cellulaires avec un seuil de détection de 1 ng•L-1. Les résultats montrent que les microcystines sont présentes dans tous les échantillons d’eaux traitées, prélevés à l’entrée du réservoir de stockage, pendant la période été-automne de 2006 à 2008. Leurs taux en microcystines dissoutes n’excèdent pas 0,075 µg équivalents MC-LR•L-1. Ces valeurs, bien que positives, sont très inférieures au seuil recommandé par l’Organisation Mondiale de Santé, qui est de 1 µg équivalent MC-LR•L-1 d’eau et sont nettement inférieures à celles des eaux brutes, pour la même période, dont les valeurs ont atteint 1,1 µg équivalent MC-LR•L-1 en octobre 2006. Par ailleurs, une évaluation des concentrations en MC dissoute, à la sortie du réservoir de stockage d’eau potable vers le consommateur, a révélé une nette diminution des teneurs, liée probablement aux effets de la chloration appliquée à ces eaux.
Valorisation chimique du kaolin dans le traitement des eaux : préparation de nouveaux coagulants minéraux
Authors: Rakotomaria Etienne , Ratsimba Marie Hanitriniaina , Rakotomamonjy Pierre 
Published: September 2012

La présente étude vise la mise en valeur des matières premières minérales de Madagascar et leurs utilisations pour la satisfaction des besoins locaux importants.Comme la plupart des traitements des eaux à Madagascar font appel au sulfate d’alumine, qui est encore importé, ce travail propose des produits nouveaux à base d’alumine et de silice, permettant de traiter l’eau par coagulation-floculation. L’objectif est de maîtriser le traitement du kaolin par le sulfate d’ammonium et de valoriser les produits obtenus, notamment dans le domaine du traitement des eaux.Les matières premières utilisées sont le kaolin qui existe en grande quantité à Madagascar et le sulfate d’ammonium qui va devenir localement un sous-produit industriel important d’ici quelques années suite à l’installation d’un grand projet d’extraction du nickel et du cobalt à l’est de Madagascar.Les procédés actuels de préparation d’alumine ou des sels d’aluminium à partir de la kaolinite consistent en général en en une activation thermique à haute température (500 à 800 °C) pendant une durée relativement importante, suivie d’une attaque acide. Dans notre procédé, le kaolin est attaqué par le sulfate d’ammonium sans besoin d’activation préalable, à des températures faibles comprises entre 200 et 350 °C pendant deux heures au maximum, pour obtenir des produits contenant du sulfate d’alumine et aussi de la silice. Or il est connu que la silice, ajoutée en faible quantité, est un adjuvant de floculation du sulfate d’alumine, et les résultats de nos recherches ont montré que l’ensemble du produit d’attaque permet, sans séparation, de traiter aussi bien l’eau potable que les eaux usées urbaines et industrielles.Divers essais de coagulation-floculation avec les produits obtenus ont été effectués sur différents types d’eau et les analyses des eaux traitées confirment que certains de ces nouveaux produits peuvent être utilisés pour traiter les eaux par coagulation-floculation.
Modélisation de la dose de coagulant par les systèmes à base d’inférence floue (ANFIS) application à la station de traitement des eaux de Boudouaou (Algérie)
Authors: Heddam Salim , Bermad Abdelmalek , Dechemi Noureddine 
Published: September 2012

La coagulation est l’une des étapes les plus importantes dans le traitement des eaux. La difficulté principale est de déterminer la dose optimale de coagulant à injecter en fonction des caractéristiques de l’eau brute. Un mauvais contrôle de ce procédé peut entraîner une augmentation importante des coûts de fonctionnement et le non-respect des objectifs de qualité en sortie de la station de traitement. Le sulfate d’aluminium (Al2SO4.18H2O) est le réactif coagulant le plus généralement utilisé. La détermination de la dose de coagulant se fait au moyen de l’essai dit de « Jar Test » conduit en laboratoire. Ce type d’approche a le désavantage d’avoir un temps de retard relativement long et ne permet donc pas un contrôle automatique du procédé de coagulation.
Le présent article décrit un modèle neuro flou de type Takagi Sugeno (TK), développé pour la prédiction de la dose de coagulant utilisée lors de la phase de clarification dans la station de traitement des eaux de Boudouaou qui alimente la ville d’Alger en eau potable. Le modèle ANFIS (système d’inférence flou à base de réseaux de neurones adaptatifs), qui combine les techniques floues et neuronales en formant un réseau à apprentissage supervisé, a été appliqué durant la phase de calage et testé en période de validation. Les résultats obtenus par le modèle ANFIS ont été comparés avec ceux obtenus avec un réseau de neurones de type perceptron multicouche (MLP) et un troisième modèle à base de regression linéaire multiple (MLR). Un coefficient de détermination (R2) de l’ordre de 0,92 en période de validation a été obtenu avec le modèle ANFIS, alors que pour le MLP, il est de l’ordre de 0,75, et que pour le modèle MLR, il ne dépasse pas 0,35. Les résultats obtenus sont d’une grande importance pour la gestion de l’installation.
Traitement d'eaux usées urbaines par infiltration-percolation sur sable et sur substrat de coco après un bassin anaérobie de lagune sous climat tropical
Authors: Kone Martine , Bonou Lucien , Koulidiati Jean , Joly Pierre , Sodre Soumaïla , Bouvet Yvette 
Published: September 2012

Au Burkina Faso, l’un des soucis majeurs demeure la gestion des eaux résiduaires dans les villes. Notre objectif a été d’étudier des procédés biologiques alternatifs destinés aux petites et moyennes collectivités et particulièrement adaptés aux conditions climatiques tropicales. Nous avons examiné les performances épuratoires de deux matériaux de filtration que sont le sable et un substrat de coco concassé (fibres de coco), sur des systèmes pilotes recevant des effluents issus d’un bassin anaérobie de lagunage. Les résultats montrent des performances croissantes de 93 % à 95 % sur la DCO (Demande Chimique en Oxygène) et un abattement moyen sur la DBO5 (Demande Biochimique en Oxygène) atteignant 99 %, avec la colonisation progressive du massif de sable par la biomasse. Avec le substrat de coco les rendements moyens sur la DCO passent successivement de 15 % à 51 % lorsque les charges hydrauliques varient de 20 à 60 L•m-2•j-1, du fait de l’extraction de composés phénoliques du substrat. Cependant, il présente la même efficacité que le sable pour l’élimination de la pollution biodégradable.
Les rendements en azote Kjeldahl sont de 75 % et 84 % pour le substrat de coco et le sable respectivement, alors que le filtrat issu du substrat de coco n’a donné que 7 mg•L-1 en moyenne de nitrates. Dans le même temps, les concentrations en nitrates atteignent 40 mg•L-1 pour le massif de sable. Ce comportement du substrat de coco pourrait être attribué à la formation de complexes entre composés azotés et les tanins issus de ce matériau.
Production of 3‐hydroxypropionic acid from glycerol by recombinant Klebsiella pneumoniae ΔdhaTΔyqhD which can produce vitamin B12 naturally
Authors: Ashok Somasundar , Sankaranarayanan Mugesh , Ko Yeounjoo , Jae Kyeung‐Eun , Ainala Satish Kumar , Kumar Vinod , Park Sunghoon 
Published: September 2012

Abstract3‐Hydroxypropionic acid (3‐HP) is an important platform chemical that can be used to synthesize a range of chemical compounds. A previous study demonstrated that recombinant Escherichia coli stains can produce 3‐HP from glycerol in the presence of vitamin B12 (coenzyme B12), when overexpressed with a coenzyme B12‐dependent glycerol dehydratase (DhaB) and an aldehyde dehydrogenase. The present study examined the production of 3‐HP in recombinant Klebsiella pneumoniae strains, which naturally synthesizes vitamin B12 and does not require supplementation of the expensive vitamin. The NAD+‐dependent gamma‐glutamyl‐gamma‐aminobutyraldehyde dehydrogenase (PuuC) of K. pneumoniae alone or with its DhaB was overexpressed homologously, and two major oxidoreductases, DhaT and YqhD, were disrupted. Without vitamin B12 addition, the recombinant K. pneumoniae ΔdhaTΔyqhD overexpressing PuuC could produce ∼3.8 g/L 3‐HP in 12 h of flask culture. However, this was possible only under the appropriate aeration conditions; 1,3‐propanediol (1,3‐PDO) (instead of 3‐HP) was mainly produced when aeration was insufficient, whereas a very small amount of both 3‐HP and 1,3‐PDO were produced when aeration was too high. The production of a small amount of 3‐HP under improper aeration conditions was attributed to either slow NAD+ regeneration (under low aeration) or reduced vitamin B12 synthesis (under high aeration). In a glycerol fed‐batch bioreactor experiment under a constant DO of 5%, the strain, K. pneumoniae ΔdhaTΔyqhD, overexpressing both PuuC and DhaB could produce >28 g/L 3‐HP in 48 h with a yield of >40% on glycerol. Only small amount of 3‐HP was produced when cultivation was carried out at a constant aeration of 1 vvm or constant 10% DO. These results show that K. pneumoniae is potentially useful for the production of 3‐HP in an economical culture medium that does not require vitamin B12. The results also suggest that the aeration conditions should be optimized carefully for the efficient production of 3‐HP while using this strain. Biotechnol. Bioeng. 2013; 110: 511–524. © 2012 Wiley Periodicals, Inc.
The Cochrane Library and procedural pain in children: an overview of reviews
Authors: Curtis Sarah , Wingert Aireen , Ali Samina 
Published: September 2012

AbstractBackgroundProcedural pain in children is highly prevalent, a major source of pain, stress and anxiety, and can have negative short‐ and long‐term effects. Research addressing effective pain management strategies is complex, presenting challenges for clinically relevant synthesis.ObjectiveTo summarize Cochrane reviews assessing the effects of various interventions used for pain in non‐neonatal children undergoing painful medical procedures.MethodsThe Cochrane Database of Systematic Reviews was systematically searched for reviews of interventions for pain in children outside of the neonatal period, undergoing painful medical procedures. The type of data to be extracted was determined a priori, and a single author performed data extraction. The Cochrane Library was searched using the terms ‘procedural pain’ and ‘procedures’. Reviews examining acute procedural pain in older infants, children and adolescents were included. Interventions included topical anaesthetics (eutectic mixture of local anaesthetics and amethocaine), sweet tasting substances, cognitive therapy, behavioural therapy and combined cognitive‐behavioural therapy(CBT). Data on self‐reported, behavioural and observer pain intensity and pain distress were extracted.Main resultsFour systematic reviews were included in the overview. There was evidence that self‐reported pain [risk ratio (RR) 0.63; 95% confidence interval (CI) 0.45–0.87], behavioural measures of pain (RR 0.71; 95% CI 0.52–0.96) and all pain scales combined (RR 0.69; 95% CI 0.55–0.87) were significantly less with amethocaine than with eutectic mixture of local anaesthetics. Results of trials of other interventions are reported in this article but heterogeneity of the combined effects is high.Authors' conclusionsAmethocaine provides superior pain relief when compared with eutectic mixture of local anaesthetics for the procedure of intravenous cannulation. From the data contained in this overview, there is no current evidence of benefit supporting the use of 12% sucrose for older infants and toddlers or sweet gum for toddlers undergoing needle pain. Potentially efficacious nonpharmacological interventions may include distraction, hypnosis, combined cognitive‐behavioural interventions, non‐nutritive sucking and video distraction; however, further research is required as results are mixed. An integrated approach using multiple modalities encompassing both the physiological and psychological aspects of pain is compelling and warrants further study in paediatrics. Copyright © 2012 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. The Cochrane Collaboration
Tonic Sympathetic Nervous System Inhibition of Insulin Secretion Is Diminished in Obese Zucker Rats
Authors: Lee Hyunju Choi , Curry Donald L. , Stern Judith S. 
Published: September 2012

AbstractIt has long been known that the central nervous system (CNS) directly affects pancreatic insulin release. This study was undertaken to determine the effect of the CNS on pancreatic insulin release in three‐month‐old female lean (Fa/Fa) and hyperinsulinemic obese (fa/fa) Zucker rats. Chloral hydrate (400 mg/kg) was used as the anesthetic agent. The in situ brain‐pancreas perfusion model with intact pancreatic innervation was used in this investigation.The study measured insulin secretion in response to a 60‐minute glucose stimulus (200 mg/dl). CNS‐intact and CNS‐functionally ablated obese and lean rats were used. During the 60‐minute perfusion period significantly more insulin was released by pancreata from obese rats compared to those from lean rats. In lean rats, about twice as much insulin was released by pancreata from CNS‐ablated rats than from CNS‐intact rats (P < 0.05), demonstrating a CNS tonic inhibition of insulin secretion. In obese rats, there was no significant difference in insulin released by the pancreata of the CNS‐intact and CNS‐ablated rats. To determine if there was a masking effect of predominant PNS activity over the SNS in the CNS‐intact obese rats, bilateral vagotomy was performed in a group of otherwise CNS‐intact obese rats prior to the onset of perfusion. Tonic inhibition was still not observed in the CNS‐vagotomized obese rats.In conclusion, hypersecretion of insulin in obese rats is partially due to diminished tonic sympathetic nervous system inhibition of insulin release. These results provide additional evidence regarding abnormal CNS control of insulin secretion in obese Zucker rats.
Treatment of Obese Female and Male SHHF/Mcc‐facp Rats with Antihypertensive Drugs, Nifedipine and Enalapril: Effects on Body Weight, Fat Distribution, Insulin Resistance and Systolic Pressure
Authors: Radin M. Judith , Chu Ying Yueh , Hoepf Toni M. , McCune Sylvia A. 
Published: September 2012

AbstractLittle is known about the effects of common antihypertensive drugs in obese, insulin‐resistant females. Nine‐month‐old obese female SHHF/Mcc‐fncp rats that received either nifedipine, a calcium channel antagonist, or enalapril, an angiotensin‐converting‐enzyme inhibitor, for three months were compared with untreated SHHF/Mcc‐facp rats (controls). After one month, nifedipine significantly decreased body weight in obese females compared to either enalapril or controls. After three months of treatment, total, abdominal, and subcutaneous fat masses were decreased in obese females given nifedipine compared to either enalapril or controls. Enalapril treatment was associated with a redistribution of fat mass from abdominal to subcutaneous depots. Nifedipine reduced plasma triglyceride and fasting glucose levels and improved insulin response to an oral glucose load in obese females, whereas enalapril did not appear to affect glycemic control. Systolic pressure was not significantly decreased until after two months of treatment with nifedipine or three months of treatment with enalapril in obese females and may have coincided with improvement in insulin‐resistance. Similarly, plasma atrial natriuretic peptide concentrations were significantly lower in obese females given nifedipine. To determine how obese males responded to a calcium channel antagonist, six‐month‐old obese male SHHF/Mcc‐facp rats were treated for three months with either nifedipine or placebo (controls). Nifedipine‐treated obese males showed a mild but significant decrease in weight gain that was due to a decrease in fat deposition in both subcutaneous and abdominal depots and systolic blood pressure was significantly reduced after one month of treatment. Nifedipine did not affect other plasma biochemical parameters in obese males. In conclusion, nifedipine improved systolic pressure and glycemic control in obese female SHHI;/Mcc‐facp rats, effects that may be associated with a marked loss in body weight and fat mass and improved lipid metabolism. Nifedipine‐treated obese males exhibited only a diminished weight gain that was not associated with changes in diabetic characteristics.
Effects of Dexamethasone on Primarily Cultured Newly Differentiated Rat Adipocytes from Different Adipose Tissue Regions
Authors: Yang Shumin , Xu Xuefan , Bjömrntorp Per 
Published: September 2012

AbstractThe effects of dexamethasone (dex) on newly differentiated adipocytes in primary culture derived from mesenteric, retroperitoneal, epididymal, and inguinal subcutaneous adipose tissues of male rats were studied. The degree of differentiation was similar in these adipose precursor cells derived from different regions as assessed by lipoprotein lipase (LPL) activity, an early marker of adipocyte differentiation. LPL activity was increased by addition of dex, and no differences in degree of activation were observed in cells from different adipose tissue regions. Development of both basal and isoproterenol‐stimulated lipolysis was also similar in adipose precursor cells from different adipose tissue regions. Dex addition enhanced the isoproterenol‐stimulated lipolysis with no regional differences. Studies of binding of [3H]‐dex showed no regional differences in either binding affinity or maximal binding capacity.It is concluded that dex stimulates both LPL activity and lipolytic activity in newly differentiated rat adipocytes in primary culture. This seems, however, not to vary in magnitude in cells obtained from different adipose tissue regions. This might be due to the apparent similarity of number and affinity of glucocorticoid binding sites. Regional variations in glucocorticoid regulated LPL and lipolytic activity in adipose tissue might therefore not be due to inherent differences between adipocytes.
Time‐Dependent Effects of Progressive Gamma ‐Linolenate Feeding on Hyperphagia, Weight Gain, and Erythrocyte Fatty Acid Composition During Growth of Zucker Obese Rats
Authors: Thurmond Debbie C. , Tang Anna B. , Nakamura Manabu T. , Stern Judith S. , Phinney Stephen D. 
Published: September 2012

AbstractObese Zucker rats (fa/fa) have low levels of arachidonic acid (AA) in liver phospholipids (PL). We have previously shown that a 70% gamma‐linolenate concentrate (GLA; an AA intermediate) fed at a fixed dose (0.07 g/day) normalized hepatic PL AA and reduced weight gain selectively in the obese animals. In a follow‐up study, 16 obese (fa/fa) and 16 lean (Fa/Fa) 4‐week‐old male rats were randomized into 4 groups of 8 each and gavaged daily with soybean oil (SOY) containing 55% 18:2ω6 (an AA precursor) or GLA, using a progressive dose (≤ 5% of total calories) based on body weight. A defined diet with 11% of energy as SOY was fed ad libitum for 60 days. GLA obese had lower body weight (p<0.0001) and 60‐day cumulative food intake (p<0.05) compared to SOY obese, but neither parameter differed between the lean groups. For the last twenty days cumulative food intake was identical for GLA obese and SOY lean, whereas SOY obese consumed 18% more (p<0.05). Thus the progressive dose of GLA selectively suppressed hyperphagia in obese Zucker rats. Erythrocytes collected at 15‐day intervals showed parallel increases in AA in both genotypes over time, suggesting normal AA availability during rapid growth. Thus, the reduced PL AA in the livers from the obese rats probably reflects impaired distribution in selected tissues rather than reduced hepatic production. Due to the potential health risks of enriching tissue lipids with AA, great caution is advised in considering GLA as therapy for human obesity.
Feeding Response of Rats to No‐Fat and High‐Fat Cakes
Authors: Sclafani Anthony , Weiss Kerri , Cardieri Catherine , Ackroff Karen 
Published: September 2012

AbstractThe nutritional effects of high‐fat diets have been extensively studied in laboratory animals, but as yet few experiments have examined the feeding response of animals to newly developed fat substitutes. The present study used commercially available no‐fat (0% fat, 92% carbohydrate) and high‐fat (41% fat, 54% carbohydrate) cake to determine the effects of fat substitutes on food preference and caloric intake in rats. The first experiment showed that nondeprived rats found the high‐fat and no‐fat cakes equally palatable and highly preferred to lab chow. Food deprived rats, however, preferred the high‐fat cake to the no‐fat cake, which may be related to its higher caloric density. In the second experiment, rats fed high‐fat cake, in addition to chow, for 30 days consumed more calories and gained more weight than did rats fed no‐fat cake and chow. The no‐fat cake group, however, overate and gained more weight than chow‐only controls. The hyperphagic response to the no‐fat cake can be attributed to its carbohydrate content, moisture, and high palatability. Thus, removing fat from the cake reduced, but did not eliminate, its obesity‐promoting effect. Obviously, low‐fat foods must be consumed in moderation if used for weight control.
Effect of Ethnicity and Geographical Location on Body Weight, Dietary Restraint, and Abnormal Eating Attitudes
Authors: Wing Rena R. , Adams‐Campbell Lucile L. , Marcus Marsha D. , Janney Carol A. 
Published: September 2012

AbstractPrevious studies have examined the effect of ethnicity on obesity, concerns about shape and weight, and attitudes about eating. We hypothesized that geographical location would also influence these variables, and that students growing up in the northern part of the United States and attending northern colleges would differ from students from the South. To examine this, we studied a random sample of 275 African‐Americans (AA) and 224 white college students in the entering class of two northern colleges (University of Pittsburgh or University of Massachusetts) or two southern colleges (Augusta or Paine College). All subjects were weighed and completed the Revised Restraint Scale and the EAT‐26. AA women were heavier than white women, with no differences due to geographical location. Despite being thinner, white women reported more dietary restraint than AA women. This difference between AA and white women was apparent in both northern and southern college students. In contrast, geographical location was the strongest determinant of bulimic attitudes; both men and women at northern colleges reported higher bulimia scores than those at southern schools. Thus ethnicity appears to be a major determinant of body weight and attitudes about shape and dieting, whereas geographical location appears to exert greater influence on bulimic attitudes.