The architecture and fine structure of gill filaments in the brown mussel, Perna perna

For many years, bivalve molluscs have played a useful role in determining the impact of pollution on marine organisms. In the northern hemisphere, ecologists from countries subscribing to the International Mussel Watch have used toxin-mediated changes in the organs of Mytilus edulis, especially in the morphology of gill filaments, to indicate the biotoxicity of marine effluent. M. edulis is not indigenous to South African waters. For us to adopt a similar approach on the South African east coast, it is necessary to catalogue both the normal appearance and toxin-mediated changes in our local brown mussel Perna perna. In this study, the gill filaments from five healthy, adult brown mussels were studied by light and transmission electron microscopy. Special attention was paid to filament architecture, ennervation of filaments, number and type of cells populating filament epithelia and variations in epithelial cell morphology and cilia ultrastructure. Filament shape was maintained by thickened chi-tln and strategically placed smooth myocytes. The epithelium was populated with eight morphologically distinctive non-secretory, mucus secreting or sensory cell types in various stages of differentiation. Unmyelinated nerves were situated beneath six cell types. Significant differences in filament architecture and epithelial cell morphology were found between M. edulis and P. perna. It is hoped that this comprehensive description of normal P. perna gill filaments will provide a morphological baseline for local pollution impact studies

Sistemas regionais de inovação e clusters. Instrumentos de desenvolvimento em regiões periféricas

Recientes enfoques en el estudio de las innovaciones ponen de relieve algunos aspectos del proceso de innovación en las economías: en primer lugar, el carácter sistémico e interrelacionado de la innovación y, en segundo lugar, su densidad reticular en términos de geografía y las actividades inter- económicas. Una perspectiva está relacionada con el enfoque de los sistemas de innovación de ámbito nacional, regional y local. Hoy en día las formas más especializadas de conocimiento se están convirtiendo en pequeños recursos, debido al aumento en la velocidad de los cambios que se producen en la economía global; la capacidad de aprendizaje continuo y de adaptación a este escenario de constante cambio determina el rendimiento de las empresas, de las regiones y de los países. Otra perspectiva radica en la investigación y el estudio del desarrollo de clusters, donde la proximidad y la interrelación técnica / tecnológica son los principales aspectos a tener en cuenta. Aunque estos dos enfoques funcionan a un nivel diferente en la escala espacial, ambos permiten identificar un conjunto de factores claves que contribuyen a entender la manera en que las instituciones y los actores, teniendo en cuenta el sistema de innovación o el proceso de grupo, participan de la innovación y del crecimiento económico. Sin embargo, ambos enfoques muestran la misma limitación: tienden a focalizarse en los niveles descriptivo y analítico, sin tener en cuenta el nivel explicativo. Las autoridades locales y regionales están, principalmente, interesados en procesos de intensificación de clústers en el contexto de las economías locales y regionales. Esta tendencia gana importancia cuando nos acercamos a las regiones menos favorecidas, que tienen estructuras socio-económicas débiles, y donde cada inversión tiende a suscitar un fuerte impacto positivo.Recent approaches to the study of innovations enhance some similar aspects of the innovation's process in the economies: the systemic and interrelated nature of innovation and its geographic and inter-economic activities density of networking. One perspective is related to the innovation systems' approach at the national, regional and local level. What we know so far is that the most specialized forms of knowledge are becoming short lived resources, in face of the (increasingly) fast changes that are occurring in the global economy; it's the ability to learn permanently and to adapt to this fast changing scenario that instigate the innovative performance of firms, regions and countries. One other approach is to be found in the research on clusters development, where closeness and interrelated technical/technological linkage are the main features to take under consideration. Although these two approaches operate at slightly different spatial scale of analysis, they both allow the identification of a set of key factors that contribute to understand the way in which institutions and actors, considering the innovation system or the cluster process, participate in the innovation atmosphere and in the economic growth. Nevertheless, both approaches show the same limitation: they tend to focalize into the descriptive and analytical level, disregarding the explanatory level. Local and regional authorities are, mainly, interested in the process of cluster intensification in the local and regional economies context. This propensity gains significance as we face less favoured regions, which have feeble socio-economic structures, and where every investment tends to stir up a strong positive impact.Abordagens recentes sobre o estudo de inovações salientam alguns aspectos convergentes relativos ao processo de inovação nas economias: por um lado, a natureza sistémica e interrelacional da inovação e, por outro, a sua densidade reticular em termos geográficos e ínter-actividades económicas. Uma perspectiva está relacionada com a abordagem pelos sistemas de inovação nível nacional, regional e local. Hoje em dia as formas mais especializadas de conhecimento estão-se a tornar recursos escassos, devido ao aumento da velocidade das mudanças que ocorrem na economía global; a capacidade de aprendizagem contínua e de adaptação a este cenário de constante mudança determina a performance das empresas, das regiões e dos países. Outra das perspectivas reside na pesquisa e no estudo do desenvolvimento de clusters, onde a proximidade e a interrelação técnica/tecnológica são os principais aspectos a tomar em consideraçao. Embora as duas abordagens operem a um nível diferente na escala espacial, uma e outra permitem identificar um conjunto de factores-chave que contribuem para a percepção da forma como as instituições e actores, considerando o sistema de inovação ou processo de "clusterização", participam na atmosfera inovadora e no crescimento económico. No entanto, ambas as abordagens apresentam uma limitação semelhante: tanto uma como a outra tendero a focalizar-se nos níveis descritivo e analítico à custa do nível explanatório. O poder de decisão local e regional está, principalmente, interessado em processos de intensificação de clusters, no contexto das economías locais e regionais. Esta tendência é tão ou mais importante quanto se desça a regiões mais desfavorecidas, possuidoras de estruturas socio-económicas débeis e em que qualquer investimento tende a provocar um impacto positivo

Elite male Flat jockeys display lower bone density and lower resting metabolic rate than their female counterparts: implications for athlete welfare

To test the hypothesis that daily weight-making is more problematic to health in male compared with female jockeys, we compared the bone-density and resting metabolic rate (RMR) in weight-matched male and female Flat-jockeys. RMR (kcal.kg-1 lean mass) was lower in males compared with females as well as lower bone-density Z-scores at the hip and lumbar spine. Data suggest the lifestyle of male jockeys’ compromise health more severely than females, possibly due to making-weight more frequently

Daily Parent-Adolescent Digital Exchanges

The present study tracked adolescents via mobile phones to describe how parents and their adolescent children are using digital technologies in daily life (i.e. facilitating warmth and behavioral control), and whether these uses are associated with the quality of offline parent-adolescent interactions and with adolescents’ mental health. A sample of young adolescents (N = 388; mean age 13.37) completed a 14-day ecological momentary assessment in 2016- 2017, reporting on their daily digital contact and offline interactions with their parents and their mental health. Adolescents reported using texting and calling to communicate somewhat infrequently with their parents (i.e., on 29% of days), but days with more digital contacts (for both warmth and behavioral control) were also more likely to be characterized by more positive offline interactions with parents. Furthermore, adolescents struggling with mental health symptoms across the study period reported using texts/calls more frequently to seek out parent support, and parents were more likely to do text/call “check ins” on young people who were experiencing more behavioral problems. Results highlight the potential for digital communication devices to be used as tools in fostering parent-adolescent connection, support provision, and behavioral control in the digital era

General mutation databases : analysis and review

Databases of mutations causing Mendelian disease play a crucial role in research, diagnostic and genetic health care and can play a role in life and death decisions. These databases are thus heavily used, but only gene or locus specific databases have been previously reviewed for completeness, accuracy, currency and utility. We have performed a review of the various general mutation databases that derive their data from the published literature and locus specific databases. Only two&mdash;the Human Gene Mutation Database (HGMD) and Online Mendelian Inheritance in Man (OMIM)&mdash;had useful numbers of mutations. Comparison of a number of characteristics of these databases indicated substantial inconsistencies between the two databases that included absent genes and missing mutations. This situation strengthens the case for gene specific curation of mutations and the need for an overall plan for collection, curation, storage and release of mutation data.<br /