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Examining Alpha Peak Frequency and its Relationship to Sustained Attention and Memory.
No full textWhile fluctuations in sustained attention can negatively impact immediate behavioral performance, the relationship between periods of inattention (e.g., mind wandering) and later memory is currently unclear. The current study used EEG to examine whether the peak of an individual’s posterior alpha rhythm, as measured by Individual Alpha Frequency (IAF), can serve as an objective marker of inattention that predicts individual differences in long-term memory. IAF was measured during five-minutes of rest (IAF-rest) and during an incidental face-encoding task (IAF-task). We then investigated the relationship between these IAF measures and participants’ (1) attentional states, as measured by objective (behavioral) and subjective (self-report) measures of inattention, and (2) subsequent memory performance. IAF was stable over time between rest and task performance, in support of past literature demonstrating IAF as a stable neurophysiological trait marker. Both IAF-rest and IAF-task correlated with fluctuations in participants’ attentional state, as quantified by an objective measure of response omissions, such that participants with faster alpha oscillations demonstrated fewer response omissions. In addition, IAF-task positively correlated with subsequent memory performance, such that participants with faster alpha oscillations during encoding demonstrated better memory retrieval. Taken together, these results confirm the stability of IAF over time and suggest that individuals with higher IAF values may be better prepared to attend to incoming information and later remember it
Disparities in Perspectives of Justice Across Adversarial Lines.
No full textBased on this mixed methods approach, we found that the attorneys’ views were largely consistent with their respective institutional perspectives, although the adversaries share more commonalities than we would have thought. These oppositional attitudes towards the criminal justice system, then, manifested as varying definition of what is just and what is fair for defendants and victims, respectively. After embarking on this project, I have learned how the very format of the criminal justice process, which immediately separates the adversaries and their respective parties, yields stark ideological differences that inform every step of this process. Overall, the results of the project suggest that different positionalities and the subsequent, disparate theories of justice, as well as various forms of bias, yield problematic consequences that perpetuate structural violence and mass incarceration. The criticisms that the adversaries shared further assert that the adversarial trial system is a failing relic that no longer serves the needs of the public. However, our results also indicate that reform efforts will be painfully slow unless prosecutors and defense attorneys both step into the aisle and create a coalition for structural changes toward restorative practices. Although this idea may currently seem utopian at best, future studies may garner the momentum needed to spark this drastic change
Seasonality and determinants of child growth velocity and growth deficit in rural southwest Ethiopia.
No full textBackground: Ethiopia faces cyclic food insecurity that alternates between pre- and post- harvest seasons. Whether seasonal variation in access to food is associated with child growth has not been assessed empirically. Understanding seasonality of child growth velocity and growth deficit helps to improve efforts to track population interventions against malnutrition. The aim of this study was assess child growth velocity, growth deficit, and their determinants in rural southwest Ethiopia.Keywords: Seasonality, Growth velocity, Growth deficit, Rural Ethiopia.Springer Open
BACE1 elevation engendered by GGA3 deletion increases β-amyloid pathology in association with APP elevation and decreased CHL1 processing in 5XFAD mice.
No full textBackground: β-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the rate-limiting enzyme in the production of amyloid beta (Aβ), the toxic peptide that accumulates in the brains of Alzheimer's disease (AD) patients. Our previous studies have shown that the clathrin adaptor Golgi-localized γ-ear-containing ARF binding protein 3 (GGA3) plays a key role in the trafficking of BACE1 to lysosomes, where it is normally degraded. GGA3 depletion results in BACE1 stabilization both in vitro and in vivo. Moreover, levels of GGA3 are reduced and inversely related to BACE1 levels in post-mortem brains of AD patients.Keywords: Alzheimer disease, Amyloid-beta (Aβ), Beta-secretase 1 (BACE1), Golgi-localized γ-ear-containing ARF binding protein 3 (GGA3), Amyloid precursor protein (APP), Cell adhesion molecule L1 like protein (CHL1), Down syndrome.Springer Open
Competing priorities that rival health in adults on probation in Rhode Island: substance use recovery, employment, housing, and food intake.
No full textBackground: Individuals on probation experience economic disadvantage because their criminal records often prohibit gainful employment, which compromises their ability to access the basic components of wellbeing. Unemployment and underemployment have been studied as distinct phenomenon but no research has examined multiple determinants of health in aggregate or explored how these individuals prioritize each of these factors. This study identified and ranked competing priorities in adults on probation and qualitatively explored how these priorities impact health.Keywords: Criminal justice, Probation, Food insecurity, Hunger, Social determinants of health, Homeless, Substance use, Employment.Springer Open
TRANSCRIPTIONAL AND FUNCTIONAL HETEROGENEITY DURING CARDIAC CELLULAR DIFFERENTIATION
No full textAbstract: A hallmark of development and disease is the cellular phenotypic diversification required for three-dimensional tissue structures. Cellular heterogeneity contributes to the developmental dynamics of various cell types, such as stem cells, neurons and cancer. In the heart, the coordinated differentiation, lineage diversification, and functional maturation of heterogeneous populations of cells is a prerequisite for the proper development of coordinated electrical and contractile function. Although a number of single-cell transcriptional profiling studies have provided insight into how intracellular signaling is regulated at the single-cell transcriptional level during cardiac development, the functional significance of transcriptomic diversity remains challenging to assess. Collectively, a fundamental goal in the biological sciences is to determine how individual cells with varied gene expression profiles and diverse functional characteristics contribute to development, physiology, and disease. Here, we report a novel strategy to assess gene expression and cell physiology in a multiplexed fashion in single living cells. Our approach utilizes fluorescently-labeled mRNA-specific anti-sense RNA probes and dsRNA-binding protein to identify the expression of specific genes in real-time at single-cell resolution via FRET. In proof-of-principle experiments, we visualize the β-actin mRNA in single living cells and demonstrate a heterogeneous mRNA subcellular localization pattern in cardiac myocytes. To employ our technology for the multiplex analysis of gene expression in individual living cells, we optimize spectral imaging to faithfully resolve multiple FRET pairs. We then use this technology to identify multiple distinct myocardial subpopulations expressing the structural proteins myosin heavy chain α and myosin light chain 2a in real-time during early differentiation of pluripotent stem cells. We combine this live-cell gene expression analysis with detailed physiologic phenotyping to capture the functional evolution of these early myocardial subpopulations during lineage specification and diversification. We further exploit the multiplex potential of our technology to identify multiple myocardial subpopulations expressing MHCα, MLC2a and the cardiac transcription factor NKX2-5 at single-cell resolution. Our results show that the expression of multiple key players of a cellular differentiation program is directly linked with the functional outcome at single-cell resolution and further that progression in cellular differentiation is tightly associated with functional evolution. This live-cell mRNA imaging approach has the broader potential to study how the expression of specific genes regulates single-cell physiology and will have wide ranging application wherever cellular heterogeneity plays an important biological role.Thesis (Ph.D.)--Tufts University, 2018.Submitted to the Dept. of Biomedical Engineering.Advisors: Ibrahim Domian, and Lauren Black III.Committee: David Kaplan, and Navin Kapur.Keywords: Biomedical engineering, and Biology
Characterization of MCF-12A cell phenotype, response to estrogens, and growth in 3D.
No full textBackground: Three-dimensional cultures of mammary epithelial cells allow for biologically-relevant studies of the development of the mammary gland in rodents and humans under normal and pathological conditions, like carcinogenesis. Under these conditions, mammotropic hormones play significant roles in tissue morphogenesis. Therefore, a system that recreates the normal, hormonally responsive epithelium would be a valuable tool to study the normal state and its transition to carcinogenesis. MCF-12A cells have been claimed to be non-tumorigenic mammary epithelial cells with reported sensitivity to estrogens. In this study, we aimed at characterizing MCF-12A cells for use in a hormone-responsive 3D culture system to determine their usefulness as a tool to identify normal and abnormal microenvironmental cues.Keywords: Estrogen response, 3D culture, Tissue morphogenesis.Springer Open
Duality in an asset exchange model for wealth distribution.
No full textAsset exchange models are agent-based economic models with binary transactions. Previous investigations have augmented these models with mechanisms for wealth redistribution, quantified by a parameter , and for trading bias favoring wealthier agents, quantified by a parameter . By deriving and analyzing a Fokker-Planck equation for a particular asset exchange model thus augmented, it has been shown that it exhibits a second-order phase transition at , between regimes with and without partial wealth condensation. In the "subcritical" regime with , all of the wealth is classically distributed; in the "supercritical" regime with , a fraction of the wealth is condensed. Intuitively, one may associate the supercritical, wealth-condensed regime as reflecting the presence of "oligarchy," by which we mean that an infinitesimal fraction of the total agents hold a finite fraction of the total wealth in the continuum limit. In this paper, we further elucidate the phase behavior of this model - and hence of the generalized solutions of the Fokker-Planck equation that describes it - by demonstrating the existence of a remarkable symmetry between its supercritical and subcritical regimes in the steady-state. Noting that the replacement , which clearly has the effect of inverting the order parameter , provides a one-to-one correspondence between the subcritical and supercritical states, we demonstrate that the wealth distribution of the subcritical state is identical to that of the corresponding supercritical state when the oligarchy is removed from the latter. We demonstrate this result analytically, both from the microscopic agent-level model and from its macroscopic Fokker-Planck description, as well as numerically. We argue that this symmetry is a kind of duality, analogous to the famous Kramers-Wannier duality between the subcritical and supercritical states of the Ising model, and to the Maldacena duality that underlies AdS/CFT theory