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Harvard, United States

Kalapurakkel S.,Harvard College | Carpino E.A.,Perioperative and Pain Medicine | Simons L.E.,Perioperative and Pain Medicine | Simons L.E.,Harvard University
Journal of Pediatric Psychology | Year: 2014

Objective To examine pain self-efficacy and pain acceptance in relation to functioning in pediatric patients with chronic headache. Methods Participants were 209 youth aged 8-17 years who presented for a multidisciplinary pediatric headache clinic evaluation. They completed measures of pain self-efficacy and pain acceptance and a standard battery of clinical measures including indicators of emotional functioning. Results Pain self-efficacy and acceptance were associated with less disability, better school functioning, and fewer depressive symptoms. While taking into account several demographic and pain-related variables, pain self-efficacy had a greater association with less functional disability, while pain acceptance had a greater association with less depressive symptoms and better school functioning. Conclusions These findings indicate that both resilience processes can serve to positively interact with functioning and symptoms of depression. Ultimately, this study suggests that higher levels of pain self-efficacy and pain acceptance in an individual experiencing pain are associated with more positive outcomes. © The Author 2014. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. Source

Raoof S.,Harvard University | Raoof S.,Harvard College | Heo M.,Pusan National University | Shakhnovich E.I.,Harvard University
Physical Biology | Year: 2013

The germinal center reaction is the process by which low-affinity B cells evolve into potent, immunoglobulin-secreting plasma and memory B cells. Since the recycling hypothesis was created, experimental studies have both tracked movement of a small population of B cells from the light zone into the dark zone, supporting the recycling model, and parallel to the light zone-dark zone interface, indicating a one-way trajectory. We present a novel, sequence-based ab initio model of protein stability and protein interactions. Our model contains a dark zone region of clonal expansion and somatic hypermutation and a light zone site of antigenic selection. We show not only that a one-shot model is sufficient to achieve biologically-realistic rates of affinity growth, population dynamics, and silent:non-silent mutation ratios in the complementary determining region and framework region of antibodies, but also that a stochastic recycling program with or without realistic constraints on the structural stabilities of GC antibodies cannot produce biologically-observed affinity growth, population dynamics or silent:non-silent mutation profiles. The effect of recycling erases affinity gains made by potent antibodies cycling back from the light zone and causes B cells to pool in the dark zone under high replication rates. © 2013 IOP Publishing Ltd. Source

Sovacool B.K.,National University of Singapore | Rafey W.,Harvard College
Electricity Journal | Year: 2011

The proposed 4,800 MW coal-fired power plant Medupi in South Africa demonstrates how different aspects of energy security can conflict with each other. © 2010 Elsevier Inc. Source

Gong J.J.,Harvard College
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference | Year: 2011

Understanding the physiological impact of drug treatments on patients is important in assessing their performance and determining possible side effects. While this effect might be best determined in individual subjects, conventional methods assess treatment performance by averaging a physiological measure of interest before and after drug administration for n subjects. Summarizing large numbers of time-series observations in two means for each subject in this way results in significant information loss. Treatment effect can instead be analyzed in individual subjects. Because serial dependence of observations from the same animal must then be considered, methods that assume independence of observations, such as the t-test and z-test, cannot be used. We address this issue in the case of respiratory data collected from anesthetized rats that were injected with a dopamine agonist. In order to accurately assess treatment effect in time-series data, we begin by formulating a method of conditional likelihood maximization to estimate the parameters of a first-order autoregressive (AR) process. We show that treatment effect of a dopamine agonist can be determined while incorporating serial effect into the analysis. In addition, while maximum likelihood estimators of a large sample with independent observations may converge to an asymptotically normal distribution, this result of large sample theory may not hold when observations are serially dependent. In this case, a parametric bootstrap comparison can be used to approximate an appropriate measure of uncertainty. Source

Agency: Department of Energy | Branch: | Program: STTR | Phase: Phase I | Award Amount: 0.00 | Year: 2003

70814B02-II Measurements of atmospheric concentrations of CO2 and CO from aircraft and from remote sites play a central role in observational strategies intended to quantify the sources and sinks of carbon and to control global warming from greenhouse gas emissions. Improved measurement techniques that are highly sensitive, automated, and robust are needed to quantify changes in the carbon content of the atmosphere and to assess mechanisms of exchange with the Earth¿s surface. This project will develop an instrument to measure CO2 and CO, using newly available ¿quantum cascade¿ lasers that operate in the mid-infrared spectral region without cryogenic cooling. Phase I demonstrated the feasibility of using near-room-temperature pulsed-quantum-cascade lasers and detectors for high precision absorbance measurements. A novel, dual-sampling cell ratio technique for CO2 was developed that could determine the difference between the two cells with a precision of 70 ppb. The capability to determine CO with a precision better than 1 ppb also was demonstrated. Phase II will design, construct, and demonstrate a prototype instrument for CO2 that can be deployed at ground-based, remote locations for continuous autonomous measurements. With optional supplemental Phase II funding, the instrument could be flight-hardened and deployed from an aircraft platform. Commercial Applications and Other Benefits as described by awardee: An improved instrument for CO2 measurements would be widely applicable to environmental and ecological research in addition to the measurement of atmospheric trace gases. A sensitive, cryogen-free, mid-infrared absorption spectrometer also would have commercial applications in medical diagnostics and industrial process monitoring for detecting a wide variety of gas phase molecules.

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