64 research outputs found

    A numerical study of the Plata River plume along the southeastern South American continental shelf

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    O Rio da Prata, um dos maiores rios da Terra, descarrega no oceano águas de uma bacia de drenagem que cobre uma ampla área da América do Sul. Sua pluma extende-se ao longo do norte da Argentina, Uruguay e sul do Brasil influenciando amplamente os ecossistemas costeiros. A despeito disso, pouco se sabe a respeito dos mecanismos que a controlam. Relatamos aqui simulações conduzidas com o modelo POM na investigação do papel dos ventos e da descarga fluvial na dinâmica da pluma do Prata. Descargas com valores médios climatológicos e magnitudes representativas de El Niño e La Niña foram explorados. Somente sob descarga fluvial, a velocidade média de penetração da pluma ao longo da costa foi diretamente relacionada à vazão. Sua extensão variou entre 850 e 1550 km e no caso da vazão média uma banda de baixa salinidade formou-se desde o estuário até 30ºN na plataforma continental sul brasileira. O efeito de ventos de sudoeste, que causam subsidência, e de nordeste, que promovem a ressurgência costeira, foram investigados após 130 dias de descarga fluvial. Os resultados sugerem que a distribuição de baixa salinidade é muito mais sensível à direção dos ventos do que à descarga fluvial. Ventos de sudoeste são capazes de advectar o sinal de baixa salinidade ao longo da costa. Já os ventos de nordeste demonstram ser eficientes na erosão da pluma, que é destacada da costa por deriva de Ekman. Uma intrusão anormal da pluma de baixa salinidade em direção a baixas latitudes pode ser o resultado da posição original da pluma acoplada a eventos persistentes de fortes ventos de sudoeste.The Rio de la Plata, one of the largest rivers on Earth, discharges into the ocean waters from basin that covers a large area of South America. Its plume extends along northern Argentina, Uruguay, and southern Brazil shelves strongly influencing the ecosystems. In spite of this, little is known about the mechanisms that control it. Here we report results of simulations with POM carried out to investigate the roles of wind and river discharge in Plata plume dynamics. Different outflows were explored, including an average climatological value and magnitudes representative of La Niña and El Niño. Forcing the model with river discharge the average plume speed was directly related to the outflow intensity. The Plata northward extension varied from 850 to 1550 km and for average discharge a band of low salinity waters formed from the estuary up to 30ºN of South Brazilian Shelf. Upwelling and downwelling winds were applied after 130 days. The distribution of low salinity waters over the shelf was more sensitive to the wind direction than to the river outflow variability. Downwelling winds were very capable of advecting the low salinity signal downshelf. Upwelling winds were efficient in eroding the plume, which was basically detached from the coast by Ekman drift. Abnormal plume intrusions toward low latitudes may be a result of the original plume position coupled with events of persistent strong downwelling favorable winds

    Time Span does Matter for Offshore Wind Plant Allocation with Modern Portfolio Theory

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    Allocating wind farms across different locations may reduce the problematic intermittency of wind. The objective of this research was to analyze the optimal allocation of offshore wind farms in the U.S. East Coast through Modern Portfolio Theory (MPT). The research was conducted with 25.934 secondary observations of offshore wind energy produced by 11 hypothetical offshore wind farms. We calculated six minimum variance portfolios, each referring to a distinct time period. Four rebalancing strategies were settled in order to assess the performance of the portfolios we estimated. The results indicate that MPT can be used to calculate the diversification of offshore wind farms locations, which may reduce the individual variability of hourly wind power changes. Keywords: Modern Portfolio Theory; Optimal allocation; Offshore wind power JEL Classifications: C61, C53, L94, Q42, Q47.

    Benthic foraminiferal response to variations in temperature, salinity, dissolved oxygen and organic carbon, in the Guanabara Bay, Rio de Janeiro, Brazil

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    Recent benthic foraminiferal distribution patterns in Guanabara Bay are investigated in relation to temperature, salinity, dissolved oxygen and organic carbon content. Patterns of foraminiferal fauna differ between the entrance of the bay and inner parts. The primary result of the present study is that the distribution of Cassidulina subglobosa and Discorbis williamsoni appear to be governed by lower temperature and higher salinities being found in the entrance of the bay. According to dissolved oxygen content it was observed that Quinqueloculina seminulum occurs when values are higher than 2 mg/l, being intolerant to low oxygen bottom water conditions. By the other hand, Buliminella elegantissima, Bolivina striatula and Bulimmina elongata flourishes under low oxygen waters and in sediment where the organic matter accumulation is high, being found mainly in the central parts of the bay.Padrões de distribuição de foraminíferos bentônicos recentes são investigados com relação a temperatura, salinidade, oxigênio dissolvido e conteúdo de carbono orgânico. A distribuição de foraminíferos é diferente na entrada da baía se comparada às partes internas. Os primeiros resultados mostram que Cassidulina subglobosa e Discorbis williamsoni são encontradas em ambientes com baixa temperatura e altas salinidades na entrada da baía. De acordo com o teor de oxigênio dissolvido foi observado que Quinqueloculina seminulum ocorre quando os valores são mais altos que 2mg/l, sendo intolerante às condições. Por outro lado, Buliminella elegantissima, Bolivina striatula e Bulimmina elongata aparecem nas partes centrais da baía, que são locais com baixa oxigenação e sedimentos onde a acumulação de matéria orgânica é alta

    Lower lip squamous cell carcinoma in patients with photosensitive disorders : analysis of cases treated at the Brazilian National Cancer Institute (INCA) from 1999 to 2012

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    Lower lip squamous cell carcinoma (LLSCC) is a common malignancy of the head and neck, being mainly a consequence of a chronic exposure to ultraviolet (UV) light solar radiation. Here, we evaluated the clinicopathological profile of patients with photosensitive disorders (xeroderma pigmentosum, lupus erythematosus and albinism) that developed LLSCC. Data from patients who had a diagnosed LLSCC with a prior xeroderma pigmentosum, lupus erythematosus or albinism diagnosis that were treated at INCA from 1999 to 2012 were collected from patients? medical records (n=16). The control group was composed of 68 patients with LLSCC without a medical history of photosensitivity. The clinicopathological data of this study population were collected and the association between these variables was analyzed by Fisher?s exact test. Survival curves were constructed using the Kaplan?Meier method and compared by log-rank test. All statistical analyses were performed using SPSS statistics package. The mean age of patients in the photosensitive and non-photosensitive groups was 42 years and 67 years, respectively (p<0.0001). A previous history of malignant diseases was more common in the photosensitive group (p=0.001). In both groups, most tumors showed a pathological stage I/II disease. Overall and cancer-specific survival were not statistically different. However, disease-free interval showed a significant difference (p=0.01) between the photosensitive and non-photosensitive patients. Photosensitive patients presented LLSCC at earlier age but it usually was not the primary tumor in these patients. Furthermore, a more aggressive pathological behavior was not seen when compared with tumors from non-photosensitive patients. The disease-free interval was lower in photosensitive patients, as expected

    Anopheles darlingi polytene chromosomes: revised maps including newly described inversions and evidence for population structure in Manaus

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    Salivary gland polytene chromosomes of 4th instar Anopheles darlingi Root were examined from multiple locations in the Brazilian Amazon. Minor modifications were made to existing polytene photomaps. These included changes to the breakpoint positions of several previously described paracentric inversions and descriptions of four new paracentric inversions, two on the right arm of chromosome 3 and two on the left arm of chromosome 3 that were found in multiple locations. A total of 18 inversions on the X (n = 1) chromosome, chromosome 2 (n = 7) and 3 (n = 11) were scored for 83 individuals from Manaus, Macapá and Porto Velho municipalities. The frequency of 2Ra inversion karyotypes in Manaus shows significant deficiency of heterozygotes (p < 0.0009). No significant linkage disequilibrium was found between inversions on chromosome 2 and 3. We hypothesize that at least two sympatric subpopulations exist within the An. darlingi population at Manaus based on inversion frequencies

    Experimental Plasmodium vivax infection of key Anopheles species from the Brazilian Amazon

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    Made available in DSpace on 2015-09-21T17:25:38Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) jose_lima_etal_IOC_2013.pdf: 530553 bytes, checksum: ecc989c032bd9da39e398d263e88b3ae (MD5) Previous issue date: 2013Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, Brasil.Fundação de Medicina Tropical Dr. Heitor Vieira Dourado. Manaus, AM, Brasil / Universidade do Estado do Amazonas. Manaus, AM, Brasil.Instituto Nacional de Pesquisas da Amazônia, Manaus, AM, Brasil / Universidade do Estado do Amazonas. Manaus, AM, Brasil. / Ministerio da Saúde. Núcleo Amazonas. Fundação de Vigilância em Saúde. Manaus, AM, Brasil.Universidade Federal de Mato Grosso. Cuiabá, MT, Brasil.Instituto Nacional de Pesquisas da Amazônia. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil.Fundação de Medicina Tropical Dr. Heitor Vieira Dourado. Manaus, AM, Brasil / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.Fundação de Medicina Tropical Dr. Heitor Vieira Dourado. Manaus, AM, Brasil / Universidade do Estado do Amazonas. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, Brasil.Fundação de Medicina Tropical Dr. Heitor Vieira Dourado. Manaus, AM, Brasil / Universidade do Estado do Amazonas. Manaus, AM, Brasil.Instituto Nacional de Pesquisas da Amazônia. Manaus, AM, Brasil.Fundação de Medicina Tropical Dr. Heitor Vieira Dourado. Manaus, AM, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou; Belo Horizonte, MG, Brasil.Background: Anopheles darlingi is the major malaria vector in countries located in the Amazon region. Anopheles aquasalis and Anopheles albitarsis s.l. are also proven vectors in this region. Anopheles nuneztovari s.l. and Anopheles triannulatus s.l. were found infected with Plasmodium vivax; however, their status as vectors is not yet well defined. Knowledge of susceptibility of Amazon anopheline populations to Plasmodium infection is necessary to better understand their vector capacity. Laboratory colonization of An. darlingi, the main Amazon vector, has proven to be difficult and presently An. aquasalis is the only available autonomous colony. Methods: Larvae of An. darlingi, An. albitarsis s.l., An. nuneztovari s.l. and An. triannulatus s.l. were collected in the field and reared until adult stage. Adults of An. aquasalis were obtained from a well-established colony. Mosquitoes were blood-fed using a membrane-feeding device containing infected blood from malarial patients. The infection of the distinct Anopheles species was evaluated by the impact variance of the following parameters: (a) parasitaemia density; (b) blood serum inactivation of the infective bloodmeal; (c) influence of gametocyte number on infection rates and number of oocysts. The goal of this work was to compare the susceptibility to P. vivax of four field-collected Anopheles species with colonized An. aquasalis. Results: All Anopheles species tested were susceptible to P. vivax infection, nevertheless the proportion of infected mosquitoes and the infection intensity measured by oocyst number varied significantly among species. Inactivation of the blood serum prior to mosquito feeding increased infection rates in An. darlingi and An. triannulatus s.l., but was diminished in An. albitarsis s.l. and An. aquasalis. There was a positive correlation between gametocyte density and the infection rate in all tests (Z = −8.37; p < 0.001) but varied among the mosquito species. Anopheles albitarsis s.l., An. aquasalis and An. nuneztovari s.l. had higher infection rates than An. darlingi. Conclusion: All field-collected Anopheles species, as well as colonized An. aquasalis are susceptible to experimental P. vivax infections by membrane feeding assays. Anopheles darlingi, An. albitarsis s.l. and An. aquasalis are very susceptible to P. vivax infection. However, colonized An. aquasalis mosquitoes showed the higher infection intensity represented by infection rate and oocyst numbers. This study is the first to characterize experimental development of Plasmodium infections in Amazon Anopheles vectors and also to endorse that P. vivax infection of colonized An. aquasalis is a feasible laboratory model

    Omics profiles used to evaluate the gene expression of Exiguobacterium antarcticum B7 during cold adaptation

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    Abstract\ud \ud Background\ud \ud Exiguobacterium antarcticum strain B7 is a Gram-positive psychrotrophic bacterial species isolated in Antarctica. Although this bacteria has been poorly studied, its genome has already been sequenced. Therefore, it is an appropriate model for the study of thermal adaptation. In the present study, we analyzed the transcriptomes and proteomes of E. antarcticum B7 grown at 0°C and 37°C by SOLiD RNA-Seq, Ion Torrent RNA-Seq and two-dimensional difference gel electrophoresis tandem mass spectrometry (2D-DIGE-MS/MS).\ud \ud \ud Results\ud We found expression of 2,058 transcripts in all replicates from both platforms and differential expression of 564 genes (absolute log2FC ≥1, P-value <0.001) comparing the two temperatures by RNA-Seq. A total of 73 spots were differentially expressed between the two temperatures on 2D-DIGE, 25 of which were identified by MS/MS. Some proteins exhibited patterns of dispersion in the gel that are characteristic of post-translational modifications.\ud \ud \ud Conclusions\ud Our findings suggest that the two sequencing platforms yielded similar results and that different omic approaches may be used to improve the understanding of gene expression. To adapt to low temperatures, E. antarcticum B7 expresses four of the six cold-shock proteins present in its genome. The cold-shock proteins were the most abundant in the bacterial proteome at 0°C. Some of the differentially expressed genes are required to preserve transcription and translation, while others encode proteins that contribute to the maintenance of the intracellular environment and appropriate protein folding. The results denote the complexity intrinsic to the adaptation of psychrotrophic organisms to cold environments and are based on two omic approaches. They also unveil the lifestyle of a bacterial species isolated in Antarctica.CNPqCAPESUFPAFINEPFAPEMIGFundação para a Ciência e a Tecnologia de Portugal (FCT

    Global economic burden of unmet surgical need for appendicitis

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    Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US 92492millionusingapproach1and92 492 million using approach 1 and 73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was 95004millionusingapproach1and95 004 million using approach 1 and 75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

    Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

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    BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112
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