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Using the converse of Noether’s first theorem, this chapter shows that the Bessel-Hagen-type transformations are uniquely selected in the case of electrodynamics, which powerfully dissolves the methodological ambiguity at hand. It then considers how this line of argument applies to a variety of other cases, including in particular the challenge of defining an energy-momentum tensor for the gravitational field in linearised gravity. Finally, the search for proper Noether energy-momentum tensors is put into context with recent claims that Noether’s theorem and its converse make statements on equivalence classes of symmetries and conservation laws. The aim is to identify clearly the limitations of this latter move, and to develop this position by contrast with recent philosophical discussions about how symmetries relate to the representational capacities of theories.
Tom Beauchamp and James Childress‘s revolutionary textbook, Principles of Biomedical Ethics, shaped the field of bioethics in America and around the world. Midway through the Principle’s eight editions, however, the authors jettisoned their attempt to justify the four principles of bioethics —autonomy, beneficence, nonmaleficence, justice—in terms of ethical theory, replacing it with the idea that these principles are part of a common morality shared by all rational persons committed to morality, at all times, and in all places. Other commentators contend that their theory has never been empirically confirmed and is unfalsifiable, since counterexamples can be deemed irrational, or as held by those living lives not committed to morality. The thesis of this paper is that common morality theory is the artifact of a category mistake—conflating common areas regulated by moral norms with common norms regulating moral conduct—that accords mid-twentieth century American liberal morality the status of transcultural, transtemporal, eternal moral truths. Such a conception offers bioethicists no tools for analyzing moral change—moral progress, regress, reform, evolution, devolution, or revolution—no theoretical basis for deconstructing structural classicism, racism, and sexism, or for facilitating international cooperation on ethical issues in the context of culturally based moral differences.
We interviewed 1,208 healthcare workers with positive SARS-CoV-2 tests between October 2020 and June 2021 to determine likely exposure sources. Overall, 689 (57.0%) had community exposures (479 from household members), 76 (6.3%) had hospital exposures (64 from other employees including 49 despite masking), 11 (0.9%) had community and hospital exposures, and 432 (35.8%) had no identifiable source of exposure.
Group Name: CDC Prevention Epicenters Program Background: Reverse-transcriptase polymerase chain reaction (RT-PCR) tests are the reference standard for diagnosing SARS-CoV-2 infection, but false positives can occur and viral RNA may persist for weeks-to-months following recovery. Isolating such patients increases pressure on limited hospital resources and may impede care. Therefore, we quantified the percentage of patients who tested positive by RT-PCR yet were unlikely to be infectious and could be released from isolation. Methods: We prospectively identified all adults hospitalized at Brigham and Women’s Hospital (Boston, MA) who tested positive for SARS-CoV-2 by RT-PCR (primarily Hologic Panther Fusion or Cepheid Xpert platforms) between December 24, 2020, and January 24, 2021. Each case was assessed by infection control staff for possible discontinuation of isolation using an algorithm that incorporated the patient’s prior history of COVID-19, current symptoms, RT-PCR cycle threshold (Ct) values, repeat RT-PCR testing at least 24 hours later, and SARS-CoV-2 serologies (Figure 1). Results: Overall, 246 hospitalized patients (median age, 66 years [interquartile range, 50–74]; 131 [53.3%] male) tested positive for SARS-CoV-2 by RT-PCR during the study period. Of these, 201 (81.7%) were deemed new diagnoses of active disease on the basis of low Ct values and/or progressive symptoms. Moreover, 44 patients (17.9%) were deemed noninfectious: 35 (14.2%) had prior known resolved infections (n = 21) or unknown prior infection but positive serology (n = 14), high Ct values on initial testing, and negative or stably high Ct values on repeat testing. Also, 5 (2.0%) had recent infection but >10 days had passed since symptom onset and they were clinically improving. In addition, 4 (1.6%) results were deemed false positives based on lack of symptoms and at least 1 negative repeat RT-PCR test (Figure 2). One patient was asymptomatic with Ct value <35 but was discharged before further testing could be obtained. Among the 44 noninfectious patients, isolation was discontinued a median of 3 days (IQR, 2–4) after the first positive test. We did not identify any healthcare worker infections attributable to early discontinuation of isolation in these patients. Conclusions: During the winter COVID-19 second surge in Massachusetts, nearly 1 in 5 hospitalized patients who tested positive for SARS-CoV-2 by RT-PCR were deemed noninfectious and eligible for discontinuation of precautions. Most of these cases were consistent with residual RNA from prior known or undiagnosed infections. Active assessments of SARS-CoV-2 RT-PCR tests by infection control practitioners using clinical data, Ct values, repeat tests, and serologies can safely validate the release many patients from isolation and thereby conserve resources and facilitate patient care.
The triarchic model was advanced as an integrative, trait-based framework for investigating psychopathy using different assessment methods and across developmental periods. Recent research has shown that the triarchic traits of boldness, meanness, and disinhibition can be operationalized effectively in youth, but longitudinal research is needed to realize the model's potential to advance developmental understanding of psychopathy. We report on the creation and validation of scale measures of the triarchic traits using questionnaire items available in the University of Southern California Risk Factors for Antisocial Behavior (RFAB) project, a large-scale longitudinal study of the development of antisocial behavior that includes measures from multiple modalities (self-report, informant rating, clinical-diagnostic, task-behavioral, physiological). Using a construct-rating and psychometric refinement approach, we developed triarchic scales that showed acceptable reliability, expected intercorrelations, and good temporal stability. The scales showed theory-consistent relations with external criteria including measures of psychopathy, internalizing/externalizing psychopathology, antisocial behavior, and substance use. Findings demonstrate the viability of measuring triarchic traits in the RFAB sample, extend the known nomological network of these traits into the developmental realm, and provide a foundation for follow-up studies examining the etiology of psychopathic traits and their relations with multimodal measures of cognitive-affective function and proneness to clinical problems.
We report on COVID-19 risk among HCWs exposed to a patient diagnosed with COVID-19 on day 13 of hospitalization. There were 44 HCWs exposed to the patient before contact and droplet precautions were implemented: of these, 2 of 44 (5%) developed COVID-19 potentially attributable to the exposure.
One major challenge in the study of late-Quaternary extinctions (LQEs) is providing better estimates of past megafauna abundance. To show how megaherbivore population size varied before and after the last extinctions in interior Alaska, we use both a database of radiocarbon-dated bone remains (spanning 25–0 ka) and spores of the obligate dung fungus, Sporormiella, recovered from radiocarbon-dated lake-sediment cores (spanning 17–0 ka). Bone fossils show that the last stage of LQEs in the region occurred at about 13 ka ago, but the number of megaherbivore bones remains high into the Holocene. Sporormiella abundance also remains high into the Holocene and does not decrease with major vegetation changes recorded by arboreal pollen percentages. At two sites, the interpretation of Sporormiella was enhanced by additional dung fungal spore types (e.g., Sordaria). In contrast to many sites where the last stage of LQEs is marked by a sharp decline in Sporormiella abundance, in interior Alaska our results indicate the continuance of megaherbivore abundance, albeit with a major taxonomic turnover (including Mammuthus and Equus extinction) from predominantly grazing to browsing dietary guilds. This new and robust evidence implies that regional LQEs were not systematically associated with crashes of overall megaherbivore abundance.
Computational modeling is an important aspect of the research on nuclear waste materials. In particular, atomistic simulations, when used complementary to experimental efforts, contribute to the scientific basis of safety case for nuclear waste repositories. Here we discuss the state-of-the-art and perspectives of atomistic modeling for nuclear waste management on a few cases of successful synergy of atomistic simulations and experiments. In particular, we discuss here: (1) the potential of atomistic simulations to investigate the uranium oxidation state in mixed-valence uranium oxides and (2) the ability of cementitious barrier materials to retain radionuclides such as 226Ra and 90Sr, and of studtite/metastudtite secondary peroxide phases to incorporate actinides such as Np and Am. The new contribution we make here is the computation of the incorporation of Sr by C-S-H (calcium silicate hydrate) phases.
The Ross Ice Shelf (RIS) is host to a broadband, multimode seismic wavefield that is excited in response to atmospheric, oceanic and solid Earth source processes. A 34-station broadband seismographic network installed on the RIS from late 2014 through early 2017 produced continuous vibrational observations of Earth's largest ice shelf at both floating and grounded locations. We characterize temporal and spatial variations in broadband ambient wavefield power, with a focus on period bands associated with primary (10–20 s) and secondary (5–10 s) microseism signals, and an oceanic source process near the ice front (0.4–4.0 s). Horizontal component signals on floating stations overwhelmingly reflect oceanic excitations year-round due to near-complete isolation from solid Earth shear waves. The spectrum at all periods is shown to be strongly modulated by the concentration of sea ice near the ice shelf front. Contiguous and extensive sea ice damps ocean wave coupling sufficiently so that wintertime background levels can approach or surpass those of land-sited stations in Antarctica.
Impact craters are the dominant landform on Mercury and range from the largest basins to the smallest young craters. Peak-ring basins are especially prevalent on Mercury, although basins of all forms are far undersaturated, probably the result of the extensive volcanic emplacement of intercrater plains and younger smooth plains between about 4.1 and 3.5 Ga. This chapter describes the geology of the two largest well-preserved basins, Caloris and Rembrandt, and the three smaller Raditladi, Rachmaninoff, and Mozart basins. We describe analyses of crater size–frequency distributions and relate them to populations of asteroid impactors (Late Heavy Bombardment in early epochs and the near-Earth asteroid population observable today during most of Mercury’s history), to secondary cratering, and to exogenic and endogenic processes that degrade and erase craters. Secondary cratering is more important on Mercury than on other solar system bodies and shaped much of the surface on kilometer and smaller scales, compromising our ability to use craters for relative and absolute age-dating of smaller geological units. Failure to find “vulcanoids” and satellites of Mercury suggests that such bodies played a negligible role in cratering Mercury. We describe an absolute cratering chronology for Mercury’s geological evolution as well as its uncertainties.
Conservation resources are limited, yet an increasing number of species are under threat. Assessing species for their conservation needs is, therefore, a vital first step in identifying and prioritizing species for both ex situ and in situ conservation actions. Using a transparent, logical and objective method, the Conservation Needs Assessment process developed by Amphibian Ark uses current knowledge of species in the wild to determine those with the most pressing conservation needs, and provides a foundation for the development of holistic conservation action plans that combine in situ and ex situ actions as appropriate. These assessments allow us to maximize the impact of limited conservation resources by identifying which measures could best serve those species requiring help. The Conservation Needs Assessment complements the IUCN Red List assessment, and together they provide a more holistic guide to conservation priorities and actions. Conservation Needs Assessments generate national prioritized lists of species recommended for conservation action. These can subsequently be used to assist in the development of species recovery plans and national action plans, or to inform national conservation priorities better. Additional tools that will evaluate the recommendations for ex situ rescues, to determine the best candidates for conservation breeding programmes, are currently under development.
Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.
The Institute of Translational Health Sciences (ITHS) promotes and supports translational research collaboration between clinicians, communities, and investigators across the five-state Washington, Wyoming, Alaska, Montana, and Idaho (WWAMI) region. The ITHS has developed a collaborative regional clinical research network, the Northwest Participant & Clinical Interactions Network (NW PCI), involving 12 diverse clinical health systems and academic institutions.
This descriptive article details NW PCI’s development, infrastructure and governance, tools, characteristics, and initial outcomes.
Regional NW PCI sites are conducting largely industry-sponsored studies; they are interested in including more grant-funded research. Regional NW PCI sites had over 1,240 open studies involving over 6700 patients in 2016. NW PCI trials are largely industry-sponsored; NW PCI sites are interested in including more grant-funded research. In its first three years, the NW PCI Coordinating Center facilitated regional sites’ participation in 34 new grant and contract applications across diverse topics.
The NW PCI model supports the goals of the developing CTSA Trial Innovation Network by increasing access to cutting-edge research across the Northwestern U.S., by supporting investigators seeking diverse populations, including those with rare diseases, for their research studies, and by providing settings to test implementation and dissemination of effective interventions.
Emerging research indicates the critical role members of the public can play in saving lives and reducing morbidity at the scene in the immediate aftermath of a disaster. It is anticipated that with training, more members of the public will be ready and able to assist should they be present at mass casualty events or other circumstances in which there are serious injuries or potential loss of life. This article describes a training course developed by multiple federal and nonfederal partners aimed at preparing the public to become “active bystanders” followed by a pilot demonstration project conducted by Medical Reserve Corps Units. The outcomes of the project indicated that the training was comprehensive and appropriate for members of the public with little or no first aid knowledge. National availability of the “Becoming an Active Bystander” training course is currently being planned. (Disaster Med Public Health Preparedness. 2016;10:286–292).