An AGN Sample with High X-ray-to-optical Flux Ratio from RASS II.Optical Emission Line Properties of Seyfert 1 Type AGN

This work studies the optical emission line properties of a sample of 155 low-redshift bright X-ray selected ROSAT Seyfert~1 type AGN for which adequate signal-to-noise ratio spectroscopic observations are available. We measured emission line properties by performing multi-component fits to the emission line profiles, covering the effect of blended iron emission. We also obtained continuum parameters, including 250eV X-ray luminosities derived from the ROSAT database. In addition, the measured properties are gathered for a correlation analysis, which confirms the well-known relations between the strengths of Fe~II, [O III] emission and the X-ray slope. We also detect striking correlations between H$\beta$ redshift (or blueshift), flux ratios of Fe `II to H$\beta$ broad component and [O III] to H$\beta$ narrow component. These trends are most likely driven by the Eddington ratio.Comment: ApJ in press, 7 figures include

Contrasting physiological responses of ozone-tolerant Phaseolus vulgaris and Nicotiana tobaccum varieties to ozone and nitric acid.

Ozone (O3) and nitric acid (HNO3) are synthesized by the same atmospheric photochemical processes and are almost always co-pollutants. Effects of O3 on plants have been well-elucidated, yet less is known about the effects of HNO3 on plants. We investigated the physiological effects of experimental O3 and HNO3 fumigation on Phaseolus vulgaris (snap bean) and Nicotiana tobaccum (tobacco) varieties with known sensitivity to O3, but unknown responses to HNO3. Responses were measured as leaf absorptance, aboveground plant biomass, and photosynthetic CO2-response curve parameters. Our results demonstrate that O3 reduced absorptance, stomatal conductance and plant biomass in both species, and maximum photosynthetic rate in P. vulgaris, whereas the main effect of HNO3 was an increase in mesophyll conductance. Overall, the results suggest that HNO3 affects mesophyll conductance through increased nitrogen absorbed by leaves during HNO3 deposition which in turn increases photosynthetic demand for CO2, or that damage to epicuticular waxes on leaves increased diffusion of CO2 to sites of carboxylation

Contrasting physiological responses of ozone-tolerant Phaseolus vulgaris and Nicotiana tobaccum varieties to ozone and nitric acid.

Ozone (O3) and nitric acid (HNO3) are synthesized by the same atmospheric photochemical processes and are almost always co-pollutants. Effects of O3 on plants have been well-elucidated, yet less is known about the effects of HNO3 on plants. We investigated the physiological effects of experimental O3 and HNO3 fumigation on Phaseolus vulgaris (snap bean) and Nicotiana tobaccum (tobacco) varieties with known sensitivity to O3, but unknown responses to HNO3. Responses were measured as leaf absorptance, aboveground plant biomass, and photosynthetic CO2-response curve parameters. Our results demonstrate that O3 reduced absorptance, stomatal conductance and plant biomass in both species, and maximum photosynthetic rate in P. vulgaris, whereas the main effect of HNO3 was an increase in mesophyll conductance. Overall, the results suggest that HNO3 affects mesophyll conductance through increased nitrogen absorbed by leaves during HNO3 deposition which in turn increases photosynthetic demand for CO2, or that damage to epicuticular waxes on leaves increased diffusion of CO2 to sites of carboxylation

Metrology of a Focusing Capillary Using Optical Ptychography

The focusing property of an ellipsoidal monocapillary has been characterized using the ptychography method with a 405 nm laser beam. The recovered wavefront gives a 12.5×10.4μm2 focus. The reconstructed phase profile of the focused beam can be used to estimate the height error of the capillary surface. The obtained height error shows a Gaussian distribution with a standard deviation of 1.3 μm. This approach can be used as a quantitative tool for evaluating the inner functional surfaces of reflective optics, complementary to conventional metrology methods

Plant water status and hydraulic conductance during flowering in the southern California coastal sage shrub Salvia mellifera (Lamiaceae).

Premise of the studyPlant water status during flowering is important for plant reproduction, but the physiology of floral water use is not well understood. We investigated plant water status in relation to leaf and floral physiology in naturally occurring individuals of a semiarid shrub, Salvia mellifera E. Greene.MethodsWe measured stomatal (g(s)) and corolla (g(c)) conductance to water vapor, transpiration from leaves (E(leaf)) and corollas (E(corolla)), leaf-specific hydraulic conductance (K(H)), bulk shoot water potential (Ψ(shoot)), and shoot water content on irrigated and control plants to analyze whether water was limiting to leaf and floral water use.Key resultsExperimental irrigation caused a 203% increase in soil moisture content, a 20% increase in predawn Ψ(shoot), a 29% increase in midday Ψ(shoot), and a 92% increase in K(H). Floral and leaf gas exchange did not respond significantly to water addition, indicating that rates were at seasonal maxima and not limited by water availability. Total daily water use by corollas was ∼20% of total shoot water use. There were no significant differences in total daily shoot water use with water addition. Mean shoot water content (5.07 g) was close to mean daily shoot water use (6.71 g), indicating that the equivalent of total shoot water content turned over every 0.76 d.ConclusionsThese results demonstrate that although irrigation improved whole-plant hydraulic conductance, gas exchange was not limited by water availability. Additionally, the high water use of flowers in this species might limit future flowering and reproductive success during dry years