cssi/SciSciGPT-SciSciNet huggingface dataset:
Introduction of transposon Tn916 DNA into Haemophilus influenzae and Haemophilus parainfluenzae.

Enterococcus (Streptococcus) faecalis transposon Tn916 was introduced into Haemophilus influenzae Rd and Haemophilus parainfluenzae by transformation and demonstrated to transpose efficiently. Haemophilus transformants resistant to tetracycline were observed at a frequency of approximately 3 x 10(2) to 5 x 10(3)/micrograms of either pAM120 (pGL101::Tn916) or pAM180 (pAM81::Tn916) plasmid DNAs, which are incapable of autonomous replication in this host. Restriction enzyme analysis and Southern blot hybridization revealed that (i) Tn916 integrates into many different sites in the H. influenzae and H. parainfluenzae genomes; (ii) only the 16.4-kilobase-pair Tn916 DNA integrates, and no vector DNA was detected; and (iii) the Tetr phenotype was stable in the absence of selective pressure. Second-generation Tn916 transformants occurred at the high frequency of chromosomal markers and retained their original chromosomal locations. Similar results were obtained with H. influenzae Rd BC200 rec-1 as the recipient strain, which suggests host rec functions are not required in Tn916 integrative transposition. Transposition with Tn916 is an important procedure for mutagenesis of Haemophilus species.
Connection topology optimization of steel moment frames using metaheuristic algorithms

Abstract This paper details the optimization of steel moment frames in which, in addition to the beam and column sections, the beam-to-column connection type is also variable. In these connection topology optimizations, the optimal trade-off between the lateral stiffness provided by moment connections and lower cost of pin connections is determined by identifying the most efficient arrangement of moment connections. Four metaheuristic algorithms are used to optimize two different frames and their performance is compared. Results indicate that the cost of a frame is minimized when moment connections are arranged in a manner that resembles a global structural system.
Picosecond fluorescence kinetics and energy transfer in chloroplasts and algae

Abstract Single-photon timing with picosecond resolution is used to investigate the kinetics of the fluorescence emission of chlorophyll a in chloroplasts from spinach and pea and in the algae Chlorella pyrenoidosa and Chlamydomonas reinhardii. The fluorescence decay is best described by three exponential components in all species. At low light intensity and with open reaction centers of Photosystem II (F0), we find lifetimes of approx. 100, 400 and 1100 ps for the three components. Closing the reaction centers by addition of 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea plus hydroxylamine and by increasing light intensity produces only minor changes in the almost constant fast- and medium-lifetime components; however, there is a dramatic increase in the yield of the slow component, by a factor of about 20, accompanied by only a modest increase in the lifetime to 2200 ps (Fmax). In good agreement with previous fluorescence lifetime measurements, we find an increase in the averaged lifetime of the three components from 0.5 to 2.0 ns, which is proportional to the 4-fold increase in the total fluorescence yield. Our time-resolved results are inconsistent with models which are based on the proportionality between lifetime and yield and which involve a homogeneous origin of fluorescence that is sensitive to the state of the reaction centers. We conclude that the variable part of the fluorescence, which is dominated by the slow phase, reflects the kinetics of charge recombination in the reaction center, as proposed previously (Klimov, V.V., Allakhverdiev, S.I. and Paschenko, V.Z. (1978) Dokl. Akad. Nauk S.S.S.R. 242, 1204–1207). The modest increase in lifetime of the slow phase indicates the presence of some energy transfer between photosynthetic units.
Concurrent Cloud-to-Ground Lightning and Precipitation Enhancement in the Atlanta, Georgia (United States), Urban Region

Abstract This study explores how the Atlanta, Georgia (United States), urban region influences warm-season (May through September) cloud-to-ground lightning flashes and precipitation. Eight years (1995–2003) of flashes from the National Lightning Detection Network and mean accumulated precipitation from the North American Regional Reanalysis model were mapped under seven different wind speed and direction combinations derived from cluster analysis. Overlays of these data affirmed a consistent coupling of lightning and precipitation enhancement around Atlanta. Maxima in precipitation and lightning shifted in response to changes in wind direction. Differences in the patterns of flash metrics (flash counts versus thunderstorm counts), the absence of any strong urban signal in the flashes of individual thunderstorms, and the scales over which flashes and precipitation enhancement developed are discussed in light of their support for land-cover- and aerosol-based mechanisms of urban weather modification. This ...
Cataract surgical skill assessment tools

After publication of the Accreditation Council for Graduate Medical Education's required competencies for residency training programs, ophthalmology training programs began developing objective assessments to measure resident surgical skill. The application of these evaluation tools represents a move toward standardization in the resident educational process. This review of the assessment tools found that the evaluation rubrics for cataract surgery vary in their level of reliability and validity. Currently, variations in reliability and validity are the only measure of true differences in the evaluation rubrics. Future studies will determine which of the assessment tools is the most practical and efficient for resident training. Financial Disclosure Neither author has a financial or proprietary interest in any material or method mentioned.
A solid-phase immunoassay for detection of IgA1 protease activity on agar plates.

Abstract An immunoassay was developed which is capable of detecting IgA1 protease positive microorganisms from biologically derived samples grown on agar plates. Activity was detected by overlaying plates with agar containing insolubilized IgA and capturing Fab fragments on nitrocellulose disks coated with anti-λ light chain. Using cultures of human saliva, a comparison of this assay with a more traditional method involving electrophoresis and Western blotting of individual colony material revealed excellent agreement between the two methods. This assay should be useful in studying the distribution and ecology of organisms producing IgA1 protease, and in assessing its potential as a virulence factor.
Numerical algebraic geometry and kinematics

Numerical algebraic geometry uses numerical methods, principally numerical tracking of paths defined by polynomial homotopies, to find and manipulate algebraic sets defined by systems of polynomial equations. Kinematics is the study of the geometrical aspects of mechanical motion. The kinematical problems arising in the analysis and design of most robots and mechanisms are essentially algebraic, because these devices are well-modeled as rigid bodies in contact along algebraic surfaces. In particular, the constraints imposed by the most common types of joints, such as simple hinges or ball-and-socket joints, are equivalent to containments of linear features (points, lines, and planes) that are maintained during rigid body motion of the parts. Kinematical studies have driven the development of numerical algebraic geometry and remain one of its most important application areas. Numerical algebraic geometry has proven to be particularly apt for the natural parameterizations presented by problems from kinematics. This extended abstract gives brief overviews of basic numerical algebraic geometry and kinematics.
Extinction of premixed H2/air flames: Chemical kinetics and molecular diffusion effects

Laminar flame speed has traditionally been used for the partial validation of flame kinetics. In most cases, however, its accurate determination requires extensive data processing and/or extrapolations, thus rendering the measurement of this fundamental flame property indirect. Additionally, the presence of flame front instabilities does not conform to the definition of laminar flame speed. This is the case for Le<1 flames, with the most notable example being ultralean H{sub 2}/air flames, which develop cellular structures at low strain rates so that determination of laminar flame speeds for such mixtures is not possible. Thus, this low-temperature regime of H{sub 2} oxidation has not been validated systematically in flames. In the present investigation, an alternative/supplemental approach is proposed that includes the experimental determination of extinction strain rates for these flames, and these rates are compared with the predictions of direct numerical simulations. This approach is meaningful for two reasons: (1) Extinction strain rates can be measured directly, as opposed to laminar flame speeds, and (2) while the unstretched lean H{sub 2}/air flames are cellular, the stretched ones are not, thus making comparisons between experiment and simulations meaningful. Such comparisons revealed serious discrepancies between experiments and simulations for ultralean H{sub 2}/air flames bymore » using four kinetic mechanisms. Additional studies were conducted for lean and near-stoichiometric H{sub 2}/air flames diluted with various amounts of N{sub 2}. Similarly to the ultralean flames, significant discrepancies between experimental and predicted extinction strain rates were also found. To identify the possible sources of such discrepancies, the effect of uncertainties on the diffusion coefficients was assessed and an improved treatment of diffusion coefficients was advanced and implemented. Under the conditions considered in this study, the sensitivity of diffusion coefficients to the extinction response was found to be significant and, for certain species, greater than that of the kinetic rate constants.« less
Inhibition of Hepatitis C Virus Replication by Intracellular Delivery of Multiple siRNAs by Nanosomes

Sustained antiviral responses of chronic hepatitis C virus (HCV) infection have improved recently by the use of direct-acting antiviral agents along with interferon (IFN)-α and ribavirin. However, the emergence of drug-resistant variants is expected to be a major problem. We describe here a novel combinatorial small interfering RNA (siRNA) nanosome-based antiviral approach to clear HCV infection. Multiple siRNAs targeted to the highly conserved 5′-untranslated region (UTR) of the HCV genome were synthesized and encapsulated into lipid nanoparticles called nanosomes. We show that siRNA can be repeatedly delivered to 100% of cells in culture using nanosomes without toxicity. Six siRNAs dramatically reduced HCV replication in both the replicon and infectious cell culture model. Repeated treatments with two siRNAs were better than a single siRNA treatment in minimizing the development of an escape mutant, resulting in rapid inhibition of viral replication. Systemic administration of combinatorial siRNA-nanosomes is well tolerated in BALB/c mice without liver injury or histological toxicity. As a proof-of-principle, we showed that systemic injections of siRNA nanosomes significantly reduced HCV replication in a liver tumor-xenotransplant mouse model of HCV. Our results indicate that systemic delivery of combinatorial siRNA nanosomes can be used to minimize the development of escape mutants and inhibition of HCV infection.
ANTIOXIDANT POTENTIAL OF 5-n-PENTADECYLRESORCINOL

The antioxidant potential of 5-n-pentadecylresorcinol was determined with five different oils. Alkylresordnol (AR) was added at 0.025%, 0.050% and 0.075%, respectively. For comparison, 0.01% butylated hydroxyanisole (BHA) was used as antioxidant. Oils were incubated at 10, 25 and 40C. Peroxide values were determined at different time intervals. Accelerated tests using a pro-oxidant were also conducted with each oil. AR was shown to slow oxidative rancidity of the oils. The ability of AR to slow lipid oxidation in cereal products was also studied. Wheat bran, rye bran and whole grain millet meal were treated with 0.050% and 0.075% AR and BHA, respectively, and stored at 40C. Peroxide values were determined at different time intervals. AR was shown to slow lipid oxidation in cereal products.
Wetting Hysteresis, Metastability, and Droplet Impact on Superhydrophobic Surfaces

We study the wetting energetics and wetting hysteresis of sessile and impacting water droplets on superhydrophobic surfaces as a function of surface texture and surface energy. For sessile drops, we find three wetting regimes on these surfaces: equilibrium Cassie at small feature spacing, equilibrium Wenzel at large feature spacing, and an intermediate state at medium feature spacing. We observe minimum wetting hysteresis not on surfaces that exhibit Cassie wetting but rather on surfaces in the intermediate regime. We argue that droplets on these surfaces are metastable Cassie droplets whose internal Laplace pressure is insufficient to overcome the energy barrier required to homogeneously wet the surface. These metastable Cassie droplets show superior roll-off properties because the effective length of the contact line that is pinned to the surface is reduced. We develop a model that can predict the transition between the metastable Cassie and Wenzel regimes by comparing the Laplace pressure of the drop to the capillary pressure associated with the wetting-energy barrier of the textured surface. In the case of impacting droplets the water hammer and Bernoulli pressures must be compared with the capillary pressure. Experiments with impacting droplets show very good agreement with this simple pressure-balance model.Copyright © 2009 by ASME
The Benefit of Negative Examples: What We Can Learn about Leadership from the Taliban.

Approximately four months ago I was sitting at my desk at the Air Force Academy preparing a course in leadership that I would be teaching during the fall semester. Then, something happened that would have a drastic impact on my professional life as an educator and a military officer. I was informed that I would be deploying to Kabul, Afghanistan, for the next six months to support Operation Enduring Freedom. At first, I was a little taken aback by the opportunity since I had planned a summer of lesson prepping and writing, as I have found this to be the best time for such endeavors. However, after a little reflection, I quickly realized what a great opportunity for me to grow as an educator by giving me a chance to see leadership from different perspectives. While I am a career military officer and have seen many examples of leadership both positive and negative, this particular situation would afford me the opportunity to see leadership from an entirely different vantage point.
κ²-Coordination of 18-crown-6 to Ce(III) cations: solution dynamics and reactivity.

The coordination of 18-crown-6 to Ce[N(SiMe3)PhF]3 (PhF = pentafluorophenyl) results in a κ2-18-crown-6 complex, a unique coordination mode for an f-block cation. The κ2-18-crown-6 complex showed exchange with free 18-crown-6 in solution and facile rearrangement of the crown ligand into a κ6-18-crown-6 cerium complex.
Application of liquid crystals to boundary- layer visualization.

Liquid crystals applied to flow visualization, discussing potential for boundary layer or surface temperature measurement in aerodynamic testing
A List of French Similes

Author's Summary— A list of the usual comparisons is certain to enrich and render more concrete one's use of any language, but such a compilation is especially a propos for so picturesque a language as the French. Being English-French, the present list is available to all readers of the Journal.
Marine Ostracoda from Western North Atlantic Ocean off the Virginia Coast

Thirty-nine species of marine benthonic ostracods are reported from the coast of Virginia. Three species,Callistocythere reticulata, Cytherura pseudostriata andTriginglymus denticulata are described as new. A comparison of the previously reported ostracods and the presently reported ostracods is made. It is suggested that the present ostracol fauna is closely related to the fossil Tertiary ostracod fauna of Virginia and surrounding areas.
GLP-1 promotes angiogenesis in human endothelial cells in a dose-dependent manner, through the Akt, Src and PKC pathways.

Abstract Introduction Novel anti-diabetic medications that mimic or augment the physiological actions of GLP-1 improve cardiovascular risk factors in diabetics and GLP-1 has been proposed to have a beneficial role in the cardiovascular system. GLP-1 may have a direct cardioprotective role by decreasing infarct size and protecting from ischemia–reperfusion injury while prolonging survival in rodent models. The mechanisms underlying these observations remain largely unknown. In vitro studies suggest that GLP-1 may promote endothelial cell proliferation, but no study to date has evaluated a potential direct effect of GLP-1 on angiogenesis. Specific Aim To evaluate whether GLP-1 affects angiogenesis in humans and to elucidate underlying molecular mechanisms. Material and Methods We utilized a 3D culture system where spherules of human umbilical vein endothelial cells (HUVECs) embedded in a collagen scaffold were treated with escalating doses of human recombinant GLP-1 (50–2000 nmol/L) and the formation of new vessels was observed and quantified. Signaling inhibitors were utilized to identify molecular pathways through which GLP-1 promotes angiogenesis. Results We demonstrate that GLP-1 promotes angiogenesis in a dose-dependent manner. The maximum effect on angiogenesis was observed at a GLP-1 dose of 500 nmol/L, while increased angiogenesis occurred in response to doses ranging from 200 nmol/L to 1000 nmol/L. Pre-treatment of the system with Akt inhibitor IV, Bisindolylmaleimide (PKC inhibitor) and src inhibitor I resulted in a significant decrease of the GLP-1 induced angiogenesis. Conclusions This is the first study to demonstrate that GLP-1 promotes angiogenesis in a HUVEC three dimensional in vitro model. This effect requires pharmacological doses and is mediated through the Akt, PKC and src pathways.
Head blighting potential of Fusarium species associated with spring wheat heads

Seven Fusarium species isolated from spring wheat heads were tested for pathogenicity. Only F. graminearum and F. culmorum caused severe blighting of wheat heads following inoculation in the greenhouse. F. tricincium, F. sporotrichioides, F. equiseti, F. acuminalum, and F. poae did not blight heads but sometimes caused damage to inoculated spikelets.
Some deleterious consequences of the act of recollection

Two experiments investigated the impact of responding to recognition test items that do not include a correct alternative. In Experiment 1, subjects who were given exclusively incorrect response alternatives were less likely than control subjects to favor the correct alternatives on a second recognition test. Analysis of subjects’ responses indicated that commitments, rather than distractor familiarity, was the main source of this effect. In Experiment 2, an impairing effect of committing to an incorrect alternative was observed even when the initial distractors were excluded from the final test. Thus, this decreased performance cannot simply be attributed to a bias toward remaining consistent. One interpretation of these results is that committing to a distractor causes subjects to remember a false detail that can interfere with their later ability to access the original information. Other potential theoretical and applied implications of these results are explored.
Alkylation of isocitrate lyase from Escherichia coli by 3-bromopyruvate

The inactivation of tetrameric isocitrate lyase from Escherichia coli by 3-bromopyruvate, exhibiting saturation kinetics, is accompanied by the loss of one sulfhydryl per subunit. The substrates glyoxylate and isocitrate protect against inactivation whereas the substrate succinate does not. The modification by 3-bromopyruvate (equimolar to subunits) imparts striking resistance to digestion of isocitrate lyase by trypsin, chymotrypsin, and V8 protease as well as a major decrease in the intensity of tryptophan fluorescence. After alkylation, the sequence GlyHisMetGlyGlyLys is found following the modified Cys residue in the tryptic peptide representing positions 196–201. Thus Cys195 is alkylated by 3-bromopyruvate.
Solute-solvent interaction in pyridine*

Summary The nature of the interaction between MA and solvent pyridine to form the pyridinium species, pyrMA, is being investigated on the basis of the electrochemical reduction of the pyridinium moiety; M is a Lewis acid, e.g., a proton, a metal ion, a tetraalkylammonium ion or an alkyl group. The anion A influences the various equilibria involving the pyridinium species through (a) its chemical type, e.g., whether derived from a carboxylic acid, a phenol or a heterocyclic ring, (b) the contribution of the dispersion effect to the medium effect on free energy in connection with specific solute-solvent interaction, (c) the association of M and A in the MA species, e.g., as measured in pyridine, water and other solvents, and (d) interactions involving other ions present such as those of the background electrolyte in polarography. Ion association and ion exchange involving competitive Lewis acids are important and can be evaluated by spectrophotometric, potentiometric and conductometric measurements, as well as by polarography. The overall influence of the solvent on the pyridinium equilibria is illustrated by the effect of the addition of water.
The extended stress field around a cylindrical crack using the theory of dislocation pile-ups

Abstract The extended stresses field around a cylindrical crack in an infinite homogeneous isotropic elastic medium is obtained by modeling the crack as a pile-up of Somigliana ring dislocations. The solution is based on the analytical expressions obtained earlier for the ring dislocation. A continuous distribution of dislocation densities modeling the crack is obtained in an approximate analytical form by means of a collocation technique for the solution of a pair of Cauchy singular integral equations of the first kind, resulting from the application of mixed boundary conditions for the cylindrical crack. The substitution of this closed form into the previously known stress expressions for the ring dislocation and integration over the crack length gives the extended stress field for the cylindrical crack. The analysis of the stress field around the cylindrical crack and ring dislocation reveals that the far tip stress field of the cylindrical crack can be represented by a pair of superdislocations provided that the strength and location are chosen appropriately for the pair of superdislocations. This provides analytical expressions for the far tip stress field and makes the solution to the crack-crack interaction problem possible.
Is there a trade-off between domestic and international publications?

Abstract This paper examines how a reputation-seeking academic economist allocates his time between research and nonresearch activities to publish papers in domestic and international journals. In equilibrium there is a trade-off between domestic and international publications. One implication is that the observed differences in academic productivity between American and European economists reflected by rankings can be misleading. The model allows for the existence of productive and efficient scholars even when their names do not appear in the rankings. The reason is that some scholars are publishing in domestic rather than in international journals, in accordance with the incentives in their home countries.
Anisotropic compressibility and effects of pressure on the electronic structure and Tc of Hg-based superconductors

Abstract Total energy local density calculations of the effects of pressure on the HgBa2Can-1CunO2n+2+δ (n = 1,2,3) superconductors show that the compressibility is anisotropic. Estimates of the bond compressibilities show that the Cu-O(2) (apical) bond is extremely compressible, while the Hg-O(2) bond is the least compressible. A simple model is proposed to describe compressibilities of Hg-1212, Hg-1223 and Hg-1234 on the basis of results obtained for the infinite layer (Sr1-xCax)1-yCuO2 and Hg-1201 compounds. The energy location of the van Hove singularity (vHs) - important in several theories of high-Tc superconductivity - is found to move towards EF with pressure, thereby showing a correspondence between the number of holes (from dopants) needed to shift EF down to the vHs and the pressure needed to be applied to a fixed dopant material to achieve the best Tc. Some consequences for understanding the pressure effects on the Tc of the Hg superconductors and possible experiments are suggested.
Fuly Distributed Cost Pricing, Ramsey Pricing, and Shapley Value Pricing: A Simulated Welfare Analysis for the Telephone Exchange

Economic theory has long been concerned with determining the optimal pricing scheme for a multiproduct monopoly, but it has been quite difficult to make use of developments in practice. Using LECOM, the Local Exchange Cost Optimization Model, over three stylized city maps, and assuming price elasticity values taken from the literature for four standard outputs of the local exchange, we demonstrate how fully distributed cost prices, Ramsey-optimal prices, Shapley prices, and standalone prices can be computed for a variety of baseline output levels. Analysis of consumer surplus changes relative to the marginal cost baseline shows that while Ramsey pricing maximizes social welfare over the set of schemes considered, only the Shapley approach results in subsidy-free prices.
A Method for Online Monitoring of Polydispersity during Polymerization Reactions

Building on a recently introduced technique for continuous online monitoring of absolute weight-average molecular weight Mw of polymers during polymerization reactions, a method is introduced here for finding a useful approximation to the polymer mass distribution and moments at each instant during the reaction. The method is based on finding the instantaneous weight-average mass at each instant, Mw,inst, from an expression involving the derivative of the cumulative Mw, which is directly monitored online. The method is restricted to chain growth polymerization where individual chains are produced and terminate rapidly compared to the overall time it takes for complete monomer conversion to polymer. Data from two different polymerization experiments that were monitored online were then analyzed. One of these experiments is from a reaction for poly(vinylpyrrolidone), which produced a bimodal population, and the other from a reaction that produced a broad, unimodal distribution. Finally, other possibilities for online polydispersity measurements are briefly discussed.
The ARPA internet protocol

Abstract A variety of computer networks are interconnected by gateway computers in the ARPA internetwork system. Processes on different networks may exchange messages with each other by means of an Internet Protocol which must be implemented in each subscriber (host) computer and in the gateways. The Internet Protocol is a relatively simple protocol that provides for the delivery of individual messages (datagrams) with high but not perfect reliability. This Internet Protocol does not replace the existing protocol in any network, but is used by processes to extend the range of communications. Messages in Internet Protocol are transmitted through any individual network by encapsulating them in that network's protocol. This paper presents an overview of the Internet Protocol and the operation of the gateway computers in the ARPA internet system.
Public case-base and tool kit using a validated RRM

Software systems are important, yet poorly understood entities. Users, and at times even developers, do not always understand what is occurring within the software in use. The Exploratory Visualization project attempts to address the technical issues involved in helping users understand running computations, especially long-lived distributed computations. The three facets of this problem that we investigate in our project are 1) creating accurate views of a running execution, 2) providing comprehensive and efficient access to a computation, and 3) responding to the user's interactions to promote understanding and optimize data collection.
Differential and geometric properties of Rayleigh quotients with applications

In this paper, learning rules are proposed for simultaneous computation of minor eigenvectors of a covariance matrix. To understand the optimality conditions of Rayleigh quotients, many interesting identities and properties related are derived. For example, it is shown that the Hessian matrix is singular at each critical point of the Rayleigh quotient. Based on these properties, MCA rules are derived by optimizing a weighted inverse Rayleigh quotient so that the optimum weights at equilibrium points are exactly the desired eigenvectors of a covariance matrix instead of an arbitrary orthonormal basis of the minor sub-space. Variations of the derived MCA learning rules are obtained by imposing orthogonal and quadratic constraints and change of variables. Some of the proposed algorithms can also perform PCA by merely changing the sign of the step-size.
The iatrogenic ureterovaginal fistula.

A 46-year-old woman underwent a robotic-assisted laparoscopic hysterectomy with bilateral salpingo-oophorectomy for the treatment of endometriosis. Two weeks postoperatively, she presented with pelvic pain and vaginal drainage. A right ureterovaginal fistula was diagnosed with the assistance of computed tomography (CT) urography and nephrostogram.
Muscle wasting from kidney failure—A model for catabolic conditions☆

Purpose Muscle atrophy is a frequent complication of chronic kidney disease (CKD) and is associated with increased morbidity and mortality. The processes causing loss of muscle mass are also present in several catabolic conditions. Understanding the pathogenesis of CKD-induced muscle loss could lead to therapeutic interventions that prevent muscle wasting in CKD and potentially, other catabolic conditions.
A Comparison of Torque Required to Fracture Rotary Files With Tips Bound in Simulated Curved Canal

The purpose of this study was to compare torque force and rotation needed to fracture three types of nickel titanium alloy rotary instruments in a simulated curved root canal space that were bound at the file tip. Files of similar size tips were studied. The files studied were ProFiles with 0.04 taper diameters of 15, 20, 25, 30, 35, 40, 45; 0.04 ProFile GT sizes 20, 30, 40; and ProTaper files sizes S1, S2, F1, F2, and F3. All files were 25 mm in length. Unwinding was defined as the rotation in degrees it took for a file to fracture after the first evidence of permanent deformation. All files exhibited permanent deformation before breaking, with the ProFile GT files demonstrating the greatest unwinding. The #45 0.04 ProFile withstood the most force while the #20 ProFile GT required the least amount of force before beginning to exhibit permanent deformation. The S1 and S2 ProTaper files fractured with so little rotation that no extended data were recorded. Generally, as the file diameter increased, the force needed to begin unwinding also increased. Also, as the file diameter increased, the force needed to fracture also increased.
Exploring the computing literature using temporal graph visualization

We present a system for the visualization of computing literature with an emphasis on collaboration patterns, interactions between related research specialties and the evolution of these characteristics through time. Our computing literature visualization system, has four major components: A mapping of bibliographical data to relational schema coupled with an RDBMS to store the relational data, an interactive GUI that allows queries and the dynamic construction of graphs, a temporal graph layout algorithm, and an interactive visualization tool. We use a novel technique for visualization of large graphs that evolve through time. Given a dynamic graph, the layout algorithm produces two-dimensional representations of each timeslice, while preserving the mental map of the graph from one slice to the next. A combined view, with all the timeslices can also be viewed and explored. For our analysis we use data from the Association of Computing Machinery's Digital Library of Scientific Literature which contains more than one hundred thousand research papers and authors. Our system can be found online at http://tgrip.cs.arizona.edu.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Low-energy neutral-atom imaging techniques

The potential scientific return from low energy neutral atom (LENA) imaging of the magnetosphere is extraordinary. The technical challenges of LENA detection include (1) removal of LENAs from the tremendous ambient UV without losing information of their incident trajectories, (2) quantification of their trajectories, and (3) obtaining high sensitivity measurements. Two techniques that have been proposed for this purpose are based on fundamentally different atomic interaction mechanisms between LENAs and a solid: LENA transmission through an ultrathin foil and LENA reflection from a solid surface. Both of these methods provide LENA ionization (for subsequent removal from the UV by electrostatic deflection) and secondary electron emission (for start pulse generation for time-of-flight and/or coincidence). We present a comparative study of the transmission and reflection techniques based on differences in atomic interactions with solids and surfaces. We show that transmission yield an order of magnitude greater secondary electron emission than reflection methods. Transmission methods are shown to be sufficient for LEAN energies of approximately 1 keV to greater than 30 keV.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Magnetic bipolarons in oxide superconductors

Abstract It is argued that magnetic bipolarons may be formed in high T c oxide superconductors. The superconducting phase could be attributed to the Bose-Einstein condensation of these bipolarons.
Validation of a morphometric analysis procedure using indomethacin-induced alterations in cultured hepatocytes.

Morphometric analysis was used to quantitate indomethacin-induced morphological changes in primary cultures of neonatal rat hepatocytes by comparison with standard assessments of functional integrity (i.e. enzyme release, urea levels, and dye exclusion). For this procedural validation, indomethacin concentrations were selected to correspond to the therapeutic plasma levels of rheumatoid arthritic or systemic lupus erythematosus patients having liver cell injury secondary to prolonged, high-dose administration of this nonsteroidal antiinflammatory agent. Primary cultures of neonatal rat hepatocytes were exposed for 12 h to 0, 100, 500 or 1000 microM indomethacin and subjected to a double-blind morphometric analysis procedure modified for use on cultured cells. This procedure systematically converted two-dimensional morphologic information into three-dimensional numerical data for statistical analysis. These optical measurements provided an accurate analysis following 4 h of measurements. When the concentration of indomethacin was increased from 0 to 1000 microM, the relative volume percent of Type I cells decreased. Therefore these cells, which were indistinguishable from healthy, untreated control cells, become less numerous as toxicant level increased. In contrast, the relative volume percent values of other progressively more damaged cell types (i.e. Types II, III, and IV cells) increased with elevation of indomethacin levels. Morphometric assessments paralleled functional assessments of indomethacin-induced cytotoxicity (r2: 0.88-0.99). Therefore, the present study validated this morphometric analysis procedure using a rigorous cellular exposure which caused substantial cell injury and subsequent lifting of 23% cells from the substrate. Combined with previous validation studies involving cadmium, erythromycin and benoxaprofen, the present study showed that morphometric analysis is a rapid, accurate method for the measurement of cell injury in cultured parenchymal hepatocytes.
An overview of artificial intelligence and robotics. Volume 2: Robotics

This report provides an overview of the rapidly changing field of robotics. The report incorporates definitions of the various types of robots, a summary of the basic concepts, utilized in each of the many technical areas, review of the state of the art and statistics of robot manufacture and usage. Particular attention is paid to the status of robot development, the organizations involved, their activities, and their funding.
New results of general n-dimensional incompressible Navier–Stokes equations

Let u=u(x,t,u0) represent the global strong/weak solutions of the Cauchy problems for the general n-dimensional incompressible Navier–Stokes equations ut+eΔ2nut−αΔu+(u⋅∇)u+∇p+(β⋅∇)u=0,∇⋅u=0,u(x,0)=u0(x),∇⋅u0=0, where the spatial dimension n⩾2, 0⩽e⩽1 is a constant and β=(β1,β2,…,βn)T∈Rn is a constant vector. Note that if e=0 and β=0, then the problem reduces to the traditional Navier–Stokes equations. Let the scalar functions ϕij∈C2(Rn)∩L1(Rn), ∂ϕij∂xj∈L1(Rn)∩H2n(Rn), i,j∈{1,2,…,n}. Define the real vector-valued functions Φi=(ϕi1,ϕi2,…,ϕin)T. Let the initial data u0(x)=(∑j=1n∂ϕ1j∂xj(x),∑j=1n∂ϕ2j∂xj(x),…,∑j=1n∂ϕnj∂xj(x))T satisfy ∑i=1n∑j=1n∂2ϕij∂xi∂xj(x)=0. Then limt→∞{(1+t)1+n/2∫Rn[|u(x,t)|2+e|Δnu(x,t)|2]dx}=1(2π)n(π2α)n/214α∑k=1n[∫RnΦk(x)dx]2. For any integer m⩾1, we will establish the following limit limt→∞{(1+t)2m+1+n/2∫Rn[|Δmu(x,t)|2+e|Δm+nu(x,t)|2]dx}=1(2π)n(π2α)n/2(14α)2m+1[∏l=12m(2l+n)]∑k=1n[∫RnΦk(x)dx]2. This kind of exact limit will have great influence on the Hausdorff dimension of the global attractor of the model equations.
Humor, Aging, and Life Review: Survival Through the Use of Humor

Humor has been shown to assist in the process of aging, particularly in improving health, reducing stress, and improving psychological well-being. This article addresses the tasks of aging, or what Erickson (1963) terms, “the end stage of life,” through the lens of humor. These issues include: identity, self-esteem, heritage and culture, mortality, loss, and self-worth.
Impact of state mandatory insurance coverage on the use of diabetes preventive care

46 U.S. states and the District of Columbia have passed laws and regulations mandating that health insurance plans cover diabetes treatment and preventive care. Previous research on state mandates suggested that these policies had little impact, since many health plans already covered the benefits. Here, we analyze the contents of and model the effect of state mandates. We examined how state mandates impacted the likelihood of using three types of diabetes preventive care: annual eye exams, annual foot exams, and performing daily self-monitoring of blood glucose (SMBG). We collected information on diabetes benefits specified in state mandates and time the mandates were enacted. To assess impact, we used data that the Behavioral Risk Factor Surveillance System gathered between 1996 and 2000. 4,797 individuals with self-reported diabetes and covered by private insurance were included; 3,195 of these resided in the 16 states that passed state mandates between 1997 and 1999; 1,602 resided in the 8 states or the District of Columbia without state mandates by 2000. Multivariate logistic regression models (with state fixed effect, controlling for patient demographic characteristics and socio-economic status, state characteristics, and time trend) were used to model the association between passing state mandates and the usage of the forms of diabetes preventive care, both individually and collectively. All 16 states that passed mandates between 1997 and 1999 required coverage of diabetic monitors and strips, while 15 states required coverage of diabetes self management education. Only 1 state required coverage of periodic eye and foot exams. State mandates were positively associated with a 6.3 (P = 0.04) and a 5.8 (P = 0.03) percentage point increase in the probability of privately insured diabetic patient's performing SMBG and simultaneous receiving all three preventive care, respectively; state mandates were not significantly associated with receiving annual diabetic eye (0.05 percentage points decrease, P = 0.92) or foot exams (2.3 percentage points increase, P = 0.45). Effects of state mandates varied by preventive care type, with state mandates being associated with a small increase in SMBG. We found no evidence that state mandates were effective in increasing receipt of annual eye or foot exams. The small or non-significant effects might be attributed to small numbers of insured people not having the benefits prior to the mandates' passage. If state mandates' purpose is to provide improved benefits to many persons, policy makers should consider determining the number of people who might benefit prior to passing the mandate.
Relationships between the threshold and slope of psychometric and neurometric functions during perceptual learning: implications for neuronal pooling.

Perceptual learning involves long-lasting improvements in the ability to perceive simple sensory stimuli. Some forms of perceptual learning are thought to involve an increasingly selective readout of sensory neurons that are most sensitive to the trained stimulus. Here we report novel changes in the relationship between the threshold and slope of the psychometric function during learning that are consistent with such changes in readout and can provide insights into the underlying neural mechanisms. In monkeys trained on a direction-discrimination task, perceptual improvements corresponded to lower psychometric thresholds and slightly shallower slopes. However, this relationship between threshold and slope was much weaker in comparable, ideal-observer “neurometric” functions of neurons in the middle temporal (MT) area, which represent sensory information used to perform the task and whose response properties did not change with training. We propose a linear/nonlinear pooling scheme to account for these results. According to this scheme, MT responses are pooled via linear weights that change with training to more selectively read out responses from the most sensitive neurons, thereby reducing predicted thresholds. An additional nonlinear (power-law) transformation does not change with training and causes the predicted psychometric function to become shallower as uninformative neurons are eliminated from the pooled signal. We show that this scheme is consistent with the measured changes in psychometric threshold and slope throughout training. The results suggest that some forms of perceptual learning involve improvements in a process akin to selective attention that pools the most informative neural signals to guide behavior.
Memory and Recognition of a Non-Target During a Threat Detection Visual Search Task

Context plays an important role in visual search tasks. The ability of people to form implicit associations about the objects in the world around them not only assists them in focusing their attention but also in simplifying their world. The goal of this study was to investigate whether, and how, people utilize “distractors” as contextual cues during a visual target search. Twenty undergraduate participants performed a luggage-screening task, where they were asked to locate a specific target (a knife). First, participants were trained using 25 luggage images, each of which contained a target (i.e., knife) and a specific distractor (i.e., iPod). During the post-training session, participants screened 100 bags with target base rate set at 50%. The bags contained either the distractor and the target (25 bags), the target only (25 bags), the distractor only (25 bags), or neither the distractor nor the target (25 bags). Participants’ dwell times and fixation counts for specific areas of interest (AOI) were ass...
Sex Pheromones of Noctuid Moths. II. Mating Behavior of Trichoplusia ni (Lepidoptera: Noctuidae) with Special Reference to the Role of the Sex Pheromone

The mating behavior of Trichoplusia ni (Hubner) was studied among caged individuals in the laboratory. Differences among the sexes in the timing of nocturnal flight behavior were associated with 2 factors: Most females flew actively while ovipositing during the first half of the night, but did not tend to fly during the second half, when mating occurred; males remained relatively inactive during the first half of the night, but increased their flight activity, especially when stimulated by the female sex pheromone, during the second half. In crowding experiments, mating took place in cages having an available volume of only 35 ml per moth. Elimination of visual or auditory stimuli did not prevent mating. A single 5-minute period of COs anesthetization on the day of emergence from the pupa did not reduce the mating frequency. Although a small proportion of females was capable of mating on the night following their emergence, most females mated for the first time on the second or third nights. The mean female mating frequency was approximately 2.0. Except for 1 or 2 nights of no copulatory activity immediately following emergence and prior to death, males transferred a spermatophore almost every night as long as receptive females were available. Females produce the sex pheromone in glands in the terminal segments of the abdomen and release the pheromone when they assume a typical receptive posture. An analysis of copulatory behavior revealed that the sex pheromone alone stimulated a complex sequence of male responses which began with the arousal of the male from a resting state at some distance from the female and culminated in an accurately directed copulatory motion. The antennae of the male form the principal site for perception of the pheromone. It is suggested that the relative location of the site from which the pheromone is volatilizing, with respect to the antennae, determines the direction in which the abdomen is curved in a copulatory attempt. No evidence was found through behavioral experimentation that a possible pheromone secreted by the male has any effect upon female behavior.
Reticulocyte sequestration in spleens of normal, anaemic and leukaemic rats.

Summary. Isolated spleens of normal, anaemic, and leukaemic rats were perfused with blood containing 2.7% reticulocytes collected from non-bled rats and 12.1 and 22.4% reticulocytes collected from bled rats. From 2 to 11% of the reticulocytes in the blood were sequestered in the spleens, depending on (1) the level of reticulocytes in the blood, (2) whether the cells were macrocytic or normal-sized reticulocytes, (3) the length of time of perfusion, and (4) the physiological condition of the spleen. The higher the reticulocyte percentage in the blood the greater the number of reticulocytes sequestered. A higher percentage of macrocytic reticulocytes was sequestered than normal-sized reticulocytes. The longer the perfusion the greater the number of cells sequestered, the percentage of cells sequestered decreasing with time. No differences were observed between the sequestering capacity of spleens of normal and anaemic rats but the capacity of spleens of leukaemic rats was usually decreased. The results indicate that the rat spleen can sequester reticulocytes but that this capacity would not perceptibly influence blood reticulocyte levels in the intact animal.