Reproduction of algebraic structures by 16-18 year old students

In this exploratory research we analyze the structure sense evidenced by 33 secondary students (16-18 years old) in tasks requiring to reproduce the structure of given algebraic expressions. The expressions used were algebraic fractions related to algebraic identities. There were big differences between the students performance which allowed differencing levels in students´ structure sense. Questions and conjectures to be addressed in future research are presented

Efecto de fitofortificantes comerciais sobre o crecemento de cultivos de Alfalfa

[Resumen] En este trabajo se ha evaluado el efecto del producto comercial Manvert Sulphos®, sobre el cultivo de plántulas de alfalfa (Medicago sativa). Manvert Sulphos®, es un producto rico en azufre que se comercializaba para favorecer el crecimiento vegetativo de las plantas y para fortalecerlas contra diversas condiciones adversas como son el estrés abiótico y el ataque de hongos. Su uso como fitofortificante podría solventar posibles carencias de azufre en los suelos ocasionadas por las bajas concentraciones de materia orgánica y el uso de otros compuestos que no llevan incorporado este elemento químico en su composición. Después de su aplicación, para determinar su eficacia estudiamos diferentes parámetros: las variaciones en peso fresco, peso seco y cenizas, cambios en las concentraciones de clorofila y carotenoides, funcionamiento de los sistemas fotosintéticos así como las posibles variaciones en el contenido proteico y de azufre elemental en plantas. Para ello sembramos las semillas de alfalfa y las dejamos crecer en una cámara bajo unas condiciones controladas. Cuando la planta ya se ha desarrollado lo suficiente, le aplicamos el Manvert Sulphos® e hicimos una serie de ensayos para medir los parámetros anteriores empleando como referencia unas plantas control que eran tratadas con agua. Finalmente, tras comprobar si las diferencias eran significativas estadísticamente pudimos ver como la aplicación del Manvert Sulphos®, provocó en la alfalfa un aumento de peso fresco, seco y humedad, un aumento de los niveles de N y un mayor contenido de clorofila y carotenoides.[Abstract] This work evaluated the effect of the commercial product Manvert Sulphos®, on the growing of alfalfa seedlings (Medicago sativa). Manvert Sulphos®, is a sulfur‐rich product that was commercialized for enhancing vegetative growth and plant resistence against different adverse conditions such as stress and fungal attacks. Its use as phytostrengthener could solve potential shortcomings of this element in soils due to low concentrations of organic matter and the use of other compounds which do not containing sulfur After application, its efficacy was determined by different parameters: changes in fresh weight, dry weight and ashes, changes in the concentration of chlorophylls and carotenoids, operation of photosynthetic systems and possible variations in protein content and elemental sulfur in plants. The alfalfa seeds were sown and grown into a chamber under controlled conditions. When the plant was already developed enough, we applied the Manvert Sulphos® and made a series of tests to measure the above parameters by using a Control plants treated with water. Finally, after checking whether the differences were statistically significant, we could see how the application of Manvert Sulphos®, resulted in an increase of plant fresh weight, dry, humidity, increased levels of N and a higher content in chlorophylls and carotenoids.Traballo fin de grao (UDC.CIE). Bioloxí

La presencia de helicobacter pylori en sujetos obesos y su relación con el I.M.C.

El Helicobacter pylori afecta al 50 % de la población mundial. Esta bacteria ha sido identificada como el agente causal de la úlcera péptica y como carcinógeno tipo I, también se ha incluido en los factores clave para el desarrollo de la obesidad. La obesidad es el resultado del desequilibrio entre el gasto y el aporte de energía, que supone un exceso de grasa en el cuerpo y se encuentra asociada frecuentemente con comorbilidades. El hecho de que las hormonas gástricas que regulan la ingesta de alimentos (grelina y leptina) puedan ser modificadas tras la erradicación del Helicobacter pylori y el bypass gástrico, refuerza la importancia de estudiar cómo influye este hecho en el desarrollo de la obesidadOtroGrado en Enfermerí

A new factorial decomposition for the atkinson measure

In this article we explore an alternative factorial decomposition for Atkinson indices and taking Sala-i-Martin's (2002) article “The Disturbing ''Rise'' of Global Income Inequality†as a reference, the possibilities of Atkinson indices are shown in regard to completing and detailing information in studies of inequality among populations and populations subgroups.Atkinson Inequality Measure

Local weather, food resources and breeding stage influence Thrush Nightingale movement

Insectivorous migrants breeding at northern latitudes often time the breeding period with the seasonal peak of food resources. Whether this general pattern transfers to movement behaviour during the breeding season requires detailed study from a local perspective. We investigated fine-scale environmental correlates of movements by six actively-breeding adult Thrush Nightingales (Luscinia luscinia) at a breeding site in Denmark, using radio tracking and multiple regression models. Overall, the chick-rearing period coincided with the peak of vegetation greenness at the site. Adults flew further from nesting areas during stable weather and as vegetation greenness decreased. Adults were more active at higher environmental temperatures and when fledglings were older but still dependent on adults. These changes in local movements likely reflect adjustments to chick developmental needs and to specific local environmental conditions, including resource availability

Unit-Consistent Aggregative Multidimensional Inequality Measures: A Characterization

Inequality among people involves comparisons of social indicators such as income, health, education and so on. In recent years the number of studies both theoretical and empirical which take into account not only the individual’s income but also these other attributes has significantly increased. As a consequence the development of measures capable of capturing multidimensional inequality and satisfying reasonable axioms becomes a useful and important exercise.The aim of this paper is no other than this. More precisely, we consider the unit consistency axiom proposed by B. Zheng in the unidimensional framework. This axiom demands that the inequality rankings, rather than the inequality cardinal values as the traditional scale invariance principle requires, are not altered when income is measured in different monetary units. We propose a natural generalization of this axiom in the multidimensional setting and characterize the class of aggregative multidimensional inequality measures which are unit-consistent.multidimensional inequality indices, unit-consistency, aggregativity.

Promoter trapping in microalgae using the antibiotic paromomycin as selective agent

The lack of highly active endogenous promoters to drive the expression of transgenes is one of the main drawbacks to achieving efficient transformation of many microalgal species. Using the model chlorophyte Chlamydomonas reinhardtii and the paromomycin resistance APHVIII gene from Streptomyces rimosus as a marker, we have demonstrated that random insertion of the promoterless marker gene and subsequent isolation of the most robust transformants allows for the identification of novel strong promoter sequences in microalgae. Digestion of the genomic DNA with an enzyme that has a unique restriction site inside the marker gene and a high number of target sites in the genome of the microalga, followed by inverse PCR, allows for easy determination of the genomic region, which precedes the APHVIII marker gene. In most of the transformants analyzed, the marker gene is inserted in intragenic regions and its expression relies on its adequate insertion in frame with native genes. As an example, one of the new promoters identified was used to direct the expression of the APHVIII marker gene in C. reinhardtii, showing high transformation efficiencies.Junta de Andalucía (P09-CVI-5053)Junta de Andalucía (BIO-214

The Extended Atkinson Family and Changes in the Expenditure Distribution: Spain 1973/74-2003

This paper emphasizes the properties of a family of inequality measures which extends the Atkinson indices and is axiomatically characterized by a multiplicative decomposition property where the withingroup component is a generalized weighted mean with weights summing exactly to 1. This family contains canonical forms of all aggregative inequality measures, each bounded above by 1, has a useful and intuitive geometric interpretation and provides an alternative dominance criterion for ordering distributions in terms of inequality. Taking the Spanish Household Budget Surveys (HBS) for 1973/74, 1980/81, and 1990/91 and the more recent Continuous HBS for 2003, we show the advantages and possibilities of this extended family in regard to completing and detailing information in studies of inequality focussing on the tails of the distribution and on the changes in the distribution when the population is partitioned into population subgroups.inequality measurement, Atkinson indices