Light intensity and the oestrous cycle in albino and normally pigmented mice

1993 ◽  
Vol 27 (4) ◽  
pp. 385-390 ◽  
Author(s):  
Harry Donnelly ◽  
Palle Saibaba
Keyword(s):  
Light Intensity ◽  
Laboratory Animal ◽  
Oestrous Cycle ◽  
Lower Intensity ◽  
Albino Mice ◽  
The Difference

The effects of light intensity (15-20 lux & 220-290 lux) on the oestrous cycle of albino and normally pigmented mice were examined. The oestrous cycle of both types of mice was shorter at the lower intensity but the difference was significant only with the black mice. The proportion of albino mice from which embryos were recovered was significantly smaller than the proportion of black mice at 15-20 lux but not at 220-290 lux. No significant differences due to strain or light intensity were found in the number of embryos recovered. We conclude that pigmented mice respond in the same way as albino mice to changes in light intensity within the range normally found in laboratory animal accommodation. That is, increased light intensity prolongs the oestrous cycle and the period of vaginal cornification.

scholarly journals Adaptive-illumination STED nanoscopy

2017 ◽  
Vol 114 (37) ◽  
pp. 9797-9802 ◽  
Author(s):  
Jörn Heine ◽  
Matthias Reuss ◽  
Benjamin Harke ◽  
Elisa D’Este ◽  
Steffen J. Sahl ◽  
...  
Keyword(s):  
Light Intensity ◽  
Biological Imaging ◽  
The State ◽  
Lower Intensity ◽  
2D And 3D ◽  
Imaging Conditions ◽  
State Difference

The concepts called STED/RESOLFT superresolve features by a light-driven transfer of closely packed molecules between two different states, typically a nonfluorescent “off” state and a fluorescent “on” state at well-defined coordinates on subdiffraction scales. For this, the applied light intensity must be sufficient to guarantee the state difference for molecules spaced at the resolution sought. Relatively high intensities have therefore been applied throughout the imaging to obtain the highest resolutions. At regions where features are far enough apart that molecules could be separated with lower intensity, the excess intensity just adds to photobleaching. Here, we introduce DyMIN (standing for Dynamic Intensity Minimum) scanning, generalizing and expanding on earlier concepts of RESCue and MINFIELD to reduce sample exposure. The principle of DyMIN is that it only uses as much on/off-switching light as needed to image at the desired resolution. Fluorescence can be recorded at those positions where fluorophores are found within a subresolution neighborhood. By tuning the intensity (and thus resolution) during the acquisition of each pixel/voxel, we match the size of this neighborhood to the structures being imaged. DyMIN is shown to lower the dose of STED light on the scanned region up to ∼20-fold under common biological imaging conditions, and >100-fold for sparser 2D and 3D samples. The bleaching reduction can be converted into accordingly brighter images at <30-nm resolution.

scholarly journals Comparative study on the localization of adult Schistosoma mansoni worms in albino mice anesthetized with pentobarbital sodium, ether or chlorophorm

1993 ◽  
Vol 35 (4) ◽  
pp. 323-326 ◽  
Author(s):  
José Roberto Machado e Silva ◽  
Maria Adriana Dias de Lima ◽  
Rosângela Rodrigues e Silva ◽  
Arnaldo Maldonado Jr. ◽  
Octávio Augusto França Presgrave ◽  
...  
Keyword(s):  
Portal Vein ◽  
Comparative Study ◽  
Schistosoma Mansoni ◽  
Control Group ◽  
Pentobarbital Sodium ◽  
Mesenteric Veins ◽  
Anesthetic Drugs ◽  
Albino Mice ◽  
The Difference

The effect of anesthetic drugs on the localization of adult worms in albino mice was compared. The animals with 56 days of infection were anesthetized with pentobarbital sodium, ether or chlorophorm. Perfusion was carried out immediately after, recovering the worms and classifying them in relation to their localization on the liver or portal vein and the mesenteric veins. Our results showed that pentobarbital sodium produced a greater displacement of the worms to the liver (89%) than ether (76%) and chlorophorm (34%) did, when compared to the control group (22%). The difference between pentobarbital sodium and ether was significant (p < 0.05). We suggest that anesthetic drugs may not be used in studies on the distribution of adult worms in several hosts.

scholarly journals PENGARUH INTENSITAS CAHAYA TERHADAP KETERTARIKAN GEROMBOLAN IKAN PELAGIS KECIL PADA MINI PURSE SEINE DI PERAIRAN PEMALANG JAWA TENGAH

2017 ◽  
Vol 13 (2) ◽  
pp. 125
Author(s):  
Erfind Nurdin ◽  
Mohammad Natsir ◽  
Hufiadi Hufiadi
Keyword(s):  
Light Intensity ◽  
Significant Influence ◽  
High Intensity ◽  
Purse Seine ◽  
North Coast ◽  
Fish School ◽  
The Third ◽  
Small Intensity ◽  
The Difference ◽  
Fishing Practices

Penggunaan intensitas cahaya pada unit penangkapan light fishing cenderung meningkat. Hal ini, didasari atas persepsi bahwa intensitas cahaya yang tinggi akan meningkatkan hasil tangkapan. Fenomena ini dijadikan suatu penelitian yang dilakukan selama 3 minggu pada bulan September 2004 di perairan Pemalang Jawa Tengah. Alat tangkap pukat cincin mini (mini purse seine) di pantai utara Jawa pada operasi penangkapan selain menggunakan rumpon juga mengggunakan cahaya sebagai alat bantu penangkapan. Pengukuran nilai intensitas lampu dilakukan dengan meggunakan LI COR 250 quantum meter (μmol sɹ mɲ) pada jumlah lampu yang berbeda, dan digunakan pula akustik EY 500 untuk memperoleh data sebaran dan gerombolan ikan yang berada dalam pengaruh cahaya lampu. Pada deteksi awal (A) ikan cenderung mengelompok pada lahan intensitas tinggi, deteksi ke 2 (B) pengelompokkan mulai terkonsentrasi dekat kapal, deteksi ke-3 (C) pengelompokkan ikan bertambah banyak, dan deteksi ke-4 (D) kelompok ikan berada pada lahan yang sangat memungkinkan untuk ditangkap. Dari hasil penelitian diperoleh laju tangkap (catch rate) 125,7 kg per tawur. Perbedaan jumlah lampu yang sedikit tidak menunjukkan pengaruh yang terlalu besar terhadap hasil tangkapan. The influence of light intensity to the light fishing practices commonly tends to increase. Fishermen believe that with the higher intensity of light the bigger catch they have. This phenomenon stimulated us to a research that during was done three weeks on September 2004 in Pemalang West Java. Mini purse seine is conduct at north coast of Java use payaos and light artificial for fish attractive. LI COR 250 quantum metre (μmol sɹ mɲ) was used for light intencity at different lamps amount and EY 500 acoustic to obtain the data of fish school in influence of lamp light. At the first detecting (A) fish school was concentrated in high intensity area, the second detecting (B) the concentration was closer to the ship, the third detecting (C) fish school increased, and the forth detecting (D) fish school was consentrated in catchable area. The results show that the cath rate was 125.7 kg per setting. The difference of lamps amount with a small intensity did not show significant influence to the catch haul.

Change of Phototropic and Geotropic Signs in Daphnia Induced by Changes of Light Intensity

1930 ◽  
Vol 7 (2) ◽  
pp. 109-131 ◽  
Author(s):  
G. L. CLARKE
Keyword(s):  
Light Intensity ◽  
Latent Period ◽  
Daphnia Pulex ◽  
Great Majority ◽  
Absolute Intensity ◽  
Rate Of Change ◽  
Intensity Change ◽  
The Difference ◽  
The Individual ◽  
Secondary Signs

1. A method is described for studying the responses of Daphnia to changes of light intensity with special attention to the behaviour of the individual and to the avoidance of "shock" effects. The types of apparatus used provide for rigid control of the temperature, for illumination from any direction, and for an adjustable rate of change of the light intensity by means of a chemical rheostat. 2. The great majority of Daphnia magna and Daphnia pulex were found to be primarily negatively phototropic and positively geotropic. That is, they always exhibited those tropistic signs under constant conditions of illumination. 3. A reduction of the light intensity causes a temporary reversal of the tropism signs. The secondary signs thus produced are positive phototropism and negative geotropism. 4. The presence of both phototropic and geotropic forces is proved by experiments in which illumination is (1) from one side, (2) from beneath, and (3) from two opposing sides or from above and below simultaneously. In these tests and in others in which very slow and very fast rates of dimming are used the phototropic and geotropic forces are resolved, antagonised, and neutralised in succession. The responses of the Daphnia indicate that there are two types of animals which exhibit exactly the same tropisms, but in one type phototropism is the stronger while in the other geotropism is the stronger. 5. In this material it was found that the temporary secondary tropistic signs persisted only a few minutes while the primary signs persisted for hours, although this effect was somewhat less marked in weak light or in darkness. 6. The difference between "time-change" and "place-change" of light in tensity is pointed out. Daphnia is stimulated by both types of change if the rate of change is sufficiently great. 7. That photosensitive animals are stimulated to respond to changes in the intensity of light only and are merely orientated by the direction of the light is shown in the work of previous, investigators as well as in this paper. The rigidity of this mechanism is indicated by experiments in which the light is graded in intensity at right angles to its direction and in which the light is rendered converging and diverging by a lens. 8. Evidence is given for believing that there is no "absolute optimum" light intensity for Daphnia but that a "relative optimum" exists which is the intensity to which the animals are adapted at the moment. 9. The interval between the inception of the reduction of the light intensity and the beginning of swimming movements in response is called the latent period. The faster the rate of dimming, the shorter is the duration of the latent period. A minimum, amount of intensity change is required to produce any response, at any speed, but beyond that the slower the rate of dimming, the greater is the amount of change required and hence the lower is the absolute intensity at which the response takes place. Ordinarily, the response is maximal in respect to both rate and magnitude. 10. Fatigue will interfere with experimentation unless guarded against. 11. Specimens of Daphinia with reversed primary signs gain temporary secondary signs following an increase of light intensity; otherwise they behave like the more usual forms. 12. The possibility that the processes of adaptation in Daphnia may account for the photic responses observed is discussed. Support for this theory is derived from the fact that it is possible to dim the light over a given range at such a slow rate that no response is produced.

scholarly journals Estimasi Produk Degradasi Ekstrak Kasar Pigmen Alga Merah Kappaphycus alvarezii (Doty) Doty Varian Merah, Coklat, dan Hijau: Telaah Perbedaan Spektrum Serapan

2012 ◽  
Vol 17 (1) ◽  
pp. 31
Author(s):  
Helly De Fretes ◽  
A.B. Susanto ◽  
Budi Prasetyo ◽  
Heriyanto Heriyanto ◽  
Tatas H.P. Brotosudarmo ◽  
...  
Keyword(s):  
Light Intensity ◽  
Absorption Spectra ◽  
Degradation Products ◽  
Kappaphycus Alvarezii ◽  
Red Alga ◽  
Before And After ◽  
Heating Treatment ◽  
Pigment Extract ◽  
The Difference ◽  
Difference Absorption

Penelitian ini bertujuan untuk mengestimasi produk degradasi pigmen ekstrak kasar alga merah Kappaphycus alvarezii (Doty) Doty varian merah, coklat dan hijau yang terbentuk selama perlakuan iradiasi dan pemanasan, melalui perbedaan spektrum serapannya. Ketiga varian diekstraksi menggunakan 100% metanol. Uji fotostabilitas ekstrak pigmen dilakukan dengan iradiasi menggunakan lampu Volpi intralux 4100 pada intensitas cahaya 39300 lux, 56700 lux dan 76400 lux.  Lama waktu penyinaran 0, 5, 10, 15, dan 20 menit. Sedangkan uji termostabilitas  dilakukan pada suhu 25 dan 90 ° C selama 0, 3, 6 24, dan 48 jam. Pola spektra diukur pada panjang gelombang 300-800 nm sebelum dan sesudah perlakuan dengan spektrofotometer UV-Tampak Shimadzu 1700. Data dianalisis dengan SPINA Versi 3, untuk memperoleh intensitas maksimum dan perbedaan spektra serapan. Hasil penelitian menunjukkan bahwa produk degradasi pigmen ekstrak kasar alga merah K. alvarezii dapat diidentifikasi melalui spektrum serapan dan hasil perbedaan spektra serapan. Isomer cis karotenoid, karotenoid tidak berwarna, dan feofitin a diestimasi sebagai produk degradasi yang terbentuk selama perlakuan iradiasi dengan intensitas cahaya 76400 lux dan perlakuan pemanasan pada suhu 90°C selama 48 jam. Penurunan intensitas warna larutan pigmen juga mengindikasikan terbentuknya produk degradasi selama perlakuan. Kata kunci: Kappaphycus alvarezii, perbedaan spektrum serapan, produk degradasi The aims of this study were to estimate the degradation products of crude pigment extracts from red, brown, and green varieties of red alga Kappaphycus alverezii (Doty) Doty that formed during irradiation and heating treatment from their difference absorption spectra. All three variants were extracted using 100% methanol. The photostability assay of crude pigment extracts was conducted by irradiating the crude pigment extracts with a day light lamp (Volpi, Intralux 4100) at 39300 lux, 56700 lux and 76400 lux light intensity during 0, 5, 10, 15, and 20 minutes treatment, whereas the thermostability assay was performed at 25 and 90 °C for 0, 3, 6 24, and 48 hours. The absorption spectra of the crude pigment extract before and after each treatment were monitored successively at 300-800 nm using MultiSpec 1501 UV-VIS spectrophotometer. Data were analyzed with spina Version 3, to obtain maximum intensity and the difference absorption spectra. The results showed that the  degradation products of crude pigment extracts from red alga K. alvarezii could be identified by absorption spectra and difference absorption spectra. Cis isomers carotenoids, colorless carotenoids, and feofitin-a were estimated as degradation product formed during the irradiation treatment with 76400 lux of light intensity and heating treatment at a temperature of 90 ° C for 48 hours. Decrease in the intensity of the color of pigment solution also indicates the formation of degradation products during treatment.Key words: Kappaphycus alvarezii, difference absorption spectra, degradation products

The Effect of Adding Lower Intensity Work on Perceived Aversiveness of Exercise

2000 ◽  
Vol 22 (2) ◽  
pp. 119-130 ◽  
Author(s):  
Britton W. Brewer ◽  
Tina M. Manos ◽  
Anne V. McDevitt ◽  
Allen E. Cornelius ◽  
Judy L. Van Raalte
Keyword(s):  
Perceived Exertion ◽  
Exercise Bout ◽  
Cycle Ergometer ◽  
Lower Intensity ◽  
Ratings Of Perceived Exertion ◽  
The Difference

Two studies tested the hypothesis that exertional trend influences perceived aversiveness of an exercise bout. In Study 1, participants (64 women and 26 men) read descriptions of 8 fictitious people’s ratings of perceived exertion during exercise sessions on a stationary bicycle, including a 15-min session with a pattern of increasing exertion and a 20-min session with a pattern of exertion identical to the 15-min session with the addition of a 5-min period of reduced exertion at the end. Despite a greater overall workload, the 20-min session was perceived as significantly less aversive than the 15-min session. In Study 2, participants (11 women and 9 men) completed 15- and 20-min sessions on a cycle ergometer with the same basic exertional patterns as in Study 1. Ratings of the aversiveness of the 2 sessions did not differ significantly, despite the difference in duration. Results demonstrate that adding a period of reduced exertion attenuates the perceived aversiveness of a bout of exercise.

Miniature ponies: 1. Follicular, luteal and endometrial dynamics during the oestrous cycle

2008 ◽  
Vol 20 (3) ◽  
pp. 376 ◽  
Author(s):  
E. L. Gastal ◽  
A. P. Neves ◽  
R. C. Mattos ◽  
B. P. L. Petrucci ◽  
M. O. Gastal ◽  
...  
Keyword(s):  
Comparative Studies ◽  
Potential Model ◽  
Oestrous Cycle ◽  
Maximum Diameter ◽  
Preovulatory Follicle ◽  
The Difference ◽  
Follicular Dynamics

Follicular dynamics were studied during 12 interovulatory intervals (IOIs) and 36 preovulatory periods in Miniature mares. The percentage of IOIs with the following follicle events was: ovulatory wave with only one follicle ≥10 mm (55%), diameter deviation similar to previous reports in larger mares (25%) and minor waves emerging before or after the ovulatory wave (55%). Follicle data were compared among Miniature ponies, large ponies and Breton horses (n = 12 IOIs per breed). The IOI was longer (P < 0.001) in Miniature ponies (23.3 ± 0.9 days) and in large ponies (23.9 ± 0.5 days) than in Breton horses (20.3 ± 0.7 days). The Miniature ponies had fewer (P < 0.0001) growing follicles ≥10 mm per ovulatory wave (1.5 ± 0.3) and more (P < 0.0004) ovulatory waves (6/11) with only one follicle ≥10 mm than large ponies (9.8 ± 0.8 and 0/12) and horses (5.8 ± 0.9 and 0/12). Maximum diameter of the preovulatory follicle was smaller (P < 0.003) in the Miniature ponies (38.3 ± 0.7 mm) than in the horses (44.5 ± 1.4 mm), but the difference between breeds was slight (6%) compared with the difference in bodyweight (65%). Considering the small number of follicles per ovulatory wave, Miniature mares are a potential model for comparative studies in folliculogenesis within and among species.

ÉTUDE COMPARATIVE DES EFFETS SEXUELS DES ANDROGÉNES NATURELS

1963 ◽  
Vol 43 (1) ◽  
pp. 27-46 ◽  
Author(s):  
C. J. Meyer ◽  
Ch. Krähenbühl ◽  
P. A. Desaulles
Keyword(s):  
Oestrous Cycle ◽  
The Other ◽  
Ventral Prostate ◽  
Male Rat ◽  
Naturally Occurring ◽  
Marked Activity ◽  
The Difference ◽  
Hydroxy Progesterone ◽  
Androgenic Effect ◽  
Very High

ABSTRACT A study was made of the activities exerted by the following naturally occurring androgens on the male sexual receptors of the capon and of the castrated male rat, and also of their inhibitory action on the oestrous cycle and gonadotrophic functions in the rat: testosterone, androsterone, androstenedione, adrenosterone, 11β-hydroxy-androstenedione, dehydroepiandrosterone, 17α-hydroxy-progesterone, and progesterone. When the effects of these androgens were investigated on a large number of receptors, the results revealed the differences in the spectrum of activity of each of the substances. Thus, for example, adrenosterone has an androgenic effect in castrated rats which is much greater than in the capon (corresponding to 50% and 5% respectively, of the activity of testosterone), whereas the difference in the androgenic effect exerted on the two species is much less marked in the case of androsterone and androstenedione. 17α-hydroxy-progesterone, on the other hand, displays marked activity on the capon's comb after local inunction, but has only a slight effect on the sexual adnexa of castrated rats. Of all the androgenic receptors investigated only the ventral prostate responds to treatment with progesterone. Of all the compounds included in this study, only 11β-hydroxy-androstenedione has an anabolic/androgenic ratio greater than testosterone, whereas with all the other compounds the ratio is less. Although the degree of inhibition exerted on the oestrous cycle is in all instances equivalent to less than 1/10 of that of testosterone, the anti-gonadotrophic activity as evidenced by experiments on parabiotic animals shows considerable variations from one steroid to the other. It is very high for androsterone and androstenedione (60% of that of testosterone), diminishes in the case of adrenosterone (20% of that of testosterone), and is even weaker in the case of 11β-hydroxy-androstenedione, dehydroepiandrosterone, 17α-hydroxy-progesterone, and progesterone, which has only 10% the activity of testosterone. The correlations between the different types of action and their possible implications are discussed.

scholarly journals Oestrous Frequency and Incidence of Pregnancy in Mice Housed Singly and in Groups at 4, 21, and 33°C

1972 ◽  
Vol 25 (4) ◽  
pp. 801 ◽  
Author(s):  
Pamela R Pennycuik
Keyword(s):  
Oestrous Cycle ◽  
Cycle Frequency ◽  
Tactile Contact ◽  
The Difference

Oestrous cycle frequency was measured in mice housed singly, in mice housed in groups, and in grouped females in olfactory and tactile contact with a male. The animals were kept at 4,21, or 33�0. When the mice were housed singly, all groups had between 2�2 and 3�5 cycles in the 16 days period of observation. The small differences between the groups were not significant. Grouping (15 mice per cage) caused a significant reduction in oestrous frequency at all three temperatures, but the differences between the temperature groups were not significant. Introduction of a caged male into the group of females had no effect on oestrous frequency at 4 and 21 �0. At 33�0 frequency increased and the difference between the temperature groups became significant. When the males were released into the cages of grouped females the incidence of pregnancy in the group at 33�0 was seven times greater than that at 4 or 21 �0.

scholarly journals PERANCANGAN ALAT UKUR INTENSITAS CAHAYA BERBASIS ARDUINO LEONARDO MENGGUNAKAN SENSOR LDR (Light Dependent Resistor)

2020 ◽  
Vol 16 (1) ◽  
pp. 1-13
Author(s):  
Simson Manik ◽  
Abdul Muis Muslimin ◽  
Aries A. Subgan
Keyword(s):  
Light Intensity ◽  
Comparative Data ◽  
Primary Data ◽  
Average Error ◽  
Measuring Device ◽  
Measuring Devices ◽  
Vertical Distance ◽  
Light Sensor ◽  
The Difference ◽  
Error Percentage

Lux meter is a device used to measure the intensity of light in an area. The purpose of this thesis is to design a light intensity measuring device using LDR components as a light sensor, comparing light intensity measuring devices made using LDR sensors and Arduino Leonardo based microcontrollers with standard tools. The data used in this study are primary data. The data obtained is then processed using MS. Excel. The type of light bulbs used are Philips CFL (Philips Essential) lamps, each lamp having a power of 5, 8, 11, 14, 18, 23, 27, 32, 35, and 50 watts with a luxmeter vertical distance of 1, 2 and 3 meters from the lamp. From the results of testing the tools and processing of comparative data between the Lux Meter Standard and the designed Lux ​​Meter obtained as follows: the vertical distance of the tool by 1 meter from the lamp produces an average error difference of 12,571 lx and the percentage of average errors the average is 8.77%, while for the vertical distance of the tool is 2 meters from the lamp the average error difference value is 2,358 lx and the average error percentage is 7.98%, and for the vertical tool distance is 3 meters from the lamp the difference in error value is an average of 0.92 lx and an average error percentage of 5.85%.

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