Processing Load and Biopotentials: An Evaluation of a Consumer Electroencephalogram (EEG)

The general public is extremely interested in mental training and the use of brain imaging to study the mind. One device that combines the two and is currently on the market for consumers is a single channel EEG band produced by NeuroSky which claims to measure concentration. However, the claim that they have developed a single channel measure of concentration and meditation have not been tested. EEG power is related to cognitive memory and performance, which both contribute to concentration. In addition to EEG waves, pupil size is a reliable physiological index of processing load and concentration. The first purpose of this study is to replicate the finding of pupil diameter size and concentration. The second purpose is to see if the results of the replication correlate with the proprietary concentration reading from the NeuroSky single channel EEG as a first step towards understanding what, if anything, consumer EEG equipment measures. In this study we found that pupil diameter can measure concentration and that a single channel consumer EEG device is also sensitive to concentration

Developing a Model to Explain the Process of Aging with Adult-Onset Physical Disability

People aging with adult-onset physical disabilities are a group who have been ; overlooked in the recent aging boom. Their needs differ greatly from the able-bodied population and understanding their perceptions may help to better inform policy and practice agendas. This constructivist grounded theory study used focus groups and interviews with participants. Concepts identified were said to be factors influencing the perceptions of people aging with disability. These factors included the entanglement of aging and disability, the multiplicity of experiences, financial resources, attitude and self-efficacy, and family and social support. These factors were used to create the Model of Aging with Disability (MAWD), a model that explains the process of both aging and disability together. Unlike the mainstream hypotheses and one set of models that look at aging with disability, this model is balanced in that it captures a range of experiences including positive, negative, and neutral ones

An Analysis of Mothers and Fathers Who Kill Their Children: Examining Offense Characteristics and Adjudication Outcomes

Filicide is a crime that conflicts with nature in that it undermines our genetic fitness and parental investment and defies attachment theory. Yet, despite the crime of filicide being counterintuitive, the media frequently reports on cases involving parents who have killed their own child. This analysis involves examining open-source cases of 100 mothers and 100 fathers who have killed their children. Analyses will compare the differences between mothers and fathers in terms of offender and victim demographics, as well as mental health and criminal histories. Offense characteristics and adjudication outcomes will also be examined.https://scholarworks.waldenu.edu/symposium2019/1003/thumbnail.jp

The role of environment, sink capacity, and carbon translocation in determining C3 plant responses to elevated [CO2]

Over the past century, CO2 concentration ([CO2]) in the atmosphere has been steadily increasing, leading to global climate change. Elevated [CO2] increases yield, biomass, and photosynthesis in most C3 plants, but the degree to which elevated [CO2] stimulates crop yields can depend upon climatic factors and plant physiological attributes, including sink strength and sugar transport capacity. This thesis uses field, laboratory, and meta-analytic techniques to investigate factors that influence the responsiveness of plants to elevated [CO2], with the ultimate aim of understanding variation in and improving future crop production. Photosynthesis is typically stimulated in C3 crops exposed to elevated [CO2], while stomatal conductance is typically decreased. Theory predicts that the magnitude of stimulation of photosynthesis at elevated [CO2] is greater at higher temperatures. In Chapter 2, the degree to which these physiological responses of C3 crops to elevated [CO2] would translate to yield responses was tested. Using a global dataset of published yield data from Free Air CO2 Enrichment (FACE) and Open Top Chamber (OTC) experiments, there was greater yield response to elevated [CO2] in C3 crops under dryer conditions, but there was no correlation between yield response to elevated [CO2] and growing season temperature. Thus, the theoretical response of photosynthesis to elevated [CO2] and temperature was not observed in seed yield, perhaps due to direct effects of temperature on respiration or reproductive processes. In Chapter 3, intraspecific variation in soybean (Glycine max) response to elevated [CO2] and the agronomic traits associated with greater yield responsiveness to elevated [CO2] were analyzed. Eighteen soybean cultivars, varying in maturity group, year of release date, and agronomic traits, were grown at SoyFACE from 2003 to 2008. There was significant intraspecific variation in yield response to elevated [CO2], with shorter cultivars and those with high harvest index showing greater response to elevated [CO¬2]. Harvest index is an indicator of sink strength, which may be important for CO2 response, because it can relieve the accumulation of carbohydrates in the photosynthesizing leaves, which at high concentrations in elevated [CO2] can signal down-regulation of photosynthetic capacity. In Chapter 4, the hypothesis that different mechanisms of phloem loading can lead to a change in the photosynthetic response to elevated [CO2] was tested. Plants have evolved different strategies to load phloem with sugars to send to sink tissue. One method, apoplastic loading, uses active sugar transporters to load phloem, while another method, symplastic loading, uses passive diffusion along a sucrose gradient from leaf mesophyll cells to phloem. The hypothesis was that passive loaders, adapted to high mesophyll sucrose concentrations, would experience less sugar-mediated feedback of photosynthesis at elevated [CO2] compared to apoplastic loaders. To test this, Pisum sativum (pea) and Beta vulgaris (beet; apoplastic phloem loaders) and Fragaria x ananassa (strawberry) and Paeonia lactiflora (peony; passive phloem loaders) were grown at elevated [CO2] in the field in 2013 and 2014, testing their biochemical, photosynthetic, and growth responses. All species responded to elevated [CO2] with increased photosynthesis and little down-regulation of capacity. There was a strong stimulation in leaf starch but little increase in leaf soluble sugar content at elevated [CO2], suggesting little sugar mediated downregulation of photosynthesis in any species. Thus, phloem loading strategy does not appear to be a strong determinant of plant response to elevated [CO2]. In Chapter 5, the impact of phloem loading on response to elevated [CO2] was studied further in two transgenic lines of Arabidopsis thaliana with altered sucrose transporter expression. In the HvSUT1 genotype, the primary sucrose transporter used for phloem loading in Arabidopsis (AtSUC2), was replaced with a barley sucrose transporter (HvSUT1), driven by the native AtSUC2 promoter since in vitro, HvSUT1 is more active than AtSUC2. In the AtSUC1 genotype, AtSUC1 was overexpressed in a wild-type background using the viral companion cell-specific promoter CoYMV to increase sucrose transporter expression. Neither transgenic line showed improved growth at ambient or elevated [CO2] compared to wild-type. The AtSUC1 genotype had a much greater response to elevated [CO2] than the other two genotypes, but only because growth at ambient [CO2] was significantly reduced. The reasons for stunted growth at ambient [CO2] in AtSUC1 are not clear, but do not appear to be related to phosphate limitation. This dissertation research provides insight into the physiological mechanisms behind the response of plants to elevated [CO2]. Across field experiments, water availability significantly alters response to elevated [CO2], with drier experiments showing a greater response. Within the soybean germplasm, height and partitioning coefficient both correlate to response to elevated [CO2]. There did not, however, appear to be a link between phloem loading strategy and response to elevated [CO2] and phloem loading capacity had mixed effects on response to elevated [CO2]. This research will be important for better estimating and maximizing response to elevated [CO2]

The Socio-Political Shaping And Lived Consequences Of Involuntary Retirement For Women With MS

Women with multiple sclerosis (MS) face a number of challenges negotiating and maintaining work, and are at risk for involuntary retirement and associated consequences. Few studies have positioned involuntary retirement and such consequences in socio-political contexts or examined their implications in women’s lives. This study critically examines the socio-political production and lived consequences of involuntary retirement for women with MS within the contemporary context of Southwestern Ontario. Employing critical narrative inquiry, informed by critical life course theory and disability studies perspectives with an intersectional lens, narratives of work and retirement were co-constructed with five women with MS who self-identified as retired. Four main themes evolved from critical narrative analysis, including: negotiating the disconnect between retirement as imagined, and retirement as lived; the production of consequences in navigating ableist environments requiring certainty and the intersection of bodily and financial uncertainty; the failure of practices, systems and policies to understand the complex, intersectional reality of women with MS, and the navigation of identity tensions; and filling the gap. These themes reveal various dimensions of the socio-political shaping of involuntary retirement, generating insights regarding how stigma and marginalization shape if and how women navigate workplace accommodations; problematics related to the conceptualization of disability embedded in provincial and federal disability policies and benefit programs; and implications of the absence of an intersectional lens within policies. In relation to the lived consequences of involuntary retirement, these thematic findings are drawn upon to point to the utility of precarity as a lens to examine experiences of instability, unpredictability and uncertainty amongst women with MS. The discussion also highlights how existing social policies and systemic discrimination create the necessity of re-imagining idealized retirements, as well as how the lives of the participants became increasingly more precarious after involuntary retirement given the downloading of responsibilities to manage gaps in existing systems and structures. This thesis responds to a number of important gaps by critically and qualitatively exploring involuntary retirement for women with MS in Ontario, Canada to provide rich accounts of shaping forces and lived consequences produced

The Role of Molecular Microtubule Motors and the Microtubule Cytoskeleton in Stress Granule Dynamics

Stress granules (SGs) are cytoplasmic foci that appear in cells exposed to stress-induced translational inhibition. SGs function as a triage center, where mRNAs are sorted for storage, degradation, and translation reinitiation. The underlying mechanisms of SGs dynamics are still being characterized, although many key players have been identified. The main components of SGs are stalled 48S preinitiation complexes. To date, many other proteins have also been found to localize in SGs and are hypothesized to function in SG dynamics. Most recently, the microtubule cytoskeleton and associated motor proteins have been demonstrated to function in SG dynamics. In this paper, we will discuss current literature examining the function of microtubules and the molecular microtubule motors in SG assembly, coalescence, movement, composition, organization, and disassembly

Modularity and Intrinsic Evolvability of Hsp90-Buffered Change

Hsp90 controls dramatic phenotypic transitions in a wide array of morphological features of many organisms. The genetic-background dependence of specific abnormalities and their response to laboratory selection suggested Hsp90 could be an ‘evolutionary capacitor’, allowing developmental variation to accumulate as neutral alleles under normal conditions and manifest selectable morphological differences during environmental stress. The relevance of Hsp90-buffered variation for evolution has been most often challenged by the idea that large morphological changes controlled by Hsp90 are unconditionally deleterious. To address this issue, we tested an Hsp90-buffered abnormality in Drosophila for unselected pleiotropic effects and correlated fitness costs. Up to 120-fold differences in penetrance among six highly related selection lines, started from an initially small number of flies and rapidly selected for and against a deformed eye trait (dfe), did not translate into measurable differences in any of several tests of viability, lifespan or competitive fitness. Nor were 17 dfe Quantitative Trait Loci (QTL) associated with fitness effects in over 1,400 recombinant lines. Our ability to detect measurable effects of inbreeding, media environment and the white mutation in the selection line backgrounds independent of dfe penetrance suggests that, within the limitations of laboratory tests of fitness, this large morphological change controlled by Hsp90 was selectable independent of strong, correlated and unconditionally deleterious effects—abundant, polygenic variation hidden by Hsp90 allows potentially deleterious alleles to be readily replaced during selection by less deleterious alleles with similar phenotypic effects. Hsp90 links environmental stress with the expression of developmental variation controlling unprecedented morphological plasticity. As outlined here and in the companion paper of this issue, the complex genetic architecture of Hsp90-buffered variation supports a remarkable modularity of Hsp90 effects on quantitative and qualitative phenotypes, consistent with the ‘Hsp90 capacitor hypothesis’ and standard quantitative genetic models of threshold traits

Deaminase-independent inhibition of HIV-1 reverse transcription by APOBEC3G

APOBEC3G (A3G), a host protein that inhibits HIV-1 reverse transcription and replication in the absence of Vif, displays cytidine deaminase and single-stranded (ss) nucleic acid binding activities. HIV-1 nucleocapsid protein (NC) also binds nucleic acids and has a unique property, nucleic acid chaperone activity, which is crucial for efficient reverse transcription. Here we report the interplay between A3G, NC and reverse transcriptase (RT) and the effect of highly purified A3G on individual reactions that occur during reverse transcription. We find that A3G did not affect the kinetics of NC-mediated annealing reactions, nor did it inhibit RNase H cleavage. In sharp contrast, A3G significantly inhibited all RT-catalyzed DNA elongation reactions with or without NC. In the case of (−) strong-stop DNA synthesis, the inhibition was independent of A3G's catalytic activity. Fluorescence anisotropy and single molecule DNA stretching analyses indicated that NC has a higher nucleic acid binding affinity than A3G, but more importantly, displays faster association/disassociation kinetics. RT binds to ssDNA with a much lower affinity than either NC or A3G. These data support a novel mechanism for deaminase-independent inhibition of reverse transcription that is determined by critical differences in the nucleic acid binding properties of A3G, NC and RT