369 research outputs found
BDNF Val66Met and 5-HTTLPR genotype are each associated with visual scanning patterns of faces in young children
Previous studies have documented both neuroplasticity-related BDNF Val66Met and emotion regulation-related 5-HTTLPR polymorphisms as genetic variants that contribute to the processing of emotions from faces. More specifically, research has shown the BDNF Met allele and the 5-HTTLPR Short allele to be associated with mechanisms of negative affectivity that relate to susceptibility for psychopathology. We examined visual scanning pathways in response to angry, happy, and neutral faces in relation to BDNF Val66Met and 5-HTTLPR genotyping in 49 children aged 4- to 7-years. Analyses revealed that variations in the visual processing of facial expressions of anger interacted with BDNF Val66Met genotype, such that children who carried at least one low neuroplasticity Met allele exhibited a vigilance-avoidance pattern of visual scanning compared to homozygotes for the high neuroplasticity Val allele. In a separate investigation of eye gaze towards the eye versus mouth regions of neutral faces, we observed that short allele 5-HTTLPR carriers exhibited reduced looking at the eye region compared with those with the higher serotonin uptake Long allele. Together, these findings suggest that genetic mechanisms early in life may influence the establishment of patterns of visual scanning of environmental stressors, which in conjunction with other factors such as negative life events may lead to psychological difficulties and disorders in the later adolescent and adult years
Applicability of the Filter Paper Technique for Detection of Antifilarial IgG4 Antibodies Using the Bm14 Filariasis CELISA
Demonstration of successful elimination of lymphatic filariasis (LF) in endemic countries requires sensitive diagnostics for accurate definitions of endpoints and future surveillance. There has been interest in complementing available diagnostics with antibody serology testing in children, since negative serology would correspond with cessation of LF transmission. The Filariasis CELISA detects antifilarial IgG4 and has favourable results with serum samples but field application requires an easier sampling method. Ninety-four paired plasma and filter paper samples were assayed with promising results. The filter paper method resulted in a sensitivity of 92% and a specificity of 77% when compared to the paired plasma. One hundred and one filter paper samples were assessed for storage effects. Following 10-month storage at −20°C there was a significant reduction in reactivity (P < .001). Overall the results indicated that filter paper sampling would be a favourable sensitive and specific alternative for blood collection in surveys
Applicability of the Filter Paper Technique for Detection of Antifilarial IgG4 Antibodies Using the Bm14 Filariasis CELISA
Demonstration of successful elimination of lymphatic filariasis (LF) in endemic countries requires sensitive diagnostics for accurate definitions of endpoints and future surveillance. There has been interest in complementing available diagnostics with antibody serology testing in children, since negative serology would correspond with cessation of LF transmission. The Filariasis CELISA detects antifilarial IgG4 and has favourable results with serum samples but field application requires an easier sampling method. Ninety-four paired plasma and filter paper samples were assayed with promising results. The filter paper method resulted in a sensitivity of 92% and a specificity of 77% when compared to the paired plasma. One hundred and one filter paper samples were assessed for storage effects. Following 10-month storage at −20°C there was a significant reduction in reactivity (P < .001). Overall the results indicated that filter paper sampling would be a favourable sensitive and specific alternative for blood collection in surveys
Applicability of the filter paper technique for detection of antifilarial IgG4 antibodies using the Bm14 filariasis CELISA
Demonstration of successful elimination of lymphatic filariasis (LF) in endemic countries requires sensitive diagnostics for accurate definitions of endpoints and future surveillance. There has been interest in complementing available diagnostics with antibody serology testing in children, since negative serology would correspond with cessation of LF transmission. The Filariasis CELISA detects antifilarial IgG4 and has favourable results with serum samples but field application requires an easier sampling method. Ninety-four paired plasma and filter paper samples were assayed with promising results. The filter paper method resulted in a sensitivity of 92% and a specificity of 77% when compared to the paired plasma. One hundred and one filter paper samples were assessed for storage effects. Following 10-month storage at −20°C there was a significant reduction in reactivity (P<.001). Overall the results indicated that filter paper sampling would be a favourable sensitive and specific alternative for blood collection in surveys
Early suppression of B cell immune responses by low doses of chloroquine and pyrimethamine: implications for studying immunity in malaria
Malaria remains a significant worldwide public health problem. To address biological questions, researchers rely on the experimental murine model. For decades, chloroquine (CQ) and pyrimethamine (Pyr) have been used to clear Plasmodium infections in experimental animals using standardised accepted protocols and, because of this, drug-treated controls are rarely included. However, there is limited data available on the modulation of anti-malarial immunity, including generation of memory B cells, when these drugs are administered days after malaria infection. We investigated B cell responses to an important malaria glycolipid, glycosylphosphatidylinositol (GPI), and the hapten nitrophenol (NP), with or without standard CQ and Pyr treatment using the murine model. At day 14, CQ/Pyr treatment significantly suppressed the frequency of NP⁺IgG1⁺ memory B cells in NP-KLH-immunised mice. Furthermore, CQ/Pyr-treated NP-KLH-immunised mice did not have significantly higher cellular counts of NP⁺ B cells, germinal centre B cells, nor NP⁺IgG1⁺ memory B cells than naïve mice (CQ/Pyr treated and untreated). CQ/Pyr-treated GPI-KLH-immunised mice did not have significantly higher cellular counts of GPI⁺ B cells than naïve untreated mice. By day 28, this effect appeared to resolve since all immunised mice, whether treated or untreated, had significantly higher B cell proliferative responses than naïve mice (CQ/Pyr treated and untreated) for the majority of B cell phenotypes. The current study emphasises the potential for drug modulation of antigenic B cell responses when using standardised malaria treatment protocols in the experimental murine model. It is recommended that drug-treated controls are included when using experimental malaria infections to address biological questions
Visual preference for social stimuli in individuals with autism or neurodevelopmental disorders : an eye-tracking study
Background
Recent research has identified differences in relative attention to competing social versus non-social video stimuli in individuals with autism spectrum disorder (ASD). Whether attentional allocation is influenced by the potential threat of stimuli has yet to be investigated. This is manipulated in the current study by the extent to which the stimuli are moving towards or moving past the viewer. Furthermore, little is known about whether such differences exist across other neurodevelopmental disorders. This study aims to determine if adolescents with ASD demonstrate differences in attentional allocation to competing pairs of social and non-social video stimuli, where the actor or object either moves towards or moves past the viewer, in comparison to individuals without ASD, and to determine if individuals with three genetic syndromes associated with differing social phenotypes demonstrate differences in attentional allocation to the same stimuli.
Methods
In study 1, adolescents with ASD and control participants were presented with social and non-social video stimuli in two formats (moving towards or moving past the viewer) whilst their eye movements were recorded. This paradigm was then employed with groups of individuals with fragile X, Cornelia de Lange, and Rubinstein-Taybi syndromes who were matched with one another on chronological age, global adaptive behaviour, and verbal adaptive behaviour (study 2).
Results
Adolescents with ASD demonstrated reduced looking-time to social versus non-social videos only when stimuli were moving towards them. Individuals in the three genetic syndrome groups showed similar looking-time but differences in fixation latency for social stimuli moving towards them. Across both studies, we observed within- and between-group differences in attention to social stimuli that were moving towards versus moving past the viewer.
Conclusions
Taken together, these results provide strong evidence to suggest differential visual attention to competing social versus non-social video stimuli in populations with clinically relevant, genetically mediated differences in socio-behavioural phenotypes
Reaching for the Cap and Gown: Progress Toward Success Boston's College Completion Goals for Graduates of the Boston Public Schools
A new report, prepared for Mayor Martin J. Walsh and the Success Boston college completion initiative, shows a remarkable increase in both the percentage and the number of Boston Public Schools graduates who complete college within six years. The report also examines college completion for students with Success Boston coaches, a major intervention launched by the Boston Foundation and its partners, including the Boston Public Schools, in 2009. Success Boston, a citywide multi-sector college completion initiative, was launched in 2008 in response to a report that found that only 35% of the BPS Class of 2000 graduates who enrolled in college earned a degree within seven years of graduating high school. The initiative is guided by the Boston Public Schools, the Boston Foundation, UMass Boston, Bunker Hill Community College, and the Boston Private Industry Council, along with dozens of colleges, universities, and nonprofit organizations. Among the initiative's ambitious goals was pushing members of the BPS Class of 2009 to a 52%six-year college completion rate. Today's report, "Reaching for the Cap and Gown: Progress Toward Success Boston's College Completion Goals for Graduates of the Boston Public Schools," finds that the six-year college completion rate of first-year college enrollees from the BPS Class of 2009 was 51.3%--within one percentage point of the 52% goal set in 2008. Equally impressive is the gain in the number of BPS graduates completing college within six years of high school graduation--1,314 from the Class of 2009, compared to 735 from the Class of 2000, the equivalent of a 79% increase. The study also finds that college completion, at 54.7%, is even higher than the goal for students who enrolled in the fall immediately after graduating from high school
Population genetic structure of the European lobster (Homarus gammarus) in the Irish Sea and implications for the effectiveness of the first British marine protected area
Levels of self-recruitment within and connectivity among populations are key factors influencing marine population persistence and stock sustainability, as well as the effectiveness of spatially explicit management strategies such as Marine Protected Areas (MPAs). In the United Kingdom (UK), Lundy Island in the Bristol Channel was designated a No-Take Zone (NTZ) in 2003 and became the UK’s first Marine Conservation Zone (MCZ) in 2009. This NTZ is expected to represent an additional resource for the sustainable management of the European lobster (Homarus gammarus) fishery. As the first step in a genetic monitoring program, this study aimed to investigate population genetic structure of lobster within and between the Irish Sea and Bristol Channel and in doing so to assess the functioning of the Lundy NTZ in the context of connectivity and other genetic parameters. Analysis of microsatellite data indicated that lobsters within the study area are genetically homogeneous and supports the view of a single panmictic population wherein the Lundy NTZ is highly connected. Levels of genetic variability were universally high with no evidence of differences for the NTZ. Furthermore, there was no evidence of recent genetic bottlenecks, and estimates of effective population sizes were infinitely large. The results suggest that if current management and breeding stock sizes are maintained genetic drift will not be strong enough to reduce neutral genetic diversity
Vaccine-induced carbohydrate-specific memory B cells reactivate during rodent malaria infection
A long-standing challenge in malaria is the limited understanding of B cell immunity, previously hampered by lack of tools to phenotype rare antigen-specific cells. Our aim was to develop a method for identifying carbohydrate-specific B cells within lymphocyte populations and to determine whether a candidate vaccine generated functional memory B cells (MBCs) that reactivated upon challenge with Plasmodium (pRBCs). To this end, a new flow cytometric probe was validated and used to determine the kinetics of B cell activation against the candidate vaccine glycosylphosphatidylinositol conjugated to Keyhole Limpet Haemocyanin (GPI-KLH). Additionally, immunized C57BL/6 mice were rested (10 weeks) and challenged with pRBCs or GPI-KLH to assess memory B cell recall against foreign antigen. We found that GPI-specific B cells were detectable in GPI-KLH vaccinated mice, but not in Plasmodium-infected mice. Additionally, in previously vaccinated mice GPI-specific IgG1 MBCs were reactivated against both pRBCs and synthetic GPI-KLH, which resulted in increased serum levels of anti-GPI IgG in both challenge approaches. Collectively our findings contribute to the understanding of B cell immunity in malaria and have important clinical implications for inclusion of carbohydrate conjugates in malaria vaccines
Laboratory Scale Testing of Ignition Overpressure for Space Vehicle Launch Pad Environments
A scale model of a NASA representative space vehicle is used to develop a refined estimate of the transient pressure loads that are expected to form at the base of the vehicle in the event of a vapor cloud explosion. Flammable vapor clouds are known to form prior to engine startup due to the significant amount of unburned hydrogen that is ejected from the combustion chamber. In the event of a vapor cloud explosion, the vehicle and payload must be able to withstand the resulting overpressure waves. The study comprises an array of pressure sensors located along the base heat shield of the scale model space vehicle as well as the interior wall and throat plug plane of the solid rocket booster. A spark source generator is used to simulate the overpressure wave produced by a vapor cloud explosion while measurements are acquired with and without the effect of a mobile launcher. Time- resolved schlieren images of the simulated vapor cloud explosion reveal the path and impact of both the initial wave and several reflected waves on the various components at the base of the space vehicle. In some instances, the reflected waves superpose to create waves that are higher in amplitude than the initial overpressure wave. A time frequency analysis of the pressure waveforms measured inside the solid rocket booster reveal a ring down tone corresponding to a standing wave that is four times the length of the nozzle
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