cssi/SciSciGPT-SciSciNet huggingface dataset:
A new method for the biaxial testing of cellular solids

Commercial cellular solids such as metal foams and honeycombs exhibit deformation and failure responses that are dependent on specimen size during testing. For foams, this size dependence originates from the fabrication-induced material and structural inhomogeneities, which cause the uncontrolled localization of deformation during the testing of foam cubes. Different peak loads and failure modes are observed in honeycomb specimens in the plate-shear configuration depending on specimen height. This size dependence causes difficulty in obtaining a more representative constitutive behavior of the material. It has recently been established that the size dependence under uniaxial compression can be eliminated with tapered cellular specimens, which enable controlled deformation at a given region of the specimen. This concept is extended in this paper to the biaxial testing of butterfly-shaped cellular specimens in the Arcan apparatus, which focuses deformation at the central section of the specimen. The Arcan apparatus has been modified such that all displacements at the boundaries of the specimen could be controlled during testing. As a consequence of this fully displacement controlled Arcan apparatus, a force perpendicular to that applied by the standard universal testing machine is generated and becomes significant. Thus, an additional load cell is integrated on the apparatus to measure this load. Example responses of butterfly-shaped specimens composed of aluminum alloy honeycomb, aluminum alloy foam and hybrid stainless-steel assembly are presented to illustrate the capabilities of this new testing method.
John Dewey and the philosophical foundations of democracy

Abstract Although Dewey rejects the traditional ancient and modern ways of attempting to find a standard of rightness in nature, he is not the sort of anti-traditional philosopher one would suppose he is from reading Rorty's account of him. This article first explains how Dewey's defense of democratic government rests on the core of his metaphysics. Then it contrasts Dewey's and Rorty's political teachings; Dewey finds infeasible the kind of fragmentation of private and public conduct that Rorty sanctions. Finally, it returns to Dewey's fundamental article of faith, that the experimental method is the method of successful inquiry, to suggest further exploration of the relation between philosophy and faith, on the grounds that he fails to explore it adequately.
Behavioral effects of invaders: alien crayfish and native sculpin in a California stream

Invasive crayfish have been shown to have negative impacts on a range of taxa, though the mechanisms for those effects have not always been evaluated. Signal crayfish (Pacifastacus leniusculus) in Sagehen Creek were associated with reduced growth rates and gut fullness of Paiute sculpin (Cottus beldingi) in earlier experiments. This paper assesses potential behavioral mechanisms of competition between the two species. I conducted experiments to determine crayfish effects on sculpin behavior and habitat use in a stream observation facility at the Sagehen Research Station, California, USA. Sculpin reduced their use of refuges and pools, shifted into higher-velocity microhabitats, and spent more time fleeing in the presence of crayfish. Crayfish used refuges, pools, and low-velocity habitats more than sculpin in either treatment. Both species were notably nocturnal, with most activity at dusk and night observations, although crayfish were more strongly so than sculpin. Detailed field surveys of lower Sagehen Creek found that potential refuges (unembedded rocks) were closely associated with total crayfish and sculpin numbers, suggesting that cover is at least sometimes limiting under natural conditions. By displacing sculpin from refuges and pools and increasing their activity rate, crayfish may increase the likelihood of predation on sculpin. Behavioral shifts in sculpin appear to be at least partly responsible for the reduced growth rates of sculpin in the presence of crayfish.
Effects of hippocampal lesions on the copulatory behavior of male rats

Abstract Performance on two preoperative and two postoperative copulation tests was compared for male rats given total hippocampal, dorsal hippocampal, neocortical, and no lesions. Eight rats were in each group. Tests were continued to a satiety criterion. Statistically significant increases in Mount Latency and Intromission Latency were found in the rats with total hippocampal lesions. There were no other significant differences.
Concurrent inflammation as a determinant of susceptibility to toxicity from xenobiotic agents

Sensitivity to the toxic effects of xenobiotic agents is influenced by a number of factors. Recent evidence derived from studies using experimental animals suggests that inflammation is one of these factors. For example, induction of inflammation by coexposure to bacterial endotoxin, vitamin A or Corynebacterium parvum increases injury in response to a number of xenobiotic agents that target liver. These agents are diverse in chemical nature and in mechanism of hepatotoxic action. Factors critical to the augmentation of liver injury by inflammation include Kupffer cells, neutrophils, cytokines such as tumor necrosis factor-alpha (TNF-alpha) and lipid mediators such as prostaglandins, but these may vary depending on the xenobiotic agent and the mechanisms by which it alters hepatocellular homeostasis. In addition, the timing of inflammagen exposure can qualitatively alter the toxic response to chemicals. Inflammation-induced increases in susceptibility to toxicity are not limited to liver. Concurrent inflammation also sensitizes animals to the toxic effects of agents that damage the respiratory tract, kidney and lymphoid tissue. It is concluded that inflammation should be considered as a determinant of susceptibility to intoxication by xenobiotic exposure.
MM3 Conformational Analysis and X‐ray Crystal Structure of 2,3,4,5‐Tetra‐O‐Acetyl‐N,N′‐Dimethyl‐D‐Glucaramide as a Conformational Model for the d‐Glucaryl Unit of Poly(Alkylene 2,3,4,5‐Tetra‐O‐Acetyl‐d‐Glucaramides)

This report describes the MM3 conformational analysis and X‐ray crystal structure of tetra‐O‐acetyl‐N,N′‐dimethyl‐d‐glucaramide as a conformational model for the D‐glucaryl monomer unit of poly(alkylene tetra‐O‐acyl‐d‐glucaramides). The driving force for this study was to determine the conformational preferences for the diacid unit as a function of the increasing steric bulk of pendant O‐acyl groups: acetyl, propanoyl, 2‐methylpropanoyl, and 2,2‐dimethylpropanoyl. The model dialkyl d‐glucaramides all displayed a large vicinal proton coupling between the central backbone glucaryl hydrogens, indicating an essentially fixed anti conformational arrangement of these protons. The MM3 molecular mechanics program was then applied to calculate the corresponding low‐energy conformations of the structurally simplest of these molecules, tetra‐O‐acetyl‐N,N′‐dimethyl‐d‐glucaramide (4). Given the large number of dihedral angles to be considered and the apparent rigidity of these molecules around the central carbons of t...
Effects of morphine and opioid peptides on plasma levels of atrial natriuretic peptide

Abstract The effect of opiate ligand administration on plasma levels of atrial natriuretic peptide (ANP) was studued in awake, freely moving Sprague-Dawley rats. Prior to and following the intracerebroventricular (icv) or central venous (iv) injection of morphine (MS), leu-enkephalin (Leu-enk), dynorphin (Dyn) or β-endorphin (B-endor), plasma samples were obtained for measurement of ANP concentrations by radioimmunoassay. MS was 10 times more potent when given icv than when given iv to increase plasma ANP levels. Icv injection of Leu-enk decreased plasma ANP concentrations. Dyn and B-endor administration (iv or icv) did not alter the plasma concentration of ANP. These effects of MS and Leu-enk on plasma concentrations of ANP appear to be mediated through actions on the central nervous system. MS, Leu-enk, B-endor, and Dyn given icv, produced elevations of plasma norepinephrine (NE) and epinephrine (Epi) concentrations. When MS was given icv, mean Epi and NE plasma levels increased 10–50 times the increases noted with B-endor, Leu-enk and Dyn. A role of catecholamines in mediating MS-stimulated ANP release is supported by the observation that ganglionic blockade with chlorisondamine significantly attenuated the increase of plasma ANP levels. MS, but not B-endor, Leu-enk and Dyn, acts within the brain to increase plasma levels of ANP. MS-induced elevations of plasma ANP levels may be dependent on an intact autonomic nervous system.
Regulation of liver acyl-coa synthetase activity

Abstract 1. 1. Increased activity was observed upon addition of cell supernatant fraction during in vitro assay of rat liver microsomal acyl-CoA synthetase. However, when a constant fatty acid/protein ratio was maintained then the increased activity could be accounted for by the residual activity in the added supernatant alone. We therefore fail to confirm the existence of a “supernatant stimulating factor”1–5. 2. 2. The acyl-CoA synthetase activities of whole homogenates prepared from livers of either fed or 48 h fasted rats were the same. We therefore fail to confirm the in vivo regulatory role attributed to the “supernatant stimulating factor” as determined by increased acyl-CoA synthetase activity of whole homogenates prepared from livers of 48 h fasted rats compared with the activity of homogenates prepared from livers of fed rats4. 3. 3. Microsomal and mitochondrial acyl-CoA synthetase activities were not affected by 48 h fasting and only increased slightly (15–25%) after refeeding fasted rats a stock diet, a high fat diet (15% corn oil) or a fat free diet. We therefore conclude that acyl-CoA synthetases are constitutive enzymes of the endoplasmic reticulum and outer mitochondrial membrane whose activity does not vary with fasting or feeding various diets. 4. 4. The implications of these findings for fatty acid metabolism are discussed.
A three-dimensional model for flow pumping in a microchannel inspired by insect respiration

We present a three-dimensional model for flow pumping in a channel induced by two moving contractions from the upper wall. This pumping model is inspired by insect respiration processes, specifically, the rhythmic collapses that take place within their tracheal tube networks. The present work is a natural extension of our previous theoretical and numerical investigations of a two-dimensional insect-inspired micropumping model, which accounts for three-dimensional effects and further validates our insect-inspired pumping paradigm (Aboelkassem and Staples in Acta Mech 223(3):463–480, 2012a; Theor Comput Fluid Dyn, 2012b. doi: 10.1007/s00162-012-0269-7 ). The formal goal of this article is to compare three-dimensional Stokeslets-meshfree numerical results with results from our previous two-dimensional analytical pumping model. We use regularized Stokeslets-meshfree computations in three dimensions to reconstruct the flow motions induced by wall contractions and to calculate the time-averaged net flow pumping rate. The results show that, although the net flow rate distribution as a function of the wall motion time (phase) lag parameter for the three-dimensional Stokeslets-meshfree computations and the two-dimensional analytical model displays some differences, the same basic features appear in both cases, leading to the same general conclusions about the proposed pumping paradigm.
Dependency of Cassia siamea on vesicular arbuscular mycorrhizal fungi

Abstract Thirty‐day‐old seedlings of Cassia siamea were transplanted into pots containing a subsurface Oxisol uninoculated or inoculated with Glomus agaregatum at two target soil solution phosphorus (P) concentrations. While no evidence of Vesicular‐arbuscular mycorrhizal fungal (VAMF) colonization was noted in the uninoculated soil, C. siamea roots were colonized to the extent of 63 and 61% at soil P concentrations of 0.02 and 0.2 mg/L, respectively. VAMF colonization led to significant increases in tissue P concentrations measured at harvest at both soil P concentrations. However, shoot dry matter yield was significantly increased only at the first soil P concentration. Shoot dry matter yield of mycorrhizal C. siamea at soil P concentration of 0.02 mg/L was comparable to mycorrhizal growth of C. siamea at soil P concentration of 0.2 mg/L but inferior to the nonmycorrhizal growth of the legume. Based on these response patterns, C. siamea was classified as a highly mycorrhizal dependent species.
Ability of Lipid Hydroperoxides To Partition into Surfactant Micelles and Alter Lipid Oxidation Rates in Emulsions

Lipid hydroperoxides are important factors in lipid oxidation due to their ability to decompose into free radicals. In oil-in-water emulsions, the physical location of lipid hydroperoxides could impact their ability to interact with prooxidants such as iron. Interfacial tension measurements show that linoleic acid, methyl linoleate, and trilinolein hydroperoxides are more surface-active than their non-peroxidized counterparts. In oil-in-water emulsion containing surfactant (Brij 76) micelles in the continuous phase, linoleic acid, methyl linoleate, and trilinolein hydroperoxides were solubilized out of the lipid droplets into the aqueous phase. Brij 76 solubilization of the different hydroperoxides was in the order of linoleic acid > trilinolein > or = methyl linoleate. Brij 76 micelles inhibited lipid oxidation of corn oil-in-water emulsions with greater inhibition of oxidation occurring in emulsions containing linoleic acid hydroperoxides. Surfactant solubilization of lipid hydroperoxides could be responsible for the ability of surfactant micelles to inhibit lipid oxidation in oil-in-water emulsions.
Clinical Use of Laboratory Determinations for Metals, Anticonvulsive Agents, and Cardiovascular Drugs

Measurements of trace metals and other metallic substances have proved to be of great value to clinicians with re-. gard to inborn errors of metabolism, some deficiency states, and toxicological problems. Measurements of the blood levels of anticonvulsive medications and of selected cardiovascular drugs have also proved to be useful in adjusting dosage to attain the therapeutic response desired without toxicity. The clinican must understand the value and the limitations of each of the tests at his disposal (1). While most techniques at present measure the total concentration of a drug in the serum, there may not be uniform correlation between the active component of the drug in the serum and in the tissues. Individual genetic factors may also cause variation in the effect of the drug and the serum level. Drug levels may vary depending on the time of administration of the last dose. Interfering substances may invalidate the results obtained, The concomitant administration of other drugs may interfere with the relationship between the serum level and the effect obtained. One of the values of serum determinations of medications is to test for compliance on the part of the patient. Similar limitations must be considered with regard to determinations for trace metals.
Fundamentals Of Computerized Tomography (CT) Tissue Characterization Of The Brain

The quantitative nature of Computerized Tomography (CT) has suggested the use of the numbers to characterize tissues being imaged almost from the beginning of clinical application. Early attempts, however, quickly dampened the enthusiasm of some proponents even to the extent of leading them to state categorically that such applications are useless, if not downright misleading. There are several major stumbling blocks to overcome: 1. Calibration of the unit must be carefully maintained, 2. Beam hardening artifacts must be carefully accounted for, 3. Normal biological variation must be established as well as a listing of independent parameters that cause variations, 4. Common abnormalities must be catalogued as well as their influence on CT number, 5. Useable criteria to establish or suggest a given diagnosis must be identified and tested.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The N-terminal half of NPM dissociates from nucleoli of HeLa cells after anticancer drug treatments.

NPM (nucleophosmin/B23) is a nucleolar phosphoprotein abundant in tumor cells. It dissociates from nucleoli of cells after treatments with various anticancer drugs. To determine the domain of NPM responsible for nucleolar binding, the N- and C-terminal halves of NPM were fused to GFP (green fluorescent protein) and introduced into HeLa cells. The N-terminal half (aa 1-150) of NPM (GFP-NPM(N)) was found localized in the nucleoli. A stable transformant of GFP-NPM(N) in HeLa cells was prepared and tested for association to nucleoli after anticancer drug treatments. GFP-NPM(N) dissociates from nucleoli after treatments with daunomycin, actinomycin D, camptothecin, and toyocamycin. The dissociation is time- and dose-dependent, and correlates with the cytotoxicity induced by the drugs. These results indicate that a stable transformant of GFP-NPM(N) in HeLa cells may be useful for the screening of anticancer drugs.
Urinary diversions after radiation for prostate cancer: indications and treatment.

Objective To characterize the presentation and symptom progression culminating in urinary diversion after radiotherapy for prostate cancer at a tertiary care reconstructive urology practice. Materials and Methods Retrospective review of electronic medical records was performed for all patients between 2005 and 2011 who underwent urinary diversion for urologic complications of radiation therapy for treatment of prostate cancer. We analyzed demographics, type of radiation, presenting symptoms, diagnostic evaluation, and surgical interventions. Results Of the 30 patients identified, 20% underwent external beam radiotherapy, 37% underwent brachytherapy, and 43% underwent combination therapy. Average time from radiation treatment until presentation to our institution was 4.6 years. Overall indications for urinary diversion included fistula (37%), end-stage bladder (20%), devastated outlet (27%), and a combination of end-stage bladder and devastated outlet (17%). Types of urinary diversion included cystectomy with conduit diversion, conduit diversion alone, and chronic indwelling suprapubic catheter. Eight patients additionally required bowel diversion for intractable gastrointestinal symptoms. Patients underwent an average of 4.4 procedures attempting to salvage native voiding function before urinary diversion. Conclusion The reported need for urinary diversion after radiation therapy for prostate cancer is rare and thus indications have not been well characterized. We found that all of our patients with rectourethral fistula had prior placement of brachytherapy seeds. External beam radiotherapy resulted in a higher incidence of end-stage bladder dysfunction, whereas brachytherapy seed placement was more commonly associated with a devastated outlet. Surgical management for end-stage disease included cystectomy with conduit diversion, conduit diversion alone, and indwelling suprapubic catheter.
CO2 in Supramolecular Chemistry: Preparation of Switchable Supramolecular Polymers

CO2 gas was used to construct novel types of supramolecular polymers. Self-assembling nanostructures 11 and 13 were prepared, which employ both hydrogen bonding and dynamic, thermally reversible carbamate bonds. As precursors, calixarene ureas 1 and 2 were synthesized, which strongly aggregate/dimerize (K(D)>/=10(6) M(-1) per capsule) in apolar solution with the formation of self-assembling capsules 7 and linear polymeric chains 8, respectively, and also possess "CO2-philic" primary amino groups on the periphery. CO2 effectively reacts with molecules 7 and 8 in apolar solvents and cross-links them with the formation of multiple carbamate salt bridges. Oligomeric aggregate 11 and three-dimensional polymeric network 13 were prepared and characterized by 1H and 13C NMR spectroscopy. The morphology of supramolecular gel 13 was studied by scanning electron microscopy. Addition of a competitive solvent destroyed the hydrogen bonding in assembling structures 11 and 13, but did not influence the carbamate linkers; carbamate salts 12 and 14, respectively, were obtained. On the other hand, thermal release of CO2 from 11 and 13 was easily accomplished (1 h, 100 degrees C) while retaining the hydrogen-bonding capsules. Thus, three-dimensional polymeric network 13 was transformed back to linear polymeric chain 8 without breaking up. Encapsulation and storage of solvent molecules by 11 and 13 was demonstrated. This opens the way for switchable materials, which reversibly trap, store, and then release guest molecules. A two-parameter switch and control over hydrogen bonding and CO2-amine adducts was established.
The Predictive Value of Microalbuminuria

An elevated urinary albumin excretion (termed microalbuminuria) has been proposed as a predictor for later development of clinical diabetic nephropathy (hypertension, falling glomerular filtration rate [GFR], and urinary albumin excretion > 300 mg/24 h). However, review of the original reports on the predictability of microalbuminuria revealed a concomitant presence of elevated BP and a propensity to falling GFR. Thus, the predictability of microalbuminuria rests on the added evaluation of BP and GFR. Additional investigation is needed to address the possibility that microalbuminuria and either a rising BP or a falling GFR or both indicates established diabetic nephropathy rather than predicting its development.
Inward Rectifier Potassium Channels in Mammalian Skeletal Muscle Fibers

We combined electrophysiological, optical, immunohistochemical and transgenic expression approaches to study the K inward rectifier current (IKir) in muscle fibers (FDB) from adult mice. Dissociated fibers were stained with the potentiometric dye di-8-ANEPPS and voltage clamped (at VK) using two-microelectrodes. Extracellular [K] ranged from 4 to 96mM; intracellular K content was equilibrated with that of the micropipettes (160mM). Ionic currents other than IKir were eliminated using specific blockers and (for subtraction) IKir was blocked with 1 mM Ba, or by replacing the external solution to one containing TEA. IKir records in response to 100 ms hyperpolarizations showed rapid onsets followed by slow decays which were more prominent at large hyperpolarizations. Voltage changes at the transverse tubular system (TTS) were optically monitored and compared with radial cable model simulations incorporating a constant field/blocking particle approximation of Kir channels. Magnitude, rectification, and [K]-dependence of IKir were well-predicted using an average PKIR value of ∼6x10−6 cm/s while assuming equal density of Kir channels at the surface and TTS membranes. Western blots for Kir2.2 in crude muscle extracts and microsomal preparations reported a single protein band (∼50kD). This band was also found for Kir2.1 in both preparations, but an additional band of ∼55kD was seen in microsomal preparations. Two-photon imaging of muscles immunostained with specific antibodies demonstrated that both Kir isoforms are present at the surface and TTS membranes. Likewise, transfection of muscle fibers with plasmids encoding either EGFP tagged- Kir2.1 or Kir2.2 resulted in overexpression of each isoform in both membranes and an increased IKir up to ∼4-fold those in control fibers. As expected, transfected fibers showed an increased threshold for AP, but unlike controls, they exhibited repetitive APs when stimulated with small long-lasting (∼500ms) current pulses. Supported by NIH/NIAMS AR047664, AR041802, and AR054816.
Thermomechanical Stresses in Copper Interconnect/Low-κ Dielectric Systems

Numerical simulations of thermal stresses in copper interconnect and low-k dielectric systems are carried out. The analyses include two- and three-dimensional finite element modeling of the interconnect structure. Various combinations of metal, oxide and polymer-based low-k dielectric schemes are considered in the simulation. The evolution of stresses and deformation pattern in copper, barrier layers, and the dielectrics are critically assessed.
α-CGRP mRNA levels in motoneurons innervating specific rat muscles

Along with acetylcholine, motoneurons express several neuromodulatory peptides. The most extensively studied of these peptides is calcitonin gene-related peptide (CGRP). CGRP modulates the biochemical, physiological and metabolic properties of skeletal muscle primarily through activation of membrane receptors. Virtually all motor pool contain motoneurons that are immunoreactive for CGRP. The purpose of this study was to determine the proportions of motoneurons that express α-CGRP in motor pools innervating muscles with different motor unit compositions. These include the soleus, extensor digitorum longus, tensor fascia latae and the diaphragm muscles as well as the spinal nucleus of the bulbocavernosus. The spinal nucleus of the bulbocavernosus provides innervation to the bulbocavernosus/levator ani muscle complex and the external anal sphincter muscle. The spinal nucleus of the bulbocavernosus contained the greatest proportion of α-CGRP mRNA-positive motoneurons, followed in descending rank order by the tensor fascia latae, the extensor digitorum longus, the soleus and the diaphragm motor pools. In addition, significant differences between motor pools were observed in the mean relative α-CGRP mRNA level among those motoneurons expressing α-CGRP. The highest mean relative α-CGRP mRNA level was observed in soleus and the extensor digitorum longus motor pools; followed in descending rank order by the tensor fascia latae, the diaphragm and the spinal nucleus of the bulbocavernosus. We have previously shown that muscle contractile inactivity increases the number of motoneurons that express α-CGRP and in the relative mRNA levels. The results of the present study suggest that the proportion of motoneurons within a motor pool that express α-CGRP may be closely related to the contractile activity (i.e. activation history) of the target muscle.
Synthesis and properties of the homo- and heteropolychalcogenide [A(Q5)2]2− family (ATe, QS, Se; ASe, QSe). Crystal structures of (Ph4P)2[Te(S5)2] and β-(Ph4P)2[Se(Se5)2]

Abstract The reaction of Na2Te4 with K2S5 in dimethylformamide in the presence of Ph4PCl gave (Ph4P)2[Te(S5)2] (1). Under the same conditions, the reaction of elemental tellurium with Na2Se5 afforded (Ph4P)2[Te(Se5)2] (II), while β-(Ph4P)2[Se(Se5)2] (III) was made by reacting Na2Se5 with I2. The X-ray powder diffraction studies showed that I, II and III are isostructural. The structures of I and III were determined by X-ray single crystal analysis. The [A(Q5)2]2− anions in the two compounds contain either a square-planar Te2+ in I or Se2+ centre in III, which is situated on an inversion centre and chelated by two S52− or Se52− ligands. The bond distances between the central A2+ and its surrounding four Q atoms are TeS(1) = 2.699(2) A and TeS(5) = 2.752(2) A, or SeSe(1) = 2.653(2) A and SeSe(5) = 2.693(2) A. SS bond distances [av. SS = 2.075(12) A] or SeSe bond distances [av. SeSe = 2.314(13) A] are normal and in good agreement with those found in other polysulphide or polyselenide compounds. The conformation of each AQ5 ring in I and III is very close to a “chair”. The solution UV—vis spectra of DMF solutions for all three compounds are reported.
Construction of isogenic gonococci with variable porin structure: effects on susceptibility to human serum and antibiotics

Summary Protein I (PI) is the most abundant protein on the gonococcal cell surface and besides its porin function it may have important properties contributing to pathogenicity. By allelic exchange using cloned PI genes from FA19 (PIA) and MS11 (PIB) and a selectable marker introduced closely downstream of these genes, we constructed sets of isogenic gonococcal strains that differ only in their PI gene. Analysis revealed that PI has a major effect on stable resistance to normal human serum, and a slight effect on low-level resistance to antibiotics. All PIA/B hybrids were hypersusceptible to serum, suggesting a possible explanation for why such hybrids do not occur in nature.
The Magnetic Resonator Piano: Electronic Augmentation of an Acoustic Grand Piano

Abstract This paper presents the magnetic resonator piano, a hybrid acoustic-electronic instrument extending the traditional grand piano. Sound is produced without loudspeakers using electromagnetic actuators to directly manipulate the piano strings, expanding its vocabulary to include infinite sustain, notes that crescendo from silence, harmonics, and a variety of timbres. A feedback-based approach senses string vibrations from a single pickup on the soundboard, using filters and phase-locked loops to generate signals which reinforce the natural motion of each string. Signal-routing hardware enables coverage of all 88 notes of the piano using a standard digital audio interface. This paper describes the hardware, software, and performing interface of the instrument and presents measurements of amplitude, frequency response, and phase-locked loop performance. Sounds generated by the actuators achieve similar amplitudes to the traditional piano, and while they cannot replicate the rapid attack produced by a...
Ultrastructure of the stomatogastric ganglion neuropil of the crab, Cancer borealis.

The stomatogastric ganglion (STG) of the crab, Cancer borealis, contains the neural networks responsible for rhythmic pattern generation of the foregut. Neuron counts indicate that the STG of C. borealis has 25–26 neurons, 4–5 fewer than that found in lobsters. We describe the ultrastructural features of the ganglion by focusing on those that may be involved in storage, release, or range of action of peptide modulators, including a lacunar system and multiple types of intercellular junctions. In the neuropil, we identify five synaptic profile classes that contain the invertebrate presynaptic apparatus (dense bars, small clear vesicles), two of which also contain dense core (modulator-containing) vesicles. These latter two are comprised of multiple immunocytochemical classes that are not easily distinguished by structural criteria. In addition, we find neurohemal-like profiles that contain primarily dense core vesicles. Our finding that multiple profile types in the STG possess modulator-containing vesicles coincides with immunocytochemical results better than do previous ultrastructural studies that report only one such profile type. We show that a single modulatory input, stomatogastric nerve axon 1, makes only classical synapses and not neurohemal-like profiles, although some modulators are found in both these profile types. These data provide the groundwork for understanding the architecture of modulatory input-target interactions and suggest ways that the specificity of modulatory effects within a complex neuropil may be attained. © 1996 Wiley-Liss, Inc.
Interactions of the N-terminal domain of ribosomal protein L11 with thiostrepton and rRNA

Ribosomal protein L11 has two domains: the C-terminal domain (L11-C76) binds rRNA, whereas the N-terminal domain (L11-NTD) may variously interact with elongation factor G, the antibiotic thiostrepton, and rRNA. To begin to quantitate these interactions, L11 from Bacillus stearothermophilus has been overexpressed and its properties compared with those of L11-C76 alone in a fluorescence assay for protein-rRNA binding. The assay relies on 2'-amino-butyryl-pyrene-uridine incorporated in a 58-nucleotide rRNA fragment, which gives approximately 15-fold enhancement when L11 or L11-C76 is bound. Although the pyrene tag weakens protein binding, unbiased protein-RNA association constants were obtained in competition experiments with untagged RNA. It was found that (i) intact B. stearothermophilus L11 binds rRNA with K approximately 1.2 x 10(9) m(-1) in buffers with 0.2 m KCl, about 100-fold tighter than Escherichia coli L11; (ii) the N-terminal domain makes a small, salt-dependent contribution to the overall L11-RNA binding affinity (approximately 8-fold enhancement at 0.2 m KCl), (iii) L11 stimulates thiostrepton binding by 2.3 +/- 0.6 x 10(3)-fold, predicting an overall thiostrepton affinity for the ribosome of approximately 10(9) m(-1), and (iv) the yeast homolog of L11 shows no stimulation of thiostrepton binding. The latter observation resolves the question of why eukaryotes are insensitive to the antibiotic. These measurements also show that it is plausible for thiostrepton to compete directly with EF-G.GDP for binding to the L11-RNA complex, and provide a quantitative basis for further studies of L11 function and thiostrepton mechanism.
Automated perimetry and short wavelength sensitivity in patients with asymmetric intraocular pressures.

Automated visual field testing [white-on-white (W-on-W) perimetry] and perimetry of short wavelength sensitive mechanisms [blue-on-yellow (B-on-Y) perimetry] were conducted in both eyes of patients with large asymmetries in intraocular pressure (IOP) between eyes (average difference =19.9 mm Hg). Overall visual field sensitivity was significantly (P<0.05) depressed in the eyes with higher IOP by an average of 2.33 dB, in spite of the fact that all but two of the eyes with higher IOP demonstrated visual field sensitivities that were within normal limits. None of the eyes with lower IOP were outside of normal sensitivity limits. B-on-Y perimetry revealed similar findings, except that three of the fellow eyes with relatively lower IOP also demonstrated abnormalities. Our results are consistent with the hypothesis that the diffuse loss in visual field sensitivity in glaucoma is related to IOP. In addition, it appears that short wavelength sensitive mechanism may reveal early glaucomatous losses in patients with elevated IOP.
Fixed Costs and Hours Constraints

Hours constraints are typically identified by worker responses to questions asking whether they would prefer a job with more hours and more pay or fewer hours and less pay. Because jobs with different hours but the same rate of pay may be infeasible when there are fixed costs of employment or mandatory overtime premia, the constraint in those cases may be illusory. Cross-section estimates of reported hours constraints are consistent with this model implying that the overall level of hours constraints may exaggerate the extent to which the labor market is characterized by frictions and imperfections.
The Notch Ligand Delta-Like 1 Integrates Inputs from TGFBeta/Activin and Wnt Pathways

Unlike the well-characterized nuclear function of the Notch intracellular domain, it has been difficult to identify a nuclear role for the ligands of Notch. Here we provide evidence for the nuclear function of the Notch ligand Delta-like 1 in colon cancer (CC) cells exposed to butyrate. We demonstrate that the intracellular domain of Delta-like 1 (Dll1icd) augments the activity of Wnt signaling-dependent reporters and that of the promoter of the connective tissue growth factor (CTGF) gene. Data suggest that Dll1icd upregulates CTGF promoter activity through both direct and indirect mechanisms. The direct mechanism is supported by co-immunoprecipitation of endogenous Smad2/3 proteins and Dll1 and by chromatin immunoprecipitation analyses that revealed the occupancy of Dll1icd on CTGF promoter sequences containing a Smad binding element. The indirect upregulation of CTGF expression by Dll1 is likely due to the ability of Dll1icd to increase Wnt signaling, a pathway that targets CTGF. CTGF expression is induced in butyrate-treated CC cells and results from clonal growth assays support a role for CTGF in the cell growth-suppressive role of butyrate. In conclusion, integration of the Notch, Wnt, and TGFbeta/Activin signaling pathways is in part mediated by the interactions of Dll1 with Smad2/3 and Tcf4.
Price Cycles in Markets with Customer Recognition

Given that having bought earlier from a firm reveals something about the customers, the firms can try to use this piece of information by better fitting their market practices with respect to their previous customers. I consider an infinitely lived monopolist selling to a market where demand is composed of overlapping generations of forward-looking consumers. The monopolist can price differently to its previous customers than to its new customers. The new customers can either have chosen not to buy the product in the previous period or be new in the market. The main result is that, without full market coverage, the equilibrium involves cycles in the price being offered to the new customers. The monopolist is worse off than if it could not recognize its previous customers. The impact of durable goods, long-term contracts, and age recognition is also considered.
Effects of Acid Exposure on Natural Resistance and Mortality of Adult Rana pipiens

Acid is a prevalent environmental stressor for North American frogs, and in the last few decades, many aquatic environments have become increasingly acidic (Freda, 1986). The effects of acid exposure on developing frogs have been demonstrated. Acidic pH may decrease sperm motility in Rana pipiens (Schlichter, 1981) and cause high mortality and developmental abnormalities in embryos and tadpoles (Schlichter, 1981; McDonald et al., 1984; Pierce, 1984, 1985; Freda and Dunson, 1985; Bradford et al., 1992). However, lethal effects of low pH on adult frogs are poorly understood. A few studies demonstrated acidic conditions disrupt transport of ions in isolated skin in vitro (Ferreira and Hill, 1982; Lyall et al., 1992; Feder et al., 1993), which at pH below 4–5 may cause death (Boutilier et al., 1992). The relation of stress to immunosuppression is well documented in many vertebrates (Blecha and Kelley, 1981; Regnier and Kelley, 1981; Blecha et al., 1982; Marnila et al., 1995). In addition, amphibians exposed to low pH may experience immunosuppression followed by microbial disease resulting in mortality (Carey, 1993). We previously demonstrated that adult Rana pipiens exposed to pH 5.5 for 10 days experienced high mortality rates (Vatnick et al., 1999). Here, we characterize effects of acid exposure on defense systems of adult R. pipiens. Fifty frogs were purchased from Charles D. Sullivan Co. Inc. (Nashville, TN) and arrived via airmail. These were wild R. pipiens from ponds in the northeastern United States captured by licensed collectors. In our lab, frogs were housed in individual plastic containers with 800–1000 ml of aged tap water (conductance 5 0.366 mohs, Na1 5 0.14 mM , K1 5 0.3 mM, Mg11 5 0.30 mM, and Ca11 5 0.24 mM) and were acclimated at room temperature for at least two days after arrival and prior to the start of any experiment. During experiments, frogs were placed in individual autoclaved containers containing sterilized citrate buffer. Buffers were prepared in 75-liter carboys, using tap water, and each buffer was autoclaved for 1 h. The pH 5.5 buffer was prepared by adding 4.8 mM citric acid anhydride, 9.5 mM sodium hydroxide, and 0.6 mM sodium citrate to 75 liters of tap water. The pH 7.0 buffer was prepared by adding 2.4 mM citric acid anhydride, 4.8
Improving the role of intraventricular antimicrobial agents in the management of meningitis.

Purpose of review The aim is to review the role of intraventricular administration of antimicrobial agents in the treatment of patients with bacterial and fungal meningitis. Recent findings This article discusses indications for intraventricular antimicrobial agents, choice of antibiotics, strategies to monitor pharmacokinetics of central nervous system compartments and unanswered issues for this management approach. Summary Intraventricular administration of antimicrobials may be necessary in certain difficult- to- eradicate central nervous system infections. There is a significant need for clinical trials and management guidelines in this area.
Multigrid methods for saddle point problems: Stokes and Lamé systems

We develop new multigrid methods for a class of saddle point problems that include the Stokes system in fluid flow and the Lame system in linear elasticity as special cases. The new smoothers in the multigrid methods involve optimal preconditioners for the discrete Laplace operator. We prove uniform convergence of the $$W$$ W -cycle algorithm in the energy norm and present numerical results for $$W$$ W -cycle and $$V$$ V -cycle algorithms.
Mechanism and Quantum Mechanical Tunneling Effects on Inner Hydrogen Atom Transfer in Free Base Porphyrin: A Direct ab Initio Dynamics Study

A theoretical study of the mechanism and kinetics of the inner double hydrogen atom-transfer process in free base porphyrin is presented. Our analysis reveals that the stepwise mechanism first requires the porphyrin ring to compress at an approximate cost of 8.7 kcal/mol, followed by transfer of a H atom with an additional energy requirement of 8.2 kcal/mol. Solvent effects were investigated using a dielectric continuum model and found to be small. The forward and reverse rate constants for the hydrogen atom-transfer process of trans-isomer ↔ cis-isomer were calculated using a canonical variational transition-state theory augmented by multidimensional semiclassical tunneling approximations in the temperature range of 200−1000 K. The calculated activation energy of 10.8 kcal/mol in the temperature range of 200−300 K agrees well with the available experimental data. We found that tunneling is significant for both the forward and reverse trans ↔ cis tautomerization processes, especially in the low-temperatur...
Materials Science of the Earth's Interior

This book is a collection of 31 papers on geologic materials and synthetic analogues formed under the high-pressure and/or high-temperature conditions that prevail in the lower crust and the mantle. During the 3-year period 1978–1980, the Japanese government granted roughly $3.5 million for equipment and supplies to several Japanese national universities for the investigations. Scientists of diverse disciplines participated in the program, which was coordinated by the editor of this book, Ichiro Sunagawa (Tohoku University, Japan), an expert on crystal growth. Initially, 40 papers were published in a special issue of a Japanese journal, as the grant reports, and then selected papers were updated and incorporated into this English language volume. The papers are predominantly textbook-style reviews, but some of them present additional new data or interpretations. Three to eight papers are grouped by subject in each of seven chapters.
A CMOS 260 Mbps read channel with EPRML performance

In this paper, the read channel architecture for a 260 Mbps read channel far magnetic recording applications is presented. The read channel uses a 7 pole 2 zero continuous time filter with a 6 bit flash ADC in the analog front end. The ADC samples are further equalized to the PR4 partial response target with a 5 tap fully asymmetric FIR including LMS adaption. Detection is performed with a PR4 Viterbi detector followed by a postprocessor based on a 16/17(0,6/6) modulation code achieving full EPR4 performance over a range of channel densities. The design is implemented in 0.35 /spl mu/m DPTM CMOS and dissipates 1.3 W max at 260 Mbps.
Development of the post-natal growth plate requires intraflagellar transport proteins

In the post-natal growth plate, chondrocytes are arranged in columns parallel to the long axis of the bone. Chondrocytes divide perpendicular to this axis and then move into position one on top of another in a process called "rotation" that maintains columnar organization. Primary cilia are non-motile microtubule base appendages extending from the surface of almost all vertebrate cells. Primary cilia were described on chondrocytes almost 40 years ago but the function of these structures in cartilage biology is not known. Intraflagellar transport (IFT) is the process by which primary cilia are generated and maintained. This study tested the hypothesis that IFT plays an important role in post-natal skeletal development. Kif3a, a subunit of the Kinesin II motor complex, that is required for intraflagellar transport and the formation of cilia, was deleted in mouse chondrocytes via Col2a-Cre-mediated recombination. Disruption of IFT resulted in subsequent depletion of cilia and post-natal dwarfism due to premature loss of the growth plate likely a result of reduced proliferation and accelerated hypertrophic differentiation of chondrocytes. Cell shape and columnar orientation in the growth plate were also disrupted suggesting a defect in the process of rotation. Alterations in chondrocyte rotation were accompanied by disruption of the actin cytoskeleton and alterations in the localization of activated FAK to focal adhesion-like structures on chondrocytes. This is the first report indicating a role for IFT and primary cilia in the development of the post-natal growth plate. The results suggest a model in which IFT/cilia act to maintain the columnar organization of the growth plate via the process of chondrocyte rotation.
On Efficient Assessment of Image-Quality Metrics Based on Linear Model Observers

This paper is motivated by the problem of image-quality assessment using model observers for the purpose of development and optimization of medical imaging systems. Specifically, we present a study regarding the estimation of the receiver operating characteristic (ROC) curve for the observer and associated summary measures. This study evaluates the statistical advantage that may be gained in ROC estimates of observer performance by assuming that the difference of the class means for the observer ratings is known. Such knowledge is frequently available in image-quality studies employing known-location lesion detection tasks together with linear model observers. The study is carried out by introducing parametric point and confidence interval estimators that incorporate a known difference of class means. An evaluation of the new estimators for the area under the ROC curve establishes that a large reduction in statistical variability can be achieved through incorporation of knowledge of the difference of class means. Namely, the mean 95% AUC confidence interval length can be as much as seven times smaller in some cases. We also examine how knowledge of the difference of class means can be advantageously used to compare the areas under two correlated ROC curves, and observe similar gains.
The shape and stability of rotating liquid drops

Equilibrium shapes and stability of rotating drops held together by surface tension are found by computer-aided analysis that uses expansions in finite-element basis functions. Shapes are calculated as extrema of appropriate energies. Stability and relative stability are determined from curvatures of the energy surface in the neighborhood of the extremum. Families of axisymmetric, two-, three-, and four-lobed drop shapes are traced systematically. Bifurcation and turning points are located and the principle of exchange of stabilities is tested. The axisymmetric shapes are stable at low rotation rates but lose stability at the bifurcation to two-lobed shapes. Two-lobed drops isolated with constant angular momentum are stable. The results bear on experiments designed to further those of Plateau (1863).