The solvatochromism of fluoresceine and its derivatives was studied in solvents of different Hydrogen Bond Donor (HBD), Hydrogen Bond Acceptor (HBA), Donor Number (DN) and Acceptor Number (AN) by their UV-Vis spectra. Results showed that position, intensity and shape of absorption bands change with type of solvent. These changes can be rationalized by solvatochromic parameters such as ...

H E melanin pigments of mammals fall into two major categories, the T darker pigments or eumelanins and the orange yellow pigments or phaeomelanins. These presumably differ qualitatively although the exact chemistry 01 the melanins is not yet known. The hairs of wild cavies and of the so-called agouti variety of the guinea pig are predominantly eumelanic but have a phaeomelanic subterminal band...

introduction the iran has vast areas of karst landforms due to the relatively high carbonaceous rocks deposited during different geologic eras. karst landforms are noteworthy for investigation from many aspects. the primary importance of these regions is the considerable amount of underground water stored in karst formations. these reserves are favorable, both in quality and quantity, as natura...

OBJECTIVES Evaluate trends from 2011-2015 in electronic cigarette (e-cigarette) use among U.S. adolescents, grades 6-12, including prevalence and associations with past month use of cigarettes and other tobacco products, cigarette smoking intensity, quit attempts, and quit contemplation. METHODS Five consecutive waves from the National Youth Tobacco Survey (N = 101,011) were used to estimate ...

Utilizing only the vertical muon intensity of the Gaisser parameterization of the muon flux at the surface and propagating this energy spectrum underground according to statistical ionization and radiative energy losses, it is possible to calculate the underground muon intensity Crouch curve. In addition, the primary spectral index of the Gaisser parameterization can be adjusted from E to E sim...

The human eye is insensitive to the angular direction of the light e-vector, but several animal species have the ability to discriminate differently polarized lights. How the polarization is detected is often unclear, however. Egg-laying Papilio butterflies have been shown to see false colours when presented with differently polarized lights. Here we asked whether this also holds in foraging bu...

The endocrine control mechanisms for female mammalian aggression have been largely unstudied. Although it has been proposed that androgens may modulate female aggressive behavior in a similar manner to males, very little conclusive evidence exists. Previous work in male marmosets found that post-encounter increases in testosterone (T) were dependent on the intensity of aggression displayed duri...

We examined the effects of dead space loading (DSL) on ventilation (V˙E), neural respiratory drive (EMGdi%max, diaphragm EMG expressed as a % of maximal EMGdi), contractile respiratory muscle effort (Pes,tidal%P(Imax), tidal esophageal pressure swing expressed as a % of maximal inspiratory Pes) and exertional dyspnea intensity ratings in 11 healthy adults with normal spirometry. Subjects comple...