6,301 research outputs found
Development of cisgenic apples with durable resistance to apple scab
Most of the apple (Malus × domestica) growers are facing serious disease problems with apple scab which is caused by the fungus Venturia inaequalis. Developing a resistant variety in apple through classical breeding is very slow and inefficient. So, we aim at improving existing apple varieties through a new concept called “cisgenesis” which saves time and effort compared to classical breeding. Malus floribunda proved to be a good source of natural scab resistance genes. The genes HcrVf1 and HcrVf2, consisting of promoter, coding and terminator sequences in their natural configuration, were isolated from Malus floribunda and cloned into the binary vector pMF1. Apple cv. ‘Gala’ was transformed with pMF1 containing HcrVf1 and HcrVf2, individually or in combination. pMF1 can be used to obtain marker-free plants by recombinase-based excision of a fragment carrying undesired gene sequences, such as antibiotic-selection marker genes, leaving behind only the gene(s)-of-interest and one recombination site. Using this vector it is therefore possible to stack several genes by retransformation using the same selection procedure. In order to obtain durable resistance, we have the intention to combine different resistance genes from Malus either by stacking them one by one or by introducing them all together in one T-DNA. Performance of all different types of cisgenic plants will be evaluated by monitoring scab resistance levels phenotypically and by determining gene expression profiles through quantitative RT-PC
Consideraciones acerca de una historia de la filosofía argentina
Fil: Soriano, E.
Construction of a high anchored wall at highway EX-A1 (Spain)
Descripción de la problemática encontrada en un desmonte de la autovía EX-A1 (Navalmoral de la Mata-Frontera portuguesa). Descripción de la solución adoptada: muro anclado.
Highway EX-A1, near the Spain-Portugal border, crosses a Tertiary formation of weak marly rocks that are affected by high
tectonic stresses that had created a good number of failure planes within the rock. During the past geologic times, some large landslides had
taken place. They are now covered by Quaternary soils. The design of high cuts in this type of rock formation is somewhat troublesome.
The paper indicates one of the solutions that have been implemented to stabilize one of the main highway cuts.
L’autoroute EX-A1, près de la frontière entre l’Espagne et le Portugal, traverse une formation tertiaire de roches marneuses
faibles avec des contraintes tectoniques élevées qui ont provoqué de nombreuses surfaces de rupture dans la roche. Au cours des temps
géologiques passés, des grands glissements ont eu lieu et ils se retrouvent maintenant couverts par des sols quaternaires. Le projet
d’excavations de grande hauteur dans cette formation rocheuse est généralement problématique. L’article décrit la solution qui a été mise
en oeuvre pour stabiliser un des principaux déblais de l’autoroute
Tobacco use in the third trimester of pregnancy and its relationship to birth weight. A prospective study in Spain
Background Few studies have been carried out in Spain examining the use of tobacco amongst expectant mothers and its effect on birth weight. Aims To observe the proportion of expectant mothers who smoke during their pregnancy, and the impact of tobacco consumption on maternal and birth weight. We also aimed to identify the trimester of pregnancy in which tobacco use produced the greatest reduction in birth weight. Methods Prospective observational study in Spain. A random sampling strategy was used to select health centres and participant women. A total of 137 individuals were enrolled in the study. Exposure to tobacco was measured through a self-reported questionnaire. Regressions were performed to obtain a predictive model for birth weight related to smoking. Findings Overall, 35% of study participants were smokers during the pre-gestational period (27% in the first trimester, 21.9% in the second and 21.2% in the third). 38.7% of smoking cessation attempts took place in the third-trimester. Pregnant women who smoked up to the third trimester had a higher risk of giving birth to a baby under 3000 g, compared to non-smokers (OR = 5.94, CI 95%: 1.94–18.16). Each additional unit of tobacco consumed daily in the 3rd trimester led to a 32 g reduction in birth weight. Conclusion An important proportion of pregnant women in Spain smoke during pregnancy. Pregnant women exposed to tobacco have newborns with lower birth weight. Smoking during the 3rd trimester of pregnancy is associated with the greatest risk of lower birth weight
Localized basis sets for unbound electrons in nanoelectronics
It is shown how unbound electron wave functions can be expanded in a suitably
chosen localized basis sets for any desired range of energies. In particular,
we focus on the use of gaussian basis sets, commonly used in first-principles
codes. The possible usefulness of these basis sets in a first-principles
description of field emission or scanning tunneling microscopy at large bias is
illustrated by studying a simpler related phenomenon: The lifetime of an
electron in a H atom subjected to a strong electric field.Comment: 6 pages, 5 figures, accepted by J. Chem. Phys. (http://jcp.aip.org/
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