Crop and weed response to reduced fertilization and tillage system in rainfed cereal crops

Se muestran diversos resultados obtenidos durante 2013 y 2014, en un monocultivo de trigo (E1, 32 años) y una rotación de trigo- guisante proteaginoso (E3, 13 años), con dos niveles de fertilización: tradicional y reducida un 50%, bajo laboreo convencional (LC), mínimo (LM) y siembra directa (SD). La nascencia de los cultivos no resultó afectada por el laboreo ni la fertilización, salvo en guisante (LC, 2013). Los rendimientos de trigo fueron siempre mayores en SD, y bajo fertilización reducida en 2014 (E3). Entre las arvenses principales, Chenopodium album, Amaranthus blitoides y Polygonum aviculare, fueron más abundantes en LC o LM. Descurainia sophia y Papaver rhoeas lo fueron en SD y Anacyclus clavatus en LM. La mayor densidad de arvenses se registró en SD y tan solo Lactuca serriola resultó afectada por el nivel de fertilización.This work shows different results obtained in 2013 and 2014 growing seasons in a wheat monoculture field experiment (E1) lasting 32 years, and in a wheat-pea rotation field experiment (E2) lasting 13 years. Two levels of nitrogen fertilization. were considered, traditional and reduced (rates were reduced by 50%), in three different tillage systems: conventional tillage (LC), minimum tillage (LM) and no-tillage (SD). Seedling emergence was not affected by tillage and fertilizer rates except in the pea crop in LC in 2013. Wheat yields peaked in 2014 in SD with reduced fertilization. Considering the weed flora, main species such as Chenopodium album, Amaranthus blitoides and Polygonum aviculare were more abundant in LC and LM. However, Papaver rhoeas and Descurainia sophia were more abundant in SD, and Anacyclus clavatus in LM. The highest weed density was observed in SD and just Lactuca serriola was the only weed species affected by the level of fertilization

Effect of tillage system on the functional diversity of weed communities: Is it worth measuring local functional traits?

Este trabajo tiene un doble objetivo: i) testar el efecto de tres sistemas de laboreo (laboreo de subsuelo, laboreo mínimo y siembra directa) sobre la diversidad funcional de la comunidad de arvenses; ii) evaluar la necesidad de hacer mediciones locales de rasgos funcionales (área foliar específica (SLA), altura total de la planta y peso de las semillas) para analizar el efecto del tipo de manejo. Se han calculado tres índices de diversidad funcional con los valores de los rasgos obtenidos en la literatura y con los valores de la comunidad local. El efecto del tipo de laboreo sobre estos índices se ha analizado mediante modelos lineales. Los resultados muestran una influencia del origen de los datos a la hora de detectar el efecto del manejo sobre la diversidad funcional de las comunidades arvenses, siendo la siembra directa el sistema que presenta los índices de diversidad funcional más altos.In this work we aim: i) to test the effect of three tillage systems (subsoil tillage, minimum tillage and no-tillage) on the functional diversity of weed communities; and ii) to assess the need for local measurements of functional traits (specific leaf area (SLA), total height of the plant and seed weight) when assessing the effect of management on weed functional diversity. Three functional diversity indexes have been developed, based on local data and data from the literature. The effect of tillage system on the indexes has been analyzed with linear models. The results show that the origin of the data determines the effect of the soil management on the functional diversity of the weed communities, being no-tillage the system with highest functional diversity indexes

Novel one-pot sol-gel synthesis route of Fe_3C/few-layered graphene core/shell nanoparticles embedded in a carbon matrix

Fe_3C/few-layered graphene core/shell nanoparticles embedded in a carbon matrix are synthesized by a novel two-step surfactant sol-gel strategy, where the processes of hydrolysis, polycondensation and drying take place in a one-pot. The present approach is based on the combined action of oleic acid and oleylamine, which act sterically on the precursor micelles when a densification temperature is performed in a reducing atmosphere. The structural and magnetic evolution of the formed compounds is investigated, ranging from iron oxides such as Fe_3O_4 and FeO, to the formation of pure Fe_3C/C samples from 700 degrees C onwards. Interestingly, Fe_3C nanoparticles with a size of similar to 20 nm crystallize immersed in the carbon matrix and the surrounding environment forms an oriented encapsulation built by few-layered graphene. The nanostructures show a saturation magnetization of similar to 43 emu/g and a moderate coercivity of similar to 500 Oe. Thereby, an innovative chemical route to produce single phase Fe_3C nanoparticles is described, and an effective method of few-layered graphene passivation is proposed, yielding a product with a high magnetic response and high chemical stability against environmental corrosion

Demostraciones prácticas para la promoción de las titulaciones de Grado en Química y Grado en Ingeniería Química

Memoria ID12-0251. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2012-2013

Risk Factors and Predictive Score for Bacteremic Biliary Tract Infections Due to Enterococcus faecalis and Enterococcus faecium: a Multicenter Cohort Study from the PROBAC Project

Biliary-tract bloodstream infections (BT-BSI) caused by Enterococcus faecalis and E. faecium are associated with inappropriate empirical treatment and worse outcomes compared to other etiologies. The objective of this study was to investigate the risk factors for enterococcal BT-BSI. Patients with BT-BSI from the PROBAC cohort, including consecutive patients with BSI in 26 Spanish hospitals between October 2016 and March 2017, were selected; episodes caused by E. faecalis or E. faecium and other causes were compared. Independent predictors for enterococci were identified by logistic regression, and a predictive score was developed. Eight hundred fifty episodes of BT-BSI were included; 73 (8.5%) were due to target Enterococcus spp. (48 [66%] were E. faecium and 25 [34%] E. faecalis). By multivariate analysis, the variables independently associated with Enterococcus spp. were (OR; 95% confidence interval): cholangiocarcinoma (4.48;1.32 to 15.25), hospital acquisition (3.58;2.11 to 6.07), use of carbapenems in the previous month (3.35;1.45 to 7.78), biliary prosthesis (2.19;1.24 to 3.90), and moderate or severe chronic kidney disease (1.55;1.07 to 2.26). The AUC of the model was 0.74 [95% CI0.67 to 0.80]. A score was developed, with 7, 6, 5, 4, and 2 points for these variables, respectively, with a negative predictive value of 95% for a score # 6. A model, including cholangiocarcinoma, biliary prosthesis, hospital acquisition, previous carbapenems, and chronic kidney disease showed moderate prediction ability for enterococcal BT-BSI. Although the score will need to be validated, this information may be useful for deciding empirical therapy in biliary tract infections when bacteremia is suspected. IMPORTANCE Biliary tract infections are frequent, and a significant cause of morbidity and mortality. Bacteremia is common in these infections, particularly in the elderly and patients with cancer. Inappropriate empirical treatment has been associated with increased risk of mortality in bacteremic cholangitis, and the probability of receiving inactive empirical treatment is higher in episodes caused by enterococci. This is because many of the antimicrobial agents recommended in guidelines for biliary tract infections lack activity against these organisms. To the best of our knowledge, this is the first study analyzing the predictive factors for enterococcal BT-BSI and deriving a predictive score.8 página

Revisiting the epidemiology of bloodstream infections and healthcare-associated episodes: results from a multicentre prospective cohort in Spain (PRO-BAC Study)

PROBAC REIPI/GEIH-SEIMC/SAEI Group.The epidemiology of bloodstream infections (BSIs) is dynamic as it depends on microbiological, host and healthcare system factors. The aim of this study was to update the information regarding the epidemiology of BSIs in Spain considering the type of acquisition. An observational, prospective cohort study in 26 Spanish hospitals from October 2016 through March 2017 including all episodes of BSI in adults was performed. Bivariate analyses stratified by type of acquisition were performed. Multivariate analyses were performed by logistic regression. Overall, 6345 BSI episodes were included; 2510 (39.8%) were community-acquired (CA), 1661 (26.3%) were healthcare-associated (HCA) and 2056 (32.6%) hospital-acquired (HA). The 30-day mortality rates were 11.6%, 19.5% and 22.0%, respectively. The median age of patients was 71 years (interquartile range 60–81 years) and 3656 (58.3%; 95% confidence interval 57.1–59.6%) occurred in males. The proportions according to patient sex varied according to age strata. Escherichia coli (43.8%), Klebsiella spp. (8.9%), Staphylococcus aureus (8.9%) and coagulase-negative staphylococci (7.4%) were the most frequent pathogens. Multivariate analyses confirmed important differences between CA and HCA episodes, but also between HCA and HA episodes, in demographics, underlying conditions and aetiology. In conclusion, we have updated the epidemiological information regarding patients’ profiles, underlying conditions, frequency of acquisition types and aetiological agents of BSI in Spain. HCA is confirmed as a distinct type of acquisition.This work was financed by grants from Plan Nacional de I+D+i 2013–2016, Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades [PI16/01432] and the Spanish Network for Research in Infectious Diseases (REIPI) [RD16/0016/0001; RD16/0016/0008], co‐financed by the European Development Regional Fund ‘A way to achieve Europe’, Operative program Intelligent Growth 2014–2020

Risk Factors and Predictive Score for Bacteremic Biliary Tract Infections Due to Enterococcus faecalis and Enterococcus faecium: a Multicenter Cohort Study from the PROBAC Project

Biliary-tract bloodstream infections (BT-BSI) caused by Enterococcus faecalis and E. faecium are associated with inappropriate empirical treatment and worse outcomes compared to other etiologies. The objective of this study was to investigate the risk factors for enterococcal BT-BSI. Patients with BT-BSI from the PROBAC cohort, including consecutive patients with BSI in 26 Spanish hospitals between October 2016 and March 2017, were selected; episodes caused by E. faecalis or E. faecium and other causes were compared. Independent predictors for enterococci were identified by logistic regression, and a predictive score was developed. Eight hundred fifty episodes of BT-BSI were included; 73 (8.5%) were due to target Enterococcus spp. (48 [66%] were E. faecium and 25 [34%] E. faecalis). By multivariate analysis, the variables independently associated with Enterococcus spp. were (OR; 95% confidence interval): cholangiocarcinoma (4.48;1.32 to 15.25), hospital acquisition (3.58;2.11 to 6.07), use of carbapenems in the previous month (3.35;1.45 to 7.78), biliary prosthesis (2.19;1.24 to 3.90), and moderate or severe chronic kidney disease (1.55;1.07 to 2.26). The AUC of the model was 0.74 [95% CI0.67 to 0.80]. A score was developed, with 7, 6, 5, 4, and 2 points for these variables, respectively, with a negative predictive value of 95% for a score ? 6. A model, including cholangiocarcinoma, biliary prosthesis, hospital acquisition, previous carbapenems, and chronic kidney disease showed moderate prediction ability for enterococcal BT-BSI. Although the score will need to be validated, this information may be useful for deciding empirical therapy in biliary tract infections when bacteremia is suspected. IMPORTANCE Biliary tract infections are frequent, and a significant cause of morbidity and mortality. Bacteremia is common in these infections, particularly in the elderly and patients with cancer. Inappropriate empirical treatment has been associated with increased risk of mortality in bacteremic cholangitis, and the probability of receiving inactive empirical treatment is higher in episodes caused by enterococci. This is because many of the antimicrobial agents recommended in guidelines for biliary tract infections lack activity against these organisms. To the best of our knowledge, this is the first study analyzing the predictive factors for enterococcal BT-BSI and deriving a predictive score

Colaboración universidad/empresa para la promoción de las titulaciones de grado en química y grado en ingeniería química

Memoria ID-0018. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2013-2014

Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions

Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics