The Utility of Table-Top Exercises in Teaching Nuclear Security

In the emerging field of nuclear security, those responsible for education and training are constantly seeking to identify and engage with tools and approaches that provide for a constructive learning environment. In this context, this paper explores the nature and value of Tabletop exercises (TTX) and how they can be applied in the nuclear security context. On the one hand, the paper dissects the key components of the TTX and considers the broader pedagogical benefits of this teaching method. On the other hand, the paper draws lessons from the authors’ experience of running TTXs as part of nuclear security professional development courses (PDCs) over the past six years. The paper finds that the TTX holds enormous benefit as a learning resource when developed as part of a comprehensive approach to nuclear security education

Infrared Detectors for Radiation Thermometry

This work presents an investigation into the potential next generation of infrared detectors for radiation thermometry. Motivations for this work include increased detector sensitivity, development of minimally cooled mid-wave infrared (MWIR) arrays and longer wavelength multi-colour ratio radiation thermometers. The high sensitivity of the Si avalanche photodiode (APD) is highly attractive for radiation thermometry. A Si APD is shown to offer increased sensitivity by measuring a lower temperature than a Si photodiode in order to satisfy specific threshold voltages. The Si APD is also shown to offer improvement in the signal-to-noise ratio (SNR) and temperature error. By combining the Si APD with a phase sensitive detection (PSD) method, further improvement is achieved. The MWIR InAs/GaSb type-II superlattice (T2SL) offers the potential development of minimally cooled MWIR arrays for radiation thermometry, as well as longer wavelength multi-colour detectors for ratio radiation thermometry. An uncooled T2SL detector on a GaSb substrate is demonstrated for measurement of a target temperature of 25 oC with SNR > 1. Cooling improves the detector’s performance, allowing operation at the thermo-electric cooler compatible temperature of 200 K. Further characterisation of a T2SL detector on a GaAs substrate demonstrates similar temperature dependence, suggesting challenges to the material growth for improved detector performance. Other potential challenges with T2SL development are identified and discussed. The quantum dot infrared photodetector (QDIP) also offers the potential for longer wavelength multi-colour detection. Combination with an infrared algorithmic spectrometer (IRAS) offers flexibility for development of a versatile ratio radiation thermometer. The QDIP-IRAS combination is demonstrated to successfully reproduce arbitrary filter shapes from blackbody photocurrent measurements. Ratios computed using the IRAS correspond well with ratios computed from the arbitrary target filters.

Cloning of a cDNA encoding diacylglycerol acyltransferase from Arabidopsis thaliana and its functional expression

AbstractTriacylglycerols are the most important storage lipids in most plants and animals. Acyl-CoA:diacylglycerol acyltransferase (EC 2.3.1.20) catalyzes the final step of the pathway of triacylglycerol synthesis and is the only step which is unique to this process. Diacylglycerol acyltransferase is required for the synthesis of storage oil in a wide range of oil-bearing seeds and fruits and in floral structures such as petals, anthers and pollen. We describe the first cloning and functional expression of a cDNA encoding diacylglycerol acyltransferase from a plant. The cDNA, cloned from Arabidopsis thaliana, encodes a 520 amino acid protein with a predicted molecular mass of 59.0 kDa which shares 38% amino acid sequence identity with diacylglycerol acyltransferase from mouse. When expressed in insect cell cultures, the protein catalyzes the synthesis of [14C]triacylglycerol from [14C]diacylglycerol and acyl-CoA. Primer extension analysis revealed that the transcription begins 225 bases before the translation start site, yielding an unusually long 5′ untranslated region. The gene is expressed in a wide range of tissues but most strongly in developing embryos and petals of flowers

Magnetically-controlled velocity selection in a cold atom sample using stimulated Raman transitions

We observe velocity-selective two-photon resonances in a cold atom cloud in the presence of a magnetic field. We use these resonances to demonstrate a simple magnetometer with sub-mG resolution. The technique is particularly useful for zeroing the magnetic field and does not require any additional laser frequencies than are already used for standard magneto-optical traps. We verify the effects using Faraday rotation spectroscopy.Comment: 5 pages, 6 figure

The Practice Environment for Nurse Anesthetists in Tennessee

Potential consequences of anesthesia provider shortages may include a reduction in health care access, poor patient outcomes, and increased costs to government funded agencies. Current leaders in the anesthesia profession need to establish a work environment that is embracing, supportive, and safe so that certified registered nurse anesthetists (CRNA) can remain healthy and productive. The purpose of this Doctor of Nursing Practice (DNP) scholarly project was to provide an overview of the current CRNA practice environment in Tennessee and advocate for policies to promote CRNA retention and enhance patient access to care. The overarching goal included gathering sufficient evidence regarding the positive and negative working environments of CRNA practice and presenting this evidence to the Tennessee Association of Nurse Anesthetist (TANA) executive committee. The evidence-informed health policy model (EIHP) was used to identify the policy problem as well as guide the development, implementation, and evaluation of a solution. After reviewing the literature, project members discovered seven working environment outcomes that impact retention and patient access to care. Project members presented the seven outcomes to the TANA executive committee and distributed a pre and post presentation survey to evaluate how the TANA organization was doing at promoting a positive work environment for CRNAs. Finally, to compare and analyze the survey responses, project members ran paired sample t-tests. Keywords: access, access to care, advanced practice registered nurse, barriers, certified registered nurse anesthetist, nurse anesthetist, and scope of practic

Improving longitudinal research in geospatial health: An agenda

All aspects of public health research require longitudinal analyses to fully capture the dynamics of outcomes and risk factors such as ageing, human mobility, non-communicable diseases (NCDs), climate change, and endemic, emerging, and re-emerging infectious diseases. Studies in geospatial health are often limited to spatial and temporal cross sections. This generates uncertainty in the exposures and behavior of study populations. We discuss a research agenda, including key challenges and opportunities of working with longitudinal geospatial health data. Examples include accounting for residential and human mobility, recruiting new birth cohorts, geoimputation, international and interdisciplinary collaborations, spatial lifecourse studies, and qualitative and mixed-methods approaches