28 research outputs found

    The incidence and clinical presentation of infantile rotavirus diarrhoea in Sierra Leone

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    Objectives. An effective vaccine is needed to protect against severe rotavirus disease, an important cause of gastroenteritis. Since there are no data on the incidence and antigenic diversity of rotavirus infection in Sierra Leone, we studied its epidemiology to enable an effective vaccine strategy to be designed.Methods. Children between the ages of 3 and 30 months presenting with gastroenteritis to the Ola During Children’s Hospital in Freetown, Sierra Leone, were enrolled. Stool specimens were tested in South Africa using polyacrylamide gel electrophoresis to confirm rotavirus infection.Results. Over a 5-month period 143 children presenting with gastroenteritis were recruited. Stool samples obtained from 128 study subjects were tested for the presence of rotavirus; 45% were aged between 3 and 9 months (mean age 10.85 months), and 48 stool samples (37.5%) tested positive for rotavirus. The incidence of rotavirus infection was 20% higher in boys than in girls, a gender difference confirmed elsewhere in West Africa. The prevalence of rotavirus-positive stools peaked in August, coinciding with the rainy season. About 90% of the rotavirus-positive patients had severe diarrhoea, as opposed to only about two-thirds of the patients whosediarrhoea  as not caused by rotavirus; this difference was statistically significant.Conclusions. There is a high incidence of rotavirus infection in Sierra Leone, with rotavirus causing 37.5% of the gastroenteritis in this study. Patients with rotavirus gastroenteritis almost all had severe diarrhoea. The high incidence of rotavirus infection and the severity of the diseasepresentation make the institution of a rotavirus vaccine programme in Sierra Leone imperative

    Comparing different models of the development of verb inflection in early child Spanish

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    How children acquire knowledge of verb inflection is a long-standing question in language acquisition research. In the present study, we test the predictions of some current constructivist and generativist accounts of the development of verb inflection by focusing on data from two Spanish-speaking children between the ages of 2;0 and 2;6. The constructivist claim that children's early knowledge of verb inflection is only partially productive is tested by comparing the average number of different inflections per verb in matched samples of child and adult speech. The generativist claim that children's early use of verb inflection is essentially error-free is tested by investigating the rate at which the children made subjectverb agreement errors in different parts of the present tense paradigm. Our results show: 1) that, although even adults ' use of verb inflection in Spanish tends to look somewhat lexically restricted, both children's use of verb inflection was significantly less flexible than that of their caregivers, and 2) that, although the rate at which the two children produced subjectverb agreement errors in their speech was very low, this overall error rate hid a consistent pattern of error in which error rates were substantially higher in low frequency than in high frequency contexts, and substantially higher for low frequency than for high frequency verbs. These results undermine the claim that children's use of verb inflection is fully productive from the earliest observable stages, and are consistent with the constructivist claim that knowledge of verb inflection develops only gradually

    Microstructural evolution in solution heat treatment of gas- atomised Al alloy (7075) powder for cold spray

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    Cold gas dynamic spray is being explored as a repair technique for high-value metallic components, given its potential to produce pore and oxide-free deposits of between several micrometers and several millimeters thick with good levels of adhesion and mechanical strength. However, feedstock powders for cold spray experience rapid solidification if manufactured by gas atomization and hence can exhibit non-equilibrium microstructures and localized segregation of alloying elements. Here, we used sealed quartz tube solution heat treatment of a precipitation hardenable 7075 aluminum alloy feedstock to yield a consistent and homogeneous powder phase composition and microstructure prior to cold spraying, aiming for a more controllable heat treatment response of the cold spray deposits. It was shown that the dendritic microstructure and solute segregation in the gas-atomized powders were altered, such that the heat-treated powder exhibits a homogeneous distribution of solute atoms. Micro-indentation testing revealed that the heat-treated powder exhibited a mean hardness decrease of nearly 25% compared to the as received powder. Deformation of the powder particles was enhanced by heat treatment, resulting in an improved coating with higher thickness (* 300 lm compared to * 40 um for untreated feedstock). Improved particle–substrate bonding was evidenced by formation of jets at the particle boundaries

    Development of the pelvis and posterior part of the vertebral column in the Anura

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    The anuran pelvic girdle is unique among all amphibians in that its acetabular portion is located far posterior to the sacrum, lateral to the postsacral (= caudal) vertebral column, which is reduced to a single rod-like element called the urostyle. This situation in the adult is strikingly different not only from that in ancestral temnospondyls but also in other modern amphibians. Because there is no fossil that would document this evolutionary anatomical modification except for Triadobatrachus, the only data may be inferred from development in modern anurans. We chose seven anuran species (belonging to the genera Discoglossus, Bombina, Pelobates, Bufo, Rana and Xenopus), representing the principal locomotory types (saltation, swimming, crawling and burrowing). Development of the pelvic girdle was studied on cleared and stained whole mounts and partly on serial histological sections. The basic developmental pattern was similar in all species: the pelvis on both sides develops from two centres (puboischiadic and iliac, respectively). The ilium then extends vertically towards the sacral vertebra and later rotates posteriorly so that ultimately the acetabulum is lateral to the tail (= urostyle). Only minor deviations from this pattern were found, mainly associated with differences in water and terrestrial dwelling

    Italy Towards Mandatory Sustainability Reporting. Voluntary Corporate Social Responsibility Disclosure of Italian companies and Legislative Decree 254/2016 statements. A Quantitative Analysis of the Last 10 Years

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    Corporate Social Responsibility Disclosure (CSRD) is crucial in providing transparent and reliable information. Company characteristics play a key role in CSRD, but legislation is important and positive in increasing the number of companies, which make complete, and transparent sustainability disclosure and stimulating CSR initiatives. In 2016, for the first time, Italian Legislative Decree 254/2016 requires ‘public interest entities’, to integrate statutory financial statements with disclosure of environmental, social and governance strategies from financial year 2017 onwards. This chapter investigates the role of company characteristics in influencing voluntary disclosure. The analysis focused on voluntary CSRD (2007–2016) implemented by Italian listed companies in the 10 year period, and shows that in a non-mandatory context the number of CSR reports published grew steadily. It reveals the voluntary behaviour of Italian companies, compliance with the requirements of the Decree with reference to the different dimensions of sustainability, and to the use of international standards and guidelines. Findings show also a marked increase of the number of companies, which, in 2017, produced a non-financial report after the entry into force of the new law. The strength of this work is that it investigates what happened in the decade preceding the introduction of the new law tracing the relationship between historical situation, business characteristics and the requirements of the legislative decree. These results and the immediate impact of the new regulation are interestingly linked to the relationship between law and sustainable development and will be directly and indirectly useful for scholars, managers and national and international regulators
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