Next Generation High Throughput Satellite System

This paper aims at presenting an overview of the state-of-the-art in High Throughput Satellite (HTS) systems for Fixed Satellite Services (FSS) and High Density-FSS. Promising techniques and innovative strategies that can enhance system performance are reviewed and analyzed aiming to show what to expect for next generation ultra-high capacity satellite systems. Potential air interface evolutions, efficient frequency plans,feeder link dimensioning strategies and interference cancellation techniques are presented to show how Terabit/s satellite myth may turn into reality real soon

Distribution and Correlations of Non-High-Density Lipoprotein Cholesterol in Roma and Caucasian Children: The Slovak Lipid Community Study

Non-high-density lipoprotein (non-HDL) cholesterol [total cholesterol minus high-density lipoprotein (HDL) cholesterol] is considered a better predictor of coronary heart disease (CHD) risk than low-density lipoprotein (LDL) cholesterol. The Slovak Roma population have approximately 2.5-fold higher premature CHD mortality than the overall population. It is agreed that detection of dyslipidemia and prevention of atherosclerosis by controlling CHD risk factors should begin in childhood. However, only limited population-based data are available for non-HDL cholesterol in children. Hence the aim of the present cross-sectional study has been to determine population frequency data and correlations of non-HDL cholesterol in 788 Roma and Caucasian children (42% Roma, 51% male), aged 7–17, from Central Slovakia, as part of the Slovak Lipid Community Study. Roma children, compared to Caucasians, had higher serum levels of total cholesterol, LDL cholesterol and HDL cholesterol, were less physically active, smoked more, and had lower body mass index and blood pressure (all at p<0.05). Serum non-HDL cholesterol levels were similar in Roma and Caucasians (in mmol/L: 2.74 vs. 2.65, p=0.062) and similar too in boys and girls (2.66 vs. 2.73, p=0.092), but higher in the younger (7–11 yrs.) than in the older (12–17 yrs.) age group (2.77 vs. 2.62, p<0.001). Non-HDL cholesterol was negatively associated with age and cigarette smoking (r=–0.09 and –0.11 respectively, p<0.05), whereas general obesity as measured by body mass index, waist circumference and per capita income were positively correlated with non-HDL cholesterol (r=0.09–0.14, p<0.05). Intermediate or strong positive correlations were found with other lipid variables under study: triglycerides, total and LDL cholesterol and apoliporotein (Apo) B (r=0.43–0.93, p<0.001). No significant association was noted between non-HDL cholesterol and blood pressure, physical activity status, and HDL cholesterol and Apo AI. In a multivariate analysis: body mass index, age and cigarette smoking accounted for 3.3% of the variance in non- -HDL cholesterol. The non-HDL cholesterol cut-off points identified as corresponding to the recommended cut-off points of LDL cholesterol for CHD risk assessment and treatment of dyslipidemia in pediatric population were: acceptable <3.30, borderline 3.31–3.81 and high ł3.82 mmol/L. The prevalence of dyslipidemia according to the high non-HDL cholesterol value was 5.4% in Roma and 4.2% in Caucasian children (p=0.098). In conclusion, our results confirm no ethnic-, gender- or age-related differences in non-HDL cholesterol levels between Slovak Roma and Caucasian children. In both ethnic groups, overweight and obesity and also higher socio-economic status – but not cigarette smoking – are adversely associated with non-HDL cholesterol levels in childhood

Linear Precoding performance analysis in a Broadband satellite system with a 2-color dual-polarization reuse scheme

The potential of Joint Multiuser Processing in multi-beam satellite systems is assessed in this paper and proved to be a potential attractive alternative to current systems. The present contribution aims at investigating linear precoding techniques over an accurate multi-beam architecture modeling and system characterization. Power and precoder design problems are approached through well-known linear precoding techniques such as Zero Forcing (ZF) and Regularized-ZF. A dual-polarization 2-color reutilization scheme is considered in combination with precoding techniques. Results show a total throughput improvement of +22% achieved by ZF and +38% considering R-ZF, with respect to a conventional 4-color reuse scheme scenario

A Study of the Bulk Phase Transitions of the SU(2) Lattice Gauge Theory with Mixed Action

Using the finite size scaling theory, we re-examine the nature of the bulk phase transition in the fundamental-adjoint coupling plane of the SU(2) lattice gauge theory at $\beta_A = 1.25$ where previous finite size scaling investigations of the deconfinement phase transition showed it to be of first order for temporal lattices with four sites. Our simulations on $N^4$ lattices with N=6, 8, 10, 12 and 16 show an absence of a first order bulk phase transition. We find the discontinuity in the average plaquette to decrease approximately linearly with $N$. Correspondingly, the plaquette susceptibility grows a lot slower with the 4-volume of the lattice than expected from a first order bulk phase transition.Comment: LaTeX, 17 Pages; 7 Postscript Figures appende

The Tuning System for the HIE-ISOLDE High-Beta Quarter Wave Resonator

A new linac using superconducting quarter-wave resonators (QWR) is under construction at CERN in the framework of the HIE-ISOLDE project. The QWRs are made of niobium sputtered on a bulk copper substrate. The working frequency at 4.5 K is 101.28 MHz and they will provide 6 MV/m accelerating gradient on the beam axis with a total maximum power dissipation of 10 W on cavity walls. A tuning system is required in order to both minimize the forward power variation in beam operation and to compensate the unavoidable uncertainties in the frequency shift during the cool-down process. The tuning system has to fulfil a complex combination of RF, structural and thermal requirements. The paper presents the functional specifications and details the tuning system RF and mechanical design and simulations. The results of the tests performed on a prototype system are discussed and the industrialization strategy is presented in view of final production.Comment: 5 pages, The 16th International Conference on RF Superconductivity (SRF2013), Paris, France, Sep 23-27, 201

A mathematical model of metabolism and regulation provides a systems-level view of how Escherichia coli responds to oxygen

The efficient redesign of bacteria for biotechnological purposes, such as biofuel production, waste disposal or specific biocatalytic functions, requires a quantitative systems-level understanding of energy supply, carbon, and redox metabolism. The measurement of transcript levels, metabolite concentrations and metabolic fluxes per se gives an incomplete picture. An appreciation of the interdependencies between the different measurement values is essential for systems-level understanding. Mathematical modeling has the potential to provide a coherent and quantitative description of the interplay between gene expression, metabolite concentrations, and metabolic fluxes. Escherichia coli undergoes major adaptations in central metabolism when the availability of oxygen changes. Thus, an integrated description of the oxygen response provides a benchmark of our understanding of carbon, energy, and redox metabolism. We present the first comprehensive model of the central metabolism of E. coli that describes steady-state metabolism at different levels of oxygen availability. Variables of the model are metabolite concentrations, gene expression levels, transcription factor activities, metabolic fluxes, and biomass concentration. We analyze the model with respect to the production capabilities of central metabolism of E. coli. In particular, we predict how precursor and biomass concentration are affected by product formation

The Monte Carlo Program KoralW version 1.51 and The Concurrent Monte Carlo KoralW&YFSWW3 with All Background Graphs and First Order Corrections to W-Pair Production

The version 1.51 of the Monte Carlo (MC) program KoralW for all $e^+e^-\to f_1\bar f_2 f_3\bar f_4$ processes is presented. The most important change since the previous version 1.42 is the facility for writing MC events on the mass storage device and re-processing them later on. In the re-processing one may modify parameters of the Standard Model in order to fit them to experimental data. Another important new feature is a possibility of including complete ${\cal O}(\alpha)$ corrections to double-resonant W-pair component-processes in addition to all background (non-WW) graphs. The inclusion is done with the help of the YFSWW3 MC event generator for fully exclusive differential distributions (event-per-event). Technically, it is done in such a way that YFSWW3 runs concurrently with KoralW as a separate slave process, reading momenta of the MC event generated by KoralW and returning the correction weight to KoralW. KoralW introduces the ${\cal O}(\alpha)$ correction using this weight, and finishes processing the event (rejection due to total MC weight, hadronization, etc.). The communication between KoralW and YFSWW3 is done with the help of the FIFO facility of the UNIX/Linux operating system. This does not require any modifications of the FORTRAN source codes. The resulting Concurrent MC event generator KoralW&YFSWW3 looks from the user's point of view as a regular single MC event generator with all the standard features.Comment: 8 figures, 5 tables, submitted to Comput. Phys. Commu

Design, prototyping and testing of a compact superconducting double quarter wave crab cavity

A novel design of superconducting Crab Cavity was proposed and designed at Brookhaven National Laboratory. The new cavity shape is a Double Quarter Wave or DQWCC. After fabrication and surface treatments, the niobium proof-of-principle cavity was cryogenically tested in a vertical cryostat. The cavity is extremely compact yet has a low frequency of 400 MHz, an essential property for service for the Large Hadron Collider luminosity upgrade. The electromagnetic properties of the cavity are also well matched for this demanding task. The demonstrated deflecting voltage of 4.6 MV is well above the requirement for a crab cavity in the future High Luminosity LHC of 3.34 MV. In this paper we present the design, prototyping and test results of the DQWCC.Comment: to be published in Phys. Rev. ST Accel. Beam

Rabbit Knee Joint Biomechanics: Motion Analysis and Modeling of Forces during Hopping

Although the rabbit hindlimb has been commonly used as an experimental animal model for studies of osteoarthritis, bone growth and fracture healing, the in vivo biomechanics of the rabbit knee joint have not been quantified. The purpose of this study was to investigate the kinematic and kinetic patterns during hopping of the adult rabbit, and to develop a model to estimate the joint contact force distribution between the tibial plateaus. Force platform data and three-dimensional motion analysis using infrared markers mounted on intracortical bone pins were combined to calculate the knee and ankle joint intersegmental forces and moments. A statically determinate model was developed to predict muscle, ligament and tibiofemoral joint contact forces during the stance phase of hopping. Variations in hindlimb kinematics permitted the identification of two landing patterns, that could be distinguished by variations in the magnitude of the external knee abduction moment. During hopping, the prevalence of an external abduction moment led to the prediction of higher joint contact forces passing through the lateral compartment as compared to the medial compartment of the knee joint. These results represent critical data on the in vivo biomechanics of the rabbit knee joint, which allow for comparisons to both other experimental animal models and the human knee, and may provide further insight into the relationships between mechanical loading, osteoarthritis, bone growth, and fracture healing