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1.
F1000Res ; 12: 1300, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38046194

RESUMO

Background: This systematic literature review (SLR) analyzes migrant entrepreneurship support in Europe through three research questions (RQs) to understand 1) migrant entrepreneur characteristics in the European context, 2) challenges encountered by migrant entrepreneurs in European host countries, and 3) policies supporting migrant entrepreneurship in Europe. This review addresses gaps in current knowledge in academia as well as issues that policymakers and practitioners face when addressing migrant entrepreneurship support. Methods: This SLR employed a search protocol to retrieve published sources from 1970 to 2021, via Scopus (27 March 2022) and Web of Science (7 April 2022). Inclusion criteria targeted migrant entrepreneurship support studies while exclusion criteria eliminated domestic migration and non-European contexts. The authors worked iteratively, aligning the data with the RQs to reduce bias, and adapted Bourdieu's forms of capital to create an analytical framework for the sources included in the SLR, with a table for each RQ to synthesize relevant data for analysis. Results: The review examined 91 peer-reviewed papers, with a focus on migrant entrepreneurship support in Europe, covering characteristics, challenges, and support policies. It classified migrant entrepreneur challenges and characteristics into financial, human, and social capital, as well as external factors. Common challenges include the local culture and language, network, funding, and adapting to local business practices. Migrant entrepreneurs' stability relates to time in the host country and local language proficiency and reflects past entrepreneurial experience and education. Supportive mechanisms involve local networks, financing, and mentoring. Conclusions: The SLR's limitations encompass possible oversight of pertinent studies, along with potential bias in data extraction, analysis, and subjectivity due to thematic analysis. Nonetheless, the findings suggest the following research agenda for migrant entrepreneurship support: evaluating and enhancing human and social capital, sharing information, designing support programs, addressing in-group/out-group bias in support programs, and exploring bottom-up migrant entrepreneurship support approaches.


Assuntos
Migrantes , Humanos , Empreendedorismo , Europa (Continente) , Escolaridade
2.
Int J Cancer ; 153(10): 1819-1828, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37551617

RESUMO

Genome-scale screening experiments in cancer produce long lists of candidate genes that require extensive interpretation for biological insight and prioritization for follow-up studies. Interrogation of gene lists frequently represents a significant and time-consuming undertaking, in which experimental biologists typically combine results from a variety of bioinformatics resources in an attempt to portray and understand cancer relevance. As a means to simplify and strengthen the support for this endeavor, we have developed oncoEnrichR, a flexible bioinformatics tool that allows cancer researchers to comprehensively interrogate a given gene list along multiple facets of cancer relevance. oncoEnrichR differs from general gene set analysis frameworks through the integration of an extensive set of prior knowledge specifically relevant for cancer, including ranked gene-tumor type associations, literature-supported proto-oncogene and tumor suppressor gene annotations, target druggability data, regulatory interactions, synthetic lethality predictions, as well as prognostic associations, gene aberrations and co-expression patterns across tumor types. The software produces a structured and user-friendly analysis report as its main output, where versions of all underlying data resources are explicitly logged, the latter being a critical component for reproducible science. We demonstrate the usefulness of oncoEnrichR through interrogation of two candidate lists from proteomic and CRISPR screens. oncoEnrichR is freely available as a web-based service hosted by the Galaxy platform (https://oncotools.elixir.no), and can also be accessed as a stand-alone R package (https://github.com/sigven/oncoEnrichR).


Assuntos
Neoplasias , Proteômica , Humanos , Biologia Computacional/métodos , Software , Neoplasias/genética
3.
Nat Commun ; 13(1): 1667, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35351890

RESUMO

Resistance to EGFR inhibitors (EGFRi) presents a major obstacle in treating non-small cell lung cancer (NSCLC). One of the most exciting new ways to find potential resistance markers involves running functional genetic screens, such as CRISPR, followed by manual triage of significantly enriched genes. This triage process to identify 'high value' hits resulting from the CRISPR screen involves manual curation that requires specialized knowledge and can take even experts several months to comprehensively complete. To find key drivers of resistance faster we build a recommendation system on top of a heterogeneous biomedical knowledge graph integrating pre-clinical, clinical, and literature evidence. The recommender system ranks genes based on trade-offs between diverse types of evidence linking them to potential mechanisms of EGFRi resistance. This unbiased approach identifies 57 resistance markers from >3,000 genes, reducing hit identification time from months to minutes. In addition to reproducing known resistance markers, our method identifies previously unexplored resistance mechanisms that we prospectively validate.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/genética , Receptores ErbB/metabolismo , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Mutação , Reconhecimento Automatizado de Padrão , Inibidores de Proteínas Quinases/farmacologia
4.
PLoS Comput Biol ; 15(8): e1006940, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31449516

RESUMO

Conserved Noncoding Elements (CNEs) are elements exhibiting extreme noncoding conservation in Metazoan genomes. They cluster around developmental genes and act as long-range enhancers, yet nothing that we know about their function explains the observed conservation levels. Clusters of CNEs coincide with topologically associating domains (TADs), indicating ancient origins and stability of TAD locations. This has suggested further hypotheses about the still elusive origin of CNEs, and has provided a comparative genomics-based method of estimating the position of TADs around developmentally regulated genes in genomes where chromatin conformation capture data is missing. To enable researchers in gene regulation and chromatin biology to start deciphering this phenomenon, we developed CNEr, a R/Bioconductor toolkit for large-scale identification of CNEs and for studying their genomic properties. We apply CNEr to two novel genome comparisons-fruit fly vs tsetse fly, and two sea urchin genomes-and report novel insights gained from their analysis. We also show how to reveal interesting characteristics of CNEs by coupling CNEr with existing Bioconductor packages. CNEr is available at Bioconductor (https://bioconductor.org/packages/CNEr/) and maintained at github (https://github.com/ge11232002/CNEr).


Assuntos
Sequência Conservada , Software , Algoritmos , Animais , Biologia Computacional , Bases de Dados Genéticas , Drosophila/genética , Genoma , Genômica/estatística & dados numéricos , Humanos , Modelos Genéticos , RNA não Traduzido/genética , Ouriços-do-Mar/genética , Moscas Tsé-Tsé/genética
5.
Sci Rep ; 9(1): 1700, 2019 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-30737442

RESUMO

Analysis of DNA composition at several length scales constitutes the bulk of many early studies aimed at unravelling the complexity of the organization and functionality of genomes. Dinucleotide relative abundances are considered an idiosyncratic feature of genomes, regarded as a 'genomic signature'. Motivated by this finding, we introduce the 'Generalized Genomic Signatures' (GGSs), composed of over- and under-abundances of all oligonucleotides of a given length, thus filtering out compositional trends and neighbour preferences at any shorter range. Previous works on alignment-free genomic comparisons mostly rely on k-mer frequencies and not on distance-dependent neighbour preferences. Therein, nucleotide composition and proximity preferences are combined, while in the present work they are strictly separated, focusing uniquely on neighbour relationships. GGSs retain the potential or even outperform genomic signatures defined at the dinucleotide level in distinguishing between taxonomic subdivisions of bacteria, and can be more effectively implemented in microbial phylogenetic reconstruction. Moreover, we compare DNA sequences from the human genome corresponding to protein coding segments, conserved non-coding elements and non-functional DNA stretches. These classes of sequences have distinctive GGSs according to their genomic role and degree of conservation. Overall, GGSs constitute a trait characteristic of the evolutionary origin and functionality of different genomic segments.


Assuntos
Bactérias/classificação , Genômica/métodos , Análise de Sequência de DNA/métodos , Animais , Bactérias/genética , Sequência de Bases , Sequência Conservada , DNA/genética , Evolução Molecular , Humanos , Filogenia , RNA não Traduzido/genética
6.
Bioinformatics ; 34(17): i743-i747, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30423090

RESUMO

Motivation: Conserved non-coding elements (CNEs) represent an enigmatic class of genomic elements which, despite being extremely conserved across evolution, do not encode for proteins. Their functions are still largely unknown. Thus, there exists a need to systematically investigate their roles in genomes. Towards this direction, identifying sets of CNEs in a wide range of organisms is an important first step. Currently, there are no tools published in the literature for systematically identifying CNEs in genomes. Results: We fill this gap by presenting CNEFinder; a tool for identifying CNEs between two given DNA sequences with user-defined criteria. The results presented here show the tool's ability of identifying CNEs accurately and efficiently. CNEFinder is based on a k-mer technique for computing maximal exact matches. The tool thus does not require or compute whole-genome alignments or indexes, such as the suffix array or the Burrows Wheeler Transform (BWT), which makes it flexible to use on a wide scale. Availability and implementation: Free software under the terms of the GNU GPL (https://github.com/lorrainea/CNEFinder).


Assuntos
Genoma , RNA não Traduzido/genética , Análise de Sequência/métodos , Software , Sequência Conservada/genética , Humanos
7.
Nucleic Acids Res ; 45(22): 12611-12624, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-29121339

RESUMO

Comparative genomics has revealed a class of non-protein-coding genomic sequences that display an extraordinary degree of conservation between two or more organisms, regularly exceeding that found within protein-coding exons. These elements, collectively referred to as conserved non-coding elements (CNEs), are non-randomly distributed across chromosomes and tend to cluster in the vicinity of genes with regulatory roles in multicellular development and differentiation. CNEs are organized into functional ensembles called genomic regulatory blocks-dense clusters of elements that collectively coordinate the expression of shared target genes, and whose span in many cases coincides with topologically associated domains. CNEs display sequence properties that set them apart from other sequences under constraint, and have recently been proposed as useful markers for the reconstruction of the evolutionary history of organisms. Disruption of several of these elements is known to contribute to diseases linked with development, and cancer. The emergence, evolutionary dynamics and functions of CNEs still remain poorly understood, and new approaches are required to enable comprehensive CNE identification and characterization. Here, we review current knowledge and identify challenges that need to be tackled to resolve the impasse in understanding extreme non-coding conservation.


Assuntos
Sequência Conservada/genética , Regulação da Expressão Gênica no Desenvolvimento , Genoma/genética , Sequências Reguladoras de Ácido Nucleico/genética , Animais , Sequência de Bases , Evolução Molecular , Genes Controladores do Desenvolvimento/genética , Humanos , Homologia de Sequência do Ácido Nucleico
8.
Algorithms Mol Biol ; 12: 5, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28293277

RESUMO

BACKGROUND: The deviation of the observed frequency of a word w from its expected frequency in a given sequence x is used to determine whether or not the word is avoided. This concept is particularly useful in DNA linguistic analysis. The value of the deviation of w, denoted by [Formula: see text], effectively characterises the extent of a word by its edge contrast in the context in which it occurs. A word w of length [Formula: see text] is a [Formula: see text]-avoided word in x if [Formula: see text], for a given threshold [Formula: see text]. Notice that such a word may be completely absent from x. Hence, computing all such words naïvely can be a very time-consuming procedure, in particular for large k. RESULTS: In this article, we propose an [Formula: see text]-time and [Formula: see text]-space algorithm to compute all [Formula: see text]-avoided words of length k in a given sequence of length n over a fixed-sized alphabet. We also present a time-optimal [Formula: see text]-time algorithm to compute all [Formula: see text]-avoided words (of any length) in a sequence of length n over an integer alphabet of size [Formula: see text]. In addition, we provide a tight asymptotic upper bound for the number of [Formula: see text]-avoided words over an integer alphabet and the expected length of the longest one. We make available an implementation of our algorithm. Experimental results, using both real and synthetic data, show the efficiency and applicability of our implementation in biological sequence analysis. CONCLUSIONS: The systematic search for avoided words is particularly useful for biological sequence analysis. We present a linear-time and linear-space algorithm for the computation of avoided words of length k in a given sequence x. We suggest a modification to this algorithm so that it computes all avoided words of x, irrespective of their length, within the same time complexity. We also present combinatorial results with regards to avoided words and absent words.

9.
Gene ; 584(2): 148-60, 2016 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-26899868

RESUMO

Conserved non-coding elements (CNEs) are defined using various degrees of sequence identity and thresholds of minimal length. Their conservation frequently exceeds the one observed for protein-coding sequences. We explored the chromosomal distribution of different classes of CNEs in the human genome. We employed two methodologies: the scaling of block entropy and box-counting, with the aim to assess fractal characteristics of different CNE datasets. Both approaches converged to the conclusion that well-developed fractality is characteristic of elements that are either extremely conserved between species or are of ancient origin, i.e. conserved between distant organisms across evolution. Given that CNEs are often clustered around genes, we verified by appropriate gene masking that fractal-like patterns emerge even when elements found in proximity or inside genes are excluded. An evolutionary scenario is proposed, involving genomic events that might account for fractal distribution of CNEs in the human genome as indicated through numerical simulations.


Assuntos
Cromossomos Humanos , Entropia , Fractais , Genoma Humano , Humanos
10.
BMC Bioinformatics ; 16: 138, 2015 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-25925131

RESUMO

BACKGROUND: This article provides an overview of the first BIOASQ challenge, a competition on large-scale biomedical semantic indexing and question answering (QA), which took place between March and September 2013. BIOASQ assesses the ability of systems to semantically index very large numbers of biomedical scientific articles, and to return concise and user-understandable answers to given natural language questions by combining information from biomedical articles and ontologies. RESULTS: The 2013 BIOASQ competition comprised two tasks, Task 1a and Task 1b. In Task 1a participants were asked to automatically annotate new PUBMED documents with MESH headings. Twelve teams participated in Task 1a, with a total of 46 system runs submitted, and one of the teams performing consistently better than the MTI indexer used by NLM to suggest MESH headings to curators. Task 1b used benchmark datasets containing 29 development and 282 test English questions, along with gold standard (reference) answers, prepared by a team of biomedical experts from around Europe and participants had to automatically produce answers. Three teams participated in Task 1b, with 11 system runs. The BIOASQ infrastructure, including benchmark datasets, evaluation mechanisms, and the results of the participants and baseline methods, is publicly available. CONCLUSIONS: A publicly available evaluation infrastructure for biomedical semantic indexing and QA has been developed, which includes benchmark datasets, and can be used to evaluate systems that: assign MESH headings to published articles or to English questions; retrieve relevant RDF triples from ontologies, relevant articles and snippets from PUBMED Central; produce "exact" and paragraph-sized "ideal" answers (summaries). The results of the systems that participated in the 2013 BIOASQ competition are promising. In Task 1a one of the systems performed consistently better from the NLM's MTI indexer. In Task 1b the systems received high scores in the manual evaluation of the "ideal" answers; hence, they produced high quality summaries as answers. Overall, BIOASQ helped obtain a unified view of how techniques from text classification, semantic indexing, document and passage retrieval, question answering, and text summarization can be combined to allow biomedical experts to obtain concise, user-understandable answers to questions reflecting their real information needs.


Assuntos
Indexação e Redação de Resumos/métodos , Algoritmos , Medical Subject Headings , Processamento de Linguagem Natural , PubMed , Semântica , Software , Humanos , National Library of Medicine (U.S.) , Estados Unidos
11.
Genomics ; 104(2): 79-86, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25058025

RESUMO

Scarce work has been done in the analysis of the composition of conserved non-coding elements (CNEs) that are identified by comparisons of two or more genomes and are found to exist in all metazoan genomes. Here we present the analysis of CNEs with a methodology that takes into account word occurrence at various lengths scales in the form of feature vector representation and rule based classifiers. We implement our approach on both protein-coding exons and CNEs, originating from human, insect (Drosophila melanogaster) and worm (Caenorhabditis elegans) genomes, that are either identified in the present study or obtained from the literature. Alignment free feature vector representation of sequences combined with rule-based classification methods leads to successful classification of the different CNEs classes. Biologically meaningful results are derived by comparison with the genomic signatures approach, and classification rates for a variety of functional elements of the genomes along with surrogates are presented.


Assuntos
Caenorhabditis elegans/genética , DNA Intergênico/genética , Drosophila melanogaster/genética , Análise de Sequência de DNA/métodos , Animais , Sequência Conservada/genética , Evolução Molecular , Éxons , Genômica , Humanos , Alinhamento de Sequência
12.
PLoS One ; 9(5): e95437, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24787386

RESUMO

Conserved, ultraconserved and other classes of constrained elements (collectively referred as CNEs here), identified by comparative genomics in a wide variety of genomes, are non-randomly distributed across chromosomes. These elements are defined using various degrees of conservation between organisms and several thresholds of minimal length. We here investigate the chromosomal distribution of CNEs by studying the statistical properties of distances between consecutive CNEs. We find widespread power-law-like distributions, i.e. linearity in double logarithmic scale, in the inter-CNE distances, a feature which is connected with fractality and self-similarity. Given that CNEs are often found to be spatially associated with genes, especially with those that regulate developmental processes, we verify by appropriate gene masking that a power-law-like pattern emerges irrespectively of whether elements found close or inside genes are excluded or not. An evolutionary model is put forward for the understanding of these findings that includes segmental or whole genome duplication events and eliminations (loss) of most of the duplicated CNEs. Simulations reproduce the main features of the observed size distributions. Power-law-like patterns in the genomic distributions of CNEs are in accordance with current knowledge about their evolutionary history in several genomes.


Assuntos
Sequência Conservada , Genômica , Modelos Genéticos , Animais , Cromossomos Humanos/genética , Evolução Molecular , Genoma Humano/genética , Humanos
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