Strain-age cracking in Rene 41 alloy

Weldability test determines the effects of material and process variables on the occurrence of strain-age cracking, and demonstrates effective and practical means for its reduction. Studies consist of tensile, impact, and stress-rupture tests

Distribución espacial de la vulnerabilidad futura bajo escenario de cambio climático. Serie 3. Análisis municipal para Corredor Seco hondureño.

Mediante la prospectiva estratégica y la ciencia de los datos, se puede dibujar diferentes trayectorias del impacto futuro al sistema agrícola hondureño en respuesta al cambio climático. Los escenarios proyectan tendencias negativas en los cultivos básicos en la demanda de los hogares y cultivos con gran valor comercial. El cambio climático afectaría la aptitud de los territorios para la siembra de cultivos de alta importancia en la dieta local. Esto podría influir en la distribución del suelo y el ordenamiento del espacio rural. La vulnerabilidad en el Corredor Seco en el futuro presentaría patrones claros de aglomeración. Entendiendo que estos fenómenos indeseables pueden ser persistentes en el tiempo, se demandaría una política integral que armonice las acciones locales y nacionales, coordinando el actuar de múltiples instituciones publico privadas en la región del Corredor Seco.Through the strategic prospect and data science, different trajectories of the future impact on the Honduran agricultural system can be drawn in response to climate change. The scenarios project negative trends in basic crops in the demand of households and crops with great commercial value. Climate change would affect the territories' ability to plant crops of high importance in the local diet. This could influence the distribution of land and the arrangement of rural space. Vulnerability in the Dry Corridor in the future would present clear agglomeration patterns. Understanding that these undesirable climatic events can be persistent over time, a comprehensive policy that harmonizes local and national actions would be demanded, coordinating the actions of multiple public-private institutions in the Dry Corridor regio

De los escenarios a las trayectorias de desarrollo para la seguridad alimentaria bajo cambio climático en Honduras. Serie 1. Impacto Nacional

Los escenarios futuros son una excelente oportunidad de capturar las principales preocupaciones de los múltiples actores de una región. Al igual que contribuir con las discusiones orientadas a la priorización y planeación de sus intervenciones. Los escenarios futuros dibujan una potencial vulnerabilidad del sistema nacional de alimentos bajo dos estrategias de estímulo al sector agrícola, comercial y asociado a seguridad alimentaria. Toda vez que las condiciones climáticas futuras exacerbarían las productividades, el uso del suelo y el posicionamiento en el comercio mundial. Dada las características de la dieta, la geografía económica y los procesos de urbanización, los escenarios en su capacidad de simplificación dejan entrever la necesidad de estimular y desarrollar las capacidades de adaptación local. Para ello, el rol de las instituciones y en general de todos los involucrados en ejercicios de prospectiva estratégica, reduce la incertidumbre futura y mejora la priorización de las acciones colectivas.Future scenarios are an excellent opportunity to capture the main concerns of the multiple actors in a region. As well as contributing to the discussions aimed at prioritizing and planning their interventions. Future scenarios draw a potential vulnerability of the national food system under two strategies to stimulate the agricultural, commercial and food security sector. Since future weather conditions would exacerbate productivity, land use and position in world trade. Given the characteristics of the diet, economic geography and urbanization processes, the scenarios in their capacity for simplification suggest the need to stimulate and develop local adaptation capacities. For this, the role of institutions and in general of all those involved in strategic prospective exercises reduces future uncertainty and improves the prioritization of collective actions

Prevalence of qacA/B genes and mupirocin resistance among methicillin-resistant Staphylococcus aureus (MRSA) isolates in the setting of chlorhexidine bathing without mupirocin

OBJECTIVE: We aimed to determine the frequency of qacA/B chlorhexidine tolerance genes and high-level mupirocin resistance among MRSA isolates before and after the introduction of a chlorhexidine (CHG) daily bathing intervention in a surgical intensive care unit (SICU). DESIGN: Retrospective cohort study (2005–2012) SETTING: A large tertiary-care center PATIENTS: Patients admitted to SICU who had MRSA surveillance cultures of the anterior nares METHODS: A random sample of banked MRSA anterior nares isolates recovered during (2005) and after (2006–2012) implementation of a daily CHG bathing protocol was examined for qacA/B genes and high-level mupirocin resistance. Staphylococcal cassette chromosome mec (SCCmec) typing was also performed. RESULTS: Of the 504 randomly selected isolates (63 per year), 36 (7.1%) were qacA/B positive ( + ) and 35 (6.9%) were mupirocin resistant. Of these, 184 (36.5%) isolates were SCCmec type IV. There was a significant trend for increasing qacA/B (P= .02; highest prevalence, 16.9% in 2009 and 2010) and SCCmec type IV (P< .001; highest prevalence, 52.4% in 2012) during the study period. qacA/B( + ) MRSA isolates were more likely to be mupirocin resistant (9 of 36 [25%] qacA/B( + ) vs 26 of 468 [5.6%] qacA/B(−); P= .003). CONCLUSIONS: A long-term, daily CHG bathing protocol was associated with a change in the frequency of qacA/B genes in MRSA isolates recovered from the anterior nares over an 8-year period. This change in the frequency of qacA/B genes is most likely due to patients in those years being exposed in prior admissions. Future studies need to further evaluate the implications of universal CHG daily bathing on MRSA qacA/B genes among hospitalized patients

Improved timed-mating, non-invasive method using fewer unproven female rats with pregnancy validation via early body mass increases

For studies requiring accurate conception-timing, reliable, efficient methods of detecting oestrus reduce time and costs, whilst improving welfare. Standard methods use vaginal cytology to stage cycle, and breeders are paired–up using approximately five proven females with proven males to achieve at least one conception on a specific day. We describe an alternative, fast, consistent, non-invasive method of timed-mating using detection of lordosis behaviour in Wistar and Lister-Hooded rats that used unproven females with high success rates. Rats under reverse-lighting had body masses recorded pre-mating, day (d) 3-4, d8, d10 and d18 of pregnancy. Using only the presence of the oestrus dance to time-mate females for 24-hrs, 89% Wistar and 88% Lister-Hooded rats successfully conceived. We did not observe behavioural oestrus in Sprague-Dawleys without males present. Significant body mass increases following mating distinguished pregnant from non-pregnant rats, as early as d4 of pregnancy (10% ± 1.0 increase cf 3% ± 1.2). The pattern of increases throughout gestation was similar for all pregnant rats until late pregnancy, when there were smaller increases for primi- and multiparous rats (32% ± 2.5; 25% ± 2.4), whereas nulliparous rats had highest gains (38% ± 1.5). This method demonstrated a distinct refinement of the previous timed-mating common practice used, as disturbance of females was minimised. Only the number required of nulli-, primi- or multiparous rats were mated, and body mass increases validated pregnancy status. This new breeding-management method is now established practice for two strains of rat and resulted in a reduction in animal use

Band Formation during Gaseous Diffusion in Aerogels

We study experimentally how gaseous HCl and NH_3 diffuse from opposite sides of and react in silica aerogel rods with porosity of 92 % and average pore size of about 50 nm. The reaction leads to solid NH_4Cl, which is deposited in thin sheet-like structures. We present a numerical study of the phenomenon. Due to the difference in boundary conditions between this system and those usually studied, we find the sheet-like structures in the aerogel to differ significantly from older studies. The influence of random nucleation centers and inhomogeneities in the aerogel is studied numerically.Comment: 7 pages RevTex and 8 figures. Figs. 4-8 in Postscript, Figs. 1-3 on request from author

Interfacial layering in a three-component polymer system

We study theoretically the temporal evolution and the spatial structure of the interface between two polymer melts involving three different species (A, A* and B). The first melt is composed of two different polymer species A and A* which are fairly indifferent to one another (Flory parameter chi_AA* ~ 0). The second melt is made of a pure polymer B which is strongly attracted to species A (chi_AB 0). We then show that, due to these contradictory tendencies, interesting properties arise during the evolution of the interface after the melts are put into contact: as diffusion proceeds, the interface structures into several adjacent "compartments", or layers, of differing chemical compositions, and in addition, the central mixing layer grows in a very asymmetric fashion. Such unusual behaviour might lead to interesting mechanical properties, and demonstrates on a specific case the potential richness of multi-component polymer interfaces (as compared to conventional two-component interfaces) for various applications.Comment: Revised version, to appear in Macromolecule