30,709 research outputs found
Intraocular Pressure Fluctuation: Is It Important?
Elevated intraocular pressure (IOP) is a major risk factor for the development and progression of glaucoma. Previous prospective, randomized, long-term studies have demonstrated the strength of IOP reduction in slowing the progression of disease. It is well known that IOP is not a fixed value but fluctuates considerably over time. Although there have been some studies on IOP fluctuation and the progression of glaucoma, whether IOP fluctuation is an independent risk factor for glaucomatous damage and disease progression remains controversial. In this article, we reviewed the definition of IOP fluctuation, and both the evidence and the speculation for and against the effect of IOP fluctuation on glaucoma progression. Although conclusions seem to vary from study to study, we considered that different studies examined different groups of patients, at different stages of disease, and at different IOP levels. Our conclusion is that these apparently disparate results are not conflicting, but rather can be viewed as complementary. In clinical care, we recommend the consideration of IOP "modulation" rather than just IOP "reduction" when glaucoma patients are treated. Quality-based IOP control may be more effective than quantity-based IOP reduction to prevent or retard disease progression
Optimal Efficiency of Self-Assembling Light-Harvesting Arrays
Using a classical master equation that describes energy transfer over a given
lattice, we explore how energy transfer efficiency along with the photon
capturing ability depends on network connectivity, on transfer rates, and on
volume fractions - the numbers and relative ratio of fluorescence chromophore
components, e.g., donor (D), acceptor (A), and bridge (B) chromophores. For a
one-dimensional AD array, the exact analytical expression for efficiency shows
a steep increase with a D-to-A transfer rate when a spontaneous decay is
sufficiently slow. This result implies that the introduction of B chromophores
can be a useful method for improving efficiency for a two-component AD system
with inefficient D-to-A transfer and slow spontaneous decay. Analysis of this
one-dimensional system can be extended to higher-dimensional systems with
chromophores arranged in structures such as a helical or stacked-disk rod,
which models the self-assembling monomers of the tobacco mosaic virus coat
protein. For the stacked-disk rod, we observe the following: (1) With spacings
between sites fixed, a staggered conformation is more efficient than an
eclipsed conformation. (2) For a given ratio of A and D chromophores, the
uniform distribution of acceptors that minimizes the mean first passage time to
acceptors is a key point to designing the optimal network for a donor-acceptor
system with a relatively small D-to-A transfer rate. (3) For a three-component
ABD system with a large B-to-A transfer rate, a key design strategy is to
increase the number of the pathways in accordance with the directional energy
flow from D to B to A chromophores.Comment: 9 pages, 6 figure
A STUDY OF LUDWIG VAN BEETHOVEN’S PIANO SONATA OP. 111, ROBERT SCHUMANN’S OP.6 AND MAURICE RAVEL’S JEUX D’EAU
This research paper examines the following repertoire: Jeux d\u27eau by Maurice Ravel, Davidsbündertänze, Opus 6, by Robert Schumann, and Piano Sonata in C minor, Opus 111, by Ludwig van Beethoven. The purpose of this paper is to enhance performers’ understanding and performance of these pieces. By analyzing these works, this paper suggests that the performer delve more deeply into the structure and meaning behind this repertoire
Measuring Willingness to Accept for GM Food by Characteristics
Korean consumers' willingness to accept (WTA) for GM food are studied in this paper. This study compares hypothetical and nonhypothetical responses to choice experiment questions. We test for hypothetical bias in a choice experiment involving GM rice with differing characteristic attributes and multinomial logit model is applied to predict the estimated results. In general, hypothetical responses predicted higher probabilities of purchasing GM rice than nonhypothetical responses. Thus, hypothetical choices overestimate willingness to accept for GM rice. The results of this paper could contributes to government's GM food policies and subsequent studies, also improving economic welfare of farmers and consumers.GM Food, Willingness to Accept, Choice experiment, Hypothetical bias, Food Consumption/Nutrition/Food Safety,
Competing Magnetic Orderings and Tunable Topological States in Two-Dimensional Hexagonal Organometallic Lattices
The exploration of topological states is of significant fundamental and
practical importance in contemporary condensed matter physics, for which the
extension to two-dimensional (2D) organometallic systems is particularly
attractive. Using first-principles calculations, we show that a 2D hexagonal
triphenyl-lead lattice composed of only main group elements is susceptible to a
magnetic instability, characterized by a considerably more stable
antiferromagnetic (AFM) insulating state rather than the topologically
nontrivial quantum spin Hall state proposed recently. Even though this AFM
phase is topologically trivial, it possesses an intricate emergent degree of
freedom, defined by the product of spin and valley indices, leading to Berry
curvature-induced spin and valley currents under electron or hole doping.
Furthermore, such a trivial band insulator can be tuned into a topologically
nontrivial matter by the application of an out-of-plane electric field, which
destroys the AFM order, favoring instead ferrimagnetic spin ordering and a
quantum anomalous Hall state with a non-zero topological invariant. These
findings further enrich our understanding of 2D hexagonal organometallic
lattices for potential applications in spintronics and valleytronics.Comment: 9 pages, 8 figure
General music teachers' practices of cooperative learning in two elementary music classrooms
The purpose of the study was to examine general music teachers’ practices of cooperative learning in two elementary music classrooms. Using the intrinsic case study method, I examined elementary general music teachers’ perspectives on cooperative learning, the utilization of cooperative learning in their general music classrooms, and the challenges the music educators faced in creating and implementing cooperative learning.
I selected one general music classroom in two elementary schools in Boston, Massachusetts—totaling two general music teachers from different schools. I conducted eight class observations and three interviews for each participant during the fall 2016 semester. From separate and cross-case analyses, I found the following: (1) the two teachers’ instructions were linked to the characteristics of cooperative learning, (2) they believed that cooperative learning provided opportunities to improve students’ academic development in music and promote positive interpersonal relationships, and (3) both teachers used their own strategies for cooperative learning in order to maximize students’ learning. These findings provided evidence that cooperative learning engaged students in the process of learning music and, in addition, fostered positive interpersonal relationships. Moreover, this study suggested that music educators might undertake an effort to thoroughly understand students’ cognitive development when they wish utilize cooperative learning. Although this study was subject to a number of limitations due to its scope, the findings may contribute to the body of research on cooperative learning in elementary music education
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