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This paper presents an experiment on the effect of light on the perception of paintings. The experiment was performed in a test-room where a typical museum exhibition set-up was simulated. Two different paintings were shown to 44 participants, under different light scenes obtained by using tuneable LED (Light Emitting Diode) wallwashers. To set the light scenes, the following parameters were modified: correlated colour temperature of the lighting, illuminance on the painting and the colour of the background wall. Participants answered a questionnaire to assess the perception of the paintings' colours, the lighting conditions and the pleasantness of the exhibition set-up. The results demonstrated that illuminance is the parameter mainly affecting perception, for both paintings. However, correlated colour temperature and wall colour, as well as the combination of the three different considered parameters, can more or less influence perception depending on the chromatic composition of the painting. [ABSTRACT FROM AUTHOR]

This paper reports the results of measurements performed in a test room to investigate the impact of using different wall colours and light scenes on indoor lighting quality. Eye level spectral irradiances were measured for a user located inside the room and seated at a desk. These measurements allow the use of the Irradiance Toolbox, which makes it possible to calculate equivalent illuminances for the photopigments in the human eye. Moreover, the CIECAM02 colour appearance model was used to investigate the variations in hue and chroma values of the different wall colours when changing the light scene. The results demonstrate that there are significant variations in eye level spectral irradiance distributions, photoreceptor stimulation and hue and chroma values with different combinations of wall colours and light scenes. [ABSTRACT FROM AUTHOR]

The study presented in this paper aims to evaluate if and how the environment affects the circadian impact of a light source by predicting circadian stimulus (CS) resulting from the exposure to different light scenes, using equations reported in studies by Rea et al. The main findings are: (1) Above 600 lx at eye level the increase of CS is little; (2) Between 50 lx and 200 lx at the eye level an increase of only 50 lx determines a significant increase of CS; (3) Light sources with correlated colour temperatures between 2900 K and 4200 K have similar impacts on the circadian system according to the calculation method used; (4) Even an almost neutral environment affects the circadian impact of a light source. [ABSTRACT FROM PUBLISHER]

In order to evaluate the circadian effects of light, an approach based only on a circadian sensitivity function makes it possible to easily obtain efficiency functions and action factors. However, it does not take into account the circadian human response to light stimuli, which is not linear. Non-linear models are more sophisticated and accurate but they are not easy to apply. In this paper a proposal for an easy way to evaluate the potential ‘circadian effects’ of light sources is presented. Although the model is quite simple, results are in good agreement with those obtained by means of one of the most accurate non-linear models. [ABSTRACT FROM AUTHOR]

In this paper a system for obtaining the luminous intensity distribution of a small light source, based on high dynamic range imaging, is described. The system uses a dark room, a lambertian screen and a video-luminance-meter mounted on a workbench. The luminous intensity distribution of the light source is derived from the illuminance map on the screen by applying the photometric inverse law. The geometry of the system is presented and the measurements’ uncertainties are estimated. Finally, an application to a LED source is presented. [ABSTRACT FROM PUBLISHER]

Abstract: Light induces not only visual responses but also non-visual effects, indeed it affects performance, mood, attention and influences the synchronization of the biological clock. Duration, timing, intensity and the spectral power distribution of the light that reaches the eyes can have influence on human circadian rhythm and consequently on health. Given the important impact of the non-visual responses on people wellbeing, developing a model that allows lighting designers to predict them is a fundamental goal. In this paper a case study is reported: a series of measurements were carried out in a University classroom in order to study daylight and electric light characteristics and also their impact on the human circadian system by calculating melatonin suppression. The results obtained show that not only the intensity but also the SPD of the light received by the eyes plays a significant role on circadian response and the spectral characteristics of internal and external surfaces influence the SPD and therefore the CCT of the light that hits the eyes. Although the working behavior of the human circadian system is not completely understood, the results obtained give the designers new points of view to better evaluate lighting quality and its implications in indoor environments. [Copyright &y& Elsevier]

Abstract: After decades of intense research, the effects of light on the circadian system have been proved to exist. By studying the relationship between human physiology and light, research has also advanced to the point that there is the belief that these effects will be in future regulated by Standards. Establishing a direct connection among the fundamental radiometric, the traditional photometric and the new circadian approach to lighting becomes a fundamental step for introducing new concepts to lighting practitioners. This theoretical paper has the aim to propose a correlation between the traditional approach to lighting design with the new and still not definitely defined circadian approach by means of a photometric to circadian correlation factor. By this way, once the circadian efficiency function will be experimentally determined, technicians will be able to evaluate also from a numerical point of view the impact of lighting on the circadian system, adding health considerations to the traditional design process. [Copyright &y& Elsevier]

Abstract: Since the end of the 1990s, good quality lighting was that which balanced the needs of humans, economic and environmental issues, and architectural design. Recent studies aimed to find a correlation between environmental lighting and human performance and health, with positive results. What is known, is that insufficient or inappropriate light exposure can disrupt standard human rhythms which may result in adverse consequences for performance, safety, health. By studying the relationship between human physiology and light, research in photobiology has advanced to the point where some attempts to foresee what the lighting practice will be in future. The question is if lighting practice and lighting practitioners are ready for changes. This paper has the aim of introducing the recent discoveries in photobiology to those interested in lighting design, starting from a critical overview of traditional parameters since now used in lighting applications and then presenting a new theoretical approach to introduce non-visual parameters for lighting applications. [Copyright &y& Elsevier]

Recent availability of video-cameras with CCD-type sensors (charge coupled device) has proved to be particularly stimulating for all those applications requiring photometric measurements, above all for the measurement of luminance values related to the physical and technical qualities of a built environment. This method allows the instantaneous capture of an image, thus enabling collection of luminance values relating to the points of measurement; this in turn leads to the evaluation of luminance distribution and lighting levels of the surfaces that make up the environment.Setting up this system requires the following basic configuration: a photopic filter V(λ), an optic interface, a computer equipped with an appropriate card for the capture and digitalisation of the acquired image (the “frame grabber”) and, finally, suitable software for the processing of collected data.In this article a detailed description of this acquisition system is reported, and subsequently a report on the procedure adopted for its calibration so as to enable the capture of relevant photometric values. Final analysis and validation of results are carried out by means of field test. A case study of CCD photometer application has been then performed using a basic software tool autonomously developed to evaluate indoor lighting level; the luminance map of a diffuse light source has been used as “input” data for the developed software, and the “output” data, i.e. illumination levels, have been then compared with measured values. [Copyright &y& Elsevier]

Up to now the evaluation of illuminances on workplane and luminances of indoor surfaces has been usually performed using the well-known CIE 'Clear' and 'Overcast' standard luminance distributions. However, these models are not always close enough to the real sky conditions that may occur in several climatic zones worldwide. An international effort (IDMP) has been initiated to establish other typical luminance distributions, and different models, as functions of climatic data, have been proposed. Starting from the availability of the standard luminance distributions, this paper presents the first step of development of a daylighting calculation program. A sensitivity analysis of sky dome discretisation was performed with the aim of calculating of horizontal outdoor diffuse illuminances due to the sky component associated with each luminance distribution, and the paper presents the results. [ABSTRACT FROM PUBLISHER]

A study was carried out in an office building to investigate daylight impact comparing SUPERLITE 1.01 and LUMENMICRO 5 simulation results with measured data.Referring to the CIE standard Clear (with direct sun) and Overcast sky luminance distributions, calculated illuminance and daylight factor data for the work plane are compared with on-site data collected under real sky conditions. The main aim of the paper is not a comparative evaluation of simulation programs, but to define the meaning and/or uncertainty attached to the quoted results from the programs. [ABSTRACT FROM PUBLISHER]

[Display omitted] • DAYKE-Italy is a project that investigated daylighting in 5 Italian universities. • A survey was distributed to students (N = 542) on perception of daylight in classrooms. • DIVA+ALFA simulations were run to calculate daylight, circadian and energy metrics. • Most metrics have significant statistical correlation with subjective responses. • Highest correlation was found for DFm, ALE, and circadian EML. Results from the DAYKE-Italy project are presented. An investigation on daylighting in eight classrooms in five Italian universities was carried out through a combined approach: an ad-hoc survey administered to students to investigate how they perceive daylight in classroom, and numerical simulations (DIVA + ALFA) to calculate a set of objective metrics (daylight, circadian, and energy-related). A sample of 542 questionnaires was collected through two sessions and the subjective judgments were correlated to objective metrics. Results from descriptive and statistical analyses showed: (i) the correlation was significant for all daylight metrics: among them, average daylight factor and annual light exposure performed higher correlations compared to daylight autonomy, spatial daylight autonomy and useful daylight illuminance; (ii) rooms with a scarce or an optimal daylight provision (according to standards) were rated with comparable subjective score; (iii) the equivalent melanopic lux showed a higher correlation than daylight metrics based on the horizontal workplane; (iv) energy saving up to 50% can be achieved in the presence of high daylight provision and through daylight responsive controls; however, a relamping of fluorescent systems with LED system is recommended to optimize the consumption; furthermore, estimated saving correlated significantly with objective metrics. [ABSTRACT FROM AUTHOR]

Light plays a crucial role in affecting the melatonin secretion process, and consequently the sleep-wake cycle. Research has demonstrated that the main characteristics of lighting affecting the so-called circadian rhythms are spectrum, light levels, spatial pattern and temporal pattern (i.e., duration of exposure, timing and previous exposure history). Considering that today people spend most of their time in indoor environments, the light dose they receive strictly depends on the characteristics of the spaces where they live: location and orientation of the building, dimensions of the windows, presence of external obstructions, geometric characteristics of the space, optical properties of walls and furniture. Understanding the interaction mechanism between light and architecture is fundamental to design non-visually comfortable spaces. The goal of the paper is to deepen this complex issue. It is divided into two parts: a brief historical excursus about the relationship between lighting practice and architecture throughout the centuries and a review of the available research works about the topic. The analysis demonstrates that despite the efforts of the research, numerous open questions still remain, and they are mostly due to the lack of a shared and clear method to evaluate the effects of lighting on circadian rhythm regulation.

In the industrialized part of the world, an increasing number of people live the old age without too many restrictions due to illness or physiological impairment. This group is known as the young elderly. On the contrary, a consistent part of seniors develops a greater number of medical conditions and become more and more dependent, these are the old elderly. The first cause of tooth lost in industrialized word is periodontitis that generally strikes people older than 40 years and determines serious detriment of the stomatognatic organ. Smoking and stress are risk factors for periodontitis that are common and shared between young, adult, and older age. Diabetes mellitus, obesity, and osteoporosis are very frequent pathological situations in older age. They have been identified as cofactors in the progression of periodontitis. Many dental associations recognize the importance of continued research on oral fluids diagnostics and welcome the development of rapid point-of-care tests providing accurate measurements of clinically validated biomarkers. At present, well-studied molecules associated with host response factors and with derived tissue destruction mediators have been proposed as diagnostic biomarkers for periodontitis detected in the oral fluids.

Kawasaki disease can be characterized by rare complications or by unusual associations. One of these is autoimmune hemolytic anaemia that has been observed seldom up to now. The Authors report a case with this rare association, compare it with cases observed before, and put forth the hypothesis that autoimmune anaemia during Kawasaki disease can be linked to numerous immunological alterations present in mucocutaneous lymph node syndrome. They moreover advise to abstain in these cases from corticosteroid therapy, both to avoid complications, and because, as happened in their patient, this kind of autoimmune hemolytic anaemia can regress spontaneously.

Epstein-Barr virus is seldom the causative agent of a prolonged atypical illness, known as chronic mononucleosis syndrome, characterized by a persistent pattern of clinical manifestations and by a defective immune response to specific viral antigens. This paper refers about 6 children for whom clinical and serological findings suggest the chronic Epstein-Barr virus infection. The authors believe that this chronic state might be explained by the unusual antibody pattern to EBV virus, with the persistent presence of anti-EA and the absence of anti-EBNA titers, expression of a reduced EBV-specific cytotoxic T cell activity.

The Authors describe three infants with visceral leishmaniasis in whom bioptic research (in marrow, spleen and liver) has not demonstrated presence of leishmania. They remark this unusual aspect of visceral leishmaniasis in infant and debate the epidemiological, diagnostic, and therapeutic aspects of these cases.

The case of a patient with tetanic hypocalcemia secondary to celiac disease initially diagnosed as chronic hypoparathyroidism is reported. The rarity and clinical peculiarities of the case are underlined and its pathogenesis discussed with particular reference to the difficulties it presents in terms of differential diagnosis.

The dietary habits of 174 infants under 6 months old and suffering from enteritis were analysed revealing a high incidence of feeding errors (almost always feeding with artificial formulas, wrong concentration of milk powder, failure to sterilise the bottle and the water used to dilute the milk, too early administration of undiluted, unboiled bottled cow's milk, too early and incorrect weaning). Such mistakes appeared to be linked to the poor economic and sociocultural conditions of the families concerned. It is claimed that dietary errors conditioned by the poor economic and sociocultural conditions encountered may have favoured the onset of enteritis and that the adequate prophylaxis of acute infantile enteritis will depend on improving people's dietary habits and living conditions.

The authors describe two cases of Kawasaki disease, one of whose is an "incomplete" form, and emphasize the importance to know this "new" disease in the differential diagnosis of febrile exanthemas of childhood. A complete diagnostic walk-up failed to find out a probably, while change of some immunological and flogistic parameters has permitted to suppose a probably immuno-mediated pathogenesis of Kawasaki disease. Both patients healed without any sequelae after therapy with low doses of salicylate for ten months, in confirmation of usefulness of this treatment in the prevention of heart complications of Kawasaki disease.