394 research outputs found

    Supporting Data mining of large databases by visual feedback queries

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    In this paper, we describe a query system that provides visual relevance feedback in querying large databases. Our goal is to support the process of data mining by representing as many data items as possible on the display. By arranging and coloring the data items as pixels according to their relevance for the query, the user gets a visual impression of the resulting data set. Using an interactive query interface, the user may change the query dynamically and receives immediate feedback by the visual representation of the resulting data set. Furthermore, by using multiple windows for different parts of a complex query, the user gets visual feedback for each part of the query and, therefore, may easier understand the overall result. Our system allows to represent the largest amount of data that can be visualized on current display technology, provides valuable feedback in querying the database, and allows the user to find results which, otherwise, would remain hidden in the database

    Chiral sedimentation of extended objects in viscous media

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    We study theoretically the chirality of a generic rigid object's sedimentation in a fluid under gravity in the low Reynolds number regime. We represent the object as a collection of small Stokes spheres or stokeslets, and the gravitational force as a constant point force applied at an arbitrary point of the object. For a generic configuration of stokeslets and forcing point, the motion takes a simple form in the nearly free draining limit where the stokeslet radius is arbitrarily small. In this case, the internal hydrodynamic interactions between stokeslets are weak, and the object follows a helical path while rotating at a constant angular velocity ω\omega about a fixed axis. This ω\omega is independent of initial orientation, and thus constitutes a chiral response for the object. Even though there can be no such chiral response in the absence of hydrodynamic interactions between the stokeslets, the angular velocity obtains a fixed, nonzero limit as the stokeslet radius approaches zero. We characterize empirically how ω\omega depends on the placement of the stokeslets, concentrating on three-stokeslet objects with the external force applied far from the stokeslets. Objects with the largest ω\omega are aligned along the forcing direction. In this case, the limiting ω\omega varies as the inverse square of the minimum distance between stokeslets. We illustrate the prevalence of this robust chiral motion with experiments on small macroscopic objects of arbitrary shape.Comment: 35 pages, 10 figures; Section VII.A redone and other edits made for clarity. Accepted by Phys. Rev.

    Nonlinear System Modeling, Optimal Cam Design, and Advanced System Control for an Electromechanical Engine Valve Drive

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    A cam-based shear force-actuated electromechanical valve drive system offering variable valve timing in internal combustion engines was previously proposed and demonstrated. To transform this concept into a competitive commercial product, several major challenges need to addressed, including the reduction of power consumption, transition time, and size. As shown in this paper, by using nonlinear system modeling, optimizing cam design, and exploring different control strategies, the power consumption has been reduced from 140 to 49 W (65%), the transition time has been decreased from 3.3 to 2.7 ms (18%), and the actuator torque requirement has been cut from 1.33 to 0.30 N·m (77%).Sheila and Emanuel Landsman Foundatio

    From Visualization to Visually Enabled Reasoning

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    Interactive Visualization has been used to study scientific phenomena, analyze data, visualize information, and to explore large amounts of multi-variate data. It enables the human mind to gain novel insights by empowering the human visual system, encompassing the brain and the eyes, to discover properties that were previously unknown. While it is believed that the process of creating interactive visualizations is reasonably well understood, the process of stimulating and enabling human reasoning with the aid of interactive visualization tools is still a highly unexplored field. We hypothesize that visualizations make an impact if they successfully influence a thought process or a decision. Interacting with visualizations is part of this process. We present exemplary cases where visualization was successful in enabling human reasoning, and instances where the interaction with data helped in understanding the data and making a better informed decision. We suggest metrics that help in understanding the evolution of a decision making process. Such a metric would measure the efficiency of the reasoning process, rather than the performance of the visualization system or the user. We claim that the methodology of interactive visualization, which has been studied to a great extent, is now sufficiently mature, and we would like to provide some guidance regarding the evaluation of knowledge gain through visually enabled reasoning. It is our ambition to encourage the reader to take on the next step and move from information visualization to visually enabled reasoning

    Dairy Foods in a Moderate Energy Restricted Diet Do Not Enhance Central Fat, Weight, and Intra-Abdominal Adipose Tissue Losses nor Reduce Adipocyte Size or Inflammatory Markers in Overweight and Obese Adults: A Controlled Feeding Study

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    Background. Research on dairy foods to enhance weight and fat loss when incorporated into a modest weight loss diet has had mixed results. Objective. A 15-week controlled feeding study to determine if dairy foods enhance central fat and weight loss when incorporated in a modest energy restricted diet of overweight and obese adults. Design. A 3-week run-in to establish energy needs; a 12-week 500 kcal/d energy reduction with 71 low-dairy-consuming overweight and obese adults randomly assigned to diets: ≤1 serving dairy/d (low dairy, LD) or ≤4 servings dairy/d (adequate dairy, AD). All foods were weighed and provided by the metabolic kitchen. Weight, fat, intra-abdominal adipose tissue (IAAT), subcutaneous adipose tissue (SAT) macrophage number, SAT inflammatory gene expression, and circulating cytokines were measured. Results. No diet differences were observed in weight, fat, or IAAT loss; nor SAT mRNA expression of inflammation, circulating cytokines, fasting lipids, glucose, or insulin. There was a significant increase (P = 0.02) in serum 25-hydroxyvitamin D in the AD group. Conclusion. Whether increased dairy intake during weight loss results in greater weight and fat loss for individuals with metabolic syndrome deserves investigation. Assessment of appetite, hunger, and satiety with followup on weight regain should be considered

    Geovisual analytics for spatial decision support: Setting the research agenda

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    This article summarizes the results of the workshop on Visualization, Analytics & Spatial Decision Support, which took place at the GIScience conference in September 2006. The discussions at the workshop and analysis of the state of the art have revealed a need in concerted cross‐disciplinary efforts to achieve substantial progress in supporting space‐related decision making. The size and complexity of real‐life problems together with their ill‐defined nature call for a true synergy between the power of computational techniques and the human capabilities to analyze, envision, reason, and deliberate. Existing methods and tools are yet far from enabling this synergy. Appropriate methods can only appear as a result of a focused research based on the achievements in the fields of geovisualization and information visualization, human‐computer interaction, geographic information science, operations research, data mining and machine learning, decision science, cognitive science, and other disciplines. The name ‘Geovisual Analytics for Spatial Decision Support’ suggested for this new research direction emphasizes the importance of visualization and interactive visual interfaces and the link with the emerging research discipline of Visual Analytics. This article, as well as the whole special issue, is meant to attract the attention of scientists with relevant expertise and interests to the major challenges requiring multidisciplinary efforts and to promote the establishment of a dedicated research community where an appropriate range of competences is combined with an appropriate breadth of thinking

    Sheep Models of F508del and G542X Cystic Fibrosis Mutations Show Cellular Responses to Human Therapeutics

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    Cystic Fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. The F508del and G542X are the most common mutations found in US patients, accounting for 86.4% and 4.6% of all mutations, respectively. The F508del causes deletion of the phenylalanine residue at position 508 and is associated with impaired CFTR protein folding. The G542X is a nonsense mutation that introduces a stop codon into the mRNA, thus preventing normal CFTR protein synthesis. Here, we describe the generation of CFTRF508del/F508del and CFTRG542X/G542X lambs using CRISPR/Cas9 and somatic cell nuclear transfer (SCNT). First, we introduced either F508del or G542X mutations into sheep fetal fibroblasts that were subsequently used as nuclear donors for SCNT. The newborn CF lambs develop pathology similar to CFTR−/− sheep and CF patients. Moreover, tracheal epithelial cells from the CFTRF508del/F508del lambs responded to a human CFTR (hCFTR) potentiator and correctors, and those from CFTRG542X/G542X lambs showed modest restoration of CFTR function following inhibition of nonsense-mediated decay (NMD) and aminoglycoside antibiotic treatments. Thus, the phenotype and electrophysiology of these novel models represent an important advance for testing new CF therapeutics and gene therapy to improve the health of patients with this life-limiting disorder

    Effectiveness of Carboplatin and Paclitaxel as First- and Second-Line Treatment in 61 Patients with Metastatic Melanoma

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    BACKGROUND: Patients with metastatic melanoma have a very unfavorable prognosis with few therapeutic options. Based on previous promising experiences within a clinical trial involving carboplatin and paclitaxel a series of advanced metastatic melanoma patients were treated with this combination. METHODS: Data of all patients with cutaneous metastatic melanoma treated with carboplatin and paclitaxel (CP) at our institution between October 2005 and December 2007 were retrospectively evaluated. For all patients a once-every-3-weeks dose-intensified regimen was used. Overall and progression free survival were calculated using the method of Kaplan and Meier. Tumour response was evaluated according to RECIST criteria. RESULTS: 61 patients with cutaneous metastatic melanoma were treated with CP. 20 patients (85% M1c) received CP as first-line treatment, 41 patients (90.2% M1c) had received at least one prior systemic therapy for metastatic disease. Main toxicities were myelosuppression, fatigue and peripheral neuropathy. Partial responses were noted in 4.9% of patients, stable disease in 23% of patients. No complete response was observed. Median progression free survival was 10 weeks. Median overall survival was 31 weeks. Response, progression-free and overall survival were equivalent in first- and second-line patients. 60 patients of 61 died after a median follow up of 7 months. Median overall survival differed for patients with controlled disease (PR+SD) (49 weeks) compared to patients with progressive disease (18 weeks). CONCLUSIONS: Among patients with metastatic melanoma a subgroup achieved disease control under CP therapy which may be associated with a survival benefit. This potential advantage has to be weighed against considerable toxicity. Since response rates and survival were not improved in previously untreated patients compared to pretreated patients, CP should thus not be applied as first-line treatment

    Precision measurement of the electric quadrupole moment of 31Al and determination of the effective proton charge in the sd-shell

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    he electric quadrupole coupling constant of the 31Al ground state is measured to be nu_Q = |eQV_{zz}/h| = 2196(21)kHz using two different beta-NMR (Nuclear Magnetic Resonance) techniques. For the first time, a direct comparison is made between the continuous rf technique and the adiabatic fast passage method. The obtained coupling constants of both methods are in excellent agreement with each other and a precise value for the quadrupole moment of 31Al has been deduced: |Q(31Al)| = 134.0(16) mb. Comparison of this value with large-scale shell-model calculations in the sd and sdpf valence spaces suggests that the 31Al ground state is dominated by normal sd-shell configurations with a possible small contribution of intruder states. The obtained value for |Q(31Al)| and a compilation of measured quadrupole moments of odd-Z even-N isotopes in comparison with shell-model calculations shows that the proton effective charge e_p=1.1 e provides a much better description of the nuclear properties in the sd-shell than the adopted value e_p=1.3 e

    The causal role of breakfast in energy balance and health: a randomized controlled trial in obese adults

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    Background: The causal nature of associations between breakfast and health remain unclear in obese individuals. Objective: We sought to conduct a randomized controlled trial to examine causal links between breakfast habits and components of energy balance in free-living obese humans. Design: The Bath Breakfast Project is a randomized controlled trial with repeated measures at baseline and follow-up among a cohort in South West England aged 21–60 y with dual-energy X-ray absorptiometry–derived fat mass indexes of 13kg/m2forwomen(n=15)and13 kg/m2 for women (n = 15) and 9 kg/m2 for men (n = 8). Components of energy balance (resting metabolic rate, physical activity thermogenesis, diet-induced thermogenesis, and energy intake) were measured under free-living conditions with random allocation to daily breakfast ($700 kcal before 1100) or extended fasting (0 kcal until 1200) for 6 wk, with baseline and follow up measures of health markers (e.g., hematology/adipose biopsies). Results: Breakfast resulted in greater physical activity thermogenesis during the morning than when fasting during that period (difference: 188 kcal/d; 95% CI: 40, 335) but without any consistent effect on 24-h physical activity thermogenesis (difference: 272 kcal/d; 95% CI: 2254, 798). Energy intake was not significantly greater with breakfast than fasting (difference: 338 kcal/d; 95% CI: 2313, 988). Body mass increased across both groups over time but with no treatment effects on body composition or any change in resting metabolic rate (stable within 8 kcal/d). Metabolic/cardiovascular health also did not respond to treatments, except for a reduced insulinemic response to an oral-glucose-tolerance test over time with daily breakfast relative to an increase with daily fasting (P = 0.05). Conclusions: In obese adults, daily breakfast leads to greater physical activity during the morning, whereas morning fasting results in partial dietary compensation (i.e., greater energy intake) later in the day. There were no differences between groups in weight change and most health outcomes, but insulin sensitivity increased with breakfast relative to fasting
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