12,094 research outputs found

    Coherency in space of lake and river temperature and water quality records

    Get PDF
    Environmental time series observed over 100’s of monitoring locations usually possess some spatial structure in terms of common patterns throughout time, commonly described as temporal coherence. This paper will apply, develop and compare two methods for clustering time series on the basis of their patterns over time. The first approach treats the time series as functional data and applies hierarchical clustering while the second uses a state-space model based clustering approach. Both methods are developed to incorporate spatial correlation and stopping criteria are investigated to identify an appropriate number of clusters. The methods are applied to Total Organic Carbon data from river sites across Scotland

    A Flexible Endoscopic Machining Tool

    Get PDF
    AbstractFlexible endoscopic tools are considerably applied in industrial image based inspecting operations, but none of them are currently effective enough to carry out machining tasks, such as grinding. If machining and inspection can be done in a single step, significant amount of labor force, money and energy can be saved in industrial repairing and maintenance tasks. This paper proposed a concept design of novel endoscopic machining tool, which aims at quantitatively and precisely removing material from imperfect components in hard-to-reach cavities, such as turbine blades in a jet engine. Prediction models are built to estimate the pose, force and material removal rate (MRR) of a modified PENTAX ES-3801 endoscope. Preliminary experimental results show that in two-dimensional (2D) grinding configuration the MRR average error of 22% has been achieved for 18 samples tested. In the end, concept designs of self-stabilized endoscopic grinding tool are proposed and discussed

    The Impact Of A Secondary Market On Video Game Purchase Intentions

    Get PDF
    The secondary market for video game purchases is a multi-billion dollar industry that some believe is unfair to video game developers. Using the Theory of Reasoned Action (TRA), we investigated user attitudes and subjective norms and their affect on a consumer’s intention to buy new video games. While TRA has been used to study purchase intentions of material goods and digital goods, our study extends this work to investigate video games, which have both a physical and digital component. Based on a survey of 118 undergraduate students, two of the hypothesized relationships are significant predictors of intention to purchase: previous experience in the primary market and access to the secondary market. The results of this study highlight the applicability of TRA to the video game market, suggest marketing strategies for video game developers, and caution against criminalizing the resale of video games

    Einstein Cluster Alignments Revisited

    Get PDF
    We have examined whether the major axes of rich galaxy clusters tend to point toward their nearest neighboring cluster. We have used the data of Ulmer, McMillan, and Kowalski, who used position angles based on X-ray morphology. We also studied a subset of this sample with updated positions and distances from the MX Northern Abell Cluster Survey (for rich clusters (R≄1R \geq 1) with well known redshifts). A Kolmogorov-Smirnov (KS) test showed no significant signal for nonrandom angles on any scale ≀100h−1\leq 100h^{-1}Mpc. However, refining the null hypothesis with the Wilcoxon rank-sum test, we found a high confidence signal for alignment. Confidence levels increase to a high of 99.997% as only near neighbors which are very close are considered. We conclude there is a strong alignment signal in the data, consistent with gravitational instability acting on Gaussian perturbations.Comment: Minor revisions. To be published in Ap

    Active immunization against virus infections due to antigenic drift by induction of crossreactive cytotoxic T lymphocytes

    Get PDF
    We have examined whether active immunization with c13 protein, a hybrid protein of the first 81 amino acids of the viral NS1 nonstructural protein and the HA2 subunit of A/PR/8 (H1N1) hemagglutinin, could protect BALB/c mice from challenge with A/PR/8 H1 subtype virus. Mice immunized with the c13 protein had a significant reduction of pulmonary virus titers with A/PR/8 (H1) virus, but failed to limit the replication of A/PC (H3) virus, which reflects the in vitro CTL activity of c13 immune spleen cells. We observed that the epitope recognized by HA2 specific CTL, which are induced by a derivative of c13 protein, is highly conserved among H1 and H2 subtype virus strains. This led us to test whether active immunization with c13 protein would also limit pulmonary virus replication in mice infected with the A/TW virus, a virus of the H1 subtype, which was isolated in 1986, and with a virus of the H2 subtype, A/Japan/305/57. Immunized mice had significantly lower lung virus titers than did control mice, and did not possess any neutralizing antibodies to the challenger viruses. These results indicate that active immunization with a fusion protein containing the cross-reactive CTL epitope protects mice from influenza infection by inducing CTL against influenza A H1 and H2 subtype virus strains, which markedly vary in their antibody binding sites on the HA1. The ability to induce active cross-reactive immunization with a fusion protein which contains a highly conserved CTL epitope offers a model for vaccine approaches against viruses which undergo significant variations in their antibody binding sites

    Healing relationships and the existential philosophy of Martin Buber

    Get PDF
    The dominant unspoken philosophical basis of medical care in the United States is a form of Cartesian reductionism that views the body as a machine and medical professionals as technicians whose job is to repair that machine. The purpose of this paper is to advocate for an alternative philosophy of medicine based on the concept of healing relationships between clinicians and patients. This is accomplished first by exploring the ethical and philosophical work of Pellegrino and Thomasma and then by connecting Martin Buber's philosophical work on the nature of relationships to an empirically derived model of the medical healing relationship. The Healing Relationship Model was developed by the authors through qualitative analysis of interviews of physicians and patients. Clinician-patient healing relationships are a special form of what Buber calls I-Thou relationships, characterized by dialog and mutuality, but a mutuality limited by the inherent asymmetry of the clinician-patient relationship. The Healing Relationship Model identifies three processes necessary for such relationships to develop and be sustained: Valuing, Appreciating Power and Abiding. We explore in detail how these processes, as well as other components of the model resonate with Buber's concepts of I-Thou and I-It relationships. The resulting combined conceptual model illuminates the wholeness underlying the dual roles of clinicians as healers and providers of technical biomedicine. On the basis of our analysis, we argue that health care should be focused on healing, with I-Thou relationships at its core

    A Deep ROSAT HRI Observation of NGC 1313

    Full text link
    We describe a series of observations of NGC 1313 using the ROSAT HRI with a combined exposure time of 183.5 ksec. The observations span an interval between 1992 and 1998; the purpose of observations since 1994 was to monitor the X-ray flux of SN1978K, one of several luminous sources in the galaxy. No diffuse emission is detected in the galaxy to a level of ~1-2x10^37 ergs/s/arcmin^-2. A total of eight sources are detected in the summed image within the D_25 diameter of the galaxy. The luminosities of five of the eight range from \~6x10^37 to ~6x10^38 erg/s; these sources are most likely accreting X-ray binaries, similar to sources obseved in M31 and M33. The remaining three sources all emit above 10^39 erg/s. We present light curves of the five brightest sources. Variability is detected at the 99.9% level from four of these. We identify one of the sources as an NGC 1313 counterpart of a Galactic X-ray source. The light curve, though crudely sampled, most closely resembles that of a Galactic black hole candidate such as GX339-4, but with considerably higher peak X-ray luminosity. An additional seven sources lie outside of the D_25 diameter and are either foreground stars or background AGN.Comment: 18 pages, 9 figures; accepted AJ, scheduled for November 200

    Diet and Selection of Major Prey Species by Lake Michigan Salmonines, 1973–1982

    Full text link
    To elucidate prey preferences, we quantified stomach contents of 1,231 salmonines collected from inshore (21 m or shallower) southeastern Lake Michigan during 1973–1982. Predators ate 12 species of fish. Alewife Alosa pseudoharengus made up 48–79% by weight of the diet of brown trout Salmo trutta, chinook salmon Oncorhynchus tshawytscha, coho salmon Oncorhynchus kisutch, lake trout Salvelinus namaycush, and rainbow trout Salmo gairdneri. Alewives eaten ranged from 23 to 245 mm total length; 46% were 150–200 mm. Rainbow smelt Osmerus mordax eaten were 21–245 mm long and made up 4–11% of the salmoninesˈ prey. There were significant direct linear relationships between lengths of alewives and rainbow smelt eaten and lengths of the five predators. Alewives are currently declining in Lake Michigan. If their population collapses, there should be a shift to alternative prey species. We have seen no such shift through 1982, although more recent data of other investigators show a decline in the importance of alewife in salmonine diets. Diets of the midwater‐feeding chinook and coho salmon were heavily dominated by the pelagic alewife, whereas brown and lake trout diets were more diverse. This suggests that trout should have better survival and growth than salmon, because trout would be able to utilize the more benthic yellow perch, Perca flavescens, rainbow smelt, and, to some degree, bloater Coregonus hoyi. The latter species are becoming more abundant with the decline in alewife. Under the current salmonine stocking regime, alewives will continue to supply a lower and variable portion of the salmonine diet, and predatory pressure on alewife should lead to increases in endemic prey speciesˈ populations.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141728/1/tafs0677.pd
    • 

    corecore