Static Body Research Articles

Retarded Green’s function of a Vainshtein system and Galileon waves

Motivated by the desire to test modified gravity theories exhibiting the Vainshtein mechanism, we solve in various physically relevant limits, the retarded Galileon Green's function (for the cubic theory) about a background sourced by a massive spherically symmetric static body. The static limit of our result will aid us, in a forthcoming paper, in understanding the impact of Galileon fields on the problem of motion in the solar system. In this paper, we employ this retarded Green's function to investigate the emission of Galileon radiation generated by the motion of matter lying deep within the Vainshtein radius ${r}_{v}$ of the central object: acoustic waves vibrating on its surface, and the motion of compact bodies gravitationally bound to it. If $\ensuremath{\lambda}$ is the typical wavelength of the emitted radiation, and ${r}_{0}$ is the typical distance of the source from the central mass, with ${r}_{0}\ensuremath{\ll}{r}_{v}$, then, compared to its noninteracting massless scalar counterpart, we find that the Galileon radiation rate is suppressed by the ratio $({r}_{v}/\ensuremath{\lambda}{)}^{\ensuremath{-}3/2}$ at the monopole and dipole orders at high frequencies ${r}_{v}/\ensuremath{\lambda}\ensuremath{\gg}1$. However, at high enough multipole order, the radiation rate is enhanced by powers of ${r}_{v}/{r}_{0}$. At low frequencies ${r}_{v}/\ensuremath{\lambda}\ensuremath{\ll}1$, and when the motion is nonrelativistic, Galileon waves yield a comparable rate for the monopole and dipole terms, and are amplified by powers of the ratio ${r}_{v}/{r}_{0}$ for the higher multipoles.

The Impact of Thermal Modeling on Limiting RF-EMF

The paper quantitatively assesses the relationship between specific energy absorption rates (SAR) of radio frequency (RF) electromagnetic fields (EMF) and resulting intracorporal tissue temperature changes (ΔT) at whole body exposure of a small person to resonant RF EMF. Applied thermal modeling allowed accounting also for dynamic thermoregulatory responses. As expected from physical laws the correlation of all local SAR values and ΔT data was fairly good. However, at local level SAR proved to be only weakly associated with ΔT. Even if averaged, over any 10 g tissue the ratio ΔT10g/SAR10g still varied by almost two orders of magnitudes. Blood perfusion was found to play a major role in affecting local temperature changes and caused even net cooling. The results demonstrate that local SAR is a poor surrogate for local temperature change, and that conventional static thermal modeling underestimates body core temperature. Results demonstrated that recommended reference levels of RF EMF fail to reliably prevent from exceeding yet legally binding basic restrictions not only with regard to whole-body SAR but also with regard to whole-body temperature rise (ΔT). Consequently, from a legal point of view general presumption of conformity is no longer justified. While thermal basic restrictions were exceeded if related to the whole-body averaged value, compliance could not be excluded with regard to body-core related values. Further results might allow improving EMF limiting in terms of relating it more closely to the basic health-relevant parameter which is tissue temperature change.

(99m)tc-Ubiquicidin [29-41], a Promising Radiopharmaceutical to Differentiate Orthopedic Implant Infections from Sterile Inflammation.

Ubiquicidin (UBI) [29-41] is a synthetic cationic antimicrobial peptide that preferentially binds to bacterial cell membrane at the site of infection. We aimed to assess diagnostic value of (99m)Tc-UBI [29-41] as a radiopharmaceutical in differentiation of bacterial infection from sterile inflammation in suspected orthopedic implants. Nine patients suspected for orthopedic implant infection, all males with the mean age of 41.6 ± 20.9 years, were studied. A dose of 10 MBq/Kg (range : 555-740 MBq) (99m)Tc-UBI [29-41] was injected intravenously. A dynamic study followed by static whole body imaging at 30, 60 and 120 min post-radiotracer injection was acquired. Periprosthetic tissue culture was considered the closest test to a gold standard for diagnosing infections and scintigraphic scans were categorized as true- or false-positive and true- or false-negative, considering the bacterial culture as the gold standard. No adverse reaction was observed during or after the radiotracer injection days. There were five true positive, four true negative and no false positive and false negative scans. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were all calculated as 100%. We found a high diagnostic accuracy for (99m)Tc-UBI [29-41] scintigraphy in differentiation of bacterial infection from sterile inflammation in suspected orthopedic implants. Therefore, (99m)Tc-UBI [29-41] scintigraphy might be potentially recommended as a safe and promising imaging modality in these settings. However, further studies on a larger number of patients and different pathologies are still needed.

Pointing hand stimuli induce spatial compatibility effects and effector priming.

The present study investigated the automatic influence of perceiving a picture that indicates other’s action on one’s own task performance in terms of spatial compatibility and effector priming. Participants pressed left and right buttons with their left and right hands respectively, depending on the color of a central dot target. Preceding the target, a left or right hand stimulus (pointing either to the left or right with the index or little finger) was presented. In Experiment 1, with brief presentation of the pointing hand, a spatial compatibility effect was observed: responses were faster when the direction of the pointed finger and the response position were spatially congruent than when incongruent. The spatial compatibility effect was larger for the pointing index finger stimulus compared to the pointing little finger stimulus. Experiment 2 employed longer duration of the pointing hand stimuli. In addition to the spatial compatibility effect for the pointing index finger, the effector priming effect was observed: responses were faster when the anatomical left/right identity of the pointing and response hands matched than when the pointing and response hands differed in left/right identity. The results indicate that with sufficient processing time, both spatial/symbolic and anatomical features of a static body part implying another’s action simultaneously influence different aspects of the perceiver’s own action. Hierarchical coding, according to which an anatomical code is used only when a spatial code is unavailable, may not be applicable if stimuli as well as responses contain anatomical features.

Simulation of the heat exchange between the supersonic flow and the stationary body in a gas centrifuge

We have made comparative calculations of the heat exchange in the subpersonic flow of gaseous UF6 around the stationary cylindrical body inside the rotating rotor of the gas centrifuge. It has been revealed that the integral heat flux from the gas to the body calculated with the use of the ANSYS-CFX program complex from the viewpoint of the continuum model is much smaller than the heat flow calculated by the Monte Carlo method of direct statistical simulation. Estimates show that under the conditions being considered the boundary layer on the surface of the body has no time to be formed and has a thickness of the order of the mean free path of the gas molecules and, therefore, the use of the methods of continuum mechanics in this region is incorrect. On the contrary, the method of direct statistical simulation permits taking into account the interaction of gas molecules directly with the surface of the streamline body and obtaining more correct results.

Preparation of 131I-Pyrimethamine and evaluation for scintigraphy of experimentally Toxoplasma gondii-infected rats

We aimed to assess the ability of 131I-Pyrimethamine scintigraphy to detect the lesions of Toxoplasma gondii infection. An experimental model of toxoplasmosis was developed. The presence of toxoplasmosis was confirmed 60 days after implantation. Pyrimethamine was radioiodinated with I-131. The radioligand was validated by the requisite quality control tests to check its radiolabeling efficiency, in vitro stability and radiochemical purity etc. 131I-Pyrimethamine (specific activity: 7.08 MBq/µmol) was injected intravenously into the tail vein of the control and infected rats. Static whole body images of the rats were acquired under the gamma camera at 5 min, 45 min, 2 h, 6 h, and 24 h following the intravenous administration of the radioactivity (3.7 MBq/rat). Then the scintigraphic data were analyzed both visually and semiquantitatively. Regions of interest (ROIs) were drawn over the organs (thyroid, stomach, liver, bladder, and soft tissues) to calculate the ratios of the radiotracer in infected vs. control rats. The mean ratio of radiotracer in infected/control rats in the liver and diaphragm was over 1 at 45 min which persisted till 24 h. In conclusion, 131I-Pyrimethamine may be useful agent for diagnosis toxoplasmosis especially involving liver and diaphragm, needs further preclinical validation before being extended for use in clinical applications.

Trade in Goods Under the EU–Korea FTA: Market Access and Regulatory Measures

This chapter deals with the rules on trade in goods in the EU-Korea Free Trade Agreement. It is organized, as follows. First, the rules on market access, that is, the EU-Korea FTA provisions related to import measures applicable at the border, will be delineated and analyzed. Subsequently, aspects of one of the most innovative parts of the agreement will be examined in detail: the section containing rules on domestic regulation, in particular, on technical regulations and standards. This paper shows two sides of the EU–Korea FTA. On the one hand, it is a very traditional trade agreement, largely based on existing WTO provisions. This is particularly the case in those parts of the agreement concerning border measures. On the other hand, in particular, concerning the sector-specific rules on technical barriers to trade, the agreement is quite innovative and breaks new grounds, with respect to the regulation of domestic instruments.Moreover, the Agreement is, to a large extent, a ‘living instrument’. Many of the remaining lacunae in the field of domestic regulation must be dealt with in the future, through cooperation and consultations within the different committees and working groups. This is the Agreement’s approach to tackle its endogenous incompleteness, which is inherent in any trade agreement. From this angle, the EU–Korea FTA may not only be understood as a static body of rules, but also as a framework for collaboration that helps to find prompt and appropriate responses to changes in real-world conditions, thus facilitating trade relations between the parties in the long run.

S2-3: Double Dissociation between the Extrastriate Body Area and the Posterior Superior Temporal Sulcus during Biological Motion Perception: Converging Evidence from TMS and fMRI

Our brains engage numerous regions when exposed to biological motion, with the posterior superior temporal sulcus (pSTS) being the primary locus. The exact roles of hMT+ and the extrastriate body area (EBA) remain unclear. Here, we set out to determine the specific roles of pSTS and EBA during biological motion perception, focusing on walker orientation and walking direction. To obtain converging evidence, we conducted separate TMS and fMRI experiments within the same subjects (N = 12). Two separate tasks were used in the TMS study: walker orientation probing form processing and walking direction probing motion/sequence processing. Task performance was compared before and after applying repetitive offline TMS (1 Hz) over EBA and pSTS (based on fMRI-guided stereotaxy). In the fMRI study, EBA and pSTS were mapped in separate scans using standard localizers. Subsequently, runs with point-light walkers were subjected to MVPA, determining the amount of static (orientation) and dynamic (direction) information present within EBA and pSTS. Both TMS and MVPA revealed a strong double dissociation between inferred functions of EBA and pSTS. Disrupting EBA impaired performance on the walker orientation task, while leaving walking direction performance intact. In contrast, disruption of pSTS processing resulted in the opposite effect (p < .001). Similarly, EBA BOLD response revealed significant walker orientation information and no walking direction information, while (again) pSTS BOLD response displayed the opposite pattern (p < .005). We provide converging and causative evidence that dissociates EBA (static body processing) from pSTS (dynamic body sequence processing) during action perception.

Changes in the range of lumbar flexion during cyclic stooping

Previously, responses to stooping or static upper body flexion have been evaluated by quantifying the changes in the range of lumbar flexion after a bout of stooping with restricted and controlled posture conditions. The current study was aimed to confirm the same with unrestricted posture conditions that resembled work-related postures. Twenty two subjects performed stooping work tasks for 6 minutes with intermediate short breaks, followed by a 6-min upright standing recovery period. Time-dependent changes in the range of lumbar flexion were evaluated by measuring peak lumbar flexion angle in full flexion trials and stooping postures before, during and after the stooping period. Results found a significant increase (p&lt;0.05) in the peak lumbar flexion angle after stooping, and the increased range of lumbar flexion did not return to its pre-stooping level after the recovery period. Short breaks during stooping moderated the increase in the flexion range, resulting in a smaller increase in the flexion range compared to what static and controlled full flexion postures have produced in previous research.

Designing with Users: A case study for design of dental workspace

Dental professionals are prone to musculoskeletal disorders and occupational health problems due to the extreme static body postures and use of repetitive hand and wrist movements. This project researched dental work practices and environments to learn about seating needs, tools and the environment that will help maintain good working posture and offer maximum body support during times of repetitive motion and hyperextension. The project also designed new tools that allow for dental work in a neutral posture; a new chair that supports the upper body during dental work; and a customizable work environment for the dental professionals.

Orbital effects of Lorentz-violating standard model extension gravitomagnetism around a static body: a sensitivity analysis

We analytically work out the long-term rates of the change of the six osculating Keplerian orbital elements of a test particle acted upon by the Lorentz-violating gravitomagnetic acceleration due to a static body, as predicted by the standard model extension. We neither restrict to any specific spatial orientation for the symmetry-violating vector nor make a priori simplifying assumptions concerning the orbital configuration of the perturbed test particle. Thus, our results are quite general, and can be applied for sensitivity analyses to a variety of specific astronomical and astrophysical scenarios. We find that, apart from the semimajor axis a, all the other orbital elements undergo non-vanishing secular variations. By comparing our results to the latest determinations of the supplementary advances of the perihelia of some planets of the solar system, we preliminarily obtain sx = (0.9 ± 1.5) × 10−8, sy = ( − 4 ± 6) × 10−9 and sz = (0.3 ± 1) × 10−9. Bounds from the terrestrial LAGEOS and LAGEOS II satellites are of the order of s ∼ 10−3–10−4.

MRI‐related static magnetic stray fields and postural body sway: A double‐blind randomized crossover study

We assessed postural body sway performance after exposure to movement induced time-varying magnetic fields in the static magnetic stray field in front of a 7 Tesla (T) magnetic resonance imaging scanner. Using a double blind randomized crossover design, 30 healthy volunteers performed two balance tasks (i.e., standing with eyes closed and feet in parallel and then in tandem position) after standardized head movements in a sham, low exposure (on average 0.24 T static magnetic stray field and 0.49 T·s(-1) time-varying magnetic field) and high exposure condition (0.37 T and 0.70 T·s(-1)). Personal exposure to static magnetic stray fields and time-varying magnetic fields was measured with a personal dosimeter. Postural body sway was expressed in sway path, area, and velocity. Mixed-effects model regression analysis showed that postural body sway in the parallel task was negatively affected (P < 0.05) by exposure on all three measures. The tandem task revealed the same trend, but did not reach statistical significance. Further studies are needed to investigate the possibility of independent or synergetic effects of static magnetic stray field and time-varying magnetic field exposure. In addition, practical safety implications of these findings, e.g., for surgeons and others working near magnetic resonance imaging scanners need to be investigated.

Double dissociation between the extrastriate body area and the posterior superior temporal sulcus during biological motion perception: converging evidence from TMS and fMRI

Our brains engage numerous regions when exposed to biological motion, with the posterior superior temporal sulcus (pSTS) being the primary locus. However, most of the supporting evidence stems from studies that contrasted intact with position-scrambled point-light animations. This approach leaves unclear the exact functional role of not only this region, but also of other co-activated regions, including hMT+ and the extrastriate body area (EBA). Here, we set out to determine the specific roles of pSTS and EBA during biological motion perception, focusing on walker orientation and walking direction. To obtain converging evidence, we conducted separate TMS and fMRI experiments within the same subjects (N=12). Two separate tasks were used in the TMS study: walker orientation and walking direction. In the orientation task, subjects identified the facing direction of a "point-light" walker (left vs. right). In the direction task, subjects identified walking direction (forward vs. backward). Task performance was compared before and after applying repetitive offline TMS (1Hz) over EBA and pSTS (based on fMRI-guided stereotaxy). In the fMRI study, EBA and pSTS were mapped in separate scans using standard localizers. Subsequently, runs with point-light walkers (2 facing orientations * 2 walking directions) were subjected to Multi-Voxel Pattern Analysis, determining the amount of static (orientation) and dynamic (direction) information present within EBA and pSTS. Both TMS and MVPA revealed a strong double dissociation between inferred functions of EBA and pSTS. Disrupting EBA impaired performance on the walker orientation task, while leaving walking direction performance intact. In contrast, disruption of pSTS processing resulted in the opposite effect (p<.001). Similarly, EBA BOLD response revealed significant walker orientation information and no walking direction information, while (again) pSTS BOLD response displayed the opposite pattern (p<.005). We provide converging and causative evidence that dissociates EBA (static body processing) from pSTS (dynamic body sequence processing) during action perception. Meeting abstract presented at VSS 2012

Vliv intervenčního programu poweryoga na změny úrovně statické rovnováhy a složení těla – BMI

Th is contribution presents the results of a pilot study measuring changes in the levels of static balance and body composition (BMI) brought about by practising the poweryoga programme. Th e 3-month intervention programme was applied to an experimental group of female students at the Faculty of Science of Charles University in Prague. Th e test to ascertain the static balance level measured the time for which the subjects were able to stand on one leg without visual control; the BMI data were obtained from the subjects‘ height-to-weight ratios. Although practised for a short-time only, the intervention programme resulted in positive changes in the static balance level (at a low level of signifi cance due to the small number of subjects involved). BMI changes appeared to be negligible due to the short time and one-sidedness of the intervention. Th e results will be used to modify the motion content of the poweryoga intervention programme within a comprehensive study of the effi ciency of the motion programme and in support of usefulness of this motion activity for female university students.

Motor mapping of implied actions during perception of emotional body language

Perceiving and understanding emotional cues is critical for survival. Using the International Affective Picture System (IAPS) previous TMS studies have found that watching humans in emotional pictures increases motor excitability relative to seeing landscapes or household objects, suggesting that emotional cues may prime the body for action. Here we tested whether motor facilitation to emotional pictures may reflect the simulation of the human motor behavior implied in the pictures occurring independently of its emotional valence. Motor-evoked potentials (MEPs) to single-pulse TMS of the left motor cortex were recorded from hand muscles during observation and categorization of emotional and neutral pictures. In experiment 1 participants watched neutral, positive and negative IAPS stimuli, while in experiment 2, they watched pictures depicting human emotional (joyful, fearful), neutral body movements and neutral static postures. Experiment 1 confirms the increase in excitability for emotional IAPS stimuli found in previous research and shows, however, that more implied motion is perceived in emotional relative to neutral scenes. Experiment 2 shows that motor excitability and implied motion scores for emotional and neutral body actions were comparable and greater than for static body postures. In keeping with embodied simulation theories, motor response to emotional pictures may reflect the simulation of the action implied in the emotional scenes. Action simulation may occur independently of whether the observed implied action carries emotional or neutral meanings. Our study suggests the need of controlling implied motion when exploring motor response to emotional pictures of humans.

Knee joint forces: prediction, measurement, and significance.

Knee forces are highly significant in osteoarthritis and in the survival and function of knee arthroplasty. A large number of studies have attempted to estimate forces around the knee during various activities. Several approaches have been used to relate knee kinematics and external forces to internal joint contact forces, the most popular being inverse dynamics, forward dynamics, and static body analyses. Knee forces have also been measured in vivo after knee arthroplasty, which serves as valuable validation of computational predictions. This review summarizes the results of published studies that measured knee forces for various activities. The efficacy of various methods to alter knee force distribution, such as gait modification, orthotics, walking aids, and custom treadmills are analyzed. Current gaps in our knowledge are identified and directions for future research in this area are outlined.

A Review of the Ergonomic Issues in the Laparoscopic Operating Room

This review paper discusses the ergonomic challenges associated with laparoscopy in the operating room (OR) and summarizes the practical ergonomic solutions. The literature search was conducted in the fields of laparoscopy and applied ergonomics. Findings indicated that laparoscopic OR staff (surgeons, perioperative nurses and technicians) commonly experienced physical and mental ergonomic risks while working in prolonged static and awkward body positions. This study highlighted the need for more ergonomic interventions in OR environment in order to improve the efficiency of laparoscopy. Ergonomic solutions included utilizing adjustable equipment, placing computer peripherals in optimal locations, providing ergonomic instruments, and improving communication. Understanding the job‐ or task‐related ergonomic risks and hazards could help identify intervention requirements to meet the challenges associated with increased dependency on advanced high technology in the OR.

Anthropometric Database for the Learning Environment of High School and University Students

This paper presents an anthropometric database of high school and university students from Kuala Lumpur, Malaysia. Forty-one high school participants (21 males and 20 females), 13–17 years old, and 143 university students (74 males and 69 females) took part in the study. Twenty-one static body dimensions were measured. The greatest mean differences in the anthropometric data between male and female high school students were found in the sitting elbow height. In addition, a comparison of anthropometric data of male and female university students showed that data for males and females were significantly different, except for buttock–popliteal length, sitting elbow height and thigh clearance. The primary aim of this study was to develop an anthropo-metric database that could be used as a primary reference in designing products, devices and equipment for ergonomic learning environments.

Study and analysis of occupational risk factors for ergonomic design of construction worksystems

Manual material handling (MMH) is unavoidable because of the nature of jobs or tasks as and man-machine interfaces in a construction worksystem. Data were collected from six strata of workers viz., masons, mason helpers, carpenters, welders, gas cutters and ground-level helpers (259 out of 700 workers) from a construction site of a steel plant located in India to analyze different types of occupational risk factors, such as awkward posture, repetitive movements and others associated with MMH activities to assess their impact on musculoskeletal disorders (MSDs). It is essential that these risk factors are required to be under control through application of ergonomics-based design approaches for construction worksystem. In this context, multinomial logistic regression analyses were used to identify the significant risk factors among the workers. The results shows that masons, mason helpers, carpenters, welders/gas cutters and ground-level helpers are greatly affected by static body posture, type of tools used, excessive stress due to repetition, awkward postures and extreme climate, respectively. Appropriate preventive and corrective measures are suggested for minimization of risks associated with such jobs/tasks to improve health and performance of the workers.

Tactile Perception of Nonpainful Unpleasantness in Relation to Perceived Roughness: Effects of Inter-Element Spacing and Speed of Relative Motion of Rigid 2-D Raised-Dot Patterns at Two Body Loci

Rigid surfaces consisting of spatially jittered 2-D raised-dot patterns with different inter-element spacings were moved back and forth across the skin at three different speeds (10-fold range). Within each psychophysical experiment, participants numerically estimated the perceived magnitude of either unpleasantness (nonpainful) or roughness of 2-D raised-dot surfaces applied to two stationary body sites (experiment 1: fingers; experiment 2: forearm). The psychophysical functions for the two types of perceptual judgment were highly similar at both body loci; more specifically, the perceived magnitude of unpleasantness and roughness both increased monotonically as a power function of increasing inter-element spacing, with the rate of growth declining at the upper end of the continuum. These results suggest that inter-element spacing is a critical determinant of the perceived magnitude of unpleasantness (nonpainful), as well as of roughness. Each perceptual judgment also increased as a function of increasing relative speed at both body loci. However, the magnitude of this effect was significantly greater for perceived unpleasantness than for perceived roughness; conversely, the speed effect was significantly greater on the forearm than on the fingers. Several possible explanations for these findings are considered.