914 research outputs found
Ecosystems are showing symptoms of resilience loss
Ecosystems around the world are at risk of critical transitions due to
increasing anthropogenic pressures and climate change. Yet, it is unclear where
the risks are higher or where in the world are ecosystems more vulnerable. Here
I measure resilience of primary productivity proxies for marine and terrestrial
ecosystems globally. Up to 29% of global terrestrial ecosystem, and 24% marine
ones, show symptoms of resilience loss. These symptoms are shown in all biomes,
but by large Arctic tundra and boreal forest are the most affected, as well as
the Indian Ocean and Easter Pacific. Despite the results are likely an
underestimation, they enable the identification of risk areas as well as the
potential synchrony of some transitions. Mapping where ecosystems are likely to
undergo critical transitions or long transients can help prioritize areas for
management interventions and conservation. These results pave the way towards
developing an ecological resilience observatory.Comment: 19 pages (including SM), 2 figures on main text, 10 SM figure
Growth aspects of the marine microalga Nannochloropsis gaditana
Nannochloropsis is well appreciated in aquaculture due to its nutritional value and the ability to produce valuable chemical compounds, such as pigments (zeaxanthin, astaxanthin...) and polyunsaturated fatty acids (EPA). Commercial exploitation needs high cell densities but the low growth rate and the small size of cells are practical difficulties. To increase biomass concentration the positive effect of several factors was evident: (i) pH[approximate]8 control (with dilute Tris-HCl buffer); (ii) the continuous illumination (no evidence of photo-inhibition was observed); (iii) a quite large temperature range (25±5 °C); (iv) the presence of organic carbon source (with the danger of contamination); (v) the presence of urea as an additional nitrogen source (10 mM); (vi) a small air flow rate with large bubbles can be more efficient for CO2 mass transfer (associated to reduced shearing).http://www.sciencedirect.com/science/article/B6VRM-492W13D-4/1/d65b11cf23c3d0795406c391c335446
Significance of interactions between microplastics and POPs in the marine environment: a critical overview
The presence of plastic debris in the ocean is increasing and several effects in the marine environment have been reported. A great number of studies have demonstrated that microplastics (MPs) adsorb organic compounds concentrating them several orders of magnitude than the levels found in their surrounding environment, therefore they could be potential vectors of these contaminants to biota. However, a consensus on MPs as vectors of persistent organic pollutants (POPs) has not been reached since are opposing views among different researchers on this topic. However, all agree that more extensive studies are needed to clarify this relationship. This review reunites information reporting the factors that drive the sorption dynamics between MPs and POPs, which essentially corresponds to polymer properties and surrounding environmental variables. Furthermore, this review highlights several supporting and rebuttal arguments in the direction to clear up the real hazard enforced by the presence of MPs in marine environments.publishe
Transcriptomic fingerprinting of Pseudomonas putida under alternative physiological regimes
Pseudomonas putida KT2440 is a metabolically versatile soil bacterium useful both as a model biodegradative organism and as a host of catalytic activities of biotechnological interest. In this report, we present the high-resolution transcriptome of P. putida cultured on different carbon sources as revealed by deep sequencing of the corresponding RNA pools. Examination of the data from growth on substrates that are processed through distinct pathways (glucose, fructose, succinate and glycerol) revealed that > 20% of the P. putida genome is differentially expressed depending on the ensuing physiological regime. Changes affected not only metabolic genes but also a suite of global regulators e.g. the rpoS sigma subunit of RNAP, various cold-shock proteins and the three HU histone-like proteins. Specifically, the genes encoding HU subunit variants hupA, hupB and hupN drastically altered their expression levels (and thus their ability to form heterodimeric combinations) under the diverse growth conditions. Furthermore, we found that two small RNAs, crcZ and crcY, known to inhibit the Crc protein that mediates catabolite repression in P. putida, were both down-regulated by glucose. The raw transcriptomic data generated in this work is made available to the community through the Gene Expression Omnibus database.This work was supported by the BIO and FEDER CONSOLIDER-INGENIO programs of the Spanish Ministry of Economy and Competitiveness, the MICROME, ST-FLOW and ARISYS Contracts of the EU, the ERANET Program and funding from the Autonomous Community of Madrid (PROMPT).Peer reviewe
Hospitalizações por infarto agudo do miocárdio segundo o dia da semana: estudo retrospectivo
INTRODUCTION: There is in the literature some studies looking for cycles and a circadian rhythm associated with acute myocardial infarction. Several authors have pointed out a higher incidence of myocardial infarction on Mondays suggesting the existence of trigger mechanisms in the disease onset. The week day distribution of hospitalizations due to myocardial infarction and its associations with patient sex and category of hospitalization (social status) in the Ribeirão Preto area from 1987 to 1996, were studied. METHODS: A total of 173,982 hospitalizations due to heart and cerebral vascular diseases, including 5,804 cases of acute myocardial infarction, were evaluated using the medical records of the Hospital Data Center of the medical school of Ribeirão Preto, University of S. Paulo. The hospitalizations were classified as being on a private basis, through private insurance or the Unified Health System (SUS). The associations with sex, patient condition at discharge and category of the hospitalization were studied. RESULTS/CONCLUSIONS: The distribution of hospitalizations due to heart and vascular diseases and acute myocardial infarction showed a peak incidence on Mondays, corresponding to 19.3% and 16.9% of the cases. During the weekend there was a decrease in the number of heart and vascular disease hospitalizations (8.6%) and a smaller reduction in the number of myocardial infarction cases (12.7%) which are statistically significant. In addition, there were observed differences in the distribution patterns according to the day of the week and category of hospitalization. While the SUS patients (4,120) and private insurance patients (1,225) are more likely to be hospitalized on Mondays, private patients (459) are more likely to be hospitalized on Fridays and Saturdays. There were no associations with patient sex and patient condition at discharge.OBJETIVO: A literatura tem relatado a associação do infarto com a segunda-feira, sugerindo a existência de mecanismos de "gatilho" no desencadeamento da doença. Foi realizado estudo para verificar a distribuição semanal das hospitalizações por infarto do miocárdio e sua associação ao sexo e à categoria da internação (condição social) na região de Ribeirão Preto de 1987 a 1996. MÉTODOS: Foram estudadas 173.982 hospitalizações por doenças cardíacas e vasculares cerebrais, incluindo 5.804 casos de infarto agudo do miocárdio, referidos a um centro de registro contínuo de informações de assistência hospitalar. As hospitalizações foram classificadas em particulares, de sistemas privados de pré-pagamento e do Sistema Único de Saúde (SUS). Foram estudadas as associações com o sexo, a condição do egresso e a categoria da internação. RESULTADOS/CONCLUSÕES: A distribuição semanal de hospitalizações por doenças cardiovasculares e infarto agudo do miocárdio apresentou um pico às segundas-feiras: 19,3% e 16,9% dos casos, respectivamente. Houve queda acentuada no final de semana (8,6%) dos casos de doenças cardiovasculares e menor redução dos casos de infarto agudo do miocárdio (12,7%), sendo essas diferenças estatisticamente significantes. Houve diferenças nos padrões de distribuição semanal dos pacientes do SUS (4.120), dos sistemas de pré-pagamento (1.225) e dos particulares (459). Para os pacientes do SUS e dos sistemas de pré-pagamento o número de hospitalizações foi elevado no início da semana e houve uma diminuição gradual no restante dos dias. Para os particulares, o número de hospitalizações foi baixa no domingo e houve elevação na sexta e sábado. Não houve associação com o sexo ou com a condição de saída
Critical Theory and the Loneliness of the Tax Prof
This essay, prepared for a symposium on critical theory and tax law, has two goals: to suggest why feminist theory and critical race theory are spreading in taxation and to discuss some dangers of that criticism. The author evaluates three examples of the new criticism: an article on critical race theory by Professors Moran and Whitford; an article on feminist statutory interpretation by Professor Handelman; and a book, Taxing Women, by Professor McCaffery
Toward understanding the dynamics of land change in Latin America : potential utility of a resilience approach for building archetypes of landsystems change
Rocha, Juan C. Stockholm University. Stockholm Resilience Centre. Stockholm, Suecia.Baraibar, Matilda M. Stockholm University. Department of Economic History and International Relations. Stockholm, Suecia.Deutsch, Lisa. Stockholm University. Stockholm Resilience Centre. Stockholm, Suecia.Bremond, Ariane de. University of Bern. Centre for Development and Environment. Bern, Suiza.Oestreicher, Jordan S. Universidade de Brasília. Centro de Desenvolvimento Sustentável. Distrito Federal, Brasil.Rositano, Florencia. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Cerealicultura. Buenos Aires, Argentina.Gelabert, Cecilia Corina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Economía, Desarrollo y Planeamiento Agrícola. Cátedra de Sistemas Agroalimentarios. Buenos Aires, Argentina.e17, 82 p.Climate change, financial shocks, and fluctuations in international trade are some of the reasons why resilience is increasingly invoked in discussions about land-use policy. However, resilience assessments come with the challenge of operationalization, upscaling their conclusions while considering the context-specific nature of land-use dynamics and the common lack of long-term data. We revisit the approach of system archetypes for identifying resilience surrogates and apply it to land-use systems using seven case studies spread across Latin America. The approach relies on expert knowledge and literature-based characterizations of key processes and patterns of land-use change synthesized in a data template. These narrative accounts are then used to guide development of causal networks, from which potential surrogates for resilience are identified. This initial test of the method shows that deforestation, international trade, technological improvements, and conservation initiatives are key drivers of land-use change, and that rural migration, leasing and land pricing, conflicts in property rights, and international spillovers are common causal pathways that underlie land-use transitions. Our study demonstrates how archetypes can help to differentiate what is generic from context dependant. They help identify common causal pathways and leverage points across cases to further elucidate how policies work and where, as well as what policy lessons might transfer across heterogeneous settings
Prospective, historically controlled study to evaluate the efficacy and safety of a new paediatric formulation of nifurtimox in children aged 0 to 17 years with chagas disease one year after treatment (Chico)
Nifurtimox is a recommended treatment for Chagas disease, but data from treated children are limited. We investigated the efficacy, safety and tolerability of nifurtimox administered as divisible, dispersible 30 mg and 120 mg tablets in children with Chagas disease. In this blinded, controlled study conducted January 2016–July 2018, 330 patients aged <18 years from 25 medical centres across three South American countries were randomised 2:1 to nifurtimox 10–20 mg/kg/day (aged <12 years) or 8–10 mg/kg/day (aged ≥12 years) for 60 days (n = 219), or for 30 days plus placebo for 30 days (n = 111) (ClinicalTrials.gov NCT02625974). The primary outcome was anti-Trypanosoma cruzi serological response (negative seroconversion or seroreduction ≥20% in mean optical density from baseline determined by two conventional enzyme-linked immunosorbent assays) at 12 months in the 60-day treatment group versus historical placebo controls. Nifurtimox for 60 days achieved negative seroconversion (n = 10) and seroreduction (n = 62) in 72 patients (serological response 32.9%; 95% confidence interval [CI] 26.4%, 39.3%, of all treated patients), confirming superiority relative to the upper 95% CI of 16% for controls. In patients aged <8 months, 10/12 treated for 60 days (83.3%) and 5/7 treated for 30 days (71.4%) achieved negative seroconversion. Overall serological response was lower for 30-day than for 60-day nifurtimox (between-treatment difference 14.0% [95% CI 3.7%, 24.2%]). The frequency of T. cruzi-positive quantitative polymerase chain reactions decreased substantially from baseline levels (60-day regimen 53.4% versus 1.4%; 30-day regimen 51.4% versus 4.5%). Study drug-related treatment-emergent adverse events (TEAEs), which were observed in 62 patients (28.3%) treated for 60 days and 29 patients (26.1%) treated for 30 days, were generally mild or moderate and resolved without sequelae; 4.2% of all TEAEs led to nifurti-mox discontinuation. Age-and weight-adjusted nifurtimox for 60 days achieved a serological response at 12 months post-treatment that was superior to historical placebo, was well tolerated and had a favourable safety profile in children with Chagas disease. Although, at 1 year serological follow-up, efficacy of the shorter nifurtimox treatment was not comparable to the 60-day treatment regimen for the overall study population, further long-term follow-up of the patients will provide important information about the progress of serological conversion in children treated with nifurtimox, as well as the potential efficacy difference between the two regimens over time.Fil: Altcheh, Jaime Marcelo. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; ArgentinaFil: Castro, Luis. Centro de Atención E Investigación Médica; ColombiaFil: Dib, Juan C.. Universidad del Norte; ColombiaFil: Grossmann, Ulrike. No especifíca;Fil: Huang, Erya. No especifíca;Fil: Moscatelli, Guillermo. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; ArgentinaFil: Pinto Rocha, Jimy José. Fundación Ceades; BoliviaFil: Ramírez, Teresa Estela. Centro de Enfermedad de Chagas y Patologias Regionales; Argentin
Prevalencia de microfilariasis en la población humana de Iquitos y zonas peri urbanas, Loreto, Perú
Los estudios de filariasis podrían ayudarnos a identificar casos febriles de etiología desconocida en los establecimientos de Salud. Se realizó un estudio epidemiológico, descriptivo, observacional, transversal y prospectivo; determinando la prevalencia de microfilariasis, relacionándola con las características epidemiológicas como sexo, edad y fiebre. Se procesaron 755 muestras. La microfilariasis fue detectada mediante microscopia simple, la prueba de Knott y Gota Gruesa fueron modificados por los autores. Se determinó una prevalencia de 6,2 %, encontrándose Mansonella ozzardi (2,0%) y una especie atípica, designada como Microfilaria sp. (4,1%); y la confección por ambas especies (0,1%). Las personas infectadas por Microfilaria sp., desarrollaban actividades en zona urbana; encontrándose una frecuencia alta en mujeres de 4 a 12 años, procedentes de los distritos de San Juan, Iquitos y Punchana. Las infecciones por M. ozzardi fueron frecuentes en pacientes febriles del género masculino, de 22 a 39 años, procedentes del distrito de Belén, cuya actividad principal se desarrolla mayormente en el campo. Se encontró pobladores infectados con microfilarias en la ciudad de Iquitos y zonas peri urbanas; resultados que justifican investigaciones para determinar si el parásito Microfilaria sp., está causando síndromes clínicos y definir los ciclos de transmisión
Preliminary research of petrographic, petrophysical and mechanical behavior of natural stones as “Piedra Bogotana” and “Marmol Royal Bronce” used in heritage buildings and new constructions in Colombia
La piedra natural ha sido un elemento importante en la construcción colombiana desde la época colonial y hasta la actualidad, especialmente en la ciudad de Bogotá. Rocas areniscas y calizas son elementos decorativos y estructurales de edificaciones patrimoniales y recientes y su uso gana notoriedad con la recuperación de espacios urbanos para el disfrute de la población. En este trabajo se muestran los resultados de algunos ensayos de caracterización tecnológica de dos variedades de rocas ampliamente utilizadas en la construcción, conocidas coloquialmente con los nombres de Piedra Muñeca o Piedra Bogotana y Mármol Royal Bronce, utilizadas tanto en edificaciones patrimoniales como recientes. Los métodos de ensayo seguidos para evaluar algunas de las propiedades petrofísicas y mecánicas de estas dos rocas fueron: Análisis petrográfico, índices físicos (densidad aparente, porosidad aparente y absorción de agua), resistencia a la compresión, resistencia a la flexión, resistencia al desgaste y resistencia al impacto, expuestos en la norma brasileña ABNT NBR15845 de 2010. Los resultados obtenidos permiten determinar, de forma preliminar, que la Piedra bogotana en sus dos variedades (amarilla y rosada) puede ser usada como elemento estructural (muros, columnas, vigas y cimentaciones) y como material de revestimiento de edificios o de pisos y plazoletas, con la recomendación de uso de la variedad amarilla preferiblemente en espacios interiores; el Mármol Royal Bronce puede ser usado en cualquier tipo de revestimiento de paredes, pisos y calles de alto tráfico, como elemento estructural y en acabados.Natural stone has been an important element in Colombian construction since the hispanic period, especially in Bogotá city capital from Colombia. Sandstone and limestone rocks are ornamental and structural elements on heritage buildings and new constructions, and their use is important to revitalization of urban spaces for the enjoyment of the population. This paper shows the results of some technological characterization tests of two rock types widely used in construction, commonly known as Piedra Muñeca or Piedra Bogotana and Marmol Royal Bronce, used in historical buildings as well as modern ones. Petrophysical and mechanical properties of these rocks identified in a preliminary way were: Petrographic analysis, physical properties (bulk density, bulk porosity and water absorption), compressive strength, flexural strength, weathering resistance and impact resistance, as shown in the Brazilian technical standard ABNT NBR15845. The obtained results allows to determine, in an early way, that the two varieties (yellow and pink) of the Piedra bogotana stone can be used as a structural element (walls, columns, beams and foundations) and also as a dimension stone for buildings, floors and squares. It´s recommended the use of yellow variety specially on interior spaces. Marmol Royal Bronce can be used in finishes and also in any type of facing, floor and as a structural element in highly traffic streets
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