Muscle coactivation during gait in children with and without cerebral palsy.

BACKGROUND: Children with Cerebral Palsy (CP) walk with an uncoordinated gait compared to Typically Developing (TD) children. This behavior may reflect greater muscle co-activation in the lower limb; however, findings are inconsistent, and the determinants of this construct are unclear. RESEARCH OBJECTIVES: (i) Compare lower-limb muscle co-activation during gait in children with, and without CP, and (ii) determine the extent to which muscle co-activation is influenced by electromyography normalization procedures and Gross Motor Function Classification System (GMFCS) class. METHODS: An electromyography system measured muscle activity in the rectus femoris, semitendinosus, gastrocnemius, and tibialis anterior muscles during walking in 46 children (19 CP, 27 TD). Muscle co-activation was calculated for the tibialis anterior-gastrocnemius (TA-G), rectus femoris-gastrocnemius (RF-G), and rectus femoris-semitendinosus (RF-S) pairings, both using root mean squared (RMS)-averaged and dynamically normalized data, during stance and swing. Mann-Whitney U and independent t-tests examined differences in muscle co-activation by group (CP vs. TD) and GMFCS class (CP only), while mean difference 95% bootstrapped confidence intervals compared electromyography normalization procedures. RESULTS: Using dynamically normalized data, the CP group had greater muscle co-activation for the TA-G and RF-G pairs during stance (p < 0.01). Using RMS-averaged data, the CP group had greater muscle co-activation for TA-G (stance and swing, p < 0.01), RF-G (stance, p < 0.05), and RF-S (swing, p < 0.01) pairings. Muscle co-activation calculated with dynamically normalized, compared to RMS-averaged data, were larger in the RF-S and RF-G (stance) pairs, but smaller during swing (RF-G). Children with CP classified as GMFCS II had greater muscle co-activation during stance in the TA-G pair (p < 0.05). SIGNIFICANCE: Greater muscle co-activation observed in children with CP during stance may reflect a less robust gait strategy. Although data normalization procedures influence muscle co-activation ratios, this behavior was observed independent of normalization technique.

The effect of uneven surfaces on inter-joint coordination during walking in children with cerebral palsy.

Clinical gait analysis on uneven surfaces contributes to the ecological assessment of gait deviations of children with spastic cerebral palsy (CP). Walking on uneven surfaces requires specific motor strategies, which can be assessed by lower-limb kinematic and inter-joint coordination analyses. This study aimed to assess and compare kinematics and inter-joint coordination between children with CP and their typically developing (TD) peers when walking on even and two levels of uneven surfaces (medium and high). A total of 17 children with CP and 17 TD children (11.5 ± 3.5 and 10.4 ± 4.5 years old, respectively) were asked to complete 6-8 gait trials on a 4-m walkway of each surface (n = 3) in randomized blocks while fit with retro-reflective markers on their lower-limbs. Children with CP showed proximal gait adaptations (i.e., hip and knee) on uneven surfaces. Compared with the TD group, the CP group showed decreased hip extension during late stance (49-63%, d = 0.549, p < 0.001), and a more in-phase knee-hip coordination strategy during swing phase (75-84% of gait cycle, d = 1.035, p = 0.029 and 92-100%, d = 1.091, p = 0.030) when walking on an uneven (high), compared to even surface. This study provides a better understanding of kinematic strategies employed by children with spastic CP when facing typical daily life gait challenges. Further studies are needed to evaluate the benefits of integrating uneven surfaces in rehabilitation care.

Large-scale optical characterization of solid-state quantum emitters.

Solid-state quantum emitters have emerged as a leading quantum memory for quantum networking applications. However, standard optical characterization techniques are neither efficient nor repeatable at scale. Here we introduce and demonstrate spectroscopic techniques that enable large-scale, automated characterization of colour centres. We first demonstrate the ability to track colour centres by registering them to a fabricated machine-readable global coordinate system, enabling a systematic comparison of the same colour centre sites over many experiments. We then implement resonant photoluminescence excitation in a widefield cryogenic microscope to parallelize resonant spectroscopy, achieving two orders of magnitude speed-up over confocal microscopy. Finally, we demonstrate automated chip-scale characterization of colour centres and devices at room temperature, imaging thousands of microscope fields of view. These tools will enable the accelerated identification of useful quantum emitters at chip scale, enabling advances in scaling up colour centre platforms for quantum information applications, materials science and device design and characterization.

Muscle co-contraction and co-activation in cerebral palsy during gait: A scoping review.

BACKGROUND: Cerebral palsy (CP) results from an injury to a developing brain. Muscle activation patterns during walking are disrupted in individuals with CP. Indeed, excessive muscle co-contraction or co-activation (MCo/MCa) is one of the characteristics of pathological gait. Although some researchers have studied MCo/MCa in individuals with CP during gait, inconsistent results limit our understanding of this literature. Increased knowledge of MCo/MCa patterns in individuals with CP may help the development of improved gait management approaches. RESEARCH QUESTION: This review aims to summarize MCo/MCa patterns while walking in individuals with CP across the existing literature and compare them with their healthy peers. METHODS: This study follows the Joanna Briggs Institute (JBI) guidelines and the recommendations presented in PRISMA Extension for Scoping Reviews (PRISMA-ScR). The recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for scoping Reviews statement were respected. The following databases were searched: MEDLINE (Ovid), EMBASE (Ovid), CINAHL Plus with Full Text (Ebsco), SPORTDiscus with Full Text (Ebsco), and Web of Science. RESULTS: Among 2545 identified studies, 21 studies remained after screening. In total, 337 participants with CP and 249 healthy participants were included. Both MCo and MCa terminologies are used for describing simultaneous muscle activation; however, when it is measured by electromyography (EMG), MCa terminology should be preferred to facilitate interpretation. A wide range of MCo/MCa patterns has been found across studies using different methodologies (e.g., gait protocol, computation methods). Finally, most of the included studies confirm that MCo/MCa is increased in individuals with CP during walking compared to controls. SIGNIFICANCE: This review identified missing concepts and common limitations in the literature which could be addressed in future research such as the association between MCo/MCa and gait deviations, and the most appropriate MCo/MCa computation method.

Multi-faceted intervention to improve management of antibiotics for children presenting to primary care with acute cough and respiratory tract infection (CHICO): efficient cluster randomised controlled trial.

OBJECTIVE: To assess whether an easy-to-use multifaceted intervention for children presenting to primary care with respiratory tract infections would reduce antibiotic dispensing, without increasing hospital admissions for respiratory tract infection. DESIGN: Two arm randomised controlled trial clustered by general practice, using routine outcome data, with qualitative and economic evaluations. SETTING: English primary care practices using the EMIS electronic medical record system. PARTICIPANTS: Children aged 0-9 years presenting with respiratory tract infection at 294 general practices, before and during the covid-19 pandemic. INTERVENTION: Elicitation of parental concerns during consultation; a clinician focused prognostic algorithm to identify children at very low, normal, or elevated 30 day risk of hospital admission accompanied by antibiotic prescribing guidance; and a leaflet for carers including safety netting advice. MAIN OUTCOME MEASURES: Rate of dispensed amoxicillin and macrolide antibiotics (superiority comparison) and hospital admissions for respiratory tract infection (non-inferiority comparison) for children aged 0-9 years over 12 months (same age practice list size as denominator). RESULTS: Of 310 practices needed, 294 (95%) were randomised (144 intervention and 150 controls) representing 5% of all registered 0-9 year olds in England. Of these, 12 (4%) subsequently withdrew (six owing to the pandemic). Median intervention use per practice was 70 (by a median of 9 clinicians). No evidence was found that antibiotic dispensing differed between intervention practices (155 (95% confidence interval 138 to 174) items/year/1000 children) and control practices (157 (140 to 176) items/year/1000 children) (rate ratio 1.011, 95% confidence interval 0.992 to 1.029; P=0.25). Pre-specified subgroup analyses suggested reduced dispensing in intervention practices with fewer prescribing nurses, in single site (compared with multisite) practices, and in practices located in areas of lower socioeconomic deprivation, which may warrant future investigation. Pre-specified sensitivity analysis suggested reduced dispensing among older children in the intervention arm (P=0.03). A post hoc sensitivity analysis suggested less dispensing in intervention practices before the pandemic (rate ratio 0.967, 0.946 to 0.989; P=0.003). The rate of hospital admission for respiratory tract infections in the intervention practices (13 (95% confidence interval 10 to 18) admissions/1000 children) was non-inferior compared with control practices (15 (12 to 20) admissions/1000 children) (rate ratio 0.952, 0.905 to 1.003). CONCLUSIONS: This multifaceted antibiotic stewardship intervention for children with respiratory tract infections did not reduce overall antibiotic dispensing or increase respiratory tract infection related hospital admissions. Evidence suggested that in some subgroups and situations (for example, under non-pandemic conditions) the intervention slightly reduced prescribing rates but not in a clinically relevant way. TRIAL REGISTRATION: ISRCTN11405239ISRCTN registry ISRCTN11405239.

Delocalized photonic deep learning on the internet's edge.

Advanced machine learning models are currently impossible to run on edge devices such as smart sensors and unmanned aerial vehicles owing to constraints on power, processing, and memory. We introduce an approach to machine learning inference based on delocalized analog processing across networks. In this approach, named Netcast, cloud-based "smart transceivers" stream weight data to edge devices, enabling ultraefficient photonic inference. We demonstrate image recognition at ultralow optical energy of 40 attojoules per multiply (<1 photon per multiply) at 98.8% (93%) classification accuracy. We reproduce this performance in a Boston-area field trial over 86 kilometers of deployed optical fiber, wavelength multiplexed over 3 terahertz of optical bandwidth. Netcast allows milliwatt-class edge devices with minimal memory and processing to compute at teraFLOPS rates reserved for high-power (>100 watts) cloud computers.

Lower-limb joint-coordination and coordination variability during gait in children with cerebral palsy.

BACKGROUND: Children with cerebral palsy present with poor motor control, altering their ability to perform tasks such as walking. Continuous relative phase analysis is a popular method to quantify motor control impairments via inter-joint coordination and coordination variability; however, it has not been explored in children with cerebral palsy. METHODS: 45 children with cerebral palsy and 45 typically developing children walked while fit with retroreflective markers. Continuous relative phase analysis for knee-hip and ankle-knee joint pairs quantified inter-joint coordination and coordination variability. The Gait Profile Score estimated gait pathology. Group differences were assessed with unpaired t-tests for coordination amplitude and variability (knee-hip, ankle-knee) across gait events. For the cerebral palsy group, correlations assessed the relation between the gait profile score and coordination metrics. FINDINGS: The cerebral palsy group showed more in-phase patterns for knee-hip coupling compared to the typically developing group (initial contact, loading response, mid-stance, terminal swing) (p ≤ 0.03). The cerebral palsy group showed lower knee-hip coordination variability (mid-stance, mid-swing) (p ≤ 0.037) and lower ankle-knee coordination variability (initial contact, loading response, terminal swing) (p < 0.001). The gait profile score correlated weakly to moderately (r = [0.323-0.472]), and negatively with the knee-hip inter-joint coordination (initial contact, loading response, mid-stance, terminal swing) (p ≤ 0.042). INTERPRETATION: Children with cerebral palsy showed a more in-phase gait strategy during challenging transitional gait cycle phases (beginning and end) and less flexible and adaptable motor behaviors. Moreover, the correlation between in-phase joint patterns and increased gait deviations (gait profile score) reinforces the relevance of coordination analysis to assess motor control impairment.

Gait adaptations of individuals with cerebral palsy on irregular surfaces: A scoping review.

BACKGROUND: Individuals with cerebral palsy (CP) have a reduced ability to perform motor tasks such as walking. During daily walking, they are confronted with environmental constraints such as irregular surfaces (e.g., relief and uneven surfaces) which may require adaptations to maintain stability and avoid falls. Laboratory gait assessments are conventionally conducted under ideal conditions (e.g., regular and even surfaces) and may overlook subtle problems which may only present in challenging walking environments. Increased knowledge of adaptations to successfully navigate irregular surfaces may contribute to a better understanding of everyday walking barriers. RESEARCH QUESTION: This scoping review aims to describe gait adaptations to irregular surfaces in individuals with CP and contrast adaptations with those of healthy individuals. METHODS: This review followed the 6-stage Joanna Briggs Institute methodology and respected the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews statement. The MEDLINE, EMBASE, CINAHL, SPORTDiscus, and Web of Science databases were searched on March 2021. RESULTS: The research strategy identified 1616 studies published between 2014 and 2020, of which 10 were included after abstract and full-text screening. This review reported on 152 individuals with CP (diplegia: n = 117, hemiplegia: n = 35) and 159 healthy individuals. The included studies focused on spatial-temporal, kinematic, kinetic, and muscle activity parameters over relief, inclined, and staircase surfaces. 7/10 studies were conducted in laboratories, often using surfaces that are not representative of the real-world. The results suggest that for individuals with CP, adaptations on irregular surfaces differ from flat surface walking and across CP subtype. Moreover, individuals with CP present with typical and pathology-specific adaptations to irregular surfaces compared to healthy individuals. SIGNIFICANCE: This review highlights the clinical and research interest of focusing future studies on more ecologically valid data collection approaches and provides important recommendations to overcome research gaps in the existing literature.

The impact of outdoor walking surfaces on lower-limb coordination and variability during gait in healthy adults.

BACKGROUND: Inter-joint coordination and variability during gait provide insight into control and adaptability of the neuromuscular system. To date, coordination research has been restricted to laboratory settings, and it is unclear how these findings translate to real-world, outdoor walking environments. RESEARCH QUESTION: Compared to flat walking, to what extent do outdoor surfaces impact lower-limb inter-joint coordination and variability during gait, in healthy adults? METHODS: Data from inertial measurement units placed on the lower-back, thigh, and shank were extracted from thirty healthy young adults (15 females, 23.5 ± 4.2 years) during outdoor walking on flat (paved sidewalk); irregular (cobblestone, grass); sloped (slope-up, slope-down); and banked (banked-right, banked-left) surfaces. Sagittal joint angles for the right knee and hip were computed and partitioned by gait phase (stance and swing). Continuous Relative Phase analysis determined inter-joint coordination and variability for the knee-hip joint pair using Mean Absolute Relative Phase (MARP) and Deviation Phase (DP), respectively. One-way repeated measures ANOVAs tested surface effects. Post-hoc Bonferroni adjusted surface comparisons were assessed. RESULTS: Significant knee-hip surface effects were seen during all gait phases for MARP (p < 0.001) and DP (p ≤ 0.001). Compared to flat walking, grass prompted more in-phase coordination (smaller MARP) during stance and swing phase (p ≤ 0.003). Slope-up caused more in-phase coordination during stance (p < 0.001), while slope-down caused more out-of-phase coordination during stance and swing (p ≤ 0.003), compared to the flat surface. Sloped surfaces prompted more variable (larger DP) knee-hip coordination (p ≤ 0.001), compared to flat walking during stance and swing phase. SIGNIFICANCE: Compared to flat walking, changes in knee-hip coordination and variability were greatest on slope-up/slope-down surfaces. This could reflect greater changes in lower-limb kinematics on sloped surfaces and/or a neuromuscular response to the demands of a more challenging task.

Lower-limb coordination and variability during gait: The effects of age and walking surface.

BACKGROUND: Falls among community-dwelling older adults are often triggered by uneven walkways. Joint coordination and its variability change with age and may place older adults at risk of falling. It is unclear how irregular surfaces impact lower-limb joint coordination and if such changes are exacerbated by aging. RESEARCH QUESTION: To what extent do lower-limb inter-joint coordination and its variability, over flat and uneven brick walkways, differ between older and young healthy adults? METHODS: A motion-capture system collected kinematic data from walking trials on flat and uneven walkways in seventeen older (72.0 ±â€¯4.2 years) and eighteen younger (27.0 ±â€¯4.7 years) healthy adults. Continuous relative phase analyses were performed for the Knee-Hip and Ankle-Knee joint pairs. Mean Absolute Relative Phase (MARP) quantified coordination amplitude. Deviation Phase (DP) quantified coordinative variability. Two-way mixed ANOVA's tested for effects of age, surface, and age × surface interactions. RESULTS: Uneven surfaces prompted more in-phase MARP inter-joint coordination in adults during most gait phases (p ≤ 0.024). Age × surface interactions were observed during initial contact (Ankle-Knee: p = 0.021, Knee-Hip: p = 0.001) and loading response (Knee-Hip: p = 0.017), with post-hoc analyses showing coordination accentuated in older adults. Uneven surfaces induced higher DP in Knee-Hip (p = 0.017) and Ankle-Knee joint coupling (p < 0.001) during gait, largely independent of age. An age × surface interaction was observed during mid-swing (p = 0.050), with post-hoc analysis revealing increased variability in older adults. SIGNIFICANCE: More in-phase and variable lower-limb gait behavior was observed on uneven walkways. These differences were accentuated in older adults during early stance phase (more tightly coordinated) and mid-swing (more variable). This may reflect a cautious gait strategy on challenging walkways to maintain stability and help prevent falls.

Ursodeoxycholic acid in intrahepatic cholestasis of pregnancy: a secondary analysis of the PITCHES trial.

OBJECTIVE: To evaluate whether a particular group of women with intrahepatic cholestasis of pregnancy (ICP), based on their presenting characteristics, would benefit from treatment with ursodeoxycholic acid (UDCA). DESIGN: Secondary analysis of the PITCHES trial (ISRCTN91918806). SETTING: United Kingdom. POPULATION OR SAMPLE: 527 women with ICP. METHODS: Subgroup analyses were performed to determine whether baseline bile acid concentrations or baseline itch scores moderated a woman's response to treatment with UDCA. MAIN OUTCOME MEASURES: Bile acid concentration and itch score. RESULTS: In women with baseline bile acid concentrations less than 40 µmol/l, treatment with UDCA resulted in increased post-randomisation bile acid concentrations (geometric mean ratio 1.19, 95% CI 1.00-1.41, P = 0.048). A test of interaction showed no significance (P = 0.647). A small, clinically insignificant difference was seen in itch response in women with a high baseline itch score (-6.0 mm, 95% CI -11.80 to -0.21, P = 0.042), with a test of interaction not showing significance (P = 0.640). Further subgroup analyses showed no significance. Across all women there was a weak relationship between bile acid concentrations and itch severity. CONCLUSIONS: There was no subgroup of women with ICP in whom a beneficial effect of treatment with UDCA on bile acid concentration or itch score could be identified. This confirms that its routine use in women with this condition for improvement of bile acid concentration or itch score should be reconsidered. TWEETABLE ABSTRACT: PITCHES: No group of women with ICP has been found in whom UDCA reduces bile acid concentrations or pruritus.

Guideline for the management of hip fractures 2020: Guideline by the Association of Anaesthetists.

We convened a multidisciplinary Working Party on behalf of the Association of Anaesthetists to update the 2011 guidance on the peri-operative management of people with hip fracture. Importantly, these guidelines describe the core aims and principles of peri-operative management, recommending greater standardisation of anaesthetic practice as a component of multidisciplinary care. Although much of the 2011 guidance remains applicable to contemporary practice, new evidence and consensus inform the additional recommendations made in this document. Specific changes to the 2011 guidance relate to analgesia, medicolegal practice, risk assessment, bone cement implantation syndrome and regional review networks. Areas of controversy remain, and we discuss these in further detail, relating to the mode of anaesthesia, surgical delay, blood management and transfusion thresholds, echocardiography, anticoagulant and antiplatelet management and postoperative discharge destination. Finally, these guidelines provide links to supplemental online material that can be used at readers' institutions, key references and UK national guidance about the peri-operative care of people with hip and periprosthetic fractures during the COVID-19 pandemic.

Assessing Biogeography of Coffee Rust Risk in Brazil as Affected by the El Niño Southern Oscillation.

The El Niño Southern Oscillation (ENSO) is an oceanic-atmospheric phenomenon influencing worldwide weather and climate. Its occurrence is determined by the sea surface temperature (SST) anomaly of the 3.4 Niño region in the Pacific Ocean (5°N-5°S, 120°-170°W). El Niño (EN), Neutral (NT), and La Niña (LN) are the three possible phases of ENSO, respectively, for warm, normal, and cold SST anomaly. As in other regions around the world, weather in Brazil is influenced by ENSO phases. The country is the major coffee producer in the world, and production is strongly influenced by weather conditions, which affect plant yield, harvest quality, and interactions with pests and diseases. Coffee leaf rust (CLR), caused by the fungus Hemileia vastatrix, is a major cause of coffee yield and quality losses in Brazil, and requires fungicide spray applications every season. Because CLR is highly influenced by weather conditions, it is possible to use weather variables to simulate its progress during the cropping cycle. Therefore, the aims of this study were to estimate CLR infection rate based on a validated empirical model, which has daily minimum air temperature and relative humidity as inputs, and to assess the extent of ENSO influence on the annual risk of this disease at 45 sites in Brazil. Cumulative infection rates (CIR) were estimated daily from October to June of each growing season and location, based on the prevailing ENSO phase. Differences between the extreme phases (EN-LN) were assessed by the Two-One-Sided-Tests (TOST) method. Analysis of data from eight sites, located mainly in Paraná State, provided evidence of CIR differences between EN and LN phases (G1). Evidence of no difference of CIR between EN and LN was found in 18 sites (G2), whereas 19 sites showed no evidence of differences (G3) due to relatively large variation of CIR within the same ENSO phase. The G1 sites are located mostly in Southern Brazil, where ENSO exerts a well-defined influence on rainfall regime. In contrast, the G2 sites are mainly in Minas Gerais State, which is characterized as a transition region for ENSO influence on rainfall. The G3 sites are located between the northern region of Minas Gerais State and southern region of Bahia State, which is characterized by a subhumid climate that is usually very dry during winter, and where rainfall can vary up to 300% from one year to another, influencing relative humidity and resulting in a high CIR variability. Therefore, ENSO had a well-defined influence on CIR only in Paraná State, a region with minor importance for coffee production in Brazil. No ENSO influence was found in more northerly zones where the majority of Brazilian coffee is produced. This is the first evidence of ENSO-linked regional impact on the risk of coffee rust.

Cohort antler size signals environmental stress in a moderate climate.

Research in northern latitudes confirms that climate teleconnections exert important influences on ungulate fitness, but studies from regions with milder climates are lacking. We explored the influence of the Pacific Decadal Oscillation (PDO), Northern Atlantic Oscillation (NAO), and El Niño-Southern Oscillation (ENSO) on male, 2.5-year-old white-tailed deer (Odocoileus virginianus) antler and body mass in Mississippi, USA, a region with mild winters and warm, humid summers. Explanatory variables were seasonal averages of each climate index extending back to 3 years prior to account for possible maternal and lag effects. Seasonal climate indices from the period of gestation and the first year of life were correlated with deer morphometrics. Reduced antler mass was largely correlated (R2 = 0.52) with PDO values indicating dry conditions during parturition and neonatal development and NAO values indicating warmer than normal winters during gestation and the first year of life. Body mass was less correlated (R2 = 0.16) to climate indices, responding negatively to warmer winter weather during the first winter of life. Climate may promote variable fitness among cohorts through long-term effects on male competition for dominance and breeding access. Because broad-scale climate indices simplify complex weather systems, they may benefit management at larger scales. Although this study compared climate with morphological variables, it is likely that demographic characteristics can likewise be modeled using climate indices. As climate change in this region is projected to include greater variability in summer precipitation, we may see concomitantly greater variability in fitness among cohorts of white-tailed deer.

A microbiome analysis of equine peripheral dental caries using next generation sequencing.

BACKGROUND: Although, peripheral caries (PC) affects almost half of UK horses, no comprehensive microbiological study has been performed on this disorder. As a high proportion of oral bacteria cannot be conventionally cultured, molecular microbiological techniques such as Next Generation Sequencing are required to examine the complex oral bacteria community. OBJECTIVES: To identify the microbiota involved in equine PC, including comparing microbiota at the more commonly and severely affected three caudal cheek teeth with the less commonly affected three rostral cheek teeth. STUDY DESIGN AND METHODS: Equine dental plaque samples were collected from the palatal aspects of cheek teeth of 63 horses. DNA was isolated and amplified using PCR, targeting the V4 region of the 16S rRNA gene and Next Generation Sequencing of these gene amplicons was performed. The acquired data were processed and analysed using Mothur and R. RESULTS: Streptococcus species was the genus most commonly associated with equine PC, whereas Gemella species was the genus most associated with the control group. In a further analysis where the rostral and caudal cheek teeth were compared with each other and with the control group. Veillonella species was the most commonly associated genus with PC of the rostral cheek teeth, Streptococcus species was the most associated genus with the caudal cheek teeth, and Corynebacterium with the control group. MAIN LIMITATIONS: Some bacteria can have multiple heterogeneous copies of the 16S rRNA gene, which can affect the estimation of their relative abundance. CONCLUSIONS: Similar to caries studies in other species, acidogenic and aciduric microorganisms including Streptococcus species were found to be associated with equine peripheral caries.

A histological and ultrastructural study of equine peripheral caries.

BACKGROUND: Peripheral caries (PC) has recently been shown to affect over half of UK and Australian horses. OBJECTIVES: To examine affected cheek teeth histologically and ultrastructurally, to assess the possible route(s) of carious infection into the dental tissues and to further describe the pathological changes in affected teeth. STUDY DESIGN: Descriptive pathological study. METHODS: Four control and 16 cheek teeth with different grades of PC were examined grossly, histologically and by electron microscopy. RESULTS: Cariogenic bacteria from plaque entered peripheral cementum perpendicular to the sides of teeth alongside Sharpey's fibres or vascular channels or more horizontally alongside exposed intrinsic fibres and cemental growth lines. Subsequent intra-cemental bacterial spread created different patterns of caries including vertical and horizontal flake-like patterns; deep, large flask-shaped or smaller superficial ellipsoid-shaped lytic lesions. Cemental caries progressed to affect enamel, dentine and even pulp. Gross examination underestimated the degree of caries observed on histological evaluation. MAIN LIMITATIONS: No dental histories were available; all teeth were examined on a single occasion. CONCLUSION: Equine PC causes different patterns of cemental lesions that appear dependent on the route of cariogenic bacterial invasion. Progression of caries can lead to pulpitis and tooth loss. Gross examination can underestimate the true extent of caries.

Radiation protection value to the operator from augmented reality smart glasses in interventional fluoroscopy procedures using phantoms.

INTRODUCTION: Smart glasses can be adapted to display radiographic images to allow clinician's gaze not to be directionally fixed or predetermined by computer monitor location. This study presents an analysis of eye lens dose during interventional fluoroscopy guided procedures, comparing fixed monitor positions against the use of smart glasses. METHODS: Using a head phantom (simulating the clinician), thermoluminescent dosimeters and lead shielded glasses, the dose to the eye was measured for different head 'rotations and tilts' for: gaze directed towards the main scattering source (patient/primary beam) to represent potential gaze direction if smart glasses are used; gaze directed to a range of potential computer monitor positions. An anthropomorphic pelvis phantom was utilised to simulate the patient. Accumulated dose rates (µGy s-1) from five 10-second exposures at 75 kV 25.2 mAs were recorded. RESULTS: An average DAP reading of 758.84 cGy cm2 was measured during each 10 second exposure. Whilst wearing lead shielded glasses a 6.10 - fold reduction in dose rate to the lens is possible (p < 0.05). Influence of the direction of gaze by the clinician demonstrated a wide range of dose rate reduction from 3.13% (p = 0.16) to 143.69% (p < 0.05) when the clinician's gaze was towards the main scattering source. Increased dose rate to the clinician's eyes was received despite wearing lead shielded glasses, as the angle of gaze moved 45° and 90° from 0°. CONCLUSION: If the clinician's gaze is directed towards the main scattering source a potential exists for reducing eye lens dose compared with fixed location computer monitors. Introduction of lead lined smart glasses into interventional radiology may lead to improvements in patient care, reducing the need for the clinician to look away from the patient to observe a radiographic image.

Machine learning algorithms can classify outdoor terrain types during running using accelerometry data.

BACKGROUND: Running is a popular physical activity that benefits health; however, running surface characteristics may influence loading impact and injury risk. Machine learning algorithms could automatically identify running surface from wearable motion sensors to quantify running exposures, and perhaps loading and injury risk for a runner. RESEARCH QUESTION: (1) How accurately can machine learning algorithms identify surface type from three-dimensional accelerometer sensors? (2) Does the sensor count (single or two-sensor setup) affect model accuracy? METHODS: Twenty-nine healthy adults (23.3 ±â€¯3.6 years, 1.8 ±â€¯0.1 m, and 63.6 ±â€¯8.5 kg) participated in this study. Participants ran on three different surfaces (concrete, synthetic, woodchip) while fit with two three-dimensional accelerometers (lower-back and right tibia). Summary features (n = 208) were extracted from the accelerometer signals. Feature-based Gradient Boosting (GB) and signal-based deep learning Convolutional Neural Network (CNN) models were developed. Models were trained on 90% of the data and tested on the remaining 10%. The process was repeated five times, with data randomly shuffled between train-test splits, to quantify model performance variability. RESULTS: All models and configurations achieved greater than 90% average accuracy. The highest performing models were the two-sensor GB and tibia-sensor CNN (average accuracy of 97.0 ±â€¯0.7 and 96.1 ±â€¯2.6%, respectively). SIGNIFICANCE: Machine learning algorithms trained on running data from a single- or dual-sensor accelerometer setup can accurately distinguish between surfaces types. Automatic identification of surfaces encountered during running activities could help runners and coaches better monitor training load, improve performance, and reduce injury rates.

Processing transcutaneous electromyography measurements of respiratory muscles, a review of analysis techniques.

Transcutaneous electromyography (tc-EMG) has been used to measure the electrical activity of respiratory muscles during inspiration in various studies. Processing the raw tc-EMG signal of these inspiratory muscles has shown to be difficult as baseline noise, cardiac interference, cross-talk and motion artefacts can influence the signal quality. In this review we will discuss the most important sources of signal noise in tc-EMG of respiratory muscles and the various techniques described to suppress or reduce this signal noise. Furthermore, we will elaborate on the options available to develop or improve an algorithm that can be used to guide the approach for analysis of tc-EMG signals of inspiratory muscles in future research.