Data Analysis WorkbeNch (DAWN).

Synchrotron light source facilities worldwide generate terabytes of data in numerous incompatible data formats from a wide range of experiment types. The Data Analysis WorkbeNch (DAWN) was developed to address the challenge of providing a single visualization and analysis platform for data from any synchrotron experiment (including single-crystal and powder diffraction, tomography and spectroscopy), whilst also being sufficiently extensible for new specific use case analysis environments to be incorporated (e.g. ARPES, PEEM). In this work, the history and current state of DAWN are presented, with two case studies to demonstrate specific functionality. The first is an example of a data processing and reduction problem using the generic tools, whilst the second shows how these tools can be targeted to a specific scientific area.

Donor phosphorus levels and recipient outcomes in living-donor kidney transplantation.

BACKGROUND AND OBJECTIVES: In living-donor kidney transplantation, various donor factors, including gender, age, and baseline kidney function, predict allograft function and recipient outcomes after transplantation. Because higher phosphorus is predictive of vascular injury in healthy adults, the effect of donor phosphorus levels on recipient renal function after transplantation was investigated. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: Phosphorus levels in 241 living donors were analyzed from a 7-year period, and recipient renal function and acute rejection at 1 year posttransplantation were examined controlling for other influencing factors, including multiple donor variables, HLA matching, and acute rejection. RESULTS: Female and African-American donors had significantly higher phosphorus levels predonation. By multivariable analysis, higher donor phosphorus correlated with higher recipient serum creatinine (slope=0.087, 95% confidence interval [CI]: 0.004 to 0.169, P=0.041) and lower recipient estimated GFR (slope=-4.321, 95% CI: -8.165 to -0.476, P=0.028) at 12 months. Higher donor phosphorus also displayed an independent correlation with biopsy-proven acute rejection and delayed or slow graft function after transplantation. CONCLUSIONS: In a cohort of living kidney donors, higher donor phosphorus correlated with female gender and African-American ethnicity and was an independent risk factor for early allograft dysfunction after living-donor kidney transplantation.

Re-exposure to mismatched HLA class I is a significant risk factor for graft loss: multivariable analysis of 259 kidney retransplants.

BACKGROUND: Kidney retransplants carry increased immunologic risk. One possible contributor to this risk may be re-exposure to human leukocyte antigens (HLA) common to a previous donor but foreign to the recipient. Conflicting publications have assessed this risk, so to examine our experience 259 kidney retransplants were analyzed. METHODS: A retrospective cohort of retransplant patients from 1973 to 2005 with minimum 12 months follow up was examined. Using multivariable modeling, important confounders were controlled for identifying factors significantly affecting graft survival. RESULTS: Re-exposure to HLA class I (HLA-A or B) antigens, peak panel reactive antibodies and donor source were the most important determinants of allograft survival, despite a negative conventional or anti-human globulin-augmented T cell crossmatch. We failed to demonstrate that recipient re-exposure to HLA class II (HLA-DR) or positive B cell crossmatch were associated with adverse outcomes. Sample size and molecular versus serologic methods may have influenced the former, while inability to determine antibody specificities may have influenced the latter. Controlling for other variables, the adjusted risk of graft loss associated with re-exposure to HLA class I increased by 71% (P=0.006) and occurred early, consistent with recall of memory cytotoxic T lymphocyte or antibody responses. CONCLUSIONS: Kidney recipients re-exposed to mismatched HLA class I antigens appear to be at heightened risk of early graft loss. Such patients may benefit from pretransplant identification of donor specific antibodies using solid phase methods and heightened vigilance for acute rejection. Future studies may indicate whether more intensive immunosuppression for these patients is warranted.

Improved renal function after conversion from tacrolimus/sirolimus to tacrolimus/mycophenolate mofetil in kidney transplant recipients.

BACKGROUND: There is limited data on the potential nephrotoxicity of sirolimus (SRL) and tacrolimus (TAC) in combination. METHODS: We reviewed the course of 97 kidney transplant patients treated with SRL and reduced-dose TAC. Conversion from SRL to mycophenolate mofetil (MMF) was prescribed in a minority (n = 19) for various nonrenal side effects. We compared outcomes of converted patients to those remaining on TAC/SRL (n = 78). RESULTS: TAC levels were increased in converters (P = 0.009). Rejection rates were similar between groups over 18 months (21% vs. 16%, p = ns). Serum creatinine (Cr) and MDRD glomerular filtration rate (GFR) were similar between groups at nadir and six-months, but at 18 months the percent change from six-month Cr was +17% in non-converters vs. -10% in converters (P = 0.004 for the difference). The difference in GFR between groups at 18 months was also significant (P = 0.01). By multivariate analysis, only conversion to MMF was associated with a greater percent change in Cr from 6 to 18 months (P = 0.015). Conversion to MMF also correlated with higher GFR at 18 months independent of rejection, delayed graft function, and ethnicity. CONCLUSIONS: Conversion from TAC/SRL to TAC/MMF led to improved renal function despite increased TAC exposure after conversion.

Improving visibility depth in passive underwater imaging by use of polarization.

Results are presented that demonstrate the effectiveness of using polarization discrimination to improve visibility when imaging in a scattering medium. The study is motivated by the desire to improve visibility depth in turbid environments, such as the sea. Most previous research in this area has concentrated on the active illumination of objects with polarized light. We consider passive or ambient illumination, such as that deriving from sunlight or a cloudy sky. The basis for the improvements in visibility observed is that single scattering by small particles introduces a significant amount of polarization into light at scattering angles near 90 degrees: This light can then be distinguished from light scattered by an object that remains almost completely unpolarized. Results were obtained from a Monte Carlo simulation and from a small-scale experiment in which an object was immersed in a cell filled with polystyrene latex spheres suspended in water. In both cases, the results showed an improvement in contrast and visibility depth for obscuration that was due to Rayleigh particles, but less improvement was obtained for larger scatterers.