3 research outputs found

    The common feeder cockroach Blaptica dubia shows increased transmission distance based on mode of acquisition of environmental bacteria

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    Although some researchers claim that cockroaches are masters of disease transmission, these claims have little to no scientific support. Most studies concerning cockroaches as a vector of disease only focus on the bacteria found on the body surface, not on whether cockroaches have actually transferred pathogenic bacteria via surface contact. We set out to determine if cockroaches would act as a mechanical vector for the transfer of the opportunistic pathogen, E. coli. Roaches were contaminated with Green fluorescent protein expressing E. coli (GFP-E.coli) broth by either walking the roach through a broth culture or by complete immersion in the culture.. We then ran the roaches down a sterile agar track and measured the length of the glowing trail. Roaches were able to transmit E.coli, but only for a continuous distance of less than 50 cm, with the occasional sporadic colony growing after that. Roaches that were immersed in bacterial broth tracked the bacterium further than those that only walked through the solution. This suggests that while cockroaches are capable of acting as a mechanical vector, they are not capable of transporting transient flora over long distances. Future studies should explore this mechanism

    Health and development from preconception to 20 years of age and human capital

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    Optimal health and development from preconception to adulthood are crucial for human flourishing and the formation of human capital. The Nurturing Care Framework, as adapted to age 20 years, conceptualises the major influences during periods of development from preconception, through pregnancy, childhood, and adolescence that affect human capital. In addition to mortality in children younger than 5 years, stillbirths and deaths in 5–19-year-olds are important to consider. The global rate of mortality in individuals younger than 20 years has declined substantially since 2000, yet in 2019 an estimated 8·6 million deaths occurred between 28 weeks of gestation and 20 years of age, with more than half of deaths, including stillbirths, occurring before 28 days of age. The 1000 days from conception to 2 years of age are especially influential for human capital. The prevalence of low birthweight is high in sub-Saharan Africa and even higher in south Asia. Growth faltering, especially from birth to 2 years, occurs in most world regions, whereas overweight increases in many regions from the preprimary school period through adolescence. Analyses of cohort data show that growth trajectories in early years of life are strong determinants of nutritional outcomes in adulthood. The accrual of knowledge and skills is affected by health, nutrition, and home resources in early childhood and by educational opportunities in older children and adolescents. Linear growth in the first 2 years of life better predicts intelligence quotients in adults than increases in height in older children and adolescents. Learning-adjusted years of schooling range from about 4 years in sub-Saharan Africa to about 11 years in high-income countries. Human capital depends on children and adolescents surviving, thriving, and learning until adulthood
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