311 research outputs found

    Low-rank approximations of nonseparable panel models

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    We provide estimation methods for nonseparable panel models based on low-rank factor structure approximations. The factor structures are estimated by matrix-completion methods to deal with the computational challenges of principal component analysis in the presence of missing data. We show that the resulting estimators are consistent in large panels, but suffer from approximation and shrinkage biases. We correct these biases using matching and difference-in-differences approaches. Numerical examples and an empirical application to the effect of election day registration on voter turnout in the US illustrate the properties and usefulness of our methods

    Bias corrections for probit and logit models with two-way fixed effects

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    In this article, we present the user-written commands probitfe and logitfe, which fit probit and logit panel-data models with individual and time unobserved effects. Fixed-effects panel-data methods that estimate the unobserved effects can be severely biased because of the incidental parameter problem (Neyman and Scott, 1948, Econometrica 16: –32). We tackle this problem using the analytical and jackknife bias corrections derived in Fernández-Val and Weidner (2016, Journal of Econometrics 192: 291–312) for panels where the two dimensions (N and T) are moderately large. We illustrate the commands with an empirical application to international trade and a Monte Carlo simulation calibrated to this application

    Bioactive and luminescent indole and isatin based gold(i) derivatives

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    A series of luminescent monometallic [AuL(PPh 3 )] (1-3) and bimetallic [Au 2 (µ-dppe)L 2 ] (4, 6, 8) and [Au 2 (µ-dppp)L 2 ] (5, 7, 9) complexes, where L is either 4-cyano-indole, isatin, or 5, 7-dimethyl-isatin, and dppe and dppp are 1, 2-bis(diphenylphosphino)ethane and 1, 3-bis(diphenylphosphino)propane, respectively, have been synthesised. X-ray diffraction confirmed the tendency to establish aurophillic interations for those complexes containing dppe. Luminescence studies and theoretical calculations revealed a different origin for both families, i.e. indole and isatin species. Thus, indole derivatives presented a ligand-to-ligand-charge-transfer transition (LLCT) from the indole to the PPh 3 fragment, whereas for the isatin derivatives an intraligand-charge-transfer transition (ILCT) within the isatin fragment is proposed. In both cases, the gold centre was slightly implicated as a ligand-to-metal-charge transfer transition (LMCT) (from the indole/isatin to Au(i)). Cell antiproliferative assays in lung cancer cells (A549), leukemia Jurkat-pLVTHM and Jurkat-shBak cells (cisplatin sensitive and resistant, respectively) showed excellent cytotoxic values (10.11-0.28 µM), showing the leukemia cells to be the most sensitive and the bimetallic species to be the most active agents. Preliminary studies associated the cytotoxicity with a combination of different factors, the metallic fragment being mainly responsible. Remarkably, these complexes are able to inhibit the cellular growth of cisplatin resistant Jurkat-shBak cells highlighting their promising future as an alternative anticancer agent

    Innate Immune Receptors, Key Actors in Cardiovascular Diseases

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    Cardiovascular diseases (CVDs) are the leading cause of death in the industrialized world. Most CVDs are associated with increased inflammation that arises mainly from innate immune system activation related to cardiac damage. Sustained activation of the innate immune system frequently results in maladaptive inflam- matory responses that promote cardiovascular dysfunction and remodeling. Much research has focused on determining whether some mediators of the innate immune system are potential targets for CVD therapy. The innate immune system has specific receptors—termed pattern recognition receptors (PRRs)—that not only recognize pathogen-associated molecular patterns, but also sense danger-associated molecular signals. Acti- vation of PRRs triggers the inflammatory response in different physiological systems, including the cardio- vascular system. The classic PRRs, toll-like receptors (TLRs), and the more recently discovered nucleotide- binding oligomerization domain-like receptors (NLRs), have been recently proposed as key partners in the progression of several CVDs (e.g., atherosclerosis and heart failure). The present review discusses the key findings related to the involvement of TLRs and NLRs in the progression of several vascular and cardiac diseases, with a focus on whether some NLR subtypes (nucleotide-binding oligomerization domain, leucine rich repeat and pyrin domain-containing receptor 3 and nucleotide-binding oligomerization domain-containing protein 1) can be candidates for the development of new therapeutic strategies for several CVDs

    Innate immune receptors, key actors in cardiovascular diseases

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    Cardiovascular diseases (CVDs) are the leading cause of death in the industrialized world. Most CVDs are associated with increased inflammation that arises mainly from innate immune system activation related to cardiac damage. Sustained activation of the innate immune system frequently results in maladaptive inflammatory responses that promote cardiovascular dysfunction and remodeling. Much research has focused on determining whether some mediators of the innate immune system are potential targets for CVD therapy. The innate immune system has specific receptors—termed pattern recognition receptors (PRRs)—that not only recognize pathogen-associated molecular patterns, but also sense danger-associated molecular signals. Activation of PRRs triggers the inflammatory response in different physiological systems, including the cardiovascular system. The classic PRRs, toll-like receptors (TLRs), and the more recently discovered nucleotide-binding oligomerization domain-like receptors (NLRs), have been recently proposed as key partners in the progression of several CVDs (e.g., atherosclerosis and heart failure). The present review discusses the key findings related to the involvement of TLRs and NLRs in the progression of several vascular and cardiac diseases, with a focus on whether some NLR subtypes (nucleotide-binding oligomerization domain, leucine rich repeat and pyrin domain-containing receptor 3 and nucleotide-binding oligomerization domain-containing protein 1) can be candidates for the development of new therapeutic strategies for several CVDs

    Effects of laser-textured on rake face in turning PCD tools for Ti6Al4V

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    The demand inherent to the aeronautical industry in terms of productivity and quality requirements leads to develop new cutting tools. Hence, PCD tools meet the requirements in productivity while machining low machinability aeronautical alloys such as Ti6Al4V. Tool chipbreakers play a considerable role in terms of tool life. However, due to the extreme conditions (temperature and pressure) required to manufacture PCD tools, any complex geometry on tool rake faces is not viable, so chipbreakers are not possible, except for those external to inserts. This work proposes a groove-type laser engraved chipbreaker design and a manufacturing methodology, with experimental validation on turning a Ti6Al4V workpiece. The so-manufactured chipbreakers achieve titanium alloy chip fragmentation, making easy chip removal from the cutting zone. A set of experiments involving various laser parameters to characterize the PCD depth and surface integrity and experimental validation for those chipbreakers designs were carried out in finishing cutting conditions. The optimum parameters for the engraving of PCD were found, obtaining satisfactory breakage of titanium chips. Chip length was always below 17.29 mm.Authors are grateful to Basque government group IT IT1337- 19, the Ministry of Mineco REF DPI2016-74845-R and PID2019- 109340RB-I00, and the UPV/EHU itself for the financial aid for the pre-doctoral grants PIF 19/96

    BML‐111 treatment prevents cardiac apoptosis and oxidative stress in a mouse model of autoimmune myocarditis.

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    Myocarditis is an inflammation of the myocardium that can progress to a more severe phenotype of dilated cardiomyopathy (DCM). Three main harmful factors determine this progression: inflammation, cell death, and oxidative stress. Lipoxins and their derivatives are endogenous proresolving mediators that induce the resolution of the inflammatory process. This study aims to determine whether these mediators play a protective role in a murine model of experimental autoimmune myocarditis (EAM) by treating with the lipoxin A4 analog BML‐111. We observed that EAM mice presented extensive infiltration areas that correlated with higher levels of inflammatory and cardiac damage markers. Both parameters were significantly reduced in BML‐treated EAM mice. Consistently, cardiac dysfunction, hypertrophy, and emerging fibrosis detected in EAM mice was prevented by BML‐111 treatment. At the molecular level, we demonstrated that treatment with BML‐111 hampered apoptosis and oxidative stress induction by EAM. Moreover, both in vivo and in vitro studies revealed that these beneficial effects were mediated by activation of Nrf2 pathway through CaMKK2‐AMPKα kinase pathway. Altogether, our data indicate that treatment with the lipoxin derivative BML‐111 effectively alleviates EAM outcome and prevents cardiac dysfunction, thus, underscoring the therapeutic potential of lipoxins and their derivatives to treat myocarditis and other inflammatory cardiovascular diseases.pre-print325 K

    Time-lapse cross-hole electrical resistivity tomography (CHERT) for monitoring seawater intrusion dynamics in a Mediterranean aquifer

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    Surface electrical resistivity tomography (ERT) is a widely used tool to study seawater intrusion (SWI). It is noninvasive and offers a high spatial coverage at a low cost, but its imaging capabilities are strongly affected by decreasing resolution with depth. We conjecture that the use of CHERT (cross-hole ERT) can partly overcome these resolution limitations since the electrodes are placed at depth, which implies that the model resolution does not decrease at the depths of interest. The objective of this study is to test the CHERT for imaging the SWI and monitoring its dynamics at the Argentona site, a well-instrumented field site of a coastal alluvial aquifer located 40 km NE of Barcelona. To do so, we installed permanent electrodes around boreholes attached to the PVC pipes to perform time-lapse monitoring of the SWI on a transect perpendicular to the coastline. After 2 years of monitoring, we observe variability of SWI at different timescales: (1) natural seasonal variations and aquifer salinization that we attribute to long-term drought and (2) short-term fluctuations due to sea storms or flooding in the nearby stream during heavy rain events. The spatial imaging of bulk electrical conductivity allows us to explain non-monotonic salinity profiles in open boreholes (step-wise profiles really reflect the presence of freshwater at depth). By comparing CHERT results with traditional in situ measurements such as electrical conductivity of water samples and bulk electrical conductivity from induction logs, we conclude that CHERT is a reliable and cost-effective imaging tool for monitoring SWI dynamics

    The Effect of a Physical Activity Program on the Total Number of Primary Care Visits in Inactive Patients: A 15-Month Randomized Controlled Trial

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    Abstract Background: Effective promotion of exercise could result in substantial savings in healthcare cost expenses in terms of direct medical costs, such as the number of medical appointments. However, this is hampered by our limited knowledge of how to achieve sustained increases in physical activity. Objectives: To assess the effectiveness of a Primary Health Care (PHC) based physical activity program in reducing the total number of visits to the healthcare center among inactive patients, over a 15-month period. Research Design: Randomized controlled trial. Subjects: Three hundred and sixty-two (n = 362) inactive patients suffering from at least one chronic condition were included. One hundred and eighty-three patients (n = 183; mean (SD); 68.3 (8.8) years; 118 women) were randomly allocated to the physical activity program (IG). One hundred and seventy-nine patients (n = 179; 67.2 (9.1) years; 106 women) were allocated to the control group (CG). The IG went through a three-month standardized physical activity program led by physical activity specialists and linked to community resources. Measures: The total number of medical appointments to the PHC, during twelve months before and after the program, was registered. Self-reported health status (SF-12 version 2) was assessed at baseline (month 0), at the end of the intervention (month 3), and at 12 months follow-up after the end of the intervention (month 15). Results: The IG had a significantly reduced number of visits during the 12 months after the intervention: 14.8 (8.5). The CG remained about the same: 18.2 (11.1) (P = .002). Conclusions: Our findings indicate that a 3-month physical activity program linked to community resources is a shortduration, effective and sustainable intervention in inactive patients to decrease rates of PHC visits. Trial Registration: ClinicalTrials.gov NCT0071483

    Impacto del cambio climático en el territorio de la Mancomunidad de Municipios Sostenibles de Cantabria: resultados aplicables a la gestión del territorio

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    RESUMEN: Dentro del marco del proyecto ADAPTACLIMA, del programa INTERREG, se ha analizado el impacto del cambio climático en diez y siete municipios de Cantabria. En primer lugar se identificaron los impactos previsibles a través de la elaboración de matrices. Posteriormente se analizaron los impactos y las posibles medidas de adaptación teniendo en cuenta cuatro aspectos básicos: Potencialidad forestal, Potencialidad agrícola y agro-ganadera, Reservas hídricas y Ordenación del territorio. Se ha analizado la evolución a lo largo del presente siglo de las especies forestales autóctonas y de los cultivos de posible implantación y máximo interés comercial en Cantabria, que incluye la utilización de variedades autóctonas y tradicionales, a la vista de la evolución de la demanda de productos agrarios en el mercado regional, nacional y europeo. Finalmente se han propuesto medidas de adaptación que pasan por una protección estricta de especies forestales autóctonas, por el control y aprovechamiento de las aguas subterráneas y, en última instancia, por la aplicación de un plan de Ordenación Territorial que proteja los elementos más valiosos del territorio, entre ellos los suelos de máxima productividad y los ecosistemas incluidos en la RED NATURA 2000, como protección a la biodiversidad.ABSTRACT: The impact of climate change has been analyzed in eighteen municipalities of Cantabria, within the framework of the project “ADAPTACLIMA” (INTERREG SUDOE IVB). Firstly, the expected impacts were identified by means of matrices. Secondly, those impacts and possible mitigation measures were analyzed considering four aspects: potential forest, potential farming and crops potential, groundwater and land management. The evolution in the course of this century of natural woods and crops with significant trading interest has been analyzed for Cantabria. Such analysis has been carried out considering the farmland products demanded on regional, national and European markets. Finally, in order to protect high productivity soils and the ecosystems included in the “Nature Network 2000”, some impact mitigation measures have been proposed: land and groundwater management and protection of forest native species
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