648 research outputs found

    Effect of nitrogen level application on yield and fruit quality of Navel orange variety in a sandy soil

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    L’objectif de cet essai est d'évaluer l'effet de la dose d'azote sur le rendement et la qualité des fruits et de déterminer la dose optimale en azote pour les arbres de l’orange Navel greffé sur le porte-greffe citrange Troyer planté en 1964 en plein champ à un espacement de 7mx7m (204 arbres/ha) au niveau de la station expérimentale d’El Menzeh, INRA Maroc. Le dispositif adopté est un bloc aléatoire complet avec trois blocs rangés en 4 arbres consécutifs par bloc sur la même ligne. Quatre doses de N ont été testés : (T0 (Témoin) : 0, T1 : 100, T2 : 200, T3 : 300 Kg N/ha). Les paramètres mesurés sont : le calibre des fruits, le poids moyen par fruit, la qualité des fruits (le rendement en jus, l’acidité du jus, l’extrait sec soluble (ESS ou °Brix) et l’indice de maturité (E/A)) et le rendement en fruits. Le rendement en fruits, le poids moyen des fruits, le calibre des fruits, l’extrait sec soluble (TSS), l'acidité du jus et l'indice de maturité de l’orange Navel ont répondu significativement à l’augmentation de la dose d’azote. Le rendement en kg de fruits/arbre a été considérablement amélioré avec l'augmentation de la dose d'azote. Par ailleurs, les rendements les plus élevés (129.21 et 139.82 kg/arbre) ont été enregistrés sous les traitements T2 et T3 respectivement. Par contre, le rendement en fruits/arbre le plus faible a été obtenu chez les arbres non fertilisés (témoin). Le poids des fruits (268.54 et 276.50g) et la taille des fruits (78.94 et 80.87 mm) les plus élevés ont été enregistrés avec les même traitements T2 et T3 respectivement. La teneur totale en sucre soluble (TSS) la plus élevée a été enregistrée chez les arbres des traitements T2 et T3 (12.20 et 11.70 °Brix respectivement). Par ailleurs, une augmentation significative de l'acidité du jus de fruits de l’orange Navel a été également enregistrée en augmentant la dose d’azote. L'acidité la plus élevée a été obtenue par les mêmes traitements T2 et T3 (1,13 et 1.20 % respectivement). L’application de 200 Kg de N /ha a permis d’avoir un rendement maximal et une qualité optimale des fruits des oranges Navel greffés sur le porte-greffe citrange Troyer sur un sol sableux dans la région de Gharb.The objective of the present paper was to evaluate the effect of nitrogen level on yield and fruit quality of citrus and to determine the optimum N fertilizer rates of Navel orange variety budded on Troyer citrange rootstock in field conditions. The orange Navel orchard spaced 7mx7m (204 trees/ha) grown in 1964 on a sandy soil at the experimental station of El Menzeh, INRA Morocco. The experiment was set up in a complete randomized block design with three blocks and the experimental unit was composed on 4 consecutive trees in the row. Four fertilization treatments of N (Kg/ha) (T0 (control): 0, T1: 100, T2: 200, T3: 300) were applied to Navel citrus tree in field conditions over two seasons 2012-2013 and 2013-2014.Fruit yield, fruit weight, fruit size, total soluble sugar (TSS) content, acidity of juice and maturity index of Navel orange were significantly affected by increasing N level. Fruit yield/tree was improved significantly with increase in N rate. Significant highest yields (129.21 and 139.82. kg/tree) were recorded under treatments T2 and T3 respectively. The lowest fruit yield/tree was obtained from untreated control plot. Maximum fruit weight (268.54 and 276.50 g) and fruit size (78.94 and 80.87 mm) was recorded with the same treatments T2 and T3 respectively. Total soluble sugar content was also maximum in trees receiving treatment (T2) and treatment (T3) 12.20 and 11.70°Brix respectively. Significant increase in acidity of juice of fruit Navel orange was also recorded by increasing the rate of N. The highest acidity (1.13 and 1.20%) was achieved by the same treatments T2 and T3 respectively. Two-year studies showed that application of fertilizers at the rate of 200 Kg N/ha would be optimum for achieving higher yield and better fruit quality of Navel orange variety in sandy soil in Gharb area

    Anticancer and anti-inflammatory effects of tomentosin: Cellular and molecular mechanisms

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    Tomentosin is a natural compound known for its presence in some medicinal plants of the Asteraceae family such as Inula viscosa. Recent studies have highlighted its anticancer and anti-inflammatory properties. Its anticancer mechanisms are unique and act at different levels ranging from cellular organization to molecular transcriptional factors and epigenetic modifications. Tomentosin’s possession of the modulatory effect on telomerase expression on tumor cell lines has captured the interest of researchers and spurred a more robust study on its anticancer effect. Since inflammation has a close link with cancer disease, this natural compound appears to be a potential cancer-fighting drug. Indeed, its recently demonstrated anti-inflammatory action can be considered as a starting point for its evaluation as an anticancer chemo-preventive agent

    Mcl-1 is a key regulator of the ovarian reserve

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    A majority of ovarian follicles are lost to natural death, but the disruption of factors involved in maintenance of the oocyte pool results in a further untimely follicular depletion known as premature ovarian failure. The anti-apoptotic B-cell lymphoma 2 (Bcl-2) family member myeloid cell leukemia-1 (MCL-1) has a pro-survival role in various cell types; however, its contribution to oocyte survival is unconfirmed. We present a phenotypic characterization of oocytes deficient in Mcl-1, and establish its role in maintenance of the primordial follicle (PMF) pool, growing oocyte survival and oocyte quality. Mcl-1 depletion resulted in the premature exhaustion of the ovarian reserve, characterized by early PMF loss because of activation of apoptosis. The increasingly diminished surviving cohort of growing oocytes displayed elevated markers of autophagy and mitochondrial dysfunction. Mcl-1-deficient ovulated oocytes demonstrated an increased susceptibility to cellular fragmentation with activation of the apoptotic cascade. Concomitant deletion of the pro-apoptotic Bcl-2 member Bcl-2-associated X protein (Bax) rescued the PMF phenotype and ovulated oocyte death, but did not prevent the mitochondrial dysfunction associated with Mcl-1 deficiency and could not rescue long-term breeding performance. We thus recognize MCL-1 as the essential survival factor required for conservation of the postnatal PMF pool, growing follicle survival and effective oocyte mitochondrial function

    Conformational flexibility of the oncogenic protein LMO2 primes the formation of the multi-protein transcription complex

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    LMO2 was discovered via chromosomal translocations in T-cell leukaemia and shown normally to be essential for haematopoiesis. LMO2 is made up of two LIM only domains (thus it is a LIM-only protein) and forms a bridge in a multi-protein complex. We have studied the mechanism of formation of this complex using a single domain antibody fragment that inhibits LMO2 by sequestering it in a non-functional form. The crystal structure of LMO2 with this antibody fragment has been solved revealing a conformational difference in the positioning and angle between the two LIM domains compared with its normal binding. This contortion occurs by bending at a central helical region of LMO2. This is a unique mechanism for inhibiting an intracellular protein function and the structural contusion implies a model in which newly synthesized, intrinsically disordered LMO2 binds to a partner protein nucleating further interactions and suggests approaches for therapeutic targeting of LMO2

    The Stability of the Weak Skyrmions

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    We consider a set of gauge invariant terms in higher order effective Lagrangians of the strongly interacting scalar of the electroweak theory. The terms are introduced in the framework of the hidden gauge symmetry formalism. The usual gauge term is known to stabilize the skyrmion but only in the large vector mass limit. We find that adding higher-order gauge terms is insufficient to insure stability. We then proceed to analyze other gauge invariant interaction terms. Some of the conclusions also apply to QCD skyrmions.Comment: 3 pages, revtex v3, (optional), LAVAL-PHY-11-9

    Deterministic control of magnetic vortex wall chirality by electric field

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    Concepts for information storage and logical processing based on magnetic domain walls have great potential for implementation in future information and communications technologies. To date, the need to apply power hungry magnetic fields or heat dissipating spin polarized currents to manipulate magnetic domain walls has limited the development of such technologies. The possibility of controlling magnetic domain walls using voltages offers an energy efficient route to overcome these limitations. Here we show that a voltage-induced uniaxial strain induces reversible deterministic switching of the chirality of a magnetic vortex wall. We discuss how this functionality will be applicable to schemes for information storage and logical processing, making a significant step towards the practical implementation of magnetic domain walls in energy efficient computing

    Out-of-Pocket Costs and Other Determinants of Access to Healthcare for Children with Febrile Illnesses: A Case-Control Study in Rural Tanzania.

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    To study private costs and other determinants of access to healthcare for childhood fevers in rural Tanzania. A case-control study was conducted in Tanzania to establish factors that determine access to a health facility in acute febrile illnesses in children less than 5 years of age. Carers of eligible children were interviewed in the community; cases were represented by patients who went to a facility and controls by those who did not. A Household Wealth Index was estimated using principal components analysis. A multivariable logistic regression analysis was performed to understand the factors which influenced attendance of healthcare facility including severity of the illness and household wealth/socio-demographic indicators. To complement the data on costs from community interviews, a hospital-based study obtained details of private expenditures for hospitalised children under the age of 5. Severe febrile illness is strongly associated with health facility attendance (OR: 35.76, 95%CI: 3.68-347.43, p = 0.002 compared with less severe febrile illness). Overall, the private costs of an illness for patients who went to a hospital were six times larger than private costs of controls (5.68vs.5.68 vs. 0.90, p<0.0001). Household wealth was not significantly correlated with total costs incurred. The separate hospital based cost study indicated that private costs were three times greater for admissions at the mission versus public hospital: 13.68missionvs.13.68 mission vs. 4.47 public hospital (difference $ 9.21 (95% CI: 7.89 -10.52), p<0.0001). In both locations, approximately 50% of the cost was determined by the duration of admission, with each day in hospital increasing private costs by about 12% (95% CI: 5% - 21%). The more severely ill a child, the higher the probability of attending hospital. We did not find association between household wealth and attending a health facility; nor was there an association between household wealth and private cost

    Bolus residue scale: an easy-to-use and reliable videofluoroscopic analysis tool to score bolus residue in patients with dysphagia

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    Background. We aimed to validate an easy-to-use videofluoroscopic analysis tool, the bolus residue scale (BRS), for detection and classification of pharyngeal retention in the valleculae, piriform sinuses, and/or the posterior pharyngeal wall. Methods. 50 randomly selected videofluoroscopic images of 10 mL swallows (recorded in 18 dysphagia patients and 8 controls) were analyzed by 4 experts and 6 nonexpert observers. A score from 1 to 6 was assigned according to the number of structures affected by residue. Inter- and intrarater reliabilities were assessed by calculation of intraclass correlation coefficients (ICCs) for expert and nonexpert observers. Sensitivity, specificity, and interrater agreement were analyzed for different BRS levels. Results. Intrarater reproducibility was almost perfect for experts (mean ICC 0.972) and ranged from substantial to almost perfect for nonexperts (mean ICC 0.835). Interjudge agreement of the experts ranged from substantial to almost perfect (mean ICC 0.780), but interrater reliability of nonexperts ranged from substantial to good (mean 0.719). BRS shows for experts a high specificity and sensitivity and for nonexperts a low sensitivity and high specificity. Conclusions. The BRS is a simple, easy-to-carry-out, and accessible rating scale to locate pharyngeal retention on videofluoroscopic images with a good specificity and reproducibility for observers of different expertise levels.Nathalie Rommel, Charlotte Borgers, Dirk Van Beckevoort, Ann Goeleven, Eddy Dejaeger, and Taher I. Omar

    Thermodynamic properties of the two-dimensional S=1/2 Heisenberg antiferromagnet coupled to bond phonons

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    By applying a quantum Monte Carlo procedure based on the loop algorithm we investigate thermodynamic properties of the two-dimensional antiferromagnetic S=1/2 Heisenberg model coupled to Einstein phonons on the bonds. The temperature dependence of the magnetic susceptibility, mean phonon occupation numbers and the specific heat are discussed in detail. We study the spin correlation function both in the regime of weak and strong spin phonon coupling (coupling constants g=0.1, w=8J and g=2, w=2J, respectively). A finite size scaling analysis of the correlation length indicates that in both cases long range Neel order is established in the ground state.Comment: 10 pages, 13 figure

    Static Critical Behavior of the Spin-Freezing Transition in the Geometrically Frustrated Pyrochlore Antiferromagnet Y2Mo2O7

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    Some frustrated pyrochlore antiferromagnets, such as Y2Mo2O7, show a spin-freezing transition and magnetic irreversibilities below a temperature Tf similar to what is observed nonlinear magnetization measurements on Y2Mo2O7 that provide strong evidence that there is an underlying thermodynamic phase transition at Tf, which is characterized by critical exponents \gamma \approx 2.8 and \beta \approx 0.8. These values are typical of those found in random spin glasses, despite the fact that the level of random disorder in Y2Mo2O7 is immeasurably small.Comment: Latex file, calls for 4 encapsulated postscript figures (included). Submitted to Phys. Rev. Letters
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