415 research outputs found
Gluino Stransverse Mass
We introduce a new observable, 'gluino stransverse mass', which is an
application of the Cambridge variable to the process where gluinos are
pair produced in proton-proton collision and each gluino subsequently decays
into two quarks and one LSP, $i.e. \tilde{g}\tilde{g} \to qq\tilde\chi_1^0\
qq\tilde\chi_1^0$. We show that the gluino stransverse mass can be utilized to
measure the gluino and the lightest neutralino masses separately, and also the
(1st and 2nd generation) squark masses if lighter than the gluino mass, thereby
providing a good first look at the pattern of sparticle masses experimentally.Comment: Typos corrected, Some discussions and one reference adde
M_T2-assisted on-shell reconstruction of missing momenta and its application to spin measurement at the LHC
We propose a scheme to assign a 4-momentum to each WIMP in new physics event
producing a pair of mother particles each of which decays to an invisible
weakly interacting massive particle (WIMP) plus some visible particle(s). The
transverse components are given by the value that determines the event variable
M_T2, while the longitudinal component is determined by the on-shell condition
on the mother particle. Although it does not give the true WIMP momentum in
general, this M_T2-assisted on-shell reconstruction of missing momenta provides
kinematic variables well correlated to the true WIMP momentum, and thus can be
useful for an experimental determination of new particle properties. We apply
this scheme to some processes to measure the mother particle spin, and find
that spin determination is possible even without a good knowledge of the new
particle masses.Comment: 11 pages, 10 figures, typos are corrected, figures are replace
Measuring the top quark mass with m_T2 at the LHC
We investigate the possibility to measure the top quark mass using the
collider variable at the LHC experiment. Monte Carlo studies of
are performed with the events corresponding to the dilepton decays of
produced at the LHC with 10 integrated luminosity. Our
analysis suggests that the top quark mass can be determined by the
variable alone with a good precision at the level of 1 GeV.Comment: 10 pages, 4 figure
Application and evaluation of the MLVA typing assay for the Brucella abortus strains isolated in Korea
<p>Abstract</p> <p>Background</p> <p>A Brucella eradication program has been executed in Korea. To effectively prevent and control brucellosis, a molecular method for genetic identification and epidemiological trace-back must be established. As part of that, the MLVA typing assay was evaluated and applied to <it>B. abortus </it>isolates for analyzing the characteristics of the regional distribution and relationships of foreign isolates.</p> <p>Results</p> <p>A total of 177 isolates originating from 105 cattle farms for the period 1996 to 2008 were selected as representatives for the nine provinces of South Korea. A dendrogram of strain relatedness was constructed in accordance with the number of tandem repeat units for 17 loci so that it was possible to trace back in the restricted areas. Even in a farm contaminated by one source, however, the <it>Brucella </it>isolates showed an increase or decrease in one TRs copy number at some loci with high DI values. Moreover, those 17 loci was confirmed in stability via <it>in-vitro </it>and <it>in-vivo </it>passage, and found to be sufficiently stable markers that can readily identify the inoculated strain even if minor changes were detected. In the parsimony analysis with foreign <it>Brucella </it>isolates, domestic isolates were clustered distinctively, and located near the Central and Southern American isolates.</p> <p>Conclusion</p> <p>The MLVA assay has enough discrimination power in the <it>Brucella </it>species level and can be utilized as a tool for the epidemiological trace-back of the <it>B. abortus </it>isolates. But it is important to consider that <it>Brucella </it>isolates may be capable of undergoing minor changes at some loci in the course of infection or in accordance with the changes of the host.</p
Controlled manipulation of oxygen vacancies using nanoscale flexoelectricity
Oxygen vacancies, especially their distribution, are directly coupled to the
electromagnetic properties of oxides and related emergent functionalities that
have implication in device applications. Here using a homoepitaxial strontium
titanate thin film, we demonstrate a controlled manipulation of the oxygen
vacancy distribution using the mechanical force from a scanning probe
microscope tip. By combining Kelvin probe force microscopy imaging and
phase-field simulations, we show that oxygen vacancies can move under a
stress-gradient-induced depolarisation field. When tailored, this nanoscale
flexoelectric effect enables a controlled spatial modulation. In motion, the
scanning probe tip thereby deterministically reconfigures the spatial
distribution of vacancies. The ability to locally manipulate oxygen vacancies
on-demand provides a tool for the exploration of mesoscale quantum phenomena,
and engineering multifunctional oxide devices.Comment: 35 pages, Main text and the supplementary information combine
Hemodynamically balanced congenitally corrected transposition of the great arteries with a large ventricular septal defect, and subvalvular pulmonic stenosis: a case report
Background
Adults with unoperated congenitally corrected transposition of the great arteries are rare but form a distinct group among adults with congenital heart disease. Patients with congenitally corrected transposition of the great arteries often have one or more associated cardiac anomalies that dictate the need for, and timing of, surgical intervention in childhood. However, in a proportion of patients, the hemodynamics does not require surgical attention during childhood, and, in some patients, a correct diagnosis is not established until adulthood. Here we report an adult case of unoperated congenitally corrected transposition of the great arteries with a large ventricular septal defect and probable pulmonary arterial hypertension.
Case presentation
Our patient was a 46-year-old Korean man. Transthoracic echocardiography and cardiac catheterization demonstrated hemodynamically balanced ventricles with a non-regurgitant systemic atrioventricular valve, normal pulmonary arterial pressure, and a reasonable difference between the oxygen saturation values of the aorta and pulmonary trunk, even with the presence of a large ventricular septal defect. Further morphological assessments using cardiac computed tomography and three-dimensional modeling/printing of his heart revealed that the mitral valve was straddling over the posteriorly positioned ventricular septal defect, which could explain the functional and anatomical subvalvular pulmonary stenosis and a small amount of shunt flow through the large ventricular septal defect. We interpreted this combination of cardiac defects as able to sustain his stable cardiac function. Thus, we decided to maintain his unoperated status.
Conclusion
A detailed anatomical understanding based on transthoracic echocardiography, cardiac computed tomography, and three-dimensional printing can justify a decision to not operate in cases of congenitally corrected transposition of the great arteries with hemodynamically balanced pulmonary stenosis and a ventricular septal defect, as observed in the present case
Longitudinal relationship between depression and antisocial behaviors in Korean adolescents
BackgroundIt is well known that depression and delinquency in adolescents are highly correlated, but longitudinal studies on the causal relationship between them are not active in East Asia compared to in Western culture. In addition, even the results of research on causal models and sex differences are inconsistent.ObjectivesThis study examines the longitudinal reciprocal effects between depression and delinquent behavior in Korean adolescents based on sex differences.MethodsWe conducted multiple-group analysis by using an autoregressive cross-lagged model (ACLM). Longitudinal data from 2,075 individuals (2011â2013) were used for analysis. The longitudinal data are from the Korean Children and Youth Panel Survey (KCYPS), and data were used beginning with students at 14âyears old (in the second grade of middle school) and tracked them until they were 16 (in the first grade of high school).ResultsBoysâ delinquent behaviors at 15âyears (the third grade of middle school) affected their depression at 16âyears (the first grade of high school). In contrast, girlsâ depression at 15âyears (the third grade of middle school) influenced their delinquent behaviors at 16âyears (the first grade of high school).DiscussionThe findings support the failure model (FM) among adolescent boys and the acting-out model (ACM) among girls. The results imply that strategies to effectively prevent and treat delinquency and depression in adolescents must consider sex effects
CT-Guided Percutaneous Vertebroplasty in the Treatment of an Upper Thoracic Compression Fracture
Percutaneous vertebroplasty (PVP) has been used to relieve pain and to prevent further collapse of the vertebral body in patients with an osteoporotic compression fracture. The most commonly affected site for the use of PVP is the thoracolumbar junction. There are few reports that have described on the usefulness of PVP in the treatment of a high thoracic compression fracture. We report a case of an upper thoracic compression fracture that was treated with computed tomography (CT)-guided PVP. It was possible to obtain easy access to the narrow thoracic pedicle and it was also possible to monitor continuously the proper volume of polymethylmethacrylate employed, under CT guidance
LHC Signature of Mirage Mediation
We study LHC phenomenology of mirage mediation scenario in which anomaly and
modulus contributions to soft SUSY breaking terms are comparable to each other.
A Monte Carlo study of mirage mediation, with model parameters , GeV, , and , is presented. It is
shown that masses of supersymmetric particles can be measured in a model
independent way, providing information on SUSY breaking sector. In particular,
the mass ratio of gluino to the lightest neutralino for the benchmark scenario
is determined to be 1.9 \lesssim m_{\tildeg}/m_{\tilde\chi_1^0} \lesssim 3.1,
well reproducing theoretical input value of which is quite distinctive from the predictions of other SUSY scenarios in which gaugino
masses are unified at the GUT scale. The model parameters of mirage mediation
can be also determined from various kinematic distributions
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