The study of "Loop" Markov Chains

The purpose of my research is the study of ”Loop” Markov Chains. This model contains several loops, which could be connected at several different points. The focal point of this thesis will be when these loops are connected at one single point. Inside each loop are finitely many points. If the process is currently at the position where all the loops are connected, it will stay at its current position or move to the first position in any loop with a positive probability. Once within the loop, the movement can be deterministic or random. We’ll consider the Optimal Stopping Problem for finding the optimal stopping set and the Spectral Analysis for our ”Loop” system. As a basis, we’ll start with the Elimination Algorithm and a modified version of the Elimination Algorithm. None of these algorithms are efficient enough for finding the optimal stopping set of our ”Loop” Markov Chain; therefore, I propose a second modification of the Elimination Algorithm, the Lift Algorithm. The ”Loop” Markov Chain will dictate which algorithm or combination of algorithms, would be appropriate to find the optimal set. The second part of this thesis will examine the Analysis of the Covariance Operator for our ”Loop” Markov Chain system

Is the leadership in the black church complicit in the perpetuation of dominance and oppression?

This dissertation investigates the relationship between church leadership and parishioners and hypothesizes that the leadership in the black church is complicit in the perpetuation of dominating and oppressive behaviors within the communities that are directly and indirectly served by the church. Chapter I chronicles socio-economic patterns in black church leadership from the time of slavery to the 21st Century and documents probable reasons and purposes for the behaviors of leaders. Issues concerning power and dominance, denominationalism, racism, classism, and sexism are integral to the investigation. Two central questions arise: (1) "Does the religious leadership of the black church unknowingly train congregations to internalize negative feelings, connotations, and behaviors regarding critical reflection, critical thinking, and critical questioning." (2) "Is this lack of critical questioning detrimental to a forward movement of liberation and social justice for African American people?" Chapter II reviews the concepts of authority, power, and commodification as they relate to the silencing and injustice encountered when followers fail to voice their criticisms or other opinions. The concepts of authoritarianism and free-market fundamentalism as described by Cornel West in Democracy Matters (2004) are used to interrogate the relationship between leadership and parishioner and to determine the degree to which parishioners are encouraged to reflect upon and to question practices and behaviors of the leadership. Chapter III reports the results of the interviews with five black church leaders who reflected on their own practices. They were questioned about who influenced them, their accepted philosophy of leadership, their relationships with "others", and their efforts to bring about social justice in their communities. Female and male black church leaders were interviewed in an effort to illuminate typical trends and patterns regarding leadership styles, attitudes toward critical questioning, and social justice practices. They were also asked to reflect upon their methods for promoting interaction among the congregation. It was determined that mentorship, self-identification, interaction and relationship have the ability to affect how leaders view, interact, and work for others. The general conclusions addressed personal, economic, and spiritual concepts that create complex situations when determining the needs of the people versus the needs of the self. The concluding chapter reviews each chapter's themes and issues a call to action that involves a paradigm shift from asking for change from the leaders to asking for change from the followers. The church body will renew their ability to imagine that which seems impossible (Caputo, 2001), will use the voice to speak out for alternative ways of worship (Cox, 1973), will question and examine practices of the leaders, and will accept new beginnings (Brueggemann, 2001) that engage the prophetic and transformational rather than maintain the stagnant and conventional ways of worshiping

Consistencies And Inconsistencies In Personality Ratings Among Knowledgeable Other Reporters

Most personality assessments rely on self-report, but the Realistic Accuracy Model (RAM) proposes that personality may be accurately perceived by others. The strongest reporters of a target's personality besides the target themselves are knowledgeable others. Research supports that spouses exhibit the strongest correspondence between self-reports and other-reports, followed by family members, then friends. This study uses a sample of 197 targets, 197 friends, and 151 family members to examine the consistencies and inconsistencies of personality ratings across nine traits. Based on the literature, I hypothesized that self-family reports and self-friend reports would be positively correlated, and that there would be stronger correlations between self-family reports than between self-friend reports. I also hypothesized that there would be a positivity bias for family reports of the target’s personality, and no significant bias among friend reports the target’s personality, relative to the self-reports. Both sets of knowledgeable others (friend-reporters and family-reporters) were consistent with their personality judgments of the target, with similar average correlations. Parents tended to be positively biased, relative to self-reports, for the traits Extraversion, Agreeableness, Self-Esteem, and Integrity. Friends tended to be negatively biased, relative to self-reports, for the traits Openness to Experience and Intellect

Vestibular schwannoma: role of conservative management

Objective: To assess the outcome of conservative management of vestibular schwannoma.Study design: Observational study. Setting: Tertiary referral centre.Patients: Four hundred and thirty-six patients with vestibular schwannoma (490 tumours), including 327 sporadic tumours and 163 tumours in 109 patients with neurofibromatosis type two.Main outcome measures: The relationship of tumour growth to tumour size at presentation, and to certain demographic features.Results: The initial tumour size was significantly larger in the neurofibromatosis type two group (11 mm) than in the sporadic vestibular schwannoma group (5.1 mm). In both groups, 68 per cent of tumours did not grow during follow up (mean 3.6 years; range one to 14 years). The mean growth rate was 1.1 mm/year (range 0-15 mm/year) for sporadic tumours and 1.7 mm/year (range 0-18 mm/year) for neurofibromatosis type two tumours. The tumour growth rate correlated positively with tumour size in the sporadic tumour group, and correlated negatively with age in the neurofibromatosis type two group.Conclusion: Two-thirds of vestibular schwannomas did not grow. Radiological surveillance is an acceptable approach in carefully selected patients. Once a sporadic vestibular schwannoma reaches 2 cm in intracranial diameter, it is likely to continue growing. We do not recommend conservative management for sporadic tumours with an intracranial diameter of 1.5 cm or more. Vestibular schwannoma management is more complex in patients with neurofibromatosis type two

Dense Breasts: Different Than the Rest: Evaluating the Timeliness and Feasibility of Application of a Breast Cancer Screening Tool in a Primary Care Pilot Project

Background: The best outcomes for cancer are directly related to early detection. Accounting for factors, including breast density, is highly important for decreasing mortality. Purpose: The purpose of the pilot project is to discern if there is an appropriate breast cancer screening for patients with dense breasts that can be utilized in primary care. Methods: A literature search performed to determine options for a screening tool. Once saturation was met the literature was used to choose one tool to be implemented into clinical practice. The Tyrer Cuzick was determined to fit the criteria of breast density as a screening factor. The tool was utilized by a Nurse Practitioner in a rural primary care practice. Results: The Tyrer Cuzick screening tool is effective in guiding clinical practice for women with dense breasts and in guiding adjunct imaging care. There were not enough patients who met inclusion criteria during the time frame to meet standards for clinical significance.  Recommendations and Conclusion: The Tyrer Cuzick is a valuable tool for screening for lifetime breast cancer risk and can assist in guidance of necessity in adjunct screening and genetic testing recommendations. It would be beneficial if the screening could be streamlined for time management purposes. For replication, a larger sample size as well as a longer time frame would be beneficial for evaluating usefulness in clinical practice

Co-occurrence of ecologically similar species of Hawaiian spiders reveals critical early phase of adaptive radiation

Background: The processes through which populations originate and diversify ecologically in the initial stages of adaptive radiation are little understood because we lack information on critical steps of early divergence. A key question is, at what point do closely related species interact, setting the stage for competition and ecological specialization? The Hawaiian Islands provide an ideal system to explore the early stages of adaptive radiation because the islands span ages from 0.5–5 Mya. Hawaiian spiders in the genus Tetragnatha have undergone adaptive radiation, with one lineage (“spiny legs�) showing four different ecomorphs (green, maroon, large brown, small brown); one representative of each ecomorph is generally found at any site on the older islands. Given that the early stages of adaptive radiation are characterized by allopatric divergence between populations of the same ecomorph, the question is, what are the steps towards subsequent co-occurrence of different ecomorphs? Using a transcriptome-based exon capture approach, we focus on early divergence among close relatives of the green ecomorph to understand processes associated with co-occurrence within the same ecomorph at the early stages of adaptive radiation. Results: The major outcomes from the current study are first that closely related species within the same green ecomorph of spiny leg Tetragnatha co-occur on the same single volcano on East Maui, and second that there is no evidence of genetic admixture between these ecologically equivalent species. Further, that multiple genetic lineages exist on a single volcano on Maui suggests that there are no inherent dispersal barriers and that the observed limited distribution of taxa reflects competitive exclusion. Conclusions: The observation of co-occurrence of ecologically equivalent species on the young volcano of Maui provides a missing link in the process of adaptive radiation between the point when recently divergent species of the same ecomorph occur in allopatry, to the point where different ecomorphs co-occur at a site, as found throughout the older islands. More importantly, the ability of close relatives of the same ecomorph to interact, without admixture, may provide the conditions necessary for ecological divergence and independent evolution of ecomorphs associated with adaptive radiation

Structural Insight into How Bacteria Prevent Interference between Multiple Divergent Type IV Secretion Systems

Prokaryotes use type IV secretion systems (T4SSs) to translocate substrates (e.g., nucleoprotein, DNA, and protein) and/or elaborate surface structures (i.e., pili or adhesins). Bacterial genomes may encode multiple T4SSs, e.g., there are three functionally divergent T4SSs in some Bartonella species (vir, vbh, and trw). In a unique case, most rickettsial species encode a T4SS (rvh) enriched with gene duplication. Within single genomes, the evolutionary and functional implications of cross-system interchangeability of analogous T4SS protein components remains poorly understood. To lend insight into cross-system interchangeability, we analyzed the VirB8 family of T4SS channel proteins. Crystal structures of three VirB8 and two TrwG Bartonella proteins revealed highly conserved C-terminal periplasmic domain folds and dimerization interfaces, despite tremendous sequence divergence. This implies remarkable structural constraints for VirB8 components in the assembly of a functional T4SS. VirB8/TrwG heterodimers, determined via bacterial two-hybrid assays and molecular modeling, indicate that differential expression of trw and vir systems is the likely barrier to VirB8-TrwG interchangeability. We also determined the crystal structure of Rickettsia typhi RvhB8-II and modeled its coexpressed divergent paralog RvhB8-I. Remarkably, while RvhB8-I dimerizes and is structurally similar to other VirB8 proteins, the RvhB8-II dimer interface deviates substantially from other VirB8 structures, potentially preventing RvhB8-I/RvhB8-II heterodimerization. For the rvh T4SS, the evolution of divergent VirB8 paralogs implies a functional diversification that is unknown in other T4SSs. Collectively, our data identify two different constraints (spatiotemporal for Bartonella trw and vir T4SSs and structural for rvh T4SSs) that mediate the functionality of multiple divergent T4SSs within a single bacterium. IMPORTANCE:&nbsp; Assembly of multiprotein complexes at the right time and at the right cellular location is a fundamentally important task for any organism. In this respect, bacteria that express multiple analogous type IV secretion systems (T4SSs), each composed of around 12 different components, face an overwhelming complexity. Our work here presents the first structural investigation on factors regulating the maintenance of multiple T4SSs within a single bacterium. The structural data imply that the T4SS-expressing bacteria rely on two strategies to prevent cross-system interchangeability: (i) tight temporal regulation of expression or (ii) rapid diversification of the T4SS components. T4SSs are ideal drug targets provided that no analogous counterparts are known from eukaryotes. Drugs targeting the barriers to cross-system interchangeability (i.e., regulators) could dysregulate the structural and functional independence of discrete systems, potentially creating interference that prevents their efficient coordination throughout bacterial infection.</p

A novel method for standardized application of fungal spore coatings for mosquito exposure bioassays

<p>Abstract</p> <p>Background</p> <p>Interest in the use of fungal entomopathogens against malaria vectors is growing. Fungal spores infect insects via the cuticle and can be applied directly on the insect to evaluate infectivity. For flying insects such as mosquitoes, however, application of fungal suspensions on resting surfaces is more realistic and representative of field settings. For this type of exposure, it is essential to apply specific amounts of fungal spores homogeneously over a surface for testing the effects of fungal dose and exposure time. Contemporary methods such as spraying or brushing spore suspensions onto substrates do not produce the uniformity and consistency that standardized laboratory assays require. Two novel fungus application methods using equipment developed in the paint industry are presented and compared.</p> <p>Methods</p> <p>Wired, stainless steel K-bars were tested and optimized for coating fungal spore suspensions onto paper substrates. Different solvents and substrates were evaluated. Two types of coating techniques were compared, i.e. manual and automated coating. A standardized bioassay set-up was designed for testing coated spores against malaria mosquitoes.</p> <p>Results</p> <p>K-bar coating provided consistent applications of spore layers onto paper substrates. Viscous Ondina oil formulations were not suitable and significantly reduced spore infectivity. Evaporative Shellsol T solvent dried quickly and resulted in high spore infectivity to mosquitoes. Smooth proofing papers were the most effective substrate and showed higher infectivity than cardboard substrates. Manually and mechanically applied spore coatings showed similar and reproducible effects on mosquito survival. The standardized mosquito exposure bioassay was effective and consistent in measuring effects of fungal dose and exposure time.</p> <p>Conclusions</p> <p>K-bar coating is a simple and consistent method for applying fungal spore suspensions onto paper substrates and can produce coating layers with accurate effective spore concentrations. The mosquito bioassay was suitable for evaluating fungal infectivity and virulence, allowing optimizations of spore dose and exposure time. Use of this standardized application method will help achieve reliable results that are exchangeable between different laboratories.</p

Vulnerability of the British swine industry to classical swine fever

Classical swine fever (CSF) is a notifiable, highly contagious viral disease of swine which results in severe welfare and economic consequences in affected countries. To improve preparedness, it is critical to have some understanding of how CSF would spread should it be introduced. Based on the data recorded during the 2000 epidemic of CSF in Great Britain (GB), a spatially explicit, premises-based model was developed to explore the risk of CSF spread in GB. We found that large outbreaks of CSF would be rare and generated from a limited number of areas in GB. Despite the consistently low vulnerability of the British swine industry to large CSF outbreaks, we identified concerns with respect to the role played by the non-commercial sector of the industry. The model further revealed how various epidemiological features may influence the spread of CSF in GB, highlighting the importance of between-farm biosecurity in preventing widespread dissemination of the virus. Knowledge of factors affecting the risk of spread are key components for surveillance planning and resource allocation, and this work provides a valuable stepping stone in guiding policy on CSF surveillance and control in GB