Arm Segments Research Articles

Molecular Dynamics Reveal Key Steps in BAR-Related Membrane Remodeling.

Endocytosis plays a complex role in pathogen-host interactions. It serves as a pathway for pathogens to enter the host cell and acts as a part of the immune defense mechanism. Endocytosis involves the formation of lipid membrane vesicles and the reshaping of the cell membrane, a task predominantly managed by proteins containing BAR (Bin1/Amphiphysin/yeast RVS167) domains. Insights into how BAR domains can remodel and reshape cell membranes provide crucial information on infections and can aid the development of treatment. Aiming at deciphering the roles of the BAR dimers in lipid membrane bending and remodeling, we conducted extensive all-atom molecular dynamics simulations and discovered that the presence of helix kinks divides the BAR monomer into two segments-the "arm segment" and the "core segment"-which exhibit distinct movement patterns. Contrary to the prior hypothesis of BAR domains working as a rigid scaffold, we found that it functions in an "Arms-Hands" mode. These findings enhance the understanding of endocytosis, potentially advancing research on pathogen-host interactions and aiding in the identification of new treatment strategies targeting BAR domains.

Evaluating Joint Angle Data for Clinical Assessment Using Multidimensional Inverse Kinematics with Average Segment Morphometry.

Movement analysis is a critical tool in understanding and addressing various disabilities associated with movement deficits. By analyzing movement patterns, healthcare professionals can identify the root causes of these alterations, which is essential for preventing, diagnosing, and rehabilitating a broad spectrum of medical conditions, disabilities, and injuries. With the advent of affordable motion capture technologies, quantitative data on patient movement is more accessible to clinicians, enhancing the quality of care. Nonetheless, it is crucial that these technologies undergo rigorous validation to ensure their accuracy in collecting and monitoring patient movements, particularly for remote healthcare services where direct patient observation is not possible. In this study, motion capture technology was used to track upper extremity movements during a reaching task presented in virtual reality. Kinematic data was then calculated for each participant using a scaled dynamic inertial model. The goal was to evaluate the accuracy of joint angle calculations using inverse kinematics from motion capture relative to the typical movement redundancy. Shoulder, elbow, radioulnar, and wrist joint angles were calculated with models scaled using either direct measurements of each individual's arm segment lengths or those lengths were calculated from individual height using published average proportions. The errors in joint angle trajectories calculated using the two methods of model scaling were compared to the inter-trial variability of those trajectories. The variance of this error was primarily within the normal range of variability between repetitions of the same movements. This suggests that arm joint angles can be inferred with good enough accuracy from motion capture data and individual height to be useful for the clinical assessment of motor deficits.

Dynamic balance of circles with one support point on pommel horse exercise

Double-leg circles on pommel horse exercises require a high degree of dynamic balance. However, theoretical conditions for maintaining dynamic balance are unclear. The purpose of this paper is to propose a simple theoretical model of the dynamic balance of the circles, and to illustrate its qualitative properties. To this end, the body of a gymnast is simply modeled as one rigid body with one support point, and symmetric and constant-velocity circles are assumed in most analyses. The condition that the torques of wrist and shoulder joints are zero is assumed as a dynamic balance condition with minimum strength. A control law is proposed to demonstrate the motion. Various properties of the dynamic balance condition are analyzed as follows. In the symmetric circles, (1) as the period of a circle decrease, the heights and the radius of the toes increase, and (2) the rotation of the body around its longitudinal axis in the double-leg circle has the effect of lifting the toes. (3) The shoulder and wrist torques can change the pose around the dynamic balance condition. In asymmetric circles, (4) the radius of the center of mass (CoM) increases as the angular velocity of the CoM around the support point decreases, and (5) the body angle with respect to the horizontal plane increases as the upward acceleration of the CoM increases. Moreover, mechanical principles of the circles are discussed as follows. (6) The CoM motion during the symmetric circles of the simple model can be related to the conical pendulum. In the simple model, (7) the pommel reaction force should be parallel to the arm segment when the wrist torque and the shoulder torque are equal or zero, and (8) to change the vertical component of the angular momentum of the body around the support point, the wrist torque around the vertical axis is needed. These results provide theoretical and qualitative insights into understanding and improving pommel horse exercise.

Temporal localization of upper extremity bilateral synergistic coordination using wearable accelerometers.

The human upper extremity is characterized by inherent motor abundance, allowing a diverse array of tasks with agility and adaptability. Upper extremity functional limitations are a common sequela to Stroke, resulting in pronounced motor and sensory impairments in the contralesional arm. While many therapeutic interventions focus on rehabilitating the weaker arm, it is increasingly evident that it is necessary to consider bimanual coordination and motor control. Participants were recruited to two groups differing in age (Group 1 (n=10): 23.4 ±2.9 years, Group 2 (n=10): 55.9 ±10.6 years) for an exploratory study on the use of accelerometry to quantify bilateral coordination. Three tasks featuring coordinated reaching were selected to investigate the acceleration of the upper arm, forearm, and hand during activities of daily living (ADLs). Subjects were equipped with acceleration and inclination sensors on each upper arm, each forearm, and each hand. Data was segmented in MATLAB to assess inter-limb and intra-limb coordination. Inter-limb coordination was indicated through dissimilarity indices and temporal locations of congruous movement between upper arm, forearm, or hand segments of the right and left limbs. Intra-limb coordination was likewise assessed between upper arm-forearm, upper arm-hand, and forearm-hand segment pairs of the dominant limb. Acceleration data revealed task-specific movement features during the three distinct tasks. Groups demonstrated diminished similarity as task complexity increased. Groups differed significantly in the hand segments during the buttoning task, with Group 1 showing no coordination in the hand segments during buttoning, and strong coordination in reaching each button with the upper arm and forearm guiding extension. Group 2's dissimilarity scores and percentages of similarity indicated longer periods of inter-limb coordination, particularly towards movement completion. Group 1's dissimilarity scores and percentages of similarity indicated longer periods of intra-limb coordination, particularly in the coordination of the upper arm and forearm segments. The Expanding Procrustes methodology can be applied to compute objective coordination scores using accessible and highly accurate wearable acceleration sensors. The findings of task duration, angular velocity, and peak roll angle are supported by previous studies finding older individuals to present with slower movements, reduced movement stability, and a reduction of laterality between the limbs. The theory of a shift towards ambidexterity with age is supported by the finding of greater inter-limb coordination in the group of subjects above the age of thirty-five. The group below the age of thirty was found to demonstrate longer periods of intra-limb coordination, with upper arm and forearm coordination emerging as a possible explanation for the demonstrated greater stability.

3D octopus kinematics of complex postures: Translation to long, thin, soft devices and their potential for clinical use.

Octopuses are capable of complex arm movements. Unfortunately, experimental barriers and lack of a robust analysis method made it difficult to quantify the three-dimensional (3D) kinematics of soft, flexible bodies, such as the octopus arm. This information is not only crucial for understanding the posture of the animal's arm but also for the development of similarly designed soft, flexible devices. The primary goal of this work was to create a method to comprehensively quantify complex, 3D postures of octopus (Octopus Bimaculoides) arms in a manner that is conducive and translatable to octopus arm-inspired devices for health monitoring and rehabilitation. In this study, 3D underwater motion capture was used to collect kinematic data on both live octopuses and disembodied arms that still had neural activity. A new method was developed to define how arm curvature and regional segments were oriented relative to each other in 3D. This included identification of the bend within a segment along with the computation of the relative orientation between segments, thus permitting the complete quantification of complex arm motions. By comparing vector-based and radius of curvature-based approaches to magnitude of curvature, it was clear that the vector-based approach was less dependent on the length of a segment and that its reported ranges of motion were translatable for outcome measures associated with clinical use. The new approach for the relative orientation of each segment of the octopus arm resulted in the capability of describing the octopus arm in many unique postures, such as straight, simple bending, and complex bending as it utilized the three rotational angles. This method and its application to octopus arms will yield new information that can be used to better communicate and track not only octopus arm movements but in the development of complex, segmented, soft-bodied devices that can be used in health monitoring and rehabilitation.

On the Structure of the Sagittarius Spiral Arm in the Inner Milky Way

We report measurements of trigonometric parallax and proper motion for two 6.7 GHz methanol and two 22 GHz water masers located in the far portion of the Sagittarius spiral arm as part of the BeSSeL Survey. Distances for these sources are estimated from parallax measurements combined with three-dimensional kinematic distances. The distances of G033.64−00.22, G035.57−00.03, G041.15−00.20, and G043.89−00.78 are 9.9 ± 0.5, 10.2 ± 0.6, 7.6 ± 0.5, and 7.5 ± 0.3 kpc, respectively. Based on these measurements, we suggest that the Sagittarius arm segment beyond about 8 kpc from the Sun in the first Galactic quadrant should be adjusted radially outward relative to previous models. This supports the suggestion of Xu et al. that the Sagittarius and Perseus spiral arms might merge in the first quadrant before spiraling inward to the far end of the Galactic bar.

Power and velocity performance of swing movement in the adolescent male volleyball players – age and positional difference

PurposeThe performance of swing movement during spikes and serves plays a crucial role in determining the outcomes of volleyball matches. This study aims to explore the effects of the participation of the trunk and lower limbs’ involvement on the velocity and power of the swing movement of adolescent male volleyball players, as well as the differences in power and velocity performance of the swing movement among different ages and specific positions.MethodsThe study involved 22 adolescent male volleyball players, with 11 high school students and 11 middle school students. The Kineo Globus equipment was used to assess the swing movement performance involving different segments, including arm swing movement only involving arm limb participation; upper swing movement involving trunk and arm limb participation; and whole body swing movement involving lower limb, trunk, and arm limb participation. The measured parameters included power and velocity performance levels. Before the test, each subject practiced three movement patterns twice.ResultsThe study found that swing movement involving both the trunk and arm limbs had significantly higher average (F = 17.70, p < 0.001) and peak power performance (F = 31.47, p < 0.001), as well as in average (F = 9.14, p = 0.03) and peak velocity performance (F = 23.17, p < 0.001). There were no significant differences in average (F = 17.70; p = 0.46) and peak power (F = 31.47, p = 0.94), as well as in average (F = 9.14, p = 0.99) and peak velocity performance (F = 23.17, p = 0.90) between movements involving the whole body and those involving the trunk and upper limbs. Among different age groups, the swing movement performance of middle school athletes showed significant enhancements in both average (F = 9.20, p < 0.001) and peak power (F = 19.93, p < 0.001), as well as in average (F = 10.75, p < 0.001) and peak velocity (F = 34.35, p < 0.001) when arm swing with trunk involvement was compared to arm swing movement. High school athletes also showed significant improvements in peak velocity (F = 34.35, p < 0.001), peak power (F = 17.31, p < 0.001), and average power (F = 9.41, p < 0.001) during upper swing movements, except for average velocity performance (F = 1.56, p = 0.21), when compared to arm swing movement. The increase rate in average velocity performance of swing movements involving trunk participation was significantly higher in middle school athletes than in high school athletes (p < 0.001). Among athletes in specific positions, Middle Blocker (MB) players exhibited significantly better average power performance in swing movements involving trunk and arm limb participation compared to Outside Hitter (OH) players (p = 0.04). Furthermore, the rate of average (p = 0.01) and peak (p = 0.03) power change during upper swing movements involving lower limb participation was significantly higher among OH players than MB players.ConclusionsThe involvement of the trunk segment has been observed to significantly improve power and velocity in swing movements during spike and serves among adolescent male volleyball players. This underscores the importance of coordination between the trunk and arm in influencing swing movement performance during spikes and serves. High school athletes demonstrate superior power and velocity in arm swing movements compared to middle school athletes. MB exhibits greater power in upper limb swing movements than OH, although OH players show better coordination between the arm, trunk, and lower limb segments in the swing movement. To enhance swing movement performance in adolescent male volleyball players, particularly focusing on the trunk segment was crucial. Specialized physical training programs should target improving both arm strength and rotational power of the trunk simultaneously. This approach would help in consistently enhancing coordination between the trunk and arms, ultimately leading to optimized force generation during swing movements such as spikes and serves.

KINEMATIC ANALYSIS OF CROSS ON TRAINING AND COMPETITION RINGS: COMPARISON BETWEEN ELITE AND INTERNATIONAL LEVEL GYMNASTS

Auxiliary devices are used to train gymnastics skills. Based on the principles of training specificity, this study aimed to investigate the effectiveness of a training device for the static cross posture on Men’s Artistic Gymnastics rings through kinematic analysis. Twelve national team gymnasts were divided into two groups, based on their competitive results: the elite group (age: 21.8±3.2 years) and the international group (age: 19.3±3.3 years) performed the cross three times under both conditions: standard competition rings, and training rings with an auxiliary device. The videos were digitised and analysed with shoulder angles as trunk and arm segments. The variables included the right and the left shoulder angles in the frontal plane, as well as any asymmetry of those angles. Two-way ANOVA (conditions versus groups) and individual t-test statistics were conducted. Both groups performed the cross on training rings with increased abduction at both right (p&lt;0.001) and left (p&lt;0.001) shoulders and reduced asymmetry (p=0.01) than on competition rings. These kinematic improvements would translate into competition-typical score improvements of 0.1 to 0.3 points, and enhanced shoulder joint stability. Hence, the training rings with an auxiliary device effectively replicate skill-specific joint angles, adhering to the kinematics principles of training specificity for the static cross posture on rings, thus benefiting both elite and international-level gymnasts.

Bioelectrical impedance vector analysis as an indicator of malnutrition in children under five years with and without pneumonia in Mchinji District, Malawi: An exploratory mixed-methods analysis

Background Bioelectrical impedance vector analysis (BIVA) is a non-invasive approach to assessing body composition and cellular health, which may improve the assessment of nutritional status in sick children. We explored the reliability, clinical utility, and acceptability of BIVA, as an indicator of nutritional status for children under five years with and without pneumonia, in Malawi. Methods We conducted a parallel convergent mixed-methods exploratory study in Mchinji District Hospital, Malawi, in 2017. We recruited a convenience sample of children aged 0–59 months with clinical pneumonia, and without an acute illness. Children had duplicate anthropometric and BIVA measurements taken. BIVA measurements of phase angle were taken of the whole body, and trunk and arm segments. Reliability was assessed by comparing the variability in the two measures, and clinical utility by estimating the association between anthropometry and phase angle using linear regression. Focus group discussions with healthcare workers who had not previously used BIVA instrumentation were conducted to explore acceptability. Results A total of 52 children (24 with pneumonia and 28 healthy) were analysed. The reliability of sequential phase angle measurements was lower than anthropometric measurements, but trunk and arm segments performed better. The largest associations with phase angle were a negative relationship with weight-for-age z-score (WAZ) in children with pneumonia in the trunk segment, and a positive association with WAZ in the full body measurement in healthy children. Healthcare workers in focus group discussions expressed trust in BIVA technology and that it would enable more accurate diagnosis of malnutrition; however, they raised concerns about the sustainability and necessary resources to implement BIVA. Conclusions While healthcare workers were positive towards BIVA as a novel technology, implementation challenges should be expected. The differential direction of association between anthropometry and phase angle for children with pneumonia warrants further investigation.

A new species of the genus Ophiomyxa (Echinodermata: Ophiuroidea: Ophiomyxidae) from the Mallorca Channel seamounts in the western Mediterranean.

A new species belonging to the ophiuroid genus Ophiomyxa is described from the Mallorca Channel seamount, in the western Mediterranean Sea. It can be distinguished from other Ophiomyxa species by the lack of interradial marginal plates, three arm spines, the presence of two thin, transparent and completely perforated dorsal arm plates on each arm segment, the separate heptagonal ventral arm plates, the disk integument full of transparent rounded scales with scattered perforated ossicles, and a characteristic coloration of the disk, which in the living specimen is brown with abundant scattered bright white spots. Molecular analyses based on cytochrome c Oxidase subunit I (DNA barcode) clearly support the assignment of the new species to Ophiomyxa. This discovery highlights the importance of the Mallorca Channel seamounts for the Mediterranean biodiversity conservation, as they seem to provide a suitable habitat for several invertebrate species, including recent descriptions of species and new Mediterranean records, which apparently have not established permanent populations along the closest continental margin.

A comparison of minimum segment models for the estimation of centre of mass position and velocity for slip recovery during a bathtub transfer task

BackgroundExploring the use of minimum marker sets is important for balancing the technical quality of motion capture with challenging data collection environments and protocols. While minimum marker sets have been demonstrated to be appropriate for evaluation of some motion patterns, there is limited evidence to support model choices for abrupt, asymmetrical, non-cyclic motion such as balance disturbance during a bathtub exit task. Research questionHow effective are six models of reduced complexity for the estimation of centre of mass (COM) displacement and velocity, relative to a full-body model. MethodsEight participants completed a bathtub exit task. Participants received a balance perturbation as they crossed the bathtub rim, stepping from a soapy wet bathtub to a dry floor. Six reduced models were developed from the full, 72-marker, 12 segment 3D kinematic data set. Peak displacement and velocity of the body COM, and RMSE (relative to the full-body model) for displacement and velocity of the body COM were determined for each model. ResultsMain effects were observed for peak right, left, anterior, posterior, upwards and downwards motion, and peak left, anterior, posterior, upwards and downwards velocity. Time-varying (RMSE) was smaller for models including the thighs than models not containing the thighs. In contrast, inclusion of upper arm, forearm, and hand segments did not improve model performance. The model containing the sacrum marker only consistently performed the worst across peak and RMSE metrics. SignificanceFindings suggest a simplified centre of mass model may adequately capture abrupt, asymmetrical, non-cyclic tasks, such as balance disturbance recovery during obstacle crossing. A reduced kinematic model should include the thighs, trunk and pelvis segments, although models that are more complex are recommended, depending on the metrics of interest.

Bioelectrical impedance vector analysis as an indicator of malnutrition in children under five years with and without pneumonia in Mchinji District, Malawi: An exploratory mixed-methods analysis

Background Bioelectrical impedance vector analysis (BIVA) is a non-invasive approach to assessing body composition and cellular health, which may improve the assessment of nutritional status in sick children. We explored the reliability, clinical utility, and acceptability of BIVA, as an indicator of nutritional status for children under five years with and without pneumonia, in Malawi. Methods We conducted a parallel convergent mixed-methods exploratory study in Mchinji District Hospital, Malawi, in 2017. We recruited a convenience sample of children aged 0–59 months with clinical pneumonia, and without an acute illness. Children had duplicate anthropometric and BIVA measurements taken. BIVA measurements of phase angle (PhA) were taken of the whole body, and trunk and arm segments. Reliability was assessed by comparing the variability in the two measures, and clinical utility by estimating the association between anthropometry and PhA using linear regression. Focus group discussions with healthcare workers who had not previously used BIVA instrumentation were conducted to explore acceptability. Results A total of 52 children (24 with pneumonia and 28 healthy) were analysed. The reliability of sequential PA measurements was lower than anthropometric measurements, but trunk and arm segments performed better. The largest associations with PhA were a negative relationship with weight-for-age z-score (WAZ) and PhA in children with pneumonia in the trunk segment, and a positive association with WAZ in the full body measurement in healthy children. Healthcare workers in focus group discussions expressed trust in BIVA technology and that it would enable more accurate diagnosis of malnutrition; however, they raised concerns about the sustainability and necessary resources to implement BIVA. Conclusions While healthcare workers were positive towards BIVA as a novel technology, implementation challenges should be expected. The differential direction of association between anthropometry and PhA for children with pneumonia warrants further investigation.

Impact of Protease Inhibitor-Based Highly Active Antiretroviral Therapy on Fetal Subcutaneous Fat Tissue in HIV-Pregnant Women in a Middle-Income Country.

HIV infection continues to be a global public health challenge, affecting approximately 1.7 million reproductive-aged women. Protease inhibitor-based highly active antiretroviral therapy (PI-HAART) has significantly reduced the risk of vertical transmission of HIV from mother to child. Nevertheless, concerns linger regarding the long-term effects, particularly on body composition, notably subcutaneous fat tissue (SFT). Although HIV-associated lipodystrophy syndrome (LS) has been well documented in adults and older children, its impact on fetuses exposed to PI-HAART remains underexplored. This study aims to evaluate SFT in the fetuses of HIV-pregnant women exposed to PI-HAART, assessing the potential clinical implications. We conducted a comparative study between HIV-pregnant women receiving PI-HAART and an HIV-negative control group. Fetometry measurements were obtained via 3D ultrasound. SFT in the fetal arm and thigh segments was assessed. Data were analyzed using lineal multivariate regression and receiver-operating characteristics (ROC)-curve analysis. Fetuses exposed to PI-HAART exhibited a significant reduction in subcutaneous fat, particularly in the proximal third-middle union of the femur (coefficient: -2.588, p = 0.042). This reduction was correlated with lower newborn serum glucose levels (65.7 vs. 56.1, p = 0.007; coefficient: -1.277, p = 0.045). Our study sheds light on the connection between PI-HAART, fetal subcutaneous fat, and neonatal health. These findings might reveal the long-lasting effects of PI-HAART on newborns and children's well-being. Our results emphasize the need for a more balanced approach to managing pregnant women with HIV in developing countries and open new venues for research on the impact of intrauterine PI-HAART exposure on energy metabolism and fetal programming.

Design, self-calibration and compliance control of modular cable-driven snake-like manipulators

The high flexibility of cable-driven snake-like manipulators (CDSM) makes them well-suited for tasks in narrow and unstructured spaces. However, ensuring both stiffness and load capacity while maintaining good compliance for safe human-robot interaction is challenging. We design a modular cable-driven snake-like manipulator (MCDSM) and improve its active compliance through impedance control. Firstly, the detachable arm segments of the MCDSM can adapt to multiple tasks. The modular drive units and plug-in drive boxes facilitate quick installation and maintenance. Furthermore, the modified kinematic model considers the torsion angle information of the detachable arm segments. Based on this model, a self-calibration method using redundant cable length is proposed for cable space to joint space. Moreover, a dynamic model for the MCDSM is established. An optimization method for cable tension in joint space is proposed to eliminate the coupling phenomenon during tension control. Finally, a compliant control method for the MCDSM is presented by combining the inner loop for the cable tension control. The feasibility of the proposed methods is demonstrated through simulations and experiments with a prototype.

Path planning with obstacle avoidance for soft robots based on improved particle swarm optimization algorithm

Soft-bodied robots have the advantages of high flexibility and multiple degrees of freedom and have promising applications in exploring complex unstructured environments. Kinematic coupling exists for the soft robot in a problematic space environment for motion planning between the soft robot arm segments. In solving the soft robot inverse kinematics, there are only solutions or even no solutions, and soft robot obstacle avoidance control is tough to exist, as other problems. In this paper, we use the segmental constant curvature assumption to derive the positive and negative kinematic relationships and design the tip self-growth algorithm to reduce the difficulty of solving the parameters in the inverse kinematics of the soft robot to avoid kinematic coupling. Finally, by combining the improved particle swarm algorithm to optimize the paths, the convergence speed and reconciliation accuracy of the algorithm are further accelerated. The simulation results prove that the method can successfully move the soft robot in complex space with high computational efficiency and high accuracy, which verifies the effectiveness of the research.

Evaluation of Hip Characteristics in Baseball and Softball Athletes with and Without Throwing Arm Pain.

During throwing, the lower extremity assists in the generation and transfer of momentum. Lower extremity stability assists in this transfer by providing a base for distal mobility of the arm segments. This study aimed to determine differences between hip rotational range of motion and strength based on the presence of throwing-arm pain (yes/no) and throwing sport (baseball/softball). We hypothesized those experiencing pain would display decreases in hip range of motion and strength, and that softball players would display greater range of motion than baseball, but less strength based on sex-specific characteristics. Forty-four baseball (13±2 years, 165.2±13.0 cm, 58.5±13.4 kg) and 50 softball players (13±2 years, 160.9±11.2 cm, 62.7±17.9 kg) participated. Multivariate analysis of variance tests (2×2) determined differences in bilateral hip range of motion, total arc of motion, and strength between pain status and sport. There were no significant interactions (>0.05) for pain status and sport on hip range of motion, total arc of motion, and strength. Furthermore, no significant main effects (>0.05) were found for pain status or sport alone on range of motion or strength. Future work should be directed at explaining the effects of hip characteristics on the throwing motion and how it equates to throwing-arm health.

FRI028 Multiple Symmetric Lipomatosis As A Model For Understanding The Importance Of Mitochondria Function On Adipose Tissue Biology

Abstract Disclosure: M.C. Foss de Freitas: Advisory Board Member; Self; PTC Therapeutics. A. DillGomes: None. F. Grissi: None. S. Imam: None. E.A. Oral: Consulting Fee; Self; Regeneron Pharmaceuticals, Aegerion Pharmaceuticals, receives payment, Ionis Pharmaceuticals Inc., Third Rock Ventures, Rejuvenate Inc. Grant Recipient; Self; Regeneron Pharmaceuticals, Ionis Pharmaceuticals Inc., Aegerion Pharmaceuticals, Novo Nordisk, Rhythm pharmaceuticals, Fractyl Laboratories, GID Dynamics. Other; Self; Aegerion Pharmaceuticals. Multiple symmetric lipomatosis (MSL) is a rare disease characterized by symmetrical deposition of adipose tissue (AT) in the neck and upper body, associated with lipoatrophy in the distal segments of arms and legs and has been recently associated with biallelic mitofusin (MFN) 2 pathogenic variants. We are currently following multiple pedigrees, some with two affected siblings with MFN2-associated MSL. Homozygous MFN2 R707W (c.2119C&amp;gt;T) pathogenic variant was detected in all but one patient. Briefly, patient 1 is a 43-year-old female who first reported increased head and neck adiposity with increased muscularity of her extremities around 13 years old. Her sister is also affected (patient 2). The father was confirmed to be heterozygous for the pathogenic variant R707W. Patient 3 (20-year-old male) and patient 4 (17-year-old male) are siblings from another pedigree. The older sibling in this pedigree has evidence of axonal neuropathy and feet deformities. Both parents are heterozygous for R707W. Patient 5 () is a 54-year-old female reporting face and upper body fat tissue expansion starting when she was 15 years old; she also presented with distal axonal neuropathy. Her sister (patient 6) has clinical manifestations compatible with MSL (patient 6). Patient 7, who is a compound heterozygote with the R707W and D536T variants, is a 59-year-old woman who started noticing unusual body fat distribution at age 17 and progressively developed myopathy and neuropathy associated with Charcot-Marie-Tooth disease, and she also developed acromegalic features and severe macroglossia. All patients share the phenotypic features of the disease characterized by the accumulation of fat in the upper part of the body and lipoatrophic upper and lower limbs. Although variable, all patients have some degree of insulin resistance, but none of them has crossed the clinical threshold of diabetes so far. Triglyceride levels are elevated, ranging from around 200mg/dL-1300mg/dL. Remarkably, all patients have very low leptin levels and an enlarged liver with mildly impaired liver function. Obstructive sleep apnea is diagnosed in four patients due to the accumulation of AT in the neck. All patients have enlarged tongues. Patient 7 has an elevated IGF-1 level. Interestingly, all patients have been noted to have elevated GDF-15 levels (ranging from 1662-2813pg/mL). Affected patients have variable degrees of scoliosis, likely a secondary effect of adipose tissue overgrowth during adolescence. Although the mechanism of disease is not clear, R707 is in the carboxy-terminal coiled-coil domain HR2 of MFN2 and may regulate mitochondrial membrane fusion. A better understanding of the metabolic impact of MFN2 R707W in lipolysis and energy expenditure will provide new insights into patient care, hopefully improving these patients' quality of life. Presentation: Friday, June 16, 2023

Exact shell solutions for conical springs. III. Belleville springs with variable thickness

PurposeIn the current manuscript, the authors examine the Belleville spring with the variable thickness. The thickness is assumed to be variable along the meridional and parallel coordinates of conical coordinate system. The calculation of the Belleville springs includes the cases of the free gliding edges and the edges on cylindric curbs, which constrain the radial movement. The equations developed here are based on common assumptions and are simple enough to be applied to the industrial calculations.Design/methodology/approachIn the current manuscript, the authors examine the Belleville spring with the variable thickness. The calculation of the Belleville springs investigates the free gliding edges and the edges on cylindric curbs with the constrained radial movement. The equations developed here are based on common assumptions and are simple enough to be applied to the industrial calculations.FindingsThe developed equations demonstrate that the shift of the inversion point to the inside edge does not influence the bending of the cone. On the contrary, the character of the extensional deformation (circumferential strain) of the middle surface alternates significantly. The extension of the middle surface of free gliding spring occurs outside the inversion. The middle surface of the free gliding spring squeezes inside the inversion point. Contrarily, the complete middle surface of the disk spring on the cylindric curb extends. This behavior influences considerably the function of the spring.Research limitations/implicationsA slotted disk spring consists of two segments: a disk segment and a number of lever arm segments. Currently, the calculation of slotted disk spring is based on the SAE formula (SAE, 1996). This formula is limited to a straight slotted disk spring with freely gliding inner and outer edges.Practical implicationsThe equations developed here are based on common assumptions and are simple enough to be applied to the industrial calculations. The developed method is applicable for disk springs with radially constrained edges. The vertical displacements of a disk spring result from an axial load uniformly distributed on inner and outer edges. The method could be directly applied for calculation of slotted disk springs.Originality/valueThe nonlinear governing equations for the of Belleville spring centres were derived. The equations describe the deformation and stresses of thin and moderately thick washers. The variation method is applicable for the disc springs with free gliding and rigidly constrained edges. The developed method is applicable for Belleville spring with radially constrained edges. The vertical displacements of a disc spring result from an axial load uniformly distributed on inner and outer edges.

Acute Radial Compressive Neuropathy: The Most Common Injury Induced by Japanese Rope Bondage.

Japanese rope bondage (RB), or Shibari, is an art form involving the voluntary and aesthetic binding of a person with a rope, which may result in compression injuries to peripheral nerves. To investigate the nature and extent of nerve injuries associated with this practice, we conducted a survey of four experienced RB practitioners (riggers) and participants who were willing to share their experiences of injury. Injuries presented acutely and immediately following full-body suspensions, with a total of 10 individuals (16 injuries) identified with damage to the radial, axillary, or femoral nerves. Notably, the radial nerve was the most commonly affected structure in our patient cohort, with 90.0% of individuals experiencing an injury at this level. We present a rare case of acute repeated compression of the radial nerve during full-body suspension RB. A 29-year-old female was suspended for 25 minutes using a 6-mm jute rope, resulting in wrist and finger drop, as well as reduced sensation in the left hand. Analysis revealed a 77.3% conduction block in the upper arm segment. Improvement was observed after three months, fully achieved after five months. Seventeen months later, re-compression of both radial nerves occurred during a similar suspension lasting 8-10 minutes. Improvement occurred after one week, fully achieved after four weeks. The third compression episode occurred three years later, lasting five minutes, with full recovery within two minutes. This study focuses on the injury of peripheral nerves, including the radial, axillary, and femoral nerves, namely, acute compression neuropathy induced by Japanese RB. Because the radial nerve is the most frequently injured structure, the findings underscore the significance of recognizing the anatomical course of the radial nerve, particularly its position posteriorly at the distal deltoid tuberosity level, as a means of preventing nerve injury in this region. This knowledge is particularly crucial for individuals engaged in the practice of RB, emphasizing the importance of taking precautions to avoid potential nerve damage.

Dynamic model of upper extremity and its application: a systematic review

Dynamics models are widely used in analyzing kinematics and kinetics analysis. Dynamic modeling and simulation can be useful in estimating the torques/forces produced in the limb during various motions, as well as any potential dangers. The aim of this research is to examine the method that is preferable in analyzing the dynamic model of the upper extremity and its application. Several methods have been identified and widely used in analyzing the dynamic model of the upper extremity such as Kane’s method, Lagrange method, optimization method, regression method and many more. Kane's approach, on the other hand, is most commonly used to analyze3D arm segments due to its advantages which is a vector-based approach. The Lagrange approach is suitable to use when the potential and kinetic energy of a system could be easily identified. Meanwhile, most of the researchers used statistical analysis to verify their model and calculation. However, it could be difficult to replicate the simulation work of others because some were not publicly available. Thus, it was recommended to choose a reference from prior studies that will serve as guidance for researchers to solve relevant issues in this field.