727 research outputs found

    Aportaciones en Ciencias Agronómicas y Ambientales

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    de investigadores e investigadores independientes. En ese sentido, queremos otorgar un reconocimiento a quienes tuvieron la voluntad y el tino de apoyar esta iniciativa sobre trabajos relacionados con la quimica, biología, agronomía y medio ambiente

    Aportaciones en Matemáticas y Química

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    Presenta una serie de trabajos de investigación sobre el título de este libro: El estudio de fenómenos naturales por medio de datos, trae a colación un conjunto de acciones y procedimientos matemáticos que a veces usamos o abusamos de las restricciones no solo de las técnicas de regresión lineal sino también de las no lineales. para la dieta del mexicano. No obstante, el consumo per cápita se ha reducido de 18 kg a menos de 8.5 kg. Puesto que en las últimas décadas, la producción nacional ha disminuido, entre otras causas debido a la reducción de la superficie agrícola por la urbanización, lo cual margina la producción a regiones con condiciones limitantes para la agricultura; lo no atractivo que ha sido trabajar el campo, los siniestros ocasionados por las condiciones naturales (sequías, inundación, heladas tempranas, etc.) que reducen o hacen nulo el rendimiento. Así como Saber cuánto fertilizante se va a aplicar a un cultivo, ha sido desde la aparición de los fertilizantes artificiales o sales inorgánicas una pregunta que los productores hacen a los técnicos agrícolas. Estos responden usando su experiencia y los resultados de los ya muchísimos experimentos de dosis de nutrimentos de muchos cultivos a la fecha. Se han destacado como importantes para determinar la cantidad de nutrimentos que un cultivo necesita: el tipo de cultivo, las temperaturas, la cantidad de agua disponible (temporal o riego), la textura del suelo y su origen y el contenido de nutrimentos. También otros factores son importantes: la pendiente, la distribución de la precipitación durante el ciclo, la cantidad de luz, etc. Entre otros

    The agenda of the institutionalist administration: Specification of a digital model of entrepreneurship

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    Resumen: Antecedentes. Los estudios del institucionalismo educativo advierten; 1) la administración de una cultura y liderazgo tradicional como eje rector de los programas académicos; 2) el establecimiento de una agenda centrada en la gestión del conocimiento, el emprendimiento y la innovación; 3) las alianzas estratégicas entre universidades y empresas como eje central de la formación profesional; 4) las redes colaborativas multidisciplinares. Objetivo. Especificar un modelo para la investigación del emprendimiento digital. Método. Se llevó a cabo un estudio no experimental, transversal y exploratorio con una selección no probabilística de fuentes indexadas en repositorios de la UNAM y UAEMEX. Resultados. La especificación del modelo incluye cinco hipótesis explicativas de las trayectorias de relaciones de dependencia entre ocho variables ?creencias, valores, percepciones, conocimientos, motivos, actitudes, intenciones y comportamiento. Discusión. En virtud de que el modelo especificado pretende anticipar el emprendimiento como resultado de la administración institucionalista y la gestión del conocimiento, emprendimiento e innovación, se recomienda su contraste empírico.Conclusión. La especificación del modelo establece las diferencias entre docentes, estudiantes y administrativos con respecto a la evaluación, acreditación y certificación de la calidad de los procesos y los productos académicos, así como anticipa escenarios de gestión del conocimiento, el emprendimiento y la innovación.Abstract: Background. Studies warn educational institutionalism; 1) administration of a traditional culture and leadership as a guiding principle of academic programs; 2) the establishment of an agenda focused on knowledge management, entrepreneurship and innovation; 3) strategic partnerships between universities and enterprises as the core of vocational training; 4) multidisciplinary collaborative networks. Objective. Specify a model for research of digital entrepreneurship. Method. A non-experimental, cross-sectional and exploratory study with a nonrandom selection of sources indexed repositories UNAM and UAEMEX took place. Results. Model specification includes five explanatory hypothesis paths dependency relationships between variables eight-beliefs, values, perceptions, knowledge, motives, attitudes, intentions and behavior. Discussion. Under the specified model aims to anticipate the enterprise as a result of the institutionalist management and knowledge management, entrepreneurship and innovation, its empirical test is recommended. Conclusion. Model specification establishes the differences between teachers, students and administrators regarding the evaluation, accreditation and certification of the quality of academic processes and products as well as scenarios anticipated knowledge management, entrepreneurship and innovation

    Evidence for classification of c.1852_1853AA>GC in MLH1 as a neutral variant for Lynch syndrome

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    Background: Lynch syndrome (LS) is an autosomal dominant inherited cancer syndrome characterized by early onset cancers of the colorectum, endometrium and other tumours. A significant proportion of DNA variants in LS patients are unclassified. Reports on the pathogenicity of the c.1852_1853AA>GC (p.Lys618Ala) variant of the MLH1 gene are conflicting. In this study, we provide new evidence indicating that this variant has no significant implications for LS. Methods: The following approach was used to assess the clinical significance of the p.Lys618Ala variant: frequency in a control population, case-control comparison, co-occurrence of the p.Lys618Ala variant with a pathogenic mutation, co-segregation with the disease and microsatellite instability in tumours from carriers of the variant. We genotyped p.Lys618Ala in 1034 individuals (373 sporadic colorectal cancer [CRC] patients, 250 index subjects from families suspected of having LS [revised Bethesda guidelines] and 411 controls). Three well-characterized LS families that fulfilled the Amsterdam II Criteria and consisted of members with the p.Lys618Ala variant were included to assess co-occurrence and co-segregation. A subset of colorectal tumour DNA samples from 17 patients carrying the p.Lys618Ala variant was screened for microsatellite instability using five mononucleotide markers. Results: Twenty-seven individuals were heterozygous for the p.Lys618Ala variant; nine had sporadic CRC (2.41%), seven were suspected of having hereditary CRC (2.8%) and 11 were controls (2.68%). There were no significant associations in the case-control and case-case studies. The p.Lys618Ala variant was co-existent with pathogenic mutations in two unrelated LS families. In one family, the allele distribution of the pathogenic and unclassified variant was in trans, in the other family the pathogenic variant was detected in the MSH6 gene and only the deleterious variant co-segregated with the disease in both families. Only two positive cases of microsatellite instability (2/17, 11.8%) were detected in tumours from p.Lys618Ala carriers, indicating that this variant does not play a role in functional inactivation of MLH1 in CRC patients. Conclusions: The p.Lys618Ala variant should be considered a neutral variant for LS. These findings have implications for the clinical management of CRC probands and their relatives.Generalitat Valenciana in Spain (AP140/08) and the Biomedical Research Foundation from the Hospital of Elche, Spain (FIBElx0902). Conselleria de Educació (Generalitat Valenciana); Fundacion Juan Peran-Pikolinos; Fundacion Carolina-BBVA and Fondo Investigación Sanitaria (FI07/00303). Instituto de Salud Carlos III (INT09/208)

    MixInYeast: A Multicenter Study on Mixed Yeast Infections

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    Invasive candidiasis remains one of the most prevalent systemic mycoses, and several studies have documented the presence of mixed yeast (MY) infections. Here, we describe the epidemiology, clinical, and microbiological characteristics of MY infections causing invasive candidiasis in a multicenter prospective study. Thirty-four centers from 14 countries participated. Samples were collected in each center between April to September 2018, and they were sent to a reference center to confirm identification by sequencing methods and to perform antifungal susceptibility testing, according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST). A total of 6895 yeast cultures were identified and MY occurred in 150 cases (2.2%). Europe accounted for the highest number of centers, with an overall MY rate of 4.2% (118 out of 2840 yeast cultures). Of 122 MY cases, the most frequent combinations were Candida albicans/C. glabrata (42, 34.4%), C. albicans/C. parapsilosis (17, 14%), and C. glabrata/C. tropicalis (8, 6.5%). All Candida isolates were susceptible to amphotericin B, 6.4% were fluconazole-resistant, and two isolates (1.6%) were echinocandin-resistant. Accurate identification of the species involved in MY infections is essential to guide treatment decisions

    Unsuspected and extensive transmission of a drug-susceptible Mycobacterium tuberculosis strain

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    <p>Abstract</p> <p>Background</p> <p>A large and unsuspected tuberculosis outbreak involving 18.7% of the total of the tuberculosis cases studied, was detected in a population-based molecular epidemiological study performed in Zaragoza (Spain) from 2001 to 2004.</p> <p>Methods</p> <p>The <it>Mycobacterium tuberculosis </it>drug-susceptible strain, named <it>MTZ </it>strain, was genetically characterized by IS<it>6110</it>-RFLP, Spoligotyping and by MIRU-VNTR typing and the genetic patterns obtained were compared with those included in international databases. The characteristics of the affected patients, in an attempt to understand why the <it>MTZ </it>strain was so highly transmitted among the population were also analyzed.</p> <p>Results</p> <p>The genetic profile of the <it>MTZ </it>strain was rare and not widely distributed in our area or elsewhere. The patients affected did not show any notable risk factor for TB.</p> <p>Conclusion</p> <p>The <it>M. tuberculosis </it>strain <it>MTZ</it>, might have particular transmissibility or virulence properties, and we believe that greater focus should be placed on stopping its widespread dissemination.</p

    Barriers of mental health treatment utilization among first-year college students: First cross-national results from the WHO World Mental Health International College Student Initiative.

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    BACKGROUND: Although mental disorders and suicidal thoughts-behaviors (suicidal thoughts and behaviors) are common among university students, the majority of students with these problems remain untreated. It is unclear what the barriers are to these students seeking treatment. AIMS: The aim of this study is to examine the barriers to future help-seeking and the associations of clinical characteristics with these barriers in a cross-national sample of first-year college students. METHOD: As part of the World Mental Health International College Student (WMH-ICS) initiative, web-based self-report surveys were obtained from 13,984 first-year students in eight countries across the world. Clinical characteristics examined included screens for common mental disorders and reports about suicidal thoughts and behaviors. Multivariate regression models adjusted for socio-demographic, college-, and treatment-related variables were used to examine correlates of help-seeking intention and barriers to seeking treatment. RESULTS: Only 24.6% of students reported that they would definitely seek treatment if they had a future emotional problem. The most commonly reported reasons not to seek treatment among students who failed to report that they would definitely seek help were the preference to handle the problem alone (56.4%) and wanting to talk with friends or relatives instead (48.0%). Preference to handle the problem alone and feeling too embarrassed were also associated with significantly reduced odds of having at least some intention to seek help among students who failed to report that they would definitely seek help. Having 12-month major depression, alcohol use disorder, and suicidal thoughts and behaviors were also associated with significantly reduced reported odds of the latter outcome. CONCLUSIONS: The majority of first-year college students in the WMH-ICS surveys report that they would be hesitant to seek help in case of future emotional problems. Attitudinal barriers and not structural barriers were found to be the most important reported reasons for this hesitation. Experimental research is needed to determine whether intention to seek help and, more importantly, actual help-seeking behavior could be increased with the extent to which intervention strategies need to be tailored to particular student characteristics. Given that the preference to handle problems alone and stigma and appear to be critical, there could be value in determining if internet-based psychological treatments, which can be accessed privately and are often build as self-help approaches, would be more acceptable than other types of treatments to student who report hesitation about seeking treatment.status: publishe

    WHO World Mental Health Surveys International College Student Project: Prevalence and Distribution of Mental Disorders

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    Increasingly, colleges across the world are contending with rising rates of mental disorders, and in many cases, the demand for services on campus far exceeds the available resources. The present study reports initial results from the first stage of the WHO World Mental Health International College Student project, in which a series of surveys in 19 colleges across 8 countries (Australia, Belgium, Germany, Mexico, Northern Ireland, South Africa, Spain, United States) were carried out with the aim of estimating prevalence and basic sociodemographic correlates of common mental disorders among first-year college students. Web-based self-report questionnaires administered to incoming first-year students (45.5% pooled response rate) screened for six common lifetime and 12-month DSM-IV mental disorders: major depression, mania/hypomania, generalized anxiety disorder, panic disorder, alcohol use disorder, and substance use disorder. We focus on the 13,984 respondents who were full-time students: 35% of whom screened positive for at least one of the common lifetime disorders assessed and 31% screened positive for at least one 12-month disorder. Syndromes typically had onsets in early to middle adolescence and persisted into the year of the survey. Although relatively modest, the strongest correlates of screening positive were older age, female sex, unmarried-deceased parents, no religious affiliation, nonheterosexual identification and behavior, low secondary school ranking, and extrinsic motivation for college enrollment. The weakness of these associations means that the syndromes considered are widely distributed with respect to these variables in the student population. Although the extent to which cost-effective treatment would reduce these risks is unclear, the high level of need for mental health services implied by these results represents a major challenge to institutions of higher education and governments. (PsycINFO Database Record (c) 2018 APA, all rights reserved).status: publishe

    Validation of diabetes mellitus and hypertension diagnosis in computerized medical records in primary health care

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    <p>Abstract</p> <p>Background</p> <p>Computerized Clinical Records, which are incorporated in primary health care practice, have great potential for research. In order to use this information, data quality and reliability must be assessed to prevent compromising the validity of the results.</p> <p>The aim of this study is to validate the diagnosis of hypertension and diabetes mellitus in the computerized clinical records of primary health care, taking the diagnosis criteria established in the most prominently used clinical guidelines as the gold standard against which what measure the sensitivity, specificity, and determine the predictive values.</p> <p>The gold standard for diabetes mellitus was the diagnostic criteria established in 2003 American Diabetes Association Consensus Statement for diabetic subjects. The gold standard for hypertension was the diagnostic criteria established in the Joint National Committee published in 2003.</p> <p>Methods</p> <p>A cross-sectional multicentre validation study of diabetes mellitus and hypertension diagnoses in computerized clinical records of primary health care was carried out. Diagnostic criteria from the most prominently clinical practice guidelines were considered for standard reference.</p> <p>Sensitivity, specificity, positive and negative predictive values, and global agreement (with kappa index), were calculated. Results were shown overall and stratified by sex and age groups.</p> <p>Results</p> <p>The agreement for diabetes mellitus with the reference standard as determined by the guideline was almost perfect (κ = 0.990), with a sensitivity of 99.53%, a specificity of 99.49%, a positive predictive value of 91.23% and a negative predictive value of 99.98%.</p> <p>Hypertension diagnosis showed substantial agreement with the reference standard as determined by the guideline (κ = 0.778), the sensitivity was 85.22%, the specificity 96.95%, the positive predictive value 85.24%, and the negative predictive value was 96.95%. Sensitivity results were worse in patients who also had diabetes and in those aged 70 years or over.</p> <p>Conclusions</p> <p>Our results substantiate the validity of using diagnoses of diabetes and hypertension found within the computerized clinical records for epidemiologic studies.</p
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