Incidence and mechanisms of cerebral ischemia in early clinical head injury.

Antemortem demonstration of ischemia has proved elusive in head injury because regional CBF reductions may represent hypoperfusion appropriately coupled to hypometabolism. Fifteen patients underwent positron emission tomography within 24 hours of head injury to map cerebral blood flow (CBF), cerebral oxygen metabolism (CMRO2), and oxygen extraction fraction (OEF). We estimated the volume of ischemic brain (IBV) and used the standard deviation of the OEF distribution to estimate the efficiency of coupling between CBF and CMRO2. The IBV in patients was significantly higher than controls (67 +/- 69 vs. 2 +/- 3 mL; P < 0.01). The coexistence of relative ischemia and hyperemia in some patients implies mismatching of perfusion to oxygen use. Whereas the saturation of jugular bulb blood (SjO2) correlated with the IBV (r = 0.8, P < 0.01), SjO2 values of 50% were only achieved at an IBV of 170 +/- 63 mL (mean +/- 95% CI), which equates to 13 +/- 5% of the brain. Increases in IBV correlated with a poor Glasgow Outcome Score 6 months after injury (rho = -0.6, P < 0.05). These results suggest significant ischemia within the first day after head injury. The ischemic burden represented by this "traumatic penumbra" is poorly detected by bedside clinical monitors and has significant associations with outcome.

Bernstein, Dukheim e a sociologia da educação na Inglaterra

Neste texto o autor procura elucidar o modo pelo qual Basil Bernstein utilizou e enriqueceu a contribuição de Durkheim para a análise de questões abordadas pela sociologia da educação.

RTS,S/AS02A malaria vaccine does not induce parasite CSP T cell epitope selection and reduces multiplicity of infection

Objective: The candidate malaria vaccine RTS,S/AS02A is a recombinant protein containing part of the circumsporozoite protein (CSP) sequence of Plasmodium falciparum, linked to the hepatitis B surface antigen and formulated in the proprietary adjuvant system AS02A. In a recent trial conducted in children younger than age five in southern Mozambique, the vaccinedemonstrated significant and sustained efficacy against both infection and clinical disease. In a follow-up study to the main trial, breakthrough infections identified in the trial were examined to determine whether the distribution of csp sequences was affected by the vaccine and to measure the multiplicity of infecting parasite genotypes. Design: P. falciparum DNA from isolates collected during the trial was used for genotype studies. Setting: The main trial was carried out in the Manhiça district, Maputo province, Mozambique, between April 2003 and May 2004. Participants: Children from the two cohorts of the main trial provided parasite isolates as follows: children from Cohort 1 who were admitted to hospital with clinical malaria; children from Cohort 1 who were parasite-positive in a cross-sectional survey at study month 8.5; children from Cohort 2 identified as parasite-positive during follow-up by active detection of infection. Outcome: Divergence of DNA sequence encoding the CSP T cell-epitope region sequence from that of the vaccine sequence was measured in 521 isolates. The number of distinct P. falciparum genotypes was also determined. Results: We found no evidence that parasite genotypes from children in the RTS,S/AS02A arm were more divergent than those receiving control vaccines. For Cohort 1 (survey at studymonth 8.5) and Cohort 2, infections in the vaccine group contained significantly fewer genotypes than those in the control group, (p 1/4 0.035, p 1/4 0.006), respectively, for the two cohorts. This was not the case for children in Cohort 1 who were admitted to hospital (p 1/4 0.478). Conclusions: RTS,S/AS02A did not select for genotypes encoding divergent T cell epitopes in the C-terminal region of CSP in this trial. In both cohorts, there was a modest reduction in the mean number of parasite genotypes harboured by vaccinated children compared with controls, but only among those with asymptomatic infections.

Pieces of Iowa’s Past, February 8, 2012

Pieces of Iowa’s Past, published by the Iowa State Capitol Tour Guides weekly during the legislative session, features historical facts about Iowa, the Capitol, and the early workings of state government. All historical publications are reproduced here with the actual spelling, punctuation, and grammar retained. February 8, 2012 THIS WEEK: The Resolution Granting a Festival for the Citizens of Des Moines BACKGROUND: The following comes from a journal entry in the Pioneer Lawmakers’ Association of Iowa, Volumes 1-14, 1896-1913. The journal entry is from the Third Annual Meeting of the Pioneer Lawmakers— Reunion of 1892. The president, Charles Aldrich, called the meeting to order February 10, 1892, in the assembly rooms of the Young Men’s Christian Association. Governor Cyrus Carpenter gave the address. Cyrus Carpenter was born November 24, 1829, and died May 29, 1898. He served in the Seventh General Assembly in 1858. This was the first general assembly to meet in Des Moines in the newly constructed Brick Capitol. Carpenter was Iowa’s eighth governor since becoming a state in 1846. He was inaugurated in 1872 at the age of 42. Carpenter also served in the Iowa Senate during the 20th General Assembly in 1884

O poder cognitivo das redes neurais artificiais modelo ART1 na recuperação da informação

O artigo relata um experimento de simulação computacional de um sistema de recuperação da informação composto por uma base de índices textuais de uma amostra de documentos, um software de rede neural artificial implementando conceitos da Teoria da Ressonância Adaptativa, para automação do processo de ordenação e apresentação de resultados, e um usuário humano interagindo com o sistema em processos de consulta. O objetivo do experimento foi demonstrar (i) a utilidade das redes neurais de Carpenter e Grossberg (1988) baseadas nessa teoria e (ii) o poder de resolução semântica com índices sintagmáticos da abordagem SiRILiCO proposta por Gottschalg-Duque (2005), para o qual um sintagma nominal ou proposição é uma unidade linguística constituda de sentido maior que o significado de uma palavra e menor que uma narrativa ou uma teoria. O experimento demonstrou a eficácia e a eficiência de um sistema de recuperação da informação combinando esses recursos, concluindo-se que um ambiente computacional dessa natureza terá capacidade de clusterização (agrupamento) variável on-line com entradas e aprendizado contínuos no modo não supervisionado, sem necessidade de treinamento em modo batch (off-line), para responder a consultas de usuários em redes de computadores com desempenho promissor.

Paral lelismes lèxics en aragonès xistaví i català: préstec o fenomen de contínuum?

A part de l"ús del pretèrit perifràstic, format amb el verb ir + infinitiu (xistaví) o anar + infinitiu (català), els paral lelismes més interessants entre el xistaví i el català són de tipus lèxic. Tanmateix, sovint no resulta gens fàcil decidir si les formes compartides són préstecs directes o si constitueixen part d"un tresor comú. Determinades paraules com ara sep i boc, amb oclusiva final, i llesca, amb [ʎ] inicial, porten l"empremta d"identitat catalana, així com borde < bord, amb vocal de suport final en aragonès i en castellà, i cotón, sense l"article àrab aglutinat (però amb [n] final en aragonès). La forma mielsa és un catalanisme tan antic que presenta diftongació de la vocal radical en aragonès. A més a més, tancar, que és específic de l"Aragó oriental, sembla ser resultat de l"expansió del català a territoris dialectals veïns. En canvi, bachoca és tan generalitzat també es troba a Múrcia i València que no pot ésser considerat com el cas anterior. En aquest article intentem d"avaluar l"impacte del lèxic català en l"aragonès de Gistaín (xistaví).

Redução da influência da massa específica na determinação do teor de umidade de sementes de trigo

A medição da capacitância e da condutância de um capacitor contendo amostras de trigo permite a determinação de duas de suas propriedades dielétricas: a permissividade relativa (épsilon') e o fator de perda dielétrica (épsilon"). A utilização dessas propriedades, medidas simultaneamente em duas freqüências de oscilação do campo elétrico, permite reduzir ou eliminar o efeito da massa específica aparente na determinação do teor de umidade do trigo. Tal procedimento torna possível o monitoramento contínuo e em tempo real, sem a necessidade de retirar amostras, do teor de umidade de uma coluna de grãos em movimento, situação em que ocorrem as maiores variações na massa específica do produto. O objetivo deste trabalho consistiu na obtenção de equações que permitam reduzir ou eliminar o efeito da massa específica na determinação em linha do teor de umidade do trigo. Foram utilizadas amostras das variedades Hussar, Mercia e Hereward com teor de umidade entre 11% e 22% b.u. e massa específica no intervalo 666 kg m-3 <= ro <= 873 kg m-3. A equação que apresentou melhor desempenho permite calcular o teor de umidade do trigo com erros-padrão de calibração e de predição de 0,4 e 0,5 ponto percentual, respectivamente.

Carbon isotope discrimination and yield of upland rice as affected by drought at flowering

Field experiments involving upland rice genotypes, sown in various dates in late season, were carried out to assess the relationship of carbon isotope discrimination with grain yield and drought resistance. In each one of the three years, one trial was kept under good water availability, while other suffered water shortage for a period of 18-23 days, encompassing panicle emergence and flowering. Drought stress reduced carbon isotope discrimination measured on soluble sugars (deltas) extracted from stem uppermost internode at the end of the imposition period, but had relatively less effect on bulk dry matter of leaves, sampled at the same period, or that of uppermost internodes and grains, sampled at harvest. The drought-induced reduction in deltas was accompanied of reduced spikelet fertility and grain yield. In the three trials subjected to drought, genotypes with the highest yield and spikelet fertility had the lowest deltas. However, this relationship was weak and it was concluded that deltas is not a sufficiently reliable indicator of rice drought resistance to be useful as a screening test in breeding programs. On the other hand, grain yield and spikelet fertility of genotypes which were the soonest to reach 50% flowering within the drought imposition period, were the least adversely affected by drought. Then, timing of drought in relation to panicle emergence and to flowering appeared to be a more important cause of yield variation among genotypes than variation in deltas.

Postmodifying prepositional phrases in English and Spanish (with special reference to locative postmodifiers)

Prepositional phrases are the commonest kind of postmodification in all registers of English (Biber et al. 1999: 634). The locative ones that can be expanded into a defining relative clause (the books [which are] on the table) are usually expressed by such a construction in Spanish (los libros que están encima de la mesa) or by a phrase introduced by de (los libros de encima de la mesa). Wonder (1979) argues that Spanish allows locative phrases with prepositions other than de in the case of"situaciones"activas"" (el aterrizaje en pleno campo) as against"situaciones estáticas" (*el sofá en la sala), and if the phrase can be given an adverbial rather than, or in addition to, an adjectival interpretation (el ruido en la calle), especially if that phrase implies an alternative location for an object or contrast with another similar object (el sofá en la sala contigua). This paper further investigates this claim and looks at Spanish equivalents of English postmodifying prepositional phrases in general, while proposing an explanation for the choice of these different structures in Spanish based on considerations of lexical density. Resumen: Las frases preposicionales constituyen el tipo más frecuente de posmodificación en todos los registros del inglés (Biber et a. 1999: 634). En el español, las expresiones locativas suelen incorporar un pronombre relativo y un verbo (the books [which are] on the table > los libros que están encima de la mesa), o bien expresarse mediante una frase introducida por la preposición de (los libros de encima de la mesa). Wonder (1979) sostiene que el español permite el uso de preposiciones que no sean de en las frases locativas en el caso de"situaciones"activas"" (el aterrizaje en pleno campo) frente a"situaciones estáticas" (*el sofá en la sala), y también si la frase puede tener una función adverbial antes que, o además de, una interpretación adjetiva (el ruido en la calle), sobre todo si dicha frase encierra la idea de una posición alternativa para un objeto, o bien un contraste con otro objeto similar (el sofá en la sala contigua). El presente estudio pretende examinar este argumento y, además, explorar la posmodificación preposicional en español de un modo más general, a la par que propone una explicación sobre la elección de estructura en español que se basa en el criterio de la densidad léxica.