14,668 research outputs found

    Dissolved Organic Matter Contains Previously Unidentified Protein-like Fluorophores in Old Woman Creek

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    Dissolved organic matter (DOM) constitutes a significant carbon pool in the global carbon cycle and is influential in many other processes e.g., altering the fate of contaminants, acting as redox and pH buffers, etc. The ubiquitous dispersal of DOM in the aqueous environment originates from sources ranging from autochthonous (microbial) to allochthonous (terrestrial) precursors. The source of the DOM dictates its composition, which in turn impacts its reactivity in the environment. The isolation of DOM from natural waters is a common practice to preserve and concentrate DOM, yet the extraction method may significantly alter its composition. This study explores the characteristics of DOM collected from Old Woman Creek (OWC) National Estuarine Research Reserve, located in Huron, Ohio, isolated using PPL solid phase extraction (SPE). Previous DOM extraction methods such as C-18 or XAD-8 are limited to hydrophobic compounds, while the novel PPL SPE cartridges capture more polar and non-polar components. PPL and previously collected XAD-8 isolated OWC DOM was characterized using fluorescence spectroscopy. Fluorescence analysis revealed protein-like components not present in previously collected XAD-8 isolated OWC DOM, demonstrating the significance of extraction method on the composition and potential reactivity of isolated DOM.Shell Oil CorporationNo embarg

    Food Assistant Programs’ Food Quality and The Risk of Developing Type II Diabetes in Native Americans

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    Abstract Background: A key factor behind the high rates of diabetes among Native Americans living in reservations is the high poverty rate. Though food assistance is provided on reservations to combat poverty and food insecurity, the rates of type II diabetes are still at an alarming high rate. Continuation of the alarming incidence of type II diabetes brings to question the nutritional quality of the food offered by food assistance programs. Objectives: The purpose of study was to examine food assistance programs utilized by Native Americans to determine if the food quality may have an impact on the risk of developing type II diabetes among Native Americans living on reservations in the United States. Methods: An integrative literature review was conducted to review literature articles published between 2007 and 2018 using scholarly databases: CINAHL, ProQuest Nursing, and PubMed. Keywords included: Native American, American Indian, diabetes, food assistance, and food assistance programs. The literature review method formed by Whittemore and Knafl (2005) was used for data reduction, and data analysis was guided by Tannehill’s model. Results: Findings indicated three aspects about the food from of food assistance programs in relation to the impact on the risk of developing type II diabetes in Native Americans. Those findings were that the food has low nutritional value, does not significantly alleviate food insecurity, and has become a large part of Native American diets. Conclusion: This integrative literature review found that the food quality of food assistance programs can indeed have an impact on the risk of developing of type II diabetes in Native Americans living on reservations. There is a visible need for health education and policy changes to achieve consistent access to healthier foods, which in turn can possibly decrease the risk of developing type II diabetes for many individuals living on reservations. Key words: Native American, American Indian, diabetes, food assistance, food assistance programs

    Behind the Steel Bars of History: The Post-Civil Rights Era Radical Prison Movement

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    The resistance and political action taken by the incarcerated in prisons like Attica Correctional Facility during the post-civil rights era (1968 -1972) faced an unprecedented state-led, counterinsurgent force. The socio-historical context of this suppression is a time of crisis for the U.S. as it struggled to maintain capitalist hegemony in the face of anti-systemic movements from the New Left. The post-civil rights era was a moment in US history that saw the strongest and most radical challenge to racial capitalism to date in the form of a social movement led by prisoners, yet the historical legacy of radical prison organizing continues to be suppressed because the state treated the politics and tactics the incarcerated mobilized behind as a threat to the massive securitization strategy and neoliberal capitalist reconfiguration of the 1970s. I first compare the popular retelling of the civil rights movement as compared to the radical prison movement (in media, education, and collective memory) and then analyze the Attica Manifesto and Soledad Brother by George Jackson to understand the contents of radical prison politics and its subsequent suppression. Coming to understand the potential of the incarcerated as a source of a powerful anti-capitalist politic requires us to dispel the idea that history is a form of truth-telling. History is a form of state-mediated collective memory, rather than a “truth,” that justifies the state’s agenda of securitization in the interest of protecting capital

    Between Encounter and Experience: Florida in the Cuban Imagination

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    The antecedents of the relationship between Florida and Cuba reach deeply into the sixteenth century, almost with the inception of European colonization. The peninsula loomed large in the imagination of the island. The enduring facets of this connection assumed discernable patterns early, principally in the form of successive waves of migration northward, spanning centuries, first by such personalities as Panfilo Narvaez and Hernando de Soto and most recently Elian Gonzilez. It is perhaps worth recalling that there was a time when Florida was once a dependency of Cuba, populated and subsidized from the island

    Bandwidth efficient CCSDS coding standard proposals

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    The basic concatenated coding system for the space telemetry channel consists of a Reed-Solomon (RS) outer code, a symbol interleaver/deinterleaver, and a bandwidth efficient trellis inner code. A block diagram of this configuration is shown. The system may operate with or without the outer code and interleaver. In this recommendation, the outer code remains the (255,223) RS code over GF(2 exp 8) with an error correcting capability of t = 16 eight bit symbols. This code's excellent performance and the existence of fast, cost effective, decoders justify its continued use. The purpose of the interleaver/deinterleaver is to distribute burst errors out of the inner decoder over multiple codewords of the outer code. This utilizes the error correcting capability of the outer code more efficiently and reduces the probability of an RS decoder failure. Since the space telemetry channel is not considered bursty, the required interleaving depth is primarily a function of the inner decoding method. A diagram of an interleaver with depth 4 that is compatible with the (255,223) RS code is shown. Specific interleaver requirements are discussed after the inner code recommendations

    Interior noise in military helicopters

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    The Temporary Threshold Shift (TTS) or temporary hearing loss caused by excessive interior noise in military helicopters results in a critical degradation of the acoustically unprotected infantryman\u27s ability to detect the existence or the approach of the enemy by hearing under combat conditions. The overall problem of noise reduction in helicopters consists of: (1) identifying the various noise sources, and (2) employing appropriate noise control techniques. Identification of the source is accomplished by the frequency correlation of 1/10-octave band analysis of the interior sound levels measured within the helicopter cabin with near-field sound generated by the sound sources. Reduction of the overall interior helicopter noise can be accomplished by attenuation or interdiction along the noise \u27\u27path , and/or by redesign of the source to reduce the sound generated in the first place. In the case of the helicopter, attenuation or interdiction of the noise consists of: (1) padding or insulating the source with lightweight absorption materials, (2) vibration isolation of the source, and/or (3) the wearing of ear protection by the passengers. This study proposes the installation of lightweight leaded vinyl sheet as an interior measure until redesign can be accomplished to permit adequate vibration isolation. Ear protection is recommended for all crew and passengers, but it is realized that cost and storage space may be prohibitive --Abstract, page ii

    Sulphur abundance determinations in star-forming regions-I: Ionization Correction Factor

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    In the present work we used a grid of photoionization models combined with stellar population synthesis models to derive reliable Ionization Correction Factors (ICFs) for the sulphur in star-forming regions. These models cover a large range of nebular parameters and yielding ionic abundances in consonance with those derived through optical and infrared observational data of star-forming regions. From our theoretical ICFs, we suggested an {\alpha} value of 3.27 in the classical Stasinska formulae. We compared the total sulphur abundance in the gas phase of a large sample of objects by using our Theoretical ICF and other approaches. In average, the differences between the determinations via the use of the different ICFs considered are similar to the uncertainties in the S/H estimations. Nevertheless, we noted that for some objects it could reach up to about 0.3 dex for the low metallicity regime. Despite of the large scatter of the points, we found a trend of S/O ratio to decrease with the metallicity, independently of the ICF used to compute the sulphur total abundance.Comment: Accepted for publication in MNRAS, 21 pages, 8 figures, 5 table

    Detection Of Fracture Orientation Using Azimuthal Variation Of P-Wave Avo Responses

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    Azimuthally-dependent P-wave AVO (amplitude variation with offset) responses can be related to open fracture orientation and have been suggested as a geophysical tool to identify fracture orientation in fractured oil and gas reservoirs. A field experiment recently conducted over a fractured reservoir in the Barinas Basin (Venezuela) provides data for an excellent test of this approach. Three lines of data were collected in three different azimuths, and three component receivers were used. The distribution of fractures in this reservoir was previously obtained using measurements of shear wave splitting from P-S converted waves from the same dataset (Ata and Michelena, 1995). In this work, we use P-wave data to see if the data can yield the same information using azimuthal variation of P-wave AVO responses. Results obtained from the azimuthal P-wave AVO analysis corroborate the results previously obtained using P-S converted waves. This analysis with field data is an example of the high potential of P-waves to detect fracture effects on seismic wave propagation.Massachusetts Institute of Technology. Earth Resources Laboratory. Reservoir Delineation Consortiu
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