Effects Of Light On Humans

Purpose: To identify the effect of additional elastic force on the kinetic and kinematic characteristics, as well as the magnitude of leg stiffness, during the performance of accentuated countermovement jumps (CMJs). Methods: Fifteen trained male subjects performed 3 types of CMJ including free CMJ (FCMJ; ie, body weight), ACMJ-20, and ACMJ-30 (ie, accentuated eccentric CMJ with downward tensile force equivalent to 20% and 30% body mass, respectively). A force platform synchronized with 6 high-speed infrared cameras was used to measure vertical ground-reaction force (VGRF) and displacement. Results: Using downward tensile force during the lowering phase of a CMJ and releasing the bands at the start of the concentric phase increased maximal concentric VGRF (6.34%), power output (23.21%), net impulse (16.65%), and jump height (9.52%) in ACMJ-30 compared with FCMJ (all P < .05). However, no significant difference was observed in the magnitude of leg stiffness between the 3 modes of jump. The results indicate that using downward recoil force of the elastic material during the eccentric phase of a CMJ could be an effective method to enhance jump performance by applying a greater eccentric loading on the parallel and series elastic components coupled with the release of stored elastic energy. Conclusions: The importance of this finding is related to the proposition that power output, net impulse, takeoff velocity, and jump height are the key parameters for successful athletic performance, and any training method that improves impulse and power production may improve sports performance, particularly in jumping aspects of sport. © 2013 Human Kinetics, Inc.

http://www.ncbi.nlm.nih.gov/pubmed/23428490 
http://europepmc.org/abstract/MED/23428490

Daylight was the main source of lighting in vernacular architecture, and building design accordingly responded to its strategic limitations. Needs for new types of buildings in conjunction with the great development of electric lamp led to the ascendancy of electric lighting. However, a return to the interest in natural lighting emerged with the energy crises in the 1970s. In order to meet the new requirements, new optical materials and technologies have been combined to produce innovative daylighting systems able to deliver daylight long distances into buildings. There is a need to maximize the utilization of daylight, to optimize the integration between daylighting and electric lighting systems so as to increase the potential application of daylighting system. The development of the hybrid lighting systems (HLS) aims to satisfy these desires. 
HLS seek to maximize the utilization of daylight by tracking sunrays, and in most cases they are concentrated to minimize the light guidance size, which eases the installation and in turn increases the potential application of HLS. Prior to delivery of daylight, electric lighting source is added to instantly top up any possible shortage of daylight. A control system works to regulate this process to minimize the energy consumption. The one output device for both sources used in the HLS made it possible to no longer need for two distinct lighting systems to be installed in one space.
Investigations in this work have measured HLS performance in terms of light delivery, light quality, energy saving and economic performance. Potential applications of HLS in different buildings types and across a wide geographical region have been investigated. An overall evaluation of HLS has been carried out. Furthermore, methods to estimate illuminance data, where measured data is unavailable, have been developed to help investigating systems performance over different geographical locations. Illuminance data produced using the developed methods showed superiority over that produced using other available methods, with the additional advantages of simplicity and universal application.
HLS performance and potential application are influenced by many variables including system characteristics, building types, and location features. The research showed that the most important variable is the concentration ratio of the light collector. This determines HLS ability to collect daylight, and thus its applicability in different geographical locations. It also stipulates light collector and guidance size, and thus HLS applicability in different building type, influences the delivered light quality, and thus occupants’ perception of daylight, and influences HLS initial and running costs. Delivered light by HLS may not be perceived as daylight due to the absence of the outside view, the likely change in daylight colour because of the mixing with electric light, the fade awareness of the seasonal and diurnal changes in daylight colour and intensity because of the instant and continuous top up. The challenges of cost, light quality and integration in building design are the most serious barriers confronting HLS ability to penetrate the market and to be used widely. This work makes suggestions to overcome these problems.

The symbol of light has commonly represented human desires for goodness, order, truth, perpetual abundance, and the transcendence of earthly limits. Modern practices of artificial light cultivation remain associated with a symbolic promise to banish darkness and its corollaries——lack, death, ignorance, disease, and chaos. In today’’s global and increasingly urbanized world this association is most notably emblematized in the modern city, which is lit up at night in a technologically brilliant display that ironically also conveys the deepening ecological disaster of anthropogenic climate change. Responding to German philosopher Hans Blumenberg’’s essay ‘‘Light as a Metaphor for Truth’’, this article seeks to uncover the ways that technological figurations of light transform an ancient association with freedom into dangerous practices of fuel fetish and overconsumption. Increased awareness of such habits of overconsumption could help to decrease urban light pollution and the ecological danger that it signifies.

Introduction Melatonin and light treatment are recommended for hastening adaptation to time zone change. We evaluated an afternoon regimen of 3 mg sustained release (SR) melatonin with and without next morning green light treatment for circadian phase advance. Effects of melatonin and light were tested separately and then combined to determine if the total phase change is additive or synergistic.
Material and methods For each condition (melatonin, placebo, light, melatonin plus light), 11 subjects spent from Tuesday evening until Friday afternoon in the laboratory. For all four conditions, the following sleep schedule was maintained: night 1, 2345 to 0630 hours, night 2, 1600 to 0530 hours, and night 3, 2345 to 0700 hours. For the light- only condition, light treatment was administered between 0700 and 0800 hours on Thursday. For melatonin-only or placebo conditions, capsules were administered at 1600 hours on Wednesday. For the combined condition, melato- nin was administered at 1600 hours on Wednesday with light treatment between 0600 and 0700 hours on Thursday. Circadian phase was assessed by calculating dim light melatonin onset (DLMO) from salivary melatonin, using a mean baseline +2 standard deviations (BL + 2 SD) thresh- old. For all four conditions, pre-treatment and post- treatment DLMO assessments were on Tuesday and Thursday evenings, respectively.
Results Phase advances were: melatonin at 1600 hours, 0.72 h p<0.005, light treatment from 0700 to 0800 hours, 0.31 h, non-significant, and the combined treatment, 1.04 h p < 0.0002.
Conclusion The phase advance from the combination of afternoon melatonin with next morning light is additive.

Conventionally, patellar tendon-bearing (PTB) sockets, which need high dexterity of prosthetist, are widely used. Lack of chartered and experienced prosthetist has often led to painful experience of wearing prosthesis and this will in turn deter the patients to wear the prosthesis, which will further aggravate stump shrinkage. Thus, the hydrostatic socket which demands relatively lower level of fabricating skill is proposed to replace the PTB socket in order to produce the equivalent, if not better, quality of support to the amputee patients. Both sockets' pressure profiles are studied and compared using finite element analysis (FEA) software. Three-dimensional models of both sockets were developed using MIMICS software. The analysis results showed that hydrostatic socket did exhibit more uniform pressure profiles than that of PTB socket. PTB socket showed pressure concentration near the proximal brim of the socket and also at the distal fibula. It was also found that the pressure magnitude in hydrostatic socket is relatively lower than that of PTB socket.

http://www.ncbi.nlm.nih.gov/pubmed/20405814
www.actabio.pwr.wroc.pl/Vol11No4/6.pdf

“A painter should begin every canvas with a wash of black, because all things in nature are dark except where exposed by the light.”
― Leonardo da Vinci
Without light, there would be no life on Earth. Electromagnetic radiation (EMR) across a very wide spectrum heats the planet sufficiently for biological activity; EMR across the range from ~380 to ~780 nm is responsible for most plant life and, most importantly to us, stimulates photoreceptive cells in the retina of most creatures with eyes. This is so important to humans that the very definition of light in the Système International d’Unités [the International System of Units] is based on our biological response to this part of the electromagnetic spectrum (Commission Internationale de l’Eclairage [CIE], 2011), the only physical quantity that is linked to a human capability. This photodetection reveals the world to us through vision and attunes us to the cyclical pattern of light and dark so that we – as virtually all life on earth (fauna and flora) – have periods of activity and periods of rest. It is hard to overestimate the role light has in all aspects of human function, and particularly those of interest to psychologists: perception, cognition, affect, communication, comfort, sleep.
Not only does light influence behaviour, but our choice to use lighting is a behaviour, one that has environmental consequences. By one estimate, lighting accounts for 19% of global electricity consumption (International Energy Agency, 2006). Furthermore, fuel-based lighting, used in parts of the world without a stable electrical supply not only contributes to carbon dioxide emissions but also creates local problems with air quality. Providing more efficient, higher-intensity, higher-quality light has benefits for health and quality of life. Outside psychology, much lighting research aims to support limits on lighting energy use while creating lighting conditions that do not adversely affect human needs.
Surprisingly, light and lighting have not received much attention from this journal: A quick search through the annals of the Journal of Environmental Psychology yielded only 6 papers with ‘light’ or ‘lighting’ as a keyword (in contrast, 281 used noise or sound). In the 34 years that our domain has had this journal, it has featured no more than 27 articles reporting on the experience or psychological effect of light or lighting, i.e., less than one article per year on average (see also Figure 1). Interestingly, there are over 4000 articles in the APA PsycInfo database with the keyword “illumination” over the same 34-year period, as well as thousands of papers in multidisciplinary, engineering, architecture, physiology, and physics journals. We are puzzled by the apparent inattention that environmental psychologists have given to this important topic, and have sought to inspire our colleagues to take up this topic by presenting this special issue.

Examiner's comments (abridged):

Professor Louise Westling, University of Oregon (author of The Green Breast of the New World, and Sacred Groves and Ravaged Gardens):
“Berry’s “Under the Dominion of Light: An Ecocritical Mythography” is a substantial contribution to ecocriticism and ... an ambitious attempt to place myth theory in rigorous dialogue with European cultural theory of the past century in order to analyse the deep sources of the present ecological dilemma in the mythos of transcendent light… it succeeds admirably in making its case.
The project is certain to be influential in international ecocritical debates, because it provides a strong new perspective on mythic tendencies driving Western economic behaviour.”

Laurence Coupe, Manchester Metropolitan University (author of Myth in the New Critical Idiom series, and The Green Studies Reader):
“This thesis is ambitious, erudite, well-informed and articulate. It clearly demonstrates the candidate’s ability to synthesise a great deal of diffuse material and to focus on an original theme.”

In this study, the kinetics of adsorption of Pb(II) from aqueous solution onto palm shell-based activated carbon (PSAC) were investigated by employing ion selective electrode (ISE) for real-time Pb(II) and pH monitoring. Usage of ISE was very appropriate for real-time adsorption kinetics data collection as it facilitated recording of adsorption data at very specific and short time intervals as well as provided consistent kinetics data. Parameters studied were initial Pb(II) concentration and agitation speed. It was found that increases in initial Pb(II) concentration and agitation speed resulted in higher initial rate of adsorption. Pseudo first-order, pseudo second-order, Elovich, intraparticle diffusion and liquid film diffusion models were used to fit the adsorption kinetics data. It was suggested that chemisorption was the rate-controlling step for adsorption of Pb(II) onto PSAC since the adsorption kinetics data fitted both the pseudo second-order and Elovich models well. © 2007 Elsevier Ltd. All rights reserved.

http://ac.els-cdn.com/S0960852407008486/1-s2.0-S0960852407008486-main.pdf?_tid=69c04c76-2364-11e4-94d2-00000aab0f6c&acdnat=1407987670_02ab68b4ce0b91cc8618321077a4cc39 
http://www.sciencedirect.com/science/article/pii/S0960852407008486

Dilated cardiomyopathy (DCM) is a common cardiac disease which leads to the deterioration in cardiac performance. A computational fluid dynamics (CFD) approach can be used to enhance our understanding of the disease, by providing us with a detailed map of the intraventricular flow and pressure distributions. In the present work, effect of ventricular size on the intraventricular flow dynamics and intraventricular pressure gradients (IVPGs) was studied using two different implementation methods, i.e. the geometry-prescribed and the fluid structure interaction (FSI) methods. Results showed that vortex strength and IVPGs are significantly reduced in a dilated heart, leading to an increased risk of thrombus formation and impaired ventricular filling. We suggest FSI method as the ultimate method in studying ventricular dysfunction as it provides additional cardiac disease prognostic factors and more realistic model implementation.

http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6347432

Dilated cardiomyopathy (DCM) is a common cardiac disease which leads to the deterioration in cardiac performance. A computational fluid dynamics (CFD) approach can be used to enhance our understanding of the disease, by providing us with a detailed map of the intraventricular flow and pressure distributions. In the present work, effect of ventricular size on the intraventricular flow dynamics and intraventricular pressure gradients (IVPGs) was studied using two different implementation methods, i.e. the geometry-prescribed and the fluid structure interaction (FSI) methods. Results showed that vortex strength and IVPGs are significantly reduced in a dilated heart, leading to an increased risk of thrombus formation and impaired ventricular filling. We suggest FSI method as the ultimate method in studying ventricular dysfunction as it provides additional cardiac disease prognostic factors and more realistic model implementation.

To identify the effect of additional elastic force on the kinetic and kinematic characteristics, as well as the magnitude of leg stiffness, during the performance of accentuated countermovement jumps (CMJs). Fifteen trained male subjects performed 3 types of CMJ including free CMJ (FCMJ; ie, body weight), ACMJ-20, and ACMJ-30 (ie, accentuated eccentric CMJ with downward tensile force equivalent to 20% and 30% body mass, respectively). A force platform synchronized with 6 high-speed infrared cameras was used to measure vertical ground-reaction force (VGRF) and displacement. Using downward tensile force during the lowering phase of a CMJ and releasing the bands at the start of the concentric phase increased maximal concentric VGRF (6.34%), power output (23.21%), net impulse (16.65%), and jump height (9.52%) in ACMJ-30 compared with FCMJ (all P &lt; .05). However, no significant difference was observed in the magnitude of leg stiffness between the 3 modes of jump. The results indicate ...

Background: Good suspension lessens the pistoning (vertical displacement) of the residual limb inside the prosthetic socket. Several methods are used for measuring the pistoning. Study Design: Clinical trial. Objectives: To introduce and evaluate a new simple method for measuring the pistoning between the soft liner and socket in transtibial prostheses. Methods: Five transtibial prostheses with Iceross silicone liner and shuttle lock were made for the subjects. The pistoning was measured between the liner and socket by a photographic method in single limb support on the prosthetic limb (full weight bearing), non-weight bearing and under three static axial loading conditions (30, 60 and 90 N). Results: This new method enabled us to measure the pistoning between the liner and prosthetic socket. The reproducibility of measurements in different trials of one session and between two sessions by two observers was shown to be high. The average of displacement between the liner and socket was about 9 mm in non-weight bearing compared with full weight bearing. Furthermore, as we expected, the average of pistoning increased consistently by adding the loads. Conclusions: This new method provides for easy and inexpensive determination of pistoning between the liner and socket by every prosthetist in clinical settings. © The International Society for Prosthetics and Orthotics 2011.

http://www.ncbi.nlm.nih.gov/pubmed/21975850
http://poi.sagepub.com/content/35/4/360.short

The spread of light witnessed in the NASA image of the planet at night reveals the brilliance of human technological innovation, the extent of global urban colonization, and the associated threat of ecological crisis. This article uses this image as a starting point for an interdisciplinary discussion about the development of lighting technologies and associated symbolic content, including both religious and secular ideals about light’s victory over darkness. A close analysis of the image puts comparative levels of technological development in the context of a widespread faith in the magic of electricity (which is clean, silent and immediate) to provide abundance. This dream transforms our ancient fascination with fire but also hides the ecological costs of the new form, which in many ways exacerbates dualistic relations between culture and nature. Finally the article discusses the costs of light pollution, urbanization, fossil fuel consumption and commodification.

Proposal for
City of LAS VEGAS
Nevada, USA

PROJECT OBJECTIVES

The objective is to valorize the City of Las Vegas  with an innovative 2 kilometers large Sign
seen from 20 miles employing equipment and materials suitable
for full environmental sustainability of the 21st Century

The μ rhythm is an electroencephalogram (EEG) signal located at the central region of the brain that is frequently used for studies concerning motor activity. Quite often, the EEG data are contaminated with artifacts and the application of blind source separation (BSS) alone is insufficient to extract the μ rhythm component. We present a new two-stage approach to extract the μrhythm component. The first stage uses second-order blind identification (SOBI) with stationary wavelet transform (SWT) to automatically remove the artifacts. In the second stage, SOBI is applied again to find the μ rhythm component. Our method is first compared with independent component analysis with discrete wavelet transform (ICA-DWT) as well as SOBI-DWT, ICA-SWT, and regression method for artifact removal using simulated EEG data. The results showed that the regression method is more effective in removing electrooculogram (EOG) artifacts, while SOBI-SWT is more effective in removing electromyogram (EMG) artifacts as compared to the other artifact removal methods. Then, all the methods are compared with the direct application of SOBI in extracting μ rhythm components on simulated and actual EEG data from ten subjects. The results showed that the proposed method of SOBI-SWT artifact removal enhances the extraction of the μrhythm component. © 2009 IEEE.

http://www.ncbi.nlm.nih.gov/pubmed/19457744 
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4956992&tag=1

For patient's receiving mechanical circulatory support, malfunction of the left ventricular assist device (LVADs) as well as mal-positioning of the cannula imposes serious threats to their life. It is therefore important to characterize the flow pattern and pressure distribution within the ventricle in the presence of an LVAD. In this paper, we present a 2D axisymmetric fluid structure interaction model of the passive left ventricle (LV) incorporating an LVAD cannula to simulate the effect of the LVAD cannula placement on the vortex dynamics. Results showed that larger recirculation area was formed at the cannula tip with increasing cannula insertion depth, and this is believed to reduce the risk of thrombus formation. Furthermore, we also simulated suction events (collapse of the LV) by closing the inlet. Vortex patterns were significantly altered under this condition, and the greatest LV wall displacement was observed at the part of the myocardium closest to the cannula tip.

http://www.ncbi.nlm.nih.gov/pubmed/23367368
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6347433&tag=1

Conventionally, patellar tendon-bearing (PTB) sockets, which need high dexterity of prosthetist, are widely used. Lack of chartered and experienced prosthetist has often led to painful experience of wearing prosthesis and this will in turn deter the patients to wear the prosthesis, which will further aggravate stump shrinkage. Thus, the hydrostatic socket which demands relatively lower level of fabricating skill is proposed to replace the PTB socket in order to produce the equivalent, if not better, quality of support to the amputee patients. Both sockets' pressure profiles are studied and compared using finite element analysis (FEA) software. Three-dimensional models of both sockets were developed using MIMICS software. The analysis results showed that hydrostatic socket did exhibit more uniform pressure profiles than that of PTB socket. PTB socket showed pressure concentration near the proximal brim of the socket and also at the distal fibula. It was also found that the pressure magnitude in hydrostatic socket is relatively lower than that of PTB socket.

OBJECTIVE: The objectives of this study were to compare the effects of a newly designed magnetic suspension system with that of two existing suspension methods on pistoning inside the prosthetic socket and to compare satisfaction and perceived problems among transtibial amputees. DESIGN: In this prospective study, three lower limb prostheses with three different suspension systems were fabricated for ten transtibial amputees. The participants used each of the three prostheses for 1 mo in random order. Pistoning inside the prosthetic socket was measured by motion analysis system. The Prosthesis Evaluation Questionnaire was used to evaluate satisfaction and perceived problems with each suspension system. RESULTS: The lowest pistoning motion was found with the suction system compared with the other two suspension systems (P < 0.05). The new suspension system showed peak pistoning values similar to that of the pin lock system (P = 0.086). The results of the questionnaire survey revealed significantly higher satisfaction rates with the new system than with the other two systems in donning and doffing, walking, uneven walking, stair negotiation, and overall satisfaction (P < 0.05). CONCLUSIONS: The new suspension system has the potential to be used as an alternative to the available suspension systems. The pistoning motion was comparable to that of the other two systems. The new system showed compatible prosthetic suspension with the other two systems (suction and pin lock). The satisfaction with donning and doffing was high with the magnetic system. Moreover, the subjects reported fewer problems with the new system. Copyright © 2012 by Lippincott Williams & Wilkins.

http://graphics.tx.ovid.com/ovftpdfs/FPDDNCLBPCEOKH00/fs047/ovft/live/gv024/00002060/00002060-201212000-00003.pdf 
http://www.ncbi.nlm.nih.gov/pubmed/23168378

We set an experimental session investigating the
influence of different light sources and background noise
on the perceived contrast, using self-luminous images of
a target on a monitor in a semi-anechoic room. Behind a
dark panel, on the two sides of the screen, two holes
(about 100 mm diameter) accommodate the LED source
and the reference source (incandescent). A dodecahedron
noise source is also positioned near the tester, generating
a stochastic noise we specifically designed for this
experiment.

In a paper which challenges social cliches and stereotypes, Tim Edensor and Steve Millington examine the often-denigrated phenomenon of residential Christmas lights - and argue for their positive role in the creation of local identities and community cohesion.