Large Deformation Diffeomorphic Metric Mapping And Fast-Multipole Boundary Element Method Provide New Insights For Binaural Acoustics

This paper describes how Large Deformation Diffeomorphic Metric Mapping (LDDMM) can be coupled with a Fast Multipole (FM) Boundary Element Method (BEM) to investigate the relationship between morphological changes in the head, torso, and outer ears and their acoustic filtering (described by Head Related Transfer Functions, HRTFs). The LDDMM technique provides the ability to study and implement morphological changes in ear, head and torso shapes. The FM-BEM technique provides numerical simulations of the acoustic properties of an individual's head, torso, and outer ears. This paper describes the first application of LDDMM to the study of the relationship between a listener's morphology and a listener's HRTFs. To demonstrate some of the new capabilities provided by the coupling of these powerful tools, we examine the classical question of what it means to ``listen through another individual's outer ears.'' This work utilizes the data provided by the Sydney York Morphological and Acoustic Recordings of Ears (SYMARE) database.Comment: Submitted as a conference paper to IEEE ICASSP 201

Holography of 3d Flat Cosmological Horizons

We provide a first derivation of the Bekenstein-Hawking entropy of 3d flat cosmological horizons in terms of the counting of states in a dual field theory. These horizons appear in the shifted-boost orbifold of R^{1,2}, the flat limit of non-extremal rotating BTZ black holes. These 3d geometries carry non-zero charges under the asymptotic symmetry algebra of R^{1,2}, the 3d Bondi-Metzner-Sachs (BMS3) algebra. The dual theory has the symmetries of the 2d Galilean Conformal Algebra, a contraction of two copies of the Virasoro algebra, which is isomorphic to BMS3. We study flat holography as a limit of AdS3/CFT2 to semi-classically compute the density of states in the dual, exactly reproducing the bulk entropy in the limit of large charges. Our flat horizons, remnants of the BTZ inner horizons also satisfy a first law of thermodynamics. We comment on how the dual theory reproduces the bulk first law and how cosmological bulk excitations are matched with boundary quantum numbers.Comment: 5 pages; v2: Typos corrected, references update

Determination of Fentanyl in Canine Plasma using HPLC-MS Detection

A simple, easy, and accurate high-performance liquid chromatographic method for the determination of fentanyl concentrations in plasma samples has been developed and validated. Following a liquid extraction with acetonitrile, samples were separated by reversed-phase high-performance liquid chromatography (HPLC) on an XBridge C18 column (2.1 x 50 mm, 3.5μm) and detected by mass spectroscopy. The mobile phase was a mixture of water with 0.1% formic acid, and acetonitrile with 0.1% formic acid (90:10), with a flow rate of 0.6 ml/min. The procedure produced a linear curve over the concentration range of 0.1-25 ng/ml for fentanyl in canine plasma with a LOQ of 0.1 ng/ml. Intra- and inter-assay variability ranged from 2.6%-8.2% and the average recovery for fentanyl was 100%

Kernal principal component analysis of the ear morphology

This paper describes features in the ear shape that change across a population of ears and explores the corresponding changes in ear acoustics. The statistical analysis conducted over the space of ear shapes uses a kernel principal component analysis (KPCA). Further, it utilizes the framework of large deformation diffeomorphic metric mapping and the vector space that is constructed over the space of initial momentums, which describes the diffeomorphic transformations from the reference template ear shape. The population of ear shapes examined by the KPCA are 124 left and right ear shapes from the SYMARE database that were rigidly aligned to the template (population average) ear. In the work presented here we show the morphological variations captured by the first two kernel principal components, and also show the acoustic transfer functions of the ears which are computed using fast multipole boundary element method simulations

A novel spatial feature for the identification of motor tasks using high-density electromyography

Estimation of neuromuscular intention using electromyography (EMG) and pattern recognition is still an open problem. One of the reasons is that the pattern-recognition approach is greatly influenced by temporal changes in electromyograms caused by the variations in the conductivity of the skin and/or electrodes, or physiological changes such as muscle fatigue. This paper proposes novel features for task identification extracted from the high-density electromyographic signal (HD-EMG) by applying the mean shift channel selection algorithm evaluated using a simple and fast classifier-linear discriminant analysis. HD-EMG was recorded from eight subjects during four upper-limb isometric motor tasks (flexion/extension, supination/pronation of the forearm) at three different levels of effort. Task and effort level identification showed very high classification rates in all cases. This new feature performed remarkably well particularly in the identification at very low effort levels. This could be a step towards the natural control in everyday applications where a subject could use low levels of effort to achieve motor tasks. Furthermore, it ensures reliable identification even in the presence of myoelectric fatigue and showed robustness to temporal changes in EMG, which could make it suitable in long-term applications

A novel spatial feature for the identification of motor tasks using high-density electromyography

Estimation of neuromuscular intention using electromyography (EMG) and pattern recognition is still an open problem. One of the reasons is that the pattern-recognition approach is greatly influenced by temporal changes in electromyograms caused by the variations in the conductivity of the skin and/or electrodes, or physiological changes such as muscle fatigue. This paper proposes novel features for task identification extracted from the high-density electromyographic signal (HD-EMG) by applying the mean shift channel selection algorithm evaluated using a simple and fast classifier-linear discriminant analysis. HD-EMG was recorded from eight subjects during four upper-limb isometric motor tasks (flexion/extension, supination/pronation of the forearm) at three different levels of effort. Task and effort level identification showed very high classification rates in all cases. This new feature performed remarkably well particularly in the identification at very low effort levels. This could be a step towards the natural control in everyday applications where a subject could use low levels of effort to achieve motor tasks. Furthermore, it ensures reliable identification even in the presence of myoelectric fatigue and showed robustness to temporal changes in EMG, which could make it suitable in long-term applications.Peer ReviewedPostprint (published version

Modulatory effect of protein and carotene dietary levels on pig gut microbiota

In this study we investigated the impact of dietary protein and carotene levels on microbial functions and composition during the last month of purebred fattening Duroc pigs. Fecal microbiota was characterized using 16S ribosomal RNA sequencing at two points of live, 165 (T1) and 195 (T2) days. From 70 to 165 days of age, 32 pigs were divided into two groups fed either a standard-protein (SP) or a low-protein (LP) diet. In the last month (165-195 days), all pigs received a LP diet, either carotene- enriched (CE) or not (NC). Significant differences were observed between T1 and T2 at Amplicon Sequences Variants (ASVs), phylum and genus levels. In T1 group, Prevotella, Faecalibacterium and Treponema were the genera most influenced by dietary protein, together with predicted functions related with the degradation of protein. In contrast, the CE diet did not impact the microbiome diversity, although 160 ASVs were differentially abundant between CE and NC groups at T2. Weak stability of enterotype clusters across time-points was observed as consequence of medium-term dietary interventions. Our results suggest that during the last month of fattening, dietary protein have a stronger effect than carotenes on the modulation of the compositional and functional structure of the pig microbiota.This study supported by the Spanish Ministry of Economy and Competitiveness and the European Union Regional Development Funds (AGL2015-65846-R). Y. Ramayo-Caldas was funded by the European Union H2020 Research and Innovation programme under Marie Skłodowska-Curie grant (P-Sphere) agreement No. 6655919. ES is a recipient of a PhD fellowship from the University of Lleida. RG is a recipient of a postdoctoral fellowship from the UdL-Impuls program. We acknowledge the staff at Selección Batallé for their cooperation

A Multidisciplinary Workplace Intervention for Chronic Low Back Pain among Nursing Assistants in Iran

Study DesignInterventional research with a 6-month follow-up period.PurposeWe aimed to establish the effectiveness of a multidisciplinary workplace intervention on reduction of work-related low back pain (WRLBP), using ergonomic posture training coupled with an educational program based on social cognitive theory.Overview of LiteratureWRLBP is a major occupational problem among healthcare workers, who are often required to lift heavy loads. Patient handling is a particular requirement of nurse aides, and has been reported as the main cause of chronic WRLBP.MethodsWe included 125 nursing assistants from two hospitals affiliated to Qom University of Medical Sciences from May to December 2015. There was an intervention hospital with a number of 63 nursing assistants who received four multidisciplinary educational sessions for 2 hours each plus ergonomic posture training over two days and a control hospital with a number of 62 nursing assistants who didn't receive educational intervention about low back pain. The outcomes of interest were reductions in WRLBP intensity and disability from baseline to the follow up at 6 months, which were measured using a visual analog scale and the Quebec Disability Scale. Descriptive and analytical statistics were used to analyze the data.ResultsThe comparison tests showed significant change from baseline in reduction of WRLBP intensity following the multidisciplinary program, with scores of 5.01±1.97 to 3.42±2.53 after 6 months on the visual analog scale in the intervention group (p<0.001) and no significant change in control groups. There was no significant difference in the disability scores between the two groups (p=0.07).ConclusionsWe showed that our multidisciplinary intervention could reduce the intensity of WRLBP among nurse aides, making them suitable for implementation in programs to improve WRLBP among nursing assistants working in hospitals

A Multidisciplinary Work-Related Low Back Pain Predictor Questionnaire: Psychometric Evaluation of Iranian Patient-Care Workers

Study DesignPsychometric evaluation design.PurposePsychometric evaluation of a multidisciplinary work-related low back pain predictor questionnaire (MWRLBPPQ) of Iranians patient-care workers based on the social cognitive theory.Overview of LiteratureHealthcare is one of the professions in which work-related musculoskeletal disorders are prevalent. The chronic low back pain experienced by patient caregivers can negatively impact their professional performance, and patient handling in a hospital is the main cause of low back pain in this population.MethodsThis was a cross-sectional study carried out in Qom, Iran from July 2014 to November 2014. A MWRLBPPQ based on nine concepts of the social cognitive theory and existing literature regarding chronic low back pain was developed. Ten patient-care workers first completed the questionnaire as a pilot test, allowing the ambiguities of the instrument to be resolved. Exploratory factor analysis was used to confirm construct validity. This questionnaire was distributed among 452 patient-care workers in hospitals located in different geographically areas in Qom, Iran. Cronbach's Alpha was calculated to assess reliability.ResultsIn all, 452 caregivers of patients with mean age of 37.71 (standard deviation=8.3) years participated in the study. An exploratory factor analysis loaded seven concepts of self-efficacy, knowledge, outcome perception, self-control, emotional coping, and self-efficacy in overcoming impediments and challenges in the environment. All concepts were jointly accounted for 50.08% of variance of behavior change. The Cronbach's alpha coefficient showed favorable internal consistency (alpha=0.83), and test-retest of the scale with 2-week intervals indicated an appropriate stability for the MWRLBPPQ.ConclusionsThe MWRLBPPQ is a reliable and valid theory-based instrument that can be used to predict factors influencing work-related low back pain among workers who lift and transfer patients in hospitals