517 research outputs found

    Labor at home: The domestic world of workers at the Du Pont powder mills, 1802-1902

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    While the history of the du Pont family and Du Pont Company have been well-documented, little is known about the everyday lives of the Irish Catholic immigrants who lived and worked at the home plant near Wilmington, Delaware. to correct this oversight, Labor at Home explores every aspect of the powder workers\u27 domestic world--from religious beliefs, family structure, gender relations, and ethnic ties, to houses, furnishings, and yards--and uses this data to support new conclusions about cultural identity and class affiliation. as early as the 1820s, for example, powder mill families began to convey their increasing affiliation with bourgeois American society by amassing their savings, by selectively purchasing status-laden goods like tea sets and parlor furnishings, by acquiring property, by financing churches and schools, and by pursuing occupational and social mobility. Paradoxically, they also maintained certain beliefs and customs that proclaimed their identity as wage-earning Irish Catholics. Growing potatoes, drinking large quantities of whiskey, displaying crucifixes, and encouraging assertive female behavior perpetuated their unique ethno-religious heritage, yet these practices fueled the prejudices that confined the Irish to the lower ranks of society. Hence, this dissertation further demonstrates that status, identity, and consciousness are determined in complex and often contradictory ways

    Acute Appendicitis Review: Background, Epidemiology, Diagnosis, and Treatment.

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    Appendicitis is a common occurrence in both the adult and pediatric populations. The condition most commonly occurs between the ages of 10 and 20 years with a lifetime risk of 8.6% and 6.7% for males and females respectively. Its diagnosis focuses on clinical presentation and imaging modalities classified according to scoring systems such as the Alvarado scoring system. A number of imaging modalities can be used, with CT being the most common one. For acute appendicitis, surgical intervention is considered to be the gold standard of treatment. However, recent research has focused on other modalities of treatment including antibiotics and endoscopic retrograde appendicitis therapy (ERAT) to avoid surgical complications

    Mesalamine Associated Bradycardia.

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    A 38-year-old female presented with an acute flare of ulcerative colitis. She was started on prednisone and mesalamine. Within 24 hours of initiating mesalamine, she developed sinus bradycardia. After holding mesalamine, the heart rate returned to normal within five days. Our case illustrates the third described case, to our knowledge, of severe sinus bradycardia secondary to mesalamine

    Current and Near-Term Future Measurements of the Orbital Debris Environment at NASA

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    The NASA Orbital Debris Program Office places great emphasis on obtaining and understanding direct measurements of the orbital debris environment. The Orbital Debris Program Office's environmental models are all based on these measurements. Because OD measurements must cover a very wide range of sizes and altitudes, one technique realistically cannot be used for all measurements. In general, radar measurements have been used for lower altitudes and optical measurements for higher altitude orbits. For very small debris, in situ measurements such as returned spacecraft surfaces are utilized. In addition to receiving information from large debris (> 5-10 cm diameter) from the U.S. Space Surveillance Network, NASA conducts statistical measurements of the debris population for smaller sizes. NASA collects data from the Haystack and Goldstone radars for debris in low Earth orbit as small as 2- 4 mm diameter and from the Michigan Orbital DEbris Survey Telescope for debris near geosynchronous orbit altitude for sizes as small as 30-60 cm diameter. NASA is also currently examining the radiator panel of the Hubble Space Telescope Wide Field Planetary Camera 2 which was exposed to space for 16 years and was recently returned to Earth during the STS- 125 Space Shuttle mission. This paper will give an overview of these on-going measurement programs at NASA as well as discuss progress and plans for new instruments and techniques in the near future

    Orbital Debris Detection and Tracking Strategies for the NASA/AFRL Meter Class Autonomous Telescope (MCAT)

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    MCAT (Meter-Class Autonomous Telescope) is a 1.3m f/4 Ritchey-Chr tien on a double horseshoe equatorial mount that will be deployed in early 2011 to the western pacific island of Legan in the Kwajalein Atoll to perform orbital debris observations. MCAT will be capable of tracking earth orbital objects at all inclinations and at altitudes from 200 km to geosynchronous. MCAT s primary objective is the detection of new orbital debris in both low-inclination low-earth orbits (LEO) and at geosynchronous earth orbit (GEO). MCAT was thus designed with a fast focal ratio and a large unvignetted image circle able to accommodate a detector sized to yield a large field of view. The selected primary detector is a close-cycle cooled 4Kx4K 15um pixel CCD camera that yields a 0.9 degree diagonal field. For orbital debris detection in widely spaced angular rate regimes, the camera must offer low read-noise performance over a wide range of framing rates. MCAT s 4-port camera operates from 100 kHz to 1.5 MHz per port at 2 e- and 10 e- read noise respectively. This enables low-noise multi-second exposures for GEO observations as well as rapid (several frames per second) exposures for LEO. GEO observations will be performed using a counter-sidereal time delay integration (TDI) technique which NASA has used successfully in the past. For MCAT the GEO survey, detection, and follow-up prediction algorithms will be automated. These algorithms will be detailed herein. For LEO observations two methods will be employed. The first, Orbit Survey Mode (OSM), will scan specific orbital inclination and altitude regimes, detect new orbital debris objects against trailed background stars, and adjust the telescope track to follow the detected object. The second, Stare and Chase Mode (SCM), will perform a stare, then detect and track objects that enter the field of view which satisfy specific rate and brightness criteria. As with GEO, the LEO operational modes will be fully automated and will be described herein. The automation of photometric and astrometric processing (thus streamlining data collection for environmental modeling) will also be discussed

    Optical Measurement Center Status

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    Beginning in 2005, an optical measurement center (OMC) was created to measure the photometric signatures of debris pieces. Initially, the OMC was equipped with a 300 W xenon arc lamp, a SBIG 512 x 512 ST8X MEI CCD camera with standard Johnson filters, and a Lynx 6 robotic arm with five degrees of freedom. As research progressed, modifications were made to the equipment. A customized rotary table was built to overcome the robot s limitation of 180 degree wrist rotation and provide complete 360 degree rotation with little human interaction. This change allowed an initial phase angle (source-object-camera angle) of roughly 5 degrees to be adjusted to 7, 10, 15, 18, 20, 25, or 28 degrees. Additionally, the Johnson R and I CCD filters were replaced with the standard astronomical filters suite (Bessell R,I). In an effort to reduce object saturation, the two generic aperture stops were replaced with neutral density filters. Initially data were taken with aluminum debris pieces from the European Space Operations Centre ESOC2 ground test and more recently with samples from a thermal multi-layered insulation (MLI) commonly used on rocket bodies and satellites. The ESOC2 data provided light curve analysis for one type of material but many different shapes, including flat, bent, curled, folded, and torn. The MLI samples are roughly the same size and shape, but have different surfaces that give rise to interesting photometric light curves. In addition, filter photometry was conducted on the MLI pieces, a process that also will be used on the ESOC2 samples. While obtaining light curve data an anomalous drop in intensity was observed when the table revolved through the second 180 degree rotation. Investigation revealed that the robot s wrist rotation is not reliable past 80 degrees, thus the object may be at slightly different angles at the 180 degree transition. To limit this effect, the initial rotation position begins with the object s minimal surface area facing the camera

    Polycystic Liver With Cardiac Compression Leading to Atrial Fibrillation: Case Report and Review of the Literature.

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    Polycystic liver disease (PCLD) is a rare condition that most often occurs in patients with polycystic kidney disease and less commonly as an isolated liver disease. Complications include cyst rupture, infection, hemorrhage, and compression of surrounding organs by large cysts. We present the case of a patient with a history of PCLD who presented to our hospital with palpitations and was found to have atrial fibrillation. Imaging and echocardiograph revealed a dominant large cyst compressing the right atrium. Other etiologies including thyroid disease, ischemic heart disease, and electrolytes abnormalities were excluded. The patient refused surgical intervention and was conservatively treated with rate control and anticoagulation. To the best of our knowledge, this is the first case of new-onset atrial fibrillation secondary to right atrial compression by a liver cyst. Compression of cardiac chambers resulting in new-onset arrhythmia should be considered when evaluating patients with PCLD
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