404 research outputs found
Selective lactase deficiency is common in pediatric patients undergoing upper endoscopy
Lactase deficiency can lead to significant symptoms in the pediatric population. To date, few studies have examined the prevalence of enzyme testing-based lactase and other disaccharidase deficiencies (DDs) in pediatric patients undergoing upper endoscopic evaluation. The primary objective of this study was to determine the prevalence of selective lactase and other DDs amongst a large cohort of pediatric patients with and without inflammatory bowel disease (IBD: Crohn’s disease and ulcerative colitis) via a chart review of 739 patients who underwent esophago-gastro-dudenoscopy EGD between April 2010 and August 2016. We identified 560 pediatric patients (ages 1-18 years) who underwent mucosal enzyme testing at the time of their EGD. The overall rate of lactase deficiency (LD) was 39%. LD positively correlated with age (p=0.00017), but there was no significant difference between age matched IBD and non-IBD patients (45% vs. 42% p=0.68). Four patients (0.17%) were found to have selective maltase deficiency. No selective sucrase or palatinase deficiency was identified. Statistically significant differences occurred in lactase deficiency amongst patients of different races. In conclusion, lactase deficiency is a relatively common finding in children undergoing EGD though at no increased rate amongst the IBD patient population. Disaccharidase testing should be considered in pediatric patients undergoing EGD
Flotation Studies on Low Grade Magnesite Deposits from Sujikonda near Daroji Bellary district, Karnataka State
Magnesite, an important basic refractory raw material, has been in short supply in recent years. To find an alte-rnative to high costlow boron containing sea water magne-site, users have been looking more towards sources of a natural magnesite. Magnesite ( MgCO3 ) is commonly found in granular, compact earthy masses occurring as amorphous
or crystalline deposits. The amorphous type of deposits are the most common variety found as veins in serpentine rocks. The low grade ores produced do not meet the chemical
purity required by the consuming industries (Table-1). The low grade ores have to be upgraded by physical benefi-ciation methods to render them usable, besides, conserving high grade reserves of magnesite. in view of the proposed Vijayanagara steel plant in Toranagallu, the occurrence of Sujikonda magnesite deposit close to the steel plant attains greater significance. The magnesite deposit of Sujikonda area is of low grade with MgO = 29:60 wt.% ;
Ca0 = 5.61 wt. %; Si02 = 3.84 wt. %; and R2 03 = 31.04 wt. %. In the present investigation the authors carried out experiments to understand the flotation behaviour of low grade magnesite
Collider Signature of Bulk Neutrinos in Large Extra Dimensions
We consider the collider signature of right-handed neutrinos propagating in
(large) extra dimensions, and interacting with Standard Model fields
only through a Yukawa coupling to the left-handed neutrino and the Higgs boson.
These theories are attractive as they can explain the smallness of the neutrino
mass, as has already been shown. We show that if is bigger than two,
it can result in an enhancement in the production rate of the Higgs boson,
decaying either invisibly or to a anti- quark pair, associated with an
isolated high charged lepton and missing transverse energy at future
hadron colliders, such as the LHC. The enhancement is due to the large number
of Kaluza-Klein neutrinos produced in the final state. The observation of the
signal event would provide an opportunity to distinguish between the normal and
inverted neutrino mass hierarchies, and to determine the absolute scale of
neutrino masses by measuring the asymmetry of the observed event numbers in the
electron and muon channels.Comment: 31 pages, 13 figures. v2: Added discussion on PDF uncertainties,
added reference
A clean signal for a top-like isosinglet fermion at the Large Hadron Collider
We predict a clean signal at the Large Hadron Collider (=14 TeV for
a scenario where there is a top-like, charge +2/3 vectorlike isosinglet
fermion. Such a quark, via mixing with the standard model top, can undergo
decays via both flavour-changing Z-boson coupling and flavour-changing Yukawa
interactions. We concentrate on the latter channel, and study the situation
where, following its pair-production, the heavy quark pair gives rise to two
tops and two Higgs boson. We show that the case where each Higgs decays in the
channel, there can be a rather distinct and background-free signal
that can unveil the existence of the vectorlike isosinglet quark of this kind.Comment: 14 pages, 5 figures, 4 table
New Physics at the LHC. A Les Houches Report: Physics at TeV Colliders 2009 - New Physics Working Group
We present a collection of signatures for physics beyond the standard model
that need to be explored at the LHC. First, are presented various tools
developed to measure new particle masses in scenarios where all decays include
an unobservable particle. Second, various aspects of supersymmetric models are
discussed. Third, some signatures of models of strong electroweak symmetry are
discussed. In the fourth part, a special attention is devoted to high mass
resonances, as the ones appearing in models with warped extra dimensions.
Finally, prospects for models with a hidden sector/valley are presented. Our
report, which includes brief experimental and theoretical reviews as well as
original results, summarizes the activities of the "New Physics" working group
for the "Physics at TeV Colliders" workshop (Les Houches, France, 8-26 June,
2009).Comment: 189 page
Cosmic rays from Leptonic Dark Matter
If dark matter possesses a lepton number, it is natural to expect the
dark-matter annihilation and/or decay mainly produces the standard model
leptons, while negligible amount of the antiproton is produced. To illustrate
such a simple idea, we consider a scenario that a right-handed sneutrino dark
matter decays into the standard model particles through tiny R-parity violating
interactions. Interestingly enough, charged leptons as well as neutrinos are
directly produced, and they can lead to a sharp peak in the predicted positron
fraction. Moreover, the decay of the right-handed sneutrino also generates
diffuse continuum gamma rays which may account for the excess observed by
EGRET, while the primary antiproton flux can be suppressed. Those predictions
on the cosmic-ray fluxes of the positrons, gamma rays and antiprotons will be
tested by the PAMELA and FGST observatories.Comment: 21 pages, 4 figures, 2 tables, updated plots including PAMELA dat
SmartEx: a case study on user profiling and adaptation in exhibition booths
An investigation into user profiling and adaptation with exhibition booth as a case study is reported. First a review of the field of exhibitions and trade fairs and a summary introduction to adaptation and profiling are given. We then introduce three criteria for the evaluation of exhibition booth: effectiveness, efficiency and affect. Effectiveness is related the amount of information collected, efficiency is a measurement of the time taken to collect the information, and affect is the perception of the experience and the mood booth visitors have during and after their visit. We have selected these criteria to assess adaptive and profiled exhibition booths, we call smart exhibition (SmartEx). The assessment is performed with an experiment with three test conditions (non-profiled/non adaptive, profiled/non-adaptive and profiled adaptive presentations). Results of the experiment are presented along discussion. While there is significant improvements of effectiveness and efficiency between the two-first test conditions, the improvement is not significant for the last test condition, for reasons explained. As for the affect, the results show that it has an under-estimated importance in people minds and that it should be addressed more carefully
Measuring the Invisible Higgs Width at the 7 and 8 TeV LHC
The LHC is well on track toward the discovery or exclusion of a light
Standard Model (SM)-like Higgs boson. Such a Higgs has a very small SM width
and can easily have large branching fractions to physics beyond the SM, making
Higgs decays an excellent opportunity to observe new physics. Decays into
collider-invisible particles are particularly interesting as they are
theoretically well motivated and relatively clean experimentally. In this work
we estimate the potential of the 7 and 8 TeV LHC to observe an invisible Higgs
branching fraction. We analyze three channels that can be used to directly
study the invisible Higgs branching ratio at the 7 TeV LHC: an invisible Higgs
produced in association with (i) a hard jet; (ii) a leptonic Z; and (iii)
forward tagging jets. We find that the last channel, where the Higgs is
produced via weak boson fusion, is the most sensitive, allowing branching
fractions as small as 40% to be probed at 20 inverse fb for masses in the range
between 120 and 170 GeV, including in particular the interesting region around
125 GeV. We provide an estimate of the 8 TeV LHC sensitivity to an
invisibly-decaying Higgs produced via weak boson fusion and find that the reach
is comparable to but not better than the reach at the 7 TeV LHC. We further
estimate the discovery potential at the 8 TeV LHC for cases where the Higgs has
substantial branching fractions to both visible and invisible final states.Comment: 23 pages, 7 figures. v2: version published in JHEP. 8 TeV analysis
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Matter-gravity interaction in a multiply warped braneworld,
The role of a bulk graviton in predicting the signature of extra dimensions
through collider-based experiments is explored in the context of a multiply
warped spacetime. In particular it is shown that in a doubly warped braneworld
model, the presence of the sixth dimension, results in enhanced concentration
of graviton Kaluza Klein (KK) modes compared to that obtained in the usual
5-dimensional Randall-Sundrum model. Also, the couplings of these massive
graviton KK modes with the matter fields on the visible brane turn out to be
appreciably larger than that in the corresponding 5- dimensional model. The
significance of these results are discussed in the context of KK graviton
search at the Large Hadron Collider (LHC).Comment: 13 pages, 2 table
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