312 research outputs found

    Investigation of the Mechanism of Apatite/Carbonates Separation in Acidic Flotation Process Using In Situ Raman Spectroscopy

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    The separation of phosphate from carbonate gangue using flotation is extremely complex due to the similarities in surface properties. The acidic flotation process of carbonates at pH 4.5-5.0 followed by a direct phosphate flotation uses phosphoric acid as depressor of apatite during carbonate flotation. The mechanism of apatite depression is rather hypothetical because of lack of data on the surface speciation in such a complex mineral suspension. A real-time method for in situ control of surface compounds on the minerals (carbonated hydroxylapatite and calcite) using a submerged Raman analyzer probe is proposed in this work to collect the data on the nature and kinetics of phase formed. The carbonated hydroxyfluorapatite (C-HFAp) and calcite reactivity in phosphoric acid at concentrations between 0 and 1 M) during 15 minutes was studied. The Raman spectra collected in situ and ex situ showed the peak at 1085 cm-1 of calcium carbonate at 10-3 and 10-1 M on the surface of hydroxyfluorapatite that disappears at high acid concentration. Kinetics studies performed at 4.6 (±0.1) pH range during 15 minutes showed calcium carbonate formation after 2 minutes of conditioning and that disappears after three minutes (Figure 1). The infrared spectra of C-HFAp in presence of phosphoric acid showed at 10-3 and 10-1 M new peak at 713 cm-1 that belongs to calcium carbonate vibrations which seems to be due to C-HFAp surface conversion as observed on XRD patterns. Please click Additional Files below to see the full abstract

    Epidemiological study of canine trypanosomosis in an urban area of Ivory Coast

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    Following confirmed cases of trypanosomosis in military working dogs, c cross-sectional study was undertaken to evaluate the source of infection and determine the prevalence of canine infection with Trypanosoma congolense in the urban focus of Abidjan, Ivory Coast. Blood from 123 dogs were collected and subjected to PCR using specific primers for Trypanosoma congolense "forest type". In addition, an entomological study was conducted in an urban area near the forest surronding the military camp. The observed prevalence was 30.1% end PCR positivity to Trypanosoma congolense was not significantly associated with sex or age of animals. This study demonstrates the high contamination rate of dogs in enzootic zones, the potential risk of introduction of the disease in free animal populations and the ability of Glossina palpalis to adopt to urban areas and to transmit trypanosomosis in such areas. The factors leading to a possible emergence of canine trypanosomiasis in enzootic zones need further investigations

    Contribution à la dépollution d’un rejet textile par adsorption sur un coagulant à base du mélange fer/aluminium préparé par électrocoagulation

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    L’industrie textile consomme une grande quantité d’eau, générant ainsi des rejets liquides à charge élevée en divers types de polluants. Ces derniers produisent des effets nocifs sur l’environnement. Ce travail s’intéresse à la dépollution d’un rejet d’une industrie textile, par addition d’un coagulant synthétique à base de fer et d’aluminium, préparé par le procédé d’électrocoagulation. Les résultats ont montré que le traitement de ce rejet par ce coagulant, a permis d’atteindre un rendement d’élimination des matières colorantes de 83.37% en terme de demande chimique en oxygène (DCO).Mots clés: traitement, hydroxyde, coagulation, demande chimique en oxygèn

    Species occurrence of cetaceans in Guinea, including humpback whales with southern hemisphere seasonality

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    An initial inventory of the dolphins and whales occurring in Guinea's coastal waters is documented primarily from specimens and photographic evidence obtained from strandings and by-catches. Seven species are fully validated, four odontocetes, Tursiops truncatus, Sousa teuszii, Stenella frontalis, Kogia breviceps and three balaenopterid whales: Balaenoptera brydei, Balaenoptera acutorostrata and Megaptera novaeangliae. Another three reported species (Globicephala macrorhynchus, Steno bredanensis and Delphinus delphis) are insufficiently supported but thought to be valid. Small cetaceans landed as by-catch and a stranded whale were used for human consumption, but no evidence of substantial takes, directed or by-catch, was found. However, concern is raised about even minimal takes of the vulnerable Atlantic humpback dolphin. The seasonal presence of three confirmed humpback whales, two strandings (July and September) and a sighting (October), is synchronous with the species' southern hemisphere wintering/breeding season in low latitudes. We hypothesize that these whales may comprise the north-westernmost range of the population that breeds/overwinters in coastal waters of the Bight of Benin, northern Gulf of Guinea

    The cetaceans of Guinea, a first check-list of documented species. Scientific Committee document SC/58/O15, International Whaling Commission, May-June 2006, St. Kitts

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    A CMS workshop on West African Cetacea (Conakry, May 2000), called for i.a. ‘carrying out .. inventory of cetacean species; collection, treatment and compilation of data for each state.’ The present paper is a preliminary faunal checklist of cetaceans occurring in Guinea’s EEZ. Information was gleaned from strandings, bycatches, scientific and opportunistic sightings and a literature review. Ten species are included for which supporting voucher material and data were available for examination. These are, three baleen whales: Balaenoptera brydei, Balaenoptera acutorostrata and Megaptera novaeangliae; and seven species of odontocetes: Kogia breviceps, Tursiops truncatus, Sousa teuszii, Stenella frontalis, Delphinus delphis, Steno bredanensis and Globicephala macrorhynchus. Another two species, Physeter macrocephalus and Stenella attenuate were sighted off Guinea but no photographic evidence was obtained. The current account is thought to reflect an incomplete picture of Guinea’s cetacean biodiversity. Future surveys are expected to update and investigate spatial and temporal distribution patterns for each species along Guinea’s coast. A few bycatches landed by artisanal fishers were utilised locally, but there are no signs of any substantial captures. Nonetheless, monitoring should be continued. The set-up of a national reference collection and database is recommended. The population identities of the encountered Atlantic humpback dolphin, minke whale and humpback whale are of particular interest

    Detection and identification of pathogenic trypanosome species in tsetse flies along the Comoe River in Cote d'Ivoire

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    In order to identify pathogenic trypanosomes responsible for African trypanosomiasis, and to better understand tsetse-trypanosome relationships, surveys were undertaken in three sites located in different eco-climatic areas in Cote d'Ivoire during the dry and rainy seasons. Tsetse flies were caught during five consecutive days using biconical traps, dissected and microscopically examined looking for trypanosome infection. Samples from infected flies were tested by PCR using specific primers for Trypanosoma brucei s.l., T. congolense savannah type, T. congolense forest type and T. vivax. Of 1941 tsetse flies caught including four species, i.e. Glossina palpalis palpalis, G. p. gambiensis, G. tachinoides and G. medicorum, 513 (26%) were dissected and 60 (12%) were found positive by microscopy. Up to 41% of the infections were due to T. congolense savannah type, 30% to T. vivax, 20% to T. congolense forest type and 9% due to T. brucei s.l. All four trypanosome species and subgroups were identified from G. tachinoides and G. p. palpalis, while only two were isolated from G. p. gambiensis (T. brucei s.l., T. congolense savannah type) and G. medicorum (T. congolense forest, savannah types). Mixed infections were found in 25% of cases and all involved T. congolense savannah type with another trypanosome species. The simultaneous occurrence of T. brucei s.l., and tsetse from the palpalis group may suggest that human trypanosomiasis can still be a constraint in these localities, while high rates of T. congolense and T. vivax in the area suggest a potential risk of animal trypanosomiasis in livestock along the Comoe River

    Contribution à la dépollution des eaux usées de textile par électrocoagulation et par adsorption sur des composés à base de fer et d’aluminium

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    Les ressources hydriques au monde sont rares et la demande en eau connaît une croissance continue en liaison avec l’évolution démographique et les activités consommatrices en eau, notamment les industries de textiles se voient dans l’obligation de recycler les eaux résiduaires et en particulier celles colorées. Dans ce travail, nous nous sommes intéressés à l’étude de l’élimination des matières organiques et colorantes de deux rejets provenant des industries de textile, un de teinture du tissu de polyester à pH acide et l’autre de teinture du tissu de coton à pH basique. Ces rejets ont été traités de deux manières. La première est par électrocoagulation en utilisant des plaques de fer et/ou d’aluminium. La deuxième est par adsorption sur des composés synthétiques à base de fer et d’aluminium préparés par électrocoagulation. Dans le cas du traitement par le procédé d’électrocoagulation, nous avons constaté que le rendement d’élimination en demande chimique en oxygène (DCO) du rejet de polyester atteint un rendement de DCO de 60% pour un temps de 7 min de réaction. Pour le rejet de coton, le rendement d’élimination, par les plaques de fer/aluminium et l’élimination des matières colorantes, atteint une valeur de 45% en terme de DCO, et ceci en utilisant des plaques d’aluminium seul et de fer/aluminium pour un temps de 12 et 15 min respectivement. Dans le cas du traitement par ajout des coagulants synthétiques préparés au laboratoire, nous pouvons observer que le meilleur rendement d’élimination en DCO du rejet de polyester est obtenu pour une valeur de 48%, pour la faible granulométrie avec une concentration de 5 g/l du composé à base de fer /aluminium. Le rendement d’élimination en DCO du rejet de coton augmente jusqu'à une valeur de 60% avec une concentration de 5 g/l de coagulants appliqués à base d’aluminium seul. Les résultats de la dépollution de ces rejets, ont montré que le rendement d'élimination des matières organiques et colorantes par le procédé d'électrocoagulation est important, et la durée de traitement est courte, mais l'inconvénient de ce procédé c'est la saleté des plaques après chaque utilisation et la fabrication d'une grande quantité des boues par rapport à l’adsorption sur des composés à base de fer /aluminium où on utilise des poudres peu solubles et stables avec un bon rendement d’élimination et faibles quantités de fer et d'aluminium dans le surnageant traité.Keywords: Colorant textile, électrocoagulation, adsorption, dépollution, fer, aluminiu

    Production of cornelian cherry (Cornus mas L.) pulp powder by foam-mat drying: analysis of physicochemical and antioxidant properties

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    This is the final version, Available on open access from Springer via the DOI in this recordAvailability of data and materials: Data available within the article or its supplementary materialsCornelian cherry (Cornus mas L.) is a rich source of (poly)phenols such as phenolic acids, flavonoids, and anthocyanins that are known for their bioactivity. This study aimed to enhance the industrial applications of this cherry’s pulp as a potential functional food ingredient. Foam-mat drying was used to produce cherry powder from cherry pulp. The convective drying process was performed at different temperatures (50, 60, 70, and 80°C) to study the effect of drying temperature on the physical properties, flow properties, microstructure, (poly)phenol content, antioxidant properties, and bioaccessibility of foam-dried cherry pulp, in comparison to freeze-dried sample. Different drying temperatures did not affect color properties. The highest gloss was determined at high temperatures (70–80°C). According to the Carr index, the fluidity increased between 18 and 22% as the temperature increased. The total phenolic content was higher at elevated temperatures (70–80°C), yet the anthocyanin content was the highest at 60°C. The flavonoid content was not affected by different drying temperatures, as well as compared to lyophilized samples. The antioxidant activity was higher in samples dried at elevated temperatures, with no significant difference in comparison to lyophilized samples. The bioaccessibility experiment showed that the lyophilized samples had significantly greater bioaccessibility in comparison to the convective dried samples, yet further investigation is required to understand the differences in bioaccessibility and bioavailability of individual polyphenols. Overall, foam-mat drying using a convective drying system could be an economic choice to preserve acceptable amounts of phenolics and antioxidants

    Towards an optimal design of target for tsetse control: comparisons of novel targets for the control of palpalis group tsetse in West Africa

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    Background: Tsetse flies of the Palpalis group are the main vectors of sleeping sickness in Africa. Insecticide impregnated targets are one of the most effective tools for control. However, the cost of these devices still represents a constraint to their wider use. The objective was therefore to improve the cost effectiveness of currently used devices. Methodology/Principal Findings: Experiments were performed on three tsetse species, namely Glossina palpalis gambiensis and G. tachinoides in Burkina Faso and G. p. palpalis in Côte d'Ivoire. The 1×1 m2 black blue black target commonly used in W. Africa was used as the standard, and effects of changes in target size, shape, and the use of netting instead of black cloth were measured. Regarding overall target shape, we observed that horizontal targets (i.e. wider than they were high) killed 1.6-5x more G. p. gambiensis and G. tachinoides than vertical ones (i.e. higher than they were wide) (P<0.001). For the three tsetse species including G. p. palpalis, catches were highly correlated with the size of the target. However, beyond the size of 0.75 m, there was no increase in catches. Replacing the black cloth of the target by netting was the most cost efficient for all three species. Conclusion/Significance: Reducing the size of the current 1*1 m black-blue-black target to horizontal designs of around 50 cm and replacing black cloth by netting will improve cost effectiveness six-fold for both G. p. gambiensis and G. tachinoides. Studying the visual responses of tsetse to different designs of target has allowed us to design more cost-effective devices for the effective control of sleeping sickness and animal trypanosomiasis in Africa

    Turner syndrome and associated problems in turkish children: A multicenter study

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    Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population. Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014. Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosi) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto’s thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%. Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan. © Journal of Clinical Research in Pediatric Endocrinology
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