Variability In Position Research Articles

Magnetic Resonance Imaging Evaluation of Closed-Mouth TMJ Disc-Condyle Relationship in a Population of Patients Seeking for Temporomandibular Disorders Advice

Objective To characterize the closed-mouth temporomandibular joint (TMJ) disc-condyle relationship in a population of individuals who sought hospital services for temporomandibular disorders (TMD). Methods Two hundred and twenty-four TMJ magnetic resonance images (MRIs) of 112 patients were assessed in all spatial planes to classify disc position with respect to the condyle in a closed-mouth position. Results Disc displacement (DD) was present in 62.1% and superior disc position in 29.9% of the patients. Position could not be determined in 8% of the cases. Among DD, pure anteriorized position was the most common condition (34.4%), with different combined translational and rotational displacements in all the other joints (27.7%). Conclusion There is a wide biological variability in disc position in closed mouth among patients seeking for TMD advice. Getting deeper into the correlation with clinical symptoms is recommended to refine the potential relevance of any diagnostic and management strategies based on the imaging evaluation of TMJ disc position.

Ship Detection via Dilated Rate Search and Attention-Guided Feature Representation

Due to the complexity of scene interference and the variability of ship scale and position, automatic ship detection in remote sensing images makes for challenging research. The existing deep networks rarely design receptive fields that fit the target scale based on training data. Moreover, most of them ignore the effective retention of position information in the feature extraction process, which reduces the contribution of features to subsequent classification. To overcome these limitations, we propose a novel ship detection framework combining the dilated rate selection and attention-guided feature representation strategies, which can efficiently detect ships of different scales under the interference of complex environments such as clouds, sea clutter and mist. Specifically, we present a dilated convolution parameter search strategy to adaptively select the dilated rate for the multi-branch extraction architecture, adaptively obtaining context information of different receptive fields without sacrificing the image resolution. Moreover, to enhance the spatial position information of the feature maps, we calculate the correlation of spatial points from the vertical and horizontal directions and embed it into the channel compression coding process, thus generating the multi-dimensional feature descriptors which are sensitive to direction and position characteristics of ships. Experimental results on the Airbus dataset demonstrate that the proposed method achieves state-of-the-art performance compared with other detection models.

Machine learning methods for sign language recognition: A critical review and analysis

• A comprehensive review of artificial intelligent methods applied in sign language recognition systems. • Bibliometric analysis of research progress and publication pattern in intelligent based sign language recognition. • Overview of feature extraction and sign image segmentation techniques. • The publication trend in intelligent sign language recognition system is consistent with the rapid increase in people affected by hearing disability. Sign language is an essential tool to bridge the communication gap between normal and hearing-impaired people. However, the diversity of over 7000 present-day sign languages with variability in motion position, hand shape, and position of body parts making automatic sign language recognition (ASLR) a complex system. In order to overcome such complexity, researchers are investigating better ways of developing ASLR systems to seek intelligent solutions and have demonstrated remarkable success. This paper aims to analyse the research published on intelligent systems in sign language recognition over the past two decades. A total of 649 publications related to decision support and intelligent systems on sign language recognition (SLR) are extracted from the Scopus database and analysed. The extracted publications are analysed using bibliometric VOSViewer software to (1) obtain the publications temporal and regional distributions, (2) create the cooperation networks between affiliations and authors and identify productive institutions in this context. Moreover, reviews of techniques for vision-based sign language recognition are presented. Various features extraction and classification techniques used in SLR to achieve good results are discussed. The literature review presented in this paper shows the importance of incorporating intelligent solutions into the sign language recognition systems and reveals that perfect intelligent systems for sign language recognition are still an open problem. Overall, it is expected that this study will facilitate knowledge accumulation and creation of intelligent-based SLR and provide readers, researchers, and practitioners a roadmap to guide future direction. Flowchart of publications gathering in Scopus database and the procedure for bibliometric analysis .

An Inexpensive Cardiovascular Flow Simulator for Cardiac Catheterization Procedure Using a Pulmonary Artery Catheter.

Cardiac catheterization associated with central vein cannulation can involve potential thrombotic and infectious complications due to multiple cannulation trials or improper placement. To minimize the risks, medical simulators are used for training. Simulators are also employed to test medical devices such as catheters before performing animal tests because they are more cost-effective and still reveal necessary improvements. However, commercial simulators are expensive, simplified for their purpose, and provide limited access sites. Inexpensive and anatomical cardiovascular simulators with central venous access for cannulation are sparse. Here, we developed an anatomically and physiologically accurate cardiovascular flow simulator to help train medical professionals and test medical devices. Our simulator includes an anatomical right atrium/ventricle, femoral and radial access sites, and considers the variability of arm position. It simulates physiological pulsatile blood flow with a setting for constant flow from 3 to 6 L/min and mimics physiological temperature (37°C). We demonstrated simulation by inserting a catheter into the system at radial/femoral access sites, passing it through the vasculature, and advancing it into the heart. We expect that our simulator can be used as an educational tool for cardiac catheterization as well as a testing tool that will allow for design iteration before moving to animal trials.

Electrical Impedance of Upper Limb Enables Robust Wearable Identity Recognition against Variation in Finger Placement and Environmental Factors.

Most biometric authentication technologies commercialized in various fields mainly rely on acquired images of structural information, such as fingerprints, irises, and faces. However, bio-recognition techniques using these existing physical features are always at risk of template forgery threats, such as fake fingerprints. Due to the risk of theft and duplication, studies have recently been attempted using the internal structure and biological characteristics of the human body, including our previous works on the ratiometric biological impedance feature. However, one may still question its accuracy in real-life use due to the artifacts from sensing position variability and electrode–skin interfacing noise. Moreover, since the finger possesses more severe thermoregulatory vasomotion and large variability in the tissue properties than the core of the body, it is necessary to mitigate the harsh changes occurring at the peripheral extremities of the human body. To address these challenges, we propose a biometric authentication method through robust feature extraction from the upper-limb impedance acquired based on a portable wearable device. In this work, we show that the upper limb impedance features obtained from wearable devices are robust against undesirable factors such as finger placement deviations and day-to-day physiological changes, along with ratiometric impedance features. Overall, our upper-limb impedance-based analysis in a dataset of 1627 measurement from 33 subjects lowered the classification error rate from 22.38% to 4.3% (by a factor of 5), and further down to 2.4% (by a factor of 9) when combined with the ratiometric features.

An ultrasound study of rest position and pre-acoustic articulation in adults and children

The position of the tongue during rest and its relationship to subsequent pre-acoustic speech movements have shed light on speech motor planning. They may find applications in technologies such as silent speech interfaces. Palo [“Measuring pre-speech articulation,” Ph.D. thesis (Queen Margaret University, Edinburgh, 2019)] found that the duration of pre-acoustic speech movements are strongly correlated with acoustic utterance duration, but it remains an open question whether this correlation is modulated by different rest positions. This study investigates variability in rest position among children and adults, and examines whether rest position affects pre-acoustic speech movements and their correlation with acoustic utterance durations. [This work has been supported by a personal grant from The Emil Aaltonen Foundation (Palo) and by NSF Grant No. 1551131 (Lulich).]

Tongue position variability in sustained vowels produced by healthy children and young adults with and without a semi-occluded vocal tract: A pilot study

Speech development is a process by which talkers learn, among other things, to coordinate neuromuscular activations of motor units spread across several muscles that effect articulator positioning and movement. This paper presents results from an analysis of tongue position variability during sustained vowel production. Data from two children (7 years 11 months, and 9years 7 months) and two young adults (both 20 years 7 months) are presented. Articulatory data were recorded with a 3D/4D ultrasound system, in two conditions: without a semi-occluded vocal tract (“without straw”) and with a semi-occluded vocal tract (“with straw”). Statistical analyses of tongue position variability revealed a main effect of age, with children showing greater variability than adults. There was no statistically significant main effect of condition, but the main effect of age was driven primarily by the “with straw” condition. We speculate that tongue position variability during sustained vowels may be an index of speech motor control maturity, and that the interaction between age and condition suggests children are less able than adults to rely on learned feed-forward motor programs under conditions of somatosensory perturbation, such as the presence of a straw between the lips.

Perturbation of cortical activity elicits regional and age-dependent effects on unconstrained reaching behavior: a pilot study.

Contributions from premotor and supplementary motor areas to reaching behavior in aging humans are not well understood. The objective of these experiments was to examine effects of perturbations to specific cortical areas on the control of unconstrained reaches against gravity by younger and older adults. Double-pulse transcranial magnetic stimulation (TMS) was applied to scalp locations targeting primary motor cortex (M1), dorsal premotor area (PMA), supplementary motor area (SMA), or dorsolateral prefrontal cortex (DLPFC). Stimulation was intended to perturb ongoing activity inthe targeted cortical region before or after a visual cue to initiate moderately paced reaches to one of three vertical target locations. Regional effects were observed in movement amplitude both early and late in the reach. Perturbation of PMA increased reach distance before the time of peak velocity to a greater extent than all other regions. Reaches showed greater deviation from a straight-line path around the time of peak velocity and greater overall curvature with perturbation of PMA and M1 relative to SMA and DLPFC. The perturbationincreased positional variability of the reach path at the time of peak velocityand the time elapsing after peak velocity. Although perturbations had stronger effects on reaches by younger subjects, this group exhibited less reach path variability at the time of peak velocity and required less time to adjust the movement trajectory thereafter. These findings support the role of PMA in visually guided reaching and suggest an age-related change in sensorimotor processing, possibly due to a loss of cortical inhibitory control.

Shell Measurements and Mold Thermal Mapping Approach to Characterize Steel Shell Formation in Peritectic Grade Steels

Herein, the prospects of detecting peritectic behavior in carbon steels (Fe–C) using solidified shell thickness measurements and real‐time mold thermal maps are investigated. Irregular steel shell thickness and localized shell thinning are negative conditions associated with the peritectic transformation in many steel grades. Detailed three dimensional (3D) thickness maps are generated to directly contrast peritectic from nonperitectic solidification features using a laboratory dip test. Characterization of the steel shell also includes measurement of 3D shell surface deviations from a nominally flat surface. The unevenness parameter, which is calculated using the coefficient of variation in shell thickness as a function of the carbon content in the steel, clearly peaks around 0.14%C. A distributed fiber‐optic sensor, embedded 1 mm from the working face of a 100 × 55 × 12 mm3 thick copper chill block, has been used to obtain real‐time mold thermal maps of the solidification event during immersion of the block into molten steel. A programmable drive is used to control the motion of the chill block during immersion into a steel bath to minimize variability in immersion speed, position, and time. The thermal mapping measurements are well correlated with the shell profile measurements.

Sources of Competitive Advantage of Enterprises in Selected Sectors of the Polish Economy

Purpose: Study impact of business activities on selection of sources of enterprises’ competitive advantage. The research hypothesis is advanced as H1: scope of business objects (sector) is a factor differentiating selection of sources of competitive advantage by enterprises. The concept and essence of competitiveness are discussed, methods of building competitive advantage by enterprises are detailed. Design/Methodology/Approach: The theoretical section follows a comprehensive review of leading specialist literature. The hypothesis is verified in the empirical section by means of position measures (arithmetic mean, median) and variability measures (standard deviation, coefficient of variability). Kruskal-Wallis test is also used to verify the research hypothesis. Findings: The paper contains results of a survey of 253 large Polish enterprises. Kruskal-Wallis test serves to determine impact of a sector on selection of sources of enterprise competitive advantage. Sector has no effect on choice of such sources as: quality management system, cost reduction, advertising, public relations, enterprise image, highly qualified managerial staff, knowledge and skills of employees, new technologies, or customer trust. Practical Implications: The results can be utilised by enterprises as guidelines for selection of sources of competitive advantage. Originality/Value: The paper contains an original study of a representative group of large enterprises that can be generalised to the whole population assuming a confidence level α=95% and maximum error β=6%.

Dynamics in an unusual acyl carrier protein from a ladderane lipid-synthesizing organism.

Anaerobic ammonium-oxidizing (anammox) bacteria express a distinct acyl carrier protein implicated in the biosynthesis of the highly unusual "ladderane" lipids these organisms produce. This "anammox-specific" ACP, or amxACP, shows several unique features such as a conserved FF motif and an unusual sequence in the functionally important helix III. Investigation of the protein's structure and dynamics, both in the crystal by ensemble refinement and by MD simulations, reveals that helix III adopts a rare six-residue-long 310 -helical conformation that confers a large degree of conformational and positional variability on this part of the protein. This way of introducing structural flexibility by using the inherent properties of 310 -helices appears unique among ACPs. Moreover, the structure suggests a role for the FF motif in shielding the thioester linkage between the protein's prosthetic group and its acyl cargo from hydrolysis.

Adult Auditory Brainstem Implant Outcomes and Three-Dimensional Electrode Array Position on Computed Tomography.

Factors contributing to auditory brainstem implant (ABI) outcomes are poorly understood. The aims of this study are to (1) characterize ABI electrode array position on postoperative imaging and (2) determine if variability in position is related to perceptual outcomes. Retrospective cohort study. Subjects were selected from the adult ABI recipient population at Massachusetts Eye and Ear. Postoperative three-dimensional (3D) computed tomography (CT) reconstruction of the head was used to measure ABI array position in 20 adult ABI recipients (17 with Neurofibromatosis Type 2 (NF2) and three non-NF2 recipients). Three-dimensional electrode array position was determined based on angles from the horizontal using posterior and lateral views and on distances between the proximal array tip superiorly from the basion (D1), laterally (D2P) and posteriorly (D2L) from the midline. Array position was correlated with perceptual data (in 15 of the 20 recipients who used their ABI). Perceptual data included the number of electrodes that provided auditory sensation, location and type of side effects, level of speech perception (from no sound to open-set word recognition of monosyllables) and the amount of charge required for auditory perception. Although the 3D orientation of the ABI array exhibited a variety of angles, all arrays were posteriorly tilted from the lateral view and most were medially tilted from the posterior view. ABI position relative to the basion from posterior showed mean distances of 1.71 ± 0.42 and 1.1 ± 0.29 cm for D1 and D2, respectively, and a mean D2 of 1.30 ± 0.45 cm from the lateral view. A strong linear negative correlation was found between the number of active electrodes and the distance of the proximal array tip laterally from the basion (D2P; rs = -0.73, p = 0.006) when measured in the posterior view. Although side effects were experienced in all recipients and varied in type and location across the array, electrodes in the middle part of the array tended to elicit auditory sensations while the proximal and distal tips of the array tended to elicit nonauditory side effects. Arrays with and without low charge thresholds appeared to generally overlap in position. However, the two recipients with the best (open-set) speech perception had low charge thresholds and had arrays that were tilted superiorly in the posterior view. ABI recipients with better speech perception appear to share a profile of arrays that are tilted superiorly as compared to recipients with lower speech perception levels. These ABI recipients have a high number of active electrodes (10 or more) and require less electrical charge on individual electrodes to achieve optimal stimulation.

Determination of Ir-192 micrselectron-V2 HDR/PDR dwell position reproducibility using a slit camera

PurposeTo examine the limits of dwell position reproducibility of an ELEKTA microSelectron-V2 HDR/PDR remote afterloader. Methods and MaterialsThe variability in source dwell position of an ELEKTA Microselectron mHDR – V2 HDR/PDR Microselectron was assessed using a slit camera. 100 consecutive extensions each of the source were made to positions of 1200 mm and 1470 mm and the variations in dwell position were observed. ResultsMaximum deviations of 0.4 mm from the median dwell position were observed. 72% of all deviations from median dwell position were 0.15 mm or less while 96% were no greater than 0.3 mm. ConclusionGuide wire flexibility makes buckling over the length of source extension an unavoidable reality which, in turn, produces variability in the dwell position achieved. Fortunately these deviations in source dwell position are small and may be compensated for using margins along the dose distribution length.

Benefits of Higher Cardiovascular and Motor Coordinative Fitness on Driving Behavior Are Mediated by Cognitive Functioning: A Path Analysis.

Driving is an important skill for older adults to maintain an independent lifestyle, and to preserve the quality of life. However, the ability to drive safely in older adults can be compromised by age-related cognitive decline. Performing an additional task during driving (e.g., adjusting the radio) increases cognitive demands and thus might additionally impair driving performance. Cognitive functioning has been shown to be positively related to physical activity/fitness such as cardiovascular and motor coordinative fitness. As such, a higher fitness level might be associated with higher cognitive resources and may therefore benefit driving performance under dual-task conditions. For the first time, the present study investigated whether this association of physical fitness and cognitive functioning causes an indirect relationship between physical fitness and dual-task driving performance through cognitive functions. Data from 120 healthy older adults (age: 69.56 ± 3.62, 53 female) were analyzed. Participants completed tests on cardiovascular fitness (cardiorespiratory capacity), motor coordinative fitness (composite score: static balance, psychomotor speed, bimanual dexterity), and cognitive functions (updating, inhibition, shifting, cognitive processing speed). Further, they performed a virtual car driving scenario where they additionally engaged in cognitively demanding tasks that were modeled after typical real-life activities during driving (typing or reasoning). Structural equation modeling (path analysis) was used to investigate whether cardiovascular and motor coordinative fitness were indirectly associated with lane keeping (i.e., variability in lateral position) and speed control (i.e., average velocity) while dual-task driving via cognitive functions. Both cardiovascular and motor coordinative fitness demonstrated the hypothesized indirect effects on dual-task driving. Motor coordinative fitness showed a significant indirect effect on lane keeping, while cardiovascular fitness demonstrated a trend-level indirect effect on speed control. Moreover, both fitness domains were positively related to different cognitive functions (processing speed and/or updating), and cognitive functions (updating or inhibition), in turn, were related to dual-task driving. These findings indicate that cognitive benefits associated with higher fitness may facilitate driving performance. Given that driving with lower cognitive capacity can result in serious consequences, this study emphasizes the importance for older adults to engage in a physically active lifestyle as it might serve as a preventive measure for driving safety.

Variability of Breast Surface Positioning Using an Active Breathing Coordinator for a Deep Inspiration Breath Hold Technique.

PurposeThe Elekta Active Breathing CoordinatorTM (ABC) is used to control breathing and guide deep inspiration breath hold (DIBH). It has been shown to be accurate in lung cancers, but limited analysis has been performed on the spatial accuracy and reproducibility of the breast surface. The use of optical surface-image guidance for patient positioning has grown in popularity and is an alternative solution for breast DIBH. This study aims to evaluate the breast surface variability of an ABC-guided DIBH by using a three-dimensional (3D) surface imaging system to record surface position.MethodsTen participants were placed in the treatment position, and breathing baselines and inhalation volume threshold baselines were monitored and recorded using the ABC. Over 60 minutes, the breathing patterns were recorded by the ABC and CatalystHDTM (C-RAD, Uppsala, Sweden). For each breath hold, the valve of the ABC closed at the baseline inhalation threshold and a 3D surface image was acquired. For each point on the baseline breast surface, a 3D vector was calculated to the subsequent breath hold surface as well as a root mean square (RMS) vector magnitude for the entire surface.ResultsThe average and standard deviation for the RMS difference between the baseline and subsequent evaluated images were 7.12 ± 2.70 mm.ConclusionThis study shows that while the ABC-guided inhalation volume is kept constant, a non-negligible variability of the breast surface position exists. Special considerations should be used in clinical situations, where the positioning of the surface is considered more important than inhalation volume.

Changes in the characteristics of North Pacific Jet as a Conduit for U. S. surface air temperature in boreal winter across the late 1990s

AbstractThe leading modes of the North Pacific Jet (NPJ) variability include intensity changes and meridional shifts in jet position on the low frequency timescales. These leading modes of NPJ variability are closely associated with weather and climate conditions spanning from Asia to the United States (US). In this study, we investigated changes in the NPJ’s role as a conduit for US surface air temperature (SAT) anomalies during the boreal winter across the late 1990s. We found that the leading mode of NPJ variability changed from the NPJ intensity changes to meridional shifts in NPJ position across the late 1990s. It leads to the change in the role of NPJ as a conduit for US SAT anomalies. Before the late 1990s, the variability of NPJ’s intensity significantly impacted western US SAT anomalies related to the anomalous surface cyclonic circulation over the North Pacific. After the late 1990s, however, the variability of NPJ’s meridional shift significantly influenced on the eastern US SAT anomalies in association with the anomalous surface cyclonic circulation over the northern North Pacific. Further analysis and model experiments revealed that the western to central North Pacific Ocean has been warming since the late 1990s and modulates atmospheric baroclinicity. This phenomenon mainly leads to a northward NPJ shift and implies that the eddy driven mechanism on the NPJ’s formation, which acts to enhance the meridional variability of NPJ position, becomes dominant. We conclude that this northward shift of NPJ could have contributed to enhancing the NPJ’s meridional shift variability, significantly influencing the eastern US SAT anomalies since the late 1990s.

Non-algorithmic approach to accessory pathway localization based on a mobile app

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Polish Cardiac Society - Section of Non-invasive Electrocardiology and Telemonitoring (PTK SENIT) Background. Electrocardiographical localization of accessory pathways (AP) in WPW syndrome remains an elusive goal. Despite several, often very complex algorithms that were developed over the last three decades, none of them is very accurate - as demonstrated by several independent validation studies. Moreover, algorithms are difficult to remember, which further limits their usefulness. The accessory pathway regions are arbitrary and transitions between them are smooth, not binary. The same applies to ECG features such as QRS polarity – they are not binary. Moreover, even the most careful ECG lead placement cannot compensate for the variability in heart position within the chest. Therefore, it is unrealistic to expect that any ECG feature or feature set will precisely identify a particular location in a 0 vs. 1 fashion. Aim We intend to create a mobile app / web based localizing application, that would support a novel method for AP localization: a colour density map generator - based on actual distribution of a sizable number of accessory pathway with a particular QRS features. Methods A total of 881 consecutive AP ablation procedures were reviewed and patients with successful ablation of an overt accessory pathway were included. ECG with baseline and full preexcitation obtained during incremental atrial pacing were obtained. AP localization was based on stored fluoroscopic images in several projections and procedure description. Each AP localization, as well as QRS polarity in all 12 leads, separately for full and baseline preexcitation patterns, were coded and introduced into the application database. An application web-based, optimized for mobile devices was developed. This application enabled to graphically show changing localization of AP with regard to the introduced, at each step, QRS polarity in a particular ECG lead. User can choose his/her own steps or criteria; there is no need to adhere to the proposed steps. Results A total of 604 patients/ ECGs were available for density map generation. With each additional lead QRS information introduced into the application the user can appreciate more and more precise localization of the AP. This quickly enables to pinpoint the area of maximum probability, i.e. the most likely/frequent location, followed by the immediate adjacent locations. Representative screen shots of to typical inital steps for left- and right-sided APs are provided below (Figure 1 and Figure 2). Limited prospective assessment was very favourable. Conclusions A novel method, easy to use, not requiring to remember any algorithmic steps, and based on an analysis of by far the largest cohort of over accessory pathways (in comparison with published algorithms) was developed. Prospective validation of the localization application seems warranted. Abstract Figure.

Postmidnight mid-latitude ionospheric trough position oscillations during solar cycle 24

In this work, the Global Ionospheric Maps (GIMs) are used to analyze the behavior of the mid-latitude ionospheric trough (MIT) during the solar cycle 24 (2008–2019). This analysis is performed for the Northern and Southern Hemispheres at different local times: 00, 02 and 04 LT. We study the MIT position dependence on the phase of the solar cycle, seasonal, and geomagnetic activity during the post-midnight period. We find that the MIT position shows an interhemispheric asymmetry. Its equatorward movement from low to high solar activity is about 3 ° and 1 ° for Northern and Southern Hemisphere respectively for the three local times analyzed. There is also a clear seasonal variation, the shift between winter and summer is around 3 ° and 1 ° at 00 LT and 6 ° and 4 ° at 04 LT for the Northern and Southern Hemispheres, respectively. In general, the MIT position reaches the highest geomagnetic latitude in winter, without variation with local time. However, in summer it takes the lowest geomagnetic latitude, moving towards the equator from 00LT to 04LT. The MIT position moves equatorward under disturbed geomagnetic conditions, and the difference between the MIT position during quiet and perturbed days is greater in the Northern than in the Southern Hemisphere. In addition, the periodicity of the variability of the MIT position for both Hemispheres versus the solar wind speed and IMF Bz-component are analyzed using the wavelet transform, showing a clear dependence between them during the descending and minimum solar phase at 13.5 and 27-day time scales.

Optical Imaging-Based Guidance of Viral Microinjections and Insertion of a Laminar Electrophysiology Probe Into a Predetermined Barrel in Mouse Area S1BF.

Wide-field Optical Imaging of Intrinsic Signals (OI-IS; Grinvald et al., 1986) is a method for imaging functional brain hemodynamic responses, mainly used to image activity from the surface of the cerebral cortex. It localizes small functional modules – such as cortical columns – with great spatial resolution and spatial specificity relative to the site of increases in neuronal activity. OI-IS is capable of imaging responses either through an intact or thinned skull or following a craniotomy. Therefore, it is minimally invasive, which makes it ideal for survival experiments. Here we describe OI-IS-based methods for guiding microinjections of optogenetics viral vectors in proximity to small functional modules (S1 barrels) of the cerebral cortex and for guiding the insertion of electrodes for electrophysiological recording into such modules. We validate our proposed methods by tissue processing of the cerebral barrel field area, revealing the track of the electrode in a predetermined barrel. In addition, we demonstrate the use of optical imaging to visualize the spatial extent of the optogenetics photostimulation, making it possible to estimate one of the two variables that conjointly determine which region of the brain is stimulated. Lastly, we demonstrate the use of OI-IS at high-magnification for imaging the upper recording contacts of a laminar probe, making it possible to estimate the insertion depth of all contacts relative to the surface of the cortex. These methods support the precise positioning of microinjections and recording electrodes, thus overcoming the variability in the spatial position of fine-scale functional modules.

The Impact of the Human Body Position Changes During Wheelchair Propelling on Motion Resistance Force: A Preliminary Study.

The aim of this research was to analyze the impact of the human body position changes caused by propelling a wheelchair with the pushrim propulsion on the value of motion resistance force. The discussed research works are in progress; therefore, the presented results should be treated as preliminary. The research was carried out in the group of six volunteers propelling a wheelchair of which frame was inclined, in respect to the horizontal plane, under the angle of 0 deg, 7 deg, and 14 deg. The area of the position variability of the human body center of gravity (COG) and the coefficients of wheelchair rolling resistance have been determined. Based on the measurements conducted, rolling resistance force FT and motion resistance force FR have been defined for three values of frame inclination angle. The determined force of rolling resistance Ft depended on the location of the COG of the human body and the value of the coefficients of rolling resistance of the front and rear wheels of a wheelchair. This force was a component of the resistance to motion FR, which also took into account the influence of gravity resulting from the inclination of the wheelchair on an inclined plane. For the tested inclination angles relative to the horizontal plane, the rolling resistance force ranged from 9.82 N to 22.81 N. Analyzing the variability of the rolling resistance force FT, it was found that for the final phase of the driving motion, it increased by 36% for the inclination angle of 0 deg and 43% for the inclination angle of 7 deg. Its increase was 48% for the inclination angle of 14 deg in relation to the human body position for the beginning of the driving motion. In the case of measuring the value of the resistance to motion FR, it was observed that, depending on the angle of the incline of the wheelchair, it ranged from 14.69 N to 256.33 N. The measurements conducted enabled the derivation of an analytical model for determining rolling resistance force depending on the position of the human body COG and the wheelchair inclination angle. The conducted research demonstrated the impact of the COG position on the changes of motion resistance force, thus expanding the state of knowledge, introducing a new parameter which, like a surface type and wheel type, affects motion resistances.