cssi/SciSciGPT-SciSciNet huggingface dataset:
An Efficient Methodology for Fatigue Reliability Analysis for Mechanical Components

This paper presents an efficient methodology to solve a fatigue reliability problem. The fatigue failure mechanism and its reliability assessment must be treated as a rate process since, in general, the capacity of the component and material itself changes irreversibly with time. However, when fatigue life is predicted using the S-N curve and a damage summation scheme, the time dependent stress can be represented as several time-independent stress levels using the cycle counting approach. Since, in each counted stress cycle, the stress amplitude is constant, it becomes a random variable problem. The purpose of this study is to develop a methodology and algorithm to solve this converted random variable problem by combining the accumulated damage analysis with the first-order reliability analysis (FORM) to evaluate fatigue reliability. This task was tackled by determining a reliability factor using an inverse reliability analysis. The theoretical background and algorithm for the proposed approach to reliability analysis will be introduced based on fatigue failure modes of mechanical components. This paper will draw on an exploration of the ability to predict spectral fatigue life and to assess the corresponding reliability under a given dynamic environment. Next, the process for carrying out this integrated method of analysis will be explained. Use of the proposed methodology will allow for the prediction of mechanical component fatigue reliability according to different mission requirements.
Vertical and temporal distribution of Fusarium solani and Heterodera glycines in fields with sudden death syndrome of soybean

Abstract Sudden death syndrome (SDS) is an important soilborne disease of soybean caused by the fungus Fusarium solani . This disease is also associated with the soybean cyst nematode (SCN), Heterodera glycines . To quantify the vertical and temporal distribution of these pathogens in the soil profile, a study was conducted at the University of Arkansas Pine Tree (PTS) and Cotton Branch Stations (CBS) in 1991. Soil samples were taken at six depths (0 to 7, 7 to 15, 15 to 30, 30 to 50, 50 to 75 and 75 to 100 cm) at four growth stages (planting, R2, R6 and harvest) and numbers of F. solani , SCN and total fungi were determined. Soil physical and chemical characteristics were measured at planting and soybean root densities were measured at R2 and R6. Disease development was followed weekly in August and September. Soil numbers of F. solani were greatest in the top 15 cm of soil throughout the season. SCN egg numbers also were greatest in this zone until harvest. At harvest, numbers significantly increased at depths of at least 50 cm. The greatest root densities were in the 0- to 15-cm zone. At both locations, the 0- to 15-cm zone was over a plow pan under which the pH decreased from 6.4 to 7.0 above the pan to 3.8 to 4.5 below the pan. Total fungal numbers were greatest in the upper soil layers at planting but declined until there were no significant differences in numbers of total fungi with depth from R2 to harvest. SDS developed sooner and was more severe at PTS than at CBS. PTS had greater numbers of F. solani but supported lower numbers of SCN at the end of the season than CBS.
Optimal Control of Desensitizing Inputs: The Case of Paylean

We examine production economic implications of a specialized input to which a biological system (e.g., an animal) becomes desensitized over time, but its marginal productivity can be restored by increasing the dosage level. Optimal dosage levels and their timing become choice variables and may substitute or complement other inputs. This analysis is demonstrated for the case of Paylean in swine production. Use of a step-up approach to optimal Paylean use is shown to return substantial value, especially in market structures that reward producers for lean carcass value, and in cases where the health status of the animals is compromised.
IsdG and IsdI, Heme-degrading Enzymes in the Cytoplasm of Staphylococcus aureus

Staphylococcus aureus requires iron for growth and utilizes heme as a source of iron during infection. Staphylococcal surface proteins capture hemoglobin, release heme from hemoglobin and transport this compound across the cell wall envelope and plasma membrane into the bacterial cytoplasm. Here we show that Staphylococcus aureus isdG and isdI encode cytoplasmic proteins with heme binding properties. IsdG and IsdI cleave the tetrapyrrol ring structure of heme in the presence of NADPH cytochrome P450 reductase, thereby releasing iron. Further, IsdI complements the heme utilization deficiency of a Corynebacterium ulcerans heme oxygenase mutant, demonstrating in vivo activity of this enzyme. Although Staphylococcus epidermidis, Listeria monocytogenes, and Bacillus anthracis encode homologues of IsdG and IsdI, these proteins are not found in other bacteria or mammals. Thus, it appears that bacterial pathogens evolved different strategies to retrieve iron from scavenged heme molecules and that staphylococcal IsdG and IsdI represent examples of bacterial heme-oxygenases.
Effects of Moderate and High Doses of Marihuana on Thermal Pain: A Sensory Decision Theory Analysis

: Sixteen habitual marihuana users, selected for their good mental and physical health, were hospitalized for three months in the New York State Psychiatric Institute. During the first month, the subjects were drug free; during the second month, they smoked marihuana cigarettes provided by NIDA (2% THC, 20 mg per cigarette) at the rate of 3 to 12 a day. A modified Hardy-Wolff dolorimeter was used to present 20 thermal stimuli of 30-second duration in a random manner at nine different intensities. Subjects responded from a 14-category scale, and data were analyzed according to sensory decision theory analysis. During the third month, the subjects were again drug free. At the noxious thermal intensities, there was a decrease in the pain report criterion during the first two weeks of smoking. The pain enhancement effect was followed by return to the presmoking pain level during weeks 3 and 4 and in the postsmoking period, indicating that tolerance had developed. There was also an increase in pain discriminability during the four weeks of smoking which extended for one week after smoking. Tolerance developed to the pain report criterion but not to the thermal discriminability. This study suggests that marihuana may have hyperalgesic activity and probably enhances the perception of pain, in moderate smokers. In contrast, heavy smoking had little effect on discriminability and caused an increase in the pain report criterion.
Optimisation of single-queue service delivery systems using a Markovian approach

Service delivery systems, such as banks and airport checking terminals, are faced with the daunting task of processing an increasing demand of customers. At the same time, customers have to make accept, reject or reprocess decisions for the service being offered (when given a choice). Single-server systems are simple and can be utilised as preliminary models, but most organisations generally use multi-server service delivery systems, which require more complex modelling. Modelling of the systems state using Markovian and queuing models provides a more robust approach to better understand the dynamics of the service delivery system, thereby enabling improved services based on anticipated demand variations. In addition, it provides a means to ensure an effective cost minimisation and an increased profit for the service delivery organisation. Therefore, this research proposes a Markovian-based conceptual model to optimise general service delivery systems. To illustrate the model, a numerical example for both single- and multi-server service delivery systems to determine the optimum system parameters is presented and solved. The results obtained showed that the net profit is very sensitive to both the service and arrival rates, among other parameters.
Assessing English vocabulary and enhancing young English as a Foreign Language (EFL) learners’ motivation through games, songs, and stories

In Taiwan, English was only officially taught at the secondary and tertiary levels before 2001. Since 2001, English courses have been formally incorporated into the curriculum in primary schools. Research on teaching and assessing English in primary school education is relatively new compared with research on other levels of education in Taiwan. The present study investigated the degree to which games, songs, and stories helped increase primary school pupils’ English vocabulary size and encouraged learning in an intensive English course. It also explored how different test techniques influenced pupils’ performance on a vocabulary test. Seventy-two primary school pupils participated in the study. The results showed that games, songs, and stories had a positive effect on learning and increasing the pupils’ English vocabulary. In the vocabulary test, the pupils in higher grades outperformed those in lower grades and performed differently in terms of test techniques.
A versatile, inexpensive, intuitive and simple system for computer-assisted instruction in radiology

A system for constructing courseware in Radiology is described. It uses widely available, inexpensive hardware and software to produce material that is versatile and easy to use. The computer-naive student readily interacts with both text and images. We briefly describe the hardware, the software, the development process, and the different prototype applications developed at this time.
Mechanisms of Guinier–Preston zone hardening in the athermal limit

Abstract The interaction of dislocations with Guinier–Preston (GP) zones is a process that contributes to the yield strength of many underaged precipitate-strengthened alloys. Here we use atomistic modeling to investigate this process in an Al–Cu alloy using a newly developed interatomic potential. The study focuses on edge dislocation interactions in the athermal limit. The critical shear stress and the mechanism by which dislocations overcome GP zones is found to vary significantly depending upon GP zone size, orientation and offset from the dislocation glide plane. Dislocation cutting, looping, leading partial cutting with trailing partial looping, diffusionless climb and defect nucleation at the dislocation–GP zone contact point are all observed. In the majority of cases dislocation looping is the controlling mechanism, challenging the applicability of traditional continuum dislocation cutting models to the underaged Al–Cu system at 0 K.
TU‐EE‐A2‐02: Fractionated Grid Therapy in Treating Cervical Cancers: Hypo‐Fractionation Or Conventional Fractionation?

Purpose: To evaluate the hypo‐fractionated and conventionally fractionated grid therapy in treating cervical cancers.Material and methods: A Monte Carlo technique was employed to calculate dose distribution of a commercially available grid. Based on the previously validated Monte Carlo technique, our new study has considered the divergence of all holes and thus improved the accuracy of grid geometry description in the simulations. The linear‐quadratic (LQ) model is used to evaluate the therapeutic outcome of both the hypo‐fractionated (fewer fractions and higher dose/fraction, herein 15 Gy/fraction) and conventionally fractionated (2Gy/fraction) regimens using grid therapy to treat cervical tumors that were represented by different radio‐biological responses. Results: The dose profiles and 2D dose distributions at dmax (d=1.5 cm) and 5 cm depths in water were obtained. An excellent agreement of dose profiles between calculated and measured was confirmed. The tumor cell and normal tissue survival statistics of grid therapy for two types of treatment regimens were calculated using the 2‐D dose distributions at the depth of 5 cm, and the therapeutic ratios and equivalent open field doses were obtained. Conclusions: The consideration of the divergence of grid holes has improved the Monte Carlo simulation results. In both the hypo‐fractionated and conventionally fractionated regimens, the therapeutic ratio depends not only on the single α/β value, but also on the individual α and β values. There is a significant therapeutic advantage of grid therapy for treating the studied cervical cancer cells because of their large α/β values, and the normal tissue sparing effect for the hypo‐fractionation regimen with few fractions is comparable to the conventional fractionation regimen with many fractions. For the radiosensitive normal tissues, both regimens give almost the same results, but for the radio‐resistant normal tissue the conventional fractionation regimen is preferred to spare them.
The hair of the dog

Abstract A single-center randomized double dummy study was undertaken in 116 patients; 59 were randomized to mesalamine and 57 to receive a nonpathogenic strain of Escherichia coli. In addition, all patients received standard medical therapy, together with a 1-wk course of oral gentamicin. After remission, patients were maintained on either mesalamine or E. coli and observed for a maximum of 12 months. Duration of remission was slightly higher in the mesalamine group than in the E. coli group (206 vs 185 days). Similarly, the percentages of patients undergoing remission were equivalent (73% and 67%), again slightly favoring the mesalamine group. The authors, therefore, conclude that a nonpathogenic strain of E. coli has an effectiveness almost equivalent to mesalamine’s in maintaining remission of ulcerative colitis.
A Microfluidic Approach to Pulsatile Delivery of Drugs for Neurobiological Studies

We present an innovative microfluidic approach to transcranial delivery of small quantities of drugs in brief time pulses for neurobiological studies. The approach is based on a two-stage process of consecutive drug dispensing and delivery, demonstrated by a device featuring a fully planar design in which the microfluidic components are integrated in a single layer. This 2-D configuration offers ease in device fabrication and is compatible to diverse actuation schemes. A compliance-based and normally closed check valve is used to couple the microchannels that are responsible for drug dispensing and delivery. Brief pneumatic pressure pulses are used to mobilize buffer and drug solutions, which are injected via a cannula into brain tissue. Thus, the device can potentially allow transcranial drug delivery and can also be potentially extended to enable transdermal drug delivery. We have characterized the device by measuring the dispensed and delivered volumes under varying pneumatic driving pressures and pulse durations, the standby diffusive leakage, and the repeatability in the delivery of multiple pulses of drug solutions. Results demonstrate that the device is capable of accurately dispensing and delivering drug solutions 5 to 70 nL in volume within time pulses as brief as 50 ms, with negligible diffusive drug leakage over a practically relevant time scale. Furthermore, testing of pulsatile drug delivery into intact mouse brain tissue has been performed to demonstrate the potential application of the device to neurobiology.
Satellite observed seasonal and inter-annual variation of vegetation over the Kalahari, the Great Victoria Desert, and the Great Sandy Desert - 1979-1984

Time-series observations by two spaceborne sensors over three desert regions, the Kalahari (in southern Africa) and the Great Victoria Desert and the Great Sandy Desert (in western Australia), are presented. The observations are by the Advanced Very High Resolution Radiometer on board the NOAA-7 satellite from April 1982 to December 1984, and by the Scanning Multichannel Microwave Radiometer on board the Nimbus-7 satellite from January 1979 to February 1985. The objective was to compare and contrast seasonal and interannual variation of vegetation over these three deserts using the normalized difference vegetation index and the 37 GHz brightness temperature. The seasonal variation from both sensors was found to be most pronounced over the Kalahari, followed by the Great Sandy Desert and the Great Victoria Desert. The normalized difference vegetation index was roughly identical over the two Australian deserts and was significantly higher for the Kalahari. There was no consistent change from both sensors over the two Australian deserts, but a consistent decrease from 1979 to 1984 over the Kalahari was found in the 37 GHz microwave data.
Nonuniqueness in direct and inverse electromagnetic scattering theory

General statements of impossibility can be important in science and engineering. Ambiguities in inverse problems are cases of non-uniqueness where classes of different objects give the same response. A strong ambiguity is one which no additional data will remove the non- uniqueness, whereas a weak ambiguity is one which can be removed by additional data. In direct scattering theory, different potentials with one or more trapped modes may give the same R(k) or the ei(alpha )R(k) where (alpha) is a real parameter at all wave-numbers k. In three-dimensional direct scattering theory, different material media and sources J, p give the same scattering matrix at all times (or wave numbers) at all scattering angles and all incident angles. Examples of strong ambiguities will be given including one where a temporal relaxation of a homogeneous body is equivalent to a totally different time-independent homogeneous body. Weak ambiguities will be presented including both examples of incident scatters. The conditions on the scatterers at spatial infinity and their trapped mode bound-state structure will be given.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Fragile X-associated tremor/ataxia syndrome (FXTAS): Pathology and mechanisms

Since its discovery in 2001, our understanding of fragile X-associated tremor/ataxia syndrome (FXTAS) has undergone a remarkable transformation. Initially characterized rather narrowly as an adult-onset movement disorder, the definition of FXTAS is broadening; moreover, the disorder is now recognized as only one facet of a much broader clinical pleiotropy among children and adults who carry premutation alleles of the FMR1 gene. Furthermore, the intranuclear inclusions of FXTAS, once thought to be a CNS-specific marker of the disorder, are now known to be widely distributed in multiple non-CNS tissues; this observation fundamentally changes our concept of the disease, and may provide the basis for understanding the diverse medical problems associated with the premutation. Recent work on the pathogenic mechanisms underlying FXTAS indicates that the origins of the late-onset neurodegenerative disorder actually lie in early development, raising the likelihood that all forms of clinical involvement among premutation carriers have a common underlying mechanistic basis. There has also been great progress in our understanding of the triggering event(s) in FXTAS pathogenesis, which is now thought to involve sequestration of one or more nuclear proteins involved with microRNA biogenesis. Moreover, there is mounting evidence that mitochondrial dysregulation contributes to the decreased cell function and loss of viability, evident in mice even during the neonatal period. Taken together, these recent findings offer hope for early interventions for FXTAS, well before the onset of overt disease, and for the treatment of other forms of clinical involvement among premutation carriers.
Characteristics of Evaluated Childhood Agricultural Safety Interventions

The goal of this paper was to examine interventions focused on childhood agricultural safety since the last general assessment conducted for the 2001 Summit on Childhood Agricultural Injury Prevention. The objectives were to identify the strengths and weaknesses of the knowledge base and identify challenges to and recommendations for improving programs, interventions, and policies. Published literature from 2001 to 2009 was identified and reviewed. We found 26 studies evaluating the effectiveness of interventions aimed at preventing farm-related injuries to children. There were mixed results in a number of studies, weak methods in many, and a lack of randomized controlled trials, in particular. Most interventions focused on the individual level of the socio ecological model and only on education as a strategy, with behavior change and knowledge acquisition as the objectives. Although more studies have been published in recent years, the quality of the research and intervention design has not necessarily improved. Based upon this review, key recommendations for future childhood agricultural safety interventions are proposed.
Effects of peptide chain length on the gas-phase proton transfer properties of doubly-protonated ions from bradykinin and its N-terminal fragment peptides

Abstract Proton transfer properties were studied for doubly-protonated ions from bradykinin and seven smaller peptides whose sequences have C-terminal residues successively removed from bradykinin. Ions were generated by electrospray ionization (ESI) and their deprotonation reactions were investigated in a Fourier transform ion cyclotron resonance mass spectrometer. Sustained off-resonance irradiation (SORI)-collision-induced dissociation (CID) was used to obtain information on sites of protonation, while molecular dynamics calculations provided information on peptide ion conformations and Coulomb energies. As the number of amino acid residues decreases the peptide ions undergo proton transfer more readily. Apparent gas-phase acidities (GA app s), for the doubly-protonated ions decreased as the peptide size decreased, with values spanning the range of 225.8±4.2 kcal/mol for the nonapeptide bradykinin to 196.6±4.4 kcal/mol for the tripeptide Arg 1 Pro 2 Pro 3 . The magnitude of the drop in GA app as a residue was removed varied from 10.9 kcal/mol for removal of the highly basic Arg 9 to 0 kcal/mol for removal of Phe 8 (whose phenylalanine ring juts away from the peptide backbone and does not participate in hydrogen bonding). Hydrogen bonding in the modeled structures decreased as the peptide chain length decreased. The lowest energy structure for doubly-protonated bradykinin contained nine hydrogen bonds, while only one hydrogen bond was found for the tripeptide ions. In addition, the tripeptide ions had an extended structure, while the larger peptide ions were compact. There is no single reason that the peptide ions become more acidic (i.e., more reactive to proton transfer) as the peptide chain length is decreased. Depending upon the situation, factors that play a role in the proton transfer reactivity include intrinsic basicity of the protonation sites, intramolecular hydrogen bonding (particularly involving the protonated residue), Coulombic repulsion of charge sites, and conformational considerations such as accessibility/shielding of the protonation site.
Flexural-torsional buckling of fiber-reinforced plastic composite cantilever I-beams

Abstract A combined analytical and experimental study of flexural–torsional buckling of pultruded fiber-reinforced plastic (FRP) composite cantilever I-beams is presented. An energy method based on nonlinear plate theory is developed for instability of FRP I-beam, and the formulation includes shear effect and bending–twisting coupling. Three different types of buckling mode shape functions of transcendental function, polynomial function, and half simply supported beam function, which all satisfy the cantilever beam boundary conditions, are used to obtain the eigenvalue solution, and their accuracy in the analysis are investigated in relation to finite element results. Four different geometries of FRP I-beams with cantilever beam configurations and with varying span lengths are experimentally tested under tip loads to evaluate their flexural–torsional buckling response. The loads are applied at the centroid of the tip cross-sections, and the critical buckling loads are obtained by gradually adding weight onto a loading platform. A good agreement among the proposed analytical solutions, experimental testing, and finite element method is obtained, and simplified explicit formulas for flexural–torsional buckling of cantilever beams with applied load at the centroid of the cross-section are developed. The effects of vertical load position through the cross-section, fiber orientation and fiber volume fraction on buckling behavior are also studied. The proposed analytical solutions can be used to predict the flexural–torsional buckling loads of FRP cantilever beams and to formulate simplified design equations.
Teaching about Islam in Secondary Schools: Curricular and Pedagogical Considerations

Current demographic trends are contributing to a rapid increase in religious, racial, and ethnic diversity in the United States. This article provides a rationale for teaching about religious diversity, particularly Islam, in public schools and the vital role religion has played in American history. The article provides readers with important information regarding pedagogical and curricular issues related to teaching about Islam in social studies courses and information on how teachers can establish positive relationships with Muslim students by understanding the requirements and core beliefs of Islam.
Regiocontrolled Synthesis of Carbocycle-Fused Indoles via Arylation of Silyl Enol Ethers with o-Nitrophenylphenyliodonium Fluoride

A new, regiocontrolled synthesis of carbocycle-fused indoles has been developed. The two-step procedure involves first the regiospecific arylation of silyl enol ethers with o-nitrophenylphenyliodonium fluoride (1). Reduction of the nitro group on the aromatic ring with TiCl3 followed by spontaneous condensation of the aniline with the ketone then affords the indole products.
Near-optimal linear-time codes for unique decoding and new list-decodable codes over smaller alphabets

We present an explicit construction of linear-time encodable and decodable codes of rate r which can correct a fraction (1 —re)/2 of errors over an alphabet of constant size depending only on e, for every 0 r 0. The error-correction performance of these codes is optimal as seen by the Singleton bound (these are "near-MDS" codes). Such near-MDS linear-time codes were known for the decoding from erasures [2]; our construction generalizes this to handle errors as well. Concatenating these codes with good, constant-sized binary codes gives a construction of linear-time binary codes which meet the so-called "Zyablov bound". In a nutshell, our results match the performance of the previously known explicit constructions of codes that had polynomial time encoding and decoding, but in addition have linear time encoding and decoding algorithms.We also obtain some results for list decoding targeted at the situation when the fraction of errors is very large, namely (1—e) for an arbitrarily small constant e > 0. The previously known constructions of such codes of good rate over constant-sized alphabets either used algebraic-geometric codes and thus suffered from complicated constructions and slow decoding, or as in the recent work of the authors [9], had fast encoding/decoding, but suffered from an alphabet size that was exponential in 1/e. We present two constructions of such codes with rate close to Ω(e2) over an alphabet of size quasi-polynomial in 1/e. One of the constructions, at the expense of a slight worsening of the rate, can achieve an alphabet size which is polynomial in 1/e. It also yields constructions of codes for list decoding from erasures which achieve new trade-offs. In particular, we construct codes of rate close to the optimal Ω(e) rate which can be efficiently list decoded from a fraction (1—e) of erasures.
Chromosome 18 aneuploidy: Anatomical variations observed in cases of full and mosaic trisomy 18 and a case of deletion of the short arm of chromosome 18

Cases of full and mosaic trisomy 18 and a body of an infant with the 18p-syndrome were dissected in detail to compare the anatomical variations associated with these 3 chromosome imbalances involving autosome 18. The types and numbers of morphologic variations present in both the full and mosaic trisomy 18 bodies were similar to the types and numbers of variations seen in all other cases of full trisomy 18 that have been studied by gross dissection. Apart from an atrial septal defect, the body of the infant with the 18p- imbalance showed only 2 striking defects: 1) deficiencies of the levator palpebrae superioris muscle of the upper eyelid, and 2) absence of the ligament of the head of the femur. The first variation provides a morphologic basis to explain the ptosis which is observed frequently in affected individuals. Absence of the ligament of the head of the femur may be a factor contributing to congenital dislocation of the hip, which is reported occasionally in affected individuals. In addition to providing more detailed information about the phenotype of individual aneuploidy syndromes, studies of cases of different imbalances of single autosomes may provide additional insights about the genotype/phenotype relationships of specific chromosome segments.
L 1 adaptive controller for nonlinear time-varying reference systems

Abstract This paper considers uncertain time-varying nonlinear affine-in-control systems and presents the L 1 adaptive controller for the case when the performance specifications are defined via a given time-varying nonlinear system. The L 1 adaptive controller ensures that the nonlinear, affine-in-control, uncertain system follows its ideal nonlinear model during the transient and steady-state, if the adaptation gain is selected sufficiently large and the bandwidth of the low-pass filter in the L 1 adaptive control architecture is adjusted appropriately.
Inhibitory action of SR33557 on L-type calcium current in single ventricular myocytes of rat.

Abstract 1. The effect of SR33557 on L-type Ca2+ currents in rat ventricular myocytes was investigated by use of the whole-cell patch-clamp technique. 2. SR33557 inhibited Ca2+ current (ICa) in a concentration-dependent manner without change in the current-voltage relationship. 3. The inhibitory effect of SR33557 on ICa was dependent on the holding potential (Vh). The IC50 values were estimated to be 2.2 x 10(-8) M at Vh = -50 mV and 9.0 x 10(-6) M at Vh = -80 mV. SR33557 (10(-7) M) shifted the steady state inactivation curve of ICa toward more negative potentials. Thus, the affinity of the drug for inactivated channels was considerably higher than for resting channels. 4. Blockade of ICa by SR33557 was both tonic and use-dependent. 5. The time constant of onset of block was 36.4 s at -50 mV and 41.9 +/- 11.1 s at -40 mV. 6. The time course of unblock was voltage-dependent. The time constant declined from 400.7 +/- 68.1 is at -50 mV to 5.2 +/- 1.2 s at -80 mV. 7. The rate of block of ICa was related to the number of openings per unit time and to the amount of time spent depolarized. The affinity of drug for open channels was considered to be similar to that for inactivated channels. 8. These results suggest that SR33557 inhibits L-type Ca2+ current through binding to both open and inactivated channels in rat ventricular myocytes.
Technical solutions to the problem of reducing patient dosage

One of the greatest challenges existing today in the field of radiology is the development of equipment and techniques which will permit an accurate diagnosis and at the same time assure that the patient is subjected to the minimum radiation theoretically needed to accomplish that diagnosis. It is the purpose of this paper to discuss the present knowledge concerning what constitutes the minimum dosage and the means available either now or in the not too distant future to produce a diagnostic image utilizing this minimum dosage.
Genetic Basis of Antifungal Drug Resistance.

Antifungal resistance caused by mutations of the drug target, overexpression of the drug target, and drug efflux by the upregulation of transporters is increasingly common. Recently our understanding of fungal drug resistance has been advanced by the identification of three key transcriptional regulators of resistance: Tac1p, Upc2p, and Mrr1p. The discovery of hyperactive variants of these regulators in resistant clinical isolates confirms the importance of transcriptional regulation in the development of antifungal resistance. Alternative mechanisms of drug resistance, including aneuploidy and biofilm formation, have recently been documented in fungi, as well as the phenomenon of drug tolerance. Characterization of the transcriptional regulation of fungal drug resistance and the identification of novel mechanisms of resistance has implications for current therapy and for the development of future antifungal drugs.
Prinz's Problematic Proxytypes

Jesse Prinz has argued that a proxy type theory of concepts provides what he calls the ‘intentionality’ and ‘cognitive content’ desiderata better than any current competitor, and that the hybrid nature of proxytypes allows his theory to combine the informational component of informational atomism with the view that concepts are semantically structured entities. In response, I argue that the hybrid character of proxytypes, far from delivering the advantages Prinz claims, generates a threatening dilemma: either his theory is novel but fails to deliver the intentionality and cognitive content desiderata, or it delivers these desiderata but is not novel.
The intraluminal distribution of 15-μ-diameter carbonized microspheres within arterial microvessels as determined by vital microscopy of the golden hamster cheek pouch ☆

Abstract An assumption inherent in the use of microspheres for measuring regional blood flow is that microspheres distribute uniformly with blood. Published studies suggest that carbonized microspheres, 15–80 μm in diameter, concentrate centripetally in blood flowing through medium-size arteries. The intraluminal distribution of carbonized microspheres within blood flowing through arterial microvessels is not known. To study this problem, the passage of 15-μm-diameter, carbonized microspheres through the arterial vasculature of the golden hamster cheek pouch was cinefilmed. The trajectories of 800 microspheres flowing through 24 vessel segments in 14 different golden hamsters ( Mesocricetus auratus ) were tabulated. The mean diameter of the observed arterial vessels was 65.2 ± 13.7 (SD) μm. Carbonized microspheres did not distribute homogeneously across the available lumen of the observed microarteries. Comparison of the experimentally determined microsphere distribution against a null hypothesis of a homogeneous density distribution showed a greater than expected concentration of microspheres at the periphery of the available lumen and a less than expected percentage at its center. This disparity was present whether a blunt velocity flow profile or a parabolic velocity profile was convoluted with the density distribution. If flow approximates the parabolic velocity profile, microspheres become markedly underrepresented at the center of the vessel and overrepresented at its periphery. The greater than expected centrifugal distribution of microspheres was related neither to vessl diameter nor to the microsphere velocities studied. If one assumes that erythrocytes are evenly distributed throughout the available arterial lumen (with the exception of a cell-free zone at the periphery), then 15-μm-diameter carbonized microspheres significantly underrepresent the central concentration of erythrocytes and overrepresent the concentration of red blood cells at the microarterial periphery.
Fusions between Epstein-Barr viral nuclear antigen-1 of Epstein-Barr virus and the large T-antigen of simian virus 40 replicate their cognate origins.

Epstein-Barr viral nuclear antigen-1 (EBNA-1) is required for the stable replication of plasmids that containoriP, the origin of DNA synthesis used during the latent phase of the Epstein-Barr virus life cycle. EBNA-1 acts post-synthetically through unknown mechanisms to facilitate the continued synthesis of oriP plasmids in ensuing S phases. In contrast to viral replicons such as that of SV40, DNA synthesis of oriP is restricted to a single round during each cell cycle. Large T-antigen of SV40 is a DNA helicase and activates the synthesis of SV40 DNA by recruiting cellular proteins required for DNA synthesis to the origin of SV40. Using fusion proteins of EBNA-1 and large T-antigen, we tested whether tethering large T-antigen tooriP is sufficient to initiate multiple rounds of DNA synthesis from oriP during each cell cycle. We report here that, although these fusion proteins retain the biological activities of both EBNA-1 and large T-antigen, their constituent proteins do not confer the properties of one on the other. Thus, it is not possible to subvert the cellular controls that restrict DNA synthesis fromoriP to a single round per cell cycle. These results also provide insights into architectural constraints at oriP and at the SV40 ori.
Interaction of potassium dichromate with the nephrotoxins, mercuric chloride and citrinin.

Potassium dichromate enhanced the effects of mercuric chloride or citrinin on renal slice transport of the organic ions p-aminohippurate (PAH) and tetraethylammonium (TEA) under certain experimental conditions. At the doses employed and times studied no effects, or only minimal effects, were observed on renal slice transport when the toxins were tested individually. Potassium dichromate (10 mg/kg) administered subcutaneously (s.c.) in combination with mercuric chloride (4 mg/kg, s.c.) or citrinin 35 or 55 mg/kg administered intraperitoneally (i.p.), resulted in a marked depression of organic ion transport. Similarly, the addition of potassium dichromate to fresh renal cortex slices in combination with mercuric chloride, enhanced the mercuric chloride-induced reduction of transport. No other interactions were observed under in vitro conditions.
Special safety considerations in preparation of technetium Tc-99m DTPA for cerebrospinal fluid–related imaging procedures

Abstract Objective To review special safety considerations in the preparation of technetium 99m (Tc-99m) diethylenetriaminepentaacetic acid (DTPA; generic name, pentetate) for cerebrospinal fluid (CSF)–related imaging procedures. Data sources Review of practices and results at one institution supplemented with findings and recommendations from the literature. Literature searches were conducted via Medline/PubMed using the following terms: Tc-99m DTPA/pentetate, CSF, cisternography, intrathecal, and adverse reactions. The author's own files were also searched for articles (e.g., in newsletters) not indexed by Medline/PubMed. Study selection Articles considered appropriate for review included all human research studies, reviews, case reports, abstracts, and letters published in English on Tc-99m DTPA use in CSF-related imaging procedures, especially with regard to safety or adverse reactions. Data extraction All information related to safety precautions and adverse reactions associated with Tc-99m DTPA injected intrathecally or otherwise used for CSF-related imaging procedures were considered. Data synthesis 18 years’ experience in one institution was reviewed with the added perspective of literature findings and recommendations. Conclusion With proper attention to safety considerations, Tc-99m DTPA can be safely used in CSF-related imaging procedures.
MECHANISMS OF NITROUS OXIDE PRODUCTION IN SOILS

Recent research by atmospheric scientists has created international concern that increased use of nitrogen fertilizers to aid world food production will increase emission of nitrous oxide (N2O) from soils to the atmosphere via denitrification of fertilizer-derived nitrate and thereby promote destruction of the stratospheric ozone layer protecting the biosphere from biologically harmful ultraviolet radiation from the sun (see Council for Agricultural Science and Technology, 1976; McElroy et al., 1977; Crutzen and Ehhalt, 1977; Liu et al., 1977). This threat has stimulated extensive research on factors affecting N2O emissions from soils and the effects of nitrogen fertilizers on these emissions. The purpose of this article is to report recent research in our laboratory relating to the mechanisms of N2O production in soils.
Transcendence of the Ego (The Non-Existent Knight)

I exist, but I am not a thing among things; X exists if and only if there is something such that it = X. This is consistent, and it is a view that can be supported. Calvino's novel The Non-Existent Knight can be read so as to illustrate this view. But what is my relation to the things there are if I am not identical with any of them - things such as my arms, my garden, the city I live in? I name this the Gurduloo problem, after the Knight's page. This relation must be one that admits of degrees; I suggest that we say that I manifest myself through the things thus associated with me. Several pseudo-problems, pertaining to volitional action, supervenience, observability, and the emergence of consciousness, dissolve upon inspection.
Probing spatial correlations with nanoscale two-contact tunneling.

Interference effects on the transport through two localized tunnel junctions on the surface of a well-grounded sample reveal intrinsic spatial correlations characteristic of the uncoupled sample. Differential conductances of the two-junction probe are related to the spatial correlations of both normal and superconducting samples. For a superconducting sample the gap anisotropy strongly affects the results. This may serve as a sensitive probe of the order parameter in high-temperature superconductors.
Canonical forms under dynamic compensation and zero structure at infinity

The exact relation between the interactor and the Hermite normal form of a system P is established and their relation to state feedback compensation is shown. The Smith-McMillan form at infinity of P is then derived from these canonical forms.
PARASITES WITH BENEFITS

![Figure][1] Throughout evolution, plants and insects have exploited each other in mutually beneficial relationships where two or more parties benefit from essential ecological interactions. For example, insects act as plant pollinators while plants act as hosts providing food or housing for
APPLICATION OF PROBABILISTIC METHODS TO WEAPON RELIABILITY ASSESSMENT

Southwest Research Institute in collaboration with engineers at Los Alamos National Laboratory (LANL) are currently developing capabilities to provide reliability-based structural evaluation techniques for performing weapon component and system reliability assessments in support of eventual weapon certification by analysis. Focus herein is placed on two problems recently studied: 1) The uncertain structural response of an explosive actuated valve-piston assembly, and 2) the quasi-static collapse response of a spherical shell. The probabilistic dynamic response of the piston is evaluated through the coupling of the probabilistic software NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) 2 with the non-linear structural dynamics code, ABAQUS/Explicit 3 . The probabilistic model includes variations in piston mass and geometry, and mechanical properties, such as Young's Modulus, yield strength, and flow characteristics. The probabilistic response of the shell is evaluated through the coupling of the NESSUS software and the explicit dynamic code DYNA3D 5 . Variations in geometric shape parameters and material properties are considered. Nomenclature
Staphylococcal Superantigens Cause Lethal Pulmonary Disease in Rabbits

Background The Centers for Disease Control and Prevention (CDC) and others reported that methicillin-resistant S. aureus (MRSA) are significant causes of serious human infections, including pulmonary illnesses. We investigated the role played by superantigens in lung-associated lethal illness in rabbits. Methods A rabbit model was established to investigate the potential role played by superantigens, staphylococcal enterotoxin B (SEB), staphylococcal enterotoxin C (SEC), and toxic shock syndrome toxin-1 (TSST-1). Rabbits received intrabronchial community-associated (CA) MRSA strains USA200 (TSST-1(+)), MW2 (SEC(+)), c99-529 (SEB(+)), or purified superantigens. Some rabbits were preimmunized against superantigens or treated with soluble high-affinity T cell receptors (Vβ-TCR) to neutralize SEB and then challenged intrabronchially with CA-MRSA or superantigens. Results Rabbits challenged with CA-MRSA or superantigens developed fatal, pulmonary illnesses. Animals preimmunized against purified superantigens, or treated passively with Vβ-TCRs and then challenged with CA-MRSA or superantigens, survived. Lung histological analysis indicated that nonimmune animals developed lesions consistent with necrotizing pneumonia after challenge with CA-MRSA or purified superantigens. Superantigen-immune animals or animals treated with soluble Vβ-TCRs did not develop pulmonary lesions. Conclusions Superantigens contribute to lethal pulmonary illnesses due to CA-MRSA; preexisting immunity to superantigens prevents lethality. Administration of high-affinity Vβ-TCR with specificity for SEB to nonimmune animals protects from lethal pulmonary illness resulting from SEB(+) CA-MRSA and SEB.
40-year-old man with nausea and vomiting "found down".

A 40-year-old man with a history of prior closed head injury, insulin-dependent diabetes mellitus type 2, and nicotine dependence was evaluated at Saint Marys Hospital, a Mayo Clinic–affiliated hospital in Rochester, MN, after being found unconscious at his home.
Coal quality analysis techniques using artificial neural network techniques

Summary form only given. The paper describes the design and development of an online hybrid intelligent system from which coal quality can be determined interactively as an aid to steam power plant operators. The hybrid model combines neural networks with expert systems. The neural net module predicts the online performance of a boiler and its health for various coal blends and load conditions. The expert system deciphers the neural network model results and then diagnoses the situation. If coal quality conditions change, then the expert system alerts the operator and reports any impending consequences and performance degradation. The system then suggests one or more corrective actions to the steam power plant operator.
The performance of “Virtual Phase” CCDs as detectors of minimum-ionizing particles

Abstract The Texas Instruments “Virtual Phase” CCD has been the basis of an ambitious design for a precision vertex detector to be used at the Stanford Linear Collider. The performance of this chip shows promise for future use in electron linear colliders. Experimental results are reported in addition to description of the electronic readout and preliminary mechanical design.
Analysis of detection systems for outdoor chemical or biological attacks

This paper presents Sandia National Laboratories' Outdoor Weapons of Mass Destruction Decision Analysis Center (OutDAC) and, through an example case study, derives lessons for its use. This tool, related to similar capabilities at Sandia, can be used to determine functional requirements for a detection system of aerosol-released threats outdoors. Essential components of OutDAC are a population database, a meteorological dataset, an atmospheric transport and dispersion model and an optimization toolkit. Detector placement is done through optimization against a library of hypothesized attack scenarios by minimizing either the mean or value-at-risk of undetected infections. These scenarios are the product of a Monte Carlo simulation intended to characterize the uncertainty associated with the threat. An example case study illustrates that Monte Carlo convergence is dependent on the statistic of interest. Furthermore, the quality of the detector placement optimization may be tied to the convergence level of the Monte Carlo simulation.