Mathematical modeling of the radial profile of basilar membrane vibrations in the inner ear

Motivated by recent experimental results we seek an explanation of asymmetry in the radial profile of basilar membrane vibrations in the inner ear. We study a sequence of one-dimensional beam models which take into account variations in the bending stiffness of the basilar membrane as well as the potential presence of structural hinges. Our results suggest that the main cause of asymmetry is likely to be differences between the boundary conditions at the two extremes of the basilar membrane's width. This has fundamental implications for more detailed numerical simulations of the entire cochle

High-intensity intermittent exercise: effect on young people’s cardiometabolic health and cognition

With only a quarter of young people currently meeting physical activity guidelines, two key areas of concern are the effects of exercise on cardio-metabolic health and cognition. Despite the fact that physical activity in young people is typically high intensity and intermittent in nature; much of the literature examines traditional endurance type exercise. This review provides an update on the effects of high intensity intermittent exercise on young people’s cardio-metabolic health and cognition. High intensity intermittent exercise has acute beneficial effects on endothelial function and postprandial lipemia and chronic positive effects on weight management. In addition, there is emerging evidence regarding chronic benefits on blood lipid profile, blood pressure and pro- and anti-inflammatory cytokines. Furthermore, emerging evidence suggests beneficial acute and chronic effects of high intensity intermittent exercise on cognition. However, further research is required in both cardio-metabolic health and cognition, particularly regarding the impact of school-based interventions in adolescents

Breakfast consumption and cognitive function in adolescent school children

This study examined the effects of breakfast consumption on cognitive function, mood and blood glucose concentration in adolescent schoolchildren. With the institution's ethical advisory committee approval, 96 adolescents (12 to 15 years old) completed two randomly assigned trials (one following breakfast consumption and one following breakfast omission), scheduled 7 days apart. Cognitive function tests (visual search test, Stroop test and Sternberg paradigm), a mood questionnaire and a finger prick blood sample (in a subgroup of 60 participants) were completed immediately following breakfast and 120 min after the baseline measures. Following breakfast consumption, accuracy on the more complex level of the visual search test was higher than following breakfast omission (p=0.021). Similarly, accuracy on the Stroop test was better maintained across the morning following breakfast consumption when compared to breakfast omission (p=0.022). Furthermore, responses on the Sternberg paradigm were quicker later in the morning following breakfast consumption, particularly on the more complex levels (p=0.012). Breakfast consumption also produced higher self-report energy and fullness, lower self-report tiredness and hunger and higher blood glucose concentrations (all p<0.0005). Overall, the findings of the present study suggest that breakfast consumption enhances cognitive function in an adolescent population when compared to breakfast omission

Effect of urban vs. rural residence on the association between atopy and wheeze in Latin America: findings from a case-control analysis.

BACKGROUND: The association between atopy and asthma is attenuated in non-affluent populations, an effect that may be explained by childhood infections such as geohelminths. OBJECTIVE: To investigate the association between atopy and wheeze in schoolchildren living in urban and rural areas of Ecuador and examine the effects of geohelminths on this association. METHODS: We performed nested case-control studies among comparable populations of schoolchildren living in rural communities and urban neighbourhoods in the Province of Esmeraldas, Ecuador. We detected geohelminths in stool samples, measured recent wheeze and environmental exposures by parental questionnaire, and atopy by specific IgE (sIgE) and skin prick test (SPT) reactivity to aeroallergens. RESULTS: Atopy, particularly sIgE to house dust mite (HDM), was more strongly associated with recent wheeze in urban than rural schoolchildren: (urban, adj. OR 5.19, 95% CI 3.37-8.00, P < 0.0001; rural, adj. OR 1.81, 95%CI 1.09-2.99, P = 0.02; interaction, P < 0.001). The population fractions of wheeze attributable to atopy were approximately two-fold greater in urban schoolchildren: SPT to any allergen (urban 23.5% vs. rural 10.1%), SPT to HDM (urban 18.5% vs. rural 9.6%), and anti-HDM IgE (urban 26.5% vs. rural 10.5%), while anti-Ascaris IgE was related to wheeze in a high proportion of rural (49.7%) and urban (35.4%) children. The association between atopy and recent wheeze was attenuated by markers of geohelminth infections. CONCLUSIONS: Our data suggest that urban residence modifies the association between HDM atopy and recent wheeze, and this effect is explained partly by geohelminth infections

Soil-transmitted helminth parasites and allergy: Observations from Ecuador.

There is considerable interest as to potential protective effects of soil-transmitted helminths (STH) against allergy and allergic diseases. Here, we discuss findings of studies done of the effects of STH parasites on atopy and allergic diseases in Ecuador. While cross-sectional studies have consistently shown a reduced prevalence of allergen skin prick test (SPT) reactivity among infected schoolchildren, the removal of these infections by repeated deworming did not affect SPT prevalence over the short-term (ie, 12 months) but may have increased SPT prevalence over the long-term (ie, 15-17 years). In the case of allergic symptoms, cross-sectional studies have generally not shown associations with STH and intervention studies showed no impact on prevalence. However, a birth cohort suggested that early STH infections might reduce wheeze by 5 years. Allergic sensitization to Ascaris, however, explained a significant proportion of wheezing among rural schoolchildren. Studies of the effects of STH on immune and inflammatory responses indicated a potential role of STH in contributing to more robust regulation. The effects of STH on allergy are likely to be determined by history of exposure over the life-course and by interactions with a wide variety of other infectious and non-infectious factors

Functional porous composites by blending with solution-processable molecular pores

Porous scrambled cages can be homogenously blended with both functional molecules and non-porous polymers to form functional porous composites materials.</p

The effects of a mid-morning bout of exercise on adolescents' cognitive function

The aim of the present study was to examine the effects of a mid-morning bout of exercise on adolescents’ cognitive function in a randomised crossover design where each participant completed two experimental trials. Forty-five adolescents (13.3±0.3 years old), undertook a bout of exercise (ten repeats of level one of the multi-stage fitness test, 30s rest between repeats; exercise trial) or continued to rest (resting trial). A battery of cognitive function tests assessing visuo-motor speed, executive function and working memory (visual search test, Stroop test and Sternberg paradigm, respectively) was completed 30 min before and 45 min following the exercise. Average heart rate during exercise was 172±17 beats/min. On the visual search test, there was a greater improvement in response times across the morning on the exercise trial (t=2.6, p=0.009). However, this improvement in response times was combined with a greater decrease in accuracy on the exercise trial (z=2.0, p=0.044). On the Sternberg paradigm there was a greater improvement in response times across the morning following exercise when compared to resting (t=2.6, p=0.010). The mid-morning bout of exercise did not affect Stroop test performance. These improvements in response times are most likely the result of a general speeding up of responses across several cognitive domains, because response times were improved similarly across two different domains and across all test complexity levels, rather than being restricted to the specific high cognitive load levels. Accordingly, exercise in school settings may help to improve cognitive function in adolescents during the school morning