210 research outputs found
Growth and Pollution Convergence: Theory and Evidence
Stabilizing pollution levels in the long run is a pre-requisite for sustainable growth. We develop a neoclassical growth model with endogenous emission reduction predicting that, along optimal sustainable paths, pollution growth rates are (i) positively related to output growth (scale effect) and (ii) negatively related to emission levels (defensive effect). This dynamic law reduces to a convergence equation that is empirically tested for two major and regulated air pollutants - sulfur oxides and nitrogen oxides - with a panel of 25 European countries spanning the years 1980-2005. Traditional parametric models are rejected by the data. More flexible regression techniques confirm the existence of both the scale and the defensive effect, supporting the model predictions.Air pollution, convergence, economic growth, nonparametric regressions
Growth and the pollution convergence hypothesis: a nonparametric approach
Abstract The pollution-convergence hypothesis is formalized in a neoclassical growth model with optimal emissions reduction: pollution growth rates are positively correlated with output growth (scale effect) but negatively correlated with emission levels (defensive effect). This dynamic law is empirically tested for two major and regulated air pollutants -nitrogen oxides (NOX) and sulfur oxides (SOX) -with a panel of 25 European countries spanning over years . Traditional parametric models are rejected by the data. However, more flexible regression techniques -semiparametric additive specifications and fully nonparametric regressions with discrete and continuous factors -confirm the existence of the predicted positive and defensive effects. By analyzing the spatial distributions of per capita emissions, we also show that cross-country pollution gaps have decreased over the period for both pollutants and within the Eastern as well as the Western European areas. A Markov modeling approach predicts further cross-country absolute convergence, in particular for SOX. The latter results hold in the presence of spatial non-convergence in per capita income levels within both regions. JEL Classification numbers: C14, C23, Q5
Self-passivating W-Cr-Y alloys: characterization and testing
The use of self-passivating tungsten alloys for the first wall armor of future fusion reactors is advantageous
concerning safety issues in comparison with pure tungsten. Bulk W-10Cr-0.5Y alloy manufactured by mechanical
alloying followed by HIP resulted in a fully dense material with grain size around 100 nm and a dispersion of Y-rich
oxide nanoparticles located at the grain boundaries. An improvement in flexural strength and fracture toughness was
observed with respect to previous works. Oxidation tests under isothermal and accident-like conditions revealed a very
promising oxidation behavior for the W-10Cr-0.5Y alloy. Thermo-shock tests at JUDITH-1 to simulate ELM-like loads
resulted in a crack network at the surface with roughness values lower than those of a pure W reference material. An
additional thermal treatment at 1550 °C improves slightly the oxidation and thermo-shock resistance of the alloy
Active Trigger Points in the Cervical Musculature Determine Altered Activation of Superficial Neck and Extensor Muscles in Women with Migraine
Headache: What to ask, how to examine, and which scales to use. Recommendationsof the Spanish Society of Neurology’s Headache Study Group
Introducción: La cefalea es el motivo de consulta neurológico más prevalente en los distintos niveles asistenciales, donde la anamnesis y exploración son primordiales para realizar un diagnóstico y tratamiento adecuados. Con la intención de unificar la atención de esta patología, el Grupo de Estudio de Cefalea de la Sociedad Española de Neurología (GECSEN) ha decidido elaborar unas recomendaciones consensuadas para mejorar y garantizar una adecuada asistencia en atención primaria, urgencias y neurología. Metodología: El documento es práctico, sigue el orden de la dinámica de actuación durante una consulta: anamnesis, escalas que cuantifican el impacto y la discapacidad y exploración. Además, finaliza con pautas para realizar un seguimiento adecuado y un manejo de las expectativas del paciente con el tratamiento pautado.Conclusiones: Esperamos ofrecer una herramienta que mejore la atención al paciente con cefalea para garantizar una asistencia adecuada y homogénea a nivel nacional.Introduction: Headache is the most common neurological complaint at the different levelsof the healthcare system, and clinical history and physical examination are essential in thediagnosis and treatment of these patients. With the objective of unifying the care given topatients with headache, the Spanish Society of Neurology’s Headache Study Group (GECSEN)has decided to establish a series of consensus recommendations to improve and guaranteeadequate care in primary care, emergency services, and neurology departments.Methods: With the aim of creating a practical document, the recommendations follow thedynamics of a medical consultation: clinical history, physical examination, and scales quantif-ying headache impact and disability. In addition, we provide recommendations for follow-upand managing patients’ expectations of the treatment.Conclusions: With this tool, we aim to improve the care given to patients with headache inorder to guarantee adequate, homogeneous care across Spain
Artificial neural networks training acceleration through network science strategies
The development of deep learning has led to a dramatic increase in the number of applications of artificial intelligence. However, the training of deeper neural networks for stable and accurate models translates into artificial neural networks (ANNs) that become unmanageable as the number of features increases. This work extends our earlier study where we explored the acceleration effects obtained by enforcing, in turn, scale freeness, small worldness, and sparsity during the ANN training process. The efficiency of that approach was confirmed by recent studies (conducted independently) where a million-node ANN was trained on non-specialized laptops. Encouraged by those results, our study is now focused on some tunable parameters, to pursue a further acceleration effect. We show that, although optimal parameter tuning is unfeasible, due to the high non-linearity of ANN problems, we can actually come up with a set of useful guidelines that lead to speed-ups in practical cases. We find that significant reductions in execution time can generally be achieved by setting the revised fraction parameter (ζ) to relatively low values
Proto-oncogene HER-2 in normal, dysplastic and tumorous feline mammary glands: an immunohistochemical and chromogenic in situ hybridization study
<p>Abstract</p> <p>Background</p> <p>Feline mammary carcinoma has been proposed as a natural model of highly aggressive, hormone-independent human breast cancer. To further explore the utility of the model by adding new similarities between the two diseases, we have analyzed the oncogene HER-2 status at both the protein and the gene levels.</p> <p>Methods</p> <p>Formalin-fixed, paraffin-embedded tissue samples from 30 invasive carcinomas, 7 benign lesions and two normal mammary glands were analyzed. Tumour features with prognostic value were recorded. The expression of protein HER-2 was analyzed by immunohistochemistry and the number of gene copies by means of DNA chromogenic <it>in situ </it>hybridization.</p> <p>Results</p> <p>Immunohistochemical HER-2 protein overexpression was found in 40% of feline mammary carcinomas, a percentage higher to that observed in human breast carcinoma. As in women, feline tumours with HER-2 protein overexpression had pathological features of high malignancy. However, amplification of HER-2 was detected in 16% of carcinomas with protein overexpression, a percentage much lower than that observed in their human counterpart.</p> <p>Conclusion</p> <p>Feline mammary carcinoma would be a suitable natural model of that subset of human breast carcinomas with HER-2 protein overexpression without gene amplification.</p
Semiautomatic Assessment of the Terminal Ileum and Colon in Patients with Crohn Disease Using MRI (the VIGOR++ Project)
Rationale and Objectives: The objective of this study was to develop and validate a predictive magnetic resonance imaging (MRI) activity score for ileocolonic Crohn disease activity based on both subjective and semiautomatic MRI features. Materials and Methods: An MRI activity score (the “virtual gastrointestinal tract [VIGOR]” score) was developed from 27 validated magnetic resonance enterography datasets, including subjective radiologist observation of mural T2 signal and semiautomatic measurements of bowel wall thickness, excess volume, and dynamic contrast enhancement (initial slope of increase). A second subjective score was developed based on only radiologist observations. For validation, two observers applied both scores and three existing scores to a prospective dataset of 106 patients (59 women, median age 33) with known Crohn disease, using the endoscopic Crohn's Disease Endoscopic Index of Severity (CDEIS) as a reference standard. Results: The VIGOR score (17.1 × initial slope of increase + 0.2 × excess volume + 2.3 × mural T2) and other activity scores all had comparable correlation to the CDEIS scores (observer 1: r = 0.58 and 0.59, and observer 2: r = 0.34–0.40 and 0.43–0.51, respectively). The VIGOR score, however, improved interobserver agreement compared to the other activity scores (intraclass correlation coefficient = 0.81 vs 0.44–0.59). A diagnostic accuracy of 80%–81% was seen for the VIGOR score, similar to the other scores. Conclusions: The VIGOR score achieves comparable accuracy to conventional MRI activity scores, but with significantly improved reproducibility, favoring its use for disease monitoring and therapy evaluation
Transcriptomics of In Vitro Immune-Stimulated Hemocytes from the Manila Clam Ruditapes philippinarum Using High-Throughput Sequencing
The Manila clam (Ruditapes philippinarum) is a worldwide cultured bivalve species with important commercial value. Diseases affecting this species can result in large economic losses. Because knowledge of the molecular mechanisms of the immune response in bivalves, especially clams, is scarce and fragmentary, we sequenced RNA from immune-stimulated R. philippinarum hemocytes by 454-pyrosequencing to identify genes involved in their immune defense against infectious diseases
Diplopia is frequent and associated with motor and non-motor severity in parkinson's disease : Results from the COPPADIS cohort at 2-year follow-up
Background and objective: Diplopia is relatively common in Parkinson's disease (PD) but is still understudied. Our aim was to analyze the frequency of diplopia in PD patients from a multicenter Spanish cohort, to compare the frequency with a control group, and to identify factors associated with it. Patients and Methods: PD patients who were recruited from January 2016 to November 2017 (baseline visit; V0) and evaluated again at a 2-year ± 30 days follow-up (V2) from 35 centers of Spain from the COPPADIS cohort were included in this longitudinal prospective study. The patients and controls were classified as "with diplopia" or "without diplopia" according to item 15 of the Non-Motor Symptoms Scale (NMSS) at V0, V1 (1-year ± 15 days), and V2 for the patients and at V0 and V2 for the controls. Results: The frequency of diplopia in the PD patients was 13.6% (94/691) at V0 (1.9% in controls [4/206]; p < 0.0001), 14.2% (86/604) at V1, and 17.1% (86/502) at V2 (0.8% in controls [1/124]; p < 0.0001), with a period prevalence of 24.9% (120/481). Visual hallucinations at any visit from V0 to V2 (OR = 2.264; 95%CI, 1.269-4.039; p = 0.006), a higher score on the NMSS at V0 (OR = 1.009; 95%CI, 1.012-1.024; p = 0.015), and a greater increase from V0 to V2 on the Unified Parkinson's Disease Rating Scale-III (OR = 1.039; 95%CI, 1.023-1.083; p < 0.0001) and Neuropsychiatric Inventory (OR = 1.028; 95%CI, 1.001-1.057; p = 0.049) scores were independent factors associated with diplopia (R = 0.25; Hosmer and Lemeshow test, p = 0.716). Conclusions: Diplopia represents a frequent symptom in PD patients and is associated with motor and non-motor severity
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