424 research outputs found

    Water status and yield response to deficit irrigation and fertilization of three olive oil cultivars under the semi-arid conditions of Tunisia

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    Sustainability of olive production is possible by adopting the modern techniques of irrigation and fertilization. In Tunisia, olive trees are usually cultivated in poor soils, under semi-arid conditions characterized by water scarcity. This study investigated the effects of different water supply and fertilization on leaf water status and crop yield of three different olive oil varieties cultivated in central Tunisia, during four experimental seasons (2014-2017). Three treatments were examined: trees conducted under rainfed conditions (TRF), which represented the control treatment, trees irrigated with 50% ETc (T50) and, finally, trees irrigated with 50% ETc and with additional fertilization (T50F). Leaf water content and potential, yield and water use efficiency have been monitored on three different varieties, Chetoui, Chemlali, and Koroneiki, which are quite typical in the considered region. For all the growing seasons, midday leaf water potentials were measured from April to September. Midday leaf water potentials (MLWP) were generally higher for the two irrigated treatments (T50 and T50F) than for non-irrigated trees (TRF). As the season proceeded, MLWPs tended to decrease during summer for all the treatments and varieties. The lowest values were observed for the non-irrigated trees, varying between -3.25 MPa to -4.75 MPa. Relative leaf water content followed the same trends of midday leaf water potentials. Chetoui showed the lowest yield, which did not exceed 1530 Kg/(ha year), even for irrigated and fertilized trees. On the other hand, the yields of Chemlali and Koroneiki, cumulated in the four years, reached the maximum value of about 20 tons/ha. For these two varieties, the cumulated yield obtained in the control treatment (TRF) resulted significantly lower than the corresponding of the other two treatments (T50 and T50F). The highest irrigation water use efficiency (WUE) was estimated for Chemlali (T50) and (TRF). WUE was equal to 1.22 Kg/m3 for Koroneiki under fertigated treatment (T50F). Application of the only water supply (50% ETc) or associated with fertilizer improved the tree water status and increased the productivity of Chemlali and Koroneiki varieties

    Structural, magnetic and vibrational characterization of the new organic-inorganic hybrid material, (C9H14N)2CoCl4

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    A new organic–inorganic hybrid material, bis (N, N-dimethylbenzylammonium) tetrachlorocobaltate (II), (C9H14N)2 CoCl4 was synthesized and analyzed by X-ray diffraction. Magnetization was used to investigate the magnetic properties. The structure was determined at room temperature in the triclinic space group P-1 with the following parameters: a = 10.491 (5)Å, b = 14.207 (2)Å, c = 16.187 (3)Å, α = 87.76 (3)°, β = 88.436 (8)°, γ = 89.897 (10)° and Z = 2. The structure can be described by the alternation of organic-inorganic layers parallel to (110) plan. The different components are connected by the Nsingle bondH⋯Cl hydrogen bonds between the cation and the anionic group [CoCl4]2-. Raman and infrared spectra were used to gain more information of the title compound. An assignment of the observed vibration modes is reported. This compound exhibits an antiferromagnetic (AFM) to paramagnetic (PM) phase transition at a temperature (TN) lower than 2 K. The values of paramagnetic Curie–Weiss temperature θCW, the nearest neighbor interaction Jnn, the classical nearest neighbor J cl and the dipolar Dnn interactions’ emphasize the existence of an antiferromagnetic interaction between the neighboring cobalt ions.publishe

    Effect of dietary vitamin E supplementation on lipid and colour stability of chicken thigh meat

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    Lipid and myoglobin oxidation are major causes of meat quality deterioration during storage of fresh chicken meat. Our objective is to determine the effects of dietary -tocopherol supplementation on lipid and colour stability of fresh chicken thigh meat exposed in a supermarket shopwindow or stored in a refrigerator. Chickens were fed with diets containing 25 (control), 100, 200 or 300 mg vitamin E/kg of food for 20 days before slaughtering. Peroxide value (PV) and oxidation products specific extinctions (K232 and K270), chosen as markers for oxidative deterioration of lipids, were lower in chicken meat from animals supplemented with 200 or 300 mg vitamin E than that of the control meat upon storage during 5 days in a shopwindow (p < 0.01) or 9 days in a refrigerator (p < 0.01). Vitamin E dietary supplementation (200 mg vitamin E/kg of food) reduced oxidation products formation in fresh thighs meat but had no significant impact on colour analysed by value redness (a*) measurements

    Kyste hydatique de la surrénale: à propos d’un cas

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    Le kyste hydatique de la surrénale reste une affection exceptionnelle et une localisation inhabituelle du kyste hydatique, même dans les pays où l'hydatidose sévit à l'état endémique. Nous rapportons un cas de kyste hydatique surrénalien révélé par des douleurs de l'hypochondre droit. Le diagnostic a été évoqué en préopératoire sur les données de la tomodensitométrie abdominale qui avait objectivé une masse kystique surrénalienne droite. La sérologie hydatique était positive. Le traitement chirurgical avait consisté en une résection du dôme saillant et avait permis de conserver la glande. Le kyste était univésiculaire contenant un liquide eau de roche avec une membrane proligère. Les suites opératoires étaient simples. La surveillance à distance, échographique et immunologique, n'avait pas décelé de récidive avec un recul de deux an

    Variation of Grain Yield, Grain Protein Content and Nitrogen Use Efficiency Components under Different Nitrogen Rates in Mediterranean Durum Wheat Genotypes

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    Nitrogen (N) is a crucial nutrient for plant growth and development. To optimize agricultural environments, N fertilizers represent a critical tool to regulate crop productivity. The improvement of nitrogen use efficiency (NUE) represents a promising tool that may enable cereal production to meet future food demand. Wheat reported contrasting behaviors in N utilization showing specific abilities depending on genotype. This study selected two landraces and two improved genotypes from Northern Africa to investigate grain yield (GY), grain protein content (GPC) and NUE. Plants were grown under three levels of N supply: 0, 75, 150 kg N ha−1 and for two consecutive years. Results reported a better NUE (0.40 kg.kg N−1) obtained under 150 kg N ha−1, while N utilization efficiency (NUtE) showed a 13% increase using 75 kg N ha−1 compared with 150 kg N ha−1. Under low nitrogen rate (0 N), crop N supply (CNS) and N uptake efficiency (NUpE) were shown as determinant factors for improved genotypes GY (R2 = 0.72), while NUtE represented the most determinant component for GPC in landraces (R2 = 0.92). Multivariate regression models explained the dependence in GPC on NUE, NUpE, and NUtE. In conclusion, our results recognize GPC and NUtE as suitable selection traits to identify durum wheat with higher NUE

    The Mixing and Transport Properties of the Intra Cluster Medium: a numerical study using tracers particles

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    We present a study of the mixing properties of the simulated intra cluster Medium, using tracers particles that are advected by the gas flow during the evolution of cosmic structures. Using a sample of seven galaxy clusters (with masses in the range of M=2-3 10^14Msol/h) simulated with a peak resolution of 25kpc/h up to the distance of two virial radii from their centers, we investigate the application of tracers to some important problems concerning the mixing of the ICM. The transport properties of the evolving ICM are studied through the analysis of pair dispersion statistics and mixing distributions. As an application, we focus on the transport of metals in the ICM. We adopt simple scenarios for the injection of metal tracers in the ICM, and find remarkable differences of metallicity profiles in relaxed and merger systems, also through the analysis of simulated emission from Doppler-shifted Fe XXIII lines.Comment: 19 pages, 24 figures, Astronomy and Astrophysics accepted; Final version after language editing and updating the bibliograph

    Use of environmental isotopes to assess the sustainability of intensively exploited aquifer systems (2012‐2015)

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    Intensive exploitation of groundwater over longer period has led, in many important aquifers, to marked lowering of water tables, increasing exploitation costs, and often, to a progressive deterioration of water quality. Concentrated pumping may also alter flow patterns permanently with the risk of migration of pollutants into aquifers from the surrounding aquifers or surface water bodies due to lack of physical protection to prevent them. Isotope hydrology tools have proven to be very useful in assessing groundwater hydrology, addressing aspects related to recharge processes, delineation of flow patterns, water quality issues and interactions with other water bodies; this unique information can be further used to evaluate long term aquifer sustainability. The objective of the Coordinated Research Project F33019 is to develop and review approaches and methodologies, mostly based on the combined use of conventional hydrogeological techniques and environmental isotopes, to assess the response of groundwater systems to intensive exploitation and groundwater availability. Access to new dating tools and approaches for groundwater dating covering different time scales offers the possibility to evaluate changes in groundwater dynamics and flow patterns, providing key data to predict the evolution of aquifers and their sustainability as major sources of water. The CRP aims to assess the performance of these new tools and approaches and the possible adoption of these methods by water management experts

    TTF based donor-pi-acceptor dyads synthesized for NLO applications

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    Two new TTF-pi-acceptor dyads that contain p-nitrophenyl group as acceptor and bis-(styryl)benzene system as an efficient π−conjugated bridge have been synthesized by multistep synthetic procedure and their electrochemical behavior has been studied by cyclic voltammetry (CV). The occurrence of an intramolecular charge transfer (ICT) in these molecules has been evidenced by UV–Visible electronic absorption spectroscopy and these studies were completed by DFT calculations in both gas phase and in solution. The nonlinear optical parameters obtained via SHG and THG measurements are described and indicate that these materials are valuable candidates for the construction of optoelectronic and photonic devices. The Optical Kerr Effect measurements indicate that these materials exhibit a great potential in the field of optical switchers construction, where the material\u27s photoresponse time is a crucial parameter

    Mutations in DNAH1, which encodes an inner arm heavy chain dynein, lead to male infertility from multiple morphological abnormalities of the sperm flagella.

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    International audienceTen to fifteen percent of couples are confronted with infertility and a male factor is involved in approximately half the cases. A genetic etiology is likely in most cases yet only few genes have been formally correlated with male infertility. Homozygosity mapping was carried out on a cohort of 20 North African individuals, including 18 index cases, presenting with primary infertility resulting from impaired sperm motility caused by a mosaic of multiple morphological abnormalities of the flagella (MMAF) including absent, short, coiled, bent, and irregular flagella. Five unrelated subjects out of 18 (28%) carried a homozygous variant in DNAH1, which encodes an inner dynein heavy chain and is expressed in testis. RT-PCR, immunostaining, and electronic microscopy were carried out on samples from one of the subjects with a mutation located on a donor splice site. Neither the transcript nor the protein was observed in this individual, confirming the pathogenicity of this variant. A general axonemal disorganization including mislocalization of the microtubule doublets and loss of the inner dynein arms was observed. Although DNAH1 is also expressed in other ciliated cells, infertility was the only symptom of primary ciliary dyskinesia observed in affected subjects, suggesting that DNAH1 function in cilium is not as critical as in sperm flagellum
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