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To study the performance of the main windshield of a commercial aircraft that has been verified to be airworthy by bird-strike tests against unmanned aerial vehicle (UAV) impact at high-speed, a typical light UAV with various possible flight postures and the main windshield of a commercial aircraft are considered. The transient impact responses at critical moments, energy change and contact force of a multi-layer windshield impacted by a UAV with different postures are investigated using a simulation method based on the models verified by the high-speed impact test between the whole UAV and the full-size nose. This study shows that the flight posture of the UAV has a significant effect on the damage to the windshield. When the abdomen of a typical light UAV maintains a posture parallel to the plane of the windshield, the high-speed impact would cause catastrophic damage to the windshield and no longer be airworthy. Simultaneously, the damage to the aircraft windshield caused by UAV collision is far more serious than that caused by bird strikes under similar collision conditions. The mass-concentrated components of the UAV and their high-hardness characteristics are the main factors of affecting multi-layer glass of windshield damage. The degree of damage to the windshield is positively related to the absorbed energy rather than the impact contact force. In this study, the impact simulation results between the windshield and UAV with different flight postures are verified qualitatively by testing, which provides a rational understanding and technical pre-research support for emerging and increasingly frequent potential safety hazards in air transport practice.
An animal's welfare state is intrinsically linked to its affective state. Evidence suggests that sentient, conscious animals can experience a range of affective states, such as pain, fear or boredom as well as positive affects like joy, curiosity, satiation or lust. In the behavioural assessment of animal welfare, there is increasing recognition that it is not simply which behaviours an animal engages in but also the quality of its movement. Kinematics is an approach which is being more widely applied to the behavioural assessment of animal welfare. Kinematics is a field of mechanics that describes the movement of points on a body by defining these points in a coordinate system and precisely tracking how they change in terms of space and time. A major opportunity exists for using kinematic technology to inform our understanding of the emotional state of animals. This review argues that kinematics is a useful methodology for identifying and characterising movement indicative of an animal's affective state. It demonstrates that kinematics: i) appears useful in detecting subtleties in the expression of affective states; ii) could be used in conjunction with, and add extra information to, affective tests (for example, an approach/avoidance paradigm); and iii) could potentially, eventually, be developed into an automated affective state detection system for improving the welfare of animals used in research or production. Furthering our knowledge of animal affective states using kinematics requires engagement from many areas of science outside of animal welfare, such as sports science, computer science, engineering and psychology.
Work-related musculoskeletal disorders in ENT surgeons are common and detrimental, yet few are aware of preventative measures. We evaluate the evidence for interventions to prevent work-related musculoskeletal disorders in ENT surgeons.
Method
A systematic search of databases up to 8 June 2021 was performed using Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines and predetermined inclusion criteria.
Results
Seven prospective cohort studies and 2 case series were identified (51 participants). Interventions included novel equipment (n = 3), patient positioning (n = 2), clinician positioning (n = 3) and operative technique (n = 1). Five studies reported Rapid Upper Limb Assessment scores as outcome measures of strain. Strain decreased when adopting a favourable operating posture, using a supportive chair and keeping patients supine for clinic procedures.
Conclusion
A small number of low-quality studies were identified. Modifiable risk factors exist, and ergonomic education may help prevent work-related musculoskeletal disorders. Further studies with longer term follow up are required.
Lameness is an important economic problem in the dairy sector, resulting in production loss and reduced welfare of dairy cows. Given the modern-day expansion of dairy herds, a tool to automatically detect lameness in real-time can therefore create added value for the farmer. The challenge in developing camera-based tools is that one system has to work for all the animals on the farm despite each animal having its own individual lameness response. Individualising these systems based on animal-level historical data is a way to achieve accurate monitoring on farm scale. The goal of this study is to optimise a lameness monitoring algorithm based on back posture values derived from a camera for individual cows by tuning the deviation thresholds and the quantity of the historical data being used. Back posture values from a sample of 209 Holstein Friesian cows in a large herd of over 2000 cows were collected during 15 months on a commercial dairy farm in Sweden. A historical data set of back posture values was generated for each cow to calculate an individual healthy reference per cow. For a gold standard reference, manual scoring of lameness based on the Sprecher scale was carried out weekly by a single skilled observer during the final 6 weeks of data collection. Using an individual threshold, deviations from the healthy reference were identified with a specificity of 82.3%, a sensitivity of 79%, an accuracy of 82%, and a precision of 36.1% when the length of the healthy reference window was not limited. When the length of the healthy reference window was varied between 30 and 250 days, it was observed that algorithm performance was maximised with a reference window of 200 days. This paper presents a high-performing lameness detection system and demonstrates the importance of the historical window length for healthy reference calculation in order to ensure the use of meaningful historical data in deviation detection algorithms.
Blood pressure (BP) tracks from childhood to adulthood, and early BP trajectories predict cardiovascular disease risk later in life. Excess postnatal weight gain is associated with vascular changes early in life. However, to what extent it is associated with children’s BP is largely unknown. In 853 healthy 5-year-old children of the Wheezing-Illnesses-Study-Leidsche-Rijn (WHISTLER) birth cohort, systolic (SBP) and diastolic BP (DBP) were measured, and z scores of individual weight gain rates adjusted for length gain rates were calculated using at least two weight and length measurements from birth until 3 months of age. Linear regression analyses were conducted to investigate the association between weight gain rates adjusted for length gain rates and BP adjusted for sex and ethnicity. Each standard deviation increase in weight gain rates adjusted for length gain rates was associated with 0.9 mmHg (95% CI 0.3, 1.5) higher sitting SBP after adjustment for confounders. Particularly in children in the lowest birth size decile, high excess weight gain was associated with higher sitting SBP values compared to children with low weight gain rates adjusted for length gain rates. BMI and visceral adipose tissue partly explained the association between excess weight gain and sitting SBP (β 0.5 mmHg, 95% CI −0.3, 1.3). Weight gain rates adjusted for length gain rates were not associated with supine SBP or DBP. Children with excess weight gain, properly adjusted for length gain, in the first three months of life, particularly those with a small birth size, showed higher sitting systolic BP at the age of 5 years.
The ablation of advanced head and neck cancer often results in large three-dimensional defects that require free tissue transfer to optimally address functional and cosmetic issues. The subscapular system is a highly versatile donor site for flaps used for head and neck reconstruction. Traditional methods of harvesting subscapular flaps require repositioning and re-preparing, which significantly increases the operative time and prevents simultaneous harvesting of the flap.
Method:
This paper presents our experience of a single-stage ‘sit and tilt’ technique, which provides a convenient method for harvesting subscapular system free flaps without significant repositioning.
Results and conclusion:
This technique was used for a variety of head and neck defects, and body habitus did not seem to affect free tissue harvesting. It is hoped that utilisation of this preparation and harvesting technique will make head and neck surgeons more willing to take advantage of the subscapular system.
This paper focusses on a set of anthropomorphic figurines. It suggests that realistic human proportion and canonical body posture were pursued in the carving of these objects as a means of expressing ideology, in a context of diversified forms of manipulation of bodies in funerary practices. It is argued that, against a background of predominantly schematic art, the more realistic and canonical anthropomorphic representation of the human body was used to communicate a set of ideological statements in a more controlled and immediate way, in a period of ontological and cosmological transition.
Temporo-spatial observation of the leg could provide important information about the general condition of an animal, especially for those such as sheep and other free-ranging farm animals that can be difficult to access. Tri-axial accelerometers are capable of collecting vast amounts of data for locomotion and posture observations; however, interpretation and optimization of these data records remain a challenge. The aim of the present study was to introduce an optimized method for gait (walking, trotting and galloping) and posture (standing and lying) discrimination, using the acceleration values recorded by a tri-axial accelerometer mounted on the hind leg of sheep. The acceleration values recorded on the vertical and horizontal axes, as well as the total acceleration values were categorized. The relative frequencies of the acceleration categories (RFACs) were calculated in 3-s epochs. Reliable RFACs for gait and posture discrimination were identified with discriminant function and canonical analyses. Post hoc predictions for the two axes and total acceleration were conducted, using classification functions and classification scores for each epoch. Mahalanobis distances were used to determine the level of accuracy of the method. The highest discriminatory power for gait discrimination yielded four RFACs on the vertical axis, and five RFACs each on the horizontal axis and total acceleration vector. Classification functions showed the highest accuracy for walking and galloping. The highest total accuracy on the vertical and horizontal axes were 90% and 91%, respectively. Regarding posture discrimination, the vertical axis exhibited the highest discriminatory power, with values of RFAC (0, 1]=99.95% for standing; and RFAC (−1, 0]=99.50% for lying. The horizontal axis showed strong discrimination for the lying side of the animal, as values were in the acceleration category of (0, 1] for lying on the left side and (−1, 0] on the right side. The algorithm developed by the method employed in the present study facilitates differentiation of the various types of gait and posture in animals from fewer data records, and produces the most reliable acceleration values from only one axis within a short time frame. The present study introduces an optimized method by which the tri-axial accelerometer can be used in gait and posture discrimination in sheep as an animal model.
For design using digital human models, human anthropometry data are required as input and are extracted from measurements. There is inherent error associated with these measurements which impacts the output of the simulation. Current techniques in digital human modeling applications primarily employ deterministic methods which are not well suited for handling variability in anthropometric measurement. An alternative to deterministic methods is probabilistic/sensitivity analysis. This study presents a probabilistic sensitivity approach to gain insights into how uncertainty in anthropometric measurements can affect the results of a digital human model with the specific application of vehicle-related reach tasks. Sensitivity levels are found to determine the importance of variability in each joint angle and link length to the final reach. A55-degree of freedom (DOF) digital human model is introduced to demonstrate the sensitivity approach for reach tasks. Seven right-hand reach target points and two left-hand reach target points (creating a total of 14 reach tasks) within a vehicle are used to compare the sensitivities in the joint angles and link lengths resulting from measurement uncertainty. The results show that the importance of each joint angle or link length is dependent on the characteristics of the reach task and sensitivities for joint angles, and link lengths are different for each reach task.
Lameness in sows has an economic impact on pig production and is a major welfare concern. The aim of the present project was to develop methods to evaluate and quantify lameness in breeding sows. Five methods to study lameness were compared between themselves and with visual gait scoring used as a reference: footprint analysis, kinematics, accelerometers, lying-to-standing transition and foot lesion observation. Fifty sows of various parities and stages of gestation were selected using visual gait scoring and distributed into three groups: lame (L), mildly lame (ML) and non-lame (NL). They were then tested using each method. Kinematics showed that L sows had a lower walking speed than NL sows (L: 0.83 ± 0.04, NL: 0.96 ± 0.03 m/s; P < 0.05), a shorter stride length than ML sows (L: 93.0 ± 2.6, ML: 101.2 ± 1.5 cm; P < 0.05) and a longer stance time than ML and NL sows (L: 0.83 ± 0.03, ML: 0.70 ± 0.03, NL: 0.69 ± 0.02 s; P < 0.01). Accelerometer measurements revealed that L sows spent less time standing over a 24-h period (L: 6.3 ± 1.3, ML: 13.7 ± 2.4, NL: 14.5 ± 2.4%; P < 0.01), lay down earlier after feeding (L: 33.4 ± 4.6, ML: 41.7 ± 3.1, NL: 48.6 ± 2.9 min; P < 0.05) and tended to step more often during the hour following feeding (L: 10.1 ± 2.0, ML: 6.1 ± 0.5, NL: 5.4 ± 0.4 step/min standing; P = 0.06) than NL sows, with the ML sows having intermediate values. Visual observation of back posture showed that 64% of L sows had an arched back, compared with only 14% in NL sows (P = 0.02). Finally, footprint analysis and observation of lying-to-standing transition and foot lesions were not successful in detecting significant differences between L, ML and NL sows. In conclusion, several quantitative variables obtained from kinematics and accelerometers proved to be successful in identifying reliable indicators of lameness in sows. Further work is needed to relate these indicators with causes of lameness and to develop methods that can be implemented on the farm.
The object of this study was to evaluate the combined effect of body and facial feedback in adults who had suffered from a severe traumatic brain injury (TBI) to gain some understanding of their difficulties in the regulation of negative emotions. Twenty-four participants with TBI and 28 control participants adopted facial expressions and body postures according to specific instructions and maintained these positions for 10 s. Expressions and postures entailed anger, sadness, and happiness as well as a neutral (baseline) condition. After each expression/posture manipulation, participants evaluated their subjective emotional state (including cheerfulness, sadness, and irritation). TBI participants were globally less responsive to the effects of body and facial feedback than control participants, F(1,50) = 5.89, p = .02, η2 = .11. More interestingly, the TBI group differed from the Control group across emotions, F(8,400) = 2.51, p = .01, η2 = .05. Specifically, participants with TBI were responsive to happy but not to negative expression/posture manipulations whereas control participants were responsive to happy, angry, and sad expression/posture manipulations. In conclusion, TBI appears to impair the ability to recognize both the physical configuration of a negative emotion and its associated subjective feeling. (JINS, 2013, 19, 1–13)
Normal balance relies on three sensory inputs: vision, proprioception and the peripheral vestibular system. This study assessed hearing change and postural control in normal subjects.
Materials and methods:
Postural control in 20 normal volunteers was assessed using a Nintendo Wii gaming console and balance board. Each subject was tested standing upright for 30 seconds in a clinic room and a soundproof room with their eyes open, eyes closed, whilst standing on and off foam, and with and without ear defenders.
Results:
There was significantly more postural sway in the following subjects: those standing with their eyes closed vs those with eyes open (normal room, p = 0.0002; soundproof room, p = 0.0164); those standing on foam with eyes open vs those standing normally with eyes open (in both rooms; p < 0.05); those standing with eyes open in a soundproof room vs a normal room (p = 0.0164); and those standing on foam in a soundproof room with eyes open and wearing ear defenders vs those in the same circumstances but without ear defenders.
Conclusion:
Our results suggest that this method provides a simple, inexpensive tool for assessing static postural control. Whilst it is recognised that visual input and proprioception play a central role in maintaining posture, our findings suggest that ambient sound and hearing may also have a significant influence.
The premise explored in this target article is that the function of the cerebellum is best understood in terms of the operation it performs across its structurally homogeneous subdivisions. The functional heterogeneity sometimes ascribed to these different regions reflects the multiplicity of functions subserved by the central targets receiving the outputs of different cerebellar regions. Recent studies from our own laboratory and others suggest that the functional unit of the cerebellum is the sagittal zone. It is hypothesized that the climbing fiber system produces a short-lasting modification in the gain of Purkinje cell responses to its other principal afferent input, the mossy fiber-granule cell-parallel fiber system. Because the climbing fiber inputs to sagittally aligned Purkinje cells can be activated under functionally specific conditions, these afferents could select populations of Purkinje neurons that would be most highly modulated by mossy fiber inputs responding to the same conditions. These operations may be critical for the on-line integration of inputs characterizing external target space with features of the intended movement, proprioceptive and kinesthetic cues, and the body image.
The persistence of many contrasting notions of climbing fiber function after years of investigation testifies that the issue of climbing fiber contributions to cerebellar transactions is still unresolved. The proposed capabilities of the climbing fibers cover an impressive spectrum. For many researchers, the climbing fibers signal errors in motor performance, either in the conventional manner of frequency modulation or as a single announcement of an “unexpected event”. More controversial is the effect of these signals on the simple spike modulation of Purkinje cells. In some hands, they lead to a long-term depression of the strength of parallel fiber synapses, while, in other hands, they lead to a short-lasting enhancement of the responsiveness of Purkinje cells to mossy fiber inputs or contribute to the often-seen reciprocal relation between complex and simple spike modulation. For still other investigators, the climbing fibers serve internal timing functions through their capacity for synchronous and rhythmic firing. The above viewpoints are presented in the spirit of trying to reach some consensus about climbing fiber function. Each point of view is introduced by summarizing first the key observations made by the respective proponents; then the issues of short-lasting enhancement, reciprocity between complex and simple spikes, and synchrony and rhythmicity are addressed in the context of the visual climbing fiber system of the vestibulocerebellum.
A scheme for understanding the organization of human postural movements is developed in the format of a position paper. The structural characteristics of the body and the geometry of muscular actions are incorporated into a three-dimensional graphical representation of human movement mechanics in the sagittal plane. A series of neural organizational hypotheses limit a theoretically infinite number of combinations of muscle contractions and associated movement trajectories for performing postural corrections: (1) Controls are organized to use the minimum number of muscles; (2) frequently performed movements are organized to require a minimum of neural decision-making.
These hypotheses lead to the prediction that postural movements are composed of muscle contractile strategies derived from a limited set of distinct contractile patterns. The imposition of two mechanical constraints related to the configuration of support and to requirements for body stability with respect to gravity predict the conditions under which individual movement strategies will be deployed.
A complementary organizational scheme for the senses is developed. We show that organization of postural movements into combinations of distinct strategies simplifies the interpretation of sensory inputs. The fine-tuning of movement strategies can be accomplished by breaking down the complex array of feedback information into a series of scalar quantities related to the parameters of the movement strategies. For example, the magnitude, aim, and curvature of the movement trajectory generated by an individual strategy can be adjusted independently.
The second half of the report compares theoretical predictions with a series of actual experimental observations on normal subjects and patients with known sensory and motor disorders. Actual postural movements conform to theoretical predictions about the composition of individual movement strategies and the conditions under which each strategy is used. Observations on patients suggest how breakdowns in individual steps within the logical process of organization can lead to specific movement abnormalities.
Discussion focuses on the areas needing further experimentation and on the implications of the proposed organizational scheme. We conclude that although our organizational scheme is not new in demonstrating the need for simplifying the neural control of movement, it is perhaps original in imposing discrete logical control upon a continuous mechanical system. The attraction of the scheme is that it provides a framework compatible with both mechanical and physiological information and amenable to experimental testing.
Redundancy of the motor control system is an important feature that gives the central control structures options for solving everyday motor problems. The choice of particular control patterns is based on priorities (coordinative rules) that are presently unknown. Motor patterns observed in unimpaired young adults reflect these priorities. We hypothesize that under certain atypical conditions, which may include disorders in perception of the environment and in decision making, structural or biochemical changes within the central nervous system (CNS), and/or structural changes of the effectors, the central nervous system may reconsider its priorities. A new set of priorities will reflect the current state of the system and may lead to different patterns of voluntary movement. Under such conditions, changed motor patterns should be considered not pathological but rather adaptive to a primary disorder and may even be viewed as optimal for a given state of the system of movement production. Therapeutic approaches should not be directed toward restoring the motor patterns to as close to “normal” as possible but rather toward resolving the original underlying problem. We illustrate this approach using, as examples, movements in amputees, in patients with Parkinson's disease, in patients with dystonia, and in persons with Down syndrome.
The tonic postural system controls the equilibrium of posture when the body is completely at rest and when it is moving. It is a complicated mechanism that can call into action a variety of modalities including the assistance of the feet, the skin, the eyes, the masticatory system, the Central Nervous System and the efferent muscles, with all elements working reciprocally. Orthodontists should make a postural assessment before undertaking any treatment. If problems are found they should be dealt with by a multi-disciplinary team. But in every case orthodontists should be aware that their efforts have an effect on posture and can modify the corporal schema of the patient. Orthodontists should pay special attention to patients with scoliosis or any deformity of the spinal column.
Without realizing it, orthodontists may find themselves treating patients suffering from cranio-mandibular disorders, who may be adults, but not necessarily. Both young children and adolescents can also have these problems. Orthodontists often fall into the trap of not recognizing these disorders especially when the clinical signs are discreet or even non-existent. In order to save orthodontists from encountering unpleasant post-treatment surprises, we present in this paper a review of some of the indications of the etiology of craniomandibular dysfunction, how to diagnose it, and the importance of its major clinical signs that can be a great help to them in achieving a keener state of vigilance in this regard throughout orthodontic therapy.
Many derangements in the cranio-mandibular relationship can contribute to the etiopathogenesis of tempero-mandibular disorders and postural anomalies. Orthodontists should understand their characteristics in order to prevent their development or correct them if they appear during the course of orthodontic treatment. Occlusal splints for re-positioning the mandible to restore it to a healthy physiological position are an invaluable tool in dealing with this aspect of orthodontic therapy.
The relationship between occlusion and posture has been a continual source of interest to all participants in the delivery of health care. But a certain amount of confusion still beclouds the subject because of the wide diversity of therapeutic approaches designed to deal with it and the weakness of methodological design in the scientific studies that have been published on it to date.
This article addresses the questions raised by that correlation between occlusion and posture as well as the therapeutic implications of a clinical approach integrating treatment of corporal posture into orthodontic care. A review of the literature shows that there is a dearth of reliable experimental data dealing with this subject. The data that is available points to the existence of this correlation and also asserts the prevalence of associations between idiopathic scoliosis and cranio-facial anomalies in adolescents.
The published facts appear to support our clinical impressions and subjective convictions. In order to enlarge our vision to encompass patients as entire human beings instead of compartmentalized biological segments each to be treated by an appropriate specialty it would be helpful if members of the various medical disciplines improved the lines of communication with each other. An equally desirable development would be the establishment of fundamental research and clinical programs that would help to establish causal relationships that would put therapy on evidence based foundation.