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Postural orthostatic tachycardia syndrome (POTS) is a common and therapeutically challenging condition affecting numerous people worldwide. Recent studies have begun to shed light on the pathophysiology of this disorder. At the same time, both non-pharmacologic and pharmacologic therapies have emerged that offer additional treatment options for those afflicted with this condition. This paper reviews new concepts in both the pathophysiology and management of POTS.

Positive Behavioral Interventions and Supports (PBIS) is an evidence-based framework for promoting positive school climates and improving student social and behavioral outcomes. Yet secondary schools have lagged behind elementary schools in their adoption and implementation of PBIS. The transition from elementary to middle school is marked by a host of developmental and environmental changes that creates a critical window for establishing supportive school environments. We conducted a series of focus groups with middle school students ( N = 45) attending PBIS schools to learn about their views and understandings of PBIS, the perceived impact of these programs, the extent to which they were involved in PBIS, and their recommendations for improving their school’s program. Although middle school students’ understanding of PBIS was often focused on their acknowledgment system, students identified a range of impacts beyond improving student behavior. Students also expressed a desire for more (a) transparent communication between staff and students and (b) opportunities for students to be actively involved in their school’s program. We discuss the implications of these findings with respect to increasing the uptake and impact of PBIS in secondary schools.

To evaluate effects of psychotropic medication for children with disabilities, direct assessments may offer a valuable supplement to caregiver reports. Relative to indirect assessment, direct measures of behavior can increase objectivity and sensitivity, and some have potential to isolate distinct behavioral and learning processes. We conducted a systematic, narrative literature review to identify and describe the types and qualities of direct assessment methods that have been used to evaluate effects of non-stimulant psychotropic medication for children with disabilities. We identified 50 studies and 78 direct assessments, which we organized and described using seven assessment categories. Only one study met all three direct assessment quality indicators. We use our descriptive results to highlight research trends and gaps that warrant further study.

Background Sitting at the bedside may strengthen physician–patient communication and improve patient experience. Yet despite the potential benefits of sitting, hospital physicians, including resident physicians, may not regularly sit down while speaking with patients. Objective To examine the frequency of sitting by internal medicine residents (including first post-graduate year [PGY-1] and supervising [PGY-2/3] residents) during inpatient encounters and to assess the association between patient-reported sitting at the bedside and patients’ perceptions of other physician communication behaviors. We also assessed residents’ attitudes towards sitting. Design In-person survey of patients and email survey of internal medicine residents between August 2019 and January 2020. Participants Patients admitted to general medicine teaching services and internal medicine residents at The Johns Hopkins Hospital. Main Measures Patient-reported frequency of sitting at the bedside, patients’ perceptions of other communication behaviors (e.g., checking for understanding); residents’ attitudes regarding sitting. Key Results Of 334 eligible patients, 256 (76%) completed a survey. Among these 256 respondents, 198 (77%) and 166 (65%) reported recognizing the PGY-1 and PGY-2/3 on their care team, respectively, for a total of 364 completed surveys. On most surveys (203/364, 56%), patients responded that residents “never” sat. Frequent sitting at the bedside (“every single time” or “most of the time,” together 48/364, 13%) was correlated with other positive behaviors, including spending enough time at the bedside, checking for understanding, and not seeming to be in a rush (p

Neighborhood disadvantage reflects historic and ongoing systemic injustices. Without addressing these upstream social determinants of health, hospitals may face different risk profiles for important quality metrics. Our objective was to assess differences in hospital characteristics where the proportion of patients residing in severely disadvantaged neighborhoods was high vs low. Using Medicare fee-for-service claims between January 1, 2014 and November 30, 2014 (5,807,499 hospital stays), we calculated Area Disadvantage Share (ADS), the proportion of each hospital’s discharges to severely disadvantaged neighborhoods, for 4,528 hospitals. We examined hospital characteristics by distribution of ADS and by risk-adjusted 30-day readmission. Hospitals in the highest decile cared for a higher proportion of Black patients, were more often located in rural areas, and had higher patient risk of 30-day readmission compared to all other deciles. Hospitals face unequal burdens of neighborhood disadvantage, a factor distinct from other social determinants such as rurality.

BACKGROUND Research and policy demonstrate the value and need for systematically identifying and preparing care partners for their caregiving responsibilities while their family member or friend living with dementia is hospitalized. The Care Partner Hospital Assessment Tool (CHAT) had undergone content and face validation and been endorsed as appropriate by clinicians to facilitate the timely identification and preparation of care partners of older adult patients during their hospitalization. However, the CHAT has not yet been adapted or prospectively evaluated for use with care partners of hospitalized persons living with dementia (PLWD). Adapting and testing the CHAT via a pilot study will provide the necessary evidence to optimize feasibility and enable future efficacy trials. OBJECTIVE To describe the study protocol for the adaptation and testing of the CHAT for use among care partners of hospitalized PLWD to better prepare them for their caregiving responsibilities after hospital discharge. METHODS Our protocol consists of two sequential phases, including a formative research and main trial. In Phase 1, we will use a participatory human-centered design process that incorporates PLWD and their care partners, healthcare administrators, and clinicians to adapt the CHAT for dementia care (i.e., D-CHAT). In Phase 2, we will partner with a large academic medical system to complete a pilot randomized controlled trial to examine the feasibility and estimate the size of the effect of the D-CHAT on care partners’ preparedness for caregiving. RESULTS The study protocol will yield: 1) a converged-upon, ready for feasibility testing, D-CHAT, 2) descriptive and feasibility characteristics of delivering the D-CHAT, and 3) effect size estimates of the D-CHAT on care partner preparedness. CONCLUSIONS We anticipate that the resultant D-CHAT will provide clinicians guidance on how to identify and better prepare care partners of hospitalized PLWD. In turn, care partners will feel equipped to fulfill caregiving roles for their family members or friends living with dementia. CLINICALTRIAL Dementia Care Partner Hospital Assessment Tool ClinicalTrials.gov Identifier: NCT05592366 https://clinicaltrials.gov/ct2/show/NCT05592366

Sea turtles represent an ancient lineage of marine vertebrates that evolved from terrestrial ancestors over 100 Mya. The genomic basis of the unique physiological and ecological traits enabling these species to thrive in diverse marine habitats remains largely unknown. Additionally, many populations have drastically declined due to anthropogenic activities over the past two centuries, and their recovery is a high global conservation priority. We generated and analyzed high-quality reference genomes for the leatherback (Dermochelys coriacea) and green (Chelonia mydas) turtles, representing the two extant sea turtle families. These genomes are highly syntenic and homologous, but localized regions of noncollinearity were associated with higher copy numbers of immune, zinc-finger, and olfactory receptor (OR) genes in green turtles, with ORs related to waterborne odorants greatly expanded in green turtles. Our findings suggest that divergent evolution of these key gene families may underlie immunological and sensory adaptations assisting navigation, occupancy of neritic versus pelagic environments, and diet specialization. Reduced collinearity was especially prevalent in microchromosomes, with greater gene content, heterozygosity, and genetic distances between species, supporting their critical role in vertebrate evolutionary adaptation. Finally, diversity and demographic histories starkly contrasted between species, indicating that leatherback turtles have had a low yet stable effective population size, exhibit extremely low diversity compared with other reptiles, and harbor a higher genetic load compared with green turtles, reinforcing concern over their persistence under future climate scenarios. These genomes provide invaluable resources for advancing our understanding of evolution and conservation best practices in an imperiled vertebrate lineage. This work was completed in part with resources provided by the University of Massachusetts' Green High Performance Computing Cluster (GHPCC). Funding was provided by the University of Massachusetts Amherst, NSF-IOS (grant #1904439 to L.M.K.), NOAA-Fisheries, National Research Council postdoctoral fellowship program to L.M.K., VGP, Rockefeller University, to E.D.J., HHMI to E.D.J., the Sanger Institute, Max-Planck-Gesellschaft, and grant contributions from Tom Gilbert, Paul Flicek, R.W.M., Karen A. Bjorndal, Alan B. Bolten, Ed Braun, N.J.G., T.M.-B., and A.F.S. We acknowledge CONICYT-DAAD for scholarship support to T.C.-V., the São Paulo Research Foundation to E.K.S.R.–FAPESP (grant #2020/10372-6). BeGenDiv is partially funded by the German Federal Ministry of Education and Research (BMbF, Förderkennzeichen 033W034A). The work of F.T.-N. and P.M. was supported by the Intramural Research Program of the National Library of Medicine, NIH. The work of M.P. was partially funded through the Federal Ministry of Education and Research (grant 01IS18026C). H.P. was supported by a Formació de Personal Investigador fellowship from Generalitat de Catalunya (FI_B100131). M.K. was supported by “la Caixa” Foundation (ID 100010434; code LCF/BQ/PR19/11700002), the Vienna Science and Technology Fund (WWTF), and the City of Vienna (VRG20-001). Funding for green turtle resequencing was provided by a Welsh Government Sêr Cymru II and the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 663830-BU115 and the Sea Turtle Conservancy, Florida Sea Turtle Grants Program (17-033R).

Vasovagal syncope (VVS) (or neurocardiogenic syncope) is a common clinical condition that is challenging to both physicians and patients alike. Severe episodes of recurrent syncope can result in physical injury as well as psychological distress. This article provides a brief overview of current management strategies and a detailed overview of therapeutic modalities such as closed loop stimulation (CLS) and cardioneuroablation (CNA).

Nest microclimates influence embryonic development and survival in many lineages, including reptiles with temperature-dependent sex determination. These microclimates are dependent on physi...

The purpose of the current study was to explore the scientific utility of two behavior analytic assessments (i.e., progressive ratio and demand assessments) for psychotropic medication evaluation. For a sample of 23 children with disabilities who were prescribed medication, we conducted a series of generalizability and optimization studies to identify sources of score variance and conditions in which stable estimates of behavior can be obtained. To inform construct validity, we calculated correlations between scores from each assessment and those from a standardized behavior rating scale (Aberrant Behavior Checklist-Second Edition; ABC-2). Results offer initial support for the scientific utility of progressive ratio scores. More research is needed to evaluate sensitivity to change and construct validity of scores from these and other behavior analytic assessments.

Although the number of U.S. schools implementing multitiered systems of support for behavior (MTSS-B) continues to grow, most schools have still not adopted these evidence-based frameworks. We examined the views of educators ( N = 561) at the outset of adopting MTSS-B in their schools or districts. Our survey addressed the (a) reasons schools and districts decided to adopt MTSS-B, (b) challenges they anticipated with respect to implementation, and (c) expected outcomes of MTSS-B. We also compared views across three groups of stakeholders: local school team members, building administrators, and district representatives. Although most participants reported multiple motivations for adopting MTSS-B, concerns about student behavior and the need for staff support in this area were among the primary reasons. Anticipated challenges varied by group, with district representatives affirming those challenges most strongly. Responses also suggest these stakeholders have high expectations regarding the impact of MTSS-B in their school or district. We discuss implications for technical assistance providers related to supporting a more widespread adoption of MTSS-B.

Postural orthostatic tachycardia syndrome (POTS) is a clinical syndrome causing patients to experience light-headedness, palpitations, tremors, and breathlessness upon assuming an upright posture. Despite the absence of available long-term, multicenter, randomized controlled trial data, this literature review aims to concisely present the nonpharmacological and pharmacological interventions that have been used in the treatment of POTS reported to date by cross-sectional studies, cohort studies, and retrospective studies. We attempt to classify treatments as first-, second-, and third-line therapies based on our own experience and available data.

Lattice physics calculations have been carried out to evaluate the performance and safety characteristics of a modified high temperature gas-cooled reactor (HTGR) prismatic fuel block concept, based on the MHTGR-350 benchmark problem. Key changes were to replace the conventional tri-structural isotropic (TRISO)-filled fuel compacts with heterogeneous, multilayer annular fuel pellets made with UCO, ThCO, or (U,Th)CO. These fuel pellets have multiple protective cladding layers of pyrolytic carbon and silicon carbide, which will give it robust qualities. With the increased loading of U-235 in the fuel block, it was necessary to replace up to 78 fuel holes and 42 coolant holes with a hydrogen-based moderator (7LiH), in order to ensure a thermal neutron energy spectrum in the lattice. Calculation results demonstrate that the modified fuel concept has several advantages and some challenges relative to the conventional MHTGR-350 design concept. With the increased uranium loading and the reduced neutron leakage due the use of 7LiH moderator rods, higher burnup levels and lower natural uranium consumption levels can be achieved with the same level of uranium enrichment. In addition, the expected fuel residence time increased by a factor of 20 or more, making such a concept very attractive for use in small, modular, “nuclear battery” HTGRs that would only need to be fueled once. Calculation results for the current concept indicate positive graphite and hydrogen moderator temperature coefficients, and further modifications will be required to ensure a negative power coefficient of reactivity.

Sinus tachycardia (ST) is ubiquitous, but its presence outside of normal physiological triggers in otherwise healthy individuals remains a commonly encountered phenomenon in medical practice. In many cases, ST can be readily explained by a current medical condition that precipitates an increase in the sinus rate, but ST at rest without physiological triggers may also represent a spectrum of normal. In other cases, ST may not have an easily explainable cause but may represent serious underlying pathology and can be associated with intolerable symptoms. The classification of ST, consideration of possible etiologies, as well as the decisions of when and how to intervene can be difficult. ST can be classified as secondary to a specific, usually treatable, medical condition (eg, pulmonary embolism, anemia, infection, or hyperthyroidism) or be related to several incompletely defined conditions (eg, inappropriate ST, postural tachycardia syndrome, mast cell disorder, or post-COVID syndrome). While cardiologists and cardiac electrophysiologists often evaluate patients with symptoms associated with persistent or paroxysmal ST, an optimal approach remains uncertain. Due to the many possible conditions associated with ST, and an overlap in medical specialists who see these patients, the inclusion of experts in different fields is essential for a more comprehensive understanding. This article is unique in that it was composed by international experts in Neurology, Psychology, Autonomic Medicine, Allergy and Immunology, Exercise Physiology, Pulmonology and Critical Care Medicine, Endocrinology, Cardiology, and Cardiac Electrophysiology in the hope that it will facilitate a more complete understanding and thereby result in the better care of patients with ST.

Introduction: Current recommendations in management of supine hypertension-orthostatic hypotension disease (SH-OH) are mainly derived from outpatient studies with the aim of controlling SH while minimizing OH symptoms rather than targeting a specific standing blood pressure value. Data on short term outcomes of patients with OH who are hospitalized with hypertensive (HTN) crises is lacking. Methods: The Nationwide Readmission Database 2016-2019 was queried for all hospitalizations of HTN crises. Hospitalizations were stratified according to whether OH was present or not. We employed propensity score to match hospitalizations for patients with OH to those without, at 1:1 ratio. Outcomes evaluated were 30-days readmission with HTN crises or falls, as well as hospital outcomes of in-hospital mortality, acute kidney injury (AKI), acute congestive heart failure (CHF), acute coronary syndrome (ACS), type 2 myocardial infarction (T2MI), aortic dissection, stroke, length of stay (LOS), discharge to nursing home and hospitalization costs. Results: We included a total of 9,451 hospitalization (4,735 in the OH group vs 4,716 in the control group). OH group was more likely to be readmitted with falls (Odds ratio [OR]:3.27, p Conclusion: Patients with OH who are admitted with HTN crises tend to have similar or lower HTN-related complications to non-OH group while having higher likelihood of readmission with falls, LOS and hospitalization costs. Further randomized studies are needed to confirm such findings

Pressure loss coefficients are generally required by subchannel and system thermalhydraulics codes. These coefficients are not readily available for small modular reactors (SMRs) featuring nonconventional designs and novel coolants. In this study, the pressure loss coefficients were obtained using three-dimensional (3D) computational fluid dynamics (CFD) modeling for an advanced water-cooled reactor. A representative light water fuel assembly used in the Organization for Economic Co-operation and Development (OECD)/National Research Council Canada (NRC) pressurized water reactor subchannel and bundle tests (PSBT) benchmark was selected for CFD modeling and simulation under various working conditions. The fuel assembly includes three types of pressurized water reactor (PWR) spacer grids: simple grid (SG), nonmixing vane grid (NMVG), and mixing vane grid (MVG). Turbulent flow through subchannels of both nonheated and heated rod bundles was simulated to predict recoverable and nonrecoverable pressure distribution along the length of the bundle. It was observed that vortices were generated at the tips of spacer grids, affecting the cross-flow in subchannels significantly. The estimated pressure loss coefficients were found to be influenced by the flow conditions (Reynolds number or the upstream flow history) and spacer grid configuration. Pressure loss coefficient values ranged from 1.14 to 1.80, depending on the spacer grid type, design, and flow conditions. The CFD method used in this study was demonstrated to have the potential to generate input parameters required for the subchannel analysis and optimization of fuel assembly designs and serve as a surrogate for empirical correlations.

In this study, lattice physics calculations were carried out to evaluate the reactor physics characteristics of different advanced fuel lattices cooled with 7LiOH/NaOH or FLiBe and moderated extern...

Classroom studies of peer-led teaching and mentoring report benefits for students both as teachers and learners. Such benefits include both improved content mastery and personal and professional development. While benefits of peer-led teaching in the clinical setting have been well characterized among other health professions, less is known within undergraduate medical education. In this study, we explored medical students' perceptions and experiences relevant to peer teaching and mentoring in outpatient clinical clerkships.Third-year medical students enrolled in two different longitudinal primary care clerkships, Education Centered Medical Home (ECMH) or Individual Preceptorship (IP), participated in semi-structured interviews in 2018. Students were asked to describe their peer teaching experiences during the clerkship and to reflect on their experiences serving as role models or mentors. We analyzed transcripts utilizing a two-cycle team-based inductive approach.Thirty-three students completed interviews. We derived three main themes: (1) diversity of peer teaching and mentoring opportunities, (2) transitioning one's role from learner to teacher, and (3) personal and professional development. While participants from both clerkships participated in peer teaching and mentoring experiences, ECMH students described more opportunities to interact with students across all years of medical school training, noting that "getting that guidance and in turn being able to teach is a valuable experience." ECMH students further perceived the responsibility of creating a comfortable learning environment for others. Students from both clerkships reflected on 'learning through teaching,' that teaching served as a reaffirmation of the knowledge they gained, and that teaching experience contributed to their personal and professional growth.Students perceived their participation in peer teaching and mentoring experiences in the clinical setting as contributing positively to personal and professional development. Students from both clerkships reflected on their teaching and mentoring opportunities as a facilitator of growth in their own teaching skills; ECMH students further described a heightened sense of self-confidence and fulfillment. These findings highlight the importance of creating learning environments that foster peer teaching and mentoring, as such opportunities may lead to further growth as a learner and as a physician.

As a known phenomenon, crossover between sinus node dysfunction and common atrial tachyarrhythmias-most notably, atrial fibrillation and atrial flutter-in older individuals has previously been seen. Here, we present one of the first case series demonstrating a similar relationship between sinus node dysfunction and much rarer etiologies of tachyarrhythmia-that is, postural tachycardia syndrome and inappropriate sinus tachycardia. The exact pathological mechanisms behind these arrhythmias as well as the observation of concurrent nodal dysfunction are poorly understood. Here, we propose both potential mechanistic pathways as well as an initial treatment algorithm for sinus node dysfunction based upon the existing evidence.

Background Residency programs apply varying criteria to the resident selection process. However, it is unclear which applicant characteristics reflect preparedness for residency. Objective We determined the applicant characteristics associated with first-year performance in internal medicine residency as assessed by performance on Accreditation Council for Graduate Medical Education (ACGME) Milestones. Methods We examined the association between applicant characteristics and performance on ACGME Milestones during intern year for individuals entering Northwestern University's internal medicine residency between 2013 and 2018. We used bivariate analysis and a multivariable linear regression model to determine the association between individual factors and Milestone performance. Results Of 203 eligible residents, 198 (98%) were included in the final sample. One hundred fourteen residents (58%) were female, and 116 residents (59%) were White. Mean Step 1 and Step 2 CK scores were 245.5 (SD 12.0) and 258 (SD 10.8) respectively. Step 1 scores, Alpha Omega Alpha membership, medicine clerkship grades, and interview scores were not associated with Milestone performance in the bivariate analysis and were not included in the multivariable model. In the multivariable model, overall clerkship grades, ranking of the medical school, and year entering residency were significantly associated with Milestone performance (P ≤ .04). Conclusions Most traditional metrics used in residency selection were not associated with early performance on ACGME Milestones during internal medicine residency.

Inclusive education is now advocated as best practice in schools. However, the extent to which adolescents with severe disabilities access the abundant social and academic experiences available in general education classes remains uncertain. We conducted multiple observations of 146 high school students with severe disabilities (including intellectual disability, autism, or multiple disabilities), who were enrolled in at least one general education class. Peer interactions with classmates tended to be very infrequent for most students with severe disabilities. Moreover, rates of peer interaction were the lowest during large-group instruction and when students were sitting next to paraprofessionals or special educators rather than with their peers. Academic engagement also varied across students and was highest during small-group instruction, 1-on-1 work with adults, and when students sat near their peers. Observations of a comparison sample of peers attending these same classes revealed striking overall differences in social and academic participation. We offer recommendations for research and practice aimed at bolstering inclusive education in high schools.

Genomic diversity and past population histories are key considerations in the fields of conservation and evolutionary biology. In this issue of Molecular Ecology Resources, Prasad et al. (Mol. Ecol. Resour., 2021) examine how the quality and phylogenetic divergence of reference genomes influences the outcomes of downstream analyses such as diversity and demographic history inference. Using the beluga whale and rowi kiwi as examples (Figure 1), they systematically estimate heterozygosity, runs of homozygosity (ROH), and demographic history (PSMC) using reference genomes of varying quality and phylogenetic divergence from the target species. They show that demographic history analyses are impacted by phylogenetic distance, although this is not pronounced until divergence exceeds 3% from the target species. Similarly, their results imply that heterozygosity estimates are dependent on phylogenetic distance and the method used to perform the estimates, and ROHs are potentially undetectable when a nonconspecific reference is used. This investigation into the role of divergence and quality of reference genomes highlights the impact and potential biases generated by genome selection on downstream analyses, and provides a possible alternative in cross-species scaffolding in instances where a conspecific reference genome is not available.

Lattice physics and core physics studies have been carried out to investigate the reactor physics feasibility of destroying americium (Am) and curium (Cm) using special target fuel bundles in blank...

A subgroup of postural orthostatic tachycardia syndrome (POTS) patients may also have features of neurocardiogenic syncope (NCS). Syncope and presyncope are predominant clinical features in this subgroup of patients. Asystole has been reported as the cause of some recurrent syncopal episodes following evaluation with an implantable loop recorder (ILR). We present our experience of pacing in a group of patients with POTS and NCS, which resulted in the complete elimination of syncope. We reviewed the charts of 500 patients at the University of Toledo Medical Center from 2003 to 2013 and identified 40 patients who were eligible for inclusion in this study. Patients were included in this study if they had clinical features of POTS and unusually frequent episodes of syncope. All study participants subsequently underwent ILR implantation. Forty patients, including 32 (80%) women, aged 33 ± 13 years were included in this study. All patients demonstrated prolonged asystole (> 6 seconds) or severe bradycardia (heart rate < 30 bpm) during their syncope. Ten patients demonstrated an asystole of more than 10 seconds and also had prolonged and convulsive syncope. All patients had abrupt syncope without any warning signs. All 40 patients underwent dual-chamber pacemaker implantation. Syncope was eliminated in all 40 patients following pacemaker implantation; however, they continued to experience orthostatic tachycardia. Our findings support that dual-chamber pacing may help to eliminate syncope in a subgroup of POTS patients with recurrent syncope and prolonged asystole on ILR.

This paper reports the results of subchannel thermal-hydraulic studies (using the ASSERT-PV code) of the effects of variations and uncertainties in operating/boundary conditions and geometry on the...

Lattice physics and core physics studies have been carried out to investigate the feasibility of destroying long-lived fission products (LLFPs) using special target fuel bundles in blanket fuel cha...

Thermalhydraulic analyses using subchannel codes (e.g., ASSERT-PV) are performed as a support tool to evaluate safety margins and the key parameters. Advanced fuels have recently attracted the international community's interest to improve safety margins during normal operation and accident scenarios by utilizing special coatings and barriers in a heterogeneous, multiregion, multicoating, multiclad annular fuel. In addition, advanced fuels improve the performance characteristics such as a higher burnup and better uranium utilization. Therefore, there is a need to understand the implications of such advanced unconventional fuels for the landscape of the Canadian nuclear industry and Canadian policy for energy development. In this work, subchannel thermalhydraulic analysis of a small modular reactor based on pressurized water reactor technology (PWR-small modular reactor (SMR)) core is performed using ASSERT-PV. A benchmark of a 17 × 17 fuel assembly with conventional fuel elements in comparison to PWR-SMR specification was conducted. The advanced fuel element system is also investigated and compared with the conventional one. The results indicated that the advanced fuel achieves a significant reduction in fuel element temperature by 15%. In addition, the results revealed that the proposed advanced fuel could achieve a minimum critical heat flux ratio (MCHFR) higher than the conventional fuel by 17%.

The development of advanced fuels and fuel cycles for conventional Generation III+ reactors, advanced reactors (such as Generation IV), and small modular reactors will help ensure the long-term sustainability and safety of the use of nuclear energy. Thorium-based fuels are an example of an advanced fuel that could augment and extend uranium resources. As part of previous efforts in Canada to investigate the use of thorium-based fuels for potential use in pressure-tube heavy-water reactors and other technologies, irradiation experiments with various thorium-containing fuels had been conducted in the National Research Universal (NRU) reactor at the Chalk River Laboratories. The NRU reactor physics computational tools and methods, developed initially for conventional enriched uranium fuel, had also been extended for analysis of thorium-based fuel experiments, with most satisfactory results. In this study, a number of physics and operation factors have been analyzed to quantify their effects on the production and burnup of 233U in thorium-based fuel, as well as to improve both the analysis and the use of thorium fuels and fuel cycles.

Newer 'omics approaches, such as metatranscriptomics and metabolomics, allow functional assessments of the interaction(s) between the gut microbiome and the human host. However, in order to generate meaningful data with these approaches, the method of sample collection is critical. Prior studies have relied on expensive and invasive means toward sample acquisition, such as intestinal biopsy, while other studies have relied on easier methods of collection, such as fecal samples that do not necessarily represent those microbes in contact with the host. In this pilot study, we attempt to characterize a novel, minimally invasive method toward sampling the human microbiome using mucosal cytology brush sampling compared to intestinal gut biopsy samples on 5 healthy participants undergoing routine screening colonoscopy. We compared metatranscriptomic analyses between the two collection methods and identified increased taxonomic evenness and beta diversity in the cytology brush samples and similar community transcriptional profiles between the two methods. Metabolomics assessment demonstrated striking differences between the two methods, implying a difference in bacterial-derived versus human-absorbed metabolites. Put together, this study supports the use of microbiome sampling with cytology brushes, but caution must be exercised when performing metabolomics assessment, as this represents differential metabolite production but not absorption by the host.

Physical therapists (PTs) require specialized education and training to increase the capacity and competence of the dementia care workforce. Four areas of critical dementia workforce education and training gaps that apply to the physical therapy profession have been identified, including recruitment/retention, financing and cost of training, interprofessional education, and translation/implementation of effective dementia care. A critical step in developing effective training programs and educational curricula is to understand PTs' and PT students' experiences and views on working with people with dementia (PwD). Therefore, the purpose of this scoping review was to examine the extent and types of evidence that explore the experiences and views of PTs and PT students on the provision of physical therapy services to PwD.The Cochrane Database of Systematic Reviews, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsychINFO, ERIC, PEDro, Web of Science, and Medline databases and sources of gray literature were searched for sources of evidence that met the inclusion criteria of the review protocol. The literature was mapped according to author, participant role, setting, publication type, study design, study aim, key findings, and dementia workforce training gaps addressed.A total of 552 sources of evidence were screened for eligibility, and 16 studies were selected for inclusion. Twelve studies included PTs as participants, and 5 included PT students. Included sources explored PTs' experiences, behaviors, knowledge, attitudes, and confidence in working with PwD and the influence of educational, organizational, and other factors on these domains. Challenges to and strategies for delivering effective care to PwD were examined in multiple sources. The 4 areas of critical dementia workforce education and training gaps were each addressed by at least 1 of the included studies.The current body of literature identifies several gaps in both research and education that need to be addressed before our profession is truly prepared to effectively manage this challenging population of patients with specialized needs.

The use of advanced uranium-based and thorium-based fuel bundles in a 700-MW(electric)–class pressure tube heavy water reactor (PT-HWR) has the potential for improved performance characteristics wi...

A computational benchmark, using the deterministic codes WIMS-AECL and WOBI, and the stochastic code SERPENT, is made for burnup calculations of advanced thorium fuels in heavy water moderated reactors. Exit burnups and the concentration of the longer-lived actinides from the deterministic code set of WIMS-AECL and WOBI, which are 2-D, were compared to those from a full 3-D calculation in SERPENT. Results for reactivity vs. time are in general agreement to within a few mk (

Natural thorium contains impurities of numerous isotopes. A study was performed to examine the influence of naturally occurring impurities in thorium-based fuels on a few parameters of interest such as: exit burnup, coolant void reactivity (CVR), fuel temperature coefficients (FTC), and the radiotoxicity of the used fuel. Two different fuel bundle designs were modeled: a 43-element bundle containing 2.25% U-233, and a 35-element bundle containing 1.45% U-233. Naturally occurring thorium fuel impurities were applied to both fuel bundle models at various concentrations, from 0% to 100% of the expected maximum. For burnup-averaged k-infinity (k∞) values of 1.050 and 1.030, exit burnup, burnup-weighted CVR, and burnup-weighted FTC were calculated using the neutron transport code WIMS-AECL, and plotted against fraction of full impurity concentration to determine how the impurity levels affect these reactor physics parameters of interest. For the most-realistic (for CANDU) burnup-averaged k∞ of 1.050, both the inhalation radiotoxicity and the production of U-232 were calculated using the fuel depletion code WOBI. Up to the maximum impurity concentrations considered, no effects on the investigated fuel performance parameters were found to be greater than a few percent.

The use of advanced uranium-based and thorium-based fuel bundles in pressure tube heavy water reactors (PT-HWRs) has the potential to improve the utilization of uranium resources while also providi...

Variations in the number and arrangement of scutes often are used for species identification in hard-shelled sea turtles. Despite the conserved nature of scute arrangements, anomalous arrangements have been noted in the literature for over a century, with anomalies linked to sub-optimal environmental conditions in the nest during development. Long-held assumptions suggest that anomalous scute arrangements are indicative of underlying physiological or morphological anomalies, with presumed long-term survival costs to the individual. Here, we examined a 25-year photo database of two species of sea turtle (Caretta caretta and Chelonia mydas) captured incidentally and non-selectively on the eastern coast of Florida. Our results suggest that C. mydas is substantially more variable with respect to the arrangement of carapacial scutes, while C. caretta had a relatively higher proportion of individuals with anomalous plastron scute arrangements. We also show evidence that (a) the forms and patterns of anomalous scutes are stable throughout growth; (b) there is limited evidence for selection against non-modal arrangements in the size classes that were examined; and (c) that their frequency has remained stable in juvenile cohorts from 1994 until present. These findings indicate that there may not be a survival cost associated with anomalous scute arrangements once the turtles reach juvenile size classes, and that variation in scute arrangements within populations is relatively common.

Orthostatic intolerance (OI) is a group of disorders characterized by symptoms that occur upon standing and resolve with recumbence. Although well established but not widely recognized, these diagnoses may create uncertainty for clinicians dealing with a patient affected by OI and requiring a surgical procedure. To determine the rate of intra- and postoperative major adverse events in patients with OI undergoing surgery with general anesthesia. The study was a retrospective study of patients with orthostatic intolerance who underwent surgery requiring general anesthesia from 1 January 2000 to 31 December 2018. A total 171 patients with OI underwent 190 surgeries. In patients with POTS and orthostatic-induced VVS, there were no major significant adverse events. There was one episode of AVNRT in a patient with POTS and one episode of bradycardia secondary to vasovagal reflex in a patient with orthostatic-induced VVS. Moreover, there were 13 (6.8%) episodes of postoperative hypotension. However, the majority of these episodes were related to bleeding, volume depletion or sepsis. All cases of hypotension responded well to appropriate therapy. In patients with OH, the rate of postoperative major adverse cardiac events was 4.7%, and the 30-day mortality rate was 6.1%. This is not significantly different from the calculated risk for patients without OH. There were no myocardial infarctions or deaths at 30 days in patients with POTS or orthostatic-induced VVS. Patients with OI may not experience higher rates of perioperative complications compared with patients without OI syndromes.

When results of descriptive functional behavior assessments (FBAs) are inconclusive, experimental analysis methods can be used to directly test hypotheses about when or why a student engages in challenging behavior. Despite growing research on practical variations of hypothesis testing in schools, these methods are rarely incorporated in FBAs in practice. To inform practitioner perspectives on hypothesis testing as a component of FBAs, we surveyed a statewide sample of school practitioners who participate in the FBA process (n = 253). The survey addressed their views on three hypothesis testing strategies (i.e., functional analysis, antecedent analysis, concurrent operant analysis) across several dimensions. On 5-point Likert type scales, participants rated acceptability of procedures, feasibility of implementation, utility of results, conditions in which they would likely use or recommend the strategy, and perceived barriers. We used descriptive and nonparametric statistical analyses to compare ratings among the three hypothesis testing strategies. The majority of participants rated all three strategies favorably with respect to utility. However, ratings on acceptability, feasibility, and barriers were differentiated and favored the concurrent operant analysis over the functional and antecedent analyses. We discuss implications for practice and future research on incorporating hypothesis testing in FBAs for students with persistent challenging behavior.

PURPOSE Infusing continuity of care into medical student clerkships may accelerate professional development, preserve patient-centered attitudes, and improve primary care training. However, prospective, randomized studies of longitudinal curricula are lacking. METHOD All entering Northwestern University Feinberg School of Medicine students in 2015 and 2016 were randomized to the Education Centered Medical Home (ECMH), a 4-year, team-based primary care clerkship; or a mentored individual preceptorship (IP) for 2 years followed by a traditional 4-week primary care clerkship. Students were surveyed 4 times (baseline, M1, M2, and M3 year [through 2018]); surveys included the Maslach Burnout Inventory (MBI); the Communication, Curriculum, and Culture (C3) survey assessing the hidden curriculum; and the Attitudes Toward Health Care Teams (ATHCT) scale. The authors analyzed results using an intent-to-treat approach. RESULTS Three hundred twenty-nine students were randomized; 316 (96%) participated in surveys. Seventy percent of all respondents would recommend the ECMH to incoming first-year students. ECMH students reported a more positive learning environment (overall quality, 4.4 ECMH vs 4.0 IP, P < .001), greater team-centered attitudes (ATHCT scale, 3.2 vs 3.0, P = .007), less exposure to negative aspects of the hidden curriculum (C3 scale, 4.6 vs 4.3, P < .001), and comparable medical knowledge acquisition. ECMH students established more continuity relationships with patients (2.2 vs 0.3, P < .001) and reported significantly higher professional efficacy (MBI-PE, 4.1 vs 3.9, P = .02). CONCLUSIONS In this randomized medical education trial, the ECMH provided superior primary care training across multiple outcomes compared with a traditional clerkship-based model, including improved professional efficacy.

The number of patients with implantable electronic cardiac devices is continuously increasing. As more pacemakers and implantable cardioverter-defibrillators (ICDs) are being placed, a basic understanding of some troubleshooting for devices is becoming essential. Loss of capture can be an emergent presentation for an unstable patient and can be encountered intermittently in hospitalized patients. There are many causes for a loss of capture, with the timing of the implant having a high correlation with certain causes over others. The most common acute cause just after the insertion procedure is lead dislodgement or malposition. In comparison, an increase in the required threshold promoting a loss of capture can happen after months to years of insertion of the pacemaker or ICD. This change can be due to a cardiomyopathy, fibrosis medications, metabolic imbalance, lead fracture, or an exit block. Loss of capture can also occur from external electrical stimuli and inappropriate pacemaker or ICD settings. Further, there are also potential noncardiac causes, such as medications, electrolyte imbalance, and acidemia. A knowledge of these factors is essential for health care providers, given the morbidity and mortality that can potentially be associated with device-related issues, especially in patients who are dependent on the included pacing function.