Scytonemin-imine, a novel derivative of scytonemin, has been isolated and identified very recently and proposed to serve as a photoprotective biomarker for certain bacteria growing under intense photon flux density. This study predicts theoretically the Raman spectrum of scytonemin-imine by density functional theory calculations and provides comparison of major bands to those of scytonemin, the...

Little Higgs models with T parity contain an attractive dark matter candidate, the heavy photon. We compute the cross section of the heavy photon annihilation into Zphoton pairs, which turns out to be substantially higher than the previously computed cross section for the two photon final state. Unfortunately, even with this enhancement, the monochromatic photon flux from galactic heavy photon ...

An X-ray micro/nanodiffraction technique that allows structural characterization of individual nanomaterials has been developed at an insertion-device beamline of the Advanced Photon Source. Using the extremely high brightness of the third-generation synchrotron radiation source and advanced high-resolution high-energy zone-plate focusing optics, X-rays of energies from 6 to 12 keV have been fo...

Cortical blood flow at the level of individual capillaries and the coupling of neuronal activity to flow in capillaries are fundamental aspects of homeostasis in the normal and the diseased brain. To probe the dynamics of blood flow at this level, we used two-photon laser scanning microscopy to image the motion of red blood cells (RBCs) in individual capillaries that lie as far as 600 micromete...

A novel photon flux monitor has been designed and tested for use at the Duke University High Intensity Gamma Source, where the photon beam produced is essentially mono-energetic but it is not tagged. Direct counting of the number of photons using a high-efficiency detector is not possible because of the high photon fluxes expected. Therefore, a direct counting detector with a low, accurately kn...

The interaction between phytochrome photoequilibrium (phi) and photon flux in the photoregulation of anthocyanin production under prolonged irradiation was studied in seedlings of Brassica oleracea L. and Lycopersicon esculentum Mill. In cabbage, anthocyanin production increases with decreasing phi, reaching a maximum at the lowest value (phi = 0.13) used in this study; in tomato, the extent of...

introduction: osteoporosis is a bone disease in which there is a reduction in the amount of bone mineral content leading to an increase in the risk of bone fractures. the affected individuals not only have to go through lots of pain and suffering but this disease also results in high economic costs to the society due to a large number of fractures.  a timely and accurate diagnosis of this disea...

Among the plant factors, canopy geometry plays a crucial role in deciding the driving force for leaf biological processes since it modulates canopy interception of short-term radiation fluxes and it controls their distributions throughout the foliage (Monteith and Unsworth, 1990; Jones, 1992). In particular, it is recognized the biological role of PhAR (400-700 nm waveband) in driving the photo...

The paradigm of the neutralino dark matter predicts that the first gravitationally bound objects are earth-mass sized microhaloes, which would emit annihilation gamma-rays. Here we show that, though the flux from individual nearest microhaloes is extremely difficult to detect, meaningful constraints on their survival probability and internal density profile can be set by requiring that the gala...

Simulation of gamma and hadron showers in the energy range 100GeV- 25TeV has been carried out. For a big ideal Cherenkov light array, characteristics of lateral distribution of Cherenkov photon density have been studied. Results from this ideal detector are compared with those simulated for a real TUNKA- like array to investigate experimental potential of using existence of a hump in lateral di...