1,106 research outputs found
Effects of a thermal inversion experiment on STEM students learning and application of damped harmonic motion
There are diverse teaching methodologies to promote both collaborative and
individual work in undergraduate physics courses. However, few educational
studies seek to understand how students learn and apply new knowledge through
open-ended activities that require mathematical modeling and experimentation
focused on environmental problems. In this work, we propose a novel home
experiment to simulate the dynamics of a particulate under temperature
inversion and model it as damped harmonic motion. Twenty six first year
students enrolled in STEM majors answered six qualitative questions after
designing and developing the experiment. These questions helped analyze the
students epistemological beliefs about their learning process of physics topics
and its applications. Results showed that this type of open-ended experiments
could facilitate the students understanding of physics phenomena. In addition,
this experiment showed that it could help physics professors to promote
students epistemological development by giving their students the opportunity
to search for different sources of knowledge and becoming self-learners instead
of looking at the professor as the epistemological authority. At the end,
students described this activity as a positive experience that helped them
realize alternative ways to apply physics topics in different contexts of their
environment.Comment: 23 pages, 5 figure
Human immunodeficiency virus and other sexually transmitted diseases in Cuban women
ABSTRACTA cross-sectional study was performed in 60 Cuban women of child-bearing age who were sero-positive for human immunodeficiency virus (HIV) and 60 controls. Human papillomavirus (HPV) was identified most frequently, with oncogenic HPV serotypes 16, 33 and 58 detected in HIV-positive patients, and serotypes 11, 33 and 51 in the controls (relative risk 4.41; 95% CI 2.21– 8.29). Syphilis and hepatitis B and C viruses were detected exclusively in HIV-sero-positive women (p < 0.05). Sexually transmitted diseases (STDs) appeared to pose a substantial health problem, especially for HIV-positive women. Clinics should consider screening and treatment for STDs as part of their HIV prevention programmes
Temas clave en la formación de profesores en Chile desde la perspectiva de docentes y directivos
Teacher education in Chile and the issues that intersect it are nowadays in the public debate of the Chilean society. This study aims at analyze key issues on teacher education- research, innovation, continuous education, university-school relationship, and management- from the perspective of academics, school-teachers and administrators. The study was conducted on 222 participants from Chilean universities and schools in the context of a non-experimental research design of cross-sectional and descriptive nature. The surveys and semi-structured interviews results show that it is necessary to strengthen the relationship between schools and universities, train teachers that achieve effective performances in the current socio-educational contexts and create the conditions for teachers to do research of their own pedagogical practices.La formación de profesores en Chile y los puntos que la intersectan, están hoy en dÃa en el debate público de la sociedad chilena. El objetivo de este estudio es analizar temas clave de la formación de profesores- investigación, innovación, formación continua, relación universidad-establecimiento educacional, y gestión- desde la perspectiva de profesores universitarios, profesores del sistema escolar y directivos. Para esto, el estudio se realizó con una muestra de 222 participantes de establecimientos educacionales y universidades chilenas en el contexto de un diseño investigativo de carácter no experimental y de tipo transeccional descriptivo. Los resultados de las encuestas y entrevistas aplicadas revelan que es necesario fortalecer la relación establecimiento educacional y universidad, formar profesores que tengan un desempeño efectivo en los contextos socio-educativos actuales y crear las condiciones para que los profesores puedan realizar investigaciones de sus propias prácticas pedagógicas
Artefacts and <A2> power corrections : revisiting the MOM Z_psi and Z_V
We extract the power corrections due to the A^2 condensate in the overlap
quark propagator (vector part of the inverse propagator Z_psi). The results are
consistent with the previous gluon analysis. The role of artefacts is
extensively discussed.Comment: 33 pages, 5 figure
Preserved Error-Monitoring in Borderline Personality Disorder Patients with and without Non-Suicidal Self-Injury Behaviors
Background: The presence of non-suicidal self-injury acts in Borderline Personality Disorder (BPD) is very prevalent. These behaviors are a public health concern and have become a poorly understood phenomenon in the community. It has been proposed that the commission of non-suicidal self-injury might be related to a failure in the brain network regulating executive functions. Previous studies have shown that BPD patients present an impairment in their capacity to monitor actions and conflicts associated with the performance of certain actions, which suppose an important aspect of cognitive control. Method: We used Event Related Potentials to examine the behavioral and electrophysiological indexes associated with the error monitoring in two BPD outpatients groups (17 patients each) differentiated according to the presence or absence of non-suicidal self-injury behaviors. We also examined 17 age- and intelligence- matched healthy control participants. Results: The three groups did not show significant differences in event-related potentials associated with errors (Error-Related Negativity and Pe) nor in theta power increase following errors. Conclusions: This is the first study investigating the behavioral and electrophysiological error monitoring indexes in BPD patients characterized by their history of non-suicidal self-injury behaviors. Our results show that error monitoring is preserved in BPD patients and suggest that non-suicidal self-injury acts are not related to a dysfunction in the cognitive control mechanisms
Key issues on Chilean teacher education from the perspective of teachers and administrators
Teacher education in Chile and the issues that intersect it are nowadays in the public debate of the Chilean society. This study aims at analyze key issues on teacher education- research, innovation, continuous education, university-school relationship, and management- from the perspective of academics, school-teachers and administrators. The study was conducted on 222 participants from Chilean universities and schools in the context of a non-experimental research design of cross-sectional and descriptive nature. The surveys and semi-structured interviews results show that it is necessary to strengthen the relationship between schools and universities, train teachers that achieve effective performances in the current socio-educational contexts and create the conditions for teachers to do research of their own pedagogical practices.</p
The Châtelperronian Neanderthals of Cova Foradada (Calafell, Spain) used imperial eagle phalanges for symbolic purposes
Evidence for the symbolic behavior of Neanderthals in the use of personal ornaments is relatively scarce. Among the few ornaments documented, eagle talons, which were presumably used as pendants, are the most frequently recorded. This phenomenon appears concentrated in a specific area of southern Europe during a span of 80 thousand years. Here, we present the analysis of one eagle pedal phalange recovered from the Châtelperronian layer of Foradada Cave (Spain). Our research broadens the known geographical and temporal range of this symbolic behavior, providing the first documentation of its use among the Iberian populations, as well as of its oldest use in the peninsula. The recurrent appearance of large raptor talons throughout the Middle Paleolithic time frame, including their presence among the last Neanderthal populations, raises the question of the survival of some cultural elements of the Middle Paleolithic into the transitional Middle to Upper Paleolithic assemblages and beyond
X-Ray and Optical Observations of A 0535+26
We present recent contemporaneous X-ray and optical observations of the
Be/X-ray binary system A\,0535+26 with the \textit{Fermi}/Gamma-ray Burst
Monitor (GBM) and several ground-based observatories. These new observations
are put into the context of the rich historical data (since 1978) and
discussed in terms of the neutron star Be-disk interaction. The Be
circumstellar disk was exceptionally large just before the 2009 December giant
outburst, which may explain the origin of the unusual recent X-ray activity of
this source. We found a peculiar evolution of the pulse profile during this
giant outburst, with the two main components evolving in opposite ways with
energy. A hard 30-70 mHz X-ray QPO was detected with GBM during this 2009
December giant outburst. It becomes stronger with increasing energy and
disappears at energies below 25\,keV. In the long-term a strong optical/X-ray
correlation was found for this system, however in the medium-term the
H EW and the V-band brightness showed an anti-correlation after
2002 Agust. Each giant X-ray outburst occurred during a decline phase of
the optical brightness, while the H showed a strong emission. In late
2010 and before the 2011 February outburst, rapid V/R variations are observed
in the strength of the two peaks of the H line. These had a period of
\,25 days and we suggest the presence of a global one-armed oscillation
to explain this scenario. A general pattern might be inferred, where the disk
becomes weaker and shows V/R variability beginning \,6 months following a
giant outburst.Comment: 18, 11 figures, 1 tabl
On the leading OPE corrections to the ghost-gluon vertex and the Taylor theorem
This brief note is devoted to a study of genuine non-perturbative corrections
to the Landau gauge ghost-gluon vertex in terms of the non-vanishing
dimension-two gluon condensate. We pay special attention to the kinematical
limit which the bare vertex takes for its tree-level expression at any
perturbative order, according to the well-known Taylor theorem. Based on our
OPE analysis, we also present a simple model for the vertex, in acceptable
agreement with lattice data.Comment: Final version published in JHE
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