1,538 research outputs found
Estimating covariance matrices using estimating functions in nonparametric and semiparametric regression
We use ideas from estimating function theory to derive new, simply computed consistent covariance matrix estimates in nonparametric regression and in a class of semiparametric problems. Unlike other estimates in the literature, ours do not require auxiliary or additional nonparametric regressions
Transformations of Additivity in Measurement Error Models
In many problems one wants to model the relationship between a response Y and a covariate X. Sometimes it is difficult, expensive, or even impossible to observe X directly, but one can instead observe a substitute variable W which is easier to obtain. By far the most common model for the relationship between the actual covariate of interest X and the substitute W is W = X + U, where the variable U represents measurement error. This assumption of additive measurement error may be unreasonable for certain data sets. We propose a new model, namely h(W) = h(X) + U, where h(.) is a monotone transformation function selected from some family H of monotone functions. The idea of the new model is that, in the correct scale, measurement error is additive. We propose two possible transformation families H. One is based of selecting a transformation which makes the within sample mean and standard deviation of replicated W’s uncorrelated. The second is based on selecting the transformation so that the errors (U’s) fit a prespecified distribution. Transformation families used are the parametric power transformations and a cubic spline family. Several data examples are presented to illustrate the methods
The Policy Implications of Interactions Among Financial Aid Programs
Various gift-aid, loan, and work-study programs help college students fill the gap between educational costs and their financial resources. Previous research generally has examined the effects of a given program by itself. What is missing are studies that investigate interactions among programs, such as how state or university grants reinforce or offset the targeting policies that are embedded in the Pell program. This article draws on research conducted on colleges in Indiana to describe how federal, state, private, and college-based financial aid programs and practices interact with each other to determine the total amount of gift-aid a student receives. It discusses how these relationships can dilute or enhance a program\u27s implicit targeting policies. The lessons learned from this experience provide important insights for developing a fuller appreciation of how current and future gift-aid programs may affect each other
Railway track component condition monitoring using optical fibre Bragg grating sensors
The use of optical fibre Bragg grating (FBG) strain sensors to monitor the condition of safety critical rail components is investigated. Fishplates, switchblades and stretcher bars on the Stagecoach Supertram tramway in Sheffield in the UK have been instrumented with arrays of FBG sensors. The dynamic strain signatures induced by the passage of a tram over the instrumented components have been analysed to identify features indicative of changes in the condition of the components
Redox-Based Probes for Protein Tyrosine Phosphatases
No AbstractPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83769/1/4423_ftp.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/83769/2/anie_201007871_sm_miscellaneous_information.pd
Striving for safety: communicating and deciding in sociotechnical systems
How do communications and decisions impact the safety of sociotechnical systems? This paper frames this question in the context of a dynamic system of nested sub-systems. Communications are related to the construct of observability (i.e. how components integrate information to assess the state with respect to local and global constraints). Decisions are related to the construct of controllability (i.e. how component sub-systems act to meet local and global safety goals). The safety dynamics of sociotechnical systems are evaluated as a function of the coupling between observability and controllability across multiple closed-loop components. Two very different domains (nuclear power and the limited service food industry) provide examples to illustrate how this framework might be applied. While the dynamical systems framework does not offer simple prescriptions for achieving safety, it does provide guides for exploring specific systems to consider the potential fit between organisational structures and work demands, and for generalising across different systems regarding how safety can be managed
Flexible and Mindful Self-Tracking: Design Implications from Paper Bullet Journals
Digital self-tracking technologies offer many potential
benefits over self-tracking with paper notebooks. However,
they are often too rigid to support people’s practical and
emotional needs in everyday settings. To inform the design
of more flexible self-tracking tools, we examine bullet
journaling: an analogue and customisable approach for
logging and reflecting on everyday life. Analysing a corpus
of paper bullet journal photos and related conversations on
Instagram, we found that individuals extended and adapted
bullet journaling systems to their changing practical and
emotional needs through: (1) creating and combining
personally meaningful visualisations of different types of
trackers, such as habit, mood, and symptom trackers; (2)
engaging in mindful reflective thinking through design
practices and self-reflective strategies; and (3) posting
photos of paper journals online to become part of a selftracking
culture of sharing and learning. We outline two
interrelated design directions for flexible and mindful selftracking:
digitally extending analogue self-tracking and
supporting digital self-tracking as a mindful design practice
Activated lymphocyte recruitment into the tumor microenvironment following preoperative sipuleucel-T for localized prostate cancer.
BackgroundSipuleucel-T is a US Food and Drug Administration-approved immunotherapy for asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC). Its mechanism of action is not fully understood. This prospective trial evaluated the direct immune effects of systemically administered sipuleucel-T on prostatic cancer tissue in the preoperative setting.MethodsPatients with untreated localized prostate cancer were treated on an open-label Phase II study of sipuleucel-T prior to planned radical prostatectomy (RP). Immune infiltrates in RP specimens (posttreatment) and in paired pretreatment biopsies were evaluated by immunohistochemistry (IHC). Correlations between circulating immune response and IHC were assessed using Spearman rank order.ResultsOf the 42 enrolled patients, 37 were evaluable. Adverse events were primarily transient, mild-to-moderate and infusion related. Patients developed T cell proliferation and interferon-Îł responses detectable in the blood following treatment. Furthermore, a greater-than-three-fold increase in infiltrating CD3(+), CD4(+) FOXP3(-), and CD8(+) T cells was observed in the RP tissues compared with the pretreatment biopsy (binomial proportions: all P < .001). This level of T cell infiltration was observed at the tumor interface, and was not seen in a control group consisting of 12 concurrent patients who did not receive any neoadjuvant treatment prior to RP. The majority of infiltrating T cells were PD-1(+) and Ki-67(+), consistent with activated T cells. Importantly, the magnitude of the circulating immune response did not directly correlate with T cell infiltration within the prostate based upon Spearman's rank order correlation.ConclusionsThis study is the first to demonstrate a local immune effect from the administration of sipuleucel-T. Neoadjuvant sipuleucel-T elicits both a systemic antigen-specific T cell response and the recruitment of activated effector T cells into the prostate tumor microenvironment
Effectiveness of Computer Automation for the Diagnosis and Management of Childhood Type 2 Diabetes A Randomized Clinical Trial
Importance Type 2 diabetes (T2D) is increasingly common in young individuals. Primary prevention and screening among children and adolescents who are at substantial risk for T2D are recommended, but implementation of T2D screening practices in the pediatric primary care setting is uncommon.
Objective To determine the feasibility and effectiveness of a computerized clinical decision support system to identify pediatric patients at high risk for T2D and to coordinate screening for and diagnosis of prediabetes and T2D.
Design, Setting, and Participants This cluster-randomized clinical trial included patients from 4 primary care pediatric clinics. Two clinics were randomized to the computerized clinical decision support intervention, aimed at physicians, and 2 were randomized to the control condition. Patients of interest included children, adolescents, and young adults 10 years or older. Data were collected from January 1, 2013, through December 1, 2016.
Interventions Comparison of physician screening and follow-up practices after adding a T2D module to an existing computer decision support system.
Main Outcomes and Measures Electronic medical record (EMR) data from patients 10 years or older were reviewed to determine the rates at which pediatric patients were identified as having a body mass index (BMI) at or above the 85th percentile and 2 or more risk factors for T2D and underwent screening for T2D.
Results Medical records were reviewed for 1369 eligible children (712 boys [52.0%] and 657 girls [48.0%]; median [interquartile range] age, 12.9 [11.2-15.3]), of whom 684 were randomized to the control group and 685 to the intervention group. Of these, 663 (48.4%) had a BMI at or above the 85th percentile. Five hundred sixty-five patients (41.3%) met T2D screening criteria, with no difference between control and intervention sites. The T2D module led to a significant increase in the percentage of patients undergoing screening for T2D (89 of 283 [31.4%] vs 26 of 282 [9.2%]; adjusted odds ratio, 4.6; 95% CI, 1.5-14.7) and a greater proportion attending a scheduled follow-up appointment (45 of 153 [29.4%] vs 38 of 201 [18.9%]; adjusted odds ratio, 1.8; 95% CI, 1.5-2.2).
Conclusions and Relevance Use of a computerized clinical decision support system to automate the identification and screening of pediatric patients at high risk for T2D can help overcome barriers to the screening process. The support system significantly increased screening among patients who met the American Diabetes Association criteria and adherence to follow-up appointments with primary care clinicians
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