Effect of Caffeine on the Growth of Streptococcus mutans

poster abstractCaffeine consumption is a staple of the typical adult diet. Previous research has demonstrated many possible health benefits of regular consumption of caffeine-containing beverages such as coffee and tea. Coffee may contain up 200 mg caffeine/cup (84 μg/ml). This study investigated the correlation between oral health and caffeine consumption by observing the effects of the compound on the growth of a leading contributor to tooth decay, Streptococcus mutans. Assays were performed to examine the effect of different concentrations of caffeine on both the planktonic and biofilm growth of the bacteria. Caffeine concentrations of 200 and 400 μg/ml demonstrated significant biofilm formation enhancement (p<0.05). Contrastingly, concentrations from 31.25 through 100 μg/ml caused a slight, significant inhibition in biofilm formation. Planktonic growth of S. mutans was marginally inhibited in concentrations of 31.25 through 200 μg/ml. The results of this study indicate a potential for adverse side effects to oral health when caffeine is consumed in high concentrations. Lower concentrations such as those naturally found in coffee and tea may inhibit formation of biofilm and dental plaque, thereby promoting good oral health

Nicotine: Its Stimulating and Inhibitory Effects on Oral Microorganisms

Tobacco users are much more susceptible to dental caries and periodontal diseases than non-tobacco users. Research suggests that this increased susceptibility may be due in part to nicotine, a primary active component of tobacco. Five bacterial species and one yeast species commonly found in the human oral cavity, Lactobacillus casei, Actinomyces viscosus, Actinomyces naeslundii, Rothia dentocariosa, Enterococcus faecalis, and Candida albicans respectively, were utilized to investigate if any correlation existed between exposure to various concentrations of nicotine ranging from 0 to 32 mg/ml and the growth of each microorganism. The minimum inhibitory concentration (MIC), minimum biofilm inhibitory concentration (MBIC), and planktonic growth were measured. The MIC was determined to be 16 mg/ml for all organisms except E. faecalis, which had an MIC of 32 mg/ml. Nicotine had a varying effect on planktonic growth across the different species. A distinct upward trend in biofilm formation was found in A. viscosus, L. casei, E. faecalis, and C. albicans through 8 mg/ml. Nicotine also enhanced R. dentocariosa biofilm formation in all concentrations through 8 mg/ml but was most enhanced at 1 mg/ml. Alternatively, A. naeslundii exhibited a complete downward trend through 32 mg/ml. The MBIC was found to be 16 mg/ml in all organisms studied. These findings further support research suggesting that the increased susceptibility to oral health diseases experienced by tobacco users may be caused in part by an upregulation in biofilm formation of these oral pathogens

Nonassociative geometry in quasi-Hopf representation categories II: connections and curvature

We continue our systematic development of noncommutative and nonassociative differential geometry internal to the representation category of a quasitriangular quasi-Hopf algebra. We describe derivations, differential operators, differential calculi and connections using universal categorical constructions to capture algebraic properties such as Leibniz rules. Our main result is the construction of morphisms which provide prescriptions for lifting connections to tensor products and to internal homomorphisms. We describe the curvatures of connections within our formalism, and also the formulation of Einstein-Cartan geometry as a putative framework for a nonassociative theory of gravity

Early risk factors of overweight developmental trajectories during middle childhood

Background Research is needed to identify early life risk factors associated with different developmental paths leading to overweight by adolescence. Objectives To model heterogeneity in overweight development during middle childhood and identify factors associated with differing overweight trajectories. Methods Data was drawn from the Quebec Longitudinal Study of Child Development (QLSCD; 1998- 2010). Trained research assistants measured height and weight according to a standardized protocol and conducted yearly home interviews with the child’s caregiver (mother in 98% of cases). Information on several putative early life risk factors for the development of overweight were obtained, including factors related to the child’s perinatal, early behavioral family and social environment. Group-based trajectories of the probability of overweight (6- 12 years) were identified with a semiparametric method (n=1678). Logistic regression analyses were used to identify early risk factors (5 months- 5 years) associated with each trajectory. Results Three trajectories of overweight were identified: “early-onset overweight” (11.0 %), “lateonset overweight” (16.6%) and “never overweight” (72.5%). Multinomial analyses indicated that children in the early and late-onset group, compared to the never overweight group, had 3 common types of risk factors: parental overweight, preschool overweight history, and large size for gestational age. Maternal overprotection (OR= 1.12, CI: 1.01-1.25), short nighttime sleep duration (OR=1.66, CI: 1.07-2.57), and immigrant status (OR=2.01, CI: 1.05-3.84) were factors specific to the early-onset group. Finally, family food insufficiency (OR=1.81, CI: 1.00-3.28) was weakly associated with membership in the late-onset trajectory group. Conclusions The development of overweight in childhood follows two different trajectories, which have common and distinct risk factors that could be the target of early preventive interventions

An Experimental Comparison of Associative Responses to Two Types of Randomly Derived Stimuli

Two methods for constructing random shapes were compared as to their effect upon latency of the associative response. Attneave and Arnoult had hypothesized that their Method II shapes would contain less stimulus information than would their Method I shapes. In the present study this hypothesis was substantiated only for female subjects. It was concluded that a reduction in stimulus information could not alone account for these results and that subject variables such as set and response threshold variability, must be included in the interpretation of results

Gleam: the GLAST Large Area Telescope Simulation Framework

This paper presents the simulation of the GLAST high energy gamma-ray telescope. The simulation package, written in C++, is based on the Geant4 toolkit, and it is integrated into a general framework used to process events. A detailed simulation of the electronic signals inside Silicon detectors has been provided and it is used for the particle tracking, which is handled by a dedicated software. A unique repository for the geometrical description of the detector has been realized using the XML language and a C++ library to access this information has been designed and implemented.Comment: 10 pages, Late

Experiencing food insecurity in childhood: influences on eating habits and body weight in young adulthood

Abstract Objective: To examine how food insecurity in childhood up to adolescence relates to eating habits and weight status in young adulthood. Design: A longitudinal study design was used to derive trajectories of household food insecurity from age 4.5 to 13 years. Multivariable linear and logistical regression analyses were performed to model associations between being at high risk of food insecurity from age 4.5 to 13 years and both dietary and weight outcomes at age 22 years. Setting: A birth cohort study conducted in the Province of Quebec, Canada. Participants: 698 young adults participating in the Québec Longitudinal Study of Child Development. Results: After adjusting for sex, maternal education and immigrant status, household income and type of family, being at high risk (compared to low risk) of food insecurity in childhood up to adolescence was associated with consuming higher quantities of sugar-sweetened beverages (ßadj: 0.64; 95% CI: 0.27-1.00), non-whole-grain cereal products (ßadj: 0.32; 95% CI: 0.07-0.56), and processed meat (ßadj: 0.14; 95% CI: 0.02-0.25), with skipping breakfast (ORadj: 1.97; 95% CI: 1.08-3.53), with eating meals prepared out of home (ORadj: 3.38; 95% CI: 1.52-9.02), with experiencing food insecurity (ORadj: 3.03; 95% CI: 1.91-4.76), and with being obese (ORadj: 2.01; 95% CI: 1.12-3.64), once reaching young adulthood. Conclusion: Growing up in families experiencing food insecurity may negatively influence eating habits and weight status later in life. Our findings reinforce the importance of public-health policies and programs tackling poverty and food insecurity, particularly for families with young children

Parkinson's disease biomarkers: perspective from the NINDS Parkinson's Disease Biomarkers Program

Biomarkers for Parkinson's disease (PD) diagnosis, prognostication and clinical trial cohort selection are an urgent need. While many promising markers have been discovered through the National Institute of Neurological Disorders and Stroke Parkinson's Disease Biomarker Program (PDBP) and other mechanisms, no single PD marker or set of markers are ready for clinical use. Here we discuss the current state of biomarker discovery for platforms relevant to PDBP. We discuss the role of the PDBP in PD biomarker identification and present guidelines to facilitate their development. These guidelines include: harmonizing procedures for biofluid acquisition and clinical assessments, replication of the most promising biomarkers, support and encouragement of publications that report negative findings, longitudinal follow-up of current cohorts including the PDBP, testing of wearable technologies to capture readouts between study visits and development of recently diagnosed (de novo) cohorts to foster identification of the earliest markers of disease onset

Financing Direct Democracy: Revisiting the Research on Campaign Spending and Citizen Initiatives

The conventional view in the direct democracy literature is that spending against a measure is more effective than spending in favor of a measure, but the empirical results underlying this conclusion have been questioned by recent research. We argue that the conventional finding is driven by the endogenous nature of campaign spending: initiative proponents spend more when their ballot measure is likely to fail. We address this endogeneity by using an instrumental variables approach to analyze a comprehensive dataset of ballot propositions in California from 1976 to 2004. We find that both support and opposition spending on citizen initiatives have strong, statistically significant, and countervailing effects. We confirm this finding by looking at time series data from early polling on a subset of these measures. Both analyses show that spending in favor of citizen initiatives substantially increases their chances of passage, just as opposition spending decreases this likelihood

Randomized, Controlled Trial of the Long Term Safety, Immunogenicity and Efficacy of RTS,S/AS02(D) Malaria Vaccine in Infants Living in a Malaria-Endemic Region.

The RTS,S/AS malaria candidate vaccine is being developed with the intent to be delivered, if approved, through the Expanded Programme on Immunization (EPI) of the World Health Organization. Safety, immunogenicity and efficacy of the RTS,S/AS02(D) vaccine candidate when integrated into a standard EPI schedule for infants have been reported over a nine-month surveillance period. This paper describes results following 20 months of follow up. This Phase IIb, single-centre, randomized controlled trial enrolled 340 infants in Tanzania to receive three doses of RTS,S/AS02(D) or hepatitis B vaccine at 8, 12, and 16 weeks of age. All infants also received DTPw/Hib (diphtheria and tetanus toxoids, whole-cell pertussis vaccine, conjugated Haemophilus influenzae type b vaccine) at the same timepoints. The study was double-blinded to month 9 and single-blinded from months 9 to 20. From month 0 to 20, at least one SAE was reported in 57/170 infants who received RTS,S/AS02(D) (33.5%; 95% confidence interval [CI]: 26.5, 41.2) and 62/170 infants who received hepatitis B vaccine (36.5%; 95% CI: 29.2, 44.2). The SAE profile was similar in both vaccine groups; none were considered to be related to vaccination. At month 20, 18 months after completion of vaccination, 71.8% of recipients of RTS,S/AS02(D) and 3.8% of recipients of hepatitis B vaccine had seropositive titres for anti-CS antibodies; seroprotective levels of anti-HBs antibodies remained in 100% of recipients of RTS,S/AS02(D) and 97.7% recipients of hepatitis B vaccine. Anti-HBs antibody GMTs were higher in the RTS,S/AS02(D) group at all post-vaccination time points compared to control. According to protocol population, vaccine efficacy against multiple episodes of malaria disease was 50.7% (95% CI: -6.5 to 77.1, p = 0.072) and 26.7% (95% CI: -33.1 to 59.6, p = 0.307) over 12 and 18 months post vaccination, respectively. In the Intention to Treat population, over the 20-month follow up, vaccine efficacy against multiple episodes of malaria disease was 14.4% (95% CI: -41.9 to 48.4, p = 0.545). The acceptable safety profile and good tolerability of RTS,S/AS02(D) in combination with EPI vaccines previously reported from month 0 to 9 was confirmed over a 20 month surveillance period in this infant population. Antibodies against both CS and HBsAg in the RTS,S/AS02(D) group remained significantly higher compared to control for the study duration. Over 18 months follow up, RTS,S/AS02(D) prevented approximately a quarter of malaria cases in the study population. CLINICAL TRIALS: Gov identifier: NCT00289185