Effectiveness evaluation of STOL transport operations

A short-takeoff and landing (STOL) systems simulation model has been developed and implemented in a computer code (known as STOL OPS) which permits evaluation of the operation of a STOL aircraft and its avionics in a commercial airline operating environment. STOL OPS concentrated on the avionics functions of navigation, guidance, control, communication, hazard aviodance, and systems management. External world factors influencing the operation of the STOL aircraft include each airport and its geometry, air traffic at each airport, air traffic control equipment and procedures, weather (including winds and visibility), and the flight path between each airport served by the route. The development of the STOL OPS program provides NASA a set of computer programs which can be used for detailed analysis of a STOL aircraft and its avionics and permit establishment of system requirements as a function of airline mission performance goals

Variabilidade genética em populações naturais de umbuzeiro (Spondias tuberosa Arr. Cam.) com base em dados isoenzimáticos.

Este trabalho teve como objetivo quantificar a variabilidade genética em duas populações naturais de umbuzeiro (fruteira endêmica do semi-árido nordestino) e sua distribuição entre e dentro das populações, de forma a fornecer dados que direcionem a coleta de germoplasma para conservação e melhoramento genético da espécie

Effect of prolonged ingestion of polychlorinated biphenyls on the rat

On a fair consommer a des rats, pendant 2, 4 et 6 mois et a raison de 0,5 et 25 ppm de leur regime alimentaire,de l'Aroclor 1242, melange commercial de biphenyles polychlores. Des augmentations significatives de l'excretion urinaire de coproporphyrine, des lipides hepatiques et de l'activite de l'hydroxylase microsomique hepatique ont ete observees chez les animaux qui avaient consomme 25 ppm pendant 2 mois. L'excretion urinaire de coproporphyrine, le poids du foie, sa teneur en lipides et l'activite de son hydroxylase microsomique etaient plus eleves chez les rats soumis pendant 4 ou 6 mois aux regimes a 5 ou a 25 ppm que chez les animaux temoins. A l'examen histopathologique on a constate une vacuolation des lipides et une proliferation de reticulum endoplasmique dans les hepatocytes des animaux traites. Ces constatations signifient que l'ingestion prolongee de faibles doses d'Aroclor 1242 peut modifier un certain nombre de parametres biologiques.AbstractAroclor 1242, a commercial polychlorinated biphenyl mixture, was fed to rats at dietary levels of 0, 5 and 25 ppm for 2, 4 and 6 months. Significant elevations of urinary coproporphyrin excretion, hepatic lipid and hepatic microsomal-hydroxylase activity were observed in rats ingesting 25 ppm for 2 months. In rats given the 5 or 25 ppm regimens for 4 or 6 months, urinary coproporphyrin excretion and liver weight, lipid content and microsomal-hydroxylase activity were higher than in controls. Histopathological examination revealed lipid vacuolation and proliferation of smooth endoplasmic reticulum in the hepatocytes of treated animals. These findings indicate that long-term, low-level ingestion of Aroclor 1242 may result in changes in a variety of biological parameters.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22345/1/0000791.pd

Finding and counting vertex-colored subtrees

The problems studied in this article originate from the Graph Motif problem introduced by Lacroix et al. in the context of biological networks. The problem is to decide if a vertex-colored graph has a connected subgraph whose colors equal a given multiset of colors $M$. It is a graph pattern-matching problem variant, where the structure of the occurrence of the pattern is not of interest but the only requirement is the connectedness. Using an algebraic framework recently introduced by Koutis et al., we obtain new FPT algorithms for Graph Motif and variants, with improved running times. We also obtain results on the counting versions of this problem, proving that the counting problem is FPT if M is a set, but becomes W[1]-hard if M is a multiset with two colors. Finally, we present an experimental evaluation of this approach on real datasets, showing that its performance compares favorably with existing software.Comment: Conference version in International Symposium on Mathematical Foundations of Computer Science (MFCS), Brno : Czech Republic (2010) Journal Version in Algorithmic

Biological responses of the rat to polychlorinated biphenyls

A commercial polychlorinated biphenyl mixture (PCBs), Aroclor 1242, was administered to rats po by intubation in order to determine toxic manifestations of acute and subacute ingestion. In addition, the effect of PCBs on hepatic microsomal enzyme systems in rats was evaluated. The oral, 14-day LD50 was determined to be approximately 4.25 g/kg. Major toxic signs observed upon administration of high doses of PCBs included diarrhea, chromodacryorrhea, loss of body weight, unusual stance and gait, lack of response to pain stimuli, and terminal ataxia. Progressive dehydration and CNS depression appeared to be contributing factors in each fatality. Histopathologic alterations were evident only in the liver and kidneys, manifest as foci of sudanophilic vacuolation. Rats maintained on an oral dosage regimen of 100 mg/kg every other day for 3 weeks exhibited similar histopathologic changes, but no overt signs of toxicity. Serum GOT activities were elevated over controls in both the acute and subacute groups. A single ip injection (100 mg/kg) increased liver weight, total hepatic microsomal enzyme activity (measured as hydroxylation of acetanilide and N-demethylation of aminopyrine), and hepatic cytochrome P450 and b5 levels. Hepatic microsomal enzyme activity remained elevated 10 days after a single dose of PCBs, suggesting that PCBs may play an important role in altering biologic responses of mammals subjected to environmental chemical stress.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33934/1/0000201.pd

Diversidade genética entre progênies de maracujazeiro amarelo baseado em características morfo agronômicas.

O estudo da diversidade genética é básico para subsidiar a escolha de genitores e trabalhos de seleção e melhoramento. Este trabalho foi realizado no Departamento de Fitotecnia da Universidade Federal de Viçosa. Avaliouse a diversidade genética entre 34 famílias de meios-irmãos e 3 cultivares de maracujazeiro amarelo. O delineamento experimental foi em blocos casualizados, com 37 tratamentos, três repetições e quatro plantas por parcela. As características avaliadas foram: altura da planta e diâmetro do caule aos 60 dias após o transplantio, diâmetro do caule no início da produção, vigor, severidade de verrugose e produção por parcela. Os dados foram submetidos à análise de variância e as médias comparadas pelo método de Dunnett. Para o estudo da diversidade genética, foram estimadas as distâncias de Mahalanobis (D2) entre progênies, bem como realizadas análises de agrupamento de Tocher e das Variáveis Canônicas. Por meio da análise de variância, verificou-se efeito dos tratamentos em todas as variáveis, evidenciando a existência de variabilidade genética entre as progênies e cultivares avaliados. Houve concordância na formação dos grupos de similaridade por meio dos diferentes métodos de análise multivariada. Os grupos de tratamentos divergentes entre si e superiores foram: Grupo I - 2, 3, 6 e 15; Grupo II - 14; e Grupo III - 25