543 research outputs found

    Spectral hardness evolution characteristics of tracking Gamma-ray Burst pulses

    Full text link
    Employing a sample presented by Kaneko et al. (2006) and Kocevski et al. (2003), we select 42 individual tracking pulses (here we defined tracking as the cases in which the hardness follows the same pattern as the flux or count rate time profile) within 36 Gamma-ray Bursts (GRBs) containing 527 time-resolved spectra and investigate the spectral hardness, EpeakE_{peak} (where EpeakE_{peak} is the maximum of the νFν\nu F_{\nu} spectrum), evolutionary characteristics. The evolution of these pulses follow soft-to-hard-to-soft (the phase of soft-to-hard and hard-to-soft are denoted by rise phase and decay phase, respectively) with time. It is found that the overall characteristics of EpeakE_{peak} of our selected sample are: 1) the EpeakE_{peak} evolution in the rise phase always start on the high state (the values of EpeakE_{peak} are always higher than 50 keV); 2) the spectra of rise phase clearly start at higher energy (the median of EpeakE_{peak} are about 300 keV), whereas the spectra of decay phase end at much lower energy (the median of EpeakE_{peak} are about 200 keV); 3) the spectra of rise phase are harder than that of the decay phase and the duration of rise phase are much shorter than that of decay phase as well. In other words, for a complete pulse the initial EpeakE_{peak} is higher than the final EpeakE_{peak} and the duration of initial phase (rise phase) are much shorter than the final phase (decay phase). This results are in good agreement with the predictions of Lu et al. (2007) and current popular view on the production of GRBs. We argue that the spectral evolution of tracking pulses may be relate to both of kinematic and dynamic process even if we currently can not provide further evidences to distinguish which one is dominant. Moreover, our statistical results give some witnesses to constrain the current GRB model.Comment: 32 pages, 26 figures, 3 tables, accepted for publication in New Astronom

    Improving kNN for human activity recognition with privileged learning using translation models.

    Get PDF
    Multiple sensor modalities provide more accurate Human Activity Recognition (HAR) compared to using a single modality, yet the latter is preferred by consumers as it is more convenient and less intrusive. This presents a challenge to researchers, as a single modality is likely to pick up movement that is both relevant as well as extraneous to the human activity being tracked and lead to poorer performance. The goal of an optimal HAR solution is therefore to utilise the fewest sensors at deployment, while maintaining performance levels achievable using all available sensors. To this end, we introduce two translation approaches, capable of generating missing modalities from available modalities. These can be used to generate missing or 'privileged' modalities at deployment to augment case representations and improve HAR.We evaluate the presented translators with k-NN classifiers on two HAR datasets and achieve up-to 5% performance improvements using representations augmented with privileged modalities. This suggests that non-intrusive modalities suited for deployment benefit from translation models that generates privileged modalities

    Virtual knowledge sharing in crowdsourcing : measurement dilemmas

    Get PDF
    Jednym z stosunkowo nowych obszarów badań współczesnej nauki o zarządzaniu jest crowdsourcing oraz zachodzące w nim wirtualnym dzieleniu się wiedzą. Jest ono definiowane jako rozpowszechnienie wiedzy przez społeczność wirtualną, informowanie innych, podawanie jej do wiadomości publicznej, oczekiwanie, że inni tę wiedzę skomentują, rozszerzą i uzupełnią. Takie dzielenie się wiedzą jest szczególnie istotne dla współtworzenia, partycypacji czy uzyskiwania innowacyjnych pomysłów przez organizację. Jednak, pomimo jego pozytywnego wpływu na organizację, dotychczas nie było ono przedmiotem kompleksowych badań. Artykuł przedstawia istniejący dorobek w zakresie sposobów pomiaru społecznościowego dzielenia się wiedzą w ramach crowdsourcingu. W opracowaniu można też znaleźć wyjaśnienia, dlaczego warto badać wirtualne dzielenie się wiedzą.One relatively new area of contemporary science research on management is crowdsourcing and virtual knowledge sharing occurring within it. It is defined as the dissemination of knowledge by a virtual community, informing others, making it public, expecting that others will comment on this knowledge, expand and complete it. Such a sharing of knowledge is particularly important for co-creating, participating, or acquiring innovative ideas by an organization. However, despite its positive impact on the organization, it has not been the subject of comprehensive research so far. This article presents the existing output in the scope of the ways of measuring community knowledge sharing within crowdsourcing. In this elaboration, explanations as to why it is worth studying virtual knowledge sharing may be found

    SEND: a system for electronic notification and documentation of vital sign observations

    Get PDF
    Background: Recognising the limitations of a paper-based approach to documenting vital sign observations and responding to national clinical guidelines, we have explored the use of an electronic solution that could improve the quality and safety of patient care. We have developed a system for recording vital sign observations at the bedside, automatically calculating an Early Warning Score, and saving data such that it is accessible to all relevant clinicians within a hospital trust. We have studied current clinical practice of using paper observation charts, and attempted to streamline the process. We describe our user-focussed design process, and present the key design decisions prior to describing the system in greater detail. Results: The system has been deployed in three pilot clinical areas over a period of 9 months. During this time, vital sign observations were recorded electronically using our system. Analysis of the number of observations recorded (21,316 observations) and the number of active users (111 users) confirmed that the system is being used for routine clinical observations. Feedback from clinical end-users was collected to assess user acceptance of the system. This resulted in a System Usability Scale score of 77.8, indicating high user acceptability. Conclusions: Our system has been successfully piloted, and is in the process of full implementation throughout adult inpatient clinical areas in the Oxford University Hospitals. Whilst our results demonstrate qualitative acceptance of the system, its quantitative effect on clinical care is yet to be evaluated

    Understanding and meeting the needs of those using growth hormone injection devices

    Get PDF
    BACKGROUND: Recombinant human growth hormone (r-hGH) is used to treat: growth hormone deficiency in children and adults; children born small for gestational age; Turner's syndrome; and chronic renal failure. r-hGH is administered by daily subcutaneous injection and may be given using a number of different administration devices. The aim of this survey was, firstly, to identify which attributes of an r-hGH administration device are considered most important to physicians, teenage patients, parents of young children requiring GH and nurses who have experience of r-hGH administration, and, secondly, to determine how they rate existing devices in each of these key attributes. METHODS: The opinions of 67 individuals with experience in r-hGH administration were captured in discussion sessions. Parents, physicians and nurses were asked to rate 19 device attributes by completing a questionnaire, and to rank four different r-hGH administration devices (including a conceptual electronic device) in order of preference. RESULTS: Reliability, ease of use, lack of pain during injection, safety in use, storage, and number of steps in preparation before use, during use and after were considered to be the five most desirable attributes of an r-hGH administration device. An electronic device was preferred to an automatic, multi-dose injection device, a needle-free injection device or a manual, ready-to-use, disposable injection device. CONCLUSION: In the opinion of physicians, nurses and parents using r-hGH injection devices, an ideal device must combine reliability with simplicity, while delivering treatment with minimal pain. An electronic device, which combines many of the most useful features of existing devices with novel functions, was the preferred option for r-hGH administration

    Surface molecular tailoring using pH-switchable supramolecular dendron-ligand assemblies

    Get PDF
    [Image: see text] The rational design of materials with tailored properties is of paramount importance for a wide variety of biological, medical, electronic and optical applications. Here we report molecular level control over the spatial distribution of functional groups on surfaces utilizing self-assembled monolayers (SAMs) of pH-switchable surface-appended pseudorotaxanes. The supramolecular systems were constructed from a poly(aryl ether) dendron-containing a dibenzo[24]crown-8 (DB24C8) macrocycle and a thiol ligand-containing a dibenzylammonium recognition site and a fluorine end group. The dendron establishes the space (dendritic effect) that each pseudorotaxane occupies on the SAM. Following SAM formation, the dendron is released from the surface by switching off the noncovalent interactions upon pH stimulation, generating surface materials with tailored physical and chemical properties

    AnyNovel: detection of novel concepts in evolving data streams: An application for activity recognition

    Get PDF
    A data stream is a flow of unbounded data that arrives continuously at high speed. In a dynamic streaming environment, the data changes over the time while stream evolves. The evolving nature of data causes essentially the appearance of new concepts. This novel concept could be abnormal such as fraud, network intrusion, or a sudden fall. It could also be a new normal concept that the system has not seen/trained on before. In this paper we propose, develop, and evaluate a technique for concept evolution in evolving data streams. The novel approach continuously monitors the movement of the streaming data to detect any emerging changes. The technique is capable of detecting the emergence of any novel concepts whether they are normal or abnormal. It also applies a continuous and active learning for assimilating the detected concepts in real time. We evaluate our approach on activity recognition domain as an application of evolving data streams. The study of the novel technique on benchmarked datasets showed its efficiency in detecting new concepts and continuous adaptation with low computational cost

    Activation of PKR Causes Amyloid ß-Peptide Accumulation via De-Repression of BACE1 Expression

    Get PDF
    BACE1 is a key enzyme involved in the production of amyloid ß-peptide (Aß) in Alzheimer's disease (AD) brains. Normally, its expression is constitutively inhibited due to the presence of the 5′untranslated region (5′UTR) in the BACE1 promoter. BACE1 expression is activated by phosphorylation of the eukaryotic initiation factor (eIF)2-alpha, which reverses the inhibitory effect exerted by BACE1 5′UTR. There are four kinases associated with different types of stress that could phosphorylate eIF2-alpha. Here we focus on the double-stranded (ds) RNA-activated protein kinase (PKR). PKR is activated during viral infection, including that of herpes simplex virus type 1 (HSV1), a virus suggested to be implicated in the development of AD, acting when present in brains of carriers of the type 4 allele of the apolipoprotein E gene. HSV1 is a dsDNA virus but it has genes on both strands of the genome, and from these genes complementary RNA molecules are transcribed. These could activate BACE1 expression by the PKR pathway. Here we demonstrate in HSV1-infected neuroblastoma cells, and in peripheral nervous tissue from HSV1-infected mice, that HSV1 activates PKR. Cloning BACE1 5′UTR upstream of a luciferase (luc) gene confirmed its inhibitory effect, which can be prevented by salubrinal, an inhibitor of the eIF2-alpha phosphatase PP1c. Treatment with the dsRNA analog poly (I∶C) mimicked the stimulatory effect exerted by salubrinal over BACE1 translation in the 5′UTR-luc construct and increased Aß production in HEK-APPsw cells. Summarizing, our data suggest that PKR activated in brain by HSV1 could play an important role in the development of AD

    QTLs for height: results of a full genome scan in Dutch sibling pairs.

    Get PDF
    Height is a highly heritable, complex trait. At present, the genes responsible for the variation in height have not yet been identified. This paper summarizes the results of previous linkage studies and presents results of an additional linkage analysis. Using data from the Netherlands Twin Register, a sib-pair-based linkage analysis for adult height was conducted. For 513 sib-pairs from 174 families complete genome scans and adult height were available. The strongest evidence for linkage was found for a region on chromosome 6, near markers D6S1053 and D6S1031 (LOD = 2.32). This replicated previous findings in other data sets. LOD scores ranging from 1.53 to 2.04 were found for regions on chromosomes 1, 5, 8, 10, and 18. The region on chromosome 18 (LOD = 1.83) also corresponded with the results of previous studies. Several chromosomal regions are now implied in the variance in height, but further study is needed to draw definite conclusions with regard to the significance of these regions for adult heigh

    Diabetes Health, Residence & Metabolism in Asians: the DHRMA study, research into foods from the Indian subcontinent - a blinded, randomised, placebo controlled trial

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Coronary heart disease (CHD) is highly prevalent amongst the South Asian communities in Britain. The reasons for this excess CHD risk are multifactorial, but in part relate to a susceptibility to diabetes mellitus - where the aberrant metabolism of non-esterified fatty acids (NEFA) and glucose are likely to underpin vascular disease in this population. Dietary intervention is an important and first line approach to manage increased CHD risk. However, there is limited information on the impact of the South Asian diet on CHD risk.</p> <p>Methods/Design</p> <p>The Diabetes Health, Residence & Metabolism in Asians (DHRMA) study is a blinded, randomised, placebo controlled trial that analyses the efficacy of reduced glycaemic index (GI) staples of the South Asian diet, in relation to cardio-metabolic risk factors that are commonly perturbed amongst South Asian populations - primarily glucose, fatty acid and lipoprotein metabolism and central adiposity. Using a 10-week dietary intervention study, 50 healthy South Asians will be randomised to receive either a DHRMA (reduced GI) supply of chapatti (bread), stone ground, high protein wheat flour and white basmati rice (high bran, unpolished) or commercially available (leading brand) versions chapatti wheat flour and basmati rice. Volunteers will be asked to complete a 75g oral glucose tolerance test at baseline and at 10-weeks follow-up, where blood metabolites and hormones, blood pressure and anthropometry will also be assessed in a standardised manner.</p> <p>Discussion</p> <p>It is anticipated that the information collected from this study help develop healthy diet options specific (but not exclusive) for South Asian ethnic communities.</p> <p>Trial registration</p> <p>Current Controlled Trials <a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=ISRCTN02839188">ISRCTN02839188</a></p
    corecore