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The horticultural industry is an important source of invasive ornamental plant species, which is part of the motivation for an increased emphasis on using native alternatives. We were interested in the possibility that plants marketed in the midwestern United States as the native Celastrus scandens, or American bittersweet, were actually the difficult-to-distinguish invasive Celastrus orbiculatus (oriental bittersweet) or hybrids of the two species. We used nuclear microsatellite DNA loci to compare the genetic identities of 34 plants from 11 vendors with reference plants from wild populations of known species identity. We found that 18 samples (53%) were mislabeled, and 7 of the 11 vendors sold mislabeled plants. Mislabeled plants were more likely to be purchased through Internet or phone order shipments and were significantly less expensive than accurately labeled plants. Vendors marketed mislabeled plants under five different cultivar names, as well as unnamed strains. Additionally, the most common native cultivar, ‘Autumn Revolution,’ displays reproductive characteristics that diverge from the typical C. scandens, which could be of some concern. The lower price and abundance of mislabeled invasive plants introduces incentives for consumers to unknowingly contribute to the spread of C. orbiculatus. Revealing the potential sources of C. orbiculatus is critical for controlling further spread of the invasive vine and limiting its impact on C. scandens populations.
An unprecedented outbreak of Ebola virus diseases (EVD) occurred in West Africa from March 2014 to January 2016. The French Institute for Public Health implemented strengthened surveillance to early identify any imported case and avoid secondary cases.
Febrile travellers returning from an affected country had to report to the national emergency healthcare hotline. Patients reporting at-risk exposures and fever during the 21st following day from the last at-risk exposure were defined as possible cases, hospitalised in isolation and tested by real-time polymerase chain reaction. Asymptomatic travellers reporting at-risk exposures were considered as contact and included in a follow-up protocol until the 21st day after the last at-risk exposure.
From March 2014 to January 2016, 1087 patients were notified: 1053 were immediately excluded because they did not match the notification criteria or did not have at-risk exposures; 34 possible cases were tested and excluded following a reliable negative result. Two confirmed cases diagnosed in West Africa were evacuated to France under stringent isolation conditions. Patients returning from Guinea (n = 531; 49%) and Mali (n = 113; 10%) accounted for the highest number of notifications.
No imported case of EVD was detected in France. We are confident that our surveillance system was able to classify patients properly during the outbreak period.
The traces of macroboring organisms are known throughout the Phanerozoic, with diversification and exploitation of the macroboring niche paralleling variations in the development of skeletal metazoa. The oldest macroboring biota is an abundant yet low diversity fauna in hardgrounds and reefs of Lower Cambrian age. Following the extinction of archaeocyathids at the end of the Lower Cambrian (and thus the demise of skeletal reefs until the Middle Ordovician), boring organisms appear to be restricted to submarine hardgrounds. With the development of skeletal reefs in the Middle Ordovician the macroboring fauna shows a rapid speciation and a dramatic increase in diversity. This same pattern occurs again in the Devonian. This record appears to represent refuge of the fauna in low stress, hardground environments when skeletal reefs were not present and radiation in the high stress environment of the reef when large skeletal metazoa were abundant and diverse.
The ex situ lift out (EXLO) adhesion forces are reviewed and new applications of EXLO for focused ion beam (FIB)-prepared specimens are described. EXLO is used to manipulate electron transparent specimens on microelectromechanical systems carrier devices designed for in situ electron microscope analysis. A new patented grid design without a support film is described for EXLO. This new slotted grid design provides a surface for holding the specimen in place and also allows for post lift out processing. Specimens may be easily manipulated into a backside orientation to reduce FIB curtaining artifacts with this slotted grid. Large EXLO specimens can be manipulated from Xe+ plasma FIB prepared specimens. Finally, applications of EXLO and manipulation of FIB specimens using a vacuum probe lift out method are shown. The vacuum probe provides more control for placing specimens on the new slotted grids and also allows for easy manipulation into a backside configuration.
Infants in the neonatal intensive care unit (NICU) are at increased risk for methicillin-resistant Staphylococcus aureus (MRSA) acquisition. Outbreaks may be difficult to identify due in part to limitations in current molecular genotyping available in clinical practice. Comparison of genome-wide single nucleotide polymorphisms (SNPs) may identify epidemiologically distinct isolates among a population sample that appears homogenous when evaluated using conventional typing methods.
To investigate a putative MRSA outbreak in a NICU utilizing whole-genome sequencing and phylogenetic analysis to identify recent transmission events.
Clinical and surveillance specimens collected during clinical care and outbreak investigation.
A total of 17 neonates hospitalized in a 43-bed level III NICU in northeastern Florida from December 2010 to October 2011 were included in this study.
We assessed epidemiological data in conjunction with 4 typing methods: antibiograms, PFGE, spa types, and phylogenetic analysis of genome-wide SNPs.
Among the 17 type USA300 isolates, 4 different spa types were identified using pulsed-field gel electrophoresis. Phylogenetic analysis identified 5 infants as belonging to 2 clusters of epidemiologically linked cases and excluded 10 unlinked cases from putative transmission events. The availability of these results during the initial investigation would have improved infection control interventions.
Whole-genome sequencing and phylogenetic analysis are invaluable tools for epidemic investigation; they identify transmission events and exclude cases mistakenly implicated by traditional typing methods. When routinely applied to surveillance and investigation in the clinical setting, this approach may provide actionable intelligence for measured, appropriate, and effective interventions.
Infect. Control Hosp. Epidemiol. 2015;36(7):777–785
Transmission electron microscopy (TEM) based orientation mapping has been used to measure the length fraction of coherent and incoherent Σ3 grain boundaries in a series of six nanocrystalline Cu thin films with thicknesses in the range of 26–111 nm and grain sizes from 51 to 315 nm. The films were annealed at the same temperature (600 °C) for the same length of time (30 min), have random texture, and vary only in grain size and film thickness. A strong grain size dependence of Σ3 (coherent and incoherent) and coherent Σ3 boundary fraction was observed. The experimental results are quantitatively compared with three physical models for the formation of annealing twins developed for microscale materials. The experimental results for the nanoscale Cu films are found to be in good agreement with the two microscale models that explain twin formation as a growth accident process.
We compare forests dominated by Gilbertiodendron dewevrei at the Dja Biosphere Reserve (Cameroon) with adjacent high-diversity mixed forests in terms of tree-species composition and stand structure, in order to understand the co-occurrence of mixed forest tree species in the monodominant forest. A total of 18 1-ha permanent plots were established in the two forest types. In each plot, all trees with dbh ≥10 cm were identified as were those <10 cm dbh within a subsample of 300 m2. Species richness was significantly different between the two forest types. Mixed forest had an average of 109 species ha−1 for trees ≥10 cm dbh and 137 species for trees <10 cm dbh. By contrast, G. dewevrei-dominated forest had an average of 47 species ha−1 (≥10 cm dbh) and 92 species (<10 cm dbh). There was no significant difference in terms of stem density of the trees with dbh <10 cm between the two forests (mixed: 3.7 stems m−2; monodominant: 3.1 stems m−2). As G. dewevrei is a shade-tolerant species that can regenerate under its own shade, its higher stem density and basal area can reduce species richness of an area.
Although playing a key role in the understanding of the supernova phenomenon, the evolution of massive stars still suffers from uncertainties in their structure, even during their “quiet” main sequence phase and later on during their subgiant and helium burning phases. What is the extent of the mixed central region? In the local mixing length theory (LMLT) frame, are there structural differences using Schwarzschild or Ledoux convection criterion? Where are located the convective zone boundaries? Are there intermediate convection zones during MS and post-MS phase, and what is their extent and location? We discuss these points and show how asteroseismology could bring some light on these questions.
Owing to the development of new ion source technology, users of focused ion beams (FIBs) have access to superior performance when compared with the industry standard Ga+ liquid metal ion source. FIBs equipped with an inductively coupled plasma (ICP) ion source are better able to carry out large volume milling applications by providing up to 2 µA of Xe+ ions focused into a sub-5 µm spot. However, ICP FIBs are presently limited to 25 nm imaging resolution at 1 pA.The gas field ionization source (GFIS) relies upon an ion source that is the size of a single atom and correspondingly gains high brightness through its very small source size. The high brightness allows the GFIS to produce a very small focused probe size (<0.35 nm for helium), but with comparatively small beam currents (less than 2 pA). The Cs+ low temperature ion source, still being developed, has a projected sub-nm focal spot size at 1 pA, a maximum current of several nanoamps, and has the potential to offer integrated secondary ion mass spectrometry capabilities.
A mixed finite element method for the Navier–Stokes equations is introduced in which the
stress is a primary variable. The variational formulation retains the mathematical
structure of the Navier–Stokes equations and the classical theory extends naturally to
this setting. Finite element spaces satisfying the associated inf–sup conditions are
There is increasing emphasis on the need for effective ways of sharing knowledge to enhance environmental management and sustainability. Knowledge exchange (KE) are processes that generate, share and/or use knowledge through various methods appropriate to the context, purpose, and participants involved. KE includes concepts such as sharing, generation, coproduction, comanagement, and brokerage of knowledge. This paper elicits the expert knowledge of academics involved in research and practice of KE from different disciplines and backgrounds to review research themes, identify gaps and questions, and develop a research agenda for furthering understanding about KE. Results include 80 research questions prefaced by a review of research themes. Key conclusions are: (1) there is a diverse range of questions relating to KE that require attention; (2) there is a particular need for research on understanding the process of KE and how KE can be evaluated; and (3) given the strong interdependency of research questions, an integrated approach to understanding KE is required. To improve understanding of KE, action research methodologies and embedding evaluation as a normal part of KE research and practice need to be encouraged. This will foster more adaptive approaches to learning about KE and enhance effectiveness of environmental management.
Canada's Nuclear Waste Management Organization has recommended to the Canadian federal government an adaptive phased management approach to the long-term management of used nuclear fuel. This approach includes isolation in a deep geologic repository. In such a repository, the fuel would be sealed inside a carbon steel-lined copper container. To assist the development of performance assessment models studies of fuel behaviour inside a failed waste container are underway. Using an iterative modeling and experimental approach, the important features and processes that determine fuel behaviour have been identified and studied. These features and processes are discussed and the results of studies to elucidate specific mechanisms and determine important parameter values summarized.
Nanotopography refers to 10-100 nm surface height variations that exist on a lateral millimeter length scale on unpatterned silicon wafers. Chemical mechanical polishing (CMP) of deposited or grown films (e.g., oxide or nitride) on such wafers can generate undesirable film thinning which can be of substantial concern in shallow trench isolation (STI) manufacturability. Proper simulation of the effect of nanotopography on post-CMP film thickness is needed to help in the measurement, analysis, diagnosis, and correction of potential problems.
Our previous work has focused on modeling approaches that seek to capture the thinning and post-CMP film thickness variation that results from nanotopography, using different modeling approaches. The importance of relative length scale of the CMP process used (planarization length) to the length scale of the nanotopography on the wafer (nanotopography length) has been suggested.
In this work, we report on extensive experiments using sets of 200 mm epi wafers with a variety of nanotopography signatures (i.e., different nanotopography lengths), and CMP processes of various planarization lengths. Experimental results indicate a clear relationship between the relative scales of planarization length and nanotopography length: when the planarization length is less than the nanotopography length, little thinning occurs; when the CMP process has a larger planarization length, surface height variations are transferred into thin film thickness variations. In addition to presenting these experimental results, modeling of the nanotopography effect on dielectric CMP processes is reviewed, and measurement data from the experiments are compared to model predictions. Results show a good correlation between the model prediction and the experimental data.
We examined an as-processed yttria-stabilized zirconia (YSZ) on platinum aluminide bond coat (BC), produced by electron beam physical vapor deposition, with transmission electron microscopy, including energy dispersive X-ray spectroscopy and hollow-cone diffraction. Columnar α-Al2O3 grains (∼100nm) formed at the interface between the BC and YSZ. A thin intermix (∼50nm) region was observed between the α-Al2O3 and YSZ. Hollow cone diffraction showed that the α-Al2O3 grains and the small-grained (∼10nm) YSZ near the α-Al2O3 are randomly oriented, without preferential texturing. No evidence of spinel formation was noted.