249 research outputs found

    Continuous Monitoring of Distributed Data Streams over a Time-based Sliding Window

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    The past decade has witnessed many interesting algorithms for maintaining statistics over a data stream. This paper initiates a theoretical study of algorithms for monitoring distributed data streams over a time-based sliding window (which contains a variable number of items and possibly out-of-order items). The concern is how to minimize the communication between individual streams and the root, while allowing the root, at any time, to be able to report the global statistics of all streams within a given error bound. This paper presents communication-efficient algorithms for three classical statistics, namely, basic counting, frequent items and quantiles. The worst-case communication cost over a window is O(kϵlogϵNk)O(\frac{k} {\epsilon} \log \frac{\epsilon N}{k}) bits for basic counting and O(kϵlogNk)O(\frac{k}{\epsilon} \log \frac{N}{k}) words for the remainings, where kk is the number of distributed data streams, NN is the total number of items in the streams that arrive or expire in the window, and ϵ<1\epsilon < 1 is the desired error bound. Matching and nearly matching lower bounds are also obtained.Comment: 12 pages, to appear in the 27th International Symposium on Theoretical Aspects of Computer Science (STACS), 201

    THE EFFECTS OF USING SELF-VIDEO RECORDING ON EFL HIGH SCHOOL STUDENTS’ LEXICON KNOWLEDGE

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    This study aims to investigate the effects of using self-video recording on EFL high school students’ lexicon knowledge. Participants include 80 EFL high school students in the Mekong Delta divided into two groups, namely the control and experimental group. Pretest and posttest were done to collect quantitative data before and after the treatment. After the treatment, the results of the experimental groups were higher than that of the control one in terms of lexicon knowledge. Therefore, this study gives recommendations for further studies in other aspects of speaking skills or speaking skills in general.  Article visualizations

    Caloric Intake, Dietary Lifestyles, Macronutrient Composition, and Alzheimer' Disease Dementia

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    Alzheimer's disease is a devastating neurodegenerative condition currently affecting over 5 million elderly individuals in the United States. There is much evidence suggesting that certain dietary lifestyles can help to prevent and possibly treat Alzheimer's disease. In this paper, we discuss how certain cardiovascular and diabetic conditions can induce an increased susceptibility for Alzheimer's disease and the mechanisms through which this occurs. We further discuss how the consumption of certain foods or food components can help to reduce one's risk for Alzheimer's disease and may possibly be developed as a therapeutic agent

    Gut Microbiome-Modified Polyphenolic Compounds Inhibit α-Synuclein Seeding and Spreading in α-Synucleinopathies

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    Misfolding, aggregation and deposition of α-synuclein (α-syn) are major pathologic characteristics of Parkinson’s disease (PD) and the related synucleinopathy, multiple system atrophy (MSA). The spread of α-syn pathology across brain regions is thought to play a key role in the onset and progression of clinical phenotypes. Thus, there is increasing interest in developing strategies that target and attenuate α-syn aggregation and spread. Recent studies of brain-penetrating polyphenolic acids, namely, 3-hydroxybenzoic acid (3-HBA), 3,4-dihydroxybenzoic acid (3,4-diHBA), and 3-(3-hydroxyphenyl)propionic acid (3-HPPA) that are derived from gut microbiota metabolism of dietary polyphenols, show in vitro ability to effectively modulate α-syn misfolding, oligomerization, and mediate aggregated α-syn neurotoxicity. Here we investigate whether 3-HBA, 4-hydroxybenzoic acid (4-HBA), 3,4-diHBA, or 3-HPPA interfere with α-syn spreading in a cell-based system. Using HEK293 cells overexpressing α-syn-A53T-CFP/YFP, we assessed α-syn seeding activity using Fluorescence Resonance Energy Transfer (FRET) to detect and quantify α-syn aggregation. We demonstrated that 3-HPPA, 3,4-diHBA, 3-HBA, and 4-HBA significantly attenuated intracellular α-syn seeding aggregation. To determine whether our compounds could inhibit brain-derived seeding activity, we utilized insoluble α-syn extracted from post-mortem MSA or PD brain specimens. We found that 3-HPPA effectively attenuated MSA-induced aggregation of monomer into high molecular weight aggregates capable of inducing intracellular aggregation. Outcomes from our studies suggest interactions between gut microbiome and certain dietary factors may form the basis for effective therapies that modulate pathologic α-syn propagation. Collectively, our findings provide the basis for future developments of probiotic, prebiotic, or synbiotic approaches for modulating the onset and/or progression of α-synucleinopathies

    Simulation Training on Extracorporeal Membrane Oxygenation

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    Conventional extracorporeal membrane oxygenation (ECMO) training usually only consists of didactic lectures and water drill of ECMO circuit. However, learners cannot “experience” changes of clinical condition of patients. Simulation-based learning is a perfect answer to this by providing participantsauthentic, interactive, team-based training without risk to real patients. Hospital Authority (HA) of Hong Kong has implemented a corporatewide ECMO simulation-based training program since 2014. It aims to provide a structural and standardized training opportunity for clinical staff members to gain hands-on experience in ECMO circuit management and troubleshooting technique. In the program, participants will go through three categories of scenarios: (1) replicate common real patient clinical experience; (2) replicate incident that only happens infrequently; and (3) imitate clinical situation that is rarely happened but life threatening, and where prompt and correct actions are necessary. Every scenario has its own debriefing session that covers technical and human factor issues.Since 2014, 32 identical full-day courses were conducted and 285 doctors and nurses were trained. All participants were satisfied with the training and expressed that the simulation was an effective model for ECMO training. The training met their need and they could apply what they learned in real-life practice

    Vgf is a novel biomarker associated with muscle weakness in amyotrophic lateral sclerosis (ALS), with a potential role in disease pathogenesis

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    Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. Previous proteomic evidence revealed that the content of certain peptide fragments including Vgf-derived peptide aa 398-411 (Vgf398-411) of the precursor Vgf protein in the cerebral spinal fluid (CSF) correctly identified patients with ALS from normal and disease controls. Using quantitative ELISA immunoassay we found that the CSF levels of Vgf decreases with muscle weakness in patients with ALS. In SOD1 G93A transgenic mice, loss of full-length Vgf content in CSF, serum and in SMI-32 immunopositive spinal cord motor neurons is noted in asymptomatic animals (approximately 75 days old) and continues to show a progressive decline as animals weaken. In vitro studies show that viral-mediated exogenous Vgf expression in primary mixed spinal cord neuron cultures attenuates excitotoxic injury. Thus, while Vgf may be a reliable biomarker of progression of muscle weakness in patients with ALS, restoration of Vgf expression in spinal cord motor neurons may therapeutically rescue spinal cord motorneurons against excitotoxic injury

    Preclinical study of dimebon on β-amyloid-mediated neuropathology in Alzheimer's disease

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    <p>Abstract</p> <p>Background</p> <p>Dimebon is a retired non-selective antihistamine drug currently being investigated as a therapeutic agent for the treatment of Alzheimer's disease (AD). Results from several completed clinical trials are mixed and contradictory. Proper interpretations of these clinical observations, as well as future development of dimebon in AD treatment are complicated by the lack of concrete information on the mechanisms by which dimebon might benefit AD.</p> <p>Results</p> <p>The present studies are designed specifically to assess whether dimebon might modulate β-amyloid (Aβ)-mediated responses which are central to the development and progression of AD dementia. We found that dimebon is bioavailable in the brains of mice following oral administration. AD mice chronically treated with dimebon exhibited a trend of improvement in spatial memory function without affecting the levels of total Aβ as well as soluble oligomeric Aβ in the brain. The same trend of behavior improvement is also seen in wild type animals chronically treated with dimebon.</p> <p>Conclusion</p> <p>Collectively, our preclinical studies using the TgCRND8 AD mouse model demonstrated that dimebon might have some beneficial effect in improving cognitive function independent of Alzheimer's disease-type Aβ-related mechanisms or global energy metabolism in the brain. Observations from our study and others suggesting dimebon might improve cognition in wild type mice and rats raises the possibility that dimebon might be able to benefit cognitive function in patients with other neurodegenerative disorders, such as Huntington's disease, or in the aging population. Additional studies will be necessary to clarify the mechanisms by which dimebon might directly or indirectly benefit cognitive function.</p

    Grape-Seed Polyphenolic Extract Improves the Eye Phenotype in a Drosophila Model of Tauopathy

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    Drosophila models of tauopathies have been developed by transgenically overexpressing the disease-associated forms of tau. In this paper we report for the first time that a recently developed Grape-Seed Polyphenolic Extract (GSPE) improves the eye phenotype of a Drosophila eye model of R406W tau. GSPE-mediated improvements in this distinct in vivo neurodegeneration model for protein misfolding/aggregation suggest that GSPE may have therapeutic value in disorders involving aberrant protein aggregation
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