A model-independent maximum range for the liquidity correction of TIPS yields

We derive a model-independent maximum range for the admissible liquidity risk premium in real Treasury bonds—also known as Treasury Inflation Protected Securities (TIPS). The range is constructed using additional information in the inflation swap market and a set of simple theoretical assumptions. As an application, we construct a lower bound to estimates of the inflation risk premium the Treasury receives from TIPS by deducting their maximum liquidity premium. This conservative measure of the benefit to the Treasury of issuing TIPS is positive on average at the ten-year maturity for our sample period.Inflation (Finance) ; Inflation-indexed bonds

The use of Hemopure® at Groote Schuur hospital, Cape Town: 4 case studies

Hemopure® is a cell-free haemoglobin solution that is made from bovine haemoglobin that is designed to carry oxygen in the plasma. It is approved for use in South Africa for the treatment of acute surgical anaemia. We describe the use of Hemopure® at a large tertiary hospital in Cape Town where there is a blood bank on the premises. Four patients received Hemopure® during situations of acute, life-threatening anaemia. Two patients were Jehovah’s Witnesses and in two cases the blood bank was not able to find compatible blood due to the presence of antibodies in the patient’s blood. Patients were carefully monitored by the anaesthetists or intensive care staff, who were managing the patient. No adverse reactions were experienced. Hemopure® was indispensable in managing these critically ill patients

Gluino decays with heavier scalar superpartners

We compute gluino decay widths in supersymmetric theories with arbitrary flavor and CP violation angles. Our emphasis is on theories with scalar superpartner masses heavier than the gluino such that tree-level two-body decays are not allowed, which is relevant, for example, in split supersymmetry. We compute gluino decay branching fractions in several specific examples and show that it is plausible that the only accessible signal of supersymmetry at the LHC could be four top quarks plus missing energy. We show another example where the only accessible signal for supersymmetry is two gluon jets plus missing energy.Comment: 17 pages, 8 figures. Added references and minor typos and errors corrected (no change in numerical results

High seroprevalence of human herpesviruses in HIV-infected individuals attending primary healthcare facilities in rural South Africa

Seroprevalence data of human herpesviruses (HHVs) are limited for sub-Saharan Africa. These are important to provide an indication of potential burden of HHV-related disease, in particular in human immunodeficiency virus (HIV)-infected individuals who are known to be at increased risk of these conditions in the Western world. In this cross-sectional study among 405 HIV-infected and antiretroviral therapy naïve individuals in rural South Africa the seroprevalence of HHVs was: herpes simplex virus type 1 (HSV-1) (98%), herpes simplex virus type 2 (HSV-2) (87%), varicella zoster virus (VZV) (89%), and 100% for both Epstein-Barr virus (EBV) and cytomegalovirus (CMV). Independent factors associated with VZV seropositivity were low educational status and having children. Lack of in-house access to drinking water was independently associated with positive HSV-1 serostatus, whereas Shangaan ethnicity was associated with HSV-2 seropositivity. Increasing age was associated with higher IgG titres to both EBV and CMV, whereas CD4 cell count was negatively associated with EBV and CMV IgG titres. Moreover, IgG titres of HSV-1 and 2, VZV and CMV, and CMV and EBV were positively correlated. The high HHV seroprevalence emphasises the importance of awareness of these viral infections in HIV-infected individuals in South Africa

Higgs boson mass limits in perturbative unification theories

Motivated in part by recent demonstrations that electroweak unification into a simple group may occur at a low scale, we detail the requirements on the Higgs mass if the unification is to be perturbative. We do this for the Standard Model effective theory, minimal supersymmetry, and next-to-minimal supersymmetry with an additional singlet field. Within the Standard Model framework, we find that perturbative unification with sin2(thetaW)=1/4 occurs at Lambda=3.8 TeV and requires mh<460 GeV, whereas perturbative unification with sin2(thetaW)=3/8 requires mh<200 GeV. In supersymmetry, the presentation of the Higgs mass predictions can be significantly simplified, yet remain meaningful, by using a single supersymmetry breaking parameter Delta_S. We present Higgs mass limits in terms of Delta_S for the minimal supersymmetric model and the next-to-minimal supersymmetric model. We show that in next-to-minimal supersymmetry, the Higgs mass upper limit can be as large as 500 GeV even for moderate supersymmetry masses if the perturbative unification scale is low (e.g., Lambda=10 TeV).Comment: 20 pages, latex, 6 figures, references adde

Supersymmetry Without Prejudice at the LHC

The discovery and exploration of Supersymmetry in a model-independent fashion will be a daunting task due to the large number of soft-breaking parameters in the MSSM. In this paper, we explore the capability of the ATLAS detector at the LHC ($\sqrt s=14$ TeV, 1 fb$^{-1}$) to find SUSY within the 19-dimensional pMSSM subspace of the MSSM using their standard transverse missing energy and long-lived particle searches that were essentially designed for mSUGRA. To this end, we employ a set of $\sim 71$k previously generated model points in the 19-dimensional parameter space that satisfy all of the existing experimental and theoretical constraints. Employing ATLAS-generated SM backgrounds and following their approach in each of 11 missing energy analyses as closely as possible, we explore all of these $71$k model points for a possible SUSY signal. To test our analysis procedure, we first verify that we faithfully reproduce the published ATLAS results for the signal distributions for their benchmark mSUGRA model points. We then show that, requiring all sparticle masses to lie below 1(3) TeV, almost all(two-thirds) of the pMSSM model points are discovered with a significance $S>5$ in at least one of these 11 analyses assuming a 50\% systematic error on the SM background. If this systematic error can be reduced to only 20\% then this parameter space coverage is increased. These results are indicative that the ATLAS SUSY search strategy is robust under a broad class of Supersymmetric models. We then explore in detail the properties of the kinematically accessible model points which remain unobservable by these search analyses in order to ascertain problematic cases which may arise in general SUSY searches.Comment: 69 pages, 40 figures, Discussion adde

Top Squarks and Bottom Squarks in the MSSM with Complex Parameters

We present a phenomenological study of top squarks (~t_1,2) and bottom squarks (~b_1,2) in the Minimal Supersymmetric Standard Model (MSSM) with complex parameters A_t, A_b, \mu and M_1. In particular we focus on the CP phase dependence of the branching ratios of (~t_1,2) and (~b_1,2) decays. We give the formulae of the two-body decay widths and present numerical results. We find that the effect of the phases on the (~t_1,2) and (~b_1,2) decays can be quite significant in a large region of the MSSM parameter space. This could have important implications for (~t_1,2) and (~b_1,2) searches and the MSSM parameter determination in future collider experiments. We have also estimated the accuracy expected in the determination of the parameters of ~t_i and ~b_i by a global fit of the measured masses, decay branching ratios and production cross sections at e^+ e^- linear colliders with polarized beams. Analysing two scenarios, we find that the fundamental parameters apart from A_t and A_b can be determined with errors of 1% to 2%, assuming an integrated luminosity of 1 ab^-1 and a sufficiently large c.m.s. energy to produce also the heavier ~t_2 and ~b_2 states. The parameter A_t can be determined with an error of 2 - 3%, whereas the error on A_b is likely to be of the order of 50%.Comment: 31 pages, 8 figures, comments and references added, conclusions unchanged; version to appear in Phys. Rev.

Influence of Grain Boundary Character on Creep Void Formation in Alloy 617

Alloy 617, a high temperature creep-resistant, nickel-based alloy, is being considered for the primary heat exchanger for the Next Generation Nuclear Plant (NGNP) which will operate at temperatures exceeding 760oC. Orientation imaging microscopy (OIM) is used to characterize the grain boundaries in the vicinity of creep voids that develop during high temperature creep tests (800-1000oC at creep stresses ranging from 20-85 MPa) terminated at creep strains ranging from 5-40%. Observations using optical microscopy indicate creep rate does not significantly influence the creep void fraction at a given creep strain. Preliminary analysis of the OIM data indicates voids tend to form on grain boundaries parallel, perpendicular or 45o to the tensile axis, while few voids are found at intermediate inclinations to the tensile axis. Random grain boundaries intersect most voids while CSL-related grain boundaries did not appear to be consistently associated with void development

Search for single top quarks in the tau+jets channel using 4.8 fb−1^{-1} of ppˉp\bar{p} collision data

We present the first direct search for single top quark production using tau leptons. The search is based on 4.8 fb$^{-1}$ of integrated luminosity collected in $p\bar{p}$ collisions at $\sqrt{s}$=1.96 TeV with the D0 detector at the Fermilab Tevatron Collider. We select events with a final state including an isolated tau lepton, missing transverse energy, two or three jets, one or two of them $b$ tagged. We use a multivariate technique to discriminate signal from background. The number of events observed in data in this final state is consistent with the signal plus background expectation. We set in the tau+jets channel an upper limit on the single top quark cross section of \TauLimObs pb at the 95% C.L. This measurement allows a gain of 4% in expected sensitivity for the observation of single top production when combining it with electron+jets and muon+jets channels already published by the D0 collaboration with 2.3 fb$^{-1}$ of data. We measure a combined cross section of \SuperCombineXSall pb, which is the most precise measurement to date.Comment: 12 pages, 5 figure