3,622 research outputs found

    High Resolution Spectrometry of Leaf and Canopy Chemistry for Biochemical Cycling

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    High-resolution laboratory spectrophotometer and Airborne Imaging Spectrometer (AIS) data were used to analyze forest leaf and canopy chemistry. Fundamental stretching frequencies of organic bonds in the visible, near infrared and short-wave infrared are indicative of concentrations and total content of nitrogen, phosphorous, starch and sugar. Laboratory spectrophotometer measurements showed very strong negative correlations with nitrogen (measured using wet chemistry) in the visible wavelengths. Strong correlations with green wet canopy weight in the atmospheric water absorption windows were observed in the AIS data. A fairly strong negative correlation between the AIS data at 1500 nm and total nitrogen and nitrogen concentration was evident. This relationship corresponds very closely to protein absorption features near 1500 nm

    Faith, Race-Ethnicity, and Public Policy Preferences: Religious Schemas and Abortion Attitudes among U.S. Latinos

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    Research has demonstrated that white conservative Protestants are more opposed to abortion than their Catholic counterparts. At the same time, conservative Protestantism has made significant inroads among U.S. Latinos. This study augments existing research on religion and racial-ethnic variations in abortion attitudes by comparing levels of support for legalized abortion among Catholic and conservative Protestant Latinos. Data are drawn from a nationally representative sample of U.S. Latinos. Significantly greater opposition to abortion is found among religiously devout conservative Protestant Latinos when compared with their Catholic counterparts. Latino Catholicism, which functions as a near-monopolistic, highly institutionalized faith tradition among Hispanics, produces weaker antiabortion attitudes than those exhibited in Latino conservative Protestantism. Among Latinos, conservative Protestantism operates as a niche voluntaristic faith. These factors produce a religious schema that yields robust antiabortion attitudes. This study has important implications for understanding the intersection of race-ethnicity, religion, and public policy preferences

    The “tragic” story of the conquest in books and printed papers of men of letters in the independent provinces of New Granada, 1811-1821

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    Este artículo estudia las producciones literarias de los hombres de letras en las provincias independientes de la Nueva Granada entre 1811-1821. Se muestra cómo durante ese período, al tiempo que se producían los procesos de emancipación y posteriormente la fundación de la República, esos actores sociales (sacerdotes, impresores, abogados y gentes de letras) empezaron a participar de manera crítica en la vieja discusión y polémica sobre la presencia de España en América desde el siglo XVI. Ello dio como resultado la aparición de varias versiones sobre el pasado y de la escritura de la historia referida a la conquista del territorio americano en la que se destacaban “los trescientos años de vejaciones”, la “opresión”, la “tiranía” y las “conductas inocuas de los españoles”. Escritura que respondía al compromiso asumido por los letrados de justificar la independencia y más tarde la República de Colombia. Lo que ponía así en evidencia la relación siempre existente de las narrativas y usos del pasado con los contextos políticos de una sociedad.This article studies the literary productions of the men of letters in the independent provinces of New Granada between 1811-1821. The aim is to show how these social actors (priests, printers, lawyers and literary people) began to participate critically in the old discussion during that period, at the same time as the emancipation processes and later the founding of the Republic. And controversy about the presence of Spain in America since the sixteenth century. This resulted in the appearance of several versions on the past and the writing of the history referred to the conquest of the American territory in which “the three hundred years of vexations”, “oppression”, “tyranny” and “Innocuous conduct of the Spaniards.” Writing that responded to the commitment assumed by lawyers to justify independence and later the Republic of Colombia. This made evident the ever-existing relationship of the narratives and uses of the past with the political contexts of a society

    Gateway Modeling and Simulation Plan

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    This plan institutes direction across the Gateway Program and the Element Projects to ensure that Cross Program M&S are produced in a manner that (1) generate the artifacts required for NASA-STD-7009 compliance, (2) ensures interoperability of M&S exchanged and integrated across the program and, (3) drives integrated development efforts to provide cross-domain integrated simulation of the Gateway elements, space environment, and operational scenarios. This direction is flowed down via contractual enforcement to prime contractors and includes both the GMS requirements specified in this plan and the NASASTD- 7009 derived requirements necessary for compliance. Grounding principles for management of Gateway Models and Simulations (M&S) are derived from the Columbia Accident Investigation Board (CAIB) report and the Diaz team report, A Renewed Commitment to Excellence. As an outcome of these reports, and in response to Action 4 of the Diaz team report, the NASA Standard for Models and Simulations, NASA-STD-7009 was developed. The standard establishes M&S requirements for development and use activities to ensure proper capture and communication of M&S pedigree and credibility information to Gateway program decision makers. Through the course of the Gateway program life cycle M&S will be heavily relied upon to conduct analysis, test products, support operations activities, enable informed decision making and ultimately to certify the Gateway with an acceptable level of risk to crew and mission. To reduce risk associated with M&S influenced decisions, this plan applies the NASA-STD-7009 requirements to produce the artifacts that support credibility assessments and ensure the information is communicated to program management

    Studies on the clinical significance of nonesterified and total cholesterol in urine

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    Gas-liquid chromatographic determinations of nonesterified and total urinary cholesterol were performed in 137 normals, 264 patients with various internal diseases without evidence of neoplasias or diseases of the kidney or urinary tract, 497 patients with malignancies and 236 patients with diseases of the kidney, urinary tract infections or prostatic adenoma with residual urine. A normal range (mean±2 SD) of 0.2–2.2 mg/24 hours nonesterified cholesterol (NEC) and of 0.3–3.0 mg/24 hours total cholesterol (TC) was calculated. Values of urinary cholesterol excretion were independent of age and sex and did not correlate with cholesterol levels in plasma. Patients with various internal diseases, without evidence of neoplasias nor diseases of the kidney or obstruction of the urinary tract, showed normal urinary cholesterol excretions, as did patients with infections of the urinary tract. However, elevated urinary cholesterol was found in patients with diseases of the kidney or urinary tract obstruction (prostatic adenoma with residual urine), malignant diseases of the urogenital tract and metastasing carcinoma of the breast. In patients with other malignant diseases urinary cholesterol was usually normal. Lesions of the urothelial cell membranes are considered to be the most likely cause of urinary cholesterol hyperexcretion. The clinical value of urinary cholesterol determinations as a possible screening test for urogenital carcinomas in unselected populations is limited by lacking specificity, expensive methodology and low prevalence of the mentioned carcinomas, although elevated urinary cholesterol excretions have been observed in early clinical stages of urogenital cancers

    Directed Chaotic Transport in Hamiltonian Ratchets

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    We present a comprehensive account of directed transport in one-dimensional Hamiltonian systems with spatial and temporal periodicity. They can be considered as Hamiltonian ratchets in the sense that ensembles of particles can show directed ballistic transport in the absence of an average force. We discuss general conditions for such directed transport, like a mixed classical phase space, and elucidate a sum rule that relates the contributions of different phase-space components to transport with each other. We show that regular ratchet transport can be directed against an external potential gradient while chaotic ballistic transport is restricted to unbiased systems. For quantized Hamiltonian ratchets we study transport in terms of the evolution of wave packets and derive a semiclassical expression for the distribution of level velocities which encode the quantum transport in the Floquet band spectra. We discuss the role of dynamical tunneling between transporting islands and the chaotic sea and the breakdown of transport in quantum ratchets with broken spatial periodicity.Comment: 22 page

    Previsión de las necesidades y disponibilidades de Ingenieros de Chile

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    Geotechnical Units and the Damages Caused by Earthquakes in Valparaiso - Chile

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    The geotechnical units forming the foundation soil of Valparaiso city and constituting seven zones that exhibit different stratigraphic sequences are characterized. In addition, the evolution of the artificial backfilling’s located in the seaport is reported. The damages causes by Chile Earthquake of March 3, 1985 allow to establish for each zone the MSK intensities, which are varying between 7 1/2 and 8 1/2 in the flat-ground sector of Valparaiso, and between 7 1/4 and 7 1/2 in the hills. The major intensity in the flat sector is observed in areas whose artificial backfilling’s are exhibiting greater thickness and less consistency or less compacity
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