1,545 research outputs found

    Petrology, geochemistry and origin of the Sierra de Baza ophiolites (Betic Cordillera, Spain)

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    In this work we present for the first time a petrological-geochemical and genetic study of the Sierra de Baza ophiolites, which represent one of the ophiolitic occurrences of the Betic Cordillera (Southern Spain). They are composed of ultramafic, mafic and sedimentary rocks, largely affected both by ocean floor and polyphasic metamorphism during the Alpine orogeny. Ultramafic rocks are serpentinized lherzolites and harzburgites, whereas the metabasites are meta-gabbros and meta-basalts. On the whole, Sierra de Baza ophiolites show striking geochemical similarities with those from other Betic occurrences, as well as with other Tethyan ophiolites of the Western Mediterranean (Calabria, Internal and External Ligurides, Platta, Corsica and Western Alps). In particular, metabasites show petrological and geochemical features similar to the E-MORB magmatism of the Atlantic Ridge between 45 and 63ºN generated under ultra-slow spreading ridge conditions. This process originated a strip of few hundreds km of ocean floor at the western end of the Tethys, located SE of the Iberian-European margin during the Mesozoic. The inversion of the stress regime in the European-Iberian and African geodynamics, starting from the Late-Middle Cretaceous, caused subduction and metamorphism in the eclogite facies of oceanic slices that were partially exhumed on the continental margin, forming the Betic Ophiolites. These ophiolites were disarticulated and dismembered as a result of the shift towards SW of the Alboran continental block, progressively separated from the AlKaPeCa (Alboran, Kabilias, Peloritani, Calabria) microplate, finally occupying their current position in the Betic Internal Zones

    Analysis of Representativeness of the Paramo Ecosystem in the Conservation Modalities of the Chimborazo Province

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    The paramo ecosystem has ecological, social, cultural and economic importance due to the ecosystemic services of supply, regulation, support and culture that it provides to local populations for their well-being, therefore, it needs to be conserved and managed from an ecosystemic approach. The objective of this work is to analyze the conservation modalities that protect the paramo ecosystem in the Chimborazo province. To conduct the research, a systematic review of 30 cartographic sources was carried out, and documentary information on 7 variables of the paramo ecosystem was made, provided by institutions in charge of managing the province's natural resources, and found in articles consulted in scientific and academic databases. Additionally, gray literature has been included through manual search. The results indicate that the Chimborazo province has 17.93% of its extension under conservation modality, through 121 protected natural spaces, distributed in 3 modalities. The paramo ecosystem represents 36.40% of the province's size, and is made up of 9 vegetation formations. 15.10% of this ecosystem are under conservation modality, however, only 3 of the 121 spaces have planning documents for the management of these spaces. Keywords: paramo ecosystem, ecosystem services, conservation modalities. Resumen El ecosistema páramo tiene importancia ecológica, social, cultural y económica por los servicios ecosistémicos de abastecimiento, regulación, soporte y culturales que suministra a las poblaciones locales para su bienestar, por tanto, requiere ser conservado y manejado desde un enfoque ecosistémico. El objetivo de este trabajo es analizar las modalidades de conservación que protegen el ecosistema páramo en la provincia de Chimborazo. Para llevar a cabo la investigación se realizó una revisión sistémica de 30 fuentes de información cartográfica y documental sobre 7 variables del ecosistema páramo, facilitadas por instituciones encargadas del manejo de los recursos naturales de la provincia, y encontradas en artículos consultados en bases de datos científicas y académicas, adicionalmente se ha incluido literatura gris mediante la búsqueda manual. Los resultados indican que la provincia de Chimborazo tiene 17,93% de su extensión bajo modalidad de conservación, a través de 121 espacios naturales protegidos, distribuidos en 3 modalidades. El ecosistema páramo representa el 36,40% de la extensión de la provincia y está conformada por 9 formaciones vegetales. El 15,10% de éste ecosistema se encuentran bajo modalidad de conservación, sin embargo, únicamente 3 de los 121 espacios poseen documentos para el manejo de estos espacios. Palabras clave: ecosistema páramo, servicios ecosistémicos, modalidades de conservación

    Impact of pulmonary hypertension and congenital heart disease with hemodynamic repercussion on the severity of acute respiratory infections in children under 5 years of age at a pediatric referral center in Colombia, South America

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    Acute respiratory infection is one of the main causes of morbidity in children. Some studies have suggested that pulmonary hypertension and congenital heart disease with haemodynamic repercussion increase the severity of respiratory infections, but there are few publications in developing countries. Methods: This was a prospective cohort study evaluating the impact of pulmonary hypertension and congenital heart disease (CHD) with haemodynamic repercussion as predictors of severity in children under 5 years of age hospitalised for acute respiratory infection. Results: Altogether, 217 children hospitalised for a respiratory infection who underwent an echocardiogram were evaluated; 62 children were diagnosed with CHD with haemodynamic repercussion or pulmonary hypertension. Independent predictors of admission to intensive care included: pulmonary hypertension (RR 2.14; 95% CI 1.06–4.35, p = 0.034), respiratory syncytial virus (RR 2.52; 95% CI 1.29–4.92, p = 0.006), and bacterial pneumonia (RR 3.09; 95% CI 1.65–5.81, p = 0.000). A significant difference was found in average length of hospital stay in children with the cardiovascular conditions studied (p = 0.000). Conclusions: Pulmonary hypertension and CHD with haemodynamic repercussion as well as respiratory syncytial virus and bacterial pneumonia were predictors of severity in children with respiratory infections in this study. Early recognition of cardiovascular risks in paediatric populations is necessary to lessen the impact on respiratory infections

    A KK-monopole giant graviton in AdS_5 x Y_5

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    We construct a new giant graviton solution in AdS_5 x Y_5, with Y_5 a quasi-regular Sasaki-Einstein manifold, consisting on a Kaluza-Klein monopole wrapped around the Y_5 and with its Taub-NUT direction in AdS_5. We find that this configuration has minimal energy when put in the centre of AdS_5, where it behaves as a massless particle. When we take Y_5 to be S^5, we provide a microscopical description in terms of multiple gravitational waves expanding into the fuzzy S^5 defined as an S^1 bundle over the fuzzy CP^2. Finally we provide a possible field theory dual interpretation of the construction.Comment: 11 pages, published versio

    Association Between the Use of a Mobile Health Strategy App and Biological Changes in Breast Cancer Survivors: Prospective Pre-Post Study

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    The objectives of this study were to: (1) check whether it is feasible to find changes in inflammation biomarkers through an mHealth strategy app as a delivery mechanism of an intervention to monitor energy balance; and (2) discover potential predictors of change of these markers in breast cancer survivors (BCSs). Analyzing changes in inflammatory biomarker concentrations after using the mHealth app, differences between preassessment CRP (4899.04 pg/ml; SD 1085.25) and IL-6 (87.15 pg/ml; SD 33.59) and postassessment CRP (4221.24 pg/ml; SD 911.55) and IL-6 (60.53 pg/ml; SD 36.31) showed a significant decrease in both markers, with a mean difference of –635.25 pg/ml (95% CI –935.65 to –334.85; P<.001) in CRP and –26.61 pg/ml (95% CI –42.51 to –10.71; P=.002) in IL-6. Stepwise regression analyses revealed that changes in global quality of life, as well as uMARS score and hormonal therapy, were possible predictors of change in CRP concentration after using the mHealth app. In the same way, the type of tumor removal surgery conducted, as well as changes in weight and pain score, were possible predictors of change in IL-6 concentration after using the app. In conclusion, through the results of this study, we hypothesize that there is a possible association between an mHealth energy balance monitoring strategy and biological changes in BCSs. These changes could be explained by different biopsychosocial parameters, such as the use of the application itself, quality of life, pain, type of tumor removal surgery, hormonal treatment or obesity.The study was funded by the Spanish Ministry of Economy and Competitiveness (Plan Estatal de I+D+I 2013-2016), Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (PI14/01627), Fondos Estructurales de la Unión Europea (FEDER), and by the Spanish Ministry of Education (FPU14/01069 and FPU17/00939)

    Heart Rate Variability and Exceptional Longevity

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    Centenarians are the paradigm of human extreme longevity and healthy aging, because they have postponed, if not avoided, mayor age-related diseases. The purpose of this study was to investigate potential differences in resting heart rate variability (HRV) between young adults, octogenarians, and centenarians and assess whether HRV variables are predictors of all-cause mortality in centenarians. To this end, three groups of participants: young adults (N = 20; 20.6 ± 2.3 years), octogenarians (N = 18; 84.1 ± 2.6 years), and centenarians (N = 17; 101.9 ± 1.9 years) were monitored for 15 min at rest (seated, without moving or talking) to measure RR intervals, from which HRV was evaluated. Our results showed a clear decrease with age in the main parasympathetic HRV variables, as well as in the standard deviation (SD) of the RR series [SD of normal-to-normal interval (SDNN)] and in low frequency (LF) heart rate (HR) oscillations, although differences between octogenarians and centenarians did not reach statistical significance. In 14 centenarians followed until death, only SDNN showed significant correlation (¿ = 0.536; p = 0.048) with survival prognosis. Additionally, SDNN <19 ms was associated with early mortality (=1 year) in centenarians (Hazard Ratio = 5.72). In conclusion, HRV indices reflecting parasympathetic outflow as well as SDNN and LF all present an age-related reduction, which could be representative of a natural exhaustion of allostatic systems related to age. Moreover, low SDNN values (<19 ms) could be associated with early mortality in centenarians. HRV seems to play a role in exceptional longevity, which could be accounted for by centenarians’ exposome

    Cytological effects of pulsed electromagnetic fields and static magnetic fields induced by a therapeutic device on in vivo exposed rats

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    Background: There is a trend towards the use of magnetic fields in medicine. Pulsed electromagnetic fields (PEMFs) technology was based upon 20 years of fundamental studies on the electromechanical properties of bone and other connective tissues. More recently, these magnetic fields have been used to treat several health conditions. There remains continuing concern that exposure to electromagnetic devices may cause adverse effects. The aim of the present study was to investigate the cytological effects induced in rats exposed in a patented medical device that uses PEMFs combined with static magnetic fields (SMFs).Material and Methods: Thirty sexually mature 14-week-old male and female Sprague Dawley rats were distributed into three groups: (a) 5 males and 5 females (independently) exposed to PEMFs combined with SMFs, (b) animals treated with SMFs only, and (c) non-exposed animals. Acridine orange fluorescent-staining micronucleus test and male germ cells analysis were performed according to standardized techniques.Results: A lack of evidence for alterations on micronucleus frequency, on polychromatic erythrocytes percentage, and on sperm counts and morphological characteristics of male germ cells were found in mature rats exposed to PEMFs medical device compared to non-exposed animals.Conclusions: This study suggests that the applied magnetic field generated in a therapeutic device did not have any detectable cytotoxic or genotoxic effect in exposed rats. In view of these findings and the contradictory reports in the literature, it is necessary to carry out more research to help clarify the controversy concerning cytogenotoxic risk associated with therapeutic magnetic fields exposures.Keywords: Cytotoxicity, pulsed electromagnetic fields, static magnetic fields, micronuclei, sperm abnormalitie
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