In the first 25 generations of his classical mutation accumulation experiment, T. Mukai estimated a large rate of early linear decay for the relative viability of Drosophila melanogaster chromosome II (delta MII = 0.004). Mukai forced through zero the regression of viability decline on generation number, but it has recently been shown (Fry, 2001) that a similar decline (delta MII = 0.006) is ob...

This paper analyses the correlation between employment duration, unemployment duration and general skill accumulation in a search equilibrium. I show how the level of general skills and the duration of employment are positively correlated, and both variables are negatively correlated with the duration of unemployment spells. With search frictions, general skill accumulation is associated with a...

introduction despite the limited anthropogenic activity in arctic regions, the levels of heavy metals are of concern and the arctic is considered as an important global sink for mercury depletion. mercury is not readily available to the food web in its natural form. however, inorganic mercury are converted to organic mercury compounds by microbial processes of anaerobic organisms. mehg is more ...

â â â â â â  â  abstract â  outward-oriented economies seem to grow faster than inward-looking ones. does the literature on convergence have anything to say on this? in the dynamic heckscher-ohlin-samuelson model, with factor-price equalization, there is no convergence of incomes. this is because with identical preferences and return to capital, irrespective of initial levels the growth rates o...

background: due to the presence of radioactive minerals such as monazite, the beach sand of the west coast of kanyakumari exhibits high natural background radiation. hair is a good indicator of radionuclides in the human body. an attempt is taken to measure the 210po activity in human hair samples and the factors affecting it. material and methods: 210po activity was analysed in 47 individuals ...

The effects of lead on the proline content and dry weight of leaves and roots were investigated in two canola cultivars (Brassica napus L.) grown in the Hoagland solution. The growth of treated plants was inhibited under lead stress. Lead induced differential accumulation of proline in canola grown in solution with the addition of 0, 100 and 200 mgL-1 of Pb. Hyola308 cultivar showed low biomass...

a study was conducted in 2010 to investigate the effects of crude oil contaminated soil on biomass accumulation injatropha curcas seedlings in asaba, delta state, nigeria. oil levels used were 0.0, 2.0, 4.0, 6.0, 8.0 and 10.0% w/w. the trial was arranged in a randomized complete block design with four replications and monitored for 12 weeks after transplanting. results showed that contamination...

cold tolerance is an adaptative mechanism that plants in temperate climates require to survive and grow in suboptimal temperatures.  exposed plant to low temperature produces a myriad of measurable changes in biochemical characters that are often highly correlated with plant cold tolerance.  a key element of cereal adaptation to cold is represented by the capacity for physiological adjustments ...