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The purpose of this study was to assess self-reported infection prevention processes and their effect on businesses of chiropractic doctors (DCs) and licensed massage therapists (LMTs) in Mississippi during the COVID-19 pandemic.We developed a survey that was electronically delivered to all licensed DCs and LMTs in Mississippi between August and September 2020. Assessments were made using Qualtrics software, with data management and subsequent analysis including Pearson's χResponses were based on 32 of 323 DCs and 69 of 934 LMTs that were still seeing patients through the pandemic (n = 101, response rate 8%). The DC and LMT practitioners (94%) used treatment table and/or surface sanitizing (91.8%) and hand washing and/or sanitizing (89.8%) between all patients. Female practitioners reported practicing handwashing for at least 20 seconds, whereas male practitioners reported practicing handwashing for at least 15 seconds (Most respondents had moderate to high compliance with guidelines on recommended infection prevention processes during fall 2020 of the COVID-19 pandemic. This assessment of compliance may be used to help guide future health education and promotion research of disease prevention and mitigation as well as physical and economic burdens faced by DCs and LMTs in Mississippi during a pandemic.

Objectives The aims of the study were (1) to determine the frequency of neck pain in patients diagnosed with mild traumatic brain injury (mTBI) or concussion in a pediatric level 1 trauma center emergency department (ED), (2) to identify variables associated with neck pain in this population, and (3) to report on aspects of care received in the ED including imaging and medication use. Methods This is a retrospective chart review of 652 patients presenting to a pediatric ED with diagnosis of concussion/mTBI. Charts were reviewed for the following information: baseline demographic information, mechanism of injury, cause of mTBI, presence or absence of neck pain, point tenderness in the neck on physical examination, and whether the patient followed up within our health system in the 6 months after injury. Charts were also reviewed for other concussion-related symptoms, medication given in the ED, imaging performed in the ED, cervical spine clearance in the ED, and referrals made. For those patients who did have follow-up appointments within our system, additional chart review was performed to determine whether they sought follow-up treatment for symptoms related to concussion/neck pain and the duration of follow-up. Statistical analyses focused on the prevalence of neck pain in the sample. We subsequently explored the degree to which neck pain was associated with other collected variables. Results Of 652 patients, 90 (13.8%) reported neck pain. Acceleration/deceleration injury and motor vehicle accident were predictive of neck pain. Neck pain was less common in those reporting nausea and vomiting. Direct impact of the head against an object was associated with reduced odds of neck pain, but after adjusting for other variables, this was no longer statistically significant. Patients with neck pain were older than those without neck pain. Patients with neck pain were more likely to receive ibuprofen or morphine and undergo imaging of the spine. They were also more likely to receive a referral and follow-up with neurosurgery. There was no significant difference between groups with respect to concussion-related follow-up visits or follow-up visits to a dedicated concussion clinic. Conclusions Neck pain is a common symptom in pediatric patients with mTBI, although it was more likely in older patients and those presenting with acceleration/deceleration mechanisms. Although patients with neck pain were more likely to receive a referral and follow-up with neurosurgery, they were not more likely to have concussion-related follow-up visits. Indeed, most patients had no follow-up visits related to their concussion, which supports the notion that concussion is a self-limiting condition.

The US Army Corps of Engineers (USACE)'s Engineering With Nature® (EWN®) initiative consistently promotes the use of collaboration for identifying innovative, nature-based solutions (NBS) that lead to more resilient communities and water-based infrastructure. In recent years, EWN researchers, in partnership with landscape architects (LAs) affiliated with the Dredge Research Collaborative (DRC), have championed an innovative, collaborative strategy that offers traditional planners an opportunity to participate in visioning exercises during the initial phases of coastal storm risk management projects. This has resulted in the identification, development, and incorporation of design concepts that prioritize NBS and the placement of natural and nature-based features (NNBF). These concepts, and their development process, have been documented in reports for the use of both the participating planners and other audiences interested in innovative NNBF. Upon observing these favorable outcomes, it has become clear that the integration of disciplines-landscape architecture, applied science, and engineering-has increased our ability to process, utilize, and communicate complex information. Both groups (i.e., DRC's LAs and EWN engineers and scientists) have considerable experience related to infrastructure design and performance; they elucidate ways to achieve functional engineering criteria while also maximizing ecological value and/or promoting more recreational opportunities. However, this partnership also produces a complementary set of uniquely acquired skills and expertise, which advances the development of NBS through accelerated and more meaningful communications. This study will offer insight into the partnership, collaborative techniques, and resulting products that have fostered innovation as well as advocacy for more sustainable infrastructure. Integr Environ Assess Manag 2021;00:1-7. © 2021 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Damaging storm events frequently impact the Texas coast. In response, the US Army Corps of Engineers Galveston District (SWG) has undertaken the Sabine-to-Galveston (S2G) Coastal Storm Risk Management (CSRM) Project. This approximately $3.9B project includes numerous measures across several counties of the upper Texas coast, including levees, floodwalls, and pump stations. In June 2019, SWG leadership enlisted a team including the paper authors to integrate Engineering With Nature (EWN) strategies into this infrastructure project. EWN strategies intentionally align natural and engineering processes to efficiently and sustainably deliver economic, environmental, and social benefits through collaboration. The first step in this process was to develop potentially relevant EWN strategies. A collaborative workshop included visits to project sites and working sessions where the project team reviewed challenges associated with each site, generated an array of EWN strategies, and began to test design concepts based on those strategies through collaborative drawing sessions. Afterward, prioritized ideas were refined and evaluated in terms of property acquisition, estimated cost, logistics, stakeholder and sponsor interest, constructability, aesthetics, recreational opportunities, and ecological benefit. Design concepts considered feasible for integration into the broader S2G project included horizontal levees, inland floodwater storage areas that double as wildlife habitat, and strategic placement of sediment berms to reduce storm impacts and provide marsh substrate. All these concepts should achieve intended CSRM outcomes while enhancing environmental and social benefits. This assimilation of EWN strategies and landscape architecture techniques into a large CSRM study illustrates a method for expanding overall project value and producing infrastructure that benefits coastal communities. Integr Environ Assess Manag 2022;18:63-73. © 2021 SETAC.

Background context The North American Spine Society's (NASS) Evidence Based Clinical Guideline for the Diagnosis and Treatment of Low Back Pain features evidence-based recommendations for diagnosing and treating adult patients with nonspecific low back pain. The guideline is intended to reflect contemporary treatment concepts for nonspecific low back pain as reflected in the highest quality clinical literature available on this subject as of February 2016. PURPOSE The purpose of the guideline is to provide an evidence-based educational tool to assist spine specialists when making clinical decisions for adult patients with nonspecific low back pain. This article provides a brief summary of the evidence-based guideline recommendations for diagnosing and treating patients with this condition. Study design This is a guideline summary review. Methods This guideline is the product of the Low Back Pain Work Group of NASS’ Evidence-Based Clinical Guideline Development Committee. The methods used to develop this guideline are detailed in the complete guideline and technical report available on the NASS website. In brief, a multidisciplinary work group of spine care specialists convened to identify clinical questions to address in the guideline. The literature search strategy was developed in consultation with medical librarians. Upon completion of the systematic literature search, evidence relevant to the clinical questions posed in the guideline was reviewed. Work group members utilized NASS evidentiary table templates to summarize study conclusions, identify study strengths and weaknesses, and assign levels of evidence. Work group members participated in webcasts and in-person recommendation meetings to update and formulate evidence-based recommendations and incorporate expert opinion when necessary. The draft guideline was submitted to an internal and external peer review process and ultimately approved by the NASS Board of Directors. Results Eighty-two clinical questions were addressed, and the answers are summarized in this article. The respective recommendations were graded according to the levels of evidence of the supporting literature. Conclusions The evidence-based clinical guideline has been created using techniques of evidence-based medicine and best available evidence to aid practitioners in the diagnosis and treatment of adult patients with nonspecific low back pain. The entire guideline document, including the evidentiary tables, literature search parameters, literature attrition flowchart, suggestions for future research, and all of the references, is available electronically on the NASS website at https://www.spine.org/ResearchClinicalCare/QualityImprovement/ClinicalGuidelines.aspx

This study presents an initial design for a novel system consisting in a coupled nuclear reactor and a phase change material-based thermal energy storage (TES) component, which acts as a buffer and regulator of heat transfer between the primary and secondary loops. The goal of this concept is to enhance the capacity factor of nuclear power plants (NPPs) in the case of high integration of renewable energy sources into the electric grid. Hence, this system could support in elevating the economics of NPPs in current competitive markets, especially with subsidized solar and wind energy sources, and relatively low oil and gas prices. Furthermore, utilizing a prismatic-core advanced high temperature reactor (PAHTR) cooled by a molten salt with a high melting point, have the potential in increasing the system efficiency due to its high operating temperature, and providing the baseline requirements for coupling other process heat applications. The present research studies the neutronics and thermal hydraulics (TH) of the PAHTR as well as TH calculations for the TES which consists of 300 blocks with a total heat storage capacity of 150 MWd. SERPENT Monte Carlo and MCNP5 codes carried out the neutronics analysis of the PAHTR which is sized to have a 5-year refueling cycle and rated power of 300 MWth. The PAHTR has 10 metric tons of heavy metal with 19.75 wt% enriched UO2 TRISO fuel, a hot clean excess reactivity and shutdown margin of $33.70 and -$115.68; respectively, negative temperature feedback coefficients, and an axial flux peaking factor of 1.68. Star-CCM + code predicted the correct convective heat transfer coefficient variations for both the reactor and the storage. TH analysis results show that the flow in the primary loop (in the reactor and TES) remains in the developing mixed convection regime while it reaches a fully developed flow in the secondary loop. Keywords: High temperature reactors, Phase change material, Thermal energy storage

Following Kaplanian tradition, this chapter calls both pure indexicals like ‘I’ and demonstratives like ‘she’ and ‘that’ indexicals. Though these expressions all have uses in which they are used to talk about particular people and objects, as Nunberg (1993) pointed out, they also have uses in which they allow the sentences they occur in to convey claims that in some sense don’t seem to be about particular people and objects: 1. (uttered by Tracey to Glenn, who she just let in the door, explaining why she didn’t answer the door sooner) ‘You could have been a murderer!’ 2. (uttered pointing at the Pope) ‘He is usually Italian.’ 3. (uttered by a condemned prisoner) ‘I am traditionally allowed to order whatever I like for my last meal.’ This chapter gives an account of how these readings of 1–3 arise.

Introduction Cardiovascular disease (CVD) is the most common cause of death both globally and in the United Arab Emirates. Despite public health measures and health education, the rates of death from CVD remain stable. Barriers previously identified to lifestyle changes include cultural reasons, boredom, and lack of family support. The Emirates Heart Health Project (EHHP) seeks to support healthy lifestyle changes through a family-based intervention using a health coach and fitness tracker. Methods and analysis The EHHP is a stepped-wedge cluster-randomized trial with each cluster comprised of members of an extended family. Eligible participants will be ≥ 18 years of age, with BMI ≥ 25, have Emirati citizenship and be able to give informed consent for study participation. The cluster will have 16 weekly teaching sessions in the participants’ family home by a health coach who will review individual weight, diet and exercise (monitored by a wearable fitness tracker). The clusters will have pre-intervention assessments of their weight and CVD risk profile and enter the intervention in randomized order. Each cluster will have a post-intervention assessment of the same measures. The primary outcome is weight reduction from baseline. Secondary outcomes will include change in CVD risk factors such as systolic and diastolic blood pressure, hemoglobin A1c, total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides, waist circumference, and BMI. A mixed linear model will be used for analysis, where the parameters measured at the end of each 16-week episode will be the outcome values. These will be analyzed such that baseline values (measured just prior to the start of an episode) will be fixed covariables. Random effects are the family units. This trial has been registered with the NIH at clinicaltrials.gov (NCT04688684) and is being reported using the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) and TIDieR (Template for intervention description and replication) framework. Trial registration Clinicaltrials.gov NCT04688684.

In cases of felicitous underspecification, instead of having a unique semantic value in context, the relevant expression is associated with a range of candidate semantic values in context. I formulate an account of the mechanism that associates this range of candidate semantic values in context with the relevant expression. I argue that it is the same mechanism that associates expressions with unique semantic values in context in “normal” cases.

It is arguable that the word ‘I’ has a context invariant meaning that suffices to secure semantic values for it in context. Set ‘I’ in a context and its context invariant meaning secures the speaker of the context as its semantic value in that context (at least if there is one). Consider the class of contextually sensitive expressions whose context invariant meanings arguably do ...

Some underspecified expressions are felicitous and some aren’t. To explain this, I formulate the notion of a context being appropriate for a sentence (LF). I show that if a sentence is felicitous in a context, that context is appropriate for the sentence.

I consider the results of embedding sentences containing felicitous underspecified expressions in certain environments. In particular, I consider embeddings under negation, and verbs of propositional attitude. These cases give rise to a new possibility for update. The update rule from Chapter 3 is shown to handle these embedded cases.

Many examples of felicitous underspecification are given. In each case, how conversational participants update the context in response to accepting a sentence containing an instance of felicitous underspecification is described.

Having given many examples of felicitous underspecification in the previous chapter and saying how we update the context in such cases, I provide an update rule that correctly predicts these updates. I also argue that the update rule has good intuitive backing. I consider a case in the literature discussed by Kai von Fintel and Anthony Gillies that superficially looks like a case of underspecification and argue that it isn’t. Finally, I argue that no existing update rule such as diagonalization makes correct predications about updating in cases of felicitous underspecification.

This book illustrates some of the current challenges and hazards experienced by military installations, and the content highlights activities at seven military installations to achieve increased resilience through natural infrastructure.

To deliver infrastructure that sustain our communities, economy, and environment, we must innovate, modernize, and even revolutionize our approach to infrastructure development. Change takes courage, but as one starts down the path of innovation, what was once novel becomes more familiar, more established. The U.S. Army Corps of Engineers (USACE) is walking this path with our partners through the Engineering With Nature (EWN) Initiative, integrating human engineering with natural systems. The International Guidelines on Natural and Nature-Based Features for Flood Risk Management are the next step toward revolutionary infrastructure development—a set of real-world guidelines to help familiarize us with what was once novel. USACE and collaborators around the world have been building, learning, and documenting the best practices for constructing Natural and Nature-Based Features (NNBF) for decades. The consolidation of these lessons into a single guidance document gives decision-makers and practitioners a much-needed resource to pursue, consider, and apply NNBF for flood risk management while expanding value through infrastructure. Relationships and partnerships are vital ingredients for innovation and progress. The NNBF Guidelines was achieved because of the strong relationships in the nature-based engineering community. The magnitude and diversity of contributors to the NNBF Guidelines have resulted in a robust resource that provides value beyond a single agency, sector, or nation. Similarly, the work of incorporating NNBF into projects will require us to strengthen our relationships across organizations, mandates, and missions to achieve resilient communities. I hope you are inspired by the collaborative achievement of the NNBF Guidelines and will draw from this resource to develop innovative solutions to current and future flood risk management challenges. There is a lot we can achieve together along the path of revolutionary infrastructure development.

A preliminary neutron reflector material selection and feasibility study of an inexpensive reflector replacement for the neutron beam-port at the 200 kW Missouri University of Science and Technology Research Reactor (MSTR) was conducted using Monte-Carlo techniques. The Monte-Carlo N-Particle transport code (MCNP6.1) was used to model the neutron beam-port of the Missouri S&T Reactor in order to study the effects of adding different reflector materials, in terms of the neutron flux reaching the radiography/tomography facility in front of MSTR’s neutron beam-port. Aluminum, beryllium, titanium, nickel, nickel-58, lead, bismuth, tungsten and stainless steel reflectors were modeled to find the best neutron reflector for the beam-port. After examining reflector materials, it was concluded that none of them were an improvement over the current design. Experimental thermal flux was measured to be 1.0 × 107 ± 3.16 × 103 cm−2 s−1 at the exit of beam port for current version of beam-port. The current ratio of beam port inlet and outlet obtained from simulations was found to be 3.37 × 104. The flux of beam port inlet was determined on the order of 1.0 × 1011 cm−2 s−1 which is consistent with previous findings.

COMSOL Multiphysics has been used to conduct thermal-hydraulic analysis in multiple nuclear applications. The aim of this study is to benchmark the prediction accuracy of COMSOL Multiphysics in performing thermal-hydraulic analysis of TRIGA (Training, Research, Isotopes, General Atomics) reactors such as the Geological Survey TRIGA Reactor (GSTR) by comparing its predictions with RELAP5 (a widely used code in nuclear thermal-hydraulic analysis) results and experimental data. The GSTR type is Mark I with a full thermal power of 1 MW, and it resides at the Denver Federal Center (DFC) in Colorado. The numerical investigation of the present work is carried out by developing single-subchannel thermal-hydraulic models of the GSTR utilizing RELAP5 and COMSOL codes. The models estimate the temperatures (fuel, outer clad, and coolant) and water flow patterns in the core as well as fuel element powers at which void starts to form within the coolant subchannels. Then, these models’ predictions are quantitatively evaluated and compared with the measured data.

The article of record as published may be found at http://dx.doi.org/10.2514/1.G003816 The agility of a rigid-body spacecraft can be expressed in terms of a geometric, three-dimensional, solid called the agilitoid. Originally developed as a means for explaining the concept of “hidden agility” made visible through the use of optimal control techniques, a modified agilitoid called an agility envelope is presented here that is compatible with conventional eigenaxis maneuvers. This paper demonstrates how the agility envelope can be applied to size an attitude control system (ACS) and/or assess the capability of an existing design. Analysis of the James Webb Space Telescope (JWST) ACS shows that the agility envelope accurately predicts the true capability of the ACS: a 90 deg maneuver can actually be completed 15% faster than the conventional back-of-the-envelope slew-sizing equations suggest. The utility of the agility envelope is further illustrated by showing how an alternative control allocation scheme can reduce the JWST torque and momentum requirements by 40%. The otherwise hidden agility can be recovered to enhance the slew performance of the JWST or allow the reaction wheel array to be reduced from six to five wheels, while meeting existing maneuver requirements. The agility envelope allows such design trades to be studied without the need to perform detailed simulations of the attitude control system.

Coastal Louisiana (USA) continues to sustain immense land and habitat losses due to subsidence, sea-level rise, and storm events. Approximately 65 million m3 (85 million cubic yards) of sediment is dredged annually from Gulf Coast federal navigation channels to maintain safe waterway passage. The beneficial use of these sediments continues to increase, and now this sediment is recognized as a critical resource in large-scale (estimated multibillion dollar) ecosystem restoration efforts to mitigate land and habitat losses along the US Gulf Coast. However, the documentation of restoration benefits where dredged sediments are the primary resource is lacking, which limits the potential for future applications. Therefore, this study documents the progress to restore marsh habitat and the resultant benefits in West Bay, Louisiana, and investigates how the restoration practices align with principles of the US Army Corps of Engineers (USACE) Engineering with Nature® (EWN®) and UN Sustainable Development Goals (UNSDGs). West Bay, a 4964-ha subdelta adjacent to the Mississippi River, typifies risks of coastal land loss that also threatens the integrity of the adjacent federal navigation channel. To help restore coastal marsh habitat on a large spatial and temporal scale, the USACE constructed an uncontrolled diversionary channel from the Mississippi River and with subsequent direct and strategic placement of dredged sediment. Restoration performance was assessed through remotely sensed methods using data spanning approximately 70 years. To date, placement of dredged sediment in the bay has facilitated the creation of over 800 ha of new land in the formerly open waters of West Bay. The West Bay restoration project aligns with the principles of the EWN initiative, which supports more sustainable practices to deliver economic, environmental, and social benefits through collaborative processes and meaningfully integrates 10 of the UN SDGs designed to achieve a better and more sustainable future. Integr Environ Assess Manag 2021;00:1-12. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.

Many philosophers believe that there is a kind of thought about an object that is in some sense particularly directly about the object. The chapter will use the terms de re or singular thought for thoughts of this sort. It outlines a broadly Russellian approach to singular thought on which to have a singular thought about an object o is to have a thought whose content is a singular proposition having o as a constituent. It then explores some of the consequences of this view. It also critically discusses recent attempts by Francois Recanati and Robin Jeshion to explicate the notion of singular thought by means of the notion of a mental file.

A LEU-fueled space reactor would avoid the security concerns inherent with Highly Enriched Uranium (HEU) fuel and could be attractive to signatory countries of the Non-Proliferation Treaty (NPT) or commercial interests. The HEU-fueled Kilowatt Reactor Using Stirling Technology (KRUSTY) serves as a basis for a similar reactor fueled with LEU fuel. Based on MCNP6™ neutronics performance estimates, the size of a 5 kWe reactor fueled with 19.75 wt% enriched uranium-10 wt% molybdenum alloy fuel is adjusted to match the excess reactivity of KRUSTY. Then, zirconium hydride moderator is added to the core in four different configurations (a homogeneous fuel/moderator mixture and spherical, disc, and helical fuel geometries) to reduce the mass of uranium required to produce the same excess reactivity, decreasing the size of the reactor. The lowest mass reactor with a given moderator represents a balance between the reflector thickness and core diameter needed to maintain the multiplication factor equal to 1.035, with a H/D ratio of 1.81. All three heterogeneous geometries yield a minimum mass reactor using a moderator/fuel ratio of 80 wt%. The lifetime is directly proportional to the initial amount of fissile material in the core in all the cases. Based on the small differences in estimated masses, but large difference in estimated lifetimes between the 60 wt% and 80 wt% moderated reactors, the 60 wt% moderated systems with disc or helical fuel geometries represent the best balance between total mass and operating lifetime.

Nanoporous material-based sensors promise easier integration into portable devices. Here, we use a nanoporous layer (∼130 nm thick) fabricated on a cover glass as a planar waveguide and integrated sensing surface. A combination of custom-built planar waveguiding experiments and the Zemax ray tracing model confirmed that the nanoporous surface produced an increased in-plane waveguide signal output in backscattering mode. Also, by addition of a fluorophore (coumarin 6) on the surface, the nanoporous glass showed increased interactions between the dye and in-plane waveguided light, resulting in 4–6× higher emission. Utilizing the nanoporous glass as an integrated chemical and mechanical surface, we report a fluorescent planar waveguide-based oxygen sensor that is operational in backscattering mode. We showed an 11× improvement in the sensing signal upon using an appropriate filter and a ∼2× overall improvement for the nanoporous glass over plain glass in oxygen sensing. The Stern–Volmer (SV) plot confirmed a...

The ability to create nuclear weapons from 235U and 239Pu makes it imperative to closely account for these materials as they progress through a nuclear fuel cycle. Improved measurement syst...

SafeGuards Analysis (SGA) is a toolbox developed to allow engineers and scientists to create detailed simulations of safeguards material control and accountability simulations. SGA accepts material flow data from an external material flow model and can be used with any existing fuel cycle or material control code. This paper examines some new developments to the SGA code that allow the code to consider material losses over long time frames. The first scenario described in this paper examined an enrichment facility consisting of two material balance areas (MBAs). Cumulative sum and basic control chart tests were evaluated for a case involving a loss of material from both MBAs simultaneously and a case in which material is removed from the facility over a timescale of double the one that the tests were calibrated to detect. A second scenario represents an entire fuel cycle consisting of four MBAs and two materials of interest (low-enriched uranium and plutonium). This scenario evaluated the calibrat...

Cervical artery dissection (CAD) has been associated with spinal manipulative therapy (SMT). Although uncommonly reported, SMT-associated CADs hold devastating neurological consequences, warranting further exploration. We endeavored to investigate this association through the comparison of all CAD etiologies at a single academic medical center.A retrospective chart review was conducted of patients diagnosed with CAD or transferred to our institution for primary management of CAD during the 10-year period from 2010 to 2020 (n = 578). Patients were divided into SMT-associated (within 1 month of presentation), spontaneous, traumatic, and iatrogenic cohorts.SMT-associated dissections represented 23/578 (4%) of all dissections and 5.9% of vertebral artery dissections specifically. These patients were generally younger than those in the spontaneous (p = .004) and iatrogenic groups (p .001), and more often non-smokers or former smokers compared to the spontaneous (p = .009), traumatic (p = .001), and iatrogenic (p = .008) groups. Additionally, the SMT group had a higher mean low-density lipoprotein (LDL) than the spontaneous (p = .009) and traumatic (p = .003) types. SMT-associated CADs were more often vertebral and bilateral, compared to the spontaneous (p = .003; p .001), traumatic (p = .047; p = .004), and iatrogenic (p = .002; p = .002) groups. Outcomes including infarct (p = .112), medical treatment (p = .523), intervention (p = .47), and length of stay (p = .512) were similar between the SMT and spontaneous groups.In this unique study comparing SMT-associated CADs with other dissection etiologies, SMT-associated CADs were uncommon and not associated with worse clinical outcomes. However, SMT-associated CADs were more likely to be bilateral and affected the vertebral arteries in young, non-smoking patients with high LDL.

SafeGuards Analysis (SGA) is a computational toolbox able to simulate different safeguards scenarios across a number of different fuel cycles and at many different scales within the MATLAB Simulink framework. SGA functions by simulating Material Balance Areas (MBAs) under safeguards materials control and accountability and allows the user to define the uncertainty parameters of the associated flow and inventory measurements. The simulated safeguard system uses the uncertain measurement estimates to calculate a mass-balance across the MBA. This mass balance is then evaluated by one of a number of different statistical tests to determine if a significant amount of material has been removed from the MBA. This paper describes the design of SGA, the results of testing each element of the toolbox, and a number of single MBA example scenarios. In all of the test cases, SGA performed as expected and produced acceptable results from the single MBA scenario.

To validate an MCNP5 model of the Missouri S&T Research Reactor (MSTR), temperature and void effects on reactivity experiments were simulated and performed. We compared the keff of the modeled reactor mirroring the position of all control rods to the actual critical reactor (keff = 1.00000). In the simulation we modeled three different scenarios. In the first two scenarios, the reactor is modeled as isothermal at two different temperatures (measured experimentally near the core), and in the third scenario, we split the core into bottom and top parts and used interpolated values for the temperatures of both halves. The model predicted keff’s for the “critical reactor” between 1.00234 and 1.00248 (±0.00018) when using as temperature the experimental thermocouple readings at the top of the core and keff’s between 1.00296 to 1.00383 (±0.00018) when using the temperature of thermocouple readings at the bottom of the core. In the third experiment, a linear vertical temperature profile was included in th...

The average nuclear power plant produces twenty metric tons of used nuclear fuel per year, containing approximately 95 wt% uranium, 1 wt% plutonium, and 4 wt% fission products and transuranic elements. Fast reactors are a preferred option for the transmutation of plutonium and minor actinides; however, an optimistic deployment time of at least 20 years indicates a need for a nearer-term solution. This study considers a method for plutonium and minor actinide transmutation in existing light water reactors and evaluates a variety of transmutation fuels to provide a common basis for comparison and to determine if any single target fuel provides superior transmutation properties. A model developed using the NEWT module in the SCALE 6.1 code package provided performance data for the burnup of the target fuel rods in the present study. The target fuels (MOX, PuO 2 , Pu 3 Si 2 , PuN, PuUZrH, PuZrH, PuZrHTh, and PuZrO 2 ) are evaluated over a 1400 Effective Full Power Days (EFPD) interval to ensure each assembly remained critical over the entire burnup period. The MOX (5 wt% PuO 2 ), Pu 0.31 ZrH 1.6 Th 1.08 , and PuZrO 2 MgO (8 wt% Pu) fuels result in the highest rate of plutonium transmutation with the lowest rate of curium-244 production. This study selected eleven different burnable absorbers (B 4 C, CdO, Dy 2 O 3 , Er 2 O 3 , Eu 2 O 3 , Gd 2 O 3 , HfO 2 , In 2 O 3 , Lu 2 O 3 , Sm 2 O 3 , and TaC) for evaluation as spectral shift absorber coatings on the outside of the fuel pellets to determine if an absorber coating can improve the transmutation properties of the target fuels. The PuZrO 2 MgO (8 wt% Pu) target fuel with a coating of Lu 2 O 3 resulted in the highest rate of plutonium transmutation with the greatest reduction in curium-244 production.

The word ‘I’ has a context invariant meaning that suffices to determine semantic values for it in context. Many people, including the author of the present paper, think that a lot of contextually sensitive expressions aren’t like that: their context invariant meanings don’t by themselves suffice to secure semantic values for them in context. Demonstratives and demonstratively used pronouns are familiar examples of expressions that appear to be of this sort. But arguably, tense, quantifiers, gradable adjectives, modals, conditionals, possessives, expressions that take implicit arguments (‘John has had enough’), ‘only’, and more are examples of expressions of this sort as well. For such expressions, the question arises as to the mechanism by means of which they secure semantic values in context. Call an account of how one of these expressions manages to secure a semantic value in context a metasemantics for the expression in question.

Background Low back pain (LBP) is a widespread problem and the leading cause of disability worldwide. While the cause of LBP is multifactorial, several studies suggested that inflammatory mediators in damaged subchondral plates of degenerating discs may lead to chemical sensitization and mechanical stimulation, eventually causing pain. The goal of this study was to explore associations between such changes and LBP-related disability using dynamic contrast-enhanced MRI. Methods Thirty-two patients diagnosed with nonspecific LBP and 24 healthy control subjects were studied with dynamic contrast-enhanced (DCEMRI) MRI and T1r (spin-lattice relaxation in the rotating frame) acquisitions. DCEMRI enhancement in disc endplate regions and average T1ρ measurements in the nucleus pulposus were extracted. The LBP patients were grouped based on their Oswestry Disability Index (ODI) scores and associations between MRI measurements and ODI scores were analyzed. Results Significant associations were found between ODI scores and DCEMRI enhancement in the cartilaginous endplate regions of the most degenerated discs. ODI scores also correlated with T1ρ measurements in the nucleus pulposus of degenerating discs. Conclusions DCEMRI enhancement in the cartilaginous endplate regions and lower T1ρ measurements in the nucleus pulposus (NP) were associated with greater disability that is related to low back pain as reported on the ODI. This complements earlier reports suggesting a link between LBP and endplate degeneration. Further studies are needed to validate these findings. Significance Our findings indicated that dynamic contrast-enhanced MRI signal enhancement in the cartilaginous endplate regions were associated with greater disability related to low back pain. This signal enhancement might be an indication of inflammatory changes in disc endplate regions. Therefore, advanced quantitative imaging techniques like the ones presented in this study might be needed to complement conventional radiological evaluations to identify the subset of patients who could potentially benefit from novel therapies directed towards treating the disc endplate regions.

Lifetime prevalence of major depressive disorder (MDD) among a sample of adults in the United States has been reported as over 16%. Repetitive transcranial magnetic stimulation (rTMS) has become a treatment option for a subset of treatment-refractory patients with MDD. In a population of 159 commercial health plan individuals, we used claims data to compare utilization of antidepressants, antipsychotics, and psychotherapy during the one-year time period prior to rTMS initiation to the one-year time period starting 60 days after rTMS initiation. Both antidepressant and antipsychotic use declined significantly from three months pre-rTMS compared to each of four quarterly post-rTMS time points. Psychotherapy utilization also significantly declined post-rTMS compared to pre-rTMS. The reduction in medication utilization could reflect clinical improvement of the study population, and the absence of even greater reductions in utilization likely reflects the lack of clinical guidelines for antidepressant prescribing in the aftermath of rTMS treatment.

This paper presents the initial results of a multi-year irradiation project to evaluate the impact of manufacturing method and neutron irradiation (at doses up to 1.63 displacements per atom) on the heat capacity and thermal diffusivity of Additively Manufactured (AM) stainless steel 316 L, Inconel 718, and Inconel 625 samples at temperatures between 50 °C and 400 °C. When complete, the project will have tested 48 irradiated Laser Flash Analysis (LFA) and 48 irradiated Differential Scanning Calorimetry (DSC) specimens. At the current time, the project has tested 10 irradiated DSC and 11 irradiated LFA specimens. The unirradiated AM specimens have heat capacity values similar to, or lower than, the reference values, regardless of manufacturing method or material. The irradiated AM specimens have average heat capacities greater than the unirradiated specimens and reference values in every case. The thermal diffusivities of the unirradiated AM specimens are either larger or statistically similar to the reference values obtained from materials manufactured in conventional methods. The irradiated AM specimens exhibit lower thermal diffusivities compared to the reference unirradiated thermal diffusivity values. One of the stainless steel 316 L laser powder bed fusion samples exhibited thermal diffusivity values with statistically significant anisotropy prior to and after irradiation.

The dislocation dense cellular structures observed in additively manufactured (AM) stainless steels can allow these materials to have enhanced strength and ductility compared to conventionally manufactured materials. Effective design of radiation resistant materials often necessitates creating microstructures containing of a high density of dislocations that act as sinks for radiation induced defects. This work uses molecular dynamics simulations to study the impact of pre-existing defects on radiation damage in stainless steel 316L fabricated by the laser powder bed fusion process. The evolution of synthetically generated dislocations in a crystal system in response to multiple radiation collision cascades suggest that dislocation dense regions reduce the probability of surviving point defects forming clusters. This finding seems to result from the dislocation cores’ ability to absorb point defects, thereby limiting the formation of clusters during the recombination phase. However, after successive cascades, the ability of the dislocation entanglement to prevent defect formation is diminished and defect cluster formation trends to an equilibrium. Accordingly, it is hypothesized that in an experimental setting the dislocation cells will initially act as neutral sinks for point defects, potentially delaying the onset of radiation damage effects; but, these structures will be degraded due to radiation-enhanced diffusion and lose their effectiveness at doses above 1.5–2 displacements per atom. Nevertheless, the ability to produce complex and feature-specific microstructures suggests promise for the design of radiation tolerant materials using AM methods.

The average nuclear power plant produces twenty metric tons of used nuclear fuel per year, which contains approximately 95 wt% uranium, 1 wt% plutonium, and 4 wt% fission products and transuranic elements. Fast reactors are the preferred option for the transmutation of plutonium and minor actinides; however, an optimistic deployment time of at least 20 years indicates a need for a near-term solution. Previous simulation work demonstrated the potential to transmute transuranic elements in a modified light water reactor fuel pin. This study optimizes a quarter-assembly containing target fuels coated with spectral shift absorbers for the transmutation of plutonium and minor actinides in light water reactors. The spectral shift absorber coating on the target fuel pin tunes the neutron energy spectrum experienced by the target fuel. A coupled model developed using the NEWT module from SCALE 6.1 and a genetic algorithm module from the DAKOTA optimization toolbox provided performance data for the burnup of the target fuel pins in the present study. The optimization with the coupled NEWT/DAKOTA model proceeded in three stages. The first stage optimized a single-target fuel pin per quarter-assembly adjacent to the central instrumentation channel. The second stage evaluated a variety of quarter-assemblies with multiple target fuel pins from the first stage and the third stage re-optimized the pins in the optimal second stage quarter-assembly. An 8 wt% PuZrO2MgO inert matrix fuel pin with a 1.44 mm radius and a 0.06 mm Lu2O3 coating in a five target fuel pin per quarter-assembly configuration represents the optimal combination for the transmutation of plutonium and minor actinides in the LWR environment considered in this study.

The Colorado School of Mines installed a neutron radiography system at the United States Geological Survey TRIGA reactor in 2012. An upgraded beamline could dramatically improve the imaging capabilities of this system. This project performed computational analyses to support the design of a new beamline, with the major goals of minimizing beam divergence and maximizing beam intensity. The new beamline will consist of a square aluminum tube with an 11.43 cm (4.5 in) inner side length and 0.635 cm (0.25 in) thick walls. It is the same length as the original beam tube (8.53 m) and is composed of 1.22 m (4 ft) and 1.52 m (5 ft) flanged sections which bolt together. The bottom 1.22 m of the beamline is a cylindrical aluminum pre-collimator which is 0.635 cm (0.25 in) thick, with an inner diameter of 5.08 cm (2 in). Based on Monte Carlo model results, when a pre-collimator is present, the use of a neutron absorbing liner on the inside surface of the beam tube has almost no effect on the angular distribution of the neutron current at the collimator exit. The use of a pre-collimator may result in a non-uniform flux profile at the image plane; however, as long as the collimator is at least three times longer than the pre-collimator, the flux distortion is acceptably low.

Automated image processing routines have the potential to aid in the fuel performance evaluation process by eliminating bias in human judgment that may vary from person-to-person or sample-to-sample. This study presents several MATLAB based image analysis routines designed for fission gas void identification in post-irradiation examination of uranium molybdenum (U–Mo) monolithic-type plate fuels. Frequency domain filtration, enlisted as a pre-processing technique, can eliminate artifacts from the image without compromising the critical features of interest. This process is coupled with a bilateral filter, an edge-preserving noise removal technique aimed at preparing the image for optimal segmentation. Adaptive thresholding proved to be the most consistent gray-level feature segmentation technique for U–Mo fuel microstructures. The Sauvola adaptive threshold technique segments the image based on histogram weighting factors in stable contrast regions and local statistics in variable contrast regions. Once all processing is complete, the algorithm outputs the total fission gas void count, the mean void size, and the average porosity. The final results demonstrate an ability to extract fission gas void morphological data faster, more consistently, and at least as accurately as manual segmentation methods.