Validation of a high resolution version of the regional climate model RegCM3 over the Carpathian Basin

This paper presents a validation study for a high-resolution version of the Regional Climate Model version 3 (RegCM3) over the Carpathian basin and its surroundings. The horizontal grid spacing of the model is 10 km—the highest reached by RegCM3. The ability of the model to capture temporal and spatial variability of temperature and precipitation over the region of interest is evaluated using metrics spanning a wide range of temporal (daily to climatology) and spatial (inner domain average to local) scales against different observational datasets. The simulated period is 1961–90. RegCM3 shows small temperature biases but a general overestimation of precipitation, especially in winter; although, this overestimate may be artificially enhanced by uncertainties in observations. The precipitation bias over the Hungarian territory, the authors’ main area of interest, is mostly less than 20%. The model captures well the observed late twentieth-century decadal-to-interannual and interseasonal variability. On short time scales, simulated daily temperature and precipitation show a high correlation with observations, with a correlation coefficient of 0.9 for temperature and 0.6 for precipitation. Comparison with two Hungarian station time series shows that the model performance does not degrade when going to the 10-km gridpoint scale. Finally, the model reproduces the spatial distribution of dry and wet spells over the region. Overall, it is assessed that this high-resolution version of RegCM3 is of sufficiently good quality to perform climate change experiments over the Carpathian region—and, in particular, the Hungarian territory—for application to impact and adaptation studies

Infrared behavior of graviton-graviton scattering

The quantum effective theory of general relativity, independent of the eventual full theory at high energy, expresses graviton-graviton scattering at one loop order O(E^4) with only one parameter, Newton's constant. Dunbar and Norridge have calculated the one loop amplitude using string based techniques. We complete the calculation by showing that the 1/(d-4) divergence which remains in their result comes from the infrared sector and that the cross section is finite and model independent when the usual bremsstrahlung diagrams are included.Comment: 12 pages, uses axodra

Symmetry breaking via fermion 4-point functions

We construct the effective action and gap equations for nonperturbative fermion 4-point functions. Our results apply to situations in which fermion masses can be ignored, which is the case for theories of strong flavor interactions involving standard quarks and leptons above the electroweak scale. The structure of the gap equations is different from what a naive generalization of the 2-point case would suggest, and we find for example that gauge exchanges are insufficient to generate nonperturbative 4-point functions when the number of colors is large.Comment: 36 pages, uses Revtex and eps files for figure

The reactions \gwl\ and \gzl\ in SU(N)SU(N) strongly interacting theories

Building on recent phenomenology of \gpi, we discuss the expectation for two photon production of longitudinal gauge boson pairs in $SU(N)$ technicolor theories. The treatment involves a matching of dispersive techniques with the methodology of chiral perturbation theory.Comment: 25 LaTeX pages (incl. 10 figures on 7 pages, also in plain LaTeX, also available from the authors in PostScript form via regular E_mail), UMHEP-39

Результаты симультанных операций у пациентов с атеросклеротическим поражением сонных и коронарных артерий

СОННЫЕ АРТЕРИИАТЕРОСКЛЕРОЗАРТЕРИОСКЛЕРОЗКОРОНАРНЫХ АРТЕРИЙ СТЕНОЗКАРОТИДНАЯ ЭНДАРТЕРЭКТОМИЯСОННОЙ АРТЕРИИ ЭНДАРТЕРЭКТОМИЯСТЕНОКАРДИЯАОРТОКОРОНАРНОЕ ШУНТИРОВАНИЕКОРОНАРНОЙ АРТЕРИИ ШУНТИРОВАНИ

A candidate liquid chromatography mass spectrometry reference method for the quantification of the cardiac marker 1-32 B-type natriuretic peptide

B-type natriuretic peptide (BNP) is a 32 amino acid cardiac hormone routinely measured by immunoassays to diagnose heart failure. While it is reported that immunoassay results can vary up to 45%, no attempt of standardization and/or harmonization through the development of certified reference materials (CRMs) or reference measurement procedures (RMPs) has yet been carried out. B-type natriuretic peptide primary calibrator was quantified traceably to the International System of Units (SI) by both amino acid analysis and tryptic digestion. A method for the stabilization of BNP in plasma followed by protein precipitation, solid phase extraction (SPE) and liquid chromatography (LC) mass spectrometry (MS) was then developed and validated for the quantification of BNP at clinically relevant concentrations (15-150 fmol/g). The candidate reference method was applied to the quantification of BNP in a number of samples from the UK NEQAS Cardiac Markers Scheme to demonstrate its applicability to generate reference values and to preliminary evaluate the commutability of a potential CRM. The results from the reference method were consistently lower than the immunoassay results and discrepancy between the immunoassays was observed confirming previous data. The application of the liquid chromatography-mass spectrometry (LC-MS) method to the UK NEQAS samples and the correlation of the results with the immunoassay results shows the potential of the method to support external quality assessment schemes, to improve understanding of the bias of the assays and to establish RMPs for BNP measurements. Furthermore, the method has the potential to be multiplexed for monitoring circulating truncated forms of BNP

Recent increases in winter snowfall provide resilience to very small glaciers in the Julian Alps, Europe

Very small glaciers (<0.5 km2) account for more than 80% of the total number of glaciers and more than 15% of the total glacier area in the European Alps. This study seeks to better understand the impact of extreme snowfall events on the resilience of very small glaciers and ice patches in the southeastern European Alps, an area with the highest mean annual precipitation in the entire Alpine chain. Mean annual precipitation here is up to 3300 mm water equivalent, and the winter snow accumulation is approximately 6.80 m at 1800 m asl averaged over the period 1979–2018. As a consequence, very small glaciers and ice/firn patches are still present in this area at rather low altitudes (1830–2340 m). We performed repeated geodetic mass balance measurements on 14 ice bodies during the period 2006–2018 and the results show an increase greater than 10% increase in ice volume over this period. This is in accordance with several extreme winter snow accumulations in the 2000s, promoting a positive mass balance in the following years. The long-term evolution of these very small glaciers and ice bodies matches well with changes in mean temperature of the ablation season linked to variability of Atlantic Multidecadal Oscillation. Nevertheless, the recent behaviour of such residual ice masses in this area where orographic precipitation represents an important component of weather amplification is somehow different to most of the Alps. We analysed synoptic meteorological conditions leading to the exceptional snowy winters in the 2000s, which appear to be related to the influence and modification of atmospheric planetary waves and Arctic Amplification, with further positive feedbacks due to change in local sea surface temperature and its interactions with low level flows and the orography. Although further summer warming is expected in the next decades, we conclude that modification of storm tracks and more frequent occurrence of extreme snowfall events during winter are crucial in ensuring the resilience of small glacial remnants in maritime alpine sectors

On the power counting of loop diagrams in general relativity

A class of loop diagrams in general relativity appears to have a behavior which would upset the utility of the energy expansion for quantum effects. We show through the study of specific diagrams that cancellations occur which restore the expected behaviour of the energy expansion. By considering the power counting in a physical gauge we show that the apparent bad behavior is a gauge artifact, and that the quantum loops enter with a well behaved energy expansion.Comment: 29 pages, uses axodraw and epsfig.tex, one small .eps file is included. The full PostScript version is also available as http://het.phast.umass.edu/students/kakukk/powercount_hepth.p

New physics in ttbar spin correlations at the Tevatron

We show that the angular distributions of leptons or jets due to ttbar spin correlations allow a determination of the top chromomagnetic moment kappa with an accuracy of order 0.1. The method is quite insensitive to background, event reconstruction, and other experimental uncertainties. The total event number is important, so we suggest the inclusion of all-hadronic events.Comment: 13 pages, 3 figures, two references added and cosmetic change