cssi/SciSciGPT-SciSciNet huggingface dataset:
Microtubule dynamic instability: the role of cracks between protofilaments.

Microtubules (MTs) are cytoplasmic protein polymers that are essential for fundamental cellular processes including the maintenance of cell shape, organelle transport and formation of the mitotic spindle. Microtubule dynamic instability is critical for these processes, but it remains poorly understood, in part because the relationship between the structure of the MT tip and the growth/depolymerization transitions is enigmatic. In previous work, we used computational models of dynamic instability to provide evidence that cracks (laterally unbonded regions) between protofilaments play a key role in the regulation of dynamic instability. Here we use computational models to investigate the connection between cracks and dynamic instability in more detail. Our work indicates that while cracks contribute to dynamic instability in a fundamental way, it is not the depth of the cracks per se that governs MT dynamic instability. Instead, what matters more is whether the cracks terminate in GTP-rich or GDP-rich regions of the MT. Based on these observations, we suggest that a functional “GTP cap” (i.e., one capable of promoting MT growth) is one where the cracks terminate in pairs of GTP-bound subunits, and that the likelihood of catastrophe rises significantly with the fraction of crack-terminating subunits that contain GDP. In addition to helping clarify the mechanism of dynamic instability, this idea could also explain how MT stabilizers work: proteins that introduce lateral cross-links between protofilaments would produce islands of GDP-bound tubulin that mimic GTP-rich regions in having strong lateral bonds, thus reducing crack propagation, suppressing catastrophe and promoting rescue.
Hypermultiplet moduli space and three dimensional gauge theories

We establish a relation, conjectured recently by E. Witten, between the hypermultiplet moduli space in compactifications of the heterotic string on an A-D-E singularities, and the moduli spaces of three-dimensional pure gauge theories with the corresponding A-D-E gauge groups. It is possible to add a bounded number of heterotic fivebranes sitting in the singularity, while (in leading order in α') keeping the heterotic string perturbative. The corresponding hypermultiplet moduli space is given by the moduli space of a three-dimensional gauge theory with matter.
Groupoids, Frobenius Algebras and Poisson Sigma Models

This note is devoted to report some results proven in [5, 8] and some work in progress [6] concerning the relation between groupoids and Frobenius algebras specialized in the case of Poisson sigma models with boundary. We prove a correspondence between groupoids in Set and relative Frobenius algebras in Rel, as well as an adjunction between a special type of semigroupoids and relative H*-algebras. The connection between groupoids and Frobenius algebras is made explicit by introducing what we called weak monoids and relational symplectic groupoids, in the context of Poisson sigma models with boundary and in particular, describing such structures in the extended symplectic category and the category of Hilbert spaces. This is part of a joint work with Alberto Cattaneo and Chris Heunen.
Rigidity of outermost MOTS: the initial data version

In the paper Commun Anal Geom 16(1):217–229, 2008, a rigidity result was obtained for outermost marginally outer trapped surfaces (MOTSs) that do not admit metrics of positive scalar curvature. This allowed one to treat the “borderline case” in the author’s work with R. Schoen concerning the topology of higher dimensional black holes (Commun Math Phys 266(2):571–576, 2006). The proof of this rigidity result involved bending the initial data manifold in the vicinity of the MOTS within the ambient spacetime. In this note we show how to circumvent this step, and thereby obtain a pure initial data version of this rigidity result and its consequence concerning the topology of black holes.
Conformal field theories and compact curves in moduli spaces

We show that there are many compact subsets of the moduli space Mg of Riemann surfaces of genus g that do not intersect any symmetry locus. This has interesting implications for $$ \mathcal{N}=2 $$ supersymmetric conformal field theories in four dimensions.
Single crystal growth by the traveling solvent technique: A review

Abstract A description is given of the traveling solvent technique, which has been used for the crystal growth of both congruently and incongruently melting materials of many classes of intermetallic, chalcogenide, semiconductor and oxide materials. The use of a solvent, growth at lower temperatures and the zoning process, that are inherent ingredients of the method, can help to grow large, high structural quality, high purity crystals. In order to optimize this process, careful control of the various growth variables is imperative; however, this can be difficult to achieve due to the large number of independent experimental parameters that can be grouped under the broad headings ‘growth conditions’, ‘characteristics of the material being grown’, and ‘experimental configuration, setup and design’. This review attempts to describe the principles behind the traveling solvent technique and the various experimental variables. Guidelines are detailed to provide the information necessary to allow closer control of the crystal growth process through a systematic approach. Comparison is made between the traveling solvent technique and other crystal growth methods, in particular the more conventional stationary flux method. The use of optical heating is described in detail and successful traveling solvent growth by optical heating is reported for the first time for crystals of Tl 5 Te 3 , Cd 3 As 2 , and FeSc 2 S 4 (using Te, Cd and FeS fluxes, respectively).
Time scales of supercooled water and implications for reversible polyamorphism

Deeply supercooled water exhibits complex dynamics with large density fluctuations, ice coarsening and characteristic time scales extending from picoseconds to milliseconds. Here, we discuss implications of these time scales as they pertain to two-phase coexistence and to molecular simulations of supercooled water. Specifically, we argue that it is possible to discount liquid–liquid criticality because the time scales imply that correlation lengths for such behaviour would be bounded by no more than a few nanometres. Similarly, it is possible to discount two-liquid coexistence because the time scales imply a bounded interfacial free energy that cannot grow in proportion to a macroscopic surface area. From time scales alone, therefore, we see that coexisting domains of differing density in supercooled water can be no more than nanoscale transient fluctuations.
Exact results for the infinite supersymmetric extensions of the infinite square well

One-dimensional potentials defined by $V^{(S)}(x) =S(S+1) \hbar^2 \pi^2 /[2ma^2\sin^2(\pi x/a)]$ (for integer $S$) arise in the repeated supersymmetrization of the infinite square well, here defined over the region $(0,a)$. We review the derivation of this hierarchy of potentials and then use the methods of supersymmetric quantum mechanics, as well as more familiar textbook techniques, to derive compact closed-form expressions for the normalized solutions, $\psi_n^{(S)}(x)$, for all $V^{(S)}(x)$ in terms of well-known special functions in a pedagogically accessible manner. We also note how the solutions can be obtained as a special case of a family of shape-invariant potentials, the trigonometric Poschl-Teller potentials, which can be used to confirm our results. We then suggest additional avenues for research questions related to, and pedagogical applications of, these solutions, including the behavior of the corresponding momentum-space wave functions $\phi_n^{(S)}(p)$ for large $|p|$ and general questions about the supersymmetric hierarchies of potentials which include an infinite barrier.
Time-distance helioseismology of two realistic sunspot simulations

Linear time-distance helioseismic inversions are carried out using several filtering schemes to determine vector flow velocities within two ∼100{sup 2} Mm{sup 2} × 20 Mm realistic magnetohydrodynamic sunspot simulations of 25 hr. One simulation domain contains a model of a full sunspot (i.e., one with both an umbra and penumbra), while the other contains a pore (i.e., a spot without a penumbra). The goal is to test current helioseismic methods using these state-of-the-art simulations of magnetic structures. We find that horizontal flow correlations between inversion and simulation flow maps are reasonably high (∼0.5-0.8) in the upper 3 Mm at distances exceeding 25-30 Mm from spot center, but are substantially lower at smaller distances and larger depths. Inversions of forward-modeled travel times consistently outperform those of our measured travel times in terms of horizontal flow correlations, suggesting that our inability to recover flow structure near these active regions is largely due to the fact that we are unable to accurately measure travel times near strong magnetic features. In many cases the velocity amplitudes from the inversions underestimate those of the simulations by up to 50%, possibly indicating nonlinearity of the forward problem. In every case, we find that our inversions aremore » unable to recover the vertical flow structure of the simulations at any depth.« less
A heuristic for the distribution of point counts for random curves over a finite field

How many rational points are there on a random algebraic curve of large genus g over a given finite field Fq? We propose a heuristic for this question motivated by a (now proven) conjecture of Mumford on the cohomology of moduli spaces of curves; this heuristic suggests a Poisson distribution with mean q+1+1/(q-1). We prove a weaker version of this statement in which g and q tend to infinity, with q much larger than g.
Weyl gauge-vector and complex dilaton scalar for conformal symmetry and its breaking

Instead of the scalar “dilaton” field that is usually adopted to construct conformally invariant Lagrangians for gravitation, we here propose a hybrid construction, involving both a complex dilaton scalar and a Weyl gauge-vector, in accord with Weyl’s original concept of a non-Riemannian conformal geometry with a transport law for length and time intervals, for which this gauge vector is required. Such a hybrid construction permits us to avoid the wrong sign of the dilaton kinetic term (the ghost problem) that afflicts the usual construction. The introduction of a Weyl gauge-vector and its interaction with the dilaton also has the collateral benefit of providing an explicit mechanism for spontaneous breaking of the conformal symmetry, whereby the dilaton and the Weyl gauge-vector acquire masses somewhat smaller than $$\textit{m}_\textit{P}$$ by the Coleman–Weinberg mechanism. Conformal symmetry breaking is assumed to precede inflation, which occurs later by a separate GUT or electroweak symmetry breaking, as in inflationary models based on the Higgs boson.
Improving Big Data visual analytics with interactive virtual reality

For decades, the growth and volume of digital data collection has made it challenging to digest large volumes of information and extract underlying structure. Coined ‘Big Data’, massive amounts of information has quite often been gathered inconsistently (e.g from many sources, of various forms, at different rates, etc.). These factors impede the practices of not only processing data, but also analyzing and displaying it in an efficient manner to the user. Many efforts have been completed in the data mining and visual analytics community to create effective ways to further improve analysis and achieve the knowledge desired for better understanding. Our approach for improved big data visual analytics is two-fold, focusing on both visualization and interaction. Given geo-tagged information, we are exploring the benefits of visualizing datasets in the original geospatial domain by utilizing a virtual reality platform. After running proven analytics on the data, we intend to represent the information in a more realistic 3D setting, where analysts can achieve an enhanced situational awareness and rely on familiar perceptions to draw in-depth conclusions on the dataset. In addition, developing a human-computer interface that responds to natural user actions and inputs creates a more intuitive environment. Tasks can be performed to manipulate the dataset and allow users to dive deeper upon request, adhering to desired demands and intentions. Due to the volume and popularity of social media, we developed a 3D tool visualizing Twitter on MIT's campus for analysis. Utilizing emerging technologies of today to create a fully immersive tool that promotes visualization and interaction can help ease the process of understanding and representing big data.
Spin-selective AC Stark shifts in a charged quantum dot

A strong, far-detuned laser can shift the energy levels of an optically active quantum system via the AC Stark effect. We demonstrate that the polarization of the laser results in a spin-selective modification to the energy structure of a charged quantum dot, shifting one spin manifold but not the other. An additional shift occurs due to the Overhauser field of the nuclear spins, which are pumped into a partially polarized state. This mechanism offers a potentially rapid, reversible, and coherent control of the energy structure and polarization selection rules of a charged quantum dot.
Classification of certain inductive limit actions of compact groups on AF algebras

Let A = lim→An be an AF algebra, G be a compact group. We consider inductive limit actions of the form α = lim→αn, where αn: G ↷ An is an action on the finite-dimensional C*-algebra An which fixes ...
Ulcerative Colitis-Derived Colonoid Culture: A Multi-Mineral-Approach to Improve Barrier Protein Expression.

Background Recent studies demonstrated that Aquamin®, a calcium-, magnesium-rich, multi-mineral natural product, improves barrier structure and function in colonoids obtained from the tissue of healthy subjects. The goal of the present study was to determine if the colonic barrier could be improved in tissue from subjects with ulcerative colitis (UC). Methods Colonoid cultures were established with colon biopsies from 9 individuals with UC. The colonoids were then incubated for a 2-week period under control conditions (in culture medium with a final calcium concentration of 0.25 mM) or in the same medium supplemented with Aquamin® to provide 1.5 - 4.5 mM calcium. Effects on differentiation and barrier protein expression were determined using several approaches: phase-contrast and scanning electron microscopy, quantitative histology and immunohistology, mass spectrometry-based proteome assessment and transmission electron microscopy. Results Although there were no gross changes in colonoid appearance, there was an increase in lumen diameter and wall thickness on histology and greater expression of cytokeratin 20 (CK20) along with reduced expression of Ki67 by quantitative immunohistology observed with intervention. In parallel, upregulation of several differentiation-related proteins was seen in a proteomic screen with the intervention. Aquamin®-treated colonoids demonstrated a modest up-regulation of tight junctional proteins but stronger induction of adherens junction and desmosomal proteins. Increased desmosomes were seen at the ultrastructural level. Proteomic analysis demonstrated increased expression of several basement membrane proteins and hemidesmosomal components. Proteins expressed at the apical surface (mucins and trefoils) were also increased as were several additional proteins with anti-microbial activity or that modulate inflammation. Finally, several transporter proteins that affect electrolyte balance (and, thereby affect water resorption) were increased. At the same time, growth and cell cycle regulatory proteins (Ki67, nucleophosmin, and stathmin) were significantly down-regulated. Laminin interactions, matrix formation and extracellular matrix organization were the top three up-regulated pathways with the intervention. Conclusion A majority of individuals including patients with UC do not reach the recommended daily intake for calcium and other minerals. To the extent that such deficiencies might contribute to the weakening of the colonic barrier, the findings employing UC tissue-derived colonoids here suggest that adequate mineral intake might improve the colonic barrier.
Log-Logarithmic Time Pruned Polar Coding

A pruned variant of polar coding is proposed for binary erasure channel (BEC). Fix any BEC. For sufficiently small $\varepsilon >{0}$ , we construct a series of capacity achieving codes with block length $\text {N}=\varepsilon ^{-{4.9}}$ , code rate $\text {R}=\text {Capacity}-\text {O}(\varepsilon)$ , block error probability $\text {P}=\varepsilon $ , and encoding and decoding time complexity $\mathop {\mathrm {bC}} =\text {O}(\log \lvert \log \varepsilon \rvert)$ per information bit. The given per-bit complexity $\mathop {\mathrm {bC}} $ is log-logarithmic in N, in $\text {Capacity}-\text {R}$ , and in P. Beyond BEC, there is a generalization: Fix a prime q and fix a symmetric, q-ary-input, discrete-output memoryless channel. For sufficiently small $\varepsilon >0$ , we construct a series of error correction codes with block length $\text {N}=\varepsilon ^{-\text {constant}}$ , code rate $\text {R}=\text {Capacity}-\text {O}(\varepsilon)$ , block error probability $\text {P}=\varepsilon $ , and encoding and decoding time complexity $\mathop {\mathrm {bC}} =\text {O}(\log \lvert \log \varepsilon \rvert)$ per information bit. Over general channels, this family of codes has the lowest per-bit time complexity among all capacity-achieving codes known to date.
DisQ: a novel quantum output state classification method on IBM quantum computers using openpulse

Superconducting quantum computing technology has ushered in a new era of computational possibilities. While a considerable research effort has been geared toward improving the quantum technology and building the software stack to efficiently execute quantum algorithms with reduced error rate, effort toward optimizing how quantum output states are defined and classified for the purpose of reducing the error rate is still limited. To this end, this paper proposes DisQ, a quantum output state classification approach which reduces error rates of quantum programs on NISQ devices.
Comparison of COVID-19 infections among healthcare workers and non-healthcare workers.

Objectives Healthcare workers face distinct occupational challenges that affect their personal health, especially during a pandemic. In this study we compare the characteristics and outcomes of Covid-19 patients who are and who are not healthcare workers (HCW). Methods We retrospectively analyzed a cohort of 2,842 adult patients with known HCW status and a positive SARS-CoV-2 RT-PCR test presenting to a large academic medical center emergency department (ED) in New York State from March 21 2020 through June 2020. Early in the pandemic we instituted a policy to collect data on patient occupation and exposures to suspected Covid-19. The primary outcome was hospital admission. Secondary outcomes were ICU admission, need for invasive mechanical ventilation (IMV), and mortality. We compared baseline characteristics and outcomes of Covid-19 adult patients based on whether they were or were not HCW using univariable and multivariable analyses. Results Of 2,842 adult patients (mean age 53+/-19 years, 53% male) 193 (6.8%) were HCWs and 2,649 (93.2%) were not HCWs. Compared with non-HCW, HCWs were younger (43 vs 53 years, P<0.001), more likely female (118/193 [61%] vs 1211/2649 [46%], P<0.001), and more likely to have a known Covid-19 exposure (161/193 [83%] vs 946/2649 [36%], P<0.001), but had fewer comorbidities. On presentation to the ED, HCW also had lower frequencies of tachypnea (12/193 [6%] vs 426/2649 [16%], P<0.01), hypoxemia (15/193 [8%] vs 564/2649 [21%], P<0.01), bilateral opacities on imaging (38/193 [20%] vs 1189/2649 [45%], P<0.001), and lymphocytopenia (6/193 [3%] vs 532/2649 [20%], P<0.01) compared to non-HCWs. Direct discharges home from the ED were more frequent in HCW 154/193 (80%) vs 1275/2649 (48%) p<0.001). Hospital admissions (38/193 [20%] vs 1264/2694 [47%], P<0.001), ICU admissions (7/193 [3%] vs 321/2694 [12%], P<0.001), need for IMV (6/193 [3%] vs 321/2694 [12%], P<0.001) and mortality (2/193 [1%] vs 219/2694 [8%], P<0.01) were lower than among non-HCW. After controlling for age, sex, comorbidities, presenting vital signs and radiographic imaging, HCW were less likely to be admitted (OR 0.6, 95%CI 0.3–0.9) than non HCW. Conclusions Compared with non HCW, HCW with Covid-19 were younger, had less severe illness, and were less likely to be admitted.
Strengthening policy coding methodologies to improve COVID-19 disease modeling and policy responses: a proposed coding framework and recommendations.

In recent months, multiple efforts have sought to characterize COVID-19 social distancing policy responses. These efforts have used various coding frameworks, but many have relied on coding methodologies that may not adequately describe the gradient in social distancing policies as states “re-open.” We developed a COVID-19 social distancing intensity framework that is sufficiently specific and sensitive to capture this gradient. Based on a review of policies from a 12 U.S. state sample, we developed a social distancing intensity framework consisting of 16 domains and intensity scales of 0–5 for each domain. We found that the states with the highest average daily intensity from our sample were Pennsylvania, Washington, Colorado, California, and New Jersey, with Georgia, Florida, Massachusetts, and Texas having the lowest. While some domains (such as restaurants and movie theaters) showed bimodal policy intensity distributions compatible with binary (yes/no) coding, others (such as childcare and religious gatherings) showed broader variability that would be missed without more granular coding. This detailed intensity framework reveals the granularity and nuance between social distancing policy responses. Developing standardized approaches for constructing policy taxonomies and coding processes may facilitate more rigorous policy analysis and improve disease modeling efforts.
The association between substance use and risky sexual behaviors among middle school children

Objective: The objective of the study was to determine if there was a significant association between substance use and risky sexual behaviors among middle school children.Methods: Data were collected in May 2002 using a questionnaire. A chi-square test was used for data analysis.Results: The results showed that alcohol, cocaine, marijuana, and tobacco use are strong predictors of risky sexual behaviors.Conclusions: These findings will be of use to healthcare practitioners and health educators seeking to reduce the risk of infection with HIV and other sexually transmitted diseases among the middle school children.
On the Competitive Analysis and High Accuracy Optimality of Profile Maximum Likelihood

A striking result of [Acharya et al. 2017] showed that to estimate symmetric properties of discrete distributions, plugging in the distribution that maximizes the likelihood of observed multiset of frequencies, also known as the profile maximum likelihood (PML) distribution, is competitive compared with any estimators regardless of the symmetric property. Specifically, given $n$ observations from the discrete distribution, if some estimator incurs an error $\varepsilon$ with probability at most $\delta$, then plugging in the PML distribution incurs an error $2\varepsilon$ with probability at most $\delta\cdot \exp(3\sqrt{n})$. In this paper, we strengthen the above result and show that using a careful chaining argument, the error probability can be reduced to $\delta^{1-c}\cdot \exp(c'n^{1/3+c})$ for arbitrarily small constants $c>0$ and some constant $c'>0$. In particular, we show that the PML distribution is an optimal estimator of the sorted distribution: it is $\varepsilon$-close in sorted $\ell_1$ distance to the true distribution with support size $k$ for any $n=\Omega(k/(\varepsilon^2 \log k))$ and $\varepsilon \gg n^{-1/3}$, which are the information-theoretically optimal sample complexity and the largest error regime where the classical empirical distribution is sub-optimal, respectively. In order to strengthen the analysis of the PML, a key ingredient is to employ novel "continuity" properties of the PML distributions and construct a chain of suitable quantized PMLs, or "coverings". We also construct a novel approximation-based estimator for the sorted distribution with a near-optimal concentration property without any sample splitting, where as a byproduct we obtain better trade-offs between the polynomial approximation error and the maximum magnitude of coefficients in the Poisson approximation of $1$-Lipschitz functions.
Centrality in time-delay consensus networks with structured uncertainties

Abstract We investigate notions of network centrality in terms of the underlying coupling graph of the network, structure of exogenous uncertainties, and communication time-delay. Our focus is on time-delay linear consensus networks, where uncertainty is modeled by structured additive noise on the dynamics of agents. The centrality measures are defined using the H 2 -norm of the network. We quantify the centrality measures as functions of time-delay, the graph Laplacian, and the covariance matrix of the input noise. Several practically relevant uncertainty structures are considered, where we discuss two notions of centrality: one w.r.t intensity of the noise and the other one w.r.t coupling strength between the agents. Furthermore, explicit formulas for the centrality measures are obtained for all types of uncertainty structures. Lastly, we rank agents and communication links based on their centrality indices and highlight the role of time-delay and uncertainty structure in each scenario. Our counter-intuitive grasp is that some of centrality measures are highly volatile with respect to time-delay.
Resolving Confusion Over Third-Order Accuracy of U-MUSCL

In this paper, we discuss the U-MUSCL reconstruction scheme -- an unstructured-grid extension of Van Leer's kappa-scheme -- proposed by Burg for the edge-based discretization [AIAA Paper 2005-4999]. This technique has been widely used in practical unstructured-grid fluid-dynamics solvers but with confusions: e.g., third-order accuracy with kappa=1/2 or kappa=1/3. This paper clarifies some of these confusions: e.g., the U-MUSCL scheme can be third-order accurate in the point-valued solution with kappa=1/3 on regular grids for linear equations in all dimensions, it can be third-order accurate with kappa=1/2 as the QUICK scheme in one dimension. It is shown that the U-MUSCL scheme cannot be third-order accurate for nonlinear equations, except a very special case of kappa=1/2 on regular simplex-element grids, but it can be an accurate low-dissipation second-order scheme. It is also shown that U-MUSCL extrapolates a quadratic function exactly with kappa=1/2 on arbitrary grids provided the gradient is computed by a quadratic least-squares method. Two techniques are discussed, which transform the U-MUSCL scheme into being genuinely third-order accurate on a regular grid: an efficient flux-reconstruction method and a special source term quadrature formula for kappa=1/2.
Multicomponent CASSCF Revisited: Large Active Spaces Are Needed for Qualitatively Accurate Protonic Densities.

Multicomponent methods seek to treat select nuclei, typically protons, fully quantum mechanically and equivalent to the electrons of a chemical system. In such methods, it is well-known that due to...
The practical application of the magnetic virial theorem

The magnetic virial theorem states that the magnetic energy contained in a coronal force-free magnetic field is given by a surface integral at the photospheric boundary involving the three vector magnetic field components. It is possible to use this theorem together with vector magnetograph data to compute the magnetic energy of solar active regions. In particular, one might compute the energy of an active region both before and after a flare occurs to determine whether the energy observed to be released during the flare is actually extracted from the magnetic field, as is commonly believed
Coxsackievirus B3 Infection Early in Pregnancy Induces Congenital Heart Defects Through Suppression of Fetal Cardiomyocyte Proliferation

Background Coxsackievirus B (CVB) is the most common cause of viral myocarditis. It targets cardiomyocytes through coxsackie and adenovirus receptor, which is highly expressed in the fetal heart. We hypothesized CVB3 can precipitate congenital heart defects when fetal infection occurs during critical window of gestation. Methods and Results We infected C57Bl/6 pregnant mice with CVB3 during time points in early gestation (embryonic day [E] 5, E7, E9, and E11). We used different viral titers to examine possible dose-response relationship and assessed viral loads in various fetal organs. Provided viral exposure occurred between E7 and E9, we observed characteristic features of ventricular septal defect (33.6%), abnormal myocardial architecture resembling noncompaction (23.5%), and double-outlet right ventricle (4.4%) among 209 viable fetuses examined. We observed a direct relationship between viral titers and severity of congenital heart defects, with apparent predominance among female fetuses. Infected dams remained healthy; we did not observe any maternal heart or placental injury suggestive of direct viral effects on developing heart as likely cause of congenital heart defects. We examined signaling pathways in CVB3-exposed hearts using RNA sequencing, Kyoto Encyclopedia of Genes and Genomes enrichment analysis, and immunohistochemistry. Signaling proteins of the Hippo, tight junction, transforming growth factor-β1, and extracellular matrix proteins were the most highly enriched in CVB3-infected fetuses with ventricular septal defects. Moreover, cardiomyocyte proliferation was 50% lower in fetuses with ventricular septal defects compared with uninfected controls. Conclusions We conclude prenatal CVB3 infection induces congenital heart defects. Alterations in myocardial proliferate capacity and consequent changes in cardiac architecture and trabeculation appear to account for most of observed phenotypes.
Modern accounting scholarship: the imperative of positive economic science

The modern era of academic accounting is characterized by the emergence of Positive Economic Science (PES) as the dominant methodology shaping the investigation and understanding of accounting in the academy. This paper briefly describes the history of how this domination came about in the United States and the institutional structure that sustains it. The paper goes on to illustrate the consequence this dominance has had in the form of a radical limiting of our ability to understand accounting phenomena.
Psychological Bias as a Driver of Financial Regulation

I propose here the psychological attraction theory of financial regulation—that regulation is the result of psychological biases on the part of political participants—voters, politicians, bureaucrats, and media commentators; and of regulatory ideologies that exploit these biases. Some key elements of the psychological attraction approach are: salience and vividness, omission bias, scapegoating and xenophobia, fairness and reciprocity norms, overconfidence, and mood effects. This approach further emphasizes emergent effects that arise from the interactions of individuals with psychological biases. For example, availability cascades and ideological replicators have powerful effects on regulatory outcomes.
The pricing of the illiquidity factor’s conditional risk with time-varying premium

Abstract We test the pricing of the conditional systematic risk (β) of IML, a traded liquidity factor of the return premium on illiquid-minus-liquid stocks, with its risk premium varying over time. We find a positive and significant risk premium on conditional βIML, which rises in times of financial distress, measured by the corporate bond yield spread or broker–dealer loans (including margin loans). The conditional βIML remains significantly priced across individual stocks after controlling for the unconditional and conditional βs of the Fama-French and Carhart factors, as well as some common liquidity-based factors.
Justice Scalia on the Use of Foreign Law in Constitutional Interpretation: Unidirectional Monologue or Co-Constitutive Dialogue

This short essay explores Justice Antonin Scalia's conservative alternative approach to recent efforts by other Justices to utilize foreign and international legal sources in the Supreme Court's jurisprudence. It discusses Justice Scalia's writings and remarks over the course of the 2003-2004 Supreme Court Term: On the one hand, Justice Scalia consistently denounced the use of foreign legal sources in constitutional interpretation, both in his concurring opinion in Sosa v. Alvarez-Machain and in his keynote address at the Annual Meeting of the American Society of International Law. On the other hand, in his dissent in Olympic Airways v. Husain, Justice Scalia criticized the majority for failing to give sufficient consideration to foreign court decisions in interpreting the meaning of the Warsaw Convention. He argued that the Court should give considerable deference to prior decisions by the courts of U.S. treaty partners. Drawing on his writings and remarks, this essay explores the possible construction of a conservative alternative approach to transnational judicial dialogue, and evaluates both the practicality and the wisdom of such an approach. It argues that Justice Scalia's approach misunderstands the nature of transnational judicial dialogue: He views it as a unidirectional monologue involving a largely passive role for U.S. courts as mere recipients of foreign legal norms, rather than as a true co-constitutive dialogue in which US court participation can play a role in shaping the content of foreign and international law.
Time nonseparability in aggregate consumption: International evidence

Abstract We study consumption-based asset pricing models which allow for both habit persistence and durability of consumption goods, using quarterly consumption and asset return data for six countries. We estimate the parameters representing habit persistence or durability, risk aversion and time preference for each of the countries. We find that time-nonseparable preferences improve the fit of the model. When the nonseparability parameter is statistically significant, its magnitude indicates that the effect of habit persistence dominates the effect of durability in consumption expenditures. However, the international evidence for habit persistence is weaker than the evidence for the United States.
Endogenous Formation of Joint Ventures with Efficiency Gains

I study stable structures of efficiency-enhancing joint ventures among symmetric firms. Efficiency gains that accrue to a joint venture are assumed to increase with its size. The socially efficient industrywide joint venture is the stable outcome when membership of a joint venture is open to outside firms, but typically not when membership can be restricted. Members of a large joint venture want to restrict membership for strategic reasons -- e.g., in order to keep rival firms' costs high. Side payments among firms do not eliminate the strategic incentives of members of a large joint venture to limit membership
The Composition of Aid and the Fiscal Sector in an Aid-Recipient Economy: A Model

Building on recent work in the fiscal response literature, the present paper develops a new fiscal response model, which, for the first time in the relevant literature, combines the ideas of both endogenous and disaggregated aid. We endogenized aid on the grounds that the recipient government has some influence over aid disbursements. Regarding aid disaggregation, it is argued that each of the main four categories of aid, namely project aid, programme aid, technical assistance and food aid may exert different effects on the recipient economy. Furthermore, in case the preferences of the aid-recipient government are higher for some of these types of aid, neglecting aid disaggregation would lead to aggregation bias in the results and conclusions. The model adds an important new dimension to the vast aid effectiveness literature and calls for further modelling as well as empirical work in this promising research area so that significant policy implications can be derived.
Tensions in deliberative practice: a view from civil society

Based on an interpretive case study of the Southwest Network for Environmental and Economic Justice, this article investigates deliberative democracy by taking a ‘view from civil society’. It examines the Network's efforts to develop policy ideas and transmit them through diverse deliberative spheres and elaborates its ‘dual strategy’ through which it both collaborated with government agents in deliberative forums and took independent action outside them. Analysis of this strategy reveals two tensions in deliberative practice that the Network had to manage in order to transmit its ideas: (1) doing policy advocacy in collaboration with policy elites while staying ‘bottom-up’, and (2) developing policy ideas ‘relevant’ to decision-makers while maintaining the autonomy to be critical. These findings suggest that transmission is a complex process with four dimensions – relational, linguistic, spatial and temporal – that interact to shift power dynamics and create new meanings about policy.
Share Repurchases and the Need for External Finance

We investigate the relationship between the need for external finance and the information content of share repurchases. We find that share repurchase announcement returns increase in the likelihood the firm will need to raise equity in the future. We then examine whether announcement returns to seasoned equity offerings (SEOs) differ when an open market share repurchase precedes the SEO. We hypothesize that repurchases may reduce asymmetric information regarding firm value. In this case, the repurchase mitigates the adverse selection problem associated with issuing equity, and the abnormal return to the SEO announcement should be less negative. We find significantly less negative abnormal returns when the SEO is preceded by a repurchase announcement. We document less negative SEO announcement abnormal returns when the SEO and repurchase announcements are closer in time. We find that compared to other repurchase firms, repurchase firms that are more likely to issue equity have better investment opportunities, have less internally generated cash flow, and face more severe financial constraints. We conclude that payout policy, in the form of stock repurchases, plays a significant role in conveying information about firm value.
Considering Tortious Racism

OF THE UNITED STATES: 2004-2005 193 (124th ed. 2004-2005). 80 FEAGIN & MCKiNNEY, supra note 1, at 42, 48-49. 81 Id. 2005] DEPAUL JOURNAL OF HEALTH CARE LAW of the individual and the community. 82 C. Racial Hostility and Physiological Disparities Critical psychology demonstrates that individuals who perceive the experience of racism experience measurable psychological distress. 83 While those looking at such experiences in the criminal law setting tend to focus on the experience of anger flowing from racism, there are other equally relevant emotions such as hurt, pain and anxiety which the victim of racism experiences. 84 In addition to discrimination at the
Testing Portfolio Efficiency with Conditioning Information

We develop asset pricing models' implications for portfolio efficiency with conditioning information in the form of lagged instruments. A model identifies a portfolio that should be minimum-variance efficient with respect to the conditioning information. Our framework refines tests of portfolio efficiency by using the given conditioning information optimally. The optimal use of the lagged variables is economically important; by using the instruments optimally, we reject several efficiency hypotheses that are not otherwise rejected. The Sharpe ratios of a sample of hedge fund indexes appear consistent with the optimal use of conditioning information. The Author 2009. Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org, Oxford University Press.
Labor unemployment risk and corporate financing decisions

This paper examines the impact of labor unemployment risk on corporate financing decisions. Theory suggests that firms choose conservative financial policies partly as a means of mitigating worker exposure to unemployment risk. Using changes in state unemployment insurance benefit laws as a source of variation in the costs borne by workers during layoff spells, we explore the connection between unemployment risk and the corporate financing decisions of public firms in the United States. We find that increases in legally mandated unemployment benefits lead to increases in corporate leverage. The impact of reduced unemployment risk on financial policy is especially strong for firms that have greater layoff separation rates, labor intensity, and financing constraints. The estimated premium required to compensate workers for unemployment risk due to financial distress is about 57 basis points of firm value for a BBB-rated firm. These findings suggest that labor market frictions have a significant impact on corporate financing decisions.
The value of a good credit reputation: Evidence from credit card renegotiations

I exploit a natural experiment to estimate borrowers’ willingness to pay for a good credit reputation. A lender in Chile offered lower installments to borrowers who were in default. Those who owed more than a fixed arbitrary cutoff were additionally offered a clean public repayment record. Using the cutoff in a fuzzy regression discontinuity design, I show that borrowers are willing to pay the equivalent of 11% of their monthly income for a good reputation. Borrowers use their reputation to take on more debt with other banks, but default more. Thus, renegotiations may impose informational externalities on other lenders.
Fair's Fair: An Argument for Mandatory Disclosure of Technological Protection Measures

The Digital Millennium Copyright Act prohibits users from circumventing technological protection measures employed by copyright owners to control access to their works. It also prohibits the dissemination of devices that facilitate circumvention. Many people believe that the DMCA has upset the traditional balance of protection and access that has traditionally characterized U.S. copyright law. Judicial challenges to the Act are unlikely to succeed and Congress seems convinced that circumvention protection is necessary to facilitate digital commerce. This Article proposes that protection against circumvention be conditioned on a copyright owner’s disclosure to prospective purchasers of the presence and effect of any protective technologies. Market forces may then compel copyright owners to be more judicious in deploying technological protection measures.
Are small stock markets different

Abstract Recent literature has established a positive correlation between financial development and economic growth. While papers such as Bencivenga et al. (J. Econom. Theory 67 (1995) 53) identify potential nonlinearities in this relationship, empirical research to date has allowed for only linear relationships. This paper uses regression tree techniques to investigate whether the partial correlation between growth and financial development differs based on countries’ levels of financial and economic development. As in previous studies, growth and financial development are positively correlated in countries with high levels of market capitalization; however, this relationship does not appear to hold for countries with low levels of market capitalization.
Justice and Accountability: Activist Judging in the Light of Democratic Constitutionalism and Democratic Experimentalism

This article examines the charge that activist judging is inconsistent with democracy in the light of two recent perspectives in legal scholarship. The perspectives – Democratic Constitutionalism and Democratic Experimentalism – suggest in convergent and complementary ways that the charge ignores or oversimplifies relevant features of both judging and democracy. In particular, the charge exaggerates the pre-emptive effect of activist judging, and it implausibly conflates democracy with electoral processes. In addition, it understands consensus as a basis for judicial legitimacy solely in terms of pre-existing agreement and ignores the contingent legitimacy that can arise from the potential for subsequent agreement.
Persistence in Medicare reimbursements and personal medical accounts.

This study uses the Continuous Medicare History Sample (CMHS), a longitudinal sample of Medicare beneficiaries from 1974 to 1997, to identify persistence in Medicare reimbursements. Consistent estimates of Medicare reimbursement persistence are obtained using a dynamic panel Tobit model. Lagged reimbursements are statistically significant in explaining a beneficiary's current year reimbursements, yet their effect is moderate in magnitude. An additional dollar of Medicare spending in the previous year gives rise to $0.19 in spending in the current year for those who have positive expenditures, and the effect ranges between $0.16 and $0.25. Past spending patterns for up to 5 years are also used to evaluate the out-of-sample prediction capabilities of a multi-equation cross-sectional model. Simulated spending patterns for several cohorts are derived and compared to actual spending. The simulated spending distributions are used to study the feasibility of establishing retirement health accounts for Medicare patients.
Should Banks Stress Test Results Be Disclosed?: An Analysis of the Costs and Benefits

Stress tests have become an important component of the supervisory toolkit. However, the extent of disclosure of stress-test results remains controversial. We argue that while stress tests uncover unique information to outsiders — because banks operate in second--best environments with multiple imperfections — there are potential endogenous costs associated with such disclosure.
Financial fraud, director reputation, and shareholder wealth

Abstract We investigate the reputational impact of financial fraud for outside directors based on a sample of firms facing shareholder class action lawsuits. Following a financial fraud lawsuit, outside directors do not face abnormal turnover on the board of the sued firm but experience a significant decline in other board seats held. This decline in other directorships is greater for more severe allegations of fraud and when the outside director bears greater responsibility for monitoring fraud. Interlocked firms that share directors with the sued firm also exhibit valuation declines at the lawsuit filing. Fraud-affiliated directors are more likely to lose directorships at firms with stronger corporate governance and their departure is associated with valuation increases for these firms.