Weight Shift Research Articles

PSV-6 Assessment of lameness in gilts and barrows using gait score, force-plate, hoof hardness and hoof lesions

Abstract Lameness in gilts and sows has an economic impact on pig production and is a major welfare concern. The objective of the present project was to evaluate and quantify lameness in pigs. The following methods were compared to visual gait scoring: force-plate, hoof hardness and hoof lesions. Eight barrows and seven gilts (114 ± 15 kg) were selected using visual gait scoring (0-4, 4 most severe). From this group there were 4-0’s, 4-1’s, 5-2’s, and 2-3’s. Factorial analyses, (site: front vs rear) and lameness score (0-3) and their interaction was used to evaluate effect of treatment. Consistent with published literature, rear legs were more affected by lameness than front legs (73% rear, 27% front). Only two categories for hoof lesions (white line lesion and heel erosion) were prevalent in this population. White line lesion severity increased with increasing lameness score and differed between site (P < 0.05). In contrast with literature, more white line lesions were prevalent in front vs rear. Hoof hardness was scored at 5 locations on the bottom of the hoof. At the toe tip only, there was a trend (P = 0.052) for hoof hardness to decrease with increasing lameness score, but no effect of site (P = 0.39) or interaction. Among force-plate measurements, there was a significant effect of lameness (P < 0.05) for maximum force, range (95th percentile-5th percentile), standard deviation of force, amplitude of weight-bearing (average of all positive peaks), amplitude of weight-removing (average of all negative peaks), but no significant effect observed for average force, weight shift (# of peaks/min) or contralateral ratio. On average, more weight was applied to front vs rear [30.4 vs 19.6%; (P < 0.05)]. Although further validation is warranted, these results indicate that these objective measures of lameness were sensitive enough to detect differences between lame vs non-lame pigs.

Optimizing ankle foot orthosis stiffness substantially improves energy cost compared to usual orthotic care in persons with calf muscle weakness

Postural stability depends on the integration of the multisensory system to produce motor outputs. When visual and somatosensory input is reliable, this reduces reliance on the vestibular system. Despite this, vestibular loss can still cause severe postural dysfunction. Training one or more of the three sensory systems through vestibular habituation and adaptation can alter sensory weighting and change postural behavior.The purpose of this study was to assess sensory reweighting of postural control processing after combined vestibular activation with voluntary weight shift training in healthy adults.Thirty-three healthy individuals (18–35 y.o.) were randomly assigned to one of three groups: No training (control), visual feedback weight shift training (WST) coupled with an active horizontal headshake (HS) activity to elicit a vestibular perturbation, or the same WST without HS (NoHS). Training was performed 2x/day, every other day (M, W, F), totaling six sessions. Pre- and post- assessments on the Sensory Organization Test (SOT) were performed. Separate between- and within- repeated measures ANOVAs were used to analyze the six SOT equilibrium scores, composite scores, sensory ratios and center of pressure (COP) variables by comparing baseline to post-training. Alpha level was set at p < .05.There was a significant group x session x condition change (p = .012) in the COP multiscale entropy (MSE) velocity sway in the HS group during SOT conditions 5 and 6. Similarly, COP medio-lateral standard deviation sway (ML Std) showed group x session x visual condition (p = .028), due to HS in condition 6 relative to other two groups.Postural training can alter sensory organization after a visual feedback-vestibular activation training protocol, suggesting a possible sensory reweighting through vestibular adaptation and/or habituation.Translating these findings into a vestibular-impaired population can stimulate the design of a rehabilitation balance protocol.

Hyperbolic forms admit reversible weighted shift determinantal representation

Lentzos and Pasley recently showed that a weakly circular symmetric invariant hyperbolic ternary form admits a determinantal representation through a cyclic weighted shift matrix. In this paper, we improve the representing matrix by employing a cyclic weighted shift with reversible weights.

Vestibular training promotes adaptation of multisensory integration in postural control

BackgroundPostural stability depends on the integration of the multisensory system to produce motor outputs. When visual and somatosensory input is reliable, this reduces reliance on the vestibular system. Despite this, vestibular loss can still cause severe postural dysfunction. Training one or more of the three sensory systems through vestibular habituation and adaptation can alter sensory weighting and change postural behavior. AimThe purpose of this study was to assess sensory reweighting of postural control processing after combined vestibular activation with voluntary weight shift training in healthy adults. MethodsThirty-three healthy individuals (18–35 y.o.) were randomly assigned to one of three groups: No training (control), visual feedback weight shift training (WST) coupled with an active horizontal headshake (HS) activity to elicit a vestibular perturbation, or the same WST without HS (NoHS). Training was performed 2x/day, every other day (M, W, F), totaling six sessions. Pre- and post- assessments on the Sensory Organization Test (SOT) were performed. Separate between- and within- repeated measures ANOVAs were used to analyze the six SOT equilibrium scores, composite scores, sensory ratios and center of pressure (COP) variables by comparing baseline to post-training. Alpha level was set at p < .05. ResultsThere was a significant group x session x condition change (p = .012) in the COP multiscale entropy (MSE) velocity sway in the HS group during SOT conditions 5 and 6. Similarly, COP medio-lateral standard deviation sway (ML Std) showed group x session x visual condition (p = .028), due to HS in condition 6 relative to other two groups. ConclusionPostural training can alter sensory organization after a visual feedback-vestibular activation training protocol, suggesting a possible sensory reweighting through vestibular adaptation and/or habituation. SignificanceTranslating these findings into a vestibular-impaired population can stimulate the design of a rehabilitation balance protocol.

골프 아이언 샷 동작의 복합적 고찰

The purpose of this study was to examine the biomechanical factors during the golf iron swing in major phases and to provide insight into the efficient swing movements for golf professionals.BR Four male collegiate golfers performed swings with a driver while foot pressure was measured. As for changes in the distribution of plantar pressure during iron shot motions, In the iron shot motion, the body weight was evenly distributed to both feet or a little more weight was placed on the left foot during the address, the weight was shifted to the right foot as the backswing began. The right foot maximally supported the weight at the top of the backswing and the weight was shifted to the left foot as the downswing began so that all the weight is supported by the left foot at the moment of impact until the finish.BR As for the transverse shift of the center point of plantar pressure, although there were differences among the subjects, the center point of plantar pressure shifted to the inside of the left foot during the address and to the outside of the right foot at the top of backswing. It moved to the outside of the left foot and the inside of the right foot during the impact and to the outside of the left foot and the inside of the right foot during the finish. It shifted to the ball of the left and the ball of the right foot during impact and to the ball of the left and the ball of the right foot during the finish. The results as such are judged to be attributable to the motions intended to use the forces resulting from weight shifts and ground reaction force.

집중체중 이동훈련이 뇌성마비 아동의 체간조절 능력에 미치는 영향 : 사례연구

집중체중 이동훈련이 뇌성마비 아동의 체간조절 능력에 미치는 영향 : 사례연구

Bilateral Weight Distribution Asymmetry in the Functional Movement Screen Deep Squat

The functional movement screen (FMS) deep squat (DS) is used to identify movement deficiencies and potentially predict injury. While evidence does not support the predictive validity of FMS scores, useful information can still be obtained. Weight shifts are often observed in the FMS DS, but current literature lacks information about asymmetrical weight distribution. PURPOSE: To determine the amount of weight distribution asymmetry in physically active young adults during the FMS DS. METHODS: Nineteen physically active participants (11 F, 8 M, 20.2 ± 1.0 yo) were recruited and granted informed consent. Participants performed three trials of the FMS DS with feet flat (FF) followed by three trials with elevated heels (EH) elevated on a 2x6 board. Trials were completed on two embedded force plates (1200Hz). Vertical ground reaction force (vGRF) data were used to determine asymmetry in bilateral weight distribution. Six reflective markers placed bilaterally on the greater trochanter, lateral femoral epicondyle and lateral malleolus were tracked with a 10-camera motion analysis system (120Hz). A Matlab script processed the data and computed knee flexion angle and vGRF asymmetry at squat initiation and full squat. Paired samples t-tests with a significance level of 0.05 were used. RESULTS: A significant increase (p<0.01) in knee flexion occurred in the EH squat condition (Left 105.9±20.2o, Right 105.8±20.5o) compared to FF (Left 100.8±22.5o, Right 101.0±23.1o). On average, participants experienced >5% asymmetry (0% being perfectly symmetric) for the starting position and full squat position during both FF and EH. There were no significant differences in weight distribution symmetry in the starting position (p=0.31) between squat conditions. The EH condition did not significantly change weight distribution symmetry (p=0.69) in the full squat position. Within squat condition, there was no significant differences between weight distribution symmetry from the starting position to the full squat position (FF: p=0.76, EH: p=0.43). CONCLUSION: Bilateral weight distribution asymmetry was present in the FMS DS both with flat and elevated heels in physically active participants. Coaches and trainers should consider implementing training programs to optimize biomechanical function during the FMS DS.

Optimizing Dance Interventions To Improve Motor Function In People With Parkinson’S Disease And Older Adults

Dance comprises a broad range of techniques and styles, which have been utilized in classes specifically designed for individuals with Parkinson’s disease (PD) and healthy older adults. Previous studies have shown that a series of dance sessions can improve balance, posture, and mobility for people diagnosed with PD and healthy older adults. However, these studies have not analyze the linkage between repetitive movement types and persistent changes in motor skills. In order to begin understanding the causative factors of repetitive movement types that result in improved motor skill performance, the functional relationship between movement features and observed performance improvements needs to be examined. PURPOSE: To identify dance movement patterns resulting in the greatest improvement in tests of gait, balance and upper extremity function using partnered and non-partnered dance to music in PD and healthy older adults. We hypothesize that scripted variation in movement will promote improvements in motor performance. METHODS: Participants in structured group dance classes were recruited for this study. Performance measures of upper and lower extremity were collected before and after each dance class. Motion capture, video and live observations were used to examine movement patterns. RESULTS: Individuals with PD had slower baseline performance in the 9 hole peg test (9HPT) than healthy older adults in both left (p=0.026, 33.5 s vs 24.9 s) and right hand (p=0.008, 31.2 s vs 26.5 s). There was also a significant improvement in the 9HPT for the left hand after the dance classes in the individuals with PD (p=0.035, 3.44 s). Factors that led to observed improvements in mobility and movement execution included: repetition of foundational weight shifts in a separate preparatory exercise, engagement of the spine and arms in counterbalancing movement in the legs, incorporating flexion at the knee into the dance stride, and partnering with a moderately-skilled dancer. Increased amplitude and ease of stride and greater lift in the feet in locomotion were also documented. CONCLUSIONS: These preliminary results suggest that repetitive shifts in balance and movement during dance with music can lead to upper extremity motor performance and increased amplitude of movement in the lower extremity in individuals with PD.

Effects of induced weight shift in the hind limbs on claw loads in dairy cows

The modern dairy industry is plagued by a high prevalence of claw horn lesions in cows, which cause lameness, affect well-being, limit milk production, and are responsible for premature removal of cows from the herd. The lateral hind claws are primarily affected, and this has been linked to a relatively higher load being exerted on the lateral claws when cows shift weight from one hind limb to the other. The vertical ground reaction forces and mean and maximum pressures under the claws were measured in 40 nonlame dairy cows before and during a shift in weight from one hind limb to the other, which was accomplished by applying pressure manually to one side of the pelvis. During square standing on firm ground, about two-thirds of the entire hind limb load was exerted on the 2 lateral claws, and the remaining one-third was exerted on the medial claws combined. At the moment of maximum weight shift, the lateral claw of the loaded limb bore almost two-thirds of the entire load of both hind limbs, with the heel zone bearing almost half of the load of both hind limbs. Subsequently, the load of the lateral claw of the contralateral hind limb decreased, as did the load of both medial claws. Thus, the weight redistribution had occurred predominantly between the lateral hind claws. The high load exerted on a lateral hind claw during weight shift and at maximum weight shift is assumed to play a role in the pathogenesis of claw horn lesions, particularly when accentuated by a softened claw horn and hard flooring.

Observing spin fractionalization in the Kitaev spin liquid via temperature evolution of indirect resonant inelastic x-ray scattering

Motivated by the ongoing effort to search for high-resolution signatures of quantum spin liquids, we investigate the temperature dependence of the indirect resonant inelastic x-ray scattering (RIXS) response for the Kitaev honeycomb model. We find that, as a result of spin fractionalization, the RIXS response changes qualitatively at two well-separated temperature scales, $T_L$ and $T_H$, which correspond to the characteristic energies of the two kinds of fractionalized excitations, $\mathbb{Z}_2$ gauge fluxes and Majorana fermions, respectively. While thermally excited $\mathbb{Z}_2$ gauge fluxes at temperature $T_L$ lead to a general broadening and softening of the response, the thermal proliferation of Majorana fermions at temperature $T_H \sim 10 \, T_L$ results in a significant shift of the spectral weight, both in terms of energy and momentum. Due to its exclusively indirect nature, the RIXS process we consider gives rise to a universal magnetic response and, from an experimental perspective, it directly corresponds to the $K$-edge of Ru$^{3+}$ in the Kitaev candidate material $\alpha$-RuCl$_3$.

The unrolled quantum group inside Lusztig’s quantum group of divided powers

In this letter we prove that the unrolled small quantum group, appearing in quantum topology, is a Hopf subalgebra of Lusztig’s quantum group of divided powers. We do so by writing down non-obvious primitive elements with the correct adjoint action. As application, we explain how this gives a realization of the unrolled quantum group as operators on a conformal field theory and match some calculations on this side. In particular, our results explain a prominent weight shift that appears in Feigin and Tipunin (Logarithmic CFTs connected with simple Lie algebras, preprint, 2010. arXiv:1002.5047 ). Our result extends to other Nichols algebras of diagonal type, including super-Lie algebras.

Investigation of UV and hygrothermal stress on back side of rack-mounted photovoltaic modules

When discussing the reliability of backsheet of PV modules, it is important to accurately determine the amount of stress it receives. In this study, the UV irradiation dosage on the back side of a rack-mounted module, which has been estimated from multiplication of the UV irradiation dosage on the front side and the UV albedo, was actually measured. It was found that the measured value was 1.4 kW h/m2/y, which was almost 1/3 of the estimated value of 4.2 kW h/m2/y. The environmental stress on the back side of the PV module was also investigated by comparing changes in the molecular weight distribution of transparent poly(ethylene terephthalate) films subjected to outdoor exposure or indoor acceleration test. It is shown that UV and hygrothermal stress can be separated by analysis of the molecular weight distribution peak height and shift so that the extent of UV dose in fielded modules can be estimated. It was found that the stress on the back side of the PV module, exposed for 5.5 years using asphalt with 6% UV albedo as the flooring material, was close to that of 8 kW h/m2 after a UV irradiation test, a subsequent 6 h pressure cooker test, or a subsequent 200 h damp heat test. Acceleration tests that reproduce stress itself rather than deterioration phenomena should be developed, and for that, it is important to measure the amount of stress in various cases with reference to this measurement and separation method of stress.

A biomechanical study of gait initiation in Down syndrome

BackgroundGait Initiation (GI) is a functional task that challenges the balance control requiring weight shift and a transition from standing to walking. Individuals with Down Syndrome (DS) walk with low velocity, prolonged stance and shorter steps beside an increased support base. However, no studies performed GI analysis on this population. The aim of this study is to quantitatively characterize the GI task in subjects with DS compared with a typically developed control group.MethodsSeventeen individuals with DS (17 to 40 years) and 19 healthy subjects (17 to 40 years) were enrolled in the study. Data were acquired using an optoelectronic motion capture system and force plates in order to measure the displacement and velocity of Center of Mass (CoM) and the trajectory of Center Of Pressure (CoP). All participants were asked to stand barefoot on the first force platform and received a verbal cue to begin walking for 6 gait initiation trials (three starting with each foot). The CoP duration, velocity, length and excursion were calculated during the anticipatory postural adjustments phases (APAs) and the locomotor (LOC) phase. For the analysis of the CoM, its displacements in antero-posterior (AP) and medio-lateral (ML) during the APAs and LOC phases. Statistical analysis was conducted to compare the two groups.ResultsRegarding CoP measures, when compared to control group, individuals with DS presented higher durations, lower velocities, longer lengths during the second APA and total phases, and shorter lengths during the first APA and LOC phases. The group with DS also presented longer CoP excursion during the second APA, whereas a shorter excursion was present during the first APA and LOC phases. The AP excursion in CoM is reduced in the participants with DS.ConclusionsOur results could be useful in the rehabilitation of individuals with DS as they suggest to reinforce exercise programs to improve balance in AP and ML directions, which is demonstrated to be impaired in these subjects.

A Novel Method of Analysis for Prolonged-Standing Data: Accounting for Joint and Muscle Discomfort

OCCUPATIONAL APPLICATIONS Prolonged standing, often required in healthcare, factory, and retail jobs, is associated with adverse health effects. In the present study, we introduce a novel method for analyzing prolonged-standing data, which accounts for time-dependent strain characteristics of both cartilage and muscle tissue to identify two different types of weight distribution change events. Compared to existing methods for analyzing this type of data, our proposed method provides more information about the amplitude and temporal quality of the movements occurring. If a worker were to stand on a surface that measures postural sway during a typical work day, this analysis method could identify the types of movements an individual makes, and help infer sources of discomfort. By understanding the movement strategy utilized, the most appropriate work environment adaptations can be put into place to decrease discomfort. These environmental adaptations may have downstream effects on worker satisfaction and days on disability.TECHNICAL ABSTRACT Background: The typical American worker spends about two-thirds of their work day standing. Prolonged standing has been found to be associated with acute and chronic adverse health outcomes. There is considerable variability among existing methods of analysis for prolonged-standing data, and therefore difficulty interpreting and comparing results across studies. Purpose: The purpose of this study is to develop a bodyweight transfer analysis method that incorporates factors of both time and amplitude of loading. This method was then applied to actual prolonged-standing data, to understand how the results of this method are impacted by time spent standing, and how the results relate to previously-reported methods of analysis for weight shifting data. Methods: Seven subjects (six male, one female) stood with each foot on one of two force plates for 6 h with a 5-min seated rest break between hours. Our new method identified two different types of events: fidgets and weight shifts. Center-of-pressure data were analyzed with the proposed method and three existing methods of analysis. Results: Subjects utilized different quantities of fidgets and weight shifts over the course of the trials. Existing methods of analysis identified a wide range in number of events, with some methods consistently identifying more events than others. These existing methods significantly differed from the proposed method. Fidgets, weight shifts, and fidgets + weight shifts, as identified using the proposed method, had significant interactions with time, while only one of the existing methods showed a significant time interaction. Conclusions: The conclusions drawn from analysis of prolonged standing center-of-pressure data can differ significantly depending on the method of analysis used. The method proposed here accounts for the different sources of discomfort and the tissue characteristics of these sources. Future work should explore the relationships between physiologic parameters and fidgets and weight shifts, so that appropriate clinical interventions can be identified.

Do changes in feature selection parameters influence the classification of knee rehabilitation exercises when using body worn accelerometer data?

Purpose: Exercise prescription plays a fundamental role in the treatment of knee pathologies such as knee osteoarthritis, where over 90,000 total knee replacement patients receive regular post-surgery physiotherapy each year in the UK. Physiotherapists rely on home-based exercise prescription yet have limited knowledge of patient engagement at home and find it difficult to objectively monitor patient progress, attribute functional improvement (or lack of) to adherence/non-adherence and prescribe personalised interventions. The research vision is to facilitate unobtrusive sensor driven home monitoring/feedback of knee rehabilitation exercises. As a first step, this study sought to fine tune a machine learning algorithm to classify between different knee exercises and understand the impact of different feature selection parameters on classification performance. Methods: 8 volunteers (4 healthy, 4 with self-reported history of knee pain/pathology but not receiving treatment) performed 15 repetitions of 4 knee rehabilitation exercises (sit to stand (STS), knee flexion (KFL), knee extension (KEX) and weight shifting (WSH)) whilst wearing lower limb Xsens inertial sensors sampling at 60 Hz. A total of 85 features were extracted per exercise repetition from tri-axial accelerometer data provided by sensors placed on the foot, shank, thigh and pelvis. These were defined as the 90th percentile spectral edge frequency ((SEF) in X,Y,Z axis) and signal mean, max min, variance, skewness, and kurtosis (all in the X,Y,Z axis) per sensor in addition to repetition length. Participants were split into training and testing datasets using a Leave-One-Group-Out cross validation (cv) where a participant with multiple repetitions represented a group. Within each of the 8 cv-folds, features were scaled, a univariate feature selection method was implemented to reduce the feature set to top ranking features and a linear support vector machine (SVM) classifier was performed to determine how well 4 different knee rehabilitation exercises could be distinguished from each other. This process was repeated using 3 different score function parameters (Mutual Information Classification (MIC), F-value Classification (F-Class) and Chi2) with the number of features being selected ranging from 1 - 10 to determine the optimal score function and number of features whilst optimising classification performance. The F1 score (weighted harmonic mean of precision and recall with a best score of 1) was computed within each cv-fold as an average F1 score across each of the exercises classes and then combined across cv-folds as a median and 1st - 3rd interquartile range. Results: Feature selection methods using the MIC and the F-Class score functions consistently outperformed that using the Chi2 (Figure 1). The MIC approach was chosen as the optimal feature selection method as the F-Class algorithm was marginally outperformed using fewer features with the optimal number of features (ie. fewest whilst retaining classifier performance) being 3. All 8 cv-folds using this method selected Z-axis acceleration 90th percentile SEF of the foot and shank sensors whilst the third feature varied slightly between cv-folds (mean Z-axis acceleration of the foot sensor (n=3/8 cv-folds); Y-axis mean acceleration of the thigh sensor (n=2/8 cv-folds), Z-axis acceleration variance of the foot (n=1/8 cv-folds) or shank (n=1/8 cv-folds) sensors and Z-axis mean acceleration of the shank sensor (n=1/8 cv-folds). Inspection of the individual F1-scores for each exercise using the optimal feature selection method revealed a reduced ability to classify KEX and KFL in comparison to STS and WSH exercises (Figure 2). Conclusions: Changing parameter settings within a univariate feature selection algorithm that identifies top ranking features was found to alter the performance of a linear SVM seeking to classify between 4 knee rehabilitation exercises. This finding confirms the impact that incorrect feature selection parameter settings may have on classification performance. From the parameters and feature selection methods considered, the combination of an MIC score function and the selection of the top 3 features appear optimal for this dataset. Whilst the 3 features selected appeared to consistently classify STS and WSH exercises well, this was not the case for KEX and KFL exercises with both varying considerably between the cv-folds and warrants further investigation. Future work will consider additional features that may improve the ability to discriminate between KEX and KFL exercises. Additional feature selection methods such as recursive feature elimination and removing features with low variance will be investigated to see whether SVM classification performance can be further enhanced.

Nitroxide‐Mediated Polymerization of Bio‐Based Farnesene with a Functionalized Methacrylate

AbstractFarnesene (Far) is a bio‐based terpene monomer that is similar in structure to commercially used dienes like butadiene and isoprene. Nitroxide‐mediated polymerization (NMP) is adept for the polymerization of dienes, but not particularly effective at controlling the polymerization of methacrylates using commercial nitroxides. In this study, Far is statistically copolymerized with a functional methacrylate, glycidyl methacrylate (GMA), by NMP using N‐succinimidyl modified commercial BlocBuilder (NHS‐BB) initiator. Reactivity ratios are determined to be r Far = 0.54 ± 0.04 and r GMA = 0.24 ± 0.02. The ability of the poly(Far‐stat‐GMA) chains to reinitiate for chain extension with styrene showed a clear shift in molecular weight and monomodal distribution. Copolymerizations using a new alkoxyamine, Dispolreg 007 (D7), is explored as it is shown to homopolymerize methacrylates, but not yet reported for statistical copolymerizations. Bimodal molecular weight distributions are observed when an equimolar ratio of Far and GMA is copolymerized with D7 due to slow decomposition of the initiator, but chain ends are active as shown by successful chain extension with styrene. Both NHS‐BB and D7 initiators are used to synthesize poly[Far‐b‐(GMA‐stat‐Far)] and poly(Far‐b‐GMA) diblock copolymers. While the NHS‐BB initiated polymer chains have lower dispersity, D7 exhibits more linear polymerization kinetics and maintains more active chain ends.

Dynamic and Static Postural Control in Volleyball Players with Transfemoral Amputation

ABSTRACT Introduction: A decrease in postural control and proprioception is a common result of lower limb amputation. However, postural control adaptation in Paralympic sitting volleyball players with lower limb amputation is not yet understood. Objective: The purpose of this cross-sectional controlled study was to investigate static and dynamic postural control in sitting volleyball players with unilateral transfemoral amputation. Methods: Sixteen subjects participated in the study, eight of whom were amputees with unilateral transfemoral amputation (amputee group: age: 33.5 ± 5.6 years, weight: 77.7 ± 5.3 kg, height: 179.4 ± 5.3 cm) and eight physically active non-amputees (control group age: 27.2 ± 8.4 years, weight: 82.7 ± 6.6 kg, height: 178.7 ± 6.1 cm). Static and dynamic postural control was evaluated using the Neurocom® Balance Master System platform (Modified Clinical Test of Sensory Interaction on Balance, Limits of Stability, Rhythmic Weight Shift, Sit-to-Stand, Walk Across, and Step and Quick Turn). Statistical analyses were performed with the Shapiro-Wilk test, Levene's test, and Student's t-test for paired samples (p &lt;0.05). Results: The amputee group demonstrated impaired postural control in all tests when compared to the control group (p &lt;.05) for all postural tests except for the rhythmic change and sit-to-stand tests (p &gt;.05). Conclusion: Despite training in sitting volleyball, our results demonstrated that amputees have poorer postural control in both static and dynamic tasks when compared to physically active non-amputees. Level of Evidence II; Prognostic Studies—Investigating the Effect of a Patient Characteristic on Disease Outcome / Retrospectivef Study.

Development of a comprehensive mobile assessment of pressure (CMAP) system for pressure injury prevention for veterans with spinal cord injury

Objective: This paper reports the iterative redesign, feasibility and usability of the Comprehensive Mobile Assessment of Pressure (CMAP) system’s mobile app used by Veterans with SCI.Design: This three-year, multi-staged study used a mixed-methods approach.Setting: Minneapolis VA Health Care System, Minneapolis, Minnesota.Participants: Veterans with spinal cord injury (N = 18).Interventions: Veterans with spinal cord injury engaged in iterative focus groups and personal interviews, sharing their needs and desires for the CMAP app redesign. App developers used these data for the redesign. The redesigned CMAP app was tested for six-weeks in users’ homes.Outcome Measures: Quantitative (surveys) and qualitative (interviews) methods measured feasibility for self-management of seating pressure. Qualitative data were audio recorded, transcribed, anonymized, and coded. Survey data were analyzed using summary statistics.Results: After the CMAP system’s redesign, the in-home use interview found: (1) any tool that can assist in prevention and monitoring of skin ulcers is important; (2) the desired key features are present in the app; (3) the main barrier to CMAP use was inconsistent functionality; (4) when functioning as expected, the live pressure map was the central feature, with reminders to weight shift also of high importance. The survey found: power wheelchair users tended to score closer than manual wheelchair users to the positive response end ranges on two separate surveys.Conclusions: Overall both the power and manual wheelchair users reported that they wanted to use the system, felt confident using the system, and that the functions of the system were well integrated.

Temperature-dependent valence state within the metallic phase of BaV10O15 probed by hard x-ray photoelectron spectroscopy

We have studied electronic properties of ${\mathrm{BaV}}_{10}{\mathrm{O}}_{15}$ in the intermediate-temperature phase as well as in the high-temperature metallic phase by using hard x-ray photoemission spectroscopy (HAXPES). The V $2p$ HAXPES show a shift in the high-temperature phase between 300 and 245 K which is similar to the shift of spectral weight near the Fermi edge. The binding energy of the O $1\mathit{s}$ HAXPES peak does not change except a slight shift of the lower binding energy edge in the opposite direction between 300 and 180 K across the transition to the intermediate-temperature phase. This behavior is in sharp contrast to the transition to the low-temperature insulating phase where V $2p$ and O $1s$ HAXPES show dramatic shifts in the same direction. This indicates that the charge-orbital change in the intermediate-temperature phase is driven by the correlated V $3d$ electrons and is electronic. The ${\mathrm{V}}^{2.5+}\text{\ensuremath{-}}{\mathrm{V}}^{2.5+}$ bond ordering is related to the metallic contribution and gradually decreases with cooling from 300 K. The valence-band HAXPES show the metallic features of the pseudogap behavior near the Fermi edge in and above the intermediate-temperature phase due to ${\mathrm{V}}^{2.5+}\text{\ensuremath{-}}{\mathrm{V}}^{3+}$ charge fluctuation. The magnitude of the pseudogap increases from 300 to 180 K in parallel with the gradual breaking of the ${\mathrm{V}}^{2.5+}\text{\ensuremath{-}}{\mathrm{V}}^{2.5+}$ bond and formation of trimers.

Fluoxetine-induced alteration of murine gut microbial community structure: evidence for a microbial endocrinology-based mechanism of action responsible for fluoxetine-induced side effects.

BackgroundDepression and major depressive disorder affect 25% of the population. First line treatment utilizing selective serotonin reuptake inhibitors (SSRIs) have met with limited success due to well-recognized negative side effects which include weight gain or loss. This inability to control unwanted side effects often result in patients stopping their antidepressant medications. The mechanisms underlying the failure of SSRIs are incompletely understood.MethodsMale CF-1 mice (5 weeks of age, N = 10 per group) were per orally administered fluoxetine (20 mg per kg body weight) or diluent daily for 29 days. During this time fecal specimens were collected at three defined time points (0, 15 and 29 days). At the conclusion of the 29-day dosing regimen, animals were subjected to two behavioral assessments. For bacterial identification of the microbiota, 16S rRNA gene sequencing was performed on 60 fecal specimens (three specimens per mouse time course, N = 20 mice) using Illumina MiSeq. Analysis of community sequence data was done using mothur and LEfSe bioinformatic software packages.ResultsDaily per oral administration of fluoxetine for 29 days to male mice resulted in a significant, time dependent, alteration in microbial communities accompanying changes in body weight. The calculated species richness and diversity indicators of the murine fecal microbial communities were inconsistent and not significantly different between the groups. Among the phylotypes decreased in abundance due to fluoxetine administration were Lactobacillus johnsonii and Bacteroidales S24-7 which belong to phyla associated with regulation of body mass. The observed changes in body weight due to fluoxetine administration mimicked the dramatic shifts in weight gain/loss that has been observed in humans. Further, at the conclusion of the 29-day dosing regimen fluoxetine-dosed animals evidenced a mild anxiogenic-like behavior.DiscussionWe report that the most widely used antidepressant, fluoxetine, which is an SSRI-type drug, results in the selective depletion of gut microbiota, specifically the Lactobacilli which are involved in the regulation of body weight. Concomitantly, fluoxetine administration increases the abundance of phylotypes related to dysbiosis. Since Lactobacilli have been previously shown to possess a known biogenic amine transporter that regulates the uptake of fluoxetine, it is proposed that a microbial endocrinology-based mechanistic pathway is responsible for the ability of SSRIs to selectively negatively impact beneficial microbiota. The results of this study therefore suggest that the negative clinical side effects due to fluoxetine administration may be due to alterations in gut microbiota. Further, the data also suggests that supplementation of bacterial genera directly affected by fluoxetine administration may prove useful in ameliorating some of the well-known side effects of chronic fluoxetine administration such as weight alterations.