Experimental studies on the development of Lernaeocera branchialis (Copepoda: Pennellidae): population processes from egg production to maturation on the flatfish host

Hydrobiologia ◽  
1988 ◽  
Vol 167-168 (1) ◽  
pp. 579-586 ◽  
Author(s):  
P. J. Whitfield ◽  
M. W. Pilcher ◽  
H. J. Grant ◽  
J. Riley
Keyword(s):  
Egg Production ◽  
Experimental Studies ◽  
Population Processes

THE OCCURRENCE AND DISTRIBUTION OF SALMONELLA TYPES IN FOWL: II. STUDIES OF ARTIFICIAL S. BAREILLY AND S. ORANIENBURG INFECTIONS IN HENS

1947 ◽  
Vol 25f (6) ◽  
pp. 316-325
Author(s):  
F. E. Chase
Keyword(s):  
Egg Production ◽  
Intestinal Tract ◽  
Experimental Studies ◽  
Similar Nature ◽  
Development Of Resistance ◽  
Oral Inoculation

Experimental studies carried out on a limited number of hens infected orally with S. bareilly indicated that occasionally such hens may lay contaminated eggs. Using the estimated numbers of S. bareilly in the feces as the criterion of infection, considerable variation in susceptibility was evident, the carrier period ranging from 5 to 40 days. The organisms were recovered from the intestinal tract and in one instance from the spleen. The apparent development of resistance to repeated oral inoculation was demonstrated. Experiments of a similar nature were made with hens infected orally with S. oranienburg. No contaminated eggs were found, though in this case low egg production resulting from some of the hens moulting reduces the significance of this finding. Fecal counts were lower than those obtained from the S. bareilly infected hens. S. bonariensis was isolated from the feces of two hens during this experiment.

scholarly journals Efficacy of a novel topical combination of esafoxolaner, eprinomectin and praziquantel against adult cat flea Ctenocephalides felis and flea egg production in cats

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 21 ◽  
Author(s):  
Eric Tielemans ◽  
Prescillia Buellet ◽  
David Young ◽  
Alta Viljoen ◽  
Julian Liebenberg ◽  
...  
Keyword(s):  
Egg Production ◽  
Experimental Studies ◽  
Ctenocephalides Felis ◽  
Control Group ◽  
Placebo Control ◽  
Immature Stages ◽  
The Novel ◽  
Cat Flea ◽  
Larval Hatching ◽  
Adult Cat

Esafoxolaner, a purified enantiomer of afoxolaner with insecticidal and acaricidal properties, is combined with eprinomectin and praziquantel in NexGard® Combo, a novel topical endectoparasiticide formulation for cats. The efficacy of this novel formulation against adult and immature stages of Ctenocephalides felis fleas was tested in four experimental studies. Two studies were designed to test adulticide efficacy, one to test inhibition of immature stages, and one to test both adulticide efficacy and inhibition of immature stages. In each study, cats were randomly allocated to a placebo control group or to a novel formulation group treated once at the minimum recommended dose. Cats were experimentally infested weekly for one to two months with unfed C. felis originating from North America or Europe. For adulticide efficacy evaluations, live fleas were counted 24 h after treatment and after subsequent weekly infestations. For immature stages, flea eggs were collected and counted weekly for evaluation of egg production inhibition and incubated for larval hatching evaluation. In the three studies testing adult fleas, curative efficacies, 24 h after treatment, were 92.1%, 98.3% and 99.7%; preventive weekly efficacies, 24 h after weekly infestations, remained higher than 95.5% for at least one month. In the two studies testing immature stages, egg production and larval hatching was significantly reduced for at least one month. These studies provide robust evidence of efficacy of the novel formulation against experimental adult flea infestations and for the prevention of environmental contamination by immature flea stages, for at least one month.

scholarly journals Продуктивність та забійні якості перепелів при використанні різних джерел метоніну в раціонах

2017 ◽  
Vol 7 (2) ◽  
pp. 24-30
Author(s):  
M. Sychov ◽  
A. Chsherbina
Keyword(s):  
Egg Production ◽  
Experimental Studies ◽  
Feed Additives ◽  
Egg Laying ◽  
Carcass Quality ◽  
Feed Conversion ◽  
Daily Growth ◽  
National University ◽  
The Impact ◽  
Different Sources

<p>The authors have investigated the effect of different sources of metonin in the diets of quails on their productivity and carcass quality. Experimental studies were carried out with Pharaoh quails in Problematic Research Laboratory of Feed Additives in the National University of Life and Environmental Sciences of Ukraine. The experiment was carried out by method of groups-analogues. Compound feed were fed in dry crumbled form; young birds were fed in a group. The daily amount of compound feed was divided in two parts – morning and evening rations with different sources of metonin (<em>DL-</em> metonin<em>,</em> <em>L-</em>metonin <em>and МНА)</em>).</p><p>We have found that compound feed with the <em>L-</em>metonin contributes to live body weight increase by 5.3% or 13 g, average daily growth by 5.9 % or 0.37 g, reduces feed conversion by 2.1%, increases the mass of not gutted carcass, semi gutted carcass and gutted carcass of 12.5 (6.2%), 12.5 (6.2%), and 10.5 g (6.4%); increases the mass of pectoral muscles and muscles of the pelvic limbs by 7.37 and 6.49 g (18.2% and 24.5%) and mass of liver by 0.94 g. Use of diets with<em> </em>MНA and DL-methionine did not significantly effect the productivity and carcass quality, whereas entry to the diet of MNA increased feed conversion by 5.4%. During the study period the safety of livestock which was fed with different sources of metonin ranged from 93 to 96%.</p><p>We believed the further research are needed to examine the impact of different sources of metonin on the egg production of egg-laying quails, morphological and chemical composition of eggs and their hatching quality.</p>

scholarly journals Dynamics of the O. felineus Infestation Intensity and Egg Production in Carcinogenesis and Partial Hepatectomy in the Setting of Superinvasive Opisthorchiasis

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Vitaly G. Bychkov ◽  
Ludmila F. Kalyonova ◽  
Elena D. Khadieva ◽  
Semen D. Lazarev ◽  
Ilgiz R. Lukmanov ◽  
...  
Keyword(s):  
Partial Hepatectomy ◽  
Ecological Niche ◽  
Egg Production ◽  
Tumour Growth ◽  
Experimental Studies ◽  
Infestation Intensity ◽  
Intensity Of Invasion

Clinical and experimental studies have shown that opisthorchii tend to evade tumour growth foci to colonize more distant areas of the liver. When modelling tumours with various carcinogens in the setting of superinvasive opisthorchiasis, the intensity of invasion is reduced both before the formation of neoplasms (>120 days) and after the development of tumours of various histogeneses (liver, pancreas, and stomach) (>240 days). Egg production was observed to increase with the decrease in the number of parasites in the liver. The smallest changes in the infestation intensity indicators and egg production were observed in the experimental stomach tumours (p>0.05). A partial hepatectomy in the setting of opisthorchiasis did not affect the number of parasites in the ecological niche (liver) or the production of eggs by the helminth. With the deterioration of the vegetation state, parasite clumps of opisthorchii increase egg production under the conditions of distress.

3-D reconstruction and analysis of mammalian mitotic spindle structure

1992 ◽  
Vol 50 (1) ◽  
pp. 578-579
Author(s):  
Kent McDonald ◽  
David Mastronarde ◽  
Rubai Ding ◽  
Eileen O'Toole ◽  
J. Richard McIntosh
Keyword(s):  
Cross Sections ◽  
Mitotic Spindle ◽  
Experimental Studies ◽  
Video Camera ◽  
Three Dimensions ◽  
Mitotic Spindles ◽  
Black And White ◽  
Reconstruction Methods ◽  
Spindle Structure ◽  
Tissue Culture Line

Mammalian spindles are generally large and may contain over a thousand microtubules (MTs). For this reason they are difficult to reconstruct in three dimensions and many researchers have chosen to study the smaller and simpler spindles of lower eukaryotes. Nevertheless, the mammalian spindle is used for many experimental studies and it would be useful to know its detailed structure.We have been using serial cross sections and computer reconstruction methods to analyze MT distributions in mitotic spindles of PtK cells, a mammalian tissue culture line. Images from EM negatives are digtized on a light box by a Dage MTI video camera containing a black and white Saticon tube. The signal is digitized by a Parallax 1280 graphics device in a MicroVax III computer. Microtubules are digitized at a magnification such that each is 10-12 pixels in diameter.

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