16,052 research outputs found
Multichromatic colour-magnitude diagrams of the globular cluster NGC 6366
We present multichromatic isochrone fits to the colour-magnitude data of the
globular cluster NGC 6366, based on Hubble Space Telescope Advanced Camera for
Surveys/Wide Field Channel and Southern Astrophysical Research photometric
data. We corrected the photometric data for differential reddening and
calculated the mean ridge line of the colour-magnitude diagrams. We compared
the isochrones of Dartmouth Stellar Evolution Database and PAdova and TRieste
Stellar Evolution Code both with microscopic diffusion starting on the main
sequence. Bracketing all previous determinations of this cluster, we tested
metallicities from [Fe/H]=-1.00 to [Fe/H]=-0.50, and ages from 9 to 13 Gyr.
After determining the total to selective extinction ratio only from stars
belonging to this cluster, R_V=3.06+/-0.14, we found the parameters for this
cluster to be E(B-V)=0.69+/-0.02(int)+/-0.04(ext),
(m-M)_V=15.02+/-0.07(int)+/-0.13(ext), Age=11+/-1.15 Gyr. Evolutionary models
fail to reproduce the low-Teff sequence in multiband colour-magnitude diagrams,
indicating that they still have an incomplete physics. We found that the
Dartmouth Stellar Evolution Database isochrones better fit the subgiant branch
and low main sequence than the PAdova and TRieste Stellar Evolution Code.Comment: 9 pages, 5 figure
Personality styles and defense mechanisms in a community sample of adolescents: An exploratory study
This study aimed to test if the preference for using certain types of defense mechanisms, according to Ihilevich and Gleser’s (1969,
1986) perspective, is associated with personality styles, proposed
by Millon (1993), and also, aimed to test if both constructs give a
contribution to the identification of global types of psychological
functioning in adolescents. Eight hundred and thirty adolescents,
ranging in age from 14 to 19 years (M = 16.64, SD = 1.9) participated
in the study. The Portuguese versions of the Defense Mechanisms
Inventory for Adolescents and the Millon Adolescents
Clinical Inventory were administered. Multiple linear regression
analysis and principal component analysis were computed.
Results demonstrate an association between defense mechanisms
and personality styles and both constructs contribute to the identification
of two types of psychological functioning in adolescents:
an internalizing type and an externalizing type
Testing Models Relating Rejection, Depression, Interpersonal Needs, and Psychache to Suicide Risk in Nonclinical Individuals
Objectives: Using structural equation modeling, we tested a primary model of suicide risk and
3 competing, alternative models based on 4 psychological variables deemed important in the literature
(perception of parental rejection, depression, interpersonal needs comprising perceived burdensomeness
and thwarted belongingness, and psychache), in a nonclinical sample of Portuguese adults.
Method: A convenience sample of 203 adults (100men, 103women; aged18–65 years) participated
in this study. Results: Analyses demonstrated that the proposed primary model had the best fit
to the observed data. The differences in fit indexes for this model and one of the alternative models,
however, were not substantial. Conclusion: Perceived parental rejection related directly to suicide
risk and indirectly via depression and interpersonal needs. Depression linked indirectly to suicide risk
via interpersonal needs and psychache. Interpersonal needs related directly to suicide risk and indirectly
via psychache, which related directly to suicide risk
Suicide risk in a Portuguese non-clinical sample of adults
Background and Objectives: This exploratory study simultaneously tests
the contribution of socio-demographic, clinical, distress, and personality variables for identifying suicide risk in a non-clinical sample. Methods: A convenience sample of 810 adults ranging in age from 19 to 67 years (M = 36.34, SD = 12.46) and living in various Portuguese regions participated. Their education varied from 6 to 21 years of schooling (M = 11.74, SD = 5.14). Participants responded to sociodemographic
questions, the Depressive Experiences Questionnaire, the Center for the Epidemiological
Studies of Depression Scale, and the Suicide Behaviors Questionnaire-Revised.
Results: In the present sample, 4.3% of participants indicated past suicide attempts,
27.9% reported some lifetime suicide ideation, and 6.4% indicated a past suicide plan. Depressive
symptoms, having seen a psychologist or psychiatrist, self-criticism, and education
discriminated between participants who had attempted suicide (n = 35) and those who
had not attempted to die by suicide (n = 775). Depressive symptoms, having seen a psychologist or psychiatrist, self-criticism, psychiatric disease and age discriminated between
participants who scored below (n = 650) and who scored equal to or above (n = 160) the cut-off score for the Suicide Behaviors Questionnaire-Revised.
Conclusions: Results have implications for the assessment of suicide risk
Factors associated with postharvest ripening heterogeneity of "Hass" avocados (Persea americana Mill)
Indexación: Web of ScienceIntroduction. 'Hass' is the main avocado cultivar commercialized worldwide. The extended flowering period, very low percentage of fruit set and inability to ripen on the tree renders the fruit heterogeneous and unpredictable during postharvest management. The "triggered" and "ready-to-eat" growing markets for 'Hass' avocados are affected by the variable postharvest ripening or ripening heterogeneity which creates severe logistical problems for marketers and inconsistent quality delivery to consumers. Synthesis. The dry matter content, the current avocado harvest index that correlates very well with oil content, has been extensively used to harvest 'Hass' avocados to comply with the minimum standards to guarantee consumer satisfaction. However, previous work and empirical experience demonstrate that dry matter does not correlate on a fruit-to-fruit basis with time to reach edible ripeness. Thus, avocados of very different ages are harvested from individual trees, resulting in heterogeneous postharvest ripening of fruit within a specific batch. Several preharvest factors related to environmental and growing conditions and crop management as well as postharvest technology strategies influence the observed variability of postharvest ripening. Conclusion. Modern approaches based on studying the composition of individual fruits displaying contrasting postharvest ripening behavior, combined with non-destructive phenotyping techniques, seem to offer practical solutions for the fresh supply chain of avocados to sort fruit based on their ripening capacity.http://www.pubhort.org/fruits/2016/5/fruits160045.ht
Effect of flocculation and sedimentation times on the removal of polystyrene microplastics from water
A novel high-throughput analytical method to quantify microplastics in water by flow cytometry
Microplastics (MPs) are pervasive contaminants with unclear toxicological impacts. Current research on MP pollution relies on low-throughput methodologies, which are time-consuming and cannot directly measure MP concentration in suspensions. This study presents a qualitative and quantitative flow cytometry-based method for analysing MPs in water, offering a faster and more sustainable alternative. The method involves density separation to remove interfering particles, UV irradiation to eliminate microorganisms, and filtration to remove particles above 100 µm. The sensitivity of the method for different types of MPs, such as polystyrene (PS), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polyamide (PA) microbeads, ranges from 2 µg/L to 1 mg/L. For these MPs, good linearity was found in matrix-matched calibration where the most concentrated standard was 5 mg/L (R2 0.9820–0.9989) although the linear range can be larger (e.g. 42 mg MP/L for PS microbeads). The repeatability and reproducibility of the method for the model PS MP were <17.0% and 8.5%, respectively. The sample treatment method consisting of density separation and UV pretreatment, when carried out independently, led to 95.0% and 93.4% recoveries. The overall trueness of the optimized method for various sizes and compositions of microbeads is about 97%, according to validation supported by microscopy analysis. This method can substitute the traditional quantitative analytical approach based on counting microbeads with microscopy
MetodologÃa para seleccionar tecnologÃas Web 2.0 para la docencia
Actualmente existe un gran auge en el uso y
difusión de las herramientas Web 2.0 tanto en
el contexto profesional como en el personal.
Su aplicación al ámbito de la docencia, tal y
como sugieren algunos estudios, puede tener
numerosas ventajas. Sin embargo, el abanico
de herramientas Web 2.0 es muy amplio y
por tanto serÃa de utilidad disponer de una
metodologÃa que pudiera guiar al docente a
la hora de elegir la tecnologÃa más adecuada
a su proceso de enseñanza-aprendizaje según
los objetivos perseguidos, asà como en su
implantación y posterior evaluación de los
resultados alcanzados.
En este artÃculo, se presenta una
metodologÃa de ayuda a los docentes de
cualquier área de conocimiento para la
selección e implantación de la tecnologÃa Web
2.0 que más se adapte a un determinado
proceso de enseñanza-aprendizaje en base a
criterios docentes y técnicos. Esta metodologÃa
es el resultado de un proyecto de mejora e
innovación educativa en el cual se han
llevado a cabo diversas experiencias docentes
sobre la aplicación de herramientas Web
2.0 en asignaturas de distintas titulaciones
universitarias.SUMMARY -- The use and dissemination of Web 2.0
tools in professional and personal context
is becoming more popular every day. Its
application to teaching, as it is suggested by
some studies, may have numerous advantages.
However, the range of Web 2.0 tools is very
broad and it would therefore be useful to
have a methodology that guide the teacher
in choosing the most appropriate technology
to their teaching-learning process, taking into
account some final objectives, as well as
implementing and evaluating the achieved
results.
This paper presents a methodology to
assist teachers from any area of knowledge
in the selection of the Web 2.0 technology
that best suits a particular teaching-learning
process. This selection is based on some
educational and technical criteria. The
presented methodology is the result of an
educational innovation and improvement
project in which various teaching experiences
based on the use of Web 2.0 tools have been
carried out in different subjects of science
degrees.Peer Reviewe
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