199 research outputs found

    Manual de técnicas constructivas : material de estudio

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    Toda obra civil debe brindar al usuario condiciones de seguridad, habitabilidad, durabilidad, estética y adecuación ambiental, las cuales deben materializarse durante la ejecución de la obra. Para contribuir a cumplir con estos aspectos, se ha desarrollado este manual, buscando constituirse en una herramienta práctica de consulta permanente. Se desarrollan temas desde el inicio del proyecto, todas las etapas constructivas hasta las terminaciones, incluyendo la descripción de máquinas y herramientas para la construcción. Este material es el producto de una revisión bibliográfica de los principales textos de técnica constructiva, complementado con el aporte y la experiencia de los profesionales responsables de su compaginación y edición

    PCR Assay for Detection of Staphylococcus aureus in Fresh Lettuce (Lactuca sativa)

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    The growth in food demand and production growth of vegetables have led to the development of intensive production systems with the aim of having regular access to enough high‐quality food. The aim is to determine the incidence of Staphylococcus aureus in fresh lettuce by PCR in order to enhance the efficiency for detection and identification process. The Baird‐Parker method was used for isolating pathogens from 54 lettuce samples. Genomic DNA extraction was performed according the Mericon DNA Bacteria Plus Kit. The detection by PCR was performed using the pair of primers: coa gene (5′‐ATAGAGCTGATGGTACAGG‐3′ and 5′‐GCTTCCGATTGTTCGATGC‐3′). The phylogenetic tree was constructed by comparing conserved sequences from the adjacent 16S gene, using the F2C 5′‐AGAGTTTGATCATGGCTC‐3′ and C 5′‐ACGGGCGGTGTGTAC‐3′ primers. To test the antimicrobial effect, we used the disk diffusion method (Kirby‐Bauer) using Mueller‐Hinton agar and five antibiotics with different concentrations. The incidence of S. aureus was 1.7%. All the isolates were situated in the ATCC 11632 clade in accordance with other reported sequences belonging to this pathogen in the NCBI database. All the isolates seemed to be resistant to penicillin (10U). The molecular techniques used in this study are suitable for the identification of S. aureus isolated from lettuce, increasing our capability of detecting this pathogen by improving the process and increasing the efficiency contributing to the safety of this vegetable

    Dieta de herbívoros: técnica, importancia e implicaciones en el manejo de fauna silvestre

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    Objective: To review the contributions and implications of the microhistological technique in the management of wild herbivores and to provide recommendations for diet studies. Design/methodology/approach: A meta-analysis was carried out on diet subjects in wild cervids and bovines in North America, in order to know the approaches of diet studies in the management of these species. These works are described and discussed and recommendations are given to adequately perform the microhistological technique. Results: The microhistological technique is a fundamental tool in diet studies in wild herbivores. It has been used to evaluate the carrying capacity of species of hunting interest such as bighorn sheep. The use of sodium hypochlorite as a method of thinning has been questioned, however, it allows to identify cell structures efficiently, as long as the thinning time is not excessive. Dietary studies should be accompanied by an evaluation of forage availability. The stool collection must take place at least during the four seasons of the year and the number of samples must not be less than 50 samples per season. Limitations of the study/implications: The use of the microhistological technique assumes that all plant species have the same percentage of digestibility. However, it allows to determine the diet in fecal samples, which is indispensable in evaluations of carrying capacity for wild herbivores. Findings/Conclusions: The microhistological technique in the study of bighorn sheep using sodium hypochlorite has been an adequate method of thinning plant samples, to determine the availability of forage and in the determination of the diet are two aspects intimately linked for evaluations of habitat of this wild herbivore.Objetivo: Revisar los aportes e implicaciones de la técnica microhistológica en el manejo de herbívoros silvestres y brindar recomendaciones para realizar estudios de dieta.   Diseño/metodología/aproximación: Se realizó un meta-análisis en temas de dieta en cérvidos y bóvidos silvestres en Norteamérica, con la finalidad de conocer los enfoques de los estudios sobre dieta en el manejo de estas especies. Se describen estos trabajos, discuten, y brindan recomendaciones para realizar adecuadamente la técnica microhistológica. Resultados: La técnica microhistológica es una herramienta fundamental en estudios de dieta en herbívoros silvestres. Ha sido utilizada para evaluar la capacidad de carga de especies de interés cinegético como el borrego cimarrón. El uso de hipoclorito de sodio como método de aclareo ha sido cuestionado; sin embargo, permite identificar las estructuras celulares eficazmente, siempre y cuando el tiempo de aclareo no sea excesivo. Los estudios de dieta deben estar acompañados de una evaluación de disponibilidad de forraje. La recolecta de heces debe realizarse al menos durante las cuatro estaciones del año y número de muestras debe ser superior a 50 por estación. Limitaciones del estudio/implicaciones: El uso de la técnica microhistológica asume que todas las especies vegetales tienen el mismo porcentaje de digestibilidad. Permite determinar la dieta en muestras fecales, lo cual es indispensable en evaluaciones de capacidad de carga para herbívoros silvestres. Hallazgos/conclusiones: La técnica microhistológica en el estudio del borrego cimarrón usando el hipoclorito de sodio ha resultado un adecuado método de aclareo de muestras vegetales y determinar la disponibilidad de forraje y con ello definir la dieta, aspectos íntimamente ligados para evaluaciones de hábitat de este herbívoro silvestre

    Structure Discovery in Mixed Order Hyper Networks

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    Background  Mixed Order Hyper Networks (MOHNs) are a type of neural network in which the interactions between inputs are modelled explicitly by weights that can connect any number of neurons. Such networks have a human readability that networks with hidden units lack. They can be used for regression, classification or as content addressable memories and have been shown to be useful as fitness function models in constraint satisfaction tasks. They are fast to train and, when their structure is fixed, do not suffer from local minima in the cost function during training. However, their main drawback is that the correct structure (which neurons to connect with weights) must be discovered from data and an exhaustive search is not possible for networks of over around 30 inputs.  Results  This paper presents an algorithm designed to discover a set of weights that satisfy the joint constraints of low training error and a parsimonious model. The combined structure discovery and weight learning process was found to be faster, more accurate and have less variance than training an MLP.  Conclusions  There are a number of advantages to using higher order weights rather than hidden units in a neural network but discovering the correct structure for those weights can be challenging. With the method proposed in this paper, the use of high order networks becomes tractable

    Where form and substance meet: using the narrative approach of re-storying to generate research findings and community rapprochement in (university) mathematics education

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    Storytelling is an engaging way through which lived experience can be shared and reflected upon, and a tool through which difference, diversity—and even conflict—can be acknowledged and elaborated upon. Narrative approaches to research bring the richness and vibrancy of storytelling into how data is collected and interpretations of it shared. In this paper, I demonstrate the potency of the narrative approach of re-storying for a certain type of university mathematics education research (non-deficit, non-prescriptive, context-specific, example-centred and mathematically focused) conducted at the interface of two communities: mathematics education and mathematics. I do so through reference to Amongst Mathematicians (Nardi, 2008), a study carried out in collaboration with 20 university mathematicians from six UK mathematics departments. The study deployed re-storying to present data and analyses in the form of a dialogue between two fictional, yet entirely data-grounded, characters—M, mathematician, and RME, researcher in mathematics education. In the dialogues, the typically conflicting epistemologies—and mutual perceptions of such epistemologies—of the two communities come to the fore as do the feasibility-of, benefits-from, obstacles-in and conditions-for collaboration between these communities. First, I outline the use of narrative approaches in mathematics education research. Then, I introduce the study and its use of re-storying, illustrating this with an example: the construction of a dialogue from interview data in which the participating mathematicians discuss the potentialities and pitfalls of visualisation in university mathematics teaching. I conclude by outlining re-storying as a vehicle for community rapprochement achieved through generating and sharing research findings—the substance of research—in forms that reflect the fundamental principles and aims that underpin this research. My conclusions resonate with sociocultural constructs that view mathematics teacher education as contemporary praxis and the aforementioned inter-community discussion as taking place within a third space

    Inhibitors of apoptosis proteins in human cervical cancer

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    BACKGROUND: It has been shown that IAPs, in particular XIAP, survivin and c-IAP1, are overexpressed in several malignancies. In the present study we investigate the expression of c-IAP1, c-IAP2, XIAP and survivin and its isoforms in cervical cancer. METHODS: We used semiquantitative RT-PCR assays to analyze 41 cancer and 6 normal tissues. The study included 8 stage I cases; 16 stage II; 17 stageIII; and a control group of 6 samples of normal cervical squamous epithelial tissue. RESULTS: c-IAP2 and XIAP mRNA levels were similar among the samples, cervical tumors had lower c-IAP1 mRNA levels. Unexpectedly, a clear positive association was found between low levels of XIAP and disease relapse. A log-rank test showed a significant inverse association (p = 0.02) between XIAP expression and tumor aggressiveness, as indicated by disease relapse rates. There were no statistically significant differences in the presence or expression levels of c-IAP1 and c-IAP2 among any of the clinical variables studied. Survivin and its isoforms were undetectable in normal cervical tissues, in contrast with the clear upregulation observed in cancer samples. We found no association between survivin expression and age, clinical stage, histology or menopausal state. Nevertheless, we found that adenocarcinoma tumors expressed higher levels of survivin 2B and DeltaEx3 (p = 0.001 and p = 0.04 respectively, by Kruskal-Wallis). A multivariate Cox's partial likelihood-based analysis showed that only FIGO stage was an independent predictor of outcome. CONCLUSION: There are no differences in the expression of c-IAP2 and XIAP between normal vs. cancer samples, but XIAP expression correlate in cervical cancer with relapse of this disease in the patients. Otherwise, c-IAP1 was downregulated in the cervical cancer samples. The expression of survivin was upregulated in the patients with cervical cancer. We have found that adenocarcinoma presented higher levels of survivin isoforms 2B and DeltaEx3

    Full-Exon Pyrosequencing Screening of BRCA Germline Mutations in Mexican Women with Inherited Breast and Ovarian Cancer

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    Hereditary breast cancer comprises 10% of all breast cancers. The most prevalent genes causing this pathology are BRCA1 and BRCA2 (breast cancer early onset 1 and 2), which also predispose to other cancers. Despite the outstanding relevance of genetic screening of BRCA deleterious variants in patients with a history of familial cancer, this practice is not common in Latin American public institutions. In this work we assessed mutations in the entire exonic and splice-site regions of BRCA in 39 patients with breast and ovarian cancer and with familial history of breast cancer or with clinical features suggestive for BRCA mutations by massive parallel pyrosequencing. First we evaluated the method with controls and found 41–485 reads per sequence in BRCA pathogenic mutations. Negative controls did not show deleterious variants, confirming the suitability of the approach. In patients diagnosed with cancer we found 4 novel deleterious mutations (c.2805_2808delAGAT and c.3124_3133delAGCAATATTA in BRCA1; c.2639_2640delTG and c.5114_5117delTAAA in BRCA2). The prevalence of BRCA mutations in these patients was 10.2%. Moreover, we discovered 16 variants with unknown clinical significance (11 in exons and 5 in introns); 4 were predicted as possibly pathogenic by in silico analyses, and 3 have not been described previously. This study illustrates how massive pyrosequencing technology can be applied to screen for BRCA mutations in the whole exonic and splice regions in patients with suspected BRCA-related cancers. This is the first effort to analyse the mutational status of BRCA genes on a Mexican-mestizo population by means of pyrosequencing

    Diverse values of nature for sustainability

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    Twenty-five years since foundational publications on valuing ecosystem services for human well-being1,2, addressing the global biodiversity crisis3 still implies confronting barriers to incorporating nature’s diverse values into decision-making. These barriers include powerful interests supported by current norms and legal rules such as property rights, which determine whose values and which values of nature are acted on. A better understanding of how and why nature is (under)valued is more urgent than ever4. Notwithstanding agreements to incorporate nature’s values into actions, including the Kunming-Montreal Global Biodiversity Framework (GBF)5 and the UN Sustainable Development Goals6, predominant environmental and development policies still prioritize a subset of values, particularly those linked to markets, and ignore other ways people relate to and benefit from nature7. Arguably, a ‘values crisis’ underpins the intertwined crises of biodiversity loss and climate change8, pandemic emergence9 and socio-environmental injustices10. On the basis of more than 50,000 scientific publications, policy documents and Indigenous and local knowledge sources, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) assessed knowledge on nature’s diverse values and valuation methods to gain insights into their role in policymaking and fuller integration into decisions7,11. Applying this evidence, combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures

    Escucha México, Estrategias Gráficas y Cultura Auditiva. Otoño 2022

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    Este reporte del PAP Escucha México, perteneciente al trabajo realizado durante el periodo de Otoño 2022, cuenta con información detallada sobre los resultados alcanzados en cada uno de los proyectos que integran esta organización en el período anteriormente establecido. Para este proceso en específico, se buscó enfocar la mayor cantidad de esfuerzos posibles a que el 4to Encuentro Internacional de Cultura Auditiva se desarrollara de la mejor forma posible, sin descuidar el trabajo que se siguió realizando en el resto de proyectos. Como resumen general, todos presentaron resultados positivos, pues se tuvo presencia importante en redes sociales, mejor que en periodos anteriores, además de que se combinaron esfuerzos para que el 4to Encuentro tuviera una difusión adecuada y alcanzara a la mayor cantidad de personas posibles, lo que a su vez resultó en eventos llenos de gente interesada en aprender sobre Cultura Auditiva y Discapacidad, ejes temáticos centrales de este PAP.ITESO, A.C
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