Maximum and Minimum Stable Random Packings of Platonic Solids

Motivated by the relation between particle shape and packing, we measure the volume fraction $\phi$ occupied by the Platonic solids which are a class of polyhedron with congruent sides, vertices and dihedral angles. Tetrahedron, cube, octahedron, dodecahedron, and icosahedron shaped plastic dice were fluidized or mechanically vibrated to find stable random loose packing $\phi_{rlp} = 0.51, 0.54, 0.52, 0.51, 0.50$ and densest packing $\phi_{rcp} = 0.64, 0.67, 0.64, 0.63, 0.59$, respectively with standard deviation $\simeq \pm 0.01$. We find that $\phi$ obtained by all protocols peak at the cube, which is the only Platonic solid that can tessellate space, and then monotonically decrease with number of sides. This overall trend is similar but systematically lower than the maximum $\phi$ reported for frictionless Platonic solids, and below $\phi_{rlp}$ of spheres for the loose packings. Experiments with ceramic tetrahedron were also conducted, and higher friction was observed to lead to lower $\phi$

Seed Corn Tournament Contracts and Excess Nitrogen Application

Crop Production/Industries,

Too Fast: Coloniality and Time in Wylers of St. Kitts and Nevis

Wylers, the popular music most strongly associated with the annual Christmas carnival in St. Kitts and Nevis, is generally regarded as â??too fast.â?? And yet, while wylers is broadly understood as â??too fast,â?? metric analysis of representative songs does not indicate a major difference in tempo or beats per minute between wylers and other, widely accepted, popular Caribbean music such as Trinidadian Power soca or Dominican bouyon. Why, then, is wylers perceived as â??too fast?â?? What is at stake in making this claimâ??that is, too fast for whom or for what? This dissertation examines the varied and highly divergent answers that emerge in response to these questions. Ultimately, a case is made for understanding the rhetoric surrounding wylers as indicative of the strong legacy of colonialismâ??colonialityâ??that informs the ways people perceive certain types of sounds and movements. This project, then, illustrates the presence of historically contextual, and ethically grounded conceptions of tempo and â??fastnessâ?? even in the postcolonial moment. I argue that being, sounding, and moving â??too fastâ?? in St. Kitts and Nevis are the local, temporal, sonic, and embodied deployments of decolonial aesthesis as a response to and rejection of colonial aesthetics as an upholding tenant of coloniality. Following the contours of local discourse in St. Kitts and Nevis, I deploy the colloquial, Kittitian-Nevisian Creole definitions of the word â??fastâ?? and the phrase â??too fastâ?? as thematic guides in order to examine 1.) Notions of unauthorized musicianship and untimely musicality and 2.) Black female performances of sexuality and citizenship. Through use of ethnographic and historical methodologies, I argue that unconventional modes of musicianship and unrespectable performances of female sexual expression are â??too fastâ?? in their relationship to colonial mores of respectability. I consider how appeals to and valuations of manners of being, sounding, and moving â??too fastâ?? carve out aesthetic and ontological space for decolonial possibility.

Effects of Genetics and Sex on Hippocampal Gene Expression and Adolescent Behaviors Following Neonatal Ethanol Exposure in BXD Recombinant Inbred Mice

Fetal alcohol spectrum disorders (FASD) are the leading preventable neurodevelopmental disorders in the western world. A hallmark symptom of FASD is cognitive and learning deficits that present in early childhood and continue throughout adulthood. Teratogenic effects of alcohol include increased cell death in the hippocampus, a brain region critically important in learning and memory. Genetics have been shown to have a role in the severity of alcohol’s teratogenic effect on the developing brain. Previous work in our lab identified differential vulnerability to ethanol-induced call death in the hippocampus using fourteen BXD strains and the two parental strains. The goal of the present study was to examine the effect of genetics and sex on differential gene expression changes and behavioral responses in animals exposed to postnatal ethanol. To test this, we examined multiple BXD strains that showed increased susceptibility to ethanol-induced cell death in the hippocampus, multiple BXD strains that were resistant to ethanol’s effect on hippocampal cell death, and the parental B6 and D2 strains which showed moderate levels of cell death in the hippocampus after ethanol exposure. Neonatal mice were treated on postnatal day 7 (third trimester equivalent in humans). Animals received a subcutaneous injection of either 5.0g/kg ethanol in saline solution or isovolumetric saline given in two equal doses two hours apart. Animals were sacrificed 7 hours after initial ethanol exposure. Differential gene expression was examined using the Affymetrix Microarray platform across the strains. In another subset of animals exposed to the same alcohol paradigm, we investigated the long-term effects of developmental alcohol exposure on cognition and behavior in select BXD strains and parental strains. Adolescent animals exposed to postnatal ethanol were tested across the following behavioral tests: elevated plus maze, open field, Y-maze, and T-maze. We identified gene expression changes after postnatal ethanol exposure in all BXD and parental strains with little overlap between males and females in the same strain. However, there were limited gene expression changes that showed a sex x treatment interaction. Sex-specific ethanol-induced gene expression changes were limited within each strain and these changes were not carried over across strains. Multiple genes showed a significant interaction between strain x treatment and/or strain x sex x treatment. Enrichment analysis of these genes revealed a number of significant over-represented biological categories involved in cell death and apoptosis. Genes that met our criteria and were also highly correlated with a number of apoptosis and learning and memory behaviors included Bcl2l11, Jun, Txnip, Chka, and Tgfb3. Interestingly, Tgfb3 has been previously linked to a significant QTL mediating strain-specific differences in hippocampal cell death after exposure to postnatal ethanol in BXD mice. When comparing ethanol-induced gene expression changes in high cell death strains (HCD) and low cell death strains (LCD), we observed almost double the number of differentially ethanol-induced gene expression changes in the HCD strains compared to the LCD strains. Enrichment analysis revealed some overlap in significant over-represented categories between the HCD and LCD strains, though HCD showed more cell death and apoptosis categories. Significant ethanol-induced gene expression changes in the HCD and LCD strains were always regulated in the same direction suggesting 1) more perturbed effects of ethanol-induced gene expression changes in the HCD strains compared to LCD strains and 2) limited gene expression changes that confer resistance to ethanol-induced cell death in the hippocampus in the LCD strains. In our behavioral study, our results demonstrate that the effects of developmental alcohol exposure on adolescent behavioral responses are highly dependent on strain, though the strains that showed the most behavioral alterations after exposure to postnatal alcohol were the B6 and D2 parental strains and the BXD100 and BXD48a HCD strains. In these four strains, we observed many anxiety-like and activity-related behaviors that were significantly affected by postnatal ethanol exposure and in many of these measures there were sex-specific differences within the strain. The LCD strains, BXD60 and BXD71, showed minimal effect of treatment in all behavioral tests. Interestingly, the HCD strains, BXD100 and BXD48a, were the only strains that showed significant effect of postnatal ethanol exposure in hippocampal-dependent spatial learning and memory assessment. These results suggest that there are long-term effects of developmental alcohol exposure on adolescent behavior and that these effects are highly strain specific. Overall, our study aimed to better understand genetic variation in ethanol-induced susceptibility to ethanol’s teratogenic effects. Our results accomplish this by identifying differential gene expression changes and behavioral responses in animals exposed to postnatal ethanol using the BXD RI mice and parental strains. Additionally, our study identified sex differences in both ethanol-induced gene expression changes and adolescent behaviors in mice exposed to postnatal ethanol, though sex-specific effects were highly dependent on strain. To our knowledge, this is the first study using the BXD RI strains to examine the effects of genetics and sex on 1) ethanol-induced gene expression changes during development, and 2) adolescent behaviors in mice exposed to postnatal ethanol

Relations among dimensions of emotion regulation and aggressive behavior

In the absence of the ability to adaptively regulate one’s emotions, individuals may turn to impulsive and maladaptive methods of regulation, including engaging in aggressive behavior. Gratz and Roemer’s (2004) model of emotion regulation (Multidimensional assessment of emotion regulation and dysregulation: Development, factor structure, and initial validation of the Difficulties in Emotion Regulation Scale. Journal of Psychopathology and Behavioral Assessment, 26(1), 41-54) includes the dimensions of nonacceptance, difficulties engaging in goal-directed behavior, impulse control difficulties, lack of emotional awareness, access to emotion regulation strategies, and lack of emotional clarity. This study sought to identify the relations among these dimensions and the broader constructs of emotional experiencing (i.e., affect intensity), emotional awareness (i.e., mindfulness), emotional clarity, (i.e., alexithymia), acceptance of emotions (i.e., experiential avoidance), and overall emotion regulation skillfulness (i.e., difficulties in emotion regulation) and the relative contributions of each of these dimensions to aggression utilizing web-based surveys administered to a college student sample (n = 307). Affect intensity was not significantly related to emotion regulation or to aggression. Regression analyses indicated that experiential avoidance predicts overall aggression, physical aggression, verbal aggression, hostility, and anger. Difficulty with impulse control when distressed predicted overall aggression, physical aggression, and anger. Access to emotion regulation strategies predicted hostility. These findings suggest that experiential avoidance may have an important role in aggressive behaviors and could be an effective target for intervention

Assessment and improvement of hydraulic disinfection efficiency of a live small drinking water system in South Africa

2018 Spring.Includes bibliographical references.Since the implementation of chlorination, the most common method of water disinfection, diseases such as Cholera, Typhoid Fever, and Dysentery have been essentially eliminated in the U.S. and other industrialized countries (WHO 2017). However, these nations still experience challenges in meeting drinking water standards. In 2009, the Colorado Department of Public Health and Environment contracted Colorado State University (CSU)'s Department of Civil and Environmental Engineering to address the poor hydraulic disinfection efficiency of contact tanks of small-scale drinking water systems. From this research, the Baffling Factor Guidance Manual (2014) was published, which presents innovative modifications proven to increase the hydraulic disinfection efficiency of small-scale contact tanks. The proposed innovative technology has the potential to have a significant positive impact in developing nations since at least 2 billion people worldwide use a drinking water source that is contaminated with feces (WHO 2017). Historical experience suggests that simply transporting a technology does not necessarily equate to long-lasting impact, but how that technology is transferred is critical to its sustainability. A successful solution to the need for disinfected water must be holistic, taking into consideration culture, law, politics, economics, environment, etc. The focus of this thesis is to investigate further the application of the innovative contact tank modifications of an inlet manifold and random packing material (RPM) on live systems. A case study was conducted on a small waterworks in the rural town of Rosetta, KwaZulu-Natal, South Africa, in collaboration with Umgeni Water. Physical tracer tests were conducted on a 10,000L cylindrical tank acting as the contact chamber to assess the hydraulic disinfection efficiency in terms of baffling factor (BF), before and after the installation of a 4-way inlet manifold modification. This modification resulted in a 37% improvement in the BF, increasing the contact time (CT), an important aspect of disinfection, in the cylindrical contact tank from 8.4 min-mg/L to 11.0 min-mg/L. In addition to the international case study, a pilot study was conducted at CSU to address the biofilm formation concerns of the innovative use of random packing material (RPM) in contact tanks. Preliminary results support the hypothesis that the presence of a disinfectant in the contact tank, though in the process of disinfecting the water, would mitigate the growth of a biofilm on the RPM

Assessment of applicability and transferability of evidence-based antenatal interventions to the Australian indigenous setting

There is a need for public health interventions to be based on the best available evidence. Unfortunately, well-conducted studies from settings similar to that in which an intervention is to be implemented are often not available. Therefore, health practitioners are forced to make judgements about proven effective interventions in one setting and their suitability to make a difference in their own setting. The framework of Wang et al. has been proposed to help with this process. This paper provides a case study on the application of the framework to a decision-making process regarding antenatal care in Aboriginal and Torres Strait Islander communities in Queensland. This method involved undertaking a systematic search of the current available evidence, then conducting a second literature search to determine factors that may affect the applicability and transferability of these interventions into these communities. Finally, in consideration of these factors, clinical judgement decisions on the applicability and transferability of these interventions were made. This method identified several interventions or strategies for which there was evidence of improving antenatal care or outcomes. By using the framework, we concluded that several of these effective interventions would be feasible in Aboriginal and Torres Strait Islander communities within Queensland