4,997 research outputs found
Dental erosion: In vitro model of wine assessor's erosion
The document attached has been archived with permission from the Australian Dental Association. An external link to the publisherâs copy is included.Background: Wine makers and assessors frequently experience severe dental erosion. The objectives of this study were to develop an in vitro model of dental erosion caused by frequent wine contact with teeth, and to use this model to assess the effectiveness of a variety of methods which might protect against this form of erosion. Methods: An initial pilot study found that riesling style wine was more erosive than champagne style, and both more than claret. Wine tasting was simulated by subjecting exposed windows of enamel and root surfaces on 50 intact, extracted human teeth to 1400 one minute exposures to white wine (pH 3.2). A variety of dental materials were applied to the exposed windows on groups of teeth prior to erosive challenge, to assess their protective ability. Results: Protective resin coatings and fluoride varnishes protected both enamel and roots against wine induced erosion. A high degree of protection was provided by APF gel, with less by NaF gel. Conclusions: It was concluded that dentists may be able to help minimise erosion resulting from frequent wine-tasting in their patients by the clinical application of one or a combination of these agents at times prior to prolonged assessment periods.Tong Bee Mok, J McIntyre and D Hun
Quasi-Experimental Evidence on the Effects of Unemployment Insurance from New York State
This paper examines unemployment duration and the incidence of claims following a 36 percent increase in the maximum weekly benefit in New York State. This benefit increase sharply increased benefits for a large group of claimants, while leaving them unchanged for a large share of claimants who provide a natural comparison group. The New York benefit increase has the special features that it was unexpected and applied to in-progress spells. These features allow the effects on duration to be convincingly separated from effects on incidence. The results show a sharp fall in the hazard of leaving UI that coincides with the increase in benefits. The evidence is also consistent with a substantial effect of the benefit level on the incidence of claims and with this change in incidence biasing duration estimates. The evidence further suggests that, at least in this case, standard methods that identify duration effects through nonlinearities in the benefit schedule are not badly biased.
Making co-enrolment feasible for randomised controlled trials in paediatric intensive care.
Enrolling children into several trials could increase recruitment and lead to quicker delivery of optimal care in paediatric intensive care units (PICU). We evaluated decisions taken by clinicians and parents in PICU on co-enrolment for two large pragmatic trials: the CATCH trial (CATheters in CHildren) comparing impregnated with standard central venous catheters (CVCs) for reducing bloodstream infection in PICU and the CHIP trial comparing tight versus standard control of hyperglycaemia
VALIDATION OF MODEL-BASED IMAGE-MATCHING TECHNIQUE WITH BONE-PIN MARKER BASED MOTION ANALYSIS ON ANKLE KINEMATICS: A CADAVER STUDY
Krosshaug (2005) introduced a model-based image-matching (MBIM) technique for 3D reconstruction of human motion from uncalibrated video sequences. The aim of this study is to validate the MBIM technique on ankle joint movement with the reference to bone-pin marker based motion analysis on a cadaver. One cadaveric below-hip specimen was prepared for performing full-range plantarflexion/dorsiflexion, inversion/eversion and relative circular motion between two segments. The videos were recorded and analyzed by the MBIM technique and bone-pin marker based motion analysis. The results are presented as the qualitative visual evaluation and the root mean square (RMS) error. In general, the validation results showed good agreement between the MBIM estimation and bone-pin marker based motion analysis results. This technique will contribute to the motion measurement of ankle joint kinematics in the future, for instance, the motion analysis in real game situations and understanding the injury mechanisms of real injury cases
Two-Component Fokker-Planck Models for the Evolution of Isolated Globular Clusters
Two-component (normal and degenerate stars) models are the simplest
realization of clusters with a mass spectrum because high mass stars evolve
quickly into degenerates, while low mass stars remain on the main-sequence for
the age of the universe. Here we examine the evolution of isolated globular
clusters using two-component Fokker-Planck (FP) models that include heating by
binaries formed in tidal capture and in three-body encounters. Three-body
binary heating dominates and the postcollapse expansion is self-similar, at
least in models with total mass M <= 3 x 10^5 M_\odot, initial half-mass radius
r_{h,i} >= 5 pc, component mass ratio m_2/m_1 <= 2, and number ratio N_1/N_2 <=
300 when m_2=1.4 M_\odot. We derive scaling laws for \rho_c, v_c, r_c, and r_h
as functions of m_1/m_2, N, M, and time t from simple energy-balance arguments,
and these agree well with the FP simulations. We have studied the conditions
under which gravothermal oscillations (GTOs) occur. If E_{tot} and E_c are the
energies of the cluster and of the core, respectively, and t_{rh} and t_c are
their relaxation times, then \epsilon \equiv (E_{tot}/t_{rh})/(E_c/t_{rc}) is a
good predictor of GTOs: all models with \epsilon>0.01 are stable, and all but
one with \epsilon < 0.01 oscillate. We derive a scaling law for \epsilon
against N and m_1/m_2 and compared with our numerical results. Clusters with
larger m_2/m_1 or smaller N are stabler.Comment: 15 pages (LaTeX) with 8 figures. To appear in ApJ March 10, 1998
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A new method of calculation of Franck-Condon factors which includes allowance for anharmonicity and the Duschinsky effect : simulation of the He I photoelectron spectrum of ClOâ
2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
In vitro characterisation of immunosuppressive activity of triptolide
published_or_final_versio
MODEL-BASED IMAGE-MATCHING KINEMATICS ANALYSIS OF THREE ANKLE SUPINATION SPRAIN INJURY CASES IN SPORTS
Ankle sprain is one of the most common injuries encountered at sport events. Three ankle supination sprain cases from high jump, tennis and hockey were chosen for analysis. Model-Based Image-Matching (MBIM) technique was implemented for reconstructing 3D ankle joint kinematics. The profiles of ankle joint kinematics were outputted from the selected sprain cases. The maximum inversion angle ranged from 78° to 142°. Plantarflexion was again found to be not necessary in ankle supination sprain injury. The results from the MBIM technique would contribute to the understanding of biomechanical injury mechanism of ankle supination sprain injury in sports. The future direction is to analyze more cases to consolidate the findings
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