Search

Aim: The calibration area (CA) corresponds to the geographic region used by different algorithms that estimate the species' environmental preferences and delimit its geographic distribution. This study intended to identify, test and compare current literature's most commonly employed approaches and methods for CA creation, highlighting the differences with the accessible area (M), a frequently misapplied concept. Location: Global. Taxon: Arthropods, amphibians, reptiles, birds and mammals. Methods: We conducted a literature review and analysed 129 recent articles on species distribution that use correlative models to identify the methods used to establish the CA and their frequency. We also evaluated seven of the most widely used methods for 31 species from different taxa. Results: We found that the most frequently used methods in literature corresponded to biogeographic entities (BE). Moreover, according to our evaluation, those methods that seek to establish the CA through the accessible area approach (including BE and 'grinnell') were the best evaluated. Finally, we highlight the advantages and disadvantages of the analysed methods in selecting CA. Main Conclusions: Although we cannot fail to recognize the usefulness and validity of the different methods to establish CAs, we suggest calibrating ecological niche and species distribution models in light of explicit a priori hypotheses regarding the extent of accessible areas (M) as a delimitation of the CA, which theoretically includes the species' dispersal ability and its barriers. We recommend using the BE method, which is simple to establish and highly operational. [ABSTRACT FROM AUTHOR]

Se presenta una metodología que permite el establecimiento de un sistema de indicaciónbiológica para la contaminación orgánica de aguas corrientes sobre la base demacroinvertebrados acuáticos de la Sabana de Bogotá, Colombia - Norte de losAndes. Se asignan valores numéricos de indicación para 57 familias del macrobentosobtenidos con el objeto de cumplir los requerimientos básicos del sistema BMWP,establecido para la bioindicación de contaminación orgánica en Inglaterra y - conciertas modificaciones - en España. El principal objeto de este estudio es expresar elefecto de la contaminación orgánica como un factor ambiental específico más queafecta la distribución de las familias del macrobentos en la región de estudio. Paraeste propósito, el empleo de un promedio ponderado, el cual permite obtener valoresde indicación numérica aplicables y fácilmente reproducibles, resultó ser tan o máseficiente que las técnicas multivariadas de regresión. El estudio se llevó a cabo deacuerdo con el siguiente diseño: 1. Se tomaron muestras en 28 sitios localizados en8 corrientes de agua en alturas de 2550 a 3300 msnm. Se tomaron datos biológicos ydatos fisicoquímicos por un periodo de dos años incluyendo periodos de diferentesniveles de caudal. 2. El macrobentos fue muestreado en diferentes coriotopos(microhábitats). 3. Se ordenaron 18 variables fisicoquímicas mediante un análisis defactores. Nueve de ellas fueron determinadas como componentes del primer factorambiental indicativo de contaminación orgánica. 4. Se calcularon los valores (scores)de calidad fisicoquímica (Cfq) usando las nueve variables fisicoquímicas seleccionadasanteriormente. 5. Los valores de indicación (Tm) que deben corresponder a latolerancia mínima (Tm) a la contaminación orgánica fueron determinados para cadafamilia del macrobentos a través del quinto percentil de la curva de distribuciónnormal ajustada de las abundancias de las familias sobre las diez clases de Cfq. Labase conceptual del procedimiento es la definición y aplicación estrictamente numéricade los valores de indicación y de los índices derivados de ellos para asegurarque sean reproducibles. Las bases de datos están publicadas en el siguente web site‘http://www.encuentro.org/BMWP-Colombia’.

Copyright of Revista Espacios is the property of Talleres de Impresos Oma and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Espacios is the property of Talleres de Impresos Oma and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: Evaluate the effects of i) dehulling of lupine seed on chemical composition and apparent metabolizable energy (AME) and ii) soybean meal substitution by dehulled lupine seed in broiler diets with enzymes on productive performance, size of digestive organs and welfare-related variables. Methods: Experiment 1, chemical composition and AME were determined in whole and dehulled lupine seed. Experiment 2, two hundred eighty-eight one-day-old male Ross 308 broilers were used. The experimental diets were maize-soybean meal (MS), MS with enzymes (MSE) and maize-dehulled lupine seed with enzymes (MLE). Diets were assigned to the experimental units under a completely randomized design (eight replicates per diet). The body weight (BW) gain, feed intake, feed conversion, digestive organ weights, gait score, latency to lie down and valgus/varus angulation were evaluated. Results: The dehulling process increased protein (25.0% to 31.1%), AME (5.9 to 8.8 MJ/kg) and amino acid contents. The BW gain of broilers fed the MLE diet was similar (p>0.05) to that of those fed the MS diet, but lower than that of those fed the MSE diet. Feed intake of broilers fed the MLE diet was higher (p<0.05) than that of those fed the MS diet and similar (p>0.05) to those fed the MSE diet. Feed conversion of broilers fed the MLE diet was 8.0% and 8.7% higher (p<0.05) than that of those fed the MS and MSE diets, respectively. Broilers fed the MLE diet had the highest (p<0.05) relative proventriculus and gizzard weights, but had poor welfare-related variables. Conclusion: It is possible to substitute soybean meal by dehulled lupine seed with enzymes in broiler diets, obtaining similar BW gains in broilers fed the MLE and MS diets; however, a higher feed intake is required. Additionally, the MLE diet reduced welfare-related variables. [ABSTRACT FROM AUTHOR]

Copyright of Agrociencia is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Under an electric field, spherical conducting particles in a dielectric liquid assemble into a dendritic tree in order to dissipate charge. Several topological measures characterize such networks, including degree distributions, Strahler numbers, and total external pathlengths. Here, scaling laws relating these measures to the number of nodes in the system are presented and shown to match diffusion limited aggregation (DLA) structures. Experimental bifurcation and stream-length ratios in this easily reproducible laboratory experiment are found to agree with DLA simulations and Horton's laws for river networks. Certain scaling relations in transportation networks are known to originate from general features of networks. Here we find the experimental structures share properties with hydrological drainage networks. [ABSTRACT FROM AUTHOR]

Copyright of Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas is the property of Universidad de Santiago de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas is the property of Universidad de Santiago de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Myofibroblasts are the major source of extracellular matrix components that accumulate during tissue fibrosis, and hepatic stellate cells (HSCs) are the major source of myofibroblasts in the liver. To date, robust systems to genetically manipulate these cells have not existed. We report that Pdgfrb-Cre inactivates genes in murine HSCs with high efficiency. We used this system to delete the αv integrin subunit because of the suggested role of multiple αv integrins as central mediators of fibrosis in multiple organs. Depletion of the αv integrin subunit in HSCs protected mice from CCl4-induced hepatic fibrosis, whereas global loss of αvβ3, αvβ5 or αvβ6 or conditional loss of αvβ8 on HSCs did not. Pdgfrb-Cre effectively targeted myofibroblasts in multiple organs, and depletion of αv integrins using this system was also protective in models of pulmonary and renal fibrosis. Critically, pharmacological blockade of αv integrins by a novel small molecule (CWHM 12) attenuated both liver and lung fibrosis, even when administered after fibrosis was established. These data identify a core pathway that regulates fibrosis, and suggest that pharmacological targeting of all αv integrins may have clinical utility in the treatment of patients with a broad range of fibrotic diseases.

An abstract of the article "Interaction of gypsum with As(V)-bearing aqueous solutions: Surface precipitation of guerinite, saifeldite, and Ca2NaH(AsO4)2·6H2O, a synthetic arsenate," by Manuel Prieto, Laura Torre, and Santiago García-Granda is presented.