134 research outputs found

    Traitements d'effluents issus de l'industrie de la pêche par un procédé de coagulation/floculation

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    La présente étude porte sur le traitement physico-chimique d'un effluent industriel chargé d'encre de seiche issu de l'industrie de conditionnement des produits de la pêche. Différentes combinaisons de coagulant -floculant ont été étudiées. Le sulfate d'aluminium (SA), divers polyélectrolytes et certains adjuvants pulvérulents ont été utilisés. L'efficacité du traitement par coagulation-floculation a été analysée en suivant l'évolution de la turbidité et de la DCO résiduelle du surnageant.Les résultats de cette étude ont révélé qu'à pH 6-7, l'addition de SA à une concentration supérieure à 1000 mg.l-1 entraîne la coagulation des particules d'encre de seiche. L'addition d'un polyélectrolyte en association avec le SA permet de réduire la concentration requise en SA à environ 300 mg.l-1, tout en améliorant l'efficacité du processus de coagulation-floculation. Le recours à un adjuvant pulvérulent en combinaison avec le SA et un polyélectrolyte accroît notablement les performances du traitement et permet d'obtenir un effluent ayant une turbidité résiduelle de 7 NTU.The aim of this work was to compare the efficiency of a coagulation-flocculation process using different systems individually or in combination. The waste water used was an industrial cuttlefish effluent principally composed of colloidal particles from the cuttlefish. The initial turbidity and chemical oxygen demand were approximately 700 NTU and 22,000 mg×L-1 respectively. Two parameters were used to assess the process efficiency: the residual turbidity and the chemical oxygen demand (COD) of the supernatant.Three systems were investigated: aluminium sulphate (SA), polyelectrolytes and a ternary combination of SA-polyelectrolyte and colloidal microparticle adjuvant. Results demonstrated that at pH 6-7, SA caused some coagulation of the suspension, but the dosage required (about 1000 mg×L-1) far exceeded those conventionally used in water treatment. As a consequence, an appreciable amount of SA, which was above the authorised limits, remained in the supernatant. Indeed, adsorption isotherm measurements revealed that at pH 6.5-7 the residual proportion of SA attained was about 20%. The addition of polyelectrolytes in combination with SA allowed reduction of the SA dosage to 150 mg×L-1. Amongst the polymers tested, the cationic polymer was the most efficient. The ability to bring about flocculation was positively related to the molecular weight, which is in agreement with a bridging flocculation mechanism. Starch, a natural, low-cost polymer was also an efficient flocculent even though it is a non-charged polymer. The ability of starch to bring about a flocculation action was explained by its relatively low solubility, which leads to some aggregation of macromolecular chains that act as anchoring sites for the coagulated ink particles. With this system, a double treatment in the presence of 150 mg×L-1 SA and 25 mg×L-1 polydiallyldimethylammonium chloride (PDMAC) or starch lead to a supernatant with a turbidity and COD of 150 NTU and 5500 mg×L-1 respectively.The third part of our study was concerned with the effect of the addition of an insoluble microparticle adjuvant in combination with SA and polyelectrolytes. Different components were investigated, but among them only colloidal silica and MgO bring about a significant enhancement of the flocculation process. This effect was explained by a bridging mechanism in which the adjuvant microparticles act as sites that favour the anchoring of the coagulated ink particles. Using a triple treatment in the presence of 150 mg×L-1 SA, 25 mg×L-1 PDMAC and 0.75 g×L-1 MgO removed about 95 % of the ink particles. The supernatant obtained was characterised by a low turbidity value (about 7 NTU) and a COD value about 2000 mg×L-1

    Preliminary study of haplotypes linked to the rare cystic fibrosis E1104X mutation

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    The analysis of some extra- and intragenic markers within or closely linked to the cystic fibrosis transmembrane regulator (CFTR) gene is useful as a molecular method in clinical linkage analysis. Indeed, knowing that the molecular basis of cystic fibrosis (CF) is highly heterogeneous in our population, the study of haplotype association with normal and CF chromosomes could be very helpful in cases where one or both mutations remain unidentified. In this study, we analysed with PCR-RFLP and capillary electrophoresis some extra (pJ3.11, KM19 and XV2C) and intragenic (IVS8CA, IVS17bTA and IVS17bCA) polymorphic markers in 50 normal and 10 Tunisian patients carrying the rare E1104X mutation in order to determine the haplotype associated with this mutation. For the extragenic markers, 8 haplotypes were identified. The most frequent of them are the 221 and 112 accounting for 80% of total haplotypes. For the intragenic markers, five haplotypes were present on the E1104X chromosomes. One of them 16-31-13 accounted for 50%. To our knowledge, this is the first work to be interested to the haplotypes linked to the E1104X mutation. This preliminary study of haplotypes could be a helpful method to determine the molecular lesions responsible of this pathology

    Criminal Violence in Libya: A Descriptive, Autopsy-Based Study of Deaths by Firearms in Tripoli

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    Abstract The uprisings in some Arab states during the past several years developed into armed conflicts. Therefore, the incidence of violent crimes has become more common with no reliable data on their patterns. The present study aimed to estimate the magnitude of that problem by studying the frequency and pattern of firearm deaths in Tripoli, Libya. A retrospective descriptive study of autopsy cases of firearm deaths was conducted. The data was retrieved from medico-legal reports of cases that were referred to the Forensic Medicine Department of the Judicial Expertise and Research Center, Ministry of justice, Tripoli, Libya during two years from the 1st of January 2014 to the end of December 2015. Structured data sheets were produced. Out of 4,342 unnatural deaths that were autopsied, 774 cases (17.82 %) were due to firearms. Males were commonly targeted. The mean age of victims was 31.7 ± 11 years with significant predominance in the middle age group. Incidence of firearm deaths in non-Libyans increased in 2015 to 8.5%. Homicidal cases represented 92.12% of cases. There was a significant relationship between manner of firing and sex (p ≤ 0.001). In 95.9% of cases, the firing was from a far range. Rifled weapons were used in 98.32% of cases. Head and neck were targeted in 30.8% of cases. There is a high incidence of illegal firearm use and firearm related deaths in Libya. Societal and international efforts are needed to decrease the illicit use and trafficking of such weapons

    A cross validation of Consumer-Based Brand Equity: driving customer equity in retail brands

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    The Consumer-Based Brand Equity (CBBE) literature has, in recent years, introduced various CBBE models. This study aims to compare the validity of the two prominent CBBE models in the retail industry; those introduced by Yoo and Donthu (2011) and Nam, Ekinci and Whyatt (2011). In order to make this comparison, the study collected data from Turkish (n = 285) and Spanish respondents (n = 236) who had experience with global fashion brands and Private Labels (PL). The findings of the study suggest that Nam et al.'s (2011) CBBE model has better validity than Yoon and Donthu's (2011) model. When brand awareness is included in Nam et al.'s model, the psychometric properties of the model improve and outperform the two models. The study discusses the theoretical contributions and managerial implications of the research

    Novel sequence variations in LAMA2 andSGCG genes modulating cis-acting regulatory elements and RNA secondary structure

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    In this study, we detected new sequence variations in LAMA2 and SGCG genes in 5 ethnic populations, and analysed their effect on enhancer composition and mRNA structure. PCR amplification and DNA sequencing were performed and followed by bioinformatics analyses using ESEfinder as well as MFOLD software. We found 3 novel sequence variations in the LAMA2 (c.3174+22_23insAT and c.6085 +12delA) and SGCG (c. * 102A/C) genes. These variations were present in 210 tested healthy controls from Tunisian, Moroccan, Algerian, Lebanese and French populations suggesting that they represent novel polymorphisms within LAMA2 and SGCG genes sequences. ESEfinder showed that the c. * 102A/C substitution created a new exon splicing enhancer in the 3'UTR of SGCG genes, whereas the c.6085 +12delA deletion was situated in the base pairing region between LAMA2 mRNA and the U1snRNA spliceosomal components. The RNA structure analyses showed that both variations modulated RNA secondary structure. Our results are suggestive of correlations between mRNA folding and the recruitment of spliceosomal components mediating splicing, including SR proteins. The contribution of common sequence variations to mRNA structural and functional diversity will contribute to a better study of gene expression

    First Detection of Leishmania major DNA in Sergentomyia (Spelaeomyia) darlingi from Cutaneous Leishmaniasis Foci in Mali

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    Leishmania major complex is the main causative agent of zoonotic cutaneous leishmaniasis (ZCL) in the Old World. Phlebotomus papatasi and Phlebotomus duboscqi are recognized vectors of L. major complex in Northern and Southern Sahara, respectively. In Mali, ZCL due to L. major is an emerging public health problem, with several cases reported from different parts of the country. The main objective of the present study was to identify the vectors of Leishmania major in the Bandiagara area, in Mali. Methodology/Principal Findings: An entomological survey was carried out in the ZCL foci of Bandiagara area. Sandflies were collected using CDC miniature light traps and sticky papers. In the field, live female Phlebotomine sandflies were identified and examined for the presence of promastigotes. The remaining sandflies were identified morphologically and tested for Leishmania by PCR in the ITS2 gene. The source of blood meal of the engorged females was determined using the cyt-b sequence. Out of the 3,259 collected sandflies, 1,324 were identified morphologically, and consisted of 20 species, of which four belonged to the genus Phlebotomus and 16 to the genus Sergentomyia. Leishmania major DNA was detected by PCR in 7 of the 446 females (1.6%), specifically 2 out of 115 Phlebotomus duboscqi specimens, and 5 from 198 Sergentomyia darlingi specimens. Human DNA was detected in one blood-fed female S. darlingi positive for L. major DNA. Conclusion: Our data suggest the possible involvement of P. duboscqi and potentially S. darlingi in the transmission of ZCL in Mali

    TRUST IN CROSS-CULTURAL B2B FINANCIAL SERVICE RELATIONSHIPS: THE ROLE OF SHARED VALUES

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    This is the accepted version of the following article: Houjeir, R. & Brennan, R. J, 'Trust in cross-cultural b2b financial service relationships: The role of shared values', Journal of Financial Services Marketing, June 2016, Vol 21(2): 90-102 The final publication is available at Springer via http://dx.doi.org/10.1057/fsm.2016.4Trust in business-to-business supplier–customer relationships in financial services is an area of considerable research interest. The bulk of prior empirical research in this field has concentrated on trust in business relationships within a Western cultural context. However, shared values are acknowledged to be an important antecedent to trust. The premise of this study is that in circumstances where there are substantial cultural differences between parties to a supplier–customer relationship, these differences will be reflected in shared values, which will in turn be reflected in differences in the nature of trust. A qualitative study was conducted among business bankers and their corporate clients in the context of the United Arab Emirates. In all 170 respondents were interviewed; of these, 160 were paired respondents, that is, where a client and banker from the same business relationship were interviewed (yielding 80 interview dyads). Substantial differences with respect to trust were found between relationships that involved only Emiratis, those that involved Emiratis and non-Emiratis, and those that involved only non-Emiratis. For Emiratis mutual trust is substantially based on family and clan ties and exhibits strongly affective characteristics. For non-Emiratis trust is largely based on business considerations, and exhibits strongly cognitive characteristics.Peer reviewedFinal Accepted Versio
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