1,373 research outputs found
Calibration, validation and the NERC Airborne Remote Sensing Facility
The application of airborne and satellite remote sensing to terrestrial applications has been dominated by empirically-based, semi-quantitative approaches, in contrast to those developed in the marine and atmospheric sciences which have often developed from rigorous physically-based models. Furthermore, the traceability of EO data and the methodological basis of many applications has often been taken for granted, with the result that the repeatability of analyses and the reliability of many terrestrial EO products can be questioned. âNCAVEOâ is a recently established network of Earth Observation experts and data users committed to exchanging knowledge and understanding in the area of remote sensing data calibration and validation. It aims to provide a UK-based forum to collate available knowledge and expertise associated with the calibration and validation of EO-based products from both UK and overseas providers, in different discipline areas including land, ocean and atmosphere. This paper will introduce NCAVEO and highlight some of the contributions it hopes to make to airborne remote sensing in the UK
Address of Justice Edward J. Fox of the Supreme Court of Pennsylvania
Address of Justice Edward J. Fox of the Supreme Court of Pennsylvania at the dedication of Trickett Hall at the Dickinson School of Law. Originally published in Volume 23 of the Dickinson Law Review, 1918. [23 Dick. L. Rev. 11 (1918)]
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Economic Crises and the Integration of Law and Finance: The Impact of Volatility Spikes
The 2008 financial crisis raised puzzles important for understanding how the capital market prices common stocks and in turn, for the intersection between law and finance. During the crisis, there was a dramatic five-fold spike, across all industries, in âidioÂsyncratic riskââthe volatility of individual-firm share prices after adjustment for movements in the market as a whole.
This phenomenon is not limited to the most recent financial crisis. This Article uses an empirical review to show that a dramatic spike in idiosyncratic risk has occurred with every major downturn from the 1920s through the recent financial crisis. It canvasses three possible explanations for this phenomenon. Thereafter, this Article explores the implications of these crisis-induced volatility spikes for certain legal issues that depend analytically on valuation methodology and hence are affected by volatility: using event studies to determine materiality and loss causation in fraud-on-the-market securities litigation, determining materiality in cases involving claims of both insider trading and misstatements or omissions in registered public offerings, and deterÂmining the extent of deference given to a corporate board that rejects an acquisition offer at a premium above the pre-offer market price.
This analysis shows that the conventional use of event studies during periods of economic-crisis-induced volatility spikes results in understating the number of occasions when a corporate misstatement can be shown to have had a meaningful impact on a firmâs stock price. Relatedly, the analysis suggests that during crisis times, insiders have substantially more opportunities to profit from trading on the nonpublic information that they possess and issuers conducting offerings have more opportunities to sell securities at an inflated price. Analysis shows that trying to cure this problem by lowering the standard of what is considered statistically significant is as likely to be socially harmful as socially beneficial. These conclusions counsel that the best response to the reduced effectiveness of private litigation as a deterrent to securities law violations during crisis times is to provide additional resources to SEC enforcement. Lastly, with respect to Delaware courtsâ recognition of âsubstantive coercionâ as a justification for target-corporation deployÂment of takeover defensesâarguably a dubious justification in normal timesâcrisis-induced idiosyncratic-risk spikes provide an unusually plausible claim that target shareholders may indeed make a mistake in tendering into a hostile offer. Analysis of the timing of the spikes in recent cases, however, shows that the claim is tenuous even in these circumstances
Idiosyncratic Risk During Economic Downturns: Implications for the Use of Event Studies in Securities Litigation
We reported in a recent paper that during the 2008-09 financial crisis, for the average firm, idiosyncratic risk, as measured by variance, increased by five-fold. This finding is important for securities litigation because idiosyncratic risk plays a central role in event study methodology. Event studies are commonly used in securities litigation to determine materiality and loss causation. Many bits of news affect an issuerâs share price at the time of a corporate disclosure that is the subject of litigation. Because of this, even if an issuerâs marketâadjusted price changes at the time of the disclosure, one cannot determine with certainty whether the disclosure itself had any effect on price. An event study is used to make a probabilistic assessment of whether in fact it did. Use of event studies generates a certain rate of Type I errors (disclosures that had no actual effect on price being identified as having had an effect) and a certain rate of Type II errors (disclosures that had an actual effect not being identified as such). This paper sets out a simple model of the tradeoff between these Type I and Type II errors. The model is used to establish three fundamental points. First, an economic crisis can radically worsen this tradeoff by making it much more difficult to catch a disclosure of a certain size without introducing more Type I errors. Second, during crisis periods a relaxation of this standard (and hence an increase in the acceptable rate of Type I errors) may actually decrease Type II errors by less than it would in normal times. We prove that whether the decrease is greater or smaller in crisis times depends on whether the disclosureâs actual impact on price is more or less negative than a definable crossover point. Third, whether relaxation of the standard in troubled times would increase or decrease social welfare is ambiguous. It depends on distribution of potentially actionable disclosures in terms of their actual impact on price and the social costs and social benefits of imposing liability for disclosures of each given level of actual negative impact on price
Comparison of osteoporosis pharmacotherapy fracture rates: Analysis of a marketScanÂź claims database cohort
Background: Several different classes of medications have been shown to be efficacious at preventing fractures in patients with osteoporosis. No study has compared real world efficacy at preventing fractures between all currently approved medications.
Objectives: To directly compare the efficacy of all currently available osteoporosis medications by using a large population claims database.
Methods: The Truven Health Analytics MarketScanÂź database from 2008 - 2012 was used to identify all patients who started a new osteoporosis medication. Patients who experienced a fracture after at least 12 months of treatment were identified and risk factors for fracture for all patients were recorded. Logistic regression was used to account for and quantify the contribution of risk factors, and to make direct comparisons between different osteoporosis medications.
Results: A total of 51649 patients were included in the cohort, with an average age of 56 years. The overall incidence rate of fracture was 1.55 per 100 person - years of treatment. Orally administered medications had the lowest fracture rates, led by raloxifene and alendronate (1.24 and 1.54 respectively), while parenterally administered medications including teriparatide and zolerdonic acid had the highest rates (3.90 and 1.98 respectively). No statistically significant differences found between oral or parenterally administered bisphosphonate medications.
Conclusions: While patients taking orally administered drugs including bisphosphonates had less frequent incident fracture no statistically significant differences were found between most drugs in head - to - head comparisons, even considering the route of administration of bisphosphonates. These findings support previous evidence that minimal differences in efficacy exist between different osteoporosis medications. This is the first study using a large database to compare all currently available osteoporosis treatments and will hopefully be augmented by further study to provide more evidence to make clinical decisions on osteoporosis medication use.
© 2017 American Association of Neuropathologists, Inc
Poster 213: Health and Function Data From an Adult Cerebral Palsy Clinic: Initial Report
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146951/1/pmr2s196.pd
Poster 367 Adiposity Moderates the Association Between Gross Motor Functional System and Vitamin D Status Among Adults With Cerebral Palsy
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147042/1/pmr2s301.pd
Alemtuzumab improves neurological functional systems in treatment-naive relapsing-remitting multiple sclerosis patients.
BACKGROUND: Individual functional system scores (FSS) of the Expanded Disability Status Scale (EDSS) play a central role in determining the overall EDSS score in patients with early-stage multiple sclerosis (MS). Alemtuzumab treatment improves preexisting disability for many patients; however, it is unknown whether improvement is specific to certain functional systems. OBJECTIVE: We assessed the effect of alemtuzumab on individual FSS of the EDSS. METHODS: CAMMS223 was a 36-month, rater-blinded, phase 2 trial; treatment-naive patients with active relapsing-remitting MS, EDSS â€3, and symptom onset within 3 years were randomized to annual courses of alemtuzumab or subcutaneous interferon beta-1a (SC IFNB-1a) 44 ÎŒg three times weekly. RESULTS: Alemtuzumab-treated patients had improved outcomes versus SC IFNB-1a patients on most FSS at Month 36; the greatest effect occurred for sensory, pyramidal, and cerebellar FSS. Among patients who experienced 6-month sustained accumulation of disability, clinical worsening occurred most frequently in the brainstem and sensory systems. For patients with 6-month sustained reduction in preexisting disability, pyramidal and sensory systems contributed most frequently to clinical improvement. CONCLUSIONS: Alemtuzumab demonstrated a broad treatment effect in improving preexisting disability. These findings may influence treatment decisions in patients with early, active relapsing-remitting MS displaying neurological deficits. ClinicalTrials.gov Identifier NCT00050778.Funding was provided by Sanofi Genzyme and Bayer Healthcare Pharmaceuticals.
The authors would like to thank Marco Rizzo and Isabel Firmino for reviewing and providing input on the manuscript; Isabel Firmino is an employee of Sanofi Genzyme; Marco Rizzo was an employee of Sanofi Genzyme at the time the work was conducted. Data analysis was carried out by Linda Kasten, PROMETRIKA, LLC, Cambridge, MA, USA, which was supported by Sanofi Genzyme. Editorial support for this manuscript was provided by Fiona Nitsche, PhD, and Susan M Kaup, PhD, which was funded by Sanofi Genzyme. Fiona Nitsche is an employee of Evidence Scientific Solutions; Susan M Kaup was an employee of Evidence Scientific Solutions at the time the work was conducted.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.jns.2016.02.02
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