cssi/SciSciGPT-SciSciNet huggingface dataset:
Dilation with the Gruntzig Balloon Catheter for Peripheral Arterial Disease: Initial Experience in a Community Hospital

Intraluminal dilation using the Gruntzig catheter is a definitive procedure to correct obstructive arterial disease. Eleven procedures in 8 patients are reported. Six patients had progressive claudication and/or night pain, and 2 had advanced pre-gangrenous changes. Iliac, femoral, and/or trifurcation dilation of single or multiple lesions was successful in 9 (82%) extremities with documentation of widening of the arterial lumen. Clinical improvement was sustained for the short term followup (3-11 months, mean 7 months) except in 1 case where there was symptomatic relief for only 6 months. There were 2 technical failures (18%) in 1 patient due to bilateral calcific lesions. In some cases, the procedure should be performed in the operating room for immediate standby readiness of the surgical team and equipment. With this precaution in mind, the advantages of simplicity and repeatability suggest wider use of Gruntzig dilation.
Hormonal and neural modulation of physiological and behavioral function: An introduction to the symposium honoring Julian M. Davidson

Abstract A symposium honoring Julian M. Davidson on his retirement from the faculty at Stanford University School of Medicine, and celebrating his scientific contributions, was held on May 19, 1994 as a Satellite Symposium to the Third International Behavioral Neuroscience Conference. The papers arising from the symposium are introduced after a brief overview of Julian's contributions.
Form reproduction as a function of angularity, orientation of brightness contrast, and hue.

This is an evaluation of three stimulus variables (angularity and orientation, brightness contrast, and hue) involved in geometric (diamond-shaped) form reproductions of children between 6 and 14 y...
Evolving Treatment Strategies for Gallbladder Cancer

Gallbladder cancer is an uncommon cancer that has traditionally been associated with a poor prognosis. In the era of laparoscopic cholecystectomy, incidental gallbladder cancer has dramatically increased and now constitutes the major way patients present with gallbladder cancer. While patients with incidental gallbladder cancer have a better survival than patients with nonincidental gallbladder cancer, incidental gallbladder cancer can be associated with a varied prognosis. Imaging with computed tomography (CT), magnetic resonance imaging (MRI), and [18]F-fluorodeoxyglucose (FDG) positron emission tomography (PET), as well as diagnostic laparoscopy, all have varying roles in the workup of patients with incidental gallbladder cancer. For patients with T1b, T2, and T3 incidental gallbladder cancer re-resection is generally recommended. At re-exploration, many patients with incidental gallbladder cancer will have residual disease. Definitive oncologic management requires re-resection of the liver, portal lymphadenectomy, and attention to the common bile duct. The extent of the hepatic resection should be dictated by the ability to achieve a microscopically negative (R0) margin. Routine resection of the common bile duct is unnecessary but should be undertaken in the setting of a positive cystic duct margin. If an incidental gallbladder cancer is discovered at the time of surgery, whether the surgeon should directly proceed with a more definitive oncologic operation should depend on the surgeon’s skill-set and experience. Gallbladder cancer has a propensity to recur. Although data for adjuvant therapy following resection are limited, some data do suggest a survival benefit for adjuvant chemoradiation therapy. Management of patients with gallbladder cancer requires a multidisciplinary approach with input from a surgeon skilled in hepatobiliary surgery.
A simple headrest for patients confined to wheelchairs

Abstract A simple headrest technique for the patient confined to a wheelchair has been presented. This technique requires no custom made equipment, allows multiple positions for the headrest, positions the patient near the dental unit and light, and affords fast simple application. Alternative methods to this technique have been presented by Kilfoil and Popovitch 1 and others. 2–6
Multiobjective cloud capacity planning for time-varying customer demand

Service providers who dynamically scale cloud resources can significantly lower costs while providing a service level that conforms to a service level agreement. To do this, service providers must understand the tradeoffs within provisioning algorithms such as utilization versus system availability or the impact of service level agreement timescale on utilization. Within the context of three provisioning algorithms from existing literature, we analyze the tradeoff of service availability versus utilization using a two-dimensional Pareto analysis. We also analyze the impact on utilization and system availability of using hourly, daily, weekly, or yearlong timescales as the basis of service level agreement. We evaluate model performance using historical data of the Virtual Computing Laboratory (VCL), a cloud computing environment at North Carolina State University. We show that a simple heuristic planning model, whereby a fixed reserve capacity is maintained, provides better service availability and utilization performance than other models for all service level timescales. The fixed reserve capacity model is also shown to be Pareto optimal.
Effect of spacer layer thickness on magnetic interactions in self-assembled single domain iron nanoparticles

The magnetic characteristics of iron nanoparticles embedded in an alumina thin film matrix have been studied as a function of spacer layer thickness. Alumina as well as iron nanoparticles were deposited in a multilayered geometry using sequential pulsed laser deposition. The role of spacer layer thickness was investigated by making layered thin film composites with three different spacer layer thicknesses (6, 12, and 18nm) with fixed iron particle size of ∼13nm. Intralayer magnetic interactions being the same in each sample, the variation in coercivity and saturation magnetization is attributed to thickness dependent interlayer magnetic interactions of three types: exchange, strong dipolar, and weak dipolar. A thin film composite multilayer structure offers a continuously tunable strength of interparticle dipole-dipole interaction and is thus well suited for studies of the influence of interaction on the magnetic properties of small magnetic particle systems.
Studies on Starter Metabolism. IV. Effect of Various Substrates on the Formation of Acetoin by a Mixed Strain Starter Culture

Summary The mechanism and the source of carbon for the formation of acetoin by a mixed culture consisting predominantly of Streptococcus cremoris and Leuconostoc species have been studied, using both a reconstituted milk and a dialyzed milk medium. Of the various metabolites added to the dialyzed medium, only citric, oxalaoetic, pyruvic, and alpha -keto butyric acids stimulated the formation of ketol; the alpha -keto butyric acid gave rise to a ketol tentatively identified as 3-hydroxy-2-pentanone. Acetaldehyde, isobutyraldehydc, and crotonic acid inhibited acetoin formation. The tricarboxylic acid cycle intermediates, malic, succinic, cis -aconitic, and alpha -keto glutarie acid, had no effect. Using the dialyzed milk medium, it was shown that the addition of glucose alone did not result in the formation of acetoin, regardless of the initial pH of the medium. When citric acid alone was added, only a trace of acetoin was formed at pH 7.0, but a considerable amount was formed at pH 5.0. When glucose and citric acid were added, a considerable amount of acetoin was formed, regardless of the initial pH. Studies with various metabolic inhibitors indicated that, in general, the acid formation was more readily inhibited than was acetoin formation. At an inhibitor concentration such that a partial inhibition of the formation of acetoin was manifested, the addition of more citric acid overcame the inhibition. Alpha -acetolactic acid decarboxylase activity was demonstrated in the ground cells of a Leuconostoc isolate obtained from the mixed culture.
Spontaneous generation of infectious nucleating amyloids in the transmissible and nontransmissible cerebral amyloidoses

The unconventional viruses of the transmissible subacute spongiform encephalopathies (kuru-CJD-GSS-FFI-scrapie-BSE) are nucleants spontaneously generated from host precursor proteins altered to β-pleated sheet configuration that polymerize into insoluble infectious amyloid fibrils. Thede novo conversion to infectious amyloids is facilitated or accelerated by many different point mutations causing amino acid changes, a stop codon, or octapeptide inserts that increase the likelihood of spontaneous conversion to infectious configuration by many orders of magnitude. Similar nucleating induction of configurational change to amyloid probably occurs in other amyloidoses of brain and in systemic amyloidoses. Thus, all amyloids, particularly so-called fibrillar amyloid enhancing factors, may be considered to be infectious scrapie-like agents. These events probably occur extracellularly, thus we are attempting to reproduce them in vitro, even from synthetic polypeptides.
Label-Free Electrochemical Detection of DNA in Blood Serum via Target-Induced Resolution of an Electrode-Bound DNA Pseudoknot

We have demonstrated a fully covalent, signal-on E-DNA architecture based on the target-induced resolution of a DNA pseudokont. In the absence of target, the electrode-bound DNA probe adopts a pseudoknot conformation that segregates an attached methylene blue (MB) from the electrode. Upon target binding, the pseudoknot is resolved, leading to the formation of a single-stranded DNA element that supports electron transfer from the methylene blue to the electrode.
Functional Communication Training and Naltrexone Treatment of Self‐Injurious Behaviour: An Experimental Case Report

The self-injurious behaviour of people with intellectual disabilities, autism, and related developmental disabilities remains one of the most difficult behaviour problems to treat clinically. Two promising approaches to effective treatment involve teaching the person communication skills that are functionally equivalent to the self-injury or administering opiate antagonist medication. Here an experimental case study, in which naltrexone was combined with functional communication training, is reported. Using a within-subject ABCDC experimental design, reductions in rate of self-injury were observed during the naltrexone alone phase as well as during combined treatment phases. The implications of conducting a functional assessment prior to behavioural and pharmacological intervention are discussed.
The stabilization of formate on Pt(111) by coadsorbed atomic oxygen

Abstract We have studied the stabilization of adsorbed formate in the presence of coadsorbed atomic oxygen on Pt(111) using the techniques of thermal desorption spectroscopy and high-resolution electron energy loss spectroscopy. The increased stability manifests itself in two primary ways: the temperatures at which formic acid converts to formate, and formate converts to gaseous CO2, are lower and higher, respectively, than in the absence of oxygen; and the saturation yields of dehydrogenation products are approximately five times greater than those produced on the clean surface. The latter effect is coupled to an apparent increase in the sticking coefficient of the molecular acid.
Early specialization in surgical training: an old concept whose time has come?

The complexity of surgical science and surgical patient care is increasing at an accelerating pace. As a consequence, many areas of surgical practice once within the scope of general surgery have evolved into distinct specialties with unique advanced training requirements. Given this evolution in surgical specialization, many have considered that our current model of surgical training—a 5-year residency in general surgery, followed by any of a wide variety of fellowships to acquire refined, advanced training—is due for major restructuring. The current debate focuses on the benefits and potential disadvantages of earlier differentiation of surgeons into specialty training pathways. The structure of surgical training, including the definition of core surgical training and the optimal structure to introduce advanced specialty training tracks, is the central issue in this debate. This article reviews the question and current deliberations of the stakeholders in graduate surgical education and training.
Special Considerations in Vascular Anomalies: Airway Management

Vascular anomalies are disorders of abnormal vasculogenesis or lymphogenesis. All types of vascular anomalies may involve the airway, causing varying degrees of upper airway obstruction as well as dysphagia and bleeding. Certain signs and symptoms may implicate airway involvement with a hemangioma or vascular malformation. It is necessary to distinguish a vascular anomaly from other airway lesions such as a congenital cyst. This is accomplished with imaging and endoscopy.
Wall Leakage Effect on Nonuniformities in Diagonal MHD Channels

The effect of wall leakage, symmetric as well as asymmetric, is examined in the linear and nonlinear regimes. It is found that: the range of wavelength in the nonuniformities is reduced and in the asymmetric case splits into two separate passbands; depending on the wavelength, forward waves can propagate both upstream and downstream, and backward waves only upstream; the growth rate is minimal when the leakage at the cathode wall is four times that of the anode wall; and in all cases, a resistance introduced in the diagonal bars reduces the growth rate by a constant. Nomenclature h - width of the channel h' =/*tan0 H = electrode segmentation pitch Ie (k) =k mode component of the fluctuating current Ie (x) = total fluctuating current in the diagonal bars 70 = background dc current k = wave number Se = externally connected resistance in the diagonal bars x = longitudinal coordinate y = transverse coordinate 6 = angle of the diagonal link
Intensified/shuttered cooled CCD camera for dynamic proton radiography

ABSTRACT An intensifiedlshuttered cooled PC-based CCD camera system was designed and successfully fielded on proton radiographyexperiments at the Los Alamos National Laboratory LANSCE facility using 800-MeV protons. The four camera detectorsystem used front-illuminated full-frame CCD arrays (two 1024 x 1024 pixels and two 5 12 x 5 12 pixels) fiber opticallycoupled to either 25-mm diameter planar diode or microchannel plate image intensifiers which provided optical shuttering fortime resolved imaging of shock propagation in high explosives. The intensifiers also provided wavelength shifting and opticalgain. Typical sequences consisting of four images corresponding to consecutive exposures of about 500 ns duration for 40-usproton burst images (from a fast scintillating fiber array) separated by approximately I microsecond were taken during theradiography experiments. Camera design goals and measured performance characteristics including resolution, dynamicrange, responsivity, system detection quantum efficiency (DQE), and signal-to-noise will be discussed.KEYWORDS: high resolution, high speed, multi-frame, electro-optically shuttered, intensified, CCD camera system
A stochastic optimization of the production speed of robots based on measured geometric and nongeometric errors

A statistical model is established to estimate the effects of the geometric and nongeometric errors on the quality of the operation for various operating speeds. Furthermore, a stochasitc optimization problem is formulated to obtain the optimal operating speed for a given accuracy in the robotic operations. To demonstrate this approach, the experiments on a PUMA 560 robot are used as an example.
The spider and fly revisited: ploy-counterploy behavior in a unique predator-prey system

Earlier studies have shown that the sarcophagid fly Arachnidomyia lindae is the principal egg-sac predator of the colonial orb-weaving spider Metepeira incrassata, and that risk of egg-sac loss increases with group size. Observations of specialized behaviors for attack (flies) and defense (spiders) suggest that this predator–prey relationship may incorporate elements of ploy and counterploy behavior. Here we explore this relationship in detail and test hypotheses regarding efficacy of attack and defense behaviors. Egg-sac guarding by the spider includes defensive behaviors specific to this fly predator, which were observed during experimental "attacks" with tethered A. lindae, but not with similar presentations of non-predatory Musca domestica. Experimental studies also show that Metepeira incrassata recognizes this predatory fly by airborne cues (i.e., the signature frequency of wing-beats), and can distinguish between this predator and other flies (potential prey) on the basis of wing-beat frequency differences. Removal of female spiders results in a significantly higher probability of unguarded egg-sacs being parasitized, demonstrating the adaptive value of spider defensive behaviors. We also present evidence that A. lindae utilizes a behavioral ploy for circumventing spider guarding behavior (aggressive mimicry – producing vibrations of captured prey in the web), and that Metepeira incrassata, in turn, exhibits a counter-ploy behavior (signal thread cutting) to eliminate this potentially distracting vibratory information. While previous studies have shown that this colonial web-building spider uses a number of general attack-abatement mechanisms against a diversity of predators and parasitoids, results of this study suggest that selection pressures from a highly specialized predator may also result in evolution of predator-specific prey responses.
Water‐soluble nonionic surfactants for affinity bioseparations

Reversible competitive inhibitors of the three enzymes beta-galactosidase, trypsin, and serum cholinesterase have been covalently attached to nonionic ethoxylated surfactants. The binding of the resulting affinity-derivatized surfactants to the respective enzymes has been quantified by measuring Michaelis-Menten inhibition constants with kinetic assays. The surfactant-inhibitor of serum cholinesterase, octaethylene glycol monohexadecy ether pyridinium (C(16)E(8)-PYR), was adsorbed in aqueous solution to an octadecyl-bonded reverse-phase silica packing in a 2 x 0.2 cm stainless steel test column. The ability of the test column to function as a high-performance affinity chromatography (HPAC) column was determined by applying a mixture of bovine serum albumin and cholinesterase (4:1 w/w). Virtually all of the cholinesterase bound and was eluted by applying a gradient in ionic strength. The applied cholinfesterase was recovered with a yield of over 90% and an 11-fold purification. An aliquot of raw horse serum was then purified in the same fashion with a yield of 84% and a 280-fold purification. The surfactant-inhibitor was easily removed from the column with an alcohol wash for sterilization, cleaning, or application of a different affinity ligand. Moreover, the ligand density on the column can be easily manipulated by adsorbing mixtures of derivatized and underivatized surfactants. Leakage of ligands from the support seems to be minimal since the cholinesterase affinity column was operated efficiently after being exposed to 24,000 column volumes of buffer. The application of this technique to high-capacity, high-throughput reversible affinity purifications is limited only by the ability to identify suitable ligands.
Biarylcarboxylic Acids and -amides: Inhibition of Phosphodiesterase Type IV versus [3H]Rolipram Binding Activity and Their Relationship to Emetic Behavior in the Ferret

In addition to having desirable inhibitory effects on inflammation, anaphylaxis, and smooth muscle contraction, PDE-IV inhibitors also produce undesirable side effects including nausea and vomiting. In general, compounds that inhibit PDE-IV also potently displace [3H]rolipram from a high-affinity binding site in rat cortex. While this binding site has not been identified, it has been proposed to be an allosteric binding site on the PDE-IV enzyme. Preliminary studies have suggested that the emetic potency of PDE-IV inhibitors is correlated with affinity for the brain rolipram binding site rather than potency at inhibiting PDE-IV enzyme activity. Efforts to eliminate the emetic potential of PDE-IV inhibitors were directed toward developing compounds with decreased [3H]rolipram binding affinity while retaining PDE-IV potency. Thus, a novel series of 4-(3-alkoxy-4-methoxyphenyl)benzoic acids and their corresponding carboxamides were prepared and evaluated for their PDE-IV inhibitory and rolipram binding site properties. Modification of the catechol ether moiety led to phenylbutoxy and phenylpentoxy analogues that provided the desired activity profile. Specifically, 4-[3-(5-phenylpentoxy)-4-methoxyphenyl]-2-methylbenzoic acid, 18, was found to exhibit potent PDE-IV inhibitory activity (IC50 0.41 microM) and possessed 400 times weaker activity than rolipram for the [3H]rolipram binding site. In vivo, compound 18 was efficacious in the guinea pig aerosolized antigen induced airway obstruction assay (ED50 8.8 mg/kg, po) and demonstrated a significant reduction in emetic side effects (ferret, 20% emesis at 30 mg/kg, po).
The Larval Development of the Shrimp, Palaemon Macrodactylus Rathbun, Reared in the Laboratory, and the Effect of Eyestalk Extirpation On Development

[1. Le developpement larvaire de Palaemon macrodactylus Rathbun eleve dans le laboratoire est decrit de l'eclosion jusqu'a la postlarve. Les descriptions morphologiques sont presentees, aussi bien que les donnees sur la survie et sur le temps necessaire pour completer le developpement. Quelques variations sont discutees. 2. L'organe-X et la glande du sinus sont presents depuis le premier stade. On ignore si ces structures fonctionnent a ce stade. 3. Quelques experiences portant sur l'enlevement des pedoncules oculaires ont ete faites sur des animaux aux stades 2, 3 et 4. Des temoins operes (sans leurs deux antennules) et des temoins normaux ont ete employes. On n'a constate aucun changement dans la frequence de mue, mais les larves sans pedoncules oculaires sont devenues plus grandes que les temoins. Les animaux operes ont subi un retard dans la metamorphose, et montrent des etapes larvaires supplementaires. Quand la metamorphose survient, certains caracteres larvaires sont conserves par les animaux sans pedoncules oculaires., 1. Le developpement larvaire de Palaemon macrodactylus Rathbun eleve dans le laboratoire est decrit de l'eclosion jusqu'a la postlarve. Les descriptions morphologiques sont presentees, aussi bien que les donnees sur la survie et sur le temps necessaire pour completer le developpement. Quelques variations sont discutees. 2. L'organe-X et la glande du sinus sont presents depuis le premier stade. On ignore si ces structures fonctionnent a ce stade. 3. Quelques experiences portant sur l'enlevement des pedoncules oculaires ont ete faites sur des animaux aux stades 2, 3 et 4. Des temoins operes (sans leurs deux antennules) et des temoins normaux ont ete employes. On n'a constate aucun changement dans la frequence de mue, mais les larves sans pedoncules oculaires sont devenues plus grandes que les temoins. Les animaux operes ont subi un retard dans la metamorphose, et montrent des etapes larvaires supplementaires. Quand la metamorphose survient, certains caracteres larvaires sont conserves par les animaux sans pedoncules oculaires.]
Comparative uptake and metabolism of methazole in prickly sida and cotton

Abstract The comparative uptake and metabolism of 14 C-labeled 2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione (methazole), a herbicide, in prickly sida ( Sida spinosa L.) and cotton ( Gossypium hirsutum L.) were investigated as physiological bases for herbicidal selectivity, using thin layer chromatography, autoradiography, and liquid scintillation counting. Prickly sida and cotton readily absorbed and translocated 14 C from nutrient solution containing [ 14 C]methazole. Only acropetal translocation of 14 C was observed. Methazole was rapidly metabolized to 1-(3,4-dichlorophenyl)-3-methylurea (DCPMU) and other metabolites by both species. Although metabolism appeared to be qualitatively the same, quantitative differences between species were evident. Methazole was converted to DCPMU (also phytotoxic) more readily by prickly sida than cotton; however, DCPMU was more readily detoxified to 1-(3,4-dichlorophenyl) urea (DCPU) by cotton than prickly sida. More 14 C per unit weight was present in the prickly sida shoots than in cotton shoots. Also, a larger portion of the methanol-extractable 14 C was herbicidal in the shoots of prickly sida than of cotton. Thus, the differential tolerances of prickly sida and cotton to methazole may be explained, in part, by differential uptake and metabolism of methazole and DCPMU.
Applications of computational fluid dynamics-based methods to problems in computational science

Abstract The objective is to describe how some of the attributes of Computational Fluid Dynamics (CFD) can be extended to solve mathematical problems in other disciplines, such as electromagnetics, that are governed by appropriate partial differential equations and boundary conditions. The concept of finite-volume schemes applied to the conservation forms of fluid dynamics equations, such as the Euler and Navier-Stokes equations, is readily extendable to other equations. For example, Maxwell's equations of electromagnetics, when cast in conservation form, can be easily solved using characteristic theory-based CFD methods allowing for a precise implementation of material interface and other boundary conditions. The possibility of extending CFD-based methods to other disciplines has a special significance because increasingly the development of advanced aerospace systems requires a total integration of multidisciplinary technologies (aerodynamics, structures, propulsion, controls, low observables, etc.). Many of the computational issues such as (1) development of implicit/explicit, higher order accurate schemes, (2) complex geometry representation and setup of structured or unstructured grid cells, (3) vector/massively parallel computer architectures and execution/memory requirements, (4) pre/post processing graphics, and (5) user interface/training requirements, are common to many disciplines. The establishment of “Computational Science” to perform interdisciplinary coupled problems addressing many of the above computational issues can certainly benefit from the CFD experience. It is briefly explained how some of the CFD-based methods are applied to study scattering problems for radar cross section (RCS) studies, and simulation of laser/material interaction accounting for melting. Also mentioned are some of the interdisciplinary computations involving CFD, aeroelasticity, and controls. Future studies will include coupling of RCS and CFD in the design process.
A Conceptual and Empirical Investigation of Workplace Burnout in Foodservice Management

The authors conducted a study of burnout within the foodservice environments of five major hotel chains. The Maslach Burnout Inventory, a psychometric instrument, was used to measure three dimensions of burnout:• Emotional Exhaustion (EE)• Depersonalization (DP)• Personal Accomplishment (PA).Findings show a significant incidence of high burnout according to Maslach's three domains-especially on the emotional exhaustion (28%) and depersonalization (20%) subscales. We have also unequivocally demonstrated that the Maslach inventory is a reliable and valid instrument for measuring burnout in the food-service industry.
Microencapsulation of Cheese Ripening Systems: Production of Diacetyl and Acetoin in Cheese by Encapsulated Bacterial Cell-Free Extract

Abstract A cell-free extract of Streptococcus lactis subsp. diacetilactis was encapsulated with substrates and cofactors for generation of diacetyl and acetoin. This model system was used to demonstrate the feasibility of incorporating milk fat-coated microcapsules containing selected enzymes and substrates into cheese to enhance and regulate flavor development. Concentrations of diacetyl and acetoin in cheese containing encapsulated enzymes and substrates increased during ripening to eight times concentrations in control cheeses. This indicated that it was feasible to encapsulate a multi-enzyme system that would function in a typical, predictable manner.
Electronic structure of amino acids and ureas

Abstract The outer electronic levels of glycine, alanine, glycine ethyl ester, urea, and thiourea have been investigated by means of photoelectron spectroscopy using He I (584 A) and He II (304 A) radiation and CNDO/2 molecular orbital calculations. In the amino acids the molecular orbital (MO) ordering ha been found to be [σ core and carbonyl π > a″(O) a′(O) > a″(N)] with a first ionization potential of ∼8.8 eV. Glycine and alanine are foun to exist as the undissociated amino carboxylic acids rather than zwitterions in the high temperature vapor. In urea the three lowest energy molecular o are near-degenerate [σ(4b 1 ) ∼ π(1a 2 ) ∼ π(2b 2 )] while in thiourea only the two lowest energy MO's are near-degenerate [π(1a 2 σ(4b 1 ) ∼ π(2b 2 )]. The first ionization potentials of urea and thiourea are 9.7 and 7.9 eV respectively.
Polymerization kinetics of HEMA/DEGDMA: using changes in initiation and chain transfer rates to explore the effects of chain-length-dependent termination

The effect of kinetic chain length and chain transfer on the polymerization kinetics and network structure in polymerizations of loosely crosslinked 2-hydroxyethyl methacrylate/di(ethylene glycol) dimethacrylate mixtures was explored. Polymerization behavior of the monomer mixture in the presence and absence of a chain transfer agent was monitored at various initiation rates and chain transfer agent concentration levels. Dependence of the polymerization rate on the initiation rate was found to deviate from the classical square-root relationship because of chain-length-dependent termination. This effect was further confirmed by addition of a chain transfer agent. The presence of a chain transfer agent led to the formation of shorter kinetic chains, which enhanced termination and slowed the polymerization. Investigation of the polymerization kinetics after cessation of irradiation yielded kt/kp[M] values for both systems. Prior to the onset of reaction diffusion-controlled termination, the system that included a chain transfer agent exhibited much higher kt/kp[M] values than the polymerization system without added chain transfer agent. In addition, the onset of reaction diffusion-controlled termination was delayed to higher conversions in the system containing chain transfer agent. The impact of a chain transfer agent on the polymerization behavior and kinetics demonstrates that the chain-length-dependent termination phenomenon is indeed important and must be considered in kinetic modeling of loosely crosslinked systems.
Carbon monoxide and hydrogen coadsorption on polycrystalline platinum

Abstract The coadsorption of carbon monoxide and hydrogen was studied on a polycrystalline platinum foil. In a comparison with single crystal surfaces, the desorption kinetics of the individual species most closely resemble those on Pt(110). In coadsorption there is competition between CO and H2. Carbon monoxide completely blocks hydrogen adsorption, but on a hydrogen-saturated surface only two-thirds of the carbon nomoxide adsorption is blocked. Shifts in peak temperatures for hydrogen desorption indicate that repulsive interactions between adsorbed CO and H2 are important, and lead to segregated islands of the two adsorbates. Under some conditions there is also a new low temperature desorption peak for hydrogen which indicates that there are regions on the surface where carbon monoxide and hydrogen are intermixed.
Sump syndrome complicating Roux-en-Y hepaticojejunostomy: case report and review of the literature.

Sump syndrome is a rare complication of biliary-enteric anastomosis. Classically, the distal bile duct becomes obstructed by gastrointestinal debris after choledochoduodenostomy, resulting in cholangitis or, less commonly, pancreatitis. Obstruction of the biliary tree by gastrointestinal contents after Roux-en-Y choledochojejunostomy or hepaticojejunostomy has not been described in the English-language literature. This report details the diagnostic and operative management of the first patient with sump syndrome after hepaticojejunostomy. The presumed pathophysiology was reflux of vegetable matter up the efferent limb, resulting in hepatic duct obstruction and cholangitis. The patient ultimately required complex choledochoscopic drainage of the intrahepatic biliary tree and revision of the previous Roux-en-Y hepaticojejunostomy.
Control of interfacial instabilities using flow geometry

When a low-viscosity fluid penetrates a fluid of higher viscosity confined by parallel plates, finger-like patterns propagate at the interface between the two fluids. Experiments now show that tapering the fluid cell can suppress this instability - providing interfacial control via a simple change in geometry.
CONTROLLING CYTOSKELETON STRUCTURE BY PHOSPHOINOSITIDE-PROTEIN INTERACTIONS : PHOSPHOINOSITIDE BINDING PROTEIN DOMAINS AND EFFECTS OF LIPID PACKING

Cell movement and resistance to mechanical forces are largely governed by the cytoskeleton, a three-dimensional network of protein filaments that form viscoelastic networks within the cytoplasm. The cytoskeleton underlying the plasma membrane of most cells is rich in actin filaments whose assembly and disassembly are regulated by actin binding proteins that are stimulated or inhibited by signals received and transmitted at the membrane/cytoplasm interface. Inositol phospholipids, or phosphoinositides, are potent regulators of many actin binding proteins, and changes in the phosphorylation of specific phosphoinositide species or in their spatial localization are associated with cytoskeletal remodeling in vitro. This review will focus on recent studies directed at defining the structural features of phosphoinositide binding sites in actin binding proteins and on the influence of the physical state of phosphoinositides on their ability to interact with their target proteins.
Investigation of the human stem cell factor KIT ligand gene, KITLG, in women with 46,XX spontaneous premature ovarian failure

Objective To investigate mutations in the human KIT ligand gene ( KITLG ) gene as a mechanism of 46,XX spontaneous premature ovarian failure. The human KIT ligand gene, known also as human stem cell factor, is the ligand of the c-kit transmembrane tyrosine kinase receptor ( KIT ). This ligand–receptor interaction is known to play important roles in mouse germ cell migration and proliferation. Design Cross-sectional study. Setting Clinical research center. Patient(s) Forty women with 46,XX spontaneous premature ovarian failure. Intervention(s) None. Main Outcome Measure(s) Single-stranded conformational polymorphism analysis and DNA sequencing. Result(s) We found one nucleotide change of the KITLG coding region (811G→T) that led to an alteration of the amino acid composition of the KITLG protein in one Caucasian patient (Asp210Tyr). However, we found the same alteration in two normal control Caucasian samples. Three nucleotide substitutions were found in the noncoding exon of KITLG (exon 10). We also identified two intronic polymorphisms. Thus, we did not identify a single significant mutation in the coding region of the KITLG gene in any of 40 patients (upper 95% confidence limit is 7.2%). Conclusion(s) Mutations in the coding regions of the KITLG gene appear not to be a common cause of 46,XX spontaneous premature ovarian failure in North American women.
Laparoscopic closure of the nephrosplenic space for prevention of recurrent nephrosplenic entrapment of the ascending colon.

Objective To evaluate outcome after laparoscopic closure of the nephrosplenic space in horses that had previous nephrosplenic entrapment of ascending colon (left dorsal displacement of the left colon; LDDLC). Study Design Retrospective study. Sample Population Horses that had previous LDDLC. Methods Medical records of horses that had LDDLC and subsequent laparoscopic nephrosplenic space closure between 2002 and 2004 were retrieved. Follow-up information was obtained by telephone interview of owners. Preoperative versus postoperative comparisons were: incidence of LDDLC, incidence of colic signs, and incidence of ventral celiotomy. Data were analyzed using a χ2-square test with significance set at P<.05. Results Ten horses met the inclusion criteria. Mean follow-up was 22 months. No horses had recurrence of LDDLC; however, 3 horses had colic signs subsequently that required surgical intervention. Over the follow-up period there was a significant decrease in the total incidence of colic and ventral celiotomy. Technique modifications included use of different cannula site locations, use of polyglyconate suture material for nephrosplenic space closure, and development of a custom cannula. Conclusions Laparoscopic nephrosplenic space closure prevented recurrence of LDDLC, and significantly lowered the overall incidence of colic and ventral celiotomy. The custom-designed cannula provided good access to the operative site and no complications were encountered with use of polyglyconate suture material for nephrosplenic space closure. Clinical Relevance Closure of the nephrosplenic space will prevent LDDLC; however, other surgical lesions can occur.
Vibrational Overtone Spectroscopy of Ethylene Glycol Diacrylate and Ethylene Glycol Dimethacrylate, Monomer and Polymer

The vibrational overtone spectra of ethylene glycol diacrylate (EGDA) and ethylene glycol dimethacrylate (EGDMA) monomers and corresponding polymers were recorded in the spectral range 4500-15000 cm-1. This spectral range encompasses the first through the fourth CH stretch vibrational overtone transitions. The CH stretch spectral features were assigned by a comparison of the number and type of different CH oscillators in the two compounds and a comparison to the spectra of acrylic acid and ethylene glycol diisobutyrate. Peaks corresponding to transitions for the vinyl, methylenic, and methyl types of the CH stretch were identified. The anharmonicities and mechanical frequencies for each progression in each monomer and polymer sample are reported. From the integrated areas of the vinyl and methyl/methylenic peaks for the first, second, third, and fourth vibrational overtone transitions of EGDMA, the degree of polymerization was calculated. These results were compared to the degree of polymerization determined from IR spectroscopy.
Systemic acquired resistance induced by localized virus infections in plants.

Abstract Inoculation of half-leaves of Nicotiana tabacum var. Samsun NN, with tobacco mosaic (TMV) virus induced a high level of resistance to TMV in the opposite half-leaves. Challenge inoculation with TMV of the resistant half-leaves 7 days after the first inoculation resulted in limited lesion formation; the lesions were consistently only one-fifth to one-third as large (in diameter) as were lesions in susceptible half-leaves, and they usually were fewer in number. Similarly, inoculation of lower leaves on a plant induced resistance in upper leaves and vice versa. Resistance was first detected in 2–3 days, reached a maximum in about 7 days, and persisted for at least 20 days. The uninoculated resistant leaves or half-leaves proved to be free of virus. The highest level of resistance developed when plants were kept at 20°C before and after the challenge inoculation. Resistance could be detected in plants kept at 29° after challenge. Complete protection was not obtained by increasing the ratio of the area first inoculated to that challenged. Resistance was induced by mixed infections by TMV and potato virus X (PVX), but leaves highly resistant to TMV alone were only slightly resistant when challenged with TMV plus PVX. Resistance was induced by TMV infection in detached leaves, in excised shoots, and in plants kept in the dark 2 days before challenge inoculation. No resistance was induced by mechanical or chemical injury or by viruses that do not cause necrosis. The resistance induced by TMV is not specific for TMV. Leaves with TMV-induced resistance were resistant not only to TMV but also to tobacco necrosis virus, to turnip mosaic virus, and to tobacco and tomato ringspot viruses. The resistance was not as effective against these viruses as against TMV, but each of these local-lesion viruses induced a resistance in Samsun NN tobacco indistinguishable from that induced by TMV.
The Spirits of Conservation: Ecology, Christianity, and Resource Management in Highlands Papua New Guinea

In environmental circles, there are two long-running debates about (1) whether or not indigenous peoples are truly conservationists, and (2) whether or not Christianity is inherently inimical to conservation. In this article, I bring these two debates into dialogue by exploring the changes in resource management practices of an indigenous group in highlands Papua New Guinea, many of whom have recently converted to Christianity. In Porgera, spirits are critical for maintaining and regulating ecological affairs, so it could be assumed that Christianity would erode whatever conservationist principles are extant in traditional religious belief. This is not the case, however. Traditional, conservation-like practices were dependent upon particular spirits, resources, and ecological zones. Christianity has engaged with these spirits, resources, and zones in complex ways. I argue that we need more nuanced understandings of how the global spread of world religions are integrating with traditional resource management practices to more effectively promote sustainability.
Excitatory Amino Acid Neurotransmission: NMDA Receptors and Hebb-Type Synaptic Plasticity

The study of excitatory amino acids as neurotransmitters has recently resulted in many new and fundamental concepts in neuroscience. Much of this progress centers upon the role of N-methyl-D-aspartate (NMDA) receptors in CNS synaptic transmission and plasticity. In this review, we describe the properties of the excitatory amino acid receptor classes, particularly those of the NMDA class, and indicate how properties of this receptor permit a unifying concept for understanding plasticity associated with development and learning. Excitatory amino acids, primarily L-glutamate and related derivatives, are the major excitatory neurotransmitters in the vertebrate CNS. Exten­ sive biochemical, anatomical and electrophysiological analysis has shown that in corticofugal, corticocortical, and other pathways, the excitatory amino acids have the essential properties indicative of neurotransmitters (for reviews see Fagg & Foster 1983, Fonnum 1984, Cotman & Monaghan 1987). The excitatory amino acids act through multiple receptor classes, of which the NMDA receptor class is the most well understood. NMDA
Building spacetime meshes over arbitrary spatial domains

We present an algorithm to construct meshes suitable for spacetime discontinuous Galerkin finite-element methods. Our method generalizes and improves the ‘Tent Pitcher’ algorithm of Ungor and Sheffer. Given an arbitrary simplicially meshed domain X of any dimension and a time interval [0, T], our algorithm builds a simplicial mesh of the spacetime domain X × [0, T], in constant time per element. Our algorithm avoids the limitations of previous methods by carefully adapting the durations of spacetime elements to the local quality and feature size of the underlying space mesh.
Functional magnetic resonance imaging of methylphenidate and placebo in attention-deficit/hyperactivity disorder during the multi-source interference task.

Context: Previous studies have reported hypofunction, structural abnormalities, and biochemical abnormalities of the dorsal anterior midcingulate cortex (daMCC) in attention-deficit/hyperactivity disorder (ADHD). Stimulant medications are effective treatments for ADHD, but their neural effects have not been fully characterized. Objective: To determine whether the methylphenidate hydrochloride osmotic-release oral system (OROS) would increase functional magnetic resonance imaging (fMRI) activation, compared with placebo, in the daMCC and other frontoparietal regions subserving attention during the Multi-Source Interference Task (MSIT).
Trends in sexual behaviours and infections among young people in the United States

Objectives: To describe trends over time in sexual behaviour, condom use, and sexually transmitted infections among female and male adolescents in the United States. Methods: A review was carried out of published studies using data from six surveys since the 1970s on sexual behaviour and surveillance data on sexually transmitted infections. Results: The proportion of adolescents who have ever had sexual intercourse increased for females and males through the 1980s and then declined for males through the 1990s. Some survey data showed that the level remained unchanged in the 1990s for adolescent females and other sources showed a decline by 2001. Condom use at first sexual intercourse and current condom use have increased over the past two decades for both male and female adolescents. Incidence rates for gonorrhoea and syphilis among adolescents declined over the 1990s and up through 2002, though new diagnoses of HIV/AIDS among adolescents remained relatively constant throughout the 1990s and into the new century. Conclusion: Although data sources are difficult to compare over time, trends in sexual behaviour, condom use, and sexually transmitted infections among adolescents from different data sources display generally similar directions towards declines in risk behaviours and outcomes, and increases in protective behaviours.
In Vivo Delivery of Cytoplasmic RNA Virus-derived miRNAs

The discovery of microRNAs (miRNAs) revealed an unappreciated level of post-transcriptional control used by the cell to maintain optimal protein levels. This process has represented an attractive strategy for therapeutics that is currently limited by in vivo delivery constraints. Here, we describe the generation of a single-stranded, cytoplasmic virus of negative polarity capable of producing functional miRNAs. Cytoplasmic RNA virus-derived miRNAs accumulated to high levels in vitro, generated significant amounts of miRNA star strand, associated with the RNA-induced silencing complex (RISC), and conferred post transcriptional gene silencing in a sequence-specific manner. Furthermore, we demonstrate that these vectors could deliver miRNAs to a wide range of tissues, and sustain prolonged expression capable of achieving measurable knockdown of physiological targets in vivo. Taken together, these results validate noncanonical processing of cytoplasmic-derived miRNAs and provide a novel platform for small RNA delivery.
Surface dissociation of potassium chloride by low-energy electron bombardment

Abstract Surface dissociation of ultrahigh vacuum-cleaved KCl during low-energy electron irradiation has been observed. The method employs a mass spectrometer to measure the desorption rate of dissociation products and Auger electron spectroscopy for the determination of surface composition. The results show that K, Cl and Cl 2 are desorbed from the surface as neutrals. Above 100°C. desorption of constituents into the vacuum is believed to occur primarily through generation of bulk defects followed by diffusion transport to the surface and to a lesser extent, through direct dissociation at the surface. Auger electron spectroscopy measurements indicate that surface defects generated by moderate irradiation at room temperature or below are mainly chlorine-ion vacancies.