132 research outputs found

    PLANIFICACIÓN ÓPTIMA DE REDES UTILIZANDO ALGORITMOS EVOLUTIVOS

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    This article proposes using Multi- Targeted Evolutionary Algorithms for Telephone Exchange Planning, on the short, medium and long run. Experimental resuls for a city make the present proposal valuable because of the quick, varied and quality solutions obtained.El artículo propone la utilización de Algoritmos Evolutivos Multiobjetivos para la planificación de centrales telefónicas a corto, mediano y largo plazo. Los resultados experimentales para una ciudad validan la presente propuesta, por la rapidez, la variedad y la calidad de las soluciones

    Caracterización histológica y molecular de infección por Edwardsiella anguillarum en tilapia (Oreochromis niloticus) cultivada en sistema biofloc en Lima, Perú

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    The aim of this study was to isolate and characterize phenotypically and molecularly the pathogen Edwardsiella anguillarum, as well as to determine the anatomo-histopathological lesions in tilapia (Oreochromis niloticus) cultivated with biofloc technology in the northern area of Lima, Peru. Five isolated bacterial strains were isolated and characterized by conventional biochemical techniques and by the API 20E system. E. anguillarum was identified from internal organs using biochemical and molecular techniques. The most frequent external clinical signs were bilateral exophthalmia, erythema in the pectoral fins and around the anus. Internally, whitish nodules in the heart and liver were observed. The histopathological study revealed necrosis in the branchial lamellae, spleen, intestine, posterior kidney and gonad, as well as the presence of an inflammatory reaction of granulomatous type in the heart, liver, spleen, kidney and gonads. The strains showed fermentative glucose metabolism and positivity to methyl red, production of hydrogen sulphide, indole and acid production from mannitol. The isolates were confirmed by the PCR technique and sequencing of the 16S rRNA gene. All the strains showed sensitivity to the antibiotics nalidixic acid, florfenicol, gentamicin, kanamycin, flumequine, oxytetracycline and trimethoprim sulfamethoxazole.El objetivo del estudio fue aislar y caracterizar fenotípica y molecularmente al patógeno Edwardsiella anguillarum, así como determinar las lesiones anatomo-histopatológicas en tilapia (Oreochromis niloticus) cultivada con tecnología biofloc en la zona norte de Lima, Perú. Se trabajó con cinco cepas bacterianas aisladas y caracterizadas mediante técnicas bioquímicas convencionales y por el sistema API 20E. Se identificó E. anguillarum a partir de órganos internos mediante las técnicas bioquímica y molecular. Los signos clínicos externos más frecuentes fueron exoftalmia bilateral, eritema en aletas pectorales y alrededor del ano. Internamente se apreció nodulaciones blanquecinas en el corazón e hígado. El estudio histopatológico reveló necrosis en lamelas branquiales, bazo, intestino, riñón posterior y gónada, así como presencia de reacción inflamatoria de tipo granulomatosa en corazón, hígado, bazo, riñón y gónadas. Las cepas evaluadas presentaron metabolismo fermentativo de glucosa y positividad ante las pruebas de rojo de metilo, producción de sulfuro de hidrógeno, indol y ácido a partir de manitol. Los aislados fueron confirmados por la técnica de PCR y secuenciación del gen 16S ARNr. Todas las cepas presentaron sensibilidad a los antibióticos ácido nalidíxico, florfenicol, gentamicina, kanamicina, flumequina, oxitetraciclina y sulfatrimetoprim

    Systematic Characterizations of Text Similarity in Full Text Biomedical Publications

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    Computational methods have been used to find duplicate biomedical publications in MEDLINE. Full text articles are becoming increasingly available, yet the similarities among them have not been systematically studied. Here, we quantitatively investigated the full text similarity of biomedical publications in PubMed Central.72,011 full text articles from PubMed Central (PMC) were parsed to generate three different datasets: full texts, sections, and paragraphs. Text similarity comparisons were performed on these datasets using the text similarity algorithm eTBLAST. We measured the frequency of similar text pairs and compared it among different datasets. We found that high abstract similarity can be used to predict high full text similarity with a specificity of 20.1% (95% CI [17.3%, 23.1%]) and sensitivity of 99.999%. Abstract similarity and full text similarity have a moderate correlation (Pearson correlation coefficient: -0.423) when the similarity ratio is above 0.4. Among pairs of articles in PMC, method sections are found to be the most repetitive (frequency of similar pairs, methods: 0.029, introduction: 0.0076, results: 0.0043). In contrast, among a set of manually verified duplicate articles, results are the most repetitive sections (frequency of similar pairs, results: 0.94, methods: 0.89, introduction: 0.82). Repetition of introduction and methods sections is more likely to be committed by the same authors (odds of a highly similar pair having at least one shared author, introduction: 2.31, methods: 1.83, results: 1.03). There is also significantly more similarity in pairs of review articles than in pairs containing one review and one nonreview paper (frequency of similar pairs: 0.0167 and 0.0023, respectively).While quantifying abstract similarity is an effective approach for finding duplicate citations, a comprehensive full text analysis is necessary to uncover all potential duplicate citations in the scientific literature and is helpful when establishing ethical guidelines for scientific publications

    Comprehensive Overview of Bottom-up Proteomics using Mass Spectrometry

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    Proteomics is the large scale study of protein structure and function from biological systems through protein identification and quantification. "Shotgun proteomics" or "bottom-up proteomics" is the prevailing strategy, in which proteins are hydrolyzed into peptides that are analyzed by mass spectrometry. Proteomics studies can be applied to diverse studies ranging from simple protein identification to studies of proteoforms, protein-protein interactions, protein structural alterations, absolute and relative protein quantification, post-translational modifications, and protein stability. To enable this range of different experiments, there are diverse strategies for proteome analysis. The nuances of how proteomic workflows differ may be challenging to understand for new practitioners. Here, we provide a comprehensive overview of different proteomics methods to aid the novice and experienced researcher. We cover from biochemistry basics and protein extraction to biological interpretation and orthogonal validation. We expect this work to serve as a basic resource for new practitioners in the field of shotgun or bottom-up proteomics

    Genetic diversity of human sapovirus across the Americas

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    Background: Sapoviruses are responsible for sporadic and epidemic acute gastroenteritis worldwide. Sapovirus typing protocols have a success rate as low as 43% and relatively few complete sapovirus genome sequences are available to improve current typing protocols. Objective/study design: To increase the number of complete sapovirus genomes to better understand the molecular epidemiology of human sapovirus and to improve the success rate of current sapovirus typing methods, we used deep metagenomics shotgun sequencing to obtain the complete genomes of 68 sapovirus samples from four different countries across the Americas (Guatemala, Nicaragua, Peru and the US). Results: VP1 genotyping showed that all sapovirus sequences could be grouped in the four established genogroups (GI (n = 13), GII (n = 30), GIV (n = 23), GV (n = 2)) that infect humans. They include the near-complete genome of a GI.6 virus and a recently reported novel GII.8 virus. Sequences of the complete RNA-dependent RNA polymerase gene could be grouped into three major genetic clusters or polymerase (P) types (GI.P, GII.P and GV.P) with all GIV viruses harboring a GII polymerase. One (GII.P-GII.4) of the new 68 sequences was a recombinant virus with the hotspot between the NS7 and VP1 regions. Conclusions: Analyses of this expanded database of near-complete sapovirus sequences showed several mismatches in the genotyping primers, suggesting opportunities to revisit and update current sapovirus typing methods

    Analyses of an Expressed Sequence Tag Library from Taenia solium, Cysticerca

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    A method used to describe expressed genes at a specific stage in an organism is an EST library. In this method mRNA from a specific organism is isolated, transcribed into cDNA and sequenced. The sequence will derive from the 5′-end of the cDNA. The library will not have sequences from all genes, especially if they are expressed in low amounts or not at all in the studied stage. Also the library will mostly not contain full length sequences from genes, but expression patterns can be established. If EST libraries are made from different stages of the same organisms these libraries can be compared and differently expressed genes can be identified. Described here is an analysis of an EST library from the pig cysticerca which is thought to be similar to the stage giving the human neglected disease neurocysticercosis. Novel genes together with putative drug targets are examples of data presented

    Polyclonal antibodies for the detection of Trypanosoma cruzi circulating antigens

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    Detection of Trypanosoma cruzi antigens in clinical samples is considered an important diagnostic tool for Chagas disease. The production and use of polyclonal antibodies may contribute to an increase in the sensitivity of immunodiagnosis of Chagas disease.Polyclonal antibodies were raised in alpacas, rabbits, and hens immunized with trypomastigote excreted-secreted antigen, membrane proteins, trypomastigote lysate antigen and recombinant 1F8 to produce polyclonal antibodies. Western blot analysis was performed to determine specificity of the developed antibodies. An antigen capture ELISA of circulating antigens in serum, plasma and urine samples was developed using IgY polyclonal antibodies against T. cruzi membrane antigens (capture antibody) and IgG from alpaca raised against TESA. A total of 33 serum, 23 plasma and 9 urine samples were analyzed using the developed test. Among serum samples, compared to serology, the antigen capture ELISA tested positive in 55% of samples. All plasma samples from serology positive subjects were positive in the antigen capture ELISA. All urine positive samples had corresponding plasma samples that were also positive when tested by the antigen capture ELISA.Polyclonal antibodies are useful for detection of circulating antigens in both the plasma and urine of infected individuals. Detection of antigens is direct evidence of the presence of the parasite, and could be a better surrogate of current infection status
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