Phenomenological Constraints on the Transport Properties of QCD Matter with Data-Driven Model Averaging.

Using combined data from the Relativistic Heavy Ion and Large Hadron Colliders, we constrain the shear and bulk viscosities of quark-gluon plasma (QGP) at temperatures of ∼150-350 MeV. We use Bayesian inference to translate experimental and theoretical uncertainties into probabilistic constraints for the viscosities. With Bayesian model averaging we propagate an estimate of the model uncertainty generated by the transition from hydrodynamics to hadron transport in the plasma's final evolution stage, providing the most reliable phenomenological constraints to date on the QGP viscosities.

The effect of aluminium and sodium impurities on the in vitro toxicity and pro-inflammatory potential of cristobalite.

BACKGROUND: Exposure to crystalline silica (SiO2), in the form of quartz, tridymite or cristobalite, can cause respiratory diseases, such as silicosis. However, the observed toxicity and pathogenicity of crystalline silica is highly variable. This has been attributed to a number of inherent and external factors, including the presence of impurities. In cristobalite-rich dusts, substitutions of aluminium (Al) for silicon (Si) in the cristobalite structure, and impurities occluding the silica surface, have been hypothesised to decrease its toxicity. This hypothesis is tested here through the characterisation and in vitro toxicological study of synthesised cristobalite with incremental amounts of Al and sodium (Na) dopants. METHODS: Samples of synthetic cristobalite with incremental amounts of Al and Na impurities, and tridymite, were produced through heating of a silica sol-gel. Samples were characterised for mineralogy, cristobalite purity and abundance, particle size, surface area and surface charge. In vitro assays assessed the ability of the samples to induce cytotoxicity and TNF-α production in J774 macrophages, and haemolysis of red blood cells. RESULTS: Al-only doped or Al+Na co-doped cristobalite contained between 1 and 4 oxide wt% Al and Na within its structure. Co-doped samples also contained Al- and Na-rich phases, such as albite. Doping reduced cytotoxicity to J774 macrophages and haemolytic capacity compared to non-doped samples. Al-only doping was more effective at decreasing cristobalite reactivity than Al+Na co-doping. The reduction in the reactivity of cristobalite is attributed to both structural impurities and a lower abundance of crystalline silica in doped samples. Neither non-doped nor doped crystalline silica induced production of the pro-inflammatory cytokine TNF-α in J774 macrophages. CONCLUSIONS: Impurities can reduce the toxic potential of cristobalite and may help explain the low reactivity of some cristobalite-rich dusts. Whilst further work is required to determine if these effects translate to altered pathogenesis, the results have potential implications for the regulation of crystalline silica exposures.

The global variability of diatomaceous earth toxicity: a physicochemical and in vitro investigation.

BACKGROUND: Diatomaceous earth (DE) is mined globally and is potentially of occupational respiratory health concern due to the high crystalline silica content in processed material. DE toxicity, in terms of variability related to global source and processing technique, is poorly understood. This study addresses this variability using physicochemical characterisation and in vitro toxicology assays. METHODS: Nineteen DE samples sourced from around the world, comprising unprocessed, calcined and flux-calcined DE, were analysed for chemical and mineral composition, particle size and morphology, and surface area. The potential toxicity of DE was assessed by its haemolytic capacity, and its ability to induce cytotoxicity or cytokine release by J774 macrophages. RESULTS: The potential toxicity of DE varied with source and processing technique, ranging from non-reactive to as cytotoxic and haemolytic as DQ12. Crystalline silica-rich, flux-calcined samples were all unreactive, regardless of source. The potential toxicity of unprocessed and calcined samples was variable, and did not correlate with crystalline silica content. Calcium-rich phases, iron content, amorphous material, particle size and morphology all appeared to play a role in sample reactivity. An increased surface area was linked to an increased reactivity in vitro for some sample types. CONCLUSIONS: Overall, no single property of DE could be linked to its potential toxicity, but crystalline silica content was not a dominant factor. Occlusion of the potentially toxic crystalline silica surface by an amorphous matrix or other minerals and impurities in the crystal structure are suggested to pacify toxicity in these samples. In vivo verification is required, but these data suggest that crystalline silica content alone is not a sufficient indicator of the potential DE hazard.

Physicochemical and toxicological profiling of ash from the 2010 and 2011 eruptions of Eyjafjallajökull and Grímsvötn volcanoes, Iceland using a rapid respiratory hazard assessment protocol.

The six week eruption of Eyjafjallajökull volcano in 2010 produced heavy ash fall in a sparsely populated area of southern and south eastern Iceland and disrupted European commercial flights for at least 6 days. We adopted a protocol for the rapid analysis of volcanic ash particles, for the purpose of informing respiratory health risk assessments. Ash collected from deposits underwent a multi-laboratory physicochemical and toxicological investigation of their mineralogical parameters associated with bio-reactivity, and selected in vitro toxicology assays related to pulmonary inflammatory responses. Ash from the eruption of Grímsvötn, Iceland, in 2011 was also studied. The results were benchmarked against ash from Soufrière Hills volcano, Montserrat, which has been extensively studied since the onset of eruptive activity in 1995. For Eyjafjallajökull, the grain size distributions were variable: 2-13 vol% of the bulk samples were <4 µm, with the most explosive phases of the eruption generating abundant respirable particulate matter. In contrast, the Grímsvötn ash was almost uniformly coarse (<3.5 vol%<4 µm material). Surface area ranged from 0.3 to 7.7 m2 g(-1) for Eyjafjallajökull but was very low for Grímsvötn (<0.6 m2 g(-1)). There were few fibre-like particles (which were unrelated to asbestos) and the crystalline silica content was negligible in both eruptions, whereas Soufrière Hills ash was cristobalite-rich with a known potential to cause silicosis. All samples displayed a low ability to deplete lung antioxidant defences, showed little haemolysis and low acute cytotoxicity in human alveolar type-1 like epithelial cells (TT1). However, cell-free tests showed substantial hydroxyl radical generation in the presence of hydrogen peroxide for Grímsvötn samples, as expected for basaltic, Fe-rich ash. Cellular mediators MCP-1, IL-6, and IL-8 showed chronic pro-inflammatory responses in Eyjafjallajökull, Grímsvötn and Soufrière Hills samples, despite substantial differences in the sample mineralogy and eruptive styles. The value of the pro-inflammatory profiles in differentiating the potential respiratory health hazard of volcanic ashes remains uncertain in a protocol designed to inform public health risk assessment, and further research on their role in volcanic crises is warranted.

The experience of back pain in young Australians.

The usual activity level and history of low back pain was determined by questionnaire in 614 young Australians (9-27 years); dancers (25%), gymnasts (5%) and a control group who did not participate in dance or gymnastics for > or =6 hours/week during the previous three months (70%). These groups demonstrated significantly different activity levels (dancers >gymnasts >controls). Of all respondents, 34% experienced pain of more than two days duration in the previous year, and 50% in all previous years. The incidence and magnitude of pain in the previous year was significantly greater in the dancers and gymnasts (P<0.05) compared to the controls. The incidence of pain was not linked to the average total hours of activity until this exceeded 30 hours per week. There was no significant difference in the incidence of pain in the previous year between control group respondents who did and did not undertake regular activity. The average hours of activity per incident was approximately 20 hours for the dancers and approximately 5 hours for the other groups. This study has demonstrated that back pain in active and inactive adolescents presents a significant challenge for health-care practitioners involved in the management and prevention of symptomatic spinal disorders.

Remifentanil in the horse: identification and detection of its major urinary metabolite.

Remifentanil (4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic acid methyl ester) is a mu-opioid receptor agonist with considerable abuse potential in racing horses. The identification of its major equine urinary metabolite, 4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic+ ++ acid, an ester hydrolysis product of remifentanil is reported. Administration of remifentanil HCl (5 mg, intravenous) produced clear-cut locomotor responses, establishing the clinical efficacy of this dose. ELISA analysis of postadministration urine samples readily detected fentanyl equivalents in these samples. Mass spectrometric analysis, using solid-phase extraction and trimethylsilyl (TMS) derivatization, showed the urine samples contained parent remifentanil in low concentrations, peaking at 1 h. More significantly, a major peak was identified as representing 4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic+ ++ acid, arising from ester hydrolysis of remifentanil. This metabolite reached its maximal urinary concentrations at 1 h and was present at up to 10-fold greater concentrations than parent remifentanil. Base hydrolysis of remifentanil yielded a carboxylic acid with the same mass spectral characteristics as those of the equine metabolite. In summary, these data indicate that remifentanil administration results in the appearance of readily detectable amounts of 4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic+ ++ acid in urine. On this basis, screening and confirmation tests for this equine urinary metabolite should be optimized for forensic control of remifentanil.

Can 16-18-year-old elite ballet dancers improve their hip and ankle range of motion over a 12-month period?

OBJECTIVE: To determine the effect of a 12-month intensive ballet training regimen on hip and ankle range of motion in male and female, first- and second-year professional dancers. DESIGN: 12-month longitudinal follow-up. SETTING: National classical ballet school in Australia. PARTICIPANTS: 28 female and 20 male full-time ballet students with a mean +/- 1 SD, ages 16.8 +/- 0.8 and 17.7 +/- 1.2 years, respectively. MAIN OUTCOME MEASURES: Degrees of range of motion of left and right sides for the following movements: standing plié in parallel-passive ankle dorsiflexion (DF); standing turnout in the balletic first position--lower leg external rotation (LLER); supine hip external rotation (ER); supine hip internal rotation (IR). An additional range of motion was calculated: external rotation below the hip joint (BHER) derived by subtracting hip ER from LLER. MAIN RESULTS: In all subjects combined, hip and ankle ranges increased statistically on the right. However, the amount was generally minimal and most at the borderline of the amount of error associated with the measurement tool. While there was no change in LLER, there was a decrease in BHER. There were no overall gender differences, and year differences existed only for left hip ER and total hip ER with first-year dancers showing significant improvements in these ranges. For DF and sum of hip IR, first-year males and second-year females had increases in range. There was a negative relationship between baseline range and the amount of change over the 12 months. CONCLUSIONS: Dancers ages 16-18 years who enter full-time ballet training did not augment their ankle dorsiflexion to any appreciable degree. Some, but certainly not all, increased their hip active external rotation over 12 months without increasing their total lower limb turnout. Hip ER was more likely to improve in the first-year rather than second-year student in this elite full-time training school.

Lumbar spine range of motion as a measure of physical and functional impairment: an investigation of validity.

OBJECTIVE: To investigate the validity of the spinal range of motion models outlined in the second and fourth editions of the American Medical Association Guides to the evaluation of permanent impairment (AMA Guides), for assessing the percentage impairment in chronic low back pain patients. DESIGN: Cross-sectional validation study. SETTING: Outpatient department in the Rehabilitation Medicine Unit. SUBJECTS: A volunteer sample of 34 subjects participated in the study, 21 females and 13 males, with a mean age of 47.7 years (1 SD = 12.1) and 40.1 years (1 SD = 11.1), respectively. Subjects had chronic low back with or without leg pain of at least six months' duration. Subjects were recruited by medical practitioners and physiotherapists through the Rehabilitation Unit at the Essendon Campus of Royal Melbourne Hospital. MAIN OUTCOME MEASURES: Lower back range of motion measured with a long arm goniometer and a dual inclinometer, Waddell Physical Impairment Scale, Waddell Disability Index, Oswestry Disability Index. RESULTS: Both range of motion measurement methods demonstrated poor validity and do not bear any consistent relationship to the level of physical or functional impairment in subjects with chronic low back pain. CONCLUSIONS: There was no evidence for a relationship between low back range of motion and impairment, and thus it would appear illogical to evaluate impairment in chronic low back pain patients using a spinal range of motion model when aiming to measure or compensate disability.

Latex allergy in an orthognathic patient and implications for clinical management.

A 19-year-old girl with mild asthma had had 16 months of orthodontic treatment as part of the joint orthodontic/orthognathic approach to her 9.5 mm overjet. At the time of banding her second molars she developed latex protein allergy as a reaction to the operator's non-sterile powdered latex gloves. She also gave a history of allergy to other substances as well as of eczema. The patient was confirmed as allergic to latex protein by radioallergosorbent test (RAST) for IgE, requiring precautions be taken during further orthodontic procedures as well as during the subsequent orthognathic surgery for the underlying Class II skeletal pattern.

Reliability of the American Medical Association guides' model for measuring spinal range of motion. Its implication for whole-person impairment rating.

STUDY DESIGN: Repeated measures design for intra- and interrater reliability. OBJECTIVES: To determine the intra- and interrater reliability of the lumbar spine range of motion measured with a dual inclinometer, and the thoracolumbar spine range of motion measured with a long-arm goniometer, as recommended in the American Medical Association Guides. SUMMARY OF BACKGROUND DATA: The American Medical Association Guides (2nd and 4th editions) recommend using measurements of thoracolumbar and lumbar range of movement, respectively, to estimate the percentage of permanent impairment in patients with chronic low back pain. However, the reliability of this method of estimating impairment has not been determined. METHODS: In all, 34 subjects participated in the study, 21 women with a mean age of 40.1 years (SD, +/- 11.1) and 13 men with a mean age of 47.7 years (SD, +/- 12.1). Measures of thoracolumbar flexion, extension, lateral flexion, and rotation were obtained with a long-arm goniometer. Lumbar flexion, extension, and lateral flexion were measured with a dual inclinometer. Measurements were taken by two examiners on one occasion and by one examiner on two occasions approximately 1 week apart. RESULTS: The results showed poor intra- and interrater reliability for all measurements taken with both instruments. Measurement error expressed in degrees showed that measurements taken by different raters exhibited systematic as well as random differences. As a result, subjects measured by two different examiners on the same day, with either instrument, could give impairment ratings ranging between 0% and 18% of the whole person (excluding rotation), in which percentage impairment is calculated using the average range of motion and the average systematic and random error in degrees for the group for each movement (flexion, extension, and lateral flexion). CONCLUSIONS: The poor reliability of the American Medical Association Guides' spinal range of motion model can result in marked variation in the percentage of whole-body impairment. These findings have implications for compensation bodies in Australia and other countries that use the American Medical Association Guides' procedure to estimate impairment in chronic low back pain patients.

Diclazuril in the horse: its identification and detection and preliminary pharmacokinetics.

Diclazuril (4-chlorophenyl [2,6-dichloro-4-(4,5-dihydro-3H-3,5-dioxo-1,2,4-triazin-2-yl)pheny l] acetonitrile), is a benzeneacetonitrile antiprotozoal agent (Janssen Research Compound R 64433) marketed as Clinacox . Diclazuril may have clinical application in the treatment of Equine Protozoal Myeloencephalitis (EPM). To evaluate its bioavailability and preliminary pharmacokinetics in the horse we developed a sensitive quantitative high-pressure liquid chromatography (HPLC) method for diclazuril in equine biological fluids. MS/MS analysis of diclazuril in our HPLC solvent yielded mass spectral data consistent with the presence of diclazuril. After a single oral dose of diclazuril at 2.5 g/450 kg (as 500 g Clinacox), plasma samples from four horses showed good plasma concentrations of diclazuril which peaked at 1.077 +/- 0.174 microg/mL (mean +/- SEM) with an apparent plasma half-life of about 43 h. When this dose of Clinacox was administered daily for 21 days to two horses, mean steady state plasma concentrations of 7-9 microg/mL were attained. Steady-state levels in the CSF ranged between 100 and 250 ng/mL. There was no detectable parent diclazuril in the urine samples of dosed horses by HPLC or by routine postrace thin layer chromatography (TLC). These results show that diclazuril is absorbed after oral administration and attains steady-state concentrations in plasma and CSF. The steady state concentrations attained in CSF are more than sufficient to interfere with Sarcocystis neurona, whose proliferation is reportedly 95% inhibited by concentrations of diclazuril as low as 1 ng/mL. These results are therefore entirely consistent with and support the reported clinical efficacy of diclazuril in the treatment of clinical cases of EPM.

Acute and subacute changes in the ultrasound measurements of the calcaneus following intense exercise.

The amount of exercise necessary to cause bone structural change in humans is unknown. We examined whether a single bout of intense exercise in vivo leads to acute and subacute changes in the physical properties of bone as measured by ultrasound. It was hypothesized that structural changes such as accumulation of fatigue microdamage would result in a decrease in velocity of sound (VOS) and broadband ultrasound attenuation (BUA) across the calcaneus. We performed a prospective cohort study in 111 (97 M, 14 F) entrants of the 1996 Melbourne marathon (42.3 km) and 28 (10 M, 18 F) nonrunning controls. Runners had a mean (SD) age of 45.3 +/- 11.4 years (range 20-75), had completed 15.2 +/- 17.3 prior marathons (0-88), and had been running regularly for 14.2 +/- 9.2 years (0.25-50). An ultrasound densitometer (Cuba Clinical, McCue) was used to measure VOS and BUA across the right calcaneus. Runners were tested on three occasions: 1-3 days prior to, immediately after (<2 hours), and 5-6 days following the marathon. Seventy-three (66%) runners presented for all three measurements. Controls were tested on three occasions with the same time intervals as the runners. BUA values in the runners were significantly elevated by 5.0% immediately after the marathon but returned to baseline levels by the third test session (P = 0. 0001). Changes in BUA values in the controls were not significant and all were less than 0.7% (P = 0.88). Age was a significant independent predictor of the BUA change between test 1 and test 2 in the runners (beta = 0.2094; SE = 0.0917; P = 0.03). VOS measurements were not significantly different across the three testing sessions in both the runners (P = 0.07) and the controls (P = 0.33). Therefore, ultrasound measurements of BUA and VOS did not detect evidence of lasting structural change in the calcaneus following a marathon.

The effect of environmental factors on elastomeric chain and nickel titanium coil springs.

It is well known that elastomers exhibit viscoelasticity and as such have their mechanical properties modified by temperature. Nickel titanium archwires are also affected by temperature and have been modified with specific temperature related properties for clinical use. What is less well known is the effect that other environmental factors, such as food, might have on the force delivery properties of both elastomeric materials and nickel titanium coil springs used for space closure. For instance gross colour change in elastomeric chain is a common clinical finding in patients who consume spiced foods. The aim of this work was to determine the effect three common environmental factors namely, water, Coke, and turmeric solution have on elastomeric chain and nickel titanium coil springs. In addition, it was decided to re-examine the effect of temperature at 10, 22, and 37 degrees C on both these space closing materials. Unlike many previous investigations, the test specimens were held at a constant stretch throughout the test period, including during their transfer to the Instron Universal Testing machine for force measurement. Six force measurements were made over the first hour, then at 24 hours and 7 days. A control group of dry specimens, maintained at 22 degrees C, had additional measurements made weekly for a 4-week period. The results indicated that elastomeric chain was affected by all the test environments while nickel titanium springs were only affected by temperature.

Hip and ankle range of motion in elite classical ballet dancers and controls.

OBJECTIVE: To report range of motion at the hip and ankle in male and female ballet dancers compared with controls. DESIGN: Cross-sectional cohort study with convenience control sample. SETTING: National classical ballet school in Australia. PARTICIPANTS: Thirty-three female and 30 male full-time ballet students of mean (SD) age 16.9 (0.8) and 18.0 (1.4) years, respectively. Controls were 31 female and 16 male nondancing, normally active university students of average ages 18.8 +/- 0.6 and 18.8 +/- 0.9 years, respectively. MAIN OUTCOME MEASURES: Degrees of range of motion of left and right sides for the following four movements: standing plié in parallel-passive ankle dorsiflexion (DF), standing turnout in the balletic first position-lower limb external rotation (LLER), supine hip external rotation (ER), supine hip internal rotation (IR). Two additional ranges of motion were calculated. External rotation below the hip joint (BHER) was derived by subtracting hip ER from LLER, and total supine hip rotation (Hip IR + ER) was derived by summing hip ER and hip IR. MAIN RESULTS: On both left and right sides, dancers had greater LLER (p < 0.0001) and hip ER (p < 0.0001) but lesser hip IR than the controls (p < 0.0001). Female but not male dancers had greater total supine hip rotation (hip ER+IR) than controls (p < 0.05). There was no difference in either BHER or ankle DF between dancers and controls. Within dancers, females had greater range in both left and right hip IR, LLER, and hip IR + ER. There was no difference in hip ER. Regression analysis revealed that LLER related to hip ER in both males and females. CONCLUSIONS: Elite classical dance students had greater hip external rotation (both ER and LLER) and less hip internal rotation than controls but similar BHER and ankle DF. Since ER below the hip joint and ankle DF do not differ between dancers and controls, despite repeated training of these movements in ballet, there may be anatomical (bony/ligamentous) limitations to these movements.

The role of soft tissues in the aetiology of malocclusion.

It is not always easy to discover the aetiology of malocclusion: only in about 5% of cases is a cause clearly identifiable. In this article, the various genetic, environmental and physical factors that may contribute to malocclusion are discussed.

An investigation into the placement of force delivery systems and the initial forces applied by clinicians during space closure.

This in vitro investigation was designed to establish not only how clinicians apply forces for space closure when using the straight wire appliance and sliding mechanics, but also to quantify the initial force levels produced. A single typodont, with residual extraction space in each quadrant, was set up to simulate space closure using sliding mechanics. On two occasions, at least 2 months apart, 18 clinicians were asked to apply three force delivery systems to the typodont, in the manner in which they would apply it in a clinical situation. The three types of force delivery system investigated were elastomeric chain, an elastomeric module on a steel ligature, and a nickel-titanium closed coil spring. A choice of spaced or unspaced elastomeric chain produced by a single manufacturer was provided. The amount of stretch which was placed on each type of system was measured and, using an Instron Universal Testing Machine, the initial force which would be generated by each force delivery system was established. Clinicians were assessed to examine their consistency in the amount of stretch which each placed on the force delivery systems, their initial force application and their ability to apply equivalent forces with the different types of force delivery system. The clinicians were found to be consistent in their method of application of the force delivery systems and, therefore, their force application, as individuals, but there was a wide range of forces applied as a group. However, most clinicians applied very different forces when using different force delivery systems. When using the module on a ligature the greatest force was applied, whilst the nickel titanium coil springs provided the least force.

Adult orthodontics--a review.

The increased demand for orthodontic treatment by adults suggests a review of the literature might be timely. In this review we explore whether the increased in demand is real and matched by need. We also examine the reasons for treatment being sought and special considerations which are important during orthodontic treatment. Finally, we compare the orthodontic experience of adults and adolescents. We conclude that adults seeking treatment can be excellent patients with high motivation and co-operation. The limitations of orthodontic treatment must be explained at the beginning of treatment since adult expectations of orthodontics can be very high.