Remote profiling of lake ice thickness using a short pulse radar system aboard a C-47 aircraft

Design and operation of short pulse radar systems for use in ice thickness measurement are described. Two ice profiling systems were tested, an S system which used either random noise or continous wave modulation at 2.8 GHz and a less powerful C band system which operated at 6.0 GHz and did not have random noise modulation. Flight altitudes of 4,000 feet were used, but the S band system was usable at 7,000 feet allowing flights in poor weather conditions. A minimum ice thickness of four inches is required for measurement, while the thickest ice measured was 36 inches. System accuracy is plus or minus one inch

Leveraging YouTube for Storage Management and Accessibility

In an effort to improve the users’ experience when accessing our institutional repository, we decided to add closed captioning to all videos. We investigated a number of options such as local streaming servers and vended products, but could not find one that could meet our needs in terms of accessibility, compatibility with our repository platform, and easy of storage and management of videos. We then decided to test YouTube as a possible solution. We were pleased to learn that YouTube had auto closed captioning/transcription, a method of merging previously transcribed text with videos posted in YouTube, and an easy method to correct closed captions on the fly. YouTube also allows users to search the transcript and moves them to that point in the video. Overall, YouTube has improved both the usability and accessibility of our institutional repository

Flexible Material Systems Testing

An experimental program has been undertaken to better characterize the stress-strain characteristics of flexible material systems to support a NASA ground test program for inflatable decelerator material technology. A goal of the current study is to investigate experimental methods for the characterization of coated woven material stiffness. This type of experimental mechanics data would eventually be used to define the material inputs of fluid-structure interaction simulation models. The test methodologies chosen for this stress-strain characterization are presented along with the experimental results

Understanding and addressing institutionalized inequity: Disrupting pathways to juvenile justice for Black youth in Allegheny County

This report reveals that in Pittsburgh and Allegheny County, we are criminalizing our Black youth, manifested by disproportionately high arrest rates and referrals to juvenile justice. It presents information on two primary causes of the over-referral of Black youth to juvenile justice: 1) arrests and referrals made by school police and 2) summary citations. It concludes with recommendations for addressing these issues. As you read this report, keep in mind that the behavior of Black youth is not worse in Pittsburgh and Allegheny County than in other places and does not in any way account for these high levels of arrests, citations, and juvenile justice referrals. In fact, this report reveals that many of the behaviors for which our Black youth are arrested and cited are developmentally normal teenage behaviors for which White youth are rarely arrested and cited. This is a systems problem that demands reforms at the system level. It is incumbent on the adults running the systems criminalizing Black youth to address the systemic racism these patterns reveal

Characterization of Cre recombinase models for the study of adipose tissue

The study of adipose tissue in vivo has been significantly advanced through the use of genetic mouse models. While the aP2-CreBI and aP2-CreSalk lines have been widely used to target adipose tissue, the specificity of these lines for adipocytes has recently been questioned. Here we characterize Cre recombinase activity in multiple cell populations of the major adipose tissue depots of these and other Cre lines using the membrane-Tomato/membrane-GFP (mT/mG) dual fluorescent reporter. We find that the aP2-CreBI and aP2-CreSalk lines lack specificity for adipocytes within adipose tissue, and that the aP2-CreBI line does not efficiently target adipocytes in white adipose depots. Alternatively, the Adiponectin-CreERT line shows high efficiency and specificity for adipocytes, while the PdgfRα-CreERUCL and PdgfRα-CreERJHU lines do not efficiently target adipocyte precursor cells in the major adipose depots. Instead, we show that the PdgfRα-Cre line is preferable for studies targeting adipocyte precursor cells in vivo

A semi-analytical model to calculate energy production in single fracture geothermal reservoirs

The ultimate goal of geothermal reservoir management is to mine as much energy as possible from the reservoir. Since most of geothermal reservoirs are fractured, the development of improved techniques for monitoring, prediction and control of two-phase mass and energy transport in the fractures are needed. Tracer testing is a powerful tool for characterizing fractures properties such as swept pore volume. By incorporating the pore volume of the fracture estimated from tracer data with a semi-anaytical model of mass and energy transport in the fracture and matrix, the energy production rate can be calculated. Previous models to predict energey production assumed single-phase flow and semi-infinite matrix blocks and thus overestimate the energy that can be usufully produced from the reservoir. In this paper, a semi-analytical solution to the mass and energy balance equations is derived for two-phase flow in a fracture with heat conduction from a finite matrix. Calculations using the semi-analytical model are shown to be in good agreement with numerical simulations using the TETRAD simulator

Patterns of mtDNA Diversity in Northwestern North America

The mitochondrial DNA (mtDNA) haplogroups of 54 full-blooded modern and 64 ancient Native Americans from northwestern North America were determined. The control regions of 10 modern and 30 ancient individuals were sequenced and compared. Within the Northwest, the frequency distribution for haplogroup A is geographically structured, with haplogroup A decreasing with distance from the Pacific Coast. The haplogroup A distribution suggests that a prehistoric population intrusion from the subarctic and coastal region occurred on the Columbia Plateau in prehistoric times. Overall, the mtDNA pattern in the Northwest suggests significant amounts of gene flow among Northwest Coast, Columbia Plateau, and Great Basin populations

The bending of cell sheets - from folding to rolling

The bending of cell sheets plays a major role in multicellular embryonic morphogenesis. Recent advances are leading to a deeper understanding of how the biophysical properties and the force-producing behaviors of cells are regulated, and how these forces are integrated across cell sheets during bending. We review work that shows that the dynamic balance of apical versus basolateral cortical tension controls specific aspects of invagination of epithelial sheets, and recent evidence that tissue expansion by growth contributes to neural retinal invagination in a stem cell-derived, self-organizing system. Of special interest is the detailed analysis of the type B inversion in Volvox reported in BMC Biology by Höhn and Hallmann, as this is a system that promises to be particularly instructive in understanding morphogenesis of any monolayered spheroid system