894 resultados para El Nino Current - Environmental aspects


Relevância:

40.00% 40.00%

Publicador:

Resumo:

Information is summarized on juvenile salmonid distribution, size, condition, growth, stock origin, and species and environmental associations from June and August 2000 GLOBEC cruises with particular emphasis on differences related to the regions north and south of Cape Blanco off Southern Oregon. Juvenile salmon were more abundant during the August cruise as compared to the June cruise and were mainly distributed northward from Cape Blanco. There were distinct differences in distribution patterns between salmon species: chinook salmon were found close inshore in cooler water all along the coast and coho salmon were rarely found south of Cape Blanco. Distance offshore and temperature were the dominant explanatory variables related to coho and chinook salmon distribution. The nekton assemblages differed significantly between cruises. The June cruise was dominated by juvenile rockfishes, rex sole, and sablefish, which were almost completely absent in August. The forage fish community during June comprised Pacific herring and whitebait smelt north of Cape Blanco and surf smelt south of Cape Blanco. The fish community in August was dominated by Pacific sardines and highly migratory pelagic species. Estimated growth rates of juvenile coho salmon were higher in the GLOBEC study area than in areas farther north. An unusually high percentage of coho salmon in the study area were precocious males. Significant differences in growth and condition of juvenile coho salmon indicated different oceanographic environments north and south of Cape Blanco. The condition index was higher in juvenile coho salmon to the north but no significant differences were found for yearling chinook salmon. Genetic mixed stock analysis indicated that during June, most of the Chinook salmon in our sample originated from rivers along the central coast of Oregon. In August, chinook salmon sampled south of Cape Blanco were largely from southern Oregon and northern California; whereas most chinook salmon north of Cape Blanco were from the Central Valley in California.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Plastics packaging is ubiquitous in the food industry, fulfilling a range of functions including a significant role in reducing food waste. The public perception of packaging, however, is dominated by end-of-life aspects, when the packaging becomes waste often found littering urban, rural and marine environments. A balanced analysis of the role of packaging demands that the whole lifecycle is examined, looking not only at the packaging itself but also at the product being packaged. This paper focuses on packaging in the meat and cheese industry, analysing the impact of films and bags. The functions of packaging are defined and the environmental impact of delivering these functions is assessed. The influence of packaging on levels of waste and energy consumption elsewhere in the system is examined, including the contentious issue of end-of-life for packaging. Strategies for minimizing the environmental impact of the packaging itself involve reduction in the amount of material used (thinner packaging), rather than emphasizing end-of-life issues. Currently, with polymer recycling not at a high level, evidence suggests that this strategy is justifiable. Biodegradable polymers may have some potential for improving environmental performance, but are still problematic. The conclusion is that although current packaging is in some ways wasteful and inefficient, the alternatives are even less desirable. © 2013 Elsevier B.V. All rights reserved.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The Healthy and Biologically Diverse Seas Evidence Group (HBDSEG) has been tasked with providing the technical advice for the implementation of the Marine Strategy Framework Directive (MSFD) with respect to descriptors linked to biodiversity. A workshop was held in London to address one of the Research and Development (R&D) proposals entitled: ‘Mapping the extent and distribution of habitats using acoustic and remote techniques, relevant to indicators for area/extent/habitat loss.’ The aim of the workshop was to identify, define and assess the feasibility of potential indicators of benthic habitat distribution and extent, and identify the R&D work which could be required to fully develop these indicators. The main points that came out of the workshop were: (i) There are many technical aspects of marine habitat mapping that still need to be resolved if cost-effective spatial indicators are to be developed. Many of the technical aspects that need addressing surround issues of consistency, confidence and repeatability. These areas should be tackled by the JNCC Habitat Mapping and Classification Working Group and the HBDSEG Seabed Mapping Working Group. (ii) There is a need for benthic ecologists (through the HBDSEG Benthic Habitats Subgroup and the JNCC Marine Indicators Group) to finalise the list of habitats for which extent and/or distribution indicators should be considered for development, building upon the recommendations from this report. When reviewing the list of indicators, benthic habitats could also be distinguished into those habitats that are defined/determined primarily by physical parameters (although including biological assemblages) (e.g. subtidal shallow sand) and those defined primarily by their biological assemblage (e.g. seagrass beds). This distinction is important as some anthropogenic pressures may influence the biological component of the ecosystem despite not having a quantifiable effect on the physical habitat distribution/extent. (iii) The scale and variety of UK benthic habitats makes any attempt to undertake comprehensive direct mapping exercises prohibitively expensive (especially where there is a need for repeat surveys for assessment). There is a clear need therefore to develop a risk-based approach that uses indirect indicators (e.g. modelling), such as habitats at risk from pressures caused by current human activities, to develop priorities for information gathering. The next steps that came out of the workshop were: (i) A combined approach should be developed by the JNCC Marine Indicators Group together with the HBDSEG Benthic Habitats Subgroup, which will compile and ultimately synthesise all the criteria used by the three different groups from the workshop. The agreed combined approach will be used to undertake a final review of the habitats considered during the workshop, and to evaluate any remaining habitats in order to produce a list of habitats for indicator development for which extent and/or distribution indicators could be appropriate. (ii) The points of advice raised at this workshop, alongside the combined approach aforementioned, and the final list of habitats for extent and/or distribution indicator development will be used to develop a prioritised list of actions to inform the next round of R&D proposals for benthic habitat indicator development in 2014. This will be done through technical discussions within JNCC and the relevant HBDSEG Subgroups. The preparation of recommendations by these groups should take into account existing work programmes, and consider the limited resources available to undertake any further R&D work.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Tras las observaciones efectuadas durante la sesión de la Amical Internacional de Fitosociogía en la Jura franco-suiza, los autores exponen alganos datos complementarios sobre las comunidades megafórbicas jurasianas con Cicerbita alpina y Adenostyles alliaria y analizan desde un nuevo punto de vista, la comunidad arbustiva de Jun¡perus nana, Pinus uncinata, Sorbus chamaespilus, Laburnum alpinum.., que existen en los pisos subalpino y montano superior del Jura.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

A pesar de la progresiva introducción de nuevos recursos en las aulas fruto del desarrollo de las TICs, el libro de texto sigue siendo uno de los materiales más utilizado y cuyo protagonismo en la configuración de la práctica escolar ha sido decisivo, por lo que debe ocupar nuestra atención en la formación inicial de los profesionales de la educación. Durante los cursos académicos 2012-13 y 13-14, hemos realizado en el marco de la asignatura de Análisis y diseño de materiales para la educación y la formación del tercer curso del grado de Pedagogía de la Universidad de Oviedo una práctica formativa de análisis de libros de texto escolares que nos ha permitido analizar contextualizadamente y desde una perspectiva teórico-práctica, cuestiones tales como: papel del profesorado en el desarrollo e innovación del currículum, papel de las editoriales en la interpretación del currículum oficial, análisis de tareas y mensajes en los manuales escolares, criterios para juzgar la calidad didáctica de los materiales, etc. El análisis cualitativo de treinta informes desarrollados por 120 estudiantes sobre diferentes libros de texto nos ha permitido identificar sus principales fortalezas y debilidades en varias dimensiones (aspectos formales, metodología, mensajes, implicaciones para la profesionalidad docente) y nos permite concluir que se trata de una experiencia formativa relevante en la formación inicial de cualquier profesional de la educación.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

El paso del tiempo tiene una repercusión inevitable sobre las obras de arte. En el caso del arte contemporáneo muchos de los valores estéticos, culturales o sociales presentes en las mismas, están vinculados a la apariencia y al uso premeditado de la materia. La transformación de la materia tiene una repercusión sobre la intención y el discurso estético, por ello, y ante la imposibilidad de impedir el cambio, se hace necesaria una profunda reflexión sobre el concepto de autenticidad de la obra de arte y sobre el concepto de ruina prematura. Por otro lado, gracias a la figura del artista contemporáneo es posible documentar la producción actual para determinar si la mutación de la materia afectará a lo esencial en las obras. En este sentido, el trabajo ha conseguido concretar, para el caso de varios artistas fundamentales del panorama español, qué aspectos deben, por ser esenciales, permanecer inmutables con el paso del tiempo.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The objectives of the text are to take stock of the international experience with SEA; to highlight the key aspects and areas of the process development and application and to probe issues related to the quality and the effectiveness of SEA practice. These are successfully weaved together as each theme is unpacked and the individual authors apply their own interpretations and experiences to current thinking.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Eubacteria of the genus Rhodococcus are a diverse group of microorganisms commonly found in many environmental niches from soils to seawaters and as plant and animal pathogens. They exhibit a remarkable ability to degrade many organic compounds and their economic importance is becoming increasingly apparent. Although their genetic organisation is still far from understood, there have been many advances in recent years. Reviewed here is the current knowledge of rhodococci relating to gene transfer, recombination, plasmid replication and functions, cloning vectors and reporter genes, gene expression and its control, bacteriophages, insertion sequences and genomic rearrangements. Further fundamental studies of Rhodococcus genetics and the application of genetic techniques to the these bacteria will be needed for their continued biotechnological exploitation.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The International Olympic Committee (IOC) declares environmental protection to be the third dimension of the Olympic movement. That, in effect, means that nations wishing to host the Games have to present themselves as reliable practitioners of environmental sustainability (ES) in their applications. The greening of sports mega-events, and the hosting of Olympic Games in particular, is now reasonably well established. Yet evidence from the first decade of environmentally-conscious Olympics points to diverging patterns of achievement in the operationalisation of the IOC’s ‘third pillar’. As is now common knowledge, for example, Sydney 2000 was the first ‘Green Olympics’ in the history of the Games; yet four years later, Athens provided a stark contrast, and was the subject of highly critical assessment reports by environmental organisations. Yet Athens has not stopped the Bid Committee for the Beijing 2008 Games claiming that it would ‘leave the greatest Olympic Games environmental legacy ever’ (UNEP 2007: 26), while the London 2012 promotes the concept of the ‘One Planet Olympics’.

In this context and in light of the current global economic crisis, can we claim that London 2012 has the capacity to fulfil its environmental ambitions? This question is adopted in continuity with similar framed questions that have been posed in relation to the most recent Olympics and it is tackled by adopting an investigative model that is placed within discourses of ‘reflexive modernisation’.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

We investigate the so-called nonresonant cosmic-ray streaming instability, first discussed by Bell (2004). The extent to which thermal damping and ion-neutral collisions reduce the growth of this instability is calculated. Limits on the growth of the nonresonant mode in SN1006 and RX J1713.7-3946 are presented.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The application of electric bias across tip–surface junctions in scanning probe microscopy can readily induce surface and bulk electrochemical processes that can be further detected though changes in surface topography, Faradaic or conductive currents, or electromechanical strain responses. However, the basic factors controlling tip-induced electrochemical processes, including the relationship between applied tip bias and the thermodynamics of local processes, remains largely unexplored. Using the model Li-ion reduction reaction on the surface in Li-ion conducting glass ceramic, we explore the factors controlling Li-metal formation and find surprisingly strong effects of atmosphere and back electrode composition on the process. We find that reaction processes are highly dependent on the nature of the counter electrode and environmental conditions. Using a nondepleting Li counter electrode, Li particles could grow significantly larger and faster than a depleting counter electrode. Significant Li ion depletion leads to the inability for further Li reduction. Time studies suggest that Li diffusion replenishes the vacant sites after 12 h. These studies suggest the feasibility of SPM-based quantitative electrochemical studies under proper environmental controls, extending the concepts of ultramicroelectrodes to the single-digit nanometer scale.