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| Registros recuperados: 2.284 | |
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| Silvanus G. Otieno; Jesse T. Njoka; Truman P. Young; Stephen M. Mureithi; Robinson K. Ngugi. |
| The controversy that has surrounded herbivory studies in the last few decades prompted our investigation to establish the extent to which herbivore optimisation hypothesis or compensatory growth evidence is real. We used the traditional movable cage method to collect primary productivity data on herbage, functional groups and key individual grass species in various controlled large herbivore treatments in an east African savanna. The herbivore treatments in triplicate blocks included cattle, wild herbivores with and without mega herbivores and combinations of cattle and wild herbivores also with and without mega herbivores. The findings revealed that at herbage level, most grazed treatments (four out of five) had higher productivity than the ungrazed... |
| Tipo: Manuscript |
Palavras-chave: Ecology. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3452/version/1 |
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| Sierra Rayne; Kaya Forest. |
| 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. |
| Tipo: Manuscript |
Palavras-chave: Earth & Environment. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6584/version/1 |
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| Silvia Vilasi; Raffaele Ragone. |
| The potent immunomodulatory, anti-inflammatory and procoagulant properties of the
protein no. 4 secreted from the rat seminal vesicle epithelium (SV-IV) have been
previously found to be modulated by a supramolecular monomer-trimer equilibrium.
More structural details that integrate experimental data into a predictive framework
have recently been reported. Unfortunately, homology modelling and fold-recognition
strategies were not successful in creating a theoretical model of the structural
organization of SV-IV. It was inferred that the global structure of SV-IV is not similar
to any protein of known three-dimensional structure. Reversing... |
| Tipo: Manuscript |
Palavras-chave: Bioinformatics. |
| Ano: 2007 |
URL: http://precedings.nature.com/documents/1394/version/1 |
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| Liliana M. Dávalos; Ana L. Porzecanski. |
| Different frameworks have been proposed for using molecular data in systematic revisions, but there is ongoing debate on their applicability, merits and shortcomings. In this paper we examine the fit between morphological and molecular data in the systematic revision of Paroaria, a group of conspicuous songbirds endemic to South America. We delimited species based on examination of > 600 specimens, and developed distance-gap, and distance- and character-based coalescent simulations to test species limits with molecular data. The morphological and molecular data collected were then analyzed using parsimony, maximum likelihood, and Bayesian phylogenetics. The simulations were better at evaluating the new species limits than using genetic distances.... |
| Tipo: Manuscript |
Palavras-chave: Evolutionary Biology. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3357/version/1 |
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| Marc Wittmann; Alan N. Simmons; Jennifer L. Aron; Martin P. Paulus. |
| The experience of time, i.e. the estimation of duration, is fundamental for perception and behavior and, therefore, essential for the survival of the individual organism. Over the last decades, neuroimaging, neurophysiological and clinical neuropsychological studies have pointed to many different brain areas involved in the processing of time. However, the core neural substrates and the processes accounting for the encoding of duration, which could form a timekeeping mechanism (essentially, a neural clock), are still unknown. Here we present evidence of neurophysiological activity in circumscribed areas of the human brain that is involved in the encoding of duration. Time-activity curves of neural activation derived from event-related functional magnetic... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/2062/version/1 |
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| Sierra Rayne; Kaya Forest. |
| Gas to aqueous phase standard state (1 atm to 1 mol/L; 298.15 K) free energies of solvation ([DELTA]G^o^~solv~) were calculated for a range of neutral and ionic inorganic and organic compounds using various levels and combinations of Hartree-Fock and density functional theory (DFT) and composite methods (CBS-Q//B3, G4MP2, and G4) with the IEFPCM-UFF, CPCM, and SMD solvation models in Gaussian 09 (G09). For a subset of highly polar and generally polyfunctional neutral organic compounds previously identified as problematic for prior solvation models, we find significantly reduced [DELTA]G^o^~solv~ errors using the revised solvent models in G09. The use of composite methods for these compounds also substantially reduces their apparent [DELTA]G^o^~solv~... |
| Tipo: Manuscript |
Palavras-chave: Chemistry. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4864/version/1 |
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| Scott L. Carter; Matthew Meyerson; Gad Getz. |
| Interpretation of allelic copy measurements at polymorphic markers in cancer samples presents distinctive challenges and opportunities. Due to frequent gross chromosomal alterations occurring in cancer (aneuploidy), many genomic regions are present at homologous-allele imbalance. Within such regions, the unequal contribution of alleles at heterozygous markers allows for direct phasing of the haplotype derived from each individual parent. In addition, genome-wide estimates of homologue specific copy- ratios (HSCRs) are important for interpretation of the cancer genome in terms of fixed integral copy-numbers. We describe HAPSEG, a probabilistic method to interpret bi- allelic marker data in cancer samples. HAPSEG operates by partitioning the genome into... |
| Tipo: Manuscript |
Palavras-chave: Cancer; Genetics & Genomics; Bioinformatics. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6494/version/1 |
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| Nicolo Fusi; Oliver Stegle; Neil Lawrence. |
| Expression quantitative trait loci (eQTL) studies are an integral tool to investigate the genetic component of gene expression variation. A major challenge in the analysis of such studies are hidden confounding factors, such as unobserved covariates or unknown environmental influences. These factors can induce a pronounced artifactual correlation structure in the expression profiles, which may create spurious false associations or mask real genetic association signals. 

Here, we report PANAMA (Probabilistic ANAlysis of genoMic dAta), a novel probabilistic model to account for confounding factors within an
eQTL analysis. In contrast to previous methods, PANAMA learns hidden factors jointly with the... |
| Tipo: Manuscript |
Palavras-chave: Genetics & Genomics; Bioinformatics. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/5995/version/1 |
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| Athanasios Tsanas; Max A. Little; Patrick E. McSharry; Lorraine O. Ramig. |
| Tracking Parkinson's disease (PD) symptom progression often uses the Unified Parkinson’s Disease Rating Scale (UPDRS), which requires the patient's presence in clinic, and time-consuming physical examinations by trained medical staff. Thus, symptom monitoring is costly and logistically inconvenient for patient and clinical staff alike, also hindering recruitment for future large-scale clinical trials. Here, for the first time, we demonstrate rapid, remote replication of UPDRS assessment with clinically useful accuracy (about 7.5 UPDRS points difference from the clinicians’ estimates), using only simple, self-administered, and non-invasive speech tests. We characterize speech with signal processing algorithms,... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience; Bioinformatics. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3920/version/1 |
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| Asuka Suzuki-Hirano; Tatsuya Sato; Harukazu Nakamura. |
| In the previous studies, we showed that strong Fgf8 signaling activates the Ras-ERK pathway to induce cerebellum. Here, we show importance of negative regulation of this pathway. 'Prolonged' activation of ERK by misexpression of _Fgf8b_ and dominant-negative _Sprouty2_ (_dnSprouty2_) did not change the fate of the mesencephalic alar plate. Downregulation of ERK activity using a MEK inhibitor, U0126, or by tetracycline dependent Tet-off system after co-expression of _Fgf8b_ and _dnSprouty2_, forced the mesencephalic alar plate to differentiate into cerebellum. We then paid attention to Mkp3. After misexpression of _dnMkp3_ and _Fgf8b_, slight downregulation of ERK activity occurred, which may be due to Sprouty2, and the mesencephalon... |
| Tipo: Manuscript |
Palavras-chave: Developmental Biology; Molecular Cell Biology; Neuroscience. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/2089/version/1 |
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| Stephan Persengiev. |
| RNA interference (RNAi) is a conserved biological response to double-stranded RNAs that results in posttranscriptional silencing of target gene expression. Double-stranded processed RNAs of 21-23 nt were found to affect in a non-specific manner a number of signaling and transcription pathways, including interferon and PKR cascades. We report here that siRNAs induce the expression of general transcription factor TRF3, which can trigger an interferon response in mammalian cells. |
| Tipo: Manuscript |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2007 |
URL: http://precedings.nature.com/documents/1206/version/1 |
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| Cheng-Ta Yang; Jhy-Ming Li; Hsu-Huei Weng; Ya-Chin Li; Miao-Fen Chen. |
| Expression of survivin has been reported to be correlated with shorter survival in patients with non-small cell lung cancer (NSCLC), and overexpression of survivin may lead to radioresistance in various human cancers. In this study, we inhibited survivin expression by using an adenoviral vector (AdsiSurvivin)-mediated RNAi to elucidate the combined effect of survivin-targeting gene therapy and radiotherapy on the NSCLC cells. Our data revealed that AdsiSurvivin exerted survivin gene silencing, induced apoptosis, and significantly attenuated the growth potential in NSCLC cells within 72 hours after infection. The combined treatment modalities with AdsiSurvivin infection and radiation were significantly more potent on cell-growth inhibition than monotherapy.... |
| Tipo: Manuscript |
Palavras-chave: Cancer; Molecular Cell Biology. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/2589/version/1 |
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| Alessandro Cucchi; Mauro Bergamini. |
| *INTRODUCTION* - In order to define subjective variables, the methodology on the assessment of the women participation to screening programs to prevent cervical cancer is presented.
*MATERIALS AND METHODS* - The study was conducted using a structured questionnaire administered by telephone to a sample of women invited to screening, regardless of their real participation to the Pap test. The phone calls were made within 2 days prior to the Pap test session. The questionnaire contained 12 closed questions.	
*RESULTS* - We contacted a total of 1206 women: a total of 1100 women (93.70%) received the invitation letter and answered to the questionnaire.	
*CONCLUSIONS* - The chosen procedure... |
| Tipo: Manuscript |
Palavras-chave: Cancer. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3016/version/1 |
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| Sierra Rayne; Kaya Forest. |
| Perfluoroalkyl carboxylates are contaminants whose environmental fate and toxicological effects are of broad interest within the academic, industrial, and governmental science and regulatory communities. In addition, coupled perfluoroalkyl and carboxylate moieties are often used in medicinal chemistry as part of the drug design process. However, to date there has been a notable absence of reliable acidity constant estimation programs for these compounds. Here we report that the ADME/Tox WEB method for in silico pKa value predictions is more accurate than the PM6, SPARC, and COSMOtherm methods for the longer chain perfluoroalkyl carboxylic acids, suggesting this may be a good general acidity constant estimation approach for these compounds. |
| Tipo: Manuscript |
Palavras-chave: Chemistry; Pharmacology; Earth & Environment. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/2936/version/1 |
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| Geeta Negi; Ashutosh Kumar; Shyam S. Sharma. |
| 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... |
| Tipo: Manuscript |
Palavras-chave: Cancer; Pharmacology. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6581/version/1 |
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| Lucas Wardil; Jafferson K. L. da Silva. |
| The emergence of cooperation has been widely studied in the context of game theory on structured populations. Usually the individuals adopt one strategy against all their neighbors. The structure can provide reproductive success for the cooperative strategy, at least for low values of defection tendency. Other mechanisms, such punishment, can also be responsible for cooperation emergence. But what happens if the players adopt simultaneously different strategies against each one of their opponents, not just a single one? Here we study this question in the prisoner dilemma scenario structured on a square lattice and on a ring. We show that if an update rule is defined in which the players replace the strategy that furnishes the smallest payoff, a... |
| Tipo: Manuscript |
Palavras-chave: Evolutionary Biology. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3035/version/1 |
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| Registros recuperados: 2.284 | |
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