470 research outputs found

    Analysis of a model with a common source of CP violation

    Full text link
    We work in a model where all CP violating phenomena have a common source. CP is spontaneously broken at a large scale VV through the phase of a complex singlet scalar. An additional SU(2)LSU(2)_L singlet vector-like down-type quark relates this high scale CP violation to low energy. We quantitatively analyze this model in the quark sector. We obtain the numerical values of the parameters of the Lagrangian in the quark sector for a specific ansatz of the 4×44\times4 down-type quark mass matrix where the weak phase is generated minimally. ZbˉbZ \bar b b vertex will modify in presence of the extra vector-like down-type quark. From the experimental lower bound of the partial decay width ZbˉbZ\to \bar b b we find out the lower bound of the additional down-type quark mass. Tree level flavor changing neutral current appears in this model due to the presence of the extra vector-like down-type quark. We give the range of values of the mass splitting ΔmBq\Delta m_{B_q} in Bq0Bˉq0B^0_q-{\bar B}^0_q system using SM box, ZZ mediating tree level and ZZ mediating one loop diagrams together for both q=d,sq=d, s. We find out the analytical expression for Γ12q\Gamma_{12}^q in this model from standard box, ZZ and Higgs mediated penguin diagrams for Bq0Bˉq0B^0_q-{\bar B}^0_q system, q=d,sq=d,s. From this we numerically evaluate the decay width difference ΔΓBq/ΓBq|\Delta\Gamma_{B_q}/\Gamma_{B_q}|. We also find out the numerical values of the CP asymmetry parameters aJa_J and aπa_\pi for the decays Bd0J/ψKsB^0_d\to J/\psi K_s and Bd0π+πB^0_d\to \pi^+ \pi^- respectively. We get the lower bound of the scale VV through the upper bound of the strong CP phase.Comment: 20 pages, no figures New materials and references have been added. Text has been modified. To be appear in J.Phys.

    Effects of mitochondrial dysfunction on the immunological properties of microglia

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Neurodegenerative diseases are characterized by both mitochondrial dysfunction and activation of microglia, the macrophages of the brain. Here, we investigate the effects of mitochondrial dysfunction on the activation profile of microglial cells.</p> <p>Methods</p> <p>We incubated primary mouse microglia with the mitochondrial toxins 3-nitropropionic acid (3-NP) or rotenone. These mitochondrial toxins are known to induce neurodegeneration in humans and in experimental animals. We characterized lipopolysaccharide- (LPS-) induced microglial activation and the alternative, interleukin-4- (IL-4-) induced microglial activation in these mitochondrial toxin-treated microglial cells.</p> <p>Results</p> <p>We found that, while mitochondrial toxins did not affect LPS-induced activation, as measured by release of tumor necrosis factor α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β), they did inhibit part of the IL-4-induced alternative activation, as measured by arginase activity and expression, induction of insulin-like growth factor 1 (IGF-1) and the counteraction of the LPS induced cytokine release.</p> <p>Conclusions</p> <p>Mitochondrial dysfunction in microglial cells inhibits part of the IL-4-induced alternative response. Because this alternative activation is considered to be associated with wound healing and an attenuation of inflammation, mitochondrial dysfunction in microglial cells might contribute to the detrimental effects of neuroinflammation seen in neurodegenerative diseases.</p

    Systematic Investigations into the Numerical Response Prediction of a Solar Array Stack under Acoustic Excitation

    Get PDF
    Satellites and payloads launched with large launch vehicles equipped with solid rocket boosters, e.g. ARIANE-5 and NSTS, will be subject to high noise levels during lift-off and atmospheric flight. Particularly sub-systems that have a large surface area and low mass can be very sensitive to acoustic excitation. Examples of such sub-systems are antenna reflectors and solar arrays. This paper presents the main results of a study that follows a systematic approach to investigate the numerical response prediction of a solar array stack, i.e. a solar array in stowed configuration, subject to acoustic excitation. The study has been carried out by Fokker Space (NL) and Metravib R.D.S. (F) under an ESA research and development contract. The hardware selected for the study has been the ARAFOM 5-panel wing. In the frame of the study, the wing has undergone a sequence of mechanical tests, namely a · modal survey test in air and in helium · shaker test with harmonic base excitation (sine test) · acoustic plane wave test · acoustic noise test Results of the modal survey and the sine test, particularly of the modal survey under helium providing a quasi-vacuum environment, have been used to correlate and update the initial mathematical finite element model of the wing. The target of this first step has been to establish a finite element model of the wing that represents as best as possible the dynamic characteristics of the the wing under vacuum conditions. The effects of the air on the dynamic response of the wing have then been modelled by a boundary element approach. This can accurately represent the fluid pressure and radiation impedance loads on the structure. A particular difficulty has been the modelling of the thin air gaps in between the individual panels of the wing. Responses of the wing to acoustic plane wave excitation have been computed and have been correlated with the responses measured from the acoustic plane wave testResponses have been evaluated in terms of structural accelerations and stresses, but also in terms of acoustic pressures in the inter panel gaps and the surrounding fluid. Eventually, the response of the wing to acoustic noise excitation has been numerically simulated using a superposition of plane acoustic waves, and the results have been correlated with the responses from the acoustic noise test

    Ocular, bulbar, limb, and cardiopulmonary involvement in oculopharyngeal muscular dystrophy

    Get PDF
    OBJECTIVES: To assess skeletal muscle weakness and progression as well as the cardiopulmonary involvement in oculopharyngeal muscular dystrophy (OPMD). MATERIALS AND METHODS: Cross-sectional study including symptomatic patients with genetically confirmed OPMD. Patients were assessed by medical history, ptosis, ophthalmoplegia, facial and limb strength, and swallowing capability. Cardiopulmonary function was evaluated using forced expiratory capacity in 1 s (FEV1), electrocardiogram (ECG), Holter monitoring, and echocardiography. RESULTS: We included 13 symptomatic patients (six males, mean age; 64 years (41-80) from 8 families. Ptosis was the first symptom in 8/13 patients followed by limb weakness in the remaining 5 patients Dysphagia was never the presenting symptom. At the time of examination, all affected patients had ptosis or had previously been operated for ptosis, while ophthalmoplegia was found in 9 patients. Dysphagia, tested by cold-water swallowing test, was abnormal in 9 patients (17-116 s, ref &lt;8 s). Six patients could not climb stairs of whom two were wheelchair bound and one used a rollator. Six patients had reduced FEV1 (range 23%-59%). No cardiac involvement was identified. CONCLUSIONS: Limiting limb weakness is common in OPMD and can even be the presenting symptom of the disease. In contrast, dysphagia was not the initial symptom in any of our patients, although it was obligatory for diagnosing OPMD before genetic testing became available. Mild respiratory dysfunction, but no cardiac involvement, was detected

    Impairments in contractility and cytoskeletal organisation cause nuclear defects in nemaline myopathy

    Get PDF
    Nemaline myopathy (NM) is a skeletal muscle disorder caused by mutations in genes that are generally involved in muscle contraction, in particular those related to the structure and/or regulation of the thin filament. Many pathogenic aspects of this disease remain largely unclear. Here, we report novel pathological defects in skeletal muscle fibres of mouse models and patients with NM: irregular spacing and morphology of nuclei; disrupted nuclear envelope; altered chromatin arrangement; and disorganisation of the cortical cytoskeleton. Impairments in contractility are the primary cause of these nuclear defects. We also establish the role of microtubule organisation in determining nuclear morphology, a phenomenon which is likely to contribute to nuclear alterations in this disease. Our results overlap with findings in diseases caused directly by mutations in nuclear envelope or cytoskeletal proteins. Given the important role of nuclear shape and envelope in regulating gene expression, and the cytoskeleton in maintaining muscle fibre integrity, our findings are likely to explain some of the hallmarks of NM, including contractile filament disarray, altered mechanical properties and broad transcriptional alterations

    Hypertension alters the function and expression profile of the peptide cotransporters PEPT1 and PEPT2 in the rodent renal proximal tubule

    Get PDF
    Hypertension is a major risk factor for kidney and cardiovascular disease. The treatment of hypertensive individuals by selected ACE inhibitors and certain di-and tripeptides halts the progression of renal deterioration and extends life-span. Renal reabsorption of these low molecular weight substrates are mediated by the PEPT1 and PEPT2 cotransporters. This study aims to investigate whether hypertension and ageing affects renal PEPT cotransporters at gene, protein expression and distribution as well as function in the superficial cortex and the outer medulla of the kidney. Membrane vesicles from the brush border (BBMV) and outer medulla (OMMV) were isolated from the kidneys of young Wistar Kyoto (Y-WKY), young spontaneously hypertensive (Y-SHR), and middle aged SHR (M-SHR) rats. Transport activity was measured using the substrate, β-Ala-Lys (AMCA). Gene expression levels of PEPT genes were assessed with qRT-PCR while renal localisation of PEPT cotransporters was examined by immunohistochemistry with Western Blot validation. The Km and Vmax of renal PEPT1 were decreased significantly in SHR compared to WKY BBMV, whilst the Vmax of PEPT2 showed differences between SHR and WKY. By contrast to the reported cortical distribution of PEPT1, PEPT1-staining was detected in the outer medulla, whilst PEPT2 was expressed primarily in the cortex of all SHR; PEPT1 was significantly upregulated in the cortex of Y-SHR. These outcomes are indicative of a redistribution of PEPT1 and PEPT2 in the kidney proximal tubule under hypertensive conditions that has potential repercussions for nutrient handling and the therapeutic use of ACE inhibitors in hypertensive individuals

    Beyond the ‘Tomlinson Trap’: analysing the effectiveness of section 1 of the Compensation Act 2006

    Get PDF
    One of the intentions underpinning section 1 of the Compensation Act 2006 was to provide reassurance to individual volunteers, and voluntary organisations, involved in what the provision called ‘desirable activities’ and including sport. The perception was that such volunteers, motivated by an apprehension about their increased vulnerability to negligence liability, and as driven by a fear of a wider societal compensation culture, were engaging excessively in risk-averse behaviour to the detriment of such socially desirable activities. Academic commentary on section 1 of the Compensation Act 2006 has largely regarded the provision as unnecessary and doing little more than restating existing common law practice. This article argues otherwise and, on critically reviewing the emerging jurisprudence, posits the alternative view that section 1, in practice, affords an enhanced level of protection and safeguarding for individuals undertaking functions in connection with a desirable activity. Nonetheless, the occasionally idiosyncratic judicial interpretation given to term ‘desirable activity’, potentially compounded by recent enactment of the Social Action, Responsibility and Heroism Act 2015, remains problematic. Two points of interest will be used to inform this debate. First, an analysis of the then House of Lords’ decision in Tomlinson and its celebrated ‘balancing exercise’ when assessing reasonableness in the context of negligence liability. Second, a fuller analysis of the application of section 1 in the specific context of negligence actions relating to the coaching of sport where it is argued that the, albeit limited, jurisprudence might support the practical utility of a heightened evidential threshold of gross negligence

    Liturgijski vid naputka Ad resurgendum cum Christo

    Get PDF
    This study was funded by the Greenland Bureau of Minerals and Petroleum, the Danish Cooperation of the Environment in the Arctic (DANCEA, Danish Ministry of the Environment) and the Greenland Institute of Natural Resources.Decisions about sustainable exploitation levels of marine resources are often based on inadequate data, but are nevertheless required for practical purposes. We describe one exception where abundance estimates spanning 30 years and catch data spanning more than 40 years were used in a Bayesian assessment model of belugas Delphinapterus leucas off West Greenland. The model was updated with data from a visual aerial survey on the wintering ground in 2012. Methods that take account of stochastic animal availability by using independent estimates of forward and perpendicular sighting distances were used to estimate beluga abundance. A model that appears to be robust to the presence of a few large groups yielded an estimate of 7456 belugas (cv = 0.44), similar to a conventional distance-sampling estimate. A mark–recapture distance analysis that corrects for perception and availability bias estimated the abundance to be 9072 whales (cv = 0.32). Increasing distance of beluga sightings from shore was correlated with decreasing sea ice cover, suggesting that belugas expand their distribution offshore (i.e. westward in this context) with the reduction of coastal sea ice. A model with high (0.98) adult survival estimated a decline from 18 600 (90% CI: 13 400, 26 000) whales in 1970 to 8000 (90% CI: 5830, 11 200) in 2004. The decline was probably a result of a period with exceptionally large catches. Following the introduction of catch limits in 2004, the model projects an increase to 11 600 (90% CI: 6760, 17 600) individuals in 2020 (assuming annual removals of 294 belugas after 2014). If the annual removal level is fixed at 300 individuals, a low-survival (0.97) model predicts a 75% probability of an increasing population during 2015–2020. Reduced removal rates due to catch limits and the more offshore, less accessible distribution of the whales are believed to be responsible for the initial signs of population recovery.Publisher PDFPeer reviewe

    A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions

    Get PDF
    We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10−1 mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer
    corecore