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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‣ Hydro tropes as promoters in soap flotation

Abubakar Khadri; Vijay Kumar P; Yasser Dassin; Prabhulingaiah Gowda; Sekhar DMR
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Soaps, the salts of fatty acids are generally used as collectors in the flotation process to separate salt type minerals. Some times light diesel oil is mixed with soaps and the emulsion is used as collector. Addition of detergents to soaps not only enhances the collector efficiency but also reduces the consumption of soap. Urea a known hydro trope is found to improve the flotation efficiency of soaps. Our current testing is indicating that other hydro tropes such as tri sodium citrate and sodium salicylate are also effective in improving the flotation efficiency of soap and also the soap-LDO emulsion.

‣ Sodium Benzoate as Promoter in the Soap Flotation of Phosphate Minerals

Mihir DM; Vijay Kumar P; Prabhulingaiah Gowda
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
In the present study we show that sodium benzoate substantially improves the efficiency of Soap LDO collector in the flotation of phosphate minerals.

‣ Food Physical Chemistry and Biophysical Chemistry

I.C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Food Physical Chemistry is considered to be a branch of Food Chemistry^1,2^ concerned with the study of both physical and chemical interactions in foods in terms of physical and chemical principles applied to food systems, as well as the applications of physical/chemical techniques and instrumentation for the study of foods^3,4,5,6^. This field encompasses the "physiochemical principles of the reactions and conversions that occur during the manufacture, handling, and storage of foods"^7^. Two rapidly growing, related areas are Food Biotechnology and Food Biophysical Chemistry.

‣ Structural characterization of an endoglucanase from _Serpula lacrymans_ var. lacrymans S7.9

Csaba Zoltan Kibedi Szabo; Judit Galicza; Istvan Weyda; Csaba Dezso Andras
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
Lately cellulase enzymes from fungi and also bacteria, have received much attention due to their application in bioethanol production from lignocellulosic feedstock. Dry rot fungus (_Serpula lacrymans_) is known to be the most damaging destroyer of indoor wood construction materials in temperate regions. Therefore the very recent sequencing of this fungus genome has opened new possibilities. We describe here the analysis of the primary, secondary and tertiary structure of a 255 amino acid sequence endoglucanase, from _S. lacrymans_ var. lacrymans S7.9, having a molecular weight of 26746. We also provide the amino acids from the active site.

‣ A Novel NIR Spectroscopy Correlation Approach to Amino Acid Analysis of Soybean Proteins for Composition Improvements- (v.4)

Valentin Prisecaru; I. C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Conferência ou Objeto de Conferência
Português
Amino acid NIR calibrations were developed in our Physical Chemistry of Foods Laboratory of the University of Illinois at Urbana for three selected amino acid groups that include essential amino acids for identified soybean accessions. Conventional “wet chemistry” analytical methods are time-consuming and costly. As a result, soybean breeders and researchers have an imperative need to utilize faster and less expensive methods. NIR Spectroscopy is a rapid and inexpensive method for composition analysis for academia and industry. Recent advancements in instrumentation design, such as the application of the Diode Array (DA) technique and the Fourier Transform (FT) IR and NIR techniques, have significantly improved overall instrument performance and advancement in the field of grain analysis. Novel results are presented for amino acid calibrations for US soybean accessions relevant to the food and agricultural industry.

‣ Collective Animal Behavior from Bayesian Estimation and Probability Matching

Alfonso Perez-Escudero; Gonzalo G. de Polavieja
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Animals living in groups make movement decisions that depend, among other factors, on social interactions with other group members. Our present understanding of social rules in animal collectives is mainly based on empirical fits to observations, with less emphasis in obtaining first-principles approaches that allow their derivation. Here we show that patterns of collective decisions can be derived from the basic ability of animals to make probabilistic estimations in the presence of uncertainty. We build a decision-making model with two stages: Bayesian estimation and probabilistic matching. In the first stage, each animal makes a Bayesian estimation of which behavior is best to perform taking into account personal information about the environment and social information collected by observing the behaviors of other animals. In the probability matching stage, each animal chooses a behavior with a probability equal to the Bayesian-estimated probability that this behavior is the most appropriate one. This model derives very simple rules of interaction in animal collectives that depend only on two types of reliability parameters, one that each animal assigns to the other animals and another given by the quality of the non-social information. We test our model by obtaining theoretically a rich set of observed collective patterns of decisions in three-spined sticklebacks...

‣ Improved Imputation of Common and Uncommon Single Nucleotide Polymorphisms (SNPs) with a New Reference Set

Zhaoming Wang; Kevin Jacobs; Meredith Yeager; Amy Hutchinson; Joshua Sampson; Nilanjan Chatterjee; Demetrius Albanes; Sonja I. Berndt; Charles C. Chung; W. Ryan Diver; Susan M. Gabstur; Lauren R. Teras; Christopher M. Haiman; Brian E. Henderson; Daniel S
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Statistical imputation of genotype data is an important technique for analysis of genome-wide association studies (GWAS). We have built a reference dataset to improve imputation accuracy for studies of individuals of primarily European descent using genotype data from the Hap1, Omni1, and Omni2.5 human SNP arrays (Illumina). Our dataset contains 2.5-3.1 million variants for 930 European, 157 Asian, and 162 African/African-American individuals. Imputation accuracy of European data from Hap660 or OmniExpress array content, measured by the proportion of variants imputed with R^2^>0.8, improved by 34%, 23% and 12% for variants with MAF of 3%, 5% and 10%, respectively, compared to imputation using publicly available data from 1,000 Genomes and International HapMap projects. The improved accuracy with the use of the new dataset could increase the power for GWAS by as much as 8% relative to genotyping all variants. This reference dataset is available to the scientific community through the NCBI dbGaP portal. Future versions will include additional genotype data as well as non-European populations.

‣ Food Physical Chemistry and Biophysical Chemistry (v2)

I. C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Food Physical Chemistry is considered to be a branch of Food Chemistry^1,2^ concerned with the study of both physical and chemical interactions in foods in terms of physical and chemical principles applied to food systems, as well as the applications of physical/chemical techniques and instrumentation for the study of foods^3,4,5,6^. This field encompasses the "physiochemical principles of the reactions and conversions that occur during the manufacture, handling, and storage of foods"^7^. Two rapidly growing, related areas are Food Biotechnology and Food Biophysical Chemistry.

‣ TRPC4 ion channel protein is selectively expressed in a subpopulation of dopamine neurons in the ventral tegmental area

Kurt R. Illig; Andrew L. Varnell; Eric M. Ostertag; William D. Klipec; Donald C. Cooper
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
The nonselective cation channel TRPC4 has been shown to be present in high abundance in the corticolimbic regions of the brain and play a pivotal role in modulating cellular excitability due to their involvement in intracellular Ca^2+^ regulation. Recently we reported their involvement in socialization and regulating anxiety-like behaviors in rats. Given the important role for dopamine in modulating emotions involved in social anxiety we investigated whether TRPC4 protein and mRNA was found on dopaminergic neurons of the ventral tegmental area (VTA). Using emulsion autoradiography we found that TRPC4 mRNA is indeed present in the VTA and the substantia nigra. Additionally, immunohistochemistry verified it’s presence on a subpopulation of dopamine neurons in the VTA. We confirmed these findings by testing Trpc4 knock-out rats in addition to wild-type animals. This novel finding suggests that TRPC4 plays a pivotal role in regulating dopamine release in a sub-population of neurons that may modulate emotional and cognitive responses in social situations.

‣ Semiempirical, Hartree-Fock, density functional, and second order Moller-Plesset perturbation theory methods do not accurately predict ionization energies and electron affinities of short- through long-chain [n]acenes

Sierra Rayne; Kaya Forest
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Vertical, well-to-well, and adiabatic ionization energies (IEs) and electron affinities (EAs) were calculated for the n=1-10 [n]acenes using a wide range of semiempirical, Hartree-Fock, density functional, and second order Moller-Plesset perturbation theory model chemistries. None of the model chemistries examined were able to accurately predict the IEs or EAs for both short- through mid-length [n]acenes, as well as for extrapolations to the polymeric limit, when compared to available experimental and benchmark theoretical data. Provided a minimal basis set size is employed, basis set effects on predicted IEs and EAs are not significant relative to the choice of model chemistry. The poor IE/EA prediction performance for the parent [n]acenes likely extends to their substituted derivatives and heteroatom substituted analogs. Consequently, caution should be exercised in the application of non-high level calculations for estimating the IE/EA of these important classes of materials.

‣ A comparative study on the production of ethanol from lignocellulosic biomass by chemical and biological method

Shaheed SM; Rohit JP; Madhan R; Selvakumar K
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Ethanol derived from non-edible biomass is renewable and a clean source of energy. It is independent of the food industry and it is economically feasible. The first generation biofuel or bioethanol is still not a very convenient source of energy as it prominently depends on the availability of grains. The main objective of this work is to develop an industrious efficient process to produce ethanol from lignocellulosic biomasses like wood and leaf in a lab scale. Two processes were compared. The first process involved an alkaline pre-treatment of the powdered biomass followed by dilute acid hydrolysis. The second process involved an alkaline treatment followed by direct hydrolysis of the biomass by use of a fungal species obtained from rotting wood. Following hydrolysis, fermentation was performed using _Saccharomyces cerevisiae_ and ethanol produced was measured. The process methodologies performed here are liable to be scaled up easily. The final study determines factors such as temperature, strength of the reagents and retention time to maximize ethanol production.

‣ Homology modeling and docking studies to explore the novel drug for monocyte differentiation antigen CD14

Bhimisetty Reshma; Sandeep Swaragam; Amineni Umamaheswari
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
Monocyte differentiation antigen CD14 belongs to the leucine rich family. Elevated levels of monocyte differentiation antigen CD14 and toll-like receptor 4 (TLR4) play a major role in inflammatory response and cause ischemic heart diseases, neuropathic pain and LPS (endotoxin) induced septic shock. IAXO compounds (IAXO-101, IAXO-102 and IAXO-103) inhibit the CD14-dependent and TLR4-independent signaling pathways but they have severe side effects. Due to unavailability of human monocyte differentiation antigen CD14 crystal structure, 3D structure was constructed based on template structure (1WWL) using Modeler 9v9. The modeled structure was refined, energy minimized and validated. Binding site residues of human monocyte differentiation antigen CD14 were predicted using CASTp. The existing compounds were explored in ligand.info database via analog search. Docking analysis was carried out by Schrodinger Maestro 9.2. In the present study, six leads with good pharmacological properties were proposed. Lead 1 (-10.8169 Kcal/mol docking score) has good binding affinity with binding site residues of monocyte differentiation antigen CD14 such as Trp-45, Phe-38, Ala-61, Leu-66, Phe-69, Ile-59, Val-73, Val-96, Ala-99, Ala-100, Val-101, Leu-105...

‣ Adopting Nrf2 and NF-κB from cancer: Is there any role of the duo in diabetes?

Geeta Negi; Ashutosh Kumar; Shyam S. Sharma
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Oxidative stress and inflammation are two well-recognized events occurring in normal cells during cancer chemotherapy. Several antioxidant and anti-inflammatory agents have therefore been tried as rational and effective strategies for chemoprotection. Elaborate studies on antioxidants and anti-inflammatory agents in various experimental models of cancer revealed that these agents act by modulating the expression and/or activity of the transcription factors nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-kappa B (NF-κB). Nrf2 is considered the main sentinel of antioxidant defense as it induces many antioxidant and phase 2 enzymes in response to stressful conditions. Likewise, NF-κB is considered as a denominator of chronic and acute inflammatory processes. In recent years, it was found that a large pool of chemo-preventive and chemo-protective agents that restrain the NF-κB inflammatory cascade also activates Nrf2 signaling. Diabetes and complications thereof are also conditions of amplified oxidative stress and inflammation in various target organs like retina, kidneys, nerves and vasculature. Here we propose that Nrf2 and NF-κB are involved in the etiopathogenesis of diabetes and thus form attractive therapeutic targets. Elucidation of potential involvement of Nrf2 and NF-κB pathways that are operative during multi-organ injury in diabetes may provide basis for development of novel therapies.

‣ Variability of Mauna Loa melt inclusions

Pietro Armienti; Daniela Gasperini
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
A major element of variability of olivine melt inclusions in Mauna Loa lavas is here proved to be strictly related to olivine crystallization at inclusion walls, at low pressure and decreasing temperature. In so doing it is probably worth it to interpret trace elements and isotope variability in these olivine trapped liquids as the effect of disequilibrium (isotope) fractionation. In this respect, the accurate analytical work performed by Sobolev et al. (2011) does not document the presence of a heterogeneous source, rather representing a tool to explore poorly documented aspects of magmatic crystallization that are controlled by the kinetics of liquid-solid phase transition.

‣ Absence of historical temporal trends in monthly, seasonal, and annual streamflows for the Okanagan and Similkameen Rivers in south-central British Columbia, Canada

Sierra Rayne; Kaya Forest
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Potential historical temporal trends in monthly, seasonal, and annual mean, minimum, and maximum streamflows and date of the spring freshet runoff peak were investigated for the Okanagan and Similkameen Rivers in south-central British Columbia, Canada. There appears to be no compelling evidence that streamflow patterns in the Okanagan and Similkameen Rivers have changed over the available hydrometric record, nor does there appear to be evidence that future changes in streamflow patterns are imminent or likely.

‣ Neural Basis of Motivation Lateralizes with Motor Control

Geoffrey Brookshire; Daniel Casasanto
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
According to decades of research on affective motivation in the human brain, approach motivational states are subserved by the left hemisphere and avoidance states by the right hemisphere. Here we show that hemispheric specialization for motivation reverses with handedness. This covariation provides initial support for the Sword and Shield Hypothesis, according to which hemispheric laterality of affective motivation is causally linked to motor control for the dominant and non-dominant hands.

‣ Homology modeling and in silico screening of inhibitors for human CD5 antigen-like protein involved in cardiovascular disease

Varala Sravani; S Rajitha Reddy; Amineni Umamaheswari
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
CD5L (CD5 antigen -like) is a secreted glycoprotein that belongs to the SRCR (scavenger receptor cysteine rich) group B family of proteins that regulate leukocyte function. Over expression of human CD5L leads to Kawasaki disease and atherosclerosis. In the quest of designing novel inhibitors against CD5L, homology models for the protein were predicted based on crystal structures of 1BY2, 2OYA and 2OY3 as multiple templates using Modeller 9v9. The CD5L homology models were selected using GA341 score, DOPE score, PROCHECK and ProSA to select the best model. The selected CD5L model was analyzed using CASTp to locate the largest ligand binding pocket. Five known inhibitors of human CD5L were searched for structural analogs from Ligand.Info Meta database. The structural analog dataset (2000) was docked with CD5L using the three phased docking protocol of Maestro v9.2 that implements Glide v5.7. Seven lead molecules showed better binding affinity (lower XPGscore) compared to five known CD5L inhibitors. The binding orientations of the seven leads compared favorably with known CD5L inhibitors. The seven leads also revealed good pharmacological properties (following Lipinski Rule of Five; Zero reactive functional group) and hence were proposed as new class of CD5L inhibitors. The proposed inhibitors would be useful for rational drug design towards treatment of cardiovascular disease if synthesized and validated in animal models.

‣ Exploring binding site of human RBP4 towards discovery of novel inhibitor for treatment of cardiovascular diseases

C Lakshmi Narayana Rao; LA Raziya Beevi; Amineni Umamaheswari
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
Retinol binding proteins (RBPs) are transport proteins that act by solubilizing and protecting their labile ligands in aqueous spaces. In addition, RBPs have diverse and specific functions in regulating the disposition, metabolism and activities of retinoids. Elevated levels of retinol-binding protein 4 (RBP4) are observed in cardiovascular disease conditions, which prompts it as a potential drug target. Therefore, computational approach methods were implemented herein to design a novel inhibitor for RBP4. Crystal structure (2wq9) of RBP4 was retrieved and investigated to locate retinol binding site residues (Lys29, Pro32, Leu35, Phe36, Leu37, Phe45, Ala55, Ala57, Met73, Val74, Gly75, Met88, Try90, His104, Gln117, Arg121, Try133, Phe135, Phe137). Five existing inhibitors of RBP4 were explored against more than one million entries of the Ligand.Info metadatabase to create an in-house library of 2000 compounds. A ligand dataset was prepared using LigPrep and filtered based on Lipinski’s rule of five and reactive group constraints. The crystal structure was optimized and energy minimized applying OPLS force field in Maestro v9.2. Thirteen leads were found to have good binding affinity towards RBP4 through virtual screening workflow of Maestro. Lead 1...

‣ Bird surveys for REDD+: avian communities indicate forest degradation in a Peruvian coffee landscape

Raf Aerts; Sarah Spranghers; Bruno Verbist; Luc Lens; Cagan Sekercioglu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
Shade coffee cultivation in the Peruvian Andes assists in reducing emissions from deforestation because it avoids conversion to non-forest land uses such as coca and sun grown coffee farming. REDD+ is a potential finance mechanism which may provide incentives for local coffee cooperatives to maintain high shade tree cover. REDD+ has potential multiple benefits other than carbon sequestration, including the conservation of biodiversity. When monitoring for REDD+, surveys of bird biodiversity may prove to be particularly valuable: apart from their high intrinsic value and their value as essential ecosystem service providers, birds inhabiting forest habitats are extremely sensitive to forest loss and forest degradation and are therefore potential useful indicators for the impact of habitat and climate disturbances on biodiversity and environmental health. We analyzed the impact of coffee cultivation on the conservation of birds and assessed what can be learned from bird surveys when monitoring the Peruvian mountain forests for REDD+. Using twelve day-long transect walks, bird species were recorded in two sites in the buffer zone of the Bahuaja-Sonene National Park in SE Peru. The two sites had contrasting human pressure: one site an intimate mixture of shade coffee plantations...

‣ Historical temporal trends in overwinter and spring snowpack for the Okanagan and Similkameen River watersheds in south-central British Columbia, Canada

Sierra Rayne; Kaya Forest
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Potential historical temporal trends in the overwinter and spring snowpack were investigated for the Canadian portions of the Okanagan and Similkameen Valleys in south-central British Columbia. Significant evidence is available that the Okanagan and Similkameen River watersheds are exhibiting both spatially and temporally heterogeneous declines in snowpacks over the past several decades, but whether the causes are part of a natural cycle or result from longer term climatic changes is not clear. The variability in the magnitude, timing, and location of any significant time trends in snowpack decline also precludes efforts towards developing reliable hydrologic models that reflect a response to potential future changes in snowpack patterns for these regions of British Columbia.