Sphere rolling on the surface of a cone

We analyse the motion of a sphere that rolls without slipping on a conical surface having its axis in the direction of the constant gravitational field of the Earth. This nonholonomic system admits a solution in terms of quadratures. We exhibit that the only circular of the system orbit is stable and furthermore show that all its solutions can be found using an analogy with central force problems. We also discuss the case of motion with no gravitational field, that is, of motion on a freely falling cone.Comment: 12 pages, 2 figures, to be published in Eur J Phy

The Lysholm score: Cross cultural validation and evaluation of psychometric properties of the Spanish version

This study aims at assessing the validity and reliability of the Spanish version of the Lysholm score, a widely used instrument for assessing knee function and activity level after ligament injuries. Ninety-five participants (67.4% male, 22±5 years) completed the questionnaire twice within 7 days and a subsample of 42 participants completed a test-retest reliability. Reliability, validity and feasibility psychometric properties were studied. The validity of the questionnaire was analysed using ceiling and floor effects. Factor structure and construct validity were analysed with the SF-36, the Hip and Knee Questionnaire (HKQ) and one leg jump test (OLJT). Criterion validity with the SF-36 Physical State was moderate (r = 0.50 and p<0.01), poor and inverse relationship (r = -0.31, p<0.01) with HKQ and positive moderate (r = 0.59, p<0.01) with OLJT. Measurement error from MDC90 was 3.9%. Exploratory factor analysis demonstrated a one-factor solution explaining 51.5% of total variance. The x2 test for the one-factor model was significant (x2 = 29.58, df = 20, p < 0.08). Test-retest reliability level was high (ICC2.1 = 0.92, p<0.01) and also the internal consistency (α = 0.77). The Spanish Lysholm score demonstrated that it is a reliable and valid instrument that can be used to assess knee function after ligament injuries.This study takes place thanks to the additional funding from the University of Granada, Plan Propio de Investigación 2016, Excellence actions: Units of Excellence; Unit of Excellence on Exercise and Health (UCEES)

Which occupational risk factors are associated with burnout in nursing? A meta-analytic study

Numerous empirical studies have suggested a link between occupational factors and the burnout syndrome. The effect sizes of the association reported vary widely in nursing professionals. The objective of this research was to assess the influence of five occupational factors (job seniority, professional experience, job satisfaction, specialization and work shift) on the three burnout dimensions (emotional exhaustion, depersonalization and personal accomplishment) in nursing. We conducted a meta-analysis with a total of 81 studies met to our inclusion criteria: 31 on job seniority; 29 on professional experience; 37 on job satisfaction; 4 on specialization; and 6 on work shift. The mean effect sizes found suggest that job satisfaction and, to a lesser extent, specialization were important factors influencing the burnout syndrome. The heterogeneity analysis showed that there was a great variability in all the estimates of the mean effect size. Various moderators were found to be significant in explaining the association between occupational factors and burnout. In conclusion, it is important to prevent the substantive moderators that are influencing these associations. The improved methodological variables explain most of the contradictory results found in previous research on this field.Numerosos estudios sugieren la relación entre el síndrome de burnout y algunas variables ocupacionales e informan de diversos tamaños del efecto en sus asociaciones, en profesionales de Enfermería. El objetivo de este trabajo es estudiar la influencia de cinco variables ocupacionales (antigüedad en el puesto, antigüedad en la profesión, satisfacción laboral, especialización y turno laboral) y las tres dimensiones del síndrome (cansancio emocional, despersonalización y realización personal) en enfermeros. En este trabajo se realizó un meta-análisis de 81 estudios que cumplían los criterios de inclusión establecidos: 31 sobre antigüedad en el puesto, 29 en experiencia profesional, 37 relacionados con satisfacción laboral, 4 con especialización y 6 con turno laboral. Los tamaños del efecto medio indican que la satisfacción laboral y, en menor medida, la especialización eran factores importantes que influye en el burnout. La heterogeneidad encontrada en las estimaciones de los tamaños del efecto hace necesario realizar el análisis de variables moderadoras, obteniéndose que algunos moderadores son de gran interés en la explicación de las asociaciones. En conclusión, sería importante prevenir las variables moderadoras sustantivas que median estas asociaciones. Los aspectos metodológicos deberían ser mejorados pues parecen explicar algunos de los resultados contradictorios que se encuentran en las investigaciones en este ámbito.Open Access funded by Asociación Española de Psicología ConductualExcellence Research Projects P07HUM-02529 and P11HUM-7771 (Junta de Andalucía-Spain)

ACORDE a Cosmic Ray Detector for ALICE

ACORDE is one of the ALICE detectors, presently under construction at CERN. It consists of an array of plastic scintillator counters placed on the three upper faces of the ALICE magnet. It will act as a cosmic ray trigger, and, together with other ALICE sub-detectors, will provide precise information on cosmic rays with primary energies around $10^{15} \div 10^{-17}$ eV. Here we describe the design review of ACORDE along with the present status and integration into ALICE.Comment: 2 pages, 2 figures. Conference Proceeding of the X Pisa Meeting on Advanced Detectors, to be published in a special issue of Nuclear Instruments and Method

Implementació de GeoNetwork per a la gestió de metadades del Centre Tecnològic Forestal de Catalunya

El present projecte ha consistit en implementar un SIG corporatiu per a la gestió de la informació de dades del Centre Tecnològic Forestal de Catalunya. La finalitat és la d'estructurar i organitzar aquesta informació que se'n deriva per a que pugui ser consultada fàcilment i de manera molt dinàmica. Un cop el sistema d'informació contenia les dades pròpies del CTFC es van afegir més metadades al sistema d'informació mitjançant connexions de harvesting, GeoServer i protocol FTPThis project is based on developing a corporative GIS in order to manage CTFC's (Centre Tecnològic de Catalunya) data. The aim was to organize and structure these data so that users would be able to consult all the projects carried out by CTFC in an easy and dynamic way. Once all the relevant CTFC's data was in the system, more data coming from harvesting connections, such as GeoServer and FTP (File Transfer Protocol), was introduce

Preventing and addressing the stress reactions of health care workers caring for patients with COVID-19: Development of a digital platform (Be + against COVID)

Background: COVID-19 became a major public health concern in March 2020. Due to the high rate of hospitalizations for COVID-19 in a short time, health care workers and other involved staff are subjected to a large workload and high emotional distress. Objective: The objective of this study is to develop a digital tool to provide support resources that might prevent and consider acute stress reactions in health care workers and other support staff due to the COVID-19 pandemic. Methods: The contents of the digital platform were created through an evidence-based review and consensus conference. The website was built using the Google Blogger tool. The Android version of the app was developed in the Java and XML languages using Android Studio version 3.6, and the iOS version was developed in the Swift language using Xcode version 11.5. The app was evaluated externally by the Andalusian Agency for Healthcare Quality. Results: We detected the needs and pressing situations of frontline health care workers, and then, we proposed a serial of recommendations and support resources to address them. These resources were redesigned using the feedback received. A website in three different languages (Spanish, English, and Portuguese) and a mobile app were developed with these contents, and the AppSaludable Quality Seal was granted to the app. A specific self-report scale to measure acute stress and additional tools were included to support the health care workforce. This instrument has been used in several Latin American countries and has been adapted considering cultural differences. The resources section of the website was the most visited with 18, 516 out of 68, 913 (26.9%) visits, and the “Self-Report Acute Stress Scale” was the most visited resource with 6468 out of 18, 516 (34.9%) visits. Conclusions: The Be + against COVID platform (website and app) was developed and launched to offer a pool of recommendations and support resources, which were specifically designed to protect the psychological well-being and the work morale of health care workers. This is an original initiative different from the usual psychological assistance hotlines

Should emergence models for Lolium rigidum be changed throughout climatic conditions? The case of Spain

Lolium rigidum Gaudin is a troublesome weed worldwide, and its distribution may increase due to climate change. It has become resistant to several herbicides and, therefore, its control is problematic. On the other hand, its seed biology, with little dormancy and short-term viability, can play a major role in reducing its seed bank, which would improve control of this weed. For this reason, knowledge of the emergence patterns of this species entails improvements for its management. In this work seeds from one population of L. rigidum, collected in Northeastern Spain, were distributed and sown in 11 sites across Spain, and its emergence was followed every 2–7 days for two growing seasons (2016-17 and 2017–18). These emergence sequences were compared with previously published thermal time and hydrothermal time based models, and new models were developed afterwards. The hydrothermal time based model did not significantly improve models based solely on thermal time. The accuracy of these newly developed models varied from site to site, but in general, they worked better for Northern locations than for Southern locations. Thus, the experimental sites were split between North and South, and specific models for each region were developed. The model developed for Northern sites worked very well, but the one for Southern sites needs improvement. This works reveals that, with regard to this weed species, probably different models should be developed for different climatic conditions. The model developed with data from Northern sites should be validated with local populations, while the one developed with data from Southern sites will probably need to be revised or newly developed with data from more Southern populations.The group from the University of Lleida-Agrotecnio would also like to thank the Spanish Goverment for partial funding, through project AGL2017-83325-C4-2-R (AEI/FEDER/UE)

Modeling the emergence of North African Knapweed (Centaurea diluta), an increasingly troublesome weed in Spain

North African knapweed (Centaurea diluta Aiton) is an annual weed that is widespread in southern Spain and is of increasing concern in dryland cropping systems. Despite its expanding range in Spain, there is limited information on the emergence timing and pattern of this species, which is critical for developing more timely and effective management strategies. Therefore, there is a need to develop simple and reliable models to predict the timing and emergence of this annual weed under dryland conditions. A multi-location field experiment was established across Spain in 2016-2017 to assess the emergence of C. diluta. At each of 11 locations, seeds were sown in the fall, and emergence was recorded. Overall emergence averaged 39% in the first year across all sites and 11% in the second year. In both years, the main emergence flush occurred at beginning of the growing season. The three-parameter Weibull function best described seedling emergence of C. diluta. Emergence models were developed based on thermal time (TT) and hydrothermal time (HTT) and showed high predictability, as evidenced by root mean square error prediction (RMSEP) values of 10.8 and 10.7, respectively. The three cardinal points were established for TT and HHT at 0.5 ºC, 10 ºC and 35 ºC for base, optimal and ceiling temperature, while base water potential was estimated at -0.5MPa.We would like to thank Cátedra Adama and the Spanish Weed Science Society (SEMh) for providing financial support for this project. We are grateful to the many students and technicians who assisted with field work at the different experimental locations. We would like to thank the Spanish Goverment for partial funding, through project AVA 2019.020 "Advances in Technological Research in Winter Cereals: Genetic Improvement and Sustainable Management" financed with FEDER funds (80%). Also, Joel Torra acknowledges support from the Spanish Ministry of Science, Innovation and Universities (grant Ramon y Cajal RYC2018-023866-I)

ODS ferritic steels obtained from gas atomized powders through the STARS processing route: Reactive synthesis as an alternative to mechanical alloying

Oxide Dispersion Strengthened Ferritic Stainless Steels (ODS FS) are candidate materials for structural components in fusion reactors. Their ultrafine microstructure and the presence of a very stable dispersion of Y-Ti-O nanoclusters provide reasonable fracture toughness, high mechanical and creep strength, and resistance to radiation damage at the operation temperature, up to about 750 °C. An innovative route to produce ODS FS with composition Fe-14Cr-2W-0.3Ti-0.3Y2O3 (wt.%), named STARS (Surface Treatment of gas Atomized powder followed by Reactive Synthesis), is presented. This route avoids the mechanical alloying (MA) of the elemental or prealloyed powders with yttria to dissolve the yttrium in the ferritic matrix. In this study, starting powders containing Ti and Y are obtained by gas atomization at laboratory and industrial scale. Then, a metastable Cr- and Fe- rich oxide layer is formed on the surface of the powder particles. During consolidation by HIP the metastable oxide layer at Prior Particle Boundaries (PPBs) dissociates, the oxygen diffuses towards saturated solutions or metallic Ti- and Y-rich particles, and Y-Ti-O nano-oxides (mainly Y2TiO5) precipitate in the ferritic matrix. Detailed Microstructural characterization by X-ray Photoelectron Spectroscopy (XPS), X-ray Absorption Spectroscopy (XAS), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of powders and consolidated materials is presented and correlated with mechanical behaviour