Showing papers by "Northwestern University published in 2003"
TL;DR: In this paper, the authors describe recent progress in the theory of nanoparticle optical properties, particularly methods for solving Maxwell's equations for light scattering from particles of arbitrary shape in a complex environment.
Abstract: The optical properties of metal nanoparticles have long been of interest in physical chemistry, starting with Faraday's investigations of colloidal gold in the middle 1800s. More recently, new lithographic techniques as well as improvements to classical wet chemistry methods have made it possible to synthesize noble metal nanoparticles with a wide range of sizes, shapes, and dielectric environments. In this feature article, we describe recent progress in the theory of nanoparticle optical properties, particularly methods for solving Maxwell's equations for light scattering from particles of arbitrary shape in a complex environment. Included is a description of the qualitative features of dipole and quadrupole plasmon resonances for spherical particles; a discussion of analytical and numerical methods for calculating extinction and scattering cross-sections, local fields, and other optical properties for nonspherical particles; and a survey of applications to problems of recent interest involving triangula...
9,086 citations
TL;DR: The mechanisms underlying the major steps of migration and the signaling pathways that regulate them are described, and recent advances investigating the nature of polarity in migrating cells and the pathways that establish it are outlined.
Abstract: Cell migration is a highly integrated multistep process that orchestrates embryonic morphogenesis; contributes to tissue repair and regeneration; and drives disease progression in cancer, mental retardation, atherosclerosis, and arthritis. The migrating cell is highly polarized with complex regulatory pathways that spatially and temporally integrate its component processes. This review describes the mechanisms underlying the major steps of migration and the signaling pathways that regulate them, and outlines recent advances investigating the nature of polarity in migrating cells and the pathways that establish it.
4,839 citations
TL;DR: A core set of proteins including actin, Arp2/3 complex, profilin, capping protein, and ADF/cofilin can reconstitute the process in vitro, and mathematical models of the constituent reactions predict the rate of motion.
3,793 citations
TL;DR: In this article, the authors provide a general framework for integration of high-frequency intraday data into the measurement, modeling, and forecasting of daily and lower frequency volatility and return distributions.
Abstract: This paper provides a general framework for integration of high-frequency intraday data into the measurement, modeling, and forecasting of daily and lower frequency volatility and return distributions. Most procedures for modeling and forecasting financial asset return volatilities, correlations, and distributions rely on restrictive and complicated parametric multivariate ARCH or stochastic volatility models, which often perform poorly at intraday frequencies. Use of realized volatility constructed from high-frequency intraday returns, in contrast, permits the use of traditional time series procedures for modeling and forecasting. Building on the theory of continuous-time arbitrage-free price processes and the theory of quadratic variation, we formally develop the links between the conditional covariance matrix and the concept of realized volatility. Next, using continuously recorded observations for the Deutschemark / Dollar and Yen / Dollar spot exchange rates covering more than a decade, we find that forecasts from a simple long-memory Gaussian vector autoregression for the logarithmic daily realized volatilities perform admirably compared to popular daily ARCH and related models. Moreover, the vector autoregressive volatility forecast, coupled with a parametric lognormal-normal mixture distribution implied by the theoretically and empirically grounded assumption of normally distributed standardized returns, gives rise to well-calibrated density forecasts of future returns, and correspondingly accurate quantile estimates. Our results hold promise for practical modeling and forecasting of the large covariance matrices relevant in asset pricing, asset allocation and financial risk management applications.
2,823 citations
Harvard University1, Aarhus University2, University of Texas at Austin3, Memorial Hermann Texas Medical Center4, National and Kapodistrian University of Athens5, University of Kentucky6, Utrecht University7, Icahn School of Medicine at Mount Sinai8, Tufts University9, Tulane University10, Armed Forces Institute of Pathology11, University of Washington12, Stanford University13, Erasmus University Rotterdam14, University of Turku15, University of Münster16, Mayo Clinic17, Emory University18, University of Bristol19, University of Ulm20, Veterans Health Administration21, University of Texas Health Science Center at Houston22, University of California, Los Angeles23, University of Pavia24, Pfizer25, University of Texas Southwestern Medical Center26, Lenox Hill Hospital27, Baylor College of Medicine28, University of Maryland, Baltimore29, Karolinska Institutet30, University of Chicago31, Cedars-Sinai Medical Center32, Northwestern University33, Indiana University34
TL;DR: The term "vulnerable patient" may be more appropriate and is proposed now for the identification of subjects with high likelihood of developing cardiac events in the near future and a quantitative method for cumulative risk assessment of vulnerable patients needs to be developed.
Abstract: Atherosclerotic cardiovascular disease results in >19 million deaths annually, and coronary heart disease accounts for the majority of this toll. Despite major advances in treatment of coronary heart disease patients, a large number of victims of the disease who are apparently healthy die suddenly without prior symptoms. Available screening and diagnostic methods are insufficient to identify the victims before the event occurs. The recognition of the role of the vulnerable plaque has opened new avenues of opportunity in the field of cardiovascular medicine. This consensus document concludes the following. (1) Rupture-prone plaques are not the only vulnerable plaques. All types of atherosclerotic plaques with high likelihood of thrombotic complications and rapid progression should be considered as vulnerable plaques. We propose a classification for clinical as well as pathological evaluation of vulnerable plaques. (2) Vulnerable plaques are not the only culprit factors for the development of acute coronary syndromes, myocardial infarction, and sudden cardiac death. Vulnerable blood (prone to thrombosis) and vulnerable myocardium (prone to fatal arrhythmia) play an important role in the outcome. Therefore, the term "vulnerable patient" may be more appropriate and is proposed now for the identification of subjects with high likelihood of developing cardiac events in the near future. (3) A quantitative method for cumulative risk assessment of vulnerable patients needs to be developed that may include variables based on plaque, blood, and myocardial vulnerability. In Part I of this consensus document, we cover the new definition of vulnerable plaque and its relationship with vulnerable patients. Part II of this consensus document focuses on vulnerable blood and vulnerable myocardium and provide an outline of overall risk assessment of vulnerable patients. Parts I and II are meant to provide a general consensus and overviews the new field of vulnerable patient. Recently developed assays (eg, C-reactive protein), imaging techniques (eg, CT and MRI), noninvasive electrophysiological tests (for vulnerable myocardium), and emerging catheters (to localize and characterize vulnerable plaque) in combination with future genomic and proteomic techniques will guide us in the search for vulnerable patients. It will also lead to the development and deployment of new therapies and ultimately to reduce the incidence of acute coronary syndromes and sudden cardiac death. We encourage healthcare policy makers to promote translational research for screening and treatment of vulnerable patients.
2,719 citations
Harvard University1, University of Arkansas at Little Rock2, Cedars-Sinai Medical Center3, Northwestern University4, Catholic Medical Center5, Mayo Clinic6, Cleveland Clinic7, University of South Florida8, University of Texas MD Anderson Cancer Center9, University of North Carolina at Chapel Hill10, Takeda Pharmaceutical Company11
TL;DR: Bortezomib, a member of a new class of anticancer drugs, is active in patients with relapsed multiple myeloma that is refractory to conventional chemotherapy.
Abstract: Background Bortezomib, a boronic acid dipeptide, is a novel proteasome inhibitor that has been shown in preclinical and phase 1 studies to have antimyeloma activity. Methods In this multicenter, open-label, nonrandomized, phase 2 trial, we enrolled 202 patients with relapsed myeloma that was refractory to the therapy they had received most recently. Patients received 1.3 mg of bortezomib per square meter of body-surface area twice weekly for 2 weeks, followed by 1 week without treatment, for up to eight cycles (24 weeks). In patients with a suboptimal response, oral dexamethasone (20 mg daily, on the day of and the day after bortezomib administration) was added to the regimen. The response was evaluated according to the criteria of the European Group for Blood and Marrow Transplantation and confirmed by an independent review committee. Results Of 193 patients who could be evaluated, 92 percent had been treated with three or more of the major classes of agents for myeloma, and in 91 percent, the myeloma wa...
2,586 citations
TL;DR: An ultrasensitive method for detecting protein analytes has been developed and comparable clinically accepted conventional assays for detecting the same target have sensitivity limits of ∼3 picomdar, six orders of magnitude less sensitive than what is observed with this method.
Abstract: An ultrasensitive method for detecting protein analytes has been developed. The system relies on magnetic microparticle probes with antibodies that specifically bind a target of interest [prostate-specific antigen (PSA) in this case] and nanoparticle probes that are encoded with DNA that is unique to the protein target of interest and antibodies that can sandwich the target captured by the microparticle probes. Magnetic separation of the complexed probes and target followed by dehybridization of the oligonucleotides on the nanoparticle probe surface allows the determination of the presence of the target protein by identifying the oligonucleotide sequence released from the nanoparticle probe. Because the nanoparticle probe carries with it a large number of oligonucleotides per protein binding event, there is substantial amplification and PSA can be detected at 30 attomolar concentration. Alternatively, a polymerase chain reaction on the oligonucleotide bar codes can boost the sensitivity to 3 attomolar. Comparable clinically accepted conventional assays for detecting the same target have sensitivity limits of ∼3 picomdar, six orders of magnitude less sensitive than what is observed with this method.
2,430 citations
Cornell University1, Cedars-Sinai Medical Center2, University of Texas MD Anderson Cancer Center3, Harvard University4, University of California, Los Angeles5, University of Pittsburgh6, University of Wisconsin-Madison7, Anschutz Medical Campus8, Vanderbilt University9, Loyola University Chicago10, Northwestern University11, AstraZeneca12
TL;DR: Gefitinib, a well-tolerated oral EGFR-tyrosine kinase inhibitor, improved disease-related symptoms and induced radiographic tumor regressions in patients with NSCLC persisting after chemotherapy.
Abstract: ContextMore persons in the United States die from non–small cell lung
cancer (NSCLC) than from breast, colorectal, and prostate cancer combined.
In preclinical testing, oral gefitinib inhibited the growth of NSCLC tumors
that express the epidermal growth factor receptor (EGFR), a mediator of cell
signaling, and phase 1 trials have demonstrated that a fraction of patients
with NSCLC progressing after chemotherapy experience both a decrease in lung
cancer symptoms and radiographic tumor shrinkages with gefitinib.ObjectiveTo assess differences in symptomatic and radiographic response among
patients with NSCLC receiving 250-mg and 500-mg daily doses of gefitinib.Design, Setting, and PatientsDouble-blind, randomized phase 2 trial conducted from November 2000
to April 2001 in 30 US academic and community oncology centers. Patients (N
= 221) had either stage IIIB or IV NSCLC for which they had received at least
2 chemotherapy regimens.InterventionDaily oral gefitinib, either 500 mg (administered as two 250-mg gefitinib
tablets) or 250 mg (administered as one 250-mg gefitinib tablet and 1 matching
placebo).Main Outcome MeasuresImprovement of NSCLC symptoms (2-point or greater increase in score
on the summed lung cancer subscale of the Functional Assessment of Cancer
Therapy-Lung [FACT-L] instrument) and tumor regression (>50% decrease in lesion
size on imaging studies).ResultsOf 221 patients enrolled, 216 received gefitinib as randomized. Symptoms
of NSCLC improved in 43% (95% confidence interval [CI], 33%-53%) of patients
receiving 250 mg of gefitinib and in 35% (95% CI, 26%-45%) of patients receiving
500 mg. These benefits were observed within 3 weeks in 75% of patients. Partial
radiographic responses occurred in 12% (95% CI, 6%-20%) of individuals receiving
250 mg of gefitinib and in 9% (95% CI, 4%-16%) of those receiving 500 mg.
Symptoms improved in 96% of patients with partial radiographic responses.
The overall survival at 1 year was 25%. There were no significant differences
between the 250-mg and 500-mg doses in rates of symptom improvement (P = .26), radiographic tumor regression (P = .51), and projected 1-year survival (P =
.54). The 500-mg dose was associated more frequently with transient acne-like
rash (P = .04) and diarrhea (P = .006).ConclusionsGefitinib, a well-tolerated oral EGFR-tyrosine kinase inhibitor, improved
disease-related symptoms and induced radiographic tumor regressions in patients
with NSCLC persisting after chemotherapy.
2,420 citations
TL;DR: The findings of this study reveal an important, and much underrecognized, mechanism of stratification in the criminal justice system, which presents a major barrier to employment, with important implications for racial disparities.
Abstract: With over 2 million individuals currently incarcerated, and over half a million prisoners released each year, the large and growing number of men being processed through the criminal justice system raises important questions about the consequences of this massive institutional intervention. This article focuses on the consequences of incarceration for the employment outcomes of black and white job seekers. The present study adopts an experimental audit approach—in which matched pairs of individuals applied for real entry‐level jobs—to formally test the degree to which a criminal record affects subsequent employment opportunities. The findings of this study reveal an important, and much underrecognized, mechanism of stratification. A criminal record presents a major barrier to employment, with important implications for racial disparities.
2,352 citations
TL;DR: Molecular conductance junctions are structures in which single molecules or small groups of molecules conduct electrical current between two electrodes and there is still limited correspondence between experimental and theoretical studies of these systems.
Abstract: Molecular conductance junctions are structures in which single molecules or small groups of molecules conduct electrical current between two electrodes. In such junctions, the connection between the molecule and the electrodes greatly affects the current-voltage characteristics. Despite several experimental and theoretical advances, including the understanding of simple systems, there is still limited correspondence between experimental and theoretical studies of these systems.
2,195 citations
TL;DR: A meta-analysis of 45 studies of transformational, transactional, and laissez-faire leadership styles found that female leaders were more transformational than male leaders and also engaged in more of the contingent reward behaviors that are a component of transactional leadership.
Abstract: A meta-analysis of 45 studies of transformational, transactional, and laissez-faire leadership styles found that female leaders were more transformational than male leaders and also engaged in more of the contingent reward behaviors that are a component of transactional leadership. Male leaders were generally more likely to manifest the other aspects of transactional leadership (active and passive management by exception) and laissez-faire leadership. Although these differences between male and female leaders were small, the implications of these findings are encouraging for female leadership because other research has established that all of the aspects of leadership style on which women exceeded men relate positively to leaders' effectiveness whereas all of the aspects on which men exceeded women have negative or null relations to effectiveness.
TL;DR: In this paper, the role of rutile in mixed-phase titania photocatalyst was investigated by EPR spectroscopy, showing that the transition points between these two phases allow for rapid electron transfer from pure-phase rutiles to anatase.
Abstract: Charge separation characteristics of a high-activity, mixed-phase titania photocatalyst (Degussa P25) are probed by EPR spectroscopy. While previous proposals consider rutile as a passive electron sink hindering recombination in anatase, this research details the critical and active role of rutile in TiO2 formulations. The inactivity of pure-phase rutile is due in part to rapid rates of recombination. Yet, in mixed-phase TiO2, charges produced on rutile by visible light are stabilized through electron transfer to lower energy anatase lattice trapping sites. These results suggest that within mixed-phase titania (P25) there is a morphology of nanoclusters containing atypically small rutile crystallites interwoven with anatase crystallites. The transition points between these two phases allow for rapid electron transfer from rutile to anatase. Thus, rutile acts as an antenna to extend the photoactivity into visible wavelengths and the structural arrangement of the similarly sized TiO2 crystallites creates ca...
University of Texas Southwestern Medical Center1, George Washington University2, Washington University in St. Louis3, New York University4, National Institutes of Health5, Northwestern University6, Emory University7, University of Colorado Denver8, Beaumont Hospital9, San Antonio Military Medical Center10, Yale University11, University of Maryland, Baltimore12, NewYork–Presbyterian Hospital13, University of Iowa14, Mayo Clinic15, Henry Ford Health System16, Vanderbilt University17, University of California, San Diego18, Walter Reed Army Institute of Research19, Baylor College of Medicine20
TL;DR: Long-term combination therapy with doxazosin and finasteride was safe and reduced the risk of overall clinical progression of benign prostatic hyperplasia significantly more than did treatment with either drug alone.
Abstract: background Benign prostatic hyperplasia is commonly treated with alpha-adrenergic–receptor antagonists (alpha-blockers) or 5 a -reductase inhibitors. The long-term effect of these drugs, singly or combined, on the risk of clinical progression is unknown. methods We conducted a long-term, double-blind trial (mean follow-up, 4.5 years) involving 3047 men to compare the effects of placebo, doxazosin, finasteride, and combination therapy on measures of the clinical progression of benign prostatic hyperplasia. results The risk of overall clinical progression — defined as an increase above base line of at least 4 points in the American Urological Association symptom score, acute urinary retention, urinary incontinence, renal insufficiency, or recurrent urinary tract infection — was significantly reduced by doxazosin (39 percent risk reduction, P<0.001) and finasteride (34 percent risk reduction, P=0.002), as compared with placebo. The reduction in risk associated with combination therapy (66 percent for the comparison with placebo, P<0.001) was significantly greater than that associated with doxazosin (P<0.001) or finasteride (P<0.001) alone. The risks of acute urinary retention and the need for invasive therapy were significantly reduced by combination therapy (P<0.001) and finasteride (P<0.001) but not by doxazosin. Doxazosin (P<0.001), finasteride (P =0.001), and combination therapy (P<0.001) each resulted in significant improvement in symptom scores, with combination therapy being superior to both doxazosin (P=0.006) and finasteride (P<0.001) alone. conclusions Long-term combination therapy with doxazosin and finasteride was safe and reduced the risk of overall clinical progression of benign prostatic hyperplasia significantly more than did treatment with either drug alone. Combination therapy and finasteride alone reduced the long-term risk of acute urinary retention and the need for invasive therapy.
TL;DR: In this article, the authors demonstrate the localized surface plasmon resonance λmax response of individual Ag nanoparticles to the formation of a monolayer of small-molecule adsorbates.
Abstract: This work utilizes dark-field optical microscopy to demonstrate the localized surface plasmon resonance λmax response of individual Ag nanoparticles to the formation of a monolayer of small-molecule adsorbates. The adsorption of fewer than 60 000 1-hexadecanethiol molecules on single Ag nanoparticles results in a localized surface plasmon resonance shift of 40.7 nm. Additionally, the kinetics of the single nanoparticle response was shown to be comparable to that of other real-time sensor technologies.
TL;DR: It is demonstrated that the previously described photoinduced method for converting silver nanospheres into triangular silver nanocrystals—so-called nanoprisms—can be extended to synthesize relatively monodisperse nanoprism with desired edge lengths in the 30–120 nm range.
Abstract: Inorganic nanoparticles exhibit size-dependent properties that are of interest for applications ranging from biosensing and catalysis to optics and data storage. They are readily available in a wide variety of discrete compositions and sizes. Shape-selective synthesis strategies now also yield shapes other than nanospheres, such as anisotropic metal nanostructures with interesting optical properties. Here we demonstrate that the previously described photoinduced method for converting silver nanospheres into triangular silver nanocrystals--so-called nanoprisms--can be extended to synthesize relatively monodisperse nanoprisms with desired edge lengths in the 30-120 nm range. The particle growth process is controlled using dual-beam illumination of the nanoparticles, and appears to be driven by surface plasmon excitations. We find that, depending on the illumination wavelengths chosen, the plasmon excitations lead either to fusion of nanoprisms in an edge-selective manner or to the growth of the nanoprisms until they reach their light-controlled final size.
TL;DR: A decoy-pulse method to overcome the photon-number-splitting attack for Bennett-Brassard 1984 quantum key distribution protocol in the presence of high loss by intentionally and randomly replacing signal pulses by multiphoton pulses (decoy pulses).
Abstract: We propose a decoy-pulse method to overcome the photon-number-splitting attack for Bennett-Brassard 1984 quantum key distribution protocol in the presence of high loss: A legitimate user intentionally and randomly replaces signal pulses by multiphoton pulses (decoy pulses). Then they check the loss of the decoy pulses. If the loss of the decoy pulses is abnormally less than that of signal pulses, the whole protocol is aborted. Otherwise, to continue the protocol, they estimate the loss of signal multiphoton pulses based on that of decoy pulses. This estimation can be done with an assumption that the two losses have similar values. We justify that assumption.
TL;DR: In this paper, a study of 1631 football players from 15 US colleges found that players with concussions exhibited more severe symptoms (mean GSC score 20.93 [95% confidence interval {CI, 15.65-26.21] points higher than that of controls), cognitive impairments (mean SAC score 2.94 [ 95% CI, 1.41 to 2.06], cognitive functioning improved to baseline levels within 5 to 7 days (day 7 SAC mean difference, −0.33;
Abstract: ContextLack of empirical data on recovery time following sport-related concussion
hampers clinical decision making about return to play after injury.ObjectiveTo prospectively measure immediate effects and natural recovery course
relating to symptoms, cognitive functioning, and postural stability following
sport-related concussion.Design, Setting, and ParticipantsProspective cohort study of 1631 football players from 15 US colleges.
All players underwent preseason baseline testing on concussion assessment
measures in 1999, 2000, and 2001. Ninety-four players with concussion (based
on American Academy of Neurology criteria) and 56 noninjured controls underwent
assessment of symptoms, cognitive functioning, and postural stability immediately,
3 hours, and 1, 2, 3, 5, 7, and 90 days after injury.Main Outcome MeasuresScores on the Graded Symptom Checklist (GSC), Standardized Assessment
of Concussion (SAC), Balance Error Scoring System (BESS), and a neuropsychological
test battery.ResultsNo player with concussion was excluded from participation; 79 players
with concussion (84%) completed the protocol through day 90. Players with
concussion exhibited more severe symptoms (mean GSC score 20.93 [95% confidence
interval {CI}, 15.65-26.21] points higher than that of controls), cognitive
impairment (mean SAC score 2.94 [95% CI, 1.50-4.38] points lower than that
of controls), and balance problems (mean BESS score 5.81 [95% CI, –0.67
to 12.30] points higher than that of controls) immediately after concussion.
On average, symptoms gradually resolved by day 7 (GSC mean difference, 0.33;
95% CI, −1.41 to 2.06), cognitive functioning improved to baseline levels
within 5 to 7 days (day 7 SAC mean difference, −0.03; 95% CI, −1.33
to 1.26), and balance deficits dissipated within 3 to 5 days after injury
(day 5 BESS mean difference, −0.31; 95% CI, −3.02 to 2.40). Mild
impairments in cognitive processing and verbal memory evident on neuropsychological
testing 2 days after concussion resolved by day 7. There were no significant
differences in symptoms or functional impairments in the concussion and control
groups 90 days after concussion.ConclusionsCollegiate football players may require several days for recovery of
symptoms, cognitive dysfunction, and postural instability after concussion.
Further research is required to determine factors that predict variability
in recovery time after concussion. Standardized measurement of postconcussive
symptoms, cognitive functioning, and postural stability may enhance clinical
management of athletes recovering from concussion.
TL;DR: This chapter discusses three infections that are caused by biofilms--infectious kidney stones, bacterial endocarditis, and cystic fibrosis lung infections--and focuses on the role of the biofilm in disease pathogenesis.
Abstract: ▪ Abstract The role of biofilms in the pathogenesis of some chronic human infections is now widely accepted. However, the criteria used to determine whether a given infection is caused by biofilms remain unclear. In this chapter we discuss three infections that are caused by biofilms—infectious kidney stones, bacterial endocarditis, and cystic fibrosis lung infections—and focus on the role of the biofilm in disease pathogenesis. Biofilms are also important as environmental reservoirs for pathogens, and the biofilm growth mode may provide organisms with survival advantages in natural environments and increase their virulence. The consequences of pathogens living in environmental biofilms and an analysis of some specific environmental biofilm systems are presented.
TL;DR: In this article, the authors propose a model of preferences over acts such that the decision maker evaluates acts according to the expectation (over a set of probability measures) of an increasing transformation of an act's expected utility.
Abstract: We propose and axiomatize a model of preferences over acts such that the decision maker evaluates acts according to the expectation (over a set of probability measures) of an increasing transformation of an act's expected utility. This expectation is calculated using a subjective probability over the set of probability measures that the decision maker thinks are relevant given her subjective information. A key feature of our model is that it achieves a separation between ambiguity, identified as a characteristic of the decision maker's subjective information, and ambiguity attitude, a characteristic of the decision maker's tastes. We show that attitudes towards risk are characterized by the shape of the von Neumann-Morgenstern utility function, as usual, while attitudes towards ambiguity are characterized by the shape of the increasing transformation applied to expected utilities. We show that the negative exponential form of this transformation is the special case of constant ambiguity aversion. Ambiguity itself is defined behaviorally and is shown to be characterized by properties of the subjective set of measures. This characterization of ambiguity is formally related to the definitions of subjective ambiguity advanced by Epstein-Zhang (2001) and Ghirardato-Marinacci (2002). One advantage of this model is that the well-developed machinery for dealing with risk attitudes can be applied as well to ambiguity attitudes. The model is also distinct from many in the literature on ambiguity in that it allows smooth, rather than kinked, indifference curves. This leads to different behavior and improved tractability, while still sharing the main features (e.g., Ellsberg's Paradox, etc.). The Maxmin EU model (e.g., Gilboa and Schmeidler (1989)) with a given set of measures may be seen as an extreme case of our model with infinite ambiguity aversion. Two illustrative applications to portfolio choice are offered.
TL;DR: This study suggests thatPlayers with a history of previous concussions are more likely to have future concussive injuries than those with no history; 1 in 15 players with a concussion may have additional concussions in the same playing season; and previous concussion may be associated with slower recovery of neurological function.
Abstract: ContextApproximately 300 000 sport-related concussions occur annually
in the United States, and the likelihood of serious sequelae may increase
with repeated head injury.ObjectiveTo estimate the incidence of concussion and time to recovery after concussion
in collegiate football players.Design, Setting, and ParticipantsProspective cohort study of 2905 football players from 25 US colleges
were tested at preseason baseline in 1999, 2000, and 2001 on a variety of
measures and followed up prospectively to ascertain concussion occurrence.
Players injured with a concussion were monitored until their concussion symptoms
resolved and were followed up for repeat concussions until completion of their
collegiate football career or until the end of the 2001 football season.Main Outcome MeasuresIncidence of concussion and repeat concusion; type and duration of symptoms
and course of recovery among players who were injured with a concussion during
the seasons.ResultsDuring follow-up of 4251 player-seasons, 184 players (6.3%) had a concussion,
and 12 (6.5%) of these players had a repeat concussion within the same season.
There was an association between reported number of previous concussions and
likelihood of incident concussion. Players reporting a history of 3 or more
previous concussions were 3.0 (95% confidence interval, 1.6-5.6) times more
likely to have an incident concussion than players with no concussion history.
Headache was the most commonly reported symptom at the time of injury (85.2%),
and mean overall symptom duration was 82 hours. Slowed recovery was associated
with a history of multiple previous concussions (30.0% of those with ≥3
previous concussions had symptoms lasting >1 week compared with 14.6% of those
with 1 previous concussion). Of the 12 incident within-season repeat concussions,
11 (91.7%) occurred within 10 days of the first injury, and 9 (75.0%) occurred
within 7 days of the first injury.ConclusionsOur study suggests that players with a history of previous concussions
are more likely to have future concussive injuries than those with no history;
1 in 15 players with a concussion may have additional concussions in the same
playing season; and previous concussions may be associated with slower recovery
of neurological function.
TL;DR: Three experiments investigated the hypothesis that power increases an action orientation in the power holder, even in contexts where power is not directly experienced, suggesting that the experience of power leads to the performance of goal-directed behavior.
Abstract: Three experiments investigated the hypothesis that power increases an action orientation in the power holder, even in contexts where power is not directly experienced. In Experiment 1, participants who possessed structural power in a group task were more likely to take a card in a simulated game of blackjack than those who lacked power. In Experiment 2, participants primed with high power were more likely to act against an annoying stimulus (a fan) in the environment, suggesting that the experience of power leads to the performance of goal-directed behavior. In Experiment 3, priming high power led to action in a social dilemma regardless of whether that action had prosocial or antisocial consequences. The effects of priming power are discussed in relation to the broader literature on conceptual and mind-set priming.
TL;DR: Having knowledge of transglutaminases is essential for understanding the aetiologies of diverse hereditary diseases of the blood and skin, and various autoimmune, inflammatory and degenerative conditions.
Abstract: Blood coagulation, skin-barrier formation, hardening of the fertilization envelope, extracellular-matrix assembly and other important biological processes are dependent on the rapid generation of covalent crosslinks between proteins. These reactions--which are catalysed by transglutaminases--endow the resulting supramolecular structure with extra rigidity and resistance against proteolytic degradation. Some transglutaminases function as molecular switches in cytoskeletal scaffolding and modulate protein-protein interactions. Having knowledge of these enzymes is essential for understanding the aetiologies of diverse hereditary diseases of the blood and skin, and various autoimmune, inflammatory and degenerative conditions.
Wake Forest University1, National Institutes of Health2, George Washington University3, Wayne State University4, University of Tennessee Health Science Center5, University of Chicago6, University of Alabama7, University of Cincinnati8, Columbia University9, University of Utah10, University of Texas Southwestern Medical Center11, University of Pittsburgh12, Ohio State University13, Thomas Jefferson University14, University of Texas at San Antonio15, University of Miami16, Brown University17, Case Western Reserve University18, University of Texas at Austin19, University of North Carolina at Chapel Hill20, Northwestern University21
TL;DR: In this paper, a double-blind, placebo-controlled trial involving pregnant women with a documented history of spontaneous preterm delivery was conducted, where women were enrolled at 19 clinical centers at 16 to 20 weeks of gestation.
Abstract: Background Women who have had a spontaneous preterm delivery are at greatly increased risk for preterm delivery in subsequent pregnancies. The results of several small trials have suggested that 17 alpha-hydroxyprogesterone caproate (17P) may reduce the risk of preterm delivery. Methods We conducted a double-blind, placebo-controlled trial involving pregnant women with a documented history of spontaneous preterm delivery. Women were enrolled at 19 clinical centers at 16 to 20 weeks of gestation and randomly assigned by a central data center, in a 2:1 ratio, to receive either weekly injections of 250 mg of 17P or weekly injections of an inert oil placebo; injections were continued until delivery or to 36 weeks of gestation. The primary outcome was preterm delivery before 37 weeks of gestation. Analysis was performed according to the intention-to-treat principle. Results Base-line characteristics of the 310 women in the progesterone group and the 153 women in the placebo group were similar. Treatment with 1...
TL;DR: This article argued that women have some advantages in typical leadership style but suffer some disadvantages from prejudicial evaluations of their competence as leaders, especially in masculine organizational contexts, and pointed out that women are more likely than men to lead in a style that is effective under contemporary conditions.
Abstract: Journalists and authors of trade books increasingly assert a female advantage in leadership, whereby women are more likely than men to lead in a style that is effective under contemporary conditions. Contrasting our analysis of these claims with Vecchio's [Leadersh. Q. 13 (2002) 643] analysis, we show that women have some advantages in typical leadership style but suffer some disadvantages from prejudicial evaluations of their competence as leaders, especially in masculine organizational contexts. Nonetheless, more women are rising into leadership roles at all levels, including elite executive roles. We suggest reasons for this rise and argue that organizations can capture the symbols of progressive social change and modernity by appointments of women in key positions.
TL;DR: In this paper, contrast-enhanced cardiovascular magnetic resonance (CMR) and single photon emission computed tomography (SPECT) myocardial perfusion imaging was used to detect sub-endocardial infarcts that are missed by SPECT.
TL;DR: The Functional Assessment of Chronic Illness Therapy (FACIT) Measurement System is a collection of health-related quality of life questionnaires targeted to the management of chronic illness.
Abstract: The Functional Assessment of Chronic Illness Therapy (FACIT) Measurement System is a collection of health-related quality of life (HRQOL) questionnaires targeted to the management of chronic illness. The measurement system, under development since 1987, began with the creation of a generic CORE questionnaire called the F unctional A ssessment of C ancer T herapy-G eneral (FACT-G). The FACT-G (now in Version 4) is a 27-item compilation of general questions divided into four primary QOL domains: Physical Well-Being, Social/Family Well-Being, Emotional Well-Being, and Functional Well-Being. It is appropriate for use with patients with any form of cancer, and extensions of it have been used and validated in other chronic illness condition (e.g., HIV/AIDS; multiple sclerosis; Parkinson's disease; rheumatoid arthritis), and in the general population. The FACIT Measurement System now includes over 400 questions, some of which have been translated into more than 45 languages. Assessment of any one patient is tailored so that the most-relevant questions are asked and administration time for any one assessment is usually less than 15 minutes. This is accomplished both by the use of specific subscales for relevant domains of HRQOL, or computerized adaptive testing (CAT) of selected symptoms and functional areas. FACIT questionnaires can be administered by self-report (paper or computer) or interview (face-to-face or telephone). Available scoring, normative data and information on meaningful change now allow one to interpret results in the context of a growing literature base.
TL;DR: The authors found that on average, religious beliefs are associated with "good" economic attitudes, where ''good'' is defined as conducive to higher per capita income and growth, while religious people tend to be more racist and less favorable with respect to working women.
TL;DR: Ubiquitin-binding proteins such as epsins, Hrs, and Vps9 are monoubiquitinated, indicating the general nature of ubiquitin regulation in endocytosis and suggesting new models to explain how recognition of monoubquitin signals may be regulated.
Abstract: Ubiquitin regulates protein transport between membrane compartments by serving as a sorting signal on protein cargo and by controlling the activity of trafficking machinery. Monoubiquitin attached to integral plasma membrane proteins or to associated transport modifiers serves as a regulated signal for internalization into the endocytic pathway. Similarly, monoubiquitin attached to biosynthetic and endocytic membrane proteins is a signal for sorting of cargo into vesicles that bud into the late endosome lumen for delivery into the lysosome. Ubiquitination of trans-acting endocytic proteins is also required for transport, and key endocytic proteins are modified by monoubiquitin. Regulatory enzymes of the ubiquitination machinery, ubiquitin ligases, control the timing and specificity of plasma membrane protein downregulation in such diverse biological processes as cell fate specification and neurotransmission. Monoubiquitin signals appended by these ligases are recognized by endocytic proteins carrying ubiquitin-binding motifs, including UBA, UEV, UIM, and CUE domains. The UIM proteins epsins and Hrs are excellent candidates for adaptors that link ubiquitinated cargo to the clathrin-based sorting machinery at appropriate regions of the endosomal or plasma membranes. Other ubiquitin-binding proteins also play crucial roles in cargo transport, although in most cases the role of ubiquitin-binding is not defined. Ubiquitin-binding proteins such as epsins, Hrs, and Vps9 are monoubiquitinated, indicating the general nature of ubiquitin regulation in endocytosis and suggesting new models to explain how recognition of monoubiquitin signals may be regulated.
TL;DR: In this article, identity movements that seek to expand individual autonomy as motors of institutional change are depicted. But they do not consider the role identities of actors in these movements, and instead focus on the sociopolitical legitimacy of activists, the extent of theorization of new roles, prior defections by peers to the new logic, and gains to prior defectors act as identity-discrepant cues.
Abstract: A challenge facing cultural-frame institutionalism is to explain how existing institutional logics and role identities are replaced by new logics and role identities. This article depicts identity movements that strive to expand individual autonomy as motors of institutional change. It proposes that the sociopolitical legitimacy of activists, extent of theorization of new roles, prior defections by peers to the new logic, and gains to prior defectors act as identity-discrepant cues that induce actors to abandon traditional logics and role identities for new logics and role identities. A study of how the nouvelle cuisine movement in France led elite chefs to abandon classical cuisine during the period starting from 1970 and ending in 1997 provides wide-ranging support for these arguments. Implications for research on institutional change, social movements, and social identity are outlined
TL;DR: This article explored the effect of spouses' contribution to family income on how housework is divided and found that women decrease their housework as their earnings increase, up to the point where both spouses contribute equally to income.
Abstract: Using data from Australia and the United States, the authors explore the effect of spouses’ contribution to family income on how housework is divided. Consistent with exchange‐bargaining theory, women decrease their housework as their earnings increase, up to the point where both spouses contribute equally to income. In other respects, gender trumps money. The base level of housework for women is much higher. Among the small percentage of couples who are in the range where women provide 51%–100% of household income, the change in housework is opposite what exchange theory predicts: couples that deviate from the normative income standard (men make more money than women) seem to compensate with a more traditional division of household work.