bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reproductive isolation between chromosomal races of the house mouseMus musculus domesticusin a parapatric contact area revealed by an analysis of multiple unlinked loci
Authors: FRANCHINI P. , CASTIGLIA R. , CAPANNA E. 
Published: February 2008

AbstractThe house mouse,Mus musculus domesticus, exhibits a high level of chromosomal polymorphism because of the occurrence and fast fixation of Robertsonian fusions between telocentric chromosomes. For this reason, it has been considered a classical speciation model to analyse the role of the chromosomal changes in reproductive isolation. In this study, we analysed a parapatric contact area between two metacentric races in central Italy, the Cittaducale race (CD: 2n = 22) and the Ancarano race (ACR: 2n = 24), to estimate gene flow at the boundary. Hybrids between these two races show high levels of structural heterozygosity and are expected to be highly infertile. A sample of 88 mice from 14 sites was used. The mice were genotyped by means of eight microsatellite loci mapped in four different autosomal arms. The results show clear genetic differentiation between the CD and ACR races, as revealed by differences in allele frequencies, factorial correspondence analysis and indexes of genetic population (e.g.FSTandRST) along the contact zone. The genetic differentiation between the races was further highlighted by assignation and clustering analyses, in which all the individuals were correctly assigned by their genotypes to the source chromosomal race. This result is particularly interesting in view of the absence of any geographical or ecological barrier in the parapatric contact zone, which occurs within a village. In these conditions, the observed genetic separation suggests an absence of gene flow between the races. The CD–ACR contact area is a rare example of a final stage of speciation between chromosomal races of rodents because of their chromosomal incompatibility.
Integrating marker assisted background analysis with foreground selection for identification of superior bacterial blight resistant recombinants in Basmati rice
Authors: Gopalakrishnan S. , Sharma R. K. , Anand Rajkumar K. , Joseph M. , Singh V. P. , Singh A. K. , Bhat K. V. , Singh N. K. , Mohapatra T. 
Published: February 2008

AbstractBasmati rice is highly susceptible to bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae. Transfer of BB resistance genes from non‐Basmati sources to Basmati through cross‐hybridization requires strict monitoring for recovery of the desirable Basmati quality traits in the recombinants, which show complex inheritance pattern. We integrated background analysis using mapped microsatellite markers with foreground selection to identify superior lines that combine useful genes from a non‐Basmati BB resistance donor line IRBB55 with grain and cooking quality characteristics of the popular Basmati rice variety ‘Pusa Basmati 1’ (PB 1) employing backcross pedigree strategy. Foreground selection using linked markers ensured presence of two genes, xa13 and Xa21 for BB resistance from IRBB55, and the recurrent parent PB 1 allele for the waxy locus giving intermediate amylose content and maintainer allele at fertility restorer locus in the BC1F5 recombinants. Background analysis enabled selection of recombinants with recurrent parent genome to the extent of 86.3% along with the quality traits. The extent of introgression of non‐Basmati donor chromosome segments in the superior selections was estimated to be < 7.8 Mb and < 6.7 Mb in the xa13 and Xa21 linked genomic regions, respectively. Association mapping identified three quantitative trait loci, one each for 1000‐grain weight, fertile grains/panicle and cooked kernel length. The backcross‐pedigree breeding strategy facilitated recovery of additional desirable characteristics from the donor in some of the selections. The elite selection Pusa 1460‐01‐32‐6‐7‐67 with maximum genomic background and quality characteristics of the recurrent Basmati parent gave resistance reaction against BB, similar to that of the non‐Basmati resistant check variety and recorded an yield advantage of 11.9% over the best check in the multiplication agronomic trial in the Basmati growing region of India. This line, which has been released as a new variety in the name of ‘Improved Pusa Basmati 1’ for commercial cultivation in India, is an example of successful application of marker assisted selection to variety development.
A SINGULAR INTEGRAL EQUATION SOLUTION FOR THE LINEAR ELASTIC CRACK OPENING DISPLACEMENT OF AN ARBITRARILY SHAPED PLANE CRACK: PART I FINITE‐PART INTEGRAL SOLUTIONS
Authors: Mayrhofer K. , Fischer F. D. 
Published: February 2008

Abstract— The aim of the paper is to compute the local crack face displacements of a linear elastic body containing an arbitrarily shaped plane crack. From the crack face displacements the local stress intensity factors can be derived.The boundary value problem for a plane crack of arbitrary shape, embedded in a linear elastic medium, has been treated by several authors by the singular integral equation (SIE) approach. Their computations lead to a set of hyper‐singular integral equations for the Cartesian components of the unknown crack face displacements. To solve these equations the authors present a discretization procedure based on six‐node triangular finite elements. A total set of 24 finite‐part integrals defined over a triangular area can be developed. These 2D‐finite‐part integrals can be split into both a 1D‐regular and a 1D‐finite‐part‐integral by means of the polar coordinates so that they can be solved in closed form. Finally, the investigation of the SIEs is reduced to a discrete set of linear algebraic equations for the unknown nodal point values. The necessary steps will be demonstrated in detail. The derived closed‐form solutions will be offered in the text and in the appendices.
A SIMPLE TEST METHOD FOR ENERGY DISSIPATION RATE, CTOA AND THE STUDY OF SIZE AND TRANSFERABILITY EFFECTS FOR LARGE AMOUNTS OF DUCTILE CRACK GROWTH
Authors: Turner C. E. , Kolednik O. 
Published: February 2008

Abstract— Simple extensions to the standard deep notch bend test procedure are suggested to allow the collection of data relevant to the energy dissipation rate, D, crack opening angle, COA, and J, all for arbitrarily large amounts of growth in extensive plasticity. The methods of analysis are detailed for real elastic‐plastic behaviour of a high strength low‐hardening type metal with a view to encouraging use on a wider range of materials. A proposal is made, and equations given, that the particular version of J used for an R‐curve derived from the area under the loading diagram, should correspond to the value of the far‐field integral, Jff.The relationship between the global measure of COA that emerges from D and the local crack tip opening angle, CTOA, as used in computational studies, is established. Transferability of CTOA data is examined in the light of effects of size and configuration. An explicit rule of the form CTOA √G =f (material and configuration) is proposed for the modelling of ductile growth in finite element studies. It is applied to a set of data in the literature, for the variation of CTOA with size in the deep notch bend test and for the configurations, bending, double edge and centre cracked tension.
Detection of novel Fibrobacter populations in landfill sites and determination of their relative abundance via quantitative PCR
Authors: McDonald James E. , Lockhart Robert J. , Cox Michael J. , Allison Heather E. , McCarthy Alan J. 
Published: February 2008

SummaryMembers of the bacterial genus Fibrobacter have long been considered important components of the anaerobic cellulolytic community in the herbivore gut, but their presence and activity in other environments is largely unknown. In this study, a specific polymerase chain reaction (PCR) primer set, targeting the 16S rRNA gene of Fibrobacter spp., was applied to community DNA from five landfill sites followed by temporal thermal gel electrophoresis (TTGE) analysis of cloned amplification products. Phylogenetic analysis of clone sequences indicated the presence of novel clusters closely related to the genus Fibrobacter. There are two named species, Fibrobacter succinogenes and F. intestinalis, and only two of the 58 sequenced clones were identified with them, and both were F. succinogenes. The clone sequences from landfill were recovered in five distinct clusters within the Fibrobacter lineage, and four of these were novel. Quantitative PCR (qPCR) assays of reverse‐transcribed community RNA from landfill leachates and rumen fluid samples indicated that the abundance of Fibrobacter spp. relative to total bacteria varied from 0.2% to 40% in landfill, and 21% to 32% in the rumen, and these data demonstrate that fibrobacters can be a significant component of the microbial community in landfill ecosystems. This is the first evidence for Fibrobacter spp. outside the gut ecosystem, and as the only cultivated representatives of this group are actively cellulolytic, their diversity and abundance points to a possible role in cellulose hydrolysis in landfill, and perhaps other anaerobic environments also.
Revealing biogeographical patterns by nonlinear ordinations and derived anisotropic spatial filters
Authors: Mahecha Miguel D. , Schmidtlein Sebastian 
Published: February 2008

ABSTRACTAim  Spatial floristic and faunistic data bases promote the investigation of biogeographical gradients in relation to environmental determinants on regional to continental scales. Our aim was to extract major gradients in the distribution of vascular plant species from a grid‐based inventory (the German FLORKART data base) and relate them to long‐term precipitation and temperature records as well as soil conditions. We present an ordination technique capable of coping with this complex data array. The goal was also to sort out the influence of spatial autocorrelation, assuming floristic autocorrelation is anisotropic.Location  Germany, at a spatial resolution of 6′ × 10′.Methods  Isometric feature mapping (Isomap) was applied as a nonlinear ordination method. Isomap was coupled to ‘eigenvector‐based filters’ for generating spatial reference models representing spatial autocorrelation. What is novel here is that the derived filters are not based on the assumption of equidirectional autocorrelation. Instead, the so‐called ‘principal coordinates of anisotropic neighbour matrices’ build filters to test the influence of geographical vicinity in directions of high similarity among observations.Results  The Isomap ordination of floristic data explained more than 95% of the data variance in six dimensions. The leading two dimensions (representing about 80% of the FLORKART data variance) revealed clear spatial gradients that could be related to independent effects of temperature, precipitation and soil observations. By contrast, the third and higher FLORKART dimensions were dominated by an antagonism of anisotropic spatial autocorrelation and soil conditions. A subsequent cluster analysis of the floristic Isomap coordinates educed the spatial organization of the floristic survey, indicating a considerable sampling bias.Conclusions  We showed that Isomap provides a consistent methodical framework for both ordination and derived spatial filters. The technique is useful for tracing the often nonlinear features of species occurrence data to environmental drivers, taking into account anisotropic spatial autocorrelation. We also showed that sampling biases are a conspicuous source of variance in a frequently used floristic data base.
The methodological nettle: ICT and student achievement
Authors: Chandra Vinesh , Lloyd Margaret 
Published: February 2008

AbstractA major challenge for researchers and educators has been to discern the effect of ICT use on student learning outcomes. This paper maps the achievements in Year 10 Science of two cohorts of students over two years where students in the first year studied in a traditional environment while students in the second took part in a blended or e‐learning environment. Using both quantitative and qualitative methods, the authors have shown that ICT, through an e‐learning intervention, did improve student performance in terms of test scores. They have also shown that this improvement was not global with the results for previously high‐performing female students tending to fall while the results for lower‐achieving boys rose. There was also a seeming mismatch between some students' affective responses to the new environment and their test scores. This study shows the complexity of ICT‐mediated environments through its identification and description of three core issues which beset the credibility of research in ICT in education. These are (1) ICT as an agent of learning, (b) site specificity, and (c) global improvement.
Enhancing systems‐thinking skills with modelling
Authors: Hung Woei 
Published: February 2008

AbstractSystems thinking is an essential cognitive skill that enables individuals to develop an integrative understanding of a given subject at the conceptual and systemic level. Yet, systems thinking is not usually an innate skill. Helping students develop systems‐thinking skills warrants attention from educators. This paper describes a study examining the effects of utilising systems modelling as a cognitive tool in enhancing a group of graduate students' systems‐thinking skills. A significant improvement was observed in the systems‐thinking practises of the students. A theoretical rationale for enhancing systems‐thinking skills with modelling and the results of the study will be discussed.
Does the mode of delivery predispose women to anal incontinence in the first year postpartum? A comparative systematic review
Authors: Pretlove SJ , Thompson PJ , Toozs‐Hobson PM , Radley S , Khan KS 
Published: February 2008

Objectives  To assess if mode of delivery is associated with increased symptoms of anal incontinence following childbirth.Design  Systematic review of all relevant studies in English.Data sources  Medline, Embase, Cochrane Library, bibliographies of retrieved primary articles and consultation with experts.Study selection and data extraction  Data were extracted on study characteristics, quality and results. Exposure to risk factors was compared between women with and without anal incontinence. Categorical data in 2 × 2 contingency tables were used to generate odds ratios.Results  Eighteen studies met the inclusion criteria with 12 237 participants. Women having any type of vaginal delivery compared with a caesarean section have an increased risk of developing symptoms of solid, liquid or flatus anal incontinence. The risk varies with the mode of delivery ranging from a doubled risk with a forceps delivery (OR 2.01, 95% CI 1.47–2.74, P < 0.0001) to a third increased risk for a spontaneous vaginal delivery (OR 1.32, 95% CI 1.04–1.68, P = 0.02). Instrumental deliveries also resulted in more symptoms of anal incontinence when compared with spontaneous vaginal delivery (OR 1.47, 95% CI 1.22–1.78). This was statistically significant for forceps deliveries alone (OR 1.5, 95% CI 1.19–1.89, P = 0.0006) but not for ventouse deliveries (OR 1.31, 95% CI 0.97–1.77, P = 0.08). When symptoms of solid and liquid anal incontinence alone were assessed, these trends persisted but were no longer statistically significant.Conclusion  Symptoms of anal incontinence in the first year postpartum are associated with mode of delivery.
Nerve growth factor blocks thapsigargin‐induced apoptosis at the level of the mitochondrion viaregulation of Bim
Authors: Szegezdi E. , Reed Herbert K. , Kavanagh E. T. , Samali A. , Gorman A. M. 
Published: February 2008

AbstractThis study examined how the neurotrophin, nerve growth factor (NGF), protects PC12 cells against endoplasmic reticulum (ER) stress‐induced apoptosis. ER stress was induced using thapsigargin (TG) that inhibits the sarcoplasmic/ER Ca2+‐ATPase pump (SERCA) and depletes ER Ca2+ stores. NGF pre‐treatment inhibited translocation of Bax to the mitochondria, loss of mitochondrial transmembrane potential, cytochrome c release, activation of caspases (−3, −7 and −9) and apoptosis induction by TG. Notably, TG also caused a marked induction of Bimel mRNA and protein, and knockdown of Bim with siRNA protected cells against TG‐induced apoptosis. NGF delayed the induction and increased the phosphorylation of Bimel. NGF‐mediated protection was dependent on phosphatidylinositol‐3 kinase (PI3K) signalling since all above apoptotic events, including expression and phosphorylation status of Bimel protein, could be reverted by the PI3K inhibitor LY294002. In contrast, NGF had no effect on the TG‐mediated induction of the unfolded protein response (increased expression of Grp78, GADD34, splicing of XBP1 mRNA) or ER stress‐associated pro‐apoptotic responses (induction of C/EBP homologous protein [CHOP], induction and processing of caspase‐12). These data indicate that NGF‐mediated protection against ER stress‐induced apoptosis occurs at the level of the mitochondria by regulating induction and activation of Bim and mitochondrial translocation of Bax.
Narrative Methods and Children: Theoretical Explanations and Practice Issues
Authors: Bennett Lorna 
Published: February 2008

TOPIC:  The Narrative approach is an innovative way of working with children and adolescents experiencing mental health problems. This approach can be effectively integrated with the expressive arts and other nonverbal ways of accessing the life world of children. In addition, the approach promotes respect for and collaboration with the child in working towards healing and growth.PURPOSE:  In this paper core features of the narrative approach are described; the theoretical and philosophical and evidence base for this approach as well as its congruence with the special nature and needs of children will be explored. Finally, the benefits and challenges of this approach in relation to a specific clinical situation will be highlighted. SOURCES USED:  Published literature and the author's clinical experiences.CONCLUSION:  Narrative methods are ideally suited for addressing needs of children experiencing mental health problems and can enhance therapeutic effectiveness. Some of the challenges associated with its use include: finding creative ways to apply specific narrative concepts and methods with diverse clinical issues/problems; learning to collaborate with children and respect them as experts in their own lives; and shifting the nursing focus from a problem‐focused orientation to a strength‐oriented and child‐centered approach.
Speed of induction of anaesthesia in dogs administered halothane, isoflurane, sevoflurane or propofol in a clinical setting
Authors: Pottie RG , Dart CM , Perkins NR 
Published: February 2008

Objective To compare the speed and quality of induction of general anaesthesia using three different inhalant agents and one intravenous agent, in healthy dogs undergoing desexing surgery.Materials and methods Less excitable dogs were not premedicated; others were premedicated with intramuscular acepromazine and morphine. Anaesthesia induction protocol was randomly assigned, with halothane, isoflurane or sevoflurane delivered by mask, or propofol delivered intravenously. Maximum vaporiser settings were used for inhalant inductions. Induction of anaesthesia was considered complete at the time of endotracheal intubation. Quality of induction was scored by the administering veterinarian.Results Seventy‐one dogs were enrolled. Twenty‐four received no premedication and 47 received premedication. Isoflurane inductions were significantly faster than halothane inductions (2.86 ± 0.25 vs 3.71 ± 0.22 min; mean ± SE, P = 0.013). Sevoflurane inductions (3.29 ± 0.24 min) were not significantly different from either halothane (3.71 ± 0.22 min, P = 0.202) or isoflurane inductions (2.86 ± 0.25 min, P = 0.217). Induction with propofol (1.43 ± 0.13 min) was significantly faster than inhalant induction (P < 0.001 in each case). Premedication decreased the dose requirement and time to induction for dogs induced with propofol, but did not significantly change the time to intubation for inhalant inductions. Dogs administered propofol and/or premedication were significantly more likely to have an excellent quality of induction, but there was no difference between inhalant agents in terms of induction quality.Conclusion Sevoflurane possesses chemical properties that should produce a more rapid induction of anaesthesia in comparison to halothane or isoflurane. However, in clinical practice patient related factors outweigh this improvement.
Employing Satellite-Derived Sea Ice Concentration to Constrain Upper-Ocean Temperature in a Global Ocean GCM
Authors: Stössel Achim 
Published: February 2008

Abstract
The quality of Southern Ocean sea ice simulations in a global ocean general circulation model (GCM) depends decisively on the simulated upper-ocean temperature. This is confirmed by assimilating satellite-derived sea ice concentration to constrain the upper-layer temperature of a sea ice–ocean GCM. The resolution of the model’s sea ice component is about 22 km and thus comparable to the pixel resolution of the satellite data. The ocean component is coarse resolution to afford long-term integrations for investigations of the deep-ocean equilibrium response. Besides improving the sea ice simulation considerably, the simulations with constrained upper-ocean temperature yield much more realistic global deep-ocean properties, in particular when combined with glacial freshwater input. Both outcomes are relatively insensitive to the passive-microwave algorithm used to retrieve the ice concentration being assimilated. The sensitivity of the long-term global deep-ocean properties and circulation to the possible freshwater input from ice shelves and to the parameterization of vertical mixing in the Southern Ocean is reevaluated under the new constraint.
The Inverse Ocean Modeling System. Part I: Implementation
Authors: Bennett A. F. , Chua B. S. , Pflaum B. L. , Erwig M. , Fu Z. , Loft R. D. , Muccino J. C. 
Published: February 2008

Abstract
The Inverse Ocean Modeling (IOM) system constructs and runs weak-constraint, four-dimensional variational data assimilation (W4DVAR) for any dynamical model and any observing array. The dynamics and the observing algorithms may be nonlinear but must be functionally smooth. The user need only provide the model and the observing algorithms, together with an interpolation scheme that relates the model numerics to the observer’s coordinates. All other model-dependent elements of the Inverse Ocean Modeling assimilation algorithm (see both Chua and Bennett), including adjoint generators and Monte Carlo estimates of posteriors, have been derived and coded as templates in Parametric FORTRAN (Erwig et al.). This language has been developed for the IOM but has wider application in scientific programming. Guided by the Parametric FORTRAN templates, and by model information entered via a graphical user interface (GUI), the IOM generates conventional FORTRAN code for each of the many algorithm elements, customized to the user’s model. The IOM also runs the various W4DVAR assimilations, which are monitored by the GUI. The system is supported by a Web site that includes interactive tutorials for the assimilation algorithm.