249 research outputs found

    Understanding How Users Engage in an Immersive Virtual Reality-Based Live Event

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    Virtual Reality combined with social functioning is a lucrative business direction. Due to COVID-19, a need for better social interaction is identified urgently both in education institutes and the business sector. In this paper, we will show two business cases where social functioning is needed. The first one illustrates how the business sector can use Virtual Reality Social Platform (VRSP) in remote events. As a case study, we have selected Spinverse’s Summer Day organized in Microsoft AltspaceVR. The second business case, in turn, classifies requirements for Virtual Reality Social platforms. This has been studied in close cooperation with XR Presence. Results show that current technologies offer many features to be used, but at the same time, there are needs for further development. In addition, more studies are needed in technology acceptance, usability, user experience, and business impact

    Human tumour-associated cell adhesion protein MN/CA IX: identification of M75 epitope and of the region mediating cell adhesion

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    MN/CA IX is a cell surface protein, strongly associated with several types of human carcinomas. It exerts activity of carbonic anhydrase and capacity of binding to cell surface receptors. In the present work, we used affinity purified MN/CA IX protein to demonstrate that the cells adhere to immobilized MN/CA IX and that the monoclonal antibody M75 abrogates cell attachment to MN/CA IX. Using synthetic oligopeptides, we identified M75 epitope and located it in the proteoglycan domain, which contains a sixfold tandem repeat of six amino acids GEEDLP. From phage display library of random heptapeptides we identified and chemically synthesized those which compete for the epitope with M75 and inhibit adhesion of cells to MN/CA IX. These heptapeptides might serve as lead compounds for drug design. © 2000 Cancer Research Campaig

    Expression of a novel carbonic anhydrase, CA XIII, in normal and neoplastic colorectal mucosa

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    BACKGROUND: Carbonic anhydrase (CA) isozymes may have an important role in cancer development. Some isozymes control pH homeostasis in tumors that appears to modulate the behaviour of cancer cells. CA XIII is the newest member of the CA gene family. It is a cytosolic isozyme which is expressed in a number of normal tissues. The present study was designed to investigate CA XIII expression in prospectively collected colorectal tumor samples. METHODS: Both neoplastic and normal tissue specimens were obtained from the same patients. The analyses were performed using CA XIII-specific antibodies and an immunohistochemical staining method. For comparison, the tissue sections were immunostained for other cytosolic isozymes, CA I and II. RESULTS: The results indicated that the expression of CA XIII is down-regulated in tumor cells compared to the normal tissue. The lowest signal was detected in carcinoma samples. This pattern of expression was quite parallel for CA I and II. CONCLUSION: The down-regulation of cytosolic CA I, II and XIII in colorectal cancer may result from reduced levels of a common transcription factor or loss of closely linked CA1, CA2 and CA13 alleles on chromosome 8. Their possible role as tumor suppressors should be further evaluated

    Connections between atmospheric sulphuric acid and new particle formation during QUEST III–IV campaigns in Heidelberg and Hyytiälä

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    This study investigates the connections between atmospheric sulphuric acid and new particle formation during QUEST III and BACCI/QUEST IV campaigns. The campaigns have been conducted in Heidelberg (2004) and Hyytiälä (2005), the first representing a polluted site surrounded by deciduous forest, and the second a rural site in a boreal forest environment. We have studied the role of sulphuric acid in particle formation and growth by determining 1) the power-law dependencies between sulphuric acid ([H<sub>2</sub>SO<sub>4</sub>]), and particle concentrations (<I>N</I><sub>3&ndash;6</sub>) or formation rates at 1 nm and 3 nm (<I>J</i><sub>1</sub> and <I>J</I><sub>3</sub>); 2) the time delays between [H<sub>2</sub>SO<sub>4</sub>] and <I>N</I><sub>3&ndash;6</sub> or <I>J</I><sub>3</sub>, and the growth rates for 1&ndash;3 nm particles; 3) the empirical nucleation coefficients <I>A</I> and <I>K</I> in relations <I>J</I><sub>1</sub>=<I>A</I>[H<sub>2</sub>SO<sub>4</sub>] and <I>J</I><sub>1</sub>=<I>K</I>[H<sub>2</sub>SO<sub>4</sub>]<sup>2</sup>, respectively; 4) theoretical predictions for <I>J</I><sub>1</sub> and <I>J</I><sub>3</sub> for the days when no significant particle formation is observed, based on the observed sulphuric acid concentrations and condensation sinks. In both environments, <I>N</I><sub>3&ndash;6</sub> or <I>J</I><sub>3</sub> and [H<sub>2</sub>SO<sub>4</sub>] were linked via a power-law relation with exponents typically ranging from 1 to 2. The result suggests that the cluster activation theory and kinetic nucleation have the potential to explain the observed particle formation. However, some differences between the sites existed: The nucleation coefficients were about an order of magnitude greater in Heidelberg than in Hyytiälä conditions. The time lags between <I>J</I><sub>3</sub> and [H<sub>2</sub>SO<sub>4</sub>] were consistently lower than the corresponding delays between <I>N</I><sub>3&ndash;6</sub> and [H<sub>2</sub>SO<sub>4</sub>]. The exponents in the <I>J</I><sub>3</sub>&#x221D;[H<sub>2</sub>SO<sub>4</sub> ]<sup>n<sub>J3</sub></sup>-connection were consistently higher than or equal to the exponents in the relation <I>N</I><sub>3&ndash;6</sub>&#x221D;[H<sub>2</sub>SO<sub>4</sub> ]<sup>n<sub>N36</sub></sup>. In the <I>J</I><sub>1</sub> values, no significant differences were found between the observed rates on particle formation event days and the predictions on non-event days. The <I>J</I><sub>3</sub> values predicted by the cluster activation or kinetic nucleation hypotheses, on the other hand, were considerably lower on non-event days than the rates observed on particle formation event days. This study provides clear evidence implying that the main process limiting the observable particle formation is the competition between the growth of the freshly formed particles and their loss by scavenging, rather than the initial particle production by nucleation of sulphuric acid. In general, it can be concluded that the simple models based on sulphuric acid concentrations and particle formation by cluster activation or kinetic nucleation can predict the occurence of atmospheric particle formation and growth well, if the particle scavenging is accurately accounted for
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