275 research outputs found

    Extra processors versus future information in optimal deadline scheduling

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    This paper is concerned with the extra-resource analysis of online scheduling algorithms. In particular, it studies how to make use of multiple processors to counteract the lack of future information in online deadline scheduling. Our results extend the previous work that are primarily based on using a faster processor to obtain a performance guarantee. The challenge arises from the fact that jobs are sequential in nature and cannot be executed on more than one processor at the same time. Thus, a faster processor can speed up a job while multiple unit-speed processors cannot help.postprin

    Competitive deadline scheduling via additional or faster processors

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    This paper studies on-line scheduling in a single-processor system that allows preemption. The aim is to maximize the total value of jobs completed by their deadlines. It is known that if the on-line scheduler is given a processor faster (say, two times faster) than the off-line scheduler, then there exists an on-line algorithm called SLACKER that can achieve an O(1) competitive ratio. In this paper, we show that using additional unit-speed processors instead of a faster processor is a possible but not cost effective way to achieve an O(1) competitive ratio. Specifically, we find that-θ(log k) unit-speed processors are required, where k is the importance ratio. Another contribution of this paper is an improved analysis of the competitiveness of SLACKER; this new analysis enables us to show that SLACKER, when extended to multi-processor systems, can still guarantee an O(1) competitive ratio.postprin

    Crystallization and preliminary crystallographic studies of an antimicrobial protein from Pharbitis nil

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    An antimicrobial protein from seeds of Pharbitis nil (Pn-AMP) which shows an antifungal activity towards several agriculturally important plant pathogens has been crystallized in the presence of equimolar N-acetylglucosamine with sodium citrate as precipitant. The crystal belongs to the hexagonal space group P6(1)22 (or P6(5)22), with unit-cell parameters a = b = 29.33 (5), c = 133.44 (12) Angstrom. Native data were collected using a crystal at 100 K to a resolution of 1.78 Angstrom.open2

    Artificial intelligence approaches to predict coronary stenosis severity using non-invasive fractional flow reserve

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    Fractional flow reserve is the current reference standard in the assessment of the functional impact of a stenosis in coronary heart disease. In this study, three models of artificial intelligence of varying degrees of complexity were compared to fractional flow reserve measurements. The three models are the multivariate polynomial regression, which is a statistical method used primarily for correlation; the feed-forward neural network; and the long short-term memory, which is a type of recurrent neural network that is suited to modelling sequences. The models were initially trained using a virtual patient database that was generated from a validated one-dimensional physics-based model. The feed-forward neural network performed the best for all test cases considered, which were a single vessel case from a virtual patient database, a multi-vessel network from a virtual patient database, and 25 clinically invasive fractional flow reserve measurements from real patients. The feed-forward neural network model achieved around 99% diagnostic accuracy in both tests involving virtual patients, and a respectable 72% diagnostic accuracy when compared to the invasive fractional flow reserve measurements. The multivariate polynomial regression model performed well in the single vessel case, but struggled on network cases as the variation of input features was much larger. The long short-term memory performed well for the single vessel cases, but tended to have a bias towards a positive fractional flow reserve prediction for the virtual multi-vessel case, and for the patient cases. Overall, the feed-forward neural network shows promise in successfully predicting fractional flow reserve in real patients, and could be a viable option if trained using a large enough data set of real patients

    Heritability Estimation of Reliable Connectomic Features*

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    Brain imaging genetics is an emerging research field to explore the underlying genetic architecture of brain structure and function measured by different imaging modalities. However, not all the changes in the brain are a consequential result of genetic effect and it is usually unknown which imaging phenotypes are promising for genetic analyses. In this paper, we focus on identifying highly heritable measures of structural brain networks derived from diffusion weighted imaging data. Using the twin data from the Human Connectome Project (HCP), we evaluated the reliability of fractional anisotropy measure, fiber length and fiber number of each edge in the structural connectome and seven network level measures using intraclass correlation coefficients. We then estimated the heritability of those reliable network measures using SOLAR-Eclipse software. Across all 64,620 network edges between 360 brain regions in the Glasser parcellation, we observed ~5% of them with significantly high heritability in fractional anisotropy, fiber length or fiber number. All the tested network level measures, capturing the network integrality, segregation or resilience, are highly heritable, with variance explained by the additive genetic effect ranging from 59% to 77%

    Enhancing provision of written medicine information in Australia: Pharmacist, general practitioner and consumer perceptions of the barriers and facilitators

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    Background: Written medicine information can play an important role in educating consumers about their medicines. In Australia, standardised, comprehensive written information known as Consumer Medicine Information (CMI) is available for all prescription medicines. CMI is reportedly under-utilised by general practitioners (GPs) and community pharmacists in consultations, despite consumer desire for medicine information. This study aimed to determine consumers', GPs' and community pharmacists' preferences for CMI provision and identify barriers and facilitators to its use. Method. Structured questionnaires were developed and administered to a national sample of Australian consumers (phone survey), community pharmacists and GPs (postal surveys) surrounding utilisation of CMI. Descriptive and comparative analyses were conducted. Results: Half of consumers surveyed wanted to receive CMI for their prescription medicine, with spoken information preferable to written medicine information for many consumers and healthcare professionals. GPs and pharmacists remained a preferred source of medicine information for consumers, although package inserts were appealing to many among all three cohorts. Overall pharmacists were the preferred provider of CMI primarily due to their medicine expertise, accessibility and perceived availability. GPs preferred CMI dissemination through both the GP and pharmacist. Some consumers preferred GPs as the provider of medicines information because of their knowledge of the patients' medicines and/or medical history, regularity of seeing the patient and good relationship with the patient. Common barriers to CMI provision cited included: time constraints, CMI length and perceptions that patients are not interested in receiving CMI. Facilitators to enhance provision included: strategies to increase consumer awareness, longer consultation times and counseling appointments, and improvements to pharmacy software technology and workflow. Conclusion: Medicine information is important to consumers, whether as spoken, written or a combination of both. A tailored approach is needed to ascertain individual patient preference for delivery and scope of medicine information desired so that appropriate information is provided. The barriers of time and perceived attitudes of healthcare practitioners present challenges which may be overcome through changes to workplace practices, adoption of identified facilitators, and education about the positive benefits of CMI as a tool to engage and empower patients

    Piezo voltage controlled planar hall effect devices

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    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials

    Fluorescence Quantum Yield of Thioflavin T in Rigid Isotropic Solution and Incorporated into the Amyloid Fibrils

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    In this work, the fluorescence of thioflavin T (ThT) was studied in a wide range of viscosity and temperature. It was shown that ThT fluorescence quantum yield varies from 0.0001 in water at room temperature to 0.28 in rigid isotropic solution (T/η→0). The deviation of the fluorescence quantum yield from unity in rigid isotropic solution suggests that fluorescence quantum yield depends not only on the ultra-fast oscillation of ThT fragments relative to each other in an excited state as was suggested earlier, but also depends on the molecular configuration in the ground state. This means that the fluorescence quantum yield of the dye incorporated into amyloid fibrils must depend on its conformation, which, in turn, depends on the ThT environment. Therefore, the fluorescence quantum yield of ThT incorporated into amyloid fibrils can differ from that in the rigid isotropic solution. In particular, the fluorescence quantum yield of ThT incorporated into insulin fibrils was determined to be 0.43. Consequently, the ThT fluorescence quantum yield could be used to characterize the peculiarities of the fibrillar structure, which opens some new possibilities in the ThT use for structural characterization of the amyloid fibrils

    Policy and prevention approaches for disordered and hazardous gaming and internet use: an international perspective

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    Problems related to high levels of gaming and Internet usage are increasingly recognized as a potential public health burden across the developed world. The aim of this review was to present an international perspective on prevention strategies for Internet gaming disorder and related health conditions (e.g., Internet addiction), as well as hazardous gaming and Internet use. A systematic review of quantitative research evidence was conducted, followed by a search of governmental reports, policy and position statements, and health guidelines in the last decade. The regional scope included the United States, United Kingdom, Australia, China, Germany, Japan, and South Korea. Prevention studies have mainly involved school-based programs to train healthier Internet use habits in adolescents. The efficacy of selective prevention is promising but warrants further empirical attention. On an international scale, the formal recognition of gaming or Internet use as a disorder or as having quantifiable harms at certain levels of usage has been foundational to developing structured prevention responses. The South Korean model, in particular, is an exemplar of a coordinated response to a public health threat, with extensive government initiatives and long-term strategic plans at all three levels of prevention (i.e., universal, selective, and indicated). Western regions, by comparison, are dominated by prevention approaches led by non-profit organizations and private enterprise. The future of prevention of gaming and Internet problems ultimately relies upon all stakeholders working collaboratively in the public interest, confronting the reality of the evidence base and developing practical, ethical, and sustainable countermeasures
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