A mathematical model of fertilization failure and early embryonic mortality in sheep

1977 ◽  
Vol 89 (2) ◽  
pp. 309-317 ◽  
Author(s):  
P. A. Geisler ◽  
J. E. Newton ◽  
A. E. Mohan
Keyword(s):  
Mathematical Model ◽  
Reproductive Potential ◽  
Embryonic Mortality ◽  
Experimental Results ◽  
Fertilization Failure ◽  
Early Embryonic Mortality ◽  
Available Information

SummaryThe reproductive potential of a sheep system is much reduced by the failure of released ova to be fertilized and to survive to parturition. This paper looks at currently available information on fertilization failure and early embryonic deaths. Separate hypotheses are proposed for fertilization and for early embryonic mortality. For fertilization, the hypothesis is that a ewe that mates with a ram will end up with either all or none of her released ova fertilized. For embryonic mortality, the hypothesis is that the survival of a fertilized ovum depends only on how many ova were released with it and is independent of the survival or death of those released with it. A mathematical model is constructed on these hypotheses and its predictions are compared with published experimental results of other workers.

Assessment of reproductive wastage in sheep. 3. An investigation of a commercial sheep flock

1976 ◽  
Vol 16 (80) ◽  
pp. 344 ◽  
Author(s):  
BJ Restall ◽  
J Wilkins ◽  
R Kilgour ◽  
RN Tyrrell ◽  
H Hearnshaw
Keyword(s):  
New South ◽  
New South Wales ◽  
Fertilization Rate ◽  
Embryonic Mortality ◽  
Ovulation Rate ◽  
Fertilization Failure ◽  
Sheep Flock ◽  
South Wales ◽  
Early Embryonic Mortality ◽  
Made In

Infertility in a sheep flock in the Moree district of New South Wales was investigated during 1973. Detailed observations were made in two sub flocks and data were obtained in both maiden and adult ewes for proportion of ewes mating, ovulation rate, fertilization rate, and number of foetuses at 60 days of pregnancy. These estimates were used to apportion prenatal wastage to mating failure, fertilization failure or early embryonic mortality. Ovulation rate in the flock was high (1.27 maiden ewes, 1.73 adult ewes) and fertility low with 83 per cent of maiden ewes and 27 per cent of adult ewes not pregnant when examined by laparotomy 60 days after mating. In the adult ewes this infertility was accounted for by failure to mate (30 per cent of dry ewes) and early embryonic mortality (70 per cent of dry ewes). In the maiden ewes, failure to mate accounted for 34 per cent, embryonic mortality 52 per cent and failure of fertilization 14 per cent of the dry ewes. The problems of estimation and interpretation involved in this type of investigation are discussed.

Friction and Tribological Considerations for Nanometer Range Machining

2001 ◽  
Author(s):  
Som Chattopadhyay
Keyword(s):  
Mathematical Model ◽  
High Precision ◽  
Local Deformation ◽  
Experimental Results ◽  
Precision Machining ◽  
Complex Motion ◽  
Positioning Accuracy ◽  
Nanometer Range ◽  
Motion Characteristic ◽  
Low Speeds

Abstract Positioning accuracy within the range of nanometers is required for high precision machining applications. The implementation of such a range is difficult through the slides because of (a) irregular nature of friction at the slider-guideway interface, and (b) complex motion characteristic at very low speeds. The complexity arises due to the local deformation at the interface prior to breakaway, which is known as microdynamics. In this work prior experimental results exhibiting microdynamics have been appraised, and mathematical model developed to understand this behavior.

Design and Experimental Analysis of Novel Refractometer Based on Photoelectric Sensor Technology

2011 ◽  
Vol 383-390 ◽  
pp. 5211-5215
Author(s):  
Yin Lin Li ◽  
Zhong Hua Huang ◽  
Kai Bo Hu
Keyword(s):  
Mathematical Model ◽  
Experimental Analysis ◽  
Differential Method ◽  
Theoretical Solution ◽  
Experimental Results ◽  
Sensor Technology ◽  
Photoelectric Sensor ◽  
Better Than

A novel refractometer based on photoelectric sensor technology and differential method is proposed. Sensing principle and mathematical model are introduced; structure and key parameters of sensing probe are designed through detail calculation. Theoretical solution shows resolution reaches order of 10-5. Preliminary experiments verify the feasibility of the design, experimental results show stability error better than ±1.02×10-4, error caused by temperature is 6.65×10-6/°C.

An Improved Trace Method for Moving Target under Occlusion

2014 ◽  
Vol 672-674 ◽  
pp. 1931-1934
Author(s):  
Yu Bing Dong ◽  
Guang Liang Cheng ◽  
Ming Jing Li
Keyword(s):  
Mathematical Model ◽  
Target Tracking ◽  
Difficult Problem ◽  
Block Matching ◽  
Experimental Results ◽  
Polar Coordinates ◽  
Moving Target ◽  
Trajectory Prediction ◽  
Tracking Method

Occlusion is a difficult problem to be solved in the process of target tracking. In order to solve the problem of occlusion, a new tracking method combined with trajectory prediction and multi-block matching is presented and studied,and a mathematical model of trajectory prediction of moving target is established in polar coordinates and verified through some experiments. The experimental results show that the new tracking method can be better to trace and forecast the moving target under occlusion.

scholarly journals Modelling simultaneous removal of trichlorfon and glucose in a hybrid bioreactor containing magnetically immobilized biomass

1998 ◽  
Vol 38 (4-5) ◽  
pp. 179-186 ◽  
Author(s):  
Guang Hao Chen ◽  
Hiroaki Ozaki ◽  
Yutaka Terashima
Keyword(s):  
Mathematical Model ◽  
Carbon Source ◽  
Experimental Results ◽  
Simultaneous Removal ◽  
Industrial Wastewaters ◽  
Suspended Biomass ◽  
Immobilized Biomass

This paper focuses on a simultaneous removal of trichlorfon and glucose that was added as carbon source for degradation requirement of trichlorfon. A hybrid bioreactor, having both suspended and magnetically immobilized biomass, was used for investigating this removal of both substances. To evaluate the respective roles of these two types of biomass, a mathematical model was developed and also verified well with experimental results. It has been found that the suspended biomass plays a key role in removing both substances in the system. This is due to complete coexistence of both trichlorfon-degrading and glucose-removing bacteria completely in each type of the biomass. Such a system would be applicable to the treatment of complex industrial wastewaters that contain easily biodegradable organics as well as refractory pollutants.

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