bluuebunny/crossref_metadata_2025_split huggingface dataset:
The anti‐CD20 antibody rituximab augments the immunospecific therapeutic effectiveness of an anti‐CD19 immunotoxin directed against human B‐cell lymphoma
Authors: Flavell David J. , Warnes Sarah L. , Bryson Christine J. , Field Sarah A. , Noss Armorel L. , Packham Graham , Flavell Sopsamorn U. 
Published: June 2006

SummaryThe chimaeric anti‐CD20 antibody rituximab (Rituxan) sensitises lymphoma cells to small molecule cytotoxic drugs and to protein toxins. We have explored the augmentive effect of rituximab on the anti‐CD19 immunotoxin BU12‐SAPORIN in a model of human lymphoma. Intact rituximab and its F(ab)2 derivative both augmented the immunospecific protein synthesis inhibitory effects of BU12‐SAPORIN in a complement‐independent manner. A combination of rituximab + BU12‐SAPORIN completely abolished the proliferation of Ramos cells in vitro and also induced a significantly greater degree of apoptosis in these cells. Treatment with rituximab, BU12‐SAPORIN or a combination of both induced poly(ADPribose) polymerase and caspase 3 cleavage, although this was always consistently greater in combination‐treated cells. zVAD almost completely inhibited apoptosis in rituximab‐ or BU12‐SAPORIN‐treated cells but only partially in combination‐treated cells. In severe combined immunodeficient (SCID)‐Ramos mice the combination of rituximab + BU12‐SAPORIN was significantly better therapeutically than either single agent. The immunological fidelity of the therapeutic effect because of combination treatment was demonstrated through the failure of rituximab to augment an irrelevant anti‐CD7 immunotoxin. The therapeutic efficacy of rituximab and combination treatment was reduced in SCID‐Ramos mice depleted of serum complement while natural killer cell depletion failed to show any convincing role for antibody‐dependent cellular cytotoxicity. This study shows a clear therapeutic advantage from using rituximab to immunospecifically augment immunotoxin cytotoxicity warranting further investigation.
Effects of storage‐induced platelet microparticles on the initiation and propagation phase of blood coagulation
Authors: Keuren Jeffery F.W. , Magdeleyns Elke J.P. , Govers‐Riemslag José W.P. , Lindhout Theo , Curvers Joyce 
Published: June 2006

SummaryPlatelets shed microparticles, which support haemostasis via adherence to the damaged vasculature and by promoting blood coagulation. We investigated mechanisms through which storage‐induced microparticles might support blood coagulation. Flow cytometry was used to determine microparticle number, cellular origin and surface expression of tissue factor (TF), procoagulant phosphatidylserine (PtdSer) and glycoprotein (GP) Ib‐α. The influence of microparticles on initiation and propagation of coagulation were examined in activated factor X (factor Xa; FXa) and thrombin generation assays and compared with that of synthetic phospholipids. About 75% of microparticles were platelet derived and their number significantly increased during storage of platelet concentrates. About 10% of the microparticles expressed functionally active TF, as measured in a FXa generation assay. However, TF‐driven thrombin generation was only found in plasma in which tissue factor pathway inhibitor (TFPI) was neutralised, suggesting that microparticle‐associated TF in platelet concentrates is of minor importance. Furthermore, 60% of all microparticles expressed PtdSer. In comparison with synthetic procoagulant phospholipids, the maximal rate of thrombin formation in TF‐activated plasma was 15‐fold higher when platelet‐free plasma was titrated with microparticles. This difference could be attributed to the ability of microparticles to propagate thrombin generation by thrombin‐activated FXI. Collectively, our findings indicate a role of microparticles in supporting haemostasis by enhancement of the propagation phase of blood coagulation.
The abundance of juvenile yellowtail (Seriola quinqueradiata) near the Kuroshio: the roles of drifting seaweed and regional hydrography
Authors: UEHARA SHINJI , TAGGART CHRISTOPHER T. , MITANI TAKUMI , SUTHERS IAIN M. 
Published: June 2006

AbstractWe assess the effect of drifting seaweed (Sargassum sp.) biomass, geography and hydrography on juvenile yellowtail (Seriola quinqueradiata) abundance variation off the southeast coast of Japan, near the Kuroshio Current. The amount of drifting seaweed mats progressively increased northeastward into the cooler, coastal waters. Frontal structure indexed using a station‐to‐station ΔSST did not explain spatial variation in the seaweed mat distribution, although the western extent of the Kuroshio Current appeared to act as a boundary. Juvenile yellowtail constituted 51–62% of the fish collected in association with drifting seaweed mats in April 1996 and 1997 and 29% in June 1996. The abundance of juvenile yellowtail was positively correlated with seaweed biomass. The geographic distribution of juvenile yellowtail associated with drifting mats varied among sampling periods, being more southwesterly in April and more northeasterly in June. Simple multiple regression models based on seaweed biomass and geographic distribution (latitude) explained between 35% and 43% of the variation in juvenile yellowtail abundance in spring. Associations with spatial and temporal variations in hydrographic conditions did not contribute to explained variation in a meaningful manner. The results presented here indicate that, off the southeast coast of Japan during April, yellowtail juveniles are likely to be most abundant when seaweed biomass is high, occur offshore, and are bounded by the western extent of the Kuroshio Current near the 19–20°C SST isotherm.
Stock–environment–recruitment models for North Atlantic albacore (Thunnus alalunga)
Authors: ARREGUI IGOR , ARRIZABALAGA HARITZ , KIRBY DAVID S. , MARTÍN‐GONZÁLEZ JUAN MANUEL 
Published: June 2006

AbstractDifferent stock–recruitment models were fitted to North Atlantic albacore (Thunnus alalunga) recruitment and spawning stock biomass data. A classical density dependence hypothesis, a recent environmental‐dependence hypothesis and a combination of both were considered. For the latter case, four stock–environment–recruitment models were used: Ricker, Beverton‐Holt, Deriso's General Model (modified to take into account environmental effects) and conditioned Neural Networks. Cross‐validation analysis showed that the modified Deriso model had the best predictive capability. It detected an inverse effect of the North Atlantic Oscillation (NAO) on recruitment, a Ricker‐type behaviour with density dependent overcompensation when environmental conditions are unfavourable and a Beverton–Holt‐type behaviour towards an asymptotic recruitment carrying capacity with favourable environmental conditions. The Neural Network model also detected that under favourable environmental conditions high spawning stock biomass does not necessarily have a depensatory effect on recruitment. Moreover, they suggest that under extremely favourable environmental conditions, albacore recruitment could increase well above the asymptotic carrying capacity predicted by Beverton–Holt‐type models. However, the general decrease in spawning stock biomass in recent years and increasing NAO trends suggest that there is low probability of exceptionally large recruitment in the future and instead there is a danger of recruitment overfishing.
What evidence exists for alternative ecological regimes in salinising wetlands?
Authors: SIM LIEN L. , DAVIS JENNY A. , CHAMBERS JANE M. , STREHLOW KARIN 
Published: June 2006

Summary1. Land clearing in Australia's southwest has led to widespread salinisation of aquatic ecosystems. Four different ecological regimes (clear, submerged macrophyte‐dominated; clear, benthic microbial community‐dominated; turbid, phytoplankton‐dominated; and turbid, sediment‐dominated) have previously been identified in the salinising wetlands of this region.2. Monitoring data from seven saline wetlands over an 18‐month period were used to evaluate whether a continuum, simple threshold or alternative regimes conceptual model (sensu Hydrobiologia, 200/201, 1990, 367; Hydrobiologia, 200/201, 1990, 475) most appropriately represented transitions between these ecological regimes. We also aimed to identify whether factors other than salinity played a major role in defining ecological regimes or causing shifts between them.3. Ordination of biological variables revealed a separation of benthic microbial community‐dominated from submerged macrophyte‐dominated sites and times. The mean salinities of these two groups were very similar, suggesting that a salinity threshold was not responsible for benthic microbial versus macrophyte dominance. No other environmental variable was found to have a strong, direct influence on the groupings.4. The dynamics of regime change in saline wetlands appear not to be driven by any single variable, but by the combined effects of salinity and water regime on species life histories and competitive abilities. Macrophytes were powerful competitors, able to germinate and establish under a range of salinities, turbidities and water depths, and were favoured by seasonal drying.5. Data from the seven wetlands indicated that the continuum, simple threshold and alternative regimes conceptual models did not appropriately represent transitions between ecological regimes in seasonally drying wetlands. Macrophyte and benthic microbial regimes occurred at overlapping salinity levels, excluding both the continuum and threshold models, and the regular occurrence of drying appeared to preclude the alternative regimes model. Drying prevented the development of strong positive feedback mechanisms, which might otherwise have maintained the benthic microbial community‐dominated regime. We hypothesise that an alternative regimes model might still be valid for salinising ecosystems holding permanent water.
Floating mats: their occurrence and influence on shoreline distribution of emergent vegetation
Authors: AZZA NICHOLAS , DENNY PATRICK , VAN DE KOPPEL JOHAN , KANSIIME FRANK 
Published: June 2006

Summary1. A study was conducted on the northern shore of Lake Victoria (Uganda) to determine the factors controlling the occurrence of floating root mats and the influence of the floating mats on the distribution of emergent vegetation.2. Environmental conditions within 78 bays in the study area were characterised using bay size, wave exposure, water depth, littoral slope, sediment characteristics and water level fluctuations. Emergent plants that form floating root mats occur along the shores of these bays. The way in which commonly occurring shoreline vegetation was distributed across a wave‐exposure gradient was compared with their distribution across a water level fluctuation gradient.3. Results suggested that wind–wave action and water level fluctuations are important factors determining the occurrence of floating mats. Mat‐forming plants occur in the most sheltered locations along the shore and in waterbodies with modest water level fluctuations.4. The ability to form mats facilitated the lakeward expansion of emergent plants. Plants forming floating root mats had a larger depth range than non‐mat forming plants.5. The initiation mechanisms for the floating mats of emergent vegetation in Lake Victoria appear to be: (i) invasion of mats of free‐floating plants by emergent vegetation; and (ii) detachment of emergent plants from the lake bed following flooding.6. The formation of floating mats comes with a cost and benefit to emergent plants. The cost is increased vulnerability to damage by water level fluctuations or wind–wave action, leading to reduced horizontal distribution. The benefit is that deep flooding is avoided, thus increasing vertical distribution. The net effect may be to lead to dominance of mat‐forming plants in low‐energy environments and non‐mat‐forming plants in high‐energy environments.
Food web structure and function in two arctic streams with contrasting disturbance regimes
Authors: PARKER STEPHANIE M. , HURYN ALEXANDER D. 
Published: June 2006

Summary1. We studied the effect of substratum movement on the communities of adjacent mountain and spring tributaries of the Ivishak River in arctic Alaska (69°1′N, 147°43′W). We expected the mountain stream to have significant bed movement during summer because of storm flows and the spring stream to have negligible bed movement because of constant discharge.2. We predicted that the mountain stream would be inhabited only by taxa able to cope with frequent bed movement. Therefore, we anticipated that the mountain stream would have lower macroinvertebrate species richness and biomass and a food web with fewer trophic levels and lower connectance than the spring stream.3. Substrata marked in situ indicated that 57–66% of the bed moved during summer in the mountain stream and 4–20% moved in the spring stream.4. Macroinvertebrate taxon richness was greater in the spring (25 taxa) than in the mountain stream (20 taxa). Mean macroinvertebrate biomass was also greater in the spring (4617 mg dry mass m−2) than in the mountain stream (635 mg dry mass m−2). Predators contributed 25% to this biomass in the spring stream, but only 7% in the mountain stream.5. Bryophyte biomass was >1000 times greater in the spring stream (88.4 g ash‐free dry mass m−2) than the mountain stream (0.08 g ash‐free dry mass m−2). We attributed this to differences in substratum stability between streams. The difference in extent of bryophyte cover between streams probably explains the high macroinvertebrate biomass in the spring stream.6. Mean food‐web connectance was similar between streams, ranging from 0.18 in the spring stream to 0.20 in the mountain stream. Mean food chain length was 3.04 in the spring stream and 1.83 in the mountain stream. Dolly Varden char (Salvelinus malma) was the top predator in the mountain stream and the American dipper (Cinclus mexicanus) was the top predator in the spring stream. The difference in mean food chain length between streams was due largely to the presence of C. mexicanus at the spring stream.7. Structural differences between the food webs of the spring and mountain streams were relatively minor. The difference in the proportion of macroinvertebrate biomass contributing to different trophic levels was major, however, indicating significant differences in the volume of material and energy flow between food‐web nodes (i.e. food web function).
A ‘polarisation sun‐dial’ dictates the optimal time of day for dispersal by flying aquatic insects
Authors: CSABAI ZOLTÁN , BODA PÁL , BERNÁTH BALÁZS , KRISKA GYÖRGY , HORVÁTH GÁBOR 
Published: June 2006

Summary1. Daily changes in the flight activity of aquatic insects have been investigated in only a few water beetles and bugs. The diel flight periodicity of aquatic insects and the environmental factors governing it are poorly understood.2. We found that primary aquatic insects belonging to 99 taxa (78 Coleoptera, 21 Heteroptera) fly predominantly in mid‐morning, and/or around noon and/or at nightfall. There appears to be at least four different types of diurnal flight activity rhythm in aquatic insects, characterised by peak(s): (i) in mid‐morning; (ii) in the evening; (iii) both in mid‐morning and the evening; (iv) around noon and again in the evening. These activity maxima are quite general and cannot be explained exclusively by daily fluctuations of air temperature, humidity, wind speed and risks of predation, which are all somewhat stochastic.3. We found experimental evidence that the proportion (%) P(θ) of reflecting surfaces detectable polarotactically as ‘water’ is always maximal at the lowest (dawn and dusk) and highest (noon) angles of solar elevation (θ) for dark reflectors while P(θ) is maximal at dawn and dusk (low solar elevations) for bright reflectors under clear or partly cloudy skies.4. From the temporal coincidence between peaks in the diel flight activity of primary aquatic insects and the polarotactic detectability P(θ) of water surfaces we conclude that the optimal times of day for aquatic insects to disperse are the periods of low and high solar elevations θ. The θ‐dependent reflection–polarisation patterns, combined with an appropriate air temperature, clearly explain why polarotactic aquatic insects disperse to new habitats in mid‐morning, and/or around noon and/or at dusk. We call this phenomenon the ‘polarisation sun‐dial’ of dispersing aquatic insects.
The effect of suspended sediments on Lake Texoma Daphnia: field distributions and in situ incubations
Authors: SCHULZE PETER C. , GILLESPIE J. HAYLEY , WOMBLE J. RUSSELL , SILEN ALEXANDRA F. 
Published: June 2006

Summary1. We measured the abundance and eggs per female of four Daphnia species in turbid and relatively clear regions of Lake Texoma (Oklahoma‐Texas, U.S.A.) on 12 dates over the course of 5 years.2. Two species, Daphnia lumholtzi and Daphnia parvula, occurred and reproduced in turbid locations, but two other species, Daphnia mendotae and Daphnia pulicaria, occurred almost exclusively in relatively clear conditions.3. To test the hypothesis that interference with foraging excludes clear‐water Daphnia species from turbid locations, we incubated adult D. mendotae at both a clear and a turbid site. In three successive experiments D. mendotae individuals incubated at the turbid site carried as many or more eggs than individuals incubated at the clear site.
Long‐distance seed dispersal, clone longevity and lack of phylogeographical structure in the European distributional range of the coastal Calystegia soldanella (L.) R. Br. (Convolvulaceae)
Authors: Arafeh Rami , Kadereit Joachim W. 
Published: June 2006

AbstractAim  To explore the relative effects of Quaternary climatic history vs. species‐specific biological properties (high seed dispersability, high seed longevity, clonal growth) on phylogeographical structure in European Mediterranean and Atlantic Ocean and Black Sea material of the coastal dune plant Calystegia soldanella (L.) R. Br.Location  Black Sea and European Mediterranean and Atlantic Ocean coasts.Methods  Variation in amplified fragment length polymorphism was analysed at two different sampling levels. First, an entire‐range sample from the Black Sea to the North Sea, including single individuals from sites evenly spread along this entire coast was analysed. Second, in a population‐level sample, seven populations from the European Mediterranean and Atlantic Ocean coasts were analysed.Results  Neither the entire‐range nor the population‐level sampling resulted in clear phylogeographical patterns. Instead, individuals from geographically distant areas were often genetically more similar to each other than individuals from the same area. Non‐significant isolation‐by‐distance was found for both sampling approaches, and comparatively low levels of intrapopulational genetic variation were observed.Main conclusions  The lack of phylogeographical structure in C. soldanella, in comparison with the clear phylogeographical patterns observed in other coastal plant species analysed previously, is postulated to be the result of the specific biology of C. soldanella. The combination of high seed longevity, high dispersability of seeds by sea water and clonal growth and probable high clone age are likely to be responsible for the observed absence of phylogeographical structure. This implies that extreme biological properties such as those shown by C. soldanella can either erase or prevent the formation of historical patterns of genetic variation.
Species groups can be transferred across different scales
Authors: Petřík Petr , Bruelheide Helge 
Published: June 2006

AbstractAim To test whether species groups (i.e. assemblages of species co‐occurring in nature) that are statistically derived at one scale (broad, medium, or fine scale) can be transferred to another scale, and to identify the driving forces that determine species groups at the various scales.Location Northern Bohemia (Czech Republic, central Europe) in the Ještědský hřbet mountain range and its neighbourhood.Methods Three data sets were sampled: a floristic data set at the broad scale, another floristic data set at the intermediate scale, and a vegetation data set at the habitat scale. First, in each data set, species groups were produced by the COCKTAIL algorithm, which ensures maximized joint occurrence in the data set using a fidelity coefficient. Corresponding species groups were produced in the individual data sets by employing the same species for starting the algorithm. Second, the species groups formed in one data set, i.e. at a particular scale, were applied crosswise to the other data sets, i.e. to the other scales. Correspondence of a species group formed at a particular scale with a species group at another scale was determined. Third, to highlight the driving factors for the distribution of the plant species groups at each scale, canonical correspondence analysis was carried out.Results Twelve species groups were used to analyse the transferability of the groups across the three scales, but only six of them were found to be common to all scales. Correspondence of species groups derived from the finest scale with those derived at the broadest scale was, on average, higher than in the opposite direction. Forest (tree layer) cover, altitude and bedrock type explained most of the variability in canonical correspondence analysis across all scales.Main conclusions Transferability of species groups distinguished at a fine scale to broader scales is better than it is in the opposite direction. Therefore, a possible application of the results is to use species groups to predict the potential occurrence of missing species in broad‐scale floristic surveys from fine‐scale vegetation‐plot data.