Present Day (present + day)

Distribution by Scientific Domains
Distribution within Humanities and Social Sciences


Selected Abstracts


THE 1930s AND THE PRESENT DAY , CRISES COMPARED

ECONOMIC AFFAIRS, Issue 4 2009
Panagiotis Evangelopoulos
Many analysts are comparing the deep crisis of our times with the crash of 1929 and the Great Depression that followed in the 1930s. They generally argue that Barack Obama is driving the world to recovery along Roosevelt's ,state superiority' line. Alas, today's crisis rings alarm bells for the manner in which we must manage the future of democracy, the state and markets. Markets cannot be ,ordered about' and when in the face of sound logic and practice an attempt is made to do just this, markets become refractory, or , even worse , they may collapse. [source]


Introduction to Global Military History: 1775 to the Present Day By Jeremy Black

HISTORY, Issue 305 2007
GERARD DOUDS
No abstract is available for this article. [source]


Changing household responses to drought in Tharaka, Kenya: vulnerability, persistence and challenge

DISASTERS, Issue 2 2008
Thomas A. Smucker
Drought is a recurring challenge to the livelihoods of those living in Tharaka District, Kenya, situated in the semi-arid zone to the east of Mount Kenya, from the lowest slopes of the mountain to the banks of the Tana River. This part of Kenya has been marginal to the economic and political life of Kenya from the colonial period until the present day. A study of more than 30 years of change in how people in Tharaka cope with drought reveals resilience in the face of major macro-level transformations, which include privatisation of landownership, population growth, political decentralisation, increased conflict over natural resources, different market conditions, and environmental shifts. However, the study also shows troubling signs of increased use of drought responses that are incompatible with long-term agrarian livelihoods. Government policy needs to address the challenge of drought under these new macro conditions if sustainable human development is to be achieved. [source]


Taxonomic diversity gradients through geological time

DIVERSITY AND DISTRIBUTIONS, Issue 4 2001
J. Alistair Crame
Abstract., There is evidence from the fossil record to suggest that latitudinal gradients in taxonomic diversity may be time-invariant features, although almost certainly not on the same scale as that seen at the present day. It is now apparent that both latitudinal and longitudinal gradients increased dramatically in strength through the Cenozoic era (i.e. the last 65 my) to become more pronounced today than at any time in the geological past. Present-day taxonomic diversity gradients, in both the marine and terrestrial realms, are underpinned by the tropical radiations of a comparatively small number of species-rich clades. Quite why these particular taxa proliferated through the Cenozoic is uncertain, but it could be that at least part of the explanation involves the phenomenon of evolutionary escalation. This is, in essence, a theory of biological diversification through evolutionary feedback mechanisms between predators and prey; first one develops an adaptive advantage, and then the other. However, there may also have been some form of extrinsic control on the process of tropical diversification, and this was most likely centred on the phenomenon of global climate change. This is especially so over the last 15 my Various Late Cenozoic (Neogene) vicariant events effectively partitioned the tropics into a series of high diversity centres, or foci. It has been suggested that, in the largest of these in the marine realm (the Indo-West Pacific or IWP centre), a critical patterns of islands acted as a template for rapid speciation during glacioeustatic sea level cycles. The same process occurred in the Atlantic, Caribbean and East Pacific (ACEP) centre, though on a lesser scale. Tropical terrestrial diversity may also have been promoted by rapid range expansions and contractions in concert with glacial cycles (a modified refugium hypothesis). We are beginning to appreciate that an integrated sequence of Neogene tectonic and climatic events greatly influenced the formation of contemporary taxonomic diversity patterns. [source]


The trouble with drink: why ideas matter

ADDICTION, Issue 5 2010
Griffith Edwards
ABSTRACT This paper builds upon the work of previous authors who have explored the evolution of ideas in the alcohol arena. With revisions in the relevant sections of ICD and DSM forthcoming, such matters are of considerable contemporary importance. The focus here will be upon the history of the last 200 years. The main themes to be explored include the flux of ideas on what, over time, has counted as the trouble with drink, ideas on the cause of the problem and the impact of this thinking on public action. Medical authorities of the late Enlightenment period made the revolutionary suggestion that habitual drunkenness constituted a disease, rather than a vice. The thread of that idea can be traced to the present day, but with an alternative perception of drink itself or alcohol-related problems generally, as cause for concern, also having a lineage. There are several inferences to be drawn from this history: the need for vigilance lest disease formulations become stalking-horses for moralism and social control, the need to integrate awareness of alcohol dependence as a dimensional individual-level problem, with a public health understanding of the vastly amorphous and at least equally important universe of alcohol-related problems; the dangers lurking in scientific reductionism when the problems at issue truly require a multi-disciplinary analysis; and the need for global consensus rather than cultural imposition of ideas on what counts as the problem with drink. [source]


GOVERNMENT INTERVENTION IN CHILD REARING: GOVERNING INFANCY

EDUCATIONAL THEORY, Issue 3 2010
Robert A. Davis
In this essay, Robert Davis argues that much of the moral anxiety currently surrounding children in Europe and North America emerges at ages and stages curiously familiar from traditional Western constructions of childhood. The symbolism of infancy has proven enduringly effective over the last two centuries in associating the earliest years of children's lives with a peculiar prestige and aura. Infancy is then vouchsafed within this symbolism as a state in which all of society's hopes and ideals for the young might somehow be enthusiastically invested, regardless of the complications that can be anticipated in the later, more ambivalent years of childhood and adolescence. According to Davis, the understanding of the concept of infancy associated with the rise of popular education can trace its pedigree to a genuine shift in sensibility that occurred in the middle of the eighteenth century. After exploring the essentially Romantic positions of Johann Heinrich Pestalozzi and Friedrich Fröbel and their relevance to the pattern of reform of early childhood education in the United Kingdom and the United States, Davis also assesses the influence of figures such as Stanley Hall and John Dewey in determining the rationale for modern early childhood education. A central contention of Davis's essay is that the assumptions evident in the theory and practice of Pestalozzi and his followers crystallize a series of tensions in the understanding of infancy and infant education that have haunted early childhood education from the origins of popular schooling in the late eighteenth century down to the policy dilemmas of the present day. [source]


The historic man-made soils of the Generalife garden (La Alhambra, Granada, Spain)

EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2007
R. Delgado
Summary We studied the soils of the Patio de la Acequia garden of the Generalife, a palatial villa forming part of La Alhambra, a World Heritage Site in Granada, Spain. This garden, which is estimated to be around 700 years old, is the oldest historical garden in the Western World. The soils are man-made cumulimollihumic-calcaric (hypereutric, anthric) Regosols. Noteworthy amongst the main pedogenic processes, in relation to the human activities of cultivation, irrigation and tillage, are horizonation, melanization (the contents of organic carbon varied between 0.59% and 8.87%, and those of P205 extracted with citric acid between 723 mg kg,1 and 7333 mg kg,1, with maximae in the Ap horizons) and structure formation. The soil fabric, studied at the ultramicroscopic level using scanning electron microscopy, is of laminar and partition-walls' type in the lower horizons, depending on the microped zones. The partition-walls' fabrics found are different to those of the possible pre-existing sedimentary fabrics. These are numerous lithological discontinuities and at least two burials, leading us to deduce that there have been two main stages of filling with materials in the formation of these soils. The first is Arabic-Medieval (13th century), when the garden was created, its surface being some 50 cm below the level of the paved area of the present patio. In the deeper parts, the materials employed in the fill are similar to the in situ soils of the zone, unaffected by the buildings. The second stage is Christian (15th century to the present day). During this period the Medieval garden was gradually buried under a layer of materials from the nearby soils and/or sediments mixed with manure until the surface was only just below the level of the paved area of the patio. In this work we discuss the difficult classification of these relatively little studied soils. In spite of their being clearly related to human activity, they are not classified as Anthrosols in the FAO system (1998) because soil materials cannot be classified as anthropopedogenic or as anthropogeomorphic. [source]


HOW BRIGHT AND HOW NASTY: EXPLAINING DIVERSITY IN WARNING SIGNAL STRENGTH

EVOLUTION, Issue 3 2007
Michael P. Speed
The conspicuous displays that warn predators of defenses carried by potential prey have been of interest to evolutionary biologists from the time of Wallace and Darwin to the present day. Although most studies implicitly assume that these "aposematic" warning signals simply indicate the presence of some repellent defense such as a toxin, it has been speculated that the intensity of the signal might reliably indicate the strength of defense so that, for example, the nastiest prey might "shout loudest" about their unprofitability. Recent phylogenetic and empirical studies of Dendrobatid frogs provide contradictory views, in one instance showing a positive correlation between toxin levels and conspicuousness, in another showing a breakdown of this relationship. In this paper we present an optimization model, which can potentially account for these divergent results. Our model locates the optimal values of defensive traits that are influenced by a range of costs and benefits. We show that optimal aposematic conspicuousness can be positively correlated with optimal prey toxicity, especially where population sizes and season lengths vary between species. In other cases, optimal aposematic conspicuousness may be negatively correlated with toxicity; this is especially the case when the marginal costs of aposematic displays vary between members of different populations. Finally, when displays incur no allocation costs there may be no single optimum value for aposematic conspicuousness, rather a large array of alternative forms of a display may have equal fitness. [source]


Lessons from the past: the collapse of Jamaican coral reefs

FISH AND FISHERIES, Issue 2 2009
Marah J. Hardt
Abstract Since Pre-Columbian times, humans have exploited Jamaican marine ecosystems with significant consequences for flora and fauna. This study focuses on the history of reef fish exploitation in Jamaica, from first human occupation to the present day, to determine how past fishing activities contributed to subsequent declines in the coral reef ecosystem. The pattern of declining reef fish populations was nonlinear. Reef fish first declined in prehistoric times but then potentially recovered, following genocide of the native human population. Reduced fishing pressure lasted until the mid-19th century. At that time, depletion of reef fish populations again occurred with a precipitous decline from the 1850s to the 1940s. The final shift from relatively abundant to overfished marine fauna corresponded to subtle changes in fish trap design as well as development of recreational fishing. Government subsidies throughout the second half of the 20th century exacerbated the declines. This analysis shows that local artisanal fisheries with relatively low levels of effort and seemingly subtle shifts in technology can significantly impact the coral reef ecosystem and that declines occurred decades to centuries before modern ecological studies began. This research shows how historical analysis can be a powerful tool to minimize shifted baselines and establish realistic targets for recovery and sustainable management of marine ecosystems. [source]


Comparison of the maritime Sites and Monuments Record with side-scan sonar and diver surveys: A case study from Rathlin Island, Ireland

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 5 2002
Rory Quinn
Rathlin Island, off the north coast of Ireland, has a history of settlement and seafaring from the Late Mesolithic period to the present day. The maritime Sites and Monuments Record (SMR) for Rathlin indicates many wrecking incidents. In 1999, a reconnaissance side-scan sonar survey confirmed the presence of 46 targets of possible archaeological potential around Rathlin Island. Thirteen of these anomalies were positively identified as shipwrecks. Of the remaining 33 targets, nine were dived on in order to ground-truth the geophysical data. A successful and rapid methodology of ground-truthing side-scan sonar data for archaeological purposes was developed. The results confirmed the presence of a Danforth Anchor at one site, while the remaining anomalies were identified as geological features. The results from the side-scan survey and diver-truthing exercise enhanced the existing maritime SMR. © 2002 Wiley Periodicals, Inc. [source]


Overpressure and petroleum generation and accumulation in the Dongying Depression of the Bohaiwan Basin, China

GEOFLUIDS (ELECTRONIC), Issue 4 2001
X. Xie
Abstract The occurrence of abnormally high formation pressures in the Dongying Depression of the Bohaiwan Basin, a prolific oil-producing province in China, is controlled by rapid sedimentation and the distribution of centres of active petroleum generation. Abnormally high pressures, demonstrated by drill stem test (DST) and well log data, occur in the third and fourth members (Es3 and Es4) of the Eocene Shahejie Formation. Pressure gradients in these members commonly fall in the range 0.012,0.016 MPa m,1, although gradients as high as 0.018 MPa m,1 have been encountered. The zone of strongest overpressuring coincides with the areas in the central basin where the principal lacustrine source rocks, which comprise types I and II kerogen and have a high organic carbon content (>2%, ranging to 7.3%), are actively generating petroleum at the present day. The magnitude of overpressuring is related not only to the burial depth of the source rocks, but to the types of kerogen they contain. In the central basin, the pressure gradient within submember Es32, which contains predominantly type II kerogen, falls in the range 0.013,0.014 MPa m,1. Larger gradients of 0.014,0.016 MPa m,1 occur in submember Es33 and member Es4, which contain mixed type I and II kerogen. Numerical modelling indicates that, although overpressures are influenced by hydrocarbon generation, the primary control on overpressure in the basin comes from the effects of sediment compaction disequilibrium. A large number of oil pools have been discovered in the domes and faulted anticlines of the normally pressured strata overlying the overpressured sediments; the results of this study suggest that isolated sandstone reservoirs within the overpressured zone itself offer significant hydrocarbon potential. [source]


Reconstruction of the Ross Ice Drainage System, Antarctica, at the Last Glacial Maximum

GEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 2-3 2000
George H. Denton
We present here a revised reconstruction of the Ross ice drainage system of Antarctica at the last glacial maximum (LGM) based on a recent convergence of terrestrial and marine data. The Ross drainage system includes all ice flowlines that enter the marine Ross Embayment. Today, it encompasses one-fourth of the ice-sheet surface, extending far inland into both East and West Antarctica. Grounding lines now situated in the inner Ross Embayment advanced seaward at the LGM (radiocarbon chronology in Denton and Marchant 2000 and in Hall and Denton 2000a, b), resulting in a thick grounded ice sheet across the Ross continental shelf. In response to this grounding in the Ross (and Weddell) Embayment, ice-surface elevations of the marine-based West Antarctic Ice Sheet were somewhat higher at the LGM than at present (Steig and White 1997; Borns et al. 1998; Ackert et al. 1999). At the same time, surface elevations of the East Antarctic Ice Sheet inland of the Transantarctic Mountains were slightly lower than now, except near outlet glaciers that were dammed by grounded ice in the Ross Embayment. The probable reason for this contrasting behavior is that lowered global sea level at the LGM, from growth of Northern Hemisphere ice sheets, caused widespread grounding of the marine portion of the Antarctic Ice Sheet, whereas decreased LGM accumulation led to slight surface lowering of the interior terrestrial ice sheet in East Antarctica. Rising sea level after the LGM tripped grounding-line recession in the Ross Embayment, which has probably continued to the present day (Conway et al. 1999). Hence, gravitational collapse of the grounded ice sheet from the Ross Embayment, accompanied by lowering of the interior West Antarctic ice surface and of outlet glaciers in the Transantarctic Mountains, occurred largely during the Holocene. At the same time, increased Holocene accumulation caused a slight rise of the inland East Antarctic ice surface. [source]


Regional Devolution and Regional Economic Success: Myths and Illusions about Power

GEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 2 2006
Ray Hudson
Abstract The proposition that regional devolution in and of itself will lead to economic success has become deeply embedded in beliefs and policy discourses about the determinants of regional prosperity, and in turn has led to political demands for such devolution. In this paper I seek critically to examine such claims, using the case of the north-east of England as the setting for this examination. The paper begins with some introductory comments on concepts of power, regions, the reorganization of the state and of multi-level governance, and governmentality, which help in understanding the issues surrounding regional devolution. I then examine the ways in which north-east England was politically and socially constructed as a particular type of region, with specific problems, in the 1930s , a move that has had lasting significance up until the present day. Moving on some six decades, I then examine contemporary claims about the relationship between regional devolution and regional economic success, which find fertile ground in the north-east precisely due to its long history of representation as a region with a unified regional interest. I then reflect on the processes of regional planning, regional strategies and regional devolution, and their relationship to regional economic regeneration. A brief conclusion follows, emphasizing that questions remain about the efficacy of the new governmentality and about who would be its main beneficiaries in the region. The extent to which devolution would actually involve transferring power to the region and the capacity of networked forms of power within the region to counter the structural power of capital and shape central state policies remains unclear. [source]


A study of Holocene floodplain particle size characteristics with special reference to palaeochannel infills from the upper Severn basin, Wales, UK

GEOLOGICAL JOURNAL, Issue 2 2001
Mark Patrick Taylor
Abstract Multiple sedimentary units from floodplain reaches at Welshpool on the upper River Severn and at the confluence of the Afon Tanat and Afon Vyrnwy (mid-Wales, UK) were examined to ascertain if they have distinctive particle size characteristics. Changes in particle size characteristics and their possible relationship to known human and climatic impacts are also discussed. Ellipse plots of particle size characteristics from the River Severn floodplain at Welshpool show that coarse-grained outwash deposits can be clearly discriminated from channel margin or palaeochannel sediments. In contrast, at the Afon Tanat,Vyrnwy study reach, this discrimination is not seen so clearly. The relationships between age and particle size characteristics from the most sampled sedimentary environment, palaeochannel infills, were also examined. The data from the River Severn floodplain at Welshpool show that palaeochannel sediments reveal a gradual but clear increase in particle size from the mid- to late Holocene towards the present day. Sediments deposited in the period 90,160 years BP are markedly coarser. It is suggested that these changes may be related to the combined effect of land-use changes, metal mining impacts and changes in flood frequency and magnitude that occurred at this time within the upper Severn basin. In contrast, the particle size characteristics of post Late Devensian/Early Holocene units from Tanat,Vyrnwy palaeochannels were random with no discernible age,size patterns. It is suggested that the non-systematic grain size distribution may be due to the steeper valley gradients of the Tanat,Vyrnwy system (and by inference higher stream powers) and its relatively narrow valley form enabling more effective coupling between coarser outwash deposits found on and at the edges of hillslopes and the valley floor. Although the two study reaches have undergone comparable environmental change during the Holocene and lie in the piedmont zone of their catchments, palaeochannel units of the same age possess distinctly different characteristics. Intrinsic reach-scale geomorphic factors would appear to preclude the uniform application of particle size characteristics to determine alluvial response to environmental change. Consequently, care needs to be applied to the use of such data for environmental discrimination because the phenomenon of equifinality means that a specific set of sediment characteristics is not necessarily exclusive to specific fluvial environments in either space or time. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Late-glacial and Holocene vegetation, climate and fire dynamics in the Serra dos Órgăos, Rio de Janeiro State, southeastern Brazil

GLOBAL CHANGE BIOLOGY, Issue 6 2010
HERMANN BEHLING
Abstract We present a high-resolution pollen and charcoal record of a 218 cm long sediment core from the Serra dos Órgăos, a subrange of the coastal Serra do Mar, located at 2130 m altitude in campos de altitude (high elevation grass- and shrubland) vegetation near Rio de Janeiro in southeastern Brazil to reconstruct past vegetation, climate and fire dynamics. Based on seven AMS 14C ages, the record represents at least the last 10 450 14C yr bp (12 380 cal years bp), The uppermost region was naturally covered by campos de altitude throughout the recorded period. Diverse montane Atlantic rain forest (ARF) occurred close to the studied peat bog at the end of the Late-glacial period. There is evidence of small Araucaria angustifolia populations in the study area as late as the early Holocene, after which point the species apparently became locally extinct. Between 10 380 and 10 170 14C yr bp (12 310,11 810 cal yr bp), the extent of campos de altitude was markedly reduced as montane ARF shifted rapidly upward to higher elevations, reflecting a very wet and warm period (temperatures similar to or warmer than present day) at the end of the Younger Dryas (YD) chronozone. This is in opposition to the broadly documented YD cooling in the northern Hemisphere. Reduced cross-equatorial heat transport and movement of the Intertropical Convergence Zone over northeastern Brazil may explain the YD warming. Markedly extended campos de altitude vegetation indicates dry climatic conditions until about 4910 14C yr bp (5640 cal yr bp). Later, wetter conditions are indicated by reduced high elevation grassland and the extension of ARF into higher elevation. Fire frequency was high during the early Holocene but decreased markedly after about 7020 14C yr bp (7850 cal yr bp). [source]


Simulation of seasonal precipitation and raindays over Greece: a statistical downscaling technique based on artificial neural networks (ANNs)

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 7 2007
K. Tolika
Abstract A statistical downscaling technique based on artificial neural network (ANN) was employed for the estimation of local changes on seasonal (winter, spring) precipitation and raindays for selected stations over Greece. Empirical transfer functions were derived between large-scale predictors from the NCEP/NCAR reanalysis and local rainfall parameters. Two sets of predictors were used: (1) the circulation-based 500 hPa and (2) its combination along with surface specific humidity and raw precipitation data (nonconventional predictor). The simulated time series were evaluated against observational data and the downscaling model was found efficient in generating winter and spring precipitation and raindays. The temporal evolution of the estimated variables was well captured, for both seasons. Generally, the use of the nonconventional predictors are attributed to the improvement of the simulated results. Subsequently, the present day and future changes on precipitation conditions were examined using large-scale data from the atmospheric general circulation model HadAM3P to the statistical model. The downscaled climate change signal for both precipitation and raindays, partly for winter and especially for spring, is similar to the signal from the HadAM3P direct output: a decrease of the parameters is predicted over the study area. However, the amplitude of the changes was different. Copyright © 2006 Royal Meteorological Society [source]


Oyster shucking technologies: past and present

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2006
Daniel E. Martin
Summary A review of oyster shucking technologies from the nineteenth century to the present day is presented, comparing advantages and disadvantages of various mechanical, thermal, pressure and other technologies. [source]


Theorizing Diaspora: Perspectives on "Classical" and "Contemporary" Diaspora

INTERNATIONAL MIGRATION, Issue 2 2004
Michele Reis
Cohen (1997) employed the term "classical" diaspora in reference to the Jews. Indeed, a vast corpus of work recognizes the Jewish people as examples of quintessential diasporic groups. However, a broader conceptualization of the term diaspora allows for the inclusion of immigrant communities that would be otherwise sidelined in the conventional literature on diaspora. This study is therefore a departure from the traditional diasporic literature, which tends to use the Jewish Diaspora as the archetype. It favours, rather, the classification of three principal broad historical waves in which the Jewish Diaspora can be interpreted as part of a classical period. The historicizing of diasporization for the purpose of this paper is achieved by an empirical discussion of the three major historical waves that influenced the diasporic process throughout the world: the Classical Period, the Modern Period, and the Contemporary or Late-modern Period. The paper discusses these three critical phases in the following manner: first, reference is made to the Classical Period, which is associated primarily with ancient diaspora and ancient Greece. The second historical phase analyses diaspora in relation to the Modern Period, which can be interpreted as a central historical fact of slavery and colonization. This section can be further subdivided into three large phases: (1) the expansion of European capital (1500,1814), (2) the Industrial Revolution (1815,1914), and (3) the Interwar Period (1914,1945). The final major period of diasporization can be considered a Contemporary or Late-modern phenomenon. It refers to the period immediately after World War II to the present day, specifying the case of the Hispanics in the United States as one key example. The paper outlines some aspects of the impact of the Latin American diaspora on the United States, from a socio-economic and politico-cultural point of view. While the Modern and Late-modern periods are undoubtedly the most critical for an understanding of diaspora in a modern, globalized context, for the purpose of this paper, more emphasis is placed on the latter period, which illustrates the progressive effect of globalization on the phenomenon of diasporization. The second period, the Modern Phase is not examined in this paper, as the focus is on a comparative analysis of the early Classical Period and the Contemporary or Late-modern Period. The incorporation of diaspora as a unit of analysis in the field of international relations has been largely neglected by both recent and critical scholarship on the subject matter. While a growing number of studies focus on the increasing phenomenon of diasporic communities, from the vantage of social sciences, the issue of diaspora appears to be inadequately addressed or ignored altogether. Certain key factors present themselves as limitations to the understanding of the concept, as well as its relevance to the field of international relations and the social sciences as a whole. This paper is meant to clarify some aspects of the definition of diaspora by critiquing the theories in the conventional literature, exposing the lacunae in terms of interpretation of diaspora and in the final analysis, establishing a historiography that may be useful in comparing certain features of "classical" diaspora and "contemporary" diaspora. The latter part of the paper is intended to provide illustrations of a contemporary diasporic community, using the example of Hispanics in the United States. [source]


Model-based uncertainty in species range prediction

JOURNAL OF BIOGEOGRAPHY, Issue 10 2006
Richard G. Pearson
Abstract Aim, Many attempts to predict the potential range of species rely on environmental niche (or ,bioclimate envelope') modelling, yet the effects of using different niche-based methodologies require further investigation. Here we investigate the impact that the choice of model can have on predictions, identify key reasons why model output may differ and discuss the implications that model uncertainty has for policy-guiding applications. Location, The Western Cape of South Africa. Methods, We applied nine of the most widely used modelling techniques to model potential distributions under current and predicted future climate for four species (including two subspecies) of Proteaceae. Each model was built using an identical set of five input variables and distribution data for 3996 sampled sites. We compare model predictions by testing agreement between observed and simulated distributions for the present day (using the area under the receiver operating characteristic curve (AUC) and kappa statistics) and by assessing consistency in predictions of range size changes under future climate (using cluster analysis). Results, Our analyses show significant differences between predictions from different models, with predicted changes in range size by 2030 differing in both magnitude and direction (e.g. from 92% loss to 322% gain). We explain differences with reference to two characteristics of the modelling techniques: data input requirements (presence/absence vs. presence-only approaches) and assumptions made by each algorithm when extrapolating beyond the range of data used to build the model. The effects of these factors should be carefully considered when using this modelling approach to predict species ranges. Main conclusions, We highlight an important source of uncertainty in assessments of the impacts of climate change on biodiversity and emphasize that model predictions should be interpreted in policy-guiding applications along with a full appreciation of uncertainty. [source]


Spatial and temporal variability in seed dynamics of machair sand dune plant communities, the Outer Hebrides, Scotland

JOURNAL OF BIOGEOGRAPHY, Issue 5 2001
N. W. Owen
Aim The subjects of seed banks and seed rain represent comparatively neglected areas of biogeography, yet at the community scale, exhibit interesting patterns in both space and time. This paper describes the seed bank and seed rain characteristics of the machair sand dune communities of the Outer Hebrides. As well as looking at individual species distributions and variability, the seed banks and seed rain are examined in terms of their detailed subcommunity composition and its local spatial and temporal variation. The machair plant (sub)communities show extensive degrees of anthropogenic modification because of past and present agricultural management, including cultivation for cereals over wide areas and for potatoes in large numbers of ,lazy beds' or small patches. Thus over the historical period, large areas of machair have undergone regular ploughing and cultivation, which have provided the opportunity for a patchwork of secondary succession to occur. This pattern continues to the present day. Furthermore, most other non-cultivated plant (sub)communities are intensively grazed, primarily by cattle and also by sheep and rabbits. Location South Uist, the Outer Hebrides, north-west Scotland. Methods At two carefully selected locations, a range of these various successional subcommunities have been sampled for their seed banks, by taking cores and for their seed rain, by using specially designed traps located where each seed bank sample was removed. This paired sampling strategy allowed direct comparison of the seed bank and the seed rain. Both individual species distributions and the community assemblages of seed bank/seed rain species are examined in space and time using techniques of numerical classification [two-way indicator species analysis (TWINSPAN)] and ordination [detrended correspondence analysis (DCA)]. Results and conclusions There is considerable heterogeneity within and between machair subcommunities in terms of seed bank and seed rain characteristics. The soil seed banks and seed rain of the agriculturally disturbed machair subcommunities are consistently more dense and more species rich than non-cultivated areas of the machair. Overall, machair seed banks are small and stable with no discernible seasonal trends in either size or species composition. In contrast, seed rain on the machair is characterized by a distinct temporal trend. Both seed banks and seed rain are potentially very poor sources of propagules for recolonization following disturbance, indicating that the majority of revegetation following anthropogenic and/or environmental interference is through vegetative reproduction. [source]


Nursing competence 10 years on: fit for practice and purpose yet?

JOURNAL OF CLINICAL NURSING, Issue 10 2008
Ann Bradshaw PhD, Dip N
Aims and objectives., This paper examines how nurses are prepared to be clinically competent and safe at registration, so that they are fit for practice and purpose. It follows up two papers on competence published in 1997 and 1998 and investigates subsequent developments. Background., In 1979, major changes in nursing affected nurse education and preparation for competence. In the following two decades, it became clear that nurses lacked clinical skills. This paper examines subsequent changes and asks the question whether this crucial shortcoming has now been remedied. This paper considers the background and context of change in nursing and nurse education in the 1980s. It looks at the new ideology, to prepare the ,knowledgeable doer' and examines the consequences of the change on nursing competency from the 1990s to the present day. Methods., This is a position paper. Professional policy documents from the English National Board for Nursing, Midwifery and Health Visiting, United Kingdom Central Council for Nursing, Midwifery and Health Visiting and Nursing and Midwifery Council, government reports and legislation on nursing and relevant nursing literature are examined and critically analysed and conclusions drawn. Conclusions., From 1923,1977, mandatory nursing syllabuses set by the General Nursing Council of England and Wales required the registered nurse to have acquired certain specific clinical skills. These were rigorously tested to an explicit standard set by the General Nursing Council before a nurse was awarded state registration. Twenty-five years later, the loss of this system for ensuring this competence and the implications of this loss, have been widely recognised. As a result, many nurse training institutions have introduced clinical skills laboratories, simulation of practice and the Objective Structured Clinical Examination. However, to the authors' surprise and contrary to their initial expectations, the Nursing and Midwifery Council has not made these systems uniform or mandatory and so still has no way of ensuring all nurse training is producing safe nurses in the United Kingdom. The authors conclude that the untested educational ideology that brought root and branch change to nurse training in 1983 and which failed to produce nurses ,fit for practice and purpose' may still prevail. Relevance to clinical practice., The present paper demonstrates that United Kingdom nurse training still has no uniform and mandatory system in place to ensure, as far as is possible, that all registered nurses are clinically competent and safe to practice. [source]


The history and control of the pine beauty moth, Panolis flammea (D. & S.) (Lepidoptera: Noctuidae), in Scotland from 1976 to 2000

AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2001
B. J. Hicks
Abstract 1,The pine beauty moth, Panolis flammea, has been a serious pest of lodgepole pine plantations in Scotland since 1976. It historically feeds on native Scots pine throughout Europe but population levels of P. flammea on this host have never been high enough to cause tree mortality in the U.K. 2,This paper reviews recent advances in the biology of the pest and documents control programmes from 1976 to 1999. 3,There has been practically uninterrupted population monitoring of P. flammea from 1977 to the present day in Scottish lodgepole pine plantations. Intervention with chemical spraying has often been necessary. 4,The population data suggest that populations of P. flammea may have had a cyclic pattern over the monitoring period, with outbreaks occurring at regular intervals of between 6 and 7 years. 5,The amplitude of population cycles was large during the 1970s and 1980s, but has dampened in recent years. Natural enemies are believed to contribute to this trend. Fungal disease, specifically, appears to have had a greater effect on pest populations in recent years than in the past and is suggested to have contributed significantly to the population dynamics observed since 1990. [source]


A history and review of school meal standards in the UK

JOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 2 2009
C. E. L. Evans
Abstract This review details the history of school meals in the UK, from their origin in the mid-19th Century, to the present day, and provides a summary of how each country has independently developed its own food and or nutrient-based standards for school meals. The standards in place in the UK are amongst some of the most detailed and comprehensive in the world. Regular monitoring to ensure that these standards are being met and that schools are improving healthy eating is essential to their success. Of no lesser importance are assessments to determine whether changes to school meals are having an impact on the diets of school children. It is early days in terms of evaluation because food-based standards have only recently been introduced and nutrient-based standards are in the process of being developed and implemented. Studies in England provide some evidence that the re-introduction of standards for school food is having a positive impact on both pupil's food choices and the nutritional profile of school lunches. At present, there does not appear to be a pattern between current obesity levels and the types of school meals provided, although it is anticipated that, in the long term, these comprehensive standards may contribute to a less obesogenic environment. [source]


Late Quaternary vegetation, climate and fire dynamics inferred from the El Tiro record in the southeastern Ecuadorian Andes,

JOURNAL OF QUATERNARY SCIENCE, Issue 3 2008
Holger Niemann
Abstract In order to study the stability and dynamics of mountain rainforest and paramo ecosystems, including the biodiversity of these ecosystems, the Holocene and late Pleistocene climate and fire variability, and human impact in the southeastern Ecuadorian Andes, we present a high-resolution pollen record from El Tiro Pass (2810,m elevation), Podocarpus National Park. Palaeoenvironmental changes, investigated by pollen, spores and charcoal analysis, inferred from a 127,cm long core spanning the last ca. 21,000,cal. yr BP, indicate that grass-paramo was the main vegetation type at the El Tiro Pass during the late Pleistocene period. The grass-paramo was rich in Poaceae, Plantago rigida and Plantago australis, reflecting cold and moist climatic conditions. During the early Holocene, from 11,200 to 8900,cal. yr BP, subparamo and upper mountain rainforest vegetation expanded slightly, indicating a slow warming of climatic conditions during this period. From 8900 to 3300,cal. yr BP an upper mountain rainforest developed at the study site, indicated by an increase in Hedyosmun, Podocarpaceae, Myrsine and Ilex. This suggests a warmer climate than the present day at this elevation. The modern subparamo vegetation became established since 3300,cal. yr BP at El Tiro Pass. Fires, probably anthropogenic origin, were very rare during the late Pleistocene but became frequent after 8000,cal. yr BP. Copyright © 2007 John Wiley & Sons, Ltd. [source]


The Quaternary is here to stay,

JOURNAL OF QUATERNARY SCIENCE, Issue 1 2007
D. Q. Bowen
Abstract The proposals to drop the name Quaternary, to extend the Neogene Period to the present day, and to confirm the base of the Pleistocene at 1.8,Ma are reviewed. It is concluded that there is no scientific case for dropping the name Quaternary and that an overwhelming volume of evidence points to 2.6,Ma as the most appropriate base for the Quaternary/Pleistocene, when extensive Northern Hemisphere mid-latitude glaciation occurred under what were essentially similar physical boundary conditions of continents, oceans, seaways and mountain ranges that characterise, and are unique to, the Quaternary. It is desirable that all stratigraphical and geochronological evidence is tied rigorously into the Global Stratigraphic Timescale. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Late Quaternary deglaciation and climate history of the Larsemann Hills (East Antarctica)

JOURNAL OF QUATERNARY SCIENCE, Issue 4 2004
Elie Verleyen
Abstract The Late Quaternary climate history of the Larsemann Hills has been reconstructed using siliceous microfossils (diatoms, chrysophytes and silicoflagellates) in sediment cores extracted from three isolation lakes. Results show that the western peninsula, Stornes, and offshore islands were ice-covered between 30,000,yr,BP and 13,500,cal.,yr,BP. From 13,500,cal.,yr,BP (shortly after the Antarctic Cold Reversal) the coastal lakes of the Larsemann Hills were deglaciated and biogenic sedimentation commenced. Between 13,500 and 11,500,cal.,yr,BP conditions were warmer and wetter than during the preceding glacial period, but still colder than today. From 11,500 to 9500,cal.,yr,BP there is evidence for wet and warm conditions, which probably is related to the early Holocene climate optimum, recorded in Antarctic ice cores. Between 9500 and 7400,cal.,yr,BP dry and cold conditions are inferred from high lake-water salinities, and low water levels and an extended duration of nearshore sea-ice. A second climate optimum occurred between 7400 and 5230,cal.,yr,BP when stratified, open water conditions during spring and summer characterised the marine coast of Prydz Bay. From 5230 until 2750,cal.,yr,BP sea-ice duration in Prydz Bay increased, with conditions similar to the present day. A short return to stratified, open water conditions and a reduction in nearshore winter sea-ice extent is evident between 2750 and 2200,cal.,yr,BP. Simultaneously, reconstructions of lake water depth and salinity suggests relatively humid and warm conditions on land between 3000 and 2000,cal.,yr,BP, which corresponds to a Holocene Hypsithermal reported elsewhere in Antarctica. Finally, dry conditions are recorded around 2000, between 760 and 690, and between 280 and 140,cal.,yr,BP. These data are consistent with ice-core records from Antarctica and support the hypothesis that lacustrine and marine sediments on land can be used to evaluate the effect of long-term climate change on the terrestrial environment. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Mid- to late Holocene relative sea-level change in Poole Harbour, southern England

JOURNAL OF QUATERNARY SCIENCE, Issue 3 2001
Robin J. Edwards
Abstract A foraminiferal transfer function for mean tide level (MTL) is used in combination with AMS radiocarbon dated material to construct a record of relative sea-level (RSL) change from Poole Harbour, southern Britain. These new data, based on multiple cores from duplicate sites, indicate four phases of change during the last 5000 cal. (calendar) yr: (i) rising RSL between ca. 4700 cal. yr BP and ca. 2400 cal. yr BP; (ii) stable to falling RSL from ca. 2400 cal. yr BP until ca. 1200 cal. yr BP; (iii) a brief rise in RSL from ca. 1200 cal. yr BP to ca. 900 cal. yr BP, followed by a period of stability; (iv) a recent increase in the rate of RSL rise from ca. 400,200 cal. yr BP until the present day. In addition, they suggest that the region has experienced long-term crustal subsidence at a rate of 0.5 mm C14 yr,1. Although this can account for the overall rise in MTL observed during the past 2500 yr, it fails to explain the changes in the rate of rise during this period. This implies that the phases of RSL change recorded in the marshes of Poole Harbour reflect tidal range variations or ,eustatic' fluctuations in sea-level. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Raman spectroscopy in art and archaeology

JOURNAL OF RAMAN SPECTROSCOPY, Issue 8 2008
Pietro Baraldi
Abstract This paper introduces presentations given at the fourth International Conference on the Application of Raman Spectroscopy in Art and Archaeology, held in Modena, Italy, in the Ducal Palace, on 5,8 September 2007. The subjects of lectures and posters presented were concerned mainly with the new applications of Raman microscopy and other Raman techniques to more problematic samples, such as lakes, inks, and fluorescent dyes. Chronologically, the applications extended from the 10th century BC to the present day. The areas considered in the research were wide-ranging in terms of subject-matter and also geographically. New techniques have been developed for the study of binders in paintings and lakes, and with movable instrumentation on unmovable samples. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Historical and theoretical perspectives in language policy and planning

JOURNAL OF SOCIOLINGUISTICS, Issue 2 2000
Thomas Ricento
This paper explores the evolution of language policy and planning (LPP) as an area of research from the end of World War II to the present day. Based on analysis of the LPP literature, three types of factors are identified as having been instrumental in shaping the field. These factors , macro sociopolitical, epistemological, and strategic , individually and interactively have influenced the kinds of questions asked, methodologies adopted, and goals aspired to in LPP research. Research in LPP is divided into three historical phases: (1) decolonization, structuralism, and pragmatism; (2) the failure of modernization, critical sociolinguistics, and access; and (3) the new world order, postmodernism, and linguistic human rights. The article concludes with a discussion of current research trends and areas requiring further investigation. [source]


Schizophrenia as split personality/Jekyll and Hyde: The origins of the informal usage in the English language

JOURNAL OF THE HISTORY OF THE BEHAVIORAL SCIENCES, Issue 1 2007
Kieran McNally
The entry into the English language of the informal usage of schizophrenia as split per-sonality/Jekyll and Hyde is traced and commented upon. The metaphor of split personality is followed from Eugene Bleuler via his translators and the wider psychiatric community into the present day. It, and to a lesser extent the Jekyll-Hyde personality, is found to be as much a product of the psychological professions as a product of lay misinterpretation. The informal definition of schizophrenia as split personality has outlived the scientific theory with which it was initially associated. © 2007 Wiley Periodicals, Inc. [source]