Interaktionen zwischen Genotyp und Ort sind ein Vorteil von lokaler Züchtung von Ackerbohnen (Vicia faba L.)

Organic farming is based on low productivity environments regarding the restricted supply of inputs. Thus, to maximize the response of selection, the local breeding approach was put forward for organic agriculture. To analyse this approach, efforts of organic farmers and scientists were combined in a pertinent, participatory breeding approach using spring faba bean as crop. A set of genotypes with different levels of heterozygosity and heterogeneity were tested in four organic farms and one conventional location. Results for grain yield showed that the genotype-location interaction was highly significant and contributed to a large extent to the yield variation. The findings indicated that indeed local breeding programs could give greater genetic gains for organic cropping systems than traditional, formal plant breeding programs

Heterogeneidad individual e identificabilidad en modelos de captura–recaptura

Individual heterogeneity in detection probabilities is a far more serious problem for capture–recapture modeling than has previously been recognized. In this note, I illustrate that population size is not an identifiable parameter under the general closed population mark–recapture model Mh. The problem of identifiability is obvious if the population includes individuals with pi = 0, but persists even when it is assumed that individual detection probabilities are bounded away from zero. Identifiability may be attained within parametric families of distributions for pi, but not among parametric families of distributions. Consequently, in the presence of individual heterogeneity in detection probability, capture–recapture analysis is strongly model dependent.La heterogeneidad individual en las probabilidades de detección representa un problema para la modelación del procedimiento de captura–recaptura mucho más serio de lo que previamente se había reconocido. En este artículo se demuestra que el tamaño de la población no constituye un parámetro identificable en el modelo general Mh que emplea técnicas de marcaje–recaptura de poblaciones cerradas. El problema de la identificabilidad resulta evidente si la población incluye individuos con pi = 0, pero sigue persistiendo aun cuando se presuponga que las probabilidades de detección individual se han alejado de cero. La identificabilidad puede conseguirse en familias paramétricas de distribuciones para pi, pero no entre familias paramétricas de distribuciones. Por consiguiente, si se da una heterogeneidad individual en la probabilidad de detección, el análisis de captura–recaptura depende considerablemente del modelo considerado

Modelos jerárquicos de marcaje–recaptura: un marco para la inferencia de procesos demográficos

The development of sophisticated mark–recapture models over the last four decades has provided fundamental tools for the study of wildlife populations, allowing reliable inference about population sizes and demographic rates based on clearly formulated models for the sampling processes. Mark–recapture models are now routinely described by large numbers of parameters. These large models provide the next challenge to wildlife modelers: the extraction of signal from noise in large collections of parameters. Pattern among parameters can be described by strong, deterministic relations (as in ultrastructural models) but is more flexibly and credibly modeled using weaker, stochastic relations. Trend in survival rates is not likely to be manifest by a sequence of values falling precisely on a given parametric curve; rather, if we could somehow know the true values, we might anticipate a regression relation between parameters and explanatory variables, in which true value equals signal plus noise. Hierarchical models provide a useful framework for inference about collections of related parameters. Instead of regarding parameters as fixed but unknown quantities, we regard them as realizations of stochastic processes governed by hyperparameters. Inference about demographic processes is based on investigation of these hyperparameters. We advocate the Bayesian paradigm as a natural, mathematically and scientifically sound basis for inference about hierarchical models. We describe analysis of capture–recapture data from an open population based on hierarchical extensions of the Cormack–Jolly–Seber model. In addition to recaptures of marked animals, we model first captures of animals and losses on capture, and are thus able to estimate survival probabilities (i.e., the complement of death or permanent emigration) and per capita growth rates f (i.e., the sum of recruitment and immigration rates). Covariation in these rates, a feature of demographic interest, is explicitly described in the model.El desarrollo de sofisticados modelos de marcaje–recaptura a lo largo de las últimas cuatro décadas ha proporcionado herramientas fundamentales para el estudio de poblaciones de fauna silvestre, lo que ha permitido inferir con fiabilidad los tamaños poblacionales y las tasas demográficas a partir de modelos claramente formulados para procesos estocásticos. En la actualidad, los modelos de marcaje–recaptura se describen de forma rutinaria mediante una extensa serie de parámetros. Dichos modelos representan el siguiente reto al que deberán enfrentarse los modeladores de fauna silvestre: discriminar las señales del ruido en amplias series de parámetros. La pauta que encontramos en los parámetros puede describirse mediante sólidas relaciones deterministas (como en los modelos ultraestructurales), pero resulta más flexible y creíble si se modela utilizando relaciones estocásticas más débiles. No es probable que la tendencia en las tasas de supervivencia se manifieste por una secuencia de valores hallados concretamente en una curva paramétrica dada; por ello, si pudiéramos llegar a conocer los valores reales, podríamos prever una relación de regresión entre parámetros y variables explicativas, de forma que el valor verdadero equivaldría a la señal más el ruido. Los modelos jerárquicos proporcionan un marco útil para la inferencia acerca de series de parámetros relacionados. Así, en lugar de interpretar los parámetros como cantidades fijas, pero desconocidas, los interpretamos como realizaciones de procesos estocásticos regidos por hiperparámetros. La inferencia acerca de los procesos demográficos se basa en la investigación de dichos hiperparámetros. Por este motivo, defendemos el paradigma bayesiano como una base natural, matemática y científicamente sólida para la inferencia acerca de modelos jerárquicos. En el presente estudio describimos el análisis de datos de captura–recaptura obtenidos a partir de una población abierta basada en ampliaciones jerárquicas del modelo de Cormack–Jolly–Seber. Además de las recapturas de animales marcados, también modelamos las primeras capturas de animales y de pérdidas durante la captura, lo que nos permitió estimar las probabilidades de supervivencia de (es decir, el complemento de la muerte o la emigración permanente) y las tasas de crecimiento per cápita f (es decir, la suma de las tasas de reclutamiento y de migración). En el modelo se describe explícitamente la covariación en estas tasas, que constituye una característica de interés demográfico

Providing assistance to incarcerated fathers who have child support obligations can help their post-release community reintegration

Among the growing discussions about race, justice, inequality and incarceration there has been a greater concern over the financial obligations placed on those who are convicted of crimes. In new research, Caterina G. Roman and Nathan W. Link examine the effects of ongoing child support payments on incarcerated fathers after their release, finding that less than a third had their payments changed whilst in prison, and that over 90 percent had payments in arrears after release. They argue that the multiple social services involved with incarcerated fathers both pre and post imprisonment need to provide more coordinated support so that child support orders do not become unwieldy, burdensome arrears

Precision Counting of Small Black Holes

It has recently been proposed that a class of supersymmetric higher-derivative interactions in N=2 supergravity may encapsulate an infinite number of finite size corrections to the microscopic entropy of certain supersymmetric black holes. If this proposal is correct, it allows one to probe the string theory description of black-hole micro-states to far greater accuracy than has been possible before. We test this proposal for ``small'' black holes whose microscopic degeneracies can be computed exactly by counting the corresponding perturbative BPS states. We also study the ``black hole partition sum'' using general properties of of BPS degeneracies. This complements and extends our earlier work in hep-th/0502157Comment: 103 pages, uses JHEP3.cl

Evidence for Heating of Neutron Stars by Magnetic Field Decay

We show the existence of a strong trend between neutron star surface temperature and the dipolar component of the magnetic field extending through three orders of field magnitude, a range that includes magnetars, radio-quiet isolated neutron stars, and many ordinary radio pulsars. We suggest that this trend can be explained by the decay of currents in the crust over a time scale of few Myr. We estimate the minimum temperature that a NS with a given magnetic field can reach in this interpretation.Comment: 4 pages, 1 figures, version accepted for publication in Phys. Rev. Let

Field-induced paramagnons at the metamagnetic transition in Ca1.8Sr0.2RuO4

The magnetic excitations in Ca1.8Sr0.2RuO4 were studied across the metamagnetic transition and as a function of temperature using inelastic neutron scattering. At low temperature and low magnetic field the magnetic response is dominated by a complex superposition of incommensurate antiferromagnetic fluctuations. Upon increasing the magnetic field across the metamagnetic ransition, paramagnon and finally well-defined magnon scattering is induced, partially suppressing the incommensurate signals. The high-field phase in Ca1.8Sr0.2RuO4 has, therefore, to be considered as an intrinsically ferromagnetic state stabilized by the magnetic field

Comparison of fibre optical measurements and discrete element simulations for the study of granulation in a spout fluidized bed

Spout fluidized beds are frequently used for the production of granules or particles through granulation. The products find application in a large variety of applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized beds have a number of advantageous properties, such as a high mobility of the particles, which prevents undesired agglomeration and yields excellent heat transfer properties. The particle growth mechanism in a spout fluidized bed as function of particle-droplet interaction has a profound influence on the particle morphology and thus on the product quality. Nevertheless, little is known about the details of the granulation process. This is mainly due to the fact that the granulation process is not visually accessible. In this work we use fundamental, deterministic models to enable the detailed investigation of granulation behaviour in a spout fluidized bed. A discrete element model is used describing the dynamics of the continuous gas-phase and the discrete droplets and particles. For each element momentum balances are solved. The momentum transfer among each of the three phases is described in detail at the level of individual elements. The results from the discrete element model simulations are compared with local measurements of particle volume fractions as well as particle velocities by using a novel fibre optical probe in a fluidized bed of 400 mm I.D. Simulations and experiments were carried out for three different cases using Geldart B type aluminium oxide particles: a freely bubbling fluidized bed; a spout fluidized bed without the presence of droplets and a spout fluidized bed with the presence of droplets. It is demonstrated how the discrete element model can be used to obtain information about the interaction of the discrete phases, i.e. the growth zone in a spout fluidized bed. Eventually this kind of information can be used to obtain closure information required in more coarse grained models

Analysis, design, and test of acoustic treatment in a laboratory inlet duct

A suppression prediction program based on the method of modal analysis for spinning mode propagation in a circular duct was used in the analytical design of optimized, multielement, Kevlar bulk-absorber treatment configurations for an inlet duct. The NASA-Langley ANRL anechoic chamber using the spinning mode synthesizer as a sound source was used to obtain in-duct spinning mode measurements, radial mode measurements, and far-field traverses, as well as aerodynamic measurements. The measured suppression values were compared to predicted values, using the in-duct, forward-traveling, radial-mode content as the source for the prediction. The performance of the treatment panels was evaluated from the predicted and measured data. Although experimental difficulties were encountered at the design condition, sufficient information was obtained to confirm the expectation that it is the panel impedance components which are critical to suppression at a single frequency, not the particular construction materials. The agreement obtained between measurement and prediction indicates that the analytical program can be used as an accurate, reliable, and useful design tool