bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tissue-Specific Gene Silencing Mediated by a Naturally Occurring Chalcone Synthase Gene Cluster inGlycine max [W]
Authors: Tuteja Jigyasa H. , Clough Steven J. , Chan Wan-Ching , Vodkin Lila O. 
Published: April 2004

AbstractChalcone synthase, a key regulatory enzyme in the flavonoid pathway, constitutes an eight-member gene family in Glycine max (soybean). Three of the chalcone synthase (CHS) gene family members are arranged as inverted repeats in a 10-kb region, corresponding to the I locus (inhibitor). Spontaneous mutations of a dominant allele (I or ii) to a recessive allele (i) have been shown to delete promoter sequences, paradoxically increasing total CHS transcript levels and resulting in black seed coats. However, it is not known which of the gene family members contribute toward pigmentation and how this locus affects CHS expression in other tissues. We investigated the unusual nature of the I locus using four pairs of isogenic lines differing with respect to alleles of the I locus. RNA gel blots using a generic open reading frame CHS probe detected similar CHS transcript levels in stems, roots, leaves, young pods, and cotyledons of the yellow and black isolines but not in the seed coats, which is consistent with the dominant I and ii alleles mediating CHS gene silencing in a tissue-specific manner. Using real-time RT-PCR, a variable pattern of expression of CHS genes in different tissues was demonstrated. However, increase in pigmentation in the black seed coats was associated with release of the silencing effect specifically on CHS7/CHS8, which occurred at all stages of seed coat development. These expression changes were linked to structural changes taking place at the I locus, shown to encompass a much wider region of at least 27 kb, comprising two identical 10.91-kb stretches of CHS gene duplications. The suppressive effect of this 27-kb I locus in a specific tissue of the G. max plant represents a unique endogenous gene silencing mechanism.
Local Markets and the Polarization of Public‐Sector Schools in England and Wales
Authors: Gibson Alex , Asthana Sheena 
Published: March 2004

Notwithstanding the recent change of government, UK educational policy continues to stress school performance tables, parental choice and competition – reflecting an acceptance by New Labour of Tory notions concerning the role that market mechanisms play in improving school performance. In view of the 1997 Education White Paper's insistence that the new government's goal was to ‘overcome the spiral of disadvantage … passed from one generation to the next’, this implies that the DfEE remains unimpressed by long‐standing arguments concerning the socially‐divisive consequences of market forces in education.This paper seeks to add empirical weight to this debate. Arguing that recent analyses of aggregate levels of social stratification have masked polarization occurring at the local level, our analysis places schools in the context of the local markets within which they operate. This yields clear evidence that educational markets tend to exacerbate existing differences between schools in terms of both their performance and social status.
Ratio dependence in the functional response of insect parasitoids: evidence fromTrichogramma minutumforaging for eggs in small host patches
Authors: Mills N. J. , Lacan I. 
Published: April 2004

Abstract. 1. Despite considerable recent debate on the suitability of ratio dependence as a more general form for the functional response in consumer–victim relationships, there have been few detailed studies to experimentally determine the response of insect parasitoids to host and parasitoid density at a local scale.2. The experimental host,Ephestia kuehniella, was used to test for host dependence and ratio dependence in the functional response of the egg parasitoid,Trichogramma minutum, a species widely used in inundative biological control. The functional response was examined through four series of experiments in which either host density, parasitoid density, or the ratio of previously parasitised to healthy hosts was manipulated.3. The response to host density was type I for both single and simultaneously foraging parasitoids, indicating a lack of host dependence in the functional response. The upper limit to the response was estimated as 39 hosts attacked in a 24‐h period, with an estimated per capita search rate of 1.32 for individual females and 0.37 for three simultaneously searching females.4. The response to parasitoid density provided an interference constant of unity, indicating an equal sharing of hosts and thus ratio dependence in the functional response. Female parasitoids responded to the presence of conspecifically parasitised eggs with a significant increase in search rate (1.75), but with no change to the form or upper limit of the response.5. It is suggested that ratio dependence may be more common among insect parasitoids than previously supposed, and that a type I functional response, or the absence of host dependence, may be an emergent property of phylogenetic constraint within the monophyletic grouping ofCales,Eretmocerus, andTrichogramma.
Rank Order of Success Favors Longer Duration of Imidazole‐Based Therapy for Helicobacter pylori in Duodenal Ulcer Disease: A Randomized Pilot Study
Authors: Chaudhary Ashmit , Ahuja Vineet , Bal Chandrasekhar S. , Das Bimal , Pandey Ravinder Mohan , Sharma Mahesh Prakash 
Published: April 2004

ABSTRACTBackground.  Studies on eradication therapy in developing countries have shown a success rate of 70–85%, which is suboptimal. Duration of therapy may be an important factor dictating eradication success in such regions.Aim.  The study was undertaken to evaluate the effect of increasing the treatment period on eradication of Helicobacter pylori in duodenal ulcer disease.Methods.  A randomized trial was carried out in which 64 consecutive H. pylori‐infected patients with duodenal ulcer disease were enrolled. The patients were randomized to one of the three trial arms. Therapy consisted of lansoprazole 30 mg twice a day (b.i.d.), amoxycillin 1 g b.i.d. and tinidazole 500 mg b.i.d. The treatment period was 1 week in group I, 2 weeks in group II and 3 weeks in group III. At inclusion, patients underwent endoscopy and the presence of H. pylori was documented by a positive urease test and C14 urea breath test. Four weeks after completion of eradication therapy, the patients were subjected to repeat endoscopy to assess ulcer healing and tests for H. pylori infection.Results.  Sixty‐four patients (55 male and nine female; mean age 35.5 years) were enrolled in each group. The H. pylori eradication rate for group I (1 week of therapy) was 47.6%, that for group II (2 weeks of therapy) was 80%, and that for group III (3 weeks of therapy) was 91.3% (p = .003). The ulcer healing rates were 71.4, 80 and 95.6% in groups I, II and III, respectively (p = .09).Conclusion.  The 3‐week regimen significantly improved the eradication rate as compared with the 1‐week regime. Increasing the duration of therapy significantly improved the chances of eradication of H. pylori in duodenal ulcer disease.
New Books on Darwinism Look at the Religious and Rhetorical Aspects of Evolutionary Theory
Authors: Anderson Owen 
Published: April 2004

Darwin's Proof: The Triumph of Religion Over Science, Cornelius Hunter, Brazos Press 2003 (1‐58743‐056‐8), pp. 168, Hb $17.99 Doubts About Darwin: A History of Intelligent Design, Thomas Woodward, Baker Books 2003 (0‐8010‐6443‐0), pp. 303, Hb $19.99
Reflective practice and clinical supervision: an interprofessional perspective
Authors: Clouder Lynn , Sellars Julie 
Published: April 2004

Background.  In the United Kingdom, the drive to encourage reflective practice through clinical supervision, as a means of ensuring quality of provision in nursing and other health care professions, is now well‐embedded, not only in policy but also in practice. However, debate and critique of these concepts is limited.Aim.  The aim of this paper is to draw on research, conducted with undergraduate occupational therapy students and qualified physiotherapists, in order to contribute to the debate about the functions of clinical supervision and reflective practice in nursing and other health care professions.Discussion.  Upholding the notion that clinical supervision has the potential to constitute a form of surveillance, we counter the assumption that it is inevitably confessional in nature. A social constructionist perspective is used to illustrate how clinical supervision might involve a complex interplay of factors that dispel notions of predictability, control and rationality.Conclusion.  Despite acknowledging tensions, we argue that clinical supervision is both necessary and beneficial. It can be advantageous to individual practitioners and professional groups in enhancing practice and accountability, and promoting professional development.
Registered Nurses’ work experiences: personal accounts integrated with professional identity
Authors: Fagerberg Ingegerd 
Published: April 2004

Background.  The work context is important for the development of Registered Nurses’ skills and identity as professionals, but the work context and organization can also hinder their professional development.Aim.  This paper reports a study whose purpose was to understand the meaning of Registered Nurses’ narratives of their work experience 5 years after graduation.Research method.  Data were collected in 2001 from interviews with 16 Registered Nurses 5 years after graduation and analysed using a phenomenological hermeneutic method, influenced by the philosophy of Paul Ricoeur.Results.  Analyses of the narratives resulted in three themes: ‘The meaning of caring and protection of patients’, ‘The meaning of work organization in nurses’ work’ and ‘The implied meaning of using one's individual attributes in one's professional role’. Since the number of nurses participating in the study is small, it is important to re‐contextualize the results when transferring them to other contexts.Conclusions.  There is a complex interrelationship between the health care organization, individual attributes of nurses (including self‐esteem) and patient care. Provision of adequate resources and support for nurses’ professional and personal development is needed to ensure high quality patient care, and these are political issues.
The smacking controversy: what advice should we be giving parents?
Authors: Taylor Julie , Redman Susan 
Published: April 2004

Background.  Even among countries that have ratified the United Nations Convention on the Rights of the Child there is much disagreement about corporal punishment of children. Last year the Scottish Executive proposed a new law banning the smacking of children under the age of three, becoming the tenth European nation to do so. The proposal, currently abandoned whilst ostensibly still under debate, has raised a wave of controversy in child protection circles. In the nearest neighbouring country, England, a similar proposal was robustly rejected.Purpose of the paper.  Given an increasing family and community focus in nursing, the implications of the debate for the profession cannot be ignored. What should we be telling ‘ordinary’ families about smacking? Thus this paper presents a positional statement on the smacking controversy and outlines some pointers for practice.Discussion.  While for many the legislation proposed does not go far enough, others decry it as a breach of parental rights and, thus, the issue has become hugely controversial. Media opinion and various opposing campaigns dominate both public and professional spheres. Rights, responsibilities, examples from other countries, culture and gender are all used as fodder in the debate. Extreme examples are cited by both sides and used as grist for what are at times tenuous arguments. As there is even a division within child protection arenas, practising professionals may struggle to find a way through the maze of seemingly contradictory findings from research, policy and opinion.Conclusions.  A wide range of literature suggests that both public and professional opinion is divided on the use of smacking as a form of discipline of young children. Opinion is also divided on the ability of legislation to bring about change in social attitudes and behaviour. Health care professionals need to be in a position to recommend best practice and to do so consistently.
Evaluating system‐based strategies for managing conflict in collaborative concept mapping
Authors: Chiu C.‐H. 
Published: April 2004

AbstractThis study examined the influence of various conflict management mechanisms embedded into computer‐supported collaborative concept mapping systems on the behaviour and learning of elementary students. Four conflict management mechanisms were compared: an assign design, in which the mapping control was designated to a particular group member; a rotate design, in which the mapping control was rotated among the group members; a give design, in which the child with mapping control could relinquish control to another group member; and an open design, in which every group member simultaneously had mapping control. Ninety‐six fifth and sixth grade Taiwanese students participated in this study. They were arranged into assign, rotate, give, or open three‐member groups to generate collaboratively shared concept maps. Student interactions, attitudes, and achievement were analysed. The results suggest that each conflict management mechanism has a different effect on the elementary students.
In search of online pedagogical models: investigating a paradigm change in teaching through the School for All community
Authors: Young S. S.‐C. 
Published: April 2004

AbstractFollowing a preliminary evaluation of the Web‐mediated School for All in 2002, this study further examines the online teacher role and explores the possible pedagogical models in this Web‐based informal lifelong learning context through a long‐term innovative e‐learning project over a 2‐year period. The author documents the educational rationale, reviews related literature on Web‐based instructional design, and presents longitudinal in‐depth study results based on empirical data collected from the four Web‐course contests held over 2 years from the perspective of outstanding online teachers. Significantly, three categories of six Web‐based pedagogical models induced from this research project are presented, and the rationale for how and why teachers would prefer to use certain teaching models is discussed. In addition, the characteristics of the outstanding online teachers and issues inherent in this alternative mode of a Web‐based informal educational setting are discussed. Finally, more research issues, questions, and possibilities for future research work are raised or identified for further study.
Cognitive, social, motivational and health aspects of students in laptop classrooms
Authors: Trimmel Michael , Bachmann Julia 
Published: April 2004

AbstractEffects on cognitive performance, social atmosphere, communication, motivation and aspects of strain were investigated when laptops were integrated in classrooms. According to a quasi‐experimental design 27 laptop students were compared with 22 non‐laptop students from the same high school, aged 17–18 years. Results of tests and questionnaires showed that laptop students had better spatial abilities and computer skills, furthermore higher participation, learning interest, motivation and pressure to perform were found in laptop classrooms. However, laptop students experienced greater physical discomfort, particularly in their arms, but concerning creativity, social intelligence and mental stress no group differences occurred. Results indicate that laptops integrated in teaching can enhance learning and motivation in schools, at least after 1.7 years of introduction, but health risks must be considered.
Indirect evidence that frugivorous birds track fluctuating fruit resources among rainforest patches in the Northern Territory, Australia
Authors: Price Owen Francis 
Published: April 2004

Abstract  Rainforests are naturally fragmented in the Northern Territory of Australia. A census of fruit and frugivorous bird abundance was taken monthly in 10 rainforest patches for 1 year and quarterly for a second year to investigate spatial and temporal patterns among the patches. Fruit abundance showed a marked annual cycle, with a peak around December in the wet season. Four of six bird species showed a significant seasonal fluctuation in abundance, and for three of them, these patterns were different among rainforest types. Three species also showed a significant tendency to be most abundant in the rainforest type with the most fruit in any month. We interpret these results as evidence that birds track fruit resources among rainforest patches of different types. The abundance of two of the species (figbird and pied imperial‐pigeon) was highly variable and did not reveal significantly different temporal trends among rainforest types. These species are probably even more mobile than the other species, although the data in the present study cannot be used to test this theory. The conservation of frugivorous birds and of the plants whose seeds they disperse will require the protection of networks of rainforest patches.
Response of vegetation and vertebrate fauna to 23 years of fire exclusion in a tropical Eucalyptus open forest, Northern Territory, Australia
Authors: Woinarski J. C. Z. , Risler J. , Kean L. 
Published: April 2004

Abstract  This opportunistic study compares the vegetation, fuel loads and vertebrate fauna of part of a 120‐ha block of tropical open forest protected from fire for 23 years, and an adjacent block burnt annually over this period. Total fuel loads did not differ significantly between the unburnt and annually burnt sites, but their composition was markedly different, with far less grassy fuel, but far more litter fuel, in the unburnt block. There were major differences between treatments in the composition of trees and shrubs, manifest particularly in the number of stems. There was no overall difference in plant species richness between the two treatments, but richness of woody species was far higher in the unburnt treatment, and of annual and perennial grasses, and perennial herbs in the annually burnt treatment. Change in plant species composition from annually burnt to unburnt treatment was directional, in that there was a far higher representation of rainforest‐associated species (with the percentage of woody stems attributable to ‘rainforest’ species increasing from 24% of all species in the annually burnt treatment to 43% in the unburnt treatment, that of basal area from 9% to 30%, that of species richness from 8% to 17%, and that of cover from 12 to 47%). The vertebrate species composition varied significantly between treatments, but there was relatively little difference in species richness (other than for a slightly richer reptile fauna in the unburnt treatment). Again, there was a tendency for species that were more common in the unburnt treatment to be rainforest‐associated species. The results from this study suggest that there is a sizeable and distinct set of species that are associated with relatively long‐unburnt environments, and hence that are strongly disadvantaged under contemporary fire regimes. We suggest that such species need to be better accommodated by fire management through strategic reductions in the frequency of burning.
Breeding system, pollination and demography in the rare granite endemic shrub Verticordia staminosa ssp. staminosa in south‐west Western Australia
Authors: Yates Colin J. , Ladd Philip G. 
Published: April 2004

Abstract  Verticordia staminosa C. Gardner & A. S. George staminosa (Myrtaceae) is a rare granite endemic shrub that grows in discrete subpopulations on one isolated rock outcrop in a remnant of native vegetation in the Western Australian wheat belt. Key considerations in assessing the risk of extinction for rare plant species in fragmented landscapes are the reproductive dependence on a pollinator, breeding system, importance of seeds in demography, and regeneration niche. The present study determined the extent to which these factors constrain population growth in V. staminosa ssp. staminosa. Measurements across nine subpopulations on the breeding system, pollinator activity, rates of flowering, pollination and seed production, seedling demography, mature plant mortality and size‐class structure were undertaken over three consecutive years. The study species has a mixed mating system with similar rates of pollen tube development and fertilization observed in self‐, cross‐ and open‐pollinated flowers. Floral morphology, orientation and the concentration and volume of nectar produced suggest some degree of specialization associated with pollination by birds, which were occasionally seen visiting flowers. However, feral honey bees were the most commonly observed flower visitor and they seem to have replaced honeyeaters as the primary pollinator. Honey‐bee abundance increased with subpopulation size. However, rates of pollination and the subsequent proportion of flowers that produced viable seeds were independent of subpopulation size. Germination and seedling emergence occurred each winter but were greatest in the wettest winter. Recruitment was heavily biased towards individuals growing in or over cracks/fissures in the rock. Over the 3‐year study, recruitment exceeded mortality. A relatively unspecialized flower and mixed mating system have buffered the taxon against the effects of pollinator disruption. Seed production does not constrain population growth. The environmental variables of climate and suitable establishment crevices appear to be the major constraints to population growth.
Below‐ground biomass and productivity of a grazed site and a neighbouring ungrazed exclosure in a grassland in central Argentina
Authors: Pucheta Eduardo , Bonamici Ivano , Cabido Marcelo , Díaz Sandra 
Published: April 2004

Abstract  We estimated the below‐ground net plant productivity (BNPP) of different biomass components in an intensively and continuously 45‐ha grazed site and in a neighbouring exclosure ungrazed for 16 years for a natural mountain grassland in central Argentina. We measured approximately twice as much dead below‐ground biomass in the grazed site as in the ungrazed site, with a strong concentration of total below‐ground biomass towards the upper 10 cm of the soil layer in both sites. The main contribution to total live biomass was accounted for by very fine (<0.5 mm) and fine roots (0.5–1.0 mm) both at the grazed (79%) and at the ungrazed (81%) sites. We measured more dead biomass for almost all root components, more live biomass of rhizomes, tap roots and bulbs, and less live biomass of thicker roots (>1 mm) in the grazed site. The seasonal variation of total live below‐ground biomass mainly reflected climate, with the growing season being limited to the warmer and wetter portion of the year, but such variation was higher in the grazed site. Using different methods of estimation of BNPP, we estimated maximum values of 1241 and 723 g m−2 year−1 for the grazed and ungrazed sites, respectively. We estimated that very fine root productivity was almost twice as high at the grazed site as at the ungrazed one, despite the fact that both sites had similar total live biomass, and root turnover rate was twofold at the grazed site.