1,732 research outputs found

    Modeling Aircraft Takeoffs

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    Real-world applications can demonstrate how mathematical models describe and provide insight into familiar physical systems. In this paper, we apply techniques from a first-semester differential equations course that shed light on a problem from aviation. In particular, we construct several differential equations that model the distance that an aircraft requires to become airborne. A popular thumb rule that pilots have used for decades appears to emanate from one of these models. We will see that this rule does not follow from a representative model and suggest a better method of ensuring safety during takeoff. Aircraft safety is definitely a matter of public concern, although it is the FAA (Federal Aviation Administration) that makes the regulations

    Editorial

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    Cellular and Secretory Proteins of the Salivary Glands of \u3cem\u3eSciara coprophila\u3c/em\u3e During the Larval-pupal Transformation

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    The cellular and secretory proteins of the salivary gland of Sciara coprophila during the stages of the larval-pupal transformation were examined by electrophoresis in 0.6 mm sheets of polyacrylamide gel with both SDS-continuous and discontinuous buffer systems. After SDS-electrophoresis, all electrophoretograms of both reduced and nonreduced proteins from single glands stained with Coomassie brilliant blue revealed a pattern containing the same 25 bands during the stages of the larval-pupal transformation. With the staining procedures used in this study, qualitative increases and decreases were detected in existing proteins and enzymes. There was no evidence, however, for the appearance of new protein species that could be correlated with the onset of either pupation or gland histolysis. Electrophoretograms of reduced samples of anterior versus posterior gland parts indicated that no protein in the basic pattern of 25 bands was unique to either the anterior or posterior gland part. Electrophoretograms of reduced samples of secretion collected from either actively feeding or cocoon -building animals showed an electrophoretic pattern containing up to six of the 25 protein fractions detected in salivary gland samples, with varied amounts of these same six proteins in electrophoretograms of secretion samples from a given stage. Zymograms of non-specific esterases in salivary gland samples revealed a progressive increase in the amount of esterase reaction produce in one major band and some decrease in the second major band during later stages of the larval-pupal transformation

    Health Concerns in Argentina

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    Development and characterization of SSR markers for Trichloris crinita using sequence data from related grass species = Desarrollo y caracterización de marcadores moleculares SSR para Trichloris crinita usando secuencias de gramíneas filogenéticamente cercanas

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    Trichloris crinita is among the most important native forage grasses in arid regions of America. Despite its importance, molecular resources and sequence data are extremely scarce in this species. In the present study, SSR markers were developed using available DNA sequences from grass taxa phylogenetically-related to Trichloris (Eleusine coracana, Cynodon dactylon and ‘Cynodon dactylon x Cynodon transvaalensis’). Marker transferability was evaluated in a panel of eight T. crinita accessions and five closely-related species. Of the 105 SSR primer pairs evaluated, 16 amplified products of expected size in T. crinita, whereas transferability to other grass species ranged from 12 (in Chloris castilloniana) to 28 SSRs (in Eleusine coracana). Six of the 16 SSR markers successfully transferred to T. crinita (37.5%) were polymorphic, and were further used to assess genetic diversity in eight T. crinita accessions. The analysis revealed a total of 23 SSR alleles (3.83 alleles/locus), allowing the discrimination of all T. crinita accessions, with pair-wise genetic similarities ranging from 0.35 to 0.81 (Jaccard coefficient). Mean (and range) values for observed (Ho) and expected heterozygosity (He) were 0.53 (0.0-1.0) and 0.63 (0.48-0.79), respectively.Trichloris crinita es una importante gramínea forrajera, nativa de regiones áridas del continente americano. A pesar de su importancia, no existen herramientas moleculares ni secuencias nucleotídicas disponibles para esta especie. En este estudio, se desarrollaron marcadores moleculares SSR (“simple sequence repeats”) a partir de secuencias nucleotídicas de especies filogenéticamente cercanas a Trichloris (Eleusine coracana, Cynodon dactylon y ‘Cynodon dactylon x Cynodon transvaalensis’) y se evaluó su transferibilidad en ocho accesiones de T. crinita y cinco especies de gramíneas cercanamente emparentadas. De los 105 pares de cebadores evaluados, 16 amplificaron productos del tamaño esperado en T. crinita, mientras que la transferibilidad a otras especies varió entre 12 (en Chloris castilloniana) y 28 SSRs (en Eleusine coracana). De los 16 SSRs transferibles a T. crinita, seis fueron polimórficos y se utilizaron para analizar el grado de diversidad genética en ocho accesiones de esta especie. El análisis reveló 23 alelos, los cuales permitieron diferenciar todas las accesiones de T. crinita, con valores de similitud genética entre pares de accesiones de 0,35 a 0,81 (Jaccard). Se obtuvieron valores medios de heterocigosidad observada y esperada de 0,53 y 0,63 respectivamente.EEA La ConsultaFil: Kozub, Perla Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Barboza Rojas, Karina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Cavagnaro, Juan Bruno. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Cavagnaro, Pablo Federico. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentin

    Desarrollo y caracterización de marcadores moleculares SSR para Trichloris crinita usando secuencias de gramíneas filogenéticamente cercanas

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    Trichloris crinita is among the most important native forage grasses in arid regions of America. Despite its importance, molecular resources and sequence data are extremely scarce in this species. In the present study, SSR markers were developed using available DNA sequences from grass taxa phylogenetically-related to Trichloris (Eleusine coracana, Cynodon dactylon and ‘Cynodon dactylon x Cynodon transvaalensis’). Marker transferability was evaluated in a panel of eight T. crinita accessions and five closely-related species. Of the 105 SSR primer pairs evaluated, 16 amplified products of expected size in T. crinita, whereas transferability to other grass species ranged from 12 (in Chloris castilloniana) to 28 SSRs (in Eleusine coracana). Six of the 16 SSR markers successfully transferred to T. crinita (37.5%) were polymorphic, and were further used to assess genetic diversity in eight T. crinita accessions. The analysis revealed a total of 23 SSR alleles (3.83 alleles/locus), allowing the discrimination of all T. crinita accessions, with pair-wise genetic similarities ranging from 0.35 to 0.81 (Jaccard coefficient). Mean (and range) values for observed (Ho) and expected heterozygosity (He) were 0.53 (0.0-1.0) and 0.63 (0.48-0.79), respectively.Trichloris crinita es una importante gramínea forrajera, nativa de regiones áridas del continente americano. A pesar de su importancia, no existen herramientas moleculares ni secuencias nucleotídicas disponibles para esta especie. En este estudio, se desarrollaron marcadores moleculares SSR (“simple sequence repeats") a partir de secuencias nucleotídicas de especies filogenéticamente cercanas a Trichloris (Eleusine coracana, Cynodon dactylon y ‘Cynodon dactylon x Cynodon transvaalensis’) y se evaluó su transferibilidad en ocho accesiones de T. crinita y cinco especies de gramíneas cercanamente emparentadas. De los 105 pares de cebadores evaluados, 16 amplificaron productos del tamaño esperado en T. crinita, mientras que la transferibilidad a otras especies varió entre 12 (en Chloris castilloniana) y 28 SSRs (en Eleusine coracana). De los 16 SSRs transferibles a T. crinita, seis fueron polimórficos y se utilizaron para analizar el grado de diversidad genética en ocho accesiones de esta especie. El análisis reveló 23 alelos, los cuales permitieron diferenciar todas las accesiones de T. crinita, con valores de similitud genética entre pares de accesiones de 0,35 a 0,81 (Jaccard). Se obtuvieron valores medios de heterocigosidad observada y esperada de 0,53 y 0,63 respectivamente.Fil: Kozub, Perla Carolina. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Barboza, Karina. CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas) - Universidad Nacional de CuyoFil: Cavagnaro, Juan Bruno. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Cavagnaro, Pablo Federico. CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas) - Universidad Nacional de Cuy

    MS 243 Guide to the Louise Cavagnaro Papers (1948-1992)

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    This collection consists of photographs, clippings, publications, a thesis review, and correspondence relating to the Atomic Bomb Casualty Commission (ABCC). Most of the materials date from 1948 to 1962, although some items are undated. Cavagnaro\u27s review of War Guilt and Medical Research is from 1992. Collection materials generally originated in Japan or discuss conditions there. See more at MS 243
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