69 research outputs found

    Disonancia cognitiva ante el cambio climático en apicultores: un caso de estudio en México

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    Climate change in beekeeping is perceived as a relational phenomenon, and it is necessary to adopt adaptation strategies to maintain economic activity. Festinger's theory of Cognitive Dissonance helps understand the constraints to the adoption of climate change adaptation strategies. For this purpose, a survey was applied to explore the relationship between the perception, attitude, and behavior of beekeepers in the face of climate change in Mexican territory. It was noted that: 1) Beekeepers identified climate change as the main problem for beekeeping; 2) They exhibit dissonance between their attitude and their behavior regarding adaptation strategies, and 3) Cognitive dissonance is reduced through justifications for their behavior.  Thus, the present state of dissonance is a limitation for adopting climate change  adaptation actions, evidencing the need to modify the behavior of beekeepers, through training to inform and explain the nature of climate change and its impacts; to place the beekeepers within this context, where they can contribute technical elements that may allow them to reorient their work, promoting an objective and constructive perception, which will generate a positive attitude in the face of the challenges that climate change represents, so that they may modify their behavior as much as necessary in order to keep the activity profitable in Mexico.El cambio climático en la apicultura se percibe como un fenómeno relacional y la adopción de estrategias de adaptación son necesarias para mantener la actividad económica. La teoría de la Disonancia Cognitiva de Festinger, ayuda a comprender las limitantes para la adopción de estrategias de adaptación al cambio climático. Para ello se aplicó una encuesta que permitiera explorar la relación entre la percepción, la actitud y el comportamiento de los apicultores frente al cambio climático en territorio mexicano. Se observó que: 1) los apicultores identificaron el cambio climático como el principal problema de la apicultura; 2) existe disonancia entre la actitud y el comportamiento respecto a las estrategias de adaptación y 3) la disonancia cognitiva se reduce con justificaciones, para su comportamiento.  Por lo tanto el estado de disonancia presente es una limitante para adoptar acciones de adaptación frente al cambio climático, dejando en evidencia la necesidad de modificaciones en el comportamiento de los apicultores, a través de la capacitación dirigida para informar y explicar la naturaleza del cambio climático y sus impactos; de ubicar al apicultor dentro de este contexto donde pueda aportar elementos  técnicos que le permitan reorientar su trabajo, promoviendo una percepción objetiva y constructiva, que genere la actitud positiva suficiente, frente a los retos que el cambio climático representa; para que modifique el comportamiento lo necesario, para mantener la actividad rentable en México

    Equilibration of Concentrated Hard Sphere Fluids

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    We report a systematic molecular dynamics study of the isochoric equilibration of hard-sphere fluids in their metastable regime close to the glass transition. The thermalization process starts with the system prepared in a non-equilibrium state with the desired final volume fraction {\phi} but with a prescribed non-equilibrium static structure factor S_0(k; {\phi}). The evolution of the {\alpha}- relaxation time {\tau}{\alpha} (k) and long-time self-diffusion coefficient DL as a function of the evolution time tw is then monitored for an array of volume fractions. For a given waiting time the plot of {\tau}{\alpha} (k; {\phi}, tw) as a function of {\phi} exhibits two regimes corresponding to samples that have fully equilibrated within this waiting time ({\phi} \leq {\phi}(c) (tw)), and to samples for which equilibration is not yet complete ({\phi} \geq {\phi}(c) (tw)). The crossover volume fraction {\phi}(c) (tw) increases with tw but seems to saturate to a value {\phi}(a) \equiv {\phi}(c) (tw \rightarrow \infty) \approx 0.582. We also find that the waiting time t^(eq)_w({\phi}) required to equilibrate a system grows faster than the corresponding equilibrium relaxation time, t^(eq)({\phi}) \approx 0.27 \times [{\tau}{\alpha} (k; {\phi})]^1.43, and that both characteristic times increase strongly as {\phi} approaches {\phi}^(a), thus suggesting that the measurement of equilibrium properties at and above {\phi}(a) is experimentally impossible

    Inhibición de lipasa pancreática por flavonoides: importancia del doble enlace C2=C3 y la estructura plana del anillo C//Inhibition of pancreatic lipase by flavonoids: relevance of the C2=C3 double bond and C-ring planarity

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    Lipasa pancreática es una enzima clave en el metabolismo de lípidos. Los flavonoides son compuestos bioactivos de gran relevancia debido a sus interacciones con enzimas digestivas. Se evaluó la actividad de lipasa pancreática en presencia de flavonoides. Mediante espectroscopía UVVisible se determinó que el mejor inhibidor fue quercetina, seguido de rutina > luteolina > catequina > hesperetina, con valores de IC50 de 10.30, 13.50, 14.70, 28.50 y 30.50 μM, respectivamente. Todos los flavonoides mostraron una inhibición mixta, excepto catequina que mostró una inhibición acompetitiva. La capacidad inhibitoria de los flavonoides se relacionó con propiedades estructurales compartidas entre los distintos flavonoides, como la hidroxilación en las posiciones C5, C7 (anillo A), C2’ y C3’ (anillo B), y el doble enlace entre C2 y C3 (anillo C). Los resultados de inhibición coincidieron con el análisis de la fluorescencia extrínseca. Los estudios de docking molecular indicaron que la interacción entre lipasa pancreática y los flavonoides fue principalmente mediante interacciones hidrofóbicas (pi-stacking). Las interacciones de todos los flavonoides, excepto rutina, se dieron en el mismo sitio (subsitio 1) de la enzima. La insaturación entre C2 y C3 fue determinante para el acomodo de los flavonoides con la enzima, principalmente por interacciones de pi-stacking.ABSTRACTPancreatic lipase is a key enzyme in lipid metabolism. Flavonoids are bioactive compounds obtained from vegetables with big relevance, due to their intrinsic interaction with digestive enzymes. Pancreatic lipase activity was evaluated in the presence of flavonoids, through UV-Vis spectroscopy. All tested flavonoids showed a mixed-type inhibition, except catechin, which showed a uncompetitive inhibition. The best inhibitor was quercetin followed by rutin > luteolin > catechin > hesperetin, with IC50 values of 10.30, 13.50, 14.70, 28.50 and 30.50 μM, respectively. The flavonoids inhibitory capacity was related to structural properties shared between the different flavonoids, such as the hydroxylation at C5, C7 (ring A), C2’ and C3’ (ring B), and the double bond between C2 and C3 (ring C). The inhibition results are in agreement with the extrinsic fluorescence analysis. Molecular docking studies indicated that the interaction between pancreatic lipase and flavonoids was mainly through hydrophobic interactions (pi-stacking). The interactions of all flavonoids, except rutin, occurred at the same enzyme site (subsite 1). Instauration between C2 and C3 was decisive for the arrangement of flavonoids with the enzyme, mainly due to pi-stacking interactions

    High p27 protein levels in chronic lymphocytic leukemia are associated to low Myc and Skp2 expression, confer resistance to apoptosis and antagonize Myc effects on cell cycle

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    Myc (c-Myc) counteracts p27 effects, and low p27 usually correlates with high Myc expression in human cancer. However there is no information on the co-expression of both genes in chronic lymphocytic leukemia (CLL). We found a lack of correlation between RNA and protein levels of p27 and Myc in CLL cells, so we determined the protein levels by immunoblot in 107 cases of CLL. We observed a high p27 protein expression in CLL compared to normal B cells. Ectopic p27 expression in a CLL-derived cell line resulted in cell death resistance. Surprisingly, Myc expression was very low or undetectable in most CLL cases analyzed, with a clear correlation between high p27 and low Myc protein levels. This was associated with low Skp2 expression, which is consistent with the Skp2 role in p27 degradation and with SKP2 being a Myc target gene. High Myc expression did not correlate with leukemia progression, despite that cell cycle-related Myc target genes were upregulated. However, biochemical analysis showed that the high p27 levels inhibited cyclin-Cdk complexes even in Myc expressing CLL cells. Our data suggest that the combination of high p27 and low Myc is a marker of CLL cells which is mediated by Skp2

    Dynamic equivalence between atomic and colloidal liquids

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    We show that the kinetic-theoretical self-diffusion coefficient of an atomic fluid plays the same role as the short-time self-diffusion coefficient D_S in a colloidal liquid, in the sense that the dynamic properties of the former, at times much longer than the mean free time, and properly scaled with D_S, will indistinguishable from those of a colloidal liquid with the same interaction potential. One important consequence of such dynamic equivalence is that the ratio D_L/ D_S of the long-time to the short-time self-diffusion coefficients must then be the same for both, an atomic and a colloidal system characterized by the same inter-particle interactions. This naturally extends to atomic fluids a well-known dynamic criterion for freezing of colloidal liquids[Phys. Rev. Lett. 70, 1557 (1993)]. We corroborate these predictions by comparing molecular and Brownian dynamics simulations on (soft- and hard-sphere) model systems, representative of what we may refer to as the "hard-sphere" dynamic universality class

    Epigenetic mechanisms of particulate matter exposure: air pollution and hazards on human health

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    Environmental pollution nowadays has not only a direct correlation with human health changes but a direct social impact. Epidemiological studies have evidenced the increased damage to human health on a daily basis because of damage to the ecological niche. Rapid urban growth and industrialized societies importantly compromise air quality, which can be assessed by a notable accumulation of air pollutants in both the gas and the particle phases. Of them, particulate matter (PM) represents a highly complex mixture of organic and inorganic compounds of the most variable size, composition, and origin. PM being one of the most complex environmental pollutants, its accumulation also varies in a temporal and spatial manner, which challenges current analytical techniques used to investigate PM interactions. Nevertheless, the characterization of the chemical composition of PM is a reliable indicator of the composition of the atmosphere, the quality of breathed air in urbanized societies, industrial zones and consequently gives support for pertinent measures to avoid serious health damage. Epigenomic damage is one of the most promising biological mechanisms of air pollution-derived carcinogenesis. Therefore, this review aims to highlight the implication of PM exposure in diverse molecular mechanisms driving human diseases by altered epigenetic regulation. The presented findings in the context of pan-organic cancer, fibrosis, neurodegeneration and metabolic diseases may provide valuable insights into the toxicity effects of PM components at the epigenomic level and may serve as biomarkers of early detection for novel targeted therapies

    Temas Socio-Jurídicos. Volumen 17 No. 37 Diciembre 1999

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    Al cierre de la edición número 37 de la Revista Temas Socio- Jurídicos, registramos la desaparición de la profesora de la Universidad Nacional de Colombia Virginia Gutierrez De Pineda, antropóloga santandereana, profesora, quien en varias oportunidades honró con su presencia y su prestancia a la Universidad Autónoma de Bucaramanga, en especial la Maestría en Derecho de Familia, en la cual atendió el área relacionada con los conflictos entre los géneros, la pareja y la familia. Gus enseñanzas, su acción vital, su permanente indagación de la realidad del país han de servir de ejemplo a quienes deseen seguir la senda de la ciencia y conquistar horizontes de conocimiento. Como homenaje a esta mujer pionera, la revista publica una de sus últimas conferencias pronunciadas en la Universidad, denominada el conflicto en la relación de los géneros. Dos escritos salidos de la pluma del profesor Alfonso Gómez Gómez, el primero sobre el resurgimiento de las provincias, el segundo sobre las Asambleas Departamentales, incitan a la reflexión cobre la necesidad de una reconfiguración de la estructura político-administrativa de las regiones en el País. Proseguimos con la divulgación del ensayo sobre Institutos Jurídicos Básicos, la segunda parte, donde se exponen los fundamentos económico-sociales de las instituciones jurídicas y sus expresiones abstractas en el orden de los conceptos.At the close of the 37th edition of the Socio-Legal Issues Magazine, we recorded the disappearance of the professor at the National University of Colombia, Virginia Gutierrez De Pineda, an anthropologist from Santander, professor, who on several occasions honored the Autonomous University of Bucaramanga, especially the Master's Degree in Family Law, in which he dealt with the area related to conflicts between genders, couples and family. Gus teachings, his vital action, his permanent investigation of the reality of the country must serve as an example to those who wish to follow the path of science and conquer horizons of knowledge. As a tribute to this pioneering woman, the magazine publishes one of her last lectures given at the University, called the conflict in the relationship between genders. Two writings from the pen of Professor Alfonso Gómez Gómez, the first on the resurgence of the provinces, the second on the Departmental Assemblies, encourage reflection on the need for a reconfiguration of the political-administrative structure of the regions in the Country . We continue with the disclosure of the essay on Basic Legal Institutes, the second part, where the socio-economic foundations of legal institutions and their abstract expressions in the order of concepts are exposed

    The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

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    Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation
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