cssi/SciSciGPT-SciSciNet huggingface dataset:
The intersection of free submonoids of a free monoid is free

Several necessary and sufficient conditions exist for a submonoid of a free monoid to be free. For a few, see [1] through [6]. This short note uses one of these conditions, due to Schutzenberger (see [2], p. 119, or [4], Theorem 1.4) to establish that the intersection of free submonoids of a free monoid M is again free. Schutzenberger's condition is also proven in this note.
Influence of prostaglandin synthetase inhibitors on the renal effects of histamine.

The increase in renal blood flow and accompanying increase in excretion of electrolytes (e.g., Na+, Ca2+, and other osmolar constitutents) produced by intra-renal arterial infusion of histamine in dogs are reduced by the inhibitors of cyclooxygenase activity, indomethacin and RO 20-5720, given intravenously. This suggests the possibility that histamine might be acting in conjunction with the renal prostanoids, either by stimulating their release by activating prostaglandin synthesis, or by acting at the PG receptor sites in a similar manner.
Papaverine-induced metabolic alterations in perfused canine and porcine liver

Abstract Papaverine was given to perfused porcine and canine livers to assess the effect of this antispasmodic on hepatic viability. Papaverine decreased oxygen consumption, portal venous resistance (PVR), and perfusate pyruvate while increasing perfusate lactate. After approximately 10 min, these parameters, except for perfusate lactate, began to return to their pre-papaverine values. The reduction of oxygen consumption accompanied by the output of lactate indicated a shift to anaerobic metabolism resulting from papaverine administration. These phenomena occurred in both species even though the reduction in PVR was much less pronounced in the porcine liver. The decrease in perfusate pyruvate was found to depend on pre-existing levels of pyruvate in the perfusate; the equations governing this behavior were similar in the canine and porcine livers. There was no correlation between change in lactate output and initial values of lactate; however, the change in perfusate lactate could be correlated to the change in perfusate pyruvate. Thus, the changes in pyruvate and lactate occurring upon papaverine administration are related to initial perfusate pyruvate, the levels of which may reflect the redox state of the hepatocytes. Papaverine did not improve the perfusion characteristics of porcine livers other than to slightly decrease PVR. Irreversible outflow block could be prevented or delayed by papaverine in canine preparations, however, when this drug was given at the onset of PVR rise. Thus, papaverine may be effective in perfusion and preservation of canine livers and other organs which undergo phenomena similar to outflow block due to venous sphincters.
Correlation inequalities for Ising spin lattices

A change of spin representation is used to present expectation inequalities on Ising lattices directly as sums of terms of like sign. The technique is extended to correlation inequalities by introducing replica variables which convert correlations into expectations on a larger space. Second order correlations are analyzed in full from this viewpoint, recovering the FKG set, among others. Third order correlations are examined in some detail, and the sign of the multi-site Ursell correlationsF3,F4,F6 established under appropriate restrictions.
Molecular characterization and genetic mapping of two clusters of genes encoding chlorophyll a/b-binding proteins in Lycopersicon esculentum (tomato).

Abstract We have constructed a tomato genomic library in the λ Charon 4 phage vector. The library was screened with a pea cDNA probe encoding a chlorophyll a / b -binding protein (CAB), and several recombinant phages containing tomato CAB genes were isolated and characterized by restriction mapping, heteroduplex analysis and nucleotide sequencing. Two phages with overlapping segments of the tomato genome contain a total of four CAB genes, all arranged in tandem. A third phage contains three CAB genes, two arranged in tandem and one in opposite orientation, and an additional, truncated CAB gene. Genetic mapping experiments showed that the four CAB genes on the first two phages belong to a locus, previously designated Cab -1, on chromosome 2. The CAB genes from the third phage belong to the Cab -3 locus on chromosome 3. Complete sequence determination of two CAB genes, one from each locus, and additional sequence determination of about 50% of each of the other five CAB genes showed that each gene within a CAB locus is more similar to other CAB genes in the same locus than it is to the CAB genes from the second locus. Furthermore, the polypeptides encoded by Cab -1 genes diverge significantly from those encoded by Cab -3 genes in the domains of transit peptide and the N terminus of the mature polypeptide but are essentially identical in the rest of the sequence.
Transforming Ourselves in the Process of Educating Our MBA Students: A Response to Professor Mitroff’s Open Letter to the Deans and the Faculties of American Business Schools

This article is a narrative exploration of ways to strengthen and deepen the MBA curriculum for the future. We argue that interdisciplinary approaches including anthropology, sociology, and the humanities into the curriculum will give a broader-based understanding of the complexities of ethical management and leadership. It is important to educate students not merely to maximize profits but also to face issues such as global sustainability, global prosperity, corporate social responsibility, and other challenges of being a global player. The humanities and social sciences in addition to the traditional MBA curriculum provide us with auxiliary tools for more complex problem solving. These broader dimensions should be integrated into every course to provide a robust grounding for our students. It provides our new MBA graduates with the requisites to face emerging challenges in the workplace today and our global future.
Three-Dimensional Photopatterning of Hydrogels Containing Living Cells

Recent advances in tissue engineering have leveraged progress in both polymer chemistry and cell biology. For example, photopolymerizable biomaterials have been developed that can be used to photoencapsulate cells in peptide-derivatized hydrogel networks. While these materials have been useful in bone, cartilage and vascular tissue engineering, they have limited applicability to more complex tissues that are characterized by precise cell and tissue organization (e.g., liver, kidney). Typically, the tissue shape has been defined solely by the container used for photopolymerization. In this paper, we describe the use of photolithographic techniques to broaden the capability of photopolymerizable PEG-based biomaterials by inclusion of structural features within the cell/hydrogel network. Specifically, we describe the development of a photopatterning technique that allows localized photoencapsulation of live mammalian cells to control the tissue architecture. In this study, we optimized the effect of ultraviolet (UV) exposure and photoinitiator concentration on both photopatterning resolution and cell viability. With regard to photopatterning resolution, we found that increased UV exposure broadens feature size, while photoinitiator concentration had no significant effect on patterning resolution. Cell viability was characterized using HepG2 cells, a human hepatoma cell line. We observed that UV exposure itself did not cause cell death over the doses and time scale studied, while the photoinitiator 2,2-dimethoxy-2-phenyl-acetophenone was itself cytotoxic in a dose-dependent manner. Furthermore, the combination of UV and photoinitiator was the least biocompatible condition presumably due to formation of toxic free radicals. The utility of this method was demonstrated by photopatterning hydrogels containing live cells in various single layer structures, patterns of multiple cellular domains in a single “hybrid” hydrogel layer, and patterns of multiple cell types in multiple layers simulating use in a tissue engineering application. The combination of microfabrication approaches with photopolymerizable biomaterials will have implications in tissue engineering, elucidating fundamental structure–function relationships of tissues, and formation of immobilized cell arrays for biotechnological applications.
Evidence for non-uniform dispersal in the biological invasions of two naturalized North American bird species

Most previous attempts to model the geographical range expansion of an invading species assume random dispersal of organisms through a homogeneous environment. These models result in a series of uniformly increasing circles radiating out from the centre of origin over time. Although these models often give reasonable fits to available data, they do not typically include mechanisms of dispersal. Alternatively, models that include assumptions of non-random dispersal and a heterogeneous environment inevitably result in an anisotropic or jagged invasion front. This front will include propagules of pioneer individuals for the expanding species. Existing data from biological invasions reveal that the spatial structure of an invading species usually exhibits these propagules. Using population data gathered from the past century, we investigated the propagules of two North American invading bird species: the European starling (Sturnus vulgaris Linnaeus), and the house finch (Carpodacus mexicanus Muller), and found a correlation between propagule location and habitat quality. These results suggest that dispersing individuals seek out favourable habitat and remain there, thus introducing a possible mechanism for explaining non-uniform dispersal during invasions. When combined with results from other studies, our results suggest that propagules provide starting points for future population expansion of an invading species.
Comparisons with a control in two‐way and one‐way designs, and determining whether the most effective treatment has been selected with probability 1‐α

This paper deals with three problems related to comparing independent treatment groups to a control. The first goal is to extend Dunnett's solution to two-way designs. Let μjk (j = 1, …, J; k = 1, …, K) be the means of JK independent normal distributions. Percentage points of the multivariate t distribution are supplied that provide two-sided 1–α simultaneous confidence intervals for μjk – μjk (j = 1, …, J – 1; k = 1, …, K) when the variances and sample sizes are equal. Next, approximate methods for handling both unequal variances and unequal sample sizes are suggested and studied via simulations. A new two-stage procedure is also described where the probability coverage is at least 1–α and the length of the confidence intervals are fixed in advance by the experimenter, even when the variances are unequal. Using real data, implications of the new results are illustrated for situations where a researcher is interested in performing multiple comparisons with the ‘best’ treatment group, where ‘best’ is defined to be the treatment group with the largest mean. In particular, the results in this paper can be used to determine whether the most effective of several treatments was correctly identified with probability 1–α.
EXPERIMENTAL INVESTIGATION OF A TURBULENT FLOW IN THE VICINITY OF AN APPENDAGE MOUNTED ON A FLAT PLATE

Experimental measurements were carried out in an incompressible three-dimensional turbulent shear layer in the vicinity of an appendage mounted perpendicular to a flat plate. The thickness of the turbulent boundary layer as it approached the appendage leading edge was 76 mm or 1.07 times the maximum thickness of the appendage. As the oncoming boundary layer passed around the appendage, a strong secondary flow was formed which was dominated by a horseshoe root vortex. This secondary flow had a major effect in redistributing both the mean flow and turbulence quantities throughout the shear layer, and this effect persisted to a significant degree up to at least three chord lengths downstream of the appendage leading edge.
Symbolic modeling and dynamic simulation of robotic manipulators with compliant links and joints

Abstract The explicit, non-recursive symbolic form of the dynamic model of robotic manipulators with compliant links and joints are developed based on a Lagrangian-assumed mode of formulation. This form of dynamic model is suitable for controller synthesis, as well as accurate simulations of robotic applications. The final form of the equations is organized in a form similar to rigid manipulator equations. This allows one to identify the differences between rigid and flexible manipulator dynamics explixitly. Therefore, current knowledge on control of rigid manipulators is likely to be utilized in a maximum way in developing new control algorithms for flexible manipulators. Computer automated symbolic expansion of the dynamic model equations for any desired manipulator is accomplished with programs written based on commercial symbolic manipulation programs (SMP, MACSYMA, REDUCE). A two-link manipulator is used as an example. Computational complexity involved in real-time control, using the explicit, non-recursive form of equations, is studied on single CPU and multi-CPU parallel computation processors.
Aging and Lymphocyte Subsets in the Spleen and Peripheral Blood of the Sprague-Dawley Rat

AbstractThis study was undertaken to determine the effects of aging on lymphocyte subsets in the peripheral blood and spleens of Sprague-Dawley rats. Rats aged 3, 13 and 26 months were used in the study. Analyses of dual labeled lymphocytes from the 26 month animals show decreases in the numbers of lymphocytes due to decreased cellularity (spleen) or reduced lymphocyte percentages within the total white blood cell population (peripheral blood). In the spleens and blood of the oldest rats, there were reduced numbers of Total T, T helper/ amplifier (Th/a), virgin Th, and natural killer (NK) cells. Other changes were observed in the spleen but not peripheral blood. The numbers of T cytotoxic/suppressor cells (Tc/s) B cells, “autoimmune” B cells and NK cells were reduced in the spleen but remained within normal limits in peripheral blood. The data show aging exerts different effects on the peripheral blood and splenic compartments of the immune system. These differences may have teleological significance in r...
Shutting down welfare: Two cases from America's past

Abstract Champions of the recent decentralization of welfare claim that local governments will he more responsive to the needs of citizens, while critics raise the specter of a race to the bottom as local governments compete to deter the poor. Nineteenth century American poor relief, financed and operated by local governments, provides an illuminating test case. Evidence from two nineteenth century welfare reform movements in New York State suggests that in the absence of barriers to mobility, local governments were driven to abandon policies which might have promoted a long run reduction in statewide poverty and public welfare costs in favor of those which had the strongest deterrent effect.
Circular Structures in Retroviral and Cellular Genomes

A computer program for predicting DNA bending from nucleotide sequence was used to identify circular structures in retroviral and cellular genomes. An 830-base pair circular structure was located in a control region near the center of the genome of the human immunodeficiency virus type I (HIV-I). This unusual structure displayed relatively smooth planar bending throughout its length. The structure is conserved in diverse isolates of HIV-I, HIV-II, and simian immunodeficiency viruses, which implies that it is under selective constraints. A search of all sequences in the GenBank data base was carried out in order to identify similar circular structures in cellular DNA. The results revealed that the structures are associated with a wide range of sequences that undergo recombination, including most known examples of DNA inversion and subtelomeric translocation systems. Circular structures were also associated with replication and transposition systems where DNA looping has been implicated in the generation of large protein-DNA complexes. Experimental evidence for the structures was provided by studies which demonstrated that two sequences detected as circular by computer preferentially formed covalently closed circles during ligation reactions in vitro when compared to nonbent fragments, bent fragments with noncircular shapes, and total genomic DNA. In addition, a single T → C substitution in one of these sequences rendered it less planar as seen by computer analysis and significantly reduced its rate of ligase-catalyzed cyclization. These results permit us to speculate that intrinsically circular structures facilitate DNA looping during formation of the large protein-DNA complexes that are involved in site- and region-specific recombination and in other genomic processes.
The diversity of Scenedesmus and Desmodesmus (Chlorophyceae) in Itasca State Park, Minnesota, USA

Abstract Species of Scenedesmus and Desmodesmus are ubiquitous in freshwater ecosystems. However, phenotypic plasticity coupled with the minute variations between named species make the identification of taxa by light microscopy extremely difficult, especially from field samples. As a result, the actual level of diversity and distributions of these genera are not known. In this study, the diversity of Scenedesmus and Desmodesmus from Itasca State Park (ISP), Minnesota, USA was studied using culture techniques followed by light microscopy and internal transcribed spacer (ITS-2) rDNA sequence analysis. From 100 characterized isolates of Scenedesmus, Desmodesmus and allied isolates, 34 different sequence types were detected, 24 of which are different enough from each other to correspond to distinct taxa. This diversity greatly exceeds that described for these genera in previous studies of ISP algae using light microscopy alone. The sequences of five ISP isolates identically matched those of previously descri...
Bilirubin excretion in the dog

Summary Fecal and urinary urobilinogen excretion levels were determined in normal, healthy, mongrel dogs. Unlike the human, in the dog most of the theoretical daily production of bile pigment can be recovered in the feces and urine. Following ligation of the common bile duct and cholecystectomy, it was observed that the dogs became jaundiced but maintained serum bilirubin levels in a relatively low range (4 to 8 mg. per cent). Unlike the human with complete biliary obstruction, the dogs excreted their presumed daily production of bilirubin in the urine, thus accounting for the low serum levels.
Big data's impact on privacy, security and consumer welfare

The purpose of this paper is to highlight the costs, benefits, and externalities associated with organizations' use of big data. Specifically, it investigates how various inherent characteristics of big data are related to privacy, security and consumer welfare. The relation between characteristics of big data and privacy, security and consumer welfare issues are examined from the standpoints of data collection, storing, sharing and accessibility. The paper also discusses how privacy, security and welfare effects of big data are likely to vary across consumers of different levels of sophistication, vulnerability and technological savviness. There are various costs, benefits, and externalities associated with organizations' use of big data.Different characteristics of big data are tightly related to privacy, security and welfare effects.Privacy, security and welfare effects of big data are likely to vary across consumers of different levels of sophistication, vulnerability and technological savviness.
Comparison of the potential energies for various packings of microcrystallites

Abstract We compare the nature of different geometrical packings by presenting the dependence of the surface potential energy for microcrystallites of spherical atoms as a function of the cluster size, cluster packing and interaction range. Five polyhedron packings and the “approximately spherical” packing are studied. In general, the cubo-octahedron packings possess the minimum surface potential energy configuration.
Epitaxial Deposition of 3C-SiC on Si Using Unconventional Sputtering of a Hollow Cathode

Epitaxial 3C-SiC was grown using an unconventional technique for epitaxial growth. Thin films of 3C-SiC were deposited onto the (111) and (110) faces of Si using pulsed DC sputtering of a high purity, hollow cathode SiC target. The films were studied using x-ray diffraction (XRD), reflection high energy electron diffraction (RHEED), transmission electron microscopy (TEM), and auger electron spectroscopy (AES) techniques. XRD results presented as Bragg diffraction spectra and pole figures, and electron diffraction patterns verify crystal orientation and epitaxy. In addition, AES profiles identify the compositional integrity of the deposited films.
The consumer quest for authenticity: The multiplicity of meanings within the MG subculture of consumption

Authenticity in the consumption context is an important topic within the marketing literature. This article explores authenticity’s multiplicity of meanings within the MG brand subculture of consumption. An ethnographic approach guided data collection, which included participant observation, photo and document reviews, informal conversations, and formal, in-depth interviews with 58 MG owners. The data show that MG owners gain a sense of authenticity in the consumption context via the object and its ownership, consumer experiences, and identity construction and confirmation. As an object, an MG is authentic if it broaches an ideal standard and preserves the brand heritage. An MG experience is authentic when an owner interacts with the car through driving and self-work activities. Finally, an MG owner authenticates his or her identity through role performance and communal commitment. Implications are discussed in light of brand management.
Oxidative modifications to crystallins induced in calf lenses in vitro by hydrogen peroxide.

Calf lenses which are incubated in solutions of 1–150 m m H 2 O 2 for 24 hr remain clear at 20°C. While insoluble lens protein increases by at most 2–3%, we find extensive oxidation of exposed protein thiols, major shifts in the size distribution of crystallins and progressive generation of more acidic polypeptides. Some of these oxidative modifications are reversible with reducing agent. β H -Crystallins are particularly susceptible to oxidation: disulfide-bonded soluble aggregates form at low H 2 O 2 levels, while irreversible dissociation to β L -crystallins occurs at high H 2 O 2 concentration. The γ-crystallins are particularly prone to charge modification. In contrast, the size and charge distributions of α-crystallins appear to be virtually unaffected by H 2 O 2 .
Concurrent computing by sequential staging of tasks

Described is a new approach to parallel formulation of scientific problems on shared-memory multiprocessors such as the IBM ES/3090 system. The class of problems considered is characterized by repetitive operations applied over the computational domain D. In each such operation, some fields of interest are extrapolated or advanced by an amount of Δτ. The integration variable τ may be time, distance, or iteration sequence number, depending on the problem under consideration. An extensively studied approach to parallel formulation of such computational problems is based on domain decomposition, which attempts to partition the domain of integration into many pieces, then construct the global solution from these local solutions. Thus, domain decomposition methods are confined to D alone at a single τ level. An inquiry into the possibilities of formulating parallel tasks in τ, or more significantly in the D × τ domain, opens up new horizons and untapped opportunities. The aim of this paper is to detail an approach to exploit this τ domain parallelism that will be referred to as sequential staging of tasks (SST). Concurrency is realized by means of ordering the tasks sequentially and executing them in a partially overlapped or pipelined manner. The SST approach can yield remarkable speedup for jobs requiring intensive paging I/O, even when a single processor is available for executing multiple tasks. Noteworthy features of the SST method are demonstrated and highlighted by using results obtained from computer experiments performed with a numerical solution method of the Poisson equation and migration of seismic reflection data.
Sustained hypermetabolic sepsis in rats: characterization of the model.

This paper describes the development of a sustained sepsis model, using chronically catheterized conscious unrestrained rats, which simulates the progression of septicemia in man, including a sustained hypermetabolic phase. Following chronic arterial catheterization, sepsis was induced in rats by intraperitoneal administration of 0.5 ml of a pooled fecal inoculum. The pooled inoculum, which was used to ensure a uniform inoculation of microorganisms to all animals, produced a septicemia which was progressively lethal. The resultant peritonitis was characterized as polymicrobial, with gram-negative bacteria being continuously present in both peritoneal fluid and blood. Septic animals were normotensive but tachycardic, compared to time-matched controls, throughout the observation period. In contrast to the stable colonic temperature of control animals, septic rats showed a significant febrile response on the first 3 days following inoculation. The hypermetabolic response in septic rats was also manifested by a 25, 38, and 28% increase in oxygen consumption on Days 1, 2, and 3 postinoculation. Animals responded to sepsis with a fall in blood glucose (on Day 2) which remained 15–20% below control levels. Mild hyperlactacidemia (2 m M ) and reduced alanine concentrations (14–33%) were also seen in the septic group on Days 2 through 5. Despite the increased lactate levels, septic animals were mildly alkalotic (pH 7.51) which probably reflected the increased (32%) respiratory rate. Light microscopic findings in the septic animals revealed a sepctrum of morphologic lesions including an extensive fibrinopurulent exudate, bacterial colonies, and abscesses, which involved most of the abdominal viscera. This investigation characterizes an experimental model of sustained sepsis in rats which exhibits hemodynamic, metabolic and pathologic alterations similar to those seen in human peritonitis.
Structure and Function of Two Putative Virulence Factors from Francisella Tularensis

F. tularensis is a poorly understood category A priority pathogen and the etiological agent of Tularemia, or rabbit fever. Previous work by coworkers at LLNL identified seven putative virulence factor proteins, for which most have weak homology to proteins of known function. These seven proteins presumably are secreted host effector proteins, as they are important for inducing an encysted morphology in F. tularensis infected amoeba. Subsequent genetic studies have further implicated some of these ORFs as having a role in infection of human cells in culture. We have applied a structural-functional genomics approach in an attempt to elucidate the function of these rapid encystment proteins (REPs). Here we present the crystal structures of REP24 (24 kD) and REP34 (34 kD) and report on their putative function. REP24 appears to be a cysteine protease with a novel arrangement of the active-site catalytic triad, and we show that it binds to the cysteine protease inhibitor, JPM-565, both in vitro and in crystallo. REP34 By structural homology and, REP34 appears to be a Zn-dependent carboxypeptidase that possesses a novel fold that deviates from related funnelins, resulting in a rearranged active and substrate-recognition sites. We show the definitive presence of a Zn by anomalous diffraction, and catalytic activity of the enzyme using hippuryl-L-Arg. We believe that these structures provide potential starting points for rational design of new therapeutics against tularemia and, combined with further biochemical evidence, will provide important insights into the molecular mechanisms of F. tularensis infection.
Expanded coverage of the human heart mitochondrial proteome using multidimensional liquid chromatography coupled with tandem mass spectrometry.

Recent evidence suggests that mitochondria are closely linked with the aging process and degenerative disorders such as Alzheimer's disease and Parkinson's disease. Thus, there has been increasing interest in cataloging mitochondrial proteomes to identify potential diagnostic and therapeutic targets. We have previously reported results of a one-dimensional electrophoresis/liquid chromatography MS/MS study to characterize the proteome of normal human heart mitochondria (Taylor et al. Nat. Biotechnol. 2003, 21, 281−286). We now report two subsequent studies where multidimensional liquid chromatography MS/MS was investigated as an alternative means for characterizing the same sample. Keywords: mitochondria • LC/MS/MS • MudPIT • MDLC
High-performance parallel implementations of the NAS kernel benchmarks on the IBM SP2

Recently, researchers at NASA Ames have defined a set of computational benchmarks designed to measure the performance of parallel supercomputers. In this paper, we describe the parallel implementation of the five kernel benchmarks from this suite on the IBM SP2™, a scalable, distributed memory parallel computer. High-performance implementations of these kernels have been obtained by mapping the computation of these kernels to the underlying architecture of the SP2 machine. Performance results for the SP2 are compared with publicly available results for other high-performance computers.
Combining atomic force and fluorescence microscopy for analysis of quantum‐dot labeled protein–DNA complexes

Atomic force microscopy (AFM) and fluorescence microscopy are widely used for the study of protein-DNA interactions. While AFM excels in its ability to elucidate structural detail and spatial arrangement, it lacks the ability to distinguish between similarly sized objects in a complex system. This information is readily accessible to optical imaging techniques via site-specific fluorescent labels, which enable the direct detection and identification of multiple components simultaneously. Here, we show how the utilization of semiconductor quantum dots (QDs), serving as contrast agents for both AFM topography and fluorescence imaging, facilitates the combination of both imaging techniques, and with the addition of a flow based DNA extension method for sample deposition, results in a powerful tool for the study of protein-DNA complexes. We demonstrate the inherent advantages of this novel combination of techniques by imaging individual RNA polymerases (RNAP) on T7 genomic DNA.
Infectious implications in the porcine model of natural orifice transluminal endoscopic surgery (NOTES) with PEG-tube closure: a quantitative bacteriologic study.

Background Obtaining reliable closure of transvisceral defects currently limits natural orifice transluminal endoscopic surgery (NOTES). PEG tubes are potential means of managing NOTES gastrotomies. Objective To determine the efficacy of PEG closure after NOTES. Design An experimental animal study. Setting A laboratory. Interventions The pigs received gastric lavage with saline solution, chloramphenicol, or no lavage, and then underwent transgastric NOTES peritoneoscopy. Cultures were obtained by endoscopy during the surgery. A sterile foreign body was left in the peritoneal cavity. The gastrotomy was closed with a 20F PEG tube. The animals were observed for 14 days and underwent sterile laparotomy. Cultures of the foreign body and the peritoneal cavity were obtained. Main Outcome Measurements Abscess rate, peritoneal quantitative cultures. Results After 1 exclusion for anesthetic complications, 19 animals underwent NOTES; 18 (94.7%) survived the entire postoperative period. One animal died on postoperative day 2 after the PEG tube dislodged. At 14 days, 5 animals (27.8%) had intra-abdominal abscesses, 8 (44.4%) had positive peritoneal cultures, and 9 (50%) foreign bodies were contaminated on culture. Infectious complications were not altered by the type of gastric lavage or peritoneal bacterial inoculum introduced at the time of surgery. Limitation An animal model. Conclusions PEG closure of a NOTES gastrotomy is associated with subclinical intra-abdominal abscess formation and can result in death when the tube is dislodged during the early postoperative period. Preprocedural gastric lavage does not alter the intra-abdominal bacterial burden introduced at the time of surgery or subsequent infectious outcomes in the porcine model. These concerning findings necessitate additional studies to determine if porcine models are appropriate and applicable to human subjects in the NOTES setting.
Experimental study of the rheological properties of butadiene-styrene gum elastomers and compounds

Abstract The linear viscoelastic properties of a polybutadiene and three butadiene-styrene copolymers were determined using stress relaxation measurements. The Tobolsky-Murakami Procedure X was applied to the data to characterize a discrete relaxation spectrum. The nonlinear behavior was studied using transient shear stress buildup experiments. A single integral nonlinear constitutive equation was able to represent both the linear and nonlinear data if a Bogue-type relaxation time was used which involves a time-averaged second invariant of the rate of deformation matrix. The linear viscoelastic behavior is in essence represented by a single function G(t) (or the parameters Gm, τm, Gm−1, τm−1, Gm−2, τm−2, ⋯). Similar studies were carried out on a butadiene-styrene copolymer based tread and sidewall compounds but the shear stress transient data were incompatible with the stress relaxation results. The reasons for this are discussed.
Theory of Ionization Probability Near Threshold

The behavior of the cross section for ionization by electron impact is investigated in the vicinity of threshold by means of the quantum theory of inelastic scattering. A Coulomb-modified form of the Born approximation is used to calculate the $S$-wave ionization cross sections for ${\mathrm{H}}^{+}$, ${\mathrm{He}}^{+}$, and ${\mathrm{He}}^{++}$. The electron-nuclear interaction is included in the unperturbed Hamiltonian for the problem while the interaction between the incident and atomic electrons is considered as the perturbation. It can be shown that the limiting law for the ionization of a hydrogen atom has a linear dependence on the excess incident energy. The absolute cross sections evaluated are in good agreement with experiment. Generalization of the excess energy dependence of the threshold law to the case of multiple ($n$-fold) ionization is found to yield the forms ${{E}_{\mathrm{ex}}}^{n}$ for ionization by electron impact and ${{E}_{\mathrm{ex}}}^{n\ensuremath{-}1}$ for photoionization.
TH‐SAMS‐AUD B‐05: Image Guided Radiation Therapy

Paralleling the introduction of Intensity Modulated Radiation Therapy(IMRT) in the early to mid 1990s, Image Guided Radiation Therapy(IGRT) is an important but problematic new tool for the RadiationOncology community. The challenges are similar to IMRT in that IGRT is a general classification that covers many different approaches with numerous variations. Where IMRT ranges from tomotherapy to conventional MLC‐based dose delivery with many different treatment planning approaches, IGRT covers a broad spectrum of techniques ranging from stereoscopic x‐ray imaging with rigid‐body registration to cone‐beam volume imaging with deformable fusion. Thus, like IMRT, guaranteeing the safe and effective use of this new modality in a clinical trial setting will require procedures that are as comprehensive as the ones currently in place for IMRT. As quality assurance techniques are developed for routine clinical use of advanced technologies like IGRT, they must also be appropriately standardized for use in clinical trials. Image Guidance is defined for RTOG protocols as the steps of obtaining daily in‐room images of the patient in the treatment position, matching or fusing these images to the ones obtained during the treatment planning process, and the procedure of manually or automatically changing the patient's position based on the fusioninformation. Notice that this description does not consider the patient as a deformable object. Using this simple definition, a number of Radiation Therapy Oncology Group (RTOG) protocols have employed or are including IGRT for targeting the lesion. These protocols require institutions to verify their IGRT methodology through a credentialing process. This process is aimed at guaranteeing that each institution understands the protocol requirements relative to the use of their fusion software or manual shift capabilities. This presentation will discuss the process used by the RTOG to credential institutions for the use of IGRT in their protocols, and it will present the problems and considerations that will have to be addressed as the above definition of IGRT expands to include moving targets and deformable fusion.
A finite-dimensional quark model

A description of quarks is given in terms of a finite-dimensional Hilbert space model. Color and flavor observables are defined and the corresponding motion and energy observables are constructed using the methods of finite-dimensional quantum mechanics. It is shown that a fundamental color condition implies that quarks can only combine as mesons, baryons, antibaryons, and collections of these. Baryon and meson Hamiltonians are proposed and various masses are computed.
On the dispersion measure of high-redshift synchrotron sources

A method is proposed for deriving the dispersion measure (related to the line-of-sight integrated free electron density) to high-redshift, powerful synchrotron radio sources by analysis of the temporal/spectral properties of the recorded signals. This would allow direct measurements of the distributed density of ionized baryons along the line-of-sights to the sources.
An economic order quantity model for items experiencing failure in storage

In this paper, an economic order quantity model for items which experience failure according to a probabilistic rate during the storage period is developed. Prior research on item failure has primarily focused on items which can be repaired or sold at a discount. Scenarios that assume repair and discounted sales, however, are impractical for systems where repair costs exceed or are equivalent to item costs and imperfect items are unacceptable. Such cases are prevalent in the medical and electronics industries where defective items are largely unusable. The model presented in this paper is applicable to systems with large fixed order costs and lengthy inventory holding periods. The paper first develops an economic order quantity model for the presented framework. Illustrative numerical examples which demonstrate the effects of certain model parameter changes on optimal order quantity and firm profitability are then provided.
Impedance monitoring during catheter ablation of atrial fibrillation.

Background Delivery of radiofrequency energy in proximity of a pulmonary vein can cause vein stenosis. A sudden decrease in impedance as the catheter is moved from the vein into the left atrium (LA) has been used to define the pulmonary vein-LA transition during ablation procedures. Objectives The purpose of this study was to define the variables affecting impedance measurement. Methods In vitro analysis of impedance was performed in a saline bath using sheaths and a plastic stereolithographic model of the LA. Impedance was continuously monitored during a calibrated pullback from the pulmonary vein into the LA in 37 veins of 10 patients referred for catheter ablation. Location of the catheter was confirmed by the following imaging modalities: intracardiac echocardiography, contrast venography, electroanatomic mapping, and computed tomography/magnetic resonance imaging (offline) in all patients. Results Larger cross-sectional areas containing the catheter correlated with lower impedance in an exponential manner both with respect to sheath size (R 2 = 0.99) and in the stereolithographic model (R 2 = 0.91). In vivo , the impedance in the pulmonary veins decreased in an exponential manner as the catheter was pulled back into the LA. However, impedance at the vein orifice was not significantly higher than the LA. A defined cutoff value for defining the pulmonary vein-LA transition could not be identified. Conclusion The primary determinant of impedance is the cross-sectional area of the space containing the catheter. Impedance monitoring alone does not guarantee a catheter tip position outside the pulmonary vein. Intraprocedural imaging confirmation should be considered to avoid radiofrequency application within pulmonary veins.
On-Line Fourier Transform Infrared Analysis of Pyrolysis and Combustion Products

Thermal degradation studies conducted on a wide variety of polymeric materials necessitate sensitive and informative analytical techniques. Studies of thermal degradation under carefully controlled pyrolytic (inert) and combustive (air) conditions have been reported in which the major volatile products were monitored by gas chromatography (gc). With the use of data obtained by this method, details in polymer microstructure and degradation mechanisms have been deduced. We now report the results from a preliminary series of such controlled degradation conditions with on-line monitoring of the volatile products by automatic gc analysis and Fourier transform infrared (FT-ir) spectroscopy.
An Evolution in the Management of Sinonasal Inverting Papilloma

Objective: We reviewed the 15-year experience of our institution (Medical College of Wisconsin, Milwaukee, WI) in managing sinonasal inverting papilloma, examining trends in diagnosis and treatment. Study Design: Retrospective. Methods: Thirty-seven patients with inverting papilloma were treated from 1986 to 1999. Demographic data, clinical presentations, pathological findings, surgical approaches and procedures, and recurrence rates were collected retrospectively. Each lesion was categorized into one of four groups based on computed tomography scans and endoscopic findings. This categorization was developed to compare various surgical approaches for tumors in each group. Results: Thirty-one patients had complete information for inclusion in our study. Nineteen patients were treated endoscopically with an average follow-up of 50 months. Eight patients were in group I, five were in group II, six were in group III, and no patients were in group IV. The recurrence rate for the endoscopic group was 10%. Twelve patients underwent lateral rhinotomy or sublabial degloving approach with an average follow-up of 58 months. Five patients were in group I, three patients were in group II, 1 patient was in group III, and three patients were in group IV. The recurrence rate for the external group was 8%. Difference in recurrence rates (p = .85) was not observed between the endoscopic and external approach groups. Regardless of approach, patients who had primary resection had a recurrence of 0%, whereas those with secondary resection had a recurrence of 17% (p = .10). Conclusions: Technological advancements have led to a trend of detecting sinonasal inverting papilloma before extension beyond the sinonasal region. Difference in recurrence rates was not observed between the endoscopic and the external approach groups. Recurrence rates are lower for primary resection versus secondary resection, regardless of surgical approach.
Controlled preparation and detection of d-wave superfluidity in two-dimensional optical superlattices

d-wave Cooper pairs are believed to be the key for understanding the phenomenon of high-temperature superconductivity in cuprates. These superconductors are an example of the emergence of strong pairing in systems with purely repulsive interactions, similar to superfluid helium 3 and the newly discovered iron oxypnictides. Despite intense studies, there is currently no consensus as to what causes the formation of d-wave Cooper pairs in these materials. Here we propose a novel experimental scheme in which recently demonstrated methods for realizing optical lattices and superlattices are combined to create and to detect, in a controlled way, ultracold-atom d-wave Cooper pairs. Our scheme starts from arrays of isolated plaquettes which incorporate the required d-wave correlations on a short length scale. By tuning the parameters of the potentials, these plaquettes can be coupled to achieve long-range d-wave superfluid correlations, finally arriving at the generic Hubbard model.
Atm deficiency results in severe meiotic disruption as early as leptonema of prophase I

Infertility is a common feature of the human disorder ataxia-telangiectasia and Atm-deficient mice are completely infertile. To gain further insight into the role of ATM in meiosis, we examined meiotic cells in Atm-deficient mice during development. Spermatocyte degeneration begins between postnatal days 8 and 16.5, soon after entry into prophase I of meiosis, while oocytes degenerate late in embryogenesis prior to dictyate arrest. Using electron microscopy and immunolocalization of meiotic proteins in mutant adult spermatocytes, we found that male and female gametogenesis is severely disrupted in Atm-deficient mice as early as leptonema of prophase I, resulting in apoptotic degeneration. A small number of mutant cells progress into later stages of meiosis, but no cells proceed beyond prophase I. ATR, a protein related to ATM, DMC1, a RAD51 family member, and RAD51 are mislocalized to chromatin and have reduced localization to developing synaptonemal complexes in spermatocytes from Atm-deficient mice, suggesting dysregulation of the orderly progression of meiotic events. ATM protein is normally present at high levels primarily in ova cytoplasm of developing ovarian follicles, and in the nucleus of spermatogonia and to a lesser extent in spermatoctyes, but without localization to the synaptonemal complex. We propose a model in which ATM acts to monitor meiosis by participation in the regulation or surveillance of meiotic progression, similar to its role as a monitor of mitotic cell cycle progression.
The Effects of Rhetorical Organization on ESL Readers.

Theoretical as well as empirical research within the framework of schema-theoretical approaches to reading has shown reading comprehension to be an interaction between a text and a reader. More specifically, the interaction involves reader background knowledge of text structure and the hierarchical content structure of the text. In her investigations of both adult and adolescent native readers of English, Meyer (1975, 1977a, 1977b, 1979, 1982; Meyer, Brandt, and Bluth 1980; Meyer and Freedle 1984) has found that certain types of rhetorical organization of expository prose are processed and recalled differently from other types. This article reports the results of a study of the effects of rhetorical organization of different types of expository prose on intermediate ESL readers of different native languages. Results indicate that certain more highly structured English rhetorical patterns are more facilitative of recall for non-native readers in general, but there are interesting differences among the native language groups represented in the study: Spanish, Arabic, and Oriental.