Optimizing weak lensing mass estimates for cluster profile uncertainty

Weak lensing measurements of cluster masses are necessary for calibrating mass-observable relations (MORs) to investigate the growth of structure and the properties of dark energy. However, the measured cluster shear signal varies at fixed mass M_200m due to inherent ellipticity of background galaxies, intervening structures along the line of sight, and variations in the cluster structure due to scatter in concentrations, asphericity and substructure. We use N-body simulated halos to derive and evaluate a weak lensing circular aperture mass measurement M_ap that minimizes the mass estimate variance <(M_ap - M_200m)^2> in the presence of all these forms of variability. Depending on halo mass and observational conditions, the resulting mass estimator improves on M_ap filters optimized for circular NFW-profile clusters in the presence of uncorrelated large scale structure (LSS) about as much as the latter improve on an estimator that only minimizes the influence of shape noise. Optimizing for uncorrelated LSS while ignoring the variation of internal cluster structure puts too much weight on the profile near the cores of halos, and under some circumstances can even be worse than not accounting for LSS at all. We briefly discuss the impact of variability in cluster structure and correlated structures on the design and performance of weak lensing surveys intended to calibrate cluster MORs.Comment: 11 pages, 5 figures; accepted by MNRA

Connecting Theory, Knowledge, and Practice: A Review of Action Research for Nurses

Nurses are faced with everyday demands to improve practices, yet using research to develop and apply theory, knowledge, and practices is a task fraught with challenges to the nursing profession. McDonnell and McNiff (2016) offer a practical guide for novice nursing practitioners and researchers to understand and conduct action research

Paclitaxel Drug Elution from a Biodegradable Stent

Recently, drug-eluting stents have become a common treatment for coronary heart disease. These stents are usually loaded with a drug that prevents restenosis. Unfortunately, there are risks associated with the placement of these metallic structures in the body. Stent thrombosis is one such problem, and can lead to restenosis despite the presence of drug. Advances in biomaterials have led to the development of biodegradable stents, which can reduce the risks associated with stents. However, since it is a relatively new technology, it is not known to what degree the biodegradability affects the drug releasing properties of the stent. We hope to characterize these effects and to determine if the biodegradability reduces the efficacy of the stent when compared to normal non-degradable stents. To accomplish this, we modeled a stent that diminished in size over time using COMSOL Multiphysics, and monitored the drug concentration in the nearby tissue. We established that our model was a viable predictor of actual stent behavior by comparing our simulated results with previous studies. We were then able to determine the optimal initial loading stent concentration of our modeled drug, paclitaxel, to ensure therapeutic levels in the tissue. Lastly, we found that drug concentrations in the tissue were not substantially different between the degradable and non-degradable models. This affirms the effectiveness of using biodegradable stents, showing them as a viable alternative to traditional metal stents

Exploring TERT Expression and Regulation in Tumorigenesis: Lessons from ALV

Avian leukosis virus (ALV) is a simple retrovirus that infects chickens and causes cancer. Chickens exposed to ALV typically develop B-cell lymphomas within a few months after hatching. ALV-induced tumors have been shown to develop by insertional mutagenesis mediated by proviral integration. ALV proviral integration into the chicken genome disrupts the normal expression of neighboring host genes, commonly by promoter insertion and/or enhancer activation. Previous studies have identified several common proviral integration sites near genes that are now known to drive tumorigenesis. Notable genes include MYC, MYB, mir-155, and, more importantly, TERT. Unique clonal integrations in the TERT promoter suggest that they are early events in ALV-induced B-cell lymphomas. In this thesis, I report the results of overexpressing TERT in early chicken embryos coinfected with ALV in new in vivo experiments. Although no definite conclusion could be made about TERT overexpression and tumor progression, two tumors in one chicken were identified to retain the recombinant virus used to overexpress TERT. High-throughput sequencing analysis of integration sites in one tumor implicated genes previously described. In contrast, the other tumor implicated an AT-rich interacting transcriptional coactivator, ARIDB5, as the top potential cooperating gene in TERT overexpressing cells. In addition, we observed an unexpected prevalence of hemangiomas in our chickens infected with ALV-A, which is more commonly associated with ALV-J. Integration site analysis of multiple hemangiomas implicate an exclusive subset of genes that include FRK, PLAG1, and GLIS3. In human cancers, the association between TERT promoter methylation and TERT expression is an area of active investigation. The relationship between the two factors has proven to be complex and controversial. Proviral integration adds another layer of complexity. Investigation of clonal TERT promoter integrations by bisulfite sequencing showed that ALV integration is associated with a decrease in methylation of the flanking genomic DNA, suggesting that ALV may contribute to TERT expression by inhibiting methylation at the TERT promoter. Lastly, we surveyed an extensive subset of human hematological malignancies for the prevalence of previously reported TERT promoter mutations by conventional Sanger sequencing. TERT promoter mutations have been recently identified as a highly conserved and ubiquitous somatic change in various cancers where TERT expression has been directly induced. We observed a lack of TERT promoter mutations in the human samples tested, suggesting that TERT promoter mutations are not a prevalent mechanism of TERT activation in hematological malignancies

Social Skills Interventions for Adolescents with ASD, ADHD, and Other Comorbidities

This project was part of a research initiative to collaborate with Kristin Brubaker, MSOT, OTR/L, practicing pediatric occupational therapist at the Center for Therapeutic Intervention (CTI). CTI is an outpatient, private pediatric occupational therapy clinic in Gig Harbor, WA. The purpose of our project was to determine existing and effective interventions to improve social skills in adolescents, ages 11 to 18 years, with autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), sensory processing disorder (SPD) and other sensory processing issues. Our search of the literature yielded a total of 22 research studies, with the majority representing group-based interventions. Limited research was found pertaining to ADHD and no research was found pertaining to either SPD or sensory processing issues. Future research recommendations include a focus on developing and studying effective interventions for individuals with ADHD and SPD. Our knowledge translation products were specifically designed for CTI and included an in-service presentation detailing our research and findings, a proposed social skills program for a specific group of adolescents at CTI, and reference tools to use in creating future group-based programs. Post-presentation responses and feedback were overwhelmingly positive and well received

Policy proposals to select African states to optimize benefits from China's interest and investment in Africa

published_or_final_versionInternational and Public AffairsMasterMaster of International and Public Affair

Long-Term Recording of LTP in Cultured Hippocampal Slices

Long-term potentiation (LTP) was elicited by high frequency stimulation in hippocampal slices cultured on multi-electrode arrays. LTP lasting more than 1 h was recorded in 75% of slices, and a significant number of slices exhibited a non-decaying LTP that lasted more than 48 h. LTP induction was completely and reversibly blocked by an antagonist of the NMDA receptor, APV. Our results suggest the possibility of using chronic recording in hippocampal slices cultured on multi-electrode arrays to study the mechanisms underlying LTP maintenance and stabilization

Sustainability and Maturation of School Turnaround: A Multiyear Evaluation of Tennessee’s Achievement School District and Local Innovation Zones

Recent evaluations of reforms to improve low-performing schools have almost exclusively focused on shorter term effects. In this study, we extend the literature by examining the sustainability and maturation of two turnaround models in Tennessee: the state-led Achievement School District (ASD) and district-led local Innovation Zones (iZones). Using difference-in-differences models, we find overall positive effects on student achievement in iZone schools and null effects in ASD schools. Additional findings suggest a linkage between staff turnover and the effectiveness of reforms. ASD schools experienced high staff turnover in every cohort, and iZone schools faced high turnover in its latest cohort, the only one with negative effects. We discuss how differences in the ASD and iZone interventions may help explain variation in the schools’ ability to recruit and retain effective teachers and principals

Positive Identification of LSB Image Steganography Using Cover Image Comparisons

In this paper we introduce a new software concept specifically designed to allow the digital forensics professional to clearly identify and attribute instances of LSB image steganography by using the original cover image in side-by-side comparison with a suspected steganographic payload image. The “CounterSteg” software allows detailed analysis and comparison of both the original cover image and any modified image, using sophisticated bit- and color-channel visual depiction graphics. In certain cases, the steganographic software used for message transmission can be identified by the forensic analysis of LSB and other changes in the payload image. The paper demonstrates usage and typical forensic analysis with eight commonly available steganographic programs. Future work will attempt to automate the typical types of analysis and detection. This is important, as currently there is a steep rise in the use of image LSB steganographic techniques to hide the payload code used by malware and viruses, and for the purposes of data exfiltration. This results because of the fact that the hidden code and/or data can more easily bypass virus and malware signature detection in such a manner as being surreptitiously hidden in an otherwise innocuous image file

Cereal based diets modulate some markers of oxidative stress and inflammation in lean and obese Zucker rats

Extent: 10p.Background: The potential of cereals with high antioxidant capacity for reducing oxidative stress and inflammation in obesity is unknown. This study investigated the impact of wheat bran, barley or a control diet (α-cellulose) on the development of oxidative stress and inflammation in lean and obese Zucker rats. Methods: Seven wk old, lean and obese male Zucker rats (n = 8/group) were fed diets that contained wheat bran, barley or α-cellulose (control). After 3 months on these diets, systolic blood pressure was measured and plasma was analysed for glucose, insulin, lipids, oxygen radical absorbance capacity (ORAC), malondialdehyde, glutathione peroxidase and adipokine concentration (leptin, adiponectin, interleukin (IL)-1β, IL-6, TNFα, plasminogen activator inhibitor (PAI)-1, monocyte chemotactic protein (MCP)-1). Adipokine secretion rates from visceral and subcutaneous adipose tissue explants were also determined. Results: Obese rats had higher body weight, systolic blood pressure and fasting blood lipids, glucose, insulin, leptin and IL-1β in comparison to lean rats, and these measures were not reduced by consumption of wheat bran or barley based diets. Serum ORAC tended to be higher in obese rats fed wheat bran and barley in comparison to control (p = 0.06). Obese rats had higher plasma malondialdehyde (p < 0.01) and lower plasma glutathione peroxidase concentration (p < 0.01) but these levels were not affected by diet type. PAI-1 was elevated in the plasma of obese rats, and the wheat bran diet in comparison to the control group reduced PAI-1 to levels seen in the lean rats (p < 0.05). These changes in circulating PAI-1 levels could not be explained by PAI-1 secretion rates from visceral or subcutaneous adipose tissue. Conclusions: A 3-month dietary intervention was sufficient for Zucker obese rats to develop oxidative stress and systemic inflammation. Cereal-based diets with moderate and high antioxidant capacity elicited modest improvements in indices of oxidative stress and inflammation.Damien P Belobrajdic, Yan Y Lam, Mark Mano, Gary A Wittert and Anthony R Bir