3,045 research outputs found
Liner radius fluctuations in a high-gain Cherenkov free-electron laser
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
Improved determination of the 1(0)-0(0) rotational frequency of NH3D+ from the high resolution spectrum of the v4 infrared band
The high resolution spectrum of the v4 band of NH3D+ has been measured by
difference frequency IR laser spectroscopy in a multipass hollow cathode
discharge cell. From the set of molecular constants obtained from the analysis
of the spectrum, a value of 262817(6) MHz (3sigma) has been derived for the
frequency of the 1(0)-0(0) rotational transition. This value supports the
assignment to NH3D+ of lines at 262816.7 MHz recorded in radio astronomy
observations in Orion-IRc2 and the cold prestellar core B1-bS.Comment: Accepted for publication in the Astrophysical Journal Letters 04 June
201
Relation and effect of resilience on burnout in nurses: A literature review and meta-analysis
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/ConsejerÃa de Universidad, Investigación e
Innovación de la Junta de AndalucÃa, Grant/Award
Number: Project: P20_0062
Diagnosing shock temperature with NH and HO profiles
In a previous study of the L1157 B1 shocked cavity, a comparison between
NH(1-) and HO(1--1) transitions showed a
striking difference in the profiles, with HO emitting at definitely higher
velocities. This behaviour was explained as a result of the high-temperature
gas-phase chemistry occurring in the postshock gas in the B1 cavity of this
outflow. If the differences in behaviour between ammonia and water are indeed a
consequence of the high gas temperatures reached during the passage of a shock,
then one should find such differences to be ubiquitous among chemically rich
outflows. In order to determine whether the difference in profiles observed
between NH and HO is unique to L1157 or a common characteristic of
chemically rich outflows, we have performed Herschel-HIFI observations of the
NH(1-0) line at 572.5 GHz in a sample of 8 bright low-mass outflow
spots already observed in the HO(1--1) line within
the WISH KP. We detected the ammonia emission at high-velocities at most of the
outflows positions. In all cases, the water emission reaches higher velocities
than NH, proving that this behaviour is not exclusive of the L1157-B1
position. Comparisons with a gas-grain chemical and shock model confirms, for
this larger sample, that the behaviour of ammonia is determined principally by
the temperature of the gas.Comment: Accepted for publication in the Monthly Notices of the Royal
Astronomical Societ
Is the Stock Exchange an advanced indicator of the real economy?
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 estadÃstica convencional entre bolsa y economÃa se haya visto alterada, con trastándose
asà 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 economÃa española ha aumentado significativamente
en el contexto de la actual fase cÃclica 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
<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
Evaluation of Convergent, Discriminant, and Criterion Validity of the Cuestionario Burnout Granada-University Students
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 AndalucÃa
P20-0063
El col·leccionisme d’antiguitats com a mitjà de promoció social: el cas de Josep de Maranges i Marimon. Anà lisi del Compendio histórico, resumen y descripción de la antiquisima ciudad de Empurias
L’antiquarisme clà ssic 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 PrÃncep d’Astúries d’una col·lecció d’antiguitats reco-
llida per Maranges. Això no fou una estratègia aïllada. La famÃlia
Maranges anteriorment ja havia utilitzat aquest recurs per obrir-se
nous cercles socials
The 0.03-10Mo mass function of young open clusters
We report the present day mass functions (PDMFs) of 3 young open clusters
over a mass range from 30 Jupiter masses to 10~\msunn. The PDMFs of the 3
clusters are remarkably similar, suggesting little impact of specific
conditions (stellar density, metallicity, early dynamical evolution) on the
mass distribution. Functional forms are provided to allow quantitative
comparison with MFs derived in other environments.Comment: 6 pages, to appear in "IMF@50", Corbelli, Palla, Zinnecker ed
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