997 research outputs found
Population Structure Of Jatropha And Its Implication For The Breeding Program
Jatropha (Jatropha curcas L.) has potential as an oilseed crop that requires the development of technology for its exploitation. The objective of this study was to assess the population structure and the genetic diversity in jatropha accessions at a global level using simple sequence repeat (SSR) molecular markers. Jatropha accessions (N = 109) from 10 countries were genotyped using 10 SSR markers. The results showed a low level of genetic diversity among 92 accessions originating from India, Mozambique, Ethiopia, Tanzania, Brazil, Honduras, and Indonesia, which were grouped in one cluster. In contrast, accessions from Mexico and Costa Rica showed high level of genetic variability. These accessions may be used to increase the genetic diversity of jatropha in the breeding populations. The study also showed the need of collecting activity from the center of diversity (Mexico and Costa Rica) to aggregate the genetic diversity in the international collections of jatropha. © FUNPEC-RP.15
Spin-phonon coupling in the incommensurate magnetic ordered phase of orthorhombic TmMnO<sub>3</sub>
International audienceThe search for materials with strong magnetoelectric coupling has been intense since interesting properties were discovered in the perovskite TbMnO 3. Among the manganese-based perovskite family (RMnO 3), magnetic and electric orders coexist in the orthorhombic phase of the distorted perovskite TmMnO 3. The antiferromagnetic phase induces ferroelectricity, leading to type-II multiferroic behavior. Although the temperature-dependent behavior of the Raman-active phonons of other members of the orthorhombic RMnO 3 family was already reported, little information about orthorhombic TmMnO 3 has been published. In this paper, bulk samples of orthorhombic TmMnO 3 were obtained through HPHT treatment. Structural and magnetic properties of the synthesized samples were analyzed for phase con rmation. Temperature-dependent Raman spectra of bulk orthorhombic TmMnO 3 revealed weak spin-phonon coupling in the incommensurate antiferromagnetic ordered phase around 44 K. Raman spectra are also sensitive to the magnetic transition from the incommensurate to Etype antiferromagnetic phase, where the frequency renormalization due to the spin-phonon coupling vanishes. This feature shows the existence of an orbital-spin-phonon coupling based on the magnetic ordering of the lowtemperature phase
-Classical orthogonal polynomials: A general difference calculus approach
It is well known that the classical families of orthogonal polynomials are
characterized as eigenfunctions of a second order linear
differential/difference operator. In this paper we present a study of classical
orthogonal polynomials in a more general context by using the differential (or
difference) calculus and Operator Theory. In such a way we obtain a unified
representation of them. Furthermore, some well known results related to the
Rodrigues operator are deduced. A more general characterization Theorem that
the one given in [1] and [2] for the q-polynomials of the q-Askey and Hahn
Tableaux, respectively, is established. Finally, the families of Askey-Wilson
polynomials, q-Racah polynomials, Al-Salam & Carlitz I and II, and q-Meixner
are considered.
[1] R. Alvarez-Nodarse. On characterization of classical polynomials. J.
Comput. Appl. Math., 196:320{337, 2006. [2] M. Alfaro and R. Alvarez-Nodarse. A
characterization of the classical orthogonal discrete and q-polynomials. J.
Comput. Appl. Math., 2006. In press.Comment: 18 page
Pericardial adipose tissue, cardiac structures, and cardiovascular risk factors in school-age children
Aims We examined the associations of pericardial adipose tissue with cardiac structures and cardiovascular risk factors in children.Methods and results We performed a cross-sectional analysis in a population-based cohort study among 2892 children aged 10 years (2404 normal weight and 488 overweight/obese). Pericardial adipose tissue mass was estimated by magnetic resonance imaging (MRI) and indexed on height 3 . Left ventricular mass (LVM) and left ventricular mass-to-volume ratio (LMVR) were estimated by cardiac MRI. Cardiovascular risk factors included android adipose tissue percentage obtained by Dual-energy X-ray absorptiometry, blood pressure and glucose, insulin, cholesterol, and triglycerides concentrations. Adverse outcomes were defined as values above the 75 percentile. Median pericardial adipose tissue index was 3.6 (95% range 1.6-7.1) among normal weight and 4.7 (95% range 2.0-8.9) among overweight children. A one standard deviation (1 SD) higher pericardial adipose tissue index was associated with higher LMVR [0.06 standard deviation scores, 95% confidence interval (CI) 0.02-0.09], increased odds of high android adipose tissue [odd ratio (OR) 2.08, 95% CI 1.89-2.29], high insulin concentrations (OR 1.17, 95% CI 1.06-1.30), an atherogenic lipid profile (OR 1.22, 95% CI 1.11-1.33), and clustering of cardiovascular risk factors (OR 1.56, 95% CI 1.36-1.79). Pericardial adipose tissue index was not associated with LVM, blood pressure, and glucose concentrations. The associations showed largely the same directions but tended to be weaker among normal weight than among overweight children.Conclusion Pericardial adipose tissue is associated with cardiac adaptations and cardiovascular risk factors already in childhood in both normal weight and overweight children.Developmen
The PKC, HOG and Ca2+ signalling pathways co-ordinately regulate chitin synthesis in Candida albicans
Open Access via PMC2649417Peer reviewedPublisher PD
Predictive Value of Ov16 Antibody Prevalence in Different Subpopulations for Elimination of African Onchocerciasis
The World Health Organization currently recommends assessing elimination of onchocerciasis by testing whether Ov16 antibody prevalence in children aged 0-9 years is below 0.1%. However, the certainty of evidence for this recommendation is considered to be low. We used the established ONCHOSIM model to investigate the predictive value of different Ov16-antibody prevalence thresholds in various age groups for elimination of onchocerciasis in a variety of endemic settings and for various mass drug administration scenarios. According to our simulations, the predictive value of Ov16 antibody prevalence for elimination depends highly on the precontrol epidemiologic situation, history of mass drug administration, the age group that is sampled, and the chosen Ov16-antibody prevalence threshold. The Ov16 antibody prevalence in children aged 5-14 years performs best in predicting elimination. Appropriate threshold values for this age group start at 2.0% for very highly endemic areas; for lower-endemic areas, even higher threshold values are safe to use. Guidelines can be improved by sampling school-aged children, which also is operationally more feasible than targeting children under age 10 years. The use of higher threshold values allows sampling of substantially fewer children. Further improvement can be achieved by taking a differentiated sampling approach based on precontrol endemicity
- …