Uniform Boundedness of S-Units in Arithmetic Dynamics

Let K be a number field and let S be a finite set of places of K which contains all the Archimedean places. For any f(z) in K(z) of degree d at least 2 which is not a d-th power in \bar{K}(z), Siegel's theorem implies that the image set f(K) contains only finitely many S-units. We conjecture that the number of such S-units is bounded by a function of |S| and d (independently of K and f). We prove this conjecture for several classes of rational functions, and show that the full conjecture follows from the Bombieri--Lang conjecture

Workers’ Affective Commitment in The Gig Economy: The Role of IS Quality, Organizational Support, and Fairness

Background: The rapidly growing gig economy brings lots of opportunities and challenges, and one of them is workers’ affective commitment. Because of the gig economy’s nature, gig workers depend on the technology-enabled platform to finish their tasks. We investigate how gig workers’ perception of the platform’s quality, or IS quality, will affect how they perceive organizational support and fairness, which further affects their affective commitment. Method: We surveyed 239 Uber drivers in Indonesia to test our model via snow-balling technique. We used PLS with a second-order formative construct model to validate our hypotheses. Results: The results showed that the two dimensions of IS quality, information quality and system quality, were positively associated with organizational support. Only information quality was positively associated with fairness. Both organizational support and fairness were positively associated with affective commitment. Conclusion: For uber drivers, information quality and system quality of the Uber App serve as drivers of perceived organization support. Information quality also contributes to perceived fairness. Drivers who perceive high organization support and fairness are more likely to be affectively committed to the organization

Observational longitudinal study of symptom burden and time for recovery from community-acquired pneumonia reported by older adults surveyed nationwide using the CAP Burden of Illness Questionnaire.

BACKGROUND: Millions of older adults who develop community-acquired pneumonia (CAP) each year survive, but there is a large knowledge gap on the burden of CAP and the recovery process in survivors from the patient perspective. METHODS: The newly developed CAP Burden of Illness Questionnaire was administered through a Web survey to a nationwide sample of US adults aged ≥50 years who were recently diagnosed with CAP. Survey respondents with unresolved symptoms or other CAP-related health problems completed a second survey 30 days later; a third survey was completed another 30 days later by respondents with unresolved symptoms or problems. Nationally representative results describing the average time to recovery of symptoms and other CAP-related problems were achieved using post-stratification weights. RESULTS: Five hundred participants completed the initial survey. The time to resolution for the CAP symptoms of weakness, shortness of breath, and tiredness exceeded 3 weeks on average. There was an average of 13 days of absenteeism, and 3 weeks (mean =21 days) before achieving full work/activity productivity after CAP. For participants with health conditions that worsened from pneumonia, chronic emphysema and chronic obstructive pulmonary disease took the longest to return to baseline (mean =60 and 52.4 days, respectively). CONCLUSION: The results from this study demonstrate that older adults surviving a CAP episode experience a significant multi-symptom illness with long recovery periods to achieve pre-CAP health and productivity. These findings highlight the need for further research on effective clinician-patient communication, the need for patient-centered outcomes in clinical trials for CAP therapeutics, adequate home care during the recovery process, and the pursuit of CAP prevention strategies

Assessing a novel contact heater as a new method of recovering explosives traces from porous surfaces

It can be very challenging to recover explosives traces from porous surfaces, such as clothing and car seats, compared to non-porous surfaces. The contact heater has been developed as a novel instrument designed to recover explosives traces from porous surfaces. Samples are taken by heating and drawing air across a surface, with the air flowing through a sampling cartridge containing adsorbent polymer beads, which act to trap any recovered explosive material. Any collected explosive can then be eluted from this cartridge using a solvent, prior to analysis. This paper outlines work performed to evaluate the usefulness of the contact heater with regards to the recovery of explosives traces from porous materials. Ethylene glycol dinitrate (EGDN) and triacetone triperoxide (TATP) were chosen as two representative explosives for this study. Quantification was performed using GC–MS for EGDN and LC–MS/MS for TATP. Different sampling temperatures, sampling times and elution solvents were investigated. Recovery was trialled from leather, carpet and denim. Recoveries of up to 71% were obtained following optimisation. It was also possible to recover TATP from fabrics exposed to TATP vapour in a vapour-laden jar up to two hours after exposure. The contact heater therefore appears to be a very useful tool for the recovery of explosives traces from porous materials

Exploring the Impact of Interviewer Perceptions and Interviewer-Respondent Interactions on the Survey of Income and Program Participation: Analysis of CARI recordings

Interviewers play a significant role in telephone and face-to-face interviews, including gaining respondent cooperation and administering survey questions. Increasingly, interviewers’ perceptions of the respondent and interview experience, such as cooperativeness and interest, are also being used to assess measurement error and make adjustments to data (West, 2013; Kirchner et al., 2017). Although interviewer perceptions are typically recorded at the end of the interview, interviewers are likely to begin forming perceptions about the household and respondent based on their first contact attempt (and continue developing them during the interview). We hypothesize that interview context factors, such as interviewer perceptions of the physical interview environment and the respondent’s reluctance, may interact with question characteristics, such as sensitivity and cognitive burden, to influence interviewer-respondent interactions. One survey that may be particularly impacted by context factors is the Survey of Income and Program Participation (SIPP). The SIPP is a multi-wave household survey that asks questions about economic well-being, family dynamics, and housing security, among other sensitive and cognitively burdensome topics. SIPP interviewers receive standardized training but they also implement individual strategies as they react to the questionnaire, respondent, and interview context. For example, interviewers may anticipate that some respondents will react sensitively to interview questions and proactively tailor questions to reduce sensitivity. The criteria that interviewers use to make these judgments may vary, resulting in differences in question-asking and probing behavior that may ultimately affect response distributions and respondent burden in unexpected ways. The purpose of the present study was to develop a framework of the interviewer-respondent interaction from the interviewer’s perspective. A primary goal was to investigate whether an interviewer’s question-asking or probing behavior differs between contexts that are sensitive or burdensome (e.g., sensitive and non-sensitive questions; reluctant and non-reluctant respondents). In addition, we identify the interviewer behaviors that appear to reduce respondent behaviors associated with measurement error. To do this, we combined several data sources from the 2014 SIPP Panel: computer audio-recorded interviewing (CARI) recordings, interviewer perceptions of the physical interview environment (Neighborhood Observation Instrument, NOI) and of respondent behaviors during contact attempts (Contact History Instrument, CHI), SIPP data including responses to survey questions and demographics, and interviewer characteristics. Three researchers independently transcribed and coded audio recordings of the full interaction for a sample of the targeted questions. Behavior codes included: whether the interviewer changed the survey question and what type of change was made (e.g., tailored the question to match the respondent’s situation), how the interviewer reacted to responses (used a suggestive probe); whether the respondent did not give a codeable response (a vague answer that does not unambiguously match a response option); and other codes that describe the interaction (pauses, interruptions). We plan to present descriptive analyses of interviewer and respondent behaviors, as well as modeling results that examine the extent to which (a) selected interview context factors predict interviewer behavior and (b) interviewing strategies predict response and interview outcomes. Implications for data quality, interviewer training, questionnaire design, and survey methods in general will be discussed

The stability of TNT, RDX and PETN in simulated post-explosion soils:Implications of sample preparation for analysis

Explosives residues in soils may be a useful source of evidence following the detonation of an improvised explosive device (IED), such as a vehicle-borne IED. Soil samples collected from the vicinity of an explosion scene will often be stored for some time prior to analysis, yet explosives residues in soil samples are susceptible to rapid degradation or transformation. Although some research has assessed the use of different storage temperatures with a view to reducing explosives' degradation over time, further research examining the degradation of explosives in soil when stored under a variety of storage conditions is crucial to determine the optimal sample collection and storage procedures for soil containing explosives residues. In this work, three different soils were spiked with solutions of TNT, RDX and PETN and stored either at room temperature, refrigerated or frozen. Samples were extracted over 6 weeks, with additional samples gamma-irradiated or nitrogen purged prior to storage. Experimental results indicate that TNT underwent very rapid degradation at room temperature, attributed to microbial action, whereas PETN and RDX proved to be more stable. Gamma irradiation and nitrogen purging proved of some benefit for mitigating TNT degradation, with lower storage temperatures ultimately proving the most effective method of mitigating degradation

Epigenetic aging signatures in mice livers are slowed by dwarfism, calorie restriction and rapamycin treatment

Background: Global but predictable changes impact the DNA methylome as we age, acting as a type of molecular clock. This clock can be hastened by conditions that decrease lifespan, raising the question of whether it can also be slowed, for example, by conditions that increase lifespan. Mice are particularly appealing organisms for studies of mammalian aging; however, epigenetic clocks have thus far been formulated only in humans. Results: We first examined whether mice and humans experience similar patterns of change in the methylome with age. We found moderate conservation of CpG sites for which methylation is altered with age, with both species showing an increase in methylome disorder during aging. Based on this analysis, we formulated an epigenetic-aging model in mice using the liver methylomes of 107 mice from 0.2 to 26.0 months old. To examine whether epigenetic aging signatures are slowed by longevity-promoting interventions, we analyzed 28 additional methylomes from mice subjected to lifespan-extending conditions, including Prop1df/df dwarfism, calorie restriction or dietary rapamycin. We found that mice treated with these lifespan-extending interventions were significantly younger in epigenetic age than their untreated, wild-type age-matched controls. Conclusions: This study shows that lifespan-extending conditions can slow molecular changes associated with an epigenetic clock in mice livers

Incidence, attributable mortality, and healthcare and out-of-pocket costs of Clostridioides difficile infection in US Medicare Advantage Enrollees

BACKGROUND: US attributable Clostridioides difficile infection (CDI) mortality and cost data are primarily from Medicare fee-for-service populations, and little is known about Medicare Advantage Enrollees (MAEs). This study evaluated CDI incidence among MAEs from 2012 to 2019 and determined attributable mortality and costs by comparing MAEs with and without CDI occurring in 2018. METHODS: This retrospective cohort study assessed CDI incidence and associated mortality and costs for eligible MAEs ≥65 years of age using the de-identified Optum Clinformatics Data Mart database (Optum; Eden Prairie, Minnesota, USA). Outcomes included mortality, healthcare utilization, and costs, which were assessed via a propensity score-matched cohort using 2018 as the index year. Outcome analyses were stratified by infection acquisition and hospitalization status. RESULTS: From 2012 to 2019, overall annual CDI incidence declined from 609 to 442 per 100 000 person-years. Although the incidence of healthcare-associated CDI declined overall (2012, 53.2%; 2019, 47.2%), community-associated CDI increased (2012, 46.8%; 2019, 52.8%). The 1-year attributable mortality was 7.9% (CDI cases, 26.3%; non-CDI controls, 18.4%). At the 2-month follow-up, CDI-associated excess mean total healthcare and out-of-pocket costs were $13 476 and$396, respectively. Total excess mean healthcare costs were greater among hospitalized (healthcare-associated, $28 762; community-associated,$28 330) than nonhospitalized CDI patients ($5704 and$2320, respectively), whereas total excess mean out-of-pocket cost was highest among community-associated hospitalized CDI patients ($970). CONCLUSIONS: CDI represents an important public health burden in the MAE population. Preventive strategies and treatments are needed to improve outcomes and reduce costs for healthcare systems and this growing population of older US adults