1,347 research outputs found
The anti-adhesive effect of curcumin on Candida albicans biofilms on denture materials
The use of natural compounds as an alternative source of antimicrobials has become a necessity given the growing concern over global antimicrobial resistance. Polyphenols, found in various edible plants, offers one potential solution to this. We aimed to investigate the possibility of using curcumin within the context of oral health as a way of inhibiting and preventing the harmful development of Candida albicans biofilms. We undertook a series of adsorption experiments with varying concentrations of curcumin, showing that 50 ug/ml could prevent adhesion. This effect could be further synergised by the curcumin pretreatment of yeast cells to obtain significantly greater inhibition (>90, p<0.001). Investigation of the biological impact of curcumin showed that it preferentially affected immature morphological forms (yeast and germlings), and actively promoted aggregation of the cells. Transcriptional analyses showed that key adhesins were down-regulated (ALS1 and ALS3), whereas aggregation related genes (ALS5 and AAF1) were up-regulated. Collectively, these data demonstrated that curcumin elicits anti-adhesive effects and that induces transcription of genes integrally involved in the processes related to biofilm formation. Curcumin and associated polyphenols therefore have the capacity to be developed for use in oral healthcare to augment existing preventative strategies for candidal biofilms on the denture surface
Macrofaunal communities associated with chemosynthetic habitats from the US Atlantic margin: A comparison among depth and habitat types
Improving the efficiency of electrochemical CO2 reduction using immobilized manganese complexes
Immobilization of [Mn(bpy)(CO)3Br], (1) and [Mn(bpy(tBu)2)(CO)3Br] (2, where (bpy(tBu)2) = 4,4′-di-tert-butyl-2,2′-bipyridine) in Nafion/multi-walled carbon nanotubes (MWCNT) on glassy carbon yielded highly active electrodes for the reduction of CO2 to CO in aqueous solutions at pH 7. Films incorporating 2 have significantly improved selectivity towards CO2, with CO : H2 ∼ 1 at −1.4 V vs. SCE, exceeding that for the previously reported 1/MWCNT/Nafion electrode. Furthermore, we report the synthesis and subsequent electrochemical characterization of two new substituted Mn(i) bipyridine complexes, [Mn(bpy(COOH)2)(CO)3Br] (3) and [Mn(bpy(OH)2)(CO)3Br] (4) (where (bpy(COOH)2) = 4,4′-di-carboxy-2,2′-bipyridine and (bpy(OH)2) = 4,4′-di-hydroxy-2,2′-bipyridine). Both 3 and 4 were found to have some activity towards CO2 in acetonitrile solutions; however once immobilized in Nafion membranes CO2 reduction was found to not occur at significant levels.</p
African Food Security Fellows’ Perceptions of Their Experiences in the United States: Reflective Journaling as a Way to Interpret and Understand an International Experience
The study reports on a reciprocal exchange program funded by the U.S. Department of State. It involved 14 Food Security Fellows, including seven each from Kenya and Uganda, who were community leaders, policymakers, and media professionals. The Fellows experienced afive-week training program on issues of food securityand the unique role improved communication networks could play in reducing food insufficiency in their countries. During their exchange, the Fellows were asked to keep reflective journals chronicling their training experiences and interactions with Americans and their culture. The journal entries were transcribedandcoded, and emergent themeswere identified in concert with the study’s purpose and research questions. Established procedures to address researcher reflexivity and enabletransferability of the findings were followed. The data analysis yielded 41 codes from which 11 themeswere derived. The Fellows expressed a more positive attitude about Americans and the United States at the program’s end. They also described an appreciation for the role of youth development in agriculture and the need for extension educators,researchers, and university personnelto work together to ensure a nation’s food security. Future exchanges should provide participants with an internship experience instead of only job shadowing opportunitie
A systematic evaluation of physical activity and diet policies in Scotland : results from the 2021 Active Healthy Kids Report Card
Acknowledgements The authors are grateful to the stakeholders who appraised and provided feedback on the policy evaluation and grade (within the Report Card) prior to publication of the Report Card.Peer reviewe
Candida albicans biofilm heterogeneity does not influence denture stomatitis but strongly influences denture cleansing capacity
Approximately 20 % of the UK population wear some form of denture prosthesis, resulting in denture stomatitis in half of these individuals. Candida albicans is primarily attributed as the causative agent, due to its biofilm -forming ability. Recently, there has been increasing evidence of C. albicans biofilm heterogeneity and the negative impact it can have clinically; however, this phenomenon has yet to be studied in relation to denture isolates. The aims of this study were to evaluate C. albicans biofilm formation of clinical denture isolates in a denture environment and to assess antimicrobial activity of common denture cleansers against these tenacious communities. C. albicans isolated from dentures of healthy and diseased individuals was quantified using real-time PCR and biofilm biomass assessed using crystal violet. Biofilm development on the denture substratum poly(methyl methacrylate), Molloplast B and Ufi-gel was determined. Biofilm formation was assessed using metabolic and biomass stains, following treatment with denture hygiene products. Although C. albicans was detected in greater quantities in diseased individuals, it was not associated with increased biofilm biomass. Denture substrata were shown to influence biofilm biomass, with poly(methyl methacrylate) providing the most suitable environment for C. albicans to reside. Of all denture hygiene products tested, Milton had the most effective antimicrobial activity, reducing biofilm biomass and viability the greatest. Overall, our results highlight the complex nature of denture- related disease, and disease development cannot always be attributed to a sole cause. It is the distinct combination of various factors that ultimately determines the pathogenic outcome
The Role of Galactic Winds on Molecular Gas Emission from Galaxy Mergers
We assess the impact of starburst and AGN feedback-driven winds on the CO
emission from galaxy mergers, and, in particular, search for signatures of
these winds in the simulated CO morphologies and emission line profiles. We do
so by combining a 3D non-LTE molecular line radiative transfer code with
smoothed particle hydrodynamics (SPH) simulations of galaxy mergers that
include prescriptions for star formation, black hole growth, a multiphase
interstellar medium (ISM), and the winds associated with star formation and
black hole growth. Our main results are: (1) Galactic winds can drive outflows
of masses ~10^8-10^9 Msun which may be imaged via CO emission line mapping. (2)
AGN feedback-driven winds are able to drive imageable CO outflows for longer
periods of time than starburst-driven winds owing to the greater amount of
energy imparted to the ISM by AGN feedback compared to star formation. (3)
Galactic winds can control the spatial extent of the CO emission in post-merger
galaxies, and may serve as a physical motivation for the sub-kiloparsec scale
CO emission radii observed in local advanced mergers. (4) Secondary emission
peaks at velocities greater than the circular velocity are seen in the CO
emission lines in all models. In models with winds, these high velocity peaks
are seen to preferentially correspond to outflowing gas entrained in winds,
which is not the case in the model without winds. The high velocity peaks seen
in models without winds are typically confined to velocity offsets (from the
systemic) < 1.7 times the circular velocity, whereas the models with AGN
feedback-driven winds can drive high velocity peaks to ~2.5 times the circular
velocity.Comment: Accepted by ApJ; Minor revisions; Resolution tests include
Elementary School Staff Perspectives On the Implementation of Physical activity approaches in Practice: an Exploratory Sequential Mixed Methods Study
INTRODUCTION: A whole-of-school approach is best to promote physical activity before, during, and after school. However, multicomponent programming is often complex and difficult to deliver in school settings. There is a need to better understand how components of a whole-of-school approach are implemented in practice. The objectives of this mixed methods study were to: (1) qualitatively explore physical activity approaches and their implementation in elementary schools, (2) quantitatively assess implementation levels, and (3) examine associations between school-level physical activity promotion and academic ratings.
METHODS: We used an exploratory sequential mixed methods design. We conducted semi-structured qualitative interviews with elementary school staff from a Texas school district and used a directed content analysis to explore physical activity approaches and their implementation. Using qualitative findings, we designed a survey to quantitatively examine the implementation of physical activity approaches, which we distributed to elementary staff district wide. We used Pearson correlation coefficients to examine the association between the amount of physical activity opportunities present in individual schools and school-level academic ratings.
RESULTS: We completed 15 interviews (7 principals/assistant principals, 4 physical educators, and 4 classroom teachers). Elementary school teachers and staff indicated PE and recess implementation was driven from the top-down by state and district policies, while implementation of classroom-based approaches, before and after school programming, and active transport were largely driven from the bottom-up by teachers and school leaders. Teachers and staff also discussed implementation challenges across approaches. Survey respondents (
CONCLUSION: Schools provided physical activity opportunities consistent with a whole-of-school approach, although there was variability between schools and implementation challenges were present. Leveraging existing school assets while providing school-specific implementation strategies may be most beneficial for supporting successful physical activity promotion in elementary schools
Observed and Perceived Benefits of Providing Physical Activity Opportunities in Elementary Schools: A Qualitative Study
INTRODUCTION: Schools play an important role in promoting physical activity for youth. However, school-based physical activity opportunities often compete with other academic priorities, limiting their implementation. The purpose of this study was to qualitatively explore elementary school teacher and staff perspectives on providing physical activity opportunities and how they impact students and learning.
METHODS: We partnered with a school district in Texas to conduct semi-structured individual interviews. We used a purposeful sampling approach to recruit elementary teachers and staff knowledgeable about the physical activity opportunities provided at their school. Interviews included questions about participant opinions of providing physical activity opportunities and the types of opportunities provided. We analyzed data using a directed content analysis and iterative categorization approach.
RESULTS: Fifteen participants (4 teachers, 4 physical education teachers, 3 assistant principals, and 4 principals) completed interviews from 10 elementary schools. Participants discussed observed and perceived benefits when providing physical activity opportunities, which emerged into four themes and subthemes: (1) academic benefits (learning readiness, learning engagement, and academic performance); (2) social-emotional benefits (behavior, interpersonal and social skills, and classroom culture); (3) physical benefits (brain health, skill development, physical health); and (4) instructional benefits (quality teaching time, helpful teaching tools, and teacher-student relationships).
CONCLUSIONS: Teachers and staff observed numerous benefits when students had opportunities to be physically active, including the positive impact on academic and social-emotional outcomes. Our findings highlight the alignment of physical activity with other school priorities. Physical activity programming can be used in ways to support academics, learning, behavior, and other important outcomes
Regioselective cycloaddition of potassium alkynyltrifluoroborates with 3-azetidinones and 3-oxetanone by nickel-catalysed C-C bond activation
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