Showing papers by "Lehigh University published in 1998"

Adhd Rating Scale-IV: Checklists, Norms, and Clinical Interpretation

Abstract: Introduction to ADHD Rating Scales. Factor Analysis. Standardization and Normative Data. Reliability and Validity. Interpretation and Use of Scales for Diagnostic and Screening Purposes. Interpretation and Use of Scales for Evaluating Treatment Outcome. Appendix: Rating Scales And Scoring Sheets. ADHD Rating Scale-IV: Home Version. ADHD Rating Scale-IV: Home Version (Spanish). Scoring Summary Sheet (Boys). Scoring Summary Sheet (Girls). ADHD Rating Scale-IV: School Version Scoring Summary Sheet (Boys). Scoring Summary Sheet (Girls).

Parent Ratings of Attention-Deficit/Hyperactivity Disorder Symptoms: Factor Structure and Normative Data

Abstract: Changes in the diagnostic criteria for attention-deficit/hyperactivity disorder (ADHD) have necessitated the creation of new measures for clinical assessment. The factor structure of a parent rating scale containing the 18 symptoms of ADHD was examined in this study. Factor analyses and assessment of differences in ADHD ratings across sex, age, and ethnic group were conducted using a sample of 4666 participants ranging in age from 4 to 20 years old who attended kindergarten through 12th grade in 22 school districts across the United States. Two factors (Inattention and Hyperactivity–Impulsivity) were derived and normative data for a nationally representative sample are presented. A higher frequency of ADHD symptoms was found for boys, younger children, and African-American participants. Potential uses of this scale in clinical practice and research are discussed.

In Situ Spectroscopic Investigation of Molecular Structures of Highly Dispersed Vanadium Oxide on Silica under Various Conditions

Abstract: The molecularly dispersed V2O5/SiO2 supported oxides were prepared by the incipient wetness impregnation of 2-propanol solutions of V-isopropoxide. The experimental maximum dispersion of surface vanadium oxide species on SiO2 was achieved at ∼12 wt % V2O5 (∼2.6 V atoms/nm2). The surface structures of the molecularly dispersed V2O5/SiO2 samples under various conditions were extensively investigated by in situ Raman, UV−vis−NIR DRS and XANES spectroscopies. The combined characterization techniques revealed that in the dehydrated state only isolated VO4 species are present on the silica surface up to monolayer coverage. Interestingly, the three-member siloxane rings on the silica surface appear to be the most favorable sites for anchoring the isolated, three-legged (SiO)3VO species. Hydration dramatically changes the molecular structure of the surface vanadium oxide species. The specific structure of the hydrated surface vanadium oxide species is dependent on the degree of hydration. The molecular structure ...

Oxidation of sulfur dioxide to sulfur trioxide over supported vanadia catalysts

Abstract: The objectives of this research are to establish the fundamental kinetics and mechanism of sulfur dioxide oxidation over supported vanadia catalysts and use these insights to facilitate the design of SCR DeNOx catalysts with minimal sulfur dioxide oxidation activity. A series of supported vanadia catalysts were prepared on various metal-oxide supports: ceria, zirconia, titania, alumina and silica. Raman spectroscopy was used to determine the coordination of surface species. At low vanadia loadings, vanadia preferentially exists on oxide support surfaces as isolated tetrahedrally coordinated (M‐O)3V a5 aO species. At higher vanadia loadings, the isolated (M‐O)3V a5 aO species polymerize on the oxide support surface breaking two V‐O‐M bonds and forming two V‐O‐V bridging bonds. The turnover frequency for sulfur dioxide oxidation was very low, 10 ˇ4 to 10 ˇ6 s ˇ1 at 4008C, and was independent of vanadia coverage suggesting that only one vanadia site is required for the oxidation reaction. As the support was varied, sulfur dioxide oxidation activity of the supported vanadia catalysts varied by one order of magnitude (Ce>Zr, Ti>Al>Si). The basicity of the bridging V‐O‐M oxygen appears to be responsible for influencing the adsorption and subsequent oxidation of the acidic sulfur dioxide molecule. Over the range of conditions studied, the rate of sulfur dioxide oxidation is zero-order in oxygen, first-order in sulfur dioxide and inhibited by sulfur trioxide. The turnover frequency for sulfur dioxide oxidation over WO3/TiO2 was an order of magnitude lower than that found for V2O5/TiO2, and no redox synergism between the surface vanadia and tungsten oxide species was evident for a ternary V2O5/ WO3/TiO2 catalyst. This suggests that WO3 promoted catalysts may be suitable for low-temperature SCR where minimal sulfur dioxide oxidation activity is required. # 1998 Elsevier Science B.V. All rights reserved.

Peer tutoring for children with attention deficit hyperactivity disorder: effects on classroom behavior and academic performance.

Abstract: We investigated the effects of classwide peer tutoring (CWPT) on the classroom behavior and academic performance of students with attention deficit hyperactivity disorder (ADHD). Typical instructional activities were contrasted with CWPT for 18 children with ADHD and 10 peer comparison students attending first- through fifth-grade general education classes. CWPT led to increases in active engagement in academic tasks along with reductions in off-task behavior for most participants. Of students with ADHD, 50% exhibited improvements in academic performance in math or spelling during CWPT conditions, as measured by a treatment success index. Participating teachers and students reported a high level of satisfaction with intervention procedures. Our results suggest that peer tutoring appears to be an effective strategy for addressing the academic and behavioral difficulties associated with ADHD in general education settings.

When All Else Fails: Ethnic Population Transfers and Partitions in the Twentieth Century

Abstract: ~ U n t i l recently, there has been a near consensus among policymakers and scholars that the objective of ethnic conflict management should be to support and preserve integrated, multiethnic societies. In the last few years, however, the idea that separating the warring populations may be the best solution to many of the most intense ethnic conflicts has been gaining ground. Events in Bosnia have supported this trend, as observers note that the more the warring groups have separated, the more peaceful their relations have become, while proposals to thoroughly reintegrate them command less and less support.' In addition, a growing body of scholarship that focuses on the role of intergroup security dilemmas in ethnic conflicts argues that intermixed population settlement patterns can promote escalation of violence, implying that separation of warring groups may dampen conflict2

A transmission electron microscopy study of constituent-particle-induced corrosion in 7075-T6 and 2024-T3 aluminum alloys

Abstract: To better understand particle-induced pitting corrosion in aluminum alloys, thin foil specimens of 7075-T6 and 2024-T3 aluminum alloys, with identified constituent particles, were immersed in aerated 0.5M NaCl solution and then examined by transmission electron microscopy (TEM). The results clearly showed matrix dissolution around the iron- and manganese-containing particles (such as Al23CuFe4), as well as the Al2Cu particles. While Al2CuMg particles tended to dissolve relative to the matrix, limited local dissolution of the matrix was also observed around these particles. These results are consistent with scanning electron microscopy (SEM) observations of pitting corrosion and are discussed in terms of the electrochemical characteristics of the particles and the matrix.

A Meta-Analysis and Review of Sight Word Research and Its Implications for Teaching Functional Reading to Individuals with Moderate and Severe Disabilities:

Abstract: We conducted a comprehensive review of sight word research with individuals with disabilities since 1980 with the aim of determining the overall effectiveness of sight word research and its specific impact on individuals with moderate and severe disabilities. The review also identified innovations in instructional strategies developed since prior reviews. A total of 48 studies was reviewed. Most studies were conducted with individuals with moderate mental retardation, and the overall mean IQ for research participants was 55; however, other disability groups and levels were represented. Most studies were conducted with elementary school students, but a wide age range was represented, including adults. A meta-analysis using the percentage of nonoverlapping data points (PND) revealed that sight word instruction has been highly effective across individuals for people with moderate and severe disabilities. New strategies have included giving instructive feedback for additional learning, applying constant time ...

Conditional Market Timing with Benchmark Investors

Abstract: This paper tests models of mutual fund market timing that (1) allow the manager's utility function to depend on returns in excess of a benchmark; (2) distinguish timing based on lagged, publicly available information variables from timing based on finer information; and (3) simultaneously estimate the parameters which describe the public information environment, the risk aversion and the precision of the fund's market timing signal. Using a sample of more than 400 U.S. mutual funds for 1976-94, the estimates imply that mutual funds behave as risk averse, benchmark investors. Conditioning on public information variables improves the model specification, and after controlling for the public information we find no evidence that funds have significant market timing ability.

What Is the Offense-Defense Balance and Can We Measure It?

Abstract: Offense-defense theory offers an optimistic view of international politics based on the argument that war can be prevented if defense gains an advantage over offense. It also argues that an effective arms control can reduce the risk of arms races and war. The theory has been useful in foreign policy analysis and in international relations scholarship since it is used to explain theoretical and policy issues and the causes of World War I and ethnic and civil wars and to predict post-Cold War Europe political relations.

Reliability and Validity of Parent and Teacher Ratings of Attention-Deficit/Hyperactivity Disorder Symptoms:

Abstract: The reliability and criterion-related validity of the Home and School versions of the AD/HD Rating Scale-IV were evaluated in a nonreferred sample of 71 students. Parent and teacher rat-ings were obtained 4 weeks apart at a time contemporaneous with observations of classroom behavior and academic productivity. Results indicated adequate levels of internal consistency, test-retest reliability, and cross-informant agreement for both parent and teacher ratings. Teacher ratings were significantly correlated with classroom observational data, and parent ratings were primarily related to behavior ratings. The discriminant validity of these scales also was examined in a sample of 92 clinic- referred children. Both the Home and School versions of the AD/HD Rating Scale-IV were found to discriminate significantly between children with and without AD/HD. The AD/HD Rating Scale-IV appears to have adequate psychometric properties for the screening and assessment of AD/HD.

Assessing culturally different students for attention deficit hyperactivity disorder using behavior rating scales.

Abstract: Behavior rating scales are commonly used in the assessment of attention deficit-hyperactivity disorder (ADHD). However, there is little information available concerning the extent to which scales are valid with culturally different students. This study explored the use of the ADHD-IV Rating Scale School Version with male Caucasian (CA) and African American (AA) students from ages 5 to 18 years. Teachers rated AA students higher on all symptoms across all age groups. LISREL analysis indicated that scale does not perform identically across groups. This was supported by the results of multidimensional scaling with suggested that there is a different relation between items across groups. Implications for research and practice are discussed.

Effects of mathematical word problem solving by students at risk or with mild disabilities

Abstract: The differential effects of 2 instructional strategies, an explicit schema-based strategy and a traditional basal strategy, on the acquisition, maintenance, and generalization of mathematical word problem solving were examined. Thirty-four elementary-aged students with mild disabilities or at risk for mathematics failure were randomly assigned to each of the 2 treatment conditions (schema and traditional). Results indicated that both groups' performance increased from the pretest to the posttest. All students were able to maintain their use of word problem-solving skills and generalized the strategy effects to novel word problems. However, the differences between groups on the posttest, delayed posttest, and generalization test were statistically significant, favoring the schema group. In addition, scores on the immediate posttest (77% correct) and delayed posttest (81% correct) for the schema group approached those of a normative sample of 3rd graders (M = 82% correct).

Self-trapping of dark incoherent light beams

Abstract: “Dark beams” are nonuniform optical beams that contain either a one-dimensional (1D) dark stripe or a two-dimensional (2D) dark hole resulting from a phase singularity or an amplitude depression in their optical field. Thus far, self-trapped dark beams (dark solitons) have been observed using coherent light only. Here, self-trapped dark incoherent light beams (self-trapped dark incoherent wavepackets) were observed. Both dark stripes and dark holes nested in a broad partially spatially incoherent wavefront were self-trapped to form dark solitons in a host photorefractive medium. These self-trapped 1D and 2D dark beams induced refractive-index changes akin to planar and circular dielectric waveguides. The experiments introduce the possibility of controlling high-power coherent laser beams with low-power incoherent light sources such as light emitting diodes.

Classroom-based functional and adjunctive assessments: proactive approaches to intervention selection for adolescents with attention deficit hyperactivity disorder

Abstract: The present investigation evaluated the utility of classroom-based functional and adjunctive assessments of problem behaviors for 2 adolescents who met diagnostic criteria for attention deficit hyperactivity disorder (ADHD) and comorbid oppositional defiant disorder (ODD). For children with ADHD-ODD, environmental classroom variables, when systematically manipulated by teachers, were related to the occurrence and nonoccurrence of problem behaviors. Classroom interventions derived from information that was obtained during functional and adjunctive assessments and from subsequent analyses resulted in substantial reductions in problem behaviors. Teacher and student consumer satisfaction ratings indicated that the interventions were effective and feasible in the classroom setting.

Androgen receptor in mouse brain: sex differences and similarities in autoregulation.

Abstract: The androgen receptor (AR) is generally considered an autoregulated protein However, studies in brain have produced mixed results regarding sex differences, which should be present given the higher endogenous levels of androgens in males, and the effects of gonadectomy, which presumably should lead to a loss of AR Resolving these issues is a necessary step in developing a model of AR regulation in the central nervous system and, more broadly, in determining how regulation of this receptor may mediate neural target tissue responsiveness to androgen To further investigate these issues, the distribution, density, and regulation of neural AR were compared among male and female mice that were intact, gonadectomized, or gonadectomized and given testosterone propionate (TP) through immunocytochemical and Western blot analyses Four brain areas that have been linked to the regulation of male-typical behavior were evaluated: bed nucleus of the stria terminalis, posterior aspect, medial preoptic area, and dorsal and ventral aspects of the lateral septum In the immunocytochemical study, integrated particle density, which reflects the average intensity of AR staining, was assessed among the six groups 24 h after surgery using PG-21, a peptide-based AR antiserum Major findings included regional differences in the intensity of immunostaining; a robust sexual dimorphism in each region, with males exhibiting more intense staining than females; a loss of AR in both sexes after gonadectomy, with more dramatic changes evident in males; and significant up-regulation of AR in response to TP that was equivalent in both sexes The Western blot analyses of AR in limbic system extracts prepared from the six groups showed a pattern of differences that mirrored the immunocytochemical results, indicating that PG-21 recognized both liganded and unliganded AR In addition, a dose-response study, in which gonadectomized males and females were administered from 25-1000 microg TP, demonstrated a significant linear trend in up-regulation of AR in both males and females, with no sexual dimorphism in the response to hormone treatment These results demonstrate that the regulation of AR in both male and female neural tissue is comparable and that the critical determinant of AR expression is the presence or absence of androgen

Solidification of nb-bearing superalloys : Part I. Reaction sequences

Abstract: The solidification reaction sequences of experimental superalloys containing systematic variations in Fe, Nb, Si, and C were studied using differential thermal analysis (DTA) and microstructural characterization techniques. The reaction sequences responsible for microstructural development were found to be similar to those expected in the Ni-Nb-C ternary system and commercial superalloys of comparable composition. The solute-rich interdendritic liquid generally exhibited two eutectic-type reactions at the terminal stages of solidification: L → (γ+NbC) and L → (γ+Laves). The Ni-base alloys with a high C/Nb ratio represented the only exception to this general solidification sequence. This group of alloys terminated solidification with the L → (γ + NbC) reaction and did not exhibit the γ/Laves constituent. At similar levels of solute elements (Nb, Si, and C), the Fe-base alloys always formed more of the γ/Laves eutectic-type constituent than the corresponding Ni-base alloys. Silicon additions also increased the amount of the γ/Laves constituent that formed in the assolidified microstructure, while C additions promoted formation of γ/NbC. The influence of Nb was dependent on the C content of the alloy. When the C content was low, Nb additions generally promoted formation of γ/Laves, while Nb additions to alloys with high C led to formation of the γ/NbC constituent. The results of this work are combined with quantitative analyses for developing γ-Nb-C pseudoternary solidification diagrams in a companion article.

Glaciohydraulic supercooling: A freeze-on mechanism to create stratified, debris-rich basal ice: II. Theory

Abstract: Simple theory supports field observations (Lawson and others, 1998) that subglacial water flow out of overdeepenings can cause accretion of layered, debris-bearing ice to the bases of glaciers. The large meltwater flux into a temperate glacier at the onset of summer melting can cause rapid water flow through expanded basal cavities or other flow paths. If that flow ascends a sufficiently steep slope out of an overdeepening, the water will supercool as the pressure-melting point rises, and basal-ice accretion will occur. Diurnal, occasional or annual fluctuations in water discharge will cause variations in accretion rate, debris content of accreted ice or subsequent diagenesis, producing layers. Under appropriate conditions, net accretion of debris-bearing basal ice will allow debris fluxes that are significant in the glacier sediment budget.

An analytical electron microscopy study of constituent particles in commercial 7075-T6 and 2024-T3 alloys

Abstract: To better understand the role of constituent particles in pitting corrosion, analytical electron microscopic studies were performed on the constituent particles in commercial 7075-T6 and 2024-T3 alloys. Five phases, namely, Al23CuFe4 and amorphous SiO2 in 7075-T6 and Al2CuMg, Al2Cu, and (Fe,Mn) x Si(Al,Cu) y in 2024-T3, were identified. The crystal structure and chemistry of the Al23CuFe4, Al2CuMg, and Al2Cu phases in these alloys are in good agreement with the published data. Small deviations from their stoichiometric compositions were observed and are attributed to the influence of alloy composition on the phase chemistry. For the (Fe,Mn) x Si(Al,Cu) y (approximately, x=3 and y=11) phase, a rhombohedral structure, with lattice parameter a=b=c=1.598 nm and α=β=γ=75 deg, was identified and is believed to be a modified form of either Al8Fe2Si or Al10Mn3Si. Information from this study provided technical support for studying the electrochemical interactions between the individual particles (or phases) and the matrix. The corrosion results are reported in a companion article.

In-Situ Monitoring of Pitting Corrosion in Aluminum Alloy 2024

Abstract: An in-situ monitoring method was used to observe the initiation sites and the processes of pitting corrosion in aluminum alloy 2024-T3 (UNS A92024) in real time. These observations complemented more detailed information about composition and distribution of constituent particles, pre- and post-corrosion surface morphology, and the internal morphology of corrosion pits. In-situ observations provided a comprehensive view of the development of localized corrosion in real time. Results confirmed the importance of intermetallic constituent particles in promoting initiation and growth of pits in aluminum alloys. Heterogeneous distribution of these particles served to define the location and extent (or severity) of pitting. A conceptual model was proposed as a framework for continued research. The formation of occluded cells under corrosion product domes over severe pits was observed. This formation will be incorporated into an overall reconsideration and modeling of the processes of pitting corrosion o...

Air Oxidation of Self-Assembled Monolayers on Polycrystalline Gold: The Role of the Gold Substrate

Abstract: Alkanethiolates in self-assembled monolayers on gold oxidize in air, in the dark, to form sulfinates and sulfonates. The kinetics of oxidation, however, vary depending on the morphology of the underlying gold, with the rate of oxidation increasing dramatically with a decrease in the size of the grains and the amount of Au(111) on the surface. This difference in kinetics of oxidation is sufficiently great that it may provide insight into discrepancies among previous reports in the literature regarding the inertness of these SAMs in air. The oxidized products also desorb readily, and these species decompose under prolonged X-ray irradiation in ultrahigh vacuum.

Solidification of Nb-bearing superalloys: Part II. Pseudoternary solidification surfaces

Abstract: Equilibrium distribution coefficients and pseudoternary solidification surfaces for experimental superalloys containing systematic variations in Fe, Nb, Si, and C were determined using quenching experiments and microstructural characterization techniques. In agreement with previous results, the distribution coefficient, k, for Nb and Si was less than unity, while the “solvent” elements (Fe, Ni, and Cr) exhibited little tendency for segregation (k ≈ 1). The current data were combined with previous results to show that an interactive effect between kNb and nominal Fe content exists, where the value of kNb decreases from 0.54 to 0.25 as the Fe content is increased from ≈2 wt pct to ≈47 wt pct. This behavior is the major factor contributing to formation of relatively high amounts of eutectic-type constituents observed in Fe-rich alloys. Pseudoternary γ-Nb-C solidification surfaces, modeled after the liquidus projection in the Ni-Nb-C ternary system, were proposed. The Nb compositions, which partially define the diagrams, were verified by comparison of calculated amounts of eutectic-type constituents (via the Scheil equation) and those measured experimentally, and good agreement was found. The corresponding C contents needed to fully define the diagrams were estimated from knowledge of the primary solidification path and k values for Nb and C.

Reducing Disruptive Behavior in General Education Classrooms: The Use of Self-Management Strategies.

Abstract: The use of a self-management strategy in a general education classroom to decrease the disruptive behavior of three elementary school students with ADHD or ODD was investigated. A multiple-probe de...