Initial Performance Analysis of the At-Altitude Radiance Ratio Method for Reflectance Conversion of Hyperspectral Remote Sensing Data.

In remote sensing, the conversion of at-sensor radiance to surface reflectance for each pixel in a scene is an essential component of many analysis tasks. The empirical line method (ELM) is the most used technique among remote sensing practitioners due to its reliability and production of accurate reflectance measurements. However, the at-altitude radiance ratio (AARR), a more recently proposed methodology, is attractive as it allows reflectance conversion to be carried out in real time throughout data collection, does not require calibrated samples of pre-measured reflectance to be placed in scene, and can account for changes in illumination conditions. The benefits of AARR can substantially reduce the level of effort required for collection setup and subsequent data analysis, and provide a means for large-scale automation of remote sensing data collection, even in atypical flight conditions. In this study, an onboard, downwelling irradiance spectrometer integrated onto a small unmanned aircraft system (sUAS) is utilized to characterize the performance of AARR-generated reflectance from hyperspectral radiance data under a variety of challenging illumination conditions. The observed error introduced by AARR is often on par with ELM and acceptable depending on the application requirements and natural variation in the reflectance of the targets of interest. Additionally, a number of radiometric and atmospheric corrections are proposed that could increase the accuracy of the method in future trials, warranting further research.

X-ray Raman scattering for bulk chemical and structural insight into green carbon.

X-ray Raman scattering (XRS) spectroscopy is an emerging inelastic scattering technique which uses hard X-rays to study the X-ray absorption edges of low-Z elements (e.g. C, N, O) in bulk. This study applies XRS spectroscopy to pyrolysis and hydrothermal carbons. These materials are thermochemically-produced carbon from renewable resources and represent a route for the sustainable production of carbon materials for many applications. Results confirm local structural differences between biomass-derived (Oak, Quercus Ilex) pyrolysis and hydrothermal carbon. In comparison with NEXAFS, XRS spectroscopy has been shown to be more resilient to experimental artefacts such as self-absorption. Density functional theory XRS calculations of potential structural sub-units confirm that hydrothermal carbon is a highly disordered carbon material formed principally of furan units linked by the α carbon atoms. Comparison of two pyrolysis temperatures (450 °C and 650 °C) shows the development of an increasingly condensed carbon structure. Based on our results, we have proposed a semi-quantitative route to pyrolysis condensation.

Current smoking is associated with worse cognitive and adaptive functioning in serious mental illness.

OBJECTIVE: Cigarette smoking is highly prevalent among people with bipolar disorder or schizophrenia. Few studies have examined whether smoking history is associated with adaptive functioning among individuals diagnosed with these serious mental illnesses. METHOD: In a large relatively homogenous cohort of patients with either bipolar disorder (n=363) or schizophrenia (n=400), we investigated the association between cigarette smoking status, intensity, and cumulative exposure and performance on a comprehensive battery of neurocognitive, functional capacity, and informant-rated functional measures. The associations were adjusted for variation in sociodemographic indicators, psychopathologic symptoms, and substance use. RESULTS: There was an average of 12 pack years of smoking across the sample. People with schizophrenia reported double the rate of current smoking compared to patients with bipolar disorder. Adjusting for demographic covariates, current smokers had worse composite cognitive functioning and poorer functional outcome than past or never smokers. There were no significant differences between never and past smokers, and these effects were evident in both bipolar disorder and schizophrenia. CONCLUSION: Current smokers with either schizophrenia or bipolar disorder evidence worse cognitive and adaptive functioning functional outcome, even when demographic covariates are considered.