44 results
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2. Intimate Outer Space: Towards a Politics of Gravity, Waste, and the Spatial Orientation of Bodies.
- Author
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Sammler, Katherine G.
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OUTER space ,REDUCED gravity environments ,SPATIAL orientation ,GRAVITATIONAL fields ,GRAVITY - Abstract
Examining the feat of maintaining life in orbit draws a sharp focus to the relationship between the human body and its environment, the porous and circulatory matter that blurs any boundaries between habitat and habitant. These intimate, engineered spaces evoke a microcosm of urgent planetary concerns surrounding air and water resources, and waste capture, storage, and elimination. This paper explores NASA's management of biological operations and discharge wastes in low gravity environments. Without strong gravitational fields, liquids coalesce at the location they are created, instead of flowing down and away. Such excesses disrupt the orderly engineered environments and minutely monitored bodies of these techno-scientific endeavors. Analyzing astronaut tears, space gynecology, zero-g surgery, and NASA's "Space Poop Challenge" through feminist queer and disability theory, new materialist, and discard studies lenses, this paper seeks to refigure the deeply entangled relationships between fleshy bodies and planetary bodies, biomass and geomass, and prompt new discussions of gravity politics. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Partial Shading of Photovoltaic Modules with Thin Linear Objects: Modelling in MATLAB Environment and Measurement Experiments.
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Teneta, Janusz, Kreft, Wojciech, and Janowski, Mirosław
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SPATIAL orientation ,WEATHER ,PHOTOVOLTAIC power generation ,MATHEMATICAL models ,STATISTICS - Abstract
This paper proposes a mathematical model for the shading profiles of a PV module with thin, long linear elements. The model includes the brightness distribution over the entire shading region (umbra, penumbra, and antumbra). A corresponding calculation code in the form of m-files has been prepared for the MATLAB environment. The input data for the calculations are the coordinates of the Sun's position in the sky, the dimensions and spatial orientation of the shading element, and the spatial orientation of the shaded PV module. The correctness of the model was verified by a measurement experiment carried out under actual outdoor weather conditions. Statistical analysis of the comparison between the measurement data from the experiment and the model showed its high accuracy. As part of this research work, it was also checked how shading with thin linear elements affects the current–voltage characteristics of the module. It turned out that even a small linear shading could reduce the power output of the module by more than 6%, with the distribution of this shading across the individual cells of the module being extremely important. [ABSTRACT FROM AUTHOR]
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- 2024
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4. On the Spatial Buckling of Elastic Columns.
- Author
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Kočman, Peter, Schnabl, Simon, and Planinc, Igor
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SHEAR (Mechanics) , *ALGEBRAIC equations , *ANALYTICAL solutions , *SPATIAL orientation , *MECHANICAL buckling , *COMPOSITE columns , *LAMINATED composite beams - Abstract
This paper presents a novel analytical solution for the buckling load in 3D of columns that fills a gap in the existing literature by accounting for shear deformation and spatial effects. The latter means that a column can be supported and buckle in any direction. We build on the foundational work of Simo and use a 3D beam model to derive a set of equations that form the basis for our analytical solution. The paper outlines the axioms of the Simo model, presents the corresponding equations, and describes the linearization procedure in details. By linearizing the equations we obtain a set of algebraic equations with boundary conditions, which we manipulate into an analytical solution for the buckling load. An illustrative example using a column with an elliptical cross-section shows how different boundary conditions and the spatial orientation of the column influence the buckling load. This research work not only contributes to the verification of numerical programs, but also provides engineers with a valuable tool for optimizing structural configurations. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Enmeshed with the digital: satellite navigation and the phenomenology of drivers' spaces.
- Author
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Berger, Viktor
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ARTIFICIAL satellites in navigation , *BODY schema , *SPATIAL orientation , *SPACE perception , *PHENOMENOLOGY - Abstract
This paper aims to develop a theoretical interpretation of how satellite navigation transforms drivers' experience of automotive spaces. The use of satellite navigation has, so far, been predominantly studied from a cognitivist perspective based on the computer model of cognition and the theory of spatial disengagement. Experimental studies have concluded that over-reliance on digital navigation tools diminishes spatial orientation and spatial memory. According to the dominant interpretation, satellite navigation causes disengagement from space. After addressing these approaches, the paper introduces an embodied perspective of satellite navigation. This is accomplished by applying the phenomenology of perception of Maurice Merleau-Ponty, whose notions, such as perception, body schema, motor habit, and virtual body, illuminate otherwise undertheorized dimensions of drivers' spaces. By using digital tools for wayfinding, drivers' body schema, virtual body, and perception of space are modified, thereby enabling an engagement with convoluted 'mesh spaces.' This new term is integral to the interpretation of drivers' spaces, as well as being distinct from that of 'hybrid space,' although both aim to conceptualize spaces, including physical objects and their visual representations. Conclusions will be drawn against the broader context of the mediatization of everyday life. [ABSTRACT FROM AUTHOR]
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- 2024
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6. The Contribution of Internal and External Factors to Human Spatial Navigation.
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Piccardi, Laura, Nori, Raffaella, Cimadevilla, Jose Manuel, and Kozhevnikov, María
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BILINGUALISM ,CONTROL (Psychology) ,EXECUTIVE function ,RECOGNITION (Psychology) ,SPATIAL orientation ,NAVIGATION - Abstract
This document, titled "The Contribution of Internal and External Factors to Human Spatial Navigation," explores the various factors that influence spatial navigation. The authors discuss the importance of cognitive processes such as memory, attention, and problem-solving skills, as well as internal and external factors like age, gender, familiarity with the environment, and landmark attributes. The document includes seven papers from distinguished scientists in the field, covering topics such as verbal and imagery-based strategies, bilingualism, mood disorders, different types of cognitive maps, the effects of spaceflight on brain activity, and the influence of cues and gender on spatial navigation. The authors emphasize the need for further research to fully understand the complex factors that impact navigation and to develop new approaches and protocols. [Extracted from the article]
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- 2024
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7. Statistical evaluation of measured biomechanical properties of human brain aneurysm samples.
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Krisztina, TÓTH Brigitta, András, LENGYEL, and István, NYÁRY
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ANEURYSMS ,RUPTURED aneurysms ,STRAINS & stresses (Mechanics) ,INTRACRANIAL aneurysm ruptures ,SPATIAL orientation - Abstract
Copyright of Clinical Neuroscience / Ideggyógyászati Szemle is the property of LifeTime Media Kft. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2024
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8. Hybrid quantitative–qualitative method for technology portfolio selection: a case study of Iran's space industry.
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Chizari, Emad, Sedighy, Seyed Hasan, Pishvaee, Mir Saman, and Azar, Adel
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SPACE industrialization ,TECHNOLOGY assessment ,GOAL programming ,HYBRID systems ,SPATIAL orientation ,DEVELOPING countries - Abstract
The space industry is known as an economic driver for many world economies. In Iran, the acquisition of satellite technology knowledge is one of the achievements of the country's scientific and technological indicators in recent years, but the position and importance of optimal investment in this industry in Iran have been ignored. The optimal technology portfolio is one of the tools that can cover this gap and lead to better decision-making by policymakers. In this paper, the optimum technology portfolio determination regarding its goals, attributes and challenges is addressed for Iran's space industry with a hybrid quantitative–qualitative method in two short and medium-term periods. We formulate a technology portfolio selection model with these multi-objective functions: maximization of benefits in using different technologies comprising of both short and medium-term portfolios, maximizing the total summation of all Technology Readiness Levels (TRLs) of technologies, maximizing the acquisition speed for the technologies, and minimizing the acquisition risk of technologies in each portfolio. In the proposed model, the usability, acquisition cost, and complexity of each technology are considered meticulously. Also, the goal programming method is used to integrate the objective functions. Another novelty of this paper is the formulation of two portfolios with two different periods in which their corresponding inputs and outputs affect the other. This research can significantly help in directing the country's investment in the space industry, spatial ecosystem orientation, facilitating the creation of space-based businesses, improving economic growth, and also providing guidelines to improve the related policies in this area. In addition, this research can be an inspiration for other developing countries in the space industry. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Intelligent identification method for pipeline ultrasonic internal inspection.
- Author
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Guangli, Xu, Zhihao, Zhou, Shuo, Xin, Ziwei, Lin, and Liangxue, Cai
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AUTOMATIC identification , *WAVELET transforms , *SPATIAL orientation , *SIGNAL processing , *TEST systems , *ULTRASONIC testing - Abstract
In pipeline ultrasonic testing, the accurate identification of defect types is a prerequisite for quantifying defect sizes. To this end, this paper proposes a defect identification algorithm based on the combination of Wavelet Packet Transform (WPT), Distance Evaluation Technique (DET) and GA-SVM to precisely identify defect boundaries. First, the ultrasonic echo signals are processed using WPT to more accurately extract defect information. Then, DET is employed to eliminate redundant feature parameters, which are sorted by sensitivity to determine the input feature parameters for the GA-SVM. On this basis, a self-developed ultrasonic testing experimental system is used to collect ultrasonic echo signals from Q235 steel pipes with cylindrical, spherical, and conical defects at different spatial orientations of the probe and the pipe. After processing and identifying the signals, it was found that the proposed algorithm achieves an average identification accuracy of 99% for different types of defects, thereby realising automatic identification of pipeline defects. The results provide new ideas and methods for the intelligent identification of volumetric defect types in pipeline ultrasonic internal testing and promote the development of industrial-grade ultrasonic internal detectors. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Three-dimensional pore network of kaolin using FIB-SEM imaging.
- Author
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Ding, Yanzheng, Bennai, Fares, Jrad, Mohamad, Guyon, Julien, and Hattab, Mahdia
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KAOLIN , *FOCUSED ion beams , *COMPRESSION loads , *PORE size distribution , *SPATIAL orientation - Abstract
The aim of this paper is to propose a new approach permitting the investigation of the 3D pore variation of kaolin K13 in relation with mechanical loading. A mechanical loading consisting of one-dimensional compression and oedometric loading is applied to a sample of centimeter scale. A postmortem protocol using scanning electron microscopy (SEM) coupled with Focused Ion Beam (FIB) was carried out to observe and then obtain a large number of slices of an extracted sub-volume from the small sample. Image analysis using a new processing method enabled the reconstruction of the observed and extracted sub-volume in the form of a rebuilt sub-volume. The segmentation of pores and particles was carried out using an approach based on machine learning and the pore space properties can be quantified. Pore morphology was identified based on two parameters namely the flatness and the elongation. Spatial orientation can also be locally determined. The proposed treatment enabled the distribution of pore size (termed Im_PSD) to be deduced and these were then compared with the results of Mercury intrusion porosimetry technique. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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11. Aerial display that reconstructs face orientation by use of spatial blending of two face images.
- Author
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Kishinami, Kohei, Sato, Keigo, Yasugi, Masaki, Suyama, Shiro, and Yamamoto, Hirotsugu
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SPATIAL orientation , *DISPLAY systems , *SPATIAL systems , *PROTOTYPES - Abstract
This paper proposes a novel aerial display system that reconstructs face orientation. The proposed system forms two face images floating in mid‐air. Viewers observe a spatially blended image of the two face images, where the spatial blending ratio depends on the viewing position. Thus, the spatially blended aerial face image is perceived to look in a fixed orientation even if the viewing position is changed within a certain viewing range. We analyze the spatial blending system optical design and show results from our prototype display. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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12. Localizing gradient damage model for anisotropic materials: Focusing on timber.
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Shala, Shqipron and Waisman, Haim
- Subjects
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DAMAGE models , *FRACTURE mechanics , *TIMBER , *BENCHMARK problems (Computer science) , *SPATIAL orientation - Abstract
This paper presents a new damage model for transversely isotropic materials, with special focus on timber. The model proposed in this study is formulated by employing the localized gradient form of continuum damage theory. The model accounts for anisotropic damage through two damage variables, delineating damage parallel and perpendicular to the grain, representing isotropic damage within the cross-sectional plane. The conditions assumed in this work pertain to loading scenarios that occur within the plane. An additional fourth-order tensor transformation is incorporated to facilitate the conversion between the global and local reference frames, allowing for arbitrary spatial orientations of the material matrix. In this work we concentrate on damage arising from tensile and shear stresses. The model is implemented as a consistent linearized coupled (monolithic) problem. The performance verification of the model relies on numerous numerical examples, incorporating experimental benchmark problems. The outcomes demonstrate that the suggested damage model adeptly captures both the initiation of failure and the propagation of damage. [Display omitted] • A 3D damage model for timber using the localizing gradient damage methodology. • Arbitrary spatial anisotropic material failure is traced. • Arbitrary spatial material matrix distribution is covered. • Quasi-brittle failure of timber is benchmarked using experimental data. [ABSTRACT FROM AUTHOR]
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- 2024
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13. A method for analyzing discontinuities characterization using the integration of underground drift point cloud with 3DEC software.
- Author
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Gu, Zhongyuan, Xiong, Xin, Yang, Chengye, and Cao, Miaocong
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SOFTWARE as a service ,POINT cloud ,CLOUD computing ,SPATIAL orientation ,THREE-dimensional modeling - Abstract
• Combination of three-dimensional laser scanning and 3DEC identifies rock mass discontinuities geometrical information. • A method for the characterization of discontinuities using 3DEC in a three-dimensional drift model is proposed. • A new method for calculating the three-dimensional intensity P 32 is proposed. The geometric statistical characteristics of rock mass discontinuities, such as mean trace length and intensity, cannot be measured directly and require the use of statistical tools (such as sampling lines, sampling windows, and drilling) for analysis. In this paper, we propose a method for extracting discontinuity characteristics using the 3DEC software in three-dimensional (3D) drift models (3DM). Specifically, we introduce the Surface Disk Discontinuity Model (SDDM) as a representation model for planar and linear discontinuities identified in point clouds. By importing the 3DM and SDDM into 3DEC and utilizing a multi-circular window, we calculate the mean trace lengths and two-dimensional (2D) intensity (P 21). Additionally, we propose a method to estimate the three-dimensional (3D) intensity (P 32), which provides a more comprehensive reflection of the discontinuous characteristics in different spatial orientations. To validate the proposed method, we apply it to the underground drift of the Jiapigou gold mine in Jilin Province to extract the geometric statistical characteristics of discontinuities. The results demonstrate that our method successfully captures the orientation, trace length, and P 32 characteristics of four dominant discontinuity groups in the study area. This approach proves to be an effective technique for utilizing 3D laser scanning to obtain accurate discontinuity characteristics of rock mass. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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14. A Novel Training Program to Improve Human Spatial Orientation: Preliminary Findings.
- Author
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McLaren-Gradinaru, Michael, Burles, Ford, Dhillon, Inderpreet, David, Adam Leonidas, Umiltà, Alberto, Hannah, Jaimy, Dolhan, Kira, and Iaria, Giuseppe
- Subjects
SPATIAL orientation ,MENTAL representation ,COGNITIVE maps (Psychology) ,TRAINING of volunteers ,BEHAVIORAL assessment ,DIALECTICAL behavior therapy - Abstract
The ability to form a mental representation of the surroundings is a critical skill for spatial navigation and orientation in humans. Such a mental representation is known as a "cognitive map" and is formed as individuals familiarize themselves with the surrounding, providing detailed information about salient environmental landmarks and their spatial relationships. Despite evidence of the malleability and potential for training spatial orientation skills in humans, it remains unknown if the specific ability to form cognitive maps can be improved by an appositely developed training program. Here, we present a newly developed computerized 12-days training program in a virtual environment designed specifically to stimulate the acquisition of this important skill. We asked 15 healthy volunteers to complete the training program and perform a comprehensive spatial behavioral assessment before and after the training. We asked participants to become familiar with the environment by navigating a small area before slowly building them up to navigate within the larger and more complex environment; we asked them to travel back and forth between environmental landmarks until they had built an understanding of where those landmarks resided with respect to one another. This process repeated until participants had visited every landmark in the virtual town and had learned where each landmark resided with respect to the others. The results of this study confirmed the feasibility of the training program and suggested an improvement in the ability of participants to form mental representations of the spatial surrounding. This study provides preliminary findings on the feasibility of a 12-days program in training spatial orientation skills. We discuss the utility and potential impact of this training program in the lives of the many individuals affected by topographical disorientation as a result of an acquired or developmental condition. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. The Reproducibility of Reference Landmarks in the External Acoustic Meatus (EAM) on Cone Beam Computed Tomography (CBCT) Images.
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Sanders-Mello, Fernanda, Jonkman, Ronald E. G., Baltussen, Ynke, Rozema, Frederik R., and Koolstra, Jan Harm
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CONE beam computed tomography ,ACOUSTIC imaging ,THREE-dimensional imaging ,DIAGNOSTIC imaging ,SPATIAL orientation - Abstract
Objective: The aim of the present study is to identify a more reliable reference point in three-dimensional cephalometric analysis to replace the Porion point used in two-dimensional analysis, enhancing the accuracy of assessments. Methods: The methodology assessed potential alternative landmarks for three-dimensional cephalometric analysis. Utilizing a segmenting technique, anatomical landmarks were accurately pinpointed from the external acoustic meatus of 26 Cone Beam Computed Tomography (CBCT) scans. These landmarks were chosen for their clear and unambiguous detectability. To assess reproducibility, each landmark was replicated twice with a one-week interval by a master's student. Reproducibility was quantitatively evaluated by analyzing the absolute difference per axis. Results: Five possible candidate landmarks were identified: the most anterior, posterior, superior, and inferior points of the external acoustic meatus (EAM) and a notch delineating the epitympanic recess. The reproducibility of pinpointing these landmarks ranged from 0.56 mm to 2.2 mm. The absolute mean differences between measurements were 0.46 mm (SD 0.75) for the most anterior point, 0.36 mm (SD 0.44) for the most posterior point, 0.25 mm (SD 0.26) for the most superior point, 1.11 mm (SD 1.03) for the most inferior point, and 0.78 mm (SD 0.57) for the epitympanic notch. Conclusions: The most superior point of the EAM might successfully replace the Porion as an anatomical reference. [ABSTRACT FROM AUTHOR]
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- 2024
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16. Strobe training as a visual training method that improves performance in climbing.
- Author
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Vasile, Antonia Ioana and Stănescu, Monica Iulia
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COGNITIVE ability ,ATHLETIC ability ,VISUAL memory ,PHYSICAL training & conditioning ,CONTROL groups - Abstract
Introduction: Strobe training is a form of visual training where the athlete has to practice during intermittently dark conditions. Strobe training improves visual, perceptual, and cognitive skills, which will enhance athletic performance. Strobe training can influence multiple training components in climbing: psychological, tactical, physical, and technical training. Materials and methods: The study was conducted on 17 elite climbers from Romania (10 male and 7 female), representing the entire National Youth Climbing Team. The research group was divided into a control group (n=8) and an experimental group (n = 9). The used instruments were the Cognitrom battery (for cognitive skills, such as spatial skills and reactivity), the Witty SEM system (for motor-cognitive skills, such as cognitive agility, visual processing speed, and visual memory), and the International Rock Climbing Research Association (IRCRA) performance-related test battery for climbers (climbingspecific motor skills). The experimental group had 20 strobe training sessions, which took place during one calendar year, as an additional session to their climbing schedule done with their principal trainer. The strobe session was once a week, depending on the periodization of the macrocycle (preparatory, competitional, and transition periods). The control group and the experimental group had similar climbing training sessions during the 1-year macrocycle in terms of intensity and volume of their training. Results: Strobe training improved on-sight performance (d = 0.38) and red-point performance (d = 0.36). Strobe training improved the majority of cognitive skills [all spatial skills (d = 1.27 for mental image transformation; d = 1.14 for spatial orientation; d = 1.59 for image generation) and simple reaction time (d = 0.99)]. Strobe training improved all motor-cognitive skills (d = 0.16 for visual memory; d = 1.96 for visual memory errors; d = 1.39 for visual processing speed; d = 1.94 for visual processing errors; d = 1.30 for cognitive agility). Strobe training improved many climbing-specific parameters (flexibility and upper body strength) (d = 0.44 and d = 0.47 for flexibility parameters; d = 0.50 to 0.73 for upper body strength parameters). Discussion: Strobe training is an effective training method for enhancing performance that should be used on more experienced climbers. It acts more on spatial skills, rather than on reactivity skills, developing the visual-motor coordination system. Strobe training has greater effects on climbers aged below 16 years, as youth athletes rely more on visual input compared to adults. The improvement in climbing-specific variables was due to the additional climbing session done weekly. Strobe training acts more on the cognitive component of training than on the motor component of training in climbing. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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17. Effect of Gender and Communicative Situation on Double Spatial Orientation in Virtual Speech
- Author
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Konstantin I. Belousov and Aleksandar Taleski
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virtual reality ,spatial orientation ,deixis ,gender ,communication ,Philology. Linguistics ,P1-1091 ,Social Sciences - Abstract
A clear and unambiguous rendering of spatial relations is the key cognitive function of communication. Spatial relationships reflect the categories and experience shared by all people. The paper introduces the first-of-its-kind attempt to describe the dual spatial orientation of the speaker in virtual reality as depending on two factors: the communicative situation and the gender. Dual spatial orientation combines egocentric, allocentric, or geocentric orientations and their varieties. The combination depends on various factors. The experiment in virtual environment involved 24 informants and five scenarios (scenes) with different communicative parameters. It yielded 725 responses with combinations of double orientations, which went through the IS Semograph. The combination of allocentric and geocentric orientation domineered; the extra-linguistic gender factor and some communicative parameters affected the frequency of combinations of dual spatial orientation. The core of the speaker’s dual spatial orientation in virtual reality combined allocentric and geocentric orientations to the topos of GE \ T + AL and AL + GE \ T.
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- 2024
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18. The Suite for the Assessment of Low-Level cues on Orientation (SALLO): The psychophysics of spatial orientation in virtual reality
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Esposito, Davide, Bollini, Alice, and Gori, Monica
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- 2024
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19. Interaction of orientation cues within a nested virtual environment.
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Allison, Craig, Wood, Antony P., and Redhead, Edward S.
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VIRTUAL reality ,ASSOCIATIVE learning ,SPATIAL orientation - Abstract
Three experiments examined whether three factors (view of external targets, colored wall cues, previous exploration of room) facilitate orientation within a virtual building and whether the interaction between the first two factors align with predictions from associative learning. Participants were teleported into a virtual room and asked to face in the direction of an external occluded target using all, none, or a combination of these factors. Experiment 1 (n = 62) showed all 3 factors individually improved orientation. Experiment 2 (n = 28) illustrated that the interaction between external targets and colored wall cues was similar to an associative learning phenomenon, where more salient cues inhibit learning about less salient cues (called overshadowing). Previous research suggests salience of spatial cues can be moderated by familiarity with the cues. In both Experiment 1 and 2, participants were familiar with the external targets but not the colored wall cues. Experiment 3 (n = 92) manipulated familiarity with the external targets and found that when participants were not familiar with the external targets, they became overshadowed by colored wall cues. The results are a novel demonstration that spatial cues within a nested environment interact in a way predicted by associative learning. • Paper manipulated features within a nested environment to investigate their effects on orientation. • External landmarks, previous experience of visiting a location and internal landmarks enhance orientation. • External landmarks control orientation when simultaneously presented with internal landmarks in a manner similar to overshadowing typical of associative learning mechanisms. • Reducing familiarity with external landmarks reversed the overshadowing effect with the internal landmark now controlling overshadowing. • Novel demonstration of associative a phenomenon in a nested environment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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20. Fibre orientation in SFRC slabs and consequences for punching shear and flexural resistance.
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Hernández Fraile, Diego, Faccin, Enrico, Minelli, Fausto, Plizzari, Giovanni, and Muttoni, Aurelio
- Subjects
- *
CONSTRUCTION slabs , *FIBERS , *REINFORCED concrete , *STANDARDIZED tests , *SPATIAL orientation , *SHEARING force - Abstract
The use of steel fibre reinforced concrete (SFRC) is a well-known method for enhancing the punching and flexural resistances of flat slabs. The structural performance of SFRC elements depends significantly on the fibre distribution and orientation, which are typically unknown. One of the largest uncertainties regarding the performance and reliability of SFRC concerns the determination of its post-cracking mechanical properties in the real structural element, normally performed via standardised tests. However, due to differences in element sizes and casting procedures, and to the presence of rebars, the fibre spatial distribution and orientation in the standard specimens differ in general from those of the structural member. Several researchers have studied the correlation between the orientation of fibres and the mechanical performance of SFRC, yet tests were rarely carried out under representative conditions of the actual behaviour of the target structural member. The present paper analyses the spatial distribution and orientation of steel fibres in six SFRC flat slabs that were previously tested in concentric punching at the University of Brescia. The aim of this work is to analyse the fibre orientation and spatial distribution in structural elements. Cores were extracted from the specimens after the punching tests and scanned using micro-computed tomography (μ -CT) to reconstruct the fibre skeleton. The fibre arrangement was analysed focusing on the variation of the fibre spatial distribution and orientation through the slab thickness. A formulation to express the actual fibre dispersion in concrete is proposed, and effectiveness factors are defined to reflect the efficacy of fibres in punching shear and flexure, based on their location in the slab thickness. Pseudo-horizontal fibre orientations are found to be governing, with closer distributions to a 2D scenario for thicker slabs and higher fibre contents. Furthermore, the influence of flexural reinforcement on the fibre orientation has been observed to be significant. The observed fibre orientations are detrimental for the direct transfer of shear forces across cracks, but are favourable for enhancing the flexural capacity of the slab. • 18 cores extracted from six SFRC flat slabs previously tested in punching. • 3D core reconstruction and fibre skeletonization with micro-Computed Tomography. • Fibre distribution and orientation analysed for various slab sizes, fibre dosages. • Fibre orientation parameters defined for comparison with an isotropic distribution. • Effectiveness factors evaluate enhancement of punching and flexural slab resistance. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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21. PCP auto count: a novel Fiji/ImageJ plug-in for automated quantification of planar cell polarity and cell counting.
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Stansak, Kendra L., Baum, Luke D., Ghosh, Sumana, Thapa, Punam, Vanga, Vineel, and Walters, Bradley J.
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CELL polarity ,HAIR cells ,INNER ear ,SPATIAL orientation ,COUNTING - Abstract
Introdution: During development, planes of cells give rise to complex tissues and organs. The proper functioning of these tissues is critically dependent on proper inter- and intra-cellular spatial orientation, a feature known as planar cell polarity (PCP). To study the genetic and environmental factors affecting planar cell polarity, investigators must often manually measure cell orientations, which is a timeconsuming endeavor. To automate cell counting and planar cell polarity data collection we developed a Fiji/ImageJ plug-in called PCP Auto Count (PCPA). Methods: PCPA analyzes binary images and identifies "chunks" of white pixels that contain "caves" of infiltrated black pixels. For validation, inner ear sensory epithelia including cochleae and utricles from mice were immunostained for βII-spectrin and imaged with a confocal microscope. Images were preprocessed using existing Fiji functionality to enhance contrast, make binary, and reduce noise. An investigator rated PCPA cochlear hair cell angle measurements for accuracy using a one to five agreement scale. For utricle samples, PCPA derived measurements were directly compared against manually derived angle measurements and the concordance correlation coefficient (CCC) and Bland-Altman limits of agreement were calculated. PCPA was also tested against previously published images examining PCP in various tissues and across various species suggesting fairly broad utility. Results: PCPA was able to recognize and count 99.81% of cochlear hair cells, and was able to obtain ideally accurate planar cell polarity measurements for at least 96% of hair cells. When allowing for a <10° deviation from "perfect" measurements, PCPA's accuracy increased to 98%-100% for all users and across all samples. When PCPA's measurements were compared with manual angle measurements for E17.5 utricles there was negligible bias (<0.5°), and a CCC of 0.999. Qualitative examination of example images of Drosophila ommatidia, mouse ependymal cells, and mouse radial progenitors revealed a high level of accuracy for PCPA across a variety of stains, tissue types, and species. Discussion: Altogether, the data suggest that the PCPA plug-in suite is a robust and accurate tool for the automated collection of cell counts and PCP angle measurements. [ABSTRACT FROM AUTHOR]
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- 2024
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22. Estimating receptive fields of simple and complex cells in early visual cortex: A convolutional neural network model with parameterized rectification.
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Nguyen, Philippe, Sooriyaarachchi, Jinani, Huang, Qianyu, and Baker Jr., Curtis L.
- Subjects
CONVOLUTIONAL neural networks ,ARTIFICIAL neural networks ,VISUAL cortex ,MATHEMATICAL continuum ,VISUAL perception ,WHITE noise ,SPATIAL orientation - Abstract
Neurons in the primary visual cortex respond selectively to simple features of visual stimuli, such as orientation and spatial frequency. Simple cells, which have phase-sensitive responses, can be modeled by a single receptive field filter in a linear-nonlinear model. However, it is challenging to analyze phase-invariant complex cells, which require more elaborate models having a combination of nonlinear subunits. Estimating parameters of these models is made additionally more difficult by cortical neurons' trial-to-trial response variability. We develop a simple convolutional neural network method to estimate receptive field models for both simple and complex visual cortex cells from their responses to natural images. The model consists of a spatiotemporal filter, a parameterized rectifier unit (PReLU), and a two-dimensional Gaussian "map" of the receptive field envelope. A single model parameter determines the simple vs. complex nature of the receptive field, capturing complex cell responses as a summation of homogeneous subunits, and collapsing to a linear-nonlinear model for simple type cells. The convolutional method predicts simple and complex cell responses to natural image stimuli as well as grating tuning curves. The fitted models yield a continuum of values for the PReLU parameter across the sampled neurons, showing that the simple/complex nature of cells can vary in a continuous manner. We demonstrate that complex-like cells respond less reliably than simple-like cells. However, compensation for this unreliability with noise ceiling analysis reveals predictive performance for complex cells proportionately closer to that for simple cells. Most spatial receptive field structures are well fit by Gabor functions, whose parameters confirm well-known properties of cat A17/18 receptive fields. Author summary: Methods for recording increasingly many visual cortex neurons are advancing rapidly, demanding new approaches to characterize diverse receptive fields. We present a compact convolutional neural network model of early cortical neurons, which is uniformly applicable to simple and complex cells, and whose parameters are straightforwardly interpretable and readily estimated from responses to natural image stimuli. This novel approach introduces a single estimated model parameter to capture the simple/complex nature of a neuron's receptive field, revealing a continuum of simple vs complex-like behaviour. We show that almost all complex-like cells exhibit a lower response reliability to repeated presentations of the same stimuli, compared to more reliable responses from simple-like cells. Accounting for this "noise ceiling" brings predictive performance for complex cells proportionately closer to that for simple cells. Using this model estimation approach with natural images, we evaluate findings from previous approaches that were restricted to simple-type cells and the use of grating or white noise stimuli, revealing a diversity of Gabor-like spatial receptive field shapes, which lie along a continuum of spatial bandwidths. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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23. Learning capabilities to resolve tilt-translation ambiguity in goldfish.
- Author
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Tadokoro, Shin, Shinji, Yusuke, Yamanaka, Toshimi, and Hirata, Yutaka
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MOTION detectors ,GOLDFISH ,LINEAR acceleration ,VESTIBULO-ocular reflex ,TRANSLATIONAL motion ,SPATIAL orientation - Abstract
Introduction: Spatial orientation refers to the perception of relative location and self-motion in space. The accurate formation of spatial orientation is essential for animals to survive and interact safely with their environment. The formation of spatial orientation involves the integration of sensory inputs from the vestibular, visual, and proprioceptive systems. Vestibular organs function as specialized head motion sensors, providing information regarding angular velocity and linear acceleration via the semicircular canals and otoliths, respectively. However, because forces arising from the linear acceleration (translation) and inclination relative to the gravitational axis (tilt) are equivalent, they are indistinguishable by accelerometers, including otoliths. This is commonly referred to as the tilt - translation ambiguity, which can occasionally lead to the misinterpretation of translation as a tilt. The major theoretical frameworks addressing this issue have proposed that the interpretation of tilt versus translation may be contingent on an animal's previous experiences of motion. However, empirical confirmation of this hypothesis is lacking. Methods: In this study, we conducted a behavioral experiment using goldfish to investigate how an animal's motion experience influences its interpretation of tilt vs. translation. We examined a reflexive eye movement called the vestibuloocular reflex (VOR), which compensatory-rotates the eyes in response to head motion and is known to reflect an animal's three-dimensional head motion estimate. Results: We demonstrated that the VORs of naïve goldfish do not differentiate between translation and tilt at 0.5 Hz. However, following prolonged visualtranslation training, which provided appropriate visual stimulation in conjunction with translational head motion, the VORs were capable of distinguishing between the two types of head motion within 3 h. These results were replicated using the Kalman filter model of spatial orientation, which incorporated the variable variance of process noise corresponding to the accumulated motion experience. Discussion: Based on these experimental and computational findings, we discuss the neural mechanism underlying the resolution of tilt-translation ambiguity within a context analogous to, yet distinct from, previous cross-axis VOR adaptations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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24. Towards Personally Relevant Navigation: The Differential Effects of Cognitive Style and Map Orientation on Spatial Knowledge Development.
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Park, Hannah, Dixit, Manish K., and Pariafsai, Fatemeh
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COGNITIVE styles ,SPATIAL orientation ,COGNITIVE maps (Psychology) ,NAVIGATION ,GLOBAL Positioning System ,SPATIAL ability - Abstract
Under emergencies such as floods and fires or during indoor navigation where cues from local landmarks and a Global Positioning System (GPS) are no longer available, the acquisition of comprehensive environmental representation becomes particularly important. Several studies demonstrated that individual differences in cognitive style might play an important role in creating a complete environmental representation and spatial navigation. However, this relationship between cognitive style and spatial navigation is not well researched. This study hypothesized that a specific type of map orientation (north-up vs. forward-up) might be more efficient for individuals with different cognitive styles. Forty participants were recruited to perform spatial tasks in a virtual maze environment to understand how cognitive style may relate to spatial navigation abilities, particularly the acquisition of survey and route knowledge. To measure survey knowledge, pointing direction tests and sketch map tests were employed, whereas, for route knowledge, the landmark sequencing test and route retracing test were employed. The results showed that both field-dependent and field-independent participants showed more accurate canonical organization in their sketch map task with a north-up map than with a forward-up map, with field-independent participants outperforming field-dependent participants in canonical organization scores. The map orientation did not influence the performance of Field-Independent participants on the pointing direct test, with field-dependent participants showing higher angular error with north-up maps. Regarding route knowledge, field-independent participants had more accurate responses in the landmark sequencing tests with a north-up map than with a forward-up map. On the other hand, field-dependent participants had higher accuracy in landmark sequencing tests in the forward-up map condition than in the north-up map condition. In the route retracing test, however, the map orientation had no statistically significant effect on different cognitive style groups. The results indicate that cognitive style may affect the relationship between map orientation and spatial knowledge acquisition. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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25. TACA-RNet: Tri-Axis Based Context-Aware Reverse Network for Multimodal Brain Tumor Segmentation.
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Kim, Hyunjin, Jo, Youngwan, Lee, Hyojeong, and Park, Sanghyun
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BRAIN tumors ,MAGNETIC resonance imaging ,CONVOLUTIONAL neural networks ,BRAIN anatomy ,SPATIAL orientation - Abstract
Brain tumor segmentation using Magnetic Resonance Imaging (MRI) is vital for clinical decision making. Traditional deep learning-based studies using convolutional neural networks have predominantly processed MRI data as two-dimensional slices, leading to the loss of contextual information. While three-dimensional (3D) convolutional layers represent an advancement, they have not fully exploited pathological information according to the three-axis nature of 3D MRI data—axial, coronal, and sagittal. Recognizing these limitations, we introduce a Tri-Axis based Context-Aware Reverse Network (TACA-RNet). This innovative approach leverages the unique 3D spatial orientations of MRI, learning crucial information on brain anatomy and pathology. We incorporated three specialized modules: a Tri-Axis Channel Reduction module for optimizing feature dimensions, a MultiScale Contextual Fusion module for aggregating multi-scale features and enhancing spatial discernment, and a 3D Axis Reverse Attention module for the precise delineation of tumor boundaries. The TACA-RNet leverages three specialized modules to enhance the understanding of tumor characteristics and spatial relationships within MRI data by fully utilizing its tri-axial structure. Validated on the Brain Tumor Segmentation Challenge 2018 and 2020 datasets, the TACA-RNet demonstrated superior performances over contemporary methodologies. This underscores the critical role of leveraging the three-axis structure of MRI to enhance segmentation accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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26. Functional impact of bilateral vestibular loss and the unexplained complaint of oscillopsia.
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Geisinger, Dario, Elyoseph, Zohar, Zaltzman, Roy, Mintz, Matti, and Gordon, Carlos R.
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VESTIBULAR apparatus diseases ,SPATIAL orientation ,VESTIBULO-ocular reflex ,EYE movements ,VISUAL acuity ,MEDICAL centers - Abstract
Introduction: The vestibulo-ocular reflex (VOR) stabilizes vision during head movements. VOR disorders lead to symptoms such as imbalance, dizziness, and oscillopsia. Despite similar VOR dysfunction, patients display diverse complaints. This study analyses saccades, balance, and spatial orientation in chronic peripheral and central VOR disorders, specifically examining the impact of oscillopsia. Methods: Participants involved 15 patients with peripheral bilateral vestibular loss (pBVL), 21 patients with clinically and genetically confirmed Machado-Joseph disease (MJD) who also have bilateral vestibular deficit, and 22 healthy controls. All pBVL and MJD participants were tested at least 9 months after the onset of symptoms and underwent a detailed clinical neuro-otological evaluation at the Dizziness and Eye Movements Clinic of the Meir Medical Center. Results: Among the 15 patients with pBVL and 21 patients with MJD, only 5 patients with pBVL complained of chronic oscillopsia while none of the patients with MJD reported this complaint. Comparison between groups exhibited significant differences in vestibular, eye movements, balance, and spatial orientation. When comparing oscillopsia with no-oscillopsia subjects, significant differences were found in the dynamic visual acuity test, the saccade latency of eye movements, and the triangle completion test. Discussion: Even though there is a significant VOR gain impairment in MJD with some subjects having less VOR gain than pBVL with reported oscillopsia, no individuals with MJD reported experiencing oscillopsia. This study further supports that subjects experiencing oscillopsia present a real impairment to stabilize the image on the retina, whereas those without oscillopsia may utilize saccade strategies to cope with it and may also rely on visual information for spatial orientation. Finding objective differences will help to understand the causes of the oscillopsia experience and develop coping strategies to overcome it. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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27. Lesson Study as a Professional Development Model for Teaching Spatial Ability in Primary STEM.
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Bufasi, Ergi, Čakāne, Ildze, Greitans, Karlis, Dudareva, Inese, and Namsone, Dace
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CAREER development ,MENTAL rotation ,SPATIAL orientation ,SPATIAL ability ,TEACHING models ,GOAL (Psychology) ,LESSON planning - Abstract
This study explores the efficacy of a professional development (PD) model that employs lesson study to teach spatial ability skills in primary STEM education. The structure of the PD supported the 'Insights' mechanism by focusing on visualisation, mental rotation, construction and deconstruction, and spatial orientation, which are vital for nurturing students' spatial abilities. The 'Motivation' mechanism was addressed through goal setting in lesson planning, motivating teachers to integrate spatial tasks into their curricula. Continuous feedback and practical support facilitated the 'Technique' mechanism, embedding learned skills into everyday teaching practices. Last, the 'Embed in Practice' mechanisms, including action planning and prompts, were effectively translated into classroom practices, evidencing the model's operational efficacy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
28. Constructing and storytelling: accommodating different play orientations in learning spatial thinking.
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Sonneveld, Leonie, Klapwijk, Remke M., and Stappers, Pieter Jan
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SPATIAL orientation ,SPATIAL ability ,CREATIVE ability in children ,STORYTELLING ,ETHNOLOGY research ,HOUSE construction ,EMPATHY - Abstract
Spatial ability is malleable and belongs in the preschool. For preschoolers, many analytical activities with one correct answer such as tangram have been developed. Less is known about employing open-ended design assignments to creatively practice spatial thinking. Little attention has been paid to the mutual qualitative differences between children when engaged in spatial thinking and insight in children's motivation is lacking. As design and play have much in common, our first study investigated play orientations during free play of 49 Dutch preschoolers during free play in a low and a high SES school. Participative interviews and observations in the construction and home corners of two schools uncovered different play orientations--construction and pretend play - and either a focus on open-ended objects or on defined objects. In a subsequent study, the influence of these play and object orientations on how children design was investigated. This study with 13 children also used generative design research methods grounded in ethnographic research and therapeutic practices. Using an empathic, story-based, open-ended design challenge, results showed that play-orientations of children influence the length and nature of the design activities as well as the design outcomes. Children with a pretend-play orientation are longer engaged and talk more about the character involved. They usually built organic structures with a variety of objects, while construction-oriented children mainly built sturdy and geometrical structures and mainly used open-ended objects. In all play orientations, spatial thinking was practiced and children were spatially challenged. For example, in all orientations difficulties arose around getting the character in out the structure, however, as different structures were build, the nature of these difficulties were also different. Open-ended design activities that contain characters and problems children can empathize with are a valuable addition to the palette of activities to develop spatial thinking in early classrooms. Our study shows that design activities stimulate children to practice spatial thinking in a creative context and have the ability to engage children with a pretend-play orientation who are otherwise less engaged in construction. The play-orientations and object-orientations are informative for research and the development of spatial educational interventions aiming at a diversity of learners. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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29. Spatial anxiety contributes to the dizziness-related handicap of adults with peripheral vestibular disease.
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Jáuregui-Renaud, Kathrine, García-Jacuinde, Dulce Maria, Bárcenas-Olvera, Simón Pedro, Gresty, Michael A., and Gutiérrez-Márquez, Aralia
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PERSPECTIVE taking ,MOTION sickness ,VESTIBULAR apparatus diseases ,BENIGN paroxysmal positional vertigo ,SUBJECTIVE stress ,SLEEP quality ,ANXIETY ,DISABILITIES - Abstract
In subjects with peripheral vestibular disease and controls, we assessed: 1. The relationship between spatial anxiety and perceived stress, and 2. The combined contribution of spatial anxiety, spatial perspective-taking, and individual cofactors to dizziness-related handicap. 309 adults participated in the study (153 with and 156 without peripheral vestibular disease), including patients with bilateral vestibular deficiency, unilateral deficiency (evolution <3 or ≥3 months), Meniere's disease, and Benign Paroxysmal Positional Vertigo. Assessments included: general health, personal habits, spatial anxiety (3-domains), perceived stress, spatial perspective-taking, dizziness-related handicap (3-domains), unsteadiness, sleep quality, motion sickness susceptibility, trait anxiety/ depression, state anxiety, depersonalization/derealization. After bivariate analyses, analysis of covariance was performed (p ≤ 0.05). Spatial anxiety was related to unsteadiness and perceived stress, with an inverse relationship with trait anxiety (ANCoVA, adjusted R² = 0.27-0.30, F = 17.945-20.086, p < 0.00001). Variability on perspective-taking was related to vestibular disease, trait and state anxiety, motion sickness susceptibility, and age (ANCoVA, adjusted R² = 0.18, F = 5.834, p < 0.00001). All domains of spatial anxiety contributed to the Physical domain of dizziness-related handicap, while the Navigation domain contributed to the Functional domain of handicap. Handicap variability was also related to unsteadiness, spatial perspective-taking, quality of sleep, and trait anxiety/depression (ANCoVA, adjusted R² = 0.66, F = 39.07, p < 0.00001). Spatial anxiety is related to perceived stress in adults both with and without vestibular disease, subjects with trait anxiety rated lower on spatial anxiety. State anxiety and acute stress could be helpful for recovery after peripheral vestibular lesion. Spatial anxiety and perspective-taking contribute to the Physical and Functional domains of dizziness-related handicap, possibly because it discourages behavior beneficial to adaptation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
30. LAGSwin: Local attention guided Swin-transformer for thermal infrared sports object detection.
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Meng, Hengran, Si, Shuqi, Mao, Bingfei, Zhao, Jia, and Wu, Liping
- Subjects
INFRARED imaging ,SPATIAL orientation ,THERMOGRAPHY ,VISIBLE spectra ,PHOTOTHERMAL effect ,SEMANTICS - Abstract
Compared with visible light images, thermal infrared images have poor resolution, low contrast, signal-to-noise ratio, blurred visual effects, and less information. Thermal infrared sports target detection methods relying on traditional convolutional networks capture the rich semantics in high-level features but blur the spatial details. The differences in physical information content and spatial distribution of high and low features are ignored, resulting in a mismatch between the region of interest and the target. To address these issues, we propose a local attention-guided Swin-transformer thermal infrared sports object detection method (LAGSwin) to encode sports objects' spatial transformation and orientation information. On the one hand, Swin-transformer guided by local attention is adopted to enrich the semantic knowledge of low-level features by embedding local focus from high-level features and generating high-quality anchors while increasing the embedding of contextual information. On the other hand, an active rotation filter is employed to encode orientation information, resulting in orientation-sensitive and invariant features to reduce the inconsistency between classification and localization regression. A bidirectional criss-cross fusion strategy is adopted in the feature fusion stage to enable better interaction and embedding features of different resolutions. At last, the evaluation and verification of multiple open-source sports target datasets prove that the proposed LAGSwin detection framework has good robustness and generalization ability. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Vision-based driver ear recognition and spatial reconstruction.
- Author
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Peng, Cheng, Liu, Jiang, Jiang, Tao, and Zhang, Xilong
- Subjects
SPATIAL orientation ,NOISE control ,EAR ,MAP projection ,TRAFFIC noise ,QUALITY control - Abstract
How to identify the ear hole more accurately and more quickly are critical for the active noise reduction in the road vehicle. Obscurations, causing by the long hair, the earphone, and some kind of caps, make the spatial location and orientation of the driver's ears almost impossible. To solve these two problems, a new method was proposed to replace the original image scaling detection by combining the Haar-like algorithm with the scale size of the variable detection window in the recognition process. A depth positioning camera is added to the ear recognition, which may offer more accurate point vectors for the driver's two ear holes. A simplified spatial reconstruction model was developed to assist the search when the piercing was occluded. After calculating the image-camera-cab projection mapping relationship, only four feature points are enough for the model's data requirement. The test results show that the detection Frame Per Second (FPS) was improved to 8.8, and the ear hole's positioning error is less than 0.1 cm. The proposed system can locate ear holes even with 100% obscurations. The research may have potential application as a front-end subsystem for the active noise reduction and voice interaction systems, improving the quality of acoustic control in cars. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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32. Dual-Channel Transverse Fields Radiofrequency Coils for 1.5 T Magnetic Resonance Imaging.
- Author
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Giovannetti, Giulio, Burov, Denis, Alecci, Marcello, Rollo, Rocco, and Galante, Angelo
- Subjects
MAGNETIC resonance imaging ,RADIO frequency ,STRIP transmission lines ,MUTUAL inductance ,SPATIAL orientation - Abstract
This theoretical study presents the design and analytical/numerical optimization of novel dual-channel transverse fields radiofrequency (RF) surface coils for 1.5 T Magnetic Resonance Imaging (MRI). The research explores a planar setup with two channels on a row with aligned spatial orientation of the RF coils, aiming to solve a common design drawback of single-channel transverse field RF coils: the reduced Field Of View (FOV) along the direction of the RF field. A significant challenge in this design is the efficient decoupling of two sets of transverse field RF coils to prevent mutual interference. Our modeling approach integrates thin wire theoretical modeling, magnetostatic computation for strip conductor coils, and their full-wave electromagnetic simulation. Key findings at 64 MHz demonstrate that strategic geometric placement among the two-channel RF coil and the introduction of geometrical asymmetry in the design of the individual RF coils does minimize the mutual inductance, paving the way for effective dual-channel MRI applications. This decoupling approach allows to enhance the FOV, providing a theoretical framework for the development of optimized dual-channel transverse field RF coil configurations. The current design was validated with full-wave numerical study at 64 MHz (
1 H, 1.5 T), has the potential to be extended at lower or higher frequencies, and the presence of lossy samples needs to be considered in the latter case. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
33. Individual differences in emerging adults' spatial abilities: What role do affective factors play?
- Author
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Desme, Carlos J., Dick, Anthony S., Hayes, Timothy B., and Pruden, Shannon M.
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SPATIAL ability ,TRANSITION to adulthood ,YOUNG adults ,PERSPECTIVE taking ,INDIVIDUAL differences ,SPATIAL orientation - Abstract
Spatial ability is defined as a cognitive or intellectual skill used to represent, transform, generate, and recall information of an object or the environment. Individual differences across spatial tasks have been strongly linked to science, technology, engineering, and mathematics (STEM) interest and success. Several variables have been proposed to explain individual differences in spatial ability, including affective factors such as one's confidence and anxiety. However, research is lacking on whether affective variables such as confidence and anxiety relate to individual differences in both a mental rotation task (MRT) and a perspective-taking and spatial orientation task (PTSOT). Using a sample of 100 college students completing introductory STEM courses, the present study investigated the effects of self-reported spatial confidence, spatial anxiety, and general anxiety on MRT and PTSOT. Spatial confidence, after controlling for effects of general anxiety and biological sex, was significantly related to performance on both the MRT and PTSOT. Spatial anxiety, after controlling for effects of general anxiety and biological sex, was not related to either PTSOT or MRT scores. Together these findings suggest some affective factors, but not others, contribute to spatial ability performance to a degree that merits advanced investigation in future studies. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
34. Three-Axis Vector Magnetometer with a Three-Dimensional Flux Concentrator.
- Author
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Chen, Shih-Jui, Hong, Der-Tai, Hsieh, Ping-Hsun, and Wang, Tse-Kang
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MAGNETOMETERS ,MAGNETIC flux ,SPATIAL orientation ,MAGNETIC fields ,SPATIAL ability ,SUPERCONDUCTING coils ,MAGNETIC sensors ,MAGNETIC cores - Abstract
This research proposes a magnetic field sensor with spatial orientation ability. Through the assistance of a magnetic flux concentrator, out-of-plane magnetic flux can be concentrated and guided into the planar magnetic cores of a fluxgate sensor. A printed circuit board is used to construct the basic planar structure, on which the proposed three-dimensional magnetic flux concentrator and magnetic cores are assembled. This reduces the alignment error of the coils and improves the reliability of the sensor. Three-axis sensing is achieved by using the second harmonic signals from selected sensing coil pairs. The magnetometer exhibits a linear range to 130 μT. At an excitation frequency of 50 kHz, the measured sensitivities are 257.1, 468.8, and 258.8 V/T for the X-, Y-, and Z-axis sensing modes, respectively. This sensor utilizes only one sensing mechanism for the vector field, making it suitable for IoT applications, especially for assessing mechanical posture or position. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Representational horizon and visual space orientation: An investigation into the role of visual contextual cues on spatial mislocalisations
- Author
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De Sá Teixeira, Nuno Alexandre, Freitas, Rodrigo Ribeiro, Silva, Samuel, Taliscas, Tiago, Mateus, Pedro, Gomes, Afonso, and Lima, João
- Published
- 2024
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- View/download PDF
36. The influence of representational gravity on spatial orientation: an eye movement study
- Author
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Yang, Tianqi, Guo, Yaning, Wang, Xianyang, Wu, Shengjun, Wang, Xiuchao, Wang, Hui, and Liu, Xufeng
- Published
- 2024
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37. Ambient and focal attention during complex problem-solving: preliminary evidence from real-world eye movement data.
- Author
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Yuxuan Guo, Pannasch, Sebastian, Helmert, Jens R., and Kaszowska, Aleksandra
- Subjects
PROTOCOL analysis (Cognition) ,EYE movements ,SPATIAL orientation ,VISUAL perception ,PROBLEM solving ,INFORMATION-seeking behavior - Abstract
Time course analysis of eye movements during free exploration of real-world scenes often reveals an increase in fixation durations together with a decrease in saccade amplitudes, which has been explained within the two visual systems approach, i.e., a transition from ambient to focal. Short fixations and long saccades during early viewing periods are classified as ambient mode of vision, which is concerned with spatial orientation and is related to simple visual properties such as motion, contrast, and location. Longer fixations and shorter saccades during later viewing periods are classified as focal mode of vision, which is concentrated in the foveal projection and is capable of object identification and its semantic categorization. While these findings are mainly obtained in the context of image exploration, the present study endeavors to investigate whether the same pattern of interplay between ambient and focal visual attention is deployed when people work on complex real-world tasks--and if so, when? Based on a re-analysis of existing data that integrates concurrent think aloud and eye tracking protocols, the present study correlated participants' internal thinking models to the parameters of their eye movements when they planned solutions to an open-ended design problem in a real-world setting. We hypothesize that switching between ambient and focal attentional processing is useful when solvers encounter difficulty compelling them to shift their conceptual direction to adjust the solution path. Individuals may prefer different attentional strategies for information-seeking behavior, such as ambient-to-focal or focal-to-ambient. The observed increase in fixation durations and decrease in saccade amplitudes during the periods around shifts in conceptual direction lends support to the postulation of the ambient-to-focal processing; however, focal-to-ambient processing is not evident. Furthermore, our data demonstrate that the beginning of a shift in conceptual direction is observable in eye movement behavior with a significant prolongation of fixation. Our findings add to the conclusions drawn from laboratory settings by providing preliminary evidence for ambient and focal processing characteristics in realworld problem-solving. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. A clinical 3D pointing test differentiates spatial memory deficits in dementia and bilateral vestibular failure.
- Author
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Gerb, J., Brandt, T., and Dieterich, M.
- Subjects
SPATIAL memory ,MEMORY disorders ,SPATIAL orientation ,DEMENTIA ,COGNITION disorders ,UNILATERAL neglect - Abstract
Background: Deficits in spatial memory, orientation, and navigation are often neglected early signs of cognitive impairment or loss of vestibular function. Real-world navigation tests require complex setups. In contrast, simple pointing at targets in a three-dimensional environment is a basic sensorimotor ability which provides an alternative measure of spatial orientation and memory at bedside. The aim of this study was to test the reliability of a previously established 3D-Real-World Pointing Test (3D-RWPT) in patients with cognitive impairment due to different neurodegenerative disorders, bilateral vestibulopathy, or a combination of both compared to healthy participants. Methods: The 3D-RWPT was performed using a static array of targets in front of the seated participant before and, as a transformation task, after a 90-degree body rotation around the yaw-axis. Three groups of patients were enrolled: (1) chronic bilateral vestibulopathy (BVP) with normal cognition (n = 32), (2) cognitive impairment with normal vestibular function (n = 28), and (3) combined BVP and cognitive impairment (n = 9). The control group consisted of age-matched participants (HP) without cognitive and vestibular deficits (n = 67). Analyses focused on paradigm-specific mean angular deviation of pointing in the azimuth (horizontal) and polar (vertical) spatial planes, of the preferred pointing strategy (egocentric or allocentric), and the resulting shape configuration of the pointing array relative to the stimulus array. Statistical analysis was performed using age-corrected ANCOVA-testing with Bonferroni correction and correlation analysis using Spearman's rho. Results: Patients with cognitive impairment employed more egocentric pointing strategies while patients with BVP but normal cognition and HP used more world-based solutions (pBonf 5.78 × 10-3**). Differences in pointing accuracy were only found in the azimuth plane, unveiling unique patterns where patients with cognitive impairment showed decreased accuracy in the transformation tasks of the 3D-RWPT (pBonf < 0.001***) while patients with BVP struggled in the post-rotation tasks (pBonf < 0.001***). Overall azimuth pointing performance was still adequate in some patients with BVP but significantly decreased when combined with a cognitive deficit. Conclusion: The 3D-RWPT provides a simple and fast measure of spatial orientation and memory. Cognitive impairment often led to a shift from world-based allocentric pointing strategy to an egocentric performance with less azimuth accuracy compared to age-matched controls. This supports the view that cognitive deficits hinder the mental buildup of the stimulus pattern represented as a geometrical form. Vestibular hypofunction negatively affected spatial memory and pointing performance in the azimuth plane. The most severe spatial impairments (angular deviation, figure frame configuration) were found in patients with combined cognitive and vestibular deficits. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Collective decision-making and spatial patterns in orientation of an endemic ungulate on the Tibetan Plateau.
- Author
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(严雪婷), Xueting Yan, (王旭), Xu Wang, (赵雨梦), Yumeng Zhao, (祝芹), Qin Zhu, (杨乐), Le Yang, and (李忠秋), Zhongqiu Li
- Subjects
SPATIAL orientation ,SWARM intelligence ,DECISION making ,VIDEO recording ,EQUUS ,UNGULATES - Abstract
Group living animals form striking aggregation patterns and display synchronization, polarization, and collective intelligence. Though many collective behavioral studies have been conducted on small animals like insects and fish, research on large animals is still rare due to the limited availability of field collective data. We used drones to record videos and analyzed the decision-making and behavioral spatial patterns in orientation of Kiang (Tibetan wild ass, Equus kiang). Leadership is unevenly distributed among Kiang, with the minority initiating majority behavior-shift decisions. Decisions of individual to join are driven by imitation between group members, and are largely dependent on the number of members who have already joined. Kiang respond to the behavior and position of neighbors through different strategies. They strongly polarize when moving, therefore adopting a linear alignment. When vigilant, orientation deviation increases as they form a tighter group. They remain scattered while feeding and, in that context, adopt a side-by-side alignment. This study reveals partially-shared decision-making among Kiang, whereby copying neighbors provides the wisdom to thrive in harsh conditions. This study also suggests that animals' spatial patterns in orientation depend largely on their behavioral states in achieving synchronization. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Factors of significance for the ability of fighter pilots to visually indicate the magnitude of roll tilt during simulated turns in a centrifuge.
- Author
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Brink, Andreas, Keramidas, Michail E., Tribukait, Arne, and Eiken, Ola
- Abstract
During coordinated flight and centrifugation, pilots show interindividual variability in perceived roll tilt. The study explored how this variability is related to perceptual and cognitive functions. Twelve pilots underwent three 6-min centrifugations on two occasions (G levels: 1.1G, 1.8G, and 2.5G; gondola tilts: 25°, 56°, and 66°). The subjective visual horizontal (SVH) was measured with an adjustable luminous line and the pilots gave estimates of experienced G level. Afterward, they were interrogated regarding the relationship between G level and roll tilt and adjusted the line to numerically mentioned angles. Generally, the roll tilt during centrifugation was underestimated, and there was a large interindividual variability. Both knowledge on the relationship between G level and bank angle, and ability to adjust the line according to given angles contributed to the prediction of SVH in a multiple regression model. However, in most cases, SVH was substantial smaller than predictions based on specific abilities. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. DNA mechanocapsules for programmable piconewton responsive drug delivery.
- Author
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Velusamy, Arventh, Sharma, Radhika, Rashid, Sk Aysha, Ogasawara, Hiroaki, and Salaita, Khalid
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DNA ,DEXTRAN ,CELL receptors ,SPATIAL orientation ,TETRAHEDRA ,DISEASE progression ,POLYMERSOMES - Abstract
The mechanical dysregulation of cells is associated with a number of disease states, that spans from fibrosis to tumorigenesis. Hence, it is highly desirable to develop strategies to deliver drugs based on the "mechanical phenotype" of a cell. To achieve this goal, we report the development of DNA mechanocapsules (DMC) comprised of DNA tetrahedrons that are force responsive. Modeling shows the trajectory of force-induced DMC rupture and predicts how applied force spatial position and orientation tunes the force-response threshold. DMCs functionalized with adhesion ligands mechanically denature in vitro as a result of cell receptor forces. DMCs are designed to encapsulate macromolecular cargos such as dextran and oligonucleotide drugs with minimal cargo leakage and high nuclease resistance. Force-induced release and uptake of DMC cargo is validated using flow cytometry. Finally, we demonstrate force-induced mRNA knockdown of HIF-1α in a manner that is dependent on the magnitude of cellular traction forces. These results show that DMCs can be effectively used to target biophysical phenotypes which may find useful applications in immunology and cancer biology. The mechanical dysregulation of cells is associated with several diseases and strategies to deliver drugs based on the "mechanical phenotype" of a cell are desirable. Here, the authors design and characterize DNA mechanocapsules comprised of DNA tetrahedrons that are force responsive, and showed they can encapsulate macromolecular cargo and release it upon application of force. [ABSTRACT FROM AUTHOR]
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- 2024
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42. Sex and gender correlates of sexually polymorphic cognition.
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Cartier, Louis, Guérin, Mina, Saulnier, Fanny, Cotocea, Ioana, Mohammedi, Amine, Moussaoui, Fadila, Kheloui, Sarah, and Juster, Robert-Paul
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GENDER ,GENDER role ,GENDER nonconformity ,GENDER identity ,SPATIAL orientation ,MENTAL orientation ,COMPREHENSION in children ,PROGESTERONE receptors - Abstract
Background: Sexually polymorphic cognition (SPC) results from the interaction between biological (birth-assigned sex (BAS), sex hormones) and socio-cultural (gender identity, gender roles, sexual orientation) factors. The literature remains quite mixed regarding the magnitude of the effects of these variables. This project used a battery of classic cognitive tests designed to assess the influence of sex hormones on cognitive performance. At the same time, we aimed to assess the inter-related and respective effects that BAS, sex hormones, and gender-related factors have on SPC. Methods: We recruited 222 adults who completed eight cognitive tasks that assessed a variety of cognitive domains during a 150-min session. Subgroups were separated based on gender identity and sexual orientation and recruited as follows: cisgender heterosexual men (n = 46), cisgender non-heterosexual men (n = 36), cisgender heterosexual women (n = 36), cisgender non-heterosexual women (n = 38), gender diverse (n = 66). Saliva samples were collected before, during, and after the test to assess testosterone, estradiol, progesterone, cortisol, and dehydroepiandrosterone. Psychosocial variables were derived from self-report questionnaires. Results: Cognitive performance reflects sex and gender differences that are partially consistent with the literature. Interestingly, biological factors seem to better explain differences in male-typed cognitive tasks (i.e., spatial), while psychosocial factors seem to better explain differences in female-typed cognitive tasks (i.e., verbal). Conclusion: Our results establish a better comprehension of SPC over and above the effects of BAS as a binary variable. We highlight the importance of treating sex as a biological factor and gender as a socio-cultural factor together since they collectively influence SPC. Plain Language Summary: Many studies show sex differences in cognitive abilities. In general, women outperform men in verbal tasks and fine motor skills, while men outperform women in spatial orientation and mental rotation tasks. These differences underlie research on sexually polymorphic cognition, a concept influenced by sex hormones (estradiol, progesterone, and testosterone) as well as birth-assigned sex. In addition to these biological factors, socio-cultural gender factors such as gender identity (the gender we feel and embody), gender roles (masculine and feminine expressions based on stereotypes), as well as sexual orientation are all known to influence cognition as well. We provide a broader understanding by accounting for both sex and gender factors. Our team recruited 222 adults separated into 5 sub-groups based on birth-assigned sex, gender identity, and sexual orientation. Each participant completed eight sexually polymorphic cognitive tasks. In this 150-min experimental protocol, saliva samples were collected before, during, and after the test to assess testosterone, estradiol, progesterone, cortisol, and dehydroepiandrosterone. Psychosocial variables were derived from self-report questionnaires. Results showed that spatial cognition was better explained by biological sex factors, while verbal cognition was better explained by socio-cultural gender factors. Taken together, our findings demonstrate the importance of considering sex-based and gender-based factors collectively and, respectively, when studying sex differences in cognition. Highlights: Sex differences in cognition have been extensively studied but remain unclear Incorporating sex and gender factors in cognitive studies is essential Inclusion of sexual and gender diversity further explain cognitive sex differences Contribution of each sex and gender factor depend on the cognitive function observed Spatial cognition appears more sexed, while verbal cognition appears more gendered. [ABSTRACT FROM AUTHOR]
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- 2024
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43. Acta Plane—A New Reference for Virtual Orientation of Cone Beam Computed Tomography Scans: A Pilot Study.
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Sanders-Mello, Fernanda, de Menezes, Luciane Macedo, Puetter, Ursula Tavares, Azeredo, Fabiane, Griekspoor, Tina Cornelia Antonieke, de Windt, Sergio, Livas, Christos, Jonkman, Ronald E. G., Rozema, Frederik Reinder, and Koolstra, Jan Harm
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CONE beam computed tomography ,SURFACE plates ,INTRACLASS correlation ,DENTAL students - Abstract
Introduction: Cone Beam Computed Tomography (CBCT) scans should be digitally oriented using a reference plane before being evaluated for patient growth and treatment outcome. Current orientation planes are usually dependent on the Porion points. Using more reliable landmarks than the Porion, we introduce the Acta plane and investigate its reliability as an alternative reference plane for cases in which the Porion point is inaccessible. Methods: To test its reliability, a dental student and an orthodontist located sixteen skeletal and dental landmarks in sixteen CBCT scans before and after reorientation. Also, four measurements were calculated based on these landmarks' coordinates. The reorientation of these CBCT scans with the Acta plane was performed by another dental student. The Intraclass Correlation Coefficient (ICC) was calculated before and after orientation, as well as the intra and inter-examiner. The data were tested for significance through the Shapiro–Wilk test with a threshold set at 0.05. Through the ICC variation of the points' coordinates, this article also evaluated the reliability of this plane with the t-paired and exact-sign tests. Results: The identification of landmarks was more reliable in the reoriented CBCT images than in the original images, with a significant increase of 0.012 in the median of the ICC. Linear and angular measures showed no significant differences between groups. Conclusion: This plane is a reliable alternative for the orientation of CBCT images. The design of the Acta plane might allow the use of a smaller field of view and, consequently, a reduction in the radiation dose. [ABSTRACT FROM AUTHOR]
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- 2024
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44. MODEL ANALYSIS OF SOMATOGRAVIC ILLUSION IN ACCIDENTS RELATED TO A GO-AROUND.
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Clark, Torin, Newman, Michael, Mumaw, Randall, Houben, Mark, and Groen, Eric
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SPACE perception ,VESTIBULAR apparatus ,SPATIAL orientation ,MODEL airplanes ,DATA recorders & recording ,AIRCRAFT accidents - Abstract
BACKGROUND: Sustained aircraft forward acceleration can often lead pilots to have an illusory sense that the aircraft is pitching. Known as the somatogravic illusion, this can occur during a "go-around" maneuver when a landing approach is aborted. The resulting pilot spatial disorientation can coincide with incorrect pilot control inputs which can lead to an accident due to go-arounds often occurring at low altitudes. Conceptually, it is thought the somatogravic illusion occurs due to the otoliths of the vestibular system (and other graviceptors) being unable to distinguish between inertial acceleration and gravity. However, this is difficult to quantitatively capture during piloted aircraft flight. Computational models of human spatial orientation perception offer a means of studying the somatogravic illusion. OVERVIEW: Here, we applied a computational "observer" model to two inflight go-around scenarios in which the somatogravic illusion was thought to have potentially occurred. Specifically, the flight data recordings of the aircraft motion trajectories were processed to serve as inputs to the computational model. The model mimics the mechanisms which the brain is thought to use to perceive self-orientation. By inputting the aircraft motions which the pilots were exposed to, the models can provide a prediction of the pilots' perceptions of aircraft orientation and motion during the go-around maneuvers. Comparing the model predictions of pilot perception to actual aircraft orientation can help to quantitatively identify the occurrence of the somatogravic illusion. DISCUSSION: We aim to show the potential for applying a computational model to goaround flight maneuvers to better understand the somatogravic illusion. Comparing two flight scenarios will help identify commonalities which may occur leading to spatial disorientation during go-arounds. Studying previous flight scenarios, such as these, will help to elucidate potential means for preventing future spatial disorientation accidents. Learning Objectives 1. Describe the mathematical mechanisms involved in modeling human spatial orientation perception. 2. Understand the quantification of the somatogravic illusion in real flight data using computational modeling approaches. [ABSTRACT FROM AUTHOR]
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- 2024
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