1 / 14

x = age at beginning of the time interval S x = Number of survivors at start of interval

x = age at beginning of the time interval S x = Number of survivors at start of interval. d x = Number dying during interval l x = Proportion surviving at start of age interval = n x /n o.

gail
Download Presentation

x = age at beginning of the time interval S x = Number of survivors at start of interval

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. x = age at beginning of the time interval Sx = Number of survivors at start of interval

  2. dx = Number dying during interval lx = Proportion surviving at start of age interval = nx/no

  3. px = sx = age specific survival rate (probability of surviving to the end of the period) = (nx+1)/nx; = 1- qx qx = mx = age specific mortality rate (probability of dying before the end of the period) = (nx-(nx+1)) / nx = dx/nx = 1 - px

  4. Nx = Mean number of individuals alive during the period = (nx+nx+1)/2 Tx = sum of the time to be lived by the nx currently alive ex = age specific life expectancy

  5. kx = Exponential mortality = ln sx sx = e-kt

  6. Age specific fecundity of human females

  7. lxbx = Number of female individuals born during interval x. Gross Reproductive Rate (potential number of offspring) = bx Net Reproductive Rate (average number)= Ro = lxbx = ( Fx)/no

  8. G = cohort generation length = mean period elapsing between birth of parent and birth of offspring.  G = [(lxbxx)]/[(lxbx)] = 2.1/1.2 = 1.75 = (xFx)/Fx  (The time it takes) / (number produced)

  9. Calculation of r Recall Nt = Noert; set t=G  NG/No = erG = Ro r = ln(Ro)/G = ln(1.2)/1.75 = .104 r =(RolnRo)/ (lxbxx)

  10. Reproductive value vx = [erx/lx][  (e-rxlyby)] ; where summation over range y = x → ∞

More Related