cssi/SciSciGPT-SciSciNet huggingface dataset:
The inversion of acoustical impedance profile by methods of characteristics

Abstract The inverse problem for the one-dimensional propagation of waves through a medium with an unknown impedance profile is considered. From the reflected pulses caused by an excitation of short duration, this profile is reconstructed by applying the method of characteristics with finite difference approximations. This leads to a simple and fast algorithm, which is demonstrated by the numerical examples in the paper.
Vincristine-Induced Megacolon

Three cases of vincristine-induced megacolon are described with radiographic correlation. Vincristine is a widely used chemotherapeutic agent with neuropathic side effects causing colonic dilatation and constipation. The radiologist should be aware of this entity to prevent unnecessary procedures and, possibly, surgery.
Three-dimensional natural convection in a high-pressure mercury discharge lamp

A three-dimensional computer model is used to calculate the convective flow in a 400 W high-pressure Hg discharge lamp. The model gives the expected axisymmetric flow when the arc tube axis is vertical, and more complex three-dimensional flows when it is not.
Influence of left atrial systolic emptying on left ventricular early filling dynamics by Doppler in patients with sequential atrioventricular pacemakers.

Abstract Pulsed Doppler echocardiography has been established as an accurate technique for measuring mitral inflow velocity from which peak filling rate and other related parameters of left ventricular (LV) filling can be easily derived. 1–3 Several Doppler studies have recently shown that these parameters of diastolic function are dependent on a host of factors such as heart rate, age, LV relaxation and compliance, ratio of LV radius to wall thickness and left atrial (LA) pressure. 4–8 Ishida et al 7 have demonstrated that the instantaneous pressure gradient between left atrium and left ventricle at the time of peak mitral inflow has a direct influence on peak mitral flow and consequently filling rate. Since the height of the V wave in the left atrium depends on the completeness of atrial emptying during diastole, it is conceivable that the effectiveness of atrial contraction could have an influence on early peak mitral flow. The present investigation was designed using a population of patients with programmable atrioventricular (AV) sequential pacemakers as a model to examine the relation between the effectiveness of LA contraction induced by changing the sequence of LV contraction and peak mitral flow velocity and filling rate by Doppler.
Non-planar shear flows for non-aligning nematic liquid crystals

Abstract We investigate the stability of simple planar shear flow between moving parallel plates for non-aligning nematic liquid crystals. We present numeri- cal results for the continuation of the non-planar solution branch from its bifurcation from the planar solution branch which agree with the experi- mental results of Pieranski and Guyon that at a critical shear rate the director turns out of the shear plane to an orientation nearly orthogonal to the shear plane.
Primary central nervous system lymphoma related to Epstein‐Barr virus in a patient with acquired immune deficiency syndrome

The study of a patient suggested a relationship between Epstein-Barr virus infection and primary lymphoma of the central nervous system in the acquired immune deficiency syndrome. Deoxyribonucleic acid preparations from tumor tissue contained 30 to 100 copies of Epstein-Barr virus genome per cell when hybridized with a probe consisting of the Bam-HI K fragment of Epstein-Barr virus strain FF41. This hybridization study suggests that induction of this patient's central nervous system lymphoma was related to Epstein-Barr virus infection.
Iridium-Promoted Reactions of Carbon−Carbon Bonds. Skeletal Rearrangement of a Vinylcyclopropene during Iridacyclohexadiene Formation and Subsequent Isomerization of Iridacyclohexadienes via α,α‘-Substituent Migrations

On treatment with [Ir(PMe3)2(acac)] at room temperature, 1,2,3-triphenyl-3-vinylcyclopropene undergoes ring opening accompanied by rearrangement to give, instead of the expected 1,2,3-triphenyliridacyclohexadiene complex, a crystallographically characterized 1,2,4-triphenyliridacyclohexadiene complex containing cis-phosphine ligands. Studies with 2H- and doubly 13C-labeled vinylcyclopropenes, the syntheses and characterization of which are also reported, show that this process involves a rearrangement of the carbon skeleton and not a substituent shift. The corresponding 1,2-diphenyl-3-vinylcyclopropene undergoes iridacyclohexadiene formation without any rearrangement. On heating at 90 °C, each iridacycle converts to its corresponding isomer containing trans-phosphine ligands without any skeletal or substituent rearrangement of the metallacycle, as evidenced by absence of change in the labeling pattern. At higher temperatures, further rearrangement occurs in the case of each metallacycle, which does not al...
What Types Of Standards Would Be Useful In PACS Activities

Digital storage and retrival of diagnostic image information in a large medical center is dependent upon the interconnection and successful use of many types of electronic equipment. Much of this equipment may be sufficiently dissimilar to cause major interconnection problems. For these individual systems to function together in a picture archiving and communication system (PACS) network it is essential that of their use and operation be coordinated in a systematic manner according to standardized procedures. There are several benefits to the adoption and use of such standards: a) New equipment and software can be designed for parts of the system without the entire system becomming obsolete. b) Permanence of the archived image material will be unaffected by replacement of archive equipment. c) Communication of image data between medical centers will be simpler. This talk will outline desirable characteristics for standards designed to help meet these objectives. Aspects of archive system operation that are suitable for standardization will be discussed and contrasted with those most likely best left unspecified to encourage creative diversity.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
‘Pour the sweet milk of concord into hell’: Theories of Unity and Disunity in Late Beethoven

Evidently disenchanted with the vein of criticism that typically greeted his music, Beethoven wrote to the music publisher Adolf Martin Schlesinger in July 1825 congratulating him on his choice of Adolph Bernhard Marx as editor-inchief of the recently-founded Berliner allgemeine musikalische Zeitung. In so doing he voiced the hope that Marx would 'continue to reveal more and more what is noble and true in the sphere of art', a process the composer of the recently-completed Ninth Symphony saw as involving infinitely more than 'the mere counting of syllables'. 1 Fifteen years earlier, as Bettina Brentano wrote to Goethe, the composer expressed a similar viewpoint when he reportedly said that 'Music, verily, is the mediator between the life of the mind and the senses', the 'one incorporeal entrance into the higher world of knowledge ... the electrical soil in which the mind thinks, lives, feels'.2 After an extended hiatus during which questions of musical meaning were viewed with scepticism if not out-and-out disdain, the position ostensibly endorsed by I3eethoven is again enjoying favour. Indeed, the last two decades or so have brought with them an incredible transformation of what it means to engage in musical reflection. With the seeming force of continental plates colliding head-on, modes of understanding have shifted to the point where in a great many quarters at leastit is no longer deemed sufficient to treat music as if it were a science whose substance is to be laid bare beneath a microscope, an isolated phenomenon where meaning is be ascertained solely within the notes. Nowadays, cultural context, gender, genre, hermeneutics and narrativity are among the near-myriad number of interdisciplinary perspectives which have found their way into a field formerly predicated on the empirically objective. As Rose Rosengard Subotnik put it almost a decade ago, 'emotion and meaning are coming out of the musicological closet'.3 Looking back on all of these dazzling, sometimes dizzying developments, it is worth noting that Beethoven studies have almost always led the way in explorations of new critical methods; indeed, just about every analytical system from the nineteenth century to the present day has been inspired in some way by this composer. Focusing particularly on the composer's 'middle period', critics as diverse as Hoffmann, Schumann, Hanslick, Wagner, Riemann, Schenker and
Anatomical and morphometric variations in the arterial system of the domestic cat.

Summary We document the anatomical architecture and frequency of occurrence of variations in the branching pattern of the brachiocephalic artery and the origin of the internal iliac arteries in the domestic cat, a widely used model organism in both anatomical training and research. Based on the study of 56 preserved specimens, we observed three distinct arrangements in the branching pattern of the brachiocephalic artery. The most common pattern (52% of the examined specimens) was that in which the brachiocephalic artery was divided into two branches, the left common carotid artery and a common branch for the right subclavian artery and the right common carotid artery. The frequency of occurrence of each variation type was independent of the gender and body size. The internal iliac arteries originated caudal to the point at which the external iliac arteries branched off from the abdominal aorta. However, the portion of the abdominal aorta between the external and internal iliac arteries varied greatly in length and was not significantly correlated with its width, nor with body size or gender. This study is the first to report and quantify the occurrence of such variations in North American cats. Given the anatomical similarity between the cat and other felids, the results of this study can be applied to other species, including endangered species.
The Tax Compliance Puzzle: Evidence from Theory and Practice

Abstract What lawmakers, administrators, and researchers do not know about tax compliance erodes the foundation of government finances by threatening the equity, efficiency, effectiveness, and yield of the tax system. Modern tax systems rely heavily on voluntary compliance for revenue collection. Unfortunately, tax administrators and researchers have only a limited understanding of why people pay taxes and how much tax liability is uncollected, even though this information is critical for measuring administrative performance and for targeting compliance strategies. This article examines evidence on taxpayer compliance, both domestic and international, to provide a synthesis of what is understood about compliance, how administrators and lawmakers may best collect the taxes that have been levied, and how administrators and researchers may measure noncompliance and the effectiveness of approaches toward its reduction.
Resistance of teratocarcinoma stem cells to infection with simian virus 40: early events.

Multipotential stem cells of a murine teratocarcinoma are resistant to typical infection with either polyoma virus (PV) or Simian virus 40 (SV40). Differentiated progeny of the stem cells are susceptible to infection in a manner identical to other mouse somatic cells, i.e., they are permissive for PV and nonpermissive for SV40. The early interactions between the stem cells (embryonal carcinoma or EC cells) and SV40 and PV were studied. Virions adsorbed to and penetrated into the cytoplasm and nucleus of EC cells, but did not induce expression of T antigen in the EC nuclei. Purified SV40 DNA was capable of inducing T antigen in differentiated teratocarcinoma cells but not in EC cells. Virus could not be rescued from EC cells previously exposed to SV40. The resistance of the stem cells to infection apparently involves a block in the infectious cycle after adsorption and penetration but before T antigen induction.
Taxing agricultural land in developing countries

Agriculture is the largest economic sector in most countries of Latin American, Africa, and Asia, and the taxation of agricultural land is a potentially important instrument in the development policies of such nations. But there is a large gap between theory and practice, a gap that needs explaining. In addition, there have been interesting changes in thought on the role of such taxation in development. Richard M. Bird covers all this in a complete rethinking of the whole subject. His book is a distinguished successor to Haskell P. Wald s classic study, "Taxation of Agricultural Land in Underdeveloped Economics," published by Harvard University Press in 1959. With abundant evidence Bird argues that the tax system of each country, in order to be effective as a part of development policy, must be tailored carefully to peculiar circumstances and objectives of that country."
Differential behavioral effects of nicotine exposure in adolescent and adult rats

Rationale Although the detrimental effects of nicotine in early brain development and the addictive properties in adulthood are well known, little is known about the neurobiological effects of nicotine in adolescence. An important question is whether adolescents and adults differ in the development of nicotine sensitization and drug-cue conditioning.
Cell adaptation to a physiologically relevant ECM mimic with different viscoelastic properties

To successfully induce tissue repair or regeneration in vivo, bioengineered constructs must possess both optimal bioactivity and mechanical strength. This is because cell interaction with the extracellular matrix (ECM) produces two different but concurrent signaling mechanisms: ligation-induced signaling, which depends on ECM biological stimuli, and traction-induced signaling, which depends on ECM mechanical stimuli. In this report, we provide a fundamental understanding of how alterations in mechanical stimuli alone, produced by varying the viscoelastic properties of our bioengineered construct, modulate phenotypic behavior at the whole-cell level. Using a physiologically relevant ECM mimic composed of hyaluronan and fibronectin, we found that adult human dermal fibroblasts modify their mechanical response in order to match substrate stiffness. More specifically, the cells on stiffer substrates had higher modulus and a more stretched and organized actin cytoskeleton (and vice versa), which translated into larger traction forces exerted on the substrate. This modulation of cellular mechanics had contrasting effects on migration and proliferation, where cells migrated faster on softer substrates while proliferating preferentially on the stiffer ones. These findings implicate substrate rigidity as a critical design parameter in the development of bioengineered constructs aimed at eliciting maximal cell and tissue function.
Suppression of apoptosis in a cytotoxic T-cell line by interleukin 2-mediated gene transcription and deregulated expression of the protooncogene bcl-2

Absence of interleukin 2 (IL-2) from IL-2-dependent cells, such as the cytotoxic T-cell line CTLL2, causes DNA fragmentation and programmed cell death (apoptosis). We found that, upon initiation, DNA degradation proceeds rapidly. IL-2-deprived CTLL2 cells can be rescued from apoptosis by the addition of IL-2 2 h prior to the onset of detectable DNA breakdown. Addition of inhibitors of transcription with IL-2 abolished the IL-2-mediated rescue of CTLL2 cells. Thus it appears that IL-2-mediated gene transcription is necessary for survival. Deregulated expression of a protooncogene, bcl-2, inhibits apoptosis of cells dependent on other hematopoietic growth factors. To determine whether bcl-2 was active in CTLL2 cells, we transfected CTLL2 cells with a plasmid containing bcl-2 cDNA expressed under the metallothionein promoter and observed prolonged survival of the transfected cells upon IL-2 deprivation. Cell growth, however, was arrested in the G0/G1 or G2/M phases of the cell cycle. The prolonged survival of bcl-2 transfectants allowed the analysis of endogenous bcl-2 mRNA levels by Northern blot analysis. The expression of endogenous bcl-2 was down-regulated within 8 h of IL-2 withdrawal and was not detected after 3 days. Addition of IL-2 induced endogenous bcl-2 expression within 8 h. Full recovery of bcl-2 expression was achieved by 24 h after IL-2 addition. We conclude that the survival of death-prone CTLL2 cells may be viewed as IL-2-dependent suppression of suicide, probably by the IL-2-induced expression of the cellular bcl-2 gene.
Low-background germanium spectrometry: The bottom line

A summary of sources of background affecting gamma-ray spectrometers and methods for eliminating each are discussed, along with practical cost/benefit ratios. Background contributed by samples generally defines practical levels for system background. The practical bottom line can be obtained for relatively modest costs. A realistic bottom line is attained in underground systems when the major contributions to the background come from cosmogenically produced68Ge and double-beta decay of76Ge in the detector. The true bottom line is reached with isotopically enriched detectors that eliminate these two chemically inseparable radioactive impurities. Data from isotopically enriched detectors are presented.
Surface-modified poly(methyl methacrylate) capillary electrophoresis microchips for protein and peptide analysis.

Polymeric materials have emerged as appealing alternatives to conventional inorganic substrates for the fabrication of microscale analytical systems; however, native polymeric surfaces typically require covalent modification to ensure optimum biocompatibility. 2-Bromoisobutyryl bromide was immobilized on poly(methyl methacrylate) (PMMA) substrates activated using an oxygen plasma. Atom-transfer radical polymerization was then performed to graft poly(ethylene glycol) (PEG) on the PMMA surface. PMMA microcapillary electrophoresis (μCE) devices made with the covalently modified surfaces exhibited substantially reduced electroosmotic flow and nonspecific adsorption of proteins on microchannel surfaces. Experiments using fluorescein isothiocyanate-conjugated bovine serum albumin indicated that both column efficiency and migration time reproducibility were 1 order of magnitude better with derivatized compared to untreated PMMA μCE chips. Fast, reproducible, and efficient separations of proteins and peptides wer...
ERP II: best practices for successfully implementing an ERP upgrade

An ERP upgrade is deceptively complex and can be daunting---especially for organizations ignorant of the massive effort required to do it correctly.
Properties of Rubber-Modified Polypropylene Impact Blends

Blends of polypropylene (PP) with epoxidised natural rubber (ENR-50) and constant-viscosity natural rubber (SMR-CV) were prepared in a laboratory-scale extruder; the rubber content ranged from 0 to 50%. The mix ing torques increase as the percentage of rubber increases-an indication of in crease in the melt viscosity. After mixing and pelletising, the samples were in jection moulded and tested for mechanical properties. Tensile strength decreases while elongation at break increases as the rubber content in the blends increases. PP/ENR-50 blends show an increase in die swell while PP/SMR-CV blends show a decrease with increasing rubber content. PP/ SMR-CV blends have higher Izod impact strength than PP/ENR-50 blends. Dynamic mechanical analysis (DMA) was used for the compatibility studies and the PP/ENR-50 blends were observed to be more compatible than the PP/SMR-CV blends. The "stable torque" from mixing studies further corrobo rates the compatibility study. Differential scanning calorimetry (DSC) analys...
Mechanism Design: Enumeration of Kinematic Structures According to Function

INTRODUCTION A Systematic Design Methodology Links and Joints Kinematic Chains, Mechanisms, and Machines Kinematics of Mechanisms Planar, Spherical, and Spatial Mechanisms Kinematic Inversions BASIC CONCEPT OF GRAPH THEORY Definitions Tree Planar Graph Spanning Trees and Fundamental Circuits Euler's Equation Topological Characteristics of Planar Graphs Matrix Representation of Graphs Contracted Graphs Dual Graphs STRUCTURAL REPRESENTATIONS OF MECHANISMS Functional Schematic Representation Structural Representation Graph Representation Matrix Representation STRUCTURAL ANALYSIS OF MECHANISMS Correspondence between Mechanisms and Graphs Degrees of Freedom Loop Mobility Criterion Lower and Upper Bounds on the Number of Joints on a Link Link Assortments Partition of Binary Link Chains Structural Isomorphism Permutation Group and Group of Automorphisms Identification of Structural Isomorphism Partially Locked Kinematic Chains ENUMERATION OF GRAPHS OF KINEMATIC CHAINS Enumeration of Contracted Graphs Enumeration of Conventional Graphs Atlas of Graphs of Kinematic Chains CLASSIFICATION OF MECHANISMS Planar Mechanisms Spherical Mechanisms Spatial Mechanisms EPICYCLIC GEAR TRAINS Structural Characteristics Buchsbaum-Freudenstein Method Genetic Graph Approach Parent Bar Linkage Method Mechanism Pseudo Isomorphisms Atlas of Epicyclic Gear Trains Kinematics of Epicyclic Gear Trains AUTOMOTIVE MECHANISMS Variable-Stroke Engine Mechanisms Constant-Velocity Shaft Couplings Automatic Transmission Mechanisms Canonical Graph Representation of EGMs Atlas of Epicyclic Gear Transmission Mechanisms ROBOTIC MECHANISMS Parallel Manipulators Robotic Wrist Mechanisms APPENDICES: A. Solving m Equations in n unknowns B. Atlas of Contracted Graphs C. Atlas of Graphs of Kinematic Chains D. Atlas of Planar Bar Linkages E. Atlas of Spatial One-dof Kinematic Chains F. Atlas of Epicyclic Gear Trains G. Atlas of Epicyclic Gear Transmission Mechanisms NOTE: Introduction at the beginning of Chapters 1,3-9 Summary at the end of Chapters 1-6,8-9
Analysis of neighborhood competition among annual plants: implications of a plant growth model

Abstract Regression analyses between individual plant growth and indices of local crowding are a popular means to examine the effects of spatially-explicit competition. Low correlations between performance and local crowding are thought to reflect the importance of non-competitive factors in determining plant size. Simulation analyses using an individual-plant, spatially-explicit model of population dynamics suggest that this conclusion is not universally valid. Individual plant growth was prescribed as a function of a growth rate coefficient, growing space, and mass. Regression analysis recovered the known linear relationship between growth and growing space when growth rate coefficients were constant for all plants, but recovered a curvilinear relationship when growth rate coefficients varied randomly among plants. When growing space was approximated by a relative competition index, random variation in growth rate coefficients caused a triangular envelope relationship between growth and neighborhood competition in which there was much variability in growth rates when plants grew without neighbors and little variability in growth rates when plants lost resources to neighbors. The sessile nature of plants ensures that spatially-explicit competition can be important. More attention needs to be given to experiments that document this rather than correlative analyses at a given point in time.
Clustering in Dilute Binary Supercritical Mixtures : a Fluctuation Analysis

Abstract Solute-solvent concentration fluctuation correlations at infinite dilution are a statistical measure of the excess number of solvent molecules surrounding a given solute molecule, with respect to a uniform distribution at the prevailing density. This leads to the concept of a cluster which, in dilute supercritical mixtures (trace solute(s) in the vicinity of a solvent's critical point) acquires mechanistic and not merely statistical significance. Experimental measurements of solute partial molar volumes at infinite dilution in such systems are shown to be equivalent, when analyzed in the light of fluctuation theory, to a cluster size determination. This quantity can be either positive or negative. Calculations based on experimental measurements of infinite dilution partial molar volumes of organic solids in supercritical fluids indicate the existence of clusters of ca 100 solvent molecules per solute molecule. The fluctuation approach cannot be used arbitrarily close to the solvent's critical point, since it is based on the assumption of a finite solvent compressibility. Asymptotic laws for the behavior of solute fluctuations in dilute mixtures within differently defined regions of space (constant volume; constant solvent mass) are derived. Finally, it is shown that there is a univocal relationship between cluster formation and the experimentally observed solubility enhancement in dilute mixtures of non-volatile solutes in supercritical solvents.
Microtubule Organization in the Cow during Fertilization, Polyspermy, Parthenogenesis, and Nuclear Transfer: The Role of the Sperm Aster

Microtubule organization in bovine oocytes during fertilization, polyspermy, parthenogenesis, and nuclear transfer is examined with the goal of understanding microtubule activity and the manner in which the centrosome during fertilization and mitotic spindle poles are established. In the unfertilized bovine oocyte, microtubules are detected only in the metaphase-arrested second meiotic spindle; no cytoplasmic asters are observed. After insemination, a small aster of microtubules is seen adjacent to the incorporated sperm head. This aster enlarges and, at the time of pronuclear apposition, fills the cytoplasm. At prophase, the aster splits and forms the poles for the first mitotic spindle, which is anastral, fusiform, and often located eccentrically. During anaphase, asters assemble at each spindle pole. After telophase, these asters develop into the interphase array of microtubules in the daughter blastomeres. During polyspermy, an aster forms from a site between each incorporated sperm head and tail. Multiple mitotic spindles are observed in polyspermic zygotes; multipolar spindles are not seen. Parthenogenetic activation with 5 microns ionomycin followed by a 4-hr incubation in 1.9 mM dimethylaminopurine results in > 80% activation, and antitubulin immunofluorescence microscopy demonstrates that initially disarrayed microtubules are observed and the some microtubules extend from the remnants of the second meiotic spindle. At the time normal for cell division, these parthenogenotes form anastral, barrel-shaped bipolar mitotic spindles. Asters form at the spindle poles at anaphase and the parthenogenotes divide from one to two blastomeres. Nuclear fusion of a morula-derived blastomere to a parthenogenetically activated oocyte results in either a single microtubule aster or at times, two asters, formed in association with the donated nucleus. These results demonstrate that fertilization in the cow is a blending of paternally and maternally derived centrosomal material.
The Role of the PSA in Graduate Student Training and Professional Development

Attending and presenting at academic conferences can be an unnerving and formidable experience, especially for graduate students. In this essay, I describe some of my experiences as a graduate student, highlighting the benefits of attending and presenting at the Pacific Sociological Association annual conference and how this aided my professional development. I also provide some ideas for the Association to consider in their goal of improving the graduate student experience. Finally, I conclude with some recommendations for current graduate students attending the regional conference.
Selective removal of magnetization in coupled NMR spectra

Two methods, based on the phase modulation of spin-echo signals due to J-coupling, of selective simplification of coupled homonuclear spectra are described. Both pulse methods employ a 90 Deg-t-180 Deg-t spin-echo sequence to prep. suitable phases of the magnetization in the rotating frame. For t = (4J)-1, all doublet magnetization vectors have opposite phases, parallel to the phase of the initial pulse. The 1st method uses a single 45 Deg pulse, with a phase F alternating between +y and -y and addn. of the decaying half-echoes, to remove doublet magnetization without affecting singlets. The 2nd method employs a pulse sandwich 90 Degf -90 Degx to generate and recall double-quantum coherence. Singlets are suppressed by cycling the phase F through x,y,-x, and -y, while adding and subtracting alternate transients. [on SciFinder (R)]
Intrinsic brain activity triggers trigeminal meningeal afferents in a migraine model

Although the trigeminal nerve innervates the meninges and participates in the genesis of migraine headaches, triggering mechanisms remain controversial and poorly understood. Here we establish a link between migraine aura and headache by demonstrating that cortical spreading depression, implicated in migraine visual aura, activates trigeminovascular afferents and evokes a series of cortical meningeal and brainstem events consistent with the development of headache. Cortical spreading depression caused long-lasting blood-flow enhancement selectively within the middle meningeal artery dependent upon trigeminal and parasympathetic activation, and plasma protein leakage within the dura mater in part by a neurokinin-1-receptor mechanism. Our findings provide a neural mechanism by which extracerebral cephalic blood flow couples to brain events; this mechanism explains vasodilation during headache and links intense neurometabolic brain activity with the transmission of headache pain by the trigeminal nerve.
Categorical abstract algebraic logic categorical algebraization of first-order logic without terms

An algebraization of multi-signature first-order logic without terms is presented. Rather than following the traditional method of choosing a type of algebras and constructing an appropriate variety, as is done in the case of cylindric and polyadic algebras, a new categorical algebraization method is used: The substitutions of formulas of one signature for relation symbols in another are treated in the object language. This enables the automatic generation via an adjunction of an algebraic theory. The algebras of this theory are then used to algebraize first-order logic.
Gluconeogenesis in rat liver cytosol. II. Computer simulation of control properties

Abstract The effect of changes in the adenine nucleotide, pyridine nucleotide, and cytoplasmic citrate concentrations on the rate of gluconeogenesis in perfused rat livers has been evaluated using digital computer models of this pathway. Varying the concentrations of nucleotides or citrate produced pseudocrossovers at enzymes acting between phosphoenolpyruvate and glucose-6-phosphate. However, unless the influx of phosphoenolpyruvate was also appropriately altered, changes in cytosolic nucleotide or citrate levels could not alter the net rate of glucose production without causing massive accumulation or depletion of intermediates. Since such accumulations of intermediates are not seen in vivo , the rate of gluconeogenesis appears to be controlled more by the rate of supply of phosphoenolpyruvate than by effects of adenine or pyridine nucleotides or by cytoplasmic citrate on individual gluconeogenic enzymes beyond enolase. Mechanisms by which the rate of glucose production may be altered by effects on phosphoenolpyruvate carboxykinase and pyruvate kinase are discussed.
Exserohilum and the compounding pharmacy: pushing the envelope of virulence

Summary Microorganisms poorly pathogenic for man may become significant causes of morbidity and mortality when inadvertently inoculated into normally sterile sites. Compounding pharmacies in the USA, not strictly overseen by the US Food and Drug Administration but by individual states, have been implicated in a number of clusters of such events. Recognized in the fall of 2012, fungus-tainted corticosteroid manufactured by a Massachusetts compounding pharmacy has caused the largest outbreak of this kind, affecting 751 people with, to date, 64 deaths. The etiology of the cases of meningitis, perispinal infection and septic arthritis was found to be, mostly, Exserohilum rostratum, a very uncommon human fungal pathogen. Prevention of future outbreaks such as this one will require an overhaul of the control over these industrialized compounding pharmacies and, until then, making both clinicians and patients alike aware of this issue in order for them to make informed decisions about these products and the risk of their use.
Type of interpolated activity and short-term memory: a note

as those used previously, with the following exceptions: (1) Fifteen Ss were presented a total of nine pairs of low meaningful CVCs by the paired-associate method. (2) Retention was measured as it was affected by the three types of interpolated materials (nothing, numbers, and CVCs) in combination with the three retention intervals (0, 8, and 16 sec.). The order of presentation of the materials was again counterbalanced and three trials were given. (3) Instead of having the various types of interpolated material both precede and follow the S-R pair to be learned, blank spaces preceded the presentation of the S-R pair and the three types of interpolated materials appeared only in the interval bemeen the presentation of the pair and the test of retention. (4) The S-R pair to be learned was "boxed" in black ink; Ss were specifically cold that the items in the boxes were the only ones which they would be asked to recall and that all other material was to be recited only. The results were essentially the same as those of the previous investigation. All the main effects of trials (F = 7.70, df = 2/28), retention interval (F = 70.71, df = 2/28), and type of interpolated material (F = 64.77, df = 2/28) were significant. In addition, the interactions of trials by interval (F = 3.14, df = 4/56), trials by material (F = 2.86, df = 4/56), and interval by material (F = 16.92, df = 4/56) were also significant. Thus, the results indicate that even when Ss can easily determine the items to be learned and focus their attention on them, the specific type of interpolated material remains a potent factor in short-term memory.
Film Archives of the National Archives of Zimbabwe

The National Archives of Zimbabwe ( NAZ) houses the film archives of the institution as well as other audiovisual material. This includes sound archives, slides and literature. The Unit used to be part of our Library until 1988, when it became separate. Assistance in setting up the Unit was obtained from the Beit Trust and Japan. The Beit Trust helped us secure a Steenbeck editing table and the Japanese donated the ultrasonic film cleaning machine and telecine equipment under the Japanese Cultural Grant Aid. The Japanese also donated a theatre projector which we have not been able to utilise since 1991 because there was no auditorium. However, the government has now provided the funds for the construction of an auditorium. ESARBICA Journal Vol.21 2002: 56-57
Hierarchical variable ordering for distributed constraint optimization

The Multiagent Agreement Problem (MAP) is a special form of Distributed Constraint Optimization (DCOP) that requires agents to choose values for variables to satisfy not only their own constraints, but also equality constraints with other agents. We introduce the AdoptMVA algorithm, an extension of the existing Adopt algorithm, designed to take advantage of MAP domains where agents often control multiple variables. We also propose an approach to agent ordering which leverages known ordering techniques from the centralized and distributed constraint satisfaction literature and applies them to MAPs. By combining ordering at the agent level with orderings at the variable level, we hope to obtain efficient global orderings. While the contributions discussed in this paper are applicable to general DCOPs, we focus our evaluation on MAPs because we feel it is a significant problem class worthy of specific attention.
Corn, Cucurbits, Cordage, and Colonization: An Absolute Chronology for the Appearance of Mesoamerican Domesticates and Perishables in the Jornada Basin, New Mexico

Detailed attribute analysis of basketry and cordage remains from Pendejo Cave and the region encompassed by the Jornada Basin in south-central New Mexico has suggested that the introduction of non-...
COMMUNICATION IN THE LANGUAGE CLASSROOM. Tony Lynch. Oxford: Oxford University Press, 1996. Pp. xvi + 174. $13.95 paper.

This book, an addition to the Oxford Handbooks for Language Teachers series, clearly falls on the applied end of the research-applied spectrum. Still, the author takes a gentle but insistent stance that research into communication provides practical insights to the classroom teacher.
Synthesis of 4-phosphono(difluoromethyl)-D,L-phenylalanine and N-boc and N-Fmoc derivatives suitably protected for solid-phase synthesis of nonhydrolyzable phosphotyrosyl peptide analogues

Abstract Synthesis of 4-phosphono(difluoromethyl)-D,L-phenylalanine as well as its diethyl phosphonate analogues bearing either Boc or Fmoc-amino protection are reported. The latter two derivatives were utilized for the solid-phase synthesis of SH2-related peptides containing nonhydrolyzable phosphotyrosyl mimetics.
An automated communication system in a contact registry for persons with rare diseases: scalable tools for identifying and recruiting clinical research participants.

Objectives Strategies for study recruitment are useful in clinical research network settings. We describe a registry of individuals who have self-identified with one of a multiplicity of rare diseases, and who express a willingness to be contacted regarding possible enrollment in clinical research studies. We evaluate this registry and supporting tools in terms of registry enrollment and impact on participation rates in advertised clinical research studies.
Hydrogen-oxygen Space Shuttle ACPS thruster technology review.

The generation of technology for injectors, cooled thrust chambers, valves, and ignition systems is discussed. The thrusters are designed to meet a unique and stringent set of requirements, including: long life for 100 mission reuses, high performance, light weight, ability to provide long duration firings as well as small impulse bits, ability to operate over wide ranges of propellant inlet conditions and to withstand reentry heating. The program has included evaluation of thrusters designed for ambient temperature and cold gaseous propellants at the vehicle interface.
Caught in the Act: the 1.5 A resolution crystal structures of the HIV-1 protease and the I54V mutant reveal a tetrahedral reaction intermediate.

HIV-1 protease (PR) is the target for several important antiviral drugs used in AIDS therapy. The drugs bind inside the active site cavity of PR where normally the viral polyprotein substrate is bound and hydrolyzed. We report two high-resolution crystal structures of wild-type PR (PRWT) and the multi-drug-resistant variant with the I54V mutation (PRI54V) in complex with a peptide at 1.46 and 1.50 A resolution, respectively. The peptide forms a gem-diol tetrahedral reaction intermediate (TI) in the crystal structures. Distinctive interactions are observed for the TI binding in the active site cavity of PRWT and PRI54V. The mutant PRI54V/TI complex has lost water-mediated hydrogen bond interactions with the amides of Ile50 and Ile50‘ in the flap. Hence, the structures provide insight into the mechanism of drug resistance arising from this mutation. The structures also illustrate an intermediate state in the hydrolysis reaction. One of the gem-diol hydroxide groups in the PRWT complex forms a very short (2....
Competing Influences in the Management of Gastrointestinal Bleeding

OBJECTIVES: Management of gastrointestinal (GI) bleeding centers on the issues of location, type of mucosal lesion, effects of anticoagulation, diagnosis, and therapy. Each one of these five individual factors is affected by multiple interactions with the other coexisting factors. The aim of the present study is to analyze which set of factors ultimately exerts the largest and most lasting influence on the disease process.
Quality Criteria for Digital Infrared Reference Spectra

Criteria for evaluating the quality of digital infrared refrence spectra are presented and discussed. A three-digit quality index is proposed, with the first digit representing sample authenticity and purity, the second digit representing the quality of sample preparation, and the third digit representing the stringency of the instrumental conditions used during the measurement. An algorithm for calculating this quality index is proposed.
On the efficacy of simplified 2D on-chip inductance models

Full three-dimensional (3D) inductance models of on-chip interconnect contain an extremely large number of forward coupling terms. It is therefore desirable to use a two-dimensional (2D) approximation in which forward couplings are not included. Unlike capacitive coupling, however, truncating mutual inductance terms can result in loss of accuracy and even instability. This paper investigates whether ignoring forward couplings is an acceptable choice for all good IC designs or if full 3D models are necessary in certain on-chip interconnect configurations. We show that the significance of the forward coupling inductance depends on various aspects of the design.
Contemporary analysis of early outcomes after lung transplantation in the elderly using a national registry

Background With an increasing number of potential recipients and a comparatively static number of donors, lung transplantation (LT) in the elderly has come under significant scrutiny. Previous studies have been limited by single-center experiences with small population sizes and often mixed results. Using a national registry, we sought to evaluate the following: (1) differences in survival outcomes in septuagenarians compared with sexagenarians; and (2) the effect of temporal trends on the development of other comorbidities in this population. Methods We analyzed the Scientific Registry of Transplant Recipients (SRTR) data files from the United Network for Organ Sharing (UNOS) database to identify recipients who underwent LT between the years 2000 and 2013. The study period was divided into two equal eras. Using Kaplan–Meier analysis, we compared the 30-day, 3-month, 1-year, 3-year and 5-year patient survival between septuagenarians and sexagenarians in both eras. Separate multivariate analyses were performed to estimate the risk of renal failure, risk of rejection and length of hospital stay (LOS) post-LT in each of these time periods. Results A total of 6,596 patients were identified comprising 1,726 (26.2%) during 2000 to 2005 and 4,870 (73.8%) during 2006 to 2012. In the "early era," 32 (1.9%) septuagenarians and 1,694 (98.1%) sexagenarians underwent LT, whereas 543 (11.1%) septuagenarians and 4,327 (88.9%) sexagenarians underwent transplantation in the "latter era." A comparison of patient survival between the two groups in the early era revealed no difference at 30 days (95.7% vs 93.8%, p = 0.65). However, 3-month (91.2% vs 75%, p = 0.04) and 1-year patient survival (79.5% vs 62.5%, p = 0.048) were both lower in the septuagenarian group. In the later era, however, there were no differences in 30-day (96.2% vs 96.8, p = 0.5), 3-month (92.7% vs 91.9%, p = 0.56) or 1-year (81.7% vs 78.6%, p = 0.12) patient survival between the two age groups. Survival rates at 3 years (63.7% vs 49.3%, p p Conclusion Overall, LT outcomes for the elderly have improved significantly over time and early outcomes in the modern era rival those found in younger recipients.
Molecular mechanisms of action of glyburide on the beta cell

A high-affinity sulfonylurea receptor has been identified on the plasma membrane of the beta cell. The potent second-generation sulfonylureas, glyburide and glipizide, saturate the receptor in the low nM concentration range, whereas first-generation drugs bind to and saturate the receptor in the microM range. For each of the sulfonylureas, there is excellent quantitative agreement among the equilibrium binding constant (Kd), the half-maximal inhibition of potassium ion (K+) efflux (K0.5), and the half-maximal stimulation of insulin secretion (ED50), when these values are obtained from insulin-secreting cell lines or from isolated mouse pancreatic islets. The inhibition of K+ efflux by the sulfonylureas, coupled with the sulfonylurea inhibition of the activity of a specific adenosine triphosphate (ATP)-sensitive K+ channel embedded in the plasma membrane of whole cells or in excised membrane patches, suggests that the sulfonylurea receptor is this channel protein or a closely associated subunit. The activity of the ATP-sensitive K+ channel is also controlled by the insulin secretagogues, glucose and certain amino acids. These compounds must be metabolized to inhibit the channel activity and appear to do so by increasing the level of ATP or by increasing the ATP/adenosine diphosphate (ADP) ratio. ATP reduces channel activity by binding to a specific nucleotide-binding site on the cytoplasmic surface of the protein. There is a synergy between the action of glucose and that of the sulfonylureas. The sulfonylureas, for example, are better effectors of insulin secretion in the presence of glucose. Inhibition of the ATP-sensitive K+ channels results in depolarization of the plasma membrane and a subsequent influx of extracellular calcium ions through voltage-dependent calcium channels. An increase in the free intracellular calcium level is the signal, or "second messenger," that triggers exocytosis and the release of insulin. The sulfonylurea receptor has a molecular weight of 140,000 and can be solubilized by digitonin, retaining the same rank order of sulfonylurea binding affinities as the membrane-bound protein. Several laboratories are currently purifying the receptor and/or cloning the receptor gene.
Single-block coded modulation for MINO systems

This paper introduces a new class of space-time codes that achieve coding gain without a trellis or any form of inter-block dependency. The construction of the new codes starts from an existing (parent) space-time block code (STBC). Then by increasing the constellation size followed by expurgation of the expanded codebook, a better code is obtained at the original transmission rate. This method can be applied to a wide variety of space-time block codes, including orthogonal codes and quasi-orthogonal codes. A multi-stage design algorithm is presented, and for orthogonal parent codes, an efficient decoding algorithm is developed, and its decoding complexity is analyzed. Despite altering the regular structure of the orthogonal code, the decoding complexity is only affected by a constant factor.