Plant and bird phenology and plant occurrence from 1851 to 2020 (non-continuous) in Thoreau's Concord, Massachusetts.

Concord, Massachusetts, USA has served as an active location for phenological observations since philosopher and naturalist Henry David Thoreau began recording plant and animal occurrence and phenology in 1851. Since that time, numerous naturalists, scientists, and researchers have continued this tradition, creating an invaluable time series of 758 species in a single location. In total, 13,441 phenological records, spanning 118 years, now exist, with observations of many species ongoing. Relative abundance data for an additional 200 plant species is also provided. Thoreau's published journals and records in Special Collections libraries at the Concord Free Public Library, Harvard University, Peabody Essex Museum, and Morgan Library and Museum provide insight into his methods of routinely walking around Walden Pond, through natural areas, and within the town of Concord, seeking the first leaf or flower on plants, seasonal observations of migratory birds, and fruit maturation times. Several amateur naturalists, and most recently the present research group, have followed this method of regularly searching Concord for the earliest signs of seasonal events, visiting many of the same locations including Walden Pond, the site made famous by Thoreau. While Thoreau's observations were initially made out of a curious desire to document the natural world, these data have led to dozens to contemporary studies, addressing timely issues such as climate change, conservation, ecology, and invasive species. This time series of data, initiated by Thoreau and continued by others, has resulted in dozens of peer-reviewed publications, a popular science book, and numerous educational and outreach opportunities. These data grow increasingly valuable with time and as new and creative studies are undertaken with Thoreau's historic records. No copyright restrictions apply to the use of this data set other than citing this publication.

Henry Jacob Bigelow Inhaled Nitrous Oxide While an Undergraduate at Harvard College.

When teenaged Henry Jacob Bigelow was an undergraduate at Harvard College in 1833-1837, he prepared nitrous oxide gas for demonstrations to other students. Bigelow's son, William Sturgis Bigelow, related the claim, and there is an eyewitness account from Augustus Goddard Peabody, a fellow Harvard undergraduate with Bigelow. Peabody wrote to Henry David Thoreau about a nitrous frolic. College chemistry primed Bigelow to support the concept of inhaled surgical anesthesia when the idea came to Boston in 1845-1846. Bigelow's chemistry professor was John White Webster. According to Harvard alumnus Edward Everett Hale, in addition to demonstrating effects of nitrous oxide, Webster presciently treated two cases of carbon monoxide poisoning with copious volumes of synthetic oxygen gas. The career of Webster was inhibited by financial difficulties that were suspected to be contributory when he was convicted of the 1849 murder of physician George Parkman at the Harvard Medical School, then adjacent to Massachusetts General Hospital and its Ether Dome. Webster suffered the death penalty in 1850.

Conscience, conscientious objections, and medicine.

To inform the ongoing discussion of whether claims of conscientious objection allow medical professionals to refuse to perform tasks that would otherwise be their duty, this paper begins with a review of the philosophical literature that describes conscience as either a moral sense or the dictate of reason. Even though authors have starkly different views on what conscience is, advocates of both approaches agree that conscience should be obeyed and that keeping promises is a conscience-given moral imperative. The paper then considers exemplars of conscientious objection-Henry David Thoreau, Mohandas Gandhi, and Martin Luther King Jr.-to identify the critical feature of conscientious objection as willingness to bear the burdens of one's convictions. It concludes by showing that medical professionals who put their own interests before their patients' welfare violate their previous commitments and misappropriate the title "conscientious objector" because they are unwilling to bear the burdens of their choices and instead impose burdens on their patients and colleagues.

Drivers of leaf-out phenology and their implications for species invasions: insights from Thoreau's Concord.

To elucidate climate-driven changes in leaf-out phenology and their implications for species invasions, we observed and experimentally manipulated leaf out of invasive and native woody plants in Concord, MA, USA. Using observations collected by Henry David Thoreau (1852-1860) and our own observations (2009-2013), we analyzed changes in leaf-out timing and sensitivity to temperature for 43 woody plant species. We experimentally tested winter chilling requirements of 50 species by exposing cut branches to warm indoor temperatures (22°C) during the winter and spring of 2013. Woody species are now leafing out an average of 18 d earlier than they did in the 1850s, and are advancing at a rate of 5 ± 1 d °C(-1) . Functional groups differ significantly in the duration of chilling they require to leaf out: invasive shrubs generally have weaker chilling requirements than native shrubs and leaf out faster in the laboratory and earlier in the field; native trees have the strongest chilling requirements. Our results suggest that invasive shrub species will continue to have a competitive advantage as the climate warms, because native plants are slower to respond to warming spring temperatures and, in the future, may not meet their chilling requirements.