Showing papers by "University of Chicago published in 2006"
TL;DR: In this article, a simple cosmological model with only six parameters (matter density, Omega_m h^2, baryon density, BH density, Hubble Constant, H_0, amplitude of fluctuations, sigma_8, optical depth, tau, and a slope for the scalar perturbation spectrum, n_s) was proposed to fit the three-year WMAP temperature and polarization data.
Abstract: A simple cosmological model with only six parameters (matter density, Omega_m h^2, baryon density, Omega_b h^2, Hubble Constant, H_0, amplitude of fluctuations, sigma_8, optical depth, tau, and a slope for the scalar perturbation spectrum, n_s) fits not only the three year WMAP temperature and polarization data, but also small scale CMB data, light element abundances, large-scale structure observations, and the supernova luminosity/distance relationship. Using WMAP data only, the best fit values for cosmological parameters for the power-law flat LCDM model are (Omega_m h^2, Omega_b h^2, h, n_s, tau, sigma_8) = 0.1277+0.0080-0.0079, 0.02229+-0.00073, 0.732+0.031-0.032, 0.958+-0.016, 0.089+-0.030, 0.761+0.049-0.048). The three year data dramatically shrink the allowed volume in this six dimensional parameter space. Assuming that the primordial fluctuations are adiabatic with a power law spectrum, the WMAP data_alone_ require dark matter, and favor a spectral index that is significantly less than the Harrison-Zel'dovich-Peebles scale-invariant spectrum (n_s=1, r=0). Models that suppress large-scale power through a running spectral index or a large-scale cut-off in the power spectrum are a better fit to the WMAP and small scale CMB data than the power-law LCDM model: however, the improvement in the fit to the WMAP data is only Delta chi^2 = 3 for 1 extra degree of freedom. The combination of WMAP and other astronomical data yields significant constraints on the geometry of the universe, the equation of state of the dark energy, the gravitational wave energy density, and neutrino properties. Consistent with the predictions of simple inflationary theories, we detect no significant deviations from Gaussianity in the CMB maps.
6,002 citations
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TL;DR: It is shown that emotional reactions to risky situations often diverge from cognitive assessments of those risks, and when such divergence occurs, emotional reactions often drive behavior.
Abstract: Virtually all current theories of choice under risk or uncertainty are cognitive and consequentialist. They assume that people assess the desirability and likelihood of possible outcomes of choice alternatives and integrate this information through some type of expectation-based calculus to arrive at decision. The authors propose an alternative theoretical perspective, the risk-as-feelings hypothesis, that highlights the role of affect experienced at the moment of decision making. Drawing on research from clinical, physiological, and other subfield of psychology, they show that emotional reactions to risky situations often drive behavior. The risk-as-feelings hypothesis is shown to explain a wide range of phenomena that have resisted interpretation in cognitive-consequentialist terms.
4,901 citations
TL;DR: A first-generation CNV map of the human genome is constructed through the study of 270 individuals from four populations with ancestry in Europe, Africa or Asia, underscoring the importance of CNV in genetic diversity and evolution and the utility of this resource for genetic disease studies.
Abstract: Copy number variation (CNV) of DNA sequences is functionally significant but has yet to be fully ascertained. We have constructed a first-generation CNV map of the human genome through the study of 270 individuals from four populations with ancestry in Europe, Africa or Asia (the HapMap collection). DNA from these individuals was screened for CNV using two complementary technologies: single-nucleotide polymorphism (SNP) genotyping arrays, and clone-based comparative genomic hybridization. A total of 1,447 copy number variable regions (CNVRs), which can encompass overlapping or adjacent gains or losses, covering 360 megabases (12% of the genome) were identified in these populations. These CNVRs contained hundreds of genes, disease loci, functional elements and segmental duplications. Notably, the CNVRs encompassed more nucleotide content per genome than SNPs, underscoring the importance of CNV in genetic diversity and evolution. The data obtained delineate linkage disequilibrium patterns for many CNVs, and reveal marked variation in copy number among populations. We also demonstrate the utility of this resource for genetic disease studies.
4,275 citations
TL;DR: It is shown that bacterial communities of deep water masses of the North Atlantic and diffuse flow hydrothermal vents are one to two orders of magnitude more complex than previously reported for any microbial environment.
Abstract: The evolution of marine microbes over billions of years predicts that the composition of microbial communities should be much greater than the published estimates of a few thousand distinct kinds of microbes per liter of seawater. By adopting a massively parallel tag sequencing strategy, we show that bacterial communities of deep water masses of the North Atlantic and diffuse flow hydrothermal vents are one to two orders of magnitude more complex than previously reported for any microbial environment. A relatively small number of different populations dominate all samples, but thousands of low-abundance populations account for most of the observed phylogenetic diversity. This "rare biosphere" is very ancient and may represent a nearly inexhaustible source of genomic innovation. Members of the rare biosphere are highly divergent from each other and, at different times in earth's history, may have had a profound impact on shaping planetary processes.
3,535 citations
Oregon Health & Science University1, Newcastle University2, Novartis3, University of Texas MD Anderson Cancer Center4, University of Düsseldorf5, Leipzig University6, Cornell University7, National Institutes of Health8, Harvard University9, University of Barcelona10, Heidelberg University11, Wake Forest University12, Icahn School of Medicine at Mount Sinai13, University of Paris14, University of Bordeaux15, Erasmus University Rotterdam16, Royal Adelaide Hospital17, Medical University of Vienna18, University of Mainz19, Katholieke Universiteit Leuven20, University of British Columbia21, University of Basel22, Aarhus University23, Fred Hutchinson Cancer Research Center24, Uppsala University25, Mater Health Services26, University of Bologna27, University of Chicago28
TL;DR: After 5 years of follow-up, continuous treatment of chronic-phase CML with imatinib as initial therapy was found to induce durable responses in a high proportion of patients.
Abstract: BACKGROUND: The cause of chronic myeloid leukemia (CML) is a constitutively active BCR-ABL tyrosine kinase. Imatinib inhibits this kinase, and in a short-term study was superior to interferon alfa ...
3,351 citations
TL;DR: Initial results for a tetraplegic human using a pilot NMP suggest that NMPs based upon intracortical neuronal ensemble spiking activity could provide a valuable new neurotechnology to restore independence for humans with paralysis.
Abstract: Neuromotor prostheses (NMPs) aim to replace or restore lost motor functions in paralysed humans by routeing movement-related signals from the brain, around damaged parts of the nervous system, to external effectors. To translate preclinical results from intact animals to a clinically useful NMP, movement signals must persist in cortex after spinal cord injury and be engaged by movement intent when sensory inputs and limb movement are long absent. Furthermore, NMPs would require that intention-driven neuronal activity be converted into a control signal that enables useful tasks. Here we show initial results for a tetraplegic human (MN) using a pilot NMP. Neuronal ensemble activity recorded through a 96-microelectrode array implanted in primary motor cortex demonstrated that intended hand motion modulates cortical spiking patterns three years after spinal cord injury. Decoders were created, providing a ‘neural cursor’ with which MN opened simulated e-mail and operated devices such as a television, even while conversing. Furthermore, MN used neural control to open and close a prosthetic hand, and perform rudimentary actions with a multi-jointed robotic arm. These early results suggest that NMPs based upon intracortical neuronal ensemble spiking activity could provide a valuable new neurotechnology to restore independence for humans with paralysis. The cover shows Matt Nagle, first participant in the BrainGate pilot clinical trial. He is unable to move his arms or legs following cervical spinal cord injury. Researchers at the Department of Neuroscience at Brown University, working with biotech company Cyberkinetics and 3 other institutions, demonstrate that movement-related signals can be relayed from the brain via an implanted BrainGate chip, allowing the patient to drive a computer screen cursor and activate simple robotic devices. Such neuromotor prostheses could pave the way towards systems to replace or restore lost motor function in paralysed humans. Prior to this advance, this type of work has been performed chiefly in monkeys. The latest example of such research has achieved a large increase in speed over current devices, enhancing the prospects for clinically viable brain-machine interfaces.
3,120 citations
University of Pittsburgh1, Cedars-Sinai Medical Center2, Johns Hopkins University School of Medicine3, Johns Hopkins University4, Université de Montréal5, Broad Institute6, University of Toronto7, Harvard University8, University of Chicago9, McGill University10, North Shore-LIJ Health System11, Yale University12
TL;DR: A highly significant association is found between Crohn's disease and the IL23R gene on chromosome 1p31, which encodes a subunit of the receptor for the proinflammatory cytokine interleukin-23, which prioritize this signaling pathway as a therapeutic target in inflammatory bowel disease.
Abstract: The inflammatory bowel diseases Crohn's disease and ulcerative colitis are common, chronic disorders that cause abdominal pain, diarrhea, and gastrointestinal bleeding. To identify genetic factors that might contribute to these disorders, we performed a genome-wide association study. We found a highly significant association between Crohn's disease and the IL23R gene on chromosome 1p31, which encodes a subunit of the receptor for the proinflammatory cytokine interleukin-23. An uncommon coding variant (rs11209026, c.1142G>A, p.Arg381Gln) confers strong protection against Crohn's disease, and additional noncoding IL23R variants are independently associated. Replication studies confirmed IL23R associations in independent cohorts of patients with Crohn's disease or ulcerative colitis. These results and previous studies on the proinflammatory role of IL-23 prioritize this signaling pathway as a therapeutic target in inflammatory bowel disease.
2,937 citations
TL;DR: Reconstructed time lines, causes, and consequences of change in 12 once diverse and productive estuaries and coastal seas worldwide show similar patterns: Human impacts have depleted >90% of formerly important species, destroyed >65% of seagrass and wetland habitat, degraded water quality, and accelerated species invasions.
Abstract: Estuarine and coastal transformation is as old as civilization yet has dramatically accelerated over the past 150 to 300 years. Reconstructed time lines, causes, and consequences of change in 12 once diverse and productive estuaries and coastal seas worldwide show similar patterns: Human impacts have depleted >90% of formerly important species, destroyed >65% of seagrass and wetland habitat, degraded water quality, and accelerated species invasions. Twentieth-century conservation efforts achieved partial recovery of upper trophic levels but have so far failed to restore former ecosystem structure and function. Our results provide detailed historical baselines and quantitative targets for ecosystem-based management and marine conservation.
2,795 citations
TL;DR: A set of SNPs is developed that can be used to tag the strongest ∼250 signals of recent selection in each population, and it is found that by some measures the authors' strongest signals of selection are from the Yoruba population.
Abstract: The identification of signals of very recent positive selection provides information about the adaptation of modern humans to local conditions. We report here on a genome-wide scan for signals of very recent positive selection in favor of variants that have not yet reached fixation. We describe a new analytical method for scanning single nucleotide polymorphism (SNP) data for signals of recent selection, and apply this to data from the International HapMap Project. In all three continental groups we find widespread signals of recent positive selection. Most signals are region-specific, though a significant excess are shared across groups. Contrary to some earlier low resolution studies that suggested a paucity of recent selection in sub-Saharan Africans, we find that by some measures our strongest signals of selection are from the Yoruba population. Finally, since these signals indicate the existence of genetic variants that have substantially different fitnesses, they must indicate loci that are the source of significant phenotypic variation. Though the relevant phenotypes are generally not known, such loci should be of particular interest in mapping studies of complex traits. For this purpose we have developed a set of SNPs that can be used to tag the strongest ∼250 signals of recent selection in each population.
2,606 citations
TL;DR: The Sloan Digital Sky Survey (SDS) as discussed by the authors is a two-corrector Ritchey-Chretien design with a 2.5 m, f/2.25 m, a 1.08 m secondary, and one of a pair of interchangeable highly aspheric correctors near the focal plane, one for imaging and the other for spectroscopy.
Abstract: We describe the design, construction, and performance of the Sloan Digital Sky Survey telescope located at Apache Point Observatory. The telescope is a modified two-corrector Ritchey-Chretien design with a 2.5 m, f/2.25 primary, a 1.08 m secondary, a Gascoigne astigmatism corrector, and one of a pair of interchangeable highly aspheric correctors near the focal plane, one for imaging and the other for spectroscopy. The final focal ratio is f/5. The telescope is instrumented by a wide-area, multiband CCD camera and a pair of fiber-fed double spectrographs. Novel features of the telescope include the following: (1) A 3° diameter (0.65 m) focal plane that has excellent image quality and small geometric distortions over a wide wavelength range (3000-10,600 A) in the imaging mode, and good image quality combined with very small lateral and longitudinal color errors in the spectroscopic mode. The unusual requirement of very low distortion is set by the demands of time-delay-and-integrate (TDI) imaging. (2) Very high precision motion to support open-loop TDI observations. (3) A unique wind baffle/enclosure construction to maximize image quality and minimize construction costs. The telescope had first light in 1998 May and began regular survey operations in 2000.
2,264 citations
TL;DR: This paper introduced culturally-based explanations into economics that can be tested and may substantially enrich our understanding of economic phenomena, and summarized this approach and its achievements so far, and outlines directions for future research.
Abstract: Until recently, economists have been reluctant to rely on culture as a possible determinant of economic phenomena. Much of this reluctance stems from the very notion of culture: it is so broad and the channels through which it can enter the economic discourse so ubiquitous (and vague) that it is difficult to design testable, refutable hypotheses. In recent years, however, better techniques and more data have made it possible to identify systematic differences in people's preferences and beliefs and to relate them to various measures of cultural legacy. These developments suggest an approach to introducing culturally-based explanations into economics that can be tested and may substantially enrich our understanding of economic phenomena. This paper summarizes this approach and its achievements so far, and outlines directions for future research.
TL;DR: This article showed that the import of new product varieties has contributed to national welfare gains in the United States over the last three decades (1972-2001) by increasing the number of imported product varieties by a factor of four.
Abstract: Since the seminal work of Krugman (1979), product variety has played a central role in models of trade and growth. In spite of the general use of love-of-variety models, there has been no systematic study of how the import of new varieties has contributed to national welfare gains in the United States. In this paper we show that the unmeasured growth in product variety from US imports has been an important source of gains from trade over the last three decades (1972-2001). Using extremely disaggregated data, we show that the number of imported product varieties has increased by a factor of four. We also estimate the elasticities of substitution for each available category at the same level of aggregation, and describe their behavior across time and SITC-5 industries. Using these estimates we develop an exact price index and find that the upward bias in the conventional import price index is approximately 1.2 percent per year – double the estimated impact due to hedonic adjustments on the CPI. The magnitude of this bias suggests that the welfare gains from variety growth in imports alone are 2.8 percent of GDP per year.
TL;DR: It is suggested that loneliness and depressive symptomatology can act in a synergistic effect to diminish well-being in middle-aged and older adults.
Abstract: The extent to which loneliness is a unique risk factor for depressive symptoms was determined in 2 population-based studies of middle-aged to older adults, and the possible causal influences between loneliness and depressive symptoms were examined longitudinally in the 2nd study. In Study 1, a nationally representative sample of persons aged 54 and older completed a telephone interview as part of a study of health and aging. Higher levels of loneliness were associated with more depressive symptoms, net of the effects of age, gender, ethnicity, education, income, marital status, social support, and perceived stress. In Study 2, detailed measures of loneliness, social support, perceived stress, hostility, and demographic characteristics were collected over a 3-year period from a population-based sample of adults ages 50-67 years from Cook County, Illinois. Loneliness was again associated with more depressive symptoms, net of demographic covariates, marital status, social support, hostility, and perceived stress. Latent variable growth models revealed reciprocal influences over time between loneliness and depressive symptomatology. These data suggest that loneliness and depressive symptomatology can act in a synergistic effect to diminish well-being in middle-aged and older adults.
TL;DR: Fundamental and applied research in chemistry and biology benefits from opportunities provided by droplet-based microfluidic systems, which enable the miniaturization of reactions by compartmentalizing reactions in droplets of femoliter to microliter volumes.
Abstract: Fundamental and applied research in chemistry and biology benefits from opportunities provided by droplet-based microfluidic systems. These systems enable the miniaturization of reactions by compartmentalizing reactions in droplets of femoliter to microliter volumes. Compartmentalization in droplets provides rapid mixing of reagents, control of the timing of reactions on timescales from milliseconds to months, control of interfacial properties, and the ability to synthesize and transport solid reagents and products. Droplet-based microfluidics can help to enhance and accelerate chemical and biochemical screening, protein crystallization, enzymatic kinetics, and assays. Moreover, the control provided by droplets in microfluidic devices can lead to new scientific methods and insights.
TL;DR: Adalimumab was superior to placebo for induction of remission in patients with moderate to severe Crohn's disease naive to anti-TNF therapy and was well tolerated.
TL;DR: Algorithmic techniques are presented that substantially improve the running time of the loopy belief propagation approach and reduce the complexity of the inference algorithm to be linear rather than quadratic in the number of possible labels for each pixel, which is important for problems such as image restoration that have a large label set.
Abstract: Markov random field models provide a robust and unified framework for early vision problems such as stereo and image restoration. Inference algorithms based on graph cuts and belief propagation have been found to yield accurate results, but despite recent advances are often too slow for practical use. In this paper we present some algorithmic techniques that substantially improve the running time of the loopy belief propagation approach. One of the techniques reduces the complexity of the inference algorithm to be linear rather than quadratic in the number of possible labels for each pixel, which is important for problems such as image restoration that have a large label set. Another technique speeds up and reduces the memory requirements of belief propagation on grid graphs. A third technique is a multi-grid method that makes it possible to obtain good results with a small fixed number of message passing iterations, independent of the size of the input images. Taken together these techniques speed up the standard algorithm by several orders of magnitude. In practice we obtain results that are as accurate as those of other global methods (e.g., using the Middlebury stereo benchmark) while being nearly as fast as purely local methods.
TL;DR: In this article, the authors examine whether and how accounting information about a firm manifests in its cost of capital, despite the forces of diversification, and demonstrate that the quality of accounting information can influence the costs of capital both directly and indirectly.
Abstract: In this paper we examine whether and how accounting information about a firm manifests in its cost of capital, despite the forces of diversification. We build a model that is consistent with the CAPM and explicitly allows for multiple securities whose cash flows are correlated. We demonstrate that the quality of accounting information can influence the cost of capital, both directly and indirectly. The direct effect occurs because higher quality disclosures reduce the firm's assessed covariances with other firms' cash flows, which is non-diversifiable. The indirect effect occurs because higher quality disclosures affect a firm's real decisions, which likely changes the firm's ratio of the expected future cash flows to the covariance of these cash flows with the sum of all the cash flows in the market. We show that this effect can go in either direction, but also derive conditions under which an increase in information quality leads to an unambiguous decline the cost of capital.
TL;DR: In this paper, the authors study the effect of market entry regulations on the creation of new limited-liability firms, the average size of entrants, and the growth of incumbent firms.
Massachusetts Institute of Technology1, University of Arizona2, Princeton University3, Ohio State University4, New York University5, University of Chicago6, Fermilab7, University of Tokyo8, University of Colorado Boulder9, University of Portsmouth10, Lawrence Berkeley National Laboratory11, Pennsylvania State University12, International Centre for Theoretical Physics13, Johns Hopkins University14, Drexel University15, Case Western Reserve University16, Los Alamos National Laboratory17, University of Washington18, University of Cape Town19, New Mexico State University20, University of Pittsburgh21, Eötvös Loránd University22, Harvard University23, United States Department of the Navy24, University of Pennsylvania25, California Institute of Technology26, University of Sussex27, Seoul National University28, Rochester Institute of Technology29, Hungarian Academy of Sciences30
TL;DR: In this paper, the authors employed a matrix-based power spectrum estimation method using pseudo-Karhunen-Loeve eigenmodes, producing uncorrelated minimum-variance measurements in 20 k-bands of both the clustering power and its anisotropy due to redshift-space distortions.
Abstract: We measure the large-scale real-space power spectrum P(k) using luminous red galaxies (LRGs) in the Sloan Digital Sky Survey (SDSS) and use this measurement to sharpen constraints on cosmological parameters from the Wilkinson Microwave Anisotropy Probe (WMAP). We employ a matrix-based power spectrum estimation method using Pseudo-Karhunen-Loeve eigenmodes, producing uncorrelated minimum-variance measurements in 20 k-bands of both the clustering power and its anisotropy due to redshift-space distortions, with narrow and well-behaved window functions in the range 0.01h/Mpc 0.1h/Mpc and associated nonlinear complications, yet agree well with more aggressive published analyses where nonlinear modeling is crucial.
TL;DR: In this paper, gas and total mass profiles for 13 low-redshift, relaxed clusters spanning a temperature range 0.7-9 keV were derived from all available Chandra data of sufficient quality.
Abstract: We present gas and total mass profiles for 13 low-redshift, relaxed clusters spanning a temperature range 0.7-9 keV, derived from all available Chandra data of sufficient quality. In all clusters, gas-temperature profiles are measured to large radii (Vikhlinin et al.) so that direct hydrostatic mass estimates are possible to nearly r500 or beyond. The gas density was accurately traced to larger radii; its profile is not described well by a beta model, showing continuous steepening with radius. The derived ρtot profiles and their scaling with mass generally follow the Navarro-Frenk-White model with concentration expected for dark matter halos in ΛCDM cosmology. However, in three cool clusters, we detect a central mass component in excess of the Navarro-Frenk-White profile, apparently associated with their cD galaxies. In the inner region (r < 0.1r500), the gas density and temperature profiles exhibit significant scatter and trends with mass, but they become nearly self-similar at larger radii. Correspondingly, we find that the slope of the mass-temperature relation for these relaxed clusters is in good agreement with the simple self-similar behavior, M500 Tα, where α = (1.5-1.6) ± 0.1, if the gas temperatures are measured excluding the central cool cores. The normalization of this M-T relation is significantly, by ≈30%, higher than most previous X-ray determinations. We derive accurate gas mass fraction profiles, which show an increase with both radius and cluster mass. The enclosed fgas profiles within r2500 0.4r500 have not yet reached any asymptotic value and are still far (by a factor of 1.5-2) from the universal baryon fraction according to the cosmic microwave background (CMB) observations. The fgas trends become weaker and its values closer to universal at larger radii, in particular, in spherical shells r2500 < r < r500.
TL;DR: Among more severely depressed patients, behavioral activation was comparable to antidepressant medication, and both significantly outperformed cognitive therapy, and the implications of current treatment guidelines and dissemination are discussed.
Abstract: Antidepressant medication is considered the current standard for severe depression, and cognitive therapy is the most widely investigated psychosocial treatment for depression. However, not all patients want to take medication, and cognitive therapy has not demonstrated consistent efficacy across trials. Moreover, dismantling designs have suggested that behavioral components may account for the efficacy of cognitive therapy. The present study tested the efficacy of behavioral activation by comparing it with cognitive therapy and antidepressant medication in a randomized placebo-controlled design in adults with major depressive disorder (N = 241). In addition, it examined the importance of initial severity as a moderator of treatment outcome. Among more severely depressed patients, behavioral activation was comparable to antidepressant medication, and both significantly outperformed cognitive therapy. The implications of these findings for the evaluation of current treatment guidelines and dissemination are discussed.
TL;DR: This study validates the "breast tumor intrinsic" subtype classification as an objective means of tumor classification that should be translated into a clinical assay for further retrospective and prospective validation.
Abstract: Validation of a novel gene expression signature in independent data sets is a critical step in the development of a clinically useful test for cancer patient risk-stratification. However, validation is often unconvincing because the size of the test set is typically small. To overcome this problem we used publicly available breast cancer gene expression data sets and a novel approach to data fusion, in order to validate a new breast tumor intrinsic list. A 105-tumor training set containing 26 sample pairs was used to derive a new breast tumor intrinsic gene list. This intrinsic list contained 1300 genes and a proliferation signature that was not present in previous breast intrinsic gene sets. We tested this list as a survival predictor on a data set of 311 tumors compiled from three independent microarray studies that were fused into a single data set using Distance Weighted Discrimination. When the new intrinsic gene set was used to hierarchically cluster this combined test set, tumors were grouped into LumA, LumB, Basal-like, HER2+/ER-, and Normal Breast-like tumor subtypes that we demonstrated in previous datasets. These subtypes were associated with significant differences in Relapse-Free and Overall Survival. Multivariate Cox analysis of the combined test set showed that the intrinsic subtype classifications added significant prognostic information that was independent of standard clinical predictors. From the combined test set, we developed an objective and unchanging classifier based upon five intrinsic subtype mean expression profiles (i.e. centroids), which is designed for single sample predictions (SSP). The SSP approach was applied to two additional independent data sets and consistently predicted survival in both systemically treated and untreated patient groups. This study validates the "breast tumor intrinsic" subtype classification as an objective means of tumor classification that should be translated into a clinical assay for further retrospective and prospective validation. In addition, our method of combining existing data sets can be used to robustly validate the potential clinical value of any new gene expression profile.
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TL;DR: In this paper, a low-dimensional vector of cognitive and non-cognitive skills explains a variety of labor market and behavioral outcomes, such as teenage pregnancy and marriage, smoking, marijuana use, and participation in illegal activities.
Abstract: This paper establishes that a low dimensional vector of cognitive and noncognitive skills explains a variety of labor market and behavioral outcomes. For many dimensions of social performance cognitive and noncognitive skills are equally important. Our analysis addresses the problems of measurement error, imperfect proxies, and reverse causality that plague conventional studies of cognitive and noncognitive skills that regress earnings (and other outcomes) on proxies for skills. Noncognitive skills strongly influence schooling decisions, and also affect wages given schooling decisions. Schooling, employment, work experience and choice of occupation are affected by latent noncognitive and cognitive skills. We study a variety of correlated risky behaviors such as teenage pregnancy and marriage, smoking, marijuana use, and participation in illegal activities. The same low dimensional vector of abilities that explains schooling choices, wages, employment, work experience and choice of occupation explains these behavioral outcomes.
Johns Hopkins University1, Princeton University2, California Institute of Technology3, Keele University4, University of California, Los Angeles5, Space Science Institute6, University of Arizona7, Pennsylvania State University8, University of Chicago9, University of Southampton10, Fermilab11, University of Washington12
TL;DR: In this article, the spectral energy distributions (SEDs) of 259 quasars with both Sloan Digital Sky Survey (SDS) and Spitzer photometry were analyzed.
Abstract: We present an analysis of the mid-infrared (MIR) and optical properties of type 1 (broad-line) quasars detected by the Spitzer Space Telescope. The MIR color-redshift relation is characterized to z ~ 3, with predictions to z = 7. We demonstrate how combining MIR and optical colors can yield even more efficient selection of active galactic nuclei (AGNs) than MIR or optical colors alone. Composite spectral energy distributions (SEDs) are constructed for 259 quasars with both Sloan Digital Sky Survey and Spitzer photometry, supplemented by near-IR, GALEX, VLA, and ROSAT data, where available. We discuss how the spectral diversity of quasars influences the determination of bolometric luminosities and accretion rates; assuming the mean SED can lead to errors as large as 50% for individual quasars when inferring a bolometric luminosity from an optical luminosity. Finally, we show that careful consideration of the shape of the mean quasar SED and its redshift dependence leads to a lower estimate of the fraction of reddened/obscured AGNs missed by optical surveys as compared to estimates derived from a single mean MIR to optical flux ratio.
TL;DR: This study characterized the in vivo enhancer activity of a large group of non-coding elements in the human genome that are conserved in human–pufferfish, Takifugu (Fugu) rubripes, or ultraconserved in human-mouse–rat.
Abstract: Identifying the sequences that direct the spatial and temporal expression of genes and defining their function in vivo remains a significant challenge in the annotation of vertebrate genomes. One major obstacle is the lack of experimentally validated training sets. In this study, we made use of extreme evolutionary sequence conservation as a filter to identify putative gene regulatory elements, and characterized the in vivo enhancer activity of a large group of non-coding elements in the human genome that are conserved in human-pufferfish, Takifugu (Fugu) rubripes, or ultraconserved in human-mouse-rat. We tested 167 of these extremely conserved sequences in a transgenic mouse enhancer assay. Here we report that 45% of these sequences functioned reproducibly as tissue-specific enhancers of gene expression at embryonic day 11.5. While directing expression in a broad range of anatomical structures in the embryo, the majority of the 75 enhancers directed expression to various regions of the developing nervous system. We identified sequence signatures enriched in a subset of these elements that targeted forebrain expression, and used these features to rank all approximately 3,100 non-coding elements in the human genome that are conserved between human and Fugu. The testing of the top predictions in transgenic mice resulted in a threefold enrichment for sequences with forebrain enhancer activity. These data dramatically expand the catalogue of human gene enhancers that have been characterized in vivo, and illustrate the utility of such training sets for a variety of biological applications, including decoding the regulatory vocabulary of the human genome.
TL;DR: The fourth data release of the Sloan Digital Sky Survey (SDSS) as discussed by the authors includes all survey-quality data taken through 2004 June, including five-band photometric data for 180 million objects selected over 6670 deg2 and 673,280 spectra of galaxies, quasars and stars selected from 4783 deg2 of those imaging data using the standard SDSS target selection algorithms.
Abstract: This paper describes the Fourth Data Release of the Sloan Digital Sky Survey (SDSS), including all survey-quality data taken through 2004 June. The data release includes five-band photometric data for 180 million objects selected over 6670 deg2 and 673,280 spectra of galaxies, quasars, and stars selected from 4783 deg2 of those imaging data using the standard SDSS target selection algorithms. These numbers represent a roughly 27% increment over those of the Third Data Release; all the data from previous data releases are included in the present release. The Fourth Data Release also includes an additional 131,840 spectra of objects selected using a variety of alternative algorithms, to address scientific issues ranging from the kinematics of stars in the Milky Way thick disk to populations of faint galaxies and quasars.
TL;DR: A. P. Calderon as discussed by the authors published by the Brazilian Mathematical Society (SBM) in ATAS of SBM (Rio de Janeiro), pp. 65-73, 1980.
Abstract: This paper is a reprint of the original work by A. P. Calderon published by the Brazilian Mathematical Society (SBM) in ATAS of SBM (Rio de Janeiro), pp. 65-73, 1980. The original paper had no abstract, so this reprint to be truthful to the original work is published with no abstract.
TL;DR: In this paper, the authors proposed a bank-based explanation for the decade-long Japanese slowdown following the asset price collapse in the early 1990s, and showed that zombie-dominated industries exhibit more depressed job creation and destruction, and lower productivity.
Abstract: In this paper, we propose a bank-based explanation for the decade-long Japanese slowdown following the asset price collapse in the early 1990s. We start with the well-known observation that most large Japanese banks were only able to comply with capital standards because regulators were lax in their inspections. To facilitate this forbearance the banks often engaged in sham loan restructurings that kept credit flowing to otherwise insolvent borrowers (that we call zombies). Thus, the normal competitive outcome whereby the zombies would shed workers and lose market share was thwarted. Our model highlights the restructuring implications of the zombie problem. The counterpart of the congestion created by the zombies is a reduction of the profits for healthy firms, which discourages their entry and investment. In this context, even solvent banks do not find good lending opportunities. We confirm our story's key predictions that zombie-dominated industries exhibit more depressed job creation and destruction, and lower productivity. We present firm-level regressions showing that the increase in zombies depressed the investment and employment growth of non-zombies and widened the productivity gap between zombies and non-zombies.
TL;DR: The authors designed a commitment savings product for a Philippine bank and implemented it using a randomized control methodology, which was intended for individuals who want to commit now to restrict access to their savings, and who were sophisticated enough to engage in such a mechanism.
Abstract: We designed a commitment savings product for a Philippine bank and implemented it using a randomized control methodology. The savings product was intended for individuals who want to commit now to restrict access to their savings, and who were sophisticated enough to engage in such a mechanism. We conducted a baseline survey on 1777 existing or former clients of a bank. One month later, we offered the commitment product to a randomly chosen subset of 710 clients; 202 (28.4 percent) accepted the offer and opened the account. In the baseline survey, we asked hypothetical time discounting questions. Women who exhibited a lower discount rate for future relative to current trade-offs, and hence potentially have a preference for commitment, were indeed significantly more likely to open the commitment savings account. After twelve months, average savings balances increased by 81 percentage points for those clients assigned to the treatment group relative to those assigned to the control group. We conclude that the savings response represents a lasting change in savings, and not merely a short-term response to a new product.
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TL;DR: In this paper, the authors identify 16 topics relevant to marketing science, which they classify under five research fields: consumer response to innovation, including attempts to measure consumer innovative-ness, models of new product growth, and recent ideas on network externalities.
Abstract: Innovation is one of the most important issues in business research today. It has been studied in many independent research traditions. Our understanding and study of innovation can benefit from an integrative review of these research traditions. In so doing, we identify 16 topics relevant to marketing science, which we classify under five research fields: - Consumer response to innovation, including attempts to measure consumer innovative-ness, models of new product growth, and recent ideas on network externalities - Organizations and innovation, which are increasingly important as product development becomes more complex and tools more effective but demanding - Market entry strategies, which includes recent research on technology revolution, exten-sive marketing science research on strategies for entry, and issues of portfolio manage-ment - Prescriptive techniques for product development processes, which have been transformed through global pressures, increasingly accurate customer input, web-based communica-tion for dispersed and global product design, and new tools for dealing with complexity over time and across product lines - Defending against market entry and capturing the rewards of innovating, which includes extensive marketing science research on strategies of defense, managing through metrics and rewards to entrants For each topic, we summarize key concepts and highlight research challenges. For pre-scriptive research topics, we also review current thinking and applications. For descriptive top-ics, we review key findings.