667 research outputs found
What species-specific traits make a bird a better surrogate of native species richness? A test with insular avifauna
This is an electronic version of an article published in Biological Conservation. Carrascal, L.M. et al. What species-specific traits make a bird a better surrogate of native species richness? A test with insular avifauna. Biological Conservation 152 (2012): 204-21
Application of the dual-luciferase reporter assay to the analysis of promoter activity in Zebrafish embryos
<p>Abstract</p> <p>Background</p> <p>The dual-luciferase assay has been widely used in cell lines to determine rapidly but accurately the activity of a given promoter. Although this strategy has proved very useful, it does not allow the promoter and gene function to be analyzed in the context of the whole organism.</p> <p>Results</p> <p>Here, we present a rapid and sensitive assay based on the classical dual-luciferase reporter technique which can be used as a new tool to characterize the minimum promoter region of a gene as well as the <it>in vivo </it>response of inducible promoters to different stimuli. We illustrate the usefulness of this system for studying both constitutive (telomerase) and inducible (NF-κB-dependent) promoters. The flexibility of this assay is demonstrated by induction of the NF-κB-dependent promoters using simultaneous microinjection of different pathogen-associated molecular patterns as well as with the use of morpholino-gene mediated knockdown.</p> <p>Conclusion</p> <p>This assay has several advantages compared with the classical <it>in vitro </it>(cell lines) and <it>in vivo </it>(transgenic mice) approaches. Among others, the assay allows a rapid and quantitative measurement of the effects of particular genes or drugs in a given promoter in the context of a whole organism and it can also be used in high throughput screening experiments.</p
Overcoming biochar limitations to remediate pentachlorophenol in soil by modifying its electrochemical properties
In this study, we produced modified biochars with enhanced electrochemical properties to increase PCP remediation in soil. Although all biochars enhanced PCP remediation in aerobic conditions, only a few did in anaerobic soil. The most successful modifications were (i) the preloading of biomass with 10% w/w FeCl3, to obtain a biochar rich in redox-active metals (B-Fe); (ii) the oxidation of a conductive biochar pyrolyzed at 1000 ºC with 0.025 M KMnO4, to produce a biochar with both moderate conductivity and redox capacity (B-1000-KMnO4); and (iii) KMnO4 oxidation of an amorphous biochar pyrolyzed at 400 ºC to obtain a biochar with very high redox capacity (B-KMnO4). B-Fe reduced extractable PCP to almost zero after 50 days in both incubations, but showed slow kinetics of remediation in aerobic soil. B-1000-KMnO4 had the highest rate of remediation under aerobic conditions, but no significant effect under anaerobic conditions. B-KMnO4, however, presented high rates of remediation and high removal of extractable PCP under both conditions, which made it the recommended modification strategy for increased PCP remediation. We found that the degree of remediation primarily depends on the redox capacity, while the rate of remediation was determined by both the conductivity and redox capacity of biochar
El ensayo de solubilidad diferencial como método de caracterización de la estructura fina de las fibras químicas
La solubilidad diferencial es un ensayo físico-químico para la caracterización de la estructura fina de las fibras de poliéster, poliamida, acrílicas y fibras químicas de celulosa. En esta publicación se describe esta técnica, así como la influencia de las variables del ensayo. También se interpreta la curva de solubilidad diferencial vs. temperatura del ensayo. Por último, se citan ejemplos de campos de aplicación de este ensayo a diferentes grupos de sustratos de las mencionadas fibras
Species distribution modeling in the tropics: problems, potentialities, and the role of biological data for effective species conservation
In this paper we aim to investigate the problems and potentialities of species distribution modeling (SDM) as a tool for conservation planning and policy development and implementation in tropical regions. We reviewed 123 studies published between 1995 and 2007 in five of the leading journals in ecology and conservation, and examined two tropical case studies in which distribution modeling is currently being applied to support conservation planning. We also analyzed the characteristics of data typically used for fitting models within the specific context of modeling tree species distribution in Central America. The results showed that methodological papers outnumbered reports of SDMs being used in an applied context for setting conservation priorities, particularly in the tropics. Most applications of SDMs were in temperate regions and biased towards certain organisms such as mammals and birds. Studies from tropical regions were less likely to be validated than those from temperate regions. Unpublished data from two major tropical case studies showed that those species that are most in need of conservation actions, namely those that are the rarest or most threatened, are those for which SDM is least likely to be useful. We found that only 15% of the tree species of conservation concern in Central America could be reliably modelled using data from a substantial source (Missouri Botanical Garden VAST database). Lack of data limits model validation in tropical areas, further restricting the value of SDMs. We concluded that SDMs have a great potential to support biodiversity conservation in the tropics, by supporting the development of conservation strategies and plans, identifying knowledge gaps, and providing a tool to examine the potential impacts of environmental change. However, for this potential to be fully realized, problems of data quality and availability need to be overcome. Weaknesses in current biological datasets need to be systematically addressed, by increasing collection of field survey data, improving data sharing and increasing structural integration of data sources. This should include use of distributed databases with common standards, referential integrity, and rigorous quality control. Integration of data management with SDMs could significantly add value to existing data resources by improving data quality control and enabling knowledge gaps to be identified
Population position along the fast–slow life‐history continuum predicts intraspecific variation in actuarial senescence
International audienc
Zebrafish modeling reveals that SPINT1 regulates the aggressiveness of skin cutaneous melanoma and its crosstalk with tumor immune microenvironment
Background
Skin cutaneous melanoma (SKCM) is the most lethal form of skin cancer and while incidence rates are declining for most cancers, they have been steadily rising for SKCM. Serine protease inhibitor, kunitz-type, 1 (SPINT1) is a type II transmembrane serine protease inhibitor that has been shown to be involved in the development of several types of cancer, such as squamous cell carcinoma and colorectal cancer.
Methods
We used the unique advantages of the zebrafish to model the impact of Spint1a deficiency in early transformation, progression and metastatic invasion of SKCM together with in silico analysis of the occurrence and relevance of SPINT1 genetic alterations of the SKCM TCGA cohort.
Results
We report here a high prevalence of SPINT1 genetic alterations in SKCM patients and their association with altered tumor immune microenvironment and poor patient survival. The zebrafish model reveals that Spint1a deficiency facilitates oncogenic transformation, regulates the tumor immune microenvironment crosstalk, accelerates the onset of SKCM and promotes metastatic invasion. Notably, Spint1a deficiency is required at both cell autonomous and non-autonomous levels to enhance invasiveness of SKCM.
Conclusions
These results reveal a novel therapeutic target for SKCM
Efecto de la refrigeración sobre la maduración del fruto del chirimoyo
Cherimoya fruits have a typically climateric ripening characterized, among other parameters, by a peak in the ethylene production that produces the senescence. Several attempts have been made in our Department in order to extend the shelf life of the fruits, but sorne undesirable reactions affecting the flavour are always produced. The most simple and natural treatment is the control of the storage temperature. With sorne precautions, it allows a considerable delay in the onset of senescence, making possible the marketing of the fruits in, previously, inaccessible markets.El fruto del chirimoyo presenta una maduración típicamente climatérica caracterizada, entre otros parámetros, por un pico muy acentuado de producción de etileno que conduce a la rápida senescencia. Varios intentos se han hecho en nuestro Departamento para tratar de prolongar la vida comercial de los frutos, pero en todos ellos se producen algunas reacciones indeseables que afectan a la palatabilidad. El tratamiento más natural es el control de la temperatura de almacenamiento, que con ciertas precauciones permite un retardo en la aparición de la senescencia, suficiente para alcanzar mercados de otra forma inaccesibles
Efecto de la refrigeración sobre la maduración del fruto del chirimoyo
El fruto del chirimoyo presenta una maduración típicamente climatérica caracterizada, entre otros parámetros, por un pico muy acentuado de producción de
etileno que conduce a la rápida senescencia. Varios intentos se han hecho en
nuestro Departamento para tratar de prolongar la vida comercial de los frutos, pero
en todos ellos se producen algunas reacciones indeseables que afectan a la
palatabilidad. El tratamiento más natural es el control de la temperatura de
almacenamiento, que con ciertas precauciones permite un retardo en la aparición de
la senescencia, suficiente para alcanzar mercados de otra forma inaccesibles.Cherimoya fruits have a typically climateric ripening characterized, among
other parameters, by a peak in the ethylene production that produces the senescence.
Several attempts have been made in our Department in order to extend the shelf life
of the fruits, but sorne undesirable reactions affecting the flavour are always
produced. The most simple and natural treatment is the control of the storage
temperature. With sorne precautions, it allows a considerable delay in the onset of
senescence, making possible the marketing of the fruits in, previously, inaccessible
markets
Wind speed time series reconstruction using a hybrid neural genetic approach
Currently, electric energy is used in practically all modern human activities. Most of the energy produced came from fossil fuels, making irreversible damage to the environment. Lately, there has been an effort by nations to produce energy using clean methods, such as solar and wind energy, among others. Wind energy is one of the cleanest alternatives. However, the wind speed is not constant, making the planning and operation at electric power systems a difficult activity. Knowing in advance the amount of raw material (wind speed) used for energy production allows us to estimate the energy to be generated by the power plant, helping the maintenance planning, the operational management, optimal operational cost. For these reasons, the forecast of wind speed becomes a necessary task. The forecast process involves the use of past observations from the variable to forecast (wind speed). To measure wind speed, weather stations use devices called anemometers, but due to poor maintenance, connection error, or natural wear, they may present false or missing data. In this work, a hybrid methodology is proposed, and it uses a compact genetic algorithm with an artificial neural network to reconstruct wind speed time series. The proposed methodology reconstructs the time series using a ANN defined by a Compact Genetic Algorithm.Postprint (author's final draft
- …