Convergencia de vías de señalización en un modelo de apoptosis

La sepsis es un evento inflamatorio generalizado del organismo inducido por un daño causado generalmente por un agente infeccioso. El patógeno más frecuentemente asociado con esta entidad es el Staphylococcus aureus, responsable de la inducción de apoptosis en células endoteliales debida a la producción de ceramida. Se ha descrito el efecto protector de la proteína C activada (PCA) en sepsis y su relación con la disminución de la apoptosis de las células endoteliales. En este trabajo se analizó la activación de las quinasas AKT, ASK1, SAPK/JNK y p38 en un modelo de apoptosis endotelial usando las técnicas de Western Blotting y ELISA. Las células endoteliales (EA.hy926), se trataron con C2-ceramida (130μM) en presencia de inhibidores químicos de cada una de estas quinasas y PCA. La supervivencia de las células en presencia de inhibidores químicos y PCA fue evaluada por medio de ensayos de activación de las caspasas 3, 7 y 9, que verificaban la muerte celular por apoptosis. Los resultados evidencian que la ceramida reduce la activación de AKT y aumenta la activación de las quinasas ASK, SAPK/JNK y p38, en tanto que PCA ejerce el efecto contrario. Adicionalmente se encontró que la tiorredoxina incrementa la activación/fosforilación de AKT, mientras que la quinasa p38 induce la defosforilación de AKT.

La experiencia del proceso de desarrollo e internacionalización de las zonas francas industriales y comerciales colombianas

Entrar al análisis de los factores de liderazgo de las zonas francas de Colombia, República Dominicana y Taiwán, resulta básico abordar el tema del liderazgo empresarial, como la estructura principal del éxito en las organizaciones del mundo

Les sHsps en surera: Estudis de funcionalitat

Aquesta tesi es centra en la caracterització funcional d'una proteïna de xoc de calor de baix pes molecular (Small Heat Shock Protein - sHSP) de classe I de surera pel que fa a la seva capacitat per protegir les cèl·lules de l'estrès i per estabilitzar les membranes. Les sHsps són proteïnes que s'expressen en condicions d'estrès cel·lular. Encara que certs aspectes funcionals de les sHsps són ben coneguts, el nostre treball aporta informacions noves sobre el paper de les diferents regions de la proteïna, especialment de la regió N-terminal. L'objectiu concret d'aquest treball és determinar la funció termoprotectora de QsHsp17.4-CI, una sHsp de classe I oobtinguda a partir de les cèl·lules de fel·lema d'alzina surera, en un model bacterià i analitzar la importància de les diferents regions de la proteïna en aquesta funció. Amb aquesta finalitat s'han dissenyat dues proteïnes parcials derivades de QsHsp17.4-CI: una a la que li falta la regió N-terminal (C105) i una altra amb pràcticament tot el domini -cristal·lí deleccionat (N61), i una tercera, derivada de QsHs10-CI, a la que li falta la meitat del domini -cristal·lí (Hsp10). També s'estudia la possible capacitat estabilitzadora de membranes i la capacitat de modificar l'expressió d'altres Hsps quan s'expressa de forma heteròloga. Els nostres resultats demostren que l'expressió de QsHsp17.4-CI protegeix a les cèl·lules d'E.coli de l'estrès tèrmic alhora que la regió N-terminal i la regió consens II del domini -cristal·lí són imprescindibles per aquesta funció de protecció. En relació a un possible paper en les membranes, els estudis de localització subcel·lular mostren que QsHsp17.4-CI colocalitza amb la fracció membranes i que la regió N-terminal de la proteïna és responsable d'aquesta colocalització. No s'ha pogut demostrar, però, que la localització amb la membrana estigui associada a un efecte protector d'aquesta: en cap cas la sobrexpressió de les proteïnes modifica la composició d'àcids grassos i només N61, que no té acció termoprotectora, altera l'estat fisico-químic de la membrana. En estudis d'expressió de novo en E.coli s'ha observat que, a diferència de les altres proteïnes heteròlogues, N61 activa l'expressió de la majoria de Hsps d'E.coli fent pensar en una possible relació entre l'estat físic de la membrana i l'activació de la resposta a l'estrès. En resum, en aquest treball hem provat la capacitat protectora de QsHsp17.4 i aportem noves dades sobre la importància de la regió N-terminal i la regió consens II del domini -cristal·lí en aquesta funció. Per altra banda, es suggereix que QsHsp17.4 podria interaccionar amb la membrana d'E.coli i que la regió N-terminal seria imprescindible per aquesta interacció. Finalment hem determinat que les proteïnes que provoquen variacions en l'estat de fluïdesa de la membrana poden activar la resposta al xoc de calor per part de la cèl·lula bacteriana.

Impacto da tomografia computorizada versus radiografia no prognóstico pós-cirúrgico do carcinoma espinocelular oral no cão

Objectivos: Neste estudo retrospectivo pretendeu-se determinar o impacto da tomografia computorizada na sobrevivência pós-cirúrgica do cão com carcinoma espinocelular na cavidade oral, comparativamente à radiografia. Enfatizando desta forma, a sua importância no diagnóstico, no planeamento cirúrgico e prognóstico. O segundo objectivo consistiu em determinar as características tomográficas dos carcinomas espinocelulares da cavidade oral em cães. Material e Métodos: Foram analisados 7 canídeos com diagnóstico de carcinoma espinocelular. Os critérios de inclusão foram: cães com carcinoma espinocelular diagnosticado por biópsia, exame imagiológico complementar (radiografia simples ou tomografia computorizada), elegibilidade para cirurgia, execução de tratamento cirúrgico e acompanhamento pós-cirúrgico durante 2 anos. Foi registada a idade, o sexo, a raça, a localização anatómica, o estadiamento T e N, as características radiográficas e tomográficas dos tumores, o tempo de recorrência e por fim o tempo de sobrevivência global descrito nos registos consultados. Procedeu-se também ao registo das variáveis das imagens radiográficas e tomográficas obtidas: definição das margens neoplásicas, presença ou ausência de reacção perióstea e de destruição de osso cortical adjacente, presença de deslocação dentária e de reabsorção dentária e densidade óssea local. Resultados: Nenhum dos meios imagiológicos permitiu uma visualização bem definida das margens neoplásicas. A nível da destruição de osso cortical adjacente, foi visível em 66,67% dos casos avaliados com radiografia e em todos os casos que foram avaliados com tomografia computorizada (100%). Foi visível reacção perióstea em 33,33% dos canídeos avaliados por radiografia e em nenhum dos avaliados por tomografia (0%). A densidade óssea local estava diminuída em todos os casos avaliados por radiografia simples ou por tomografia. A nível de reabsorção dentária estava presente em 33,33% dos avaliados por radiografia e em 25% dos avaliados por tomografia. Foi possível visualizar deslocação dentária em 66,67% dos avaliados por radiografia e em todos os avaliados por tomografia (100%). A nível de percentagem de casos com recorrência local, nenhum caso avaliado com radiografia recorreu e apenas 1 caso avaliado por tomografia recorreu em 289 dias. O tempo médio de sobrevivência foi superior no grupo dos avaliados com radiografia (1091,7 dias) relativamente ao grupo avaliado por tomografia (404 dias). Ao fim de 2 anos, 66,67% dos casos avaliados por radiografia estavam vivos e somente 25% dos casos avaliados com tomografia sobreviveram. Discussão/conclusão: Não foi possível determinar o impacto real dos dois meios de diagnóstico no prognóstico pós-cirúrgico do carcinoma espinocelular oral no cão, devido à reduzida amostra e aos tumores com pior prognóstico (por localização e estadiamento) terem sido remetidos para tomografia.

Identidade, imaginário e cotidiano: concepções de alunos e professores numa escola do Nordeste do Brasil

O presente trabalho tem como objetivo investigar as concepções escolares, apresentando uma discussão do ponto de vista teórico-metodológico acerca destas construções produzidas no âmbito escolar, através de pesquisa etnográfica, utilizando o grupo focal, levando em conta a formação ideológica (ideias sobre si, o interlocutor e o assunto) e a formação discursiva (as marcas linguísticas, temáticas e de posição ideológica) dos participantes desta pesquisa. Por meio dos posicionamentos nas categorias: identidade, cotidiano e imaginário; pudemos observar que os discursos adquirem sentido à medida que são produzidos e que carregam em si os significados que expressam idéias, sentimentos e comportamentos. As mudanças de sentido ocorrem através de outros discursos que dialogam em um processo de construção e reconstrução. Neste entremeio o indivíduo revela-se inserido sócio-culturalmente. E a escola como espaço dinâmico é preenchida de sentido e dá novos sentidos, ora reproduzindo discursos, ora reconstruindo-os, ora formulando novos. Analisando os dados da pesquisa realizada, apreendemos que os discursos de educadores e educandos são influenciados uns pelos outros, formados pelas práticas cotidianas e pela bagagem social que cada indivíduo tem. Nessa construção mútua no processo de convívio, os papeis estabelecidos pela instituição escolar ganham novos contornos e limites no percalço do ensino-aprendizagem, não podendo separar deste contexto os elementos individuais que a escola torna coletivo e que traçam um caminho discursivo novo e ao mesmo tempo pertencente desde antes aos que fazem parte da escola.

Incorporating Legacy Soil pH Databases into Digital Soil Maps

Soil data and reliable soil maps are imperative for environmental management. conservation and policy. Data from historical point surveys, e.g. experiment site data and farmers fields can serve this purpose. However, legacy soil information is not necessarily collected for spatial analysis and mapping such that the data may not have immediately useful geo-references. Methods are required to utilise these historical soil databases so that we can produce quantitative maps of soil propel-ties to assess spatial and temporal trends but also to assess where future sampling is required. This paper discusses two such databases: the Representative Soil Sampling Scheme which has monitored the agricultural soil in England and Wales from 1969 to 2003 (between 400 and 900 bulked soil samples were taken annually from different agricultural fields); and the former State Chemistry Laboratory, Victoria, Australia where between 1973 and 1994 approximately 80,000 soil samples were submitted for analysis by farmers. Previous statistical analyses have been performed using administrative regions (with sharp boundaries) for both databases, which are largely unrelated to natural features. For a more detailed spatial analysis that call be linked to climate and terrain attributes, gradual variation of these soil properties should be described. Geostatistical techniques such as ordinary kriging are suited to this. This paper describes the format of the databases and initial approaches as to how they can be used for digital soil mapping. For this paper we have selected soil pH to illustrate the analyses for both databases.

Determining nugget: sill ratios of standardized variograms from aerial photographs to krige sparse soil data

Maps of kriged soil properties for precision agriculture are often based on a variogram estimated from too few data because the costs of sampling and analysis are often prohibitive. If the variogram has been computed by the usual method of moments, it is likely to be unstable when there are fewer than 100 data. The scale of variation in soil properties should be investigated prior to sampling by computing a variogram from ancillary data, such as an aerial photograph of the bare soil. If the sampling interval suggested by this is large in relation to the size of the field there will be too few data to estimate a reliable variogram for kriging. Standardized variograms from aerial photographs can be used with standardized soil data that are sparse, provided the data are spatially structured and the nugget:sill ratio is similar to that of a reliable variogram of the property. The problem remains of how to set this ratio in the absence of an accurate variogram. Several methods of estimating the nugget:sill ratio for selected soil properties are proposed and evaluated. Standardized variograms with nugget:sill ratios set by these methods are more similar to those computed from intensive soil data than are variograms computed from sparse soil data. The results of cross-validation and mapping show that the standardized variograms provide more accurate estimates, and preserve the main patterns of variation better than those computed from sparse data.

Erythropoietin mimics the acute phase response in critical illness

Background: In a prospective observational study, we examined the temporal relationships between serum erythropoietin (EPO) levels, haemoglobin concentration and the inflammatory response in critically ill patients with and without acute renal failure (ARF). Patients and method Twenty-five critically ill patients, from general and cardiac intensive care units (ICUs) in a university hospital, were studied. Eight had ARF and 17 had normal or mildly impaired renal function. The comparator group included 82 nonhospitalized patients with normal renal function and varying haemoglobin concentrations. In the patients, levels of haemoglobin, serum EPO, C-reactive protein, IL-1β, IL-6, serum iron, ferritin, vitamin B12 and folate were measured, and Coombs test was performed from ICU admission until discharge or death. Concurrent EPO and haemoglobin levels were measured in the comparator group. Results: EPO levels were initially high in patients with ARF, falling to normal or low levels by day 3. Thereafter, almost all ICU patients demonstrated normal or low EPO levels despite progressive anaemia. IL-6 exhibited a similar initial pattern, but levels remained elevated during the chronic phase of critical illness. IL-1β was undetectable. Critically ill patients could not be distinguished from nonhospitalized anaemic patients on the basis of EPO levels. Conclusion: EPO levels are markedly elevated in the initial phase of critical illness with ARF. In the chronic phase of critical illness, EPO levels are the same for patients with and those without ARF, and cannot be distinguished from noncritically ill patients with varying haemoglobin concentrations. Exogenous EPO therapy is unlikely to be effective in the first few days of critical illness.

Modelling complex systems for project planning - A semiotics motivated method

A large and complex IT project may involve multiple organizations and be constrained within a temporal period. An organization is a system comprising of people, activities, processes, information, resources and goals. Understanding and modelling such a project and its interrelationship with relevant organizations are essential for organizational project planning. This paper introduces the problem articulation method (PAM) as a semiotic method for organizational infrastructure modelling. PAM offers a suite of techniques, which enables the articulation of the business, technical and organizational requirements, delivering an infrastructural framework to support the organization. It works by eliciting and formalizing (e. g. processes, activities, relationships, responsibilities, communications, resources, agents, dependencies and constraints) and mapping these abstractions to represent the manifestation of the "actual" organization. Many analysts forgo organizational modelling methods and use localized ad hoc and point solutions, but this is not amenable for organizational infrastructures modelling. A case study of the infrared atmospheric sounding interferometer (IASI) will be used to demonstrate the applicability of PAM, and to examine its relevancy and significance in dealing with the innovation and changes in the organizations.

A climate change risk analysis for world ecosystems

We quantify the risks of climate-induced changes in key ecosystem processes during the 21st century by forcing a dynamic global vegetation model with multiple scenarios from 16 climate models and mapping the proportions of model runs showing forest/nonforest shifts or exceedance of natural variability in wildfire frequency and freshwater supply. Our analysis does not assign probabilities to scenarios or weights to models. Instead, we consider distribution of outcomes within three sets of model runs grouped by the amount of global warming they simulate: <2°C (including simulations in which atmospheric composition is held constant, i.e., in which the only climate change is due to greenhouse gases already emitted), 2–3°C, and >3°C. High risk of forest loss is shown for Eurasia, eastern China, Canada, Central America, and Amazonia, with forest extensions into the Arctic and semiarid savannas; more frequent wildfire in Amazonia, the far north, and many semiarid regions; more runoff north of 50°N and in tropical Africa and northwestern South America; and less runoff in West Africa, Central America, southern Europe, and the eastern U.S. Substantially larger areas are affected for global warming >3°C than for <2°C; some features appear only at higher warming levels. A land carbon sink of ≈1 Pg of C per yr is simulated for the late 20th century, but for >3°C this sink converts to a carbon source during the 21st century (implying a positive climate feedback) in 44% of cases. The risks continue increasing over the following 200 years, even with atmospheric composition held constant.

Land-cover classification from airborne LIDAR data fused with aerial optical images

Airborne LIght Detection And Ranging (LIDAR) provides accurate height information for objects on the earth, which makes LIDAR become more and more popular in terrain and land surveying. In particular, LIDAR data offer vital and significant features for land-cover classification which is an important task in many application domains. In this paper, an unsupervised approach based on an improved fuzzy Markov random field (FMRF) model is developed, by which the LIDAR data, its co-registered images acquired by optical sensors, i.e. aerial color image and near infrared image, and other derived features are fused effectively to improve the ability of the LIDAR system for the accurate land-cover classification. In the proposed FMRF model-based approach, the spatial contextual information is applied by modeling the image as a Markov random field (MRF), with which the fuzzy logic is introduced simultaneously to reduce the errors caused by the hard classification. Moreover, a Lagrange-Multiplier (LM) algorithm is employed to calculate a maximum A posteriori (MAP) estimate for the classification. The experimental results have proved that fusing the height data and optical images is particularly suited for the land-cover classification. The proposed approach works very well for the classification from airborne LIDAR data fused with its coregistered optical images and the average accuracy is improved to 88.9%.

A data framework for measuring the energy consumption of the non-domestic building stock

The transition to a low-carbon economy urgently demands better information on the drivers of energy consumption. UK government policy has prioritized energy efficiency in the built stock as a means of carbon reduction, but the sector is historically information poor, particularly the non-domestic building stock. This paper presents the results of a pilot study that investigated whether and how property and energy consumption data might be combined for non-domestic energy analysis. These data were combined in a ‘Non-Domestic Energy Efficiency Database’ to describe the location and physical attributes of each property and its energy consumption. The aim was to support the generation of a range of energy-efficiency statistics for the industrial, commercial and institutional sectors of the non-domestic building stock, and to provide robust evidence for national energy-efficiency and carbon-reduction policy development and monitoring. The work has brought together non-domestic energy data, property data and mapping in a ‘data framework’ for the first time. The results show what is possible when these data are integrated and the associated difficulties. A data framework offers the potential to inform energy-efficiency policy formation and to support its monitoring at a level of detail not previously possible.

Global burned-land estimation in Latin America using MODIS composite data

This paper presents results of the AQL2004 project, which has been develope within the GOFC-GOLD Latin American network of remote sensing and forest fires (RedLatif). The project intended to obtain monthly burned-land maps of the entire region, from Mexico to Patagonia, using MODIS (moderate-resolution imaging spectroradiometer) reflectance data. The project has been organized in three different phases: acquisition and preprocessing of satellite data; discrimination of burned pixels; and validation of results. In the first phase, input data consisting of 32-day composites of MODIS 500-m reflectance data generated by the Global Land Cover Facility (GLCF) of the University of Maryland (College Park, Maryland, U.S.A.) were collected and processed. The discrimination of burned areas was addressed in two steps: searching for "burned core" pixels using postfire spectral indices and multitemporal change detection and mapping of burned scars using contextual techniques. The validation phase was based on visual analysis of Landsat and CBERS (China-Brazil Earth Resources Satellite) images. Validation of the burned-land category showed an agreement ranging from 30% to 60%, depending on the ecosystem and vegetation species present. The total burned area for the entire year was estimated to be 153 215 km2. The most affected countries in relation to their territory were Cuba, Colombia, Bolivia, and Venezuela. Burned areas were found in most land covers; herbaceous vegetation (savannas and grasslands) presented the highest proportions of burned area, while perennial forest had the lowest proportions. The importance of croplands in the total burned area should be taken with reserve, since this cover presented the highest commission errors. The importance of generating systematic products of burned land areas for different ecological processes is emphasized.

Still searching for graves: an analytical strategy for interpreting geophysical data used in the search for “unmarked” graves

Searching for and mapping the physical extent of unmarked graves using geophysical techniques has proven difficult in many cases. The success of individual geophysical techniques for detecting graves depends on a site-by-site basis. Significantly, detection of graves often results from measured contrasts that are linked to the background soils rather than the type of archaeological feature associated with the grave. It is evident that investigation of buried remains should be considered within a 3D space as the variation in burial environment can be extremely varied through the grave. Within this paper, we demonstrate the need for a multi-method survey strategy to investigate unmarked graves, as applied at a “planned” but unmarked pauper’s cemetery. The outcome from this case study provides new insights into the strategy that is required at such sites. Perhaps the most significant conclusion is that unmarked graves are best understood in terms of characterization rather than identification. In this paper, we argue for a methodological approach that, while following the current trends to use multiple techniques, is fundamentally dependent on a structured approach to the analysis of the data. The ramifications of this case study illustrate the necessity of an integrated strategy to provide a more holistic understanding of unmarked graves that may help aid in management of these unseen but important aspects of our heritage. It is concluded that the search for graves is still a current debate and one that will be solved by methodological rather than technique-based arguments.

Flood Risk Assessment in Coastal Drainage Basins through a Multivariate Analysis within a GIS-Based Model

This paper presents a GIS-based multicriteria flood risk assessment and mapping approach applied to coastal drainage basins where hydrological data are not available. It involves risk to different types of possible processes: coastal inundation (storm surge), river, estuarine and flash flood, either at urban or natural areas, and fords. Based on the causes of these processes, several environmental indicators were taken to build-up the risk assessment. Geoindicators include geological-geomorphologic proprieties of Quaternary sedimentary units, water table, drainage basin morphometry, coastal dynamics, beach morphodynamics and microclimatic characteristics. Bioindicators involve coastal plain and low slope native vegetation categories and two alteration states. Anthropogenic indicators encompass land use categories properties such as: type, occupation density, urban structure type and occupation consolidation degree. The selected indicators were stored within an expert Geoenvironmental Information System developed for the State of Sao Paulo Coastal Zone (SIIGAL), which attributes were mathematically classified through deterministic approaches, in order to estimate natural susceptibilities (Sn), human-induced susceptibilities (Sa), return period of rain events (Ri), potential damages (Dp) and the risk classification (R), according to the equation R=(Sn.Sa.Ri).Dp. Thematic maps were automatically processed within the SIIGAL, in which automata cells (""geoenvironmental management units"") aggregating geological-geomorphologic and land use/native vegetation categories were the units of classification. The method has been applied to the Northern Littoral of the State of Sao Paulo (Brazil) in 32 small drainage basins, demonstrating to be very useful for coastal zone public politics, civil defense programs and flood management.