Binomial confidence intervals for rare events: importance of defining margin of error relative to magnitude of proportion

Confidence interval performance is typically assessed in terms of two criteria: coverage probability and interval width (or margin of error). In this work we detail the importance of defining the margin of error relative to the magnitude of the estimated proportion when the success probability is small. We compare the performance of four common proportion estimators: the Wald, Clopper-Pearson, Wilson and Agresti-Coull, in the context of rare-event probabilities. We show that incompatibilities between the margin of error and the proportion results in very narrow intervals (requiring extremely large sample sizes), or intervals that are too wide to be practically useful. We propose a relative margin of error scheme that is consistent with the order of magnitude of the proportion. Confidence interval performance is thus assessed in terms of satisfying this relative margin of error, in conjunction with achieving a desired coverage probability. We show that when adherence to this relative margin of error is considered as a requirement for satisfactory interval performance, all four interval estimators perform somewhat similarly for a given sample size and confidence level. The proposed relative margin of error scheme is evaluated by way of its application to a number of recent studies from the literature.Comment: 25 pages, 3 figure

Cocaine surface contamination and the medico-legal implications of its transfer

AbstractThe question posed by this research involves how frequently one can expect to contact cocaine in day-to-day living experiences where drug use may not normally be suspected. Issues concerning contamination are germane to medico-legal investigators who evaluate the significance of drug test results in (1) questioned deaths, (2) public health concerns, (3) drugs crimes, and (4) drug use toxicological tests potentially caused by external contamination, such as hair, sweat, and skin swabs. Previous surface studies focus mainly on currency drug contamination; few have addressed other common surfaces.Public surfaces handled by a large number of people, such as building entrance door handles, bank currency dispensing machines, food store shopping carts, and service station fuel pumps within the New Haven, Connecticut metropolitan area were tested. Socio-economically, the distribution of items tested ranged from working-class to upper-middle class areas. Results were obtained using the Securetec Drugwipe II® which is an immunological, on-site test device. Precautions were taken to avoid carry-over and other potential contamination from handling including single-use latex gloves which were pre-tested as a negative control immediately before swabbing. Analysis was performed according to the manufacturer’s instructions and in the laboratory to standardize conditions. Drugwipe II® limit of detection (LOD) is ∼50ng.Test results revealed 78% positive for cocaine substances as follows: fuel pump buttons for credit card authorization, 100% positive (n=10 individual locations); ATM machines for currency withdrawal, 100% positive (n=10 individual locations); grocery store shopping carts, 70% positive; academic building entrance doors, 30% positive (n=10); and shopping mall entrance/exit doors, 100% positive (n=5).Forensic scientists and medico-legal investigators responsible for interpreting surface test results are cautioned to consider contamination before ascribing drug activity to a specific individual. For legal proceedings these results are indicative but not conclusive because immunological tests are considered presumptive and may react with the parent substance (cocaine), related compounds (benzoylecgonine, ecgonine methyl ester, ecgonine, nor-ecgonine, and cocaethylene) and immunologically similar materials

Sheathing the Sword of Damocles: Assessing Al Qaeda and Devising a US Response

Al Qaeda killed over 3,000 US citizens on September 11, 2001, and terrorism leapt to the fore of US strategic and political priorities. Yet, after nearly six year of concerted effort by the United States, the dominant power in the international system, Al Qaeda survives and is still acknowledged as a potent threat. This begs the question not just of why, but of what the United States can do to redress the situation. This dissertation seeks answers by examining the four key aspects of Al Qaeda that enable it function as a successful terrorist entity - strategy, organization, financing, and politics. These factors area analyzed relative to the dynamics of the phenomenon of terrorism in the US-Al Qaeda struggle. For each variable, Al Qaeda's perspective and efforts, as well as the perspective and efforts of the United States, are scrutinized. This dissertation assesses Al Qaeda is primarily a political threat, not a military one. Terrorists subvert legitimate political processes to achieve political ends. Al Qaeda challenges not only specific US political decisions, but also the very nature of the US political system, a classical liberal democracy, and the nature of the US-created post World War II international order. The character of the US political response is critical. As such, this dissertation concludes that US efforts to combat such a threat cannot be limited solely to a hard power approach. Such a component must be present in US strategy, for it alone directly degrades Al Qaeda's capacity for violence, the source of its power. The US approach must, however, include a greater emphasis on the US-Al Qaeda struggle's political dimension. The political aspect both drives the conflict and frames its execution, thus shaping the possible outcomes in both the near and far term. Fortunately, as the leader of the international system, the United States is in a position to politically undercut Al Qaeda. The United States can do so by adhering to globally revered traditional US political values and foreign policy emphases - the rule of law, a participatory political system emphasizing the importance of international institutions, and democratic values, such as human rights - in not just the execution, but also the formulation of US policy. The potential impact is significant. Internally, manipulating the US-Al Qaeda struggle's political dimension in accordance with traditional US values can weaken Al Qaeda's internal cohesion. Externally, the United States can narrow Al Qaeda's room for maneuver by depriving it of political support, thus strategically degrading Al Qaeda's operational capability. In the process, the United States will also stunt the terrorism process's subversive effects on the United States' political character. In short, addressing the US-Al Qaeda struggle's political dimension in a manner consistent with traditional US political values ensures US political integrity while also yielding national advantage

Current and Future Applications of Multispectral (RGB) Satellite Imagery for Weather Analysis and Forecasting Applications

Current and future satellite sensors provide remotely sensed quantities from a variety of wavelengths ranging from the visible to the passive microwave, from both geostationary and low ]Earth orbits. The NASA Short ]term Prediction Research and Transition (SPoRT) Center has a long history of providing multispectral imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA fs Terra and Aqua satellites in support of NWS forecast office activities. Products from MODIS have recently been extended to include a broader suite of multispectral imagery similar to those developed by EUMETSAT, based upon the spectral channels available from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) aboard METEOSAT ]9. This broader suite includes products that discriminate between air mass types associated with synoptic ]scale features, assists in the identification of dust, and improves upon paired channel difference detection of fog and low cloud events. Future instruments will continue the availability of these products and also expand upon current capabilities. The Advanced Baseline Imager (ABI) on GOES ]R will improve the spectral, spatial, and temporal resolution of our current geostationary capabilities, and the recent launch of the Suomi National Polar ]Orbiting Partnership (S ]NPP) carries instruments such as the Visible Infrared Imager Radiometer Suite (VIIRS), the Cross ]track Infrared Sounder (CrIS), and the Advanced Technology Microwave Sounder (ATMS), which have unrivaled spectral and spatial resolution, as precursors to the JPSS era (i.e., the next generation of polar orbiting satellites. New applications from VIIRS extend multispectral composites available from MODIS and SEVIRI while adding new capabilities through incorporation of additional CrIS channels or information from the Near Constant Contrast or gDay ]Night Band h, which provides moonlit reflectance from clouds and detection of fires or city lights. This presentation will present a review of SPoRT, CIRA, and NRL collaborations regarding multispectral satellite imagery and recent applications within the operational forecasting environmen

A feasibility study of a binocular modification of the standard OEP 21 point exam

In order to evaluate the feasibility of a binocular modification of the standard OEP 21 point examination sequence, nineteen fourth year clinicians from Pacific University College of Optometry were exposed to the proposed exam routine. The binocularity is obtained by using a -+1.00 occluder lens rather than an opaque occluder on any of the tests which are normally done monocularly. The clinicians were asked to respond to a questionnaire when they felt they could adequately evaluate the binocular exam routine. The responses were extremely favorable. The subjects indicated that the routine would be useful for examining many different types of patients. Some of the subjects indicated that this routine could replace the Polaroid binocular system now used. The routine requires no special equipment and is readily adapted to current exam sequenses. This monocular fogging technique shows promise as a possible binocular refraction routine

Current and Future Applications of Multispectral (RGB) Satellite Imagery for Weather Analysis and Forecasting

No abstract availabl

The Use of NASA near Real-time and Archived Satellite Data to Support Disaster Assessment

With support from a NASA's Applied Sciences Program, The Shortterm Prediction Research and Transition (SPoRT) Center has explored a variety of techniques for utilizing archived and near realtime NASA satellite data to support disaster assessment activities. MODIS data from the NASA Land Atmosphere Near Realtime Capability for EOS currently provides true color and other imagery for assessment and potential applications including, but not limited to, flooding, fires, and tornadoes. In May 2013, the SPoRT Center developed unique power outage composites using the VIIRS Day/Night Band to represent the first clear sky view of damage inflicted upon Moore and Oklahoma City, Oklahoma following the devastating EF5 tornado that occurred on May 20. Preevent imagery provided by the NASA funded WebEnabled Landsat Data project offer a basis of comparison for monitoring post-disaster recovery efforts. Techniques have also been developed to generate products from higher resolution imagery from the recently available International Space Station SERVIR Environmental Research and Visualization System instrument. Of paramount importance is to deliver these products to end users expeditiously and in formats compatible with Decision Support Systems (DSS). Delivery techniques include a Tile Map Service (TMS) and a Web Mapping Service (WMS). These mechanisms allow easy integration of satellite products into DSS's, including the National Weather Service's Damage Assessment Toolkit for use by personnel conducting damage surveys. This poster will present an overview of the developed techniques and products and compare the strengths and weaknesses of the TMS and WMS

Upper Atmospheric Monitoring for Ares I-X Ascent Loads and Trajectory Evaluation on the Day-of-Launch

During the launch countdown of the Ares I-X test vehicle, engineers from Langley Research Center will use profiles of atmospheric density and winds in evaluating vehicle ascent loads and controllability. A schedule for the release of balloons to measure atmospheric density and winds has been developed by the Natural Environments Branch at Marshall Space Flight Center to help ensure timely evaluation of the vehicle ascent loads and controllability parameters and support a successful launch of the Ares I-X vehicle

Enantioselective Methods for Allylic Substitution and Conjugate Addition Reactions Catalyzed by N-Heterocyclic Carbene-Copper Complexes

Thesis advisor: Amir H. HoveydaChapter 1 Catalytic Enantioselective Addition of Organoaluminum Reagents Catalytic methods involving the enantioselective addition of both commercially available as well as in situ generated organoaluminum reagents are reviewed. An overview of additions to aldehydes, ketones, and imines is provided as well as the difficulties and limitations of such transformations. Furthermore, additions to unsaturation adjacent to a leaving group to form a new stereogenic center are examined. Finally, conjugate addition reactions wherein an organoaluminum reagent is added to an olefin adjacent to a carbonyl or nitro group are discussed. Chapter 2 Synthesis of Quaternary Carbon Stereogenic Centers through Enantioselective Cu-Catalyzed Allylic Substitution with Alkenylaluminum Reagents A method for the formation of 1,4-diene containing quaternary stereogenic centers through catalytic enantioselective allylic substitution is disclosed. The addition of alkyl- and aryl-substituted alkenylaluminum reagents to trisubstituted allylic phosphates is promoted by 0.5–2.5 mol % of a sulfonate-containing bidentate N-heterocyclic carbene–copper complex. Products containing a quaternary stereogenic center as well as a newly formed terminal olefin are obtained in up to 97% yield and 99:1 er with high site selectivity (>98:2 SN2’:SN2). The requisite nucleophiles are generated in situ through hydroalumination of terminal alkynes. The utility of the method is demonstrated through a concise synthesis of natural product bakuchiol. Chapter 3 A Multicomponent Ni-, Zr-, Cu-Catalyzed Strategy for Enantioselective Synthesis of Alkenyl-Substituted Quaternary Carbons Despite the widespread use of conjugate addition in organic synthesis, few reports pertain to the addition of nucleophiles to acyclic systems and none in which the nucleophile is an alkene. Herein, we report the first examples of enantioselective conjugate addition of alkenylmetal reagents to trisubstituted enones to form all-carbon quaternary stereogenic centers. Alkenylaluminum nucleophiles are prepared through a site-selective Ni-catalyzed hydroalumination of terminal alkynes and the requisite E-trisubsituted enones are the products of a regioselective Zr-catalyzed carboalumination/acylation of a terminal alkyne. Products are obtained in up to 97% yield and 99:1 er. A model for enantioselectivity, supported by DFT calculations, is proposed. Chapter 4 Formation of Tertiary Centers through Catalytic Enantioselective Conjugate Addition of Alkenylaluminum Reagents to Acyclic Enones We have developed an enantioselective NHC–Cu catalyzed synthesis of tertiary centers in acyclic systems using in situ generated alkenylaluminum reagents, as current methods typically rely on Rh-catalysis at high temperatures with alkenyl boronic acids in protic solvents. Moreover, most examples include chalcone-derived substrates, which, while more reactive, often preclude further functionalization. With the current method, we are able to couple a variety of alkenyl nucleophiles with α,β-unsaturated ketones. E- or Z-silylalkenylaluminum reagents, derived from hydroalumination of silyl-protected alkynes, lead to products in good yields and high enantioselectivities. Additionally, both the α- and β-alkenylaluminum reagents participate in the reaction. Chapter 5 Development of N-Heterocyclic Carbene–Cu Catalyzed Allylic Substitution of Diboryl Methane to Morita-Baylis-Hillman Derived Allylic Phosphates We have developed a method for the coupling of a geminyl diboron reagent with Morita-Baylis-Hillman derived trisubstituted ester-containing allylic phosphates. With 10 mol % of an in situ generated NHC–Cu complex and 1.5 equivalents of the boron reagent, we are able to form the desired product in high regio- and enantioselectivity with a 2,5-ditert-butyl containing carbene. Simple aryl substituents as well as those containing a halogen or an electron-withdrawing group furnish the desired products in up to 85% yield and 98:2 er. Alkyl-containing substrates are also competent reaction partners, although longer chain aliphatics results in slightly diminished enantioselectivity. We are pursuing the application of this method to the synthesis of α-methylene lactones which can be further functionalized to natural products like tubulin polymerization inhibitor (–)-steganone and glaucoma medication (+)-pilocarpine.Thesis (PhD) — Boston College, 2016.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Chemistry