Impacts of climate and farming management on maize yield in southern Tanzania

Climate is one of the major factors controlling agricultural productivity in Africa. Changes in meteorological variables such as rising temperatures, changes in precipitation and increase in atmospheric carbon dioxide levels affect crop production. The objective of this study was to evaluate the impacts of climate change and variability, and crop management on yield of maize ( Zea mays L. ) grown in the southern part of Tanzania. Using the Decision Support System for Agrotechnology Transfer Cropping System Model (DSSAT-CSM), a series of sensitivity experiments were conducted to evaluate the response of maize yields to a range of principal changes in rainfall and temperatures. The sensitivities were estimated under two management practices, one with traditional farming practices, and the other with application of external farm inputs. Dry-spells during the growing season caused yield losses of all cultivars of up to 43% for the prolonged dry-spells of 20 days. Increased rainfall intensity, during vegetative and reproductive stages, caused the decrease in yield of 5 and 2%, respectively. A 50-100% decrease in rainfall intensity during the growing season caused a loss of yields between 40-100%. Increased or decreased temperatures from the baseline values reduced or increased days to flowering and to physiological maturity, respectively. In addition, a decrease in temperature from the baseline values to 2 \ub0C had an overall impact of yields loss for all cultivars. However, yields increased with an increase of temperature by up to 2.5 \ub0C (UH6303 and H628) and 4.5 \ub0C (PAN691). Growing seasons with lower total rainfall (<50 mm) and temperature (<1\ub0C) from their climatological values, caused yield loss as much as 71 and 15%, respectively for PAN691 cultivar. Generally, the impacts depended on the management, cultivar, soil characteristics, magnitude, timing and duration of the stress.Le Climat est l\u2019un des facteurs majeurs contr\uf4lant la productivit\ue9 agricole en Afrique. Les changements de donn\ue9es m\ue9t\ue9orologiques tels que l\u2019\ue9l\ue9vation des temp\ue9ratures, variabilit\ue9 dans les pr\ue9cipitations et l\u2019augmentation du CO2 atmosph\ue9rique affecte la production agricole. L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer les impacts du changement climatique, de variabilit\ue9, et des pratiques agronomiques sur le rendement du ma\uefs ( Zea mays L. ) cultiv\ue9 dans la partie Sud de la Tanzanie. Une s\ue9rie d\u2019exp\ue9rimentations sur la sensibilit\ue9 a \ue9t\ue9 conduite au moyen du Syst\ue8me d\u2019appui \ue0 la prise de d\ue9cisions pour les transferts agro technologiques (DSSAT) afin d\u2019\ue9valuer la r\ue9ponse en terme de rendement de ma\uefs \ue0 une range de variabilit\ue9s majeures dans les pr\ue9cipitations et les temp\ue9ratures. Les sensibilit\ue9s ont \ue9t\ue9 estim\ue9es sous deux pratiques culturales, l\u2019une avec les pratiques de culture traditionnelle et l\u2019autre avec apport ext\ue9rieur d\u2019intrants agricoles. Des p\ue9riodes durant la saison culturales a caus\ue9 des pertes de rendement au niveau de tous les cultivars et ceci allant jusqu\u2019\ue0 43% pour des p\ue9riodes s\ue8ches prolong\ue9es de 20 jours. Les augmentations de l\u2019intensit\ue9 de pr\ue9cipitations durant les p\ue9riodes v\ue9g\ue9tative et reproductive ont caus\ue9 respectivement une diminution de 5 \ue0 2% du rendement. Une r\ue9duction de l\u2019intensit\ue9 des pr\ue9cipitations de 50-100% durant la saison culturale a caus\ue9 une perte de rendement entre 40-100%. L\u2019augmentation ou la diminution des temp\ue9ratures r\ue9duit ou augmente la date de floraison et de maturit\ue9. De plus, une diminution de temp\ue9rature de 2 \ub0C par rapport \ue0 la valeur moyenne a un impact significatif sur le rendement au niveau de tous les cultivars. N\ue9anmoins, le rendement augmente lorsque la temp\ue9rature augmente de 2.5 \ub0C (UH6303 and H628) et 4.5 \ub0C (PAN691). Les saisons culturales avec des pr\ue9cipitations globales (<50 mm) et (<1\ub0C) par rapport \ue0 leur valeurs climatologiques, ont caus\ue9 respectivement une perte de rendement aussi \ue9lev\ue9e que 71 et 15% pour le cultivar PAN691. De fa\ue7on g\ue9n\ue9rale, les impacts d\ue9pendent des pratiques culturales, du cultivar, des caract\ue9ristiques de sol, de la magnitude, du moment et de la dur\ue9e du stress

Cluster Monte Carlo and dynamical scaling for long-range interactions

Many spin systems affected by critical slowing down can be efficiently simulated using cluster algorithms. Where such systems have long-range interactions, suitable formulations can additionally bring down the computational effort for each update from O($N^2$) to O($N\ln N$) or even O($N$), thus promising an even more dramatic computational speed-up. Here, we review the available algorithms and propose a new and particularly efficient single-cluster variant. The efficiency and dynamical scaling of the available algorithms are investigated for the Ising model with power-law decaying interactions.Comment: submitted to Eur. Phys. J Spec. Topic

Helicity Analysis of Semileptonic Hyperon Decays Including Lepton Mass Effects

Using the helicity method we derive complete formulas for the joint angular decay distributions occurring in semileptonic hyperon decays including lepton mass and polarization effects. Compared to the traditional covariant calculation the helicity method allows one to organize the calculation of the angular decay distributions in a very compact and efficient way. In the helicity method the angular analysis is of cascade type, i.e. each decay in the decay chain is analyzed in the respective rest system of that particle. Such an approach is ideally suited as input for a Monte Carlo event generation program. As a specific example we take the decay $\Xi^0 \to \Sigma^+ + l^- + \bar{\nu}_l$ ($l^-=e^-, \mu^-$) followed by the nonleptonic decay $\Sigma^+ \to p + \pi^0$ for which we show a few examples of decay distributions which are generated from a Monte Carlo program based on the formulas presented in this paper. All the results of this paper are also applicable to the semileptonic and nonleptonic decays of ground state charm and bottom baryons, and to the decays of the top quark.Comment: Published version. 40 pages, 11 figures included in the text. Typos corrected, comments added, references added and update

Branch-and-lift algorithm for deterministic global optimization in nonlinear optimal control

This paper presents a branch-and-lift algorithm for solving optimal control problems with smooth nonlinear dynamics and potentially nonconvex objective and constraint functionals to guaranteed global optimality. This algorithm features a direct sequential method and builds upon a generic, spatial branch-and-bound algorithm. A new operation, called lifting, is introduced, which refines the control parameterization via a Gram-Schmidt orthogonalization process, while simultaneously eliminating control subregions that are either infeasible or that provably cannot contain any global optima. Conditions are given under which the image of the control parameterization error in the state space contracts exponentially as the parameterization order is increased, thereby making the lifting operation efficient. A computational technique based on ellipsoidal calculus is also developed that satisfies these conditions. The practical applicability of branch-and-lift is illustrated in a numerical example. © 2013 Springer Science+Business Media New York

Tratamiento de regeneración endodóntica en pulpa vital y necrótica, utilizando fibrina rica en plaquetas y Biodentine: reporte de caso

Endodontic regeneration is an inductive and reparative biological treatment indicated to replace cell damage at the level of the dentinopulp complex. The objective of this study is to report a case of Endodontic Regenerative Therapy, in young permanent first molars, in a 10-year-old patient, using platelet-rich fibrin and Biodentine, applying two different protocols for combined diagnoses of irreversible pulpitis and pulp necrosis. The patient attended consultation due to extensive carious lesions. Clinical and imaging evaluations (X-rays and Cone Beam) were performed. The protocol in the necrotic canal consisted of disinfection with a bi-antibiotic paste and placement of a second-generation autologous scaffold matrix, made of biodegradable platelet-rich fibrin which is also , biocompatible and therefore without risk of immune rejection. The protocol in the canals with irreversible pulpitis consisted in a complete pulpotomy and placement of Biodentine calcium silicate cement, a material considered as first choice for pulp-conserving treatments, with properties similar to dentin. Eight weeks after the end of the treatment, a clinical control was conducted revealing an asymptomatic chart and negative palpation without the presence of fistula or abscess. This result indicated regeneration of the pulp tissues and success of the applied protocols. Controls will be carried out at 6, 12 and 18 months. Conclusion: The application of endodontic regenerative treatments, as performed in this reported case, is a favorable and innovative option to preserve, restore or replace the dental pulp. In comparison with conventional treatments, this procedure allows to return pulp functionality, complete development of the root, thickening of the dentinal walls and closure of the apical foramen of young permanent teeth affected by pulp pathologies. It is important that regenerative therapies are publicized and applied by dental professionalsLa regeneración endodóntica es un tratamiento inductivo y reparativo con bases biológicas, indicado para reemplazar los daños celulares a nivel del complejo dentinopulpar. El objetivo de este estudio es reportar un caso de Terapia Regenerativa Endodóntica, en primeros molares permanentes jóvenes, en un paciente de 10 años, a través del uso de fibrina rica en plaquetas y Biodentine, se aplicaron dos protocolos diferentes por diagnósticos combinados de pulpitis irreversible y necrosis pulpar. El paciente acude a consulta por presentar lesiones cariosas extensas; se realizaron evaluaciones clínicas e imagenológicas (radiografías y Cone Beam), el protocolo en el conducto necrótico consistió en la desinfección con pasta biantibiótica y la colocación de una matriz de andamiaje autóloga de segunda generación, elaborada de fibrina rica en plaquetas que es biodegradable, biocompatible y no existe riesgo de rechazo inmunológico. El protocolo en los conductos con pulpitis irreversibles consistió en pulpotomía total y colocación de cemento de silicato de calcio Biodentine, el cual se considera el material de primera elección para los tratamientos conservadores de la pulpa, con propiedades similares a la dentina. A 8 semanas de finalizado el tratamiento se realizó control clínico y el paciente mostró un cuadro asintomático, palpación negativa sin presencia de fístula o absceso lo que podría indicar regeneración de los tejidos pulpares y éxito de los protocolos aplicados. Los siguientes controles se realizán a los 6, 12 y 18 meses. Conclusión: la aplicación de los tratamientos regenerativos endodónticos como se realizó en el caso reportado, es una opción favorable e innovadora para preservar, restaurar o sustituir la pulpa dental, que en comparación con los tratamientos convencionales nos permiten devolver la funcionalidad pulpar, finalizar el desarrollo radicular, engrosamiento de las paredes dentinales y cierre del foramen apical de dientes permanentes jóvenes que han sido afectados por patologías pulpares. Es importante que las terapias regenerativas sean divulgadas y aplicadas por los profesionale

Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio