Showing papers by "Drexel University published in 2010"
TL;DR: This work demonstrates microsupercapacitors with powers per volume that are comparable to electrolytic capacitors, capacitances that are four orders of magnitude higher, and energies per volume higher than conventional supercapacitor.
Abstract: Electrochemical capacitors, also called supercapacitors, store energy in two closely spaced layers with opposing charges, and are used to power hybrid electric vehicles, portable electronic equipment and other devices¹. By offering fast charging and discharging rates, and the ability to sustain millions of ²⁻⁵, electrochemical capacitors bridge the gap between batteries, which offer high energy densities but are slow, and conventional electrolytic capacitors, which are fast but have low energy densities. Here, we demonstrate microsupercapacitors with powers per volume that are comparable to electrolytic capacitors, capacitances that are four orders of magnitude higher, and energies per volume that are an order of magnitude higher. We also measured discharge rates of up to 200 V s⁻¹, which is three orders of magnitude higher than conventional supercapacitors. The microsupercapacitors are produced by the electrophoretic deposition of a several micrometre-thick layer of nanostructured carbon onions⁶‚⁷ with diameters of 6-7 nm. Integration of these nanoparticles in a microdevice with a high surface-to-volume ratio, without the use of organic binders and polymer separators, improves performance because of the ease with which ions can access the active material. Increasing the energy density and discharge rates of supercapacitors will enable them to compete with batteries and conventional electrolytic capacitors in a number of applications.
2,469 citations
Boston Children's Hospital1, University of Washington2, Emory University3, GeneDx4, National Institutes of Health5, University of Utah6, Wellcome Trust Sanger Institute7, Salisbury University8, University of California, San Francisco9, Uppsala University10, University of British Columbia11, Johns Hopkins University School of Medicine12, Drexel University13, University of Groningen14, University of Pennsylvania15, University of California, Santa Cruz16, Brigham and Women's Hospital17, The Centre for Applied Genomics18, Research Triangle Park19, Mayo Clinic20, Katholieke Universiteit Leuven21, University of Chicago22, American College of Medical Genetics23
TL;DR: Chromosomal microarray (CMA) is increasingly utilized for genetic testing of individuals with unexplained developmental delay/intellectual disability (DD/ID), autism spectrum disorders (ASD), or multiple congenital anomalies (MCA).
Abstract: Chromosomal microarray (CMA) is increasingly utilized for genetic testing of individuals with unexplained developmental delay/intellectual disability (DD/ID), autism spectrum disorders (ASD), or multiple congenital anomalies (MCA). Performing CMA and G-banded karyotyping on every patient substantially increases the total cost of genetic testing. The International Standard Cytogenomic Array (ISCA) Consortium held two international workshops and conducted a literature review of 33 studies, including 21,698 patients tested by CMA. We provide an evidence-based summary of clinical cytogenetic testing comparing CMA to G-banded karyotyping with respect to technical advantages and limitations, diagnostic yield for various types of chromosomal aberrations, and issues that affect test interpretation. CMA offers a much higher diagnostic yield (15%–20%) for genetic testing of individuals with unexplained DD/ID, ASD, or MCA than a G-banded karyotype (~3%, excluding Down syndrome and other recognizable chromosomal syndromes), primarily because of its higher sensitivity for submicroscopic deletions and duplications. Truly balanced rearrangements and low-level mosaicism are generally not detectable by arrays, but these are relatively infrequent causes of abnormal phenotypes in this population (<1%). Available evidence strongly supports the use of CMA in place of G-banded karyotyping as the first-tier cytogenetic diagnostic test for patients with DD/ID, ASD, or MCA. G-banded karyotype analysis should be reserved for patients with obvious chromosomal syndromes (e.g., Down syndrome), a family history of chromosomal rearrangement, or a history of multiple miscarriages.
2,294 citations
University of Portsmouth1, Spanish National Research Council2, University of Barcelona3, Princeton University4, University of Arizona5, Johns Hopkins University6, University of Chicago7, Fermilab8, University of Tokyo9, University of Washington10, University of Sussex11, University of Michigan12, University of Edinburgh13, Los Alamos National Laboratory14, Lawrence Berkeley National Laboratory15, Pennsylvania State University16, Massachusetts Institute of Technology17, Drexel University18, Ohio State University19, Case Western Reserve University20
TL;DR: In this article, an almost independent constraint on the ratio of distances D-V(0.275) = 0.1390 +/- 0.0037 (2.7 per cent accuracy), where r(s) is the comoving sound horizon at the baryon-drag epoch, DV(z) equivalent to [(1 + z)D(A)(2)cz/H(z)](1/3), D-A(z), is the angular diameter distance and H(z).
Abstract: The spectroscopic Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) galaxy sample represents the final set of galaxies observed using the original SDSS target selection criteria. We analyse the clustering of galaxies within this sample, including both the luminous red galaxy and main samples, and also include the 2-degree Field Galaxy Redshift Survey data. In total, this sample comprises 893 319 galaxies over 9100 deg(2). Baryon acoustic oscillations (BAO) are observed in power spectra measured for different slices in redshift; this allows us to constrain the distance-redshift relation at multiple epochs. We achieve a distance measure at redshift z = 0.275, of r(s)(z(d))/D-V(0.275) = 0.1390 +/- 0.0037 (2.7 per cent accuracy), where r(s)(z(d)) is the comoving sound horizon at the baryon-drag epoch, D-V(z) equivalent to [(1 + z)(2)D(A)(2)cz/H(z)](1/3), D-A(z) is the angular diameter distance and H(z) is the Hubble parameter. We find an almost independent constraint on the ratio of distances D-V(0.35)/D-V(0.2) = 1.736 +/- 0.065, which is consistent at the 1.1 sigma level with the best-fitting Lambda cold dark matter model obtained when combining our z = 0.275 distance constraint with the Wilkinson Microwave Anisotropy Probe 5-year (WMAP5) data. The offset is similar to that found in previous analyses of the SDSS DR5 sample, but the discrepancy is now of lower significance, a change caused by a revised error analysis and a change in the methodology adopted, as well as the addition of more data. Using WMAP5 constraints on Omega(b)h(2) and Omega(c) h(2), and combining our BAO distance measurements with those from the Union supernova sample, places a tight constraint on Omega(m) = 0.286 +/- 0.018 and H-0 = 68.2 +/- 2.2 km s(-1) Mpc(-1) that is robust to allowing Omega(k) not equal 0 and omega not equal -1. This result is independent of the behaviour of dark energy at redshifts greater than those probed by the BAO and supernova measurements. Combining these data sets with the full WMAP5 likelihood constraints provides tight constraints on both Omega(k) = -0.006 +/- 0.008 and omega = -0.97 +/- 0.10 for a constant dark energy equation of state.
1,814 citations
Stockholm University1, University of California, Berkeley2, Lawrence Berkeley National Laboratory3, Pierre-and-Marie-Curie University4, Colorado College5, University of Colorado Boulder6, University of Utah7, Space Telescope Science Institute8, University of Tokyo9, University of Victoria10, Carnegie Institution for Science11, INAF12, University of Oxford13, Las Cumbres Observatory Global Telescope Network14, University of California, Santa Barbara15, Drexel University16, University of Bonn17, Japan Society for the Promotion of Science18, University of Barcelona19, Texas A&M University20, University of Pittsburgh21
TL;DR: Kowalski et al. as mentioned in this paper reported on work to increase the number of well-measured Type Ia supernovae (SNe Ia) at high redshifts.
Abstract: We report on work to increase the number of well-measured Type Ia supernovae (SNe Ia) at high redshifts. Light curves, including high signal-to-noise HST data, and spectra of six SNe Ia that were discovered during 2001 are presented. Additionally, for the two SNe with z > 1, we present groundbased J-band photometry from Gemini and the VLT. These are among the most distant SNe Ia for which ground based near-IR observations have been obtained. We add these six SNe Ia together with other data sets that have recently become available in the literature to the Union compilation (Kowalski et al. 2008). We have made a number of refinements to the Union analysis chain, the most important ones being the refitting of all light curves with the SALT2 fitter and an improved handling of systematic errors. We call this new compilation, consisting of 557 supernovae, the Union2
1,424 citations
TL;DR: Novel system designs are proposed, consisting of the determination of relay weights and the allocation of transmit power, that maximize the achievable secrecy rate subject to a transmit power constraint, or minimize the transmit powersubject to a secrecy rate constraint.
Abstract: Physical (PHY) layer security approaches for wireless communications can prevent eavesdropping without upper layer data encryption. However, they are hampered by wireless channel conditions: absent feedback, they are typically feasible only when the source-destination channel is better than the source-eavesdropper channel. Node cooperation is a means to overcome this challenge and improve the performance of secure wireless communications. This paper addresses secure communications of one source-destination pair with the help of multiple cooperating relays in the presence of one or more eavesdroppers. Three cooperative schemes are considered: decode-and-forward (DF), amplify-and-forward (AF), and cooperative jamming (CJ). For these schemes, the relays transmit a weighted version of a reencoded noise-free message signal (for DF), a received noisy source signal (for AF), or a common jamming signal (for CJ). Novel system designs are proposed, consisting of the determination of relay weights and the allocation of transmit power, that maximize the achievable secrecy rate subject to a transmit power constraint, or, minimize the transmit power subject to a secrecy rate constraint. For DF in the presence of one eavesdropper, closed-form optimal solutions are derived for the relay weights. For other problems, since the optimal relay weights are difficult to obtain, several criteria are considered leading to suboptimal but simple solutions, i.e., the complete nulling of the message signals at all eavesdroppers (for DF and AF), or the complete nulling of jamming signal at the destination (for CJ). Based on the designed relay weights, for DF in the presence of multiple eavesdroppers, and for CJ in the presence of one eavesdropper, the optimal power allocation is obtained in closed-form; in all other cases the optimal power allocation is obtained via iterative algorithms. Numerical evaluation of the obtained secrecy rate and transmit power results show that the proposed design can significantly improve the performance of secure wireless communications.
1,385 citations
National Heart Foundation of Australia1, University of Toronto2, Cleveland Clinic3, University of Chicago4, University of Alberta5, Inova Fairfax Hospital6, Ochsner Health System7, University of Alabama at Birmingham8, Newcastle upon Tyne Hospitals NHS Foundation Trust9, Ludwig Maximilian University of Munich10, Saint Barnabas Medical Center11, Duke University12, Primary Children's Hospital13, University of Pittsburgh14, University of Utah15, University of Maryland, Baltimore16, University of Vienna17, Stanford University18, University College London19, Washington University in St. Louis20, Loma Linda University21, University of A Coruña22, The Texas Heart Institute23, Katholieke Universiteit Leuven24, Northwestern University25, University of Wisconsin-Madison26, Yeshiva University27, Cincinnati Children's Hospital Medical Center28, University of Colorado Denver29, Drexel University30, University of Pennsylvania31, Mayo Clinic32, St Vincent Hospital33, Papworth Hospital34, Emory University35, Johns Hopkins University36
TL;DR: Institutional Affiliations Chair Costanzo MR: Midwest Heart Foundation, Lombard Illinois, USA Task Force 1 Dipchand A: Hospital for Sick Children, Toronto Ontario, Canada; Starling R: Cleveland Clinic Foundation, Cleveland, Ohio, USA; Starlings R: University of Chicago, Chicago, Illinois,USA; Chan M: university of Alberta, Edmonton, Alberta, Canada ; Desai S: Inova Fairfax Hospital, Fairfax, Virginia, USA.
Abstract: Institutional Affiliations Chair Costanzo MR: Midwest Heart Foundation, Lombard Illinois, USA Task Force 1 Dipchand A: Hospital for Sick Children, Toronto Ontario, Canada; Starling R: Cleveland Clinic Foundation, Cleveland, Ohio, USA; Anderson A: University of Chicago, Chicago, Illinois, USA; Chan M: University of Alberta, Edmonton, Alberta, Canada; Desai S: Inova Fairfax Hospital, Fairfax, Virginia, USA; Fedson S: University of Chicago, Chicago, Illinois, USA; Fisher P: Ochsner Clinic, New Orleans, Louisiana, USA; Gonzales-Stawinski G: Cleveland Clinic Foundation, Cleveland, Ohio, USA; Martinelli L: Ospedale Niguarda, Milano, Italy; McGiffin D: University of Alabama, Birmingham, Alabama, USA; Parisi F: Ospedale Pediatrico Bambino Gesu, Rome, Italy; Smith J: Freeman Hospital, Newcastle upon Tyne, UK Task Force 2 Taylor D: Cleveland Clinic Foundation, Cleveland, Ohio, USA; Meiser B: University of Munich/Grosshaden, Munich, Germany; Baran D: Newark Beth Israel Medical Center, Newark, New Jersey, USA; Carboni M: Duke University Medical Center, Durham, North Carolina, USA; Dengler T: University of Hidelberg, Heidelberg, Germany; Feldman D: Minneapolis Heart Institute, Minneapolis, Minnesota, USA; Frigerio M: Ospedale Niguarda, Milano, Italy; Kfoury A: Intermountain Medical Center, Murray, Utah, USA; Kim D: University of Alberta, Edmonton, Alberta, Canada; Kobashigawa J: Cedar-Sinai Heart Institute, Los Angeles, California, USA; Shullo M: University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Stehlik J: University of Utah, Salt Lake City, Utah, USA; Teuteberg J: University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Uber P: University of Maryland, Baltimore, Maryland, USA; Zuckermann A: University of Vienna, Vienna, Austria. Task Force 3 Hunt S: Stanford University, Palo Alto, California, USA; Burch M: Great Ormond Street Hospital, London, UK; Bhat G: Advocate Christ Medical Center, Oak Lawn, Illinois, USA; Canter C: St. Louis Children Hospital, St. Louis, Missouri, USA; Chinnock R: Loma Linda University Children's Hospital, Loma Linda, California, USA; Crespo-Leiro M: Hospital Universitario A Coruna, La Coruna, Spain; Delgado R: Texas Heart Institute, Houston, Texas, USA; Dobbels F: Katholieke Universiteit Leuven, Leuven, Belgium; Grady K: Northwestern University, Chicago, Illlinois, USA; Kao W: University of Wisconsin, Madison Wisconsin, USA; Lamour J: Montefiore Medical Center, New York, New York, USA; Parry G: Freeman Hospital, Newcastle upon Tyne, UK; Patel J: Cedar-Sinai Heart Institute, Los Angeles, California, USA; Pini D: Istituto Clinico Humanitas, Rozzano, Italy; Pinney S: Mount Sinai Medical Center, New York, New York, USA; Towbin J: Cincinnati Children's Hospital, Cincinnati, Ohio, USA; Wolfel G: University of Colorado, Denver, Colorado, USA Independent Reviewers Delgado D: University of Toronto, Toronto, Ontario, Canada; Eisen H: Drexler University College of Medicine, Philadelphia, Pennsylvania, USA; Goldberg L: University of Pennsylvania, Philadelphia, Pennsylvania, USA; Hosenpud J: Mayo Clinic, Jacksonville, Florida, USA; Johnson M: University of Wisconsin, Madison, Wisconsin, USA; Keogh A: St Vincent Hospital, Sidney, New South Wales, Australia; Lewis C: Papworth Hospital Cambridge, UK; O'Connell J: St. Joseph Hospital, Atlanta, Georgia, USA; Rogers J: Duke University Medical Center, Durham, North Carolina, USA; Ross H: University of Toronto, Toronto, Ontario, Canada; Russell S: Johns Hopkins Hospital, Baltimore, Maryland, USA; Vanhaecke J: University Hospital Gasthuisberg, Leuven, Belgium.
1,346 citations
TL;DR: It is demonstrated that monolithic carbon films lead to a volumetric capacity exceeding that of micro- and macroscale supercapacitors reported thus far, by a factor of 2.5, which provides the framework for integration of high-performance micro-supercapacitor onto a variety of devices.
Abstract: Microbatteries with dimensions of tens to hundreds of micrometers that are produced by common microfabrication techniques are poised to provide integration of power sources onto electronic devices, but they still suffer from poor cycle lifetime, as well as power and temperature range of operation issues that are alleviated with the use of supercapacitors. There have been a few reports on thin-film and other micro-supercapacitors, but they are either too thin to provide sufficient energy or the technology is not scalable. By etching supercapacitor electrodes into conductive titanium carbide substrates, we demonstrate that monolithic carbon films lead to a volumetric capacity exceeding that of micro- and macroscale supercapacitors reported thus far, by a factor of 2. This study also provides the framework for integration of high-performance micro-supercapacitors onto a variety of devices.
1,234 citations
Pennsylvania State University1, Drexel University2, York University3, Princeton University4, University of Washington5, University of Arizona6, Max Planck Society7, University of Southampton8, Johns Hopkins University9, Fermilab10, University of Chicago11, New Mexico State University12, New York University13, University of Tokyo14, Microsoft15, Korea Institute for Advanced Study16, Seoul National University17, National Science Foundation18, Lawrence Berkeley National Laboratory19, Ohio State University20
TL;DR: The fifth edition of the Sloan Digital Sky Survey (SDSS) Quasar catalog as discussed by the authors contains 105,783 spectroscopically confirmed quasars, which is based upon the SDSS Seventh Data Release.
Abstract: We present the fifth edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog, which is based upon the SDSS Seventh Data Release. The catalog, which contains 105,783 spectroscopically confirmed quasars, represents the conclusion of the SDSS-I and SDSS-II quasar survey. The catalog consists of the SDSS objects that have luminosities larger than Mi = –22.0 (in a cosmology with H 0 = 70 km s–1 Mpc–1, Ω M = 0.3, and ΩΛ = 0.7), have at least one emission line with FWHM larger than 1000 km s–1 or have interesting/complex absorption features, are fainter than i 15.0, and have highly reliable redshifts. The catalog covers an area of 9380 deg2. The quasar redshifts range from 0.065 to 5.46, with a median value of 1.49; the catalog includes 1248 quasars at redshifts greater than 4, of which 56 are at redshifts greater than 5. The catalog contains 9210 quasars with i < 18; slightly over half of the entries have i < 19. For each object the catalog presents positions accurate to better than 01 rms per coordinate, five-band (ugriz) CCD-based photometry with typical accuracy of 0.03 mag, and information on the morphology and selection method. The catalog also contains radio, near-infrared, and X-ray emission properties of the quasars, when available, from other large-area surveys. The calibrated digital spectra cover the wavelength region 3800-9200 A at a spectral resolution of 2000; the spectra can be retrieved from the SDSS public database using the information provided in the catalog. Over 96% of the objects in the catalog were discovered by the SDSS. We also include a supplemental list of an additional 207 quasars with SDSS spectra whose archive photometric information is incomplete.
1,110 citations
TL;DR: A review of the current state of the art in observations and dynamical modeling of young massive star clusters can be found in this paper, where the authors focus on star clusters younger than 100$ Myr, more than a few current crossing times old, and more massive than 10^4$Msun.
Abstract: Young massive clusters are dense aggregates of young stars that form the fundamental building blocks of galaxies. Several examples exist in the Milky Way Galaxy and the Local Group, but they are particularly abundant in starburst and interacting galaxies. The few young massive clusters that are close enough to resolve are of prime interest for studying the stellar mass function and the ecological interplay between stellar evolution and stellar dynamics. The distant unresolved clusters may be effectively used to study the star-cluster mass function, and they provide excellent constraints on the formation mechanisms of young cluster populations. Young massive clusters are expected to be the nurseries for many unusual objects, including a wide range of exotic stars and binaries. So far only a few such objects have been found in young massive clusters, although their older cousins, the globular clusters, are unusually rich in stellar exotica. In this review we focus on star clusters younger than $\sim100$ Myr, more than a few current crossing times old, and more massive than $\sim10^4$ \Msun, irrespective of cluster size or environment. We describe the global properties of the currently known young massive star clusters in the Local Group and beyond, and discuss the state of the art in observations and dynamical modeling of these systems. In order to make this review readable by observers, theorists, and computational astrophysicists, we also review the cross-disciplinary terminology.
1,052 citations
American Foundation for Suicide Prevention1, San Francisco State University2, University of California, Los Angeles3, Pennsylvania State University4, University of Colorado Denver5, Columbia University6, University of Illinois at Chicago7, City University of New York8, University of Arizona9, University of California, San Francisco10, Drexel University11, University of Minnesota12, Fenway Health13, Yale University14, University of Pennsylvania15, Ben-Gurion University of the Negev16, University of Pittsburgh17, Howard Brown Health Center18, Kaiser Permanente19
TL;DR: This article is a culmination of a three-year effort by an expert panel to address the need for better understanding of suicidal behavior and suicide risk in sexual minority populations, and stimulate the development of needed prevention strategies, interventions and policy changes.
Abstract: Despite strong indications of elevated risk of suicidal behavior in lesbian, gay, bisexual, and transgender people, limited attention has been given to research, interventions or suicide prevention programs targeting these populations. This article is a culmination of a three-year effort by an expert panel to address the need for better understanding of suicidal behavior and suicide risk in sexual minority populations, and stimulate the development of needed prevention strategies, interventions and policy changes. This article summarizes existing research findings, and makes recommendations for addressing knowledge gaps and applying current knowledge to relevant areas of suicide prevention practice.
1,050 citations
TL;DR: In this article, a multiple-perspective co-citation analysis method is introduced for characterizing and interpreting the structure and dynamics of cocitation clusters, which facilitates analytic and sense-making tasks by integrating network visualization, spectral clustering, automatic cluster labeling, and text summarization.
Abstract: A multiple-perspective co-citation analysis method is introduced for characterizing and interpreting the structure and dynamics of co-citation clusters. The method facilitates analytic and sense making tasks by integrating network visualization, spectral clustering, automatic cluster labeling, and text summarization. Co-citation networks are decomposed into co-citation clusters. The interpretation of these clusters is augmented by automatic cluster labeling and summarization. The method focuses on the interrelations between a co-citation cluster's members and their citers. The generic method is applied to a three-part analysis of the field of Information Science as defined by 12 journals published between 1996 and 2008: 1) a comparative author co-citation analysis (ACA), 2) a progressive ACA of a time series of co-citation networks, and 3) a progressive document co-citation analysis (DCA). Results show that the multiple- perspective method increases the interpretability and accountability of both ACA and DCA networks.
TL;DR: A 2-item FI screen was sensitive, specific, and valid among low-income families with young children, enabling providers to target services that ameliorate the health and developmental consequences associated with FI.
Abstract: OBJECTIVES: To develop a brief screen to identify families at risk for food insecurity (FI) and to evaluate the sensitivity, specificity, and convergent validity of the screen. PATIENTS AND METHODS: Caregivers of children (age: birth through 3 years) from 7 urban medical centers completed the US Department of Agriculture 18-item Household Food Security Survey (HFSS), reports of child health, hospitalizations in their lifetime, and developmental risk. Children were weighed and measured. An FI screen was developed on the basis of affirmative HFSS responses among food-insecure families. Sensitivity and specificity were evaluated. Convergent validity (the correspondence between the FI screen and theoretically related variables) was assessed with logistic regression, adjusted for covariates including study site; the caregivers9 race/ethnicity, US-born versus immigrant status, marital status, education, and employment; history of breastfeeding; child9s gender; and the child9s low birth weight status. RESULTS: The sample included 30 098 families, 23% of which were food insecure. HFSS questions 1 and 2 were most frequently endorsed among food-insecure families (92.5% and 81.9%, respectively). An affirmative response to either question 1 or 2 had a sensitivity of 97% and specificity of 83% and was associated with increased risk of reported poor/fair child health (adjusted odds ratio [aOR]: 1.56; P CONCLUSIONS: A 2-item FI screen was sensitive, specific, and valid among low-income families with young children. The FI screen rapidly identifies households at risk for FI, enabling providers to target services that ameliorate the health and developmental consequences associated with FI.
TL;DR: Results show that the multiple- perspective method increases the interpretability and accountability of both ACA and DCA networks.
Abstract: A multiple-perspective co-citation analysis method is introduced for characterizing and interpreting the structure and dynamics of co-citation clusters. The method facilitates analytic and sense making tasks by integrating network visualization, spectral clustering, automatic cluster labeling, and text summarization. Co-citation networks are decomposed into co-citation clusters. The interpretation of these clusters is augmented by automatic cluster labeling and summarization. The method focuses on the interrelations between a co-citation cluster's members and their citers. The generic method is applied to a three-part analysis of the field of Information Science as defined by 12 journals published between 1996 and 2008: 1) a comparative author co-citation analysis (ACA), 2) a progressive ACA of a time series of co-citation networks, and 3) a progressive document co-citation analysis (DCA). Results show that the multiple-perspective method increases the interpretability and accountability of both ACA and DCA networks.
01 May 2010
TL;DR: The conceptual model argues that individuals' intention to disclose such information depends on their trust, privacy concern, and information sensitivity, which are determined by personal dispositions-personality traits, information sensitivity; and experience-acting as intrinsic antecedents of trust.
Abstract: Reluctance to provide personal health information could impede the success of web-based healthcare services. This paper focuses on the role of personal dispositions in disclosing health information online. The conceptual model argues that individuals' intention to disclose such information depends on their trust, privacy concern, and information sensitivity, which are determined by personal dispositions-personality traits, information sensitivity, health status, prior privacy invasions, risk beliefs, and experience-acting as intrinsic antecedents of trust. The data (collected via a lab experiment) and the analysis shed light on the role of personal dispositions. This could assist in enhancing healthcare websites and increase the success of online delivery of health services.
TL;DR: The authors examine the performance of various CART‐based propensity score models using simulated data and suggest that ensemble methods, especially boosted CART, may be useful for propensity score weighting.
Abstract: Machine learning techniques such as classification and regression trees (CART) have been suggested as promising alternatives to logistic regression for the estimation of propensity scores. The authors examined the performance of various CART-based propensity score models using simulated data. Hypothetical studies of varying sample sizes (n=500, 1000, 2000) with a binary exposure, continuous outcome, and 10 covariates were simulated under seven scenarios differing by degree of non-linear and non-additive associations between covariates and the exposure. Propensity score weights were estimated using logistic regression (all main effects), CART, pruned CART, and the ensemble methods of bagged CART, random forests, and boosted CART. Performance metrics included covariate balance, standard error, per cent absolute bias, and 95 per cent confidence interval (CI) coverage. All methods displayed generally acceptable performance under conditions of either non-linearity or non-additivity alone. However, under conditions of both moderate non-additivity and moderate non-linearity, logistic regression had subpar performance, whereas ensemble methods provided substantially better bias reduction and more consistent 95 per cent CI coverage. The results suggest that ensemble methods, especially boosted CART, may be useful for propensity score weighting.
TL;DR: In this paper, the authors examined herding behavior in global markets and found evidence of herding in advanced stock markets (except the US) and in Asian markets, with the exception of the US and Latin American markets.
Abstract: This paper examines herding behavior in global markets. By applying daily data for 18 countries from May 25, 1988, through April 24, 2009, we find evidence of herding in advanced stock markets (except the US) and in Asian markets. No evidence of herding is found in Latin American markets. Evidence suggests that stock return dispersions in the US play a significant role in explaining the non-US market’s herding activity. With the exceptions of the US and Latin American markets, herding is present in both up and down markets, although herding asymmetry is more profound in Asian markets during rising markets. Evidence suggests that crisis triggers herding activity in the crisis country of origin and then produces a contagion effect, which spreads the crisis to neighboring countries. During crisis periods, we find supportive evidence for herding formation in the US and Latin American markets.
TL;DR: The growth rates of upper extremity arthroplasty were comparable to or higher than rates for total hip and knee procedures, and of particular concern was the increased revision burden.
TL;DR: This article examined the relationships between CEO personality, strategic flexibility, and firm performance, using a sample of 195 small and medium-sized companies with a total workforce of 5,000 employees.
Abstract: We examine the relationships between CEO personality, strategic flexibility (ability to adapt quickly to environmental changes), and firm performance, using a sample of 195 small and medium-sized f...
TL;DR: The current document is an update of an earlier version of single photon emission tomography guidelines that was developed by the American Society of Nuclear Cardiology, and should not be used in clinical studies until they have been reviewed and approved by qualified physicians and technologists from their own particular institutions.
Spanish National Research Council1, University of Barcelona2, Princeton University3, Institute of Cosmology and Gravitation, University of Portsmouth4, University of Arizona5, Catalan Institution for Research and Advanced Studies6, Max Planck Society7, Johns Hopkins University8, Fermilab9, University of Chicago10, University of Tokyo11, University of Washington12, University of Michigan13, University of Edinburgh14, Los Alamos National Laboratory15, Lawrence Berkeley National Laboratory16, Pennsylvania State University17, Massachusetts Institute of Technology18, Drexel University19, Ohio State University20, Case Western Reserve University21
TL;DR: In this article, the power spectrum of the reconstructed halo density field derived from a sample of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS) Seventh Data Release (DR7) was presented.
Abstract: We present the power spectrum of the reconstructed halo density field derived from a sample of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS) Seventh Data Release (DR7). The halo power spectrum has a direct connection to the underlying dark matter power for k≤ 0.2 h Mpc−1, well into the quasi-linear regime. This enables us to use a factor of ∼8 more modes in the cosmological analysis than an analysis with kmax= 0.1 h Mpc−1, as was adopted in the SDSS team analysis of the DR4 LRG sample. The observed halo power spectrum for 0.02 < k < 0.2 h Mpc−1 is well fitted by our model: χ2= 39.6 for 40 degrees of freedom for the best-fitting Λ cold dark matter (ΛCDM) model. We find Ωmh2(ns/0.96)1.2= 0.141+0.101-0.012 for a power-law primordial power spectrum with spectral index ns and Ωbh2= 0.022 65 fixed, consistent with cosmic microwave background measurements. The halo power spectrum also constrains the ratio of the comoving sound horizon at the baryon-drag epoch to an effective distance to z= 0.35: rs/DV(0.35) = 0.1097+0.0039−0.0042. Combining the halo power spectrum measurement with the Wilkinson Microwave Anisotropy Probe (WMAP) 5 year results, for the flat ΛCDM model we find Ωm= 0.289 ± 0.019 and H0= 69.4 ± 1.6 km s−1 Mpc−1. Allowing for massive neutrinos in ΛCDM, we find Σmv <0.62 eV at the 95 per cent confidence level. If we instead consider the effective number of relativistic species Neff as a free parameter, we find Neff= 4.8+1.8−1.7. Combining also with the Kowalski et al. supernova sample, we find Ωtot= 1.011 ± 0.009 and w=−0.99 ± 0.11 for an open cosmology with constant dark energy equation of state w. The power spectrum and a module to calculate the likelihoods are publicly available at http://lambda.gsfc.nasa.gov/toolbox/lrgdr/.
TL;DR: In this paper, the authors investigated the effects of deformation twinning on various aspects of plastic deformation, including the anisotropic strain-hardening rates, the tension/compression yield asymmetry, and the evolution of crystallographic texture.
James Cook University1, North Carolina Wildlife Resources Commission2, University of Hawaii3, Oswaldo Cruz Foundation4, University of Florida5, University of Exeter6, Duke University7, University of Barcelona8, Sapienza University of Rome9, University of Queensland10, Puerto Rico Department of Natural and Environmental Resources11, National Marine Fisheries Service12, University of Canberra13, University of Florence14, University of Paris-Sud15, Swansea University16, National Taiwan Ocean University17, Pamukkale University18, San Diego State University19, California Academy of Sciences20, Indian Institute of Science21, Drexel University22, University of Valencia23, United States Geological Survey24
TL;DR: In this paper, a list of priority research questions was assembled based on the opinions of 35 sea turtle researchers from 13 nations working in fields related to sea turtle biology and/or conservation.
Abstract: Over the past 3 decades, the status of sea turtles and the need for their protection to aid population recovery have increasingly captured the interest of government agencies, non-governmental organisations (NGOs) and the general public worldwide. This interest has been matched by increased research attention, focusing on a wide variety of topics relating to sea turtle biology and ecology, together with the interrelations of sea turtles with the physical and natural environments. Although sea turtles have been better studied than most other marine fauna, management actions and their evaluation are often hindered by the lack of data on turtle biology, human–turtle interactions, turtle population status and threats. In an effort to inform effective sea turtle conservation a list of priority research questions was assembled based on the opinions of 35 sea turtle researchers from 13 nations working in fields related to turtle biology and/or conservation. The combined experience of the contributing researchers spanned the globe as well as many relevant disciplines involved in conservation research. An initial list of more than 200 questions gathered from respondents was condensed into 20 metaquestions and classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies.
TL;DR: Among the population of largely low or asymptomatic HCM patients, the presence of scar indicated by CMR is a good independent predictor of all-cause and cardiac mortality.
TL;DR: Lead extraction employing laser sheaths is highly successful with a low procedural complication rate, particularly in the setting of diabetes, renal insufficiency, or body mass index <25 kg/m(2).
TL;DR: MBSR treatment effects on pain, HRQoL and psychological well-being vary as a function of chronic pain condition and compliance with home meditation practice.
TL;DR: Septin 2 (SEPT2), a member of the septin family of guanosine triphosphatases that form a diffusion barrier in budding yeast, localized at the base of the ciliary membrane and is essential for retaining receptor-signaling pathways in the primary cilium.
Abstract: In animal cells, the primary cilium transduces extracellular signals through signaling receptors localized in the ciliary membrane, but how these ciliary membrane proteins are retained in the cilium is unknown. We found that ciliary membrane proteins were highly mobile, but their diffusion was impeded at the base of the cilium by a diffusion barrier. Septin 2 (SEPT2), a member of the septin family of guanosine triphosphatases that form a diffusion barrier in budding yeast, localized at the base of the ciliary membrane. SEPT2 depletion resulted in loss of ciliary membrane protein localization and Sonic hedgehog signal transduction, and inhibited ciliogenesis. Thus, SEPT2 is part of a diffusion barrier at the base of the ciliary membrane and is essential for retaining receptor-signaling pathways in the primary cilium.
University of California, San Francisco1, Icahn School of Medicine at Mount Sinai2, Harvard University3, University of Miami4, MedStar Washington Hospital Center5, University of Maryland, Baltimore6, University of Pennsylvania7, Rush University Medical Center8, Johns Hopkins University9, University of Chicago10, Emory University11, University of Virginia12, Tulane University13, University of Pittsburgh14, Georgetown University15, Drexel University16, Northwestern University17
TL;DR: In this cohort of carefully selected HIV-infected patients, both patient- and graft-survival rates were high at 1 and 3 years, with no increases in complications associated with HIV infection.
Abstract: Background The outcomes of kidney transplantation and immunosuppression in people infected with human immunodeficiency virus (HIV) are incompletely understood. Methods We undertook a prospective, nonrandomized trial of kidney transplantation in HIV-infected candidates who had CD4+ T-cell counts of at least 200 per cubic millimeter and undetectable plasma HIV type 1 (HIV-1) RNA levels while being treated with a stable antiretroviral regimen. Post-transplantation management was provided in accordance with study protocols that defined prophylaxis against opportunistic infection, indications for biopsy, and acceptable approaches to immunosuppression, management of rejection, and antiretroviral therapy. Results Between November 2003 and June 2009, a total of 150 patients underwent kidney transplantation; survivors were followed for a median period of 1.7 years. Patient survival rates (±SD) at 1 year and 3 years were 94.6±2.0% and 88.2±3.8%, respectively, and the corresponding mean graft-survival rates were 90....
TL;DR: In this article, the co-movements and information transmission among the spot prices of four precious metals (gold, silver, platinum, and palladium), oil price, and the US dollar/euro exchange rate were examined.
TL;DR: The objective of this article is to illustrate the power of spatial models and analytical techniques in the design of wireless networks, and to provide an entry-level tutorial.
Abstract: The performance of wireless networks depends critically on their spatial configuration, because received signal power and interference depend critically on the distances between numerous transmitters and receivers. This is particularly true in emerging network paradigms that may include femtocells, hotspots, relays, white space harvesters, and meshing approaches, which are often overlaid with traditional cellular networks. These heterogeneous approaches to providing high-capacity network access are characterized by randomly located nodes, irregularly deployed infrastructure, and uncertain spatial configurations due to factors like mobility and unplanned user-installed access points. This major shift is just beginning, and it requires new design approaches that are robust to spatial randomness, just as wireless links have long been designed to be robust to fading. The objective of this article is to illustrate the power of spatial models and analytical techniques in the design of wireless networks, and to provide an entry-level tutorial.
TL;DR: This paper surveys and unifies a number of recent contributions that have collectively developed a metric for decentralized wireless network analysis known as transmission capacity and applies it to show how TC can be used to better understand scheduling, power control, and the deployment of multiple antennas in a decentralized network.
Abstract: This paper surveys and unifies a number of recent contributions that have collectively developed a metric for decentralized wireless network analysis known as transmission capacity. Although it is notoriously difficult to derive general end-to-end capacity results for multi-terminal or adhoc networks, the transmission capacity (TC) framework allows for quantification of achievable single-hop rates by focusing on a simplified physical/MAC-layer model. By using stochastic geometry to quantify the multi-user interference in the network, the relationship between the optimal spatial density and success probability of transmissions in the network can be determined, and expressed-often fairly simply-in terms of the key network parameters. The basic model and analytical tools are first discussed and applied to a simple network with path loss only and we present tight upper and lower bounds on transmission capacity (via lower and upper bounds on outage probability). We then introduce random channels (fading/shadowing) and give TC and outage approximations for an arbitrary channel distribution, as well as exact results for the special cases of Rayleigh and Nakagami fading. We then apply these results to show how TC can be used to better understand scheduling, power control, and the deployment of multiple antennas in a decentralized network. The paper closes by discussing shortcomings in the model as well as future research directions.