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Inaccurate representations of iceberg calving from ice shelves are a large source of uncertainty in mass-loss projections from the Antarctic ice sheet. Here, we address this limitation by implementing and testing a continuum damage-mechanics model in a continental scale ice-sheet model. The damage-mechanics formulation, based on a linear stability analysis and subsequent long-wavelength approximation of crevasses that evolve in a viscous medium, links damage evolution to climate forcing and the large-scale stresses within an ice shelf. We incorporate this model into the BISICLES ice-sheet model and test it by applying it to idealized (1) ice tongues, for which we present analytical solutions and (2) buttressed ice-shelf geometries. Our simulations show that the model reproduces the large disparity in lengths of ice shelves with geometries and melt rates broadly similar to those of four Antarctic ice shelves: Erebus Glacier Tongue (length ~ 13 km), the unembayed portion of Drygalski Ice Tongue (~ 65 km), the Amery Ice Shelf (~ 350 km) and the Ross Ice Shelf (~ 500 km). These results demonstrate that our simple continuum model holds promise for constraining realistic ice-shelf extents in large-scale ice-sheet models in a computationally tractable manner.
Combined approaches are often necessary to address large or invasive skull base pathology. A combined suboccipital craniotomy and neck dissection is often utilized for invasive posterior fossa skull base tumors and neck tumors. Management of these tumors often requires the collaboration of multiple specialties. Tumors in this location are often intimately involved with important neurovascular structures. Good pre-operative evaluation, intra-operative monitoring, and closely monitored post-operative care are essential. The extent of resection and goals of care depends on a case-by-case analysis including the patient’s age, the aggressiveness of the tumor pathology, presenting symptoms, and comorbidities. This chapter reviews the indications, anatomy, and surgical nuances of this complex approach.
Background:Candida auris is an emerging multidrug-resistant pathogen associated with outbreaks in hospitals and skilled nursing facilities (SNFs). Patients with C. auris can have invasive disease or asymptomatic colonization. Because C. auris can be difficult to treat and eradicate in the environment, the CDC recommends using contact precautions and sporicidal agents during patient care. After C. auris was identified in a patient from an LA County SNF (SNF-X), our institution initiated surveillance screening on high-risk patients. Methods: Nurses identified patients residing at SNF-X on admission and contacted infection prevention. These patients were placed on contact or spore precautions. Bilateral axilla and inguinal folds were swabbed with an Eswab and sent for testing by a clinical laboratory-developed RT PCR assay, which can detect C. auris with high sensitivity and specificity with a rapid turnaround time (4–6 hours). This PCR assay was based on a commercial platform IntegratedCycler (Diasorin) and reagents from the same vendor. Environmental swabs from the index patient’s room were sent for PCR by HardyCHROM Candida agar (Hardy Diagnostics) before and after cleaning with OxyCideTM. PCR-positive samples were set up for culture. Results: In total, 27 patients from SNF-X were screened by PCR. Of these patients, 15 (55%) had a tracheostomy present on admission. Moreover, 26 swabs were negative; 1 was positive in the index patient (cycle threshold [Ct] value, 26). Clinical specimens from the index patient’s blood did not grow C. auris; the tracheostomy sample grew predominantly C. albicans which made identification of C. auris challenging by culture. However, investigational testing of this sample by PCR was positive (Ct value, 31). Environmental swabs collected from the patient room were obtained before and after cleaning (Table 1); all environmental cultures were negative at 5 days. Conclusions: Developing hospital-based, high-risk patient screening for C. auris is feasible and may be useful for controlling the spread of C. auris within the community. Further study is needed to determine the usefulness of PCR for environmental testing to assess the risk of nosocomial transmission of C. auris.
Antarctica's ice shelves modulate the grounded ice flow, and weakening of ice shelves due to climate forcing will decrease their ‘buttressing’ effect, causing a response in the grounded ice. While the processes governing ice-shelf weakening are complex, uncertainties in the response of the grounded ice sheet are also difficult to assess. The Antarctic BUttressing Model Intercomparison Project (ABUMIP) compares ice-sheet model responses to decrease in buttressing by investigating the ‘end-member’ scenario of total and sustained loss of ice shelves. Although unrealistic, this scenario enables gauging the sensitivity of an ensemble of 15 ice-sheet models to a total loss of buttressing, hence exhibiting the full potential of marine ice-sheet instability. All models predict that this scenario leads to multi-metre (1–12 m) sea-level rise over 500 years from present day. West Antarctic ice sheet collapse alone leads to a 1.91–5.08 m sea-level rise due to the marine ice-sheet instability. Mass loss rates are a strong function of the sliding/friction law, with plastic laws cause a further destabilization of the Aurora and Wilkes Subglacial Basins, East Antarctica. Improvements to marine ice-sheet models have greatly reduced variability between modelled ice-sheet responses to extreme ice-shelf loss, e.g. compared to the SeaRISE assessments.
We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band (
), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.
We present Phantom, a fast, parallel, modular, and low-memory smoothed particle hydrodynamics and magnetohydrodynamics code developed over the last decade for astrophysical applications in three dimensions. The code has been developed with a focus on stellar, galactic, planetary, and high energy astrophysics, and has already been used widely for studies of accretion discs and turbulence, from the birth of planets to how black holes accrete. Here we describe and test the core algorithms as well as modules for magnetohydrodynamics, self-gravity, sink particles, dust–gas mixtures, H2 chemistry, physical viscosity, external forces including numerous galactic potentials, Lense–Thirring precession, Poynting–Robertson drag, and stochastic turbulent driving. Phantom is hereby made publicly available.
There is strong evidence that people born in winter and in spring have a small increased risk of schizophrenia. As this ‘season of birth’ effect underpins some of the most influential hypotheses concerning potentially modifiable risk exposures, it is important to exclude other possible explanations for the phenomenon.
Here we sought to determine whether the season of birth effect reflects gene-environment confounding rather than a pathogenic process indexing environmental exposure. We directly measured, in 136 538 participants from the UK Biobank (UKBB), the burdens of common schizophrenia risk alleles and of copy number variants known to increase the risk for the disorder, and tested whether these were correlated with a season of birth.
Neither genetic measure was associated with season or month of birth within the UKBB sample.
As our study was highly powered to detect small effects, we conclude that the season of birth effect in schizophrenia reflects a true pathogenic effect of environmental exposure.
Objectives: Total intracranial volume (TICV) is an important control variable in brain–behavior research, yet its calculation has challenges. Manual TICV (Manual) is labor intensive, and automatic methods vary in reliability. To identify an accurate automatic approach we assessed the reliability of two FreeSurfer TICV metrics (eTIV and Brainmask) relative to manual TICV. We then assessed how these metrics alter associations between left entorhinal cortex (ERC) volume and story retention. Methods: Forty individuals with Parkinson’s disease (PD) and 40 non-PD peers completed a brain MRI and memory testing. Manual metrics were compared to FreeSurfer’s Brainmask (a skull strip mask with total volume of gray, white, and most cerebrospinal fluid) and eTIV (calculated using the transformation matrix into Talairach space). Volumes were compared with two-way interclass correlations and dice similarity indices. Associations between ERC volume and Wechsler Memory Scale-Third Edition Logical Memory retention were examined with and without correction using each TICV method. Results: Brainmask volumes were larger and eTIV volumes smaller than Manual. Both automated metrics correlated highly with Manual. All TICV metrics explained additional variance in the ERC-Memory relationship, although none were significant. Brainmask explained slightly more variance than other methods. Conclusions: Our findings suggest Brainmask is more reliable than eTIV for TICV correction in brain-behavioral research. (JINS, 2018, 24, 206–211)
I was going to have said that Hegel was blunt, but his reputation precedes him, no doubt, and such an obvious lie would have cast suspicion on the rest of my contribution. Let me say, instead, that he has the virtue of being certain of his interpretation of the history of philosophy, certain of how each part fits into the framework he provides, and certain that providing a framework is the task of philosophy as such. And if even Hegel can be forgiven for any particular misreading, the more troubling betrayal lies in the certainty that philosophy is defined and framed through the articulation of claims – through situating the agency of language in the action of contestation oriented by the progress of science. This framing is the most difficult for academics to avoid, for the technologies of argument (whether consciously Hegelian or not) dominate teaching and publishing throughout the modern academy. That this technology is at stake, and that merely arguing for a more humanistic technology or more open stance toward unconventional claims will not solve the problem, is the difficulty and contribution I seek to draw out of Plato's Protagoras.
At the broadest level, the Hegelian frame is the embodied structure of subjective grasping or comprehension, and Socrates, Plato, and Aristotle are seen as the great precursors to Hegel's insight. Hegel is not accusing the Athenian philosophers of believing that humans possess rationality, or use some sort of rationality as a tool; in fact, his continuing attraction for continental philosophers rests in the idea that participation in the activity of the world constitutes a developing language, unbound by a priori rules of reason or reified ideas of subjectivity. The Athenian trio, Hegel tells us, were the first to turn to the authority of a moral claim in a subject's apprehensions (Socrates’ emphasis on the task of philosophy), of the conceptions themselves (Plato's ideas), and then finally of the process of perfecting those conceptions in a self-conscious appropriation of the reality of one's situation (Aristotle's ἐνέργϵια as ontological foundation grasped in ἐντϵƛϵχϵία).
I was going to have said that Hegel was blunt, but his reputation precedes him, no doubt, and such an obvious lie would have cast suspicion on the rest of my contribution. Let me say, instead, that he has the virtue of being certain of his interpretation of the history of philosophy, certain of how each part fits into the framework he provides, and certain that providing a framework is the task of philosophy as such. And if even Hegel can be forgiven for any particular misreading, the more troubling betrayal lies in the certainty that philosophy is defined and framed through the articulation of claims – through situating the agency of language in the action of contestation oriented by the progress of science. This framing is the most difficult for academics to avoid, for the technologies of argument (whether consciously Hegelian or not) dominate teaching and publishing throughout the modern academy. That this technology is at stake, and that merely arguing for a more humanistic technology or more open stance toward unconventional claims will not solve the problem,1 is the difficulty and contribution I seek to draw out of Plato's Protagoras.
At the broadest level, the Hegelian frame is the embodied structure of subjective grasping or comprehension, and Socrates, Plato, and Aristotle are seen as the great precursors to Hegel's insight. Hegel is not accusing the Athenian philosophers of believing that humans possess rationality, or use some sort of rationality as a tool; in fact, his continuing attraction for continental philosophers rests in the idea that participation in the activity of the world constitutes a developing language, unbound by a priori rules of reason or reified ideas of subjectivity.2 The Athenian trio, Hegel tells us, were the first to turn to the authority of a moral claim in a subject's apprehensions (Socrates’ emphasis on the task of philosophy), of the conceptions themselves (Plato's ideas), and then finally of the process of perfecting those conceptions in a self-conscious appropriation of the reality of one's situation (Aristotle's ἐνέργεια as ontological foundation grasped in ἐντεƛεχεία).
The Protoplanetary Discussions conference—held in Edinburgh, UK, from 2016 March 7th–11th—included several open sessions led by participants. This paper reports on the discussions collectively concerned with the multi-physics modelling of protoplanetary discs, including the self-consistent calculation of gas and dust dynamics, radiative transfer, and chemistry. After a short introduction to each of these disciplines in isolation, we identify a series of burning questions and grand challenges associated with their continuing development and integration. We then discuss potential pathways towards solving these challenges, grouped by strategical, technical, and collaborative developments. This paper is not intended to be a review, but rather to motivate and direct future research and collaboration across typically distinct fields based on community-driven input, to encourage further progress in our understanding of circumstellar and protoplanetary discs.
To concomitantly determine the differential degrees of air and environmental contamination by Acinetobacter baumannii based on anatomic source of colonization and type of ICU layout (single-occupancy vs open layout).
Longitudinal prospective surveillance study of air and environmental surfaces in patient rooms.
A 1,500-bed public teaching hospital in Miami, Florida.
Consecutive A. baumannii–colonized patients admitted to our ICUs between October 2013 and February 2014.
Air and environmental surfaces of the rooms of A. baumannii–colonized patients were sampled daily for up to 10 days. Pulsed-field gel electrophoresis (PFGE) was used to type and match the matching air, environmental, and clinical A. baumannii isolates.
A total of 25 A. baumannii–colonized patients were identified during the study period; 17 were colonized in the respiratory tract and 8 were colonized in the rectum. In rooms with rectally colonized patients, 38.3% of air samples were positive for A. baumannii; in rooms of patients with respiratory colonization, 13.1% of air samples were positive (P=.0001). In rooms with rectally colonized patients, 15.5% of environmental samples were positive for A. baumannii; in rooms of patients with respiratory colonization, 9.5% of environmental samples were positive (P=.02). The rates of air contamination in the open-layout and single-occupancy ICUs were 17.9% and 21.8%, respectively (P=.5). Environmental surfaces were positive in 9.5% of instances in open-layout ICUs versus 13.4% in single-occupancy ICUs (P=.09).
Air and environmental surface contaminations were significantly greater among rectally colonized patients; however, ICU layout did not influence the rate of contamination.
Electroconvulsive therapy (ECT) is the most effective acute treatment for
severe depression, but widely held concerns about memory problems may
limit its use.
To find out whether repeated or maintenance courses of ECT cause
cumulative cognitive deterioration.
Analysis of the results of 10 years of cognitive performance data
collection from patients who have received ECT. The 199 patients had a
total of 498 assessments, undertaken after a mean of 15.3 ECT sessions
(range 0–186). A linear mixed-effect regression model was used, testing
whether an increasing number of ECT sessions leads to deterioration in
The total number of previous ECT sessions had no effect on cognitive
performance. The major factors affecting performance were age, followed
by the severity of depression at the time of testing and the number of
days since the last ECT session.
Repeated courses of ECT do not lead to cumulative cognitive deficits.
This message is reassuring for patients, carers and prescribers who are
concerned about memory problems and confusion during ECT.
Objectives: Kids in Control OF Food (KICk-OFF) is a 5-day structured education program for 11- to 16-year-olds with type 1 diabetes mellitus (T1DM) who are using multiple daily insulin injections. This study evaluates the cost-effectiveness of the KICk-OFF education program compared with the usual care using data from the KICk-OFF trial.
Methods: The short-term within-trial analysis covers the 2-year postintervention period. Data on glycated hemoglobin (HbA1c), severe hypoglycemia, and diabetic ketoacidosis (DKA) were collected over a 2-year follow-up period. Sub-group analyses have been defined on the basis of baseline HbA1c being below 7.5 percent (58.5 mmol/mol) (low group), between 7.5 percent and 9.5 percent (80.3 mmol/mol) (medium group), and over 9.5 percent (high group). The long-term cost-effectiveness evaluation has been conducted by using The Sheffield Type 1 Diabetes Policy Model, which is a patient-level simulation model on T1DM. It includes long-term microvascular (retinopathy, neuropathy, and nephropathy) and macrovascular (myocardial infarction, stroke, revascularization, and angina) diabetes-related complications and acute adverse events (severe hypoglycemia and DKA).
Results: The most favorable within-trial scenario for the KICk-OFF arm led to an incremental cost-effectiveness ratio (ICER) of £23,688 (base year 2009) with a cost-effectiveness probability of 41.3 percent. Simulating the long-term complications using the full cohort data, the mean ICER for the base case was £28,813 (base year 2011) and the probability of the KICk-OFF intervention being cost-effective at £20,000/QALY threshold was 42.6 percent, with considerable variation due to treatment effect duration. For the high HbA1c sub-group, the KICk-OFF arm was “dominant” (meaning it provided better health gains at lower costs than usual care) over the usual care arm in each scenario considered.
Conclusions: For the whole study population, the cost-effectiveness of KICk-OFF depends on the assumption for treatment effect duration. For the high baseline HbA1c sub-group, KICk-OFF arm was estimated to be dominant over the usual care arm regardless of the assumption on the treatment effect duration.
Whether contact precautions (CP) are required to control the endemic transmission of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) in acute care hospitals is controversial in light of improvements in hand hygiene, MRSA decolonization, environmental cleaning and disinfection, fomite elimination, and chlorhexidine bathing.
To provide a framework for decision making around use of CP for endemic MRSA and VRE based on a summary of evidence related to use of CP, including impact on patients and patient care processes, and current practices in use of CP for MRSA and VRE in US hospitals.
A literature review, a survey of Society for Healthcare Epidemiology of America Research Network members on use of CP, and a detailed examination of the experience of a convenience sample of hospitals not using CP for MRSA or VRE.
Hospital epidemiologists and infection prevention experts.
No high quality data support or reject use of CP for endemic MRSA or VRE. Our survey found more than 90% of responding hospitals currently use CP for MRSA and VRE, but approximately 60% are interested in using CP in a different manner. More than 30 US hospitals do not use CP for control of endemic MRSA or VRE.
Higher quality research on the benefits and harms of CP in the control of endemic MRSA and VRE is needed. Until more definitive data are available, the use of CP for endemic MRSA or VRE in acute care hospitals should be guided by local needs and resources.
Infect Control Hosp Epidemiol 2015;36(10):1163–1172