An extremely energetic cosmic ray observed by a surface detector array

Cosmic rays are energetic charged particles from extraterrestrial sources, with the highest-energy events thought to come from extragalactic sources. Their arrival is infrequent, so detection requires instruments with large collecting areas. In this work, we report the detection of an extremely energetic particle recorded by the surface detector array of the Telescope Array experiment. We calculate the particle's energy as [Formula: see text] (~40 joules). Its arrival direction points back to a void in the large-scale structure of the Universe. Possible explanations include a large deflection by the foreground magnetic field, an unidentified source in the local extragalactic neighborhood, or an incomplete knowledge of particle physics.

Relationships between Physiological and Self-Reported Assessment of Cancer-Related Fatigue

The purpose of this study was to evaluate the relationships between subjective, self-reported cancer related fatigue (CRF) and objective measures of muscular strength and fatigability in cancer survivors. A total of 155 cancer survivors (60 ± 13 years of age) completed a questionnaire for the assessment of CRF, along with assessments of handgrip strength, quadriceps strength and fatigability (reduced force/torque). Fatigability was measured by completing 15 maximal isokinetic contractions of the knee extensors (QFI). Spearman's rho correlation coefficients were calculated as pairwise combinations of the numerical and categorical dependent measures. Categorical variables were analyzed via nonparametric means of association. This included a 4×4 chi-square to test whether cancer stage (0-4) was independent of fatigue status (none, mild, moderate, severe) and whether cancer treatment (surgery, radiation, chemotherapy, or combinations of these) was independent of fatigue status. None of the physiological strength and fatigue measures were significantly correlated to overall perceived fatigue or any of the subscales. Cancer stage and treatment type were also not significantly related to fatigue status (likelihood ratio = .225, Cramer's V = .228; likelihood ratio = .103, Cramer's V = .369, respectively). Our results show that levels of patient reported fatigue severity were not significantly related to muscular fatigability or strength. As a result, cancer patients experiencing fatigue may benefit from following the standard exercise guidelines for cancer survivors, regardless of their levels of self-reported fatigue.

Characterizing behavior change techniques used in the self-management of binge eating and weight: Applying a user-centered design approach

User-centered design methods aim to increase intervention engagement by focusing on consumers' needs and preferences. We conducted a needs assessment (the first step in user-centered design) via a digital diary study to understand how individuals with recurrent binge eating (≥12 episodes in 3 months) and obesity (BMI ≥30 kg/m2) manage these problems in their day-to-day lives and the approaches they use to change their behavior. Specifically, we applied the Behavior Change Technique (BCT)-Taxonomy to characterize which standardized BCTs individuals use to change binge eating and health-related behaviors and their motivations to use them, to inform the design of a mobile intervention. We analyzed qualitative data from 22 adults (64% female, 32% White) who submitted 176 diary entries. For each entry, we coded the BCTs used, motivation for use, and whether the BCT(s) were perceived as beneficial for behavior change. Across participants, investigators identified 50 of the 93 standardized BCTs (54%). Each participant used an average of 12 (SD = 4) BCTs, most commonly Behavior Substitution (72.3%), Distraction (68.2%), Goal Setting (Behavior) (63.6%), Action Planning (59.1%) and Adding Objects to the Environment (59.1%). More BCTs were coded as beneficial (49%) versus detrimental (24%) or neutral (27%). Techniques were most commonly motivated by preventing binge eating (95.5%), losing weight (95.5%), reducing unhealthy food choices (90.9%), or managing stress (59.1%). Results help inform how interventions could be designed to support consumers in changing binge eating and weight-related behaviors, although such designs would need to be tested for their impact on engagement and outcomes.

CSL112 (human apolipoprotein A-I) infusion rapidly increases apoA-I exchange rate (AER) when administered to patients post myocardial infarction

Background

Cholesterol efflux capacity (CEC) measured using patient serum and cultured macrophages is considered a biomarker of high-density lipoprotein (HDL) functionality. This parameter is inversely related to incident cardiovascular events and declines in the days post-acute myocardial infarction (AMI). The apolipoprotein A-I (apoA-I) exchange rate (AER) may represent an alternative, clinically amenable cell-free measure of CEC, which has also been associated with incident cardiovascular events (1).

Purpose

To characterise the effects of human apoA-I (CSL112) infusion on AER over 48 hours when administered post AMI.

Methods

This analysis included 50 patients with available samples from the AEGIS-I (ApoA-I Event Reducing in Ischemic Syndromes I) randomized, double-blind, placebo-controlled, phase 2b pharmacokinetic/pharmacodynamic sub-study (2). Patients were randomized to receive four weekly infusions of either placebo (n=16), 2g (n=19) or 6g (n=15) CSL112 post AMI. Blood samples were drawn at baseline and at 2, 4, 6, 12, 24 and 48 hours post the first and fourth infusion for measurement of AER (1) as well as CEC (total, ABCA1 dependent and ABCA1 independent CEC) as previously described (3).

Results

CSL112 infusion increased AER dose-dependently, peaking at 2h (end of infusion) and returning to baseline by 24h post infusion (Figure 1). AER was significantly correlated with CEC (total, ABCA1 dependent and independent), HDL-cholesterol, apoA-I and phosphatidylcholine across all timepoints and similarly after both infusions (Table 1).

Conclusion

Infusion of CSL112 increased AER in a dose-dependent manner post AMI and may represent a clinically amenable biomarker of HDL functionality.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): CSL Ltd, Parkville, Australia Figure 1. Left: Time course data expressed as mean ± SEM and adjusted for baseline prior to each infusion. Using a linear mixed model for repeated measures, the 6g dose increased AER from baseline at timepoints from 2–12 hours (p<0.001), whereas the 2gm dose only increased AER between 2–6 hours (p<0.05). Right: Boxplots showing median, quartiles and min/max of Area Under the Curve (AUC) from 0–24 hours post infusion. Using one-way ANOVA the 6 g dose was significantly higher than placebo (p<0.05).Table 1

Evaluation of heavy-duty vehicle emission controls with a decade of California real-world observations

Over the past decade, efforts to reduce emissions of particulate matter (PM) and oxides of nitrogen (NO + NO₂, or NO_x) from heavy-duty diesel vehicles (HDDVs) have led to the widespread adoption of both Diesel Particulate Filters (DPFs) to control PM and Selective Catalytic Reduction (SCR) to control NO_x. We evaluated the performance of DPFs and SCR with 13,327 real-world fuel-based Black Carbon (BC) and NO_x emission factors from 9,167 unique heavy-duty vehicles (primarily HDDVs) measured at four sites in California (two ports, two highways) from 2011 to 2018. BC emission factors have decreased by 90% during the past decade. At the same time, BC distributions have become increasingly skewed toward "high-emitters" - e.g., the portion of the HDDV fleet responsible for half of all BC emissions has decreased from ~16% to ~3%. NO_x emission factors have also decreased over the past decade, but by only 31%. They remain roughly five times greater than in-use thresholds.We examined changes in BC and NO_x emissions with engine age. BC emissions from DPF-only trucks decreased slightly but insignificantly, by 6 ± 15 mg/kg fuel per year, while for DPF+SCR trucks they increased by 5 ± 3. These changes are less than 5% of in-use thresholds. The annual increase in NO_x emissions with age was much greater: 1.44 ± 0.28 g/kg for older SCR trucks without on-board diagnostic (OBD) capabilities and 0.48 ± 0.35 for newer trucks with OBD, roughly 20- 50% of in-use thresholds. Paired t-tests on the over 600 vehicles that were observed in multiple campaigns were consistent with these results. Observed changes in BC emissions with age were best fit with a "gross emitter" model assuming an annual DPF failure rate of 0.83 ± 0.01% for DPF-only trucks and 0.56 ± 0.01% for DPF+SCR trucks.Implications: These observations of real-world HDV emission factors have several major implications for regulatory efforts to reduce them. The increasing importance of a relatively small number of high BC emitters suggests that widespread sampling of the on-road fleet will be necessary to identify these vehicles. On the other hand, the much more ubiquitous deterioration in NO_x control measures may be better addressed by incorporating on-board diagnostic systems, with telematic data transfer when possible, into inspection and maintenance programs. These NO_x observations also highlight the need for strengthening heavy-duty SCR durability demonstration requirements.

Exercise training improves postural steadiness in cancer survivors undergoing chemotherapy

BACKGROUND

Cancer and cancer treatments negatively affect somatosensory, vestibular, and visual inputs that regulate postural stability and balance, increasing the risk of falling. Exercise training has been shown to mitigate other negative side effects of cancer treatments, such as reducing peripheral neuropathy.

RESEARCH QUESTION

How does 12 weeks of supervised exercise training influence postural stability in cancer survivors who receive chemotherapy?

METHODS

Postural stability of cancer survivors (n = 25; mass = 79.0 ± 22.6 kg; height = 1.66 ± 0.08 m; age = 61 ± 10 years) receiving chemotherapy was assessed prior to and following a 12-week individualized exercise training program by quantifying changes in center of pressure data. A series of 2-factor (pre/post x condition) analysis of variance with repeated measures were used to identify differences between conditions and pre- and post- training program on time and frequency domain measures.

RESULTS

Mediolateral root mean square excursion (p = 0.040; es = 0.20) and resultant mean frequency (p = 0.044; es = 0.29) of the center of pressure trajectory were found to be significantly different between pre- and post-training program. Further, participants dealt better with perturbations after completing the training program by reducing mediolateral root mean square excursion and 95 % confidence ellipse when visual stimulus was removed.

SIGNIFICANCE

Supervised exercise training in cancer patients undergoing chemotherapy improves postural stability in the mediolateral direction. Given that mediolateral movement of the center of pressure has previously been associated with fallers in other populations, exercise training during cancer treatments may be beneficial.

Optimizing Health Information Technologies for Symptom Management in Cancer Patients and Survivors: Usability Evaluation

Background

Unmanaged cancer symptoms and treatment-related side effects can compromise long-term clinical outcomes and health-related quality of life. Health information technologies such as web-based platforms offer the possibility to supplement existing care and optimize symptom management.

Objective

This paper describes the development and usability of a web-based symptom management platform for cancer patients and survivors that will be implemented within a large health system.

Methods

A web-based symptom management platform was designed and evaluated via one-on-one usability testing sessions. The System Usability Scale (SUS), After Scenario Questionnaire (ASQ), and qualitative analysis of semistructured interviews were used to assess program usability.

Results

Ten cancer survivors and five cancer center staff members participated in usability testing sessions. The mean score on the SUS was 86.6 (SD 14.0), indicating above average usability. The mean score on the ASQ was 2.5 (SD 2.1), indicating relatively high satisfaction with the usability of the program. Qualitative analyses identified valued features of the program and recommendations for further improvements.

Conclusions

Cancer survivors and oncology care providers reported high levels of acceptability and usability in the initial development of a web-based symptom management platform for cancer survivors. Future work will test the effectiveness of this web-based platform.

Translating evidence-based parenting programs for primary care: Stakeholder recommendations for sustainable implementation

AIMS

To translate evidence-based programs (EBP) for a new setting, attention must be given to the characteristics of the intervention and the local setting, as well as evidence that is compelling to decision-makers. This paper describes the history of a partnership and stakeholder recommendations to inform the adaptation of an EBP for primary care.

METHODS

We established a community advisory board (CAB) consisting of stakeholders with expertize in primary care delivery. A thematic analysis was conducted with fieldnotes and transcriptions from CAB meetings and regular meetings with participating clinics.

RESULTS

We found that (a) parenting programs with a focus on behavioral and physical health are appropriate for this setting, (b) variability in the structure of primary care means implementation must be tailorable, and (c) financial and organizational outcomes are compelling for decision-makers.

CONCLUSION

Factors related to the content and structure of evidence-based programs are uniquely related to distinct implementation outcomes of interest to key stakeholders.

Biomechanical analysis of curb ascent in persons with Ertl and non-Ertl transtibial amputations

BACKGROUND

Persons with transtibial amputation report curb negotiation is more challenging than negotiating stairs. It is unknown if amputation technique influences curb negotiation ability. Traditional transtibial amputation surgical techniques do not join the distal tibia and fibula (non-Ertl), whereas a transtibial osteomyoplastic amputation (Ertl) creates a "bone bridge" connection. The Ertl may facilitate ambulation through greater residual end load bearing.

OBJECTIVES

To determine if ability to negotiate a curb differs between Ertl and non-Ertl groups.

STUDY DESIGN

Cross-sectional study.

METHODS

Non-Ertl (n = 7) and Ertl (n = 5) participants ascended a 16-cm curb using their amputated and intact limb as the lead limb. Motion data and ground reaction forces were used to calculate ankle, knee, hip, and total limb work for ground and curb steps.

RESULTS

On the ground, the amputated limb of both groups produced less work than the intact limb. In contrast, on the curb step, the Ertl amputated limb generated more net hip work than the non-Ertl amputated limb. As a result, the net limb work of the Ertl amputated limb did not differ from the non-amputated limbs.

CONCLUSION

Comparisons between the amputated limb of Ertl and non-Ertl groups suggest use of a different curb stepping pattern between groups.

CLINICAL RELEVANCE

These findings suggest that surgical technique may influence curb negotiation ability in individuals with transtibial amputation. Specifically, the Ertl group is able to produce more hip power than the non-Ertl group while negotiation a curb which may be attributed to the increased ability to end-load bear on the residual limb.

PM2.5 on the London Underground

INTRODUCTION

Despite the London Underground (LU) handling on average 2.8 million passenger journeys per day, the characteristics and potential health effects of the elevated concentrations of metal-rich PM2.5 found in this subway system are not well understood.

METHODS

Spatial monitoring campaigns were carried out to characterise the health-relevant chemical and physical properties of PM2.5 across the LU network, including diurnal and day-to-day variability and spatial distribution (above ground, depth below ground and subway line). Population-weighted station PM2.5 rankings were produced to understand the relative importance of concentrations at different stations and on different lines.

RESULTS

The PM2.5 mass in the LU (mean 88 μg m-3, median 28 μg m-3) was greater than at ambient background locations (mean 19 μg m-3, median 14 μg m-3) and roadside environments in central London (mean 22 μg m-3, median 14 μg m-3). Concentrations varied between lines and locations, with the deepest and shallowest submerged lines being the District (median 4 μg m-3) and Victoria (median 361 μg m-3 but up to 885 μg m-3). Broadly in agreement with other subway systems around the world, sampled LU PM2.5 comprised 47% iron oxide, 7% elemental carbon, 11% organic carbon, and 14% metallic and mineral oxides. Although a relationship between line depth and air quality inside the tube trains was evident, there were clear influences relating to the distance from cleaner outside air and the exchange with cabin air when the doors open. The passenger population-weighted exposure analysis demonstrated a method to identify stations that should be prioritised for remediation to improve air quality.

CONCLUSION

PM2.5 concentrations in the LU are many times higher than in other London transport Environments. Failure to include this environment in epidemiological studies of the relationship between PM2.5 and health in London is therefore likely to lead to a large exposure misclassification error. Given the significant contribution of underground PM2.5 to daily exposure, and the differences in composition compared to urban PM2.5, there is a clear need for well-designed studies to better understand the health effects of underground exposure.

Real-time particulate emissions rates from active and passive heavy-duty diesel particulate filter regeneration

Periodic regeneration is required to clean the diesel particulate filter (DPF) of heavy-duty diesel vehicle. In this study we analyze real-time particulate matter (PM) mass, particle number, and black carbon emissions during steady state driving active and passive diesel particulate filter (DPF) regenerations on a heavy-duty chassis dynamometer. Regeneration PM emissions were dominated by particles with count median diameter<100nm, with the majority <50nm. Results indicate that vehicle activity during DPF loading significantly affects regeneration particulate emissions. Average PM emission rates (gPM/h) from the 2010 MY vehicle were higher than the 2007 MY vehicle during all regeneration conditions in this study. Sequential forced-active regenerations resulted in reduced particulate mass emissions, but not in reduced particle number emissions, suggesting incomplete stored PM removal or effects of after-treatment fuel injection. Black carbon emission factors (EF_BC) were 3.4 and 21 times larger during driving-active regeneration than during a 50 mph steady state cruise with a recently regenerated DPF for the 2007 and 2010 MY vehicle, respectively. Real-time PM emissions rates were lower during passive regeneration of the 2010 MY DPF, suggesting more modern passive regeneration technologies reduce total on-road particulate and ultrafine particulate emissions.

Obese adults walk differently in shoes than while barefoot

BACKGROUND

Some comparisons between walking gait of obese and non-obese adults have been made during barefoot conditions, and others while shod. Methodological differences, footwear conditions, and gait speed disparities among the research done on overweight individuals were the factors motivating the present study.

RESEARCH QUESTION

The present study was designed to compare gait kinematics and kinetics of obese adults between two footwear conditions (barefoot versus shod) at a set walking speed.

METHODS

Ten obese (body mass index > 30 kg.m^-2), but otherwise healthy adults (age = 26 ± 3 years, height = 1.79 ± 0.10 m, mass = 108.46 ± 13.25 kg) participated in this study. Ground reaction forces and 3D kinematic data were simultaneously collected as participants walked overground at 1.5 m.s^-1 in barefoot and shod conditions.

RESULTS

Walking barefoot reduced ankle, knee, and hip ranges of motion, and stride length, stance time, and double support time were also reduced. Kinetic outcomes included smaller peak vertical and anterior-posterior ground reaction forces and knee joint moments while barefoot.

SIGNIFICANCE

Footwear condition significantly influences key gait variables in obese adults. Conflicting conclusions from previous investigations of gait in obese adults may be a consequence of differing footwear conditions.

Implementation Research Methodologies for Achieving Scientific Equity and Health Equity

Implementation science has great potential to improve the health of communities and individuals who are not achieving health equity. However, implementation science can exacerbate health disparities if its use is biased toward entities that already have the highest capacities for delivering evidence-based interventions. In this article, we examine several methodologic approaches for conducting implementation research to advance equity both in our understanding of what historically disadvantaged populations would need-what we call scientific equity-and how this knowledge can be applied to produce health equity. We focus on rapid ways to gain knowledge on how to engage, design research, act, share, and sustain successes in partnership with communities. We begin by describing a principle-driven partnership process between community members and implementation researchers to overcome disparities. We then review three innovative implementation method paradigms to improve scientific and health equity and provide examples of each. The first paradigm involves making efficient use of existing data by applying epidemiologic and simulation modeling to understand what drives disparities and how they can be overcome. The second paradigm involves designing new research studies that include, but do not focus exclusively on, populations experiencing disparities in health domains such as cardiovascular disease and co-occurring mental health conditions. The third paradigm involves implementation research that focuses exclusively on populations who have experienced high levels of disparities. To date, our scientific enterprise has invested disproportionately in research that fails to eliminate health disparities. The implementation research methods discussed here hold promise for overcoming barriers and achieving health equity.

Application of the Theoretical Domains Framework to identify factors that influence hand hygiene compliance in long-term care

BACKGROUND

Healthcare worker (HCW) hand hygiene compliance is key to patient safety; however, compliance is suboptimal. Nevertheless hand hygiene compliance is not well studied in the long-term care setting.

AIM

To apply a behaviour change framework, the Theoretical Domains Framework (TDF), to identify modifiable facilitators and barriers for HCW hand hygiene compliance in long-term care settings.

METHODS

HCW hand hygiene compliance facilitators and barriers were examined using a questionnaire for HCWs from long-term care homes in Ontario, Canada. The questionnaire was informed by the TDF, which is based on a synthesis of constructs from a number of relevant psychological theories of behaviour change.

FINDINGS

Barriers identified from the questionnaire aligned with the TDF domain environmental context and resources (time pressure, workload, and environmental controls). Facilitators identified from questionnaire results aligned with the TDF domains social/professional role and identity (it is what is expected of HCWs), and beliefs about consequences (risk of transmission of micro-organisms to self or others).

CONCLUSION

There are several barriers to hand hygiene compliance that persist in long-term care. A behaviour change theory-informed framework such as the TDF can be helpful to identify those barriers. This study identified several key behavioural constructs aligned with the TDF that can be targeted when developing novel hand hygiene interventions.

Deriving fuel-based emission factor thresholds to interpret heavy-duty vehicle roadside plume measurements

Remote sensing devices have been used for decades to measure gaseous emissions from individual vehicles at the roadside. Systems have also been developed that entrain diluted exhaust and can also measure particulate matter (PM) emissions. In 2015, the California Air Resources Board (CARB) reported that 8% of in-field diesel particulate filters (DPF) on heavy-duty (HD) vehicles were malfunctioning and emitted about 70% of total diesel PM emissions from the DPF-equipped fleet. A new high-emitter problem in the heavy-duty vehicle fleet had emerged. Roadside exhaust plume measurements reflect a snapshot of real-world operation, typically lasting several seconds. In order to relate roadside plume measurements to laboratory emission tests, we analyzed carbon dioxide (CO₂), oxides of nitrogen (NO_X), and PM emissions collected from four HD vehicles during several driving cycles on a chassis dynamometer. We examined the fuel-based emission factors corresponding to possible exceedances of emission standards as a function of vehicle power. Our analysis suggests that a typical HD vehicle will exceed the model year (MY) 2010 emission standards (of 0.2 g NO_X/bhp-hr and 0.01 g PM/bhp-hr) by three times when fuel-based emission factors are 9.3 g NO_X/kg fuel and 0.11 g PM/kg using the roadside plume measurement approach. Reported limits correspond to 99% confidence levels, which were calculated using the detection uncertainty of emissions analyzers, accuracy of vehicle power calculations, and actual emissions variability of fixed operational parameters. The PM threshold was determined for acceleration events between 0.47 and 1.4 mph/sec only, and the NO_X threshold was derived from measurements where after-treatment temperature was above 200°C. Anticipating a growing interest in real-world driving emissions, widespread implementation of roadside exhaust plume measurements as a compliment to in-use vehicle programs may benefit from expanding this analysis to a larger sample of in-use HD vehicles.

IMPLICATIONS

Regulatory agencies, civil society, and the public at large have a growing interest in vehicle emission compliance in the real world. Leveraging roadside plume measurements to identify vehicles with malfunctioning emission control systems is emerging as a viable new and useful method to assess in-use performance. This work proposes fuel-based emission factor thresholds for PM and NOx that signify exceedances of emission standards on a work-specific basis by analyzing real-time emissions in the laboratory. These thresholds could be used to prescreen vehicles before roadside enforcement inspection or other inquiry, enhance and further develop emission inventories, and potentially develop new requirements for heavy-duty inspection and maintenance (I/M) programs, including but not limited to identifying vehicles for further testing.

Formation and Evolution of aqSOA from Aqueous-Phase Reactions of Phenolic Carbonyls: Comparison between Ammonium Sulfate and Ammonium Nitrate Solutions

We investigate the effects of sulfate and nitrate on the formation and evolution of secondary organic aerosol formed in the aqueous phase (aqSOA) from photooxidation of two phenolic carbonyls emitted from wood burning. AqSOA was formed efficiently from the photooxidation of both syringaldehyde (C₉H₁₀O₄) and acetosyringone (C₁₀H₁₂O₄) in ammonium sulfate and ammonium nitrate solutions, with mass yields ranging from 30% to 120%. Positive matrix factorization on the organic mass spectra acquired by an Aerosol Mass Spectrometer revealed a combination of functionalization, oligomerization, and fragmentation processes in the chemical evolution of aqSOA. Functionalization and oligomerization dominated in the first 4 h of reaction, with phenolic oligomers and their derivatives significantly contributing to aqSOA formation; and oxidation of the first-generation products led to an abundance of oxygenated ring-opening products. Degradation rates of syringaldehyde and acetosyringone in nitrate solutions were 1.5 and 3.5 times faster than rates in sulfate solutions, and aqSOA yields in nitrate experiments are twice as high as in sulfate experiments. Nitrate likely promoted the reactions because it is a photolytic source of OH radicals, while sulfate is not, highlighting the importance of aerosol-phase nitrate in the formation of aqSOA by facilitating the photooxidation of organic precursors.

Emissions During and Real-world Frequency of Heavy-duty Diesel Particulate Filter Regeneration

Recent tightening of particulate matter (PM) emission standards for heavy-duty engines has spurred the widespread adoption of diesel particulate filters (DPFs), which need to be regenerated periodically to remove trapped PM. The total impact of DPFs therefore depends not only on their filtering efficiency during normal operation, but also on the emissions during and the frequency of regeneration events. We performed active (parked and driving) and passive regenerations on two heavy-duty diesel vehicles (HDDVs), and report the chemical composition of emissions during these events, as well as the efficiency with which trapped PM is converted to gas-phase products. We also collected activity data from 85 HDDVs to determine how often regeneration occurs during real-world operation. PM emitted during regeneration ranged from 0.2 to 16.3 g, and the average time and distance between real-world active regenerations was 28.0 h and 599 miles. These results indicate that regeneration of real-world DPFs does not substantially offset the reduction of PM by DPFs during normal operation. The broad ranges of regeneration frequency per truck (3-100 h and 23-4078 miles) underscore the challenges in designing engines and associated aftertreatments that reduce emissions for all real-world duty cycles.

Recent H- diagnostics, plasma simulations, and 2X scaled Penning ion source developments at the Rutherford Appleton Laboratory

A vessel for extraction and source plasma analyses is being used for Penning H^- ion source development at the Rutherford Appleton Laboratory. A new set of optical elements including an einzel lens has been installed, which transports over 80 mA of H^- beam successfully. Simultaneously, a 2X scaled Penning source has been developed to reduce cathode power density. The 2X source is now delivering a 65 mA H^- ion beam at 10% duty factor, meeting its design criteria. The long-term viability of the einzel lens and 2X source is now being evaluated, so new diagnostic devices have been installed. A pair of electrostatic deflector plates is used to correct beam misalignment and perform fast chopping, with a voltage rise time of 24 ns. A suite of four quartz crystal microbalances has shown that the cesium flux in the vacuum vessel is only increased by a factor of two, despite the absence of a dedicated cold trap. Finally, an infrared camera has demonstrated good agreement with thermal simulations but has indicated unexpected heating due to beam loss on the downstream electrode. These types of diagnostics are suitable for monitoring all operational ion sources. In addition to experimental campaigns and new diagnostic tools, the high-performance VSim and COMSOL software packages are being used for plasma simulations of two novel ion thrusters for space propulsion applications. In parallel, a VSim framework has been established to include arbitrary temperature and cesium fields to allow the modeling of surface physics in H^- ion sources.

Ertl and Non-Ertl amputees exhibit functional biomechanical differences during the sit-to-stand task

BACKGROUND

People with transtibial amputation stand ~50times/day. There are two general approaches to transtibial amputation: 1) distal tibia and fibula union using a "bone-bridge" (Ertl), 2) non-union of the tibia and fibula (Non-Ertl). The Ertl technique may improve functional outcomes by increasing the end-bearing ability of the residual limb. We hypothesized individuals with an Ertl would perform a five-time sit-to-stand task faster through greater involvement/end-bearing of the affected limb.

METHODS

Ertl (n=11) and Non-Ertl (n=7) participants sat on a chair with each foot on separate force plates and performed the five-time sit-to-stand task. A symmetry index (intact vs affected limbs) was calculated using peak ground reaction forces.

FINDINGS

The Ertl group performed the task significantly faster (9.33s (2.66) vs 13.27 (2.83)s). Symmetry index (23.33 (23.83)% Ertl, 36.53 (13.51)% Non-Ertl) indicated the intact limb for both groups produced more force than the affected limb. Ertl affected limb peak ground reaction forces were significantly larger than the Non-Ertl affected limb. Peak knee power and net work of the affected limb were smaller than their respective intact limb for both groups. The Ertl intact limb produced significantly greater peak knee power and net work than the Non-Ertl intact knee.

INTERPRETATION

Although loading asymmetries existed between the intact and affected limb of both groups, the Ertl group performed the task ~30% faster. This was driven by greater power and work production of the Ertl intact limb knee. Our results suggest that functional differences exist between the procedures.

Belatacept and Eculizumab for Treatment of Calcineurin Inhibitor-induced Thrombotic Microangiopathy After Kidney Transplantation: Case Report

Thrombotic microangiopathy (TMA) after kidney transplantation is an uncommon and challenging cause of graft dysfunction and is associated with early graft loss. An idiosyncratic endothelial reaction to calcineurin inhibitors (CNIs) has been implicated as a frequent cause of TMA. This reaction is marked by uncontrolled activation of complement and subsequent cellular destruction. Usual therapy consists of withdrawal of the inciting drug and plasmapheresis to minimize levels of circulating complement. Recently, eculizumab, a monoclonal antibody to complement component C5, has been used for the treatment of atypical hemolytic uremic syndrome. Belatacept, an inhibitor of T cell costimulatory protein CTLA-4 has been used in immunosuppression strategies aimed at minimization of CNI. Here we report the first case of treatment of CNI-associated TMA/hemolytic uremic syndrome with withdrawal of tacrolimus and initiation of both belatacept and eculizumab. The case describes a favorable clinical course for both graft and patient, and is accompanied by a review of the literature.

Effects of load carriage and footwear on lower extremity kinetics and kinematics during overground walking

Kinetic and kinematic responses during walking vary by footwear condition. Load carriage also influences gait patterns, but it is unclear how an external load influences barefoot walking. Twelve healthy adults (5 women, 7 men) with no known gait abnormalities participated in this study (age=23±3years, height=1.73±0.11m, and mass=70.90±12.67kg). Ground reaction forces and 3D motion were simultaneously collected during overground walking at 1.5ms^-1 in four conditions: Barefoot Unloaded, Shod Unloaded, Barefoot Loaded, and Shod Loaded. Barefoot walking reduced knee and hip joint ranges of motion, as well as stride length, stance time, swing time, and double support time. Load carriage increased stance and double support times. The 15% body weight load increased GRFs ∼15%. Walking barefoot reduced peak anteroposterior GRFs but not peak vertical GRFs. Load carriage increased hip, knee, and ankle joint moments and powers, while walking barefoot increased knee and hip moments and powers. Thus, spatiotemporal and kinematic adjustments to walking barefoot decrease GRFs but increase knee and hip kinetic measures during overground walking. The ankle seems to be less affected by these footwear conditions. Regardless of footwear, loading requires larger GRFs, joint loads, and joint powers.

Practical Rotary Encoder Accuracy Limits for Transmission Error Measurement

Errors of angular position on encoders used for transmission error measurement were investigated to determine the practical limits of accuracy. Computer correction can be used to eliminate consistent errors on the encoders but errors remain, attributable to electrical noise, bearing errors and friction effects. Practical limits on the calibration and usage of the encoders for individual harmonics of once per revolution frequency and for a given angular position were established.

Alias Errors in Precision Rotary Encoder Calibration

Discrepancies between errors measured by back-to-back tests on rotary encoders and the errors quoted by the manufacturers led to investigation of the causes for the difference. An error that was apparently at 96 cycles per revolution was found to be due to a much higher frequency which was well outside the normal operating range for transmission error work.

Statin-induced expression change of INSIG1 in lymphoblastoid cell lines correlates with plasma triglyceride statin response in a sex-specific manner

Statins are widely prescribed to lower plasma low-density lipoprotein (LDL) cholesterol levels. They also modestly reduce plasma triglyceride (TG), an independent cardiovascular disease risk factor, in most people. The mechanism and inter-individual variability of TG statin response is poorly understood. We measured statin-induced gene expression changes in lymphoblastoid cell lines derived from 150 participants of a simvastatin clinical trial and identified 23 genes (false discovery rate, FDR=15%) with expression changes correlated with plasma TG response. The correlation of insulin-induced gene 1 (INSIG1) expression changes with TG response (rho=0.32, q=0.11) was driven by men (interaction P=0.0055). rs73161338 was associated with INSIG1 expression changes (P=5.4 × 10⁻⁵) and TG response in two statin clinical trials (P=0.0048), predominantly in men. A combined model including INSIG1 expression level and splicing changes accounted for 29.5% of plasma TG statin response variance in men (P=5.6 × 10⁻⁶). Our results suggest that INSIG1 variation may contribute to statin-induced changes in plasma TG in a sex-specific manner.

Boundary-Layer Effects on Acoustic Transmission Through Narrow Slit Cavities

We explore the slit-width dependence of the resonant transmission of sound in air through both a slit array formed of aluminum slats and a single open-ended slit cavity in an aluminum plate. Our experimental results accord well with Lord Rayleigh's theory concerning how thin viscous and thermal boundary layers at a slit's walls affect the acoustic wave across the whole slit cavity. By measuring accurately the frequencies of the Fabry-Perot-like cavity resonances, we find a significant 5% reduction in the effective speed of sound through the slits when an individual viscous boundary layer occupies only 5% of the total slit width. Importantly, this effect is true for any airborne slit cavity, with the reduction being achieved despite the slit width being on a far larger scale than an individual boundary layer's thickness. This work demonstrates that the recent prevalent loss-free treatment of narrow slit cavities within acoustic metamaterials is unrealistic.

Effects of load carriage and footwear on spatiotemporal parameters, kinematics, and metabolic cost of walking

Gait patterns are commonly altered when walking or running barefoot compared to shod conditions. Although controversy exists as to whether barefoot conditions result in lower metabolic costs, it is clear that adding load to the body results in increased metabolic costs. The effects of footwear and backpack loading have been investigated separately, but it is unclear whether manipulating both simultaneously would cause similar outcomes. Twelve healthy individuals (7 female, 5 male) with no obvious gait abnormalities participated in this study (age=24±2 years, height=1.73±0.13 m, and mass=71.1±16.9 kg). Steady state metabolic data and 3D motion capture were collected during treadmill walking at 1.5 ms(-1) in four conditions: Barefoot Unloaded, Shod Unloaded, Barefoot Loaded, and Shod Loaded. Barefoot walking elicited shorter stride lengths, stance and double support times, as well as a slight (≈1%), but not significant, decrease in metabolic cost. Loading increased metabolic costs of walking but did not elicit spatiotemporal changes in either footwear condition. Lower limb kinematic differences were noted in response to both loading and footwear. Changes in spatiotemporal parameters observed when walking barefoot were not exacerbated by the addition of a backpack load. This suggests that the increased metabolic demand associated with the load is met with a similar spatiotemporal pattern whether a person wears a supportive shoe or not. Thus, the discomfort associated with foot strike while barefoot that promotes spatiotemporal changes seems to be independent of load.

Nosocomial Mycobacterial Pseudoinfection in a Georgia Hospital

Nosocomial pseudoepidemics may be detected when clustering of pseudoinfections occur or when artificial clusters of real infection are observed. Nontuberculous mycobacteria were reportedly isolated from specimens obtained from seven patients at one hospital from October 1980 to January 1981. Because the patients' clinical illnesses were not uniformly consistent with mycobacterial disease, we hypothesized that pseudoinfections had occurred and searched for a common source of contamination. The investigation suggested that specimen contamination was associated with one microbiology laboratory technician: 6 of 22 (27%) specimens processed by that person were positive compared with 1 of 103 (1%) specimens processed by the other five technicians. However, a specific mechanism of contamination was not identified. Nosocomial pseudoepidemics associated with false infections should be suspected and investigated when clinical features and laboratory findings do not agree.

Aqueous benzene-diols react with an organic triplet excited state and hydroxyl radical to form secondary organic aerosol

Benzene-diols are oxidized rapidly by hydroxyl radical and the triplet excited state of an aromatic carbonyl to efficiently form SOA in the aqueous phase.

Oscillation and reaction board techniques for estimating inertial properties of a below-knee prosthesis

The purpose of this study was two-fold: (1) demonstrate a technique that can be used to directly estimate the inertial properties of a below-knee prosthesis, and (2) contrast the effects of the proposed technique and that of using intact limb inertial properties on joint kinetic estimates during walking in unilateral, transtibial amputees. An oscillation and reaction board system was validated and shown to be reliable when measuring inertial properties of known geometrical solids. When direct measurements of inertial properties of the prosthesis were used in inverse dynamics modeling of the lower extremity compared with inertial estimates based on an intact shank and foot, joint kinetics at the hip and knee were significantly lower during the swing phase of walking. Differences in joint kinetics during stance, however, were smaller than those observed during swing. Therefore, researchers focusing on the swing phase of walking should consider the impact of prosthesis inertia property estimates on study outcomes. For stance, either one of the two inertial models investigated in our study would likely lead to similar outcomes with an inverse dynamics assessment.

Secondary organic aerosol production from aqueous reactions of atmospheric phenols with an organic triplet excited state

Condensed-phase chemistry plays a significant role in the formation and evolution of atmospheric organic aerosols. Past studies of the aqueous photoformation of secondary organic aerosol (SOA) have largely focused on hydroxyl radical oxidation, but here we show that triplet excited states of organic compounds ((3)C*) can also be important aqueous oxidants. We studied the aqueous photoreactions of three phenols (phenol, guaiacol, and syringol) with the aromatic carbonyl 3,4-dimethoxybenzaldehyde (DMB); all of these species are emitted by biomass burning. Under simulated sunlight, DMB forms a triplet excited state that rapidly oxidizes phenols to form low-volatility SOA. Rate constants for these reactions are fast and increase with decreasing pH and increasing methoxy substitution of the phenols. Mass yields of aqueous SOA are near 100% for all three phenols. For typical ambient conditions in areas with biomass combustion, the aqueous oxidation of phenols by (3)C* is faster than by hydroxyl radical, although rates depend strongly on pH, oxidant concentrations, and the identity of the phenol. Our results suggest that (3)C* can be the dominant aqueous oxidant of phenols in areas impacted by biomass combustion and that this is a significant pathway for forming SOA.

Pediatric inflammatory diseases. Part I: multiple sclerosis

Multiple sclerosis (MS) is an inflammatory CNS disease characterized by multifocal areas of demyelination; usually it arises in young adults, but can also occur in children (under the age of 10) and adolescents (under the age of 18). As in adult, pediatric MS (PMS) diagnosis is based on the demonstration of multiple demyelination episodes separated in time and spaces. Diagnostic criteria realized for childhood are similar to those employed for adults. Although clinical and imaging features of PMS can be similar to those of adults, the disease is often characterized by a more aggressive course and atypical imaging findings, with giant and pseudotumoral plaques. Differential diagnosis between PMS and ADEM could be difficult: clinical findings and MRI are necessary; sometimes MRI follow-up is required for definitive diagnosis.

Pediatric Inflammatory Diseases. Part II: Acute Post-Infectious Immune Disorders

Acute post-infectious immune disorders include Acute Disseminated Encephalomyelitis (ADEM) and its variants such as Acute Hemorrhagic Encephalomyelitis (AHEM), acute necrotizing hemorrhagic leukoencephalitis (ANHLE) of Weston Hurst, multiphasic and recurrent ADEM. Acute Necrotizing Encephalopathy of Childhood (ANE or ANEC) represents a dramatic event, consequent to viral infections, especially Influenza-A, and is now considered different from ADEM. ADEM and variants are classically described as uniphasic syndrome occurring in association with an immunization or vaccination (postvaccine encephalomyelitis) or systemic viral infection (parainfectious encephalomyelitis). However, multiphasic forms are not rare. Pathologically, there is perivascular inflammation, edema, and demyelination within the CNS. Clinical features are focal or multifocal neurologic disorder following exposure to virus or receipt of vaccine. The onset of the CNS disorder is usually rapid and include encephalopathy ranging from lethargy to coma, seizures, and focal and multifocal signs reflecting cerebral and spinal cord involvement. The mortality rate is estimated at 10 to 30 percent, with complete recovery rates of 50 percent cited. Poor prognosis is correlated with severity and abruptness of onset of the clinical syndrome. Multifocal CNS lesions are generally evident on MRI that can be similar from those observed in MS.