X-ray Shapes of Distant Clusters: the Connection to Blue Galaxy Fractions

Based on ROSAT PSPC pointed observations, we have determined the aggregate X-ray shapes of 10 distant (z = 0.17-0.54) rich clusters: A2397, A222, A520, A1689, A223B, A1758, A2218, A2111, A2125, and CL0016+16. Four of the clusters have global X-ray ellipticities greater than 0.2, as measured on a scale of diameter 3 h_{50}^{-1} Mpc. These strongly elongated clusters tend to show substantial amounts of substructure, indicating that they are dynamically young systems. Most interestingly, the global X-ray ellipticities of the clusters correlate well with their blue galaxy fractions; the correlation coefficient is 0.75 with a 90% confidence range of 0.44-0.92. This correlation suggests that blue cluster galaxies originate in the process of cluster formation, and that the blue galaxy proportion of a cluster decreases as the intracluster medium relaxes onto equipotential surfaces.Comment: Submitted to ApJL, 9 pages including 2 figure

A Tidal Disruption Flare in Abell 1689 from an Archival X-ray Survey of Galaxy Clusters

Theory suggests that a star making a close passage by a supermassive black hole at the center of a galaxy can under most circumstances be expected to emit a giant flare of radiation as it is disrupted and a portion of the resulting stream of shock-heated stellar debris falls back onto the black hole itself. We examine the first results of an ongoing archival survey of galaxy clusters using Chandra and XMM-selected data, and report a likely tidal disruption flare from SDSS J131122.15-012345.6 in Abell 1689. The flare is observed to vary by a factor of >30 over at least 2 years, to have maximum L_X(0.3-3.0 keV)> 5 x 10^{42} erg s^{-1} and to emit as a blackbody with kT~0.12 keV. From the galaxy population as determined by existing studies of the cluster, we estimate a tidal disruption rate of 1.2 x 10^{-4} galaxy^{-1} year^{-1} if we assume a contribution to the observable rate from galaxies whose range of luminosities corresponds to a central black hole mass (M_bh) between 10^6 and 10^8 M_sun.Comment: 24 pages, including 6 figures and 2 tables Accepted for publication in the Astrophysical Journa

Environmental Sustainability 2.0: Empirical Analysis of Environmental Erp Implementation

We examined the implementation of a new and rapidly emerging class of enterprise software system for managing environmental resources such as energy and carbon emissions. Analysis of the implementation of an environmental enterprise resource planning (ERP) system at a leading global software and technology services company, SunGard Data Systems Inc., yielded three primary findings. First, we found that adoption of environmental ERP supported implementation of the corporate environmental sustainability strategy, and at the same time, may transform that very strategy. Second, we uncovered unique data sharing hurdles originating in the upstream energy information value chain. Finally, we identified the role of private equity as one important stakeholder that influences environmental ERP adoption. Overall, our analysis revealed that well-established IS phenomena have unique underlying mechanisms in the environmental sustainability context, inform understanding of cause and effect, and may ultimately enhance managerial practice and inform theoretical understanding.http://deepblue.lib.umich.edu/bitstream/2027.42/91283/1/1175_Melville.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/91283/4/1175_Melville.pd

Internet Business Practices Across the Globe: Lessons from Emerging Economies

Firms in emerging economies are rapidly becoming formidable competitors to long-established industry leaders from developed economies. In some cases, emerging-economy firms are acquiring developed-economy firms, such as the recent acquisitions of Jaguar by Tata Motors and Gateway by Acer. Aside from anecdotal reports of high-level corporate strategies adopted by certain emergingeconomy firms, there is little scholarly evidence concerning the operational details of how emergingeconomy firms are becoming competitive with developed-economy firms. A common explanation is labor cost or currency advantages in emerging economies. As emerging-economy firms also compete effectively in developed economies using developed-economy resources, this cannot be the entire explanation. We propose another explanation, based on dissimilar adaptation of the Internet to enable and reinforce business practices related to customer relationships and supply chain integration. This paper draws on original survey data from over 450 firms across 10 countries as well as case examples to illuminate three key ways that Internet business practices differ between developed- and emerging-economy firms. First, compared with developed-economy firms, emerging-economy firms place a relatively higher priority on using the Internet to achieve strong customer relationships via service and support. Second, emerging-economy firms place a relatively higher priority on using the Internet to integrate processes with suppliers than do developed-economy firms. Finally, emerging-economy firms are relatively more driven to adopt Internet business practices to expand existing markets and enter new markets, and accordingly report a relatively greater impact to international sales growth compared with developed-economy firms. Our findings suggest that managers in developed-economy firms would be wise to re-assess and re-evaluate their use of Internet business practices – in particular, in the areas of customer relationships and supply chain integration – to retain competitiveness in the dynamic global economy.http://deepblue.lib.umich.edu/bitstream/2027.42/61151/1/1113_Melville.pd

Digital innovation: A review and synthesis

Organizations are under increasing pressure to apply digital technologies to renew and transform their business models. A great deal of research has examined specific phenomena, such as adoption antecedents and design methods. However, it is unclear what we know in totality, including what research streams exist, how they fit together, and fruitful opportunities for new knowledge development. We combine scientometric and systematic literature review methodologies to examine 7 dimensions of an adapted theoretical framework: initiation; development; implementation; exploitation; the role of the external competitive environment; role of internal organizational environment; and product, service, and process outcomes. From a macro perspective, we find vastly uneven coverage of research streams, diversity and diffusiveness of research, and knowledge and learning as an underlying conceptual pillar. Combined with our summary of each of the 7 research streams, these findings suggest several areas of future research, which we develop by identifying oppositions and tensions.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146990/1/isj12193.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146990/2/isj12193_am.pd

N released from organic amendments is affected by soil management history

A ryegrass bioassay was conducted to investigate the effect of soil management history on nitrogen mineralisation from composted manure and pelleted poultry manure. Soils were used from 2 field experiments comparing conventional and organic/low input management systems. When composted manure was added, soils which had received high rates of composted FYM under biodynamic management released a greater amount of nitrogen for plant uptake than those with a history of mineral or fresh manure fertilisation, suggesting that biological preconditioning may result in greater efficiency of composted FYM as a nitrogen source for plants. “Native” N mineralisation was found to be related to total soil N content

Image-based Recommendations on Styles and Substitutes

Humans inevitably develop a sense of the relationships between objects, some of which are based on their appearance. Some pairs of objects might be seen as being alternatives to each other (such as two pairs of jeans), while others may be seen as being complementary (such as a pair of jeans and a matching shirt). This information guides many of the choices that people make, from buying clothes to their interactions with each other. We seek here to model this human sense of the relationships between objects based on their appearance. Our approach is not based on fine-grained modeling of user annotations but rather on capturing the largest dataset possible and developing a scalable method for uncovering human notions of the visual relationships within. We cast this as a network inference problem defined on graphs of related images, and provide a large-scale dataset for the training and evaluation of the same. The system we develop is capable of recommending which clothes and accessories will go well together (and which will not), amongst a host of other applications.Comment: 11 pages, 10 figures, SIGIR 201