44 research outputs found
Modelamiento y Simulación de Redes de Transporte Urbano: Seis Casos en Lima
Studies of urban transport networks in many cities are not well focused, since they do not include tools for their planning and control, making decisions to solve the multiple problems regarding traffic congestion expensive and not adequate, generating discomfort in the users, and many times it aggravates the problems, since its impact is not evaluated. Currently exist a variety of simulators that are helpful for traffic simulation and online monitoring. An alternative to this are traffic simulators, which currently exist in variety, however, they are not easily accessible, a formal study and a relationship with the research center that provides it is required, their personalized reports are limited and they comply to another reality. In the present work, six frequent cases of urban transport networks in Lima are modeled, simulated and validated: intersection, oval, union, by-pass, clover and T; by using Arena (general-purpose simulator), known statistical and simulation techniques. The T model was validated with an average confidence level of 95%, in addition, personalized information could be obtained for decision making.Los estudios de las redes de transporte urbano en muchas ciudades no están bien enfocados, pues no contemplan herramientas para su planificación y control, haciendo que las decisiones para solucionar los múltiples problemas respecto a la congestión vehicular sean caros y no adecuadas, generando malestar en los usuarios, y muchas veces agrava los problemas, pues no se evalúa su impacto. Una alternativa a ello son los simuladores de tráfico, que en la actualidad existen en variedad, sin embargo, no son de fácil acceso, se requiere un estudio formal y una relación con el centro de investigación que lo provee, sus reportes personalizados son limitados y obedecen a otra realidad. En el presente trabajo se modela, simula seis casos frecuentes de redes de transporte urbano en Lima: Intersección, Ovalo, Unión, By-Pass, Trébol y T; mediante el uso de Arena (simulador de propósito general), técnicas estadísticas y de simulación conocidas. Se validó el modelo T con un nivel de confianza promedio del 95%, además, se pudo obtener información personalizada para la toma de decisión
Genetic diversity and population structure in Physalis peruviana and related taxa based on InDels and SNPs derived from COSII and IRG markers
AbstractThe genus Physalis is common in the Americas and includes several economically important species, among them is Physalis peruviana that produces appetizing edible fruits. We studied the genetic diversity and population structure of P. peruviana and characterized 47 accessions of this species along with 13 accessions of related taxa consisting of 222 individuals from the Colombian Corporation of Agricultural Research (CORPOICA) germplasm collection, using Conserved Orthologous Sequences (COSII) and Immunity Related Genes (IRGs). In addition, 642 Single Nucleotide Polymorphism (SNP) markers were identified and used for the genetic diversity analysis. A total of 121 alleles were detected in 24 InDels loci ranging from 2 to 9 alleles per locus, with an average of 5.04 alleles per locus. The average number of alleles in the SNP markers was two. The observed heterozygosity for P. peruviana with InDel and SNP markers was higher (0.48 and 0.59) than the expected heterozygosity (0.30 and 0.41). Interestingly, the observed heterozygosity in related taxa (0.4 and 0.12) was lower than the expected heterozygosity (0.59 and 0.25). The coefficient of population differentiation FST was 0.143 (InDels) and 0.038 (SNPs), showing a relatively low level of genetic differentiation among P. peruviana and related taxa. Higher levels of genetic variation were instead observed within populations based on the AMOVA analysis. Population structure analysis supported the presence of two main groups and PCA analysis based on SNP markers revealed two distinct clusters in the P. peruviana accessions corresponding to their state of cultivation. In this study, we identified molecular markers useful to detect genetic variation in Physalis germplasm for assisting conservation and crossbreeding strategies
Zerovalent bismuth nanoparticles inhibit Streptococcus mutans growth and formation of biofilm
Background and methods: Despite continuous efforts, the increasing prevalence of resistance among pathogenic bacteria to common antibiotics has become one of the most significant concerns in modern medicine. Nanostructured materials are used in many fields, including biological sciences and medicine. While some bismuth derivatives has been used in medicine to treat vomiting, nausea, diarrhea, and stomach pain, the biocidal activity of zerovalent bismuth nanoparticles has not yet been studied. The objective of this investigation was to analyze the antimicrobial activity of bismuth nanoparticles against oral bacteria and their antibiofilm capabilities. Results: Our results showed that stable colloidal bismuth nanoparticles had 69% antimicrobial activity against Streptococcus mutans growth and achieved complete inhibition of biofilm formation. These results are similar to those obtained with chlorhexidine, the most commonly used oral antiseptic agent. The minimal inhibitory concentration of bismuth nanoparticles that interfered with S. mutans growth was 0.5 mM. Conclusion: These results suggest that zerovalent bismuth nanoparticles could be an interesting antimicrobial agent to be incorporated into an oral antiseptic preparation
The Role of Practice Research Networks (PRN) in the Development and Implementation of Evidence: The Northern Improving Access to Psychological Therapies PRN Case Study
Practice research networks (PRNs) can support the implementation of evidence based practice in routine services and generate practice based evidence. This paper describes the structure, processes and learning from a new PRN in the Improving Access to Psychological Therapies programme in England, in relation to an implementation framework and using one study as a case example. Challenges related to: ethics and governance processes; communications with multiple stakeholders; competing time pressures and linking outcome data. Enablers included: early tangible outputs and impact; a collaborative approach; engaging with local research leads; clarity of processes; effective dissemination; and committed leadership
Positive relationships between association strength and phenotypic similarity characterize the assembly of mixed-species bird flocks worldwide
Competition theory predicts that local communities should consist of species that are more dissimilar than expected by chance. We find a strikingly different pattern in a multicontinent data set (55 presence-absence matrices from 24 locations) on the composition of mixed-species bird flocks, which are important sub-units of local bird communities the world over. By using null models and randomization tests followed by meta-analysis, we find the association strengths of species in flocks to be strongly related to similarity in body size and foraging behavior and higher for congeneric compared with noncongeneric species pairs. Given the local spatial scales of our individual analyses, differences in the habitat preferences of species are unlikely to have caused these association patterns; the patterns observed are most likely the outcome of species interactions. Extending group-living and social-information-use theory to a heterospecific context, we discuss potential behavioral mechanisms that lead to positive interactions among similar species in flocks, as well as ways in which competition costs are reduced. Our findings highlight the need to consider positive interactions along with competition when seeking to explain community assembly
Live Imaging of Mitosomes and Hydrogenosomes by HaloTag Technology
Hydrogenosomes and mitosomes represent remarkable mitochondrial adaptations in the anaerobic parasitic protists such as Trichomonas vaginalis and Giardia intestinalis, respectively. In order to provide a tool to study these organelles in the live cells, the HaloTag was fused to G. intestinalis IscU and T. vaginalis frataxin and expressed in the mitosomes and hydrogenosomes, respectively. The incubation of the parasites with the fluorescent Halo-ligand resulted in highly specific organellar labeling, allowing live imaging of the organelles. With the array of available ligands the HaloTag technology offers a new tool to study the dynamics of mitochondria-related compartments as well as other cellular components in these intriguing unicellular eukaryotes
The Relationship Between Therapist Effects and Therapy Delivery Factors: Therapy Modality, Dosage, and Non-completion.
To consider the relationships between, therapist variability, therapy modality, therapeutic dose and therapy ending type and assess their effects on the variability of patient outcomes. Multilevel modeling was used to analyse a large sample of routinely collected data. Model residuals identified more and less effective therapists, controlling for case-mix. After controlling for case mix, 5.8 % of the variance in outcome was due to therapists. More sessions generally improved outcomes, by about half a point on the PHQ-9 for each additional session, while non-completion of therapy reduced the amount of pre-post change by six points. Therapy modality had little effect on outcome. Patient and service outcomes may be improved by greater focus on the variability between therapists and in keeping patients in therapy to completion
Positive Relationships between Association Strength and Phenotypic Similarity Characterize the Assembly of Mixed-Species Bird Flocks Worldwide
Consenso Mexicano de Hepatitis Alcohólica
La hepatitis alcohólica es una condición frecuente en la población mexicana, se
caracteriza por insuficiencia hepática aguda sobre crónica, importante reacción inflamatoria
sistémica y fallo multiorgánico, que en la variante grave de la enfermedad implica una elevada
mortalidad. Por lo anterior, la Asociación Mexicana de Gastroenterología y la Asociación Mexicana
de Hepatología conjuntaron un equipo multidisciplinario de profesionales de la salud para
elaborar el primer consenso mexicano de hepatitis alcohólica. El consenso fue elaborado con la
metodología Delphi, emitiendo 37 recomendaciones. La enfermedad hepática relacionada con
el consumo de alcohol comprende un amplio espectro, que incluye esteatosis, esteatohepatitis,
fibrosis en diferentes grados, cirrosis y sus complicaciones. La hepatitis alcohólica grave se
define por una función modificada de Maddrey
≥
32 o por un puntaje de MELD (Model for End-
Stage Liver Disease) igual o mayor a 21. Actualmente no existe un biomarcador específico para el diagnóstico. La presencia de leucocitosis con neutrofilia, hiperbilirrubinemia (> 3 mg/dL),AST > 50 U/L ( 1.5-2 pueden orientar al diagnóstico. La piedraangular del tratamiento es la abstiencia junto con el soporte nutricional. Los esteroides estanindicados en la forma grave, en donde han resultado efectivos para reducir la mortalidad a28 días. El trasplante hepático es en la actualidad la única opción con que se cuenta parasalvar la vida de pacientes que no responden a los esteroides. Ciertos fármacos, como la N-acetilcisteína, el factor estimulante de colonias de granulocitos y la metadoxina, pueden seruna terapia adyuvante que puede mejorar la supervivencia de los pacientes
The Mexican consensus on alcoholic hepatitis
Alcoholic hepatitis is a frequent condition in the Mexican population. It is characterized
by acute-on-chronic liver failure, important systemic inflammatory response, and
multiple organ failure. The severe variant of the disease implies elevated mortality. Therefore,
the Asociación Mexicana de Gastroenterología and the Asociación Mexicana de Hepatología
brought together a multidisciplinary team of health professionals to formulate the first Mexican consensus on alcoholic hepatitis, carried out utilizing the Delphi method and resultingin 37 recommendations. Alcohol-related liver disease covers a broad spectrum of patholo-gies that includes steatosis, steatohepatitis, different grades of fibrosis, and cirrhosis and itscomplications. Severe alcoholic hepatitis is defined by a modified Maddrey’s discriminant func-tion score ≥ 32 or by a Model for End-Stage Liver Disease (MELD) score equal to or above 21.There is currently no specific biomarker for its diagnosis. Leukocytosis with neutrophilia, hyper-bilirubinemia (>3 mg/dl), AST > 50 U/l ( 1.5-2 can guide thediagnosis. Abstinence from alcohol, together with nutritional support, is the cornerstone oftreatment. Steroids are indicated for severe disease and have been effective in reducing the28-day mortality rate. At present, liver transplantation is the only life-saving option for patientsthat are nonresponders to steroids. Certain drugs, such as N-acetylcysteine, granulocyte-colonystimulating factor, and metadoxine, can be adjuvant therapies with a positive impact on patientsurvival