4,480 research outputs found
The Mg 2 h and k lines in a sample of dMe and dM stars
Both Mg II h and k line fluxes are presented for a sample of 4 dMe and 3 dM stars obtained with the IUE satellite in the long wavelength, low dispersion mode. The observed fluxes are converted to stellar surface flux units and the importance of chromospheric non radiative heating in this sample of M dwarf stars is intercompared. In addition, the net chromospheric radiative losses due to the Ca II H and K lines in those stars in the sample for which calibrated Ca II H and K line data exist are compared. Active region filling factors which likely give rise to the observed optical and ultraviolet chromospheric emission are estimated. The implications of the results for homogeneous, single component stellar model chromospheres analyses are discussed
Resistance or resignation to welfare reform? The activist politics for and against social citizenship
Since 2008, mature welfare states have, to varying degrees, pursued a strategy of welfare reform that has reconfigured the dominant praxis of social citizenship. Drawing on qualitative data from two studies, this paper explores what bearing this has had on the political subjectivity of welfare claimants in the New Zealand context. The findings suggest welfare claimants engage in diverse political struggles for and against social citizenship to resist, reconfigure and resign themselves to the prevailing socio-political settlement. In light of this, conclusions are drawn about the insurgent politics of low-income social security claimants as political agents in the citizenship-making process
Construction of the Soudan 2 detector
Progress in the construction of the Soudan 2 nucleon decay detector which is being built at the Soudan iron mine in Minnesota is discussed. The expected event rate and characteristics of low energy neutrino events, muon events, multiple muon events, and other cosmic ray phenomena are discussed
Structure of the outer layers of cool standard stars
Context: Among late-type red giants, an interesting change occurs in the
structure of the outer atmospheric layers as one moves to later spectral types
in the Hertzsprung-Russell diagram: a chromosphere is always present, but the
coronal emission diminishes and a cool massive wind steps in.
Aims: Where most studies have focussed on short-wavelength observations, this
article explores the influence of the chromosphere and the wind on
long-wavelength photometric measurements.
Methods: The observational spectral energy distributions are compared with
the theoretical predictions of the MARCS atmosphere models for a sample of 9 K-
and M-giants. The discrepancies found are explained using basic models for flux
emission originating from a chromosphere or an ionized wind.
Results: For 7 out of 9 sample stars, a clear flux excess is detected at
(sub)millimeter and/or centimeter wavelengths. The precise start of the excess
depends upon the star under consideration. The flux at wavelengths shorter than
about 1 mm is most likely dominated by an optically thick chromosphere, where
an optically thick ionized wind is the main flux contributor at longer
wavelengths.
Conclusions: Although the optical to mid-infrared spectrum of the studied K-
and M-giants is well represented by a radiative equilibrium atmospheric model,
the presence of a chromosphere and/or ionized stellar wind at higher altitudes
dominates the spectrum in the (sub)millimeter and centimeter wavelength ranges.
The presence of a flux excess also has implications on the role of these stars
as fiducial spectrophotometric calibrators in the (sub)millimeter and
centimeter wavelength range.Comment: 13 pages, 6 figures, 7 pages of online material, submitted to A&
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Deposition of inhaled charged ultrafine particles in a simple tracheal model
The deposition of ultrafine (d {le} 200 nm) particles on airway surfaces is an important determinant of the radiation dose that results from inhalation of radon progeny. The activity median diameter of particles to which radon daughters attach is small (10--140 nm). In the absence of charge, deposition in the upper airways of the respiratory system occurs by impaction for large particles and diffusion for small particles. Sedimentation is negligible due to the high flow rates in these airways. Experiments conducted in hollow casts and in vivo in humans have all shown an increase in deposition due to the particle charge. In vivo experimental results showed that there exists a threshold value of charge on the particle (q{sub c}) above which the electrostatic charge enhances deposition. These experiments were performed for particles for which deposition by diffusion is small (d {le} 300 nm). Deposition of ultrafine particles in the airways may occur by a combined mechanism of diffusion and electrostatic charge
Comparative analysis between condom use clusters and risk behaviours among portuguese university students
The research on condom use has been focused on high-risk individuals, paying less attention to those who have moderate risk or safe sexual conducts. In order to design accurate interventions, potential differences among the condom use behavior groups must be considered. The goal was to assess possible differences in individuals presenting different types of risk behavior. 140 heterosexual university students answered a self-reported questionnaire about their sexual history, condom use habits, sexual self-esteem, sexual satisfaction, sexual control, attitudes towards condoms, self-efficacy to condom use, and emotions and feelings during sexual intercourse. A cluster analysis was conducted using the results about condom use and risk behaviors. Three groups with different risk levels emerged, presenting differences over sexual self-efficacy, attitudes towards condoms, socio-demographic variables, and sexual history. The results suggest the condom use inconsistency is highly associated with other risk behaviors but the contrary does not necessarily happens. Condom use consistent users also presented risk behaviors as smoking and drinking. The group differences suggest the risks were more affected by the combination of lack of skills with a negative attitude toward condoms than by contextual or personal variables. These differences sustain the need of an intervention adjusted to the individual's risk levels, since they differ on skills and beliefs that may hinder or promote the adoption of health behaviors.Foundation for Science and Technology/Fundacao para a Ciencia e Tecnologia (Portugal)info:eu-repo/semantics/publishedVersio
Tuberculosis/HIV/AIDS coinfection in Porto Alegre, RS/Brazil - invisibility and silencing of the most affected groups
OBJECTIVE: To analyze how belonging to certain social groups contributes to constituting the vulnerabilities associated with illnesses due to tuberculosis/HIV/AIDS coinfection. METHODOLOGYThis is a qualitative study carried out in the city of Porto Alegre, state of Rio Grande do Sul, in regions of high social vulnerability. Twenty coinfected people were interviewed in specialized health services between August and December 2016. The analysis was based on the frameworks The Sound of Silence and Vulnerability and Human Rights. RESULTS: Socioeconomic conditions were decisive for the constitution of the vulnerability conditions. Processes of people invisibilization, and the silencing of their voices, in a scenario marked by economic, racial and gender inequalities, contributed for their health needs not to be understood and effectively taken into account in the services actions. FINAL CONSIDERATIONS: The more effective strategies are to legitimize voices and to understand the needs of those affected by coinfection, the greater the chances that programmatic responses to the problem will be successful
Os efeitos de uma intervenção breve em uma escola pública: uma possibilidade de dizer
Report of a form of brief intervention in a municipal school in the city of São Paulo, in an area of great vulnerability. The objective is to present the experience performed and its effects on children. Two 8-year-old children went through clinical interviews of psychoanalytic orientation, in number of three to four, in individual care. The report analyzes fragments of the sayings of those involved followed by a synthesis of what occurred in each interview. The analysis of the children's statements was highlighted, based on theoretical support of lacanian psychoanalysis and indicates that one of the children does not present learning difficulties and the other, with psychic issues, already attended a CAPS (center of psychosocial care). The results show that, from the transfer, children speak of themselves and their impasses and these can be faced in a discursive way.Informe de una forma de intervención breve en una escuela municipal de la ciudad de São Paulo, en una zona de gran vulnerabilidad. El objetivo es presentar la experiencia y sus efectos en los niños. Dos niños de 8 años se sometieron a tres o cuatro entrevistas clÃnicas psicoanalÃticas en atención individual. El informe analiza fragmentos de las declaraciones de los involucrados, seguido de un resumen de lo que sucedió en cada entrevista. Se resaltó el análisis de los dichos de los niños, basado en el apoyo teórico del psicoanálisis lacaniano e indica que uno de los niños no tiene dificultades de aprendizaje y el otro, con problemas psÃquicos, ya asistió a un CAPS (centro de atención psicosocial). Los resultados muestran que, a partir de la transferencia, los niños hablan de sà mismos y de sus impases y estos pueden enfrentarse de manera discursiva.Relato de uma forma de intervenção breve em uma escola municipal da cidade de São Paulo, em área de grande vulnerabilidade. O objetivo é apresentar a experiência realizada e seus efeitos sobre as crianças. Duas crianças de 8 anos, passaram pelas entrevistas clÃnicas de orientação psicanalÃtica, em número de três a quatro, em atendimento individual. O relato analisa fragmentos dos dizeres dos envolvidos seguidos de uma sÃntese do ocorrido em cada entrevista. A análise dos dizeres das crianças foi colocada em relevo, a partir de suporte teórico da psicanálise de vertente lacaniana e indica que uma das crianças não apresenta dificuldades de aprendizagem e a outra, com questões psÃquicas, já frequentava um CAPS (centro de atenção psicossocial). Os resultados mostram que, a partir da transferência, as crianças falam de si e de seus impasses e estes podem ser enfrentados de forma discursiva
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