14 research outputs found
Green Agricultural Productivity Growth and Convergence in sub-Saharan Africa
This study analyzes the dynamics of green agricultural productivity growth through SSA countries. As subsidiary objectives: (i) to estimate efficiency levels of agricultural production system in SSA countries (ii) to estimate green agricultural productivity index through SSA countries (iii) and then to determine path nature of the green agricultural productivity index trough time and SSA countries. The methodology used to assess the degree of convergence in output per worker is based on the cointégration analysis, which recognizes that labour productivity is generally a non-stationary time series and convergence is a gradual process. First of all, we consider a decomposition of the growth in labour (green) productivity in terms of (1) efficiency change (2) technical change (3) (physical) capital accumulation and (4) growth in human capital. Then, a semi-parametric approach will be used to construct the best production practice frontier for a sample of SSA, and compute Malmquist productivity indexes and their decomposition into the underlying productivity components for each country. Finally, we will assess the individual contribution of the various components to the convergence in labour productivity
Burden of visceral leishmaniasis in villages of eastern gedaref state, Sudan: an exhaustive cross-sectional survey.
Since December 2009, Médecins Sans Frontières has diagnosed and treated patients with visceral leishmaniasis (VL) in Tabarak Allah Hospital, eastern Gedaref State, one of the main endemic foci of VL in Sudan. A survey was conducted to estimate the VL incidence in villages around Tabarak Allah
Calibration test of PET scanners in a multi-centre clinical trial on breast cancer therapy monitoring using 18F-FLT.
UNLABELLED: A multi-centre trial using PET requires the analysis of images acquired on different systems We designed a multi-centre trial to estimate the value of 18F-FLT-PET to predict response to neoadjuvant chemotherapy in patients with newly diagnosed breast cancer. A calibration check of each PET-CT and of its peripheral devices was performed to evaluate the reliability of the results.
MATERIAL AND METHODS: 11 centres were investigated. Dose calibrators were assessed by repeated measurements of a 68Ge certified source. The differences between the clocks associated with the dose calibrators and inherent to the PET systems were registered. The calibration of PET-CT was assessed with an homogeneous cylindrical phantom by comparing the activities per unit of volume calculated from the dose calibrator measurements with that measured on 15 Regions of Interest (ROIs) drawn on 15 consecutive slices of reconstructed filtered back-projection (FBP) images. Both repeatability of activity concentration based upon the 15 ROIs (ANOVA-test) and its accuracy were evaluated.
RESULTS: There was no significant difference for dose calibrator measurements (median of difference -0.04%; min = -4.65%; max = +5.63%). Mismatches between the clocks were less than 2 min in all sites and thus did not require any correction, regarding the half life of 18F. For all the PET systems, ANOVA revealed no significant difference between the activity concentrations estimated from the 15 ROIs (median of difference -0.69%; min = -9.97%; max = +9.60%).
CONCLUSION: No major difference between the 11 centres with respect to calibration and cross-calibration was observed. The reliability of our 18F-FLT multi-centre clinical trial was therefore confirmed from the physical point of view. This type of procedure may be useful for any clinical trial involving different PET systems
Évaluation et gestion du risque radioactif suite au décès d’un patient ayant reçu une dose thérapeutique d’iode-131 dans le cadre d’un traitement en radiothérapie métabolique
Un patient traité à la méta-iodobenzylguanidine (mIBG) marquée à l’iode-131 pour un phéochromocytome malin est décédé trois heures après injection. Afin de minimiser les risques liés à la radioactivité, la décision de garder la dépouille pendant seize jours a été prise. Le présent travail présente les niveaux d’exposition des différentes personnes étant intervenues dans la prise en charge de la patiente depuis son hospitalisation jusqu’à son enterrement ainsi que les dispositions prises pour éviter toute contamination et dissémination radioactive
Isothermal section at 600\ua0\ub0C of the Yb 12Pd 12Sn system (Pd\ua0 64\ua075 at.%)
Phase equilibria in the Yb 12Pd 12Sn ternary system at 600 \ub0C were established in the Pd 64 75 at.% concentration range employing X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe micro-analysis (EPMA). Besides the known intermetallic compounds, three new ternary intermetallics were revealed in the system, together with homogeneity ranges into the ternary field for some binary phases. Magnetic properties for the new compounds were investigated revealing stable Yb states Yb3+ for Yb3Pd4Sn13 and Yb2+ for Yb5Pd39Sn56, whereas for Yb13Pd40Sn31 an unstable valency of Yb is suggested
Structural and physical properties of the new stannide Yb3Pd4Sn13
Among the new discovered intermetallics in the Yb-Pd-Sn system, the cubic phase Yb3Pd4Sn13, with a lattice parameter of 0.9743(5) nm, emerges as a new member of the R3T4Sn13 family (R = rare earth element, T = transition metal) crystallizing in the Yb3Rh4Sn13-structure type. The effective magnetic moment \u3bceff = 1:84 \u3bcB/Yb is strongly reduced. Moreover, measurements of magnetic properties, specific heat and resistivity indicate superconductivity below 2.4 K. This compound is found to exhibit a strongly enhanced electronic specific heat at low temperature from which we infer a possible low-lying magnetic phase transition or other source of magnetic entropy
COVID‐19 impact on SADC labour markets: Evidence from high‐frequency data and other sources
Plasmon-Exciton Interactions in a Core-Shell Geometry: From Enhanced Absorption to Strong Coupling
We present a detailed Mie theory, finite-difference time-domain, and quasi-static study of plasmon-exciton interactions in a spherical core shell geometry. In particular, we report absorption, scattering, and extinction cross sections of a hybrid core-shell system and identify several important interaction regimes that are determined by the electromagnetic field enhancement and the oscillator strength of electronic excitations. We assign these regimes to enhanced-absorption, exciton-induced transparency and strong coupling, depending on the nature of the observed spectra of the coupled plasmon-exciton resonances. We also show the relevance of performing single-particle absorption or extinction measurements in addition to scattering to validate the interaction regime. Furthermore, at relatively high, yet realistic oscillator strengths we observe emergence of a third mode, which is not predicted by a classical coupled harmonic oscillator model and is attributed to the geometrical resonance of the structure as a whole