bluuebunny/crossref_metadata_2025 huggingface dataset:
Ecosystem engineering by larvae of net‐spinning stream caddisflies creates a habitat on the upper surface of stones for mayfly nymphs with a low resistance to flows
Authors: NAKANO DAISUKE , YAMAMOTO MASAMICHI , OKINO TOKIO
Published: August 2005

1. Field and laboratory experiments were conducted to examine the effect of larval retreats of the net‐spinning stream caddisfly Hydropsyche orientalis on abundances on flow exposed stone surfaces of nymphs of the mayfly Ephemerella setigera, which prefer slow flow conditions, and to determine whether the construction of retreats ameliorated the habitat and made it more suitable for E. setigera.

2. In a field experiment, artificial substrates with retreats of H. orientalis had higher E. setigera abundances than substrates lacking retreats. In addition, abundances of E. setigera nymphs increased significantly with those of H. orientalis larvae on the upper surface of boulders in streams.

3. The drift loss of E. setigera from plates, with and without retreats, was investigated along a current velocity gradient in a laboratory channel experiment. Nearly all E. setigera nymphs remained on the plates with retreats, even at the highest current velocity. In contrast, on the plates without retreats, the drift loss of E. setigera nymphs increased as the current velocity increased.

4. These results suggested that the habitat amelioration by H. orientalis retreats provided a refuge location for E. setigera nymphs and increased their abundances on stone surfaces exposed to flow forces.
On the ecology of the rotiferCephalodella hoodifrom an extremely acidic lake
Authors: WEITHOFF GUNTRAM
Published: August 2005

1. The biovolume‐specific carbon content, relative egg volume (a measure of per‐offspring reproductive investment), growth and grazing rates, and the gross growth efficiency (GGE) of the rotiferCephalodella hoodi, isolated from an extremely acidic habitat (pH 2.65), were determined and compared with literature values for rotifers living in circum‐neutral habitats in order to reveal potential special features or adaptations related to the extreme habitat ofC. hoodi.

2. Of the two dominant phytoflagellates (Ochromonassp. andChlamydomonas acidophila) that occur in the natural habitat ofC. hoodi, onlyC. acidophilapromoted positive growth and reproduction and, thus, the following results were obtained withC. acidophilaas a food alga.

3. The body volume‐specific carbon content ofC. hoodiis in the range of that found in rotifers from circum‐neutral lakes, suggesting that no costly carbon investment, brought about by the thickening of the lorica, for example, was required to withstand low pH.

4. The egg volume ofC. hoodiexhibited no phenotypic plasticity dependent on the food concentration and, thus,C. hoodiallocated a constant, absolute amount of energy to each individual offspring. No adaptation to low food densities was found.

5. A dome‐shaped type II functional response curve was found to describe the ingestion ofChlamydomonasas a source of food.

6. Compared with other rotifers,C. hoodihad a high threshold and half‐saturating food concentration (=low affinity) but also a high maximum growth rate and a relatively high GGE, suggesting no severe adverse effect of low pH.
Recruitment, kin and the spatial genetic structure of a caddisfly Plectrocnemia conspersa in a southern English stream
Authors: WILCOCK HELEN R. , BRUFORD MICHAEL W. , HILDREW ALAN G. , NICHOLS RICHARD A.
Published: August 2005

1. Our objectives were to examine small‐scale patterns in oviposition and genetic relatedness in a population of the stream‐dwelling caddis Plectrocnemia conspersa and, in particular, to look for any evidence of the spatial proximity of close kin and, therefore, ‘patchy recruitment’.

2. In order to examine the distribution of related larvae at the beginning of the aquatic phase, we searched the stream for egg masses. Spatially and temporally structured samples of larvae were then collected from the stream over four sample dates within one generation. The genetic relatedness of these field‐collected larvae, estimated using six polymorphic microsatellite loci, was subsequently compared with that of larvae reared from individual egg masses in the laboratory.

3. Egg masses were laid in clusters or ‘hot spots’ along the stream. The mean relatedness coefficient within reared egg masses ranged from 0.327 to 0.525, and differed significantly from that estimated for the population as a whole (0.070), indicating that the markers were sufficiently powerful to identify groups of siblings. Each egg mass was likely to be the progeny of one father, although the possibility of a small contribution from a second male could not be excluded for a few masses.

4. Mean relatedness within the spatially structured groups of larvae in the stream, even those in close proximity to each other, did not differ from the background population level estimate, suggesting that siblings disperse away from each other very quickly and that kin structure does not persist over time.

5. Changes in spatial genetic structure late in the larval life indicated that neighbouring larvae were less closely related than the population overall, possibly suggesting some direct or indirect means of avoiding kin when approaching the onset of pupation.

6. Our counts of egg masses suggested that survival through the egg stage and early larval life was apparently very high (>50%) for a non‐social insect, and may be a consequence of the colonial net that is briefly occupied by first instar larvae.

7. The number of egg masses laid in the stream (approximately 400 in the sample year), the lack of a spatial genetic structure showing evidence of families even early in larval life, and the high survival of eggs and early instar larvae, all refute the ‘patchy recruitment hypothesis’ for this species.
Meiobenthic response to river‐borne benthic particulate matter – a microcosm experiment
Authors: WITTHÖFT‐MÜHLMANN ANDRÉ , TRAUNSPURGER WALTER , ROTHHAUPT KARL OTTO
Published: August 2005

1. Benthic communities inhabiting river–lake interfaces are confronted with temporal variation in the import of river‐borne material to the associated littoral zone. The primary objective of this study was to evaluate the exposure to river‐borne benthic particulate matter as a force shaping the meiofauna of the river–lake interface.

2. In a 2 × 2 factorial design, combinations of strongly and weakly river‐influenced communities (near or far from the river mouth) with and without river‐borne benthic particulate matter enrichment were studied in laboratory microcosms to assess the response of the heterotrophic meiobenthos to river‐borne matter.

3. Nematodes dominated both habitat types and were the only meiofaunal taxon that responded to the enrichment.

4. A strong interactive effect between experimental enrichment and location of site was observed. Whereas nematodes from the littoral habitat close to the river mouth responded to the enrichment only marginally, nematodes from the remote site were strongly affected in the presence of river‐borne particulate matter.

5. In the non‐enriched samples of the remote site, the number of nematodes increased greatly over time. Among nematode feeding types, deposit feeders dominated over chewers at the beginning of the experiment but both types were equally abundant at the end. In the presence of river‐borne matter the increase of chewers ceased and a shift in feeding type composition did not occur.

6. It was shown that for river–lake interface meiofaunal assemblages in relative proximity, the same taxon might respond differently if exposed to an external pressure, e.g. river‐borne components. These components may have a stronger influence on taxa with longer life cycles.
Orthogonal vibroseis sweeps
Authors: Xia J. , Geier N.A. , Miller R.D. , Tapie C.R.
Published: August 2005

Vibroseis is a method that imparts coded seismic energy into the ground. The energy is recorded with geophones and then processed using the known (coded) input signal. The resulting time‐domain representation of vibroseis data is an impulsive wavetrain with wavelet properties consistent with the coded input signal convolved with the earth's reflectivity series. Historically, vibratory seismic surveys collect data from one source location at a time, summing one or more sources at each location. We present a method of designing orthogonal sweeps using the concept of combisweeps. The orthogonal sweeps allow simultaneous recording and later separation of two or more unique source locations. Orthogonality of sweeps permits separation of the data into unique source‐location field records by a conventional correlation procedure. The separation power of the orthogonal sweeps is demonstrated by a comparison between separated data and data acquired with one vibrator. Separation noise was at a negligible level for our demonstration data sets when two vibrators were located 50 m to 200 m apart. Coincident generation and recording of two vibroseis sweeps at different locations would allow almost double the amount of data to be recorded for a given occupation time and requires only half the storage medium.
τ‐migration and velocity analysis: application to data from the Red Sea
Authors: Alkhalifah Tariq
Published: August 2005

Imaging pre‐salt reflections for data acquired from the coastal region of the Red Sea is a task that requires prestack migration velocity analysis. Conventional post‐stack time processing lacks the lateral inhomogeneity capability, necessary for such a problem. Prestack migration velocity analysis in the vertical time domain reduces the velocity–depth ambiguity that usually hampers the performance of prestack depth‐migration velocity analysis. In prestack τ‐migration velocity analysis, the interval velocity model and the output images are defined in τ (i.e. vertical time). As a result, we avoid placing reflectors at erroneous depths during the velocity analysis process and thus avoid inaccurately altering the shape of the velocity model, which in turn speeds up the convergence to the true model. Using a 1D velocity update scheme, the prestack τ‐migration velocity analysis produces good images of data from the Midyan region of the Red Sea. For the first seismic line from this region, only three prestack τ‐migration velocity analysis iterations were required to focus pre‐salt reflections in τ. However, the second line, which crosses the first line, is slightly more complicated and thus required five iterations to reach the final, reasonably focused, τ‐image. After mapping the images for the two crossing lines to depth, using the final velocity models, the placements of reflectors in the two 2D lines were consistent at their crossing point. Some errors occurred due to the influence of out‐of‐plane reflections on 2D imaging. However, such errors are identifiable and are generally small.
An enhanced method for source parameter imaging of magnetic data collected for mineral exploration
Authors: Smith Richard S. , Salem Ahmed , Lemieux Jean
Published: August 2005

We have developed a method for imaging magnetic data collected for mineral exploration to yield the following structural information: depth, model type (structural index) and susceptibility. The active nature of mineral exploration data requires we derive the structural information from a robust quantity: we propose that the first‐ or second‐order analytic‐signal amplitude is suitably stable. The procedure is to normalize the analytic‐signal amplitude by the peak value and then use non‐linear inversion to estimate the depth and the structural index for each anomaly. In our field example, different results are obtained depending on whether we inverted for the first‐ or second‐order analytic‐signal amplitude. This is probably because the two‐dimensional contact, thin sheet or horizontal cylinder models we have assumed are not appropriate. In cases such as these, when our model assumptions are not correct, the results should not be interpreted quantitatively, but they might be useful for giving a qualitative indication of how the structure might vary.

With a priori information, it is possible to assume a model type (i.e. set the structural index) and generate estimates of the depth and susceptibility. These data can then be gridded and imaged. If a contact is assumed, the susceptibility contrast is estimated; for the dike model, the susceptibility‐thickness is estimated; for the horizontal cylinder, the susceptibility‐area is estimated. To emphasize that the results are dependent on our assumed model, we advocate prefixing any derived quantity by the term ‘apparent’.
Seismic anisotropy of shales
Authors: Sayers C.M.
Published: August 2005

Shales are a major component of sedimentary basins, and they play a decisive role in fluid flow and seismic‐wave propagation because of their low permeability and anisotropic microstructure. Shale anisotropy needs to be quantified to obtain reliable information on reservoir fluid, lithology and pore pressure from seismic data, and to understand time‐to‐depth conversion errors and non‐hyperbolic moveout. A single anisotropy parameter, Thomsen's δ parameter, is sufficient to explain the difference between the small‐offset normal‐moveout velocity and vertical velocity, and to interpret the small‐offset AVO response. The sign of this parameter is poorly understood, with both positive and negative values having been reported in the literature. δ is sensitive to the compliance of the contact regions between clay particles and to the degree of disorder in the orientation of clay particles. If the ratio of the normal to shear compliance of the contact regions exceeds a critical value, the presence of these regions acts to increase δ, and a change in the sign of δ, from the negative values characteristic of clay minerals to the positive values commonly reported for shales, may occur. Misalignment of the clay particles can also lead to a positive value of δ. For transverse isotropy, the elastic anisotropy parameters can be written in terms of the coefficients W200 and W400 in an expansion of the clay‐particle orientation distribution function in generalized Legendre functions. For a given value of W200, decreasing W400 leads to an increase in δ, while for fixed W400, δ increases with increasing W200. Perfect alignment of clay particles with normals along the symmetry axis corresponds to the maximum values of W200 and W400, given by and . A comparison of the predictions of the theory with laboratory measurements shows that most shales lie in a region of the (W200, W400)‐plane defined by W400/W200≤Wmax400/Wmax200.
Elastic properties of double‐porosity rocks using the differential effective medium model
Authors: Markov M. , Levine V. , Mousatov A. , Kazatchenko E.
Published: August 2005

An approach to determining the effective elastic moduli of rocks with double porosity is presented. The double‐porosity medium is considered to be a heterogeneous material composed of a homogeneous matrix with primary pores and inclusions that represent secondary pores. Fluid flows in the primary‐pore system and between primary and secondary pores are neglected because of the low permeability of the primary porosity. The prediction of the effective elastic moduli consists of two steps. Firstly, we calculate the effective elastic properties of the matrix with the primary small‐scale pores (matrix homogenization). The porous matrix is then treated as a homogeneous isotropic host in which the large‐scale secondary pores are embedded. To calculate the effective elastic moduli at each step, we use the differential effective medium (DEM) approach. The constituents of this composite medium – primary pores and secondary pores – are approximated by ellipsoidal or spheroidal inclusions with corresponding aspect ratios.

We have applied this technique in order to compute the effective elastic properties for a model with randomly orientated inclusions (an isotropic medium) and aligned inclusions (a transversely isotropic medium). Using the special tensor basis, the solution of the one‐particle problem with transversely isotropic host was obtained in explicit form.

The direct application of the DEM method for fluid‐saturated pores does not account for fluid displacement in pore systems, and corresponds to a model with isolated pores or the high‐frequency range of acoustic waves. For the interconnected secondary pores, we have calculated the elastic moduli for the dry inclusions and then applied Gassmann's tensor relationships. The simulation of the effective elastic characteristic demonstrated that the fluid flow between the connected secondary pores has a significant influence only in porous rocks containing cracks (flattened ellipsoids). For pore shapes that are close to spherical, the relative difference between the elastic velocities determined by the DEM method and by the DEM method with Gassmann's corrections does not exceed 2%. Examples of the calculation of elastic moduli for water‐saturated dolomite with both isolated and interconnected secondary pores are presented. The simulations were verified by comparison with published experimental data.
Instantaneous polarization attributes in the time–frequency domain and wavefield separation
Authors: Diallo M.S. , Kulesh M. , Holschneider M. , Scherbaum F.
Published: August 2005

We introduce a method of wavefield separation from multicomponent data sets based on the use of the continuous wavelet transform. Our method is a further generalization of the approach proposed by Morozov and Smithson, in that by using the continuous wavelet transform, we can achieve a better separation of wave types by designing the filter in the time–frequency domain. Furthermore, using the instantaneous polarization attributes defined in the wavelet domain, we show how to construct filters tailored to separate different wave types (elliptically or linearly polarized), followed by an inverse wavelet transform to obtain the desired wave type in the time domain. Using synthetic and experimental data, we show how the present method can be used for wavefield separation.
Spatial and structural uniformity of lowland agricultural grassland in England: a context for low biodiversity
Authors: Tallowin J. R. B. , Smith R. E. N. , Goodyear J. , Vickery J. A.
Published: August 2005

The contention that agricultural grassland within the UK is spatially and structurally uniform across wide differences in livestock farming intensity is examined. Total nitrogen (N) input was used as a surrogate for management intensity. Farms with average annual N inputs of >200 kg ha−1 were categorized as highly intensive, those with N inputs of 50–200 kg N ha−1 as moderately intensive and those with inputs of <50 kg N ha−1 were categorized as extensive. Four farms within each management category were selected in two discrete regions: one in south‐west England, typifying a landscape dominated by agricultural grassland, the other in south‐east England with a more mixed‐farming landscape. Specific N input and management data, and sward botanical composition and structure, were obtained on four fields per farm. The south‐west region had a higher proportion of farms with dairy cattle than in the south‐east England region. The average N input and stocking rates were higher within the intensive‐management category farms in south‐west England than in south‐east England. Old permanent grasslands contained variable amounts of sown species, such as Lolium perenne, and were dominated by a few (generally <5) non‐sown grass species. Grassland that received >75 kg N ha −1 year−1 contained <7 plant species and <3 forb species m−2. Grassland communities with >12 plant species and >5 forb species m−2 were only found in study fields that received <50 kg N ha−1 year−1. Grasslands with >10 forb species m−2 were found only in sites receiving <15 kg N ha−1. Of importance at a landscape scale was ubiquity of species‐poor and similar grassland plant communities across the management intensity range within and between livestock farms. Grassland in the extensive management category was similar in structure in terms of sward height and/or sward density to more intensively managed grasslands. This study revealed, albeit in two lowland sample regions in the UK, the ubiquity of grass‐dominated, species‐poor and structurally uniform grasslands, irrespective of apparently broad differences in farming intensity. The consequences of this spatial uniformity on grassland biodiversity are likely to be profound.
Use of a systems synthesis approach to model nitrogen losses from dairy farms in south‐west England
Authors: Cuttle S. P. , Jarvis S. C.
Published: August 2005

Nitrogen (N) budgets were determined for six typical, moderately intensive dairy farms in south‐west England. Proportionately, only 0·12–0·17 of the N input to the farms was recovered in agricultural products, leaving annual N surpluses equivalent to 249–376 kg N ha−1. A sequence of models (MANNER, NCYCLE and SUNDIAL) was used, together with the estimated N balance of the dairy cows and standard ammonia emission factors, to estimate N losses for each farm. Total estimated losses were equivalent to 137–220 kg N ha−1 year−1. Leaching accounted for 0·26–0·45 of the total loss, ammonia volatilization for 0·27–0·39 and denitrification for 0·17–0·36. When residual N from manure applications was included, there appeared to be an annual accumulation of soil N, equivalent to 66–158 kg N ha−1 when averaged over the whole farm area. The amounts of N lost by leaching, volatilization and denitrification, and accumulated as soil‐N, were determined by a combination of farm properties, including N input, soil type, drainage, characteristics of the manure produced and type of fertilizer. The sum of estimated losses and change in N retained on the farm was between 0·85 and 1·11 of the N surplus (input minus output) determined from the farm budget. This suggests that losses and the change in soil‐N were underestimated on some farms and overestimated on others (by up to −50 and +23 kg N ha−1 respectively). Much of the discrepancy between estimates and the surplus was attributed to difficulties of fully integrating inputs and outputs between the different models and stages of the modelling procedure.
Effects of perennial ryegrass (Lolium perenne L.) cultivars on herbage production, nutritional quality and herbage intake of grazing dairy cows
Authors: Smit H. J. , Tas B. M. , Taweel H. Z. , Tamminga S. , Elgersma A.
Published: August 2005

Four perennial ryegrass (Lolium perenne L.) cultivars were compared for differences in herbage production, nutritive value and herbage intake of dry matter (DM) during the summers of 2002 and 2003. Two paddocks were sown with pure stands of four cultivars in a randomized block design with three replicates. Each plot was subdivided into fourteen subplots (22 m × 6 m) which were grazed by one cow during 24 h. Twelve lactating dairy cows were assigned to one cultivar for a period of 2 weeks in a 4 × 4 Latin square experimental design; the experiment lasted 8 weeks in each year. Sward structure (sward surface height, DM yield, green leaf mass, bulk density and tiller density) and morphological characteristics were measured. The ash, neutral‐detergent fibre, acid‐detergent lignin, crude protein and water‐soluble carbohydrate concentrations, and in vitro digestibility of the herbage were measured. The sward was also examined for infestation by crown rust (Puccinia coronata f. sp. lolii). Herbage intake of dairy cows was estimated using the n‐alkane technique. Cultivar differences for all sward structural characteristics were found except for bulk density and tiller density in 2003. Cultivars differed for proportions of pseudostem, stem (in 2003 only) and dead material. The chemical composition of the herbage was different among cultivars, with the water‐soluble carbohydrate concentration showing large variation (>0·35). Cultivars differed in susceptibility to crown rust. Herbage intake differed among cultivars in 2002 (>2 kg DM) but not in 2003. Herbage intake was positively associated with sward height, DM yield and green leaf mass. Canopy morphology did not affect herbage intake. Crown rust affected herbage intake negatively. It was concluded that options for breeders to select for higher intake were limited. High‐yielding cultivars and cultivars highly resistant to crown rust were positively related with a high herbage intake.
Differential responses of cord and adult blood‐derived dendritic cells to dying cells
Authors: Wong On Hang , Huang Fang‐Ping , Chiang Alan K. S.
Published: August 2005

Normal turnover of body tissues yields apoptotic cells while infections cause tissue injuries and cell necrosis. The interaction of these dying cells with dendritic cells (DCs) may provide immunological instructions leading to either immune tolerance or activation. We hypothesize that neonatal and adult DCs differ in their responses to dying cells, thereby contributing to the observed differences in immune responses between neonates and adults. We compare the outcome of interaction of cord and adult blood‐derived DCs with dying Epstein–Barr‐virus‐transformed lymphoblastoid cells (LCLs) and the responsiveness to lipopolysaccharide. While cord DCs were able to phagocytose both apoptotic and necrotic LCLs, the subsequent responses differed significantly from those of adult DCs. Interaction of adult DCs with necrotic but not early apoptotic LCLs resulted in high expression of DC costimulatory molecules (CD80/CD86) and activation markers (CD83), production of both proinflammatory and anti‐inflammatory cytokines (tumour necrosis factor‐α, interleukin‐10), and strong T‐cell‐stimulating activities. In contrast, in response to either necrotic or apoptotic LCLs, cord DCs had minimal up‐regulation of those DC functional markers, little cytokine production and poor stimulation on T‐cell proliferation. In response to lipopolysaccharide, however, both adult and cord DCs produced comparable levels of tumour necrosis factor‐α and interleukin‐10, but only adult DCs produced interleukin‐12(p70). Taken together, these results suggest that neonatal DCs generally favour immune tolerance with minimal activation and cytokine production, except in extremely dangerous situations, such as bacterial sepsis, when neonatal DCs may produce certain types of cytokines and stimulate T‐cell proliferation.
Detection, epitope‐mapping and function of anti‐Fas autoantibody in patients with silicosis
Authors: Takata‐Tomokuni Akiko , Ueki Ayako , Shiwa Mieko , Isozaki Yumika , Hatayama Tamayo , Katsuyama Hironobu , Hyodoh Fuminori , Fujimoto Wataru , Ueki Hiroaki , Kusaka Masayasu , Arikuni Hisashi , Otsuki Takemi
Published: August 2005

Dysregulation of apoptosis through the Fas–Fas ligand pathway is associated with the onset of autoimmune disease. Since autoantibodies directed against unknown antigens are present in the sera of these patients, sera samples were examined for the presence of autoantibodies directed against the Fas molecule. Using Western blotting and a ProteinChip analysis, autoantibodies against Fas were detected in patients with silicosis, systemic lupus erythematosus (SLE) and systemic sclerosis (SSc), and weakly detected in healthy individuals. Using epitope mapping employing 12‐amino‐acid polypeptides with the SPOTs system, a minimum of four epitopes and a maximum of 10 epitopes were found. Several amino acid residues involved in binding FasL, such as C66, R87, L90, E93 and H126, were presented within the epitopes. Serum containing a large amount of anti‐Fas autoantibody from silicosis patients inhibited the growth of a Fas‐expressing human cell line, but did not inhibit the growth of a low Fas‐expresser nor a Fas‐expresser in which the Fas gene had been silenced by small interference RNA. All epitopes in the intracellular region of Fas were located in the death domain. The possible roles of anti‐Fas autoantibody detected in healthy volunteers and patients with silicosis or autoimmune diseases are discussed here.
Phenotypical and functional alterations during the expansion phase of invariant Vα14 natural killer T (Vα14i NKT) cells in mice primed with α‐galactosylceramide
Authors: Ikarashi Yoshinori , Iizuka Akira , Koshidaka Yumie , Heike Yuji , Takaue Yoichi , Yoshida Mitsuzi , Kronenberg Mitchell , Wakasugi Hiro
Published: August 2005

Invariant Vα14 natural killer T (Vα14i NKT) cells are a unique immunoregulatory T‐cell population that is restricted by CD1d. The glycolipid α‐galactosylceramide (α‐GalCer) is presented by CD1d and causes robust Vα14i NKT‐cell activation. Three days after injection of α‐GalCer, Vα14i NKT cells vigorously increase in number and then gradually decrease to normal levels. In the present study, we found that the re‐administration of α‐GalCer into mice primed 3 days earlier causes a marked increase in serum interleukin‐4 and interferon‐γ. Intracellular staining revealed that the only expanded Vα14i NKT cells are responsible for the enhanced cytokine production. The enhanced cytokine production was correlated with an increased number of Vα14i NKT cells after priming. Additionally, primed Vα14i NKT cells produced larger amounts of cytokine as compared with naive Vα14i NKT cells when cultured with α‐GalCer‐pulsed dendritic cells. Thus, we considered that a subset of expanded Vα14i NKT cells acquired a strong ability to produce cytokines. In contrast to mice primed 3 days earlier, cytokine production is markedly diminished in mice primed 7 days earlier. The expanded Vα14i NKT cells altered the surface phenotype (NK1.1– CD69–) and contained intracellular interferon‐γ. Additionally, we found that primed Vα14i NKT cells did not disappear or down‐regulate surface TCR expression when re‐injected with α‐GalCer as compared with naive Vα14i NKT cells. These results demonstrate that the function and surface phenotype of Vα14i NKT cells is dramatically altered after α‐GalCer priming.
Characterization of the B‐cell immune response elicited in BALB/c mice challenged with Neospora caninum tachyzoites
Authors: Teixeira Luzia , Marques Andreia , Meireles Carla Sofia , Seabra Ana Rita , Rodrigues Diana , Madureira Pedro , Faustino Augusto M. R. , Silva Carolina , Ribeiro Adília , Ferreira Paula , Correia da Costa José Manuel , Canada Nuno , Vilanova Manuel
Published: August 2005

Activation of B cells occurring in hosts infected with protozoan parasites has been implicated either in protective or parasite‐evasion immune‐mediated mechanisms. Intraperitoneal inoculation of Neospora caninum tachyzoites into BALB/c mice induces an acute response characterized by a rapid increase in the numbers of CD69‐expressing peritoneal and splenic B cells. This early B‐cell stimulatory effect preceded an increase in the numbers of total and immunoglobulin‐secreting splenic B cells and a rise in serum levels of N. caninum‐specific immunoglobulins, predominantly of the immunoglobulin G2a (IgG2a) and IgM isotypes. Increased numbers of B cells expressing the costimulatory molecules CD80 and CD86 were also observed in the N. caninum‐infected mice. The B‐cell stimulatory effect observed in mice challenged with N. caninum tachyzoites was reduced in mice challenged with γ‐irradiated parasites. Contrasting with the peripheral B‐cell expansion, a depletion of B‐lineage cells was observed in the bone‐marrow of the N. caninum‐infected mice. Intradermal immunization of BALB/c mice with diverse N. caninum antigenic preparations although inducing the production of parasite‐specific antibodies nevertheless impaired interferon‐γ (IFN‐γ) mRNA expression and caused lethal susceptibility to infection in mice inoculated with a non‐lethal parasitic inoculum. This increased susceptibility to N. caninum was not observed in naïve mice passively transferred with anti‐N. caninum antibodies. Taken together, these results show that N. caninum induces in BALB/c mice a parasite‐specific, non‐polyclonal, B‐cell response, reinforce previous observations made by others showing that immunization with N. caninum whole structural antigens increases susceptibility to murine neosporosis and further stress the role of IFN‐γ in the host protective immune mechanisms against this parasite.
Identification of specific autoantigens in Sjögren's syndrome by SEREX
Authors: Uchida Kazuo , Akita Yoichi , Matsuo Keitaro , Fujiwara Shigeyoshi , Nakagawa Atsuko , Kazaoka Yoshiaki , Hachiya Hiroshi , Naganawa Yoshiyuki , Oh‐iwa Ichiro , Ohura Kiyoshi , Saga Shinsuke , Kawai Tatsushi , Matsumoto Yoshinari , Shimozato Kazuo , Kozaki Ken‐ichi
Published: August 2005

We carried out SEREX (serological analysis of antigens by recombinant cDNA expression cloning) using sera from patients with Sjögren's syndrome (SjS) and investigated the frequencies of autoantibodies against autoantigens identified by SEREX in the sera of healthy individuals (HI) and patients with SjS, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). IFI16 and two kelch‐like proteins, KLHL12 and KLHL7, were found to be novel autoantigens in SjS by SEREX. A markedly high frequency of anti‐IFI16 autoantibodies was observed in the sera of SjS (SjS, 70%; RA, 13%; SLE, 33%; HI, 0%). Interestingly, all serum samples from SjS demonstrated immunoreactivity against one or both of IFI16 and SS‐B/La. The presence of autoantibodies against KLHL12 and KLHL7 in the sera was significantly specific to SjS (23% and 17%, respectively), as they were not detected in RA, SLE or HI. Furthermore, we confirmed that transcripts of these autoantigens were expressed preferentially in the salivary glands and immuno‐privileged testes. Our results suggest these autoantigens may be useful as serological markers for the clinical diagnosis of SjS and may play a crucial role as organ‐specific autoantigens in the aetiopathogenesis of SjS. This study warranted clinical evaluations of autoantibodies against IFI16, KLHL12 and KLHL7 in combination with anti‐SS‐B/La autoantibodies.
Mechanism of up‐regulation of immunoglobulin A production in the intestine of mice unresponsive to lipopolysaccharide
Authors: Kaneko Masahiro , Akiyama Yoshiyuki , Takimoto Hiroaki , Kumazawa Yoshio
Published: August 2005

The mechanisms by which immunoglobulin A (IgA) production up‐regulates in the intestine of Toll‐like receptor‐4 (TLR4)‐mutated mice were investigated. When TLR4‐mutated, C3H/HeJ and BALB/lpsd mice received oral administration of cholera toxin (CT), not only CT‐specific IgA levels in the intestinal lavage but also the number of IgA‐producing cells in intestinal lamina propria (iLP) significantly increased compared with those of the wild‐type C3H/He and BALB/c mice. Interleukin (IL)‐5‐producing cells and CD86+ cells in iLP also significantly increased in C3H/HeJ mice. The expression of major histocompatibility complex class II and CD86 on cells present in Peyer's patches (PPs) of C3H/HeJ mice was higher than those of C3H/He mice. In non‐immunized C3H/HeJ mice, the expression of transforming growth factor‐β (TGF‐β) mRNA and the percentages of IL‐10‐producing cells in PPs but not in spleen increased when compared with those in C3H/He mice. The suppressor of cytokine signalling‐1 (SOCS‐1) was expressed in PPs of C3H/He mice but not C3H/HeJ mice. These results indicate that high IgA levels in the intestine of TLR4‐mutated mice are due to up‐regulation of TGF‐β and IL‐10 and the lack of regulation by SOCS‐1.
Formononetin, a phyto‐oestrogen, and its metabolites up‐regulate interleukin‐4 production in activated T cells via increased AP‐1 DNA binding activity
Authors: Park Jin , Kim Seung H. , Cho Daeho , Kim Tae S.
Published: August 2005

Phyto‐oestrogens are polyphenolic non‐steroidal plant compounds with oestrogen‐like biological activity. Phyto‐oestrogens have many biological effects including oestrogen agonist/antagonist properties. However, the effect of phyto‐oestrogens on allergic responses remains unclear. In this study we investigated whether formononetin, a phyto‐oestrogen, and its metabolites, daidzein and equol, affect production of interleukin‐4 (IL‐4), a pro‐inflammatory cytokine closely associated with allergic immune response, in primary CD4+ T cells and EL4 T lymphoma cells. Formononetin, daidzein and equol significantly enhanced IL‐4 production from both CD4+ T cells and EL4 cells in a dose‐dependent manner. Formononetin, daidzein and equol also enhanced IL‐4 gene promoter activity in EL4 cells transiently transfected with IL‐4 gene promoter constructs, but this effect was impaired in EL4 cells transfected with an IL‐4 promoter construct deleted of P4 site carrying nuclear factor of activated T cells (NF‐AT) and activator protein‐1 (AP‐1) binding sites. In addition, formononetin, daidzein and equol increased AP‐1 DNA binding activities while did not affect NF‐AT DNA binding activities. The enhancing effects on IL‐4 production and AP‐1 DNA binding activities were abrogated by specific inhibitors for phosphatidylinositol‐3‐kinase (PI3K), protein kinase C (PKC) and p38 mitogen‐activated protein kinase (MAPK), indicating that formononetin, daidzein and equol might enhance IL‐4 production by increased activation of AP‐1 through the PI3‐K/PKC/p38 MAPK signalling pathway. These results suggest that phyto‐oestrogens and some of their metabolites may increase allergic responses via the enhancement of IL‐4 production in T cells.
Regulatory activity of human CD4+ CD25+ T cells depends on allergen concentration, type of allergen and atopy status of the donor
Authors: Bellinghausen Iris , König Bettina , Böttcher Ingo , Knop Jürgen , Saloga Joachim
Published: August 2005

Regulatory CD4+ CD25+ FoxP3‐positive T cells (Treg) are functional in most atopic patients with allergic rhinitis and are able to inhibit T helper type 1 (Th1) and Th2 cytokine production of CD4+ CD25– T cells. This study was designed to analyse the following additional aspects: influence of allergen concentration, influence of the type of allergen, and influence of the atopy status of the donor on the strength of the regulatory activity. CD4+ CD25– T cells from healthy non‐atopic controls or from grass‐pollen‐allergic or wasp‐venom‐allergic donors were stimulated alone or in the presence of Treg with autologous mature monocyte‐derived dendritic cells which were pulsed with different concentrations of the respective allergens. Treg from grass‐pollen‐allergic donors failed to inhibit proliferation but not cytokine production of CD4+ CD25– T cells at high antigen doses while Treg from non‐atopic donors did not fail at these allergen concentrations. Proliferative responses and cytokine production of CD4+ CD25– T cells from most of the examined wasp‐venom‐allergic patients were not inhibited at any concentration of wasp venom. The use of wasp venom‐ or phospholipase A2‐pulsed dendritic cells for stimulation of CD4+ CD25– T cells from donors who were not allergic to wasp stings only resulted in an inhibited proliferation and Th2 cytokine production by Treg at 10‐fold lower than the optimal concentration, while interferon‐γ production was inhibited at all concentrations investigated. These data demonstrate that in allergic diseases the function of Treg is dependent on the concentration and the type of the respective allergen with different thresholds for individual allergens and patients.
Dysregulated luminal bacterial antigen‐specific T‐cell responses and antigen‐presenting cell function in HLA‐B27 transgenic rats with chronic colitis
Authors: Qian Bi‐Feng , Tonkonogy Susan L. , Hoentjen Frank , Dieleman Levinus A. , Sartor R. Balfour
Published: August 2005

HLA‐B27/β2 microglobulin transgenic (TG) rats spontaneously develop T‐cell‐mediated colitis when colonized with normal commensal bacteria, but remain disease‐free under germ‐free conditions. We investigated regulation of in vitro T‐cell responses to enteric bacterial components. Bacterial lysates prepared from the caecal contents of specific pathogen‐free (SPF) rats stimulated interferon‐γ (IFN‐γ) production by TG but not non‐TG mesenteric lymph node (MLN) cells. In contrast, essentially equivalent amounts of interleukin‐10 (IL‐10) were produced by TG and non‐TG cells. However, when cells from MLNs of non‐TG rats were cocultured with TG MLN cells, no suppression of IFN‐γ production was noted. Both non‐TG and TG antigen‐presenting cells (APC) pulsed with caecal bacterial lysate were able to induce IFN‐γ production by TG CD4+ cells, although non‐TG APC were more efficient than TG APC. Interestingly, the addition of exogenous IL‐10 inhibited non‐TG APC but not TG APC stimulation of IFN‐γ production by cocultured TG CD4+ lymphocytes. Conversely, in the presence of exogenous IFN‐γ, production of IL‐10 was significantly lower in the supernatants of TG compared to non‐TG APC cultures. We conclude that commensal luminal bacterial components induce exaggerated in vitro IFN‐γ responses in HLA‐B27 TG T cells, which may in turn inhibit the production of regulatory molecules, such as IL‐10. Alterations in the production of IFN‐γ, and in responses to this cytokine, as well as possible resistance of TG cells to suppressive regulation could together contribute to the development of chronic colitis in TG rats.
Extending the evaluation of a computer system used as a microswitch for word utterances of persons with multiple disabilities
Authors: Lancioni G. E. , O'Reilly M. F. , Singh N. N. , Sigafoos J. , Oliva D. , Montironi G. , Savino M. , Bosco A.
Published: August 2005

Background  Microswitches can be vital tools to help individuals with extensive multiple disabilities acquire control of environmental stimulation. This study was aimed at extending the evaluation of a computer system used as a microswitch for word utterances with three participants with multiple disabilities.

Method  Sets of 7 or 12 word utterances were used for the participants. The utterances were divided into three groups, which were exposed to intervention successively. During the intervention and a 2‐month post‐intervention check, the participants’ emission of the target utterances led the system to present favourite, matching stimuli (i.e. provided that it recognized the utterances).

Results  Intervention data showed that (1) the participants increased the frequencies of the target utterances and (2) the computer system recognized approximately 80% of those utterances. These findings were maintained at the post‐intervention check. An analysis of the levels of occurrence of individual utterances showed statistically significant differences among them, in line with the notions of preference and choice.

Conclusions  The computer system was useful as a microswitch to enable access to favourite stimuli. There is a need to improve the accuracy of the system with respect to its recognition of the participants’ utterances.
Adaptive functioning and behaviour problems in relation to level of education in children and adolescents with intellectual disability
Authors: De Bildt A. , Sytema S. , Kraijer D. , Sparrow S. , Minderaa R.
Published: August 2005

Background  The interrelationship between adaptive functioning, behaviour problems and level of special education was studied in 186 children with IQs ranging from 61 to 70. The objective was to increase the insight into the contribution of adaptive functioning and general and autistic behaviour problems to the level of education in children with intellectual disability (ID).

Methods  Children from two levels of special education in the Netherlands were compared with respect to adaptive functioning [Vineland Adaptive Behavior Scales (VABS)], general behaviour problems [Child Behavior Checklist (CBCL)] and autistic behaviour problems [Autism Behavior Checklist (ABC)]. The effect of behaviour problems on adaptive functioning, and the causal relationships between behaviour problems, adaptive functioning and level of education were investigated.

Results  Children in schools for mild learning problems had higher VABS scores, and lower CBCL and ABC scores. The ABC had a significant effect on the total age equivalent of the VABS in schools for severe learning problems, the CBCL in schools for mild learning problems. A direct effect of the ABC and CBCL total scores on the VABS age equivalent was found, together with a direct effect of the VABS age equivalent on level of education and therefore an indirect effect of ABC and CBCL on level of education.

Conclusions  In the children with the highest level of mild ID, adaptive functioning seems to be the most important factor that directly influences the level of education that a child attends. Autistic and general behaviour problems directly influence the level of adaptive functioning. Especially, autistic problems seem to have such a restrictive effect on the level of adaptive functioning that children do not reach the level of education that would be expected based on IQ. Clinical implications are discussed.
Blink rate in boys with fragile X syndrome: preliminary evidence for altered dopamine function
Authors: Roberts J. E. , Symons F. J. , Johnson A.‐M. , Hatton D. D. , Boccia M. L.
Published: August 2005

Background  Dopamine, a neurotransmitter involved in motor and cognitive functioning, can be non‐invasively measured via observation of spontaneous blink rates. Blink rates have been studied in a number of clinical conditions including schizophrenia, autism, Parkinsons, and attention deficit/hyperactivity disorder with results implicating either hyper or hypo dopaminergic states.

Methods  This study examined spontaneous blink rate in boys with fragile X syndrome (FXS). Blink rates of boys (4–8 years old) with FXS (n = 6) were compared with those of age‐matched typically developing boys (n = 6) during active and passive tasks. Blink rates (blinks per minute) for each task were compared between the two groups. Then, the relation between blink measures and core FXS‐related features [problem behaviours, arousal, fmr 1 protein (FMRP)] were examined within the group of boys with FXS.

Results  Blink rate in boys with FXS was significantly higher than typically developing boys during passive tasks. Within the FXS group, there were significant correlations between blink rate and problem behaviours and physiological arousal (i.e. heart activity) but not with FMRP.

Conclusions  Observed differences in spontaneous blink rate between boys with and without FXS and the relation between blink rate and physiological and behavioural measures in boys with FXS suggests that further work examining dopamine dysfunction as  a factor in the pathophysiology of FXS may be warranted.
Detecting past population bottlenecks using temporal genetic data
Authors: RAMAKRISHNAN UMA , HADLY ELIZABETH A. , MOUNTAIN JOANNA L.
Published: August 2005

Population bottlenecks wield a powerful influence on the evolution of species and populations by reducing the repertoire of responses available for stochastic environmental events. Although modern contractions of wild populations due to human‐related impacts have been documented globally, discerning historic bottlenecks for all but the most recent and severe events remains a serious challenge. Genetic samples dating to different points in time may provide a solution in some cases. We conducted serial coalescent simulations to assess the extent to which temporal genetic data are informative regarding population bottlenecks. These simulations demonstrated that the power to reject a constant population size hypothesis using both ancient and modern genetic data is almost always higher than that based solely on modern data. The difference in power between the modern and temporal DNA approaches depends significantly on effective population size and bottleneck intensity and less significantly on sample size. The temporal approach provides more power in cases of genetic recovery (via migration) from a bottleneck than in cases of demographic recovery (via population growth). Choice of genetic region is critical, as mutation rate heavily influences the extent to which temporal sampling yields novel information regarding the demographic history of populations.