Common bean (Phaseolus vulgaris L.) landraces in Catalonia, a Mesoamerican germplasm hotspot to be preserved

[EN] Several landraces of common bean with high organoleptic value have resisted the rapid expansion of improved cultivars in Catalonia, in north-eastern Spain. To establish strategies for their preservation and use, we employed RAPD and AFLP markers to investigate the genetic variability within 15 landraces and to identify their original gene pools. A higher percentage of Mesoamerican landraces was found in Catalonia (40%) than in the rest of the Iberian Peninsula, or in Europe (approx. 20%). This is probably due to the exclusion of Catalonia from early trade with the American colonies and stronger commercial links with the Caribbean during the nineteenth century. Our results confirm that Catalan consumers prefer white-seeded common bean varieties of Mesoamerican origin. The landrace ‘Castellfollit del Boix’ showed 69.6% polymorphic RAPD primers, with 53.2% polymorphic bands, while at the other extreme ‘Tavella Brisa’ showed 47.8% polymorphic primers with 25.3% polymorphic bands. An AFLP approach yielded similar results. The high genetic variability found in ‘Castellfollit del Boix’, one of the landraces most threatened, suggests a considerable amount of introgression from improved inbreds.This work was supported by a research grant from CICYT (AGL0035-01).Sanchez, E.; Sifres Cuerda, AG.; Casañas, F.; Nuez Viñals, F. (2007). Common bean (Phaseolus vulgaris L.) landraces in Catalonia, a Mesoamerican germplasm hotspot to be preserved. Journal of Horticultural Science. 82(4):529-534. https://doi.org/10.1080/14620316.2007.11512269S529534824Rodrigo, A. P. (2000).Caracterización Morfoagronómica y Bioquímica del Germoplasma de la Judía Común (Phaseolus vulgarisL.) de España.Ph.D. Thesis, Universidad de Santiago de Compostela, Santiago, Spain. 251 pp

Modeling of Dislocation Structures in Materials

A phenomenological model of the evolution of an ensemble of interacting dislocations in an isotropic elastic medium is formulated. The line-defect microstructure is described in terms of a spatially coarse-grained order parameter, the dislocation density tensor. The tensor field satisfies a conservation law that derives from the conservation of Burgers vector. Dislocation motion is entirely dissipative and is assumed to be locally driven by the minimization of plastic free energy. We first outline the method and resulting equations of motion to linear order in the dislocation density tensor, obtain various stationary solutions, and give their geometric interpretation. The coupling of the dislocation density to an externally imposed stress field is also addressed, as well as the impact of the field on the stationary solutions.Comment: RevTeX, 19 pages. Also at http://www.scri.fsu.edu/~vinals/jeff1.p

El mercado de trabajo español y la Unión Económica y Monetaria europea

En este articulo se presenta un analisis de la situacion del mercado de trabajo español, prestando especial atencion a aquellos aspectos que pueden condicionar los beneficios de la integracion de la economia española en la Union Economica y Monetaria (UEM). Este analisis comienza con una descripcion de las principales diferencias entre algunos indicadores del comportamiento del mercado de trabajo en España y en el resto de la Union Europea (UE). A continuacion se identifican las principales causas por las que la tasa de desempleo española es aproximadamente el doble de la tasa de desempleo media de la UE, asi como los aspectos institucionales del mercado de trabajo español que estan detras de dichas causas. La ultima parte de este trabajo analiza, a la luz de la evidencia anterior, el impacto probable de la UEM sobre el desempleo en España a corto y largo plazo. Contiene bibliografia, graficos y cuadros estadisticos. (jvi) (jfj) (mac

A phenomenological model of weakly damped Faraday waves and the associated mean flow

A phenomenological model of parametric surface waves (Faraday waves) is introduced in the limit of small viscous dissipation that accounts for the coupling between surface motion and slowly varying streaming and large scale flows (mean flow). The primary bifurcation of the model is to a set of standing waves (stripes, given the functional form of the model nonlinearities chosen here). Our results for the secondary instabilities of the primary wave show that the mean flow leads to a weak destabilization of the base state against Eckhaus and Transverse Amplitude Modulation instabilities, and introduces a new longitudinal oscillatory instability which is absent without the coupling. We compare our results with recent one dimensional amplitude equations for this system systematically derived from the governing hydrodynamic equations.Comment: Complete paper with embedded figures (PostScript, 3 Mb) http://www.csit.fsu.edu/~vinals/mss/jmv1.p

Feasibility of extended ultrasound examination of the fetal brain between 24 and 37 weeks’ gestation in low-risk pregnancies

Objectives: To assess the feasibility of identifying fetal brain structures and anatomic landmarks included in the anterior complex (AC) and posterior complex (PC), as well as the proximal hemisphere (PH). Methods: This was a prospective observational multicenter study of healthy pregnant women evaluated by ultrasound screening at 24 to 36 + 6 weeks' gestation. Six physicians performed transabdominal ultrasound, to obtain the planes required to visualize the AC, PC, and PH. Blind analysis by an expert and non-expert operator in fetal neurosonography was used to assess the structures included in each plane view. Results: In the population studied (n=366), structure detection rates for AC were over 95 %, with an agreement of 96 % when comparing expert and non-expert examiners. Visualization of the corpus callosum crossing the midline was detected in over 97 and 96 % of cases for the AC and PC, respectively, with an agreement of over 96 %. The PH plane, particularly through the posterior access via the mastoid fontanelle, enabled visualization of the proximal anatomical structures in almost 95 % of cases. Detection of the corpus callosum through the AC and PC, both proximal/distal germinal matrix (AC) and proximal Sylvian fissure through the anterior access (PH) in the 24-25 + 6, 26-31 + 6 and 32-36 + 6 weeks' gestation groups were successful in over 96 % of cases with high level of agreement. Conclusions: Inclusion of AC, PC, and PH later in pregnancy proves feasible with a high level of agreement between both expert and non-expert operators.info:eu-repo/semantics/publishedVersio

Adiabatic reduction near a bifurcation in stochastically modulated systems

We re-examine the procedure of adiabatic elimination of fast relaxing variables near a bifurcation point when some of the parameters of the system are stochastically modulated. Approximate stationary solutions of the Fokker-Planck equation are obtained near threshold for the pitchfork and transcritical bifurcations. Stochastic resonance between fast variables and random modulation may shift the effective bifurcation point by an amount proportional to the intensity of the fluctuations. We also find that fluctuations of the fast variables above threshold are not always Gaussian and centered around the (deterministic) center manifold as was previously believed. Numerical solutions obtained for a few illustrative examples support these conclusions.Comment: RevTeX, 19 pages and 16 figure

Fluctuations and correlations in hexagonal optical patterns

We analyze the influence of noise in transverse hexagonal patterns in nonlinear Kerr cavities. The near field fluctuations are determined by the neutrally stable Goldstone modes associated to translational invariance and by the weakly damped soft modes. However these modes do not contribute to the far field intensity fluctuations which are dominated by damped perturbations with the same wave vectors than the pattern. We find strong correlations between the intensity fluctuations of any arbitrary pair of wave vectors of the pattern. Correlation between pairs forming 120 degrees is larger than between pairs forming 180 degrees, contrary to what a naive interpretation of emission in terms of twin photons would suggest.Comment: 10 pages, 13 figure

Shear induced grain boundary motion for lamellar phases in the weakly nonlinear regime

We study the effect of an externally imposed oscillatory shear on the motion of a grain boundary that separates differently oriented domains of the lamellar phase of a diblock copolymer. A direct numerical solution of the Swift-Hohenberg equation in shear flow is used for the case of a transverse/parallel grain boundary in the limits of weak nonlinearity and low shear frequency. We focus on the region of parameters in which both transverse and parallel lamellae are linearly stable. Shearing leads to excess free energy in the transverse region relative to the parallel region, which is in turn dissipated by net motion of the boundary toward the transverse region. The observed boundary motion is a combination of rigid advection by the flow and order parameter diffusion. The latter includes break up and reconnection of lamellae, as well as a weak Eckhaus instability in the boundary region for sufficiently large strain amplitude that leads to slow wavenumber readjustment. The net average velocity is seen to increase with frequency and strain amplitude, and can be obtained by a multiple scale expansion of the governing equations

New Insights into the Anterior Complex

Objective: To introduce visualization of the germinal matrix (GM), external angle of the frontal horn, and periventricular white matter while evaluating the anterior complex (AC) during basic ultrasound assessment of the fetal brain. Case presentations: This is a retrospective observational study of healthy women with singleton pregnancies, with no increased risk of fetal central nervous system anomalies, attending routine ultrasound screening at 20-32 weeks' gestation. Seventeen cases are presented in which an abnormal aspect of the GM or external angle of the frontal horn or periventricular white matter on AC evaluation has allowed a prenatal diagnosis of peri-intraventricular hemorrhage, subependymal cysts, connatal cysts, periventricular venous hemorrhagic infarction, and white matter injury. Conclusion: An extended AC evaluation could significantly improve the -diagnosis of hemorrhagic/cystic/hypoxic-ischemic lesions during the performance of a basic ultrasound study of the fetal brain.info:eu-repo/semantics/publishedVersio

Numerical Confirmation of Late-time t^{1/2} Growth in Three-dimensional Phase Ordering

Results for the late-time regime of phase ordering in three dimensions are reported, based on numerical integration of the time-dependent Ginzburg-Landau equation with nonconserved order parameter at zero temperature. For very large systems ($700^3$) at late times, $t \ge 150,$ the characteristic length grows as a power law, $R(t) \sim t^n$, with the measured $n$ in agreement with the theoretically expected result $n=1/2$ to within statistical errors. In this time regime $R(t)$ is found to be in excellent agreement with the analytical result of Ohta, Jasnow, and Kawasaki [Phys. Rev. Lett. {\bf 49}, 1223 (1982)]. At early times, good agreement is found between the simulations and the linearized theory with corrections due to the lattice anisotropy.Comment: Substantially revised and enlarged, submitted to PR