Daily illuminance levels affect pituitary prolactin in male rats

1989 ◽  
Vol 120 (4) ◽  
pp. 429-434 ◽  
Author(s):  
Maija-Liisa Laakso ◽  
Tarja Porkka-Heiskanen ◽  
Aino Alila ◽  
Susanna Kajander ◽  
Dag Stenberg ◽  
...  
Keyword(s):  
Serum Levels ◽  
Causative Factor ◽  
Male Rats ◽  
Adaptation Period ◽  
Artificial Lighting ◽  
Natural Lighting ◽  
Lighting Conditions ◽  
Illuminance Level ◽  
Pituitary Prolactin

Abstract. The 24-h patterns of melatonin, PRL, and gonadotropins in male rats maintained under natural lighting conditions have been found to differ from the patterns in rats kept under artificial lighting. In the present experiments we studied the role of different daily illuminances as a possible causative factor for the variation of the hormonal patterns. Three groups of male rats were kept under artificial lighting conditions (12 h on/12 h off), where the daily illuminance was 550, 110 or 25 lux. After a 7-day adaptation period the pineal content of melatonin, the serum levels of LH, FSH and PRL, and the pituitary content of these hormones were measured by RIAs in samples taken at 10.00, 13.00, 22.00 and 01.00 h. The patterns of pineal melatonin were equal in all three groups. The variation of daily illuminance did not change the serum levels of LH, FSH and PRL or the pituitary content of the gonadotropins. However, the pituitary content of PRL during the light phase was inversely related to the illuminance. The results suggest that the intensity of daily lighting in the studied range does not affect the patterns of melatonin or gonadotropins, but the synthesis of prolactin may be significantly regulated by the daily illuminance level.

Twenty-Four-Hour Patterns of Pineal Melatonin and Pituitary and Plasma Prolactin in Male Rats under ‘Natural’ and Artificial Lighting Conditions

1988 ◽  
Vol 48 (3) ◽  
pp. 308-313 ◽  
Author(s):  
Maija-Liisa Laakso ◽  
Tarja Porkka-Heiskanen ◽  
Aino Alila ◽  
Mikael Peder ◽  
Gunnar Johansson
Keyword(s):  
Male Rats ◽  
Plasma Prolactin ◽  
Artificial Lighting ◽  
Pineal Melatonin ◽  
Lighting Conditions

Building Information Modeling with Static and Dynamic Daylight Analysis

2013 ◽  
Vol 855 ◽  
pp. 255-258 ◽  
Author(s):  
Martin Jamnický
Keyword(s):  
Fossil Fuels ◽  
Building Information Modeling ◽  
Information Modeling ◽  
Internal Space ◽  
Poor Control ◽  
Artificial Lighting ◽  
Natural Lighting ◽  
Building Information ◽  
Major Factors

One of the major factors in verifying the way in which internal environments and buildings are qualified by people is daylight. The role of daylight in day to day basis and the fact of providing internal space quality make it that important. This is one of the reasons behind the constant need to integrate daylight into architecture, apart from high cost of fossil fuels or temporary electricity sources. Besides being one of the most efficient sources of energy, not to mention the fact that its completely free, there are other important aspects that should not be overlooked before entering the building. Generally, it is considered a pleasure to have daylight inside the building unless it distracts the occupants from accomplishing their daily tasks such as glare from computer screens as this can reduce productivity of offices and creates eye strain. Replacing artificial lighting with natural daylighting can be the best solution in terms of carbon footprint reduction and cutting costs to a minimum. It is essential to make sure that improper natural lighting or poor control doesnt give overheating or glare discomfort.

scholarly journals Artificial nighttime lighting impacts visual ecology links between flowers, pollinators and predators

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Emmanuelle S. Briolat ◽  
Kevin J. Gaston ◽  
Jonathan Bennie ◽  
Emma J. Rosenfeld ◽  
Jolyon Troscianko
Keyword(s):  
Interspecific Interactions ◽  
Visual Ecology ◽  
Light Sources ◽  
Artificial Lighting ◽  
Natural Lighting ◽  
Avian Predators ◽  
Lighting Conditions ◽  
Environmentally Sensitive Areas ◽  
Sexual Signalling ◽  
Environmentally Sensitive

AbstractThe nighttime environment is being altered rapidly over large areas worldwide through introduction of artificial lighting, from streetlights and other sources. This is predicted to impact the visual ecology of many organisms, affecting both their intra- and interspecific interactions. Here, we show the effects of different artificial light sources on multiple aspects of hawkmoth visual ecology, including their perception of floral signals for pollination, the potential for intraspecific sexual signalling, and the effectiveness of their visual defences against avian predators. Light sources fall into three broad categories: some that prevent use of chromatic signals for these behaviours, others that more closely mimic natural lighting conditions, and, finally, types whose effects vary with light intensity and signal colour. We find that Phosphor Converted (PC) amber LED lighting – often suggested to be less harmful to nocturnal insects – falls into this third disruptive group, with unpredictable consequences for insect visual ecology depending on distance from the light source and the colour of the objects viewed. The diversity of impacts of artificial lighting on hawkmoth visual ecology alone argues for a nuanced approach to outdoor lighting in environmentally sensitive areas, employing intensities and spectra designed to limit those effects of most significant concern.

Violation of the conditions of the insolution regime in trends of modern construction

2020 ◽  
pp. 80-85
Author(s):  
Myroslava Schevchuk ◽  
Svitlana Verkalets ◽  
Serhiy Schevchuk ◽  
Mykola Danylyshyn
Keyword(s):  
Residential Buildings ◽  
Light Conditions ◽  
Regulatory Requirements ◽  
Natural Health ◽  
Natural Lighting ◽  
Lighting Conditions ◽  
Building Insulation ◽  
Holding Back ◽  
The Impact

Purpose. The purpose of the work is analysis of violations of natural lighting conditions (insolation) in residential buildings, because in the modern conditions of construction the role of direct sunlight as a natural health factor has increased significantly, multi-storied buildings in cities are becoming increasingly detached from natural conditions. Method. The methodology is based on a comprehensive and objective analysis of the SSTC-R B normative document R.2.2-27: 2010 “Guidance on the Calculation of Civilian Object Insolation”. Results. It has been investigated during the process of analysis that the regulation and calculation of insolation is the most acute economic and social-legal problem. With the transition of land usage and construction to the market basis, building insulation rates have become a major factor in holding back investors, landlords and tenants from seeking to redevelop urban development in order to maximize profits. Scientific novelty. Imperfect normalization was found under the current conditions in the course of the research, which can lead to serious errors in the design and evaluation of the insulation regime of the apartment and the house as a whole. The maximum shade mask of a new home shall correspond to the maximum possible height of the projected house or to the combination of the maximum heights of each individual section at which the insolation regime in the premises of the existing house or in the surrounding area shall meet the regulatory requirements or shall not deteriorate during the normalized period of insolation. If the insolation is interrupted more than once, then for the estimated duration of the insolation, the sum of the duration of the two largest insolation periods should be taken. Practical meaning. The results of the study may be useful in further studies of violation of natural light conditions, as well as the impact of residential development on insolation processes.

scholarly journals The effects of natural light on measures of meat quality and adrenal responses to husbandry stressors in swine

1998 ◽  
Vol 78 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Nigel J. Cook ◽  
John Chang ◽  
Robert Borg ◽  
Wayne Robertson ◽  
Allan L. Schaefer
Keyword(s):  
Meat Quality ◽  
Salivary Cortisol ◽  
Natural Light ◽  
Full Spectrum ◽  
Lighting Condition ◽  
Artificial Lighting ◽  
Natural Lighting ◽  
Lighting Conditions ◽  
Cortisol Levels ◽  
Major Factors

Two groups of pigs, born and housed under artificial and natural lighting, demonstrated increases in plasma and salivary cortisol levels at the time of weaning (day 24) and following handling and transport, indicating that these husbandry practices are stressful experiences for the animals. Piglets housed under natural light had a mean plasma cortisol response to weaning of 33.7%, compared with 47.9% for pigs in the artificial-lighting condition (P < 0.03). The relative percentage of eosinophils was reduced following weaning in both groups of pigs (P < 0.04). Salivary cortisol levels were significantly increased in response to handling and transport (P < 0.0001). Also, "basal" levels of salivary cortisol were lower in pigs exposed to natural lighting (P < 0.02) but no differences in the magnitude of the response to handling and transport were evident between different lighting conditions. Male pigs raised under artificial lighting had greater fat depth than those raised under natural light (P < 0.03) and a lower lean yield (P < 0.05). The longer photoperiod and full spectrum of natural light probably entrains the circadian rhythm of cortisol to an earlier clock time and are likely to be the major factors in differential cortisol concentrations between lighting conditions. Key words: Lighting, cortisol, saliva, pigs, stress, meat quality

scholarly journals Inhibition of Nitric Oxide Synthase by L-NAME Promotes Cisplatin-Induced Nephrotoxicity in Male Rats

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Fatemeh Moslemi ◽  
Mehdi Nematbakhsh ◽  
Fatemeh Eshraghi-Jazi ◽  
Ardeshir Talebi ◽  
Hamid Nasri ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Weight Loss ◽  
Serum Levels ◽  
Female Rats ◽  
Male Rats ◽  
Group 2 ◽  
Synthase Inhibitor ◽  
Oxide Synthase ◽  
Group 1

Objective. Nitric oxide (NO) has numerous important functions in the kidney. The role of NO in cisplatin (CP)-induced nephrotoxicity is not completely understood. This study was designed to determine the role of NO synthase inhibitor (L-NAME) on the severity of CP-induced nephrotoxicity in rats. Methods. Sixty four male (M) and female (F) Wistar rats were randomly divided into eight groups. The sham groups (group 1, male, n=6 and group 2, female, n=6) received saline. Groups 3 (male, n=8) and 4 (female, n=8) were treated with L-NAME (4 mg/kg, i.p.), and groups 5 (male, n=8) and 6 (female, n=8) received CP (3 mg/kg) for 7 days. Groups 7 (male, n=8) and 8 (female, n=8) were treated with L-NAME and CP for 7 days. Results. The CP-alone treated rats showed weight loss and increase in serum levels of blood urea nitrogen (BUN) and creatinine (Cr). Coadministration of L-NAME and CP did not improve weight loss, and it increased the levels of BUN and Cr in male but not in female rats (P<0.05). CP alone increased kidney damage significantly (P<0.05 ), however, the damage induced by combination of CP and L-NAME was gender-related. Conclusion. NOS inhibition by L-NAME increased CP-induced nephrotoxicity, which was gender-related.

SEASONAL VARIATION IN THE EPISODIC SECRETION OF LUTEINIZING HORMONE AND TESTOSTERONE IN THE RAM

1976 ◽  
Vol 69 (2) ◽  
pp. 213-226 ◽  
Author(s):  
G. A. LINCOLN
Keyword(s):  
Plasma Testosterone ◽  
Domestic Sheep ◽  
Testis Size ◽  
Short Term ◽  
Artificial Lighting ◽  
Short Intervals ◽  
Lighting Conditions ◽  
Lh Releasing Hormone ◽  
Dynamic Interplay

SUMMARY Rams of an ancient breed of domestic sheep (Soay) were housed under artificial lighting conditions to study the way in which the secretion of LH and testosterone changes in relation to the mating season. Conspicuous changes were found in the short-term fluctuations in plasma LH concentrations related to the cycle of testis growth and regression; serial blood samples collected at short intervals revealed episodic peaks in plasma LH at all times, but there were changes in the frequency (lowest when the testes were regressed and highest when fully active), amplitude (lowest at the peak of testis activity, and highest during the developing phase), and duration of the peaks (shortest when the testes were regressed). In addition, the basal levels changed from being lowest in the regressed phase of the testis cycle, and highest when the gonads were most active. Plasma testosterone concentrations changed in parallel with the cycle of testis size and were correlated with the fluctuating levels of LH. Each episodic peak in plasma LH was associated with an increase in the level of testosterone, beginning after 0–30 min and rising to a peak at 60–90 min; the speed and magnitude of the response being greatest when the testes were largest, but was not correlated with the magnitude of the LH change. Injections of LH releasing hormone (5 μg) stimulated an increase in plasma LH and testosterone proportional to the endogenous fluctuations in the hormones at the various stages of the seasonal cycle; LH concentrations were raised to supra-physiological levels after the injections, while testosterone concentrations seldom exceeded the normal peak values at any stage. These observations are used to discuss the role of the hypothalamus in the control of male seasonality with emphasis on the dynamic interplay between the hypothalamus, pituitary and testis.

Role of prolactin in the photoperiodic control of moulting in the mink (Mustela vison)

1984 ◽  
Vol 103 (1) ◽  
pp. 9-15 ◽  
Author(s):  
L. Martinet ◽  
D. Allain ◽  
C. Weiner
Keyword(s):  
Physiological Role ◽  
Plasma Prolactin ◽  
Summer Solstice ◽  
Natural Lighting ◽  
Short Day ◽  
Lighting Conditions ◽  
Natural Photoperiod ◽  
Moulting Cycle ◽  
Short Days

ABSTRACT Beginning at the summer solstice adult female mink were maintained in long- or short-day photoperiods and treated with bromocriptine or prolactin. In control females kept under natural lighting conditions the moult coincided with the seasonal decrease in prolactin and resulted in the growth of a dense winter coat which was completed by the end of November. Long days, which slowed the decrease in plasma prolactin relative to animals in the natural photoperiod, induced a more or less complete moult followed by growth of a thin summer coat. On the contrary we observed an accelerated decrease in plasma prolactin concentrations followed by an early and brief moult in females kept under long days but treated with bromocriptine and in females under short days. The growth of a dense winter coat was completed by the end of September in all the females of the short-day group and in six of eleven females treated with bromocriptine. In the other five females, moult was followed by the growth of a summer coat. These results may suggest that the decline of prolactin after the summer solstice is responsible for the onset of the autumn moult, but the early, abbreviated moult and the growth of a winter coat observed in females kept under short days and treated with prolactin do not seem to support this hypothesis. However, the huge non-physiological levels of prolactin measured in the plasma of these females and the appearance of abnormal white under-hairs might suggest that the hormonal balance in this group was completely disturbed by the treatment. The physiological role of prolactin in the seasonal moulting cycle in mink is discussed. J. Endocr. (1984) 103,9–15

Lighting conditions affect serum and pituitary TSH in male rats

1990 ◽  
Vol 259 (2) ◽  
pp. E162-E169
Author(s):  
M. L. Laakso ◽  
T. Porkka-Heiskanen ◽  
D. Stenberg ◽  
G. Johansson ◽  
P. T. Mannisto
Keyword(s):  
Diurnal Variation ◽  
Adult Male ◽  
Anterior Pituitary ◽  
Male Rats ◽  
Natural Lighting ◽  
Lighting Conditions ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Serum Tsh ◽  
Tsh Levels

It has been reported that periodicity of lighting plays a role in the regulation of the function of the hypothalamus-anterior pituitary-thyroid axis in the rat. We studied whether other properties of lighting influence the levels of pituitary and serum thyrotropin (TSH) in adult male rats. The animals were reared 7 days under various lighting conditions, then trunk blood and adenohypophyses were collected at different times of the day, and TSH was measured radioimmunologically. In natural lighting conditions the diurnal variation of plasma and pituitary TSH levels was abolished, and the overall levels of plasma TSH were higher and those of pituitary TSH lower than in ordinary laboratory lighting conditions. The intensity of lighting affected the serum TSH levels; daytime serum TSH decreased in the rats under low daytime illuminances and in those under nighttime twilight instead of darkness. Changing the rate of the lighting transition at dawn and dusk had no influence on the TSH patterns. We conclude that, in addition to periodicity, other features of lighting affect the daily secretion patterns of TSH.

scholarly journals SIMULASI PENCAHAYAAN ALAMI DAN BUATAN DENGAN ECOTECT RADIANCE PADA STUDIO GAMBAR; KASUS STUDI: STUDIO GAMBAR SEKOLAH TINGGI TEKNIK MUSI PALEMBANG

2017 ◽  
Vol 10 (3) ◽  
pp. 171
Author(s):  
Tiffany Chandra ◽  
Abd. Rachmad Zahrial Amin
Keyword(s):  
Light Transmission ◽  
Initial Study ◽  
Illumination Level ◽  
The Sun ◽  
Architectural Drawing ◽  
Artificial Lighting ◽  
Natural Lighting ◽  
Average Value ◽  
Lighting Conditions ◽  
Random Samples

Abstract: Natural lighting comes from the sun, while the artificial lighting comes from artificial light (lamp). Lighting is needed to do the activities in a room, whether it is natural or artificial lighting. The amount of natural lighting depends on the location and the dimension of windows as well as the direction of the trajectory of the sun. Window, which has a larger opening, will allow much sun light. Artificial lighting depends on the types of lamp and the power of light transmission (watts). If the power of light transmission is greater, the light will be brighter. Certain activities will need different illumination level. The standard of illumination level for the studio of drawing is 750 lux because the activities require high precision. In the initial study to determine whether the lighting conditions in the studio has already met the requirement of illumination level, luxmeter is used to measure the illumination level for three days. The result of the measurement indicates that the natural lighting, which is available today, has not reached 750 lux. This study uses Ecotect Radiance Simulation Program to improve natural and artificial lighting in the studio of drawing. To achieve the actual results of the simulation of artificial lighting, the simulation uses Erco lights series LED White 72689.000 Opton which is placed 2.5 meters from the floor. The simulation shows that the average value of random samples is 1749, 7 lux. Simulation of the natural lighting uses the climate of Palembang city. Therefore, it is advisable to replace the existing artificial lighting with the lights.Keywords: natural lighting, artificial lighting, architectural drawing studioAbstrak: Pencahayaan alami adalah pencahayaan yang bersumber dari sinar matahari, sedangkan sumber pencahayaan buatan berasal dari sinar buatan (lampu). Sebuah ruang dengan segala aktivitas didalamnya membutuhkan pencahayaan, baik itu alami maupun buatan. Pencahayaan alami yang masuk ke dalam ruangan dipengaruhi oleh letak dan ukuran jendela, serta arah lintasan matahari. Semakin besar bukaan pada jendela, maka cahaya yang masuk akan semakin besar pula. Pencahayaan buatan yang maksimal dipengaruhi oleh jenis lampu dan kekuatan daya pancar (watt). Semakin besar daya yang digunakan, maka lampu tersebut akan semakin terang. Fungsi ruang yang berbeda akan membutuhkan tingkat iluminasi yang berbeda. Tingkat iluminasi standar untuk ruang studio gambar adalah 750 lux karena termasuk aktivitas yang membutuhkan ketelitian tinggi. Pada penelitian awal, yang dilakukan untuk mengetahui apakah kondisi pencahayaan pada ruang studio gambar telah memenuhi standar, dilakukan pengukuran dengan menggunakan luxmeter selama tiga hari. Hasil dari pengukuran tersebut menunjukkan bahwa pencahayaan alami yang ada saat ini belum mencapai 750 lux. Pada penelitian ini dilakukan simulasi dengan program Ecotect Radiance untuk memperbaiki pencahayaan alami dan buatan pada ruang studio gambar. Untuk mendekati hasil sebenarnya dalam simulasi pencahayaan buatan, digunakan lampu Erco seri Opton LED White 72689.000 yang diletakkan setinggi 2,5 meter dari lantai. Dari simulasi ini, diperoleh nilai rata-rata dari sampel acak sebesar 1749,7 lux. Simulasi pencahayaan alami menggunakan iklim kota Palembang. Oleh karena itu, disarankan untuk mengganti pencahayaan buatan yang ada saat ini dengan lampu tersebut.Kata kunci: pencahayaan alami, pencahayaan buatan, studio gambar

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