A penalty function method for computing chemical equilibria

A penalty function technique is developed as an alternative method for handling precipitation-dissolution reactions in the equilibrium constant method of solving the batch chemical equilibrium problem. It is simple to incorporate into existing programs which do not handle precipitation-dissolution reactions. No variable eliminations need to be performed and the size of the system is always the same even as additional solids enter the problem. Two sample problems are presented to demonstrate the implementation of the method.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28768/1/0000600.pd

An iterative compositional model for subsurface multiphase flow

The governing equations describing multiphase flow with multicomponent solute transport may be cast in a number of forms. While mathematically equivalent, the numerical models based on each formulation differ in flexibility and efficiency. The set-iterative compositional formulation, a mathematical formulation that separates the solution of the phase-balance equations from the species balance is described herein. A mathematical model based on this formulation describes the flow of two mobile phases. Each phase may transport multiple chemical components. Mass exchange between phases is expressed by a linear kinetic equation. The numerical model based on the set-iterative compositional formulation is shown to model non-equilibrium phase partitioning, to provide a flexible framework that may be applied to organic mixtures with differing numbers of components and to yield a more efficient solution in comparison with models arising from standard compositional formulations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31668/1/0000604.pd

A coaching program to improve dietary intake of patients with CKD: ENTICE-CKD

The dietary self-management of CKD is challenging. Telehealth interventions may provide an effective delivery method to facilitate sustained dietary change.This pilot, randomized, controlled trial evaluated secondary and exploratory outcomes after a dietitian-led telehealth coaching intervention to improve diet quality in people with stage 3-4 CKD. The intervention group received phone calls every 2 weeks for 3 months (with concurrent, tailored text messages for 3 months), followed by 3 months of tailored text messages without telephone coaching, to encourage a diet consistent with CKD guidelines. The control group received usual care for 3 months, followed by nontailored, educational text messages for 3 months.Eighty participants (64% male), aged 62±12 years, were randomized to the intervention or control group. Telehealth coaching was safe, with no adverse events or changes to serum biochemistry at any time point. At 3 months, the telehealth intervention, compared with the control, had no detectable effect on overall diet quality on the Alternative Health Eating Index (3.2 points, 95% confidence interval, -1.3 to 7.7), nor at 6 months (0.5 points, 95% confidence interval, -4.6 to 5.5). There was no change in clinic BP at any time point in any group. There were significant improvements in several exploratory diet and clinical outcomes, including core food group consumption, vegetable servings, fiber intake, and body weight.Telehealth coaching was safe, but appeared to have no effect on the Alternative Healthy Eating Index or clinic BP. There were clinically significant changes in several exploratory diet and clinical outcomes, which require further investigation.Evaluation of Individualized Telehealth Intensive Coaching to Promote Healthy Eating and Lifestyle in CKD (ENTICE-CKD), ACTRN12616001212448

Susceptibility testing of Haemophilus influenzae— an international collaborative study in quality assessment

In order to compare the prevalence of antibiotic resistance in different geographical areas, it is necessary to ensure that agreement is achieved between laboratories on the assignment of strains to ‘susceptible' and ‘resistant' categories. An international quality assessment study, involving 15 laboratories in eight countries, was performed to investigate the standard of performance of the susceptibility testing of Haemophilus influenzae. One hundred and fifty strains of H. influenzae were distributed from the London Hospital Medical College (LHMC) to all laboratories who were asked to test the susceptibility of the strains to ampicillin, chloramphenicol, tetracycline, trimethoprim, cephalosporins and ciprofloxacin. Laboratories were also asked to provide the details of methodology to test the susceptibility. Significant discrepancy between the LHMC and the participating laboratories appeared in the detection of resistance to ampicillin (especially β-lactamase-negative strains resistant to ampicillin) as well as the assignment of susceptibility and resistance to chloramphenicol, tetracycline and trimethoprim. Often these reflected the use of inappropriate breakpoints which led to erroneous assignment of susceptibility. Other variations including disc content, medium and supplement, inoculum as well as failure to measure zone sizes properly also led to some repeating anomalie

A review of the design and clinical evaluation of the ShefStim array-based functional electrical stimulation system

Functional electrical stimulation has been shown to be a safe and effective means of correcting foot 12 drop of central neurological origin. Current surface-based devices typically consist of a single channel stimulator, 13 a sensor for determining gait phase and a cuff, within which is housed the anode and cathode. The cuff-mounted 14 electrode design reduces the likelihood of large errors in electrode placement, but the user is still fully responsible 15 for selecting the correct stimulation level each time the system is donned. Researchers have investigated different 16 approaches to automating aspects of setup and/or use, including recent promising work based on iterative learning 17 techniques. This paper reports on the design and clinical evaluation of an electrode array-based FES system for 18 the correction of drop foot, ShefStim. The paper reviews the design process from proof of concept lab-based study, 19 through modelling of the array geometry and interface layer to array search algorithm development. Finally, the 20 paper summarises two clinical studies involving patients with drop foot. The results suggest that the ShefStim 21 system with automated setup produces results which are comparable with clinician setup of conventional systems. 22 Further, the final study demonstrated that patients can use the system without clinical supervision. When used 23 unsupervised, setup time was 14 minutes (9 minutes for automated search plus 5 minutes for donning the 24 equipment), although this figure could be reduced significantly with relatively minor changes to the design

Stable, Precise, and Reproducible Patterning of Bicoid and Hunchback Molecules in the Early Drosophila Embryo

Precise patterning of morphogen molecules and their accurate reading out are of key importance in embryonic development. Recent experiments have visualized distributions of proteins in developing embryos and shown that the gradient of concentration of Bicoid morphogen in Drosophila embryos is established rapidly after fertilization and remains stable through syncytial mitoses. This stable Bicoid gradient is read out in a precise way to distribute Hunchback with small fluctuations in each embryo and in a reproducible way, with small embryo-to-embryo fluctuation. The mechanisms of such stable, precise, and reproducible patterning through noisy cellular processes, however, still remain mysterious. To address these issues, here we develop the one- and three-dimensional stochastic models of the early Drosophila embryo. The simulated results show that the fluctuation in expression of the hunchback gene is dominated by the random arrival of Bicoid at the hunchback enhancer. Slow diffusion of Hunchback protein, however, averages out this intense fluctuation, leading to the precise patterning of distribution of Hunchback without loss of sharpness of the boundary of its distribution. The coordinated rates of diffusion and transport of input Bicoid and output Hunchback play decisive roles in suppressing fluctuations arising from the dynamical structure change in embryos and those arising from the random diffusion of molecules, and give rise to the stable, precise, and reproducible patterning of Bicoid and Hunchback distributions

Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using √s=8 TeV proton-proton collision data

A search for squarks and gluinos in final states containing high-p T jets, missing transverse momentum and no electrons or muons is presented. The data were recorded in 2012 by the ATLAS experiment in s√=8 TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 20.3 fb−1. Results are interpreted in a variety of simplified and specific supersymmetry-breaking models assuming that R-parity is conserved and that the lightest neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 1330 GeV for a simplified model incorporating only a gluino and the lightest neutralino. For a simplified model involving the strong production of first- and second-generation squarks, squark masses below 850 GeV (440 GeV) are excluded for a massless lightest neutralino, assuming mass degenerate (single light-flavour) squarks. In mSUGRA/CMSSM models with tan β = 30, A 0 = −2m 0 and μ > 0, squarks and gluinos of equal mass are excluded for masses below 1700 GeV. Additional limits are set for non-universal Higgs mass models with gaugino mediation and for simplified models involving the pair production of gluinos, each decaying to a top squark and a top quark, with the top squark decaying to a charm quark and a neutralino. These limits extend the region of supersymmetric parameter space excluded by previous searches with the ATLAS detector

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

Measurement of the flavour composition of dijet events in pp collisions at root s=7 TeV with the ATLAS detector

This paper describes a measurement of the flavour composition of dijet events produced in pp collisions at √s=7 TeV using the ATLAS detector. The measurement uses the full 2010 data sample, corresponding to an integrated luminosity of 39 pb−1. Six possible combinations of light, charm and bottom jets are identified in the dijet events, where the jet flavour is defined by the presence of bottom, charm or solely light flavour hadrons in the jet. Kinematic variables, based on the properties of displaced decay vertices and optimised for jet flavour identification, are used in a multidimensional template fit to measure the fractions of these dijet flavour states as functions of the leading jet transverse momentum in the range 40 GeV to 500 GeV and jet rapidity |y|<2.1. The fit results agree with the predictions of leading- and next-to-leading-order calculations, with the exception of the dijet fraction composed of bottom and light flavour jets, which is underestimated by all models at large transverse jet momenta. The ability to identify jets containing two b-hadrons, originating from e.g. gluon splitting, is demonstrated. The difference between bottom jet production rates in leading and subleading jets is consistent with the next-to-leading-order predictions