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The Composition Of Normative Groups And Diagnostic Decision Making: Shooting Ourselves In The Foot
Purpose: The normative group of a norm-referenced test is intended to provide a basis for interpreting test scores. However, the composition of the normative group may facilitate or impede different types of diagnostic interpretations. This article considers who should be included in a normative sample and how-this decision must be made relative to the purpose for which a test is intended. Method: The way in which the composition of the normative sample affects classification accuracy is demonstrated through a test review followed by a simulation study. The test review examined the descriptions of the normative group in a sample of 32 child language tests. The mean performance reported in the test manual for the sample of language impaired children was compared with the sample's norms, which either included or excluded children with language impairment. For the simulation, 2 contrasting normative procedures were modeled. The first procedure included a mixed group of representative cases (language impaired and normal cases). The second procedure excluded the language impaired cases from the norm. Results: Both the data obtained from test manuals and the data simulation based on population characteristics supported our claim that use of mixed normative groups decreases the ability to accurately identify language impairment. Tests that used mixed norms had smaller differences between the normative and language impaired groups in comparison with tests that excluded children with impairment within the normative sample. The simulation demonstrated mixed norms that lowered the group mean and increased the standard deviation, resulting in decreased classification accuracy. Conclusions: When the purpose of testing is to identify children with impaired language skills, including children with language impairment in the normative sample can reduce identification accuracy.Communication Sciences and Disorder
Construction and Calibration of a Streaked Optical Spectrometer for Shock Temperature
Here we describe the implementation and calibration of a streaked visible
spectrometer (SVS) for optical pyrometry and emission/absorption spectroscopy
on light gas gun platforms in the UC Davis Shock Compression Laboratory. The
diagnostic consists of an optical streak camera coupled to a spectrometer to
provide temporally and spectrally-resolved records of visible emission from
dynamically-compressed materials. Fiber optic coupling to the sample enables a
small diagnostic footprint on the target face and flexibility of operation on
multiple launch systems without the need for open optics. We present the
details of calibration (time, wavelength and spectral radiance) for absolute
temperature determination and present benchmark measurements of system
performance.Comment: 6 pages, 3 figures Davies, E., et al. (accepted). In J. Lane, T.
Germann, and M. Armstrong (Eds.), 21st Biennial APS Conference on Shock
Compression of Condensed Matter (SCCM19). AIP Publishin
Post-Parham Remedies: The Involuntary Commitment of Minors in Virginia After Parham v. J.R.
This case raises the most important question of every child\u27s constitutional right to liberty, not only the liberty that includes freedom from bodily restraint [citation omitted], but also the liberty that includes the freedom of an ordinary, every-day child in these United States of America-the freedom to live with mothers, fathers, brothers, and sisters in whatever the family abode may be; the freedom to be loved and to be spanked; the freedom to go in and oat the door, to run and play, to laugh and cry, to fight and fuss, to stand up and fall down, to play childish games; the freedom to go to school and to frolic with school mates; to go to Sunday school and church; the freedom to watch and listen or not to watch and listen to television; the freedom to buy candy at the corner store, the freedom to be a normal child in a normal household cared for by normal parents
Ethanol Marketing and Input Procurement Practices of U.S. Ethanol Producers: 2008 Survey Results
A mail survey was used to collect information about input procurement and ethanol and co-product marketing practices from 60 U.S. ethanol production facilities. Data were used to answer questions about the conduct or behavior of ethanol producers. It was anticipated that firm conduct or behavior would be fairly homogeneous because the ethanol industry was in Stage II of the industry life-cycle, and societal support for ethanol production resulted in large volumes of publicly available information about technology and markets. Age of facility, size of facility, and type of ownership jointly explained a limited number of differences in responses across ethanol facilities, thus supporting the concept of fairly homogeneous conduct or behavior.entry timing, ethanol, farmer-owned cooperatives, industry life-cycle, Agribusiness, Resource /Energy Economics and Policy, Q11, Q42,
Nonlinear dynamics of mode-locking optical fiber ring lasers
We consider a model of a mode-locked fiber ring laser for which the evolution of a propagating pulse in a birefringent optical fiber is periodically perturbed by rotation of the polarization state owing to the presence of a passive polarizer. The stable modes of operation of this laser that correspond to pulse trains with uniform amplitudes are fully classified. Four parameters, i.e., polarization, phase, amplitude, and chirp, are essential for an understanding of the resultant pulse-train uniformity. A reduced set of four coupled nonlinear differential equations that describe the leading-order pulse dynamics is found by use of the variational nature of the governing equations. Pulse-train uniformity is achieved in three parameter regimes in which the amplitude and the chirp decouple from the polarization and the phase. Alignment of the polarizer either near the slow or the fast axis of the fiber is sufficient to establish this stable mode locking
Examination of Factors Influencing Crop Insurance Purchase Decisions of Illinois Farmers
Farm Management, Risk and Uncertainty,
Crop Insurance Purchase Decisions: A Study of Northern Illinois Farmers
When selecting crop insurance coverage, farmers must consider multiple factors. The importance associated with factors that are considered when making crop insurance decisions varies among individual farmers. As available crop insurance options increase, selecting the appropriate coverage becomes a more complicated process. The prevalence of crop insurance participation and the existence of multiple selection criteria also makes understanding participant decisions more difficult. This paper provides findings of a mail survey conducted among farmers in northern Illinois. Mainly, this paper examines factors influencing farmers’ crop insurance purchase decisions, types of coverage purchased, and farmers’ risk attitudes.Crop Production/Industries,
Risk Management Strategies of Illinois Farmers
Farm Management, Risk and Uncertainty,
The Effects of Concentric Ring Electrode Electrical Stimulation on Rat Skin
Surface electrodes are commonly used electrodes clinically, in applications such as functional electrical stimulation for the restoration of motor functions, pain relief, transcutaneous electrical nerve stimulation, electrocardiographic monitoring, defibrillation, surface cardiac pacing, and advanced drug delivery systems. Common to these applications are occasional reports of pain, tissue damage, rash, or burns on the skin at the point where electrodes are placed. In this study, we quantitatively analyzed the effects of acute noninvasive electrical stimulation from concentric ring electrodes (CRE) to determine the maximum safe current limit. We developed a three-dimensional multi-layer model and calculated the temperature profile under the CRE and the corresponding energy density with electrical-thermal coupled field analysis. Infrared thermography was used to measure skin temperature during electrical stimulation to verify the computer simulations. We also performed histological analysis to study cell morphology and characterize any resulting tissue damage. The simulation results are accurate for low energy density distributions. It can also be concluded that as long as the specified energy density applied is kept below 0.92 (A2/cm4·s−1), the maximum temperature will remain within the safe limits. Future work should focus on the effects of the electrode paste
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