Building a Bird: Musculoskeletal Modeling and Simulation of Wing-Assisted Incline Running during Avian Ontogeny

Flapping flight is the most power-demanding mode of locomotion, associated with a suite of anatomical specializations in extant adult birds. In contrast, many developing birds use their forelimbs to negotiate environments long before acquiring “flight adaptations,” recruiting their developing wings to continuously enhance leg performance and, in some cases, fly. How does anatomical development influence these locomotor behaviors? Isolating morphological contributions to wing performance is extremely challenging using purely empirical approaches. However, musculoskeletal modeling and simulation techniques can incorporate empirical data to explicitly examine the functional consequences of changing morphology by manipulating anatomical parameters individually and estimating their effects on locomotion. To assess how ontogenetic changes in anatomy affect locomotor capacity, we combined existing empirical data on muscle morphology, skeletal kinematics, and aerodynamic force production with advanced biomechanical modeling and simulation techniques to analyze the ontogeny of pectoral limb function in a precocial ground bird (Alectoris chukar). Simulations of wing-assisted incline running (WAIR) using these newly developed musculoskeletal models collectively suggest that immature birds have excess muscle capacity and are limited more by feather morphology, possibly because feathers grow more quickly and have a different style of growth than bones and muscles. These results provide critical information about the ontogeny and evolution of avian locomotion by (i) establishing how muscular and aerodynamic forces interface with the skeletal system to generate movement in morphing juvenile birds, and (ii) providing a benchmark to inform biomechanical modeling and simulation of other locomotor behaviors, both across extant species and among extinct theropod dinosaurs

Has the housing boom increased mortgage risk?

Adjustable rate mortgages

Auditing the auditors: oversight or overkill?

A growing number of high-profile companies have had to restate their earnings at substantially lower levels to correct the prior use of "aggressive" and even fraudulent accounting practices. Because the companies’ auditors approved the original reports, policymakers have questioned the capacity of public accounting firms to promote fair financial reporting. In response, recent legislation has instituted several reforms, including the creation of the Public Company Accounting Oversight Board, which together with the Securities and Exchange Commission will investigate alleged lapses in accounting practices. But how much oversight is really necessary? Jeffery Gunther and Robert Moore examine recent events in the light of research findings. Based on this analysis, they conclude that market forces have tended, over time, to shape the role of auditors to match or correspond to the needs of investors in monitoring individual companies’ performance. Despite current sentiment to the contrary, substantial government involvement in the business of auditing appears to be needed only when other types of government intervention, such as bank deposit insurance, have already disrupted market-based incentives for effective audits. In the more typical situation, both government and industry policymakers should avoid restrictive measures that unnecessarily increase audit costs, instead taking into account market forces’ successful track record in disciplining ineffective auditors and promoting an effective audit function.>Securities and Exchange Commission ; Accounting

Financial statements and reality: do troubled banks tell all?

Each quarter, banks file a call report, or Report of Condition and Income, containing hundreds of accounting items pertaining to their financial condition. This article analyzes call report revisions to assess the extent to which regulatory exams promote accurate data. The findings indicate banks with new or emerging difficulties often significantly underreport these problems, intentionally or not. In addition, the findings point to a significant role for exams in uncovering financial problems and ensuring bank accounting statements reflect them. To the extent the loan-loss accounting in call reports is widely used to assess loan quality, these results support the view that exams are important in the public dissemination of accurate information on banks' financial condition.

Early warning models in real time

Each quarter, banks file a call report, or Report of Condition and Income, containing hundreds of accounting items pertaining to their financial condition. Because call reports are filed quarterly, whereas banks are typically examined about once every twelve to eighteen months, statistical early warning models using call report data potentially provide a more up-to-date picture of a bank's condition than on-site exams alone. Often neglected, however, is the fact that call report data are subject to revision. We find evidence of a strong relationship between on-site exams and call report revisions. In addition, we evaluate a major class of early warning models using both originally published and revised data to assess whether model accuracy in real time is appreciably lower than accuracy measured using revised data. The findings indicate revised data overstate the accuracy of early warning models. The substantial effect of revisions on the accuracy of early warning models, coupled with the finding of a relationship between revisions and exams, points to a substantial auditing role for on-site exams. More generally, our findings point to the need for care in the use of call report data for research in which the real-time flow of financial information is of some concern.Econometrics ; Banks and banking - Accounting ; Bank supervision

Quick Guide To Quattro Pro for Windows: For Mouse Users

Research Methods/ Statistical Methods,

Universal access, cost recovery, and payment services

We suggest a subtle, yet far- reaching, tension in the objectives specified by the Monetary Control Act of 1980 (MCA) for the Federal Reserve’s role in providing retail payment services, such as check processing. Specifically, we argue that the requirement of an overall cost-revenue match, coupled with the goal of ensuring equitable access on a universal basis, partially shifted the burden of cost recovery from high-cost to low-cost service points during the MCA’s early years, thereby allowing private-sector competitors to enter the low-cost segment of the market and undercut the relatively uniform prices charged by the Fed. To illustrate this conflict, we develop a voter model for what begins as a monopoly setting in which a regulatory regime that establishes a uniform price irrespective of cost differences, and restricts total profits to zero, initially dominates through majority rule both deregulation and regulation that sets price equal to cost on a bank-by-bank basis. Uniform pricing is dropped in this model once cream skimming has subsumed half the market. These results help illumine the Federal Reserve’s experience in retail payments under the MCA, particularly the movement over time to a less uniform fee structure for check processing.Payment systems ; Check collection systems

"The riots were where the police were": Deconstructing the Pendelton Riot

This article explores the social dynamics in the city of Salford at the time of the Pendleton riot, which took place amidst the four days of national rioting that began with the killing of Mark Duggan in Tottenham by the Metropolitan Police Service. Attempting to counter what we see as a dominant narrative of the riots as 'shopping with violence', this article explores the development of the significant disorder in Salford through a triangulation of accounts, including an extensive review of journalistic accounts, alongside interviews from a dozen people who witnessed the riots as police officers, residents and spectators. Beginning with an overview of the events of August 9th 2011, we argue that the deployment of officers in riots gear in the vicinity of Salford Precinct proved provocative, and created a focal point for the widespread antagonism felt towards the police. Furthermore, we suggest that an understanding of local contextual factors is critical both in terms of answering the question ‘why Salford?’, but also in terms of explaining the ferocity of the violence targeted towards officers of Greater Manchester Police (in contrast to the focus on looting in nearby Manchester city-centre). Interpreting the riots as a response to punitive policing policies that have accompanied state-directed policies of large-scale gentrification, we highlight the degree to which the 'contestations over space' that characterised the riot pointed to an underlying politics of resistance (despite lacking 'formal' political articulation)

Can the stock market tell bank supervisors anything they don't already know?

This article provides evidence consistent with recent policy proposals calling for a greater role for market forces in promoting a safe and sound financial system. The authors' empirical results indicate a measure of expected default probability distilled from equity prices helps predict the financial condition of individual banking organizations, as reflected in their supervisory ratings. Moreover, the stock market data have predictive power over and above the information in the quarterly financial statements available to supervisors between inspections. These findings suggest financial markets can provide useful information to supplement supervisory assessments, particularly between inspections, and point to the value of additional research to further clarify the information content of market prices and quantities.Banks and banking ; Bank examination ; Bank supervision