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AB019. A proposed test of stereovision to identify local retinal abnormalities

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Annals of Eye science 2019年第1期 194-194页

作者： Tenia Wang alex s.baldwin Robert F.Hess Faculty of science McGill UniversityMontrealQCCanada Department of Ophthalmology Montreal General HospitalMcGill UniversityMontrealQCCanada

Background:The human visual system extracts depth information from disparity in the images seen by the two *** ability to calculate depth from disparity will be disrupted if local retinal abnormalities distort parts of those images,especially if these distortions are different in the two *** its early stages,age-related macular degeneration(AMD)causes slight distortions in the central vision field which differ in the two *** is the most common form of irreversible blindness in people over the age of *** goal of this project is to develop a stereoscopic perception test which leverages the sensitivity of binocular depth perception to detect the interocular differences symptomatic of either early-stage AMD or other diseases affecting the ***:A program was written in MATLAB that allowed separate left and right eye stimuli to be shown to the two *** 3D Vision 2 stereoscopic glasses were used to present the *** test we have developed consists of random dot patterns covering the central 5 degrees of *** or more disk-shaped perturbations in depth are displayed at different locations in the visual field of the *** the ten possible target locations,we present between one and four disks on each *** disks will only be visible if there is an undistorted input for that visual field location from the two *** participant uses a keypad to report the number of floating disks seen.A set of trials with randomized locations and numbers of disks is used to gather initial data on likely areas of stereoscopic vision deficit;afterwards,likelihoods for deficits in each location are calculated and used to generate customized subsequent ***:The software to perform the local stereovision test has been developed and is now being *** are currently collecting data from healthy normal subjects prior to applying the test to clinical *** order to simulate the central vision distortions of AMD,patches

关键词： Age-related macular degeneration(AMD) stereovision binocular disparity stereoscopic perception

AB012. The effects of monocular deprivation do not accumulate across days in adults with normal vision

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Annals of Eye science 2019年第1期 187-187页

作者： seung Hyun Min alex s.baldwin Robert F.Hess McGill Vision Research Department of Ophthalmology and Visual SciencesMcGill UniversityMontrealQCCanada

Background:We investigate whether changes in visual plasticity induced by monocular deprivation can be maintained across multiple *** has been known that monocular deprivation strengthens the deprived eye in adults with normal vision for a short period of time(30-60 minutes).This has been shown through a variety of visual tasks such as binocular combination and ***:Ten subjects were recruited and patched for five consecutive days for two *** used a binocular phase combination task to measure the subjects’sensory eye *** initially measured their baseline of sensory eye balance,patched their dominant eye,and then conducted post-patching measurements at 0,3,6,12,24 and 48 minutes after ***:We performed a 2-way ANOVA(Before *** patching×Day);we found that although the effect of monocular deprivation on the deprived eye was significant,F(1,9)=17.32,P=0.002,the effect of Day was ***:Hence we found no accumulation of the patching effect across five days in healthy *** suggests that the degree of remnant neural plasticity in adult primary visual cortex may be too limited to be exploited therapeutically.

关键词： Monocular deprivation neural plasticity binocular vision

*** role of equivalent internal noise and processing efficiency in individual differences in stereoacuity

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Annals of Eye science 2019年第1期 177-177页

作者： sara Alarcon Carrillo alex s.baldwin Robert F.Hess Department of Ophthalmology McGill Vision ResearchMcGill UniversityMontrealQCCanada

Background:The human visual system can use binocular disparity to make depth *** studies looking at the normal population have found a wide range in ability to perform depth-polarity *** explored if these large individual differences are also present when using a depth increment paradigm,and if they depend on the sign of ***:stereoacuity for detecting a wedge-shaped surface in a field of dots was measured in 53 adults(28 males)with normal *** better understand the variance in stereoacuity in the sample,for 18 subjects we measured stereo cuity with disparity noise added to the *** was unaffected at low levels of stimulus noise but beyond a critical value,it increased with the standard deviation of the *** this point the stimulus noise is equivalent to the internal noise of the *** measured at high stimulus noise levels reflects the efficiency with which a noisy input is processed by the visual *** derived both parameters by fitting the linear amplifier ***:stereoacuity ranged from 24 to 275 arc *** found population differences in stereoacuity were explained by variation in both processing efficiency and internal noise *** was a tendency for higher task performance for crossed disparities compared to uncrossed *** subject sensitivity differences between crossed and uncrossed disparity were due to a higher efficiency when processing one *** was a trend for subjects with equal acuity for the two directions to have an increase in processing efficiency compensating for higher internal noise levels for that ***:Overall,our results show that the individual differences in stereoacuity for depth increment tasks can be attributed to variances in both the quality of the received input and the efficiency of processing of disparity-processing mechanisms.

关键词： Vision psychophysics depth percept

*** enhancement reduces the temporary shift in perceptual eye dominance induced by a few hours of monocular occlusion

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Annals of Eye science 2019年第1期 191-191页

作者： Yasha sheynin Mira Chamoun alex s.baldwin Robert F.Hess Elvire Vaucher McGill Vision Research MontrealQCCanada Douglas Mental Health Institute MontréalQCCanada Universitéde Montréal MontréalQCCanada

Background:A few hours of monocular deprivation with a diffuser eye patch temporarily strengthens the contribution of the deprived eye to binocular *** shift in favour of the deprived eye is characterized as a form of adult visual *** in animal and human models suggest that neuromodulators can enhance adult brain plasticity in ***,acetylcholine has been shown to improve certain aspects of visual function and plasticity in *** investigated whether a single administration of donepezil(a cholinesterase inhibitor)could further augment the temporary shift in perceptual eye dominance that occurs after two hours of monocular ***:We conducted three experiments to investigate whether donepezil enhances the shift in perceptual eye dominance induced by monocular *** each experiment,healthy adults completed two experimental sessions while taking either donepezil(5 mg,oral)or a placebo(lactose)*** experiment 1 we patched the non-dominant eye for 2 hours and measured ocular balance with a binocular phase combination *** experiment 2 we patched for one hour to investigate whether donepezil shortens the amount of time necessary to observe a shift in ocular *** experiment 3 we patched for 2 hours and measured ocular balance with a binocular rivalry task to see if the effect of donepezil was comparable across the two *** calculated AUCs for the shift in perceptual eye dominance across five time points after removing the patch to compare our treatment conditions in each ***:Donepezil significantly reduces the magnitude and duration of the shift in perceptual eye dominance produced by both 2(Ps(Psuring ocular balance with a binocular phase combination *** also reduces the magnitude of the shift in ocular dominance when measuring balance with a binocular rivalry ***:Previous studies have demonstrated that c

关键词： Neural plasticity,donepezil(Aricept) short-term monocular deprivation ocular dominance(OD) binocular combination binocular rivalry neuromodulation excitatory/inhibitory balance(E/I balance)

A decomposition of light’s spin angular momentum density

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Light(science & Applications) 2024年第8期13卷 1578-1589页

作者： alex J.Vernon sebastian Golat Claire Rigouzzo Eugene A.Lim Francisco J.Rodríguez-Fortuño Department of Physics King’s College LondonStrandLondon WC2R 2LSUK London Centre for Nanotechnology LondonUK

Light carries intrinsic spin angular momentum(sAM)when the electric or magnetic field vector rotates over time.A familiar vector equation calculates the direction of light’s sAM density using the right-hand rule with reference to the electric and magnetic polarisation *** Maxwell’s equations,this vector equation can be decomposed into a sum of two distinct terms,akin to the well-known Poynting vector decomposition into orbital and spin *** present the first general study of this spin decomposition,showing that the two terms,which we call canonical and Poynting spin,are chiral analogies to the canonical and spin momenta of light in its interaction with *** canonical momentum,canonical spin is directly *** canonical and Poynting spin incorporate spatial variation of the electric and magnetic fields and are influenced by optical *** decomposition allows us to show that a linearly polarised vortex beam,which has no total sAM,can nevertheless exert longitudinal chiral pressure due to equal and opposite canonical and Poynting spins.

关键词： canonical momentum angular

Blast waveform tailoring using controlled venting in blast simulators and shock tubes

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Defence Technology（防务技术） 2024年第7期37卷 14-26页

作者： Edward Chern Jinn Gan alex Remennikov David Ritzel Faculty of Engineering and Information sciences University of WollongongWollongongNSW2522Australia Dyn-FX Consulting Ltd 19 Laird Ave NorthAmherstburgONN9V 2T5Canada

A critical challenge of any blast simulation facility is in producing the widest possible pressure-impulse range for matching against equivalent high-explosive *** tubes and blast simulators are often constrained with the lack of effective ways to control blast wave profiles and as a result have a limited performance *** wave shaping techniques employed in some facilities are reviewed but often necessitate extensive geometric modifications,inadvertently cause flow anomalies,and/or are only applicable under very specific *** paper investigates controlled venting as an expedient way for waveforms to be tuned without requiring extensive modifications to the driver or existing geometry and could be widely applied by existing and future blast simulation and shock tube *** use of controlled venting is demonstrated experimentally using the Advanced Blast simulator(shock tube)at the Australian National Facility of Physical Blast simulation and via numerical flow simulations with Computational Fluid *** venting is determined as an effective method for mitigating the impact of re-reflected waves within the blast *** control method also allows for the adjustment of parameters such as tuning the peak overpressure,the positive phase duration,and modifying the magnitude of the negative phase and the secondary shock of the blast *** paper is concluded with an illustration of the potential expanded performance range of the Australian blast simulation facility when controlled venting for blast waveform tailoring as presented in this paper is applied.

关键词： Advanced blast simulator shock wave propagation Far-field explosion Blast loads Blast waves Computational fluid dynamics

Kinematics ofmandibular advancement devices(MADs):Why do some MADs move the lower jaw backward duringmouth opening?

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Bio-Design and Manufacturing 2024年第5期7卷 637-650页

作者： Juan A.Cabrera alex Bataller sergio Postigo Marcos García Mechanical Engineering Department University of Malaga29071 MalagaSpain

Mandibular advancement devices(MADs)are widely used treatments for obstructive sleep *** function by advancing the lower jaw to open the upper *** increase patient comfort,most patients allow the mouth to be ***,not all systems maintain the lower jaw in a forward position during mouth opening,which results in the production of a retrusion that favors the collapse of the upper ***,the kinematic behavior of the mechanism formed by the mandible-device assembly depends on jaw *** means that,during mouth opening,some devices cause lower jaw protrusion in some patients,but cause its retraction in *** this study,we report the behavior of well-known devices currently on *** do so,we developed a kinematic model of the lower jawdevice *** validated for all devices analyzed using a high-resolution camera *** results show that some of the devices analyzed here did not produce the correct behavior during patient mouth opening.

关键词： Mandibular advancement devices Lower jaw kinematics sleep apnea

Clean,but not green:Emission assessment,forecast modelling and policy solutions for plastic microbeads from personal care products in India

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Emerging Contaminants 2024年第3期10卷 124-133页

作者： Riya Kumbukattu alex Thomas Maes suja Purushothaman Devipriya school of Environmental studies Cochin University of Science and Technology682022India GRID-Arendal Teaterplassen 34836ArendalNorway

Intentionally added plastic microbeads in personal care products(PCP)are an underestimated source of *** microbeads are added as fillers,to increase product volume or aesthetics and allegedly have the purpose of cleansing and *** assess and forecast microbead emissions in India,this study analysed 45 items from four different categories of personal care products:face wash,face scrub,shower gel and body scrub available in the Indian market and determined microbead abundance,size,colour,shape and polymer ***,an emission estimation and time-seriesbased forecast for 2030 was done using ARIMA(0,2,0)for individual categories and *** results indicate that 45.00%of the products contained irregular or smooth microplastics,with Polyethylene being the dominant polymer,followed by Polypropylene,Polystyrene,Polyurethane and Polycaprolactone.A significant number of products(23.33%)contained cellulose microbeads,with ambiguity regarding their *** identified microbeads were mainly irregular in shape and granular in texture,especially ***/transparent colour dominated the identified microbeads,followed by blue,pink,yellow,red and *** 1.34%of the total product contained plastic microbeads,with 5.04%and 0.04%being the highest and lowest percentages *** average size of microbeads was found to be 640.74 mm,452.45 mm,556.66 mm and 606.30 mm in different *** overall annual emission estimation was 3.51×10^(19)(highest),2.14×10^(18)(lowest)and 1.37×10^(19)(average)in 2021 and forecasted to be 4.12×10^(19)(highest),2.52×10^(18)(lowest)and 1.611019(average)in *** exorbitantly high value is due to India's significant population,globalisation,inefficient wastewater efficiency,growing economy and disposable income.A lack of policies and adequate regulations further add to *** study emphasises and recommends the development of stringent policies and other well-tailored mitig

关键词： Microplastic beads Time-series forecast Policy solutions Emission estimation Personal care products

A systematic review of climate change impacts,adaptation strategies,and policy development in West Africa

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Regional sustainability 2024年第2期5卷 13-25页

作者： Camillus Abawiera WONGNAA alex Amoah sEYRAM suresh BABU Department of Agricultural Economics Agribusiness and ExtensionKwame Nkrumah University of Science and TechnologyKumasi00233Ghana International Food Policy Research Institute Washington20005USA

Climate change studies are diverse with no single study giving a comprehensive review of climate change impacts,adaptation strategies,and policy development in West *** unavailability of an all-inclusive study to serve as a guide for practitioners affects the effectiveness of climate change adaptation strategies proposed and adopted in the West African *** purpose of this study was to review the impacts of climate change risks on the crop,fishery,and livestock sectors,as well as the climate change adaptation strategies and climate-related policies aimed at helping to build resilient agricultural production systems in West *** review process followed a series of rigorous stages until the final selection of 56 articles published from 2009 to ***,the results highlighted the adverse effects of climate change risks on food *** found a continuous decline in food crop ***,the livestock sector experienced morbidity and mortality,as well as reduction in meat and milk *** fishery sector recorded loss of fingerlings,reduction in fish stocks,and destruction of mariculture and *** West Africa,climate-smart agriculture technologies,physical protection of fishing,and inclusion of gender perspectives in programs appear to be the major adaptation *** study therefore recommends the inclusion of ecosystem and biodiversity restoration,weather insurance,replacement of unsafe vessels,and strengthening gender equality in all climate change mitigation programs,as these will help to secure enough food for present and future generations.

关键词： Climate change Climate extreme events Food security Adaptation strategies Climate-smart agriculture West Africa