Doctor of Philosophy

dissertationArctic sea ice is a key component of the climate system, acting as a reflective barrier between the ocean and the atmosphere. The decrease in sea ice over the observational record is associated with several feedback processes, such as the ice-albedo feedback. Here, general sea ice-atmosphere feedback (SAF) is defined in which a sea ice anomaly causes surface and tmospheric responses that either enhance the initial anomaly (positive feedback) or oppose the initial anomaly (negative feedback). Chapters 2 and 3 examine the local SAF over the Barents Sea in an uncoupled modeling framework. Results indicate that the SAF is positive and dominated by the thermodynamic component of the feedback, where anomalously high sea ice cover over the Barents sea favors additional ice growth because it decreases upward surface turbulent heat fluxes, leading to atmospheric cooling and reduced downwelling longwave radiation flux at the surface, while the opposite scenario occurs for anomalously low sea ice cover. Chapter 4 studies the effect of suppressing the SAF in a coupled model by exposing the atmosphere over the Barents Sea to surface turbulent heat fluxes, longwave heat fluxes, and surface temperatures weighted by climatological sea ice cover. Variability in sea ice, atmospheric temperature, and sea surface temperature decrease in response to SAF suppression, indicating that the coupled feedback over the Barents Sea is positive. While thermodynamic processes play a large role in regional sea ice-atmosphere interactions, wind-driven sea ice transport controls the overall Arctic ice mass on annual-and-shorter time scales. Most sea ice is exported from the Arctic through the Fram Strait, and changes in sea ice export are linked to hemispheric-scale atmospheric variability. In Chapter 5, the leading propagating patterns of variability associated with Fram Strait sea ice flux (F) are determined by applying Hilbert empirical orthogonal function analysis to reanalysis data. The leading two surface wind patterns are correlated with F when cyclonic and anticyclonic circulation features are positioned downstream and upstream of the Fram Strait, enhancing the northerly component of the flow through the Strait

Master of Science

thesisThe main objectives of this study were to identify the leading propagating patterns of atmospheric variability over the Midwest, and to determine the relationships of these patterns with Midwest precipitation. Complex Hilbert empirical orthogonal function (HEOF) analysis was performed on daily mean 850-hPa horizontal moisture transport, 850-hPa temperature advection, jet relative frequency, and the difference between 850-hPa and 250-hPa vorticity advection. Atmospheric fields were derived from the 6-hourly NCEP-NCAR reanalysis on a year-round and within-season basis. Additionally, the HEOFs were phase-shifted to maximize the correlation between the real part of the score series and area-weighted power-transformed Midwest precipitation. In the year-round analysis, the leading HEOF of combined jet relative relative frequency and 850-hPa horizontal moisture transport captured the seasonal migration of the jet and attendant low-level circulation features. The second HEOF showed high jet relative frequency over the Midwest on the upstream side of a trough, and moisture transport from the Gulf of Mexico into the Midwest. The leading within-season HEOF of combined jet relative relative frequency and 850-hPa horizontal moisture transport showed a similar pattern in winter, spring, and fall. In all seasons, the monthly mean scores of the leading HEOF of combined jet relative relative frequency and 850-hPa horizontal moisture transport were better estimates of Midwest precipitation than the Pacific-North American pattern, North Atlantic Oscillation, and El Ni˜no-Southern Oscillation teleconnection indices. In addition, this study examined the relationship between the leading winter propagating patterns of variability and lake effect precipitation over the Great Lakes region. Here, the leading HEOF of combined jet relative relative frequency and 850-hPa horizontal moisture transport was phase-shifted to maximize the correlation between the real part and a lake effect precipitation fraction time series. The phase-shifted HEOF did not resolve the mesoscale features of lake effect snow, but did position the synoptic-scale circulation so that flow developed the expected northerly component over the Great Lakes

Total prostatectomy as a treatment for prostatic carcinoma in 25 dogs

Objective: To describe the complications and outcome after total prostatectomy in dogs with histologically confirmed prostatic carcinoma. Study Design: Multi-institutional retrospective case series. Animals: 25 client-owned dogs. Methods: Medical records of dogs undergoing total prostatectomy were reviewed from 2004 to 2016. Data retrieved included signalment, presenting signs, preoperative clinical findings, laboratory data, diagnostic imaging, surgical technique, histologic diagnosis, postoperative complications, occurrence of postoperative metastasis, and survival. Results: Twenty-five dogs underwent total prostatectomy for prostatic carcinoma. Urinary anastomotic techniques included urethrourethral anastomosis in 14 dogs, cystourethral anastomosis in 9 dogs, ureterocolonic anastomosis in 1 dog, and anastomosis between the bladder neck and penile urethra in 1 dog. All dogs survived to discharge. Fifteen dogs were diagnosed with transitional cell carcinoma, 8 dogs with prostatic adenocarcinoma, 1 with prostatic cystadenocarcinoma, and 1 with an undifferentiated carcinoma. Permanent postoperative urinary incontinence was present in 8 of 23 dogs. The median survival time was shorter in dogs with extracapsular tumor extension compared with those with intracapsular tumors. The overall median survival time was 231 days (range, 24-1255), with 1- and 2-year survival rates equal to 32% and 12%, respectively. Conclusion and Clinical Significance: Total prostatectomy, combined with adjunct therapies, prolongs survival and lowers complication rates compared to previous reports of dogs with prostatic carcinoma. It should be noted, however, that case selection likely played a significant role in postoperative outcome

Rapid tests and urine sampling techniques for the diagnosis of urinary tract infection (UTI) in children under five years: a systematic review

Background: Urinary tract infection (UTI) is one of the most common sources of infection in children under five. Prompt diagnosis and treatment is important to reduce the risk of renal scarring. Rapid, cost-effective, methods of UTI diagnosis are required as an alternative to culture. Methods: We conducted a systematic review to determine the diagnostic accuracy of rapid tests for detecting UTI in children under five years of age. Results: The evidence supports the use of dipstick positive for both leukocyte esterase and nitrite (pooled LR+ = 28.2, 95% CI: 17.3, 46.0) or microscopy positive for both pyuria and bacteriuria (pooled LR+ = 37.0, 95% CI: 11.0, 125.9) to rule in UTI. Similarly dipstick negative for both LE and nitrite (Pooled LR- = 0.20, 95% CI: 0.16, 0.26) or microscopy negative for both pyuria and bacteriuria (Pooled LR- = 0.11, 95% CI: 0.05, 0.23) can be used to rule out UTI. A test for glucose showed promise in potty-trained children. However, all studies were over 30 years old. Further evaluation of this test may be useful. Conclusion: Dipstick negative for both LE and nitrite or microscopic analysis negative for both pyuria and bacteriuria of a clean voided urine, bag, or nappy/pad specimen may reasonably be used to rule out UTI. These patients can then reasonably be excluded from further investigation, without the need for confirmatory culture. Similarly, combinations of positive tests could be used to rule in UTI, and trigger further investigation

Measurement of νˉμ\bar{\nu}_{\mu} and νμ\nu_{\mu} charged current inclusive cross sections and their ratio with the T2K off-axis near detector

We report a measurement of cross section $\sigma(\nu_{\mu}+{\rm nucleus}\rightarrow\mu^{-}+X)$ and the first measurements of the cross section $\sigma(\bar{\nu}_{\mu}+{\rm nucleus}\rightarrow\mu^{+}+X)$ and their ratio $R(\frac{\sigma(\bar \nu)}{\sigma(\nu)})$ at (anti-)neutrino energies below 1.5 GeV. We determine the single momentum bin cross section measurements, averaged over the T2K $\bar{\nu}/\nu$-flux, for the detector target material (mainly Carbon, Oxygen, Hydrogen and Copper) with phase space restricted laboratory frame kinematics of $\theta_{\mu}$500 MeV/c. The results are $\sigma(\bar{\nu})=\left( 0.900\pm0.029{\rm (stat.)}\pm0.088{\rm (syst.)}\right)\times10^{-39}$ and $\sigma(\nu)=\left( 2.41\ \pm0.022{\rm{(stat.)}}\pm0.231{\rm (syst.)}\ \right)\times10^{-39}$in units of cm$^{2}$/nucleon and$R\left(\frac{\sigma(\bar{\nu})}{\sigma(\nu)}\right)= 0.373\pm0.012{\rm (stat.)}\pm0.015{\rm (syst.)}$.Comment: 18 pages, 8 figure

Measurement of differential cross section for proton-induced deuteron breakup at 108 MeV

The experiment was performed at CCB IFJ PAN in Kraków with the use of the BINA detector. The experimental program and data analysis of proton-induced deuteron breakup reaction at 108 MeV are presented