759 research outputs found
CERN LHC sensitivity to the resonance spectrum of a minimal strongly interacting electroweak symmetry breaking sector
We present a unified analysis of the two main production processes of vector boson pairs at the CERN LHC, VV-fusion and qq annihilation, in a minimal strongly interacting electroweak symmetry breaking sector. Using a unitarized electroweak chiral Lagrangian formalism and modeling the final V L V L strong rescattering effects by a form factor, we describe qq annihilation processes in terms of the two chiral parameters that govern elastic V L V L scattering. Depending on the values of these two chiral parameters, the unitarized amplitudes may present resonant enhancements in different angular momentum-isospin channels. Scanning this two parameter space, we generate the general resonance spectrum of a minimal strongly interacting electroweak symmetry breaking sector and determine the regions that can be probed at the CERN LHC
Large wood transport as significant influence on flood risk in a mountain village
An important issue that is not considered in most flood risk assessments in mountain villages in Spain is the transport of solids associated with the flood flow, in this case, large wood transport. The transport and deposition of this wood in urban areas may be a potentially worse hazard than the flood flow itself. Despite its importance, large wood is a key ecological element in rivers, so removing it could be an unsuccessful approach. Therefore, efforts are needed in the better understanding of wood transport and deposition in streams. To analyse this process, scenario-based 2D hydrodynamic flood modelling was carried out. Since flood risk assessment has considerable intrinsic uncertainty, probabilistic thinking was complemented by possibilistic thinking, considering worst-case scenarios. This procedure obtained a probabilistic flood map for a 500-year return period. Then, a series of scenarios was built based on wood budget to simulate wood transport and deposition. Results allowed us to identify the main infrastructures sensitive to the passing of large wood and simulate the consequences of their blockage due to wood. The potential damage was estimated as well as the preliminary social vulnerability for all scenarios (with and without wood transport). This work shows that wood transport and deposition during flooding may increase potential damage at critical stream configurations (bridges) by up to 50% and the number of potentially exposed people nearby these areas by up to 35%
Pathological and virological findings in patients with persistent hypertransaminasaemia of unknown aetiology
BACKGROUND: The histopathological spectrum and role of hepatitis viruses in cases of hypertransaminasaemia of unknown aetiology have not been correctly analysed in a sufficiently large number of patients.
METHODS: We studied 1075 consecutive patients referred for liver biopsy because of elevation of alanine aminotransferase (ALT) levels for more than six months. From this population we selected those cases in whom the aetiology could not be defined from clinical, biochemical, and serological data obtained before biopsy. In these patients liver biopsies were reviewed, and hepatitis B virus (HBV)-DNA and hepatitis C virus (HCV)-RNA were assayed in serum by polymerase chain reaction (PCR). Serum hepatitis G virus (HGV)-RNA was determined by PCR in 74 patients.
RESULTS: Of 1075 patients studied, the cause of the increased serum ALT levels remained elusive after appropriate testing in 109 patients (10.1%). Liver biopsies from these patients showed non-specific changes in 32.7% of cases, non-alcoholic steatohepatitis (NASH) in 15.8%, and chronic hepatitis or cirrhosis in 51.5%. HBV-DNA and/or HCV-RNA was detected more frequently in cryptogenic liver disease than in healthy blood donors (26.7% v 3.4%; p<0.001). HGV-RNA was found in only one patient. The proportion of cases with detectable HBV-DNA or HCV-RNA was 14.3% in patients with non-specific changes or NASH, 30.7% in patients with chronic hepatitis, and 61.5% in patients with cirrhosis. Cirrhosis was found more frequently in patients with positive HBV-DNA and/or HCV-RNA in serum than in those who tested negatively (p=0.005).
CONCLUSIONS: In our series, patients in whom biochemical and serological data did not determine the aetiology of the disease represented 10% of all cases referred for liver biopsy for persistent elevation of serum transaminases. Approximately 50% of patients had chronic hepatitis or cirrhosis and the remainder had NASH or non-specific changes. Occult viral infections were found in a high proportion of cases in the first group and in a low percentage of patients in the second
NICMOS Imaging of Molecular Hydrogen Emission in Seyfert Galaxies
We present NICMOS imaging of broad band and molecular hydrogen emission in
Seyfert galaxies. In 6 of 10 Seyferts we detect resolved or extended emission
in the 1-0 S(1) 2.121 or 1-0 S(3) 1.9570 micron molecular hydrogen lines. We
did not detect emission in the most distant galaxy or in the 2 Seyfert 1
galaxies in our sample because of the luminosity of the nuclear point sources.
In NGC 5643, NGC 2110 and MKN 1066, molecular hydrogen emission is detected in
the extended narrow line region on scales of a few hundred pc from the nucleus.
Emission is coincident with [OIII] and H alpha+[NII] line emission. This
emission is also near dust lanes observed in the visible to near-infrared color
maps suggesting that a multiphase medium exists near the ionization cones and
that the morphology of the line emission is dependent on the density of the
ambient media. The high 1-0 S(1) or S(3) H2 to H alpha flux ratio suggests that
shock excitation of molecular hydrogen (rather than UV fluorescence) is the
dominant excitation process in these extended features. In NGC 2992 and NGC
3227 the molecular hydrogen emission is from 800 and 100 pc diameter `disks'
(respectively) which are not directly associated with [OIII] emission and are
near high levels of extinction (AV > 10). In NGC 4945 the molecular hydrogen
emission appears to be from the edge of a 100 pc superbubble. In these 3
galaxies the molecular gas could be excited by processes associated with local
star formation. We confirm previous spectroscopic studies finding that no
single mechanism is likely to be responsible for the molecular hydrogen
excitation in Seyfert galaxies.Comment: submitted to Ap
The Electroweak Chiral Lagrangian for the Standard Model with a Heavy Higgs
The most general chiral Lagrangian for electroweak interactions with the
complete set of invariant operators up to dimension four
is considered. The two-point and three-point functions with external gauge
fields are derived from this effective chiral Lagrangian to one-loop order in a
generic -gauge. The same set of Green's functions are paralelly studied
in the renormalizable standard model to one-loop order, in a -gauge and
in the large Higgs mass limit. An appropriate set of matching conditions
connecting the Green's functions of the two theories allows us to derive,
systematically, the values of the chiral Lagrangian coefficients corresponding
to the large Higgs mass limit of the standard model. These chiral parameters
represent the non-decoupling effects of a heavy Higgs particle and incorporate
both the leading logarithmic dependence on \mh and the next to leading
constant contributions. Some phenomenological implications are also discussed.Comment: pg.23, LaTeX, 3 figures (not included), FTUAM-93/2
Supervision multidistribuida de un secadero solar de madera empleando sensores de bajo coste
Multi-distributed supervision of wood in solar dryers is carried out by means of high performance low cost ambient sensors. An experimental dryer of 0.3 m 3 is used for testing the proposed instrumentation mainly based on thermocouples and SENSIRION TM which are combined with the psychometric model defined by ASABE in order to assess the amount of water released by the wood during the drying process. Continuous monitoring enables the Implementation of automated control of the dryer by means of regulating the fan speed and the amount of re-circulated air
The impact of a web-based lifestyle educational program (‘Living Better’) Reintervention on hypertensive overweight or obese patients
‘Living Better’, a self-administered web-based intervention, designed to facilitate lifestyle changes, has already shown positive short-and medium-term health benefits in patients with an obesity–hypertension phenotype. The objectives of this study were: (1) to examine the long-term (3-year) evolution of a group of hypertensive overweight or obese patients who had already followed the ‘Living Better’ program; (2) to analyze the effects of completing this program a second time (reintervention) during the COVID-19 pandemic. A quasi-experimental design was used. We recruited 29 individuals from the 105 who had participated in our first study. We assessed and compared their systolic and diastolic blood pressure (SBP and DBP), body mass index (BMI), eating behavior, and physical activity (PA) level (reported as METs-min/week), at Time 0 (first intervention follow-up), Time 1 (before the reintervention), and Time 2 (post-reintervention). Our results showed significant improvements between Time 1 and Time 2 in SBP (-4.7 (-8.7 to -0.7); p = 0.017), DBP (-3.5 (-6.2 to -0.8); p = 0.009), BMI (-0.7 (-1.0 to -0.4); p 0.24). Implementation of the ‘Living Better’ program maintained positive long-term (3-year) health benefits in patients with an obesity–hypertension phenotype. Moreover, a reintervention with this program during the COVID-19 pandemic produced significant improvements in blood pressure, BMI, eating behavior, and PA. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
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