Apropar les classes de biologia als debats més actuals : a tall de mostra, els parcs naturals. 'Acercar las clases de biología a los debates más actuales : como muestra, los parques naturales'.

La enseñanza de las ciencias se puede realizar mediante diversas aproximaciones pero el enorme contenido conceptual y cierta actitud de inercia hacen que esta enseñanza a menudo se aleje de la realidad. En los últimos años se ha avanzado especialmente en la significacion de los contenidos para el alumnado y en el tratamiento de las cuestiones más candentes y controvertidas de la sociedad actual. Una buena muestra es el estudio del concepto de parque natural para poder usar algunos recursos educativos. Se aborda el caso de los espacios naturales protegidos en las islas Baleares, su evolución histórica y las tendencias actuales. Finalmente se incluyen algunas propuestas pedagógicas y se aconsejan algunas páginas web.

A tall de reflexió sobre la ciència a l'aula : benvingudes siguin experiències així. 'A modo de reflexión sobre la ciencia en el aula : bienvenidas sean experiencias así'.

Resumen basado en el de las autoras

Characterisation of an amphioxus Fringe gene and the evolution of the vertebrate segmentation clock

In mouse and chick embryos, cyclic expression of lunatic fringe has an important role in the regulation of mesoderm segmentation. We have isolated a Fringe gene from the protochordate amphioxus. Amphioxus is the closest living relative of the vertebrates, and has mesoderm that is definitively segmented in a manner that is similar to, and probably homologous with, that of vertebrates. AmphiFringe is placed basal to vertebrate Fringe genes in molecular phylogenetic analyses, indicating that the duplications that formed radical-, manic- and lunatic fringe are specific to the vertebrate lineage. AmphiFringe expression was detected in the anterior neural plate of early neurulae, where it resolved into a series of segmental patches by the mid-neurulae stage. No AmphiFringe transcripts were detected in the mesoderm. Based on these observations, we propose a model depicting a successive recruitment of Fringe in the maintenance then regulation of segmentation during vertebrate evolution.

Shifting sand, shifting livelihoods? Reflections on a coastal gold rush in Ghana

Artisanal and small-scale mining (ASM) is often characterised as rush-type activity undertaken by people looking to ‘get-rich quick’. An alternative view posits ASM as poverty-driven activity which provides a valuable source of employment to a rural population where agriculture has failed to provide an adequate income. Against this dichotomy, this article critically reviews the short-lived, but high profile, gold rush which occurred on the beaches of Elmina, a fishing town in Ghana’s Central Region. At its peak, more than 1000 people, including local fishermen and career miners from the Western Region and Eastern Region of the country, were mining on the beaches. Drawing on interviews with miners and local business owners, the analysis explores the dynamics of the rush and its implications for understanding the ASM sector in Ghana. The discussion highlights the challenges associated with managing resources in dynamic and heterogeneous contexts, reconciling separate and conflicting sectoral priorities and the need to go beyond simplified and dualistic representations of the sector.

Produktion, skador och grenegenskaper hos 10-årig tall i ett kombinerat förbands- och avkommeförsök : Volume production, damages and branch properties in a 10-year old combined spacing and progeny trial of Scots pine

A Scots pine (Pinus sylvestris) progeny trial was established in 1990, in the southwestern part of Sweden. The offspring was from 30 plus trees. The trial is located on abandoned agricultural land and has a single tree block design with a variation in spacing. The trial has been damaged by voles. At a tree age of ten years, growth, damages and branch properties were estimated. An analysis of variance on height, diameter and stem volume shows significant difference between spacing and progenies as well as interactions between these factors. As indicated by a better annual height increment and fewer and thinner branches at each whorl the densest spacing has the highest potential to produce quality logs.There were also differences between progenies in growth and quality traits. Some progenies combined good growth and branch characters with low mortality, straight stems and few damages. Other progenies had superior volume production.

The “Lunatic Fringe” -- Barry Goldwater and the Conservative Revolution of the 1960s --

How did conservatives, who had become effectively ostracized by their party following the Great Depression and the societal reforms of the New Deal, regain leverage within the GOP during the 1960s? My hypothesis is two-fold. First, I contend that a small group of conservative activists led by F. Clifton White, in spite of a dearth of resources and manpower, managed to infiltrate Republican infrastructure and “hijack” the delegate- selection process. The distinctly conservative and recalcitrant disposition of the Goldwater delegates demonstrates that these activists succeeded. Second, I argue that in addition to temporarily overpowering the national convention in 1964, conservatives thereafter retained control of the party insofar as subsequent GOP candidates were obliged to garner the support of conservative pockets of the country in order to win the presidential nomination. The resulting rightward shift of the Republican Party following the 1960s is a direct corollary of the conservative takeover outlined in this study.

Living on the Fringe

Just when you thought the news could not get any worse for libraries, a new twist emerges on an old theme. When I saw the headline, I couldn't help clicking: “Books Are Becoming the Fringe Media.”

Growth and yield analysis in different methods of beet (Cv. 'tall top early wonder') plantation

This objective of this study was to evaluate the effects of different methods of red beet seedling production and direct sowing on the development of the plant in field conditions. 'Tall Top Early Wonder' was used as the cultivar. The experimental design was a randomized blocks with 4 replications of each treatment: T1 - seedling produced in trays of 288 cells; T2 - 200 cells; T3 - 128 cells; T4 - 128 cells; T5 - direct sowing and T6 - bare-root seedling. The seedlings produced in trays and bare root seedlings were transplanted in the field 28 DAS with spacing of 0.20 x 0.10m. The mean height of plants, leaf area, leaf dry matter, petiole dry matter, shoot dry matter, root dry matter, relationship between shoot dry matter and root dry matter, absolute growth rate, relative growth rate, net assimilation rate, leaf area ratio and specific leaf area were determined. Storage root fresh matter and mean storage root diameter were determined starting from 77 DAS. Initial growth of the plants were superior for the direct sowing, resulting in smaller RGR and NAR than the other treatments. Independent of the production method, an increase of the cycle of the crop was verified. T6 had larger delay in the initial development. There was no difference for productivity. Method T1, had less expenses with respect to substrate and space in the vegetation home, without reduction in production.

Use of sneaker rush and symptoms occurrence of skeletal muscle (SME) in Ballerina

Introduction: Technical literature shows high frequencies of injuries occurring in classical ballet dancers; however, only limited information about the permanent effects of chronic diseases are mentioned. Objective: To compare the presence of MSD among dancers who wear pointe shoes and those who do not. Methods: The research was conducted at the 27th Festival of Joinville in Santa Catarina. The study had the participation of 111 dancers, 88 of whom wore pointe shoes while 23 did not. Specific procedures were used to obtain information related to MSD and foot injuries caused by dancing. Results: The most affected parts were the knees (29.7% with pointe shoes versus 39% without), spine (26.4% with pointe shoes versus 22% without), and ankle/foot (20% with pointe shoes versus 12.2% without). Through odds ratio and respective confidence intervals (IC95%), the study identified protection factor in the knees (0.24; CI95% - 0.09-0.64) and legs (0.11; CI95% - 0.02-0.65) for dancers who wear pointe shoes. It was found that the risk of injuries in specific structures of the foot is significantly higher among those dancers. In this case, the appearance of bunions (9.74; CI95% - 1.25-75,99), calluses on the toes (3.46; CI95% - 1.29-9.27) and the association of the three (4.47; CI95% - 1.69-11.83) were those that showed an increased risk factor compared to dancers who do not stand en pointe. Conclusion: The use of pointe shoes in elite Brazilian dancers was associated to lower occurrence of MSD in the knee and leg, however it was strongly associated to foot injuries.

Tall oil e seus subprodutos: alternativas como preservantes para madeira

Pós-graduação em Engenharia Mecânica - FEG