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Hospital environmental surfaces are frequently contaminated by microorganisms. However, the causal mechanism of bacterial contamination of the environment as a source of transmission is still debated. This prospective study was performed to characterize the nature of multidrug-resistant organism (MDRO) transmission between the environment and patients using standard microbiological and molecular techniques.
Prospective cohort study at 2 academic medical centers.
A prospective multicenter study to characterize the nature of bacterial transfer events between patients and environmental surfaces in rooms that previously housed patients with 1 of 4 ‘marker’ MDROs: methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridium difficile, and MDR Acinetobacter baumannii. Environmental and patient microbiological samples were obtained on admission into a freshly disinfected inpatient room. Repeat samples from room surfaces and patients were taken on days 3 and 7 and each week the patient stayed in the same room. The bacterial identity, antibiotic susceptibility, and molecular sequences were compared between organisms found in the environment samples and patient sources.
We enrolled 80 patient–room admissions; 9 of these patients (11.3%) were asymptomatically colonized with MDROs at study entry. Hospital room surfaces were contaminated with MDROs despite terminal disinfection in 44 cases (55%). Microbiological Bacterial Transfer events either to the patient, the environment, or both occurred in 12 patient encounters (18.5%) from the microbiologically evaluable cohort.
Microbiological Bacterial Transfer events between patients and the environment were observed in 18.5% of patient encounters and occurred early in the admission. This study suggests that research on prevention methods beyond the standard practice of room disinfection at the end of a patient’s stay is needed to better prevent acquisition of MDROs through the environment.
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) represent a disease continuum with common genetic causes and molecular pathology. We recently identified mutations in the T-cell restricted intracellular antigen-1 (TIA1) protein as a cause of ALS +/− FTD. TIA1 is an RNA-binding protein containing a low complexity domain (LCD) that promotes the assembly of membrane-less organelles, such as stress granules (SG). Whole exome sequencing of two family members with fALS/FTD revealed a novel missense mutation in the TIA1 LCD (P362L). Subsequent screening identified five more TIA1 mutations in six additional ALS patients, but none in controls. All mutation carriers presented with weakness, behavioral abnormalities or language impairments and had a final diagnosis of ALS +/− FTD. Autopsy on five TIA1 mutation carriers showed widespread neurodegeneration with TDP-43 pathology. Round eosinophilic inclusions in lower motor neurons were a consistent feature. Cellular assays revealed abnormal SG dynamics in the presence of TIA1 mutations. In summary, missense mutations in the LCD of TIA1 are a newly recognized cause of ALS/FTD with TDP-43 pathology and strengthen the role of RNA metabolism in the pathogenesis in this disease.
Introduction: Situational awareness (SA) is essential for maintenance of scene safety and effective resource allocation in mass casualty incidents (MCI). Unmanned aerial vehicles (UAV) can potentially enhance SA with real-time visual feedback during chaotic and evolving or inaccessible events. The purpose of this study was to test the ability of paramedics to use UAV video from a simulated MCI to identify scene hazards, initiate patient triage, and designate key operational locations. Methods: A simulated MCI, including fifteen patients of varying acuity (blast type injuries), plus four hazards, was created on a college campus. The scene was surveyed by UAV capturing video of all patients, hazards, surrounding buildings and streets. Attendees of a provincial paramedic meeting were invited to participate. Participants received a lecture on SALT Triage and the principles of MCI scene management. Next, they watched the UAV video footage. Participants were directed to sort patients according to SALT Triage step one, identify injuries, and localize the patients within the campus. Additionally, they were asked to select a start point for SALT Triage step two, identify and locate hazards, and designate locations for an Incident Command Post, Treatment Area, Transport Area and Access/Egress routes. Summary statistics were performed and a linear regression model was used to assess relationships between demographic variables and both patient triage and localization. Results: Ninety-six individuals participated. Mean age was 35 years (SD 11), 46% (44) were female, and 49% (47) were Primary Care Paramedics. Most participants (80 (84%)) correctly sorted at least 12 of 15 patients. Increased age was associated with decreased triage accuracy [-0.04(-0.07,-0.01);p=0.031]. Fifty-two (54%) were able to localize 12 or more of the 15 patients to a 27x 20m grid area. Advanced paramedic certification, and local residency were associated with improved patient localization [2.47(0.23,4.72);p=0.031], [-3.36(-5.61,-1.1);p=0.004]. The majority of participants (78 (81%)) chose an acceptable location to start SALT triage step two and 84% (80) identified at least three of four hazards. Approximately half (53 (55%)) of participants designated four or more of five key operational areas in appropriate locations. Conclusion: This study demonstrates the potential of UAV technology to remotely provide emergency responders with SA in a MCI. Additional research is required to further investigate optimal strategies to deploy UAVs in this context.
Although Saturn's broad A, B, and C rings epitomize the concept of “planetary rings” in the minds of most people, much of our detailed knowledge of ring dynamics has come from the investigation of smaller-scale features such as density and bending waves, the numerous narrow gaps and their embedded ringlets, and the sharp edges which often demarcate various ring regions. In the case of Uranus, almost all of the ring mass is in the form of narrow rings. Narrow ringlets and gaps, and their associated sharp edges (including those of broad rings) form the subject of this chapter, along with the dynamical theories their study has spawned and the puzzles that continue to surround them.
Examples of several narrow gaps and ringlets in Saturn's rings, as well as the very prominent sharp outer edge of the B ring, are shown in Figure 11.1, from French et al. (2016b). Here one can see a total of eight narrow gaps in the region known as the Cassini Division, ranging in width from 5 km to 360 km, as well as four narrow ringlets. At least six more narrow gaps are found in the outer A ring and in the C ring, while three additional narrow ringlets occur in the C ring. The present chapter will cover all of these features, as well as the ten narrow Uranian rings. Recently a pair of narrow, dense rings has been discovered around the centaur object, Chariklo (Braga-Ribas et al., 2014). These are discussed separately in Chapter 7. We also do not discuss the more tenuous and dusty Jovian and Neptunian ring systems, nor the dusty ringlets found at Saturn and Uranus, all of which are covered in Chapter 12. The complex and unique F ring is described in Chapter 13.
We begin with a short overview of the relevant observations and their limitations in Section 11.2, before reviewing the kinematics, systematic width variations and internal structure of narrow ringlets in Section 11.3. In Section 11.4 we discuss the gaps in Saturn's rings, including searches for any embedded satellites. Section 11.5 deals with individual ringlet and gap edges, especially those that are controlled by resonances with external satellites and those that show evidence for local perturbations by unseen, embedded objects.
Advances in infrared astronomy and in computing power have recently opened up an interesting area of the solar system for dynamical exploration. The survey of the sky made by The Infrared Astronomical Satellite (IRAS) in 1983 revealed the complex structure of the zodiacal dust cloud. We now know the inclination and nodes of the plane of symmetry of the cloud with respect to the ecliptic and we have evidence that the cloud is not rotationally symmetric with respect to the Sun. Of even more interest is the discovery by IRAS of prominent dust bands that circle the Sun in planes near-parallel to the ecliptic. In 1984, we suggested (Dermott et al., Nature, 312, 505-509) that the solar system dust bands discovered by IRAS are produced by the gradual comminution of the asteroids in the major Hirayama asteroid families. The confirmation of this hypothesis has involved: (1) The development of a new secular perturbation theory that includes the effects of Poynting-Robertson light drag on the evolution of the dust particle orbits; (2) The production of a new high resolution Zodiacal History File by IPAC (the Infrared Processing and Analysis Center at Caltech); (3) The development of the SIMUL code: a three-dimensional numerical model that allows the calculation of the thermal flux produced by any particular distribution of dust particle orbits. SIMUL includes the effects of planetary perturbations and PR drag on the dust particle orbits and reproduces the exact viewing geometry of the IRAS telescope. We report that these tools allow us to account in detail for the observed structure of the dust bands. They also allow us to show that there is evidence in the IRAS data for the transport of asteroidal dust from the main belt to the Earth by Poynting-Robertson light drag.
Introduction: Special Care Home (SCH) residents require supervision for activities of daily living but not regular nursing care. Emergency Department (ED) use by seniors in SCHs is poorly studied. A recent study in Nova Scotia found seniors represented over 20% of ED visits. We studied SCH resident ED visits in a community with a population of 30,000 aged over 65 years and with 785 SCH beds, to define reasons for ED visits to a tertiary ED, and if these could be avoided. Methods: We performed a retrospective chart review of SCH residents’ visits to an ED (SCH-ED) which has 56,000 total ED (TED) visits over one year. Reasons for visit, admission data, and avoidability were collected. A geriatrician and ED physician independently reviewed visits. Initial disagreement on avoidability (27%) was adjudicated through case discussion. Results: Demographic data revealed 344 ED visits by 111 SCH residents over one year; 37% of visits resulted in admission. 13.9% of residents visited the ED on at least one occasion (average 3.1 visits); mean age 78.4 years; female 66.7%; ambulance arrival 91.0%. The three most common chief complaints were shortness of breath, weakness and abdominal pain. Most SCH-ED visits were Canadian Triage and Acuity Scale (CTAS) Level 3 (63.4%, TED 53.3%). Of CTAS Level 3 visits, 35.3% were admitted (TED 12.9%). SCH-ED visits were avoidable in 40.6% of cases. Gastrointestinal (18%), pain (16.5%), falls, functional decline or injury (14%) and respiratory (12%) were the most common avoidable diagnostic groups, accounting for 57% of total SCH visits. Conclusion: ED visits by SCH residents demonstrated increased acuity and admission rates with a high number of repeat visits. Of all SCH-ED visits, 40% were potentially avoidable. Further study may determine if improved community services reduces ED visits or hospital admission. Gastrointestinal, respiratory, falls and pain diagnoses may be important areas of focus.
Previous discussions of the origin of the zodiacal cloud have attempted to distinguish between an asteroidal and a cometary source on the basis of collisional dynamics, that is, by calculating the rates of production and destruction of particles from the two possible sources. The uncertainties in these calculations are too large to permit a useful conclusion. The recognition that the solar system dust bands discovered by IRAS are probably produced by the gradual comminution of the asteroids in the major Hirayama asteroid families may allow us to estimate, with comparative confidence, the contribution to the zodiacal cloud of the asteroid belt as whole.
We describe a model for first stage electron acceleration based on quasi-linear interaction with Langmuir waves. The acceleration takes place in a MHD-unstable plasma region (length L, volume V) that contains many microscopically unstable current layers, which act as (quasi-stationary) sources of Langmuir waves, Figure 1. Our work does not depend on the details of the generation mechanism for Langmuir waves, nor on the details of the MHD instability. For the latter, one could think of multiple tearing instabilities.
The Deep Space Network (DSN) [operated by JPL under contract to the National Aeronautics and Space Administration] is implementing a Very Long Baseline Interferometry (VLBI) capability at DSS 63 (Spain), DSS 14 (California, USA), and DSS 43 (Australia) to support the navigation requirements of planetary space missions. The early development work for this system has already demonstrated the capability of measuring UT1 with a formal accuracy as low as 0.6 msec with only 6 hours of data. Further, a radio astrometric catalog of approximately 45 sources whose positions are known to better than has been constructed. In addition to these measurements, this paper describes the characteristics and anticipated performance of the complete VLBI system being implemented within the DSN for operational use in mid-1979. In particular, one of the capabilities of this system will be the measurement of UT1 and polar motion at weekly intervals. Although the navigation accuracy requirement is only 50 cm for the Voyager mission, this system should be capable of delivering UT1 and polar motion determinations with decimeter accuracy if it is operated at maximum performance. An additional requirement of this operational system is that it have the capability of providing these results within 24 hours of the actual observations.
Background: Altered mesenteric perfusion may be a contributor to the development of necrotising enterocolitis in patients with hypoplastic left heart syndrome. The goal of this study was to document mesenteric flow patterns in patients with hypoplastic left heart syndrome pre- and post-hybrid procedure. Methods: A prospective study on all patients with hypoplatic left heart syndrome undergoing the hybrid procedure was conducted. Doppler ultrasound analysis of the coeliac and superior mesenteric artery was performed. Results: A total of 13 patients were evaluated. There was a significant difference in the coeliac artery effective velocity-time intergral pre- and post-hybrid procedure (8.69±3.84 versus 12.51±4.95 cm, respectively). There were significant differences in the superior mesenteric artery antegrade velocity-time integral pre- and post-hybrid procedure (6.86±2.45 versus 10.52±2.64 cm, respectively) and superior mesenteric artery effective velocity-time integral pre- and post-hybrid procedure (6.22±2.68 versus 9.73±2.73 cm, respectively). There were no significant differences between the coeliac and superior mesenteric artery Doppler indices in the pre-hybrid procedure; there were, however, significant differences in the post-hybrid procedure between coeliac and superior mesenteric artery antegrade velocity-time integral (13.8 2±5.60 versus 10.52±2.64 cm, respectively) and effective velocity-time integral (13.04±4.71 versus 9.73±2.73 cm, respectively). Conclusion: Doppler mesenteric indices of perfusion improve in patients with hypoplastic left heart syndrome after the hybrid procedure; however, there appears to be preferential flow to the coeliac artery versus the superior mesenteric artery in these patients post-procedure.
Data were extracted from the case records of UK patients admitted with laboratory-confirmed influenza A(H1N1)pdm09. White and non-White patients were characterized by age, sex, socioeconomic status, pandemic wave and indicators of pre-morbid health status. Logistic regression examined differences by ethnicity in patient characteristics, care pathway and clinical outcomes; multivariable models controlled for potential confounders. Whites (n = 630) and non-Whites (n = 510) differed by age, socioeconomic status, pandemic wave of admission, pregnancy, recorded obesity, previous and current smoking, and presence of chronic obstructive pulmonary disease. After adjustment for a priori confounders non-Whites were less likely to have received pre-admission antibiotics [adjusted odds ratio (aOR) 0·43, 95% confidence interval (CI) 0·28–0·68, P < 0·001) but more likely to receive antiviral drugs as in-patients (aOR 1·53, 95% CI 1·08–2·18, P = 0·018). However, there were no significant differences by ethnicity in delayed admission, severity at presentation for admission, or likelihood of severe outcome.
At the post-closure stage of a geological disposal facility for higher activity radioactive waste several species of gas are likely to be generated in the near-field environment. These could alter the sealing and chemical properties of the bentonite buffer and the local geochemical environment significantly. The authors' attempt to simulate multicomponent gas flow through variably saturated porous media is presented. Governing equations have been developed for a reactive gas-flow model to simulate the thermo-hydro-gas-chemical-mechanical behaviour, with specific reference to the performance of highly compacted bentonite buffer subjected to repository gas generation and migration. The developed equations have been included in the bespoke numerical model COMPASS and some generic simulations are also presented. The model presented extends current capability to assess buffer performance.
In the wake of the 2008 election, disgruntled conservatives organized opposition to President Obama's policies under a new movement dubbed the Tea Party. As an emerging force in American politics, we seek to understand who supports the Tea Party and the political attitudes these individuals hold. Using a nationally representative survey of respondents during the 2010 midterm elections, we examine whether the emerging narrative surrounding the Tea Party is accurate. The survey included a novel embedded experiment designed to investigate claims that animosity toward racial minorities drives Tea Party opposition to welfare. We find support for the contention that the Tea Party is predominately white, male, conservative, and strongly opposed to tax increases. Tea Party supporters, however, are not simply libertarians. In spite of appeals to freedom and liberty common in Tea Party rhetoric, a strong authoritarian pulse exists among its most ardent supporters. Furthermore, although we find evidence that racial resentment colors Tea Party members' judgments about government aid to the poor, racial animus does not appear to be the primary force behind their opposition to government aid. Lastly, we uncover some evidence of heterogeneity within the movement, with a small minority of Tea Party supporters voicing less-extreme political attitudes and evincing a rejection of negative racial stereotypes.
It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is the most adaptable to change.
The sections in this chapter deal with a common set of topics: horizontal consolidation, merger and acquisition (M&A), advantages of size, economies of scale and scope, diversification, and industry concentration. These topics all interrelate around the fundamental issue in industrial organization: how best to organize firms and markets in order to achieve optimal economic performance?
Consolidation has been rampant in most sectors of the healthcare industry since the 1980s and 1990s. Indeed, the industry was the second most active in terms of M&A activity (behind finance) between 2008 and 2009. In the pharmaceutical sector, the prior decades had been a time of growth and consolidation, as companies leveraged both size and scale in bringing drugs to market. The current landscape, however, is one of new challenges requiring new approaches to their solution. Companies are faced with internal pressures of declining pipeline productivity and compressed timelines, external pressures of patent expiry and pricing, and the uncertain implications of healthcare reform. Accompanying this evolution of challenges has been an evolution in the strategic approaches taken by pharmaceutical companies to best position themselves for success in the upcoming years.
Bacteriophytochromes (Bphs) are red-light photoreceptors found in photosynthetic and non-photosynthetic bacteria that have been engineered into infrared fluorescent protein markers. Bphs are composed of a photosensory module that is covalently linked to an effector/regulatory module, usually a histidine kinase (HK) domain. Light-induced, global structural changes are proposed to originate within the covalently attached biliverdin chromophore, a linear tetrapyrrole, and propagate through the protein. Bphs undergo reversible photoconversion between two distinct red and far-red light absorbing states, denoted Pr and Pfr respectively. For most Bphs, Pr is the dark-adapted state. The energy dissipated during Pr/Pfr photoconversion is proposed to directly impact the infrared fluorescence quantum yield. At this time, only structures of three different Bphs have been published, all of truncated proteins in their respective dark-adapted states. We have utilized scanning probe microscopy (SPM) to investigate the structure of intact Bphs in the light-adapted state in order to gain new insight into the mechanism of photoconversion and fluorescence. Scanning tunneling microscopy (STM) analysis of a pair of Bphs from photosynthetic bacterium R. palustris, RpBphP2 (P2) and RpBphP3 (P3) in their light-adapted states is presented in these proceedings. The concentration of the depositing protein has a key role in the molecular arrangements observed on the highly-ordered pyrolytic graphite (HOPG) surface. For example, at a high protein concentration, a hexagonal lattice of Bphs is observed by STM on a HOPG surface. Upon dilution, the photoreceptors self-organize into fiber-like structures on the surface. In these fibers, the dimer interface and the individual domains of the Bphs can be assigned and directly compared to a structural model of the intact, full-length proteins. In summary, SPM has potential to be an effective method for gaining new insight into Bph structure and dynamics.
Echocardiography detects a greater prevalence of rheumatic heart disease than heart auscultation. Echocardiographic screening for rheumatic heart disease combined with secondary prophylaxis may potentially prevent severe rheumatic heart disease in high-risk populations. We aimed to determine the prevalence of rheumatic heart disease in children from an urban New Zealand population at high risk for acute rheumatic fever.
Methods and results
To optimise accurate diagnosis of rheumatic heart disease, we utilised a two-step model. Portable echocardiography was conducted on 1142 predominantly Māori and Pacific children aged 10–13 years. Children with an abnormal screening echocardiogram underwent clinical assessment by a paediatric cardiologist together with hospital-based echocardiography. Rheumatic heart disease was then classified as definite, probable, or possible. Portable echocardiography identified changes suggestive of rheumatic heart disease in 95 (8.3%) of 1142 children, which reduced to 59 (5.2%) after cardiology assessment. The prevalence of definite and probable rheumatic heart disease was 26.0 of 1000, with 95% confidence intervals ranging from 12.6 to 39.4. Portable echocardiography overdiagnosed rheumatic heart disease with physiological valve regurgitation diagnosed in 28 children. A total of 30 children (2.6%) had non-rheumatic cardiac abnormalities, 11 of whom had minor congenital mitral valve anomalies.
We found high rates of undetected rheumatic heart disease in this high-risk population. Rheumatic heart disease screening has resource implications with cardiology evaluation required for accurate diagnosis. Echocardiographic screening for rheumatic heart disease may overdiagnose rheumatic heart disease unless congenital mitral valve anomalies and physiological regurgitation are excluded.