New Bivariate Lifetime Distributions Based on Bath-Tub Shaped Failure Rate

A class of lifetime distributions which has received considerable attention in modelling and analysis of lifetime data is the class of lifetime distributions with bath-tub shaped failure rate functions because of their extensive applications. The purpose of this thesis was to introduce a new class of bivariate lifetime distributions with bath-tub shaped failure rates (BTFRFs). In this research, first we reviewed univariate lifetime distributions with bath-tub shaped failure rates, and several multivariate extensions of a univariate failure rate function. Then we introduced a new class of bivariate distributions with bath-tub shaped failure rates (hazard gradients). Specifically, the new class of bivariate lifetime distributions were developed using the method of Morgenstern’s method of defining bivariate class of distributions with given marginals. The computer simulations and numerical computations were used to investigate the properties of these distributions

Forest Evolution

The forest we enjoy today is very different from the forest 100 years ago in Missouri. Forests have undergone excessive cutting during the 19th century. After that, US and state governments implemented forest regeneration programs that ensure harvests for the future. Forest can be a renewable resource if we manage it in a sustainable way. The site is separated into three parts, each part applying different strategy: selective cutting and natural regeneration, selective cutting and replanting, clear cutting and replanting. I will plant far more trees than I remove. I use a 20’ by 20’ grid to visualize the density of existing trees. In the less dense grids, I plant white oak and red maple, which is commonly used wood materials. The three part has different function. At the selective cutting and natural regeneration area, I leave open lawn in the middle, following the drip line of remaining trees; at the selective cutting and replanting area, I propose a plaza for gathering. At the clearcutting and replanting area, I propose several circles of wood pavement surrounded by wood benches for resting. The circles follow the drip line of the cutting down trees and the remained trunks are left for commemoration. There are wood signs in each area telling people about the forestry strategies and wood industry. All the wood materials in the design is made of cutting down trees.https://openscholarship.wustl.edu/fall2019_stanek/1003/thumbnail.jp

Madness, Death, and Civilization: Non-European Women under Patriarchy and Imperialism

In light of Wide Sargasso Sea, through which Jean Rhys intends to provide the madwoman Bertha in Jane Eyre with a voice and a life, this thesis attempts to reread Jane Eyre from a postcolonial perspective, arguing that both texts can be read as critiques of the cruelty and inhumanity of European civilization. After the English beat the Spanish at sea, and complete the First Industrial Revolution, it establishes the country as the greatest imperialistic power in the world. The need of labor, raw material, and new market leads them to develop colonies in remote areas like the Caribbean. By claiming a civilized and therefore higher status, the English carry out cruel enforcement of the English law in the colonies, and justify their exploitation and oppression by concocting sex and race theory, which situate themselves on the privileged side of the binary pairs such as human/nature, male/female, and reason/emotion. Suffering from the dualism of colonial expansion, non-European women are often inferiorized and dehumanized from a Eurocentric perspective. In Victorian literature, it is not rare to see that those women often end their stories either with madness, or death. This thesis gives a detailed analysis of how and why Antoinette/Bertha is represented as one of the civilization’s discontent, a character who is driven to madness and death by Rochester, her English husband. Ultimately, she burns with the Thornfield Hall to criticize the patriarchal and imperial ideology of English civilization

The relationship between gut microbiota and inflammatory response, learning and memory in mice by sleep deprivation

ObjectiveSleep deprivation has developed into a common phenomenon, which can lead to inflammatory responses and cognitive impairment, but the underlying mechanism is ambiguous. Emerging evidence shows that gut microbiota plays a crucial role in theoccurrence and development of inflammatory and psychiatric diseases, possibly through neuroinflammation and the brain-gut axis. The current study investigated the influence of sleep deprivation on gut microbiota composition, pro-inflammatory cytokines, learning and memory in mice. Further, it explored whether changes in gut microbiota increase pro-inflammatory cytokine and induce learning and memory impairment.MethodsHealthy 8-week-old male C57BL/6J mice were randomly divided into the regular control group (RC), environmental control group (EC), and sleep deprivation group (SD). The sleep deprivation model was established by the Modified Multiple Platform Method. The experimental mice were subjected to sleep deprivation for 6h/d (8:00 am∼14:00 pm) in a sleep deprivation chamber, and the duration of sleep deprivation was 8 weeks. Morris water maze test to assess learning and memory in mice. Enzyme-Linked Immunosorbent Assay determined the concentrations of inflammatory cytokines. The changes in gut microbiota in mice were analyzed by 16S rRNA sequencing.ResultsWe found that SD mice had elevated latency of exploration to reach the hidden platform (p>0.05) and significantly decreased traversing times, swimming distance, and swimming time in the target zone when the hidden platform was removed (p<0.05). Sleep deprivation caused dysregulated expression in serum IL-1β, IL-6, and TNF-α in mice, and the difference was significant (all p<0.001). Tannerellaceae, Rhodospirillales, Alistipes, and Parabacteroides were significantly increased in SD mice. Correlation analysis showed IL-1β was positively correlated with the abundance of Muribaculaceae (r=0.497, p<0.05) and negatively correlated with the abundance of Lachnospiraceae (r=-0.583, p<0.05). The TNF-α was positively correlated with the abundances of Erysipelotrichaceae, Burkholderiaceae, and Tannerellaceae (r=0.492, r=0.646, r=0.726, all p<0.05).ConclusionSleep deprivation can increase pro-inflammatory cytokine responses and learning and memory impairment in mice and may be caused by the disorder of the microbiota. These findings of this study may open avenues for potential interventions that can relieve the detrimental consequences of sleep loss