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Editorial on plants as alternative hosts for human and animal pathogens
Many of the most prevalent and devastating human and animal pathogens have part of their lifecycle out-with the animal host. These pathogens have a remarkably wide capacity to adapt to a range of quite different environments: physical, chemical and biological, which is part of the key to their success. Many of the well-known pathogens that are able to jump between hosts in different biological kingdoms are transmitted through the faecal-oral and direct transmission pathways, and as such have become important food-borne pathogens. Some high-profile examples include fresh produce-associated outbreaks of Escherichia coli O157:H7 and Salmonella enterica. Other pathogens may be transmitted via direct contact or aerosols are include important zoonotic pathogens. It is possible to make a broad division between those pathogens that are passively transmitted via vectors and need the animal host for replication (e.g. virus and parasites), and those that are able to actively interact with alternative hosts, where they can proliferate (e.g. the enteric bacteria). This research topic will focus on plants as alternative hosts for human pathogens, and the role of plants in their transmission back to humans. The area is particularly exciting because it opens up new aspects to the biology of some microbes already considered to be very well characterised. One aspect of cross-kingdom host colonisation is in the comparison between the hosts and how the microbes are able to use both common and specific adaptations for each situation. The area is still in relative infancy and there are far more questions than answers at present. We aim to address important questions underlying the interactions for both the microbe and plant host in this research topic
An experimental and computational study of tip clearance effects on a transonic turbine stage
This paper describes an experimental and computational investigation into the influence of tip clearance on the blade tip heat load of a high-pressure (HP) turbine stage. Experiments were performed in the Oxford Rotor facility which is a 1Âœ stage, shroudless, transonic, high pressure turbine. The experiments were conducted at an engine representative Mach number and Reynolds number. Rotating frame instrumentation was used to capture both aerodynamic and heat flux data within the rotor blade row. Two rotor blade tip clearances were tested (1.5% and 1.0% of blade span). The experiments were compared with computational fluid dynamics (CFD) predictions made using a steady Reynolds-averaged NavierâStokes (RANS) solver. The experiments and computational predictions were in good agreement. The blade tip heat transfer was observed to increase with reduced tip gap in both the CFD and the experiment. The augmentation of tip heat load at smaller clearances was found to be due to the ingestion of high relative total temperature fluid near the casing, generated through casing shear.This work was sponsored by Rolls-Royce plc and the Isle of Man Government.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.ijheatfluidflow.2015.09.00
Healthcare Stereotype Threat in Older Adults in the Health and Retirement Study
Introduction
Healthcare stereotype threat is the threat of being personally reduced to group stereotypes that commonly operate within the healthcare domain, including stereotypes regarding unhealthy lifestyles and inferior intelligence. The objective of this study was to assess the extent to which people fear being judged in healthcare contexts on several characteristics, including race/ethnicity and age, and to test predictions that experience of such threats would be connected with poorer health and negative perceptions of health care.
Methods
Data were collected as part of the 2012 Health and Retirement Study (HRS). A module on healthcare stereotype threat, designed by the research team, was administered to a random subset (n=2,048 of the total 20,555) of HRS participants. The final sample for the present healthcare stereotype threat experiment consists of 1,479 individuals. Logistic regression was used to test whether healthcare stereotype threat was associated with self-rated health, reported hypertension, and depressive symptoms, as well as with healthcare-related outcomes, including physician distrust, dissatisfaction with health care, and preventative care use.
Results
Seventeen percent of respondents reported healthcare stereotype threat with respect to one or more aspects of their identities. As predicted, healthcare stereotype threat was associated with higher physician distrust and dissatisfaction with health care, poorer mental and physical health (i.e., self-rated health, hypertension, and depressive symptoms), and lower odds of receiving the influenza vaccine.
Conclusions
The first of its kind, this study demonstrates that people can experience healthcare stereotype threat on the basis of various stigmatized aspects of social identity, and that these experiences can be linked with larger health and healthcare-related outcomes, thereby contributing to disparities among minority groups
Blackjack Players Demonstrate the Near Miss Effect
The effect of the ânear-missâ as a potential conditioned reinforcer in slot machine play has recently been the subject of behavioral research on gambling. The present study extends prior research by examining this effect during the game of blackjack. Participants consisted of college undergraduates with no history of problematic gambling. Their verbal ratings of closeness to winning were recorded and examined for each of 50 hands of standard blackjack per session. Results indicated that as the number difference between the dealer and playerâs hands decreased, closeness to win rating increased. Also for each participant, non-bust losses were rated closer to winning than losses where the player busted
Sequential Electrostatic Assembly of a Polymer Surfactant Corona Increases Activity of the Phosphotriesterase arPTE
We present a new methodology for the generation of discrete molecularly dispersed enzymeâpolymerâsurfactant bioconjugates. Significantly, we demonstrate that >3-fold increase in the catalytic efficiency of the diffusion-limited phosphotriesterase arPTE can be achieved through sequential electrostatic addition of cationic and anionic polymer surfactants, respectively. Here, the polymer surfactants assemble on the surface of the enzyme via ion exchange to yield a compact corona. The observed rate enhancement is consistent with a mechanism whereby the polymerâsurfactant corona gives rise to a decrease in the dielectric constant in the vicinity of the active site of the enzyme, accelerating the rate-determining product diffusion step. The facile methodology has significant potential for increasing the efficiency of enzymes and could therefore have a substantially positive impact for industrial enzymology
The EVIL-MC Model for Ellipsoidal Variations of Planet-Hosting Stars and Applications to the HAT-P-7 System
We present a new model for Ellipsoidal Variations Induced by a Low-Mass
Companion, the EVIL-MC model. We employ several approximations appropriate for
planetary systems to substantially increase the computational efficiency of our
model relative to more general ellipsoidal variation models and improve upon
the accuracy of simpler models. This new approach gives us a unique ability to
rapidly and accurately determine planetary system parameters. We use the
EVIL-MC model to analyze Kepler Quarter 0-2 (Q0-2) observations of the HAT-P-7
system, an F-type star orbited by a nearly Jupiter-mass companion. Our analysis
corroborates previous estimates of the planet-star mass ratio q = (1.10 +/-
0.06) x 10^(-3), and we have revised the planet's dayside brightness
temperature to 2680 +10/-20 K. We also find a large difference between the day-
and nightside planetary flux, with little nightside emission. Preliminary
dynamical+radiative modeling of the atmosphere indicates this result is
qualitatively consistent with high altitude absorption of stellar heating.
Similar analyses of Kepler and CoRoT photometry of other planets using EVIL-MC
will play a key role in providing constraints on the properties of many
extrasolar systems, especially given the limited resources for follow-up and
characterization of these systems. However, as we highlight, there are
important degeneracies between the contributions from ellipsoidal variations
and planetary emission and reflection. Consequently, for many of the hottest
and brightest Kepler and CoRoT planets, accurate estimates of the planetary
emission and reflection, diagnostic of atmospheric heat budgets, will require
accurate modeling of the photometric contribution from the stellar ellipsoidal
variation.Comment: Accepted to ApJ; minor revisions to original submission; An IDL
version of the EVIL-MC model is publicly available at
http://www.lpl.arizona.edu/~bjackson/idl_code/index.htm
Citation Networks in High Energy Physics
The citation network constituted by the SPIRES data base is investigated
empirically. The probability that a given paper in the SPIRES data base has
citations is well described by simple power laws, ,
with for less than 50 citations and for 50 or more citations. Two models are presented that both represent the
data well, one which generates power laws and one which generates a stretched
exponential. It is not possible to discriminate between these models on the
present empirical basis. A consideration of citation distribution by subfield
shows that the citation patterns of high energy physics form a remarkably
homogeneous network. Further, we utilize the knowledge of the citation
distributions to demonstrate the extreme improbability that the citation
records of selected individuals and institutions have been obtained by a random
draw on the resulting distribution.Comment: 9 pages, 6 figures, 2 table
The diastereoselective Meth-Cohn epoxidation of camphor-derived vinyl sulfones
Some camphor-derived vinyl sulfones bearing oxygen functionality at the allylic position have been synthesized and their nucleophilic epoxidation reactions under Meth-Cohn conditions have been explored. The Îł-oxygenated camphor-derived vinyl sulfones underwent mildly diastereoselective nucleophilic epoxidation reactions, affording the derived sulfonyloxiranes in up to 5.8:1 dr. The observed diastereoselectivities were sensitive to the reaction conditions employed. In contrast, no stereoselectivity was observed in the nucleophilic epoxidation of the corresponding Îł-oxygenated isobornyl vinyl sulfone. A tentative mechanism has been proposed to explain the origins of the diastereoselectivit
Developing a translational ecology workforce
We define a translational ecologist as a professional ecologist with diverse disciplinary expertise and skill sets, as well as a suitable personal disposition, who engages across social, professional, and disciplinary boundaries to partner with decision makers to achieve practical environmental solutions. Becoming a translational ecologist requires specific attention to obtaining critical non-scientific disciplinary breadth and skills that are not typically gained through graduate-level education. Here, we outline a need for individuals with broad training in interdisciplinary skills, use our personal experiences as a basis for assessing the types of interdisciplinary skills that would benefit potential translational ecologists, and present steps that interested ecologists may take toward becoming translational. Skills relevant to translational ecologists may be garnered through personal experiences, informal training, short courses, fellowships, and graduate programs, among others. We argue that a translational ecology workforce is needed to bridge the gap between science and natural resource decisions. Furthermore, we argue that this task is a cooperative responsibility of individuals interested in pursuing these careers, educational institutions interested in training scientists for professional roles outside of academia, and employers seeking to hire skilled workers who can foster stakeholder-engaged decision making
Genetic dissection of the tissueâspecific roles of type III effectors and phytotoxins in the pathogenicity of Pseudomonas syringae pv. syringae to cherry
When compared with other phylogroups (PGs) of the Pseudomonas syringae species complex, P. syringae pv. syringae (Pss) strains within PG2 have a reduced repertoire of type III effectors (T3Es) but produce several phytotoxins. Effectors within the cherry pathogen Pss 9644 were grouped based on their frequency in strains from Prunus as the conserved effector locus (CEL) common to most P. syringae pathogens; a core of effectors common to PG2; a set of PRUNUS effectors common to cherry pathogens; and a FLEXIBLE set of T3Es. Pss 9644 also contains gene clusters for biosynthesis of toxins syringomycin, syringopeptin and syringolin A. After confirmation of virulence gene expression, mutants with a sequential series of T3E and toxin deletions were pathogenicity tested on wood, leaves and fruits of sweet cherry (Prunus avium) and leaves of ornamental cherry (Prunus incisa). The toxins had a key role in disease development in fruits but were less important in leaves and wood. An effectorless mutant retained some pathogenicity to fruit but not wood or leaves. Striking redundancy was observed amongst effector groups. The CEL effectors have important roles during the early stages of leaf infection and possibly acted synergistically with toxins in all tissues. Deletion of separate groups of T3Es had more effect in P. incisa than in P. avium. Mixed inocula were used to complement the toxin mutations in trans and indicated that strain mixtures may be important in the field. Our results highlight the nicheâspecific role of toxins in P. avium tissues and the complexity of effector redundancy in the pathogen Pss 9644
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