281 research outputs found

    On Proper Polynomial Maps of C2.\mathbb{C}^2.

    Get PDF
    Two proper polynomial maps f1,f2 ⁣:C2C2f_1, f_2 \colon \mathbb{C}^2 \longrightarrow \mathbb{C}^2 are said to be \emph{equivalent} if there exist Φ1,Φ2Aut(C2)\Phi_1, \Phi_2 \in \textrm{Aut}(\mathbb{C}^2) such that f2=Φ2f1Φ1f_2=\Phi_2 \circ f_1 \circ \Phi_1. We investigate proper polynomial maps of arbitrary topological degree d2d \geq 2 up to equivalence. Under the further assumption that the maps are Galois coverings we also provide the complete description of equivalence classes. This widely extends previous results obtained by Lamy in the case d=2d=2.Comment: 15 pages. Final version, to appear in Journal of Geometric Analysi

    1S0 Proton and Neutron Superfluidity in beta-stable Neutron Star Matter

    Get PDF
    We investigate the effect of a microscopic three-body force on the proton and neutron superfluidity in the 1S0^1S_0 channel in β\beta-stable neutron star matter. It is found that the three-body force has only a small effect on the neutron 1S0^1S_0 pairing gap, but it suppresses strongly the proton 1S0^1S_0 superfluidity in β\beta-stable neutron star matter.Comment: 12 pages, 2 figure

    Density dependent hadron field theory for neutron stars with antikaon condensates

    Get PDF
    We investigate KK^- and Kˉ0\bar K^0 condensation in β\beta-equilibrated hyperonic matter within a density dependent hadron field theoretical model. In this model, baryon-baryon and (anti)kaon-baryon interactions are mediated by the exchange of mesons. Density dependent meson-baryon coupling constants are obtained from microscopic Dirac Brueckner calculations using Groningen and Bonn A nucleon-nucleon potential. It is found that the threshold of antikaon condensation is not only sensitive to the equation of state but also to antikaon optical potential depth. Only for large values of antikaon optical potential depth, KK^- condensation sets in even in the presence of negatively charged hyperons. The threshold of Kˉ0\bar K^0 condensation is always reached after KK^- condensation. Antikaon condensation makes the equation of state softer thus resulting in smaller maximum mass stars compared with the case without any condensate.Comment: 20 pages, 7 figures; final version to appear in Physical Review

    Early-stage differentiation between presenile Alzheimer’s disease and frontotemporal dementia using arterial spin labeling MRI

    Get PDF
    Objective: To investigate arterial spin labeling (ASL)-MRI for the early diagnosis of and differentiation between the two most common types of presenile dementia: Alzheimer’s disease (AD) and frontotemporal dementia (FTD), and for distinguishing age-related from pathological perfusion changes. Methods: Thirteen AD and 19 FTD patients, and 25 age-matched older and 22 younger controls underwent 3D pseudo-continuous ASL-MRI at 3 T. Gray matter (GM) volume and cerebral blood flow (CBF), corrected for partial volume effects, were quantified in the entire supratentorial cortex and in 10 GM regions. Sensitivity, specificity and diagnostic performance were evaluated in regions showing significant CBF differences between patient groups or between patients and older controls. Results: AD compared with FTD patients had hypoperfusion in the posterior cingulate cortex,

    Diet-dependent acid load and type 2 diabetes: pooled results from three prospective cohort studie

    Get PDF
    Aims/hypothesis: Studies suggest a potential link between low-grade metabolic acidosis and type 2 diabetes. A western dietary pattern increases daily acid load but the association between diet-dependent acid load and type 2 diabetes is still unclear. This study aimed to assess whether diet-dependent acid load is associated with the risk of type 2 diabetes. Methods: We examined the association between energy-adjusted net endogenous acid production (NEAP), potential renal acid load (PRAL) and animal protein-to-potassium ratio (A:P) on incident type 2 diabetes in 67,433 women from the Nurses’ Health Study, 84,310 women from the Nurses’ Health Study II and 35,743 men from the Health Professionals’ Follow-up Study who were free from type 2 diabetes, cardiovascular disease and cancer at baseline. Study-specific HRs were estimated using Cox proportional hazards models with time-varying covariates and were pooled using a random effects meta-analysis. Results: We documented 15,305 cases of type 2 diabetes during 4,025,131 person-years of follow-up. After adjustment for diabetes risk factors, dietary NEAP, PRAL and A:P were positively associated with type 2 diabetes (pooled HR [95% CI] for highest (Q5) vs lowest quintile (Q1): 1.29 [1.22, 1.37], ptrend <0.0001; 1.29 [1.22, 1.36], ptrend <0.0001 and 1.32 [1.24, 1.40], ptrend <0.0001 for NEAP, PRAL and A:P, respectively). These results were not fully explained by other dietary factors including glycaemic load and dietary quality (HR [95% CI] for Q5 vs Q1: 1.21 [1.09, 1.33], ptrend <0.0001; 1.19 [1.08, 1.30] and 1.26 [1.17, 1.36], ptrend <0.0001 for NEAP, PRAL and A:P, respectively). Conclusions/interpretation: This study suggests that higher diet-dependent acid load is associated with an increased risk of type 2 diabetes. This association is not fully explained by diabetes risk factors and overall diet quality

    Evidence for a mixed mass composition at the `ankle' in the cosmic-ray spectrum

    Get PDF
    We report a first measurement for ultra-high energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid air-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary masses in the cosmic-ray flux. Up till now, constraints on the spread of primary masses have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of air showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the `ankle' at lg(E/eV)=18.519.0\lg(E/{\rm eV})=18.5-19.0 differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with mass A>4A > 4. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavoured as the sole explanation of the ultrahigh-energy cosmic-ray flux at Earth.Comment: Published version. Added journal reference and DOI. Added Report Numbe

    Development and evaluation of a rapid dipstick assay for serodiagnosis of acute human brucellosis

    Get PDF
    A dipstick assay for the detection of brucella-specific immunoglobulin M antibodies was evaluated with 707 sera from 247 laboratory-confirmed brucellosis patients and 342 control sera from brucellosis-free individuals. These sera were collected from six different countries. The assay was found to be highly sensitive and specific. In addition, the test is easy to use and does not require specialized training or equipment, and the components are stable without a requirement for refrigeration. All of these factors make the test ideal for developing countries and rural settings

    Design and implementation of the AMIGA embedded system for data acquisition

    Get PDF
    corecore