Desempenho de cultivares de milho em áreas de arroz irrigado do Rio Grande do Sul nas safras 2002/03 e 2003/04.

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CORRELAÇÃO ENTRE MÉTODOS ESPECTROFOTOMÉTRICOS E COLORIMÉTRICOS NA DETERMINAÇÃO DA FOTO E TERMOSSENSIBILIDADE DOS CAROTENOIDES DE TOMATE

The search for natural pigments for application in foods and the challenge of their industrial production has been motivating researchers to investigate their stability to light, temperature, pH and oxygen. A lycopene mixture, obtained from tomato pulp and mineral oil, was prepared to study the photosensitivity and the thermal sensitivity of the pigment. Spectrophotometric and colorimetric determinations were made during the storage period. Light effect was more destructive than the largest temperature evaluated (80°C), and it was observed an abrupt discoloration in some samples, after 30 days of storage. The pigment was little affected when stored under dark at 40°C. Significant correlations between the reduction of absorbances values and the colorimetric coordinates "a*", "b*" and h were obtained. These colorimetric coordinates explained in a best way the variations happened to the pigment.A busca por pigmentos naturais para aplicação em alimentos e o desafio de sua produção industrial tem motivado pesquisadores a investigar sua estabilidade à luz, temperatura, pH e oxigênio. Mistura de licopeno, obtida de polpa de tomate e óleo mineral, foi preparada para se estudar a foto e termossensibilidade do corante. Determinações espectrofotométricas e colorimétricas foram realizadas durante o período de estocagem. O efeito da luz foi mais destrutivo que a maior temperatura avaliada (80°C), sobretudo pela descoloração brusca de algumas amostras após 30 dias de estocagem. O pigmento foi pouco afetado quando armazenado no escuro e a 40°C. Obtiveram-se correlações significativas nas reduções de absorbância com os valores colorimétricos "a*", "b*" e "h". Essas coordenadas foram as que explicaram melhor as variações ocorridas na decomposição do pigmento

ROBÔ AUXILIAR DE BOMBEIRO (R.A.B.)

Grande parte dos perigos de incêndios não são causados pelo fogo, mas sim pelainalação de gases tóxicos. Pesquisas apontam que por volta de 80% dos óbitos são porinalação de vapores e produtos químicos, principalmente monóxido de carbono ecianeto, e não pelas chamas do incêndio. Neste quesito o presente trabalho aborda odesenvolvimento de um robô móvel, de design inspirado nos tanques de guerrabritânicos, com funcionalidades necessárias para o combate de incêndios, onde temcomo principal objetivo prestar apoio aos bombeiros em locais de difícil acesso, paraque não ponham em risco as suas vidas pela dificuldade de acessar o local do acidente ede tempo hábil de socorrer a vítima antes dos gases serem fatais. Os materiaisutilizados serão em grande parte, ferro, alumínio e componentes eletrônicos comoArduíno (Mega), ponte H, módulo Bluetooth (HC-06), entre outros. Junto com issotambém será utilizado uma bateria de moto de 12V, uma bomba de água com vazão de800 l/h, 6 engrenagens de ferro que serão utilizadas como rodas, um bocal demangueira regulável, 2 motores de para-brisa para movimentação, canos de metal paraabastecimento do reservatório da água. Os métodos utilizados para fixação serão: SoldaMig/Mag e Rebites, assim como a solda de estanho. Será usada Cola silicone (PU) paravedação de partes vazadas e tinta para a pintura. Espera-se que ao finalizar o projeto, eleconsiga ser movimentado remotamente através de um aplicativo pelo celular, parafrente, para trás para e os lados (direita e esquerda) girando em seu próprio eixo, econsiga ejetar água através de um botão que deverá ser pressionado, também ao serfinalizado espera-se que suporte até 240°C e seja capaz de percorrer a uma velocidadede 11,2 km/h. Para futuras melhorias considera-se a adição de câmeras para avisualização do ambiente em que se encontrará, para melhor controle dos operadores

Wide field magnetic luminescence imaging

This study demonstrates how magnetic-field-dependent luminescence from organic films can be used to image the magnetic configuration of an underlying sample. The organic semiconductors tetracene and rubrene exhibit singlet exciton fission, which is a process sensitive to magnetic fields. Here, thin films of these materials were characterized using photoluminescence spectrometry, atomic force microscopy, and photoluminescence magnetometry. The luminescence from these substrate-bound thin films is imaged to reveal the magnetic configuration of underlying Nd-Fe-B magnets. The tendency of rubrene to form amorphous films and produce large changes in photoluminescence under an applied magnetic field makes it more appropriate for magnetic field imaging than tetracene. This demonstration can be extended in the future to allow simple microscopic imaging of magnetic structure

The NSL Complex Regulates Housekeeping Genes in Drosophila

MOF is the major histone H4 lysine 16-specific (H4K16) acetyltransferase in mammals and Drosophila. In flies, it is involved in the regulation of X-chromosomal and autosomal genes as part of the MSL and the NSL complexes, respectively. While the function of the MSL complex as a dosage compensation regulator is fairly well understood, the role of the NSL complex in gene regulation is still poorly characterized. Here we report a comprehensive ChIP–seq analysis of four NSL complex members (NSL1, NSL3, MBD-R2, and MCRS2) throughout the Drosophila melanogaster genome. Strikingly, the majority (85.5%) of NSL-bound genes are constitutively expressed across different cell types. We find that an increased abundance of the histone modifications H4K16ac, H3K4me2, H3K4me3, and H3K9ac in gene promoter regions is characteristic of NSL-targeted genes. Furthermore, we show that these genes have a well-defined nucleosome free region and broad transcription initiation patterns. Finally, by performing ChIP–seq analyses of RNA polymerase II (Pol II) in NSL1- and NSL3-depleted cells, we demonstrate that both NSL proteins are required for efficient recruitment of Pol II to NSL target gene promoters. The observed Pol II reduction coincides with compromised binding of TBP and TFIIB to target promoters, indicating that the NSL complex is required for optimal recruitment of the pre-initiation complex on target genes. Moreover, genes that undergo the most dramatic loss of Pol II upon NSL knockdowns tend to be enriched in DNA Replication–related Element (DRE). Taken together, our findings show that the MOF-containing NSL complex acts as a major regulator of housekeeping genes in flies by modulating initiation of Pol II transcription

Analyzing and Modeling Real-World Phenomena with Complex Networks: A Survey of Applications

The success of new scientific areas can be assessed by their potential for contributing to new theoretical approaches and in applications to real-world problems. Complex networks have fared extremely well in both of these aspects, with their sound theoretical basis developed over the years and with a variety of applications. In this survey, we analyze the applications of complex networks to real-world problems and data, with emphasis in representation, analysis and modeling, after an introduction to the main concepts and models. A diversity of phenomena are surveyed, which may be classified into no less than 22 areas, providing a clear indication of the impact of the field of complex networks.Comment: 103 pages, 3 figures and 7 tables. A working manuscript, suggestions are welcome

MR fluoroscopy in vascular and cardiac interventions (review)

Vascular and cardiac disease remains a leading cause of morbidity and mortality in developed and emerging countries. Vascular and cardiac interventions require extensive fluoroscopic guidance to navigate endovascular catheters. X-ray fluoroscopy is considered the current modality for real time imaging. It provides excellent spatial and temporal resolution, but is limited by exposure of patients and staff to ionizing radiation, poor soft tissue characterization and lack of quantitative physiologic information. MR fluoroscopy has been introduced with substantial progress during the last decade. Clinical and experimental studies performed under MR fluoroscopy have indicated the suitability of this modality for: delivery of ASD closure, aortic valves, and endovascular stents (aortic, carotid, iliac, renal arteries, inferior vena cava). It aids in performing ablation, creation of hepatic shunts and local delivery of therapies. Development of more MR compatible equipment and devices will widen the applications of MR-guided procedures. At post-intervention, MR imaging aids in assessing the efficacy of therapies, success of interventions. It also provides information on vascular flow and cardiac morphology, function, perfusion and viability. MR fluoroscopy has the potential to form the basis for minimally invasive image–guided surgeries that offer improved patient management and cost effectiveness

Network Compression as a Quality Measure for Protein Interaction Networks

With the advent of large-scale protein interaction studies, there is much debate about data quality. Can different noise levels in the measurements be assessed by analyzing network structure? Because proteomic regulation is inherently co-operative, modular and redundant, it is inherently compressible when represented as a network. Here we propose that network compression can be used to compare false positive and false negative noise levels in protein interaction networks. We validate this hypothesis by first confirming the detrimental effect of false positives and false negatives. Second, we show that gold standard networks are more compressible. Third, we show that compressibility correlates with co-expression, co-localization, and shared function. Fourth, we also observe correlation with better protein tagging methods, physiological expression in contrast to over-expression of tagged proteins, and smart pooling approaches for yeast two-hybrid screens. Overall, this new measure is a proxy for both sensitivity and specificity and gives complementary information to standard measures such as average degree and clustering coefficients

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency–Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research