bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of gas permeation barrier properties using electrical measurements of calcium degradation
Authors: Choi Jin Hwan , Kim Young Min , Park Young Wook , Huh Jin Woo , Ju Byeong Kwon , Kim In Sun , Hwang Hee Nam
Published: June 2007

In this work, we developed a thin calcium degradation method introducing sensitive electrical resistance monitoring. We have demonstrated structural models of the inorganic/organic thin films to evaluate barrier properties against water and oxygen permeation. The time-dependent transmission curve of a multibarrier coated on both sides of the polyethersulfone substrate had a linear slope which was measured as 5.17×10−3g∕m2day at 20°C and 60% relative humidity. This system can measure an accurate permeation rate with a high sensitivity in the measurable range of 101–10−6g∕m2day. In addition, the test structure devised is applicable to various fabrication techniques for passivation layers with durability and ultralow permeability for flexible organic light emitting diodes.
Quantitative carrier lifetime images optically measured on rough silicon wafers
Authors: Schubert Martin C. , Pingel Sebastian , The Manuel , Warta Wilhelm
Published: June 2007

Results of optical carrier lifetime measurements like carrier density imaging significantly depend on surface conditions of the sample under test. Rough or textured surfaces have a severe impact on the measurement quality since they cause blurring and overestimation of the lifetime measurement. We propose a correction method for both, the adjustment of the absolute value and the restoration of the spatial distribution of the recombination lifetime. The absolute value is corrected by taking the emissivity of the sample into account. The unblurred signal distribution is obtained by mathematical deconvolution via Wiener filtering. For this purpose an appropriate point spread function is experimentally determined.
Properties of B and P doped Ge nanowires
Authors: Peelaers H. , Partoens B. , Peeters F. M.
Published: June 2007

An ab initio study of the formation and segregation energies of B and P doped Ge nanowires oriented along the [110] direction is performed for fully relaxed H-passivated nanowires. The authors found the preferential dopant positions and the associated formation energies. Edge positions are favorable positions for both types of dopants. In the presence of dangling bond defects P dopants will highly favor the edge positions near the dangling bond, thereby trapping the additional carrier. The results are compared with those found for doped Si nanowires.
Describing Children's Linguistic Development at Home and at School
Authors: Wells Gordon
Published: June 2007

A theory of language is outlined which emphasises the interactive nature of linguistic communication, and it is hypothesised that such interaction forms the basis for the child's acquisition of control of the language system. It is further suggested that differences in quality and quantity of interaction, in which meaning is negotiated in the shared construction of social reality, may be largely responsible for the ‘linguistic disadvantage’ which is the putative cause of the educational under‐achievement of many children. The paper describes the way in which these questions are being investigated in a longitudinal study of the language development of a representative sample of children, based on regular observations of the children's spontaneous linguistic interaction at home and at school.
Experimental Research Strategy and Evaluation Research Designs
Authors: Bynner John
Published: June 2007

Summary Some problems with the application of ‘true’ experimental method in evaluation studies are reviewed and new strategies proposed by Campbell and Cronbach are considered. In appraising their contribution it emerges that an optimum design has to meet the twin aims of theory development in the area of the innovation and ‘leverage’ on the problems with which decision makers are concerned. A multifaceted research approach of the kind proposed by Cronbach combining quantitative and qualitative elements without the necessity for randomised control is seen to hold most promise.
Teacher Expectations? Pupil responses to teacher mediated classroom climate
Authors: Monk Martin J.
Published: June 2007

Three teacher types are developed from a consideration of the self‐fufilling hypothesis with respect to both classroom behaviour and academic achievement. Evidence used to support this typology is drawn from both qualitative and quantitative data. Pupils' comments about their lessons and teachers are used to inform an ordering of rank correlations. The analysis stresses that teachers can effect the ways in which their pupils view the differential distribution of classroom achievement amongst their peers through the teachers' classroom management in lessons. Adopting a symbolic interactionist perspective allows a direct link to be made to pupils' classroom achievement as measured by end of year tests.
Indexes of Stability in Repertory Grids: a small‐scale comparison
Authors: Yorke D. M.
Published: June 2007

The tenets of personal construct theory suggest that the procedure for the completion of a repertory grid should allow respondents to indicate whenever an element falls outside the range of convenience of a construct. In such circumstances blank cells appear in a grid matrix, with consequent problems for analysis. A stability index based on the cumulated change on a per cell’ basis is shown to maximise the use of test‐retest data collected when blank cells are present, and to be superior to Bannister's consistency score, Slater's coefficient of convergence and Slater's general degree of correlation.
The Effectiveness of Volunteer Reading Help and the Nature of the Reading Help Provided in Practice
Authors: Loenen Antoinette
Published: June 2007

This paper reports on an evaluation study of a non‐professional, school‐based reading help scheme called Volunteer Reading Help (VRH). The adult community volunteers were involved in working twice a week for about 30 minutes on an individual basis with junior school children. The study is in two parts. Part One is a pre‐post experimental study investigating the effectiveness of VRH in improving children's reading and Self‐concept. The children were allocated randomly to either VRH (N‐43) or control‐group (N=38). The findings show no significant VRH‐effect. Part Two is an investigation of VRH as it is provided in practice. The analysis of tape‐recorded sessions (of 15 different Volunteer Reading Helpers) shows many discrepancies between the recommended VRH approach and the actual approach taken in practice, in particular with respect to reading for meaning and talking with children. It is recommended that more professional help for the volunteers might improve their effectiveness.
Interviewers, Interviewees and the Exercise of Power (Fictional‐critical Writing as a Method for Educational Research)
Authors: Winter Richard
Published: June 2007

This paper reports an investigation into the process of interviewing applicants for places on an inservice course for teachers in an institution of higher education. A number of interviews were tape‐recorded and transcribed, as were some of the discussions between the interviewers concerning the applicants. Attention is drawn to the problems created by the power dimension of the interview process, which is often taken for granted by interviewers. The paper also illustrates a method of organising research data by (a) writing a short story on the themes which emerge from an initial review of the data, and (b) gathering interpretive critiques of the story from various readers, in order to make explicit the significance of the story as an interpretation of the data.
An Empirical Method of Assessing Topic Familiarity in Reading Comprehension Research
Authors: Spyridakis Jan H. , Wenger Michael J.
Published: June 2007

While numerous studies have shown that prior knowledge and topic familiarity affect comprehension and usability of a text, few researchers account for readers' topic familiarity in studies that investigate other reading comprehension variables. This research note briefly reviews the literature on the effect of prior knowledge and text familiarity on document comprehension and usability and discusses current methods for assessing subjects' topic familiarity. An empirically based method for effectively assessing subjects' topic familiarity is presented.
The Role of Cognitive Strategies in the Transition from Counting to Retrieval of Basic Addition Facts
Authors: Christensen Carol A. , Cooper Tom J.
Published: June 2007

This study examined the hypothesis that children who use cognitive strategies in solving simple addition questions develop greater proficiency in addition than children who fail to employ such strategies. Forty non‐strategy users were provided with instructional experiences to facilitate the development of cognitive strategies. At post‐test 20 children demonstrated cognitive strategy use, while 20 did not utilise these strategies. Strategy users demonstrated greater retrieval at post‐test. However, no other indicators of greater proficiency in addition were detected.
The Impact of the Introduction of GCSE English on Pupil Performance
Authors: Gore Leon
Published: June 2007

This paper presents data from the local education authority of Brent on the 16 + examination results in English for the years 1986–87 and 1987–88. It raises questions as to the nature of the impact of GCSE English on pupil performance, generally, and specifically on the performance of ethnic minority pupils and how this interrelates with the achievement of girls as against boys. The paper begins by raising some of the issues to be discussed and goes on to survey, briefly, contributions to the evidence on educational attainment by ethnic minority pupils. The Brent study is then introduced and the data presented. The question is asked as to whether improved performance in English in schools with substantial ethnic minority pupils can be linked to features of the GCSE examination. There follows some discussion of the differences between the initial GCSE English examination and English Language O level, including methods of assessment. A number of hypotheses are put as to the effect these differences might have.
Beware of Wise Men Bearing Gifts: a case study in the misuse of educational research
Authors: Hammersley Martyn , Scarth John
Published: June 2007

This article is concerned with the report of the ‘three wise men’, Curriculum Organisation and Practice in Primary Schools: a discussion document, which was published in early 1992. The background to the report is examined, and its central argument assessed. In the course of this it is shown that the research evidence cited does not offer convincing support for the claims made. It is concluded that the report represents a misuse of educational research, and implies a false relationship between research and the professional practice of teachers.
Gender Differences in Young Children's Artwork
Authors: Kawecki Ireneusz
Published: June 2007

On the basis of theoretical concepts of symbolic interactionism, researchers endeavoured to capture possible differences in the way children perceive and construe the image of their surroundings, resulting from socially conditioned patterns of behaviour but determined by the individual's gender. For this purpose reference was made to children's artwork in order to locate meaningful differences, as much in content as in composition, which would reflect approaches determined by the artist's gender. The results are presented in this paper.
Measuring Comparability of Standards between Subjects: why our statistical techniques do not make the grade
Authors: Newton Paul E.
Published: June 2007

In the past few years the examination boards in Britain have witnessed a renewed interest from external bodies in the notion of comparability of grading standards between different subjects. This interest has stemmed from concern with findings, from statistical techniques for comparison, suggesting that public examinations in different subjects are not comparable. This article focuses on one of these techniques — the Subject‐Pair Analysis — in an attempt to demonstrate that reliance on the statistical comparison of standards between subjects is misplaced. Fundamental assumptions underlying the Subject‐Pair Analysis, and related analyses, are made explicit and then challenged both in principle and from operational data. These techniques cannot be assumed even to approximate a valid representation of ‘the problem’ of between‐subject comparability because they are inappropriate for dealing with the kind of data that our examinations generate.
‘New’ Cultures of Training: emerging male (hetero) sexual identities
Authors: Ghaill Maírtín Mac An
Published: June 2007

Our understanding of a rapidly changing British society is currently being made more difficult as a result of the underplaying of sexual politics. More specifically, contemporary academic and political representations of changing social relations within institutional sites, such as family life, schooling, training and the workplace, are helping to make invisible emerging identities. This article focuses upon ethnographic research on a Modern Apprenticeship in the late 1990s. It sets out to highlight the productiveness of theory‐led empirical work, exploring the local production within a further education site of masculine identities. These identities are, of course, class based and ethnically shaped and these dimensions will be referred to at particular places in the text. However, the emphasis here is upon the complex interplay between labour process, training cultures and institutional restructuring, with questions of changing male subjectivities in relation to emerging (hetero)sexual styles.
By Appointment: governance, markets and managerialism in further education
Authors: Gleeson Denis , Shain Farzana
Published: June 2007

This article examines the changing conditions of governance in the post‐incorporated further education (FE) sector. Six years on from the incorporation of colleges in 1993 (Further and Higher Education Act, 1992), the article considers the various ways in which FE governance finds expression in market and managerial reform in this expanding £4bn sector recovering from industrial conflict, low morale, mismanagement and, in some cases, sleaze. In this article the authors analyse the wider policy impact of corporate managerialism on forms of governance at college level, which mirror what, elsewhere, has been described as a crisis of standards in public life. Drawing on data from an Economic and Social Research Council [ESRC] funded project 1997‐99 [R000236713] undertaken at Keele, the article analyses the meaning of governance as it is interpreted by chairs of governors interviewed in the study. This article connects with wider findings from the Keele Study regarding the work of lecturers, senior and middle managers in FE. In particular, it focuses on the ways in which chairs mediate reform at college level and, in terms of their business acumen and ‘special relationship’ with chief executives, influence the institutional rather than pedagogic culture of FE. Given the lack of critical FE research in this area, the nature of this article is necessarily tentative, including its conclusions for a more public reconfiguration of FE.
Modeling HIV Epidemic under Contact Tracing — The Cuban Case
Authors: De Arazoza H. , Lounes R. , Hoang T. , Interian Y.
Published: June 2007

A nonlinear model is developed for an epidemic with contact tracing, and its dynamic is studied. A linear version of the model is presented in both deterministic and stochastic versions. We present the data for the cuban HIV/AIDS epidemic and fit the linear model to the data, we obtain estimates for the size of the Cuban HIV epidemic.
On the Discrete Kinetic Theory for Active Particles. Modelling the Immune Competition
Authors: Brazzoli I. , Chauviere A.
Published: June 2007

This paper deals with the application of the mathematical kinetic theory for active particles, with discrete activity states, to the modelling of the immune competition between immune and cancer cells. The first part of the paper deals with the assessment of the mathematical framework suitable for the derivation of the models. Two specific models are derived in the second part, while some simulations visualize the applicability of the model to the description of biological events characterizing the immune competition. A final critical outlines some research perspectives.
Dynamics of Growth and Signaling along Linear and Surface Structures in Very Early Tumors
Authors: Marciniak-Czochra Anna , Kimmel Marek
Published: June 2007

There exists evidence that in early stages tumors progress along linear, tubular, or irregular surface structures. This seems to be the case for atypical adenomatous hyperplasia (AAH), a precursor of adenocarcinoma of the lung. We previously published a simplified model, which showed that early structures had a potential towards spontaneous invasive growth following a latency phase. The transition was facilitated by diffusion of a growth factor and nonlinear cell cycle regulation in cancer cells. The mechanism is analogous to that in Turing pattern formation, although the patterns are irregular and unstable. We introduce more biologically justifiable signaling, in which only the free growth factor molecules diffuse. Flexible nonlinearities in the model accommodate several growth patterns of cells as well as internal versus external production of the growth factor. We show that the reaction‐diffusion setup results in complicated spike‐like solutions. We discuss these results in the light of published data on the AAH.
Bayesian Image Analysis
Authors: Mardia K. V.
Published: June 2007

Bayes′ theorem is a vehicle for incorporating prior knowledge in updating the degree of belief in light of data. For example, the state of tomorrow′s weather can be predicted using belief or likelihood of tomorrow′s weather given today′s weather data. We give a brief review of the recent advances in the area with emphasis on high‐level Bayesian image analysis. It has been gradually recognised that knowledge‐based algorithms based on Bayesian analysis are more widely applicable and reliable than ad hoc algorithms. Advantages include the use of explicit and realistic statistic models making it easier to understand the working behind such algorithms and allowing confidence statements to be made about conclusions. These systems are not necessarily as time consuming as might be expected. However, more care is required in using the knowledge effectively for a given specific problem; this is very much an art rather than a science.
Mathematical Modelling for Keyhole Surgery Simulations: Spleen Capsule as an Elastic Membrabe
Authors: Davies Penny J. , Carter Fiona J. , Roxburgh David G. , Cuschieri Alfred
Published: June 2007

We show that the mechanical properties of the outer covering (or capsule) of pig spleen can be modelled as a nonlinear elastic membrane with an exponential stress‐strain Law. Knowledge of the caspule′s elastic properties is important for the development of a virtual reality training package for keyhole surgery. Bccause capsule tissue is very fragile and tears when clamped and pulled it is not possible to obtain experimental data for which the usual uniform stretch data‐fitting approach can be adoptcd.Instcad we perform experiments in which the capsule deforms non‐uniformly and describe how numerical solutions of the corresponding boundary value problem can be fitted to the experimerimental data in order to validate the biomechanical model.
Biotic communities of Kishanganga river: A pre-impoundment case study of a Himalayan river
Authors: Bhatt J. P. , Bhaskar A. , Pandit M. K.
Published: June 2007

A pre-impoundment study of biotic communities was conducted in the Kishanganga river in Jammu and Kashmir on which a hydro-electric project is proposed. The present study was carried out in two phases, monsoon and post-monsoon, at three sites for the physical, chemical and biological characteristics of the river. There were no significant differences between two phases in the physical and chemical characteristics of the river water except water current velocity and turbidity. Among the biological components, significant differences were observed in the density of phytoplankton and macro-invertebrates between the two phases. Higher densities of these communities were observed during second phase with the exception of one site. Phytobenthos showed only a slight difference in the density between two phases. Didymosphenia geminata (Lyngbye) M. Schmidt. was the most common and abundant species in the phytoplankton as well as phytobenthic communities during both the phases, whereas Leptoceridae and Baetidae were the most commonly represented taxa among macro-invertebrates. Our studies suggest that the river is unpolluted and supports a rich and diverse community composed of species that are mainly pollution intolerant. This study provides baseline data for the aquatic biodiversity of an unregulated Himalayan river and for preparation of an environment management plan for conserving the biotic communities of the river.
The Upper Mustang (Nepal) ecosystem: Population, water quality and tourism
Authors: Boselli A. M. , Caravello G. U. , Baroni A.
Published: June 2007

Upper Mustang, a Nepalese valley of high environmental, social and historical interest, and part of the Mustang District, is located in the Trans Himalayan Region, bordering Tibet to the North, East and West, and from the South along the Kali-Gandaky Valley. The Upper Mustang area was opened to controlled tourism in 1992, such that no more than one thousand trekkers are allowed to visit this area annually.

In order to give a clear view of the environmental quality in Upper Mustang, an evaluation has been made of socio-economic factors, water quality conditions, and tourism characteristics using a combination of biophysical parameters, demographic and human considerations, and the Tourist Positioning Index. With respect to ecosystem health, river water quality, spring water quality, state of human ecology and carrying capacity were considered.

The observations from this study show that village water resources are vulnerable due to fecal pollution. Water used for drinking is exposed to human and animal fecal pollution because the area is almost totally devoid of sewage systems for the effective disposal of wastewater and human wastes. It is necessary to carry out drainage system in the villages and to protect the taps from animal and human fecal wastes with ‘respect areas.’
Tutors’ stories of personal development training – attempting to maximize the learning potential
Authors: Spencer Lesley
Published: June 2007

This paper uses a narrative approach to examine some of the dilemmas that counselling trainers face when designing and running personal development activities as part of a Diploma in Counselling training programme. The research emerges from a focus group discussion by the tutors involved in piloting and evaluating an experimental personal development training programme. The themes examined include: the strengths and weaknesses of unstructured group work; whether structured activities helped quieter members to participate and learn more; how trainers can evaluate and assess students learning in relation to personal development in order to maximize student learning potential. The aim is to invite debate and further re‐tellings from other counselling trainers and practitioners in the field.
Eigenproblem for Jacobi matrices: hypergeometric series solution
Authors: Kuznetsov V.B , Sklyanin E.K
Published: June 2007

We study the perturbative power series expansions of the eigenvalues and eigenvectors of a general tridiagonal (Jacobi) matrix of dimension
d
. The (small) expansion parameters are the entries of the two diagonals of length
d
−1 sandwiching the principal diagonal that gives the unperturbed spectrum.

The solution is found explicitly in terms of multivariable (Horn-type) hypergeometric series in 3
d
−5 variables in the generic case. To derive the result, we first rewrite the spectral problem for the Jacobi matrix as an equivalent system of algebraic equations, which are then solved by the application of the multivariable Lagrange inversion formula. The corresponding Jacobi determinant is calculated explicitly. Explicit formulae are also found for any monomial composed of eigenvector's components.
Lötschberg–geology for tunnellers
Authors: Waltham Tony
Published: June 2007

Switzerland's Lötschberg tunnels present a long story of both failure and success. Tunnelling that began 100 years ago ended in a massive disaster–which is a classic of engineering geology–but subsequent works were very much more successful.
Rapakivi granites
Authors: Müller Axel
Published: June 2007

Rapakivi granites, especially the famous rapakivis from southern Finland, are some of the most attractive building and decorative stones, used world‐wide because of their striking textures and beautiful colours. But rapakivi granites are more than just building material, they have also been studied scientifically for over 100 years to try to explain the formation of their plagioclase‐mantled alkali feldspar ovoids, the rapakivi feldspars which are responsible for the unique texture of the rock. Despite all the work which has been done on them, the formation of this distinctive texture is still not fully understood. Rapakivi granite complexes are not just a ‘pretty face’, they are also associated with important tin deposits in Rondônia and Amazonas in Brazil.
Impact of electromyographic findings on choice of treatment and outcome1
Authors: Rigler I. , Podnar S.
Published: June 2007

The subsequent clinical course of patients examined in the EMG laboratory has not been adequately studied before. It is not known how EMG findings in practice affect patients’ final diagnosis, treatment and outcome. The aim of the present study was to test the hypothesis that EMG results have an important impact on the choice of patients’ treatment and on outcome. Three years after EMG examination, a short questionnaire asking about initial symptoms, the final diagnosis, treatment and current symptoms was sent to 300 consecutive EMG patients. Responses concerning 186 of them (39% men) were received either from patients and/or from their referring physicians. Information obtained during EMG examination was also added. Data was analyzed using methods of bivariate and multivariate statistics. We found that patients with a pathologic EMG had a better clinical outcome 3 years later. Pathologic EMG has an independent effect, pointing to more favorable disease courses, which was further improved by more active treatment approaches received by these patients. The study demonstrated the important impact of EMG findings on the treatment choice and clinical outcome in population consisting mainly of patients with carpal tunnel syndrome and radiculopathy. Studies in other patient populations are needed.
Development and Implementation of an Experimental-Based Reduced-Order Model for Feedback Control of Subsonic Cavity Flows
Authors: Caraballo E. , Little J. , Debiasi M. , Samimy M.
Published: June 2007

This work is focused on the development of a reduced-order model based on experimental data for the design of feedback control for subsonic cavity flows. The model is derived by applying the proper orthogonal decomposition (POD) in conjunction with the Galerkin projection of the Navier-Stokes equations onto the resulting spatial eigenfunctions. The experimental data consist of sets of 1000 simultaneous particle image velocimetry (PIV) images and surface pressure measurements taken in the Gas Dynamics and Turbulent Laboratory (GDTL) subsonic cavity flow facility at the Ohio State University. Models are derived for various individual flow conditions as well as for their combinations. The POD modes of the combined cases show some of the characteristics of the sets used. Flow reconstructions with 30 modes show good agreement with experimental PIV data. For control design, four modes capture the main features of the flow. The reduced-order model consists of a system of nonlinear ordinary differential equations for the modal amplitudes where the control input appears explicitly. Linear and quadratic stochastic estimation methods are used for real-time estimation of the modal amplitudes from real-time surface pressure measurements.
E = mc2: A VIDEO AND MULTIMEDIA TO VISUALIZE RELATIVITY
Authors: FATIBENE LORENZO , FRANCAVIGLIA MAURO , LORENZI MARCELLA GIULIA
Published: June 2007

In the framework of Digital Art applied to Scientific Visualization we have realized a short video together with an interactive multimedia aimed at visualizing and diffusing the main concepts of Special Relativity. This note makes a short presentation of it.
Irregular Satellites of the Planets: Products of Capture in the Early Solar System
Authors: Jewitt David , Haghighipour Nader
Published: June 2007

All four giant planets in the Solar system possess irregular satellites, characterized by large, highly eccentric and/or inclined orbits that are distinct from the nearly circular, uninclined orbits of the regular satellites. This difference can be traced directly to different modes of formation. Whereas the regular satellites grew by accretion within circumplanetary disks the irregular satellites were captured from initially heliocentric orbits at an early epoch. Recently, powerful survey observations have greatly increased the number of known irregular satellites, permitting a fresh look at the group properties of these objects and motivating a re-examination of the mechanisms of capture. None of the suggested mechanisms, including gas-drag, pull-down, and three-body capture, convincingly fit the group characteristics of the irregular satellites. The sources of the satellites also remain unidentified.
Threads and Serendipity in the Life and Research of an Entomologist
Authors: Scudder Geoffrey G.E.
Published: June 2007

This article presents an account of the development of Geoffrey Scudder's interest in entomology, with an emphasis on threads and serendipity. Early interests in Hemiptera, insect dispersal, evolution, and chemical ecology were followed by research on insect genitalia and seed bug systematics while at Oxford University. A faculty appointment in Canada led to research on water boatmen, water striders, cardenolides, faunistics, biodiversity, and habitat restoration. Since retirement, activities have diversified to include biodiversity mapping, conservation planning, and enhancing raised-bog integrity.
Atom Probe Tomography of Electronic Materials
Authors: Kelly Thomas F. , Larson David J. , Thompson Keith , Alvis Roger L. , Bunton Joseph H. , Olson Jesse D. , Gorman Brian P.
Published: June 2007

The state of application of atom probe tomography to electronic materials is assessed. The benefits and challenges of the technique are discussed with regard to its impact on this field of materials science. Specimen preparation in particular is emphasized as the key to success with modern atom probes. Electronic materials referenced in this paper include components of complementary metal/oxide/semiconductor (CMOS) structures, compound semiconductors, and thin films for data storage and general applications. Many examples from recent work are provided as illustrations of the types of information that can be derived and the impact this information can have on the research, development, processing, and failure analysis of electronic materials.
Single-Molecule Micromanipulation Techniques
Authors: Neuman K.C. , Lionnet T. , Allemand J.-F.
Published: June 2007

Single-molecule micromanipulation techniques traditionally have been developed for biophysical applications, but they are being increasingly employed in materials science applications such as rheology and polymer dynamics. Continuing developments and improvements in single-molecule manipulation techniques afford new opportunities in a broad range of fields. In this review we present an overview of current single-molecule manipulation techniques, with an emphasis on optical and magnetic tweezers, followed by a description of the elastic properties of single biopolymers. We then review the use of micromanipulation techniques to locally probe material properties. To provide some insight into biophysical questions addressed by these techniques, we describe two applications, which further serve to illustrate the power and versatility of single-molecule micromanipulation techniques. We conclude with a brief discussion of emerging applications and techniques.
The Clockwork of Metabolism
Authors: Moynihan Ramsey Kathryn , Marcheva Biliana , Kohsaka Akira , Bass Joseph
Published: June 2007

The observation that cycles of sleep and wakefulness occur with a periodicity fixed in time to match the rotation of the Earth on its axis provided a key to unlock the first genetic code for a neurobehavioral pathway in flies and ultimately in mice. As a remarkable outcome of this discovery, we have gained an unprecedented view of the conserved genetic program that encodes a sense of time across all kingdoms of life. The tools are now in hand to begin to understand how important processes such as energy homeostasis and fuel utilization are coordinated to anticipate daily changes in environment caused by the rising and setting of the sun. A better understanding of the impact of circadian gene networks on nutrient balance at the molecular, cellular, and system levels promises to shed light on the emerging association between disorders of diabetes, obesity, sleep, and circadian timing.
Economic burden of expected epidemiological changes in diseases related to tobacco, Mexico
Authors: Arredondo Armando , Carrillo Carlos , Zuñiga Alexis
Published: June 2007

OBJECTIVE: To determine health care costs and economic burden of epidemiological changes in diseases related to tobacco consumption. METHODS: A time-series analysis in Mexico (1994-2005) was carried out on seven health interventions: chronic obstructive pulmonary diseases, lung cancer with and without surgical intervention, asthma in smokers and non-smokers, full treatment course with nicotine gum, and full treatment course with nicotine patch. According with Box-Jenkins methodology, probabilistic models were developed to forecast the expected changes in the epidemiologic profile and the expected changes in health care services required for selected interventions. Health care costs were estimated following the instrumentation methods and validated with consensus technique. RESULTS: A comparison of the economic impact in 2006 vs. 2008 showed 20-90% increase in expected cases depending on the disease (p<0.05), and 25-93% increase in financial requirements (p<0.01). The study data suggest that changes in the demand for health services for patients with respiratory diseases related to tobacco consumption will continue showing an increasing trend. CONCLUSIONS: In economic terms, the growing number of cases expected during the study period indicates a process of internal competition and adds an element of intrinsic competition in the management of preventive and curative interventions. The study results support the assumption that if preventive programs remain unchanged, the increasing demands for curative health care may cause great financial and management challenges to the health care system of middle-income countries like Mexico.
Sensitivity analysis for unmeasured confounders using an electronic spreadsheet
Authors: Cabral Maria Deolinda Borges , Luiz Ronir Raggio
Published: June 2007

In studies assessing the effects of a given exposure variable and a specific outcome of interest, confusion may arise from the mistaken impression that the exposure variable is producing the outcome of interest, when in fact the observed effect is due to an existing confounder. However, quantitative techniques are rarely used to determine the potential influence of unmeasured confounders. Sensitivity analysis is a statistical technique that allows to quantitatively measuring the impact of an unmeasured confounding variable on the association of interest that is being assessed. The purpose of this study was to make it feasible to apply two sensitivity analysis methods available in the literature, developed by Rosenbaum and Greenland, using an electronic spreadsheet. Thus, it can be easier for researchers to include this quantitative tool in the set of procedures that have been commonly used in the stage of result validation.
Vulnerabilidade de gênero para a paternidade em homens adolescentes
Authors: Almeida Anecy de Fátima Faustino , Hardy Ellen
Published: June 2007

OBJETIVO: Analisar as relações de gênero vivenciadas por adolescentes do sexo masculino e como elas contribuem para torná-los vulneráveis à gravidez na adolescência. MÉTODOS: Estudo qualitativo realizado em Campo Grande, Mato Grosso do Sul, em 2003. Participaram 13 adolescentes masculinos com menos de 20 anos, com um único filho de até 11 meses, cuja mãe estava na mesma faixa etária do pai. Realizaram-se entrevistas semi-estruturadas gravadas. Após transcrição, procedeu-se à análise temática de conteúdo. RESULTADOS: Identificaram-se estereótipos de gênero em que se destacavam papéis de líder, provedor e ativo sexualmente, bem como a rejeição a ser cuidador. Esses papéis apareceram consolidados principalmente na perspectiva dos entrevistados acerca do trabalho como marcador de sua condição de homem e provedor da família. A liderança dos adolescentes prevaleceu no relacionamento com a mãe de seu filho, notadamente na iniciativa das relações sexuais e no uso de contraceptivos. A gravidez foi considerada por eles como "por acaso" e inesperada, mas a paternidade foi vivenciada como uma prova final de sua condição de homens adultos. CONCLUSÕES: Verificou-se a condição de vulnerabilidade dos adolescentes para a paternidade em virtude da socialização de gênero nos moldes tradicionais. Isso foi evidenciado com a ausência dos papéis relativos ao cuidado consigo próprio e com os outros, com a incorporação precoce de papéis de dominação sexual masculina e de trabalhador e pai, ou seja, deixar de ser criança e alcançar a condição de homem.
Aplicação de medidas de ajuste de risco para a mortalidade após fratura proximal de fêmur
Authors: Souza Rômulo Cristovão de , Pinheiro Rejane Sobrino , Coeli Cláudia Medina , Camargo Jr. Kenneth Rochel de , Torres Tânia Z Guillén de
Published: June 2007

OBJETIVO: Analisar os fatores associados à mortalidade em pacientes para tratamento da fratura proximal do fêmur e as diferentes formas de ajuste de risco. MÉTODOS: Estudo de coorte não-concorrente com 390 pacientes com 50 anos ou mais. Os pacientes foram identificados no Sistema de Informações Hospitalares do Sistema Único de Saúde, internados para correção cirúrgica da fratura proximal do fêmur em um hospital universitário do município do Rio de Janeiro, entre 1995 e 2000. Foram levantados dados complementares nos prontuários desses pacientes e elaborados modelos de regressão logística para a chance de óbito em 90 dias após a data da admissão, segundo perfil dos pacientes e do tratamento. Foram calculados índices de classificação da gravidade do paciente. RESULTADOS: A taxa de mortalidade foi de 7,4% e os fatores que tiveram efeito sobre o óbito foram: idade (OR=1,06; IC 95%: 1,02;1,11), quantidade de comorbidades (OR=1,44; IC 95%: 1,12;1,69), índice de comorbidade de Charlson acima de 2 (OR=6,67; IC 95%: 2,98;22,16) e intervalo de tempo para a realização da cirurgia (OR=1,04; IC 95%:1,02;1,07). CONCLUSÕES: A quantidade de comorbidades e o índice de comorbidade de Charlson auxiliaram na predição da mortalidade.
Prevalência e fatores associados para sobrepeso e obesidade em escolares de uma cidade no Sul do Brasil
Authors: Suñé Fabio Rodrigo , Dias-da-Costa Juvenal Soares , Olinto Maria Teresa Anselmo , Pattussi Marcos Pascoal
Published: June 2007

Foi realizado um estudo transversal com o objetivo de determinar a prevalência de sobrepeso e obesidade e os fatores associados ao excesso de peso corporal, em um grupo de escolares de 11 a 13 anos, residentes em Capão da Canoa, Rio Grande do Sul, Brasil. A técnica de amostragem utilizada foi estratificada, proporcional ao número de alunos de cada escola. O estado nutricional foi avaliado mediante os pontos de corte do índice de massa corporal (IMC) de acordo com a idade e o sexo, propostos por Cole et al. no ano 2000. Foram analisadas variáveis sócio-econômicas, demográficas, genéticas e comportamentais. Foram entrevistados 719 escolares em 11 escolas, destes, 541 (75,2%) apresentaram IMC considerado normal, 153 (21,3%) escolares apresentaram sobrepeso e 25 (3,5%) obesidade. Encontrou-se associação estatisticamente significativa com tipo de escola, estado nutricional dos pais, nível de atividade física e tempo de conduta sedentária. A prevalência de sobrepeso e obesidade encontrada nos escolares avaliados mostrou-se elevada (24,8%), e, de acordo com a encontrada na literatura, confirmando a magnitude e gravidade que o problema assumiu entre os escolares de todo o Brasil.
The burden of hospitalization due to overweight and obesity in Brazil
Authors: Sichieri Rosely , Nascimento Sileia do , Coutinho Walmir
Published: June 2007

This article estimates the burden of hospitalization associated with overweight and obesity in Brazil. The analysis of all hospitalizations for men and women from 20 to 60 years of age was based on the National Healthcare Expenditure Database (SIH-SUS), covering more than 70% of all hospital admissions. Data were for the year 2001. Attributable fraction of hospitalizations associated with diseases related to obesity and overweight was based on the combined risks of United States and European cohorts. The population-attributable fraction for each disease studied was multiplied by values reimbursed to the hospitals and summed to obtain total direct costs. Overall costs of overweight and obesity represent 3.02% of total hospitalization costs for men and 5.83% for women, corresponding to 6.8 and 9.3% of all hospitalization (excluding pregnancy). Diseases associated with overweight and obesity had a significant impact on hospitalizations and economic costs in Brazil, and overall percentages were similar to those from developed countries. Since the nutritional transition is still under way in Brazil, overweight had a higher impact than obesity on disease prevalence and costs.
Proposta e análise crítica de um protocolo de inspeção e de condições sanitárias em supermercados do município de Ibiúna- SP
Authors: Soto Francisco Rafael Martins , Risseto Marcia Regina , Cazzola Célia Priscilla de Barros , Alves Luiz Cláudio Rodrigues , Balian Simone de Carvalho , Maldonado Alessandra Grangel , Pinheiro Sônia Regina , Telles Evelise Oliveira
Published: June 2007

Este trabalho teve por objetivo propor e aplicar um procedimento para a sistematização das inspeções higiênico-sanitárias de supermercados no Município de Ibiúna/SP, e analisar criticamente os resultados com vistas a atingir os objetivos da vigilância sanitária. O trabalho foi desenvolvido durante cinco meses em quatro supermercados, sendo que na primeira inspeção realizou-se o diagnóstico da situação, com a identificação das irregularidades sanitárias. Após esta fase, a equipe da vigilância sanitária realizou os retornos programados aos supermercados, a fim de verificar a evolução das adequações sanitárias e as dificuldades encontradas. Os resultados mostraram que, após quatro inspeções em cada supermercado, foi satisfeita a maioria das adequações sanitárias solicitadas pela equipe da vigilância sanitária e as principais dificuldades por parte do empresário ou gerente do supermercado estiveram centradas na assimilação das informações, no tempo e no custo para sua execução.
Interferência do perfil epidemiológico do idoso na atenção odontológica
Authors: Silva Andréia Lobato da , Saintrain Maria Vieira de Lima
Published: June 2007

Com o considerável aumento da população idosa, cresce a necessidade de profissionais capacitados a lidar com esta faixa etária, em especial de profissionais de saúde. O objetivo principal deste trabalho é comparar o perfil epidemiológico dos adultos e idosos atendidos no curso de Odontologia da Universidade de Fortaleza - UNIFOR. A partir de um corte transversal, foram elaborados indicadores com as informações contidas na ficha semiológica dos prontuários da Instituição, referentes ao período de 2000 a 2002. Pretende-se, desta forma, verificar o relacionamento da idade com as alterações sistêmicas e suas influências no tratamento odontológico. Examinaram-se 702 prontuários, dos quais 520 pertenciam ao grupo de pacientes entre 45 e 59 anos e 182 com os de idade superior a 60 anos. A média de idade dos pacientes foi de 55 anos para o primeiro grupo e de 66 para o segundo. Em ambos os grupos predominou o sexo feminino e prevaleceu o segundo grau incompleto como nível de escolaridade. Os resultados apontaram as doenças cardiovasculares, musculoesqueléticas, endocrinológicas e geniturinárias como as mais recorrentes. A freqüência e o acúmulo de doenças auto-referidas foi superior nos pacientes de mais de 60 anos, apresentando significância estatística quando comparados aos de 45 a 59 anos. Com o aumento da idade, desenvolvem-se inúmeras alterações fisiológicas e/ou patológicas, influenciando no tratamento odontológico, observando-se que, quanto maior a idade, maior o acúmulo de doenças e afecções múltiplas em um mesmo indivíduo, o que implica o uso de variados medicamentos. Foi constatada, no decorrer do estudo, a necessidade de uma relação direta entre o tratamento odontogeriátrico e as manifestações sistêmicas, requerendo, assim, maior atenção aos idosos durante o atendimento odontológico.
Condições de nutrição em crianças Kamaiurá: povo indígena do Alto Xingu, Brasil Central
Authors: Mondini Lenise , Canó Eduardo N. , Fagundes Ulysses , Lima Evandro E. Souza , Rodrigues Douglas , Baruzzi Roberto G.
Published: June 2007

Este estudo teve por objetivo avaliar o estado nutricional, incluindo a prevalência de anemia, de crianças Kamaiurá, povo indígena do Alto Xingu, Brasil Central. Foram estudadas 112 crianças menores de dez anos de idade em 2000/2001. O perfil do crescimento infantil foi descrito segundo a distribuição dos índices altura/idade e peso/altura expressos em escore-z da população de referência do National Center of Health Statistics - NCHS. Os diagnósticos de déficit de altura e da relação peso/altura e o diagnóstico de obesidade corresponderam, respectivamente, aos valores abaixo de -2 escores-z de altura/idade e peso/altura e aos valores acima de 2 escores-z de peso/altura. O diagnóstico de anemia foi determinado a partir de concentrações de hemoglobina sérica inferiores a 11 g/dl para crianças entre seis meses e cinco anos de idade e inferiores a 11,5 g/dl para as crianças com idade entre cinco e dez anos incompletos, conforme recomendação da OMS. Aproximadamente um terço das crianças apresentou déficit de crescimento, enquanto déficit de peso/altura e obesidade não foram diagnosticados entre elas. A anemia esteve presente em mais da metade das crianças índias estudadas, 15% delas apresentando anemia grave. Há necessidade de implementação de ações que visem a melhoria das condições socioambientais, de saúde e nutrição desse povo indígena.