No abstract

VEGF-B was discovered a long time ago. However, unlike VEGF-A, whose function has been extensively studied, the function of VEGF-B and the mechanisms involved still remain poorly understood. Notwithstanding, drugs that inhibit VEGF-B and other VEGF family members have been used to treat patients with neovascular diseases. It is therefore critical to have a better understanding of VEGF-B function and the underlying mechanisms. Here, using comprehensive methods and models, we have identified VEGF-B as a potent antioxidant. Loss of Vegf-b by gene deletion leads to retinal degeneration in mice, and treatment with VEGF-B rescues retinal cells from death in a retinitis pigmentosa model. Mechanistically, we demonstrate that VEGF-B up-regulates numerous key antioxidative genes, particularly, Gpx1. Loss of Gpx1 activity largely diminished the antioxidative effect of VEGF-B, demonstrating that Gpx1 is at least one of the critical downstream effectors of VEGF-B. In addition, we found that the antioxidant function of VEGF-B is mediated mainly by VEGFR1. Given that oxidative stress is a crucial factor in numerous human diseases, VEGF-B may have therapeutic value for the treatment of such diseases.

Abstract-There is consensus that rural farmers' livelihoods are vulnerable to climate change. Also, literature suggests that locally driven adaptations are critical complementary strategies that can be targeted to reduce the negative effects of climate change in the short-run. Thus far, through using a cross sectional survey sample of 200 rural farmers from the Amathole district municipality of the Eastern Cape Province of South Africa, the paper estimated farmers' climate change adaptation strategies, adaptation portfolio diversity and factors that condition farmers' adoption behavior. The results reveal several crop, livestock and non-farm based adaptation strategies skewed in favour of crop and non-farm floral based techniques. The results further indicate that rural farmers in general are low adopters of climate change adaptation strategies with poor adaptation portfolio diversity. Regression estimates reveal several socio-economic and institutional factors as drivers of adoption and adaptation portfolio diversity worth targeting to promote the ability of rural farmers to cope with climate change.

This study determined the level and causes of food insecurity of 150 households, in the Eastern Cape Province of South Africa using the Household Food Insecurity Access Prevalence (HFIAP) and the Household Food Insecurity Access Scale (HFIAS). The majority (67.7 %) of the households interviewed were severely food insecure, the main cause being the abandonment of own food production. Average HFIAS for the sample was 12.41 and ranged from 0 to 27. Most households were dependent on government social grants for household food requirements rather than own food production or food purchases, using wages and remittances. Households in the study area were net purchasers of food, as is the situation in most rural households of South Africa. High levels of unemployment (97.5 %) among household heads were observed in the study areas. In times of food shortages, most households relied on borrowing from shops against future payment. Most of the food insecurity coping strategies used by the households had longterm detrimental effects. The ultimate way to improve the food security in rural South Africa is to increase per capita incomes and/or ensure that households have the resources and capacity to produce their own food through farming.