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The combustion of solid fuels is a complex feedback loop, coupling the decomposition of the solid fuel into volatile gases with the gas-phase combustion which is responsible for the heat flux that drives decomposition. This study aims to explore the combustion of a solid fuel, hydroxyl-terminated polybutadiene (HTPB), with different mixtures of oxygen and nitrogen in an opposed-flow burner (OFB) configuration to better understand these coupled processes. An experimental OFB setup is described, which utilizes a nichrome wire and linear variable differential transformer (LVDT) to capture regression rate and shadowgraph imaging to measure flame thickness. Experimental measurements are compared with results from a complimentary one-dimensional opposed-flow combustion model with a pyrolyzing solid fuel boundary condition that conserves mass, species, and energy at the solid-gas interface. The oxidizer mass flux, ratio of oxygen to nitrogen, and separation distance of the fuel and oxidizer are varied to understand their influence on the combustion process and subsequently their effect on the regression rate. In numerical results, fuel regression rate increases when oxygen mole fraction or mass flux increase, or when separation distance decreases. Experimental regression rates and flame thicknesses are compared to simulated results. Though the actual values do not agree exactly, numerical and experimental results are reasonably close and present similar trends. These results demonstrate the utility of simple optical diagnostics in measuring OFB flames and provide a starting point for future opposed-flow combustion model improvements. [ABSTRACT FROM AUTHOR]

Objective: To predict the association between demographic, psychological, and medication-specific characteristics and the level of concern about stopping medications among older adults.Design: Cross-sectional study in which participants read 6 vignettes in which a primary care provider broached the idea of stopping a medication. Medications differed in risk, regulatory status, and indication for discontinuation.Setting and Participants: National Web-based survey distributed to adults aged 65 years or older by Dynata in January 2019.Outcome Measures: Participants reported their concern about stopping each medication (7-point scale, not at all to extremely), their preferences for more versus less care (Medical Maximizer-Minimizer Scale, MMS), medication attitudes (Beliefs about Medicines Questionnaire, BMQ), demographic characteristics, and health literacy. We used a generalized estimating equations population-averaged model to examine characteristics associated with concern about stopping medications among all the vignettes and linear regressions to explore levels of concern for individual vignettes. Regressions included the MMS, BMQ, health literacy, and demographics.Results: A total of 942 individuals started the survey, and 823 were included in our analysis. Approximately one-half of participants (range: glyburide, 49.5% to aspirin, 56.0%) reported substantial concern (≥ 4 on a 1-7 scale) about stopping each medication. Characteristics that significantly increased concern about stopping medications included female gender, identifying as black or African American, higher MMS score, and higher BMQ specific score. Higher MMS score predicted increased concern about stopping medications for each of the 6 medications.Conclusion: Characteristics of older adults (e.g., medical maximizing-minimizing preferences), as opposed to medication-specific characteristics, predict concern about stopping medications. [ABSTRACT FROM AUTHOR]

Background: There is limited evidence describing long-term implant survivorship and modes of failure in simultaneous concurrent bilateral total knee arthroplasty (TKA).Methods: We performed a retrospective review of 266 consecutive patients (532 knees) who underwent simultaneous concurrent bilateral TKA. We reviewed medical records for preoperative characteristics, perioperative complications, and revision surgeries. The primary outcome was TKA survivorship. Secondary outcomes included indication and type of revision surgery. We used the Kaplan-Meier method to estimate survivorship and characterize risk of revision up to 20 years post-TKA.Results: Our cohort had median follow-up of 9.8 years (interquartile range, 3.9-15.9). Forty-four patients (17%) underwent revision. Revision was more common among younger and male patients. The cumulative incidence of first-time revision per knee (n = 532) was 1.27 per 100 component-years. Implant survival was 99% (confidence interval, 97%-99%) at 5 years, 92% (89%-95%) at 10 years, 83% (77%-87%) at 15 years, and 62% (50%-73%) at 20 years. Five and 10-year survivorship compared favorably to estimates of TKA survivorship in the literature. The cumulative incidence of revision surgery per patient was 1.91 per 100 component-years. Implant survival at 5-, 10-, 15-, and 20-year time points was 96% (CI, 92%-98%), 84% (77%-89%), 71% (62%-79%), and 59% (46%-70%), respectively. Aseptic loosening (40%), polyethylene wear (34%), and infection (11%) were the most common indications for revision.Conclusion: Simultaneous concurrent bilateral TKA is associated with a higher risk of reoperation for the patient when both knees are evaluated but similar implant survivorship to the literature when each knee was evaluated in isolation. [ABSTRACT FROM AUTHOR]

Introduction: Geriatric fracture patients are at risk for poorly controlled pain and side effects of opioid medications. The arthroplasty literature has demonstrated that infiltration of long-acting local anesthetic or anesthetic cocktails improves pain control and reduces post-operative opioid use resulting in better postoperative mobility without the deleterious effects of narcotics. Despite having a higher risk for adverse events, there is limited data among geriatric trauma patients. The aim this study was to evaluate whether local anesthetic infiltration (LAI) into the soft tissues surrounding the surgical field reduces narcotic use or pain scores in patients undergoing surgical management of proximal and diaphyseal femur fractures.Materials and Methods: A retrospective review was performed of patients age >65 undergoing operative intervention for proximal and diaphyseal femur fracture. The electronic record was utilized to determine if local anesthetic was injected into the surgical wound, the amount of narcotics administered over 48 h in four-hour intervals, and to obtain visual analog scale (VAS) pain scores associated with patients post-operative course in four-hour intervals. The amount of narcotics was converted to morphine milligram equivalents (MME).Results: Among 477 patients with femur fracture, 358 did not receive LAI and 119 patients received LAI. Baseline demographics, fracture types, and surgical procedure were equivalent between the groups. In the first 28 h following surgery, compared with those who did not receive LAI, those who did required significantly less opioid (57.8 MME versus 94.3 MME, p = 0.034) and despite decreased narcotics, had equal pain scores (mean difference 0.37, p = 0.22). There was no difference in rates of post-operative complications.Conclusion: LAI is associated with a reduction in opioid consumption in geriatric fracture patients with equivalent pain scores. Optimizing pain control is a critical issue in caring for geriatric fracture patients since both under-treated pain and opioid medications are implicated in postoperative delirium, complications, and ability to mobilize early. More research is needed to identify effective ways to optimize pain management in this at-risk patient population. [ABSTRACT FROM AUTHOR]

A targeted, improv-based exercise was developed as a novel skills training approach to bad news disclosure for medical professionals and trainees, focusing on specific characteristics that influence these conversations including nature of the bad news, implications, personal responsibility, and status differences. [ABSTRACT FROM AUTHOR]

Sonochemically-generated Ti−Al−B reactive mixed-metal nanopowders were tested by seeding them into a premixed, fuel-lean (Φ = 0.63), methane/air flame to investigate their combustion characteristics. Tests were conducted on powders with and without cryogenic milling. The attenuation of a diode laser beam was measured to calculate the time-resolved concentration of the powder in the flame. Radiant heat flux was measured with three gauges at different heights (1 cm, 6 cm, and 12 cm) along the axis of the flame. Flame spectra were collected to monitor chemiluminescence of intermediate species, and a multi-wavelength pyrometry method was applied to the spectra to calculate the temperature of the hot particulates in the flame. Commercially available metal powders were tested as a benchmark. These included micron-scale aluminum, nano-scale aluminum, micron-scale boron, and inert nano-scale alumina powders. The spectra from flames seeded with the sonochemically-generated Ti−Al−B powder show strong chemiluminescence from the BO 2 , an indicator of boron oxidation. Peak temperatures measured with flame pyrometry were approximately 2100 K, which is below the vaporization point of B 2 O 3 . The radiant heat flux from the seeded flame increased with concentration faster for the Ti−Al−B material than for any of the commercial powders, suggesting a greater gravimetric power density. Based on these results, the Ti−Al−B powders show promising combustion and heat-release characteristics, and therefore warrant further examination as a high-performance solid fuel. [ABSTRACT FROM AUTHOR]

Selenium assimilation in plants is facilitated by several enzymes that participate in the transport and assimilation of sulfate. Manipulation of genes that function in sulfur metabolism dramatically affects selenium toxicity and accumulation. However, it has been proposed that selenite is not reduced by sulfite reductase. Instead, selenite can be non-enzymatically reduced by glutathione, generating selenodiglutathione and superoxide. The damaging effects of superoxide on iron-sulfur clusters in cytosolic and mitochondrial proteins are well known. However, it is unknown if superoxide damages chloroplastic iron-sulfur proteins. The goals of this study were twofold: to determine whether decreased activity of sulfite reductase impacts selenium tolerance in Arabidopsis, and to determine if superoxide generated from the glutathione-mediated reduction of selenite damages the iron-sulfur cluster of ferredoxin. Our data demonstrate that knockdown of sulfite reductase in Arabidopsis does not affect selenite tolerance or selenium accumulation. Additionally, we provide in vitro evidence that the non-enzymatic reduction of selenite damages the iron-sulfur cluster of ferredoxin, a plastidial protein that is an essential component of the photosynthetic light reactions. Damage to ferredoxin’s iron-sulfur cluster was associated with formation of apo-ferredoxin and impaired activity. We conclude that if superoxide damages iron-sulfur clusters of ferredoxin in planta , then it might contribute to photosynthetic impairment often associated with abiotic stress, including toxic levels of selenium. [ABSTRACT FROM AUTHOR]

Background: Despite parents' stated desire to treat pain in their children, recent studies have critiqued their underuse of prescribed analgesics to treat pain in their children after painful procedures. Parents' analgesic preferences, including their perceived importance of providing pain relief or avoiding adverse drug effects may have important implications for their analgesic decisions, yet no studies have evaluated the influence of preferences on decisions to withhold prescribed opioids for children. Objectives: We prospectively explored how parents' preferences influenced decisions to withhold prescribed opioids when faced with hypothetical dilemmas and after hospital discharge. Design: Prospective Observational Study Design: Phase 1 included hypothetical analgesic decisions and Phase 2, real analgesic decisions after hospital discharge. Setting: Large tertiary care pediatric hospital in the Midwest of the United States. Participants: Five-hundred seven parents whose children underwent a painful surgical procedure requiring an opioid prescription were included. Methods: At baseline, parents completed surveys assessing theirpain relief preference (i.e., their rated importance of pain relief relative to adverse drug event avoidance), preferred treatment thresholds (i.e., pain level at which they would give an opioid), adverse drug event understanding, and hypothetical trade-off decisions (i.e., scenarios presenting variable pain and adverse drug event symptoms in a child). After discharge, parents recorded all analgesics they gave their child as well as pain scores at the time of administration. Results: Higher preference to provide pain relief (over avoid analgesic risk) lessened the likelihood that parents would withhold the prescribed opioid when adverse drug event symptoms were present together with high pain scores in the hypothetical scenarios. Additionally, higher preferred treatment thresholds increased the likelihood of parents withholding opioids during their hypothetical decision-making as well as at home. The strong influence of these preferences weakened the effect of opioid ADE understanding on decisions to withhold opioids when ADEs (i.e., nausea/vomiting or oversedation) were present together with high pain. Conclusions: Findings from this study suggest that preferences strongly influence and may interfere with parents' effective and safe analgesic decision-making when conflicting symptoms (i.e., high pain and an ADE) are present. To improve effective analgesic use, there is a need to shape parents' preferences and improve their understanding of safe actions that will treat pain when ADE symptoms are present. [ABSTRACT FROM AUTHOR]

During the selenium assimilation pathway, inorganic selenate and selenite are reduced to form se leno c ysteine (Sec). Tolerance to selenium in plants has long been attributable to minimizing the replacement of cysteine with selenocysteine, which can result in nonspecific selenoproteins that are potentially misfolded. Despite this widely accepted assumption, there is no evidence in higher plants demonstrating that selenocysteine induces toxicity by resulting in malformed proteins. In this study, we use Brassica napus to analyze the ubiquitin-proteasome pathway, which is capable of removing misfolded proteins. Sec rapidly increased proteasome activity and levels of ubiquitinated proteins, strongly indicating that selenocysteine induces protein misfolding. Proteasome inhibition increased the amount of selenium in protein in Sec-treated plants. Collectively, these data provide a mechanism that accounts for Sec toxicity. Additionally, Sec did not cause oxidative stress as judged by examining levels of superoxide using fluorescent microscopy. Therefore, the cellular response to Sec is different compared to selenite, which was recently shown to increase antioxidant metabolism in response to elevated mitochondrial superoxide that ultimately impaired proteasome activity. Therefore, plants must contend with two divergent modes of cytotoxicity during selenium assimilation. Selenite can result in oxidative stress, but increased flux of selenite reduction can yield Sec that in turn can cause protein misfolding. [ABSTRACT FROM AUTHOR]

Objective To characterize the medical history, disease progression, and treatment of current-era patients with the rare diseases Fontan-associated protein-losing enteropathy (PLE) and plastic bronchitis. Study design A novel survey that queried demographics, medical details, and treatment information was piloted and placed online via a Facebook portal, allowing social media to power the study. Participation regardless of PLE or plastic bronchitis diagnosis was allowed. Case control analyses compared patients with PLE and plastic bronchitis with uncomplicated control patients receiving the Fontan procedure. Results The survey was completed by 671 subjects, including 76 with PLE, 46 with plastic bronchitis, and 7 with both. Median PLE diagnosis was 2.5 years post-Fontan. Hospitalization for PLE occurred in 71% with 41% hospitalized =3 times. Therapy varied significantly. Patients with PLE more commonly had hypoplastic left ventricle (62% vs 44% control; OR 2.81, 95% CI 1.43-5.53), chylothorax (66% vs 41%; OR 2.96, CI 1.65-5.31), and cardiothoracic surgery in addition to staged palliation (17% vs 5%; OR 4.27, CI 1.63-11.20). Median plastic bronchitis diagnosis was 2 years post-Fontan. Hospitalization for plastic bronchitis occurred in 91% with 61% hospitalized =3 times. Therapy was very diverse. Patients with plastic bronchitis more commonly had chylothorax at any surgery (72% vs 51%; OR 2.47, CI 1.20-5.08) and seasonal allergies (52% vs 36%; OR 1.98, CI 1.01-3.89). Conclusions Patient-specific factors are associated with diagnoses of PLE or plastic bronchitis. Treatment strategies are diverse without clear patterns. These results provide a foundation upon which to design future therapeutic studies and identify a clear need for forming consensus approaches to treatment. [ABSTRACT FROM AUTHOR]

As part of a survey of about vaccination beliefs, a nationally representative sample of parents of young children answered a series of tradeoff questions that asked them to choose between two vaccination approaches that differed in terms of risks of vaccine complications, number of injections, and/or vaccine effectiveness. Most parents were willing to have their children endure more injections, and many were willing to forgo disease protection, in order to reduce the rare chance of febrile seizures. Yet, most parents were unwilling to trade disease protection to reduce the risk of fever alone, even though this is correlated with the risk of febrile seizures. Vaccine risk communications need to address the heightened emotional weight that parents give to febrile seizure risk, even when the rarity of such events is explicit. [ABSTRACT FROM AUTHOR]

BACKGROUND: Guidelines are in place directing the clearance of the cervical spine in patients who are awake, alert, and oriented, but a gold standard has not been recognized for patients who are ob-tunded. Our study is designed to determine if magnetic resonance imaging (MRI) detects clinically sig-nificant injuries not seen on computed tomographic (CT) scans. METHODS: The trauma registry was used to identify and retrospectively review medical records of blunt trauma patients from January 1, 2005, to March 30, 2012. Only obtunded patients with a CT scan and MRI of the cervical spine were included. RESULTS: The study cohort consisted of 277 patients. In 13 (5%) patients, MRI detected clinically significant cervical spine injuries that were missed by CT scans, and in 7 (3%) these injuries required intervention. The number needed to screen with MRI to prevent 1 missed injury was 21. CONCLUSIONS: The findings suggest that the routine use of MRI in clearing the cervical spine in the obtunded blunt trauma patient. [ABSTRACT FROM AUTHOR]

Objective To describe the pharmacoepidemiology of rituximab use in children and to estimate the frequency of infectious events within a 1-year period after rituximab exposure. Study design This is a retrospective cohort study of patients who received rituximab at 1 of 42 children's hospitals contributing data to the Pediatric Health Information System between January 1999 and June 2011. International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) discharge diagnosis codes were analyzed to categorize underlying diseases (hematologic malignancies, primary immunodeficiencies, autoimmune diseases, and transplant recipients) and to estimate inpatient infectious complication rates within each category. Results A total of 2875 patients with 4639 rituximab admissions were identified. The median age at index admission was 11 years (IQR, 5-15 years). The rate of rituximab admissions increased from 3 to 185 per 100 000 admissions per year over the study interval. During the 1-year follow-up period, 463 patients (16%) died. Infectious events were assessed in 2246 of the rituximab-exposed patients; 6.1% were diagnosed with sepsis and 2.0% with septic shock. The frequency of sepsis ranged from 2.4% in patients with autoimmune diseases to 12.2% in those with primary immunodeficiencies. Three patients were assigned an ICD-9-CM discharge diagnosis code for Pneumocystis joroveci pneumonia, 1 patient was assigned an ICD-9-CM discharge diagnosis code for hepatitis B, and 1 patient was assigned an ICD-9-CM discharge diagnosis code for progressive multifocal leukoencephalopathy. Conclusion The use of rituximab has increased significantly in children with a variety of underlying diseases. Based on ICD-9-CM code data, the rates of sepsis and other life-threatening infections after rituximab exposure vary depending on the underlying condition. Based on surveillance of infection using ICD-9-CM diagnosis codes, the rates of opportunistic infections appear to be low [ABSTRACT FROM AUTHOR]

Background: Health care worker (HCW) hand hygiene (HH) is the core strategy to prevent health care- associated infections (HAI). Suboptimal HCW HH rates continue despite hospital efforts to increase compliance. Objectives: To determine whether parents of hospitalized children perceive they have a role in preventing HAI and whether they are willing to remind HCW to perform HH, with and without an invitation. Methods: We conducted structured interviews of parents of children admitted to a pediatric hospital. Questions assessed knowledge, attitudes, and behaviors about HAI and HH. The primary outcome was willingness to remind a HCW to do HH (5-point Likert scale). Results: We interviewed 115 parents, of whom 84% were aware of HAI. Most parents (78%) perceived HH as the most important practice to prevent HAI. However, only 67% would definitely remind a HCW to perform HH. Importantly, 92% said that an invitation from a HCW would make them more likely to remind a HCW to do HH in the future. Conclusion: Our results suggest that parents of hospitalized children are willing to help prevent HAI; however one-third are still reluctant to remind HCW to perform HH. An invitation by HCW to parents to remind HCW to perform HH might effectively engage parents as partners in HAI prevention. [ABSTRACT FROM AUTHOR]

Abstract: Chemical properties of contaminants lead them to behave in particular ways in the environment and hence have specific pathways to human exposure. If residents of affected communities lack awareness of these properties, however, they could make incorrect assumptions about where and how exposure occurs. We conducted a mailed survey of 904 residents of Midland and Saginaw counties in Michigan, USA to assess to what degree residents of a community with known dioxin contamination appear to understand the hydrophobic nature of dioxins and the implications of that fact on different potential exposure pathways. Participants assessed whether various statements about dioxins were true, including multiple statements assessing beliefs about dioxins in different types of water. Participants also stated whether they believed different exposure pathways were currently significant sources of dioxin exposure in this community. A majority of residents believed that dioxins can be found in river water that has been filtered to completely remove all particulates, well water, and even city tap water, beliefs which are incongruous with the hydrophobic nature of dioxins. Mistrust of government and personal concern about dioxins predicted greater beliefs about dioxins in water. In turn, holding more beliefs about dioxins in water predicted beliefs that drinking and touching water are currently significant exposure pathways for dioxins. Ensuring that community residents'' mental models accurately reflect the chemical properties of different contaminants can be important to helping them to adjust their risk perceptions and potentially their risk mitigation behaviors accordingly. [Copyright &y& Elsevier]

Abstract: The emergence of Web 2.0 has led to more and more Web-based resources demonstrating three defining characteristics: user participation, openness and network effects. This paper discusses these characteristics in the context of the online vaccination debate, explores how they structurally alter the way people might interact with vaccination information online, and describes ways in which such characteristics support particular tendencies in human decision making processes. Specifically, user participation supports the influence of narratives and personal accounts, openness shapes expectations for greater levels of detail and movement toward models of informed decision making, and network effects demonstrate the social nature of decision making, the influence of like-minded others and thus, the pitfalls of polarization in the online vaccination debate. Web 2.0 means that concerns about vaccination information online must expand beyond simply the possibility that people might access information of varying quality to incorporate a more comprehensive understanding of how people use current Web functionality, how such usage influences expectations about information sources and decision making processes, and the implications for communication strategies about vaccination. [Copyright &y& Elsevier]

Abstract: Objective: To identify patient- and decision-type predictors of two key aspects of informed decision making: discussing the cons (not just the pros) of medical interventions and asking patients what they want to do. Methods: Using data from 2473 members of the DECISIONS survey, a nationally representative sample of U.S. adults age 40+, we used logistic regression analysis to identify which patient characteristics predicted patient reports of healthcare providers discussing cons or eliciting preferences about one of 9 common medical decisions. Results: Multiple demographic characteristics predicted both discussions of cons and elicitations of preferences, although the specific characteristics varied between decision contexts. In particular, African-American respondents reported being more likely to receive a discussion of the cons of cancer screening (OR=1.69, p <0.05) yet less likely to have been asked their opinion about either getting a cancer screening test (OR=0.56, p <0.05) or initiating medications (OR=0.53, p <0.05). Significant cross-decision variations remained even after controlling for patient characteristics. Conclusions: Important disparities in patient communication and involvement appear to exist both between different types of medical decisions and between different types of patients. Practice implications: Providers must make sure to consistently discuss the cons of treatment and to solicit input from all patients, especially African-Americans. [Copyright &y& Elsevier]

Objective: Using a cancer-treatment scenario, we tested whether descriptive norm information (e.g., the proportion of other people choosing a particular treatment) would influence people's hypothetical treatment choices.Methods: Women from an Internet sample (Study 1 N=2238; Study 2 N=2154) were asked to imagine deciding whether to take adjuvant chemotherapy following breast cancer surgery. Across participants, we varied the stated proportion of women who chose chemotherapy. This descriptive norm information was presented numerically in Study 1 and non-numerically in Study 2.Results: The descriptive norm information influenced women's decisions, with higher interest in chemotherapy when social norm information suggested that such chemotherapy was popular. Exact statistics about other people's decisions had a greater effect than when norms were described using less precise verbal terms (e.g., "most women").Conclusion: Providing patients with information about what other people have done can significantly influence treatment choices, but the power of such descriptive norms depends on their precision.Practice Implications: Communication of descriptive norms is only helpful if prevailing decisions in the population represent good clinical practice. Strategic presentation of such statistics, when available, may encourage patient outliers to modify their medical decisions in ways that result in improved outcomes. [ABSTRACT FROM AUTHOR]

Abstract: While strategies employing early or late direct-injection of fuel can improve emissions, they also can lead to impingement of liquid-phase fuel on the piston and/or cylinder wall due to low in-cylinder temperatures and densities during the injection event. Previous work has shown that liquid-phase fuel films formed in this way can lead to pronounced degradations in efficiency and emissions. To avoid these problems, a quantitative understanding of fuel-property effects on the liquid penetration length is needed, and this understanding must include conditions where in-cylinder thermodynamic conditions and the injection rate vary with time. This work reports liquid penetration lengths measured in an optical engine under such time-varying conditions. Diagnostics included laser light scattering for measurement of the liquid length and conventional pressure-data acquisition for heat-release analysis. Unsteady liquid penetration was characterized for different injection timings, injection pressures, intake-manifold pressures, and fuel volatilities to gain an understanding of the relative importance of these factors. Fuel volatility was studied by using two fuels, 2,2,4,4,6,8,8-heptamethylnonane (HMN) and 2,2,4-trimethylpentane (TMP), which have very different volatility characteristics. Measured liquid lengths changed as in-cylinder conditions changed, with increasing temperature and density during the compression stroke causing a decrease in liquid length, and decreasing temperature and density during the expansion stroke causing an increase in liquid length. Intake-manifold pressure and fuel volatility were found to be primary factors governing liquid length. Heat loss from the charge gas to the engine and local charge cooling due to fuel vaporization were found to have a secondary influence on liquid length. Injection pressure was found to have little effect. [Copyright &y& Elsevier]

Background & Aims: We followed patients with ongoing hepatitis C virus (HCV) exposure following control of an initial HCV infection to determine whether primary control conferred protection against future persistent infections. Methods: Twenty-two active injection drug users (IDU) who had cleared a primary hepatitis C viremia for at least 60 days were monitored monthly. Reinfection was defined as the detection of a new HCV infection. Protection was assessed based on the magnitude and duration of viremia following reinfection and generation of T-cell and neutralizing antibody (nAb) responses. Results: Reinfection occurred in 11 IDU (50%) who previously spontaneously controlled primary HCV infection. Although viral clearance occurs in approximately 25% of patients with primary infections, spontaneous viral clearance was observed in 83% of reinfected patients. The duration and maximum level of viremia during subsequent episodes of reinfection were significantly decreased compared with those of the primary infection in the same subjects. In contrast to chronic infection, reinfection was associated with a significant increase in the breadth of T-cell responses. During acute infection, nAbs against heterologous viral pseudoparticles were detected in 60% of reinfected subjects; cross-reactive nAbs are rarely detected in patients who progress to chronic infection. Conclusions: HCV reinfection is associated with a reduction in the magnitude and duration of viremia (compared with the initial infection), broadened cellular immune responses, and generation of cross-reactive humoral responses. These findings are consistent with development of adaptive immunity that is not sterilizing but protects against chronic disease. [Copyright &y& Elsevier]

Abstract: We report the first quantitative and calibration-free in situ C2H2 measurement in a flame environment using direct Tunable Diode Laser Absorption Spectroscopy(TDLAS). Utilizing a fiber-coupled Distributed Feedback diode laser near 1535nm we measured spatially resolved, absolute C2H2 concentration profiles in a laminar non-premixed CH4/air flame supported on a modified Wolfhard–Parker slot burner with N2 purge slots to minimize end flames. We developed a wavelength tuning scheme combining laser temperature and current modulation to record with a single diode laser a mesh of 37 overlapping spectral windows and generate an ∼7nm (30cm−1) wide, high-resolution absorption spectrum centered at 1538nm. Experimental C2H2 spectra in a reference cell showed excellent agreement with simulations using HITRAN2004 data. The enhanced wavelength coverage was needed to establish correct C2H2 line identification and selection in the very congested high temperature flame spectra and led to the P17e line as the only candidate for in situ detection of C2H2 in the flame. We used highly efficient optical disturbance correction algorithms for treating transmission and background emission fluctuations in combination with a multiple Voigt line Levenberg–Marquardt fitting algorithm and Pt/Rh thermocouple measurements to achieve fractional optical resolutions of up to 4×10−5 OD (1σ) in the flame (T up to 2000K). Temperature dependent C2H2 detection limits for the P17e line were 60 to 480ppm. By translating the burner through the laser beam with a DC motor we obtained spatially resolved, absolute C2H2 concentration profiles along the flame sheet with 0.5mm spatial resolution as measured with a knife edge technique. The TDLAS-based, transverse C2H2 concentration profiles without any scaling are in excellent agreement with published mass spectrometric C2H2 data for the same flame supported on a similar burner, thus validating our calibration-free TDLAS measurements. [Copyright &y& Elsevier]

Objective: To evaluate the ability of six graph formats to impart knowledge about treatment risks/benefits to low and high numeracy individuals. Methods: Participants were randomized to receive numerical information about the risks and benefits of a hypothetical medical treatment in one of six graph formats. Each described the benefits of taking one of two drugs, as well as the risks of experiencing side effects. Main outcome variables were verbatim (specific numerical) and gist (general impression) knowledge. Participants were also asked to rate their perceptions of the graphical format and to choose a treatment. Results: 2412 participants completed the survey. Viewing a pictograph was associated with adequate levels of both types of knowledge, especially for lower numeracy individuals. Viewing tables was associated with a higher likelihood of having adequate verbatim knowledge vs. other formats (p <0.001) but lower likelihood of having adequate gist knowledge (p <0.05). All formats were positively received, but pictograph was trusted by both high and low numeracy respondents. Verbatim and gist knowledge were significantly (p <0.01) associated with making a medically superior treatment choice. Conclusion: Pictographs are the best format for communicating probabilistic information to patients in shared decision making environments, particularly among lower numeracy individuals. Practice Implications: Providers can consider using pictographs to communicate risk and benefit information to patients of different numeracy levels. [Copyright &y& Elsevier]

Abstract: Objective: To experimentally test whether using pictographs (image matrices), incremental risk formats, and varied risk denominators would influence perceptions and comprehension of side effect risks in an online decision aid about prophylactic use of tamoxifen to prevent primary breast cancers. Methods: We recruited 631 women with elevated breast cancer risk from two healthcare organizations. Participants saw tailored estimates of the risks of 5 side effects: endometrial cancer, blood clotting, cataracts, hormonal symptoms, and sexual problems. Presentation format was randomly varied in a three factor design: (A) risk information was displayed either in pictographs or numeric text; (B) presentations either reported total risks with and without tamoxifen or highlighted the incremental risk most relevant for decision making; and (C) risk estimates used 100 or 1000 person denominators. Primary outcome measures included risk perceptions and gist knowledge. Results: Incremental risk formats consistently lowered perceived risk of side effects but resulted in low knowledge when displayed by numeric text only. Adding pictographs, however, produced significantly higher comprehension levels. Conclusions: Pictographs make risk statistics easier to interpret, reducing biases associated with incremental risk presentations. Practice implications: Including graphs in risk communications is essential to support an informed treatment decision-making process. [Copyright &y& Elsevier]

Abstract: Objective: To test whether providing comparative risk information changes risk perceptions. Methods: Two hundred and forty-nine female visitors to a hospital cafeteria were randomized to one of two conditions which differed in whether their hypothetical breast cancer risks was lower or higher than the average women''s. Participants read a scenario describing a breast cancer prevention pill and indicated their: (1) likelihood of taking the pill and (2) perception of whether the pill provides breast cancer risk reduction. Results: Women told that their hypothetical risk of breast cancer was above average were more likely to endorse taking the pill (2.79 vs. 2.23, F =4.95, p =0.002) and more likely to believe that the pill provided a significant risk reduction in breast cancer (3.15 vs. 2.73, F =4.32, p =0.005), even though the risks were equivalent. Conclusions: Providing people with comparative risk information changes their risk perceptions. People who have above average risk may feel compelled to take a treatment because they are at above average risk and therefore may not thoroughly consider the trade-offs in the risks and benefits of treatment. Practice implications: Physicians and decision aid developers must reconsider the practice of communicating “average risk” information to patients. [Copyright &y& Elsevier]

Abstract: Objective: Previous research has demonstrated that people perceive treatments as less effective when survival graphs show fewer years of data versus more data. We tested whether using mortality graphs would reduce this temporal inconsistency bias. Methods: A demographically diverse sample of 1461 Internet users read about a hypothetical disease and then were randomized to view either survival or mortality graphs that showed either 5 years of data or 15 years of treatment outcomes data. Participants identified the most effective treatment, provided ratings comparing the effectiveness of two treatments, and answered comprehension questions. Results: Treatment effectiveness ratings varied significantly between respondents seeing the 5 year and 15 year survival graphs even though the relative risk reduction was the same in both cases. This variation was significantly reduced in the mortality graph conditions. Responses on comprehension measures were mixed: viewers of mortality graphs were less able to identify which treatment was more effective but better able to correctly report individual data points. Conclusions: Perceptions of treatment effectiveness appear more temporally consistent with mortality graphs than with survival graphs. Practice implications: All line-based risk graphics (whether framed in survival or mortality terms) should highlight duration information to facilitate improved comprehension of treatment effectiveness. [Copyright &y& Elsevier]

Abstract: Extinction concentrations in a non-premixed propane/air co-flow flame were measured for piezoelectrically generated water mist containing sub-10-μm drops. Based on comparison to flame extinction with nitrogen, it was determined that 66% of the total available water mist enthalpy (27% of available enthalpy of vaporization) is used in flame suppression. Flow field analysis, using particle image velocimetry, and simultaneous flame imaging show that the water drops evaporate well outside the flame front and primarily travel vertically past the flame. Sub-micrometer particle imaging data support the assumption that water vapor resulting from drop evaporation near the flame follows the entraining airflow and interacts with the flame. In concert, the extinction and imaging experiments suggest that, due to the proximity and flow direction of the drops relative to the flame as they evaporate, the flame experiences only a portion of the cooling effect induced by drop evaporation. The majority of the evaporating drops likely exchange heat with the neighboring bulk water mist and contribute to flame suppression primarily by providing water vapor as a heat sink. [Copyright &y& Elsevier]

Abstract: We designed a three-channel tunable diode laser absorption spectrometer to make simultaneous in situ measurements of oxygen, carbon monoxide and water vapor in fire environments to aid in the evaluation of water-based fire suppression systems. The instrument also provides simultaneous information on the liquid water content via optical density measurements by evaluation of the captured direct absorption waveforms. We evaluated the spectrometer in a 1350L test enclosure containing a small propane flame and a piezoelectric generated water mist of sub-10μm drops. Mist drop number densities were on the order of 106 cm−3 resulting in transmission losses of greater than 99.99% for a sample pathlength of 21.6cm. We were able to detect and quantify oxygen from transmission levels of 100% down to 0.01% with uncertainties of 0.1 and 0.4vol%, respectively. The water vapor concentration uncertainty never exceeded 0.06vol% even during times of heavy mist loading. Carbon monoxide levels produced in the test enclosure were below the 250ppm detection limit determined from analysis of the noise levels in our detected signals. The liquid water content uncertainty was less than for values that typically reached . [Copyright &y& Elsevier]

Abstract: Ants are increasingly being recognized as useful tools for land managers to monitor ecosystem conditions. However, despite an abundance of studies on ant responses to both environmental disturbance and land management techniques, an analysis of the practice and value of including ants in monitoring is lacking. Consequently, conservation managers are left with little guidance as to if, when, and how ants can be used to assess conservation activities. Based on our review of approximately 60 published studies, we outline five areas where ants provide valuable information for management-based monitoring: (1) to detect the presence of invasive species, (2) to detect trends among threatened or endangered species, (3) to detect trends among keystone species, (4) to evaluate land management actions, and (5) to assess long-term ecosystem changes. We also discuss practical considerations when designing a monitoring framework for ants, including appropriate methods, taxonomic resolution for sampling, and spatial and temporal scale. We find that when integrated with management goals, monitoring ants can provide information over the short-term on topics such as the status of invasive or keystone species, as well as over longer time frames, for instance the impact of climate change. Overall, we conclude that ants merit monitoring based on their inherent ecological qualities, independent of any “indicator” attributes they might have. [Copyright &y& Elsevier]

Patients with chronic health conditions often rate their quality of life (QoL) significantly higher than non-patients. One explanation for this discrepancy is that non-patients focus on the negative aspects of the onset of a condition, especially the early difficulties people face when they first experience a debilitating condition, without considering that patients can adapt to it over time. To test this hypothesis, we had 359 people perform person tradeoff (PTO) elicitations in an online survey, varying whether the treatment programs under consideration saved the lives of patients (a) with pre-existing paraplegia; or (b) who would experience new onset of paraplegia. Half of each group completed an "adaptation exercise" which encouraged them to consider their own ability to emotionally adapt to negative events in general and specifically to having paraplegia. The adaptation manipulation increased the value participants placed on pre-existing paraplegia (p = 0.03) and on new onset paraplegia (p = 0.05), relative to saving healthy lives. Moreover, the adaptation exercise dramatically reduced the differences between evaluations of pre-existing and new onset paraplegia to values within 2% of each other. Our findings suggest that asking non-patients to do an adaptation exercise before giving QoL ratings may help close the gap in ratings between patients and citizen non-patients. [ABSTRACT FROM AUTHOR]

Abstract: Counseling women about breast cancer risks has been found to decrease screening compliance. We investigated whether women''s reactions to risk information are an artifact of requiring women to estimate the risk of breast cancer prior to receiving risk information. Three hundred and fifty-six women were randomized to either make or not make a risk estimate prior to receiving risk information. Outcome measures were participants’ estimates of the average woman''s breast cancer risk and their emotional response to the risk information. Women overestimated the lifetime risk of breast cancer (M = 46%). Women who made risk estimates felt more relieved about the risk and perceived the risk as being lower than women who did not make estimates (p''s &#60; 0.001). Asking people to estimate risks influenced their subsequent perceptions of the risk of breast cancer. [Copyright &y& Elsevier]

• An abbreviated history of wellhead burning research was described. • A range of potential wellhead blowout conditions were examined with their potential influence on burn efficiency. • The current state of the basic research topics that underlie wellbore flow, wellhead ejection, and two-phase fuel plume combustion are described. • The critical finding of previous investigations is that the worst-case discharge flow rate cannot be assumed to be the worst-case wellhead-burning scenario. While wellhead burning has been a hazard for generations, the development of reliable, safe capping practices suggests that wellhead burning can be used as an oil spill mitigation tool. But, there are technical issues that need consideration during spill management planning before intentional wellhead ignition is applied as an standard spill response tactic. This review provides an abbreviated historical perspective of recent work, the practical implications of current policy, and then topically examines the maturity of the fundamental science underlying wellhead ignition and burning that scientists, engineers, and policy makers should consider. To anchor to this work to reality, a wellhead blowout scenario is examined over a range of flow rates. The regimes of two-phase pipe flows, their dependence on wellbore velocities and gas–liquid ratios, and how those regimes might influence the burn efficiency, with particular focus on annular flows, are also examined. The current state of the basic research topics underlying wellbore flow, wellhead ejection, and two-phase fuel plume combustion that remain to be fully explored to accurately predict discharge and burn behavior are then examined and discussed. Among the critical findings presented is that the worst-case discharge flow rate cannot be assumed the worst-case spill scenario. An examination of burn efficiency analyses reveals that there is no body of experimental measurements upon which they are based and validated. It was also found that these oft-cited analyses assume the oil is fully entrained, which is the most ideal, instead of considering other possible two-phase flow regimes. [ABSTRACT FROM AUTHOR]

Solid fuel combustion requires pyrolysis gases to burn near its surface to provide enough heat feedback to decompose the solid and continue to provide the volatile gases required to sustain combustion. This coupled process defines the difficulty in sustaining solid fuel combustion in a variety of propulsion environments and necessitates a fundamental understanding of the physical processes in order to drive system design. This study explores the combustion of hydroxyl-terminated polybutadiene (HTPB) in a counterflow diffusion flame burner with 50% and 100% oxygen content and compares the regression rate and flame standoff to experimental data. A sensitivity analysis is pursued to identify the model parameters that need improvement and to help guide the next campaign of experiments. Neural networks are developed in a compact way as a means of providing quantitative results on the sensitivity of input parameters. Then a fully connected, deeper neural network is trained on the input parameters – oxidizer mole fraction, solid fuel heat of formation, pre-exponential factor of pyrolysis Arrhenius rate, molecular weight of pyrolysis species, oxidizer mass flux, separation distance, and the oxidizer temperature, – and shown to predict output variables – regression rate and flame standoff – within 90% and 95% accuracy respectively. This network is then used to create millions of data points with an overlapping parameter space for further statistical analysis and improvement of model parameters. In all, the data analysis presented using a neural network approach will help drive the design of experiments and is shown to increase the accuracy of the model in comparison to experimental measurements. [ABSTRACT FROM AUTHOR]

Objective: To determine whether older adults would avoid going to the pharmacy (e.g., by restricting medications or requesting delivery) due to the risk of coronavirus disease (COVID-19). Our secondary objectives were to determine the types of medications that the older adults are more likely to restrict and to determine the factors that influence these decisions.Design: Cross-sectional survey experiment in which participants read 6 scenarios, each stating that they had a 3-day supply of a particular medication remaining.Setting and Participants: National Web-based survey distributed to 1457 U.S. adults aged 65 years and older by Dynata from March 25, 2020, to April 1, 2020.Outcome Measures: Participants reported whether they would go to a pharmacy, have a medication delivered, or restrict the use of each medication. They reported their perceptions and experiences with COVID-19, health risk factors, preferences for more or less care (medical maximizer-minimizer), medication attitudes (beliefs about medicines questionnaire), health literacy, prescription insurance status, and demographics.Results: Most participants (84%) were told to shelter in place, but only 12% reported attempting to obtain extra medications. Participants most often reported that they would go to the pharmacy to obtain each medication (ranging from tramadol 48.9% to insulin 64.9%) except for zolpidem, which they were most likely to restrict (45.4%). Participants who reported comorbidities that increased their risk of COVID-19 were just as likely to go to the pharmacy as those without. In multinomial logistic regression analyses, women and the oldest participants were more likely to seek delivery of medications. Restricting medications was most common for 2 symptom-focused medications (tramadol and zolpidem), and both demographic factors (e.g., gender) and beliefs (e.g., medical maximizing-minimizing preferences) were associated with such decisions.Conclusion: Many older adults intend to continue to go to the pharmacy to obtain their medications during a pandemic, even those who have health conditions that further increase their risk for COVID-19. [ABSTRACT FROM AUTHOR]

• A burner was designed to mimic internal and external wellhead flow at reduced scale. • A method was developed to measure burn efficiency by collecting oil fallout. • Air/water spray tests validated the burn efficiency measurement methodology. • Burn efficiency is significantly affected by gas/oil flow conditions. • Burn efficiency appears to be closely tied to liquid entrainment in the burner tube. In the case of wellhead blowout, intentional ignition and burning of the discharge is one option to prevent oil accumulation on the ground or water until the well is capped. A critical factor for this strategy is the burn efficiency of the wellhead fire, or the fraction of the oil discharge that burns and does not fall to the ground. This quantity is better referred to as "apparent burn efficiency" (ABE) because it considers not only fully evaporated and burned liquid oil but also particulates and combustion residuals that disperse into the atmosphere. Due to the scale and inherent danger, oil fallout measurement is untenable for a full-scale fire. This paper presents a method to measure ABE for a scaled-down burner, designed to simulate the internal flow and external spray of a wellhead. The method involves oil collection at limited discrete locations to construct an average radial fallout profile, which is then integrated over the circular area surrounding the burner to estimate total oil fallout mass. This is compared to the known total liquid oil discharge to determine ABE. Validation tests with non-reacting air/water sprays showed nearly complete water fallout and therefore near-zero ABE. For spray flames with Endicott crude oil and a methane/ethane/propane gas mixture, significant findings included: (1) burn efficiency results were consistent from test to test for a given set of conditions, with only a slight but explainable influence of weather conditions; and (2) burn efficiency results were significantly affected by gas/oil flow conditions. [ABSTRACT FROM AUTHOR]