Pavement stresses due to tire impact

Road surfaces wear continually under the effects of vehicular motions in an environment of changing temperature, humidity, etc. Regulatory agencies need to set limits on vehicular loads, tire pressures, etc., in order to mitigate the damage caused by the traveling stress footprints of vehicular traffic. In order to understand and quantify the relationship between damage caused and the parameters influencing the forces generated by a moving vehicle on a road surface, it is necessary to construct a model for a mechanical system of vehicle body, suspension springs, axle, wheel rim and tire, transmitting forces back and forward to the road surface. The previous paragraph describes the broad problem presented to the workshop. In what follows we organize a simple mathematical model to represent the major components of the system, and we indicate how this model may be validated (or not) by tests and, if it is successful, how it can be used in a predictive capacity

Solving the cosmic lithium problems with primordial late-decaying particles

We investigate the modifications to predictions for the abundances of light elements from standard Big-Bang nucleosynthesis when exotic late-decaying particles with lifetimes exceeding ~1 sec are prominent in the early Universe. Utilising a model-independent analysis of the properties of these long-lived particles, we identify the parameter space associated with models that are consistent with all observational data and hence resolve the much discussed discrepancies between observations and theoretical predictions for the abundances of Li^7 and Li^6.Comment: 6 pages, 3 figures, submitted to Physical Review D; minor changes to reference

Light neutralino in the MSSM: An update with the latest LHC results

We discuss the scenario of light neutralino dark matter in the minimal supersymmetric standard model, which is motivated by the results of some of the direct detection experiments --- DAMA, CoGENT, and CRESST. We update our previous analysis with the latest results of the LHC. We show that new LHC constraints disfavour the parameter region that can reproduce the results of DAMA and CoGENT.Comment: 4 pages, 4 figures, to appear in the conference proceedings of TAUP 2011, Munich Germany, 5-9 September 201

Z(2)-Singlino Dark Matter in a Portal-Like Extension of the Minimal Supersymmetric Standard Model.

We propose a Z2-stabilized singlino () as a dark matter candidate in extended and R-parity violating versions of the supersymmetric standard model. interacts with visible matter via a heavy messenger field S, which results in a supersymmetric version of the Higgs portal interaction. The relic abundance of can account for cold dark matter if the messenger mass satisfies GeV. Our model can be implemented in many realistic supersymmetric models such as the next-to-minimal supersymmetric (SUSY) standard model and nearly minimal SUSY standard model

Do the Barker Codes End?

A Barker code is a binary code with k^th autocorrelation <= 1 for all nonzero k. At the workshop, the Barker code group split into four non-disjoint subgroups: - An "algebra group", who explored symmetries of the search space that preserve the autocorrelations' magnitude. - A "computing group", who explored methods for quickly finding binary codes with very good autocorrelation properties. - A "statistics group", who explored ways to quantify what has been empirically observed about autocorrelation in the search space S_2^N. - A "continuous group", who explored a non-discrete analogue of the problem of finding sequences with good autocorrelations

A multi-centre cohort study evaluating the role of Inflammatory Markers In patient’s presenting with acute ureteric Colic (MIMIC)

BACKGROUND: Spontaneous Stone Passage (SSP) rates in acute ureteric colic range from 47–75%. There is conflicting evidence on the role of raised inflammatory markers in acute ureteric colic. The use of an easily applicable biomarker that could predict SSP or need for intervention would improve the management of obstructing ureteric stones. Thus, there is a need to determine in an appropriately powered study, in patients who are initially managed conservatively, which factors at the time of acute admission can predict subsequent patient outcome such as SSP and the need for intervention. Particularly, establishing whether levels of white cell count (WBC) at presentation are associated with likelihood of SSP or intervention may guide clinicians on the management of these patients’ stones. DESIGN: Multi-center cohort study disseminated via the UK British Urology Researchers in Surgical Training (BURST) and Australian Young Urology Researchers Organisation (YURO). PRIMARY RESEARCH QUESTION: What is the association between WBC and SSP in patients discharged from emergency department after initial conservative management? PATIENT POPULATION: Patients who have presented with acute renal colic with CT KUB evidence of a solitary ureteric stone. A minimum sample size of 720 patients across 15 centres will be needed. HYPOTHESIS: A raised WBC is associated with decreased odds of spontaneous stone passage. PRIMARY OUTCOME: The occurrence of SSP within six months of presentation with acute ureteric colic (YES/NO). SSP was defined as absence of need for intervention to assist stone passage STATISTICAL ANALYSIS PLAN: A multivariable logistic regression model will be constructed, where the outcome of interest is SSP using data from patients who do not undergo intervention at presentation. A random effect will be used to account for clustering of patients within hospitals/institutions. The model will include adjustments for gender, age as control variables

Signatures of clumpy dark matter in the global 21 cm background signal

We examine the extent to which the self-annihilation of supersymmetric neutralino dark matter, as well as light dark matter, influences the rate of heating, ionisation and Lyman-alpha pumping of interstellar hydrogen and helium and the extent to which this is manifested in the 21cm global background signal. We fully consider the enhancements to the annihilation rate from DM halos and substructures within them. We find that the influence of such structures can result in significant changes in the differential brightness temperature. The changes at redsfhits z<25 are likely to be undetectable due to the presence of the astrophysical signal; however, in the most favourable cases, deviations in the differential brightness temperature, relative to its value in the absence of self-annihilating DM, of up to ~20 mK at z=30 can occur. Thus we conclude that, in order to exclude these models, experiments measuring the global 21cm signal, such as EDGES and CORE, will need to reduce the systematics at 50 MHz to below 20 mK.Comment: V3: 32 pages, 14 figures, 4 tables. Replaced to match version accepted for publication in PRD. Major revisions to address referee's comment

Cosmic Ray Anomalies from the MSSM?

The recent positron excess in cosmic rays (CR) observed by the PAMELA satellite may be a signal for dark matter (DM) annihilation. When these measurements are combined with those from FERMI on the total ($e^++e^-$) flux and from PAMELA itself on the $\bar p/p$ ratio, these and other results are difficult to reconcile with traditional models of DM, including the conventional mSUGRA version of Supersymmetry even if boosts as large as $10^{3-4}$ are allowed. In this paper, we combine the results of a previously obtained scan over a more general 19-parameter subspace of the MSSM with a corresponding scan over astrophysical parameters that describe the propagation of CR. We then ascertain whether or not a good fit to this CR data can be obtained with relatively small boost factors while simultaneously satisfying the additional constraints arising from gamma ray data. We find that a specific subclass of MSSM models where the LSP is mostly pure bino and annihilates almost exclusively into $\tau$ pairs comes very close to satisfying these requirements. The lightest $\tilde \tau$ in this set of models is found to be relatively close in mass to the LSP and is in some cases the nLSP. These models lead to a significant improvement in the overall fit to the data by an amount $\Delta \chi^2 \sim 1/$dof in comparison to the best fit without Supersymmetry while employing boosts $\sim 100$. The implications of these models for future experiments are discussed.Comment: 57 pages, 31 figures, references adde

A case of acute-colonic pseudo-obstruction (Ogilvie Syndrome) post robot-assisted radical prostatectomy

Acute Colonic Pseudo-obstruction (ACPO), or Ogilvie Syndrome, is a rare phenomenon where acute colonic distension occurs, in the absence of mechanical obstruction. Several post-operative cases of Ogilvie Syndrome are noted within the literature, pertaining to patients post hepatectomy, trauma or spinal surgery; but rarely following urological procedures. This case describes a 68-year-old gentleman who developed Ogilvie Syndrome post an uncomplicated robot-assisted radical prostatectomy (RARP). While bowel injury is an acknowledged rare complication following prostatectomy, patients with Ogilvie Syndrome may present in a similar manner, and an atypical case of colonic obstruction should raise suspicion of this as a cause