Comparació de la cobertura de bàlec després de diferents pertorbacions amb foc, tenint en compte l'autocorrelació espacial en transectes de dos dimensions

Projecte de recerca elaborat a partir d’una estada a la University of Alberta entre juliol i octubre del 2007. Es pot comparar la cobertura d'arbustos després d'incendis i de cremes controlades en transectes amb 2 dimensions, tenint en compte l'autocorrelació espacial? Canvia el patró espacial dels arbustos després d'aquestes pertorbacions?

A critical analysis of dimensions and curve fitting practice in economics

When dealing with sustainability we are concerned with the biophysical as well as the monetary aspects of economic and ecological interactions. This multidimensional approach requires that special attention is given to dimensional issues in relation to curve fitting practice in economics. Unfortunately, many empirical and theoretical studies in economics, as well as in ecological economics, apply dimensional numbers in exponential or logarithmic functions. We show that it is an analytical error to put a dimensional unit x into exponential functions ( a x ) and logarithmic functions ( x a log ). Secondly, we investigate the conditions of data sets under which a particular logarithmic specification is superior to the usual regression specification. This analysis shows that logarithmic specification superiority in terms of least square norm is heavily dependent on the available data set. The last section deals with economists’ “curve fitting fetishism”. We propose that a distinction be made between curve fitting over past observations and the development of a theoretical or empirical law capable of maintaining its fitting power for any future observations. Finally we conclude this paper with several epistemological issues in relation to dimensions and curve fitting practice in economics

Directional discrepancy in two dimensions

In the present paper, we study the geometric discrepancy with respect to families of rotated rectangles. The well-known extremal cases are the axis-parallel rectangles (logarithmic discrepancy) and rectangles rotated in all possible directions (polynomial discrepancy). We study several intermediate situations: lacunary sequences of directions, lacunary sets of finite order, and sets with small Minkowski dimension. In each of these cases, extensions of a lemma due to Davenport allow us to construct appropriate rotations of the integer lattice which yield small discrepancy.

Reconsideration of dimensions and curve fitting practice in economics ellaborating on Georgescu-Roegen’s economic methodology

This paper is to examine the proper use of dimensions and curve fitting practices elaborating on Georgescu-Roegen’s economic methodology in relation to the three main concerns of his epistemological orientation. Section 2 introduces two critical issues in relation to dimensions and curve fitting practices in economics in view of Georgescu-Roegen’s economic methodology. Section 3 deals with the logarithmic function (ln z) and shows that z must be a dimensionless pure number, otherwise it is nonsensical. Several unfortunate examples of this analytical error are presented including macroeconomic data analysis conducted by a representative figure in this field. Section 4 deals with the standard Cobb-Douglas function. It is shown that the operational meaning cannot be obtained for capital or labor within the Cobb-Douglas function. Section 4 also deals with economists "curve fitting fetishism". Section 5 concludes thispaper with several epistemological issues in relation to dimensions and curve fitting practices in economics.

Pain: a common symptom in human immunodeficiency virus-infected Thai children.

AIM: To determine the prevalence and characteristics of pain in Thai human immunodeficiency virus-infected children. METHODS: A cross-sectional study was performed at the HIV/AIDS outpatient clinic at the Queen Sirikit National Institute of Child Health, Bangkok, Thailand from November 2002 to January 2003. Sixty-one human immunodeficiency virus-infected patients aged 4 to 15 y, an equal number of age-matched children with no chronic disease and their caregivers participated. We interviewed children and their caregivers using a structured questionnaire on pain. The main outcome measure was the percentage of human immunodeficiency virus-infected children reporting pain. RESULTS: Forty-four percent of the human immunodeficiency virus-infected children reported pain compared to 13% of the children with no chronic disease (odds ratio, OR = 5.3; 95% CI: 2.0-14.3). Seven percent of the infected children experienced chronic pain. Children in human immunodeficiency virus clinical categories B and C reported more pain than children in categories N and A (OR = 4.0, 95% CI: 1.1-14.7). Pain in infected children tended to occur in the abdomen, lower limbs or head. Only 44 percent of the infected children experiencing pain received analgesic medication. CONCLUSION: Despite being a common experience, pain is insufficiently taken into account and treated in Thai children with HIV/AIDS. Therefore, adequate pain identification, assessment and management should be systemically considered in their routine care.

Influence of altitude, latitude and season of collection (Bergmann's Rule) on the dimensions of Lutzomyia intermedia (Lutz & Neiva, 1912) (diptera, psychodidae, phlebotominae)

The influence of altitude and latitude on some structure sizes of Lutzomyia intermedia was noted; several structures of insects collected in higher localities were greater, according to Bergmann's rule. This influence was more remarkable in two localities of the State of Espírito Santo, probably due to greater differences in altitude. Comparing insects from different latitudes, more differences were noted in comparisons of insects from low altitude localities than in those of material from higher altitudes. The small number of differences between insects collected in July and in December does not indicate a defined influence of season and temperature on the size of adults. The possible epidemiological implications of these variations are discussed.

Photophobia as the presenting visual symptom of chiasmal compression.

Five patients with a chief visual complaint of photophobia were subsequently found to have compressive lesions of the optic chiasm. Visual acuity and visual field deficits were often subtle. Magnetic resonance imaging scanning revealed large suprasellar masses, including three pituitary adenomas, a craniopharyngioma, and a clivus chordoma. Photophobia resolved in all patients following treatment of the tumors. A compressive lesion of the optic chiasm should be considered in patients who experience persistent photophobia unexplained by ocular abnormalities.

Distinction of males of the Lutzomyia intermedia (Lutz & Neiva, 1912) species complex by ratios between dimensions and by an artificial neural network (Diptera: Psychodidae, Phlebotominae)

The females of the two species of the Lutzomyia intermedia complex can be easily distinguished, but the males of each species are quite similar. The ratios between the extra-genital and the genital structures of L. neivai are larger than those of L. intermedia s. s., according to ANOVA. An artificial neural network was trained with a set of 300 examples, randomly taken from a sample of 358 individuals. The input vectors consisted of several ratios between some structures of each insect. The model was tested on the remaining 58 insects, 56 of which (96.6%) were correctly identified. This ratio of success can be considered remarkable if one takes into account the difficulty of attaining comparable results using traditional statistical techniques.

La reconnaissance et le sens du travail : deux dimensions au coeur des processus de préservation de la santé mentale chez les professionnels des interventions d'urgences médicales préhospitalières

Le travail en situations d'urgence, notamment médicale, comporte de nombreux facteurs de risque pour la santé mentale. Cependant, des études récentes suggèrent que la reconnaissance de même que certains aspects relatifs au sens du travail pourraient permettre aux individus de préserver leur équilibre psychique malgré la présence de stresseurs importants.Nous avons effectué une étude portant sur la santé au travail pour des ambulanciers travaillant en Suisse romande. Dans un premier temps, une phase qualitative centrée sur l'observation du travail réel a été effectuée. Les observations ont été effectuées dans 11 services pour un total de 416 heures d'observation. Dans un second temps, un questionnaire a été développé et administré à l'ensemble des ambulanciers de Suisse romande.Notre étude a notamment permis de confirmer l'importance de la reconnaissance et du sens du travail pour les ambulanciers. [Auteurs]