352 research outputs found
Funsiones de Oferta de Productos Avicolas en Nicaragua periodo 1994-2015 : Estimación de coeficientes de elsticidad precio-oferta de corto y largo plazo
Los modelos de Oferta, es uno de los aspectos de los que se ha ocupado la teoría microeconómica moderna, se ha venido utilizando para dar respuesta a una gran variedad de cuestiones prácticas. En este sentido, con el fin de convertirlo en un instrumento verdaderamente útil, ha existido el interés a través de la investigación aplicada de saber cuánto responde a las variaciones de los precios.
La relación cuantitativa entre el precio y la cantidad ofrecida, dicha teoría la analiza utilizando el concepto de elasticidad-precio, es decir, esta se conceptualiza como un indicador relativo que mide el grado de respuesta o sensibilidad de la cantidad ofrecida ante cambios en el precio.
El comportamiento de la oferta del sector agropecuario, ha sido objeto de renovada atención por parte de los economistas en las últimas décadas. De acuerdo con (Bishop & Toussaint, 1994), son muchos los intentos empíricos que se han hecho para estimar hasta qué punto los agricultores responden a los cambios de precios.
No obstante, dada las particularidades del sector agropecuario que lo diferencian del resto de sectores de la economía nacional, estimar funciones de oferta presenta serias dificultades debido a sus problemas estructurales, ligada a condiciones naturales fuera del control directo de los agricultores que restringen su expansión, imposibilitando su ajuste de forma inmediata y poder aprovechar aquellas situaciones de alza de precios en el mercado.
El presente trabajo, titulado “Estimación de Funciones de Oferta de Productos Avícolas en Nicaragua, durante el período 1994-2015”, tiene como propósito, analizar cuantitativamente la respuesta de los productores avícola a los precios de la carne y huevos, teniendo en cuenta la influencia que estos tienen en distintos períodos cercano al de la toma de decisiones.
Dado que la estimación de funciones de oferta persigue diferentes objetivos, en dicho estudio, concretamente se persigue estimar coeficientes de elasticidad precio-oferta de corto y largo plazo, para ello se utiliza el modelo de análisis de funciones de oferta agrícola de Marc Nerlove (1958), más objetivamente adaptado a la oferta de productos avícolas en Nicaragua.
La investigación se estructura en cuatro capítulos, siendo estos los siguientes:
En el primer capítulo, se aborda el diseño de la investigación, abordando el contenido lógico que exige toda investigación empírica en su primera fase para posterior realizar el desarrollo científico.
El segundo capítulo, analiza en forma sucinta, el aporte del sector avícola en las últimas tres décadas en los agregados macroeconómicos del país desde el punto de vista de su aportación al PIB, empleo, modelo productivo, la seguridad alimentaria y el comercio exterior; de igual forma se enfatiza en la estructura actual del mercado, su marco legal y regulatorio.
El tercer capítulo, presenta el modelo teórico econométrico modificado con datos reales de nuestro país y el análisis de los resultados cuantitativos de las estimaciones de los coeficientes de elasticidad precio oferta de corto y largo plazo de los productos carne y huevo avícola.
Y por último se presentan las principales conclusiones y recomendaciones finales a que llega el estudio
Status of Ultra-High Concentrator Multijunction Solar Cell Development at IES-UPM.
After the successful implementation of a record performing dual-junction solar cell at ultra high concentration, in this paper we present the optimization of key aspects in the transition to a triple-junction device, namely the hetero nucleation of III-V structures onto germanium substrates. This optimization is based on in-situ RAS measurements during the MOVPE growth of the triple-junction solar cell structure and subsequent AFM analysis. The correlation between RAS and AFM allows detecting which RAS features correlate with good morphology and low RMS roughness. TEM analysis confirms that the quality of the triple-junction structures grown is good, revealing no trace of antiphase disorder, and showing flat, sharp and clear interfaces. Triple-junction solar cells manufactured on these structures have shown a peak efficiency of 36.2% at 700X, maintaining an efficiency over 35% from 300 to 1200 suns
Voltage collapse point evaluation considering the load dependence in a power system stability problem
Voltage Stability has emerged in recent decades as one of the most common phenomena, occurrence in Electrical Power Systems. Prior researches focused on the development of algorithm indices to solve the stability problem and in the determination of factors with most influence in voltage collapse to solve the stability problem. This paper evaluates the influence that the load dependence has with the voltage on the phenomenon of the voltage stability and especially on the characteristics the collapse point or instability point. Load modeling used is detailed and comparisons of the results obtained are made with those described in the bibliography and those obtained with commercial software. The results of the load margin are also compared when a constant load or a voltage-dependent load is considered as well as the values obtained at the maximum load point and the point of voltage instability
Identification of circulating microRNA profiles associated with pulmonary function and radiologic features in survivors of SARS-CoV-2-induced ARDS
ABSTRACT
There is a limited understanding of the pathophysiology of postacute pulmonary sequelae in severe COVID-19. The aim of current study was to define the circulating microRNA (miRNA) profiles associated with pulmonary function and radiologic features in survivors of SARS-CoV-2-induced ARDS. The study included patients who developed ARDS secondary to SARS-CoV-2 infection (n=167) and a group of infected patients who did not develop ARDS (n=33). Patients were evaluated 3 months after hospital discharge. The follow-up included a complete pulmonary evaluation and chest computed tomography. Plasma miRNA profiling was performed using RT-qPCR. Random forest was used to construct miRNA signatures associated with lung diffusing capacity for carbon monoxide (DLCO) and total severity score (TSS). Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses were conducted. DLCO<80% predicted was observed in 81.8% of the patients. TSS showed a median [P25;P75] of 5 [2;8]. The miRNA model associated with DLCO comprised miR-17-5p, miR-27a-3p, miR-126-3p, miR-146a-5p and miR-495-3p. Concerning radiologic features, a miRNA signature composed by miR-9-5p, miR-21-5p, miR-24-3p and miR-221-3p correlated with TSS values. These associations were not observed in the non-ARDS group. KEGG pathway and GO enrichment analyses provided evidence of molecular mechanisms related not only to profibrotic or anti-inflammatory states but also to cell death, immune response, hypoxia, vascularization, coagulation and viral infection. In conclusion, diffusing capacity and radiological features in survivors from SARS-CoV-2-induced ARDS are associated with specific miRNA profiles. These findings provide novel insights into the possible molecular pathways underlying the pathogenesis of pulmonary sequelae.
Trial registration: ClinicalTrials.gov identifier: NCT04457505..
Trial registration: ISRCTN.org identifier: ISRCTN16865246..This work is supported by Instituto de Salud Carlos III (COV20/00110), co-funded by European Regional Development Fund (ERDF)/“A way to make Europe”. CIBERES is an initiative of the Instituto de Salud Carlos III. CIBERES is an initiative of the Instituto de Salud Carlos III. Suported by: Programa de donaciones "estar preparados" UNESPA (Madrid, Spain) and Fundación Francisco Soria Melguizo (Madrid, Spain).. Finançat per La Fundació La Marató de TV3, projecte amb codi 202108-30/-31. COVIDPONENT is funded by Institut Català de la Salut and Gestió de Serveis Sanitaris. MM is the recipient of a predoctoral fellowship (PFIS: FI21/00187) from Instituto de Salud Carlos III. MCGH is the recipient of a predoctoral fellowship from “University of Lleida”. DdGC has received financial support from Instituto de Salud Carlos III (Miguel Servet 2020: CP20/00041), co-funded by the European Social Fund (ESF)/“Investing in your future”. ENL and GL were funded by COVID1005 and ACT210085 from National Agency of Investigation & Development (ANID), Chile."Article signat per 27 autors/es: María C. García-Hidalgo, Jessica González, Iván D. Benítez, Paola Carmona, Sally Santisteve, Manel Pérez-Pons, Anna Moncusí-Moix, Clara Gort-Paniello, Fátima Rodríguez-Jara, Marta Molinero, Thalia Belmonte, Gerard Torres, Gonzalo Labarca, Estefania Nova-Lamperti, Jesús Caballero, Jesús F. Bermejo-Martin, Adrián Ceccato, Laia Fernández-Barat, Ricard Ferrer, Dario Garcia-Gasulla, Rosario Menéndez, Ana Motos ,Oscar Peñuelas, Jordi Riera, Antoni Torres, Ferran Barbé, David de Gonzalo-Calvo & on behalf of the CIBERESUCICOVID Project (COV20/00110 ISCIII)"Postprint (published version
Bronchial Aspirate-Based Profiling Identifies MicroRNA Signatures Associated With COVID-19 and Fatal Disease in Critically Ill Patients
Background: The pathophysiology of COVID-19-related critical illness is not completely understood. Here, we analyzed the microRNA (miRNA) profile of bronchial aspirate (BAS) samples from COVID-19 and non-COVID-19 patients admitted to the ICU to identify prognostic biomarkers of fatal outcomes and to define molecular pathways involved in the disease and adverse events.
Methods: Two patient populations were included (n = 89): (i) a study population composed of critically ill COVID-19 and non-COVID-19 patients; (ii) a prospective study cohort composed of COVID-19 survivors and non-survivors among patients assisted by invasive mechanical ventilation (IMV). BAS samples were obtained by bronchoaspiration during the ICU stay. The miRNA profile was analyzed using RT-qPCR. Detailed biomarker and bioinformatics analyses were performed.
Results: The deregulation in five miRNA ratios (miR-122-5p/miR-199a-5p, miR-125a-5p/miR-133a-3p, miR-155-5p/miR-486-5p, miR-214-3p/miR-222-3p, and miR-221-3p/miR-27a-3p) was observed when COVID-19 and non-COVID-19 patients were compared. In addition, five miRNA ratios segregated between ICU survivors and nonsurvivors (miR-1-3p/miR-124-3p, miR-125b-5p/miR-34a-5p, miR-126-3p/miR-16-5p, miR-199a-5p/miR-9-5p, and miR-221-3p/miR-491-5p). Through multivariable analysis, we constructed a miRNA ratio-based prediction model for ICU mortality that optimized the best combination of miRNA ratios (miR-125b-5p/miR-34a-5p, miR-199a-5p/miR-9-5p, and miR-221-3p/miR-491-5p). The model (AUC 0.85) and the miR-199a-5p/miR-9-5p ratio (AUC 0.80) showed an optimal discrimination value and outperformed the best clinical predictor for ICU mortality (days from first symptoms to IMV initiation, AUC 0.73). The survival analysis confirmed the usefulness of the miRNA ratio model and the individual ratio to identify patients at high risk of fatal outcomes following IMV initiation. Functional enrichment analyses identified pathological mechanisms implicated in fibrosis, coagulation, viral infections, immune responses and inflammation.
Conclusions: COVID-19 induces a specific miRNA signature in BAS from critically ill patients. In addition, specific miRNA ratios in BAS samples hold individual and collective potential to improve risk-based patient stratification following IMV initiation in COVID-19-related critical illness. The biological role of the host miRNA profiles may allow a better understanding of the different pathological axes of the disease.We want particularly to acknowledge the patients, Biobank IdISBa and CIBERES Pulmonary Biobank Consortium (PT17/0015/0001), a member of the Spanish National Biobanks Network financed by the Carlos III Health Institute, with the participation of the Units of Intensive Care, Clinical Analysis and Pulmonology of Hospital Universitario Son Espases and Hospital Son Llatzer for their collaboration. This work was also supported by IRBLleida Biobank (B.0000682) and Plataforma Biobancos PT17/0015/0027/.Peer Reviewed"Article signat per 25 autors/es: Marta Molinero, Iván D. Benítez, Jessica González, Clara Gort-Paniello, Anna Moncusí-Moix, Fátima Rodríguez-Jara, María C. García-Hidalgo, Gerard Torres, J. J. Vengoechea, Silvia Gómez, Ramón Cabo, Jesús Caballero, Jesús F. Bermejo-Martin, Adrián Ceccato, Laia Fernández-Barat, Ricard Ferrer, Dario Garcia-Gasulla, Rosario Menéndez, Ana Motos, Oscar Peñuelas, Jordi Riera, Antoni Torres, Ferran Barbé and David de Gonzalo-Calvo* on behalf of the CIBERESUCICOVID Project (COV20/00110 ISCIII)"Postprint (published version
Optical Characterization of a Single Quantum Emitter Based on Vanadium Phthalocyanine Molecules
Single quantum emitters play a fundamental role in the development of quantum
technologies such as quantum repeaters, and quantum information processing.
Isolating individual molecules with stable optical emission is an essential
step for these applications, specially for those molecules that present large
coherence times at room temperature. Among them, vanadium-oxide phthalocyanine
(VOPc) molecules stand out as promising candidates due to their large coherence
times measured in ensemble. However, the optical properties of individual
molecules have not yet been reported. Here we show that single VOPc molecules
with stable optical properties at room temperature can be isolated. We find
that the optical response of the molecule under laser illumination of different
polarization agrees well with a system having pyramidal C symmetry.
Furthermore, the molecule reveals a non-radiative transition rate that depends
on the excitation wavelength when its lifetime is interrogated. We provide
theoretical calculations that support our experimental findings and provide
insight to the role of phonons and internal electronic structure of the
molecule. These results demonstrate that this single paramagnetic molecule can
function as a single quantum emitter while displaying optical stability under
ambient conditions to have their intrinsic properties investigated
Effects of game location, team quality and final outcome on game-related statistics in professional handball close games
The aim of this study was to identify the effects of team quality, game location and final outcome on handball performance indicators during close games. The sample consisted of 126 close games (goal
differences of 1.98±1.37) from the Spanish Professional Men’s Handball League (2012/13). Factor analysis identified six factors: Factor 1 – successful 6m and 7m shots and unsuccessful 6m, 7m and 9m shots; Factor 2 – successful 6m and 9m shots and unsuccessful saves from 9m shots; Factor 3 – successful and unsuccessful counter-attack shots, assists, blocks and recovered balls; Factor 4 – successful and unsuccessful saves from 7m shots; Factor 5 – successful and unsuccessful saves from counter-attack shots; Factor 6 – yellow cards and successful saves from 6m shots. A mixed linear model identified the effects of team quality, game location and game outcome on the previously identified factors. Game location effects were significant for Factor 3, with higher values for home teams. Game outcome main effects were identified for Factors 3, 5 and 6, with teams having higher values when winning. The team quality was significant for Factor 3, with higher values for superior teams. The team quality x game outcome and team quality x game location interactions were significant for Factor 3. The game location x game outcome interaction was significant for Factors 2 and 3. These findings can contribute to a better understanding of the situational variables’ determinants of elite handball performances, helping the coaches to prepare the players accordingly
Exposure to Morphine and Cocaine Modify the Transcriptomic Landscape in Zebrafish Embryos
Morphine and other opioid analgesics are the drugs of election to treat moderate-to-severe pain, and they elicit their actions by binding to the opioid receptors. Cocaine is a potent inhibitor of dopamine, serotonin, and noradrenaline reuptake, as it blocks DAT, the dopamine transporter, causing an increase in the local concentration of these neurotransmitters in the synaptic cleft. The molecular effects of these drugs have been studied in specific brain areas or nuclei, but the systemic effects in the whole organism have not been comprehensively analyzed. This study aims to analyze the transcriptomic changes elicited by morphine (10 uM) and cocaine (15 uM) in zebrafish embryos. An RNAseq assay was performed with tissues extracts from zebrafish embryos treated from 5 hpf (hours post fertilization) to 72 hpf, and the most representative deregulated genes were experimentally validated by qPCR. We have found changes in the expression of genes related to lipid metabolism, chemokine receptor ligands, visual system, hemoglobins, and metabolic detoxification pathways. Besides, morphine and cocaine modified the global DNA methylation pattern in zebrafish embryos, which would explain the changes in gene expression elicited by these two drugs of abuse.post-print3160 K
Exploiting visual saliency for assessing the impact of car commercials upon viewers
Content based video indexing and retrieval (CBVIR) is a lively area of research which focuses on automating the indexing, retrieval and management of videos. This area has a wide spectrum of promising applications where assessing the impact of audiovisual productions emerges as a particularly interesting and motivating one. In this paper we present a computational model capable to predict the impact (i.e. positive or negative) upon viewers of car advertisements videos by using a set of visual saliency descriptors. Visual saliency provides information about parts of the image perceived as most important, which are instinctively targeted by humans when looking at a picture or watching a video. For this reason we propose to exploit visual information, introducing it as a new feature which reflects high-level semantics objectively, to improve the video impact categorization results. The suggested salience descriptors are inspired by the mechanisms that underlie the attentional abilities of the human visual system and organized into seven distinct families according to different measurements over the identified salient areas in the video frames, namely population, size, location, geometry, orientation, movement and photographic composition. Proposed approach starts by computing saliency maps for all the video frames, where two different visual saliency detection frameworks have been considered and evaluated: the popular graph based visual saliency (GBVS) algorithm, and a state-of-the-art DNN-based approach.This work has been partially supported by the National Grants RTC-2016-5305-7 and TEC2014-53390-P of the Spanish Ministry of Economy and Competitiveness.Publicad
Assessment of medical management in Coronary Type 2 Diabetic patients with previous percutaneous coronary intervention in Spain: A retrospective analysis of electronic health records using Natural Language Processing
Coronary heart disease; Type 2 diabetes; Electronic medical recordsEnfermedad coronaria; Diabetes tipo 2; Registros médicos electrónicosMalaltia coronària; Diabetis tipus 2; Registres mèdics electrònicsIntroduction and objectives
Patients with type 2 diabetes (T2D) and stable coronary artery disease (CAD) previously revascularized with percutaneous coronary intervention (PCI) are at high risk of recurrent ischemic events. We aimed to provide real-world insights into the clinical characteristics and management of this clinical population, excluding patients with a history of myocardial infarction (MI) or stroke, using Natural Language Processing (NLP) technology.
Methods
This is a multicenter, retrospective study based on the secondary use of 2014–2018 real-world data captured in the Electronic Health Records (EHRs) of 1,579 patients (0.72% of the T2D population analyzed; n = 217,632 patients) from 12 representative hospitals in Spain. To access the unstructured clinical information in EHRs, we used the EHRead® technology, based on NLP and machine learning. Major adverse cardiovascular events (MACE) were considered: MI, ischemic stroke, urgent coronary revascularization, and hospitalization due to unstable angina. The association between MACE rates and the variables included in this study was evaluated following univariate and multivariate approaches.
Results
Most patients were male (72.13%), with a mean age of 70.5±10 years. Regarding T2D, most patients were non-insulin-dependent T2D (61.75%) with high prevalence of comorbidities. The median (Q1-Q3) duration of follow-up was 1.2 (0.3–4.5) years. Overall, 35.66% of patients suffered from at least one MACE during follow up. Using a Cox Proportional Hazards regression model analysis, several independent factors were associated with MACE during follow up: CAD duration (p < 0.001), COPD/Asthma (p = 0.021), heart valve disease (p = 0.031), multivessel disease (p = 0.005), insulin treatment (p < 0.001), statins treatment (p < 0.001), and clopidogrel treatment (p = 0.039).
Conclusions
Our results showed high rates of MACE in a large real-world series of PCI-revascularized patients with T2D and CAD with no history of MI or stroke. These data represent a potential opportunity to improve the clinical management of these patients.This study was funded by AstraZeneca Spain and sponsored by the Spanish Society of Cardiology
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