bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uncertainties in the response of a forest landscape to global climatic change
Authors: XU CHONGGANG , GERTNER GEORGE Z. , SCHELLER ROBERT M. 
Published: November 2008

AbstractMany studies have been conducted to quantify the possible ecosystem/landscape response to the anticipated global warming. However, there is a large amount of uncertainty in the future climate predictions used for these studies. Specifically, the climate predictions can be very different based on a variety of global climate models and alternative greenhouse emission scenarios. In this study, we coupled a forest landscape model, LANDIS‐II, and a forest process model, PnET‐II, to examine the uncertainty (that results from the uncertainty in the future climate predictions) in the forest‐type composition prediction for a transitional forest landscape [the Boundary Water Canoe Area]. Using an improved global‐sensitivity analysis technique [Fourier amplitude sensitivity test], we also quantified the amount of uncertainty in the forest‐type composition prediction contributed by different climate variables including temperature, CO2, precipitation and photosynthetic active radiation (PAR). The forest landscape response was simulated for the period 2000–2400 ad based on the differential responses of 13 tree species under an ensemble of 27 possible climate prediction profiles (monthly time series of climate variables). Our simulations indicate that the uncertainty in the forest‐type composition becomes very high after 2200 ad, which is close to the time when the current forests are largely removed by windthrow disturbances and natural mortality. The most important source of uncertainty in the forest‐type composition prediction is from the uncertainty in temperature predictions. The second most important source is PAR, the third is CO2 and the least important is precipitation. Our results also show that if the optimum photosynthetic temperature rises due to CO2 enrichment, the forest landscape response to climatic change measured by forest‐type composition may be substantially reduced.
Pan‐European regional‐scale modelling of water and  N efficiencies of rapeseed cultivation for biodiesel production
Authors: VAN DER VELDE MARIJN , BOURAOUI FAYÇAL , ALOE ALBERTO 
Published: November 2008

AbstractThe energy produced from the investment in biofuel crops needs to account for the environmental impacts on soil, water, climate change and ecosystem services. A regionalized approach is needed to evaluate the environmental costs of large‐scale biofuel production. We present a regional pan‐European simulation of rapeseed (Brassica napus) cultivation. Rapeseed is the European Union's dominant biofuel crop with a share of about 80% of the feedstock. To improve the assessment of the environmental impact of this biodiesel production, we performed a pan‐European simulation of rapeseed cultivation at a 10 × 10 km scale with Environmental Policy Integrated Climate (EPIC). The model runs with a daily time step and model input consists of spatialized meteorological measurements, and topographic, soil, land use, and farm management practices data and information. Default EPIC model parameters were calibrated based on literature. Modelled rapeseed yields were satisfactory compared with yields at regional level reported for 151 regions obtained for the period from 1995 to 2003 for 27 European Union member countries, along with consistent modelled and reported yield responses to precipitation, radiation and vapour pressure deficit at regional level. The model is currently set up so that plant nutrient stress is not occurring. Total fertilizer consumption at country level was compared with IFA/FAO data. This approach allows us to evaluate environmental pressures and efficiencies arising from and associated with rapeseed cultivation to further complete the environmental balance of biofuel production and consumption.
Carbon sequestration in boreal jack pine stands following harvesting
Authors: ZHA TIANSHAN , BARR ALAN G. , BLACK T. ANDY , McCAUGHEY J. HARRY , BHATTI J. , HAWTHORNE I. , KRISHNAN PRAVEENA , KIDSTON J. , SAIGUSA N. , SHASHKOV A. , NESIC Z. 
Published: November 2008

AbstractA large area of boreal jack pine (Pinus banksiana Lamb.) forest in Canada is recovering from clear‐cut harvesting, and the carbon (C) balance of these regenerating forests remains uncertain. Net ecosystem CO2 exchange was measured using the eddy‐covariance technique at four jack pine sites representing different stages of stand development: three postharvest sites (HJP02, HJP94, and HJP75) and one preharvest site (OJP). The four sites, located in the southern Canadian boreal forest, Saskatchewan, Canada, are typical of low productivity jack pine stands and were 2, 10, 29, and 90 years old in 2004, respectively. Mean annual net ecosystem production (NEP) for 2004 and 2005 was −137±11, 19±16, 73±28, and 22±30 g C m−2 yr−1 at HJP02, HJP94, HJP75 and OJP, respectively, showing the postharvest jack pine stands to be moderate C sources immediately after harvesting, weak sinks at 10 years, moderate C sinks at 30 years, then weak C sinks at 90 years. Mean annual gross ecosystem photosynthesis (GEP) for the 2 years was 96±10, 347±20, 576±34, and 583±35 g C m−2 yr−1 at HJP02, HJP94, HJP75, and OJP, respectively. The ratio of annual ecosystem respiration (R) to annual GEP was 2.51±0.15, 0.95±0.04, 0.87±0.03, and 0.96±0.03. Seasonally, NEP peaked in May or June at all four sites but GEP and R were highest in July. R at a reference soil temperature of 10 °C, ecosystem quantum yield and photosynthetic capacity were lowest for the 2‐year‐old stand. R was most sensitive to soil temperature for the 90‐year‐old stand. The primary source of variability in NEP over the course of succession of the jack pine ecosystem following harvesting was stand age due to the changes in leaf area index. Intersite variability in GEP and R was an order of magnitude greater than interannual variability at OJP. For both young and old stands, GEP had greater interannual variability than R and played a more important role than R in interannual variation in NEP. Based on year‐round flux measurements from 2000 to 2005, the 10‐year stand had larger interannual variability in GEP and R than the 90‐year stand. Interannual variability in NEP was driven primarily by early‐growing‐season temperature and growing‐season length. Photosynthesis played a dominant role in the rapid rise in NEP early in stand development. Late in stand development, however, the subtle decrease in NEP resulted primarily from increasing respiration.
Nucleotide diversity in the Hsp90 gene in natural populations of Drosophila melanogaster from Australia
Authors: Sgrò C. M. , Milton C. C. , Jensen L. T. , Frydenberg J. , Loeschcke V. , Batterham P. , Hoffmann A. A. 
Published: November 2008

AbstractHsp90 is regarded as one of the best candidates for an evolved mechanism that regulates the expression of genetic and phenotypic variability. We examined nucleotide diversity in both the promoter and coding regions of Hsp90, the gene which encodes Hsp90 in Drosophila, in natural populations of Drosophila melanogaster from eastern Australia. We found that Hsp90 is polymorphic for only two nonsynonymous changes in the coding region, both of which are deletions of a lysine residue. One of these lysine deletions was in complete linkage disequilibrium with the inversion In(3L)P, and showed a significant association with latitude. The other lysine deletion reported here for the first time varied from 0 to 15% in natural populations, but did not show a clinal pattern. The regulatory and coding regions of Hsp90 showed very low nucleotide diversity compared to other nuclear genes, and chromosomes containing In(3L)P had lower levels of nucleotide diversity than the standard arrangements. Non‐neutral evolution of Hsp90 was not supported by analyses of either the regulatory or coding regions of the gene. These results are discussed within the context of Hsp90 variation being involved in thermotolerance as well as the expression of genetic and phenotypic variability.
Radiographic assessment of dental anomalies in patients with ectopic maxillary canines
Authors: SØRENSEN HELLE BUDTZ , ARTMANN LONE , LARSEN HELLE JUUL , KJÆR INGER 
Published: November 2008

Background.  The aetiology of palatally and labially located ectopic maxillary canines is multifactorial. Accordingly, early prediction of this eruptional disturbance is in most cases not possible.Aim.  The purpose of this study was to analyse dental deviations in cases with either palatal or labial ectopic canines.Design.  Panoramic and intra‐oral radiographs from 50 patients with palatally located (38 females and 12 males) and 19 patients with labially located ectopic canines (11 females and 8 males), aged 10 years, 2 months–18 years, 1 month, were analysed. Dental deviations registered were crown and root malformations, agenesis, and eruption deviations. Registrations were performed in the maxillary incisor field and in the dentition in general.Results.  The study documented that palatally as well as labially located ectopic canines can occur in dentitions without other dental deviations. Dental deviations occurred in approximately two‐thirds of all cases, more often in females and in cases with palatally located canines. More than half of the females with palatally located canines had deviations in the maxillary incisors and in the dentition in general.Conclusion.  Dental deviations may be considered a risk factor for maxillary canine ectopia. Early identification of patients at risk and appropriate interceptive treatment may reduce ectopic eruption of maxillary canines.
Contextual variables affecting aggressive behaviour in individuals with mild to borderline intellectual disabilities who live in a residential facility
Authors: Embregts P. J. C. M. , Didden R. , Huitink C. , Schreuder N. 
Published: November 2008

AbstractBackground  Aggression is a common type of problem behaviour in clients with mild to borderline intellectual disability who live in a residential facility. We explored contextual events that elicit aggressive behaviour and variables that were associated with such events.Method  Respondents were 87 direct‐care staff members of 87 clients with aggressive behaviour who lived in a residential facility. Staff members completed the Contextual Assessment Inventory (CAI) and a questionnaire on demographic information and types, frequency and severity of aggressive behaviour. Internal consistency of the total CAI was excellent (α = 0.95), and Cronbach alpha's for the CAI sub‐scales ranged from 0.75 to 0.93. Inter‐rater agreement for the CAI could be considered good (mean intra‐class correlation coefficient = 0.63).Results  Both social and task‐related events were reported to evoke aggressive behaviour of clients most often. Negative interactions, task characteristics and daily routines relatively often evoked aggressive behaviour while an uncomfortable environment, medication, illness and physiological states (i.e. physical and biological events) evoked aggressive behaviour least often. Mean CAI sub‐scale scores were significantly related to gender, IQ and frequency of aggressive behaviour.Conclusion  The present study extends our knowledge regarding events that are associated with an increased probability of aggressive behaviour. Knowledge of these contextual variables may be helpful in designing programmes (e.g. applied behaviour analysis, social skills training and cognitive behavioural therapies) for the management and prevention of aggressive behaviour in clients with mild to borderline intellectual disability who live in a residential facility.
Spatial genetic structure of a small rodent in a heterogeneous landscape
Authors: GAUFFRE B. , ESTOUP A. , BRETAGNOLLE V. , COSSON J. F. 
Published: November 2008

AbstractGene flow in natural populations may be strongly influenced by landscape features. The integration of landscape characteristics in population genetic studies may thus improve our understanding of population functioning. In this study, we investigated the population genetic structure and gene flow pattern for the common vole,Microtus arvalis, in a heterogeneous landscape characterised by strong spatial and temporal variation. The studied area is an intensive agricultural zone of approximately 500 km2crossed by a motorway. We used individual‐based Bayesian methods to define the number of population units and their spatial borders without prior delimitation of such units. Unexpectedly, we determined a single genetic unit that covered the entire area studied. In particular, the motorway considered as a likely barrier to dispersal was not associated with any spatial genetic discontinuity. Using computer simulations, we demonstrated that recent anthropogenic barriers to effective dispersal are difficult to detect through analysis of genetic variation for species with large effective population sizes. We observed a slight, but significant, pattern of isolation by distance over the whole study site. Spatial autocorrelation analyses detected genetic structuring on a local scale, most probably due to the social organisation of the study species. Overall, our analysis suggests intense small‐scale dispersal associated with a large effective population size. High dispersal rates may be imposed by the strong spatio‐temporal heterogeneity of habitat quality, which characterises intensive agroecosystems.
Phylogeography of native ploidy levels and invasive tetraploids of Solidago gigantea
Authors: SCHLAEPFER DANIEL R. , EDWARDS PETER J. , WIDMER ALEX , BILLETER REGULA 
Published: November 2008

AbstractPloidy level is an important aspect of the genetic makeup of a plant, and can strongly influence ecological characteristics such as invasiveness. We used a phylogeographical approach to elucidate the history of polyploidization and colonization success of diploid and tetraploid Solidago gigantea Aiton (Asteraceae) within its native range in North America. We were also able to identify the probable source material of the haplotype lineages invasive in Europe and Asia, where only tetraploid plants occur. To do this, we sequenced 1275 bp of chloroplast intergenic spacer DNA in 268 individuals from 57 populations. In addition, we performed a crossing experiment, which supported the hypothesis that chloroplast inheritance in this species is maternal. The phylogeographical analysis showed a complex pattern of 20 haplotypes of diploid and tetraploid plants. In North America, we found significant differentiation among regions, private haplotypes, and isolation by distance. Ploidy levels were more differentiated in the northern regions than in the South. The haplotype network was shallow and included one tetraploid‐only, star‐shaped cluster of haplotypes that were particularly successful colonizers. Post‐glacial migration of diploid S. gigantea occurred mainly northwards east of the Appalachian Mountains, and to a lesser degree also southward. Our data suggest that tetraploids have formed several times in North America. Haplotype number and diversity were lower in European populations than in the native range, and we found evidence that four haplotypes were introduced to Europe from two source areas, New England and the Southern Appalachian Mountains.
Analysis of structure and function of the giant protein Pf332 in Plasmodium falciparum
Authors: Hodder Anthony N. , Maier Alexander G. , Rug Melanie , Brown Monica , Hommel Mirja , Pantic Ivan , Puig‐de‐Morales‐Marinkovic Marina , Smith Brian , Triglia Tony , Beeson James , Cowman Alan F. 
Published: November 2008

SummaryVirulence of Plasmodium falciparum, the most lethal parasitic disease in humans, results in part from adhesiveness and increased rigidity of infected erythrocytes. Pf332 is trafficked to the parasite‐infected erythrocyte via Maurer's clefts, structures for protein sorting and export in the host erythrocyte. This protein has a domain similar to the Duffy‐binding‐like (DBL) domain, which functions by binding to receptors for adherence and invasion. To address structure of the Pf332 DBL domain, we expressed this region, and validated its fold on the basis of the disulphide bond pattern, which conformed to the generic pattern for DBL domains. The modelled structure for Pf332 DBL had differences compared with the erythrocyte‐binding region of the αDBL domain of Plasmodium knowlesi Duffy‐binding protein (Pkα‐DBL). We addressed the function of Pf332 by constructing parasites that either lack expression of the protein or express an altered form. We found no evidence that Pf332 is involved in cytoadhesion or merozoite invasion. Truncation of Pf332 had a significant effect on deformability of the P. falciparum‐infected erythrocyte, while loss of the full protein deletion did not. Our data suggest that Pf332 may contribute to the overall deformability of the P. falciparum‐infected erythrocyte by anchoring and scaffolding.
Repression of galP, the galactose transporter in Escherichia coli, requires the specific regulator of N‐acetylglucosamine metabolism
Authors: El Qaidi Samir , Allemand Frédéric , Oberto Jacques , Plumbridge Jacqueline 
Published: November 2008

SummarySoupene et al. [J. Bacteriol. (2003) 185 5611–5626] made the unexpected observation that the presence of a mutation, in the gene for the N‐acetylglucosamine repressor, nagC, increased the growth rate of Escherichia coli MG1655 on galactose, an unrelated sugar. We have found that NagC, binds to a single, high‐affinity site overlapping the promoter of galP (galactose permease) gene and that expression of galP is repressed by a combination of NagC, GalR and GalS. In addition to the previously identified galOE operator, other gal operators further upstream are required for full repression. GalS has a specific role, as it binds with higher affinity to one of the upstream operators but its effect in vivo is only observed in the presence of GalR. Regulation of galP by three specific repressors, NagC, GalR and GalS is unusual in that it involves multiple, specific regulators from two different areas of metabolism. This novel regulation seems to be particular for E. coli and its nearest neighbour, Shigella. Other bacteria with galP orthologues, although retaining the metK‐galP gene order, do not have the NagC site. Although quantitative effects were strain specific, nagC mutations increased the growth rate on galactose of all E. coli strains tested.
DNA polymerase switching: effects on spontaneous mutagenesis inEscherichia coli
Authors: Curti Elena , McDonald John P. , Mead Samantha , Woodgate Roger 
Published: November 2008

SummaryEscherichia colipossesses five known DNA polymerases (pols). Pol III holoenzyme is the cell's main replicase, while pol I is responsible for the maturation of Okazaki fragments and filling gaps generated during nucleotide excision repair. Pols II, IV and V are significantly upregulated as part of the cell's global SOS response to DNA damage and under these conditions, may alter the fidelity of DNA replication by potentially interfering with the ability of pols I and III to complete their cellular functions. To test this hypothesis, we determined the spectrum ofrpoBmutations arising in an isogenic set ofmutLstrains differentially expressing the chromosomally encoded pols. Interestingly, mutagenic hot spots inrpoBwere identified that are susceptible to the actions of pols I–V. For example, in arecA730 lexA(Def)mutLbackground most transversions were dependent upon pols IV and V. In contrast, transitions were largely dependent upon pol I and to a lesser extent, pol III. Furthermore, the extent of pol I‐dependent mutagenesis at one particular site was modulated by pols II and IV. Our observations suggest that there is considerable interplay among all fiveE. colipolymerases that either reduces or enhances the mutagenic load on theE. colichromosome.
Purification of low‐abundance Arabidopsis plasma‐membrane protein complexes and identification of candidate components
Authors: Qi Yiping , Katagiri Fumiaki 
Published: November 2008

SummaryPurification of low‐abundance plasma‐membrane (PM) protein complexes is a challenging task. We devised a tandem affinity purification tag termed the HPB tag, which contains the biotin carboxyl carrier protein domain (BCCD) of Arabidopsis 3‐methylcrotonal CoA carboxylase. The BCCD is biotinylated in vivo, and the tagged protein can be captured by streptavidin beads. All five C‐terminally tagged Arabidopsis proteins tested, including four PM proteins, were functional and biotinylated with high efficiency in Arabidopsis. Transgenic Arabidopsis plants expressing an HPB‐tagged protein, RPS2::HPB, were used to develop a method to purify protein complexes containing the HPB‐tagged protein. RPS2 is a membrane‐associated disease resistance protein of low abundance. The purification method involves microsomal fractionation, chemical cross‐linking, solubilization, and one‐step affinity purification using magnetic streptavidin beads, followed by protein identification using LC‐MS/MS. We identified RIN4, a known RPS2 interactor, as well as other potential components of the RPS2 complex(es). Thus, the HPB tag method is suitable for the purification of low‐abundance PM protein complexes.
VH1/BRL2 receptor‐like kinase interacts with vascular‐specific adaptor proteins VIT and VIK to influence leaf venation
Authors: Ceserani Teresa , Trofka Anna , Gandotra Neeru , Nelson Timothy 
Published: November 2008

SummaryVH1/BRL2 is a receptor‐like kinase of the BRI1 family with a role in vascular development. In developing Arabidopsis leaves it is expressed first in ground cells and then becomes restricted to provascular and procambial cells as venation forms. We isolated proteins interacting with the activated (phosphorylated) cytoplasmic domain of VH1/BRL2, and found that most belong to three processes: proteasome activity, vesicle traffic and intracellular signal transduction. Two adaptor proteins are included that we named VIT [VH1‐interacting tetratricopeptide repeat (TPR)‐containing protein] and VIK (VH1‐interacting kinase), which are co‐expressed in the same cells as VH1/BRL2 at two distinct time points in vein differentiation. Mutation of either adaptor or of VH1 results in vein pattern defects and in alterations in response to auxin and brassinosteroids. We propose that these two adaptors facilitate the diversification and amplification of a ligand signal perceived by VH1/BRL2 in multiple downstream pathways affecting venation.
Generalized pustulosis induced by adalimumab in a patient with rheumatoid arthritis – a therapeutic challenge
Authors: Kucharekova Martina , Winnepenninckx Véronique , Frank Jorge , Poblete‐Gutiérrez Pamela 
Published: November 2008

AbstractTumor necrosis factor‐alpha (TNF‐α) inhibitors such as adalimumab are increasingly used in the treatment of chronic inflammatory diseases, including rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis. In Europe, this group of drugs also has been approved for therapy of moderate to severe psoriasis recently. With increased application of adalimumab, the possible adverse effects occurring in the course of treatment steadily gained more attention. Among these, infection and localized skin eruptions are the most common. Usually, the cutaneous symptoms rapidly resolve after discontinuation of the drug. Here, however, we report on a woman with rheumatoid arthritis who developed a therapy‐refractory, generalized pustular rash during treatment with adalimumab. After different unsuccessful therapeutic attempts, only a combined treatment with prednisone, methotrexate, and cyclosporinee eventually led to marked improvement. To the best of our knowledge, this is the first report on a generalized, therapy‐resistant pustulosis as an adverse effect of adalimumab.