LEDitSHAKE: a lighting system to optimize the secondary metabolite content of plant cell suspension cultures.

Plant secondary metabolites are widely used in the food, cosmetic and pharmaceutical industries. They can be extracted from sterile grown plant cell suspension cultures, but yields and quality strongly depend on the cultivation environment, including optimal illumination. Current shaking incubators do not allow different light wavelengths, intensities and photoperiods to be tested in parallel. We therefore developed LEDitSHAKE, a system for multiplexed customized illumination within a single shaking incubator. We used 3D printing to integrate light-emitting diode assemblies into flask housings, allowing 12 different lighting conditions (spectrum, intensity and photoperiod) to be tested simultaneously. We did a proof of principle of LEDitSHAKE using the system to optimize anthocyanin production in grapevine cell suspension cultures. The effect of 24 different light compositions on the total anthocyanin content of grapevine cell suspension cultures was determined using a Design of Experiments approach. We predicted the optimal lighting conditions for the upregulation and downregulation of 30 anthocyanins and found that short-wavelength light (blue, UV) maximized the concentration of most anthocyanins, whereas long-wavelength light (red) had the opposite effect. Therefore our results demonstrate proof of principle that the LEDitSHAKE system is suitable for the optimization of processes based on plant cell suspension cultures.

Natural and Simulated Solar Radiation.

The extra-terrestrial solar spectrum corresponds approximately to a black body of temperature about 5,800 K, with the ultraviolet region accounting for almost 8% of the total solar energy. Terrestrial solar spectral irradiance peaks at around 500 nm in the blue-green region, whereas the diffuse component peaks in the UVAI-blue region of the spectrum, with the infrared component comprising almost entirely direct radiation. Several factors impact on the magnitude and spectral profile of terrestrial solar spectral irradiance, and these include solar elevation, reflection from land and sea, air pollution, altitude above sea level and cloud cover. Measurements of erythemal UV from a number of ground-based networks around the world indicate an approximate 4-fold difference in ambient annual exposure between Australia and countries in northern Europe. In the absence of measured data, models to compute solar UV irradiance are a useful tool for studying the impact of variables on the UV climate. Simulated sources of sunlight based on a xenon arc lamp can be configured to give a close match to the spectral output of natural sunlight at wavelengths less than about 350 nm, and these are invaluable in the laboratory determination of sunscreen performance, notably the Sun Protection Factor (SPF). However, the divergence -between natural and simulated solar spectra at longer wavelengths may explain why SPFs measured in natural sunlight are less than those determined in the laboratory.

Twenty-seven-gauge endoilluminator-assisted scleral buckling using a wide-field viewing system: Case report.

RATIONALE: We report a new scleral buckling technique using a 27-gauge endoilluminator and a wide-field viewing system to overcome the limitations of conventional indirect ophthalmoscope-methods and "chandelier-assisted" surgery. PATIENT CONCERNS: A 26-year-old female patient visited the local clinic for floaters and lower visual field defects in her left eye that had occurred 5 days prior. DIAGNOSES: On fundus examination, upper retinal detachment without macular involvement and an atrophic hole was observed in her left eye. INTERVENTIONS: Under general anesthesia and after perilimbal conjunctival incision, extraocular muscle isolation, and traction with black silk, a 27-gauge trocar-cannula was inserted 90° away from the retinal break, 4 mm away from the limbus. Under wide-field viewing using a contact lens, the fundus was observed through a surgical microscope. Retinal break was evaluated and cryopexy was performed with careful movement of the endoilluminator, paying attention to damage to the lens. The surgeon could accurately and freely control the direction of the illumination tip to obtain a brighter view of the region of interest. OUTCOMES: There were no complications associated with trocar cannula incision or the illuminator. The retina was successfully reattached. LESSONS: Twenty seven gauge endoilluminator-assisted scleral buckling is an easy and safe procedure and provides better control over and free adjustment of the light direction, thus overcoming the limitations of chandelier-assisted surgery.

Assessing optimal colour and illumination to facilitate reading.

PURPOSE: This study examined the effectiveness of the LuxIQ, the Apple iPad and a smart bulb in assessing optimal colour and illumination to facilitate reading in younger, older and visually impaired adults. METHODS: Participants read standardised texts at baseline (normal lighting/no device), then using the Apple iPad, LuxIQ and smart bulb, with their normal vision (20/20 condition) and using a simulated reduction in visual acuity/contrast sensitivity (20/80 condition). Visually impaired participants followed the same procedure used in the 20/80 condition. RESULTS: There was a significant interaction between condition and device in younger, F(1.5, 43.51) = 30.41, p < 0.001, ω2  = 0.34 and older, F(1.5, 4.51) = 4.51, p = 0.03, ω2  = 0.05 adults with normal vision, and there was a significant effect of device, F(2, 58) = 5.95, p = 0.004, ω2  = 0.12 in visually impaired adults. In the 20/20 condition, age and colour predicted reading speed, F(3, 176) = 36.25, p < 0.001, Adj. R2  = 0.37, whereas age, lighting and colour predicted reading speed, F(3, 176) = 36.25, p < 0.001, Adj. R2  = 0.37 in the 20/80 condition. In the visual impairment condition, lighting, colour and impairment severity predicted reading speed, F(3, 85) = 10.10, p < 0.001, Adj. R2  = 0.24. CONCLUSIONS: The clinical implications of this study are that reading speeds improve in individuals with low vision under improved lighting conditions, specifically, with higher levels of luminance and colour temperature. The effectiveness of the devices varied across groups; however, the LuxIQ was the only device to improve reading speeds from baseline in older adults with visual impairments.

Evaluation of Potential Optical Radiation Hazards from LED Flashlights.

We performed optical radiation safety evaluations of LED flashlights to determine if they pose potential ocular hazards. Six commercially available flashlight samples were randomly selected from various vendors online. They were evaluated in accordance with specifications provided in the American National Standards Institute/Illuminating Engineering Society of North America (ANSI/IESNA) Standards RP 27.1 and RP 27.3. Four of the flashlights were found to have relatively high blue-light-weighted radiance values with short times (40 to 50 s) to reach the exposure limit specified in RP 27.1. These flashlights are in Risk Group 2 and present a moderate risk for retinal damage. Two of the flashlights are in Risk Group 1 and present a low risk for retinal damage. None of the flashlights present an ultraviolet (UV) radiation hazard or a retinal thermal hazard. Cautionary labeling on the packaging as required by RP 27.3 and on the flashlight handle is recommended for flashlights and on other handheld light sources that are in Risk Group 2 or Risk Group 3.

A Basic Study on the Performance Evaluation of a Movable Light Shelf with a Rolling Reflector That Can Change Reflectivity to Improve the Visual Environment.

In recent years, the need for comfortable visual environments in indoor spaces has increased energy use in buildings. There have been diverse studies on using a light shelf to solve this problem. It is an effective system that allows external natural light deep into indoor spaces through reflection. However, prior studies have used light shelves with a fixed reflectivity, and there are few studies on improving the visual environment through light shelf control. Therefore, this study proposes a movable light shelf with a rolling reflector that can change the reflectivity. To achieve these objectives, we conducted a performance evaluation of the system's ability to save energy and improve the visual environment. This study built a real scale testbed and conducted a performance evaluation by deriving values for lighting energy consumption, uniformity, and luminance contrast depending on the light shelf variables. We conclude that (1) the light shelf system achieved an energy savings of 13.6% and 5.7%, respectively, compared to a fixed type light shelf, whose reflectivity cannot be changed, and a traditional movable light shelf; (2) in terms of improving the visual environment, results suggest that the visual environment could be improved using a light shelf by deriving light shelf variables that disturb indoor uniformity; and (3) the results verified glare generation conditions by deriving luminance contrast caused by the variables of light shelf angle and its reflectivity.

Visual fatigue during control room work in process industries.

BACKGROUND: Working in front of computer screens is visually demanding and related to adverse eye symptoms. Occurrence of glare further increases visual fatigue. OBJECTIVE: This paper presents results from an examination of visual ergonomics in control room environments at two Swedish process industries. METHODS: Visual conditions were examined and evaluated in nine control rooms and eighteen process operators answered questions about their perceived workload and visual experiences. RESULTS: When working in the control rooms, the mental workload was rated significantly higher by the participants, compared to experienced performance. The operators further experienced significantly higher visual fatigue and blurred vision compared to double vision and sore eyes. Visual demands were increased in conditions where contrast glare was present, as well as frequent changes of focusing distances, and low contrast between background and characters in computer screens. CONCLUSIONS: Suboptimal visual working conditions in the control rooms contributes to increased visual demands on the operators. Presence of glare is leading to visual fatigue and an unnecessary high mental load. The findings support the relevance of considering principles of general and visual ergonomics when designing and organizing work in control rooms. Workstation design should also be flexible to allow for individual and contextual adjustments.

Neural correlates of perceptual color inferences as revealed by #thedress.

Color constancy involves disambiguating the spectral characteristics of lights and surfaces, for example to distinguish red in white light from white in red light. Solving this problem appears especially challenging for bluish tints, which may be attributed more often to shading, and this bias may underlie the individual differences in whether people described the widely publicized image of #thedress as blue-black or white-gold. To probe these higher-level color inferences, we examined neural correlates of the blue-bias, using frequency-tagging and high-density electroencephalography to monitor responses to 3-Hz alternations between different color versions of #thedress. Specifically, we compared relative neural responses to the original "blue" dress image alternated with the complementary "yellow" image (formed by inverting the chromatic contrast of each pixel). This image pair produced a large modulation of the electroencephalography amplitude at the alternation frequency, consistent with a perceived contrast difference between the blue and yellow images. Furthermore, decoding topographical differences in the blue-yellow asymmetries over occipitoparietal channels predicted blue-black and white-gold observers with over 80% accuracy. The blue-yellow asymmetry was stronger than for a "red" versus "green" pair matched for the same component differences in L versus M or S versus LM chromatic contrast as the blue-yellow pair and thus cannot be accounted for by asymmetries within either precortical cardinal mechanism. Instead, the results may point to neural correlates of a higher-level perceptual representation of surface colors.

NeoSTRESS: Study of Transfer and Retrieval Environmental StressorS Upon Neonates via a Smartphone Application-Light.

OBJECTIVE: This study aimed to measure the light levels neonates would be exposed to during retrieval, determine whether this varied with transport mode, and compare them with recommended light exposure in neonatal intensive care units. We also aimed to determine the ease of use and acceptability of using the smartphone application. SETTING: A neonatal retrieval service in Brisbane, Australia. METHODS: This prospective study used the calibrated smartphone application Physics Toolbox Sensor Suite (Vieyra Software, Washington, DC). Data were collected during the outbound, nonpatient leg of 45 retrievals (25 road, 11 fixed wing aircraft, and 9 rotary aircraft journeys). Data were saved to Cloud storage and then analyzed using the PostgreSQL database. RESULTS: The median illuminance was 6 lux (interquartile range [IQR], 1-58). The maximum recorded was 93,842 lux. The median illuminance during daytime journeys was 15 lux (IQR, 2-77). The median light level for night journeys was 1 lux (IQR, 0.5-8). Illuminance exceeded the recommended level (600 lux) for 2.1% of all journey time. CONCLUSION: Retrieved neonates can be exposed to light in excess of recommended neonatal intensive care unit levels, including extremely bright light. It is feasible, with good staff acceptability, for a calibrated smartphone application to be used in place of a light meter.

Nurses' Satisfaction With Patient Room Lighting Conditions: A Study of Nurses in Four Hospitals With Differences in the Environment of Care.

PURPOSE: The present study aims to contribute to current knowledge about nurses' perceived importance of lighting in patient rooms and to compare these perceptions across different ages, work shifts, (day and night), and environments of care (traditional and contemporary). BACKGROUND: Creating an environment of care in patient rooms that successfully balances energy efficiency concerns with the holistic needs of patients, families, and caregivers poses a major challenge for future lighting systems. This study adds to a growing evidence base on the effects of lighting on nurses' job performance, job satisfaction, and overall perceptions of the environment. METHOD: Survey responses from 138 participants working in medical-surgical units in four hospitals were analyzed using a mixed-methods approach, with three of the hospitals having lighting systems characterized as providing a traditional environment of care (TEC) and the other hospital having lighting systems characterized as providing a contemporary environment of care (CEC). RESULTS: No significant differences were found based on age or work shift, but several significant differences were found between participants working in the hospital with a CEC and those working in hospitals with a TEC. Participants from the hospital with a CEC lighting system consistently reported higher lighting quality, fewer patient complaints, and less need for supplemental lighting than the participants from the three hospitals with TEC lighting systems. CONCLUSION: The results of this study provide evidence that innovative lighting approaches and technologies are worth considering as an investment by hospital administrators looking to improve perceptions of the patient room environment.

Standardizing serial photography for assessing and monitoring vitiligo: A core set of international recommendations for essential clinical and technical specifications.

BACKGROUND: Clinical photography is an important component of the initial assessment and follow-up of patients with vitiligo in clinical practice and research settings. Standardization of this photographic process is essential to achieve useful, high-quality, and comparable photographs over time. OBJECTIVE: The aim is to develop an international consensus for a core set of recommendations for standardized vitiligo clinical photography. METHODS: Based an international meeting of vitiligo experts, a standard operating procedure was developed for vitiligo photography in daily practice and research settings. This protocol was subsequently reviewed by 20 vitiligo experts until agreement was reached. RESULTS: The resulting protocol includes a set of 10 and 15 photographs for clinical practice and research purposes, respectively. The photographic series are based on anatomic units included in the Vitiligo Extent Score. Furthermore, graphic representations of standardized positioning and suggestions for guidelines to standardize the process (background color, lighting, position marking, scales, materials, instruments) for both color and ultraviolet photographs are described. CONCLUSIONS: This consensus-based protocol for vitiligo photography will harmonize imaging for both clinical practice, translational research, and clinical trials. It can improve outcome assessment, foster multicenter collaboration, and promote better communication with patients regarding outcomes of treatment.

Effects of Lighting Quality on Working Efficiency of Workers in Office Building in Tanzania.

Background: In this era of Information Communication Technology, a high-quality working environment is essential to the occupants. Providing quantity rather the quality of work environments is very common in most of the least developed countries, including Tanzania. Existing research asserts that poor indoor environmental quality such as lighting has a detrimental effect on human health, and in case of the office working population, it also affects their work performance. This study aims to analyze the effects of the lighting quality on working efficiency of workers in Tanzania. Methods: Four representative offices from the administration building at Mbeya University of Science and Technology were investigated from June to September 2018. The customized questionnaire survey tool was administered to the randomly selected occupants to survey their perceptions about the quality of lighting in their workplace and its influence on their health and work efficiency. Physical observation and illuminance distribution measurements were also conducted. Results: The statistical analysis indicates that the majority of the occupants are less satisfied with the lighting quality in their working environment, and some respondents reported that it significantly affected their work efficiency and wellbeing. The average desk illuminance and uniformity level were found to be below the recommended values of the Chartered Institution of Building Services Engineers (CIBSE) and the International Commission on lighting (CIE). Conclusion: Despite the suggested improvement measures, this research emphasizes that poorly articulated work environment can adversely affect the productivity and work efficiency of the workers. The workers in such condition are also exposed to occupational diseases. Thus, providing a healthy work environment should be a fundamental right of the workers.

Estructura de las unidades de cuidados intensivos de anestesia: recomendaciones de la Sección de Cuidados Intensivos de la Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor (SEDAR) / Structure of the anesthesia intensive care units: recommendations of the Intensive Care Section of the Spanish Society of Anaesthesiology

ANTECEDENTES Y OBJETIVO: Los objetivos de la Sección de Cuidados Intensivos de la Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor (SCI-SEDAR) con el presente trabajo son: establecer nuevas recomendaciones adaptando los estándares publicados por el Ministerio de Sanidad y Política Social, y alineadas con las principales guías internacionales, y desarrollar una herramienta de mejora de la calidad y la eficiencia. MATERIALES Y MÉTODO: A lo largo de 2018, 3 miembros de la SCI-SEDAR definieron la metodología, desarrollaron las recomendaciones y seleccionaron al panel de expertos. Debido a la limitada evidencia de buena parte de las recomendaciones y a la importante variabilidad estructural de las unidades de cuidados intensivos de anestesia actuales, se optó por un abordaje Delphi modificado para determinar el grado de consenso. RESULTADOS: Un total de 24 expertos de 21 instituciones constituyeron el grupo de expertos del presente trabajo. Se establecieron 175 recomendaciones sobre 8 apartados, incluyendo 129 con consenso fuerte y 46 con consenso débil. CONCLUSIONES: La SCI-SEDAR estableció las recomendaciones estructurales de las unidades de cuidados intensivos de anestesia que deberán guiar la renovación o la creación de nuevas unidades

BACKGROUND AND OBJECTIVE: In this article, the Intensive Care Section of the Spanish Society of Anesthesiology (SCI-SEDAR) establishes new recommendations based on the standards published by the Ministry of Health, Consumer Affairs and Social Welfare and aligned with the principle international guidelines, and develops a tool to improve quality and efficiency. MATERIALS AND METHOD: Over a 12-month period (2018), 3 members of the SCI-SEDAR defined the methodology, developed the recommendations and selected the panel of experts. Due to the limited evidence available for many of the recommendations and the significant structural differences between existing anesthesia intensive care units, we chose a modified Delphi approach to determine the degree of consensus. RESULTS: The panel consisted of 24 experts from 21 institutions. The group put forward 175 recommendations on 8 sections, including 129 with strong consensus and 46 with weak consensus. CONCLUSIONS: The SCI-SEDAR has established a series of structural recommendations that should be used when renovating or creating new anesthesia intensive care units

Structure of the Anesthesia Intensive Care Units: Recommendations of the Intensive Care Section of the Spanish Society of Anaesthesiology. / Estructura de las unidades de cuidados intensivos de anestesia: recomendaciones de la Sección de Cuidados Intensivos de la Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor (SEDAR).

BACKGROUND AND OBJECTIVE: In this article, the Intensive Care Section of the Spanish Society of Anesthesiology (SCI-SEDAR) establishes new recommendations based on the standards published by the Ministry of Health, Consumer Affairs and Social Welfare and aligned with the principle international guidelines, and develops a tool to improve quality and efficiency. MATERIALS AND METHOD: Over a 12-month period (2018), 3 members of the SCI-SEDAR defined the methodology, developed the recommendations and selected the panel of experts. Due to the limited evidence available for many of the recommendations and the significant structural differences between existing anesthesia intensive care units, we chose a modified Delphi approach to determine the degree of consensus. RESULTS: The panel consisted of 24 experts from 21 institutions. The group put forward 175 recommendations on 8 sections, including 129 with strong consensus and 46 with weak consensus. CONCLUSIONS: The SCI-SEDAR has established a series of structural recommendations that should be used when renovating or creating new anesthesia intensive care units.

Is Use of Warning Lights and Sirens Associated With Increased Risk of Ambulance Crashes? A Contemporary Analysis Using National EMS Information System (NEMSIS) Data.

STUDY OBJECTIVE: We compare reported crash rates for US ambulances responding to or transporting patients from a 911 emergency scene with or without lights and sirens. Our null hypothesis is that there will be no difference in the rate of ambulance crashes whether lights and sirens are used. METHODS: For this retrospective cohort study, we used the 2016 National EMS Information System data set to identify 911 scene responses and subsequent patient transports by transport-capable emergency medical services (EMS) units. We used the system's "response mode to scene" and "transport mode from scene" fields to determine lights and sirens use. We used the "type of response delay" and "type of transport delay" fields to identify responses and transports that were delayed because of a crash involving the ambulance. We calculated the rate of crash-related delays per 100,000 responses or transports and used multivariable logistic regression with clustered (by agency) standard errors to calculate adjusted odds ratios (AORs) (with 95% confidence intervals [CIs]) for the association between crash-related delays and lights and sirens use for responses and transports separately. RESULTS: Among 19 million included 911 scene responses, the response phase crash rate was 4.6 of 100,000 without lights and sirens and 5.4 of 100,000 with lights and sirens (AOR 1.5; 95% CI 1.2 to 1.9). For the transport phase, the crash rate was 7.0 of 100,000 without lights and sirens and 17.1 of 100,000 with lights and sirens (AOR 2.9; 95% CI 2.2 to 3.9). Excluding responses and transports with only partial lights and sirens use did not meaningfully alter the results (response AOR 1.5, 95% CI 1.2 to 1.9; transport AOR 2.8, 95% CI 2.1 to 3.8). CONCLUSION: Ambulance use of lights and sirens is associated with increased risk of ambulance crashes. The association is greatest during the transport phase. EMS providers should weigh these risks against any potential time savings associated with lights and sirens use.

Adherence to components of Health Promoting Schools in schools of Bengaluru, India.

Schools provide a crucial platform for health promotion as the school years are a vital stage in one's life, where lifelong general and oral health-related behaviours are developed and established. The components of Health Promoting Schools (HPSs) suggested by World Health Organization provide guidance for facilitating health promotion within this setting. This study aimed to assess the adherence to the components of HPSs amongst schools in Bengaluru, India utilizing a comprehensive tool developed for the purpose. A cross-sectional survey was conducted among randomly selected 61 schools. Data were collected through structured interviews with the head of the schools, direct observation of school premises and verification of records. The significant findings of the study were that 80.3% of the schools had proper ventilation and separate washrooms for boys and girls, 83.6 and 88.5% of the schools had natural light and adequate water supply correspondingly. Only 39.3% of the schools had washrooms that were cleaned daily, and 55.7% of the schools were in proximity to business that sold tobacco products. Oral health education was not integrated into the curriculum in 39.3% of the schools, and 29.5% of the schools had no playgrounds. The study tool appeared to be sensitive in identifying the finer components of HPSs, indicating the lack of strict adherence to the components of HPSs in Bengaluru. This information can be utilized to design appropriate interventions at micro, meso and macro level to strengthen the capacity of schools for the attainment of health promotion.

In-Use Photostability Practice and Regulatory Evaluation for Pharmaceutical Products in an Age of Light-Emitting Diode Light Sources.

This article describes how the increased use of energy-efficient solid-state light sources (e.g., light-emitting diode [LED]-based illumination) in hospitals, pharmacies, and at home can help alleviate concerns of photodegradation for pharmaceuticals. LED light sources, unlike fluorescent ones, do not have spurious spectral contributions <400 nm. Because photostability is primarily evaluated in the International Council of Harmonization Q1B tests with older fluorescent bulb standards (International Organization for Standardization 10977), the amount of photodegradation observed can over-predict what happens in reality, as products are increasingly being stored and used in environments fitted with LED bulbs. Because photodegradation is premised on light absorption by a compound of interest (or a photosensitizer), one can use the overlap between the spectral distribution of a light source and the absorption spectra of a given compound to estimate if photodegradation is a possibility. Based on the absorption spectra of a sample of 150 pharmaceutical compounds in development, only 15% would meet the required overlap to be a candidate to undergo direct photodegradation in the presence of LED lights, against a baseline of 55% of compounds that would, when considering regular fluorescent lights. Biological drug products such as peptides and monoclonal antibodies are also expected to benefit from the use of more efficient solid-state lighting.

A Global Perspective for Sustainable Highway Tunnel Lighting Regulations: Greater Road Safety with a Lower Environmental Impact.

Tunnel lighting installations function 24 h a day, 365 days a year. These infrastructures have increased exponentially and now connect quite distant locations, even on different continents. This has led European administrations and international regulatory bodies to establish regulations for tunnel safety with the lowest environmental impact. However, until now, these regulations have almost exclusively focused on traffic safety, and relegated sustainability to the background. Even though they recognize the need to reduce energy consumption, they do not propose any tools for doing so. Given the impact of these installations and the lack of a specific regulatory framework, Asian countries will soon be forced either to update previous standards for tunnel lighting or elaborate new ones. A better understanding of the weaknesses of European regulations combined with a willingness to embrace innovation could position Asia as a world leader in the regulation of more sustainable road tunnels. The objective of this research was to improve the sustainability of tunnel lighting installations through new regulations or amendments to existing ones, without impairing the mental well-being of users, who could potentially be affected by energy-saving measures. Accordingly, this paper presents and analyzes a broad proposal for formulating tunnel lighting regulations. The originality of this proposal lies in the fact that it integrates road safety, lower environmental impact, and user well-being. Furthermore, it is expected to broaden the perspective of regulatory bodies and public administrations with regard to tunnel installations, which would ultimately enhance their sustainability.

Bright environmental light improves the sleepiness of nightshift ICU nurses.

BACKGROUND: Shift work can disturb circadian homeostasis and result in fatigue, excessive sleepiness, and reduced quality of life. Light therapy has been shown to impart positive effects in night shift workers. We sought to determine whether or not prolonged exposure to bright light during a night shift reduces sleepiness and enhances psychomotor performance among ICU nurses. METHODS: This is a single-center randomized, crossover clinical trial at a surgical trauma ICU. ICU nurses working a night shift were exposed to a 10-h period of high illuminance (1500-2000 lx) white light compared to standard ambient fluorescent lighting of the hospital. They then completed the Stanford Sleepiness Scale and the Psychomotor Vigilance Test. The primary and secondary endpoints were analyzed using the paired t test. A p value <0.05 was considered significant. RESULTS: A total of 43 matched pairs completed both lighting exposures and were analyzed. When exposed to high illuminance lighting subjects experienced reduced sleepiness scores on the Stanford Sleepiness Scale than when exposed to standard hospital lighting: mean (sem) 2.6 (0.2) vs. 3.0 (0.2), p = 0.03. However, they committed more psychomotor errors: 2.3 (0.2) vs. 1.7 (0.2), p = 0.03. CONCLUSIONS: A bright lighting environment for ICU nurses working the night shift reduces sleepiness but increases the number of psychomotor errors. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03331822 . Retrospectively registered on 6 November 2017.

Nighttime lights as a proxy for human development at the local level.

Nighttime lights, calculated from weather satellite recordings, are increasingly used by social scientists as a proxy for economic activity or economic development in subnational regions of developing countries where disaggregated data from statistical offices are not available. However, so far, our understanding of what nighttime lights capture in these countries is limited. We use geo-referenced Demographic and Health Surveys (DHS) from 29 African countries to construct indicators of household wealth, education and health for DHS cluster locations as well as for grid cells of roughly 50 × 50 km. We show that nighttime lights are positively associated with these location-specific indicators of human development, and that the variation in nighttime lights can explain a substantial share in the variation in these indicators. We conclude that nighttime lights are a good proxy for human development at the local level.