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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.
We examined morphological awareness and reading achievement in university students in two ways. First, students with and without a self-reported history of reading difficulties were compared on word reading and text reading achievement, and on the reading-related skills of morphological awareness, orthographic processing, and phonological processing. Second, the unique contribution of morphological awareness to reading achievement was examined for a larger sample of first-year university students. Students with a self-reported history of reading difficulties (n = 54) showed moderate to large gaps in each area of reading achievement, and timed reading comprehension appeared more severely impaired than word-reading efficiency. These students had a deficit in morphological awareness that persisted even when (a) phonological awareness and orthographic processing skills, or (b) word-reading accuracy were statistically controlled. In the larger first-year sample (N = 211), morphological awareness contributed to variance in word reading beyond that accounted for by phonological awareness and orthographic processing. Furthermore, of the reading-related skills, only morphological awareness made a unique contribution to reading comprehension beyond variance accounted for by word reading. Taken together, these results demonstrate that morphological awareness makes unique contributions to university students’ reading achievement and is an additional difficulty for students with a self-reported history of reading difficulties.
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.
Host–parasite dynamics can play a fundamental role in both the establishment success of invasive species and their impact on native wildlife. The net impact of parasites depends on their capacity to switch effectively between native and invasive hosts. Here we explore host-switching, spatial patterns and simple fitness measures in a slow-expanding invasion: the invasion of Asian house geckos (Hemidactylus frenatus) from urban areas into bushland in Northeast Australia. In bushland close to urban edges, H. frenatus co-occurs with, and at many sites now greatly out-numbers, native geckos. We measured prevalence and intensity of Geckobia mites (introduced with H. frenatus), and Waddycephalus (a native pentastome). We recorded a new invasive mite species, and several new host associations for native mites and geckos, but we found no evidence of mite transmission between native and invasive geckos. In contrast, native Waddycephalus nymphs were commonly present in H. frenatus, demonstrating this parasite's capacity to utilize H. frenatus as a novel host. Prevalence of mites on H. frenatus decreased with distance from the urban edge, suggesting parasite release towards the invasion front; however, we found no evidence that mites affect H. frenatus body condition or lifespan. Waddycephalus was present at low prevalence in bushland sites and, although its presence did not affect host body condition, our data suggest that it may reduce host survival. The high relative density of H. frenatus at our sites, and their capacity to harbour Waddycephalus, suggests that there may be impacts on native geckos and snakes through parasite spillback.
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.
Early recognition of an acute myocardial infarction (AMI) can increase the patient’s likelihood of survival. As the first point of contact for patients accessing medical care through emergency services, emergency medical dispatchers (EMDs) represent the earliest potential identification point for AMIs. The objective of the study was to determine how AMI cases were coded and prioritized at the dispatch point, and also to describe the distribution of these cases by patient age and gender.
No studies currently exist that describe the EMD’s ability to correctly triage AMIs into Advanced Life Support (ALS) response tiers.
The retrospective descriptive study utilized data from three sources: emergency medical dispatch, Emergency Medical Services (EMS), and emergency departments (EDs)/hospitals. The primary outcome measure was the distributions of AMI cases, as categorized by Chief Complaint Protocol, dispatch priority code and level, and patient age and gender. The EMS and ED/hospital data came from the Utah Department of Health (UDoH), Salt Lake City, Utah. Dispatch data came from two emergency communication centers covering the entirety of Salt Lake City and Salt Lake County, Utah.
Overall, 89.9% of all the AMIs (n=606) were coded in one of the three highest dispatch priority levels, all of which call for ALS response (called CHARLIE, DELTA, and ECHO in the studied system). The percentage of AMIs significantly increased for patients aged 35 years and older, and varied significantly by gender, dispatch level, and chief complaint. A total of 85.7% of all deaths occurred among patients aged 55 years and older, and 88.9% of the deaths were handled in the ALS-recommended priority levels.
Acute myocardial infarctions may present as a variety of clinical symptoms, and the study findings demonstrated that more than one-half were identified as having chief complaints of Chest Pain or Breathing Problems at the dispatch point, followed by Sick Person and Unconscious/Fainting. The 35-year age cutoff for assignment to higher priority levels is strongly supported. The Falls and Sick Person Protocols offer opportunities to capture atypical AMI presentations.
ClawsonJJ, GardettI, ScottG, FivazC, BarronT, BroadbentM, OlolaC. Hospital-Confirmed Acute Myocardial Infarction: Prehospital Identification Using the Medical Priority Dispatch System. Prehosp Disaster Med. 2018;33(1):29–35.
To examine the comparability of fruit and vegetable (F&V) intake data in the USA from 2001 to 2014 between data acquired from two national data collection programmes.
Cross-sectional analysis. Linear regression models estimated trends in daily per capita intake of total F&V. Pooled differences in intake of individual F&V (n 109) were examined by processing form (fresh, frozen, canned, dried and juice).
What We Eat in America (WWEIA, 2001–2014) and Loss-Adjusted Food Availability data series (LAFA, 2001–2014).
No temporal trends were observed in daily per capita intake of total F&V from 2001 to 2014 using WWEIA and LAFA. Modest differences between WWEIA and LAFA were observed in mean pooled intake of most individual F&V.
WWEIA and LAFA produced similar estimates of F&V intake. However, WWEIA may be best suited for monitoring intake at the national level because it allows for the identification of individual F&V in foods with multiple ingredients, and it is structured for sub-population analysis and covariate control. LAFA does retain advantages for other research protocols, specifically by providing the only nationally representative estimates of food losses at various points in the food system, which makes it useful for examining the adequacy of the food supply at the agricultural, retail and consumer levels.
The balsam twig aphid Mindarus abietinus Koch (Hemiptera: Aphididae) is a major pest of economic importance for the Christmas tree industry. Global warming during the 21st century could potentially increase local population densities and reinforce the pest status of this aphid in commercial fir (Abies Miller; Pinaceae) plantations in Québec, Canada. During this study, we tested the effects of a warmer environment on colony growth rates of M. abietinus and aphid morph composition during the second generation of its cycle, which is key to colony size growth and potential damage to Christmas trees. We monitored M. abietinus populations on two host fir species and one host fir variety, in order to understand the early season dynamics of this aphid and its host tree. It was possible to distinguish the two overlapping generations of winged aphids leaving colonies, which led to observing a much higher proportion of wingless daughters, produced by the stem mother, than what had previously been reported. Colony growth rates were significantly higher in a warmer environment than in the nearby plantation, suggesting that warmer temperatures in late spring and early summer may provide the suitable conditions required for M. abietinus colonies of greater density.
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.
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.
The production of livestock feed in the USA is geographically concentrated, which poses several risks. Extreme weather events and disease outbreaks have the potential to disrupt production in these areas, which could reduce the national output of meat, dairy and eggs. Additionally, geographically concentrated livestock and feed production systems have been observed to contribute excessive nutrient loads to surrounding soil and water bodies, thereby threatening environmental sustainability. Geographic relocation of production systems has been proposed as an adaptation strategy to increase system resilience and this could take the shape of more geographically dispersed livestock feed production. We estimate the degree to which the demand for meat, dairy and eggs in the Northeast region is met with current levels of regional feed and livestock production, a term that we refer to as regional self-reliance. We combine mean annual (2001–2010) data on Northeast regional land use; crop output; meat, dairy and egg output; and food consumption with a livestock feed requirements model. An annual mean of over 6.1 million ha of land in the Northeast was dedicated to livestock feed from 2001 to 2010, with nearly 80% located in just three states (Pennsylvania, New York and West Virginia). The region is a net importer of livestock feed (in terms of total digestible nutrients and crude protein), as well as meat, dairy and eggs (in terms of total human-edible energy and protein). This is the result of a confluence of long-term regional trends that include the movement of agricultural production out of the region with a concomitant increase in the regional population and an increase in the national demand for meat, dairy and eggs. Limited slaughter output in the region is a key limiting factor to increasing the region's self-reliance for livestock products.
Toxoplasma gondii and Sarcocystis neurona are protozoan parasites with terrestrial definitive hosts, and both pathogens can cause fatal disease in a wide range of marine animals. Close monitoring of threatened southern sea otters (Enhydra lutris nereis) in California allowed for the diagnosis of dual transplacental transmission of T. gondii and S. neurona in a wild female otter that was chronically infected with both parasites. Congenital infection resulted in late-term abortion due to disseminated toxoplasmosis. Toxoplasma gondii and S. neurona DNA was amplified from placental tissue culture, as well as from fetal lung tissue. Molecular characterization of T. gondii revealed a Type X genotype in isolates derived from placenta and fetal brain, as well as in all tested fetal organs (brain, lung, spleen, liver and thymus). This report provides the first evidence for transplacental transmission of T. gondii in a chronically infected wild sea otter, and the first molecular and immunohistochemical confirmation of concurrent transplacental transmission of T. gondii and S. neurona in any species. Repeated fetal and/or neonatal losses in the sea otter dam also suggested that T. gondii has the potential to reduce fecundity in chronically infected marine mammals through parasite recrudescence and repeated fetal infection.
To examine sociodemographic variations among children <18 years in (1) rates of self-harm visits to emergency departments (EDs) and (2) physician follow-up after the self-harm visit in Alberta.
A retrospective, population-based cohort (2002–2011) of ED visits for self-harm by individuals <18 years was conducted using administrative databases from Alberta, Canada. Individuals were grouped by First Nations status or type of health care premium subsidy (family receipt of government subsidy, human services program subsidy, no subsidy received). Visits from 104 EDs were summarized by crude and directly standardized visit rates (DSVRs) per 100,000 individuals. Kaplan-Meier estimates for median estimated time to physician follow-up were calculated with 95% confidence intervals (CIs).
During the study period, visit rates decreased with the exception of children from families receiving government-sponsored program subsidy (DSVRs 163/100,000 to 250/100,000; p=0.032). First Nations children had disproportionately fewer follow-up visits compared to other children. The median time to follow-up for First Nations children was 39 days (95% CI: 32, 48) compared to 16 days for children from families receiving no subsidy (95% CI: 14, 19), who had the shortest follow-up time after an ED visit.
Sociodemographic differences were evident in ED visit rates as well as the number of and time to physician follow-up visit. The disparities experienced by First Nations children in the follow-up period highlight an opportunity for culturally-grounded risk and needs assessment in the ED to determine and facilitate timely and appropriate follow-up care.
Over 30% of Australasian amphibians are currently threatened with extinction. While habitat loss, introduced species and disease have been identified as major threats, the impacts of climate change are understudied. Threatened frogs fall into distinct biogeographical and ecological groupings that can be linked to specific threats (e.g. mountain- top endemics and climate change; stream-dwelling wet forest frogs and disease; and small island endemics and feral pests). The impacts of gradual climate change over millions of years has isolated specific species into climatic refugia (resulting in restricted geographic ranges), which combined with the ecological traits of these species (e.g. small clutch-size) dramatically increases extinction risk. Australasian frogs demonstrate intrinsic links between biogeographic history, species ecology and conservation status. The solutions to most threats are clear at a broad level, stop land clearing, reduce CO2 emissions and control feral animals; however, declines linked to the disease chytridiomycosis are not easily resolved. Chytridiomycosis is not a universal threat and understanding the causes of variation in impact is critically important. While the threats of land clearing, disease and introduced species are regional and/or species specific, the impacts of climate change must be examined carefully as all species are likely to affected. Here we cover these issues for Australasian frogs, presenting regional examples that highlight threats and avenues for future research and management.
Phylogenetic and biogeographic history
Over 30% of amphibian species are threatened with extinction globally making them the most threatened of the vertebrate groups (Wake and Vredenburg 2008). There are multiple threats to Austral frogs: e.g. disease – critically chytrid fungus for species with more aquatic lifestyles; small clutch size and limited range associated with higher decline or extinction risk; introduced species (Gambusia and trout in Australia, Gillespie and Hero, 1999; Murray et al., 2011; Rattus in New Zealand, Thurley and Bell, 1994; and mongoose in the Pacific Islands, Pernetta and Watling, 1979) and less specific threats, identified in both Austral and global analyses of amphibian declines: e.g. climate change (Hero et al., 2006, 2008; Hof et al., 2011) and habitat loss and fragmentation (Hero et al., 2008). These factors pose serious threats in many other regions of the world (Stuart, 2008) and their impacts vary among species and genera, depending on their current distribution and habitat use (Table 21.1).
We addressed the question of whether syllabic units of the presented language would activate words containing these syllables in the nonpresented language. In two lexical decision experiments using Spanish and German words presented to two groups of late Spanish–German and German–Spanish bilinguals and to two monolingual control groups, target words’ syllable-frequency in the nonpresented language was manipulated. Inhibitory effects of syllable-frequency in the nonpresented language were found only when Spanish–German bilinguals read German L2 words– suggesting that L2 sublexical syllabic units activated L1 syllabic neighbors’ representations that would interfere with L2 target processing. On the contrary, no inhibitory effects but rather a facilitation tendency due to syllable-frequency from the nonpresented German language was obtained for both groups of bilinguals reading Spanish words. This dissociation concerning the spread of activation from sublexical units to lexical representations from bilinguals’ two languages is discussed in terms of structural differences between the two languages.
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.
“The land took the name of the wells, the wells that had no bottom.”
In Part I of this paper we examined the external written sources and found no unambiguous evidence that an Almoravid conquest of ancient Ghana ever occurred. The local oral evidence reviewed in this part of our study supports our earlier hypothesis, in that we find nothing in the traditions to indicate any conquest of the eleventh-century sahelian state known to Arab geographers as “Ghana.” Instead, the oral traditions emphasize drought as having had much to do with the eventual disintegration of the Soninke state known locally as “Wagadu.”
An immediate problem involved in sifting the oral sources for evidence of an Almoravid conquest is that a positive identification between the Wagadu of oral tradition and the Ghana of written sources has never been established. Early observers like Tautain (1887) entertained no doubts in this regard, and recently Meillassoux seems to have accepted a connection, if not an identification, between Ghana and Wagadu when he notes that “les Wago, dont le nom a donné Wagadu, sont les plus clairement associés à l'histoire du Ghana.” However, much continues to be written on the subject, and the question remains a thorny one. On the lips of griots (traditional bards) and other local informants, Wagadu is a timeless concept, so a reliable temporal connection between people and events in the oral sources on one hand and Ghana at the time of the Almoravids on the other, is particularly elusive. Indeed, any link between the traditions discussed here and a specific date like 1076 must be regarded as very tenuous, as must any association of legendary events with Islamic dates. In western Sudanic tradition influenced by Islam, the hijra (A.D. 622) is both prestigious and convenient, a date with which virtually any event in the remote past can be associated, though such a claim may have nothing to do with any useful time scale.