Start/stop switches for testing detonation velocity of explosives

Printed-circuit process produces ordnance-initiated start/stop switches. Method is faster and less costly than fabriction by hand, and produces switches of uniform quality

Internal friction peaks observed in explosively deformed polycrystalline Mo, Nb, and Cu

Explosive deformation (50 kbar range) induced, in Cu, Mo and Nb, internal friction peaks identical to those observed after large normal deformation. The variation of the peaks with pressure for Mo and Nb lead to an explanation of these processes in terms of double kink generation in screw and edge dislocations

Microwave Absorption of Surface-State Electrons on Liquid 3^3He

We have investigated the intersubband transitions of surface state electrons (SSE) on liquid $^3$He induced by microwave radiation at temperatures from 1.1 K down to 0.01 K. Above 0.4 K, the transition linewidth is proportional to the density of $^3$He vapor atoms. This proportionality is explained well by Ando's theory, in which the linewidth is determined by the electron - vapor atom scattering. However, the linewidth is larger than the calculation by a factor of 2.1. This discrepancy strongly suggests that the theory underestimates the electron - vapor atom scattering rate. At lower temperatures, the absorption spectrum splits into several peaks. The multiple peak structure is partly attributed to the spatial inhomogeneity of the static holding electric field perpendicular to the electron sheet.Comment: 15 pages, 7 figures, submitted to J. Phys. Soc. Jp

The space physics environment data analysis system (SPEDAS)

With the advent of the Heliophysics/Geospace System Observatory (H/GSO), a complement of multi-spacecraft missions and ground-based observatories to study the space environment, data retrieval, analysis, and visualization of space physics data can be daunting. The Space Physics Environment Data Analysis System (SPEDAS), a grass-roots software development platform (www.spedas.org), is now officially supported by NASA Heliophysics as part of its data environment infrastructure. It serves more than a dozen space missions and ground observatories and can integrate the full complement of past and upcoming space physics missions with minimal resources, following clear, simple, and well-proven guidelines. Free, modular and configurable to the needs of individual missions, it works in both command-line (ideal for experienced users) and Graphical User Interface (GUI) mode (reducing the learning curve for first-time users). Both options have “crib-sheets,” user-command sequences in ASCII format that can facilitate record-and-repeat actions, especially for complex operations and plotting. Crib-sheets enhance scientific interactions, as users can move rapidly and accurately from exchanges of technical information on data processing to efficient discussions regarding data interpretation and science. SPEDAS can readily query and ingest all International Solar Terrestrial Physics (ISTP)-compatible products from the Space Physics Data Facility (SPDF), enabling access to a vast collection of historic and current mission data. The planned incorporation of Heliophysics Application Programmer’s Interface (HAPI) standards will facilitate data ingestion from distributed datasets that adhere to these standards. Although SPEDAS is currently Interactive Data Language (IDL)-based (and interfaces to Java-based tools such as Autoplot), efforts are under-way to expand it further to work with python (first as an interface tool and potentially even receiving an under-the-hood replacement). We review the SPEDAS development history, goals, and current implementation. We explain its “modes of use” with examples geared for users and outline its technical implementation and requirements with software developers in mind. We also describe SPEDAS personnel and software management, interfaces with other organizations, resources and support structure available to the community, and future development plans.Published versio

Microwave saturation of the Rydberg states of electrons on helium

We present measurements of the resonant microwave excitation of the Rydberg energy levels of surface state electrons on superfluid helium. The temperature dependent linewidth agrees well with theoretical predictions and is very small below 300 mK. Absorption saturation and power broadening were observed as the fraction of electrons in the first excited state was increased to 0.49, close to the thermal excitation limit of 0.5. The Rabi frequency was determined as a function of microwave power. The high values of the ratio of the Rabi frequency to linewidth confirm this system as an excellent candidate for creating qubits.Comment: 4 pages, 4 figure

Comparación de citología mediante aspirado de aguja fina e histología en el diagnóstico de lipidosis hepática en bovinos de matadero

El objetivo de este estudio fue comparar resultados de citología e histología en la detección de acúmulo de lípido hepatocelular en bovinos. La lipidosis hepática en ganado lechero es una enfermedad de gran importancia clínica y económica. La citología de aspirado de aguja fina (AAF) ha sido descrita como una técnica capaz de identificar lipidosis hepática en bovinos, sin embargo se carece de estudios que evalúen la exactitud del método. Este estudio corresponde a un primer paso para probar nuestra hipótesis de que la citología de AAF es un método de una exactitud razonable, económico y practicable para diagnosticar lipidosis hepática en bovinos. Se obtuvo 73 muestras a partir de hígados de matadero inmediatamente post mortem. Utilizando una escala de 1 a 4 se determinó la severidad de la lesión tanto para el porcentaje de células afectadas como para el promedio de citoplasma afectado. Se utilizaron muestras pareadas que representaron un espectro de las lesiones. La correlación entre el grado de afección de hepatocitos y citoplasma entre citología e histología fue altamente significativa. El puntaje dado para porcentaje de hepatocitos afectados fue diferente en ≤1 punto entre citología e histología en el 73% de los casos. Para el caso de porcentaje de citoplasma afectado esta diferencia de ≤1 punto entre ambas técnicas se presentó en el 95% de los casos. La prueba de concordancia de Kappa entre citología e histología fue adecuada. Estos hallazgos sugieren que la citología de aspirado de aguja fina puede ser un método aceptable para diagnosticar hígado graso en ganado bovino. Se requieren más estudios en animales vivos con sospecha clínica de lipidosis hepática

Hydrodynamics of Pilot-Scale Bubble Columns: Effect of Internals

The Gas Holdup and Bubble Characteristics Are Key Parameters that Affect the Performance of Bubble Columns. an Experimental Study of the Effect of Heat Exchanging Internals on the Gas Holdup, Bubble Dynamics, and their Radial Profiles is Performed. an Air-Water System is Used in a Plexiglas Column 45 Cm (18 In.) in Diameter. Internals Configurations Mimicking Those Typical for the Liquid-Phase Methanol Synthesis and Fischer-Tropsch Process and Covering 5% and 25%, Respectively, of the Total Cross-Sectional Area of the Column, Are Investigated. High Superficial Gas Velocities that Fall within the Churn Turbulent Flow Regime, Which Are of Interest for Most Industrial Applications, Are Applied. an Increase in the Gas Holdup is Observed for the Dense Internals Structure. a Decrease in the Bubble Chord Length and a Vigorous Recirculation Behavior Are Also Obtained as a Result of the Insertion of the Internals. © 2012 American Chemical Society

miR-196b target screen reveals mechanisms maintaining leukemia stemness with therapeutic potential.

We have shown that antagomiR inhibition of miRNA miR-21 and miR-196b activity is sufficient to ablate MLL-AF9 leukemia stem cells (LSC) in vivo. Here, we used an shRNA screening approach to mimic miRNA activity on experimentally verified miR-196b targets to identify functionally important and therapeutically relevant pathways downstream of oncogenic miRNA in MLL-r AML. We found Cdkn1b (p27Kip1) is a direct miR-196b target whose repression enhanced an embryonic stem cell–like signature associated with decreased leukemia latency and increased numbers of leukemia stem cells in vivo. Conversely, elevation of p27Kip1 significantly reduced MLL-r leukemia self-renewal, promoted monocytic differentiation of leukemic blasts, and induced cell death. Antagonism of miR-196b activity or pharmacologic inhibition of the Cks1-Skp2–containing SCF E3-ubiquitin ligase complex increased p27Kip1 and inhibited human AML growth. This work illustrates that understanding oncogenic miRNA target pathways can identify actionable targets in leukemia