25 research outputs found
The Interrelationship between Insulin-Like Growth Factor 1, Apolipoprotein E ε4, Lifestyle Factors, and the Aging Body and Brain
Aging is associated with a decrease in body and brain function
and with a decline in insulin-like growth factor 1 levels. The
observed associations between alterations in insulin-like growth
factor 1 levels and cognitive functioning and Mild Cognitive
Impairment suggest that altered insulin-like growth factor 1
signaling may accompany Alzheimer’s disease or is involved
in the pathogenesis of the disease. Recent animal research
has suggested a possible association between insulin-like
growth factor 1 levels and the Apolipoprotein E ε4 allele, a
genetic predisposition to Alzheimer’s disease. It is therefore
hypothesized that a reduction in insulin-like growth factor
1 signaling may moderate the vulnerability to Alzheimer’s
disease of human Apolipoprotein E ε4 carriers. We address
the impact of age-related decline of insulin-like growth factor
1 levels on physical and brain function in healthy aging and
Alzheimer’s disease and discuss the links between insulin-like
growth factor 1 and the Apolipoprotein E ε4 polymorphism.
Furthermore, we discuss lifestyle interventions that may
increase insulin-like growth factor 1 serum levels, including
physical activity and adherence to a protein rich diet and
the possible benefits to the physical fitness and cognitive
functioning of the aging population
Revisiting the role of insulin-like growth factor-I receptor stimulating activity and the apolipoprotein E in Alzheimer's disease
__Background:__ Alterations in insulin-like growth factor I (IGF-I) signaling have been associated with dementia and Alzheimer's disease (AD). Studies on the association between IGF-I levels and dementia risk have been inconclusive. We reported earlier that higher levels of IGF-I receptor stimulating activity are associated with a higher prevalence and incidence of dementia.
__Objective:__ In the present study, we test the robustness of the association between IGF-I receptor stimulating activity and dementia by extending the follow-up period to 16 years and investigate possible effect modification by apolipoprotein E (ApoE).
__Methods:__ At baseline, circulating IGF-I receptor stimulating activity was determined by the IGF-I kinase receptor activation (KIRA) assay in 1,014 elderly from the Rotterdam Study. Dementia was assessed from baseline (1997-1999) to follow-up in January 2015. Associations of IGF-I receptor stimulating activity and incident dementia were assessed with Cox proportional hazards models.
__Results:__ During 10,752 person-years of follow-up, 174 people developed dementia. In the extended follow-up we no longer observed a dose-response relationship between IGF-I receptor stimulating activity and risk of dementia [adjusted odd
Environmental pressure from the 2014–15 eruption of Bárðarbunga volcano, Iceland
The effusive six months long 2014-2015 Bárðarbunga eruption (31 August-27 February) was the largest in Iceland for more than 200 years, producing 1.6 ± 0.3 km3 of lava. The total SO2 emission was 11 ± 5 Mt, more than the amount emitted from Europe in 2011. The ground level concentration of SO2 exceeded the 350 μg m−3 hourly average health limit over much of Iceland for days to weeks. Anomalously high SO2 concentrations were also measured at several locations in Europe in September. The lowest pH of fresh snowmelt at the eruption site was 3.3, and 3.2 in precipitation 105 km away from the source. Elevated dissolved H2SO4, HCl, HF, and metal concentrations were measured in snow and precipitation. Environmental pressures from the eruption and impacts on populated areas were reduced by its remoteness, timing, and the weather. The anticipated primary environmental pressure is on the surface
waters, soils, and vegetation of Iceland
Autism and ADHD – two ends of the same spectrum?
Abstract. Analysis of dynamics of biologically motivated neural networks allows for studying non-linear processes responsible for cognitive functions and thus provides adequate language to understand complex mental processes, including psychiatric syndromes and disorders. Problems with attention shifts that are at the roots of Autism Spectrum Disorders (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD), have been investigated using network model of Posner Visual Orienting Task (PVOT). Changing parameters that control biophysical properties of model neurons and cause network dysfunctions provides plausible explanations of many strange ASD and ADHD phenomena
Soil measurements during HAPEX-Sahel intensive observation period.
This article describes measurements made at each site and for each vegetation cover as part of the soils program for the HAPEX-Sahel regional scale experiment. The measurements were based on an initial sampling scheme and included profile soil water content, surface soil water content, soil water potential, infiltration rates, additional measurements on core samples, and grain size analysis. The measurements were used to categorize the state of the surface and profile soil water regimes during the experiment and to derive functional relationships for the soil water characteristic curve, unsaturated hydraulic conductivity function, and infiltration function. Sample results for different supersites and different vegetation covers are presented showing soil water profiles and total soil water storage on days corresponding to the experimental 'Golden Days'. Sample results are also presented for spatial and temporal distribution of surface moisture content and infiltration tests. The results demonstrate that the major experimental objective of monitoring the supersites during the most rapid vegetative growth stage with the largest change of the surface energy balance following the rainy season was very nearly achieved. Separation of the effects of probable root activity and drainage of the soil profile is possible. The potential for localized advection between the bare soil and vegetation strips of the tiger bush sites is demonstrated