The HIV Anticaptory Saving Motive: An Empirical Analysis in South Africa

This paper studies the effect of the HIV/AIDS epidemic on saving behaviour. Two important characteristics of HIV result in opposing forces on savings: mortality increases, which reduces savings, and long-term illness risk increases, which enhances savings. We use a two period life-cycle model with uncertain lifetime including perceived HIV contamination risk to illustrate both the opposing effects of the HIV epidemic on individual savings and test the predictions of our model with data obtained from an economic experiment with real monetary incentives performed in South Africa. The empirical results show that increased mortality decreases the amount of savings and that having a high perception of HIV contamination risk increases savings. The latter effect confirms the HIV anticipatory saving hypothesis.HIV/AIDS;saving behavior;illness risk;mortality;life-cycle model;time preferences

The Vascular Flora of Roggman Boreal Slopes Preserve, Clayton County, Iowa

Charles and Anna Roggman Boreal Slopes is a 20 acre (8.1 ha) Nature Conservancy preserve situated on the floodplain and adjacent northfacing slope of a tributary of Buck Creek in Clayton County, northeastern Iowa. My study of the preserve in 1981 revealed a vascular flora of 160 species representing 59 families. Three plant communities were recognized: ash-elm on the floodplain, maple-basswood on the slope, and an unusual boreal slope community in areas of the slope with cold air drainage. The last contains several species with boreal American or circumboreal distributions which have probably persisted since the Pleistocene. Eleven species protected by state and federal laws inhabit the preserve. The most significant is Aconitum noveboracense Gray, known from only 17 localities worldwide, listed as endangered in Iowa and as threatened in the United States

The Vascular Flora of Des Moines County, Iowa

Des Moines County is a 409 square mile (1060 km2) political subdivision located along the Mississippi River in southeastern Iowa. The vascular flora of the county was studied in the field and from herbarium specimens during 1975-80. The flora consists of 809 species, representing 109 families and 393 genera. This study adds 390 species to the previously known county flora, a 93% increase. Three species are added to the state flora: Chenopodium foggii H. A. Wahl, Holsosteum umbellatum L., and Lamium purpureum L. Nineteen species on the Iowa list of threatened and endangered vascular plants are reported from the county

Immunological and Physiological Differences Between Layer- and Broiler Chickens after Concurrent Intratracheal Administration of Lipopolysaccharide and Human Serum Albumin

Layers and broilers were concurrently intratracheally challenged with 0.5 mg Lipopolysaccharide (LPS) and 0.1 mg Human Serum Albumin (HuSA) at 3 weeks of age. Specific total and isotype-specific (IgM, IgG, IgA) Antibody (Ab) responses to HuSA during 3 weeks following immunization, cellular in vitro mitogen responses to Concanavalin A (Con A) and specific cellular responses in vitro to different dosages of HuSA, blood serotonin (5-HT) levels, plasma Corticosterone (CORT) levels at 6 weeks of age and ex vivo nitric oxide (NO) production in the presence of LPS, respectively, were measured in all birds. Higher in vitro cellular responses to HuSA, but not Con A, were found in the broilers than in the layers. Also higher total, IgM and IgG antibody responses to HuSA were found in the broilers. Higher ex vivo NO production was found in the layers. A heavier spleen weight was found in the broilers, but relative spleen weight was higher in the layers. The broilers grew much heavier and also maintained a higher growth during the first 24 and 48 h after i.t. challenge with LPS and HuSA. No breed effect was found for body temperature responses after i.t. challenge. Blood 5-HT levels and plasma CORT levels were significantly higher in the layers. Number and type of significant correlations between 5-HT levels, cachectin response to LPS, antibody levels and cellular immunity differed between breeds. Our data suggest comparable immune responses to i.t. HuSA challenge in broilers and layers of similar age and confirm the earlier reported higher humoral immune response in broilers. On the other hand, the cachectin response to LPS differed between broilers and layers. Our results do not confirm the earlier reported higher cellular immune response of layers. Different significant relationships between physiological parameters in broilers and layers were found. Our results suggest that selection for enhanced growth does not necessarily affect specific immune competence of poultr