2,940 research outputs found
Erosion patterns in a sediment layer
We report here on a laboratory-scale experiment which reproduces a rich
variety of natural patterns with few control parameters. In particular, we
focus on intriguing rhomboid structures often found on sandy shores and flats.
We show that the standard views based on water surface waves come short to
explain the phenomenon and we evidence a new mechanism based on a mud avalanche
instability.Comment: 4 pages, 4 figures, to appear as Phys. Rev. E rapid com
Supporting Accurate Interpretation of Self-Administered Medical Test Results for Mobile Health: Assessment of Design, Demographics, and Health Condition
Background: Technological advances in personal informatics allow people to track their own health in a variety of ways, representing a dramatic change in individuals’ control of their own wellness. However, research regarding patient interpretation of traditional medical tests highlights the risks in making complex medical data available to a general audience.
Objective: This study aimed to explore how people interpret medical test results, examined in the context of a mobile blood testing system developed to enable self-care and health management.
Methods: In a preliminary investigation and main study, we presented 27 and 303 adults, respectively, with hypothetical results from several blood tests via one of the several mobile interface designs: a number representing the raw measurement of the tested biomarker, natural language text indicating whether the biomarker’s level was low or high, or a one-dimensional chart illustrating this level along a low-healthy axis. We measured respondents’ correctness in evaluating these results and their confidence in their interpretations. Participants also told us about any follow-up actions they would take based on the result and how they envisioned, generally, using our proposed personal health system.
Results: We find that a majority of participants (242/328, 73.8%) were accurate in their interpretations of their diagnostic results. However, 135 of 328 participants (41.1%) expressed uncertainty and confusion about their ability to correctly interpret these results. We also find that demographics and interface design can impact interpretation accuracy, including false confidence, which we define as a respondent having above average confidence despite interpreting a result inaccurately. Specifically, participants who saw a natural language design were the least likely (421.47 times, P=.02) to exhibit false confidence, and women who saw a graph design were less likely (8.67 times, P=.04) to have false confidence. On the other hand, false confidence was more likely among participants who self-identified as Asian (25.30 times, P=.02), white (13.99 times, P=.01), and Hispanic (6.19 times, P=.04). Finally, with the natural language design, participants who were more educated were, for each one-unit increase in education level, more likely (3.06 times, P=.02) to have false confidence.
Conclusions: Our findings illustrate both promises and challenges of interpreting medical data outside of a clinical setting and suggest instances where personal informatics may be inappropriate. In surfacing these tensions, we outline concrete interface design strategies that are more sensitive to users’ capabilities and conditions
On Four-Point Functions of Half-BPS Operators in General Dimensions
We study four-point correlation functions of half-BPS operators of arbitrary
weight for all dimensions d=3,4,5,6 where superconformal theories exist. Using
harmonic superspace techniques, we derive the superconformal Ward identities
for these correlators and present them in a universal form. We then solve these
identities, employing Jack polynomial expansions. We show that the general
solution is parameterized by a set of arbitrary two-variable functions, with
the exception of the case d=4, where in addition functions of a single variable
appear. We also discuss the operator product expansion using recent results on
conformal partial wave amplitudes in arbitrary dimension.Comment: The discussion of the case d=6 expanded; references added/correcte
The long-line graph of a combinatorial geometry. II. Geometries representable over two fields of different characteristics
AbstractLet q be a power of a prime and let s be zero or a prime not dividing q. Then the number of points in a combinatorial geometry (or simple matroid) of rank n which is representable over GF(q) and a field of characteristic s is at most (qν − qν−1)(2n+1)−n, where ν = 2q−1 − 1
Mechanical and physical properties of concrete containing FGD waste
The paper is part of a wide ranging research project on the optimum use of waste from the dry and
semi dry flue gas desulphurisation (FGD) processes in concrete. It examines the influence of a typical
simulated desulphurised waste (SDW) on the physical and mechanical and physical properties of
concrete. SDW was chosen due to the wider variability in the composition of actual FGD waste. Two
binder systems were investigated (i) cement and SDW (C-SDW) and (ii) cement, slag and SDW (C-SSDW).
The SDW content ranged from 0-70% and the slag from 0-90% as partial replacement of the
cement. The properties examined included compressive and flexural strength, water absorption,
shrinkage and expansion. The results showed that replacing cement with SDW beyond 20%
systematically reduce strength. An increase in SDW reduces shrinkage. The presence of small
amounts of slag allows the use of high proportions of SDW. The use of desulphurised waste in
concrete applications is possible as adequate strength can be achieved
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Charged particle irradiations in the United States Breeder Reactor Program
Charged particle irradiations used as a means of studying radiation damage in materials of interest in the US Breeder Reactor Program are reviewed
Modular Invariance and Characteristic Numbers
We show that a general miraculous cancellation formula, the divisibility of
certain characteristic numbers and some other topologiclal results are con-
sequences of the modular invariance of elliptic operators on loop spaces.
Previously we have shown that modular invariance also implies the rigidity of
many elliptic operators on loop spaces.Comment: 14 page
Some Systematics of the Coupling Constant Dependence of N=4 Yang-Mills
The operator, O_\tau, that generates infinitesimal changes of the coupling
constant in N=4 Yang-Mills sits in the same supermultiplet as the
superconformal currents. We show how superconformal current Ward identities
determine a class of terms in the operator product expansion of O_\tau with any
other operator. In certain cases, this leads to constraints on the coupling
dependence of correlation functions in N=4 Yang-Mills. As an application, we
demonstrate the exact non-renormalization of two and certain three-point
correlation functions of BPS operators.Comment: 56 pages, LaTeX; amended and expanded arguments, added reference
Pulmicort® turbohaler® once daily as initial prophylactic therapy for asthma
AbstractIn a double-blind, randomized, parallel-group clinical trial, 340 asthmatic patients aged 12–70 years received budesonide 400 μg once daily in the morning, budesonide 400 μg once daily in the evening, budesonide 200 μg twice daily or placebo, for 12 weeks in addition to inhaled short-acting β2-agonists used as required (p.r.n.). Budesonide was given as Pulmicort Turbohaler.Peak expiratory flow rate (PEFR) increased by 20 to 30 1 min−1 in each of the active treatment groups, significantly more than in the placebo group (P<0·01). There were no significant differences between the active treatment groups. Symptom improvement and decreased β2-agonist use reflected the PEFR data. Incidences of adverse events in the active treatment groups were similar to those observed in the placebo group.Budesonide 400 μg given once daily morning or evening is equieffective with the same total daily dose given twice daily in the treatment of mild to moderate stable asthmatics
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