Últimos itens adicionados do Acervo: Proceedings Nature

Nature é uma das mais prestigiosas e antigas revistas científicas do mundo: sua primeira edição é de 4 de novembro de 1869. Entre as inúmeras descobertas científicas publicadas na Nature estão a dos raios X, da estrutura em dupla hélice do ADN e o buraco na camada de ozônio.

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‣ Novel Techniques for Microspectroscopy and Chemical Imaging Analysis of Soybean Seeds and Embryos

I. C. Baianu; Tiefeng You; Doina M. Costescu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
Novel methodologies are currently being evaluated for the Chemical Analysis of soybean seeds as well as developing mature soybean embryos by FT-IR/NIR Microspectroscopy. This is the first report of FT-NIR Chemical Images obtained with 1 micron resolution. NIR spectra of Proteins, Oil and DNA fibers are obtained for regions as small as 1μ^2^.

‣ A transgenic rat model for reducing adult neurogenesis.

Jason S. Snyder; Laura Grigereit; Michelle Brewer; Jim Pickel; Heather A. Cameron
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
The function of adult neurogenesis remains unclear. While many tools for manipulating neurogenesis have been developed for mice, there are fewer tools for rats. Radiological and chemical strategies have been used to inhibit adult neurogenesis in rats but these methods may also have undesired side effects. Since rats have a larger brain and can perform complex behaviors, it would be useful to have additional rat models for studying neurogenesis. To address this gap we therefore developed a transgenic GFAP-TK rat in which adult neurogenesis can be specifically inhibited. Preliminary results suggest that, as in mice, reduced adult neurogenesis leads to anhedonia.

‣ Applications Of Microspectroscopy, Hyperspectral Chemical Imaging And Fluorescence Microscopy In Chemistry, Biochemistry, Biotechnology, Molecular And Cell Biology

I. C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Chemical imaging is a technique for the simultaneous measurement of spectra (chemical information) and images or pictures (spatial information)^1,2^. The technique is most often applied to either solid or gel samples, and has applications in chemistry, biology^3-8^, medicine^9,10^, pharmacy^11^ (see also for example: Chemical Imaging Without Dyeing), food science, Food Physical Chemistry, Biotechnology^12,13^, Agriculture and industry. NIR, IR and Raman chemical imaging is also referred to as hyperspectral, spectroscopic, spectral or multi-spectral imaging (also see micro-spectroscopy). However, other ultra-sensitive and selective, chemical imaging techniques are also in use that involve either UV-visible or fluorescence microspectroscopy.

‣ Prebiotic Organic Microstructures

Marie-Paule BASSEZ; Yoshinori TAKANO; Kensei KOBAYASHI
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Micro- and sub-micrometer spheres, tubules and fiber-filament soft structures have been synthesized in our experiments conducted with 3 MeV proton irradiations of a mixture of simple inorganic constituents, CO, N2 and H2O. We analysed the irradiation products, with scanning electron microscopy (SEM) and atomic force microscopy (AFM). These laboratory organic structures produced wide variety of proteinous and non-proteinous amino acids after HCl hydrolysis. The enantiomer analysis for D-, L- alanine confirmed that the amino acids were abiotically synthesized during the laboratory experiment. Considering hydrothermal activity, the presence of CO2 and H2, of a ferromagnesian silicate mineral environment, of an Earth magnetic field which was much less intense during Archean times than nowadays and consequently of a proton excitation source which was much more abundant, we propose that our laboratory organic microstructures might be synthesized during Archean times. We show similarities in morphology and in formation with some terrestrial Archean microstructures and we suggest that some of the observed Archean carbon spherical and filamentous microstructures might be composed of abiogenic organic molecules. We further propose a search for such prebiotic organic signatures on Mars. This article has been posted on Nature precedings on 21 July 2010 [1]. Extinct radionuclides as source of excitation have been replaced by cosmic radiations which were much more intense 3.5 Ga ago because of a much less intense Earth magnetic field. The new version of the article has been presented at the ORIGINS conference in Montpellier in july 2011 [2] and has since been published in Origins of Life and Evolution of Biospheres 42 (4) 307-316...

‣ Impact of tissue microstructure on a model of cardiac electromechanics based on MRI data

Valentina Carapella; Vicente Grau; Pras Pathmanathan; Kevin Burrage
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
Cardiac motion is a vital process as it sustains the pumping of blood in the body. For this reason motion abnormalities are often associated with severe cardiac pathologies. Clinical imaging techniques, such as MRI, are powerful in assessing motion abnormalities but their connection with pathology often remains unknown. Computational models of cardiac motion, integrating imaging data, would thus be of great help in linking tissue structure (i.e. cells organisation into fibres and sheets) to motion abnormalities and to pathology. Current models, though, are not able yet to correctly predict realistic cardiac motion in the healthy or diseased heart. Our hypothesis is that a more realistic description of tissue structure within an electromechanical model of the heart, with structural information extracted from data rather than mathematically defined, and a more careful definition of tissue material properties, would better represent the high heterogeneity of cardiac tissue, thus improving the predictive power of the model.

‣ Biochemical Composition of Normal Urine

Atif Baig
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Conferência ou Objeto de Conferência
Português
The urine composition defines the quality of homeostasis of the body. Learning about the normal urine composition is very important to compare it with the suspended and non suspended particles in urine in different pathologies.

‣ Introduction to Medical Genetics

Atif A. Baig
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
Medical genetics is the key to modern biochemistry and underlying mechanisms of many diseases.

‣ Soybean Composition Database from NIR, NMR and GC-MS Analyses

I. C. Baianu; Tiefeng You; Jun Guo; Doina M. Costescu; V. I. Prisecaru
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
This novel Soybean Composition Database from the AFC-NMR & NIR Spectroscopy Facility of the College of ACES at the University of Illinois at Urbana includes more than 12,000 NIR measurements on soybeans from the International Soybean Germplasm Collection, such as those received from Peking at the National Soybean Collection. Excel files (.xls) of our novel spectroscopic data are currently available for all 80,000 + NIR and FT-NMR measurements; such data are made available from an ultra-fast and secure supercomputer server utilizing the current version of the Scientific-Linux OS-based software. A detailed account is also presented of our high-resolution nuclear magnetic resonance (HR-NMR) and near infrared (NIR) calibration models, methodologies and validation procedures, together with a large number of composition analyses for soybean seeds. NIR calibrations were developed based on both HR-NMR and analytical chemistry reference data for oil and twelve amino acid residues in mature soybeans and soybean embryos. Moreover, this is our first detailed report of HR-NMR determinations of amino acid profiles of proteins from whole soybean seeds, without protein extraction from the seed. It was found that the best results for both oil and protein calibrations were obtained with a Partial Least Squares Regression (PLS-1) analysis of our extensive NIR spectral data...

‣ Soybean Composition Database from NIR, NMR and GC-MS Analyses- (v.3)

I. C. Baianu; Tiefeng You; Jun Guo; Doina M. Costescu; V. I. Prisecaru
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
This novel Soybean Composition Database from the AFC-NMR & NIR Spectroscopy Facility of the College of ACES at the University of Illinois at Urbana includes more than 12,000 NIR measurements on soybeans from the International Soybean Germplasm Collection, such as those received from Peking at the National Soybean Collection. Excel files (.xls) of our novel spectroscopic data are currently available for all 80,000 + NIR and FT-NMR measurements; such data are made available from an ultra-fast and secure supercomputer server utilizing the current version of the Scientific-Linux OS-based software. A detailed account is also presented of our high-resolution nuclear magnetic resonance (HR-NMR) and near infrared (NIR) calibration models, methodologies and validation procedures, together with a large number of composition analyses for soybean seeds. NIR calibrations were developed based on both HR-NMR and analytical chemistry reference data for oil and twelve amino acid residues in mature soybeans and soybean embryos. Moreover, this is our first detailed report of HR-NMR determinations of amino acid profiles of proteins from whole soybean seeds, without protein extraction from the seed. It was found that the best results for both oil and protein calibrations were obtained with a Partial Least Squares Regression (PLS-1) analysis of our extensive NIR spectral data...

‣ Novel Techniques for Microspectroscopy and Chemical Imaging Analysis of Soybean Seeds and Embryos

I. C. Baianu; Tiefeng You; Doina M. Costescu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
Novel methodologies are currently being evaluated for the Chemical Analysis of soybean seeds as well as developing mature soybean embryos by FT-IR/NIR Microspectroscopy. This is the first report of FT-NIR Chemical Images obtained with 1 micron resolution. NIR spectra of Proteins, Oil and DNA fibers are obtained for regions as small as 1μ^2^.

‣ First Report of 1 Micron Spatial Resolution Chemical Imaging of a Zirconium Single Crystal by FT-NIR Microspectroscopy

I. C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
This is the first report of 1 micron resolution chemical images of a Zirconium single crystal by FT-NIR Microspectroscopy. The FT-NIR spectra were obtained with a PerkinElmer SpectrumONE NTS spectrometer. The chemical images were obtained with a PerkinElmer Autoimage model FT-NIR microscope equipped with a very high sensitivity In /GaAs detector capable of precise measurements at ~10 ng, that was coupled to the SpectrumONE NTS FT-NIR spectrometer.

‣ Ligand based virtual screening studies to design drug molecules for human PIN1 causing cardiovascular disease

C Ramana; Manne Munikumar; Amineni Umamaheswari
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
PIN1 is a member of the cis/trans peptidyl-prolyl isomerase family which plays critical roles in cell-cycle regulation. Over expression of PIN1 in endothelial cells causes cardiovascular disease. The present study has focused on computational analysis to identify the potential inhibitors for PIN1. The human PIN1 crystal structure was retrieved from the protein data bank and prepared using protein preparation wizard of Maestro v9.2. Fourteen PIN1 inhibitors reported in recent literature were acquired and searched for structural analogs using Ligand.Info tool. 5675 PIN1 inhibitor analogs yielded were converted to 3D structures using LigPrep with constraints of ADME evaluation and toxicity assessments. The 3D ligand dataset was docked to PIN1 through docking protocol of Glide v5.7. Nine leads showing better binding affinity compared to fourteen published inhibitors were proposed as potential inhibitors of PIN1. The Lead 1 (2-(2-hydroxy-5-methoxy-pheny)-1h-benzoimidazole-5-carboxamidine) showed a docking score of -7.543 kcal/mol with strong hydrogen bond network with active site residues such as Arg-74, Tyr-92 and Glu-110 and good van der Waals interaction. Therefore, Lead 1 is proposed as a promising lead for developing potential drug molecules for cardiovascular disease therapy.

‣ A potential cyanobacterial ancestor of Viridiplantae chloroplasts

Wriddhiman Ghosh; Prabir Haldar; Sabyasachi Bhattacharya; Jaideb Chatterjee; Prosenjit Pyne; Masrure Alam
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
The theory envisaging the origin of plastids from endosymbiotic cyanobacteria is well-established but it is difficult to explain the evolution (spread) of plastids in phylogenetically diverse plant groups. It is widely believed that primordial endosymbiosis occurred in the last common ancestor of all algae^1^, which then diverged into the three primary photosynthetic eukaryotic lineages, viz. the Rhodophyta (red algae), Glaucocystophyta (cyanelle-containing algae) and Viridiplantae (green algae plus all land plants)^2^. Members of these three groups invariably have double membrane-bound plastids^3^, a property that endorses the primary endosymbiotic origin of the organelles. On the other hand, the three or four membrane-bound plastids of the evolutionary complicated Chromalveolates [chromista (cryptophytes, haptophytes, and stramenopiles) and alveolata (dinoflagellates, apicomplexans, and ciliates)] are inexplicable in the light of a single endosymbiosis event, thereby necessitating the postulation of the secondary^4,5^ and tertiary^6^ endosymbiosis theories where a nonphotosynthetic protist supposedly engulfed a red or a green alga^7^ and an alga containing a secondary plastid itself was engulfed^8^ respectively. In the current state of understanding...

‣ Identification of MHC Class II Binders/ Non-binders using Negative Selection Algorithm

S.S. Soam; Feroz Khan; Bharat Bhasker; B. N. Mishra
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
The identification of major histocompatibility complex (MHC) class-II restricted peptides is an important goal in human immunological research leading to peptide based vaccine design. These MHC class–II peptides are predominantly recognized by CD4+ T-helper cells, which when turned on, have profound immune regulatory effects. Thus, prediction of such MHC class-II binding peptides is very helpful towards epitope-based vaccine design. HLA-DR proteins were found to be associated with autoimmune diseases e.g. HLA-DRB1*0401 with rheumatoid arthritis. It is important for the treatment of autoimmune diseases to determine which peptides bind to MHC class II molecules. The experimental methods for identification of these peptides are both time consuming and cost intensive. Therefore, computational methods have been found helpful in classifying these peptides as binders or non-binders. We have applied negative selection algorithm, an artificial immune system approach to predict MHC class–II binders and non-binders. For the evaluation of the NSA algorithm, five fold cross validation has been used and six MHC class–II alleles have been taken. The average area under ROC curve for HLA-DRB1*0301, DRB1*0401, DRB1*0701, DRB1*1101...

‣ Identity in research infrastructure and scientific communication: Report from the 1st IRISC workshop, Helsinki Sep 12-13, 2011

Gudmundur A. Thorisson; Mikael Linden; Anthony J. Brookes; Myles Byrne; Juha Muilu; Tommi Nyronen
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Motivation for the IRISC workshop came from the observation that identity and digital identification are increasingly important factors in modern scientific research, especially with the now near-ubiquitous use of the Internet as a global medium for dissemination and debate of scientific knowledge and data, and as a platform for scientific collaborations and large-scale e-science activities. The 1 1/2 day IRISC2011 workshop sought to explore a series of interrelated topics under two main themes: i) unambiguously identifying authors/creators & attributing their scholarly works, and ii) individual identification and access management in the context of identity federations. Specific aims of the workshop included: • Raising overall awareness of key technical and non-technical challenges, opportunities and developments. • Facilitating a dialogue, cross-pollination of ideas, collaboration and coordination between diverse – and largely unconnected – communities. • Identifying & discussing existing/emerging technologies, best practices and requirements for researcher identification. This report provides background information on key identification-related concepts & projects...

‣ NIR Calibrations for Soybean Seeds and Soy Food Composition Analysis: Total Carbohydrates, Oil, Proteins and Water Contents

I. C. Baianu; Jun Guo
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Conventional chemical analysis techniques are expensive, time consuming, and often destructive. The non-invasive Near Infrared (NIR) technology was introduced over the last decades for wide-scale, inexpensive chemical analysis of food and crop seed composition (see Williams and Norris, 1987; Wilcox and Cavins, 1995; Buning and Diller, 2000 for reviews of the NIR technique development stage prior to 1998, when Diode Arrays were introduced to NIR). NIR spectroscopic measurements obey Lambert and Beer’s law, and quantitative measurements can be successfully made with high speed and ease of operation. NIR has been used in a great variety of food applications. General applications of products analyzed come from all sectors of the food industry including meats, grains, and dairy products (Shadow, 1998).

‣ NIR Calibrations for Soybean Seeds and Soy Food Composition Analysis: Total Carbohydrates, Oil, Proteins and Water Contents [v.2]

I. C. Baianu; Jun Guo; Randall L. Nelson; Tiefeng You; Doina M. Costescu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Conventional chemical analysis techniques are expensive, time consuming, and often destructive. The non-invasive Near Infrared (NIR) technology was introduced over the last decades for wide-scale, inexpensive chemical analysis of food and crop seed composition (see Williams and Norris, 1987; Wilcox and Cavins, 1995; Buning and Diller, 2000 for reviews of the NIR technique development stage prior to 1998, when Diode Arrays were introduced to NIR). NIR spectroscopic measurements obey Lambert and Beer’s law, and quantitative measurements can be successfully made with high speed and ease of operation. NIR has been used in a great variety of food applications. General applications of products analyzed come from all sectors of the food industry including meats, grains, and dairy products (Shadow, 1998). Novel NIR calibrations for rapid, reliable and accurate composition analysis of a variety of several soy based foods and bulk soybean seeds were developed and validated in a six-year collaborative project with a large number of different samples (N >~12, 000). The availability of such calibrations is important for establishing NIR as a secondary method for composition analysis of foods and soybeans both in applications and fundamental research.

‣ Towards more Challenging Problems for Ontology Matching Tools

Ernesto Jimenez-Ruiz; Bernardo Cuenca Grau
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
We motivate the need for challenging problems in the evaluation of ontology matching tools. To address this need, we propose mapping sets between well-known biomedical ontologies that are based on the UMLS Metathesaurus. These mappings could be used as a basis for a new track in future OAEI campaigns (http://oaei.ontologymatching.org/).

‣ Isolated ileal interposition in enteroendocrine L cells differentiation

Bianca Marigliani; Joao-Luiz M. C. Azevedo; Lucas P. F. F. Leal; Karina F. Neves; Linda O. A. Bernardes; Gilmara S. Aguiar-Yamaguchi; Wellington Cardia; João L. C. Azevedo; Otavio C. Azevedo; Jose F. Borborema; Gustavo P. S. Miguel
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
INTRODUCTION: Due to the progressive nature of type 2 diabetes, its complexity and drug treatment perpetuity, there is currently a search for surgical procedures that can promote euglycemia also in non-obese patients. Diabetic patients glycemic control can be achieved by increasing the blood concentration of GLP-1, a hormone produced by L cells that are more densely concentrated in the terminal ileum. Early and extended improvement of diabetes in patients submitted to bariatric surgeries awakened the necessity of investigating the isolated ileal interposition as a surgical alternative for the treatment of diabetes. The interposition of this ileal segment to a more anterior region (proximal jejunum) can promote a greater stimulation of the L cells by poorly digested food, increasing the production of GLP-1 and reflecting on glycemic control. However, in order to consolidate the ileal interposition as a surgical treatment of diabetes it is necessary that the interposed ileum keep the same differentiation rate into L cells for a long period to justify the intervention. AIMS: To investigate the isolated ileal interposition influence on the differentiation of intestinal precursor cells into enteroendocrine L cells over time. METHODS: Twelve 12-week-old male Wistar rats (Rattus norvegicus albinus) of the WAB strain (heterogeneous) will be used. All animals will receive a high-calorie...

‣ Generalized time-frequency coherency for assessing neural interactions in electrophysiological recordings

Saeid Mehrkanoon; Michael Breakspear; Andreas Daffertshofer; Tjeerd W. Boonstra
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Time-frequency coherence has been widely used to quantify statistical dependencies in bivariate data and has proven to be vital for the study of neural interactions in electrophysiological recordings. Conventional methods establish time-frequency coherence by smoothing the cross and power spectra using identical smoothing procedures. Smoothing entails a trade-off between time-frequency resolution and statistical consistency and is critical for detecting instantaneous coherence in single-trial data. Here, we propose a generalized method to estimate time-frequency coherency by using different smoothing procedures for the cross spectra versus power spectra. This novel method has an improved trade-off between time resolution and statistical consistency compared to conventional methods, as verified by two simulated data sets. The methods are then applied to single-trial surface encephalography recorded from human subjects for comparative purposes. Our approach extracted robust alpha- and gamma-band synchronization over the visual cortex that was not detected by conventional methods, demonstrating the efficacy of this method.