2,108 research outputs found

    Government transparency measurement through prioritized distance operators

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    © 2018 - IOS Press and the authors. All rights reserved. The prioritized induced probabilistic ordered weighted average distance (PIPOWAD) has been developed. This new operator is an extension of the ordered weighted average (OWA) operator that can be used in cases where we have two sets of data that want to be compared. Some of the main characteristics of this new operator are: 1) Not all the decision makers are equally important, so the information needs to be prioritized, 2) The information has a probability to occur and 3) The decision makers can change the importance of the information based in an induced variable. Additionally, characteristics and families of the PIPOWAD operator are presented. Finally, an application of the PIPOWAD operator in order to measure government transparency in Mexico is presented

    Earnings management and cultural values

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    Using theory and empirical data from social psychology to measure for cultural differences between countries, we study the effect of individualism as defined by Hofstede (1980) and egalitarianism as defined by Schwartz (1994, 1999, 2004) on earnings management. We find a significant influence of both cultural measures. In line with Licht et al. (2004), who argue that individualistic societies may be less susceptible to corruption, we find that countries scoring high on individualism tend to have lower levels of earnings management. In addition, we find that egalitarianism, defined as a society's cultural orientation with respect to intolerance for abuses of market and political power, is negatively related with earnings management. Our results are robust to different specifications and controls. The main message of this paper is that besides formal institutions, cultural differences are relevant to explain earnings management behaviour. We think that our work adds to the understanding of the importance of cultural values in managerial behaviour across countries contributing to the literature on earnings management and law and institutions

    Understanding the open circuit voltage in organic solar cells on the basis of a donor-acceptor abrupt (p-n++) heterojunction

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    By using electrical characterization and classical solid state semiconductor device theory, we demonstrate that the open circuit voltage (V oc ) in organic solar cells based on non-intentional doped semiconductors is fundamentally limited by the built-in potential (V bi ) originated at a donor-acceptor abrupt (p-n ++ ) heterojunction in case of selective contacts. Our analysis is validated using P3HT:PCBM devices fabricated in our research group. We also demonstrate that such a result can be generalized using data already reported in literature for fullerene-based solar cells. Finally, we show that the dependence of V oc on the device contacts can be understood in terms of the potential barriers formed by the Fermi level alignment of semiconductors at the heterojunction and at the Schottky junctions

    Eficacia de la alta presión hidrostática como tratamiento cuarentenario para mejorar la calidad de los frutos del mango infestados por la mosca de la fruta Mexicana Anastrepha ludens

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    High hydrostatic pressure (HPP) has been reported as an alternative quarantine process in fruits infested by Ceratitis capitata Wiedemann, Rhagoletis indifferens Curran and Cydia pomonella (L.). In Mexico and other Latin-American countries, the Mexican fruit fly Anastrepha ludens Loew is one of the most important insects infesting mangoes, citrus, and other fruits. The present study aimed to determine the effect of pressure level and time on the survival of eggs and larvae of the Mexican fruit fly. Eggs and larvae were pressurized at 25, 50, 75, 100, or 150 MPa for 0, 5, 10 or 20 min at 25 8C. Ripe and green mangoes were also pressurized under the same conditions. On pressurized eggs of 1, 2, 3, and 4 days old, their ability to hatch was recorded. On pressurized first, second and third instars, the percentage of survival was registered. Furthermore, third instars were studied for their ability to pupate and to develop adults. The results showed that although most of eggs and larvae died at pressures lower than 100 MPa, some of them were able to survive even at 150 MPa, and a few third instars were able to pupate and to develop to adulthood. Green mangoes were affected by pressures above 75 MPa but they were more resistant than ripe mangoes. HPP treatments seem to be feasible as a quarantine process for mangoes; however, more studies, such as combining HPP with temperature treatments, are needed in order to decrease the pressure level to avoid fruit damageLa alta presión hidrostática ha sido descrita como un proceso de cuarentena alternativa en frutas infestadas por Ceratitis capitata Wiedemann, Rhagoletis indifferens Curran y Cydia pomonella (L.). En México y otros países Latinoamericanos, la mosca de la fruta mexicana Anastrepha ludens Loew es uno de los más importantes insectos que infestan los mangos, cítricos y otras frutas. El presente estudio tuvo como meta determinar el efecto del nivel de presión y tiempo sobre la supervivencia de huevos y larvas de la mosca de la fruta mexicana. Huevos y larvas se presurizaron a 25, 50, 75, 100, y 150 MPa durante 0, 5, 10, y 20 min a 25 8C. Mangos maduros y verdes también se presurizaron bajo las mismas condiciones. En huevos presurizados de uno, dos, tres y cuatro días de vida, se registró su capacidad para eclosionar. En primera, segunda y tercera etapa larvaria presurizada, el porcentaje de supervivencia también se registró. Además, en la tercera etapa larvaria se estudió su capacidad para salir de la crisálida y desarrollar adultos. Los resultados mostraron que aunque la mayoría de los huevos y larvas murieron a presiones por debajo de 100 MPa, algunos de ellos fueron capaces de sobrevivir aun a 150 MPa, y unas pocas larvas de tercera etapa fueron capaces de salir de la crisálida y desarrollar adultos. Los mangos verdes se vieron afectados por las presiones por encima de 75 MPa pero fueron más resistentes que los mangos maduros. Los tratamientos de alta presión hidrostática parecen ser un proceso viable como método cuarentenario para mangos, sin embargo, se necesitan más estudios tales como la combinación de alta presión hidrostática junto con tratamientos térmicos para disminuir los niveles de presión y evitar daños en la frutaThe authors are grateful to Fondo Mixto CONACYT –Gobierno del Estado de Tamaulipas for the financial support of this work (Project TAMPS-2003-C02-15), to CONACYT for the scholarship granted to author Hugo Ernesto CandelarioS

    Design, Synthesis, Characterization, and Evaluation of the Anti-HT-29 Colorectal Cell Line Activity of Novel 8-Oxyquinolinate-Platinum(II)-Loaded Nanostructured Lipid Carriers Targeted with Riboflavin

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    Colorectal cancer is occasionally called colon or rectal cancer, depending on where cancer begins to form, and is the second leading cause of cancer death among both men and women. The platinum-based [PtCl(8-O-quinolinate)(dmso)] (8-QO-Pt) compound has demonstrated encouraging anticancer activity. Three different systems of 8-QO-Pt-encapsulated nanostructured lipid carriers (NLCs) with riboflavin (RFV) were investigated. NLCs of myristyl myristate were synthesized by ultrasonication in the presence of RFV. RFV-decorated nanoparticles displayed a spherical shape and a narrow size dispersion in the range of 144–175 nm mean particle diameter. The 8-QO-Pt-loaded formulations of NLC/RFV with more than 70% encapsulation efficiency showed sustained in vitro release for 24 h. Cytotoxicity, cell uptake, and apoptosis were evaluated in the HT-29 human colorectal adenocarcinoma cell line. The results revealed that 8-QO-Pt-loaded formulations of NLC/RFV showed higher cytotoxicity than the free 8-QO-Pt compound at 5.0 µM. All three systems exhibited different levels of cellular internalization. Moreover, the hemotoxicity assay showed the safety profile of the formulations (less than 3.7%). Taken together, RFV-targeted NLC systems for drug delivery have been investigated for the first time in our study and the results are promising for the future of chemotherapy in colon cancer treatmen

    Factors Associated with Knowledge of Evacuation Routes and Having an Emergency Backpack in Individuals Affected by a Major Earthquake in Piura, Peru

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    Information on the prevention of earthquakes in Peru, a high-risk country, is still emerging. We determined the frequency and factors associated with knowledge of evacuation routes and the use of emergency backpacks in people affected by a major earthquake. A cross-sectional study using secondary data was conducted from August–December 2021 on people that experienced the 6.1 magnitude earthquake that occurred in Piura, Peru on 30 July 2021. The outcome was self-reported knowledge of evacuation routes and the use of emergency backpacks. The association with self-reported earthquake preparation training, use of sources of information on earthquakes, and sociodemographic variables was investigated. A total of 69.5% of participants knew evacuation routes, and 46.3% had an emergency backpack. A higher frequency of knowledge of evacuation routes was associated with previous training (PR: 1.47; 95% CI: 1.15–1.87), use of the media (PR: 1.35; 95% CI: 1.06–1.72), having received information from the COEN (PR: 1.19; 95% CI: 1.02–1.40), and with a greater number of household members (PR: 1.03; 95% CI: 1.01–1.06). There is a high frequency of knowledge of evacuation routes among participants. However, basic notions of prevention culture are still needed. This research contributes to policy development on earthquake preparation at the community level

    Bacterial cellulose hydrogel loaded with lipid nanoparticles for localized cancer treatment

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    The use of hybrid materials, where a matrix sustains nanoparticles controlling the release of the chemotherapeutic drug, could be beneficial for the treatment of primary tumors prior or after surgery. This localized chemotherapy would guarantee high drug concentrations at the tumor site while precluding systemic drug exposure minimizing undesirable side effects. We combined bacterial cellulose hydrogel (BC) and nanostructured lipid carriers (NLCs) including doxorubicin (Dox) as a drug model. NLCs loaded with cationic Dox (NLCs-H) or neutral Dox (NLCs-N) were fully characterized and their cell internalization and cytotoxic efficacy were evaluated in vitro against MDA-MB-231 cells. Thereafter, a fixed combination of NLCs-H and NLCs-N loaded into BC (BC-NLCs-NH) was assayed in vivo into an orthotopic breast cancer mouse model. NLCs-H showed low encapsulation efficiency (48%) and fast release of the drug while NLCs-N showed higher encapsulation (97%) and sustained drug release. Both NLCs internalized via endocytic pathway, while allowing a sustained release of the Dox, which in turn rendered IC50 values below of those of free Dox. Taking advantage of the differential drug release, a mixture of NLCs-N and NLCs-H was encapsulated into BC matrix (BC-NLCs-NH) and assayed in vivo, showing a significant reduction of tumor growth, metastasis incidence and local drug toxicities.Centro de Investigación y Desarrollo en Fermentaciones IndustrialesCentro de Química Inorgánic

    Bacterial cellulose hydrogel loaded with lipid nanoparticles for localized cancer treatment

    Get PDF
    The use of hybrid materials, where a matrix sustains nanoparticles controlling the release of the chemotherapeutic drug, could be beneficial for the treatment of primary tumors prior or after surgery. This localized chemotherapy would guarantee high drug concentrations at the tumor site while precluding systemic drug exposure minimizing undesirable side effects. We combined bacterial cellulose hydrogel (BC) and nanostructured lipid carriers (NLCs) including doxorubicin (Dox) as a drug model. NLCs loaded with cationic Dox (NLCs-H) or neutral Dox (NLCs-N) were fully characterized and their cell internalization and cytotoxic efficacy were evaluated in vitro against MDA-MB-231 cells. Thereafter, a fixed combination of NLCs-H and NLCs-N loaded into BC (BC-NLCs-NH) was assayed in vivo into an orthotopic breast cancer mouse model. NLCs-H showed low encapsulation efficiency (48%) and fast release of the drug while NLCs-N showed higher encapsulation (97%) and sustained drug release. Both NLCs internalized via endocytic pathway, while allowing a sustained release of the Dox, which in turn rendered IC50 values below of those of free Dox. Taking advantage of the differential drug release, a mixture of NLCs-N and NLCs-H was encapsulated into BC matrix (BC-NLCs-NH) and assayed in vivo, showing a significant reduction of tumor growth, metastasis incidence and local drug toxicities.Centro de Investigación y Desarrollo en Fermentaciones IndustrialesCentro de Química Inorgánic
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