Image correlation and sampling study

The development of analytical approaches for solving image correlation and image sampling of multispectral data is discussed. Relevant multispectral image statistics which are applicable to image correlation and sampling are identified. The general image statistics include intensity mean, variance, amplitude histogram, power spectral density function, and autocorrelation function. The translation problem associated with digital image registration and the analytical means for comparing commonly used correlation techniques are considered. General expressions for determining the reconstruction error for specific image sampling strategies are developed

Herding Cats? Management and University Performance

Using a tried and tested measure of management practices that has been shown to predict firm performance, we survey nearly 250 departments across 100+ UK universities. We find large differences in management scores across universities and that departments in older, research-intensive universities score higher than departments in newer, more teaching-oriented universities. We also find that management matters in universities. The scores, particularly with respect to provision of incentives for staff recruitment, retention and promotion are correlated with both teaching and research performance conditional on resources and past performance. Moreover, this relationship holds for all universities, not just research-intensive ones

Absorption coefficient dependent non-linear properties of thin film luminescent solar concentrators

This research article studied absorption coefficient dependent losses and efficiency of thin film luminescent solar concentrator (LSC). The optimum absorption coefficient was determined by fabricating red dye doped thin film LSCs with varying absorption coefficients of 24–202 cm-1. The optical, electrical, and ray-trace model predicted results were compared to establish the optimum absorption coefficient for fabricated thin film LSCs. The optical and electrical efficiencies of thin film LSCs are a function of absorption coefficient; follow linearly at lower values, gradually becoming non- linear at higher values of absorption coefficient which restricts the overall efficiency. The multi layered ray–trace model predicted results deviated from the experimental results at high absorption coefficient. Non-linearity was introduced by losses mechanism of re-absorption, resonant energy transfer (RET), and scattering in thin film LSCs. Re-absorption losses were found to be dependent on optical path-length and absorption coefficient of thin film. They were identified and quantified through locally collected emission and optical path-length in thin film LSCs. Re-absorption losses caused a red shift in emission peak by ≈ 20 nm as the absorption coefficient increased from 24 to 202 cm-1. RET decreased fluorescence life time of dye from 5 ns to 2 ns for the absorption coefficient increased from 24–202 cm-1. These absorption coefficient dependent losses limit the optical and electrical efficiency of thin film LSC devices, and compared with bulk LSC

High temperature superconductors as a technological discontinuity in the power cable industry

The advent of superconductivity above 77 K represents to the power cable industry a technological discontinuity analogous to that seen in the copper telecommunications industry by the arrival of optical fibers. This phenomenon is discussed along with technical criteria and performance targets needed for high temperature superconducting wire to have an economic impact in transmission cables

CHEM2D-OPP: A new linearized gas-phase ozone photochemistry parameterization for high-altitude NWP and climate models

The new CHEM2D-Ozone Photochemistry Parameterization (CHEM2D-OPP) for high-altitude numerical weather prediction (NWP) systems and climate models specifies the net ozone photochemical tendency and its sensitivity to changes in ozone mixing ratio, temperature and overhead ozone column based on calculations from the CHEM2D interactive middle atmospheric photochemical transport model. We evaluate CHEM2D-OPP performance using both short-term (6-day) and long-term (1-year) stratospheric ozone simulations with the prototype high-altitude NOGAPS-ALPHA forecast model. An inter-comparison of NOGAPS-ALPHA 6-day ozone hindcasts for 7 February 2005 with ozone photochemistry parameterizations currently used in operational NWP systems shows that CHEM2D-OPP yields the best overall agreement with both individual Aura Microwave Limb Sounder ozone profile measurements and independent hemispheric (10°–90° N) ozone analysis fields. A 1-year free-running NOGAPS-ALPHA simulation using CHEM2D-OPP produces a realistic seasonal cycle in zonal mean ozone throughout the stratosphere. We find that the combination of a model cold temperature bias at high latitudes in winter and a warm bias in the CHEM2D-OPP temperature climatology can degrade the performance of the linearized ozone photochemistry parameterization over seasonal time scales despite the fact that the parameterized temperature dependence is weak in these regions

Dynamics of Rydberg States of Nitric Oxide Probed By Two-Color Resonant Four-Wave Mixing Spectroscopy

Two-color resonant four-wave mixing (TC-RFWM) spectroscopy has been used to probe highly excited v = 0 and v = 1 Rydberg states of nitric oxide. Transitions to n = 16-30, v = 0, Rydberg states, and the 8p, 9p, 7f, 8f, 8s, and 9s, v = 1 Rydberg states from the A (2)Sigma(+), v\u27 = 0 and 1 states have been recorded. The decay rate of the 8p and 9p, v = 1 states has been extracted from the observed line profiles by using a recently developed model for the excitation of quasibound resonances in TC-RFWM spectroscopy. Transitions from the A (2)Sigma(+), v\u27 = 1 state to the X (2)Pi(3/2), v = 10 state have also been observed, allowing an absolute calibration of the TC-RFWM signal intensity. This calibration is used to determine an excited-state absorption cross section for the 9p, v = 1 Rydberg state. (C) 1998 American Institute of Physics. [S0021-9606(98)01625-0]

Ecological Effects of Fear: How Spatiotemporal Heterogeneity in Predation Risk Influences Mule Deer Access to Forage in a Sky‐Island System

Forage availability and predation risk interact to affect habitat use of ungulates across many biomes. Within sky‐island habitats of the Mojave Desert, increased availability of diverse forage and cover may provide ungulates with unique opportunities to extend nutrient uptake and/or to mitigate predation risk. We addressed whether habitat use and foraging patterns of female mule deer (Odocoileus hemionus) responded to normalized difference vegetation index (NDVI), NDVI rate of change (green‐up), or the occurrence of cougars (Puma concolor). Female mule deer used available green‐up primarily in spring, although growing vegetation was available during other seasons. Mule deer and cougar shared similar habitat all year, and our models indicated cougars had a consistent, negative effect on mule deer access to growing vegetation, particularly in summer when cougar occurrence became concentrated at higher elevations. A seemingly late parturition date coincided with diminishing NDVI during the lactation period. Sky‐island populations, rarely studied, provide the opportunity to determine how mule deer respond to growing foliage along steep elevation and vegetation gradients when trapped with their predators and seasonally limited by aridity. Our findings indicate that fear of predation may restrict access to the forage resources found in sky islands

Risks and benefits HIV preexposure prophylaxis with tenofovir/emtricitabine in an older male with comorbidities

Renal toxicity in a 73 year old man using tenofovir/emtricitabine (TDF/FTC) as pre-exposure prophylaxis (PrEP) is described. Reduced renal reserve, a higher exposure to co-medications and co-morbidities can present a challenge when assessing the risks and benefits of tenofovir based PrEP in the ageing population