393 research outputs found

    Some larval morphological characteristics of Camelostrongylus mentulatus and Nematodirus spathiger

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    Monitoring of gastrointestinal nematode parasites in ruminants (domestic and wild) is often based on fecal examination techniques, looking for excreted eggs and larval forms using morphological keys. These, are more available in domestic ruminants, in which helminths are widely studied, than in wild ruminants.  This study tried to provide certain morphological elements that will help to recognize the L3 larvae of Camelostrongylus mentulatus and Nematodirus spathiger that could parasite either domestic or wild ruminants. For that, we resorted first to the culture of L3 larvae from fecal samples taken from African antelopes, and second by the microscopic characterization of each isolated larval morphological pattern previously identified by sequencing of its internal transcribed spacer (ITS-2) regions of the ribosomal DNA. The results of different microscopic captured images showed that Camelostrongylus mentulatus larva is 16 intestinal cells that measuring approximately 820 ”m length, ‎≈ 25 ”m wide, and ‎≈ 47 ”m for its sheath tail extension and by this be closer to Teladorsagia circumcincta characteristics.  For Nematodirus spathiger, it possesses 8 gut cells and measuring about 1020 ”m long, ‎≈ 25 ”m wide, and‎ ≈ 143 ”m for its sheath tail extension with specific tail appendages. Have done this, we were able to get some clarifications on the morphology of the studied larvae, and we believe thus that this study will contribute to the establishment of morphological identification keys especially for parasitic nematodes of wild ruminants

    Hydrolysis study: Synthesis of novel styrenic Schiff bases derived from benzothiazole

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    AbstractNovel styrenic Schiff base derivatives of benzothiazole are synthesized. The condensation of 4-vinylbenzaldehyde 1 with either benzothiazol-2-amine or 4-methoxy-benzothiazol-2-amine leads to a mixture of two isomers. From 4-methyl-benzothiazol-2-amine and 6-fluoro-benzothiazol-2-amine, the N-(4-vinylbenzylidene)-4-methyl-benzothiazol-2-amine 8 and N-(4-vinylbenzylidene)-6-fluoro-benzothiazol-2-amine 9 are isolated, respectively. The structures of the synthesized Schiff bases are confirmed through a combination of various spectroscopic techniques including IR, UV, 1H and 13C NMR. A kinetic study of the hydrolysis process of derivatives 6 and 9 in buffered aqueous medium at pH 4.4, 7.4 and 8.5 is conducted by UV spectroscopy. It is shown that the hydrolysis of these compounds is a first order reaction showing an increasing rate as the medium acidity is enhanced

    Does time equal vision in the acute treatment of a cohort of AQP4 and MOG optic neuritis?

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    Objective To investigate whether visual disability which is known to accumulate by poor recovery from optic neuritis (ON) attacks can be lessened by early treatment, we investigated whether the time from symptom onset to high-dose IV methylprednisolone (IVMP) affected visual recovery. Methods: A retrospective study was performed in a consecutive cohort of patients following their first aquaporin-4 (AQP4)-IgG or myelin oligodendrocyte glycoprotein (MOG)-IgG-ON. Best-corrected visual acuity (BCVA) in ON eyes at 3 months (BCVA3mo) was correlated with time to IVMP (days). In cases of bilateral ON, 1 eye was randomly selected. Results: A total of 29 of 37 patients had ON (27 AQP4-seropositive neuromyelitis optica spectrum disorder [NMOSD] and 9 MOG-IgG-ON), 2 of whom refused treatment. Of the 27 patients included, 10 presented later than 7 days from onset. The median BCVA3mo of patients treated >7 days was 20/100 (interquartile range 20/100–20/200). Patients treated >7 days had an OR of 5.50 (95% CI 0.88–34.46, p = 0.051) of failure to regain 0.0 logMAR vision (20/20) and an OR of 10.0 (95% CI 1.39–71.9) of failure to regain 0.2 logMAR vision (20/30) (p = 0.01) compared with patients treated within 7 days. ROC analysis revealed that the optimal criterion of delay in IVMP initiation was ≀4 days, with a sensitivity and specificity of 71.4% and 76.9%, respectively. Conclusions: In this retrospective study of ON with AQP4 and MOG-IgG, even a 7-day delay in IVMP initiation was detrimental to vision. These results highlight the importance of early treatment for the long-term visual recovery in this group of patients. A prospective, multicenter study of the effects of timing of IVMP is currently underway. Classification of evidence: This study provides Class IV evidence that hyperacute treatment of AQP4 and MOG-ON with IVMP increases the chance for good visual recovery (20/20 vision) and that even a greater than 7-day delay in treatment is associated with a higher risk for poor visual recovery

    Analyse économique de la compétitivité de la filiÚre tomate dans la région du Souss-Massa (Maroc)

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    The aim of this study is to evaluate the government’s intervention policies for greenhouse tomato production. The study is based on data collected from a sample of farmers in the Souss-Massa. The choice of the Souss-Massa region was made for several reasons, including the potential of tomato crop production, the share of the greenhouse tomato production in relation to domestic production and the existence of different segments and operators involved in the fresh tomato industry. For this study, we used the Policy Analysis Matrix (PAM) method. Analysis of data showed that tomato production in farms of Souss-Massa region is profitable. It has a comparative advantage and can generate foreign currency. This is due to the lower social costs of tradable inputs and to the fact that actors use many domestic resources in their production systems. Thus, with a Domestic Cost Resources ratio (DRC) below one, the activity is competitive and will be more competitive in case of a decline in social costs of domestic resources. Key words: Tomato, Souss-Massa, policy analysis matrix, reference price, comparative advantageL’objectif de cette Ă©tude est l’évaluation des politiques d’intervention de l’État pour la production de la tomate sous serre. L’étude a Ă©tĂ© basĂ©e sur les donnĂ©es collectĂ©es auprĂšs d’un Ă©chantillon d’agriculteurs de la zone de Souss-Massa. Le choix de la rĂ©gion de Souss-Massa a Ă©tĂ© fait pour plusieurs raisons, notamment, le potentiel de production des cultures sous serre, l’importance de la part de la production de la tomate sous serre par rapport Ă  la production nationale et l’existence des diffĂ©rents segments et opĂ©rateurs qui interviennent dans la filiĂšre tomate. Pour cette Ă©tude, nous avons utilisĂ© la mĂ©thode de la matrice d’analyse des politiques (MAP). L’analyse des donnĂ©es a montrĂ© que la production de la filiĂšre tomate dans les exploitations de la rĂ©gion de Souss-Massa est rentable. Elle a un avantage comparatif aux prix de rĂ©fĂ©rence et peut gĂ©nĂ©rer de la devise Ă©trangĂšre. Ceci s’explique par la diminution des coĂ»ts sociaux des intrants Ă©changeables et par le fait que les acteurs utilisent beaucoup de ressources domestiques dans leurs systĂšmes de production. Par consĂ©quent, avec un CRD (Coefficient de coĂ»t en Ressources Domestiques) infĂ©rieur Ă  l’unitĂ©, l’activitĂ© est compĂ©titive et elle sera plus compĂ©titive en cas de rĂ©gression des coĂ»ts sociaux (Ă©conomiques) des ressources domestiques. Mots clĂ©s: Tomate, Souss-Massa, matrice d’analyse des politiques, prix de rĂ©fĂ©rence, avantage comparati

    COPERNICUS SENTINEL-2 DATA FOR THE DETERMINATION OF GROUNDWATER WITHDRAWAL IN THE MAGHREB REGION

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    Agriculture plays an important role in the economy of the Maghreb region. Most of the water needed for irrigation comes from pumping of the aquifers. A controlled pumping of the groundwater resources does not exist yet, thus, estimating the total water consumption for agricultural use only with in situ data is nearly impossible. In order to overcome this lack of information, Copernicus data are used for determining the groundwater withdrawal through agriculture in the Maghreb region. This paper presents an approach for estimating and monitoring crop water requirements in Tunisia based on multitemporal Sentinel-2 data. Using this multitemporal information, a thorough analysis of the different culture types over time is possible, from which a set of additional multitemporal features is deduced for crop type classification. In this paper, the contribution of those features is analyzed, showing a classification accuracy enhanced by 10 % with the multitemporal features. Furthermore, relying on existing methods and FAO standards for the estimation of crop water needs, the methodology aims to estimate the specific crop water consumption. The results of the water estimates are validated against delimited areas where estimates of the water consumption are available from the authorities. Finally, as the study is conducted within the framework of an international technical cooperation, the methodology aims to be reproducible and sustainable for local authorities. The particularity of the results presented here is that they are achieved through automatic processing and using exclusively Open Source solutions, deployable on simple workstations

    Gridded global surface ozone metrics for atmospheric chemistry model evaluation

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    The concentration of ozone at the Earth's surface is measured at many locations across the globe for the purposes of air quality monitoring and atmospheric chemistry research. We have brought together all publicly available surface ozone observations from online databases from the modern era to build a consistent data set for the evaluation of chemical transport and chemistry-climate (Earth System) models for projects such as the Chemistry-Climate Model Initiative and Aer-Chem-MIP. From a total data set of approximately 6600 sites and 500 million hourly observations from 1971-2015, approximately 2200 sites and 200 million hourly observations pass screening as high-quality sites in regionally representative locations that are appropriate for use in global model evaluation. There is generally good data volume since the start of air quality monitoring networks in 1990 through 2013. Ozone observations are biased heavily toward North America and Europe with sparse coverage over the rest of the globe. This data set is made available for the purposes of model evaluation as a set of gridded metrics intended to describe the distribution of ozone concentrations on monthly and annual timescales. Metrics include the moments of the distribution, percentiles, maximum daily 8-hour average (MDA8), sum of means over 35 ppb (daily maximum 8-h; SOMO35), accumulated ozone exposure above a threshold of 40 ppbv (AOT40), and metrics related to air quality regulatory thresholds. Gridded data sets are stored as netCDF-4 files and are available to download from the British Atmospheric Data Centre (doi:10.5285/08fbe63d-fa6d-4a7a-b952-5932e3ab0452). We provide recommendations to the ozone measurement community regarding improving metadata reporting to simplify ongoing and future efforts in working with ozone data from disparate networks in a consistent manner
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