Seleccion de progenitores y planificacion de cruzamientos

Criteria to select parents within a breeding program involving local or introduced var. are given. Every yr. the CIAT Bean Program publishes the results of international trials, highlighting the importance of desirable crop characteristics for each national program. Parental selection can be directed toward the improvement of var. or of one character, e.g., disease resistance. Since in some cases complete resistance is not obtained, tolerant parents can be combined to produce cumulative tolerance. The environment is also important, inducing variations in photoperiod, precipitation, temp., and even in disease pathogenicity (strains); this affects complex polygenetically-controlled characters, such as yield. (CIAT)Se exponen algunos criterios para seleccionar progenitores dentro de un programa de fitomejoramiento, a partir de var. locales o introducidas. Anualmente, el Programa de Frijol de CIAT publica los resultados de los ensayos internacionales y senala la importancia de las caracteristicas deseables del cultivo para cada programa nacional. La seleccion de los progenitores puede orientarse hacia el mejoramiento de var. o de un caracter, como resistencia a enfermedades. Como en algunos casos no se obtiene resistencia total, se pueden combinar progenitores tolerantes para producir tolerancia acumulativa. Otro factor importante es el ambiente, que induce variaciones en fotoperiodo, precipitacion, temp. y hasta en la patogenicidad (razas) de las enfermedades, afectando los caracteres complejos controlados poligenicamente, como el rendimiento. (CIAT

La produccion de semilla genetica de frijol

The different precautions that should be taken when producing good quality seed are indicated as well as the procedure to maintain intravarietal homogeneity. Seed quality components are (1) purity, that is, no seeds of other var. are included; (2) vigor, which determines germination power and rate; and (3) health (free of pathogens). Maintaining a var. implies planting lots where a new selection is made of those individual plants that maintain visually recognizable characteristics considered typical of the var., such as color of the stem, hypocotyl, and flower; pod color and shape; and plant architecture, among others. The breeder or breeding program is responsible for the production of good quality seed; this process must be continuous in order to produce improved seed at least every 3 or 4 yr. (CIAT)Se indican las diferentes precauciones que deben tomarse al producir semilla de buena calidad y el procedimiento para mantener la homogeneidad dentro de una var. Los componentes de la calidad de la semilla son 1) pureza, es decir, que no incluya semilla de otras var.; 2) vigor, que determina la capacidad y la velocidad de germinacion y 3) sanidad, es decir, que este libre de patogenos. El mantenimiento de una var. implica la siembra de lotes donde se reseleccionan plantas individualmente que conservan las caracteristicas propias de la var., de facil reconocimiento visual, como son color del tallo, del hipocotilo y de la flor; color y forma de la vaina y arquitectura de la planta, entre otros. La produccion de semilla de buena calidad es responsabilidad del fitomejorador o del programa de mejoramiento; este proceso debe hacerse de manera continua para producir semilla mejorada cada 3 o 4 anos como min. (CIAT

Chromogenic guest-responsive host compounds which allow rapid guest screening

Azo host compounds undergo rapid and clearly visible colour changes from yellow to bright orange/red on complexation with guest molecules, while no colour change is noted in the absence of complexation. This provides a rapid screening method for potential guest compounds as the first step towards the development of guest specific host compounds for use in sensors relying only on a simple, visible colour change readout mechanism

Arterial Remodeling and Endothelial Shear Stress Exhibit Significant Longitudinal Heterogeneity Along the Length of Coronary Plaques

Atherosclerosis is determined by both systemic risk factors and local vascular mechanisms. The arterial remodeling in response to plaque development plays a key role in atherosclerosis. Compensatory expansive remodeling is an adaptive mechanism that maintains lumen patency as a plaque develops. In contrast, excessive expansive remodeling, signifying an enlargement in vascular and lumen volume as a result of local plaque buildup, is a consistent attribute of high-risk plaques. Local hemodynamic factors, in particular low endothelial shear stress (ESS), is an intensely proinflammatory and proatherogenic stimulus and largely accounts for the spatially diverse distribution of atherosclerotic plaques. However, plaque, remodeling and ESS have hitherto been investigated only in the cross-sectional arterial axis and their distribution in the longitudinal axis of individual plaques has not been characterized

Mobile Air Quality Studies (MAQS) - an international project

Due to an increasing awareness of the potential hazardousness of air pollutants, new laws, rules and guidelines have recently been implemented globally. In this respect, numerous studies have addressed traffic-related exposure to particulate matter using stationary technology so far. By contrast, only few studies used the advanced technology of mobile exposure analysis. The Mobile Air Quality Study (MAQS) addresses the issue of air pollutant exposure by combining advanced high-granularity spatial-temporal analysis with vehicle-mounted, person-mounted and roadside sensors. The MAQS-platform will be used by international collaborators in order 1) to assess air pollutant exposure in relation to road structure, 2) to assess air pollutant exposure in relation to traffic density, 3) to assess air pollutant exposure in relation to weather conditions, 4) to compare exposure within vehicles between front and back seat (children) positions, and 5) to evaluate "traffic zone"- exposure in relation to non-"traffic zone"-exposure. Primarily, the MAQS-platform will focus on particulate matter. With the establishment of advanced mobile analysis tools, it is planed to extend the analysis to other pollutants including including NO2, SO2, nanoparticles, and ozone

RNA extraction from self-assembling peptide hydrogels to allow qPCR analysis of encapsulated cells

Self-assembling peptide hydrogels offer a novel 3-dimensional platform for many applications in cell culture and tissue engineering but are not compatible with current methods of RNA isolation; owing to interactions between RNA and the biomaterial. This study investigates the use of two techniques based on two different basic extraction principles: solution-based extraction and direct solid-state binding of RNA respectively, to extract RNA from cells encapsulated in four β-sheet forming self-assembling peptide hydrogels with varying net positive charge. RNA-peptide fibril interactions, rather than RNA-peptide molecular complexing, were found to interfere with the extraction process resulting in low yields. A column-based approach relying on RNA-specific binding was shown to be more suited to extracting RNA with higher purity from these peptide hydrogels owing to its reliance on strong specific RNA binding interactions which compete directly with RNA-peptide fibril interactions. In order to reduce the amount of fibrils present and improve RNA yields a broad spectrum enzyme solution—pronase—was used to partially digest the hydrogels before RNA extraction. This pre-treatment was shown to significantly increase the yield of RNA extracted, allowing downstream RT-qPCR to be performed

Clinical Characteristics of Subependymal Giant Cell Astrocytoma in Tuberous Sclerosis Complex.

Background: This study evaluated the characteristics of subependymal giant cell astrocytoma (SEGA) in patients with tuberous sclerosis complex (TSC) entered into the TuberOus SClerosis registry to increase disease Awareness (TOSCA). Methods: The study was conducted at 170 sites across 31 countries. Data from patients of any age with a documented clinical visit for TSC in the 12 months preceding enrollment or those newly diagnosed with TSC were entered. Results: SEGA were reported in 554 of 2,216 patients (25%). Median age at diagnosis of SEGA was 8 years (range, 18 years. SEGA were symptomatic in 42.1% of patients. Symptoms included increased seizure frequency (15.8%), behavioural disturbance (11.9%), and regression/loss of cognitive skills (9.9%), in addition to those typically associated with increased intracranial pressure. SEGA were significantly more frequent in patients with TSC2 compared to TSC1 variants (33.7 vs. 13.2 %, p < 0.0001). Main treatment modalities included surgery (59.6%) and mammalian target of rapamycin (mTOR) inhibitors (49%). Conclusions: Although SEGA diagnosis and growth typically occurs during childhood, SEGA can occur and grow in both infants and adults

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

Mean-field and stability analysis of two-dimensional flowing soft-core bosons modeling a supersolid

The soft-core boson system is one of the simplest models of supersolids, which have both off-diagonal long-range order (Bose-Einstein condensation) and diagonal long-range order (crystalline order). Although this model has been studied from various points of view, studies of the stability of current-flowing states are lacking. Solving the Gross-Pitaevskii and Bogoliubov equations, we obtain excitation spectra in superfluid, supersolid, and stripe phases. On the basis of the results of the excitation spectra, we present a stability phase diagram that shows the region of the metastable superflow states for each phase.Comment: 7 pages, 5 figure