White Female Identity-Building in Colonial Africa

This paper won an honorable mention writing flag award in the research category. It was written for Ruramisai Charumbira's HIS 350L class, "Becoming African: Europeans in Southern African History".Charumbira, RuramisaiUndergraduate Studie

Surface Thermodynamics of Decanoic Acid

While modern cell membranes are composed of phospholipids, primitive membranes were probably made from simpler fatty acids. Due to the prebiotic availability of fatty acids, fatty acid vesicles are a popular model for proto-cell membranes in origin-of-life studies. Vesicles of one such fatty acid, decanoic acid, are often used to model early membranes, but the mechanism by which decanoic acid forms vesicles is not clear. Monolayer studies of the stability of decanoic acid on water surfaces may help illuminate the key molecular interactions that result in vesicle formation. To this end, consistent amounts of decanoic acid were deposited on the surface of aqueous salt and buffer solutions, and a variety of isotherms were collected with a Langmuir trough and Wilhelmy balance. Time versus surface pressure isotherms were analyzed and it was found that there was no statistical difference in the isotherms collected on 50 mM and 500 mM NaCl, indicating that the effects of salt on the phase behavior of decanoic acid might plateau at a lower concentration. However, the isotherms run on a Tris buffer substrate were statistically different from the isotherms at both salt concentrations. These preliminary results suggest that pH and buffer type are influential on decanoic acid surface partitioning and stability, and that the speed of equilibration increases at higher bulk ionic strength

Nonpharmacological prevention of osteoporotic fractures

Osteoporosis is a systemic, metabolic disease that can result in debilitating fractures. The lasting effects of vertebral and hip fractures can cause acute and chronic pain, deformity, and emotional distress. Research evidence and clinical experience have determined that weight bearing and strength training exercise, fall prevention efforts, hip protectors, and some alternative therapies may assist patients in avoiding the pervasive and lasting effects of osteoporotic fractures. Clinicians should consider the recommendations of nonpharmacological measures to assist patients at risk for experiencing the culminating event of this destructive disease

Macrophyte Communities of Lake Winnebago: Baseline Study of Species Composition with Abundances and Water Quality Conditions

Historical records from Lake Winnebago show minimal macrophyte growth; however, reports from recent years claim that macrophyte growth in some areas of the lake has reached nuisance levels. This study aimed to investigate the species of macrophytes present and their abundances in four near-shore locations, as well as measurements of multiple water quality conditions. Rake sampling was used to identify species and quantify their abundances and distributions. In addition, data were collected on light penetration, Secchi depths, and suspended algae chlorophyll concentrations at each site. These data from shallow near-shore sites reveal trends in changing water clarity and light penetration when compared to past and current data from deep-water sites. Macrophytes find habitats with increased light penetration advantageous for growth and competition; this suggests that the macrophyte species may have flourished recently due to comparatively better water clarity. In addition to two dominant native species, Coontail and Wild Celery, we also observed two invasive species (Eurasian Watermilfoil and Curly-leaf Pondweed). Eurasian Watermilfoil was found in high abundances in three out of the four sampling sites. Possible causes of increased water clarity, in particular the invasion of zebra mussels, will also be discussed. This study provides baseline data on the current macrophyte communities and will facilitate further exploration of recent changes in growth conditions that have resulted in such high abundances of macrophytes

Transcriptomic Insights into the Diplontic Life History of Diatoms

An organism\u27s life cycle is the direct result of its evolutionary history and represents a fundamental aspect of its ancestry and ecology. Yet the process of linking alternating life-history stages has proven to be challenging, if not impossible in some cases. Diatoms (Bacillariophyceae) are no exception to this challenge, and their diversity of life stages and reproductive strategies add further challenges. A central focus of diatom research has been to unravel the evolutionary events that led to their extraordinary diversity, a line of inquiry that has been greatly aided by the availability of next-generation sequence data. Yet without proper taxonomic sampling, many fundamental questions have remained unresolved. Furthermore, the incorporation of data from outgroup lineages provides crucial insights into the ancestral state of a taxon. However the life cycle of the sister lineage to diatoms, the Bolidophytes, has also remained an enigma. Here, to address yet unresolved questions about the origin of the diatom life cycle, transcriptomes for Bolidomonas pacifica (Bolidophyceae) and two diploid diatoms, Leptocylindrus danicus and Hemiaulus sinensis (Bacillariophyceae) were sequenced and analyzed. A novel approach of quantifying the degree of heterozygosity across the genome was used to infer the ploidy in Bolidomonas, whose ploidy level is unknown. Lack of heterozygous alleles in Bolidomonas strongly suggests that it is a vegetatively haploid organism, and the presence of several meiosis-specific genes indicate that it is likely capable of sexual reproduction as well. These results suggest that Bolidomonas represents the haploid phase of a haplodiplonitic life cycle, in which silicified Parmaleans are the diploid phase

Critical neural networks with short and long term plasticity

In recent years self organised critical neuronal models have provided insights regarding the origin of the experimentally observed avalanching behaviour of neuronal systems. It has been shown that dynamical synapses, as a form of short-term plasticity, can cause critical neuronal dynamics. Whereas long-term plasticity, such as hebbian or activity dependent plasticity, have a crucial role in shaping the network structure and endowing neural systems with learning abilities. In this work we provide a model which combines both plasticity mechanisms, acting on two different time-scales. The measured avalanche statistics are compatible with experimental results for both the avalanche size and duration distribution with biologically observed percentages of inhibitory neurons. The time-series of neuronal activity exhibits temporal bursts leading to 1/f decay in the power spectrum. The presence of long-term plasticity gives the system the ability to learn binary rules such as XOR, providing the foundation of future research on more complicated tasks such as pattern recognition.Comment: 8 pages, 7 figure

The Impact of Parenting Practices and Early Childhood Curricula on Children's Academic Achievement and Social Competence

Current research highlights the importance of early social competence for later academic success. Nevertheless, despite that documented importance, the emphasis in both policy and practice has been on academic achievement in early learning curricula. The proposed research had three objectives: 1) to understand how parenting behaviors toward children in kindergarten influence their academic achievement in third grade, 2) to understand how curriculum in kindergarten influences academic achievement in third grade, and 3) to ascertain whether social competence mediates the relationship between parenting factors in kindergarten and academic achievement in third grade and curriculum factors in kindergarten and academic achievement in the third grade. Data are drawn for the period 1998-2003 from an existing data set, the Early Childhood Longitudinal Study - Kindergarten Cohort (ECLS-K) and analyzed using multiple regression analyses. After controlling for background characteristics and academic achievement in kindergarten, these analyses revealed that the presence of spanking in kindergarten was significantly related to academic achievement in third grade. The presence of spanking in kindergarten was also related to children's learning related skills in third grade. Spanking and higher levels of warmth in kindergarten were related to children's interpersonal skills in third grade. Curriculum in kindergarten was unrelated to third grade academic achievement, social competence, and behavior problems. Social competence in third grade was related to academic achievement in third grade, while behavior problems were not. Finally, social competence mediated the relationship between spanking in kindergarten and academic achievement in third grade

Metamaterial-Based Soft Actuators

For this project the team was tasked with designing a soft actuator that incorporated aspects of mechanical metamaterials. The team’s goal was to demonstrate the feasibility of structural metamaterials in the field of soft robotics and demonstrate a novel response with a final assembly. Also included in the team\u27s discussion are the manufacturing steps, protype tests & results, and suggested future next steps. Following the previous report (critical design review) the team chose to follow the path of designing a continuum robot with metamaterials incorporated into the design. A continuum robot consists of a soft cylindrical body with rigid evenly placed plates and any number of actuating tendons. These tendons, when actuated, cause the plates to draw nearer to one another and the edges to bend to effectively create numerous possible degrees of freedom. To meet the primary goal of incorporating metamaterials the team designed multiple center-body and tip extension metamaterial segments. These segments were joined to the center-body via casting and other methods of joining. With these continuum bodies with different metamaterial inclusions, tests were conducted using a custom-built test stand. The test stand consists of four stepper motors, corresponding electronic microcontrollers and a system of pullies and guide-rods. The primary goal of achieving a unique and novel response with metamaterial inclusions was accomplished, however, full characterization of the test models was unable to be developed due to time constraints and component failures. Manufacturing methods and controller development took precedent in order to develop consistent models and testing for future work on the project

Global existence of small displacement solutions for Hookean incompressible viscoelasticity in 3D

The initial value problem for Hookean incompressible viscoelastictic motion in three space dimensions has global strong solutions with small displacements