1,647 research outputs found
The North Carolina A and T State University Student Space Shuttle Program
Inspired into being in 1979 by the late astronaut, Dr. Ronald McNair, the primary goal of this student centered program is to perform two experiments, Arthopod Development Study and Crystal Growth Study. Since 1979, 78 different students representing 12 majors have participated in every phase of development of the payload -- from coming up with the original ideas to final fabrication and testing. Students have also been involved in many extra activities such as presenting their results at annual meetings and hosting tours of our lab for local schools. The program has received extensive outside support in the form of funds, technical assistance and donated parts. The payload, made primarily out of aluminum, consists of a central column structure, a battery box, a crystal growth box, an arthropod development box, four control circuit boxes, and a thermograph box. The battery box contains 24, Eveready 6V, Alkaline batteries. The thermograph box contains 3 Ryan TempMentors. Fabrication of the payload is essentially complete and a complete testing program has been initiated
Functional generalized additive models
We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F{X(t), t} where F(·, ·) is an unknown regression function and X(t) is a functional covariate. Rather than having an additive model in a finite number of principal components as by Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F(·, ·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X(t) is a signal from diffusion tensor imaging at position, t, along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. The FGAM is implemented in R in the refund package. There are additional supplementary materials available online. © 2013 American Statistical Association, Institute of Mathematical Statistics, and Interface Foundation of North America
Bayesian Functional Generalized Additive Models with Sparsely Observed Covariates
The functional generalized additive model (FGAM) was recently proposed in McLean et al. (2013) as a more flexible alternative to the common functional linear model (FLM) for regressing a scalar on functional covariates. In this paper, we develop a Bayesian version of FGAM for the case of Gaussian errors with identity link function. Our approach allows the functional covariates to be sparsely observed and measured with error, whereas the estimation procedure of McLean et al. (2013) required that they be noiselessly observed on a regular grid. We consider both Monte Carlo and variational Bayes methods for fitting the FGAM with sparsely observed covariates. Due to the complicated form of the model posterior distribution and full conditional distributions, standard Monte Carlo and variational Bayes algorithms cannot be used. The strategies we use to handle the updating of parameters without closed-form full conditionals should be of independent interest to applied Bayesian statisticians working with nonconjugate models. Our numerical studies demonstrate the benefits of our algorithms over a two-step approach of first recovering the complete trajectories using standard techniques and then fitting a functional regression model. In a real data analysis, our methods are applied to forecasting closing price for items up for auction on the online auction website eBay
Enhanced He-alpha emission from "smoked" Ti targets irradiated with 400nm, 45 fs laser pulses
We present a study of He-like 1s(2)-1s2p line emission from solid and low-density Ti targets under similar or equal to 45 fs laser pulse irradiation with a frequency doubled Ti: Sapphire laser. By varying the beam spot, the intensity on target was varied from 10(15) W/cm(2) to 10(19) W/cm(2). At best focus, low density "smoked" Ti targets yield similar to 20 times more He-alpha than the foil targets when irradiated at an angle of 45 degrees with s-polarized pulses. The duration of He-alpha emission from smoked targets, measured with a fast streak camera, was similar to that from Ti foils
Development and validation of the BRIGHTLIGHT Survey, a patient-reported experience measure for young people with cancer
BACKGROUND: Patient experience is increasingly used as an indicator of high quality care in addition to more traditional clinical end-points. Surveys are generally accepted as appropriate methodology to capture patient experience. No validated patient experience surveys exist specifically for adolescents and young adults (AYA) aged 13-24 years at diagnosis with cancer. This paper describes early work undertaken to develop and validate a descriptive patient experience survey for AYA with cancer that encompasses both their cancer experience and age-related issues. We aimed to develop, with young people, an experience survey meaningful and relevant to AYA to be used in a longitudinal cohort study (BRIGHTLIGHT), ensuring high levels of acceptability to maximise study retention. METHODS: A three-stage approach was employed: Stage 1 involved developing a conceptual framework, conducting literature/Internet searches and establishing content validity of the survey; Stage 2 confirmed the acceptability of methods of administration and consisted of four focus groups involving 11 young people (14-25 years), three parents and two siblings; and Stage 3 established survey comprehension through telephone-administered cognitive interviews with a convenience sample of 23 young people aged 14-24 years. RESULT: Stage 1: Two-hundred and thirty eight questions were developed from qualitative reports of young people's cancer and treatment-related experience. Stage 2: The focus groups identified three core themes: (i) issues directly affecting young people, e.g. impact of treatment-related fatigue on ability to complete survey; (ii) issues relevant to the actual survey, e.g. ability to answer questions anonymously; (iii) administration issues, e.g. confusing format in some supporting documents. Stage 3: Cognitive interviews indicated high levels of comprehension requiring minor survey amendments. CONCLUSION: Collaborating with young people with cancer has enabled a survey of to be developed that is both meaningful to young people but also examines patient experience and outcomes associated with specialist cancer care. Engagement of young people throughout the survey development has ensured the content appropriately reflects their experience and is easily understood. The BRIGHTLIGHT survey was developed for a specific research project but has the potential to be used as a TYA cancer survey to assess patient experience and the care they receive
Multiple‐Path Technique for the Determination of Physico‐Chemical Data Behind Shock Fronts
Specialist cancer services for teenagers and young adults in England: BRIGHTLIGHT research programme
Background: When cancer occurs in teenagers and young adults, the impact is far beyond the physical disease and treatment burden. The effect on psychological, social, educational and other normal development can be profound. In addition, outcomes including improvements in survival and participation in clinical trials are poorer than in younger children and older adults with similar cancers. These unique circumstances have driven the development of care models specifically for teenagers and young adults with cancer, often focused on a dedicated purpose-designed patient environments supported by a multidisciplinary team with expertise in the needs of teenagers and young adults. In England, this is commissioned by NHS England and delivered through 13 principal treatment centres. There is a lack of evaluation that identifies the key components of specialist care for teenagers and young adults, and any improvement in outcomes and costs associated with it. /
Objective: To determine whether or not specialist services for teenagers and young adults with cancer add value. /
Design: A series of multiple-methods studies centred on a prospective longitudinal cohort of teenagers and young adults who were newly diagnosed with cancer. /
Settings: Multiple settings, including an international Delphi study of health-care professionals, qualitative observation in specialist services for teenagers and young adults, and NHS trusts. /
Participants: A total of 158 international teenage and young adult experts, 42 health-care professionals from across England, 1143 teenagers and young adults, and 518 caregivers. /
Main outcome measures: The main outcomes were specific to each project: key areas of competence for the Delphi survey; culture of teenagers and young adults care in the case study; and unmet needs from the caregiver survey. The primary outcome for the cohort participants was quality of life and the cost to the NHS and patients in the health economic evaluation. /
Data sources: Multiple sources were used, including responses from health-care professionals through a Delphi survey and face-to-face interviews, interview data from teenagers and young adults, the BRIGHTLIGHT survey to collect patient-reported data, patient-completed cost records, hospital clinical records, routinely collected NHS data and responses from primary caregivers. /
Results: Competencies associated with specialist care for teenagers and young adults were identified from a Delphi study. The key to developing a culture of teenage and young adult care was time and commitment. An exposure variable, the teenagers and young adults Cancer Specialism Scale, was derived, allowing categorisation of patients to three groups, which were defined by the time spent in a principal treatment centre: SOME (some care in a principal treatment centre for teenagers and young adults, and the rest of their care in either a children’s or an adult cancer unit), ALL (all care in a principal treatment centre for teenagers and young adults) or NONE (no care in a principal treatment centre for teenagers and young adults). The cohort study showed that the NONE group was associated with superior quality of life, survival and health status from 6 months to 3 years after diagnosis. The ALL group was associated with faster rates of quality-of-life improvement from 6 months to 3 years after diagnosis. The SOME group was associated with poorer quality of life and slower improvement in quality of life over time. Economic analysis revealed that NHS costs and travel costs were similar between the NONE and ALL groups. The ALL group had greater out-of-pocket expenses, and the SOME group was associated with greater NHS costs and greater expense for patients. However, if caregivers had access to a principal treatment centre for teenagers and young adults (i.e. in the ALL or SOME groups), then they had fewer unmet support and information needs. /
Limitations: Our definition of exposure to specialist care using Hospital Episode Statistics-determined time spent in hospital was insufficient to capture the detail of episodes or account for the variation in specialist services. Quality of life was measured first at 6 months, but an earlier measure may have shown different baselines. /
Conclusions: We could not determine the added value of specialist cancer care for teenagers and young adults as defined using the teenage and young adult Cancer Specialism Scale and using quality of life as a primary end point. A group of patients (i.e. those defined as the SOME group) appeared to be less advantaged across a range of outcomes. There was variation in the extent to which principal treatment centres for teenagers and young adults were established, and the case study indicated that the culture of teenagers and young adults care required time to develop and embed. It will therefore be important to establish whether or not the evolution in services since 2012–14, when the cohort was recruited, improves quality of life and other patient-reported and clinical outcomes. /
Future work: A determination of whether or not the SOME group has similar or improved quality of life and other patient-reported and clinical outcomes in current teenage and young adult service delivery is essential if principal treatment centres for teenagers and young adults are being commissioned to provide ‘joint care’ models with other providers. /
Funding: This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 12. See the NIHR Journals Library website for further project information
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