Home About us Contact
|
Home About us Contact | ||
|
|
||
Instruments
Kinds of Instruments Terms modified by Instruments Selected AbstractsCONVERTIBLE SECURITIES: A TOLLBOX OF FLEXIBLE FINANCIAL INSTRUMENTS FOR CORPORATE ISSUERSJOURNAL OF APPLIED CORPORATE FINANCE, Issue 1 2000Trevor Ganshaw During the 1990s, convertible and equity-linked securities emerged as a major source of financing for U.S. corporate issuers. Issuance volume grew steadily throughout the decade and the secondary market value of U.S. convertible securities now exceeds $200 billion. In this overview of the market, the authors discuss the following: (1) the growth of issuance volume in the U.S. equity-linked market; (2) the basic characteristics of convertible securities; (3) convertible debt alternatives; and (4) convertible preferred alternatives. As a result of the proliferation of new convertible structures, corporate issuers are now able to adjust coupon/dividend, conversion premium, and call protection in order to meet their tax, accounting, rating agency, and cost-of-capital objectives. Historically, the convertible new issue market has had a broad variety of issuers, spanning all industry sectors as well as both investment grade and high yield credits. But in the last two years, the most aggressive issuers have been technology-oriented companies, including telecommunications, Internet, hardware, software, and biotechnology concerns. Such technology-related issuers, which are often rated below investment grade and unable to secure straight debt capital, are generally in heavy-spending phases and view convertible bonds as a source of inexpensive financing. At the same time, investment-grade, "old-economy" issuers have continued to use convertible securities selectively, in most cases as cheap "quasi-equity" in the context of mergers and acquisitions, or as a tax-deferred strategy for selling cross-holdings of stock. [source] MODEL UNCERTAINTY AND ITS IMPACT ON THE PRICING OF DERIVATIVE INSTRUMENTSMATHEMATICAL FINANCE, Issue 3 2006Rama Cont Uncertainty on the choice of an option pricing model can lead to "model risk" in the valuation of portfolios of options. After discussing some properties which a quantitative measure of model uncertainty should verify in order to be useful and relevant in the context of risk management of derivative instruments, we introduce a quantitative framework for measuring model uncertainty in the context of derivative pricing. Two methods are proposed: the first method is based on a coherent risk measure compatible with market prices of derivatives, while the second method is based on a convex risk measure. Our measures of model risk lead to a premium for model uncertainty which is comparable to other risk measures and compatible with observations of market prices of a set of benchmark derivatives. Finally, we discuss some implications for the management of "model risk." [source] THE SOCIAL EFFICIENCY OF INSTRUMENTS FOR THE PROMOTION OF RENEWABLE ENERGIES IN THE LIBERALISED POWER INDUSTRYANNALS OF PUBLIC AND COOPERATIVE ECONOMICS, Issue 3 2006Dominique Finon ABSTRACT,:,This paper compares the social efficiency of the two main regulatory instruments used to promote renewable energy sources in electricity generation (RES-E), taking into consideration their role in promoting the preservation of the climate. They are based on a purchase obligation and act either by price (feed-in tariffs) or by quantity (RES-E quotas). In their reference design, the instruments show different performances in several dimensions: market incentives intensity, control of the cost for consumers, safeguards of RES-E investments, and conformity with the new market regime of the electricity industry. The comparison shows that neither instrument offers an optimal solution in each of these dimensions. In particular, the intrinsic qualities of the quotas instrument that are put forward to mandate its adoption by the EU members are overestimated. A government will thus select an instrument in accordance with the relative importance of its objectives: environmental policy versus cost control by market pressure. [source] Powered Liposuction: An Evaluation of Currently Available InstrumentationDERMATOLOGIC SURGERY, Issue 5 2002Timothy Corcoran Flynn MD background. Over the past several years, powered liposuction instruments have become available to the dermatologic surgeon. These instruments all move the cannula forward and backward 2,12 mm with rapidity. This motion simulates the standard human movement of the cannula and facilitates movement through the tissue. Powered liposuction may help to prevent surgeon fatigue and has recently been shown to aid in the efficacy of fat removal. objective. To compare and contrast currently available powered liposuction instruments, to obtain objective engineering data on the instruments, and to compare the instruments when used on actual liposuction cases. methods. Five currently available powered liposuction systems were evaluated by the author. Each instrument was used with a 3 mm dual side port cannula on patients undergoing tumescent liposuction. An independent engineering firm, who collected objective measurements such as weight, stroke force, temperature, and vibration measurements on the instruments, evaluated the units. Noise measurements were obtained. results. Each of the five systems showed advantages and disadvantages. Important issues were the size and weight of the units, as well as whether they were driven electrically or pneumatically. Stroke force is variable (range 9.5,30 pounds). The noise of the units ranged between 60 and 87 dB. Vibration measurements varied from instrument to instrument. Units produced a variable amount of heat ranging from 77°F to 102°F. Most instruments are autoclavable, and one system is disposable. Build quality and reliability varied with the instrument. conclusion. Instruments for powered liposuction have emerged in the last 2 years, with each instrument having distinct advantages and disadvantages. This article reviews five currently available powered liposuction instruments and presents objective measurements as well as the author's experience using the instruments. [source] 3D In-Vivo Optical Skin Imaging for Topographical Quantitative Assessment of Non-Ablative Laser TechnologyDERMATOLOGIC SURGERY, Issue 3 2002Paul M. Friedman MD background. A new method for treating facial rhytides and acne scars with nonablative laser and light source techniques has recently been introduced. Given the inherent limitations of photographic and clinical evaluation to assess subtle changes in rhytides and surface topography, a new noninvasive objective assessment is required to accurately assess the outcomes of these procedures. objective. The purpose of this study was to measure and objectively quantify facial skin using a novel, noninvasive, In-vivo method for assessing three-dimensional topography. This device was used to quantify the efficacy of five treatment sessions with the 1064 nm QS Nd:YAG laser for rhytides and acne scarring, for up to six months following laser treatment. methods. Two subjects undergoing facial rejuvenation procedures were analyzed before and after therapy using a 30-mm, three-dimensional microtopography imaging system (PRIMOS, GFM, Teltow, Germany). The imaging system projects light on to a specific surface of the skin using a Digital Micromirror Device (DMDÔ Texas Instruments, Irving, TX) and records the image with a CCD camera. Skin Surface microtopography is reconstructed using temporal phase shift algorithms to generate three-dimensional images. Measurements were taken at baseline, at various times during the treatment protocol, and then at three and six-month follow-up visits. Silicone skin replicas (FLEXICO, Herts, England) were also made before and after the laser treatment protocol for comparison to In-vivo acquisition. results. Skin roughness decreased by 11% from baseline after three treatment sessions in the wrinkles subject, while a 26% improvement of skin roughness was recorded by 3D In-vivo assessment six months following the fifth treatment session. The subject with acne scarring demonstrated a 33% decrease in roughness analysis after three treatment sessions by 3D In-vivo assessment. A 61% improvement in surface topography was recorded 3-months following the fifth treatment session, which was maintained at the 6-month follow-up. conclusion. Three-dimensional In-vivo optical skin imaging provided a rapid and quantitative assessment of surface topography and facial fine lines following multiple treatment sessions with a 1064-nm QS Nd:YAG laser, correlating with clinical and subjective responses. This imaging technique provided objective verification and technical understanding of nonablative laser technology. Wrinkle depth and skin roughness decreased at the three and six-month follow-up evaluations by 3D In-vivo assessment, indicating ongoing dermal collagen remodeling after the laser treatment protocol. Future applications may include comparison of nonablative laser technology, optimization of treatment regimens, and objective evaluation of other aesthetic procedures performed by dermatologists. [source] Patient-assessed health outcome measures for diabetes: a structured reviewDIABETIC MEDICINE, Issue 1 2002A. M. Garratt Abstract Aims To identify available disease-specific measures of health-related quality of life (HRQL) for diabetes and to review evidence for the reliability, validity and responsiveness of instruments. Methods Systematic searches were used to identify instruments. Instruments were assessed against predefined inclusion and exclusion criteria. Letters were sent to authors requesting details of further instrument evaluation. Information relating to instrument content, patients, reliability, validity and responsiveness to change was extracted from published papers. Results The search produced 252 references. Nine instruments met the inclusion criteria: Appraisal of Diabetes Scale (ADS), Audit of Diabetes-Dependent Quality of Life (ADDQoL), Diabetes Health Profile (DHP-1, DHP-18), Diabetes Impact Measurement Scales (DIMS), Diabetes Quality of Life Measure (DQOL), Diabetes-Specific Quality of Life Scale (DSQOLS), Questionnaire on Stress in Diabetic Patients-Revised (QSD-R), Diabetes-39 (D-39) and Well-being Enquiry for Diabetics (WED). The shortest instrument (ADS) has seven items and the longest (WED) has 50 items. The ADS and ADDQoL are single-index measures. The seven multidimensional instruments have dimensions covering psychological well-being and social functioning but vary in the remainder of their content. The DHP-1 and DSQOLS are specific to Type 1 diabetes patients. The DHP-18 is specific to Type 2 diabetes patients. The DIMS and DQOL have weaker evidence for reliability and internal construct validity. Patients contributed to the content of the ADDQoL, DHP-1/18, DQOL, DSQOLS, D-39, QSD-R and WED. The authors of the ADDQoL, DHP-1/18, DQOL, DSQOLS gave explicit consideration to content validity. The construct validity of instruments was assessed through comparisons with instruments measuring related constructs and clinical and sociodemographic variables. None of the instruments has been formally assessed for responsiveness to changes in health. Conclusions Five of the diabetes-specific instruments have good evidence for reliability and internal and external construct validity: the ADDQoL, DHP-1/18, DSQOLS, D-39 and QSD-R. Instrument content should be assessed for relevance before application. The instruments should be evaluated concurrently for validity and responsiveness to important changes in health. [source] Choosing the Number of InstrumentsECONOMETRICA, Issue 5 2001Stephen G. Donald Properties of instrumental variable estimators are sensitive to the choice of valid instruments, even in large cross-section applications. In this paper we address this problem by deriving simple mean-square error criteria that can be minimized to choose the instrument set. We develop these criteria for two-stage least squares (2SLS), limited information maximum likelihood (LIML), and a bias adjusted version of 2SLS (B2SLS). We give a theoretical derivation of the mean-square error and show optimality. In Monte Carlo experiments we find that the instrument choice generally yields an improvement in performance. Also, in the Angrist and Krueger (1991) returns to education application, when the instrument set is chosen in the way we consider, it turns out that both 2SLS and LIML give similar (large) returns to education. [source] Instruments of the warning service for plant protection in Bayern (Germany),EPPO BULLETIN, Issue 1 2000H. Tischner The warning service for plant protection in Bayern (Germany) obtains its information mainly from its own observations. The appearance of pests (including diseases and weeds) is investigated in cultivated areas and field trials. Weather data complementary to the pest enquiries can be made available from a measuring network of 116 field weather stations and is used to estimate the development of pests in relation to weather requirements. For several fungi and animal pests, computer-based decision support systems (DSSs) and forecasting models are being used. The results are processed and passed on to farmers via circulars, branch reviews, public notices, telephonic announcement services, telefax services and the Internet. [source] A Memory of Arnold William Sametz Former editor of the,Monograph Series in Finance and Economics, now,Financial Markets, Institutions & InstrumentsFINANCIAL MARKETS, INSTITUTIONS & INSTRUMENTS, Issue 4 2009Emilia Carulli Szego No abstract is available for this article. [source] Economic Instruments to Improve UK Home Energy Efficiency without Negative Social Impacts,FISCAL STUDIES, Issue 1 2006Simon Dresner Abstract The research examined how to use economic instruments to reduce carbon emissions from the UK housing sector without causing negative impacts on the poorest households. Carbon taxes would worsen the problem of fuel poverty. Compensation mechanisms involving the tax and benefit system were examined, but found not to be entirely effective because of the enormous range in the existing energy efficiency of homes. Exemptions for low-income households were examined, but found impractical to target. It was concluded that the best way to use economic instruments was through a scheme involving energy audits and surcharges to council tax and stamp duty for homeowners who failed to make cost-effective energy efficiency improvements within a specified time, with grants and loans to assist low-income households. After the implementation of such a scheme for 10 years, it would be practical to introduce a targeted carbon tax. [source] An in vitro comparison of canal preparation using two automated rotary nickel,titanium instrumentation techniquesINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2000S. J. Jardine Abstract Aim The aim of this study was to compare the efficacy of root canal preparation using two automated rotary nickel,titanium instrumentation techniques with a double flared balanced forces hand preparation technique, using stainless steel files in extracted human teeth. Methodology Sixty root canals in extracted human teeth were matched for curvature, length and diameter and divided evenly between three groups (group 1 = double flare using Flexofiles®, group 2 = rotary nickel,titanium using McXIM® instruments and group 3 = rotary nickel,titanium using Profile® .04 TaperTM Series 29 instruments). The instruments were used according to the manufacturer's instructions in a torque controlled motor and handpiece (groups 2 and 3) and according to a predetermined procedure in group 1. A standardized radiographic technique using mercury as a contrast medium was used to evaluate the canal shape before and after preparation in the plane of maximum curvature. The pre- and postoperative radiographic images were compared against each other and with a predicted ,ideal preparation' calculated from a projection of the final instrument dimensions. The outcome measures were changes in canal dimensions as quantified by measuring the changes in the position of the inner and outer wall at 1 mm intervals. Alteration in canal curvature could be inferred by comparison with the ideal preparation. Results The degree of canal curvature did not influence the effectiveness of any of the techniques. The results showed no statistically significant differences in the outcome measures between the groups (two-way anova). There were no significant differences in canal wall position changes at any level except the apical three, where significantly less change occurred in all groups (P = 1%). Instruments fractured in three canals, with acute curves in groups 2 and 3. Conclusions Canal curvatures were equally and well maintained following preparation in all the groups, as long as the instrument did not fracture. [source] Oral health-related quality of life in children: Part I. How well do children know themselves?INTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 2 2008A systematic review Abstract:, Objective:, Paediatric oral disorders are likely to have a negative effect on the quality of life. Until recently, children's oral health-related quality of life (OHRQoL) was measured using parents as informants. Instruments have now been developed, which have demonstrated that with appropriate questionnaire techniques, valid and reliable information can be obtained from children. The aim of this study was to make a systematic review of the existing literature about child perceptions of OHRQoL and their validation. Methods:, A computerized search was conducted using Medline, ISI, Lilacs and Scielo for children's perception of OHRQoL. The inclusion criteria were: the articles should contain well-validated instruments and provide child perceptions of OHRQoL. Results:, From 89 records found, 13 fulfilled the criteria. All studies included in the critical appraisal of the project suggested good construct validity of overall child perceptions of OHRQoL. However, children's understanding of oral health and well-being are also affected by variables (age, age-related experiences, gender, race, education, culture, experiences related to oral conditions, opportunities for treatment, childhood period of changes, back-translating questionnaire, children self-perceived treatment need). Conclusions:, The structure of children's self-concept and health cognition is age-dependent as a result of their continuous cognitive, emotional, social and language development. By using appropriate questionnaire techniques, valid and reliable information can be obtained from children concerning their OHRQoL. [source] Ancient Remotely-Operated Instruments Recovered Under Water off the Israeli CoastINTERNATIONAL JOURNAL OF NAUTICAL ARCHAEOLOGY, Issue 2 2008Ehud Galili Underwater archaeological investigations in Israel have recovered instruments intended to be operated under water from a vessel on the surface, at depths and times beyond the ability of free divers. Some of these remotely-operated devices, including salvaging-rings, coral-harvesting devices, and grapnels, are described, classified and discussed. These humble but efficient instruments, the prototypes of sophisticated modern instruments, fulfilled necessary tasks in antiquity and are still being used today by traditional fishermen. © 2008 The Authors [source] Financial Integration in the EU: the First Phase of EU Endorsement of International Accounting Standards,JCMS: JOURNAL OF COMMON MARKET STUDIES, Issue 2 2008IAN DEWING In 2002 the EU adopted the Regulation which required European listed companies to prepare their consolidated accounts in accordance with international accounting standards from 2005 onwards. A novel set of structures for the endorsement of international accounting standards for use in the EU was put in place. This article examines the first phase of endorsement of international accounting standards in the context of the novel endorsement structures. The article concludes that problems over the endorsement of IAS 39 Financial Instruments: Recognition and Measurement reveals a number of significant policy implications for the EU including the difficulty of forming a European view, the role of private actors in EU regulation, and the issue that international standards largely reflect Anglo-Saxon accounting practices rather than continental European practices. [source] Trust in Nurses Scale: construct validity and internal reliability evaluationJOURNAL OF ADVANCED NURSING, Issue 3 2010Laurel E. Radwin radwin l.e. & cabral h.j. (2010) Trust in Nurses Scale: construct validity and internal reliability evaluation. Journal of Advanced Nursing66(3), 683,689. Abstract Aim., This paper is a report of the continued psychometric evaluation of the Trust in Nurses Scale. Background., Qualitative analyses indicate that trust in nurses is critically important to adult patients. Instruments that distinctively measure this concept are lacking. A middle-range theory of patient-centred nursing care provided the theoretical basis for the Trust in Nurses Scale. Content validity was assessed by an expert panel and patient interviews. Construct validity and reliability were found acceptable using multi-trait/multi-item analysis techniques. These findings were previously reported. Methods., Construct validity and reliability of the Trust in Nurses Scale was assessed in 2007 using data collected during 2004,2005 from 187 hospitalized patients in a haematology-oncology setting. Trust in nurses (the latent factor) was operationalized by five items (manifest variables) using confirmatory factor analyses. Fit statistics included comparative fit index, Tucker-Lewis Index, root mean square error of approximation and the standardized root mean square residual. Internal consistency reliability was assessed using coefficient alpha. Findings., Both a five-item and a four-item version demonstrate acceptable psychometric properties. The five-item version met three fit statistics criteria. Fifty-nine per cent of the variance was explained. A four-item version met all fit statistics criteria. Sixty-six per cent of the variance was explained. Acceptable internal consistency reliability was found for both versions. Conclusion., Previous psychometric testing of the Trust in Nurses Scale provided evidence of the instrument's reliability, content validity and construct validity. The presented analyses further support construct validity. Thus, cumulative findings indicate that the instrument measures with a few items the underlying concept of trust. [source] The Importance of Geriatric-Specific Instruments and Functional Status Assessment in Infectious Diseases Research: Time to Start Preaching to the Congregation Instead of the ChoirJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 10 2004Kevin P. High MD No abstract is available for this article. [source] Estimating the New Keynesian Phillips Curve: A Vertical Production Chain ApproachJOURNAL OF MONEY, CREDIT AND BANKING, Issue 4 2008ADAM HALE SHAPIRO New Keynesian Phillips Curve; generalized method of moments; vertical production chain; inflation It has become customary to estimate the New Keynesian Phillips Curve (NKPC) with generalized method of moments using a large instrument set that includes lags of variables that are ad hoc to the firm's price-decision problem. Researchers have also conventionally used real unit labor cost (RULC) as the proxy for real marginal cost even though it is difficult to support its significance. This paper introduces a new proxy for the real marginal cost term as well as a new instrument set, both of which are based on the micro foundations of the vertical chain of production. I find that the new proxy, based on input prices as opposed to wages, provides a more robust and significant fit to the model. Instruments that are based on the vertical chain of production appear to be both more valid and relevant toward the model. [source] The Nursing Worklife Model: Extending and Refining a New TheoryJOURNAL OF NURSING MANAGEMENT, Issue 3 2007CCRN, MILISA MANOJLOVICH PhD Aims, We tested a modification of Leiter and Laschinger's Nursing Worklife Model by examining the impact of structural empowerment on professional work environment factors that lead to nursing job satisfaction. Background, The original model explains how five magnet hospital practice domains described by Lake (2002) interact to influence nurses' work lives by either contributing to or mitigating burnout. Methods, A non-experimental design was used. Five hundred randomly selected nurses in Michigan were surveyed (response rate 66%, n = 332). Instruments included the Conditions for Work Effectiveness Questionnaire-II, the Practice Environment Scale of the Nursing Work Index, and the Index of Work Satisfaction. Path analysis was used to test the model. Results, The final model fit the data well (,2 = 96.4, d.f. = 10, NFI: 0.90, CFI: 0.43, RMSEA: 0.18), supporting both hypotheses. Conclusions, The expanded Nursing Worklife Model demonstrates the role of empowerment in creating positive practice conditions that contribute to job satisfaction. [source] Automating Standard Alcohol Use Assessment Instruments Via Interactive Voice Response TechnologyALCOHOLISM, Issue 2 2002James C. Mundt Background: Interactive voice response (IVR) technology integrates touch-tone telephones with computer-automated data processing. IVR offers a convenient, efficient method for remote collection of self-report data. Methods: Twenty-six subjects recruited from an outpatient alcohol treatment center completed IVR and paper/pencil versions of a demographic and drinking history questionnaire, Stages of Change Readiness and Treatment Eagerness Scale, Drinker Inventory of Consequences, Obsessive-Compulsive Drinking Scale, Alcohol Dependence Scale, and two numerical rating scales of craving and desire to drink during the prior week. Administration of the instruments in both formats was repeated 1 week later. The order of administration method was counterbalanced between subjects and reversed across data collection sessions. Scale and subscale scores from both methods were correlated within sessions. Test-retest correlations were also calculated for each method. A criterion of ,= 0.01 was used to control type I statistical error. Results: Intermethod correlations within each session were significant for all of the instruments administered. Test-retest correlations for both methods were also significant, except for the numerical ratings. Scores on the Alcohol Dependence Scale obtained via IVR were significantly lower than those collected by paper/pencil. Other differences between the data collection methods or across the sessions were inconsistent. The average IVR call length was 34 min and 23 sec. Paper/pencil forms required an average of 18 min and 38 sec to complete and an additional 10 min and 17 sec for data entry. Conclusions: IVR technology provides a convenient alternative to collecting self-report measures of treatment outcomes. Both paper/pencil and IVR assessments provide highly convergent data and demonstrate good test-retest reliability. Alcohol Dependence Scale score differences between methods highlight special considerations for IVR adaptation of existing paper/pencil instruments. Benefits of IVR include procedural standardization, automatic data scoring, direct electronic storage, and remote accessibility from multiple locations. [source] HYDROLOGIC MODELING OF A BIOINFILTRATION BEST MANAGEMENT PRACTICE,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 5 2006William Heasom ABSTRACT: The goal of this research was to develop a methodology for modeling a bioinfiltration best management practice (BMP) built in a dormitory area on the campus of Villanova University in Pennsylvania. The objectives were to quantify the behavior of the BMP through the different seasons and rainfall events; better understand the physical processes governing the system's behavior; and develop design criteria. The BMP was constructed in 2001 by excavating within an existing traffic island, backfilling with a sand/soil mixture, and planting with salt tolerant grasses and shrubs native to the Atlantic shore. It receives runoff from the asphalt (0.26 hectare) and turf (0.27 hectare) surfaces of the watershed. Monitoring supported by the hydrologic model shows that the facility infiltrates a significant fraction of the annual precipitation, substantially reducing the delivery of nonpoint source pollution and erosive surges downstream. A hydrologic model was developed using HEC-HMS to represent the site and the BMP using Green-Ampt and kinematic wave methods. Instruments allow comparison of the modeled and measured water budget parameters. The model, incorporating seasonally variable parameters, predicts the volumes infiltrated and bypassed by the BMP, confirming the applicability of the selected methods for the analysis of bioinfiltration BMPs. [source] Method and instruments for modeling integrated knowledgeKNOWLEDGE AND PROCESS MANAGEMENT: THE JOURNAL OF CORPORATE TRANSFORMATION, Issue 4 2008*Article first published online: 19 NOV 200, Olivier Glassey MIMIK (Method and Instruments for Modeling Integrated Knowledge) is a set of tools used to formalize and represent knowledge within organizations. It furthermore supports knowledge creation and sharing within communities of interest or communities of practice. In this paper we show that MIMIK is based on a model theory approach and builds on other existing methods and techniques. We also explain how to use the method and its instruments in order to model strategic objectives, processes, knowledge, and roles found within an organization, as well as relations existing between these elements. Indeed MIMIK provides eight types of models in order to describe what is commonly called know-how, know-why and know-what; it uses matrices in order to formally and semantically link strategic objectives, knowledge and actors. We close this paper with a presentation of a prototype we built in order to demonstrate a technical architecture allowing for knowledge creation, formalization and sharing. Copyright © 2008 John Wiley & Sons, Ltd. [source] High-energy femtosecond fiber lasers based on pulse propagation at normal dispersionLASER & PHOTONICS REVIEWS, Issue 1-2 2008F.W. Wise Abstract The generation and stable propagation of ultrashort optical pulses tend to be limited by accumulation of excessive nonlinear phase shifts. The limitations are particularly challenging in fiber-based devices, and as a result, short-pulse fiber lasers have lagged behind bulk solid-state lasers in performance. This article will review several new modes of pulse formation and propagation in fiber lasers. These modes exist with large normal cavity dispersion, and so are qualitatively distinct from the soliton-like processes that have been exploited effectively in modern femtosecond lasers but which are also quite limiting. Self-similar evolution can stabilize high-energy pulses in fiber lasers, and this leads to order-of-magnitude increases in performance: fiber lasers that generate 10 nJ pulses of 100 fs duration are now possible. Pulse-shaping based on spectral filtering of a phase-modulated pulse yields similar performance, from lasers that have no intracavity dispersion control. These new modes feature highly-chirped pulses in the laser cavity, and a theoretical framework offers the possibility of unifying our view of normal-dispersion femtosecond lasers. Instruments based on these new pulse-shaping mechanisms offer performance that is comparable to that of solid-state lasers but with the major practical advantages of fiber. [source] How Can We Improve the Accuracy of Screening Instruments?LEARNING DISABILITIES RESEARCH & PRACTICE, Issue 4 2009Evelyn S. Johnson Screening for early reading problems is a critical step in early intervention and prevention of later reading difficulties. Evaluative frameworks for determining the utility of a screening process are presented in the literature but have not been applied to many screening measures currently in use in numerous schools across the nation. In this study, the accuracy of several Dynamic Indicators of Basic Early Literacy Skills (DIBELS) subtests in predicting which students were at risk for reading failure in first grade was examined in a sample of 12,055 students in Florida. Findings indicate that the DIBELS Nonsense Word Fluency, Initial Sound Fluency, and Phoneme Segmentation Fluency measures show poor diagnostic utility in predicting end of Grade 1 reading performance. DIBELS Oral Reading Fluency in fall of Grade 1 had higher classification accuracy than other DIBELS measures, but when compared to the classification accuracy obtained by assuming that no student had a disability, suggests the need to reevaluate the use of classification accuracy as a way to evaluate screening measures without discussion of base rates. Additionally, when cut scores on the screening tools were set to capture 90 percent of all students at risk for reading problems, a high number of false positives were identified. Finally, different cut scores were needed for different subgroups, such as English Language Learners. Implications for research and practice are discussed. [source] Microfabricated devices: A new sample introduction approach to mass spectrometryMASS SPECTROMETRY REVIEWS, Issue 4 2006Iulia M. Lazar Abstract Instrument miniaturization is one way of addressing the issues of sensitivity, speed, throughput, and cost of analysis in DNA diagnostics, proteomics, and related biotechnology areas. Microfluidics is of special interest for handling very small sample amounts, with minimal concerns related to sample loss and cross-contamination, problems typical for standard fluidic manipulations. Furthermore, the small footprint of these microfabricated structures leads to instrument designs suitable for high-density, parallel sample processing, and high-throughput analyses. In addition to miniaturized systems designed with optical or electrochemical detection, microfluidic devices interfaced to mass spectrometry have also been demonstrated. Instruments for automated sample infusion analysis are now commercially available, and microdevices utilizing chromatographic or capillary electrophoresis separation techniques are under development. This review aims at documenting the technologies and applications of microfluidic mass spectrometry for the analysis of proteomic samples. © 2006 Wiley Periodicals, Inc., Mass Spec Rev 25:573,594, 2006 [source] Museums: Targets or Instruments of Cultural Policies?MUSEUM INTERNATIONAL, Issue 4 2006Patrick J. Boylan [source] Validity of the Kohlman Evaluation of Living Skills (KELS) with Israeli elderly individuals living in the communityOCCUPATIONAL THERAPY INTERNATIONAL, Issue 4 2002Tal Zimnavoda Faculty of Medicine Abstract The Kohlman Evaluation of Living Skills (KELS) was developed to evaluate Activities of Daily Living (ADL) and Instrumental ADL (IADL) in a psychiatric population. Later the KELS was assessed and adapted for a geriatric population. The purpose of this study was to determine the validity of the KELS with elderly individuals living in the community in Israel. The subjects included 92 elderly people living in the community, in protected housing facilities for the elderly, and those living in the community and attending day care. Instruments included the Mini-Mental State Examination (MMSE) to determine cognitive function, the Functional Independent Measure (FIM) to determine performance in ADL, and the Routine Task Inventory (RTI) as a measure of IADL to determine criterion validity. Results showed high correlations between the KELS and the RTI (r=0.895) and the FIM (r=0.70). The KELS was also found to be highly sensitive to the differences between all three groups, supporting construct validity. Furthermore, the KELS was found to be more sensitive to these differences than the other instruments used in the study. In conclusion, the results show the KELS to be valid and appropriate for use by occupational therapists with the Israeli elderly population, similar to the US population. The study's small sample size limits the generalizability of the findings. It is recommended that further research be done on the KELS with larger and more diverse elderly populations. Copyright © 2002 Whurr Publishers Ltd. [source] Exponential Tilting with Weak Instruments: Estimation and Testing,OXFORD BULLETIN OF ECONOMICS & STATISTICS, Issue 3 2010Mehmet Caner Abstract This article analyses exponential tilting estimator with weak instruments in a nonlinear framework. Our paper differs from the previous literature in the context of consistency proof. Tests that are robust to the identification problem are also analysed. These are Anderson,Rubin and Kleibergen types of test statistics. We also conduct a simulation study wherein we compare empirical likelihood and continuous updating-based tests with exponential tilting (ET)-based ones. The designs involve GARCH(1,1) and contaminated structural errors. We find that ET-based Kleibergen test has the best size among these competitors. [source] Comparing the Psychometric Properties of the Checklist of Nonverbal Pain Behaviors (CNPI) and the Pain Assessment in Advanced Dementia (PAIN-AD) InstrumentsPAIN MEDICINE, Issue 3 2010FAAN, Mary Ersek PhD Abstract Objective., To examine and compare the psychometric properties of two common observational pain assessment tools used in persons with dementia. Design., In a cross-sectional descriptive study nursing home (NH) residents were videotaped at rest and during a structured movement procedure. Following one training session and one practice session, two trained graduate nursing research assistants independently scored the tapes using the two pain observation tools. Setting., Fourteen NHs in Western Washington State participating in a randomized controlled trial of an intervention to enhance pain assessment and management. Participants., Sixty participants with moderate to severe pain were identified by nursing staff or chosen based on the pain items from the most recent Minimum Data Set assessment. Measures., Checklist of Nonverbal Pain Indicators (CNPI) and the Pain Assessment in Advanced Dementia (PAINAD), demographic and pain-related data (Minimum Data Set), nursing assistant reports of participants' usual pain intensity, and Pittsburgh Agitation Scale. Results., Internal consistency for both tools was good except for the CNPI at rest for one rater. Inter-rater reliability for pain presence was fair (K = 0.25 for CNPI with movement; K = 0.31 for PAINAD at rest) to moderate (K = 0.43 for CNPI at rest; K = 0.54 for PAINAD with movement). There were significant differences in mean CNPI and PAINAD scores at rest and during movement, providing support for construct validity. However, both tools demonstrated marked floor effects, particularly when participants were at rest. Conclusions., Despite earlier studies supporting the reliability and validity of the CNPI and the PAINAD, findings from the current study indicate that these measures warrant further study with clinical users, should be used cautiously both in research and clinical settings and only as part of a comprehensive approach to pain assessment. [source] Addiction-Related Assessment Tools and Pain Management: Instruments for Screening, Treatment Planning, and Monitoring CompliancePAIN MEDICINE, Issue 2008Steven D. Passik PhD ABSTRACT Objective., To review and critique the various assessment tools currently available to pain clinicians for assessing opioid use and abuse in patients with chronic noncancer pain to allow pain clinicians to make informed selections for their practices. Methods., A literature search on PubMed was conducted in June 2006 using the search terms opioid plus screening or assessment with or without the additional term risk, and opioid-related disorders/prevention and control in order to identify clinical studies published in English over the previous 10 years. Additional studies were identified using the PubMed link feature and Google. When abstracts described or referred to a tool for opioid abuse screening, the corresponding publication was acquired and reviewed for relevance to the pain treatment setting. Results., Forty-three publications were selected for review from the abstracts identified, and 19 were rejected because they did not describe a specific tool or provide adequate information regarding the screening tool used. The remaining 24 publications described relevant screening tools for opioid abuse risk and were reviewed. Conclusions., A variety of self-administered and physician-administered tools differing in their psychometrics and intended uses have been developed, but not all have been validated for use in chronic pain patients seen in a clinical practice setting. Some tools assess abuse potential in patients being considered for opioid therapy, whereas other tools screen for the presence of substance abuse. By recognizing the psychometrics of each tool, clinicians can select the ones most appropriate for their patient population and screening needs. [source] Frost boils and soil ice content: field observationsPERMAFROST AND PERIGLACIAL PROCESSES, Issue 4 2006P. P. Overduin Abstract Our aim is to measure and explain the seasonal changes in soil ice content in the frost boils of Galbraith Lake, Alaska. Instruments were installed in a frost boil to monitor the ground surface position and soil state over a period of 4 years. By comparing the subsidence and thaw rates, we calculate the soil ice content as a function of depth. Measured soil temperatures, liquid water contents and bulk apparent thermal conductivities are used to estimate latent heat production and release in the soil. The frost boil heaves during freezing and settles during thaw while the surrounding tundra heaves negligibly, but subsides measurably. Despite large changes in freezing rates from year to year, total heave and its distribution across the frost boil are similar between years. Winter air temperature and snow depth influence the freezing rate and ice distribution as a function of depth, but not the overall heave. This suggests that heave is controlled by water availability rather than the rate of heat removal from the soil. Areal ground subsidence rates between 2 and 5,cm/yr are due to the disappearance of ice at the base of the active layer, raising the possibility of ongoing thermokarst expansion around Galbraith Lake. Copyright © 2006 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||