1,189 research outputs found

    Supraspinal modulation of neuronal synchronization by nociceptive stimulation induces an enduring reorganization of dorsal horn neuronal connectivity

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    Despite a profusion of information on the molecular and cellular mechanisms involved in the central sensitization produced by intense nociceptive stimulation, the changes in the patterns of functional connectivity between spinal neurones associated with the development of secondary hyperalgesia and allodynia remain largely unknown. Here we show that the state of central sensitization produced by the intradermal injection of capsaicin is associated with structured transformations in neuronal synchronization that lead to an enduring reorganization of the functional connectivity within a segmentally distributed ensemble of dorsal horn neurones. These changes are transiently reversed by the systemic administration of small doses of lidocaine, a clinically effective procedure to treat neuropathic pain. Lidocaine also reduces the capsaicin-induced facilitation of the spinal responses evoked by weak mechanical stimulation of the skin in the region of secondary but not primary hyperalgesia. The effects of both intradermic capsaicin and systemic lidocaine on the segmental correlation and coherence between ongoing cord dorsum potentials and on the responses evoked by tactile stimulation in the region of secondary hyperalgesia are greatly attenuated in spinalized preparations, showing that supraspinal influences are involved in the reorganization of the nociceptive-induced structured patterns of dorsal horn neuronal connectivity. We conclude that the structured reorganization of the functional connectivity between the dorsal horn neurones induced by capsaicin nociceptive stimulation results from cooperative interactions between supraspinal and spinal networks, a process that may have a relevant role in the shaping of the spinal state in the pathogenesis of chronic pain and analgesia.Peer ReviewedPostprint (author's final draft

    Design of a cost structure for consulting services companies. Caso DEYM Consultants

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    La presente investigación muestra el diseño de una estructura de costos en la empresa DEYM Consultores, tal que proporciona información acerca del impacto que estos tienen en las actividades que se desarrollan y así mismo se analiza su impacto en las ganancias o pérdidas. El estudio se desarrolló bajo una metodología tipo documental y descriptiva, tomando en cuenta los datos de los estados financieros de la empresa, y su filosofía de trabajo. La investigación tuvo como objetivo principal diseñar una estructura de costos para la empresa de servicios DEYM Consultores para proveer mecanismo que permita conocer los costos incurridos en la prestación de sus servicios, así como ser un instrumento base para mejorar la toma de decisiones. Durante la investigación se pudo encontrar los tipos de costos que existen para esta clase de empresas y cuales son más convenientes a la hora de manejar una estructura de costos. Se concluyó que una estructura de costos es de gran relevancia no solo para las empresas industriales o de producción, sino también las de servicios, pues estos determinan principalmente que tan rentables o no son las actividades que desarrolla una empresa.This research shows the design of a cost structure in the company DEYM Consultores, which provides information about the impact that these have on the activities that are developed and also analyzes its impact on profits or losses. The study was developed under a documentary and descriptive methodology, taking into account data from the company's financial statements and its work philosophy. The main objective of the research was to design a cost structure for the service company DEYM Consultores to provide a mechanism to know the costs incurred in the provision of its services, as well as to be a basic instrument to improve decision making. During the research it was possible to find out the types of costs that exist for this type of company and which ones are more convenient when it comes to managing a cost structure. It was concluded that a cost structure is of great relevance not only for industrial or production companies, but also for service companies, since they mainly determine how profitable or not the activities developed by a company are

    ANTOLOGÍA DE MERCADOS FINANCIEROS

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    El programa de mercados financieros se ubica en el plan de estudios de la carrera en contaduría. La antología de mercados financieros está dirigida principalmente a los alumnos del quinto semestre de la carrera de contaduría, sin embargo, puede ser útil para cualquier profesional (docente o alumno) que esté interesado en adquirir conocimiento sobre esta disciplina (Mercados Financieros) y poder llevarlo a la práctica en su ejercicio profesional.La antología de mercados financieros abarca temas relativos al Sistema Financiero Mexicano, los mercados financieros; así como el manejo de los instrumentos de financiamiento, con el antecedente inmediato de los factores que afectan la administración financiera y la relación entre la rentabilidad y riesgo, aplicando la planeación y el control financiero

    The Calar Alto CAFOS Direct Imaging First Data Release

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    We present the first release of the Calar Alto CAFOS direct imaging data, a project led by the Spanish Virtual Observatory with the goal of enhancing the use of the Calar Alto archive by the astrophysics community. Data Release 1 contains 23903 reduced and astrometrically calibrated images taken from March 2008 to July 2019 with a median of the mean uncertainties in the astrometric calibration of 0.04 arcsec. The catalogue associated to 6132 images in the Sloan gris filters provides accurate astrometry and PSF calibrated photometry for 139337 point-like detections corresponding to 21985 different sources extracted from a selection of 2338 good-quality images. The mean internal astrometric and photometric accuracies are 0.05 arcsec and 0.04 mag, respectively In this work we describe the approach followed to process and calibrate the images, and the construction of the associated catalogue, together with the validation quality tests carried out. Finally, we present three cases to prove the science capabilities of the catalogue: discovery and identification of asteroids, identification of potential transients, and identification of cool and ultracool dwarfs

    Cellulose-Based Polymer Composite with Carbon Black for Tetrahydrofuran Sensing

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    This work focused on studying the sensing efficiency of tetrahydrofuran (THF) by composite films made of thin layers of a cellulose-based polymer and carbon black. We analyze the reproducibility, durability, desorption time, and the sensitivity percent as a function of the amount of solvent. Two types of experiments were conducted, (1) progressive sensing test (PST) which consisted of progressively increasing the amount of solvent from 0.1 mL increments up to 1.0 mL and (2) multiple sensing test (MST) where the layers were subjected to consecutive pulses of the same amount of solvent, with a minimum of 0.1 mL and a maximum of 0.4 mL. The response and desorption times were a few seconds, and the sensitivity percent ranged from 1% to 170% and was dependent on the solvent quantity

    Cuarentena por COVID-19, factor asociado al consumo de drogas legales en estudiantes de enfermería

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    Introducción: en la pandemia por COVID-19 se han implementado políticas de salud poco usuales como la cuarentena en la población, modificando entornos sociales, laborales y escolares siendo los jóvenes los más afectados ya que no todos estaban preparados para acatar esas indicaciones, generando estrés o ansiedad, afecciones que generalmente son remediadas por el consumo de drogas psicoactivas como alcohol y tabaco. Objetivo: determinar si la cuarentena por COVID-19, es un factor de consumo de drogas legales en estudiantes de Enfermería. Método: investigación cuantitativa, descriptiva, correlacional, prospectiva y trasversal, en una muestra de 266 estudiantes de la Licenciatura de Enfermería de la Región Orizaba de la Universidad Veracruzana, con muestreo no probabilístico por cuota. Se aplicó el AUDIT y ASSIST de la OMS. Resultados: 86.1% posee conocimiento alto sobre COVID-19, 63.5% ingirió alcohol en la vida, 30.8% toma de 1 a 2 copas y 93.3% nunca perdió la noción de lo que sucedía. Por otro lado, 59.0% probó tabaco, 16.2% consumieron 1 o 2 veces en tres meses y 100% negó padecer problemas por este hábito. Conclusión: 20.4% son hombres y 79.6% mujeres de distintas edades y semestres, 92.5% no tuvo COVID-19, 53.0% son consumidores ocasionales de alcohol y 29.5% fuman con riesgo bajo, en aquellas personas que tuvieron resultados bajos de conocimiento de COVID-19, aumentó el uso de alcohol (rs= -.121, p <0.05), para el uso de tabaco no hubo cambios; los resultados se contraponen con otros autores.   Introduction: during the COVID-19 pandemic, unusual health policies such as quarantine have been implemented in the population, modifying social, work and school environments, with young people being the most affected since not all of them were prepared to comply with these indications, generating stress or anxiety, conditions that are generally remedied by the consumption of psychoactive drugs such as alcohol and tobacco. Objective: to determine whether COVID-19 quarantine is a factor in the consumption of legal drugs in nursing students. Method: quantitative, descriptive, correlational, prospective and transversal research, in a sample of 266 students of the Nursing Degree of the Orizaba Region of the Universidad Veracruzana, with non-probabilistic sampling by quota. The AUDIT and ASSIST of the WHO were applied. Results: 86.1% had a high knowledge of COVID-19, 63.5% had ingested alcohol in their lifetime, 30.8% had 1 to 2 drinks and 93.3% had never lost track of what was happening. On the other hand, 59.0% tried tobacco, 16.2% consumed 1 or 2 times in three months and 100% denied suffering problems due to this habit. Conclusion: 20.4% are men and 79.6% women of different ages and semesters, 92.5% did not have COVID-19, 53.0% are occasional alcohol consumers and 29.5% smoke with low risk, in those people who had low COVID-19 knowledge results, alcohol use increased (rs= -.121, p <0.05), for tobacco use there were no changes; the results are in contrast with other authors

    Supraspinal shaping of adaptive transitions in the state of functional connectivity between segmentally distributed dorsal horn neuronal populations in response to nociception and antinociception

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    In the anesthetized cat the correlation between the ongoing cord dorsum potentials(CDPs) recorded from different lumbar spinal segments has a non-random structure,suggesting relatively stable patterns of functional connectivity between the dorsalhorn neuronal ensembles involved in the generation of these potentials. During thenociception induced by the intradermic injection of capsaicin, the patterns of segmentalcorrelation between the spontaneous CDPs acquire other non-random configurationsthat are temporarily reversed to their pre-capsaicin state by the systemic injectionof lidocaine, a procedure known to decrease the manifestation of neuropathic painin both animals and humans. We have now extended these studies and utilizedmachine learning for the automatic extraction and selection of particular classes ofCDPs according to their shapes and amplitudes. By using a Markovian analysis, wedisclosed the transitions between the different kinds of CDPs induced by capsaicinand lidocaine and constructed a global model based on the changes in the behaviorof the CDPs generated along the whole set of lumbar segments. This allowed theidentification of the different states of functional connectivity within the whole ensembleof dorsal horn neurones attained during nociception and their transitory reversal bysystemic administration of lidocaine in preparations with the intact neuroaxis and afterspinalization. The present observations provide additional information on the stateof self-organized criticality that leads to the adaptive behavior of the dorsal hornneuronal networks during nociception and antinociception both shaped by supraspinaldescending influencesPeer ReviewedPostprint (published version

    Reproductive biology of the freshwater drum Aplodinotus grunniens in Tabasco, Mexico/Biología reproductiva del tambor de agua dulce Aplodinotus grunniens en Tabasco, México

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    Aplodinotus grunniens supports a sustained artisanal shery in the Usumacinta River; however, there are few studies to understand the population dynamics of the species. Relevant aspects of the reproductive biology were documented over an annual cycle, using 593 specimens captured with seine nets. The results indicate that females had a median TL of 32.05 cm, while males had 29.71 cm. The estimated sex ratio was 1.2:1 (males: females). The length-weight relationship showed signicant dierence between sexes, observing an allometric-type growth represented by TW=0.0013(TL)3.5985 with 89.17 % of the data variability explained by the model. Gonadosomatic index (GSI) in females was higher in September (4.29), with males displaying a higher GSI in October (1.02). The highest HSI increase in females was observed in October (1.0). The estimated relative fecundity was 138.74 (± 74.30) oocytes/g of female weight. The macroscopic analysis of gonads indicates that the highest frequency of mature females occurs in June (75 %), while in males it takes place in March and June (35 %). The estimated L50 for females was 31.89 cm (TL) and 28.78 cm (TL) for males. Though A. grunniens reproduces throughout the year, reproductive peaks coincide with the period when the river level decreases, and shing increases considerably. Hence, preventive measures must be applied in regards to the size of the species at capture and the exploitation volumes of this resource

    The effects of DNA methylation and histone deacetylase inhibitors upon the human papillomavirus early genes expression in cervical cancer. An in vitro and clinical study

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    BACKGROUND: The methylation status at the human papilloma virus (HPV) genome found in pre-invasive and invasive cervical lesions suggests that neoplastic transformation can be suppressed by gene hypermethylation, whereas hypomethylation accompanies or causes cancer progression; hence, epigenetic therapy aimed at reactivating cellular suppressor-gene expression has the potential to act as a tumor promoter by enhancing HPV oncoprotein expression in HPV-related malignancies. The objective of this study was to determine the influence of hydralazine and valproate on HPV oncogene expression in cervical cancer cell lines and the primary tumors of patients undergoing treatment with hydralazine and valproate. RESULTS: Overall, hydralazine and valproate either alone or combined exerted a growth inhibitory effect on cervical cancer cell lines. A cell line-specific up-regulating effect was observed on E6/E7 gene expression, which in general correlated with DNA hypomethylation and histone acetylation at the long control region (LCR). Nonetheless, E6/E7 expression was unchanged or decreased in the majority of patients with cervical cancer treated with hydralazine, valproate, or both. In some cervical cancer cell lines, these drugs led to increased transcription of p53, and increased its stabilization due to acetylation at lysines 273 and 282, which allowed a higher bax-protein transactivating effect. CONCLUSION: The results of this study demonstrate that hydralazine and valproate can be safely administered to HPV-related malignancies such as cervical cancer because they do not increase viral oncoprotein expression. Most importantly, the antitumor effect of hydralazine and valproate in cervical cancer may at least partially depend on an up-regulating effect on p53 gene and on the valproate-induced hyperacetylation of p53 protein, protecting it from degradation by E6

    Producción de etanol a partir de melaza de caña de azúcar y diferentes cepas de levadura

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    The application of different sugar cane molasses conditions (yeast strain, antibiotic concentration and molasses pH) was aimed at obtaining the highest ethanol yield. In ethanol production, a 3x3x3 factorial design was used with 3 replicates per treatment, with antibiotic concentration levels: 10 ppm, 15 ppm and 20 ppm; pH: 4.6, 4.8 and 5.0 and yeast strains: Fleish-mann, Red Star and Fermipan Brown. The process applied involved molasses conditioning, fermentation and distillation. The results showed that the maximum ethanol yield (314.13 ± 8.77 L/MT of molasses) was obtained with the yeast strain Saccharomyces cerevisiae Fermipan Brown at pH 4.8 and antibiotic concentration of 15 ppm. In conclusion, the proposed treatment was shown to have a higher productivity in relation to the other proposed methods.La aplicación de diferentes condiciones de melaza de caña de azúcar (cepa de levadura, concentración de antibiótico y pH de melaza) tuvo como objetivo obtener el mayor rendimiento productivo de etanol. En la producción de etanol se empleó un diseño factorial 3x3x3 con 3 repeticiones por tratamiento, con niveles de concentración de antibiótico; 10 ppm, 15 ppm y 20 ppm; pH: 4,6; 4.8 y 5,0 y cepas de levadura: Fleishmann, Red Star y Fermipan Brown. El proceso aplicado tuvo como operaciones el acondicionamiento de la melaza, fermentación y destilación. Los resultados demostraron que el máximo rendimiento de etanol (314,13 ± 8,77 L/TM de melaza) fue obtenido con la cepa de levadura Saccharomyces cerevisiae Fermipan Brown a un pH de 4,8 y concentración de antibiótico de 15 ppm. En conclusión, tratamiento propuesto ha demostrado tener una mayor productividad en relación con los otros métodos propuestos
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