382 research outputs found

    Super Radiant Narrowing in Fluorescence Radiation of Inverted Populations

    Get PDF
    The effect of resonance reabsorption of fluorescent radiation on the spectral distribution has been considered as early as 1913 by Laudenburg and Reivhe [1]. Schein [2] and Zemansky [3] recognized that the reabsorption causes a broadening of the light emitted by resonance lamps. In this note we report an experimental and theoretical study of the complementary effect, i.e., of resonance radiation originating in a system in which the population of the upper level of the resonance transition is made to exceed that of the lower one (inverted population system)

    X-ray speed reading: enabling fast, low noise readout for next-generation CCDs

    Full text link
    Current, state-of-the-art CCDs are close to being able to deliver all key performance figures for future strategic X-ray missions except for the required frame rates. Our Stanford group is seeking to close this technology gap through a multi-pronged approach of microelectronics, signal processing and novel detector devices, developed in collaboration with the Massachusetts Institute of Technology (MIT) and MIT Lincoln Laboratory (MIT-LL). Here we report results from our (integrated) readout electronics development, digital signal processing and novel SiSeRO (Single electron Sensitive Read Out) device characterization.Comment: To appear in SPIE Proceeding of Astronomical Telescopes + Instrumentation, 202

    Assessment of patient-centered approaches to collect sexual orientation and gender identity information in the emergency department: The equality Study

    Get PDF
    Importance: Health care and government organizations call for routine collection of sexual orientation and gender identity (SOGI) information in the clinical setting, yet patient preferences for collection methods remain unknown.Objective: To assess of the optimal patient-centered approach for SOGI collection in the emergency department (ED) setting.Design, setting, and participants: This matched cohort study (Emergency Department Query for Patient-Centered Approaches to Sexual Orientation and Gender Identity [EQUALITY] Study) of 4 EDs on the east coast of the United States sequentially tested 2 different SOGI collection approaches between February 2016 and March 2017. Multivariable ordered logistic regression was used to assess whether either SOGI collection method was associated with higher patient satisfaction with their ED experience. Eligible adults older than 18 years who identified as a sexual or gender minority (SGM) were enrolled and then matched 1 to 1 by age (aged ≥5 years) and illness severity (Emergency Severity Index score ±1) to patients who identified as heterosexual and cisgender (non-SGM), and to patients whose SOGI information was missing (blank field). Patients who identified as SGM, non-SGM, or had a blank field were invited to complete surveys about their ED visit. Data analysis was conducted from April 2017 to November 2017.Interventions: Two SOGI collection approaches were tested: nurse verbal collection during the clinical encounter vs nonverbal collection during patient registration. The ED physicians, physician assistants, nurses, and registrars received education and training on sexual or gender minority health disparities and terminology prior to and throughout the intervention period.Main outcomes and measures: A detailed survey, developed with input of a stakeholder advisory board, which included a modified Communication Climate Assessment Toolkit score and additional patient satisfaction measures.Results: A total of 540 enrolled patients were analyzed; the mean age was 36.4 years and 66.5% of those who identified their gender were female. Sexual or gender minority patients had significantly better Communication Climate Assessment Toolkit scores with nonverbal registrar form collection compared with nurse verbal collection (mean [SD], 95.6 [11.9] vs 89.5 [20.5]; P = .03). No significant differences between the 2 approaches were found among non-SGM patients (mean [SD], 91.8 [18.9] vs 93.2 [13.6]; P = .59) or those with a blank field (92.7 [15.9] vs 93.6 [14.7]; P = .70). After adjusting for age, race, illness severity, and site, SGM patients had 2.57 (95% CI, 1.13-5.82) increased odds of a better Communication Climate Assessment Toolkit score category during form collection compared with verbal collection.Conclusions and relevance: Sexual or gender minority patients reported greater comfort and improved communication when SOGI was collected via nonverbal self-report. Registrar form collection was the optimal patient-centered method for collecting SOGI information in the ED

    Single electron Sensitive Readout (SiSeRO) X-ray detectors: Technological progress and characterization

    Full text link
    Single electron Sensitive Read Out (SiSeRO) is a novel on-chip charge detector output stage for charge-coupled device (CCD) image sensors. Developed at MIT Lincoln Laboratory, this technology uses a p-MOSFET transistor with a depleted internal gate beneath the transistor channel. The transistor source-drain current is modulated by the transfer of charge into the internal gate. At Stanford, we have developed a readout module based on the drain current of the on-chip transistor to characterize the device. Characterization was performed for a number of prototype sensors with different device architectures, e.g. location of the internal gate, MOSFET polysilicon gate structure, and location of the trough in the internal gate with respect to the source and drain of the MOSFET (the trough is introduced to confine the charge in the internal gate). Using a buried-channel SiSeRO, we have achieved a charge/current conversion gain of >700 pA per electron, an equivalent noise charge (ENC) of around 6 electrons root mean square (RMS), and a full width half maximum (FWHM) of approximately 140 eV at 5.9 keV at a readout speed of 625 Kpixel/s. In this paper, we discuss the SiSeRO working principle, the readout module developed at Stanford, and the characterization test results of the SiSeRO prototypes. We also discuss the potential to implement Repetitive Non-Destructive Readout (RNDR) with these devices and the preliminary results which can in principle yield sub-electron ENC performance. Additional measurements and detailed device simulations will be essential to mature the SiSeRO technology. However, this new device class presents an exciting technology for next generation astronomical X-ray telescopes requiring fast, low-noise, radiation hard megapixel imagers with moderate spectroscopic resolution.Comment: To appear in SPIE Proceedings of Astronomical Telescopes + Instrumentation, 202

    Strategic responses to global challenges: The case of European banking, 1973–2000

    Get PDF
    In applying a strategy, structure, ownership and performance (SSOP) framework to three major clearing banks (ABN AMRO, UBS, Barclays), this article debates whether the conclusions generated by Whittington and Mayer about European manufacturing industry can be applied to the financial services sector. While European integration plays a key role in determining strategy, it is clear that global factors were far more important in determining management actions, leading to significant differences in structural adaptation. The article also debates whether this has led to improved performance, given the problems experienced with both geographical dispersion and diversification, bringing into question the quality of decision-making over the long term

    Leadership and Stewardship of the Laboratory (Objective 4.1) Notable Outcome - Phase II Alternative Analysis and PNNL Site Plan Recommendation

    Get PDF
    Pacific Northwest National Laboratory (PNNL) and the Pacific Northwest Site Office (PNSO) have recently completed an effort to identify the current state of the campus and gaps that exist with regards to space needs, facilities and infrastructure. This effort has been used to establish a campus strategy to ensure PNNL is ready to further the United States (U.S.) Department of Energy (DOE) mission. Ten-year business projections and the impacts on space needs were assessed and incorporated into the long-term facility plans. In identifying/quantifying the space needs for PNNL, the following categories were addressed: Multi-purpose Programmatic (wet chemistry and imaging laboratory space), Strategic (Systems Engineering and Computation Analytics, and Collaboration space), Remediation (space to offset the loss of the Research Technology Laboratory [RTL] Complex due to decontamination and demolition), and Optimization (the exit of older and less cost-effective facilities). The findings of the space assessment indicate a need for wet chemistry space, imaging space, and strategic space needs associated with systems engineering and collaboration space. Based on the analysis, a 10-year campus strategy evolved that balanced four strategic objectives, as directed by the DOE Office of Science (DOE-SC): • Mission Alignment - maintain customer satisfaction • Reasonable & Achievable - do what makes sense from a practical and cost perspective • Campus Continuity - increase the federal control of assets and follow the Campus Master Plan • Guiding Principles - modern, collaborative, flexible, and sustainable. This strategy considered the following possible approaches to meet the identified space needs: • Institutional General Plant Project (IGPP) funded projects • Third party leased facilities • Science Laboratory Infrastructure (SLI) line item funded projects. Pairing the four strategic objectives with additional key metrics as criteria for selection, an initial recommendation was made to DOE-SC to use all three funding mechanisms to deliver the mission need. DOE-SC provided feedback that third party facilities are not to be pursued at this time. The decision was made by DOE that an IGPP-funded program would be the base plan, while retaining the possibility of a 2019 SLI-funded project. The SLI project will be designed to deliver significant impact on science and technology (S&T) and support the development of a modern, synergistic core campus where a collaborative and innovative environment is fostered. The specific scientific impact will be further defined in the 2015 and 2016 Annual Laboratory Plans. Additionally, opportunities will be explored to construct annexes on current federal facilities, including the Environmental Molecular Sciences Laboratory (EMSL), if proven synergistic and cost effective. The final result of this effort is an actionable, flexible plan with scope, schedule, and cost targets for individual acquisition projects. Implemented as planned, the result will increase federal ownership by approximately 15 percent, reduce the operating cost by approximately 7 percent, and reduce the geographic facility footprint by approximately 66,000 gross square feet (GSF). Reduction of surplus space will be addressed while maintaining customer satisfaction, lowering operating costs, reducing the campus footprint, and increasing the federal control of assets. This strategy is documented in PNNL’s 2014 Laboratory Plan

    Prospective memory functioning among ecstasy/polydrug users: evidence from the Cambridge Prospective Memory Test (CAMPROMPT)

    Get PDF
    Rationale: Prospective memory (PM) deficits in recreational drug users have been documented in recent years. However, the assessment of PM has largely been restricted to self-reported measures that fail to capture the distinction between event-based and time-based PM. The aim of the present study is to address this limitation. Objectives: Extending our previous research, we augmented the range laboratory measures of PM by employing the CAMPROMPT test battery to investigate the impact of illicit drug use on prospective remembering in a sample of cannabis only, ecstasy/polydrug and non-users of illicit drugs, separating event and time-based PM performance. We also administered measures of executive function and retrospective memory in order to establish whether ecstasy/polydrug deficits in PM were mediated by group differences in these processes. Results: Ecstasy/polydrug users performed significantly worse on both event and time-based prospective memory tasks in comparison to both cannabis only and non-user groups. Furthermore, it was found that across the whole sample, better retrospective memory and executive functioning was associated with superior PM performance. Nevertheless, this association did not mediate the drug-related effects that were observed. Consistent with our previous study, recreational use of cocaine was linked to PM deficits. Conclusions: PM deficits have again been found among ecstasy/polydrug users, which appear to be unrelated to group differences in executive function and retrospective memory. However, the possibility that these are attributable to cocaine use cannot be excluded

    The high-speed X-ray camera on AXIS

    Full text link
    AXIS is a Probe-class mission concept that will provide high-throughput, high-spatial-resolution X-ray spectral imaging, enabling transformative studies of high-energy astrophysical phenomena. To take advantage of the advanced optics and avoid photon pile-up, the AXIS focal plane requires detectors with readout rates at least 20 times faster than previous soft X-ray imaging spectrometers flying aboard missions such as Chandra and Suzaku, while retaining the low noise, excellent spectral performance, and low power requirements of those instruments. We present the design of the AXIS high-speed X-ray camera, which baselines large-format MIT Lincoln Laboratory CCDs employing low-noise pJFET output amplifiers and a single-layer polysilicon gate structure that allows fast, low-power clocking. These detectors are combined with an integrated high-speed, low-noise ASIC readout chip from Stanford University that provides better performance than conventional discrete solutions at a fraction of their power consumption and footprint. Our complementary front-end electronics concept employs state of the art digital video waveform capture and advanced signal processing to deliver low noise at high speed. We review the current performance of this technology, highlighting recent improvements on prototype devices that achieve excellent noise characteristics at the required readout rate. We present measurements of the CCD spectral response across the AXIS energy band, augmenting lab measurements with detector simulations that help us understand sources of charge loss and evaluate the quality of the CCD backside passivation technique. We show that our technology is on a path that will meet our requirements and enable AXIS to achieve world-class science.Comment: 17 pages, 11 figures, submitted to Proceedings of SPIE Optics + Photonics 202
    corecore