3,247 research outputs found
Patient-Reported Outcomes Measurement Information System physical function correlates with Toronto Extremity Salvage Score in an orthopaedic oncology population
Background: The National Institute of Health\u27s Patient-Reported Outcomes Measurement Information System (PROMIS) uses computerised-adaptive testing to reduce survey burden and improve sensitivity. PROMIS is being used across medical and surgical disciplines but has not been studied in orthopaedic oncology.
Questions/purposes: The aim of the study was to compare PROMIS measures with upper extremity (UE) and lower extremity (LE) Toronto Extremity Salvage Score (TESS) by assessing the following: (1) responder burden, (2) correlation between scores and (3) floor/ceiling effects.
Patients and methods: This cross-sectional trial analysed all 97 adult patients treated surgically for a bone or soft tissue tumour at a tertiary institution between November 2015 and March 2016. TESS (UE or LE) and PROMIS (Physical Function, Pain Interference and Depression) surveys were administered preoperatively. Pearson correlations between each PROMIS domain and TESS were calculated, as were floor/ceiling effects of each outcome measure.
Results: (1) Completion of three PROMIS questionnaires required a mean total of 16.8 (+/- 5.8 standard deviation) questions, compared with 31 and 32 questions for the LE and UE TESS questionnaires, respectively. (2) The PROMIS Physical Function scores demonstrated a strong positive correlation with the LE TESS (r = 0.84; 95% confidence interval [CI], 0.72-0.91; p \u3c 0.001) and moderate positive correlation with the UE TESS (r = 0.64; 95% CI, 0.34-0.83; p = 0.055). The PROMIS Depression scores demonstrated a weak negative correlation with both the LE TESS (r = -0.38; 95% CI, -0.61 to -0.10; p = 0.010) and with UE TESS (r = -0.38; 95% CI, -0.67 to -0.01; p = 0.055). The PROMIS Pain Interference scores demonstrated a strong negative correlation with the LE TESS (r = -0.71; 95% CI, -0.83 to -0.52; p \u3c 0.001) and a moderate negative correlation with the UE TESS (r = -0.62; 95% CI, -0.81 to -0.30; p = 0.001). (3) The UE TESS had a range of scores from 16 to 100 with a 27% ceiling effect and no floor effect, and the LE TESS had a range from 10 to 98 with no floor or ceiling effect. There was no floor or ceiling effect for any PROMIS measures.
Conclusions: In an orthopaedic oncology population, the PROMIS Physical Function and Pain Interference scores correlate with the TESS and have the benefit of reduced survey burden and ceiling effect. The PROMIS Depression scores may provide additional information regarding patient outcomes not captured by the TESS.
Level of Evidence: Level III.
The translational potential of this article: Patient reported outcome measures asses patients\u27 symptoms, function and health-related quality of life and are designed to capture more clinical information than can be gathered by objective medial testing alone. As reimbursements and the understanding of patient outcomes are becoming tied to performance on PROMIS measures, it is an important step to establish how PROMIS measures correlate and compare to traditional legacy measures
Modeling the Effects of Beam Size and Flaw Morphology on Ultrasonic Pulse/Echo Sizing of Delaminations in Carbon Composites
The size and shape of a delamination in a multi-layered structure can be estimated in various ways from an ultrasonic pulse/echo image. For example the -6dB contours of measured response provide one simple estimate of the boundary. More sophisticated approaches can be imagined where one adjusts the proposed boundary to bring measured and predicted UT images into optimal agreement. Such approaches require suitable models of the inspection process. In this paper we explore issues pertaining to model-based size estimation for delaminations in carbon fiber reinforced laminates. In particular we consider the influence on sizing when the delamination is non-planar or partially transmitting in certain regions. Two models for predicting broadband sonic time-domain responses are considered: (1) a fast "simple" model using paraxial beam expansions and Kirchhoff and phase-screen approximations; and (2) the more exact (but computationally intensive) 3D elastodynamic finite integration technique (EFIT). Model-to-model and model-to experiment comparisons are made for delaminations in uniaxial composite plates, and the simple model is then used to critique the -6dB rule for delamination sizing
Ion Charge States in Halo CMEs: What can we Learn about the Explosion?
We describe a new modeling approach to develop a more quantitative
understanding of the charge state distributions of the ions of various elements
detected in situ during halo Coronal Mass Ejection (CME) events by the Advanced
Composition Explorer (ACE) satellite. Using a model CME hydrodynamic evolution
based on observations of CMEs propagating in the plane of the sky and on
theoretical models, we integrate time dependent equations for the ionization
balance of various elements to compare with ACE data. We find that plasma in
the CME ``core'' typically requires further heating following filament
eruption, with thermal energy input similar to the kinetic energy input. This
extra heating is presumably the result of post eruptive reconnection. Plasma
corresponding to the CME ``cavity'' is usually not further ionized, since
whether heated or not, the low density gives freeze-in close the the Sun. The
current analysis is limited by ambiguities in the underlying model CME
evolution. Such methods are likely to reach their full potential when applied
to data to be acquired by STEREO when at optimum separation. CME evolution
observed with one spacecraft may be used to interpret CME charge states
detected by the other.Comment: 20 pages, accepted by Ap
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Bayesian and Maximum Likelihood Phylogenetic Analyses of Protein Sequence Data Under Relative Branch-Length Differences and Model Violation
Background: Bayesian phylogenetic inference holds promise as an alternative to maximum likelihood, particularly for large molecular-sequence data sets. We have investigated the performance of Bayesian inference with empirical and simulated protein-sequence data under conditions of relative branch-length differences and model violation. Results: With empirical protein-sequence data, Bayesian posterior probabilities provide more-generous estimates of subtree reliability than does the nonparametric bootstrap combined with maximum likelihood inference, reaching 100% posterior probability at bootstrap proportions around 80%. With simulated 7-taxon protein-sequence datasets, Bayesian posterior probabilities are somewhat more generous than bootstrap proportions, but do not saturate. Compared with likelihood, Bayesian phylogenetic inference can be as or more robust to relative branch-length differences for datasets of this size, particularly when among-sites rate variation is modeled using a gamma distribution. When the (known) correct model was used to infer trees, Bayesian inference recovered the (known) correct tree in 100% of instances in which one or two branches were up to 20-fold longer than the others. At ratios more extreme than 20-fold, topological accuracy of reconstruction degraded only slowly when only one branch was of relatively greater length, but more rapidly when there were two such branches. Under an incorrect model of sequence change, inaccurate trees were sometimes observed at less extreme branch-length ratios, and (particularly for trees with single long branches) such trees tended to be more inaccurate. The effect of model violation on accuracy of reconstruction for trees with two long branches was more variable, but gamma-corrected Bayesian inference nonetheless yielded more-accurate trees than did either maximum likelihood or uncorrected Bayesian inference across the range of conditions we examined. Assuming an exponential Bayesian prior on branch lengths did not improve, and under certain extreme conditions significantly diminished, performance. The two topology-comparison metrics we employed, edit distance and Robinson-Foulds symmetric distance, yielded different but highly complementary measures of performance. Conclusions: Our results demonstrate that Bayesian inference can be relatively robust against biologically reasonable levels of relative branch-length differences and model violation, and thus may provide a promising alternative to maximum likelihood for inference of phylogenetic trees from protein-sequence data
Étude de l'absorption des phosphates, azote, chrome et cadmium par trois algues vertes isolées à partir d'effluents urbains
La capacité de déphosphatation et de dénitrification ainsi que la sensibilité et l'accumulation de deux métaux lourds (Cr et Cd) de Scenedesmus quadricauda, Chlorella pyrenoidosa et Chlamydomonas reinhardtii isolées des eaux usées de la ville de Fès, ont été étudiées dans les conditions de laboratoire. Les résultats ont montré que S. quadricauda présente les meilleurs taux de réduction des phosphates (83%), et d'ammonium (75%). L'étude de la sensibilité vis à vis du chrome et du cadmium des trois espèces, a montré qu'au delà d'une concentration de 1 ppm, la croissance se trouve réduite et que S. quadricauda présente une sensibilité plus faible que les deux autres espèces. Les résultats des expériences d'absorption conduites avec du chrome VI marqué au51 Cr et du cadmium marqué au109 Cd ont montré que les quantités de chrome et du cadmium prélevées par S. quadricauda dépassent celles des deux autres espèces. L'utilisation potentielle des trois espèces dans le traitement des effluents urbains est discutée à la lumière des résultats de ces expériences.Wastewater discharge is an environmental problem, especially in developing countries. Biological wastewater treatment seems to be an alternative for these countries due to its low cost. Algae are used in such wastewater treatment systems in many parts of the world. In addition to preventing environmental damage, the reuse of treated wastewater can be an alternative water supply in arid regions and during drought periods.In this paper, three algal (Chlamydomonas reinhardtii, Chlorella pyrenoïdosa and Scenedesmus quadricauda) species were isolated from an urban effluent collected from a Mediterranean city (Fez, Morocco, situated between 4° to 7° W and 33° to 35° N) and their ability to remove phosphate and nitrogen was tested under laboratory conditions. The toxicity and uptake of chromium and cadmium were also studied.Fez city wastewater was sampled monthly during one year (2000) at three main stations located along the Boukhrareb stream which crosses the city. The following parameters were measured according to methods described by RODIER J. (1996): Chemical oxygen demand, COD; Biological oxygen demand, BOD; NO3 -; NH4 +; PO43 -; electrical conductivity (EC) and organic matter. Heavy metals (Cr, Fe and Zn) were measured by INAA (Instrumental Thermal Neutron Activation Analysis) in wastewater samples dried on Teflon sheets at 70°C.The collected samples were incubated under controlled conditions and species of alga were identified, isolated, and then transferred to fresh culture medium. Chlamydomonas reinhardtii, Chlorella pyrenoïdosa and Scenedesmus quadricauda were chosen for these experiments because of their abundance in wastewater over the year and for their capacities for biomass production. The removal of nutrients from aqueous media was studied by using monospecific cultures. Algae were in the exponential growth phase when the experiments were started and BG11 culture medium was used under standard growth conditions. Initial concentrations of phosphate and nitrogen were 2.24 mg×L-1 (PO43 -), 12.84 mg×L-1 (NO3 -) and 0.26 mg×L-1 (N-NH4 +). The concentrations decreased during the experimental period, and degrees of removal ranged from 83 to 75% for phosphate, from 85 to 77% for nitrogen and from 52 to 75% for ammonium.To evaluate the sensitivity of the algal cells to heavy metals, the algal strains were exposed for one week to chromium as K2Cr2O7 and cadmium as CdCl2 at concentrations of 0.1, 0.5, 1, 1.5 and 2 ppm (mg×L-1) of Cr or Cd. Culture growth was monitored by microscopic counting of algal cells to determine quantitative biomass changes. Results demonstrated that growth inhibition occurred at 1 ppm Cr and Cd, whereas levels of 1.5 and 2 ppm of both metals were lethal to the cultures, but no effect on growth was seen in algae exposed to 0.1 ppm of Cd or 0.1 ppm of Cr. Scenedesmus quadricauda was more resistant than Chlamydomonas reinhardtii and Chlorella pyrenoïdosa to chromium and cadmium.Radiotracers (51Cr and 109Cd) were used to trace the biosorption of chromium and cadmium by the three algal strains. Cr(VI) as K2 Cr2O7 and Cd as CdCl2 were added to the algal suspension culture to give concentrations of 1, 1.5 and 2 ppm Cd and Cr respectively. At various stages during growth of the unialgal cultures, samples were removed, a pulse of51 Cr or109 Cd was added, and the uptake rates of Cr(VI) and Cd were determined. To evaluate the amount of heavy metals removed by the algal cells, microscopic cell counting was carried out. All the experiments were conducted under the above-mentioned conditions for each concentration studied, the measurements were repeated three times and the mean values from the three replicates were calculated. The results showed that chromium and cadmium removal by algae was dependent on the metal concentration in the culture medium. The quantity of metal removed also varied with algal species, where 20 µg, 23 µg and 35 µg of Cd were accumulated by 106 cells of Chlorella, Chlamydomonas and Scenedesmus respectively at a metal concentration of 2 ppm. About 25 µg of Cr were accumulated by 106 cells of Chlorella and Chlamydomonas whereas, 106 cells of Scenedesmus accumulated 32 µg of Cr at a concentration of 2 ppm.The experimental data presented here demonstrated that there was not a great difference in the uptake capabilities between the three algal strains, and reaffirmed the potential of algae in the purification of metal-contaminated wastewater. This wastewater treatment system has many advantages and it is an efficient way to significantly reduce the release of nutrients (e.g., phosphorus, nitrogen, ammonia) and heavy metals (e.g., chromium and cadmium)
Some Inverse Problems for the Burgers Equation and Related Systems
In this article we deal with one-dimensional inverse problems concerning the
Burgers equation and some related nonlinear systems (involving heat effects
and/or variable density). In these problems, the goal is to find the size of
the spatial interval from some appropriate boundary observations of the
solution. Depending on the properties of the initial and boundary data, we
prove uniqueness and non-uniqueness results. In addition, we also solve some of
these inverse problems numerically and compute approximations of the interval
sizes
Stimulants for enhancement purposes: perceptions attitudes, usage among university students
Objective: Determine perceptions, attitudes, and usage of non medical prescription stimulants among students at a Midwestern technology focused university. Participants: 241 university students. Methods: Data was collected in March 2015 through an anonymous web survey. A logistic regression model evaluated predictors. T-test was used to evaluate differences between groups. Results: 9.5% had used prescription stimulants without a valid prescription. Primary motives were academic preparation (78%) and recreation (61%). Nicotine use (OR = 8.99, CI 2.40, 33.77, p \u3c .01), peer\u27s suggestion (OR = 6.95, C12.21, 21.84, p \u3c .01), and positive attitudes toward use (OR = 1.99, CI 1.06, 3.72, p \u3c .05) increased odds of nonmedical use. Users and non-users differed in estimations of nonmedical use within peers (t (239) = 3.17, p \u3c .01) and in their field (t (239) = 3.22, p \u3c .01). Conclusions: Administrators should acknowledge student use and develop strategies to address it
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