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- Creators: School of International Letters and Cultures
- Status: Published
Down syndrome (DS) is a common genetic developmental disorder characterized by the trisomy of chromosome 21 (Hsa21). All individuals with DS have some kind of intellectual disability, associated with dysfunction in cognition-related structures, including the frontal cortex. Studies have examined developmental changes in the frontal cortex during prenatal stages in DS, however little is known about cortical lamination and neuronal differentiation in postnatal periods in this neurodevelopmental disorder. Therefore, we examined the quantitative and qualitative distribution of neuronal profiles containing the neuronal migration protein doublecortin (DCX), the non-phosphorylated high-molecular-weight neurofilament SMI-32, the calcium-binding proteins calbindin D-28K (Calb), calretinin (Calr), and parvalbumin (Parv), as well as human β-amyloid and APP (6E10), Aβ1-42, and phospho-tau (CP-13) in the supragranular (SG, II/III) and infragranular (IG, V/VI) layers in the DS postnatal frontal cortex compared to neurotypically developing (NTD) controls from ages 28 weeks to 196.4 weeks using immunohistochemistry. Furthermore, cortical lamination was evaluated using thionin, a Nissl stain. We found DCX-immunoreactive (-ir) cells in both the SG and IG layers in younger cases, but not in the oldest cases in both groups. Strong expression of SMI-32 immunoreactivity was observed in pyramidal cells in layers III and V in the oldest cases in both groups, however SMI-32-ir cells appeared much earlier in NTD compared to DS. We found small and fusiform Calb-ir cells in the younger cases (28 to 44 weeks), while in the oldest cases, Calb immunoreactivity was also found in pyramidal cells. Calr-ir cells appeared earlier in DS at 32 weeks compared to NTD at 44 weeks, however both groups showed large bipolar fusiform-shaped Calr-ir cells in the oldest cases. Diffuse APP/Aβ-ir plaque-like accumulations were found in the frontal cortex grey and white matter at all ages, but no Aβ1-42 immunoreactivity was detected in any case. Furthermore, neuropil (but not cellular) granular CP-13 immunostaining was seen in layer I only at 41 weeks NTD and 33 weeks DS. Cell counts show a significantly higher cell number in SG compared to IG for all the neuronal markers in both groups, except in Calb and SMI-32. In NTD, age and brain weight showed the strongest correlations with all cellular counts, except in thionin where DS had a stronger negative correlation with age and brain weight compared to NTD. In addition, height and body weight showed a strong negative correlation in NTD with the migration and neurogenesis marker DCX. These findings suggest that trisomy 21 affects the postnatal frontal cortex lamination, neuronal migration<br/>eurogenesis, and differentiation of projection pyramidal cells and interneurons, which contribute to the disruption of the local and projection inhibitory and excitatory circuitries that may underlie the cognitive disabilities in DS.
Social isolation in early childhood can have life-long effects on social behaviors and development. Cerebellar crus I has additionally been linked to social behaviors through forebrain pathways. In this study, we hypothesized that social isolation of mice from postnatal day 21 (P21) until p35 would result in impaired social behaviors. Additionally, we hypothesized that gq DREADD injections into crus I, to increase levels of cerebellar stimulation, at the start of the isolation period would counteract the effects of isolation, leading to mice who displayed normal social behaviors. Social behavior at P35 was tested using the 3-Chamber Task, a well-established model, and SLEAP deep-learning software was used to obtain quantifiable data. We found no difference in social behaviors between socially raised and isolated mice. However, gq DREADD mice displayed greater levels of social interaction and exploration than either socially raised mice or isolated mice. This research carries implications for possible therapeutic interventions for groups prone to social isolation, such as those with developmental disabilities, minority groups, the elderly, and prison populations.
Supply & Demand, the phrase speaks to the tango between college graduates seeking employment & employers seeking talent. Recruiters desire candidates with employability skills to lead, but report significant skill gaps among applicants. This thesis aims to (1) define the skills gap evidenced by employers, (2) determine students’ career preparedness, and (3) identify strategies to bridge the gap among undergraduate students as they prepare to join the workforce. Qualtrics, an experience management, and survey platform, was used to reach and collect information from nearly 1,200 students in order to quantitatively assess their career development skills and needs. As part of this thesis, I have partnered with the T.W. Lewis Center for Personal Development, a center of Barrett, The Honors College at Arizona State University in an effort to test and provide effective solutions to bridge the employability skills gap. Through this collaboration, we have constructed a Career Development Workshop Series for students using the data collected from students. The workshop was built to teach students about professional skill topics that they desired to learn about, but could not find on or off-campus. The Lewis Center Career Development Workshop is a 5-part series with topics ranging from negotiation and job interviewing to strength-building. In each workshop, an expert is selected as the guest speaker to share their experience and insights with students as they prepare for their career journeys. Guest speakers include CEOs, entrepreneurs, business executives, and more. The series is intended to deepen students’ business acumen, so they can enter the workforce with a sustainable advantage and ultimately supported the professional and personal growth of over 100 students. The series serves as an example of ways our university can improve its career development offerings to students. In an increasingly competitive labor market, the research collected and solutions presented are designed to empower students in their careers.
The purpose of this paper is to examine cross-cultural differences between the United States and Turkey by coding multiple dimensions, such as parental intrusiveness, child persistence, and various others. The main research questions of this paper were as follows: (1) How does parental intrusiveness vary by country? (2) How does child persistence vary by country? and (3) Are parental intrusiveness and child persistence correlated, and if so, what is the direction of the correlation? The hypotheses were that (1) Turkish parents would score higher on parental intrusiveness, (2) American children would show higher levels of persistence, and (3) Parental intrusiveness and child persistence are correlated, with higher levels of parental intrusiveness resulting in lower levels of child persistence. While all of the hypotheses were supported with statistically significant results, it was found that in the U.S., higher parental intrusiveness does result in lower levels of child persistence, but in Turkey, parental intrusiveness was not a predictor of child persistence. The findings are therefore able to support cross-cultural differences in the correlation between parental intrusiveness and child persistence.