DATA SET MEDFPNAS.DAT:
EFFECTS OF DIET AND GENDER ON LONGEVITY OF MEDFLIES
The data set medfpnas.dat contains 4 x 33 lifetables of medflies (Ceratitis capitata), each cohort consisting of about 3000-4000 medflies.
The cohorts fall into 4 groups:
A. males on sugar diet
B. males on protein plus sugar diet
C. females on sugar diet
D. females on protein plus sugar diet.
A description of the experiment which was done by Professor Carey at UCD in a medfly rearing facility in Mexico is in Müller et al.(1997) below. The main questions are to quantify the effects (main and interactions) of nutrition and gender on mortality. A basic finding was that while on full (protein and sugar) diet, female medflies live longer than the males, this is not true under a reduced diet (sugar only), where female life expectancy is shorter than that for males. An analysis of this phenomenon by estimating nonparametric hazard rates from the lifetable data shows that the life expectancy reversal is due to an early peak in female mortality under protein free diet. This peak in mortality appears to be tied to the onset of reproduction. Principal components and biological parameters assigned to individual curves such as mortality peak location and height were discussed in Müller and Wang (1998). These data provide a setting for functional ANOVA.
Müller, H.G., Wang, J.L., Capra, W.B., Liedo, P., Carey, J.R. (1997). Early mortality surge in protein-deprived females causes reversal of sex differential of life expectancy in Mediterranean fruit flies. Proc. Nat. Acad. Sci. USA 94, 2762-2765.
Müller, H.G., Wang, J.L. (1998). Statistical tools for the analysis of nutrition effects on the survival of cohorts. Mathematical Modeling in Experimental Nutrition, Ed. A. Clifford, H.G. Müller, Advances in Experimental Medicine and Biology 445, Plenum Press, New York, 191-206.
The file contains 202 rows and 68 columns.
rows 1-101: columns 1 and 35 is day(i);
columns 2-34 are number alive at day(i) in cage(j) for males on sugar diet, j=1,...,33;
columns 36-68 are number alive at day(i) in cage(j) for males on sugar and protein diet, j=1,…33.
rows 102-202: columns 1 and 35 is day(i);
columns 2-34 are number alive at day(i) in cage(j): females on sugar diet, j=1,...,33;
columns 36-68 are number alive at day(i) in cage(j) for females on sugar and protein diet, j=1,…33.