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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Standard operating procedures (SOP) in experimental stroke research: SOP for middle cerebral artery occlusion in the mouse

Ulrich Dirnagl; Members of the MCAO-SOP Group
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Recently, systematic reviews have found quantitative evidence that low study quality may have introduced a bias into preclinical stroke research. Monitoring, auditing, and standard operating procedures (SOPs) are already key elements of quality control in randomized clinical trials and will hopefully be widely adopted by preclinical stroke research in the near future. Increasingly, funding bodies and review boards overseeing animal experiments are taking a proactive stance, and demand auditable quality control measures in preclinical research. Every good quality control system is based on its SOPs. This article introduces the concept of quality control and presents for the first time an SOP in experimental stroke research.

Visual Molecular Dynamics Investigations of the Impact of Hydrophobic Nanoparticles on Prognosis of Alzheimer’s Disease and Cancers

I. C. Baianu; M Charles; V. I. Prisecaru
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
The possible impact of hydrophobic lectin nanoparticles on the prognosis and progression of Alzheimer's disease (AD) and cancers was investigated by Visual Molecular Dynamics (VMD) computer modeling programs available from the Beckmann Advanced Research Institute at the University of Illinois at Urbana. Our results indicate the possibility of impeding pathological aggregation of certain proteins such as modified tau- or beta-amyloid that are currently being considered as possible causes of Alzheimer's disease. VMD programs serve as useful tools for investigation hydrophobic protein aggregation that may play a role in aging of human populations.

Critical nutritional stress among adult tribal populations of West Bengal and Orissa, India.

Samiran Bisai; Kaushik Bose
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
This paper deals with cross-sectional studies carried out during the period 2004-2007. It is based on eight data sets of tribals of Paschim Medinipur and Bankura Districts of West Bengal and Keonjhar District of Orissa. The tribes include Bhumijs, Kora Mudis, Lodhas, Santals, Bathudis and Savars. Height and weight were measured following standard techniques. The body mass index (BMI) was computed following standard equation. Nutritional status (chronic energy deficiency, CED) was evaluated using internationally accepted cut-off values of BMI. We followed the World Health Organization's classification (1995) of the public health problem of low BMI, based on adult populations worldwide. Our results show that, in general, among the tribes studied: i)Both sexes had very low levels of BMI ii)There existed high rates of CED indicating a critical nutritional condition iii)Women experienced greater nutritional stress iv)The nutritional situation is similar in both West Bengal as well as Orissa.

Strong and weak competitors can coexist in the same niche

Lev V. Kalmykov; Vyacheslav L. Kalmykov
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
The competitive exclusion principle postulates that two trophically identical but fitness different species can not stably coexist in the same niche. However, this principle contradicts the observed nature's species richness. This fact is known as the biodiversity paradox. Here, using a simple cellular automaton model, we mechanistically show how two trophically identical, but fitness different species may stably coexist in the same niche. As environment is stable and any trade-offs are absent in this model, it strongly violates the competitive exclusion principle.

On Asymmetry in Biology and Nature

I. C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Symmetry has attracted a substantial amount of effort because considerable simplifications are possible in the mathematical and physical treatment of phenomena and natural systems that possess a certain degree of symmetry. Among physical and chemical systems the most widely known are those related to crystals and fluids. Whereas crystals have a lattice structure and a symmetry caused by ‘perfect’ order which can be classified by mathematical symmetry groups, most fluids have an average isotropic, highly-disordered ‘structure’ that is often considered to be random.Asymmetry is widely encountered in Biology and ecological systems- from amino acids to trees forests, and tribes, from physiological processes to anatomy- one often finds asymmetry to be present , although symmetries are also encountered whenever nature affords it. An important case is that of cell biomembranes that possess a marked structural and functional asymmetry which is essential to the survival of cells and microorganisms. Asymmetry both in time and selection ‘criteria’ plays a key role in the evolution of organisms and species.

Analysis of DTC nutrigenetic services in Italy: state of the art, agreement to the ESHG statement and future outlooks

Vincenzo Cinque; Fabio Acquaviva; Paola Vergara; Alessandra Cianflone; Imma Castaldo; Antonella Monticelli; Sergio Cocozza; Michele Pinelli
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Background: In both USA and Europe operate companies selling Direct-to-consumer genetic tests (DTC). These tests are offered to healthy people aiming to identify predispositions to complex diseases and to take preventive measures. Several DTC-nutrigenetic tests (DNTs) are available on the market. They propose the definition of a personalized diet, on the basis of the investigated genetic variants, which would reduce the risk of developing those diseases which have been associated to specific genetic markers. However, the risk/benefit balance of exposing unselected population to genetic testing without any medical surveillance is far from be established. Furthermore, it lacks an accepted procedure to select which genetic markers needs to be investigated, to evaluate their specific role and, as consequence, to define a personalized diet. Within this context, the European Society of Human Genetics (ESHG) released a statement regarding the DTC tests that has been ratified by several national societies including the Italian one. In the present study we analyzed the DNT offered in Italy, the state of the art and the abidance with the ESHG statement. Methods: We queried web search engine for the DNT offered to italian population...

Double burden of malnutrition among urban Bengalee adolescent boys in Midnapore, West Bengal, India

S Bisai; R Khongsdier; K Bose; D Mahalanabis
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Malnutrition is an important public health problem worldwide. Therefore a study was undertaken to assess the prevalence of adolescent thinness, overweight and obesity in Midnapore town, West Bengal, India. A total of 974 adolescent boys aged 10-18 years were selected following multistage cluster sampling method from three higher secondary schools. Data was collected using pretested questionnaire following standard technique. Presence of thinness was evaluated using the cut-off values of international survey as suggested by Cole et al (2007). While overweight and obesity was determine by using international cut-off values develop by Cole et al (2000) based on international surveys as recommended by IOTF. Overall the prevalence of thinness, overweight and obesity were 20.8%, 14.9% and 3.8%, respectively. This study developed age specific smooth BMI percentile values using LMS method. Moreover, the study also developed BMI cut-off values to define thinness, overweight and obesity. In conclusion, the present analyses indicated that the prevalence of adolescent undernutrition is still a major problem. In addition, there was also an emerging trend for overweight/obesity, thereby indicating a double burden of malnutrition as observed in other developing countries.

On the origin of the mitochondrial genetic code: Towards a unified mathematical framework for the management of genetic information

Diego Luis Gonzalez; Simone Giannerini; Rodolfo Rosa
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
The origin of the genetic code represents one of the most challenging problems in molecular evolution. The genetic code is an important universal feature of extant organisms and indicates a common ancestry of different forms of life on earth. Known variants of the genetic code can be mainly divided in mitochondrial and nuclear classes. Here we provide a new insight on the origin of the mitochondrial genetic code: we found that its degeneracy distribution can be explained by using a mathematical approach recently developed for the description of the Euplotes nuclear variant of the genetic code. The results point to a primeval mitochondrial genetic code composed of four base codons, which we call tesserae, that, among other features, exhibit outstanding error detection capabilities. The theoretical description suggests also a formulation of a plausible biological theory about the origin of protein coding. Such theory is based on the symmetry properties of hypothetical primeval chemical adaptors between nucleic acids and amino acids (ancient tRNA’s). Our paper provides a unified mathematical framework for different hypotheses on the origin of genetic coding. Also, it contributes to revisit our present view about the evolutionary steps that led to extant genetic codes by giving a new first-principles perspective on the difficult problem of the origin of the genetic code...

Role of cardiac resynchronization therapy in the development of new-onset atrial fibrillation: A single-center prospective study.

Gaetano Santulli; Massimo Chiariello; Cristofaro d'Ascia; Salvatore d'Ascia
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Albeit several studies examined the association between cardiac resynchronization therapy (CRT) and atrial fibrillation (AF) in heart failure (HF), results are still unclear and quite conflicting. We thereby designed a single-center prospective study to determine whether CRT has a favorable effect on the incidence of new-onset AF in a homogeneous population of patients with non-ischemic idiopathic dilated cardiomyopathy and severe heart failure HF. We enrolled 58 patients, AF naïve when received CRT. After 1 year of follow-up our population was subdivided into responders (72.4%) and non (27.6%), so to compare the incidence of AF after 1, 2 and 3 years of follow-up in these two groups. Already after 1 year, there is a significant (p<0.05) difference in new-onset AF in non-responder patients respect to responders (18.2% vs 3.3%). These data are confirmed at 2 year (33.3% vs 12.2%) and 3 year (50.0% vs 15.0%) follow-up. In particular, at 3 year follow-up, non-responders have an increased risk to develop new-onset AF (OR=5.67, 95% confidence interval = 1.36-23.59, p=0.019). The present work suggests a possible favorable role of this non-pharmacological therapy, on the prevention of AF.

Genome Replikin Count Predicts Increased Lethality of Resistant Tuberculosis

Samuel Bogoch; Elenore S. Bogoch
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
The genomic Replikin Count of all the sequences on Pubmed of different strains of tuberculosis were analyzed. The lowest Counts occurred with species within the lowest drug resistance, the highest Counts with sequences of the highest drug resistance and lethality.

Genomic Replikin Count Predicts Increased Lethality of Malaria

Samuel Bogoch; Elenore S. Bogoch
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Genomic Replikin Counts predict both the increase and the decrease of lethality of malaria

Genome Replikin Count Predicts Increased Lethality of Cancer

Samuel Bogoch; Elenore S. Bogoch
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Those cancers, like thyroid and pancreatic cancer, with the lowest 5-year mortality rates, have Replikin Counts of about 20; lung and brain cancers, with the highest 5-year mortality rates, have Replikin Counts of 275 and 325 respectively; the others fall in between with approximate linearity. This is the first quantitative relationship of a genomic structure, Replikins, to 5-year mortality rates.

Genome Replikin Count Predicts Increased Infectivity/Lethality of Viruses

Samuel Bogoch; Elenore S. Bogoch
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
The genomes of all groups of viruses whose sequences are listed on Pubmed, specimens since 1918, analyzed by a software from Bioradar UK Ltd., contain Replikins which range in concentration from a Replikin Count (number of Replikins per 100 amino acids) of less than 1 to 30 (see accompanying communications for higher Counts in tuberculosis, malaria, and cancer, associated with higher lethality). Counts of less than 4.0 were found in ‘resting’ virus states; Counts greater than 4.0, found to be associated with rapid replication, were found invariably to accompany or to predict virus outbreaks, by as much as two years, in viral hosts examined from salmon, to birds, to livestock, to humans. X-ray diffraction showed Replikins to be on the surface of the hemagglutinin gene of influenza and to spread as the Count increased from 3.2 to 10.1, prior to, then during, the 2009 H1N1 influenza pandemic. The degree of lethality of these outbreaks was found to be a function of the statistically significant increase in Replikin Count, particularly in the influenza polymerase gene p B1 or its equivalent in other viruses. Prediction up to two years in advance of the outbreak, and the geographic location of the outbreak, now done in 7/7 trials (see Bogoch...

The Unfolded Protein Response and its potential role in Huntington's disease

Ravi K. R. Kalathur; Kamesh Ayasolla; Matthias E. Futschik
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Huntington's disease (HD) is a progressive, neurodegenerative disease with fatal outcome. Although the disease-causing gene (huntingtin) has been known for some time, the exact cause of neuronal cell death is still unknown. One potential mechanism contributing to the massive loss of neurons in the brain of HD patients might be the unfolded protein response (UPR), which is activated by accumulation of misfolded proteins in the endoplasmatic reticulum (ER). As an adaptive response to counter-balance accumulation of un- or misfolded proteins, the UPR upregulates transcription of chaperones, temporarily attenuates new translation, and activates protein degradation via the proteasome. However, it is known that persistent ER stress and activated UPR can cause cell death by triggering of apoptosis. Nevertheless, the evidence linking UPR with HD progression remains inconclusive. Here, we present first analyses of UPR activation during HD based on available expression data. To elucidate the potential role of UPR as a disease-relevant process, we examine its connection to cell death and inflammatory processes. Due to the complexity of these molecular mechanisms, a systems biology approach was pursued.

A prelude report on molecular docking of HER2 protein towards comprehending anti-cancer properties of saponins from Solanum tuberosum

Puneet K. Singh; Pratyoosh Shukla
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Saponins are extensively known for many biological activities e.g. antimicrobial, anti-palatability, anti-cancer and hemolytic. As cancer cells have a more cholesterol-like compound in their membrane structure the saponins bind cholesterol due to their natural affinity to bind cancer cell membrane. This prevents them from entering the body through the intestinal tract, where they have the ability to attach themselves to vital organs and grow. This study reports the effective use of lower dose saponins like immunotoxin so that they can inhibit the proliferation of cancerous pancreatic cells. The investigation of pancreatic cancer metabolic pathway it was found that proteins 3H3B produced by genes HER-2 are involved in the enhancement of this type of cancer. Further docking studies showed that there is an effective interaction between saponins and cancer cells. The glide score of the saponin analogue compound with CID 21573770 (Pubchem) was -6.30 followed by score of -6.05 and -5.29 for 5-Florouracil and gemcitabine respectively. The interaction was observed in the GLU and GLN rich region, saponins made H-bonds with GLU-188, GLN-119, VAL-72 and GLN-71. This study indicates an effective way towards leading newer prospects for developing saponin analogue based cancer-fighting drugs with improved cancer cell inhibition property without killing normal cells.

Finding Bicliques in Digraphs: Application into Viral-host Protein Interactome

Malay Bhattacharyya; Sanghamitra Bandyopadhyay; Ujjwal Maulik
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Conferência ou Objeto de Conferência
We provide the first formalization true to the best of our knowledge to the problem of finding bicliques in a directed graph. The problem is addressed employing a two-stage approach based on an existing biclustering algorithm. This novel problem is useful in several biological applications of which we focus only on analyzing the viral-host protein interaction graphs. Strong and significant bicliques of HIV-1 and human proteins are derived using the proposed methodology, which provides insights into some novel regulatory functionalities in case of the acute immunodeficiency syndrome in human.

Electron Transfer Pathways in Cell

Yan Liu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Analysis of the electron salvation process data indicates that the electron transfer between the electron donor and acceptor is hindered by the electron salvation process. It is proposed that the electron transfer in the cell environment must be assisted by intermediate messenger called the “transport protein”.

Detecting differential usage of exons from RNA-Seq data

Simon Anders; Alejandro Reyes; Wolfgang Huber
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
RNA-Seq is a powerful tool for the study of alternative splicing and other forms of alternative isoform expression. Understanding the regulation of these processes requires sensitive and specific detection of differential isoform abundance in comparisons between conditions, cell types or tissues. We present DEXSeq, a statistical method to test for differential exon usage in RNA-Seq data. DEXSeq employs generalized linear models and offers reliable control of false discoveries by taking biological variation into account. DEXSeq detects genes, and in many cases specific exons, that are subject to differential exon usage with high sensitivity. We demonstrate the versatility of DEXSeq by applying it to several data sets. The method facilitates the study of regulation and function of alternative exon usage on a genome-wide scale. An implementation of DEXSeq is available as an R/Bioconductor package. This preprint has subsequently been published in Genome Research (doi:10.1101/gr.133744.111)

A call for disruptive innovation in science publishing with a new open data-sharing platform for the life sciences

Donald C. Cooper
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
“A disruptive innovation is an innovation that helps create a new market and value network, and eventually goes on to disrupt an existing market and value network (over a few years or decades), displacing an earlier technology. The term is used in business and technology literature to describe innovations that improve a product or service in ways that the market does not expect.” -Wikipedia On April 3rd, 2012 Nature Precedings, Nature Publishing Group’s experiment in free pre-print publishing was shut down and no longer accepts submissions. According to the Nature Precedings website it was created in 2007 as “a place for researchers to share documents, including presentations, posters, white papers, technical papers, supplementary findings, and non-peer-reviewed manuscripts.” It was designed to “provide a rapid means for scientists to share preliminary findings, disseminate emerging results, solicit community feedback, and claim priority over discoveries.” It was designed in a way to “make such material easy to archive, share and cite.” Now that Nature Precedings is no more, a new disruptive open data-sharing platform (ODSP) for the life sciences is needed. Based...

A novel apparatus/protocol designed for optogenetic manipulation and recording of individual neurons during a motivation and working memory task in the rodent

Samuel Dolzani; Donald C. Cooper
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Innovative molecular tools allow neuroscientists to study neural circuitry associated with specific behaviors. Consequently, behavioral methods must be developed to interface with these new molecular tools in order for neuroscientists to identify the causal elements underlying behavior and decision-making processes. Here we present an apparatus and protocol for a novel Go/No-Go behavioral paradigm to study the brain attention and motivation/reward circuitry in awake, head-restrained rodents. This experimental setup allows: (1) Painless and stable restraint of the head and body; (2) Rapid acquisition to simple or complex operant tasks; (3) Repeated electrophysiological single and multiple unit recordings during ongoing behavior; (4) Pharmacological and viral manipulation of various brain regions via targeted guide cannula, and; (5) Optogenetic cell-type specific activation and silencing with simultaneous electrophysiological recording. In addition to the experimental advantages, the head-restraint system is relatively inexpensive and training parameters can be easily modulated to the specifications of the experimenter. The system runs on custom LabView software. In summary, our novel apparatus and protocol allows researchers to study and manipulate components of behavior...