scholarly journals Effect of light intensities on reproductive performance, nursing behaviour and preference of rabbit does

2016 ◽  
Vol 24 (2) ◽  
pp. 139 ◽  
Author(s):  
Zs. Matics ◽  
Zs. Szendrő ◽  
I. Radnai ◽  
R. Kasza ◽  
Zs. Gerencsér
Keyword(s):  
Light Intensity ◽  
Reproductive Performance ◽  
Preference Test ◽  
High Light Intensity ◽  
Point Of View ◽  
Light Intensities ◽  
Lower Light ◽  
Net Cages ◽  
Group D ◽  
Lower Light Intensity

The aim of the experiment was to compare the reproductive performance and nursing behaviour of rabbit does reared under 2 different light intensities and observe the preference of does among cages with different light intensities. Female rabbits were randomly housed in 2 identical rooms, under the same housing conditions in wire-net cages. The 2 rooms only differed in the light intensity; group L: 150-200 lux (n=54 does, 230 inseminations), group D: 10-20 lux (n=54 does, 232 inseminations). Reproduction data from the first 5 consecutive reproductive cycles were evaluated. Nursing behaviour of the does (n = 24) was observed at the 2nd or 4th lactation. The preference of does (n=8) among 4 cages with different light intensities (10, 35, 75 or 155 lux)  as examined. There were 6-7% difference between the 2 groups in the number of kits born in total and those born alive (born total: 11.25 vs. 10.59 kits, P<0.1; liveborn: 10.75 vs. 10.00 kits, P<0.05; in groups L and D, respectively). Suckling mortality was nearly 2% higher in group D (L: 8.1, D: 10.0%; P<0.1), and in consequence the litter size of this group at 35 d of age was lower than that of the L rabbits (L: 8.75, D: 8.45 kits; P<0.05). The light intensity did not affect litter and individual weights at 35 d of age. The average numbers of daily nursing events (L: 1.23/d, D: 1.32/d), the length (L: 208±49, D: 213±43 s) and the daily distribution of nursing events were not affected by high light intensity. During the light period of the day, the darkest cage (10 lux) was the most preferred by the does (44.0, 18.6, 17.9 and 19.5% in 10, 35, 75 and 155 lux cages, respectively; P<0.001). The lower light intensity had no unambiguously unfavourable effect on the reproductive performance and nursing behaviour of the does. Based on the preference test, a lower light intensity may be advantageous from the point of view of animal welfare.

scholarly journals Light intensity regulates phototaxis, foraging and righting behaviors of the sea urchin Strongylocentrotus intermedius

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8001 ◽  
Author(s):  
Jiangnan Sun ◽  
Xiaomei Chi ◽  
Mingfang Yang ◽  
Jingyun Ding ◽  
Dongtao Shi ◽  
...  
Keyword(s):  
Light Intensity ◽  
Foraging Behavior ◽  
Sea Urchins ◽  
High Light Intensity ◽  
High Light ◽  
Strongylocentrotus Intermedius ◽  
Low Light ◽  
Low Light Intensity ◽  
Light Intensities ◽  
Significant Difference

Small sea urchins Strongylocentrotus intermedius (1–2 cm of test diameter) are exposed to different environments of light intensities after being reseeded to the sea bottom. With little information available about the behavioral responses of S. intermedius to different light intensities in the environment, we carried out an investigation on how S. intermedius is affected by three light intensity environments in terms of phototaxis, foraging and righting behaviors. They were no light (zero lx), low light intensity (24–209 lx) and high light intensity (252–2,280 lx). Light intensity had obvious different effects on phototaxis. In low light intensity, sea urchins moved more and spent significantly more time at the higher intensity (69–209 lx) (P = 0.046). S. intermedius in high light intensity, in contrast, spent significantly more time at lower intensity (252–690 lx) (P = 0.005). Unexpectedly, no significant difference of movement (average velocity and total distance covered) was found among the three light intensities (P > 0.05). Foraging behavior of S. intermedius was significantly different among the light intensities. In the no light environment, only three of ten S. intermedius found food within 7 min. In low light intensity, nine of 10 sea urchins showed successful foraging behavior to the food placed at 209 lx, which was significantly higher than the ratio of the number (two of 10) when food was placed at 24 lx (P = 0.005). In the high light intensity, in contrast, significantly less sea urchins (three of 10) found food placed at the higher light intensity (2,280 lx) compared with the lower light intensity (252 lx) (10/10, P = 0.003). Furthermore, S. intermedius showed significantly longer righting response time in the high light intensity compared with both no light (P = 0.001) and low light intensity (P = 0.031). No significant difference was found in righting behavior between no light and low light intensity (P = 0.892). The present study indicates that light intensity significantly affects phototaxis, foraging and righting behaviors of S. intermedius and that ~200 lx might be the appropriate light intensity for reseeding small S. intermedius.

Lower light intensity reduces larval aggression in matrinxã, Brycon amazonicus

2018 ◽  
Vol 151 ◽  
pp. 62-66 ◽  
Author(s):  
Ana Caroliny C. Lopes ◽  
Marle Angélica Villacorta-Correa ◽  
Thaís B. Carvalho
Keyword(s):  
Light Intensity ◽  
Lower Light ◽  
Lower Light Intensity

scholarly journals Effect of light intensity and growth substratum on plant development and production of secondary metabolites in Cordia curassavica (Jacq.) Roem. & Schult

2010 ◽  
Vol 34 (3) ◽  
pp. 417-423 ◽  
Author(s):  
Maria Terezinha Silveira Paulilo ◽  
Flávia Simão Lapa ◽  
Miriam de Barcellos Falkenberg
Keyword(s):  
Light Intensity ◽  
Root Biomass ◽  
Relative Income ◽  
High Light Intensity ◽  
High Light ◽  
Alcoholic Extract ◽  
Low Light ◽  
Fertilized Soil ◽  
Lower Light ◽  
Effect Of Light

Cordia curassavica (Jacq.) Roem. & Schult. (Boraginaceae), also referred to as Cordia verbenacea DC, has been traditionally used for medicinal purposes. This study was driven to verify the behavior of the species in similar conditions to its natural environment, such as high light intensity and sandbank soil, and in conditions of low light intensity and fertilized substratum (dystroferric red nitosoil plus earthworm humus). The growth of the plant, the income of leaf crude extracts and, in the alcoholic extract, the number of substances found in thin layer cromatography and the toxicity of the substratum was observed. The results indicated that the growth of the root biomass, stem and leaves in discharge or lower light intensity was similar, but smaller in sandbank soil than in fertilized soil. The relative income of extracts in ether of petroleum and alcohol was larger in high light intensity and fertilized substratum. The light intensity and the substratum type didn't affect the number of substances detected in the alcoholic extract or the toxicity of this extract. Stains corresponding to the rosmarinic acid were only evidenced in some samples of the alcoholic extract, not allowing the verification of the effect of the treatments about its production.

scholarly journals Implementasi Algoritma Kunang-Kunang Untuk Penjadwalan Mata Kuliah di Universitas Ma Chung

2015 ◽  
Vol 6 (4) ◽  
Author(s):  
Hendry Setiawan ◽  
Lo Hanjaya Hanafi ◽  
Kestrilia Rega Prilianti
Keyword(s):  
Light Intensity ◽  
Resource Sharing ◽  
Firefly Algorithm ◽  
Course Scheduling ◽  
S Parameters ◽  
Lower Light ◽  
University Course ◽  
Complex Matter ◽  
Lower Light Intensity

Abstract. Course scheduling is considered as a complex matter because the generated schedule must guarantee that there are no clashes of classes, lecturers, and students’ schedules. At Ma Chung University, course scheduling is still accomplished manually. Due to the limited number of rooms and lecturers r, resource sharing system is applied. This causes complication in manual scheduling. Firefly algorithm is implemented in this application to schedule the course automatically. A schedule solution is represented as a firefly. Firefly with lower light intensity will move toward firefly with higher light intensity, so that a better solution is found. Based on a scheduling test, the best light intensity value of firefly is reached when firefly algorithm’s parameters, β0 and γ, are given 1 and 10 with light intensity value of 0,0003831. Keywords: course, firefly algorithm, scheduling  Abstrak. Penjadwalan mata kuliah merupakan hal yang kompleks karena jadwal yang dihasilkan tidak hanya menjamin jadwal pertemuan semua kelas dan dosen tidak bentrok, tetapi juga menjamin jadwal pertemuan semua mahasiswa tidak bentrok. Penjadwalan mata kuliah di Universitas Ma Chung masih dilakukan secara manual. Karena jumlah kelas dan dosen yang dimiliki terbatas, maka diterapkan sistem resource sharing. Sistem resource sharing ini membuat proses penjadwalan yang dilakukan secara manual menjadi lebih rumit. Algoritma yang digunakan untuk penjadwalan mata kuliah pada aplikasi ini adalah algoritma kunang-kunang. Sebuah solusi jadwal mata kuliah dalam algoritma kunang-kunang direpresentasikan sebagai seekor kunang-kunang. Kunang-kunang dengan intensitas cahaya yang lebih rendah akan bergerak menuju kunang-kunang yang lebih terang sehingga mampu didapatkan solusi jadwal mata kuliah yang lebih baik. Berdasarkan hasil uji coba, nilai intensitas cahaya terbaik didapatkan ketika parameter algoritma kunang-kunang, β0 dimasukkan 1 dan γ dimasukkan 10 hingga didapatkan intensitas sebesar 0,0003831. Kata Kunci: algoritma kunang-kunang, mata kuliah, penjadwalan

scholarly journals A Study of the Photo-Electric Efficiency of Dye-Sensitized Solar Cells Under Lower Light Intensity

2007 ◽  
Vol 2 (4) ◽  
pp. 513-517 ◽  
Author(s):  
Hee-Je Kim ◽  
Yong-Chul Kim ◽  
Ji-Tae Hong ◽  
Mi-Jeong Kim ◽  
Hyun-Woong Seo ◽  
...  
Keyword(s):  
Solar Cells ◽  
Light Intensity ◽  
Dye Sensitized Solar Cells ◽  
Dye Sensitized ◽  
Lower Light ◽  
Sensitized Solar Cells ◽  
Lower Light Intensity

Inhibition of nighttime melatonin secretion in cattle: threshold light intensity for dairy heifers

2001 ◽  
Vol 81 (1) ◽  
pp. 153-156 ◽  
Author(s):  
T. J. Lawson ◽  
A. D. Kennedy
Keyword(s):  
Light Intensity ◽  
Key Words ◽  
Latin Square ◽  
Exposure Period ◽  
Melatonin Secretion ◽  
Melatonin Concentration ◽  
Dairy Heifers ◽  
Plasma Melatonin ◽  
Light Intensities ◽  
Lower Light

Five pre-pubertal Holstein heifers were exposed for 16 h to a light intensity of 400 lx and thereafter to intensities of 0, 50, 100, 200, or 400 lx for an additional 8 h (5 x 5 Latin square design). Exposure to all intensities inhibited (P < 0.05) melatonin secretion for the initial few hours (of the 8-h exposure period); melatonin concentration subsequently increased, particularly with the lower light intensities. Only the highest light intensity (400 lx) suppressed (P < 0.05) plasma melatonin concentrations for the entire 8-h exposure period. Key words: Threshold, supplemental, light, intensity, inhibition, melatonin, heifer

scholarly journals METABOLIC CONDITIONS IN CHLORELLA

1948 ◽  
Vol 32 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Jack Myers ◽  
Marian Cramer
Keyword(s):  
Light Intensity ◽  
Nitrogen Assimilation ◽  
Nitrogen Deficiency ◽  
Chlorella Pyrenoidosa ◽  
High Light Intensity ◽  
High Light ◽  
Overflow Metabolism ◽  
High Co2 ◽  
Light Intensities ◽  
N Assimilation

1. The effect of nitrate reduction and assimilation on the CO2/O2 quotient of gas exchange has been used as an index of the relative rates of carbon and nitrogen assimilation in Chlorella pyrenoidosa. Changes in over-all metabolism induced by starvation, high light intensity, and nitrogen deficiency have been studied in comparison with the metabolism of cells growing at light-limiting intensities. 2. Starvation, which results in depletion of carbohydrate reserves, gives rise to a high CO2/O2 quotient (∼0.9) during photosynthesis and, therefore, a high C/N assimilation ratio. Starved cells apparently restore their normal C/N ratio before becoming growing cells. 3. Under photosynthesis-saturating light intensities cells show the high CO2/O2 quotient (0.9) indicative of a high C/N assimilation ratio. Return to low light intensities is followed by the abnormally low CO2/O2 quotient (∼0.4) of a low C/N assimilation ratio. High light intensity apparently gives rise to a condition of a limiting rate of nitrogen assimilation and to an overflow metabolism analogous to that found in other microorganisms. 4. Nitrogen deficiency leads to a completely carbohydrate metabolism in short time experiments and makes still more pronounced the effects characteristic of high light intensity alone. 5. Considerations of nutritional economy sustain the experimental evidence in establishing the metabolism of cells growing under light-limiting intensities as the normal or reference metabolic condition in Chlorella.

Factors affecting growith and distribution of kauri (Agathis australis Salisb.) I. Effect of light on the establishment of Kaura and of Phyllocladus trichomanoides D.Don

1959 ◽  
Vol 7 (3) ◽  
pp. 252 ◽  
Author(s):  
RL Bieleski
Keyword(s):  
Light Intensity ◽  
Frequency Distribution ◽  
High Light Intensity ◽  
High Light ◽  
Low Light ◽  
Factors Affecting ◽  
Light Intensities ◽  
Seedling Distribution ◽  
Conifer Seedling ◽  
Effect Of Light

A method for determining the effect of light on seedling distribution in the field is described. It can be applied when seedling frequencies are as low as 1/m2. The frequency distribution of light intensities occupied by seedlings in a quadrat is compared with the frequency distribution of light intensities measured on a grid in the quadrat. This method was used to study the effect of light intensity on the establishment of two New Zealand gymnosperms, kauri (Agathis australis) and Phyllocladus trichomanoides, in the nursery community, a semimature Leptospermum scoparium – L. ericoides associes. Kauri and Phyllocladus did not occur at light intensities below 0.015 and 0.018 full daylight respectively. This limitation appeared to be due to the low light intensity presumably limiting photosynthesis. Kauri, but not Phyllocladus, also showed a high light intensity limit, at 0.30 full daylight, above which seedlings did not establish. Reasons are given for considering this as an indirect effect, probably through related solar heating affecting soil temperature or moisture. The optimal light intensity for kauri and Phyllocladus seedling establishment was close to the modal light intensity under the Leptospermum community: Leptospermum spp. were incapable of regenerating under their own cover. These two reasons appear to explain the suitability of the Leptospermum community as a nurse crop for the two conifer seedling species.

Selection for light preference during ovipositing in Drosophila pseudoobscura

1983 ◽  
Vol 25 (5) ◽  
pp. 446-449 ◽  
Author(s):  
Marvin B. Seiger ◽  
Amelia Broach Sanner
Keyword(s):  
Light Intensity ◽  
Genetic Variability ◽  
High Light Intensity ◽  
High Light ◽  
Drosophila Pseudoobscura ◽  
Low Light ◽  
Original Population ◽  
Low Light Intensity ◽  
Light Intensities ◽  
Light Preference

Selection was carried out on a population of Drosophila pseudoobscura to obtain lines preferring high-light intensity or low-light intensity during oviposition. This species is generally characterized as preferring low-light intensities. It was possible to select for increased preference for high-light intensity, but not for low-light intensity during oviposition. However, additive genetic variability exists in preferences for both high- and low-light intensities. The original population was probably operating at a photonegative extreme for oviposition, yet maintained enough genetic variability to permit selection toward a photopositive preference.

scholarly journals ACCUMULATION AND METABOLISM OF CARBOHYDRATES IN MARIGOLD SEEDLINGS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 648d-648
Author(s):  
Jack W. Buxton ◽  
Donna Switzer ◽  
Guoqiang Hou
Keyword(s):  
Light Intensity ◽  
Reducing Sugars ◽  
Starch Content ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Night Temperature ◽  
Temperature Regimes ◽  
Lower Light ◽  
Lower Light Intensity

Marigold seedlings, 3 weeks old, were grown in natural light growth chambers at 3 day/night temperature regimes, 8°N/16°D, 13°N/20°D and 18°N/24°D, in a factorial combination with ambient and 1000-1500 ppm CO2. Seedlings were harvested at regular intervals during a 24 hr period and were analyzed for soluble sugars (reducing sugars and sucrose) and starch. Neither temperature nor CO2 concentration affected the accumulation of soluble sugars or starch during the day or night. The soluble sugar concentration ranged from 3% of dry weight at sunrise to 6% at mid-day; the concentration changed little during the night. Light intensity was different during replications of the experiment. Increased light intensity appeared to cause a slight increase in the soluble sugars maintained by the seedling during the day. Accumulated starch increased 6% to 8% from sunrise to late afternoon. Preliminary results indicate that light intensity greatly affected the concentration of starch. On the higher light intensity day, starch accumulated to a maximum of 18% of dry weight; whereas on the lower light intensity day the maximum concentration was 10%. During the night following the lower light intensity day, the starch concentration decreased to approximately 3% by the end of the night; following a brighter day the starch content was 13% at the end of the night.

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