Project description:Charles Darwin is largely unknown and poorly understood as a historical figure. Similarly the fundamental principles of evolution are often misstated, misunderstood, or entirely rejected by large numbers of Americans. Simply trying to communicate more facts about Darwin, or facts supporting the principles of evaluation, is inadequate; neither students nor members of the public will care or retain the information. On the contrary, building facts into a one-on-one conversational narrative creates a memorable opportunity to learn. Here we create a digital media, self-guided question and answer 'synthetic interview' with Charles Darwin. Questions are derived from a survey of nearly 1,000 people. Answers spoken by an actor portraying Darwin are derived from Darwin's own writings. Questions on modern topics are answered by scientists, theologians, and lawyers. First produced as a museum exhibit and then later reproduced as an app (iOS/Android), the Darwin Synthetic Interview has been evaluated with more than 3,000 surveyed users, of which 69% indicated that they learned and more than 75% would recommend the experience. Students who interacted with the synthetic interview in a classroom setting found answers were unexpected and clarifying. Using a format of personal narrative, the Darwin Synthetic Interview creates a new way to engage students and the public in a process of self-directed discovery of a topic that is often considered difficult to teach.

| S-EPMC7351126 | biostudies-literature

Shedding light on 19th century spectra by analyzing Lippmann photography.

Project description:From uncovering the structure of the atom to the nature of the universe, spectral measurements have helped some of science's greatest discoveries. While pointwise spectral measurements date back to Newton, it is commonly thought that hyperspectral images originated in the 1970s. However, the first hyperspectral images are over a century old and are locked in the safes of a handful of museums. These hidden treasures are examples of the first color photographs and earned their inventor, Gabriel Lippmann, the 1908 Nobel Prize in Physics. Since the original work of Lippmann, the process has been predominately understood from the monochromatic perspective, with analogies drawn to Bragg gratings, and the polychromatic case treated as a simple extension. As a consequence, there are misconceptions about the invertibility of the Lippmann process. We show that the multispectral image reflected from a Lippmann plate contains distortions that are not explained by current models. We describe these distortions by directly modeling the process for general spectra and devise an algorithm to recover the original spectra. This results in a complete analysis of the Lippmann process. Finally, we demonstrate the accuracy of our recovery algorithm on self-made Lippmann plates, for which the acquisition setup is fully understood. However, we show that, in the case of historical plates, there are too many unknowns to reliably recover 19th century spectra of natural scenes.

| S-EPMC8092472 | biostudies-literature

Changes in Atlantic major hurricane frequency since the late-19th century.

Project description:Atlantic hurricanes are a major hazard to life and property, and a topic of intense scientific interest. Historical changes in observing practices limit the utility of century-scale records of Atlantic major hurricane frequency. To evaluate past changes in frequency, we have here developed a homogenization method for Atlantic hurricane and major hurricane frequency over 1851-2019. We find that recorded century-scale increases in Atlantic hurricane and major hurricane frequency, and associated decrease in USA hurricanes strike fraction, are consistent with changes in observing practices and not likely a true climate trend. After homogenization, increases in basin-wide hurricane and major hurricane activity since the 1970s are not part of a century-scale increase, but a recovery from a deep minimum in the 1960s-1980s. We suggest internal (e.g., Atlantic multidecadal) climate variability and aerosol-induced mid-to-late-20th century major hurricane frequency reductions have probably masked century-scale greenhouse-gas warming contributions to North Atlantic major hurricane frequency.

| S-EPMC8277888 | biostudies-literature

Mycobacterium tuberculosis complex in remains of 18th-19th century slaves, Brazil.

Project description: Not available

| S-EPMC3647487 | biostudies-literature

Placebos in 19th century medicine: a quantitative analysis of the BMJ.

Project description:ObjectiveTo provide the first quantitative data on the use of the term "placebo" in the 19th century.DesignComputer search of BMJ's archival database from January 1840 (the first issue) through December 1899 for uses of the words "placebo(s)." Grounded theory was used to categorise the implications of uses of the term.Results71 citations contained the term "placebo(s)." Of these, 22 (31%) used the term to mean "no effect" or as a general pejorative term, 18 (25%) portrayed placebo treatment as permitting the unfolding of the natural history (the normal waxing and waning of illness), 14 (20%) described placebo as important to satisfy patients, 7 (10%) described it as fulfilling a physician's performance role, 3 (4%) described its use to buy time, 3 (4%) described its use for financial gain, 2 (3%) used it in a manner similar to a placebo control, and only one implied that placebo could have a clinical effect. Only one citation mentioned telling the patient about his placebo treatment.ConclusionNineteenth century physicians had diverse a priori assumptions about placebos. These findings remind us that contemporary medicine needs to use rigorous science to separate fact from its own beliefs concerning the "provision of care." As in previous generations, ethical issues concerning placebos continue to challenge medicine.

| S-EPMC3525309 | biostudies-literature

A demographic transition altered the strength of selection for fitness and age-specific survival and fertility in a 19th century American population.

Project description:Modernization has increased longevity and decreased fertility in many human populations, but it is not well understood how or to what extent these demographic transitions have altered patterns of natural selection. I integrate individual-based multivariate phenotypic selection approaches with evolutionary demographic methods to demonstrate how a demographic transition in 19th century female populations of Utah altered relationships between fitness and age-specific survival and fertility. Coincident with this demographic transition, natural selection for fitness, as measured by the opportunity for selection, increased by 13% to 20% over 65 years. Proportional contributions of age-specific survival to total selection (the complement to age-specific fertility) diminished from approximately one third to one seventh following a marked increase in infant survival. Despite dramatic reductions in age-specific fertility variance at all ages, the absolute magnitude of selection for fitness explained by age-specific fertility increased by approximately 45%. I show that increases in the adaptive potential of fertility traits followed directly from decreased population growth rates. These results suggest that this demographic transition has increased the adaptive potential of the Utah population, intensified selection for reproductive traits, and de-emphasized selection for survival-related traits.

| S-EPMC3675805 | biostudies-literature

Human genetic variation and yellow fever mortality during 19th century U.S. epidemics.

Project description:UnlabelledWe calculated the incidence, mortality, and case fatality rates for Caucasians and non-Caucasians during 19th century yellow fever (YF) epidemics in the United States and determined statistical significance for differences in the rates in different populations. We evaluated nongenetic host factors, including socioeconomic, environmental, cultural, demographic, and acquired immunity status that could have influenced these differences. While differences in incidence rates were not significant between Caucasians and non-Caucasians, differences in mortality and case fatality rates were statistically significant for all epidemics tested (P < 0.01). Caucasians diagnosed with YF were 6.8 times more likely to succumb than non-Caucasians with the disease. No other major causes of death during the 19th century demonstrated a similar mortality skew toward Caucasians. Nongenetic host factors were examined and could not explain these large differences. We propose that the remarkably lower case mortality rates for individuals of non-Caucasian ancestry is the result of human genetic variation in loci encoding innate immune mediators.ImportanceDifferent degrees of severity of yellow fever have been observed across diverse populations, but this study is the first to demonstrate a statistically significant association between ancestry and the outcome of yellow fever (YF). With the global burden of mosquito-borne flaviviral infections, such as YF and dengue, on the rise, identifying and characterizing host factors could prove pivotal in the prevention of epidemics and the development of effective treatments.

| S-EPMC4049105 | biostudies-literature

A decade of cold Eurasian winters reconstructed for the early 19th century.

Project description:Annual-to-decadal variability in northern midlatitude temperature is dominated by the cold season. However, climate field reconstructions are often based on tree rings that represent the growing season. Here we present cold-season (October-to-May average) temperature field reconstructions for the northern midlatitudes, 1701-1905, based on extensive phenological data (freezing and thawing dates of rivers, plant observations). Northern midlatitude land temperatures exceeded the variability range of the 18th and 19th centuries by the 1940s, to which recent warming has added another 1.5 °C. A sequences of cold winters 1808/9-1815/6 can be explained by two volcanic eruptions and unusual atmospheric flow. Weak southwesterlies over Western Europe in early winter caused low Eurasian temperatures, which persisted into spring even though the flow pattern did not. Twentieth century data and model simulations confirm this persistence and point to increased snow cover as a cause, consistent with sparse information on Eurasian snow in the early 19th century.

| S-EPMC9019108 | biostudies-literature

Susan Field

Project description: Not available

| S-EPMC1289341 | biostudies-literature