80 research outputs found

    Mapping of Brain Functions and Spatial Luminance Distributions as Innovative Tools for Assessing Discomfort Glare in the Built Environment

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    A series of "proof-of-concept" projects are set out aimed at bringing together built environment researchers attempting to understand what constitutes ‘comfortable' space and neuroscientists investigating the functional characteristics of the human brain. The long-term goal is to address the question of whether there are regions of the brain that are specifically engaged when people experience spaces they consider to be comfortable, pleasing or even beautiful. Glare is an area of research that has been recognised as a problem in both interior and exterior lighting. Recent advances in technology make it an ideal candidate for the proposed "proof-of-concept” study. The mapping of brain functions through functional magnetic resonance imaging, the mapping of luminance distributionsin a visual scene, and the study of distraction and its influence on discomfort glare can be combined to form the basis of an innovative tool box for new research

    Integrated Solutions for Daylighting and Electric Lighting: IEA SHC Task 61/EBC Annex 77, Subtask D – Proposal and First Results

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    The integration of daylight and electric lighting, considering user satisfaction and energy savings potentially can contribute significantly to reduce energy demand for lighting, that represents 18% of global energy demands. This paper presents the work and first results of IEA SHC Task 61/EBC Annex 77 “Integrated Solutions for Daylighting and Electric Lighting: From component to user centered system efficiency”, a joint project activity between the Solar Heating and Cooling (SHC) and Energy in Buildings and Communities (EBC). The project deals with the idea that an integrated design approach for the whole system, combining daylighting, electric lighting, the associated lighting controls and the users’ interaction, can achieve higher energy saving than the simple energy-efficient design of single components. First results show the main experience from three completed case studies

    Monitoring protocol to assess the overall performance of lighting and daylighting retrofit projects

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    In the field of lighting and daylighting, standard monitoring procedures to assess the overall performance of retrofit projects are scarce. Nevertheless the access to monitored data is crucial to assess whether daylighting or electric lighting systems deliver the expected performance in terms of cost-effectiveness and energy efficiency. In order to bridge this gap, a monitoring protocol is under development as part of the International Energy Agency – Solar Heating and Cooling Programme (IEA-SHC) Task 50 ‘Advanced Lighting Solutions for Retrofitting Buildings’. The protocol focuses on lighting and/or daylighting (façade or roof) retrofit in the non-residential building stock. It covers four key aspects: energy efficiency, costs, quality of the lighting environment and user satisfaction. The main features of this protocol are presented in this paper, along with some lessons learned from the ongoing application on selected case studies

    Performance Evaluation of Lighting and Daylighting Retrofits: Results from IEA SHC Task 50

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    AbstractThis article presents some results from a large monitoring campaign performed in 22 buildings around the world as part of International Energy Agency (IEA) Task 50 “Advanced lighting solutions for retrofitting buildings”. This article mainly addresses the work of Subtask D, which aims to demonstrate sound lighting retrofit solutions in a selection of representative, typical Case Studies. In order to evaluate the Case Studies, a monitoring protocol was developed to assess the overall lighting performance taking into consideration: 1) Energy use, 2) Retrofit costs, 3) Photometric assessment, and 4) User assessment. The monitoring was carried out from June 2014 to December 2015 in 22 non-residential buildings in ten countries. This article presents results from selected Case Studies, drawing conclusions regarding retrofit solutions as well as reflecting on methodological procedures for the measurements and data collection. Measured data as well as key conclusions from Subtask D will be summarized in an electronic web and portable sourcebook at the end of the IEA Task 50 (December 2015), which will be freely available through the Internet

    Simian varicella virus infection of Chinese rhesus macaques produces ganglionic infection in the absence of rash

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    Varicella-zoster virus (VZV) causes varicella (chickenpox), becomes latent in ganglia along the entire neuraxis, and may reactivate to cause herpes zoster (shingles). VZV may infect ganglia via retrograde axonal transport from infected skin or through hematogenous spread. Simian varicella virus (SVV) infection of rhesus macaques provides a useful model system to study the pathogenesis of human VZV infection. To dissect the virus and host immune factors during acute SVV infection, we analyzed four SVV-seronegative Chinese rhesus macaques infected intratracheally with cell-associated 5 × 103 plaque-forming units (pfu) of SVV-expressing green fluorescent protein (n = 2) or 5 × 104 pfu of wild-type SVV (n = 2). All monkeys developed viremia and SVV-specific adaptive B- and T-cell immune responses, but none developed skin rash. At necropsy 21 days postinfection, SVV DNA was found in ganglia along the entire neuraxis and in viscera, and SVV RNA was found in ganglia, but not in viscera. The amount of SVV inoculum was associated with the extent of viremia and the immune response to virus. Our findings demonstrate that acute SVV infection of Chinese rhesus macaques leads to ganglionic infection by the hematogenous route and the induction of a virus-specific adaptive memory response in the absence of skin rash

    Prevalence of intrathecal acyclovir resistant virus in herpes simplex encephalitis patients

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    Herpes simplex encephalitis (HSE) is a life-threatening complication of herpes simplex virus (HSV) infection. Acyclovir (ACV) is the antiviral treatment of choice, but may lead to emergence of ACV-resistant (ACVR) HSV due to mutations in the viral UL23 gene encoding for the ACV-targeted thymidine kinase (TK) protein. Here, we determined the prevalence of intrathecal ACVR-associated HSV TK mutations in HSE patients and compared TK genotypes of sequential HSV isolates in paired cerebrospinal fluid (CSF) and blister fluid of mucosal HSV lesions. Clinical samples were obtained from 12 HSE patients, encompassing 4 HSV type 1 (HSV-1) and 8 HSV-2 encephalitis patients. HSV DNA load was determined by real-time PCR and complete HSV TK gene sequences were obtained by nested PCR followed by Sanger sequencing. All HSV-1 HSE patients contained viral TK mutations encompassing 30 unique nucleotide and 13 distinct amino acid mutations. By contrast, a total of 5 unique nucleotide and 4 distinct amino acid changes were detected in 7 of 8 HSV-2 patients. Detected mutations were identified as natural polymorphisms located in non-conserved HSV TK gene regions. ACV therapy did not induce the emergence of ACVR-associated HSV TK mutations in consecutive CSF and mucocutaneous samples of 5 individual patients. Phenotypic susceptibility analysis of these mucocutaneous HSV isolates demonstrated ACV-sensitive virus in 2 HSV-1 HSE patients, whereas in two HSV-2 HSE patients ACVR virus was detected in the absence of known ACVR-associated TK mutations. In conclusion, we did not detect intrathecal ACVR-associated TK mutations in HSV isolates obtained from 12 HSE patients

    Literature review - Energy saving potential of user-centered integrated lighting solutions

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    Measures for the reduction of electric energy loads for lighting have predominantly focussed on increasing the efficiency of lighting systems. This efficiency has now reached levels unthinkable a few decades ago. However, a focus on mere efficiency is physically limiting, and does not necessarily ensure that the anticipated energy savings actually materialize. There are technical and non-technical reasons because of which effective integration of lighting solutions and their controls, and thus a reduction in energy use, does not happen. This literature review aims to assess the energy saving potential of integrated daylight and electric lighting design and controls, especially with respect to user preferences and behaviour. It does so by collecting available scientific knowledge and experience on daylighting, electric lighting, and related control systems, as well as on effective strategies for their integration. Based on this knowledge, the review suggests design processes, innovative design strategies and design solutions which – if implemented appropriately – could improve user comfort, health, well-being and productivity, while saving energy as well as the operation and maintenance of lighting systems. The review highlights also regulatory, technical, and design challenges hindering energy savings. Potential energy savings are reported from the retrieved studies. However, these savings derived from separate studies are dependent on their specific contexts, which lowers the ecological validity of the findings. Studies on strategies based on behavioural interventions, like information, feedback, and social norms, did not report energy saving performance. This is an interesting conclusion, since the papers indicate high potentials that deserve further exploration. Quantifying potential savings is fundamental to fostering large scale adoption of user-driven strategies, since this would allow at least a rough estimation of returns for the investors. However, such quantification requires that studies are designed with an inter-disciplinary approach. The literature also shows that strategies, where there is more communication between façade and lighting designers, are more successful in integrated design, which calls for more communication between stakeholders in future building processes
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