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Showing papers by "University of East Anglia published in 2000"


Journal ArticleDOI
22 Jun 2000-Nature
TL;DR: The present genetic structure of populations, species and communities has been mainly formed by Quaternary ice ages, and genetic, fossil and physical data combined can greatly help understanding of how organisms were so affected.
Abstract: Global climate has fluctuated greatly during the past three million years, leading to the recent major ice ages. An inescapable consequence for most living organisms is great changes in their distribution, which are expressed differently in boreal, temperate and tropical zones. Such range changes can be expected to have genetic consequences, and the advent of DNA technology provides most suitable markers to examine these. Several good data sets are now available, which provide tests of expectations, insights into species colonization and unexpected genetic subdivision and mixture of species. The genetic structure of human populations may be viewed in the same context. The present genetic structure of populations, species and communities has been mainly formed by Quaternary ice ages, and genetic, fossil and physical data combined can greatly help our understanding of how organisms were so affected.

6,341 citations


Journal ArticleDOI
TL;DR: In this paper, the authors define social resilience as the ability of groups or communities to cope with external stresses and disturbances as a result of social, political and environmental change, and explore potential links between social resilience and ecological resilience.
Abstract: This article defines social resilience as the ability of groups or communities to cope with external stresses and disturbances as a result of social, political and environmental change. This definition highlights social resilience in relation to the concept of ecological resilience which is a characteristic of ecosystems to maintain themselves in the face of disturbance. There is a clear link between social and ecological resilience, particularly for social groups or communities that are dependent on ecological and environmental resources for their livelihoods. But it is not clear whether resilient ecosystems enable resilient communities in such situations. This article examines whether resilience is a useful characteristic for describing the social and economic situation of social groups and explores potential links between social resilience and ecological resilience. The origins of this interdisciplinary study in human ecology, ecological economics and rural sociology are reviewed, and a study of the impacts of ecological change on a resource- dependent community in contemporary coastal Vietnam in terms of the resilience of its institu- tions is outlined. I Introduction The concept of resilience is widely used in ecology but its meaning and measurement are contested. This article argues that it is important to learn from this debate and to explore social resilience, both as an analogy of how societies work, drawing on the ecological concept, and through exploring the direct relationship between the two phenomena of social and ecological resilience. Social resilience is an important component of the circumstances under which individuals and social groups adapt to environmental change. Ecological and social resilience may be linked through the dependence on ecosystems of communities and their economic activities. The question is, then, whether societies dependent on resources and ecosystems are themselves less resilient. In addition, this analysis allows consideration of whether institutions

3,732 citations


Journal ArticleDOI
TL;DR: In this paper, the authors describe the construction of a 0.58-latent-long gridded dataset of monthly terrestrial surface climate for the period of 1901-96, which consists of seven climate elements: precipitation, mean temperature, diurnal temperature range, wet-day frequency, vapor pressure, cloud cover, and ground frost frequency.
Abstract: The authors describe the construction of a 0.58 lat‐long gridded dataset of monthly terrestrial surface climate for the period of 1901‐96. The dataset comprises a suite of seven climate elements: precipitation, mean temperature, diurnal temperature range, wet-day frequency, vapor pressure, cloud cover, and ground frost frequency. The spatial coverage extends over all land areas, including oceanic islands but excluding Antarctica. Fields of monthly climate anomalies, relative to the 1961‐90 mean, were interpolated from surface climate data. The anomaly grids were then combined with a 1961‐90 mean monthly climatology (described in Part I) to arrive at grids of monthly climate over the 96-yr period. The primary variables—precipitation, mean temperature, and diurnal temperature range—were interpolated directly from station observations. The resulting time series are compared with other coarser-resolution datasets of similar temporal extent. The remaining climatic elements, termed secondary variables,were interpolated from merged datasets comprising station observations and, in regions where there were no station data, synthetic data estimated using predictive relationships with the primary variables. These predictive relationships are described and evaluated. It is argued that this new dataset represents an advance over other products because (i) it has higher spatial resolution than other datasets of similar temporal extent, (ii) it has longer temporal coverage than other products of similar spatial resolution, (iii) it encompasses a more extensive suite of surface climate variables than available elsewhere, and (iv) the construction method ensures that strict temporal fidelity is maintained. The dataset should be of particular relevance to a number of applications in applied climatology, including large-scale biogeochemical and hydrological modeling, climate change scenario construction, evaluation of regional climate models, and comparison with satellite products. The dataset is available from the Climatic Research Unit and is currently being updated to 1998.

2,106 citations


Journal ArticleDOI
TL;DR: In this article, the authors discuss approaches to the assessment of vulnerability to climatevariability and change and attempt to clarify the relationship between the concepts of vulnerability and adaptation, focusing on the socio-economic and institutional constraints that limit the capacity to respond.
Abstract: We discuss approaches to the assessment of vulnerability to climatevariability and change andattempt to clarify the relationship between the concepts of vulnerability andadaptation. In searchof a robust, policy-relevant framework, we define vulnerability in terms ofthe capacity ofindividuals and social groups to respond to, that is, to cope with, recoverfrom or adapt to, anyexternal stress placed on their livelihoods and well-being. The approach thatwe develop placesthe social and economic well-being of society at the centre of the analysis,focussing on thesocio-economic and institutional constraints that limit the capacity torespond. From thisperspective, the vulnerability or security of any group is determined byresource availability andby the entitlement of individuals and groups to call on these resources. Weillustrate theapplication of this approach through the results of field research in coastalVietnam, highlightingshifting patterns of vulnerability to tropical storm impacts at the household-and community-levelin response to the current process of economic renovation and drawingconclusions concerningmeans of supporting the adaptive response to climate stress. Four prioritiesfor action areidentified that would improve the situation of the most exposed members ofmany communities:poverty reduction; risk-spreading through income diversification; respectingcommon propertymanagement rights; and promoting collective security. A sustainable response,we argue, mustalso address the underlying causes of social vulnerability, including theinequitable distributionof resources.

1,449 citations


Journal ArticleDOI
12 Oct 2000-Nature
TL;DR: It is demonstrated that iron supply controls phytoplankton growth and community composition during summer in these polar Southern Ocean waters, but the fate of algal carbon remains unknown and depends on the interplay between the processes controlling export, remineralisation and timescales of water mass subduction.
Abstract: Changes in iron supply to oceanic plankton are thought to have a significant effect on concentrations of atmospheric carbon dioxide by altering rates of carbon sequestration, a theory known as the 'iron hypothesis' For this reason, it is important to understand the response of pelagic biota to increased iron supply Here we report the results of a mesoscale iron fertilization experiment in the polar Southern Ocean, where the potential to sequester iron-elevated algal carbon is probably greatest Increased iron supply led to elevated phytoplankton biomass and rates of photosynthesis in surface waters, causing a large drawdown of carbon dioxide and macronutrients, and elevated dimethyl sulphide levels after 13 days This drawdown was mostly due to the proliferation of diatom stocks But downward export of biogenic carbon was not increased Moreover, satellite observations of this massive bloom 30 days later, suggest that a sufficient proportion of the added iron was retained in surface waters Our findings demonstrate that iron supply controls phytoplankton growth and community composition during summer in these polar Southern Ocean waters, but the fate of algal carbon remains unknown and depends on the interplay between the processes controlling export, remineralisation and timescales of water mass subduction

1,412 citations


Book
01 Jan 2000
TL;DR: In this paper, the authors describe research linking micro-level outcomes to macro-level strategies with respect to rural poverty reduction in Kenya, set against a background in which a new government, elected at the end of 2002, is wrestling with how to break away decisively from previously unfavourable norms in the conduct of public life.
Abstract: This article describes research linking micro-level outcomes to macro-level strategies with respect to rural poverty reduction in Kenya. It is set against a background in which a new government, elected at the end of 2002, is wrestling with how to break away decisively from previously unfavourable norms in the conduct of public life. The research undertaken in ten villages in Suba and Bomet districts in 2001 and 2002 confirms governance problems as having a broadly debilitating effect on rural livelihoods. Rolling back this pattern of public service behaviour needs to be made a priority; otherwise national goals to improve education, health and the transport infrastructure will reap significantly lower gains than are potentially possible.

768 citations


Journal ArticleDOI
TL;DR: In this article, an integrated wetland research framework suggests that a combination of economic valuation, integrated modelling, stakeholder analysis, and multi-criteria evaluation can provide complementary insights into sustainable and welfare-optimising wetland management and policy.

659 citations


Journal ArticleDOI
11 Nov 2000-BMJ
TL;DR: Long term therapy with aspirin is associated with a significant increase in the incidence of gastrointestinal haemorrhage, and no evidence exists that reducing the dose or using modified release formulations would reduce the incidence.
Abstract: Objectives: To assess the incidence of gastrointestinal haemorrhage associated with long term aspirin therapy and to determine the effect of dose reduction and formulation on the incidence of such haemorrhage. Design: Meta-analysis of 24 randomised controlled trials (almost 66 000 participants). Intervention: Aspirin compared with placebo or no treatment, for a minimum of one year. Main outcome measures: Incidence of gastrointestinal haemorrhage. Results: Gastrointestinal haemorrhage occurred in 2.47% of patients taking aspirin compared with 1.42% taking placebo (odds ratio 1.68; 95% confidence interval 1.51 to 1.88); the number needed to harm was 106 (82 to 140) based on an average of 28 months9 therapy. At doses below 163 mg/day, gastrointestinal haemorrhage occurred in 2.30% of patients taking aspirin compared with 1.45% taking placebo (1.59; 1.40 to 1.81). Meta-regression showed no relation between gastrointestinal haemorrhage and dose. For modified release formulations of aspirin the odds ratio was 1.93 (1.15 to 3.23). Conclusions: Long term therapy with aspirin is associated with a significant increase in the incidence of gastrointestinal haemorrhage. No evidence exists that reducing the dose or using modified release formulations would reduce the incidence of gastrointestinal haemorrhage.

648 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the response of the Arctic Ocean to annual and longer-period changes in the North Atlantic oscillation (NAO), focusing on the winter season when the forcing is maximal and on the postwar period.
Abstract: The climatically sensitive zone of the Arctic Ocean lies squarely within the domain of the North Atlantic oscillation (NAO), one of the most robust recurrent modes of atmospheric behavior. However, the specific response of the Arctic to annual and longer-period changes in the NAO is not well understood. Here that response is investigated using a wide range of datasets, but concentrating on the winter season when the forcing is maximal and on the postwar period, which includes the most comprehensive instrumental record. This period also contains the largest recorded low-frequency change in NAO activity—from its most persistent and extreme low index phase in the 1960s to its most persistent and extreme high index phase in the late 1980s/early 1990s. This longperiod shift between contrasting NAO extrema was accompanied, among other changes, by an intensifying storm track through the Nordic Seas, a radical increase in the atmospheric moisture flux convergence and winter precipitation in this sector, an increase in the amount and temperature of the Atlantic water inflow to the Arctic Ocean via both inflow branches (Barents Sea Throughflow and West Spitsbergen Current), a decrease in the late-winter extent of sea ice throughout the European subarctic, and (temporarily at least) an increase in the annual volume flux of ice from the Fram Strait.

604 citations


Journal ArticleDOI
TL;DR: Recent progress on the characterization of the Tat system is reviewed and the structure and operation of this major new bacterial protein export pathway is critically discussed.
Abstract: The Tat (twin-arginine translocation) system is a bacterial protein export pathway with the remarkable ability to transport folded proteins across the cytoplasmic membrane. Preproteins are directed to the Tat pathway by signal peptides that bear a characteristic sequence motif, which includes consecutive arginine residues. Here, we review recent progress on the characterization of the Tat system and critically discuss the structure and operation of this major new bacterial protein export pathway.

564 citations


Journal ArticleDOI
TL;DR: It is amongst the Bacteria and Archaea that respiratory flexibility can be found at its most extreme and contributes to the ability of prokaryotes to colonize many of Earth’s most hostile microoxic and anoxic environments.
Abstract: The respiration of oxygen is fundamental to the life of higher animals and plants. The basic respiratory process in the mitochondria of these organisms involves the donation of electrons by low-redox-potential electron donors such as NADH. This is followed by electron transfer through a range of redox cofactors, bound to integral membrane or membrane-associated protein complexes. The process terminates in the reduction of the high-redox-potential electron acceptor, oxygen (Fig. 1). The free energy released during this electrontransfer process is used to drive the translocation of protons across the mitochondrial membrane to generate a trans-membrane proton electrochemical gradient or protonmotive force (∆p) that can drive the synthesis of ATP (Fig. 1). The respiratory flexibility of the mammalian mitochondrion is rather poor. There is some flexibility at the level of electron input (Fig. 1), but none at the level of electron output where cytochrome aa $ oxidase provides the only means of oxygen reduction. In the case of plant mitochondria, a slightly greater degree of respiratory flexibility is encountered with a number of alternative NADH dehydrogenases and two oxidases being apparent. This respiratory flexibility affords plant mitochondria with the capacity to contribute to processes other than the generation of ATP. For example, electron transfer from the alternative NADH dehydrogenase to the alternative oxidase is not coupled to the generation of ∆p and instead serves to release energy as heat, which can volatilize insect attractants to aid pollination. In the American skunk cabbage this same mechanism for heat production serves to permit growth at subzero temperatures (Nicholls & Ferguson, 1992). There is also some respiratory flexibility in the mitochondria of yeast, filamentous fungi and ancient protozoa, but it is amongst the Bacteria and Archaea that respiratory flexibility can be found at its most extreme. In these organisms, a diverse range of electron acceptors can be utilized including elemental sulphur and sulphur oxyanions (Hamilton, 1998), organic sulphoxides and sulphonates (Lie et al., 1999; McAlpine et al., 1998), nitrogen oxy-anions and nitrogen oxides (Berks et al., 1995), organic N-oxides (Czjzek et al., 1998), halogenated organics (Dolfing, 1990; Louie & Mohn, 1999; van de Pas et al., 1999), metalloid oxy-anions such as selenate and arsenate (Krafft & Macy, 1998; Macy et al., 1996, 1993; Schroder et al., 1997), transition metals such as Fe(III) and Mn(IV) (Lovley, 1991), and radionuclides such as U(VI) (Lovley & Phillips, 1992) and Tc(VII) (Lloyd et al., 1999). This respiratory diversity can be found amongst pyschrophiles, mesophiles and hyperthermophiles and contributes to the ability of prokaryotes to colonize many of Earth’s most hostile microoxic and anoxic environments.

Journal ArticleDOI
TL;DR: In this article, the authors used tree-ring sample collections across the traditional research areas of North America and Europe, and the start of major developments in many new areas of Eurasia, South America and Australasia.

Journal ArticleDOI
TL;DR: In this paper, the authors used a standardized series of line-transect censuses conducted over a 10-year period to examine the effects of subsistence game harvest on the structure of vertebrate communities in 25 Amazonian forest sites subjected to varying levels of hunting pressure.
Abstract: Subsistence hunting affects vast tracts of tropical wilderness that otherwise remain structurally unal- tered, yet distinguishing hunted from nonhunted tropical forests presents a difficult problem because this diffuse form of resource extraction leaves few visible signs of its occurrence. I used a standardized series of line-transect censuses conducted over a 10-year period to examine the effects of subsistence game harvest on the structure of vertebrate communities in 25 Amazonian forest sites subjected to varying levels of hunting pressure. Crude verte- brate biomass, which was highly correlated with hunting pressure, gradually declined from nearly 1200 kg km 2 2 at nonhunted sites to less than 200 kg km 2 2 at heavily hunted sites. Hunting had a negative effect on the total biomass and relative abundance of vertebrate species in different size classes at these forest sites, but it did not af- fect their overall density. In particular, persistent hunting markedly reduced the density of large-bodied game spe- cies ( . 5 kg), which contributed a large proportion of the overall community biomass at nonhunted sites (65- 78%) and lightly hunted sites (55-71%). Nutrient-rich floodplain forests contained a consistently greater game biomass than nutrient-poor unflooded forests, once I controlled for the effects of hunting pressure. Conservative estimates of game yields indicate that as many as 23.5 million game vertebrates, equivalent to 89,224 tons of bushmeat with a market value of US$190.7 million, are consumed each year by the rural population of Brazil- ian Amazonia, which illustrates the enormous socioeconomic value of game resources in the region. My cross- site comparison documents the staggering effect of subsistence hunters on tropical forest vertebrate communities and highlights the importance of considering forest types and forest productivity in game management pro- grams.

Journal ArticleDOI
TL;DR: In this paper, the authors give an overview of the state of the art of environmental value transfer, discuss its prospects and potential role in CBA as a decision-support tool, and provide further guidelines for proper use and application.

Journal ArticleDOI
12 Oct 2000-Nature
TL;DR: Data are reported from a whole-ecosystem test of the iron-limitation hypothesis in the Southern Ocean, which show that surface uptake of atmospheric CO 2 and uptake ratios of silica to carbon by phytoplankton were strongly influenced by nanomolar increases of iron concentration.
Abstract: Photosynthesis by marine phytoplankton in the Southern Ocean, and the associated uptake of carbon, is thought to be currently limited by the availability of iron1,2. One implication of this limitation is that a larger iron supply to the region in glacial times3 could have stimulated algal photosynthesis, leading to lower concentrations of atmospheric CO2. Similarly, it has been proposed that artificial iron fertilization of the oceans might increase future carbon sequestration. Here we report data from a whole-ecosystem test of the iron-limitation hypothesis in the Southern Ocean4, which show that surface uptake of atmospheric CO2 and uptake ratios of silica to carbon by phytoplankton were strongly influenced by nanomolar increases of iron concentration. We use these results to inform a model of global carbon and ocean nutrients, forced with atmospheric iron fluxes to the region derived from the Vostok3 ice-core dust record. During glacial periods, predicted magnitudes and timings of atmospheric CO2 changes match ice-core records well. At glacial terminations, the model suggests that forcing of Southern Ocean biota by iron caused the initial ∼40 p.p.m. of glacial–interglacial CO2 change, but other mechanisms must have accounted for the remaining 40 p.p.m. increase. The experiment also confirms that modest sequestration of atmospheric CO2 by artificial additions of iron to the Southern Ocean is in principle possible, although the period and geographical extent over which sequestration would be effective remain poorly known.

Journal ArticleDOI
TL;DR: This work examined two time series of species-specific surveys of a relatively stable skate fishery in the northeast Atlantic and revealed the disappearance of two skate species and confirmed a previously documented decline of the common skate.
Abstract: Skates are arguably the most vulnerable of exploited marine fishes. Their vutlnerability is often as- sessed by examiningfisheries catch trends, but these data are not generally recorded on a species basis except in France. Aggregated skate catch statistics tend to exhibit more stable trends than those of other elasnmo- branch fisheries. We tested whether such apparent stability in aggregated catch trends could mask population declines of individual species. We examined two time series of species-specific surveys of a relatively stable skate fishery in the northeast Atlantic. These surveys revealed the disappearance of two skate species, long- nose skate (Dipturus oxyrhinchus) and white skate (Rostroraja alba) and confirmed a previously documented decline of the common skate (D. batis). Of the remaining five skate species, the three larger ones have de- clined, whereas twvo smaller species have increased in abundance. The increase in abundance and biomass of the smaller species has resulted in the stability of the aggregated catch trends. Becatuse there is significant di- etary overlap among species, we suiggest the increase in abundance of the smaller species ma) be due to com-

Journal ArticleDOI
TL;DR: A systems view of the organizational preconditions to technological accidents and disasters, and in particular the seminal “Man-made Disasters model” proposed by the late Professor Barry Turner is presented.

Journal ArticleDOI
TL;DR: In this paper, the intensity distribution of daily precipitation amounts in the UK has changed over the period 1961-1995, becoming on average more intense in winter and less intense in summer.
Abstract: The intensity distribution of daily precipitation amounts in the UK has changed over the period 1961–1995, becoming on average more intense in winter and less intense in summer. This result is based on an analysis of 110 UK station records. In winter, and in terms of their relative contributions to total winter precipitation, there has been a decline in light and medium events and an increase in the heaviest events. This change is fairly uniform across the whole country and is apparent even when longer records (with reduced spatial coverage/detail) are analysed back to 1931 or 1908. The reverse is found in summer: over 1961–1995 there has been a decline in the proportion of the seasonal total being provided by the heaviest events. In the longer term context, however, the summer changes appear to be a return to earlier levels after a period in the 1960s when heavy summer rainfall made a greater than normal contribution. More complex changes have occurred in the intensity distribution of spring and autumn precipitation, with opposite changes in different regions of the UK. Copyright © 2000 Royal Meteorological Society

Journal ArticleDOI
TL;DR: In this paper, an objective classification scheme of the atmospheric circulation affecting Portugal, between 1946 and 1990, is presented, where daily circulation is characterized through the use of a set of indices associated with the direction and vorticity of the geostrophic flow.
Abstract: An objective classification scheme of the atmospheric circulation affecting Portugal, between 1946 and 1990, is presented, where daily circulation is characterized through the use of a set of indices associated with the direction and vorticity of the geostrophic flow. The synoptic characteristics and the frequency of ten basic circulation weather types (CWTs) are discussed, as well as the amount of precipitation associated with each type between 1957 and 1986. It is shown that the anticyclonic (A) type, although being the most frequent class in winter (37%), gives a rather small (less then 16%) contribution to the winter precipitation amount, observed on a daily basis. On the other hand, the three wettest CWTs, namely the cyclonic (C), southwesterly (SW) and westerly (W) types, together representing only 32% of all winter days, account for more than 62% of the observed daily precipitation. Results obtained highlight the existence of strong links between the interannual variability of monthly precipitation and interannual variability of CWTs. Multiple regression models, developed for 18 stations, show the ability of modelling monthly winter precipitation through the exclusive use, as predictors, of the wet CWTs (i.e. C, SW and W). The observed decreasing trend of March precipitation is also analysed and shown to be especially associated with the decrease of the three wet weather types. The anomalous low (high) frequency of wet CWTs during the hydrological year is shown to be strongly related with the occurrence of extreme dry (wet) years in Portugal, which had important impacts on Portuguese agriculture. Overall, the results suggest that the precipitation regime over Portugal, including interannual variability, trends and extremes, may be adequately explained in terms of variability of a fairly small number of circulation weather patterns. On the other hand, observed contrasts in the spatial distribution of correlations between frequency of wet CWTs and rainfall amounts suggest that precipitation regimes are of a different nature in northern and southern regions of Portugal; the former possessing an orographic origin and the latter being associated to cyclogenetic activity. Copyright © 2000 Royal Meteorological Society.

Journal ArticleDOI
TL;DR: In the study population, the annual incidence of PSV is slowly increasing with time and the incidence is greatest in the elderly, with an overall peak in the 65-74 age group.
Abstract: Objective To describe the epidemiology of the primary systemic vasculitides (PSV; Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, polyarteritis nodosa) in a well-defined population over a 10-year period. Methods An inception cohort of patients from the Norwich Health Authority (NHA) who were >15 years of age and had PSV first diagnosed between January 1, 1988 and December 31, 1997 was collected. Incidence rates were adjusted for age and sex to the 1992 population. The prevalence of PSV in this cohort was estimated on December 31, 1997. Patients were classified according to the American College of Rheumatology 1990 vasculitis criteria and the Chapel Hill Consensus definitions. Results Eighty-two NHA residents fulfilled the inclusion criteria. There were 47 men and 35 women, with a mean age of 62.9 years (median 65.0 years). The overall annual incidence of PSV among NHA residents was 19.8/million (95% confidence interval [95% CI] 15.8–24.6). The point prevalence on December 31, 1997 was 144.5/million (95% CI 110.4–185.3). PSV was more common in males (23.5/million; 95% CI 17.3–31.3) than females (16.4/million; 95% CI 11.4–22.8). The age- and sex-specific incidence showed a clear increase with age, with an overall peak in the 65–74 year age group (60.1/million). Conclusion In our study population, the annual incidence of PSV is slowly increasing with time and the incidence is greatest in the elderly.

Journal ArticleDOI
TL;DR: TIMP‐1 inhibition of ADAM‐10 could prove useful in distinguishing its activity from that of TACE, which is only inhibited by TIMP‐3, in cell based assays.

Journal ArticleDOI
TL;DR: An understanding of island colonization and diversification can best be developed from an ecosystem level synthesis as more data for the Canarian archipelago come to hand.
Abstract: Recently, the Canary Islands have become a focus for studies of the colonization and the diversification of different organisms. Some authors have considered Canarian endemisms as relicts of Tertiary origin, but new molecular data suggest a general pattern of continental dispersion followed by in situ speciation. Recent phylogeographic studies are revealing variants of the simple stepping-stone colonization model that seems to hold for many Hawaiian groups. Many factors can generate deviations from such a pattern: the stochastic nature of colonization, competitive exclusion, phylogenetic constraints on adaptive evolution and extinction. An understanding of island colonization and diversification can best be developed from an ecosystem level synthesis as more data for the Canarian archipelago come to hand.

Journal ArticleDOI
TL;DR: In this article, a study explores how teleworking is perceived by employees and highlights its possible benefits and pitfalls, and examines teleworking impact on effectiveness, quality of working life, and family life.
Abstract: This study explores how teleworking is perceived by employees and highlights its possible benefits and pitfalls. Interviews with sixty-two teleworkers in five UK organisations provide a comprehensive view on this mode of work. In particular the study examines teleworking impact on effectiveness, quality of working life, and family life.

Journal ArticleDOI
TL;DR: The results demonstrate the existence of highly regulated mechanisms that can rapidly convert syndecans from cell surface receptors or coreceptors to soluble heparan sulfate proteoglycan effectors.
Abstract: The syndecan family of four transmembrane heparan sulfate proteoglycans binds a variety of soluble and insoluble extracellular effectors. Syndecan extracellular domains (ectodomains) can be shed intact by proteolytic cleavage of their core proteins, yielding soluble proteoglycans that retain the binding properties of their cell surface precursors. Shedding is accelerated by PMA activation of protein kinase C, and by ligand activation of the thrombin (G-protein–coupled) and EGF (protein tyrosine kinase) receptors (Subramanian, S.V., M.L. Fitzgerald, and M. Bernfield. 1997. J. Biol. Chem. 272:14713–14720). Syndecan-1 and -4 ectodomains are found in acute dermal wound fluids, where they regulate growth factor activity (Kato, M., H. Wang, V. Kainulainen, M.L. Fitzgerald, S. Ledbetter, D.M. Ornitz, and M. Bernfield. 1998. Nat. Med. 4:691–697) and proteolytic balance (Kainulainen, V., H. Wang, C. Schick, and M. Bernfield. 1998. J. Biol. Chem. 273:11563–11569). However, little is known about how syndecan ectodomain shedding is regulated. To elucidate the mechanisms that regulate syndecan shedding, we analyzed several features of the process that sheds the syndecan-1 and -4 ectodomains. We find that shedding accelerated by various physiologic agents involves activation of distinct intracellular signaling pathways; and the proteolytic activity responsible for cleavage of syndecan core proteins, which is associated with the cell surface, can act on unstimulated adjacent cells, and is specifically inhibited by TIMP-3, a matrix-associated metalloproteinase inhibitor. In addition, we find that the syndecan-1 core protein is cleaved on the cell surface at a juxtamembrane site; and the proteolytic activity responsible for accelerated shedding differs from that involved in constitutive shedding of the syndecan ectodomains. These results demonstrate the existence of highly regulated mechanisms that can rapidly convert syndecans from cell surface receptors or coreceptors to soluble heparan sulfate proteoglycan effectors. Because the shed ectodomains are found and function in vivo, regulation of syndecan ectodomain shedding by physiological mediators indicates that shedding is a response to specific developmental and pathophysiological cues.

Journal ArticleDOI
TL;DR: In this article, the authors provide a review of the nature and variability of the climate and hydrology in the source region of the Blue Nile-the central Ethiopian Highlands, and provide a time series of annual rainfall constructed from 11 gauges for the period 1900 to 1998.
Abstract: The Upper Blue Nile river basin is the largest in Ethiopia in terms of volume of discharge, second largest in terms of area, and contributes over 50 per cent of the long-term river flow of the Main Nile. This paper provides a review of the nature and variability of the climate and hydrology in the source region of the Blue Nile-the central Ethiopian Highlands. Annual rainfall over the basin decreases from the south-west (>2000 mm) to the north-east (around 1000 mm), with about 70 per cent occurring between June and September. A basin-wide time series of annual rainfall constructed from 11 gauges for the period 1900 to 1998 has a mean of 1421millimetres, minimum in 1913 (1148 mm) and maximum in 1903 (1757 mm). Rainfall over the basin showed a marked decrease between the mid-1960s and the late 1980s and dry years show a degree of association with low values of the Southern Oscillation Index (Sol). The October to February dry season in 1997/98 was the wettest on record and responsible for widespread flooding across Ethiopia and also parts of Somalia and Kenya. Available river flow records, which are sparse and of limited duration, are presented for the Blue Nile and its tributaries upstream of the border with Sudan. Runoff over the basin amounts to 45.9 cubic kilometres (equivalent to 1456 m3s−1) discharge, or 261 millimetre depth (1961–1990), a runoff ratio of 18 per cent. Between 1900 and 1997 annual river flow has ranged from 20.6 cubic kilometres (1913) to 79.0 cubic kilometres (1909), and the lowest decade-mean flow was 37.9 cubic kilometres from 1978 to 1987. Annual river flow, like rainfall, shows a strong association with the SOI

Journal ArticleDOI
TL;DR: This work has proposed a new approach to relate large collective motions to functional properties, such as binding and regulation, or to folding, which has been recently addressed in several papers.

Journal ArticleDOI
TL;DR: In this article, the use of an aqueous-based extraction technique utilizing hydroxypropyl-β-cyclodextrin (HPCD) is presented for the extraction of PAHs from soil.
Abstract: Traditionally, soil extraction techniques have been concerned with the determination of “total” organic contaminant concentrations, following an “exhaustive” extraction. However, in light of the increasing body of knowledge relating to organic contaminant availability and aging, such methods have little relevance to the amount of contaminant that may pose an ecological risk i.e., the “bioavailable” portion. Less exhaustive techniques have therefore been the subject of more recent approaches in the hope that they may access the “labile” or bioavailable pool. The use of an aqueous-based extraction technique utilizing hydroxypropyl-β-cyclodextrin (HPCD) is presented here for the extraction of PAHs from soil. The optimization of the method is described in terms of HPCD concentration, extraction time, and solution buffering. The procedure is then tested and validated for a range of 14C-labeled PAHs (phenanthrene, pyrene, and benzo[a]pyrene) added at a range of concentrations to a range of soil types. The amoun...

MonographDOI
04 Sep 2000
TL;DR: In this paper, the authors provide a challenging explanation of the forces that have shaped the international global warming debate, focusing on the ways non-state actors such as scientific, environmental and industry groups, as opposed to governmental organizations, affect political outcomes in global fora on climate change.
Abstract: This volume provides a challenging explanation of the forces that have shaped the international global warming debate. It takes a novel approach to the subject by concentrating on the ways non-state actors--such as scientific, environmental and industry groups, as opposed to governmental organizations--affect political outcomes in global fora on climate change. It also provides insights into the role of the media in influencing the agenda. The book draws on a range of analytical approaches to assess and explain the influence of these nongovernmental organizations on the course of global climate politics. The book will be of interest to all researchers and policy makers associated with climate change, and will be used in university courses in international relations, politics, and environmental studies.

Journal ArticleDOI
TL;DR: The economic impact of RA in terms of cost was reported to be substantial by all studies reviewed, however, methodological problems meant that discrepancies in the average (per person) annual cost of RA existed across studies.
Abstract: Objective. To summarize the state of knowledge with regard to the economic impact of rheumatoid arthritis (RA) and to highlight any weaknesses in the work conducted to date, so as to inform future RA cost-of-illness studies. Methods. Four computerized literature databases were searched to identify all the literature relevant to this review. Seven elements indicating a quality cost-of-illness study were established and used to appraise the literature identified critically. Where possible, costs reported by the diVerent studies were converted to 1996 US dollars using the consumer price index for medical care. Results. Total average medical costs were reported to range from US$5720 ( UK£3575) to US$5822 ( UK£3638). Medication constituted between 8 and 24% of total medical costs, physician visits between 8 and 21%, and in-patient stays between 17 and 88%. The average number of days absent from work due to a person’s RA was reported to range from 2.7 to 30 days/year. Conclusion. The economic impact of RA in terms of cost was reported to be substantial by all studies reviewed. However, methodological problems meant that discrepancies in the average (per person) annual cost of RA existed across studies.

Journal ArticleDOI
TL;DR: The results support a role for hypoxia in the pathogenesis of fibrosis and provide evidence for novel, direct hypoxic effects on the expression of genes involved in fibrogenesis.