scholarly journals Pupil responses associated with the perception of gravitational vertical under directional optic flows

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joo Hyun Park ◽  
Sung Ik Cho ◽  
June Choi ◽  
JungHyun Han ◽  
Yoon Chan Rah
Keyword(s):  
Fine Tuning ◽  
Gravity Perception ◽  
Cognitive Demands ◽  
Head Mounted Display ◽  
Rotational Flows ◽  
Visual Vertical ◽  
Optic Flows ◽  
The Difference ◽  
Gravitational Vertical ◽  
Healthy Participants

AbstractThis study assessed the pupil responses in the sensory integration of various directional optic flows during the perception of gravitational vertical. A total of 30 healthy participants were enrolled with normal responses to conventional subjective visual vertical (SVV) which was determined by measuring the difference (error angles) between the luminous line adjusted by the participants and the true vertical. SVV was performed under various types of rotational (5°/s, 10°/s, and 50°/s) and straight (5°/s and 10°/s) optic flows presented via a head-mounted display. Error angles (°) of the SVV and changes in pupil diameters (mm) were measured to evaluate the changes in the visually assessed subjective verticality and related cognitive demands. Significantly larger error angles were measured under rotational optic flows than under straight flows (p < 0.001). The error angles also significantly increased as the velocity of the rotational optic flow increased. The pupil diameter increased after starting the test, demonstrating the largest diameter during the final fine-tuning around the vertical. Significantly larger pupil changes were identified under rotational flows than in straight flows. Pupil changes were significantly correlated with error angles and the visual analog scale representing subjective difficulties during each test. These results suggest increased pupil changes for integrating more challenging visual sensory inputs in the process of gravity perception.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

It Keeps Me Seeking

2018 ◽  
Author(s):  
Andrew Briggs ◽  
Hans Halvorson ◽  
Andrew Steane
Keyword(s):  
Evolutionary Biology ◽  
Quantum Physics ◽  
Natural World ◽  
Theological Reflection ◽  
Fine Tuning ◽  
Good Argument ◽  
The Difference ◽  
Argument From Design ◽  
Relationship Of

Two scientists and a philosopher aim to show how science both enriches and is enriched by Christian faith. The text is written around four themes: 1. God is a being to be known, not a hypothesis to be tested; 2. We set a high bar on what constitutes good argument; 3. Uncertainty is OK; 4. We are allowed to open up the window that the natural world offers us. This is not a work of apologetics. Rather, the text takes an overview of various themes and gives reactions and responses, intended to place science correctly as a valued component of the life of faith. The difference between philosophical analysis and theological reflection is expounded. Questions of human identity are addressed from philosophy, computer science, quantum physics, evolutionary biology and theological reflection. Contemporary physics reveals the subtle and open nature of physical existence, and offers lessons in how to learn and how to live with incomplete knowledge. The nature and role of miracles is considered. The ‘argument from design’ is critiqued, especially arguments from fine-tuning. Logical derivation from impersonal facts is not an appropriate route to a relationship of mutual trust. Mainstream evolutionary biology is assessed to be a valuable component of our understanding, but no exploratory process can itself fully account for the nature of what is discovered. To engage deeply in science is to seek truth and to seek a better future; it is also an activity of appreciation, as one may appreciate a work of art.

Walking by Thinking: The Brainwaves Are Crucial, Not the Muscles!

2006 ◽  
Vol 15 (5) ◽  
pp. 500-514 ◽  
Author(s):  
Robert Leeb ◽  
Claudia Keinrath ◽  
Doron Friedman ◽  
Christoph Guger ◽  
Reinhold Scherer ◽  
...  
Keyword(s):  
Communication Channel ◽  
Muscular Activity ◽  
Proof Of Concept ◽  
Closed Loop System ◽  
Head Mounted Display ◽  
Eeg Recordings ◽  
Sensorimotor Rhythms ◽  
Electroencephalogram Eeg ◽  
Healthy Participants

Healthy participants are able to move forward within a virtual environment (VE) by the imagination of foot movement. This is achieved by using a brain-computer interface (BCI) that transforms thought-modulated electroencephalogram (EEG) recordings into a control signal. A BCI establishes a communication channel between the human brain and the computer. The basic principle of the Graz-BCI is the detection and classification of motor-imagery-related EEG patterns, whereby the dynamics of sensorimotor rhythms are analyzed. A BCI is a closed-loop system and information is visually fed back to the user about the success or failure of an intended movement imagination. Feedback can be realized in different ways, from a simple moving bar graph to navigation in VEs. The goals of this work are twofold: first, to show the influence of different feedback types on the same task, and second, to demonstrate that it is possible to move through a VE (e.g., a virtual street) without any muscular activity, using only the imagination of foot movement. In the presented work, data from BCI feedback displayed on a conventional monitor are compared with data from BCI feedback in VE experiments with a head-mounted display (HMD) and in a high immersive projection environment (Cave). Results of three participants are reported to demonstrate the proof-of-concept. The data indicate that the type of feedback has an influence on the task performance, but not on the BCI classification accuracy. The participants achieved their best performances viewing feedback in the Cave. Furthermore the VE feedback provided motivation for the subjects.

scholarly journals The Wisdom to Know the Difference

2016 ◽  
Vol 27 (12) ◽  
pp. 1651-1659 ◽  
Author(s):  
Simon J. Haines ◽  
John Gleeson ◽  
Peter Kuppens ◽  
Tom Hollenstein ◽  
Joseph Ciarrochi ◽  
...  
Keyword(s):  
Emotion Regulation ◽  
Adaptive Strategy ◽  
Well Being ◽  
Opposite Pattern ◽  
Regulation Strategies ◽  
The Difference ◽  
The Right ◽  
Ecological Momentary ◽  
Momentary Assessment ◽  
Healthy Participants

The ability to regulate emotions is central to well-being, but healthy emotion regulation may not merely be about using the “right” strategies. According to the strategy-situation-fit hypothesis, emotion-regulation strategies are conducive to well-being only when used in appropriate contexts. This study is the first to test the strategy-situation-fit hypothesis using ecological momentary assessment of cognitive reappraisal—a putatively adaptive strategy. We expected people who used reappraisal more in uncontrollable situations and less in controllable situations to have greater well-being than people with the opposite pattern of reappraisal use. Healthy participants ( n = 74) completed measures of well-being in the lab and used a smartphone app to report their use of reappraisal and perceived controllability of their environment 10 times a day for 1 week. Results supported the strategy-situation-fit hypothesis. Participants with relatively high well-being used reappraisal more in situations they perceived as lower in controllability and less in situations they perceived as higher in controllability. In contrast, we found little evidence for an association between greater well-being and greater mean use of reappraisal across situations.

scholarly journals Enhancing the CRI and lumen output for the 6600 K WLED with convex-dual-layer remote phosphor geometry by applying red-emitting MGSR3SI2O8:EU2+,MN2+ phosphor

2020 ◽  
Vol 10 (4) ◽  
pp. 3501
Author(s):  
Thuc Minh Bui ◽  
Nguyen Thi Phuong Loan ◽  
Phan Xuan Le ◽  
Nguyen Doan Quoc Anh ◽  
Anh Tuan Le ◽  
...  
Keyword(s):  
White Light ◽  
Luminous Efficiency ◽  
Fine Tuning ◽  
Color Temperature ◽  
Single Chip ◽  
Phosphor Material ◽  
Color Design ◽  
Maximum Value ◽  
The Difference ◽  
Color Rendering

The traditional white LED product established with a single chip and a single phosphor results in a low color rendering index (CRI). The upgrade of LED package is comprised of two chips and one phosphor material and gives the higher CRI while keeping high luminous efficiency. Based on previous findings, the research paper performs the application of the two chips and two phosphors to enhance the color tunability of LEDs with different amounts and intensities of the two employed phosphors. Additionally, a color design model is built to serve the purpose of bettering the color fine-tuning of the white-light LED module. The maximum value of the difference between the measured CIE 1931 color coordinates and that of the simulated model is approximately 0.0063 around the 6600 K correlated color temperature (CCT). From the results, this study offers a quick approach to achieve the color fine tuning of a white-light LED module with a high CRI and luminous efficiency.

scholarly journals Controlling Molecular Assembly and Charge Transport of N-Type Organic Semiconductors with Sterically Demanding Substituents

2020 ◽  
Author(s):  
Craig Yu ◽  
Naoya Kojima ◽  
Shohei Kumagai ◽  
Tadanori Kurosawa ◽  
Hiroyuki Ishii ◽  
...  
Keyword(s):  
Charge Transport ◽  
Organic Semiconductors ◽  
Field Effect Transistors ◽  
Molecular Assembly ◽  
Fine Tuning ◽  
Organic Field Effect Transistors ◽  
Molecular Assemblies ◽  
Design And Synthesis ◽  
Sterically Demanding ◽  
The Difference

Abstract Benzo[de]isoquinolino[1,8-gh]quinolinetetracarboxylic diimide (BQQDI) n-type organic semiconductors demonstrate unique multi-fold intermolecular hydrogen-bonding interactions that lead to excellent aggregated structures, charge transports, and electron mobility. However, the robust intermolecular anchoring of BQQDI presents challenges for further fine-tuning molecular assemblies and organic semiconductor properties. Herein, we report the design and synthesis of two BQQDI derivatives with sterically demanding phenyl- and cyclohexyl-substituted BQQDI (Ph–BQQDI and Cy6–BQQDI), where the two organic semiconductors show distinct molecular assemblies and degrees of intermolecular orbital overlaps. In addition, the difference in their packing motifs led to strikingly different band structures that give rise to contrasting charge-transport capabilities. As a result, Cy6–BQQDI shows excellent transistor performances in both single-crystalline and polycrystalline thin-film organic field-effect transistors.

scholarly journals Validity and reliability of standing balance control measurement on the left unilateral spatial neglect model

2021 ◽  
Vol 15 (3) ◽  
pp. 167-179
Author(s):  
Abdul C. Meidian ◽  
Song Yige ◽  
Syahmirza I. Lesmana ◽  
Kazu Amimoto
Keyword(s):  
Postural Balance ◽  
Balance Control ◽  
Standing Balance ◽  
Spatial Neglect ◽  
Validity And Reliability ◽  
Control Measurement ◽  
Unilateral Spatial Neglect ◽  
Head Mounted Display ◽  
The Right ◽  
Healthy Participants

BACKGROUND: The present study developed a head-mounted display with the visual direction of a web camera modified to the right as a left unilateral spatial neglect (USN) model with respect to postural balance control. AIM: We aimed to estimate the validity and reliability of center of pressure (CoP) measurements in static standing balance (SSB) and dynamic standing balance (DSB) of healthy participants were using the USN model and to examine whether this model's use influenced postural balance control. METHOD: A portable CoP force plate was used to quantify postural balance control in 64 healthy participants as the model. The CoP displacement of the non-USN and USN models in the medial-lateral (ML) and anterior-posterior (AP) planes, CoP length, and bilateral load ratio in SSB and DSB to the right (R) and left (L) were evaluated. RESULTS: Regression analysis indicated that most CoP measurements have excellent concurrent validity. Bland–Altman plots showed good agreement between the non-USN and USN models in the CoP measurements. Test-retest reliability estimation between two times measurements varied in the frontal and sagittal planes. A Comparison of the results demonstrated that the CoP-AP and CoP length changed (-1.40% and 7.67%, respectively) significantly in SSB (P<0.05). Moreover, the CoP-AP changed very significantly in DSB-R and DSB-L (-1.50% and 1.86%, respectively) in opposite directions (P<0.01) when the subjects performed as the model. CONCLUSION: CoP measurements are valid and reliable to quantify standing balance control in both non-USN and USN models that appear to modulate changes in postural adaptation and adjustment.

scholarly journals A Subjective Study on User Perception Aspects in Virtual Reality

2019 ◽  
Vol 9 (16) ◽  
pp. 3384 ◽  
Author(s):  
Huyen T. T. Tran ◽  
Nam P. Ngoc ◽  
Cuong T. Pham ◽  
Yong Ju Jung ◽  
Truong Cong Thang
Keyword(s):  
Virtual Reality ◽  
Perceptual Quality ◽  
Affecting Factors ◽  
Head Mounted Display ◽  
Number Of Factors ◽  
Significant Difference ◽  
Subjective Experiment ◽  
The Difference ◽  
Subjective Study

Three hundred and sixty degree video is becoming more and more popular on the Internet. By using a Head-Mounted Display, 360-degree video can render a Virtual Reality (VR) environment. However, it is still a big challenge to understand Quality of Experience (QoE) of 360-degree video since user experience during watching 360-degree video is a very complex phenomenon. In this paper, we aim to investigate four QoE aspects of 360-degree video, namely, perceptual quality, presence, cybersickness, and acceptability. In addition, four key QoE-affecting factors of encoding parameters, content motion, rendering device, and rendering mode are considered in our study. To the best of our knowledge, this is the first work that covers a large number of factors and QoE aspects of 360-degree video. In this study, a subjective experiment is conducted using 60 video versions generated from three original 360-degree videos. Based on statistical analysis of the obtained results, various findings on the impacts of the factors on the QoE aspects are provided. In particular, regarding the impacts of encoding parameters, it is found that the difference of QoE is negligible between video versions encoded at 4 K and 2.5 K resolutions. Also, it is suggested that 360-degree video should not be encoded at HD resolution or lower when watching in VR mode using Head Mounted Display. In addition, the bitrate for good QoE varies widely across different video contents. With respect to the content motion factor, its impact is statistically significant on the perceptual quality, presence, and cybersickness. In a comparison of two rendering device sets used in this study, there is no statistically significant difference found for the acceptability and cybersickness. However, the differences of the perceptual quality and presence are indicated to be statistically significant. Regarding the rendering mode, a comparison between VR and non-VR modes is also conducted. Although the non-VR mode always achieves higher perceptual quality scores and higher acceptability rates, more than a half of the viewers prefer the VR mode to the non-VR mode when watching versions encoded at the resolutions of fHD or higher. By contrast, the non-VR mode is preferred at the HD resolution.

Skin, Veins and Legs

Phlebologie ◽  
2011 ◽  
Vol 40 (06) ◽  
pp. 344-355 ◽  
Author(s):  
H.A.M. Neumann
Keyword(s):  
Plasma Proteins ◽  
Varicose Veins ◽  
Venous Pressure ◽  
Compression Therapy ◽  
Fine Tuning ◽  
Physical Parameters ◽  
Interface Pressure ◽  
Symptom Complex ◽  
The Difference ◽  
Physical Laws

SummarySkin, veins and legs are the three ingredients which compose together the symptom complex know as chronic venous insufficiency (CVI). High ambulatory venous pressure is transferred by simple physical laws to the skin microcirculation. The capillaries are not resistant to this high pressure and will leak water, erythrocytes and plasma proteins into the in-terstitium. The result is oedema, pigmentation, sclerosis, inflammation and ulceration. Although many forms of intervention for incompetent veins are available, compression therapy is still the cornerstone in the treatment of CVI. Beside the interface pressure, the stiffness of the compression material is essential. By increasing the stiffness the difference in pressure during walking increases and with this the massage effect of the therapy.Thermo-ablation is the treatment for varicose veins today. Knowledge about the development and transfer of the intravascular heat is essential to understand this treatment. New experiments, specially about steam development from the heat source in the blood are of great importance for the success rate. Fine tuning in those physical parameters is needed to optimally this treatment.

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