Physical and Epitope Analysis of a Recombinant Human T-Cell Receptor Vα/Vβ Construct Support the Similarity to Immunoglobulin

The genetic organization and protein structure of T-cell receptors (TCR) and immunoglobulins (Ig) are remarkably similar. Through recombinant, physical, and peptide-based immunological studies we demonstrated that rabbit antisera generated against a recombinant single-chain TCR (scTCR) react with defined peptide epitopes of their constituent TCR and chains. These antisera cross-react with the light-chain Mcg as well as with peptides duplicating its covalent structure. Conversely, rabbit antisera generated to human light chains cross-reacted with the recombinant scTCR. Rabbit anti- antibodies purified on an scTCR affinity column bound to T-cell lines and to T and B lymphocytes from peripheral blood. Circular dichroism analysis demonstrated plots characteristic of -sheets for both Mcg and recombinant scTCR. Antisera directed against TCR -chain synthetic peptides reacted with scTCR, Mcg light-chain protein, synthetic peptides from regions of sequence homology in -chains, and Mcg. Based upon this homology and the serological cross-reactions which reflect conformational determinants, we suggest that the V/V antigen-binding domain of this particular monoclonal scTCR construct is substantially similar to the conformational structure of light chains.     

Methane distribution in European tidal estuaries

Methane concentrations have been measured along salinity profilesin nine tidal estuaries in Europe (Elbe, Ems, Thames, Rhine,Scheldt, Loire, Gironde, Douro and Sado). The Rhine, Scheldt andGironde estuaries have been studied seasonally. A number ofdifferent methodologies have been used and they yieldedconsistent results. Surface water concentrations ranged from0.002 to 3.6 M, corresponding to saturation ratios of 0.7 to1580 with a median of 25. Methane concentrations in thefresh-water end-members varied from 0.01 to 1.4 M. Methaneconcentrations in the marine end-members were close to saturationoffshore and on the order of 0.1 M in estuarine plumes. Methaneversus salinity profiles in river-dominated, stratified estuaries(Rhine and Douro) appeared rather erratic whereas those in thewell mixed, long-residence time estuaries (Elbe, Ems, Thames,Scheldt, Loire, Gironde and Sado) revealed consistent trends. Inthese systems dissolved methane initially decreases withincreasing salinity, then increases to a maximum at intermediateto high salinities before decreasing again going offshore. Tidalflats and creeks were identified as a methane source to estuarinewaters. The global estuarine flux of methane to the atmospherehas been calculated by combining the median water-air methanegradient (68.2 nmol dm^–3) with a global area weighted transfercoefficient and the global area of estuaries. Estuaries emit 1.1to 3.0 Tg CH₄ yr^–1, which is less than 9% of the global marinemethane emission.     

High-affinity binding of fungal β-glucan elicitors to cell membranes of species of the plant family Fabaceae

Microsomal preparations of six species of the plant family Fabaceae were screened for high-affinity binding of branched (1 3), (1 6)--glucans. Oligoglucosides of this type are specific elicitors of phytoalexin accumulation in soybean (Glycine max L.), a member of this family. The species studied were alfalfa (Medicago sativa L.), broadbean (Vicia faba L.), chickpea (Cicer arietinum L.), french bean (Phaseolus vulgaris L.), pea (Pisum sativum L.), and white lupin (Lupinus albus L.). A ¹²⁵I-labeled 4-(2-aminophenyl)ethylamine conjugate of a (1 3), (1 6)--glucan fraction with an average degree of polymerization (DP) of 18, obtained from mycelial walls of Phytophthora sojae, was used as radioligand for initial screening. The structural complexity of this fraction allowed the identification of binding sites with affinities for isomeric structures other than the (1 3), (1 6) hepta--glucoside for which soybean binding sites display highest affinity. Radioligand competition experiments against unlabeled fungal -glucan resulted in the identification of high-affinity binding in alfalfa, bean, lupin, and pea. Half-maximal competition concentrations (IC₅₀) for fungal -glucan in these species were between 5 and 30 nM. Pseudoheterologous radioligand competition by unlabeled hepta--glucoside showed that for alfalfa, lupin and pea the IC₅₀ values for this structure (4 to 16 nM) were similar to those of soybean (7.7 nM). Bean microsomes, however, displayed an IC₅₀ significantly higher than soybean (68 nM) suggesting that the structural motif recognized by its binding sites is not identical to that of soybean or the other three species. Radioligand saturation assays with alfalfa, lupin and pea microsomes using an ₁₂₅I-labeled aminophenylethylamine hepta--glucoside conjugate gave dissociation constants (K_d) of 5.3, 3.7, and 1.8 nM, respectively. The affinity of these sites for hepta- glucoside was in the same range as that of soybean (K_d 1–3 nM), whereas the affinity of the binding sites of bean for the same ligand was significantly lower (K_d = 33 nM). Good correlation was found between the presence of high-affinity binding and the accumulation of isoflavonoid phytoalexins in roots of alfalfa, bean, chickpea and pea seedlings after exposure to fungal -glucan. Lupin displayed a strong wound-induced accumulation of prenylated isoflavones which was independent of the presence of -glucan, making it impossible to determine phytoalexin induction in response to elicitor. No specific binding or phytoalexin accumulation in response to glucans was observed in broadbean. This is the first report on the existence of possibly homologous elicitor-binding sites within a plant taxonomic family and may provide preliminary evidence for putative evolutionary relationships in pathogen perception mechanisms in plants.Abbreviations DP degree of polymerization - EC₅₀ concentration of elicitor necessary to obtain a half-maximal biological response - HG synthetic (1 3), (1 6)-hepta--glucoside phytoalexin elicitor - HG-APEA 1-[4-(2-aminophenyl)ethylamino-1-hexaglucosyl]deoxyglucitol - IC₅₀ ligand concentration necessary to obtain half-maximal displacement of radioligand in competition binding assays - K_d dissociation constant - OS branched (1 3), (1 6)--glucan obtained by hydrolysis of mycelial walls of Phytophthora sojae - OS-APEA 1-[4-(2-armnophenyl)ethylamino-1-oligoglucosyl]deoxyglucitol conjugate of OS This work was supported by the Comision Interministerial de Ciencia y Tecnologia grant BI091-0366 (E.G.C.), the Volkswagen-Stiftung (E.G.C. and J.E.), the Deutsche Forschungsgemeinschaft, SFB-369 (J.E.), the Bundesministerium fiir Bildung, Wissenschaft, Forschung und Technologie (J.E.), Fonds der Chemischen Industrie (J.E.) and the EU Human Capital and Mobility Program (J.E. and E.G.C.).     

Enteromorpha as a monitor of heavy metals in estuaries

An account is given of the use of Enteromorpha to monitor zinc, cadmium, mercury and lead pollution in six estuaries and the British North Sea coast. The ranges for each element were: Zn, 19–437 µg g^–1; µg g^–1 Cd, 0.07–4.8 µg g^–1; Hg, 0.02–0.23 µg g^–1. It is suggested that tissue analysis of Enteromorpha is one of the most useful biological techniques available in estuaries for pin-pointing aqueous (as opposed to sediment) metal contamination, and also for providing data suitable for world-wide comparisons. Provisional values are given for concentrations corresponding to moderate and high pollution.Deceased     

Conflicting priorities in site management in England

There are two main designations of protected areas in the UK-nature reserves, of various kinds, and special nature conservation areas, known as Sites of Special Scientific Interest. General approaches to choices of priorities and the resolution of conflict in the management of these areas are described and difficulties identified. Similar problems arise when considering the wider role of protected areas in national nature conservation policies, e.g. biodiversity targets and European Habitats and Species Directive objectives. Because choices and priorities stem from underlying values, the public must be involved in the identification of objectives for both protected areas and the rest of the land surface. The Natural Areas programme being developed by English Nature provides a mechanism whereby people may be involved in characterising the wildlife of their area and in identifying targets for its maintenance and enhancement. The use of land and the management practices associated with it are the major factors influencing the nature conservation value of protected areas and their wider context.English Nature (the Nature Conservancy Council for England) is the statutory advisor to the government on nature conservation in England and promotes the conservation of England's wildlife and natural features.     

The ecology of the sandy estuaries of North Devon and Carmarthen Bay

The estuaries of the Taf, Tywi, Gwendraeth and Loughor (Carmarthen Bay, South Wales), and the Taw and Torridge (North Devon) were surveyed during the spring and summer of 1988, as part of a four year study of harbours, rias and estuaries in southern Britain commissioned by the Nature Conservancy Council. The aims of these surveys were to describe the major marine habitats and communities present in each estuary, and to assess their nature conservation importance. This paper outlines the results of these surveys, concentrating on the many environmental similarities between the six estuaries.     

The management of European estuaries: A comparison of the features,controls and management framework of the Tagus (Portugal) and Humber (England)

The paper describes the local, national, European and wider-area framework, statutes, and formal and voluntary mechanisms for managing European estuaries. These aspects are discussed in relation to two large and representative estuarine systems, the Tagus, Portugal, and the Humber, on the English North Sea coast As estuaries are sites of many activities and uses, most of which are encouraged or at least condoned, management has the role of preventing and resolving conflicts between those uses and users. Accepted uses of estuaries include the discharge and dumping of waste materials, fin and shell-fisheries, conservation, land reclamation, natural usage, abstraction by industry, and recreation. Estuarine management is now being carried out within the constraints of local and regional government planning, planning and activities of water pollution control bodies, fisheries control bodies, and navigation and port authorities The Tagus and Humber estuaries support all of the above activities and uses, and have controls within a European legislative framework but have differing histories of management and planning in order to resolve conflicts. In addition the Humber is subject to controls placed on North Sea areas. The paper discusses the relevant national and European legislation (Directives) and accepted practices for management. Furthermore, the paper discusses the formulation and practice of estuarine management plans as used by various bodies (nature conservation, water quality and regional authority). It is of particular note that the lessons from these two estuaries are relevant to many other European estuaries.     

Effect of stalk damage on growth and yield of certain maize cultivars by the maize stalk borer Chilo partellus

The effects of different degrees of stem tunneling caused by different levels of artificial infestation by the larvae of Chilo partellus (Swinhoe) on growth and yield of 4 maize cultivars were studied. The susceptible Inbred A suffered much more tunneling than ICZ1-CM, ICZ2-CM and Katumani Composite B. This tunneling influenced significantly the plant growth of all the four cultivars. There was a significant negative correlation between tunneling and yield for the cultivars Inbred A and Katumani Composite B, but such a relationship was not significant for ICZ1-CM and ICZ2-CM. Such differences in the relationships between tunneling and yield among the 4 cultivars are due to different degrees of tunneling caused by C. partellus larvae to the plants of these cultivars.

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Résumé L'étude a porté sur la croissance et la production avec différents niveaux de minage des tiges de 4 cultivars de maïs, lors de divers degrés de contamination artificielle par des chenilles de C. partellus. Le cultivar sensible Inbred A souffre plus des mines de C. partellus que ICZ1-CM, ICZ2-CM et Katumani composite B. Les mines influent significativement sur la croissance des 4 cultivars. Il y a une corrélation négative significative entre le minage des tiges et la production pour les cultivars Inbred A et Katumani composite B, mais la relation n'est pas significative pour ICZ1-CM et ICZ2-CM. Les différences entre le minage des tiges et la récolte des 4 cultivars sont dues aux différents degrés de minage des tiges de ces cultivars par C. partellus.

     

Brackish-water submergence of the common periwinkle,Littorina littorea,and its digenean parasites in the Baltic Sea and in the Kattegat

North Sea and Baltic Sea populations ofLittorina littorea differ with respect to their vertical distribution. In the North SeaL. littorea is strictly intertidal while in the Baltic Sea maximum population densities occur in the sublittoral. Levels of infestation with larval digenetic trematodes diminish qualitatively (number of species recorded) and quantitatively (number of hosts infested) with decreasing salinity. Both the host and two parasite species —Cryptocotyle lingua andMicrophallus pygmaeus — display brackish-water submergence under conditions of reduced surface salinity.     

Opportunistic use of estuarine habitat by juvenile bull trout, <Emphasis Type="Italic">Salvelinus confluentus</Emphasis>, from the Elwha River before,during, and after dam removal

Estuaries are used by anadromous fishes, either as the definitive marine habitat or as transition habitat as they move to fully marine waters, and extent of estuary use may vary with habitat conditions and fish attributes. Bull trout (Salvelinus confluentus) are commonly fluvial or adfluvial, though anadromous populations also exist. However, little is known about estuary use, especially by juveniles of this threatened species. We sampled the estuaries of the Elwha River, where a spawning population exists, and the nearby Salt Creek, where none exists, to reveal seasonal timing of estuarine use by juvenile bull trout, size of those using the estuary, and possible use of the non-natal estuary. We captured juvenile bull trout (all ≥100 mm FL, most <300 mm) in the Elwha River estuary in all months except August, but primarily December through May. None was captured in Salt Creek’s estuary despite comparable sampling effort. We also evaluated how dam removal on the Elwha River influenced bull trout estuarine occupancy by sampling before, during, and after dam removal, because this process enlarged the estuary but also increased turbidity and sediment transport in the lower river. Catches were low before dam removal, increased during and immediately after removal, and returned to low levels in recent years, suggesting that juveniles temporarily sought refuge from conditions associated with dam removal. Our findings indicate juvenile bull trout occupy estuarine habitat opportunistically; this information may aid conservation efforts as anadromous populations occur elsewhere in rivers with estuaries altered by human development.     

Lambda transducing phages derived from a FinO- R100::lambda cointegrate plasmid: proteins encoded by the R100 replication/incompatibility region and the antibiotic resistance determinant.

Summary Three transducing phages have been isolated from pEDR20, an R100:: cointegrate plasmid in which the insertion inactivated the R100 finO gene. Physical analysis of the three phages showed that the is inserted at kilobase coordinate 81.3 of R100. All three phages carry different amounts of R100 DNA in the left arm of . Each phage contains IS1b, the mer genes and the region between coordinate 81.3 and 88.6; thus, all contain the genes necessary for R100 replication. One phage, VA73, contains the entire r-determinant of R100 in addition to the above DNA. Five proteins coded by the region between 81.3 and 88.6 were detected. These had subunit molecular weights of 10,400; 12,200; 16,200; 19,600; and 38,300. The first was made constitutively and the other four only from a promoter. Other constitutive proteins were one from the cml fus region with a molecular weight of 22,400 (cml) and two from the str sul region with molecular weights of 31,500 (str?) and 30,100 (sul?). Mercuric ion induced synthesis of at least 10 proteins. Six of these were known from earlier work. The total size of the proteins which appear to derive from the mer genes exceeds by a factor of 1.5, the coding capacity of this region without overlapping genes. Some, or all of these extra proteins may be chromosomal in origin, possibly derepressed in response to mercury gene products.     

Potential modification of the fluxes of nitrogen from the Humber Estuary catchment (U.K.) to the North Sea in response to changing agricultural inputs and climate patterns

The catchment of the Humber Estuary drains approximately 20% of the land area of England via two main rivers, the Trent and the Ouse, and a number of tributaries. The catchment is home to major metropolitan and industrial centres, as well as to extensive areas of agricultural land; for this reason, the river and estuarine systems have been subject to considerable anthropogenic inputs. The Humber Estuary is one of the largest U.K. estuaries and the major U.K. freshwater input to the North Sea. The U.K. Natural Environment Research Council (NERC) Land Ocean Interaction Study (LOIS), which combined extensive physical and biogeochemical measurements with an integrated modelling programme, was established to examine the transport and fate of nutrients and other constituents through the land-sea boundary. In this paper, a model of nitrogen (nitrate, nitrite, ammonium, particulate nitrogen) transport and cycling in the Humber Estuary, calibrated on the basis of measured constituent concentrations at its riverine and marine boundaries, is linked off-line to a Humber catchment and rivers model of nitrogen transport, which furnished simulated constituent values at the tidal limits, and the resulting estuarine nitrogen profiles compared to those of the standalone estuarine model. The estuarine model is then re-run using simulated concentration values at the tidal limits from catchment-river model simulations incorporating realistic changes in agricultural fertiliser inputs and climate forcing functions. The standalone estuarine model simulation estimated nitrate+nitrite (total nitrogen) export to the North Sea to be ca. 53000 t in 1994 and 44000 t in 1995. Following linkage of the estuarine and catchment-river models, the estimated fluxes for these years increased by 20–30%, {relative to the standalone simulation}. Higher {winter} riverine flows largely accounted for this difference. The altered flows also markedly changed the simulated concentrations and distributions of suspended particulate matter (SPM) within the estuary, indicating strongly that the transport and fluxes of particle-reactive and particle-associated constituents would show measurable differences. Scatter in the measured SPM data precluded identification of the more precise simulation run, however. Subsequent simulations using the linked models estimated that a 50% reduction in artificial fertiliser applications within the catchment gave a 10–15% decrease in nitrogen loads to the North Sea, relative to the 1994–95 input, whilst forcing the catchment model with a climate perhaps appropriate for the mid-21st century yielded nitrogen fluxes that were similar to those of the mid-1990s.     

Calcium absorption as an index of root parameters of cucumber (Cucumis sativus L.)

Summary In a solution culture study the absorption of Ca in the shoot of cucumber (Cucumis sativus L.) and various root parameters viz fresh weight, dry weight, length and surface area were measured at weekly intervals. All the root parameters were significantly correlated (p=0.01) with the amount of Ca absorbed when the concentration of Ca was such (5 meq/l) that the absorption capacity of the root membrane was fully saturated. The use of this relationship has been suggested in estimating the amount of roots developed in the soil system where identical conditions exist with respect to Ca concentration. Such estimated values have been termed as equivalent root length or equivalent root surface area as the case may be. P and K flux into the roots growing in the soil system have been worked out from these estimates of root parameters.     

Airborne pollen dispersal and survival on mount sutton (Canada)

Summary In order to find whether or not a pattern exist in both pollen concentration and viability along altitudinal transects, samples were collected volumetrically (VPPS) each 25 m, from 500 to 825 m, on Mount Sutton (45°04N; 72°32W) (970 m). Both minimum concentration and minimum viability were found at 725 m. Airborne pollen viability was species dependent, while airborne concentrations were not specific. Sampling height influence was also investigated volumetrically (BPS), by comparing paired samples at ground and 10 m levels. Again, pollen concentration pattern was found quite stable, while viability was found to be more height influenced, particularly at 725 m. The 725 m hinge altitude is located just above the June Mean Cloud Base altitude (657 m).     

Species differences in localization of cardiac cAMP-phosphodiesterase activity: A cytochemical study

The localization of the membrane-bound cyclic 3,5-AMP phosphodiesterasein cardiac tissues of both, rat and dog was studied by cytochemical method.40 µm thick slices from glutaraldehyde fixed heart tissue wereincubated in the medium with cAMP as a substrate and Pb ions as a capturemetal of the reaction product. The cAMP-PDE activity in the rat ventriclewas only shown positive on the sarcolemma. Whereas, in canine ventriculartissue the cAMP-PDE activity in cardiomyocytes was shown on the sarcolemma,on the junctional sarcoplasmic reticulum and on subsarcolemmal cisternae.The results confirm differences in the localization of cAMP-PDE in dog andrat heart.     

Ecosystem services transcend boundaries: estuaries provide resource subsidies and influence functional diversity in coastal benthic communities

Background

Estuaries are highly productive ecosystems that can export organic matter to coastal seas (the ‘outwelling hypothesis’). However the role of this food resource subsidy on coastal ecosystem functioning has not been examined.

Methodology/Principal Findings

We investigated the influence of estuarine primary production as a resource subsidy and the influence of estuaries on biodiversity and ecosystem functioning in coastal mollusk-dominated sediment communities. Stable isotope values (δ¹³C, δ¹⁵N) demonstrated that estuarine primary production was exported to the adjacent coast and contributed to secondary production up to 4 km from the estuary mouth. Further, isotope signatures of suspension feeding bivalves on the adjacent coast (Dosinia subrosea) closely mirrored the isotope values of the dominant bivalves inside the estuaries (Austrovenus stutchburyi), indicating utilization of similar organic matter sources. However, the food subsidies varied between estuaries; with estuarine suspended particulate organic matter (SPOM) dominant at Tairua estuary, while seagrass and fringing vegetation detritus was proportionately more important at Whangapoua estuary, with lesser contributions of estuarine SPOM. Distance from the estuary mouth and the size and density of large bivalves (Dosinia spp.) had a significant influence on the composition of biological traits in the coastal macrobenthic communities, signaling the potential influence of these spatial subsidies on ecosystem functioning.

Conclusions/Significance

Our study demonstrated that the locations where ecosystem services like productivity are generated are not necessarily where the services are utilized. Further, we identified indirect positive effects of the nutrient subsidies on biodiversity (the estuarine subsidies influenced the bivalves, which in turn affected the diversity and functional trait composition of the coastal sediment macrofaunal communities). These findings highlight the importance of integrative ecosystem-based management that maintains the connectivity of estuarine and coastal ecosystems.     

Estuarine benthic ecology: A European perspective

The study of benthic ecology within European estuaries is discussed. The history of estuarine science, and the definition of an estuary is briefly reviewed. Estuarine benthic ecology is considered with regard to its geographical, economic and political context. It is shown that much recent study has been motivated by attempts to clean up estuaries, which were polluted after decades, or even centuries of pollution. Much has been achieved in the control of pollution, and many estuaries show clear signs of recovery. Particular focus has been on the estuaries entering the North Sea, with the realization that it is not the North Sea that is polluted, but its estuaries. The scientific appraisal of the benthos of estuaries has been particularly assisted by the ecosystem approach, which has both aided our understanding of their function as well as answering some of the questions posed by the impact of mankind. The European Union is identified as a powerful factor in benthic ecology, either through legislation or through the encouragement of collaborative programs, some of which have been particularly important in identifying common factors across a wide geographical spread of estuaries. It is concluded that in general estuaries have got cleaner, but that many problems remain, ranging from eutrophication through to sea-level change. The future of estuarine benthic ecology lies in meeting the new challenges.     

Survey of keratinophilic fungi inhabiting Passer domesticus in two districts of Orissa,India

The distribution patterns of keratinophilic fungi isolated from Passer domesticus of a coastal (Puri) and an intercoastal (Dhenkanal) district were compared with respect to three parameters, season, age and sex. Irrespective of the parameters, Chrysosporium tropicum and Rollandina hyalinospora showed the highest frequency of occurrence. Their occurrence in the birds was not determined by any ecological or environmental condition in nature. Thus these fungi exhibited their ecological maturity or firm establishment in nature. The maximum fungal distribution occurred during the monsoon season and was minimal in the summer. Juvenile birds were active carriers of the fungi and the male birds harboured the maximum number of fungi. Thus male juvenile birds carried the maximum number of keratinophilic fungi during the monsoon season. The free-living P. domesticus enhances the degree of dispersal of keratinophilic fungi, it being in frequent contact with human artifacts, breeding in settlements and town gardens Eusynanthropic habit. The fungi so dispersed are called mesoornithochorus as their occurrence in birds is determined to a certain degree by avian habits.     

Comparison of growth and condition indices of juvenile flatfish in differentcoastal nursery grounds

Coastal and estuarine ecosystems in the eastern channel and southern bight of the North Sea provide nursery habitats for juvenile fishes. We examined the age 0-group juveniles of three flatfish speciesSolea solea, Limanda limanda and Pleuronectes platessa, collected in five nursery areas with different characteristics (three sites located near small estuaries and two affected by important inputs of industrial effluents), to evaluate habitat influence on their growth and condition. We measured a biochemical index (RNA:DNA ratio), a morphometric index (Fultons K condition index), plus a recent growth index (marginal otolith increment width) on each individual (about 3months old), collected during surveys in autumn 1999. The three indices displayed few significant differences among the five nursery sites and different patterns for each species. We suggest that the investigated nursery areas provide habitats of equivalent quality for the age 0-group juvenile flatfishes in spite of different anthropogenic disturbances. On the other hand, this study focuses on the importance of using different biological indicators to assess habitat quality and environmental stressors in coastal areas.