共查询到20条相似文献,搜索用时 15 毫秒
1.
Background
Much communicable disease control research has had little impact on local control programme policy and practice for want of an operational component. The operational research model – the systematic search for knowledge on interventions, tools or strategies that enhance programme effectiveness – is gaining recognition as an appropriate method for addressing perplexing questions within public health programmes. 相似文献2.
Monika Witusik Sylwester Piaskowski Krystyna Hulas-Bigoszewska Magdalena Zakrzewska Sylwia M Gresner S Ausim Azizi Barbara Krynska Pawel P Liberski Piotr Rieske 《BMC biotechnology》2008,8(1):56
Background
Although extensive research has been performed to control differentiation of neural stem cells – still, the response of those cells to diverse cell culture conditions often appears to be random and difficult to predict. To this end, we strived to obtain stabilized protocol of NHA cells differentiation – allowing for an increase in percentage yield of neuronal cells. 相似文献3.
Background
High-throughput genomic research tools are becoming standard in the biologist's toolbox. After processing the genomic data with one of the many available statistical algorithms to identify statistically significant genes, these genes need to be further analyzed for biological significance in light of all the existing knowledge. Literature mining – the process of representing literature data in a fashion that is easy to relate to genomic data – is one solution to this problem. 相似文献4.
Background
Identifying large gene regulatory networks is an important task, while the acquisition of data through perturbation experiments (e.g., gene switches, RNAi, heterozygotes) is expensive. It is thus desirable to use an identification method that effectively incorporates available prior knowledge – such as sparse connectivity – and that allows to design experiments such that maximal information is gained from each one. 相似文献5.
Hunger RE Kernland Lang K Markowski CJ Trachsel S Møller M Eriksen JA Rasmussen AM Braathen LR Gaudernack G 《Cancer immunology, immunotherapy : CII》2011,60(11):1553-1564
Purpose
A phase I study was conducted to investigate the safety, tolerability, and immunological responses to vaccination with a combination of telomerase-derived peptides GV1001 (hTERT: 611–626) and p540 (hTERT: 540–548) using granulocyte–macrophage colony-stimulating factor (GM-CSF) or tuberculin as adjuvant in patients with cutaneous melanoma. 相似文献6.
Background
Low molecular weight heparins hold several advantages over unfractionated heparin including convenience of administration. Enoxaparin is one such heparin licensed in the UK for use in unstable coronary artery disease (unstable stable angina and non-Q wave myocardial infarction). In these patients, two large randomised controlled trials and their meta-analysis showed small benefits for enoxaparin over unfractionated heparin at 30–43 days and potentially at one year. 相似文献7.
Background
An increasing number of scientific research projects require access to large-scale computational resources. This is particularly true in the biological field, whether to facilitate the analysis of large high-throughput data sets, or to perform large numbers of complex simulations – a characteristic of the emerging field of systems biology. 相似文献8.
Background
The performance of alignment programs is traditionally tested on sets of protein sequences, of which a reference alignment is known. Conclusions drawn from such protein benchmarks do not necessarily hold for the RNA alignment problem, as was demonstrated in the first RNA alignment benchmark published so far. For example, the twilight zone – the similarity range where alignment quality drops drastically – starts at 60 % for RNAs in comparison to 20 % for proteins. In this study we enhance the previous benchmark. 相似文献9.
Nunzio D'Agostino Daniele Pizzichini Maria Luisa Chiusano Giovanni Giuliano 《BMC plant biology》2007,7(1):53
Background
Saffron (Crocus sativus L., Iridaceae) flowers have been used as a spice and medicinal plant ever since the Greek-Minoan civilization. The edible part – the stigmas – are commonly considered the most expensive spice in the world and are the site of a peculiar secondary metabolism, responsible for the characteristic color and flavor of saffron. 相似文献10.
Arumay Pal Ranjit Prasad Bahadur Partha Sarathi Ray Pinak Chakrabarti 《BMC bioinformatics》2009,10(1):103-10
Background
Depending on chemical features residues have preferred locations – interior or exterior – in protein structures, which also determine how many other residues are found around them. The close packing of residues is the hallmark of protein interior and protein-protein interaction sites. 相似文献11.
Background
Fungi from environmental samples are typically identified to species level through DNA sequencing of the nuclear ribosomal internal transcribed spacer (ITS) region for use in BLAST-based similarity searches in the International Nucleotide Sequence Databases. These searches are time-consuming and regularly require a significant amount of manual intervention and complementary analyses. We here present software – in the form of an identification pipeline for large sets of fungal ITS sequences – developed to automate the BLAST process and several additional analysis steps. The performance of the pipeline was evaluated on a dataset of 350 ITS sequences from fungi growing as epiphytes on building material. 相似文献12.
Background
The evolutionary rate at a given homologous position varies across time. When sufficiently pronounced, this phenomenon – called heterotachy – may produce artefactual phylogenetic reconstructions under the commonly used models of sequence evolution. These observations have motivated the development of models that explicitly recognize heterotachy, with research directions proposed along two main axes: 1) the covarion approach, where sites switch from variable to invariable states; and 2) the mixture of branch lengths (MBL) approach, where alignment patterns are assumed to arise from one of several sets of branch lengths, under a given phylogeny. 相似文献13.
Background
Detecting new coding sequences (CDSs) in viral genomes can be difficult for several reasons. The typically compact genomes often contain a number of overlapping coding and non-coding functional elements, which can result in unusual patterns of codon usage; conservation between related sequences can be difficult to interpret – especially within overlapping genes; and viruses often employ non-canonical translational mechanisms – e.g. frameshifting, stop codon read-through, leaky-scanning and internal ribosome entry sites – which can conceal potentially coding open reading frames (ORFs). 相似文献14.
Background
A major cornerstone of evolutionary biology theory is the explanation of the emergence of cooperation in communities of selfish individuals. There is an unexplained tendency in the plant and animal world – with examples from alpine plants, worms, fish, mole-rats, monkeys and humans – for cooperation to flourish where the environment is more adverse (harsher) or more unpredictable. 相似文献15.
Background
In recent years, constrained optimization – usually referred to as flux balance analysis (FBA) – has become a widely applied method for the computation of stationary fluxes in large-scale metabolic networks. The striking advantage of FBA as compared to kinetic modeling is that it basically requires only knowledge of the stoichiometry of the network. On the other hand, results of FBA are to a large degree hypothetical because the method relies on plausible but hardly provable optimality principles that are thought to govern metabolic flux distributions. 相似文献16.
Philipp N Seibel Jan Krüger Sven Hartmeier Knut Schwarzer Kai L?wenthal Henning Mersch Thomas Dandekar Robert Giegerich 《BMC bioinformatics》2006,7(1):490
Background
Today, there is a growing need in bioinformatics to combine available software tools into chains, thus building complex applications from existing single-task tools. To create such workflows, the tools involved have to be able to work with each other's data – therefore, a common set of well-defined data formats is needed. Unfortunately, current bioinformatic tools use a great variety of heterogeneous formats. 相似文献17.
18.
Background
The relationship between divergence of amino-acid sequence and divergence of function among homologous proteins is complex. The assumption that homologs share function – the basis of transfer of annotations in databases – must therefore be regarded with caution. Here, we present a quantitative study of sequence and function divergence, based on the Gene Ontology classification of function. We determined the relationship between sequence divergence and function divergence in 6828 protein families from the PFAM database. Within families there is a broad range of sequence similarity from very closely related proteins – for instance, orthologs in different mammals – to very distantly-related proteins at the limit of reliable recognition of homology. 相似文献19.
20.
Richárd Farkas 《BMC bioinformatics》2008,9(1):69