Low-current hollow cathode evaluation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76856/1/AIAA-1999-2575-648.pd

The effects of stress management interventions among police officers and recruits

Law enforcement organizations began to take notice of officer stress during the late 1970s. Stress has been found to not only affect the officers’ job performance, but their personal lives and relationships as well. Because police officers are first responders to potentially stressful situations, their ability to successfully manage stress is critical not only to their own mental health but to the safety of society as a whole. Research has found that police officers who have difficulties coping with stress exhibit maladaptive behavior and personality traits such as aloofness, authoritarianism, cynicism, depersonalization, emotional detachment, suspiciousness, and excessive use of alcohol. High levels of stress can lead to serious physiological (headaches, stomachaches, backaches, ulcers, heart attacks) and psychological (anxiety, depression, flashbacks, and panic attacks) symptoms. Stress among police officers has also been connected to police misconduct and can also have a negative effect on the law enforcement organization due to lawsuits resulting from officers’ performance. Other organizational effects include impaired officer performance, lower productivity, poor morale, poor public relations, labor-management problems, tardiness and missed work, and officer turnover. Law enforcement organizations provide a wide variety of stress management interventions aimed at ameliorating officer stress. The objectives of this systematic review were to identify, retrieve, evaluate and synthesize the available evidence regarding outcomes of stress management interventions provided to veteran police officers and recruits. The review question is: What are the effects of officer stress management interventions on stress outcomes

Fatal thrombosis after administration of activated prothrombin complex concentrates in a patient supported by extracorporeal membrane oxygenation who had received activated recombinant factor VII

AbstractJ Thorac Cardiovasc Surg 2002;124:852-

The Zwicky Transient Facility Alert Distribution System

The Zwicky Transient Facility (ZTF) survey generates real-time alerts for optical transients, variables, and moving objects discovered in its wide-field survey. We describe the ZTF alert stream distribution and processing (filtering) system. The system uses existing open-source technologies developed in industry: Kafka, a real-time streaming platform, and Avro, a binary serialization format. The technologies used in this system provide a number of advantages for the ZTF use case, including (1) built-in replication, scalability, and stream rewind for the distribution mechanism; (2) structured messages with strictly enforced schemas and dynamic typing for fast parsing; and (3) a Python-based stream processing interface that is similar to batch for a familiar and user-friendly plug-in filter system, all in a modular, primarily containerized system. The production deployment has successfully supported streaming up to 1.2 million alerts or roughly 70 GB of data per night, with each alert available to a consumer within about 10 s of alert candidate production. Data transfer rates of about 80,000 alerts/minute have been observed. In this paper, we discuss this alert distribution and processing system, the design motivations for the technology choices for the framework, performance in production, and how this system may be generally suitable for other alert stream use cases, including the upcoming Large Synoptic Survey Telescope.Comment: Published in PASP Focus Issue on the Zwicky Transient Facility (doi: 10.1088/1538-3873/aae904). 9 Pages, 2 Figure

Multicolour correlative imaging using phosphor probes

Correlative light and electron microscopy exploits the advantages of optical methods, such as multicolour probes and their use in hydrated live biological samples, to locate functional units, which are then correlated with structural details that can be revealed by the superior resolution of electron microscopes. One difficulty is locating the area imaged by the electron beam in the much larger optical field of view. Multifunctional probes that can be imaged in both modalities and thus register the two images are required. Phosphor materials give cathodoluminescence (CL) optical emissions under electron excitation. Lanthanum phosphate containing thulium or terbium or europium emits narrow bands in the blue, green and red regions of the CL spectrum; they may be synthesised with very uniform-sized crystals in the 10- to 50-nm range. Such crystals can be imaged by CL in the electron microscope, at resolutions limited by the particle size, and with colour discrimination to identify different probes. These materials also give emissions in the optical microscope, by multiphoton excitation. They have been deposited on the surface of glioblastoma cells and imaged by CL. Gadolinium oxysulphide doped with terbium emits green photons by either ultraviolet or electron excitation. Sixty-nanometre crystals of this phosphor have been imaged in the atmospheric scanning electron microscope (JEOL ClairScope). This probe and microscope combination allow correlative imaging in hydrated samples. Phosphor probes should prove to be very useful in correlative light and electron microscopy, as fiducial markers to assist in image registration, and in high/super resolution imaging studies

Quantification of DNA-associated proteins inside eukaryotic cells using single-molecule localization microscopy

Development of single-molecule localization microscopy techniques has allowed nanometre scale localization accuracy inside cells, permitting the resolution of ultra-fine cell structure and the elucidation of crucial molecular mechanisms. Application of these methodologies to understanding processes underlying DNA replication and repair has been limited to defined in vitro biochemical analysis and prokaryotic cells. In order to expand these techniques to eukaryotic systems, we have further developed a photo-activated localization microscopy-based method to directly visualize DNA-associated proteins in unfixed eukaryotic cells. We demonstrate that motion blurring of fluorescence due to protein diffusivity can be used to selectively image the DNA-bound population of proteins. We designed and tested a simple methodology and show that it can be used to detect changes in DNA binding of a replicative helicase subunit, Mcm4, and the replication sliding clamp, PCNA, between different stages of the cell cycle and between distinct genetic backgrounds

Wear Testing and Analysis of Ion Engine Discharge Cathode Keeper

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77116/1/AIAA-4441-635.pd

Fast left prefrontal rTMS acutely suppresses analgesic effects of perceived controllability on the emotional component of pain experience

The prefrontal cortex may be a promising target for transcranial magnetic stimulation (TMS) in the management of pain. It is not clear how prefrontal TMS affects pain perception, but previous findings suggest that ventral lateral and medial prefrontal circuits may comprise an important part of a circuit of ‘perceived controllability’ regarding pain, stress and learned helplessness. While the left dorsolateral prefrontal cortex is a common TMS target for treating clinical depression as well as modulating pain, little is known about whether TMS over this area may affect perceived controllability. The present study explored the immediate effects of fast TMS over the left dorsolateral prefrontal cortex on the analgesic effects of perceived pain controllability. Twenty-four healthy volunteers underwent a laboratory pain task designed to manipulate perception of pain controllability. Real TMS, compared to sham, suppressed the analgesic benefits of perceived-control on the emotional dimension of pain, but not the sensory/discriminatory dimension. Findings suggest that, at least acutely, fast TMS over the left dorsolateral prefrontal cortex may interrupt the perceived-controllability effect on the emotional dimension of pain experience. While it is not clear whether this cortical area is directly involved with modulating perceived controllability or whether downstream effects are responsible for the present findings, it appears possible that left dorsolateral prefrontal TMS may produce analgesic effects by acting through a cortical ‘perceived control’ circuit regulating limbic and brainstem areas of the pain circuit