cssi/SciSciGPT-SciSciNet huggingface dataset:
Exploratory inspection—a user-based learning method for improving open source software usability

The increasingly widespread use of open source software (OSS) is an indication of its success. However, as a software development model OSS still has shortcomings that need to be resolved. In particular, the question of usability and its improvement in an OSS context remains a significant ongoing issue that demands further investigation. This is especially so given the unique manner in which OSS diverges from traditional software development models. Current experience with OSS does not favor the existence of a positive relation between the standard OSS development paradigm and good usability practice. We believe that addressing the inadequacy of usability expertise in the OSS community will improve the quality of its products and enhance their competitiveness. Motivated by the unique user-driven character of the OSS model, we propose an exploratory method for inspection which is intended to assist OSS users in contributing to open source usability inspection. This method provides an effective adaptation of the ‘learning-by-doing’ approach to the domain of usability inspection. This is accomplished by innovatively applying usability patterns to guide usability exploration, incorporating strategies for ‘outlining knowledge’ and ‘exploration freedom’ and implementing both techniques in an integrated inspection environment. The results of an experiment involving a group of OSS users inspecting an open source project called dotproject demonstrate that this method outperforms traditional heuristics-based inspection. The paper also considers the applicability of the usability method and tool developed to usability improvement in the context of traditional proprietary development. Copyright © 2010 John Wiley & Sons, Ltd. (We propose an exploratory method for inspection which is intended to assist OSS users in contributing to open source usability inspection. This method provides an effective adaptation of the ‘learning-by-doing’ approach to the domain of usability inspection. This is accomplished by innovatively applying usability patterns to guide usability exploration, incorporating two strategies in an integrated inspection environment. The results of an experiment involving a group of OSS users demonstrate that this method outperforms the traditional heuristics-based inspection. Copyright © 2010 John Wiley & Sons, Ltd.)
Uniqueness for formally determined inverse boundary value problems

Abstract In this paper, we study the inverse conductivity problem in two dimensions. This problem is reduced to a formally determined inverse boundary value problem for the Schrodinger equation. Some recent generic uniqueness results for the inverse problems will be discussed and a new continuous dependence result presented.
Moduli of rupture of layered dental ceramics.

Objective. The purpose of this study was to determine the moduli of rupture of layered beams made of strong core materials veneered with weaker conventional feldspathic porcelain. Methods. A three-point flexural test, and formulae derived especially for this purpose were used. Two systems were investigated. The first consisted ov Vitadur N (Vita Zahnfabrik), a conventional feldspathic porcelain; and Dicor MGC (L.D. Caulk), a machinable glass ceramic. The second consisted of Vitadur N and In-Ceram (Vita Zahnfabrik), a strong reinforced aluminous porcelain. Results: Two-way ANOVA and Tukey tests were used to evaluate the effect of numerous factors on the modulus of rupture. The results indicated that the material forming the tensile surface, the material forming the compressive surface and their interaction had a highly significant effect on modulus of rupture (p < 0.05). The effect of the material forming the tensile surface on modulus of rupture was of much greater magnitude than that of the compressive surface. Theoretical curves describing effects of the layer's elastic moduli and thickness on the force-bearing capacity of model beams were plotted. These indicated that for a wide range of thickness ratios and for a wide variety of elastic modulus ratios, the tensile material dominates the force-bearing capacity of layered beams except when a very much lower modulus material forms the compressive layer. Significance. Layered prostheses made of strong cores veneered with weaker feldspathic porcelain may be prone to failure when the feldspathic surfaces are subjected to tensile force.
Transitions between cooperative and non-cooperative responding in the 'Pigeon's Dilemma'

Two pigeons played Iterated Prisoner's Dilemma (IPD) against a simulated opponent pre-programmed to play 'Tit-For-Tat' (TFT) and 'Random' (RND) strategies. Each pigeon received differential amounts of access to food following choices of either 'cooperate' or 'defect' on a trial. After 1000 trials against TFT and 500 trials against RND, results indicated that choice allocation was optimal when the birds played against RND but was sub-optimal when the birds played against TFT. In order to determine why the pigeons responded suboptimally against TFT, a trial-by-trial analysis of the data was conducted. The analysis revealed that once a pigeon had received the 'Sucker's' payoff (S), it was more likely to defect and receive the 'Temptation' payoff (T) than to cooperate and receive the 'Reward' (R) payoff. Local reinforcement contingencies appear to determine suboptimal responding against TFT in the iterated Pigeon's Dilemma.
ESTIMATING WAITING TIME IN A QUEUING SYSTEM

This study examines how customers joining a queuing system assess their waiting time in the system. Data obtained from an actual queuing system support the paradigm of Parkan and Warren [5] on the use of the observed number in the system in this assessment. It is concluded that customers overestimate mean service time but that this overestimation is not dependent on the number in the system.
Complementation Analysis on Virus-Fused Chinese Hamster Cells with Nutritional Markers

Cell fusion experiments have been carried out with Chinese hamster cell mutants with different nutritional growth requirements. Conditions have been devised in which approximately 1 to 2 percent of the cell population remaining after fusion are fused, hybrid cells. The all-or-none nature of the genetic markers employed and the extremely low reversion rates insure that no contamination of the hybrid population with parental forms occurs. Hybrids between glycine- and hypoxanthine-requiring mutants are prototrophic, which indicates that both mutations are recessive. Hybrids between a glycine-deficient mutant and a singlestep mutant which requires glycine, hypoxanthine, and thymidine are relieved of the glycine dependency, an indication that the two loci associated with glycine dependence are different. This mutation to the triple-supplement requirement as well as a proline deficiency were also shown to be recessive mutations. The system appears applicable to a variety of genetic problems.
Great expectations: A meta-analytic examination of optimism and hope

Abstract Optimism and hope—two psychological constructs reflecting positive expectations about one’s future—have garnered considerable research attention and each has been the subject of several narrative reviews. In the current meta-analysis, we examined the optimism–hope relationship and we examined several potential correlates and consequences of optimism and hope. Our results suggest that optimism and hope are distinguishable from each other. Furthermore, both are related to several indices of psychological and physical well-being and both are empirically distinguishable from other personality traits, such as the Five Factor Model characteristics and trait affectivity. We conclude by discussing directions for future research on optimism and hope.
A contextual classification method for recognizing land use patterns in high resolution remotely sensed data

Abstract This paper describes a CONtextual ANalysis procedure (CONAN) which is designed to recognize land use patterns in high resolution remotely sensed data by analysis of the local frequency distribution of scene components (i.e. ground cover type classes). The procedure was tested with randomly generated synthetic data developed to simulate the frequency distribution of cover type components for four land use classes. It was found that the accuracy in discriminating between the four test classes depends upon the size of the pixel neighborhood used to compute the component frequency distribution.
In-situ thin film stress measurement using high-stability portable holographic interferometer

A stress in thin film SiO2 was detected using high stability portable holographic interferometer. A stress relaxation phenomenon in this film thickness of 0.5 micrometers on Si wafer has been observed. This phenomenon does not exist in film with thickness of 1 micrometers . The advantages of the proposed measured technique and results are discussed.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Temporal and spatial variation in age-specific net migration in the United States.

As fertility differences in the United States diminish, population redistribution trends are increasingly dependent on migration. This research used newly developed county-level age-specific net migration estimates for the 1990s, supplemented with longitudinal age-specific migration data spanning the prior 40 years, to ascertain whether there are clear longitudinal trends in age-specific net migration and to determine if there is spatial clustering in the migration patterns. The analysis confirmed the continuation into the 1990s of distinct net migration “signature patterns” for most types of counties, although there was temporal variation in the overall volume of migration across the five decades. A spatial autocorrelation analysis revealed large, geographically contiguous regions of net in-migration (in particular, Florida and the Southwest) and geographically contiguous regions of net out-migration (the Great Plains, in particular) that persisted over time. Yet the patterns of spatial concentration and fragmentation over time in these migration data demonstrate the relevance of this “neighborhood” approach to understanding spatiotemporal change in migration.
A comparison of spatial clustering and cluster detection techniques for childhood leukemia incidence in Ohio, 1996 – 2003

Spatial cluster detection is an important tool in cancer surveillance to identify areas of elevated risk and to generate hypotheses about cancer etiology. There are many cluster detection methods used in spatial epidemiology to investigate suspicious groupings of cancer occurrences in regional count data and case-control data, where controls are sampled from the at-risk population. Numerous studies in the literature have focused on childhood leukemia because of its relatively large incidence among children compared with other malignant diseases and substantial public concern over elevated leukemia incidence. The main focus of this paper is an analysis of the spatial distribution of leukemia incidence among children from 0 to 14 years of age in Ohio from 1996–2003 using individual case data from the Ohio Cancer Incidence Surveillance System (OCISS). Specifically, we explore whether there is statistically significant global clustering and if there are statistically significant local clusters of individual leukemia cases in Ohio using numerous published methods of spatial cluster detection, including spatial point process summary methods, a nearest neighbor method, and a local rate scanning method. We use the K function, Cuzick and Edward's method, and the kernel intensity function to test for significant global clustering and the kernel intensity function and Kulldorff's spatial scan statistic in SaTScan to test for significant local clusters. We found some evidence, although inconclusive, of significant local clusters in childhood leukemia in Ohio, but no significant overall clustering. The findings from the local cluster detection analyses are not consistent for the different cluster detection techniques, where the spatial scan method in SaTScan does not find statistically significant local clusters, while the kernel intensity function method suggests statistically significant clusters in areas of central, southern, and eastern Ohio. The findings are consistent for the different tests of global clustering, where no significant clustering is demonstrated with any of the techniques when all age cases are considered together. This comparative study for childhood leukemia clustering and clusters in Ohio revealed several research issues in practical spatial cluster detection. Among them, flexibility in cluster shape detection should be an issue for consideration.
Groundwater controls ecological zonation of salt marsh macrophytes.

Ecological zonation of salt marsh macrophytes is strongly influenced by hydrologic factors, but these factors are poorly understood. We examined groundwater flow patterns through surficial sediments in two salt marshes in the southeastern United States to quantify hydrologic differences between distinct ecological zones. Both sites included tall- or medium-form Spartina alterniflora near the creek bank; short-form Spartina alterniflora in the mid-marsh; salt flats and Salicornia virginica in the high marsh; and Juncus roemarianus in brackish-to-fresh areas adjacent to uplands. Both sites had relatively small, sandy uplands and similar stratigraphy consisting of marsh muds overlying a deeper sand layer. We found significant hydrologic differences between the four ecological zones. In the zones colonized by S. alterniflora, the vertical flow direction oscillated with semi-diurnal tides. Net flow (14-day average) through the tall S. alterniflora zones was downward, whereas the short S. alterniflora zones inc...
A New Perspective on Peer‐Editing

This article describes the peer-editing behaviors of eight undergraduate students in a third-year Spanish composition and grammar review course. Data collected over four months through interviews, participant observation, artifact inventories, and questionnaires revealed a strong tendency among informants to define the peer-editing process in social and emotional terms, but did not support some of the previously held views regarding the effectiveness of the process. The author's findings challenge common beliefs about the effects that audience awareness and response may have on students' writing and students' attitude toward writing, and suggest implications for the classroom.
Rapid decreases in indigenous covalent DNA modifications (I-compounds) of male Fischer-344 rat liver DNA by diquat treatment.

I-compounds are indigenously appearing covalent DNA modifications that can be detected by 32P-postlabeling assay in tissues of normal animals without known exposure to any carcinogens or toxins. Although these compounds have not been structurally identified, indirect evidence from earlier work suggested the possibility of involvement of molecular fragments derived from lipid peroxides. Diquat is a herbicide that stimulates lipid peroxidation and massive intrahepatic oxidant stress through redox cycling-mediated generation of reactive oxygen species. In the present study, we examined the effects of diquat on hepatic I-compounds of male Fischer-344 rats. Two groups of rats, approximately 14 weeks and 8 weeks old, were given a hepatotoxic dose (0.1 mmol/kg) of diquat or equal volumes of saline, i.p. Two and 6 h later plasma alanine aminotransferase (ALT) activities were measured and hepatic DNA I-compound levels were examined by nuclease P1-enhanced 32P-postlabeling. Elevated ALT activities were observed in some animals in both groups, at both time points, but considerable inter-animal variation was seen. A total of 15–16 I-compound fractions were measured in control and in diquat-treated animals, but no extra spots indicative of treatment-induced adducts were detected. Despite the qualitative similarities, the quantities of individual I-compounds were markedly decreased at 2 h in diquat-treated animals of both age groups. In 14 week old rats the hepatic I-compound contents were decreased at 2 h by 22–59%, which was statstically significant (ANOVA, P < 0.05) for all of the 9 polar I-compound fractions and none of the non-polar fractions. Eleven I-spots from this group showed significant negative linear correlations (P < 0.05) with ALT values. In 8 week old rats treated with diquat a 22–43% depletion in I-compound contents was statistically significant for 4 of the 7 non-polar and 2 of the 8 polar adduct fractions, but there was no significant correlation of I-compound contents with ALT values at the 2 h time point. By 6 h most of the I-spot levels had returned to normal or above normal values in both groups of animals. While most I-spots from 14 week old rats did not correlate with ALT levels at 6 h, two I-spots displayed positive correlations in the 8 week group. Overall, the susceptibility to diquat-associated DNA alterations appeared to differ with age. Decreases in hepatic I-compound contents of diquat-treated Fischer-344 rats and the absence of additional I-compounds in these animals were not consistent with the hypothesis that I-compounds are derived from lipid peroxide fragments. However, the rapid but transient decrease in I-compound levels is notable because of similar trends previously observed during a number of procarcinogenic experimental manipulations.
Abnormal development in the mouse caused by chromosome unbalance

A line of mice, designated as the T1 stock, which has been derived from a single male whose father was X-rayed, is characterised by the production of about 4·6 per cent. of abnormal embryos, and of a somewhat smaller percentage of abnormal young at term. The abnormality consists of a failure of the neural groove to close throughout a portion of its anterior end. In most of the defective embryos the diencephalon, mesencephalon, and metencephalon are open, in a few only the diencephalon and mesencephalon, but no two embryos are exactly alike in the extent of the defect. Apart from the open condition of the brain roof, most of the parts of the brain have formed in a normal or almost normal fashion, but in some of the embryos curious aberrations in the development of the telencephalon or of the plexuses or of other brain regions are to be found. In the embryos at term, the roof of the cranium is lacking, though the roofing bones are represented at least by centres of ossification at the sides of the head. The abnormal embryos are produced not only when two individuals of the T1 stock are mated together, but also when certain individuals of this stock are mated to normals from untreated stocks. This rules out the possibility that they are the result of the segregation of a simple recessive gene. They probably are caused by the segregation of an X-ray-induced translocation. Mice heterozygous for the translocation produce occasional gametes carrying unbalanced chromosome combinations, and these gametes give rise to the abnormal embryos. Evidence is presented indicating that some of the unbalanced zygotes may develop normally.
An Experimental and Theoretical Investigation of Stick-Slip, Steady-State and Roughness Dominated Sliding in Fiber-Reinforced Composites

The mechanical properties of fiber reinforced composites depends strongly upon the properties of the fiber/matrix interface. Enhanced fracture resistance and strain to failure are synonymous with debonding and sliding of the reinforcement phase. Thus, the two key properties of the composite are the interfacial toughness and the post-debond sliding stress. After debonding a variety of interfacial sliding phenomena are noted, including: stick-slip, steady-state, and roughness dominated sliding. The interfacial properties, including the coefficient of friction, the radial clamping pressure, asperity amplitude, the elastic properties of the constituents, and the compliance of the test machine, each play a role in the operative sliding phenomenon. Experiments have been conducted to explore each of these phenomena. In addition, models have been developed that rationalize all of the observed behavior.
PIV space-time resolution of flow behind blast waves

An ultra-high speed, time-resolved particle image velocimetry (PIV) system is developed to measure velocity fields created by explosive detonators. When initiated into a gas, the detonators generate blast waves that propagate outwards from the origin of initiation at supersonic speeds. The PIV system consists of a custom eight-pulse Nd:YAG laser system and an ultra-high speed camera system comprising four dual-frame CCD cameras optically combined to share a single optic axis. The system is capable of sampling the flow field four times at up to 333 MHz or eight times at up to 8 MHz. System development is discussed, and preliminary application to the complex flow behind the blast wave from an exploding bridge wire detonator is demonstrated.
Synchrotron Radiation: Applications in the Earth Sciences

Synchrotron-radiation sources and their characteristics are overviewed along with recent synchrotron-based research on earth materials and future earth-science applications utilizing the next generation of synchrotron-radiation sources presently under construction. Focus is placed on X-ray scattering studies of earth materials (crystalline and noncrystalline) under ambient conditions, diffraction studies of earth materials at high pressures and/or temperatures, spectroscopic studies, primarily X-ray absorption spectroscopy, and spatially resolved X-ray fluorescence studies of compositional variations in earth materials. It is noted that other synchrotron-based methods, such as X-ray tomography and topography may become important in characterizing earth materials, while soft X-ray/vacuum ultraviolet radiation from synchrotron sources can be applied to problems involving the structural environments of low-atomic-number elements and the characterization of surface reactions of minerals with liquids and gases.
Effect of Anastomotic Angle on Pressure Drop in Arteriovenous Fistulae

The amount of the blood flow rate to an arteriovenous fistula (AVF) is one of the primary factors that determine the likelihood of maturation. The increase in the flow rate is dependent on the amount of the resistive forces in the AVF which can be evaluated by pressure drop (Δp). Our group has shown that the surgical configuration of AVF affects the hemodynamics and thus the remodeling within the AVF. Here, our aim is to study the effect of AVF configuration on the induced Δp. Based on the data collected in our previous in-vivo porcine experiments, idealized models of AVFs with anastomosis angles of 30°, 60°, and 90° were created and numerically solved to find Δp under steady-state conditions. The Δp from the idealized models were within the same range as the experimental data (15.31 ± 3.78 mmHg). The highest and lowest Δp were found to be 14.75 and 6.40 mmHg for the 30° and 90° AVFs, respectively. Moreover, an inverse relationship was found between the Dean number (De) and Δp. As De decreased with increasing radius of curvature (from higher anastomotic angles to the lower), the Δp increased. These data suggest that creating the AVFs in a surgical configuration that results in larger De (lower radius of curvature such as 90° AVF) may achieve higher flow rate due to relatively lower Δp. In contrast, creation of AVF with lower De which represents a sharp bend with high radius of curvature (30° AVF) could be detrimental to AVF maturation as it results in relatively higher Δp.Copyright © 2013 by ASME
Role of parental myopia in the progression of myopia and its interaction with treatment in COMET children.

PURPOSE The present study investigated the relationship between parental refractive error and myopia progression in their offspring and the interaction between parental ametropia and the effects of wearing progressive-addition (PALs) or single-vision (SVLs) lenses on the progression of myopia in children enrolled in the Correction of Myopia Evaluation Trial (COMET). METHODS The progression of myopia in a subset of COMET children (N= 232; 49% of initial group) was defined as the difference in mean spherical equivalent refraction of both eyes obtained by cycloplegic autorefraction between the baseline and 5-year visit. Parental refractions were obtained by noncycloplegic autorefraction (81%) or from recent eye examination records (19%). RESULTS The number of myopic parents (mean spherical equivalent refraction </=-0.75 D) was directly related to myopia progression among children wearing SVLs: myopia in children with no (zero) myopic parents progressed (mean +/- SE) -1.81 +/- 0.18 D and with one myopic parent, -2.04 +/- 0.13) D; these amounts were significantly less than the progression of children with two myopic parents (-2.59 +/- 0.19 D). In the PAL group, progression was not significantly related to the number of myopic parents and was -2.01 D overall. Among children with two myopic parents, progression was -2.00 D in the PAL group, significantly less than the progression of children wearing SVLs (P = 0.03). Among children with zero or one myopic parent, progression did not differ significantly between the lens groups. When the data were adjusted for covariates, the interaction between treatment effect and number of myopic parents was significant (P = 0.01). Over the 5-year study period, axial length increased 0.93 +/- 0.07 mm in children with two myopic parents wearing PALs and 1.18 +/- 0.07 mm in children with two myopic parents wearing SVLs (P = 0.01). The axial length increase in children wearing SVLs and with two myopic parents was significantly more than the 0.89 +/- 0.07 mm increase in children wearing SVLs and with zero myopic parents (P = 0.015). CONCLUSIONS Parental refraction was related to myopia progression and changes in axial length. Among COMET children with two myopic parents, myopia progression and increases in axial length were slower in the group wearing PALs than in those wearing SVLs, by a statistically significant but clinically minor amount. Because this study was ancillary to COMET and the present analyses are based on a subset of participants, conclusions must be regarded as suggestive.
Atomic Scale Investigation of Nanoparticle and Fabrication Temperature Effects on Carbon Nanotube Diameter and Chirality

Carbon nanotubes (CNTs) are one of the best candidates for utilizing in the future nanoelectronic devices. However, the semiconductivity property of CNTs varies as diameter and chirality number change. Several nanoelectronic applications require semiconductivity to be of a certain value with little variability. Therefore, it is necessary to reliably produce uniform CNTs with unique diameter and chirality. However, this still remains one of the challenging problems in the large scale production and application of CNTs. In this paper, the effect of fabrication temperature change on CNTs diameter and chirality are experimentally and theoretically studied. Utilizing chemical vapor deposition (CVD) fabrication process and by conducting experimental investigation, it is observed that a CNT possesses a larger diameter at its base compared to the section far away from deposited nanoparticles. Moreover, using MD simulation technique, it is observed that the energy of the CNTs molecular structure will increase by applying higher fabrication temperature. Usually this energy increase is greater in the thicker CNTs. However, the energy increase percentage is found to be affected by the chirality of the CNT. Among CNTs of the same diameter, the armchair conformation has the highest percent increase, followed by the chiral CNTs, and the zigzag nanotube has the lower percent increase. The obtained results can be utilized in a controllable CNTs diameter and chirality design process.Copyright © 2008 by ASME
E‐commerce marketing strategies: an integrated framework and case analysis

Demonstrates the usefulness of the traditional marketing model in developing e‐commerce marketing strategies. Discusses four e‐commerce frameworks and integrates them with the traditional marketing model (product, price, promotion, and distribution) to develop a complete framework. Discusses how the e‐commerce strategies could be applied to a real company using the integrated model.
Dynamics Experiment and Analysis of a Hard Disk Drive

The dynamics of a commercially available hard disk drive were investigated using both experimen tal and numerical techniques. The drive has a storage capacity of 1 GB with two 3 1/2-inch disks. First, each individual component—disk, suspension assembly, actuator arm, and arm coupled with the assembly—was briefly studied. Then, modalexperiments were performed on the drive in both states of the disks, station ary or rotating. A finite element (FE) model for studying the dynamics of the drive was created. The model consists of one disk, two actuator arms, and two suspension assemblies. Good correlation between the exper iment and FE analysis was achieved. It was shown that the drive exhibits very complicated modal properties and that the actuator arm significantly affects the dynamics of the drive, especially as regards track following of the sliders.
Improved PCR assay for the detection of antigen receptor gene rearrangements.

Abstract The detection of small numbers of leukaemia cells in patients with occult disease has important clinical implications. Leukaemia is a monoclonal disease which frequently displays clonal rearrangement of the T-cell receptor gamma (TCRγ) and/or immunoglobulin heavy chain (IgH) gene. Clone-specific junctional sequences arising as a result of these gene rearrangements provide potentially valuable targets for monitoring residual disease by the polymerase chain reaction (PCR). However, existing strategies for PCR amplification of these clone-specific rearrangements frequently lack the necessary sensitivity or specificity, due either to the small size of the target junctional region, or to interference resulting from polyclonal IgH or TCRγ rearrangements in normal lymphocytes. We have previously described a novel PCR strategy to overcome these obstacles which is based on the design of two overlapping clone-specific PCR primers which span the junctional region. We now describe a modification to this strategy which employs relatively short clone-specific primers which further increases the level of specificity. This new method should improve the detection of residual cells, particularly in those cases displaying small junctional regions. Unlike other strategies, specificity is generated from the initial round of amplification. This non-radioactive technique should thus prove effective in monitoring residual leukaemia in patients.
Laboratory study of hydraulic fracturing pressure data—how valid is their conventional interpretation?

This paper presents some recent results in laboratory-controlled hydrofracturing tests in Niagara dolomite subjected to unequal principal in situ stresses. Our new computerized hydrofracturing set-up is capable of both test parameter control and data acquisition and analysis under the most general state of far-field stress. The objective of these tests was to verify the reliability of suggested techniques for determining the critical pressures involved in stress determination, such as the fracture reopening pressure Pr and the shut-in pressure Ps. The determination of Pr was carried out by comparing digital pressure-time data of the ascending portions of the first and subsequent pressurization cycles, all conducted under the same flowrate. Our preliminary finding is that the value of Pr, taken as the point of departure in the third or fourth cycle, appears to reflect the value of the least horizontal principal stress rather than the minimum tangential stress at the borehole wall. Shut-in pressures were correctly estimated (within 8%) using a statistical exponential pressure-decay model in which a non-linear regression curve fitting technique was employed. We also plotted the pressure-time derivative with respect to pressure, and found that both a bilinear and linear-quadratic regression of the recorded digital data provided good estimates of Ps. Acoustic emission was detected during both fracture extension and closure.
Non-Linear Data Bunch

Application of data bunching to improve chromatographic quality can generally be performed in two ways. One approach is to apply linear data bunching which results in averaging data points and. consequently, risking the loss of information. By appropriately varying data bunch rates at opportune areas in a data series, the original chromatographic information will be preserved. This paper discusses the theory behind the development of a computer algorithm that automatically applies non-linear data bunching to chromatograms. Results show the reduction of data file size while improving chromatogram quality when compared to linear data bunch techniques.
Toward a common prototyping language

Several years ago the U.S. Department of Defense created its Defense Science Board Task Force on Military Software, chaired by Dr. Frederick Brooks, to provide recommendations on how best to solve the problem of escalating military software acquisition costs. The final report (reference 2) of this task force was completed in September 1987, and was widely distributed. Among its several major conclusions are the following: DoD Directive 5000.29 and STD 2167 codify the best 1975 thinking about software, including a so-called 'waterfall' model calling for formal specification, then request for bids, then contracting, delivery, installation, and maintenance. In the decade since the waterfall model was developed, our discipline has come to recognize that setting the requirements is the most difficult and crucial part of the software building process, and one that requires iteration between the designers and users. In best modern practice, the early specification is embodied in a prototype, which the intended users can themselves drive in order to see the consequences of their imaginings. Then, as the design effort begins to yield data on the cost and schedule consequences of particular specifications, the designers and the users revise the specifications.Directive 5000.29 not only does not encourage this best modern practice, it essentially forbids it. We recommend that it be revised immediately to mandate and facilitate early prototyping before the baseline specifications are established.DoD STD-2167 likewise needs a radical overhaul to reflect best modern practice. Draft DoD STD 2167A is a step, but it does not go nearly far enough. As drafted, it continues to reinforce exactly the document-driven, specify-then-build approach that lies at the heart of so many DoD software problems.
Some Problems, Pitfalls, and Paradoxes in Educational Measurement

This article provides brief discussions of an eclectic set of problems, pitfalls, and paradoxes that challenge measurement theory and practice, especially for K–12 achievement testing. The technical issues considered are: true scores and error scores, fixed versus random facets, lower limits to reliability, the reliability-validity paradox, reliability of difference scores, equating and linking, and scaling. The practical issues considered are: validation, standard setting, instructional improvement and high-stakes accountability, multiple measures, adequate yearly progress, the National Assessment of Educational Progress as a confirmation model, and capacity.
Stress-optical properties of bimodal polymer networks

The optical properties of bimodal poly(dimethylsiloxane) (PDMS) networks were studied with special emphasis on the non-linear stress optical properties exhibited by these materials. In particular the effect of chain length, and junction functionality on the strain induced birefringence was investigated. It is shown that for the non-linear properties to clearly manifest themselves a critical concentration of short chains is essential and that the junctions are tetra-functional. However, all bimodal compositions studied were found to exhibit a non-linear variation of birefringence with strain irrespective of the junction functionality. The optical properties of the unimodal networks were found to vary linearly with stress and strain as expected. The transition from non-linear to linear optical behavior on increasing the molecular weight of the short chains is also established.
Computer-Assisted Instruction: Is It an Option for Bibliographic Instruction in Large Undergraduate Survey Classes?

Developing effective library instruction for large undergraduate survey courses can be a difficult task. In 1993, librarians at UCLA’s Louise M. Darling Biomedical Library decided to develop a computer-assisted library instruction program for the roughly 800 to 900 undergraduate biology students per year who are enrolled in the department’s basic, required-for-the-major introductory course. A formal summative evaluation of the effectiveness of this CAI, as compared to the lecture method, also was developed. The evaluation utilized both a quantitative pre- and posttest design using objective questions and a qualitative follow-up survey featuring open-ended questions.
Electron paramagnetic resonance of Ge donors in GaP

Abstract The EPR of the group IV donor Ge in GaP behaves differently from that of the other group IV donors Si and Sn. The spectrum is observable without the application of a uniaxial stress and the g -value ( g = 2.000 ± 0.003) and linewidth are independent of the magnitude and the direction of stress. Possible explanations of this anomaly are discussed.
Vascular targeted radioimmunotherapy with 213Bi-An α-particle emitter

To destroy both tumor blood vessels and adjacent tumor cells, an alpha-particle emitter, 213Bi, has been targeted with a monoclonal antibody (MAb) to vessels that feed lung tumors in mice. Animals, bearing approximately 100 EMT-6 carcinomas each of 50-400 cells in size in the lung, that were treated with 120 muCi of 213Bi-MAb 201B were all cured of their disease. Animals treated when tumors were larger (10(3)-10(4) cells) had extended life spans, but a small number of residual tumors eventually killed the animals. Significant extension of life span was also induced with another tumor model-rat tracheal carcinoma growing in the lungs of SCID mice that were then treated with 136 muCi 213Bi-MAb 201B. These studies indicate that attack of both blood vessels and tumor cells simultaneously is an effective mode of cancer treatment.
β-Sheet Hydrogen Bonding Patterns in Cystine Peptides

Cystine peptides have been shown to adopt conformations in organic solvents that mimic small β-sheets. Relative hydrogen bond strengths, β-strand aggregation, and the identity of individual hydrogen bond donors and acceptors have been identified through hydrogen/deuterium exchange.
Changes in physical and chemical properties of shortenings used for commercial deep‐fat frying

This study evaluated some of the changes that occur in shortenings used for commercial deep-fat frying in fast-service restaurants. Foods cooked in partially hydrogenated soybean oil were battered chicken parts and french fries. Sixty-five samples of fresh and used shortenings were collected from nine restaurants on three occasions over a three-month period. Frying periods varied from 0 to 300 hr, and most samples were taken just before the used fat was discarded. For fresh shortenings, percentages of polar materials, free fatty acids (FFA), materials not eluted by gas chromatography, and fatty acid profiles differed only slightly. For used samples, there were marked variations in these analyses and in increases of dielectric constant measurements. Frying times were highly correlated with increases in dielectric constant, polar materials and FFA. The greatest change in fatty acid profiles occurred intrans-C18 monoenes which decreased from over 40% to as low as 13%. Due to lipid exchange with chicken fat, both oleic and linoleic acids increased in the shortenings with hours of use, whereas stearic acid decreased. There were high correlations, among increases in dielectric constant, percentages of polar materials and FFA, demonstrating that each of these methods could predict degradation of the shortening. However, the increase in dielectric constant, as measured by a Foodoil Sensor (FOS), was the most convenient for quality control in restaurant situations. In most cases, used shortening was discarded before 100 hr of frying time; and only a few of these samples had FOS readings near 4.0, FFA over 1.00%, or percentages of polar materials over 27%. These values have been suggested as discard criteria. However, a number of samples used between 100 and 300 hr exceeded these limits. There is a need to specify suitable limits, related to quality and health factors, to determine at what point a cooking fat should be discarded.
Multiple mechanisms in hepatic microsomal azoreduction.

1. Microsomal reduction of azo dyes related to dimethylaminoazobenzene (DAB) is catalysed by at least two types of cytochrome P-450. The first is selectively induced by clofibrate. The second is induced by phenobarbital, β-naphthoflavone, isosafrole, and pregnenolone-16α-carbonitrile, as well as clofibrate.2. Azoreduction by the first type of P-450 is insensitive to both O2 and CO and involves dyes with only electron-donating substituents (I substrates).3. Azoreduction by the second type of P-450 is inhibited by both O2 and CO and involves dyes with electron-withdrawing as well as donating substituents (S substrates).4. All azo dye substrates exhibit two negative and one positive redox potential, as measured anaerobically by cyclic voltammetry. The negative potentials reflect one- and two-electron reductions while the positive potential permits electron transfer from microsomal P-450, the redox potential for which is reported to be negative (∼0.35 V). The positive potential is associated with a polar elec...
Optimizing Contaminant Desorption and Bioavailability in Dense Slurry Systems. 2. PAH Bioavailability and Rates of Degradation

The effects of mechanical mixing on rates of polycyclic aromatic hydrocarbon (PAH) biodegradation in dense geosorbent slurry (67% solids content, w/w) systems were evaluated using laboratory-scale intermittently mixed batch bioreactors. A PAH-contaminated soil and a phenanthrene-sorbed mineral sorbent (α-Al2O3) were respectively employed as slurry solids in aerobic and anaerobic biodegradation studies. Both slurries exhibited a characteristic behavior of pseudoplastic non-Newtonian fluids, and the impeller revolution rate and its diameter had dramatic impacts on power and torque requirements in their laminar flow mixing. Rates of phenanthrene biodegradation were markedly enhanced by relatively low-level auger mixing under both aerobic and anaerobic (denitrifying) conditions. Parameters for empirical models correlating biodegradation rate coefficient (kb) values to the degree of mixing were similar to those for correlations between mass transfer (desorption) rate coefficient (kr) values for rapidly desorbi...
LightSphere: fast lighting compensation for matching a 2D image to a 3D model

We describe a fast object recognition method that identifies 2D color image queries among a set of 3D models. It is fast enough for searching a very large database. The main application is face recognition, for which we report very good accuracy over a wide range of pose and lighting conditions. We make weaker assumptions about both lighting and reflectance than are usual. We avoid finding eigenvectors or solving systems of equations. Instead, we use the query to estimate a specialization of the BRDF to the fixed lighting and pose of the query. In a single image pass, we compute a lookup table for re-rendering, which represents expectation values for the action of the light via the BRDF. This yields a similarity measure of the consistency between model and query under the regularity assumptions. We report recognition results on a data set of 42 3D face models and 1764 query images, comprising 7 poses and 6 lighting conditions. The recognition accuracy is indistinguishable from much slower methods, which make stronger assumptions about the BRDF and lighting.
A resonant cavity violet vertical cavity light emitting diode incorporating AlGaN DBR mirrors

Summary form only given. Advances in nitride-based blue and violet LEDs and lasers now suggest possibilities for more advanced geometries such as those based on vertical cavity structures. In our work, we have approached the design and fabrication of high-Q planar resonators by two methods. First, we have employed a lift-off method to separate the InGaN MQW heterostructure from its sapphire substrate so as to encase it within a high-Q cavity equipped by two dielectric DBRs. In this instance, first demonstrations of resonant cavity blue LEDs have been made. Secondly, we have revisited the very difficult problem of morphological quality of the in-situ grown AlGaN DBRs. Due to a small index contrast, these DBRs are generally plagued by defects such as cracks which form 'lateral cavities' and can lead to erroneous interpretation eg. of stimulated emission phenomena. In particular, by employing special strain engineering techniques, the nitride DBRs have recently improved to the point where such mirrors have been paired with dielectric DBRs for InGaN QW optical structures to achieve room temperature continuous-wave optically pumped near ultraviolet (380 nm). Here we show how an effective RCLED can be fabricated by incorporating an in-situ grown AlGaN/GaN DBR atop which the active InGaN MQW medium is grown, topped by a dielectric DBR.
Environmentally induced epigenetic transgenerational inheritance of phenotype and disease

Environmental epigenetics has an important role in regulating phenotype formation or disease etiology. The ability of environmental factors and exposures early in life to alter somatic cell epigenomes and subsequent development is a critical factor in how environment affects biology. Environmental epigenetics provides a molecular mechanism to explain long term effects of environment on the development of altered phenotypes and “emergent” properties, which the “genetic determinism” paradigm cannot. When environmental factors permanently alter the germ line epigenome, then epigenetic transgenerational inheritance of these environmentally altered phenotypes and diseases can occur. This environmental epigenetic transgenerational inheritance of phenotype and disease is reviewed with a systems biology perspective.
Fractional vortices in the XY model with π bonds

We define a new set of excitations in the $\mathrm{XY}$ model which we call ``fractional vortices.'' In the frustrated $\mathrm{XY}$ model containing $\ensuremath{\pi}$ bonds, we make the ansatz that the ground state configurations can be characterized by pairs of oppositely charged fractional vortices. For a chain of $\ensuremath{\pi}$ bonds, the ground state energy and the phase configurations calculated on the basis of this ansatz agree well with the results from direct numerical simulations. Finally, we discuss the possible connection of these results to some recent experiments by Kirtley et al. [Phys. Rev. B 51, R12 057 (1995)] on high-${T}_{c}$ superconductors where fractional flux trapping was observed along certain grain boundaries.