bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐dose idarubicin and busulphan as conditioning to autologous stem cell transplantation in adult patients with acute myeloid leukaemia
Authors: Ferrara Felicetto , Palmieri Salvatore , Simone Mariacarla De , Sagristani Marco , Viola Assunta , Pocali Barbara , Fasanaro Alfredo , Mele Giuseppina 
Published: December 2004

SummaryBetween 30 and 50% of patients with acute myeloid leukaemia (AML) relapse after autologous stem cell transplantation (ASCT). One possibility of reducing the relapse rate could be the adoption of conditioning regimens specifically designed for AML. We report treatment results achieved with a new conditioning for ASCT, based on high‐dose idarubicin (IDA) plus oral busulphan. Patients (n = 40) were conditioned with a regimen consisting of 3 d continuous intravenous infusion IDA at 20 mg/m2, followed by 4 d conventional dose oral busulphan. Unpurged peripheral blood stem cells were used in all cases. All patients had non‐M3‐AML and were in first complete remission (CR). The median number of CD34+ cells infused was 6·9 × 106/l (2·6–24). No case of transplant‐related mortality occurred. In all cases, left ventricular ejection fraction remained unmodified after ASCT. Thirty‐three of 40 patients (82%) had grade 3–4 mucositis requiring total parenteral nutrition in all cases. After a median follow up for surviving patients of 32 months from ASCT, 30 patients (75%) are alive and 26 (65%) are in continuous CR. Our data show that a conditioning regimen based on high‐dose IDA plus busulphan results in an encouraging reduction of the relapse rate after ASCT in AML.
Thermogenesis and respiration of inflorescences of the dead horse arum Helicodiceros muscivorus, a pseudo‐thermoregulatory aroid associated with fly pollination
Authors: Seymour R. S. , Gibernau M. , Ito K. 
Published: December 2004

Summary

In central Corsica, Helicodiceros muscivorus (Schott ex. K. Koch) produces a protogynous inflorescence that resembles the anal area of a dead mammal and produces a foetid scent during the few hours after sunrise. Flies enter the floral chamber, pollinate the female florets and become trapped until the next morning, when pollen is shed from the male florets and the flies are released.
The exposed appendix exhibits a strong, unimodal episode of thermogenesis associated with scent production, reaching a maximum of 30 °C at 15 °C ambient temperature. The male florets in the floral chamber are highly thermogenic throughout the second night and generally maintain stable floret temperatures of about 24 °C at ambient temperatures down to 13 °C.
Maximum respiration rates of the appendix (0·45 µmol CO2 s−1 g−1) and the male florets (0·82 µmol s−1 g−1) may be the highest recorded for plant tissue.
Thermogenesis of the appendix does not depend on ambient temperature, but that of the male florets increases with decreasing ambient temperature in most cases. However, the pattern of heat production by the males appears related more to time than to ambient temperature, hence the term ‘pseudo‐thermoregulation’.
The behaviour and thoracic temperatures of flies emerging from captivity suggests that male floral warming does not enhance their activity.
Astroturf seed traps for studying hydrochory
Authors: Wolters M. , Geertsema J. , Chang E. R. , Veeneklaas R. M. , Carey P. D. , Bakker J. P. 
Published: December 2004

Summary

Astroturf mats can effectively trap diaspores dispersed by tidal water.
Within four tidal inundations, up to 745 propagules per m2 and between three and eight different species per astroturf mat were trapped. Overall, 15 different species were collected on the astroturf mats, 10 of which were also present in the local vegetation. The other five species must have come from further away, making the method also suitable for studying long‐distance dispersal.
The seed‐retaining ability of the astroturf did not differ significantly for species with different seed characteristics.
The method will be useful for assessing actual seed dispersal at specific sites and over specific periods of time, and has particular relevance in predicting and evaluating the success of ecological restoration projects.
Identification and characterization of a novel Dvl‐binding protein that suppresses Wnt signalling pathway
Authors: Oshita Akihiko , Kishida Shosei , Kobayashi Hiroki , Michiue Tatsuo , Asahara Toshimasa , Asashima Makoto , Kikuchi Akira 
Published: December 2004

AbstractBackground:   Dvl is a cytoplasmic protein to regulate the stability of β‐catenin in the Wnt signalling pathway. However, the molecular mechanism by which Dvl regulates the Wnt signalling pathway is not fully understood.Results:   We identified a novel protein that binds to Dvl and named it Daple. Daple consisted of 2009 amino acids with a high frequency of leucine residues and formed a homo‐oligomer. The C‐terminal three amino acids of Daple were necessary for binding to the region containing the PDZ domain of Dvl. Expression of Daple in mouse fibroblast L cells inhibited Wnt‐3a‐induced accumulation of β‐catenin. Furthermore, Daple inhibited Wnt‐3a‐dependent activation of T‐cell factor (Tcf) transcriptional activity. Expression of Daple in the dorsal region of Xenopus embryos inhibited axis formation, which is known to be regulated by the Wnt signalling pathway. Daple also inhibited Dvl‐induced secondary axis formation in Xenopus embryos.Conclusions:   Daple binds to Dvl and functions as a negative regulator of the Wnt signalling pathway.
Crystal structure of the Pyrococcus horikoshii DNA primase‐UTP complex: implications for the mechanism of primer synthesis
Authors: Ito Nobutoshi , Nureki Osamu , Shirouzu Mikako , Yokoyama Shigeyuki , Hanaoka Fumio 
Published: December 2004

AbstractBackground:   In chromosomal DNA replication, DNA primase initiates the synthesis of a dinucleotide on a single‐stranded template DNA, and elongates it to form a primer RNA for the replicative DNA polymerase. Although the apo‐structure of an archaeal primase has been reported, the mechanism of primer synthesis by the eukaryotic‐type primase still remains to be elucidated.Results:   In this study, we present the crystal structure of the eukaryotic‐type DNA primase from the hyperthermophilic archaeon (Pyrococcus horikoshii) with the uridine 5′‐triphosphate (UTP). In the present primase‐UTP complex, the primase binds the triphosphate moiety of the UTP at the active site, which includes Asp95, Asp97, and Asp280, the essential residues for the nucleotidyl transfer reaction.Conclusion:   The nucleotide binding geometry in this complex explains the previous biochemical analyses of the eukaryotic primase. Based on the complex structure, we constructed a model between the DNA primase and a primer/template DNA for the primer synthesis. This model facilitates the comprehension of the reported features of DNA primase.
Traveltime computation by wavefront‐orientated ray tracing
Authors: Coman Radu , Gajewski Dirk 
Published: December 2004

ABSTRACTFor multivalued traveltime computation on dense grids, we propose a wavefront‐orientated ray‐tracing (WRT) technique. At the source, we start with a few rays which are propagated stepwise through a smooth two‐dimensional (2D) velocity model. The ray field is examined at wavefronts and a new ray might be inserted between two adjacent rays if one of the following criteria is satisfied: (1) the distance between the two rays is larger than a predefined threshold; (2) the difference in wavefront curvature between the rays is larger than a predefined threshold; (3) the adjacent rays intersect. The last two criteria may lead to oversampling by rays in caustic regions. To avoid this oversampling, we do not insert a ray if the distance between adjacent rays is smaller than a predefined threshold. We insert the new ray by tracing it from the source. This approach leads to an improved accuracy compared with the insertion of a new ray by interpolation, which is the method usually applied in wavefront construction. The traveltimes computed along the rays are used for the estimation of traveltimes on a rectangular grid. This estimation is carried out within a region bounded by adjacent wavefronts and rays. As for the insertion criterion, we consider the wavefront curvature and extrapolate the traveltimes, up to the second order, from the intersection points between rays and wavefronts to a gridpoint. The extrapolated values are weighted with respect to the distances to wavefronts and rays. Because dynamic ray tracing is not applied, we approximate the wavefront curvature at a given point using the slowness vector at this point and an adjacent point on the same wavefront. The efficiency of the WRT technique is strongly dependent on the input parameters which control the wavefront and ray densities. On the basis of traveltimes computed in a smoothed Marmousi model, we analyse these dependences and suggest some rules for a correct choice of input parameters. With suitable input parameters, the WRT technique allows an accurate traveltime computation using a small number of rays and wavefronts.
Depth and structural index from normalized local wavenumber of 2D magnetic anomalies
Authors: Salem Ahmed , Smith Richard 
Published: December 2004

ABSTRACTRecent improvements in the local wavenumber approach have made it possible to estimate both the depth and model type of buried bodies from magnetic data. However, these improvements require calculation of third‐order derivatives of the magnetic field, which greatly enhances noise. As a result, the improvements are restricted to data of high quality. We present an alternative method to estimate both the depth and model type using the first‐order local wavenumber approach without the need for third‐order derivatives of the field. Our method is based on normalization of the first‐order local wavenumber anomalies and provides a generalized equation to estimate the depth of some 2D magnetic sources regardless of the source structure. Information about the nature of the sources is obtained after the source location has been estimated. The method was tested using synthetic magnetic anomaly data with random noise and using three field examples.
Drought controls over conductance and assimilation of a Mediterranean evergreen ecosystem: scaling from leaf to canopy
Authors: Rambal Serge , Ourcival Jean‐Marc , Joffre Richard , Mouillot Florent , Nouvellon Yann , Reichstein Markus , Rocheteau Alain 
Published: December 2004

AbstractDrought control over conductance and assimilation was assessed using eddy flux and meteorological data monitored during four summer periods from 1998 to 2001 above a closed canopy of the Mediterranean evergreen oak tree Quercus ilex. Additional discrete measurements of soil water content and predawn leaf water potential were used to characterize the severity of the drought.Canopy conductance was estimated through the big‐leaf approach of Penman–Monteith by inverting latent heat fluxes. The gross primary production (GPP) was estimated by adding ecosystem respiration to net ecosystem exchange. Ecosystem respiration was deduced from night flux when friction velocity (u*) was greater than 0.35 m s−1. Empirical equations were identified that related maximal canopy conductance and daily ecosystem GPP to relative soil water content (RWC), the ratio of current soil water content to the field capacity, and to the predawn leaf water potential. Both variables showed a strong decline with soil RWC for values lower than 0.7. The sharpest decline was observed for GPP. The curves reached zero for RWC=0.41 and 0.45 for conductance and GPP, respectively. When the predawn leaf water potential was used as a surrogate for soil water potential, both variables showed a hyperbolic decline with decreasing water potential.These results were compared with already published literature values obtained at leaf level from the same tree species. Scaling up from the leaf to ecosystem highlighted the limitation of two big‐leaf representations: Penman–Monteith and Sellers' Π factor. Neither held completely for comparing leaf and canopy fluxes. Tower measurements integrate fluxes from foliage elements clumped at several levels of organization: branch, tree, and ecosystem. The Q. ilex canopy exhibited non‐random distribution of foliage, emphasizing the need to take into account a clumping index, the factor necessary to apply the Lambert–Beer law to natural forests.Our results showed that drought is an important determinant in water losses and CO2 fluxes in water‐limited ecosystems. In spite of the limitations inherent to the big‐leaf representation of the canopy, the equations are useful for predicting the influence of environmental factors in Mediterranean woodlands and for interpreting ecosystem exchange measurements.
Impact of soil warming and shading on colonization and community structure of arbuscular mycorrhizal fungi in roots of a native grassland community
Authors: Heinemeyer Andreas , Ridgway Karyn P. , Edwards Everard J. , Benham David G. , Young J. Peter W. , Fitter Alastair H. 
Published: December 2004

AbstractArbuscular mycorrhizal (AM) fungi have a major influence on the structure, responses and below‐ground C allocation of plant communities. Our lack of understanding of the response of AM fungi to factors such as light and temperature is an obstacle to accurate prediction of the impact of global climate change on ecosystem functioning. In order to investigate this response, we divided a grassland site into 24 plots, each either unshaded or partly shaded with soil either unheated or heated by 3°C at 2 cm depth. In both short‐term studies in spring and autumn, and in a 1‐year‐long study, we measured root length colonization (LRC) by AM and non‐AM fungi. For selected root samples, DNA sequences were amplified by PCR with fungal‐specific primers for part of the small sub‐unit (SSU) rRNA gene. In spring, the total LRC increased over 6 weeks from 12% to 25%. Shading significantly reduced AM but increased non‐AM fungal colonization, while soil warming had no effect. In the year‐long study, colonization by AM fungi peaked in summer, whereas non‐AM colonization peaked in autumn, when there was an additive effect of shading and soil warming that reduced AM but increased non‐AM fungi. Stepwise regression revealed that light received within the 7 days prior to sampling was the most significant factor in determining AM LRC and that mean temperature was the most important influence on non‐AM LRC. Loglinear analysis confirmed that there were no seasonal or treatment effects on the host plant community. Ten AM fungal sequence types were identified that clustered into two families of the Glomales, Glomaceae and Gigasporaceae. Three other sequence types were of non‐AM fungi, all Ascomycotina. AM sequence types showed seasonal variation and shading impacts: loglinear regression analysis revealed changes in the AM fungal community with time, and a reduction of one Glomus sp. under shade, which corresponded to a decrease in the abundance of Trifolium repens. We suggest that further research investigating any impacts of climate change on ecosystem functioning must not only incorporate their natural AM fungal communities but should also focus on niche separation and community dynamics of AM fungi.
Storage and sequestration potential of topsoil organic carbon in China's paddy soils
Authors: Pan Genxing , Li Lianqing , Wu Laosheng , Zhang Xuhui 
Published: December 2004

AbstractCarbon (C) storage and sequestration in agricultural soils is considered to be an important issue in the study of terrestrial C cycling and global climatic change. The baseline C stock and the C sequestration potential are among the criteria for a region or a state to adopt strategies or policies in response to commitment to the Kyoto Protocol. Paddy soils represent a large portion of global cropland. However, little information on the potential of C sequestration and storage is available for such soils. In this paper, an estimation of the topsoil soil organic carbon (SOC) pool and the sequestration potential of paddy soils in China was made by using the data from the 2nd State Soil Survey carried out during 1979–1982 and from the nationwide arable soil monitoring system established since then. Results showed that the SOC density ranged from 12 to 226 t C ha−1 with an area‐weighted mean density of 44 t C ha−1, which is comparable to that of the US grasslands and is higher than that of the cultivated dryland soils in China and the US. The estimated total topsoil SOC pool is 1.3 Pg, with 0.85 Pg from the upper plow layer and 0.45 Pg from the plowpan layer. This pool size is ∼2% of China's total storage in the top 1 m of the soil profiles and ∼4% of the total topsoil pool, while the area percentage of paddy soil is 3.4% of the total land. The C pool in paddy soils was found predominantly in southeast China geographically and in the subgroups of Fe‐accumulating and Fe‐leaching paddy soils pedogenetically. In comparison with dryland cultivation, irrigation‐based rice cultivation in China has induced significant enrichment of SOC storage (0.3 Pg) in paddy soils. The induced total C sequestration equals half of China's total annual CO2 emission in the 1990s. Estimates using different SOC sequestration scenarios show that the paddy soils of China have an easily attainable SOC sequestration potential of 0.7 Pg under present conditions and may ultimately sequester 3.0 Pg. Soil monitoring data showed that the current C sequestration rate is 12 Tg yr−1. The total C sequestration potential and the current sequestration rate of the paddy soils are over 30%, while the area of the paddy soils is 26% that of China's total croplands. Therefore, practicing sustainable agriculture is urgently needed for enhancing SOC storage to realize the ultimate SOC sequestration of rice‐based agriculture of China, as the current C sequestration rate is significantly lower than the potential rate.
Estimating soil carbon fluxes following land‐cover change: a test of some critical assumptions for a region in Costa Rica
Authors: Powers Jennifer S. , Read Jane M. , Denslow Julie S. , Guzman Sandra M. 
Published: December 2004

AbstractChanges in soil carbon storage that accompany land‐cover change may have significant effects on the global carbon cycle. The objective of this work was to examine how assumptions about preconversion soil C storage and the effects of land‐cover change influence estimates of regional soil C storage. We applied three models of land‐cover change effects to two maps of preconversion soil C in a 140  000 ha area of northeastern Costa Rica. One preconversion soil C map was generated using values assigned to tropical wet forest from the literature, the second used values obtained from extensive field sampling. The first model of land‐cover change effects used values that are typically applied in global assessments, the second and third models used field data but differed in how the data were aggregated (one was based on land‐cover transitions and one was based on terrain attributes). Changes in regional soil C storage were estimated for each combination of model and preconversion soil C for three time periods defined by geo‐referenced land‐cover maps.The estimated regional soil C under forest vegetation (to 0.3 m) was higher in the map based on field data (10.03 Tg C) than in the map based on literature data (8.90 Tg C), although the range of values derived from propagating estimation errors was large (7.67–12.40 Tg C). Regional soil C storage declined through time due to forest clearing for pasture and crops. Estimated CO2 fluxes depended more on the model of land‐cover change effects than on preconversion soil C. Cumulative soil C losses (1950–1996) under the literature model of land‐cover effects exceeded estimates based on field data by factors of 3.8–8.0. In order to better constrain regional and global‐scale assessments of carbon fluxes from soils in the tropics, future research should focus on methods for extrapolating regional‐scale constraints on soil C dynamics to larger spatial and temporal scales.
Soil CO2 efflux in a boreal pine forest under atmospheric CO2 enrichment and air warming
Authors: Niinistö Sini Maaria , Silvola Jouko , Kellomäki Seppo 
Published: December 2004

AbstractThe response of forest soil CO2 efflux to the elevation of two climatic factors, the atmospheric concentration of CO2 (↑CO2 of 700 μmol mol−1) and air temperature (↑T with average annual increase of 5°C), and their combination (↑CO2+↑T) was investigated in a 4‐year, full‐factorial field experiment consisting of closed chambers built around 20‐year‐old Scots pines (Pinus sylvestris L.) in the boreal zone of Finland. Mean soil CO2 efflux in May–October increased with elevated CO2 by 23–37%, with elevated temperature by 27–43%, and with the combined treatment by 35–59%. Temperature elevation was a significant factor in the combined 4‐year efflux data, whereas the effect of elevated CO2 was not as evident. Elevated temperature had the most pronounced impact early and late in the season, while the influence of elevated CO2 alone was especially notable late in the season. Needle area was found to be a significant predictor of soil CO2 efflux, particularly in August, a month of high root growth, thus supporting the assumption of a close link between whole‐tree physiology and soil CO2 emissions. The decrease in the temperature sensitivity of soil CO2 efflux observed in the elevated temperature treatments in the second year nevertheless suggests the existence of soil response mechanisms that may be independent of the assimilating component of the forest ecosystem. In conclusion, elevated atmospheric CO2 and air temperature consistently increased forest soil CO2 efflux over the 4‐year period, their combined effect being additive, with no apparent interaction.
Aphid individual performance may not predict population responses to elevated CO2 or O3
Authors: Awmack Caroline S. , Harrington Richard , Lindroth Richard L. 
Published: December 2004

AbstractChanges in atmospheric composition affect plant quality and herbivore performance. We used the Aspen Free Air CO2 Enrichment (FACE) facility to investigate the impacts of elevated carbon dioxide (CO2) and ozone (O3) on the performance of the aphid Cepegillettea betulaefoliae Granovsky feeding on paper birch (Betula papyrifera Marsh.). In Year 1, we simultaneously measured individual performance and population growth rates, and in Year 2 we surveyed natural aphid, predator and parasitoid populations throughout the growing season. Aphid growth and development (relative growth rate (RGR), development time, adult weight, embryo number and the birth weight of newborn nymphs) were unaffected by CO2 and O3. Aphid fecundity decreased on trees grown at elevated CO2, O3 and CO2+O3. Neither nymphal performance nor adult size were reliable indicators of future fecundity at elevated CO2 and/or O3. Aphid populations protected from natural enemies were unaffected by elevated CO2, but increased significantly at elevated O3. Individual fecundity in elevated CO2 and O3 atmospheres did not predict population growth rates, probably because of changes in the strength of intraspecific competition or the ability of the aphids to induce nutrient sinks. Natural aphid, predator and parasitoids populations (Year 2) showed few significant responses to CO2 and O3, although CO2 and O3 did affect the timing of aphid and natural enemy peak abundance. Elevated CO2 and O3 affected aphid and natural enemy populations independently: no CO2× O3 interactions were observed. We conclude that: (1) aphid individual performance did not predict population responses to CO2 and O3 and (2) elevated CO2 and O3 atmospheres are unlikely to affect C. betulaefoliae populations in the presence of natural enemy communities.