cssi/SciSciGPT-SciSciNet huggingface dataset:
Green Cone Opsin and Rhodopsin Regulation by CNTF and Staurosporine in Cultured Chick Photoreceptors

Purpose To investigate the regulation of visual pigment expression in chick embryo photoreceptor cells by ciliary neurotrophic factor (CNTF), and by the protein kinase inhibitor staurosporine. Methods Embryonic day (ED) 8 chick embryo retinal cells were dissociated and cultured at low densities for 3 days, either in control medium or in medium supplemented with CNTF or staurosporine. The cultures were analyzed by immunocytochemistry with the monoclonal antibody Rho4D2, which recognizes chicken rhodopsin and green cone pigment, and by reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis to investigate visual pigment expression at the mRNA level. Results CNTF increased the number of Rho4D2-immunoreactive photoreceptors in retinal cell cultures, in agreement with previous reports. RT-PCR and Northern blot analysis, however, showed that rhodopsin mRNA was undetectable in both control and CNTF-treated cultures but that CNTF induced significant increases in mRNA levels for the green cone pigment. Staurosporine-treated cultures also had more Rho4D2-immunoreactive cells than control cultures, but this increase was accompanied by induction of rhodopsin expression, with concomitant decreases in levels of green cone pigment mRNA. No significant differences were found between CNTF- or staurosporine-treated cultures and the corresponding control cultures regarding the red cone pigment, which was expressed in all cases, and the blue and violet pigments, which were not detected in any of the samples. Conclusions The results suggest that multiple regulatory systems control visual pigment expression during differentiation of chick embryo photoreceptor cells. CNTF appears to stimulate specifically the differentiation of green cones, without the previously suggested effects on the differentiation of rod photoreceptors in ED 8 chick retinal cultures.
Kernels and Submodels of Deep Belief Networks

We study the mixtures of factorizing probability distributions represented as visible marginal distributions in stochastic layered networks. We take the perspective of kernel transitions of distributions, which gives a unified picture of distributed representations arising from Deep Belief Networks (DBN) and other networks without lateral connections. We describe combinatorial and geometric properties of the set of kernels and products of kernels realizable by DBNs as the network parameters vary. We describe explicit classes of probability distributions, including exponential families, that can be learned by DBNs. We use these submodels to bound the maximal and the expected Kullback-Leibler approximation errors of DBNs from above depending on the number of hidden layers and units that they contain.
Autonomous Robotic Mining Excavation Using Fuzzy Logic and Neural Networks

This article describes our initial investigation into using neural networks and fuzzy behaviors for autonomous excavation control of a robotic front-end-loader-type mining machine. To utilize the experience and expertise from skilled human operators, a behavior-control approach based on fuzzy logic is developed. Nine typical behavior programs for general excavation tasks are constructed and implemented with fuzzy logic rules. Two neural networks are built to assess excavation situations and then select the corresponding behavior programs based on force/torque feedback data. Simple strategies for self-evaluation and fusion of fuzzy behaviors are presented. To verify the proposed approach, laboratory experiments are conducted using a PUMA 560 robot arm, a Zebra force/torque sensor, and a SUN workstation. Experimental results indicate that fuzzy behaviors are capable of reacting to unpredicted events during the excavation process and can complete the desired excavation goals successfully.
Effect of the degree of effort on exercise echocardiography for the detection of restenosis after coronary artery angioplasty.

Abstract To determine whether the accuracy of exercise echocardiography is affected by the degree of effort during exercise, we examined 101 patients who had 6 months earlier undergone successful coronary artery angioplasty, with resting and immediate postexercise echocardiography and same-day coronary angiography. A positive exercise echocardiographic response was defined as the development of a new or worsening wall motion abnormality postexercise, compared with resting wall motion. Significant coronary disease (>50% diameter stenosis) was present in 48 patients, 38 of whom had single-vessel disease and 10 of whom had two-vessel disease. Exercise echocardiography correctly identified 32 patients with significant disease (sensitivity 67%) and 44 patients without significant disease (specificity 83%). The effect of the degree of exercise effort on the sensitivity and specificity of the test was evaluated by three criteria; (1) the percentage of maximum predicted heart rate (MHR), (2) the duration of exercise (DUR), and (3) the double product (DP). To determine the influence of the degree of effort upon sensitivity and specificity, the effort criteria were compared between patients with true positive (TP) tests to those with false negative tests (FN), and in patients with true negative (TN) tests compared with those with false positive (FP) tests. No significant differences were detected in MHR, DUR, or DP between TP versus FN patients or between TN versus FP patients. These results indicate that for symptom-limited exercise echocardiography in postangioplasty patients, neither sensitivity nor specificity is significantly affected by the degree of effort during exercise.
Modelling of melt motion in a Czochralski crystal puller with an axial magnetic field

Abstract The use of matched asymptotic expansions provide analytical solutions for the bulk flow in a Czochralski crystal puller in a strong axial magnetic field. Treating the crystal as a slight electrical conductor alters the radial and axial flows driven by centrifugal pumping. The motion due to buoyancy and thermocapillarity are found by considering the temperature as a known function and solving the non-linear heat equation numerically for different magnetic field strengths and melt depths. This note presents a summary of the analysis and results that are detailed in two papers.
The palynology of Upper Pleistocene and Holocene sediments from the eastern shoreline and Central Depression of St. Catherines Island, Georgia, USA

Sediment samples from the Hoke's Landing area of St. Catherines Island, Georgia, were analyzed for their pollen and spore contents, and were further analyzed for their clay mineralogy and time of deposition. Samples were retrieved from a core collected in July, 2013, and were recovered from a site lying near an early-twentieth-century oyster boiler on the eastern side of the island, the Hoke's Landing oyster boiler. The continuous core was more than 4.5 m long, representing one of the longest continuous cores collected on the island. Palynological and radiocarbon analyses provide significant information concerning the Late Pleistocene and Holocene evolution of the island; one of the most ancient finite radiocarbon ages (31,990 ± 230 years BP) came from the Hoke's Landing site. Clay analyses indicate the presence of montmorillonite, kaolinite and illite, indicating sediment contributions from marine and terrestrial environments. Palynological data show that the freshwater fern Woodwardia grew in abundance ...
Shared signaling systems in myeloid cell-mediated muscle regeneration

Much of the focus in muscle regeneration has been placed on the identification and delivery of stem cells to promote regenerative capacity. As those efforts have advanced, we have learned that complex features of the microenvironment in which regeneration occurs can determine success or failure. The immune system is an important contributor to that complexity and can determine the extent to which muscle regeneration succeeds. Immune cells of the myeloid lineage play major regulatory roles in tissue regeneration through two general, inductive mechanisms: instructive mechanisms that act directly on muscle cells; and permissive mechanisms that act indirectly to influence regeneration by modulating angiogenesis and fibrosis. In this article, recent discoveries that identify inductive actions of specific populations of myeloid cells on muscle regeneration are presented, with an emphasis on how processes in muscle and myeloid cells are co-regulated.
Intraperitoneal gastric fixation of hiatal hernia.

Abstract Nineteen consecutive hiatal hernia repairs have been performed utilizing crural approximation, selective vagotomy, pyloroplasty, and gastrostomy with traction on the lesser curvature of the stomach to maintain reduction of the esophagocardiac junction. Fifteen patients have become asymptomatic, and three have had a fair result with mild persistent symptoms.
Protecting fragile lands: New reasons to tackle old problems

Abstract Increasing peasant access to arable land can have a positive environmental impact. Past efforts to expand the peasantry's land base through redistributive land reform and colonization generally lacked an environmental dimension and often intensified resource degradation. Most agrarian reform interventions were limited to properties with marginal agricultural potential, while colonization (directed and spontaneous) triggered extensive deforestation and resource degradation. Programs to increase the peasantry's access to arable land can be targeted to draw peasant farmers away from steep slopes in critical watersheds and to reduce their migration to specified lowland forests. The programs reviewed here depend on strategic interventions to supersede current market imperfections limiting peasant access to large arable properties.
Low level incorporation of tritiated thymidine into the nuclear DNA of Purkinje neurons of adult mice.

Adult mice were pulse labeled with tritiated thymidine [3H]TdR and killed 9 hr later. A low level incorporation of [3H]TdR into the nuclear DNA of Purkinje neurons was found in autoradiographs. Enzymatic digestions with DNase and with RNase in combination with autoradiographic grain counts indicate that a portion of nuclear DNA is not stable in the Purkinje nucleus. These results are discussed in light of reports of the stable nature of DNA in Purkinje neurons of adult mice.
Older Women's Sexuality

An exploratory study was conducted to investigate clinical observations of older women's interests in sexuality, Interviews with 10 high functioning women with an average age of 68.8 years revealed that while incidence of sexuality has declined, their overall satisfaction with sex has stayed the same or increased from when they were younger. The lack of a sexual partner or illness of a spouse were typical reasons reported for the decline in sexual activity. A descriptive summary of these interviews is followed by a discussion of the implications for therapy. Several case examples are used to illustrate the benefits of initiating discussions of sexuality with older women in therapy.
Molecular adsorption and growth of n-butane adlayers on Pt(1 1 1)

The molecular adsorption of n-butane and the growth of n-butane adlayers on Pt(1 1 1) was investigated using molecular beam techniques, temperature-programmed desorption (TPD) and low-energy electron diffraction (LEED). It is found that as the surface coverage of n-butane increases, structural changes occur in the adlayer at surface temperatures near 98 K that are accompanied by changes in the binding energy and mobility of the adsorbed species. The film growth process can be divided into four distinct coverage regimes. At low coverages (0 < 0.14 ML, where 1 ML is defined as one butane molecule per Pt atom) a disordered monolayer forms in which the butane molecules prefer to lie parallel to the surface in order to minimize their binding energy. At coverages from 0.14 to 0.20 ML, ordered regions develop within the monolayer in which the butane molecules also lie parallel to the surface. The binding energy in the ordered phase is lower than that in the disordered phase due to repulsive intermolecular interactions. A more densely-packed ordered phase begins to form at 98 K after the low-coverage ordered phase saturates at 0.20 ML. The experimental results suggest that the n-butane molecules tilt away from the surface in the high-coverage ordered phase. Finally, a disordered second layer phase forms after the high coverage ordered phase saturates at 0.35 ML. The molecules in the second layer are very mobile at 98 K and rapidly diffuse to the edges of the beam spot. Interchange of molecules between the second layer and ordered monolayer is found to govern the net rate of second layer diffusion at surface temperatures less than 133 K. The adsorption probability of n-butane on Pt(1 1 1) continuously increases with increasing coverage, with no significant dependencies on the structure of the n-butane adlayer. This finding indicates that the long-range arrangements and molecular orientations of a mobile alkane adlayer have a negligible influence on the intrinsic adsorption dynamics, suggesting that the energy transfer processes that facilitate adsorption are highly localized.
Ultrastructure in frozen/etched saline solutions: on the internal cleansing of ice.

Seawater, with its 3.5% salt content, freezes into hexagonal ice (Ih) that encloses concentrated brine within its matrix. When unsubmerged sea ice reaches a certain height and temperature, the brine drains downward through narrow channels. This mechanism was now modeled by frozen 2−3.5% saline as investigated by cryo-etch high-resolution secondary electron microscopy. Thus, saline was either plunge-frozen in liquid ethane at −183 °C or else high-pressure frozen to −105 °C in 5−6 ms. Ice from a freshly exposed surface was then subjected to a high-vacuum sublimation (“etching”), a procedure that removes pure bulk ice in preference to ice from frozen hydrated salt. After chromium-coating the etched surface with a 2-nm film, the sample was examined by cryo-HRSEM. Granular icy “fences” were seen surrounding empty areas where amorphous ice had originally resided. Since the fences, about 1−2 μm high, survived the etching, it is likely that they consist of frozen brine. The presence of such fences suggests that, ...
ICRF heating of TFTR deuterium supershot plasmas in the 3He minority regime

The increased core electron temperature produced by ICRF heating of TFTR, D-T neutral-beam-heated supershot plasmas is expected to extend the alpha-particle slowing down time and hence enhance the central alpha-particle pressure. In preparation for the TFTR D-T operational phase, which started in late 1993, a series of experiments were conducted on TFTR to explore the effect of ICRF heating on the performance and stability of low-recycling, deuterium supershot plasmas in the 3He minority heating regime. The coupling of up to 7.4 MW of 47 MHz ICRF power to full size (R approximately 2.62 m, a approximately 0.96 m), 3He minority, deuterium supershots heated with up to 30 MW of deuterium neutral beam injection has resulted in a significant increase in core electron temperature ( Delta Te=3-4 keV). Simulations of equivalent D-T supershots predict that such ICRF heating should result in approximately a 60% increase in the alpha-particle slowing down time and an enhancement of about 30% in the central alpha pressure. Future experiments to be conducted at ICRF powers up to 12.5 MW during the upcoming TFTR D-T campaign may result in even greater enhancements in core alpha parameters. This paper presents results from experiments performed at an axial toroidal magnetic field of about 4.8 T, where the minority resonance was within 0.1-0.15 m of the plasma core. Combined ICRF and neutral beam heating powers in these experiments reached TFTR record levels of over 37 MW, which allowed an exploration of the power loading limits on the carbon limiter tiles. The plasma current was operated at 1.85 and 2.2 MA and sawtooth suppression was observed at the higher plasma current.
HPLC Separation and Characterization of Synthetic and Native Cytochrome C Derived Peptides

Abstract The use of HPLC for the characterization of peptides used in semisynthesis of cytochrome c is discussed. HPLC provided a convenient method for assessing the purity and structure of the peptides used. HPLC was also useful in monitoring the progress of solid phase peptide synthesis and in purifying the final product.
Compact Model Based Microfluidic Controller for Energy Efficient Thermal Management Using Pin-Fin Enhanced Micro Gap

Over-cooling of electronic devices and systems results in excess energy consumption, which can be reduced by closely linking cooling requirements with actual power dissipation. A thermal model-based flow rate controller for single phase liquid cooled three-dimensional (3D) stacked chips, using pin-fin enhanced micro gap was studied in this paper. A thermal compact model of a two-layer pin fin enhanced micro gap was developed, which ran 105 times faster than using full-field computational fluid dynamics/heat transfer (CFD/HT) method, with reasonable accuracy and spatial details. This was used in conjunction with a flow rate control strategy to provide the needed amount of liquid to cool the heat sources to the desired temperature range. An example case study shows that the estimated energy savings in pump power is about 27% compared with pumping fluid at a constant flow rate.Copyright © 2013 by ASME
Multivariate assessment of computer-analyzed corneal topographers

Methodological aspects of multivariate statistical models to describe and to assess data from computer-analyzed corneal topographers (CACT) are considered. The data generated by repeated curvature mappings of calibrated steel balls are discussed in detail with the objective of formulating the basic questions and suggesting directions to assess data from clinical applications of CACT. The interpretation of seemingly straightforward concepts such as accuracy and precision is revisited with the objective of understanding its meaning in future clinical and experimental applications of CACT. Some of the statistical problems related to the analysis of corneal astigmatism based on CACT data are also discussed.
Convex risk averse control design

In this paper, we show that for arbitrary stochastic linear dynamical systems, the problem of optimizing parameters of a feedback control policy can be cast as a convex optimization problem when a risk-averse objective (similar to LEQG) is used. The only restriction is a condition relating the control cost, risk factor and noise in the system. The resulting approach allows us to synthesize risk-averse controllers efficiently for finite horizon problems. For the standard quadratic costs in infinite horizon, the resulting problems become degenerate if the uncontrolled system is unstable. As an alternative, we propose using a discount-based approach that ensures that costs do not blow up. We show that the discount factor can effectively be used as a homotopy parameter to gradually synthesize stabilizing controllers for unstable systems. We also propose extensions where non-quadratic costs can be used for controller synthesis, and in this case, as long as the costs are bounded, the optimization problems are well-posed and have non-trivial solutions.
Existence and local stability of Pareto superior reaction function equilibria in discounted supergames

Abstract The existence of locally asymptotically stable subgame perfect reaction function equilibria (RFE) is demonstrated for a general class of n-player discounted supergames. Benefit denial, a fundamental identity of all subgame perfect equilibria defined on a convex range, is introduced and is the key to the equilibrium existence proof.
Tunable supramolecular networks via cis-trans metal–ligand isomerization

Using Monte Carlo simulations we studied the effect of cis-trans isomerization of 2 : 1 ligand–metal complexes on self-assembly and network formation of metallo-supramolecular polymers in a good solvent. Comparing two systems containing only cis- or trans- isomers, we found that in the oligomer-rich region the fraction of both 2 : 1 and 3 : 1 ligand–metal complexes is rather similar for both systems and as a result the average molecular weight and reversible network properties are also nearly the same. In the metal-rich region a larger fraction of cis-2 : 1 ligand–metal complexes results in a noticeably larger average molecular weight of associating polymers. Accordingly, the onset of formation of a reversible network containing cis-isomers occurs at a considerably lower oligomer number density and for a larger range of metal-to-oligomer ratios. The weight fraction of the network containing cis-isomers and its equilibrium elastic plateau modulus considerably exceeds that for the trans-isomer network, especially in the metal-rich region. We predict conditions when trans- to cis- isomerization can trigger the sol-network transition and/or result in a significant change in materials properties, such as molecular weight and especially elastic plateau modulus. We discuss the molecular mechanisms of network transformation upon cis-trans isomerization, which vary with metal-to-oligomer ratio and originate from different morphologies of the reversible network. These results demonstrate that the cis-trans isomerization of 2 : 1 ligand–metal complexes significantly affects the microscopic and macroscopic properties of the metallo-supramolecular polymers and could be used to design new types of smart materials.
Evaluation of Forages in the Laboratory. IV. Within and among Trial Variability of the Wisconsin Artificial Rumen Procedure

Summary Within and among trial variability of an artificial rumen procedure used for forage evaluation were estimated. Comparison of forages ground through a 40- or 60-mesh screen revealed that finer grinding increased in vitro digestibility of grasses and legumes but the digestibility of grasses was increased to a greater extent. No significant difference was found in the correlation of in vitro cellulose digestion and in vivo DDM due to fineness of grind. It was suggested that grinding be standardized within a laboratory. Fermentation periods of 18, 24, 30, and 48 hr all resulted in cellulose digestibilities significantly correlated with in vivo DDM. The correlation coefficients did not differ significantly. Day-to-day variation was significantly less for the 48-hr fermentation than for any of the shorter times. Alternate procedures involving either a flask or a beaker as the fermentation vessel did not yield different within or among trial variances. The beaker method has the advantage of eliminating transfers. The over-all variance and coefficient of variation of the Wisconsin artificial rumen procedure were 2.74 and 3.54% within day and 1.48 and 1.92% among days, respectively.
Thioalkylation of Meldrum's Acid with Dialdehydes. Isopropylidene cis-2-Hydroxy-6-phenylthiocyclohexane-1,1-dicarboxylate Derivatives

Abstract Reaction of Meldrum's acid, thiophenol and gluteraldehyde in aqueous acetonitrile with piperidine acetate affords a 70% yield of isopropylidene cis -2-hydroxy-6-phenylthiocyclohexane-1,1-dicarboxylate. The reaction is very general. It can be applied to dialdehydes derived in a many ways using many different thiols. © 1997 Elsevier Science Ltd.
Abstract 260: Identification of the role of linker histone H1 in estrogen receptor binding and activity

The activity of estrogen receptor (ER) in the nucleus is a highly dynamic process, which is tightly regulated by many factors. Among the molecules proposed to facilitate ER activity are proteasome components, chromatin-remodeling complexes, heat shock proteins and histones. Particularly the linker histone H1 seems important, as it is essential to the stability of the higher-order chromatin structure and has been associated with the regulation of gene expression for many years. Eleven linker histones have been identified in humans to date, differing in their timing of expression, extent of post-translational modification and affinity to DNA in chromatin. However, their exact function and ability to differentially affect gene expression are not as clearly understood. It seems probable that linker histones need to be removed, reduced in amount or somehow modified during transcription in order to allow access to the transcription machinery and that these processes are different for the different linker histone subtypes. Here we show that removal of linker histone H1 is a prerequisite for the full activation of ER-regulated target genes in ER positive breast cancer cells. This process is mediated through the activity of the cyclin-dependent kinase 2 (CDK2), which phosphorylates H1 in a hormone-dependent manner, and thereby loosens the interaction of the linker histone with DNA in chromatin. The extent of phosphorylation differs significantly between the different subtypes, suggesting a differential involvement of the H1s in ER-mediated gene expression. Collectively, our results show that H1 dissociation is required for ER-mediated gene expression in breast cancer and that the H1 subtypes may play distinct functional roles in the transcriptional regulation of ER target genes. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 260. doi:10.1158/1538-7445.AM2011-260
IDENTIFYING COLLISIONAL FAMILIES IN THE KUIPER BELT

The identification and characterization of numerous collisional families—clusters of bodies with a common collisional origin—in the asteroid belt has added greatly to the understanding of asteroid belt formation and evolution. More recent study has also led to an appreciation of physical processes that had previously been neglected (e.g., the Yarkovsky effect). Collisions have certainly played an important role in the evolution of the Kuiper Belt as well, though only one collisional family has been identified in that region to date, around the dwarf planet Haumea. In this paper, we combine insights into collisional families from numerical simulations with the current observational constraints on the dynamical structure of the Kuiper Belt to investigate the ideal sizes and locations for identifying collisional families. We find that larger progenitors (r ~ 500 km) result in more easily identifiable families, given the difficulty in identifying fragments of smaller progenitors in magnitude-limited surveys, despite their larger spread and less frequent occurrence. However, even these families do not stand out well from the background. Identifying families as statistical overdensities is much easier than characterizing families by distinguishing individual members from interlopers. Such identification seems promising, provided the background population is well known. In either case, families will also be much easier to study where the background population is small, i.e., at high inclinations. Overall, our results indicate that entirely different techniques for identifying families will be needed for the Kuiper Belt, and we provide some suggestions.
A film production course

Student demand is cited in addition to theoretical rationale to make a case for a practical film production course within a communication curriculum. A college level course is described with some applications to two‐year‐college and high school courses. Choice of equipment, equipment and processing costs, appropriate instructional films, filmed exercises for student projects, and a range of current textbooks are among the matters discussed.
Disseminated strongyloidiasis in an immunocompromised male

Antimicrobial Agents and Chemotherapy. American Society for Microbiology, Washington, DC. 33. Cammarata, S.K. et al. 2000. Linezolid versus cephalosporin therapy in the treatment of patients with communityacquired pneumonia: summary of two randomized trials. Eur. Respir. J. 16(Suppl. 3): 139S. 34. Cammarata, S.K. et al. 2000. Linezolid is superior to cephalosporins in treatment of patients with bacteremic Streptococcus pneumoniae communityacquired pneumonia.. Am. J. Respir. Crit. Care Med. 161(Suppl. 2): A654. 35. Stevens, D.L. et al. 2000. Randomized comparison of linezolid (PNU-100766) versus oxacillin-dicloxacillin for treatment of complicated skin and soft tissue infections. Antimicrob. Agents Chemother. 44:3408-3413. 36. Mangano, R. et al. 2000. Comparison of linezolid and flucoloxacillin in the treatment of complicated skin infections: analysis of European and South African patients in a regional phase III trial. Third International Meeting on the Therapy of Infections, Florence, Italy. 37. Melzer, M., D. Goldsmith, and W. Gransden. 2000. Successful treatment of vertebral osteomyelitis with linezolid in a patient receiving hemodialysis with persistent methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus bacteremias. Clin. Infect. Dis. 31:208-209. 38. Stalker, D.J., C.P. Wajszczuk, and D.H. Batts. 1997. Linezolid safety, tolerance, and pharmacokinetics following oral dosing twice daily for 14.5 days, abstr. A115. In Program and Abstracts of the 40th Interscienee Conference on Antimicrobial Agents and Chemotherapy. American Society for Microbiology, Washington, DC. 39. NCCLS. 2002. Performance standards for antimicrobial susceptibility testing-12th informational supplement. M 100S12. NCCLS. Wayne, PA. 40. Bouza, E. and E Mufioz. 2001. Linezolid: pharmacokinetic characteristics and clinical studies. Clin. Microbiol. Infect. 7(Suppl. 4):75-82. 41. Pharmacia and UpJohn Company. 2000. Linezolid prescribing information. Pharmacia and Up John Company, Kalamazoo, MI. 42. Cammarata, S.K. et al. 2000. Incidence of Clostridium difficile-related complications during clinical trials of linezolid, an oxazolidinone, abstr. 947. In Program and Abstracts of the 40th Interscience Conference on Antimicrobial Agents and Chemotherapy. American Society for Microbiology, Washington, DC. 43. Zurenko, G.E. 2000. Oxazolidinones. Linezolid and beyond, abstr. 637. In Program and Abstracts of the 40th Interscience Conference on Antimicrobial Agents and Chemotherapy. American Society for Microbiology, Washington, DC.
Contrast echocardiography is superior to tissue harmonics for assessment of left ventricular function in mechanically ventilated patients

Abstract Background Assessment of left ventricular function by echocardiography is frequently challenging in mechanically ventilated patients. We evaluated the potential value of contrast-enhanced imaging and tissue harmonic imaging over standard fundamental imaging for endocardial border detection (EBD) in these patients. Methods and Results Fifty patients underwent standard transthoracic 2D echocardiography and were imaged in fundamental and tissue harmonic modes and subsequently with intravenous contrast (Optison). Two echocardiographers reviewed all studies for ease of visualization of endocardial border segments and scoring of wall motion. EBD for each wall segment was graded from 1 to 4 (1 = excellent EBD). Wall motion was scored by a standard 16-segment model and 1 to 5 scale. Studies were categorized as nondiagnostic if 4 of 6 segments in the apical 4-chamber view were either poorly seen or not seen (EBD score 3 or 4). Quantification of ejection fraction was independently performed offline. Visualization of 68% of all segments improved with contrast echocardiography versus 17% improvement with tissue harmonics compared with fundamental mode. Significant improvement (poor/not seen to good/excellent) occurred in 60% of segments with contrast echocardiography versus 18% with tissue harmonics. A total of 850 segments were deemed poor/not seen, 78% of which improved to good/excellent with contrast echocardiography versus 23% with tissue harmonics. Interobserver agreement on EBD was 64% to 70%. Conversion of nondiagnostic to diagnostic studies occurred in 85% of patients with contrast echocardiography versus 15% of patients with tissue harmonics. Scoring of wall motion with fundamental mode, tissue harmonics, and contrast echocardiography was possible in 61%, 74%, and 95% of individual segments, respectively ( P P =.003) more often over fundamental mode versus a 27% ( P =.09) increase with tissue harmonics. Conclusions Contrast echocardiography is superior to tissue harmonic imaging for EBD, wall motion scoring, and quantification of ejection fraction in mechanically ventilated patients. (Am Heart J 2000;140:291-6.)
Visual perception of objects: an approach to assessment and intervention

This paper proposes an alternative to the deficit-specific approach that has been used to guide the visual perceptual assessment and treatment of brain-injured adults. Recent theoretical advances in visual object perception are combined with a cognitive rehabilitation model to provide a framework for occupational therapy assessment and treatment of object-processing dysfunction. Assessment guidelines are presented that emphasize the analysis of residual function by specifying the task conditions that influence visual perception. A case study illustrates clinical application of this approach. Implications for research are discussed.
Study of low-lying isobaric analogue states of 89Sr

Abstract Isobaric analogue states in 89Sr have been studied via the (p, p) and (p, p′) reactions on 89Sr and were compared with the results of a (d, p) reaction on 88Sr. The (p, p) data have been analyzed with Breit-Wigner theory as well as with coupled-channel calculations. The (p, p′) data obtained with the bombarding energy on analogue resonances display assymmetries about 90°.
The evolution of information systems development approach: some field observations

The approach to information systems development is changing. A new approach, prototyping, is gaining popularity among practitioners in the field. Twelve information systems development projects using the prototyping approach were studied. For each project, the project manager and at least one systems analyst were interviewed. The underlying premises for prototyping and the interview findings concerning the advantages, practicability, and organizational requirements of prototyping are discussed in this article. With growing experience in the use of the approach and the broader availability of powerful software tools, it is timely to consider using prototyping for information systems development.
Geometric simulation and surface statistics of coarsening faceted surfaces

We introduce a general-purpose computational geometry tool for simulating the evolution of single-crystal, threefold-symmetric, 2 + 1D coarsening faceted surfaces z = h(x, y, t). By explicitly tracking the interface with an efficient three-component facet/edge/junction structure, rapid simulations of tens of thousands of facets are realized. Topological rearrangements of the surface, including coarsening events caused by facets merging or vanishing, are treated explicitly using a priori knowledge of the outcome of each event. The speed and flexibility of the resulting method allows the easy extraction of reliable surface statistics describing complex interface morphology. The method is demonstrated using a sample facet dynamics, under which surfaces totaling one million facets are simulated to study the statistics of the emerging dynamically scaling state.
The multiple yield phenomenon in single-fiber composites of iron in copper

Repeated yielding has been observed in single fiber composites of iron in copper. During each yield event, a Luders band forms in the iron, propagates a short distance, and stops. The number of separate yield events decreases with increasing volume fraction of fiber until a critical volume fraction, above which only one yield event per specimen occurs. A model based on interfacial shear and a consequent reduction in Luders band propagation stress has been developed to explain this behavior. The results of the proposed model agree well with the observations. Finally, it is shown that the theories of the volume fraction dependence of composite strength after yield point drops and after fiber failure are quite similar in nature.
Word frequency effects in associative and item recognition

The word frequency effect (WFE) has been taken as evidence that recall and recognition are in some way fundamentally different. Consequently, most models assume that recall and recognition operate via very different retrieval mechanisms. Experiment 1 showed that the WFE reverses for associative recognition, which requires discrimination between intact test pairs and recombinations of study list words from different study pairs. Experiment 2, in which word triples were used, revealed an interaction between word frequency and test type: for item recognition, performance was better for low-frequency words; however, for associative recognition and free recall, performance was better for high-frequency words. In Experiment 3, item recognition was tested: although overall performance was better for low-frequency words, the recognition advantage for items in intact pairs was larger for high-frequency words, suggesting two components in recognition memory. These results imply common mechanisms in recall and recognition. Theoretical implications are discussed within the framework of the SAM model.
Comparison of Natural Convection Flows Under VHTR Type Conditions Modeled by both the Conservation and Incompressible Forms of the Navier-Stokes Equations

Abstract This paper illustrates a comparative study to analyze the physical differences between numerical simulations obtained with both the conservation and incompressible forms of the Navier–Stokes equations for natural convection flows in simple geometries. The purpose of this study is to quantify how the incompressible flow assumption (which is based upon constant density advection, divergence-free flow, and the Boussinesq gravitational body force approximation) differs from the conservation form (which only assumes that the fluid is a continuum) when solving flows driven by gravity acting upon density variations resulting from local temperature gradients. Driving this study is the common use of the incompressible flow assumption in fluid flow simulations for nuclear power applications in natural convection flows subjected to a high heat flux (large temperature differences). A series of simulations were conducted on two-dimensional, differentially heated rectangular geometries and modeled with both hydrodynamic formulations. From these simulations, the selected characterization parameters of maximum Nusselt number, average Nusselt number, and normalized pressure reduction were calculated. Comparisons of these parameters were made with available benchmark solutions for air with the ideal gas assumption at both low and high heat fluxes. Additionally, we generated specific force quantities and velocity and temperature distributions to provide a basis for further analysis. The simulations and analysis were then extended to include helium at the Very High Temperature gas-cooled Reactor (VHTR) normal operating conditions. Our results show that the consequences of incorporating the incompressible flow assumption in high heat flux situations may lead to unrepresentative results. The results question the use of the incompressible flow assumption for simulating fluid flow in an operating nuclear reactor, where large temperature variations are present.
Theory of mind and social inference in children and adolescents with bipolar disorder.

Background Deficits in theory of mind (ToM), or the ability to infer what another person is thinking or feeling, have been reported in manic and euthymic adults with bipolar disorder. To date, there have been no investigations of ToM in pediatric bipolar disorder (PBD). The aim of the current study was to investigate this ability in PBD patients and healthy controls. Method PBD patients (n=26) and intellectually and demographically similar healthy comparison subjects (n=20) were administered two ToM tasks. In the Affective Story Task, subjects were read positive-, negative- and neutral-valenced stories, and were assessed on their ability to recognize that a misleading series of events could lead one character to develop a false belief about another character. On the Hinting Task, subjects were required to infer the real intentions behind subtle hints. Results The PBD group performed significantly more poorly than controls on the Hinting Task and the positive and negative conditions of the Affective Story Task. In the PBD group only, younger age, earlier illness onset and manic symptoms were associated with poorer ToM performance. Conclusions Consistent with past findings in adult bipolar disorder (BD), PBD youth performed more poorly than controls on ToM tasks. Data suggest that ToM ability may be more impaired in affectively charged contexts. Additionally, an earlier onset of illness among PBD youth may interfere with the development of social-cognitive skills. ToM disturbances may be a useful treatment target in PBD, with the aim of facilitating more accurate assessment of social cues and better interpersonal functioning.
The power and pay of international union officials

Secondary data are used to examine the relationship between the power of international union presidents and their pay. The analysis supported the hypotheses that (1) power and pay were positively related and (2) the relationship is more pronounced in unions that are larger and are less effective in bargaining as well as during periods characterized by conflict over the president’s role. While highlighting the political dimensions of union organizations, the data also support previous studies that found international union officers’ salaries to have a “rational” basis in the union’s bargaining effectiveness.
A Comparison of the Abortifacient Risk of Western Juniper Trees in Oregon

On the Ground The bark, leaves, and berries of western juniper trees in Oregon can cause abortions in late-term pregnant cattle. The percentage of the abortion-causing compounds varied from tree to tree in a location, as well as between locations across Oregon, but did not appear to vary across time. Cattle producers who winter cattle in pastures with western juniper trees should take cautions such as denying late-term pregnant cattle access to these pastures, providing adequate feed and shelter, maintaining pregnant cattle in good body condition, changing calving schedules to late spring or early fall, and, if abortions do occur, seeking veterinary care for any postpartum complications.
Two Plasmodium falciparum merozoite surface polypeptides share epitopes with a single Mr 185 000 parasite glycoprotein.

Abstract The malarial parasite Plasmodium falciparum synthesizes a major glycoprotein (gp) of M r 185 000 during its asexual blood cycle. Immunoprecipitation of [ 35 S]methionine- or [ 3 H]glucosamine-labeled schizont antigens indicated that two groups of polypeptides were distinguished with anti-gp 185 mouse monoclonal antibodies: group A was composed of glycosylated molecules of M r 185 000, 120 000, 90 000, 88 000, 46 000, and 40 000 while group B contained, in addition to gp185, polypeptides of M r 152 000, 106 000 and 83 000. The latter polypeptides lacked detectable amounts of radiolabeled saccharide. The smaller M r polypeptides were specifically immunoprecipitated and not merely coprecipitated with gp185. Our results suggest that gp185 contains at least two structurally distinct domains which may be processed independently into either the group A or group B polypeptides. Although gp185 may not be a merozoite surface protein, representative group A and group B-specific monoclonal antibodies bound to surface antigens of the merozoite as demonstrated by immunolabeling followed by electron microscopy. Therefore, at least one group A antigen and one group B antigen appeared to be on the extracellular surface of the merozoite. The proteins found in immunoprecipitates after both (1) sonication in aqueous medium and ultracentrifugation and (2) solubilization and phase separation of parasite molecules with Triton X-114 suggested that the group A and group B polypeptides and glycoproteins are either soluble or peripheral membrane proteins. Some of these, therefore, may be components of the surface coat of the merozoite.
COMT haplotype variation affects human prefrontal function

Unit for Systems Neuroscience in Psychiatry, National Institute of Mental Health, NIH, DHHS, Bethesda, MD, USA; Neuroimaging Core Facility, National Institute of Mental Health, NIH, DHHS, Bethesda, MD, USA; Clinical Brain Disorders Branch, Genes, Cognition and Psychosis Program, National Institute of Mental Health, NIH, DHHS, Bethesda, MD, USA and Department of Biostatistics, University of Michigan, Ann Arbor, MI, USA
A topological study of computer efficiency in network analysis

Topological study of digital computer programming efficiency in electric network analysis, considering cost of computation
Effects of discharge fluctuation and the addition of fine sediment on stream fish and macroinvertebrates below a water-filtration facility

A small, coastal stream in the San Francisco Bay area of California, USA, received the discharges from a drinking-water filtration plant. Two types of discharges were present. Discharges from filter backwashing were 3–4 times base stream flow, occurred 10–60 times per day, contained fine sediments, and each lasted about 10 min. The other discharge was a large, steady flow of relatively sediment-free water from occasional overflow of the delivery aqueduct which generally lasted several hours a day. Samples of invertebrates from natural substrates had significantly fewer taxa and lower density at the two stations below the backwash than at the two above. However, when stable artificial substrates were used, there were no significant differences among all four stations. The aqueduct apparently had no effect because the. invertebrate community at the station upstream of the backwash but downstream of the aqueduct was statistically similar to the station above the aqueduct. To test for acute toxicity, we exposed additional artificial substrates to short-term simulated backwash conditions. These exposures had no effect on invertebrate density or drift. Three-spine stickleback (Gasterosteus aculeatus) populations were also significantly reduced at the two downstream stations and were made up mostly of larger, adult fish. Prickly sculpins (Cottus asper), restricted to the most downstream station, were emaciated and had poor growth, probably as a result of scarce benthic food organisms. Artificial redds with eggs of rainbow trout (Salmo gairdneri) had significantly lower survival at two stations below the plant backwash (30.7% and 41.8%) than at the one above it (61.4%). Hatchery rainbow trout held in cages below the treatment plant from 7 to 37 days survived and continued to feed. Thus, the major effect of the water treatment plant on fish and invertebrates probably was not from acute toxicity in the discharges or the occasionally large discharge of clean water from the aqueduct, but was from the fluctuating backwash flows containing fine sediment that displaced small fish downstream and created unstable benthic substrates for invertebrates. The filter plant that we studied is a direct-feed type (that is, no sedimentation before filtration). These generally require greater frequencies of backwashing than do conventional plants and may therefore have greater biological impacts. Direct-feed plants are becoming increasingly popular throughout the world, for the most part because they are cheaper to build and operate. But if the associated biological problems are mitigated, then the cost savings of direct-feed compared to conventional plants may be lost.