2,538 research outputs found
Dark Left-Right Gauge Model: SU(2)_R Phenomenology
In the recently proposed dark left-right gauge model of particle
interactions, the left-handed fermion doublet is connected to its
right-handed counterpart through a scalar bidoublet, but
couples to only through which has no vacuum expectation value.
The usual R parity, i.e. , can be defined for this
nonsupersymmetric model so that both and are odd together with
. The lightest is thus a viable dark-matter candidate (scotino).
Here we explore the phenomenology associated with the gauge group of
this model, which allows it to appear at the TeV energy scale. The exciting
possibility of charged leptons is discussed.Comment: 12 pages, 2 figure
Analyzing library collections with starfield visualizations
This paper presents a qualitative and formative study of the uses of a starfield-based visualization interface for analysis of library collections. The evaluation process has produced feedback that suggests ways to significantly improve starfield interfaces and the interaction process to improve their learnability and usability. The study also gave us clear indication of additional potential uses of starfield visualizations that can be exploited by further functionality and interface development.
We report on resulting implications for the design and use of starfield visualizations that will impact their graphical interface features, their use for managing data quality and their potential for various forms of visual data mining. Although the current implementation and analysis focuses on the collection of a physical library, the most important contributions of our work will be in digital libraries, in which volume, complexity and dynamism of collections are increasing dramatically and tools are needed for visualization and analysis
Experiences with starfield visualizations for analysis of library collections
This paper presents a qualitative and formative study of the uses of a starfield-based visualization interface for analysis of library collections. The evaluation process has produced feedback that suggests ways to significantly improve starfield interfaces and the interaction process to improve their learnability and usability. The study also gave us clear indication of additional potential uses of starfield visualizations that can be exploited by further functionality and interface development. We report on resulting implications for the design and use of starfield visualizations that will impact their graphical interface features, their use for managing data quality and their potential for various forms of visual data mining. Although the current implementation and analysis focuses on the collection of a physical library, the most important contributions of our work will be in digital libraries, in which volume, complexity and dynamism of collections are increasing dramatically and tools are needed for visualization and analysis
Changes in electromyographic activity of latent trigger points after a dry needling intervention: a randomised controlled trial.
Objective
To analyse the effects of dry needling (DN) in upper trapezius latent trigger points (LTrPs) on pressure pain threshold (PPT) and surface electromyography (sEMG).
Design
Randomized, double-blind, placebo controlled clinical trial.
Settings
Sports Rehabilitation Laboratory, University of Castilla-La Mancha.
Participants
Forty-six participants (18–35 years old) with LTrP in the upper trapezius were divided into two groups: DN-group and Sham-DN-group.
Interventions
In the DN-group, the needle was inserted 10-times through the skin, and it was manipulated up and down using a "fast in and out" technique. In the Sham-DN-group, non-penetrating needles were used.
Main outcome measures
PPT, sEMG at rest, and sEMG in isometric contraction of the LTrP of the upper trapezius muscle were evaluated at baseline, 30 min after treatment, and after 24 h, and 72 h of follow-up.
Results
The mean change in sEMG at rest between baseline and 30 min was − 0.38 (0.38) %refRMS for the DN group and − 0.05 (0.31) %refRMS for the Sham-DN group (mean difference −0.34, 95% confidence interval (CI) of the difference: − 0.54 to − 0.13), and between baseline and 24 h was − 0.35 (0.35) %refRMS for the DN group and − 0.06 (0.58) %refRMS for the Sham-DN group (mean difference −0.29, 95% CI: −0.57 to −0.01). In addition, the DN-group showed higher values of PPT than the Sham-DN group at 72 h (5.22 (1.23) to 4.65 (1.03) kg/cm2; p < 0.05).
Conclusions
A single session of DN intervention was effective in reducing the electromyographic activity, muscle fatigue and pain of the upper trapezius muscle in LTrP.pre-print542 K
Chiral and Parity Symmetry Breaking for Planar Fermions: Effects of a Heat Bath and Uniform External Magnetic Field
We study chiral symmetry breaking for relativistic fermions, described by a
parity violating Lagrangian in 2+1-dimensions, in the presence of a heat bath
and a uniform external magnetic field. Working within their four-component
formalism allows for the inclusion of both parity-even and -odd mass terms.
Therefore, we can define two types of fermion anti-fermion condensates. For a
given value of the magnetic field, there exist two different critical
temperatures which would render one of these condensates identically zero,
while the other would survive. Our analysis is completely general: it requires
no particular simplifying hierarchy among the energy scales involved, namely,
bare masses, field strength and temperature. However, we do reproduce some
earlier results, obtained or anticipated in literature, corresponding to
special kinematical regimes for the parity conserving case. Relating the chiral
condensate to the one-loop effective Lagrangian, we also obtain the
magnetization and the pair production rate for different fermion species in a
uniform electric field through the replacement .Comment: 9 pages, 10 figure
A finite strain, finite band method for modeling ductile fracture
We present a finite deformation generalization of the finite thickness embedded discontinuity formulation presented in our previous paper [A.E. Huespe, A. Needleman, J. Oliver, P.J. Sánchez, A finite thickness band method for ductile fracture analysis, Int. J. Plasticity 25 (2009) 2349–2365]. In this framework the transition from a weak discontinuity to a strong discontinuity can occur using a single constitutive relation which is of importance in a range of applications, in particular ductile fracture, where localization typically precedes the creation of new free surface. An embedded weak discontinuity is introduced when the loss of ellipticity condition is met. The resulting localized deformation band is given a specified thickness which introduces a length scale thus providing a regularization of the post-localization response. The methodology is illustrated through several example problems emphasizing finite deformation effects including the development of a cup-cone failure in round bar tension.A.E.H. and P.J.S. are grateful for financial support from ANPCyT and CONICET of Argentina through grants: PICT 2006-01232, PICT 2008-1228 and PIP 112-200901-00341. J.O. is grateful for financial support from the Spanish Ministry of Science and Innovation and the Catalan Government Research Department, under grants BIA2008-00411 and 2009 SGR 1510, respectively.Peer ReviewedPostprint (author's final draft
Carcass and meat quality in light lambs from different fat classes in the EU carcass classification system
Ninety commercial lamb carcasses were analysed according to the four different fat classes in the light lamb European classiffication system. Shoulder fat increased 3%, muscle decreased 2% and bone decreased 1% for each class increase. No signifficant differences were found among fat classes regarding pH, WHC, cooking losses, juiciness, myoglobin content, meat colour measured
immediately after cutting (L*, a*, b*), odour intensity or flavour quality. Some differences were found in colour evolution through
ageing. Shear force decreased and tenderness and flavour intensity increased with fat class but this effect was only signifficant in the
leanest animals
Carcass and meat quality in light lambs from different classes in the European grading system
Fat, quantity and quality, are important aspects for consumers (Sendim et al., 1997), who are more and more interested in healthy products
and usually prefer lean meat and carcasses, although fat is positively associated with acceptability. Thus, Jeremiah (1998) found that the percentage
of unacceptable cuts was higher in lean than fat categories, similar findings being obtained by Paul et al., ( 1964) and Smith et al., (1970). For this
reason practically all carcass classification systems around the world include fatness score as a criterion of quality and price (EEC n° 2 137/92 and
46 1/93 regulations; Moxhan and Brownlie (1976)). Other characteristics such as age, sex, weight, carcass length, meat colour and specially
conformation score are also used, but they have a lower market significance and a lower price influence. Inside the EU there are two different schemes
for lamb classification: one for carcasses up 13 kg and other for light carcasses under 13 kg. In the latter scheme, since Mediterranean carcasses were
systematically penalised because of their natural poor morphology (walker breeds), low subcutaneous/internal fat ratio and light weights,
conformation score is not considered. Only weight (three categories: < 7.0 kg, 7.1-10.0 kg and 10.1-13.0 kg), meat colour and fat class are included
Several studies have shown weak relationships between lamb quality grades and palatability assessments in heavy or medium weight carcasses
(Jeremiah et al., 1972; Crouse and Ferrel, I 982), but there has been no investigation of this relationship in light lambs. On the other hand, it seems
essential to know if any classification is, or is not, related with real carcass value and quality
Efficient HIV-1 inhibition by a 16 nt-long RNA aptamer designed by combining in vitro selection and in silico optimisation strategies
The human immunodeficiency virus type-1 (HIV-1) genome contains multiple, highly conserved structural RNA domains that play key roles in essential viral processes. Interference with the function of these RNA domains either by disrupting their structures or by blocking their interaction with viral or cellular factors may seriously compromise HIV-1 viability. RNA aptamers are amongst the most promising synthetic molecules able to interact with structural domains of viral genomes. However, aptamer shortening up to their minimal active domain is usually necessary for scaling up production, what requires very time-consuming, trial-and-error approaches. Here we report on the in vitro selection of 64 nt-long specific aptamers against the complete 5' -untranslated region of HIV-1 genome, which inhibit more than 75% of HIV-1 production in a human cell line. The analysis of the selected sequences and structures allowed for the identification of a highly conserved 16 nt-long stem-loop motif containing a common 8 nt-long apical loop. Based on this result, an in silico designed 16 nt-long RNA aptamer, termed RNApt16, was synthesized, with sequence 5'-CCCCGGCAAGGAGGGG-3-'. The HIV-1 inhibition efficiency of such an aptamer was close to 85%, thus constituting the shortest RNA molecule so far described that efficiently interferes with HIV-1 replication
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