919 resultados para recent 300 years


Relevância:

30.00% 30.00%

Publicador:

Resumo:

The Black Sea ecosystem experienced severe eutrophication-related degradation during the 1970s and 1980s. However, in recent years the Black Sea has shown some signs of recovery which are often attributed to a reduction in nutrient loading. Here, SeaWiFS chlorophyll a (chl a), a proxy for phytoplankton biomass, is used to investigate spatio-temporal patterns in Black Sea phytoplankton dynamics and to explore the potential role of climate in the Black Sea's recovery. Maps of chl a anomalies, calculated relative to the 8 year mean, emphasize spatial and temporal variability of phytoplankton biomass in the Black Sea, particularly between the riverine-influenced Northwest Shelf and the open Black Sea. Evolution of phytoplankton biomass has shown significant spatial variability of persistence of optimal bloom conditions between three major regions of the Black Sea. With the exception of 2001, chl a has generally decreased during our 8 year time-series. However, the winter of 2000–2001 was anomalously warm with low wind stress, resulting in reduced vertical mixing of the water column and retention of nutrients in the photic zone. These conditions were associated with anomalously high levels of chl a throughout much of the open Black Sea during the following spring and summer. The unusual climatic conditions occurring in 2001 may have triggered a shift in the Black Sea's chl a regime. The long-term significance of this recent shift is still uncertain but illustrates a non-linear response to climate forcing that makes future ecosystem changes in the pelagic Black Sea ecosystem difficult to predict.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Regime shifts are sudden changes in ecosystem structure that can be detected across several ecosystem components. The concept that regime shifts are common in marine ecosystems has gained popularity in recent years. Many studies have searched for the step-like changes in ecosystem state expected under a simple interpretation of this idea. However, other kinds of change, such as pervasive trends, have often been ignored. We assembled over 300 ecological time series from seven UK marine regions, covering two to three decades. We developed state-space models for the first principal component of the time series in each region, a common measure of ecosystem state. Our models allowed both trends and step changes, possibly in combination. We found trends in three of seven regions and step changes in two of seven regions. Gradual and sudden changes are therefore important trajectories to consider in marine ecosystems.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

El objetivo principal de este trabajo es, a través de las noticias publicadas en diversos medios de comunicación de la Región de Extremadura sobre bibliotecas rurales a lo largo de los últimos años, comprobar el impacto y la visibilidad de las bibliotecas en los medios. Para ello, se recopilan un total de 1196 noticias que, tras ser analizadas detalladamente, se reducen a 300 sobre las que versan los resultados del estudio. Esta disminución de noticias finales demuestra que el titular o los primeros párrafos no expresan exactamente el contenido de la noticia siendo necesario un análisis cualitativo de su contenido. Se concluye que: las noticias sobre bibliotecas rurales han decrecido en el periodo analizado (2007, 2008, 2012, 2013), siendo 2007 el año de mayor auge, si bien se ha observado un repunte en 2013 con respecto a 2012; las noticias sobre bibliotecas rurales de ámbito provincial (Badajoz y Cáceres) obtienen mayor porcentaje que las regionales y nacionales (sin representación); y el diario HOY es, con diferencia, el medio que acumula el mayor porcentaje de noticias sobre bibliotecas rurales.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Some 50 years after its creation EU competition policy remains firmly entrenched as one of the most developed examples of supranational governance within the European Union. Although there has been a marked increase in interest among political scientists in competition policy in recent years there are still gaps in terms of overall coverage. One area that has been largely overlooked centres on cartels. Cartel policy has emerged as a highly salient issue and main priority of the Commission's competition policy since the late 1990s. Certainly, the recent restructuring of the EU cartel enforcement regime, the imposition of ever higher fines and a determined EU Competition Commissioner have fuelled growing media attention while new notices and regulations increasingly occupy the interests and minds of practitioners. The European Commission has constantly extended its activities on the competition policy front and its increasingly aggressive strategies to combat cartels provides political scientists with a fascinating case study of governance in action and illustrates the ways – such as leniency programmes, higher fines, enhanced and better equipped resources as well as internal reorganisation in which the European regulator is pursuing such conspiracies. This article traces the evolution and development of EU cartel policy since its inception and assesses the Commission's strategies and considers just to what extent the European Commission is winning its war against business cartelisation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The electron beam ion trap (EBIT) in Tokyo was constructed about 10 years after the first EBIT at Lawrence Livermore National Laboratory was built, and has been being stably operated since then. In this paper, we present recent experimental activities at the Tokyo EBIT. In particular, experiments utilizing slow, very highly charged ion beams extracted from the EBIT are reported.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The Labour Government in the UK has announced, as part of its launch of The Children's Plan, that it 'wants to make this country the best place in the world for children and young people to grow up' in. This latest Plan is further evidence of the surge of interest that there has been in children (and, in particular, early childhood) over the last ten years in the UK and indeed elsewhere. Many of the recent policy and practice initiatives have implications for social workers working with young children. Yet, social work as a profession, in comparison with education, has remained relatively silent on these initiatives and it is hard to find any critical analysis of these developments in terms of either their underlying discourses or their implications for social workers. This article sets out to address these gaps by providing a critical analysis of: what types of knowledge regarding the early years have gained political currency; why and how this is the case; and what the implications are for the role and practices of social workers. The article proposes that discourses of 'need' and 'provision' mask more powerful discourses of economics, social control and risk avoidance, and it concludes by advocating more critically reflexive social work practice with young children and their families.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Initial findings from high-latitude ice-cores implied a relatively unvarying Holocene climate, in contrast to the major climate swings in the preceding late-Pleistocene. However, several climate archives from low latitudes imply a less than equable Holocene climate, as do recent studies on peat bogs in mainland north-west Europe, which indicate an abrupt climate cooling 2800 years ago, with parallels claimed in a range of climate archives elsewhere. A hypothesis that this claimed climate shift was global, and caused by reduced solar activity, has recently been disputed. Until now, no directly comparable data were available from the southern hemisphere to help resolve the dispute. Building on investigations of the vegetation history of an extensive mire in the Valle de Andorra, Tierra del Fuego, we took a further peat core from the bog to generate a high-resolution climate history through the use of determination of peat hurnification and quantitative leaf-count plant macrofossil analysis. Here, we present the new proxy-climate data from the bog in South America. The data are directly comparable with those in Europe, as they were produced using identical laboratory methods. They show that there was a major climate perturbation at the same time as in northwest European bogs. Its timinia, nature and apparent global synchronicity lend support to the notion of solar forcing of past climate change, amplified by oceanic circulation. This finding of a similar response simultaneously in both hemispheres may help validate and improve global climate models. That reduced solar activity might cause a global climatic change suggests that attention be paid also to consideration of any global climate response to increases in solar activity. This has implications for interpreting the relative contribution of climate drivers of recent 'global warming'. (c) 2006 Elsevier B.V. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Over recent years the findings of a number of quantitative research studies have been published in the UK on gender and achievement. Much of this work has emanated from Stephen Gorard and his colleagues and has not only been highly critical of existing approaches to handling quantitative data but has also suggested a number of alternative and, what they claim to be, more valid ways of measuring differential patterns of achievement and underachievement between groups. This article shows how much of this work has been based upon rather under-developed measures of achievement and underachievement that tend, in turn, to generate a number of misleading findings that have questionable implications for practice. It will be argued that this body of work provides a useful case study in the problems of quantitative research that fails to engage adequately with the substantive theoretical and empirical literature and considers some of the implications of this for future research in this area.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The enteroinsular axis (EIA) constitutes a physiological signalling system whereby intestinal endocrine cells secrete incretin hormones following feeding that potentiate insulin secretion and contribute to the regulation of blood glucose homeostasis. The two key hormones responsible are named glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Recent years have witnessed sustained development of antidiabetic therapies that exploit the EIA. Current clinical compounds divide neatly into two classes. One concerns analogues or mimetics of GLP-1, such as exenatide (Byetta) or liraglutide (NN2211). The other group comprises the gliptins (e. g. sitagliptin and vildagliptin) which boost endogenous incretin activity by inhibiting the enzyme dipeptidyl peptidase 4 (DPP 4) that degrades both GLP-1 and GIP. Ongoing research indicates that further incretin and gliptin compounds will become available for clinical use in the near future, offering comparable or improved efficacy. For incretin analogues there is the prospect of prolonged duration of action and alternative routes of administration. This review focuses on recent advances in pre-clinical research and their translation into clinical studies to provide future therapies for type 2 diabetes targeting the EIA.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Context: Transient hypothyroxinemia is the commonest thyroid dysfunction of premature infants, and recent studies have found adverse associations with neurodevelopment. The validity of these associations is unclear because the studies adjusted for a differing range of factors likely to influence neurodevelopment. Objective: The aim was to describe the association of transient hypothyroxinemia with neurodevelopment at 5.5 yr corrected age. Design: We conducted a follow-up study of a cohort of infants born in Scotland from 1999 to 2001 =34 wk gestation. Main Outcome Measures: We measured scores on the McCarthy scale adjusted for 26 influences of neurodevelopment including parental intellect, home environment, breast or formula fed, growth retardation, and use of postnatal drugs. Results: A total of 442 infants =34 wk gestation who had serum T4 measurements on postnatal d 7, 14, or 28 and 100 term infants who had serum T4 measured in cord blood were followed up at 5.5 yr. Infants with hypothyroxinemia (T4 level = 10th percentile on d 7, 14, or 28 corrected for gestational age) scored significantly lower than euthyroid infants (T4 level greater than the 10th percentile and less than the 90th percentile on all days) on all McCarthy scales, except the quantitative. After adjustment for confounders of neurodevelopment, hypothyroxinemic infants scored significantly lower than euthyroid infants on the general cognitive and verbal scales. Conclusions: Our findings do not support the view that the hypothyroxinemic state, in the context of this analysis, is harmless in preterm infants. Many factors contribute both to the etiology of hypothyroxinemia and neurodevelopment; strategies for correction of hypothyroxinemia should acknowledge its complex etiology and not rely solely on one approach.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Recent patterns of migration indicate that international migrants are not confined to urban gateways. Instead many migrants have settled in new destination areas located in rural and small town areas. While this might appear to be a positive phenomenon for rural areas struggling with decline and stagnation, the reality is that many of these areas are ill-equipped to manage the rate and pace of change that has been witnessed in recent years. Migration to established, typically urban areas has been the subject of extensive research. However, little is known about the way in which migrants navigate their way through social structures as they settle into destinations with little experience of immigration. Using empirical research, this article considers the way in which migrants navigate their way through social structures to establish life in a so-called ‘new’ migration destination. It analyses the way in which government and civil society respond to their needs of recent arrivals, showing how both NGO’s and the statutory sector play an important role in this process. It considers the ramifications for these different sectors and the implications for so-called ‘new’ destinations as they become more established or ‘mature’ areas of immigration.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

There is a growing body of knowledge that uses innovative qualitative methods to support and facilitate the involvement of young children, aged 7 years and under, in the research process. Across several fields of study the recent growth in research that engages with young children stands in sharp contrast with the situation just a few years ago where there was a dearth of activity and knowledge in this area. Designed to seek their views, experiences and perspectives the range of methods is now burgeoning. This chapter explores reasons for the growth in the use of innovative qualitative methods, the underlying principles through which the engagement of young children has been achieved and the different types of method with detailed case examples. For each method the main critical issues regarding their effectiveness are identified and discussed in further detail. The latter sections of the chapter focus on contemporary issues regarding the use of innovative methods. Highlighted, in particular, are some of the common concerns and criticisms with regards to the trustworthiness, reliability, validity and generalizability of the data that is collated using innovative qualitative methods.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Subduction modifies the cycling of Earth's volatile elements. Fluid-rich sediments and hydrated oceanic lithosphere enter the convecting mantle at subduction zones. Some of the sediments and volatile components are released from the subducting slab, promote mantle melting and are returned to the surface by volcanism. The remainder continue into the deeper mantle. Quantification of the fate of these volatiles requires an understanding of both the nature and timing of fluid release and mantle melting(1). Here we analyse the trace element and isotopic geochemistry of fragments of upper mantle rocks that were transported to the surface by volcanic eruptions above the Batan Island subduction zone, Philippines. We find that the mantle fragments exhibit extreme disequilibrium between their U-Th-Ra isotopic ratios, which we interpret to result from the interaction of wet sediment melts and slab-derived fluids with rocks in the overlying mantle wedge. We infer that wet sediments were delivered from the slab to the mantle wedge between 8,000 and 10,000 years ago, whereas aqueous fluids were delivered separately much later. We estimate that about 625 ppm of water is retained in the wedge. A significant volume of water could therefore be delivered to the mantle transition zone at the base of the upper mantle, or even to the deeper mantle.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In recent years UK university-based nurse educators have seen a reduction in their responsibilities for nursing students’ practice-based assessments. Many university-based nurse educators feel that this lack of input into students’ clinical assessments leaves them open to criticism as they are perceived to be less “in-touch” with clinical practice and that their knowledge to teach nursing students is diminished as a result. This paper examines and debates some interpretations of the term “recent clinical practice” and challenges the misconception among many in the profession, as well as government and professional bodies, that university-based nurse educators require recent clinical practice to effectively teach students and enhance the student learning experience in the academic university setting.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

INTRODUCTION: Irish dental graduates are eligible to enter general dental practice immediately after qualification. Unlike their United Kingdom counterparts, there is no requirement to undertake vocational training (VT) or any pre-registration training. VT is a mandatory 12-month period for all UK dental graduates who wish to work within the National Health Service. It provides structured, supervised experience in training practices and through organised study days.

AIMS: This study aimed to profile the career choices made by recent dental graduates from UCC. It aimed to record the uptake of VT and associate posts, and where the graduates gained employment.

METHODOLOGY: A self-completion questionnaire was developed and circulated electronically to recent graduates from UCC. An existing database of email addresses was used and responses were returned by post or by email. A copy of the questionnaire used is included as Appendix 1.

RESULTS: Questionnaires were distributed over an eight-week period and 142 were returned, giving a response rate of 68.90%. Responses were gathered from those who graduated between 2001 and 2007; however, the majority came from more recent classes. Overall, the majority of graduates took up associate positions after qualification (71.8%) with smaller numbers undertaking VT (28.2%). Increasing numbers have entered VT in recent years, including 54.3% from the class of 2007. Overall, the majority of graduates initially took up positions in England (43%); however, in recent times more have been employed in Scotland. Subsequent work profiles of the graduates illustrate that the majority are now working as associates in general practice (51.4%) and in Ireland (54.2%).

CONCLUSIONS: There has been an increase in the proportion of UCC graduates undertaking VT. Graduates tended to move away from Ireland initially to gain employment. There has been a shift away from employment in England towards Scotland where the majority of new UCC graduates are now initially employed. The majority of graduates returned to Ireland for employment after the initial move away.