538 research outputs found

    Harvest of Hope: The Impact of a Church Garden Project on African American Youth and Adults in the Rural American South

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    A pilot study was conducted of the feasibility of a church garden program to impact health outcomes in rural African American youth and adults. Thirty-six workdays were held at a black church. Pre- and postintervention attitudes, diet, weight, and blood pressure were measured. T-tests were used to test for significant within-group differences. Spearman’s rank correlation coefficients were used to test for significant bivariate associations. Youth showed improved attitudes about farming and gardening. No statistically significant changes were observed in adults. Church garden interventions can improve farming and gardening attitudes for rural African American youth

    Emergence of Anti-Cancer Drug Resistance: Exploring the Importance of the Microenvironmental Niche via a Spatial Model

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    Practically, all chemotherapeutic agents lead to drug resistance. Clinically, it is a challenge to determine whether resistance arises prior to, or as a result of, cancer therapy. Further, a number of different intracellular and microenvironmental factors have been correlated with the emergence of drug resistance. With the goal of better understanding drug resistance and its connection with the tumor microenvironment, we have developed a hybrid discrete-continuous mathematical model. In this model, cancer cells described through a particle-spring approach respond to dynamically changing oxygen and DNA damaging drug concentrations described through partial differential equations. We thoroughly explored the behavior of our self-calibrated model under the following common conditions: a fixed layout of the vasculature, an identical initial configuration of cancer cells, the same mechanism of drug action, and one mechanism of cellular response to the drug. We considered one set of simulations in which drug resistance existed prior to the start of treatment, and another set in which drug resistance is acquired in response to treatment. This allows us to compare how both kinds of resistance influence the spatial and temporal dynamics of the developing tumor, and its clonal diversity. We show that both pre-existing and acquired resistance can give rise to three biologically distinct parameter regimes: successful tumor eradication, reduced effectiveness of drug during the course of treatment (resistance), and complete treatment failure

    Presenting a simplified assistant tool for breast cancer diagnosis in mammography to radiologists

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    This paper proposes a method to simplify a computational model from logistic regression for clinical use without computer. The model was built using human interpreted featrues including some BI-RADS standardized features for diagnosing the malignant masses. It was compared with the diagnosis using only assessment categorization from BI-RADS. The research aims at assisting radiologists to diagnose the malignancy of breast cancer in a way without using automated computer aided diagnosis system

    A randomized controlled trial of the effectiveness of cognitive-behavioral therapy and sertraline versus a wait-list control group for anxiety disorders in older adults.

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    Objective: This study is the first to investigate the relative effectiveness of cognitive? behavioral therapy (CBT) compared with a selective serotonin reuptake inhibitor (SSRI; sertraline) in a randomized, controlled trial on the treatment of anxiety disorders in older adults. Method: Eighty-four patients 60 years of age and over with a principal diagnosis of generalized anxiety disorder, panic disorder, agoraphobia, or social phobia were randomly assigned to one of three conditions: 15 sessions of CBT, pharmacologic treatment with an SSRI (sertraline; maximum dosage 150 mg), or a waitlist control group. Participants completed measures of primary outcome (anxiety) and coexistent worry and depressive symptoms at baseline, posttreatment, and at three-month follow up. Results: Attrition rates were high in both treatment groups. Consequently, findings are based on a relatively small sample of completers (N=52). Although both CBT and sertraline led to significant improvement in anxiety, worry, and depressive symptoms both at posttreatment and at three-month follow up, sertraline showed superior results on worry symptoms. Effect size estimates for CBT were in the small to medium range both at posttreatment (mean d = 0.42) and at three-month follow up (mean d=0.35), whereas effect sizes for sertraline fell into the large range (posttreatment mean d = 0.94 and three-month follow up mean d= 1.02). The waitlist condition showed virtually no effects (posttreatment mean d = .03). Conclusions: Our findings strongly suggest that the pharmacologic treatment of late-life anxiety with SSRIs has not been given the proper attention in research to date

    Elastic Scattering Phenomenology

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    We argue that, in many situations, fits to elastic scattering data that were historically, and frequently still are, considered “good”, are not justifiably so describable. Information about the dynamics of nucleon-nucleus and nucleus-nucleus scattering is lost when elastic scattering phenomenology is insufficiently ambitious. It is argued that in many situations, an alternative approach is appropriate for the phenomenology of nuclear elastic scattering of nucleons and other light nuclei. The approach affords an appropriate means of evaluating folding models, one that fully exploits available empirical data. It is particularly applicable for nucleons and other light ions

    Magnetic Reconnection in Extreme Astrophysical Environments

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    Magnetic reconnection is a basic plasma process of dramatic rearrangement of magnetic topology, often leading to a violent release of magnetic energy. It is important in magnetic fusion and in space and solar physics --- areas that have so far provided the context for most of reconnection research. Importantly, these environments consist just of electrons and ions and the dissipated energy always stays with the plasma. In contrast, in this paper I introduce a new direction of research, motivated by several important problems in high-energy astrophysics --- reconnection in high energy density (HED) radiative plasmas, where radiation pressure and radiative cooling become dominant factors in the pressure and energy balance. I identify the key processes distinguishing HED reconnection: special-relativistic effects; radiative effects (radiative cooling, radiation pressure, and Compton resistivity); and, at the most extreme end, QED effects, including pair creation. I then discuss the main astrophysical applications --- situations with magnetar-strength fields (exceeding the quantum critical field of about 4 x 10^13 G): giant SGR flares and magnetically-powered central engines and jets of GRBs. Here, magnetic energy density is so high that its dissipation heats the plasma to MeV temperatures. Electron-positron pairs are then copiously produced, making the reconnection layer highly collisional and dressing it in a thick pair coat that traps radiation. The pressure is dominated by radiation and pairs. Yet, radiation diffusion across the layer may be faster than the global Alfv\'en transit time; then, radiative cooling governs the thermodynamics and reconnection becomes a radiative transfer problem, greatly affected by the ultra-strong magnetic field. This overall picture is very different from our traditional picture of reconnection and thus represents a new frontier in reconnection research.Comment: Accepted to Space Science Reviews (special issue on magnetic reconnection). Article is based on an invited review talk at the Yosemite-2010 Workshop on Magnetic Reconnection (Yosemite NP, CA, USA; February 8-12, 2010). 30 pages, no figure

    Human upper-airway respiratory airflow: In vivo comparison of computational fluid dynamics simulations and hyperpolarized 129Xe phase contrast MRI velocimetry

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    Computational fluid dynamics (CFD) simulations of respiratory airflow have the potential to change the clinical assessment of regional airway function in health and disease, in pulmonary medicine and otolaryngology. For example, in diseases where multiple sites of airway obstruction occur, such as obstructive sleep apnea (OSA), CFD simulations can identify which sites of obstruction contribute most to airway resistance and may therefore be candidate sites for airway surgery. The main barrier to clinical uptake of respiratory CFD to date has been the difficulty in validating CFD results against a clinical gold standard. Invasive instrumentation of the upper airway to measure respiratory airflow velocity or pressure can disrupt the airflow and alter the subject’s natural breathing patterns. Therefore, in this study, we instead propose phase contrast (PC) velocimetry magnetic resonance imaging (MRI) of inhaled hyperpolarized 129Xe gas as a non-invasive reference to which airflow velocities calculated via CFD can be compared. To that end, we performed subject-specific CFD simulations in airway models derived from 1H MRI, and using respiratory flowrate measurements acquired synchronously with MRI. Airflow velocity vectors calculated by CFD simulations were then qualitatively and quantitatively compared to velocity maps derived from PC velocimetry MRI of inhaled hyperpolarized 129Xe gas. The results show both techniques produce similar spatial distributions of high velocity regions in the anterior-posterior and foot-head directions, indicating good qualitative agreement. Statistically significant correlations and low Bland-Altman bias between the local velocity values produced by the two techniques indicates quantitative agreement. This preliminary in vivo comparison of respiratory airway CFD and PC MRI of hyperpolarized 129Xe gas demonstrates the feasibility of PC MRI as a technique to validate respiratory CFD and forms the basis for further comprehensive validation studies. This study is therefore a first step in the pathway towards clinical adoption of respiratory CFD

    Initial feasibility and challenges of hyperpolarized 129Xe MRI in neonates with bronchopulmonary dysplasia

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    Purpose The underlying functional and microstructural lung disease in neonates who are born preterm (bronchopulmonary dysplasia, BPD) remains poorly characterized. Moreover, there is a lack of suitable techniques to reliably assess lung function in this population. Here, we report our preliminary experience with hyperpolarized 129Xe MRI in neonates with BPD. Methods Neonatal intensive care patients with established BPD were recruited (N = 9) and imaged at a corrected gestational age of median:40.7 (range:37.1, 44.4) wk using a 1.5T neonatal scanner. 2D 129Xe ventilation and diffusion-weighted images and dissolved phase spectroscopy were acquired, alongside 1H 3D radial UTE. 129Xe images were acquired during a series of short apneic breath-holds (˜3 s). 1H UTE images were acquired during tidal breathing. Ventilation defects were manually identified and qualitatively compared to lung structures on UTE. ADCs were calculated on a voxel-wise basis. The signal ratio of the 129Xe red blood cell (RBC) and tissue membrane (M) resonances from spectroscopy was determined. Results Spiral-based 129Xe ventilation imaging showed good image quality and sufficient sensitivity to detect mild ventilation abnormalities in patients with BPD. 129Xe ADC values were elevated above that expected given healthy data in older children and adults (median:0.046 [range:0.041, 0.064] cm2s−1); the highest value obtained from an extremely pre-term patient. 129Xe spectroscopy revealed a low RBC/M ratio (0.14 [0.06, 0.21]). Conclusion We have demonstrated initial feasibility of 129Xe lung MRI in neonates. With further data, the technique may help guide management of infant lung diseases in the neonatal period and beyond

    Financial Toxicity among Patients with Bladder Cancer: Reasons for Delay in Care and Effect on Quality of Life

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    Purpose: Costly surveillance and treatment of bladder cancer can lead to financial toxicity, a treatment related financial burden. Our objective was to define the prevalence of financial toxicity among patients with bladder cancer and identify delays in care and its effect on health related quality of life. Materials and Methods: We identified patients with bladder cancer in the University of North Carolina Health Registry/Cancer Survivorship Cohort. Financial toxicity was defined as agreement with having “to pay more for medical care than you can afford.” Health related quality of life was measured using general and cancer specific validated questionnaires. Statistical analyses were performed using the Fisher exact test and the Student t-test. Results: A total of 138 patients with bladder cancer were evaluated. Median age was 66.9 years, 75% of the patients were male and 89% were white. Of the participants 33 (24%) endorsed financial toxicity. Participants who were younger (p = 0.02), black (p = 0.01), reported less than a college degree (p = 0.01) and had noninvasive disease (p = 0.04) were more likely to report financial toxicity. On multivariable analysis only age was a significant predictor of financial toxicity. Patients who endorsed financial toxicity were more likely to report delaying care (39% vs 23%, p = 0.07) due to the inability to take time off work or afford general expenses. On general health related quality of life questionnaires patients with financial toxicity reported worse physical and mental health (p = 0.03 and <0.01, respectively), and lower cancer specific health related quality of life (p = 0.01), physical well-being (p = 0.01) and functional well-being (p = 0.05). Conclusions: Financial toxicity is a major concern among patients with bladder cancer. Younger patients were more likely to experience financial toxicity. Those who endorsed financial toxicity experienced delays in care and poorer health related quality of life, suggesting that treatment costs should have an important role in medical decision making
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