keyword
MENU ▼
Read by QxMD icon Read
search

physiology of vision

keyword
https://www.readbyqxmd.com/read/28212157/current-approaches-to-myopia-control
#1
Seo Wei Leo
PURPOSE OF REVIEW: Myopia is a global problem, being particularly prevalent in the urban areas of east and southeast Asia. In addition to the direct economic and social burdens, associated ocular complications may lead to substantial vision loss. With prevalence of myopia above 80% and high myopia over 20%, it is crucial to control myopia. The aim of this review to is provide an update on the interventions to slow the onset of myopia and retard its progression. RECENT FINDINGS: The epidemic of myopia is characterized by increasingly early onset, combined with high myopia progression rates...
February 15, 2017: Current Opinion in Ophthalmology
https://www.readbyqxmd.com/read/28195004/physiological-modeling-for-detecting-degree-of-perception-of-a-color-deficient-person
#2
T Rajalakshmi, Shanthi Prince
Physiological modeling of retina plays a vital role in the development of high-performance image processing methods to produce better visual perception. People with normal vision have an ability to discern different colors. The situation is different in the case of people with color blindness. The aim of this work is to develop a human visual system model for detecting the level of perception of people with red, green and blue deficiency by considering properties like luminance, spatial and temporal frequencies...
February 1, 2017: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
https://www.readbyqxmd.com/read/28193822/comparative-system-identification-of-flower-tracking-performance-in-three-hawkmoth-species-reveals-adaptations-for-dim-light-vision
#3
Anna L Stöckl, Klara Kihlström, Steven Chandler, Simon Sponberg
Flight control in insects is heavily dependent on vision. Thus, in dim light, the decreased reliability of visual signal detection also prompts consequences for insect flight. We have an emerging understanding of the neural mechanisms that different species employ to adapt the visual system to low light. However, much less explored are comparative analyses of how low light affects the flight behaviour of insect species, and the corresponding links between physiological adaptations and behaviour. We investigated whether the flower tracking behaviour of three hawkmoth species with different diel activity patterns revealed luminance-dependent adaptations, using a system identification approach...
April 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28193821/insect-photoreceptor-adaptations-to-night-vision
#4
REVIEW
Anna Honkanen, Esa-Ville Immonen, Iikka Salmela, Kyösti Heimonen, Matti Weckström
Night vision is ultimately about extracting information from a noisy visual input. Several species of nocturnal insects exhibit complex visually guided behaviour in conditions where most animals are practically blind. The compound eyes of nocturnal insects produce strong responses to single photons and process them into meaningful neural signals, which are amplified by specialized neuroanatomical structures. While a lot is known about the light responses and the anatomical structures that promote pooling of responses to increase sensitivity, there is still a dearth of knowledge on the physiology of night vision...
April 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28193817/behavioural-and-physiological-limits-to-vision-in-mammals
#5
REVIEW
Greg D Field, Alapakkam P Sampath
Human vision is exquisitely sensitive-a dark-adapted observer is capable of reliably detecting the absorption of a few quanta of light. Such sensitivity requires that the sensory receptors of the retina, rod photoreceptors, generate a reliable signal when single photons are absorbed. In addition, the retina must be able to extract this information and relay it to higher visual centres under conditions where very few rods signal single-photon responses while the majority generate only noise. Critical to signal transmission are mechanistic optimizations within rods and their dedicated retinal circuits that enhance the discriminability of single-photon responses by mitigating photoreceptor and synaptic noise...
April 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28176941/bioglass-implant-coating-interactions-in-synthetic-physiological-fluids-with-varying-degrees-of-biomimicry
#6
A C Popa, G E Stan, M A Husanu, I Mercioniu, L F Santos, H R Fernandes, Jmf Ferreira
Synthetic physiological fluids are currently used as a first in vitro bioactivity assessment for bone grafts. Our understanding about the interactions taking place at the fluid-implant interface has evolved remarkably during the last decade, and does not comply with the traditional International Organization for Standardization/final draft International Standard 23317 protocol in purely inorganic simulated body fluid. The advances in our knowledge point to the need of a true paradigm shift toward testing physiological fluids with enhanced biomimicry and a better understanding of the materials' structure-dissolution behavior...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28155698/the-biomechanical-significance-of-pulley-on-binocular-vision
#7
Hongmei Guo, Zhipeng Gao, Weiyi Chen
BACKGROUND: Pulleys have been reported as the functional origins of the rectus extraocular muscles (EOMs). However, biomechanical significance of pulleys on binocular vision has not been reported. METHODS: Three eye movement models, i.e., non-pulley model, passive-pulley model, and active-pulley model, are used to simulate the horizontal movement of the eyes from the primary position to the left direction in the range of 1°-30°. The resultant forces of six EOMs along both orthogonal directions (i...
December 28, 2016: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28148613/delirium-in-trauma-patients-prevalence-and-predictors
#8
Kathryn T Von Rueden, Breighanna Wallizer, Paul Thurman, Karen McQuillan, Tiffany Andrews, Jennifer Merenda, Heesook Son
BACKGROUND: Delirium is associated with increased mortality, morbidity, hospital costs, and postdischarge cognitive dysfunction. Most research focuses on nontrauma patients receiving mechanical ventilation in the intensive care unit. OBJECTIVES: To determine the prevalence and predictors of delirium in trauma patients residing in intensive and intermediate care units of an academic medical center. METHODS: Trauma patients were screened for delirium by using the Confusion Assessment Method for the Intensive Care Unit...
February 2017: Critical Care Nurse
https://www.readbyqxmd.com/read/28146554/fundamental-activity-constraints-lead-to-specific-interpretations-of-the-connectome
#9
Jannis Schuecker, Maximilian Schmidt, Sacha J van Albada, Markus Diesmann, Moritz Helias
The continuous integration of experimental data into coherent models of the brain is an increasing challenge of modern neuroscience. Such models provide a bridge between structure and activity, and identify the mechanisms giving rise to experimental observations. Nevertheless, structurally realistic network models of spiking neurons are necessarily underconstrained even if experimental data on brain connectivity are incorporated to the best of our knowledge. Guided by physiological observations, any model must therefore explore the parameter ranges within the uncertainty of the data...
February 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28138125/face-transplant-in-an-advanced-neurofibromatosis-type-1-patient
#10
Łukasz Krakowczyk, Adam Maciejewski, Cezary Szymczyk, Krzysztof Oleś, Stanisław Półtorak
BACKGROUND The human face is a one-of-a-kind structure with unique morphology, complexity, and function, in which different subunits are not even similar to other parts of the body. Therefore, extended complex deficits of the face are usually difficult to reconstruct, and autologous tissue restoration is generally not able to give a satisfactory aesthetic and functional outcome. The main goal of face allotransplantation is to restore symmetry, contour, and appearance as well as function of the face, especially control of orbicularis oculi and oris muscle physiology...
January 31, 2017: Annals of Transplantation: Quarterly of the Polish Transplantation Society
https://www.readbyqxmd.com/read/28135308/individual-objective-and-subjective-fixation-disparity-in-near-vision
#11
Wolfgang Jaschinski
Binocular vision refers to the integration of images in the two eyes for improved visual performance and depth perception. One aspect of binocular vision is the fixation disparity, which is a suboptimal condition in individuals with respect to binocular eye movement control and subsequent neural processing. The objective fixation disparity refers to the vergence angle between the visual axes, which is measured with eye trackers. Subjective fixation disparity is tested with two monocular nonius lines which indicate the physical nonius separation required for perceived alignment...
2017: PloS One
https://www.readbyqxmd.com/read/28113186/epidural-spinal-stimulation-to-improve-bladder-bowel-and-sexual-function-in-individuals-with-spinal-cord-injuries-a-framework-for-clinical-research
#12
Roderic I Pettigrew, William J Heetderks, Christine A Kelley, Grace C Y Peng, Steven H Krosnick, Lyn B Jakeman, Katharine D Egan, Michael Marge
While some recent studies that apply epidural spinal cord stimulation (SCS) have demonstrated a breakthrough in improvement of the health and quality of the life of persons with spinal cord injury (SCI), the numbers of people who have received SCS are small. This is in sharp contrast to the thousands of persons worldwide living with SCI who have no practical recourse or hope of recovery of lost functions. Thus, the vision is to understand the full potential of this new intervention and to determine if it is safe and effective in a larger cohort, and if it is scalable so that it can be made available to all those who might benefit...
February 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28112099/performance-of-an-insect-inspired-target-tracker-in-natural-conditions
#13
Zahra M Bagheri, Steven D Wiederman, Benjamin S Cazzolato, Steven Grainger, David C O'Carroll
Robust and efficient target-tracking algorithms embedded on moving platforms, are a requirement for many computer vision and robotic applications. However, deployment of a real-time system is challenging, even with the computational power of modern hardware. As inspiration, we look to biological lightweight solutions-lightweight and low-powered flying insects. For example, dragonflies pursue prey and mates within cluttered, natural environments, deftly selecting their target amidst swarms. In our laboratory, we study the physiology and morphology of dragonfly 'small target motion detector' neurons likely to underlie this pursuit behaviour...
February 16, 2017: Bioinspiration & Biomimetics
https://www.readbyqxmd.com/read/28093977/the-amyloid-cascade-hypothesis-in-alzheimer-s-disease-it-s-time-to-change-our-mind
#14
Roberta Ricciarelli, Ernesto Fedele
Since its discovery in 1984, the beta amyloid peptide has treaded the boards of neurosciences as the star molecule in Alzheimer's disease pathogenesis. In the last decade, however, this vision has been challenged by evidence-based medicine showing the almost complete failure of clinical trials that experimented anti-amyloid therapies with great hopes. Moreover, data have accumulated which clearly indicates that this small peptide plays a key role in the physiological processes of memory formation. In the present review, we will discuss the different aspects of the amyloid cascade hypothesis, highlighting its pros and cons, and we will analyse the results of the therapeutic approaches attempted to date that should change the direction of Alzheimer's disease research in the future...
January 16, 2017: Current Neuropharmacology
https://www.readbyqxmd.com/read/28087932/the-complexity-of-fungal-vision
#15
Reinhard Fischer, Jesus Aguirre, Alfredo Herrera-Estrella, Luis M Corrochano
Life, as we know it, would not be possible without light. Light is not only a primary source of energy, but also an important source of information for many organisms. To sense light, only a few photoreceptor systems have developed during evolution. They are all based on an organic molecule with conjugated double bonds that allows energy transfer from visible (or UV) light to its cognate protein to translate the primary physical photoresponse to cell-biological actions. The three main classes of receptors are flavin-based blue-light, retinal-based green-light (such as rhodopsin), and linear tetrapyrrole-based red-light sensors...
December 2016: Microbiology Spectrum
https://www.readbyqxmd.com/read/28087407/polymeric-micelles-for-ocular-drug-delivery-from-structural-frameworks-to-recent-preclinical-studies
#16
REVIEW
Abhirup Mandal, Rohit Bisht, Ilva D Rupenthal, Ashim K Mitra
Effective intraocular drug delivery poses a major challenge due to the presence of various elimination mechanisms and physiological barriers that result in low ocular bioavailability after topical application. Over the past decades, polymeric micelles have emerged as one of the most promising drug delivery platforms for the management of ocular diseases affecting the anterior (dry eye syndrome) and posterior (age-related macular degeneration, diabetic retinopathy and glaucoma) segments of the eye. Promising preclinical efficacy results from both in-vitro and in-vivo animal studies have led to their steady progression through clinical trials...
January 11, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/28080961/interoception-beyond-homeostasis-affect-cognition-and-mental-health
#17
Manos Tsakiris, Hugo Critchley
Interoception refers to the sensing of the internal state of one's body. Interoception is distinct from the processing of sensory information concerning external (non-self) stimuli (e.g. vision, hearing, touch and smell) and is the afferent axis to internal (autonomic and hormonal) physiological control. However, the impact of interoception extends beyond homeostatic/allostatic reflexes: it is proposed to be fundamental to motivation, emotion (affective feelings and behaviours), social cognition and self-awareness...
November 19, 2016: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28073248/interplay-of-g-protein-coupled-receptors-with-the-membrane-insights-from-supra-atomic-coarse-grain-molecular-dynamics-simulations
#18
Xavier Periole
G protein-coupled receptors (GPCRs) are central to many fundamental cellular signaling pathways. They transduce signals from the outside to the inside of cells in physiological processes ranging from vision to immune response. It is extremely challenging to look at them individually using conventional experimental techniques. Recently, a pseudo atomistic molecular model has emerged as a valuable tool to access information on GPCRs, more specifically on their interactions with their environment in their native cell membrane and the consequences on their supramolecular organization...
January 11, 2017: Chemical Reviews
https://www.readbyqxmd.com/read/28063853/reaction-time-and-postural-sway-modify-the-effect-of-executive-function-on-risk-of-falls-in-older-people-with-mild-to-moderate-cognitive-impairment
#19
Morag E Taylor, Stephen R Lord, Kim Delbaere, Susan E Kurrle, A Stefanie Mikolaizak, Jacqueline C T Close
OBJECTIVES: To explore the relationship between cognitive performance and falls in older people with mild to moderate cognitive impairment (CI) by investigating the mediational effects of medical, medication, neuropsychological, and physiological factors. DESIGN: Secondary analysis, prospective cohort study. SETTING: Community and low-level care. PARTICIPANTS: 177 older people (aged 82 ± 7 years) with mild to moderate CI (MMSE 11-23; ACE-R < 83)...
October 25, 2016: American Journal of Geriatric Psychiatry
https://www.readbyqxmd.com/read/28050920/elderly-fall-risk-prediction-based-on-a-physiological-profile-approach-using-artificial-neural-networks
#20
Jafar Razmara, Mohammad Hassan Zaboli
Falls play a critical role in older people's life as it is an important source of morbidity and mortality in elders. In this article, elders fall risk is predicted based on a physiological profile approach using a multilayer neural network with back-propagation learning algorithm. The personal physiological profile of 200 elders was collected through a questionnaire and used as the experimental data for learning and testing the neural network. The profile contains a series of simple factors putting elders at risk for falls such as vision abilities, muscle forces, and some other daily activities and grouped into two sets: psychological factors and public factors...
November 1, 2016: Health Informatics Journal
keyword
keyword
119185
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"