bluuebunny/crossref_metadata_2025 huggingface dataset:
Religion, Equity and Education in Northern Ireland
Authors: Gallagher A. M. , Cormack R. J. , Osborne R. D.
Published: June 2007

For some years concern has been expressed about the lower qualifications of leavers from Catholic schools in Northern Ireland in comparison with leavers from Protestant schools. The paper outlines research carried out for the Standing Advisory Commission on Human Rights on possible contributory factors to this attainment gap. The research highlighted the effects of different funding arrangements for Catholic schools and a shortage of grammar school places in the Catholic sector, and recommended proactive measures by government to deal with these issues. The recommendations were based on equity principles and were argued as being consistent with declared government policy on fair employment in Northern Ireland on religious grounds. Following the research findings the Government announced extra funds to increase grammar school provision in Catholic schools and changed the arrangements for capital grants to permit Catholic schools to receive 100% grant. The paper suggests that the application of equity principles in this case may be relevant to the issue of denominational schools in Britain.
Teacher and Pupil Interactions and the Processes of Mathematical Instruction in Four Reception Classrooms over Children's First Year in School
Authors: Aubrey Carol
Published: June 2007

This paper will describe the way mathematical knowledge is presented and how it is understood by teachers and children in reception classroom contexts. Particular reference will be made to an exemplar, data handling lesson provided by each of the four teachers involved. The main focus will be placed on gathering and coding data and the patterns of interaction which emerged. Teacher and pupil interactions were recorded in four reception classes across children's first year at school. The emerging structure was one of co‐ordinating segments and subsegments which provided the ‘warp’ of lessons. Segments usually consisted of small group tasks and each had its own goals and actions. Analysis of lesson segments and subsegments into components, which carried implications for teacher and pupil actions, allowed access to recurrent patterns of teacher moves, or the ‘weft’ of lessons. Components comprised: introduction, tutoring and guiding, helping in task execution, monitoring and assessing, reviewing or commenting on results or outcomes. Not all segments contained all elements and individual teachers had their own distinctive styles of working. The amount of time in which there was opportunity to engage in mathematical tasks varied as well as the number of children involved and the quality of experience provided. Teacher talk and support varied from the irrelevant and goal‐free beset by management problems, through modelling, ‘talk aloud’ strategies with coaching and monitoring, to the more formal exposition with structured initiation‐response‐evaluation sequences. Rich teacher knowledge appeared to be reflected in the context and structure of lessons, in explicit and well‐integrated instruction, varied representations with links or connections made to existing skills and understanding. Results based on so small a sample of lessons, however, can be only suggestive of what a more extensive study of classroom processes might find.
Qualitative Research, Professional Development and the Role of Teacher Educators: fitness for purpose
Authors: Day Christopher W.
Published: June 2007

This paper focuses upon the purposes, prejudices, practices and contexts of those who teach education in all its forms within higher education and schools. It examines some of the difficulties and challenges those in education departments whose significant history is school teaching face in extending their own learning opportunities as part of their moral purposes as professionals engaged in the ‘betterment’ of education, and it will suggest routes for research which might contribute to their thinking and action and thus, ultimately, to the education of students and pupils. There are, of course, examples of tutors in higher education engaging in development through ‘reflective practice’ and of pre‐service teacher education courses which are based upon notions of reflective practice. The purpose of this paper, however, is to examine the roles and responsibilities of teacher educators through an analysis of their historical, social and psychological contexts and, through this, to propose a particular partnership model of qualitative research and development which appears to ‘fit’ closely to purpose.
Are Pupils Equipped for Group Work without Training or Instruction?
Authors: Mcallister Wendy
Published: June 2007

This account of teacher practical research examines the question of whether pupils need instruction about how to operate effectively in groups. It is taken for granted that pupils ‘know’ how to ‘work’ in groups and that teachers need only set it up and give directions to groups for successful outcomes. The author organises ‘work’ in groups and observes and evaluates the outcomes. Her conclusions are that many factors impinge on the success of groupwork as outlined in the paper and indicate the importance of teachers taking time to discover inter‐relationships and other factors in the social framework of teaching that can overcome barriers to successful teaching. The account is self‐challenging and reflective.
No Entry Signs: educational change and some problems encountered in negotiating entry to educational settings
Authors: Troman Geoff
Published: June 2007

The difficulties involved in gaining entry to educational settings in order to carry out ethnographic fieldwork have been known for some time. Previous accounts, however, have stressed the importance of the researcher's self and field relations in the micro‐context in influencing the entry process. This article argues that in a time of rapid change in education the impact of the recent changes on participants, in particular, gatekeepers, shapes their responses to access requests from ethnographers. This argument is developed using data derived from the author's unsuccessful attempts to gain entry for ethnographic research in several English primary schools. The article concludes by suggesting that getting in is getting harder, and ethnographers, in developing successful strategies to gain entry, must develop a reflexivity informed by knowledge of structure and the macro‐context in which their negotiations take place.
The Value of School Locations
Authors: Conduit E. , Brookes R. , Bramley G. , Fletcher C. L.
Published: June 2007

A method for assessing schools’ performance in relation to socio‐economic indicators of their location is described. A substantial proportion of the variance in General Certificate of Secondary Education (GCSE) results is accounted for by indicators such as the percentage of owner‐occupied houses in the area around the school. The addition of car ownership, unemployment, and overcrowding to give a composite normalised score known as the Townsend Index accounted for more than half the variance in the GCSE results of two West Midlands local education authorities (LEAs). The results are critically discussed.
Bourdieu and Initial Teacher Education‐a post‐structuralist approach
Authors: Grenfell Michael
Published: June 2007

This paper details an application of the work of the French social theorist Pierre Bourdieu to research on initial teacher education. The extent to which Bourdieu's work is post‐structuralist is discussed; his major theoretical perspectives are outlined; and their relevancy outside of the purely sociological argued for. An example of research method derived from his approach is offered as a practical illustration: the training of modern language teachers. The method is based on a three‐level analysis which links notions of individual pedagogic habitus to the training field. Some detail is given of ‘mapping the field’ of training, and structural, differential responses of students within it. Training is considered as ‘discourse’, as a field of knowledge(s) and practice(s), and the policy implications of this approach discussed. Comments are made on the epistemological nature of the method employed and its scope for future research practice.
Assessing Students' Ability to Use Computers: theoretical considerations for practical research
Authors: Selwyn Neil
Published: June 2007

The assessment of students' ability to use computers should be a central tenet of educational computing research, but until now most studies have relied on vague and imprecise definitions of what actually constitutes being able to use a computer. More often than not researchers are content to accept a self‐evaluation from the student, often in the form of a response to a single question, and even the more elaborate attempts to measure ability have proved too narrow or ill‐focused to be of lasting value. This paper argues that before attempting to assess computer ability the overall nature of the concept should first be considered. From this, a theoretical framework of ability can then be constructed on which to base subsequent practical assessment. The paper also raises methodological issues to be considered by future research into students' use of computers.
Being a Professional in Schools and Universities: limits, purposes and possibilities for development
Authors: Day Christopher
Published: June 2007

This paper, an edited version of the Lawrence Stenhouse Memorial Lecture, argues that if the kinds of emancipation and empowerment envisaged by Stenhouse for students in schools are to be practised, educators in universities and other educational organisations must recognise and assert that they are a part of rather than apart from a broader social, economic and political dialogue in which teachers, teachers’ associations, parents, governors, local education authorities and policymakers in other places are engaged. As professional researcher‐developers still with ‘room to manoeuvre’ within and without politically driven policy agendas, they have a legitimate voice, a contribution to make, alongside others, to the development and critique of educational policy at strategic levels and to developments in schools and classrooms. Within this broad theme four related topics are addressed: (1) lifelong learning; (2) knowledge of professional development and change; (3) the limits and possibilities of educational research; and (4) dilemmas in being a professional: moral purposes and roles of academics in continuing professional development.
Class Size and Educational Achievement: a review of methodology with particular reference to study design[1]
Authors: Goldstein Harvey , Blatchford Peter
Published: June 2007

The article reviews research into class size effects from a methodological viewpoint, especially concentrating on the various strengths and weaknesses of randomised controlled trials and observational studies. It discusses population definitions, causation and generally sets out the criteria for valid inferences from such studies. For illustration it presents some new findings from a reanalysis of the large data set from the Tennessee STAR (Student Teacher Achievement Ratio) study.
Schools, Pupils and Examination Results: contextualising school ‘performance’
Authors: Gibson Alex , Asthana Sheena
Published: June 2007

This article seeks to demonstrate the extent to which school‐level performance in the General Certificate of Secondary Education (GCSE) is underpinned by variations in the socio‐economic background of pupils. Using a postcode‐census method of profiling the socio‐economic characteristics of school populations, the study analyses the examination performance of 259 schools in 12 local education authorities (LEAs). Describing an Ordinary Least Squares (OLS) multiple regression model which accounts for 64% of between‐school variance in the GCSE performance of non‐selective schools, the paper concludes (1) that uncontextualised performance statistics are fundamentally flawed, and (2) that policies directed at school improvement must acknowledge and address underlying constraints on school performance.
’I’ ll be a nothing’: structure, agency and the construction of identity through assessment[1]
Authors: Reay Diane , Wiliam Dylan
Published: June 2007

Drawing on data from focus group and individual interviews with Year 6 pupils in the term leading up to Key Stage 2 National Curriculum tests, this article explores the extent to which children's perceptions of the tests contribute to their understandings of themselves as learners. The tension between agency and structure becomes apparent in children's differential dispositions to view the testing process as a definitive statement about the sort of learner they are. Although children's responses are varied, what most share is a sense of an event which reveals something intrinsic about them as individuals. The article also explores the emotions, in particular the anxiety and fear, which permeate such understandings of the National Curriculum assessment process.
Knowledge, Learning and the Curriculum of the Future[1]
Authors: Young Michael
Published: June 2007

This article is concerned with the application of sociological analysis to the development of a 16‐19 curriculum of the future. It begins by clarifying the concept of the curriculum with particular reference to the 16‐19 phase of education. It then presents a brief analysis of recent developments in 16‐19 education in England and Wales and highlights the issues that these developments have raised. The final section of the paper draws on a sociological approach to knowledge and learning to suggest how these issues might be addressed by curriculum policy makers. The article concludes by proposing a model of the 16‐19 curriculum of the future based on the idea of ‘connective specialisation’.
Schooling, Networks and the Labour Market: explaining participation in lifelong learning in Northern Ireland[1]
Authors: Field John
Published: June 2007

School attainment is generally believed to be correlated positively with participation in adult learning. The paper explores evidence from Northern Ireland that suggests an inverse relationship is also possible under certain circumstances. In Northern Ireland high school attainment co‐exists with low participation in adult learning. The paper considers evidence suggesting that the existence of strong social networks, shared norms and value, and a high level of trust may be a contributory factor to this divergent pattern. While there is a strong social concensus around the academic schooling of young people in Northern Ireland, this ‘social capital’ both provides an alternative to formal participation in adult learning and a legitimation for low aspirations among adults.
Evaluating Interprofessional Education: two systematic reviews for health and social care
Authors: Barr Hugh , Hammick Marilyn , Koppel Ivan , Reeves Scott
Published: June 2007

Learning between professions has been widely invoked in health and social care in the belief that it improves collaboration in practice. Evidence to substantiate that belief is, however, elusive. Obstacles to the rigorous evaluation of interprofessional education are formidable, but this article reports progress towards establishing an evidence base. It describes two reviews. One is subject to criteria for Cochrane Collaboration, the other less constrained. Findings are reported for the first and methodology is discussed for the second. The article begins with an overview of interprofessional education in health and social care.
Evaluation of a Focused Literacy Teaching Programme in Reception and Year 1 Classes: classroom observations
Authors: Sylva Kathy , Hurry Jane , Mirelman Helen , Burrell Andrew , Riley Jeni
Published: June 2007

Systematic observation was carried out in 12 classrooms (six in an innovative literacy programme which was a precursor to the Literacy Hour and six comparison classes) to explore teaching and learning which occurred after an intensive in‐service programme for reception teachers. Altogether 216 children were observed in an inner‐city authority, each for 15 minutes according to a schedule of time‐sampled and event‐sampled categories. Teaching behaviours were included in the observations as well as pupils' learning activities related to curriculum areas and also to play or ‘domestic classroom’ routines. Results showed that children devoted about equal amounts of time to English in the two types of classrooms and that staff‐pupil ratios were also similar. There were no differences in the amount of whole class, group or individual learning observed. However, teachers in the intervention classrooms (Focused Literacy Teaching) were more likely to use ‘direct teaching’ methods which included managing children's activities and using questions to instruct. Teachers in the comparison classes spent more time in ‘physical caring’. There were also differences in pupil learning activities. Although there were no differences in the amount of time children read to a teacher in the two types of classroom, children in the literacy programme spent more time reading to one other child, to a small group and on their own. Moreover, children in the literacy programme spent more time in shared reading and writing. In contrast, children in the comparison classrooms spent more time drawing, colouring and playing. Thus, a striking finding was the greater amount of peer literacy learning in the innovative classrooms. Teachers spent time setting up and managing the literacy activities of the groups, although often the groups continued under their own steam once the learning activity had been started. This led to a greater focus on reading, not only as a result of the teacher's direct teaching, but also through collaborative group work and children learning on their own.
Civil Reality? Simulation Experiments on the Impact of Civil War in a Realist World
Authors: Stoll Richard J.
Published: June 2007

The most widely used theoretical framework in international relations is realism. Realism takes many forms, and there have been hundreds of writings on the topic. In the United States, the two most popular exemplars of realism are Morgenthau (Morgenthau & Thompson, 1985; original 1948) and Waltz (1979). There is no systematic attempt to incorporate civil wars into the realist framework. In this paper, we use a computer simulation to explore the impact of a state's civil war experience on its interstate war experience. The results suggest that a state's civil war experience can have an impact on its interstate war experience.
Mathematical Modelling of Tumour Invasion and Metastasis
Authors: Anderson A. R. A. , Chaplain M. A. J. , Newman E. L. , Steele R. J. C. , Thompson A. M.
Published: June 2007

In this paper we present two types of mathematical model which describe the invasion of host tissue by tumour cells. In the models, we focus on three key variables implicated in the invasion process, namely, tumour cells, host tissue (extracellular matrix) and matrix‐degradative enzymes associated with the tumour cells. The first model focusses on the macro‐scale structure (cell population level) and considers the tumour as a single mass. The mathematical model consists of a system of partial differential equations describing the production and/or activation of degradative enzymes by the tumour cells, the degradation of the matrix and the migratory response of the tumour cells. Numerical simulations are presented in one and two space dimensions and compared qualitatively with experimental and clinical observations. The second type of model focusses on the micro‐scale (individual cell) level and uses a discrete technique developed in previous models of angiogenesis. This technique enables one to model migration and invasion at the level of individual cells and hence it is possible to examine the implications of metastatic spread. Finally, the results of the models are compared with actual clinical observations and the implications of the model for improved surgical treatment of patients are considered.
The DNA Damage‐Induced Cell Cycle Checkpoints
Authors: Widlak Piotr
Published: June 2007

The proliferation of eukaryotic cells is driven by a process called the cell cycle. Proper regulation of this process, leading to orderly execution of sequential steps within the cycle, ensures normal development and homeostasis of the organism. On the other hand, perturbations of the cell cycle are frequently attributed to cancer cells. Mechanisms that ensure the order and fidelity of events in the cell cycle are called checkpoints. The checkpoints induced by damaged DNA delay the cell cycle progression, providing more time for repair of lesion before DNA replication and segregation. The DNA damage‐induced checkpoints can be recognized as signal transduction pathways that communicate information between DNA lesion and components of the cell cycle. Proteins involved in the cell cycle, as well as components of the signal transduction pathways communicating with the cell cycle, are frequently products of oncogenes and tumor suppressor genes. Malfunction of these genes plays a critical role in the development of human cancers. The key component in the checkpoint machinery is tumor suppressor gene p53, involved in either regulation of the cell cycle progression (e.g. Gl arrest of cells treated with DNA damaging factor) or activation of programmed cell death (apoptosis). It is postulated that p53 protein is activated by DNA damage detectors. One of the candidates for this role is DNA‐dependent protein kinase (DNA‐PK) which recognizes DNA strand breaks and phosphorylates p53 protein.
A Mathematical Model of HIV Transmission in Homosexuals with Genetic Heterogeneity
Authors: Schmtiz Shu-Fang Hsu
Published: June 2007

Several AIDS cohort studies observe that the incubation period between HIV infection and AIDS onset can be shorter than 3 years in about 10% seropositive individuals, or longer than 10 years in about 10‐15% individuals. On the other hand, many individuals remain seronegative even after multiple exposures to HIV. These distinct outcomes have recently been correlated with some mutant genes in HIV co‐receptors (e.g., CCR5,CCR2 and CXCR4). For instance, the mutant alleles △32 and m303 of CCR5 may provide full protection against HIV infection in homozygotes and partial protection in heterozygotes; moreover, infected heterozygotes may progress more slowly than individuals who have no mutant alleles. Frequencies of these mutant alleles are not very low in Caucasian populations, therefore, their effects may not be insignificant. Based on available data, we propose a one‐sex model with susceptibles classified as having no, partial or full natural resistance to HIV infection, and infecteds classified as rapid, normal or slow progressors. Our goals are to investigate the impact of such heterogeneity on the spread of HIV and to identify key parameters. The basic reproductive number R0 is derived from a simplified model. The relative contributions to R0 from the three groups of infecteds are investigated. We present a rough estimating procedure making use of limited data to estimate some new parameters specific to our model. Finally the rough estimating procedure is applied to an example focusing on CCR5‐△32 in San Francisco gay men. The relative contributions to R0 among the three infected groups are compared using two different classifying criteria for infecteds. Under given assumptions, we conclude that, without any intervention, HIV infection will continue to spread in this population and the epidemic is mainly driven by the normal progressors. The transmission rates from infecteds are identified as key parameters.
Repopulation of Tumour Cells during Radiotherapy Is Doubled during Treatment Gaps
Authors: Tarnawski Rafal , Skladowski Krzysztof , Swienrniak Andrzej , Wygoda Andrzej , Mucha Anna
Published: June 2007

The aim of this work is to analyse the proliferation of tumour cells in the treatment gapduring the radiotherapy for head neck cancer.

Material and Methods: The clinical material is based on records of head and neck patients treated by radiotherapyalone in our institution. The effect of radiotherapy was assumed to be described by a linearquadratic model. The patient data were fitted directly to the radiobiological model and theparameters were estimated using maximum‐likelihood procedures.

Results: According to our model results of treatment were significantly correlated with Normalised Total Dose of radiation, the tumour progression (according to TNM), the overall treatment time and the gap duration. The laryngeal cancers had better prognosis then cancers of oroand nasopharynx. When the treatment time is prolonged without treatment interruptions 0.36 Gylday is lost due to the repopulation of tumour cells. During the treatment gap proliferation is faster and 0.67 Gylday is lost.

Conclusion: Proliferation of tumour cells is faster during the treatment gap then during the days with irradiation.
The Prognosis of Survivance in Solid Tumor Patients Based on Optimal Partitions of Immunological Parameters Ranges
Authors: Kunznetsova A. V. , Sen′ko O. V. , Matchak G. N. , Vakhotsky V. V. , Zabotina T. N. , Korotkova O. V.
Published: June 2007

New logical and statistical methods are used for the analysis of relationships between survivance and immunological variables. These methods are based on the search of the regularities (syndromes) in the multidimensional space. The syndromes are the elements of partitions of allowable areas of variables. To estimate the statistical validity of found regularities the new technique based on Monte‐Carlo computer simulation was used.

We present some results from immunological research to illustrate the methods of logistical regularities search. Two tasks are described. The broad panel of monoclonal antibodies for differentiation lymphocytic antigens were used for lymphocytes subpopulations analysis. The purpose of the first task was the evaluation of significance of immunological parameters for prediction of 1‐year metastasis‐free survival in non‐metastatic osteosarcoma of extremities. The second task was the construction of the predicting alghorithm for prognosis 2‐years survival of patients with stomach cancer. The optimal sets of parameters for prediction of survivance was found for both tasks. We found out the high forecasting informativity of HLA‐DR+ cells percentage in the 1st task, and the percentage of adhesion cells (CD50+‐lymphocytes) in the 2nd task. Multivariate forecasting alghorithms are developed.
The Role of Cell Motility in Metastatic Cell Dominance Phenomenon: Analysis by a Mathematical Model
Authors: Kolobov A. V. , Polezhaev A. A. , Solyanik G. I.
Published: June 2007

Metastasis is the outcome of several selective sequential steps where one of the first and necessary steps is the progressive overgrowth or dominance of a small number of metastatic cells in a tumour. In spite of numerous experimental investigations concerning the growth advantage of metastatic cells, the mechanisms resulting in their dominance are still unknown. Metastatic cell overgrowth occurs even if doubling time of the metastatic subpopulation is shorter than that of all others subpopulations in a heterogeneous tumour. In order to examine the hypothesis that under conditions of competition of cell subpopulations for common substrata cell motility of the slow‐growing subpopulation can result in its dominance in a heterogeneous tumour, a mathematical model of heterogeneous tumour growth is suggested. The model describes two cell subpopulations which can grow with different rates and transform into the resting state depending on the concentration of the substrate consumed by both subpopulations. The slow‐growing subpopulation is assumed to be motile. In numerical simulations it is shown that this subpopulation is able to overgrow the other one. The dominance phenomenon (resulting from random cell motion) depends on the motility coefficient in a threshold manner: in a heterogeneous tumour the slow‐dividing motile subpopulation is able to overgrow its non‐motile counterparts if its motility coefficient exceeds a certain threshold value. Computations demonstrate independence of the motile cells overgrowth from the initial tumour composition.
Development and Evaluation of a Stochastic Simulation of Cartilage Bone Osteogenesis
Authors: Church R. P. , Langton C. M.
Published: June 2007

Both long and irregular bones tend to form via endochondral ossification and are referred to as cartilage bones. Based upon the hypothesis that bone grows and forms as a semi‐deterministic/semi‐chaotic system, it should be possible to accurately model the osteogenesis of cartilage bones using a stochastic simulation. A thorough review of the literature has been undertaken enabling the cell types and tissues to be identified and a set of simulation rules to be established. The operation of the simulation has been evaluated longitudinally, reporting bone and blood vessel structures as the simulation develops to completion with fusion of the epiphyses; the simulation variability has been assessed by repeat runs using the same default conditions; and the effect of independently modifying key simulation parameters has been studied. This is thought to be the first report of a stochastic simulation of cartilage bone osteogenesis. The developed structures accurately follow the growth and form of irregular cartilage bones such as the vertebrae or calcaneus. The future of the simulation is now dependent primarily upon its potential utility in the field of bone metabolism and disease.
Shape Parameterization of the Time‐Dependent Geometry of the Heart for Steady Fluid Dynamical Analysis
Authors: Evans C. J. , Bloor M. I. G. , Wilson M. J.
Published: June 2007

A parametric model of the complex time‐dependent geometry of the ventricles of the human heart is constructed. The geometry model is created by means of a boundary value approach, solving an elliptic partial differential equation to generate a representation of the inner surface of the ventricles. The technique provides a closed‐form description of the geometry with the advantage that the geometry can be readily changed without introducing holes or discontinuities in the surface. It also allows a straightforward link to analysis, facilitating the calculation of physical properties such as those relevant to fluid dynamics. As an application of this work, the geometry model is combined with commercial CFD software to analyse the blood flow in the heart. Steady‐state calculations are performed at various time steps to follow the evolution of the fluid flow.
Testing for Periodicity in Signals: An Application to Detect Partial Upper Airway Obstruction during Sleep
Authors: Aittokallio T. , Gyllenberg M. , Nevalainen O. , Polo O.
Published: June 2007

A simple method for detecting periodic components of unknown periodicity in a signal is presented. The method is based on spectral decomposition of signal using orthonormal functions. Traditionally, hypothesis testing together with harmonic functions is used, but we show that the same statistical properties are obtained for other systems of orthonormal functions as well. The appropriate behavior of the method is first demonstrated with simulation studies and then tested to identify visually determined clusters of high‐frequency movements, which may repeat in synchrony with respiration during sleep. The good performance in the practical tests suggests that an automatic identification of these clusters could be based on Walsh functions.
Mathematical and Biological Modelling of RNA Secondary Structure and Its Effects on Gene Expression
Authors: Hughes T. A. , McElwaine J. N.
Published: June 2007

Secondary structures within the 5′ untranslated regions of messenger RNAs can have profound effects on the efficiency of translation of their messages and thereby on gene expression. Consequently they can act as important regulatory motifs in both physiological and pathological settings. Current approaches to predicting the secondary structure of these RNA sequences find the structure with the global‐minimum free energy. However, since RNA folds progressively from the 5′ end when synthesised or released from the translational machinery, this may not be the most probable structure. We discuss secondary structure prediction based on local‐minimisation of free energy with thermodynamic fluctuations as nucleotides are added to the 3′ end and show that these can result in different secondary structures. We also discuss approaches for studying the extent of the translational inhibition specified by structures within the 5′ untranslated region.
An Overview of Models of Cell Proliferation
Authors: Appleton David R.
Published: June 2007

Some different types of models of cell proliferation are discussed. The importance of basing the models on experimental data is emphasised, but warnings are given about some of the pitfalls in fitting models of data. The importance of investigating alternative models which might lead to similar experimental findings is stressed. The use of simulation to assess the ability of an analytical method to extract correct information from experimental data is advocated. In this instance, the modelling process takes place in advance of the data collection. Models described relate to cell proliferation in a transplantable tumor, the prostate of the castrate mouse stimulated with testosterone, and stratified squamous epithelium. Experimental techiques include measurment of tumor size, calculation of labelling and mitotic indices over time, and the fraction labelled mitoses method.
An fMRI Study of the Interaction of Stress and Cocaine Cues on Cocaine Craving in Cocaine‐Dependent Men
Authors: Duncan Erica , Boshoven William , Harenski Keith , Fiallos Ana , Tracy Holly , Jovanovic Tanja , Hu Xiaoping , Drexler Karen , Kilts Clint
Published: June 2007

Acute stress is associated with relapse in cocaine addiction, possibly through the activation of craving‐related neural circuitry. Neural responses to cocaine cues and acute stress were investigated in an fMRI study. Ten male participants mentally reenacted personalized scripts about cocaine use and a neutral experience both with and without a stressor present (anticipation of electrical shock). Interaction analysis between script type and stress condition revealed greater activation of the posterior cingulate cortex and of the parietal lobe during the cocaine script in the presence of the stressor. These data suggest that stress may precipitate relapse in cocaine addiction by activating brain areas that mediate reward processing and the attentional and mnemonic bias for drug use reminders.
Reevaluating the Self‐Medication Hypothesis among the Dually Diagnosed
Authors: Henwood Benjamin , Padgett Deborah K.
Published: June 2007

The self‐medication hypothesis (SMH) is an intuitively appealing explanation for substance use. Conceptually, however, it is not always clear what the hypothesis entails, particularly when applied to persons with mental and substance use disorders. This makes empirical support for SMH difficult to evaluate. By classifying the self‐reported reasons for substance use from 33 participants in a NIMH‐funded qualitative study of dual diagnosis and homelessness, this study aims to evaluate the applicability of SMH. How one conceptualizes SMH will determine whether SMH is empirically supported. When SMH refers to using substances strictly to cope with symptoms of mental disorders, only 11 out of 72 attributions support it. When SMH refers to using substances to cope with painful feelings in general, more than half of all attributions support SMH. The significance of accurately understanding the various reasons people give for why they use substances is discussed.
Problems of Nepalese hydropower projects due to suspended sediments
Authors: Thapa Bhola , Shrestha Raju , Dhakal Projjwal , Thapa Biraj Singh
Published: June 2007

Nepal has high potential for hydropower due to glaciers in the Himalayas, regular monsoon rain and local topography. Himalayan Rivers contain large quantities of sediment with hard abrasive particles, which is a hurdle for the economic exploitation of hydropower resources. Erosion of the earth's surface takes place because of influence of climatic, tectonic and human activities. Almost all the power plants in the Himalayan region are affected by excessive sediment in rivers that reduce the life of plants either by filling reservoirs or by erosion of turbine components. The design and operation of headwork components in hydropower plants can only manipulate sediment particle size and hence only sediment concentration in the water. The erosion of hydraulic machinery depends on eroding particles, that is, their size, shape and hardness; on substrates, their chemistry, elastic properties, surface hardness and surface morphology; and on operating conditions, velocity, impingement angle and concentration. The shape, size and mineral content of sediment vary at different locations of the same river system depending on distance traversed by particles, gradient of the river and the geological formation of the river course and catchment areas.

The Khimti hydropower project in Nepal represents a typical high head power plant in the Himalayan River that is affected by river sediment. Erosion tests of turbine material carried out at Kathmandu University revealed the dependence of erosion rate on mineral content. The erosion tests have shown trends relative to the quartz content present in samples from river basins in different parts of the country. There was some indication that the shape of particles had some effect. Sediments in the hydropower projects are normally considered as a burden, but there is scope for industrial use of these sediments.
Impacts of a small dam on macroinvertebrates: A case study in the Tinau River, Nepal
Authors: Sharma Chhatra Mani , Sharma Subodh , Borgstrom Reidar , Bryceson Ian
Published: June 2007

Macroinvertebrate composition, eco-morphological habitat descriptions and substrate composition were assessed above and below a small dam in the Tinau River, Nepal to explore the impact of the dam on biotic conditions. Four sites, one about 1.5 km above, one just above the dam site, one just below, and one about 2.5 km below the dam, were selected for qualitative and quantitative samplings of macroinvertebrates. The Nepalese Biotic Score method was used for the biological water quality assessment. The most abundant groups of macroinvertebrates among the total collection were of the family Chironomidae (53.5 percent) followed by Ephemeroptera (36 percent) and Trichoptera (5 percent). Only one of the dominant families, Baetidae, showed significant variability with substrate composition. The dam building had significant impacts on the macroinvertebrate composition just above the dam site, probably as a result of deposition of inorganic material within the small reservoir and changes in water speed. Damming of the Tinau River thus seems only to have a relatively minor impact on the river biota downstream of the dam site. The water quality of the river was assigned as Class II in all the stations, indicating its suitability for drinking after treatment.
The Effects of Consistency of Performance on A Level Examiners' Judgements of Standards
Authors: Scharaschkin Alex , Baird Jo‐Anne
Published: June 2007

ABSTRACT One source of evidence used for the setting of minimum marks required to obtain grades in General Certificate of Education (GCE) examinations is the qualitative, expert judgement of examiners. The effect of consistency of candidates' performance across questions within an examination paper upon examiners' judgements of gradeworthiness was investigated, for A level examinations in two subjects. After controlling for mark and individual examiner differences, significant effects of consistency were found. The pattern of results differed in the two subjects. In biology, inconsistent performance produced lower judgements of grade‐worthiness than consistent or average performance. In sociology, very consistent performance was preferred over average consistency. The results of this study showed that a feature of the examination performance that was not part of the marking scheme affected grading decisions. It is concluded that examiners' judgements of standards should be supported by other sources of evidence, such as examination statistics.
Students' Experiences of Ability Grouping—disaffection, polarisation and the construction of failure1
Authors: Boaler Jo , Wiliam Dylan , Brown Margaret
Published: June 2007

This paper reports findings from the first two years of a four‐year longitudinal study into the ways that students' attitudes towards, and achievement in, mathematics are influenced by ability‐grouping practices in six schools. Through the use of questionnaires administered to the whole cohort of 943 students, interviews with 72 students and approximately 120 hours of classroom observation, the relative achievement in, and the changes in attitudes towards, mathematics are traced as the students move from year 8 to year 9, with students in four of the six schools moving from mixed‐ability grouping to homogenous ability groups or ‘sets’. Ability‐grouping was associated with curriculum polarisation. This was enacted through restriction of opportunity to learn for students in lower sets, and students in top sets being required to learn at a pace which was, for many students, incompatible with understanding. The same teachers employed a more restricted range of teaching approaches with ‘homogeneous’ groups than with mixed‐ability groups which impacted upon the students' experiences in profound and largely negative ways. Almost all of the students interviewed from ‘setted groups’ were unhappy with their placement.
Infringement versus conviction: the social impact of a minor cannabis offence in South Australia and Western Australia
Authors: Lenton Simon , Humeniuk Rachel , Heale Penny , Christie Paul
Published: June 2007

Quantitative data is reported from a study of 68 South Australians who had received an infringement notice or ‘cannabis expiation notice’ (CEN) and 68 West Australians who received a criminal conviction for a minor cannabis offence not more than 10 years ago to compare impact of the infringement notice and the conviction on their lives. The majority of both groups saw themselves as largely law‐abiding, had respect for the law in general and had positive views regarding cannabis. However, more of the convicted group, compared to the infringement notice group, reported negative employment consequences (32% vs. 2%), further problems with the law (32% vs. 0%), negative relationship consequences (20% vs. 5%)and accommodation consequences (16%vs. 0%)as a result of their apprehension. While neither conviction nor infringement deterred subsequent cannabis use for the vast majority, the negative social impacts of conviction were far greater than those resulting from an infringement notice. The findings have implications for the legislative options for regulation of cannabis possesssion and use.
Enzyme markers in frogs (Rana spp.) for monitoring risk of aquatic pollution
Authors: Van den Brink N. W. , Lee-de Groot M. B. E. , de Bie P. A. F. , Bosveld A. T. C.
Published: June 2007

Induction of ethoxyresorufin-O-deethylase activity in frog tadpoles (Rana arvalis) by exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin was confirmed experimentally. In a field study on a polluted site, the Volgermeer, the ethoxyresorufin-O-deethylase activities in juvenile green frogs (Rana esculenta) were inhibited, despite an elevated Toxic Equivalency Quotienttcdd, indicative of exposure to dioxin-like contaminants. Aromatase activities in the frogs from the Volgermeer were inhibited, which is in line with exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin in in vitro studies reported elsewhere. It is hypothesized that a non-identified (group of) contaminant(s) inhibits ethoxyresorufin-O-deethylase activity and so interferes with the P450 enzyme system. The combined results suggest that dioxin-like contaminants may affect the reproductive performance of frogs in the Volgermeer. This study shows that the combined deployment of various biomarkers is needed in order to elucidate the possible risks that contaminants pose to amphibians. Enzyme activities in frogs appear suitable indicators, provided that a combined set of enzyme markers is investigated.
Water and Deuterium Oxide Permeability through Aquaporin 1: MD Predictions and Experimental Verification
Authors: Mamonov Artem B. , Coalson Rob D. , Zeidel Mark L. , Mathai John C.
Published: June 2007

Determining the mechanisms of flux through protein channels requires a combination of structural data, permeability measurement, and molecular dynamics (MD) simulations. To further clarify the mechanism of flux through aquaporin 1 (AQP1), osmotic pf (cm3/s/pore) and diffusion pd (cm3/s/pore) permeability coefficients per pore of H2O and D2O in AQP1 were calculated using MD simulations. We then compared the simulation results with experimental measurements of the osmotic AQP1 permeabilities of H2O and D2O. In this manner we evaluated the ability of MD simulations to predict actual flux results. For the MD simulations, the force field parameters of the D2O model were reparameterized from the TIP3P water model to reproduce the experimentally observed difference in the bulk self diffusion constants of H2O vs. D2O. Two MD systems (one for each solvent) were constructed, each containing explicit palmitoyl-oleoyl-phosphatidyl-ethanolamine (POPE) phospholipid molecules, solvent, and AQP1. It was found that the calculated value of pf for D2O is ∼15% smaller than for H2O. Bovine AQP1 was reconstituted into palmitoyl-oleoyl-phosphatidylcholine (POPC) liposomes, and it was found that the measured macroscopic osmotic permeability coefficient Pf (cm/s) of D2O is ∼21% lower than for H2O. The combined computational and experimental results suggest that deuterium oxide permeability through AQP1 is similar to that of water. The slightly lower observed osmotic permeability of D2O compared to H2O in AQP1 is most likely due to the lower self diffusion constant of D2O.
Algebro-geometric Schrödinger operators in many dimensions
Authors: Chalykh Oleg
Published: June 2007

We collect known results about the Schrödinger operatorsL=−Δ+u(x), generalizing to higher dimension those algebro-geometric operatorsL=−d2/dx2+u(x) with rational, trigonometric and elliptic potential which appear in the finite-gap theory.
Multivariable Burchnall–Chaundy theory
Authors: Previato Emma
Published: June 2007

Burchnall & Chaundy (Burchnall & Chaundy 1928
Proc. R. Soc. A
118
, 557–583) classified the (rank 1) commutative subalgebras of the algebra of ordinary differential operators. To date, there is no such result for several variables. This paper presents the problem and the current state of the knowledge, together with an interpretation in differential Galois theory. It is known that the spectral variety of a multivariable commutative ring will not be associated to a KP-type hierarchy of deformations, but examples of related integrable equations were produced and are reviewed. Moreover, such an algebro-geometric interpretation is made to fit into A.N. Parshin's newer theory of commuting rings of partial pseudodifferential operators and KP-type hierarchies which uses higher local fields.
Epistemology and conceptual resources for the development of learning technologies
Authors: Derry J.
Published: June 2007

Abstract  The issues raised by the design and development of technologies to enhance learning has led to a demand for an appropriate language and form of conceptualization. However, we are insufficiently familiar with the way in which different types of mediated tool use occur, to develop the theoretical models needed for the development of this language and form of conceptualization. In its absence a somewhat eclectic variety of concepts and research, such as the concept of affordance, are recruited in accounts of learning with new technologies. In looking briefly at the relevant area in philosophy this paper will consider whether or not the use of concepts such as affordance give adequate weight to social practice, meaning and knowledge in the design of educational technology. A fruitful source for work in this field which has not been sufficiently exploited is philosophy, particularly recent work in epistemology.