bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surveillance and Molecular Epidemiology of Klebsiella pneumoniae Isolates That Produce Carbapenemases: First Report of OXA-48-Like Enzymes in North America
Authors: Lascols Christine , Peirano Gisele , Hackel Meredith , Laupland Kevin B. , Pitout Johann D. D. 
Published: October 2012

ABSTRACT

A study was designed to characterize nonrepeat isolates of carbapenemase-producing
K. pneumoniae
obtained from the SMART worldwide surveillance program during 2008 and 2009. Characterization was done by PCR and sequencing for
bla
VIM
,
bla
IMP
,
bla
NDM
,
bla
OXA
,
bla
KPC
, and plasmid-mediated quinolone resistance and virulence factors (VFs). Genetic relatedness was determined with pulsed-field gel electrophoresis (PFGE) using XbaI and multilocus sequence typing. A total of 110 isolates were included; 47 possess genes that encode
K. pneumoniae
carbapenemases (KPCs), 26 NDMs, 19 VIMs, 13 OXA-48-like, and 5 imipenems (IMPs). We identified 3 different major sequence types (STs) among 65% of the isolates (i.e., ST11 [
n
= 11], ST147 [
n
= 23], and ST258 [
n
= 38]). ST11 and ST147, producing OXA-48-like and NDMs, were found in Argentina, Turkey, Greece, Italy, and India; ST258, producing KPCs, was present in the United States, Israel, Greece, and Puerto Rico. The major STs consisted of up to 4 different pulsotypes, and each pulsotype had a specific geographical distribution. A new ST, named ST903, with
bla
IMP-26
, was identified in the Philippines, while two
bla
OXA-48
-positive isolates were detected in the United States. There were no significant differences in the distribution of the VFs between the isolates; all were positive for
fimH
,
mrkD
,
wabG
, and
ureA
. This is the first report of OXA-48-like enzymes in North America. Our study highlights the importance of surveillance programs using molecular techniques as powerful tools to identify the importance of international sequence types.
The Haemophilus influenzae Sap Transporter Mediates Bacterium-Epithelial Cell Homeostasis
Authors: Raffel Forrest K. , Szelestey Blake R. , Beatty Wandy L. , Mason Kevin M. 
Published: October 2012

ABSTRACT

Nontypeable
Haemophilus influenzae
(NTHI) is a commensal inhabitant of the human nasopharynx and a causative agent of otitis media and other diseases of the upper and lower human airway. During colonization within the host, NTHI must acquire essential nutrients and evade immune attack. We previously demonstrated that the NTHI Sap transporter, an inner membrane protein complex, mediates resistance to antimicrobial peptides and is required for heme homeostasis. We hypothesized that Sap transporter functions are critical for NTHI interaction with the host epithelium and establishment of colonization. Thus, we cocultured the parent or the
sapA
mutant on polarized epithelial cells grown at an air-liquid interface, as a physiological model of NTHI colonization, to determine the contribution of the Sap transporter to bacterium-host cell interactions. Although SapA-deficient NTHI was less adherent to epithelial cells, we observed a significant increase in invasive bacteria compared to the parent strain. Upon internalization, the
sapA
mutant appeared free in the cytoplasm, whereas the parent strain was primarily found in endosomes, indicating differential subcellular trafficking. Additionally, we observed reduced inflammatory cytokine production by the epithelium in response to the
sapA
mutant strain compared to the parental strain. Furthermore, chinchilla middle ears challenged with the
sapA
mutant demonstrated a decrease in disease severity compared to ears challenged with the parental strain. Collectively, our data suggest that NTHI senses host environmental cues via Sap transporter function to mediate interaction with host epithelial cells. Epithelial cell invasion and modulation of host inflammatory cytokine responses may promote NTHI colonization and access to essential nutrients.
A systematic review of the psychological factors associated with returning to sport following injury
Authors: Ardern Clare L , Taylor Nicholas F , Feller Julian A , Webster Kate E 
Published: October 2012

BackgroundPsychological factors have been shown to be associated with the recovery and rehabilitation period following sports injury, but less is known about the psychological response associated with returning to sport after injury. The aim of this review was to identify psychological factors associated with returning to sport following sports injury evaluated with the self-determination theory framework.Study designSystematic review.MethodElectronic databases were searched from the earliest possible entry to March 2012. Quantitative studies were reviewed that included athletes who had sustained an athletic injury, reported the return to sport rate and measured at least one psychological variable. The risk of bias in each study was appraised with a quality checklist.ResultsEleven studies that evaluated 983 athletes and 15 psychological factors were included for review. The three central elements of self-determination theory—autonomy, competence and relatedness were found to be related to returning to sport following injury. Positive psychological responses including motivation, confidence and low fear were associated with a greater likelihood of returning to the preinjury level of participation and returning to sport more quickly. Fear was a prominent emotional response at the time of returning to sport despite the fact that overall emotions became more positive as recovery and rehabilitation progressed.ConclusionsThere is preliminary evidence that positive psychological responses are associated with a higher rate of returning to sport following athletic injury, and should be taken into account by clinicians during rehabilitation.
Cost-effectiveness of total hip arthroplasty versus resurfacing arthroplasty: economic evaluation alongside a clinical trial
Authors: Edlin Richard , Tubeuf Sandy , Achten Juul , Parsons Nicholas , Costa Matthew 
Published: October 2012

ObjectiveTo report on the relative cost-effectiveness of total hip arthroplasty and resurfacing arthroplasty (replacement of articular surface of femoral head only) in patients with severe arthritis suitable for hip joint resurfacing arthroplasty.DesignCost-effectiveness analysis on an intention-to-treat basis of a single-centre, single-blind randomised controlled trial of 126 adult patients within 12 months of treatment. Missing data were imputed using multiple imputations with differences in baseline quality of life and gender adjusted using regression techniques.SettingA large teaching hospital trust in the UK.ParticipantsA total of 126 adult patients with severe arthritis of the hip joint suitable for a resurfacing arthroplasty of the hip.ResultsData were received for 126 patients, 4 of whom did not provide any resource use data. For the remainder, data were imputed for costs or quality of life in at least one time point (baseline, 3, 6 months and 1 year) for 18 patients. Patients in the resurfacing arm had higher quality of life at 12 months (0.795 vs 0.727) and received 0.032 more QALYs within the first 12 months postoperation. At an additional cost of £564, resurfacing arthroplasty offers benefits at £17 451 per QALY within the first 12 months of treatment. When covariates are considered, the health economic case is stronger in men than in women.ConclusionsResurfacing arthroplasty appears to offer very short-term efficiency benefits over total hip arthroplasty within a selected patient group. The short-term follow-up in this trial should be noted, particularly in light of the concerns raised regarding adverse reactions to metal debris from metal-on-metal bearing surfaces in the longer term. Longer-term follow-up of resurfacing arthroplasty patients and decision analytic modelling is also advised.Trial registrationCurrent controlled TrialsISRCTN33354155. UKCRN 4093.
Experiences with global trigger tool reviews in five Danish hospitals: an implementation study
Authors: von Plessen Christian , Kodal Anne Marie , Anhøj Jacob 
Published: October 2012

ObjectivesTo describe experiences with the implementation of global trigger tool (GTT) reviews in five Danish hospitals and to suggest ways to improve the performance of GTT review teams.DesignRetrospective observational study.SettingThe measurement and monitoring of harms are crucial to campaigns to improve the safety of patients. Increasingly, teams use the GTT to review patient records and measure harms in English and non-English-speaking countries. Meanwhile, it is not clear as to how the method performs in such diverse settings.ParticipantsReview teams from five Danish pilot hospitals of the national Danish Safer Hospital Programme.Primary and secondary outcome measuresWe collected harm rates, background and anecdotal information and reported patient safety incidents (PSIs) from five pilot hospitals currently participating in the Danish Safer Hospital Programme. Experienced reviewers categorised harms by type. We plotted harm rates as run-charts and applied rules for the detection of patterns of non-random variation.ResultsThe hospitals differed in size but had similar patient populations and activity. PSIs varied between 3 and 12 per 1000 patient-days. The average harm rate for all hospitals was 60 per 1000 patient-days ranging from 34 to 84. The percentage of harmed patients was 25 and ranged from 18 to 33. Overall, 96% of harms were temporary. Infections, pressure ulcers procedure-related and gastrointestinal problems were common. Teams reported differences in training and review procedures such as the role of the secondary reviewer.ConclusionsWe found substantial variation in harm rates. Differences in training, review procedures and documentation in patient records probably contributed to these variations. Training reviewers as teams, specifying the roles of the different reviewers, training records and a database for findings of reviews may improve the application of the GTT.
Plasma disposition of enrofloxacin following intravenous and intramuscular administration in donkeys
Authors: Sekkin S. , Gokbulut C. , Kum C. , Karademir U. 
Published: October 2012

This study was designed to investigate the plasma disposition and systemic availability of enrofloxacin (ENR) following intramuscular and intravenous administrations. Six donkeys (Equus asinus) were used in this study. The animals were allocated into two groups (intramuscular and intravenous groups). After a 2‐week washout period, the experiment was repeated with the groups reversed according to a two‐phase crossover design. In phase I, group I received intravenously the commercially available injectable solution of ENR at the dose of 5 mg/kg and group II received intramuscularly the same ENR formulation at the same dose rate. Blood samples were collected 1 hour prior to drug administration and various times between 5 minutes and 48 hours post‐treatments. The samples were analysed by high performance liquid chromatography with fluorescence detector. The half‐life and mean residence time of ENR (12.08 hours and 17.85 hours) after intramuscular route were significantly longer compared with intravenous administration (9.54 hours and 7.46 hours, respectively) and these were associated with a flip‐flop phenomenon. A marked proportion of ENR (20–21 per cent) was metabolised to ciprofloxacin (CPR) following both administration routes and the half‐life of CPR paralleled that of the parent drug after intramuscular administration. Mean absorption time was relatively long (10.39 hours), and the bioavailability of ENR was 76.56 per cent after intramuscular route in the donkeys. The plasma concentration is lower after intramuscular administration at a dose rate of 5 mg/kg, and may need a higher dose to provide sufficient plasma concentration in donkeys compared with horses.
ANALYSIS OF ROUND OFF ERRORS WITH REVERSIBILITY TEST AS A DYNAMICAL INDICATOR
Authors: FARANDA DAVIDE , MESTRE MARTÍN FEDERICO , TURCHETTI GIORGIO 
Published: October 2012

We compare the divergence of orbits and the reversibility error for discrete time dynamical systems. These two quantities are used to explore the behavior of the global error induced by round off in the computation of orbits. The similarity of results found for any system we have analyzed suggests the use of the reversibility error, whose computation is straightforward since it does not require the knowledge of the exact orbit, as a dynamical indicator. The statistics of fluctuations induced by round off for an ensemble of initial conditions has been compared with the results obtained in the case of random perturbations. Significant differences are observed in the case of regular orbits due to the correlations of round off error, whereas the results obtained for the chaotic case are nearly the same. Both the reversibility error and the orbit divergence computed for the same number of iterations on the whole phase space provide an insight on the local dynamical properties with a detail comparable with other dynamical indicators based on variational methods such as the finite time maximum Lyapunov characteristic exponent, the mean exponential growth factor of nearby orbits and the smaller alignment index. For 2D symplectic maps, the differentiation between regular and chaotic regions is well full-filled. For 4D symplectic maps, the structure of the resonance web as well as the nearby weakly chaotic regions are accurately described.
Targeting complex embedded architectures by combining the multicore communications API (mcapi) with compile-time virtualisation
Authors: Gray Ian , Audsley Neil C. 
Published: October 2012

Within the domain of embedded systems, hardware architectures are commonly characterised by application-specific heterogeneity. Systems may contain multiple dissimilar processing elements, non-standard memory architectures, and custom hardware elements. The programming of such systems is a considerable challenge, not only because of the need to exploit large degrees of parallelism but also because hardware architectures change from system to system. To solve this problem, this paper proposes the novel combination of a new industry standard for communication across multicore architectures (MCAPI), with a minimal-overhead technique for targeting complex architectures with standard programming languages (Compile-Time Virtualisation).
The Multicore Association have proposed MCAPI as an industry standard for on-chip communications. MCAPI abstracts the on-chip physical communication to provide the application with logical point-to-point unidirectional channels between nodes (software thread, hardware core, etc.). Compile-Time Virtualisation is used to provide an extremely lightweight implementation of MCAPI, that supports a much wider range of architectures than its specification normally considers. Overall, this unique combination enhances programmability by abstracting on-chip communication whilst also exposing critical parts of the target architecture to the programming language.
Divide and recycle
Authors: Benveniste Albert , Bourke Timothy , Caillaud Benoît , Pouzet Marc 
Published: October 2012

Hybrid modelers such as Simulink have become corner stones of embedded systems development. They allow both discrete controllers and their continuous environments to be expressed in a single language. Despite the availability of such tools, there remain a number of issues related to the lack of reproducibility of simulations and to the separation of the continuous part, which has to be exercised by a numerical solver, from the discrete part, which must be guaranteed not to evolve during a step.
Starting from a minimal, yet full-featured, Lustre-like synchronous language, this paper presents a conservative extension where data-flow equations can be mixed with ordinary differential equations (ODEs) with possible reset. A type system is proposed to statically distinguish discrete computations from continuous ones and to ensure that signals are used in their proper domains. We propose a semantics based on non-standard analysis which gives a synchronous interpretation to the whole language, clarifies the discrete/continuous interaction and the treatment of zero-crossings, and also allows the correctness of the type system to be established.
The extended data-flow language is realized through a source-to-source transformation into a synchronous subset, which can then be compiled using existing tools into routines that are both efficient and bounded in their use of memory. These routines are orchestrated with a single off-the-shelf numerical solver using a simple but precise algorithm which treats causally-related cascades of zero-crossings. We have validated the viability of the approach through experiments with the Sundials library.
Lowering overhead in sampling-based execution monitoring and tracing
Authors: Thomas Johnson J. , Fischmeister Sebastian , Kumar Deepak 
Published: October 2012

Debugging is an important phase in the embedded software development cycle because of its high proportion in the overall cost in the product development. Debugging is difficult for real-time applications as such programs are time-sensitive and must meet deadlines in often a resource constrained environment.
A common approach for real-time systems is to monitor the execution instead of stepping through the program, because stepping will usually violate all deadline constraints. We consider a sampling-based approach for monitoring, because of its predictable overhead for the system compared to traditional monitoring. However, the sampling-based approach can easily have high overhead depending on the length of branches and the granularity of the monitoring effort. To reduce this overhead, we instrument the program with markers that will permit us to sample less frequently and thus reduce the overhead.
This leads to the interesting problems of (a) where to place the markers in the code and (b) how to manipulate the markers. While related work investigates the first part, in this work, we investigate the second component of the problem. We investigate different instrumentation schemes and propose two new schemes based on bitvectors that significantly reduce the overhead for sampling-based execution monitoring.
Predictable task migration for locked caches in multi-core systems
Authors: Sarkar Abhik , Mueller Frank , Ramaprasad Harini 
Published: October 2012

Locking cache lines in hard real-time systems is a common means of achieving predictability of cache access behavior and tightening as well as reducing worst case execution time, especially in a multitasking environment. However, cache locking poses a challenge for multi-core hard real-time systems since theoretically optimal scheduling techniques on multi-core architectures assume zero cost for task migration. Tasks with locked cache lines need to proactively migrate these lines before the next invocation of the task. Otherwise, cache locking on multi-core architectures becomes useless as predictability is compromised.
This paper proposes hardware-based push-assisted cache migration as a means to retain locks on cache lines across migrations. We extend the push-assisted migration model with several cache migration techniques to efficiently retain locked cache lines on a bus-based chip multi-processor architecture. We also provide deterministic migration delay bounds that help the scheduler decide which migration technique(s) to utilize to relocate a single or multiple tasks. This information also allows the scheduler to determine feasibility of task migrations, which is critical for the safety of any hard real-time system. Such proactive migration of locked cache lines in multi-cores is unprecedented to our knowledge.
Probabilistic relational reasoning for differential privacy
Authors: Barthe Gilles , Köpf Boris , Olmedo Federico , Zanella Béguelin Santiago 
Published: October 2012

Differential privacy is a notion of confidentiality that protects the privacy of individuals while allowing useful computations on their private data. Deriving differential privacy guarantees for real programs is a difficult and error-prone task that calls for principled approaches and tool support. Approaches based on linear types and static analysis have recently emerged; however, an increasing number of programs achieve privacy using techniques that cannot be analyzed by these approaches. Examples include programs that aim for weaker, approximate differential privacy guarantees, programs that use the Exponential mechanism, and randomized programs that achieve differential privacy without using any standard mechanism. Providing support for reasoning about the privacy of such programs has been an open problem.
We report on CertiPriv, a machine-checked framework for reasoning about differential privacy built on top of the Coq proof assistant. The central component of CertiPriv is a quantitative extension of a probabilistic relational Hoare logic that enables one to derive differential privacy guarantees for programs from first principles. We demonstrate the expressiveness of CertiPriv using a number of examples whose formal analysis is out of the reach of previous techniques. In particular, we provide the first machine-checked proofs of correctness of the Laplacian and Exponential mechanisms and of the privacy of randomized and streaming algorithms from the recent literature.
A compiler and run-time system for network programming languages
Authors: Monsanto Christopher , Foster Nate , Harrison Rob , Walker David 
Published: October 2012

Software-defined networks (SDNs) are a new kind of network architecture in which a controller machine manages a distributed collection of switches by instructing them to install or uninstall packet-forwarding rules and report traffic statistics. The recently formed Open Networking Consortium, whose members include Google, Facebook, Microsoft, Verizon, and others, hopes to use this architecture to transform the way that enterprise and data center networks are implemented.
In this paper, we define a high-level, declarative language, called NetCore, for expressing packet-forwarding policies on SDNs. NetCore is expressive, compositional, and has a formal semantics. To ensure that a majority of packets are processed efficiently on switches---instead of on the controller---we present new compilation algorithms for NetCore and couple them with a new run-time system that issues rule installation commands and traffic-statistics queries to switches. Together, the compiler and run-time system generate efficient rules whenever possible and outperform the simple, manual techniques commonly used to program SDNs today. In addition, the algorithms we develop are generic, assuming only that the packet-matching capabilities available on switches satisfy some basic algebraic laws.
Overall, this paper delivers a new design for a high-level network programming language; an improved set of compiler algorithms; a new run-time system for SDN architectures; the first formal semantics and proofs of correctness in this domain; and an implementation and evaluation that demonstrates the performance benefits over traditional manual techniques.