2,803 research outputs found

    Genetic diversity and historical demography of kuruma shrimp (Penaeus japonicus) species complex off China based on mitochondrial DNA analysis

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    Two varieties (I and II) of kuruma shrimp (Penaeus japonicus) were found in the north of South China Sea (SCS) and Taiwan Strait (TS). To estimate the demographic history and genetic diversity of this species complex off China, 141 individuals were collected from the East China Sea (ECS), TS and SCS and 27 variety 2 specimens from SCS were also sampled for comparison. Sequence analyses on fragments of 454-bp at 5’ end of mitochondrial DNA control region were conducted. Neighbor-joining tree and network of all populations yielded two clades; one included variety I individuals, the other comprised variety II. The variety II could also be found in ECS. The haplotype diversity (h) for variety I was high for all populations (99.9%), with values from 99.3% (ECS) to 1 (SCS). Nucleotide diversity (ð) for variety I was low for all populations (0.0321), with values from 0.0285 (TS) to 0.0361 (ECS). The h and ð for variety II were 1 and 0.0446, respectively. Analyses of molecular variance and FST revealed no significant genetic structure for variety I populations. Neutrality tests and mismatch distribution analyses suggested a late Pleistocene population expansion for both variety I (62,132 to 86,605 years ago) and variety II (94,464 to 146,655 years ago) of kuruma shrimp off China.Key words: Mitochondrial DNA, Penaeus japonicus, historical demography, control region

    Appropriate antivenom doses for six types of envenomations caused by snakes in taiwan

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    Six of the 15 species of venomous snakes found in Taiwan are responsible for most of the clinically significant envenomations in the country. These species are: Trimeresurus mucrosquamatus, Trimeresurus stejnegeri, Naja atra, Bungarus multicinctus, Deinagkistrodon acutus and Daboia russelii siamensis, which together can be subdivided into three groups based on their venom effects. Primary treatment consists of rapid administration of appropriate antivenoms. The present study aimed to identify a proper dose of antivenom for each snake group as well as to describe hemorrhagic, neurotoxic, and mixed effects of their venoms. A retrospective chart review identified 72 snakebite cases referred to an emergency department. Data on epidemiology, examination findings, snake identification, treatment, antivenom dose and complications were collected. After excluding 14 patients, data from 58 victims were analyzed. Most studied cases were male (86%). Significantly higher doses of antivenom were administered against neurotoxic envenomations (mean dose: three vials) compared with the other two (p < 0.05). Moreover, patients affected by neurotoxic bites were more likely to develop blurred vision and other complications (p < 0.05). Multivariate logistic regression analysis indicated that neurotoxic envenomation was a risk factor for complications (OR: 8.84, 95% CI: 1.06-73.73). Neurotoxic envenomations and complication occurrence were positively correlated with antivenom dosage. In conclusion, patients affected by neurotoxic envenomations received higher doses of antivenom than others whereas incidence of complications was associated with higher antivenom doses

    Theory of impedance networks: The two-point impedance and LC resonances

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    We present a formulation of the determination of the impedance between any two nodes in an impedance network. An impedance network is described by its Laplacian matrix L which has generally complex matrix elements. We show that by solving the equation L u_a = lambda_a u_a^* with orthonormal vectors u_a, the effective impedance between nodes p and q of the network is Z = Sum_a [u_{a,p} - u_{a,q}]^2/lambda_a where the summation is over all lambda_a not identically equal to zero and u_{a,p} is the p-th component of u_a. For networks consisting of inductances (L) and capacitances (C), the formulation leads to the occurrence of resonances at frequencies associated with the vanishing of lambda_a. This curious result suggests the possibility of practical applications to resonant circuits. Our formulation is illustrated by explicit examples.Comment: 21 pages, 3 figures; v4: typesetting corrected; v5: Eq. (63) correcte

    Seeking the invisible: I-131 NP-59 SPECT/CT for primary hyperaldosteronism

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    Influence of realistic parameters on state-of-the-art LWFA experiments

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    We examine the influence of non-ideal plasma-density and non-Gaussian transverse laser-intensity profiles in the laser wakefield accelerator analytically and numerically. We find that the characteristic amplitude and scale length of longitudinal density fluctuations impacts on the final energies achieved by electron bunches. Conditions that minimize the role of the longitudinal plasma density fluctuations are found. The influence of higher order Laguerre-Gaussian laser pulses is also investigated. We find that higher order laser modes typically lead to lower energy gains. Certain combinations of higher order modes may, however, lead to higher electron energy gains.Comment: 16 pages, 6 figures; Accepted for publication in Plasma Physics and Controlled Fusio

    Relationship Between Cerebral Blood Flow and Blood Pressure in Long-Term Heart Transplant Recipients

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    Heart transplant recipients are at an increased risk for cerebral hemorrhage and ischemic stroke, yet the exact mechanism for this derangement remains unclear. We hypothesized that alterations in cerebrovascular regulation is principally involved. To test this hypothesis, we studied cerebral pressure-flow dynamics in 8 clinically stable male heart transplant recipients (62 ± 8 years of age and 9 ± 7 years post-transplant, mean + SD), 9 male age-matched controls (63 ± 8 years) and 10 male donor controls (27 ± 5 years). To increase blood pressure variability and improve assessment of the pressure-flow dynamics, subjects performed squat-stand maneuvers at 0.05 and 0.10 Hz. Beat-to-beat blood pressure, middle cerebral artery velocity, and end-tidal carbon dioxide were continuously measured during five minutes of seated rest, and throughout the squat-stand maneuvers. Cardiac baroreceptor sensitivity gain and cerebral pressure-flow responses were assessed with linear transfer function analysis. Heart transplant recipients had reductions in R-R interval power and baroreceptor sensitivity low frequency gain (P<0.01) compared to both control groups; however, these changes were unrelated to transfer function metrics. Thus, in contrast to our hypothesis, the increased risk of cerebrovascular complication after heart transplantation does not appear to be related to alterations in cerebral pressure-flow dynamics. Future research is therefore warranted

    Pumping Speed Measurement and Analysis for the Turbo Booster Pump

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    This study applies testing apparatus and a computational approach to examine a newly designed spiral-grooved turbo booster pump (TBP), which has both volume type and momentum transfer type vacuum pump functions, and is capable of operating at optimum discharge under pressures from approximately 1000 Pa to a high vacuum. Transitional flow pumping speed is increased by a well-designed connecting element. Pumping performance is predicted and examined via two computational approaches, namely the computational fluid dynamics (CFD) method and the direct simulation Monte Carlo (DSMC) method. In CFD analysis, comparisons of measured and calculated inlet pressure in the slip and continuum flow demonstrate the accuracy of the calculation. Meanwhile, in transition flow, the continuum model of CFD is unsuitable for calculating such rarefied gas. The pumping characteristics for a full 3D model on a rotating frame in transition and molecular regimes thus are simulated using the DSMC method and then confirmed experimentally. However, when the Knudsen number is in the range 0.5 < Kn < 0.1, neither CFD computation nor DSMC simulation is suitable for analyzing the pumping speed of the turbo booster pump. In this situation, the experimental approach is the most appropriate and effective method for analyzing pumping speed. Moreover, the developed pump is tested using assessment systems constructed according to ISO and JVIS-005 standards, respectively. Comparisons are also made with other turbo pumps. The compared results show that the turbo booster pump presented here has good foreline performance

    Spanning Trees on Graphs and Lattices in d Dimensions

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    The problem of enumerating spanning trees on graphs and lattices is considered. We obtain bounds on the number of spanning trees NSTN_{ST} and establish inequalities relating the numbers of spanning trees of different graphs or lattices. A general formulation is presented for the enumeration of spanning trees on lattices in d2d\geq 2 dimensions, and is applied to the hypercubic, body-centered cubic, face-centered cubic, and specific planar lattices including the kagom\'e, diced, 4-8-8 (bathroom-tile), Union Jack, and 3-12-12 lattices. This leads to closed-form expressions for NSTN_{ST} for these lattices of finite sizes. We prove a theorem concerning the classes of graphs and lattices L{\cal L} with the property that NSTexp(nzL)N_{ST} \sim \exp(nz_{\cal L}) as the number of vertices nn \to \infty, where zLz_{\cal L} is a finite nonzero constant. This includes the bulk limit of lattices in any spatial dimension, and also sections of lattices whose lengths in some dimensions go to infinity while others are finite. We evaluate zLz_{\cal L} exactly for the lattices we considered, and discuss the dependence of zLz_{\cal L} on d and the lattice coordination number. We also establish a relation connecting zLz_{\cal L} to the free energy of the critical Ising model for planar lattices L{\cal L}.Comment: 28 pages, latex, 1 postscript figure, J. Phys. A, in pres
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