18 research outputs found

    Global Transcriptional Analysis of Spontaneous Sakacin P-Resistant Mutant Strains of Listeria monocytogenes during Growth on Different Sugars

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    Subclass IIa bacteriocins have strong antilisterial activity and can control the growth of Listeria monocytogenes in food. However, L. monocytogenes may develop resistance towards such bacteriocins. In this follow-up study, the transcriptomes of a high level (L502-1) and a low level (L502-6) spontaneous sakacin P-resistant mutant strain of L. monocytogenes were compared to the wild-type (L502). The growth of the resistant strains was reduced on mannose but not affected on cellobiose and the transcriptomics was performed during growth on these sugars. The mannose phosphotransferase system (PTS) encoded by the mptACD operon (mpt) is known for transporting mannose and also act as a receptor to class IIa bacteriocins. The mpt was repressed in L502-1 and this is in accordance with abolition of the bacteriocin receptor with resistance to class IIa bacteriocins. In contrast, the mpt was induced in L502-6. Despite the induction of the mpt, L502-6 showed 1,000 times more resistance phenotype and reduced growth on mannose suggesting the mannose-PTS may not be functional in L502-6. The microarray data suggests the presence of other transcriptional responses that may be linked to the sakacin P resistance phenotype particularly in L502-6. Most of commonly regulated genes encode proteins involved in transport and energy metabolism. The resistant strains displayed shift in general carbon catabolite control possibly mediated by the mpt. Our data suggest that the resistant strains may have a reduced virulence potential. Growth sugar- and mutant-specific responses were also revealed. The two resistant strains also displayed difference in stability of the sakacin P resistance phenotype, growth in the presence of both the lytic bacteriophage P100 and activated charcoal. Taken together, the present study showed that a single time exposure to the class IIa bacteriocin sakacin P may elicit contrasting phenotypic and transcriptome responses in L. monocytogenes possibly through regulation of the mpt

    Colouration and Colour Changes of the Fiddler Crab, Uca capricornis: A Descriptive Study

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    Colour changes in animals may be triggered by a variety of social and environmental factors and may occur over a matter of seconds or months. Crustaceans, like fiddler crabs (genus Uca), are particularly adept at changing their colour and have been the focus of numerous studies. However, few of these studies have attempted to quantitatively describe the individual variation in colour and pattern or their adaptive significance. This paper quantitatively describes the colour patterns of the fiddler crab Uca capricornis and their ability to change on a socially significant timescale. The most dramatic changes in colour pattern are associated with moulting. These ontogenetic changes result in a general reduction of the colour pattern with increasing size, although females are more colourful and variable than similarly-sized males. Uca capricornis are also capable of rapid colour changes in response to stress, but show no endogenous rhythms associated with the semilunar and tidal cycles commonly reported in other fiddler crabs. The extreme colour polymorphism and the relative stability of the colour patterns in Uca capricornis are consistent with their use in visually mediated mate recognition

    A Small RNA Controls Expression of the Chitinase ChiA in Listeria monocytogenes

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    In recent years, more than 60 small RNAs (sRNAs) have been identified in the gram-positive human pathogen Listeria monocytogenes, but their putative roles and mechanisms of action remain largely unknown. The sRNA LhrA was recently shown to be a post-transcriptional regulator of a single gene, lmo0850, which encodes a small protein of unknown function. LhrA controls the translation and degradation of the lmo0850 mRNA by an antisense mechanism, and it depends on the RNA chaperone Hfq for efficient binding to its target. In the present study, we sought to gain more insight into the functional role of LhrA in L. monocytogenes. To this end, we determined the effects of LhrA on global-wide gene expression. We observed that nearly 300 genes in L. monocytogenes are either positively or negatively affected by LhrA. Among these genes, we identified lmo0302 and chiA as direct targets of LhrA, thus establishing LhrA as a multiple target regulator. Lmo0302 encodes a hypothetical protein with no known function, whereas chiA encodes one of two chitinases present in L. monocytogenes. We show here that LhrA acts as a post-transcriptional regulator of lmo0302 and chiA by interfering with ribosome recruitment, and we provide evidence that both LhrA and Hfq act to down-regulate the expression of lmo0302 and chiA. Furthermore, in vitro binding experiments show that Hfq stimulates the base pairing of LhrA to chiA mRNA. Finally, we demonstrate that LhrA has a negative effect on the chitinolytic activity of L. monocytogenes. In marked contrast to this, we found that Hfq has a stimulating effect on the chitinolytic activity, suggesting that Hfq plays multiple roles in the complex regulatory pathways controlling the chitinases of L. monocytogenes

    Rationale, design and methods for a randomised and controlled trial to evaluate "Animal Fun" - a program designed to enhance physical and mental health in young children

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    Background: Children with poor motor ability have been found to engage less in physical activities than other children, and a lack of physical activity has been linked to problems such as obesity, lowered bone mineral density and cardiovascular risk factors. Furthermore, if children are confident with their fine and gross motor skills, they are more likely to engage in physical activities such as sports, crafts, dancing and other physical activity programs outside of the school curriculum which are important activities for psychosocial development. The primary objective of this project is to comprehensively evaluate a whole of class physical activity program called Animal Fun designed for Pre-Primary children. This program was designed to improve the child's movement skills, both fine and gross, and their perceptions of their movement ability, promote appropriate social skills and improve social-emotional development. Methods: The proposed randomized and controlled trial uses a multivariate nested cohort design to examine the physical (motor coordination) and psychosocial (self perceptions, anxiety, social competence) outcomes of the program. The Animal Fun program is a teacher delivered universal program incorporating animal actions to facilitate motor skill and social skill acquisition and practice. Pre-intervention scores on motor and psychosocial variables for six control schools and six intervention schools will be compared with post-intervention scores (end of Pre-Primary year) and scores taken 12 months later after the children's transition to primary school Year 1. 520 children aged 4.5 to 6 years will be recruited and it is anticipated that 360 children will be retained to the 1 year follow-up. There will be equal numbers of boys and girls.Discussion: If this program is found to improve the child's motor and psychosocial skills, this will assist in the child's transition into the first year of school. As a result of these changes, it is anticipated that children will have greater enjoyment participating in physical activities which will further promote long term physical and mental health

    Implications of the impact of prevalence on test thresholds and outcomes: lessons from tuberculosis

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    Abstract Background With today’s rapid advances in technology and understanding of disease, more screening and diagnostic tests have become available in a variety of sociodemographic and clinical settings. This analysis quantifies the impact of varying prevalence rates on test performance for given sensitivity and specificity values. Methods Using a worked example of latent tuberculosis infection, we compared true-positive (TP) and false-positive (FP) results when varying prevalence and test sensitivity and specificity. We used estimates from published literature to estimate two tests’ sensitivity (81%, QuantiFERON®-TB Gold In-Tube; 88%, T-SPOT®.TB) and specificity (99%; 88%), and we used World Health Organization data to estimate disease prevalence in five countries. Results Varying sensitivity impacted outcomes most in high-prevalence settings; change in specificity had greater impact in low-prevalence settings. In switching from QuantiFERON-TB to T-SPOT.TB (higher sensitivity, lower specificity), trade-offs between increasing case identification (TPs) and decreasing unnecessary treatments (FPs) varied dramatically with prevalence. Lower-prevalence settings paid a greater “price” of more FPs for each TP gained, with 37.7 FPs per TP in the United States (5% prevalence) versus 2.5 in the Ivory Coast (55% prevalence). Conclusions Prevalence affects test performance for given sensitivity and specificity values. To optimize test performance, disease prevalence should be incorporated in testing decisions, and sensitivity and specificity should be set locally, not globally. In lower-prevalence settings, using highly specific assays may optimize outcomes

    Costs associated with treatment of insomnia in Alzheimer's disease caregivers: a comparison of mindfulness meditation and cognitive behavioral therapy for insomnia.

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    BackgroundAmong the over 5 million informal caregivers for patients with Alzheimer's disease (AD) in the United States (US), over 60% experience insomnia. Research on insomnia treatment efficacy in AD caregivers is limited. An ongoing randomized non-inferiority clinical trial, the Caregiver Sleep Research study, is evaluating whether mindfulness meditation is non-inferior to cognitive behavioral therapy for insomnia (CBT-I) in the treatment of insomnia in AD caregivers. The present report examines estimated intervention costs in this ongoing trial.MethodsMicro-costing was used to itemize and abstract costs of the two interventions: a mindfulness-based intervention known as mindful awareness practices for insomnia (MAP-I); and CBT-I. This approach involves collecting detailed data on resources utilized and the unit costs of those resources, thereby revealing actual resource use and economic costs for each treatment arm. Personnel time, patient time, and supplies were inventoried, and unit costs were applied. Caregiver time costs, including travel, were based on US Labor Bureau home-health aide national mean hourly wages; instructor/staff costs were based on hourly wages. Per-participant and program costs were calculated assuming individual- and group-delivery to reflect real-world implementation. Sensitivity analyses evaluated robustness of estimates.ResultsFrom the societal perspective, per-participant MAP-I costs were 1884forindividualand1884 for individual and 1377 for group delivery; for CBT-I, these costs were 3978and3978 and 1981, respectively. Compared with CBT-I, MAP-I provided cost savings of 2094(532094 (53%) and 604 (30%) per treated caregiver for individual and group delivery, respectively. From the US healthcare system perspective, MAP-I vs. CBT-I participant savings were 1872(651872 (65%) for individual and 382 (44%) for group interventions, respectively. For MAP-I and CBT-I, instructor in-class time was the highest cost component. Results were most sensitive to combined instructor time costs.ConclusionsTreatment of insomnia with MAP-I, compared to CBT-I, yields substantial cost savings for society and the healthcare system. With this potential for cost savings, results of the ongoing non-inferiority trial have critical implications for insomnia treatment dissemination and its benefits to AD caregivers and other community populations with insomnia

    Effect of Onco type

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    “Up the Windsor Road” : social complexity, geographies of emotion, and the rise of Hillsong

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    This chapter explores the expansion of Hillsong in socio-historical terms, matching its responses to key challenges to contexts and trends in each of the following Hillsong 1.0–4.0 “identities”: as context driven local churchplant; as culture driven regional worship church; as personality-driven transnational network Church; and as brand-driven, technology-mediated Global Church. All these identities co-exist in various localities. The chapter plays particular attention to contextual factors such as Australian public secularism and crises of politics, corporatism and infrastructure, and the consequent development of geographies of emotion and aesthetics which help Hillsong “bridge” into global settings. It is a story not only of the ability of new evangelicalisms to renew and overplant old forms, but of remarkable internal resources of leadership and organization adaptability
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