cssi/SciSciGPT-SciSciNet huggingface dataset:
Using Students’ Conceptual Models to Represent Understanding of Crosscutting Concepts in an NGSS-Aligned Curriculum Unit About Urban Water Runoff

Recent science education reforms, as described in the Framework for K-12 Science Education (NRC, 2012), call for three-dimensional learning that engages students in scientific practices and the use of scientific lenses to learn science content. However, relatively little research at any grade level has focused on how students develop this kind of three-dimensional knowledge that includes crosscutting concepts. This paper aims to contribute to a growing knowledge base that describes how to engage students in three-dimensional learning by exploring to what extent elementary students represent the crosscutting concept systems and system models when engaged in the practice developing and using models as part of an NGSS-aligned curriculum unit. This paper answers the questions: How do students represent elements of crosscutting concepts in conceptual models of water systems? How do students’ representations of crosscutting concepts change related to different task-based scaffolds? To analyze students’ models, we developed and applied a descriptive coding scheme to describe how the students illustrated the flow of water. The results show important differences in how students represented system elements across models. Findings provide insight for the kinds of support that students might need in order to move towards the development of three-dimensional understandings of science content.
Effectiveness of Severe Acute Respiratory Syndrome Coronavirus 2 Monoclonal Antibody Infusions in High-Risk Outpatients

BACKGROUND: Coronavirus disease 2019 (COVID-19) continues to stress the health care system. Neutralizing monoclonal antibodies (mAbs) were effective in reducing COVID-19-related hospitalizations and emergency department (ED) visits in their respective clinical trials. However, these results have yet to be reproduced in a practical setting following implementation of current US Food and Drug Administration (FDA) guidance. METHODS: This retrospective cohort study included outpatients with confirmed COVID-19 infection, who had mild/moderate symptoms for 10 days or less, and who were deemed high-risk for severe COVID-19 under FDA's Emergency Use Authorization for mAbs. Patients who received either bamlanivimab or casirivimab/imdevimab from 18 November 2020 through 5 January 2021 were included (n = 200). This was compared against a control cohort of randomly selected high-risk COVID-19 outpatients who declined or were not referred for mAb treatment during the same period (n = 200). The primary outcome was a composite of 29-day COVID-19-related hospitalizations and/or ED visits. Prespecified secondary outcomes included the individual components of the primary endpoint, 29-day all-cause mortality, and serious adverse drug events. RESULTS: Patients treated with mAbs were significantly less likely to be hospitalized or visit the ED compared with patients not treated with mAb (13.5% vs 40.5%;odds ratio, 0.23 [95% confidence interval, .14-.38];P < .001). The mortality rate was 0% in the mAb group compared with 3.5% in the control group (P = .02). Only 2 patients receiving mAb experienced a serious adverse event requiring treatment. CONCLUSIONS: Among high-risk COVID-19 outpatients with mild/moderate symptoms, early administration of mAbs can potentially reduce the strain on the health care system during the current pandemic.
Perceptions of Racial Gaps, Their Causes, and Ways to Reduce Them

Using new large-scale survey and experimental data, we investigate how respondents perceive racial inequities between Black and white Americans, what they believe causes them, and what interventions, if any, they think should be implemented to reduce them. We intentionally oversample Black respondents, cover many cities in the US, and survey both adults and very young people aged 13 to 17. In the experimental parts, we consider the causal impact of information on racial inequities (such as the evolution of the Black-white earnings gap or the differences in mobility for Black and white children) and explanations for these inequities (i.e., the deep-seated roots and long-lasting consequences of systemic racism) on respondents' views. Although there is heterogeneity in how respondents perceive the magnitude of current racial gaps in economic conditions and opportunities, the biggest discrepancies are in how they explain them. There is a stark partisan gap among white respondents, particularly in the perceived causes of racial inequities and what should be done about them. White Democrats and Black respondents are much more likely to attribute racial inequities to adverse past and present circumstances and want to act on them with race-targeted and general redistribution policies. At the same time, white Republicans are more likely to attribute racial gaps to individual actions. These views are already deeply entrenched in teenagers based on their race and their parents' political affiliation. A policy decomposition shows that the perceived causes of racial inequities correlate most strongly with support for race-targeted or general redistribution policies, a finding confirmed by the experimental results.
Theoretical Analysis of Microwave Breakdown for Microscale Gaps

Plasma limiters and protection shields are vital to protect electronic systems from high power microwave and electromagnetic pulse attacks. While conventional systems protect against such attacks using semiconductor elements, microelectromechanical systems (MEMS), liquid crystals, and ferromagnetic devices for tuning, these devices cannot handle high power. Cold-plasma based devices offer a better solution for protection/limiting needs in the high-power regime given their self-sustainability and reconfigurability.
Effects of intraluminal peptide YY on pancreactic function

Peptide YY (PYY) is released postprandially into both the circulation and the distal intestinal lumen. While circulating PYY inhibits pancreatic secretion and insulin release, the effects of intraluminal PYY on pancreatic function are unknown. The aim of the present study was to evaluate the effect of exogenous, intraileal luminal PYY on pancreatic exocrine function and fasting glucose levels. Chronic pancreatic and ileal fistulae (50 cm from the ileocecal valve) were created in nine mongrel dogs. The animals were given intravenous infusions of secretin (125 ng/kg/h) and cholecystokinin octapeptide (CCK-8, 50 ng/kg/h) for four hours. At the beginning of the second hour, either normal saline or PYY, at low [physiologic (2 ng/ min)] or high [supraphysiologic (50 ng/min)] levels, was infused antegrade into the ileal fistula for two hours. Pancreatic juice was collected for PYY and glucose levels. Ileal luminal PYY infusions had no effect on pancreatic bicarbonate or protein output. Fasting serum PYY and glucose concentrations were unaffected by either dose of intraluminal PYY. We conclude that ileal luminal PYY does not influence pancreatic exocrine function or fasting glucose levels.
Computers in geology---25 years of progress

1. Introduction 2. Weights of evidence modeling and weighted logistic regression for mineral potential mapping 3. Gold prospecting with factorial cokriging in the Limousin, France 4. Recent experiences with Prospector II 5. Correspondence analysis in heavy mineral interpretation 6. Mathematics between source and trap: Uncertainty in hydrocarbon migration modeling 7. Risk analysis of petroleum prospects 8. Characteristic analysis as an oil exploration tool 9. Subsurface stratigraphic analysis 10. Automated correlation based on Markov analysis of vertical successions and Walther's Law 11. Milankovitch cyclicity in the stratigraphic record - A review 12. Can the Ginsburg model generate cycles? 13. Quantitative genetics in paleontology: Evolution in tertiary ostracoda 14. An integrated approach to forward modeling carbonate platform development 15. Principal component analysis of three-way data 16. A solution to the percentage-data problem in petrology 17. Amplitude and phase in map and image enhancement 18. Fractals in geosciences - challenges and concerns 19. An executable notation, with illustrations from elementary crystallography 20. Uncertainty in geology 21. Expert systems in environmental geology 22. From multivariate sampling to thematic maps with an application to marine geochemistry 23. The kinematics of paleo landforms 24. R.G.V. Eigen: Legendary father of mathematical geology Index
Seeds of a computer culture: an archival analysis of programming artifacts from a community technology center

We examined the genre and complexity of computer programs created by members of a community technology center. We collected 240 projects during a six-month period. The program genres reflected animations, games, and graphics in about equal numbers. While the number of computer programs decreased over time, the number of advanced programs remained constant suggesting that members either abandoned programs or paired up with more experienced programmers and continued to develop more complex programs.
Key determinants of repatriated earnings by US multinational enterprises

Purpose – In 2004, as the economy lay in stagnation, Congress searched for ways to stimulate job growth. Many members of Congress believed that high US taxes on repatriated earnings discouraged US-based multinational enterprises (MNEs) from bringing cash (in the form of dividends) home and investing those monies in the USA. As a result, Congress passed, and President Bush signed into law, the 2004 American Jobs Creation Act (AJCA), which reduced tax rates to a maximum 5.25 percent on cash repatriations to the USA over the course of a single tax year, i.e. a “tax holiday”. The purpose of this paper is to explore key determinants of repatriated earnings by US multinational enterprises. Design/methodology/approach – This paper uses data collected from IRS documents between 2004 and 2008 to explore the drivers of MNE repatriations, including the AJCA tax holiday, from various countries to the USA. The paper applies a Lintner equation within a gravity model framework to estimate international liquidity flows. ...
DEVELOPMENT OF A FINITE ELEMENT MODEL OF THE HUMAN NECK

A 3-dimensional finite element model of a human neck was developed to study the mechanics of cervical spine while subjected to impacts. The neck geometry was obtained from MRI scans of a 50th percentile male volunteer. This model consisting of vertebrae C1-T1 was constructed primarily of 8-node brick elements. Vertebrae were modeled using linear elastic-plastic materials and the intervertebral discs were modeled using linear viscoelastic materials. Sliding interfaces were defined to simulate the motion of synovial facet joints. A previously developed head and brain model was also incorporated. Only the passive effects of the head and neck muscles were considered. Data from head drop tests performed at Duke University and data from 3, 24 km/hr cadaver rear-end impact sled tests were used to validate the model. The validated model was integrated into a skeleton torso model previously developed to simulate a 50th percentile male driver in a 48 km/hr impact with a pre-deployed airbag. This simulation was similar to that reported by Cheng et al. In this application, the kinematics and airbag pressure predicted by the model compared with experimental data. None of the airbags used in the simulations or experiments represent any currently in production. Further research is still needed to fully validate the model before it can be used to study neck loads during head-airbag or other serious injury interactions.
International Service Learning Design Projects: Educating Tomorrow's Engineers, Serving the Global Community, and Helping to Meet ABET Criterion

International service-learning projects are an effective educational tool for universities striving to meet the ABET engineering criterion, while also providing transformational experiences to their students and a service to needy populations in the world. This paper discusses the benefits of international service-learning projects for students, the international community, and the university. The year-long process of development and piloting of the first international humanitarian engineering service-learning project within the Department of Civil Engineering at the University of Pittsburgh is presented. Also, the ABET engineering criterion are then discussed, with specific attention to the criterion that are harder to address with traditional engineering education. This pilot project was a collaboration between the senior design course, a local chapter of Engineers Without Borders, and various domestic and international entities. The benefits of international service learning projects are discussed, in the hopes of catalyzing development of similar projects in the future.
Uncertainty and sensitivity analysis of a dry containment test problem for the MAEROS aerosol model

The MAEROS aerosol model is being incorporated into the MELCOR code system for the calculation of risk from severe reactor accidents. To gain insight to assist in this incorporation, a computational test problem involving a five-component aerosol in the containment of a pressurized water reactor was analyzed with MAEROS. The following topics were investigated: (1) the CRAY-1 CPU time requirements to implement and solve the system of differential equations on which MAEROS is based, (2) the effects on computational time and representational accuracy due to the use of different overall section boundaries and numbers of sections and components, and (3) the behavior of the aerosol and the variables which influence this behavior. Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling and regression analysis were used in the investigation. Ten sections and overall section boundaries from 0.1E-6 m to 50.E-6 m were found to be adequate for the problem under consideration. Further, solution time was generally found to be a thousand times or more faster than real time, which is felt to be adequate for MELCOR. Stepwise regression, standardized regression coefficients and partial correlation coefficients were used to investigate the sources of variation in computational time and suspended aerosolmore » concentration. 18 refs., 27 figs., 11 tabs.« less
Seismic Design Criteria for Pipelines and Facilities

This paper contains a description of the current state-of-the-art of seismic design criteria and design procedures for pipelines, and associated facilities and structures. The criteria pertain to both aboveground and belowground pipelines and includes consideration of such factors as the earthquake hazard, design seismic motions and response spectra, and geotechnical factors affecting design.
The cornerstones of medical informatics.

The changes in the health care system over the next decade are goint to make the last 20 years seem like good old days of relative stability. We will continue to see new drugs, new devices, and new techniques; however, the true megachanges of the next decade will center on gathering, managing, and using clinical information. This prediction will prove true for all the health care areas—administrative, clinical, teaching, and research. In health care today, we see pressures for improved access, demands for greater …
SU‐F‐303‐09: Identifying Abdominal Inter‐Organ Motion Correlations Using 4D‐MRI and 4D‐Image Registration

Purpose: This study aims to identify motion correlations between multiple abdominal organs using high spatial resolution 4D-MRI images and 4D-image registration, and to model internal organ motion using known surface motions for individual patients. Methods: 4D-MRI images were acquired at 3T using a spoiled gradient echo sequence with self-gated 3D projection reconstruction. Six healthy human subjects and a MRI motion phantom were scanned with the 4D-MRI imaging sequence. The images were reconstructed into 10 phases with isotropic spatial resolution [1.56 mm]^3. The 4D images were registered with an in-house 4D registration algorithm which uses the self-gating respiratory signals as the temporal regularization energy. A 4D deformation field was generated from the registration. In the human study, we examined motion of three regions of interest (ROIs), including abdominal skin, upper liver, and pancreas head. Each ROI contains 8,000–20,000 voxels. The primary motion trajectory was extracted by principle components analysis. The correlation of inter-organ motion was modeled by 3D orientation matching between motion trajectories. Liver and pancreas motions were projected onto the motion plane of abdominal surface resulting in rotation and scaling parameters. The correlation of inter-organ motions was evaluated using RMS errors of trajectory matching. Results: The accuracy of 4D-registration for the phantom data had RMS error 0.5±0.3mm. The human data registration accuracy, using manual tracking of landmarks, had RMS error 0.9±0.7mm. The motion ranges were 23±16mm (upper liver), 9.5±5mm (pancreas), and 10.2±6mm (surface). Compared to the surface motion, trajectories of liver and pancreas had 85±34 and 63±41 degree angle-of-motion and scale factors 2.4±1.3 and 1.5±1.1, respectively. The trajectory matching errors were 1.0±0.6mm (liver) and 0.7±0.5mm (pancreas). Conclusion: Abdominal inter-organ motion can be accurately characterized using 4D-MRI images and 4D-image registration techniques. The proposed method provides a feasible approach to more accurately use patient surface surrogates to estimate internal organ motions.
Time until incident dementia among Medicare beneficiaries using centrally acting or non-centrally acting ACE inhibitors

Background Centrally active (CA) angiotensin-converting enzyme inhibitors (ACEIs) are able to cross the blood–brain barrier. Small observational studies and mouse models suggest that use of CA versus non-CA ACEIs is associated with a reduced incidence of Alzheimer's disease and related dementias (ADRD). Objective The aim of this research was to assess the effect of CA versus non-CA ACEI use on incident ADRD. Design This is a retrospective cohort study with a non-equivalent control group. Setting and patients This study used a national random sample of Medicare beneficiaries enrolled in Part D with an ACEI prescription. A prevalent ACEI user cohort included beneficiaries (n = 107 179) with an ACEI prescription prior to 30 April 2007; beneficiaries without an ACEI prescription before this date were defined as incident ACEI users (n = 9840). Measurements The main outcome was time until first diagnosis of ADRD in Medicare claims. Results The unadjusted, propensity-matched and instrumental variable analyses of both the prevalent and incident ACEI user cohorts consistently showed similar time until incident ADRD in those taking CA ACEIs compared with those who took non-CA ACEIs. Limitations The limitations of this study include the use of observational data, relatively short follow-up time and claims-based measure of cognitive decline. Conclusions In this analysis of Medicare beneficiaries who were prevalent or incident users of ACEIs in 2007–2009, the use of CA ACEIs was unrelated to cognitive decline within 3 years of index prescription. Continued follow-up of these patients and more sensitive measures of cognitive decline are necessary to determine whether a cognitive benefit of CA ACEIs is realized in the long term. Copyright © 2013 John Wiley & Sons, Ltd.
Shear stress enhances the proteolysis of von Willebrand factor in normal plasma

While von Willebrand factor (vWF) is secreted from endothelial cells as a very large polymer, it circulates as a series of multimers that are reducible to a 225-kD polypeptide and three proteolytic fragments of 189, 176, and 140 kD. Cleavage at the Tyr-842/Met-843 bond of the vWF polypeptide creates the 140- and 176-kD fragments. In the process of understanding vWF multimer formation, the role of shear stress in vWF proteolysis was investigated in this study. A shear-rate-dependent loss of the largest multimers was observed when normal plasma was perfused through long capillary tubings achieving shear rates normally encountered in the circulation. The shear-dependent vWF change was not observed when purified vWF or normal plasma containing calcium chelator EGTA or EDTA was perfused. As the large multimers decreased, an increase in the smaller multimers, including 200- and 350-kD bands, was detected. Elution and immunoblotting studies with peptide-specific antibodies LJ-7745 and VP-1 showed that the 200-kD band was a dimer of the 140-kD fragment, whereas the 350-kD band was a dimer of the 176-kD fragment. When analyzed after disulfide bonds were reduced, sheared plasma showed an increase in the 176- and 140-kD fragments, but not the 189-kD fragment. Finally, shearing of purified vWF enhanced its proteolytic cleavage when it was subsequently incubated with the cryosupernatant fraction of normal plasma or with cathepsin G, a leukocyte granule serine protease. These results show that shear stress is capable of enhancing the susceptibility of vWF to proteolytic cleavage. It promotes vWF proteolysis in normal plasma at a site that generates the 140-kD/176-kD fragments, leading to a decrease in multimer size. Shear stress might be involved in modulating the size of vWF in the circulation.
Mapping organic coatings on atmospheric particles

[1] To date there is no direct evidence of the distribution or characteristics of organic compounds in individual particles because techniques for chemically identifying organic compounds are not sufficiently sensitive to detect molecules or functional groups with masses below 10−15 g [Husar and Shu, 1975]. Here we present detailed maps of organic groups (aromatic, alkyl, ketonic carbonyl and carboxylic carbonyl groups) and inorganic ions (potassium, carbonate, calcium) in individual dry particles with diameters ranging from 0.2 to 10 μm using a new technique for aerosol characterization by soft X-ray spectromicroscopy at atmospheric pressure. The maps show both the compounds present in individual particles and regions of different compositions within particles. The particle compositions on surfaces are enhanced in shorter chain or more oxygenated groups, providing the first observations of surface active carboxylic acids in organic coatings in atmospheric particles.
Nicotinic Receptor Subunit α5 Modifies Assembly, Up-regulation, and Response to Pro-inflammatory Cytokines

In the mammalian brain high affinity nicotine-binding sites are composed of at least the α4 and β2 subunits. Additional nicotinic acetylcholine receptor subunits that are often co-expressed with α4+β2 include α5. The introduction of α5 into 293 cells expressing α4+β2 strongly favors assembly of α4+α5+β2 receptors, increases constitutive ligand binding density as measured using [3H]epibatidine, but reduces the magnitude of up-regulation in response to chronic nicotine. In contrast, when β4 is substituted for β2, α5 interferes with the assembly of these receptors, demonstrating an important role for the β subunit in this process. When cells co-express α4+α5+β2+β4, over 50% of the subunit associations include all four subunits, but they fail to be detected using [3H]epibatidine binding. However, complexes of α4+α5+β2 do preferentially emerge from these subunit mixtures, and these mixtures bind ligand. In previous studies of α4+β2+β4 co-expression by 293 cells, the inflammatory cytokines IL-1β and TNFα influenced the outcome of receptor assembly (Gahring, L. C., Days, E. L., Kaasch, T., Gonzalez de Mendoza, M., Owen, L., Persiyanov, K., and Rogers, S. W. (2005) J. Neuroimmunol. 166, 88–101). When α5 is included in this subunit mixture, and cells are exposed to either inflammatory cytokine, subunit association is no longer altered. These findings suggest that α5 is an influential modulator of α4+β2 nicotinic acetylcholine receptor assembly and stabilizes their expression in response to fluctuations in external conditions.
Health Literacy and the Digital Divide Among Older Americans

Background Among the requirements for meaningful use of electronic medical records (EMRs) is that patients must be able to interact online with information from their records. However, many older Americans may be unprepared to do this, particularly those with low levels of health literacy.
Nanomedical Applications of Optofluidics

In this talk I will discuss some of the nanomedical applications of optofluidic systems. As will be demonstrated such devices hold significant promise for improving on the state of the art in detection sensitivity as well as enable entirely new modalities for molecular analysis. Two example platforms will be discussed. The first of these will be our Nanoscale Optofluidic Sensor Arrays which comprise of a series of 1D evanescently coupled linear optical resonators. In addition to demonstrating both nucleic acid (Dengue virus) and immunological detection (Interleukins), I will show how optical forces can be used to increase the functionality of these devices including single molecule analysis. The second platform described is a method for performing surface enhanced raman spectroscopy (SERS) on a chip. A unique ligase detection reaction based assay will be demonstrated to show the unique advantages of the approach.Copyright © 2010 by ASME
BioBrick Promoter Measurement Kit Instruction Sheets

Instructions for inserting a test promoter into the measurement kit plasmid for characterization as well as instructions for measuring the activity of the test promoter in Standard Promoter Units (SPUs). These instructions were distributed to the teams participating in the International Genetically Engineered Machines competition (iGEM).
A Dynamic Secure QoS Routing Protocol for Wireless Ad Hoc Networks

Due to its high flexibility, mobility and low cost features, wireless ad hoc network has been widely used in various applications. Security and quality of service (QoS) requirements are usually separately considered in such networks. Most of the existing routing protocols provide either secure or QoS routing mechanisms. Few protocols have combined these two requirements together. In this paper, we combine the security and QoS requirements together and develop a dynamic secure QoS routing protocol (DSQ), which simultaneously provides different levels of security and QoS service in the same network. The simulation results have demonstrated the effectiveness of the proposed protocol.
The Third Revolution, Politics, and the Prospect for an Open Society

This paper first attempts to characterize information technology as a political resource. How and in what respect, for example, does information technology compare in nature and significance to energy and other industrial capacities? What are the key differences, from the standpoint of politics? The paper then goes on to identify and assess a few particular impacts this technology is having and is likely to have on the future of American politics and government. Problems dealt with include: the problem of a new class division between those who know how and those who know; the problem of new forms of participation and their effect on the old; the problems of privacy and secrecy; and the future role of education.
Advancing Organizational Support Theory into the Twenty-First Century World of Work

Purpose This review focuses and aids the development of organizational support theory, which explains relationships between employers and employees based on social exchange. Many studies have explored the theory’s central construct, perceived organizational support (POS), or the degree to which employees believe their work organization values their contributions and cares about their well-being. Since the last review of POS literature in 2000, the occupational landscape has shifted, increasing nontraditional work relationships and the importance of managing an international workforce while considering influences on employee well-being. This review discusses how the recent POS research reflects these trends.
Design considerations for multidimensional scaling

This paper begins with a short tutorial on multidimensional scaling. The focus of the remainder of the paper is on the proper designing of research that will use multidimensional scaling analysis techniques and includes suggestions for the interpretation of results.
Single-shot proteomics using capillary zone electrophoresis-electrospray ionization-tandem mass spectrometry with production of more than 1250 Escherichia coli peptide identifications in a 50 min separation.

Capillary zone electrophoresis (CZE)–electrospray ionization-tandem mass spectrometry (ESI-MS/MS) was optimized and applied for analysis of 1–100 ng Escherichia coli protein digests in a single run (single-shot analysis). The system employed an electrokinetically pumped nanospray interface, a coated capillary, and stacking conditions for sample injection. More than 1 250 peptides were identified by optimized single-shot CZE–ESI-MS/MS with 100 ng digest loaded and 50 min analysis time. When 10 ng and 1 ng digests were loaded, about 1 000 and 600 peptides were identified in a single-shot analysis, respectively. Compared with single-shot ultraperformance liquid chromatography (UPLC)–ESI-MS/MS, CZE–ESI-MS/MS produced fewer peptide IDs (1 377 ± 128 vs 1 875 ± 32) for large sample loading amounts (100 ng) with the same mass spectrometer time (50 min). However, when the loaded digest was mass limited (1 ng), CZE–ESI-MS/MS generated many more peptide identifications than UPLC–ESI-MS/MS (627 ± 38 vs 342 ± 113). In...
Self-consistent theory of cyclotron autoresonance maser in a uniform planar waveguide

A general dispersion relation for the cyclotron autoresonance maser (CARM) that takes into account self-consistent couplings between TE, TM and ac space charge perturbations in a uniform planar waveguide is derived. The dispersion relation predicts enhanced growth rate due to ac space charge effects. Results from computer simulations of a planar CARM amplifier are presented to support this finding.
The possible role of assignment catalysts in the origin of the genetic code

A model is presented for the emergence of a primitive genetic code through the selection of a family of proteins capable of executing the code and catalyzing their own formation from polynucleotide templates. These proteins are assignment catalysts capable of modulating the rate of incorporation of different amino acids at the position of different codons. The starting point of the model is a polynucleotide based polypeptide construction process which maintains colinearity between template and product, but may not maintain a coded relationship between amino acids and codons. Among the primitive proteins made are assumed to be assignment catalysts characterized by structural and functional parameters which are used to formulate the production kinetics of these catalysts from available templates. Application of the model to the simple case of two letter codon and amino acid alphabets has been analyzed in detail. As the structural, functional, and kinetic parameters are varied, the dynamics undergoes many bifurcations, allowing an initially ambiguous system of catalysts to evolve to a coded, self-reproductive system. The proposed selective pressure of this evolution is the efficiency of utilization of monomers and energy. The model also simulates the qualitative features of suppression, in which a deleterious mutation is partly corrected by the introduction of translational error.
Nickel cluster structure determined from the adsorption of molecular nitrogen Ni 49 -Ni 71

The geometrical structures of nickel clusters in the size range from 49 to 71 atoms are studied by the chemical probe method. Saturation coverages of molecular nitrogen are determined for each cluster and from this data specific structures are proposed (except for Ni66 and Ni67). The results indicate that icosahedral packing is the dominant structural configuration throughout this size range, in agreement with earlier results based on water and ammonia adsorption. In addition, it seems that for clusters larger than Ni54 the excessive strain in the surface of the 55-atom regular icosahedron often leads to rear-rangements of the surface atoms to relieve that strain. Ni55, in particular, is found to have two isomers, the regular icosahedron and a structure in which a single apex atom is displaced to the center of an opposite face. Ni71 occurs as a 55-atom regular icosahedron with a 16-atom cap. The results suggest that the atoms in the cap adopt an ABA configuration relative to the underlying icosahedron rather than an icosahedral arrangement. For some clusters the saturation with nitrogen causes a small degree of surface reconstruction that leads to the adsorption of additional nitrogen molecules.
Using transient tracers: the regularization problem

The generic problem of deducing fluid properties, velocity, mixing, and boundary conditionsfrom realistic tracer observations is formulated and attacked. The focus is on oceanic transienttracers, but the same problem elements appear in many other fields including meteorology,medicine and chemical engineering. It becomes clear that use of tracers, transient orotherwise, requires at some stage the solution of the advection/diffusion equation eitherupstream, or backwards in time, or both, a situation notorious for its instability becausediffusive processes progressively destroy information in the “forward” direction. We consideran example in simple finite difference form for one space dimension and time. The problem isrun “backwards”, but regularized by solving it through linear programming. Linear programmingis shown also to have several potential advantages for stable and unstable forwardproblems, and the inverse problem: knowledge of the form of the answer is easily used; datauncertainty is accommodated; the positivity constraints on concentrations are implicit; sparsesystem software is available; questions of best observational strategy are addressed by the dualsolution ; and the strong instabilities of the inverse and backwards problems are suppressed. DOI: 10.1111/j.1600-0889.1987.tb00207.x
A corresponding-states correlation of spin relaxation in normal alkanes

Abstract Proton spin-lattice T 1 and spin-spin T 2 relaxation times of the n-alkanes from n-pentane to n-hexadecane were measured at 298.15 K. The T 1 measurements essentially agreed with those of Kashaev et al. [1]. No spin-spin relaxation times of the pure alkanes were found in the literature to compare with our data. The temperature dependence of the relaxation rates of these alkanes follow the ratio of the viscosity divided by the temperature. The spin relaxation rate is dedimensionalized using corresponding-states parameters derived from a hindered-rotational model. The resulting three-parameter corresponding-states relationship is found to be closely obeyed by these alkanes.
A low cost pulse shape digitizer for a time projection chamber

Abstract A high speed (24 MHz) pulse shape digitizer with CAMAC interface, suitable to use in a time projection chamber is discussed. Standard TTL logic and simple design is employed to reduce cost yet with a 16K memory and on-line DAC, the circuit is versatile enough to be used in many applications involving the digitization of transient signals.
Carbon‐13 NMR studies on some 5‐substituted quinoxalines

Eleven 5-substituted quinoxalines (NO2, NH2, COOH, OCH3, CH3, OH, F, Cl, Br, I, CN, the latter five not reported previously) have been synthesized by standard methods. Their 13C NMR spectra have been measured in DMSO-d6 and assigned on the basis of substituent parameters, by line widths and by intensities. The chemical shifts compare favorably with those calculated using benzene substituent parameters, and are very close to those of corresponding carbons in 1-substituted phenazines. The correlation with the chemical shifts of the corresponding positions in 1-substituted naphthalenes is also close except for those of carbons 4a and 8a in the quinoxalines which, due to their proximity to nitrogen, are downfield (in some cases 12 ppm) of the signals of the corresponding carbons in naphthalene. 5-Fluoroquinoxaline was also measured in CDCl3, CD3COCD3, CD3CN, CD3OD, C6D6 and CD3COOD. In all solvents an abnormally low 2J(CF) (∼ 12 Hz) was found for C-4a and no CF spin-spin splitting could be detected for the three-bond coupling of C-8a. Similar abnormalities were found in 2-fluoroaniline and 2-fluoroacetanilide. There are linear relationships between the Q parameter of the substituent and the chemical shift of carbons 4a, 5 and 6. A linear relationship also exists between the chemical shift of C-8 (‘para’ position) and the Hammett σp parameter of the substituent.
Instructional strategies and pedagogy for culturally diverse classrooms

Although previous research and U.S. demographics have established a need for holistic, culturally diverse content and methods, college courses still seem to prefer teaching content over methods, which emphasize holistic learning. This paper presents a framework for incorporating holistic, culturally diverse instructional strategies and pedagogy into communication courses and programs. Several studies that investigated various aspects of the framework, as well as a recent content analysis of 260 courses from across the United States (Milhouse, in press), are discussed. Implications of content and methods for seven programs are presented, as well as two matrices, that comprise a collection of approaches, techniques, and resources.
Lattice Deformations in Alkali-Halide Solid Solutions

Using the Born-Mayer model, calculations on dilute solid solutions of alkali halides have been made. The systems considered are NaCl-NaBr and KBr-NaBr. In this paper ion displacements in the vicinity of an impurity atom are calculated and the results applied to the calculation of heats of solution and lattice constant changes. Electronic and ionic polarization and van der Waals interactions are included and found to be important.
Recovery of infectious SV5 from cloned DNA and expression of a foreign gene

A complete cDNA clone of the genome (15,246 nucleotides) of the paramyxovirus SV5 was constructed from cDNAs such that an anti-genome RNA could be transcribed by T7 RNA polymerase and the correct 3' end generated by cleavage using hepatitis delta virus ribozyme. The plasmid encoding the antigenome sequence was transfected into cells previously infected with recombinant vaccinia virus that expressed T7 RNA polymerase, together with helper plasmids that expressed the viral replication proteins, NP, P, and L, under the control of the T7 polymerase promoter. Rescue of the RNA genome from DNA was demonstrated by recovering SV5 with the tag restriction sites introduced into the DNA clone, using RT-PCR of the genome RNA and nucleotide sequencing. Rescue of SV5 from DNA did not require expression of the viral V protein as a helper plasmid, suggesting that V protein is not essential for initial replication. The infectious cDNA of SV5 was also manipulated to express green fluorescent protein (GFP) under the control of SV5 transcriptional start and stop signals introduced between the HN and L genes. The amount of GFP that was expressed varied depending on the nature of the newly introduced transcription signals.
Spurious Cycles in Water Resources Systems

This paper reviews analytical procedures for deducing from annual streamflow data information required for water resources systems planning. The procedure relies on two techniques to determine the extent that cycles exist in annual time series data. The first is to observe how the time series behaves around the mean annual flow. If it tends not to move across the mean frequently, it is concluded that a cyclical nature exists. The second technique is to observe the time path of accumulated departures from the mean annual flow. The validity of both techniques is questioned. The first because it uses mean flow as “normal” or the flow that the time series should fluctuate around. The second because the accumulated departure from the mean time series will be autocor-related even when the individual annual or seasonal flow observations are uncorrected. Alternative analytical techniques, which find no cycles, are presented.
Dynamics and mechanism of repair of ultraviolet-induced (6–4) photoproduct by photolyase

One of the detrimental effects of UV radiation on DNA is the formation of the (6-4) photoproduct (6-4PP) between two adjacent pyrimidines1. This lesion interferes with replication and transcription and may result in mutation and cell death2. In many organisms a flavoenzyme called photolyase uses blue light energy to repair the 6-4PP3. The molecular mechanism of the repair reaction is poorly understood. Here, we use ultrafast spectroscopy to show that the key step in the repair photocycle is a cyclic proton transfer between the enzyme and the substrate. By femtosecond synchronization of the enzymatic dynamics with the repair function, we followed the function evolution and observed direct electron transfer from the excited flavin cofactor to the 6-4PP in 225 ps but surprisingly fast back electron transfer in 50 ps without repair. Strikingly, we found that the catalytic proton transfer between a histidine residue in the active site and the 6-4PP, induced by the initial photoinduced electron transfer from the excited flavin cofactor to 6-4PP, occurs in 425 ps and leads to 6-4PP repair in tens of nanoseconds. These key dynamics define the repair photocycle and explain the underlying molecular mechanism of the enzyme’s modest efficiency.
The Missing Men: High Risk of Disease in Men of Mexican Origin:

The present study sought to determine gender- and age-specific prevalences of chronic diseases in an urban Mexican American border community. The Cameron County Hispanic Cohort (CCHC; n = 2,000) was selected using a multistaged cluster design. Sociodemographics, anthropometric measures, and blood samples were collected on each participant. More women were obese (55.1%) than men (44.8%). Men had significantly higher rates of diabetes (20.4% for men vs. 15.8% for women, p < .05) and undiagnosed diabetes (6.2% for men vs. 2.4% for women, p < .01); the prevalence of diabetes rose steeply between the ages of 40 and 49 years. Men were significantly more likely to have serum cholesterol levels of 200 mg/dL and elevated low-density lipoprotein levels (22.6% vs. 26.1%, p < .01). Mexican American males in the U.S./Mexico border region have a high prevalence of obesity in younger men and higher overall rates of diabetes, including undiagnosed diabetes, and significantly higher serum cholesterol levels than women.
The microstructure of ordered (Co0.78Fe0.22)3V alloy

Abstract The (Co0.78Fe0.22)3V alloy belongs to a class of long-range-ordered alloys that are being developed for elevated-temperature applications. The microstructure after quenching and after, subsequent aging at temperatures between 973 and 1073 K has been characterized by analytical electron microscopy. Short-range order (SRO) and small VC matrix precipitate particles were observed in the as-quenched material. At 973 K VC precipitated discontinuously along grain boundaries and on extrinsic stacking faults. Aging at 1073 K precipitated VC along grain boundaries and on extrinsic stacking faults, and produced intrinsic stacking faults that were precipitate-free. Ordered domains grew during aging at rates proportional to t 1 2 ; the activation energy for growth was 222 ± 20 kJ/mol. Thermal antiphase boundaries (APBs) had isotropic energies and ( a 2 )〈110〉 displacement vectors. Intrinsic and extrinsic stacking faults also serve as APBs, with displacement vectors of ( a 6 )〈112〉 and ( a 3 )〈111〉 . respectively. Intrinsic faults had relatively high APB energies and interacted strongly with thermal APBs, while the reverse was true for extrinsic faults. Extrinsic stacking faults nucleated at VC particles in the matrix by punching out ( a 2 )[011] dislocations, which dissociated into Frank and Shockley dislocations. The Frank partial climbed away from the particle, and growth proceeded by the Silcock-Tunstall mechanism of alternate precipitation and climb of the Frank partial. Intrinsic stacking faults also nucleated at VC particles, but the perfect dislocation around the particle dissociated into two Shockley partials: ( a 2 )[ 1 01] → ( a 6 )[ 1 1 2] + ( a 6 )[ 2 11] . Then the intrinsic fault grew by glide of the outer Shockley partial.
The Peace and Justice Movement in the South in the 1980s

The “peace and justice movement” has been an important chapter in the evolving character of overall peace organizing in the last several decades. Combining social justice concerns with antimilitarist sentiment, the peace and justice movement was particularly strong in the American South during the late 1970s and early 1980s. Leaders were found in a variety of community groups, statewide networks and clearinghouses, and religious organizations. This article explores the dimensions of the peace and justice movement and describes the activities of such groups as the Institute for Southern Studies, the Clergy and Laity Concerned, the Southeast Network on Human Needs and Peace, the Southern Organizing Committee for Economic and Social Justice, and the Gulf Coast Tenants Organization.
Targeting of small-cell lung cancer using the anti-GD2 ganglioside monoclonal antibody 3F8: a pilot trial

The present study evaluated the ability of the anti-GD2 ganglioside monoclonal antibody 3F8 to target tumor sites in patients with small-cell lung cancer (SCLC). Of 12 patients entered into the trial, ten received intravenous 3F8 labeled with 2 or 10 mCi iodine-131. The first five patients had recurrent or progressive disease after chemotherapy. Subsequent patients were studied before starting chemotherapy. Radionuclide scans were performed on days 1, 2, and 3 post-infusion and once between day 5 and day 7. Four patients underwent single-photon emission tomography (SPET) imaging. Radionuclide scans demonstrated localization to all known sites of disease, other than small brain metastases in one patient. SPET/CT scan fusion images confirmed precise localization. No significant toxicity was observed. Mean serum half-life was 64.2 h. Analysis of specimens from one patient who died of unrelated causes 6 days post-infusion confirmed the scan results. The present study demonstrates that 3F8 targets SCLC sites in patients. Further studies of anti-GD2 antibodies with higher doses of antibody and radionuclide are warranted to evaluate their role in SCLC.
Modification of a Jarrell-Ash Ultraviolet Monochromator to an Infrared Duochromator

A modification is described of a Jarrell-Ash model 82-000 ultraviolet grating monochromator to an infrared two-channel spectrometer which proved to be useful for simultaneous observation of two wavelength intervals by fast response In–Sb detectors in shock tube experiments. The principal concept for the conversion was to use a shorter focal length for the focusing mirror together with a 150-grooves/mm grating resulting in a linear dispersion of 23.1 mm/μ at 4.5 μ. The optical components added for the modification (commercially available flat, spherical, and ellipsoidal mirrors) are inserted as a separate unit into the instrument, so that it can be used also in its original version. A calibration example is given for a particular application requiring simultaneous observation of two spectral intervals centered at 4.25 μ and 5.07 μ, respectively.
Triggers, acute risk factors and vulnerable plaques: the lexicon of a new frontier

A neglected area of cardiovascular research--study of the mechanisms of acute disease onset-is receiving increased attention. The new interest is based on the undisputed findings that onset of myocardial infarction and sudden cardiac death are more likely soon after awakening, indicating that activities of the patient frequently trigger the diseases. Triggering may occur when stressors produce hemodynamic, vasoconstrictive and prothrombotic forces--acute risk factors--that, in the presence of a vulnerable atherosclerotic plaque, cause plaque disruption and thrombosis. Triggering research may clarify mechanisms and suggest measures to sever the linkage between a potential trigger and its pathologic consequence.