12,388 research outputs found
âFor her own safety and the good of society at largeâ: Eugenics, Sterilization, and Anglo-American Transnationalism in Newfoundland, 1928-1934
From 1928 to 1934, about half of the two dozen women who were surgically sterilized while under the care of American doctors working with the International Grenfell Association (IGA) in St. Anthony, Newfoundland, were sterilized because they were deemed to be mentally unfit or substandard. These sterilizations coincided with rising concern about feebleminded persons and eugenic and legislative solutions across the United States, the British Empire, and beyond, but Newfoundland did not develop a eugenic movement nor did it enact laws to sanction surgical sterilization. What happened in St. Anthony was a result of the otherwise beneficial âAmericanizationâ of the IGA.Environ la moitiĂ© des deux douzaines de femmes qui subirent une stĂ©rilisation chirurgicale entre 1928 et 1934 alors quâelles Ă©taient soignĂ©es par des mĂ©decins amĂ©ricains qui travaillaient pour lâInternational Grenfell Association (IGA) Ă St. Anthony (Terre-Neuve) furent stĂ©rilisĂ©es parce quâelles Ă©taient considĂ©rĂ©es comme mentalement inaptes ou infĂ©rieures. Ces stĂ©rilisations coĂŻncidaient avec la montĂ©e des prĂ©occupations suscitĂ©es par les personnes dâesprit faible et des solutions eugĂ©niques et lĂ©gislatives adoptĂ©es aux Ătats-Unis, dans lâempire britannique et au-delĂ . Aucun mouvement eugĂ©nique ne vit cependant le jour Ă Terre-Neuve, qui nâadopta pas de lois pour approuver la stĂ©rilisation chirurgicale. Ce qui se produisit Ă St. Anthony Ă©tait le rĂ©sultat de lâamĂ©ricanisation de lâIGA, qui fut par ailleurs bĂ©nĂ©fique
The First World War Centenary in the UK: âA Truly National Commemorationâ?
Prime Minister David Cameron has called for âa truly national commemoration of the First World Warâ. This article shows this to be problematic, politicised and contested. This is in part due to the elision of English and British histories. Scottish, Welsh and Irish responses are noted, and the role and commemorations of âour friends in the Commonwealthâ. There are tensions around interpretations of empire and race. There has been a failure to appreciate that the debates about the legacies of the First World War are deeply entangled with those of colonialism
PredictChain: Empowering Collaboration and Data Accessibility for AI in a Decentralized Blockchain-based Marketplace
Limited access to computing resources and training data poses significant
challenges for individuals and groups aiming to train and utilize predictive
machine learning models. Although numerous publicly available machine learning
models exist, they are often unhosted, necessitating end-users to establish
their computational infrastructure. Alternatively, these models may only be
accessible through paid cloud-based mechanisms, which can prove costly for
general public utilization. Moreover, model and data providers require a more
streamlined approach to track resource usage and capitalize on subsequent usage
by others, both financially and otherwise. An effective mechanism is also
lacking to contribute high-quality data for improving model performance. We
propose a blockchain-based marketplace called "PredictChain" for predictive
machine-learning models to address these issues. This marketplace enables users
to upload datasets for training predictive machine learning models, request
model training on previously uploaded datasets, or submit queries to trained
models. Nodes within the blockchain network, equipped with available computing
resources, will operate these models, offering a range of archetype machine
learning models with varying characteristics, such as cost, speed, simplicity,
power, and cost-effectiveness. This decentralized approach empowers users to
develop improved models accessible to the public, promotes data sharing, and
reduces reliance on centralized cloud providers
Physiological, genomic, and sulfur isotopic characterization of methanol metabolism by Desulfovibrio carbinolicus
Methanol is often considered as a non-competitive substrate for methanogenic archaea, but an increasing number of sulfate-reducing microorganisms (SRMs) have been reported to be capable of respiring with methanol as an electron donor. A better understanding of the fate of methanol in natural or artificial anaerobic systems thus requires knowledge of the methanol dissimilation by SRMs. In this study, we describe the growth kinetics and sulfur isotope effects of Desulfovibrio carbinolicus, a methanol-oxidizing sulfate-reducing deltaproteobacterium, together with its genome sequence and annotation. D. carbinolicus can grow with a series of alcohols from methanol to butanol. Compared to longer-chain alcohols, however, specific growth and respiration rates decrease by several fold with methanol as an electron donor. Larger sulfur isotope fractionation accompanies slowed growth kinetics, indicating low chemical potential at terminal reductive steps of respiration. In a medium containing both ethanol and methanol, D. carbinolicus does not consume methanol even after the cessation of growth on ethanol. Among the two known methanol dissimilatory systems, the genome of D. carbinolicus contains the genes coding for alcohol dehydrogenase but lacks enzymes analogous to methanol methyltransferase. We analyzed the genomes of 52 additional species of sulfate-reducing bacteria that have been tested for methanol oxidation. There is no apparent relationship between phylogeny and methanol metabolizing capacity, but most gram-negative methanol oxidizers grow poorly, and none carry homologs for methyltransferase (mtaB). Although the amount of available data is limited, it is notable that more than half of the known gram-positive methanol oxidizers have both enzymatic systems, showing enhanced growth relative to the SRMs containing only alcohol dehydrogenase genes. Thus, physiological, genomic, and sulfur isotopic results suggest that D. carbinolicus and close relatives have the ability to metabolize methanol but likely play a limited role in methanol degradation in most natural environments
Photoabsorption spectra of the diamagnetic hydrogen atom in the transition regime to chaos: Closed orbit theory with bifurcating orbits
With increasing energy the diamagnetic hydrogen atom undergoes a transition
from regular to chaotic classical dynamics, and the closed orbits pass through
various cascades of bifurcations. Closed orbit theory allows for the
semiclassical calculation of photoabsorption spectra of the diamagnetic
hydrogen atom. However, at the bifurcations the closed orbit contributions
diverge. The singularities can be removed with the help of uniform
semiclassical approximations which are constructed over a wide energy range for
different types of codimension one and two catastrophes. Using the uniform
approximations and applying the high-resolution harmonic inversion method we
calculate fully resolved semiclassical photoabsorption spectra, i.e.,
individual eigenenergies and transition matrix elements at laboratory magnetic
field strengths, and compare them with the results of exact quantum
calculations.Comment: 26 pages, 9 figures, submitted to J. Phys.
Semiclassical quantization of the hydrogen atom in crossed electric and magnetic fields
The S-matrix theory formulation of closed-orbit theory recently proposed by
Granger and Greene is extended to atoms in crossed electric and magnetic
fields. We then present a semiclassical quantization of the hydrogen atom in
crossed fields, which succeeds in resolving individual lines in the spectrum,
but is restricted to the strongest lines of each n-manifold. By means of a
detailed semiclassical analysis of the quantum spectrum, we demonstrate that it
is the abundance of bifurcations of closed orbits that precludes the resolution
of finer details. They necessitate the inclusion of uniform semiclassical
approximations into the quantization process. Uniform approximations for the
generic types of closed-orbit bifurcation are derived, and a general method for
including them in a high-resolution semiclassical quantization is devised
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