Inter-comparison Of Reflectivity Measurements Between GPM DPR And NEXRAD Radars

This study demonstrates the potential use of the NASA\u27s Global Precipitation Measurement (GPM) Dual-frequency Precipitation Radar (DPR) to examine ground radar (GR) miscalibration and other uncertainty sources (e.g., partial beam blockage). We acquired the GPM Ground Validation System Validation Network reflectivity matchups between the DPR and three GRs (two in Iowa and one in South Dakota) for 2014–2017. We then refined the matching parameters (e.g., time separation) to reduce uncertainty in the matchup samples by analyzing the sensitivity of the matchup statistical properties to changes in these parameters. To reconcile the same observables (i.e., reflectivity) with different observational properties among the space- and ground-based radars, we developed a statistically integrated framework using inter-comparisons of them all with a Monte Carlo simulation. This method verifies the absolute calibration bias estimated from the refined DPR–GR matchups using relative calibration biases between GRs. We found that taking samples with a narrow temporal gap, estimated by actual measurement time of the DPR and GRs, can significantly reduce sample variability. Through inter-comparisons among the DPR and GRs, we observed that reflectivity differences among GRs in a similar environment (e.g., climatology and geography) are likely to be affected primarily by the calibration mismatch. In this case, the inter-comparison results demonstrated good agreement, and we inferred that the differences can be mitigated by calibration bias correction against the DPR. On the other hand, when the disagreement level of the inter-comparison results is significant, the authors found that other factors, such as partial beam blockage even in relatively plain regions, are more dominant than the calibration bias. In fact, the partial beam blockage effects can manifest themselves as a seasonal pattern in the GR inter-comparison results

Cerebrospinal fluid neurofilament light predicts longitudinal diagnostic change in patients with psychiatric and neurodegenerative disorders

OBJECTIVE: People with neuropsychiatric symptoms often experience delay in accurate diagnosis. Although cerebrospinal fluid neurofilament light (CSF NfL) shows promise in distinguishing neurodegenerative disorders (ND) from psychiatric disorders (PSY), its accuracy in a diagnostically challenging cohort longitudinally is unknown. METHODS: We collected longitudinal diagnostic information (mean = 36 months) from patients assessed at a neuropsychiatry service, categorising diagnoses as ND/mild cognitive impairment/other neurological disorders (ND/MCI/other) and PSY. We pre-specified NfL > 582 pg/mL as indicative of ND/MCI/other. RESULTS: Diagnostic category changed from initial to final diagnosis for 23% (49/212) of patients. NfL predicted the final diagnostic category for 92% (22/24) of these and predicted final diagnostic category overall (ND/MCI/other vs. PSY) in 88% (187/212), compared to 77% (163/212) with clinical assessment alone. CONCLUSIONS: CSF NfL improved diagnostic accuracy, with potential to have led to earlier, accurate diagnosis in a real-world setting using a pre-specified cut-off, adding weight to translation of NfL into clinical practice

Magnetic correlations and quantum criticality in the insulating antiferromagnetic, insulating spin liquid, renormalized Fermi liquid, and metallic antiferromagnetic phases of the Mott system V_2O_3

Magnetic correlations in all four phases of pure and doped vanadium sesquioxide V_2O_3 have been examined by magnetic thermal neutron scattering. While the antiferromagnetic insulator can be accounted for by a Heisenberg localized spin model, the long range order in the antiferromagnetic metal is an incommensurate spin-density-wave, resulting from a Fermi surface nesting instability. Spin dynamics in the strongly correlated metal are dominated by spin fluctuations in the Stoner electron-hole continuum. Furthermore, our results in metallic V_2O_3 represent an unprecedentedly complete characterization of the spin fluctuations near a metallic quantum critical point, and provide quantitative support for the SCR theory for itinerant antiferromagnets in the small moment limit. Dynamic magnetic correlations for energy smaller than k_BT in the paramagnetic insulator carry substantial magnetic spectral weight. However, the correlation length extends only to the nearest neighbor distance. The phase transition to the antiferromagnetic insulator introduces a sudden switching of magnetic correlations to a different spatial periodicity which indicates a sudden change in the underlying spin Hamiltonian. To describe this phase transition and also the unusual short range order in the paramagnetic state, it seems necessary to take into account the orbital degrees of freedom associated with the degenerate d-orbitals at the Fermi level in V_2O_3.Comment: Postscript file, 24 pages, 26 figures, 2 tables, accepted by Phys. Rev.

Fabrication of a Highly Sensitive Chemical Sensor Based on ZnO Nanorod Arrays

We report a novel method for fabricating a highly sensitive chemical sensor based on a ZnO nanorod array that is epitaxially grown on a Pt-coated Si substrate, with a top–top electrode configuration. To practically test the device, its O2 and NO2 sensing properties were investigated. The gas sensing properties of this type of device suggest that the approach is promising for the fabrication of sensitive and reliable nanorod chemical sensors

Ultra violet sensors based on nanostructured ZnO spheres in network of nanowires: a novel approach

The ZnO nanostructures consisting of micro spheres in a network of nano wires were synthesized by direct vapor phase method. X-ray Photoelectron Spectroscopy measurements were carried out to understand the chemical nature of the sample. ZnO nanostructures exhibited band edge luminescence at 383 nm. The nanostructure based ZnO thin films were used to fabricate UV sensors. The photoresponse measurements were carried out and the responsivity was measured to be 50 mA W−1. The rise and decay time measurements were also measured

Magnetic Structure of TbFe₃

The magnetic structure of TbFe3 was determined at room temperature and 77 K by powder neutron diffraction. The magnetic structure is essentially that of HoFe3, a colinear ferrimagnetic structure with the Tb moments coupled antiparallel to those of Fe in the basal plane. The three non-equivalent crystallographic Fe sites exhibit different magnetic moments. On the basis of the neutron diffraction data collected above the ordering temperature, it is concluded that no substitution of Tb by Fe occurs

The Potentially Fatal Ogilvie\u27s Syndrome in Lateral Transpsoas Access Surgery: A Multi-Institutional Experience with 2930 Patients.

BACKGROUND: Ogilvie\u27s syndrome (OS) is a relatively uncommon pathology characterized by significant colonic dilation in the absence of mechanical obstruction. If unrecognized and untreated, cecal perforation resulting in a mortality rate of 25%-71% may occur. It is a potentially underdiagnosed condition in the lateral transpsoas approach population because of its uncommon nature and imitation of other well-known pathologies. METHODS: Two thousand nine hundred and thirty patients from 6 separate institutions were retrospectively reviewed since 2007 and screened for OS. All patients underwent a minimum of single-level lateral transpsoas fusion. Diagnostic criteria included signs of a postoperative paralytic ileus combined with abdominal computed tomography showing a cecal diameter greater than 9 cm. Treatment modalities and outcomes were recorded. RESULTS: Eight cases (0.22%) of OS were diagnosed at 6 separate institutions. Most institutions recorded more than 350 lateral access procedures. Four cases were initially diagnosed as a routine postoperative ileus; however, they failed conservative therapy and underwent abdominal CT imaging. Neostigmine treatment was required for 1 patient in the intensive care unit setting, and 3 patients were managed conservatively without complications. Four other patients demonstrated bowel perforation at least 48 hours after surgery and required laparotomy with diversion ileostomy. CONCLUSION: Ogilvie\u27s syndrome is a rare but potentially fatal complication that can mimic a postoperative ileus. It is likely underdiagnosed in the lateral transpsoas approach population because of its uncommon nature and a high index of suspicion should remain. Neostigmine can be administered safely under close observation with immediate and successful outcomes. Patients with perforation require urgent laparotomy and primary repair