Projected network performance for next generation aerosol monitoring systems.

Aerosol monitoring for radioactivity is a mature and proven technology. However, by improving key specifications of aerosol monitoring equipment, more samples per day can be collected and analyzed with the same minimum detectable concentrations as current systems. This work models hypothetical releases of 140Ba and 131I over a range of magnitudes corresponding to the inventory produced from the fission of about 100 g to 1 kiloton TNT-equivalent of 235U. The releases occur over an entire year to incorporate the natural variability in atmospheric transport. Sampling equipment located at the 79 locations for radionuclide stations identified in the Comprehensive Nuclear-Test-Ban Treaty (CTBT) for the International Monitoring System are used to determine the detections of the individual releases. Alternative collection schemes in next generation equipment that collect 2, 3, or 4 samples per day, rather than the current 1 sample per day, would result in detections in many more samples at more stations with detections for a given release level. The authors posit that next generation equipment will result in increased network resilience to outages and improved source-location capability for lower yield source releases. The application of dual-detector and coincidence measurements to these systems would significantly boost sensitivity for some isotopes and would further enhance the monitoring capability.

Source term estimation in the presence of nuisance signals.

Many source-term estimation algorithms for atmospheric releases assume the measured concentration data are influenced only by the releases of interest. However, there are situations where identifying a short-term release from an unknown location in the presence of long-term releases from a different location is of interest. One such example is determining if part or all of a typical magnitude concentration of a radioactive isotope in a sampler came from a nuclear explosion, such as the explosion announced by DPRK in 2013, while medical isotope facilities and nuclear power plants were also operating in the region. An estimation algorithm has been developed for the case where a short-duration release is confounded by a long-term nuisance signal associated with an additional release location. The technique is demonstrated using synthetic release data for a hypothetical medical isotope production facility and a hypothetical puff release from a different location. The algorithm successfully determines the location (within 30 km) and time-varying release rate (within a factor of 2) for the medical isotope production facility and the location (within 60 km), time (within 6 h), and release magnitude (within a factor of 4) of the puff release.

Leptin-sensitive sensory nerves innervate white fat.

Leptin, the primary white adipose tissue (WAT) adipokine, is thought to convey lipid reserve information to the brain via the circulation. Because WAT responds to environmental/internal signals in a fat pad-specific (FPS) manner, systemic signals such as leptin would fail to communicate such distinctive information. Saturation of brain leptin transport systems also would fail to convey increased lipid levels beyond that point. WAT possesses sensory innervation exemplified by proven sensory-associated peptides in nerves within the tissue and by viral sensory nerve-specific transneuronal tract tracer, H129 strain of herpes simplex virus 1 labeling of dorsal root ganglia (DRG) pseudounipolar neurons, spinal cord and central sensory circuits. Leptin as a paracrine factor activating WAT sensory innervation could supply the brain with FPS information. Therefore, we tested for and found the presence of the long form of the leptin receptor (Ob-Rb) on DRG pseudounipolar neurons immunohistochemically labeled after injections of Fluorogold, a retrograde tract tracer, into inguinal WAT (IWAT). Intra-IWAT leptin injections (300 ng) significantly elevated IWAT nerve spike rate within 5 min and persisted for at least 30 min. Intra-IWAT leptin injections also induced significant c-Fos immunoreactivity (ir), indicating neural activation across DRG pseudounipolar sensory neurons labeled with Fluorogold IWAT injections. Intraperitoneal leptin injection did not increase c-Fos-ir in DRG or the arcuate nucleus, nor did it increase arcuate signal transducer and activator of transcription 3 phosphorylation-ir. Collectively, these results strongly suggest that endogenous leptin secreted from white adipocytes functions as a paracrine factor to activate spinal sensory nerves innervating the tissue.