Minimum Detectable Intakes and Doses for Uranium Bioassays-Comparison between Alpha Spectrometry and ICP-MS.

ABSTRACT: Naturally occurring uranium complicates monitoring for occupational exposures. There are several retroactive methods that can be used to monitor for occupational exposures, with benefits and drawbacks to each. Analysis of uranium in urine by mass spectrometry and alpha spectrometry is compared, and methods of determining an occupational exposure are presented. The minimum detectable concentrations from each analysis and a method for intake determination based on the analytical results are compared for various solubility types and mixtures. Mass spectrometry with radiochemical separation was found to be the most sensitive analysis for detecting occupational exposures to anthropogenic mixtures based on minimum detectable doses calculated from the proposed method for intake determination.

Behaviorally-mediated trophic cascade attenuated by prey use of risky places at safe times.

The mere threat of predation may incite behavioral changes in prey that lead to community-wide impacts on productivity, biodiversity, and nutrient cycling. The paucity of experimental manipulations, however, has contributed to controversy over the strength of this pathway in wide-ranging vertebrate systems. We investigated whether simulated gray wolf (Canis lupus) presence can induce behaviorally-mediated trophic cascades, specifically, whether the 'fear' of wolf olfactory cues alone can change deer foraging behavior in ways that affect plants and soils. Wolves were recently removed from the Cedar Creek Ecosystem Science Reserve (Minnesota, USA), such that consumptively mediated predator effects were negligible. At 32 experimental plots, we crossed two nested treatments: wolf urine application and herbivore exclosures. We deployed camera traps to quantify how white-tailed deer (Odocoileus virginianus) adjusted their spatiotemporal habitat use, foraging, and vigilance in response to wolf cues and how these behavioral changes affected plant productivity, plant communities, and soil nutrients. Weekly applications of wolf urine significantly altered deer behavior, but deer responses did not cascade to affect plant or soil properties. Deer substantially reduced crepuscular activity at wolf-simulated sites compared to control locations. As wolves in this area predominantly hunted during mornings and evenings, this response potentially allows deer to maximize landscape use by accessing dangerous areas when temporal threat is low. Our experiment suggests that prey may be sensitive to 'dynamic' predation risk that is structured across both space and time and, consequentially, prey use of risky areas during safe times may attenuate behaviorally-mediated trophic cascades at the predator-prey interface.

Inequity in rehabilitation interventions after hip fracture: a systematic review.

OBJECTIVE: to determine the extent to which equity factors contributed to eligibility criteria of trials of rehabilitation interventions after hip fracture. We define equity factors as those that stratify healthcare opportunities and outcomes. DESIGN: systematic search of MEDLINE, Embase, CINHAL, PEDro, Open Grey, BASE and ClinicalTrials.gov for randomised controlled trials of rehabilitation interventions after hip fracture published between 1 January 2008 and 30 May 2018. Trials not published in English, secondary prevention or new models of service delivery (e.g. orthogeriatric care pathway) were excluded. Duplicate screening for eligibility, risk of bias (Cochrane Risk of Bias Tool) and data extraction (Cochrane's PROGRESS-Plus framework). RESULTS: twenty-three published, eight protocol, four registered ongoing randomised controlled trials (4,449 participants) were identified. A total of 69 equity factors contributed to eligibility criteria of the 35 trials. For more than 50% of trials, potential participants were excluded based on residency in a nursing home, cognitive impairment, mobility/functional impairment, minimum age and/or non-surgical candidacy. Where reported, this equated to the exclusion of 2,383 out of 8,736 (27.3%) potential participants based on equity factors. Residency in a nursing home and cognitive impairment were the main drivers of these exclusions. CONCLUSION: the generalisability of trial results to the underlying population of frail older adults is limited. Yet, this is the evidence base underpinning current service design. Future trials should include participants with cognitive impairment and those admitted from nursing homes. For those excluded, an evidence-informed reasoning for the exclusion should be explicitly stated. PROSPERO: CRD42018085930.

The KASH-containing isoform of Nesprin1 giant associates with ciliary rootlets of ependymal cells.

Biallelic nonsense mutations of SYNE1 underlie a variable array of cerebellar and non-cerebellar pathologies of unknown molecular etiology. SYNE1 encodes multiple isoforms of Nesprin1 that associate with the nuclear envelope, with large cerebellar synapses and with ciliary rootlets of photoreceptors. Using two novel mouse models, we determined the expression pattern of Nesprin1 isoforms in the cerebellum whose integrity and functions are invariably affected by SYNE1 mutations. We further show that a giant isoform of Nesprin1 associates with the ciliary rootlets of ependymal cells that line brain ventricles and establish that this giant ciliary isoform of Nesprin1 harbors a KASH domain. Whereas cerebellar phenotypes are not recapitulated in Nes1gSTOP/STOP mice, these mice display a significant increase of ventricular volume. Together, these data fuel novel hypotheses about the molecular pathogenesis of SYNE1 mutations and support that KASH proteins may localize beyond the nuclear envelope in vivo.

Parental beliefs about portion size, not children's own beliefs, predict child BMI.

BACKGROUND: Increases in portion size are thought by many to promote obesity in children. However, this relationship remains unclear. Here, we explore the extent to which a child's BMI is predicted both by parental beliefs about their child's ideal and maximum portion size and/or by the child's own beliefs. METHODS: Parent-child (5-11 years) dyads (N = 217) were recruited from a randomized controlled trial (n = 69) and an interactive science centre (n = 148). For a range of main meals, parents estimated their child's 'ideal' and 'maximum tolerated' portions. Children completed the same tasks. RESULTS: An association was found between parents' beliefs about their child's ideal (ß = .34, p < .001) and maximum tolerated (ß = .30, p < .001) portions, and their child's BMI. By contrast, children's self-reported ideal (ß = .02, p = .718) and maximum tolerated (ß = -.09, p = .214) portions did not predict their BMI. With increasing child BMI, parents' estimations aligned more closely with their child's own selected portions. CONCLUSIONS: Our findings suggest that when a parent selects a smaller portion for their child than their child self-selects, then the child is less likely to be obese. Therefore, public health measures to prevent obesity might include instructions to parents on appropriate portions for young children.

Capturing differences in dental training using a virtual reality simulator.

Virtual reality simulators are becoming increasingly popular in dental schools across the world. But to what extent do these systems reflect actual dental ability? Addressing this question of construct validity is a fundamental step that is necessary before these systems can be fully integrated into a dental school's curriculum. In this study, we examined the sensitivity of the Simodont (a haptic virtual reality dental simulator) to differences in dental training experience. Two hundred and eighty-nine participants, with 1 (n = 92), 3 (n = 79), 4 (n = 57) and 5 (n = 61) years of dental training, performed a series of tasks upon their first exposure to the simulator. We found statistically significant differences between novice (Year 1) and experienced dental trainees (operationalised as 3 or more years of training), but no differences between performance of experienced trainees with varying levels of experience. This work represents a crucial first step in understanding the value of haptic virtual reality simulators in dental education.

Strategies for Automated CryoEM Data Collection Using Direct Detectors.

The new generation of direct electron detectors has been a major contributor to the recent resolution revolution in cryo-electron microscopy. Optimal use of these new cameras using automated data collection software is critical for high-throughput near-atomic resolution cryo-electron microscopy research. We present an overview of the practical aspects of automated data collection in the context of this new generation of direct detectors, highlighting the differences, challenges, and opportunities the new detectors provide compared to the previous generation of data acquisition media.

Post-exercise hot water immersion induces heat acclimation and improves endurance exercise performance in the heat.

We examined whether daily hot water immersion (HWI) after exercise in temperate conditions induces heat acclimation and improves endurance performance in temperate and hot conditions. Seventeen non-heat-acclimatized males performed a 6-day intervention involving a daily treadmill run for 40 min at 65% V̇O2max in temperate conditions (18 °C) followed immediately by either HWI (N = 10; 40 °C) or thermoneutral (CON, N = 7; 34 °C) immersion for 40 min. Before and after the 6-day intervention, participants performed a treadmill run for 40 min at 65% V̇O2max followed by a 5-km treadmill time trial (TT) in temperate (18 °C, 40% humidity) and hot (33 °C, 40% humidity) conditions. HWI induced heat acclimation demonstrated by lower resting rectal temperature (Tre , mean, -0.27 °C, P < 0.01), and final Tre during submaximal exercise in 18 °C (-0.28 °C, P < 0.01) and 33 °C (-0.36 °C, P < 0.01). Skin temperature, Tre at sweating onset and RPE were lower during submaximal exercise in 18 °C and 33 °C after 6 days in HWI (P < 0.05). Physiological strain and thermal sensation were also lower during submaximal exercise in 33 °C after 6 days in HWI (P < 0.05). HWI improved TT performance in 33 °C (4.9%, P < 0.01) but not in 18 °C. Thermoregulatory measures and performance did not change in CON. Hot water immersion after exercise on 6 days presents a simple, practical, and effective heat acclimation strategy to improve endurance performance in the heat.

Does the continuation of warfarin change management outcomes in epistaxis patients?

OBJECTIVE: This study aimed to compare management, readmission rates and length of in-patient stay amongst warfarinised and non-warfarinised patients to ascertain future treatment protocols. METHODS: A 12-month retrospective review was conducted of ENT epistaxis admissions. Admission details such as length of in-patient stay, clotting profile and management plan were recorded. Comparisons of management and outcome for warfarinised and non-warfarinised patients were made using the Fisher's exact paired t-test. RESULTS: Of 176 epistaxis patients admitted, 31 per cent were warfarinised, 18 per cent were on another form of anticoagulation or antiplatelet therapy, and 51 per cent were not on any medication that might impose a bleeding risk. The international normalised ratio at admission was high in 13 per cent of warfarinised patients; the remaining patients had therapeutic or sub-therapeutic international normalised ratios and so warfarin was continued. The mean in-patient stay was similar for all cohorts; however, warfarinised patients had a higher readmission rate. CONCLUSION: Warfarinised epistaxis patients may be safely managed without stopping their anticoagulation therapy, provided their international normalised ratio is at therapeutic or sub-therapeutic levels. By continuing regular anticoagulation therapy, warfarinised patients may be discharged without delay.

Computerized Tool to Manage Dental Anxiety: A Randomized Clinical Trial.

Anxiety regarding dental and physical health is a common and potentially distressing problem, for both patients and health care providers. Anxiety has been identified as a barrier to regular dental visits and as an important target for enhancement of oral health-related quality of life. The study aimed to develop and evaluate a computerized cognitive-behavioral therapy dental anxiety intervention that could be easily implemented in dental health care settings. A cognitive-behavioral protocol based on psychoeducation, exposure to feared dental procedures, and cognitive restructuring was developed. A randomized controlled trial was conducted (N = 151) to test its efficacy. Consenting adult dental patients who met inclusion criteria (e.g., high dental anxiety) were randomized to 1 of 2 groups: immediate treatment (n = 74) or a wait-list control (n = 77). Analyses of covariance based on intention-to-treat analyses were used to compare the 2 groups on dental anxiety, fear, avoidance, and overall severity of dental phobia. Baseline scores on these outcomes were entered into the analyses as covariates. Groups were equivalent at baseline but differed at 1-mo follow-up. Both groups showed improvement in outcomes, but analyses of covariance demonstrated significant differences in dental anxiety, fear, avoidance, and overall severity of dental phobia in favor of immediate treatment at the follow-up assessment. Of the patients who met diagnostic criteria for phobia at baseline, fewer patients in the immediate treatment group continued to meet criteria for dental phobia at follow-up as compared with the wait-list group. A new computer-based tool seems to be efficacious in reducing dental anxiety and fear/avoidance of dental procedures. Examination of its effectiveness when administered in dental offices under less controlled conditions is warranted (ClinicalTrials.gov NCT02081365).

Stochastic Threshold Exponential (TE) Model for Hematopoietic Tissue Reconstitution Deficit after Radiation Damage.

Whole-body exposure to large radiation doses can cause severe loss of hematopoietic tissue cells and threaten life if the lost cells are not replaced in a timely manner through natural repopulation (a homeostatic mechanism). Repopulation to the baseline level N 0 is called reconstitution and a reconstitution deficit (repopulation shortfall) can occur in a dose-related and organ-specific manner. Scott et al. (2013) previously introduced a deterministic version of a threshold exponential (TE) model of tissue-reconstitution deficit at a given follow-up time that was applied to bone marrow and spleen cellularity (number of constituent cells) data obtained 6 weeks after whole-body gamma-ray exposure of female C.B-17 mice. In this paper a more realistic, stochastic version of the TE model is provided that allows radiation response to vary between different individuals. The Stochastic TE model is applied to post gamma-ray-exposure cellularity data previously reported and also to more limited X-ray cellularity data for whole-body irradiated female C.B-17 mice. Results indicate that the population average threshold for a tissue reconstitution deficit appears to be similar for bone marrow and spleen and for 320-kV-spectrum X-rays and Cs-137 gamma rays. This means that 320-kV spectrum X-rays could successfully be used in conducting such studies.

A Comparison of In Vivo Cellular Responses to Cs-137 Gamma Rays And 320-kV X Rays.

Research reported here relates to comparing the relative effectiveness of 320-kV X rays compared to Cs-137 gamma rays for two in vivo endpoints in C.B-17 mice after whole-body exposure: (1) cytotoxicity to bone marrow cells and splenocytes evaluated at 24-hours post exposure and (2) bone marrow and spleen reconstitution deficits (repopulation shortfalls) evaluated at 6 weeks post exposure. We show that cytotoxicity dose-response relationships for bone marrow cells and splenocytes are complex, involving negative curvature (decreasing slope as dose increases), presumably implicating a mixed cell population comprised of large numbers of hypersensitive, modestly radiosensitive, and resistant cells. The radiosensitive cells appear to respond with 50% being killed by a dose < 0.5 Gy. The X-ray relative biological effectiveness (RBE), relative to gamma rays, for destroying bone marrow cells in vivo is > 1, while for destroying splenocytes it is < 1. In contrast, dose-response relationships for reconstitution deficits in the bone marrow and spleen of C.B-17 mice at 6 weeks after radiation exposure were of the threshold type with gamma rays being more effective in causing reconstitution deficit.

Gas exchange patterns and water loss rates in the Table Mountain cockroach, Aptera fusca (Blattodea: Blaberidae).

The importance of metabolic rate and/or spiracle modulation for saving respiratory water is contentious. One major explanation for gas exchange pattern variation in terrestrial insects is to effect a respiratory water loss (RWL) saving. To test this, we measured the rates of CO2 and H2O release ( and , respectively) in a previously unstudied, mesic cockroach, Aptera fusca, and compared gas exchange and water loss parameters among the major gas exchange patterns (continuous, cyclic, discontinuous gas exchange) at a range of temperatures. Mean , and per unit did not differ among the gas exchange patterns at all temperatures (P>0.09). There was no significant association between temperature and gas exchange pattern type (P=0.63). Percentage of RWL (relative to total water loss) was typically low (9.79±1.84%) and did not differ significantly among gas exchange patterns at 15°C (P=0.26). The method of estimation had a large impact on the percentage of RWL, and of the three techniques investigated (traditional, regression and hyperoxic switch), the traditional method generally performed best. In many respects, A. fusca has typical gas exchange for what might be expected from other insects studied to date (e.g. , , RWL and cuticular water loss). However, we found for A. fusca that expressed as a function of metabolic rate was significantly higher than the expected consensus relationship for insects, suggesting it is under considerable pressure to save water. Despite this, we found no consistent evidence supporting the conclusion that transitions in pattern type yield reductions in RWL in this mesic cockroach.

Energy expenditure in rock/pop drumming.

Despite the vigorous nature of rock/pop drumming, there are no precise data on the energy expenditure of this activity. The aim of this study was to quantify the energy cost of rock/pop drumming. Fourteen male drummers (mean±SD; age 27±8 yrs.) completed an incremental drumming test to establish the relationship between energy expenditure and heart rate for this activity and a ramped cycle ergometer test to exhaustion as a criterion measure for peak values (oxygen uptake and heart rate). During live concert performance heart rate was continuously measured and used to estimate energy expenditure (from the energy expenditure vs. heart rate data derived from the drumming test). During concert performance, estimated energy expenditure (mean±SD) was 623±168 kcal.h⁻¹ (8.1±2.2 METs) during performances of 38.6±15.6 min, and drummers achieved a peak heart rate of 186±16 b.min⁻¹. During the drumming test participants attained 78.7±8.3% of the cycle ergometer peak oxygen uptake. Rock/pop drumming represents a relatively high-intensity form of physical activity and as such involves significant energy expenditure. Rock/pop drumming should be considered as a viable alternative to more traditional forms of physical activity.

What ethical difference does an apostrophe make? Balancing the interests of patients and dental professionals.

Dental professionals are obliged to put the interests of patients first. This is certainly laudable but it is unclear how far this duty extends. A further concern is whether it relates to the interests of a practitioner's own patients or to patients in general. The particular placement of an apostrophe in the General Dental Council's guidance is ambiguous. Dental professionals also have their own interests and might well ask if those interests should always be superseded. Every dental professional has a responsibility to put patient interests first as part of their professional registration; understanding this duty is therefore vital.

Biological microdosimetry based on radiation cytotoxicity data.

Researchers in the field of radiation microdosimetry have attempted to explain the relative biological effectiveness (RBE) of different ionising photon radiation sources on the basis of the singly stochastic, microdose metric lineal energy y, which only addresses physical stochasticity related to energy (ε) deposition via single events in the critical targets (cell nuclei assumed here). Biological stochasticity related to variable nuclei geometries and cell orientations (relative to the incoming radiation) is usually not addressed. Here a doubly stochastic microdose metric, the single-event hit size q (=ε/T), is introduced which allows the track length T to be stochastic. The new metric is used in a plausible model of metabolic-activity-based in vitro cytotoxicity of low-dose ionising photon radiation. The cytotoxicity model has parameters E{q} (average single-event hit size with q assumed to be exponentially distributed) and E{α}, which is the average value of the cellular response parameter α. E{α} is referred to as the biological signature and it is independent of q. Only E{q} is needed for determination of RBE. The model is used to obtain biological-microdosimetry-based q spectra for 320-kV X-rays and (137)Cs gamma rays and the related RBE for cytotoxicity. The spectra are similar to published lineal energy y spectra for 200-kV X-rays and (60)Co gamma rays for 1-µm biological targets.

The oxygen uptake kinetic response to moderate intensity exercise in overweight and non-overweight children.

OBJECTIVE: To compare the phase II oxygen uptake time constant (τV'O(2)) and V'O(2) mean response time (V'O(2)MRT) in overweight (OW) and non-OW (NO) children during moderate intensity exercise. DESIGN: Between subjects where participants completed a maximal ramp exercise test on an electromagnetically braked cycle ergometer to determine peak V'O(2) (V'O(2peak)) and gas exchange threshold (GET). Gas exchange was measured breath-by-breath using a mass spectrometer. On subsequent visits, 6 square-wave transitions (2 per day) from 0 W to 90% GET were completed. Individual phase II τV'O(2) and V'O(2)MRTs were estimated from time aligned average V'O(2) traces. SUBJECTS: Eleven OW (11.8±0.4 years) and 12 NO (11.9±0.4 years) children were recruited to the study. The OW group was significantly heavier (62.9±9.7 vs 39.4±5.8 kg, P<0.001), taller (1.58±0.05 vs 1.47±0.07 m, P<0.001) and had a higher body mass index (25.8±3.4 vs 18.3±1.8 kg m(-2), P<0.001). RESULTS: Both τV'O(2) (30.2±9.6 vs 22.8±7.1 s, P<0.05) and V'O(2)MRT (43.5±10.7 vs 36.3±5.3 s, P<0.05) were significantly slower in OW compared with NO children; absolute V'O(2peak) was higher in the OW compared with NO group (2.23±0.04 vs 1.74±0.04 l min(-1), P<0.05); mass relative V'O(2peak) was lower in OW compared with NO children (35.9±8.3 vs 43.8±6.2 ml kg(-1) min(-1), P<0.05); allometrically scaled V'O(2peak) was similar between OW and NO groups whether relative to body mass(0.67) (139.8±29.1 vs 147.2±23.9 ml kg(-67) min(-1)) or stature(3) (576.0±87.2 vs 544.9±84.9 ml m(-3) min(-1)) (P>0.05); absolute V'O(2) at GET was similar between OW and NO groups (0.94±0.24 vs 0.78±0.27 l min(-1), P>0.05); GET expressed as percentage of V'O(2peak) was similar between the groups (42.0±0.1 vs 44.8±0.1%, P>0.05). CONCLUSION: These findings demonstrate impairment in the factors determining V'O(2) kinetics in OW children at a relatively young age. Furthermore, assessment of cardiorespiratory fitness using peak exercise values is likely to be misleading and not useful when designing exercise programmes for OW children.

Outcomes of canalplasty for chronic obliterative otitis externa.

INTRODUCTION: Chronic obliterative otitis externa is a rare cause of conductive hearing loss, characterised by stenosis of the deep ear canal secondary to chronic inflammation. A multitude of canalplasty techniques have been described, with variable success. METHOD: Fourteen patients undergoing canalplasty performed by the senior author for refractory obliterative otitis externa, over an 8-year period, were included in the study. All underwent split-skin grafting of the denuded canal and meticulous post-operative aural care. Outcome measures included the Glasgow Benefit Inventory and pure tone audiology. RESULTS: At 3 months post-operatively, the four-tone average threshold had improved by a mean of 13.9 dB (95 per cent confidence interval -9.9 to 37.8 dB; t < 0.001) in the operated ear. The mean Glasgow Benefit Inventory score was 20 (95 per cent confidence interval -2.3 to 42.1). CONCLUSION: Significant improvements in both hearing and quality of life are achievable in patients with end-stage obliterative otitis externa treated surgically. Highly trained and competent aural care practitioners are a prerequisite for the success of the procedure, and a substantial number of patients must be prepared to submit to long-term follow-up care.

Genomic and functional analysis of Vibrio phage SIO-2 reveals novel insights into ecology and evolution of marine siphoviruses.

We report on a genomic and functional analysis of a novel marine siphovirus, the Vibrio phage SIO-2. This phage is lytic for related Vibrio species of great ecological interest including the broadly antagonistic bacterium Vibrio sp. SWAT3 as well as notable members of the Harveyi clade (V.harveyi ATTC BAA-1116 and V.campbellii ATCC 25920). Vibrio phage SIO-2 has a circularly permuted genome of 80598 bp, which displays unusual features. This genome is larger than that of most known siphoviruses and only 38 of the 116 predicted proteins had homologues in databases. Another divergence is manifest by the origin of core genes, most of which share robust similarities with unrelated viruses and bacteria spanning a wide range of phyla. These core genes are arranged in the same order as in most bacteriophages but they are unusually interspaced at two places with insertions of DNA comprising a high density of uncharacterized genes. The acquisition of these DNA inserts is associated with morphological variation of SIO-2 capsid, which assembles as a large (80 nm) shell with a novel T=12 symmetry. These atypical structural features confer on SIO-2 a remarkable stability to a variety of physical, chemical and environmental factors. Given this high level of functional and genomic novelty, SIO-2 emerges as a model of considerable interest in ecological and evolutionary studies.