Showing papers by "New York University published in 2002"
TL;DR: In this article, the authors show that expected market illiquidity positively affects ex ante stock excess return, suggesting that expected stock ex ante excess return partly represents an illiquid price premium, which complements the cross-sectional positive return-illiquidity relationship.
5,636 citations
TL;DR: This article developed a Ricardian trade model that incorporates realistic geographic features into general equilibrium and delivered simple structural equations for bilateral trade with parameters relating to absolute advantage, comparative advantage, and geographic barriers.
Abstract: We develop a Ricardian trade model that incorporates realistic geographic features into general equilibrium It delivers simple structural equations for bilateral trade with parameters relating to absolute advantage, to comparative advantage (promoting trade), and to geographic barriers (resisting it) We estimate the parameters with data on bilateral trade in manufactures, prices, and geography from 19 OECD countries in 1990 We use the model to explore various issues such as the gains from trade, the role of trade in spreading the benefits of new technology, and the effects of tariff reduction
3,782 citations
TL;DR: In this paper, the authors examined whether audit committee and board characteristics are related to earnings management by the firm and found a negative relation between audit committee independence and abnormal accruals.
3,298 citations
07 Mar 2002
TL;DR: In this paper, the authors describe a peer-to-peer distributed hash table with provable consistency and performance in a fault-prone environment, which routes queries and locates nodes using a novel XOR-based metric topology.
Abstract: We describe a peer-to-peer distributed hash table with provable consistency and performance in a fault-prone environment. Our system routes queries and locates nodes using a novel XOR-based metric topology that simplifies the algorithm and facilitates our proof. The topology has the property that every message exchanged conveys or reinforces useful contact information. The system exploits this information to send parallel, asynchronous query messages that tolerate node failures without imposing timeout delays on users.
3,196 citations
TL;DR: In this article, a critical geographical perspective on neoliberalism is presented, emphasizing the path-dependent character of neoliberal reform projects and the strategic role of cities in the contemporary remaking of political-economic space.
Abstract: This essay elaborates a critical geographical perspective on neoliberalism that emphasizes (a) the path–dependent character of neoliberal reform projects and (b) the strategic role of cities in the contemporary remaking of political–economic space. We begin by presenting the methodological foundations for an approach to the geographies of what we term “actually existing neoliberalism.” In contrast to neoliberal ideology, in which market forces are assumed to operate according to immutable laws no matter where they are “unleashed,” we emphasize the contextual embeddedness of neoliberal restructuring projects insofar as they have been produced within national, regional, and local contexts defined by the legacies of inherited institutional frameworks, policy regimes, regulatory practices, and political struggles. An adequate understanding of actually existing neoliberalism must therefore explore the path–dependent, contextually specific interactions between inherited regulatory landscapes and emergent neoliberal, market–oriented restructuring projects at a broad range of geographical scales. These considerations lead to a conceptualization of contemporary neoliberalization processes as catalysts and expressions of an ongoing creative destruction of political–economic space at multiple geographical scales. While the neoliberal restructuring projects of the last two decades have not established a coherent basis for sustainable capitalist growth, it can be argued that they have nonetheless profoundly reworked the institutional infrastructures upon which Fordist–Keynesian capitalism was grounded. The concept of creative destruction is presented as a useful means for describing the geographically uneven, socially regressive, and politically volatile trajectories of institutional/spatial change that have been crystallizing under these conditions. The essay concludes by discussing the role of urban spaces within the contradictory and chronically unstable geographies of actually existing neoliberalism. Throughout the advanced capitalist world, we suggest, cities have become strategically crucial geographical arenas in which a variety of neoliberal initiatives—along with closely intertwined strategies of crisis displacement and crisis management—have been articulated.
2,818 citations
TL;DR: The signal transducer and activator of transcription (STAT) proteins are among the most well studied of the latent cytoplasmic signal-dependent transcription-factor pathways.
Abstract: Extracellular proteins bound to cell-surface receptors can change nuclear gene expression patterns in minutes, with far-reaching consequences for development, cell growth and homeostasis. The signal transducer and activator of transcription (STAT) proteins are among the most well studied of the latent cytoplasmic signal-dependent transcription-factor pathways. In addition to several roles in normal cell decisions, dysregulation of STAT function contributes to human disease, making the study of these proteins an important topic of current research.
2,720 citations
TL;DR: It is demonstrated that mutations in either ire-1 or the transcription-factor-encoding xbp-1 gene abolished the UPR in Caenorhabditis elegans, suggesting that physiological ER load regulates a developmental decision in higher eukaryotes.
Abstract: The unfolded protein response (UPR), caused by stress, matches the folding capacity of endoplasmic reticulum (ER) to the load of client proteins in the organelle. In yeast, processing of HAC1 mRNA by activated Ire1 leads to synthesis of the transcription factor Hac1 and activation of the UPR. The responses to activated IRE1 in metazoans are less well understood. Here we demonstrate that mutations in either ire-1 or the transcription-factor-encoding xbp-1 gene abolished the UPR in Caenorhabditis elegans. Mammalian XBP-1 is essential for immunoglobulin secretion and development of plasma cells, and high levels of XBP-1 messenger RNA are found in specialized secretory cells. Activation of the UPR causes IRE1-dependent splicing of a small intron from the XBP-1 mRNA both in C. elegans and mice. The protein encoded by the processed murine XBP-1 mRNA accumulated during the UPR, whereas the protein encoded by unprocessed mRNA did not. Purified mouse IRE1 accurately cleaved XBP-1 mRNA in vitro, indicating that XBP-1 mRNA is a direct target of IRE1 endonucleolytic activity. Our findings suggest that physiological ER load regulates a developmental decision in higher eukaryotes.
2,643 citations
TL;DR: In this paper, the authors show that current capital structure is strongly related to historical market values, and that firms are more likely to issue equity when their market values are high, relative to book and past market values.
Abstract: It is well known that firms are more likely to issue equity when their market values are high, relative to book and past market values, and to repurchase equity when their market values are low. We document that the resulting effects on capital structure are very persistent. As a consequence, current capital structure is strongly related to historical market values. The results suggest the theory that capital structure is the cumulative outcome of past attempts to time the equity market. IN CORPORATE F INANCE, “equity market timing” refers to the practice of issuing shares at high prices and repurchasing at low prices. The intention is to exploit temporary f luctuations in the cost of equity relative to the cost of other forms of capital. In the efficient and integrated capital markets studied by Modigliani and Miller ~1958!, the costs of different forms of capital do not vary independently, so there is no gain from opportunistically switching between equity and debt. In capital markets that are inefficient or segmented, by contrast, market timing benefits ongoing shareholders at the expense of entering and exiting ones. Managers thus have incentives to time the market if they think it is possible and if they care more about ongoing shareholders. In practice, equity market timing appears to be an important aspect of real corporate financial policy. There is evidence for market timing in four different kinds of studies. First, analyses of actual financing decisions show that firms tend to issue equity instead of debt when market value is high, relative to book value and past market values, and tend to repurchase equity when market value is low. 1 Second, analyses of long-run stock returns fol
2,516 citations
Chris Stoughton1, Robert H. Lupton2, Mariangela Bernardi3, Michael R. Blanton4 +209 more•Institutions (42)
TL;DR: The Sloan Digital Sky Survey (SDSS) is an imaging and spectroscopic survey that will eventually cover approximately one-quarter of the celestial sphere and collect spectra of ≈106 galaxies, 100,000 quasars, 30,000 stars, and 30, 000 serendipity targets as discussed by the authors.
Abstract: The Sloan Digital Sky Survey (SDSS) is an imaging and spectroscopic survey that will eventually cover approximately one-quarter of the celestial sphere and collect spectra of ≈106 galaxies, 100,000 quasars, 30,000 stars, and 30,000 serendipity targets. In 2001 June, the SDSS released to the general astronomical community its early data release, roughly 462 deg2 of imaging data including almost 14 million detected objects and 54,008 follow-up spectra. The imaging data were collected in drift-scan mode in five bandpasses (u, g, r, i, and z); our 95% completeness limits for stars are 22.0, 22.2, 22.2, 21.3, and 20.5, respectively. The photometric calibration is reproducible to 5%, 3%, 3%, 3%, and 5%, respectively. The spectra are flux- and wavelength-calibrated, with 4096 pixels from 3800 to 9200 A at R ≈ 1800. We present the means by which these data are distributed to the astronomical community, descriptions of the hardware used to obtain the data, the software used for processing the data, the measured quantities for each observed object, and an overview of the properties of this data set.
2,422 citations
TL;DR: It is demonstrated that medulloblastomas are molecularly distinct from other brain tumours including primitive neuroectodermal tumours, atypical teratoid/rhabdoid tumours (AT/RTs) and malignant gliomas, and it is shown that the clinical outcome of children with medullOBlastomas is highly predictable on the basis of the gene expression profiles of their tumours at diagnosis.
Abstract: Embryonal tumours of the central nervous system (CNS) represent a heterogeneous group of tumours about which little is known biologically, and whose diagnosis, on the basis of morphologic appearance alone, is controversial. Medulloblastomas, for example, are the most common malignant brain tumour of childhood, but their pathogenesis is unknown, their relationship to other embryonal CNS tumours is debated, and patients' response to therapy is difficult to predict. We approached these problems by developing a classification system based on DNA microarray gene expression data derived from 99 patient samples. Here we demonstrate that medulloblastomas are molecularly distinct from other brain tumours including primitive neuroectodermal tumours (PNETs), atypical teratoid/rhabdoid tumours (AT/RTs) and malignant gliomas. Previously unrecognized evidence supporting the derivation of medulloblastomas from cerebellar granule cells through activation of the Sonic Hedgehog (SHH) pathway was also revealed. We show further that the clinical outcome of children with medulloblastomas is highly predictable on the basis of the gene expression profiles of their tumours at diagnosis.
2,365 citations
TL;DR: CaP biomaterials have outstanding properties: similarity in composition to bone mineral; bioactivity; ability to form bone apatitelike material or carbonate hydroxyapatite on their surfaces; and osteoconductivity (ability to provide the appropriate scaffold or template for bone formation).
Abstract: Bone is formed by a series of complex events involving the mineralization of extracellular matrix proteins rigidly orchestrated by cells with specific functions of maintaining the integrity of the bone. Bone, similar to other calcified tissues, is an intimate composite of the organic (collagen and noncollagenous proteins) and inorganic or mineral phases. The bone mineral idealized as calcium hydroxyapatite, Ca10 (PO4)(6)(OH)2, is a carbonatehydroxyapatite, approximated by the formula: (Ca,X)(10)(PO4,HPO4,CO3)(6)(OH,Y)2, where X are cations (magnesium, sodium, strontium ions) that can substitute for the calcium ions, and Y are anions (chloride or fluoride ions) that can substitute for the hydroxyl group. The current author presents a brief review of CaP biomaterials that now are used as grafts for bone repair, augmentation, or substitution. Commercially-available CaP biomaterials differ in origin (natural or synthetic), composition (hydroxyapatite, beta-tricalcium phosphate, and biphasic CaP), or physical forms (particulates, blocks, cements, coatings on metal implants, composites with polymers), and in physicochemical properties. CaP biomaterials have outstanding properties: similarity in composition to bone mineral; bioactivity (ability to form bone apatitelike material or carbonate hydroxyapatite on their surfaces), ability to promote cellular function and expression leading to formation of a uniquely strong bone-CaP biomaterial interface; and osteoconductivity (ability to provide the appropriate scaffold or template for bone formation). In addition, CaP biomaterials with appropriate three-dimensional geometry are able to bind and concentrate endogenous bone morphogenetic proteins in circulation, and may become osteoinductive (capable of osteogenesis), and can be effective carriers of bone cell seeds. Therefore, CaP biomaterials potentially are useful in tissue engineering for regeneration of hard tissues.
TL;DR: In this article, the authors review the formalism and applications of non-linear perturbation theory (PT) to understand the large-scale structure of the universe, from the linear to the nonlinear regime.
TL;DR: A novel diphtheria toxin-based system that allows the inducible, short-term ablation of dendritic cells (DC) in vivo is reported and it is shown that in vivo DC are required to cross-prime CTL precursors.
TL;DR: It is proposed that three such endophenotypes — a specific abnormality in reward-related circuitry that leads to shortened delay gradients, deficits in temporal processing that result in high intrasubject intertrial variability, and deficits in working memory — are most amenable to integrative collaborative approaches that aim to uncover the causes of ADHD.
Abstract: Research on attention-deficit/hyperactivity disorder (ADHD), a highly prevalent and controversial condition, has, for the most part, been descriptive and atheoretical. The imperative to discover the genetic and environmental risk factors for ADHD is motivating the search for quantifiable intermediate constructs, termed endophenotypes. In this selective review, we conclude that such endophenotypes should be solidly grounded in the neurosciences. We propose that three such endophenotypes — a specific abnormality in reward-related circuitry that leads to shortened delay gradients, deficits in temporal processing that result in high intrasubject intertrial variability, and deficits in working memory — are most amenable to integrative collaborative approaches that aim to uncover the causes of ADHD.
TL;DR: Understanding the host–microbial interactions that lead to neoplasia will improve cancer-targeted therapeutics and diagnostics, and provide mechanistic insights into other malignancies that arise within the context of microbially initiated inflammatory states.
Abstract: Although gastric adenocarcinoma is associated with the presence of Helicobacter pylori in the stomach, only a small fraction of colonized individuals develop this common malignancy. H. pylori strain and host genotypes probably influence the risk of carcinogenesis by differentially affecting host inflammatory responses and epithelial-cell physiology. Understanding the host-microbial interactions that lead to neoplasia will improve cancer-targeted therapeutics and diagnostics, and provide mechanistic insights into other malignancies that arise within the context of microbially initiated inflammatory states.
TL;DR: Developmental trajectories for all structures, except caudate, remain roughly parallel for patients and controls during childhood and adolescence, suggesting that genetic and/or early environmental influences on brain development in ADHD are fixed, nonprogressive, and unrelated to stimulant treatment.
Abstract: ContextVarious anatomic brain abnormalities have been reported for attention-deficit/hyperactivity
disorder (ADHD), with varying methods, small samples, cross-sectional designs,
and without accounting for stimulant drug exposure.ObjectiveTo compare regional brain volumes at initial scan and their change over
time in medicated and previously unmedicated male and female patients with
ADHD and healthy controls.Design, Setting, and ParticipantsCase-control study conducted from 1991-2001 at the National Institute
of Mental Health, Bethesda, Md, of 152 children and adolescents with ADHD
(age range, 5-18 years) and 139 age- and sex-matched controls (age range,
4.5-19 years) recruited from the local community, who contributed 544 anatomic
magnetic resonance images.Main Outcome MeasuresUsing completely automated methods, initial volumes and prospective
age-related changes of total cerebrum, cerebellum, gray and white matter for
the 4 major lobes, and caudate nucleus of the brain were compared in patients
and controls.ResultsOn initial scan, patients with ADHD had significantly smaller brain
volumes in all regions, even after adjustment for significant covariates.
This global difference was reflected in smaller total cerebral volumes (−3.2%,
adjusted F1,280 = 8.30, P = .004) and
in significantly smaller cerebellar volumes (−3.5%, adjusted F1,280 = 12.29, P = .001). Compared with controls,
previously unmedicated children with ADHD demonstrated significantly smaller
total cerebral volumes (overall F2,288 = 6.65; all pairwise comparisons
Bonferroni corrected, −5.8%; P = .002) and
cerebellar volumes (−6.2%, F2,288 = 8.97, P<.001). Unmedicated children with ADHD also exhibited strikingly
smaller total white matter volumes (F2,288 = 11.65) compared with
controls (−10.7%, P<.001) and with medicated
children with ADHD (−8.9%, P<.001). Volumetric
abnormalities persisted with age in total and regional cerebral measures (P = .002) and in the cerebellum (P =
.003). Caudate nucleus volumes were initially abnormal for patients with ADHD
(P = .05), but diagnostic differences disappeared
as caudate volumes decreased for patients and controls during adolescence.
Results were comparable for male and female patients on all measures. Frontal
and temporal gray matter, caudate, and cerebellar volumes correlated significantly
with parent- and clinician-rated severity measures within the ADHD sample
(Pearson coefficients between −0.16 and −0.26; all P values were <.05).ConclusionsDevelopmental trajectories for all structures, except caudate, remain
roughly parallel for patients and controls during childhood and adolescence,
suggesting that genetic and/or early environmental influences on brain development
in ADHD are fixed, nonprogressive, and unrelated to stimulant treatment.
TL;DR: In this article, the concept of fractional kinetics is reviewed for systems with Hamiltonian chaos, where the notions of dynamical quasi-traps, Poincare recurrences, Levy flights, exit time distributions, phase space topology, etc.
TL;DR: It is suggested that type II diabetes may alter EPC biology in processes critical for new blood vessel growth and may identify a population at high risk for morbidity and mortality after vascular occlusive events.
Abstract: Background— The recent discovery of circulating endothelial progenitor cells (EPCs) has altered our understanding of new blood vessel growth such as occurs during collateral formation. Because diabetic complications occur in conditions in which EPC contributions have been demonstrated, EPC dysfunction may be important in their pathophysiology. Methods and Results— EPCs were isolated from human type II diabetics (n=20) and age-matched control subjects (n=20). Proliferation of diabetic EPCs relative to control subjects was decreased by 48% (P<0.01) and inversely correlated with patient levels of hemoglobin A1C (P<0.05). Diabetic EPCs had normal adhesion to fibronectin, collagen, and quiescent endothelial cells but a decreased adherence to human umbilical vein endothelial cells activated by tumor necrosis factor-α (TNF-α) (P<0.05). In a Matrigel assay, diabetic EPCs were 2.5 times less likely to participate in tubule formation compared with controls (P<0.05). Conclusions— These findings suggest that type II ...
TL;DR: This work introduces pricing of transmit powers in order to obtain Pareto improvement of the noncooperative power control game, i.e., to obtain improvements in user utilities relative to the case with no pricing.
Abstract: A major challenge in the operation of wireless communications systems is the efficient use of radio resources. One important component of radio resource management is power control, which has been studied extensively in the context of voice communications. With the increasing demand for wireless data services, it is necessary to establish power control algorithms for information sources other than voice. We present a power control solution for wireless data in the analytical setting of a game theoretic framework. In this context, the quality of service (QoS) a wireless terminal receives is referred to as the utility and distributed power control is a noncooperative power control game where users maximize their utility. The outcome of the game results in a Nash (1951) equilibrium that is inefficient. We introduce pricing of transmit powers in order to obtain Pareto improvement of the noncooperative power control game, i.e., to obtain improvements in user utilities relative to the case with no pricing. Specifically, we consider a pricing function that is a linear function of the transmit power. The simplicity of the pricing function allows a distributed implementation where the price can be broadcast by the base station to all the terminals. We see that pricing is especially helpful in a heavily loaded system.
TL;DR: It is concluded that a broad range of intensive research and development is urgently needed to produce technological options that can allow both climate stabilization and economic development.
Abstract: Stabilizing the carbon dioxide-induced component of climate change is an energy problem. Establishment of a course toward such stabilization will require the development within the coming decades of primary energy sources that do not emit carbon dioxide to the atmosphere, in addition to efforts to reduce end-use energy demand. Mid-century primary power requirements that are free of carbon dioxide emissions could be several times what we now derive from fossil fuels (approximately 10(13) watts), even with improvements in energy efficiency. Here we survey possible future energy sources, evaluated for their capability to supply massive amounts of carbon emission-free energy and for their potential for large-scale commercialization. Possible candidates for primary energy sources include terrestrial solar and wind energy, solar power satellites, biomass, nuclear fission, nuclear fusion, fission-fusion hybrids, and fossil fuels from which carbon has been sequestered. Non-primary power technologies that could contribute to climate stabilization include efficiency improvements, hydrogen production, storage and transport, superconducting global electric grids, and geoengineering. All of these approaches currently have severe deficiencies that limit their ability to stabilize global climate. We conclude that a broad range of intensive research and development is urgently needed to produce technological options that can allow both climate stabilization and economic development.
TL;DR: This article found that people who can better disclose their true self to others on the Internet than in face-to-face settings will be more likely to form close relationships on-line and will tend to bring those virtual relationships into their real lives.
Abstract: We hypothesized that people who can better disclose their “true” or inner self to others on the Internet than in face-to-face settings will be more likely to form close relationships on-line and will tend to bring those virtual relationships into their “real” lives. Study 1, a survey of randomly selected Internet newsgroup posters, showed that those who better express their true self over the Internet were more likely than others to have formed close on-line relationships and moved these friendships to a face-to-face basis. Study 2 revealed that the majority of these close Internet relationships were still intact 2 years later. Finally, a laboratory experiment found that undergraduates liked each other more following an Internet compared to a face-to-face initial meeting.
TL;DR: The structure of the Cul1–Rbx1–Skp1–F boxSkp2 SCF complex suggests that Cul1 may contribute to catalysis through the positioning of the substrate and the ubiquitin-conjugating enzyme, and this model is supported by Cul1 mutations designed to eliminate the rigidity of the scaffold.
Abstract: SCF complexes are the largest family of E3 ubiquitin–protein ligases and mediate the ubiquitination of diverse regulatory and signalling proteins. Here we present the crystal structure of the Cul1–Rbx1–Skp1–F boxSkp2 SCF complex, which shows that Cul1 is an elongated protein that consists of a long stalk and a globular domain. The globular domain binds the RING finger protein Rbx1 through an intermolecular β-sheet, forming a two-subunit catalytic core that recruits the ubiquitin-conjugating enzyme. The long stalk, which consists of three repeats of a novel five-helix motif, binds the Skp1–F boxSkp2 protein substrate-recognition complex at its tip. Cul1 serves as a rigid scaffold that organizes the Skp1–F boxSkp2 and Rbx1 subunits, holding them over 100 A apart. The structure suggests that Cul1 may contribute to catalysis through the positioning of the substrate and the ubiquitin-conjugating enzyme, and this model is supported by Cul1 mutations designed to eliminate the rigidity of the scaffold.
TL;DR: A significant proportion of occult SDB in the general population would be missed if screening or case finding were based solely on increased body habitus or male sex, particularly in older adults.
Abstract: Background Sleep-disordered breathing (SDB) is common, but largely undiagnosed in the general population. Information on demographic patterns of SDB occurrence and its predictive factors in the general population is needed to target high-risk groups that may benefit from diagnosis. Methods The sample comprised 5615 community-dwelling men and women aged between 40 and 98 years who were enrolled in the Sleep Heart Health Study. Data were collected by questionnaire, clinical examinations, and in-home polysomnography. Sleep-disordered breathing status was based on the average number of apnea and hypopnea episodes per hour of sleep (apnea-hypopnea index [AHI]). We used multiple logistic regression modeling to estimate cross-sectional associations of selected participant characteristics with SDB defined by an AHI of 15 or greater. Results Male sex, age, body mass index, neck girth, snoring, and repeated breathing pause frequency were independent, significant correlates of an AHI of 15 or greater. People reporting habitual snoring, loud snoring, and frequent breathing pauses were 3 to 4 times more likely to have an AHI of 15 or greater vs an AHI less than 15, but there were weaker associations for other factors with an AHI of 15 or greater. The odds ratios (95% confidence interval) for an AHI of 15 or greater vs an AHI less than 15 were 1.6 and 1.5, respectively, for 1-SD increments in body mass index and neck girth. As age increased, the magnitude of associations for SDB and body habitus, snoring, and breathing pauses decreased. Conclusions A significant proportion of occult SDB in the general population would be missed if screening or case finding were based solely on increased body habitus or male sex. Breathing pauses and obesity may be particularly insensitive for identifying SDB in older people. A better understanding of predictive factors for SDB, particularly in older adults, is needed.
TL;DR: In this article, a new class of multivariate models called dynamic conditional correlation (DCC) models is proposed, which have the flexibility of univariate GARCH models coupled with parsimonious parametric models for the correlations.
Abstract: Time varying correlations are often estimated with Multivariate Garch models that are linear in squares and cross products of the data. A new class of multivariate models called dynamic conditional correlation (DCC) models is proposed. These have the flexibility of univariate GARCH models coupled with parsimonious parametric models for the correlations. They are not linear but can often be estimated very simply with univariate or two step methods based on the likelihood function. It is shown that they perform well in a variety of situations and provide sensible empirical results.
TL;DR: This article found that people who feel better able to express their true self in Internet rather than face-to-face interaction settings are more likely to form close relationships with people met on the Internet.
Abstract: Those who feel better able to express their “true selves” in Internet rather than face-to-face interaction settings are more likely to form close relationships with people met on the Internet (McKenna, Green, & Gleason, this issue). Building on these correlational findings from survey data, we conducted three laboratory experiments to directly test the hypothesized causal role of differential self-expression in Internet relationship formation. Experiments 1 and 2, using a reaction time task, found that for university undergraduates, the true-self concept is more accessible in memory during Internet interactions, and the actual self more accessible during face-to-face interactions. Experiment 3 confirmed that people randomly assigned to interact over the Internet (vs. face to face) were better able to express their true-self qualities to their partners.
TL;DR: Because energy content increases with portion size, educational and other public health efforts to address obesity should focus on the need for people to consume smaller portions.
Abstract: Objectives Because larger food portions could be contributing to the increasing prevalence of overweight and obesity, this study was designed to weigh samples of marketplace foods, identify historical changes in the sizes of those foods, and compare current portions with federal standardsMethods We obtained information about current portions from manufacturers or from direct weighing; we obtained information about past portions from manufacturers or contemporary publicationsResults Marketplace food portions have increased in size and now exceed federal standards Portion sizes began to grow in the 1970s, rose sharply in the 1980s, and have continued in parallel with increasing body weightsConclusions Because energy content increases with portion size, educational and other public health efforts to address obesity should focus on the need for people to consume smaller portions
TL;DR: The authors found that firms that meet or beat current analysts' earnings expectations (MBE) enjoy a higher return over the quarter than firms with similar quarterly earnings forecast errors that fail to meet these expectations.
TL;DR: It is shown that filopodia-like dendritic protrusions, extending and retracting over hours, are abundant in young animals but virtually absent from the adult, providing a potential structural basis for long-term information storage.
Abstract: The structural dynamics of synapses probably has a crucial role in the development and plasticity of the nervous system. In the mammalian brain, the vast majority of excitatory axo-dendritic synapses occur on dendritic specializations called 'spines'. However, little is known about their long-term changes in the intact developing or adult animal. To address this question we developed a transcranial two-photon imaging technique to follow identified spines of layer-5 pyramidal neurons in the primary visual cortex of living transgenic mice expressing yellow fluorescent protein. Here we show that filopodia-like dendritic protrusions, extending and retracting over hours, are abundant in young animals but virtually absent from the adult. In young mice, within the 'critical period' for visual cortex development, approximately 73% of spines remain stable over a one-month interval; most changes are associated with spine elimination. In contrast, in adult mice, the overwhelming majority of spines (approximately 96%) remain stable over the same interval with a half-life greater than 13 months. These results indicate that spines, initially plastic during development, become remarkably stable in the adult, providing a potential structural basis for long-term information storage.
TL;DR: The failure of past "entrepreneurial personality" based research to clearly distinguish the unique contributions to the entrepreneurial process of entrepreneurs as people, has created a vacuum with....
Abstract: The failure of past “entrepreneurial personality”—based research to clearly distinguish the unique contributions to the entrepreneurial process of entrepreneurs as people, has created a vacuum with...
Book•
25 Apr 2002
TL;DR: Findings from 5 large, randomized studies of the symptomatic treatment of probable and possible vascular dementia indicate that the presence of a cholinergic deficit is not required for the anticholinesterases to produce cognitive improvement, and so the cholin allergic hypothesis is neither necessary nor sufficient to explain the effects of these drugs.
Abstract: Cerebrovascular disease is the second most common cause of acquired cognitive impairment and dementia and contributes to cognitive decline in the neurodegenerative dementias. The current narrow definitions of vascular dementia should be broadened to recognise the important part cerebrovascular disease plays in several cognitive disorders, including the hereditary vascular dementias, multi-infarct dementia, post-stroke dementia, subcortical ischaemic vascular disease and dementia, mild cognitive impairment, and degenerative dementias (including Alzheimer's disease, frontotemporal dementia, and dementia with Lewy bodies). Here we review the current state of scientific knowledge on the subject of vascular brain burden. Important non-cognitive features include depression, apathy, and psychosis. We propose use of the term vascular cognitive impairment, which is characterised by a specific cognitive profile involving preserved memory with impairments in attentional and executive functioning. Diagnostic criteria have been proposed for some subtypes of vascular cognitive impairment, and there is a pressing need to validate and further refine these. Clinical trials in vascular cognitive impairment are in their infancy but support the value of therapeutic interventions for symptomatic treatment.