2,644 research outputs found

    Liner radius fluctuations in a high-gain Cherenkov free-electron laser

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    Phase shifts in the propagating electromagnetic field of a Cherenkov free-electron laser (CFEL) can affect its gain. The phase velocity of an electromagnetic wave varies, for example, when the lined waveguide is inhomogeneous along its length. In this paper, we study quantitatively the saturated power of a particular CFEL at both weak and strong electron-beam pumping when the inner radius of the liner contains fluctuations along the waveguide. We show that the gain bandwidth of the CFEL is substantially broadened when the CFEL is pumped with a high-current beam. We also show that the design of a CFEL needs to include optimization with respect to sensitivity to liner fluctuations, especially for weakly pumped CFELs, that is, CFELs that use a low-current electron-beam density. This optimization can be relaxed for more strongly pumped CFELs

    Relation and effect of resilience on burnout in nurses: A literature review and meta-analysis

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    Aim: To study the relation between burnout and resilience and to identify the profile of nurses presenting this quality. Background and Introduction: Healthcare professionals are subject to high rates of burnout. Resilience could be an important factor in preventing or alleviating this condition. Methods: The PubMed, ProQuest, Scopus and ScienceDirect databases were consulted in February 2022 using the equation ‘burnout AND resilience AND nurs*’. The inclusion criteria applied were that the texts should describe quantitative studies, be published in English or Spanish, in any year, and be directly related to the question considered. The meta-analysis was performed using StatsDirect statistical software. Results: Analysis of the 29 studies shows that among the dimensions of burnout, nurses are especially prone to emotional exhaustion, and are less affected by depersonalisation and low personal accomplishment. Those who score highly for resilience tend to have longer service experience, acceptable salaries and lesswork overload.Meta-analysis reveals an inverse correlation between resilience and burnout (r = −0.41; n = 2750), exhaustion (r=−0.27; n = 6966) and depersonalisation (r=−0.23; n = 6115). Conclusion: Many nurses present low levels of resilience and suffer from burnout syndrome. The application of programmes to enhance their resilience would help prevent burnout and optimise the potential to provide quality health care. Implications for nursing and health policy: Resilience is inversely correlated with burnout, depersonalisation and emotional exhaustion. Accordingly, healthcare organisations should develop and implement evidence-based programmes to foster nurses’ resilience and thus reduce their susceptibility to burnout.FEDER/Consejería de Universidad, Investigación e Innovación de la Junta de Andalucía, Grant/Award Number: Project: P20_0062

    An Explanatory Model of Potential Changes in Burnout Diagnosis According to Personality Factors in Oncology Nurses

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    Burnout in a hospital oncology service takes place when there is a high level of interaction between nurses and patients. The aim of the present study is to identify models that will enable us to accurately classify a person at a given level within each of the three dimensions of burnout, according to the values presented for personality related explanatory variables, for a sample of 96 oncology nurses working in the regional health service of Andalusia (Spain). A quantitative, crosscutting, multicentre, descriptive study was designed, and for this purpose data on sociodemographic and personality variables and on the three dimensions of burnout were compiled. Three categorical-response logit ordinal models were used and the prognostic ratios for each level were obtained, with respect to every other level, according to possible changes in the explanatory variables considered. Certain personality factors are associated with one or more dimensions of burnout syndrome. Thus, nurses are more likely to develop high levels of burnout if they present high levels of neuroticism and low levels of friendliness and responsibility. Further research in this field is needed to confirm and extend these findings.This research was funded by Excellence Research Project P11HUM-7771 (Junta de Andalucía, Spain) and by Research Project mP_BS_6 (CEI BioTic Granada and Ministerio de Ciencia e Innovación, Spain)

    Evaluation of Convergent, Discriminant, and Criterion Validity of the Cuestionario Burnout Granada-University Students

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    Supplementary Materials: The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/math11153315/s1.Burnout is a health problem that affects professionals and students or professionals in training, especially those in health areas. For this reason, it is necessary that it is properly identified to prevent the impact it can have on the work and personal areas of the people who suffer from it. The aim of this work is to study the convergent, discriminant, and criterion validity of the Cuestionario Burnout Granada-University Students. The sample consisted of 463 undergraduate nursing students, selected by non-probabilistic convenience sampling, who participated voluntarily and anonymously in the study. The mean age of the participants was 21.9 (5.12) years, mostly female (74.1%), single (95.8%), and childless (95.6%). Information was collected face-to-face, and the instruments were completed on paper. Comparisons were made in the three dimensions of burnout of the CBG-USS between students with and without burnout, finding statistically significant differences in all three dimensions: Emotional Exhaustion (p < 0.001, d = 0.674), Cynicism (p < 0.001, d = 0.479), and Academic Efficacy (p < 0.001, d = -0.607). The Cuestionario Burnout Granada-University Students presents adequate reliability and validity indices, which demonstrates its usefulness in the identification of burnout. This syndrome has traditionally been measured in professionals, but students also present burnout, so it is necessary to have specific burnout instruments for students, since the pre-work situation and stressors of students are different from those of workers. In order to work on the prevention of university burnout, it is essential to have specific instruments for professionals in training that help in the detection of students with burnout.FEDER/Consejera de Universidad, Investigación e Inovación de la Junta de Andalucía P20-0063

    Is the Stock Exchange an advanced indicator of the real economy?

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    En este trabajo se analiza la capacidad predictiva de la bolsa sobre los principales componentes del PIB. Se atiende particularmente al posible cambio que tal capacidad predictiva pudiera experimentar como consecuencia de las implicaciones de la crisis financiera. Operativamente, se tiene en cuenta una única dirección de la causalidad posible a partir de la estimación de cuatro modelos dinámicos de retardos distribuidos de orden finito para el periodo comprendido entre 1996 y 2012. En este marco, se considera adicionalmente la posibilidad de que la relación estadística convencional entre bolsa y economía se haya visto alterada, con trastándose así la existencia de un cambio estructural. Los resultados muestran que la capacidad explicativa de los retardos de los rendimientos interanuales del IBEX-35 sobre los indicadores macroeconómicos relevantes de la economía española ha aumentado significativamente en el contexto de la actual fase cíclica contractivaThe predictive capacity of the stock market on the main components of GDP is analyzed in this paper, with special reference to possible change such predictive capability could undergo as a result of implications of the finnacial crisis. Technically, it takes into account only one possible direction of causality from the estimated four dynamic distributed lag models of finite order for the period between 1996 and 2012. This way, there is also the possibility that the conventional statistical link between the stock market and the economy has been disrupted, thus verifying the existence of a structural change. The results show that the explanatory power of the lags of the annual returns of the IBEX-35 on the relevant macro-economic indicators of Spanish economy has increased significantly in the context of the current cyclical recession phas

    Dissecting the dynamics of dysregulation of cellular processes in mouse mammary gland tumor

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    <p>Abstract</p> <p>Background</p> <p>Elucidating the sequence of molecular events underlying breast cancer formation is of enormous value for understanding this disease and for design of an effective treatment. Gene expression measurements have enabled the study of transcriptome-wide changes involved in tumorigenesis. This usually occurs through identification of differentially expressed genes or pathways.</p> <p>Results</p> <p>We propose a novel approach that is able to delineate new cancer-related cellular processes and the nature of their involvement in tumorigenesis. First, we define modules as densely interconnected and functionally enriched areas of a Protein Interaction Network. Second, 'differential expression' and 'differential co-expression' analyses are applied to the genes in these network modules, allowing for identification of processes that are up- or down-regulated, as well as processes disrupted (low co-expression) or invoked (high co-expression) in different tumor stages. Finally, we propose a strategy to identify regulatory miRNAs potentially responsible for the observed changes in module activities. We demonstrate the potential of this analysis on expression data from a mouse model of mammary gland tumor, monitored over three stages of tumorigenesis. Network modules enriched in adhesion and metabolic processes were found to be inactivated in tumor cells through the combination of dysregulation and down-regulation, whereas the activation of the integrin complex and immune system response modules is achieved through increased co-regulation and up-regulation. Additionally, we confirmed a known miRNA involved in mammary gland tumorigenesis, and present several new candidates for this function.</p> <p>Conclusions</p> <p>Understanding complex diseases requires studying them by integrative approaches that combine data sources and different analysis methods. The integration of methods and data sources proposed here yields a sensitive tool, able to pinpoint new processes with a role in cancer, dissect modulation of their activity and detect the varying assignments of genes to functional modules over the course of a disease.</p

    El col·leccionisme d’antiguitats com a mitjà de promoció social: el cas de Josep de Maranges i Marimon. Anàlisi del Compendio histórico, resumen y descripción de la antiquisima ciudad de Empurias

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    L’antiquarisme clàssic fou una eina de promoció social durant la Il·lustració. Un món associat també als estudis d’història antiga. Aquest article dóna mostra d’això a partir de Josep de Maranges i Marimon i el seu Compendio. L’obra aporta noves dades sobre la seva biografia i analitza les motivacions que el dugueren a escriure-la. La primera redacció del Compendio es relaciona amb una oferta al Príncep d’Astúries d’una col·lecció d’antiguitats reco- llida per Maranges. Això no fou una estratègia aïllada. La família Maranges anteriorment ja havia utilitzat aquest recurs per obrir-se nous cercles socials

    Identification and characterization of Rhipicephalus (Boophilus) microplus candidate protective antigens for the control of cattle tick infestations

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    The cattle ticks, Rhipicephalus (Boophilus) spp., affect cattle production in tropical and subtropical regions of the world. Tick vaccines constitute a cost-effective and environmentally friendly alternative to tick control. The recombinant Rhipicephalus microplus Bm86 antigen has been shown to protect cattle against tick infestations. However, variable efficacy of Bm86-based vaccines against geographic tick strains has encouraged the research for additional tick-protective antigens. Herein, we describe the analysis of R. microplus glutathione-S transferase, ubiquitin (UBQ), selenoprotein W, elongation factor-1 alpha, and subolesin (SUB) complementary DNAs (cDNAs) by RNA interference (RNAi) in R. microplus and Rhipicephalus annulatus. Candidate protective antigens were selected for vaccination experiments based on the effect of gene knockdown on tick mortality, feeding, and fertility. Two cDNA clones encoding for UBQ and SUB were used for cattle vaccination and infestation with R. microplus and R. annulatus. Control groups were immunized with recombinant Bm86 or adjuvant/saline. The highest vaccine efficacy for the control of tick infestations was obtained for Bm86. Although with low immunogenic response, the results with the SUB vaccine encourage further investigations on the use of recombinant subolesin alone or in combination with other antigens for the control of cattle tick infestations. The UBQ peptide showed low immunogenicity, and the results of the vaccination trial were inconclusive to assess the protective efficacy of this antigen. These experiments showed that RNAi could be used for the selection of candidate tick-protective antigens. However, vaccination trials are necessary to evaluate the effect of recombinant antigens in the control of tick infestations, a process that requires efficient recombinant protein production and formulation systems
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