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Search Results: 1 - 10 of 481638 matches for " Cristine L. S. Morgan "
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Vibration-Induced Conductivity Fluctuation (VICOF) Testing of Soils
Laszlo B. Kish,Cristine L. S. Morgan,Andrea Sz. Kishne
Physics , 2005, DOI: 10.1142/S0219477506003501
Abstract: In this Letter, we propose and experimentally demonstrate a simple method to provide additional in-formation by conductivity measurements of soils. The AC electrical conductance of the soil is measured while it is exposed to a periodic vibration. The vibration-induced density fluctuation implies a corresponding conductivity fluctuation that can be seen as combination frequency components, the sum and the difference of the mean AC frequency and the double of vibration frequency, in the current response. The method is demonstrated by measurements on clayey and sandy soils.
Vibration-Induced Conductivity Fluctuation Measurement for Soil Bulk Density Analysis
Andrea Sz. Kishne,Cristine L. S. Morgan,Hung-Chih Chang,Laszlo B. Kish
Physics , 2007, DOI: 10.1117/12.724667
Abstract: Soil bulk density affects water storage, water and nutrient movement, and plant root activity in the soil profile. Its measurement is difficult in field conditions. Vibration-induced conductivity fluctuation was investigated to quantify soil bulk density with possible field applications in the future. The AC electrical conductivity of soil was measured using a pair of blade-like electrodes while exposing the soil to periodic vibration. The blades were positioned longitudinally and transversally to the direction of the induced vibration to enable the calculation of a normalized index. The normalized index was expected to provide data independent from the vibration strength and to reduce the effect of soil salinity and water content. The experiment was conducted on natural and salinized fine sand at two moisture conditions and four bulk densities. The blade-shaped electrodes improved electrode-soil contact compared to cylindrical electrodes, and thereby, reduced measurement noise. Simulations on a simplified resistor lattice indicate that the transversal effect increases as soil bulk density decreases. Measurement of dry sand showed a negative correlation between the normalized conductivity fluctuation and soil bulk density for both longitudinal and transversal settings. The decrease in the transversal signal was smaller than expected. The wet natural and salinized soils performed very similarly as hypothesized, but their normalized VICOF response was not significant to bulk density changes.
Beat Cepheid Period Ratios from OPAL Opacities
S. M. Morgan,D. L. Welch
Physics , 1996, DOI: 10.1086/118550
Abstract: The discovery of a large number of beat Cepheids in the Large Magellanic Cloud in the MACHO survey, provides an opportunity to compare the characteristics of such Cepheids over a range of metallicities. We produced a large grid of linear nonadiabatic pulsation models using the OPAL opacity tables and with compositions corresponding to those of the Milky Way, and the Large and Small Magellanic Clouds. Using the relationship between the period ratio and the main pulsation period, we are able to define a range of models which correspond to the observed beat Cepheids, and thereby constrain the physical characteristics of the LMC beat Cepheids. We are also able to make some predictions about the nature of the yet-to-be-discovered SMC beat Cepheids.
Key Reduction of McEliece's Cryptosystem Using List Decoding
Morgan Barbier,Barreto S. L. M. Paulo
Mathematics , 2011,
Abstract: Different variants of the code-based McEliece cryptosystem were pro- posed to reduce the size of the public key. All these variants use very structured codes, which open the door to new attacks exploiting the underlying structure. In this paper, we show that the dyadic variant can be designed to resist all known attacks. In light of a new study on list decoding algorithms for binary Goppa codes, we explain how to increase the security level for given public keysizes. Using the state-of-the-art list decoding algorithm instead of unique decoding, we exhibit a keysize gain of about 4% for the standard McEliece cryptosystem and up to 21% for the adjusted dyadic variant.
Spatial Variation in Abundance, Size and Orientation of Juvenile Corals Related to the Biomass of Parrotfishes on the Great Barrier Reef, Australia
Melanie L. Trapon, Morgan S. Pratchett, Andrew S. Hoey
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0057788
Abstract: For species with complex life histories such as scleractinian corals, processes occurring early in life can greatly influence the number of individuals entering the adult population. A plethora of studies have examined settlement patterns of coral larvae, mostly on artificial substrata, and the composition of adult corals across multiple spatial and temporal scales. However, relatively few studies have examined the spatial distribution of small (≤50 mm diameter) sexually immature corals on natural reef substrata. We, therefore, quantified the variation in the abundance, composition and size of juvenile corals (≤50 mm diameter) among 27 sites, nine reefs, and three latitudes spanning over 1000 km on Australia’s Great Barrier Reef. Overall, 2801 juveniles were recorded with a mean density of 6.9 (±0.3 SE) ind.m?2, with Acropora, Pocillopora, and Porites accounting for 84.1% of all juvenile corals surveyed. Size-class structure, orientation on the substrate and taxonomic composition of juvenile corals varied significantly among latitudinal sectors. The abundance of juvenile corals varied both within (6–13 ind.m?2) and among reefs (2.8–11.1 ind.m?2) but was fairly similar among latitudes (6.1–8.2 ind.m?2), despite marked latitudinal variation in larval supply and settlement rates previously found at this scale. Furthermore, the density of juvenile corals was negatively correlated with the biomass of scraping and excavating parrotfishes across all sites, revealing a potentially important role of parrotfishes in determining distribution patterns of juvenile corals on the Great Barrier Reef. While numerous studies have advocated the importance of parrotfishes for clearing space on the substrate to facilitate coral settlement, our results suggest that at high biomass they may have a detrimental effect on juvenile coral assemblages. There is, however, a clear need to directly quantify rates of mortality and growth of juvenile corals to understand the relative importance of these mechanisms in shaping juvenile, and consequently adult, coral assemblages.
Escalas psicométricas como instrumentos de rastreamento para depress?o em estudantes do ensino médio
Salle, Emilio;Rocha, Neusa S.;Rocha, Taís S.;Nunes, Cristine;Chaves, Márcia L. F.;
Revista de Psiquiatria Clínica , 2012, DOI: 10.1590/S0101-60832012000100005
Abstract: background: depression is a major cause of suicide among adolescents. therefore, it is crucial to find suitable depression screening tools for this population. objective: to evaluate the use of depression rating scales as screening tools for depression in a sample of brazilian high school students. methods: a cross-sectional study. three scales (bdi, ces-d, and crs) and a screening test for general psychiatric symptoms (srq) were administered to a sample of 503 high school students aged between 15 to 17 years. the results were compared to those obtained with the diagnostic and statistical manual of mental disorders (dsm-iv). results: the prevalence of major depression using dsm-iv criteria was 10.9%. adolescents with major depression had significantly higher (p = 0.001) scores in the srq and in the three scales analyzed compared to the group without depression. the sensitivity and specificity of bdi, ces-d, and crs were 0.77 and 0.70, 0.75 and 0.73, and 0.82 and 0.71, respectively, to screen for major depression (roc curve). the best cutoff values to suggest depression were 9 for bdi, 10 for csr, and 14 for ces-d. the frequency of depressive symptoms was higher in girls (approximately 2:1). discussion: the present findings support the use of the bdi, the ces-d and the crs only for screening or as an additional symptomatic evaluation of depression in high school student. the difference in scale scores between boys and girls warns against the use of the same cutoff values for both sexes.
Comparative Effects of Different Disturbances in Coral Reef Habitats in Moorea, French Polynesia
Mélanie L. Trapon,Morgan S. Pratchett,Lucie Penin
Journal of Marine Biology , 2011, DOI: 10.1155/2011/807625
Abstract: Degradation and loss of critical coastal habitats has significant ramifications for marine fisheries, such that knowledge of changes in habitat quality and quantity are fundamental to effective ecosystem management. This study explores changes in the structure of coral reef habitats, specifically changes in coral cover and composition, in Moorea, French Polynesia, to assess the independent and combined effects of different disturbances since 1979. During this period, reefs on the north coast have been subject to coral bleaching, severe tropical storms, as well as outbreaks of Acanthaster. Coral cover varied significantly among years, showing marked declines during some, but not all, disturbances. The greatest rates of coral loss coincided with outbreaks of A. planci. Moreover, successive disturbances have had differential effects among coral genera, leading to strong directional shifts in coral composition. Acropora is declining in abundance and coral assemblages are becoming increasingly dominated by Pocillopora and Porites. Observed changes in the cover and composition of corals are likely to have further significant impacts on the reef fish assemblages. Given that significant disturbances have been mostly associated with outbreaks of A. planci, rather than climate change, effective ecosystem management may reduce and/or delay impending effects of climate change. 1. Introduction Disturbances play an important role in the structure and dynamics of marine communities and are a necessary part of ecosystem dynamics [1–4]. On coral reefs, moderate levels of disturbance make an important contribution to increasing biodiversity [5]. In many locations, however, natural acute “pulse” disturbances have combined with chronic “press” [6] anthropogenic stresses (e.g., overfishing, pollution and eutrophication) to cause excessive disturbance and degradation of coral reef environments [7, 8]. On a global scale, it is estimated that 30% of coral reefs have now lost >90% of reef-building corals and there is little to no prospect of recovery [9]. Moreover, 60% of coral reefs around the world may face a similar fate by 2030 [9, 10]. The loss of reef-building corals is likely to have major impacts on the biodiversity, productivity, and biological functioning of coral reef ecosystems [11, 12]. In some locations, changes in the structure and quality of benthic reef habitats are now the most important driver of changes in the abundance of reef fishes (including some large piscivorous species), having a greater influence than extractive fisheries [13, 14]. Major contributors
Observational study of sites of triggered star formation: CO and mid-infrared observations
J. S. Urquhart,L. K. Morgan,M. A. Thompson
Physics , 2009, DOI: 10.1051/0004-6361/200811149
Abstract: (Abridged) Bright-rimmed clouds (BRCs) are isolated molecular clouds located on the edges of evolved HII regions where star formation is thought may have been triggered. In this paper we investigate the current level of star formation within a sample of BRCs and evaluate to what extent star formation may have been induced. We present the results of a programme of position-switched CO observations towards 45 southern BRCs. The 12CO, 13CO and C18O (J=1-0) were simultaneously observed using the 22m Mopra telescope. We complement these observations with archival mid-IR submm and radio data. Analysis of the CO, mid-IR and radio data result in the clouds being divided into three distinct groups. We refer to these groups as spontaneous, triggered, and zapped clouds, respectively. Comparing the physical parameters of spontaneous and triggered samples we find striking differences in luminosity, surface temperature and column density with all three quantities significantly enhanced for the clouds considered to have been triggered. Furthermore, we find strong evidence for star formation within the triggered sample by way of methanol and H_2O masers, embedded mid-IR point sources and CO wings, however, we find evidence of ongoing star formation within only two of the spontaneous sample. We have used CO, mid-IR and radio data to identify 24 of the 45 southern BRCs that are undergoing a strong interaction with their HII region. We can therefore exclude ~50% from future studies. 14 of the 24 interacting BRCs are found to be associated with embedded mid-IR point sources and we find strong evidence of that these clouds are forming stars. The absence of mid-infrared sources towards the remaining ten clouds leads us to conclude that these represent an earlier evolutionary stage of star formation.
Human ration does not alter weight and body composition, but improves the lipid profile of overweight woman Ración humana no modifica el peso ni la composición corporal pero mejora el perfil lipídico de mujeres con sobrepeso
J. L. Marques Rocha,P. Cristine Anuncia??o,M. G. Vaz Tostes,S. Thomas Valdés
Nutrición Hospitalaria , 2012,
Abstract: Background: In Brazil, a mixture of cereals known as "Human Ration" (HR) has been consumed as a substitute for meals due to effects in satiation and weight loss. Methods: This paper evaluated the effect of HR consumption for 45 days as a breakfast replacement, on body composition, biochemical profile and eating behavior in women (n = 20) between 18-45 years old and with BMI between 27-35 kg/m2. Results: The intake of HR did not promote significant changes in the body composition as well as in the mean serum values of glucose, HDL, VLDL, TC/HDL, AST and ALT. However, a significant change was noticed in the levels of TC, LDL and triglycerides (p < 0.05). Average daily intake of calories and macronutrients of the volunteers during the period of HR consumption did not differ from their habitual ingestion (p > 0.05). Regarding the consumption of total fibers, there was a significant increase (p < 0.05) in intake at breakfast during the period of HR consumption when compared to the usual intake. The consumption of HR did not intervene in the sensations of satiation, hunger and prospective intake among the subjects, presenting only instantaneous significant alterations throughout the study. Conclusion: The results are clinically relevant, since they may contribute to the reduction of risk factors for chronic noncommunicable diseases. Introducción: En Brasil, una mezcla de cereales conocidos como "Ra o Humana" (HR) se ha consumido como sustituto de las comidas debido a los efectos en la saciedad y en la pérdida de peso. Métodos: Se evaluó el efecto del consumo de HR durante 45 días, sustituyendo el desayuno, en la composición corporal, perfil bioquímico y en la conducta alimentaria en mujeres (n = 20) entre 18-45 a os de edad y con IMC entre 27-35 kg/m2. Resultados: La ingesta de HR no promovió cambios significativos en la composición corporal, así como en los valores medios de glucosa, colesterol HDL, VLDL, CT/HDL, AST y ALT en el suero. Sin embargo, se observaron cambios significativos en las concentraciones de CT, LDL y los triglicéridos (p < 0,05). La ingesta media diaria de calorias y macronutrientes de los voluntarios durante el periodo de consumo de HR no difirieron de su ingesta habitual (p > 0,05). Respecto al consumo de fibras total, se observó un aumento significativo sólo para el desayuno (p < 0,05) en el periodo de consumo de HR en comparación con la ingesta habitual. El consumo de la HR no intervino en las sensaciones de saciedad, en el hambre y en la ingesta prospectiva entre los sujetos, presentando solamente alteraciones significativas durante
O posicionamento do enfermeiro frente à autonomia do paciente terminal
Oliveira, Aline Cristine de;Sá, Lílian;Silva, Maria Júlia Paes da;
Revista Brasileira de Enfermagem , 2007, DOI: 10.1590/S0034-71672007000300007
Abstract: this research attends an study with qualitative aproach. its aim were to analyze the nursing concept of autonomy of terminal patients, their attitude face an autonomy of terminal patient demostration and what is the nurse perspective in the presence of autonomy while has being structure in brazil. this study was fulfilled in palliative care unit of hospital of clinics of uberlandia. for nurses to perceive autonomy as na ethic beginninig of the existence, is a way to change the knowledge, which turns clear the necessity of exchanges in schools to helpthe services conduct the health team, their problems, their conflicts when patient's autonomy does not agree with values believed by the health team.
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