Estimating the effect of non-pharmaceutical interventions on US SARS-CoV-2 infections in the first year of the pandemic.

SARS-CoV-2 emerged in late 2019 as a zoonotic infection of humans, and proceeded to cause a worldwide pandemic of historic magnitude. Here, we use a simple epidemiological model and consider the full range of initial estimates from published studies for infection and recovery rates, seasonality, changes in mobility, the effectiveness of masks and the fraction of people wearing them. Monte Carlo simulations are used to simulate the progression of possible pandemics and we show a match for the real progression of the pandemic during 2020 with an R 2 of 0.91. The results show that the combination of masks and changes in mobility avoided approximately 248.3 million (σ = 31.2 million) infections in the US before vaccinations became available.

Propagation of a solitary fission wave.

Reaction-diffusion phenomena are encountered in an astonishing array of natural systems. Under the right conditions, self stabilizing reaction waves can arise that will propagate at constant velocity. Numerical studies have shown that fission waves of this type are also possible and that they exhibit soliton like properties. Here, we derive the conditions required for a solitary fission wave to propagate at constant velocity. The results place strict conditions on the shapes of the flux, diffusive, and reactive profiles that would be required for such a phenomenon to persist, and this condition would apply to other reaction diffusion phenomena as well. Numerical simulations are used to confirm the results and show that solitary fission waves fall into a bistable class of reaction diffusion phenomena.

Compressive optic neuropathy caused by renal osteodystrophy. Case report.

Compressive optic neuropathy with acute or chronic vision loss has been associated with various skull base tumors, aneurysms, Graves disease, trauma, and, less commonly, fibrous dysplasia and osteopetrosis. The authors present a case of acute visual deterioration in a 25-year-old woman who had massive calvarial hypertrophy with optic canal stenosis secondary to renal osteodystrophy (uremic leontiasis ossea [ULO]: bighead disease). Significant visual field restoration was achieved with high-dose corticosteroids followed by optic nerve decompression. This is the first case report of cranial neuropathy associated with ULO.

1H and 13C NMR spectral studies of some 4H-3,1-benzoxazin-4-ones and their 2-acylaminobenzoic acid precursors.

The 1H and 13C NMR spectra of twelve 4H-3,1-benzoxazine-4-ones and of their acylaminobenzoic acid precursors are presented. Differentiation between these two series of compounds is best achieved through the characteristic J(CH) coupling interactions in the high frequency carbonyl region. Some 4H-pyrido[2,3-d][1,3]oxazin-4-ones have also been studied and some earlier literature assignments revised.

Legal standards for an appropriate education in the post-Rowley era.

In 1982 the U.S. Supreme Court held than an appropriate education under the Individuals with Disabilities Education Act was one that was formulated in accordance with the Act's procedures and that conferred some educational benefit on students with disabilities. Initially, the lower court applied this terminology strictly and approved any proposed individualized education program that conferred even minimal educational benefit. However, later courts began to take a more liberal approach and held that the educational program must confer some meaningful benefit. A careful reading of the Supreme Court's 1982 decision indicates that this recent approach is consistent with Congress's and the Court's intent. The Court never intended to establish one test of appropriateness since it recognized that some flexibility was needed to determine what would be appropriate for a diverse population of students with disabilities.