HilE regulates HilD by blocking DNA binding in Salmonella enterica serovar Typhimurium

ABSTRACT The Salmonella type three secretion system (T3SS), encoded in the Salmonella pathogenicity island 1 (SPI1) locus, mediates the invasion of the host intestinal epithelium. SPI1 expression is dependent upon three AraC-like regulators: HilD, HilC, and RtsA. These regulators act in a complex feed-forward loop to activate each other and hilA , which encodes the activator of the T3SS structural genes. HilD has been shown to be the major integration point of most signals known to activate the expression of the SPI1 T3SS, acting as a switch to control induction of the system. HilE is a negative regulator that acts upon HilD. Here we provide genetic and biochemical data showing that HilE specifically binds to HilD but not to HilC or RtsA. This protein-protein interaction blocks the ability of HilD to bind DNA as shown by both an in vivo reporter system and an in vitro gel shift assay. HilE does not affect HilD dimerization, nor does it control the stability of the HilD protein. We also investigated the role of HilE during the infection of mice using competition assays. Although deletion of hilE does not confer a phenotype, the hilE mutation does suppress the invasion defect conferred by loss of FliZ, which acts as a positive signal controlling HilD protein activity. Together, these data suggest that HilE functions to restrict low-level HilD activity, preventing premature activation of SPI1 until positive inputs reach a threshold required to fully induce the system. IMPORTANCE Salmonella is a leading cause of gastrointestinal and systemic disease throughout the world. The SPI1 T3SS is required for Salmonella to induce inflammatory diarrhea and to gain access to underlying tissue. A complex regulatory network controls expression of SPI1 in response to numerous physiological inputs. Most of these signals impinge primarily on HilD translation or activity. The system is triggered when HilD activity crosses a threshold that allows efficient activation of its own promoter. This threshold is set by HilE, which binds to HilD to prevent the inevitable minor fluctuations in HilD activity from inappropriately activating the system. The circuit also serves as a paradigm for systems that must integrate numerous environmental parameters to control regulatory output. </jats:p

Student interpreters show encoding and recall differences for information in English and American Sign Language

This study investigated whether student interpreters encode and recall words differently in signed and spoken languages. Participants viewed and then recalled word lists, half of which were related through specific encoding strategies (i.e., experimental lists), and half of which lacked the availability of those strategies (i.e., control lists). Total words recalled and the temporal recall order were compared across experimental and control lists. Student interpreters utilised different strategies to remember words in English and American Sign Language (ASL), suggesting that student interpreters do not default to first-language (English) spoken strategies when encoding second-language (ASL) signed lists. However, the total number of recalled words was lower in ASL than in English despite students’ use of encoding strategies in ASL that have been shown to be adaptive to signed languages. These findings underscore the need to provide memory training to student interpreters in order to improve recall ability as part of interpreter education

Bantam System Technology Project Ground System Operations Concept and Plan

The Low Cost Booster Technology Program, also known as the Bantam Booster program, is a NASA sponsored initiative to establish a viable commercial technology to support the market for placing small payloads in low earth orbit. This market is currently served by large boosters which orbit a number of small payloads on a single launch vehicle, or by these payloads taking up available space on major commercial launches. Even by sharing launch costs, the minimum cost to launch one of these small satellites is in the 6 to 8 million dollar range. Additionally, there is a shortage of available launch opportunities which can be shared in this manner. The goal of the Bantam program is to develop two competing launch vehicles, with launch costs in the neighborhood of 1.5 million dollars to launch a 150 kg payload into low earth orbit (200 nautical mile sun synchronous). Not only could the cost of the launch be significantly less than the current situation, but the payload sponsor could expect better service for his expenditure, the ability to specify his own orbit, and a dedicated vehicle. By developing two distinct launch vehicles, market forces are expected to aid in keeping customer costs low

Adrenal involvement in the biostimulatory effect of bulls

<p>Abstract</p> <p>Background</p> <p>The objective was to evaluate if cortisol concentrations are associated with the resumption of luteal activity in postpartum, primiparous cows exposed to bulls. The hypotheses were that 1) interval from start of exposure to resumption of luteal activity; 2) proportions of cows that resumed luteal function during the exposure period; and 3) cortisol concentrations do not differ among cows exposed or not exposed to bulls (Exp. 1), and cows continuously exposed to bull or steer urine (Exp. 2).</p> <p>Methods</p> <p>In Exp. 1, 28 anovular cows were exposed (BE; n = 13) or not exposed (NE; n = 15) to bulls for 30 d at 58 d after calving. In Exp. 2, 38 anovular cows were fitted with a controlled urine delivery device at 45 d after calving and exposed continuously (24 h/d) to bull (BUE; n = 19) or steer (SUE; n = 19) urine. Length of exposure was ~64 d. Blood samples were collected from each cow on D 0 and every 3 d throughout exposure periods in both experiments and assayed for progesterone. Cortisol was assayed in samples collected on D 0, 8, 16, and 24 in Exp. 1; and, D 0, 19, 38, and 57 in Exp. 2.</p> <p>Results</p> <p>In Exp. 1, interval from the start of exposure to resumption of luteal activity was shorter (P < 0.05) for BE cows than NE cows, similarly, more (P < 0.05) BE cows than NE cows resumed luteal function during the exposure period. In Exp. 2, there was no difference in intervals from the start of exposure to resumption of luteal activity and proportions of cows that resumed luteal function during the exposure period between BUE and SUE cows. In Exp. 1, there was no difference in cortisol concentrations between BE and NE cows at the start of the experiment (D 0), however, cortisol concentrations were greater (P < 0.05) in BE cows than NE cows on D 9, 18, and 27. In Exp. 2, cortisol concentrations were higher for BUE than SUE cows on D 0 (P < 0.05), thereafter cortisol decreased (P < 0.05) but did not differ between BUE and SUE cows.</p> <p>Conclusion</p> <p>We conclude that the physical presence of bulls stimulates resumption of luteal activity and is coincident with increased cortisol concentrations, and hypothesize a possible association between adrenal activation and the biostimulatory effect of bulls.</p

Zwitterionic Surfactant as a Promising Non‐Cytotoxic Carrier for Nanoemulsion‐Based Vaccine Development

Motivated by the lack of noncytotoxic carriers in the current vaccine, we pursued the possibility of using a zwitterionic surfactant as a carrier to improve their delivery efficiency with antigen for a nanoemulsion‐based vaccine. We identified that a nanoemulsion formulation that consists of a specific zwitterionic surfactant can effectively mediate cellular uptake of antigen despite not having cytotoxicity as compared to a nanoemulsion that consists of a cationic surfactant. We report here the first study of a zwitterionic surfactant that consists of a positive charge in the outer layer of the polar head group and a hydrophobic tail is a promising approach for enhancing the carrier’s efficacy with no noticeable toxicity under experimental condition. However, zwitterionic surfactant that has positive charge in the outer layer with additional hydrophobicity due to the presence of aromatic ring had minimal cellular uptake and transfection efficacy.We report a nanoemulsion consists of a zwitterionic surfactant can effectively mediate cellular uptake of antigen despite not having cytotoxicity as compared to a NE consists of a cationic surfactant. ZI surfactant consists of a polar head, with positive charge in the outer layer has implications of developing next generation carrier to enhance the carrier‘s efficacy while improving tolerability for the development of NE‐based vaccine.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151273/1/slct201902737_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151273/2/slct201902737.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151273/3/slct201902737-sup-0001-misc_information.pd

Natural variation in abiotic stress responsive gene expression and local adaptation to climate in Arabidopsis thaliana.

Gene expression varies widely in natural populations, yet the proximate and ultimate causes of this variation are poorly known. Understanding how variation in gene expression affects abiotic stress tolerance, fitness, and adaptation is central to the field of evolutionary genetics. We tested the hypothesis that genes with natural genetic variation in their expression responses to abiotic stress are likely to be involved in local adaptation to climate in Arabidopsis thaliana. Specifically, we compared genes with consistent expression responses to environmental stress (expression stress responsive, "eSR") to genes with genetically variable responses to abiotic stress (expression genotype-by-environment interaction, "eGEI"). We found that on average genes that exhibited eGEI in response to drought or cold had greater polymorphism in promoter regions and stronger associations with climate than those of eSR genes or genomic controls. We also found that transcription factor binding sites known to respond to environmental stressors, especially abscisic acid responsive elements, showed significantly higher polymorphism in drought eGEI genes in comparison to eSR genes. By contrast, eSR genes tended to exhibit relatively greater pairwise haplotype sharing, lower promoter diversity, and fewer nonsynonymous polymorphisms, suggesting purifying selection or selective sweeps. Our results indicate that cis-regulatory evolution and genetic variation in stress responsive gene expression may be important mechanisms of local adaptation to climatic selective gradients

Corpus Linguistics and the Original Public Meaning of the Sixteenth Amendment

Moore v. United States raises the question whether unrealized gains, such as an increase in property value or a stock portfolio, constitute “incomes, from whatever source derived” under the original meaning of the Sixteenth Amendment. Moore is widely viewed as the most important tax case to reach the United States Supreme Court in decades. It is also an opportunity for the Court to refine its theory and method of finding original meaning. We focus here on the original public meaning of the Sixteenth Amendment—the ordinary, common meaning attributed to its text by the general public in 1913. So far, the parties and amici have relied on contemporaneous dictionaries to argue over such meaning. But the cited dictionaries do not establish the ordinary meaning of “incomes, from whatever source derived”; instead, they highlight a key ambiguity in the very terms of the definitions presented. This article fills important gaps in the original public meaning analysis in Moore. More broadly, it also charts a path for refining the theory and methodology of the originalist inquiry more generally. At the theoretical level, it introduces principles of the philosophy of language and theoretical linguistics that align with—and help refine—strands of the Court’s originalist inquiry. And as to method, it introduces evidence from corpus linguistic analysis to provide a transparent, replicable basis for assessing the ordinary public meaning of the Sixteenth Amendment’s relevant terms. We use the Corpus of Historical American English (“COHA”) to analyze the ordinary public meaning of the constitutional language at the time of ratification of the Sixteenth Amendment. At the “words-to-meaning” level, we show that “income(s)” was always used in 1900-1912 to refer to realized gains. We also perform a “meaning-to-words” analysis, showing that unrealized gains were always referred to using terms other than “income(s).” Our corpus linguistic analysis reveals that the original public meaning of “incomes, from whatever source derived” almost certainly only covers realized gains. And it charts a path for greater transparency, objectivity, and replicability than more traditional tools of originalism

Pleiotropy of FRIGIDA enhances the potential for multivariate adaptation.

An evolutionary response to selection requires genetic variation; however, even if it exists, then the genetic details of the variation can constrain adaptation. In the simplest case, unlinked loci and uncorrelated phenotypes respond directly to multivariate selection and permit unrestricted paths to adaptive peaks. By contrast, 'antagonistic' pleiotropic loci may constrain adaptation by affecting variation of many traits and limiting the direction of trait correlations to vectors that are not favoured by selection. However, certain pleiotropic configurations may improve the conditions for adaptive evolution. Here, we present evidence that the Arabidopsis thaliana gene FRI (FRIGIDA) exhibits 'adaptive' pleiotropy, producing trait correlations along an axis that results in two adaptive strategies. Derived, low expression FRI alleles confer a 'drought escape' strategy owing to fast growth, low water use efficiency and early flowering. By contrast, a dehydration avoidance strategy is conferred by the ancestral phenotype of late flowering, slow growth and efficient water use during photosynthesis. The dehydration avoidant phenotype was recovered when genotypes with null FRI alleles were transformed with functional alleles. Our findings indicate that the well-documented effects of FRI on phenology result from differences in physiology, not only a simple developmental switch

Analytical Method of Approximating the Motion of a Spinning Vehicle with Variable Mass and Inertia Properties Acted Upon by Several Disturbing Parameters

An analytical method has been developed which approximates the dispersion of a spinning symmetrical body in a vacuum, with time-varying mass and inertia characteristics, under the action of several external disturbances-initial pitching rate, thrust misalignment, and dynamic unbalance. The ratio of the roll inertia to the pitch or yaw inertia is assumed constant. Spin was found to be very effective in reducing the dispersion due to an initial pitch rate or thrust misalignment, but was completely Ineffective in reducing the dispersion of a dynamically unbalanced body

A programme for risk assessment and minimisation of progressive multifocal leukoencephalopathy developed for vedolizumab clinical trials

Introduction Over the past decade, the potential for drug-associated progressive multifocal leukoencephalopathy (PML) has become an increasingly important consideration in certain drug development programmes, particularly those of immunomodulatory biologics. Whether the risk of PML with an investigational agent is proven (e.g. extrapolated from relevant experience, such as a class effect) or merely theoretical, the serious consequences of acquiring PML require careful risk minimisation and assessment. No single standard for such risk minimisation exists. Vedolizumab is a recently developed monoclonal antibody to α4β7 integrin. Its clinical development necessitated a dedicated PML risk minimisation assessment as part of a global preapproval regulatory requirement. Objective The aim of this study was to describe the multiple risk minimisation elements that were incorporated in vedolizumab clinical trials in inflammatory bowel disease patients as part of the risk assessment and minimisation of PML programme for vedolizumab. Methods A case evaluation algorithm was developed for sequential screening and diagnostic evaluation of subjects who met criteria that indicated a clinical suspicion of PML. An Independent Adjudication Committee provided an independent, unbiased opinion regarding the likelihood of PML. Results Although no cases were detected, all suspected PML events were thoroughly reviewed and successfully adjudicated, making it unlikely that cases were missed. Conclusion We suggest that this programme could serve as a model for pragmatic screening for PML during the clinical development of new drugs