1,278 research outputs found

    Territory and climatic change : towards the construction of sustainable schemes of land use in Campeche, México

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    Fil: Ayala-Arcipreste, María Esther. Universidad Autónoma de CampecheFil: Isaac-Márquez, Ricardo. Universidad Autónoma de CampecheFil: Sánchez-González, María Consuelo. Universidad Autónoma de CampecheFil: Isaac-Márquez, Angélica Patricia. Universidad Autónoma de CampecheFil: Arteaga-Aguilar, Marco Antonio. Universidad Autónoma de Campech

    Managing of the 2006 present-day volcanic crisis at Ubinas

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    [ESP] Desde agosto de 2005, el volcán Ubinas (16º 22 'S, 70º 54' O; 5672 m snm) presentó un ligero aumento en su actividad fumarólica. En marzo de 2006, Ubinas comenzó a emitir esporádicamente cenizas finas y bloques balísticos de roca hidrotermal alterada. Los eventos están asociados con la actividad de tipo freático. Entre el 14 y el 20 de abril, el volcán Ubinas produjo continuamente cenizas en las ciudades de Querapi y Ubinas ubicadas a 4 y 6 km, respectivamente, al SE del volcán. Durante abril, la actividad de Ubinas fue variable, distinguida por las intensas emisiones de gases y la caída esporádica de cenizas. Debido a la ocurrencia de emisiones de cenizas registradas desde el 14 de abril, que causaron daños a las personas, el ganado y las tierras cultivadas, se formó el grupo de ciencia y tecnología de SIREDECI (Sistema Regional de Defensa Civil - Moquegua), integrado por instituciones geocientíficas que participan en la prevención y mitigación de desastres como: INGEMMET, IG-UNSA, IGP, IRD para realizar la evaluación de daños y la actividad sísmica del volcán, el monitoreo de deformaciones, el monitoreo geoquímico de aguas termales y la evaluación del peligro volcánico para prevenir y mitigar el efecto de un eventual volcán erupción que afecta a más de 5000 habitantes que viven en el valle de Ubinas. Este grupo evaluará los resultados obtenidos en el monitoreo volcánico para presentar una declaración oficial y una recomendación a SIREDECI y a las autoridades regionales y locales para efectuar trabajos de prevención y atenciones que dañen a las personas. El grupo geocientífico dará recomendaciones a SIDERECI como: evacuar a 40 familias de la ciudad de Querapi a la ciudad de Anascapa, ubicada a 8 km al sur de Ubinas. Durante los últimos fines de semana de abril, mucha gente de Ubinas y otras aldeas del valle se asustaron por la actividad volcánica y abandonaron sus viviendas. La mayoría de ellos se refugió en la ciudad de Arequipa, a 60 km del volcán. Además, SIREDECI durante la crisis atendió a la población dañada y actualmente viene trabajando con las instituciones geocientíficas en temas de evacuación y reubicación de las ciudades ubicadas en áreas de alto riesgo

    Natural transmission of dengue virus by aedes albopictus at Monterrey, Northeastern Mexico

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    Dengue cases occur frequently at Nuevo Leon, Mexico, where Aedes aegypti (L.) and Ae. albopictus (Skuse) are present. Ae. albopictus is considered the second vector of dengue. Because it bites humans outdoors during the day, the mosquito plays an important role in transmission of dengue virus (DENV). However, no previous studies at Nuevo Leon indicated the role of the mosquito outdoors. To assess Ae. albopictus for dengue virus, mosquitoes were collected from April to October 2010 at five localities at Guadalupe and Santiago, Nuevo Leon, (Northeast) Mexico, by using two methods: engine backpack aspirator and ovitraps. In total, 1,836 Ae. albopictus and 833 Ae. aegypti mosquitoes were collected by ovitrap and engine backpack aspirator methods. Groups of mosquitoes were processed by RT-PCR. Examination for DENV infection of mosquitoes showed one positive group of four female Ae. albopictus from an ovitrap. This research provided information that showed transovarial transmission of dengue virus in Ae. albopictus occurred naturally, maintaining endemic levels of disease at a study site

    In vitro evaluation of the antitumor effect of bismuth lipophilic nanoparticles (BisBAL NPs) on breast cancer cells

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    Aim: The objective of this study was to evaluate the antitumor activity of lipophilic bismuth nanoparticles (BisBAL NPs) on breast cancer cells. Materials and methods: The effect of varying concentrations of BisBAL NPs was evaluated on human MCF-7 breast cancer cells and on MCF-10A fibrocystic mammary epitheliocytes as noncancer control cells. Cell viability was evaluated with the MTT assay, plasma membrane integrity was analyzed with the calcein AM assay, genotoxicity with the comet assay, and apoptosis with the Annexin V/7-AAD assay. Results: BisBAL NPs were spherical in shape (average diameter, 28 nm) and agglomerated into dense electronic clusters. BisBAL NP induced a dose-dependent growth inhibition. Most importantly, growth inhibition was higher for MCF-7 cells than for MCF-10A cells. At 1 µM BisBAL NP, MCF-7 growth inhibition was 51%, while it was 11% for MCF-10A; at 25 µM BisBAL NP, the growth inhibition was 81% for MCF-7 and 24% for MCF-10A. With respect to mechanisms of action, a 24-hour exposure of 10 and 100 µM BisBAL NP caused loss of cell membrane integrity and fragmentation of tumor cell DNA. BisBAL NPs at 10 µM were genotoxic to and caused apoptosis of breast cancer cells. Conclusion: BisBAL NP-induced growth inhibition is dose dependent, and breast cancer cells are more vulnerable than noncancer breast cells. The mechanism of action of BisBAL NPs may include loss of plasma membrane integrity and a genotoxic effect on the genomic DNA of breast cancer cells. Keywords: antitumor activity, bismuth nanoparticles, breast cancer, chemotherapy, cytotoxicit

    Detection of dengue virus serotype 2 in aedes aegypti in Quintana Roo, Mexico, 2011

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    Abstract. In October 2011, the State Health Department announced that several laboratory-confirmed cases of dengue had occurred among residents in two neighborhoods of Benito Juarez, Quintana Roo State, Mexico. To identify the dengue virus serotype(s) temporally and spatially associated with the cases, entomologic-based virus surveillance was initiated in October 2011 in both neighborhoods. Adult mosquitoes were collected from 88 houses by CDCbackpack aspirator, and all female Aedes aegypti L. (n = 419) were individually homogenized and assayed in pools of as many as 10 by reverse transcriptionpolymerase chain reaction (RT-PCR) using dengue virus-specific primers. Five (12%) of 41 pools were positive for dengue virus RNA. The individual mosquitoes that comprised the pools were analyzed separately by RT-PCR using dengue virus serotype-specific primers. Six mosquitoes were positive for dengue virus serotype-2 (DENV-2) RNA, three of which were collected in the same house. The mean number of female Ae. aegypti collected in each house was 4.76 ± 6.19. The overall dengue virus-infection rate in female Ae. aegypti was 1.4%. Interestingly, most (60%) of mosquito females were collected only from 15 (17%) houses. In summary, we provide evidence of recent DENV-2 transmission in Quintana Roo State

    Seasonal diet composition of Pyrenean chamois is mainly shaped by primary production waves

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    In alpine habitats, the seasonally marked climatic conditions generate seasonal and spatial differences in forage availability for herbivores. Vegetation availability and quality during the growing season are known to drive life history traits of mountain ungulates. However, little effort has been made to understand the association between plant phenology and changes in the foraging strategies of these mountain dwellers. Furthermore, this link can be affected by the seasonal presence of livestock in the same meadows. The objective of this work was to study the seasonal changes in diet composition of Pyrenean chamois (Rupicapra p. pyrenaica) and its relationship to primary production trends in a Mediterranean alpine environment. Moreover, diet composition in two populations with contrasting livestock pressure was compared in order to study the effect of sheep flocks on the feeding behaviour of chamois. From 2009 to 2012, monthly diet composition was estimated by cuticle microhistological analysis of chamois faeces collected in the eastern Pyrenees. The primary production cycle was assessed by remote sensing, using the Normalized Difference Vegetation Index. Additionally, the diet of sheep sharing seasonally the subalpine and alpine meadows with chamois was analysed. Diet selection of chamois and sheep and their overlap was also assessed. Our results show an intra-annual variation in the diet composition of Pyrenean chamois and demonstrate a strong relationship between plant consumption dynamics and phenology in alpine areas. In addition, Calluna vulgaris, Cytisus spp. and Festuca spp., as well as forbs in the summer, are found to be key forage species for Pyrenean chamois. Furthermore, this study couldn't detect differences between both chamois populations despite the presence of sheep flocks in only one area. However, the detection of a shift in the diet of chamois in both areas after the arrival of high densities of multi-specific livestock suggest a general livestock effect. In conclusion, Pyrenean chamois are well adapted to the variations in the seasonal availability of plants in alpine habitats but could be disturbed by the seasonal presence of livestock. Due to the key plants in their diet, we suggest that population management programmes should focus on the preservation of mixed grasslands composed of patches of shrubs and herbs. The effects of climate change and shrub expansion should be studied as they may potentially affect chamois population dynamics through changes in habitat composition and temporal shifts in forage availability

    Effects of Albumin Treatment on Systemic and Portal Hemodynamics and Systemic Inflammation in Patients With Decompensated Cirrhosis

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    BACKGROUND & AIMS: We investigated the effect of albumin treatment (20% solution) on hypoalbuminemia, cardiocirculatory dysfunction, portal hypertension, and systemic inflammation in patients with decompensated cirrhosis with and without bacterial infections. METHODS: We performed a prospective study to assess the effects of long-term (12 weeks) treatment with low doses (1 g/kg body weight every 2 weeks) and high doses (1.5 g/kg every week) of albumin on serum albumin, plasma renin, cardiocirculatory function, portal pressure, and plasma levels of cytokines, collecting data from 18 patients without bacterial infections (the Pilot-PRECIOSA study). We also assessed the effect of short-term (1 week) treatment with antibiotics alone vs the combination of albumin plus antibiotics (1.5 g/kg on day 1 and 1 g/kg on day 3) on plasma levels of cytokines in biobanked samples from 78 patients with bacterial infections included in a randomized controlled trial (INFECIR-2 study). RESULTS: Circulatory dysfunction and systemic inflammation were extremely unstable in many patients included in the Pilot-PRECIOSA study; these patients had intense and reversible peaks in plasma levels of renin and interleukin 6. Long-term high-dose albumin, but not low-dose albumin, was associated with normalization of serum level of albumin, improved stability of the circulation and left ventricular function, and reduced plasma levels of cytokines (interleukin 6, granulocyte colony-stimulating factor, interleukin 1 receptor antagonist, and vascular endothelial growth factor) without significant changes in portal pressure. The immune-modulatory effects of albumin observed in the Pilot-PRECIOSA study were confirmed in the INFECIR-2 study. In this study, patients given albumin had significant reductions in plasma levels of cytokines. CONCLUSIONS: In an analysis of data from 2 trials (Pilot-PRECIOSA study and INFECIR-2 study), we found that albumin treatment reduced systemic inflammation and cardiocirculatory dysfunction in patients with decompensated cirrhosis. These effects might be responsible for the beneficial effects of albumin therapy on outcomes of patients with decompensated cirrhosis. ClinicalTrials.gov, Numbers: NCT00968695 and NCT03451292

    Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)

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    This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and Technology (CICYT), the Spanish National Parks agency, the European Commission, the Spanish Ministry of Science, and the European Social Fund

    Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)

    Get PDF
    This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and Technology (CICYT), the Spanish National Parks agency, the European Commission, the Spanish Ministry of Science, and the European Social Fund
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