739 research outputs found
The Efficacy of Common Prosthetic Joint Infection Prevention Strategies: A Systematic Review
Thousands of total hip and knee arthroplasty patients suffer from prosthetic joint infections every year, making them a leading cause of arthroplasty failure. As the number of these procedures continues to grow, so will the healthcare and socio-economic burden of prosthetic joint infections. A comprehensive search for up-to-date literature was completed via the PubMed database, identifying eighteen retrospective and prospective cohort studies that focused on the four prosthetic joint infection prevention methods of interest. Tobacco use cessation of all forms is an efficacious prosthetic joint infection prevention strategy. The common practices of withholding intra-articular injections prior to surgery, using prophylactic single dose cephalosporins, and using the glycemic marker of HbA1c were found to be partially efficacious but require further considerations. Surgeons should be aware of the various considerations involved in validating or discrediting their preferred prevention strategies in order to prevent prosthetic joint infection
Sensitivity and threshold dynamics of Pinus strobus and Quercus spp. in response to experimental and naturally-occurring severe droughts
Increased drought frequency and severity are a pervasive global threat, yet the capacity of mesic temperate forests to maintain resilience in response to drought remains poorly understood. We deployed a throughfall removal experiment to simulate a once in a century drought in New Hampshire, USA, which coupled with the region-wide 2016 drought, intensified moisture stress beyond that experienced in the lifetimes of our study trees. To assess the sensitivity and threshold dynamics of two dominant northeastern tree genera (Quercus and Pinus), we monitored sap flux density (Js), leaf water potential and gas exchange, growth, and intrinsic water use efficiency (iWUE) for one pretreatment year (2015) and two treatment years (2016-17). Results showed that Js in pine (P. strobus) declined abruptly at a soil moisture threshold of 0.15 m3m-3 , while oak’s (Q. rubra and Q. velutina) threshold was 0.11 m3m-3 — a finding consistent with pine’s more isohydric strategy. Nevertheless, once oaks’ moisture threshold was surpassed, Js declined abruptly, suggesting that while oaks are well-adapted to moderate drought, they are highly susceptible to extreme drought. The radial growth reduction in response to the 2016 drought was more than twice as great for pine than for oaks (50% vs. 18% respectively). Despite relatively high precipitation in 2017, the oaks’ growth continued to decline (low recovery), whereas pine showed neutral (treatment) or improved (control) growth. iWUE increased in 2016 for both treatment and control pines, but only in treatment oaks. Notably, pines exhibited a significant linear relationship between iWUE and precipitation across years, whereas the oaks only showed a response during the driest conditions, further underscoring the different sensitivity thresholds for these species. Our results provide new insights into how interactions between temperate forest tree species’ contrasting physiologies and soil moisture thresholds influence their responses and resilience to extreme drought
Low-loss, compact, fibre-integrated cell for quantum memories
We present a low-loss, compact, hollow core optical fibre (HCF) cell
integrated with single mode fibre (SMF). The cell is designed to be filled with
atomic vapour and used as a component in photonic quantum technologies, with
applications in quantum memory and optical switching. We achieve a total
insertion loss of 0.6(2) dB at 780 nm wavelength via graded index fibre to
ensure efficient mode matching coupled with anti-reflection coatings to
minimise loss at the SMF-HCF interfaces. We also present numerical modelling of
these interfaces, which can be undertaken efficiently without the need for
finite element simulation. We encapsulate the HCF core by coupling to the SMF
inside a support capillary, enhancing durability and facilitating seamless
integration into existing fibre platforms
Aggressive pituitary adenomas occurring in young patients in a large Polynesian kindred with a germline R271W mutation in the AIP gene.
peer reviewedOBJECTIVE: Mutations in the aryl hydrocarbon receptor-interacting protein (AIP) were recently shown to confer a pituitary adenoma predisposition in patients with familial isolated pituitary adenomas (FIPA). We report a large Samoan FIPA kindred from Australia/New Zealand with an R271W mutation that was associated with aggressive pituitary tumors. DESIGN AND METHODS: Case series with germline screening of AIP and haplotype analyses among R271W families. RESULTS: This previously unreported kindred consisted of three affected individuals that either presented with or had first symptoms of a pituitary macroadenoma in late childhood or adolescence. The index case, a 15-year-old male with incipient gigantism and his maternal aunt, had somatotropinomas, and the maternal uncle of the index case had a prolactinoma. All tumors were large (15, 40, and 60 mm maximum diameter) and two required transcranial surgery and radiotherapy. All three affected subjects and ten other unaffected relatives were found to be positive for a germline R271W AIP mutation. Comparison of the single nucleotide polymorphism patterns among this family and two previously reported European FIPA families with the same R271W mutation demonstrated no common ancestry. CONCLUSIONS: This kindred exemplifies the aggressive features of pituitary adenomas associated with AIP mutations, while genetic analyses among three R271W FIPA families indicate that R271W represents a mutational hotspot that should be studied further in functional studies
Astrophysical factors:Zero energy vs. Most effective energy
Effective astrophysical factors for non-resonant astrophysical nuclear
reaction are invariably calculated with respect to a zero energy limit. In the
present work that limit is shown to be very disadvantageous compared to the
more natural effective energy limit. The latter is used in order to modify the
thermonuclear reaction rate formula so that it takes into account both plasma
and laboratory screening effects.Comment: 7 RevTex pages. Accepted for publication in Phys.Rev.
Enhanced phenotypes for identifying opioid overdose in emergency department visit electronic health record data
Background
Accurate identification of opioid overdose (OOD) cases in electronic healthcare record (EHR) data is an important element in surveillance, empirical research, and clinical intervention. We sought to improve existing OOD electronic phenotypes by incorporating new data types beyond diagnostic codes and by applying several statistical and machine learning methods.
Materials and Methods
We developed an EHR dataset of emergency department visits involving OOD cases or patients considered at risk for an OOD and ascertained true OOD status through manual chart reviews. We developed and validated prediction models using Random Forest, Extreme Gradient Boost, and Elastic Net models that incorporated 717 features involving primary and second diagnoses, chief complaints, medications prescribed, vital signs, laboratory results, and procedural codes. We also developed models limited to single data types.
Results
A total of 1718 records involving 1485 patients were manually reviewed; 541 (36.4%) patients had one or more OOD. Prediction performance was similar for all models; sensitivity varied from 94% to 97%; and area under the receiver operating characteristic curve (AUC) was 98% for all methods. The primary diagnosis and chief complaint were the most important contributors to AUC performance; primary diagnoses and medication class contributed most to sensitivity; chief complaint, primary diagnosis, and vital signs were most important for specificity. Models limited to decision support data types available in real time demonstrated robust prediction performance.
Conclusions
Substantial prediction performance improvements were demonstrated for identifying OODs in EHR data. Our e-phenotypes could be applied in surveillance, retrospective empirical applications, or clinical decision support systems
NLL resummation of jet mass
Starting from a factorization theorem in effective field theory, we present
resummed results for two non-global observables: the invariant-mass
distribution of jets and the energy distribution outside jets. Our results
include the full next-to-leading-order corrections to the hard, jet and soft
functions and are implemented in a parton-shower framework which generates the
renormalization-group running in the effective theory. The inclusion of these
matching corrections leads to an improved description of the data and reduced
theoretical uncertainties. They will have to be combined with two-loop running
in the future, but our results are an important first step towards the
higher-logarithmic resummation of non-global observables.Comment: 32 pages, 12 figures. v2: journal versio
Local models of stellar convection: Reynolds stresses and turbulent heat transport
We study stellar convection using a local three-dimensional MHD model, with
which we investigate the influence of rotation and large-scale magnetic fields
on the turbulent momentum and heat transport. The former is studied by
computing the Reynolds stresses, the latter by calculating the correlation of
velocity and temperature fluctuations, both as functions of rotation and
latitude. We find that the horisontal correlation, Q_(theta phi), capable of
generating horisontal differential rotation, is mostly negative in the southern
hemisphere for Coriolis numbers exceeding unity, corresponding to equatorward
flux of angular momentum in accordance with solar observations. The radial
component Q_(r phi) is negative for slow and intermediate rotation indicating
inward transport of angular momentum, while for rapid rotation, the transport
occurs outwards. Parametrisation in terms of the mean-field Lambda-effect shows
qualitative agreement with the turbulence model of Kichatinov & R\"udiger
(1993) for the horisontal part H \propto Q_(theta phi)/cos(theta), whereas for
the vertical part, V \propto Q_(r phi)/sin(theta), agreement only for
intermediate rotation exists. The Lambda-coefficients become suppressed in the
limit of rapid rotation, this rotational quenching being stronger for the V
component than for H. We find that the stresses are enhanced by the presence of
the magnetic field for field strengths up to and above the equipartition value,
without significant quenching. Concerning the turbulent heat transport, our
calculations show that the transport in the radial direction is most efficient
at the equatorial regions, obtains a minimum at midlatitudes, and shows a
slight increase towards the poles. The latitudinal heat transport does not show
a systematic trend as function of latitude or rotation.Comment: 26 pages, 20 figures, final published version. For a version with
higher resolution figures, see http://cc.oulu.fi/~pkapyla/publ.htm
Surface flux evolution constraints for flux transport dynamos
The surface flux transport (SFT) model of solar magnetic fields involves
empirically well-constrained velocity and magnetic fields. The basic evolution
of the Sun's large-scale surface magnetic field is well described by this
model. The azimuthally averaged evolution of the SFT model can be compared to
the surface evolution of the flux transport dynamo (FTD), and the evolution of
the SFT model can be used to constrain several near-surface properties of the
FTD model.
We compared the results of the FTD model with different upper boundary
conditions and diffusivity profiles against the results of the SFT model. Among
the ingredients of the FTD model, downward pumping of magnetic flux, related to
a positive diffusivity gradient, has a significant effect in slowing down the
diffusive radial transport of magnetic flux through the solar surface. Provided
the pumping was strong enough to give rise to a downflow of a magnetic Reynolds
number of 5 in the near-surface boundary layer, the FTD using a vertical
boundary condition matches the SFT model based on the average velocities above
the boundary layer. The FTD model with a potential field were unable to match
the SFT results.Comment: Accepted for A&
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