Showing papers by "University of East Anglia published in 1997"
TL;DR: Early instrumental pressure measurements from Gibraltar and the Reykjavik area of Iceland have been used to extend to 1821 the homogeneous pressure series at the two locations In winter the two sites are located close to the centres of action that comprise the North Atlantic Oscillation (NAO) as mentioned in this paper.
Abstract: Early instrumental pressure measurements from Gibraltar and the Reykjavik area of Iceland have been used to extend to 1821 the homogeneous pressure series at the two locations In winter the two sites are located close to the centres of action that comprise the North Atlantic Oscillation (NAO). The extended 'winter half-year' record of the NAO enables recent changes in the record to be placed in the context of the period 1823-1996 The period since the early 1970s is the most prolonged positive phase of the oscillation and the late 1980s and early 1990s is the period with the highest values (strongest westerlies) The winter of 1995-1996 marked a dramatic switch in the index, with the change from 1994-1995 being the greatest change recorded from one year to the next since the series began in 1923. (The extended Gibraltar and Reykjavik monthly pressures and the NAO series can be found on the Climatic Research Unit home page. www.cru.uea-ac.uk.
1,717 citations
TL;DR: In this article, the authors used a local stochastic weather generator to simulate site-specific daily weather data and used regression downscaling to translate the coarse resolution GCM grid-box predictions of climate change to site specific values.
Abstract: Climate change scenarios with a high spatial and temporal resolution are required in the evaluation of the effects of climate change on agricultural potential and agricultural risk. Such scenarios should reproduce changes in mean weather characteristics as well as incorporate the changes in climate variability indicated by the global climate model (GCM) used. Recent work on the sensitivity of crop models and climatic extremes has clearly demonstrated that changes in variability can have more profound effects on crop yield and on the probability of extreme weather events than simple changes in the mean values. The construction of climate change scenarios based on spatial regression downscaling and on the use of a local stochastic weather generator is described. Regression downscaling translated the coarse resolution GCM grid-box predictions of climate change to site-specific values. These values were then used to perturb the parameters of the stochastic weather generator in order to simulate site-specific daily weather data. This approach permits the incorporation of changes in the mean and variability of climate in a consistent and computationally inexpensive way. The stochastic weather generator used in this study, LARS-WG, has been validated across Europe and has been shown to perform well in the simulation of different weather statistics, including those climatic extremes relevant to agriculture. The importance of downscaling and the incorporation of climate variability are demonstrated at two European sites where climate change scenarios were constructed using the UK Met. Office high resolution GCM equilibrium and transient experiments.
770 citations
TL;DR: Insect mitochondrial control regions are not necessarily the most variable region in the genome in terms of nucleotide substitution, and may not evolve faster than single-copy nuclear non-coding sequences.
557 citations
TL;DR: In this article, eight alternative methods of eliciting preferences between money and a consumption good are identified: two of these are standard willingness-to-accept and willingness to pay measures, and the others differ with respect to the reference point used and the dimension in which responses are expressed.
Abstract: Eight alternative methods of eliciting preferences between money and a consumption good are identified: two of these are standard willingness-to-accept and willingness-to-pay measures. These methods differ with respect to the reference point used and the dimension in which responses are expressed. The loss aversion hypothesis of Tversky and Kahneman's theory of reference-dependent preferences predicts systematic differences between the preferences elicited by these methods. These predictions are tested by eliciting individuals' preferences for two private consumption goods; the experimental design is incentive-compatible and controls for income and substitution effects. The theory's predictions are broadly confirmed.
431 citations
TL;DR: In this article, the authors analyzed evaporation time series data for different stations in India, and for the country as a whole, for different seasons on both a short-term (15 years) and longterm (32 years) basis for pan-evaporation and on a shortterm basis alone for potential evapotranspiration.
419 citations
TL;DR: A single 5 mg/kg infusion of CDP571 reduced disease activity in Crohn's disease at 2 weeks, suggesting that antibody neutralisation of TNFα is a potentially effective strategy in the management of Crohn't disease.
393 citations
TL;DR: It is concluded that predator removal often fulfills the goal of game management, but that it is much less consistent in achieving the usual aim of conservation managers, which is to maintain and, where appropriate, increase bird breeding population sizes.
Abstract: The control of predators for nature conservation purposes is becoming an increasingly important issue. The growing populations of predator species in some areas and the introduction of predators in other areas have led to concerns about their impact on vulnerable bird species and to the implementation of preda- tor control in some cases. This is set against a background of increasingly fragmented semi-natural habitats and declining populations for many species. To assess the efficiency of predator removal as a conservation measure, the results of 20 published studies of predator removal programs were meta-analyzed. Removing predators had a large, positive effect on hatching success of the target bird species, with removal areas show- ing higher hatching success, on average, than 75% of the control areas. Similarly, predator removal increased significantly post-breeding population sizes (i.e. autumn densities) of the target bird species. The effect ofpred- ator removal on breeding population sizes was not significant, however, with studies differing widely in their reported effects. We conclude that predator removal often fulfills the goal of game management, which is to enhance harvestable post-breeding populations, but that it is much less consistent in achieving the usual aim of conservation managers, which is to maintain and, where appropriate, increase bird breeding population sizes. This may be due to inherent characteristics of avian population regulation, but also to ineffective pred- ator removal and inadequate subsequent monitoring of the prey populations.
336 citations
TL;DR: In this article, a method is developed for estimating the uncertainty (standard error) of observed regional, hemispheric, and global-mean surface temperature series due to incomplete spatial sampling.
Abstract: A method is developed for estimating the uncertainty (standard error) of observed regional, hemispheric, and global-mean surface temperature series due to incomplete spatial sampling. Standard errors estimated at the grid-box level [SE2 5 S2(1 2 r)/(1 1 (n 2 1)r)] depend upon three parameters: the number of site records (n) within each box, the average interrecord correlation (r) between these sites, and the temporal variability (S2 )o f each grid-box temperature time series. For boxes without data (n 5 0), estimates are made using values of S2 interpolated from neighboring grid boxes. Due to spatial correlation, large-scale standard errors in a regionalmean time series are not simply the average of the grid-box standard errors, but depend upon the effective number of independent sites (Neff) over the region. A number of assumptions must be made in estimating the various parameters, and these are tested with observational data and complementary results from multicentury control integrations of three coupled general circulation models (GCMs). The globally complete GCMs enable some assumptions to be tested in a situation where there are no missing data; comparison of parameters computed from the observed and model datasets are also useful for assessing the performance of GCMs. As most of the parameters are timescale dependent, the resulting errors are likewise timescale dependent and must be calculated for each timescale of interest. The length of the observed record enables uncertainties to be estimated on the interannual and interdecadal timescales, with the longer GCM runs providing inferences about longer timescales. For mean annual observed data on the interannual timescale, the 95% confidence interval for estimates of the global-mean surface temperature since 1951 is 60.128C. Prior to 1900, the confidence interval widens to 60.188C. Equivalent values on the decadal timescale are smaller: 60.108C (1951‐95) and 60.168C (1851‐1900).
325 citations
TL;DR: The structure of the individual domains of a number of matrix metalloproteinases have now been elucidated, and in particular the C-terminal hemopexin-like domain is focused on which has intriguingly specific roles in individual matrix meetallop Proteinases.
306 citations
TL;DR: In this article, the role of trust in facilitating efficient exchange relations when agents are vulnerable to opportunistic behaviour is analyzed, and two distinct mechanisms supporting trust are distinguished: self-interested trust, which is forwardlooking, and socially-oriented trust, SOT, which has its roots in the past.
Abstract: This paper analyses the role of trust in facilitating efficient exchange relations when agents are vulnerable to opportunistic behaviour. Two distinct mechanisms supporting trust are distinguished: self-interested trust, SIT, which is forwardlooking, and socially-oriented trust, SOT, which has its roots in the past. The former is the only source of trust recognised in the mainstream economics literature, while the latter draws heavily from sociology. We develop the implications of isolated and of repeated exchange for the existence of SIT or SIT, and for the role of formal contracts in exchange relations. The paper concludes with a discussion of the feasibility of empirical testing to distinguish SIT from SOT.
303 citations
Harvard University1, University of California, Irvine2, National Center for Atmospheric Research3, York University4, Lawrence Livermore National Laboratory5, Langley Research Center6, University of Washington7, University of Cambridge8, Max Planck Society9, Centre national de la recherche scientifique10, Georgia Institute of Technology11, German Aerospace Center12, University at Albany, SUNY13, University of East Anglia14, Royal Netherlands Meteorological Institute15
TL;DR: In this article, simulations of 222Rn and other short-lived tracers are used to evaluate and intercompare the representations of convective and synoptic processes in 20 global atmospheric transport models.
Abstract: Simulations of 222Rn and other short-lived tracers are used to evaluate and intercompare the representations of convective and synoptic processes in 20 global atmospheric transport models. Results show that most established three-dimensional models simulate vertical mixing in the troposphere to within the constraints offered by the observed mean 222Rn concentrations and that subgrid parameterization of convection is essential for this purpose. However, none of the models captures the observed variability of 222Rn concentrations in the upper troposphere, and none reproduces the high 222Rn concentrations measured at 200 hPa over Hawaii. The established three-dimensional models reproduce the frequency and magnitude of high-222Rn episodes observed at Crozet Island in the Indian Ocean, demonstrating that they can resolve the synoptic-scale transport of continental plumes with no significant numerical diffusion. Large differences between models are found in the rates of meridional transport in the upper troposphere (interhemispheric exchange, exchange between tropics and high latitudes). The four two-dimensional models which participated in the intercomparison tend to underestimate the rate of vertical transport from the lower to the upper troposphere but show concentrations of 222Rn in the lower troposphere that are comparable to the zonal mean values in the three-dimensional models.
TL;DR: It is proposed that Hyf, in conjunction with formate dehydrogenase H (Fdh-H), forms a hitherto unrecognized respiration-linked proton-translocating formate hydrogenlyase (FHL-2) that is likely to act as a formate-dependent regulator of the hyf operon and that FocB provides the Hyf complex with external formate as substrate.
Abstract: The nucleotide sequence has been determined for a twelve-gene operon of Escherichia coli designated the hyf operon (hyfABCDEFGHIR-focB). The hyf operon is located at 55.8-56.0 min and encodes a putative nine-subunit hydrogenase complex (hydrogenase four or Hyf), a potential formate- and σ54dependent transcriptional activator, HyfR (related to FhlA), and a possible formate transporter, FocB (related to FocA). Five of the nine Hyf-complex subunits are related to subunits of both the E. coli hydrogenase-3 complex (Hyc) and the proton-translocating NADH:quinone oxidoreductases (complex I and Nuo), whereas two Hyf subunits are related solely to NADH:quinone oxidoreductase subunits. The Hyf components include a predicted 523 residue [Ni-Fe] hydrogenase (large subunit) with an N-terminus (residues 1-170) homologous to the 30 kDa or NuoC subunit of complex I. It is proposed that Hyf, in conjunction with formate dehydrogenase H (Fdh-H), forms a hitherto unrecognized respiration-linked proton-translocating formate hydrogenlyase (FHL-2). It is likely that HyfR acts as a formate-dependent regulator of the hyf operon and that FocB provides the Hyf complex with external formate as substrate.
TL;DR: In this article, the role of equity in the aggregation of climate change damage estimates, using basic tools of welfare economics, is analyzed, and it is shown that while the postulate of uniform per-unit values is compatible with a wide range of'reasonable' utility and welfare specifications, there are also cases where the common value notion is not compatible with defensible welfare concepts.
Abstract: The economic value of environmental goods is commonly determined using the concepts of willingness to pay (WTP) or willingness to accept (WTA). However, the WTP/WTA observed in different countries (or between individuals) will differ according to socio-economic characteristics, in particular income. This notion of differentiated values for otherwise identical goods (say, a given reduction in mortality risk) has been criticized as unethical, most recently in the context of the 'social cost' chapter of the IPCC Second Assessment Report. These critics argue that, being a function of income, WTP/WTA estimates reflect the unfairness in the current income distribution, and for equity reasons uniform per-unit values should therefore be applied across individuals and countries. This paper analyses the role of equity in the aggregation of climate change damage estimates, using basic tools of welfare economics. It shows one way of how WTP/WTA estimates can be corrected in aggregation if the underlying income distribution is considered unfair. It proposes that in the aggregation process individual estimates be weighted with an equity factor derived from the social welfare and utility functions. Equity weighting can significantly increase aggregate (global) damage figures, although some specifications of weighting functions also imply reduced estimates. The paper also shows that while the postulate of uniform per-unit values is compatible with a wide range of 'reasonable' utility and welfare specifications, there are also cases where the common-value notion is not compatible with defensible welfare concepts.
TL;DR: In this paper, the authors focus on why we believe the things that we do and how we justify the claims we make, what they call "warranted assertibility" (WEE), which refers to the reasons we have for believing truth claims.
Abstract: At its most rudimentary, validity refers to the reasons we have for believing truth claims, what Dewey called “warranted assertibility” (Phillips, 1987). These truth claims may take the form of statements of fact, descriptions, accounts, propositions, generalisations, inferences, interpretations, judgements or arguments. Irrespective of their form what is important is why we believe the things that we do and how we justify the claims we make.
TL;DR: Data from a large British survey are combined with a review of the extensive body of qualitative research on attitudes to health in Western industrialised societies to reach a tentative conclusion that social inequality in health is not a topic which is very prominent in lay presentations.
TL;DR: In this paper, the authors reported the presence of mid-estuarine barium concentration maxima in six estuarine systems in the U.S.A. and Europe and rationalized these differences in terms of low-salinity desorption of particulate barium, estuarial particle dynamics, riverine sediment supply and barium storage and subsequent slow release in salt marshes.
Abstract: Estuarine profiles of dissolved barium are reported from six estuarine systems in the U.S.A. and Europe. All show clear evidence of mid-estuarine barium concentration maxima, although the location and scale of these maxima vary. These differences are rationalized in terms of low-salinity desorption of particulate barium, estuarine particle dynamics, riverine sediment supply and barium storage and subsequent slow release in salt marshes. Low-salinity removal of barium also occurs in some estuaries, apparently related to dissolved iron and manganese removal.
TL;DR: In this paper, the authors present data from a standardized series of line-transect censuses on the species and subspecies composition, population density, and crude biomass of western Amazonian primate communities occurring at eight flooded (varzea) and 12 unflooded (terra firme) for- ests.
Abstract: This paper presents data from a standardized series of line-transect censuses on the species and subspecies composition, population density, and crude biomass of western Amazonian primate communities occurring at eight flooded (=varzea) and 12 unflooded (= terra firme) for- ests. These were located primarily along one of the largest white-water tributaries of the Amazon (= Solim6es), the Jurua river. On average, terra firme forests contained twice as many primate species, lower population densities, and less than half of the total community biomass than did adjacent vairzea forests. There was a clear habitat-dependent positive association among primate species, particularly within vairzea forests, as well as marked shifts in guild structure between forest types. Species turnover between these two forest types involved primarily understorey insectivores (e.g. Saguinus sp.), which do not occur in seasonally inundated forest. These were consistently replaced by squirrel monkeys (Saimiri sp.), which are extremely abundant in annually flooded vairzea forests. Similarly, large-bodied folivores such as red howler monkeys (Alouatta seniculus) were uncommon or rar-e in terra firme forests, but veiy abundant in varzea forests, even though they are hunted less intensively in the former than in the latter. This can be largely explained by the nutrient-rich alluvial soils of young floodplains, compared to the heavily weathered terra firme soils occurring even within short distances of major white-water rivers. This study clearly shows a reversed diversity/density patterni resulting from the lower species richness, but high overall community biomass of seasonally flooded Amazonian forests, which can now be generalized for a wide range of terrestrial vertebrate taxa, including amphibians, birds, and sev- eral other orders of mammals.
TL;DR: Results from a study examining non-users' values for preserving the Norfolk Broads, a wetland area of recognized international importance, from the threat of saline flooding are presented.
Abstract: BATEMAN I. J. and LANGFORD I. H. (1997) Non-users' willingness to pay for a National Park: an application and critique of the contingent valuation method, Reg. Studies 31, 571‐582. A great deal of the ongoing academic debate concerning the contingent valuation (CV) method has focused upon whether or not the method is suitable for assessing non-use values. This paper presents results from a study examining non-users' values for preserving the Norfolk Broads, a wetland area of recognized international importance, from the threat of saline flooding. Discussion of results centres upon the validity of the CV method for eliciting unbiased estimates of non-use value. A graphical representation of findings from a variety of studies is presented to suggest that such results are logically ordered across goods and valuation scenarios. However, as the paper concludes, logicality and validity are not necessarily synonymous. BATEMAN I. J. et LANGFORD I. H. (1997) La volonte des non-usagers de payer les parcs nationaux:...
TL;DR: In this paper, the authors argue that if homeworking becomes more common, there are dangers and benefits both for the organizations and the individuals involved, and they propose to make it more common.
Abstract: If homeworking becomes more common, there are dangers and benefits both for the organizations and the individuals involved.
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TL;DR: In this article, the authors present new experimental results which directly address the issue of the realness of such data and its reliability as a basis for criticizing Expected Utility Theory and promoting alternative theories.
Abstract: Much of the evidence raising doubts about Expected Utility Theory (EUT) comes from experiments involving hypothetical decisions. Most of the rest of the evidence comes from experiments where respondents are asked to make a large number of decisions, knowing that only one of these will provide the basis for payment. Concerns have often been expressed about the 'realness' of such data, and its reliability as a basis for criticizing EUT and promoting alternative theories. The present paper reviews this debate and reports new experimental results which directly address this issue.
TL;DR: Stable carbon and oxygen isotope data from over 80 samples of Recent freshwater microbial carbonates from western Europe, confirm that these deposits record environmental and climatic information as discussed by the authors, particularly in the Alps where δw is influenced by lower condensation temperatures caused by the orographic effect.
TL;DR: In this paper, the seasonally averaged flux of isoprene to the atmosphere was estimated to be 1.7 × 107 molecules cm−2 s−1, which may be significant for atmospheric chemistry in locations remote from land as it is the only known source of atmospheric isoperesidual in these regions.
Abstract: In this paper we show evidence that isoprene emission from the oceans is strongly seasonally dependent and is correlated with the chlorophyll content of the water from measurements in the North Sea and Southern Ocean. We estimate the seasonally averaged flux of isoprene to the atmosphere to be 1.7 × 107 molecules cm−2 s−1, which may be significant for atmospheric chemistry in locations remote from land as it is the only known source of atmospheric isoprene in these regions. We observe a strong seasonal cycle of several other NMHCs in seawater at high latitudes, with a maximum in summer. This will distort current estimates of the annual marine flux of NMHCs to the atmosphere which may need to be reduced by up to an order of magnitude to account for lower emissions in winter.
TL;DR: In this article, the authors report on an experiment into part-whole bias in restaurant meal valuations, and show that the sum of the valuations of the parts consistently exceeded that of the whole in a context where traditional explanations would not have predicted it.
Abstract: The existence of part–whole bias has been hotly disputed in the recent contingent valuation literature. This paper reports on an experiment into part–whole bias. Employing vouchers for parts of a restaurant meal and using an incentive compatible procedure, valuations of the parts and of the whole were elicited. The sum of the valuations of the parts consistently exceeded that of the whole, providing evidence of the existence of part–whole bias in a context where traditional explanations would not have predicted it.
TL;DR: In this article, a method for estimating the standard deviation and rainday frequency of grid-box mean daily precipitation time series from relatively few individual station time series is presented. But the method is limited in the number of stations used to construct the areal means and is shown to be biased if insufficient stations are available.
Abstract: The validation of climate model simulations creates substantial demands for comprehensive observed climate datasets. These datasets need not only to be historically and geographically extensive, but need also to be describing areally averaged climate, akin to that generated by climate models. This paper addresses one particular difficulty found when attempting to evaluate the daily precipitation characteristics of a global climate model, namely the problem of aggregating daily precipitation characteristics from station to area. Methodologies are developed for estimating the standard deviation and rainday frequency of grid-box mean daily precipitation time series from relatively few individual station time series. Temporal statistics of such areal-mean time series depend on the number of stations used to construct the areal means and are shown to be biased (standard deviations too high, too few raindays) if insufficient stations are available. It is shown that these biases can be largely removed b...
TL;DR: Although there has been an overall trend toward the evolution of live–bearing in elesmobranchs, the evolutionof additional maternal input has been extremely labile.
Abstract: Sharks and rays are thought to have a large number of independent origins of live–bearing. We examined evolutionary transitions to live–bearing and maternal input to embryos in this subclass by optimizing reproductive characters onto a composite phylogeny. Egg–laying (40 % of all species) is the likely ancestral reproductive mode for this clade, and there is evidence that live–bearing has evolved independently 9–10 times and maternal input 4–5 times. Most transitions (12–15) have been toward live–bearing with provisioning limited to yolk. These have occurred from egg–laying ancestors or live–bearing taxa that provide maternal input to embryos. Only 2–3 transitions have occurred in the other direction, i.e. away from yolk–only bearing. Egg–laying has evolved from live–bearing ancestors in skates, Rajidae (25 per cent of all species) and possibly in the zebra shark, Stegostoma fasciata . Thus, although there has been an overall trend toward the evolution of live–bearing in elesmobranchs, the evolution of additional maternal input has been extremely labile.
TL;DR: A set of mitochondrial COI primers has been studied by genomic PCR and many primer combinations shown to work universally well across Insects, and general problems in the use of conserved PCR primers are discussed.
Abstract: A set of mitochondrial COI primers has been studied by genomic PCR and many primer combinations shown to work universally well across Insecta. They are able to amplify various amplicons with different variability which enables the selection of a particular amplicon as a suitable DNA marker for a project. The potential usefulness of different amplicons is examined, with analysis on published study cases employing these regions. With respect to their variability, amplicons UEA5/UEA6, UEA7/UEA8 and UEA5/UEA8 could be useful for low- to mid-level phylogenetic analysis, i.e. from species, genus to perhaps family level depending on taxa involved. UEA5/UEA6 will be too conserved for intraspecific studies. Amplicons UEA3/UEA4 and UEA9/UEA10 would be better suited to low-level phylogenetic investigations, such a analysis of relationships among closely related species and population genetic studies. However, these guidelines should not be over-generalized for the reasons given. Amplification conditions of various primer combinations, and general problems in the use of conserved PCR primers are discussed.
TL;DR: This study presents data on the population density, spatial distribution, and seed dispersal ecology of Brazilnut trees at a pristine stand located within the Kayap6 Indian Area of southeastern Amazonia, Para, Brazil and suggests that, once edaphic and climatic conditions are suitable, the highly contagious spatial distiibution of Bertholletia trees at the landscape level can be largely affected by the quantitatively domiinant effect of short-distance dispersal by caviomorph rodents
Abstract: Seeds of the Brazilnut tIee (Bertholletia excelsa Humb. & Bonpl., Lecythidaceae) sus- tain one of the imiost important extractive industries in neotropical foiests. Yet little is known about the demogiaphy aind seed dispersal ecology of Bertholletia, particularly in natural stands which have inot been prevriously hai-rested. This study presents data on the population density, spatial distribution, aind seed dispersal ecology of Brazilnut trees at a pristine stand located within the Kayap6 Indian Area of southeastern Amazonia, Para, Brazil. Brazilnut trees were primarily found within groves (castaizhais) of 75 to 149 trees, with a few isolated trees in between. Although the density of trees 10 cm in diameter at breast height (hereafter, dbh) at two groves was 4.8 to 5.1 trees ha-', the overall deinsity for the entire study area of c. 950 ha was estimated at 1.3 tree ha-'. Within-gi-ove neaiest ineighbour distances averaged 21 m and weie markedly skewed towaids even shorter distances. Seed dispersal experiments uising 709 maikedl seeds indlicated that this pattern can be largely explained by the highly restricted seed shadows imparted by the main seed dispersal agents of Bertholletia at this site, the red-rumped agouti (Dasyprocta leporina). Agoutis on average scatterhoard Bertholletia seeds to an average distaince of 5 m, and rarely beyond 20 m, from seed stations. We suggest that, once edaphic and climatic conditions aie suitable, the highly contagious spatial distiibution of Ber-tholletia trees at the landscape level can be largely accouinted foi by the quantitatively domiinant effect of short-distance dispersal by caviomorph rodents, and rare events of long-distance dispersal provided by other vectors. This mechanism of grove forma- tion need not resort to untested conjectures of human dispersal and intentional planting in prehis- toric and historic times as it has often been suggested in the literature.
TL;DR: In this paper, a hemispheric-wide attempt to model iceberg motion in the Arctic and North Atlantic Oceans is presented, where the basic force balance in iceberg motion is between water drag and water advection, but with the pure geostrophic balance being only a minor component of the latter.
TL;DR: This minireview focuses mainly on more recent discoveries concerning the biosynthesis and turnover of DMSP, DMS, and related compounds in the biosphere and with respect to the role of DMS in the global sulfur cycle and climate.
Abstract: It has long been recognized that algae play a highly significant role in the global biogeochemical cycles of oxygen, carbon, nitrogen, phosphorus, and sulfw. The key chemical compounds driving these cycles are often low molecular weight and/or volatile species. In the case of sulfur, a dominant compound is dimethyl sulfide (DMS), which derives from dimethylsulfoniopropionate (DMSP) , an organic osmolyte that acts as a compatible solute in algal cells. High concentrations of DMS and DMSP can be found in areas of high algal productivity, such as marine phytoplankton blooms. In recent years research has unveiled greater detail concerning the biosynthesis and turnover of DMSP, DMS, and related compounds in the biosphere and with respect to the role of DMS in the global sulfur cycle and climate. In this minireview our aim is to concentrate mainly on these more recent discoveries.
TL;DR: In this paper, the authors developed and validated a water balance model of the Upper Blue Nile in Ethiopia using a grid-based model which requires limited data inputs, few parameters and runs on a monthly time-step.
Abstract: This paper describes the development and validation of a water balance model of the Upper Blue Nile in Ethiopia. A major requirement of any modelling attempt is the availability of climatic and hydrological data. However, for the Upper Blue Nile, only a limited number of observation sites are available over a very large area. As a result, the model described here is a grid-based water balance model which requires limited data inputs, few parameters and runs on a monthly time-step. Climate is dominated by the influence of elevation in the river basin. Estimates of potential evapotranspiration (PE) and rainfall are predicted for 10-minute resolution grid cells for input to the model. These estimates are based on multiple regression models using latitude, longitude and elevation. In the basin, annual mean PE and rainfall range, with increasing elevation, from 1800 mm to 1200 mm and 924 mm to 1845 mm, respectively. In the model, vegetation cover is not explicitly treated and soil characteristics are ...