cssi/SciSciGPT-SciSciNet huggingface dataset:
Crystal Structure of the Nonerythroid α-Spectrin Tetramerization Site Reveals Differences between Erythroid and Nonerythroid Spectrin Tetramer Formation

We have solved the crystal structure of a segment of nonerythroid α-spectrin (αII) consisting of the first 147 residues to a resolution of 2.3 Å. We find that the structure of this segment is generally similar to a corresponding segment from erythroid α-spectrin (αI) but exhibits unique differences with functional significance. Specific features include the following: (i) an irregular and frayed first helix (Helix C′); (ii) a helical conformation in the junction region connecting Helix C′ with the first structural domain (D1); (iii) a long A1B1 loop in D1; and (iv) specific inter-helix hydrogen bonds/salt bridges that stabilize D1. Our findings suggest that the hydrogen bond networks contribute to structural domain stability, and thus rigidity, in αII, and the lack of such hydrogen bond networks in αI leads to flexibility in αI. We have previously shown the junction region connecting Helix C′ to D1 to be unstructured in αI (Park, S., Caffrey, M. S., Johnson, M. E., and Fung, L. W. (2003) J. Biol. Chem. 278, 21837–21844) and now find it to be helical in αII, an important difference for α-spectrin association with β-spectrin in forming tetramers. Homology modeling and molecular dynamics simulation studies of the structure of the tetramerization site, a triple helical bundle of partial domain helices, show that mutations in α-spectrin will affect Helix C′ structural flexibility and/or the junction region conformation and may alter the equilibrium between spectrin dimers and tetramers in cells. Mutations leading to reduced levels of functional tetramers in cells may potentially lead to abnormal neuronal functions.
Early increase in nuclear acidic protein synthesis after SV40 infection.

WHEN the replication of density-inhibited cultures of fibroblasts1,2 is stimulated by a change of medium3–5, the rate of nuclear acidic protein synthesis10–13 is immediately increased. We wanted to determine whether the induction of cellular DNA synthesis by an oncogenic virus6–9 is also preceded by nuclear acidic protein synthesis. We report here the effect of SV40 virus infection of a permissive and a non-permissive cell line on their synthesis of total cellular proteins and nuclear acidic proteins in the first hours after infection.
Polar encapsidation of adenovirus DNA: evolutionary variants reveal dispensable sequences near the left ends of Ad3 genomes.

Abstract Repeated passage of adenovirus type 3 in HeLa cells has led to a novel stock of variant genomes, characterized by deletions and substitutions of DNA sequences within the left-end 750 base pairs. This heterogeneous stock retains few if any parental genomes—the majority of variants appear viable. Analysis of viable variants with deleted sequences reveals the 182 nucleotides proximal to the left-end inverted terminal repeat (136–318 bp) are not required for Ad3 infectivity in cultured human cell lines nor for maintenance of viral DNA encapsidation polarity.
Antioxidants in Down syndrome

Individuals with Down syndrome (DS) have high levels of oxidative stress throughout the lifespan. Mouse models of DS share some structural and functional abnormalities that parallel findings seen in the human phenotype. Several of the mouse models show evidence of cellular oxidative stress and have provided a platform for antioxidant intervention. Genes that are overexpressed on chromosome 21 are associated with oxidative stress and neuronal apoptosis. The lack of balance in the metabolism of free radicals generated during processes related to oxidative stress may have a direct role in producing the neuropathology of DS including the tendency to Alzheimer disease (AD). Mitochondria are often a target for oxidative stress and are considered to be a trigger for the onset of the AD process in DS. Biomarkers for oxidative stress have been described in DS and in AD in the general population. However, intervention trials using standard antioxidant supplements or diets have failed to produce uniform therapeutic effect. This chapter will examine the biological role of oxidative stress in DS and its relationship to abnormalities in both development and aging within the disorder. This article is part of a Special Issue entitled: Antioxidants and Antioxidant Treatment in Disease.
Rare case of gallbladder cancer presenting with meta- stasis to bone and brain in an African American male discovered by F18-FDG PET/CT

The most common site of metastasis in gallbladder cancer is the liver. To our knowledge, there are no reports in the literature of gallbladder cancer metastasizing to both the brain parenchyma and the bone. There are only 5 prior reports of gallbladder cancer metastasis to the bone in the English Language literature. Likewise, gallbladder neoplasm metastasizing into the brain parenchyma is extremely rare. We present a rare case of gallbladder cancer presenting with metastases to both the brain parenchyma and the bone in a 71 year old African American male. This patient had early bone metastasis evidenced by hypermetabolic lesions on FDG PET/CT imaging, without density abnormalities of the bone tissue. Gastrointestinal (GI) tumors are commonly detected by CT but for metastasis, F18-FDG PET/CT has higher sensitivity and higher positive predictive value than CT. Since at the initial presentation, most patients suffering from gallbladder cancer tend to have metastatic disease, we raise a question as to whether F18-FDG PET/CT scans should be included in the routine work-up protocol.
WNTs in the Neonatal Mouse Uterus: Potential Regulation of Endometrial Gland Development

The WNTs are secreted proteins that control essential developmental processes, such as embryonic patterning, cell growth, migration, and differentiation. In mice, three members of the Wnt gene family (Wnt4, Wnt5a, and Wnt7a) have been studied extensively in the female reproductive tract. The present study determined effects of postnatal day and exposure to diethylstilbestrol (DES) on Wnt and Fzd gene expression in the mouse uterus as well as the biological role of Wnt11 in postnatal mouse uterine development and function. Wnt4, Wnt5a, Wnt7a, Wnt7b, Wnt11, Wnt16, Fzd6, and Fzd10 were detected by in situ hybridization in the neonatal mouse uterus. In situ hybridization analyses revealed that Wnt4, Wnt5a, and Wnt16 were localized in the endometrial stroma, whereas Wnt7a, Wnt7b, Wnt11, Fzd6, and Fzd10 were in the uterine epithelia of neonatal mice. Exposure of mice to estrogen or estrogen receptor agonists during critical development periods inhibits endometrial adenogenesis. In the present study, DES-induced disruption of endometrial gland development was associated with reduction or suppression of Wnt4, Wnt5a, Wnt7a, Wnt11, Wnt16, and Fzd10. Ablation of Wnt11, an epithelial-expressed, DES-regulated gene, in the neonatal uterus did not affect endometrial adenogenesis or expression of other Wnt genes. Interestingly, Wnt11-deleted uteri had more endometrial glands on Postnatal Day 10. Although CTNNB1 expression was not affected by ablation of Wnt11, Vangl2 was inhibited in the uteri of Wnt11d/d mice. These results support the idea that a number of different Wnt genes are potential regulators for uterine morphogenesis; however, Wnt11 does not have a direct effect on uterine development.
Some biochemical studies on the erythrocyte of the domestic goat, Capra hircus

Abstract The erythrocyte metabolisms of the domestic goat and man were compared and found to differ in the following ways:- 1. 1. In caprine erythrocytes the activities of the two enzymes of the phosphoglyceric acid cycle, 3,3-diphosphoglyceric acid phosphatase and diphosphoglyceric acid mutase, are only 1 or 2 per cent of the corresponding activities in human red cells. 2. 2. The erythrocytes of the goat have only about 2 per cent as much 3,3-diphosphoglyceric acid as those of man. 3. 3. There is considerably less lactic acid dehydrogenase activity in caprine red bloodcells. 4. 4. The haemoglobin from the goat is alkali stable. 5. 5. Caprine erythrocytes contain a significantly greater concentration of Na + and less K + than those of man. The activities of the other enzymes of glycolysis and the hexose monophosphate shunt, glucose consumption and lactate production, utilization of the hexose monophosphate shunt and sodium flux are similar in these two types of erythrocytes.
The Effect of Growth Environment on the Morphological and Extended Defect Evolution in GaN Grown by Metalorganic Chemical Vapor Deposition

The evolution of morphology and associated extended defects in GaN thin films grown on sapphire by metalorganic chemical vapor deposition (MOCVD) are shown to depend strongly on the growth environment. For the commonly used two-step growth process, a change in growth parameter such as reactor pressure influences the initial high temperature (HT) GaN growth mechanism. By means of transmission electron microscopy (TEM), atomic force microscopy (AFM), and high resolution X-ray diffraction (HRXRD) measurements, it is shown that the initial density of HT islands on the nucleation layer (NL) and subsequently the threading dislocation density in the HT GaN film may be directly controlled by tailoring the initial HT GaN growth conditions.
Linear Fitting with Missing Data for Structure-from-Motion

Several vision problems can be reduced to the problem of fitting a linear surface of low dimension to data. These include determining affine structure from motion or from intensity images. These methods must deal with missing data; for example, in structure from motion, missing data will occur if some point features are not visible in the image throughout the motion sequence. Once data is missing, linear fitting becomes a nonlinear optimization problem. Techniques such as gradient descent require a good initial estimate of the solution to ensure convergence to the correct answer. We propose a novel method for fitting a low rank matrix to a matrix with missing elements. This method produces a good starting point for descent-type algorithms and can produce an accurate solution without further refinement. We then focus on applying this method to the problem of structure-from-motion. We show that our method has desirable theoretical properties compared to previously proposed methods, because it can find solutions when there is less data present. We also show experimentally that our method provides good results compared to previously proposed methods.
Structure of a fluid dioleoylphosphatidylcholine bilayer determined by joint refinement of x-ray and neutron diffraction data. III. Complete structure.

We present in this paper the complete structure of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) in the L alpha phase (66% RH, 23 degrees C) obtained by the joint refinement of neutron and x-ray lamellar diffraction data. The structural details obtained have previously required a large number of neutron diffraction experiments, using numerous specifically-deuterated phospholipid isomorphs (Buldt et al., 1978. Nature (Lond.). 271:182–184). The joint-refinement approach minimizes specific deuteration by utilizing independent neutron and x-ray data sets. The method yields a quasimolecular structure consisting of a series of multiatomic fragments that are each represented by one or several Gaussian distributions whose positions and widths can be determined to within 0.06 to 0.52 A exclusive of the methylene region. The image of DOPC at 66% RH (5.36 +/- 0.08 waters per lipid) is consistent with many aspects of bilayer structure previously determined by structural and spectroscopic studies. The most striking feature of the structure is the large amount of transbilayer thermal motion suggested by the widths and overlaps of the Gaussian envelopes of the quasimolecular fragments. We discuss the "dynamic bilayer thickness" which describes the minimum effective thickness of the hydrocarbon permeability barrier in terms of the thermal motion of the water. A gradient of thermal motion exists that increases in either direction away from the glycerol backbone which is the most constrained portion of the bilayer. The steric interactions between headgroups of apposed bilayers, expected at the hydration level of our experiments, are clearly revealed. A useful consequence of the quasimolecular structure is that average boundaries within bilayers calculated using composition and volumetric data and ad hoc assumptions can be related to the positions of the principal structural groups. Several measures of "bilayer thickness" in common use can be identified as the positions of the cholines for Luzzati's d1 (Luzzati and Husson. 1962. J. Cell Biol. 12:207–219) and the glycerols for Small's dL (Small. 1967. J. Lipid Res. 8:551–556). We do not know if these relations will be true at other hydrations or for other lipids. Of particular interest is the fact that the position of the carbonyl groups marks the average hydrocarbon/headgroup boundary. It must be emphasized, however, that this region of the bilayer must be generally characterized as one of tumultuous chemical heterogeneity because of the thermal motion of the bilayer.
Angle-resolved x-ray photoemission and Auger emission from core levels of c ( 2 × 2 ) S and Se on Ni(001): Diffraction effects and single-scattering theory

Azimuthal anisotropies in x-ray photoemission from S $2p$ and Se $3p$ core levels of $c(2\ifmmode\times\else\texttimes\fi{}2)$ overlayers on Ni(001) are found to agree very well with single-scattering cluster calculations for the known geometries of these adsorbates. These results thus further confirm the utility of such analyses for surface-structure studies, although the sensitivity to adsorbate vertical position is not predicted to be high unless $z\ensuremath{\lesssim}0.5\ensuremath{-}1.0$ \AA{}. Analogous anisotropies observed in Se Auger electron intensities are found to be identical to those observed for Se $3p$ photoelectrons despite the inherent differences between their respective emission processes.
Understanding high performance work systems: The joint contribution of economics and human resource management

High performance work systems (HPWS) are organizations that utilize a fundamentally different approach to managing than the traditional hierarchical approach associated with mass production/scientific management. At the heart of this emerging approach is a radically different employer-employee relationship. Leading organizational behavior specialists believe that HPWS has the greatest potential to provide sustained competitive advantage to companies adopting it. Thus, human resource managers and scholars as well as economists ought to be very interested in it. While much has been written about HPWS in the human resource management (HRM) literature, economists’ attention to it has been practically nil despite the fact that organizational economics is a significant area within economics.
QSAR investigation of benzene toxicity to fathead minnow using molecular connectivity

The topological methods of molecular connectivity and kappa shape analysis have been applied to a set of 65 substituted benzenes and their toxicities to fathead minnow Pimephales promelas. The three variables 1χ, 1kα and 6χvp along with an ortho/para-dinitro indicator variable yield a QSAR equation with r = 0.940, s = 0.26 and F = 114. This equation is then used to estimate toxicities for 22 compounds not in the original data set. Twelve of the predicted compounds contain substituents in the original data set but 10 contain substituents new to the data, including fluoro-, cyano- and acyl-.
Consolidative therapy with stem cell transplantation improves survival of patients with mantle cell lymphoma after any induction regimen

Intensive induction regimen followed by high-dose chemotherapy and autologous stem cell transplantation (auto-SCT) is frequently used to improve outcomes in patients with mantle-cell lymphoma. The comparative impact of conventional vs intensive induction regimen before transplantation is unknown. Forty-eight patients with mantle-cell lymphoma receiving SCT at our institution between January 2000 and December 2010 were included in this study. At the time of initial presentation, 43 (89.5%) had stage IV disease and 18 (37.5%) received more than one chemotherapy regimen before transplantation. Forty patients underwent auto-SCT and 7 had allogeneic SCT (allo-SCT); 1 patient had an allo-SCT for relapsed disease after auto-SCT. At the time of this analysis (median follow-up of 6 years from diagnosis and 4 years from transplantation), 40 patients (88%) were alive with a 5-year disease-free survival of 74.8%. Age, disease stage, number of regimens pre-SCT, pre-SCT disease status, and type of SCT had no impact on long-term outcomes. Importantly, there were no differences among the types of induction regimen on outcomes in this cohort receiving SCT. Based on our data, we believe that future studies should focus on strategies to prevent disease relapse rather than comparing induction regimens before stem cell transplantation.
A Micro-Contact Model for Boundary Lubrication With Lubricant/Surface Physiochemistry

A model is developed to study the tribological behavior of sliding micro-contacts. It provides a building block to the modeling of tribo-contacts in boundary lubrication. Three contact variables are calculated at the asperity-level by relating them to the state of contact and the state of asperity deformation. These variables include micro-contact friction force, load carrying capacity and flash temperature. The deformation of the contacting asperity is either elastic, elasto-plastic, or fully plastic. Furthermore, the asperity may be covered by the lubricant/additive molecules adsorbed on the surface, protected by a surface oxide layer or other chemical reaction films, or in direct contact with no boundary protection. The possibility of the contact in each of these three states is represented by a corresponding contact probability. A numerical method is developed to determine the contact state and contact variables in the course of an asperity-to-asperity collision. The asperity flash temperature, which governs the kinetics of lubricant/surface adsorption/desorption, is first calculated by integrating the Jaeger equation over the contact area and in time. Then, the probability of contact covered by an adsorbed film is determined using the Volmer adsorption isotherm, and the probability of contact protected by the oxide layer is estimated using a classical wear theory For elastic/elasto-plastic deformation of the asperity, the friction coefficient is given by the linear combination of the friction coefficients of the three contact states with their contact probabilities as the weighting factors. For fully plastic deformation of the asperity, the contact pressure and friction force become dependent of each other The shear stress is approximated by a linear function of the contact probabilities, and the contact pressure and friction coefficient then calculated. Meanwhile, the influence of fresh surface generation due to plastic flow on the contact probabilities is also modeled. Insights are provided into the asperity collision through numerical studies of a sample problem. In addition, parametric studies are carried out to analyze the effects of lubricant and surface parameters on the micro-contact severity and its load capacity.
Line Growth on the H/Si(100)-2 × 1 Surface: Density Functional Study of Allylic Mercaptan Reaction Mechanisms

The growth of molecular lines on the Si(100)-2 × 1 surface is an area of intense interest due to its possible application to the microelectronics industry. While many molecules have been found to g...
SU-FF-T-297: Monitor Unit Calculation in Eclipse Proton Therapy Treatment Planning

Purpose: To evaluate the Monitor Unit calculation algorithm in Eclipse proton therapytreatment planning.Method and Materials: The Eclipse (Varian) treatment planning system is commissioned for eight double scattering options, i.e. eight range modulator and second‐scatterer combinations. When supplying the commissioning beam data in cGy/MU, Eclipse calculates the Monitor Units delivering the prescribed dose. We compare this calculated output to measurements in water for fields of varying range and modulation width. The output variation with source‐to‐skin distance as well as with aperture size is investigated. To evaluate the effect of the range compensator and target inhomogeneities on the delivered dose, clinical plans are recalculated in a water phantom — both with and without range compensator — and the dose‐per‐MU in the normalization point is compared to measurement. Results: Eclipse creates the spread‐out Bragg peak by adding the individual pristine peaks according to their weight and position as defined in the user‐supplied range‐modulator wheel file. The observed output strongly depends on the range modulator wheel layout. By optimizing the file in combination with the user‐supplied output for the pristine peaks a good agreement with the measured output is obtained. The agreement is best for small modulation width and worsens continuously with increasing modulation width, especially for the options with a higher range. The Eclipse dose decreases with source‐to‐skin distance as expected, but the measured decrease in output with aperture diameter is underestimated. Conclusion: The accuracy of the Eclipse output calculation depends strongly on the accuracy of the beam data supplied. Optimizing the beam data to minimize the difference between planned and measured output typically leads to an agreement within ±5%.
The kinetics and mechanism(S) of nucleophilic attack by catecholate anion on epibromohydrin‐d2

The reaction which forms hydroxymethylbenzodioxane from epibromohydrin and catecholate anion was examined by ultraviolet spectroscopy for the kinetics and by proton nuclear magnetic resonance spectroscopy to follow the fate of CD2 from reactant to product. Over the practical temperature range it was found that both CH2 positions in the epihalohydrin are attacked by catecholate anion to give product. Therefore, the difference in energy for the two pathways was small. The individual rate constants were obtained from the total rate constants. Further, the individual ΔH‡ and ΔS‡ values were calculated. It was found that the pathway of higher ΔH‡ had the less negative ΔS‡, which explains the subtlety of two mechanisms being operative over the available temperature range. Interestingly, it proved impossible to prepare epibromohydrin with two deuteriums at only one position in what appeared to be a relatively straightforward synthesis.
An Evaluation of the Duke Criteria in 25 Pathologically Confirmed Cases of Prosthetic Valve Endocarditis

Six studies have compared the sensitivity of the Duke criteria with that of the Beth Israel criteria for the diagnosis of infective endocarditis without attempting to distinguish between native valve and prosthetic valve cases. After reviewing clinical data from 372 cases of suspected prosthetic valve endocarditis, we selected 25 cases in which pathological confirmation of prosthetic valve endocarditis was obtained. By using the Duke criteria and then the Beth Israel criteria, we reassigned a diagnostic classification to these 25 cases on the basis of clinical parameters alone. Using the Duke criteria, we correctly classified 19 cases (76%) as definite endocarditis and rejected none, while the Beth Israel criteria correctly classified six cases as probable endocarditis (24%) and rejected five cases (20%). Similar to previous investigators who examined the diagnostic sensitivity of the Duke criteria and Beth Israel criteria, we found that the Duke criteria appear more sensitive than the Beth Israel criteria in pathologically confirmed cases of prosthetic valve endocarditis.
The three horizons of educational change

Purpose – This paper aims to describe three potential disruptions that could close the current era of public and higher education and open potentially new eras.Design/methodology/approach – The paper employs secondary research, scanning, and analysis.Findings – The three potential disruptions for education are: the availability of almost unlimited information on the internet; open source education leading to the decoupling of learning from credentialing; and the ability to understand the learning process in general and that of every learner through the application of learning analytics on the data being generated by students learning online.Research limitations/implications – These findings are conjectures. They are scenarios of some relatively current and longer‐term futures; they are not formal predictions. But they might stimulate further reflection and research while the community monitors whether these scenarios will occur or not.Practical implications – Educational institutions should monitor the de...
Legal means of protecting computer software

Each year, more and more computer software is produced and made available to public industry. Concerns over ownership rights of this software surface frequently. These disputes can lead to major lawsuits, some of which have changed the protection laws of software. This article attempts to look at some of the ownership problems and if possible, suggest some solutions.
Characterization of functionally distinct mitochondrial subpopulations

Mitochondrial stress results in changes in mitochondrial function, morphology and homeostasis (biogenesis, fission/fusion, mitophagy) and may lead to changes in mitochondrial subpopulations. While flow cytometric techniques have been developed to quantify features of individual mitochondria related to volume, Ca2+ concentration, mtDNA content, respiratory capacity and oxidative damage, less information is available concerning the identification and characterization of mitochondrial subpopulations, particularly in epithelial cells. Mitochondria from rabbit kidneys were stained with molecular probes for cardiolipin content (nonyl acridine orange, NAO) and membrane potential (tetramethylrhodamine, TMRM) and analyzed using flow cytometry. We validated that side scatter was a better indicator of volume and that as side scatter (SSC) decreased mitochondrial volume increased. Furthermore, those mitochondria with the highest NAO content had greater side scattering and were most highly charged. Mitochondria with average NAO content were of average side scattering and maintained an intermediate charge. Those mitochondria with low NAO content had minimal side scattering and exhibited minimal charge. Upon titration with the uncoupler carbonylcyanide-4-(trifluoromethoxy)-phenylhydrazone (FCCP), it was found that the high NAO content subpopulations were more resistant to uncoupling than lower NAO content populations. Ca2+-induced swelling of mitochondria was evaluated using probability binning (PB) analyses of SSC. Interestingly, only 30 % of the mitochondria showed changes in response to Ca2+, which was blocked by cyclosporine A. In addition, the small, high NAO content mitochondria swelled differentially in response to Ca2+ over time. Our results demonstrate that flow cytometry can be used to identify mitochondrial subpopulations based on high, mid and low NAO content and/or volume/complexity. These subpopulations showed differences in membrane potential, volume, and responses to uncoupling and Ca2+-induced swelling.
Preventing sciatic nerve injury from intramuscular injections: literature review.

Background. Injury to the sciatic nerve (SN) is a serious complication of intramuscular injection. Aim. The purpose of this paper was to identify factors associated with such iatrogenic injury in adults and measures that nurses may take to prevent it. Method. A review of the English language literature was undertaken to identify applicable research studies and determine the information that currently is being disseminated on relevant injection procedure. Legal databases were also searched for pertinent court decisions. Discussion. The evidence is that injury to the SN is associated with use of the dorsogluteal (DG) site for injection. The choice of site for injection must be based on good clinical judgment, using the best evidence available and individualized assessment of the client. There is wide agreement in the literature that the ventrogluteal site is preferable. If the DG site is chosen, the nurse must have a full appreciation of the anatomy of the site and proximate anatomic structures, be able to accurately identify anatomic landmarks and site boundaries, and administer the injection with meticulous technique. Not only may SN injury resulting from erroneous injection cause client discomfort, morbidity and lasting disability, but it also provides the basis for nursing negligence suits. Conclusion. The research base for intramuscular injection is limited. Studies on various aspects of the procedure need to be carried out to provide support for clinical guidelines.
Readings in Place: Recent Publications in Southwestern Literature and Studies

Defining the region known as the Southwest is a project that keeps many geographers pleasantly and securely employed. As D. W. Meinig famously quipped, "The Southwest is a distinctive place to the American mind but a somewhat blurred place on American maps, which is to say that everyone knows that there is a Southwest but there is little agreement as to just where it is" (3). In spite of the great variability, complexity, and subjectivity of definitions geographers promulgate, however, when one distills the matter the region is nearly always defined along the intersection of two axes, one cultural and the other natural. Certain characteristics of these two axes are obvious in the six
A modified method for determining available lysine in protein recovered from heat treated potato juice

Abstract A dialysis pretreatment to remove low molecular weight interfering compounds from potato protein water prior to measuring its lysine availability is described. After dialysis the ϵ-trinitrophenyl- l -lysine showed excellent correlation with the magnitude of heat treatment the protein water received. Conversely, analysis of the same sample without pretreatment yielded erratic results.
Response of a pulse combustor to changes in fuel composition

The response of a valved pulse combustor to changes in the homogeneous chemical ignition delay time has been examined. Guided by detailed chemical kinetic modeling, experiments were performed which measured the response of this combustor using two fuels having significantly different ignition delay times. It was found that differences in the reaction kinetics of the fuel caused changes in the coupling between the heat release and the resonant acoustic waves which control the pulsating combustion process. Furthermore, the change in this coupling caused corresponding changes in the fuel and air injection process—hence, the strength of the resonant pressure wave. This complicated interaction resulted in a modification of the combustor's lean stability limit which was contrary to predictions based on chemical kinetics arguments alone.
General fast generation of random variables for discrete distributions

Recently a new method, the alais method has been introduced for generating a discrete, finite valued distribution (1, 2). The method is exceptionally fast and can be broadly applied. It should have wide appeal. The purpose of this note is to introduce the method, place it in prospective with other fast, generally applied methods and to provide a Fortran program to generate constants needed by the method for any given distribution.
Quantum dots for tracking dendritic cells and priming an immune response in vitro and in vivo.

Dendritic cells (DCs) play a key role in initiating adaptive immune response by presenting antigen to T cells in lymphoid organs. Here, we investigate the potential of quantum dots (QDs) as fluorescent nanoparticles for in vitro and in vivo imaging of DCs, and as a particle-based antigen-delivery system to enhance DC-mediated immune responses. We used confocal, two-photon, and electron microscopies to visualize QD uptake into DCs and compared CD69 expression, T cell proliferation, and IFN-γ production by DO11.10 and OT-II T cells in vivo in response to free antigen or antigen-conjugated to QDs. CD11c+ DCs avidly and preferentially endocytosed QDs, initially into small vesicles near the plasma membrane by an actin-dependent mechanism. Within 10 min DCs contained vesicles of varying size, motion, and brightness distributed throughout the cytoplasm. At later times, endocytosed QDs were compartmentalized inside lysosomes. LPS-induced maturation of DCs reduced the rate of endocytosis and the proportion of cells taking up QDs. Following subcutaneous injection of QDs in an adjuvant depot, DCs that had endocytosed QDs were visualized up to 400 µm deep within draining lymph nodes. When antigen-conjugated QDs were used, T cells formed stable clusters in contact with DCs. Antigen-conjugated QDs induced CD69 expression, T cell proliferation, and IFN-γ production in vivo with greater efficiency than equivalent amounts of free antigen. These results establish QDs as a versatile platform for immunoimaging of dendritic cells and as an efficient nanoparticle-based antigen delivery system for priming an immune response.
A rotationally biased upwind difference scheme for the euler equations

The upwind difference schemes of Godunov, Osher, Roe and van Leer are able to resolve one-dimensional steady shocks for the Euler equations within one or two mesh intervals. Unfortunately, this resolution is lost in two dimensions when the shock crosses the computing grid at an oblique angle. To correct this problem, a numerical scheme is developed which automatically locates the angle at which a shock might be expected to cross the computing grid then constructs separate finite difference formulas for the flux components normal and tangential to this direction. Numerical results are presented which illustrate the ability of this new method to resolve steady oblique shocks.
Railroad Energy Efficiency in the United States: Analytical and Statistical Analysis

AbstractThis paper provides information about railroad fuel efficiency. Two methods of estimating railroad fuel consumption are demonstrated: (1) an analytical procedure based on train resistance factors, speeds, changes in elevation, and car weights; and (2) a statistical procedure that utilizes observed data. Both procedures are used to estimate the efficiencies of coal, grain, iron ore, and other commodity shipments. The two methods produce similar (but not identical) results. The analytical procedure illustrates the underlying forces that affect fuel efficiency and provides a benchmark for the statistical model.
Long-term follow-up of patients undergoing reoperation for recurrent carotid artery disease.

Abstract Purpose: We examined the perioperative course and long-term fate of individuals who required reoperation for recurrent carotid artery disease. Methods: The records of 2289 patients undergoing 2961 consecutive operations during a 22-year period were reviewed. Forty-two patients (1.8%) who underwent reoperations were studied. Forty-seven redo carotid artery reconstructions were performed on these 42 patients for neurologic symptoms or asymptomatic high-grade stenosis. Long-term follow-up was obtained on 41 of 42 patients (mean 54 months; range 9 to 202 months). Results: The forty-seven reoperations consisted of endarterectomy with patch angioplasty ( n = 36), saphenous vein or polytetrafluoroethylene interposition graft ( n = 7), or simply vein or polytetrafluoroethylene patch angioplasty ( n = 4). There were no perioperative strokes or deaths. Three patients had perioperative transient ischemic attacks and two had cranial nerve injuries. The incidence of late failure after secondary surgery was 19.5% (8/41 patients). These failures consisted of one stroke, three transient ischemic attacks, and four asymptomatic occlusions. One tertiary carotid artery reconstruction was performed for a restenosis at the site of the secondary reconstruction. Conclusion: The factors responsible for the high incidence of late failures after secondary carotid artery reconstruction are unclear. Reoperation for recurrent carotid artery disease appears less durable than primary carotid endarterectomy. Close postoperative surveillance is recommended after carotid artery reoperation. (J VASC SURG 1993;18:991-1001.)
Cochlear function in mice following inhalation of brevetoxin-3

Brevetoxin-3 was shown previously to adversely affect central auditory function in goldfish. The present study evaluated the effects of exposure to this agent on cochlear function in mice using the 2f1-f2 distortion-product otoacoustic emission (DPOAE). Towards this end, inbred CBA/CaJ mice were exposed to a relatively high concentration of brevetoxin-3 (~400 μg/m3) by nose-only inhalation for a 2-h period. Further, a subset of these mice received a second exposure a day later that lasted for an additional 4 h. Mice exposed only once for 2 h did not exhibit any notable cochlear effects. Similarly, mice exposed two times, for a cumulative dose of 6 h, exhibited essentially no change in DPOAE levels.
Central Government Policies towards Declining Urban Economies in Western Europe and the United States of America

Most large urban areas in the advanced market-economy nations of the West are experiencing a decentralization trend, with population and industrial employment moving from central city to suburb. In some large metropolitan areas the entire area is losing population, and employment is either growing very slowly or declining. In the United States of America and the United Kingdom these trends have triggered a substantial amount of public concern and debate and a variety of policies designed to focus on the problems of large urban economies. In most European countries, however, metropolitan population and employment stabilization or decline are either not perceived as problems or are just beginning to be seen as such. Indeed, in many of these countries the decentralization of population and employment from large urban areas is seen as consistent with the long-term objectives of regional policy.This article first summarizes urban-area population and employment trends in the USA, the UK, the Netherlands, Sweden...
Sixth annual summer school held at NIST

Abstract The National Institute of Standards and Technology's Center for Neutron Research (NCNR) held its sixth annual Summer School on Neutron Scattering at the reactor on the NIST campus in Gaithersburg, Majland, from June 5–9, 2000. The course this year focused on the complementary techniques of small-angle neutron scattering (SANS) and neutron reflectometry (NR) and was attended by an enthusiastic group of 32 graduate students and postdocs, predominantly from university chemical engineering and materials science departments. The course was intended to providepotential new users of these techniques with a basic understanding of the fundamental concepts and methodology, along with training in the use of the SANS and NR instruments at the NCNR. By devoting an entire week to just these two techniques, both theoretical and practical aspects, as well as applications, were covered in some depth by the sixteenNCNR staff members who lectured or assisted with the demonstrations and experiments at the NCNR's two...
Vibrational CD of biopolymers

Circular dichroism measurements in the infrared provide new insight into polypeptide structure and promise more detailed analyses of protein secondary structure.
Cardiovascular responses elicited by electrical and chemical stimulation of the rostral medullary raphe of the rabbit

Abstract Electrical stimulation of the rostral medullary raphe (RMR) of the rabbit elicited pressor responses that were accompanied by tachycardia or bradycardia. Stimulation of dorsal sites (the dorsal raphe obscurus) evoked a pressor/tachycardia response and stimulation of ventral sites (the ventral raphe obscurus, raphe magnus and raphe pallidus) produced a pressor/bradycardia response. Electrical stimulation of the RMR after sinoaortic denervation led to an increase in the magnitude of the pressor response elicited from all stimulation sites, a decrease in the magnitude of the bradycardia produced by stimulation at the ventral sites, but had no effect upon the magnitude of the tachycardia observed from stimulation of the dorsal sites. These findings suggest that electrical stimulation of the dorsal sites leads to inhibition of the cardiomotor component of the baroreceptor reflex. The results of vagal blockade experiments demonstrated that baroreceptor attenuation of the pressor responses at ventral sites was mediated primarily by parasympathetic input to the heart. Chemical stimulation of the RMR with l -glutamate also led to a pressor/tachycardia response at the dorsal sites and a pressor/brachycardia response at the ventral sites. This finding provides evidence that neuronal cell bodies, not axon of passage, mediated the responses elicited by electrical stimulation.
Pre‐Marital Counseling and Examination

The author's system of premarital counseling and examination is presented. The program consists of four visits before the marriage and one following. The first visit introduces the couple to the contractual elements of marriage; the second and third are used for taking the medical history and physical examination. The fourth visit summarizes the findings and introduces a program for beginning the marriage. The fifth visit occurs between the eighth and twelfth weeks of the marriage to help resolve problems which become apparent in the early weeks of married living. The work sheets and sample examinations are appended.
Descending pathways to the spinal cord: II. Quantitative study of the tectospinal tract in 23 mammals.

To study the early evolution of the mammalian motor systems, we have collected quantitative data on the nuclear origins of tracts descending into the spinal cord in 99 individuals representing 23 species of mammals and one species of reptile. In each individual, the spinal cord was hemisected at the C1-C2 junction and raw HRP immediately applied to the cut fibers. After a 3-day survival period, brain and spinal cord sections were treated with conventional tetramethylbenzidine procedures. In every case, this procedure resulted in heavy retrograde labeling of neural somata throughout the neuraxis from coccygeal cord to cerebral neocortex. Many thousands of supraspinal neurons were vividly labeled within at least 27 discrete cell groups in every mammal (Nudo and Masterton, '88). Despite the vast number and wide diversity of heavily labeled neurons, however, relatively few labeled somata were found in the superior colliculus. The total number of labeled cells in the tectum contralateral to the hemisection was highest in the cat (909) and second highest in the raccoon (628). In the remaining animals, the number was considerably less--averaging only 243 in the 23 mammalian species, 193 in the 21 noncarnivores, and 95 in the iguana. In 7 species of primates the average was 220, and in 3 species of Old World monkeys the average was 142. This wide variation in the number of tectospinal neurons is not related to body size, brain size, or absolute and relative tectum size. Arranging the animals in order of their kinship or recency-of-last-common-ancestor with Man, the average number of labeled tectal cells tends to decrease slightly, whereas arranging the same animals in order of their kinship with the cat or raccoon shows a marked and statistically reliable increase. Neither the evolutionary increase in the tectospinal tract along the Carnivora lineage nor the slight decrease along Man's lineage is altered by mathematical corrections for allometric or scaling factors. Of an array of morphological, visual, motor, and ecological traits tested statistically as a possible source of the variation in size of the tectospinal tract, only a primarily carnivorous feeding preference was found to be reliably related. The relatively small number of tectospinal fibers in most mammals in our sample, including the primates, suggests that the tectospinal tract in Man may be quite small, perhaps far too small to warrant continuing description as a "major descending tract."
Predetection fusion with feedback and projection

The optimal (feedback-free) fusion rule for binary hypothesis testing consists of (binary) Likelihood Radio Quantizers (LRQs) at the peripheral sensors and a LRQ at the fusion, when the observations are statistically independent from sensor to sensor. Feedback introduces correlation between local and global decisions that complicates the optimal fusion design. In this paper we consider the optimal fusion design in the presence of non-hierarchical feedback. Optimal fusion design requires the explicit knowledge of the underlying statistics. The design of feedback-free fusion is considered under reduced statistical knowledge using projection. The constrained optimal linear centralized and distributed fusion rules are derived. Fusion design with projection only requires knowledge of the first two moments of the data and is applicable in cases of limited statistical information about the operational statistics.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Cyclic AMP regulate adenovirus mediated inducible nitric oxide synthase expression and CMV promoter activity in cultured hepatocytes

Abstract We examined effects of cyclic AMP on adenovirus mediated inducible nitric oxide synthase expression in primary rat hepatocytes. In AdCMV-hiNOS infected hepatocytes, dbcAMP at a concentration of 1–100 μM inhibited nitrite and nitrate accumulation, iNOS protein and iNOS mRNA expression. At a concentration of 1–5 mM, dbcAMP increased iNOS activity and expression. Both the inhibitory and stimulatory effects of cAMP on adenovirus mediated iNOS expression were dose dependent. This dual effect of cAMP on iNOS activity and expression can be accounted by its effect on CMV promoter activity since dbcAMP significantly inhibited CMV promoter activity in hepatocytes at low concentration and induced it at high concentration. We concluded that dbcAMP can regulate adenovirus-mediated human iNOS expression in primary hepatocytes by the mechanisms regulating the CMV promoter used in the adenovirus vector.
Joint and several liability for toxic torts

Abstract Joint and several liability can be an effective instrument for regulating the risk of and compensating the losses from toxic torts. The doctrinal evolution of the joint and several rule from one concerned primarily with concerted and joint ventures to its expansive, modern application in toxic tort cases which involve numerous, independently operated firms is sketched. Fairness and efficiency objections are discussed and brief concluding observations are given.