LEDs for photons, physiology and food.

Lighting based on light-emitting diodes (LEDs) not only is more energy efficient than traditional lighting, but also enables improved performance and control. The colour, intensity and distribution of light can now be controlled with unprecedented precision, enabling light to be used both as a signal for specific physiological responses in humans and plants, and as an efficient fuel for fresh food production. Here we show how a broad and improved understanding of the physiological responses to light will facilitate greater energy savings and provide health and productivity benefits that have not previously been associated with lighting.

["Wider Den Nächtlichen Unfug"-Bielefeld's Street Lighting from 1853 to the 1880s as a Securatization Infrastructure and Tool for Self-Discipline]. / "Wider den nächtlichen Unfug" ­ Die Bielefelder Straßenbeleuchtung von 1853 bis in die 1880er Jahre als versicherheitlichende Infrastruktur und Mittel der Selbstdisziplinierung.

This article deals with the change in safety requirements and technological possibilities in the course of industrialization by looking at the establishment of street lighting in Bielefeld in the 19th century. As will be shown, the development from oil to gas lanterns coincided with a change in the security needs of the urban middle class. It was the technical possibilities of gas lighting to penetrate the urban space at night that made marginalized groups of people who were perceived as a security risk visible. This, together with the bourgeois internalization of the disciplinary effects of light, made this infrastructure possible in Bielefeld. While the urban populations of the pre-modern and early 19th century were still skeptical or dismissive of lanterns, by the mid-19th century their installation was already part of decidedly urban bourgeois demands for more safety in the areas of personal, economic and traffic safety. The lantern thus changed from an instrument of pre-modern visibility to an instrument of constant visibility in the modern age, which at the same time led to new lines of conflict when the expansion and extension of lighting was not as comprehensive as demanded by the urban bourgeoisie. In addition to the changes and conjunctures of security needs in the course of industrialization, Bielefeld also shows that an internalization of the concept of sovereignty by no means meant the absence of conflict. On the basis of administrative acts and petitions, the history of Bielefeld's street lighting is placed in a larger transformation of security, technology and urban spatial design from the perspective of historical security research, drawing on Foucoult's concept of gouvernmentalité. The results show that the history of technology and infrastructure can significantly deepen and contextualize the findings of historical security research. The use and expectations of technology were an essential part of a new understanding of security, as well as the socially segmented organization of urban space through a sometimes precarious alliance of different groups of actors.

The conquest of the dark spaces: An experimental approach to lighting systems in Paleolithic caves.

Artificial lighting was a crucial physical resource for expanding complex social and economic behavior in Paleolithic groups. Furthermore, the control of fire allowed the development of the first symbolic behavior in deep caves, around 176 ky BP. These activities would increase during the Upper Paleolithic, when lighting residues proliferated at these sites. The physical peculiarities of Paleolithic lighting resources are very poorly understood, although this is a key aspect for the study of human activity within caves and other dark contexts. In this work, we characterize the main Paleolithic lighting systems (e.g., wooden torches, portable fat lamps, and fireplaces) through empirical observations and experimental archeology in an endokarstic context. Furthermore, each lighting system's characteristic combustion residues were identified to achieve a better identification for the archaeological record. The experiments are based on an exhaustive review of archaeological information about this topic. Besides, we apply the estimated luminous data of a Paleolithic cave with Paleolithic art (Atxurra in northern Spain) in 3D through GIS technology to delve into the archeologic implications of illumination in Paleolithic underground activities.

Reintroduction of a classic vitamin D ultraviolet source.

As early as 1930 sunlamps claiming to provide ultraviolet (UV) exposure to make vitamin D were sold to the public in the US and Canada for home use. Today even with dietary supplementation of vitamin D many people do not get enough solar UV exposure to maintain sufficient vitamin D levels. There is growing interest in the availability of sunlamps for this purpose. The original Sperti Sunlamp, with label claiming vitamin D benefit was approved by the American Medical Association in 1940 as a sunlamp. This intermediate pressure mercury lamps ultraviolet B emission lines, at 297, 302, and 313 nm are able to convert 7-dehydrocholesterol in the skin to vitamin pre-D3 initiating the natural process of vitamin D formation. Today's KBD Vitamin D lamp, an updated model of the earlier type source. In order to comply with modern safety guidance, the source is filtered to remove unnecessary UVC radiation and is equipped with a timer to control the dose administered. The 5 min timer provides an exposure, at 20 in. from the user's skin, of one standard erythemal dose (SED). The SED represents a suberythemal dose for even the most sensitive skin type I individual.

How cold light was introduced to arthroscopy.

In 1954, in a landmark publication, H. H. Hopkins reported that images could be transmitted through glass fibers. This stimulated many investigations and, in 1957, B. Hirschowitz at the University of Michigan, succeeded in constructing a much-needed flexible gastroscope using optic glass fibers. Coating of the fibers by glass of lower refractive index was the next major step forward. Optical fibers were thus insulated and the accuracy of the transmitted image and the light transmission capacity of the fibers were enhanced. Working with American Cystoscope Makers Inc, L. Curtiss and H. Hett were the first to use glass fibers for illumination in an endoscope, producing a flexible ureteroscope in 1960. The light transmitted by the fibers was named "cold light" because it produced little heat, but the term had been used before for other types of illumination. The first arthroscope equipped with cold light was Watanabe's arthroscope No. 22 built by Tsunekichi Fukuyo in 1967. However, Watanabe was not satisfied with the new instrument and he still preferred the conventionally illuminated No. 21 arthroscope with the offset tungsten bulb at his tip. After R. W. Jackson reintroduced the technique to North America, most American pioneers used this conventionally illuminated arthroscope as well. But the early European arthroscopists had cold light instruments made by the German manufacturers R. Wolf and K. Storz since 1969. These rod-lens cold light instruments expanded in all markets during the following decade.

[Philipp Bozzini (1773-1809): The endoscopic idealist]. / Philipp Bozzini (1773-1809): Der endoskopische Idealist.

Philipp Bozzini was born in Mainz on the 25th May 1773. In 1794 he moved to Jena to continue his studies under Gottfried Gruner. After his first comprehensive report on the Lichtleiter (light conductor) (1806), he returned to Mainz, obtained his doctorate, and became a practicing physician. His report on the Lichtleiter created great interest; he was the first person to construct an autonomous endoscope. Against all criticism, Bozzini started an international discussion, based on his awkward Lichtleiter, which brought his idea to an extensive medical public.

Building beauty: physiognomy on the gas-lit stage.

From 1816 onwards, London theatres began to install gas-lighting systems to replace candles. In addition to allowing theatre managers to adjust the level of illumination, gas lights offered greater brightness and visibility for the audience. Actors had to adjust to this new level of exposure that threatened their ability to "look the part." Until this illuminating moment, there had been little need for makeup and actors to adhere to the principles of physiognomy--a system that correlated character traits to facial features. Under the new harsh glare of the gas lights, both the faces of the actors and the theatres themselves were found wanting.

Clar as Mud? Origins of the head mirror: A historical note.

In Europe, the name "Clar" immediately evokes to any otorhinolaryngologist the classic head mirror that remains a symbol of our profession. Yet, the origin of Clar has never been investigated. In this clinical and historical review, based on an Internet and PubMed database search together with perusal of Fischer's Biographical Lexikon, the authors seek to elucidate this medical enigma. The data presented suggest that Clar was not a physician but rather a term picked by the company that designed the mirror by the end of the 19th century to underscore the bright and sharp view provided by this then innovative medical device. © 2015 Wiley Periodicals, Inc. Head Neck 38: 930-932, 2016.

Origins of the binocular head mirror: The mystery of Dr. Clar, clarified.

BACKGROUND: The origin of Dr. Clar's forehead mirror remains a mystery. The aim of this study is to track the roots of this eponym anew to find a definitive answer. METHODS: Historical, notably by the analysis of the reports of medical meetings and the content of instrument trade catalogs of the corresponding epoch. RESULTS: Konrad or Conrad Clar (1844-1904) was an Austrian balneologist and geologist particularly interested in laryngological examination. He notably invented a lighting apparatus in 1874, his famous forehead mirror in 1886, and a handgrip for laryngological instruments in 1901. CONCLUSIONS: Konrad Clar is the man behind the eponymous Dr. Clar's mirror. This study allowed to definitively confirm this statement.

Organic mass spectrometry in archaeology: evidence for Brassicaceae seed oil in Egyptian ceramic lamps.

An analytical procedure based on alkaline hydrolysis and silylation followed by GC/MS analysis was employed to study the formation of characteristic acidic compounds and the development of a distinctive chromatographic pattern in the course of accelerated ageing tests on Brassicaceae seed oil. On the basis of mass spectra of trimethylsilyl derivatives, the main degradation products were identified as alpha,omega-dicarboxylic, omega-hydroxycarboxylic and dihydroxycarboxylic acids, including 11,12-dihydroxyeicosanoic acid and 13,14-dihydroxydocosanoic acid. The mass spectra of both these compounds are characterised by fragment ions arising from the alpha cleavage of the bond between the two vicinal trimethylsiloxy groups, resulting in fragments at m/z 215 and 345 for 11,12-dihydroxyeicosanoic acid, and at m/z 215 and 373 for 13,14-dihydroxydocosanoic acid. Other significant fragment ion-radicals from rearrangement process at m/z [M - 90](+*), [M - 142](+*), 204 as well as fragment ions at m/z [M - 15](+), [M - 105](+), 217 are present in the mass spectra of both the compounds. The results obtained for reference materials were compared with those relating to archaeological organic materials recovered in Egyptian pottery lamps. The occurrence of the same characteristic degradation products found in the reference materials subjected to accelerated ageing indicates an unambiguous origin for the organic archaeological remains and represents the chemical evidence for the use of oil from seeds of Brassicaceae as illuminant.

[The sixtieth anniversary of Miodonski's paraboloid head lamp reflector]. / Szescdziesieciolecie czolowego reflektora parabolicznego Miodonskiego.

On the 60th anniversary of the elaboration by Miodonski of the optical solutions and his construction of the Paraboloid Headlamp and its application to clinical practice, the author compares its characteristics with other types of lamp used in otolaryngology on the example of Clar's Headlamp and Headmirror. This comparison shows that even now Miodonski's Paraboloid Headlamp due to its qualities, has no equal. The merits of Miodonski's Headlamp are as follows: 1. Permits a change of the axis of illumination under sterile condition; 2. Gives the most powerful light; 3. Permits binocular inspection of very narrow and long canals and ducts allowing for enlargement from the time that Miodonski added a magnifying and mobilizing lens to his headlamp in 1961.