On the interaction of the anthraquinone barbaloin with negatively charged DMPG bilayers

Barbaloin is a bioactive glycosilated 1,8-dihydroxyanthraquinone present in several exudates from plants, Such as Aloe vera, which are used for cosmetic or food purposes. It has been shown that barbaloin interacts with DMPG (dimyristoylphosphatidylglycerol) model membranes, altering the bilayer structure (Alves, D. S.; Perez-Fons, L.; Estepa, A.; Micol, V. Biochem. Pharm. 2004, 68, 549). Considering that ESR (electron spin resonance) of spin labels is one of the best techniques to monitor structural properties at the molecular level, the alterations caused by the anthraquinone barbaloin on phospholipid bilayers will be discussed here via the ESR signal of phospholipid spin probes intercalated into the membranes. In DMPG at high ionic strength (10 mM Hepes pH 7.4 + 100 mM NaCl), a system that presents a gel-fluid transition around 23 degrees C, 20 mol % barbaloin turns the gel phase more rigid, does not alter much the fluid phase packing, but makes the lipid thermal transition less sharp. However, in a low-salt DMPG dispersion (10 mM Hepes pH 7.4 + 2 mM NaCl), which presents a rather complex gel-fluid thermal transition (Lamy-Freund, M. T.; Riske, K. A. Chem. Phys. Lipids 2003, 122, 19), barbaloin strongly affects bilayer structural properties, both in the gel and fluid phases, extending the transition region to much higher temperature values. The position of barbaloin in DMPG bilayers will be discussed on the basis of ESR results, in parallel with data from sample viscosity, DSC (differential scanning calorimetry), and SAXS (small-angle X-ray scattering).

Polymorphisms in genes involved in neurodevelopment may be associated with altered brain morphology in schizophrenia: Preliminary evidence

An abnormality in neurodevelopment is one of the most robust etiologic hypotheses in schizophrenia (SZ). There is also strong evidence that genetic factors may influence abnormal neurodevelopment in the disease. The present study evaluated in SZ patients, whose brain structural data had been obtained with magnetic resonance imaging (MRI), the possible association between structural brain measures, and 32 DNA polymorphisms,located in 30 genes related to neurogenesis and brain development. DNA was extracted from peripheral blood cells of 25 patients with schizophrenia, genotyping was performed using diverse procedures, and putative associations were evaluated by standard statistical methods (using the software Statistical Package for Social Sciences - SPSS) with a modified Bonferroni adjustment. For reelin (RELN), a protease that guides neurons in the developing brain and underlies neurotransmission and synaptic plasticity in adults, an association was found for a non-synonymous polymorphism (Va1997Leu) with left and right ventricular enlargement. A putative association was also found between protocadherin 12 (PCDH12), a cell adhesion molecule involved in axonal guidance and synaptic specificity, and cortical folding (asymmetry coefficient of gyrification index). Although our results are preliminary, due to the small number of individuals analyzed, such an approach could reveal new candidate genes implicated in anomalous neurodevelopment in schizophrenia. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

Language and Identity at School and at Home : Language Shift among Mennonites in Paraguay

This essay has investigated the question of an ongoing language shift from Plattdeutsch and German to Spanish among the Mennonites in Paraguay and the role of the school in this process. The aims of the study were to compare the use of languages among the Mennonites in Asuncion and in the Menno colony and to identify the importance that parents give to the languages and to compare this with a school leader perspective. The aim was also to identify factors that influence the language shift and identify the influence that the shift excerpts on Mennonite values and identity. The results are based on my own observations, interviews with Mennonite women and interviews with key informants who have insight into the school policy issues. The outcome may be used as a basis for educational and language planning. There is a need to consciously sit down and re-define the Mennonite identity and to make the community and the school aware of their responsibility in language maintenance.

Literacy Practices in and out of School in Karagwe : The case of primary school literacy education in rural Tanzania

This study has investigated the question of relation between literacy practices in and out of school in rural Tanzania. By using the perspective of linguistic anthropology, literacy practices in five villages in Karagwe district in the northwest of Tanzania have been analysed. The outcome may be used as a basis for educational planning and literacy programs. The analysis has revealed an intimate relation between language, literacy and power. In Karagwe, traditional élites have drawn on literacy to construct and reconstruct their authority, while new élites, such as individual women and some young people have been able to use literacy as one tool to get access to power. The study has also revealed a high level of bilingualism and a high emphasis on education in the area, which prove a potential for future education in the area. At the same time discontinuity in language use, mainly caused by stigmatisation of what is perceived as local and traditional, such as the mother-tongue of the majority of the children, and the high status accrued to all that is perceived as Western, has turned out to constitute a great obstacle for pupils’ learning. The use of ethnographic perspectives has enabled comparisons between interactional patterns in schools and outside school. This has revealed communicative patterns in school that hinder pupils’ learning, while the same patterns in other discourses reinforce learning. By using ethnography, relations between explicit and implicit language ideologies and their impact in educational contexts may be revealed. This knowledge may then be used to make educational plans and literacy programmes more relevant and efficient, not only in poor post-colonial settings such as Tanzania, but also elsewhere, such as in Western settings.

O migrante na escola: um estudo de caso

O trabalho se propoe a retratar a realidade da criança migrante na região de destino, mais especificamente no contexto escolar. Tomando por base observações realizadas numa escola do Municipio de Nova Iguaçu, são sugeridas modificações nos curriculos plenos com vistas a um melhor atendimento ao aluno migrante, enquanto sujeito ao processo educativo formal . A criança que migra para a Baixada Fluminense, geralmente, detem um código restrito e depara-se, na escola, com outro semelhante ao seu, utilizado pelo aluno não migrante e com um código elaborado veiculado por aquela instituiçao. Embora se considere o código linguistico um obstáculo de difícil transposição, ao fim de algum tempo, o aluno migrante consegue "imitar" o dos colegas que, tal como ele, integram a população de baixa renda. Já o código difundido pela escola é de dificil absorção pelos seus alunos que nao vivenciam experiências e condutas das classes dominantes que ele procura expressar e caracterizar. No processo de ajustamento e acomodação da criança à sociedade de classes, cabe ao curriculo escolar estabelecer relações de poder e controle expressas nos principios de classificação e emolduramento. A fim de propiciar uma educação voltada para a mudança, os curriculos plenos, muito embora desempenham um papel secundário, devem ser organizados com a participação de representantes de diferentes segmentos da escola buscando preservar valores e traços culturais distintos e estruturados a partir de uma reflexão sobre a realidade.

Spawning failure in Brycon amazonicus may be associated with ovulation and not with final oocyte maturation

Avaliaram-se os possíveis mecanismos envolvidos com a falha na desova de matrinxãs (Brycon amazonicus), submetidas à indução hormonal por extrato bruto de hipófise de carpa. Para tal, após a extrusão, os ovários foram coletados e analisados histomorfometricamente. Nas fêmeas que não desovaram (FNDs), a maioria dos ovócitos vitelogênicos remanescentes nos ovários atingiu a maturação final, apresentando quebra de vesícula germinativa, mas não foram ovulados (NOs). Consequentemente, estas fêmeas apresentaram frequências mais baixas de folículos pós ovulatórios (5%) quando comparadas com a que desovou (FD) (23%). Com relação aos NOs, os valores se inverteram e a frequência destes nas FNDs (21%) foi maior do que na FD (3%). Estes dados indicam que as falhas na desova desta espécie estão provavelmente relacionadas com a ovulação, uma vez que a maturação final dos ovócitos ocorre de forma similar tanto nas FNDs como na FD. Os dados sugerem que as substâncias que promovem a ovulação, como as prostaglandinas, podem aumentar o sucesso de desova em peixes reofílicos.

Increasing Moodle Resources Through Cloud Computing

The increase of higher education offer is a basic need of developed and emerging countries. It requires increasing and ongoing investments. The offer of higher education, by means of Distance Learning, based on the Internet, is one of the most efficient manners for the massification of this offer, as it allows ample coverage and lower costs. In this scenario, we highlight Moodle, an open and low-cost environment for Distance Learning. Its utilization may be amplified through the adoption of an emerging Information and Communication Technology (ICT), Cloud Computing, which allows the virtualization of Moodle sites, cutting costs, facilitating management and increasing its service capacity. This article diffuses a public tool, opened and free, for automatic conversion of Moodle sites, such that these may be hosted on Azure: the Cloud Computing environment of Microsoft.

Performance of aerodynamic baffles in cylindrical grinding analyzed on the basis of air layer pressure and speed

Over the years, grinding has been considered one of the most important manufacturing processes. Grinding is a high precision process, and the loss of a single workpiece in this stage of the production is unacceptable, fir the value added to the material is very high due to many processes it has already undergone prior to grinding. This study aims to contribute toward the development of an experimental methodology whereby the pressure and speed of the air layer produced by the high rotation of the grinding wheel is evaluated with and without baffles, i.e., in an optimized grinding operation and in a traditional one. Tests were also carried out with steel samples to check the difference in grinding wheel wear with and without the use of baffles.

Effects of prolonged running performed at the intensity corresponding to the onset of blood lactate accumulation, on maximum isokinetic strength in active non-athletic individuals

OBJETIVO: O objetivo deste estudo foi analisar os efeitos da corrida contínua prolongada realizada na intensidade correspondente ao início do acúmulo do lactato no sangue (OBLA) sobre o torque máximo dos extensores do joelho analisado em diferentes tipos de contração e velocidade de movimento em indivíduos ativos. MÉTODO: Oito indivíduos do gênero masculino (23,4 ± 2,1 anos; 75,8 ± 8,7 kg; 171,1 ± 4,5 cm) participaram deste estudo. Primeiramente, os sujeitos realizaram um teste incremental até a exaustão voluntária para determinar a velocidade correspondente ao OBLA. Posteriormente, os sujeitos retornaram ao laboratório em duas ocasiões, separadas por pelo menos sete dias, para realizar 5 contrações isocinéticas máximas para os extensores do joelho em duas velocidades angulares (60 e 180º.s-1) sob as condições excêntrica (PTE) e concêntrica (PTC). Uma sessão foi realizada após um período de aquecimento padronizado (5 min a 50%VO2max). A outra sessão foi realizada após uma corrida contínua no OBLA até a exaustão voluntária. Essas sessões foram executadas em ordem randômica. RESULTADOS: Houve redução significante do PTC somente a 60º.s-1 (259,0 ± 46,4 e 244,0 ± 41,4 N.m). Entretanto, a redução do PTE foi significante a 60º.s-1 (337,3 ± 43,2 e 321,7 ± 60,0 N.m) e 180º.s-1 (346,1 ± 38,0 e 319,7 ± 43,6 N.m). As reduções relativas da força após o exercício de corrida foram significantemente diferentes entre os tipos de contração somente a 180º.s-1. CONCLUSÃO: Podemos concluir que, em indivíduos ativos, a redução no torque máximo após uma corrida contínua prolongada no OBLA pode ser dependente do tipo de contração e da velocidade angular.

HETEROCHROMATIN AND KARYOTYPE REORGANIZATION IN FISH OF THE FAMILY ANOSTOMIDAE (CHARACIFORMES)

Mitotic chromosomes of four fish species of the family Anostomidae, belonging to the genera Leporinus, Leporellus, and Schizodon, were studied. With 2n = 54 meta- and submetacentric chromosomes, this family appears to be characterized by marked karyotypic stability. Although perceptible differences exist, mainly in the amount of constitutive heterochromatin present in the chromosomes of these species, these differences do not affect the structure and/or size of these chromosomes. Chromatin substitutions and/or modifications may have led, in one direction, to an increase in heterochromatin in some species and, in the opposite direction, to heterochromatin reduction in others. Whether these changes are accompanied by changes in the amount of euchromatin in the chromosomes is an open question. The nucleolar organizer regions, which may be located on different chromosomes in the various species, may also be indicators of reorganization of these karyotypes.

Labeling index in pituitary adenomas evaluated by means of MIB-1: is there a prognostic role? A critical review

Objective: The present article presents an overview of the literature, and analyses the methods and the primary questions related to assessment of proliferation index using the Ki-67/MIB-1 labeling index in pituitary adenomas. Although atypical adenomas are characterized by their atypical morphological features by an elevated mitotic index, a Ki-67 (MIB-1) labeling index greater than 3% and extensive nuclear staining for p53, use of the proliferation index (LI) of pituitary adenomas in assessing the degree of tumor aggressiveness is a controversial topic in the literature, and there are disparate results involving many studies.Methods: A review of literature was carried out to correlate the role of Ki-67 LI and its correlation with clinical findings, tumor size, invasiveness, recurrence, adenoma subtype, adenoma doubling time, and pituitary carcinomas is addressed. Results: The prognosis cannot be predicted on the basis of the Ki-67 LI alone. Although there is no direct relation between Ki-67 LI and some of these variables and controversial data were found regarding some topics, our review justify the use of Ki-67 in the analysis of pituitary adenomas as an additional information for clinical decision.Conclusion: Although assessment of proliferative may be helpful in predicting subsequent tumor recurrence or invasiveness, there are many other important and as yet unidentified factors pituitary tumors. It is clear that further research is needed to clarify these molecular mechanisms to predict those with a potentially poor clinical outcome.

Ulnar ray a/hypoplasia: evidence for a developmental field defect on the basis of genetic heterogeneity. Report of three Brazilian families.

We report on five Brazilian patients from three unrelated families with congenital anomalies of the upper limbs. Ulnar aplasia/hypoplasia was the main reason for examining these patients. Evidence for existence of an ulnar developmental field is based on genetic heterogeneity. Clinical and genetic aspects of the ulnar ray defects are discussed.