108 research outputs found

    Challenging The Global, Rediscovering The Local: Voluntary Market Restriction In C2C E-Marketplaces

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    The current age of networked information systems brings concerns that in an increasingly global world the dominance of multinational corporations overrides regional and national identities. This view is challenged by the concept of glocalisation where ideas in the global environment are adapted to take account of local cultures. Many organisations operating globally seek to adapt their business strategies to fit with local environments. However, in an increasingly glocalized world organisations may curtail their market by forming boundaries around their online presence; in essence making local what is potentially global. We have identified this strategy of boundedness as ‘voluntary market restriction’. This study aims to examine voluntary market restriction in the consumer-to-consumer (C2C) space where online marketplaces are differentiating themselves by creating boundaries within which they embed communities. This paper examines three C2C e-marketplaces with strong similarities in their market mechanisms that have the potential to operate globally, although two have chosen not to do so. These two market makers have put boundaries around their markets; one by language and one by geography. They have succeeded in wresting considerable local market share from the global e-marketplace. The paper concludes by discussing the implications of the research and suggestions for future study

    Radio Emission from SN 2001gd in NGC 5033

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    We present the results of monitoring the radio emission from the Type IIb supernova SN 2001gd between 2002 February 8 and 2002 October 28. Most of the data were obtained using the Very Large Array at the five wavelengths of λλ\lambda \lambda1.3 cm (22.4 GHz), 2.0 cm (14.9 GHz), 3.6 cm (8.44 GHz), 6.2 cm (4.86 GHz), and 21 cm (1.4 GHz). Observations were also made with Giant Meterwave Radio Telescope at λ\lambda21 cm (1.4 GHz). The object was discovered optically well after maximum light, making any determination of the early radio evolution difficult. However, subsequent observations indicate that the radio emission has evolved regularly in both time and frequency and is well described by the SN shock/circumstellar medium interaction model.Comment: 16 pages 2 figures to appear in Astrophysical Journa

    Antigenic variation in <i>Trypanosoma brucei</i>: joining the DOTs

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    African trypanosomes, such as &lt;i&gt;Trypanosoma brucei&lt;/i&gt;, are protistan parasites that cause sleeping sickness. Though first described more than a century ago, trypanosomes remain a blight on the health of the human population and on the economy of sub-Saharan Africa. &lt;i&gt;T. brucei&lt;/i&gt; replicates in the bloodstream of infected mammals and traverses the blood-brain barrier to enter the central nervous system in the late, frequently fatal, stages of the disease. Because of its extracellular lifestyle, &lt;i&gt;T. brucei&lt;/i&gt; is continuously exposed to antibody challenge. To circumvent this, the parasite uses antigenic variation of a surface protein named the variant surface glycoprotein (VSG). Around 107 VSG molecules are expressed on the parasite's cell surface, creating a dense coat that prevents adaptive immunity from detecting or accessing invariant antigens. However, antibodies against the expressed VSG are generated, and periodic switches to an immunologically distinct VSG coat are necessary for parasite survival. Such switches are pre-emptive of the immune response and contribute to the pattern of trypanosome growth seen in an infected host (Figure 1): parasite numbers increase, but then drop as VSG-specific antibodies are raised by the host. Cells that have switched to another VSG coat survive this killing and seed the outgrowth of a subsequent peak of parasites, which is again decimated by anti-VSG immune killing. As a survival strategy, antigenic variation succeeds by prolonging the time that the parasite

    The effects of rural and urban areas on time allocated in self-employment : differences between men and women

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    This study investigates the association of the rural−urban divide and the time individuals allocate in self-employment. The empirical analysis uses fixed effects modelling on data from the UK Household Longitudinal Survey over the period 2009−2019. The study identifies significant differences in the time men and women allocate in self-employment between rural and urban areas according to their career age group. While men and women tend to allocate more time in self-employment in their senior career age when residents of urban areas, the time they allocate in self-employment between rural and urban areas in early- and mid-career age differs markedly. More importantly, we find that significant differences exist not only between residents of rural and urban areas, but also between residents of these areas and in-migrants to these areas. We find a significant positive effect on the time senior career age women who migrate to rural areas allocate in self-employment. In contrast, we find that early career men who move from rural to urban areas allocate significantly more time in self-employment. The results reveal the existence of complex dynamics between gender and age, which affect the allocation of time in self-employment between rural and urban areas

    A CHANDRA SURVEY OF NEARBY SPIRAL GALAXIES. I. POINT SOURCE CATALOGS

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    Emission from discrete point sources dominates the X-ray luminosity in spiral galaxies. We present results from a survey of 11 nearby, nearly face-on spiral galaxies with the Chandra X-ray Observatory. These galaxies span the Hubble sequence for spirals, allowing insights into the X-ray source population of many diverse systems. In this paper, we present source lists for the 11 galaxies along with fluxes, luminosities, X-ray colors, and variability properties. We briefly discuss X-ray luminosity functions and how they relate to star formation of the host galaxies. We also discuss source colors and variability and what these can tell us about the composition of the X-ray source population

    Simultaneous infrared and optical observations of the transiting debris cloud around WD 1145+017

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    We present multiwavelength photometric monitoring of WD 1145+017, a white dwarf exhibiting periodic dimming events interpreted to be the transits of orbiting, disintegrating planetesimals. Our observations include the first set of near-infrared light curves for the object, obtained on multiple nights over the span of 1 month, and recorded multiple transit events with depths varying between ∼20 and 50 per cent. Simultaneous near-infrared and optical observations of the deepest and longest duration transit event were obtained on two epochs with the Anglo-Australian Telescope and three optical facilities, over the wavelength range of 0.5–1.2μm. These observations revealed no measurable difference in transit depths for multiple photometric pass bands, allowing us to place a 2σ lower limit of 0.8μm on the grain size in the putative transiting debris cloud. This conclusion is consistent with the spectral energy distribution of the system, which can be fit with an optically thin debris disc with minimum particle sizes of 10+5−3μm

    Exploring the negotiation thesis application among ski resort tourists: a segmentation approach

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    The negotiation thesis offers a framework for understanding the participation decision making of tourists. Unlike previous studies that investigate the causal relationship between constraints and tourists’ revisit intention, this study identified distinct segments of ski tourist based on the relative strength of constraints experienced and then investigated their decision-making process across a sample of 1,348 tourists of ski resorts. Chi-Squared Automated Interaction Detection (CHAID) analysis revealed that the decision making process regarding intention to revisit a ski destination varies between highly versus less constrained ski tourists, indicating different relative strengths of interpersonal, intrapersonal and structural constraints and different interactions among them when predicting revisit intention. On a practical basis, albeit the vast majority of participants were willing to repeat its visit, we offer customized per segment recommendations on increasing frequency of visitation and spending levels

    Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. II: The Second Year (2009-2010)

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    As an extension of the project in Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 61 SU UMa-type dwarf novae mainly observed during the 2009-2010 season. The newly obtained data confirmed the basic findings reported in Kato et al. (2009): the presence of stages A-C, as well as the predominance of positive period derivatives during stage B in systems with superhump periods shorter than 0.07 d. There was a systematic difference in period derivatives for systems with superhump periods longer than 0.075 d between this study and Kato et al. (2009). We suggest that this difference is possibly caused by the relative lack of frequently outbursting SU UMa-type dwarf novae in this period regime in the present study. We recorded a strong beat phenomenon during the 2009 superoutburst of IY UMa. The close correlation between the beat period and superhump period suggests that the changing angular velocity of the apsidal motion of the elliptical disk is responsible for the variation of superhump periods. We also described three new WZ Sge-type objects with established early superhumps and one with likely early superhumps. We also suggest that two systems, VX For and EL UMa, are WZ Sge-type dwarf novae with multiple rebrightenings. The O-C variation in OT J213806.6+261957 suggests that the frequent absence of rebrightenings in very short-Porb objects can be a result of sustained superoutburst plateau at the epoch when usual SU UMa-type dwarf novae return to quiescence preceding a rebrightening. We also present a formulation for a variety of Bayesian extension to traditional period analyses.Comment: 63 pages, 77 figures, 1 appendix, Accepted for publication in PASJ, data correctio
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