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This is a copy of the slides presented at the meeting but not formally written up for the volume.
Superparamagnetic iron oxide (SPIO) nanoparticles are prevalent as nanoprobes for molecular magnetic resonance imaging (MRI), providing positive or negative contrast by locally affecting the relaxation of water protons. Fe3O4 nanoparticles are commonly used as a negative MRI contrast agent, implementing various surface functionalization techniques to provide molecular targeting to biological macromolecules. The authors recently demonstrated targeting of cancer antigen 125 (CA125) with differentiable MRI contrast in human ovarian cancer cell lines using monoclonal antibodies covalently conjugated to phospholipid micelle encapsulated 10 nm single crystalline SPIO nanoparticles, demonstrating molecular targeting capabilities via surface functionalization . While molecular targeting of SPIO nanoparticles has been thoroughly demonstrated, the effects of surface modifications have not been studied in regard to proton relaxation. The authors will present spin-lattice (T1) and spin-spin (T2) proton relaxometry of SPIO nanoparticles with varying surface chemistries. The effects of surface modification on T1 and T2 relaxation have not been thoroughly investigated, and results recently reported by the authors indicate a correlation of spin-spin relaxation with SPIO nanoparticle hydrodynamic radius . T1 and T2 relaxometry (Varian 300 MHz NMR) of polyethylene glycol modified (PEGylated) phospholipid micelle encapsulated SPIO nanoparticles and covalently PEGylated SPIO nanoparticles for varying hydrodynamic radii will be presented. These results are of particular interest to molecular imaging applications due to the common practice of SPIO nanoparticle PEGylation to improve biocompatibility. The authors will also present results of magnetic anisotropy studies with respect to proton relaxation by SPIO nanoparticles. Recent work by Roch et al emphasizes the role of magnetic anisotropy in the proton relaxation mechanism of SPIO nanoparticles . The authors have synthesized monodisperse Fe3-xCoxO4 nanoparticles with similar properties to SPIO. Cobalt substitution in SPIO nanoparticles increases the magnetic anisotropy of the SPIO nanoparticles, thus affecting the proton relaxation. The authors will present T1 and T2 relaxometry (Varian 300 MHz NMR) of Fe3-xCoxO4 nanoparticles and corresponding SQUID (superconducting quantum interference device) magnetic anisotropy measurements (Quantum Design, MPMS-7). The results of this study elucidate the role of magnetic anisotropy in the proton relaxation mechanism and demonstrates the feasibility of Fe3-xCoxO4 nanoparticles as a T2 contrast agent.1. Larsen BA et al, Proceedings of the 5th Annual Meeting of Molecular Imaging, 20062. Barker AJ, Larsen BA et al, Proceedings of the ASME SBC, 20063. Roch et al, Journal of Mag Res Imaging 14, pp 94-96, 2001.
Introduction: Emergency health care providers (HCPs) regularly perform difficult medical resuscitations that require complex decision making and action. Critical incident debriefing has been proposed as a mechanism to mitigate the psychological effect of these stressful events and improve both provider and patient outcomes. The purpose of this updated systematic review is to determine if HCPs performing debriefing after critical incidents, compared to no debriefing, improves the outcomes of the HCPs or patients. Methods: We performed a librarian assisted systematic review of OVID Medline, CINAHL, OVID Embase and Google Scholar (January 2006 to February 2017) No restrictions for language were imposed. Two investigators evaluated articles independently for inclusion criteria, quality and data collection. Agreement was measured using the Kappa statistic and quality of the articles were assessed using the Downs and Black evaluation tool. Results: Among the 658 publications identified 16 met inclusion criteria. Participants included physicians, nurses, allied health and learners involved in both adult and pediatric resuscitations. Findings suggest that HCPs view debriefing positively (n=7). One moderate quality study showed that debriefing can enhance medical student and resident knowledge. Several studies (n=8) demonstrated at least some improvement in CPR and intubation related technical skills. Debriefing is also associated with improved short term patient survival but not survival to discharge (n=5). Two studies reported benefits to HCPs mental health as evidenced by improved ability to manage grief and decreased reported symptoms of Post-Traumatic Stress Disorder (PTSD). Conclusion: We found HCPs value debriefing after critical incidents and that debriefing is associated with improved HCP knowledge, skill and well-being. Despite these positive findings, there continues to be limited evidence that debriefing significantly impacts long term patient outcomes. Larger scale higher quality studies are required to further delineate the effect of structured debriefing on patient and provider outcomes.
To summarize and discuss logistic and administrative challenges we encountered during the Benefits of Enhanced Terminal Room (BETR) Disinfection Study and lessons learned that are pertinent to future utilization of ultraviolet (UV) disinfection devices in other hospitals
Multicenter cluster randomized trial
SETTING AND PARTICIPANTS
Nine hospitals in the southeastern United States
All participating hospitals developed systems to implement 4 different strategies for terminal room disinfection. We measured compliance with disinfection strategy, barriers to implementation, and perceptions from nurse managers and environmental services (EVS) supervisors throughout the 28-month trial.
Implementation of enhanced terminal disinfection with UV disinfection devices provides unique challenges, including time pressures from bed control personnel, efficient room identification, negative perceptions from nurse managers, and discharge volume. In the course of the BETR Disinfection Study, we utilized several strategies to overcome these barriers: (1) establishing safety as the priority; (2) improving communication between EVS, bed control, and hospital administration; (3) ensuring availability of necessary resources; and (4) tracking and providing feedback on compliance. Using these strategies, we deployed ultraviolet (UV) disinfection devices in 16,220 (88%) of 18,411 eligible rooms during our trial (median per hospital, 89%; IQR, 86%–92%).
Implementation of enhanced terminal room disinfection strategies using UV devices requires recognition and mitigation of 2 key barriers: (1) timely and accurate identification of rooms that would benefit from enhanced terminal disinfection and (2) overcoming time constraints to allow EVS cleaning staff sufficient time to properly employ enhanced terminal disinfection methods.
Temperature, density and accumulation data were obtained from shallow firn cores, drilled during an overland traverse through a previously unknown part of Dronning Maud Land, East Antarctica. The traverse area is characterised by high mountains that obstruct the ice flow, resulting in a sudden transition from the polar plateau to the coastal region. The spatial variations of potential temperature, near-surface firn density and accumulation suggest that katabatic winds are active in this region. Proxy wind data derived from firn-density profiles confirm that annual mean wind speed is strongly related to the magnitude of the surface slope. The high elevation of the ice sheet south of the mountains makes for a dry, cold climate, in which mass loss owing to sublimation is small and erosion of snow by the wind has a potentially large impact on the surface mass balance. A simple katabatic-wind model is used to explain the variations of accumulation along the traverse line in terms of divergence/convergence of the local transport of drifting snow. The resulting wind- and snowdrift patterns are closely connected to the topography of the ice sheet: ridges are especially sensitive to erosion, while ice streams and other depressions act as collectors of drifting snow.
Whole apples have not been previously implicated in outbreaks of foodborne bacterial illness. We investigated a nationwide listeriosis outbreak associated with caramel apples. We defined an outbreak-associated case as an infection with one or both of two outbreak strains of Listeria monocytogenes highly related by whole-genome multilocus sequence typing (wgMLST) from 1 October 2014 to 1 February 2015. Single-interviewer open-ended interviews identified the source. Outbreak-associated cases were compared with non-outbreak-associated cases and traceback and environmental investigations were performed. We identified 35 outbreak-associated cases in 12 states; 34 (97%) were hospitalized and seven (20%) died. Outbreak-associated ill persons were more likely to have eaten commercially produced, prepackaged caramel apples (odds ratio 326·7, 95% confidence interval 32·2–3314). Environmental samples from the grower's packing facility and distribution-chain whole apples yielded isolates highly related to outbreak isolates by wgMLST. This outbreak highlights the importance of minimizing produce contamination with L. monocytogenes. Investigators should perform single-interviewer open-ended interviews when a food is not readily identified.
This paper briefly describes the principle of operation and science goals of the AMANDA high energy neutrino telescope located at the South Pole, Antarctica. Results from an earlier phase of the telescope, called AMANDA-BIO, demonstrate both reliable operation and the broad astrophysical reach of this device, which includes searches for a variety of sources of ultrahigh energy neutrinos: generic point sources, Gamma-Ray Bursts and diffuse sources. The predicted sensitivity and angular resolution of the telescope were confirmed by studies of atmospheric muon and neutrino backgrounds. We also report on the status of the analysis from AMANDA-II, a larger version with far greater capabilities. At this stage of analysis, details of the ice properties and other systematic uncertainties of the AMANDA-II telescope are under study, but we have made progress toward critical science objectives. In particular, we present the first preliminary flux limits from AMANDA-II on the search for continuous emission from astrophysical point sources, and report on the search for correlated neutrino emission from Gamma Ray Bursts detected by BATSE before decommissioning in May 2000. During the next two years, we expect to exploit the full potential of AMANDA-II with the installation of a new data acquisition system that records full waveforms from the in-ice optical sensors.
We studied nestedness and its relationships with beta-diversity in flea communities harboured by three closely related rodent species (Rhabdomys pumilio, Rhabdomys intermedius, Rhabdomys dilectus) at two spatial scales (within and among host populations) in South Africa and asked (a) whether variation in species composition of flea communities within and among host populations follows a non-random pattern; if yes, (b) what are the contributions of nestedness and species turnover to dissimilarity (= beta-diversity) among flea communities at the two scales; and (c) do the degree of nestedness and its contribution to beta-diversity differ among host species (social vs solitary) and between scales. We found that nestedness in flea assemblages was more pronounced (a) in social than solitary host species and (b) at lower (among host individuals within populations) than at higher scale (among host populations). We also found that higher degree of nestedness was associated with its higher contribution to beta-diversity. Our findings support earlier ideas that parasite community structure results from the processes of parasite accumulation by hosts rather than from the processes acting within parasite communities.
Leaf mass per area (MA) is a central ecological trait that is intercorrelated with leaf life span, photosynthetic rate, nutrient concentration, and palatability to herbivores. These coordinated variables form a globally convergent leaf economics spectrum, which represents a general continuum running from rapid resource acquisition to maximized resource retention. Leaf economics are little studied in ancient ecosystems because they cannot be directly measured from leaf fossils. Here we use a large extant data set (65 sites; 667 species-site pairs) to develop a new, easily measured scaling relationship between petiole width and leaf mass, normalized for leaf area; this enables MA estimation for fossil leaves from petiole width and leaf area, two variables that are commonly measurable in leaf compression floras. The calibration data are restricted to woody angiosperms exclusive of monocots, but a preliminary data set (25 species) suggests that broad-leaved gymnosperms exhibit a similar scaling. Application to two well-studied, classic Eocene floras demonstrates that MA can be quantified in fossil assemblages. First, our results are consistent with predictions from paleobotanical and paleoclimatic studies of these floras. We found exclusively low-MA species from Republic (Washington, U.S.A., 49 Ma), a humid, warm-temperate flora with a strong deciduous component among the angiosperms, and a wide MA range in a seasonally dry, warm-temperate flora from the Green River Formation at Bonanza (Utah, U.S.A., 47 Ma), presumed to comprise a mix of short and long leaf life spans. Second, reconstructed MA in the fossil species is negatively correlated with levels of insect herbivory, whether measured as the proportion of leaves with insect damage, the proportion of leaf area removed by herbivores, or the diversity of insect-damage morphotypes. These correlations are consistent with herbivory observations in extant floras and they reflect fundamental trade-offs in plant-herbivore associations. Our results indicate that several key aspects of plant and plant-animal ecology can now be quantified in the fossil record and demonstrate that herbivory has helped shape the evolution of leaf structure for millions of years.
Although scholarly consensus suggests that dissent causes repression, the behaviors are endogenous: governments and dissidents act in expectation of each other’s behavior. Empirical studies have not accounted well for this endogeneity. We argue that preventive aspects of repression meaningfully affect the relationship between observed dissent and repression. When governments use preventive repression, the best response to dissent that does occur is unclear; observed dissent does not meaningfully predict responsive repression. By contrast, governments that do not engage in ex ante repression will be more likely to do it ex post. We follow U.S. voting scholarship and propose a new instrument to model the endogeneity: rainfall. We couple rainfall data in African provinces and U.S. states with data on dissent and repression and find that dissent fails to have a significant effect on responsive repression in states that engage in preventive repression.
Language-specific orthography (i.e., letters or bigrams that exist in only one language) is known to facilitate language membership recognition. Yet the contribution of continuous sublexical and lexical statistics to language membership decisions during visual word processing is unknown. Here, we used pseudo-words to investigate whether continuous sublexical and lexical statistics bias explicit language decisions (Experiment 1) and language attribution during naming (Experiment 2). We also asked whether continuous statistics would have an effect in the presence of orthographic markers. Language attribution in both experiments was influenced by lexical neighborhood size differences between languages, even in presence of orthographic markers. Sublexical frequencies of occurrence affected reaction times only for unmarked pseudo-words in both experiments, with greater effects in naming. Our results indicate that bilinguals rely on continuous language-specific statistics at sublexical and lexical levels to infer language membership. Implications are discussed with respect to models of bilingual visual word recognition.
In this pilot study, we evaluate an algorithm that uses predictive clinical and laboratory parameters to differentiate between patients with hospital-acquired infection (HAI) and patients without HAI. Seventy-four percent of the studied population of surgical patients could be reliably (negative predictive value of 98%) excluded from detailed assessment by the infection control practitioner.
Surveillance of hospital-acquired infections can be approximated by repeated surveys that are performed in a standardized, cost-effective manner. We developed an integrated software system for serial electronic hospital-wide point prevalence surveys using algorithms that proved highly sensitive and specific over a 5-year period in a large university medical center.
We present a novel multilayered architecture for memristive devices which provides an alternative to conventional conductive filament switching. In conventional resistive switching, conductive filaments form and extend stochastically under applied electrical bias, with longer filaments being subjected to magnified electric fields that amplify their growth rate, producing a spatially localized and highly non-uniform conduction front of filaments. This produces devices with large variations in resistive and capacitive properties that are difficult to tune. Here, we simulate a multilayered device structure with alternating ionic mobility that predicts the development of a quasi-uniform conduction front which amplifies memcapacitive properties of the device and reduces device-to-device variability. Furthermore, this novel structure is predicted to enable fine-tuned control of switching events, an important property for analog (multibit) memory and neuromorphic computing applications.
Historically significant public events sometimes organize autobiographical memory, acting as temporal landmarks and providing the thematic content which defines the lifetime periods they spawn (Brown and Lee, 2010; Brown, Lee, Krslak, et al., 2009). We begin this chapter by briefly reviewing a research program that has demonstrated the existence of these historically defined autobiographical periods and that has allowed us to identify the conditions that bring them about. In this section, we also present data from four samples of World War II-generation adults, data which prove that historically defined autobiographical periods endure over time. Next, we consider the theoretical implications of these findings. In particular, we introduce a new approach to autobiographical memory called the transition theory. This approach assumes that autobiographical memory is organized by transitional events and that these transitions can be self-initiated or externally imposed. On this view, historically defined autobiographical periods are formed by externally imposed transitions. We develop this point in the third and final section of this chapter.
The living-in-history project
War, terrorism, and natural disasters can have far-reaching effects on the lives of those involved (Blaikie, Cannon, Davis, et al., 1994; Levy and Sidel, 1997; McNally, 2003). Collective memory for extraordinary social events can also play a critical role in the construction and maintenance of group identities and in the persistence of intergroup hostility (Bar-Tal, 2007; Cairns and Roe, 2003; Halbwachs, 1992; Hirst, Cuc, and Wohl, this volume). Our project examined the mnemonic impact of public events at the individual level in order to understand when autobiographical memory and historical events can become intertwined. More specifically, the program of research was undertaken to determine whether public events affect the organization of autobiographical memory and to specify the conditions that result in the creation of historically defined autobiographical periods. We were interested in this issue because we suspected that people who had “lived in history” might understand the recent past in a different way than those who had not, and that this understanding might ground current and future beliefs about that past. For this reason, we wanted to identify public events that caused people to “live in history” and to distinguish these epoch-defining events from other significant public events.
In this study, we have developed and characterized two previously unstudied alkoxysilane surface chemistries for use with superparamagnetic iron oxide (SPIO) nanoparticles as a magnetic resonance imaging contrast agent. We modified superparamagnetic iron oxide nanoparticles (SPIO) using aminopropyl triethoxysilane and two analogous alkoxysilanes, aminopropyl dimethylethoxysilane and aminopropyl methyldiethoxysilane, to compare a mono- and dialkoxysilane, respectively, to a more commonly used trialkoxysilane as two new SPIO surface chemistries capable of forming ultrathin functional surface coatings. The ligand densities of the mono- and dialkoxysilane-modified SPIO produced in this study are consistent with near monolayers of ligands on the SPIO surface. We studied the chemical stability of the mono-, di-, and trialkoxysilane-modified SPIO in neutral and acidic media to evaluate the viability of these surface chemistries for use in long-term intracellular applications. The mono- and dialkoxysilane-modified SPIO demonstrate comparable chemical stability to the trialkoxysilane-modified SPIO, indicating that the mono- and dialkoxysilane are both viable new SPIO surface chemistries for future applications requiring minimally thick alkoxysilane surface coatings.
As in the past, the primary activity of the IAU Working Group on Cartographic Coordinates and Rotational Elements has been to prepare and publish a triennial (“2009”) report containing current recommendations for models for Solar System bodies (Archinal et al. (2011a)). The authors are B. A. Archinal, M. F. A'Hearn, E. Bowell, A. Conrad, G. J. Consolmagno, R. Courtin, T. Fukushima, D. Hestroffer, J. L. Hilton, G. A. Krasinsky, G. Neumann, J. Oberst, P. K. Seidelmann, P. Stooke, D. J. Tholen, P. C. Thomas, and I. P. Williams. An erratum to the “2006” and “2009” reports has also been published (Archinal et al. (2011b)). Below we briefly summarize the contents of the 2009 report, a plan to consider requests for new recommendations more often than every three years, three general recommendations by the WG to the planetary community, other WG activities, and plans for our next report.
In contrast to the GATT, both the TBT and the SPS Agreement explicitly mention ‘processes and production methods’. This chapter therefore explores whether PPM measures have a special legal status under both agreements. Despite the explicit reference, however, it is unclear whether both agreements cover all types of PPM measures, or whether coverage is limited to incorporated PPMs. The question arises if the GATT remains of any actual relevance, since a large part of NPA measures could fall within the scope of the TBT and the SPS Agreements as lex specialis. While this issue is very complex and contentious for the TBT Agreement, section 6.3 explains that the SPS Agreement covers only incorporated PPMs and is therefore of little importance to this work. The TBT Agreement, on the other hand, relates to a specific subject matter, namely, technical barriers to trade, and therefore cannot cover all PPM, let alone NPA, measures. In addition, the relationship between the TBT Agreement and the GATT in the case of conflicting provisions is not entirely clear. The following section argues that the TBT Agreement is applicable to an important group of technical norms, namely, labelling regulation, even if these concern unincorporated PPMs. Its focus is on the consideration of consumer information as a legitimate objective highly relevant to labelling requirements concerning unincorporated PPMs.
The TBT Agreement and PPMs
Given the lack of international harmonization, technical standards and regulation have the potential to create substantial non-tariff barriers to international trade.