Protein folding and the robustness of cells

The intricate intracellular infrastructure of all known life forms is based on proteins. The folded shape of a protein determines both the protein’s function and the set of molecules it will bind to. This tight coupling between a protein’s function and its interconnections in the molecular interaction network has consequences for the molecular course of evolution. It is also counter to human engineering approaches. Here we report on a simulation study investigating the impact of random errors in an abstract metabolic network of 500 enzymes. Tight coupling between function and interconnectivity of nodes is compared to the case where these two properties are independent. Our results show that the model system under consideration is more robust if function and interconnection are intertwined. These findings are discussed in the context of nanosystems engineering

Factores ambientales condicionantes de la presencia de la lagartija de Carbonell Podarcis carbonelli (Pérez-Mellado, 1981) en la comarca de Doñana

The Carbonell lizard (Podarcis carbonelli) is an Iberian endemism. The region of Doñana is its southernmost and more isolated stronghold. We used logistic regressions to investigate the factors conditioning the presence of this lizard in Doñana. All selected models retained the distance to the coast as the main variable. This variable is related with less humidity and more continental climatic conditions, including more extreme temperatures, when further from the coast. This climatic factor was observed both spatially and temporarily, with adult lizards drastically reducing their activity both in winter and in summer. We observed juveniles from June to January, with a maximum in September. Scrubland management was another important environmental factor affecting the presence of lizards. The probability of finding this species was higher where the scrubland was partially cleared, and lower in areas with a high plant cover (hygrophytic scrubland) or in areas with sparse vegetation (dune scrubland), probably due to a lower amount of incident light and less protection when moving between refuges, respectively.La lagartija de Carbonell es un endemismo ibérico que encuentra en la comarca de Doñana el reducto más meridional y aislado de su área de distribución. Mediante el uso de regresiones logísticas se ha intentado conocer qué factores condicionan la presencia de la lagartija de Carbonell en Doñana. La variable principal de los distintos modelos fue la distancia a la costa. Ésta se relaciona con un menor grado de humedad y una mayor continentalidad del clima, con temperaturas más extremas, a medida que nos alejamos del mar. Este condicionante climático se ha observado tanto espacial como temporalmente, reduciéndose drásticamente la actividad de los animales adultos en verano e invierno. Los juveniles se observan desde junio a enero con un máximo en septiembre. Otro de los factores importantes ha resultado ser la gestión del matorral. Se ha observado una mayor probabilidad de encontrar la lagartija de Carbonell en zonas en las que el matorral ha sido parcialmente clareado, ya que evita los lugares con elevadas densidades de plantas (matorral hidrofílico), que reducirían el paso de la luz, o con una densidad muy baja (matorral de las dunas), que no permitiría el tránsito seguro entre refugios

El arte en México

Copia digital. España : Ministerio de Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

Evaluación de una técnica de RT-PCR específica para la detección del serotipo 8 del virus de la lengua azul en cabras

El virus de la lengua azul (vLA) es un Orbivirus transmitido por mosquitos hematófagos del género Culicoides. En el norte de España ha aparecido recientemente el serotipo 8, afectando a ovejas y vacas. Los serotipos de vLA son tan distintos entre sí, que las vacunas no ofrecen protección cruzada. Por tanto, es fundamental identificar cual afecta al animal para aplicar la vacuna correcta. En estudios recientes se ha desarrollado un ensayo de RT PCR para detectar el serotipo 8 de vLA en vacas y ovejas. En este estudio hemos evaluado dicha técnica para la detección específica del serotipo 8 en cabras. Se analizaron 15 sueros de cabras infectadas y sobrenadantes de cultivos celulares infectados con el serotipo 8. Las muestras de sueros analizados no dieron resultados positivos.Bluetongue virus (BTV) is an Orbivirus transmitted by haematophagous insects of the genus Culicoides. In the north of the Iberian Peninsula, BTV-8 has appeared recently, affecting sheep and cattle. Bluetongue serotypes are so different among them, that vaccines do not offer cross-protection. Thus, it is important to detect which serotype is affecting an animal, in order to apply the correct vaccine. An RT-PCR assay has been developed recently to detect BTV-8 in cattle and sheep. In this study we have evaluated this RT-PCR technique as a diagnostic tool for the specific detection of BTV- 8 in goats. Sera samples from 15 infected goats and supernatants from BTV-8 infected cell cultures were analyzed. No positive results were obtained for the analyzed samples

Allelopathy for weed control in acid solis with high organic matter

6 páginas.- 5 figuras.[EN] Weeds are one of the major limiting factors in agriculture under temperate humid conditions. Weed control faces a challenge nowadays because developed societies reject synthetic herbicides based on risks for health and environmental conservation. Chemical weed control is dangerous for humans and the environment, and mechanical weeding is too expensive and labor consuming. Some of the new alternatives for weed control are based on allelopathy, which meets some of the new requirements in modern societies. Allelopathy opens interesting solutions that can be used for a sustainable agriculture and even for organic agriculture. The allelopathy approach does not intend the elimination of weeds but the reasonable control of weed population at low levels that allow a sustainable agricultural production. Allelopathy can be made with alternative crops or with forest or agricultural residues. Some of the plants with allelopathy potential are leguminous such as faba been, but also forest residues as the green leaf of eucalyptus can be capitalized. These are partial solutions that can help in minimizing herbicide applications but further research is required.[ES] La flora arvense es uno de los factores limitantes de la agricultura en climas templados húmedos. El control de la flora arvense es un reto actualmente porque las sociedades más avanzadas rechazan el uso de herbicidas sintéticos ya que suponen un riesgo para la salud humana y el medio ambiente. El control químico es peligroso para las personas y el mecánico es costoso y laborioso. Algunas de las nuevas alternativas para el control de la flora se basan en la alelopatía, que responde a los requisitos actuales de la sociedad. La alelopatía abre soluciones interesantes que pueden ser usadas en agricultura sostenible y ecológica. La solución alelopática no intenta la eliminación de las hierbas sino un control razonable que permita el cultivo con bajas poblaciones de hierbas para una agricultura sostenible. La alelopatía se puede hacer con cultivos alternativos o con residuos agroforestales. Algunas plantas con valor potencial para la alelopatía son las habas, pero también residuos forestales como las hojas verdes de eucalipto pueden ser aprovechadas. Estas soluciones son parciales y pueden ayudar a minimizar la aplicación de herbicidas, pero se requieren más investigaciones.Peer reviewe

Evaluation of the satellite-based Global Flood Detection System for measuring river discharge: Influence of local factors

One of the main challenges for global hydrological modelling is the limited availability of observational data for calibration and model verification. This is particularly the case for real time applications. This problem could potentially be overcome if discharge measurements based on satellite data were sufficiently accurate to substitute for ground-based measurements. The aim of this study is to test the potentials and constraints of the remote sensing signal of the Global Flood Detection System for converting the flood detection signal into river discharge values. The study uses data for 322 river measurement locations in Africa, Asia, Europe, North America and South America. Satellite discharge measurements were calibrated for these sites and a validation analysis with in situ discharge was performed. The locations with very good performance will be used in a future project where satellite discharge measurements are obtained on a daily basis to fill the gaps where real time ground observations are not available. These include several international river locations in Africa: Niger, Volta and Zambezi rivers. Analysis of the potential factors affecting the satellite signal was based on a classification decision tree (Random Forest) and showed that mean discharge, climatic region, land cover and upstream catchment area are the dominant variables which determine good or poor performance of the measurement sites. In general terms, higher skill scores were obtained for locations with one or more of the following characteristics: a river width higher than 1km; a large floodplain area and in flooded forest; with a potential flooded area greater than 40%; sparse vegetation, croplands or grasslands and closed to open and open forest; Leaf Area Index > 2; tropical climatic area; and without hydraulic infrastructures. Also, locations where river ice cover is seasonally present obtained higher skill scores. The work provides guidance on the best locations and limitations for estimating discharge values from these daily satellite signals.JRC.H.7-Climate Risk Managemen

African Swine Fever Virus Uses Macropinocytosis to Enter Host Cells

African swine fever (ASF) is caused by a large and highly pathogenic DNA virus, African swine fever virus (ASFV), which provokes severe economic losses and expansion threats. Presently, no specific protection or vaccine against ASF is available, despite the high hazard that the continued occurrence of the disease in sub-Saharan Africa, the recent outbreak in the Caucasus in 2007, and the potential dissemination to neighboring countries, represents. Although virus entry is a remarkable target for the development of protection tools, knowledge of the ASFV entry mechanism is still very limited. Whereas early studies have proposed that the virus enters cells through receptor-mediated endocytosis, the specific mechanism used by ASFV remains uncertain. Here we used the ASFV virulent isolate Ba71, adapted to grow in Vero cells (Ba71V), and the virulent strain E70 to demonstrate that entry and internalization of ASFV includes most of the features of macropinocytosis. By a combination of optical and electron microscopy, we show that the virus causes cytoplasm membrane perturbation, blebbing and ruffles. We have also found that internalization of the virions depends on actin reorganization, activity of Na+/H+ exchangers, and signaling events typical of the macropinocytic mechanism of endocytosis. The entry of virus into cells appears to directly stimulate dextran uptake, actin polarization and EGFR, PI3K-Akt, Pak1 and Rac1 activation. Inhibition of these key regulators of macropinocytosis, as well as treatment with the drug EIPA, results in a considerable decrease in ASFV entry and infection. In conclusion, this study identifies for the first time the whole pathway for ASFV entry, including the key cellular factors required for the uptake of the virus and the cell signaling involved

The availability and geographic location of open-source food composition data used to estimate micronutrient intakes in sub-Saharan Africa: A scoping review

Background Estimates of dietary micronutrient intakes rely on food composition data. The nutrient composition of foods varies spatially with potentially large effects on dietary micronutrient intakes. This review assessed the availability and geographic origin of five minerals (calcium, iron, iodine, selenium and zinc) in publicly available food composition tables/databases (FCTs) for use in sub-Saharan Africa (SSA). Methods A scoping review was conducted following PRISMA guidelines, in which four databases (MEDLINE, Embase, Global Health and Africa Wide Information) and four online resources were searched to identify published FCTs for use in SSA. Metadata were reviewed to identify the geographic origin of composition values for selected foods. Results Nineteen publicly available FCTs were identified, with the highest geographic coverage in Eastern Africa (45% of countries) and lowest coverage in Central Africa (12% of countries). Iodine and selenium were reported in four and six FCTs, respectively, while iron and calcium were included in ≥ 18 FCTs. More than 60% of nutrient values were borrowed from other FCTs. The geographic origin of 22% of mineral values were documented. Conclusions Limited local food composition analytical data is available, for estimating mineral intakes of SSA populations, with poor documentation of the data sources and the geographic origins of samples. New data structures and improved metadata are required to capture and report geographic information in publicly available FCTs, and to accommodate a new generation of spatially-resolved food composition data

Effect of Thermal Treatment on Corrosion Behavior of AISI 316L Stainless Steel Manufactured by Laser Powder Bed Fusion

The effect of post-processing heat treatment on the corrosion behavior of AISI 316L stainless steel manufactured by laser powder bed fusion (L-PBF) is investigated in this work. Produced stainless steel was heat treated in a broad temperature range (from 200 °C to 1100 °C) in order to evaluate the electrochemical behavior and morphology of corrosion. The electrochemical behavior was investigated by potentiodynamic and galvanostatic polarization in a neutral and acidic (pH 1.8) 3.5% NaCl solution. The microstructure modification after heat treatment and the morphology of attack of corroded samples were evaluated by optical and scanning electron microscopy. The fine cellular/columnar microstructure typically observed for additive-manufactured stainless steel evolves into a fine equiaxed austenitic structure after thermal treatment at high temperatures (above 800 °C). The post-processing thermal treatment does not negatively affect the electrochemical behavior of additive-manufactured stainless steel even after prolonged heat treatment at 1100 °C for 8 h and 24 h. This indicates that the excellent barrier properties of the native oxide film are retained after heat treatment