Modeling Selective Availability of the NAVSTAR Global Positioning System

As the development of the NAVSTAR Global Positioning System (GPS) continues, there will increasingly be the need for a software centered signal model. This model must accurately generate the observed pseudorange which would typically be encountered. The observed pseudorange varies from the true geometric (slant) range due to range measurement errors. Errors in range measurement stem from a variety of hardware and environment factors. These errors are classified as either deterministic or random and, where appropriate, their models are summarized. Of particular interest is the model for Selective Availability which is derived from actual GPS data. The procedure for the determination of this model, known as the System Identification Theory, is briefly outlined. The synthesis of these error sources into the final signal model is given along with simulation results

GPS interferometric attitude and heading determination: Initial flight test results

Attitude and heading determination using GPS interferometry is a well-understood concept. However, efforts have been concentrated mainly in the development of robust algorithms and applications for low dynamic, rigid platforms (e.g., shipboard). This paper presents results of what is believed by the authors to be the first realtime flight test of a GPS attitude and heading determination system. The system is installed in Ohio University's Douglas DC-3 research aircraft. Signals from four antennas are processed by an Ashtech 3DF 24-channel GPS receiver. Data from the receiver are sent to a microcomputer for storage and further computations. Attitude and heading data are sent to a second computer for display on a software generated artificial horizon. Demonstration of this technique proves its candidacy for augmentation of aircraft state estimation for flight control and navigation as well as for numerous other applications

On the genus Bursaphelenchus Fuchs, 1937 (Nematoda: Parasitaphelenchinae) associated with wood and insects from declining forest trees in the Czech Republic

An overview of the genus Bursaphelenchus in the Czech Republic is presented, based on a recent survey for monitoring the presence of the pinewood nematode, Bursaphelenchus xylophilus, as well as on previous reports of this genus in the country. In addition, we provide a morphological and molecular characterization of four Bursaphelenchus species (B. eremus, B. pinophilus, B. vallesianus and B. borealis) found during the monitoring programme for forest pests, conducted during 2006–2010, within the Moravian and Bohemian regions. Nematodes were extracted from over 1917 insects and 1493 wood samples collected from deciduous and coniferous trees exhibiting wilting and declining symptoms. Bursaphelenchus species were found only in 0.73% of insects and 0.47% of the total number of wood samples. Bursaphelenchus borealis and B. pinophilus dauer juveniles were found associated with the insect vectors Dryocetes autographus and Pityogenes bidentatus, respectively. While a total of seven Bursaphelenchus species are now reported from the Czech Republic, the status of B. xylophilus remains as absent

The differential polarizability of CHO cells can be used to monitor changes in metabolism

The continuous monitoring of cell growth and viability is an integral part of biopharmaceutical production. Measurements of changes in the polarizability of individual cells can identify early emerging sub-populations of apoptotic cells in a dielectrophoretic (DEP) cytometer designed at the University of Manitoba. In this instrument the trajectory of individual cells was tracked as they passed through a bank of electrodes (sensitivity: 0.1 µm; rate: 5 cells per second) designed to differentially perturb the cells according to their polarizability. This perturbation was recorded as a force index (FI), which was related to the electrical displacement of the cells. Using this principle we were able to show the changing profile of Mab-secreting CHO cells from samples taken from a bioreactor during the later stages of culture. These sub-populations could be correlated with the fluorescent markers of apoptosis analyzed in a flow cytometer with fluorescent detection (Guava). The DEP cytometer can be compared to capacitance measurements of a cell population in a bioreactor using commercially available sterilizable probes (e.g. Aber). However, these probes measure an average change in the population as opposed to the analysis of single cells, which allows greater insight into the metabolic changes of sub-populations. Cytometric analysis of single cells enables low density sub-populations to be identified that might otherwise be masked by the overall response of the whole cell population. We have extended our analysis of cultures to the induction of apoptosis by alternative means such as nutrient starvation or the addition of the anti-metabolites, oligomycin, and staurosporine. In each case, discrete cell sub-populations were identified as cells passed through the various stages of apoptosis. These sub-population could be correlated with alternative measurements by fluorescent markers, a cell population-based capacitance probe and trypan blue exclusion. In the batch and the starvation culture the early changes in the measured FI of cells correlated with the Annexin V fluorescent assay, which was associated with early phase apoptosis. For the oligomycin and staurosporine cultures changes in the FI could be correlated to modifications in the mitochondrial metabolism linked with early apoptosis for both inducers. Overall our results showed that the DEP cytometer offers a sensitive method of monitoring the metabolic state of CHO cells during a bioreactor run or following treatment with a metabolic inhibitor using single cell analysis

The oxygen binding protein, HEMOXCell(R), increases CHO cell growth and extends viability by enhancing oxygen delivery

The continuous monitoring of cell growth and viability is an integral part of biopharmaceutical production. Measurements of changes in the polarizability of individual cells can identify early emerging sub-populations of apoptotic cells in a dielectrophoretic (DEP) cytometer designed at the University of Manitoba. In this instrument the trajectory of individual cells was tracked as they passed through a bank of electrodes (sensitivity: 0.1 µm; rate: 5 cells per second) designed to differentially perturb the cells according to their polarizability. This perturbation was recorded as a force index (FI), which was related to the electrical displacement of the cells. Using this principle we were able to show the changing profile of Mab-secreting CHO cells from samples taken from a bioreactor during the later stages of culture. These sub-populations could be correlated with the fluorescent markers of apoptosis analyzed in a flow cytometer with fluorescent detection (Guava). The DEP cytometer can be compared to capacitance measurements of a cell population in a bioreactor using commercially available sterilizable probes (e.g. Aber). However, these probes measure an average change in the population as opposed to the analysis of single cells, which allows greater insight into the metabolic changes of sub-populations. Cytometric analysis of single cells enables low density sub-populations to be identified that might otherwise be masked by the overall response of the whole cell population. We have extended our analysis of cultures to the induction of apoptosis by alternative means such as nutrient starvation or the addition of the anti-metabolites, oligomycin, and staurosporine. In each case, discrete cell sub-populations were identified as cells passed through the various stages of apoptosis. These sub-population could be correlated with alternative measurements by fluorescent markers, a cell population-based capacitance probe and trypan blue exclusion. In the batch and the starvation culture the early changes in the measured FI of cells correlated with the Annexin V fluorescent assay, which was associated with early phase apoptosis. For the oligomycin and staurosporine cultures changes in the FI could be correlated to modifications in the mitochondrial metabolism linked with early apoptosis for both inducers. Overall our results showed that the DEP cytometer offers a sensitive method of monitoring the metabolic state of CHO cells during a bioreactor run or following treatment with a metabolic inhibitor using single cell analysis

Kollokationer som fraseologisk kategori set fra forskellige synsvinker

The delimitation of collocations as a category on its own can be done along different lines. The purpose of this paper is to discuss the definition and use of the term ’collocation’ from various points of view. Collocations differ from free word combinations on one hand and from idioms on the other, having two characteristic features: a certain degree of meaning compositionality and a certain degree of formal, structural and lexical fixedness. These features appear in several combinations which form the basis of different classifications. First, criteria and classifications are discussed; second, the use of the term in lexicographic theory and corpus linguistics is analyzed. The discussion is illustrated by a few examples of lexicographic representation in Danish dictionaries. Finally, an outline of various descriptive approaches with their focus on particular features is presented

College student alcohol use: a validation of naturally occurring quantity and frequency of alcohol use subgroups and cluster analytically derived typologies for males and females

This investigation sought to identify, characterize, and contrast alcohol use subgroups, by gender, in a college sample. Subgroups were formed by (1) alcohol consumption patterns and (2) cluster analytic methods. The resulting subgroups were externally validated with instruments selected from various domains;In general, univariate and multivariate analyses evidenced the existence of empirically and conceptually distinct subgroups for the majority of cluster derived subgroups. The quantity-frequency of alcohol use subgroups exhibited overall Minnesota Multiphasic Personality Inventory (MMPI) and Personality Research Form (PRF) empirical differences but were conceptually homogeneous. Relative differences were exhibited in individual scale elevations and, in some instances, did not reflect behavioral or cognitive uniqueness. However, many PRF derived clusters did manifest conceptually distinct MMPI profiles;The vast majority of all subgroups were characterized by MMPI Ma and Sc scale elevations. Female PRF derived clusters exhibited additional MMPI F and PD scale elevations with some male quantity-frequency of alcohol use subgroups evidencing F scale elevations;Overall, PRF subgroup commonalities were found for the Infrequency and Understanding scales. Further analysis revealed a wide scatter of PRF commonalities and uniqueness reflecting statistical and conceptual subgroup distinctions for the PRF derived clusters. The majority of quantity-frequency of alcohol use subgroup distinctions were subtle and of little utility in distinguishing subgroups;Compared with previous studies, male alcohol consumption patterns increased slightly, from an already elevated level, while college females demonstrated a dramatic upswing in their drinking habits. There was an overall increase in college student moderately heavy and heavy drinking. Furthermore, college students acknowledge an alarming number of alcohol related behavioral problems

Choledocholithiasis Causing Obstructive Jaundice 52 Years After Cholecystectomy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111145/1/j.1532-5415.1995.tb07416.x.pd

In ovo omnia: diversification by duplication in fish and other vertebrates

Gene and genome duplications are considered to be the main evolutionary mechanisms contributing to the unrivalled biodiversity of bony fish. New studies of vitellogenin yolk proteins, including a report in BMC Evolutionary Biology, reveal that the genes underlying key evolutionary innovations and adaptations have undergone complex patterns of duplication and functional evolution