2,225 research outputs found

    El impacto ambiental del desarrollo del turismo en las islas del archipiélago Jardines del Rey, Cuba

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    The quick process of tourist development undertaken in the  Archipiélago Jardines del Rey, in the Republic of Cuba, represents a potential factor of environmental interference  for the smalls islands that integrate this insular system; these geosystemes are characterized by their notables natural values, high degree of natural conservation, important geoecologys functions and particular natural fragility what makes them spcecially vulnerable before the human impacts. Presenly work, the islands of this archipielago are characterized and is carried out the analysis of the impact waited by the tourist development in the same ones, like a contribution to the clarification of the problem environmental perspective and to alert about the necessity of working in the prevention and evaluation of these aspects, it stops by means of the environmental planning to guarantee the protection of the islands.El acelerado proceso de desarrollo turístico empremdido en el archipiélago Jardines del Rey, en la RepUblica de Cuba, representa un potencial factor de perturbación ambiental para las pequeñas islas que integran este sistema insular. Estos geosistemas se caracterizan por sus notables valores naturales, alto grado de conservación natural, importantes funciones geoecológicas y particular fragilidad natural; lo que los hace especialmente vulnerables ante los impactos humanos. En el presente trabajo, se caracterizan las islas de este archipiélago y se realiza el análisis del impacto esperado por el desarrollo turístico en las mismas, como una contribución al esclarecimiento de la problemática ambiental futura y para alertar sobre la necesidad de trabajar en la prevención y evaluación de estos problemas, por medio de la planificación ambiental para garantizar así la protección de las islas

    La evolución climática a largo plazo y evaluación de la seguridad

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    El concepto de almacenamiento geológico profundo para residuos radiactivos de alta actividad basa una parte importante de su seguridad a largo plazo en el comportamiento del medio geológico. De aquí que los estudios de seguridad post-clausura de tales almacenamientos deban contemplar la necesidad de cuantificar los procesos susceptibles de intervenir en la liberación y el transporte de los radionucleidos desde el propio almacenamiento hasta la biosfera, y las modificaciones importantes que esta última pueda sufrir debido tanto a factores naturales como antropogénicos, durante los periodos de tiempo del orden de cientos de miles de años en que se cifra la duración de la liberación de radionucleido

    Flow Regimes in Fine Cohesive Powders

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    Granular materials exhibit several regimes of behavior: plastic, inertial, fluidized, and entrained flow, but not all materials can pass through all of these states. Our concern is with the criteria that determine the transition from one regime to another and with the boundaries to the various flow regimes that these criteria define. Experimentally we have focused on fine, cohesive powders, where the interparticle cohesive force dominates over gravitational force and where entrained air can cause moving powder to become fluidized

    Opioid pain medication prescription for chronic pain in primary care centers: the roles of pain acceptance, pain intensity, depressive symptoms, pain catastrophizing, sex, and age

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    Background: Psychological factors of patients may influence physicians’ decisions on prescribing opioid analgesics. However, few studies have sought to identify these factors. The present study had a double objective: (1) To identify the individual factors that differentiate patients who had been prescribed opioids for the management of chronic back pain from those who had not been prescribed opioids and (2) to determine which factors make significant and independent contributions to the prediction of opioid prescribing. Methods: A total of 675 patients from four primary care centers were included in the sample. Variables included sex, age, pain intensity, depressive symptoms, pain catastrophizing, and pain acceptance. Results: Although no differences were found between men and women, participants with chronic noncancer pain who were prescribed opioids were older, reported higher levels of pain intensity and depressive symptoms, and reported lower levels of pain-acceptance. An independent association was found between pain intensity and depressive symptoms and opioid prescribing. Conclusions: The findings suggest that patient factors influence physicians’ decisions on prescribing opioids. It may be useful for primary care physicians to be aware of the potential of these factors to bias their treatment decisions.info:eu-repo/semantics/publishedVersio

    Exopolysaccharides produced by Lactobacillus and Bifidobacterium strains abrogate in vitro the cytotoxic effect of bacterial toxins on eukaryotic cells

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    Aims: To evaluate the capability of the exopolysaccharides (EPS) produced by lactobacilli and bifidobacteria from human and dairy origin to antagonize the cytotoxic effect of bacterial toxins. Methods and Results: The cytotoxicity of Bacillus cereus extracellular factors on Caco-2 colonocytes in the presence/absence of the EPS was determined by measuring the integrity of the tissue monolayer and the damage to the cell membrane (extracellular lactate dehydrogenase activity). Additionally, the protective effect of EPS against the haemolytic activity of the streptolysin-O was evaluated on rabbit erythrocytes. The EPS produced by Bifidobacterium animalis ssp. lactis A1 and IPLA-R1, Bifidobacterium longum NB667 and Lactobacillus rhamnosus GG were able to counteract the toxic effect of bacterial toxins on the eukaryotic cells at 1 mg ml-1 EPS concentration. The EPS A1 was the most effective in counteracting the effect of B. cereus toxins on colonocytes, even at lower doses (0.5 mg ml-1), whereas EPS NB667 elicited the highest haemolysis reduction on erythrocytes. Conclusions: The production of EPS by lactobacilli and bifidobacteria could antagonize the toxicity of bacterial pathogens, this effect being EPS and biological marker dependent. Significance and Impact of the Study: This work allows gaining insight about the mechanisms that probiotics could exert to improve the host health.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Criotecnología de Alimento

    Functional traits driving species role in the structure of terrestrial vertebrate scavenger networks

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    Species assemblages often have a non-random nested organization, which in vertebrate scavenger (carrion-consuming) assemblages is thought to be driven by facilitation in competitive environments. However, not all scavenger species play the same role in maintaining assemblage structure, as some species are obligate scavengers (i.e., vultures) and others are facultative, scavenging opportunistically. We used a database with 177 vertebrate scavenger species from 53 assemblages in 22 countries across five continents to identify which functional traits of scavenger species are key to maintaining the scavenging network structure. We used network analyses to relate ten traits hypothesized to affect assemblage structure with the “role” of each species in the scavenging assemblage in which it appeared. We characterized the role of a species in terms of both the proportion of monitored carcasses on which that species scavenged, or scavenging breadth (i.e., the species “normalized degree”), and the role of that species in the nested structure of the assemblage (i.e., the species “paired nested degree”), therefore identifying possible facilitative interactions among species. We found that species with high olfactory acuity, social foragers, and obligate scavengers had the widest scavenging breadth. We also found that social foragers had a large paired nested degree in scavenger assemblages, probably because their presence is easier to detect by other species to signal carcass occurrence. Our study highlights differences in the functional roles of scavenger species and can be used to identify key species for targeted conservation to maintain the ecological function of scavenger assemblages.Generalitat Valenciana SEJI/2018/024, APOSTD/2019/016, CIDEGENT/ 2020/030, ACIF/2019/056Ministerio de Educación y Cultura CI-2017-32149, FJCI-2015-25632, IJC2018-036642-I, YC-2019-027216-I, RYC-2015-19231, RYC-2017-2273, GL2012-40013-C02-01/02, CGL2015- 66966-C2-1-R, CGL2015-66966-C2-1-R2, CGL2017-89905-R, RTI2018-099609-B-C21, RTI2018-099609-B-C22Govern de les Illes Balears PD/039/201National Science Centre in Poland 2013/08/M/ NZ9/00469, 2016/22/Z/NZ8/00Slovenian Research Agency P4-0059US Department of Energy DE- EM000439USA National Science Foundation #1255913California Department of Fish & Wildlife P0880013Junta de Andalucía RNM-192

    Protein kinase B (AKT) upregulation and Thy-1-α<sub>v</sub>β<sub>3</sub> integrin-induced phosphorylation of Connexin43 by activated AKT in astrogliosis.

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    In response to brain injury or inflammation, astrocytes undergo hypertrophy, proliferate, and migrate to the damaged zone. These changes, collectively known as "astrogliosis", initially protect the brain; however, astrogliosis can also cause neuronal dysfunction. Additionally, these astrocytes undergo intracellular changes involving alterations in the expression and localization of many proteins, including α &lt;sub&gt;v&lt;/sub&gt; β &lt;sub&gt;3&lt;/sub&gt; integrin. Our previous reports indicate that Thy-1, a neuronal glycoprotein, binds to this integrin inducing Connexin43 (Cx43) hemichannel (HC) opening, ATP release, and astrocyte migration. Despite such insight, important links and molecular events leading to astrogliosis remain to be defined. Using bioinformatics approaches, we analyzed different Gene Expression Omnibus datasets to identify changes occurring in reactive astrocytes as compared to astrocytes from the normal mouse brain. In silico analysis was validated by both qRT-PCR and immunoblotting using reactive astrocyte cultures from the normal rat brain treated with TNF and from the brain of a hSOD1 &lt;sup&gt;G93A&lt;/sup&gt; transgenic mouse model. We evaluated the phosphorylation of Cx43 serine residue 373 (S373) by AKT and ATP release as a functional assay for HC opening. In vivo experiments were also performed with an AKT inhibitor (AKTi). The bioinformatics analysis revealed that genes of the PI3K/AKT signaling pathway were among the most significantly altered in reactive astrocytes. mRNA and protein levels of PI3K, AKT, as well as Cx43, were elevated in reactive astrocytes from normal rats and from hSOD1 &lt;sup&gt;G93A&lt;/sup&gt; transgenic mice, as compared to controls. In vitro, reactive astrocytes stimulated with Thy-1 responded by activating AKT, which phosphorylated S373Cx43. Increased pS373Cx43 augmented the release of ATP to the extracellular medium and AKTi inhibited these Thy-1-induced responses. Furthermore, in an in vivo model of inflammation (brain damage), AKTi decreased the levels of astrocyte reactivity markers and S373Cx43 phosphorylation. Here, we identify changes in the PI3K/AKT molecular signaling network and show how they participate in astrogliosis by regulating the HC protein Cx43. Moreover, because HC opening and ATP release are important in astrocyte reactivity, the phosphorylation of Cx43 by AKT and the associated increase in ATP release identify a potential therapeutic window of opportunity to limit the adverse effects of astrogliosis
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