Investigating the potential of Zernike polynomials to characterise spatial distribution of macular pigment

It has been postulated that particular patterns of macular pigment (MP) distribution may be associated with the risk for eye diseases such as age-related macular degeneration (AMD). This work investigates the potential of Zernike polynomials (ZP) to characterise the level and distribution of MP, and their suitability as a representation for analysis of the effects of age and AMD on MP patterns. As the case study, MP distribution maps computed using an experimental method based on fundus reflectance (MRIA) were obtained for ninety volunteers representing three groups: under-fifty without AMD, fifty and over without AMD, and fifty and over with AMD. ZP with 105 coefficients were fitted to the maps using least-squares optimisation and found to represent MP maps accurately (RMSE<10-1). One-way MANOVA analysis carried out on ZP representations showed that the three subject groups have significantly different means (Wilk's Lambda 0.125, p<0.0001). Linear discriminant analysis with leave-one-out scheme resulted in accuracy, sensitivity and specificity of classification according to, respectively, disease status regardless of age (81% all); disease status in the age-matched groups (87%, 88%, 86%); age irrespective of disease status (81%, 83%, 73%); and age for subjects without AMD (83%, 88%, 80%). Mean MP distributions computed from ZP coefficients for the three groups showed more elevated and more peaked MP for the healthy under-fifty group; more irregular and more elevated peripheral levels in over-fifty AMD group than in over-fifty non-AMD group; and moderate radial asymmetry in non-AMD over-50 group. The results suggest that ZP coefficients are capable of accurately representing MP in a way that captures certain spatial patterns of its distribution. Using the ZP representation MP maps could be classified according to both age and disease status with accuracy significantly greater than chance, with peak elevation, pattern irregularity and radial asymmetry identified as important features

A genetic algorithm optimization framework for the characterization of hyper-viscoelastic materials:application to human articular cartilage

This study aims to develop an automated framework for the characterization of materials which are both hyper-elastic and viscoelastic. This has been evaluated using human articular cartilage (AC). AC (26 tissue samples from 5 femoral heads) underwent dynamic mechanical analysis with a frequency sweep from 1 to 90 Hz. The conversion from a frequency- to time-domain hyper-viscoelastic material model was approximated using a modular framework design where finite element analysis was automated, and a genetic algorithm and interior point technique were employed to solve and optimize the material approximations. Three orders of approximation for the Prony series were evaluated at N = 1, 3 and 5 for 20 and 50 iterations of a genetic cycle. This was repeated for 30 simulations of six combinations of the above all with randomly generated initialization points. There was a difference between N = 1 and N = 3/5 of approximately ~5% in terms of the error estimated. During unloading the opposite was seen with a 10% error difference between N = 5 and 1. A reduction of ~1% parameter error was found when the number of generations increased from 20 to 50. In conclusion, the framework has proved effective in characterizing human AC

Evaluación de la continuidad y costo de dos estrategias de calidad ambiental interior en el edificio el cubo de Colsubsidio certificado con categoría gold por el sistema LEED del USGBC versión 2.2

Trabajo de investigaciónEl aumento de la contaminación en el planeta y el uso poco responsable de los recursos naturales, genero un interés global el cual viene desde hace varios años atrás, esto ocasiono que todos los temas medio ambientales y de sostenibilidad tuvieran un auge como respuesta a la problemática ambiental existente, esta problemática creo un interés en todos los ámbitos profesionales y al ser la construcción una de las industrias que más genera residuos y explotación de recursos naturales para su ejecución, era necesario dar una respuesta desde este campo, es por eso que surge LEADERSHIP IN ENERGY AND ENVIRONMENTAL DESING en adelante lo LEED, con una serie de normativas para generar un menor impacto medioambiental. La ejecución de edificios con certificación LEED ha ido en aumento en todo el mundo y como era de esperarse esta situación no fue ajena a Colombia. Es por eso que es tan importante abordar el análisis de los edificios que han sido certificados por el LEED en sus diferentes categorías, en esta oportunidad el caso de estudio es el edificio El Cubo de Colsubsidio, el cual fue certificado como LEED Gold en la versión 2.2 en el año 2013. En detalle, este proyecto se centrará en dos estrategias que componen el capítulo de estrategias de calidad interior del cual su sigla en inglés es IEQ INDOOR ENVIRONMENTAL QUALITY, una vez analizadas dichas estrategias de manera puntual para el edifico el Cubo de Colsubsidio, se podrá establecer si las estrategias han permanecido en el tiempo por medio de la gestión administrativa, generando ahorros, lo anterior con el fin que los interesados en el proceso puedan conocer el estado actual de las estrategias planteadas en el diseño del proyecto y ver que oportunidades de mejora tienen dichas estrategias.INTRODUCCIÓN 1. GENERALIDADES 2. MARCO DE REFERENCIA 3. METODOLOGÍA 4. PRODUCTOS A ENTREGAR 5. ENTREGA DE RESULTADOS ESPERADOS E IMPACTOS 6. NUEVAS AREAS DE ESTUDIO 7. CONCLUSIONES 8. RECOMENDACIONES 9. BIBLIOGRAFÍAEspecializaciónEspecialista en Gerencia de Obras Civile

FAIR v1.3: A simple emissions-based impulse response and carbon cycle model

Simple climate models can be valuable if they are able to replicate aspects of complex fully coupled earth system models. Larger ensembles can be produced, enabling a probabilistic view of future climate change. A simple emissions-based climate model, FAIR, is presented, which calculates atmospheric concentrations of greenhouse gases and effective radiative forcing (ERF) from greenhouse gases, aerosols, ozone and other agents. Model runs are constrained to observed temperature change from 1880 to 2016 and produce a range of future projections under the Representative Concentration Pathway (RCP) scenarios. The constrained estimates of equilibrium climate sensitivity (ECS), transient climate response (TCR) and transient climate response to cumulative CO₂ emissions (TCRE) are 2.86 (2.01 to 4.22) K, 1.53 (1.05 to 2.41) K and 1.40 (0.96 to 2.23) K (1000 GtC)¯¹ (median and 5–95 % credible intervals). These are in good agreement with the likely Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) range, noting that AR5 estimates were derived from a combination of climate models, observations and expert judgement. The ranges of future projections of temperature and ranges of estimates of ECS, TCR and TCRE are somewhat sensitive to the prior distributions of ECS∕TCR parameters but less sensitive to the ERF from a doubling of CO₂ or the observational temperature dataset used to constrain the ensemble. Taking these sensitivities into account, there is no evidence to suggest that the median and credible range of observationally constrained TCR or ECS differ from climate model-derived estimates. The range of temperature projections under RCP8.5 for 2081–2100 in the constrained FAIR model ensemble is lower than the emissions-based estimate reported in AR5 by half a degree, owing to differences in forcing assumptions and ECS∕TCR distributions

Green Buildings and Health

Green building design is becoming broadly adopted, with one green building standard reporting over 3.5 billion square feet certified to date. By definition, green buildings focus on minimizing impacts to the environment through reductions in energy usage, water usage, and minimizing environmental disturbances from the building site. Also by definition, but perhaps less widely recognized, green buildings aim to improve human health through design of healthy indoor environments. The benefits related to reduced energy and water consumption are well-documented, but the potential human health benefits of green buildings are only recently being investigated. The objective of our review was to examine the state of evidence on green building design as it specifically relates to indoor environmental quality and human health. Overall, the initial scientific evidence indicates better indoor environmental quality in green buildings versus non-green buildings, with direct benefits to human health for occupants of those buildings. A limitation of much of the research to date is the reliance on indirect, lagging and subjective measures of health. To address this, we propose a framework for identifying direct, objective and leading “Health Performance Indicators” for use in future studies of buildings and health

Adjustments in the forcing-feedback framework for understanding climate change

The traditional forcing-feedback framework has provided an indispensable basis for discussing global climate changes. However, as analysis of model behavior has become more detailed, shortcomings and ambiguities in the framework have become more evident and physical effects unaccounted for by the traditional framework have become interesting. In particular, the new concept of adjustments, which are responses to forcings that are not mediated by the global mean temperature, has emerged. This concept, related to the older ones of climate efficacy and stratospheric adjustment, is a more physical way of capturing unique responses to specific forcings. We present a pedagogical review of the adjustment concept, why it is important, and how it can be used. The concept is particularly useful for aerosols, where it helps to organize what has become a complex array of forcing mechanisms. It also helps clarify issues around cloud and hydrological response, transient vs. equilibrium climate change, and geoengineering

Association of Dietary Factors with Presence and Severity of Tinnitus in a Middle-Aged UK Population

Objective The impact of dietary factors on tinnitus has received limited research attention, despite being a considerable concern among people with tinnitus and clinicians. The objective was to examine the link between dietary factors and presence and severity of tinnitus. Design This study used the UK Biobank resource, a large cross-sectional study of adults aged 40–69. 171,722 eligible participants were asked questions specific to tinnitus (defined as noises such as ringing or buzzing in the head or ears). Dietary factors included portions of fruit and vegetables per day, weekly fish consumption (oily and non-oily), bread type, cups of caffeinated coffee per day, and avoidance of dairy, eggs, wheat and sugar. We controlled for lifestyle, noise exposure, hearing, personality and comorbidity factors. Results Persistent tinnitus, defined as present at least a lot of the time, was elevated with increased: (i) fruit/vegetable intake (OR = 1.01 per portion/day), (ii) bread (wholemeal/wholegrain, OR = 1.07; other bread, 1.20) and (iii) dairy avoidance (OR = 1.27). Persistent tinnitus was reduced with: (i) fish consumption (non-oily, OR = 0.91; oily, 0.95), (ii) egg avoidance (OR = 0.87) and (iii) caffeinated coffee consumption (OR = 0.99 per cup/day). Reports of “bothersome” tinnitus (moderate-severe handicap) increased with wholemeal/wholegrain bread intake (OR = 0.86). Reports of less frequent transient tinnitus increased with dairy avoidance (OR = 1.18) and decreased with caffeinated coffee (OR = 0.98 per cup/day) and brown bread (OR = 0.94). Conclusions This is the first population study to report the association between dietary factors and tinnitus. Although individually dietary associations are mostly modest, particular changes in diet, such as switching between foodstuffs, may result in stronger associations. These findings offer insights into possible dietary associations with tinnitus, and this may be useful when discussing management options in combination with other lifestyle changes and therapies

Understanding the rapid precipitation response to CO2 and aerosol forcing on a regional scale

Precipitation exhibits a significant rapid adjustment in response to forcing, which is important for understanding long-term climate change. In this study, fixed sea surface temperature (SST) simulations are used to analyze the spatial pattern of the rapid precipitation response. Three different forcing scenarios are investigated using data obtained from phase 5 of CMIP (CMIP5): an abrupt quadrupling of CO2, an abrupt increase in sulfate, and an abrupt increase in all anthropogenic aerosol levels from preindustrial to present day. Analysis of the local energy budget is used to understand the mechanisms that drive the observed changes. It is found that the spatial pattern of the rapid precipitation response to forcing is primarily driven by rapid land surface temperature change, rather than the change in tropospheric diabatic cooling. As a result, the pattern of response due to increased CO2 opposes that due to sulfate and all anthropogenic aerosols, because of the opposing surface forcing. The rapid regional precipitation response to increased CO2 is robust among models, implying that the uncertainty in long-term changes is mainly associated with the response to SST-mediated feedbacks. Increased CO2 causes rapid warming of the land surface, which destabilizes the troposphere, enhancing convection and precipitation over land in the tropics. Precipitation is reduced over most tropical oceans because of a weakening of overturning circulation and a general shift of convection to over land. Over most land regions in the midlatitudes, circulation changes are small. Reduced tropospheric cooling therefore leads to drying over many midlatitude land regions