Genomic dissection of the 1994 Cronobacter sakazakii outbreak in a French neonatal intensive care unit

Background: Cronobacter sakazakii is a member of the genus Cronobacter that has frequently been isolated from powdered infant formula (PIF) and linked with rare but fatal neonatal infections such as meningitis and necrotising enterocolitis. The Cronobacter MLST scheme has reported over 400 sequence types and 42 clonal complexes; however C. sakazakii clonal complex 4 (CC4) has been linked strongly with neonatal infections, especially meningitis. There have been a number of reported Cronobacter outbreaks over the last three decades. The largest outbreak of C. sakazakii was in a neonatal intensive care unit (NICU) in France (1994) that lasted over 3 months and claimed the lives of three neonates. The present study used whole genome sequencing data of 26 isolates obtained from this outbreak to reveal their relatedness. This study is first of its kind to use whole genome sequencing data to analyse a Cronobacter outbreak. Methods: Whole genome sequencing data was generated for 26 C. sakazakii isolates on the Illumina MiSeq platform. The whole genome phylogeny was determined using Mugsy and RaxML. SNP calls were determined using SMALT and SAMtools, and filtered using VCFtools. Results: The whole genome phylogeny suggested 3 distant clusters of C. sakazakii isolates were associated with the outbreak. SNP typing and phylogeny indicate the source of the C. sakazakii could have been from extrinsic contamination of reconstituted infant formula from the NICU environment and personnel. This pool of strains would have contributed to the prolonged duration of the outbreak, which was up to 3 months. Furthermore 3 neonates were co-infected with C. sakazakii from two different genotype clusters. Conclusion: The genomic investigation revealed the outbreak consisted of an heterogeneous population of C. sakazakii isolates. The source of the outbreak was not identified, but probably was due to environmental and personnel reservoirs resulting in extrinsic contamination of the neonatal feeds. It also indicated that C. sakazakii isolates from different genotype clusters have the ability to co-infect neonates

Heat capacity and phonon mean free path of wurtzite GaN

We report on lattice specific heat of bulk hexagonal GaN measured by the heat flow method in the temperature range 20-300 K and by the adiabatic method in the range 5-70 K. We fit the experimental data using two temperatures model. The best fit with the accuracy of 3 % was obtained for the temperature independent Debye's temperature $\theta_{\rm D}=365$ {\rm K} and Einstein's temperature $\theta_{\rm E}=880$ {\rm K}. We relate these temperatures to the function of density of states. Using our results for heat conduction coefficient, we established in temperature range 10-100 K the explicit dependence of the phonon mean free path on temperature $\it{l}_{\rm ph}\propto T^{-2}$. Above 100 K, there is the evidence of contribution of the Umklapp processes which limit phonon free path at high temepratures. For phonons with energy $k_{\rm B}\times 300$ {\rm K} the mean free path is of the order 100 {\rm nm}Comment: 5 pages, 4 figure

Influence of the columnar structure of heteroepitaxial nitride layers on the transport of electrons

The influence of the columnar structure of heteroepitaxial nitride layers on electronic transport has been described within the model of thermionic emission of carriers through potential barriers formed at grain boundaries. Dependence of the potential barrier height on the material properties and applied external voltage has been calculated. Potential barriers heights for gallium nitride layers grown by the metalorganic vapour phase epitaxy method has been estimated to be in the range of 20-60 meV and 10-40 meV in the dark and under illumination, respectively

New fabrication approach to ZnO multiple nanofiber sensors

In the presented work, ZnO nanofiber sensor structures designed and fabricated using a standard microelectronic device technology were studied. The structures in the configuration of a resistor with chemically active ZnO multiple nanofibers deposited by electrospinning method were prepared. Investigation of inclusion in the process reactive- ly sputtered AlN insulating film to improve the robustness of the nanofibres on the substrate was undertaken. Selective wet chemical etching of AlN film using photoresist developers and a photoresist mask to define the sensor active area was studied. The Ti/Au ohmic contacts were fabricated using the lift-off photolithography process. To- pography of the sensor structure details was investigated using AFM. Electrical charac- terization by means of I-V measurements was made. Sensitivity to the physiologically relevant concentration of Bovine Serum Albumin in water solution was shown. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2058

What’s missing from legal geography and materialist studies of law? Absence and the assembling of asylum appeal hearings in Europe

This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: Due to the ethical and legally sensitive nature of the research, ethnographic notes taken in court could not be made openly available. Appellant interviewees were not asked for their permission to share their interview transcripts in an online open archive because of concerns that they could misunderstand what was being asked for, or feel obliged to agree but subsequently feel less able to conduct free conversation in research interviews as a result, thereby negatively impacting on the quality of the data generated. Additional details relating to, and data resulting from, to a survey taken during observations of British asylum appeals between 2013 and 2016 are available from the UK Data Archive (persistent identifier: 10.5255/UKDA-SN-852032).There is an absence of absence in legal geography and materialist studies of the law. Drawing on a multi‐sited ethnography of European asylum appeal hearings, this paper illustrates the importance of absences for a fully‐fledged materiality of legal events. We show how absent materials impact hearings, that non‐attending participants profoundly influence them, and that even when participants are physically present, they are often simultaneously absent in other, psychological registers. In so doing we demonstrate the importance and productivity of thinking not only about law's omnipresence but also the absences that shape the way law is experienced and practiced. We show that attending to the distribution of absence and presence at legal hearings is a way to critically engage with legal performance.Economic and Social Research Council (ESRC)European Research Council (ERC

Comments on the continuing widespread and unnecessary use of a defective emission equation in field emission related literature

Field electron emission (FE) has relevance in many different technological contexts. However, many related technological papers use a physically defective elementary FE equation for local emission current density (LECD). This equation takes the tunneling barrier as exactly triangular, as in the original FE theory of 90 years ago. More than 60 years ago, it was shown that the so-called Schottky-Nordheim (SN) barrier, which includes an image-potential-energy term (that models exchange-and-correlation effects) is better physics. For a metal-like emitter with work-function 4.5 eV, the SN-barrier-related Murphy-Good FE equation predicts LECD values that are higher than the elementary equation values by a large factor, often between around 250 and around 500. By failing to mention/apply this 60-year-old established science, or to inform readers of the large errors associated with the elementary equation, many papers (aided by defective reviewing) spread a new kind of "pathological science", and create a modern research-integrity problem. The present paper aims to enhance author and reviewer awareness by summarizing relevant aspects of FE theory, by explicitly identifying the misjudgment in the original 1928 Fowler-Nordheim paper, by explicitly calculating the size of the resulting error, and by showing in detail why most FE theoreticians regard the 1950s modifications as better physics. Suggestions are made, about nomenclature and about citation practice, that may help to diminish misunderstandings.Comment: Submitted for publication; in v2 a correction to historical information (with no numerical consequences) has been made in Appendix

The archaeology of the military orders: the material culture of holy war

This paper reviews the current state of research into the archaeology of the military orders. It contrasts the advances made by historians and archaeologists, with the latter continuing to focus on the particularism of individual sites, with an emphasis on architectural analyses. Historians have contributed new insights by adopting a supranational approach. This paper argues that archaeologists can build on this by adopting a more problem-oriented, comparative approach. Drawing on examples from frontier and heartland territories, archaeological approaches are subdivided into material investment, material identity and cultural landscapes, to place sites of the military orders within a long-term, multi-scalar contexts. This contributes to a broader social and economic understanding of the orders, who contributed significantly to urbanisation, rural development and trade, and invested in material expressions of their authority and ideology. The paper concludes that more holistic, inter-regional approaches will move the archaeological study of the military orders forward

Molecular mechanisms of toxicity of silver nanoparticles in zebrafish embryos.

addresses: Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK. [email protected]: Journal Article; Research Support, Non-U.S. Gov'tThis is an open access article that is freely available in ORE or from the publisher's web site. http://pubs.acs.org/doi/abs/10.1021/es401758d. Please cite the published version© 2013 American Chemical SocietySupporting Information: Further details on the methodology and results for the characterization of the silver particles used for the exposures, mortality curves, sequencing analysis, and a number of supporting figures and tables. This material is available free of charge via the Internet at http://pubs.acs.org.Silver nanoparticles cause toxicity in exposed organisms and are an environmental health concern. The mechanisms of silver nanoparticle toxicity, however, remain unclear. We examined the effects of exposure to silver in nano-, bulk-, and ionic forms on zebrafish embryos (Danio rerio) using a Next Generation Sequencing approach in an Illumina platform (High-Throughput SuperSAGE). Significant alterations in gene expression were found for all treatments and many of the gene pathways affected, most notably those associated with oxidative phosphorylation and protein synthesis, overlapped strongly between the three treatments indicating similar mechanisms of toxicity for the three forms of silver studied. Changes in oxidative phosphorylation indicated a down-regulation of this pathway at 24 h of exposure, but with a recovery at 48 h. This finding was consistent with a dose-dependent decrease in oxygen consumption at 24 h, but not at 48 h, following exposure to silver ions. Overall, our data provide support for the hypothesis that the toxicity caused by silver nanoparticles is principally associated with bioavailable silver ions in exposed zebrafish embryos. These findings are important in the evaluation of the risk that silver particles may pose to exposed vertebrate organisms.Natural Environment Research Council (NERC)NERC Biomolecular Analysis FacilityUK Environment AgencySystems Biology Seed fund, University of Exete