bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene conversions are a common cause of von Willebrand disease
Authors: Gupta P. K. , Adamtziki E. , Budde U. , Jaiprakash M. , Kumar H. , Harbeck‐Seu A. , Kannan M. , Oyen F. , Obser T. , Wedekind I. , Saxena R. , Schneppenheim R.
Published: August 2005

von Willebrand disease (VWD), the most common inherited bleeding disorder, is very heterogeneous, both in its phenotype and genotype. One particular molecular mechanism of VWD is due to recombination events between the true gene and its pseudogene on chromosome 22. We assessed the frequency and extension of such events in 50 multi‐ethnic index patients with severe VWD type 3 and in five index patients with VWD type 2M Vicenza. One additional unclassified patient had been diagnosed with possible VWD in Russia solely on a clinical basis. Gene conversions, previously thought to be rare events, were identified in >10% of our study population: in six multi‐ethnic patients with severe VWD type 3, in one patient with VWD type 2M Vicenza and the Russian patient was finally diagnosed with VWD type 2B New York/Malmoe. Our results suggest a significant contribution of this particular molecular mechanism to the manifestation of VWD. The location of the gene conversions, their extension and their occurrence as homozygous, compound heterozygous or heterozygous mutations determines the resulting phenotype.
Primary mediastinal large B‐cell lymphoma: optimal therapy and prognostic factor analysis in 141 consecutive patients treated at memorial Sloan Kettering from 1980 to 1999
Authors: Hamlin Paul A. , Portlock Carol S. , Straus David J. , Noy Ariela , Singer Andrew , Horwitz Steven M. , OConnor Owen A. , Yahalom Joachim , Zelenetz Andrew D. , Moskowitz Craig H.
Published: August 2005

Primary mediastinal large B‐cell lymphoma (PMLBL) is a distinct clinicopathological entity with unclear prognostic factors and optimal treatment approach. To elucidate an optimal treatment and identify predictive factors, a retrospective analysis of 141 consecutive patients was undertaken. Patients received cyclophosphamide, hydroxydaunomycin, Oncovin, prednisone (CHOP)‐like therapy, the non‐Hodgkin lymphoma (NHL)‐15 regimen or upfront autologous stem cell transplantation (ASCT) on Institutional Review Board approved trials or according to the institutional guidelines. Evaluation included lactate dehydrogenase, International Prognostic Index (IPI) assessment, computed tomography scan and gallium imaging. With a median follow‐up of 10·9 years, event‐free survival (EFS) and overall survival (OS) was 50% and 66% respectively. EFS/OS for CHOP/CHOP‐like, NHL‐15 and upfront ASCT was 34/51%, 60/84% and 60/78% respectively. CHOP/CHOP‐like regimens had inferior EFS and OSversusNHL‐15 or upfront ASCT (P < 0·001). A total of 23% of patients received radiotherapy. Multivariate analysis revealed the following outcome predictors: for EFS, greater than or equal to two extranodal sites and initial therapy received (NHL‐15 or upfront ASCT); for OS, only initial therapy with NHL‐15. We conclude: (i) dose‐dense chemotherapy with NHL‐15 may be superior to CHOP for PMLBL; (ii) The impact of consolidative radiotherapy requires randomised controlled trials; (iii) The age‐adjusted IPI did not predict survival in this analysis; (iv) high‐dose chemotherapy/ASCT should be reserved for upfront anthracycline‐based therapy failure or in clinical trials for high‐risk patients.
Lineage‐specific engraftment and outcomes after T‐cell‐depleted peripheral blood stem cell transplant with Flu/Cy/TBI conditioning
Authors: Montero Aldemar , Savani Bipin N. , Kurlander Roger , Read Elizabeth J. , Leitman Susan F. , Childs Richard , Solomon Scott R. , John Barrett A.
Published: August 2005

Sixty patients with haematological malignancies received a myeloablative regimen of total body irradiation, cyclophosphamide and fludarabine followed by a T‐cell‐depleted peripheral blood stem cell transplant from a human leucocyte antigen identical sibling. To improve donor immune function, 1 × 107 CD3+ cells/kg were added‐back between d 45 and 100. T‐cell and myeloid chimaerism were monitored regularly to evaluate the effect of T‐cell chimaerism on outcome. The major factor affecting outcome was disease risk, with significantly lower relapse and higher survival in 29 standard risk (SR) patients compared with 31 patients at high risk (HR) for treatment failure (relapse 4·8 ± 5% vs. 59 ± 11%, P < 0·0001, and overall survival 93 ± 5% vs. 39 ± 10%, P < 0·0001, respectively). Donor myeloid chimaerism reached ≥95% within 14 d of transplant, but in the first several months, donor T‐cell chimaerism was frequently mixed. Full T‐cell chimaerism was significantly more frequent in HR vs. SR patients. Landmark analysis at days 30 and 90 in HR patients with mixed versus full T‐cell chimaerism, showed relapse probabilities of 50·5 ± 14% vs. 70 ± 16% (P = 0·62) and 34·4 ± 20% vs. 58·8 ± 15% (P = 0·32) respectively. Early full T‐cell engraftment correlated with development of severe acute graft‐versus‐host disease (GVHD). However, mixed T‐cell chimaerism was favourable for reducing GVHD, and did not affect relapse in this small series.
Comparative genomic hybridisation identifies two variants of smoldering multiple myeloma
Authors: Rosiñol Laura , Carrió Ana , Bladé Joan , Queralt Rosa , Aymerich Marta , Cibeira MaTeresa , Esteve Jordi , Rozman Maria , Campo Elías , Montserrat Emili
Published: August 2005

Two variants of smoldering multiple myeloma (SMM) have been recognised: (i) an evolving type, characterised by a progressive increase in the M‐protein size and short time to progression to overt multiple myeloma (MM) and (ii) a non‐evolving type, with a long‐lasting, stable M‐protein and longer time to progression. Comparative genomic hybridisation (CGH) analyses in both subtypes of SMM (seven evolving and eight non‐evolving SMM) were performed. Evolving SMM showed cytogenetic changes consistent with those found in de novo symptomatic MM (1q gains, chromosome 13 deletions) while the non‐evolving variant showed no 1q gains and deletions were uncommon.
Validation of questions on asthma and wheeze in farming and anthroposophic children
Authors: Üblagger E. , Schreuer M. , Eder W. , Von Mutius E. , Benz M. R. , Braun‐Fahrländer C. , Moeller A. , Brunekreef B. , Schram D. , Wickman M. , Swartz J. , Pershagen G. , Riedler J. ,   on behalf of the PARSIFAL study group
Published: August 2005

Background
In most epidemiological surveys the estimated prevalence of asthma is based on questionnaire responses, which may depend on the individual's perception as well as medical consulting habits in a given population. Therefore, measurement of bronchial hyper‐responsiveness as a key feature of asthma has been suggested as an objective parameter for asthma.

Objective
The aim of the present study was to validate questionnaire responses on asthma and wheeze against bronchial response to hypertonic saline (HS) (4.5%) in populations previously shown to have a lower prevalence of asthma and allergies: farmers' children and children from anthroposophic families.

Methods
Children whose parents had completed a written questionnaire in the cross‐sectional PARSIFAL‐study were drawn from the following four subgroups: ‘farm children’ (n=183), ‘farm reference children’ (n=173), ‘Steiner schoolchildren’ (n=243) and ‘Steiner reference children’ (n=179). Overall, 319 children with wheeze in the last 12 months and 459 children without wheeze in the last 12 months performed an HS challenge.

Results
Odds ratios, sensitivity, specificity, likelihood ratios and measures of association did not differ significantly between the four subgroups. The correlation between the bronchial response to HS and wheeze and asthma questions was moderate and similar for farm children, farm reference children, Steiner schoolchildren and Steiner reference children (κ for ‘wheeze’: 0.25, 0.33, 0.31, 0.35, respectively, P=0.754, κ for ‘doctor's diagnosis of asthma’: 0.33, 0.19, 0.33, 032, respectively, P=0.499).

Conclusion
The findings from this study suggest that the reliabilitiy of questionnaire responses on asthma and wheeze is comparable between farmers' children, children raised in families with anthroposophic lifestyle and their respective peers.
The effects of Anabaena spiroides (Cyanophyceae) exopolysaccharide on copper toxicity to Simocephalus serrulatus (Cladocera, Daphnidae)
Authors: NOGUEIRA PATRÍCIA F. M. , MELÃO MARIA DA G. G. , LOMBARDI ANA T. , VIEIRA ARMANDO A. H.
Published: August 2005

1. This work investigated the consumption of a microalgal (Anabaena spiroides) exopolysaccharide by the cladoceran Simocephalus serrulatus (Cladocera, Daphnidae) and its effect on copper toxicity.

2. Total organic carbon concentration was used to quantify the microalgal exopolysaccharide. Both copper‐complexed exopolysaccharides and copper‐free exopolysaccharides were taken up by S. serrulatus.

3. A reduction of free copper ions was obtained in the presence of A. spiroides exopolysaccharide. Copper toxicity (EC50) and zooplankton concentrations were inversely correlated to exopolysaccharide concentration in experimental media.

4. An increase of free copper ions in experimental media was obtained after exopolysaccharide consumption, suggesting that S. serrulatus excreted copper to the surrounding environment.
Genetic variation in populations of the endangered fish Ladigesocypris ghigii and its implications for conservation
Authors: MAMURIS ZISSIS , STOUMBOUDI MARIA TH. , STAMATIS COSTAS , BARBIERI ROBERTA , MOUTOU KATERINA A.
Published: August 2005

1. The genetic variation of the endangered freshwater fish Ladigesocypris ghigii, endemic to the island of Rhodes (Greece), was investigated for nine populations, originating from seven different stream systems and a reservoir, both at the mtDNA and nuclear level, in order to suggest conservation actions.

2. Both restriction fragment length polymorphism analysis of five segments of mitochondrial DNA (ND‐5/6, COI and 12S‐16S rRNA) amplified by polymerase chain reaction, and random amplified polymorphic DNA analysis, revealed extremely low levels of intra‐population polymorphism. It is highly likely that the low intra‐population variability is the result of successive bottleneck events evident in shrinkage and expansion of the populations year after year, which may have led to a complete loss of several genotypes and haplotypes, and an increased degree of inbreeding.

3. Inter‐population genetic structuring was high, with fixation of haplotypes within six of the nine populations and fixation of alleles within populations originating from different waterbodies. It is probable that all haplotypes and/or alleles found were initially represented in all populations. However, because of the long time of isolation coupled with successive bottleneck and subsequent genetic drift, common mtDNA haplotypes and alleles among the populations may have become rare or extinct through stochastic lineage loss.

4. Although nucleotide divergence among haplotypes was very shallow, half of the haplotypes recorded (three of six), resulted from nucleotide changes on the 12S–16S rRNA segments, which are the most conserved part of the mitochondrial genome. This fact may indicate that the observed genetic variation did not necessarily result only from the retention of ancestral polymorphism, but may have arisen through mutation and complete lineage sorting over a relatively small number of generations, once the populations had become isolated from one another.

5. Our data suggest that two of the L. ghigii populations may be on independent evolutionary trajectories. Considering that each population appears so far well adapted within each site, all populations should be managed and conserved separately.
Survival and development of five species of cyclopoid copepods in relation to food supply: experiments with algal food in a flow‐through system
Authors: HOPP ULRICH , Maier GERHARD
Published: August 2005

1. Cyclops spp. generally develop and grow during favourable food conditions in spring and undergo a diapause in summer, while Acanthocyclops robustus, Mesocyclops leuckarti and Thermocyclops crassus develop and grow in summer when they face poorer food conditions and more competition from Cladocera. Since nauplii are the bottleneck in copepod development, we tested the hypothesis that Cyclops abyssorum and C. vicinus nauplii have higher food requirements for survival and development than the nauplii of A. robustus, M. leuckarti and T. crassus. We also tested survivorship and development from hatching to adulthood.

2. Survivorship and development of the copepods was studied in a flow‐through system using five concentrations of the phytoflagellate Chlamydomonas reinhardtii in the range from 1 × 104 to 4.5 × 105 cells mL−1 (approximately 0.5–22.5 mg C L−1).

3. Nauplii of both species of Cyclops died at intermediate to low (C. abyssorum) and low (C. vicinus) food concentrations, while nauplii of A. robustus, M. leuckarti and T. crassus survived at all concentrations.

4. The negative effects of low food concentration were also reflected in development. In C. abyssorum and C. vicinus, development duration increased at low food concentration while development was much less affected in A. robustus and T. crassus. Mesocyclops leuckarti was intermediate between Cyclops spp. and A. robustus/T. crassus, with an increase in development duration at the lowest food concentration.

5. Our results support the hypothesis that summer diapause in Cyclops spp. has developed as a strategy to avoid a food bottleneck for nauplii.
Zooplankton of turbid and hydrologically dynamic prairie rivers
Authors: THORP JAMES H. , MANTOVANI SARA
Published: August 2005

1. Compared with rivers in more humid, forested ecoregions of eastern and midwestern U.S.A., rivers in semi‐arid grassland of the U.S. Great Plains tend to be relatively shallow, more variable in discharge, and characterised by high suspended sediment loads. Although critical life stages of fish in prairie rivers probably depend at least partially on zooplanktonic food, data on community and distributional patterns of potamoplankton in these widespread ecosystems are almost entirely absent.

2. We examined summer zooplankton distribution in five prairie rivers (Arkansas, Kansas, Platte, Elkhorn, and Niobrara Rivers) spread over six degrees of latitude during 2003–2004. We compared our results from 126 samples with previously collected data from the Ohio and St Lawrence Rivers in forested ecoregions and correlated differences with abiotic environmental conditions.

3. The importance of hydrological retention zones to stream biota has been recently demonstrated for rivers with quasi‐permanent islands and slackwater regions, but the importance of slackwaters formed by ephemeral sandbar islands in prairie rivers is unknown. We evaluated the role of hydrological retention for planktonic rotifers, cladocera, and copepods in the Kansas River during the summer of 2004.

4. Zooplankton assemblages were extremely similar among prairie rivers (Sorensen Dissimilarity Index: mean = 0.07) but moderately disparate for comparisons of prairie versus forested‐basin rivers (mean = 0.50).

5. Total zooplankton densities in prairie rivers (approximately 81 L−1) were intermediate between the Ohio (approximately 92 L−1) and St Lawrence Rivers (approximately 43 L−1), but relative abundances were significantly different. Rotifers represented >99% of zooplankton individuals in grassland rivers, but only approximately 37–68% in other rivers. Rotifer species richness was lower in prairie rivers, but relative abundances of common genera were much less skewed compared with eastern rivers where Polyarthra dominated rotifer assemblages (41–73%).

6. For comparisons among rivers, rotifers were significantly more abundant in turbid rivers, while microcrustaceans were less dense. However, for comparisons within the Kansas River over time, rotifer densities were inversely related to turbidity. We hypothesise that rotifers indirectly benefit from river turbidity because their food competitors (cladocera) and predators (e.g. cyclopoid copepods and visually feeding fish) are relatively more susceptible to suspended sediments.

7. Crustacean densities were positively related to the degree of hydrological retention (negatively to current velocities) throughout the study, but rotifer densities were significantly depressed by current velocities only when river discharge was high, making slackwaters that much more valuable. Ephemeral sandbars may not provide sufficient hydrological retention in time and space to sustain viable crustacean populations, but they are adequate to help sustain growth of rotifer populations.
Combined effects of water column nitrate enrichment, sediment type and irradiance on growth and foliar nutrient concentrations of Potamogeton alpinus
Authors: BOEDELTJE GER , SMOLDERS ALFONS J. P. , ROELOFS JAN G. M.
Published: August 2005

1. High water column NO3− concentrations, low light availability and anoxic, muddy sediments are hypothesised to be key factors hampering growth of rooted submerged plants in shallow, eutrophic fresh water systems. In this study, the relative roles and interacting effects of these potential stressors on survival, growth, allocation of biomass and foliar nutrient concentrations of Potamogeton alpinus were determined in a mesocosm experiment using contrasting values of each factor (500 versus 0 μmol L−1 NO3−; low irradiance, corresponding to the eutrophic environment, versus ambient irradiance; and muddy versus sandy sediment).

2. Low irradiance, high NO3− and sandy sediment led to reduced growth. In a muddy sediment, plants had lower root : shoot ratios than in a sandy sediment.

3. Growth at high NO3− and on the sandy sediment resulted in lower foliar N and C concentrations than in the contrasting treatments. The C : N ratio was higher at high NO3− and on the sandy sediment. Foliar P was higher on the muddy than on the sandy sediment but was not affected by irradiance or NO3−. The N : P ratio was lowest at high NO3− on the sandy sediment.

4. Total foliar free amino acid concentration was lowest on sand, low irradiance and high NO3−. Total free amino acid concentration and growth were not correlated.

5. Turbidity and ortho‐PO43− concentration of the water layer were lower at high water column NO3− indicating that the growth reduction was not associated with increased algal growth but that physiological mechanisms were involved.

6. We conclude that high water column NO3− concentrations can significantly reduce the growth of ammonium preferring rooted submerged species such as P. alpinus, particularly on sediments with a relatively low nutrient availability. Further experiments are needed to assess potential negative effects on other species and to further elucidate the underlying physiological mechanisms.
Monte‐Carlo Bayesian look‐ahead inversion of walkaway vertical seismic profiles
Authors: Malinverno Alberto , Leaney W. Scott
Published: August 2005

We describe a method to invert a walkaway vertical seismic profile (VSP) and predict elastic properties (P‐wave velocity, S‐wave velocity and density) in a layered model looking ahead of the deepest receiver. Starting from Bayes's rule, we define a posterior distribution of layered models that combines prior information (on the overall variability of and correlations among the elastic properties observed in well logs) with information provided by the VSP data. This posterior distribution of layered models is sampled by a Monte‐Carlo method. The sampled layered models agree with prior information and fit the VSP data, and their overall variability defines the uncertainty in the predicted elastic properties. We apply this technique first to a zero‐offset VSP data set, and show that uncertainty in the long‐wavelength P‐wave velocity structure results in a sizable uncertainty in the predicted elastic properties. We then use walkaway VSP data, which contain information on the long‐wavelength P‐wave velocity (in the reflection moveout) and on S‐wave velocity and density contrasts (in the change of reflectivity with offset). The uncertainty of the look‐ahead prediction is considerably decreased compared with the zero‐offset VSP, and the predicted elastic properties are in good agreement with well‐log measurements.
Quasi‐2D hybrid joint inversion of seismic and geoelectric data
Authors: De Nardis R. , Cardarelli E. , Dobroka M.
Published: August 2005

Many joint inversion schemes use 1D forward modelling in the integrated interpretation of various geophysical data. In extending the joint inversion approach to the investigation of 2D structures, the discretization of the model parameters and the appropriate choice of the forward‐modelling procedure play a very important role. In this paper, a hybrid seismic–geoelectric joint inversion method is proposed for the investigation of 2D near‐surface geological structures. The electric and seismic models are coupled together through the use of common boundaries between the adjacent layers. Assuming a 2D model composed of homogeneous layers with curved boundaries, a fast ray‐tracing algorithm is used for the calculation of refraction seismic traveltime data. In the geoelectric forward modelling, a locally 1D approximation is used. The boundary surfaces are written in the form of series expansion; the inversion algorithms are formulated for the expansion coefficients and the petrophysical parameters as unknowns. Two versions of the inversion method are proposed: in versions A and B, interval‐wise constant functions and Chebyshev polynomials are, respectively, used as basis functions of the series expansion. The versions are tested by means of synthetic and in situ measured data. The tests show that both methods are stable and accurate.
Zero‐offset P–S energy in horizontally layered media
Authors: Artola Fredy A.V. , Leiderman Ricardo , Fontoura Sergio A.B.
Published: August 2005

The existence of non‐zero reflectivity for zero‐offset PS waves in horizontally layered media is discussed. Field measurements have suggested the occurrence of this phenomenon. We show that, in some cases, if anisotropy is considered in the problem, this reflectivity can be predicted. By using an approximated formulation to determine the coefficient of reflection in arbitrarily anisotropic media, it is clear that, for some elastic arrangements of the subsurface, reflected energy is associated with the converted wave resulting from normal P‐wave incidence.
Dry‐matter yields and crude protein and rumen‐degradable protein concentrations of three Arachis pintoi ecotypes at different stages of regrowth in the humid tropics
Authors: Villarreal M. , Cochran R. C. , Villalobos L. , Roja‐Bourrillón A. , Rodríguez R. , Wickersham T. A.
Published: August 2005

Well‐established stands of three ecotypes of Arachis pintoi (CIAT 17434, 18744 and 18748) were harvested from replicated plots (three blocks, each containing three plots for each ecotype) during the two dominant seasons (dry and wet) of the low altitude, humid tropics of Costa Rica. Each plot was further divided into six subplots so that, within each season, samples corresponding to 4, 6, 8, 10, 12 or 14 weeks of regrowth could be collected. For each harvest, dry matter (DM) yield of the leaf, stem and whole plant, and the leaf:stem ratio, were recorded. Samples of the whole plant were analysed for crude protein (CP), rumen‐degradable (RDP) and rumen‐undegradable protein (RUP) concentrations. DM yield of the leaf, stem and whole plant increased with advancing period of regrowth but the effects of period of regrowth varied somewhat among ecotypes and across seasons. Generally, DM yield was greater during the wet than during the dry season. The greatest difference between ecotypes for stem and total DM yields was evident during the dry season. In general, DM contents were low in the whole plant, leaf and stem samples (<220 g kg−1) and increased with increasing period of regrowth. Increases in leaf:stem ratio were most dramatic during the dry season with greater periods of regrowth, although the ratio was fairly constant during the wet season. Whole‐plant CP concentration was relatively high after short periods of regrowth (up to 279 g kg−1 DM) but declined with longer periods of regrowth; the relative decline was much greater during the dry season. The RDP concentration was relatively constant during the wet season (mean 115 g kg−1 DM), but declined with longer periods of regrowth during the dry season (range 194–111 g kg−1 DM). In general, the concentrations of RDP, on a CP basis, were greater during the dry season and ranged from 590 to 700 g kg−1 CP. Season, ecotype and period of regrowth all exerted an effect on RUP concentrations.
The influence of grass and maize silage quality on apparent diet digestibility, metabolizable energy concentration and intake of finishing beef cattle
Authors: Kirkland R. M. , Steen R. W. J. , Gordon F. J. , Keady T. W. J.
Published: August 2005

The effects of offering a range of grass silages and mixtures of grass and maize silages on the intake of beef cattle were studied. Four grass silages (GS1, GS2, GS3 and GS4) were used. Grass silage 1 was ensiled from a second regrowth in mid‐late September and treated with an inoculant additive. Grass silages 2, 3 and 4 were ensiled, without additive, from a primary regrowth harvested in early July, late May and mid‐June respectively. Wilting periods were 8, 30, 36 and 36 h for GS1, GS2, GS3 and GS4 respectively. Grass silages 1, 2 and 3 were precision chopped and ensiled in bunker silos, while GS4 was ensiled in round bales. The DM content (g kg−1) and starch concentration (g kg−1 DM) of the three maize silages (MS1, MS2 and MS3) used were 256 and 128, 256 and 184, and 402 and 328 for MS1, MS2 and MS3 respectively. Seventy‐two Charolais and Limousin cross‐bred steers were used in a changeover design with two 4‐week periods. The study consisted of sixteen treatments incorporating the four grass silages fed alone and with the three maize silages arranged as a 4 × 4 factorial design. The grass silage and maize silage mixtures were offered in a ratio of 0·60:0·40 (DM basis) once daily using individual Calan gates. All silages were offered ad libitum with 3 kg per head per day of a concentrate supplement. Dry matter and metabolizable energy (ME) intakes were highest with diets based on grass silage GS4 compared with diets containing the other grass silages. Metabolizable energy intakes of diets containing no maize silage, and those based on MS1 and MS2, were similar (P > 0·05) but lower than that of diets containing MS3. Only limited increases were found in DM and ME intakes with the inclusion of maize silage in grass silage‐based diets while offering high‐quality grass silage (assessed in terms of DM content, and fibre and N concentrations) promoted high voluntary intakes.
Species composition of ryegrass (Lolium perenne) and tall fescue (Festuca arundinacea) mixtures using various combinations of n‐alkanes
Authors: Cortes C. , Damasceno J. C. , Bechet G. , Prache S.
Published: August 2005

This study was conducted to evaluate the reliability of the n‐alkane technique for estimating the species composition of Lolium perenne (ryegrass, L) and Festuca arundinacea (tall fescue, F) mixtures. Samples of L and F were collected in May (period 1) and June 2003 (period 2) on mono‐specific swards that were maintained at a height of 9 cm. Seven sets of mixtures containing controlled proportions of L and F were then prepared: 1·00:0, 0·80:0·20, 0·60:0·40, 0·50:0·50, 0·40:0·60, 0·20:0·80 and 0:1·00 of L:F, respectively, in the mixture. The proportion of each species in the mixtures was estimated from measured n‐alkane concentrations, and then compared with the actual known proportion. Various n‐alkane combinations were tested and compared to establish which combination gave the best estimate. Total n‐alkane concentrations, and especially C29‐ and C31‐alkane concentrations, were higher in period 1 than in period 2 for both species. The best n‐alkane combination varied between periods, as did the effectiveness of C29‐alkane in discriminating between L and F. The species composition of the mixtures was satisfactorily estimated for the majority of n‐alkane combinations, providing the combination included n‐alkanes with contrasting profiles between both species. A systematic overestimation of the proportion of ryegrass was observed for the 0·50:0·50 mixture.
Apparent digestibility and nitrogen utilization of diets based on maize silage harvested at three stages of maturity and fed to steers
Authors: Browne E. M. , Juniper D. T. , Bryant M. J. , Beever D. E.
Published: August 2005

Advancing maize crop maturity is associated with changes in ear‐to‐stover ratio which may have consequences for the digestibility of the ensiled crop. The apparent digestibility and nitrogen retention of three diets (Early, Mid and Late) containing maize silages made from maize of advancing harvest date [dry matter (DM) contents of the maize silages were 273, 314 and 367 g kg−1 for the silages in the Early, Mid and Late diets respectively], together with a protein supplement offered in sufficient quantities to make the diets isonitrogenous, were measured in six Holstein–Friesian steers in an incomplete Latin square design with four periods. Dry‐matter intake of maize silage tended to be least for the Early diet and greatest for the Medium diet (P = 0·182). Apparent digestibility of DM and organic matter did not differ between diets. Apparent digestibility of energy was lowest in the Late diet (P = 0·057) and the metabolizable energy concentrations of the three silages were calculated as 11·0, 11·1 and 10·6 MJ kg−1 DM for the Early, Medium and Late diets respectively (P = 0·068). No differences were detected between diets in starch digestibility but the number of undamaged grains present in the faeces of animals fed the Late diet was significantly higher than with the Early and Mid diets (P = 0·006). The apparent digestibility of neutral‐detergent fibre of the diets reduced significantly as silage DM content increased (P = 0·012) with a similar trend for the apparent digestibility of acid‐detergent fibre (P = 0·078). Apparent digestibility of nitrogen (N) was similar for the Early and Mid diets, both being greater than the Late diet (P = 0·035). Nitrogen retention did not differ between diets. It was concluded that delaying harvest until the DM content is above 300 g kg−1 can negatively affect the nutritive value of maize silage in the UK.
Potassium cycling and losses in grassland systems: a review
Authors: Kayser M. , Isselstein J.
Published: August 2005

Cycling of potassium in grassland systems has received relatively little attention in research and practice in recent years. Balanced nutrient systems require consideration of nutrients other than nitrogen (N). Potassium (K) is needed in large amounts and is closely related to N nutrition. In intensive dairy farming, surpluses of K arise from the input of concentrates and fertilizer and are returned to the grassland and may lead to increasing K content in the soil. Organic farming, on the other hand, is characterized by limitations in input of nutrient sources and quantities. Leaching of K from grassland is usually low, but high levels of available soil K, high K input from fertilizer or at urine patches lead to increasing losses. High K inputs have a negative influence on Mg and Ca uptake by plants and can cause accelerated leaching of these cations. High levels of K have been associated with inducing nutrition‐related dairy cow health problems such as milk fever (hypocalcaemia) and grass tetany (hypomagnesaemia). This review gives an overview of the cycling of potassium and related cations in grassland systems especially with regard to leaching losses and identifies limitations to knowledge.
Assessment of regional variation in climate on the management of dairy cow systems in Ireland using a simulation model
Authors: Fitzgerald J. B. , Brereton A. J. , Holden N. M.
Published: August 2005

A dairy system simulator, Dairy_sim, was designed to assess the interactions between climate and management in spring‐calving milk production systems based on the grazing of grass pastures. The simulator comprises three main components: a grass herbage growth model, an intake and grazing behaviour model, and a nutrient demand model. The simulator was initially parameterized using the Irish National Dairy Blueprint. Sensitivity analysis indicated that the simulator was most sensitive to stocking rate, milk output per cow and nitrogen fertilizer inputs, but less sensitive to other variables. Field data from four grazing systems were used to test the simulator and it was concluded that Dairy_sim was suitable for evaluating the interaction of climate and management for rotational grazing dairy systems based on perennial ryegrass pastures with Friesian cows. The simulator, Dairy_sim, was then used to evaluate the effects of the regional climates of Ireland on system management. The results indicated that, between regions, herbage production at the same input of nitrogen may vary proportionally by 0·10 and that the length of the grazing season may vary by 0·25. It was concluded that the simulator could be a useful tool for developing region‐specific dairy production blueprints.
Effects of grass pasture and concentrate‐based feeding systems for spring‐calving dairy cows in early spring on performance during lactation
Authors: Kennedy E. , O'Donovan M. , Murphy J.‐P. , Delaby L. , O'Mara F.
Published: August 2005

The effect of offering a total mixed ration of silage and concentrate (proportionately 0·44 silage) system [indoor feeding system (IF)] was compared with grazing at a high daily herbage allowance with a low level of concentrate supplementation [early grazing system (EG)] in early spring on the performance of spring‐calving dairy cows in Ireland. Sixty‐four spring‐calving Holstein–Friesian dairy cows (mean calving date, 2 February) were allocated to one of two systems between 16 February and 4 April 2004. An equal number of primiparous and multiparous cows were assigned to each system. The dairy cows on the IF system were housed for a 7‐week period and offered a diet of 10·9 kg DM cow−1 d−1 (s.d. 2·3) of concentrate, the remainder of the diet was 8·6 kg DM cow−1 d−1 (s.d. 1·9) of grass silage. The dairy cows on the EG system were offered a mean daily herbage allowance of 15·1 kg DM cow−1 d−1 (s.d. 3·7) and were supplemented with 3·0 kg DM cow−1 d−1 (s.d. 1·0) of concentrate. There was no difference in milk yield between the two systems but the cows in the EG system had a higher milk protein concentration (2·9 g kg−1) and a higher milk protein yield than in the IF system. Milk fat concentration was higher for cows in the IF than EG system (3·0 g kg−1). There was no difference in total daily dry‐matter intake between the systems, measured in week 6 of the study. Mean live weight of the cows in the IF system was greater than in the EG system. The results of the study suggest that a slightly greater performance can be achieved by a system offering a high daily herbage allowance to spring‐calving dairy cows in early lactation compared with a system offering a total mixed ration containing a high proportion of concentrate with grass silage.
Chemokine control of lymphocyte trafficking: a general overview
Authors: Stein Jens V. , Nombela‐Arrieta César
Published: August 2005

Chemokines are a large family of small, generally secreted polypeptides which guide lymphocyte movement throughout the body by controlling integrin avidity and inducing migration. Here, we look at recent, exciting findings on chemokine function throughout lymphocyte development and co‐ordinated T and B cell migration during immune responses. Finally, we will review data on the regional control of immunity by tissue‐specific chemokine receptors on effector/memory lymphocytes.
Expression of human pim family genes is selectively up‐regulated by cytokines promoting T helper type 1, but not T helper type 2, cell differentiation
Authors: Aho Teija L. T. , Lund Riikka J. , Ylikoski Emmi K. , Matikainen Sampsa , Lahesmaa Riitta , Koskinen Päivi J.
Published: August 2005

Cytokines are the most important inducers of T helper (Th) cell differentiation. Interleukin‐12 (IL‐12) and interferon‐α (IFN‐α) are responsible for human Th1‐cell differentiation, while IL‐4 is the critical cytokine promoting Th2‐cell development. These two subsets of cells co‐ordinate immunological responses to pathogens as well as autoimmune or allergic reactions. The pim family of proto‐oncogenes encodes serine/threonine‐specific kinases involved in cytokine‐mediated signalling pathways in haematopoietic cells. Here we demonstrate that expression of pim‐1 and pim‐2 mRNAs is selectively up‐ or down‐regulated in human cord‐blood‐derived CD4+ cells freshly induced to polarize towards Th1 or Th2 cells, respectively, whereas their expression is inhibited in both cell types by the immunosuppressive transforming growth factor β (TGF‐β). Moreover, the Th1‐specific cytokines IL‐12 and IFN‐α, but not the Th2‐specific cytokine IL‐4, transiently up‐regulate pim‐1 and pim‐2 mRNA expression in human peripheral blood T cells and natural killer cells. In addition, the Pim‐1 protein levels are strongly up‐regulated by Th1‐specific cytokines in all of these cell types. Taken together, our results suggest that pim genes and their protein products are involved in the early differentiation process of T helper cells.
Identification of the VH genes encoding xenoantibodies in non‐immunosuppressed rhesus monkeys
Authors: Kleihauer Annette , Gregory Clare R. , Borie Dominic C. , Kyles Andrew E. , Shulkin Irina , Patanwala Insiyyah , Zahorsky‐Reeves Joanne , Starnes Vaughn A. , Mullen Yoko , Todorov Ivan T. , Kearns‐Jonker Mary
Published: August 2005

The major immunological barrier that prevents the use of wild‐type pig xenografts as an alternative source of organs for human xenotransplantation is antibody‐mediated rejection. In this study, we identify the immunoglobulin variable region heavy (IgVH) chain genes encoding xenoantibodies to porcine heart and fetal porcine islet xenografts in non‐immunosuppressed rhesus monkeys. We sought to compare the IgVH genes encoding xenoantibodies to porcine islets and solid organ xenografts. The immunoglobulin M (IgM) and IgG xenoantibody response was analysed by enzyme‐linked immunosorbent assay and cDNA libraries from peripheral blood lymphocytes were prepared and sequenced. The relative frequency of IgVH gene usage was established by colony filter hybridization. Induced xenoantibodies were encoded by the IGHV3‐11 germline progenitor, the same germline gene that encodes xenoantibodies in humans mounting active xenoantibody responses. The immune response to pig xenografts presented as solid organs or isolated cells is mediated by identical IgVH genes in rhesus monkeys. These animals represent a clinically relevant model to identify the immunological basis of pig‐to‐human xenograft rejection.
Skin‐derived dendritic cells acquire and degrade the scrapie agent following in vitro exposure
Authors: Mohan Joanne , Hopkins John , Mabbott Neil A.
Published: August 2005

The accumulation of the scrapie agent in lymphoid tissues following inoculation via the skin is critical for efficient neuroinvasion, but how the agent is initially transported from the skin to the draining lymph node is not known. Langerhans cells (LCs) are specialized antigen‐presenting cells that continually sample their microenvironment within the epidermis and transport captured antigens to draining lymph nodes. We considered LCs probable candidates to acquire and transport the scrapie agent after inoculation via the skin. XS106 cells are dendritic cells (DCs) isolated from mouse epidermis with characteristics of mature LC cells. To investigate the potential interaction of LCs with the scrapie agent XS106 cells were exposed to the scrapie agent in vitro. We show that XS106 cells rapidly acquire the scrapie agent following in vitro exposure. In addition, XS106 cells partially degrade the scrapie agent following extended cultivation. These data suggest that LCs might acquire and degrade the scrapie agent after inoculation via the skin, but data from additional experiments demonstrate that this ability could be lost in the presence of lipopolysaccharide or other immunostimulatory molecules. Our studies also imply that LCs would not undergo maturation following uptake of the scrapie agent in the skin, as the expression of surface antigens associated with LC maturation were unaltered following exposure. In conclusion, although LCs or DCs have the potential to acquire the scrapie agent within the epidermis our data suggest it is unlikely that they become activated and stimulated to transport the agent to the draining lymph node.
Circulating and thymic CD4+ CD25+ T regulatory cells in myasthenia gravis: effect of immunosuppressive treatment
Authors: Fattorossi Andrea , Battaglia Alessandra , Buzzonetti Alexia , Ciaraffa Francesca , Scambia Giovanni , Evoli Amelia
Published: August 2005

Accumulating evidence indicates an immunosuppressive role of the thymus‐derived CD4+ T‐cell population constitutively expressing high level of CD25, T regulatory (Treg) cells, in autoimmune diseases. Here we show that the number of Treg cells in the blood is significantly lower in untreated myasthenia gravis patients than in age‐matched healthy subjects, whereas it is normal or elevated in patients on immunosuppressive therapy (prednisone frequently associated with azathioprine). Therapeutic thymectomy (Tx) for either the thymoma or non‐neoplastic thymic alterations that are often associated with myasthenia gravis provided unique material for studying intrathymic Treg cells and correlating them with their peripheral counterparts. We observed that Tx prevents the increase of Treg cells in the circulation that follows immunosuppressive therapy (particularly evident if the thymus is not neoplastic), indicating that the thymus contributes to Treg‐cell normalization. However, thymic Treg cells are not modulated by immunosuppressive therapy and even in thymectomized patients Treg‐cell numbers in the blood eventually recover. The present findings suggest that a deficiency in Treg cells favours the development of myasthenia gravis and that their normalization is an important clinical benefit of immunosuppressive therapy. Treg normalization appears to be largely thymus independent and possibly reflects the reported capacity of corticosteroids to promote Treg‐cell development.
Effects of integrated or segregated sport participation on the physical self for adolescents with intellectual disabilities
Authors: Ninot G. , Bilard J. , Delignières D.
Published: August 2005

Background  The purpose was to examine the effects of the type of athletic programme (integrated vs. segregated) on the athletic domain of perceived competence and on general self‐worth.

Methods  Participants were 32 adolescent females with intellectual disabilities (ID), divided equally into four groups: (1) segregated swimming; (2) integrated swimming; (3) adapted physical activity; and (4) sedentary. The experimental treatment was 32 months long; for sport groups, this involved 2 h of training each week and 12 competitive meets. The Harter Self‐Perception Profile for Children 11 times was administrated to determine changes in perceived physical competence and general self‐worth.

Results  Results indicated (1) no change in perceived general self‐worth for the four groups; (2) significantly lower perceived athletic competence only for the integrated swimming group, despite the increase in athletic performance.

Conclusions  The integrated sport participation for adolescents with ID placed in segregated school is useful but needs to be well controlled by professional in physical education.
Preschool children with intellectual disability: syndrome specificity, behaviour problems, and maternal well‐being
Authors: Eisenhower A. S. , Baker B. L. , Blacher J.
Published: August 2005

Background  Children with intellectual disability (ID) are at heightened risk for behaviour problems and diagnosed mental disorder. Likewise, mothers of children with ID are more stressed than mothers of typically developing children. Research on behavioural phenotypes suggests that different syndromes of ID may be associated with distinct child behavioural risks and maternal well‐being risks. In the present study, maternal reports of child behaviour problems and maternal well‐being were examined for syndrome‐specific differences.

Methods  The present authors studied the early manifestation and continuity of syndrome‐specific behaviour problems in 215 preschool children belonging to 5 groups (typically developing, undifferentiated developmental delays, Down syndrome, autism, cerebral palsy) as well as the relation of syndrome group to maternal well‐being.

Results  At age 3, children with autism and cerebral palsy showed the highest levels of behaviour problems, and children with Down syndrome and typically developing children showed the lowest levels. Mothers of children with autism reported more parenting stress than all other groups. These syndrome‐specific patterns of behaviour and maternal stress were stable across ages 3, 4 and 5 years, except for relative increases in behaviour problems and maternal stress in the Down syndrome and cerebral palsy groups. Child syndrome contributed to maternal stress even after accounting for differences in behaviour problems and cognitive level.

Conclusions  These results, although based on small syndrome groups, suggest that phenotypic expressions of behaviour problems are manifested as early as age 3. These behavioural differences were paralleled by differences in maternal stress, such that mothers of children with autism are at elevated risk for high stress. In addition, there appear to be other unexamined characteristics of these syndromes, beyond behaviour problems, which also contribute to maternal stress.
Ice age cloning – comparison of the Quaternary evolutionary histories of sexual and clonal forms of spiny loaches (Cobitis; Teleostei) using the analysis of mitochondrial DNA variation
Authors: JANKO K. , CULLING M. A. , RÁB P. , KOTLÍK P.
Published: August 2005

Recent advances in population history reconstruction offered a powerful tool for comparisons of the abilities of sexual and clonal forms to respond to Quaternary climatic oscillations, ultimately leading to inferences about the advantages and disadvantages of a given mode of reproduction. We reconstructed the Quaternary historical biogeography of the sexual parental species and clonal hybrid lineages within the Europe‐wide hybrid complex of Cobitis spiny loaches. Cobitis elongatoides and Cobitis taenia recolonizing Europe from separated refuges met in central Europe and the Pontic region giving rise to hybrid lineages during the Holocene. Cobitis elongatoides due to its long‐term reproductive contact with the remaining parental species of the complex — C. tanaitica and C. spec. — gave rise to two clonal hybrid lineages probably during the last interglacial or even earlier, which survived the Würmian glaciation with C. elongatoides. These lineages followed C. elongatoides postglacial expansion and probably decreased its dispersal rate. Our data indicate the frequent origins of asexuality irrespective of the parental populations involved and the comparable dispersal potential of diploid and triploid lineages.