cssi/SciSciGPT-SciSciNet huggingface dataset:
A finite element method for the generalized Ericksen model of nematic liquid crystals

We consider the generalized Ericksen model of liquid crystals, which is an energy with 8 independent “elastic”constants that depends on two order parameters n (director) and s (variable degree of orientation). In addition, we present a new finite element discretization for this energy, that can handle the degenerate elliptic part without regularization, with the following properties: it is stable and it Γ-converges to the continuous energy. Moreover, it does not require the mesh to be weakly acute (which was an important assumption in our previous work). Furthermore, we include other effects such as weak anchoring (normal and tangential), as well as fully coupled electro-statics with flexo-electric and order-electric effects. We also present several simulations (in 2-D and 3-D) illustrating the effects of the different elastic constants and electric field parameters.
A Brief Review of Spall Failure in Pure and Alloyed Magnesium

The ratio of the yield strength to the density (specific strength) of magnesium and its alloys is relatively high, but cavitation-driven spall failure of these materials occurs at low threshold stresses and strains. The low failure threshold suggests a general susceptibility to catastrophic failure under tension at high rates of deformation. Higher material strength likely prevents such failure, but processing methods to achieve these strengths can introduce potential failure nucleation sites that can make failure more likely—the interplay between matrix strength and nucleation sites remains largely unknown. Here we examine the literature regarding experimental observation of spall failure of pure and alloyed magnesium with a particular emphasis on the trends between grain size and strain rate with respect to the spall failure strength. We then apply an analytical dynamic cavitation model to better understand the role of second phase particles in spall failure. We find that the conventional polycrystalline alloys with micron sized grains have microstructures containing second phase particles that act as failure nucleation sites, diminishing the potential to design against low failure threshold stresses. Additionally, nanocrystalline grained magnesium remains largely unexplored and may potentially offer an avenue for greater dynamic strength.
Decoration of suspended single-walled carbon nanotubes with soft-landed size-selected metal nanoparticles

Abstract We describe a technique to prepare ensembles of neat, unbundled single-walled carbon nanotubes decorated with pure size-filtered metal nanoparticles. Polymer-encased nanotubes are drop-cast on nanoporous transmission electron microscope membrane grids, mounted within a nanoparticle-deposition apparatus, baked in situ to remove the polymer coating, and exposed to a beam of pure size-selected metal nanoparticles. Subsequent electron microscopy imaging reveals the presence of nanoparticles supported by pure suspended single-walled nanotubes. This method is promising for efficient production of prototype chemical and physical devices which require the presence of clean well-defined nanoparticle-nanotube hybrids for characterization, imaging, and applications.
Application of high-throughput plant phenotyping for assessing biophysical traits and drought response in two oak species under controlled environment

Abstract Early plant selection for desirable traits is important in tree improvement programs and sustainable forest management. In this study, we demonstrate the use of image based high-throughput plant phenotyping (HTPP, LemnaTec 3D Scanalyzer, Germany), with Red, Green, Blue (RGB), and hyperspectral cameras, to quantify Quercus bicolor and Quercus prinoides seedlings growth and development [plant height, projected leaf area (LA), plant/canopy width, ConvexHull, and plant aspect ratio], and assess their response to a dry-down period, under controlled environment. HTPP images were validated against low throughput measurements, including gas exchange, leaf spectral properties, and morphological traits. Using HTPP, we recorded significant differences in growth dynamic in examined species, with faster initial growth rate early in the growing season, higher photosynthetic rates, larger LA, and seedling dimension, in Q. bicolor, compared to Q. prinoides. This has ecological implications on species responses to shading and timing of drought stress, as well as their competitive relationship with each other and with other species under changing climate. HTTP showed that both growth and leaf expansion ceased under dry-down treatment. Image derived and measured morphological traits were highly and significantly correlated under both well-watered and dry-down conditions for both species. To obtain meaningful physiological information using spectrometry, we calculated 12 vegetation indices (VIs) from both HTPP and handheld spectrometers. Vogelmann and Maccioni indices had the highest correlations across methods, suggesting their potential use for assessing oak seedlings performance and health. Our results emphasized the importance of VIs ground truthing, since VIs performance can vary significantly between species and treatments. HTPP tools can successfully be used to effectively assess forest seedlings of the two Quercus species, important for early plant selection for forest management purposes and tree improvement programs.
Effect of Stereoregularity on Bulk Properties of Polymers

Information on the effect of stereoregularity on transitions and thermodynamic properties of bulk macromolecular systems has been developed, largely on an empirical basis, as methods for synthesizing and characterizing polymers of differing configurations became available. In this report we shall consider (a) generalizations that are available in this context, and, in particular, (b) the effect of stereoregularity on glass transition phenomena together with a discussion of specific systems.
The Accidental Indexer: Badgett, Nan. Medford, NJ: Information Today, 2015, 224 pp., $39.50, ISBN: 978-1-57387-514-1

The role of the index in digital products has become a subject of heated debate when information professionals gather to formalize standards. Some publishers and authors are under the misguided imp...
Additive Manufacturing for Fabrication of Robotic Components

Additive manufacturing (AM) is a novel materials processing approach to create parts with three-dimensional (3D) geometries...
Location, location, location: the organization and roles of potassium channels in mammalian motoneurons

The spatial and temporal balance of spinal α-motoneuron (αMN) intrinsic membrane conductances underlie the neural output of the final common pathway for motor commands. Although the complete set and precise localization of αMN K+ channels and their respective outward conductances remains unsettled, important K+ channel subtypes have now been documented, including Kv1, Kv2, Kv7, TASK, HCN and SK isoforms. Unique kinetics and gating parameters allow these channels to differentially shape and/or modify αMN firing properties, and recent immunohistochemical localization of K-channel complexes reveals a framework in which their spatial distribution and/or focal clustering within different surface membrane compartments is highly tuned to their physiological function. Moreover, highly evolved regulatory mechanisms enable specific channels to operate over variable levels of αMN activity and contribute to either state-dependent enhancement or diminution of firing. While recent data suggests an additional, non-conducting, role for clustered Kv2.1 channels in the formation of endoplasmic reticulum-plasma membrane (ER-PM) junctions postsynaptic to C-bouton synapses, electrophysiological evidence demonstrates that conducting Kv2.1 channels effectively regulate αMN firing, especially during periods of high activity in which the cholinergic C-boutons are engaged. Intense αMN activity or cell injury rapidly disrupts the clustered organization of Kv2.1 channels in αMNs and further impacts their physiologic role. Thus, αMN K+ channels play a critical regulatory role in motor processing and are potential therapeutic targets for diseases affecting αMN excitability and motor output, including ALS. This article is protected by copyright. All rights reserved.
Pornified: Pornography’s Connection to Long-Term Damage and Violence

Based upon both theory and research, pornography appears to play a major teaching role in the sexual beliefs and behaviors of men, women, and children. As a teacher, it is arousing, rewarding, and modeling. It miseducates about sexuality and relationships. It teaches unhealthy self-esteem, sexual narcissism, sexual entitlement, and relative deprivation. It is a potent drug that is both flexible and fast. It encourages permission-giving beliefs that include that sex is a commodity that we buy and if we can buy it, we can steal it. This makes a natural and potent pathway to sexual violence. Numerous studies show a variety of negative effects in both attitudes and behaviors, but the most troubling is this connection to sexual violence. The messages of pornography damage the providers of sex as well as the users of sex. The continuum of the sexual exploitation industry and the continuum of sexual abuse and violence are seamlessly interconnected.
Cycles of death and rebirth in twenty-first century French horror

This introduction to the special issue on twenty-first century French horror cinema provides a historical overview of the past 20 years of horror film production in France. From the ‘Bee Movies’ la...
On the Power of Pre-Trained Text Representations: Models and Applications in Text Mining

Recent years have witnessed the enormous success of text representation learning in a wide range of text mining tasks. Earlier word embedding learning approaches represent words as fixed low-dimensional vectors to capture their semantics. The word embeddings so learned are used as the input features of task-specific models. Recently, pre-trained language models (PLMs), which learn universal language representations via pre-training Transformer-based neural models on large-scale text corpora, have revolutionized the natural language processing (NLP) field. Such pre-trained representations encode generic linguistic features that can be transferred to almost any text-related applications. PLMs outperform previous task-specific models in many applications as they only need to be fine-tuned on the target corpus instead of being trained from scratch. In this tutorial, we introduce recent advances in pre-trained text embeddings and language models, as well as their applications to a wide range of text mining tasks. Specifically, we first overview a set of recently developed self-supervised and weakly-supervised text embedding methods and pre-trained language models that serve as the fundamentals for downstream tasks. We then present several new methods based on pre-trained text embeddings and language models for various text mining applications such as topic discovery and text classification. We focus on methods that are weakly-supervised, domain-independent, language-agnostic, effective and scalable for mining and discovering structured knowledge from large-scale text corpora. Finally, we demonstrate with real-world datasets how pre-trained text representations help mitigate the human annotation burden and facilitate automatic, accurate and efficient text analyses.
Impact of the COVID-19 pandemic on neuro-oncology outcomes

The Coronavirus disease 2019 (COVID-19) pandemic has uprooted healthcare systems worldwide, disrupting care and increasing dependence on alternative forms of health care delivery. It is yet to be determined how the pandemic affected neuro-oncology patient outcomes, given that the majority of even “elective” neurosurgical oncology procedures are time-sensitive. This study quantifies changes in neuro-oncological care during the height of the pandemic and investigates patient outcomes in 2020 compared to a historical control. We performed a retrospective review of patients with malignant brain tumor diagnoses who were seen at our institution between March 13 and May 1 of 2020 and 2019. Alterations in care, including shift from in-person to telehealth, delays in evaluation and intervention, and treatment modifications were evaluated. These variables were analyzed with respect to brain tumor control and mortality. 112 patients from 2020 to 166 patients from 2019 were included. There was no significant difference in outcomes between the cohorts, despite significantly more treatment delays (p = 0.0160) and use of telehealth (p < 0.0001) in 2020. Patients in 2020 who utilized telehealth visits had significantly more stable tumor control than those who had office visits (p = 0.0124), consistent with appropriate use of in-person visits for patients with progression. Our study showed that use of telehealth and selective alterations in neuro-oncological care during the COVID-19 pandemic did not lead to adverse patient outcomes. This suggests that adaptive physician-led changes were successful and may inform management during the ongoing pandemic, especially with the emergence of the Delta variant.
Remarried Men and Remarried Women: How Are They Different?.

The study of remarriage after divorce has by and large been ignored by family sociologists. Previous studies on remarriage focused primarily on the individual's adjustment to or the aftermath of remarriage. Employing 1972-82 General Social Survey data, 1 use regression techniques to investigate the relationship between socioeconomic variables and the state of remarriage, for divorced men and women. I test the hypotheses that for men, education, occupation and income level are positively related to remarriage, while for women these variables are inversely associated with remarriage. As hypothesized, highly educated divorced women are less likely to be remarried, as are divorced women who are occupationally and financially independent. The important factor for divorced women considering remarriage is whether or not they are working. Divorced men, on the other hand, are likely to be remarried when they are older and have higher incomes. Unexpectedly, education is inversely related to remarriage for divorced men.
Fluorescence detection of biological aerosols

Summary form only given. The application of two-dimensional spectral analysis to microbes and other biological particles suspended in the atmosphere requires laser excitation in the ultraviolet spectral region. Much of the previous study on spectral characterization has been restricted to bulk samples of biological materials. In this study, a KrF excimer laser at 248 nm was used to carefully determine absolute fluorescent cross sections, while a tripled Cr:LiSAF laser, tunable from 265 to 290 nm, was used to obtain excitation-emission matrix (EEM) profiles. The higher intensity of tunable laser sources is critical to investigating biological material in aerosol form.
An Introduction to the Theory of Knowledge: The traditional analysis and the Gettier problem

In the last chapter we considered the view that knowledge is epistemically justified true belief. In this chapter, we shall consider some counter-examples to the justified true belief (JTB) account and consider some attempts to repair the definition of knowledge in light of these examples. The objection we shall first consider was made prominent by Edmund Gettier in his brief, yet famous, 1963 essay “Is Justified True Belief Knowledge.” The difficulty for the traditional account to which he calls our attention has become known as “the Gettier Problem.” Since 1963, it has received a great deal of attention in epistemological circles and there have been a great many attempts to solve it. It would be fair to say, however, that there remains no widely accepted solution. Many of the attempted solutions are quite ingenious and many are quite complicated and difficult to evaluate. In this chapter we shall have to content ourselves with considering some very simple proposals. The solutions we shall consider are fairly early attempts to solve the problem, solutions that appeared within ten years of Gettier's original essay. None of them are adequate, but the ways in which they fail are instructive and many of the more promising attempted solutions involve refinements and developments of these simple proposals. The three approaches we shall consider are (1) the No False Grounds approach, (2) the Defeasibility approach, and (3) the Causal approach.
SU‐GG‐I‐21: A First‐Order Method for Low‐Dose 4D CBCT Image Reconstruction by Compressed Sensing

Purpose/Objective: In four‐dimensional cone‐beam computed tomography (4DCBCT), there is a trade‐off between the image quality and radiation dose depending on the gantry speed. A higher gantry speed is desirable for short scanning time and low radiation dose, but the image quality is degraded because it leads to reduced number of projections in each individual respiratory phase. The aim of this study is to develop a novel compressed sensing based formalism for high quality 4DCBCT image reconstruction with sparse and potentially low dose projections. Methods/Materials: To maximally utilize the information from the under‐sampled projection data acquired with low mAs protocol, a compressed sensing method with total‐variation is employed. We first solve an unconstrained LASSO (least absolute shrinkage and selection operator) problem based on least‐square criterion regularized by total‐variation. The least‐square criterion reflects the fidelity of the measured line integrals, and the image total‐variation suppresses the noise while preserving the edge information. Then, the LASSO problem is updated and solved repeatedly by Bregman iterations. The performance of the proposed algorithm is demonstrated through a series of phantom experiments, and the results are compared to those of conventional filtered back‐projection (FBP). Results/Discussion: The phantom studies have shown artifacts free images can be obtained with as small as 35 noisy or low current projections per phase, which is adequate for clinical 4DCBCT (7∼10 phases) reconstruction without slowing down the gantry rotation. Additionally, the algorithm converges an order of magnitude faster to the optimal solution than steepest‐decent methods (e.g. POCS) with the same requirement on computer memory. With such small number of projections, the conventional FBP failed to yield meaningful 4DCBCT images.Conclusions: 4DCBCT images are attainable using sparse and low tube current projection data. The method significantly reduces the radiation dose and scanning time as required by conventional 4DCBCT imaging based on FDK technique.
Dynamic Friction Measurements at Sliding Velocities Representative of High-Speed Machining Processes

Understanding high speed machining processes requires knowledge of the dynamic friction response at the tool-workpiece interface, the high strain rate response of the workpiece material and its fracture mechanisms. In this paper, a novel experimental technique, consisting in the independent application of an axial static load and a dynamic torque, is used to investigate time resolved dynamic friction. Shear stress wave propagation along an input bar, pressing statically against an output bar, is analyzed. The quasi-static and kinetic friction coefficients of Ti-6Al-4V sliding against 1080 Steel. Al 6061-T6 sliding against 1080 Steel, and Al 6061-T6 sliding against Al 7075-T6, with various surface characteristics, are investigated. Sliding velocities up to 6.9 m/s are achieved. Surface roughness is varied to understand its role on the frictional response of the sliding interfaces. The dependence of friction coefficient on material strain-rate sensitivity is also assessed. Measured friction coefficients compared well with values reported in the literature using other experimental techniques. The experimental methodology discussed in this article provides a robust method for direct measurement of the quasi-static and dynamic friction coefficients representative of high-speed machining, metal-forming and ballistic penetration processes.
VIRTUAL SIMULATION OF STATEWIDE INTERMODAL FREIGHT TRAFFIC

While freight transportation needs are growing, there is a concern that planning tools available today will be insufficient to provide a systemwide view that is needed to examine all modes of transportation, including intermodal. Many existing tools are either mode oriented or too microscopic in scope. No comprehensive tool considers the level of performance of the total system—an important consideration because of the many interdependencies between resources. In some cases, optimizing just a particular component of the transportation network could result in suboptimization of the entire transportation system. A prototype Virtual Intermodal Transportation System (VITS) is presented; it simulates the movement of freight via all modes on a statewide level. Detailed submodels can be designed to enable planners to analyze the overall impact of decisions made on critical transportation resources such as ports and their connectors. The general processes of building the VITS prototype, the results from a hypothe...
Freshwater reserves of mid-atlantic coast barrier Islands

A multiple regression model was constructed for the purpose of predicting barrier island hydrology from easily measureable island characteristics. The model was developed using data obtained from 17 sites on the Outer Banks of North Carolina. The accuracy of the model for predicting key hydrologic variables was evaluated by statistical and graphic procedures. In general, agreement between observed and predicted values of the hydrologic variables was very good, suggesting that the quantity of potable water at various island sites can be estimated without resorting to extensive field investigations. The model was then applied to Assateague Island, a barrier island located off the coasts of Maryland and Virginia. Results indicate that the original model developed for the Outer Banks may be applied to other barrier islands but that errors involved may necessitate corrections in detailed studies. Correction for bias in predictions for Assateague was shown to be possible with limited field data from surface resistivity surveys.
Facile Reduction of an Unsaturated Chromaborane

The reduction of Cp*2Cr2B4H8 (1) by Na/Hg to yield [Na][Cp*2Cr2B4H8] (2) and its oxidation back to 1 is described. Although 2 has not been crystallographically characterized, changes in the paramag...
Composition of glycosaminoglycans (Mucopolysaccharides) in rabbit renal papillae

Abstract Glycosaminoglycans were isolated from rabbit renal papillae. The crude extract contained sulfated and non-sulfated fractions in approximately equal amounts. Galactosamine and glucosamine were identified as the major amino sugars. Fractionation of the crude material was accomplished by complexing with cetylpyridinium chloride and by column chromatography, paper chromatography, chemical determinations,automatic amino acid analysis and enzymic degradation. The isolated glycosaminoglycans were further characterized in the solid state by infrared spectroscopy and in solution by circular dichroism and the amino acid analyzer. The major constituents of rabbit renal papillary glycosaminoglycans were found to be hyaluronic acid and chondroitin sulfates.
Performance evaluation of a sorbent tube sampling method using short path thermal desorption for volatile organic compounds

Air sampling, using sorbents, thermal desorption and gas chromatography, is a versatile method for identifying and quantifying trace levels of volatile organic compounds (VOCs). Thermal desorption can provide high sensitivity, appropropriate choices of sorbents and method parameters can accommodate a wide range of compounds and high humidity, and automated short-path systems can minimize artifacts, losses and carry-over effects. This study evaluates the performance of a short-path thermal desorption method for 77 VOCs using laboratory and field tests and a dual sorbent system (Tenax GR, Carbosieve SIII). Laboratory tests showed that the method requirements for ambient air sampling were easily achieved for most compounds, e.g., using the average and standard deviation across target compounds, blank emissions were 41 volume) samples of high humidity air. Overall, the method provides excellent performance and satisfactory throughput for many applications.
Presentation and demonstration of a full-color ICVision holographic stereogram display

The ICVision system provides the functional equivalent of a real-time holographic stereogram. Using diffractive optics, the system creates a set of discrete viewing regions called virtual viewing slits. Each pixel of the display fills each viewing slit with different image data. When the images presented in two virtual viewing slits separated by an interoccular distance are filled with stereoscopic pair images, the observer sees a 3D image. The images are computed so that a different stereo pair is presented each time the viewer moves approximately 1 eye pupil diameter (approximately 3 mm), thus providing a series of stereo views. The current embodiment of the ICVision display is realized by integrating a diffractive optical element with a conventional AMLCD. The authors have previously reported on the design of static displays and real-time monochromatic full motion displays. This paper discusses the design details of a full color display. The current system does not require the use of color filters within the AMLCD. A portable version of the real-time color display will be demonstrated at the conference.
Autocorrelation analysis: A new and improved method for branch predictability characterization

Branch predictability characterization not only helps to improve branch prediction but also helps to optimize predicated execution. Branch taken rate and branch transition rate have been proposed to characterize the branch predictability. However, these two metrics may misclassify branches with regular history patterns as hard-to-predict branches, causing an inaccurate and ambiguous view of branch predictability. In this paper, we utilize autocorrelation based analysis of branch history patterns and present two orthogonal metrics Degree of Pattern Irregularity (DPI) and Effective Pattern Length (EPL). Unlike the existing taken rate or transition rate, DPI directly measures the regularity of the patterns in per-address branch history, and hence is more accurate in branch classification. On the other hand, EPL reveals the optimum branch history length for the easy-to-predict branches. The proposed metrics are evaluated with PAs, GAs, and Perceptron branch predictors, and the results show that on average, DPI improves the accuracy of hard-to-predict branch classification by up to 17.7% over taken rate and 15.0% over transition rate for the workloads in this study. It is also able to identify 18.9% more easy-to-predict branches compared with taken rate and 12.8% more compared with transition rate. The proposed metrics are valuable extension to the existing metrics for accurately characterizing branch predictability.
THE BEAST WITHIN: WOMEN IN AMOS OZ'S EARLY FICTION1

Although, as the title indicates, this study focuses on Amos Oz's first collection of short stories, Where the Jackals Howl (Artsot hatan, 1965), it points up characteristics that underlie Amos Oz's later work as well. These characteristics revolve around Oz's fictional presentation of women, as opposed to his literary treatment of men. A gender-conscious analysis of Amos Oz's technique of characterization will not only illuminate a much neglected aspect in the work of one of Israel's leading contemporary authors, but will also highlight the way in which Israeli literature, and literature in general for that matter, is inspired by cultural preconceptions rather than by models of individual people. One of the most striking differences between female and male characters in the stories of Where the Jackals Howl is that females act mostly as sexual beings, whereas males are motivated by both sexual drives and moral considerations. Even the most tempestuous and animalistic male characters (like Matityahu Damkov, the protagonist of the title story) do not lose their human dimension. Consider, for example, the dynamics of "Where the Jackals Howl," which is a story centered around the theme of potential incest. The eccentric Matityahu Damkov is physically attracted to the young and pretty Galila, whom he believes to be his daughter. Despite his strong sexual impulse, Damkov refrains from taking advantage of Galila, who conveniently falls asleep in his room shortly before his planned confession. The story implies that Damkov's paternal responsibility counteracts his lust for the girl. On the other hand, when Galila hears Damkov's secret, she protests that Damkov cannot be her father since he is dark whereas she is blond. Galila rejects the restrictive implications of Damkov's confession and proceeds to seduce the man who may very well be her father: "I am not yours, I'm sure I'm not yours, I'm sure; I'm blond, I may; we may, now, I can be yours. Blond! Come!"2 The paratactic structure of Galila's speech discloses her passion as well as her puerile logic. Her rejection of Damkov's suggestion is emotional, and it clearly lacks convincing factual evidence. The difference in their coloring serves to undermine rather than strengthen her argument, since it is obvious that Galila's fair hair constitutes no real proof against Damkov's possible paternity.
GLUCOSE CONCENTRATION AND INSULIN DOSE-RESPONSE CURVES USING RAT FAT TISSUE IN VITRO.

SummaryA pooled design for adipose tissue bioassay measuring 14CO2 production permitted an index of precision of 0.041-0.091. Comparison of dose-response curves at various glucose concentrations from 25 to 300 mg%, showed very similar classical sigmoid-shaped curves, with similar slopes. The insulin sensitivity of rat epididymal fat, in terms of the oxidation of glucose-1-14C to 14CO2, is independent of glucose concentration (25-300 mg%).We are very grateful to Ruth Miller and Lindsay Fiske for expert technical assistance.
Transparency of One-Handed Amer-Ind Hand Signals to Nonfamiliar Viewers

Thirty non-brain-damaged adults viewed 104 videotaped Amer-Ind hand signals. The majority of these hand signals were produced with one hand; 60 originally one-handed gestures and 31 left-hand adapt...
Projections of physiologically characterized globular bushy cell axons from the cochlear nucleus of the cat

We made intraaxonal recordings from 30 individual globular bushy cell axons in the trapezoid body of the cat using HRP-filled glass microelectrodes. With subsequent HRP injection, we determined their axonal projection patterns. For cells with characteristic frequencies (CFs) above 3 kHz, short-tone peristimulus time histograms (PSTHs) at CF were typically primarylike at low tone intensities and primarylike with notch (PLN) or onset with low sustained activity (OL) at higher stimulus levels. Cells with CFs between 1 and 3 kHz showed the same response features with the spikes in the sustained region of the response phase-locked to the stimulus tone. Cells with CFs below 1 kHz showed phase-locked PSTHs with exceptionally high levels of synchrony compared to eighth nerve fibers with comparable CFs. This exceptional phase-locking was also noted when cells with CFs of 1-3 kHz were presented with tones below 1 kHz. Although the globular bushy cell axons were not completely filled from the soma of origin to terminal fields in the contralateral brainstem, a number of consistent anatomical features were distinguished in the population. All but one of the myelinated axons crossed the midline in the middle, large fiber component of the trapezoid body. Ipsilaterally, the axon always gave off from one to four collateral branches whose major targets were the posterior periolivary nucleus (PPO) and the lateral nucleus of the trapezoid body (LNTB). Minor termination sites for ipsilateral collateral branches were the dorsolateral periolivary nucleus (DLPO) and the lateral superior olive (LSO). Contralaterally the axon gave rise to one or two calyces of Held in the medial nucleus of the trapezoid body (MNTB). Three other major collateral branches arose from the contralateral axon and innervated a consistent set of areas. One headed caudally to innervate an area just ventromedial to the facial nucleus. Another followed the sixth nerve dorsally to innervate the dorsomedial periolivary nucleus (DMPO). A third collateral headed rostrally toward the ventral nucleus of the lateral lemniscus (VNLL), giving off occasional small sidebranches. Although each injected axon gave rise to a collateral that innervated the MNTB, it did not necessarily give rise to all three of the other collateral branches.
The importance of subchondral bone in osteoarthrosis

This article reviews evidence that subchondral bone plays a role in the degeneration of cartilage in osteoarthrosis. Whether the bony changes precede the cartilage degeneration remains unproven but may best be considered necessary for progression of the disease. Epidemiologic studies clearly show increasing subchondral sclerosis with disease progression. Recent evidence demonstrates specific architectural changes in the subchondral trabecular bone in osteoarthrosis that are consistent with an acceleration of bone turnover, which appears to be a part of the pathophysiologic process in progression of the disease. The now well-documented acceleration of bone turnover in osteoarthrosis decreases the stiffness of the bone as a material, but because of structural modifications in both trabecular bone (i.e., increased trabecular number and reduced separation) and subchondral bone (i.e., increased plate thickness), the stiffness (rigidity) of the structure as a whole undoubtedly increases. There is no evidence that growth factors, cytokines, or enzymes play any role in the bony changes associated with the disease, other than as the naturally occurring sequelae of normal bone remodeling processes.
Economies of scale and density in local telephone networks

Abstract The production structure of local telephone networks is analyzed with a translog cost function estimated with cross-sectional data on a sample of 44 small local exchange companies (LECs). The output vector includes the number of stations served and the service territory area. Economies of scale are exhausted beyond 992 stations with growth through territorial expansion. The threshold for expansion through densification is 51,053 stations. These results suggest that the optimal LEC's size is small, and that competition may be the most efficient form of production organization for medium to large markets in rural and low-density urban settings.
Effect of Hydrophobic Peptide Sequence upon Peptide-Dependent Acceleration of Lipid Flip-Flop

The asymmetric distribution of different lipid species in the inner and outer half of the bilayer is an important feature of many natural membranes. Certain transmembrane (TM) helix-forming peptides are known to increase the transverse diffusion (flip-flop) of lipids and can break down lipid asymmetry. We have investigated the dependence of peptide enhanced flip-flop upon TM helix sequence in order to try to understand the mechanism by which this occurs.The movement of a fluorescent phosphatidylcholine analog (6-NBD-PC) from the outer to inner leaflet was used to measure the influence of different model TM helices on the natural flip-flop rate of model membranes. The most hydrophobic TM peptides had very little or no effect upon flip-flop rate. Preliminary results indicate that for TM peptides of comparable length, a reduction of hydrophobicity increases the lipid flip-flop rate. The lipid flip-flop rate was most markedly increased when an Asp residue was introduced near the center of a highly hydrophobic sequence. The flip-flop was greatly accelerated when the Asp residue was protonated and the peptide was in a TM configuration but accelerated the most when the Asp residue was deprotonated and the peptide resided on the bilayer surface. Although certain pore forming peptides have been shown to accelerate flip-flop, no pore formation was detected for the peptides used in our studies. We conclude that perturbation of lipid packing is a possible mechanism by which hydrophobic helices accelerate flip-flop, while pore formation is unlikely to be a universal mechanism for accelerating flip-flop.
Interactions of HIV and methamphetamine: cellular and molecular mechanisms of toxicity potentiation.

Methamphetamine (METH) is a highly addictive psychostimulant drug, whose abuse has reached epidemic proportions worldwide. METH use is disproportionally represented among populations at high risks for developing HIV infection or who are already infected with the virus. Psychostimulant abuse has been reported to exacerbate the cognitive deficits and neurodegenerative abnormalities observed in HIV-positive patients. Thus, the purpose of the present paper is to review the clinical and basic observations that METH potentiates the adverse effects of HIV infection. An additional purpose is to provide a synthesis of the cellular and molecular mechanisms that might be responsible for the increased toxicity observed in co-morbid patients. The reviewed data indicate that METH and HIV proteins, including gp 120, gp 41, Tat, Vpr and Nef, converge on various caspase-dependent death pathways to cause neuronal apoptosis. The role of reactive microgliosis in METH- and in HIV-induced toxicity is also discussed.
A method and fortran program for the computerized reconstruction of three-dimensional objects from serial sections

Abstract Three-dimensional objects can be reconstructed automatically from sets of serial sections by using a suitable algorithm. For two-phase systems it is sufficient to match phase boundary loops between adjacent sections. When all possible neighboring pairs of sections have been compared in this manner, the bounding surfaces of the object are described by sets of triangular and nonplanar quadrilateral patches.
Correlation between cytochrome oxidase staining and the uptake and laminar distribution of tritiated aspartate, glutamate, γ-aminobutyrate and glycine in the striate cortex of the squirrel monkey

The cellular uptake and laminar distribution of tritium-labeled gamma-aminobutyrate, aspartate, glutamate and glycine were examined in the primary visual cortex of squirrel monkeys. The purpose was to correlate the distribution of these labeled neurons with their level of cytochrome oxidase activity, particularly in laminae II-III (puffs) and adjacent non-puff regions. In general, tritium-labeled neurons that had either high or low levels of cytochrome oxidase activity were present in all laminae with each amino acid tested; however, their density varied between laminae and with the amino acid injected. Specifically, in laminae II-III, very few neurons were labelled with either of the putative excitatory amino acids (aspartate and glutamate). An increased uptake for both was observed in lamina IVC, with the greatest increase for each occurring in laminae V and VI. Significantly more neurons in each lamina were labeled with the putative inhibitory transmitters (gamma-aminobutyrate and glycine) than with either aspartate or glutamate. gamma-Aminobutyrate-labeled neurons were more prevalent in lamina II than III, and an increase in labeling was observed in laminae IV-VI, with the most prominent increase found in laminae V and VI. Glycine-labeled neurons were larger, more uniformly distributed and more abundant throughout all cortical laminae than those labeled with the other amino acids. Significantly more gamma-aminobutyrate- and glycine-labeled neurons were found in the puff regions than in the non-puff areas. No difference was found between puff and non-puff regions for the tritium-labeled leucine controls. Labeled neurons included stellate, fusiform and pyramidal-shaped cells of varying sizes; however, gamma-aminobutyrate-labeled pyramidal cells were not observed outside of the intense injection site. Large glycine-labeled cytochrome-oxidase-reactive pyramidal cells (24-32 micron in diameter) were present at the boundary between laminae V and VI. In addition, a row of large glycine-labeled, fusiform neurons were present in lamina IVB. With each amino acid injected, the tritium-labeled neurons that were darkly reactive for cytochrome oxidase were, on average, larger than the tritium-labeled neurons that were only lightly reactive for cytochrome oxidase. Thus, each of the four amino acids tested had its unique pattern of distribution in the primate striate cortex. Whether one or all of them served as neurotransmitter(s) for distinct neuronal groups is beyond the scope of this study. Glycine, in particular, might be used in part or in whole for metabolic purposes.(ABSTRACT TRUNCATED AT 400 WORDS)
Volcanic hotspots on Io - Stability and longitudinal distribution

The first results of a program to determine the longitudinal distribution of volcanic activity on Jupiter's satellite Io are presented. Infrared measurements at 8.7, 10, and 20 micrometers have been taken at a variety of orbital longitudes: strong variation in the 8.7- and 10-micrometer flux with longitude demonstrates that infrared emission arising from volcanic hotspots on Io is strongly concentrated in a few locations. Analysis of these data suggests that the active volcanic regions observed by the Voyager experimenters are still active, particularly the region around the feature known as Loki. Another source of flux, although of somewhat smaller magnitude, is indicated on the opposite hemisphere. If these sources are the only major volcanic centers on Io, then current global heat flow estimates must be revised downward. However, heat flow from as yet unobserved longitudes, hotspots at high latitudes, and conducted heat flow must still be measured.
Using delay discounting to understand impulsive choice in socially anxious individuals: failure to replicate.

Abstract Background and objectives Impulsive choice that follows transient anxiety responses is a potentially important outcome that may underlie maladaptive behavioral patterns that co-occur with high levels of social anxiety. However, little research has examined impulsive choice in relation to social anxiety. Rounds, Beck and Grant (2007; Behavior Research and Therapy , 45, 729–735) found that high social anxiety was associated with impulsive choice using a delay discounting procedure, but only in a non-threatening (control) condition, but several procedural confounds in that study may also explain the findings. The purpose of this study was to replicate Rounds et al. while controlling for potential procedural confounds. Methods High- and low-social anxiety adult college-students with no substance abuse history were assigned randomly to a public speaking condition or a control (silent reading) condition. In the middle of the task, participants completed a measure of delay discounting, which measures impulsive choice. Results Impulsive choice was not influenced by either social anxiety status or experimental condition. Limitations Other aspects of impulsive choice may be more sensitive to transient anxiety and fear. Higher state levels of social anxiety and transient anxiety may be necessary to detect a significant relationship with impulsive choice. Relatively high levels of impulsive responding may only occur in socially anxious individuals with current/historical substance abuse. Conclusions Neither anxiogenic laboratory procedures nor social anxiety status appear to influence impulsive choice as measured by the delay discounting task. Future research might consider examining whether transient anxiety influences other aspects of impulsive choice.
Ibogaine block of the NMDA receptor: in vitro and in vivo studies.

Ibogaine is an hallucinogenic indole alkaloid claimed to have anti-addictive properties. Although its mechanism of action is unknown, binding studies have indicated that the drug may interact with N-methyl-D-aspartate (NMDA) receptors. We further investigated the nature of the interaction between ibogaine and NMDA receptors in voltage clamp and binding studies, and sought to confirm that the drug has NMDA receptor blocking activity in vivo. In whole-cell recordings from cultured rat hippocampal neurons, ibogaine caused a slow, concentration-dependent block of NMDA-induced currents (IC50, 3.1 microM at -60 mV). In contrast, ibogaine failed to affect either kainate- or gamma-aminobutyric acid-evoked currents. The blockade of NMDA currents was use- and voltage-dependent, and the long lasting ibogaine block could be occluded by co-application of Mg2+. Ibogaine also inhibited equilibrium [3H]dizocilpine binding to NMDA receptors in rat forebrain membranes (IC50, 3.2 microM). We conclude that ibogaine is an open channel NMDA receptor antagonist. Administration of ibogaine to mice resulted in complete protection in the maximal electroshock test (ED50, 31 mg/kg, i.p.) and partial protection against NMDA-induced lethality, confirming that ibogaine can block NMDA receptors in vivo.
Velocity Constants for Ultrasonic Stress Measurement in Prestressing Tendons

Abstract There is currently widespread use of high-strength steel tendons for prestressing and post-tensioning of concrete structures and as suspension cables for long-span bridges. Tendons normally consist of one or more seven-wire, helically wound steel strands or solid rods. There are more than 130,000 prestressed bridges in the United States that contain these tendons, and approximately 3,000 new bridges are constructed each year. The prestressing tendons are critical structural elements because the forces in the tendons counteract tensile stresses in the concrete that result from loads acting on a bridge. The tendons are frequently inaccessible for visual inspections and there is currently no accepted nondestructive evaluation technique to assess the condition of these tendons. The goal of this research is to examine ultrasonic stress measurement techniques for the condition assessment of prestressing tendons. This information could be used to compare the actual force in the tendon with its design va...
Preparation variables in nickel catalysts

Abstract Nickel-on-silica catalysts were prepared by the homogeneous precipitation of slowly decomposing urea. After reduction the crystallite size distribution (CSD) of the nickel was determined from magnetic measurements. This technique was found to give very narrow CSDs and is much more reproducible than conventional impregnation methods. The nickel loading may be controlled by the solution concentrations and time of precipitation but higher values lead to broader distributions. The amount of reduced nickel is a function of the hydrogen flow rate and time, but these factors do not influence the CSD. Increasing reduction temperatures produce broader CSDs. Calcination has no effect on the resulting CSDs, nor does passivation in air after reduction. The uniform and stable crystallites resulting from this method are a consequence of the precipitation of nickel hydrosilicate homogeneously over the silica surface. This compound reduces slowly so that the metal does not sinter during reduction and small, uniform crystallites are produced.