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There is ever growing interest in sensitive detection of short wavelength (SWL) radiation, ultraviolet (UV) and X-rays. We report on our efforts to develop sensitive SWL detectors based on the nanoparticles (NPs) of lanthanide (Ln) doped Cs-Pb-bromide perovskite and oxysulfides that down-convert the spectrum of SWL radiation into visible and near-infrared (NIR) light. The spectrum of this light matches the spectral response of inexpensive and rugged silicon avalanche photo diodes (APDs) and image sensors with an electron gain of >106. Synthesized Eu-doped perovskite NPs demonstrated a down-shifted visible-NIR photoluminescence (PL) response to UV radiation with the spectral peaks attributed to both perovskite matrix and Eu dopant. A scintillating screen made of red nanophosphor Gd2O2S: Eu was used for X-ray see-through imaging of a metal object hidden in an opaque medium. Integration of the nanophosphor with a silicon APD made it possible to detect pulsating X-rays at frequencies of 20 and 40Hz with a signal-to-noise ration of ~5. The results obtained might be used in the field of sensitive detection of SWL radiation. 

Abstract The hot deserts of the southwestern United States are experiencing increased frequency, severity, and duration of drought due to anthropogenic climate change. Plant communities in these deserts differ in composition, specifically the abundance of annual and perennial species, which could differentiate responses among these ecosystems to drought. Thus, identifying how these desert plant communities respond to prolonged, severe drought is critical to assess vulnerability to climate change. We measured the response of herbaceous plant communities to 4 years of experimentally imposed severe drought in Chihuahuan, Sonoran, and Mojave Desert sites in the southwestern US.We imposed year‐round passive rain exclusion treatments with a 66% reduction in ambient rainfall for 4 years at two sites in each of the three US hot deserts. We measured plant species composition and abundance in treatment and control plots during the peak growing season.Vegetative cover increased with seasonal precipitation at all six sites. Species richness and evenness varied in response to drought across all sites over the duration of the experiment. At three of the six sites, species richness increased with seasonal precipitation and at three sites species evenness decreased with seasonal precipitation.In general, we found that community structure was linked to seasonal precipitation more so than cumulative drought in these herbaceous communities of southwestern US deserts, and that these desert communities are highly resilient following prolonged, extreme drought. 

Using socially assistive robots (SARs) as specialized companions for those living with depression to manage symptoms provides a unique opportunity for exploration of robotic systems as comfort objects. Moreover, the robotic components allow for specialized behavioral responses to particular stimuli, as preferred by the user. We have conducted semi-structured interviews with 10 participants about the zoomorphic robot’s TherabotTM desired behaviors and focus groups with five additional participants regarding the preferred sensors within the TherabotTM system. In this paper, using the data from interviews and focus groups, we explore SAR input and output for depression management. While participants overall expected the robot to respond in much similar ways as a well-trained service animal, they expressed interest in the robot understanding unique information about the environment and the user, such as when the user might need interaction.