117 research outputs found

    City size and the spreading of COVID-19 in Brazil

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    The current outbreak of the coronavirus disease 2019 (COVID-19) is an unprecedented example of how fast an infectious disease can spread around the globe (especially in urban areas) and the enormous impact it causes on public health and socio-economic activities. Despite the recent surge of investigations about different aspects of the COVID-19 pandemic, we still know little about the effects of city size on the propagation of this disease in urban areas. Here we investigate how the number of cases and deaths by COVID-19 scale with the population of Brazilian cities. Our results indicate that large cities are proportionally more affected by COVID-19, such that every 1% rise in population is associated with 0.57% increase in the number of cases per capita and 0.25% in the number of deaths per capita. The difference between the scaling of cases and deaths indicates the case fatality rate decreases with city size. The latest estimates show that a 1% increase in population associates with a 0.14% reduction in the case fatality rate of COVID-19; however, this urban advantage has decreased over time. We interpret this to be due to the existence of proportionally more health infrastructure in the largest cities and a lower proportion of older adults in large urban areas. We also find the initial growth rate of cases and deaths to be higher in large cities; however, these growth rates tend to decrease in large cities and to increase in small ones during the long-term course of the pandemic

    Constraining New Physics with a Positive or Negative Signal of Neutrino-less Double Beta Decay

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    We investigate numerically how accurately one could constrain the strengths of different short-range contributions to neutrino-less double beta decay in effective field theory. Depending on the outcome of near-future experiments yielding information on the neutrino masses, the corresponding bounds or estimates can be stronger or weaker. A particularly interesting case, resulting in strong bounds, would be a positive signal of neutrino-less double beta decay that is consistent with complementary information from neutrino oscillation experiments, kinematical determinations of the neutrino mass, and measurements of the sum of light neutrino masses from cosmological observations. The keys to more robust bounds are improvements of the knowledge of the nuclear physics involved and a better experimental accuracy.Comment: 23 pages, 3 figures. Minor changes. Matches version published in JHE
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