The role of the adrenal gland in the survival of white rats subjected to the parotid toxin of the toad, Bufo marinus

Six groups of white labor atory rats were utilized in this experiment. A sham-operated group and an adrenalectomized group were used as controls. Four other groups were adrenalectomized and given replacement therapy of cortisone, deoxycorticosterone acetate, epinephrine, and norepinephrine. All groups were then given injections of toad toxin from the parotid glands of Bufo marinus. Their heart and breathing rates were recorded for 60 minutes. All of the untreated adrenalectomized rats showed altered heart and breathing rates and were killed by the toxin. Cortisone and nor ­ epinephrine aided the adrenalectomiz ed rats to survive. but cortisone was the more effective of the two

Probing Exciton Localization in Single-Walled Carbon Nanotubes Using High-Resolution Near-Field Microscopy

We observe localization of excitons in semiconducting single-walled carbon nanotubes at room temperature using high-resolution near-field photoluminescence (PL) microscopy. Localization is the result of spatially confined exciton energy minima with depths of more than 15 meV connected to lateral energy gradients exceeding 2 meV/nm as evidenced by energy-resolved PL imaging. Simulations of exciton diffusion in the presence of energy variations support this interpretation predicting strongly enhanced PL at local energy minima

Trends in alcohol-related admissions to hospital by age, sex and socioeconomic deprivation in England, 2002/03 to 2013/14

List of conditions by outcome measure. (DOCX 21 kb

Defect Induced Photoluminescence from Dark Excitonic States in Individual Single-Walled Carbon Nanotubes

We show that new low-energy photoluminescence (PL) bands can be created in semiconducting single-walled carbon nanotubes by intense pulsed excitation. The new bands are attributed to PL from different nominally dark excitons that are "brightened" due to defect-induced mixing of states with different parity and/or spin. Time-resolved PL studies on single nanotubes reveal a significant reduction of the bright exciton lifetime upon brightening of the dark excitons. The lowest energy dark state has longer lifetimes and is not in thermal equilibrium with the bright state.Comment: 4 pages, 3 figure

The Linear-Size Evolution of Classical Double Radio Sources

Recent investigations of how the median size of extragalactic radio sources change with redshift have produced inconsistent results. Eales compared the radio and optical properties of a bright 3C and faint 6C sample and concluded that $D\propto(1+z)^{-1.1\pm0.5}$ ($\Omega_0 = 0$), with $D$ being the median size of the radio sources at a given epoch and z the redshift. Oort, Katgert, and Windhorst, on the other hand, from a comparison of the properties of a number of radio samples, found much stronger evolution, with $D\propto(1+z)^{-3.3 \pm0.5}$. In this paper we attempt to resolve the difference. We have repeated the analysis of Eales using the virtually complete redshift information that now exists for the 6C sample. Confining our analysis to FR2 sources, which we argue is the best-understood class of radio sources and the least likely to be affected by selection effects, we find $D\propto(1+z)^{-1.2\pm0.5}$ ($\Omega_0 = 0$) and $D\propto(1+z)^{-1.7\pm0.4}$ ($\Omega_0 = 1$). Our complete redshift information allows us to gain insight into our result by plotting a radio luminosity-size (P-D) diagram for the 6C sample. The most obvious difference between the 3C and 6C P-D diagrams is the clump of sources in the 6C diagram at $D\sim 100 kpc, P_{151}\sim 5x10^{27} WHz^{-1}sr^{-1}$. These clump sources have similar sizes to the emission-line regions found around high-redshift radio galaxies, suggesting that the presence of dense line-emitting gas around high-redshift radio galaxies is responsible for the size evolution. We show that this explanation can quantitatively explain the observed size evolution, as long as there is either little X-ray emitting gas around these objects or, if there is, it is distributed in a similar way to the emission-line gas: highly anisotropic and inhomogeneous.Comment: compressed and uuencoded postscript file. 33 pages including 5 figures (441951 bytes). Accepted for publication in September Ap

The Starburst Nature of Lyman-Break Galaxies: Testing UV Extinction with X-rays

We derive the bolometric to X-ray correlation for a local sample of normal and starburst galaxies and use it, in combination with several UV reddening schemes, to predict the 2--8 keV X-ray luminosity for a sample of 24 Lyman-break galaxies in the HDF/CDF-N. We find that the mean X-ray luminosity, as predicted from the Meurer UV reddening relation for starburst galaxies, agrees extremely well with the Brandt stacking analysis. This provides additional evidence that Lyman-break galaxies can be considered as scaled-up local starbursts and that the locally derived starburst UV reddening relation may be a reasonable tool for estimating the UV extinction at high redshift. Our analysis shows that the Lyman-break sample can not have far-IR to far-UV flux ratios similar to nearby ULIGs, as this would predict a mean X-ray luminosity 100 times larger than observed, as well as far-IR luminosities large enough to be detected in the sub-mm. We calculate the UV reddening expected from the Calzetti effective starburst attenuation curve and the radiative transfer models of Witt & Gordon for low metallicity dust in a shell geometry with homogeneous or clumpy dust distributions and find that all are consistent with the observed X-ray emission. Finally, we show that the mean X-ray luminosity of the sample would be under predicted by a factor of 6 if the the far-UV is unattenuated by dust.Comment: 7 pages, 3 figures. Accepted for publication in A

Seasonal patterns of carbonate diagenesis in nearshore terrigenous muds: Relation to spring phytoplankton bloom and temperature

Pore water saturation state with respect to calcite and aragonite minerals in Long Island Sound sediments fluctuates from saturated and near saturated conditions during late fall, to undersaturated during winter, before slowly changing to supersaturated conditions during late spring. Undersaturation occurs during cold, winter periods when lower rates of ΣCO2 production (low rates of heterotrophic metabolism) and oxidation of reduced minerals such as FeS lower calcium carbonate saturation states. Direct evidence that dissolution of both calcites and aragonite are occurring during this season comes from the simultaneous increases in excess pore water carbonate dissolution products Ca2+, F-, and Sr2+ during periods of pore water undersaturation. Higher ΣCO2 production rates during warmer periods cause the CO32- concentration to become supersaturated for both calcite and aragonite. ΣCO2 production is controlled by both temperature and substrate availability so that benthic deposition of organic matter produced during the spring bloom accelerates the seasonal progression of pore waters to supersaturation. These patterns control carbonate dynamics in temperate, nearshore regions, and result in a regularly observed, yearly cycling of calcium carbonate dominated by alternating periods of net dissolution and net precipitation

Early diagenesis of calcium carbonate in Long Island Sound sediments: Benthic fluxes of Ca2+ and minor elements during seasonal periods of net dissolution

The present study confirms the quantitative significance of carbonate dissolution for associated major and minor element solute fluxes in shelf deposits of temperate regions. Multiple measurement techniques all demonstrate that net dissolution of CaCO3 dominates during winter in Long Island Sound sediments and results in large fluxes of Ca2+, Sr2+, and F- out of the seafloor. Ca2+ fluxes averaged from 4 independent methods range from ~5 to ~13 mmol m-2 d-1 with highest flux occurring when surface deposits are most undersaturated with respect to common biogenic carbonates. A significant proportion of dissolution, 40-100%, results from oxidation of reduced metabolites such as FeS, NH+4, and Mn2+. Results suggest that 90% of the CaCO3 precipitated each year is dissolved, equivalent to a loss of ~90-190 g CaCO3 m-2 yr-1. Given the general similarity between Long Island Sound and other muddy coastal estuaries along the eastern coast of North America and elsewhere (e.g. Chesapeake Bay, Delaware Bay, Narragansett Bay, Buzzards Bay, Casco Bay), these relative flux measurements are likely to be indicative of much larger temperate regions