cssi/SciSciGPT-SciSciNet huggingface dataset:
“Characteristics and stability of sensorimotor activity driven by isolated-muscle group activation in a human with tetraplegia”

ABSTRACT The topography and temporal stability of movement representations in sensorimotor cortex underlie the quality and durability of neural decoders for brain machine interface (BMI) technology. While single- and multi-unit activity (SUA and MUA) in sensorimotor cortex has been used to characterize the layout of the sensorimotor map, quantifying its stability has not been done outside of injury or targeted interventions. Here we aimed to characterize 1) the bilateral sensorimotor body map associated to isolated muscle group contractions and 2) the stability of multiunit firing responses for a single muscle (the extensor carpi radialis, ECR) over short (minutes) and long (days) time intervals. We concurrently recorded surface electromyograms (EMG) and MUA in a participant with incomplete high-spinal-cord injury as he executed (or attempted to execute) different metronome-paced, isolated muscle group contractions. Furthermore, for 8 recording sessions over 2 months, we characterized the sensorimotor map associated to ECR motions both within and across sessions. For each measurement period, we compared the stability of somatotopy (defined by the number of the channels on which a response was consistently detected) and firing pattern stability for each responsive channel. Stability was calculated for each channel in peri-EMG or peri-cue windows using both mean MUA firing rates and the full time-varying responses (i.e., MUA “shape”). First, we found that cortical representations of isolated group muscle contractions overlapped, even for muscles from disparate body regions such as facial and distal leg muscles; this was the case for both intact and de-efferented muscles, in both motor and sensory channels. Second, the spatial stability of somatotopy significantly changed over the course of both minutes and days, with the consistency between sessions decreasing across longer bouts of time. Firing pattern stabilities showed distinct profiles; mean MUA firing rates became less stable over time whereas MUA shape remained consistent. Interestingly, sensory channels were overall more consistent than motor channels in terms of spatial stability, mean MUA firing rates, and MUA shape. Our findings suggest that the encoding of muscle-driven specific activity in sensorimotor cortex at the level of MUA is redundant and widespread with complex spatial and temporal characteristics. These findings extend our understanding of how sensorimotor cortex represents movements, which could be leveraged for the design of non-traditional BMI approaches.
Improving Small Satellite Communications and Tracking in Deep Space—A Review of the Existing Systems and Technologies With Recommendations for Improvement. Part II: Small Satellite Navigation, Proximity Links, and Communications Link Science

This article is the second of a three-part series in which we present the results of a study exploring concepts for improving communications and tracking capabilities of deep space SmallSats. In Part I, we discussed SmallSat direct-to-earth links and SmallSat communications equipment, and provided recommendations for future work. In Part II, we focus on SmallSat navigation options, Disruption Tolerant Networking (DTN), proximity links, and the use of the communication link for science observations, and we provide recommendations for future work. We have examined both radio and optical navigation options, and considered autonomous and semiautonomous navigation to reduce operational costs for planetary SmallSats. We note that communication link resilience to delay and disruption enhances spacecraft autonomy; therefore, we have provided a discussion of DTN to indicate that using DTN allows for automated data transmission and recovery, therefore, reducing manual operations. SmallSats in deep space may utilize a relay spacecraft for communications with earth or function as a relay for landed and in-orbit assets. We present a detailed examination of relay proximity links and networks where we address both proximity hardware and networking scenarios. The proximity link features that we examine include the network architecture and its relationship to DTN, proximity radios and antennas, communications link performance, and proximity navigation. The use of the communication link for science has been practiced by primary missions in deep space scenarios. (Two examples of past planetary radio science experiments can be found in the following: https://solarsystem.nasa.gov/missions/cassini/mission/spacecraft/cassini-orbiter/radio-science-subsystem/ and https://www.boulder.swri.edu/pkb/ssr/ssr-rex.pdf) Likewise, SmallSats can offer their radio links for radio science investigations. This article provides a brief introduction to radio science and presents the prerequisite features necessary for radio science observations by SmallSats. We conclude with nine recommendations based on the findings of the study. These recommendations are guidelines on the design, implementation, and operation of deep space SmallSat communication links. The adoption of some or all of the guidelines should result in an enhanced communication and tracking capability for the deep space SmallSat missions.
Hardware-Level Thread Migration to Reduce On-Chip Data Movement Via Reinforcement Learning

As the number of processing cores and associated threads in chip multiprocessors (CMPs) continues to scale out, on-chip memory access latency dominates application execution time due to increased data movement. Although tiled CMP architectures with distributed shared caches provide a scalable design, increased physical distance between requesting and responding cores has led to both increased on-chip memory access latency and excess energy consumption. Near data processing is a promising approach that can migrate threads closer to data, however prior hand-engineered rules for fine-grained hardware-level thread migration are either too slow to react to changes in data access patterns, or unable to exploit the large variety of data access patterns. In this article, we propose to use reinforcement learning (RL) to learn relatively complex data access patterns to improve on hardware-level thread migration techniques. By utilizing the recent history of memory access locations as input, each thread learns to recognize the relationship between prior access patterns and future memory access locations. This leads to the unique ability of the proposed technique to make fewer, more effective migrations to intermediate cores that minimize the distance to multiple distinct memory access locations. By allowing a low-overhead RL agent to learn a policy from real interaction with parallel programming benchmarks in a parallel simulator, we show that a migration policy which recognizes more complex data access patterns can be learned. The proposed approach reduces on-chip data movement and energy consumption by an average of 41%, while reducing execution time by 43% when compared to a simple baseline with no thread migration; furthermore, energy consumption and execution time are reduced by an additional 10% when compared to a hand-engineered fine-grained migration policy.
Addressing BBB Heterogeneity: A New Paradigm for Drug Delivery to Brain Tumors

Effective treatments for brain tumors remain one of the most urgent and unmet needs in modern oncology. This is due not only to the presence of the neurovascular unit/blood-brain barrier (NVU/BBB) but also to the heterogeneity of barrier alteration in the case of brain tumors, which results in what is referred to as the blood-tumor barrier (BTB). Herein, we discuss this heterogeneity, how it contributes to the failure of novel pharmaceutical treatment strategies, and why a "whole brain" approach to the treatment of brain tumors might be beneficial. We discuss various methods by which these obstacles might be overcome and assess how these strategies are progressing in the clinic. We believe that by approaching brain tumor treatment from this perspective, a new paradigm for drug delivery to brain tumors might be established.
High-resolution light-field microscopy with patterned illumination

Light-field fluorescence microscopy can record large-scale population activity of neurons expressing genetically-encoded fluorescent indicators within volumes of tissue. Conventional light-field microscopy (LFM) suffers from poor lateral resolution when using wide-field illumination. Here, we demonstrate a structured-illumination light-field microscopy (SI-LFM) modality that enhances spatial resolution over the imaging volume. This modality increases resolution by illuminating sample volume with grating patterns that are invariant over the axial direction. The size of the SI-LFM point-spread-function (PSF) was approximately half the size of the conventional LFM PSF when imaging fluorescent beads. SI-LFM also resolved fine spatial features in lens tissue samples and fixed mouse retina samples. Finally, SI-LFM reported neural activity with approximately three times the signal-to-noise ratio of conventional LFM when imaging live zebrafish expressing a genetically encoded calcium sensor.
Mechanical dewatering and water leaching pretreatment of fresh banagrass, guinea grass, energy cane, and sugar cane: Characterization of fuel properties and byproduct streams

Abstract Tropical biomass feedstock candidates, banagrass ( Pennisetum purpureum × Pennisetum glaucum ), guinea grass ( Panicum maximum ), energy cane ( Saccharum spontaneum ), and sugar cane ( Saccharum officinarum L.) (as reference) were harvested and processed using pressing and leaching techniques to improve fuel properties for thermochemical conversion. Test results are reported that summarize the impacts of treatment methods on fuel properties and provide detailed data on mass and element partitioning between process streams to inform system design. The processed fuels had lower ash contents, improved heating values, higher ash deformation temperatures, and higher volatile matter to fixed carbon ratios than the parent materials. The liquid streams generated by the process were characterized for chemical oxygen demand, sugar content, total solids, total suspended solids, and major and trace elements. At least 20% of the initial fuel dry matter was partitioned to the byproduct liquid streams as total solids under the combined influences of leaching and mechanical processing. Analytical results support the land application of liquids as a nutrient recycling option. Element partitioning between solid and liquid process streams was determined and material and element mass balances were performed. Chemical equilibrium calculations based on the elemental composition of the parent materials and processed fuels and steam gasification conditions predicted substantial reductions in concentrations of K, Cl, S, Na, and Mg in the product gas.
The Demonstration and Solubilization of β-Hydroxy-β-methylglutaryl Coenzyme A Reductase from Rat Liver Microsomes

Abstract A relatively quick and simple assay method for the formation of 14C-mevalonic acid from 3-14C-β-hydroxy-β-methylglutaryl coenzyme A is described. The method has made possible demonstration of this biosynthetic reaction in vitro by a rat liver enzyme system. It has been shown that the reaction is quantitative, assuming only one biologically active isomer of the coenzyme A ester. For enzymatic activity there is an absolute requirement for reduced nicotinamide adenine dinucleotide phosphate as well as the presence of a reduced thiol. The location of the reductase activity has been found to be in the microsomal fraction. The particulate microsomal reductase has been solubilized by preparation of an acetone powder. This solubilization resulted in increased demonstrable activity. The solubilized material exhibited approximately the same requirements for reduction as did the original microsomes.
Kim's Supervenience Argument and the Nature of Total Realizers

: I offer a novel objection to Jaegwon Kim's Supervenience Argument. I argue that the Supervenience Argument relies upon an untenable conception of the base physical properties upon which mental properties are supposed to supervene: the base properties are required to be both ordinary physical/causal properties and also unconditionally sufficient for the properties that they subvene. But these requirements are mutually exclusive; as a result, at least two premises in the Supervenience Argument are false. I argue that this has disruptive consequences both for the reductive position that Kim defends and the non-reductive position that he attacks. Neither side in the debate over the status of functionally conceived mental properties comes out unscathed.
Highly dispersed networks by enhanced redirection

We introduce a class of networks that grow by enhanced redirection. Nodes are introduced sequentially, and each either attaches to a randomly chosen target node with probability $1\ensuremath{-}r$ or to the parent of the target with probability $r$, where $r$ is an increasing function of the degree of the parent. This mechanism leads to highly dispersed networks with unusual properties: (i) existence of multiple macrohubs---nodes whose degree is a finite fraction of the total number of network nodes $N$, (ii) lack of self-averaging, and (iii) anomalous scaling, in which ${N}_{k}$, the number of nodes of degree $k$ scales as ${N}_{k}\ensuremath{\sim}{N}^{\ensuremath{\nu}\ensuremath{-}1}/{k}^{\ensuremath{\nu}}$, with $1l\ensuremath{\nu}l2$.
Monotone Dynamical Systems: An Introduction to the Theory of Competitive and Cooperative Systems

Monotone dynamical systems Stability and convergence Competitive and cooperative differential equations Irreducible cooperative systems Cooperative systems of delay differential equations Nonquasimonotone delay differential equations Quasimonotone systems of parabolic equations A competition model Appendix Bibliography.
On-line adjustment in general multiple linear-quadratic control

An explicit expression of the partial derivatives of the performance indices with respect to the weighting vector is derived in this paper for the general multiple linear-quadratic control. A feedback control scheme is established through an online adjustment of the weighting vector as the system experiences disturbances. >
Contraceptive attitude-behavior consistency in adolescence

Thornburg (1973) suggests that adolescents experience a high level of value-behavior inconsistency compared to individuals in other stages of the lifespan due to engaging in peer-oriented behavioral realms that are contrary to values shared with the parental family. Extending Thornburg's value-behavior inconsistency model to encompass contraceptive attitudes and behavior, it is predicted that contraceptive attitude-behavior inconsistency is prevalent among sexually-active adolescents, and that inconsistency would be greatest when parental and peer contraceptive attitudes are perceived to be incongruent. Analysis of a sample of 167 sexually-active adolescent females ages 13-to-18 indicates that general contraceptive attitudes are consistent with contraceptive use, whereas attitudes toward specific contraceptive methods are unrelated to contraceptive behavior. The data lend support to the predictions of Thornburg's model in that contraceptive attitude-behavior inconsistency is greatest under peer favorable/parent unfavorable and peer unfavorable/parent favorable contraceptive attitude conditions.
Polymorphisms in the Selenoprotein S gene and subclinical cardiovascular disease in the Diabetes Heart Study

Selenoprotein S (SelS) has previously been associated with a range of inflammatory markers, particularly in the context of cardiovascular disease (CVD). The aim of this study was to examine the role of SELS genetic variants in risk for subclinical CVD and mortality in individuals with type 2 diabetes mellitus (T2DM). The association between 10 polymorphisms tagging SELS and coronary (CAC), carotid (CarCP) and abdominal aortic calcified plaque, carotid intima media thickness and other known CVD risk factors was examined in 1220 European Americans from the family-based Diabetes Heart Study. The strongest evidence of association for SELS SNPs was observed for CarCP; rs28665122 (5′ region; β = 0.329, p = 0.044), rs4965814 (intron 5; β = 0.329, p = 0.036), rs28628459 (3′ region; β = 0.331, p = 0.039) and rs7178239 (downstream; β = 0.375, p = 0.016) were all associated. In addition, rs12917258 (intron 5) was associated with CAC (β = −0.230, p = 0.032), and rs4965814, rs28628459 and rs9806366 were all associated with self-reported history of prior CVD (p = 0.020–0.043). These results suggest a potential role for the SELS region in the development subclinical CVD in this sample enriched for T2DM. Further understanding the mechanisms underpinning these relationships may prove important in predicting and managing CVD complications in T2DM.
Prediction of protein-protein association rates from a transition-state theory.

Summary We recently developed a theory for the rates of protein-protein association. The theory is based on the concept of a transition state, which separates the bound state, with numerous short-range interactions but restricted translational and rotational freedom, and the unbound state, with, at most, a small number of interactions but expanded configurational freedom. When not accompanied by large-scale conformational changes, protein-protein association becomes diffusion limited. The association rate is then predicted as k a = k a 0 exp ( − Δ G el ‡ / k B T ) , where Δ G el ‡ is the electrostatic interaction free energy in the transition state, k a 0 is the rate in the absence of electrostatic interactions, and k B T is thermal energy. Here, this transition-state theory is used to predict the association rates of four protein complexes. The predictions for the wild-type complexes and 23 mutants are found to agree closely with experimental data over wide ranges of ionic strength.
Daily life for eight urban gay men with HIV/AIDS.

OBJECTIVE The purpose of this qualitative research study was to gain an understanding of the daily life experiences of eight gay men with HIV/AIDS living alone in New York City. METHOD The participants ranged in age from 25 to 50 years. Data were primarily collected using in-depth personal interviews in 1996 followed by telephone interviews 1 year later. Constant-comparison and thematic analyses were used to identify themes and subthemes. RESULTS Two broad themes with related subthemes were generated from the data. "A Reasonably Stable Base" represented the emotional, physical, and environmental foundation that preexisted or was created as a consequence of living with HIV/AIDS. This theme played a particularly important role in the participants' lives, especially during periods of emotional and physical instability. "Finding and Maintaining Balance" was a second theme that illustrated strategies used for managing and readjusting daily routines, goals, and priorities, as well as how the participants experienced this readjustment process. CONCLUSIONS All of the participants developed their own daily living strategies that were comparable to intervention methods provided in occupational therapy such as energy conservation and work simplification. The findings suggest that occupational therapy practitioners could potentially assist urban gay men with HIV/AIDS with finding and maintaining stability and balance in their daily lives.
Nested multilayered X pinches for generators with mega-ampere current level

A symmetric X pinch configuration that is conducive to using large numbers of wires on ≥1 MA pulsed power generators has been tested at 1 MA. Using an initial configuration of wires before their twisting, similar to nested cylindrical wire arrays, enables a geometrically simple, compact, multilayer wire configuration at the X pinch crossing region. Multilayer X pinches with the same or different materials in the inner and outer wire layers were tested. Optimization resulted in X pinch radiation sources with peak power comparable to the most successful single layer X pinch, but with a compact, single bright X radiation source more reliably obtained using the nested configuration.
The diffusion of gases through metals II-diffusion of hydrogen through aluminium

The only direct attempt to determine the rate of diffusion of hydrogen through solid aluminium, of which we are aware, is described in a paper by Deming and Hendricks, * in which they conclude that aluminium is impermeable to hydrogen at temperatures up to 550° C. Very slow rates of diffusion would not have been detected by the method employed. The solubility of hydrogen in aluminium has been measured by Iwase, Rontgen and Braun, and Rontgen and Moller.§ No solubility was detected in solid aluminium, but molten aluminium dissolves about 0·1 to 0·2 cc of hydrogen per 100 gm of metal at the melting-point, and the solubility increases with temperature.
Breeding Wildlife to Extinction in China

The burgeoning wildlife breeding industry in China escalates wildlife trade by driving consumer demand and poaching. The tiger trade illustrates the issue in this presentation. China's State Forest...
First Report of Ditylenchus dipsaci on Garlic in Minnesota.

In the summer of 2011, two independent garlic samples from Morrison and Dakota counties and in 2012 one garlic sample from Carver county in Minnesota were submitted by commercial growers to the University of Minnesota Plant Disease Clinic for disease analyses. Symptoms of the above-ground plant parts were stunting and chlorosis. Symptoms of bulbs were necrosis, underdevelopment, and distortion. Upon microscopic examination, phytonematodes exuded into the surrounding water droplet. Nematodes were present in the protective leaves, abscission zone, and cloves in all submitted bulbs (n = 18) for analyses. Morphometric examination of females, males, and juveniles determined that they were Ditylenchus dipsaci. Nematodes extracted from garlic cloves were fixed in TAF (97 ml formalin [40%], 2 ml triethanolamine, and 91 ml dH2O). Morphological observations and measurements were made under an Olympus BX51 microscope equipped with a Nomarski differential interference contrast. Female (n = 6) measurements were: L = 1...
Using the personals ads: a deviant activity?

This article uses ethnographic data to examine the process of using the personals ads and finds it to be a deviant activity. People using the personals engage in deviance disavowal, telling only close friends, if anyone, about the behavior, and needing such friends to help in redefining the behavior as acceptable. Nevertheless, many of the people who use these ads are of a high enough status that their use suggests the possibility of the legitimation of the ads.
New dimensions in color perception

Colors are generally ordered in three dimensions, with hue and saturation as polar coordinates of a color circle, and brightness as the third dimension. Intuitively, lines of constant hue (but variable saturation) in such a color space should converge on an achromatic point devoid of hue. However, in new experiments by Ekroll et al. using colored patches in colored surrounds, constant hue lines converge not on 'gray' but on the surround color. This paradoxical observation suggests that the standard three-dimensional conception of perceived color is inadequate.
4-(Fluoromethyl)phenyl Phosphate Acts as a Mechanism-based Inhibitor of Calcineurin

The compound 4-(fluoromethyl)phenyl phosphate (FMPP), recently shown to be a mechanism-based inhibitor of prostatic acid phosphatase (Myers, J. K., and Widlanski, T. S.(1993) Science 262, 1451-1453), was examined for its effect on calcineurin. This compound inhibits calcineurin in a time-dependent, first order manner. Inactivation with [3H]FMPP led to a specific labeling of the catalytic subunit with a stoichiometry of 0.75 mol of label/mol of protein. A related substrate, 4-methylphenyl phosphate, is able to protect calcineurin from FMPP-mediated inhibition. Scavenging nucleophiles, such as cysteine, do not affect the rate of inhibition when included in the reaction. In addition, extensive dialysis indicates that inhibition is essentially irreversible. These results demonstrate that FMPP inactivates calcineurin in a mechanism-based fashion by forming a covalent adduct with calcineurin A, the catalytic subunit.
CODACHROME: a system for creating interactive electronic jewelry for children

CodaChrome is an interactive system for children to design and create their own electronic jewelry using both digital and traditional craft materials. Specifically, it describes the software and hardware components used for the jewelry design activity, and the two design sessions where children used the CodaChrome system to create their electronic jewelry out of a collection of beads and stones, and out of electronic materials like circuit boards, LEDs and wires. They programmed the animated color sequences (color patterns) using a custom made software environment that provides graphical tools (i.e. color palettes) and widgets like a timeline to facilitate the task.
Newspaper Coverage of the U.S. Labor Movement: The Case of Anti-Union Firings 1:

If the news media covered anti-labor events such as anti-union fir ings, the publicity potentially could galvanize community support for workers' unionization efforts. But, when workers are illegal...
Resensitizing Men: A Male Perspective

Most of us accept that men are conditioned to behave as though they are always dominant, achieving, tough, and unsentimental and that, as a consequence, they erect elaborate defenses against feelings or thoughts that threaten to negate this self-concept. As therapists we often experience how difficult it is to move men off the cognitive level and info more effective places where they can experience their self-division and alienation. This article encourages counselors to appreciate the threats involved for men in becoming more intimate with themselves. In addition, it suggests some ways to facilitate this process, and pinpoints specific concerns and thoughts that male clients may have as they become more deeply involved in therapy.
Magnitude and characteristics of arthritis and other rheumatic conditions on ambulatory medical care visits, United States, 1997.

Objective To describe ambulatory medical care utilization, defined to exclude injury-related visits, for persons with arthritis and other rheumatic conditions. Methods National estimates, rates, and other characteristics of ambulatory care visits were calculated from a national sample of patient visits to physician offices and acute care hospital outpatient and emergency departments. Results An estimated 36.5 million ambulatory care visits were related to arthritis and other rheumatic conditions. Visit rates increased with age and, overall, were twice as high among women as men. Rates of visits by race varied by ambulatory care setting. Soft tissue disorders (9.3 million), osteoarthritis (7.1 million), nonspecific joint pain/effusion (7.0 million), and rheumatoid arthritis (3.9 million) were the most common diagnoses. Conclusions Arthritis and other rheumatic conditions account for about as many ambulatory care visits as cardiovascular disease or essential hypertension. These visits serve as excellent opportunities to counsel patients regarding prevention messages for arthritis.
Learning iteration recursion from examples

Recursion is basic to computer science, whether it is conceived of abstractly as a mathematical concept or concretely as a programming technique. Three experiments were carried out on learning iteration and recursion. The first involved learning to compute mathematical functions, such as the factorial, from worked out examples. The results suggest the subjects are quite able to induce a computational procedure for both iterative and recursive functions. Furthermore, prior work with iterative examples does not seem to facilitate subsequent learning of recursive procedures, nor does prior work with recursive examples facilitate subsequent learning of iterative procedures. The second experiment studied the extent to which people trained only with recursive examples are able to transfer their knowledge to compute other similar recursive mathematical functions stated in an abstract form. It turned out that subjects who transferred to abstractly stated problems performed somewhat worse than they had performed previously when given examples. However, they did far better than a control group trained only with an abstract description of recursion. The third experiment involved comprehension of iterative and recursive Pascal programs. Comprehension of the iterative program was not affected by prior experience with the recursive version of the same program. Comprehension of the recursive version was only weakly affected by prior experience with the iterative version.
A Photometric Study of the Color of Healthy Gingiva

An apparatus was developed that was found suitable for measuring gingival color in terms of reflectance at 6328 A. A total of 445 readings were taken on 95 Caucasian subjects in order to determine certain properties of healthy gingival color. It was determined that: 1. Healthy adult gingival color ranged in reflectance from 17% to 45% of the magnesium oxide standard, with a mean of 32%. 2. Gingival color of children was lighter than that of adults. The reflectance of children's gingiva ranged from 31% to 43%, with a mean of 35%. 3. Gingival color did not vary with the sex of the individual. 4. Gingival color was lighter in individuals with blonde hair than in individuals with brown hair. 5. Gingival color was darker in individuals with darker eye color. 6. Gingival color was lighter in individuals with geographic origins that are commonly related to lighter complexions. 7. Gingival color did not vary with age, within the adult range covered in this study. 8. Gingival color did not vary with the following physiological and physical factors: menstrual period, use of oral contraceptives, smoking habits, moistness or dryness of the gingiva, which side was measured, time of day, or time after toothbrushing, smoking a cigarette, eating an apple, or drinking a hot beverage.
Nonoperative Management of Rectal Cancer: Current Perspectives

While surgery plays a central role in the management of all stages of operable rectal cancer, nonoperative approaches for both early-stage and locally advanced disease are being explored. This comprehensive review summarizes the current literature regarding the nonoperative management of rectal cancer and discusses caveats and controversies to such an approach.
Early induction of rat brain tryptophan hydroxylase (TPH) mRNA following parachlorophenylalanine (PCPA) treatment

Abstract Tryptophan hydroxylase (TPH) is the first and presumably rate-limiting enzyme in serotonin (5-HT) biosynthesis. End-product inhibition of rate-limiting enzymes is common and 5-HT is known to inhibit TPH activity in vivo. However, it is not known whether levels of 5-HT could also be involved in the regulation of the TPH gene. In order to determine whether TPH gene regulation is dependent on the 5-HT concentration, 5-HT levels were reduced by the administration of parachlorophenylalanine (PCPA). PCPA is a potent, specific and irreversible inhibitor of TPH activity which drastically reduces 5-HT concentration in the 5-HT neurons and terminals. When PCPA was administered, TPH activity in both cell bodies and nerve terminal areas, was reduced to 10% of control values and recovered to the control levels by day 7 in raphe nucleus, and within 14 days in the hypothalamus. In serotonergic terminal areas, 5-HT could not be detected immunohistochemically at day 1, but slowly recovered within 2 weeks. At all time points examined, aromatic l -amino acid decarboxylase (AADC) levels were not changed either in the cell body or terminal areas. The steady state levels of TPH mRNA estimated by in situ hybridization increased at day 1 and returned to control levels by day 4. AADC message levels were not altered throughout the periods. These data suggest that a decrease in 5-HT concentration may lead to an up-regulation of TPH gene transcription, by an, as yet, unknown mechanism. Taken together, our results suggest that feedback control of the rate-limiting enzyme, TPH, may occur not only through changes in enzyme activity, but also through changes in gene transcription (Preliminary results were published by Park et al. [Soc. Neurosci. Abstr., 17 (1991) 1176] at the Neuroscience Meeting in 1991).
Diffraction from Polymerized Membranes

Flexible polymerized membranes in a good solvent are expected to exhibit a remarkable low-temperature flat phase, characterized by a diverging bending rigidity, vanishing elastic constants, and large fluctuations both parallel and perpendicular to the surface. A theory of the equilibrium structure factor provides a good fit to extensive molecular dynamics simulations of simplified "tethered surface" models of these materials. These results show how information about the size, thickness, and internal structure of polymerized membranes can be extracted from diffraction experiments.
Mechanisms of same/different concept learning in primates and avians

Mechanisms of same/different concept learning by rhesus monkeys, capuchin monkeys, and pigeons were studied in terms of how these species learned the task (e.g., item-specific learning versus relational learning) and how rapidly they learned the abstract concept, as the training set size was doubled. They had similar displays, training stimuli, test stimuli, and contingencies. The monkey species learned the abstract concept at similar rates and more rapidly than pigeons, thus showing a quantitative difference across species. All species eventually showed full concept learning (novel-stimulus transfer equivalent to baseline: 128-item set size for monkeys; 256-item set for pigeons), thus showing a qualitative similarity across species. Issues of stimulus regularity/symmetry, generalization from item pairs, and familiarity processing were not considered to be major factors in the final performances, converging on the conclusion that these species were increasingly controlled by the sample-test relationship (i.e., relational processing) leading to full abstract-concept learning.
A Comparison of the Influences of Verbal-Successive and Spatial-Simultaneous Factors on Achieving Readers in Fourth and Fifth Grade A Multivariate Correlational Study

The concepts of spatial-simultaneous and verbal-successive processing are explored, and their relevance to reading quantified. In simultaneous processing, perceived stimuli are totally surveyable or globally available at one point in time, whereas in successive processing information is presented consecutively in serial order as in speech. Comparison of the two systems of processing makes it possible to distinguish the reader with the ability to convert the consecutive presentation of elements of incoming information into a new quality of simultaneous perceptibility from one who may have a good understanding of the meaning of individual words but not grasp the meaning of the thought as a whole. The results of this investigation confirm previous studies that in grades 4 and 5 both forms of processing, spatial and verbal, are important in normally achieving children. The relative influence of the two systems at different ages and achievement levels, as well as implications for training, is discussed.
A direct hydrogen-1, carbon-13, and nitrogen-15 NMR study of lutetium(III)-isothiocyanate complexation in aqueous solvent mixtures

A direct, low-temperature hydrogen-1, carbon-13, and nitrogen-15 nuclear magnetic resonance study of lutetium(III)-isothiocyanate complex formation in aqueous solvent mixtures has been completed. At −100°C to −120°C in water-acetone-Freon mixtures, ligand exchange is slowed sufficiently to permit the observation of separate1H,13C, and15N NMR signals for coordinated and free water and isothiocyanate ions. In the13C and15N spectra of NCS−, resonance signals for five complexes are observed over the range of concentrations studied. The13C chemical shifts of complexed NCS− varied from −0.5 ppm to −3 ppm from that of free anion. For the same complexes, the15N chemical shifts from free anion were about −11 ppm to −15 ppm. The magnitude and sign of the15N chemical shifts identified the nitrogen atom as the binding site in NCS−. The concentration dependence of the13C and15N signal areas, and estimates of the fraction of anion bound at each NCS−:Lu3+ mole ratio, were consistent with the formation of [(H2O)5Lu(NCS)]2+ through [(H2O)Lu(NCS)5]2−. Although proton and/or ligand exchange and the resulting bulk-coordinated signal overlap prevented accurate hydration number measurements, a good qualitative correlation of the water1H NMR spectral results with those of13C and15N was possible.
Direct visualization of microstructural deformation processes in polyethylene

The deformation morphology of high density polyethylene was investigated by electron microscopy of oriented thin films. A melt-drawing process was used to produce chain axis oriented and planar textured thin film, which was subsequently deformedin situ at room temperature in a scanning transmission electron microscope. Both as-drawn and annealed films were studied. Deformation along the orientation direction is initially accomodated by the interlamellar regions, which cavitate and form microfibres. For annealed films it is possible to directly observe strain-induced crystallization at about 300% strain in the fibrils. With increased deformation, suitably oriented lamellar crystals deform by two clearly visualized chain slip systems: {1 0 0}, 〈0 0 1〉 and {0 1 0}, 〈0 0 1〉. Thesec axis shear processes could be further distinguished as fine slip or as block shear. Still higher deformation causes more breakup of blocks by shear; when the block size is less than some critical size, the blocks decrystallize. The deformation leads toward a fibrillar morphology consisting of oriented crystals from crystallized amorphous material at high elongations, crystal blocks broken out of lamellae, and chains drawn out of lamellae and recrystallized. The deformation behaviour of the as-drawn films is somewhat different from that of the annealed films. Initially as for the annealed films the lamellae are separated with increasing strain as the interlamellar regions are deformed but there is less voiding. Higher deformation causes the lamellae in the as-drawn films to shear apart at significantly lower strain levels (50% as opposed to 300%) than in the annealed films. At about 100% deformation, the as-drawn film no longer has a recognizable lamellar structure. Although generalization is tempered by the simplicity of this model texture, these deformation results are highly relevant to the current microstructural understanding of lamellar deformation in different regions of a spherulite, to the morphology of commercial extruded and blown films, and to specially prepared textured polymers, such as rolled and annealed films or capillary melt flow and solidification methods which can produce texture approaching that of a single crystal.
Theoretical calculations of methylquinolinium tricyanoquinodimethanide (CH3Q–3CNQ) using a solvation model

Abstract To better understand the unimolecular electrical rectification in γ-(hexadecyl)quinolinium tricyanoquinodimethanide (C16H33Q–3CNQ), γ-(methyl)quinolinium tricyanoquino-dimethanide (CH3Q–3CNQ) was studied by semi-empirical SM5.4/AM1 and ab initio (SCRF/SCIPCM/B3LYP/6-31G*) solvation models. DFT single-point calculations agree well with the semi-empirical calculations. CH3Q–3CNQ in acetonitrile may exist in both trans and cis zwitterionic forms; the trans form is 3.1 kcal mol−1 more stable than the cis form, and separated from it by a 11.3 kcal mol−1 barrier. The conformational minima in solution do not correspond to minima in the gaseous state. The calculated solvated-phase dipole moment of CH3Q–3CNQ is in good agreement with the measured moment of C16H33Q–3CNQ.
Posttransplant lymphoproliferative disorder in pancreas transplantation: a single-center experience.

BACKGROUND Posttransplant lymphoproliferative disorder (PTLD) is a rare, serious complication of transplantation. The characteristics and associations of this disease in pancreas recipients have not been extensively studied. METHODS From January 1988 through December 2002, 787 pancreas and 569 kidney-pancreas transplants were performed at our institution. Eighteen pancreas recipients developed polymorphic PTLD or malignant lymphoma. Data on clinical course, organ involvement, molecular characteristics, and association with immunosuppression and recent cytomegalovirus (CMV) infection were compiled from the institutional transplant database. Patient survival was compared to recipients of liver and kidney transplants at the same center by using Kaplan-Meier analysis. RESULTS The 5-year cumulative incidence of PTLD in simultaneous pancreas-kidney, pancreas after kidney, and pancreas transplant alone recipients was 2.5%, 1.2%, and 1.0%, respectively (P = 0.23). A noticeably, but not significantly, higher cumulative incidence was seen in the more recent era since 1995 (2.1% vs. 0.9%, P = 0.15). PTLD in pancreas recipients carried a worse prognosis than in liver or kidney for recipients B-cell, early-onset, and Epstein Barr virus-positive lesions. PTLD was more aggressive in pancreas recipients, with a higher stage at presentation and a trend to more bone marrow involvement. There appeared to be a tendency toward association with recent CMV infection. Since 1995, PTLD recipients have had a lower exposure to antilymphocyte preparations (25 +/- 5 vs. 10 +/- 0.8)(P < 0.05). CONCLUSIONS PTLD in pancreas recipients remains a rare but aggressive disease, and carries a worse prognosis in comparison to other transplant recipients. These heavily immunosuppressed patients, who often face multiple transplants, may be at greater risk; CMV infection may play an antecedent role.
The work of play for parents of schizophrenic children.

During treatment the schizophrenic child begins to emerge from his constricted, self-centered world and to enjoy interaction, play and playfulness. Many of the parents are as constricted and unable to play as their children. The use of a play corner, dress-up clothes and a staff member who can model roles to play helps reduce the “work” of play for parents and child. Their resulting mutual pleasure and increased spontaneity enhances treatment.
Cycle control with oral contraceptives: A review of the literature

Comparing the degree of cycle control provided by various oral contraceptives is problematic. The inherent limitations, small demonstrated differences, and differing methods of data presentation characteristic of these trials support the conclusion that it is almost impossible to compare the bleeding patterns of one preparation with those of another. Chlamydial infection, smoking, and inconsistency of use are factors that have significant effects on rates of spotting and breakthrough bleeding. Clinicians must alert patients to the possibility of intermenstrual bleeding and educate them with regard to the importance of continued, consistent oral contraceptive use to minimize those problems among pill users in their practices.
A signed digit adder using electronically addressable spatial light modulator

In binary digital computers addition is performed employing the carry propagation technique, which essentially limits the computing speed. For multiplication the speed is further reduced because of the number of shift and add operations. To alleviate this problem, a modified signed-bit (MSD) number system has already been proposed. The inher- ent parallel architecture of optical processors makes the best use of the carry-free features of MSD binary numbers. In this paper, we use a very large scale integration SLM and CCD detector to demonstrate truth table lookup for carry-free MSD addition. © 2001 Society of Photo-Optical Instrumen- tation Engineers. (DOI: 10.1117/1.1412615)
Velocity overshoot in ultra-short-gate-length GaAs MESFETs

GaAs MESFETs with ultrashort gates between 0.035 and 0.065 mu m were fabricated to determine trends in their DC transconductance as a function of gate length. It is found that overshoot in the channel causes a considerable increase in the average electron velocity. An approximation based on the gradual channel approximation becomes valid at ultrashort gate lengths due to an increased percentage of the channel that is velocity-saturated. >
Taking another look at Gopher

ABSTRACT Gopher is a client-server program developed at the University of Minnesota in 1991. It enables users to seamlessly access information from computers all over the world. It was the first major improvement to Internet navigation and quickly gained acceptance by large numbers of the computing public. Another client-server program, the World-Wide Web, was introduced in 1992. These two programs are responsible for the phenomenal growth in the rate of Internet traffic over the last few years. This article takes another look at Gopher and discusses its development with respect to the growth of the Internet. Sample screens illustrate various improvements in Gopher navigation tools and techniques.
Worst Case Data Structures for the Priority Queue With Attrition

Abstract We describe three data structures for the priority queue with attrition (or PQA) that perform each PQA operation in O(1) worst-case time. Previous implementations of the PQA required O(1) amortized time per operation.
A composite single electrode potential for the NHE

Abstract The absolute value of the single electrode NHE is estimated from a fundamental view point. Electrocatalysis is commented on, and a comparison with a previous estimate is explored.