purpose : to determine the association between astigmatism and spherical refractive error in a clinical population methods : in this cross-sectional study, 2,000 patients who presented to our optometry clinic were enrolled. all were tested for objective refraction with a nidek ar-310a auto refractometer, and non-cycloplegic refraction. for those under 15 years of age, cycloplegic refraction was...

Glucocorticoid concentrations are a balance between production under the negative feedback control and diurnal rhythm of the hypothalamic-pituitary-adrenal (HPA) axis and peripheral metabolism, for example by the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which catalyses the reduction of inactive cortisone (11-dehydrocorticosterone (11-DHC) in mice) to cortisol (corticosterone i...

A long cylindrical body of circular cross-section and homogeneous density may float in all orientations around the cylinder axis. It is shown that there are also bodies of non-circular cross-sections which may float in any direction. Apart from those found by Auerbach for ρ = 1/2 there are one-parameter families of cross-sections for ρ 6= 1/2 which have a p-fold rotation axis. For given p they ...

Utilizing an elastic polymer, we design and experimentally demonstrate a four-fold symmetric flexible metamaterial operating at terahertz frequencies. The fabricated metamaterials exhibit good stretchability and recoverability. Two independent resonances can be observed when the structure is probed with linearly polarized terahertz waves in two orthogonal axes. Applying a stretching force along...

My G4G8 exchange item is a screw-together cube made of two identically shaped nylon parts, one dyed red and one dyed yellow. It can be seen as a cube sliced by the propeller of an airplane flying through it. Formally, it is cube which has been split along a helicoid surface whose axis is aligned with a two-fold axis of the cube, i.e. passing from one edge midpoint to the opposite edge midpoint....

A long cylindrical body of circular cross-section and homogeneous density may float in all orientations around the cylinder axis. It is shown that there are also bodies of non-circular cross-sections which may float in any direction. Apart from those found by Auerbach for ρ = 1/2 there are one-parameter families of cross-sections for ρ = 1/2 which have a p-fold rotation axis. For given p they e...

Predicting suicide is difficult due to the low base rate, even in high-risk groups, and the multi-causal nature of suicidal behavior. Clinical predictors have shown low specificity. Retrospective and cross-sectional studies have identified a number of biologic anomalies associated with suicide and suicide attempt. Prospective studies provide estimates of the predictive utility of biologic measu...

Powder neutron diffraction studies were performed on three icosahedral alloys of the aluminum manganese system containing 27, 30. and 34 weight percent manganese. All peaks were found at the angles consistent with the icosahedral indexing with a six-dimensional cubic lattice parameter of approximately 0.65 nm that decreased with increasing Mn content. The relative intensities differ significant...

Biological responses often obey Weber's law, according to which the magnitude of the response depends only on the fold change in the external input. In this study, we demonstrate that a system involving a simple autocatalytic reaction shows such a response when a chemical is slowly synthesized by the reaction from a faster influx process. We also show that an autocatalytic reaction process occu...

The well-known third list homomorphism theorem states that if a function h is both an instance of foldr and foldl , it is a list homomorphism. Plenty of previous works devoted to constructing list homomorphisms, however, overlook the fact that proving h is both a foldr and a foldl is often the hardest part which, once done, already provides a useful hint about what the resulting list homomorphi...