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 día 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

Physicochemical quality of underground water from agricultural influence

GGroundwater in rural areas is the only source of supply for consumption and various activities. It is exposed to various pollutants that arrive through the subsoil layers. The objective of this study was to evaluate the quality of water from 15 wells in the municipality of Cotaxtla, through physicochemical variables such as pH, conductivity (EC), salinity and total dissolved solids (TDS), where the results were compared with the regulations according to its use. The samples were collected according to NOM-230-SSA1-2002. The physicochemical variables were determined with the multiparametric Consort C6010. Results ranged from pH 6.71-8.04, EC 228-4500 mS/cm, salinity 0.13-2.42 mg/L, and TDS 132-2250 mg/L. In every case, water is destined for agricultural use, where 52% is used for livestock and 80% for consumption, 60% of the wells are community and supply 612 inhabitants. According to Mexican regulations, the results obtained from EC, 13% of the wells were not suitable for consumption, in relation to the TDS results, 33% were not suitable for consumption and 13% were not suitable for agricultural irrigation. The pH showed values within the norm, however, one showed a pH of 6.71 ± 0.043, while the rest were found between 7.4 ± 0.03-8.1 ± 0.19. In all values, significant differences were shown between the sites analyze

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 $\sim$1978) and discussed in terms of the neutron star Be-disk interaction. The Be circumstellar disk was exceptionally large just before the 2009 December giant outburst, which may explain the origin of the unusual recent X-ray activity of this source. We found a peculiar evolution of the pulse profile during this giant outburst, with the two main components evolving in opposite ways with energy. A hard 30-70 mHz X-ray QPO was detected with GBM during this 2009 December giant outburst. It becomes stronger with increasing energy and disappears at energies below 25\,keV. In the long-term a strong optical/X-ray correlation was found for this system, however in the medium-term the H$_\alpha$ EW and the V-band brightness showed an anti-correlation after $\sim$2002 Agust. Each giant X-ray outburst occurred during a decline phase of the optical brightness, while the H$_\alpha$ 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$_\alpha$ line. These had a period of $\sim$\,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 $\sim$\,6 months following a giant outburst.Comment: 18, 11 figures, 1 tabl