cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynamic Response Comparison of Dual-Wound and Single-Wound Machines in Multi-Bus Power System Architectures

Power systems with highly flexible architectures (i.e. permitting many configurations) may allow for more economic operation as well as improved reliability and resiliency. The greater number of configurations enable optimization for attaining the former benefit and redundancy for achieving the latter. Flexibility is of great importance in electric ship power systems wherein the system must ensure delivery of power to vital loads. The United States (US) Navy is currently investigating new architectures that enable a greater number of interconnection permutations. Among the new features considered are generators that may supply two buses; this may be done using conventional (single winding set) generators and two rectifiers or a dual wound machine with two rectifiers. In systems supplied by dual-wound machines, buses may not be tied directly but are linked dynamically through the shared generator dynamics. In systems with conventional generation supplying two rectifiers, the two buses are tied through a common AC bus supplying both rectifiers. This paper presents a comparison of these two approaches of supplying two buses from one generator; the evaluation considers issues associated with dynamic coupling through these two candidate architectures, including the coupled response due to faults and systems with pulsed loads. Results are based on analysis, simulation results, and hardware experiment.
Loss circulation prevention in geothermal drilling by shape memory polymer

Abstract Geothermal formations are naturally fractured with large fracture openings and networks. This can often lead to frequent drilling fluid loss events which is a major contributor to the cost and non-productive time in geothermal drilling. Development of smarter technologies and methods to tackle problem lost circulation is vital for geothermal drilling cost reduction required for geothermal energy to be recognized as a competitive alternative energy source. Mitigation of this problem and other drilling problems such as stuck pipe can minimize overall project cost. In this paper, a thermoset shape memory polymer that can be activated by formation natural heat was assessed to seal near wellbore fractures in geothermal wells. The performance of the shape memory polymer (SMP) was evaluated using artificial fractures created in aluminum discs and cylindrical granite cores. Rheology and particle size distribution were considered. A novel testing setup was built for this work, which allows testing of sealing efficiency under dynamic conditions at high temperature. Analysis showed that the SMP has efficiently succeeded in forming a strong plug inside the fractures and stopped fluid loss at high sealing pressure. This smart loss circulation material can expand within the fractures to reduces non-drilling time and strengthen the wellbore in high-temperature drilling operations.
In gun we trust? A homily1:

Exegetically and homiletically, I offer the possibility that gun violence in US society represents God’s judgment upon our culture’s love for the gun. Talk of judgment may sound foreboding, but pro...
Considerations for the Young Football Player

Tackle football is a uniquely American sport that carries with it a great risk to the developing musculoskeletal system of the prepubescent and adolescent athlete. During a time of great imbalance between longitudinal growth and muscular development, the physical nature of American football often results in very characteristic fractures to the youth athlete. This chapter will review common pelvic and lower extremity fractures, both of the avulsion and contact type, that befall youth football participants and their subsequent diagnosis, treatment, and potential complications.
Caution in testing phenotypic selection.

Understanding whether genetic drift or natural selection is responsible for the phenotypic difference between two strains is a major goal of evolutionary biology. Building on Orr’s quantitative trait locus (QTL) sign test (1), Fraser developed a clever test of phenotypic selection that requires only a genetic cross between the two strains followed by phenotyping of these strains and their F2 progenies (2). The simplicity of this test makes it applicable to a wide variety of traits of many species. Here we draw attention to two caveats. That we are investigating the role of natural selection in the divergence of a trait between two strains, S1 and … [↵][1]1To whom correspondence may be addressed. Email: jianzhi{at}umich.edu. [1]: #xref-corresp-1-1
Investigation and Reduction of a Low-Frequency EMI Noise of AC/DC Power Adapters with Diode Bridge as Input Rectifier

For AC/DC power adapters with a diode bridge as the input rectifier, when the differential mode EMI filter is placed at DC bus instead of AC line, a low-frequency component can be observed in the measured EMI noise spectrum, and it tends to violate the conducted EMI standard. The mechanism of such a phenomenon is introduced and quantified, the analysis model is built up in the paper. Besides, the methods to reduce the low-frequency noise component are investigated and validated by experiments, such as applying an X-capacitor on AC line or using fast recovery diodes, ultra-fast recovery diodes, and qspeed diodes. Both simulations and experiments verify the analysis.
Critical Conversations in Practice-Based Teacher Education: Fostering Equitable Teaching in a Yearlong Practicum

This study explores the use of critical conversations in a field-based practicum setting to develop dispositions toward, and understandings of, equitable teaching practices. To date, few studies ha...
Inoculation theory and public relations

Abstract Inoculation theory explains how an existing state (an attitude, a belief, a position) can be made more resistant to future influence, in much the same way a medical inoculation can make an existing state (a healthy body) more resistant to future viral influence: through pre-exposure to weakened forms of challenges. The theory has established efficacy as an effective messaging strategy in a number of contexts, including politics and health. Another area that has received attention in inoculation theory scholarship is public relations. A comprehensive review of this work, however, is long overdue. We outline existing work in inoculation theory and public relations, and then show how inoculation theory and public relations research can bring new applications and theoretical development to the public relations areas of (1) issues management; (2) crisis and risk communication; and (3) character assassination.
In silico and in␣vivo analyses reveal key metabolic pathways enabling the fermentative utilization of glycerol in Escherichia coli.

Most microorganisms can metabolize glycerol when external electron acceptors are available (i.e. under respiratory conditions). However, few can do so under fermentative conditions owing to the unique redox constraints imposed by the high degree of reduction of glycerol. Here, we utilize in silico analysis combined with in␣vivo genetic and biochemical approaches to investigate the fermentative metabolism of glycerol in Escherichia coli. We found that E. coli can achieve redox balance at alkaline pH by reducing protons to H2 , complementing the previously reported role of 1,2-propanediol synthesis under acidic conditions. In this new redox balancing mode, H2 evolution is coupled to a respiratory glycerol dissimilation pathway composed of glycerol kinase (GK) and glycerol-3-phosphate (G3P) dehydrogenase (G3PDH). GK activates glycerol to G3P, which is further oxidized by G3PDH to generate reduced quinones that drive hydrogenase-dependent H2 evolution. Despite the importance of the GK-G3PDH route under alkaline conditions, we found that the NADH-generating glycerol dissimilation pathway via glycerol dehydrogenase (GldA) and phosphoenolpyruvate (PEP)-dependent dihydroxyacetone kinase (DHAK) was essential under both alkaline and acidic conditions. We assessed system-wide metabolic impacts of the constraints imposed by the PEP dependency of the GldA-DHAK route. This included the identification of enzymes and pathways that were not previously known to be involved in glycerol metabolisms such as PEP carboxykinase, PEP synthetase, multiple fructose-1,6-bisphosphatases and the fructose phosphate bypass.
Rehabilitation of Wilson Dam Generating Units

The first eight hydroelectric generating units at Wilson Dam were placed in service in 1925. The TVA began a program of rehabilitating and modernizing these units in 1964 to reduce maintenance, increase generating capability and provide remote control operation. The major equipment changes included new turbine runners, new generator stators complete with air housings, and new governors. In spite of unforeseen problems with four of the generator spiders which delayed the construction program and resulted in numerous changes to the construction schedule, the program was satisfactorily completed in 1968. The generating capacity of the units was increased an average of 17%, control was transferred to the central control room and the units have been in service for periods up to two years without significant operational or maintenance problems.
Comments on Constructions of Empirical Formulas

The complexity of theoretical solutions of many mechanical problems leads to a construction of empirical or semiempirical formulas being utilized in practical structural design. This is also the case at estimations of load-carrying capacity of slender plate girder webs subjected to a partial edge loadings. In this field a quite rich activity of researchers or engineers can be noted. Let us remind empirical formulas proposed by Granholm (1960), Ostapenko-Yen-Beedle (1968), Rockey-Elgaaly (1971), Bergfelt (1971), (1973), (1974), (1979), Herzog (1974), Drdacký (1974), (1978), Roberts-Rockey (1978), Roberts (1981), Weimar, Ramm (1987), Spinassas-Raoul-Virlogeux (1990). The formulas are derived using different approaches which are not correct in some cases.
Translating between Formats for Mathematics: Current Approach and an Agenda for Future Developments

This paper describes the current directions followed in the UMA project to interoperate between different formats for mathematics. We highlight the state-of-the-art along with directions for future development of the project.
An Initial Analysis of the Impact of Overlap and Independent Progress for MPI

The ability to offload functionality to a programmable network interface is appealing, both for increasing message passing performance and for reducing the overhead on the host processor(s). Two important features of an MPI implementation are independent progress and the ability to overlap computation with communication. In this paper, we compare the performance of several application benchmarks using an MPI implementation that takes advantage of a programmable NIC to implement MPI semantics with an implementation that does not. Unlike previous such comparisons, we compare identical network hardware using virtually the same software stack. This comparison isolates these two important features of an MPI implementation.
Control of hopping height in legged robots using a neural-mechanical approach

We compare two previous approaches for hopping height control to the new scheme proposed in this paper. This new approach is an example of work in the developing area of neural-mechanical systems and has some very simplified versions of building blocks observed in nature, including a central pattern generator. Explicit formulas for hopping height and conditions for stability were obtained for all three approaches based on approximate Poincare return maps (not included). We also present a novel robot leg design and experimental data which supports our analysis. Our adaptive periodic forcing approach is shown to be comparable or out-perform the other two methods in terms of bandwidth requirement, hopping height, and stability properties.
PARALLEL-PLATE MULTISECTION IONIZATION CHAMBERS FOR HIGH-PERFORMANCE REACTORS

1 1. .Introduction 1 2. Chamber Design and Construction 2 . . 2.1 Sensitive' Volume 2 2.2 Chamber Assembly 3 3. Ionization Chamber Performance 5 3.1 . Boron-Coated Ionization Chambers 5 3.2 Gamma-Compensated Ionization Chambers 7 3.3 Fiss ion Chambers 1 0 3.4 Gamma-Sensitive Ionization Chambers 1 2 . . 4. Conclusions 13 5. Appendix : 13 5.1 Description and Character is t ics of Ionization Chambers Built and Tes ted 13 5.2 Ionization Chamber Drawings and Procedures 13
Understanding Phenomenology: Problems and prospects: phenomenology and its critics

Beyond phenomenology? Over the past four chapters, we have considered the four main figures in the phenomenological tradition. Although, as we have seen, the phenomenological tradition is hardly monolithic, replete as it is with intramural debates and in some cases wholesale changes in orientation (consider the divide between Husserl's and Heidegger's respective conceptions of phenomenology), there is nonetheless among these figures a shared sense of there being a distinctive philosophical discipline worthy of the name “phenomenology”, and so a shared sense that phenomenology is both possible and, indeed, philosophically indispensable. Despite many differences both at the programmatic level and at the level of detail, all four figures – Husserl, Heidegger, Sartre and Merleau-Ponty – agree that phenomenology is not only worth doing, but that it aspires to be the method for philosophy. In presenting the views of these four figures, I have taken something of a “used-car salesman” approach, highlighting the strengths of each position and downplaying the weaknesses, except where outright incompatibilities among the positions prevented my doing so. I have thus served more or less as an advocate for each position, all the while realizing that one could not embrace all four simultaneously. Although one must pick and choose among these positions in phenomenology, there remains the option of opting out of phenomenology altogether, and not just out of personal interest and inclination, but because of more principled philosophical considerations.
Fast detection of generic biological particles in cryo-EM images through efficient Hough transforms

One of the current challenges in the analysis of a very large number of images acquired using cryo-electron microscopy is to investigate fast, accurate approaches for automatic detection of biological particles. Cross-correlation with a reference image based techniques have been developed in the past for this purpose; both computational requirements and accuracy, however, have limited their applicability to only a very small set of particles. The paper describes a new computational framework for fast, automatic particle detection, through the application of edge detection and a sequence of ordered Hough transforms. In particular, it presents how to adapt the generalized Hough transform to efficiently detect approximately rectangular shapes in a cluttered background. Preliminary results using hemocyanin as a model particle are promising.
A temperature-based approach to detect abnormal building energy consumption

Abstract This paper introduces a temperature-based approach – called the Days Exceeding Threshold-Toa (DET-Toa) method to detect persisting small increase or decrease in the normal building energy consumption. This method identifies an abnormal energy consumption fault when the deviation between the measured and simulated consumption is greater than one standard deviation of the residuals in the baseline period and persists for at least 20 days which are consecutive when ordered according to increasing or decreasing outside air temperature. The fault detection capability of the method is evaluated with simulation tests with two on-campus buildings. Ten synthetic control changes were assumed to happen and lasted for one year for each building. In the test, the DET-Toa method showed superior capacity for detecting abnormal building energy consumption compared with the DET-Date method. It successfully detected 19 synthetic control changes in the 20 simulation test cases. The reason for the better performance of the DET-Toa method is discussed and demonstrated in an example case. The smallest faults that could be identified by the DET-Toa method in the two analyzed buildings and their related energy consumption impact statistics are also provided in the paper.
Rayleigh-Gans scattering approximation: surprisingly useful for understanding backscattering from disk-like particles

Recent computations of the backscattering cross section of randomly-oriented disk-like particles (refractive index, 1.20) with small-scale internal structure, using the discrete-dipole approximation (DDA), have been repeated using the Rayleigh-Gans approximation (RGA). As long as the thickness of the disks is approximately 20% of the wavelength (or less), the RGA agrees reasonably well quantitatively with the DDA. The comparisons show that the RGA is sufficiently accurate to be useful as a quantitative tool for exploring the backscattering features of disk-like particles with complex structure. It is used here to develop a zeroth-order correction for the neglect of birefringence on modeling the backscattering of detached coccoliths from E. huxleyi.
A note on reflection positivity

We establish reflection positivity of covariance operators, using properties of Dirichlet or Neumann boundary data.
An inequality linking packing and covering densities of plane convex bodies

For every convex body K in R2, let δ(K) denote the packing density of K, i.e. the density of the tightest packing of congruent copies of K in R2, and let υ(K) denote the covering density of K, i.e. the density of the thinnest covering of R2 with congruent copies of K. It is shown here that 4δ(K)⩾3υ(K) for every convex body K in R2. This inequality is the strongest possible, since if E is an ellipse, then the equality 4δ(E)=3υ(E) holds. Two corollaries are presented, and a summary of known bounds for packing and covering densities is given.
Constrained Extrema of Bilinear Functionals

LetA be an operator on a finite dimensional unitary space. This paper contains results on the set of values taken on by the conjugate bilinear functional (A x, y) asx andy range over all unit vectors with prescribed inner product. By analyzing the same problem for the induced functional on the Grassmannian, results on non-principal subdeterminants are also obtained.
Emulsion stability: Determination from turbidity

A novel technique for studying the stability of emulsions has been developed. Owing to the fact that emulsion turbidity is a function of particle concentration and size, the stability of emulsions can be determined by measuring the change in turbidity with time. The relationship between turbidity and particle size and concentration is derived for a polydispersed emulsion. The stability of acoustically prepared emulsions determined by measuring the initial mean particle size and changes in emulsion turbidity is compared with the stability determined from scanning electron microscope measurements of the particle growth rate. The agreement between the two methods is excellent.
Penile Length in the Flaccid and Erect States: Guidelines for Penile Augmentation

AbstractPurpose: We provide guidelines of penile length and circumference to assist in counseling patients considering penile augmentation.Materials and Methods: We prospectively measured flaccid and erect penile dimensions in 80 physically normal men before and after pharmacological erection.Results: Mean flaccid length was 8.8 cm., stretched length 12.4 cm. and erect length 12.9 cm. Neither patient age nor size of the flaccid penis accurately predicted erectile length. Stretched length most closely correlated with erect length.Conclusions: Only men with a flaccid length of less than 4 cm., or a stretched or erect length of less than 7.5 cm. should be considered candidates for penile lengthening.
Discussion of “Stream Depletion by Groundwater Pumping in Leaky Aquifers” by Vitaly A. Zlotnik and Daniel M. Tartakovsky

The authors’ solution assumes that a pumped leaky aquifer is underlain by a source bed that has zero drawdown for all time. However, an actual source bed always has finite drawdown values after relatively long periods of time, and this means that the authors’ solution is valid only for a relatively short period of time after pumping starts. Since stream depletion solutions are almost always used to predict stream depletion values after long periods of time, this means that the solution obtained by the authors is of very limited use. In particular, steady-flow stream-depletion values predicted after an infinite period of pumping in the authors’ solution will always underestimate the actual stream depletion. Unfortunately, this means that their solution is in danger of being misapplied by anyone who wants to justify excessive well abstractions when applying for water right permits. In closing, it is worth pointing out that the equations solved by the authors are identical with Eqs. 18 – 21 in Hunt 2003 if S and in Hunt are replaced with the pumped aquifer specific yield and infinity, respectively. In other words, an appropriate choice of variables allows the Hunt 2003 solution to reproduce the solution obtained by the authors. It would be a misuse of this solution to do so, however, for the reason given above.
Using computer analyses to identify language style and aggressive intent: The secret life of function words

The ways people use words can reveal a great deal about their personalities, intentions, and social relationships. Rather than focusing on the content of speech, the current approach examines the style of language use through people's use of function words (e.g., pronouns, prepositions, articles). By calculating the degree to which individuals and groups use function words across a wide variety of texts, it is possible to determine when groups are most prone to engage in violence. The current project analyzed 296 speeches, interviews, and articles from members of four extremist Arabic-speaking groups, two of which have a history of violent attacks, using a computerized text analysis program that calculated the percentage of total words that reflected different function word categories. Overall, each group had its own distinctive language style that reflected, in essence, its own personality. In the month preceding and following violent acts, both terrorist groups changed in their language use in ways that...
International Cooperation on Human Lunar Heritage

The U.S. Apollo Space Program was a premier technological accomplishment of the 20th century. Preserving the six historic landing sites of the manned Apollo missions, as well as the mementos and equipment still on the Moon from those and other U.S. (e.g., Ranger and Surveyor) and Soviet Union (e.g., Luna) missions is important. Some of the instruments on the lunar surface are still active, monitored, and provide valuable scientific information. But recent government and private-sector plans to explore and potentially use lunar resources for commercial activity raise questions about the use of the Moon and potential accidental or purposeful threats to the historic sites and scientific equipment there. Although some steps to protect these sites have been proposed, we suggest a better way, drawing on international, not U.S. unilateral, recognition for the sites.
Genetic-based differences in neurotensin levels and receptors in brains of LS × SS mice

Abstract Levels of endogenous neurotensin (NT-IR) in the LS × SS RI strains differed by 3.0-, 4.7-, 5.4-, and 6.9-fold in the ventral midbrain (VMB), hypothalamus (HY), nucleus accumbens (NA), and caudate putamen (CP), respectively. Frequency distributions and estimates of the number of genes indicate that differences in NT-IR are polygenically influenced. The NT-IR levels in NA and CP were significantly correlated, but levels in the VMB did not correlate with those in the NA or CP. Specific binding to either low (NT L )- or high (NT H )-affinity receptors as measured in the absence or presence of levocabastine differed significantly in brain regions from among LS × SS mouse strains. Results indicate a polygenic influence mediating the differences in receptor densities and suggest differences in genetic regulation of NT L and NT H receptors.
Spark plasma sintering and mechanical behavior of magnesia–yttria (50:50 vol.%) nanocomposites

Fully dense magnesia–yttria (50:50 vol.%) nanocomposites with average grain sizes ranging from 125 to 223 nm have been prepared by spark plasma sintering. Grain growth is mainly dominated by grain boundary diffusion. A coarser grained sample prepared by post-sinter annealing was also studied for comparison. Samples with finer grain sizes exhibit superior mechanical properties, including higher microhardness and improved nanoscratch behavior. The fracture toughness, 1.5 MPa m 1/2 on average, is independent of the average grain size of the samples.
The HPV response is different with constant pressure vs constant flow perfusion.

Abstract Hypoxic pulmonary vasoconstriction (HPV) may be manifest in one of two ways: either an increase in the pulmonary artery pressure, or flow diversion away from the portion of the pulmonary bed with reduced conductance. We tested the hypothesis that the magnitude of the HPV response differs under conditions of constant flow perfusion, where pulmonary artery pressure (Ppa) rises during hypoxia, vs conditions of constant perfusion, where Ppa remains constant and flow (Q) is diverted away from the lungs during hypoxia. In isolated, perfused rabbit lungs, the HPV response to four levels of hypoxia (12, 6, 3 and 0% oxygen) was of greater magnitude and more sustained under conditions of constant pressure perfusion as compared to constant flow perfusion. The possible significance of these findings as they relate to interpretation of studies in both the perinatal and mature pulmonary circulation is discussed.
A Deformable Mass Formula and Fission Data

Development within the past decade of improved shell model and deformation corrections to the liquid-drop mass law has not only improved its accuracy but also allowed use in more aspects of nuclear physics, such as calculation of fission barriers. Additional experimental data are thus available as input for determination of mass-formula parameters. Preliminary results including fission barrier heights and fission Q-values as input data will be presented. Statistical tests have been performed on fits to the 1971 mass table and to the input reactions and doublets, indicating a possible discrepancy between the two forms of data.
Complex Protostellar Chemistry

Two decades ago, our understanding of the chemistry in protostars was simple-matter either fell into the central star or was trapped in planetary-scale objects. Some minor chemical changes might occur as the dust and gas fell inward, but such effects were overwhelmed by the much larger scale processes that occurred even in bodies as small as asteroids. The chemistry that did occur in the nebula was relatively easy to model because the fall from the cold molecular cloud into the growing star was a one-way trip down a well-known temperature-pressure gradient; the only free variable was time. However, just over 10 years ago it was suggested that some material could be processed in the inner nebula, flow outward, and become incorporated into comets (1, 2). This outward flow was confirmed when the Stardust mission returned crystalline mineral fragments (3) from Comet Wild 2 that must have been processed close to the Sun before they were incorporated into the comet. In this week's Science Express, Ciesla and Sandford (4) demonstrate that even the outermost regions of the solar nebula can be a chemically active environment. Their finding could have consequences for the rest of the nebula.
Exploiting tumor metabolism: challenges for clinical translation

The metabolism of cancer cells differs from most normal cells, but how to exploit this difference for patient benefit is incompletely understood. Cancer cells require altered metabolism to efficiently incorporate nutrients into biomass and support abnormal proliferation. In addition, the survival of tumor cells outside of a normal tissue context requires adaptation of metabolism to different microenvironments. Some existing chemotherapies target metabolic enzymes, and there is a resurgent interest in developing new cancer drugs that interfere with metabolism. Success with this approach depends on understanding why specific metabolic pathways are important for cancer cells, determining how best to select patients, and developing technologies for monitoring patient response to therapies that target metabolic enzymes. The articles in this Review series address these issues, with a focus on how altered metabolism might influence tumor progression and how this knowledge might inform the use of new therapies targeting cancer metabolism. Emerging biomarker strategies to guide drug development are also highlighted.
Long-Term Brightness Variations of Neptune and the Solar Cycle Modulation of Its Albedo

The visual brightness and albedo of Neptune vary periodically during the 11-year solar cycle with an amplitude of 4%, anticorrelated with the variation of solar ultraviolet output. A seasonal trend in color suggests that Neptune, like Uranus, may have a slightly reddened pole.
Plasmablastic Lymphoma of Head and Neck: Report of Two New Cases and Correlation with c-myc and IgVH Gene Mutation Status

Plasmablastic lymphoma (PBL) is a rare acquired immunodeficiency syndrome-associated non-Hodgkin’s lymphoma (AIDS-NHL), with predilection for the mucosa of oral cavity. It usually has a plasmablastic morphology, expressing plasma cell-associated antigens with weak or absent expression of B-cell-associated markers. To further define the immunophenotypic and molecular genetics of these tumors, we investigated two cases of plasmablastic lymphomas of the head and neck for c-myc gene rearrangement and immunoglobulin heavy chain (IgVH) hypermutation status. For the first time we report a case of AIDS-related PBL that, by fluorescence in situ hybridization (FISH), shows a c-myc gene rearrangement. Although current literature suggests that most cases of c-myc gene rearranged AIDS-NHL are Burkitt’s lymphoma, our case has an immunophenotype characteristic for PBL. In this case, IgVH hypermutation analysis showed a somatic hypermutation, indicative of germinal center transit. The concurrent B-cell immunophenotype of BCL-6−/CD138+/MUM-1+ also suggests a post-germinal center B-cell origin of this lymphoma. The immunophenotype of our second case (BCL-6−/CD138+/MUM-1+) also suggests a post-germinal center B-cell origin. However, IgVH hypermutation analysis was not possible in this case.
Giant sarcoplasmic reticulum vesicles: A study of membrane morphogenesis

Rabbit sarcoplasmic reticulum vesicles were fused into giant proteoliposomes in a medium of 0.1 M KCl, 10mm Tris-maleate, pH 7.0, 10 Μg ml−1 antipain, 10 Μg ml−1 leupeptin, 25 IU per ml Trasylol, 3mm NaN3, 3.75% PEG 1500 and 3% DMSO by brief exposure to 37‡ C, followed by incubation for 4 h at 25‡ C. Approximately 5–10% of the sarcoplasmic reticulum elements underwent fusion, forming single-walled spherical vesicles of 1–25 Μm diameter, in which the polarity of the native membrane was preserved. The Ca2+-stimulated ATPase activity remained essentially unchanged after fusion. On exposure to decavanadate in a Ca2+-free medium the spherical vesicles assumed a corrugated appearance with the formation of long ridges separated by deep furrows that eventually pinched off longitudinally and separated into numerous long crystalline tubules of uniform (approximately 0.1 Μm) diameter. The vanadate-induced transformation of giant vesicles into tubules implies that the geometry of the sarcoplasmic reticulum membrane is determined by the conformation of the Ca2+-ATPase.
Characterization of Fe, Fe-Cu, And Fe-Ag fischer-tropsch catalysts

Abstract Copper and silver were found to interact very differently with the oxidized iron catalyst. Copper is oxidized and highly dispersed on the passivated iron surface. The intimate contact between copper oxide and iron oxide and the facile reduction of copper oxide are responsible for the ability of copper to enhance the reduction of iron oxide. The metallic copper nuclei promote the nucl
Influence of stability and mechanical properties of a spinal fixation device on production of wear debris particles in vivo.

A prospective and quantitative animal study was performed to evaluate the production of wear particles from a spinal fixation device, and to test the hypothesis that the concentration of wear debris particles adjacent to spinal fixation hardware is correlated with the stiffness of the spinal fusion construct and local bone formation at the fusion site. An established canine segmental spinal fusion model with three interfacet fusions was used in this study. Several bone substitute materials were grafted to the area of the interfacet fusion. Internal fixation was performed on both sides of the spinous processes at each site using a stainless steel plate system in 19 dogs. After 12 weeks, spinal segments were excised, then 3-dimensional computerized tomography was used to measure bone volume and bone area of the individual fusion sites. The stiffness of each segment was tested using a servohydraulic materials testing machine. Biopsies were obtained from the soft tissues immediately around the plate system, and wear particles were collected and characterized using an electrical resistance particle analyzer, light and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX). Biopsies from para-spinal tissue from adjacent, unoperated spinal levels served as negative controls. Histologically, 24 of 57 specimens (42.1%) showed only fibrous tissue with no recognizable macrophages, inflammation, or debris. Fourteen of 57 specimens (24.6%), however, contained many particles that were composed of Fe, Cr, and Ni, corresponding to elements found in the fixation hardware. Another 19 specimens showed only occasional particles. The mean concentration of particles from the tissue around the plate system was 2.8 x 10(9) per gram dry tissue weight, compared to 0.5 x 10(9) particles per gram for controls (p < 0.05). Statistical analyses showed significant inverse correlation between the log particle number and stiffness (r = -0.41, p < 0.01), bone volume (r = -0.28, p < 0.05), and bone area (r = -0.34, p < 0. 05) of the corresponding segments. The concentration of particles in the tissue showed a significant inverse correlation with stiffness, bone volume, and bone area of the fusion constructs.
From primary to the presidency: A panel study of images and issues in the 1976 election

A study of two groups of Florida voters, those who voted for Ford in the general election and those who voted for Carter, suggests that as early as February, a month before the Florida primary, the groups differed significantly in their perceptions of the two candidates—although at that time only nine percent of them mentioned Ford or Carter as their preferred candidate. The majority of the respondents in both groups thought of themselves as “Democrats,”; though the Ford group had fewer “Very Strong Democrats.”; The groups’ initial attitudes toward campaign issues that would likely discriminate Ford from Carter voters did not differ significantly.
Concentration-dependent hydrogen exchange kinetics of 3H-labeled S-peptide in ribonuclease S☆

The hydrogen exchange kinetics of the S-peptide in ribonuclease S can be measured by first tritiating the S-peptide in the absence of S-protein and then allowing it to recombine rapidly with S-protein. Afterwards the exchange reactions of this specific segment of ribonuclease S can be studied. The exchange kinetics of bound S-peptide are complex, indicating that different protons exchange at markedly different rates. The terminal exchange reaction, involving at least five highly protected protons, has been studied as a function of pH. At low concentrations of ribonuclease S the exchange kinetics become concentration-dependent, owing to the dissociation of the S-peptide. Although the fraction of free S-peptide is always very small, its rate of exchange is several orders of magnitude faster than that of bound S-peptide, and the concentration dependence of the exchange kinetics is readily measurable. It provides a highly sensitive method for determining small dissociation constants (KD). Values of KD ranging from 10−6m at pH 2.7, 0 °C, to 2 × 10−10m at pH 7.0, 0 °C, are reported here. Our value for KD at pH 7.0, 0 °C, confirms the data and extrapolation to 0 °C of Hearn et al. (1971). At high concentrations of ribonuclease S the terminal exchange reaction is independent of concentration. It probably results from a local unfolding reaction of the bound S-peptide. Above pH 4 the strong pH dependence of KD closely resembles that of the apparent equilibrium constant for this local unfolding reaction. The latter may be one step in the dissociation process and we present such a model for ribonuclease S dissociation. Measurement of concentration-dependent exchange kinetics should provide a useful method of determining small dissociation constants in other systems: for example, in studies of protein-nucleic acid interactions.
Assessment of patient satisfaction utilizing the American Pain Society's quality assurance standards on acute and cancer-related pain

An evaluation of patient satisfaction with pain management is one component of a total quality assurance program on pain management recommended by the American Pain Society. This study utilized the patient satisfaction survey recommended by the Quality Assurance Committee of the American Pain Society and was conducted in an acute care, municipal hospital. Seventy-two medical-surgical patients were interviewed about their pain management. Data from the survey suggest that while patients experienced moderate-to-severe pain and had to wait relatively long periods of time for pain medications, in most cases they were satisfied with their overall pain management. Recommendations for conducting patient satisfaction surveys of pain management in acute care settings are reviewed, and methods for interpreting data from these types of surveys are discussed.
Seismic reflection investigations of a bedrock surface buried under alluvium

Seismic reflection techniques were used to characterize a bedrock surface buried under alluvium near a construction site on the campus of Baylor University in Waco, Texas. One of the objectives of the study was to determine if either compressional or shear seismic profiling could be used to reduce the number of engineering boreholes required to determine the bedrock depth and relief prior to building construction. The upper few meters of the alluvium is dry but the lower portion is below the water table, making the bedrock surface a difficult target for compressional waves. The compressional reflection coefficient at the water table is an order of magnitude greater than that at the bedrock surface, and the dry alluvium reduces the signal bandwidth such that the two reflections cannot be distinguished. Also, the multimode Rayleigh ground roll, traveling along the surface at about half the speed of the compressional wave, swamps the reflections. By using shear waves to profile the alluvium/bedrock interface...
Incorporating natural language descriptions into modeling and simulation

We explore an approach to merging simulation and natural language in which conceptual structures are used which can repre sent the structure and meaning of sentences as well as basic mathematical c...
Lattice conditional independence models for seemingly unrelated regressions

Seemingly unrelated regressions (SUR) models appear frequently in econometrics and in the analyses of repeated measures designs and longitudinal data. It is known that iterative algorithms are generally required to obtain the MLEs of the regression parameters. Under a minimal set of lattice conditional independence (LCI) restrictions imposed on the covariance structure, however, closed-form MLEs can be obtained by standard linear regression techniques (Andersson and Perlman, 1993, 1994, 1998). In this paper, simulation is used to study the efficiency of these LCI model-based estimators. We also propose two possible improvements of the usual two-stage estimators for the regression parameters.
Droplet Size Control In Polymer Dispersed Liquid Crystal Films

We have established correlations between the liquid crystal (LC) droplet size and selected characteristics of polymer dispersed liquid crystal (PDLC) films, formed by photopolymerization of LC dissolved in a monomer. The LC droplet size was controlled by means of the ultraviolet (UV) exposure intenstiy, LC concentration, and concentration of polymerization initiator. Correlations were noted between the LC droplet size and the resulting PDLC threshold and operating voltages for optical transmission, contrast ratio, and electro-optical response times. Good contrast PDLC films were obtained which were operable with less than 20 V, rms of applied signal. Special types of films, including in situ gratings were obtained by varying the conditions of polymerization across the film to produce a periodic spatial variation in the LC droplet size.
Studies of structures and phase transitions of Langmuir monolayers using synchrotron radiation

It has been known for decades that lipid molecules can be spread on the surface of water to form monolayers, and that these monolayers undergo phase transitions as a function of pressure and temperature. However, it is only in the past few years, and only because of the availability of synchrotron radiation, that the structures of a number of Langmuir monolayer phases have been determined. In most cases these results contradict the assumptions commonly made earlier.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A precision six-load-component transducer: A design incorporating finite-length measurement paths

The design of an instrument is described that measures three resultant force components and three resultant moment components acting on a surface. Within the framework of linear elastostatics of an isotropic homogeneous material the device separates to a given precision the six resultant load components. Sensor paths of finite length are employed. Moreover if fiber-optic differential displacement sensors are used rather than traditional electrical resistance strain gages, the range and sensitivity of the instrument can in principle be improved without sacrificing the device stiffness. The primary reason for these improvements is that a complete solution to the equations of elasticity allows certain displacements to be measured over large distances and be combined to yield all of the resultant load components. These displacement measurements over a long distance accommodates the use of fiber-optic interferometric sensors. The use of optical sensors in contrast with electrical-resistance gages, has the potential to allow the measurement precision and range to scale with the geometry of the device rather than the maximum strain in the instrument. It becomes possible by virtue of these features to produce a better instrument.
Characterization of Porous Snow with SEM and Micro CT

Firn is a porous material, which can be thought of as an intermediate stage between ice and snow. It is formed by the slow densification of snow due to temperature gradients and overburden pressure. The resulting microstructure is an interconnected network of tortuous pore space segmented by ice particles. With increasing depth pores become segregated and the material ceases to be firn but is characterized as ice. Firn microstructure is of the utmost importance in polar research due to its role in ice-air interactions, texture formation, and its ability to trap chemical impurities.
Chemistry of (tetramethylcyclopentadienyl)gallium(III) compounds

Abstract Two tetramethylcyclopentadienyl gallium(III) compounds Ga(C 5 Me 4 H) 3 and Cl 2 (C 5 Me 4 H)Ga·pyridine have been prepared and characterized. In contrast, when the syntheses of Ga(C 5 Me 4 H) 2 Cl, Ga(C 5 Me 4 H)Cl 2 and Me 2 Ga(C 5 Me 4 H) were attempted by metathetical and/or ligand redistribution reactions, the isolated product in each case was a mixture of chemically related compounds rather than single species. When pyridine was added to a solution prepared by combining Ga(C 5 Me 4 H) 3 and GaCl 3 in a 1:2 mol ratio in diethyl ether, the product was the adduct Cl 2 (C 5 Me 4 H)Ga·pyridine, a yellow–green crystalline solid. An elemental analysis, 1 H- and 13 C-NMR spectra and an X-ray structural study confirmed the identity of this gallium–nitrogen adduct.
Performance evaluation of a chemical fume extractor for indoor working environment improvement

The purpose of this study is to systematically evaluate the performance of a portable chemical fume extractor used for cleaning chemical fume in small work places. Four chemical liquids, a closed chamber, and a metal-oxide sensor were used to evaluate its performance. The experimental results show that the unit under test is able to extract high concentrations of the tested chemical vapors and the cleaning processes take 5 minutes in average to clean out a strong-smelling fume concentration of 29 ppm. The performance is evaluated in terms of the cleaning efficiency (η) and clean air delivery rate (CADR).
Hepatic phosphorylase and epinephrine hyperglycaemia

Abstract The activities of various hepatic enzymes of hexose metabolism were studied in normal rats. The activities and their standard errors, expressed in micromoles of substrate reacting per minute per gramme wet-weight of liver at 30°, were found to be: glucose-6-phosphatase, 6.5 ( ± 0.34); fructose-1:6-diphosphatase, 5.0 ( ± 0.29); glucose-6-phosphate dehydrogenase, 1.1 ( ± 0.14); 6-phosphogluconic dehydrogenase, 2.6 ( ± 0.44); fructokinase, 4.5 ( ± 0.62); phosphorylase (towards glycogen), 12.3; phosphorylase (towards glucose-1-phosphate), 4.4. The high relative activity of phosphorylase, as well as its reversibility, raised serious questions as to the role of phosphorylase activation in epinephrine-induced hyperglycaemia. Furthermore, no alteration in the activity of this enzyme was detected when hyperglycaemia was prevented by administration of dihydroergotamine, or was produced by injection of epinephrine. These findings suggested that epinephrine administration must bring about, in addition to phosphorylase activation, events which alter the equilibrium conditions to those greatly favouring glucose formation or which activate an alternative pathway for glycogen breakdown.
Concerning the inter-hemispheric transfer of mirror-image patterns in pigeon

Abstract Pigeons were monocularly trained on a chain DRO VI 1 reinforcement schedule, on each of the following discrimination problems: (a) up-down mirror-image patterns; (b) left-right mirror-image patterns; and (c) ambiguous figures containing both up-down and left-right cues. Discrimination performance was equivalent on each type of mirror-image problem with the “trained” eye alone open. Pigeons were then tested for inter-hemispheric transfer of each of twelve discrimination problems. It was found that transfer performance with the “untrained” eye open varied with the predominant orientation of the mirror-image patterns. Performance on the 3 up-down mirror-image problems indicated veridical transfer, i.e., pigeons responded maximally to the positive discriminative stimulus (S +). On five of the seven left-right mirror-image problems, pigeons responded maximally to the negative discriminative stimulus (S −) during tests with the “untrained” eye open. These data indicate the occurrence of inter-hemispheric reversal of the left-right mirror-image patterns. Discrimination performance on the other two left-right mirror-image patterns was at a chance level indicating an absence of inter-hemispheric transfer. The two ambiguous figure pairs also failed to transter and therefore performances fell between the inter-hemispheric reversal of left-right patterns and the veridical transfer of up-down patterns.