910 research outputs found

    New empirical equations for calculating sound pressure levels in rooms

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    Six room acoustic models were reviewed in the existing literature. There was no single acoustical model that was satisfactory for the rooms whose geometric and acoustic characteristics were different. In order to develop a new empirical room equation to predict the sound pressure distribution in rooms, seventeen rooms whose volumes ranged from 2,671 ft{dollar}\sp3{dollar} to 149,000 ft{dollar}\sp3{dollar} were examined. Two sets of sound tests, reverberation times and sound pressure levels, were conducted in these rooms. After a data base was built up, regression analyses were made. Finally, two empirical room acoustic equations, one for small rooms and another for large rooms, were developed from final regressions. These empirical room acoustic equations were simple, but with in acceptable accuracy. A graphical comparison with Schultz\u27s equation and field measured L{dollar}\sb{\rm p}{dollar}-L{dollar}\sb{\rm w}{dollar} was also conducted

    Sexual size dimorphism in anurans: roles of mating system and habitat types

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    BACKGROUND: Sexual size dimorphism (SSD) is widespread and variable among animals. Sexual selection, fecundity selection and ecological divergence between males and females are the major evolutionary forces of SSD. However, the influences of mating system and habitat types on SSD have received little attention. Here, using phylogenetic comparative methods, we at first examine the hypotheses to that mating system (intensity of sexual selection) and habitat types affect significantly variation in SSD in anurans (39 species and 18 genera). RESULTS: Our data set encompass 39 species with female-biased SSD. We provide evidence that the effects of mating system and habitat types on SSD were non-significant across species, also when the analyses were phylogenetically corrected. CONCLUSIONS: Contrast to the hypotheses, our findings suggest that mating system and habitat types do not play an important role in shaping macro-evolutionary patterns of SSD in anurans. Mating system and habitat types cannot explain the variation in SSD when correcting for phylogenetic effects

    Efficacy of Ultrasound-guided Radiofrequency Ablation of Parathyroid Hyperplasia: Single Session vs. Two-Session for Effect on Hypocalcemia

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    To evaluate safety and efficacy of one- vs. two-session radiofrequency ablation (RFA) of parathyroid hyperplasia for patients with secondary hyperparathyroidism (SHPT) and to compare the outcome of both methods on hypocalcemia. Patients with secondary hyperparathyroidism underwent ultrasound guided RFA of parathyroid hyperplasia. Patients were alternately assigned to either group 1 (n = 28) with RFA of all 4 glands in one session or group 2 (n = 28) with RFA of 2 glands in a first session and other 2 glands in a second session. Serum parathyroid hormone (PTH), calcium, phosphorus and alkaline phosphatase (ALP) values were measured at a series of time points after RFA. RFA parameters, including operation duration and ablation time and hospitalization length and cost, were compared between the two groups. Mean PTH decreased in group 1 from 1865.18 ± 828.93 pg/ml to 145.72 ± 119.27 pg/ml at 1 day after RFA and in group 2 from 2256.64 ± 1021.72 pg/ml to 1388.13 ± 890.15 pg/ml at 1 day after first RFA and to 137.26 ± 107.12 pg/ml at 1 day after second RFA. Group 1\u27s calcium level decreased to 1.79 ± 0.31 mmol/L at day 1 after RFA and group 2 decreased to 1.89 ± 0.26 mmol/L at day 1 after second session RFA (P \u3c 0.05). Multivariate analysis showed that hypocalcemia was related to serum ALP. Patients with ALP ≥ 566 U/L had lower calcium compared to patients with ALP \u3c 566 U/L up to a month after RFA (P \u3c 0.05). Group 1\u27s RFA time and hospitalization were shorter and had lower cost compared with Group 2. US-guided RFA of parathyroid hyperplasia is a safe and effective method for treating secondary hyperparathyroidism. Single-session RFA was more cost-effective and resulted in a shorter hospital stay compared to two sessions. However, patients with two-session RFA had less hypocalcemia, especially those with high ALP

    A Fatty Acid Glycoside from a Marine-Derived Fungus Isolated from Mangrove Plant Scyphiphora hydrophyllacea

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    To study the antimicrobial components from the endophytic fungus A1 of mangrove plant Scyphiphora hydrophyllacea Gaertn. F., a new fatty acid glucoside was isolated by column chromatography from the broth of A1, and its structure was identified as R-3-hydroxyundecanoic acid methylester-3-O-α-l-rhamnopyranoside (1) by spectroscopic methods including 1D and 2D NMR (HMQC, 1H-1H COSY and HMBC) and chemical methods. Antimicrobial assay showed compound 1 possessed modest inhibitory effect on Saphylococcus aureus and methicillin-resistant S. aureus (MRSA) using the filter paper disc agar diffusion method

    Demonstrating anyonic fractional statistics with a six-qubit quantum simulator

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    Anyons are exotic quasiparticles living in two dimensions that do not fit into the usual categories of fermions and bosons, but obey a new form of fractional statistics. Following a recent proposal [Phys. Rev. Lett. 98, 150404 (2007)], we present an experimental demonstration of the fractional statistics of anyons in the Kitaev spin lattice model using a photonic quantum simulator. We dynamically create the ground state and excited states (which are six-qubit graph states) of the Kitaev model Hamiltonian, and implement the anyonic braiding and fusion operations by single-qubit rotations. A phase shift of π\pi related to the anyon braiding is observed, confirming the prediction of the fractional statistics of Abelian 1/2-anyons.Comment: revised version 3, revTex, 4.3 pages, 4 figures, notes and reference adde

    BurnCalc assessment study of computer-aided individual three-dimensional burn area calculation

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    BACKGROUND: Accurate estimation of a burned area is crucial to decisions about fluid resuscitation, surgical options, nutritional support, and prognosis. Widely used clinical methods to estimate a burn area are two-dimensional. They do not consider age, sex, body mass, physical deformities, or other relevant factors. Computer-aided methods have improved the accuracy of estimating burned areas by including data analysis and reducing subjective differences. Three-dimensional (3D) scanning allows us to determine body dimensions rapidly and reproducibly. We describe an individualized, cost-efficient, portable 3D scanning system, BurnCalc, that can create an individual 3D model and then calculate body surface area (BSA) and the burn area accurately and quickly. METHODS: The BurnCalc system was validated by verifying the accuracy and stability of BSA calculation. We measured 10 regular objects in experiment 1, using Student’s t-test and the intraclass correlation coefficient (ICC) in the analysis. In experiment 2, artificial paper patches of known dimensions were attached to various parts of the body of 40 volunteers. Their sizes were then calculated using BurnCalc. The BurnCalc data were compared to actually measured values to verify accuracy and stability. Total BSAs of these 40 volunteers were also calculated by BurnCalc and compared to those derived from an accepted formula. In experiment 3, four experts using Chinese Rule-of-Nines or Rule-of-Palms methods calculated the percentages of the total BSA in 17 volunteers. Student’s t-test and ICC, respectively, were used to compare the results obtained with the BurnCalc technique. RESULTS: Statistically, in experiment 1, p = 0.834 and ICC = 0.999, demonstrating that there was no difference between the BurnCalc and real measurements. Also, the hypothesis of null difference among measures (experiment 2) was true because p > 0.05 and ICC = 0.999, indicating that calculations of the total BSA and the burn area were more accurate using the BurnCalc technology. The reliability of the BurnCalc program was 99.9%. In experiment 3, only the BurnCalc method exhibited values of p > 0.05 (p = 0.774) and ICC = 0.999. CONCLUSIONS: BurnCalc technology produced stable, accurate readings, suggesting that BurnCalc could be regarded as a new standard clinical method

    General framework of quantum complementarity from a measurement-based perspective

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    One of the most remarkable features of quantum physics is that attributes of quantum objects, such as the wave-like and particle-like behaviors of single photons, can be complementary in the sense that they are equally real but cannot be observed simultaneously. Quantum measurements, serving as windows providing views into the abstract edifice of quantum theory, are basic tools for manifesting the intrinsic behaviors of quantum objects. However, quantitative formulation of complementarity that highlights its manifestations in sophisticated measurements remains elusive. Here we develop a general framework for demonstrating quantum complementarity in the form of information exclusion relations (IERs), which incorporates the wave-particle duality relations as particular examples. Moreover, we explore the applications of our theory in entanglement witnessing and elucidate that our IERs lead to an extended form of entropic uncertainty relations, providing intriguing insights into the connection between quantum complementarity and the preparation uncertainty.Comment: 13 pages (including 7 pages in the main text), 6 figure

    Motion of test particle in rotating boson star

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    Motion of a test particle plays an important role in understanding the properties of a spacetime. As a new type of the strong gravity system, boson stars could mimic black holes located at the center of galaxies. Studying the motion of a test particle in the spacetime of a rotating boson star will provide the astrophysical observable effects if a boson star is located at the center of a galaxy. In this paper, we investigate the timelike geodesic of a test particle in the background of a rotating boson star with angular number m=(1,2,3)m=(1, 2, 3). With the change of angular number and frequency, a rotating boson star will transform from the low rotating state to the highly relativistic rapidly rotating state, the corresponding Lense-Thirring effects will be more and more significant and it should be studied in detail. By solving the four-velocity of a test particle and integrating the geodesics, we investigate the bound orbits with a zero and nonzero angular momentum. We find that a test particle can stay more longer time in the central region of a boson star when the boson star becomes from low rotating state to highly relativistic rotating state. Such behaviors of the orbits are quite different from the orbits in a Kerr black hole, and the observable effects from these orbits will provide a rule to investigate the astrophysical compact objects in the Galactic center.Comment: comments are welcom
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