scholarly journals Ultimate Population Size under Changed Age Specific Fertility Schedule

2015 ◽  
Vol 20 (1) ◽  
pp. 138-140
Author(s):  
Roshan Aryal ◽  
T.R. Aryal
Keyword(s):  
Population Size ◽  
Science And Technology ◽  
Fertility Schedule ◽  
Linear Decline

This paper attempts to obtain ultimate population size under changed age specific fertility schedule. The reduction in fertility under exponential and linear decline has been discussed in order to obtain ultimate population size. A concept has been suggested to obtain ultimate population size by combining both exponential and linear decline pattern in age schedule due to faster reduction in fertility at the beginning and thereafter slower declining rate in fertility age schedule.Journal of Institute of Science and Technology, 2015, 20(1): 138-140

scholarly journals Population Projection under Changing Fertility Conditions

2015 ◽  
Vol 19 (2) ◽  
pp. 86-88
Author(s):  
Tika Ram Aryal
Keyword(s):  
Birth Rate ◽  
Science And Technology ◽  
Age Distribution ◽  
Natural Increase ◽  
Population Projection ◽  
Stability Conditions ◽  
Reproduction Rate ◽  
Fertility Schedule ◽  
Gradual Change ◽  
Net Reproduction

This paper attempts to derive model for population projection under gradual change in fertility schedule on stability conditions using birth trajectory at time t for 0 < t ? a . The projected population can be obtained when the data of the rate of natural increase, net reproduction rate, age variance of the net maternity function, birth rate of the initial stable population along with its age distribution are available of the population.Journal of Institute of Science and Technology, 2014, 19(2): 86-88

scholarly journals Capturing insects in guava orchard with soil trap

2020 ◽  
Vol 9 (4) ◽  
pp. e162943039
Author(s):  
Semirames do Nascimento Silva ◽  
Eliezer da Cunha Siqueira ◽  
Polyana Barbosa da Silva ◽  
Roberta de Oliveira Sousa Wanderley
Keyword(s):  
Surface Tension ◽  
Population Size ◽  
Soft Drink ◽  
Science And Technology ◽  
Accurate Data ◽  
Constant Frequency ◽  
Formica Rufa ◽  
Federal Institute ◽  
Education Science ◽  
Total Species

The development of equipment for capturing insects, in order to meet the need of technicians and researchers, is of paramount importance to obtain accurate data on the population of insects in a given area. The soil trap is used in order to have a sample of the population size of the macro fauna present in the soil.  The objective of the experiment was to capture insects of different orders with soil traps and to verify the constancy of the orders of insects in the Experimental Area of Guava Orchards of Federal Institute of Education, Science and Technology of Paraiba Campus Sousa, Unit II in São Gonçalo, Paraiba State. For this, six soil traps were installed, arranged in strategic points, with 30 m spacing between them, in a triangle shape. The traps were made of 2-liter plastic bottles (PET) of soft drink, cut in half and 10 cm in diameter and 15 cm high. Inside each bottle 300 mL of water and two tablespoons of neutral detergent were placed to break the surface tension of the water. The main orders of insects were respectively, Hymenoptera with 100% of the total species collected in the soil traps; Neuroptera 66.66%, Orthoptera 33.33% and Diptera with 33.33%. In the experiment, a constant frequency was observed, that is, those present in more than 50% of the collections, in particular the order Hymenoptera, with the red ant species (Formica rufa), followed by lion ant (Myrmeleon brasiliensis).

Laboratory Simulation of Lunar Luminescence

1962 ◽  
Vol 14 ◽  
pp. 441-444 ◽  
Author(s):  
J. E. Geake ◽  
H. Lipson ◽  
M. D. Lumb
Keyword(s):  
Science And Technology ◽  
Laboratory Simulation ◽  
The Moon ◽  
Physics Department ◽  
Luminescent Spectrum

Work has recently begun in the Physics Department of the Manchester College of Science and Technology on an attempt to simulate lunar luminescence in the laboratory. This programme is running parallel with that of our colleagues in the Manchester University Astronomy Department, who are making observations of the luminescent spectrum of the Moon itself. Our instruments are as yet only partly completed, but we will describe briefly what they are to consist of, in the hope that we may benefit from the comments of others in the same field, and arrange to co-ordinate our work with theirs.

Reduction of spermatogonia and testosterone in rat testes flown on space lab-3

1986 ◽  
Vol 44 ◽  
pp. 248-249
Author(s):  
Delbert E. Philpott ◽  
W. Sapp ◽  
C. Williams ◽  
T. Fast ◽  
J. Stevenson ◽  
...  
Keyword(s):  
Social Interaction ◽  
Social Status ◽  
Population Size ◽  
Physiological Response ◽  
Social Rank ◽  
Reproductive Function ◽  
Testicular Development ◽  
Organ Weights ◽  
Reproductive Maturation ◽  
Metabolic Activities

Space Lab 3 (SL-3) was flown on Shuttle Challenger providing an opportunity to measure the effect of spaceflight on rat testes. Cannon developed the idea that organisms react to unfavorable conditions with highly integrated metabolic activities. Selye summarized the manifestations of physiological response to nonspecific stress and he pointed out that atrophy of the gonads always occurred. Many papers have been published showing the effects of social interaction, crowding, peck order and confinement. Flickinger showed delayed testicular development in subordinate roosters influenced by group numbers, social rank and social status. Christian reported increasing population size in mice resulted in adrenal hypertrophy, inhibition of reproductive maturation and loss of reproductive function in adults. Sex organ weights also declined. Two male dogs were flown on Cosmos 110 for 22 days. Fedorova reported an increase of 30 to 70% atypical spermatozoa consisting of tail curling and/or the absence of a tail.

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