cssi/SciSciGPT-SciSciNet huggingface dataset:
Cell-bound autologous immunoglobulin in erythrocyte subpopulations from patients with sickle cell disease.

Previously, we have demonstrated a parallel between most-dense (bouyant density) sickle erythrocyte subpopulations and most-dense aged normal red cells in the organization of membrane components in the intact cell. The present study has addressed the possibility that a corresponding similarity may exist between most-dense sickled red cell subpopulations and aged normal erythrocytes in the development of membrane protein components that function as receptors for autologous immunoglobulin (Ig). Autologous IgG retained by density-fractionated erythrocytes has been estimated by a nonequilibrium 125I-protein A (Staphylococcus aureus) binding assay. Results show that most-dense sickle cell fractions contain more (2.7-fold and 1.8-fold, P less than .005) cell-bound IgG in comparison to younger sickle erythrocyte fractions sedimenting at low density. Parallel findings were obtained after similar analyses of normal (homozygous-A) erythrocyte fractions. Detection of the presence of specific IgG was also carried out by direct binding of fluorescein isothiocyanate-conjugated anti-human IgG to density-separated red cell fractions followed by analyses of the fluorescent cell populations by flow cytometry. Results showed significantly higher levels of IgG bound to most-dense (12.1% +/- 2.5% and 8.8% +/- 0.5%-) sickle red cell subpopulations (P less than .005) in comparison to younger sickle erythrocyte fractions sedimenting at low densities (3.8% +/- 0.32% and 4.7% +/- 1.6% IgG-positive red cell subpopulation). These results indicate that some of the same membrane changes that occur at about 120 days in normal red cells are also apparent in the chronologically younger (life span in vivo, ten to 40 days) sickle erythrocyte. The increased retention of IgG by most-dense irreversibly sickled cell-enriched fractions in comparison to least- dense reversibly sickled cells or pre-irreversibly sickled erythrocyte fractions, suggests that alterations in the topography of the sickle cell membrane during the transformation in vivo to the most-dense irreversibly sickled cell morphology may produce the unmasking of cryptic antigenic sites. In addition, these findings may indicate that opsonization of specific erythrocyte subpopulations may play a role in the pathophysiology of sickle cell disease.
Using Kali Linux Security Tools to Create Laboratory Projects for Cybersecurity Education

Cybersecurity education is an integral part of many undergraduate computer science curriculums. The draft ACM Computer Science Curricula 2013 recommends cybersecurity as a required body of knowledge for a typical computer science program. In the past few years, researchers and educators have developed various approaches and tools to implement laboratory projects for cybersecurity courses. Without doubt, cybersecurity education would be more effective, if we include hands-on activities to the relevant courses. This inclusion of hands-on activities can be achieved in various forms. Some institutions have the resources and expertise to set up physical laboratories for this purpose. Others use tools such as Second Life to create virtual classes and laboratories. This research reports our approach to hands-on activities for cybersecurity courses. In this approach, we use Kali Linux 2017.3 release pre-installed and preconfigured tools to create a set of laboratory projects. We also use VMware to setup virtual machine networks and then utilize security tools for hands-on part of our security courses. Finally, we report the details of the laboratory projects as well as their implementation.
Non-Iterative MDS Method for Collaborative Network Localization With Sparse Range and Pointing Measurements

Multi-agent localization is a basic requirement for many networked applications. The particular application to swarming unmanned aerial vehicles (UAVs) or munitions requires spatial coordination of agents, including the ability to assume and maintain a prescribed flight formation. An in-flight awareness of network morphology and node location is therefore needed. While global navigation satellite systems offer an attractive solution, signal occlusion, spoofing, and jamming present unacceptable vulnerabilities—particularly for mission-critical operations. Alternative network localization methods using inter-agent radio frequency ranging and Angle of Arrival have been well studied over the past 15 years, but existing algorithms are not well suited to fast-moving networks. Iterative methods tend to converge slowly. Faster noniterative multi-dimensional scaling (MDS) methods for range, bearing, or vector measurements have also been formulated. However, these MDS methods generally require the full pairwise inter-agent measurement matrix—placing a severe requirement on swarm connectivity and leading to low tolerance for missing or badly estimated measurements. Even vector-based MDS, which incorporates both range and direction constraints, is shown here to require 4-vertex connectivity to achieve perfect localization. Results from rigidity theory, however, suggest that a lower connectivity threshold should be sufficient to guarantee a unique configuration (up to translation and rotation). In contrast, our proposed “vertex resequencing” and “edge resequencing” techniques further lower the vertex-connectivity threshold to 3 and 2, respectively. These localization techniques, which extend vector-based MDS with Nystrom approximation, prescribe a graph-based kernel sampling scheme and weighted coordinate reconstruction that suppress the effect of missing measurements.
Heteroepitaxial growth of strained multilayer superconducting thin films of Nd 1.83 Ce 0.17 CuO x /YBa 2 Cu 3 O 7-δ

Heteroepitaxial growth of strained multilayer thin films of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}/Nd{sub 1.83}Ce{sub 0.17}CuO{sub {ital x}} by pulsed-laser deposition is reported. The coherency strain results in biaxial compression of the tetragonal Nd{sub 1.83}Ce{sub 0.17}CuO{sub {ital x}} layers, whereas the biaxial tension in the YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} layers removes the orthorhombic distortion and makes the unit cell isotropic in the basal plane ({ital a}={ital b}). Depending on their oxygen content, either the YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} or the Nd{sub 1.83}Ce{sub 0.17}CuO{sub {ital x}} layers are superconducting in these multilayers. The strain-induced structural modification has a significant influence on the superconducting transition temperature of the YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} layers.
Journal Update from the Editor-in-Chief.

I wish to take this opportunity to highlight our achievements with the International Journal of Gynecological Cancer . We are extremely proud of the great progress seen over the past 7 months by our new Editorial Team. To this end, we would like to share these accomplishments with our readers and
Cryptic, solo acylhomoserine lactone synthase from predatory myxobacterium suggests beneficial contribution to prey quorum signaling

Considered a key taxon in microbial communities, myxobacteria exist as coordinated swarms that utilize an excreted combination of lytic enzymes and specialized metabolites to facilitate predation of numerous microbial phyla. This capacity to produce biologically active metabolites and the associated abundance of natural product biosynthetic pathways contained within their genomes have motivated continued drug discovery efforts from myxobacteria. Of all the biosynthetic gene clusters associated with myxobacteria deposited in the antiSMASH database (~1,000 total), only one putative acylhomoserine lactone synthase, agpI, was observed in genome data from the myxobacterium Archangium gephyra. Without an acylhomoserine lactone (AHL) receptor also apparent in the genome of A. gephyra, we sought to determine if AgpI was the first example of an orphaned AHL synthase. Herein we report the bioinformatic assessment of AgpI and discovery of a second myxobacterial AHL synthase from Vitiosangium sp. strain GDMCC 1.1324. During axenic cultivation conditions, no detectible AHL metabolites were observed in A. gephyra extracts. However, heterologous expression of each synthase in Escherichia coli provided detectible quantities of 3 AHL signals including 2 known AHLs, C8-AHL and C9-AHL. These results suggest that A. gephyra AHL production is dormant during axenic cultivation conditions and requires an unknown external cue for activation. The orphaned AHL synthase, AgpI, is the first to be reported from a predatory myxobacterium, and predator production of prey quorum signals provides unique insight into interspecies crosstalk within polymicrobial communities.
A Comprehensive Approach to Algorithmic Machine Sorting of Library of Congress Call Numbers

This paper details an approach for accurately machine sorting Library of Congress (LC) call numbers which improves considerably upon other methods reviewed. The authors have employed this sorting method in creating an open-source software tool for library stacks maintenance, possibly the first such application capable of sorting the full range of LC call numbers. The method has potential application to any software environment that stores and retrieves LC call number information.
OPTIMUM DESIGN METHODS FOR STRUCTURES

A review is given of the methods for the optimum design of structures composed of perfectly plastic materials. The methods are extended to other materials and a brief discussion of the limitations of the methods is given.
Shared Reading Extratextual Talk With Children With Autism Who Have Spontaneous Speech

Shared reading is a developmentally appropriate practice that supports children’s emergent literacy and language development. Participation in shared reading, however, may be compromised for childr...
Ectopic salivary tissue of the mandibular condyle: A case report and review of the literature

Abstract Primary ectopic salivary tissue within the mandible (salivary choristoma) is a rare phenomenon. Previous cases of mandibular intraosseous salivary tissue usually arise due to salivary gland tissue perforation through the lingual cortical plate in the posterior body/angle region of the mandible. We present a case report of a 22-year-old, otherwise healthy, woman who presented with an asymptomatic radiolucent lesion of the left condylar neck and head. The pathology was discovered on routine radiographs. A surgical approach utilizing a vertical ramus osteotomy through a submandibular incision was utilized to explant the condyle with a ramus segment. An extracorporeal removal of the pathology was performed and the defect was grafted prior to reimplantation of the segment which was stabilized with bone plates and screws. Histopathologic analysis revealed ectopic salivary tissue consistent with an intraosseous salivary gland choristoma. This report will discuss clinical findings, surgical intervention, and potential mechanisms to explain the etiology of ectopic salivary tissue within the mandible.
Suppressing irradiation induced grain growth and defect accumulation in nanocrystalline tungsten through grain boundary doping

Abstract Deliberately designed nanostructured materials containing a high density of dopant stabilized interfaces provide energetically favorable sites for the annihilation of defects that form within the crystalline matrix due to irradiation. In this study, we explore the role of dopants on the mechanisms governing this behavior in a nanocrystalline W alloy doped with 20 at.% Ti using heavy ion irradiation experiments. Defect evolution is mapped in situ up to the saturation dose and bridged to extreme dose behavior using ex situ measurements with microstructural analysis focused on quantifying both the defect state and the impact of ion irradiation on the nanocrystalline grain structure. Compared with a nominally pure nanocrystalline W film, the W-20 at.% Ti alloy exhibits smaller defect loops and a delayed saturation dose with a period of irradiation induced grain growth occurring during transient damage accumulation. Microstructural evolution is modeled in the context of cascade-induced thermal spikes and reveals that the alloy evolves to a much finer nanocrystalline grain size relative to the predictions for pure W, indicative of Ti stabilizing the nanostructure against irradiation induced grain growth. In situ mapping of defect evolution during the growth of a single grain confirms the correlation between the global defect density trends and evolution of the microstructure, thus providing insights into the effect of Ti on the grain boundary sink strength through the transient defect accumulation and recovery stages.
Hopes, fears, and rumors: Medical students and the general surgery clerkship.

Abstract Background Surgical educators have worked to manage the hopes and fears as well as the recurring rumors that plague the surgical clerkship. It is not known if this has effected change over time. Methods We gathered information on hopes, fears, and rumors during our clerkship orientations from 2017 to 2019 using anonymous polling software with real-time feedback. We analyzed 468 responses using qualitative content analysis. Results Students hoped for practical skills acquisition, self-improvement, and understanding the surgical profession. They feared lack of time and knowledge, burnout, mistreatment, and subjective evaluation. Rumors included negative perceptions of surgical culture work environment, and fear of mistreatment despite clerkship changes intended to allay these fears. Conclusion Students starting surgery clerkships hope to gain surgical and clinical skills but concerns about surgical culture and mistreatment appear to remain unchanged despite structural improvements in the clerkship experience. Surgeons should look beyond the clerkship itself to change these perceptions.
Seismic fragility and vulnerability curves for the Italian residential building stock

In Italy, the recent regulatory and legislative developments relevant to the seismic risk mitigation of the existing building stock aim to propose tax deductions and simple but reliable approaches ...
Review of the Security of Backward-Compatible Automotive Inter-ECU Communication

Advanced electronic units inside modern vehicles have enhanced the driving experience, but also introduced a myriad of security problems due to the inherent limitations of the internal communication protocol. In the last two decades, a number of security threats have been identified and accordingly, security measures have been proposed. While a large body of research on the vehicular security domain is focused on exposing vulnerabilities and proposing counter measures, there is an apparent paucity of research aimed at reviewing existing works on automotive security and at extracting insights. This paper provides a systematic review of security threats and countermeasures for the ubiquitous CAN bus communication protocol. It further exposes the limitations of the existing security measures, and discusses a seemingly-overlooked, simple, cost-effective and incrementally deployable solution which can provide a reasonable defense against a major class of packet injection attacks and many denial of service attacks.
Protocol to measure contraction, calcium, and action potential in human-induced pluripotent stem cell-derived cardiomyocytes.

Multiple strategies have been developed to efficiently differentiate human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Here, we describe a protocol for measuring three key functional parameters of hiPSC-CMs, including contractile function, calcium (Ca2+) handling, and action potential. For complete details on the use and execution of this protocol, please refer to Zhang et al. (2021).
Marine phytoplankton functional types exhibit diverse responses to thermal change.

Marine phytoplankton generate half of global primary production, making them essential to ecosystem functioning and biogeochemical cycling. Though phytoplankton are phylogenetically diverse, studies rarely designate unique thermal traits to different taxa, resulting in coarse representations of phytoplankton thermal responses. Here we assessed phytoplankton functional responses to temperature using empirically derived thermal growth rates from four principal contributors to marine productivity: diatoms, dinoflagellates, cyanobacteria, and coccolithophores. Using modeled sea surface temperatures for 1950–1970 and 2080–2100, we explored potential alterations to each group’s growth rates and geographical distribution under a future climate change scenario. Contrary to the commonly applied Eppley formulation, our data suggest phytoplankton functional types may be characterized by different temperature coefficients (Q10), growth maxima thermal dependencies, and thermal ranges which would drive dissimilar responses to each degree of temperature change. These differences, when applied in response to global simulations of future temperature, result in taxon-specific projections of growth and geographic distribution, with low-latitude coccolithophores facing considerable decreases and cyanobacteria substantial increases in growth rates. These results suggest that the singular effect of changing temperature may alter phytoplankton global community structure, owing to the significant variability in thermal response between phytoplankton functional types. Phytoplankton communities are important players in biogeochemical processes, but are sensitive to global warming. Here, a meta-analysis shows how the varied responses of phytoplankton to rising temperatures could potentially alter growth dynamics and community structure in a future ocean.
Quantitative Determination of Low Molecular Weight Ribonucleic Acids in Rat Liver Microsomes

Abstract Analysis by type of the RNA of microsomes and of ribosomes was performed by sucrose density gradient centrifugation and by chromatography on Sephadex G-200. Microsomal RNA consists of high molecular weight RNA, 5 S RNA, and transfer RNA in the proportions of 93%, 1.6%, and 5.9%, respectively. RNA of ribosomes of molecular weight less than about 150,000 differed from that of microsomes only in the content of tRNA. Incubation of microsomes at 37° in solutions containing sodium dodecyl sulfate resulted in breakdown of high molecular weight RNA.
OSTEOID OSTEOMA AS AN ATYPICAL SOLITARY LUCENT EPIPHYSEAL LESION IN A CHILD

A previously healthy 5-year-old boy was admitted to the hospital with a nine-month history of diurnal and nocturnal pain in lower legs, particularly in the right knee, partially relieved by NSAIDs. Routine laboratory tests and an initial radiographic evaluation six months ago were normal. Due to persistent pain and limping repeated radiographs identified subtle lytic lesion with diffuse medullary sclerosis of the medial femoral condyle epiphysis (Fig1). MRI of the knee presented T2 hyperintense lesion with a thin hypointense rim consistent with sclerosis and perilesional bone marrow edema. After paramagnetic contrast application the lesion revealed a ring of enhancement (Fig. 2 a, b). A bone scan showed no focal uptake. Imaging char-
A critical analysis, with appropriate controls, of gastric acid and pepsin secretion in clinical esophagitis

Because esophagitis is a presumed "acid-peptic" disease, fasting gastric contents (volume and acid and pepsin concentrations) and basal and pentagastrin-stimulated acid and pepsin outputs were studied in 155 patients with endoscopically defined (and graded 1-4) esophagitis and 508 control patients without esophagitis. Basal pepsin and maximal acid and pepsin outputs were lower in the patients with esophagitis than in those without esophagitis. In further analysis, the patients were subdivided into three categories, duodenal ulcer, nonulcer with no disease other than esophagitis, and postgastric surgery, because these categories affect gastric secretion independently of esophageal disease and in the rank order given. Each category was subdivided by sex, because men secreted more than women. Within each category there was no systematic difference in fasting, basal, or maximal gastric acid or pepsin secretion between patients with and patients without esophagitis. Severity of esophagitis was not related to any secretion parameters. Hiatal hernia was present in 50% of patients with esophagitis vs. 15% of controls without the condition (P less than 0.01); however, this did not independently influence the gastric secretion findings. Lower esophageal sphincter pressure was also measured in 62 of the patients, 31 with and 31 without esophagitis. Below 10 mm Hg (incompetent sphincter), 9 of 10 patients had esophagitis but accounted for only less than 30% of the patients with esophagitis, whereas none of 11 patients with basal acid output of less than 0.1 mEq/h and lower esophageal sphincter pressure of greater than 10 mm Hg had esophagitis. Because neither the composition of gastric juice nor basal or stimulated gastric acid or pepsin output could be correlated to the presence or severity of esophagitis, factors other than amount or composition of gastric juice per se must be responsible for susceptibility to esophagitis.
Preliminary Results from a Search for Disoriented Chiral Condensates at MiniMax

We report on the progress of a search for disoriented chiral condensates (DCCs) in the far forward region at sqrt(s)=1.8 TeV. MiniMax is a small collider experiment situated at the C0 interaction region of the Tevatron and has been designed to measure the ratio of charged to neutral pions produced at eta near 4.1. The distribution of this ratio is expected to be very different for the generic binomial and DCC particle production models. We present a method used for the search using the factorial moments of particle generating functions, which can be extracted directly from the data. A preliminary comparison of robust ratios of measured values and those expected from the different models is also presented.
The PNA project

The Personal Nutrition Assistant (PNA) Project is a join effort involving faculty and students from two universities. The project was initially funded with a seed grant that supported cooperative efforts between these institutions. The goal of the PNA Project was the creation of a working prototype of a web-based system that assisted individuals in performing a nutritional analysis of their daily diet and made the results available via the web to their health care professionals. Further, we wanted the data entry to be easy and quick. We had providing a system that helped clients performing daily diet data entry and analysis in about 15 to 20 minutes. As stated above, the system produced through the initial grant was a working prototype, a system that demonstrated the feasibility of the approach. Further, since the daily diets are stored on the web the results could be viewed by the clients' dietician or health care provider, providing much greater feedback from the clients to the health care professional than is normally achieved. The initial system was so successful that nine local medical centers started using the working prototype with their patients. The system will form the basis of Senior Projects starting in the 2000-2001 academic year, and is expected to support additional projects in the years to come. This paper reports on the first projects, which were designed to upgrade this system from working prototype status to production level.
Authority and Compulsion in Legal-Historical Method

Case law is often used as evidence of a political action, similar to a pamphlet or speech. Yet, legal decisions are different from other sources in that when they function as precedent they have authority not only in the case at hand, but also in similar future cases. Recovering and using case law in the process of doing qualitative research is then inherently normative in the sense that researchers’ actions may influence the outcome of future legal cases. This article argues that case law in the common law world is a unique type of source presenting normative entanglements and challenges not found in other historical documents, and that these normative issues have been overlooked because the concept of authority has received little attention in qualitative methodology. Consideration of the authority of our source material helps us to understand not only the context of the original source, but also to anticipate and appreciate the future uses to which others may put our work.
Optimizing the Power of Choice: Supporting Student Autonomy to Foster Motivation and Engagement in Learning.

Choice plays a critical role in promoting students' intrinsic motivation and deep engagement in learning. Across a range of academic outcomes and student populations, positive impacts have been seen when student autonomy is promoted through meaningful and personally relevant choice. This article presents a theoretical perspective on the motivational role of choice in learning, based on self-determination theory. Theoretical principles and current research on student motivation and engagement are described. Conditions under which choice promotes students' intrinsic motivation are then presented.
Effect of disease state on ionization during bioanalysis of MK-7009, a selective HCV NS3/NS4 protease inhibitor, in human plasma and human Tween-treated urine by high-performance liquid chromatography with tandem mass spectrometric detection.

Abstract HPLC–MS/MS methods for the determination of a Hepatitis C NS3/NS4 protease inhibitor (MK-7009) in human plasma and Tween-treated urine were developed and validated over the concentration range 1–1000 ng/mL and 0.2–100 μg/mL respectively. A stable isotope labeled internal standard (ISTD), D4-MK-7009, was employed. Analytes were chromatographed by reversed phase HPLC and quantified by an MS/MS system. Electrospray ionization in the positive mode was employed. Multiple reaction monitoring of the precursor to product ion pairs m/z 758.6 → 637.4 MK-7009 and m/z 762.5 → 637.4 ISTD was used for quantitation. Analyte and internal standard were extracted from 250 μL of plasma using an automated 96-well liquid–liquid extraction. Plasma pH adjustment prior to extraction minimized ionization suppression in plasma samples from patients with Hepatitis C. The urine method involved direct dilution in the 96-well format of 0.020 mL Tween-treated urine. These methods have supported several clinical studies. Incurred plasma sample reanalysis demonstrated adequate assay reproducibility and ruggedness.
XAspects: an extensible system for domain-specific aspect languages

Current general aspect-oriented programming solutions fall short of helping the problem of separation of concerns for several concern domains. Because of this limitation good solutions for these concern domains do not get used and the opportunity to benefit from separation of these concerns is missed. By using XAspects, a plug-in mechanism for domain-specific aspect languages, separation of concerns can be achieved at a level beyond what is possible for object-oriented programming languages. As a result, XAspects allows for certain domain-specific solutions to be used as easily as a new language feature.
Colorimetric Determination of Ethambutol

A method has been developed for the separation and determination of ethambutol using cupric ion as a chelating agent. The method is sensitive for routine assay and simple to carry out. The effect of time on color stability, the reproducibility of the method, and the determination of the complexation ratio have been investigated.
The Fetus as Patient

Our subject relates three social forces that influence the ethos, the structure, and the behavior of society: law, ethics, and science. The three constantly interact and influence one another.
"Crossing Brooklyn Ferry": The Shaping Imagination

Presents a brief reading of "Crossing Brooklyn Ferry" that shows how Whiman's "fascination for panoramas, dioramas, and dime museums" informs the effects achieved in the poem.
Relation of Organizational Citizenship Behavior and Locus of Control

The relation of organizational citizenship behavior and locus of control was assessed in a sample of 286 college students (52% men; M age = 24 yr.) who worked an average of 26 hr. per week. Measures were Spector's Work Locus of Control Scale and Podsakoff, et al.'s Organization Citizenship Behavior scale. Hierarchical multiple regressions indicated positive association of scores on work locus of control with scores on each of the four tested dimensions of organizational citizenship, as well as total organizational citizenship behavior.
1587 ATRIOPEPTIN: A POWERFUL NATRIURETIC IN RATS WITH RENAL FAILURE

Atriopeptins are recently described peptides in cardiac atria which are natriuretic and vasodilatory. We have found that a 30 min infusion of Atriopeptin III (AP III), a 24 amino acid peptide, produces a 9-fold increase in the fractional excretion of sodium (FENa), with initial increases in both glomerular filtration rate (GFR) and renal plasma flow. To determine whether atriopeptins might be efficacious in the volume expansion of chronic renal failure, 250 g Sprague-Dawley rats underwent 5/6 nephrectomy. Clearance studies were performed after 4 days or 4 weeks of uremia. After a baseline period of 20 min, AP III was infused for 30 min at 0.5 μg/kg/min. Responses in GFR and FENa are shown below, (mean ± SEM) The responses to atriopeptins in rats with chronic renal failure far exceed those in the normal rat. Not only is there an increase in GFR that remains elevated throughout the infusion, but the magnitude of the natriuresis (FENa=24%) is striking. This peptide promises to be helpful in managing the volume overload of patients with chronic renal failure.
Amino acid requirements of normal and malignant human cells in tissue culture.

Abstract Three tissue culture cell lines deriving from normal human tissue (liver, conjunctiva, and intestine) and two lines deriving from human cancer [KB (nasopharynx), and J-111 (monocytic leukemia)] have been examined with respect to their amino acid requirements in comparison with those of a HeLa cell and a mouse fibroblast. With the possible exception of tryptophan, all seven cell lines required the same amino acids (arginine, cystine, glutamine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tyrosine, valine); and in the absence of any one of these 12, cytopathogenic changes developed which culminated in the death of the cell. The provision of non-essential amino acids, purines, pyrimidines, and NH 4 + had a glutamine-sparing effect, but did not eliminate the need for this amino acid. Extremely high and nonphysiological concentrations of glutamic acid (20 mM ) did, however, substitute for glutamine. It is not yet clear whether tryptophan is similarly essential for survival and growth, or whether it is merely growth stimulatory for some of the five cell lines here studied. The concentration of the individual amino acids necessary for optimum growth varied somewhat among the six strains; but there were not significant or consistent differences in this respect between the lines deriving from normal and from malignant tissues.
Use of Peer Instruction to Train a Complex Photocopying Task to Moderately and Severely Retarded Adolescents.

Abstract Three severely retarded adolescents were taught a 26-step photocopying task by a moderately retarded peer within a multiple-baseline design. The peer trainer was taught to demonstrate the target task to the trainees, contingently praise correct responses, and to provide correction for errors. During baseline, the trainees were unable to perform the photocopying task correctly. Following instruction by the peer trainer, all trainees showed immediate improvement and completed at least 80 percent of the steps correctly. Two of the three trainees maintained their performance over a four week period and all trainees generalized their performance to a second photocopying task. In addition, the peer trainer accurately prompted, corrected, and praised performance.
Optimism Invites Deception

Recent literature has focused on reputation as a mechanism for (partially) correcting information asymmetries that can exist in markets. Where sellers produce an output whose quality is not easily observed by buyers prior to sale, then sellers' reputation, based on past observations, can be used by consumers to prejudge quality. Consumers may pay a premium price for such firms, for whom a reputation is a valuable asset. In choosing quality anew each period, the prospect of future profits from this premium price may dissuade the firm from cheating on quality. This theory is developed in Klein and Leffler [1981], Shapiro [1982, 1983], Dybvig and Spatt [1983], Rogerson [1983], and Allen [1984]. This literature has presumed that the quality of firms' chosen inputs is perfectly correlated with the quality of their outputs; there is no noise in the production process. Indeed, adding noise to a reputation model would seem to be a trivial generalization; at first blush, we would expect the product of a firm that delivered high quality only 90 percent of the time to be worth roughly 90 percent of the value of the product of a firm that had perfect quality control. In this paper we investigate the pure-strategy equilibria of a rational expectations model that incorporates quality noise. We find that the market for high quality may not be sustainable in the presence of such noise (ruling out mixed strategies). Since consumers cannot observe the quality of a firm's inputs (assumed fixed and sunk), they must infer this quality from observed outputs. In equilibrium consumers' initial beliefs about the quality of the firm's inputs are determined by what they (correctly) predict to be the firm's strategy; observations of the output lead them to revise these beliefs in accordance with Bayes' law. If consumers are sure that a firm will purchase good inputs, then it pays the firm to "cheat," and purchase bad inputs, since
Structure—activity relationship studies on the toxicity of benzene derivatives: III. Predictions and extension to new substituents

The additivity model developed earlier for 65 substituted benzenes has been extended to 105 compounds for the fathead minnow system. Toxicity is predicted for 10 compounds not included in the original data set. Four new substituents have been evaluated and their toxicity contributions have been determined by regression analysis. For the whole data set, the following statistics were obtained for the 12—variable model: r=0.921, s=0.31, F=43. The order of toxicity contributions for all substituents now investigated is as follows: —NO2 ≈ —Cl > —Br > —CHO > —CH3 ≈ —F > —NH2 ≈ —CN > —OH ≈ —OCH3 > —COCH3. Also identified in these analyses is the additional toxicity conferred by the ortho—hydroxybenzaldehyde combination. Such a structural arrangement increases toxicity by 1.45 units over both the meta and para arrangements. For the 11 substituents, relationships have been sought between the toxicity contribution and physicochemical parameters, including partition coefficient (π) and electronic parameters, but no significant relation has been found. Also evaluated were five additional substituents for which there are few data. Approximate toxicity contributions are reported for these substituents.
Topological realization of transfer functions in canonical forms

This note presents a new signal-flow graph method for obtaining all canonical realizations of any single-input, single-output transfer function. The canonical realizations are represented by integer codes which can be generated with a simple computer program.
Bayesian reconstruction of contingency tables with partially categorized data

This paper suggests a Bayesian approach to the reconstruction of a 2 × 2 contingency table where some of the observations are only partially categorized and others are fully categorized. In contrast, most previous Bayesian and non-Bayesian analyses of the partially categorized data problem have been concerned with estimation of the parameters that generated the data. We show in an example that estimates may not be extremely sensitive to the weight placed on prior information relative to the sample data.
A theory for vortex rossby-waves and its application to spiral bands and intensity changes in hurricanes

In this paper we examine further the physics of vortex axisymmetrization, with the goal of elucidating the dynamics of outward-propagating spiral bands in hurricanes. the basic shysics is illustrated most simply for stable vorticity monopoles on an f-plane. Unlike the dynamics of sheared disturbances in rectilinear shear flow, axisymmetrizing disturbances on a vortex are accompanied by outward-propagating vortex Rossby-waves whose restoring mechanism is associated with the radial gradient of storm vorticity. Expressions for both phase and group velocities are derived and verified; they confirm earlier speculations on the existence of vortex Rossbywaves in hurricanes. Effects of radially propagating vortex Rossby-waves on the mean vortex are also analysed. In conjunction with sustained injection of vorticity near the radius of maximum winds, these results reveal a new mechanism of vortex intensification. the basic theory is then applied to a hurricane-like vortex in a shallow-water asymmetric-balance model. the wave mechanics developed here shows promise in elucidating basic mechanisms of hurricane evolution and structure changes, such as the formation of secondary eye-walls. Radar observations possessing adequate temporal resolution are consistent with the predictions of this work, though more refined observations are needed to quantify further the impact of mesoscale banded disturbances on the evolution of the hurricane vortex.
Into the CoSMoS: Single Molecule Analysis of Spliceosome Assembly and Activation

Excision of introns from pre-mRNAs is mediated by the spliceosome, a large, dynamic complex consisting of five small ribonucleoprotein particles (snRNPs) and scores of associated proteins. Current understanding of spliceosome assembly is based largely on the procession of stable complexes that can be resolved from in vitro splicing reactions. Such ensemble experiments have suggested a highly ordered, linear assembly pathway in which initial binding of U1 snRNP to the 5′ splice site is followed by stable U2 association with the branch site and subsequent U4/U5/U6 tri-snRNP and Nineteen Complex (NTC) addition to form the fully assembled spliceosome. Previously unknown, however, were the detailed forward and reverse kinetics of each assembly step, the extent to which branched and/or dead-end assembly pathways exist, and whether or not different introns utilize the same or alternate assembly pathway(s). We are now addressing these questions by combining yeast genetic engineering, chemical biology, and multi-wavelengthfluoresence microscopy to follow assembly of single spliceosomes in real time. Because no protein purification or reconstitution is required for such Colocalization Single Molecule Spectroscopy (CoSMoS), this experimental strategy should prove widely useful for mechanistic analysis of many other macromolecular machines in environments approaching the complexity of living cells.
New Synthetic Routes to Alkyl Monolayers on the Si(111) Surface1

Two new methods for the formation of Si−C monolayers from reactions with Si(111)−H are reported. Besides the photochemical method previously reported by Chidsey, Lewis acid-catalyzed hydrosilylation of alkenes and direct reaction of alkylmagnesium bromide produce a surface with similar chemical composition. These processes are demonstrated and compared using reactions of a C10 precursor. The surfaces are chemically stable and can be stored for several weeks without measurable deterioration. The availability of a variety of synthetic approaches leading to the same chemical product is key to the development of flexible surface synthetic strategies. It is expected that these approaches will underpin the development of stepwise solid-phase-like syntheses of more complex organic/bioorganic species on these surfaces.
Out of the armchair: a bioethics student's search for practical knowledge in Kenya.

This paper recounts the efforts of a Bioethics student to understand the experience of human subjects of medical research in Kenya. Although the endeavor resulted in more questions than answers, it served to highlight areas where the current system of protections has failed to secure the well-being of those involved. It concludes that, in addition to existing considerations, ethical review ought to include another kind of information: that which can be gained only from listening to the feelings and experiences related by subjects themselves.
ICON PURITY — TOWARD A FORMAL THEORY OF ICONS

In this paper, we give purity-preserving conditions for iconic operators, and present a formal definition of degree of icon purity by extending an icon system to a fuzzy icon system, based upon the theory of fuzzy sets. We also show an icon system can be modeled by means of an attribute grammar.
Magnetogasdynamic channel flows

The asymptotic behavior of small unsteady perturbations that are superposed on an equilibrium magnetogasdynamic channel flow is considered. Only those channels with slowly varying cross-sectional area and small characteristic width-to-length ratio are allowed, so that variations along the channel are typically much smaller than are those across the channel. Under these conditions and the provision that the current density inside the duct is small, a set of "quasi-one-dimensional" equations is obtained. From the resulting set of hyperbolic equations, the theory of characteristics provides certain compatibility relations that describe the behavior of small disturbances of the steady channel flow, which are caused by some local pressure fluctuation. Two distinct wave motions are present within the channel, and the asymptotic behaviors of both are examined with the use of the aforementioned compatibility relations. It is shown that, under certain conditions on the magnetic-field distribution, wave motions that lead to shock formation in ordinary gasdynamic flow will attenuate because of the action of the magnetic field. Therefore, an instability is no longer predicted, and the possibility of a stable or shockless flow, due to the action of a suitably placed magnetic field, is revealed. a A B c d E H h 3 Mc p p
Variations of ground radon concentrations with activity of Kilauea Volcano, Hawaii

Measurements of the concentration of the radioactive gas radon, in particular relative areal variations in Rn outgassing (mainly isotopes 222Rn, t1/2 = 3.82 days and 220Rn, t1/2 = 54.5 s), at shallow ground depths (30 cm) are being used extensively in Hawaii in the exploration for geothermal resources1,2. Zones showing a greater than usual degree of Rn ground gas outgassing have delineated areas of anomalous subsurface heat and increased permeability. The patterns of outgassing suggest that thermally induced ground gas convection systems have developed1. Nine measurement stations have been established on the upper east rift of Kilauea volcano along the Chain of Craters Road (Fig. 1) to observe: (1) temporal variations in Rn outgassing; (2) relationship between Rn outgassing and variations in se ism i city; and (3) whether this technique can assist in understanding the ‘plumbing’ of Kilauea and whether monitoring of a larger number of stations could assist in indicating pre-eruptive activity. These nine stations, initially included in a summit-wide survey (August–September 1978), were re-established in Oktober 1979 because of the increased seismic activity within the upper east rift. Fortuitously, a small eruption of Pauahi Crater occurred on 16–17 November 1979 at the end of the first one-month period of measurement. The present results indicate that the Rn concentration increases before and during seismic events, then decreases before returning to a ‘normal’ value.
Fascia Laxa Patch Graft in Glaucoma Tube Surgery

Purpose: To determine if using human cadaveric fascia lata grafts to cover glaucoma implant tubes is safe and effective. Methods: All patients who underwent glaucoma implant surgery at the Doheny Eye Institute between July 1993 and September 1993 received a fascia lata patch graft to cover the subconjunctival portion of the tube. These patients were followed prospectively for clinical signs of conjunctival breakdown, graft melt, tube erosion, graft-related inflammation, infection, and graft-related complications. Results: Twenty-two eyes of 21 patients were followed for a mean of 19 months. All eyes tolerated the fascia lata grafts well without clinical evidence of graft-related conjunctival, scleral, or intraocular inflammation. No tube erosion or melting of the graft was observed in the study group. Conclusion: Preserved donor fascia lata was well tolerated as a grafting material in glaucoma implant surgery. No clinical signs of graft rejection, foreign body reaction, tube erosion, or graft melt were observed in the study group during the follow-up period.
A Combustion Bomb Study of the Hydrocarbon Emissions from Engine Crevices

Abstract Two combustion bombs manufactured from a Ford 1.6L Escort production engine were used to determine the effects of engine crevice volumes on hydrocarbon emissions. Since these combustion bombs were used as static reactors, the results cannot be directly applied to an operating engine but they focus attention on the major hydrocarbon-producing crevices in an actual engine geometry. During Ihis propane-fueled experiment, the crevices were sequentially filled with epoxy or viton rubber, and after filling each crevice, the exhaust hydrocarbon emission was measured by gas chromatography. This provided a quantitative measurement of the hydrocarbon emission from each crevice. For these reactors, the ring-pack crevices produced approximately 80.5 percent of the total scaled hydrocarbon emission, while the head gasket and spark plug threads produced approximately 12.5 percent and 5 percent, respectively. All other hydrocarbon sources produced less than 2 percent of the total scaled hydrocarbon emissionfrom...
Engineering Education for Competitive International Economy

The sources of research funding for U.S. academic institutions are examined through the past two decades. Of particular interest has been the flow of funding to engineering schools. Since the end of World War II most of the funding to our engineering schools has come from federal government sources. It is argued that the research projects carried out with federal funding support are much more science oriented than the research (and development) projects that are supported by industry funds. This science orientation in engineering research has greatly influenced the way engineering faculties view undergraduate education. Because of this science influence, entry‐level engineers in the U.S. enter the work force with little background in professional and related business subjects. It is postulated that this lack of professional training for our entry‐level engineers has significantly contributed to the nation's long‐term decline in the global competitiveness of U.S. technology‐based industries.
A new method for determining radiation fields in finite, conservative, isotropically scattering media bounded by a Lambert's law reflector

Abstract The integral equation for the source function for the case in which uniform parallel rays illuminate a slab, with conservative isotropic scattering, the slab being bounded by a Lambert's law reflector, is reduced to a Cauchy system well-suited for computational solution. A noteworthy feature is that the auxiliary functions introduced involve only functions of one angular argument.