cssi/SciSciGPT-SciSciNet huggingface dataset:
Ion Backscattering Study of WSi2 Layer Growth in Sputtered W Contacts on Silicon

Helium ion backscattering has been used to study the reaction kinetics in samples composed of thin (~ 2200 A) W films dc sputtered onto chemically cleaned P or B doped (111) single crystal Si substrates. At temperatures in the range 625 C to 750 C, Si is observed to migrate into the W films and form a well-defined WSi2 reaction layer. Typically, at 650 C, about 750 A of W is consumed in four hours. A detailed comparison of the backscattering spectra indicates that the WSi2 reaction layer grows approximately as tn where n ≈ 1 during the initial growth but then decreases to n ≃ 1/2 when the W films are over 30% reacted. An activation energy which characterizes the initial stage of WSi2 layer growth is 63–71 kcal/ mole for 35% W film reaction (2000 A WSi2 formed). This activation energy is somewhat higher than the 50 kcal/mole reported by other investigators for WSi2 layer growth at temperatures over 850 C where layer growth was observed to be governed by t1/2 kinetics. A preliminary estimate of the activation energy governing the beginning of the t1/2 layer growth observed here is 60 ± 15 kcal/mole. Prior to complete reaction of W films aged in the temperature range 625 C to 730 C, an upper limit of 2 at.% Si is observed for the Si concentration in the unreacted portion of the W film.
The Effect of Bentyl Hydrochloride on Intraluminal Pressures of the Stomach and Duodenum

Summary The effects of parenteral administration of Bentyl on the motor activity of 41 patients were measured by employing an intraluminal pressure recording technique. Subcutaneous administration of the drug in doses from 5 to 40 mg. failed to abolish wave activity but the higher doses depressed large waves in some patients. Intramuscular administration of Bentyl in doses of 5 to 200 mg. produced little or no effect when the 5- or 10-mg. doses were employed, but usually depressed large waves or abolished activity when larger doses were used. Even higher doses of the drug were required to depress Urecholine-induced activity than were necessary to effect spontaneous activity. Clinical trial of the drug in 41 patients with abdominal pain revealed that the majority required 25 to 37.5 mg. taken three times daily to obtain relief of symptoms.
Adolescent Literacy: Putting the Crisis in Context

In this article, Vicki Jacobs argues that as the nation strives to improve the literacy achievement of U.S. adolescents, educators must reframe the current "crisis" as a critical point on a continuum of historical efforts to address the particular challenges of postprimary-grade reading. Specifically, Jacobs examines the definition of adolescent literacy in the context of reading stages, which explain the contiguous and continuous relationship between primary-grade and later reading. She also discusses how historical relationships between skill and process instruction and between reading specialists and content-area faculty have contributed to the issues we face at this particular point on the continuum. Jacobs concludes by highlighting the opportunities ahead for researchers, policymakers, and practitioners who are positioned to respond to the adolescent literacy crisis and improve adolescent literacy achievement.
Codon Substitution in Evolution and the "Saturation" of Synonymous Changes

ABSTRACT A mathematical model for codon substitution is presented, taking into account unequal mutation rates among different nucleotides and purifying selection. This model is constructed by using a 61 × 61 transition probability matrix for the 61 nonterminating codons. Under this model, a computer simulation is conducted to study the numbers of silent (synonymous) and amino acid-altering (nonsynonymous) nucleotide substitutions when the underlying mutation rates among the four kinds of nucleotides are not equal. It is assumed that the substitution rates are constant over evolutionary time, the codon frequencies being in equilibrium, and, thus, the numbers of synonymous and nonsynonymous substitutions both increase linearly with evolutionary time. It is shown that, when the mutation rates are not equal, the estimate of synonymous substitutions obtained by F. Perler, A. Efstratiadis, P. Lomedico, W. Gilbert, R. Kolodner and J. Dodgson9s "Percent Corrected Divergence" method increases nonlinearly, although the true number of synonymous substitutions increases linearly. It is, therefore, possible that the "saturation" of synonymous substitutions observed by Perler et al. is due to the inefficiency of their method to detect all synonymous substitutions.
Inmate Racial Integration: Achieving Racial Integration in the Texas Prison System

After nearly three decades, there has been a revival of interest in the racial integration of inmates in prisons. In light of what has been done, the literature still questions whether racial integ...
Technical Note-Comments on a Paper by S. G. Allen and D. A. D'Esopo: An Ordering Policy for Repairable Stock Items

This note considers an inventory model for repairable stock items for which S. G. Allen and D. A. D'Esopo had previously derived an approximate expression for backorder rate, derives an exact expression for the stationary distribution of stock on hand and backordered under considerably more general assumptions, and shows that the backorder rate can be calculated exactly from this. The stationary expected number of backorders per unit time can also be calculated from this distribution.
Narrative approach to assessing interactions between society, community, and person

Community Psychology has historically sought to understand interactions between society, communities, and individuals. This article explores the use of narrative as a method for understanding these interactions. Public housing is the context for this exploration. Recurring, pathological themes were found in 100 stories written about fictional residents of a public housing project by non-residents. Similar story themes are suggestive of the existence of societal-level narratives about public housing and public housing residents. Societal-level narratives are thought to profoundly influence public housing residents' community and personal narratives, as evidenced by stories told by residents. The implications for using narrative methods and community organizing as a narrative intervention are discussed. © 1998 John Wiley & Sons, Inc.
Polydimethylsiloxane–vinyl block polymers. II. The synthesis and characterization of block polymers by the thermolysis of polydimethylsiloxane macroinitiators containing bis(silyl pinacolate) groups

The thermolysis of polydimethylsiloxanes containing thermally labile bis(silyl pinacolate) groups in the backbone in the presence of various vinyl monomers leads to the direct synthesis of block polymers. Depending on the monomer chosen, simple triblock or multisequence block polymers can be readily prepared. Analysis of the products of the block polymerizations using various styrenic-type monomers shows that only block polymers are obtained, i.e., no homo-polymers are formed. These block polymers display evidence of phase separation such as intense iridescence and solvent-dependent mechanical properties. The mechanical properties of these block polymers have been measured and found to be highly composition dependent. Depending on the block length and the relative portions of the hard (vinyl) and soft (polydimethylsiloxane) blocks, one can produce either thermoplastic elastomers or rubber-modified thermoplastics.
Optimal Treatment Adherence Counseling Outcomes for People Living with HIV and Limited Health Literacy

Limited health literacy has been shown to contribute to poor adherence to antiretroviral therapy (ART) in people living with HIV/AIDS. Given the mixed results of previous interventions for people with HIV and low health literacy, investigating possible targets for improved adherence is warranted. The present study aims to identify the correlates of optimal and suboptimal outcomes among participants of a recent skills-based medication adherence intervention. This secondary analysis included 188 men and women living with HIV who had low health literacy and who had complete viral load data. Adherence was assessed by unannounced pill count and follow-up viral loads were assessed by blood draw. Results showed that higher levels of health literacy and lower levels of alcohol use were the strongest predictors of achieving HIV viral load optimal outcomes. The interplay between lower health literacy and alcohol use on adherence should be the focus of future research.
TU‐C‐211‐04: Time‐Resolved Cone‐Beam CT for Cardiac Interventions

Purpose: To obtain artifact‐free 3D images with high temporal resolution from truncated projection data recorded using a cardiac interventional system with a slowly rotating gantry and a small flat‐panel detector. Methods: In order to reconstruct time‐resolved cardiac images from truncated projections, one must be able to achieve ultra‐high temporal resolution, while also mitigating truncation artifacts. Both of these goals can be achieved using an adapted implementation of the prior image constrained compressed sensing (PICCS) algorithm. To demonstrate this, a canine animal model was scanned in vivo using an interventional C‐arm system with a 40×40 sq cm detector in a single rotation 14‐second acquisition. The projections were artificially truncated to simulate the use of a 20×20 sq cm detector commonly used in many cardiac intervention suites. The projections were gated retrospectively using the recorded ECG signal into 20 cardiac phases. The data from each phase were reconstructed using the PICCS algorithm. The reconstruction accuracy was assessed by evaluating image quality of both truncated and non‐truncated datasets. Results: The imagesreconstructed from truncated data using the PICCS algorithm resulted in a root mean square deviation of about 2.5% with respect to the non‐truncated data. Furthermore, the truncated PICCS reconstructions did not contain artifacts that plagued the imagesreconstructed using the FDK algorithm from the same datasets. The temporal resolution achieved in this study was about 33 ms. The PICCS reconstructions were generated in under 2 minutes per phase for a 256×256×128 image volume using a GPU‐based implementation. Note that the reconstruction of each phase can be processed in parallel. Conclusions: Artifact‐free time‐resolved cardiac imaging is achievable using a cardiac intervention C‐arm system with a slowly rotating gantry and the PICCS algorithm. Further optimization could bring the reconstruction time to a level adequate for the interventional setting. Grant from GE Healthcare (Waukesha, WI)
Variation of the oxygen content and point defects in olivines, (Fe x Mg 1-x ) 2 SiO 4 , 0.2 <= x <= 1.0

The variation of the oxygen content in olivines, (Fe x Mg1− x )2SiO4, with 0.2 ≤ x ≤ 1.0, was investigated by thermogravimetric measurements. Mass changes occurring upon oxygen activity changes were measured as a function of oxygen activity and cationic composition at 1130 and 1200 °C. During the measurements the samples were in direct contact with gases containing CO, CO2 and N2 and, at a few spots at the bottom of the sample stack, also with SiO2. By fitting experimental data of mass changes to equations derived using point defect thermodynamics, it was shown for olivines with 0.2 ≤ x ≤ 1.0 at 1130 °C and 0.2 ≤ x ≤ 0.7 at 1200 °C within the oxygen activity ranges investigated that the observed variations in the oxygen contents are compatible with cation vacancies and Fe3+ ions on M sites and Fe3+ ions on silicon sites as majority defects if it is assumed that only three types of point defects occur as majority defects. Different cases were considered, closed systems, taking into account that ξ=[Si]/([Si]+[Fe]+[Mg]) is not necessarily equal to 1/3, and olivines in equilibrium with SiO2 or pyroxenes. The oxygen content variations observed in this study are significantly smaller than those reported previously in the literature. It is proposed that these differences are related to the dissolution of Fe into noble metal containers used as sample holders in earlier studies and/or to the presence of secondary phases.
Buoyant Flow and Heat Transfer in a Conducting Baffle

A numerical simulation of transient two-dimensional negatively buoyant flow into a straight baffle situated below an isothermal circular cylinder is performed. Both an adiabatic and a highly conducting baffle are considered over a range of Rayleigh numbers, 106 < RaD < 107 . During the quasi-steady-state period, the surrounding fluid is effectively considered infinite in extent and at constant temperature. It is found that in general, the conducting baffle is at a disadvantage in maintaining a short attachment length which is needed to optimally slow the flow to prevent mixing. Qualitative flow fields are shown and heat transfer rates to the cylinder are calculated at the quasi-steady state.Copyright © 2008 by ASME
Modals with a taste of the deontic

The aim of this paper is to present an explanation for the impact of normative considerations on people's assessment of certain seemingly purely descriptive matters concerning freedom, causation, and intentionality. The explanation is based on two main claims. First, the relevant judgments are modal: the sentences evaluated are contextually equivalent to modal proxies. Second, the interpretation of predominantly circumstantial or teleological modals is subject to normative constraints which make certain possibilities salient at the expense of others. http://dx.doi.org/10.3765/sp.6.1 BibTeX info
Working PACS prototype

AbstractSeveral PACS prototypes are currently being constructed across the country. This arti-cletracesthrough the development of one such prototype at the University of Kansas. Theprototype consists of three types of nodes; an image acquisition node, an archival node anda display node. These nodes communicate with one another via an Ethernet protocol. Thereader will gain a view of the prototypes hardware and software architecture as it is to date. Motivations for key engineering decisions will be presented. Finally, the currentstatus and future plans for the prototype will be discussed.IntroductionTen years ago, the typical hospital radiology department would consist of several adja-cent rooms where radiologists and technicians would expose radiographic films on conven-tional x -ray machines, process the film and view the resulting images. A short term filmfile would be maintained near the viewing room. Long term (archival) filing would usuallybe done in a remote location, often on the other side of the hospital in an area that couldnot be used for anything else. The viewing room would often become littered with film andfilm jackets. Doctors frequently removed films to locations outside the radiology depart-ment for consultations. As a result, a patient's films were sometimes misfiled or lost al-together.Many technological changes have occurred in the radiology department since then. Moderndepartments contain new diagnostic radiological modalities such as CT scanners, ultrasoundunits, etc. These modalities may be located in rooms across from the conventional x -rayequipment, or they may be in a separate area of the hospital well removed from the regular
Thrombotic Storm: When Thrombosis Begets Thrombosis

Patients with hypercoagulability may present with a single thrombosis and subsequently develop progressive thromboses at other sites. With inadequate therapy, the thrombotic process may self-perpetuate, leading to multiple thromboses and even death. Six cases are presented demonstrating key features of what may be termed thrombotic storm: (1) an underlying hypercoagulable disorder; (2) a provocation to initiate thrombosis; (3) rapid development of new thromboses; (4) response to prompt use of thrombolytic agent or anticoagulant therapy; and (5) remarkable good long-term prognosis if the cycle of thrombosis is interrupted. Continued activation of coagulation by fresh thrombosis is hypothesized as the cause of the syndrome, which may explain its control by anticoagulants. Whereas these unusual patients' courses most likely represent only an extreme of hypercoagulability and not a new disorder, their characteristic behavior warrants attention.
Perceptual media compression for multiple viewers with feedback delay

Human eyes have limited perception capabilities; for example, only 2 degrees of our 140 degree vision field provide the highest quality of perception. Due to this fact the idea of perceptual focus emerged to allow a visual content to be changed in a way that only part of the visual field where a human gaze is directed is encoded with a high quality. The image quality in the periphery can be reduced without a viewer noticing it. This compression approach allows a significant decrease in the number of bits required for image encoding, and in the case of the 3D image rendering, it decreases the computational burden. A number of previous researchers have investigated the topic of perceptual focus but only for a single viewer. In our research we investigate a dynamically changing multi-viewer scenario. In this type of scenario a number of people are watching the same visual content at the same time. Each person has his/her own perceptual focus area which changes over time. The visual content is sent through a network with a fixed delay/lag which provides an additional challenge to the whole scheme. The goal of our work was to investigate and develop a method of multi-viewer perceptual focus zones adaptation for real-time media perceptual compression and transmission. In our research we also look into the impact that such a method can have on transmission bandwidth and computational burden reduction.
Modelling Kepone in the striped bass food chain of the James River estuary

Abstract A mathematical model that computes the accumulation of Kepone in the striped bass food chain of the James River estuary was developed. The purpose of the model was to help understand the relationship of Kepone levels in important fish species to sediment and water column Kepone concentrations and then to address the question of why these levels still exceed Food and Drug Administration limits eight years after discharge ceased. The model considers exposure through diet and respiration at rates based on species bioenergetics. It was successfully calibrated to the Kepone concentrations observed in the period 1976 through 1982 in striped bass, white perch, and Atlantic croaker. The model indicates that for the upper levels of the food chain, diet is the major route of contamination, accounting for 87–88% of the observed concentration in croaker and white perch and 91% of the observed concentration in striped bass. The two Kepone sources; sediment and water column, contribute approximately equally to the croaker and white perch. The water column is more significant for striped bass, being the original source for approximately 60% of the observed body burdens. It was estimated that a criterion requiring Kepone concentrations in fish to be at or below 0·3 μg g−1 would require dissolved water column and sediment Kepone concentrations to be reduced to somewhere between 3 and 9 ng l−1 and 13–39 ng g−1, respectively, depending on the species. Striped bass require the greatest reductions in dissolved water column and sediment Kepone concentrations to somewhere between 3 and 5 ng l−1 and 13 and 24 ng g−1, respectively.
Occurrence of a furin-like prohormone processing enzyme in Aplysia neuroendocrine bag cells

1. 1. Strong evidence is accumulating that the endoproteases which process prohormones at dibasic residue cleavage sites are members of a subtilisin-related class of proteases. 2. 2. Using the polymerase chain reaction (PCR), we have isolated and characterized an Aplysia californica neuroendocrine bag cell cDNA product (270 base pairs) that encodes a sequence which is highly homologous to the subtilisin-related class of processing proteases that includes yeast Kex2, human/mouse/Drosophila furin, human PC2, and mouse PC1/PC3 and PC2. 3. 3. The characterized cDNA PCR product showed the highest degree of residue identity with the furin-related group of proteins (human/mouse furin 71%; Drosophila furin 63%). 4. 4. These results establish that Aplysia contain a subtilisin-like gene and suggest that the expression of this gene may play a role in processing Aplysia precursor proteins in the bag cells and likely also in the exocrine atrial gland. 5. 5. Furthermore, the Aplysia nucleotide sequence results, together with available sequence information from human, mouse, and Drosophila furins, provide reasonable evidence that the furin-like enzymes may represent a separate subclass of the subtilisin-like processing enzymes.
Effects of surface conditions on organic matter measurements of a soil sensor

Abstract A set of experiments was conducted to examine the effects of soil surface roughness and surface color discontinuities on a real-time soil organic matter sensor. The purpose of such a soil sensor is to accurately measure soil properties; thus providing information that can be used to set chemical and fertilizer application rates. After examining several chemical application labels it was determined that 1% organic matter error should be considered significant in data used for controlling chemical application. It was hypothesized that soil surface roughness and surface color discontinuities might produce significant errors in the prediction of soil organic matter levels. The effects of surface roughness were examined at two different sensor elevations relative to the average height of the sample profile. Sensor measurements in response to color discontinuities, to approximate non-decomposed plant matter, during calibration procedures was examined. Color discontinuities with a width of 3.0 mm were found to produce measurement errors of more than 6.0% soil organic matter content. It was also found that rough surfaces can produce significantly low organic matter measurements during field use. Both error sources produce artificially low organic matter measurements during field use, while this does reduce the yield potential of a field, it also reduces the potential for water contamination. Calibration samples should be free of all non-decomposed plant matter, and as smooth as possible to prevent artificially high organic matter measurements. Rough samples or samples with non-decomposed plant matter, used during the calibration procedure would result in too much chemicals being applied to a field, increasing water contamination potential.
Pancreatic cancer and comparison of a hospital-based tumor registry with a national cancer data base

Background The Commission on Cancer of the American College of Surgeons has called upon institutions providing cancer care to compare practice patterns and outcomes with the National Cancer Data Base (NCDB). Using data from the Virginia Mason Tumor Registry (VMTR), we sought to compare our pancreatic cancer care patterns with those reported nationally, while critically evaluating the accuracy and usefulness of our registry. Methods A review of the 906 computerized patient files in the VMTR from 1973 to 1995 was performed, with more detailed data on patients from the last 5 years retrieved from 224 manual abstracts. These data were compared with the 1991 NCDB for pancreatic cancer. Results The percent of cases according to AJCC stage in the NCDB (n = 9,715) versus the VMTR (n = 149), respectively, with cases of unknown stage excluded, were stage I 22% versus 22%, stage II 9% versus 12%, stage III 17% versus 28% ( P P P P Conclusions In comparison with the NCDB, VMTR may have fewer stage IV pancreatic cancers, but improvement is needed in decreasing the number of patients for whom the stage is unknown, as many of these likely represent late stage disease. We have a similar resection rate and a higher survival compared with the NCDB, but a mechanism is not in place to statistically compare our survival data with those of the NCDB. Even though all accredited hospitals are required to have a tumor registry, our data were difficult to compare with those of the NCDB because of coding and reporting deficiencies and inability to statistically compare survival data. Before our practice patterns and outcomes can be compared with national standards, both the VMTR and the NCDB must have standardized data collection and better access to the data.
NONPHOTOREALISTIC VIRTUAL ENVIRONMENT NAVIGATION FROM IMAGES

This paper presents a novel scheme based on a hybrid NPR/IBMR approach, for providing non-photorealistic virtual environment navigation from images. As a preprocess, we first divide the background and the foreground components in the image and then construct a simple 3D scene model consisting of background model and foreground object models, together with the corresponding non-photorealistic texture maps. Thus, through interactive navigation at runtime, non-photorealistic walk-through images for novel viewpoints can be generated in real time. To reduce visual artifacts in the resulting animation, we propose an effective method for generating multiresolution and view-dependent non-photorealistic texture maps that preserve the stroke size and coherence across different viewing resolutions and angles.
Deterioration of plastic films under soil burial conditions

The deterioration of polyolefin, poly(ethylene terephthalate), and polyamide films under soil burial conditions extending up to 32 months has been investigated. Based on changes in their elongation at break, the films can be ranked in order of increasing sensitivity to degradation: Polyester ≃ polypropylene < low-density polyethylene ≃ high-density polyethylene < nylon 6.6. The degraded nylon 6.6 and polyethylene films were characterized by infrared and luminescence spectroscopy and scanning electron microscopy, as well as by wet analysis for hydroperoxides. From a comparison with the well-known oxidative sensitivity of nylon 6.6 in oxygenated water at slightly elevated temperatures, the rapid deterioration of nylon 6.6 film during soil burial was also concluded to be an oxidative process. The somewhat smaller, but significant, embrittlement of the polyethylenes studied could not be simply explained by thermal oxidation (with only trace oxidation products detectable) or microbiological attack (deterioration being unaffected by surface activation to enhance wettability).
Technology transfer with an intellectual-properties focus

At universities, especially technological ones, technology transfer takes many forms and involves many groups and individuals-faculty, staff, students, research institutes, and others. A number of mechanisms are at work with several foci. This paper describes a case at Michigan Technological University in which the concept of intellectual property is the focus for technology transfer. This focus seems to better facilitate some desirable and beneficial results, particularly those of a long-term nature, including faculty, staff, and student development.
Stereospecific actions of the inhalation anesthetic isoflurane at the GABAA receptor complex.

The inhalation anesthetic isoflurane stereoselectively modulates ligand binding to the GABAA receptor complex The (+)-isomer of isoflurane was more potent and efficacious than the (-)-isomer in enhancing [3H]flunitrazepam binding to benzodiazepine receptors. For example, concentration effect curves for Cl− enchancement of [3H]flunitrazepam binding were significantly different (P 0.05), although at higher concentrations (>0.1 mM) (+)-isoflurane produced significantly more inhibition than (-)-isoflurane. While the absolute potency differences between isomers were modest (≦2-fold) and measure dependent, these effects were manifested at clinically concentrations of isoflurane and are consistent with in vivo studies demonstrating (+)-isoflurane is a more effective anesthetic than the (-)-isomer. This is the first demonstration of an inhalation anesthetic producing a stereoselective perturbation of the GABAA receptor complex.
High-performance MOCVD-grown AlGaAs/GaAs heterojunction bipolar transistors with carbon-doped base

Excellent microwave performance is demonstrated by metalorganic chemical vapor deposition (MOCVD) grown AlGaAs/GaAs heterojunction bipolar transistors (HBTs) with carbon-doped base. These devices achieve a current-gain cutoff frequency of 76 GHz and a maximum frequency of oscillation of 102 GHz. Varying the device structures allows the current gain to reach over 300 in structures with a base doping of 2*10/sup 19 /cm/sup -3/. A static divide-by-four divider implemented with C-doped base HBTs has been operated up to a frequency of 20.4 GHz. These results indicate the suitability of carbon doping for high-performance HBTs. >
A method for modelling microstructural material discontinuities in a finite element analysis

A new method is proposed for studying the effects of various microstructural material discontinuities, within a body, in a finite element analysis. The material discontinuities are accounted for by introducing a transformation strain in those regions. This formulation leads to two matrix equations; the first corresponds to the finite element analysis of the body without material discontinuities, and the second accounts for the microstructure. An important feature of the new method is that the first equation is solved only once, then the second equation can be solved repetitively for different microstructures. Thus, it is possible to study the effect of different microstructures within the body without reanalysing the entire body. It is expected that this method will be particularly useful in materials research to study the mechanisms that occur in materials at the microstructural level. The transformation strain formulation is reviewed, and the matrix equations for the new method are derived. Several numerical examples are presented to illustrate the versatility of the new method.
Optimal Model-Following Suspension with Microcomputerized Damping

The problem of vibration isolation is investigated from the standpoint of modern control and optimization theory. The proposed optimal model-following suspension design was verified experimentally by means of a microcomputerized suspension model. The experimental results are very encouraging and indicate promising potential application of the proposed scheme to real-world systems. This paper describes the modeling and formulation of an optimal control suspension reference model, and the implementation algorithm of the proposed microcomputerized optimal model-following suspension scheme.
Codon Optimality Is a Major Determinant of mRNA Stability

mRNA degradation represents a critical regulated step in gene expression. Although the major pathways in turnover have been identified, accounting for disparate half-lives has been elusive. We show that codon optimality is one feature that contributes greatly to mRNA stability. Genome-wide RNA decay analysis revealed that stable mRNAs are enriched in codons designated optimal, whereas unstable mRNAs contain predominately non-optimal codons. Substitution of optimal codons with synonymous, non-optimal codons results in dramatic mRNA destabilization, whereas the converse substitution significantly increases stability. Further, we demonstrate that codon optimality impacts ribosome translocation, connecting the processes of translation elongation and decay through codon optimality. Finally, we show that optimal codon content accounts for the similar stabilities observed in mRNAs encoding proteins with coordinated physiological function. This work demonstrates that codon optimization exists as a mechanism to finely tune levels of mRNAs and, ultimately, proteins.
Volatility of trail marking substance of the town ant.

WE have found that the trail marking substance laid down by the town ant, Atta texana (Buckley), contains at least two components, one volatile and the other nonvolatile ; both are followed by workers. Both components partition into the organic phase of a methylene chloride water system.
Modeling of air sparging of VOC-contaminated soil columns

Abstract Air sparging is a remediation technology currently being applied for the restoration of sites contaminated with volatile organic compounds (VOCs). Attempts have been made by various researchers to model the fate of VOCs in the gas and liquid phase during air sparging. In this study, a radial diffusion model with an air–water mass transfer boundary condition was developed and applied for the prediction of VOC volatilization from air sparging of contaminated soil columns. The approach taken was to use various parameters such as mass transfer coefficients and tortuosity factors determined previously in separate experiments using a single air channel apparatus and applying these parameters to a complex system with many air channels. Incorporated in the model, is the concept of mass transfer zone (MTZ) where diffusion of VOCs in this zone was impacted by the volatilization of VOCs at the air–water interface but with negligible impact outside the zone. The model predicted fairly well the change in the VOC concentrations in the exhaust air, the final average aqueous VOC concentration, and the total mass removed. The predicted mass removal was within 1% to 20% of the actual experimental mass removed. The results of the model seemed to suggest that air-sparged soil columns may be modeled as a composite of individual air channels surrounded by a MTZ. For a given air flow rate and air saturation, the VOC removal was found to be inversely proportional to the radius of the air channel. The approach taken provided conceptual insights on mass transfer processes during air sparging operations.
Associations of Postural Knowledge and Basic Motor Skill With Dyspraxia in Autism: Implication for Abnormalities in Distributed Connectivity and Motor Learning

Children with autism often have difficulty performing skilled movements. Praxis performance requires basic motor skill, knowledge of representations of the movement (mediated by parietal regions), and transcoding of these representations into movement plans (mediated by premotor circuits). The goals of this study were (a) to determine whether dyspraxia in autism is associated with impaired representational ("postural") knowledge and (b) to examine the contributions of postural knowledge and basic motor skill to dyspraxia in autism. Thirty-seven children with autism spectrum disorder (ASD) and 50 typically developing (TD) children, ages 8-13, completed (a) an examination of basic motor skills, (b) a postural knowledge test assessing praxis discrimination, and (c) a praxis examination. Children with ASD showed worse basic motor skill and postural knowledge than did controls. The ASD group continued to show significantly poorer praxis than did controls after accounting for age, IQ, basic motor skill, and postural knowledge. Dyspraxia in autism appears to be associated with impaired formation of spatial representations, as well as transcoding and execution. Distributed abnormality across parietal, premotor, and motor circuitry, as well as anomalous connectivity, may be implicated.
Pentaketide metabolites of melanin synthesis in the dematiaceous fungus Wangiella dermatitidis.

Melanin synthesis in the dematiaceous, polymorphic hyphomycete Wangiella dermatitidis, a human pathogen, was investigated by biochemical and physiological techniques. Mutants with a decrease or loss in melanin synthesis were induced and isolated. Melanin precursors were obtained from the mutants, purified, and then identified by comparison with authentic compounds from Verticillium dahliae. Isolation of scytalone, vermelone, flaviolin, and 1,8-dihydroxynaphthalene from the mutants of Wangiella dermatitidis, and cross-feeding of the mutants with those of Verticillium dahliae indicated that melanin synthesis in this organism took place by the pentaketide pathway. Melanin that formed in cell walls of an albino mutant treated with scytalone was identical in appearance to that in cell walls of the wild-type strain. This also suggested that pentaketide synthesis of melanin occurred in the fungus.
Durable remissions following prolonged plasma exchange in thrombotic thrombocytopenic purpura.

We evaluated the efficacy of prolonged plasma exchange (PEX) for attaining durable remissions in thrombotic thrombocytopenic purpura (TTP). A recent review using steroids or PEX in initial management showed an 80% response rate but produced a relapse rate of 67-84%. Records of 50 patients starting PEX treatment for TTP/HUS were reviewed to identify and select those whose course of treatment had ended over 1 year earlier, whether or not the result was satisfactory. Records were evaluated for outcome, especially remission associated with treatment by “prolonged” plasma exchange. “Prolonged” was defined as continuing PEX beyond the stage where a normal platelet count was attained and until evidence of hemolysis was “minimal or at least compensated.” If disease activity as judged by the criteria of hemolysis became accelerated or resumed, PEX was increased by volume of FFP (e.g., from 3 to 4 L) or rate (from less than daily to daily). Of 50 consecutive patients treated by PEX for TTP/HUS there were 40 cases after which at least one year had passed since the end of treatment. These 40 patients were evaluated for the results of treatment by PEX. Eight failed to achieve remission, dying in hospital within 1 month of admission. Twenty-eight achieved remission, sustained for 1 year or more in all. These are the reasons for our enthusiasm about this report. Four achieved remission lasting less than 1 year. Splenectomy was performed to obtain a sustained remission in one patient following administration of three 2 mg doses of vincristine and two relapses. The second was discharged with an adequate platelet count, but had ongoing hemolytic anemia and had to be retreated as an early relapse. The third, a mitomycin-induced TTP, had an early relapse which responded to additional PEX. The fourth was a late relapse. Our response rate of 80% is not higher than that of recent reviews. However, the relapse rate of 9% with prolonged plasma exchange is three times better than the average relapse rate of 27% from the 20 previous reports in the literature over the same period (Onundarson et al., Arch Int Med 152:761–766, 1992). We attribute this benefit to a strategy of continuing to perform plasma exchange on a tapering, alternating day schedule until disease activity is minimal as defined by criteria of hemolysis. Since relapses are often as devastating as the original episode, the treatment plan described is recommended.
Sequential prolactin evaluation of a “cured” patient with recurrence of prolactinoma

Abstract Several investigators have suggested that prolactin secretion in some subjects with hyperprolactinemia associated with pituitary macroadenomas may have a resistance to the prolactin inhibitory hormone, dopamine. This report describes a male subject with a prolactinoma whose preoperative evaluation demonstrated a resistance of prolactin release to inhibition by dopamine. Evaluation of prolactin secretion from monolayer culture of his tumor also revealed a resistance to inhibition by dopamine. Four months postoperatively, normal serum prolactin levels and a normal maximal inhibition of prolactin to a dopamine infusion of 0.04 μg/kg/minute suggested surgical cure. However, a 24-hour prolactin sampling revealed blunted nocturnal augmentation of prolactin release, an early escape of inhibition of prolactin release at 150 minutes from a 0.04 μg/kg/minute dopamine infusion, and abnormal prolactin response to a low-dose (0.004 μg/kg/minute) dopamine infusion. Hence, persistent abnormalities in prolactin secretory dynamics were noted with more extensive testing in this patient when he was thought to have been cured. One year postoperatively, the hyperprolactinemia recurred, prolactin release was markedly resistant to dopamine, and an abnormal 24-hour prolactin profile of release was present. Thus, resistance of prolactin secretion to inhibition by dopamine was present in this patient with a prolactinoma. Additionally, an abnormal prolactin response to dopamine was noted to precede the development of hyperprolactinemia with tumor recurrence.
A Remark on Stirling’s Formula

We shall prove Stirling’s formula by showing that for n=1, 2,… $$n! = \sqrt {2\pi } {n^{n + 1/2}}{e^{ - n}} \cdot {e^{{r_n}}}$$ (1) where rn satisfies the double inequality $$\frac{1}{{12n + 1}} < {r_n} < \frac{1}{{12n}}.$$ (2) .
Volumetric Titrations Using Electrolytically Generated Reagents for the Determination of Ascorbic Acid and Iron in Dietary Supplement Tablets: An Undergraduate Laboratory Experiment

An undergraduate laboratory experiment for the volumetric quantitative analysis of ascorbic acid and iron in dietary supplement tablets is presented. Powdered samples of the dietary supplement tablets were volumetrically titrated against electrolytically generated reagents, and the mass of dietary reagent in the tablet was determined from the volume of potassium hydrogen phthalate solution used as a primary standard. Proposed electrolysis cell was directly powered by a 9 V battery eliminating the requirement of a coulometer. Students use this method to quantify the active ingredient in dietary supplement tablets: iron and ascorbic acid (vitamin C). The experiment is suitable for the undergraduate quantitative analysis laboratory.
Reflection and Transmission of Radiation by Metal Films and the Influence of Nonabsorbing Backings

A set of equations is presented for the reflection and transmission of normally incident radiation by absorbing (metal) films on nonabsorbing backings.Using these equations, the results of two different methods of calculation of the reflection and transmission coefficients of a thick nonabsorbing plate are shown to be practically identical, both with and without an absorbing (metal) film on one surface of the plate. One of these methods involves the addition of intensities of the multiple reflections from the two surfaces of the plate. The other method is a rigorous calculation involving solution of the boundary condition equations (amplitude addition) for small areas followed by intensity averaging over the whole plate.In order to calculate optical constants of a metal film on a thick nonabsorbing backing, the much simpler method of intensity addition of internal reflections in the backing may usually be applied.
The relationship between land use and emerging and legacy contaminants in an Apex predator, the bottlenose dolphin (Tursiops truncatus), from two adjacent estuarine watersheds.

Abstract Background Persistent organohalogen contaminant (POC) exposure is of concern in marine mammals due to the potential for adverse health effects. Studies have examined POCs in marine mammals on a regional scale; however, limited data exists on POC concentrations relative to land use and watersheds. Objective Examine geographical variation of POC concentrations in bottlenose dolphins as it relates to land, and watershed, use. Methods POC (PCBs, DDTs, and PBDEs) concentrations were measured in blubber of bottlenose dolphins ( n = 40) sampled in estuarine waters near Charleston, SC. Photo-identification sighting histories were used to assess the dolphins′ use of estuarine waters in two adjacent watersheds (Cooper Subbasin and Stono Subbasin) in the study area and to determine land use (developed, forested, agriculture, and wetland) associations. Results Dolphins with ≥75% of their sightings in the Cooper Subbasin, which is characterized by a higher degree of developed land use, exhibited higher levels of PCBs, PBDEs, and total pesticides than those with ≥75% of their sightings in the Stono Subbasin. Observed differences were significant for ΣPBDEs and ΣDDTs/ΣPCBs ratio. Significant positive correlations were observed between ΣPBDEs and developed land use and between ΣDDTs/ΣPCBs and wetland land use. A significant negative correlation was observed between ΣDDTs/ΣPCBs and developed land use. Conclusion The spatial pattern of PBDEs and the ΣDDTs/ΣPCBs detected in dolphin blubber was shown to vary significantly with adjacent watersheds and land use associations.
Emotional Issues in Teaching Science: A Case Study of a Teacher's Views

Science teaching environments are social environments, and teachers’ emotions interact with their science teaching in powerful ways. To value the teacher is to value the whole person, not just the intellect. In this paper, a theorization of teacher emotion in science teaching is developed which illustrates the role of emotion in establishing and maintaining self-esteem in science teaching situations. From the standpoint of social-constructionist theory of emotion, it is argued that emotion is a social construction within social relationships. Arising from this view, are the emotions of intellectual excitement, frustration and shame that play a key role in the development of self-esteem. The dynamics of these emotions, in the context of experiences of success and failure, may dispose teachers to act positively or negatively towards science teaching. The theorisation developed is illustrated in the emotional experiences of an elementary school teacher in an early childhood science classroom. These experiences indicate that emotion is constitutive of teaching, and merits greater consideration in science teaching.
Posner’s Economic Model and the Decision to Appeal

Among those at the forefront of the attempt to restrict the growing appellate caseload has been legal scholar and federal judge Richard Pasner. Posner proposed a method, based upon economic assumptions, that he argues will liberate the appellate courts from the deluge of recent civil appeals. Because Posner’s model has played such an important theoretical and practical role in how we view the decision of losing litigants to appeal, the validity of the model and the real role of economic constraints have important implications. Using empirical research, I tested the validity of Posner’s model and I propose that economic considerations are not the primary motivations in losing litigants’ decision to appeal. I argue that, if Posner’s model is flawed, using this model may not only fail to decrease appellate case filings but could actually harm the legitimacy of the judiciary.
Biosynthesis and partial characterization of tear film glycoproteins. Incorporation of radioactive precursors by human lacrimal gland explants in vitro.

Abstract A system for studying the biosynthesis of tear glycoproteins by human lacrimal gland is described. Sufficient quantities of the newly-synthesized glycoproteins were obtained to permit some analyses of their physical and chemical properties. Separation of glycoproteins by gel filtration on Sephadex G-200 showed three major heterogeneous glycoprotein fractions with molecular weights of 580 000, 100 000 and 39 000 daltons. The sulfate, carbohydrate, and amino acid composition of each fraction was determined. The protein moieties were found to be acidic in nature. The smaller molecular weight fractions were moderately richer in carbohydrate [26% (w/w) than the higher molecular weight fractions (8% w/w)]. The low carbohydrate contents were comparable to those of plasma-type proteins. DEAE ion exchange chromatography of the major fraction also showed an elution pattern characteristic of plasma-type proteins. Using immunodiffusion techniques, at least five serum-type proteins, including IgA, IgG, albumin, transferrin and cerulo-plasmin were identified from the different fractions of the cultured lacrimal gland secretions. It appeared that human lacrimal gland secreted similar plasma proteins to those found in the tears. The significance of these identified tear proteins to the physiology of tears is discussed.