The foreclosure crisis in 2008: predatory lending or household overreaching?

At least early in the financial crisis, the high rate of foreclosures seemed to be due more to households' overreaching than to predatory lending. A disproportionate number of those being foreclosed on were well-educated, well-off and relatively young people.Foreclosure ; Mortgage loans ; Housing - Finance

Investigation of dose perturbations and the radiographic visibility of potential fiducials for proton radiation therapy of the prostate

Image guidance using implanted fiducial markers is commonly used to ensure accurate and reproducible target positioning in radiation therapy for prostate cancer. The ideal fiducial marker is clearly visible in kV imaging, does not perturb the therapeutic dose in the target volume and does not cause any artifacts on the CT images used for treatment planning. As yet, ideal markers that fully meet all three of these criteria have not been reported. In this study, 12 fiducial markers were evaluated for their potential clinical utility in proton radiation therapy for prostate cancer. In order to identify the good candidates, each fiducial was imaged using a CT scanner as well as a kV imaging system. Additionally, the dose perturbation caused by each fiducial was quantified using radiochromic film and a clinical proton beam. Based on the results, three fiducials were identified as good candidates for use in proton radiotherapy of prostate cancer. © 2011 Institute of Physics and Engineering in Medicine

Ultra-short pulses in linear and nonlinear media

We consider the evolution of ultra-short optical pulses in linear and nonlinear media. For the linear case, we first show that the initial-boundary value problem for Maxwell's equations in which a pulse is injected into a quiescent medium at the left endpoint can be approximated by a linear wave equation which can then be further reduced to the linear short-pulse equation. A rigorous proof is given that the solution of the short pulse equation stays close to the solutions of the original wave equation over the time scales expected from the multiple scales derivation of the short pulse equation. For the nonlinear case we compare the predictions of the traditional nonlinear Schr\"odinger equation (NLSE) approximation which those of the short pulse equation (SPE). We show that both equations can be derived from Maxwell's equations using the renormalization group method, thus bringing out the contrasting scales. The numerical comparison of both equations to Maxwell's equations shows clearly that as the pulse length shortens, the NLSE approximation becomes steadily less accurate while the short pulse equation provides a better and better approximation

The Floor of Yellowstone Lake is Anything but Quiet—New Discoveries from High-Resolution Sonar Imaging, Seismic- Reflection Profiling, and Submersible Studies

Discoveries from multibeam sonar mapping and seis-mic-reflection surveys of Yellowstone Lake provide new insight into the recent geologic forces that have shaped a large lake at the active front of the Yellowstone hot spot, a region strongly affected by young (\u3c2 \u3em.y.), large-volume (\u3e100–1,000s km3) silicic volcanism, active tectonism, and accompanying uplift. Specifically, our mapping has identified the extent of postcaldera-collapse volcanism and active hydrothermal processes occurring above a large magma chamber beneath the lake floor. Multiple advances and recessions of thick glacial ice have overlapped volcanic and hydrothermal activity leaving a lake basin that has been shaped predominantly by fire and ice. Yellowstone Lake has an irregular bottom covered with dozens of features directly related to hydrothermal, tectonic, volcanic,and sedimentary processes. Detailed bathymetric, seismic-reflection, and magnetic evidence reveals that rhyolitic lava flows underlie much of Yellowstone Lake and exert fundamental control on lake morphology and localization of hydrothermal activity in the northern, West Thumb, and central basins. Many previously unknown features have been identified and include more than 660 hydrothermal vents, several very large (\u3e500-m diameter) hydrothermal-explosion craters, many small hydrothermal-vent craters (~1-to 200-m diameter), domed lacustrine sediments related to hydrothermal activity, elongate fissures cutting postglacial sediments, siliceous hydrothermal-spire structures, sublacustrine landslide deposits, submerged former shorelines, large glacial melting features, incipient faulting along the trace of the Eagle Bay fault zone, and a recently active graben. Sampling and observations with a submersible remotely operated vehicle confirm and extend our understanding of the identified features. Faults, fissures, hydrothermally inflated domal structures, hydrothermal-explosion craters, and sublacustrine landslides constitute potentially significant geologic hazards. Toxic elements derived from hydrothermal processes also may significantly affect the Yellowstone ecosystem

Associations among ancestry, geography and breast cancer incidence, mortality, and survival in Trinidad and Tobago

Breast cancer (BC) is the most common newly diagnosed cancer among women in Trinidad and Tobago (TT) and BC mortality rates are among the highest in the world. Globally, racial/ethnic trends in BC incidence, mortality and survival have been reported. However, such investigations have not been conducted in TT, which has been noted for its rich diversity. In this study, we investigated associations among ancestry, geography and BC incidence, mortality and survival in TT. Data on 3767 incident BC cases, reported to the National Cancer Registry of TT, from 1995 to 2007, were analyzed in this study. Women of African ancestry had significantly higher BC incidence and mortality rates (Incidence: 66.96; Mortality: 30.82 per 100,000) compared to women of East Indian (Incidence: 41.04, Mortality: 14.19 per 100,000) or mixed ancestry (Incidence: 36.72, Mortality: 13.80 per 100,000). Geographically, women residing in the North West Regional Health Authority (RHA) catchment area followed by the North Central RHA exhibited the highest incidence and mortality rates. Notable ancestral differences in survival were also observed. Women of East Indian and mixed ancestry experienced significantly longer survival than those of African ancestry. Differences in survival by geography were not observed. In TT, ancestry and geographical residence seem to be strong predictors of BC incidence and mortality rates. Additionally, disparities in survival by ancestry were found. These data should be considered in the design and implementation of strategies to reduce BC incidence and mortality rates in TT

The Floor of Yellowstone Lake is Anything but Quiet—New Discoveries from High-Resolution Sonar Imaging, Seismic- Reflection Profiling, and Submersible Studies

Discoveries from multibeam sonar mapping and seis-mic-reflection surveys of Yellowstone Lake provide new insight into the recent geologic forces that have shaped a large lake at the active front of the Yellowstone hot spot, a region strongly affected by young (\u3c2 \u3em.y.), large-volume (\u3e100–1,000s km3) silicic volcanism, active tectonism, and accompanying uplift. Specifically, our mapping has identified the extent of postcaldera-collapse volcanism and active hydrothermal processes occurring above a large magma chamber beneath the lake floor. Multiple advances and recessions of thick glacial ice have overlapped volcanic and hydrothermal activity leaving a lake basin that has been shaped predominantly by fire and ice. Yellowstone Lake has an irregular bottom covered with dozens of features directly related to hydrothermal, tectonic, volcanic,and sedimentary processes. Detailed bathymetric, seismic-reflection, and magnetic evidence reveals that rhyolitic lava flows underlie much of Yellowstone Lake and exert fundamental control on lake morphology and localization of hydrothermal activity in the northern, West Thumb, and central basins. Many previously unknown features have been identified and include more than 660 hydrothermal vents, several very large (\u3e500-m diameter) hydrothermal-explosion craters, many small hydrothermal-vent craters (~1-to 200-m diameter), domed lacustrine sediments related to hydrothermal activity, elongate fissures cutting postglacial sediments, siliceous hydrothermal-spire structures, sublacustrine landslide deposits, submerged former shorelines, large glacial melting features, incipient faulting along the trace of the Eagle Bay fault zone, and a recently active graben. Sampling and observations with a submersible remotely operated vehicle confirm and extend our understanding of the identified features. Faults, fissures, hydrothermally inflated domal structures, hydrothermal-explosion craters, and sublacustrine landslides constitute potentially significant geologic hazards. Toxic elements derived from hydrothermal processes also may significantly affect the Yellowstone ecosystem