Visualizing Basic Nuclear Reactions

There are few instructional tools available to teach basic nuclear reactions to beginning students. The activity described in this paper can be used to help students visualize and write basic nuclear reactions such as alpha, beta, and positron decay, as well as electron capture. These reactions are represented using the technology of thermochromic paints, which either change color or turn colorless depending upon the temperature. By using a special thermochromic paint that turns colorless upon heating, students are able to visualize nuclear interactions. For instance, when positron decay occurs, the object depicting a proton will decay into a neutron by the application of heat. In order to avoid confusion, the heating instrument is referred to as a time gun. This paper includes the details of preparing and incorporating the activity into the classroom environment

One Hour of Chemical Demonstrations

This article describes a diverse set of chemistry demonstrations especially selected to encourage student interaction and to be easily transported. The demonstrations may be presented at a level that can be tailored to any audience– from very young children to high school students planning careers in science. An ideal environment is a small classroom with 20-30 students where everyone can take part in the discussion. Once the chemicals are prepared, the collection of demonstrations takes about ten minutes to set-up, and one hour (or less) to perform. Very little is needed at the visiting site, no more than a table and a pitcher of water. A single electrical outlet is useful, but not essential. In Table 2 th

Nanotransformation of vancomycin overcomes the intrinsic resistance of Gram-negative bacteria

The increased emergence of antibiotic-resistant bacteria is a growing public health concern, and although new drugs are constantly being sought, the pace of development is slow compared with the evolution and spread of multidrug- resistant species. In this study, we developed a novel broad-spectrum antimicrobial agent by simply transforming vancomycin into nanoform using sonochemistry. Vancomycin is a glycopeptide antibiotic largely used for the treatment of infections caused by Gram-positive bacteria but inefficient against Gram-negative species. The nanospherization extended its effect toward Gram-negative Escherichia coli and Pseudomonas aeruginosa, making these bacteria up to 10 and 100 times more sensitive to the antibiotic, respectively. The spheres were able to disrupt the outer membranes of these bacteria, overcoming their intrinsic resistance toward glycopeptides. The penetration of nanospheres into a Langmuir monolayer of bacterial membrane phospholipids confirmed the interaction of the nanoantibiotic with the membrane of E. coli cells, affecting their physical integrity, as further visualized by scanning electron microscopy. Such mechanism of antibacterial action is unlikely to induce mutations in the evolutionary conserved bacterial membrane, therefore reducing the possibility of acquiring resistance. Our results indicated that the nanotransformation of vancomycin could overcome the inherent resistance of Gram-negative bacteria toward this antibiotic and disrupt mature biofilms at antibacterial-effective concentrations.Peer ReviewedPostprint (author's final draft

Motivos y hábitos de práctica de actividad física en escolares de 12 a 16 años en una población rural de Sevilla

La creciente preocupación en nuestro país por los problemas que conllevan la obesidad y el sedentarismo plantea de forma imperiosa detectar las carencias en la actividad física de la población escolar. En este sentido nuestro estudio ahonda un poco más en los motivos y hábitos de práctica de niños y niñas entre 12 y 16 años de una zona rural de Sevilla. Los resultados muestran como tan solo un 28% de las chicas practica actividad física (AF) con asiduidad. Estos porcentajes no son tan preocupantes en el caso de los chicos (58%). Otro aspecto determinante en este trabajo ha sido el establecer los motivos que llevan a los alumnos a practicar AF, siendo la diversión el motivo fundamental en chicos y chicas (38% y 31% respectivamente). Similares motivos encuentran diversos autores (García Ferrando, 1997; Palou et al., 2005; Chillón, 2005). Por otra parte ¿la falta de tiempo¿ es el principal motivo que argumentan los alumnos para no practicar AF (24% de los chicos y 28% de las chicas), siendo éste el más determinante igualmente en otros trabajos (García Ferrando, 1997; Hernán et al., 2002; Palou et al., 2005). Teniendo en cuenta los motivos y prácticas aquí reflejados, padres y educadores debemos promover estrategias atractivas que reviertan positivamente en el ocio de nuestros niños, facilitando así los tan codiciados "hábitos saludables"

Valdeande, a dos leguas de camino de "Clunia". Novedades epigráficas

Abordamos el estudio de dos inscripciones ya conocidas, de las que damos nueva lectura e interpretación, y apuntamos su posible relación con Clunia. Asimismo, editamos otras tres piezas inéditas y tres grafitos hallados todos ellos en Valdeande (Burgos).In this paper, we present a new interpretation about the study of two known Latin inscriptions from Valdeande (Burgos), developing a new meaning of them and establishing a potential link with Clunia. In addition, we show three unpublished pieces and three graffities, all of them found in Valdeande (Burgos)

Contemplative sciences: A future beyond mindfulness

Mindfulness is a psychological technique based on Eastern meditative practices that was developed in the late 1970s by Kabat-Zinn at the University of Massachusetts. Initially, there was a debate over whether it should be considered a scientific technique or labelled as part of the new wave practices. Today, mindfulness is omnipresent in modern societies but has suffered from merchandising and banalization, which has been strongly criticized. Despite some limitations regarding methodological aspects of mindfulness research, it is considered effective for treating many physical and psychological disorders, and even it is recommended in clinical guidelines such the British National Institute for Health and Care Excellence. During the last 2500 years, mindfulness practices have moved from Northern India across most of Asia, but their mixing with Western science and culture at the end of the 20(th) century is considered a key event in recent history. For the first time in human history, due to globalization, the wisdom of all contemplative traditions can be shared with all human beings and assessed by science. Mindfulness practices, yoga included, are giving birth to a new field of knowledge, contemplative sciences, which go beyond mindfulness and is devoted to helping humanity to reach higher levels of happiness and mental peace

Environmental factors influence both abundance and genetic diversity in a widespread bird species.

Genetic diversity is one of the key evolutionary variables that correlate with population size, being of critical importance for population viability and the persistence of species. Genetic diversity can also have important ecological consequences within populations, and in turn, ecological factors may drive patterns of genetic diversity. However, the relationship between the genetic diversity of a population and how this interacts with ecological processes has so far only been investigated in a few studies. Here, we investigate the link between ecological factors, local population size, and allelic diversity, using a field study of a common bird species, the house sparrow (Passer domesticus). We studied sparrows outside the breeding season in a confined small valley dominated by dispersed farms and small-scale agriculture in southern France. Population surveys at 36 locations revealed that sparrows were more abundant in locations with high food availability. We then captured and genotyped 891 house sparrows at 10 microsatellite loci from a subset of these locations (N = 12). Population genetic analyses revealed weak genetic structure, where each locality represented a distinct substructure within the study area. We found that food availability was the main factor among others tested to influence the genetic structure between locations. These results suggest that ecological factors can have strong impacts on both population size per se and intrapopulation genetic variation even at a small scale. On a more general level, our data indicate that a patchy environment and low dispersal rate can result in fine-scale patterns of genetic diversity. Given the importance of genetic diversity for population viability, combining ecological and genetic data can help to identify factors limiting population size and determine the conservation potential of populations

Connecting species’ geographical distributions to environmental variables: range maps versus observed points of occurrence

Connecting the geographical occurrence of a species with underlying environmental variables is fundamental for many analyses of life history evolution and for modeling species distributions for both basic and practical ends. However, raw distributional information comes principally in two forms: points of occurrence (specific geographical coordinates where a species has been observed), and expert-prepared range maps. Each form has potential short-comings: range maps tend to overestimate the true occurrence of a species, whereas occurrence points (because of their frequent non-random spatial distribution) tend to underestimate it. Whereas previous comparisons of the two forms have focused on how they may differ when estimating species richness, less attention has been paid to the extent to which the two forms actually differ in their representation of a species’ environmental associations. We assess such differences using the globally distributed avian order Galliformes (294 species). For each species we overlaid range maps obtained from IUCN and point-of-occurrence data obtained from GBIF on global maps of four climate variables and elevation. Over all species, the median difference in distribution centroids was 234 km, and median values of all five environmental variables were highly correlated, although there were a few species outliers for each variable. We also acquired species’ elevational distribution mid-points (mid-point between minimum and maximum elevational extent) from the literature; median elevations from point occurrences and ranges were consistently lower (median −420 m) than mid-points. We concluded that in most cases occurrence points were likely to produce better estimates of underlying environmental variables than range maps, although differences were often slight. We also concluded that elevational range mid-points were biased high, and that elevation distributions based on either points or range maps provided better estimates