cssi/SciSciGPT-SciSciNet huggingface dataset:
Differential Roles of Blocking Ions in KirBac1.1 Tetramer Stability

Potassium channels are tetrameric proteins that mediate K+-selective transmembrane diffusion. For KcsA, tetramer stability depends on interactions between permeant ions and the channel pore. We have examined the role of pore blockers on the tetramer stability of KirBac1.1. In 150 mm KCl, purified KirBac1.1 protein migrates as a monomer (∼40 kDa) on SDS-PAGE. Addition of Ba2+ (K1/2 ∼ 50 μm) prior to loading results in an additional tetramer band (∼160 kDa). Mutation A109C, at a residue located near the expected Ba2+-binding site, decreased tetramer stabilization by Ba2+ (K1/2 ∼ 300 μm), whereas I131C, located nearby, stabilized tetramers in the absence of Ba2+. Neither mutation affected Ba2+ block of channel activity (using 86Rb+ flux assay). In contrast to Ba2+, Mg2+ had no effect on tetramer stability (even though Mg2+ was a potent blocker). Many studies have shown Cd2+ block of K+ channels as a result of cysteine substitution of cavity-lining M2 (S6) residues, with the implicit interpretation that coordination of a single ion by cysteine side chains along the central axis effectively blocks the pore. We examined blocking and tetramer-stabilizing effects of Cd2+ on KirBac1.1 with cysteine substitutions in M2. Cd2+ block potency followed an α-helical pattern consistent with the crystal structure. Significantly, Cd2+ strongly stabilized tetramers of I138C, located in the center of the inner cavity. This stabilization was additive with the effect of Ba2+, consistent with both ions simultaneously occupying the channel: Ba2+ at the selectivity filter entrance and Cd2+ coordinated by I138C side chains in the inner cavity.
LoQAtE—Localization and Quantitation ATlas of the yeast proteomE. A new tool for multiparametric dissection of single-protein behavior in response to biological perturbations in yeast

Living organisms change their proteome dramatically to sustain a stable internal milieu in fluctuating environments. To study the dynamics of proteins during stress, we measured the localization and abundance of the Saccharomyces cerevisiae proteome under various growth conditions and genetic backgrounds using the GFP collection. We created a database (DB) called 'LoQAtE' (Localizaiton and Quantitation Atlas of the yeast proteomE), available online at http://www.weizmann.ac.il/molgen/loqate/, to provide easy access to these data. Using LoQAtE DB, users can get a profile of changes for proteins of interest as well as querying advanced intersections by either abundance changes, primary localization or localization shifts over the tested conditions. Currently, the DB hosts information on 5330 yeast proteins under three external perturbations (DTT, H₂O₂ and nitrogen starvation) and two genetic mutations [in the chaperonin containing TCP1 (CCT) complex and in the proteasome]. Additional conditions will be uploaded regularly. The data demonstrate hundreds of localization and abundance changes, many of which were not detected at the level of mRNA. LoQAtE is designed to allow easy navigation for non-experts in high-content microscopy and data are available for download. These data should open up new perspectives on the significant role of proteins while combating external and internal fluctuations.
Excitability of guided waves in composites with PWAS transducers

Piezoelectric Wafer Active Sensors (PWAS) are convenient enablers for generating and receiving ultrasonic guided waves. The wide application of composite structures has put new challenges for the Structural Health Monitoring (SHM) and Nondestructive Evaluation (NDE) community due to the general anisotropic behaviors and complicated guided wave features in composites. The excitability of guided waves in composite structures directly influences the implementation of active sensing systems to achieve the best interrogation of certain sensing directions. This paper presents a hybrid modeling technique for studying the excitably of guided waves in composite structures with PWAS transducers. This hybrid technique comprehensively covers local finite element model (FEM), semi-analytical finite element (SAFE) method, and analytical guided wave solutions. Harmonic analysis of a small-size local FEM with non-reflective boundaries (NRB) was carried out for obtaining guided wave generation features in plate structures. The PWAS transducers were modeled with coupled filed elements. Thus, the FEM can fully capture the geometry and material property effects of PWAS transducers and their influence on the guided wave excitation. SAFE method was used to obtain the complicated guided wave features in composites such as dispersion curves and modeshapes. The SAFE procedure was coded into MATLAB Graphical User Interface (GUI), and the software SAFE-DISPERSION was developed. To study the excitability of each wave mode, we considered all the possible wave modes being generated simultaneously and propagating independently. The analytical wave expressions based on the exact guided wave solution with Hankel functions were used to join the SAFE method and the local FEM. Formulated in frequency domain, the hybrid model is highly efficient, providing an over determined equation system for the calculation of mode participation factors. Case studies were carried out: (1) the Lamb wave excitability in an aluminum plate was investigated and compared with classical pin force models to show the feasibility of the hybrid technique; (2) the guided wave excitability in a woven glass fiber composite (GFRP) plate was studied with circular and square PWAS transducers. The paper finishes with summary, conclusions, and suggestions for future work.
Bovine respiratory syncytial virus-specific immune responses in cattle following immunization with modified-live and inactivated vaccines. Analysis of proliferation and secretion of lymphokines by leukocytes in vitro

Cattle were immunized with vaccines containing modified-live or inactivated bovine respiratory syncytial virus (BRSV) and lymphocyte proliferative responses and cytokine secretion were monitored sequentially. Compared to pre-inoculated values, significant increases in proliferative responses to modified-live BRSV were detectable by Day 7 after the primary immunization with the vaccine containing inactivated BRSV, and by 7 days after the second immunization with modified-live virus. After a third immunization with the respective vaccines, proliferative responses to live BRSV were significantly higher in the group that received modified-live vaccine compared to the group that received inactivated vaccine. Proliferative responses to live BRSV corresponded with the presence of interleukin-2 (IL-2) in the supernatants from BRSV-stimulated leukocyte cultures and there were significantly higher levels of IL-2 in cultures from the group that received modified-live BRSV. An interferon species with the characteristics of interferon-alpha was also present in the supernatants from leukocyte cultures and there were no significant differences between the groups of vaccines. The predominant phenotype of proliferating cells in BRSV-stimulated leukocyte cultures derived from both groups of bovine vaccines was a BoCD4+ T-lymphocyte. These in vitro data suggest that both types of vaccines are capable of stimulating cell-mediated immune responses to BRSV in cattle.
Geochemical signatures from the Atlantic coast of Tierra del Fuego and their provenance implications for Magallanes basin sediments

Abstract The Magallanes foreland basin, located along the northern periphery of the Scotia Arc and extending up to 51°S to its northern terminus, contains a near-complete sedimentary record of Fuegian Andes tectonics since the Early Cretaceous. Herein we report trace- and rare-earth-element (REE) geochemistry and Nd isotope ratios from Upper Cretaceous to lower Oligocene mudstones of the eastern Magallanes basin, Argentina. The REE patterns of all of these samples are typical of average post-Archean upper continental crust. The older Upper Cretaceous to middle Eocene samples contain an overall lower concentration of light REE (smaller La N :Sm N ratio) than do the younger, middle-upper Eocene and lower Oligocene samples, although a strict temporal change is not observed. These REE patterns suggest a Patagonian Batholith and mafic volcanic provenance for the older successions and an Eastern Andean metamorphic complex provenance for the younger sediments. The lower Th:Sc ratio of the older samples suggests a mafic origin, whereas the higher Th:Sc ratio of younger samples indicates a felsic origin. Nd isotope data show a broadly coeval shift in eNd values from less negative to more negative. These data, combined with previously reported geochronological and mineral composition provenance analysis, suggest an increased Eocene–Oligocene tectonic exhumation of the southern Andes, concurrent with independent evidence of the opening of the adjacent Drake Passage.
There Began to Be a Learnability Puzzle

One of the fundamental puzzles language learners must solve is the mapping of a string of words onto a particular (correct) syntactic structure. In this article, I examine the problem of how learners should resolve the ambiguity presented by a string that could have either a raising or a control structure. I provide both logical and empirical arguments against the view that children should be biased to assume that such a string has a control structure. Instead, I propose two families of cues, based on a psycholinguistic experiment with adults, which can be used in a probabilistic manner to parse an ambiguous string and to categorize raising and control verbs.
Reaction Kinetics of Thermooxidative Degradation in a Styrene-b-butadiene Diblock Copolymer

Reaction kinetics of thermooxidative degradations in a styrene-block-butadiene diblock (SB) copolymer has been investigated by taking into consideration oxidative chain scission and cross-linking reactions. The gel permeation chromatography (GPC) study revealed that the chain scission not only lowers the overall molecular weight of the copolymer but also drives macrophase separation between polystyrene-rich copolymer and polybutadiene segments. As evidenced in the gel content determination, the molecular weight increases rapidly when the cross-linking reaction becomes dominant. To describe the thermooxidative reaction in the SB copolymer, we propose a simplified reaction scheme in which macrophase separation occurs between polystyrene and polybutadiene segments. Numerical calculations showed that our kinetic model indeed captures the experimental trends such as initial reduction and subsequent increase in molecular weight. The location of concave minimum in the molecular weight vs time curve was found to ...
Photosensitization of nanoporous TiO2 electrodes with InP quantum dots

Quantum dots (QDs) of InP strongly adsorb onto transparent, porous, nanocrystalline TiO2 electrodes prepared by sintering 200−250 A diameter TiO2 colloidal particles. The interparticle space of the TiO2 electrodes is large enough to permit deep penetration of 65-A InP QDs into the porous TiO2 film. The absorption of light increases linearly with the thickness of the TiO2 film indicating that the InP QDs are adsorbed homogeneously on the TiO2 surface. We found that large particles adsorb better than smaller ones probably due to less hindrance by the stabilizer. The solid films exhibit strong photoconductivity in the visible region indicating photosensitization of TiO2 by InP QDs. The photocurrent action spectrum of the TiO2/InP QD film at a potential of +1 V is consistent with the absorption spectrum of the InP QDs. A photoelectrochemical cell was formed that consisted of p-type InP QDs loaded on TiO2, which was immersed in a I-/I3- or hydroquinone/quinone acetonitrile solution, and a Pt counter electrode....
PSYCHOEDUCATION FOR PERSONAL CONTROL: A KEY TO PSYCHOLOGICAL WELL‐BEING OF THE ELDERLY

Counseling older clients requires a focus on maintaining their psychological well‐being in the face of increasing losses associated with the aging process. One important contributing factor is the perception elderly people hold of their ability to control their lives and destinies and to maintain and increase rewarding life events while minimizing aversive ones. Operating within this focus, a psy‐choeducational approach to counseling for psychological control is limited only by motivation of the client and the creativeness of the counselor. The degree to which older clients perceive personal control of life is related to their degree of psychological well‐being.
Spin trapping agent phenyl N‐tert‐butylnitrone protects against the onset of drug‐induced insulin‐dependent diabetes mellitus

Insulin-dependent diabetes mellitus is an autoimmune disease believed to be caused by an inflammatory process in the pancreas leading to selective destruction of the beta-cells. Cytokines and nitric oxide (NO) have been shown to be involved in this destruction. Phenyl N-tert-butylnitrone (PBN) has demonstrated protective effects against several pathological conditions including ischemia-reperfusion injury and endotoxin-induced shock. We report here that PBN co-administration can prevent the onset of the STZ-induced diabetes in mice. PBN co-treatment inhibited the streptozotocin (STZ)-induced hyperglycemia, the elevation in the level of glycated hemoglobin and weight loss in the treated mice. Histological observations indicated destruction of B-cells in the STZ-treated animals and its prevention by PBN co-treatment. EPR spin trapping experiments in the pancreas indicated the in vivo formation of NO in STZ-treated animals and its attenuation by PBN treatment.
Query performance prediction in web search environments

Current prediction techniques, which are generally designed for content-based queries and are typically evaluated on relatively homogenous test collections of small sizes, face serious challenges in web search environments where collections are significantly more heterogeneous and different types of retrieval tasks exist. In this paper, we present three techniques to address these challenges. We focus on performance prediction for two types of queries in web search environments: content-based and Named-Page finding. Our evaluation is mainly performed on the GOV2 collection. In addition to evaluating our models for the two types of queries separately, we consider a more challenging and realistic situation that the two types of queries are mixed together without prior information on query types. To assist prediction under the mixed-query situation, a novel query classifier is adopted. Results show that our prediction of web query performance is substantially more accurate than the current state-of-the-art prediction techniques. Consequently, our paper provides a practical approach to performance prediction in real-world web settings.
Multiple Exciton Generation in Small Si Clusters: A High-Level, Ab Initio Study

The electron-hole excitonic nature of high energy states is investi- gated in neutral and charged Si clusters, motivated by the multiple exciton generation (MEG) process that is highly debated in photovoltaic literature. Silicon forms the basis for much of the photovoltaic industry, and our high-level, first principles calculations show that at 2-3 times the lowest excitation energy, the majority of optically excited states in neutral Si7 and Si10 take on multiple exciton (ME) character. The transition from single excitons (SEs) to MEs is not as sharp in Si as in PbSe clusters, but it is much more pronounced than in CdSe. The closer similarityofSitoPbSethanCdSeisunexpected,sinceSiclustersarelesssymmetric than PbSe clusters. Charging suppresses MEG in Si clusters; however, the suppres- sion is less pronounced than in PbSe. A strong ME signal is seen already at 5 Eg uponcharging.ThelowMEthresholdsandnearlycompleteswitchfromSEstoMEs create a good possibility for efficient MEG in neutral Si nanoclusters and reveal hope that reasonable quantum yields can still be obtained despite charging. SECTION Dynamics, Clusters, Excited States
Mechanical, thermal, and interfacial properties of green composites with ramie fiber and soy resins.

Fully biodegradable, green composites were fabricated with ramie fibers and modified soy flour (MSF) resin. Defatted soy flour (SF) was modified by a lab-scale filtration system to improve its mechanical, interfacial, and thermal properties through increasing the protein content. The protein content of SF was increased from 53.1 to 67.5% by filtering out soluble sugars using a microfiber-based filter. Tensile stress and Young's modulus of MSF resins were 35.5 and 1411.7 MPa, respectively, which were significantly higher than those (12.7 and 379.3 MPa) of SF resins. Interfacial shear strength of single ramie fibers with MSF resins ranged from 8.8 to 15.2 MPa, which were about 40−50% higher than those obtained with SF resins. Tensile stress and Young's modulus of ramie fiber-reinforced composites were 88.0 MPa and 2.94 GPa with SF resin and 103.8 MPa and 3.15 GPa with MSF resin.
Fuzzy Conflict Analysis for QoS Policy Parameters in DiffServ Networks

Policy-based network management is a necessity for managing large-scale environments. It provides the means for separating high-level system requirements from the actual implementation. As the network size increases, the need for automated tools to perform management becomes more apparent. But configuring routers and network devices to achieve QoS goals is a challenging task. Using Differentiated Services to dynamically perform this configuration involves defining policies on different network nodes in multiple domains. Policy aggregation across domains requires a unified policy model that can overcome the challenge of conflict detection and resolution. In this work, we propose a unified model to represent and encode QoS policies. This model enables efficient and flexible conflict analysis. The representation utilizes a bottom-up approach, from the base policy parameters to the aggregation of policies across domains with respect to traffic classes. We also present a classification of these conflicts and a measure of conflicts to assess the severity of any misconfiguration. The model and the conflict measure are evaluated with large networks and different topologies.
Inconclusive evidence regarding the volume of gastric aspirate that can be safely reintroduced following residual volume measurements

Commentary on: ME Juve-Udina, C Valls-Miro, A Carreno-Granero, et al.. To return or to discard? Randomised trial on gastric residual volume management. Intensive Crit Care Nurs2009;25:258–67.
The effect of shear on colloidal aggregation and gelation studied using small-angle light scattering.

Abstract In situ light scattering measurements were performed to investigate the effect of low shear rates (0.13–3.56 s−1) on an aggregating colloidal system made of 20 nm polystyrene particles. The aggregating system was subjected to a shear for a short period (ca. 33 s) and only once at various times after the onset of aggregation. The effect of shear (aggregation kinetics and morphology) was studied both in a cluster dilute and in a cluster dense regime (see introduction). Our results have shown that shear can enhance the aggregation and gelation. Shear induced growth can yield hybrid superaggregates when the system is dense.
Athens and/or Jerusalem

For all three cosmic questions--"Did the universe have a beginning?" "Is the universe designed?" and "Are we alone?"--it was the conjunction as well as the divergence between Athens (Classical philosophy, especially Plato's Timaeus and Aristotle's Physics) and Jerusalem (the Bible, especially the Book of Genesis and the apostle Paul) that illumined the questions themselves, provided material for the answers, and set the terms for the subsequent discussion of them in later centuries.
A framework for the selective dissemination of XML documents based on inferred user profiles

As the amount of data available online and the number of pervasive applications that take advantage of it increase, systems that support selective dissemination of information are becoming more popular. At the same time, XML is becoming the standard for document exchange over the Internet. A key capability of emerging information dissemination systems is therefore the effective filtering of a continuous stream of XML data items according to user preferences. Here we propose a model for information dissemination that integrates profile inference with data dissemination and takes advantage of the structured content in XML documents. Starting from the assumption that explicitly stating one's information interests is an inconvenient and error-prone process, we aim to automatically construct user profiles. We do this by clustering items previously deemed valuable by the user according to a novel similarity measure that takes advantage of the semantic content of XML. Furthermore, we index the profiles from all users into a multilevel index structure whose nodes naturally will be a close match to subject areas present in the document collection. Such an approach is both intuitive and efficient since the indexing structure is not primarily affected by an increasing number of users. To support our claims we experimentally validate our method and report on its effectiveness and efficiency.
Relative stability of de novo four-helix bundle proteins: insights from coarse grained molecular simulations.

We use a recently developed coarse-grained computational model to investigate the relative stability of two different sets of de novo designed four–helix bundle proteins. Our simulations suggest a possible explanation for the experimentally observed increase in stability of the four–helix bundles with increasing sequence length. In details, we show that both short subsequences composed only by polar residues and additional nonpolar residues inserted, via different point mutations in ad hoc positions, seem to play a significant role in stabilizing the four–helix bundle conformation in the longer sequences. Finally, we propose an additional mutation that rescues a short amino acid sequence that would otherwise adopt a compact misfolded state. Our work suggests that simple computational models can be used as a complementary tool in the design process of de novo proteins.
Peroxisome development in the regenerating pars recta (P3 segment) of proximal tubules of the rat kidney.

The development of peroxisomes, lysosomes and endocytic vacuoles in regenerating cells of the pars recta (P3 segment) of proximal tubules, in rats given a single interperitoneal injection of d-serine (80 mg/100 g.b.wt), was studied by light and electron microscopy using cytochemical methods. Rapid proliferation of cells occurred between 2 and 5 days after d-serine induced tubular necrosis; by day 6 almost all injured tubules were re-epithelialized with flat or low cuboidal cells. Peroxisomes and lysosomes were not observed during the period of rapid cell multiplication i.e., between 2 and 6 days after d-serine injection. Restitution of mitochondrial population preceded the development of peroxisomes in the newly regenerated cells of P3 tubules. Maximum development of peroxisomes occurred between 9 and 14 days after d-serine injection. The formation of peroxisomes appeared to correlate closely with the differentiation of apical endocytic vacuoles and the brush border. Lysosomes in the regenerated cells of P3 tubules were the last to develop.
The level set technique for microwave imaging of 3D dielectric objects

The problem of unknown object(s) identification using electromagnetic waves has many potential applications in diverse fields of science and engineering. The electromagnetic waves are used for illumination of the unknown objects and the scattered waves are analyzed for retrieving the profile of the target objects. Therefore developing efficient inverse scattering techniques benefits many applications such as target identification, geophysics, seismic exploration, remote sensing, atmospheric science, Ground Penetrating Radar (GPR) and medical applications such as cancer and hypothermia detection. In shape reconstruction problems, the constitutive parameters of the unknown objects are generally assumed to be known, which mitigates the complexity of the inverse scattering problem. The main idea of the level set method is to embed the evolving interface (contour or surface) as the zero level of a higher-dimensional function. Using the level set framework, topological changes are handled automatically and several objects are reconstructed from a single initial guess simultaneously [1],[2].
Optimal two-point designs for the michaelis-menten model with heteroscedastic errors

We construct D-optimal designs for the Michaelis-Menten model when the variance of the response depends on the independent variable. However, this dependence is only partially known. A Bayesian approacn is used to find an optimal design by incorporating the prior lnformation about the variance structure. We demonstrate the method for a class of error variance structures and present efficiencies of these optimal designs under prior mis-specifications. In particular, we show that an erroneous assumption on the variance structure for the Michaelis-Menten model can have serious consequences.
Fatigue crack propagation at polymer adhesive interfaces

Abstract Fatigue (slow) crack growth in epoxy/glass, epoxy acrylate/glass and epoxy/PMMA interfaces was studied under constant and cyclic loading at both high and low humidities using the interfacial, four-point flexure test. Finite element analysis was used to determine the energy release rate and phase angle appropriate for the different crack geometries observed. The experimental results show that for the polymer/glass interfaces, the primary driving force for fatigue crack growth is the applied energy release rate at the crack tip and that increasing test humidity enhances crack growth under constant loading but has an insignificant effect under cyclic loading. At low humidity the crack growth rates under cyclic loading are significantly greater than under constant loading. For epoxy/PMMA interfaces the crack growth results were independent of the applied energy release rate, relative humidity, and cyclic vs. constant loading, within experimental scatter. In addition, for polymer/glass interfaces the ...
Calculation of Internal Fault Currents in Synchronous Machines

An internal fault in the armature winding of a synchronous machine occurs at the breakdown of either the minor insulation (turn-to-turn fault) or the major insulation (phase-to-ground fault). The faulty synchronous machine is represented by an equivalent circuit in three symmetrical components which can be connected to the corresponding network. The fault currents can be calculated from the obtained equivalent network. The calculation of internal fault currents has been programmed for the IBM 7090 digital computer, and the calculated values have been compared with the experimental results.
Delay and capacity in energy efficient sensor networks

MAC protocols for wireless sensor networks employ periodic switching to low energy sleep state in order to enhance network lifetime. During the sleep state, the sensors do not perform energy consuming operations such as receiving and transmitting packets. During the normal state, CSMA based multi-access mechanism is the MAC protocol of choice in distributed, unsynchronized sensor networks. The energy conserving mechanism has a two-fold effect on delay in the network. On one hand it increases delay since many a times the intended receiver may be in sleep state and the transmitter has to delay the transmission to allow the receiver to wake up. On the other hand, since the sensors do not transmit in sleep state, the contention for channel is reduced which tends to improve delay. In this paper we present a queuing theoretic analysis of delay and capacity in sensor networks with uncoordinated sleep mechanism and characterize the energy-delay-capacity tradeoffs. We consider several sleep states which consume different levels of energy. We model sensor networks as queuing networks and evaluate closed form expressions for average packet delay and maximum achievable per-node throughput in terms of network parameters and sleep schedule. Comparisons with the performance of networks that do not employ any energy conserving mechanisms show that any of the energy conserving sleep states in the networks considered in this paper leads to considerable degradation in delay and capacity of the network.
Increased monocyte nuclear factor-κB activation and tumor necrosis factor production in alcoholic hepatitis

Increased tumor necrosis factor-a activity has been reported in patients with alcoholic hepatitis and is implicated in its pathogenesis. The aim of this study was to investigate potential mechanisms of increased tumor necrosis factor-a activity in alcoholic hepatitis. Monocyte nuclear factor-kB activity was assessed by electrophoretic mobility shift assay, monocyte tumor necrosis factor-a mRNA was semi-quantitatively assessed by reverse transcriptase polymerase chain reaction, and tumor necrosis factor-a in monocyte culture supernatants was measured. There was significantly greater spontaneous nuclear factor-kB activity in the monocytes of 6 patients with alcoholic hepatitis as compared with that in the monocytes of control subjects. There was spontaneous tumor necrosis factor-a mRNA and tumor necrosis factor-a release from the monocytes of patients with alcoholic hepatitis but not from the monocytes of normal subjects. Endotoxin increased nuclear factor-kB activity and induced tumor necrosis factor-a mRNA and tumor necrosis factor-a release from normal subjects' monocytes. Endotoxin further increased nuclear factor-kB activity, tumor necrosis factor-a mRNA, and tumor necrosis factor-a release from the monocytes of patients with alcoholic hepatitis. Supershift assays indicate that the monocyte nuclear factor-kB activation involves the p50 and p65 subunits. Dysregulated tumor necrosis factor-a metabolism in alcoholic hepatitis monocytes is associated with increased nuclear factor-kB activity and tumor necrosis factor-a mRNA expression.
The Welcoming of Copernicus's De revolutionibus: The Commentariolus and its Reception

was published in 1543, the sun-cen tered universe it described was hardly novel. He had announced it some thirty years before in the brief account known as the Commentariolus that had circulated in manuscript over the decades between. This was strictly an astronomical work. To appreciate it and understand how he came by his ideas requires some knowledge of astronomical phenomena and of the geometrical models that Ptolemy used and Copernicus remodelled to account for them. Those models are sketched here in detail, as well as the plausible path by which he was led to remodel the universe.
Enhanced ratiometric fluorescent indicators for magnesium based on azoles of the heavier chalcogens.

Red-shifted fluorescent indicators for magnesium were developed by incorporation of sulfur or selenium in the azole moiety of ‘fura’ fluorophores. Single atom replacement in the acceptor of these ITC probes affords longer excitation and emission wavelengths as well as greater separation between excitation bands, valuable for ratiometric intracellular Mg2+ imaging.
Adaptive pulselength correction (APLECORR): a strategy for waveform optimization in ultra-wideband active sonar

This paper describes a technique for optimizing the detection index (and as a result, the probability of detection) of an active sonar in doubly-spread channels by proper distribution of transmitted energy in the band. The method requires measurement of reverberation and ambient noise spectra in the band, and a prediction of signal energy as a function of frequency for a trial waveform. The amount of improvement over the trial waveform is high when there are large fluctuations of the reverberation-to-ambient noise ratio in the band. Thus, the method is most useful for wideband systems.
Nitrous oxide-induced myelopathy with inverted V-sign on spinal MRI

A previously healthy 28-year-old male presented with a seven-day history of progressive weakness, numbness and paraesthesias, which initially began in the upper extremities, and subsequently spread to the lower extremities. These symptoms were accompanied by Lhermitte's sign, sexual dysfunction and constipation. Social history was significant for recreational nitrous oxide abuse, characterised by the inhalation of …
Investigations of Plasma Immersion Ion Implantation Hydrogenation for Poly-Si Tfts Using an Inductively Coupled Plasma Source

A plasma immersion ion implantation (PIII) hydrogenation process using an inductively-coupled plasma (ICP) source is implemented for defect passivation in polycrystalline silicon (poly-Si) thin film transistors (TFT’s). Device parameter improvement saturates in 4 minutes, which is considerably shorter than for other reported hydrogenation methods. Stress test indicates that the devices hydrogenated by this novel technique have much better long-term reliability. The hydrogenation effects on two types of trap states are analyzed the current-voltage characteristics of the devices. The densities of deep states and tail states are significantly reduced after short time hydrogenation.
Progressive compression of 3D graphic models

A progressive coding method which encodes a 3D graphic model into an embedded bit stream is investigated in this research. The coder first encodes the coarsest resolution of the model, and then includes the finer details gradually. The embedding property allows the decoder to terminate the decoding at an arbitrary position in the compressed bit stream, and a more accurate model can be obtained when more bits are decoded. Numerical experiments are provided to demonstrate the excellent rate distortion performance and progressive compression performance of the new method.
Triangles in a complete chromatic graph

Suppose that in a complete graph on N points, each edge is given arbitrarily either the color red or the color blue, but the total number of blue edges is fixed at T . We find the minimum number of monochromatic triangles in the graph as a function of N and T . The maximum number of monochromatic triangles presents a more difficult problem. Here we propose a reasonable conjecture supported by examples.
Crosstalk driven routing advice

This paper examines the feasibility of generating routing advice for interconnects on printed circuit boards (PCBs) at the design stage, on the basis of crosstalk noise requirements and relevant timing information. A set of analytical expressions have been developed to relate physical design parameters, such as the spacing between a pair of coupled signal lines, to the amount of crosstalk noise generated on these lines. Timing windows have been used to define time intervals during which noise on a specific signal line can affect the functioning of the entire system. An algorithm has been developed, based on the above expressions, to estimate the minimum safe spacing between a pair of coupled signal lines, given the crosstalk noise budget and timing information. >
Night Blindness in a Teenager With Cystic Fibrosis

This article describes the case of a 16-year-old boy with cystic fibrosis who presented with difficulty seeing in the dark. He had a history of bowel surgery at birth, and he developed cystic fibrosis liver disease and osteopenia during his teenage years. He always had good lung function. When his serum vitamin A level was checked, it was undetectable in sample. He was diagnosed with night blindness and commenced on high-dose vitamin A. His symptoms resolved within 3 days. However, it took over 1 year for his vitamin A level to return to normal. This case emphasizes the importance of monitoring vitamin levels in cystic fibrosis to detect deficiency and prevent long-term consequences, and it highlights the challenges encountered during the course of night blindness treatment.
INHIBITION OF THEILER'S ENCEPHALOMYELITIS VIRUS (GDVII STRAIN) OF MICE BY AN INTESTINAL MUCOPOLYSACCHARIDE : II. PURIFICATION AND PROPERTIES OF THE MUCOPOLYSACCHARIDE

A mucopolysaccharide inhibitor of Theiler's GDVII virus has been purified from intestinal tissue of adult mice. The purified material has been shown to consist chiefly of carbohydrate. Following acid hydrolysis of the inhibitor, several amino adds were found to be present. The carbohydrate components shown to be present thus far are galactose, hexosamine, N-acetylhexosamine, methylpentose, hexurornic acid; an indication has been obtained that sedoheptulose is also present. The available evidence strongly suggests that this mucopolysaccharide, and not some other substance present in minute amounts, is the inhibitor of the GDVII virus.
A big-microsite framework for soil carbon modeling.

Soil carbon cycling processes potentially play a large role in biotic feedbacks to climate change, but little agreement exists at present on what the core of numerical soil C cycling models should look like. In contrast, most canopy models of photosynthesis and leaf gas exchange share a common ‘Farquhaur-model’ core structure. Here, we explore why a similar core model structure for heterotrophic soil respiration remains elusive and how a pathway to that goal might be envisioned. The spatial and temporal variation in soil microsite conditions greatly complicates modeling efforts, but we believe it is possible to develop a tractable number of parameterizable equations that are organized into a coherent, modular, numerical model structure. First, we show parallels in insights gleaned from linking Arrhenius and Michaelis–Menten kinetics for both photosynthesis and soil respiration. Additional equations and layers of complexity are then added to simulate substrate supply. For soils, model modules that simulate carbon stabilization processes will be key to estimating the fraction of soil C that is accessible to enzymes. Potential modules for dynamic photosynthate input, wetting-event inputs, freeze–thaw impacts on substrate diffusion, aggregate turnover, soluble-C sorption, gas transport, methane respiration, and microbial dynamics are described for conceptually and numerically linking our understanding of fast-response processes of soil gas exchange with longer-term dynamics of soil carbon and nitrogen stocks.
Uncertainty Forecasts Improve Weather-Related Decisions and Attenuate the Effects of Forecast Error

Although uncertainty is inherent in weather forecasts, explicit numeric uncertainty estimates are rarely included in public forecasts for fear that they will be misunderstood. Of particular concern are situations in which precautionary action is required at low probabilities, often the case with severe events. At present, a categorical weather warning system is used. The work reported here tested the relative benefits of several forecast formats, comparing decisions made with and without uncertainty forecasts. In three experiments, participants assumed the role of a manager of a road maintenance company in charge of deciding whether to pay to salt the roads and avoid a potential penalty associated with icy conditions. Participants used overnight low temperature forecasts accompanied in some conditions by uncertainty estimates and in others by decision advice comparable to categorical warnings. Results suggested that uncertainty information improved decision quality overall and increased trust in the forecast. Participants with uncertainty forecasts took appropriate precautionary action and withheld unnecessary action more often than did participants using deterministic forecasts. When error in the forecast increased, participants with conventional forecasts were reluctant to act. However, this effect was attenuated by uncertainty forecasts. Providing categorical decision advice alone did not improve decisions. However, combining decision advice with uncertainty estimates resulted in the best performance overall. The results reported here have important implications for the development of forecast formats to increase compliance with severe weather warnings as well as other domains in which one must act in the face of uncertainty.
New Hepatitis C Virus Drug Discovery Strategies and Model Systems

Introduction: Hepatitis C virus (HCV) is a major cause of liver disease worldwide and the leading indication for liver transplantation in the United States. Current treatment options are expensive, not effective in all patients and are associated with serious side effects. Although preclinical, anti-HCV drug screening is still hampered by the lack of readily infectable small animal models, the development of cell culture HCV experimental model systems has driven a promising new wave of HCV antiviral drug discovery. Areas covered: This review contains a concise overview of current HCV treatment options and limitations with a subsequent in-depth focus on the available experimental models and novel strategies that have, and continue to enable, important advances in HCV drug development. Expert opinion: With a large cohort of chronically HCV-infected patients progressively developing liver disease that puts them at risk for hepatocellular carcinoma and hepatic decompensation, there is an urgent need to develo...
Firm Diversity: Conceptualization and Measurement

Two fundamentally different ways of conceptualizing and measuring firm diversity—by business count and by strategy—are identified, their strengths and weaknesses discussed, and their suitability for investigating commonly asked questions evaluated. A business count measure is claimed to be suitable for research comparing diversified and nondiversified firms but not for investigating differences among diversified firms. For the latter task, a strategic measure of diversity is recommended.
Effect of optical digitizer selection on the application accuracy of a surgical localization system - A quantitative comparison between the OPTOTRAK and FlashPoint tracking systems

Application accuracy is a crucial factor for stereotactic surgical localization systems, in which space digitization camera systems are one of the most critical components. In this study we compared the effect of the OPTOTRAK 3020 space digitization system and the FlashPoint Model 3000 and 5000 3D digitizer systems on the application accuracy for interactive localization of intracranial lesions. A phantom was mounted with several implantable frameless markers which were randomly distributed on its surface. The target point was digitized and the coordinates were recorded and compared with reference points. The differences from the reference points represented the deviation from the "true point." The root mean square (RMS) was calculated to show the differences, and a paired t-test was used to analyze the results. The results with the phantom showed that, for 1-mm sections of CT scans, the RMS was 0.76 +/- 0. 54 mm for the OPTOTRAK system, 1.23 +/- 0.53 mm for the FlashPoint Model 3000 3D digitizer system, and 1.00 +/- 0.42 mm for the FlashPoint Model 5000 system. These preliminary results showed that there is no significant difference between the three tracking systems, and, from the quality point of view, they can all be used for image-guided surgery procedures. Copyright 1999 Wiley-Liss, Inc.
Imaging of Prostheses

This chapter covers relevant aspects of imaging of prostheses. Initially, a brief historical review is given, as well as a description of the relevant terminology in the radiology of prostheses. This is followed by an in-depth discussion of the composition of current prostheses, including individual designs. The indications and contraindications are then outlined. The preoperative and postoperative evaluation of images follows, with a description of the various measurements, including angles that are relevant to the radiologist and orthopedist. Finally, a description of the immediate and delayed complications that are encountered, including the pathogenesis of these complications, completes the chapter.
Effects of morphine on colonic myoelectric and motor activity in subhuman primates

We investigated the effects of numerous doses of morphine on colonic myoelectric and motor activity in monkeys. In each of four monkeys (Macaca arctoides), combined strain gauge transducers and bipolar electrodes were chronically implanted at four defined sites in the colon and recordings were made for 3 h in fasted, unanesthetized animals before and after intravenous administration of morphine sulfate (10-1,000 micrograms/kg). The basal fasting pattern of colonic motility was characterized by random contractions, nonmigrating clusters of contractions, and migrating individual contractions. Morphine at very low doses (10-25 micrograms/kg) had no effect on colonic motility at any site. At doses of 50-200 micrograms/kg, clusters and migrating contractions were eliminated, but there was an overall increase in the frequency of random contractions without an alteration in contraction amplitude or duration. At morphine doses of 500 and 1,000 micrograms/kg, contraction clusters and migrating contractions also were not seen, but there was a decrease in the colonic motility index caused entirely by a decreased frequency of random contractions. Both stimulation and inhibition were most marked in the sigmoid colon. Morphine has a dose-dependent biphasic effect on colonic myoelectric and contractile activity and alters colonic motility patterns by inhibiting migrating contractions and clusters of contractions.
Implementing logical variables on a graph reduction architecture

Logical variables offer a semantic meeting ground between functional and logic programming languages. That is, if functional languages are extended to do parameter passage by unification, much of the power of AND-parallel logic programming is obtained. However, multi-path search, by OR-parallelism or backtracking, remains the province of logic programming.
Removing the Star Wars obstacle

Soviet concessions on interpretation of the ABM Treaty have opened the way to fundamental changes in the superpowers' nuclear relationship, while the Reagan Administration's own position is legally indefensible and strategically unwise.
Etomidate is still a valid anesthetic for electroconvulsive therapy.

AbstractKomatsu et al have recently written that the use of etomidate as an anesthetic induction agent for surgery is associated with increased 30-day mortality and cardiovascular morbidity, compared with propofol. Etomidate has long been recognized as suppressing adrenocortical function and, as an
Processing and Electrochemical Properties of Mixed Conducting Lat-xAxCo1-yFeyO3-δ (A=Sr, Ca)

Powder compositions in the series Lat-xAxCo1-yFeyO3-δ (A=Sr, Ca) have been prepared by a combustion synthesis method. Sintering of pressed powders produced high-density test specimens with the perovskite structure. The specimens exhibited high electrical conductivities with appreciable oxygen-ion conductivity that increased with Co content for the compositions studied. Oxygen permeation studies showed a significant flux of oxygen that increased with temperature for specimens in a P(O2) gradient with no applied field. Thermogravimetric studies of the Lat-xCo0.2Fe0.8O3-δ system indicated a reversible mass loss with increasing temperature that increased with Sr content.
Consent to treatment with zidovudine among HIV-infected patients.

Zidovudine delays the progression of disease in asymptomatic or mildly symptomatic patients infected with human immunodeficiency virus (HIV), but it can cause serious adverse reactions, a fact which makes zidovudine treatment undesirable to some patients. In this study, zidovudine was offered to HIV-infected patients with CD4 leukocyte counts between 200 and 500 cells/μ, L, and the acceptance or refusal of therapy was recorded over a 4-month period. Of 73 patients approached, 49 (67%) consented to the therapy (23 asymptomatic and 26 with AIDS-related complex). The high acceptance rate of zidovudine among both asymptomatic and mildly symptomatic HIV patients raises the question of finding additional financial resources and health care providers for close monitoring of side effects.