Showing papers by "Purdue University published in 2007"
15 Apr 2007
TL;DR: T-closeness as mentioned in this paper requires that the distribution of a sensitive attribute in any equivalence class is close to the distributions of the attribute in the overall table (i.e., the distance between the two distributions should be no more than a threshold t).
Abstract: The k-anonymity privacy requirement for publishing microdata requires that each equivalence class (ie, a set of records that are indistinguishable from each other with respect to certain "identifying" attributes) contains at least k records Recently, several authors have recognized that k-anonymity cannot prevent attribute disclosure The notion of l-diversity has been proposed to address this; l-diversity requires that each equivalence class has at least l well-represented values for each sensitive attribute In this paper we show that l-diversity has a number of limitations In particular, it is neither necessary nor sufficient to prevent attribute disclosure We propose a novel privacy notion called t-closeness, which requires that the distribution of a sensitive attribute in any equivalence class is close to the distribution of the attribute in the overall table (ie, the distance between the two distributions should be no more than a threshold t) We choose to use the earth mover distance measure for our t-closeness requirement We discuss the rationale for t-closeness and illustrate its advantages through examples and experiments
3,281 citations
TL;DR: EMAN2 has been under development for the last two years, with a completely refactored image processing library, and a wide range of features to make it much more flexible and extensible than EMAN1.
2,852 citations
TL;DR: In this paper, a review describes the recent progress made in creating nanostructured metamaterials with a negative index at optical wavelengths, and discusses some of the devices that could result from these new materials.
Abstract: Artificially engineered metamaterials are now demonstrating unprecedented electromagnetic properties that cannot be obtained with naturally occurring materials. In particular, they provide a route to creating materials that possess a negative refractive index and offer exciting new prospects for manipulating light. This review describes the recent progress made in creating nanostructured metamaterials with a negative index at optical wavelengths, and discusses some of the devices that could result from these new materials.
2,654 citations
TL;DR: The authors provided a detailed discussion about five qualitative approaches (i.e., narrative research, case study research, grounded theory, phenomenology, and participatory action research) as alternative qualitative procedures useful in understanding test interpretation.
Abstract: Counseling psychologists face many approaches from which to choose when they conduct a qualitative research study. This article focuses on the processes of selecting, contrasting, and implementing five different qualitative approaches. Based on an extended example related to test interpretation by counselors, clients, and communities, this article provides a detailed discussion about five qualitative approaches— narrative research; case study research; grounded theory; phenomenology; and participatory action research—as alternative qualitative procedures useful in understanding test interpretation. For each approach, the authors offer perspectives about historical origins, definition, variants, and the procedures of research.
2,409 citations
TL;DR: A considerable amount of research has examined trust since the 1995 publication of as discussed by the authors, and a number of the critical issues that we addressed and provided clarifications and extensions of the topics of levels of analysis, time, control systems, reciprocity, and measurement.
Abstract: A considerable amount of research has examined trust since our 1995 publication. We revisit some of the critical issues that we addressed and provide clarifications and extensions of the topics of levels of analysis, time, control systems, reciprocity, and measurement. We also recognize recent research in new areas of trust, such as affect, emotion, violation and repair, distrust, international and cross-cultural issues, and context-specific models, and we identify promising avenues for future research.
2,370 citations
TL;DR: This work presents the design of a non-magnetic cloak operating at optical frequencies, and the principle and structure of the proposed cylindrical cloak are analysed and the general recipe for the implementation of such a device is provided.
Abstract: Artificially structured metamaterials have enabled unprecedented flexibility in manipulating electromagnetic waves and producing new functionalities, including the cloak of invisibility based on coordinate transformation1,2,3. Unlike other cloaking approaches4,5,6, which are typically limited to subwavelength objects, the transformation method allows the design of cloaking devices that render a macroscopic object invisible. In addition, the design is not sensitive to the object that is being cloaked. The first experimental demonstration of such a cloak at microwave frequencies was recently reported7. We note, however, that that design7 cannot be implemented for an optical cloak, which is certainly of particular interest because optical frequencies are where the word ‘invisibility’ is conventionally defined. Here we present the design of a non-magnetic cloak operating at optical frequencies. The principle and structure of the proposed cylindrical cloak are analysed, and the general recipe for the implementation of such a device is provided.
1,953 citations
TL;DR: This document reviews various plant feedstuis, which currently are or potentially may be incorporated into aquafeeds to support the sustainable production of various ¢sh species in aquaculture and strategies and techniques to optimize the nutritional composition and limit potentially adverse eiects of bioactive compounds are described.
Abstract: Continued growth and intensi¢cation of aquaculture production depends upon the development of sustainable protein sources to replace ¢sh meal in aquafeeds. This document reviews various plant feedstuis, which currently are or potentially may be incorporated into aquafeeds to support the sustainable production of various ¢sh species in aquaculture. The plant feedstuis considered include oilseeds, legumes and cereal grains, which traditionally have been used as protein or energy concentrates as well as novel products developed through various processing technologies. The nutritional composition of these various feedstuis are considered along with the presence of any bioactive compounds that may positively or negatively aiect the target organism. Lipid composition of these feedstuis is not speci¢cally considered although it is recognized that incorporating lipid supplements in aquafeeds to achieve proper fatty acid pro¢les to meet the metabolic requirements of ¢sh and maximize human health bene¢ts are important aspects. Speci¢c strategies and techniques to optimize the nutritional composition of plant feedstuis and limit potentially adverse eiects of bioactive compounds are also described. Such information will provide a foundation for developing strategic research plans for increasing the use of plant feedstuis in aquaculture to reduce dependence of animal feedstuis and thereby enhance the sustainability of aquaculture.
1,910 citations
TL;DR: The evidence is sufficient to warrant interventions for malaria, intrauterine growth restriction, maternal depression, exposure to violence, and exposure to heavy metals, including iron deficiency anaemia.
1,869 citations
TL;DR: This paper presents an extensive set of duplicate detection algorithms that can detect approximately duplicate records in a database and covers similarity metrics that are commonly used to detect similar field entries.
Abstract: Often, in the real world, entities have two or more representations in databases. Duplicate records do not share a common key and/or they contain errors that make duplicate matching a difficult task. Errors are introduced as the result of transcription errors, incomplete information, lack of standard formats, or any combination of these factors. In this paper, we present a thorough analysis of the literature on duplicate record detection. We cover similarity metrics that are commonly used to detect similar field entries, and we present an extensive set of duplicate detection algorithms that can detect approximately duplicate records in a database. We also cover multiple techniques for improving the efficiency and scalability of approximate duplicate detection algorithms. We conclude with coverage of existing tools and with a brief discussion of the big open problems in the area
1,640 citations
TL;DR: It is striking how phylogenetically distant organisms have come to use similar structures for common purposes in terpenes, and new natural roles undoubtedly remain to be discovered for this large class of compounds.
Abstract: As the largest class of natural products, terpenes have a variety of roles in mediating antagonistic and beneficial interactions among organisms. They defend many species of plants, animals and microorganisms against predators, pathogens and competitors, and they are involved in conveying messages to conspecifics and mutualists regarding the presence of food, mates and enemies. Despite the diversity of terpenes known, it is striking how phylogenetically distant organisms have come to use similar structures for common purposes. New natural roles undoubtedly remain to be discovered for this large class of compounds, given that such a small percentage of terpenes has been investigated so far.
1,602 citations
05 Dec 2007
TL;DR: Body Masses of Birds of the World Body Masses and Composition of Migrant Birds in the Eastern United States Literature Cited Index as discussed by the authors, which is used in this paper.
Abstract: Body Masses of Birds of the World Body Masses and Composition of Migrant Birds in the Eastern United States Literature Cited Index
TL;DR: In this paper, a detailed accounting of the time-series pattern of shipping costs is provided, showing that the ad-valorem impact of ocean shipping costs was not much lower today than in the 1950s, with technological advances largely trumped by adverse cost shocks.
Abstract: While the precise causes of postwar trade growth are not well understood, declines in transport costs top the lists of usual suspects. However, there is remarkably little systematic evidence documenting the decline. This paper brings to bear an eclectic mix of data in order to provide a detailed accounting of the time-series pattern of shipping costs. The ad-valorem impact of ocean shipping costs is not much lower today than in the 1950s, with technological advances largely trumped by adverse cost shocks. In contrast, air shipping costs have dropped an order of magnitude, and airborne trade has grown rapidly as a result. As a result, international trade has also experienced a significant rise in speed.
TL;DR: Dense, perfectly aligned arrays of long, perfectly linear SWNTs are reported as an effective thin-film semiconductor suitable for integration into transistors and other classes of electronic devices, representing a route to large-scale integrated nanotube electronics.
Abstract: †Single-walled carbon nanotubes (SWNTs) have many exceptional electronic properties. Realizing the full potential of SWNTs in realistic electronic systems requires a scalable approach to device and circuit integration. We report the use of dense, perfectly aligned arrays of long, perfectly linear SWNTs as an effective thin-film semiconductor suitable for integration into transistors and other classes of electronic devices. The large number of SWNTs enable excellent device-level performance characteristics and good device-to-device uniformity, even with SWNTs that are electronically heterogeneous. Measurements on p- and n-channel transistors that involve as many as 2,100 SWNTs reveal device-level mobilities and scaled transconductances approaching 1,000 cm 2 V 21 s 21 and 3,000 S m 21 , respectively, and with current outputs of up to 1 A in devices that use interdigitated electrodes. PMOS and CMOS logic gates and mechanically flexible transistors on plastic provide examples of devices that can be formed with this approach. Collectively, these results may represent a route to large-scale integrated nanotube electronics.
J. Craig Venter Institute1, Broad Institute2, Virginia Tech3, Johns Hopkins University4, University of Notre Dame5, Harvard University6, Colorado State University7, Northwestern University8, University of California, Riverside9, University of Oxford10, Purdue University11, Pasteur Institute12, University of São Paulo13, University of Geneva14, University of Massachusetts Amherst15, Instituto Butantan16, University of A Coruña17, University of Göttingen18
TL;DR: A draft sequence of the genome of Aedes aegypti, the primary vector for yellow fever and dengue fever, which at approximately 1376 million base pairs is about 5 times the size of the genomes of the malaria vector Anopheles gambiae was presented in this paper.
Abstract: We present a draft sequence of the genome of Aedes aegypti, the primary vector for yellow fever and dengue fever, which at approximately 1376 million base pairs is about 5 times the size of the genome of the malaria vector Anopheles gambiae. Nearly 50% of the Ae. aegypti genome consists of transposable elements. These contribute to a factor of approximately 4 to 6 increase in average gene length and in sizes of intergenic regions relative to An. gambiae and Drosophila melanogaster. Nonetheless, chromosomal synteny is generally maintained among all three insects, although conservation of orthologous gene order is higher (by a factor of approximately 2) between the mosquito species than between either of them and the fruit fly. An increase in genes encoding odorant binding, cytochrome P450, and cuticle domains relative to An. gambiae suggests that members of these protein families underpin some of the biological differences between the two mosquito species.
TL;DR: In this paper, the authors test for firm-level asset investment effects in returns by examining the cross-sectional relation between firm asset growth and subsequent stock returns using the year-on-year percentage change in total assets.
Abstract: We test for firm-level asset investment effects in returns by examining the cross-sectional relation between firm asset growth and subsequent stock returns. As a test variable, we use the year-on-year percentage change in total assets. Asset growth rates are strong predictors of future abnormal returns. Asset growth retains its forecasting ability even on large capitalization stocks, a subgroup of firms for which other documented predictors of the cross-section lose much of their predictive ability. When we compare asset growth rates with the previously documented determinants of the cross-section of returns (i.e., book-to-market ratios, firm capitalization, lagged returns, accruals, and other growth measures), we find that a firm's annual asset growth rate emerges as an economically and statistically significant predictor of the cross-section of U.S. stock returns.
TL;DR: Besides the heuristically interesting nature of functional selectivity, there is a clear impact on drug discovery, because this mechanism raises the possibility of selecting or designing novel ligands that differentially activate only a subset of functions of a single receptor, thereby optimizing therapeutic action.
Abstract: The concept of intrinsic efficacy has been enshrined in pharmacology for half of a century, yet recent data have revealed that many ligands can differentially activate signaling pathways mediated via a single G protein-coupled receptor in a manner that challenges the traditional definition of intrinsic efficacy. Some terms for this phenomenon include functional selectivity, agonist-directed trafficking, and biased agonism. At the extreme, functionally selective ligands may be both agonists and antagonists at different functions mediated by the same receptor. Data illustrating this phenomenon are presented from serotonin, opioid, dopamine, vasopressin, and adrenergic receptor systems. A variety of mechanisms may influence this apparently ubiquitous phenomenon. It may be initiated by differences in ligand-induced intermediate conformational states, as shown for the β 2 -adrenergic receptor. Subsequent mechanisms that may play a role include diversity of G proteins, scaffolding and signaling partners, and receptor oligomers. Clearly, expanded research is needed to elucidate the proximal (e.g., how functionally selective ligands cause conformational changes that initiate differential signaling), intermediate (mechanisms that translate conformation changes into differential signaling), and distal mechanisms (differential effects on target tissue or organism). Besides the heuristically interesting nature of functional selectivity, there is a clear impact on drug discovery, because this mechanism raises the possibility of selecting or designing novel ligands that differentially activate only a subset of functions of a single receptor, thereby optimizing therapeutic action. It also may be timely to revise classic concepts in quantitative pharmacology and relevant pharmacological conventions to incorporate these new concepts.
TL;DR: Enhanced image resolution and lower noise have been achieved, concurrently with the reduction of helical cone-beam artifacts, as demonstrated by phantom studies and clinical results illustrate the capabilities of the algorithm on real patient data.
Abstract: Multislice helical computed tomography scanning offers the advantages of faster acquisition and wide organ coverage for routine clinical diagnostic purposes. However, image reconstruction is faced with the challenges of three-dimensional cone-beam geometry, data completeness issues, and low dosage. Of all available reconstruction methods, statistical iterative reconstruction (IR) techniques appear particularly promising since they provide the flexibility of accurate physical noise modeling and geometric system description. In this paper, we present the application of Bayesian iterative algorithms to real 3D multislice helical data to demonstrate significant image quality improvement over conventional techniques. We also introduce a novel prior distribution designed to provide flexibility in its parameters to fine-tune image quality. Specifically, enhanced image resolution and lower noise have been achieved, concurrently with the reduction of helical cone-beam artifacts, as demonstrated by phantom studies. Clinical results also illustrate the capabilities of the algorithm on real patient data. Although computational load remains a significant challenge for practical development, superior image quality combined with advancements in computing technology make IR techniques a legitimate candidate for future clinical applications.
TL;DR: In this article, the authors present a detailed analysis of the performance of the Large Hadron Collider (CMS) at 14 TeV and compare it with the state-of-the-art analytical tools.
Abstract: CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider (LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking--through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start-up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb−1 or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, Bs production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb−1 to 30 fb−1. The Standard Model processes include QCD, B-physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z0 boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2-6 describe examples of full analyses, with photons, electrons, muons, jets, missing ET, B-mesons and τ's, and for quarkonia in heavy ion collisions. Chapters 7-15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model
TL;DR: The ICTP Regional Climate Model version 3 (RegCM3) as mentioned in this paper is a state-of-the-art regional climate model, which is used by a large research community for a diverse range of climate-related studies.
Abstract: Regional climate models are important research tools available to scientists around the world, including in economically developing nations (EDNs). The Earth Systems Physics (ESP) group of the Abdus Salam International Centre for Theoretical Physics (ICTP) maintains and distributes a state-of-the-science regional climate model called the ICTP Regional Climate Model version 3 (RegCM3), which is currently being used by a large research community for a diverse range of climate-related studies. The RegCM3 is the central, but not only, tool of the ICTP-maintained Regional Climate Research Network (RegCNET) aimed at creating south–south and north–south scientific interactions on the topic of climate and associated impacts research and modeling. In this paper, RegCNET, RegCM3, and illustrative results from RegCM3 benchmark simulations applied over south Asia, Africa, and South America are presented. It is shown that RegCM3 performs reasonably well over these regions and is therefore useful for climate studies in...
TL;DR: This paper examined whether 5th-grade students' perceptions of the classroom social environment were related to their engagement in the classroom (self-regulation and task-related interaction) and whether those relations were mediated by personal motivational beliefs (mastery goals, academic and social efficacy).
Abstract: This research examined whether 5th-grade students' (N = 602) perceptions of the classroom social environment (teacher support, promotion of mutual respect, promotion of task-related interaction, student support) were related to their engagement in the classroom (self-regulation and task-related interaction) and whether those relations were mediated by personal motivational beliefs (mastery goals, academic and social efficacy). Teacher support, promotion of interaction, and student support were related to both types of engagement, and those relations were fully or partially mediated by motivational beliefs. Relations with promoting mutual respect were not significant.
Harvard University1, Case Western Reserve University2, Baylor College of Medicine3, University of Pittsburgh4, University of Pennsylvania5, University of Texas at San Antonio6, University of Oklahoma7, Stanford University8, University of Massachusetts Medical School9, Oregon Health & Science University10, University of Toledo11, University of Colorado Denver12, University of Colorado Boulder13, Boston University14, Purdue University15
TL;DR: The use of adjunctive, standard antidepressant medication, as compared with the use of mood stabilizers, was not associated with increased efficacy or with increased risk of treatment-emergent affective switch.
Abstract: �Background Episodes of depression are the most frequent cause of disability among patients with bipolar disorder. The effectiveness and safety of standard antidepressant agents for depressive episodes associated with bipolar disorder (bipolar depression) have not been well studied. Our study was designed to determine whether adjunctive antidepressant therapy reduces symptoms of bipolar depression without increasing the risk of mania. Methods In this double-blind, placebo-controlled study, we randomly assigned subjects with bipolar depression to receive up to 26 weeks of treatment with a mood stabilizer plus adjunctive antidepressant therapy or a mood stabilizer plus a matching placebo, under conditions generalizable to routine clinical care. A standardized clinical monitoring form adapted from the mood-disorder modules of the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, was used at all follow-up visits. The primary outcome was the percentage of subjects in each treatment group meeting the criterion for a durable recovery (8 consecutive weeks of euthymia). Secondary effectiveness outcomes and rates of treatment-emergent affective switch (a switch to mania or hypomania early in the course of treatment) were also examined. Results Forty-two of the 179 subjects (23.5%) receiving a mood stabilizer plus adjunctive antidepressant therapy had a durable recovery, as did 51 of the 187 subjects (27.3%) receiving a mood stabilizer plus a matching placebo (P = 0.40). Modest nonsignificant trends favoring the group receiving a mood stabilizer plus placebo were observed across the secondary outcomes. Rates of treatment-emergent affective switch were similar in the two groups. Conclusions The use of adjunctive, standard antidepressant medication, as compared with the use of mood stabilizers, was not associated with increased efficacy or with increased risk of treatment-emergent affective switch. Longer-term outcome studies are needed to fully assess the benefits and risks of antidepressant therapy for bipolar disorder. (ClinicalTrials.gov number, NCT00012558.)
Massachusetts Institute of Technology1, Purdue University2, Michigan State University3, Cornell University4, University of Córdoba (Spain)5, Broad Institute6, Pacific Northwest National Laboratory7, University of Amsterdam8, University of Natural Resources and Life Sciences, Vienna9, Rothamsted Research10, University of Minnesota11, University of Ottawa12, United States Department of Agriculture13, Saint Louis University14, University of Arizona15, University of Tennessee Health Science Center16, National Center for Agricultural Utilization Research17, National Academy of Sciences of Ukraine18, Wageningen University and Research Centre19
TL;DR: The genome of the filamentous fungus Fusarium graminearum, a major pathogen of cultivated cereals, was sequenced and annotated and many highly polymorphic regions contained sets of genes implicated in plant-fungus interactions and were unusually divergent, with higher rates of recombination.
Abstract: We sequenced and annotated the genome of the filamentous fungus Fusarium graminearum, a major pathogen of cultivated cereals. Very few repetitive sequences were detected, and the process of repeat-induced point mutation, in which duplicated sequences are subject to extensive mutation, may partially account for the reduced repeat content and apparent low number of paralogous (ancestrally duplicated) genes. A second strain of F. graminearum contained more than 10,000 single-nucleotide polymorphisms, which were frequently located near telomeres and within other discrete chromosomal segments. Many highly polymorphic regions contained sets of genes implicated in plant-fungus interactions and were unusually divergent, with higher rates of recombination. These regions of genome innovation may result from selection due to interactions of F. graminearum with its plant hosts.
TL;DR: In this article, the authors investigate how food quality is perceived in relation to satisfaction and behavioral intentions in mid-to upscale restaurants and identify which attributes among food-related qualities are critical in improving satisfaction and heightening revisit intention.
Abstract: Food quality seems to be accepted as a fundamental component to satisfy restaurant customers; however, it has been often overlooked in restaurant service quality and satisfaction studies. The primary objective of this study was to investigate how food quality is perceived in relation to satisfaction and behavioral intentions in mid- to upscale restaurants. This study also attempted to identify which attributes among food-related qualities are critical in improving satisfaction and heightening revisit intention. With a structural equation modeling technique, this study shows that overall food quality significantly affects customer satisfaction and behavioral intentions and also revealed that the relationship between food quality and customer behavioral intentions is mediated by satisfaction. Subsequent regression analyses demonstrated that taste and presentation were the two greatest contributors to customer satisfaction and behavioral intentions. Thus, managers should pay attention to the key food quality...
National Center for Atmospheric Research1, Purdue University2, National Oceanic and Atmospheric Administration3, Tohoku University4, National Institute for Environmental Studies5, Nagoya University6, University of Leeds7, Max Planck Society8, Sukachev Institute of Forest9, Commonwealth Scientific and Industrial Research Organisation10, Colorado State University11
TL;DR: Measurements of midday vertical atmospheric CO2 distributions reveal annual-mean vertical CO2 gradients that are inconsistent with atmospheric models that estimate a large transfer of terrestrial carbon from tropical to northern latitudes, suggesting that northern terrestrial uptake of industrial CO2 emissions plays a smaller role than previously thought.
Abstract: Measurements of midday vertical atmospheric CO2 distributions reveal annual-mean vertical CO2 gradients that are inconsistent with atmospheric models that estimate a large transfer of terrestrial carbon from tropical to northern latitudes. The three models that most closely reproduce the observed annual-mean vertical CO2 gradients estimate weaker northern uptake of –1.5 petagrams of carbon per year (Pg C year–1) and weaker tropical emission of +0.1 Pg C year–1 compared with previous consensus estimates of –2.4 and +1.8 Pg C year–1, respectively. This suggests that northern terrestrial uptake of industrial CO2 emissions plays a smaller role than previously thought and that, after subtracting land-use emissions, tropical ecosystems may currently be strong sinks for CO2.
TL;DR: Previous research on engineering student design processes is extended to compare the design behavior of students and expert engineers to support the argument that problem scoping and information gathering are major differences between advanced engineers and students, and important competencies for engineering students to develop.
Abstract: In this paper we report on an in-depth study of engineering design processes. Specifically, we extend our previous research on engineering student design processes to compare the design behavior of students and expert engineers. Nineteen experts from a variety of engineering disciplines and industries each designed a playground in a lab setting, and gave verbal reports of their thoughts during the design task. Measures of their design processes and solution quality were compared to pre-existing data from 26 freshmen and 24 seniors. The experts spent significantly more time on the task overall and in each stage of engineering design, including significantly more time problem scoping. The experts also gathered significantly more information covering more categories. Results support the argument that problem scoping and information gathering are major differences between advanced engineers and students, and important competencies for engineering students to develop. Timeline representations of the expert designers' processes illustrate characteristic distinctions we found and may help students gain insights into their own design processes.
TL;DR: SIZ1-dependent sumoylation of ICE1 may activate and/or stabilize the protein, facilitating expression of CBF3/DREB1A and repression of MYB15, leading to low temperature tolerance.
Abstract: SIZ1 is a SUMO E3 ligase that facilitates conjugation of SUMO to protein substrates. siz1-2 and siz1-3 T-DNA insertion alleles that caused freezing and chilling sensitivities were complemented genetically by expressing SIZ1, indicating that the SIZ1 is a controller of low temperature adaptation in plants. Cold-induced expression of CBF/DREB1, particularly of CBF3/DREB1A, and of the regulon genes was repressed by siz1. siz1 did not affect expression of ICE1, which encodes a MYC transcription factor that is a controller of CBF3/DREB1A. A K393R substitution in ICE1 [ICE1(K393R)] blocked SIZ1-mediated sumoylation in vitro and in protoplasts identifying the K393 residue as the principal site of SUMO conjugation. SIZ1-dependent sumoylation of ICE1 in protoplasts was moderately induced by cold. Sumoylation of recombinant ICE1 reduced polyubiquitination of the protein in vitro. ICE1(K393R) expression in wild-type plants repressed cold-induced CBF3/DREB1A expression and increased freezing sensitivity. Furthermore, expression of ICE1(K393R) induced transcript accumulation of MYB15, which encodes a MYB transcription factor that is a negative regulator of CBF/DREB1. SIZ1-dependent sumoylation of ICE1 may activate and/or stabilize the protein, facilitating expression of CBF3/DREB1A and repression of MYB15, leading to low temperature tolerance.
04 Jul 2007
TL;DR: A deformation invariant representation of surfaces, the GPS embedding, is introduced using the eigenvalues and eigenfunctions of the Laplace-Beltrami differential operator, and the obtained representation is robust to local topology changes.
Abstract: A deformation invariant representation of surfaces, the GPS embedding, is introduced using the eigenvalues and eigenfunctions of the Laplace-Beltrami differential operator. Notably, since the definition of the GPS embedding completely avoids the use of geodesic distances, and is based on objects of global character, the obtained representation is robust to local topology changes. The GPS embedding captures enough information to handle various shape processing tasks as shape classification, segmentation, and correspondence. To demonstrate the practical relevance of the GPS embedding, we introduce a deformation invariant shape descriptor called G2-distributions, and demonstrate their discriminative power, invariance under natural deformations, and robustness.
TL;DR: Kanal and Weinreb as discussed by the authors provide research support for GE Healthcare, Medtronic, and Biotronik, as well as a speaker's bureau of GE Healthcare.
Abstract: E. Kanal is a consultant for, is a member of the speakers bureau of, and provides research support for Bracco Diagnostics and GE Healthcare; is a member of the speakers bureau of and provides research support for Siemens Medical Solutions; and provides research support for Berlex and Medtronic. T. Gilk is a consultant for Mednovus, Inc. J. R. Gimbel provides research support for St. Jude Medical, Medtronic, and Biotronik. J. Nyenhuis is a consultant for and provides research support to Medtronics. J. Weinreb is a consultant and member of the speakers bureau for GE Healthcare.
TL;DR: This review discusses critical issues related to data processing and analysis in proteomics and describes available methods and tools and places special emphasis on the elaboration of results that are supported by sound statistical arguments.
Abstract: The analysis of the large amount of data generated in mass spectrometry-based proteomics experiments represents a significant challenge and is currently a bottleneck in many proteomics projects. In this review we discuss critical issues related to data processing and analysis in proteomics and describe available methods and tools. We place special emphasis on the elaboration of results that are supported by sound statistical arguments.