16,304 research outputs found

    Patient preferences for adjuvant radiotherapy in early breast cancer are strongly influenced by treatment received through random assignment

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    Objective: TARGIT‐A randomised women with early breast cancer to receive external beam radiotherapy (EBRT) or intraoperative radiotherapy (TARGIT‐IORT). This study aimed to identify what extra risk of recurrence patients would accept for per‐ ceived benefits and risks of different radiotherapy treatments. Methods: Patient preferences were determined by self‐rated trade‐off question‐ naires in two studies: Stage (1) 209 TARGIT‐A participants (TARGIT‐IORT n = 108, EBRT n = 101); Stage (2) 123 non‐trial patients yet to receive radiotherapy (pre‐treat‐ ment group), with 85 also surveyed post‐radiotherapy. Patients traded‐off risks of local recurrence in preference selection between TARGIT‐IORT and EBRT. Results: TARGIT‐IORT patients were more accepting of IORT than EBRT patients with 60% accepting the highest increased risk presented (4%–6%) compared to 12% of EBRT patients, and 2% not accepting IORT at all compared to 43% of EBRT pa‐ tients. Pre‐treatment patients were more accepting of IORT than post‐treatment pa‐ tients with 23% accepting the highest increased risk presented compared to 15% of post‐treatment patients, and 15% not accepting IORT at all compared to 41% of pre‐ treatment patients. Conclusions: Breast cancer patients yet to receive radiotherapy accept a higher recurrence risk than the actual risk found in TARGIT‐A. Measured patient preferences are highly influenced by experience of treatment received. This finding challenges the validity of post‐treatment preference studies

    Comparison of the Caregiving Experience of Grief, Burden, and Quality of Life in Dementia with Lewy Bodies, Alzheimer’s Disease, and Parkinson’s Disease Dementia

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    Background: Caregivers of persons living with Alzheimer’s disease (AD), dementia with Lewy bodies (DLB), and Parkinson’s disease dementia (PDD) are faced with numerous challenges. However, little is known about the caregiving experience across different dementias. Objective: The aims of this cross-sectional study were to examine the differences in the caregiver experience between DLB, PDD, and AD. Methods: Respondents were caregivers (N = 515; 384 DLB, 69 AD, 62 PDD) who completed a 230-question survey including sociodemographics, disease severity, neuropsychiatric symptoms, and measures of grief, burden, depression, quality of life, social support, well-being, care confidence, and mastery/self-efficacy. Results: There were no differences in caregiver age, sex, race, or education, or in the distribution of disease severity between diagnostic groups. Constructs were highly intercorrelated with positive attributes (caregiver QoL, care recipient QoL, social support, well-being, mastery and care confidence) being inversely correlated with negative attributes (burden, grief, and depression). Across dementia etiologies, no differences were reported for quality of life, social support, depression, well-being, psychological well-being, mastery, care confidence, burden or grief. Instead, we found that the caregiver’s experience was dependent on caregiver characteristics, person living with dementia characteristics and their most disturbing symptom, with behavior, personality changes, and sleep having the greatest effect on constructs. Conclusion: Caregiver ratings of psychosocial constructs may be more dependent on care recipient-caregiver dyad characteristics and the current symptoms than the underlying cause of those symptoms. Interventions to improve the caregiving experience should be developed to address specific psychosocial constructs rather than focusing on disease etiology or stage

    Replicability of nitrogen recommendations from ramped calibration strips in winter wheat

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    Ramped calibration strips have been suggested as a way for grain producers to determine nitrogen needs more accurately. The strips use incrementally increasing levels of nitrogen and enable producers to conduct an experiment in each field to determine nitrogen needs. This study determines whether predictions from the program Ramp Analyzer 1.2 are replicable in Oklahoma hard red winter wheat (Triticum aestivum). Predictions are derived from 36 individual strips from on-farm experiments—two pairs of adjacent strips at each of nine winter wheat fields in Canadian County, OK. The two pairs of strips within each field were between 120 and 155 m apart. Each strip was analyzed three times during the 2006–2007 growing season. Nitrogen recommendations from Ramp Analyzer 1.2 are not correlated even for strips that were placed side by side, and recommendations from strips in the same field show no more homogeneity than randomly selected strips throughout the county. The results indicate that ramped calibration strips are unlikely to produce accurate nitrogen requirement predictions at any spatial scale, whether at the county level or for subsections of a single field. In contrast, a procedure that uses only measures from the plot with no nitrogen and the plot with the highest level of nitrogen applied does show replicability. Thus, improvements in the ramped calibration strip technology are needed if it is to become viable.Fertilizer; Nitrogen; Precision agriculture; Ramped calibration strip; Winter wheat

    Physics of Rheologically-Enhanced Propulsion: Different Strokes in Generalized Stokes

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    Shear-thinning is an important rheological property of many biological fluids, such as mucus, whereby the apparent viscosity of the fluid decreases with shear. Certain microscopic swimmers have been shown to progress more rapidly through shear-thinning fluids, but is this behavior generic to all microscopic swimmers, and what are the physics through which shear-thinning rheology affects a swimmer's propulsion? We examine swimmers employing prescribed stroke kinematics in two-dimensional, inertialess Carreau fluid: shear-thinning "Generalized Stokes" flow. Swimmers are modeled, using the method of femlets, by a set of immersed, regularized forces. The equations governing the fluid dynamics are then discretized over a body-fitted mesh and solved with the finite element method. We analyze the locomotion of three distinct classes of microswimmer: (1) conceptual swimmers comprising sliding spheres employing both one- and two-dimensional strokes, (2) slip-velocity envelope models of ciliates commonly referred to as "squirmers" and (3) monoflagellate pushers, such as sperm. We find that morphologically identical swimmers with different strokes may swim either faster or slower in shear-thinning fluids than in Newtonian fluids. We explain this kinematic sensitivity by considering differences in the viscosity of the fluid surrounding propulsive and payload elements of the swimmer, and using this insight suggest two reciprocal sliding sphere swimmers which violate Purcell's Scallop theorem in shear-thinning fluids. We also show that an increased flow decay rate arising from shear-thinning rheology is associated with a reduction in the swimming speed of slip-velocity squirmers. For sperm-like swimmers, a gradient of thick to thin fluid along the flagellum alters the force it exerts upon the fluid, flattening trajectories and increasing instantaneous swimming speed.Comment: 22 pages, 28 figure

    Measuring the world city network: new results and developments

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    Gravitational oscillations of a liquid column

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    We report gravity oscillations of a liquid column partially immersed in a bath of liquid. We stress in particular some peculiarities of this system, namely (i) the fact that the mass of this oscillator constantly changes with time; (ii) the singular character of the beginning of the rise, for which the mass of the oscillator is zero; (iii) the sources of dissipation in this system, which is found to be dominated at low viscosity by the entrance (or exit) effects, leading to a long-range damping of the oscillations. We conclude with some qualitative description of a second-order phenomenon, namely the eruption of a jet at the beginning of the rise.Comment: 22 pages, pdf. Submitted to Physics of Fluid
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