Centrifuge Rotor Models: A Comparison of the Euler-Lagrange and the Bond Graph Modeling Approach

A viewgraph presentation on centrifuge rotor models with a comparison using Euler-Lagrange and bond graph methods is shown. The topics include: 1) Objectives; 2) MOdeling Approach Comparisons; 3) Model Structures; and 4) Application

International Space Station Centrifuge Rotor Models A Comparison of the Euler-Lagrange and the Bond Graph Modeling Approach

The assembly and operation of the International Space Station (ISS) require extensive testing and engineering analysis to verify that the Space Station system of systems would work together without any adverse interactions. Since the dynamic behavior of an entire Space Station cannot be tested on earth, math models of the Space Station structures and mechanical systems have to be built and integrated in computer simulations and analysis tools to analyze and predict what will happen in space. The ISS Centrifuge Rotor (CR) is one of many mechanical systems that need to be modeled and analyzed to verify the ISS integrated system performance on-orbit. This study investigates using Bond Graph modeling techniques as quick and simplified ways to generate models of the ISS Centrifuge Rotor. This paper outlines the steps used to generate simple and more complex models of the CR using Bond Graph Computer Aided Modeling Program with Graphical Input (CAMP-G). Comparisons of the Bond Graph CR models with those derived from Euler-Lagrange equations in MATLAB and those developed using multibody dynamic simulation at the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) are presented to demonstrate the usefulness of the Bond Graph modeling approach for aeronautics and space applications

All-optical 2R regeneration with a vertical microcavity based saturable absorber

International audienceThis paper gives an overview of recent demonstrations of optical 2R regeneration achieved by vertical microcavity mirror based multiple-quantum-well Saturable Absorber (SA). The potential of the device to perform WDM regeneration is firstly demonstrated through the first pigtailed saturable absorber chip implemented with 8 independent fibres using a cost effective coupling technique. The cascadability and wavelength tunability assessment of this module associated to a power limiter fibre-based function has been experimentally demonstrated at 42.6 Gbit/s. Because this method of power limiting is not a suitable solution for all-optical multichannel 2R regeneration, a new SA structure allowing a power limiting function was proposed. We describe and characterize such a structure in this paper. This new SA opens the door to a complete passive all-optical 2R regeneration relying upon a single technology, as shown in this paper through the use of two SA: SA.0 for extinction ratio enhancement and SA.1 for power level equalization allowing receiver sensitivity (up to 3.5 dB) and Q factor (up to 1.4 dB) improvement for a RZ signal at 42.6 Gbit/s. The limitation of SA.1 when the regenerator must be cascaded a large number of times is also described, leading to the observation that SA.1 should be more suitable for phase encoded formats which are more spectrally efficient than OOK formats. A SA.1 used as a phase-preserving amplitude regenerator in a 42.6 Gbit/s RZ-DPSK transmission system is therefore assessed. A fibre launched power margin of 2 dB and a receiver sensitivity improvement of 5.5 dB are obtained. Finally, we use, for the first time an SA.1 as a phase-preserving amplitude regenerator of RZ DQPSK signals. The regenerator is assessed in a recirculating loop at 28 Gbaud. The system tolerance to nonlinear phase noise is enhanced by 3 dB and the distance improvement factor was 1.3 for a BER=10-4

Synthetic RNA modules for fine-tuning gene expression levels in yeast by modulating RNase III activity

The design of synthetic gene networks requires an extensive genetic toolbox to control the activities and levels of protein components to achieve desired cellular functions. Recently, a novel class of RNA-based control modules, which act through post-transcriptional processing of transcripts by directed RNase III (Rnt1p) cleavage, were shown to provide predictable control over gene expression and unique properties for manipulating biological networks. Here, we increase the regulatory range of the Rnt1p control elements, by modifying a critical region for enzyme binding to its hairpin substrates, the binding stability box (BSB). We used a high throughput, cell-based selection strategy to screen a BSB library for sequences that exhibit low fluorescence and thus high Rnt1p processing efficiencies. Sixteen unique BSBs were identified that cover a range of protein expression levels, due to the ability of the sequences to affect the hairpin cleavage rate and to form active cleavable complexes with Rnt1p. We further demonstrated that the activity of synthetic Rnt1p hairpins can be rationally programmed by combining the synthetic BSBs with a set of sequences located within a different region of the hairpin that directly modulate cleavage rates, providing a modular assembly strategy for this class of RNA-based control elements

Measurement of the neutrino component of an anti-neutrino beam observed by a non-magnetized detector

Two independent methods are employed to measure the neutrino flux of the anti-neutrino-mode beam observed by the MiniBooNE detector. The first method compares data to simulated event rates in a high purity \numu induced charged-current single \pip (CC1\pip) sample while the second exploits the difference between the angular distributions of muons created in \numu and \numub charged-current quasi-elastic (CCQE) interactions. The results from both analyses indicate the prediction of the neutrino flux component of the pre-dominately anti-neutrino beam is over-estimated - the CC1\pip analysis indicates the predicted \numu flux should be scaled by $0.76 \pm 0.11$, while the CCQE angular fit yields $0.65 \pm 0.23$. The energy spectrum of the flux prediction is checked by repeating the analyses in bins of reconstructed neutrino energy, and the results show that the spectral shape is well modeled. These analyses are a demonstration of techniques for measuring the neutrino contamination of anti-neutrino beams observed by future non-magnetized detectors.Comment: 15 pages, 7 figures, published in Physical Review D, latest version reflects changes from referee comment

Search for Charged Current Coherent Pion Production on Carbon in a Few-GeV Neutrino Beam

The SciBooNE Collaboration has performed a search for charged current coherent pion production from muon neutrinos scattering on carbon, \nu_\mu ^{12}C \to \mu^- ^{12}C \pi^+, with two distinct data samples. No evidence for coherent pion production is observed. We set 90% confidence level upper limits on the cross section ratio of charged current coherent pion production to the total charged current cross section at 0.67\times 10^{-2} at mean neutrino energy 1.1 GeV and 1.36\times 10^{-2} at mean neutrino energy 2.2 GeV.Comment: 18 pages, 16 figures, Minor revisions to match version accepted for publication in Physical Review

Population genomics of domestic and wild yeasts

The natural genetics of an organism is determined by the distribution of sequences of its genome. Here we present one- to four-fold, with some deeper, coverage of the genome sequences of over seventy isolates of the domesticated baker's yeast, _Saccharomyces cerevisiae_, and its closest relative, the wild _S. paradoxus_, which has never been associated with human activity. These were collected from numerous geographic locations and sources (including wild, clinical, baking, wine, laboratory and food spoilage). These sequences provide an unprecedented view of the population structure, natural (and artificial) selection and genome evolution in these species. Variation in gene content, SNPs, indels, copy numbers and transposable elements provide insights into the evolution of different lineages. Phenotypic variation broadly correlates with global genome-wide phylogenetic relationships however there is no correlation with source. _S. paradoxus_ populations are well delineated along geographic boundaries while the variation among worldwide _S. cerevisiae_ isolates show less differentiation and is comparable to a single _S. paradoxus_ population. Rather than one or two domestication events leading to the extant baker's yeasts, the population structure of _S. cerevisiae_ shows a few well defined geographically isolated lineages and many different mosaics of these lineages, supporting the notion that human influence provided the opportunity for outbreeding and production of new combinations of pre-existing variation

Racial Disparities in Emergency General Surgery: Do Differences in Outcomes Persist Among Universally Insured Military Patients?

Research Objective: Described as one of the most serious health problems affecting the nation, racial disparities are estimated to account for \u3e83,000 deaths, \u3e$57 billion per year. They have been identified in multiple surgical settings, including differences in outcomes by race among emergency general surgery(EGS) patients. As many minority patients are uninsured, increasing access to care is thought to be a viable solution to mitigate inequities. The objectives of this study were to determine whether racial disparities in 30/90/180day outcomes exist within a universally-insured population of military/civilian-dependent EGS patients and whether differences in outcomes differentially persist in care received at military-vs-civilian hospitals and among sponsors who are enlisted-service members-vs-officers. It also considered longer-term outcomes of care. Study Design: Risk-adjusted survival analyses using Cox proportional-hazards models assessed race-based differences in mortality, major morbidity, and readmission from index-hospital admission (discharge for readmission) through 30/90/180days. Models accounted for hospital clustering and possible biases associated with missing race (reweighted-estimating equations). Sub-analyses considered effects restricted to operative interventions, stratified by 24 EGS-diagnostic categories defined by the American Association for the Surgery of Trauma(AAST), and effect modification related to rank (SES-proxy: officers-vs-enlisted-sponsors) and military-vs-civilian-hospital care. Population Studied: Five years of national TRICARE Prime/Prime-plus data, which provides insurance to active/reserve/retired members of the US Armed Services and dependents, were queried for adults (≥18y) with primary EGS conditions, defined by the AAST. Patients who did not have an index admission between 01/01/2006-01/07/2010 (minimum 180days follow-up) or who were not continuously enrolled in TRICARE for 180days were excluded. Non-surviving patients were retained while they survived. Principal Findings: A total of 101,011 patients were included: 73.5% White, 14.5% Black, 4.4% Asian, 7.7% other. Risk-adjusted analyses reported equivalent-or-better mortality and readmission outcomes among minority patients at 30/90/180days—even when restricted to civilian hospitals where studies suggest that EGS disparities are found. Readmissions within military hospitals were lower among minority patients. Major morbidity was higher among Black versus White patients (HR[95%CI]): 30day-1.23[1.13-1.35], 90day-1.18[1.09-1.28], 180day-1.15[1.07-1.24]—a finding driven by appendiceal disorders (HR:1.69-1.70). No other diagnostic category-based HR was significant. When considered by rank, significant effects were isolated to enlisted-service members. However, given the relatively small number of patients who were (dependents of) officers, it is difficult to determine whether rank-based findings are a result of social determinants or influenced by the limited number of minority patients. Conclusions: The first of its kind to examine racial disparities in longer-term outcomes of EGS care, this longitudinal analysis of military patients demonstrated apparent mitigation of racial disparities within a universally-insured health system when compared to the overall US health system. Efforts to explain findings based on consideration of care provided in military-vs-civilian hospitals, among specific EGS-diagnostic categories, and based on sponsor rank revealed modification of the association between race and outcomes to some extent for all three. Implications for Policy or Practice: The contrast between results for universally-insured military/civilian-dependent patients and reported disparities among all US civilian patients merits consideration. The data speak to the importance of insurance-coverage in the development of disparities interventions nationwide and will help to inform policy within the DoD