1,965 research outputs found
A Case Against School Choice: Carson Ex Rel. O.C. v. Makin and the Future of Maine\u27s Nonsectarian Requirement
School choice advocates, such as the nonprofit libertarian law firm, The Institute for Justice, have spent decades arguing that states violate the Free Exercise Clause when they exclude private religious schools from public programs that otherwise provide public dollars to non-religious private schools. Recently, in Espinoza v. Montana Department of Revenue, the Supreme Court effectively agreed with that sentiment. After this victory, the Institute for Justice returned to the state of Maine to represent three sets of parents in a renewed effort to defeat Maine’s nonsectarian requirement in federal court. Maine’s nonsectarian requirement provides that private religious schools may not participate in Maine’s town tuitioning program, which allows students in towns that do not have public schools to receive state funding to attend a private or public school of their choice.
This Note analyzes that case: Carson ex rel. O.C. v. Makin. In Carson, the First Circuit affirmed the trial court’s decision that Maine’s nonsectarian requirement does not violate the Free Exercise Clause. I posit that the reasoning the First Circuit deployed in Carson may not be durable and that if the Supreme Court were to grant the plaintiff-appellants’ petition for certiorari, the Court would likely invalidate Maine’s nonsectarian requirement. I then analyze the effect the elimination of the nonsectarian requirement would have on Maine’s public schools and how school choice opponents may wish to move forward. More specifically, I suggest that Maine and the rest of the nation should consider investing in its public schools before outsourcing public education to private entities and interest groups
Integral equations of a cohesive zone model for history-dependent materials and their numerical solution
A nonlinear history-dependent cohesive zone (CZ) model of quasi-static crack propagation in
linear elastic and viscoelastic materials is presented. The viscoelasticity is described by a linear
Volterra integral operator in time. The normal stress on the CZ satisfies the history-dependent yield
condition, given by a nonlinear Abel-type integral operator. The crack starts propagating, breaking
the CZ, when the crack tip opening reaches a prescribed critical value. A numerical algorithm for
computing the evolution of the crack and CZ in time is discussed along with some numerical
results
A physics-based life prediction methodology for thermal barrier coating systems
A novel mechanistic approach is proposed for the prediction of the life of
thermal barrier coating (TBC) systems. The life prediction methodology is based
on a criterion linked directly to the dominant failure mechanism. It relies on
a statistical treatment of the TBC's morphological characteristics,
non-destructive stress measurements and on a continuum mechanics framework to
quantify the stresses that promote the nucleation and growth of microcracks
within the TBC. The last of these accounts for the effects of TBC constituents'
elasto-visco-plastic properties, the stiffening of the ceramic due to sintering
and the oxidation at the interface between the thermally insulating yttria
stabilized zirconia (YSZ) layer and the metallic bond coat. The mechanistic
approach is used to investigate the effects on TBC life of the properties and
morphology of the top YSZ coating, metallic low-pressure plasma sprayed bond
coat and the thermally grown oxide. Its calibration is based on TBC damage
inferred from non-destructive fluorescence measurements using
piezo-spectroscopy and on the numerically predicted local TBC stresses
responsible for the initiation of such damage. The potential applicability of
the methodology to other types of TBC coatings and thermal loading conditions
is also discussed
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Science, society, and policy in the face of uncertainty: reflections on the debate around face coverings for the public during COVID-19
The Covid-19 pandemic has had enormous effects on health, wellbeing and economies worldwide. Governments have responded with rapid and sometimes radical public health interventions. As nations grapple with the question of how to regain normality without unnecessarily endangering lives or healthcare systems, some scientists have argued for policies to encourage or compel use of face coverings in community (non-clinical) settings, despite acknowledged gaps in the evidence base for the effectiveness of such a measure. This commentary has two objectives. First, in the face of strong arguments that face coverings are a commonsense intervention, with negligible downsides, that can only do good, we make the case for caution in changing policy. Many seemingly benign public health interventions have the potential to cause harm, and that harm is often socially differentiated. We present five arguments for caution in policy change. Second, we reflect on the wider implications of the increasingly overt approaches to policy advocacy taken by some scientists. Drawing from the theory of post-normal science, we argue that the science-policy interface in the case of face coverings has taken a surprisingly traditional form, falling short of interdisciplinary integration and failing to incorporate insights of the full range of relevant experts and affected stakeholders. We sketch a vision for an alternative, more mature, relationship between science and society that accepts uncertainty, embraces deliberation, and rises to the challenge of developing knowledge to improve public health
Two unusual silicoflagellate double skeletons
A study of silicoflagellate double skeletons revealed two unusual doublets that are illustrated and discussed here. One of these comprises two ten-sided Octactis skeletons that appear to form a doublet, but both in the same (apical) orientation. The other specimen is a double skeleton of Dictyocha
that is slightly disarticulated, with a third, less robust skeleton in between. These unusual double skeletons suggest that there is much more to be learned about the formation of silicoflagellate skeletons and the reproductive processes in this protist grou
Reduction of trimethylamine N-oxide to trimethylamine by the human gut microbiota: supporting evidence for ‘metabolic retroversion’
Dietary sources of methylamines such as choline, trimethylamine (TMA), trimethylamine N-oxide (TMAO), phosphatidylcholine (PC) and carnitine are present in a number of foodstuffs, including meat, fish, nuts and eggs. It is recognized that the gut microbiota is able to convert choline to TMA in a fermentation-like process. Similarly, PC and carnitine are converted to TMA by the gut microbiota. It has been suggested that TMAO is subject to ‘metabolic retroversion’ in the gut (i.e. it is reduced to TMA by the gut microbiota, with this TMA being oxidized to produce TMAO in the liver). Sixty-six strains of human faecal and caecal bacteria were screened on solid and liquid media for their ability to utilize trimethylamine N-oxide (TMAO), with metabolites in spent media profiled by Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy. Enterobacteriaceae produced mostly TMA from TMAO, with caecal/small intestinal isolates of Escherichia coli producing more TMA than their faecal counterparts. Lactic acid bacteria (enterococci, streptococci, bifidobacteria) produced increased amounts of lactate when grown in the presence of TMAO, but did not produce large amounts of TMA from TMAO. The presence of TMAO in media increased the growth rate of Enterobacteriaceae; while it did not affect the growth rate of lactic acid bacteria, TMAO increased the biomass of these bacteria. The positive influence of TMAO on Enterobacteriaceae was confirmed in anaerobic, stirred, pH-controlled batch culture fermentation systems inoculated with human faeces, where this was the only bacterial population whose growth was significantly stimulated by the presence of TMAO in the medium. We hypothesize that dietary TMAO is used as an alternative electron acceptor by the gut microbiota in the small intestine/proximal colon, and contributes to microbial population dynamics upon its utilization and retroversion to TMA, prior to absorption and secondary conversion to TMAO by hepatic flavin-containing monooxygenases. Our findings support the idea that oral TMAO supplementation is a physiologically-stable microbiota-mediated strategy to deliver TMA at the gut barrier
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