Miracle-dz/UniFAR-FTUs huggingface dataset:
Is the Milky Way ringing? The hunt for high‐velocity streams

We perform numerical simulations of a stellar galactic disk with initial conditions chosen to represent an unrelaxed population which might have been left following a merger. Stars are unevenly distributed in radial action angle, though the disk is axisymmetric. The velocity distribution in the simulated Solar neighborhood exhibits waves traveling in the direction of positive v, where u,v are the radial and tangential velocity components. As the system relaxes and structure wraps in phase space, the features seen in the uv-plane move closer together. We show that these results can be obtained also by a semi-analytical method. We propose that this model could provide an explanation for the high velocity streams seen in the Solar neighborhood at approximate v in km/s, of -60 (HR 1614), -80 (Arifyanto and Fuchs 2006), -100 (Arcturus), and -160 (Klement et al. 2008). In addition, we predict four new features at v � -140, -120, 40 and 60 km/s. By matching the number and positions of the observed streams, we estimate that the Milky Way disk was strongly perturbed �1.9 Gyr ago. This event could have been associated with Galactic bar formation. Subject headings: stellar dynamics
A simple and effective backoff scheme for the IEEE 802.11 MAC protocol

Wireless Local Area Networks (WLANs) based on the IEEE 802.11 have been widely implemented in most commercial products available in the market. This paper proposes a simple and effective contention window-resetting scheme, named Double Increment Double Decrement (DIDD), to improve the performance of the contention based IEEE 802.11 Distributed Coordination Function (DCF). An alternative mathematical analysis for the proposed scheme is developed based on elementary conditional probability arguments rather than bi-dimensional Markov chains. Performance results are presented to identify the improvement of DIDD in terms of throughput and packet drop comparing to the Binary Exponential Backoff (BEB) utilized in the legacy IEEE 802.11 DCF.
Kinetics of the lower limb during two typical Tai Chi movements in the elderly

ABSTRACT Tai Chi (TC) is a recommended exercise for elderly people; however, its loading on the joints of the lower limbs is unknown. This study examined the 3D kinetics of the lower limbs during two typical TC movements and walking in the elderly. Fifteen experienced TC practitioners participated. Ground reaction forces, joint moments and time-to-peak joint moment generation were analysed. Compared with walking, both TC movements generated significantly (1) smaller peak ground reaction forces in all directions, except the anterior; (2) larger hip extension, adduction and internal rotational moments, knee adduction/abduction and internal rotation moments and eversion/inversion and external/internal moments of ankle–foot; and (3) longer peak moment generation time for hip extension, adduction and internal rotation, knee extension and ankle dorsiflexion and inversion. The TC loading patterns are consistent with the mechanical behaviour of biological tissues, which could help to strengthen the lower extremities and prevent falls in the elderly.
Phonon contribution to quasiparticle lifetimes in Cu measured by angle-resolved photoemission.

The line shape of the photoelectron spectrum emitted from the {ital sp}-derived surface state at {bar {Gamma}} on Cu(111) is investigated. The line shape is Lorentzian, and the temperature dependence of the width is linear, varying from 30 meV at 30 K to 75 meV at 625 K. Less than 5-meV variation with binding energy is observed. The temperature dependence is explained as the phonon contribution to the inverse hole lifetime, predicted to be 2{pi}{lambda}{ital k}{sub {ital b}}{ital T} allowing the determination that the electron-phonon mass enhancement parameter {lambda}=0.14{plus_minus}0.02 for this surface state at {bar {Gamma}}. This is compared to {lambda}=0.15 reported as an average over the bulk Fermi surface.
Age-Dependent Prevalence of Nasopharyngeal Carriage of Streptococcus pneumoniae before Conjugate Vaccine Introduction: A Prediction Model Based on a Meta-Analysis

Introduction Data on the prevalence of nasopharyngeal carriage of S.pneumoniae in all age groups are important to help predict the impact of introducing pneumococcal conjugate vaccines (PCV) into routine infant immunization, given the important indirect effect of the vaccine. Yet most carriage studies are limited to children under five years of age. We here explore the association between carriage prevalence and serotype distribution in children aged ≥5 years and in adults compared to children. Methods We conducted a systematic review of studies providing carriage estimates across age groups in healthy populations not previously exposed to PCV, using MEDLINE and Embase. We used Bayesian linear meta-regression models to predict the overall carriage prevalence as well as the prevalence and distribution of vaccine and nonvaccine type (VT and NVT) serotypes in older age groups as a function of that in <5 y olds. Results Twenty-nine studies compromising of 20,391 individuals were included in the analysis. In all studies nasopharyngeal carriage decreased with increasing age. We found a strong positive linear association between the carriage prevalence in pre-school childen (<5 y) and both that in school aged children (5–17 y olds) and in adults. The proportion of VT serotypes isolated from carriers was consistently lower in older age groups and on average about 73% that of children <5 y among 5–17 y olds and adults respectively. We provide a prediction model to infer the carriage prevalence and serotype distribution in 5–17 y olds and adults as a function of that in children <5 years of age. Conclusion Such predictions are helpful for assessing the potential population-wide effects of vaccination programmes, e.g. via transmission models, and thus assist in the design of future pneumococcal conjugate vaccination strategies.
Modelling age‐dependent force of infection from prevalence data using fractional polynomials

The force of infection is one of the primary epidemiological parameters of infectious diseases. For many infectious diseases it is assumed that the force of infection is age‐dependent. Although the force of infection can be estimated directly from a follow up study, it is much more common to have cross‐sectional seroprevalence data from which the prevalence and the force of infection can be estimated. In this paper, we propose to model the force of infection within the framework of fractional polynomials. We discuss several parametric examples from the literature and show that all of these examples can be expressed as special cases of fractional polynomial models. We illustrate the method on five seroprevalence samples, two of Hepatitis A, and one of Rubella, Mumps and Varicella. Copyright © 2005 John Wiley & Sons, Ltd.
Myosin Isoenzymes of Vascular Smooth and Cardiac Muscle in the Spontaneously Hypertensive and Normotensive Male and Female Rat: A Comparative Study

Cardiac hypertrophy in hypertensive subjects, its biochemical markers, and functional consequences are of great clinical importance but still unclear. We observed a shift of the ventricular isomyosin of adult spontaneously hypertensive (H) rats of both sexes to the V3 form and a decreased myofibrillar ATPase activity in the H animals when compared to normotensive (N) controls. Compared to the male H rats, age-matched female H animals revealed a lower blood pressure, the same or even an elevated magnitude of cardiac hypertrophy, a different ventricular isomyosin pattern, and a higher myofibrillar ATPase activity. In female H rats the V1 and V3 isomyosins were equally distributed (35% V1 and 35% V3), but in male H animals the V3 was predominant (24% V1 and 45% V3). The Ca2+: -regulated Mg2+:-dependent myofibrillar ATPase of the rat ventricle correlated positively with the amount of V1 when measured at pCa 5 (maximum activation). At submaximum Ca2+-concentrations (pCa 6.9–:5.9) the myofibrillar ATPase activities were not changed with the proportion of V1. The cooperativity of the Ca2+:-activation of the myofibrillar ATPase increased with increasing amount of V1 (Hill-coefficient 3.7 with 100% V1) and decreased with increased proportion of V3 (Hill-coefficient 1.3 at 45% V3). Two myosin isoenzymes were detected in the aorta of rats, a slow migrating (S2) and a fast migrating (S1) form having both a higher mobility than the ventricular isomyosins. Only one band was observed in the portal vein, which revealed the same mobility as S2. Hypertension did not change the appearance of these vascular smooth muscle isomyosins neither in male nor in female animals.
Performance Analysis of Wireless Networks With Directional Antennas

In this paper, we consider wireless networks with directional antennas using slotted ALOHA medium access control. The channel model incorporates the effects of propagation loss and shadowing with Rayleigh fading. By deriving the cumulative distribution function of the signal-to-interference-and-noise ratio (SINR) of a certain link in the network, the outage probability of the link is analyzed. In particular, the analysis works for the arbitrary beam patterns of the directional antennas used in the networks. Moreover, we propose a new parameter, i.e., the array interference factor, which can characterize the average performance of an arbitrary beam pattern in random wireless networks. This provides an efficient way for designers to evaluate the system performance under different beam patterns. The network throughput and the transport capacity of a random wireless network with directional antennas are also analyzed. It is shown that the network transport capacity is of the same order as the square root of the node density, which conforms with the well-known capacity of wireless networks. The analysis is useful for designers to optimize the system performance of wireless networks with directional antennas.
Thermomechanical postbuckling of geometrically imperfect anisotropic flat and doubly curved sandwich panels

Sandwich structures constitute basic components of advanced supersonic/hypersonic flight and launch vehicles. These advanced flight vehicles operate in hostile environments consisting of high temperature, moisture, and pressure fields. As a result, these structures are exposed to large lateral pressures, large compressive edge loads, and high temperature gradients which can create large stresses and strains within the structure and can produce the instability of the structure. This creates the need for a better understanding of the behavior of these structures under these complex loading conditions. Moreover, a better understanding of the load carrying capacity of sandwich structures constitutes an essential step towards a more rational design and exploitation of these constructions. In order to address these issues, a comprehensive geometrically non-linear theory of doubly curved sandwich structures constructed of anisotropic laminated face sheets with an orthotropic core under various loadings for simply supported edge conditions is developed. The effects of the radii of curvature, initial geometric imperfections, pressure, uniaxial compressive edge loads, biaxial edge loading consisting of compressive/tensile edge loads, and thermal loads will be analyzed. The effect of the structural tailoring of the facesheets upon the load carrying capacity of the structure under these various loading conditions are analyzed. In addition, the movability/immovability of the unloaded edges and the end-shortening are examined. To pursue this study, two different formulations of the theory are developed. One of these formulations is referred to as the mixed formulation, While the second formulation is referred to as the displacement formulation. Several results are presented encompassing buckling, postbuckling, and stress/strain analysis in conjunction with the application of the structural tailoring technique. The great effects of this technique are explored. Moreover, comparisons with the available theoretical and experimental results are presented and good agreements are reported.
Massive MIMO With Max-Min Power Control in Line-of-Sight Propagation Environment

Massive MIMO relies on the asymptotic orthogonality of channel vectors to different users. For <inline-formula> <tex-math notation="LaTeX">$M$ </tex-math></inline-formula> service antennas, the expected correlation between a pair of channel vectors under line-of-sight (LoS) conditions decreases at least as fast as <inline-formula> <tex-math notation="LaTeX">$\log (M)/M$ </tex-math></inline-formula>, while in independent and identically distributed (iid) Rayleigh fading, it decreases much slower at <inline-formula> <tex-math notation="LaTeX">$1/\sqrt {M}$ </tex-math></inline-formula>, but the variance is higher under LoS. This signifies that typically channel vectors are more nearly orthogonal under LoS, but with a non-negligible probability, they can have an anomalously large correlation. A single-cell analysis discloses that Massive MIMO with max-min power control performs comparably under LoS and iid Rayleigh, when a simple algorithm is applied under LoS to drop a small number of high-correlation users from service.
Treatment of solid tumors by interstitial release of recoiling short-lived alpha emitters

A new method utilizing alpha particles to treat solid tumors is presented. Tumors are treated with interstitial radioactive sources which continually release short-lived alpha emitting atoms from their surface. The atoms disperse inside the tumor, delivering a high dose through their alpha decays. We implement this scheme using thin wire sources impregnated with 224Ra, which release by recoil 220Rn, 216Po and 212Pb atoms. This work aims to demonstrate the feasibility of our method by measuring the activity patterns of the released radionuclides in experimental tumors. Sources carrying 224Ra activities in the range 10–130 kBq were used in experiments on murine squamous cell carcinoma tumors. These included gamma spectroscopy of the dissected tumors and major organs, Fuji-plate autoradiography of histological tumor sections and tissue damage detection by Hematoxylin-Eosin staining. The measurements focused on 212Pb and 212Bi. The 220Rn/216Po distribution was treated theoretically using a simple diffusion model. A simplified scheme was used to convert measured 212Pb activities to absorbed dose estimates. Both physical and histological measurements confirmed the formation of a 5–7 mm diameter necrotic region receiving a therapeutic alpha-particle dose around the source. The necrotic regions shape closely corresponded to the measured activity patterns. 212Pb was found to leave the tumor through the blood at a rate which decreased with tumor mass. Our results suggest that the proposed method, termed DART (diffusing alpha-emitters radiation therapy), may potentially be useful for the treatment of human patients.
Alloying From Screen-Printed Aluminum Pastes Containing Boron Additives

We present a detailed study on alloying from screen-printed aluminum pastes containing boron additives (Al-B pastes) to further enhance the efficiency of p- and n-type silicon solar cells with an Al-alloyed back-surface field and rear emitter, respectively. Due to the high B solubility in Si, the additional incorporation of B atoms as acceptors into the Al-alloyed p+ region-referred to as Al-B codoping of Si-provides improved shielding of electrons from the recombination-active surface. Thus, alloying from Al-B pastes allows for significantly thinner p + regions and leads to a considerable reduction of the p + saturation current densities. By comparing surface-passivated p+ regions alloyed from Al-B pastes or conventional Al pastes with each other, we show that a highly recombination-active defect limits the minority carrier lifetime in these p+ regions. We demonstrate that the acceptor concentration profiles of the p+ regions can easily be modified by adding different amounts of aluminum diboride or boron trioxide as B sources to the Al pastes.
Performance analysis of closed-form, ESPRIT based 2-D angle estimator for rectangular arrays

The 2D DFT beamspace ESPRIT is an algorithm for use in conjunction with uniform rectangular arrays (URAs) that provides automatically paired azimuth and elevation angle estimates of incident signals via a closed-form procedure. We investigate the statistical performance of 2D DFT beamspace ESPRIT. Expressions for the 2D DFT beamspace ESPRIT estimator variances are obtained. Samples variances of the azimuth and elevation angle estimates obtained through Monte Carlo simulations are shown to be in close agreement with theoretically predicted variances.
The potentiation of zinc toxicity by soil moisture in a boreal forest ecosystem

Northern boreal forests often experience forest dieback as a result of metal ore mining and smelting. The common solution is to lime the soil, which increases pH, reducing metal toxicity and encouraging recovery. In certain situations, however, such as in Flin Flon, Manitoba, Canada, liming has yielded only moderate benefits, with some locations responding well to liming and other locations not at all. In an effort to increase the effectiveness of the ecorestoration strategy, the authors investigated if these differences in liming responsiveness were linked to differences in toxicity. Toxicity of metal‐impacted Flin Flon soils on the oribatid mite Oppia nitens and the collembolan Folsomia candida was assessed, with a view toward identifying the metal of concern in the area. The effects of moisture content on metal sorption, uptake, and toxicity to the invertebrates were also investigated. Toxicity tests with the invertebrates were conducted using either Flin Flon soils or artificial soils with moisture content adjusted to 30%, 45%, 60%, or 75% of the maximum water‐holding capacity of the soil samples. The Relative to Cd Toxicity Model identified Zn as the metal of concern in the area, and this was confirmed using validation tests with field contaminated soils. Furthermore, increasing the moisture content in soils increased the amount of mobile Zn available for uptake with the ion exchange resin. Survival and reproduction of both invertebrates were reduced under Zn exposure as moisture level increased. Thus, moisture‐collecting landforms, which are often also associated with high Zn concentrations at Flin Flon, have, as a result, higher Zn toxicity to the soil ecosystem because of increases in soil moisture. Environ Toxicol Chem 2015;34:600–607. © 2014 SETAC
A Residue-to-Binary Converter for a New Five-Moduli Set

The efficiency of the residue number system (RNS) depends not only on the residue-to-binary converters but also the operand sizes and the modulus in each residue channel. Due to their special number theoretic properties, RNS with a moduli set consisting of moduli in the form of 2 <sup>n</sup>plusmn1 is more attractive than those with other forms of moduli. In this paper, a new five-moduli set RNS {2<sup>n</sup>-1,2<sup>n</sup>,2<sup>n</sup>+1,2<sup>n</sup>+1-1,2 <sup>n-1</sup>-1} for even n is proposed. The new moduli set has a dynamic range of (5n-1) bits. It incorporates two additional moduli to the celebrated three-moduli set, {2<sup>n</sup>-1,2<sup>n</sup>,2<sup>n </sup>+1} with VLSI efficient implementations for both the binary-to-residue conversion and the residue arithmetic units. This extension increases the parallelism and reduces the size of each residue channel for a given dynamic range. The proposed residue-to-binary converter relies on the properties of an efficient residue-to-binary conversion algorithm for {2<sup>n</sup>-1,2<sup>n</sup>,2<sup>n</sup>+1,2<sup>n</sup>+1-1} and the mixed-radix conversion (MRC) technique for the two-moduli set RNS. The hardware implementation of the proposed residue-to-binary converter employs adders as the primitive operators. Besides, it can be easily pipelined to attain a high throughput rate
Canary finches (Serinus canaria) as an avian infection model for Lyme borreliosis.

To investigate if passerine birds can be used as an avian model for Lyme borreliosis, the Borrelia burgdorferi sensu stricto strain Sh2-82 was inoculated subcutaneously on Canary finches (Serinus canaria). Spirochaetes could be detected in the blood by direct microscopy and an immunofluorescence assay (IFA) up to 2 weeks after the inoculation. DNA amplification (PCR) revealed B. burgdorferi DNA in the serum for up to 3 weeks, in the faeces up to 4 weeks, and from several internal organs at autopsy 3 months after the inoculation. Of particular interest was the finding of B. burgdorferi DNA in the liver of all birds at the end of the experiment, indicating a persistent infection. Four weeks after the primary infection, all infected birds showed an increase in anti Borrelia IgG antibodies and after 6 weeks all birds had seroconverted. Except for a brief episode of diarrhoea, none of the birds showed any signs of disease. This study shows that passerine birds experience short-term spirochaetemia after infection with B. burgdorferi, but show few clinical symptoms. This suggests that, although these birds can act as reservoirs of B. burgdorferi s.s. , they may be of less importance as long lasting amplifiers for this pathogen.
Chain Replication for Supporting High Throughput and Availability

Chain replication is a new approach to coordinating clusters of fail-stop storage servers. The approach is intended for supporting large-scale storage services that exhibit high throughput and availability without sacrificing strong consistency guarantees. Besides outlining the chain replication protocols themselves, simulation experiments explore the performance characteristics of a prototype implementation. Throughput, availability, and several object-placement strategies (including schemes based on distributed hash table routing) are discussed.
Multi-layered image representation: application to image compression

We describe a new multi-layered representation technique for images. An image is encoded as the superposition of one main approximation, and a sequence of residuals. The strength of the multi-layered method comes from the fact that we use different bases to encode the main approximation and the residuals. The different bases complement each others: some of the basis functions will give reasonable account of the large trend of the data, while others will catch the local transients, or the oscillatory patterns. By selecting different bases, we allow different features to be discovered in the image.