556 research outputs found
Validation of a fully autonomous phosphate analyser based on a microfluidic lab-on-a-chip
This work describes the design of a phosphate analyser that utilises a microfluidic lab-on-a-chip. The analyser contains all the required chemical storage, pumping and electronic components to carry out a complete phosphate assay. The system is self-calibrating and self-cleaning, thus capable of long-term operation. This was proven by a bench top calibration of the analyser using standard solutions and also by comparing the analyser's performance to a commercially available phosphate monitor installed at a waste water treatment plant. The output of the microfluidic lab-on-a-chip analyser was shown to have sensitivity and linear range equivalent to the commercially available monitor and also the ability to operate over an extended period of time
Considering innate immune responses in SARS-CoV-2 infection and COVID-19
During the COVID-19 pandemic, much of the media focus has been on adaptive immunity, particularly antibody levels and memory T cells. However, immunologists have been striving to decipher how SARS-CoV-2 infection impacts our first line of defence, namely the innate immune system. In early 2022, Program staff from the NIAID at the NIH organized a workshop focusing on the innate immune response to SARS-CoV-2 infection and during COVID-19, which was chaired by Ralph Baric, Jenny Ting and John Lambris. Following the meeting, Nature Reviews Immunology invited some of the organizers and speakers to share their thoughts on the key discussion points
Effects of sea level rise on economy of the United States
We report the first ex post study of the economic impact of sea level rise. We apply two econometric approaches to estimate the past effects of sea level rise on the economy of the USA, viz. Barro type growth regressions adjusted for spatial patterns and a matching estimator. Unit of analysis is 3063 counties of the USA. We fit growth regressions for 13 time periods and we estimated numerous varieties and robustness tests for both growth regressions and matching estimator. Although there is some evidence that sea level rise has a positive effect on economic growth, in most specifications the estimated effects are insignificant. We therefore conclude that there is no stable, significant effect of sea level rise on economic growth. This finding contradicts previous ex ante studies
A ventral rotational skin flap to improve cosmesis and avoid chordee recurrence in epispadias repair.
OBJECTIVE: To describe a technical modification that facilitates dorsal skin closure, improves cosmesis and eliminates chordee recurrence secondary to contracture of the dorsal penile skin in the repair of epispadias.
PATIENTS AND METHODS: Eleven patients with penopubic epispadias (mean age 1.8 years) had the epispadias repaired using a modified ventral penile skin flap. Four patients had isolated epispadias and seven had had a previous primary closure of bladder exstrophy. Nine patients underwent the Cantwell-Ransley technique, leaving the meatus in a glanular position. Two patients were repaired using the penile disassembly technique of Mitchell and Bägli, because they had a short urethral plate. A ventral island skin flap was fashioned, starting at the base of the penis. Dissection was carried ventrally into the scrotum to allow for adequate dorsal flap transposition. The flap was rotated laterally to shift the suture line from the midline and to cover the dorsal aspect of the penis with untouched penile shaft skin. Redundant ventral foreskin was discarded.
RESULTS: All patients had an uneventful course after surgery. Dorsal penile skin was viable in every case and no patient developed recurrence of chordee or a urethrocutaneous fistula. The cosmetic result was excellent in all patients.
CONCLUSIONS: Dorsal skin closure using lateral rotation of ventral penile skin flap improves cosmesis after epispadias repair and eliminates the recurrence of chordee secondary to midline dorsal scarring
Multi-wavelength interferometry of evolved stars using VLTI and VLBA
We report on our project of coordinated VLTI/VLBA observations of the
atmospheres and circumstellar environments of evolved stars. We illustrate in
general the potential of interferometric measurements to study stellar
atmospheres and envelopes, and demonstrate in particular the advantages of a
coordinated multi-wavelength approach including near/mid-infrared as well as
radio interferometry. We have so far made use of VLTI observations of the near-
and mid-infrared stellar sizes and of concurrent VLBA observations of the SiO
maser emission. To date, this project includes studies of the Mira stars S Ori
and RR Aql as well as of the supergiant AH Sco. These sources all show strong
silicate emission features in their mid-infrared spectra. In addition, they
each have relatively strong SiO maser emission. The results from our first
epochs of S Ori measurements have recently been published and the main results
are reviewed here. The S Ori maser ring is found to lie at a mean distance of
about 2 stellar radii, a result that is virtually free of the usual uncertainty
inherent in comparing observations of variable stars widely separated in time
and stellar phase. We discuss the status of our more recent S Ori, RR Aql, and
AH Sco observations, and present an outlook on the continuation of our project.Comment: 9 pages, to appear in the proceedings of the ESO workshop "The Power
of Optical/IR Interferometry: Recent Scientific Results and 2nd Generation
VLTI Instrumentation", ESO Astrophysics Symposi
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV
The Lambda(b) differential production cross section and the cross section
ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum
pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7
TeV using data collected by the CMS experiment at the LHC. The measurements are
based on Lambda(b) decays reconstructed in the exclusive final state J/Psi
Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and
Lambda to proton pion, using a data sample corresponding to an integrated
luminosity of 1.9 inverse femtobarns. The product of the cross section times
the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls
faster than that of b mesons. The measured value of the cross section times the
branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06
+/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for
anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are
statistical and systematic, respectively.Comment: Submitted to Physics Letters
Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV
A search is presented for physics beyond the standard model (BSM) in final
states with a pair of opposite-sign isolated leptons accompanied by jets and
missing transverse energy. The search uses LHC data recorded at a
center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to
an integrated luminosity of approximately 5 inverse femtobarns. Two
complementary search strategies are employed. The first probes models with a
specific dilepton production mechanism that leads to a characteristic kinematic
edge in the dilepton mass distribution. The second strategy probes models of
dilepton production with heavy, colored objects that decay to final states
including invisible particles, leading to very large hadronic activity and
missing transverse energy. No evidence for an event yield in excess of the
standard model expectations is found. Upper limits on the BSM contributions to
the signal regions are deduced from the results, which are used to exclude a
region of the parameter space of the constrained minimal supersymmetric
extension of the standard model. Additional information related to detector
efficiencies and response is provided to allow testing specific models of BSM
physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO
Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV
Isolated photon production is measured in proton-proton and lead-lead
collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the
pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80
GeV with the CMS detector at the LHC. The measured ET spectra are found to be
in good agreement with next-to-leading-order perturbative QCD predictions. The
ratio of PbPb to pp isolated photon ET-differential yields, scaled by the
number of incoherent nucleon-nucleon collisions, is consistent with unity for
all PbPb reaction centralities.Comment: Submitted to Physics Letters
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