The dark side of mSUGRA

We study the mu<0 branch of the minimal supergravity ansatz of the minimal supersymmetric standard model. The extent to which mu<0 is disfavoured compared to mu>0 in global fits is calculated with Markov Chain Monte Carlo methods and bridge sampling. The fits include state-of-the-art two-loop MSSM contributions to the electroweak observables M_W and sin^2 theta_w^l, as well as the anomalous magnetic moment of the muon (g-2)_mu, the relic density of dark matter and other relevant indirect observables. mu<0 is only marginally disfavoured in global fits and should be considered in mSUGRA analyses. We estimate that the ratio of probabilities is P(mu0)=0.07-0.16

Natural priors, CMSSM fits and LHC weather forecasts

Previous LHC forecasts for the constrained minimal supersymmetric standard model (CMSSM), based on current astrophysical and laboratory measurements, have used priors that are flat in the parameter tan beta, while being constrained to postdict the central experimental value of MZ. We construct a different, new and more natural prior with a measure in mu and B (the more fundamental MSSM parameters from which tan beta and MZ are actually derived). We find that as a consequence this choice leads to a well defined fine-tuning measure in the parameter space. We investigate the effect of such on global CMSSM fits to indirect constraints, providing posterior probability distributions for Large Hadron Collider (LHC) sparticle production cross sections. The change in priors has a significant effect, strongly suppressing the pseudoscalar Higgs boson dark matter annihilation region, and diminishing the probable values of sparticle masses. We also show how to interpret fit information from a Markov Chain Monte Carlo in a frequentist fashion; namely by using the profile likelihood. Bayesian and frequentist interpretations of CMSSM fits are compared and contrasted

Osteochondral Tissue Engineering: The Potential of Electrospinning and Additive Manufacturing

The socioeconomic impact of osteochondral (OC) damage has been increasing steadily over time in the global population, and the promise of tissue engineering in generating biomimetic tissues replicating the physiological OC environment and architecture has been falling short of its projected potential. The most recent advances in OC tissue engineering are summarised in this work, with a focus on electrospun and 3D printed biomaterials combined with stem cells and biochemical stimuli, to identify what is causing this pitfall between the bench and the patients' bedside. Even though significant progress has been achieved in electrospinning, 3D-(bio)printing, and induced pluripotent stem cell (iPSC) technologies, it is still challenging to artificially emulate the OC interface and achieve complete regeneration of bone and cartilage tissues. Their intricate architecture and the need for tight spatiotemporal control of cellular and biochemical cues hinder the attainment of long-term functional integration of tissue-engineered constructs. Moreover, this complexity and the high variability in experimental conditions used in different studies undermine the scalability and reproducibility of prospective regenerative medicine solutions. It is clear that further development of standardised, integrative, and economically viable methods regarding scaffold production, cell selection, and additional biochemical and biomechanical stimulation is likely to be the key to accelerate the clinical translation and fill the gap in OC treatment

Nonparabolicity effects on electron-optical-phonon scattering rates in quantum wells

The scattering rates for intrasubband and intersubband transitions due to electron-optical-phonon interaction are calculated for GaAs-AlxGa1-xAs quantum wells taking into account the conduction subband nonparabolicity. For the description of the confined-and interface-phonon modes we use a dielectric continuum model and the nonparabolic conduction-subband energy is introduced as a second order expansion of k(2), the square of the electron wave vector. Our results show that for transitions due to the emission of confined phonons the scattering rates are significantly increased, while for interface phonons the scattering rates are decreased. In particular, we show that for high kinetic energies electrons will relax at an almost constant rates for quantum wells larger than 120 Angstrom. We show that our results can be understood in terms of the phonon wave vector (or Frohlich electron-phonon coupling), the density of final states, and the electron-phonon overlap.56159619962

Electron-phonon relaxation rates in InGaAs-InP and HgCdTe-CdTe quantum wells

We calculate electron-LO-confined and interface-phonon scattering rates in In1-xGaxAs-InP and Hg1-xCdxTe-CdTe quantum wells considering the influence of nonparabolicity on the energy subbands. A simple k . p model is used to take into account this nonparabolicity and a reformulated dielectric continuum slab model is employed to describe the confined phonon modes. We find that the subband nonparabolicity increases the scattering rates significantly for all transitions and that this effect is more pronounced as transitions from higher subbands are involved. We show that this behavior can be understood in terms of the phonon wave vector, the density of final states and the electron-phonon overlap. (C) 1999 American Institute of Physics. [S0021-8979(99)01410-3].85107276728

The UK register of HIV seroconverters: Methods and analytical issues

A Register of HIV-infected persons who have had a negative antibody test within 3 years of their first antibody positive test (seroconverters) is being set up in the UK to monitor the distribution of times from HIV seroconversion to AIDS (the incubation period) and to death. It will also provide a national resource for use by those designing studies in this group of individuals. Clinicians caring for HIV-positive persons in Genito-Urinary Medicine, Infectious Disease and other departments throughout the UK were asked to participate by providing information on eligible subjects. Most laboratories undertaking HIV antibody testing were also contacted and asked to provide the name of the attending clinician for all seroconverters identified through the HIV laboratory reporting systems of the PHLS Communicable Disease Surveillance Centre (CDSC) and the Scottish Centre for Infection and Environmental Health (SCIEH) and for any other seroconverters known to them but not identified by CDSC or SCIEH. Data items sought for the Register include: sex, ethnic group, probable route of HIV transmission, annual CD4 counts, details of therapy and prophylaxis prescribed, AIDS-defining events and vital status. Follow up information is collected annually. Wherever possible, all seroconverters known to a clinic have been identified, whether currently alive or dead, either from clinic records or laboratory reporting or both. The objective is to establish and update a complete register of seroconverters on a long-term basis to provide reliable estimates of the incubation period on which future projections of AIDS cases in the UK can be made

Analyses of Ligand Binding to IP3 Receptors Using Fluorescence Polarization.

Fluorescence polarization (FP) can be used to measure binding of a small fluorescent ligand to a larger protein because the ligand rotates more rapidly in its free form than when bound. When excited with plane polarized light, the free fluorescent ligand emits depolarized light, which can be quantified. Upon binding, its rotation is reduced and more of the emitted light remains polarized. This allows FP to be used as a nondestructive assay of ligand binding. Here we describe a fast, high-throughput FP assay to quantify the binding of fluorescently labeled inositol 1,4,5-trisphosphate (IP3) to N-terminal fragments of the IP3 receptor. The assay is fast (1-6 h), it avoids use of radioactive materials and when measurements are performed at different temperatures, it can resolve Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) changes of ligand binding

Prolapse or incontinence: what affects sexual function the most?

Introduction and hypothesis Pelvic organ prolapse (POP) and stress urinary incontinence (SUI) adversely affect sexual function in women. Comparative studies of the two subgroups are few and results are conflicting. The aim of this study was to compare the effect of POP and SUI on the sexual function of women undergoing surgery for these conditions. Methods The study population comprised women with POP or SUI in a tertiary referral hospital in the UK. Women who underwent SUI surgery had no symptoms of POP and had urodynamically proven stress incontinence. Patients with POP had ≥ stage 2 prolapse, without bothersome urinary symptoms. Pre-operative data on sexual function were collected and compared using an electronic pelvic floor assessment questionnaire (ePAQ). The incidence of sexual dysfunction and comparison of symptoms in both groups were calculated using the Mann–Whitney U test. Results Three hundred and forty-three women undergoing surgery for either SUI or POP were included. Patients were age-matched, with 184 undergoing SUI surgery (age range 33–77 years) and 159 POP surgery (age range 27–78 years; p = 0.869). The overall impact of POP and SUI was not significantly different in the two subgroups (p = 0.703). However, both patients (73 % vs 36 %; p = 0.00) and partners (50 % vs 24 %; p = 0.00) avoid intercourse significantly more frequently in cases with POP compared with SUI. This did not have a significant impact on quality of life. Conclusions The impact of bothersome SUI or POP on sexual function was found to be similar, but patient and partner avoidance in women with POP was greater than those with SUI

Quantum nondemolition measurement of mechanical motion quanta

The fields of opto- and electromechanics have facilitated numerous advances in the areas of precision measurement and sensing, ultimately driving the studies of mechanical systems into the quantum regime. To date, however, the quantization of the mechanical motion and the associated quantum jumps between phonon states remains elusive. For optomechanical systems, the coupling to the environment was shown to preclude the detection of the mechanical mode occupation, unless strong single photon optomechanical coupling is achieved. Here, we propose and analyse an electromechanical setup, which allows to overcome this limitation and resolve the energy levels of a mechanical oscillator. We find that the heating of the membrane, caused by the interaction with the environment and unwanted couplings, can be suppressed for carefully designed electromechanical systems. The results suggest that phonon number measurement is within reach for modern electromechanical setups.Comment: 8 pages, 5 figures plus 24 pages, 11 figures supplemental materia