854 research outputs found

    Construction and Calibration of a Streaked Optical Spectrometer for Shock Temperature

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    Here we describe the implementation and calibration of a streaked visible spectrometer (SVS) for optical pyrometry and emission/absorption spectroscopy on light gas gun platforms in the UC Davis Shock Compression Laboratory. The diagnostic consists of an optical streak camera coupled to a spectrometer to provide temporally and spectrally-resolved records of visible emission from dynamically-compressed materials. Fiber optic coupling to the sample enables a small diagnostic footprint on the target face and flexibility of operation on multiple launch systems without the need for open optics. We present the details of calibration (time, wavelength and spectral radiance) for absolute temperature determination and present benchmark measurements of system performance.Comment: 6 pages, 3 figures Davies, E., et al. (accepted). In J. Lane, T. Germann, and M. Armstrong (Eds.), 21st Biennial APS Conference on Shock Compression of Condensed Matter (SCCM19). AIP Publishin

    Exploring the Eating Disorder Examination Questionnaire, Clinical Impairment Assessment, and Autism Quotient to Identify Eating Disorder Vulnerability: A Cluster Analysis

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    Eating disorders are very complicated and many factors play a role in their manifestation. Furthermore, due to the variability in diagnosis and symptoms, treatment for an eating disorder is unique to the individual. As a result, there are numerous assessment tools available, which range from brief survey questionnaires to in-depth interviews conducted by a professional. One of the many benefits to using machine learning is that it offers new insight into datasets that researchers may not previously have, particularly when compared to traditional statistical methods. The aim of this paper was to employ k-means clustering to explore the Eating Disorder Examination Questionnaire, Clinical Impairment Assessment, and Autism Quotient scores. The goal is to identify prevalent cluster topologies in the data, using the truth data as a means to validate identified groupings. Our results show that a model with k = 2 performs the best and clustered the dataset in the most appropriate way. This matches our truth data group labels, and we calculated our modelā€™s accuracy at 78.125%, so we know that our model is working well. We see that the Eating Disorder Examination Questionnaire (EDE-Q) and Clinical Impairment Assessment (CIA) scores are, in fact, important discriminators of eating disorder behavior

    Comparative Analysis on the Susceptibility of Norway spruce (Picea abies) in Northern and Southern Finland to Heterobasidion parviporum Infection

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    Heterobasidion annosum s.l. is a devastating forest pathogen species complex which causes extensive damage to timber products in northern Europe. This study examined resistance of Norway spruce (Picea abies) in two field sites in Finland to annosum root rot (Heterobasidion parviporum) utilizing non-clonal stocks of P. abies. The northern field site in Rovaniemi does not have a historical presence of the pathogen, whereas the southern field site in LapinjƤrvi has extensive historical presence of the pathogen. The goals of the study were to assess potential difference in susceptibility between the sites, as well as to examine the differences in susceptibility between tissue types and organs in the trees examined. The study inoculated treatment trees with H. parviporum, as well as mock inoculations without the pathogen for control trees. Six inoculations of one treatment type were placed into each of thirty randomly selected trees at both field sites. Three inoculations were done in the stem, and three in the roots, for a total of 360 inoculations. After being left in situ for three months, the trees were harvested, and resulting lesions in the phloem and xylem tissues in both the roots and stem were measured to determine the extent of visible lesion extensions from the inoculation point. Data collected from the experiment was analyzed in the context of three mixed effects models, with the assumption that larger lesions indicated lower resistance to the pathogen. The measurements considered as response variables for the models were the total length of the lesion, total width of the lesion, and total area of the lesion. Results indicated minor overall differences in the lesion sizes between site in the lesion width and lesion area models. Significant differences were found between tissue types in the lesion width, and lesion area models. Additionally, interactions between treatment and organ, as well as treatment and tissue were significant across all models. Several other interactions were significant across some, but not all models The results indicate that further research into the potential effects of historical or geographic isolation on the resistance of P. abies to H. parviporum should include strict genetic controls with crossing of genotypes across sites, and should also consider the differences due to abiotic factors which may influence resistance in field trials

    Correspondence regarding 'Clouded leopards, the secretive top-carnivore of South-East Asian rainforests: their distribution, status and conservation needs in Sabah, Malaysia'

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    Correspondence regarding Wilting A, Fischer F, Bakar SA, Linsenmair KE: Clouded leopards, the secretive top-carnivore of South-East Asian rainforests: their distribution, status and conservation needs in Sabah, Malaysia. BMC Ecol 2006, 6:16

    Design and implementation of a supply chain management system at an emerging optical networking component supplier

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    Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002.Includes bibliographical references (p. 69).by Erik A. Stewart.S.M

    Consistent Paternity Skew through Ontogeny in Peron's Tree Frog (Litoria peronii)

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    BackgroundA large number of studies in postcopulatory sexual selection use paternity success as a proxy for fertilization success. However, selective mortality during embryonic development can lead to skews in paternity in situations of polyandry and sperm competition. Thus, when assessment of paternity fails to incorporate mortality skews during early ontogeny, this may interfere with correct interpretation of results and subsequent evolutionary inference. In a previous series of in vitro sperm competition experiments with amphibians (Litoria peronii), we showed skewed paternity patterns towards males more genetically similar to the female.Methodology/Principal FindingsHere we use in vitro fertilizations and sperm competition trials to test if this pattern of paternity of fully developed tadpoles reflects patterns of paternity at fertilization and if paternity skews changes during embryonic development. We show that there is no selective mortality through ontogeny and that patterns of paternity of hatched tadpoles reflects success of competing males in sperm competition at fertilization.Conclusions/SignificanceWhile this study shows that previous inferences of fertilization success from paternity data are valid for this species, rigorous testing of these assumptions is required to ensure that differential embryonic mortality does not confound estimations of true fertilization success.<br /

    Longitudinal changes in heart rate after participating in the Groningen Active Living Model (GALM) recreational sports programme

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    The aim of this study was to investigate changes in heart rate during submaximal exercise as an index of cardiovascular function in older adults participating in the Groningen Active Living Model recreational sports programme who were sedentary or underactive at baseline. A repeated measurement design was conducted; 151 participants were included, providing 398 heart rate files over a period of 18 months. Multi-level analyses were conducted; growth and final models were developed. Significant decreases in mean heart rate over time were observed for all walking speeds. The covariates of sex and body mass index (BMI) were significantly related to mean heart rate at each walking speed, except for BMI at 7 km/h. No significant relationships were observed between energy expenditure for recreational sports activities and leisure-time physical activities and mean heart rate, except for energy expenditure for leisure-time physical activities at 7 km/h. From baseline to December 2002, decreases in predicted mean heart rate were 5.5, 6.0, 10.0, and 9.0 beats/min at walking speeds of 4, 5, 6, and 7 km/h; relative decreases ranged from 5.1 to 7.4%. Significant decreases in heart rate observed during submaximal exercise reflected a potential increase in cardiovascular function after 18 months of participation in the Groningen Active Living Model recreational sports programme. DOI:10.1080/0264041090300874

    Arms and Armor of the Medieval Knight

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    The medieval knight was the deciding force on the battlefield during the Middle Ages, due primarily to his specialized arms and armor and his extensive training. This project tells the story of the knight through the arms and armor at his disposal. The team\u27s substantial research document on the knight\u27s historical context, weapons, armor, and equestrian equipment formed the basis of a 15-minute video documentary that will be shown hourly to the public at the Higgins Armory Museum
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