scholarly journals The Fluorescent Measurement in D. Magna Feeding Suppression Bioassay during the Pre-exposure in Potassium Dichromate for 1, 2, 3, 4 and 5 Hours

2020 ◽  
Vol 2 (10) ◽  
pp. 1-4
Author(s):  
Kamaya Minori * ◽  
◽  
Ginatullina Elena* ◽  
Yamagata Kohei ◽  
◽  
...  
Keyword(s):  
Exposure Time ◽  
Fluorescence Intensity ◽  
Feeding Rate ◽  
Potassium Dichromate ◽  
Feeding Activity ◽  
Feeding Suppression

The present study focused on observation of effect of potassium dichromate as standard toxicant on feeding activity of D. magna. Isolated feeding suppression was measured as fluorescence intensity of ingested microbeads by daphnids and expressed as its feeding rate (EC50FI). We calculated the sub-lethal feeding suppression endpoints for 1, 2, 3, 4 and 5 hours exposure in potassium dichromate and compared these values with EC50 concentration of immobilization test of D. magna. The most close to immobilization (EC50)result was obtained as for 4 as well for 5 hours exposure time; however 4 hs exposure was chosen as more adequate exposure time for our design of feeding suppression bioassay.

Seasonal Changes in Feeding Rate in Balanus Balanoides

1970 ◽  
Vol 50 (1) ◽  
pp. 223-240 ◽  
Author(s):  
D. A. Ritz ◽  
D. J. Crisp
Keyword(s):  
Cold Tolerance ◽  
Breeding Season ◽  
Seasonal Changes ◽  
Feeding Rate ◽  
Feeding Activity ◽  
Regular Sequence ◽  
Physiological Changes ◽  
High Degree ◽  
Balanus Balanoides

In Balanus balanoides (L.) several abrupt physiological changes occur after the breeding season in November. They include loss of gonads and associated organs, the acquisition of a high degree of cold tolerance (Crisp & Ritz, 1967), interruption of the regular sequence of moulting cycles (Crisp & Patel, 1960) and the reduction in feeding activity.

Simultaneous multitasking behaviour affects feeding efforts of male fiddler crabs (Brachyura, Ocypodidae)

Crustaceana ◽  
2018 ◽  
Vol 91 (5) ◽  
pp. 591-597
Author(s):  
Fahmida Wazed Tina ◽  
Mullica Jaroensutasinee ◽  
Krisanadej Jaroensutasinee
Keyword(s):  
Feeding Rate ◽  
Feeding Activity ◽  
Fiddler Crabs ◽  
Output Quantity

Abstract In animals, both monotasking and multitasking behaviours are observed. Multitasking behaviour helps to increase output quantity, but one activity may distract attention from another, and activities may interact negatively as they compete for the same amount of time available. To test this, we video recorded 23 Austruca bengali (Crane, 1975) males who were ‘feeding only’ (monotasking) and 24 males who were ‘feeding and courting (waving major claws) females’ simultaneously (multitasking). We measured the feeding and waving rates for ‘feeding and waving’ males, and the feeding rate for ‘feeding only’ males. We found that the feeding rate of ‘feeding only’ males was higher, but they reduced their feeding rate when they shared the time for feeding and courting. Moreover, feeding rate was negatively correlated with waving rate for ‘feeding and waving’ males. Our results indicate that courting activity distracted attention from feeding activity, and that activities interacted negatively with each other.

scholarly journals Genetic analysis of larval feeding behaviour in Drosophila melanogaster

1974 ◽  
Vol 24 (2) ◽  
pp. 163-173 ◽  
Author(s):  
David Sewell ◽  
Barrie Burnet ◽  
Kevin Connolly
Keyword(s):  
Drosophila Melanogaster ◽  
Feeding Rate ◽  
Feeding Activity ◽  
Gene Interaction ◽  
Physiological Age ◽  
Correlated Response ◽  
Larval Feeding ◽  
Selected Lines ◽  
Allelic Gene ◽  
Larva Feeding

SUMMARYThe larvae of Drosophila melanogaster feed continuously during their period of development. The rate of feeding activity, measured as the number of cephalopharyngeal retractions per minute, varies with the physiological age of the larva. Feeding rate responded readily to directional selection to give rise to non-overlapping populations with fast and slow feeding larvae, respectively. Realized heritabilities for the character from different selected lines varied between 11 and 21%. Crosses between the selected populations show significant dominance for fast feeding rate and appreciable non-allelic gene interaction. Larvae of the slow feeding populations showed a correlated reduction in locomotor activity but fast feeding larvae do not move about significantly faster than the unselected controls. Asymmetry of the correlated response to selection, it is argued, is due to selection in the slow feeding populations of alleles with a secondary effect in both behaviours.

Review: Feeding behaviour of dairy cattle: Meaures and applications

2010 ◽  
Vol 90 (3) ◽  
pp. 303-309 ◽  
Author(s):  
M A.G. von Keyserlingk ◽  
D M Weary
Keyword(s):  
Dairy Cattle ◽  
Feed Intake ◽  
Feeding Behaviour ◽  
Feeding Rate ◽  
Post Partum ◽  
Feeding Activity ◽  
Daily Intake ◽  
Empirical Work ◽  
Cattle Feeding ◽  
Intensively Managed

There is growing scientific interest in feeding behaviour of dairy cattle, in part because dairy nutritionists are now becoming interested in how changes in feed intake are mediated by changes in behaviour and, in part, because changes in feeding behaviour are increasingly recognized as useful indicator of cow health. In this review we describe key methodological approaches to the study of feeding behaviour in dairy cattle. We also review empirical work addressing how changes in management and housing can affect this behaviour. We show how cows divide their daily intake into several discrete feeding events made up of a number of visits or “meals” that are separated by longer periods with little feeding activity. Feeding behaviour can be described using several measures, including the number and duration of meals, as well as intake and feeding rate. Feeding behaviour within a group of intensively managed cows is often highly synchronized, similar to that seen in extensively housed cattle, with delivery of fresh feed appearing to be the primary factor stimulating feeding by housed dairy cows. Competition at the feed bunk can affect feeding behaviour, increasing the feeding rate and reducing intake, especially for subordinate animals. We also review empirical work showing that feed intake, feeding times, and feeding rate are altered when cows are ill. Feeding behaviour changes in the days before calving, and these changes are greatest among cows at greatest risk of succumbing to disease in the early post partum period. These results suggest that monitoring changes in feeding behaviour may be useful in early detection and prevention of disease in transition cows.Key words: Dairy cattle, feeding behaviour, management, health

Variable Gut Residence Time: Problems in Inferring Feeding Rate from Stomach Fullness of a Mysid Crustacean

1984 ◽  
Vol 41 (9) ◽  
pp. 1287-1293 ◽  
Author(s):  
Paul A. Murtaugh
Keyword(s):  
Residence Time ◽  
Feeding Rate ◽  
Feeding Activity ◽  
Ingestion Rate ◽  
Continuous Exposure ◽  
Stomach Fullness ◽  
Evacuation Rate ◽  
Passage Times

The gut residence time of the mysid crustacean Neomysis mercedis is extremely variable and is negatively correlated with ingestion rate. In two experiments in which mysids were fed copepod meals followed by continuous exposure to Daphnia, passage times varied from less than 1 to more than 13 h, and there were significant negative correlations of both copepod and daphnid passage times with the average feeding rate on Daphnia. In a third experiment starved mysids retained significant amounts of material in the stomach for more than 3 d. This dependence of evacuation rate on feeding activity may invalidate attempts to infer absolute or relative ingestion rate from the stomach fullness of field-caught animals.

scholarly journals PENGARUH INTENSITAS CAHAYA TERHADAP PEMANGSAAN LARVA IKAN CLOWN (Amphiprion ocellaris) PADA AWAL PEMELIHARAAN

2016 ◽  
Vol 2 (3) ◽  
pp. 359
Author(s):  
Ketut Maha Setiawati ◽  
Philip Teguh Imanto ◽  
Daniar Kusumawati
Keyword(s):  
Light Intensity ◽  
Feeding Rate ◽  
Fish Larvae ◽  
Feeding Activity ◽  
Early Morning ◽  
Color Spectrum ◽  
Role Of Light

Penelitian pemangsaan larva ikan clown (Amphiprion ocellaris) pada awal pemeliharaan dan umur sepuluh hari dilakukan menggunakan tangki serat kaca (fiberglass) volume 200 L. Pakan zooplankton rotifera disediakan sejak telur menetas dengan kepadatan 5 ind./mL. Mulai D-8 zooplankton nauplii Artemia ditambahkan dengan kepadatan 1.700 ind./tangki. Pengambilan sampel dilakukan pada umur 1 hari dan sepuluh hari, masing-masing 10 ekor larva/sampling dengan interval waktu 3 jam. Larva diukur kemudian dibedah dan dianalisis jumlah pemangsaaannya dengan bantuan stereoscopic microscope. Hasil analisis menunjukkan peranan intensitas cahaya dalam aktivitas pemangsaannya sebesar 5 individu rotifera dengan intensitas cahaya 70 lux pada pagi hari, sedang pemangsaan tertinggi terjadi pada pukul 13.00—16.00 dengan pemangsaan 57 individu rotifera pada saat intensitas cahaya menurun. Spektrum warna cahaya diduga lebih berperanan pada kemampuan maksimal memangsa dari larva ikan laut.Observation on feeding activity of clown fish (A. ocellaris) larvae have been conducted in 200 L. fiberglass tanks. Zooplankton rotifers were used as initial feed at a rate of 5 ind./mL. After eight days culture, nauplii Artemia were added at rate of 1,700 ind./ tank. Sampling was done on D-1 and D-10 at 10 individuals even sampling at three hours interval. The larvae were measured under a stereoscopic microscope, examining the digestion apparatus to count number of rotifers and nauplii Artemia as well. The result showed that the role of light intensity in feeding: 5 individual rotifer at 70 lux in early morning for D-1 larvae. The highest feeding occurred at 13.00-16.00 in the after noon at 57 individual rotifer when light intensity decreased. Color spectrum of light were predicted having more roles related to the maximum feeding rate  of clown fish larvae.

Preparation of Thin Cadmium Telluride Samples for Electron Microscope Studies

1974 ◽  
Vol 32 ◽  
pp. 548-549
Author(s):  
T. J. Magee ◽  
J. Peng ◽  
J. Bean
Keyword(s):  
Electron Microscope ◽  
Sulfuric Acid ◽  
Solid State ◽  
Sample Preparation ◽  
Cadmium Telluride ◽  
Potassium Dichromate ◽  
Optical Components ◽  
The Past ◽  
Solid State Devices

Cadmium telluride has become increasingly important in a number of technological applications, particularly in the area of laser-optical components and solid state devices, Microstructural characterizations of the material have in the past been somewhat limited because of the lack of suitable sample preparation and thinning techniques. Utilizing a modified jet thinning apparatus and a potassium dichromate-sulfuric acid thinning solution, a procedure has now been developed for obtaining thin contamination-free samples for TEM examination.

Progress In The Practical Application Of Automated Image Analysis To Tem Negatives

1977 ◽  
Vol 35 ◽  
pp. 214-217
Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly
Keyword(s):  
Image Analysis ◽  
Image Quality ◽  
Exposure Time ◽  
Image Contrast ◽  
Automated Image Analysis ◽  
Practical Application ◽  
Factors Affecting ◽  
High Image Quality ◽  
Qualitative Evidence ◽  
Comprehensive Study

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.

Structure images of Si, Ge and Mos2 crystals and some application to radiation damage studies

1978 ◽  
Vol 36 (1) ◽  
pp. 292-293 ◽  
Author(s):  
K. Izui ◽  
T. Nishida ◽  
S. Furuno ◽  
H. Otsu ◽  
S. Kuwabara
Keyword(s):  
Radiation Damage ◽  
Exposure Time ◽  
Gaussian Distribution ◽  
Intensity Distribution ◽  
Chromatic Aberration ◽  
Magnetic Lens

Recently we have observed the structure images of silicon in the (110), (111) and (100) projection respectively, and then examined the optimum defocus and thickness ranges for the formation of such images on the basis of calculations of image contrasts using the n-slice theory. The present paper reports the effects of a chromatic aberration and a slight misorientation on the images, and also presents some applications of structure images of Si, Ge and MoS2 to the radiation damage studies.(1) Effect of a chromatic aberration and slight misorientation: There is an inevitable fluctuation in the amount of defocus due to a chromatic aberration originating from the fluctuations both in the energies of electrons and in the magnetic lens current. The actual image is a results of superposition of those fluctuated images during the exposure time. Assuming the Gaussian distribution for defocus, Δf around the optimum defocus value Δf0, the intensity distribution, I(x,y) in the image formed by this fluctuation is given by

Partial characterization and post-feeding activity of midgut aminopeptidase in the human body louse,Pediculus humanus humanus

1998 ◽  
Vol 23 (4) ◽  
pp. 382-387 ◽  
Author(s):  
James O. Ochanda ◽  
Eva A. C. Oduor ◽  
Rachel Galun ◽  
Mabel O. Imbuga ◽  
Kosta Y. Mumcuoglu
Keyword(s):  
Human Body ◽  
Feeding Activity ◽  
Partial Characterization ◽  
Body Louse ◽  
Pediculus Humanus ◽  
Post Feeding ◽  
Human Body Louse
Sign in / Sign up

Export Citation Format

Share Document