Use of numerical PDE software for the solution of a classic problem in mathematical finance

1 online resource (68 p.) : ill.Includes abstract and appendix.Includes bibliographical references (p. 60-61).Mathematical modelling is an important part of the finance industry. These models can be very complex and one often needs to use numerical methods and numerical software packages to get approximate solutions to these models. In this thesis we use a high quality numerical software package called EPDCOL which is designed to solve systems of linear and non-linear partial differential equations (PDEs) and has temporal error control. Specifically, we will use it to numerically solve the Black-Scholes equation, a linear PDE, that can be used to value a financial instrument known as an option. An option is a contract which gives the holder the option to buy or sell a stock at a future time for an agreed upon price. A stock represents ownership of a corporation's assets and gives the opportunity to share in the corporation's earnings. EPDCOL implements a combination of high quality numerical methods which allow us to solve the Black-Scholes equation for two types of options (puts and calls) involving various parameters. Additionally, we are able to get an estimate of the spatial error associated with the numerical solutions

Rag GTPases are cardioprotective by regulating lysosomal function.

The Rag family proteins are Ras-like small GTPases that have a critical role in amino-acid-stimulated mTORC1 activation by recruiting mTORC1 to lysosome. Despite progress in the mechanistic understanding of Rag GTPases in mTORC1 activation, little is known about the physiological function of Rag GTPases in vivo. Here we show that loss of RagA and RagB (RagA/B) in cardiomyocytes results in hypertrophic cardiomyopathy and phenocopies lysosomal storage diseases, although mTORC1 activity is not substantially impaired in vivo. We demonstrate that despite upregulation of lysosomal protein expression by constitutive activation of the transcription factor EB (TFEB) in RagA/B knockout mouse embryonic fibroblasts, lysosomal acidification is compromised owing to decreased v-ATPase level in the lysosome fraction. Our study uncovers RagA/B GTPases as key regulators of lysosomal function and cardiac protection

Women’s decision making on birthing choices in the private sector of Namibia : midwives’ perspectives

CITATION: Mlambo, S., Young, C. & Morgan-Cramer, J. 2020. Women’s decision making on birthing choices in the private sector of Namibia : midwives’ perspectives. Africa Journal of Nursing and Midwifery, 22(1):6431, doi:/10.25159/2520-5293/6431.The original publication is available at https://journals.co.zaIn this study, the views of midwives regarding decision making in the Namibian private sector hospital labour wards were investigated with the aim of understanding the reasons for the high prevalence of caesarean sections in the Namibian private sector. The study objective was to determine the views of midwives about how women in the private sector labour wards decide on a birthing method. A qualitative design with an exploratory approach was followed, with the application of purposive sampling in the selection of research participants. Seven individual and in-depth interviews with midwives were conducted in two private hospitals in Windhoek. Data analysis was done using the six steps proposed by Creswell. Findings indicated that decision making depended on the woman, the doctor and the institution. Aspects such as the midwife’s relationship with the doctor, as well as the pregnant woman and the institution have an influence on such decisions made. Furthermore, the trust among and between health professionals, the availability of policies and guidelines, as well as the information received during antenatal care also affect the choice. It was found that women are not well informed about the choices they have for childbirth, the advantages and disadvantages of the chosen mode of birthing, as well as what to expect during the active stages of labour. In conclusion, decision making in the labour wards is important as it determines the birthing method outcome for every woman in the labour ward. Further studies need to be done in the same context and public hospital settings, to explore the dynamics in the public sector.https://journals.co.za/doi/abs/10.25159/2520-5293/6431Publisher's versio

FGF4 retrogene on CFA12 is responsible for chondrodystrophy and intervertebral disc disease in dogs.

Chondrodystrophy in dogs is defined by dysplastic, shortened long bones and premature degeneration and calcification of intervertebral discs. Independent genome-wide association analyses for skeletal dysplasia (short limbs) within a single breed (PBonferroni = 0.01) and intervertebral disc disease (IVDD) across breeds (PBonferroni = 4.0 × 10-10) both identified a significant association to the same region on CFA12. Whole genome sequencing identified a highly expressed FGF4 retrogene within this shared region. The FGF4 retrogene segregated with limb length and had an odds ratio of 51.23 (95% CI = 46.69, 56.20) for IVDD. Long bone length in dogs is a unique example of multiple disease-causing retrocopies of the same parental gene in a mammalian species. FGF signaling abnormalities have been associated with skeletal dysplasia in humans, and our findings present opportunities for both selective elimination of a medically and financially devastating disease in dogs and further understanding of the ever-growing complexity of retrogene biology

Assessment of empiric outpatient therapy and readmission rates from the emergency department for community acquired pneumonia

Background: Community acquired pneumonia (CAP) is a common reason for emergency department visits and is associated with high mortality and readmission rates. The Center for Medicare and Medicaid Services (CMS) aims to decrease readmission rates for pneumonia through their Hospital Readmissions Reduction Program (HRRP) that was initiated in 2012. One study investigated avoidable causes of CAP readmission and discovered that the highest percentage of avoidable causes of readmission was related to discharging patients with either missing or incorrect diagnosis or therapy (31.7%). Emergency department (ED) physicians are in a unique position to impact these factors, as they are often responsible for initial diagnosis and empiric therapy initiation. The purpose of this study is to identify adherence to guideline-recommended empiric therapy and utilize the data to develop targeted interventions to refine our current practices.Methods: This study was performed as a single-center, retrospective, observational chart review. The study period was July 1, 2021-June 30, 2022, and the study included ED patients with an ICD-10 diagnosis code for pneumonia. Patients were independently reviewed by two investigators, with a third available for final statistical decision if needed. Each patient was reviewed for inclusion and exclusion criteria, and appropriateness of empiric therapy was evaluated according to the 2019 CAP guidelines. Patients were also reviewed for readmission within 30 days.Results: Data collection and analysis is still ongoing for this project. There were 169 total patients with a diagnosis code for CAP discharged from the emergency department during the pre-specified timeframe. For preliminary results 39 charts have been completed. 29 charts met inclusion criteria. Of these, only 2 had received appropriate empiric therapy. There were 10 total readmissions, with 3 of them being due to worsening pneumonia. None of the patients readmitted for worsening pneumonia had received appropriate empiric therapy. Extended duration and incomplete regimens for patients with comorbidities were the most common reasons for inappropriate therapy. Based on preliminary data, only 6% of patients received appropriate empiric therapy for CAP. Readmission rate overall was 35%, and rate of readmission for worsening pneumonia was 10%.Conclusions: Based on preliminary data, overall prescribing habits from the emergency department are not adherent with the guidelines. There is insufficient data to draw conclusions about the effect of this on readmission. Targeted provider education will be developed based on the most common reasons for incorrect therapy, with the goal of improving guideline adherence

COLD GASS, an IRAM legacy survey of molecular gas in massive galaxies: I. Relations between H2, HI, stellar content and structural properties

We are conducting COLD GASS, a legacy survey for molecular gas in nearby galaxies. Using the IRAM 30m telescope, we measure the CO(1-0) line in a sample of ~350 nearby (D=100-200 Mpc), massive galaxies (log(M*/Msun)>10.0). The sample is selected purely according to stellar mass, and therefore provides an unbiased view of molecular gas in these systems. By combining the IRAM data with SDSS photometry and spectroscopy, GALEX imaging and high-quality Arecibo HI data, we investigate the partition of condensed baryons between stars, atomic gas and molecular gas in 0.1-10L* galaxies. In this paper, we present CO luminosities and molecular hydrogen masses for the first 222 galaxies. The overall CO detection rate is 54%, but our survey also uncovers the existence of sharp thresholds in galaxy structural parameters such as stellar mass surface density and concentration index, below which all galaxies have a measurable cold gas component but above which the detection rate of the CO line drops suddenly. The mean molecular gas fraction MH2/M* of the CO detections is 0.066+/-0.039, and this fraction does not depend on stellar mass, but is a strong function of NUV-r colour. Through stacking, we set a firm upper limit of MH2/M*=0.0016+/-0.0005 for red galaxies with NUV-r>5.0. The average molecular-to-atomic hydrogen ratio in present-day galaxies is 0.3, with significant scatter from one galaxy to the next. The existence of strong detection thresholds in both the HI and CO lines suggests that "quenching" processes have occurred in these systems. Intriguingly, atomic gas strongly dominates in the minority of galaxies with significant cold gas that lie above these thresholds. This suggests that some re-accretion of gas may still be possible following the quenching event.Comment: Accepted for publications in MNRAS. 32 pages, 25 figure

Portland Region Parks: Measuring Equity in Access

The goal of this Capstone project is to examine equity as it applies to the Portland region. CLF defines equity as “the right of every person to have access to opportunities necessary for satisfying essential needs and advancing their well-being” (CLF, 2007). Equity as it relates to parks is a difficult concept to define. Our project specifically focused on cataloging the amenities of ninety-three newly developed parks and making observations about park access in an effort to build a better picture of what equity looks like in the Portland region

A Complex Regulatory Network Coordinating Cell Cycles During C. elegans Development Is Revealed by a Genome-Wide RNAi Screen

The development and homeostasis of multicellular animals requires precise coordination of cell division and differentiation. We performed a genome-wide RNA interference screen in Caenorhabditis elegans to reveal the components of a regulatory network that promotes developmentally programmed cell-cycle quiescence. The 107 identified genes are predicted to constitute regulatory networks that are conserved among higher animals because almost half of the genes are represented by clear human orthologs. Using a series of mutant backgrounds to assess their genetic activities, the RNA interference clones displaying similar properties were clustered to establish potential regulatory relationships within the network. This approach uncovered four distinct genetic pathways controlling cell-cycle entry during intestinal organogenesis. The enhanced phenotypes observed for animals carrying compound mutations attest to the collaboration between distinct mechanisms to ensure strict developmental regulation of cell cycles. Moreover, we characterized ubc-25, a gene encoding an E2 ubiquitin-conjugating enzyme whose human ortholog, UBE2Q2, is deregulated in several cancers. Our genetic analyses suggested that ubc-25 acts in a linear pathway with cul-1/Cul1, in parallel to pathways employing cki-1/p27 and lin-35/pRb to promote cell-cycle quiescence. Further investigation of the potential regulatory mechanism demonstrated that ubc-25 activity negatively regulates CYE-1/cyclin E protein abundance in vivo. Together, our results show that the ubc-25-mediated pathway acts within a complex network that integrates the actions of multiple molecular mechanisms to control cell cycles during development