Spinor algebra and null solutions of the wave equation

In this paper we exploit the ideas and formalisms of twistor theory, to show how, on Minkowski space, given a null solution of the wave equation, there are precisely two null directions in $\ker df$, at least one of which is a shear-free ray congruence

Developpement des techniques d'analyse par faisceaux d'ions acceleres elementaires (PIXE PIGE) et structurales (HSF-SIMS): - applications a l'analyse des sols sans traitement prealable

BIASPas de résum

Una metodología para la evaluación de la sustentabilidad de sistemas productivos primarios

Sustentabilidad y resiliencia son consideradas básicas para alcanzar un funcionamiento balanceado de los sistemas socio-ecológicos frente a condiciones internas cambiantes y shocks externos. Sin embargo, no existe consenso en cuanto a la medición de ambos conceptos como contribución al manejo de los sistemas productivos locales en esa dirección. Consecuente con estas ideas, en este trabajo se presenta una metodología para evaluar la Sustentabilidad de Sistema Productivos Agropecuarios, como resultado de dos años de investigación interdisciplinaria La posibilidad de aplicar esta metodología descansa en un proceso colaborativo entre ciencia y política para mejorar la resiliencia y por lo tanto la sustentabilidad de los sistemas productivos locales.Sustainability and resilience are considered the base for reaching a balanced functioning of socio-ecological systems, facing internal conditions and external shocks. However, there is no agreement on how to get a good measure of both concepts to allow for managing local production systems in that sense. In this paper is presented a methodology for assessing Sustainability of Agriculture Production Systemsas result of a two-year research. The possibility for applying this methodology rests on a collaborative process between science and policy to improve resilience, and therefore sustainability of local production systems.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Una metodología para la evaluación de la sustentabilidad de sistemas productivos primarios

Sustentabilidad y resiliencia son consideradas básicas para alcanzar un funcionamiento balanceado de los sistemas socio-ecológicos frente a condiciones internas cambiantes y shocks externos. Sin embargo, no existe consenso en cuanto a la medición de ambos conceptos como contribución al manejo de los sistemas productivos locales en esa dirección. Consecuente con estas ideas, en este trabajo se presenta una metodología para evaluar la Sustentabilidad de Sistema Productivos Agropecuarios, como resultado de dos años de investigación interdisciplinaria La posibilidad de aplicar esta metodología descansa en un proceso colaborativo entre ciencia y política para mejorar la resiliencia y por lo tanto la sustentabilidad de los sistemas productivos locales.Sustainability and resilience are considered the base for reaching a balanced functioning of socio-ecological systems, facing internal conditions and external shocks. However, there is no agreement on how to get a good measure of both concepts to allow for managing local production systems in that sense. In this paper is presented a methodology for assessing Sustainability of Agriculture Production Systemsas result of a two-year research. The possibility for applying this methodology rests on a collaborative process between science and policy to improve resilience, and therefore sustainability of local production systems.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

A variant in XPNPEP2 is associated with angioedema induced by angiotensin I-converting enzyme inhibitors

Angiotensin I-converting enzyme inhibitors (ACEi), which are used to treat common cardiovascular diseases, are associated with a potentially life-threatening adverse reaction known as angioedema (AE-ACEi). We have previously documented a significant association between AE-ACEi and low plasma aminopeptidase P (APP) activity. With eight large pedigrees, we hereby demonstrate that this quantitative trait is partially regulated by genetic factors. We tested APP activity using a variance-component QTL analysis of a 10-cM genomewide microsatellite scan enriched with seven markers over two candidate regions. We found significant linkage (LOD = 3.75) to a locus that includes the YPNPEP2 candidate gene encoding membrane-bound APP. Mutation screening of this QTL identified a large coding deletion segregating in one pedigree and an upstream single-nucleotide polymorphism (C2399A SNP), which segregates in the remaining seven pedigrees. Measured genotype analysis strongly suggests that the linkage signal for APP activity at this locus is accounted for predominantly by the SNP association. In a separate case-control study (20 cases and 60 controls), we found significant association of this SNP to ACEi-induced AE (P =.0364). In conclusion, our findings provide supporting evidence that the C-2399A variant in YPNPEP2 is associated with reduced APP activity and a higher incidence of AE-ACEi

Changes in adductor strength after competition in Academy Rugby Union Players

© 2016 National Strength and Conditioning Association. This study determined the magnitude of change in adductor strength after a competitive match in academy rugby union players and examined the relationship between locomotive demands of match-play and changes in postmatch adductor strength. A withinsubject repeated measures design was used. Fourteen academy rugby union players (age, 17.4 ± 0.8 years; height, 182.7 ± 7.6 cm; body mass, 86.2 ± 11.6 kg) participated in the study. Each player performed 3 maximal adductor squeezes at 458 of hip flexion before and immediately, 24, 48, and 72 hours postmatch. Global positioning system was used to assess locomotive demands of match-play. Trivial decreases in adductor squeeze scores occurred immediately (21.3 ± 2.5%; effect size [ES] = 20.11 ± 0.21; likely, 74%) and 24 hours after match (20.7 ± 3%; ES = 20.06 ± 0.25; likely, 78%), whereas a small but substantial increase occurred at 48 hours (3.8 ± 1.9%; ES = 0.32 ± 0.16; likely, 89%) before reducing to trivial at 72 hours after match (3.1 ± 2.2%; ES = 0.26 ± 0.18; possibly, 72%). Large individual variation in adductor strength was observed at all time points. The relationship between changes in adductor strength and distance covered at sprinting speed (VO2max 81%) was large immediately postmatch (p = 0.056, r = 20.521), moderate at 24 hours (p = 0.094, r = 20.465), and very large at 48 hours postmatch (p = 0.005, r = 20.707). Players who cover greater distances sprinting may suffer greater adductor fatigue in the first 48 hours after competition. The assessment of adductor strength using the adductor squeeze test should be considered postmatch to identify players who may require additional rest before returning to field-based training