bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geographical and environmental range expansion through polyploidy in wild potatoes (SolanumsectionPetota)
Authors: Hijmans Robert J. , Gavrilenko Tatjana , Stephenson Sarah , Bamberg John , Salas Alberto , Spooner David M. 
Published: March 2007

ABSTRACTAim To assess evidence for geographical and environmental range expansion through polyploidy in wild potatoes (Solanumsect.Petota). There are diploids, triploids, tetraploids, pentaploids and hexaploids in this group.Location Wild potatoes occur from the south‐western USA (Utah and Colorado), throughout the tropical highlands of Mexico, Central America and the Andes, to Argentina, Chile and Uruguay.Methods We compiled 5447 reports of ploidy determination, covering 185 of the 187 species, of which 702 determinations are presented here for the first time. We assessed the frequency of cytotypes within species, and analysed the geographical and climatic distribution of ploidy levels.Results Thirty‐six per cent of the species are entirely or partly polyploid. Multiple cytotypes exist in 21 species, mostly as diploid and triploid, but many more may await discovery. We report the first chromosome count (2n= 24) forSolanum hintonii. Diploids occupy a larger area than polyploids, but diploid and tetraploid species have similar range sizes, and the two species with by far the largest range sizes are tetraploids. The fraction of the plants that are polyploids is much higher from Mexico to Ecuador than farther south. Compared with diploids, triploids tend to occur in warmer and drier areas, whereas higher‐level polyploids tend to occur in relatively cold areas. Diploids are absent from Costa Rica to southern Colombia, the wettest part of the group's range.Main conclusions These results suggest that polyploidy played an important role in this group's environmental differentiation and range expansion.
The influence of learner characteristics on degree and type of participation in a CSCL environment
Authors: Prinsen Fleur , Volman Monique L.L. , Terwel Jan 
Published: March 2007

AbstractComputer‐Supported Collaborative Learning (CSCL) is often presented as a promising learning method. However, it is also facing some new challenges. Apart from answering the question of whether or not working with CSCL generates satisfying learning outcomes, it is important to determine whether or not all participants profit from collaboration, with the computer as a means of communication. This paper describes the implementation and effects of an experimental program in 5 classes with a total of 120 students in elementary education who, in groups of four, engaged in Knowledge Forum discussion tasks on the subject of healthy eating. The study explores whether or not differences occur in the participation of students who differ in gender, sociocultural background and ability, and whether or not computer skills, computer attitudes, comprehensive reading scores and popularity with classmates are related to student participation. Students' participation in this CSCL environment appears to be dependent on a number of learner characteristics. Girls contribute more words to the discussions than boys do and are more dependent on their computer skills in this production. Students who are good at comprehensive reading also contribute more words. Popularity among classmates appears to influence the degree of participation further. We also found indications that students with immigrant parents write fewer contributions than those whose parents are not immigrants.
The quest for deeper learning: an investigation into the impact of a knowledge‐pooling WebQuest in primary initial teacher training
Authors: Allan Jo , Street Mark 
Published: March 2007

AbstractThis paper explores the impact on learning in higher education of the integration of a knowledge‐pooling stage into a WebQuest. We explain the concept of WebQuests, consider recent literature regarding the effects and difficulties of this approach to learning, and examine students' perceptions of the impact of this tool on high‐order learning. The level of learning achieved by respondents is analysed using Biggs' Structure of the Observed Learning Outcomes (SOLO) taxonomy. With judicious use of a ‘pooling knowledge stage’, and provided that students are fully aware of the desired learning outcomes, the findings suggest that WebQuests do have the potential to promote high‐order learning. The paper concludes by suggesting the need for further research into the potential of WebQuests to promote high‐order learning within different disciplines in higher education.
A Network Model for Dispersion of Communicable Diseases
Authors: Bian Ling , Liebner David 
Published: March 2007

AbstractThe spread of communicable diseases through a population is an intrinsic spatial and temporal process. This paper presents an individual‐based analytical framework for modeling the spatial and temporal heterogeneity in the disease transmission. The framework specifies a network model structure and six associated parameters. These parameters describe the properties of nodes, the properties of links, and the topology of the network. Through this model structure and associated parameters, this framework allows the representation of discrete individuals, individualized interactions, and interaction patterns in a network of human contact. The explicit representation of the spatial distribution and mobility of individuals in particular facilitates the modeling of spatial heterogeneity in the disease transmission.
An Investigation into the Causes of Errors and Inconsistencies in Predicted Viewsheds
Authors: Riggs Philip D , Dean Denis J 
Published: March 2007

AbstractPrevious evaluations of viewshed analyses have raised concerns about the accuracy and repeatability of the process. Digital elevation model (DEM) errors, the limited spatial resolution of DEMs, and differing algorithms employed by different GIS packages have all been suggested as possible sources for inaccuracy and non‐repeatability. This study compared a field surveyed viewshed to predicted viewsheds generated using a variety of software packages and DEM databases, some of which contained known amounts of error. We found that each of the factors suggested by previous authors contributes to errors in predicted viewsheds. DEM errors contribute most to the discrepancies between surveyed and predicted viewsheds, and the majority of their negative impact occurred at very low levels of DEM error. Differing algorithms used by different GIS packages also contribute significantly to surveyed/predicted viewshed discrepancies, but more importantly, result in predicted viewsheds that disagree with one other, thereby confounding comparisons of results generated with differing software systems. Finally, the spatial resolution of DEMs also has a significant effect on the degree of agreement between surveyed and predicted viewsheds, but the magnitude of this effect is not as great as are the effects produced by DEM errors.
COMPARATIVE THEOLOGY AFTER LIBERALISM
Authors: NICHOLSON HUGH 
Published: March 2007

AbstractThis article first identifies two reasons for the current marginality of the theological sub‐discipline of “comparative theology.” The first is an awareness of the imperialistic character of the universalist (inclusivist and pluralist) theologies of the recent past. The second is the assumption that Christianity's relations with other religious are extrinsic to Christian identity. Drawing on Kathryn Tanner's critique of postliberalism, it argues that interreligious comparison is integral to a theology that recognizes the essentially relational nature of Christian identity. This recognition implies a continuous revision of Christian identity that checks the tendency to essentialize and thereby exclude religious “others.”
Morphology, locomotor behaviour and microhabitat use in North American squirrels
Authors: Essner R. L. 
Published: March 2007

AbstractThe rodent family Sciuridae (squirrels) presents an ideal system for examining the morphological, behavioural and ecological correlates of locomotor novelty. Ancestrally, sciurids were arboreal, a condition retained by modern tree squirrels. Two major transitions from the arboreal condition are hypothesized to have occurred in the sciurid clade: (1) flying squirrels evolved gliding from arboreal leaping (parachuting) and (2) chipmunks and ground squirrels became semiarboreal/terrestrial. This study examines morphology, locomotor behaviour and microhabitat use under controlled laboratory conditions in three North American sciurids: eastern chipmunkTamias striatus, red squirrelTamiasciurus hudsonicusand southern flying squirrelGlaucomys volans. Multivariate space was defined using a series of morphological measurements and by continuously sampling individuals moving under identical conditions in a naturalistic enclosure, controlling for the proximate effects of microhabitat structure. Morphospace was characterized by a contrast between proximal and distal limb elements – flying squirrels exhibited elongated forelimbs and shanks and shortened forefeet and hindfeet, while chipmunks exhibited the opposite pattern. Ethospace was characterized by a contrast between aerial locomotion in flying squirrels and ground‐based locomotion in chipmunks. In both instances, red squirrels occupied intermediate positions, as predicted on the basis of retention of ancestral features. Despite significant differences among species at morphological and behavioural levels, ecospace was characterized by overlap between flying squirrels and red squirrels in the use of high supports, and between flying squirrels and chipmunks in the use of large‐diameter supports. The lack of concordance at the ecological level underscores the difficulty in making predictions based solely upon organismal design.
The effects of running, environment, and attentional focus on athletes’ catecholamine and cortisol levels and mood
Authors: HARTE JANE L. , EIFERT GEORG H. 
Published: March 2007

AbstractThis study was designed to examine some of the psychoneuroendocrine effects of exercise‐induced emotional experiences and the mediating effects of environmental setting and subjects’ attentional focus. Trained runners were tested during an outdoor run and two indoor treadmill running conditions. Excretions of catecholamines and Cortisol significantly increased after all running conditions but not after a control condition. Results indicate that patterns of endocrine and concomitant emotional change through exercise differ when environmental setting and attentional focus are altered in such a way that a normally pleasant task such as running becomes tedious and negatively evaluated. These findings support the notion that setting, attention, and cognitive appraisal may alter the emotional experience associated with physical exercise.
Startle potentiation during anticipation of a noxious stimulus: Active versus passive response sets
Authors: PATRICK CHRISTOPHER J. , BERTHOT BRYAN D. 
Published: March 2007

AbstractThe startle reflex response increases during aversive stimulus processing. This study examined whether differing response sets affected startle potentiation during anticipation of an aversive event. Two groups received a noxious noise blast following a 6‐s warning cue. Subjects in the active group could press a switch to stop the noise; yoked passive subjects received the same noises with no control. Subjects in a yoked control group heard a soft tone following cue offset. Acoustic startle probes were presented during some of the warning periods and during some of the intertrial intervals. The major finding was that the active and passive groups did not differ in startle potentiation. In comparison with controls, startle reactions for both groups were larger and faster during the warning cue than between trials. The results suggest that the startle reflex indexes defensive response mobilization independently of specific task demands.
RISK, MEDICINE AND WOMEN: A CASE STUDY ON PRENATAL GENETIC COUNSELLING IN BRAZIL
Authors: GUILAM MARIA CRISTINA R. , CORRÊA MARILENA C.D.V. 
Published: March 2007

ABSTRACTGenetic counselling is an important aspect of prenatal care in many developed countries. This tendency has also begun to emerge in Brazil, although few medical centres offer this service. Genetic counselling provides prenatal risk control through a process of individual decision‐making based on medical information, in a context where diagnostic and therapeutic possibilities overlap. Detection of severe foetal anomalies can lead to a decision involving possible termination of pregnancy. This paper focuses on medical and legal consequences of the detection of severe foetal anomalies, mainly anencephaly and Down syndrome, and in light of the fact that abortion is illegal in Brazil. The discussion is based on the literature and empirical research at a high‐complexity public hospital in Rio de Janeiro.
Phosphorus balances for arable soils in Southern England 1986–1999
Authors: Heming S. D. 
Published: March 2007

AbstractThe behaviour of P in a range of English arable soils was examined by plotting the change in resin P in the topsoil (ΔPres) at the end of a 3‐ to 5‐year period, against the P balance over the same period (fertilizer P applied minus offtake in crops, estimated from farmers’ reported yields and straw removal). Based on the assumption that values for offtake per tonne of crop yield used for UK arable crops are valid averages, 20–60% of ΔPres was explained by the balance. Applying excess P fertilizer increased Pres, and reducing P fertilizer use decreased it; typically 3–4 kg P ha−1 was required for each mg L−1ΔPres (6–8 kg ha−1 for each mg L−1 of Olsen P). About half the P balance seems to be resin extractable and this differed little between soil groups, except in cases of very low P (index 0) in which the P buffering was stronger, and on very high P soils (index 4/5) when buffering was less. However, on calcareous soils and red soils, when fertilizer was applied in accord with offtake, Pres fell by up to 4 mg L−1 year−1 (2 mg L−1 yr−1 olsen P) and to prevent this an extra 3–10 kg P ha−1 year−1 fertilizer was required. But on most non‐calcareous soils, replacing offtake maintained Pres, with perhaps slight rises on soils of low clay content or greater organic matter content. In soils under arable rotations, the apparent recovery of P from fertilizer was often around 100%, falling to 85% on Chalk soils and 75% on medium–heavy soils on limestone or Lower Chalk. The fate of the ‘missing’ P needs clarification. The case for corrections to current P fertilizer recommendations in the UK on certain soil types is discussed.
Impact of grazed grassland management on total N accumulation in soil receiving different levels of N inputs
Authors: Watson C. J. , Jordan C. , Kilpatrick D. , McCarney B. , Stewart R. 
Published: March 2007

AbstractNitrogen balances and total N and C accumulation in soil were studied in reseeded grazed grassland swards receiving different fertilizer N inputs (100–500 kg N ha−1 year−1) from March 1989 to February 1999, at an experimental site in Northern Ireland. Soil N and C accumulated linearly at rates of 102–152 kg N ha−1 year−1 and 1125–1454 kg C ha−1 year−1, respectively, in the top 15 cm soil during the 10 year period. Fertilizer N had a highly significant effect on the rate of N and C accumulation. In the sward receiving 500 kg fertilizer N ha−1 year−1 the input (wet deposition + fertilizer N applied) minus output (drainflow + animal product) averaged 417 kg N ha−1 year−1. Total N accumulation in the top 15 cm of soil was 152 kg N ha−1 year−1. The predicted range in NH3 emission from this sward was 36–95 kg N ha−1 year−1. Evidence suggested that the remaining large imbalance was either caused by denitrification and/or other unknown loss processes. In the sward receiving 100 kg fertilizer N ha−1 year−1, it was apparent that N accumulation in the top 15 cm soil was greater than the input minus output balance, even before allowing for gaseous emissions. This suggested that there was an additional input source, possibly resulting from a redistribution of N from lower down the soil profile. This is an important factor to take into account in constructing N balances, as not all the N accumulating in the top 15 cm soil may be directly caused by N input. N redistribution within the soil profile would exacerbate the N deficit in budget studies.
Pushing boundaries in paediatric intensive care: training as a paediatric retrieval nurse practitioner
Authors: Davies Jo , Lynch Fiona 
Published: March 2007

AbstractTraditionally in the UK, the transportation of the critically ill child to a paediatric intensive care unit has been carried out by a medically led team of doctors and nurses. However, in countries such as the USA and Canada, appropriately trained nurse practitioners have proven to be competent in the transportation of these vulnerable children. This nurse‐led team model has also been shown to be successful in the speciality of neonatal care in the UK. The impact of changes in the National Health Service (NHS) has led to an increased demand for the transportation of the child requiring paediatric intensive or high‐dependency care, the lifting of restrictions on nursing practice and the reduction of doctors’ hours in keeping with the European Working Time Directive. This has led to one NHS Trust in the UK developing the role of paediatric retrieval nurse practitioners (RNP): nurses who lead the retrieval team. The purpose of this article is to describe a pilot initiative to develop the role of RNPs. The comprehensive process of recruitment, training and assessment of competency will be detailed. Personal reflection on the project will also explore the pertinent nursing issues around; role impact and definition, conflict and change management, communication, legislation and personal and professional growth. Recommendations for future initiatives will also be explored.
An audit of ward nurses’ knowledge of sepsis
Authors: Robson Wayne , Beavis Sarah , Spittle Nick 
Published: March 2007

AbstractMany of the patients with sepsis admitted to intensive care and high dependency units develop severe sepsis/septic shock in general hospital wards. If the Surviving Sepsis Campaign’s aim of a 25% reduction in mortality from sepsis is to be achieved by 2009, then it is essential that registered nurses are aware of the standard definitions of sepsis, and the recommendations for its initial management. The aim of this study was to audit ward nurses’ knowledge of sepsis against standard definitions and evidence‐based management guidelines. An audit was carried out in one acute hospital to assess ward nurses’ knowledge of sepsis. Seventy‐three registered nurses from medical, surgical and orthopaedic wards completed a questionnaire about the signs and symptoms of sepsis and its initial management. The results showed that some ward nurses appeared to have a poor knowledge of the signs and symptoms of sepsis, severe sepsis/septic shock and some aspects of its initial management. Following the results of the audit, a variety of educational initiatives were introduced to raise awareness of the standard definitions and the surviving sepsis management guidelines. In conclusion, targeted education must be provided for nurses working in general wards if the Surviving Sepsis Campaign is to achieve its aim of a 25% reduction in mortality by 2009.
Life history and host‐plant relationships of the rare endemic Arctic aphid Acyrthosiphon calvulus in a changing environment
Authors: Gillespie Mark , Hodkinson Ian D. , Cooper Elisabeth J. , Bird Jeremy M. , Jónsdóttir Ingibjörg S. 
Published: March 2007

AbstractThis article examines the abundance, life history, host‐plant relationships, and overwintering biology of Acyrthosiphon calvulus Ossiannilsson (Homoptera: Aphididae) as a precursor to understanding its rarity and potential response to a changing climate. Acyrthosiphon calvulus is restricted to a few scattered localities on the west coast of Spitsbergen, Svalbard, Norway, where it reproduces on Salix polaris WG (Salicaceae) and its taxonomically unrelated root parasite Pedicularis hirsuta L. (Scrophulariaceae). Acyrthosiphon calvulus overwinters as eggs. Hatching fundatrices give rise directly to males and oviparae, which mate and lay overwintering eggs. The life cycle is closely synchronized with the phenology of S. polaris and appears genetically programmed, lacking summer generations of viviparae. Alate forms are similarly unknown. The progeny sequence of fundatrices resulted in a sex ratio for the sexuales that is strongly female biased (3:1). Eggs hatch coincided with budburst in early June and fundatrices developed on the expanding leaves. Egg production by oviparae corresponded with leaf senescence in July and August. Overwintering egg survival was high, with supercooling points ranging from −29 to −40 °C, lower than the extreme winter minimum temperature recorded (−28 °C). Egg development and hatching occurred at or below 5 °C and sub‐zero temperatures were not required to break diapause. The scarcity and fragmented distribution of A. calvulus is discussed in the context of the ubiquity of its host plants on Spitsbergen.
A possible role of thymidine phosphorylase expression and5‐fluorouracil increased sensitivity in oropharyngeal cancer patients
Authors: Ranieri G. , Grammatica L. , Patruno R. , Zito A.F. , Valerio P. , Iacobellis S. , Gadaleta C. , Gasparini G. , Ribatti D. 
Published: March 2007

AbstractThymidine Pi deoxyribosyltransferase (TP) is an enzyme involved in DNA synthesis up‐regulated in tumours and it is also a pro‐angiogenic factor. TP cannot activate capecitabine, because capecitabine first needs conversion by carboxylesterase and cytidine deaminase into 5‐deoxy‐fluorouridine. This compound can be activated by TP to 5‐fluorouracil (5‐FU). Although TP is not necessary for 5‐FU toxicity, experimental data suggest that high levels of TP correlate with an enhanced response to 5‐FU therapy. In this study, we have analysed by immunohistochemistry CD34, CD68 and TP positive cells in bioptic samples from 53 patients with T1–3 N0–1 M0 oropharyngeal squamous cell carcinoma (OSC) and from 24 patients with non‐dysplastic oropharyngeal leukoplakia (NDOLP). Results showed that the mean of TP‐positive cells, CD68 positive macrophages and CD34 positive endothelial cells eval‐uated as microvessel density (MVD) was significantly higher in OSC than in NDOLP. Moreover, at a median follow‐up of 19 months, patients with TP expression and higher MVD showed a better survival rate as compared to those with low MVD, probably as a consequence of 5‐FU‐based therapy.We hypothesized a role for TP in oropharyngeal tumourigenesis and 5‐FU activation in the adjuvant setting of OSC patients.
Expression of OePIP2.1 aquaporin gene and water relations of Olea europaea twigs during drought stress and recovery
Authors: Secchi F. , Lovisolo C. , Schubert A. 
Published: March 2007

AbstractTo investigate the effects of drought and recovery on the transcript level of OePIP2.1 (a PIP2 aquaporin gene) in twigs, 2‐year‐old olive trees were subjected to a drought/rewatering treatment (the irrigation was suspended for a period of 4 weeks and restored for the following 4 weeks). Twig water potential, twig hydraulic resistance and incidence of embolisation in the twig were measured in parallel with gene expression under both drought stress and the following recovery. During drought, a decrease in twig water potential, an increase in twig hydraulic resistance and an increase in the extent of xylem vessel embolisation was observed in parallel with a decrease of aquaporin gene expression. Opposite trends were recorded during rewetting. A speculation on a possible contribution of OePIP2.1 aquaporin to modulate shoot embolism during drought and recovery is proposed.