436 research outputs found

    Environmental tipping points for sperm motility, fertilization, and embryonic development in the crown-of-thorns starfish

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    For broadcast spawning invertebrates such as the crown-of-thorns starfish, early life history stages (from spawning to settlement) may be exposed to a wide range of environmental conditions, and could have a major bearing on reproductive success and population replenishment. Arrested development in response to multiple environmental stressors at the earliest stages can be used to define lower and upper limits for normal development. Here, we compared sperm swimming speeds and proportion of motile sperm and rates of fertilization and early development under a range of environmental variables (temperature: 20–36 oC, salinity: 20–34 psu, and pH: 7.4–8.2) to identify environmental tipping points and thresholds for reproductive success. We also tested the effects of water-soluble compounds, derived from eggs, on sperm activity. Our results demonstrate that gametes, fertilization, and embryonic development are robust to a wide range of temperature, salinity, and pH levels that are outside the range found at the geographical limits of adult distribution and can tolerate environmental conditions that exceed expected anomalies as a result of climate change. Water-soluble compounds derived from eggs also enhanced sperm activity, particularly in environmental conditions where sperm motility was initially limited. These findings suggest that fertilization and embryonic development of crown-of-thorns starfish are tolerant to a wide range of environmental conditions, though environmental constraints on recruitment success may occur at later ontogenic stages

    Thermodynamic properties of binary HCP solution phases from special quasirandom structures

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    Three different special quasirandom structures (SQS) of the substitutional hcp A1xBxA_{1-x}B_x binary random solutions (x=0.25x=0.25, 0.5, and 0.75) are presented. These structures are able to mimic the most important pair and multi-site correlation functions corresponding to perfectly random hcp solutions at those compositions. Due to the relatively small size of the generated structures, they can be used to calculate the properties of random hcp alloys via first-principles methods. The structures are relaxed in order to find their lowest energy configurations at each composition. In some cases, it was found that full relaxation resulted in complete loss of their parental symmetry as hcp so geometry optimizations in which no local relaxations are allowed were also performed. In general, the first-principles results for the seven binary systems (Cd-Mg, Mg-Zr, Al-Mg, Mo-Ru, Hf-Ti, Hf-Zr, and Ti-Zr) show good agreement with both formation enthalpy and lattice parameters measurements from experiments. It is concluded that the SQS's presented in this work can be widely used to study the behavior of random hcp solutions.Comment: 15 pages, 8 figure

    Exantema após vacinação do sarampo: análise laboratorial de casos notificados em São Paulo

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    OBJECTIVE: The clinical differential diagnosis of rash due to viral infections is often difficult, and misdiagnosis is not rare, especially after the introduction of measles and rubella vaccination. A study to determine the etiological diagnosis of exanthema was carried out in a group of children after measles vaccination. METHODS: Sera collected from children with rash who received measles vaccine were reported in 1999. They were analyzed for IgM antibodies against measles virus, rubella virus, human parvovirus B19 (HPV B19) using ELISA commercial techniques, and human herpes virus 6 (HHV 6) using immunofluorescence commercial technique. Viremia for each of those viruses was tested using a polimerase chain reaction (PCR). RESULTS: A total of 17 cases of children with exanthema after measles immunization were reported in 1999. The children, aged 9 to 12 months (median 10 months), had a blood sample taken for laboratory analysis. The time between vaccination and the first rash signs varied from 1 to 60 days. The serological results of those 17 children suspected of measles or rubella infection showed the following etiological diagnosis: 17.6% (3 in 17) HPV B19 infection; 76.5% (13 in 17) HHV 6 infection; 5.9% (1 in 17) rash due to measles vaccine. CONCLUSIONS: The study data indicate that infection due to HPV B19 or HHV 6 can be misdiagnosed as exanthema due to measles vaccination. Therefore, it is important to better characterize the etiology of rash in order to avoid attributing it incorrectly to measles vaccine.OBJETIVO: O diagnóstico diferencial de doenças exantemáticas causadas por vírus é geralmente difícil, e equívocos não são raros, especialmente depois da introdução da vacina contra o sarampo e a rubéola. Um estudo laboratorial foi conduzido com o objetivo de estabelecer o diagnóstico etiológico de casos de exantema em crianças que receberam a vacina contra o sarampo. MÉTODOS: Soros de casos de exantema em crianças que receberam vacina contra o sarampo, em 1999, foram analisados para anticorpos IgM contra os vírus do sarampo, da rubéola e do parvovírus humano B19 (HPV B19), por técnicas comerciais de Elisa, e o herpes vírus humano tipo 6 (HHV 6), por técnica comercial de imunofluorecência. A viremia para cada um desses vírus foi testada pela reação em cadeia da polimerase (PCR). RESULTADOS: Foram notificados, em 1999, 17 casos de crianças com exantema pós-vacinal. A idade das crianças era de nove a 12 meses (mediana, dez meses). Uma amostra de sangue colhida para investigação laboratorial foi obtida para cada criança. O tempo decorrido entre a aplicação da vacina e o aparecimento do exantema variou de um a 60 dias. Os resultados da sorologia das 17 crianças sugeriram o seguinte diagnóstico etiológico para o exantema: 17,6% (três em 17) infecção pelo HPV B19; 76,5% (13 em 17) infecção pelo HHV 6; 5,9% (um em 17) exantema originado pela vacina do sarampo. CONCLUSÃO: Os resultados indicaram que a infecção pelo HPV B19 ou pelo HHV 6 pode ser diagnosticada como sarampo de origem vacinal. Portanto, é fundamental incluir esses vírus no diagnóstico laboratorial para corretamente apontar a etiologia das doenças exantemáticas, evitando, assim, atribuir à vacina do sarampo efeito colateral

    Exposure to Family Planning Messages and Teenage Pregnancy: Results from the 2017 Philippine National Demographic and Health Survey

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    Background Teenage pregnancy is known to have physical, emotional, and psychosocial effects. Because of these risks, family planning and contraception messages have been disseminated in various forms of media, but their association with teenage pregnancy has not been studied previously in the Philippines. This study aims to examine the association between exposure to various family planning and contraception messages disseminated in various media channels and pregnancy among Filipino women aged 15–19. The study also intended to examine interactions between the different media channels where these family planning and contraception messages are being disseminated on their effect on teenage pregnancy. Methods We used data from the individual recode of the 2017 Philippine National Demographic and Health Survey. We used logistic regression for survey data to study the association between exposure to family planning and contraception messages and teenage pregnancy. Results Out of 5120 respondents, 44% of respondents have accessed information on contraception from the internet, 25% have heard information about contraception through the radio, 55% of respondents have heard about contraception via television, 15% have read about contraception in the newspapers and magazines, and only 6% have received information on contraception via short messaging service (SMS). There were 420 (8.56%) who have ever been pregnant. After adjusting for confounding variables, those who were exposed to family planning/contraceptive messages via the internet (aOR: 0.90; 95% CI: 0.59, 1.35) and newspapers/magazines (aOR: 0.78; 95% CI: 0.44, 1.41) have lower odds of teenage pregnancy, but no strong evidence of their effectiveness. On the other hand, exposure to family planning messages through the radio (aOR: 1.06; 95% CI: 0.71, 1.59), television (aOR: 1.09; 95% CI: 0.72, 1.65), and short messaging service (aOR: 1.29; 95% CI: 0.51, 3.22) marginally increase the risk of teenage pregnancy. We did not find any pairwise interactions between the different exposure variables. Conclusions Our results highlight the need to improve the content and key messages of contraceptive and family planning messages in the Philippines, especially those that are broadcasted online and in print media. There is also a need to increase the reach of these different family planning and contraception messages, especially by utilizing social media and other print and online media platforms commonly used by the youth

    Ultrahigh Surface Area Three-Dimensional Porous Graphitic Carbon from Conjugated Polymeric Molecular Framework

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    Porous graphitic carbon is essential for many applications such as energy storage devices, catalysts, and sorbents. However, current graphitic carbons are limited by low conductivity, low surface area, and ineffective pore structure. Here we report a scalable synthesis of porous graphitic carbons using a conjugated polymeric molecular framework as precursor. The multivalent cross-linker and rigid conjugated framework help to maintain micro- and mesoporous structures, while promoting graphitization during carbonization and chemical activation. The above unique design results in a class of highly graphitic carbons at temperature as low as 800 ??C with record-high surface area (4073 m2 g-1), large pore volume (2.26 cm-3), and hierarchical pore architecture. Such carbons simultaneously exhibit electrical conductivity >3 times more than activated carbons, very high electrochemical activity at high mass loading, and high stability, as demonstrated by supercapacitors and lithium-sulfur batteries with excellent performance. Moreover, the synthesis can be readily tuned to make a broad range of graphitic carbons with desired structures and compositions for many applications.clos

    QUALIDADE MICROBIOLÓGICA E FÍSICO-QUÍMICA DO LEITE PASTEURIZADO PRODUZIDO NA REGIÃO OESTE DO PARANÁ

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    O presente trabalho teve como objetivo avaliar a qualidade do leite pasteurizado produzido em Palotina - PR, comparando-se os resultados com os padrões da legislação nacional vigente, através de análises microbiológicas e físico-químicas. Foram coletadas aleatoriamente, 40 amostras de leites pasteurizados de diversos estabelecimentos comerciais de Palotina(PR). Deste total 16 amostras foram da marca X (08 tipo B e 08 desnatados, com inspeção estadual - SIP), 16 amostras da marca Y (08 tipo C e 08 desnatados com inspeção federal - SIF) e 08 amostras da marca Z (tipo C com inspeção federal - SIF). Após a coleta, as amostras foram enviadas imediatamente ao Laboratório de Controle Microbiológico de Água e Alimentos LACOMA, da UFPR Campus Palotina e estocadas em geladeira por um período máximo de 1 hora até o início das análises. Os resultados demonstraram que o produto estava dentro dos padrões aceitáveis para a contagem de mesófilos, psicrotróficos e coliformes fecais. Foi encontrado elevado percentual de amostras de leite peroxidase negativa (12 amostras 30%). Foi possível identificar 07 leites aguados, 05 suspeitos de aguagem, 01 com desnate parcial e 01 suspeito de desnate. Com os resultados obtidos pode-se concluir que as três marcas de leite comercializadas em Palotina apresentaram-se dentro dos padrões microbiológicos o que pode estar relacionado ao alto percentual de superaquecimento e que os resultados físico-químicos foram, de forma geral, insatisfatórios. Microbiological and physicalchemistry quality of pasteurized milks produced in the west region, Parana Abstract A survey has been carried out by means of microbiological and physical chemistry methods on the quality of pasteurized samples of milk from Palotina, Parana State, Brazil. Forty samples of pasteurized milks were gathered at several retail stores from Palotina. Sixteen samples labeled as X - 8 B and 8 skimmed milk, 16 samples labeled as Y - 8 C and 8 skimmed milk, and 8 samples labeled as Z - C milk, were analyzed at the Federal University of Paraná Laboratory for Water and Food Microbiological Control at Palotina Campus. After being stored at the refrigerator for one hour before the beginning of the analysis. According to the results found, all the milk samples analyzed were within the acceptable limits for mesophilic, psychrotroph and fecal coliform countings. An important data was the high percentage, as much as 30%, of negative peroxidase samples. In regard to the physical chemistry analysis carried out - fat, density at 15o C, total dry extract, unfat dry extract, cryoscopic index, phosphatase and peroxidase, the results were in general not satisfactories

    Growth anomalies on the coral genera Acropora and Porites are strongly associated with host density and human population size across the Indo-Pacific

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    Growth anomalies (GAs) are common, tumor-like diseases that can cause significant morbidity and decreased fecundity in the major Indo-Pacific reef-building coral genera, Acropora and Porites. GAs are unusually tractable for testing hypotheses about drivers of coral disease because of their pan-Pacific distributions, relatively high occurrence, and unambiguous ease of identification. We modeled multiple disease-environment associations that may underlie the prevalence of Acropora growth anomalies (AGA) (n = 304 surveys) and Porites growth anomalies (PGA) (n = 602 surveys) from across the Indo-Pacific. Nine predictor variables were modeled, including coral host abundance, human population size, and sea surface temperature and ultra-violet radiation anomalies. Prevalence of both AGAs and PGAs were strongly host density-dependent. PGAs additionally showed strong positive associations with human population size. Although this association has been widely posited, this is one of the first broad-scale studies unambiguously linking a coral disease with human population size. These results emphasize that individual coral diseases can show relatively distinct patterns of association with environmental predictors, even in similar diseases (growth anomalies) found on different host genera (Acropora vs. Porites). As human densities and environmental degradation increase globally, the prevalence of coral diseases like PGAs could increase accordingly, halted only perhaps by declines in host density below thresholds required for disease establishment

    Aspectos patológicos da intoxicação por aceturato de diminazeno em camelídeos sul-americanos.

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    Aceturato de diminazeno é um fármaco quimioterápico sintético comumente usado na medicina veterinária para o tratamento de doenças causadas por parasitos hematozoários. Entretanto, seu uso pode levar a efeitos colaterais, como alterações neurológicas graves e morte. A criação de camelídeos é uma atividade recente no Brasil, fazendo-se necessário conhecer mais sobre as doenças que acometem essas espécies. De dez camelídeos (seis lhamas e quatro alpacas) da propriedade, seis tiveram sinais clínicos e, destes, apenas uma lhama com manifestações leves recuperou-se. Os sinais clínicos incluíam apatia, andar cambaleante, fraqueza, sialorreia, cabeça baixa e pendida lateralmente, dificuldade em levantar e dispneia, observados a partir de 18 horas após o uso do medicamento. À necropsia e ao exame histopatológico foram observadas alterações de encefalopatia hemorrágica bilateral e simétrica, mais graves em tronco encefálico e tálamo. Este trabalho descreve as principais lesões observadas em um surto de intoxicação por diminazeno em alpacas (Lama pacos) e lhamas (Lama glama) e alerta criadores e veterinários sobre o risco de intoxicação por aceturato de diminazeno em camelídeos sulamericanos.Título em inglês: Pathological aspects of diminazene aceturate toxicosis in american camelids

    Biodegradable Mats for the Design of Bifunctional Biosensors for Glucose Detection in Urine.

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    Abstract: We introduce a bifunctional architecture to construct biosensors on solution-blow spinning fiber mats of polylactic acid (PLA) and polyethylene glycol (PEG). PLA/PEG mats acted as substrate for printing electrodes and as matrix to immobilize glucose oxidase (GOx). Prussian Blue nanoparticles (PB) decorated working electrodes to detect H2O2 from enzymatic catalysis at a low applied potential (0 V vs Ag/AgCl) with detection limit of 0.197 mM. The inexpensive bifunctional device (<US $0.25 per unit) exhibited a rapid response, long lifetime and performance similiar to the standard method for glucose monitoring in human urine samples. The PLA/PEG mats are sustainable alternative for biosensing and wearable applications
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