1,090 research outputs found
Interview with Grace Ederer
No full textGrace Ederer was born on June 27, 1919 in southwestern, rural Minnesota. She attended the College of St. Catherine in Saint Paul Minnesota, majoring in biology and graduating with a BS in 1941. From 1941 to 1942, Ederer attended the School of Medical Technology in Detroit, Michigan, part of Detroit’s Providence Hospital. She then worked in chemistry a chemistry laboratory at the Henry Ford Hospital for two years. As part of the war effort, she returned to the College of St. Catherine to teach chemistry lab courses to cadet nurses. Through a family friend, Ederer heard about an opportunity at Northwestern Hospital, which later merged with Abbott, to build up a microbiology lab. Ederer pursued the job and spent the next twelve years at Northwestern Hospital building a reputable microbiology lab. Tiring of her Bunsen burner, Ederer joined the University of Minnesota in the University Hospital as an administrator of the clinical laboratories, a position she held from 1952 to 1963. During her time at the University, Ederer earned her masters in public health in 1962. After spending fifteen years as administrator of clinical laboratories, she took a new position as assistant to the director of clinical laboratories in the microbiology area of the Division of Medical Technology and became an assistant professor. She became an associate professor in 1967, serving in that position until her retirement in 1982.Grace Ederer begins her interview with a description of her upbringing, her education, and her decision to enter the field of medical technology. She then recalls the early stages of her career and her work at the University of Minnesota from 1952 to 1982. Ederer describes the role of women in medical technology, the building of the new medical sciences building, and Dr. Gerald T. Evans’ efforts to reorganize the clinical laboratories and medical technology to integrate them into the Medical School. Ederer also discusses her decision to adopt a dog that had been used in experiments conducted C. Walton Lillehei on hypothermia in open-heart surgery. She goes on to describe her changing positions at the University, her teaching, her research, and her pursuit of a master’s in public health. She also talks about her interactions with Dr. Evans, Dr. Ellis Benson, and Dr. Lillehei. She then discusses the Medical Technology Program, her work with Barbara Tucker on laboratory safety and ethics, her work with Ruth Hovde and Verna Rausch, the changing curriculum, dealing with the high volume of lab work, working with graduate students, her experiences with Robert Howard, and efforts to establish a school of Allied Health Sciences.Hagens, Emily; Ederer, Grace M.. (2012). Interview with Grace Ederer. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/142749
Grace Aguilar’s historical romances
No full textPhDMy dissertation looks critically at Grace Aguilar’s historical romance novels and short
stories, and investigates English writers’ uses of history in early- to mid-nineteenth century
fiction. Shifting the current critical emphasis on Aguilar’s Jewish texts, I
have analyzed the ways in which Aguilar revises the genres of the national tale, the
gothic romance, and the medieval romance in order to demonstrate her participation
in the construction of nineteenth-century domestic values.
In Chapter One, I introduce to critical debate Aguilar’s juvenilia, relying on
unpublished manuscripts and novels published only in the twentieth century to
establish the origins of Aguilar’s interest in history and historical writing. Locating
Aguilar’s narrative style in the early nineteenth-century national tale, I show that as a
child Aguilar envisioned the English and Scottish nations as a family, making
domesticity both a private and a public—a female and a male—value.
Chapter Two focuses on Aguilar’s use of history to express nineteenth-century
domestic ideals in her version of the gothic romance. Deploying the setting of the
Catholic Inquisition in Spain and Portugal, Aguilar writes gothic tales that unite
Jewish and Protestant gender values. She makes heroic the Jewish female martyr to
suggest not only that nineteenth-century Protestants and Jews share similar domestic
principles, but also that Jewish women could be seen as ideal models for Protestant
women.
Finally, in Chapter Three I explore Aguilar’s participation in the nineteenth-century
medievalist tradition by reflecting on her revision of nineteenth-century literary
idealizations of the Middle Ages. In these short stories, Aguilar fictionalizes the
sixteenth-century European chivalric ethos, looking critically at the role of women in
court society at the end of the Middle Ages. Deploying the tropes prevalent in
popular nineteenth-century anti-medievalist fiction, Aguilar debunks celebrations of
the Middle Ages by showing how chivalry is antagonistic to nineteenth-century
domesticity
Topside Ionosphere Sounding From the CHAMP, GRACE, and GRACE-FO Missions
No full textSatellites in Low Earth Orbit (LEO) are essential for sounding the topside ionosphere. In this work, we present and validate a data set of Total Electron Content (TEC) and in situ electron density observations from the Gravity Recovery And Climate Experiment (GRACE) and GRACE-Follow-On missions as well as a TEC data set from the CHAllenging Minisatellite Payload mission. Concerning TEC, special emphasis is put to ensure optimal consistency to the already existing Swarm and Gravity field and steady-state ocean circulation explorer (GOCE) TEC data sets. The newly processed satellite missions allow covering two full solar cycles with LEO slant TEC. Furthermore, the twin satellite missions GRACE and GRACE-FO equipped with inter-satellite K-band ranging allows to derive the horizontal TEC and, due to the small inter-satellite distance of the satellite pairs, an approximation for local electron density. However, the derived value of electron density is relative and requires calibration using external information. In this work, the calibration is performed using the IRI-2016 model. Radar observations, as well as in situ electron density observations available from Swarm B Langmuir probes, are used for validation. Conjunctions between satellites are used to validate the TEC time series. The newly derived data set is shown to be highly consistent with the already existing data sets with standard deviations below 3 TECU for TEC (even 1 TECU was reached for low solar flux) and an offset below 7 × 1010 m−3 with a standard deviation near 1 × 1011 m−3 for the electron density.</p
New thermosphere neutral mass density and crosswind datasets from CHAMP, GRACE, and GRACE-FO
No full textWe present new neutral mass density and crosswind observations for the CHAMP, GRACE, and GRACE-FO missions, filling the last gaps in our database of accelerometer-derived thermosphere observations. For consistency, we processed the data over the entire lifetime of these missions, noting that the results for GRACE in 2011–2017 and GRACE-FO are entirely new. All accelerometer data are newly calibrated. We modeled the temperature-induced bias variations for the GRACE accelerometer data to counter the detrimental effects of the accelerometer thermal control deactivation in April 2011. Further, we developed a new radiation pressure model, which uses ray tracing to account for shadowing and multiple reflections and calculates the satellite’s thermal emissions based on the illumination history. The advances in calibration and radiation pressure modeling are essential when the radiation pressure acceleration is significant compared to the aerodynamic one above 450 km altitude during low solar activity, where the GRACE and GRACE-FO satellites spent a considerable fraction of their mission lifetime. The mean of the new density observations changes only marginally, but their standard deviation shows a substantial reduction compared to thermosphere models, up to 15% for GRACE in 2009. The mean and standard deviation of the new GRACE-FO density observations are in good agreement with the GRACE observations. The GRACE and CHAMP crosswind observations agree well with the physics-based TIE-GCM winds, particularly the polar wind patterns. The mean observed crosswind is a few tens of m · s−1 larger than the model one, which we attribute primarily to the crosswind errors being positive by the definition of the retrieval algorithm. The correlation between observed and model crosswind is about 60%, except for GRACE in 2004–2011 when the signal was too small to retrieve crosswinds reliably
Jews and gender in British literature 1815-1865.
No full textPhDThis thesis examines the variety of relationships between Jews and gender in early
to mid-nineteenth century British literature, focussing particularly on representations
of and by Jewish women. It reconstructs the social, political and literary context in
which writers produced images and narratives about Jews, and considers to what
extent stereotypes were reproduced, appropriated, or challenged. In particular it
examines the ways in which questions of gender were linked to ideas about religious
or racial difference in the Victorian period.
The study situates literary representations of Jews within the context of
contemporary debates about the participation of the Jews in the life of the modern
state. It also investigates the ways in which these political debates were gendered,
looking in particular at the relationship between the cultural construction of
femininity and English national identity.
It first considers Victorian culture's obsession with Rebecca, the Jewess created in
Walter Scott's influential novel Ivanhoe (1819). It examines Rebecca's refusal to
convert to Christianity in the context of Scott's discussion of racial separatism and
modern national unity.
Evangelical writers like Annie Webb, Amelia Bristow and Mrs Brendlah were
prolific literary producers, and preoccupied with converting Jewish women.
Particularly during the 18'40s and 1850s, evangelical writing provided an important
forum for the construction and consolidation of women's national identity.
Grace Aguilar's writing was an attempt to understand Jewish identity within the
terms of Victorian domestic ideology. In contrast, Celia and Marion Moss, in their
historical romances, offered narratives of female heroism and national liberation,
drawing on the contemporary debate about slavery.
Benjamin Disraeli's construction of a "tough version of Jewish identity was a
response both to the contemporary stereotype of the feminised Jew and to the debate
about Jewish emancipation. It also drew on the virile ideology of the Young England
movement of the 1840s
Accurate and efficient orbit prediction through improved drag force modelling of GRACE and PROBA-V satellites
No full textIn recent years, with the increasing number of man made objects in space the need for accurate satellite orbit prediction has increased tremendously. Prediction of satellite trajectories is important to plan collision avoidance manoeuvres between space assets and debris, to autonomously maintain formation flying missions and to plan manoeuvres for ground-track maintenance of Earth-observation missions. For satellites in very low LEO, aerodynamic drag is the largest and the most difficult force to model because of the changing nature of atmospheric density. This report describes the efforts made towards improving the orbit prediction of SAOCOM-CS with a focus on drag force modelling. This is accomplished by orbit determination using GPS state vector measurements and precise deterministic force models, during periods of high and low solar activity. Drag scale factors are estimated with different resolutions. Different methods are used to choose the estimated drag scale factors for orbit prediction. GRACE-A and PROBA-V satellites are used as test cases. For a prediction arc length of one day, the best prediction strategy results in maximum position errors (3D) of 243.5 m and 24.1 m for GRACE-A \& PROBA-V, respectively during high solar activity. Based on the prediction results of GRACE-A \& PROBA-V, a rule of thumb analysis is used to derive the maximum position error in the orbit prediction of SAOCOM-CS, which lies between 40 and 75 m. Changes in the mean estimated drag scale factors of the satellites are observed between high and low solar activity which might indicate deficiencies in the NRLMSISE-00 density model. The report also provides the effect of the space weather forecast errors on the best prediction strategy. Introducing a 10 \% error in the solar activity index resulted in mean maximum along-track prediction errors of 393 m and 16 m for GRACE-A \& PROBA-V, respectively during high solar activity. Similarly, including random errors in the geomagnetic activity index resulted in mean maximum along-track prediction errors of 443 m and 15 m for GRACE-A \& PROBA-V, respectively during high solar activity. Finally, the optimization of the estimation and prediction methods for the computational efficiency of PROBA-V is presented. A six hour estimation arc length with the force model comprising Earth gravity field of degree and order 30 of the model ITU\_GRACE 16 with luni-solar perturbations and devoid of atmospheric drag, solar radiation pressure and tidal forces is the most computationally efficient combination for a prediction arc length of one day.Aerospace Engineerin
Regularizing GRACE mascon solutions using river run-off data
No full textAccurate estimates of terrestrial water storage variations (TWSV) are critical for a variety of applications, e.g., model calibration and climate studies. This study aims to find the added value of river run-off data for regularizing GRACE mascon solution, from which TWSV can be estimated. Most subbasins of the Mississippi Basin show an exponential relationship between run-off and TWSV with moderate to good predictive value. The mean value of the explained variance (R^2) for the models is 0.4, when excluding the Lower Mississippi and Middle Missouri subbasins the mean value increases to 0.5. The Lower Mississippi and Middle Missouri subbasins are the only subbasins with no clear correlation between run-off and storage, most likely due to aquifer depletion. Since ready-to-used GRACE mascon solutions cannot be modified, the mascon method developed at the Geoscience and Remote Sensing Department of the Delft University of Technology is used in this study. This study proposes modifications to tailor this method to the Mississippi Basin and mass anomalies of hydrological origin. After applying standard Tikhonov regularization, the exponential relationship is used to determine the most probable model outcome for each subbasin, adding a new term to the estimator. The resulting GRACE mascon solutions (Tikhonov and run-off regularized solutions) have a root-mean-square deviation (RMSD) of around 3.5 cm when compared to ready-to-use mascon solutions from the Jet Propulsion Laboratory and Goddard Space Flight Center. The run-off regularized solutions show smaller deviation (on average 7 %) than the Tikhonov regularized solutions with respect to an independent validation data set. The largest difference between the Tikhonov and run-off regularized solutions occur in the dryer subbasins (Platte, Middle, and Upper Missouri, and Upper Mississippi subbasin). These areas show a stronger inter-annual trend in TWSV, these trends are captured better by the run-off regularized solutions. Additional research, co-estimating the regularization bias, shows that the run-off regularized solutions induce less bias into the solutions. This study shows that using run-off data when processing GRACE data could be of added value, especially in semi-humid to arid areas, since the TWSV in these areas is more susceptible to inter-annual variations.Geoscience and Remote Sensin
The quality of GRACE monthly solutions and potential improvements by the use of the Global Tide and Surge Model
No full textClimate change causes alterations in large scale mass transport patterns in the ocean, cryosphere and hydrology. The Gravity Recovery and Climate Experiment (GRACE) satellite mission which has been operational in the years 2002-2017 has already improved our understanding of large scale mass transport on Earth, but improvement of data quality is still needed. This will increase the quality of our current estimates of the effects of climate change on one hand and help in the validation and initiation of climate models on the other, which improves the accuracy of future predictions.Noise in GRACE Level-2 data (monthly gravity field solutions) is caused by various reasons. The measurements themselves are already executed and their quality is fixed but better data processing algorithms and background models can reduce the current noise level. This is also relevant for the GRACE Follow On mission which might have a higher measurement precision. Over the ocean, these GRACE monthly solutions ideally only show mass exchange between continents and ocean and effects of self-attraction and loading. Therefore, the signal over the ocean is expected to consist predominantly of a linear trend and a seasonal variability. For certain oceanic regions this is not the case. In these areas still a signal variance representing interannual differences in the mass-derivative and large residuals with respect to a low-pass filtered signal are observed. This low-pass filtered signal contains only signals of a frequency lower than the semiannual cycle. These signal variance and residuals are unexpected and can be caused by inaccuracies in the currently applied oceanic background models in GRACE data processing. For various Release 5 and Release 6 monthly solutions the noise variance, signal variance and residuals as aforementioned are estimated. The noise and signal variance are estimated by Variance Component Estimation (VCE). Additionally, numerical experiments are performed to analyze different regularization functionals and set-ups in the VCE. The oceanic regions where the largest signal variance and residuals are observed correlate. These areas are for GRACE Release 5 data the Baltic Sea, Black Sea, Arafura Sea, East Siberian Arctic Shelf, Argentine Basin and Hudson Bay. For GRACE Release 6 data a significant drop of this signal variance and residuals can be observed for the Hudson Bay and East Siberian Arctic Shelf.Consequently, the oceanic background models for these releases are compared against each other and against the Global Tide and Surge Model (GTSM) which is a 2D hydrological model based on the Delft3D Flexible Mesh software developed by Deltares. For the whole ocean both 3/6-hourly time-series and monthly time-series are analyzed. For the shallow regions up to 200 m, the Black Sea and the Red Sea, GTSM shows significant differences with respect to the current applied oceanic background models. When comparing the oceanic background models of different releases it can be observed that the regions where the signal variance and residuals decreased for GRACE Release 6 with respect to Release 5 correlate to regions where the differences between these models is significant. This indicates that oceanic background models do significantly influence the quality of GRACE monthly solutions over the ocean. Furthermore, it is investigated whether it can be expected that GTSM will improve the GRACE monthly solutions. For this, monthly time-series of the current applied oceanic background models are added back to the GRACE monthly solutions; consequently, by GTSM computed monthly time-series are removed. Compared to GRACE Release 5 monthly solutions, GTSM shows a reduction in the signal variance and residuals for the Hudson Bay, East Siberian Arctic Shelf, Black Sea, Baltic Sea, North Sea, Arafura Sea and certain parts of the Arctic and Southern ocean. Compared to GRACE Release 6, a reduction in the signal variance and residuals is observed for the East Siberian Arctic Shelf, Black Sea, Baltic Sea, North Sea and Arafura Sea. For these regions it is most expected that GTSM can improve GRACE monthly solutions. Since the quality of monthly solutions over the oceans is clearly influenced by the oceanic background models significant alterations in GRACE monthly solutions are expected for the shallow regions up to 200 m, Black Sea and Red Sea when applying GTSM in the GRACE data processing. Whether these will be improvements or not should be analyzed by implementing GTSM-based 3-hourly time-series in the GRACE data processing to create a new GRACE Level-2 data product
The Divine Invitation: An Examination of the Philosophies of Grace in the Writing of J.R.R. Tolkien, Flannery O'Connor, and Walker Percy
No full textProgram year: 1992/1993Digitized from print original stored in HDRThis study, then, will examine each of these authors in his or her utilization of Augustinian or Thomistic grace as they attempt to reach an audience deaf to the conventional words of the Gospel. It will also examine the dominant motif for grace that each author chooses to use, in keeping with the theology of grace present in that piece. In the case of J.R.R. Tolkien's Lord of the Rings trilogy, the dominant symbol of grace is that of a gift. As mentioned previously, Walker Percy presents grace in the lives of his characters as a cure for their malaise of modernity in the novels The Moviegoer and The Thanatos Syndrome. The short stories of Flannery O'Connor's anthology A Good Man is Hard to Find consistently present grace as a sudden flash of truth to a character veiled in a world of dark illusions
Regional high-resolution spatiotemporal gravity modeling from GRACE data using spherical wavelets
No full textWe determine a regional spatiotemporal gravity field over northern South America including the Amazon region using GRACE inter-satellite range-rate measurements by application of a wavelet-based multiresolution technique. A major advantage of this method is that we are able to represent the Amazon hydrological signals in form of time series of detail signals with level-dependent temporal resolution: the coarser structures generally require only ten days, whereas the medium and finer details are computable from one month of data. To this end, we employ the basic property of multiresolution representations, which is to split a signal into detail signals, each related to a specific resolution level and computable from data covering a specific part of the spectrum. Our results, which for the first time fully exploit the spatial and temporal resolutions of GRACE data in modeling Amazon hydrological fluxes, are in good agreement with hydrological models and GPS-derived height variations.Earth Observation and Space SystemsAerospace Engineerin
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