Modern aquarium lighting

Astronomers consider light pollution to be a growing problem, however few studies have addressed potential effects of light pollution on wildlife. Sunlight is believed to initiate song in many bird species. If light initiates song, then light pollution may be influencing avian song behavior at a population level. This hypothesis predicts that birds breeding in areas with large amounts of artificial light will begin singing earlier in the day than birds in areas with little artificial light. Birds in highly illuminated areas might begin singing earlier than did birds in those same areas in previous years when artificial light levels were known to be, or were presumably, lower. Also, birds should begin singing earlier within a site on brightly lit nights. In 2002 and 2003 I documented initiation of morning song by breeding American Robins (Turdus migratorius) in areas with differing intensity of artificial nocturnal light. I compared my observations among sites and against historical studies. Robin populations in areas with large amounts of artificial light frequently began their morning chorus during true night. Chorus initiation time, relative to civil twilight, was positively correlated with amount of artificial light present during true night. Robin choruses in areas with little, or presumably little, artificial light have almost never begun during true night, instead appearing to track the onset of civil twilight. Proliferation of artificial nocturnal light may be strongly affecting singing behavior of American Robins at a population level.

To investigate possible causes of embryonic and neonatal mortality in a group of captive Fijian iguanas (Brachylophus fasciatus and Brachylophus vitiensis), the vitamin D status of adults in the colony was compared with that of agamid and iguanid lizards either housed in indoor enclosures under artificial ultraviolet light or exposed to natural sunlight (wild-caught or captive animals housed outdoors). Those under artificial lighting had a significantly lower vitamin D status than those housed exclusively outdoors, whereas the vitamin D status of Fijian iguanas that had received intermittent exposure to natural sunlight was intermediate and not significantly different from that of animals housed exclusively outdoors. However, eggs from some of these Fijian iguanas had substantially lower vitamin D content than eggs from outdoor iguanid and agamid animals. Artificial ultraviolet light, therefore, might not be an adequate substitute for natural sunlight to maintain vitamin D status of lizards. This possible inadequacy may be because either artificial ultraviolet light has a lower intensity of the wavelengths that induce vitamin D than does sunlight or the intensity of the artificial lighting is not sufficient.

One major, yet poorly studied, change in the environment is nocturnal light pollution, which strongly alters habitats of nocturnally active species. Artificial night lighting is often considered as driving force behind rapid moth population declines in severely illuminated countries. To understand these declines, the question remains whether artificial light causes only increased mortality or also sublethal effects. We show that moths subjected to artificial night lighting spend less time feeding than moths in darkness, with the shortest time under light conditions rich in short wavelength radiation. These findings provide evidence for sublethal effects contributing to moth population declines. Because effects are strong under various types of light compared with dark conditions, the potential of spectral alterations as a conservation tool may be overestimated. Therefore, restoration and maintenance of darkness in illuminated areas is essential for reversing declines of moth populations.

<abstract> <bold>Abstract.</bold> The study was conducted to investigate whether manipulating the daylight intensity, the overnight artificial light colors and duration could affect the growth performance of Xiaoshan broiler chicken, a variety in China. All of 200 female chickens were reared under yellow LED (30 lux) for 12 h at night from Day 1 to 12, and then randomly divided into two groups based on different daylight intensity: group 1 (208.44 lux) and group 2 (72.78lux). In each group, 60 broilers were exposed to six artificial light color treatments: without artificial light (N), white LED (W), red LED (R), blue LED (B), green LED (G) and yellow LED (Y) for 8 h overnight; 40 broilers were reared in four yellow light duration treatments: none artificial light (Y0), 4 h (Y4), 8 h (Y8) and 12 h (Y12) at night. All the artificial light intensity controlled at 15 lux approximately. Feed conversion ratio (FCR), Body weight (BW), uniformity of BW were determined every two weeks. At the end of experiment, we found that, in group 1, the BW of Y was higher than N(P≤0.1), while the BW of Y4 was lower than Y8 and Y12(P≤0.1). The BW gain and uniformity of Y8 was higher than the other three duration treatments, which was found both in group 1 and 2. Comparing group 1 to 2, we found that, in light duration treatments, the mean BW gain and FCR of group 2 was separately 94.87g higher and 0.09 lower than group 1, while in light color treatments, the mean BW gain and uniformity of group 2 was 83.00 g and 0.01 higher than group 1 respectively. These results suggested: ①8 h light duration might be a better photoperiod for Xiaoshan chicken in this rearing pattern; ② the lower daylight intensity would promote a better growth performance, it would be an important factor for this kind of poultry production.

An understanding of light and its interaction with matter is essential to produce images. As the modeling of light sources, light transport and light reflection improves, it becomes possible to render images with increasing realism. The central motivation behind this thesis is to improve realism in computer graphics images by more accurate local shading models and to assist the user to obtain the desired lighting effects with these more complex models. The first part of the thesis addresses the problem of rendering surfaces illuminated by extended (linear and area) light sources. To compute the light reflected by a surface element in a given direction, one needs to determine the unoccluded regions (shadowing) of each light source and then to compute the light reflection (shading) from each of these regions. Traditionally, point light sources are distributed on the lights to approximate both the shadowing and the shading. Instead, an efficient analytical solution is developed for the shading. Shadowing from extended light sources is a fairly expensive process. To give some insights on the complexity of computing shadows, some properties of shadows and algorithms are presented. To reduce the cost of computing shadows from linear light sources, two acceleration schemes, extended from ray tracing, are introduced and evaluated. The second part of this thesis addresses the problem of achieving a desired shading effect by building up systems of constraints. This approach is called inverse shading. It allows a user to obtain a desired lighting effect by interacting directly with the scene model. An interactive modeling system has been built to study the introduction of rendering issues into the modeling process itself. Two rendering aspects are considered: shading and shadows. By specifying a highlight position and size, the unique direction of a directional light source as well as the surface glossiness are determined. Interactively moving this highlight on the surface redefines the light direction while changing its size redefines the surface glossiness. By manipulating shadow volumes (the volume within which a particular light cannot be completely seen), the light source definition and position can be modified. By assigning colours to various points in a 3D scene, information about the colour of a surface as well as other surface characteristics can be deduced. This relatively new concept of defining the causes by manipulating the effects is expected to have a major impact on the design of future computer graphics modeling systems. It begins a new family of tools for the design of more intuitive user interfaces.

Quail Product (Coturnix coturnix japonica) in the form of meat and eggs is a variation of the source of animal protein for human consumption. Like other poultry cultivation of intensive, maintaining the scale cultivation of quail in need of maintenance and good governance to obtain maximum results and profitable. One of the important things in a maintenance program is a good quail cage lighting. Quail is an organism that is sensitive to stimuli of light, light is required to regulate various biological processes, including the reproductive system. Light energy can be obtained from natural and artificial light. This research aims to use artificial light, which is monochromatic light to obtain basic information about aspects of the reproductive system of quail regarding the condition of the ovaries and reproductive tract. Monochromatic light is a type of visible light with the frequency of a single wavelength. Treatment consists of lighting from above 4 groups, namely the use of monochromatic light LED lights red, green, and blue with 15 lux and the light intensity control using a 15 watt incandescent bulb. All treatments began at 4-week-old quail to 9 weeks, from 5:00 p.m. to 07:00 o'clock. The parameters in this study were ovarian weight, number of hierarchical follicles, length and weight of the reproductive tract. This study using Completely Randomized Design (CRD) with replications is not the same. Data generated in this study were analyzed using the Analysis Of Variance (ANOVA) if there is a real difference then conducted further tests duncan. The results of this study showed that monochromatic light of red, green, and blue can affect ovarian weight and the weight of the reproductive tract, but has not given a real influence on the length of the reproductive tract and the number of follicles. In conclusion, the artificial light in the form of monochromatic light can be used as an alternative to the cultivation of quail to produce an optimal product.

The ecological effects of light pollution are becoming better understood, especially in birds. Recent studies have shown that several bird species can use street lighting to extend activity into the night during the breeding season. However, most of these studies are correlational and little is known about the effects of artificial night lighting on the timing of activities outside the breeding season. During winter, low temperatures and short days may limit foraging opportunities and can negatively affect survival of resident birds. However, night lighting may allow them to expand the time niche available for foraging. Here, we report on a study where we repeatedly manipulated the amount of night lighting during early winter at automated feeding stations in a natural forest. We used video‐recordings at the feeders to determine the time of the first (at dawn) and last (at dusk) foraging visits for six songbird species. We predicted that all species, and in particular the naturally early‐foraging species, would advance their daily onset of foraging during the mornings with night lighting, but would show minimal or no delays in their daily cessation of foraging during the lighted evenings. We found that two early‐foraging species, the blue tit and the great tit, started foraging earlier during the experimentally lighted mornings. However, in great tits, this effect was weak and restricted to nights with inclement weather. The light treatment did not have any effect on the start of foraging in the willow/marsh tit, the nuthatch, the European jay, and the blackbird. Artificial night lighting did not cause later foraging at dusk in any of the six species. Overall, our results suggest that artificial light during winter has only small effects on timing of foraging. We discuss these findings and the importance of temperature and winter weather in shaping the observed foraging patterns.

Although studies have shown that light affects sleep in polar populations, the sample size of most studies is small. This meta-analysis provides the first systematic review of the effects of summer glare, spring and fall moderate daylight, and artificial lighting on general sleep problems (sleep duration, efficiency, and delay). This analysis included 18 studies involving 986 participants. We calculated the random effect size via an evidence-based meta-analysis that analysed the effect of bright/auxiliary light on sleep and the effect of three different types of light on sleep compared with conventional light. There was no significant correlation between specific light types and sleep duration. Intense summer light has a negative effect on sleep time and efficiency. Moderate, natural light in spring and autumn effectively delayed sleep but could not improve sleep efficiency. For artificial fill light, neither blue light nor enhanced white light has been found to have a significant effect. In summary, summer light has a detrimental effect on sleep in polar populations, and moderate natural light may be superior to conventional light. However, specific strategies to improve sleep and artificial lighting in polar populations must be explored further.

SummaryWhile recent studies explore the negative impacts of light pollution on arthropods, few studies investigated community-level responses to artificial light. Using an array of landscaping lights and pitfall traps, we track community composition over 15 consecutive days and nights, including a five-night pre-light period, a five-night during-light period, and a five-night post-light period. Our results highlight a trophic-level response to artificial nighttime lighting with shifts in the presence and abundance of predators, scavengers, parasites, and herbivores. We show that associated trophic shifts occurred immediately upon the introduction of artificial light at night and are limited to nocturnal communities. Lastly, trophic levels reverted to their pre-light state, suggesting many short-term changes in communities are likely the result of behavioral shifts. These trophic shifts may become common as light pollution increases, implicating artificial light as a cause of global arthropod community change and highlighting light pollution’s role in global herbivorous arthropod decline.

Abstract. Title of the paper: Influence of artificial and natural light on behaviour during collection of semen and on spermatological parameters in rabbit bucks 39 bucks of New Zealand White hybrids were kept Single over one year under three different light conditions (natural light – NL – with window – floor – relation of 1 : 20 and 27 Lux; artificial light – AL – with 8 or 16 hours light a day and a mean intensity of 60 Lux) and semen was collected once fortnight to analyse parameters of quality. At the same time sexual activity of bucks during collection of semen was assessed. Under NL conditions the highest sexual activity of male rabbits was found. But, decreasing length of day light in autumn led to a decrease in sexual activity. Best results for nearly all investigated semen parameters were detected in bucks kept under AL with 8 hours light a day.

Culturally dependent human social behaviours involving artificial light usage can potentially affect light pollution patterns and thereby impact the night‐time ecology in populated areas, although to date this has not been examined globally. By analysing continuous (monthly), highly resolved, spatially explicit data on global night lights (Visible and Infrared Imaging Radiometer Suite–Day/Night Band‐VIIRS‐DNB; 2014–2019) with circular statistical techniques, we evaluated whether macro‐cultural activities involving social aggregations and the use of artificial lights shape annual lighting patterns globally. Scheduled routines associated with cultural‐specific festivities appear to be important drivers of observed seasonal patterns in urban night‐time lights. For instance, the display of Christmas lights between Christmas and Epiphany Day celebrations (December–January) coincides with the annual peak in urban night‐time light intensity in Christian countries. Analogously, night celebrations during the Holy Month of Ramadam (from May to July) or the month‐long period of Karthika Masam (from October to November) fits with annual night light peaks in Muslim and Hindu countries. Annual peaks of urban light intensity in China and Vietnam also match with Chinese and Vietnamese (Tê't) New Year celebrations (January–February). In contrast, predominantly Buddhist countries, which do not have such prominent and prolonged celebrations involving artificial lights, show a relatively uniform distribution of night light peaks throughout the annual cycle. Social behaviour and sociocultural contexts help explain how people modify the global nightscape and contribute to light pollution globally. Understanding the cultural contexts responsible for peaks in artificial light usage is an important first step if humans are to mitigate any deleterious effects associated with global increases in night‐time light pollution. Read the free Plain Language Summary for this article on the Journal blog.

Floating MIL-88A(Fe)@expanded perlites catalyst for continuous photo-Fenton degradation toward tetracyclines under artificial light and real solar light

This paper illustrates the possibility of measuring chlorophyll (Chl) content and Chl fluorescence parameters by the solar-induced Chl fluorescence (SIF) method using the Fraunhofer line depth (FLD) principle, and compares the results with the standard measurement methods. A high-spectral resolution HR2000+ and an ordinary USB4000 spectrometer were used to measure leaf reflectance under solar and artificial light, respectively, to estimate Chl fluorescence. Using leaves of Capsicum annuum cv. 'Sven' (paprika), the relationships between the Chl content and the steady-state Chl fluorescence near oxygen absorption bands of O2B (686nm) and O2A (760nm), measured under artificial and solar light at different growing stages of leaves, were evaluated. The Chl fluorescence yields of ΦF 686nm/ΦF 760nm ratios obtained from both methods correlated well with the Chl content (steady-state solar light: R(2) = 0.73; artificial light: R(2) = 0.94). The SIF method was less accurate for Chl content estimation when Chl content was high. The steady-state solar-induced Chl fluorescence yield ratio correlated very well with the artificial-light-induced one (R(2) = 0.84). A new methodology is then presented to estimate photochemical yield of photosystem II (ΦPSII) from the SIF measurements, which was verified against the standard Chl fluorescence measurement method (pulse-amplitude modulated method). The high coefficient of determination (R(2) = 0.74) between the ΦPSII of the two methods shows that photosynthesis process parameters can be successfully estimated using the presented methodology.

Computer-generated imagery has become a central point in large and quickly growing areas such as computer animation, visual effects, architecture, high-quality visualization, and product design. A common requirement to all these areas is the efficient simulation of light transport from the light source to the sensor for image synthesis. This is a challenging task, as light can travel along all kinds of paths, and some paths are hard to find when computing the result numerically. The process of light propagation in a virtual scene is described by a path integral equation. This path integral is defined over the path space, the space of all possible light paths, on which photons travel from a light source to a virtual sensor. Monte Carlo approaches are employed for computing the path integral, where paths are stochastically generated (sampled). The integration, to compute an image of a virtual scene, in this space is challenging because of the mathematical properties of the integrand. In addition, the demand for both image quality and quantity requires shorter image rendering times, while imposing higher scene complexity at the same time. We provide several solutions to the problems arising with difficult light paths, especially these involving specular and glossy materials, as well as improve the rendering convergence with difficult illumination effects. Some physical phenomena, such as perfectly specular reflection, cause singularities in the path integral, and thus are hard or even impossible to sample. We propose an approach to adaptively smooth difficult components of light transport, which makes them samplable while still ensuring convergence to the exact solution. It uses regularization for paths which cannot be sampled in an unbiased way. To introduce as little bias as possible, we selectively regularize individual interactions along paths, and also derive the regularization consistency conditions. Additionally, in order to control the bias introduced by kernel smoothing, which is another means to sample complex light transport, we developed an adaptive bandwidth selection method. We have also analyzed the convergence rate for kernel smoothing methods in light transport. On the other hand, even not perfectly specular, i.e., glossy, materials can be as difficult to sample. We propose a new way for representing light paths for more efficient exploration of the path space. Based on this, we propose a new mutation strategy, to be used with Markov chain Monte Carlo methods such as Metropolis light transport, which is well-suited for all configurations of surface scattering. A different yet related problem is the creation of virtual scenes with photorealistic lighting. It can be challenging because it often requires interactive feedback and edits to the scene that are propagated consistently. To alleviate this process, we propose a set of visualization and manipulation tools, which allow the designers to grasp virtual illumination and to alter the physical laws of light transport for convenient illumination setup and analysis, as well as for achieving artistic goals.

This paper examines the epistemological model based upon the Enlightenment paradigm that underlies Modern Western thought and discusses other forms of writing and production of knowledge. Based on the the work of Michel Foucault, Walter Benjamin, Giorgio Agamben and others, we consider the production of knowledge in darkness. We start out with an evaluation of the effects of an epistemology of light and the potential of thought in the absence of light. We present an analysis of the relationship of that epistemology with forms of organization and urban lighting, as well as the production of invisible subjectivities. In a writing exercise conducted in a zone of shadows, we relate a story which binds the production of light and shadow and their productive power within contemporary urban society. Finally, this study affirms the power of shadows and the need to devise strategies that allow us to write in or with darkness and with those invisible subjectivities which inhabit it.Keywords: epistemology, writing, cities, subjectivities, powerResumoNesse artigo refletimos sobre o modelo epistemológico pautado na ideia de luzes constituinte do pensamento Ocidental Moderno, discutindo outras formas de escrever e produzir conhecimento. A partir de autores como Michel Foucault, Walter Benjamin e Giorgio Agamben, propomos uma reflexão sobre a produção do conhecimento no escuro. Iniciamos abordando os efeitos da epistemologia da luminosidade e a potência de se pensar nas sombras. Em seguida, analisamos a relação dessa epistemologia com as formas de organização e iluminação das cidades e a produção de subjetividades invisíveis. Em um exercício de escrita a partir de uma zona sombria, trazemos uma história que amarra a produção de luzes e sombras e seu poder produtivo na sociedade urbana contemporânea. Ao final, afirmamos a potência das sombras e a necessidade de construção de estratégias que nos permitam escrever no e com o escuro e com aquelas subjetividades invisíveis que o habitam.Palavras-chave: epistemologia, escrita, cidade, subjetividades, potência AbstractThis paper examines the epistemological model based upon the Enlightenment paradigm that underlies Modern Western thought and discusses other forms of writing and production of knowledge. Based on the the work of Michel Foucault, Walter Benjamin, Giorgio Agamben and others, we consider the production of knowledge in darkness. We start out with an evaluation of the effects of an epistemology of light and the potential of thought in the absence of light. We present an analysis of the relationship of that epistemology with forms of organization and urban lighting, as well as the production of invisible subjectivities. In a writing exercise conducted in a zone of shadows, we relate a story which binds the production of light and shadow and their productive power within contemporary urban society. Finally, this study affirms the power of shadows and the need to devise strategies that allow us to write in or with darkness and with those invisible subjectivities which inhabit it.Keywords: epistemology, writing, cities, subjectivities, powerAbstractThis paper examines the epistemological model based upon the Enlightenment paradigm that underlies Modern Western thought and discusses other forms of writing and production of knowledge. Based on the the work of Michel Foucault, Walter Benjamin, Giorgio Agamben and others, we consider the production of knowledge in darkness. We start out with an evaluation of the effects of an epistemology of light and the potential of thought in the absence of light. We present an analysis of the relationship of that epistemology with forms of organization and urban lighting, as well as the production of invisible subjectivities. In a writing exercise conducted in a zone of shadows, we relate a story which binds the production of light and shadow and their productive power within contemporary urban society. Finally, this study affirms the power of shadows and the need to devise strategies that allow us to write in or with darkness and with those invisible subjectivities which inhabit it.Keywords: epistemology, writing, cities, subjectivities, power