Simple, high-performance type II β-BaB2O4 optical parametric oscillator

A visible /near-IR optical parametric oscillator (OPO) based on type II phase matching in β-BaB2O4 (BBO) is described. Pumped at 355 nm, this OPO covers 410-2500 nm completely with a single set of standard Nd:YAG cavity optics. The output efficiency is >25 %, the linewidth of the OPO is narrower than 1 -2 cm^-1 without the use of gratings or etalons, and the signal-beam divergence is <400 µrad. Three type I BBO doubling crystals are used to extend the tuning range from 208 to 415 nm. Doubling efficiencies as high as 40% are easily obtained. The reasons for the high doubling and overall system efficiency are discussed

Explosive Blast Mild Traumatic Brain Injury

In the recent wars in Iraq and Afghanistan, US military personnel have suffered over 333,000 traumatic brain injuries (TBIs), with over 85% being mild TBI. A variety of improvised munitions, such as improvised explosive devices (IEDs) and improvised rocket assisted mortars (IRAMs), have resulted in the explosive blast-induced TBI (bTBI). Due to its prevalence, TBI has been referred to as the signature wound of US warfighters in Afghanistan and Iraq. Explosive blast produces damage to the brain by creating a dynamic environment in forms of overpressure shock wave, heat impulse, blast-propelled projectiles, and debris, whose impact can cause complex injuries in the brain and other visceral organ systems, such as lung and bowel. Mechanisms of bTBI incorporate all forms of TBI such as falls, motor vehicle accidents, and coup-contrecoup injury. Some of the unique aspects of bTBI include the rate at which the injury occurs, the differential pressure load on and within the tissue, and the pressure-loaded tissue response. Mild bTBI is the most problematic injury within the US military in terms of number of warfighters affected and recognition of the injury. The pathobiology of mild bTBI is not fully understood. Here, we review mild bTBI injury, symptomology, and diagnosis. Finally, multi-modality testing is discussed, including functional, structural, and evidence-based evaluation with an intention to describe and diagnose mild bTBI affecting the US warfighter

Low-threshold BBO OPO with cylindrical focusing

The design of a BBO OPO cavity based on cylindrical focusing of the pump beam in the insensitive plane of the non-linear crystal is presented and characterized. A variety of beam sizes in the sensitive plane of the BBO crystal are investigated, and in all cases this cavity design is found to significantly lower the operational threshold pulse energy of 355 nm pumped type I BBO OPOs. With optimal beam focussing parameters, the measured threshold intensity of 45 MW/cm^2 is similar to that of conventional OPOs, but the threshold pulse energy of 0.4 mJ is some twenty times lower than that found in circularly symmetric pump beams. Pump pulse energies in this range can now be routinely achieved with diode-pumped Q-switched lasers, and the combination of these sources with cylindrically-focussed OPO cavities should result in a new class of all-solid-state high repetition rate and high average power non-linear light sources that can be tuned over the entire visible wavelength region

Joint singing voice separation and F0 estimation with deep U-net architectures

Vocal source separation and fundamental frequency estimation in music are tightly related tasks. The outputs of vocal source separation systems have previously been used as inputs to vocal fundamental frequency estimation systems; conversely, vocal fundamental frequency has been used as side information to improve vocal source separation. In this paper, we propose several different approaches for jointly separating vocals and estimating fundamental frequency. We show that joint learning is advantageous for these tasks, and that a stacked architecture which first performs vocal separation outperforms the other configurations considered. Furthermore, the best joint model achieves state-of-the-art results for vocal-f0 estimation on the iKala dataset. Finally, we highlight the importance of performing polyphonic, rather than monophonic vocal-f0 estimation for many real-world cases

Multicrystal harmonic generator compensates for thermally induced phase mismatch

We use computer simulation to illustrate how thermally induced phase mismatch affect deep UV harmonic generation. A multicrystal harmonic generator that compensates for thermally include phase mismatch is then presented. We have tested this multicrystal design with a Nd:YAG lasers 4th harmonic generator based on two pieces of β-BaB_2O_4 crystals, and our results demonstrate that it compensates for the thermally include phase mismatch, effectively increasing the interaction length of nonlinear optical crystals during harmonic generation under high loading

Totally Magic Graphs

A total labeling of a graph with v vertices and e edges is defined as a one-to-one map taking the vertices and edges onto the integers 1, 2, · · · , v+e. Such a labeling is vertex magic if the sum of the label on a vertex and the labels on its incident edges is a constant independent of the choice of vertex, and edge magic if the sum of an edge label and the labels of the endpoints of the edge is constant. In this paper we examine graphs possessing a labeling that is simultaneously vertex magic and edge magic. Such graphs appear to be rare

Common Data Elements for Traumatic Brain Injury: Recommendations From the Biospecimens and Biomarkers Working Group

Recent advances in genomics, proteomics, and biotechnology have provided unprecedented opportunities for translational research and personalized medicine. Human biospecimens and biofluids represent an important resource from which molecular data can be generated to detect and classify injury and to identify molecular mechanisms and therapeutic targets. To date, there has been considerable variability in biospecimen and biofluid collection, storage, and processing in traumatic brain injury (TBI) studies. To realize the full potential of this important resource, standardization and adoption of best practice guidelines are required to insure the quality and consistency of these specimens. The aim of the Biospecimens and Biomarkers Working Group was to provide recommendations for core data elements for TBI research and develop best practice guidelines to standardize the quality and accessibility of these specimens. Consensus recommendations were developed through interactions with focus groups and input from stakeholders participating in the interagency workshop on Standardization of Data Collection in TBI and Psychological Health held in Washington, DC, in March 2009. With the adoption of these standards and best practices, future investigators will be able to obtain data across multiple studies with reduced costs and effort and accelerate the progress of genomic, proteomic, and metabolomic research in TBI

A case of acute myeloid leukemia with promyelocytic features characterized by expression of a novel RARG-CPSF6 fusion

Key Points Novel RARG-CPSF6 fusion in an AML case with promyelocytic features and no evidence of PML-RARA or X-RARA fusion. Gene fusions involving RARG can initiate AML with promyelocytic morphological features.</jats:p

Low-threshold BBO OPO with cylindrical focusing

The design of a BBO OPO cavity based on cylindrical focusing of the pump beam in the insensitive plane of the non-linear crystal is presented and characterized. A variety of beam sizes in the sensitive plane of the BBO crystal are investigated, and in all cases this cavity design is found to significantly lower the operational threshold pulse energy of 355 nm pumped type I BBO OPOs. With optimal beam focussing parameters, the measured threshold intensity of 45 MW/cm^2 is similar to that of conventional OPOs, but the threshold pulse energy of 0.4 mJ is some twenty times lower than that found in circularly symmetric pump beams. Pump pulse energies in this range can now be routinely achieved with diode-pumped Q-switched lasers, and the combination of these sources with cylindrically-focussed OPO cavities should result in a new class of all-solid-state high repetition rate and high average power non-linear light sources that can be tuned over the entire visible wavelength region