Showing papers by "Williams College published in 2001"

Remote State Preparation

Abstract: Quantum teleportation uses prior entanglement and forward classical communication to transmit one instance of an unknown quantum state. Remote state preparation (RSP) has the same goal, but the sender knows classically what state is to be transmitted. We show that the asymptotic classical communication cost of RSP is one bit per qubit--half that of teleportation--and even less when transmitting part of a known entangled state. We explore the tradeoff between entanglement and classical communication required for RSP, and discuss RSP capacities of general quantum channels.

The Regulation and Supervision of Banks Around the World: A New Database

Abstract: This new and comprehensive database on the regulation and supervision of banks in 107 countries should better inform advice about bank regulation and supervision and lower the marginal cost of empirical research.International consultants on bank regulation and supervision for developing countries often base their advice on how their home country does things, for lack of information on practice in other countries. Recommendations for reform have tended to be shaped by bias rather than facts.To better inform advice about bank regulation and supervision and to lower the marginal cost of empirical research, Barth, Caprio, and Levine present and discuss a new and comprehensive database on the regulation and supervision of banks in 107 countries. The data, based on surveys sent to national bank regulatory and supervisory authorities, are now available to researchers and policymakers around the world.The data cover such aspects of banking as entry requirements, ownership restrictions, capital requirements, activity restrictions, external auditing requirements, characteristics of deposit insurance schemes, loan classification and provisioning requirements, accounting and disclosure requirements, troubled bank resolution actions, and (uniquely) the quality of supervisory personnel and their actions.The database permits users to learn how banks are currently regulated and supervised, and about bank structures and deposit insurance schemes, for a broad cross-section of countries.In addition to describing the data, Barth, Caprio, and Levine show how variables may be grouped and aggregated. They also show some simple correlations among selected variables.In a companion paper ("Bank Regulation and Supervision: What Works Best") studying the relationship between differences in bank regulation and supervision and bank performance and stability, they conclude that:- Countries with policies that promote private monitoring of banks have better bank performance and more stability. Countries with more generous deposit insurance schemes tend to have poorer bank performance and more bank fragility.- Diversification of income streams and loan portfolios - by not restricting bank activities - also tends to improve performance and stability. (This works best when an active securities market exists.) Countries in which banks are encouraged to diversify their portfolios domestically and internationally suffer fewer crises.This paper - a product of Finance, Development Research Group, and the Financial Sector Strategy and Policy Department - is part of a larger effort in the Bank to compile data on financial regulation and supervision and the advise countries on what works best. The study was funded by the Bank's Research Support Budget under the research project "Bank Regulation and Supervision: What Works and What Does Not."

Entanglement of formation and concurrence

Abstract: Entanglement of formation is one of three widely studied measures of entanglement of a general bipartite system This paper reviews our current understanding of entanglement of formation and the related concept of concurrence, including discussions of additivity, the problem of finding explicit formulas, and connections between concurrence and other properties of bipartite states

Bank Regulation and Supervision: What Works Best?

Abstract: The regulatory and supervisory practices most effective in promoting good performance and stability in the banking sector are those that force accurate information disclosure, empower private sector monitoring of banks, and foster incentives for private agents to exert corporate control. Barth, Caprio, and Levine draw on their new database on bank regulation and supervision in 107 countries to assess different governmental approaches to bank regulation and supervision and evaluate the efficacy of different regulatory and supervisory policies. First, the authors assess two broad and competing theories of government regulation: the helping-hand approach, according to which governments regulate to correct market failures, and the grabbing-hand approach, according to which governments regulate to support political constituencies. Second, they assess the effect of an extensive array of regulatory and supervisory policies on the development and fragility of the banking sector. These policies include the following: - Regulations on bank activities and the mixing of banking and commerce. - Regulations on entry by domestic and foreign banks. - Regulations on capital adequacy. - Design features of deposit insurance systems. - Supervisory power, independence, and resources; stringency of loan classification; provisioning standards; diversification guidelines; and powers to take prompt corrective action. - Regulations governing information disclosure and fostering private sector monitoring of banks. - Government ownership of banks. The results raise a cautionary flag with regard to reform strategies that place excessive reliance on a country's adherence to an extensive checklist of regulatory and supervisory practices that involve direct government oversight of and restrictions on banks. The findings, which are much more consistent with the grabbing-hand view of regulation than with the helping-hand view, suggest that the regulatory and supervisory practices most effective in promoting good performance and stability in the banking sector are those that force accurate information disclosure, empower private sector monitoring of banks, and foster incentives for private agents to exert corporate control. This paper - a joint product of Finance, Development Research Group, and the Financial Sector Strategy and Policy Department - is part of a larger effort in the Bank to analyze the effect of financial sector regulation on development. The authors may be contacted at jbarth@business.auburn.edu, gcaprio@worldbank.org, or rlevine@csom.umn.edu.

Overland dispersal of aquatic invasive species: a risk assessment of transient recreational boating.

Abstract: Predictions of the geographic spread of introduced species are often limited by a lack of data on their mechanisms of dispersal. We interviewed boaters and inspected boating equipment at public boat launches on Lake St. Clair (Michigan, USA) to assess the potential for the zebra mussel, an invasive bivalve, to be dispersed overland to inland waters by transient recreational boating activities. Several mechanisms associated with recreational boating were found to be capable of transporting either larval or adult life stages. Larvae were found in all forms of water carried by boats (i.e., in live wells, bilges, bait buckets, and engines) but were estimated to be 40–100× more abundant in live wells than other locations. Dilution in receiving waters should, however, greatly reduce the risk of establishing new populations by the introduction of larvae. Contrary to common belief, mussel dispersal from these boat launches did not occur by direct attachment to transient boats. Rather, adult and juvenile mussels were transported primarily on macrophytes entangled on boat trailers and, less frequently, on anchors (5.3% and 0.9% of departing boats, respectively). Combining these data with estimates of survival in air and reported boater destinations, we predict that a maximum of 0.12% of the trailered boats departing these access sites delivered live adult mussels to inland waters solely by transport on entangled macrophytes. While this is a small probability, high levels of vector activity resulted in a prediction of a total of 170 dispersal events to inland waters within the summer season from the primary boat launch studied. Many other potential vectors remain to be assessed, but the dispersal of zebra mussels by trailered boats, particularly by “piggybacking” on macrophytes entangled on the trailers, must be controlled in order to limit further range expansion of the zebra mussel within North America.

Community based targeting mechanisms for social safety nets

Abstract: This paper interprets case studies, and theory on community involvement in beneficiary selection, and benefit delivery for social safety nets Several considerations should be carefully balanced in assessing the advantages of using community groups as targeting agents First, benefits from utilizing local information, and social capital may be eroded by costly rent-seeking Second, the potential improvement in targeting criteria from incorporating local notions of deprivation, must be tempered by the possibility of program capture by local elites, and by the possibility that local preferences are not pro-poor Third, performance may be undermined by unforeseen strategic targeting by local communities in response to national funding, and evaluation criteria, or by declines in political support

On the "general acceptance" of eyewitness testimony research. A new survey of the experts.

Abstract: In light of recent advances, this study updated a prior survey of eyewitness experts (S. M. Kassin, P. C. Ellsworth, & V. L. Smith, 1989). Sixty-four psychologists were asked about their courtroom experiences and opinions on 30 eyewitness phenomena. By an agreement rate of at least 80%, there was a strong consensus that the following phenomena are sufficiently reliable to present in court: the wording of questions, lineup instructions, confidence malleability, mug-shot-induced bias, postevent information, child witness suggestibility, attitudes and expectations, hypnotic suggestibility, alcoholic intoxication, the crossrace bias, weapon focus, the accuracy-confidence correlation, the forgetting curve, exposure time, presentation format, and unconscious transference. Results also indicate that these experts set high standards before agreeing to testify. Despite limitations, these results should help to shape expert testimony so that it more accurately represents opinions in the scientific community.

The Control of Biological Invasions in the World's Oceans

Abstract: The introduction of alien, or nonindigenous, animals and plants has been identified by scientists and policy makers as a major threat to biodiversity in marine ecosystems. Although government agencies have struggled to control alien species on land and freshwater for decades with mixed success, the control of alien marine species is in its infancy. Prevention of introduction and establishment must be the first priority, but many populations of alien marine species are already well established worldwide. National and interna- tional policies leave loopholes for additional invasions to occur and provide only general guidance on how to control alien species once they are established. To address this issue, a multinational group of 25 scientists and attorneys convened in 1998 to examine options for controlling established populations of alien marine species. The discussions resulted in a framework for control of alien marine species to provide decision-mak- ing guidance to policymakers, managers, scientists, and other stakeholders. The framework consists of seven basic steps: (1) establish the nature and magnitude of the problem, (2) set objectives, (3) consider the full range of alternatives, (4) determine risk, (5) reduce risk, (6) assess benefits versus risks, and (7) monitor the situation. This framework can provide guidance for control efforts under the existing patchwork of national laws and can help provide a foundation for international cooperation.

Is clinical depression distinct from subthreshold depressive symptoms? A review of the continuity issue in depression research.

Abstract: Resolving whether subthreshold depressive symptoms exist on a continuum with unipolar clinical depression is important for progress on both theoretical and applied issues. To date, most studies have found that individuals with subthreshold depressive symptoms resemble cases of major depressive disorder along many important dimensions (e.g., in terms of patterns of functional impairment, psychiatric and physical comorbidity, familiality, sleeping EEG, and risk of future major depression). However, such manifest similarities do not rule out the possibility of a latent qualitative difference between subthreshold and diagnosable depression. Formal taxonomic analyses, intended to resolve the possibility of a latent qualitative distinction, have so far yielded contradictory findings. Several large-sample latent class analyses (LCA) have identified latent clinical and nonclinical classes of unipolar depression, but LCA is vulnerable to identification of spurious classes. Paul Meehl's taxometric methods provide a potentially conservative alternative way to identify latent classes. The one comprehensive taxometric analysis reported to date suggests that self-report depression symptoms occur along a latent continuum but exclusive reliance on self-report depression measures and incomplete information regarding sample base rates of depression makes it difficult to draw strong inferences from that report. We conclude that although most of the evidence at this time appears to favor both a manifest and latent continuum of unipolar depression symptomatology, several important issues remain unresolved. Complete resolution of the continuity question would be speeded by the application of both taxometric techniques and LCA to a single large sample with a known base rate of lifetime diagnosed depressives.

Overcoming Math Anxiety.

Abstract: Math anxiety can greatly affect a child's success throughout their education and their adult life. Since math is connected to so many professional and personal practices, it is important that we as educators and parents help children to overcome their math anxiety so they can learn the math skills that they need to succeed. Math anxiety is real and it can happen to anyone at any age regardless of their mathematical ability.

The Causes and Consequences of Corruption

Abstract: In recent years, economists have come to recognize that corruption is not just an aberration or a nuisance; it is a systemic feature of many economies, which constitutes a significant impediment to economic development. The authors present an overview of the literature on the causes and consequences of corruption and briefly comment on some policy issues, drawing on recent research, including their own.

Do others judge us as harshly as we think? Overestimating the impact of our failures, shortcomings, and mishaps.

Abstract: When people suffer an embarrassing blunder, social mishap, or public failure, they often feel that their image has been severely tarnished in the eyes of others. Four studies demonstrate that these fears are commonly exaggerated. Actors who imagined committing one of several social blunders (Study 1), who experienced a public intellectual failure (Studies 2 and 3), or who were described in an embarrassing way (Study 4) anticipated being judged more harshly by others than they actually were. These exaggerated fears were produced, in part, by the actors' tendency to be inordinately focused on their misfortunes and by their resulting failure to consider the wider range of situational factors that tend to moderate onlookers' impressions. Discussion focuses on additional mechanisms that may contribute to overly pessimistic expectations as well as the role of such expectations in producing unnecessary social anxiety.

Making choices in anticipation of similar future choices can increase self-control.

Abstract: Two experiments tested the efficacy of linking a current choice with similar future choices as a means of increasing self-control. Participants were offered choices between smaller and sooner vs. larger and later amounts of money (Experiment 1, n = 60) or food (Experiment 2, n = 34). After a small-large pair for which the participant preferred the smaller reward was found, a choice between the same pair was offered as the 1st of 5 such choices to be offered over a period of weeks. The majority of participants in both experiments who chose between all 5 smaller and all 5 larger rewards chose the larger rewards. One third of participants in Experiment 1 who could choose independently on each pair in the series reversed their previous preference and chose the larger reward in the context of the series. These results suggest that self-control can be enhanced by viewing one's current choice as predictive of future choices.

Choreography of song, dance and beak movements in the zebra finch (Taeniopygia guttata)

Abstract: SUMMARY As do many songbirds, zebra finches sing their learned songs while performing a courtship display that includes movements of the body, head and beak. The coordination of these display components was assessed by analyzing video recordings of courting males. All birds changed beak aperture frequently within a single song, and each individual’s pattern of beak movements was consistent from song to song. Birds that copied their father’s songs reproduced many of the changes in beak aperture associated with particular syllables. The acoustic consequences of opening the beak were increases in amplitude and peak frequency, but not in fundamental frequency, of song syllables. The change in peak frequency is consistent with the hypothesis that an open beak results in a shortened vocal tract and thus a higher resonance frequency. Dance movements (hops and changes in body or head position) were less frequent, and the distribution of dance movements within the song was not as strongly patterned as were changes in beak aperture, nor were the peaks in the distribution as strongly marked. However, the correlation between the positioning of dance movements within fathers’ and sons’ songs was striking, suggesting that the choreography of dance patterns is transmitted from tutor to pupil together with the song. A QuickTime movie of a courtship display used in this study can be found at: http://www.williams.edu/Biology/ZFinch/zfdance.html.

Pleistocene incision rates in the western United States calibrated using Lava Creek B tephra

Abstract: The Lava Creek B ash bed, erupted from the Yellowstone caldera ca. 0.64 Ma, provides a datum for measuring long-term fluvial incision west of the Mississippi River. The ash is widely preserved due to its substantial volume, broad initial dispersal, and the aggrading environment into which the ash fell. Drainages incised soon after Lava Creek B deposition, isolating the ash from fluvial erosion and preserving it in fill terraces. Calculated rates of incision since ca. 0.60 Ma range from ≤2 to ∼30 cm k.y. −1 . Rates are high in most areas near the Rocky Mountains and downstream along rivers draining mountainous terrain, and are lowest east of the High Plains and along the Snake River. Incision rates along many rivers decrease downstream. Rates of downcutting increased in the late Pleistocene along several major rivers, indicating that climate change altered sediment budgets. Regional and temporal data suggest that fluvial incision records increased middle and late Pleistocene runoff from the southern Rocky Mountains, rather than epeirogenic uplift, but regional rock uplift cannot be excluded as a significant factor.

Beyond Bipolar: A Three-Dimensional Assessment of Monetary Frameworks

Abstract: Recently, great attention has been focused on the impact of exchange rate regimes, just as previous empirical research examined central bank autonomy and announced targets for domestic monetary policy. To date, however, these three elements of monetary frameworks have been assessed in isolation from one another, and all have been viewed in terms of a unidimensional spectrum of fixity versus flexibility. Using a newly-constructed dataset, this paper jointly analyzes and compares all three elements' effects on inflation and exchange rate behavior. The results show that each of the three elements has independent and distinct effects on nominal outcomes. Key findings include: (1) although hard pegs do tend to reduce inflation and attenuate exchange rate fluctuations within some range, they are clearly characterized by large devaluations; (2) central bank autonomy is associated with a more stable exchange rate and lower inflation; and (3) explicit inflation targeting reduces both inflation and its persistence, consistent with the view that inflation targeting increases flexibility through transparency. These results raise the possibility that a combination of central bank autonomy, inflation targeting, and a free float might offer the same benefits as any intermediate exchange rate regime on its own, without the proclivity to occasional large depreciations.

Maintaining one's self-image vis-à-vis others: The role of self-affirmation in the social evaluation of the self.

Abstract: Three studies examined how people maintain their self-images when they face threat to interpersonal aspects of the self. In Studies 1 and 2, we found evidence that low self-esteem people lower their estimates of their performance when they expect immediate feedback in order to protect themselves from the interpersonal threat inherent in such feedback, and that self-affirmation reduces this tendency among low self-esteem people. In Study 3, we found that when people are self-affirmed they are more likely to engage in upward social comparisons and less likely to engage in downward social comparisons. Together these findings suggest that people can cope with threats to interpersonal aspects of the self by affirming other important aspects of the self.

Sulfur, Chlorine, and Argon in Planetary Nebulae. I. Observations and Abundances in a Northern Sample

Abstract: This paper is the first of a series specifically studying the abundances of sulfur, chlorine, and argon in type II planetary nebulae (PNe) in the Galactic disk. Ratios of S/O, Cl/O, and Ar/O constitute important tests of differential nucleosynthesis of these elements and serve as strict constraints on massive star yield predictions. We present new ground-based optical spectra extending from 3600-9600 A for a sample of 19 type II northern PNe. This range includes the strong near-infrared lines of [S III] λλ9069,9532, which allows us to test extensively their effectiveness as sulfur abundance indicators. We also introduce a new, model-tested ionization correction factor for sulfur. For the present sample, we find average values of S/O = 1.2 × 10-2 ± 0.71 × 10-2, Cl/O = 3.3 × 10-4 ± 1.6 × 10-4, and Ar/O = 5.0 × 10-3 ± 1.9 × 10-3.

Sulfur, Chlorine, & Argon Abundances in Planetary Nebulae. I: Observations and Abundances in a Northern Sample

Abstract: This paper is the first of a series specifically studying the abundances of sulfur, chlorine, and argon in Type II planetary nebulae (PNe) in the Galactic disk. Ratios of S/O, Cl/O, and Ar/O constitute important tests of differential nucleosynthesis of these elements and serve as strict constraints on massive star yield predictions. We present new ground-based optical spectra extending from 3600-9600 Angstroms for a sample of 19 Type II northern PNe. This range includes the strong near infrared lines of [S III] 9069,9532, which allows us to test extensively their effectiveness as sulfur abundance indicators. We also introduce a new, model-tested ionization correction factor for sulfur. For the present sample, we find average values of S/O=1.2E-2(+/- 0.71E-2), Cl/O=3.3E-4(+/- 1.6E-4), and Ar/O=5.0E-3(+/- 1.9E-3).

Proof of the Double Bubble Conjecture

Abstract: We prove that the standard double bubble provides the least-area way to enclose and separate two regions of prescribed volume in \\Bbb R^3.

On the Many Impacts of Inadmissible Testimony: Selective Compliance, Need for Cognition, and the Overcorrection Bias

Abstract: A mock juror study tested three hypotheses: (a) Jurors comply selectively with instructions to disregard inadmissible testimony, (b) this effect is greater among jurors who are high rather than low in the need for cognition (NC), and (c) high-NC decision makers sometimes overcorrect against the perceived biasing agent of inadmissible testimony. Participants read a trial summary in which the admissibility of an incriminating wiretap and the basis for this ruling were manipulated. Consistent with the prediction that jurors would be motivated to reach a “just” verdict, participants disregarded an inadmissible wiretap when it was deemed unreliable but not when it violated due process. This pattern of selective compliance was found only among high-NC jurors. High-NC participants also exhibited signs of bias overcorrection, estimating the probability of the defendant’s guilt to be lower in the inadmissible-unreliable condition than in the no-wiretap control. The theoretical and practical implications of these r...

Rethinking the relevance of race for early christian self-definition

Abstract: The view that early Christians neither defined themselves nor were perceived in terms of race or ethnicity finds support in a broad spectrum of scholarly and popular thought.This article is revised from a lecture delivered in the New Testament and Early Christian Studies Lecture Series at the Harvard Divinity School on November 7, 2000. A fellowship in the Bunting Fellowship Program at the Radcliffe Institute for Advanced Study this year has enabled me to write the book to which this article pertains. Caroline Johnson Hodge, Cathy Silber, Francesca Sawaya, Augusta Rohrbach, Lisa Herschbach, and especially Karen King offered valuable suggestions in the preparation of the piece. In addition, Bernadette Brooten, Francois Bovon, Ellen Aitken, Larry Wills, Yuko Taniguchi, and Adam Marlowe provided useful feedback on the lecture. I want to suggest, however, that ethnicity and race have in fact been central to formulations of early Christian self-definition—in two quite different ways, one historical and the other historiographic. First, ancient ideas about race and ethnicity were valuable for early Christians in their varying attempts to define Christianness; many early Christians defined themselves using ethnic reasoning, that is, by using language that their contemporaries would have understood as racial or ethnic. Second, modern ideas about race and ethnicity, as well as about religion, have also shaped understandings of early Christian self-definition but have led to the opposite conclusion—namely, that Christians, from the very beginning, viewed race as a form of human difference to be transcended or made irrelevant.

bHLH transcription factor MyoD affects myosin heavy chain expression pattern in a muscle-specific fashion

Abstract: A strong correlative pattern between MyoD gene expression and myosin heavy chain IIB (MHC IIB) gene expression exists. To test whether this correlative relationship is causative, MHC gene expression in muscles from MyoD(−/−) mice was analyzed. The MHC IIB gene was not detectable in the MyoD(−/−) diaphragm, whereas the MHC IIB protein made up 10.0 ± 1.7% of the MHC protein pool in the wild-type (WT) mouse diaphragm. Furthermore, the MHC IIA protein was not detectable in the MyoD(−/−) biceps brachii, and the MHC IIB protein was overexpressed in the masseter. To examine whether MyoD is required for the upregulation of the MHC IIB gene within slow muscle after disuse, MyoD(−/−) and WT hindlimb musculature was unweighted. MyoD(−/−) exhibited a diminished response in the upregulation of the MHC IIB mRNA within the soleus muscle as a result of the hindlimb unweighting. Collectively, these data suggest that MyoD plays a role in the MHC profile in a muscle-specific fashion.

Regulation of IL-4 production in mast cells: a paradigm for cell-type-specific gene expression.

Abstract: The role of interleukin (IL)-4 as an important immunomodulatory cytokine is well established. IL-4 exhibits a highly restricted pattern of expression by cells of distinct lineages. The cell types that produce IL-4 are located in anatomically distinct locations (e.g. circulating T cells vs. fixed tissue mast cells) and thus have access to different IL-4-responsive target cells. In addition, these cells appear to regulate IL-4 expression in cell-type-specific ways. These findings suggest that an understanding of IL-4 gene regulation in T and mast cells could provide the means to specifically control IL-4 release in a lineage- and site-specific manner. In this article we review the current knowledge regarding the cell-type specific regulation of IL-4 gene expression in mast cells and compare this to what has been defined in T cells. We show that there are distinct yet parallel events that control developmentally determined chromatin modifications, allowing accessibility of the locus, and provide the potential for transcription. In differentiated cells, a subset of unique cell activation signals initiates the cascade of events that lead to transcriptional activation of the IL-4 gene.

A library to support a graphics-based object-first approach to CS 1

Abstract: In this paper we describe a library we have developed that supports an "OO-from-the-beginning" approach to CS 1. The use of real graphics "objects" and event-driven programming are important components of our approach. The design of interactive graphical programs helps students to both use objects and write methods early while designing and implementing interesting programs.

Post-Crisis Exchange Rate Policy in Five Asian Countries; Filling in the "Hollow Middle"?

Abstract: Following the 1997-98 financial turmoil, crisis countries in Asia moved toward either floating or fixed exchange rate systems, reinforcing the bipolar view of exchange rate regimes and the "hollow middle" hypothesis. But some academics have claimed that the crisis countries' policies have been similar in the post- and pre-crisis periods. This paper analyzes the evidence and concludes that, except for Malaysia, which adopted a hard peg and imposed capital controls, the other crisis countries are floating more than before, though less than "real" floaters do. Further, the crisis countries' policies during the post-crisis period can be justified on second-best arguments.