2,308 research outputs found
On the speed of convergence to stationarity of the Erlang loss system
We consider the Erlang loss system, characterized by servers, Poisson arrivals and exponential service times, and allow the arrival rate to be a function of We discuss representations and bounds for the rate of convergence to stationarity of the number of customers in the system, and display some bounds for the total variation distance between the time-dependent and stationary distributions. We also pay attention to time-dependent rates
Analytic Solution for the Ground State Energy of the Extensive Many-Body Problem
A closed form expression for the ground state energy density of the general
extensive many-body problem is given in terms of the Lanczos tri-diagonal form
of the Hamiltonian. Given the general expressions of the diagonal and
off-diagonal elements of the Hamiltonian Lanczos matrix, and
, asymptotic forms and can be defined in
terms of a new parameter ( is the Lanczos iteration and is
the size of the system). By application of theorems on the zeros of orthogonal
polynomials we find the ground-state energy density in the bulk limit to be
given in general by .Comment: 10 pages REVTex3.0, 3 PS figure
Preparing DARIAH
In this paper, a preparatory project for an integrated European research infrastructure in the humanities is presented. This project, Preparing for the construction of the Digital Research Infrastructure for the Arts and Humanities - or Preparing DARIAH for short, is part of the ESFRI e-infrastructures programme and supports the emergence of a new collaborative framework in which researchers are able to maximise the impact of their work on the international stage and aims at providing the foundations for the timely construction of the infrastructure requisite for the arts, humanities and cultural heritage communities in the digital age. DARIAH uses an interdisciplinary approach and involves tackling a number of interrelated issues such as strategic, organisational, financial, technical and conceptual in order to facilitate long-term access to and use of all European humanities and cultural heritage information for the purposes of enhancing and expanding research, thereby increasing our knowledge and understanding of our histories, heritage, languages and cultures. The DARIAH network will act as a place where the incubation of new ideas and ways of working can be facilitated and developed, and then transitioned into established organisations thus ensuring long-term sustainability and stability and the integration of these methods and techniques into everyday research practice. DARIAH will support research practitioners at all stages in the research process, and at differing levels of sophistication, from beginners through to those employing advanced techniques and methodologies
Nature of the constant factor in the relation between radial breathing mode frequency and tube diameter for single-wall carbon nanotubes
Resonance Raman scattering is used to determine the radial breathing mode (RBM) frequency (ωRBM) dependence on tube diameter (dt) for single-wall carbon nanotubes (SWNTs). We establish experimentally the ωRBM=227.0/dt as the fundamental relation for pristine SWNTs. All the other RBM values found in the literature can be explained by an upshift in frequency due mostly to van der Waals interaction between SWNTs and environment
The occurrence of Guillain-Barré syndrome within families (multiple letters)
We thank Drs. Korn-Lubetzki and Steiner for their interest in our article. They concluded that the 17p12 deletion responsible for HNPP was also present in a family in which three members had an IDP. Two members fulfilled the criteria for CIDP and the other for AIDP.This finding may indicate that CIDP and this deletion may also be present in our recently reported Dutch families in which two or more members had GBS. [...
The occurrence of Guillain-Barré syndrome within families (multiple letters)
We thank Drs. Korn-Lubetzki and Steiner for their interest in our article. They concluded that the 17p12 deletion responsible for HNPP was also present in a family in which three members had an IDP. Two members fulfilled the criteria for CIDP and the other for AIDP.This finding may indicate that CIDP and this deletion may also be present in our recently reported Dutch families in which two or more members had GBS. [...
Effect of a Fundamental Motor Skills Intervention on Fundamental Motor Skill and Physical Activity in a Preschool Setting: A Cluster Randomized Controlled Trial
Purpose: To determine the effect of a 12-week fundamental motor skill (FMS) program on FMS and physical activity (PA) on preschool-aged children. Method: A cluster randomized controlled trial. The intervention (PhysicaL ActivitY and Fundamental Motor Skills in Pre-schoolers [PLAYFun] Program) was a 12-week games-based program, delivered directly to the children in childcare centers by exercise physiologists. Children in the control arm received the usual preschool curriculum. Outcomes included FMS competence (Test of Gross Motor Development-2) and PA (accelerometer) assessed at baseline, 12 weeks, and 24 weeks (12-wk postintervention). Results: Fifty children (mean age = 4.0 [0.6] y; 54% male) were recruited from 4 childcare centers. Two centers were randomized to PLAYFun and 2 centers were randomized to the waitlist control group. Children attended on average 2.0 (1.0) 40-minute sessions per week. The PLAYFun participants demonstrated significant increases in object control (P < .001) and total FMS (P = .010) competence at week 12, compared with controls in a group × time interaction. Girls, but not boys, in PLAYFun significantly increased moderate to vigorous PA after the intervention (P = .004). These increases were not maintained 12-week postcompletion of PLAYFun. Conclusions: The PLAYFun Program is effective at improving FMS competence in boys and girls and increasing PA in girls. However, improvements are not maintained when opportunities to practice are not sustained
Impact of host DNA and sequencing depth on the taxonomic resolution of whole metagenome sequencing for microbiome analysis
The amount of host DNA poses a major challenge to metagenome analysis. However, there is no guidance on the levels of host DNA, nor on the depth of sequencing needed to acquire meaningful information from whole metagenome sequencing (WMS). Here, we evaluated the impact of a wide range of amounts of host DNA and sequencing depths on microbiome taxonomic profiling using WMS. Synthetic samples with increasing levels of host DNA were created by spiking DNA of a mock bacterial community, with DNA from a mouse-derived cell line. Taxonomic analysis revealed that increasing proportions of host DNA led to decreased sensitivity in detecting very low and low abundant species. Reduction of sequencing depth had major impact on the sensitivity of WMS for profiling samples with 90% host DNA, increasing the number of undetected species. Finally, analysis of simulated datasets with fixed depth of 10 million reads confirmed that microbiome profiling becomes more inaccurate as the level of host DNA increases in a sample. In conclusion, samples with high amounts of host DNA coupled with reduced sequencing depths, decrease WMS coverage for characterization of the microbiome. This study highlights the importance of carefully considering these aspects in the design of WMS experiments to maximize microbiome analyses.This work was supported by European Regional Development Funds (ERDF) funds through the COMPETE 2020 – Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by FCT – Fundação para a Ciência e a Tecnologia (POCI-01-0145-FEDER-032532). JP-M and IP-R have fellowships from FCT (PD/BD/114014/2015 and SFRH/BD/110803/2015, respectively) through Programa Operacional Capital Humano (POCH) and the European Social Fund. JP-M’s have fellowship from the framework of FCT’s Ph.D. Program Biotech Health (Ref. PD/0016/2012)
Helicobacter Genotyping and Detection in Peroperative Lavage Fluid in Patients with Perforated Peptic Ulcer
Introduction and Objectives Certain Helicobacter pylori genotypes are associated with peptic ulcer disease; however, little is known about associations between the H. pylori genotype and perforated peptic ulcer (PPU). The primary aim of this study was to evaluate which genotypes are present in patients with PPU and which genotype is dominant in this population. The secondary aim was to study the possibility of determining the H. pylori status in a way other than by biopsy.
Materials and Methods Serum samples, gastric tissue biopsies, lavage fluid, and fluid from the nasogastric tube were collec
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