2,074 research outputs found

    Managing nitrate pollution in a Tunisian irrigated area: A multi-criteria analysis approach

    Get PDF
    In Tunisia, the extension of irrigated area is justified by its important role in the development and diversification of agricultural production. Nevertheless, the strong intensification of the agricultural activities may lead to the pollution of underground water resources due to an excess use of fertilisers and other chemical products. In fact, the high nitrate concentrations observed in some Tunisian irrigated areas, are related to the excessive use of nitrate fertilizers in intensive agriculture. The objective of the present study is to implement decision-making methods allowing a better combination of factors production by optimization of an economic objective and an environmental objective. This research is based on multi-criteria modelling through the optimization of two conflict objectives: an economic objective as settled by farmer in the short or medium-run (Gross margin), and an environmental objective (nitrate pollution reduction) as a long-run objective of the decision maker in order to ensure the continuity of agriculture activities and ecosystems sustainability. Data were collected through a survey conducted in the irrigated area of Kalaât El Andalous in Tunisia with a sample containing 57 farms. Efficient solutions were obtained and compared through the "constraints", "NISE" and "compromises" methods. Main results obtained indicate a significant degree of conflict between these two objectives. Indeed the maximization of the total gross margin involves an increase in the degrees of nitrate pollution and conversely. Finally, some policy implications are presented.Nitrate pollution, environmental impact, multicriteria analysis, Environmental Economics and Policy,

    Synthesis and physico-chemical studies of a novel noncentrosymmetric heptacoordinated cadmium(II) compound containing a tripodal amine, CdCl2[N(C2H6N)3]2

    Get PDF
    A new noncentrosymmetric Cd(II) complex with thetripodal amine tris(2-aminoethyl)amine, CdCl2[N(C2H6N)3]2, has been prepared and characterized by single crystal X-ray diffraction, solid state NMR and IR spectroscopies. In the complex, the Cd(II) ion is surrounded by sevennitrogen atoms. The organic molecule acts as both a tri-and a tetradentate ligand. The cationic complexes are linked to each other forming layers parallel to the (a, b)plan. The Cl- counter ions occupy the cavities created inside these layers. The 13C CP-MAS NMR spectra are in agreement with the X-ray structure. DFT calculations allow the attribution of the carbon peaks to the differentatoms.The vibrational absorption bands were identified by infrared spectroscopy and DFT calculations allowed their attributions

    Synthesis, crystal structure and spectroscopic characterization of a new organic bismuthate (III) [C9H28N4][Bi2Cl10].H2O

    Get PDF
    The chemical preparation, crystal structure and spectroscopic characterization of [C9H28N4][Bi2Cl10].H2O have been reported. This compound crystallizes in the monoclinic system in space group P21/c and cell parameters a = 12.2385 (6), b = 17.3062 (7), c = 13.0772 (6) Å, β = 104.475 (5)°, Z = 4 and V = 2681.9 (2) Å3. Its crystal structure has been determined and refined to R = 0.049, using 5848 independent reflections. The atomic arrangement can be described by an alternation of organic and inorganic layers. The inorganic layer built up of [Bi2Cl10]4– bioctahedra arranged in sandwich between the organic layer. The organic groups are interconnected by the water molecules through N-H…O(W) hydrogen bonds to form infinite zig-zag chains spreading along the b-axis. These Chains are themselves interconnected by means of the N–H…Cl hydrogen bonds originating from [Bi2Cl10]4– anions, to form a three-dimensional network. Intermolecular Cl…Cl interactions between adjacent dimeric [Bi2Cl10]4– anions have been observed. The compound was also characterized by FT-IR and Raman spectrscopies

    Crystalline and Molecular Structure of Hexaaqua-1,3-diammoniumpropane Cobalt(II) Nitrate, Co(H 2

    Get PDF
    Chemical preparation and x-ray characterization of a new compound hexaaqua-1,3-diammoniumpropane cobalt(II) nitrate, Co(H2O) 6 [C3H12N2] (NO3)4 are reported. This mixed organo-mineral compound crystallizes in the orthorhombic system with Cmcm space group. The unit cell dimensions are: a = 10.795(7), b = 11.969(4), c = 14.685(5) Å, Z = 4 and V = 1897.5(12) Å3. The structure was solved using the direct method and refined to reliability R-factor of 0.036 using 2554 independent reflections. In this atomic arrangement the different species built a three-dimensional network

    Positive effects of a novel non-peptidyl low molecular weight radical scavenger in renal ischemia/reperfusion: a preliminary report

    Get PDF
    Ischemia/reperfusion (I/R) is one of the most common causes of acute kidney injury. Reactive oxygen species have been recognized to be an important contributor to the pathogenesis of I/R injury. We hypothesize that a non-peptidyl low molecular weight radical scavenger (IAC) therapy may counteract this factor, ultimately providing some protection after acute phase renal I/R injury. The aim of this preliminary study was to assess the ability of IAC to reduce acute kidney injury in C57BL/6 mice after 30-minute of bilateral ischemia followed by reperfusion. The rise in serum creatinine level was higher in C57BL/6 control mice after I/R when compared to IAC (1 mg)-treated mice. Control mice showed greater body weight loss compared to IAC-treated mice, and at pathology, reduced signs of tubular necrosis were also evident in IAC-treated mice. These preliminary evidences lay the basis for more comprehensive studies on the positive effects of IAC as a complementary therapeutic approach for acute phase renal I/R injury

    Immune heterogeneity of head and tail pancreatic lymph nodes in non-obese diabetic mice

    Get PDF
    The pancreatic lymph node is critical to the pathogenesis of autoimmune diabetes, as it constitutes the initial site for the priming of autoreactive T cells. In this study, we compared the histopathology of the head pancreatic lymph node (HPLN) to the tail pancreatic lymph node (TPLN) in NOD mice. HPLNs and TPLNs were harvested from 4 week-, 8 week-, and 12 week-old NOD mice, and their microvasculature, extracellular matrix, and immune cell subsets were characterized. The percentages of B cells and antigen-presenting cells (APCs) were much higher in the HPLN, as compared to the TPLN. Notably, the HPLNs of 12 week-old mice were characterized by greater expansion of high endothelial venules (HEVs) and lymphatic vessels in comparison to the TPLNs. Finally, we observed a higher density of extracellular matrix (ECM) fibers surrounding the lymphatic vasculature in the HPLNs than in the TPLNs. These data for the first time demonstrate that the HPLN possesses a different immune microanatomy and organization from the TPLN. These novel observations unveil a major phenotypic difference between two types of LNs from the same organ and may highlight an independent fundamental role played by each PLN during the establishment of T1D

    Bis(2-amino-6-methyl­pyrimidin-1-ium-4-olate-κ2 N 3,O)bis­(nitrato-κ2 O,O′)cadmium(II)

    Get PDF
    In the title compound, [Cd(NO3)2(C5H7N3O)2], the CdII atom is eight-coordinated by two amine N atoms and two O atoms from two zwitterionic, biodentate 2-amino-6-methyl­pyrimidin-1-ium-4-olate ligands and by four O atoms from two nitrate groups. Intra­molecular N—H⋯O hydrogen bonds occur. The crystal packing is stabilized by inter­molecular N—H⋯O and C—H⋯O hydrogen bonds, two of which are bifurcated, between the nitrate anions and the organic groups

    Bis[2-amino-6-methyl­pyrimidin-4(1H)-one-κ2 N 3,O]dichloridocadmium(II)

    Get PDF
    In the title compound, [CdCl2(C5H7N3O)2], the CdII atom is six-coordinated by two heterocyclic N atoms [Cd—N = 2.261 (2) and 2.286 (2) Å] and two O atoms [Cd—O = 2.624 (2) and 2.692 (2) Å] from two bidentate chelate 2-amino-6-methyl­pyrimidin-4(1H)-one ligands and two chloride ions [Cd—Cl = 2.4674 (6) and 2.4893 (7) Å]. The crystal packing is characterized by an open-framework architecture with the crystal packing stabilized by inter­molecular N—H⋯Cl and N—H⋯O hydrogen bonds

    A New Zn(II) Metal Hybrid Material of 5-Nitrobenzimidazolium Organic Cation (C7H6N3O2)2[ZnCl4]: Elaboration, Structure, Hirshfeld Surface, Spectroscopic, Molecular Docking Analysis, Electric and Dielectric Properties

    Get PDF
    The slow solvent evaporation approach was used to create a single crystal of (CHNO)[ZnCl] at room temperature. Our compound has been investigated by single-crystal XRD which declares that the complex crystallizes in the monoclinic crystallographic system with the P2/c as a space group. The molecular arrangement of the compound can be described by slightly distorted tetrahedral ZnCl anionic entities and 5-nitrobenzimidazolium as cations, linked together by different non-covalent interaction types (H-bonds, Cl…Cl, π…π and C–H…π). Hirshfeld’s surface study allows us to identify that the dominant contacts in the crystal building are H…Cl/Cl…H contacts (37.3%). FT-IR method was used to identify the different groups in (CHNO)[ZnCl]. Furthermore, impedance spectroscopy analysis in 393 ≤ T ≤ 438 K shows that the temperature dependence of DC conductivity follows Arrhenius’ law. The frequency–temperature dependence of AC conductivity for the studied sample shows one region (E = 2.75 eV). In order to determine modes of interactions of compound with double stranded DNA, molecular docking simulations were performed at molecular level

    Co-transplantation of Human Embryonic Stem Cell-derived Neural Progenitors and Schwann Cells in a Rat Spinal Cord Contusion Injury Model Elicits a Distinct Neurogenesis and Functional Recovery

    Get PDF
    Co-transplantation of neural progenitors (NPs) with Schwann cells (SCs) might be a way to overcome low rate of neuronal differentiation of NPs following transplantation in spinal cord injury (SCI) and the improvement of locomotor recovery. In this study, we initially generated NPs from human embryonic stem cells (hESCs) and investigated their potential for neuronal differentiation and functional recovery when co-cultured with SCs in vitro and co-transplanted in a rat acute model of contused SCI. Co-cultivation results revealed that the presence of SCs provided a consistent status for hESC-NPs and recharged their neural differentiation toward a predominantly neuronal fate. Following transplantation, a significant functional recovery was observed in all engrafted groups (NPs, SCs, NPs+SCs) relative to the vehicle and control groups. We also observed that animals receiving co-transplants established a better state as assessed with the BBB functional test. Immunohistofluorescence evaluation five weeks after transplantation showed invigorated neuronal differentiation and limited proliferation in the co-transplanted group when compared to the individual hESC-NPs grafted group. These findings have demonstrated that the co-transplantation of SCs with hESC-NPs could offer a synergistic effect, promoting neuronal differentiation and functional recovery
    corecore