Comparative effects of nano and bulk-Fe3O4 on the growth of cucumber (Cucumis sativus).

Cucumber (Cucumis sativus) plants were cultivated in hydroponic media with nano and bulk- iron oxide (Fe3O4) (50, 500 and 2000 mg/L) over a period of 21 days. At the low concentration (50 mg/L), nano-Fe3O4 resulted in reduction of biomass and enzyme activities compared to the control. However, at the higher concentration of nano-Fe3O4 dosage (2000 mg/L), there was a significant increase in biomass, antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD). In contrary, the high concentration of bulk-Fe3O4 caused phytotoxicity in terms of biomass and enzymes activity. The phytotoxicity was dependent on the particles property (mainly sizes and aggregation) for nano-F3O4 and concentration dependent for bulk-Fe3O4. The particle size is an important factor that can influence the bioavailability of nanomaterials, which need to be included when evaluating the exposure of nanomaterials and their deleterious effects in the environment. These promising results can help to develop the possible application of Fe3O4 NPs which may improve nutrient management to overcome food security.

Consumer perceptions and reported wild and domestic meat and fish consumption behavior during the Ebola epidemic in Guinea, West Africa.

The handling, capturing, butchering, and transportation of wildmeat can increase the risk of zoonoses, including the Ebola virus disease (EVD). Guinea, West Africa, experienced a catastrophic outbreak of EVD between 2013 and 2016. This study aimed to understand local people's sources of information concerning EVD, their perceptions of potential wildlife carriers of EVD and their meat and fish consumption behavior during this period. A semi-structured questionnaire was administered to 332 participants in two urban centers (N = 209) and three villages (N = 123) between January 3 and March 30, 2015 in the prefecture of Lola in southeastern Guinea. Chi-square analyses revealed that, in rural areas, awareness missions represented the main source of information about EVD (94.3%), whereas in urban settings such missions (36.1%), as well as newspapers (31.6%) and radio (32.3%) were equally mentioned. Bats (30.1% and 79.4%), chimpanzees (16.3% and 48.8%) and monkeys (13.0% and 53.1%) were the most commonly cited potential agents of EVD in both rural and urban areas respectively, while the warthog (2.3% rural and 6.5% urban), crested porcupine (1.7% rural and 10.7% urban), duiker (1.19% rural and 2.6% urban) and the greater cane rat (1.1% rural and 9.5% urban) were also cited but to a lesser extent. However, 66.7% of rural respondents compared to only 17.2% in the urban area did not consider any of these species as potential carriers of the Ebola virus. Nonetheless, a fifth of our respondents reported not consuming any of these species altogether during the EVD outbreak. Among all seven faunal groups mentioned, a significant reduction in reported consumption during the Ebola outbreak was only noted for bats (before: 78.3% and during: 31.9%) and chimpanzees (before: 31.6% and during: 13.5%). Automatic Chi-Square Interaction Detection (CHAID) analysis revealed that the belief that bats or chimpanzees were associated with EVD or not had a significant effect respectively on their non-consumption or continued consumption. However, only 3.9% of respondents reported shifting to alternative protein sources such as domestic meat or fish specifically to avoid EVD. Only 10.8% reported consuming more domestic meat during the EVD outbreak compared with before; affordability and availability were the main reported reasons for why people did not consume more domestic meat and why two thirds reported consuming more fish. While increased domestic meat consumption was linked to the belief that duikers, the most commonly consumed wildmeat before the epidemic, were associated with EVD, increased fish consumption was not predicted by any EVD related factors. Our study revealed deep-rooted false beliefs among rural respondents and constraints when it comes to access to alternative protein sources such as domestic meat. Our findings emphasize the urgent need for greater consideration of the relationship between socio-economic context, food security, and public health.