Salmonella enterica: a surprisingly well-adapted intracellular lifestyle

The infectious intracellular lifestyle of Salmonella enterica relies on the adaptation to nutritional conditions within the Salmonella-containing vacuole (SCV) in host cells. We summarize latest results on metabolic requirements for Salmonella during infection. This includes intracellular phenotypes of mutant strains based on metabolic modeling and experimental tests, isotopolog profiling using (13)C-compounds in intracellular Salmonella, and complementation of metabolic defects for attenuated mutant strains towards a comprehensive understanding of the metabolic requirements of the intracellular lifestyle of Salmonella. Helpful for this are also genomic comparisons. We outline further recent studies and which analyses of intracellular phenotypes and improved metabolic simulations were done and comment on technical required steps as well as progress involved in the iterative refinement of metabolic flux models, analyses of mutant phenotypes, and isotopolog analyses. Salmonella lifestyle is well-adapted to the SCV and its specific metabolic requirements. Salmonella metabolism adapts rapidly to SCV conditions, the metabolic generalist Salmonella is quite successful in host infection

Lifetime Lubricant Use among a Nationally Representative Sample of Lesbian- and Bisexual-Identified Women in the United States

Introduction The diversity in self-identified lesbian and bisexual women's sexual interactions necessitates better understanding of how and when they integrate personal lubricant into different experiences. However, little is known about lesbian and bisexual women's lifetime lubricant use, particularly at the population level. Aims The aim of this study was to examine the prevalence and characteristics of lubricant use among adult lesbian and bisexual women in the United States. Methods Data were drawn from a subset of lesbian and bisexual participants who participated in the 2012 National Survey of Sexual Health and Behavior, an online questionnaire administered to a nationally representative probability sample of U.S. adults ages 18 and older. Main Outcome Measures We examined socio-demographic characteristics, recent and lifetime lubricant use, lubricant use in associated with specific sexual behaviors and condom use, frequency of use, motivations for use, as well as perception of lubricant when used. Results A majority of lesbian- (60.1%) and bisexual-identified (77.1%) women reported ever using lubricant; 25.7% of lesbian women and 32.7% of bisexual women used it in the last 30 days. Across most age groups, lubricant was commonly used during partnered sexual play, partnered sexual intercourse, or when a vibrator/dildo was used. Lesbian and bisexual women reported using lubricants to increase arousal/sexual pleasure/desire, to make sex more fun, or to increase physical comfort during sex. Conclusions Lubricant use is identified as a part of lesbian and bisexual women's sexual experience across the life span, as a part of both solo and partnered experiences. As part of evolving sexual health assessments, clinicians and health educators may find value in integrating lubricant-focused conversation with their lesbian and bisexual patients and clients, particularly

Green Aerospace Fuels from Nonpetroleum Sources

Efforts to produce green aerospace propellants from nonpetroleum sources are outlined. The paper begins with an overview of feedstock processing and relevant small molecule or C1 chemistry. Gas-to-liquid technologies, notably Fischer-Tropsch (FT) processing of synthesis gas (CO and H2), are being optimized to enhance the fraction of product stream relevant to aviation (and other transportation) fuels at the NASA Glenn Research Center (GRC). Efforts to produce optimized catalysts are described. Given the high cost of space launch, the recycling of human metabolic and plastic wastes to reduce the need to transport consumables to orbit to support the crew of a space station has long been recognized as a high priority. If the much larger costs of transporting consumables to the Moon or beyond are taken into account, the importance of developing waste recycling systems becomes still more imperative. One promising way to transform organic waste products into useful gases is steam reformation; this well-known technology is currently being optimized by a Colorado company for exploration and planetary surface operations. Reduction of terrestrial waste streams while producing energy and/or valuable raw materials is an opportunity being realized by a new generation of visionary entrepreneurs. A technology that has successfully demonstrated production of fuels and related chemicals from waste plastics developed in Northeast Ohio is described. Technologies being developed by a Massachusetts company to remove sulfur impurities are highlighted. Common issues and concerns for nonpetroleum fuel production are emphasized. Energy utilization is a concern for production of fuels whether a terrestrial operation or on the lunar (or Martian) surface; the term green relates to not only mitigating excess carbon release but also to the efficiency of grid-energy usage. For space exploration, energy efficiency can be an essential concern. Other issues of great concern include minimizing impurities in the product stream(s), especially those that potential health risks and/or could degrade operations through catalyst poisoning or equipment damage. The potential impacts on future missions by such concerns are addressed in closing

Singular Coexistence-curve Diameters: Experiments and Simulations

Precise calculations of the coexistence-curve diameters of a hard-core square-we ll (HCSW) fluid and the restricted primitive model (RPM) electrolyte exhibit mar ked deviations from rectilinear behavior. The HCSW diameter displays a $|t|^{1- alpha}$ singularity that sets in sharply for $|t|\equiv |T-T_c|/T_c\lesssim 10^{-3}$; this compares favorably with extensive data for ${SF}_6$, also reflec ted in C$_2$H$_6$, N$_2$, etc. By contrast, the curvature of the RPM diameter va ries slowly over a wide range $|t|\lesssim 0.1$; this behavior mirrors observati ons for liquid alkali metals, specifically Rb and Cs. Amplitudes for the leading singular terms can be estimated numerically but their values cannot be taken li terally.Comment: 9 pages and 4 figure

The crystal structure of the C-terminal domain of the salmonella enterica pduo protein: An old fold with a new heme-binding mode

The two-domain protein PduO, involved in 1,2-propanediol utilization in the pathogenic Gram-negative bacterium Salmonella enterica is an ATP:Cob(I)alamin adenosyltransferase, but this is a function of the N-terminal domain alone. The role of its C-terminal domain (PduOC) is, however, unknown. In this study, comparative growth assays with a set of Salmonella mutant strains showed that this domain is necessary for effective in vivo catabolism of 1,2-propanediol. It was also shown that isolated, recombinantly-expressed PduOC binds heme in vivo. The structure of PduOC co-crystallized with heme was solved (1.9 \uc5 resolution) showing an octameric assembly with four heme moieities. The four heme groups are highly solvent-exposed and the heme iron is hexa-coordinated with bis-His ligation by histidines from different monomers. Static light scattering confirmed the octameric assembly in solution, but a mutation of the heme-coordinating histidine caused dissociation into dimers. Isothermal titration calorimetry using the PduOC apoprotein showed strong heme binding (Kd = 1.6 7 10 127 M). Biochemical experiments showed that the absence of the C-terminal domain in PduO did not affect adenosyltransferase activity in vitro. The evidence suggests that PduOC:heme plays an important role in the set of cobalamin transformations required for effective catabolism of 1,2-propanediol. Salmonella PduO is one of the rare proteins which binds the redox-active metabolites heme and cobalamin, and the heme-binding mode of the C-terminal domain differs from that in other members of this protein family

Analysis of T-DNA integration and generative segregation in transgenic winter triticale (x Triticosecale Wittmack)

BACKGROUND: While the genetic transformation of the major cereal crops has become relatively routine, to date only a few reports were published on transgenic triticale, and robust data on T-DNA integration and segregation have not been available in this species. RESULTS: Here, we present a comprehensive analysis of stable transgenic winter triticale cv. Bogo carrying the selectable marker gene HYGROMYCIN PHOSPHOTRANSFERASE (HPT) and a synthetic green fluorescent protein gene (gfp). Progeny of four independent transgenic plants were comprehensively investigated with regard to the number of integrated T-DNA copies, the number of plant genomic integration loci, the integrity and functionality of individual T-DNA copies, as well as the segregation of transgenes in T(1) and T(2) generations, which also enabled us to identify homozygous transgenic lines. The truncation of some integrated T-DNAs at their left end along with the occurrence of independent segregation of multiple T-DNAs unintendedly resulted in a single-copy segregant that is selectable marker-free and homozygous for the gfp gene. The heritable expression of gfp driven by the maize UBI-1 promoter was demonstrated by confocal laser scanning microscopy. CONCLUSIONS: The used transformation method is a valuable tool for the genetic engineering of triticale. Here we show that comprehensive molecular analyses are required for the correct interpretation of phenotypic data collected from the transgenic plants

Performance-oriented architecture : towards a biological paradigm for architectural design and the built environment

Open Access - This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the source is credited.This paper introduces and elaborates a specific approach to architectural design entitled ‘performance-oriented architecture’ based on a redefinition of the concept of ‘performance’ in relation to the discipline of architecture and set within a biological paradigm. The concept of ‘performance’ evolved out of a series of intellectual efforts that had broad consequences, bringing about a paradigm shift in the humanities referred to as the ‘performative turn’. These efforts commenced in the 1940s and 1950s and had significant impact also on the sciences, deriving what is referred to as the ‘performative idiom’. Here the question is raised as to what ‘performance’ in the context of architecture may entail. The approach introduced contrasts previous ones that focused either on questions of representation and meaning in architecture, or, alternatively that have treated performance as synonymous to function placed in the context of post-design functional optimisation. Contrasting these previous efforts performance is here reformulated as a driving concept for design that helps re-consolidate form and function into a synergetic relation with the dynamics of natural, cultural and social environments, and in so doing, locate performative capacity - ‘ active agency’ - in the spatial and material organisation of architecture, in the human subject and the environment through the dynamic interaction between these four domains. In pursuing this approach the potential of a close disciplinary affiliation between architecture and biology is examined, so as to locate a suitable paradigm for performance in the discipline of biology and its various sub-disciplines, in its various foci and modes of inquiry, and, moreover, in biological systems

Performance-oriented Architecture: Towards a Biological Paradigm for Architectural Design and the Built Environment

This paper introduces and elaborates a specific approach to architectural design entitled ‘performance-oriented architecture’ based on a redefinition of the concept of ‘performance’ in relation to the discipline of architecture and set within a biological paradigm. The concept of ‘performance’ evolved out of a series of intellectual efforts that had broad consequences, brining about a paradigm shift in the humanities referred to as the ‘performative turn’. These efforts commenced in the 1940s and 1950s and had significant impact also on the sciences, deriving what is referred to as the ‘performative idiom’. Here the question is raised as to what ‘performance’ in the context of architecture may entail. The approach introduced con­trasts previous ones that focused either on questions of representation and meaning in architecture, or, alternatively that have treated performance as synonymous to function placed in the context of post-design functional optimisation. Contrasting these previous efforts performance is here reformulated as a driving concept for design that helps re-con­solidate form and function into a synergetic relation with the dynamics of natural, cultural and social environments, and in so doing, locate performative capacity - ‘ active agency’ -  in  the spatial and material organisation of architecture, in the human subject and the environ­ment through the dynamic interaction between these four domains. In pursuing this approach the potential of a close disciplinary affiliation between architecture and biology is examined, so as to locate a suitable paradigm for performance in the discipline of biology and its var­ious sub-disciplines, in its various foci and modes of inquiry, and, moreover, in biological syst­ems.This paper introduces and elaborates a specific approach to architectural design entitled ‘performance-oriented architecture’ based on a redefinition of the concept of ‘performance’ in relation to the discipline of architecture and set within a biological paradigm. The concept of ‘performance’ evolved out of a series of intellectual efforts that had broad consequences, brining about a paradigm shift in the humanities referred to as the ‘performative turn’. These efforts commenced in the 1940s and 1950s and had significant impact also on the sciences, deriving what is referred to as the ‘performative idiom’. Here the question is raised as to what ‘performance’ in the context of architecture may entail. The approach introduced con­trasts previous ones that focused either on questions of representation and meaning in architecture, or, alternatively that have treated performance as synonymous to function placed in the context of post-design functional optimisation. Contrasting these previous efforts performance is here reformulated as a driving concept for design that helps re-con­solidate form and function into a synergetic relation with the dynamics of natural, cultural and social environments, and in so doing, locate performative capacity - ‘ active agency’ - in the spatial and material organisation of architecture, in the human subject and the environ­ment through the dynamic interaction between these four domains. In pursuing this approach the potential of a close disciplinary affiliation between architecture and biology is examined, so as to locate a suitable paradigm for performance in the discipline of biology and its var­ious sub-disciplines, in its various foci and modes of inquiry, and, moreover, in biological syst­ems

Data-driven design for Architecture and Environment Integration

Rapid urbanization and related land cover and land use changes are primary causes of climate change, and of environmental and ecosystem degradation. Sustainability problems are becoming increasingly complex due to these developments. At the same time vast amounts of data on urbanization, construction and resulting environmental conditions are being generated. Yet it is hardly possible to gain insights for sustainable plan-ning and design at the same rate as data is generated. Moreover, the complexity of compound sustainability problems requires interdisciplinary approaches that address multiple knowledge fields, multiple dynamics and multiple spatial, temporal and functional scales. This raises a question regarding methods and tools available to planners and architects for tackling these complex issues. To address this problem we are developing an interdisciplinary approach, computational framework and related workflows for multi-domain and trans-scalar modelling that integrate planning and design scales. For this article two lines of research were selected. The first focuses on understanding environments for the purpose of discovering, recovering and adapting land knowledge to different conditions and contexts. This entails an analytical data-integrated computational workflow. The second line of research focuses on designing environments and developing an approach and computational workflow for data-integrated planning and design. These two lines converge in a combined analytical and generative data-integrated computational workflow. This combined approach aims for an intense integration of architectures and environments that we call embedded architectures. In this article we discuss the two lines of research, their convergence, and further research questions

Excitonic condensate and quasiparticle transport in electron-hole bilayer systems

Bilayer electron-hole systems undergo excitonic condensation when the distance d between the layers is smaller than the typical distance between particles within a layer. All excitons in this condensate have a fixed dipole moment which points perpendicular to the layers, and therefore this condensate of dipoles couples to external electromagnetic fields. We study the transport properties of this dipolar condensate system based on a phenomenological model which takes into account contributions from the condensate and quasiparticles. We discuss, in particular, the drag and counterflow transport, in-plane Josephson effect, and noise in the in-plane currents in the condensate state which provides a direct measure of the superfluid collective-mode velocity.Comment: 7 pages, 3 figure