3,402 research outputs found
Improved analysis of the bounds from the electroweak precision tests on the 4-site model
We present a new complete analysis of the electroweak precision observables
within the recently proposed 4-site Higgsless model, which is based on the
SU(2)_L x SU(2)_1 x SU(2)_2 x U(1)_Y gauge symmetry and predicts six extra
gauge bosons, W_{1,2} and Z_{1,2}. Within the epsilon_i (i=1,2,3,b)
parametrization, we compute for the first time the EWPT bounds via a complete
numerical algorithm going beyond commonly used approximations. Both
epsilon_{1,3} impose strong constraints. Hence, it is mandatory to consider
them jointly when extracting EWPT bounds and to fully take in to account the
correlations among the electroweak precison measurements. The phenomenological
consequence is that the extra gauge bosons must be heavier than 250 GeV. Their
couplings to SM fermions, even if bounded, might be of the same order of
magnitude than the SM ones. In contrast to other Higgsless models, the 4-site
model is not fermiophobic. The new gauge bosons could thus be discovered in the
favoured Drell-Yan channel already during the present run of the LHC
experiment.Comment: Latex file, 35 pages, 10 figures, corrected typos, published versio
Interference effects in heavy W'-boson searches at the LHC
Interference effects are widely neglected in searches for new physics. This
is the case in recent publications on searches for W'-bosons using leptonic
final states.
We examine the effects of interference on distributions frequently used to
determine mass limits for possible W'-bosons and show that there are important
qualitative effects on the behaviour of the new physics signal.
There are two main consequences. Firstly, exclusion limits where
interferences effects have not been considered are likely to have been
overestimated. Secondly, presenting experimental results as a function of a
transverse mass cut rather than in terms of the contribution of new physics to
the total cross-section would be more informative.Comment: 31 pages, 8 figures. Published versio
Morpheme-based reading aloud: Evidence from dyslexic and skilled Italian readers
The role of morphology in reading aloud was examined measuring naming latencies to pseudowords and words composed of morphemes (roots and derivational suffixes) and corresponding simple pseudowords and words. Three groups of Italian children of different ages and reading abilities, including dyslexic children, as well as one group of adult readers participated in the study. All four groups read faster and more accurately pseudowords composed of root and suffix than simple pseudowords (Experiment 1). Unlike skilled young and adult readers, both dyslexics and younger children benefited from morphological structure also in reading aloud words (Experiment 2). It is proposed that the morpheme is a unit of intermediate grain size that proves useful in processing all linguistic stimuli, including words, in individuals with limited reading ability (dyslexics and younger readers) who did not fully develop mastering of whole-word processing. For skilled readers, morphemic parsing is useful for reading those stimuli (i.e., pseudowords made up of morphemes), for which a whole-word lexical unit does not exist; where such whole-word lexical units do exist, skilled readers do not need to rely on morphological parsing because they can rely on a lexical (whole-word) reading unit that is larger than the morpheme. (C) 2008 Elsevier B.V. All rights reserved
Thio-conjugation of substituted benzofurazans to peptides: molecular sieves catalyze nucleophilic attack on unsaturated fused rings
Bioconjugates of 2,1,3-benzoxadiazole (benzofurazan) and its derivatives have attracted considerable
interest due to their biological activities and applications as fluorescent tags. A high-yield, chemoselective,
and mild procedure for the S-alkylation of cysteine containing peptides by benzofurazan halogenides is
reported. The key feature of this procedure is the use of activated molecular sieves (MS) to catalyze thiol
activation for nucleophilic substitution under very mild conditions (room temperature and no need for
added bases). To the best of our knowledge, this is the first report about thiol nucleophilic substitution
performed on unsaturated and annelated systems catalyzed by activated molecular sieves. Reaction yields
were remarkable even with benzofurazans having weakly activating groups or no activating groups at all.
The potential of the new methodology was explored by synthesizing fluorescent, hydrophilic
benzofurazan/peptide conjugates, also with peptides containing unprotected lysine residues
Advances in irrigation management in greenhouse cultivation
The advantages of greenhouse include the ability to secure better conditions than outdoor environment for crop growth and development, increased off-season production and autonomy from external weather conditions. This chapter provides an up-to-date critical overview of scientific advances in irrigation management for greenhouse vegetables and ornamentals. The chapter presents a technical design of a typical greenhouse irrigation system, before covering water balance and crop evapotranspiration techniques as well as the use of high-tech moisture sensors for irrigation scheduling. In the context of enhancing the water use efficiency of greenhouse crops, the chapter also discusses innovative management practices such as biostimulants and grafting. Finally, the chapter concludes by looking ahead to future prospects and research breakthroughs
Insights from computational modeling on the potential hemodynamic effects of sinus rhythm versus atrial fibrillation
Atrial fibrillation (AF) is the most common clinical tachyarrhythmia, posing a
significant burden to patients, physicians, and healthcare systems worldwide.
With the advent of more effective rhythm control strategies, such as
AF catheter ablation, an early rhythm control strategy is progressively
demonstrating its superiority not only in symptoms control but also in
prognostic terms, over a standard strategy (rate control, with rhythm control
reserved only to patients with refractory symptoms). This review summarizes
the different impacts exerted by AF on heart mechanics and systemic
circulation, as well as on cerebral and coronary vascular beds, providing
computational modeling-based hemodynamic insights in favor of pursuing
sinus rhythm maintenance in AF patients
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