5,183 research outputs found

    A New Biometric Template Protection using Random Orthonormal Projection and Fuzzy Commitment

    Full text link
    Biometric template protection is one of most essential parts in putting a biometric-based authentication system into practice. There have been many researches proposing different solutions to secure biometric templates of users. They can be categorized into two approaches: feature transformation and biometric cryptosystem. However, no one single template protection approach can satisfy all the requirements of a secure biometric-based authentication system. In this work, we will propose a novel hybrid biometric template protection which takes benefits of both approaches while preventing their limitations. The experiments demonstrate that the performance of the system can be maintained with the support of a new random orthonormal project technique, which reduces the computational complexity while preserving the accuracy. Meanwhile, the security of biometric templates is guaranteed by employing fuzzy commitment protocol.Comment: 11 pages, 6 figures, accepted for IMCOM 201

    Do Individual Investors Drive Post-Earnings Announcement Drift? Direct Evidence from Personal Trades

    Get PDF
    This study examines whether individual investors are the source of post- earnings announcement drift (PEAD). We provide evidence on how individual investors trade in response to extreme quarterly earnings surprises and on the relation between individual investors' trades and subsequent abnormal returns. We find no evidence that either individuals or any sub-category of individuals in our sample cause PEAD. Individuals are significant net buyers after both negative and positive earnings surprises. There is no indication that trading by any of our investor sub-categories explains the concentration of drift at subsequent earnings announcement dates. While post-announcement individual net buying is a significant negative predictor of stock returns over the next three quarters, individual investor trading fails to subsume any of the power of extreme earnings surprises to predict future abnormal returns.post earnings-announcement drift, trading activity, individual investors, market efficiency

    Trust boards and governance: composition and behavioural styles

    Get PDF

    Long-Term Trends in Calcifying Plankton and pH in the North Sea

    Get PDF
    Relationships between six calcifying plankton groups and pH are explored in a highly biologically productive and data-rich area of the central North Sea using time-series datasets. The long-term trends show that abundances of foraminiferans, coccolithophores, and echinoderm larvae have risen over the last few decades while the abundances of bivalves and pteropods have declined. Despite good coverage of pH data for the study area there is uncertainty over the quality of this historical dataset; pH appears to have been declining since the mid 1990s but there was no statistical connection between the abundance of the calcifying plankton and the pH trends. If there are any effects of pH on calcifying plankton in the North Sea they appear to be masked by the combined effects of other climatic (e.g. temperature), chemical (nutrient concentrations) and biotic (predation) drivers. Certain calcified plankton have proliferated in the central North Sea, and are tolerant of changes in pH that have occurred since the 1950s but bivalve larvae and pteropods have declined. An improved monitoring programme is required as ocean acidification may be occurring at a rate that will exceed the environmental niches of numerous planktonic taxa, testing their capacities for acclimation and genetic adaptation

    The Influence of Gamma-rays on the Injury and Chromosomal Aberrations of Long Bean (Vigna sesquipedalis, Fruw.)

    Get PDF
    The effects of gamma-rays on three varieties of long bean (Vigna sesquipedalis, Fruw), namely Melaka, Local Black and Local Long were studied using Jive doses ranging from 10 to 50 kR. Both Chromosomal aberrations and characteristics related to physiological damage were used to study radiation sensitivity of the varieties. In general, gamma radiation did not affect % seed germination but caused a significant reduction in characteristics related to survival, growth and fertility. Percentage chromosomal aberrations also increased with increasing dose. As the measurement of seedling height is simple, quick and highly correlated with most characteristics studied, it could be a useful parameter in the study of radiation effects on long bean. Using a critenrion of approximately 30% reduction in seedling height or 50% lethality, it is suggested that doses ranging from 30 to 50 kR would be suitable for mutation induction in long bean

    Cognitive Style as a Factor in Accounting Students\u27 Performance on Multiple Choice Examinations

    Get PDF
    Using 59 final year accounting students as subjects and multiple regression analysis, this paper tests the hypothesis that accounting students\u27 performance on multiple choice examinations is related to field dependence cognitive style. Results support the hypothesis and suggest that in evaluating student performances in multiple choice examinations, accounting academics should bear in mind that the scores on these examinations may be partly a function of students\u27 cognitive style. This finding has implications for the use of multiple choice examinations in classroom evaluations

    Microbiological findings and prescribing trends in SARS- CoV-2 positive patients in two United Kingdom Hospitals

    Get PDF
    Objective: To describe antibiotic prescribing and microbiological findings in patients admitted to two London hospitals with COVID-19. Methods: This is a retrospective review of confirmed SARS-CoV-2 infected adults admitted between 9th February and 10th May 2020. Demographics, critical care unit (CCU) admission, antibiotic prescribing and microbiology results within 10 days of COVID-19 diagnosis were analysed. Results: 1155 patients were identified. 32.9% (380) died. 12.4% (143) had positive microbiology. After excluding likely contaminants, 6.9% (80) had clinically significant microbiology. The most common organisms isolated from blood cultures were Escherichia coli 9.5% (7), Klebsiella pneumoniae 4.0% (3), and Staphylococcus aureus 2.7% (2). A high percentage of blood cultures yielded coagulase negative staphylococci (51/74, 68.9%) and likely represented contamination. Organisms isolated from lower respiratory tract samples included Candida albicans 44.4% (12), Staphylococcus aureus 22.2% (6), Klebsiella species 11.0% (3), Pseudomonas aeruginosa 11.0% (3), and Citrobacter species 11% (3). Legionella and pneumococcal urinary antigen tests were positive in 0/117 and 2/71 (2.8%) samples. 91% (1051) of patients received antibiotics. Clarithromycin (24.2% total antibiotic use) and amoxicillin (21%) were most frequently used, followed by piperacillin-tazobactam (12.6%), gentamicin (10.6%), co-amoxiclav (9.3%) and meropenem (3.2%). Piperacillin-tazobactam or meropenem use was associated with a higher length of stay and mortality. Conclusions: Positive microbiology in COVID-19 patients is uncommon. Antibiotic use was widespread, despite lack of microbiological evidence of co-infection. When present, positive microbiology was more likely due to gram negative bacteria. Current local clinical and antimicrobial guidelines have incorporated these findings and recommend against routine antibiotic use in COVID-19 patients

    Association of Epstein-Barr virus with nasopharyngeal carcinoma and current status of development of cancer-derived cell lines

    Get PDF
    It is well known that the Epstein-Barr virus (EBV) contributes directly to tumourigenesis in nasopharyngeal carcinoma (NPC), primarily in the undifferentiated form of NPC (WHO type III; UNPC or UC), which is commonly found in South East Asia. Unfortunately, research in NPC has been severely hampered by the lack of authentic EBV-positive (EBV+) human NPC cell lines for study. Since 1975, there have been more than 20 reported NPC cell lines. However, many of these NPC-derived cell lines do not express EBV transcripts in long-term culture, and therefore that finding may dispute the fundamental theory of NPC carcinogenesis. In fact, currently only one EBV+ human NPC cell line (C-666) in long-term culture has been reported. Hence, most of the NPC cell lines may not be representative of the disease itself. In order to better understand and treat NPC, there is an urgent need to develop more EBV+ human NPC cell lines. In this review, we discuss the authenticity of existing NPC cell lines and the impact of our understanding of NPC biology on the treatment of the disease and the relationship of EBV to NPC in the context of cell lines
    corecore