119 research outputs found

    CsrA impacts survival of Yersinia enterocolitica by affecting a myriad of physiological activities.

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    BackgroundA previous study identified a Yersinia enterocolitica transposon mutant, GY448, that was unable to export the flagellar type three secretion system (T3SS)-dependent phospholipase, YplA. This strain was also deficient for motility and unable to form colonies on Lauria-Bertani agar medium. Preliminary analysis suggested it carried a mutation in csrA. CsrA in Escherichia coli is an RNA-binding protein that is involved in specific post-transcriptional regulation of a myriad of physiological activities. This study investigated how CsrA affects expression of the flagellar regulatory cascade that controls YplA export and motility. It also explored the effect of csrA mutation on Y. enterocolitica in response to conditions that cue physiological changes important for growth in environments found both in nature and the laboratory.ResultsThe precise location of the transposon insertion in GMY448 was mapped within csrA. Genetic complementation restored disruptions in motility and the YplA export phenotype (Yex), which confirmed this mutation disrupted CsrA function. Mutation of csrA affected expression of yplA and flagellar genes involved in flagellar T3SS dependent export and motility by altering expression of the master regulators flhDC. Mutation of csrA also resulted in increased sensitivity of Y. enterocolitica to various osmolytes, temperatures and antibiotics.ConclusionsThe results of this study reveal unique aspects of how CsrA functions in Y. enterocolitica to control its physiology. This provides perspective on how the Csr system is susceptible to adaptation to particular environments and bacterial lifestyles

    Piloting of the Concerns-based Adoption Model: Farmer Concerns About the Participatory Guarantee System in Cambodia

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    While there is a large body of adoption and agricultural extension literature on the process of introducing a new technology, agricultural development projects are often expected to produce immediate results that do not always allow for the integration of these theories into practice. The Concerns-based Adoption Model (CBAM) is a framework that places participants at the center of the change process to identify their concerns and challenges, providing a roadmap for projects to guide individuals with the correct support for their particular stage of adoption. CBAM has typically been used for the introduction of new curriculum in formal education. But this study assessed the potential for CBAM to be applied to agriculture innovations. In this study, we adapted and piloted the CBAM “Stages of Concern” model to assess adoption of an agriculture innovation. The innovation is the Participatory Guarantee System (PGS) for Cambodian vegetable farmers. We assessed the potential for CBAM as a tool for agricultural development project management. We found that the adapted survey consistently placed farmers in the anticipated Stage of Concern. Identifying users’ Stages of Concern can inform program designers and practitioners, assisting in tailoring support across the adoption process. CBAM has the potential to inform participatory project design and give project administrators an evidence-based, systematic protocol for assessing the adoption process, adding another tool to the development practitioners’ toolbox

    Influence de l'accessibilité des ressources anthropiques sur les paramÚtres reproducteurs de deux colonies de Goélands leucophées Larus michahellis

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    Cette Ă©tude a consistĂ© Ă  suivre la chronologie de reproduction et les paramĂštres reproducteurs (taille des pontes, volume des oeufs, taux d'Ă©closion et taux de survie des poussins) de deux colonies de GoĂ©lands leucophĂ©es Larus michahellis prĂ©sentant dans leur environnement proche une accessibilitĂ© aux ressources anthropiques nettement diffĂ©rente. Ainsi, l'une des colonies sĂ©lectionnĂ©es, Ă©tablie sur l'Ăźle de Ratonneau, est situĂ©e Ă  proximitĂ© immĂ©diate du continent et des importantes dĂ©charges pĂ©ri-marseillaises, tandis que la seconde colonie, implantĂ©e sur l'Ăźle de Bagaud, est Ă©loignĂ©e de prĂšs de 30 km de la dĂ©charge la plus proche. La chronologie de ponte du premier oeuf montre l'existence d'un dĂ©calage phĂ©nologique significatif entre les deux colonies. Bien que les tailles moyennes de pontes (nombre moyen d'oeufs par nid) ne soient pas significativement diffĂ©rentes, la frĂ©quence des pontes complĂštes (de 3 oeufs) est plus Ă©levĂ©e lorsque l'accessibilitĂ© aux ressources est supĂ©rieure. Le volume moyen des oeufs est significativement diffĂ©rent entre les deux colonies, particuliĂšrement en ce qui concerne le troisiĂšme oeuf, qui s'avĂšre nettement plus petit pour la colonie ayant le moins accĂšs aux ressources alimentaires anthropiques. De mĂȘme, les taux d'Ă©closion et les taux de survie des poussins sont significativement infĂ©rieurs pour la colonie de Bagaud. Ainsi, ces disparitĂ©s dans les paramĂštres reproducteurs semblent pouvoir ĂȘtre reliĂ©es Ă  des diffĂ©rences notables d'accessibilitĂ© aux ressources alimentaires, expliquant en partie la nette diffĂ©rence de dynamique dĂ©mographique des deux colonies observĂ©e sur les vingt derniĂšres annĂ©es. Enfin, ces rĂ©sultats devraient permettre de calibrer plus justement les modĂšles dĂ©mographiques destinĂ©s Ă  orienter les opĂ©rations de gestion des populations de cette espĂšce parfois surabondante.This study aims at determining breeding chronology and reproductive parameters (clutch-size, egg volume, hatching success and chick survival rates) in two Yellow-legged Gull Larus michahellis colonies showing a marked difference in anthropogenic food resources accessibility. For instance, one of the colonies studied, established on Ratonneau island, is very close to the large refuse dumps of Marseille city white the other, established on Bagaud island, is 30 km distant from the nearest refuse dump. The mean laying date of the first egg showed a significant difference between the two colonies. Although mean clutch-size does not significantly differ between the two colonies, complete 3-egg clutches were more frequent at Ratonneau. Mean egg volume was significantly different between the two colonies with a markedly smaller volume for the C-egg in the colony that was farther from human food sources. Moreover, hatching success and chick survival rates were significantly lower on Bagaud than on Ratonneau. All these differences may be linked to marked differences in resource accessibility, and in this way, anthropogenic food resources accessibility may be partly responsible for the clear difference in the demographic patterns of the two colonies for the last twenty years. These results could be used to calibrate more accurately certain demographic modelling in order to improve the population management of this superabundant bird species

    Consistency in microbiomes in cultures of Alexandrium species isolated from brackish and marine waters

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    Phytoplankton and bacteria interactions have a significant role in aquatic ecosystem functioning. Associations can range from mutualistic to parasitic, shaping biogeochemical cycles and having a direct influence on phytoplankton growth. How variations in phenotype and sampling location, affect the phytoplankton microbiome is largely unknown. A high-resolution characterization of the bacterial community in cultures of the dinoflagellate Alexandrium was performed on strains isolated from different geographical locations and at varying anthropogenic impact levels. Microbiomes of Baltic Sea Alexandrium ostenfeldii isolates were dominated by Betaproteobacteria and were consistent over phenotypic and genotypic Alexandrium strain variation, resulting in identification of an A. ostenfeldii core microbiome. Comparisons with in situ bacterial communities showed that taxa found in this A. ostenfeldii core were specifically associated to dinoflagellate dynamics in the Baltic Sea. Microbiomes of Alexandrium tamarense and minutum, isolated from the Mediterranean Sea, differed from those of A. ostenfeldii in bacterial diversity and composition but displayed high consistency, and a core set of bacterial taxa was identified. This indicates that Alexandrium isolates with diverse phenotypes host predictable, species-specific, core microbiomes reflecting the abiotic conditions from which they were isolated. These findings enable in-depth studies of potential interactions occurring between Alexandrium and specific bacterial taxa

    Smear plus Detect-TB for a sensitive diagnosis of pulmonary tuberculosis: a cost-effectiveness analysis in an incarcerated population

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    Background: Prison conditions can favor the spread of tuberculosis (TB). This study aimed to evaluate in a Brazilian prison: the performance and accuracy of smear, culture and Detect-TB; performance of smear plus culture and smear plus Detect-TB, according to different TB prevalence rates; and the cost-effectiveness of these procedures for pulmonary tuberculosis (PTB) diagnosis. Methods: This paper describes a cost-effectiveness study. A decision analytic model was developed to estimate the costs and cost-effectiveness of five routine diagnostic procedures for diagnosis of PTB using sputum specimens: a) Smear alone, b) Culture alone, c) Detect-TB alone, d) Smear plus culture and e) Smear plus Detect-TB. The cost-effectiveness ratio of costs were evaluated per correctly diagnosed TB case and all procedures costs were attributed based on the procedure costs adopted by the Brazilian Public Health System. Results: A total of 294 spontaneous sputum specimens from patients suspected of having TB were analyzed. The sensibility and specificity were calculated to be 47% and 100% for smear; 93% and 100%, for culture; 74% and 95%, for Detect-TB; 96% and 100%, for smear plus culture; and 86% and 95%, for smear plus Detect-TB. The negative and positive predictive values for smear plus Detect-TB, according to different TB prevalence rates, ranged from 83 to 99% and 48 to 96%, respectively. In a cost-effectiveness analysis, smear was both less costly and less effective than the other strategies. Culture and smear plus culture were more effective but more costly than the other strategies. Smear plus Detect-TB was the most cost-effective method. Conclusions: The Detect-TB evinced to be sensitive and effective for the PTB diagnosis when applied with smear microscopy. Diagnostic methods should be improved to increase TB case detection. To support rational decisions about the implementation of such techniques, cost-effectiveness studies are essential, including in prisons, which are known for health care assessment problems

    Two Chromogranin A-Derived Peptides Induce Calcium Entry in Human Neutrophils by Calmodulin-Regulated Calcium Independent Phospholipase A2

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    Background: Antimicrobial peptides derived from the natural processing of chromogranin A (CgA) are co-secreted with catecholamines upon stimulation of chromaffin cells. Since PMNs play a central role in innate immunity, we examine responses by PMNs following stimulation by two antimicrobial CgA-derived peptides. Methodology/Principal Findings: PMNs were treated with different concentrations of CgA-derived peptides in presence of several drugs. Calcium mobilization was observed by using flow cytometry and calcium imaging experiments. Immunocytochemistry and confocal microscopy have shown the intracellular localization of the peptides. The calmodulin-binding and iPLA2 activating properties of the peptides were shown by Surface Plasmon Resonance and iPLA2 activity assays. Finally, a proteomic analysis of the material released after PMNs treatment with CgA-derived peptides was performed by using HPLC and Nano-LC MS-MS. By using flow cytometry we first observed that after 15 s, in presence of extracellular calcium, Chromofungin (CHR) or Catestatin (CAT) induce a concentration-dependent transient increase of intracellular calcium. In contrast, in absence of extra cellular calcium the peptides are unable to induce calcium depletion from the stores after 10 minutes exposure. Treatment with 2-APB (2-aminoethoxydiphenyl borate), a store operated channels (SOCs) blocker, inhibits completely the calcium entry, as shown by calcium imaging. We also showed that they activate iPLA2 as the two CaM-binding factors (W7 and CMZ) and that the two sequences can be aligned with the two CaMbinding domains reported for iPLA2. We finally analyzed by HPLC and Nano-LC MS-MS the material released by PMNs following stimulation by CHR and CAT. We characterized several factors important for inflammation and innate immunity. Conclusions/Significance: For the first time, we demonstrate that CHR and CAT, penetrate into PMNs, inducing extracellular calcium entry by a CaM-regulated iPLA2 pathway. Our study highlights the role of two CgA-derived peptides in the active communication between neuroendocrine and immune systems

    Processes of local alcohol policy-making in England: Does the theory of policy transfer provide useful insights into public health decision-making?

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    BACKGROUND AND AIMS: Recent years have seen a rise in new and innovative policies to reduce alcohol consumption and related harm in England, which can be implemented by local, as opposed to national, policy-makers. The aim of this paper is to explore the processes that underpin the adoption of these alcohol policies within local authorities. In particular, it aims to assess whether the concept of policy transfer (i.e. a process through which knowledge about policies in one place is used in the development of policies in another time or place) provides a useful model for understanding local alcohol policy-making. METHODS: Qualitative data generated through in-depth interviews and focus groups from five case study sites across England were used to explore stakeholder experiences of alcohol policy transfer between local authorities. The purposive sample of policy actors included representatives from the police, trading standards, public health, licensing, and commissioning. Thematic analysis was used inductively to identify key features in the data. RESULTS: Themes from the policy transfer literature identified in the data were: policy copying, emulating, hybridization, and inspiration. Participants described a multitude of ways in which learning was shared between places, ranging from formal academic evaluation to opportunistic conversations in informal settings. Participants also described facilitators and constraints to policy transfer, such as the historical policy context and the local cultural, economic, and bureaucratic context, which influenced whether or not a policy that was perceived to work in one place might be transferred successfully to another context. CONCLUSIONS: Theories of policy transfer provide a promising framework for characterising processes of local alcohol policy-making in England, extending beyond debates regarding evidence-informed policy to account for a much wider range of considerations. Applying a policy transfer lens enables us to move beyond simple (but still important) questions of what is supported by 'robust' research evidence by paying greater attention to how policy making is carried out in practice and the multiple methods by which policies diffuse across jurisdictions

    The FANCM:p.Arg658* truncating variant is associated with risk of triple-negative breast cancer

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    Abstract: Breast cancer is a common disease partially caused by genetic risk factors. Germline pathogenic variants in DNA repair genes BRCA1, BRCA2, PALB2, ATM, and CHEK2 are associated with breast cancer risk. FANCM, which encodes for a DNA translocase, has been proposed as a breast cancer predisposition gene, with greater effects for the ER-negative and triple-negative breast cancer (TNBC) subtypes. We tested the three recurrent protein-truncating variants FANCM:p.Arg658*, p.Gln1701*, and p.Arg1931* for association with breast cancer risk in 67,112 cases, 53,766 controls, and 26,662 carriers of pathogenic variants of BRCA1 or BRCA2. These three variants were also studied functionally by measuring survival and chromosome fragility in FANCM−/− patient-derived immortalized fibroblasts treated with diepoxybutane or olaparib. We observed that FANCM:p.Arg658* was associated with increased risk of ER-negative disease and TNBC (OR = 2.44, P = 0.034 and OR = 3.79; P = 0.009, respectively). In a country-restricted analysis, we confirmed the associations detected for FANCM:p.Arg658* and found that also FANCM:p.Arg1931* was associated with ER-negative breast cancer risk (OR = 1.96; P = 0.006). The functional results indicated that all three variants were deleterious affecting cell survival and chromosome stability with FANCM:p.Arg658* causing more severe phenotypes. In conclusion, we confirmed that the two rare FANCM deleterious variants p.Arg658* and p.Arg1931* are risk factors for ER-negative and TNBC subtypes. Overall our data suggest that the effect of truncating variants on breast cancer risk may depend on their position in the gene. Cell sensitivity to olaparib exposure, identifies a possible therapeutic option to treat FANCM-associated tumors
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