Effect of a weak longitudinal modulation in refractive index on transverse localization of light in 1D disordered waveguide lattices

We report the enhancement of the effect of transverse localization of light (TL) in presence of a weak longitudinal modulation of refractive index in disordered waveguide lattices. In our chosen lattices, tunneling inhibition along length favors to achieve the diffraction-free propagation along with the simultaneous presence of transverse disorder. Results will be useful to tune the threshold value of disorder to achieve localized light.Comment: 4 pages. arXiv admin note: text overlap with arXiv:1204.614

Observation of topologically protected helical edge modes in Kagome elastic plates

The investigation of topologically protected waves in classical media has opened unique opportunities to achieve exotic properties like one-way phonon transport, protection from backscattering and immunity to imperfections. Contrary to acoustic and electromagnetic domains, their observation in elastic solids has so far been elusive due to the presence of both shear and longitudinal modes and their modal conversion at interfaces and free surfaces. Here we report the experimental observation of topologically protected helical edge waves in elastic media. The considered structure consists of an elastic plate patterned according to a Kagome architecture with an accidental degeneracy of two Dirac cones induced by drilling through holes. The careful breaking of symmetries couples the corresponding elastic modes which effectively emulates spin orbital coupling in the quantum spin Hall effect. The results shed light on the topological properties of the proposed plate waveguide and opens avenues for the practical realization of compact, passive and cost-effective elastic topological waveguides

Effects of vitamins on thyroid and suprarenals

I. EFFECTS OF VITAMINS A AND B ON THYROID AND SUPRARENALS: 1. vitamin A containing diet affects the thyroid similarly to thyroid feeding in small doses, causing inactivity whereas deficiency leads to increased activity on the part of the gland. 2. A resting gland can exert its detoxicating function more than an actively secreting one. This is why vitamin A-fed animals can resist toxins better than the deficient ones. 3. vitamin A acts specifically against Acetonitril like thyroid extract, as is shown by an increased number of phagocytic cells in the gland. The gland is kept in a resting phase so that it can counteract toxins. But when the glands become exhausted by active secretion under the influence of toxin, death takes place. 4. The growth promoting property of the vitamin A may be explained by diminished metabolism caused by producing the resting phase of the gland. 5. The growth promoting nature of vitamin B may be also explained by the diminished metabolism it causes. 6. The deficiency of vitamin B caused more increased secretion and ultimately hyperplasia of the thyroid. 7. vitamin E. is not antitoxic. 8. There is a striking similarity between the effects of vitamins A and B upon the thyroid gland (with the exception of the specific action of the vitamin A in resisting toxins). 9. vitamin A or B deficiency alone cannot cause a complete absence of lipoid content of the cortex of the suprarenal gland. 10. Adrenaline content of the suprarenals is increased by vitamin A deficiency, whereas vitamin B deficiency produces a smaller amount than normal. 11. vitamin B deficiency ultimately leads to an acute insufficiency of the medulla of the suprarenals.II. EFFECTS OF VITAMIN C ON THYROID AND SUPRARENALS: 1. Deficiency of vitamin C leads to an increase in the amount of secretion by the thyroid. °Thus the antiscorbubic factor has an action on the thyroid similar to but less in amount than vitamins A and B. 2. vitamin C like the other water soluble factor B is not antitoxic to acetonitril. 3. Adrenaline content of the suprarenals is diminished by a deficiency of vitamin C: in this respect it resembles vitamin B. 4. vitamin C deficiency does not lead to any appreciable change in the lipoid content of the suprarenal cortex.III. EFFECTS OF VITAMIN D ON THYROID AND SUPRARENALS: 1. Vitamin D behaves towards the thyroid exactly as vitamins A,B and C. It promotes a resting condition of the gland and in this respect, substances like cod liver oil and irradiated milk which contain the antirachitic factor, or ultra violet rays which produce it, contribute towards the resting phase, proportional to the amount of the antirachitic substance they contain or are capable of producing. Deficiency of vitamin D leads to an actively secreting condition of the gland. 2. vitamin D, although it is a fat soluble factor and is almost always closely associated with vitamin A, is not antitoxic to acetonitril. 3. deficiency of vitamin D leads to a slight diminution in the adrenaline content of the suprarenal glands. 4. ultra violet radiation leads to a scanty amount of adrenaline in the medulla of the suprarenals. This effect is probably due to the direct effect of the rays rather than to the chemical substance vitamin D, which is produced under their influence. 5. vitamin D deficiency alone does not lead to any appreciable difference in the lipoid content of the cortex of the suprarenal glands