bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk Premia and Preemption in R&D Ventures
Authors: Garlappi Lorenzo
Published: April 2009

I analyze the impact of competition on the risk premia of R&D ventures engaged in a multiple-stage patent race with technical and market uncertainty. After solving in closed form for the case of a two-stage race in continuous time, I show that a firm's risk premium decreases as a consequence of technical progress and increases when a rival pulls ahead. Compared to the case where firms collude, R&D competition erodes the option value to mothball a project, reduces the completion time and the failure rate of R&D, and causes higher and more volatile risk premia. Numerical simulations reveal that competition can generate risk premia up to 500 annual basis points higher and up to three times more volatility than in a collusive industry.
A Binomial Lattice Method for Pricing Corporate Debt and Modeling Chapter 11 Proceedings
Authors: Broadie Mark , Kaya Özgür
Published: April 2009

The pricing of corporate debt is still a challenging and active research area in corporate finance. Starting with Merton (1974), many authors proposed a structural approach in which the value of the assets of the firm is modeled by a stochastic process, and all other variables are derived from this basic process. These structural models have become more complex over time in order to capture more realistic aspects of bankruptcy proceedings. The literature in this area emphasizes closed-form solutions that are derived by either partial differential equation methods or analytical pricing techniques. However, it is not always possible to build a comprehensive model with realistic model features and achieve a closed-form solution at the same time. In this paper, we develop a binomial lattice method that can be used to handle complex structural models such as ones that include Chapter 11 proceedings of the U.S. bankruptcy code. Although lattice methods have been widely used in the option pricing literature, they are relatively new in corporate debt pricing. In particular, the limited liability requirement of the equity holders needs to be handled carefully in this context. Our method can be used to solve the Leland (1994) model and its extension to the finite maturity case, the more complex model of Broadie, Chernov, and Sundaresan (2007), and others.
Systematic Share Price Fluctuations after Bankruptcy Filings and the Investors Who Drive Them
Authors: Dawkins Mark C. , Bhattacharya Nilabhra , Bamber Linda Smith
Published: April 2009

Beginning in the 1990s, firms often continue to trade on the major national exchanges after Chapter 11 bankruptcy filings. For bankruptcies filed from 1993–2003, we find that the more negative the filing period price reaction, the more favorable the immediate post-filing returns, on average. This reversal is not attributable to bid-ask bounce, it holds after controlling for other factors associated with post-filing returns, and it appears more attributable to the activities of large traders than to small traders. Supplementary tests reveal that the pattern of post-filing returns differs significantly for bankruptcies filed in bull versus bear markets. Bankruptcies filed during the 1993 to 1999 bull market enjoy substantial but short-lived reversals averaging one-third of the filing period price plunge. These reversals are inconsistent with efficient assimilation of the bankruptcy information. In contrast, we find no evidence of post-filing reversals for bankruptcies filed from 2000 to 2003.
Underpricing in Discriminatory and Uniform-Price Treasury Auctions
Authors: Goldreich David
Published: April 2009

This paper compares the newer uniform-price U.S. Treasury auctions to the traditional discriminatory mechanism and examines the extent to which the auction mechanisms are responsible for underpricing. Empirically, I find that even for the newer uniform-price auctions, the average price received by the Treasury is less than the price of the same securities in the concurrent secondary market although this underpricing is reduced by half relative to the older mechanism. From the summary statistics released by the Treasury, I calibrate common value auction models for the two mechanisms and predict the level of underpricing in each auction. I find that the observed magnitude of underpricing in the auctions is consistent with the model's predictions.
The Impact of Overnight Periods on Option Pricing
Authors: Boes Mark-Jan , Drost Feike C. , Werker Bas J. M.
Published: April 2009

This paper investigates the effect of closed overnight exchanges on option prices. During the trading day, asset prices follow the literature's standard affine model that allows for stochastic volatility and random jumps. Independently, the overnight asset price process is modeled by a single jump. We find that the overnight component reduces the variation in the random jump process significantly. However, neither the random jumps nor the overnight jumps alone are able to empirically describe all features of option prices. We conclude that both random jumps during the day and overnight jumps are important in explaining option prices, where the latter account for about one quarter of total jump risk.
The Value of Outside Directors: Evidence from Corporate Governance Reform in Korea
Authors: Choi Jongmoo Jay , Park Sae Woon , Yoo Sean Sehyun
Published: April 2009

This paper examines the valuation impacts of outside independent directors in Korea, where a regulation requiring outside directors was instituted after the Asian financial crisis. In contrast to studies of U.S. firms, the effects of independent directors on firm performance are strongly positive. Foreigners also have positive impacts. The effects of indigenous institutions such as chaebol or family control are insignificant or negative. This implies that the effect of outsiders depends on board composition as well as the nature of the market in which the firm operates.
Basis Convergence and Long Memory in Volatility When Dynamic Hedging with Futures
Authors: Dark Jonathan
Published: April 2009

When market returns follow a long memory volatility process, standard approaches to estimating dynamic minimum variance hedge ratios (MVHRs) are misspecified. Simulation results and an application to the S&P 500 index document the magnitude of the misspecification that results from failure to account for basis convergence and long memory in volatility. These results have important implications for the estimation of MVHRs in the S&P 500 example and other markets as well.
Conditional Return Smoothing in the Hedge Fund Industry
Authors: Bollen Nicolas P. B. , Pool Veronika K.
Published: April 2009

We show that if true returns are independently distributed and a manager fully reports gains but delays reporting losses, then reported returns will feature conditional serial correlation. We use conditional serial correlation as a measure of conditional return smoothing. We estimate conditional serial correlation in a large sample of hedge funds. We find that the probability of observing conditional serial correlation is related to the volatility and magnitude of investor cash flows, consistent with conditional return smoothing in response to the risk of capital flight. We also present evidence that conditional serial correlation is a leading indicator of fraud.
The Poor Predictive Performance of Asset Pricing Models
Authors: Simin Timothy
Published: April 2009

This paper examines time-series forecast errors of expected returns from conditional and unconditional asset pricing models for portfolio and individual firm equity returns. A new result that increases predictive precision concerning model specification and forecasting is introduced. Conditional versions of the models generally produce higher mean squared errors than unconditional versions for step ahead prediction. This holds for individual firm data when the instruments are firm specific. Mean square forecast error decompositions indicate that the asset pricing models produce relatively unbiased predictions, but the variance is severe enough to ruin the step ahead predictive ability beyond that of a constant benchmark.
International Diversification with Large- and Small-Cap Stocks
Authors: Eun Cheol S. , Huang Wei , Lai Sandy
Published: April 2009

To the extent that investors diversify internationally, large-cap stocks receive the dominant share of fund allocation. Increasingly, however, returns to large-cap stocks or stock market indices tend to comove, mitigating the benefits from international diversification. In contrast, stocks of locally oriented, small companies do not exhibit the same tendency. In this paper, we assess the potential of small-cap stocks as a vehicle for international portfolio diversification during the period 1980–1999. We show that the extra gains from the augmented diversification with small-cap funds are statistically significant for both in-sample and out-of-sample periods and remain robust to the consideration of market frictions.
Does Insider Trading Impair Market Liquidity? Evidence from IPO Lockup Expirations
Authors: Cao Charles , Field Laura Casares , Hanka Gordon
Published: April 2009

We test the hypothesis that insider trading impairs market liquidity by analyzing intraday trades and quotes around 1,497 IPO lockup expirations in the period 1995–1999. We find that, while lockup expirations are associated with considerable insider trading for some IPO firms, they have little effect on effective spreads. By contrast, two other liquidity measures, quote depth and trading activity, improve substantially. In the 23% of lockup expirations where insiders disclose share sales, spreads actually decline. These findings indicate that a large body of well-informed, blockholding insider traders can enter a market from which they had previously been absent, and substantially change trading volume and share price without impairing market liquidity.
Confidence in the Familiar: An International Perspective
Authors: Li Kai
Published: April 2009

One striking feature of international portfolio investment is the extent to which equity portfolios are concentrated in the domestic equity market of the investor—the home bias puzzle. I examine the role of investors' perception of foreign investment risk on their portfolio choices. The expected returns and risk of foreign investment are specified through an asset pricing model with the home portfolio being the benchmark asset—Pastor's (2000) domestic CAPM. The model serves as a reference point around which investors can center their prior beliefs. I focus on investors' prior beliefs that are consistent with the literature on confidence in the familiar—foreign equities, in terms of both expected returns and risk, being viewed less favorably than domestic equities. These prior beliefs are then combined with the data on G7 equities, and the revised beliefs are used to obtain the global optimal asset allocation. To hold predominantly domestic equities, each G7 investor has to believe that the risk of foreign investment is several times higher than the actual risk. The home bias is more of a puzzle for a U.S. investor during the 1970s. Specifying investors' prior beliefs around the world CAPM does not help resolve the puzzle.
Minority Shareholder Protections and the Private Benefits of Control for Swedish Mergers
Authors: Holmén Martin , Knopf John D.
Published: April 2009

Sweden has a high degree of separation of ownership from control through pyramids, dual-class shares, and cross-holdings. This increases the potential for private benefits of control. However, Sweden's extralegal institutions—tax compliance and newspaper circulation—are consistent with greater shareholder protection. Using data on Swedish mergers we find limited evidence of shareholder expropriation. Apparently, Sweden's extralegal institutions offset the drawback of weak corporate governance.
Limited Stock Market Participation and Asset Prices in a Dynamic Economy
Authors: Guo Hui
Published: April 2009

This paper presents a consumption-based model that explains the equity premium puzzle through two channels. First, because of borrowing constraints, the shareholder cannot completely diversify his income risk and requires a sizable risk premium on stocks. Second, because of limited stock market participation, the precautionary saving demand lowers the risk-free rate but not stock return and generates a substantial liquidity premium. This model also replicates many other salient features of the data, including the first two moments of the risk-free rate, excess stock volatility, stock return predictability, and the unstable relation between stock volatility and the dividend yield.
The Effect of Transaction Size on Off-the-Run Treasury Prices
Authors: Babbel David F. , Merrill Craig B. , Meyer Mark F. , de Villiers Meiring
Published: April 2009

This paper examines intra-day trading data from the inter-dealer broker market for U.S. Treasury securities and measures the degree of price pressure in the off-the-run Treasury market. As is well known, securities that would appear to be very close substitutes, i.e., on-the-run and off-the-run Treasury bonds, behave as if there is some degree of market segmentation. This is the first systematic study of the off-the-run Treasury note and bond market focused entirely on a price pressure effect using intra-day data. The paper analyzes price pressure through matched pairs of securities that differ only in liquidity.
Board Composition, Corporate Performance, and the Cadbury Committee Recommendation
Authors: Dahya Jay , McConnell John J.
Published: April 2009

During the 1990s and beyond, countries around the world witnessed calls and/or mandates for more outside directors on publicly traded companies' boards even though extant studies find no significant correlation between outside directors and corporate performance. We examine the connection between changes in board composition and corporate performance in the U.K. over the interval 1989–1996, a period that surrounds publication of the Cadbury Report, which calls for at least three outside directors for publicly traded corporations. We find that companies that add directors to conform with this standard exhibit a significant improvement in operating performance both in absolute terms and relative to various peer group benchmarks. We also find a statistically significant increase in stock prices around announcements that outside directors were added in conformance with this recommendation. We do not endorse mandated board structures, but the evidence appears to be that such a mandate is associated with an improvement in performance in U.K. companies.
Is Ipo Underperformance a Peso Problem?
Authors: Ang Andrew , Gu Li , Hochberg Yael V.
Published: April 2009

Recent studies suggest that the underperformance of IPOs in the post-1970 sample may be a small sample effect or “Peso problem.” That is, IPO underperformance may result from observing too few star performers ex post than were expected ex ante. We develop a model of IPO performance that captures this intuition by allowing returns to be drawn from mixtures of outstanding, benchmark, or poor performing states. We estimate the model under the null of no ex ante average IPO underperformance and construct small sample distributions of various statistics measuring IPO relative performance. We find that small sample biases are extremely unlikely to account for the magnitude of the post-1970 IPO underperformance observed in data.
Optimal Portfolio Choice with Parameter Uncertainty
Authors: Kan Raymond , Zhou Guofu
Published: April 2009

In this paper, we analytically derive the expected loss function associated with using sample means and the covariance matrix of returns to estimate the optimal portfolio. Our analytical results show that the standard plug-in approach that replaces the population parameters by their sample estimates can lead to very poor out-of-sample performance. We further show that with parameter uncertainty, holding the sample tangency portfolio and the riskless asset is never optimal. An investor can benefit by holding some other risky portfolios that help reduce the estimation risk. In particular, we show that a portfolio that optimally combines the riskless asset, the sample tangency portfolio, and the sample global minimum-variance portfolio dominates a portfolio with just the riskless asset and the sample tangency portfolio, suggesting that the presence of estimation risk completely alters the theoretical recommendation of a two-fund portfolio.
Information Disclosure and Market Quality: The Effect of SEC Rule 605 on Trading Costs
Authors: Zhao Xin , Chung Kee H.
Published: April 2009

The Securities and Exchange Commission (SEC) adopted Rule 605 (formerly Rule 11Ac1–5) on November 15, 2000. The Rule requires market centers to make monthly public disclosure of execution quality. The Rule is intended to achieve a more competitive and efficient national market system by increasing the visibility of execution quality. The effective and quoted spreads for our study sample of NYSE, AMEX, and NASDAQ stocks declined significantly after implementation of the Rule. The decline cannot be attributed to a secular trend in spreads, concurrent changes in stock attributes, or the effect of decimal pricing. Although the quoted depth of NYSE stocks also declined, overall market quality is higher after implementation of the Rule. Based on these results, we conclude that the SEC's goal to improve execution quality through more transparent markets has been achieved.
Portfolio Concentration and the Performance of Individual Investors
Authors: Ivković Zoran , Sialm Clemens , Weisbenner Scott
Published: April 2009

This paper tests whether information advantages help explain why some individual investors concentrate their stock portfolios in a few stocks. Stock investments made by households that choose to concentrate their brokerage accounts in a few stocks outperform those made by households with more diversified accounts (especially among those with large portfolios). Excess returns of concentrated relative to diversified portfolios are stronger for stocks not included in the S&P 500 index and local stocks, potentially reflecting concentracted investors' successful exploitation of information asymmetries. Controlling for households' average investment abilities, their trades and holdings perform better when their portfolios include fewer stocks.
New Evidence of Asymmetric Dependence Structures in International Equity Markets
Authors: Okimoto Tatsuyoshi
Published: April 2009

A number of recent studies finds two asymmetries in dependence structures in international equity markets; specifically, dependence tends to be high in both highly volatile markets and in bear markets. In this paper, a further investigation of asymmetric dependence structures in international equity markets is performed by using the Markov switching model and copula theory. Combining these two theories enables me to model dependence structures with sufficient flexibility. Using this flexible framework, I indeed find that there are two distinct regimes in the U. S.-U. K. market. I also show that for the U. S.-U. K. market the bear regime is better described by an asymmetric copula with lower tail dependence with clear rejection of the Markov switching multivariate normal model. In addition, I show that ignorance of this further asymmetry in bear markets is very costly for risk management. Lastly, I conduct a similar analysis for other G7 countries, where I find other cases in which the use of a Markov switching multivariate normal model would be inappropriate.
Managerial Traits and Capital Structure Decisions
Authors: Hackbarth Dirk
Published: April 2009

This article incorporates well-documented managerial traits into a tradeoff model of capital structure to study their impact on corporate financial policy and firm value. Optimistic and/or overconfident managers choose higher debt levels and issue new debt more often but need not follow a pecking order. The model also surprisingly uncovers that these managerial traits can play a positive role. Biased managers' higher debt levels restrain them from diverting funds, which increases firm value by reducing this manager-shareholder conflict. Although higher debt levels delay investment, mildly biased managers' investment decisions can increase firm value by reducing this bondholder-shareholder conflict.
Style Investing and Institutional Investors
Authors: Froot Kenneth , Teo Melvyn
Published: April 2009

This Paper explores the importance and price implications of style investing by institutional investors in the stock market. To analyze styles, we assign stocks to deciles or segments across three style dimensions: size, value/growth, and sector. we find strong evidence that institutional investors reallocate and sector. We find strong evidence that institutional investors reallocate across style groupings more intensively than across random stock groupings. In addition, we show that own segment style inflows and refurns positively forecast future stock returns, which distant segament style inflows and returns forecast negatively. We argue that behavioral theories play a role in explaining these results.
Blockholder Scarcity, Takeovers, and Ownership Structures
Authors: Gorton Gary , Kahl Matthias
Published: April 2009

Agency problems in firms are prevalent because of a scarcity of wealthy principals with corporate governance ability, whom we call “restructuring specialists.” We investigate how this scarce resource, “agency cost-free capital,” is allocated. We show that the restructuring specialists may acquire blocks only in those states of the worls in which they can increase firm value the most, which corresponds to a takeover. Firms with dispersed ownership and firms with a financial intermediary as a blockholder can coexist, although they are otherwise identical. The moderl can explain differences in corporate ownership structures and restructuring mechanisms across economies.
Using Innovative Securities under Asymmetric Information: Why Do Some Firms Pay with Contingent Value Rights?
Authors: Chatterjee Sris , Yan An
Published: April 2009

This paper provides the first theoretical explanation and the first empirical analysis of contingent value rights (CVRs), which have been used as a means of payment in acquisitions, exchange offers, debt restructurings, Chapter 11 reorganizations, and lawsuit settlements. A CVR is a put option committing to pay additional cash or securities to CVR holders, contingent on the issuer's share price falling below a prespecified reference level. In this paper, we develop a model to show that CVRs can help a higher-intrinsic-value firm to reveal its firm type when the firm faces an asymmetric information problem. Our model predicts that i) when CVRs are offered along with cash or stock, the announcement period abnormal stock return is greater than that in stock offers, ii) firms facing more severe asymmetric information problems are more likely to offer CVRs to signal their firm type, and iii) firms that are relatively more cash-constrained are more likely to offer CVRs rather than cash. We test all three predictions using a sample of mergers and acquisitions. Our empirical results are consistent with the predictions of the model.
Management of the narrow nose
Authors: Wallace H , Sood S , Rafferty A
Published: April 2009

Nasal obstruction is one of the most common complaints in the otolaryngology clinic. It can be a complex problem and may be multifactorial. Nasal valve dysfunction can be a cause of nasal obstruction, particularly in patients who have undergone previous reduction rhinoplasty. The exact site of the nasal valve is contentious and is frequently subdivided into the internal and external nasal valves. Accurate assessment is crucial for correct diagnosis and management planning. Various surgical and non-surgical techniques for addressing the problem of nasal valve collapse have been described in the literature. The choice of technique will depend on the causative pathology, availability of graft material, surgical experience and patient preference.
Laryngomalacia in a 12-year-old child after laryngeal mask use
Authors: Sproson E L , Madden G J , Turner M W A
Published: April 2009

Objective:

We present an unusual case of a 12-year-old child with state-dependent laryngomalacia presenting after anaesthesia with a laryngeal mask airway.

Method:

Current literature on state-dependent laryngomalacia and injury following laryngeal mask use is reviewed.

Results:

A child who had previously suffered with laryngomalacia as an infant presented with disturbed breathing at night and during exercise. After anaesthesia using a laryngeal mask airway, these symptoms became more pronounced. Microlaryngoscopy revealed laryngomalacic type movement of the larynx.

Conclusion:

Our case seems to support a more complex, multifactorial aetiology for laryngomalacia, including both the neurological control of the larynx as well as its structure.
Facial nerve decompression via middle fossa approach for hyperostosis cranialis interna: a feasible therapeutic approach
Authors: Waterval J J , Stokroos R J , De Bondt R B J , Manni J J
Published: April 2009

Hyperostosis cranialis interna is an autosomal dominant disorder characterised by endosteal hyperostosis and osteosclerosis of the skull base and calvaria, leading to compression and dysfunction of cranial nerves I, II, VII and VIII.

Case report:

We report the use of bilateral surgical decompression of the internal auditory canals to treat hyperostosis cranialis interna in an eight-year-old girl presenting with bilateral facial palsy due to hyperostosis cranialis interna.

Intervention and outcome:

Using a middle fossa craniotomy approach, both internal auditory canals were unroofed and cranial nerves VII and VIII were decompressed, with a one-year interval between sides. The mimic function recovered. One year post-operatively, the right and left facial sides had been restored to House–Brackmann grades I and II, respectively.

Conclusion:

This is the first report of the use of surgical decompression of the internal auditory canal in a case of hyperostosis cranialis interna. Surgical decompression of the internal auditory canal is recommended therapeutically, but may also be performed prophylactically in younger patients with hyperostosis cranialis interna.
Crafting an International Legal Regime for Worker Rights: Assessing the Literature since the 1999 Seattle WTO Protests
Authors: French John D. , Wintersteen Kristin
Published: April 2009

Since the fall of the Soviet Union in 1991, critical attention has increasingly focused on the remaining world system, capitalist in nature and anchored in the World Trade Organization (WTO), founded in 1994 as the successor to the 1948 General Agreement on Tariffs and Trade (GATT). As the 1990s progressed, a smattering of exciting new intellectual work began to appear on the social and environmental impacts of the international trade and investment regime, especially given its apparently negative impact on many developing countries and the world's working people. “The distinction somewhat comfortably maintained by ‘trade hands’ who managed the post-World War II international economy—that trade is strictly a commercial function with no immediate connection to social concerns—has evaporated under the pressure of political and social forces generated by the globalization of the economy.”
Function-based failure propagation for conceptual design
Authors: Krus Daniel , Grantham Lough Katie
Published: April 2009

When designing a product, the earlier the potential risks can be identified, the more costs can be saved, as it is easier to modify a design in its early stages. Several methods exist to analyze the risk in a system, but all require a mature design. However, by applying the concept of “common interfaces” to a functional model and utilizing a historical knowledge base, it is possible to analyze chains of failures during the conceptual phase of product design. This paper presents a method based on these common interfaces to be used in conjunction with other methods such as risk in early design to allow a more complete risk analysis during the conceptual design phase. Finally, application of this method is demonstrated in a design setting by applying it to a thermal control subsystem.
The effects of brain-derived neurotrophic factor and metformin on in vitro developmental competence of bovine oocytes
Authors: Hong So Gun , Jang Goo , Oh Hyun Ju , Koo Ok Jae , Park Jung Eun , Park Hee Jung , Kang Sung Keun , Lee Byeong Chun
Published: April 2009

Brain-derived neurotrophic factor (BDNF) signalling via tyrosine kinase B receptors may play an important role in ovarian development and function. It has been reported that metformin elevates the activity of Tyrosine kinase receptors and may amplify BDNF signalling. The objective of this study was to investigate the effect of BDNF during in vitro maturation (IVM) and/or in vitro culture (IVC) (Experiment 1), and to evaluate the collaborative effect of BDNF and metformin treatment on the developmental competence of bovine in vitro fertilized (IVF) embryos (Experiment 2). In Experiment 1, BDNF, which was added to our previously established IVM systems, significantly increased the proportions of MII oocytes at both 10 ng/ml (86.7%) and 100 ng/ml (85.4%) compared with the control (64.0%). However, there was no statistically significant difference in blastocyst development between the control or BDNF-supplemented groups. In Experiment 2, in order to investigate the effect of BDNF (10 ng/ml) and/or metformin (10−5 M) per se, TCM-199 without serum and hormones was used as the control IVM medium. The BDNF (48.3%) and BDNF plus metformin (56.5%) significantly enhanced the proportions of MII oocytes compared with the control (34.4%). Although, BDNF or metformin alone had no effect in embryo development, BDNF plus metformin significantly improved early embryo development to the 8–16-cell stage compared with the control (16.5 vs. 5.5%). In conclusion, the combination of BDNF and metformin may have a collaborative effect during the IVM period. These results could further contribute to the establishment of a more efficient bovine in vitro embryo production system.
Patterns of food insecurity and participation in food assistance programmes over time in the elderly
Authors: Kim Kirang , Frongillo Edward A
Published: April 2009

Objective

The present study aimed to understand the relationship between need and help-seeking behaviour in older adults by examining the patterns of food insecurity and participation in food assistance programmes (FAP), i.e. the Food Stamp Program and home-delivered meals.

Design

Data from two longitudinal studies were used. The studies were designed to obtain nationally representative information on health, insurance coverage, financial status, family support systems, labour market status and retirement planning, every two years: the Health and Retirement Study (HRS, 1996–2002) and Asset and Health Dynamics Among the Oldest Old (AHEAD, 1995–2002).

Setting

USA.

Subjects

There were 7623 participants for HRS and 3378 for AHEAD.

Results

The older adults appeared to have persistent patterns between food insecurity and participation in FAP, especially in the Food Stamp Program. More persistently food-insecure older adults had higher participation in FAP (P < 0·001). Food-insecure older adults at one time were more likely to shift from non-participation to participation in FAP the next time than food-secure older adults (P < 0·001). Regardless of previous food insecurity status, previous participants in FAP were more likely to participate subsequently.

Conclusions

The relationship between need and help-seeking behaviour in older adults was found to follow a persistent positive pattern, determined by looking at the patterns of food insecurity and participation in FAP. Although food insecurity as a need is a good predictor of participation in FAP, it is not enough to fully predict participation in FAP. Help-seeking behaviour (i.e. previous programme participation) is also important in predicting participation in FAP.
An Unlikely Synergy: Lou Harrison and Arnold Schoenberg
Authors: NEFF SEVERINE
Published: April 2009

This essay addresses the unlikely but profound synergy between Arnold Schoenberg and Lou Harrison. Despite their personal rapport and mutual interests in visual art, they held antithetical beliefs about the nature of musical composition. Schoenberg maintained that a composition was the presentation of a metaphysical “Idea.” Harrison saw composition as the process of systematically gathering and assembling resources and techniques.

After studying with Henry Cowell and Schoenberg, Harrison displayed a fascination with musical resources that led him to compose twelve-tone works using disparate compositional tools. A 1937 piano piece combines Schoenberg's methods of variation with Cowell's and Seeger's techniques of “dissonation.” The “Conductus” from the 1942 Suite for Piano, a work inspired by Schoenberg'sSuite für Klavier, op. 25, explores all twelve prime forms of the row in light of Cage's square-root form. A nontonal 1944 string quartet ends on a triad like Schoenberg'sOde to Napoleon, op. 41.

In the 1950s Harrison rejected the aims of the total-serialist movement and found his own voice in just intonation instead. By the 1980s all vestiges of twelve-tone technique disappeared from his pieces; however, analogous serial techniques resurfaced in his paintings. Thus Harrison retained deep respect for Schoenberg as a composer, teacher, and friend.
Conjugate ionospheric equivalent currents during bursty bulk flows
Authors: Juusola L. , Nakamura R. , Amm O. , Kauristie K.
Published: April 2009

Ionospheric equivalent currents related to bursty bulk flows (BBF) during Cluster and the International Monitor for Auroral Geomagnetic Effects (IMAGE) magnetometer network conjunctions between 2001 and 2006 are studied. A geomagnetically southeast–northwest aligned, relatively narrow channel of northwestward equivalent current density with downward field‐aligned current at its northeastward flank and upward field‐aligned current at its southwestward flank is confirmed as the ionospheric signature of BBFs in the majority of cases, i.e., whenever an ionospheric signature is present. Unlike in previous event studies, all conjugate BBFs between 2001 and 2006 are analyzed and during 19 out of 22 BBFs, the channel is observed in the ionosphere. The mean duration of the BBFs observed when the footprint of Cluster is located close to the poleward boundary of the auroral oval is clearly longer (17 min) than the that of the BBFs observed close to the equatorward boundary of the oval (3 min). A superposed epoch analysis of the local IMAGE AE (IE) index reveals a stronger activity level preceding a substorm‐related than a nonsubstorm BBF. After the BBF observation, however, the activity in both cases is on the same level as that preceding the substorm BBF observation. The observation of the substorm BBF coincides with a substorm‐like disturbance of the IE, while the observation of the nonsubstorm BBF coincides with a step‐like increase of the IE.
Role of entropy in magnetotail dynamics
Authors: Birn J. , Hesse M. , Schindler K. , Zaharia S.
Published: April 2009

The role of entropy conservation and loss in magnetotail dynamics, particularly in relation to substorm phases, is discussed on the basis of MHD theory and simulations, using comparisons with particle‐in‐cell (PIC) simulations for validation. Entropy conservation appears to be a crucial element leading to the formation of thin embedded current sheets in the late substorm growth phase and the potential loss of equilibrium. Entropy conservation also governs the accessibility of final states of evolution and the amount of energy that may be released. Entropy loss (in the form of plasmoids) is essential in the earthward transport of flux tubes (bubbles, bursty bulk flows). Entropy loss also changes the tail stability properties and may render ballooning modes unstable and thus contribute to cross‐tail variability. We illustrate these effects through results from theory and simulations.
Assumptions in the evaluation of lava effusion rates from heat radiation
Authors: Dragoni Michele , Tallarico Andrea
Published: April 2009

The availability of high‐resolution thermal imagery of active lava flows has stimulated the use of radiance maps for the evaluation of lava effusion rates. This is made possible by simple formulae relating the lava flow rate to the energy radiated per unit time from the planimetric surface of the flow. Such formulae are based on a specific flow model and, consequently, their validity is subject to the model assumptions. An analysis of these assumptions reveals that the current use of the formulae is not consistent with the model. The reason why they provide reasonable, although very rough, values for effusion rates appears to be that the actual radiated energy is controlled by a feature (the nonuniform temperature of flow surface) which is not accounted for by the model and which counterbalances the effect of inconsistent use of the formulae.
Adherens junction domains are split by asymmetric division of embryonic neural stem cells
Authors: Marthiens Véronique , ffrench‐Constant Charles
Published: April 2009

Investigating the mechanisms controlling the asymmetric division of neocortical progenitors that generate neurones in the mammalian brain is crucial for understanding the abnormalities of cortical development. Partitioning of fate determinants is a key instructive step and components of the apical junctional complex (adherens junctions), including the polarity proteins PAR3 and aPKC as well as adhesion molecules such as N‐cadherin, have been proposed to be candidate determinants. In this study, however, we found no correlation between the partitioning of N‐cadherin and fate determination. Rather, we show that adherens junctions comprise three membrane domains, and that during asymmetrical division these are split such that both daughters retain the adhesive proteins that control cell position, but only one daughter inherits the polarity proteins along with the apical membrane. This provides a molecular explanation as to how both daughters remain anchored to the ventricular surface after mitosis, while adopting different fates.
Eukaryotic initiation factor 6 mediates a continuum between 60S ribosome biogenesis and translation
Authors: Miluzio Annarita , Beugnet Anne , Volta Viviana , Biffo Stefano
Published: April 2009

Eukaryotic ribosome biogenesis and translation are linked processes that limit the rate of cell growth. Although ribosome biogenesis and translation are mainly controlled by distinct factors, eukaryotic initiation factor 6 (eIF6) has been found to regulate both processes. eIF6 is a necessary protein with a unique anti‐association activity, which prevents the interaction of 40S ribosomal subunits with 60S subunits through its binding to 60S ribosomes. In the nucleolus, eIF6 is a component of the pre‐ribosomal particles and is required for the biogenesis of 60S subunits, whereas in the cytoplasm it mediates translation downstream from growth factors. The translational activity of eIF6 could be due to its anti‐association properties, which are regulated by post‐translational modifications; whether this anti‐association activity is required for the biogenesis and nuclear export of ribosomes is unknown. eIF6 is necessary for tissue‐specific growth and oncogene‐driven transformation, and could be a new rate‐limiting step for the initiation of translation.
Improvement of the magnetic configuration in the reversed field pinch through successive bifurcations
Authors: Lorenzini R. , Agostini M. , Alfier A. , Antoni V. , Apolloni L. , Auriemma F. , Barana O. , Baruzzo M. , Bettini P. , Bonfiglio D. , Bolzonella T. , Bonomo F. , Brombin M. , Buffa A. , Canton A. , Cappello S. , Carraro L. , Cavazzana R. , Chitarin G. , Dal Bello S. , De Lorenzi A. , De Masi G. , Escande D. F. , Fassina A. , Franz P. , Gaio E. , Gazza E. , Giudicotti L. , Gnesotto F. , Gobbin M. , Grando L. , Guo S. C. , Innocente P. , Luchetta A. , Manduchi G. , Marchiori G. , Marcuzzi D. , Marrelli L. , Martin P. , Martini S. , Martines E. , Milani F. , Moresco M. , Novello L. , Ortolani S. , Paccagnella R. , Pasqualotto R. , Peruzzo S. , Piovan R. , Piovesan P. , Piron L. , Pizzimenti A. , Pomaro N. , Predebon I. , Puiatti M. E. , Rostagni G. , Sattin F. , Scarin P. , Serianni G. , Sonato P. , Spada E. , Soppelsa A. , Spagnolo S. , Spizzo G. , Spolaore M. , Taliercio C. , Terranova D. , Toigo V. , Valisa M. , Veltri P. , Vianello N. , Zaccaria P. , Zaniol B. , Zanotto L. , Zilli E. , Zuin M.
Published: April 2009

The reversed field pinch (RFP) is a magnetic configuration alternative to the tokamak that can be considered for a second generation of reactors. In this paper new remarkable results obtained in the RFP experiment RFX-mod are presented, showing that an internal transport barrier delimitates a large fraction of the plasma volume in a RFP when the current is raised to ∼1.5 MA. The formation of this transport barrier is related to a profound, spontaneous modification of the magnetic topology. Due to the occurrence of a saddle node bifurcation the plasma enters in the single helical axis state, which is theoretically known to be more resilient to chaos. This bifurcation is driven by the amplitude of the helical perturbation which dominates the mode spectrum.
Strain relaxation in AlGaN multilayer structures by inclined dislocations
Authors: Follstaedt D. M. , Lee S. R. , Allerman A. A. , Floro J. A.
Published: April 2009

To examine further the strain relaxation produced by inclined threading dislocations in AlGaN, a heterostructure with three AlGaN layers having successively increasing Ga contents and compressive strains was grown on an AlN template layer by metalorganic vapor-phase epitaxy. The strain state of the layers was determined by x-ray diffraction (XRD) and the dislocation microstructure was characterized with transmission electron microscopy (TEM). As the GaN mole fraction of the heterostructure increased from 0.15 to 0.48, the increased epitaxial strain produced inclined dislocations with successively greater bend angles. Using the observed bend angles, which ranged from 6.7° to 17.8°, the measured strain relaxation within each layer was modeled and found to be accounted for by threading-dislocation densities of 6–7×109/cm2, in reasonable agreement with densities determined by TEM and XRD. In addition to the influence of lattice-mismatch strain on the average bend angle, we found evidence that local strain inhomogeneities due to neighboring dislocations influence the specific bend angles of individual dislocations. This interaction with local strain fields may contribute to the large spread in the bend angles observed within each layer. A detailed TEM examination found that the initial bending of threading dislocations away from vertical often occurs at positions within <15 nm of the AlGaN/AlN heterointerface. Under the assumption that dislocation climb mediated by bulk-defect diffusion is effectively suppressed at the growth temperature, this result implies that inclination is established by processes occurring at the dynamic growth surface. We describe a mechanism where dislocation bending occurs by means of dislocation-line jogs created when surface steps overgrow vacancies that attach to threading-dislocation cores at their intersection with the growth surface.
Front surface thermal property measurements of air plasma spray coatings
Authors: Bennett Ted , Kakuda Tyler , Kulkarni Anand
Published: April 2009

A front-surface measurement for determining the thermal properties of thermal barrier coatings has been applied to air plasma spray coatings. The measurement is used to determine all independent thermal properties of the coating simultaneously. Furthermore, with minimal requirements placed on the sample and zero sample preparation, measurements can be made under previously impossible conditions, such as on serviceable engine parts. Previous application of this technique was limited to relatively thin coatings, where a one-dimensional heat transfer model is applied. In this paper, the influence of heat spreading on the measurement of thicker coatings is investigated with the development of a two-dimensional heat transfer model.
Nonmalleable encryption of quantum information
Authors: Ambainis Andris , Bouda Jan , Winter Andreas
Published: April 2009

We introduce the notion of nonmalleability of a quantum state encryption scheme (in dimension d): in addition to the requirement that an adversary cannot learn information about the state, here we demand that no controlled modification of the encrypted state can be effected. We show that such a scheme is equivalent to a unitary 2-design [Dankert, et al., e-print arXiv:quant-ph/0606161], as opposed to normal encryption which is a unitary 1-design. Our other main results include a new proof of the lower bound of (d2−1)2+1 on the number of unitaries in a 2-design [Gross, et al., J. Math. Phys. 48, 052104 (2007)], which lends itself to a generalization to approximate 2-design. Furthermore, while in prime power dimension there is a unitary 2-design with ≤d5 elements, we show that there are always approximate 2-designs with O(ϵ−2d4 log d) elements.
Energy transfer between Eu2+ and Mn2+ in long-afterglow phosphor CaAl2O4:Eu2+, Nd3+, and Mn2+
Authors: Xu Xuhui , Wang Yuhua , Li Yanqin , Gong Yu
Published: April 2009

Long-afterglow phosphor CaAl2O4:Eu2+, Nd3+, and Mn2+ were prepared by the solid-state synthesis method. The CaAl2O4:Eu2+, Nd3+, and Mn2+ phosphors show two emission bands peaking at around 440 and 545 nm, originating from the allowed f-d transition of Eu2+ and the forbidden T41-A61 transition of Mn2+, respectively, under ultraviolet excitation at 340 nm. Spectroscopy and afterglow decay time measurements demonstrate that energy transfer from Eu2+ to Mn2+. The different colors between photoluminescence and afterglow was analyzed and observed based on energy transfer. Moreover, effects of Mn2+ doping on the afterglow properties of CaAl2O4:Eu2+, Nd3+ are explored and explained by thermoluminescence technique.
Polaron dynamics in lithium niobate upon femtosecond pulse irradiation: Influence of magnesium doping and stoichiometry control
Authors: Sasamoto Satoru , Hirohashi Junji , Ashihara Satoshi
Published: April 2009

The formation and relaxation dynamics of electron polarons in lithium niobate crystals were investigated by measuring transient absorption induced by blue femtosecond pulses. Anisotropy in the absorption change distinguished between small free polarons and small bound polarons, revealing that the dynamics were influenced by MgO doping and stoichiometry control. In crystals doped with MgO at concentrations above threshold, small free polarons were generated within 100 fs and decayed after tens of nanoseconds. In the presence of antisite defects, sequential formation of polaronic states occurred: electrons initially trapped as small free polarons became trapped as small bound polarons on picosecond time scale. The results are relevant for nonlinear optical applications of pulsed or high-power lasers.