Adaptive foraging behaviours in the Horn of Africa during Toba supereruption.

Although modern humans left Africa multiple times over 100,000 years ago, those broadly ancestral to non-Africans dispersed less than 100,000 years ago1. Most models hold that these events occurred through green corridors created during humid periods because arid intervals constrained population movements2. Here we report an archaeological site-Shinfa-Metema 1, in the lowlands of northwest Ethiopia, with Youngest Toba Tuff cryptotephra dated to around 74,000 years ago-that provides early and rare evidence of intensive riverine-based foraging aided by the likely adoption of the bow and arrow. The diet included a wide range of terrestrial and aquatic animals. Stable oxygen isotopes from fossil mammal teeth and ostrich eggshell show that the site was occupied during a period of high seasonal aridity. The unusual abundance of fish suggests that capture occurred in the ever smaller and shallower waterholes of a seasonal river during a long dry season, revealing flexible adaptations to challenging climatic conditions during the Middle Stone Age. Adaptive foraging along dry-season waterholes would have transformed seasonal rivers into 'blue highway' corridors, potentially facilitating an out-of-Africa dispersal and suggesting that the event was not restricted to times of humid climates. The behavioural flexibility required to survive seasonally arid conditions in general, and the apparent short-term effects of the Toba supereruption in particular were probably key to the most recent dispersal and subsequent worldwide expansion of modern humans.

Assessment of breast self- examination practice and associated factors among female workers in Debre Tabor Town public health facilities, North West Ethiopia, 2018: Cross- sectional study.

BACKGROUND: Although breast Self-Examination is no longer tenable as a standard method to detect early breast cancer, world health organization recommends breast self -examination for raising awareness of women about breast cancer. Secondary prevention through monthly breast self-examination is the best option to tackle the rising incidence of breast cancer. Therefore, the aim of this study was to assess breast self -examination practice and associated factors. METHODS: This cross-sectional study was conducted from April 23 to May 23, 2018. A total of 421 female workers in Debre Tabor Town public health facilities were included. The study participants were selected using simple random sampling technique from the study population. The collected data were checked for completeness. The data were entered and cleaned using EpiData version 3.1 then exported to SPSS version 20 for analysis. Crude odd ratio and probability value were identified for each independent variable and all independent variables with probability value of less than 0.2 were entered into multivariables logistic regression. Statistically significant associated factors were identified based on probability value (p-value) less than 0.05 and adjusted odd ratio with 95% confidence interval. RESULT: The mean age of participants was 25.2 (S.D = 4.12) and 137 (32.5%) of the participants had practiced breast self -examination and 64 (15.2%) of them performed it monthly. Family history of breast cancer (adjusted OR = 6.5, CI = 1.54-21.4), Knowledge about breast -self examination (adjusted OR = 5.74, CI = 2.3-14.4) and self- efficacy in practicing breast self -examination (adjusted OR = 4.7, CI = 1.84-12.11) were significantly associated with breast self -examination practice. CONCLUSIONS: The study showed that the prevalence of breast self-examination was low. Family history of breast cancer, knowledge about breast self -examination and self- efficacy in practicing breast self- examination did have statistically significant association with breast self-examination practice.