Epeoloides pilosulus (Cresson) Rediscovered in Michigan, with Notes on the Distribution and Status of its Macropis hosts.

Epeoloides pilosulus (Cresson 1878) is one of the rarest bees in North America with only a handful of records since 1960. The last collection in Michigan was made in 1944. Epeoloides pilosulus is a brood parasite of Macropis bees, which until recently had not been collected in Michigan for several decades. Bee surveys in Midland County, Michigan have led to the rediscovery of E. pilosulus in this state – the first record in 74 years. Michigan becomes the fourth state where E. pilosulus has been rediscovered after Connecticut in 2006, New York in 2014 and Maine in 2016, and the sixth region in North America after Nova Scotia in 2002 and Alberta in 2010. State-wide bee surveys have also shown that the principal host, Macropis nuda (Provancher 1882), remains widespread in Michigan, and that Macropis patellata Patton 1880 is newly recorded for the state

Indole is an inter-species biofilm signal mediated by SdiA

<p>Abstract</p> <p>Background</p> <p>As a stationary phase signal, indole is secreted in large quantities into rich medium by <it>Escherichia coli </it>and has been shown to control several genes (e.g., <it>astD</it>, <it>tnaB</it>, <it>gabT</it>), multi-drug exporters, and the pathogenicity island of <it>E. coli</it>; however, its impact on biofilm formation has not been well-studied.</p> <p>Results</p> <p>Through a series of global transcriptome analyses, confocal microscopy, isogenic mutants, and dual-species biofilms, we show here that indole is a non-toxic signal that controls <it>E. coli </it>biofilms by repressing motility, inducing the sensor of the quorum sensing signal autoinducer-1 (SdiA), and influencing acid resistance (e.g., <it>hdeABD, gadABCEX</it>). Isogenic mutants showed these associated proteins are directly related to biofilm formation (e.g., the <it>sdiA </it>mutation increased biofilm formation 50-fold), and SdiA-mediated transcription was shown to be influenced by indole. The reduction in motility due to indole addition results in the biofilm architecture changing from scattered towers to flat colonies. Additionally, there are 12-fold more <it>E. coli </it>cells in dual-species biofilms grown in the presence of <it>Pseudomonas </it>cells engineered to express toluene <it>o-</it>monooxygenase (TOM, which converts indole to an insoluble indigoid) than in biofilms with pseudomonads that do not express TOM due to a 22-fold reduction in extracellular indole. Also, indole stimulates biofilm formation in pseudomonads. Further evidence that the indole effects are mediated by SdiA and homoserine lactone quorum sensing is that the addition of <it>N</it>-butyryl-, <it>N</it>-hexanoyl-, and <it>N</it>-octanoyl-<it>L</it>-homoserine lactones repress <it>E. coli </it>biofilm formation in the wild-type strain but not with the <it>sdiA </it>mutant.</p> <p>Conclusion</p> <p>Indole is an interspecies signal that decreases <it>E. coli </it>biofilms through SdiA and increases those of pseudomonads. Indole may be manipulated to control biofilm formation by oxygenases of bacteria that do not synthesize it in a dual-species biofilm. Furthermore, <it>E. coli </it>changes its biofilm in response to signals it cannot synthesize (homoserine lactones), and pseudomonads respond to signals they do not synthesize (indole).</p

A metagenomic assessment of the bacteria associated with Lucilia sericata and Lucilia cuprina (Diptera: Calliphoridae)

Lucilia Robineau-Desvoidy (Diptera: Calliphoridae) is a blow fly genus of forensic, medical, veterinary, and agricultural importance. This genus is also famous because of its beneficial uses in maggot debridement therapy (MDT). Although the genus is of considerable economic importance, our knowledge about microbes associated with these flies and how these bacteria are horizontally and trans-generationally transmitted is limited. In this study, we characterized bacteria associated with different life stages of Lucilia sericata (Meigen) and Lucilia cuprina(Wiedemann) and in the salivary gland of L. sericata by using 16S rDNA 454 pyrosequencing. Bacteria associated with the salivary gland of L. sericata were also characterized using light and transmission electron microscopy (TEM). Results from this study suggest that the majority of bacteria associated with these flies belong to phyla Proteobacteria, Firmicutes, andBacteroidetes, and most bacteria are maintained intragenerationally, with a considerable degree of turnover from generation to generation. In both species, second-generation eggs exhibited the highest bacterial phylum diversity (20 % genetic distance) than other life stages. The Lucilia sister species shared the majority of their classified genera. Of the shared bacterial genera, Providencia, Ignatzschineria, Lactobacillus, Lactococcus, Vagococcus, Morganella, and Myroides were present at relatively high abundances. Lactobacillus, Proteus,Diaphorobacter, and Morganella were the dominant bacterial genera associated with a survey of the salivary gland of L. sericata. TEM analysis showed a sparse distribution of both Gram-positive and Gram-negative bacteria in the salivary gland of L. sericata. There was more evidence for horizontal transmission of bacteria than there was for trans-generational inheritance. Several pathogenic genera were either amplified or reduced by the larval feeding on decomposing liver as a resource. Overall, this study provides information on bacterial communities associated with different life stages of Lucilia and their horizontal and trans-generational transmission, which may help in the development of better vector-borne disease management and MDT methods

Toxin-Antitoxin Systems Influence Biofilm and Persister Cell Formation and the General Stress Response

In many genomes, toxin-antitoxin (TA) systems have been identified; however, their role in cell physiology has been unclear. Here we examine the evidence that TA systems are involved in biofilm formation and persister cell formation and that these systems may be important regulators of the switch from the planktonic to the biofilm lifestyle as a stress response by their control of secondary messenger 3,5-cyclic diguanylic acid. Specifically, upon stress, the sequence-specific mRNA interferases MqsR and MazF mediate cell survival. In addition, we propose that TA systems are not redundant, as they may have developed to respond to specific stresses. Toxin-antitoxin (TA) systems typically consist of two genes in an operon which encode a stable toxin that disrupts an essential cellular process (e.g., translation via mRNA degrada-tion) and a labile antitoxin (either RNA or a protein) that prevents toxicity (73). RNA antitoxins are known as type I if they inhibit toxin translation as antisense RNA or type III if they inhibit toxin activity; type II antitoxins are proteins that inhibit toxin activity (48). For type II systems (Fig. 1), th

Conformational Entropy as a Means to Control the Behavior of Poly(diketoenamine) Vitrimers In and Out of Equilibrium.

Control of equilibrium and non-equilibrium thermomechanical behavior of poly(diketoenamine) vitrimers is shown by incorporating linear polymer segments varying in molecular weight (MW) and conformational degrees of freedom into the dynamic covalent network. While increasing MW of linear segments yields a lower storage modulus at the rubbery plateau after softening above the glass transition (Tg ), both Tg and the characteristic time of stress relaxation are independently governed by the conformational entropy of the embodied linear segments. Activation energies for bond exchange in the solid state are lower for networks incorporating flexible chains; the network topology freezing temperature decreases with increasing MW of flexible linear segments but increases with increasing MW of stiff segments. Vitrimer reconfigurability is therefore influenced not only by the energetics of bond exchange for a given network density, but also the entropy of polymer chains within the network

Kepler Observations of V447 Lyr: An Eclipsing U Gem Cataclysmic Variable

We present the results of an analysis of data covering 1.5 years of the dwarf nova V447 Lyr. We detect eclipses of the accretion disk by the mass donating secondary star every 3.74 hrs which is the binary orbital period. V447 Lyr is therefore the first dwarf nova in the Kepler field to show eclipses. We also detect five long outbursts and six short outbursts showing V447 Lyr is a U Gem type dwarf nova. We show that the orbital phase of the mid-eclipse occurs earlier during outbursts compared to quiescence and that the width of the eclipse is greater during outburst. This suggests that the bright spot is more prominent during quiescence and that the disk is larger during outburst than quiescence. This is consistent with an expansion of the outer disk radius due to the presence of high viscosity material associated with the outburst, followed by a contraction in quiescence due to the accretion of low angular momentum material. We note that the long outbursts appear to be triggered by a short outburst, which is also observed in the super-outbursts of SU UMa dwarf novae as observed using Kepler.Comment: Accepted by MNRA

Epeoloides pilosulus (Cresson) Rediscovered in Michigan, with Notes on the Distribution and Status of its Macropis hosts.

Epeoloides pilosulus (Cresson 1878) is one of the rarest bees in North America with only a handful of records since 1960. The last collection in Michigan was made in 1944. Epeoloides pilosulus is a brood parasite of Macropis bees, which until recently had not been collected in Michigan for several decades. Bee surveys in Midland County, Michigan have led to the rediscovery of E. pilosulus in this state – the first record in 74 years. Michigan becomes the fourth state where E. pilosulus has been rediscovered after Connecticut in 2006, New York in 2014 and Maine in 2016, and the sixth region in North America after Nova Scotia in 2002 and Alberta in 2010. State-wide bee surveys have also shown that the principal host, Macropis nuda (Provancher 1882), remains widespread in Michigan, and that Macropis patellata Patton 1880 is newly recorded for the state

Description of the cloud layer experiment (CLEX), field phase, surface data archive

December 1996.Includes bibliographical references.Sponsored by the DOD Center for Geosciences, Phase II grant DAAHO4-94-G-0420

The reality of cross-disciplinary energy research in the United Kingdom:a social science perspective

Cross-disciplinary research is essential in understanding and reducing energy usage, however the reality of this collaboration comes with many challenges. This paper provides an insight into the integration of social science in energy research, drawing on the expertise and first hand experiences of a range of social science researchers (predominantly Early Career Researchers (ECRs)) working on UK cross-disciplinary projects in energy demand. These researchers, participants in a workshop dedicated to understanding the integration of social science in energy research, identified four groups of challenges to successful integration: Differing expectations of the role of social scientists; Working within academia; Feeling like a valued member of the team; and Communicating and comprehension between disciplines. Suggestions of how to negotiate those challenges included: Management and planning; Increasing contact; Sharing experience; and Understanding team roles. The paper offers a definition of ‘success’ in cross-disciplinary energy research from the perspective of social science ECRs, comprising external, internal and personal components. Using the logics of interdisciplinarity, this paper suggests that integration of the social sciences in the projects discussed may be partial at best and highlights a need to recognise the challenges ECRs face, in order to achieve full integration and equality of disciplines