Self Portrait: You and I.

M.F.A. Thesis. University of Hawaiʻi at Mānoa 2018

Evaluación de criterios de selección de modelos probabilísticos: validación con series de valores máximos simulados

Se realizó un estudio de Monte Carlo para determinar la validez del empleo de la prueba del error estándar de ajuste como criterio de selección en el análisis de frecuencias. Dicho estadístico se comparó con los estadísticos de prueba de Kolmogorov-Smirnov, Cramer-Von Mises y AndersonDarling. Las distribuciones elegidas para el propósito de comparar estos estadísticos fueron la gamma, Weibull, Gumbel, log-normal y log-logística. Los resultados obtenidos recomiendan el uso de muestras con tamaño de por lo menos n = 50 para tener un buen desempeño de las pruebas de Anderson-Darling y error estándar de ajuste. El empleo de las pruebas de Kolmogorov-Smirnov y Cramer-Von Mises no es del todo recomendable en hidrología, ya que para obtener un desempeño aceptable se necesitan muestras más grandes de las que normalmente se tienen en esta disciplina

Economic Analysis of Wildlife Management Costs in the U.S. Forest Service, Northern Region

Paper published as Bulletin 47 in the UM Bulletin Forestry Series.https://scholarworks.umt.edu/umforestrybulletin/1030/thumbnail.jp

A cancer rainbow mouse for visualizing the functional genomics of oncogenic clonal expansion.

Field cancerization is a premalignant process marked by clones of oncogenic mutations spreading through the epithelium. The timescales of intestinal field cancerization can be variable and the mechanisms driving the rapid spread of oncogenic clones are unknown. Here we use a Cancer rainbow (Crainbow) modelling system for fluorescently barcoding somatic mutations and directly visualizing the clonal expansion and spread of oncogenes. Crainbow shows that mutations of ß-catenin (Ctnnb1) within the intestinal stem cell results in widespread expansion of oncogenes during perinatal development but not in adults. In contrast, mutations that extrinsically disrupt the stem cell microenvironment can spread in adult intestine without delay. We observe the rapid spread of premalignant clones in Crainbow mice expressing oncogenic Rspondin-3 (RSPO3), which occurs by increasing crypt fission and inhibiting crypt fixation. Crainbow modelling provides insight into how somatic mutations rapidly spread and a plausible mechanism for predetermining the intratumor heterogeneity found in colon cancers

Short gamma-ray bursts from SGR giant flares and neutron star mergers: two populations are better than one

‘The definitive version is available at www.blackwell-synergy.com.’ Copyright Blackwell Publishing. DOI: 10.1111/j.1365-2966.2009.14610.xThere is increasing evidence of a local population of short duration gamma-ray bursts (sGRB), but it remains to be seen whether this is a separate population to higher redshift bursts. Here we choose plausible luminosity functions (LFs) for both neutron star binary mergers and giant flares from soft gamma repeaters (SGR), and combined with theoretical and observed Galactic intrinsic rates we examine whether a single progenitor model can reproduce both the overall Burst and Transient Source Experiment (BATSE) sGRB number counts and a local population, or whether a dual progenitor population is required. Though there are large uncertainties in the intrinsic rates, we find that at least a bimodal LF consisting of lower and higher luminosity populations is required to reproduce both the overall BATSE sGRB number counts and a local burst distribution. Furthermore, the best-fitting parameters of the lower luminosity population agree well with the known properties of SGR giant flares, and the predicted numbers are sufficient to account for previous estimates of the local sGRB population.Peer reviewe

Tacrolimus versus Cyclosporine after Hematopoietic Cell Transplantation for Acquired Aplastic Anemia

AbstractCombinations of cyclosporine (CSP) with methotrexate (MTX) have been widely used for immunosuppression after allogeneic transplantation for acquired aplastic anemia. We compared outcomes with tacrolimus (TAC)+MTX versus CSP+MTX after transplantation from HLA-identical siblings (SIB) or unrelated donors (URD) in a retrospective cohort of 949 patients with severe aplastic anemia. Study endpoints included hematopoietic recovery, graft failure, acute graft-versus-host disease (GVHD), chronic GVHD, and mortality. TAC+MTX was used more frequently in older patients and, in recent years, in both SIB and URD groups. In multivariate analysis, TAC+MTX was associated with a lower risk of mortality in URD recipients and with slightly earlier absolute neutrophil count recovery in SIB recipients. Other outcomes did not differ statistically between the 2 regimens. No firm conclusions were reached regarding the relative merits of TAC+MTX versus CSP+MTX after hematopoietic cell transplantation for acquired aplastic anemia. Prospective studies would be needed to determine whether the use of TAC+MTX is associated with lower risk of mortality in URD recipients with acquired aplastic anemia

Reaction rates and transport in neutron stars

Understanding signals from neutron stars requires knowledge about the transport inside the star. We review the transport properties and the underlying reaction rates of dense hadronic and quark matter in the crust and the core of neutron stars and point out open problems and future directions.Comment: 74 pages; commissioned for the book "Physics and Astrophysics of Neutron Stars", NewCompStar COST Action MP1304; version 3: minor changes, references updated, overview graphic added in the introduction, improvements in Sec IV.A.