90 research outputs found
Association of changes in the use of board-certified critical care intensivists with mortality outcomes for trauma patients at a well-established level I urban trauma center
NLSP Gluino Search at the Tevatron and early LHC
We investigate the collider phenomenology of gluino-bino co-annihilation
scenario both at the Tevatron and 7 TeV LHC. This scenario can be realized, for
example, in a class of realistic supersymmetric models with non-universal
gaugino masses and t-b-\tau Yukawa unification. The NLSP gluino and LSP bino
should be nearly degenerate in mass, so that the typical gluino search channels
involving leptons or hard jets are not available. Consequently, the gluino can
be lighter than various bounds on its mass from direct searches. We propose a
new search for NLSP gluino involving multi-b final states, arising from the
three-body decay \tilde{g}-> b\bar{b}\tilde{\chi}_1^0. We identify two
realistic models with gluino mass of around 300 GeV for which the three-body
decay is dominant, and show that a 4.5 \sigma observation sensitivity can be
achieved at the Tevatron with an integrated luminosity of 10 fb^{-1}. For the 7
TeV LHC with 50 pb^{-1} of integrated luminosity, the number of signal events
for the two models is O(10), to be compared with negligible SM background
event.Comment: 14 pages, 4 figures and 3 tables, minor modifications made and
accepted for publication in JHE
General Gauge and Anomaly Mediated Supersymmetry Breaking in Grand Unified Theories with Vector-Like Particles
In Grand Unified Theories (GUTs) from orbifold and various string
constructions the generic vector-like particles do not need to form complete
SU(5) or SO(10) representations. To realize them concretely, we present
orbifold SU(5) models, orbifold SO(10) models where the gauge symmetry can be
broken down to flipped SU(5) X U(1)_X or Pati-Salam SU(4)_C X SU(2)_L X SU(2)_R
gauge symmetries, and F-theory SU(5) models. Interestingly, these vector-like
particles can be at the TeV-scale so that the lightest CP-even Higgs boson mass
can be lifted, or play the messenger fields in the Gauge Mediated Supersymmetry
Breaking (GMSB). Considering GMSB, ultraviolet insensitive Anomaly Mediated
Supersymmetry Breaking (AMSB), and the deflected AMSB, we study the general
gaugino mass relations and their indices, which are valid from the GUT scale to
the electroweak scale at one loop, in the SU(5) models, the flipped SU(5) X
U(1)_X models, and the Pati-Salam SU(4)_C X SU(2)_L X SU(2)_R models. In the
deflected AMSB, we also define the new indices for the gaugino mass relations,
and calculate them as well. Using these gaugino mass relations and their
indices, we may probe the messenger fields at intermediate scale in the GMSB
and deflected AMSB, determine the supersymmetry breaking mediation mechanisms,
and distinguish the four-dimensional GUTs, orbifold GUTs, and F-theory GUTs.Comment: RevTex4, 45 pages, 15 tables, version to appear in JHE
R-parity violation in SU(5)
We show that judiciously chosen R-parity violating terms in the minimal
renormalizable supersymmetric SU(5) are able to correct all the
phenomenologically wrong mass relations between down quarks and charged
leptons. The model can accommodate neutrino masses as well. One of the most
striking consequences is a large mixing between the electron and the Higgsino.
We show that this can still be in accord with data in some regions of the
parameter space and possibly falsified in future experiments.Comment: 30 pages, 1 figure. Revised version. To appear in JHE
Realistic Standard Model Fermion Mass Relations in Generalized Minimal Supergravity (GmSUGRA)
Grand Unified Theories (GUTs) usually predict wrong Standard Model (SM)
fermion mass relation m_e/m_{\mu} = m_d/m_s toward low energies. To solve this
problem, we consider the Generalized Minimal Supergravity (GmSUGRA) models,
which are GUTs with gravity mediated supersymmetry breaking and higher
dimensional operators. Introducing non-renormalizable terms in the super- and
K\"ahler potentials, we can obtain the correct SM fermion mass relations in the
SU(5) model with GUT Higgs fields in the {\bf 24} and {\bf 75} representations,
and in the SO(10) model. In the latter case the gauge symmetry is broken down
to SU(3)_C X SU(2)_L X SU(2)_R X U(1)_{B-L}, to flipped SU(5)X U(1)_X, or to
SU(3)_C X SU(2)_L X U(1)_1 X U(1)_2. Especially, for the first time we generate
the realistic SM fermion mass relation in GUTs by considering the
high-dimensional operators in the K\"ahler potential.Comment: JHEP style, 29 pages, no figure,references adde
Antibacterial activity of Artemisia nilagirica leaf extracts against clinical and phytopathogenic bacteria
<p>Abstract</p> <p>Background</p> <p>The six organic solvent extracts of <it>Artemisia nilagirica </it>were screened for the potential antimicrobial activity against phytopathogens and clinically important standard reference bacterial strains.</p> <p>Methods</p> <p>The agar disk diffusion method was used to study the antibacterial activity of <it>A. nilagirica </it>extracts against 15 bacterial strains. The Minimum Inhibitory Concentration (MIC) of the plant extracts were tested using two fold agar dilution method at concentrations ranging from 32 to 512 μg/ml. The phytochemical screening of extracts was carried out for major phytochemical derivatives in <it>A. nilagirica</it>.</p> <p>Results</p> <p>All the extracts showed inhibitory activity for gram-positive and gram-negative bacteria except for <it>Klebsiella pneumoniae, Enterococcus faecalis </it>and <it>Staphylococcus aureus</it>. The hexane extract was found to be effective against all phytopathogens with low MIC of 32 μg/ml and the methanol extract exhibited a higher inhibition activity against <it>Escherichia coli, Yersinia enterocolitica, Salmonella typhi</it>, <it>Enterobacter aerogenes</it>, <it>Proteus vulgaris</it>, <it>Pseudomonas aeruginosa </it>(32 μg/ml), <it>Bacillus subtilis </it>(64 μg/ml) and <it>Shigella flaxneri </it>(128 μg/ml). The phytochemical screening of extracts answered for the major derivative of alkaloids, amino acids, flavonoids, phenol, quinines, tannins and terpenoids.</p> <p>Conclusion</p> <p>All the extracts showed antibacterial activity against the tested strains. Of all, methanol and hexane extracts showed high inhibition against clinical and phytopathogens, respectively. The results also indicate the presence of major phytochemical derivatives in the <it>A. nilagirica </it>extracts. Hence, the isolation and purification of therapeutic potential compounds from <it>A. nilagirica </it>could be used as an effective source against bacterial diseases in human and plants.</p
Impact of LHC Searches on NLSP Top Squark and Gluino Mass
We explore the implications of 7 TeV LHC searches for a scenario in which one
of the stops is the next-to lightest supersymmetric particle (NLSP). The NLSP
stop (\tilde{t}_1) is assumed to decay exclusively into neutralino and charm
quark. We consider processes where the stops are pair produced together with a
hard QCD jet. We also consider stop quarks from gluino decays, \tilde{g}\to
t\tilde{t}_1^\ast+\bar{t}\tilde{t}_1. We show that the monojet ATLAS and CMS
searches corresponding to 1 fb^{-1} of integrated luminosity are sensitive to
stop masses of up to 160 GeV, with the 20% neutralino-stop coannihilation
region essentially ruled out for M_{\tilde{t}_1}\lesssim 140 GeV. The region
M_{\tilde{t}_1}\lesssim 130 GeV is excluded with even relatively larger mass
difference, M_{\tilde{t}_1}-M_{\tilde{\chi}_1^0}\sim 40 GeV, by the multi-jets
search. The b-jet and same-sign dilepton searches are sensitive to a heavier
gluino because they only pick up gluino pair production events followed by top
quarks decaying into b-jets and same-sign dileptons, respectively. We find that
the LHC data places a lower limit on the gluino mass in this scenario of about
600 GeV (700 GeV) from b-jets (same-sign dileptons) searches.Comment: 18 pages, 10 figures and 4 table
125 GeV Higgs Boson from t-b-tau Yukawa Unification
We identify a class of supersymmetric SU(4)_c x SU(2)_L x SU(2)_R models in
which imposing essentially perfect t-b-tau Yukawa coupling unification at M_GUT
yields a mass close to 122-126 GeV for the lightest CP-even (SM-like) Higgs
boson. The squark and gluino masses in these models exceed 3 TeV, but the stau
and charginos in some cases can be considerably lighter. We display some
benchmark points corresponding to neutralino-stau and bino-wino coannihilations
as well as A-resonance. The well-known MSSM parameter tan beta is around 46-52.Comment: 16 pages, 4 figure
Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.
Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability
- …