Cooperative hunting in a discrete predator-prey system

We propose and investigate a discrete-time predator-prey system with cooperative hunting in the predator population. The model is constructed from the classical Nicholson-Bailey host-parasitoid system with density dependent growth rate. A sufficient condition based on the model parameters for which both populations can coexist is derived, namely that the predator's maximal reproductive number exceeds one. We study existence of interior steady states and their stability in certain parameter regimes. It is shown that the system behaves asymptotically similar to the model with no cooperative hunting if the degree of cooperation is small. Large cooperative hunting, however, may promote persistence of the predator for which the predator would otherwise go extinct if there were no cooperation

Is the Web ready for HTTP/2 Server Push?

HTTP/2 supersedes HTTP/1.1 to tackle the performance challenges of the modern Web. A highly anticipated feature is Server Push, enabling servers to send data without explicit client requests, thus potentially saving time. Although guidelines on how to use Server Push emerged, measurements have shown that it can easily be used in a suboptimal way and hurt instead of improving performance. We thus tackle the question if the current Web can make better use of Server Push. First, we enable real-world websites to be replayed in a testbed to study the effects of different Server Push strategies. Using this, we next revisit proposed guidelines to grasp their performance impact. Finally, based on our results, we propose a novel strategy using an alternative server scheduler that enables to interleave resources. This improves the visual progress for some websites, with minor modifications to the deployment. Still, our results highlight the limits of Server Push: a deep understanding of web engineering is required to make optimal use of it, and not every site will benefit.Comment: More information available at https://push.netray.i

Determinants of Online Auction Participation: How Much Do Web Knowledge and Risk Perception Matter?

This study extends the research on online consumer behavior by examining the effect of Web knowledge and risk perception on individual attitude towards and intention to participate in online auction. The survey findings show that individuals with high Web knowledge tend to form positive attitudes towards online auction. By contrast, individuals who have heightened concerns about Internet privacy and security show less favorable attitudes towards online auction. Consistent with the attitude-intention model, attitude appears to mediates the effect of know and risk perception on intention. Research and practical implications of these results are discussed

E-Business Investment in the Travel Industry: A Preliminarily Study

E-business has been rapidly growing in the retailing and service industries. As an innovative mode for selling and delivering products/services, e-business model involves both technological and strategic changes. It has been observed that firms in the same industry may adopt e-business model at different paces. Questions remain why some firms tend to actively implement e-business while others take cautious attitudes toward it. Scholars from different research fields have approached to the innovation adoption issue from various theoretical perspectives. Drawing upon the innovation adoption literature as well as institutional theory, market orientation theory, and strategic choice perspective, this study proposes a multi-level explanatory model about e -business adoption in the travel industry. We identified some important enviro nmental, organizational, and managerial variables that may affect e-business investment. Using survey data from a sample of travel agencies in Taiwan, we found that external competitive pressure, the firm’s innovation orientation, its IT human resource base, the CEO’s perception of e-business advantage, and CEO openness to experience were associated to e-business investment

Neurologic Changes and Depression

This article covers current research on the relationship between depression and cognitive impairment in older adults. First, it approaches the clinical assessment of late-life depression and comorbid cognitive impairment. Cognitive risk factors for suicide are discussed. Research is then provided on neuropsychological changes associated with depression, discussing subjective cognitive impairment, mild cognitive impairment, and dementia profiles. Additionally, literature regarding neuroimaging and biomarker findings in depressed older adults is presented. Finally, therapeutic models for treatment of late-life depression are also discussed, including psychotherapy models, holistic treatments, pharmacologic approaches, and brain-stimulation therapies

Disambiguating the species of biomedical named entities using natural language parsers

Motivation: Text mining technologies have been shown to reduce the laborious work involved in organizing the vast amount of information hidden in the literature. One challenge in text mining is linking ambiguous word forms to unambiguous biological concepts. This article reports on a comprehensive study on resolving the ambiguity in mentions of biomedical named entities with respect to model organisms and presents an array of approaches, with focus on methods utilizing natural language parsers

Healthsouth Corporation: The First Case Against A Company Under The Sarbanes-Oxley Act

HealthSouth Corporation, one of the nation’s largest healthcare providers, was the first company charged under the provisions of the Sarbanes-Oxley Act.  HealthSouth’s CEO, Richard Scrushy, and 16 of its executives were indicted for allegedly using a sophisticated scheme to overstate the company’s earnings by as much as $2.7 billion between 1986 and 2002.  Fifteen of the sixteen indicted executives pleaded guilty and another was convicted by jurors.  After five months of court hearing, Scrushy was acquitted of all criminal charges.  However, he remains a defendant in 40 cases filed by former HealthSouth investors and creditors.   This case is based on court materials and other publicly available information and has been used in several undergraduate and MBA courses.  The case and the accompanying teaching notes have proven to be an effective tool in teaching students the Sarbanes-Oxley Act and in helping students become more ethically conscious