bluuebunny/crossref_metadata_2025_split huggingface dataset:
Safety attitudes and beliefs of junior Australian football players
Authors: Finch C , Donohue S , Garnham A 
Published: October 2002

Objectives:To describe the safety attitudes and beliefs of junior (aged 16–18 years) Australian football players.Setting:Six Victorian Football League Under 18 (VFL U18) clubs in Victoria, Australia.Methods:Cross sectional survey. Altogether 103 players completed a self report questionnaire about their safety beliefs and perceptions of support when injured, across three contexts in which they played: VFL U18 club, local club, and school.Results:Although only 6% believed it was safe to play with injuries, 58% were willing to risk doing so. This increased to almost 80% when players perceived that their chances of being selected to play for a senior elite team would be adversely affected if they did not play. There were significant differences in the perceived level of support for injured players and in the ranking of safety as a high priority across the three settings. In general, the VFL U18 clubs were perceived as providing good support for injured players and giving a high priority to safety issues, but local clubs and particularly schools were perceived to address these issues less well.Conclusions:Junior Australian football players have certain beliefs and perceptions in relation to injury risk that have the potential to increase injuries. These negative beliefs need to be addressed in any comprehensive injury prevention strategy aimed at these players.
A blind review and an informed review of interval breast cancer cases in the Limburg screening programme, the Netherlands
Authors: de Rijke J.M. , Schouten L.J. , Schreutelkamp J.L. , Jochem I. , Verbeek A.L.M. 
Published: October 2002

Objective To investigate the proportion of interval breast cancers that could have been detected at the previous screening examination, and to gain more insight into the characteristics of these tumours. Setting Breast cancer screening programme in mid- and southern Limburg, the Netherlands. Method Firstly, previous screening mammograms of 92 interval cancer cases were blindly reread by the radiologists from two different units as part of their daily screening workload. Secondly, a separate informed review was conducted, in which all of the cases (except for two) were subclassified into four categories: screening error; minimal signs; radiologically occult both at previous screening and at diagnosis; or radiologically occult at previous screening. Trends in recall rates and false and true positive rates were calculated to study potential changes during and after the blind review. Results In the blind review, 15% of the interval cancers were detected in both rereadings and 21% in one rereading. In the informed review, 25% were classified as a screening error and 24% as minimal signs present; 74% of the cases classified as a screening error had been recalled at least once in the blind review. Recall rates and false positive rates in daily screening practice increased significantly during and after the study period. Conclusions About one third of the interval cancers could have been detected in the previous screening round. In order to diminish the number of avoidable interval cancers, review and classification of interval cancers is an important tool for continuing the education of screening radiologists. Therefore, further development of review training procedures is necessary.
Cost of quality management and information provision for screening: colorectal cancer screening
Authors: Robert G. , Brown J. , Garvican L. 
Published: October 2002

Objective To estimate the costs of a quality management (QM) system as proposed by the Quality Management for Screening report for a future national colorectal cancer screening programme. Methods Estimates of the costs of the QM system, including the associated costs of education and training and information provision, were based on expert opinion, the existing literature, and the experience of the current National Health Service (NHS) breast cancer screening programme (BSP) and the NHS cervical cancer screening programme (CSP). Results The cost of a QM system to support a national colorectal cancer programme in the UK was estimated as approximately £3.8 million a year. Further annual costs related to QM will include £500 000 for education and training and £200 000 for information provision. Adding these additional costs to a previously published UK economic evaluation of colorectal cancer screening increases the cost-utility ratio to approximately £6500 per quality adjusted life year gained (over an eight year follow up period). Conclusions Any new screening programme, or an existing one, must have QM to ensure that the quality of screening is high and to maintain the right balance between benefit and harm. The significant costs of such a QM system should be included in any economic evaluation of a screening programme.
Acceptability of flexible sigmoidoscopy screening in older adults in the United Kingdom
Authors: Taylor T. , Williamson S. , Wardle J. , Borrill J. , Sutton S. , Atkin W. 
Published: October 2002

Objectives To assess the acceptability of bowel cancer screening using flexible sigmoidoscopy (FS). Setting Adults aged 55 to 64 recruited from general practices in Welwyn Garden City and Leicester, which were the pilot and start up centres of a multicentred randomised controlled trial of FS screening (the ICRF/MRC Flexible Sigmoidoscopy Screening Trial). Methods Screenees (n=4422) were sent a three month follow up questionnaire that included measures of satisfaction with information given before the test, facilities at the test unit, attitudes of the staff, and explanation of the results. Measures of pain, embarrassment, feelings of being “in control” during the test, willingness to encourage others to have the test, and gladness to have participated were also included. In addition, semistructured telephone interviews were conducted with 60 screenees, stratified by screening outcome and gender. Results The follow up questionnaire was completed by 94% of screenees. Responses indicated a high level of satisfaction with the procedure: 99% were satisfied with the information given before the test, the facilities, the attitudes of the staff, and the explanation of their results; 91% reported only mild or no pain; 97% reported little or no embarrassment; and 99% were glad they had the test. Satisfaction ratings varied little by gender or outcome group. The quantitative results were reinforced by the qualitative data, which also revealed high acceptability. Conclusion In the context of a clinical trial with dedicated trial staff, FS is a well tolerated procedure. There are high levels of satisfaction with service provision and positive attitudes towards the programme.
The effect of varying the screening interval on false positives and duration of undiagnosed disease in a screening programme for type 2 diabetes
Authors: Park P.J. , Griffin S.J. , Duffy S.W. , Wareham N.J. 
Published: October 2002

Objectives The aims of this study were to quantify the proportion of people diagnosed as having type 2 diabetes by standard 75 g oral glucose tolerance test, in a hypothetical screening programme, who would actually be false positives (false positive percentage), and the effect on the false positive percentage of varying the time between repeat screens. We also calculated the duration in person years of exposure to undiagnosed disease in the population for each screening interval. Setting Ely, Cambridgeshire, UK. Methods We used the glucose tolerance data from 965 participants of the Ely Diabetes Project, who were tested 4.5 years apart, to calculate the population's between and within person variance for 2 hour plasma glucose, and constructed a probability matrix of observed v true glucose tolerance categories. The progression of the population between glucose tolerance categories was modelled assuming exponential times to progression. Results After one year, 47.5% of test positives were disease free: almost half of those labelled with diabetes would not have the disease. For a 5 year interval, the false positive percentage was 27.6%, but the population would have been exposed to undiagnosed diabetes for 144 person years. Conclusions Screening can be associated with both benefit and harm; the balance is dependent on characteristics of the disease and the screening programme. This study has quantified the trade off between exposure to undiagnosed diabetes and false positive results to inform the debate about screening for type 2 diabetes.
Prevalence and risk factors of work related asthma by industry among United States workers: data from the third national health and nutrition examination survey (1988–94)
Authors: Arif A A , Whitehead L W , Delclos G L , Tortolero S R , Lee E S 
Published: October 2002

Objectives:To estimate the prevalence of work related asthma and work related wheezing in United States workers. To identify high risk industries that could be targeted for future intervention. To determine the population attributable risk of work related asthma and work related wheezing.Methods:The third national health and nutrition examination survey, 1988–1994 (NHANES III) was analyzed to determine the prevalence of work related asthma and wheezing and to identify initially defined industries at risk among United States workers aged 20 and older. Separate logistic models were developed with work related asthma and work related wheezing as outcomes. Work related asthma was defined as affirmative response to questions on self reported physician diagnosed asthma and work related symptoms of rhinitis, conjunctivitis, and asthma. Work related wheezing was defined as affirmative response to questions on self reported wheezing or whistling in the chest in the previous 12 months and work related symptoms of rhinitis, conjunctivitis, and asthma. All analyses were adjusted for age, sex, smoking, and atopy.Results:The prevalence of work related asthma was 3.70% (95% confidence interval (95% CI) 2.88 to 4.52) and the prevalence of work related wheezing was 11.46% (95% CI 9.87 to 13.05). The main industries identified at risk of work related asthma and wheeze included the entertainment industry; agriculture, forestry, and fishing; construction; electrical machinery; repair services; and lodging places. The population attributable risk for work related asthma was 36.5% and work related wheezing was 28.5%.Conclusions:The findings provide impetus for further research and actions by public health professionals which prioritise occupational asthma on the public health agenda. Future intervention strategies need to be developed for effective control and prevention of asthma in the workplace.
Coupled microstrip filters on multilayered dielectric media
Authors: Koufogiannidis Ar. , Siakavara K 
Published: October 2002

The work presented in this paper is an attempt to design filters with coupled microstrip lines on multilayered dielectric media using methods employed in other applications. A procedure was formulated for designing filters with the desired frequency response and smaller size using insertion loss method combined with the theory of multiconductor transmission lines. The frequency response was verified by considering that the filters act as cascaded four-port networks. The results were in a very good agreement with those expected from the theoretically design procedure. PACS No.: 84.40D
Electrohydrodynamic instability in a horizontal viscoelastic fluid layer in the presence of internal heat generation
Authors: Othman M IA , Sweilam N H 
Published: October 2002

Linear stability theory is applied to examine the effect of a vertical ac electric field on the stability of natural convection, which occurs in a dielectric viscoelastic fluid (Walters' liquid B' ) between two parallel horizontal plates with internal heat generation. The power-series method is used to obtain the eigenvalue equation, which is then solved numerically. Critical heat Rayleigh numbers and the critical wave number for the onset of instability are presented graphically as functions of the electric Rayleigh number for various values of the Prandtl number. PACS No.: 47.15Fe
The run of a golf ball
Authors: Penner A R 
Published: October 2002

The run, which includes both the bounce and the roll, of a golf ball landing on turf is modeled. The effect of launch speed, impact angle, backspin, and green firmness on the run for a variety of golf shots is considered. It is found that the dominant factor that determines the length of the run, in the case of drives, is the impact angle. It is also found that for high-lofted iron shots, where the golf ball is given sufficient backspin, the ball may, for firm enough greens, initially bounce forward before running backwards. PACS No.: 01.80+b
Photoluminescence properties study of the Au/Au2S nanoshell
Authors: Diao J J , Qiu F S , Chen G D , Xi C , Song Y 
Published: October 2002

Photoluminescence experimental results of the Au/Au2S nanoshell (a nanometer-scale Au2S core coated by a thin Au shell) are presented in this note. An enhanced photoluminescence peak of Au coated Au2S is obtained near the bluegreen region, compared with the photoluminescence region of bulk Au2S, which is near the orangered region. The quantum-size effect and the core/shell nanostructure caused the blueshift photoluminescence of the Au2S/Au nanoshell. PACS Nos.: 81.05Ys, 78.55-m
A MICROSTATES APPROACH TO RELATIVE FREE ENTROPY
Authors: SHLYAKHTENKO DIMITRI 
Published: October 2002

We introduce a microstates-based notion of relative free entropy. This quantity is a microstates analog of Voiculescu's microstates-free relative entropy χ*(X1,…,Xn:B), and coinsides with his microstates entropy in the case that the algebra B consists of just mulitplies of identity. More generally, there is a formula relating the two in the case that B is a matrix algebra. We discuss several properties of our relative entropy, including maximization results and an infinitesimal change of variables formula.
REGULAR OBJECTS, MULTIPLICATIVE UNITARIES AND CONJUGATION
Authors: PINZARI C. , ROBERTS J. E. 
Published: October 2002

The notion of left (respectively right) regular object of a tensor C*-category equipped with a faithful tensor functor into the category of Hilbert spaces is introduced. If such a category has a left (respectively right) regular object, it can be interpreted as a category of corepresentations (respectively representations) of some multiplicative unitary. A regular object is an object of the category which is at the same time left and right regular in a coherent way. A category with a regular object is endowed with an associated standard braided symmetry. Conjugation is discussed in the context of multiplicative unitaries and their associated Hopf C*-algebras. It is shown that the conjugate of a left regular object is a right regular object in the same category. Furthermore the representation category of a locally compact quantum group has a conjugation. The associated multiplicative unitary is a regular object in that category.
A THEORY OF JET DEFINITION
Authors: TKACHOV FYODOR V. 
Published: October 2002

A systematic framework for jet definition is developed from first principles of physical measurement, quantum field theory, and QCD. A jet definition is found which: • is theoretically optimal in regard of both minimization of detector errors and inversion of hadronization; • is similar to a cone algorithm with dynamically negotiated jet shapes and positions found via shape observables that generalize the thrust to any number of axes; • involves no ad hoc conventions; • allows a fast computer implementation.7 The framework offers an array of options for systematic construction of quasi-optimal observables for specific applications.
FINDING CONFORMAL KILLING VECTORS FROM THE INVARIANT CLASSIFICATION SCHEME
Authors: EDGAR BRIAN , LUDWIG GARRY 
Published: October 2002

The invariant classification (Karlhede classification)1 of a particular spacetime fixes (up to isotropy) an intrinsic tetrad for the spacetime, in terms of the Riemann tensor and its derivatives. Exploiting this tetrad, it has been shown how to determine the number of Killing vectors which exist 2, and also whether a proper homothetic Killing vector exists 3. The first part of the talk outlined a procedure for finding explicitly homothetic and Killing vectors by exploiting the symmetry properties of the intrinsic tetrad 4,5. In general, it is not always possible to use this same tetrad to investigate proper conformal Killing vectors by the same methods. In this talk it was suggested to modify the invariant classification procedure so that only conformally invariant conditions are used for fixing the tetrad in terms of the Riemann tensor and its derivatives. This would mean that the existence of proper conformal Killing vectors could be deduced directly from the modified invariant classification scheme, and then found explicitly 6.
SCALAR PERTURBATIONS IN A PRIMORDIAL INFLATIONARY SCENARIO
Authors: FABRIS J. , SPINDEL Ph. 
Published: October 2002

We compute the spectral index for scalar perturbations generated in a primordial inflationary model2. In this model, the transition of the inflationary phase to the radiative era is achieved through the decay of the cosmological term leading a second order phase transition and the characteristics of the model allow to implement a set of initial conditions where the perturbations display a thermal spectrum when they emerge from the horizon. [Formula: see text] The obtained value for the spectral index is equal to 2, a result that depends very weakly on the various parameters of the model and on the initial conditions used. This "negative" result pleads for the standard inflationary scenario, but of course cannot prove it and the problem of the interpretation of the inflaton remains open2.
EINSTEIN'S EQUIVALENCE PRINCIPLE AND THE GRAVITATIONAL RED SHIFT
Authors: FLORIDES PETROS S. 
Published: October 2002

Long before the general theory of relativity was finally formulated in 1916, it was claimed that the following argument, based on (the strong) Einstein's equivalence principle (EP for short), predicted the well known and experimentally observed phenomenon of the gravitational red shift; precisely the same argument is being used to this day in almost all books on general relativity to derive the same phenomenon (see, for example, Refs. 1, 2): Consider "Einstein's elevator" at rest on the Earth's surface with an emitter (E) fixed on the floor of the elevator, and a receiver (R) fixed on the ceiling directly above E and distance h from it. Let E send light signals, at frequency νE, to R and let the frequency at which they are received by R be νR. To find the relationship between νE and νR we invoke the EP and consider, instead, E and R as fixed in an elevator which is accelerating relative to an inertial frame S in gravitation-free space with constant acceleration g in the direction [Formula: see text], g being the acceleration due to gravity on the Earth's surface. At time t = 0, when E is assumed to be at rest in S, E emits a light wave towards R. The time it takes the wave to reach R is roughly t = h/c, where c is the speed of light in S. But in this time R has acquired the velocity [Formula: see text] and, therefore, there is a consequent Doppler shift given by [Formula: see text]. By the EP the same result must hold when E and R are fixed near the Earth's surface. In this case gh = △Φ = Φ(R) - Φ(E), so that in the Earth's gravitational field we have [Formula: see text], which is the standard formula for the gravitational red shift. Simple and straight forward as the above argument may seem, we shall show in this lecture that it is, in fact, fundamentally flawed in two important respects. We shall present a new argument, entirely within the framework of classical mechanics (just as the above argument), which is free from these two flaws. Alas!, it leads to zero gravitational red shift for the case dealt with in the above argument. It is argued that this result not only does it not invalidate the general theory of relativity but it strengthens it; for, the full theory of general relativity alone, irrespective of its historical development, can correctly and unambiguously predict the observed gravitational red shift.
NEW LOWER BOUNDS FOR WARP DRIVE ENERGY
Authors: GAUTHIER C. , GRAVEL P. , MELANSON J. 
Published: October 2002

The introduction of the warp drive metric by Alcubierre1 has aroused great interest over the past few years. Using an uncertainty-type principle, Ford and Pfenning2 proved that the warp drive transport of a spaceship in a regular bubble having a radius of 100 m is unrealistic. However, Van Den Broeck3 has shown that the situation largely improves when one uses a warp drive bubble with a small surface area and large spatial volume. Putting aside many physics problems related to the realization of the warp drive concept, we show in this paper4 how to modify Van Den Broeck's idea to improve his results. We find new lower bounds for the warp drive energy by working on parameters whose latitude has never been considered before. We also consider micro warp drive bubbles which can be treated as physical entities of their own and could possibly be used to transmit information faster than the speed of light. The conditions prevailing just after the Big Bang allow the spontaneous formation of such micro bubbles which could still be present in our period of time.
CONSERVED CURRENT FOR GENERAL TELEPARALLEL MODELS
Authors: ITIN Y. 
Published: October 2002

The obstruction for the existence of an energy-momentum tensor for the gravitational field in GR is connected with vanishing of first order invariants in (pseudo) Riemannian geometry. This specific geometric property is not valid in alternative geometrical structures1,2. A parallelizable differentiable 4D-manifold endowed with a class of smooth coframe fields ϑa is considered. A general 3-parameter class of global Lorentz invariant teleparallel models is considered. It includes a 1-parameter subclass of models with the Schwarzschild coframe solution (generalized teleparallel equivalent of gravity) 3. By introducing the notion of a 3-parameter conjugate field strength F linear in the strength Ca = dϑa the coframe Lagrangian is rewritten in the Maxwell-Yang-Mills form L = 1/2Fa ∧ Ca. The field equation turns out to have a form d * Fa = Ta completely similar to the Maxwell field equation. By applying the Noether procedure, the source 3-form Ta is shown to be connected with the diffeomorphism invariance of the Lagrangian. Thus the source Ta of the coframe field is interpreted as the total conserved energy-momentum current of the coframe field and matter4. The energy-momentum tensor is defined as a map of the module of current 3-forms into the module of vector fields 5. Thus an energy-momentum tensor for the coframe is defined in a diffeomorphism invariant and a translational covariant way. The total energy-momentum current of a system is conserved. Thus a redistribution of the energy-momentum current between material and coframe (gravity) field is possible in principle, unlike as in the standard GR. The result is: The standard GR has a neighborhood of viable models with the same Schwarzschild solutions. These models however have a better Lagrangian behavior and produce an invariant energy-momentum tensor.