cssi/SciSciGPT-SciSciNet huggingface dataset:
On electrical sparks and their use for excitation of spectra

Abstract The spark discharges of the Feussner spark source were studied with a cathode ray oscillograph and a rotating mirror. The spark is a high frequency a.c. arc with a practically current independent, low burning voltage of about 50 V. The current curve is nearly sinusoidal. With a pure spark damping the amplitude decays linearly. In this case the number of high frequency oscillations is independent of the electrical parameters in the spark circuit. Because the burn voltage of the spark is dictated by the intenal mechanism of the arc discharge, one can unhesitatingly place several spark gaps in series, as happens in the Feussner spark source with its interruptor. The division of energy among the individual sparks is regulated. The rotating mirror photographs show the positive columns of the a.c. arc, which burn initially in the air, then later in the metal vapor. The actual breakdown at the beginning of the spark is without meaning for the radiation of the metal. The metal vapor radiates primarily from the vapor clouds, which break out of the electrodes with high speed and after the eruptions are independent of the discharge. The excitation of spark lines is not caused by the high voltages across the spark gap. In order that the individual sparks within spark train are uniform it is necessary that the voltage on the capacitor before the breakdown always be the same. The voltage on the capacitor is independent on the equalization process in the charging circuit. The equalization processes must decay rapidly, hence the charging circuit has to be damped by a resistance and its resonance frequency must lie within a certain range. With uncontrolled (“conventional”) spark sources the voltage on the capacitor depends on the condition of the spark gap. Different discharge forms can develop depending on whether the gap deionizes or the voltage recovers first. Of the uncontrollable sparks, only those with relatively slow voltage recovery (which generate groups of single sparks) appear to be useful for spectroanalysis. The resonace spark source belongs to this class. For investigations of the vaporization of the electrodes and the excitation, uncontrolled spark discharges can only be used with caution. Conclusions for the spectroanalysis are drawn. Because excitation occurs primarily in the vapour clouds, their influence must be carefully watched. Particular attention is given to the cooling on the electrode surfaces. In conclusion we would like to thank the Honorary Dr. Eng . W. Rogowski for allowing us to carry out the cathode ray oscilloscope investigations in his institute, as well as for the interest that he has shown in this work. One of us ( Kaiser ) is indebted with sincere thanks to Dr. G. Hansen , the director of the physical laboratories of the Carl Zeiss Company, for the constant support of this work.
HIV-1 Tat Induces Neuronal Death via Tumor Necrosis Factor-α and Activation of Non-N-methyl-d-aspartate Receptors by a NFκB-Independent Mechanism

Abstract Human immunodeficiency virus type 1 (HIV-1) infection of the central nervous system may result in neuronal apoptosis in vulnerable brain regions, including cerebral cortex and basal ganglia. The mechanisms for neuronal loss are likely to be multifactorial and indirect, since HIV-1 productively infects brain-resident macrophages and microglia but does not cause cytolytic infection of neurons in the central nervous system. HIV-1 infection of macrophages and microglia leads to production and release of diffusible factors that result in neuronal cell death, including the HIV-1 regulatory protein Tat. We demonstrate in this report that recombinant Tat1–86 and Tat peptides containing the basic region induce neuronal apoptosis in approximately 50% of vulnerable neurons in both rat and human neuronal cultures, and this apoptotic cell death is mediated by release of the pro-inflammatory cytokine tumor necrosis factor α, and by activation of glutamate receptors of the non-N-methyl-d-aspartate subtype. Finally, we show that Tat-induced apoptosis of human neuronal cell cultures occurs in the absence of activation of the transcription factor NFκB. These findings further define cellular pathways activated by Tat, that dysregulate production of tumor necrosis factor α, and lead to activation of glutamate receptors and neuronal death during HIV-1 infection of the central nervous system.
Basic study of extrusion of polyethylene and polystyrene foams

A fundamental study of bubble morphology development and apparent rheological properties in foam extrusion is reported. The influence of melt temperature, die length/diameter ratio, and blowing agent level on the morphology are considered. Measurements of the influence of blowing agent on viscosity, extrudate swell, and end-pressure losses are described. The viscosity is reduced, but extrudate swell is increased. End-pressure losses were found to become very large relative to the die wall shear stress at low extrusion rates. These results were interpreted in terms of bubble development. The filling of molds by foaming melts was observed and is described.
Blood-brain barrier integrity in a rat model of emergency preservation and resuscitation

Abstract Emergency Preservation and Resuscitation (EPR) represents a novel approach to treat exsanguination cardiac arrest (CA) victims, using an aortic flush to induce hypothermia during circulatory arrest, followed by delayed resuscitation with cardiopulmonary bypass (CPB). The status of the blood–brain barrier (BBB) integrity after prolonged hypothermic CA is unclear. The objective of this study was to assess BBB permeability in two EPR models in rats, associated with poor outcome. Rats subjected to traumatic brain injury (TBI) and naive rats served as positive and negative controls, respectively. Hypothesis The BBB will be disrupted after TBI, but intact after prolonged hypothermic CA. Methods Four groups were studied: (1) EPR-IC (ice cold)-75min CA at 15°C; (2) EPR-RT (room temperature)-20min CA at 28°C; (3) TBI; (4) sham. Rats in EPR groups were subjected to rapid hemorrhage, followed by CA. Rats in the TBI group had a controlled cortical impact to the left hemisphere. Naives were subjected to the same anesthesia and surgery. 1h after insult, rats were injected with Evans Blue (EB), a marker of BBB permeability for albumin. Rats were sacrificed after 5h and EB absorbance was quantified in brain samples. Results TBI produced an approximately 10-fold increase in EB absorbance in the left (injured) hemisphere vs. left hemisphere for all other groups ( p =0.001). In contrast, EB absorbance in either EPR group did not differ from sham. Conclusion BBB integrity to albumin is not disrupted early after resuscitation from prolonged CA treated with EPR. Neuroprotective adjuncts to hypothermia in this setting should focus on agents that penetrate the BBB. These findings also have implications for deep hypothermic circulatory arrest.
Endogenous respiration of Polyporus sulphureus

Thirty percent of the dry weight of the basidiomycete Polyporus sulphureus is triterpenoid acid. The endogenous respiratory quotient of this organism is 0.8 indicating that the triterpenoid is being used as an endogenous storage material. Monosaccharides did not seem to be utilized as exogenous substrates but Krebs-cycle intermediates stimulated oxygen uptake. Pyruvic acid inhibited oxygen uptake. Studies with /sup 14/C-labeled glucose indicated that 27% of the glucose was metabolized by way of glycolysis. The hexose-monophosphate pathway was the major metabolic path for the utilization of glucose. Despite the fact that P. sulphureus is associated with brown rot, its carbon metabolism suggests that it utilizes substances associated with the degradation of lignin more readily than it does glucose.
A Probabilistic Approach of Designing More Reliable Logic Gates with Asymmetric Input Faults

Logic gates subject to asymmetric input faults may be made more reliable by employing redundant inputs. A mathematical expression for determining the optimum number of redundant inputs based on input reliabilities of the gate is developed. The development follows the theory of combinatorial probability.
An empirical study of industrial security-engineering practices

This paper presents lessons learned and observations noted about the state of security-engineering practices by three information security practitioners with different perspectives - two in industry and one in academia. All authors have more than 20-years experience in this field and two were former members of the US National Computer Security Center during the early days of the Trusted Computer System Evaluation Criteria and the strong promotion of trusted operating systems that accompanied the release of that document. In the last 20 years, it has been argued that security-engineering practices have not kept pace with the escalating threats to information systems. Much has occurred since that time - new security paradigms, failure of evaluated products to emerge into common use, new systemic threats, and an increased awareness of the risk faced by information systems. This paper presents an empirical view of lessons learned in security-engineering, experiences in applying the trade, and observations made about the successes and failures of security practices and technology. This work was sponsored in part by NSF Grant.
Quest for a Reliable Method for Determining Aviation Fuel Thermal Stability: Comparison of Turbulent and Laminar Flow Test Devices

Thermal deposition, based on carbon burn off, was evaluated in two turbulent flow and one laminar flow test devices. The two turbulent flow test devices were the Navy Aviation Fuel Thermal Stability Simulator (NAFTSS), developed by Rolls Royce, UK, for the U.S. Navy, and the High Reynolds Number Thermal Stability (HiReTS) bench rig, developed by Shell Global Solutions, UK (formerly Shell Research and Technology Centre). The laminar flow test device was the Tubular Reactor (TR), a bench rig developed by the Naval Air Systems Command Air-4.4.5 (NAVAIR). Three jet fuels were used in the comparison of the NAFTSS and the TR, and six fuels (five jet and one diesel) in the comparison of the HiReTS and the TR. Good correlations were obtained between the laminar flow and the two turbulent flow test devices. A likely explanation of these results is that for the fuels examined, Reynolds number does not appear to be a critical factor in predicting thermal stability. These results are significant for they support the use of laminar flow in devices such as the specification test method, i.e., the JFTOT, ASTM D3241. Furthermore, on the basis of an overall analysis of the results, we postulate that reactant depletion is likely attributable to a difference in fuel temperature (arising from the difference in flow rate (residence time)/test temperature) and not to a difference in flow velocity (laminar vs turbulent flow). We further postulate that fuel temperature is likely the critical and predominant factor in predicting jet fuel thermal stability, as long as attention is paid to the residence time and thermal gradients of the hot section.
Activation of metabotropic glutamate receptor mediates upregulation of transcription factor mRNA expression in rat striatum induced by acute administration of amphetamine.

Metabotropic glutamate receptors (mGluRs) are densely expressed on the medium spiny projection neurons of rat striatum. Intrastriatal injection of an mGluR agonist increases motor activity and dopamine release in the striatum. This study investigated the roles of mGluRs in the regulation of behavioral activity and transcription factor gene expression in striatal neurons in normal and amphetamine-treated rats. Acute injection of a behaviorally active dose of amphetamine (4.0 mg/kg, i.p.) elevated basal levels of the transcription factor c-fos and zif/268 mRNAs in the dorsal striatum as revealed by quantitative in situ hybridization. Pharmacological blockade of mGluRs with bilateral injections of a non-selective mGluR antagonist, (S)-alpha-methyl-4-carboxyphenylglycine (MCPG), into the dorsal striatum at 10 but not 0.4 nmol significantly attenuated amphetamine-stimulated c-fos mRNA expression in this area. In contrast to c-fos, striatal zif/268 induction stimulated by amphetamine was not altered by pretreatment with MCPG. MCPG by itself did not affect basal levels of either gene expression in the striatum. No significant effects of MCPG were found on spontaneous or amphetamine-stimulated behavioral activities. These data indicate that blockade of total mGluRs in the dorsal striatum has a selective effect on dopamine-stimulated gene expression. Activation of the MCPG-sensitive mGluRs is required for the upregulation of transcription factor c-fos, although not zif/268, mRNA expression in the striatum in response to acute injection of amphetamine.
Entrepreneurial Science: The Rules of the Game

Scholars across a range of academic fields continue to rely on Robert K. Merton’s scientific norms to frame analyses of the privatization of research in the life sciences. I revisit constructivist ...
Lymphocyte migration into the lacrimal gland is random

The murine lacrimal gland demonstrates a high proportion of both IgA-producing cells and IgA-bearing cells, an observation consistent with tissues of the secretory immune system. This selective accumulation of IgA cells in the lacrimal gland was studied by observing the accumulation of various populations of fluorescein isothiocyanate-labeled lymphocytes in the gland. Labeled spleen cells were found to accumulate equally as well as mesenteric lymph node cells. T cells and T-cell-depleted populations of lymphocytes from spleen also showed migration into the gland. Surface staining of labeled cells found in the gland after 24 hr revealed that IgA-, IgG-, and IgM-bearing cells were all present in high proportions. These experiments demonstrate a random migration of lymphocytes into the lacrimal gland and suggest that the accumulation of IgA-bearing cells in the gland is regulated by the nonvascular microenvironment within the gland.
Mechanism of emulsion polymerization of vinylidene chloride. II. Effect of coalescence of polymer particles on kinetics

In seeking an explanation for the unusual kinetics observed in the persulfate-catalyzed emulsion polymerization of vinylidene chloride, the role of particle coalescence has been examined. A theory has been proposed and the predicted results have been compared with experiment. Development of the theory assumes that after excess surfactant (sodium lauryl sulfate) has been removed from the solution by adsorption on the surface of growing polymer particles, coalescence commences as a second-order process with an invariant specific rate constant, and that the rate of polymerization per particle increases linearly with particle volume (it is assumed that more than one growing chain can exist in a particle). The equations derived involve two adjustable parameters: B, a measure of the coalescence rate which is fixed from best fit of one experimental resin, and A, a function of the catalyst concentration. The equations predict a minumum in the conversion rate at some time after the coalescence starts. Data for the third stage of the per-sulfact-catalyzed polymerization of vinylidene cholride can be explained by this theory. It is shown that particle coalescence alone cannot completely explain all of the observations which have been made on this system, however; in particular, the extent of slowdown in Stage II greatly exceeds that predicted by theory.
Lobular carcinoma in situ: observation without surgery as an appropriate therapy.

Background: The finding of lobular carcinoma in situ (LCIS) in the breast has generally prompted treatment with unilateral or bilateral mastectomy. Most experts now feel that LCIS simply identifies a woman who is at high risk to develop future breast cancer and requires only close clinical and mammographic follow-up. This approach has been recommended at our institution for >15 years. This study defines the natural history of a population of women with LCIS who were treated by observation alone.
Molecular dynamics simulations of proteins in lipid bilayers

With recent advances in X-ray crystallography of membrane proteins promising many new high-resolution structures, molecular dynamics simulations will become increasingly valuable for understanding membrane protein function, as they can reveal the dynamic behavior concealed in the static structures. Dramatic increases in computational power, in synergy with more efficient computational methodologies, now allow us to carry out molecular dynamics simulations of any structurally known membrane protein in its native environment, covering timescales of up to 0.1 micros. At the frontiers of membrane protein simulations are ion channels, aquaporins, passive and active transporters, and bioenergetic proteins.
Probability: Inductive versus deductive

THE PURPOSE of this paper is to demonstrate, by means of elementary logical principles, that there is no such thing as a valid "deductive probability" argument. The view that there is was probably originated by Jacques Bernoulli, and was developed by numerous adherents of the classical theory of probability. More recently, it has received the powerful and influential support of C. S. Peirce (A Theory of Probable Inference), W. S. Jevons (Principles of Science), and, among contemporaries, D. C. Williams (The Ground of Induction), C. J. Ducasse (Some Observations concerning the Nature of Probability), C. I. Lewis (An Analysis of Knowledge and Valuation, and Professor Chisholm and Empiricism), R. M. Chisholma (The Problem of Empiricism), and others too numerous to mention, who accept though they do not specifically advocate the theory of "deductive probability arguments."
Cannabis Effects on Driving Skills

BACKGROUND: Cannabis is the most prevalent illicit drug identified in impaired drivers. The effects of cannabis on driving continue to be debated, making prosecution and legislation difficult. Historically, delays in sample collection, evaluating the inactive Δ9-tetrahydrocannabinol (THC) metabolite 11-nor-9-carboxy-THC, and polydrug use have complicated epidemiologic evaluations of driver impairment after cannabis use. CONTENT: We review and evaluate the current literature on cannabis' effects on driving, highlighting the epidemiologic and experimental data. Epidemiologic data show that the risk of involvement in a motor vehicle accident (MVA) increases approximately 2-fold after cannabis smoking. The adjusted risk of driver culpability also increases substantially, particularly with increased blood THC concentrations. Studies that have used urine as the biological matrix have not shown an association between cannabis and crash risk. Experimental data show that drivers attempt to compensate by driving more slowly after smoking cannabis, but control deteriorates with increasing task complexity. Cannabis smoking increases lane weaving and impaired cognitive function. Critical-tracking tests, reaction times, divided-attention tasks, and lane-position variability all show cannabis-induced impairment. Despite purported tolerance in frequent smokers, complex tasks still show impairment. Combining cannabis with alcohol enhances impairment, especially lane weaving. SUMMARY: Differences in study designs frequently account for inconsistencies in results between studies. Participant-selection bias and confounding factors attenuate ostensible cannabis effects, but the association with MVA often retains significance. Evidence suggests recent smoking and/or blood THC concentrations 2–5 ng/mL are associated with substantial driving impairment, particularly in occasional smokers. Future cannabis-and-driving research should emphasize challenging tasks, such as divided attention, and include occasional and chronic daily cannabis smokers.
Design of stochastic Viterbi decoders for convolutional codes

The Viterbi algorithm is widely used to decode convolutional codes. We present an unconventional approach to Viterbi decoder design based on stochastic computing (SC) which represents data by random bit-streams that can be interpreted as probabilities. Stochastic circuits allow many decoding functions to be implemented by simple hardware; e.g., multi-bit multiplication can be realized by an AND gate. SC is also highly error-tolerant since a soft error (bit-flip) has little impact on a SC number's value. It also allows decoding precision to be traded for decoding speed. We design two SC-based Viterbi decoders and also a hybrid binary-SC design; the latter uses SC for arithmetic calculations, but not for storing numbers. The proposed designs are compared with a binary (non-SC) decoder using a standard (7, 1/2) convolutional code. The SC designs are found to be more tolerant of soft errors in the decoder than the binary design, and more capable of supporting some useful trade-offs among area cost, data rate, precision, and bit-error rate.
Modified Elastofiber Element for Steel Slender Column and Brace Modeling

An efficient beam element, the modified elastofiber (MEF) element, has been developed to capture the overall features of the elastic and inelastic responses of slender columns and braces under axial cyclic loading without unduly heavy discretization. It consists of three fiber segments, two at the member ends and one at midspan, with two elastic segments sandwiched in between. The segments are demarcated by two exterior nodes and four interior nodes. The fiber segments are divided into 20 fibers in the cross section that run the length of the segment. The fibers exhibit nonlinear axial stress-strain behavior akin to that observed in a standard tension test of a rod in the laboratory, with a linear elastic portion, a yield plateau, and a strain-hardening portion consisting of a segment of an ellipse. All the control points on the stress-strain law are user defined. The elastic buckling of a member is tracked by updating both exterior and interior nodal coordinates at each iteration of a time step and checking force equilibrium in the updated configuration. Inelastic postbuckling response is captured by fiber yielding, fracturing, and/or rupturing in the nonlinear segments. The key features of the element include the ability to model each member using a single element, easy incorporation of geometric imperfection, partial fixity support conditions, member susceptibility to fracture defined in a probabilistic manner, and fiber rupture leading to complete severing of the member. The element is calibrated to accurately predict the Euler critical buckling load of box and I sections with a wide range of slenderness ratios (L/r=40, 80, 120, 160, and 200) and support conditions (pinned-pinned, pinned-fixed, and fixed-fixed). Elastic postbuckling of the Koiter-Roorda L frame (tubes and I sections) with various member slenderness ratios (L/r=40, 80, 120, 160, and 200) is simulated and shown to compare well against second-order analytical approximations to the solution even when using a single-MEF element to model each leg of the frame. The inelastic behavior of struts under cyclic loading observed in the experiments of Black et al., Fell et al., and Tremblay et al. is accurately captured by single-MEF-element models. A FRAME3D model (using MEF elements for braces) of a full-scale six-story braced frame structure that was pseudodynamically tested at the Building Research Institute of Japan subjected to the 1978 Miyagi-Ken-Oki earthquake record is analyzed and shown to closely mimic the experimentally observed behavior.
ASSESSING IMPACT OF INSTITUTIONAL STUDIES

A three-dimensional model which relates time, action, and audience components has been developed to assess impact of institutional studies. Elements of the models are: short, intermediate, and long-range time components; acceptance, nonresponse, and rejection actions; and primary, secondary, and tertiary audiences. A variety of criterion measures and instruments have been identified to assist in the model implementation. A research impact gram (RIG) is offered as a comprehensive graphic analysis mechanism for the model. Data analysis limitations are noted for each of the model components. Suggestions for further research are offered.
Tourism's Role and Response to Environmental Issues and Potential Future Effects

This paper is an effort to consider various alternative implications that may result because of tourism's increasing concern and involvement in environmental issues. Professional meetings and literature are full of the new buzz words in the industry “eco‐tourism,” and “sustainable development.” Many meetings and conferences, such as the African Tourism Association and the Pacific Asian Travel Association, in this early period of the nineties are using the environment as the major issue concerning the future of tourism.
The relationship between maternal and fetal plasma protein binding of methadone in the ewe during the third trimester

Abstract The binding of methadone to maternal and fetal plasma proteins was determined throughout the third trimester in the pregnant ewe. Blood was sampled from chronic indwelling catheters placed in the maternal aorta and fetal aorta. Methadone binding was determined by use of equilibrium dialysis with ( 3 H)-methadone. Maternal binding ranged from 50.4 to 89.5%, with a mean of 76.2 ±1.3 (SE)%. Fetal binding was initially significantly lower than maternal binding, but increased rapidly in the last two weeks before parturition. Prior to 130 days gestation, the ratio of fetal binding to maternal binding was 0.40 ± 0.03. This binding ratio increased to 0.82 ± 0.08 in the last few days of pregnancy. Preliminary results suggested that maternal binding was higher in the early post-partum period. These results demonstrate that the relationship between maternal and fetal plasma binding of methadone changes rapidly towards the end of pregnancy, and fetal binding approaches maternal binding at parturition.
Deconvolution program for non-computer scientists

Abstract A simple deconvolution program has been written which is designed for those with little computer science experience. The program resolves infrared spectra into their Gaussian components and has been found to be particularly useful in studies of systems where hydrogen-bondings is important. By resolving the overlapping bands which result from hydrogen-bonded and non-hydrogen-bonded OH groups, one can determine the change in the percent of hydrogen-bonding in the system. Bands due to different types of hydrogen-bonding such as inter and intra-molecular hydrogen-bonding may also be resolved. The mathematics involved is much simpler than that in most deconvolution programs, and this program does not diverge even if initial guesses for band parameters are not extremely accurate. The program plots the experimental and calculated spectra every fifth iteration, and on convergence, plots the resolved curves, lists the X and Y values for each curve, and calculates the area under each curve and the per cent of the total curve.
“Hot Hand” on Strike: Bowling Data Indicates Correlation to Recent Past Results, Not Causality

Recently, the “hot hand” phenomenon regained interest due to the availability and accessibility of large scale data sets from the world of sports. In support of common wisdom and in contrast to the original conclusions of the seminal paper about this phenomenon by Gilovich, Vallone and Tversky in 1985, solid evidences were supplied in favor of the existence of this phenomenon in different kinds of data. This came after almost three decades of ongoing debates whether the “hot hand” phenomenon in sport is real or just a mis-perception of human subjects of completely random patterns present in reality. However, although this phenomenon was shown to exist in different sports data including basketball free throws and bowling strike rates, a somehow deeper question remained unanswered: are these non random patterns results of causal, short term, feedback mechanisms or simply time fluctuations of athletes performance. In this paper, we analyze large amounts of data from the Professional Bowling Association(PBA). We studied the results of the top 100 players in terms of the number of available records (summed into more than 450,000 frames). By using permutation approach and dividing the analysis into different aggregation levels we were able to supply evidence for the existence of the “hot hand” phenomenon in the data, in agreement with previous studies. Moreover, by using this approach, we were able to demonstrate that there are, indeed, significant fluctuations from game to game for the same player but there is no clustering of successes (strikes) and failures (non strikes) within each game. Thus we were lead to the conclusion that bowling results show correlation to recent past results but they are not influenced by them in a causal manner.
Evaluation of the e‐rater® Scoring Engine for the TOEFL® Independent and Integrated Prompts

Scoring models for the e-rater® system were built and evaluated for the TOEFL® exam's independent and integrated writing prompts. Prompt-specific and generic scoring models were built, and evaluation statistics, such as weighted kappas, Pearson correlations, standardized differences in mean scores, and correlations with external measures, were examined to evaluate the e-rater model performance against human scores. Performance was also evaluated across different demographic subgroups. Additional analyses were performed to establish appropriate agreement thresholds between human and e-rater scores for unusual essays and the impact of using e-rater on operational scores. Generic e-rater scoring models were recommended for operational use for both independent and integrated writing tasks. The two automated scoring models were recommended for operational use to produce contributory scores within a discrepancy threshold of 1.5 and 1.0 with a human score for independent and integrated prompts respectively.
Systematic design and analysis of laser-guide-star adaptive-optics systems for large telescopes

We discuss the design of laser-guided adaptive-optics systems for the large, 8–10-m-class telescopes. Through proper choice of system components and optimized system design, the laser power that is needed at the astronomical site can be kept to a minimum.
Points of finite order on Elliptic curves

(1986). Points of Finite Order on Elliptic Curves. The American Mathematical Monthly: Vol. 93, No. 10, pp. 793-795.
Fine structure of neuronal and glial processes in neuropathology

The cells of the nervous system are characterized by their well-formed cell processes and by cell-to-cell relationships that they form. The neuron reveals essentially cylindrical processes, which form synaptic junctions. On the other hand, the peripheral parts of the glial cells are mainly sheet-like in nature. Thus, the oligodendroglial cell elaborates many sheet-like processes, each of which forms a segment of the myelin sheath. Unique cell junction, transverse bands are present at the interface of oligodendroglial processes and the axon. Finally, the astrocytes also form elaborate sheet-like processes, which separate most of the CNS from the mesodermal tissue as well as surrounding certain neuronal surfaces, including synapses. Punctate adhesions, gap junctions and other adhesive devices are present between astrocytic processes. Defects or anomalies in the neuronal and glial cell processes characterize numerous pathological conditions.
A free gift card alternative to price discounts in the newsvendor problem

Abstract In this paper, we develop a newsvendor model in which the retailer gives “free” gift cards to consumers who purchase a regularly priced product at the end of the selling season instead of discounting the product. The model is developed for a market with patient consumers. We derive the sufficient optimality condition for the retailer's stocking level in the first period and the optimal gift card value in the second period. We also investigate the conditions under which giving gift cards results in higher expected profits than discounting the product. We find that five factors determine the effectiveness of gift cards. The first three factors are consumers' valuation per $1 of gift card, gift card redemption rates, and the average gross margin of the retailer. The last two factors are the degree to which consumers use gift cards to pay for products which they would have purchased from the retailer in the future with cash, and the additional spending above the gift card value consumers make when they redeem the card. The last two factors have a strong interaction. We also find that gift cards can be profitable when patient consumers consistently value each $1 by their redemption probability, even with 100% redemption. Numerical analysis shows that in the presence of patient consumers, increases in the redemption rate may lead to an increase in the expected profit. Similar counter-intuitive behavior of the expected profit occurs with changes in other problem parameters. The analysis also shows that gift cards' profit advantage over discounting increases with the variability of demand. The analysis also indicates that gift cards are most effective for low to medium priced products sold by high margin retailers.
John Dewey's aesthetics of communication

Discussion of John Dewey within the discipline of communication is often restricted to his “ritual view” of communication or his youthful hope in the democratic potential of mass communication technologies. However, both of these approaches neglect the importance of his aesthetic theory for understanding both his philosophy of communication and his overall social thought. This essay takes a developmental perspective on Dewey's philosophy and traces how his concepts of experience and communication evolved over three decades and finally came to be unified in his concept of aesthetic experience. I argue that a developmental perspective on Dewey's aesthetic philosophy contributes a broader and more flexible understanding of communication that leads to the view that communication, at its best, is a form of art in which poiesis and praxis are united within a single, consummatery experience.
Combined treatment for band keratopathy.

To the editor: I read with interest the two case reports by Kwon et al. on "New Treatment for Band Keratopathy: Superficial lamellar Keratectomy, EDTA Chelation and Amniotic Membrane Transplantation" (1). In their article, they describe two cases of calcific band keratopathy (CBK) that were treated with a combination of EDTA chelation, superficial keratectomy and amniotic membrane transplantation. The authors concluded that this combined treatment was a safe and effective method for the removal of deep situated calcium plaques, thus allowing the recovery of a stable ocular surface. With my colleagues, I have recently published a study that looked at the effectiveness of EDTA chelation in CBK (2). In the 65 eyes of 54 patients that we have followed after EDTA chelation, we found significant visual improvement of two or more lines in up to half of the eyes that were treated, as well as symptomatic relief in 98% of the patients. Some of our cases with deep and dense CBK required from 5 to 45 min of EDTA application for complete resolution. This might explain the unsatisfactory results with EDTA chelation alone in the two cases reported by Kwon et al. who applied the EDTA for just 2.5 min in both cases. The authors reported no recurrence of symptoms in their patients during their mean follow-up period of 13.5 months. In our study, we found that the mean time for recurrence was 17.7 yr. The absence of any recurrences in the cases described by Kwon et al. could be attributed to their shorter follow-up period rather than to the success of the combined treatment modality they describe. In short, I believe that EDTA chelation, when used properly, is an effective treatment for CBK. It is simple, inexpensive and avoids the additional risks of an invasive procedure such as superficial keratectomy, or the added costs of amniotic membrane transplantation, especially in eyes with poor visual potential. We recommend it as a first line treatment for calcific band keratopathy.
Electron beam matching and its influence on the performance of high-gain free-electron lasers

Abstract We consider the influence of electron beam on the performance of high-gain FELs. We test this hypothesis for a SASE configuration using a 3-D multimode simulation. The gain length predicted for a matched beam agrees well with analytic theory, and the simulation indicates that while the gain length is optimized for a matched beam the saturated power may not be optimized. In previous work we have considered a flat-top beam model while we also consider a Gaussian beam model, and conclude the two are in substantial agreement.
Coherent transients excited by subpicosecond pulses of terahertz radiation

Using a newly developed optoelectronic source of well-collimated beams of subpicosecond pulses of terahertz radiation to excite a N2O vapor cell, we have observed the subsequent emission from the vapor of a coherent pulse train extending as long as 1 ns. The individual subpicosecond terahertz pulses of the train are separated by 39.8 ps, corresponding to the frequency separation between adjacent rotational lines of the excited manifold of more than 50 lines. From these observations the coherent relaxation time T2 is obtained as a function of vapor pressure, even for the case of overlapping lines. In addition, from the pulse repetition rate in the train the frequency separation between the rotational lines is determined. Finally, from the changing individual pulse shapes in the train the anharmonicity factor for the N2O molecule is evaluated.
Polypohosphazene Fluoroelastomer for Denture Liners and Facial Prosthetics

Firestone PNF®-200 and later, Ethyl Eypel®-F were compounded with di- and tri-functional acrylates, BaSO4, peroxide activator, and pigment to make a hot water-curing polyphosphazene liner for removable dentures. Advantages include permanent softness (durometer A = 35), energy absorbance, fungus resistance, and bonding to PMMA dentures. Uses may also include facial prosthetics which replace parts of the face lost due to cancer, trauma, or birth defects.
Gene expression profiling in spleens of deoxynivalenol-exposed mice: immediate early genes as primary targets.

Exposure to the trichothecene mycotoxin deoxynivalenol (DON) alters immune functions in vitro and in vivo. To gain further insight into DON's immunotoxic effects, microarrays were used to determine how acute exposure to this mycotoxin modulates gene expression profiles in murine spleen. B6C3F1 mice were treated orally with 25mg/kg body weight DON, and 2h later spleens were collected for macroarray analysis. Following normalization using a local linear regression model, expression of 116 out of 1176 genes was significantly altered compared to average expression levels in all treatment groups. When genes were arranged into an ontology tree to facilitate comparison of expression profiles between treatment groups, DON was found primarily to modulate genes associated with immunity, inflammation, and chemotaxis. Real-time polymerase chain reaction was used to confirm modulation for selected genes. DON was found to induce the cytokines interleukin (IL)-1α, IL-1β, IL-6 and IL-11. In analogous fashion, DON upregul...
Adapting Clicker Technology to Diversity Courses: New Research Insights

Diversity courses present many challenges to instructors, but foremost among these is student resentment of the material and theoretical approaches. Clickers exhibit several features making them potentially useful in diversity courses. Specifically, clickers provide opportunities for students to anonymously register their opinions on contentious social issues (“opinion polling”) as well as their difficulty with course material (“content polling”). While existing literature documents the value of clickers for content polling, there is little research on opinion polling and none on their use in diversity courses. This comparative case study is an exploratory investigation of the value of clicker use in two political science diversity courses. Student and instructor perspectives were gathered using several approaches, including an open-ended feedback form, a questionnaire, TA-instructor interviews, and a database of clicker polls. Findings support the value to student learning of both opinion and content pol...
Exercise ameliorates chronic kidney disease–induced defects in muscle protein metabolism and progenitor cell function

Chronic kidney disease (CKD) impairs muscle protein metabolism leading to muscle atrophy, and exercise can counteract this muscle wasting. Here we evaluated how resistance exercise (muscle overload) and endurance training (treadmill running) affect CKD-induced abnormalities in muscle protein metabolism and progenitor cell function using mouse plantaris muscle. Both exercise models blunted the increase in disease-induced muscle proteolysis and improved phosphorylation of Akt and the forkhead transcription factor FoxO1. Muscle overloading, but not treadmill running, corrected protein synthesis and levels of mediators of protein synthesis such as phosphorylated mTOR and p70S6K in the muscles of mice with CKD. In these mice, muscle overload, but not treadmill, running, increased muscle progenitor cell number and activity as measured by the amounts of MyoD, myogenin, and eMyHC mRNAs. Muscle overload not only increased plantaris weight and reduced muscle proteolysis but also corrected intracellular signals regulating protein and progenitor cell function in mice with CKD. Treadmill running corrects muscle proteolysis but not protein synthesis or progenitor cell function. Our results provide a basis for evaluating different types of exercise on muscle atrophy in patients with chronic kidney disease.
High-frequency gas-discharge breakdown in helium

Breakdown electric fields in low pressure helium at high frequencies have been theoretically predicted and experimentally verified. The energy distribution of electrons is derived from the Boltzmann transport equation, taking into account all significant removal processes. The distribution function is expanded in spherical harmonics and the resulting second order linear differential equation is solved in terms of the confluent hypergeometric function. This distribution function combined with kinetic theory formulas permits calculation of the ionization rate and the electron diffusion coefficient. From these the high frequency ionization coefficient is determined. Through the diffusion equation this ionization coefficient is related to breakdown electric fields. Thus breakdown electric fields are predicted theoretically without using any gas discharge data other than experimental values of the excitation potential and collision cross section of helium. Breakdown electric fields are measured for helium in microwave cavities of various sizes with a large range of pressure. The theoretical electric fields, involving no adjustable parameters, are checked within the maximum experimental error of 6 percent.
Overcoming Communication Latency Barriers in Massively Parallel Scientific Computation

Anton, a massively parallel special-purpose machine that accelerates molecular dynamics simulations by orders of magnitude, uses a combination of specialized hardware mechanisms and restructured software algorithms to reduce and hide communication latency. Anton delivers end-to-end internode latency significantly lower than any other large-scale parallel machine, and its critical-path communication time for molecular dynamics simulations is less than 3 percent that of the next-fastest platform.
ON THE NATURE OF THE SPECTRUM OF THE TIME CORRELATION FUNCTION MATRIX FOR STOCHASTIC PROCESSES.

If a stochastic process has a finite Poincare recursion time,' the time correlation function matrix a(t) a(t + r) is an almost periodic function of r. Here, a is a generalized vector whose components represent the departure of the observable macroscopic properties of the system from their equilibrium or steady-state values. The almost periodic nature of a(t)au(t + r) is commonly taken to imply that the ensemble average of the time correlation function matrix R(t,r) a(t)W (t + r) is also almost periodic and thus has a discrete spectrum.' This leads to statements implying that in order to obtain irreversible behavior and an absolutely integrable spectrum, the recurrence time must be made infinite by taking the limit of an infinitely large system. In this paper it is found that R(t,r) vanishes irreversibly as T * oo, for all but a small class of very special (unphysical) stochastic models. The existence of finite recursion times and the exact use of deterministic mechanics do not change this property. The argument makes explicit an opinion of Uhlenbeck,3 and hopefully puts to rest the emphasis on the importance of Poincare cycles in statistical mechanics. For this study it is convenient to define certain probability distribution functions: p(a,t)da is the probability that the system be found at time t with its macroscopic state between a and a + dot; p(a,tla', t + r)dada' is the joint probability that the system be found at time t in a to a + du and at time t + T in a' to a' + da'; P(a,tl a',t + T)da' is the probability the system will be found between o' and a' + da' at time t + r under the condition that it be in a at time t. Then,
Grass pollen immunotherapy induces Foxp3-expressing CD4(+)CD25(+) cells in the nasal mucosa

Background Regulatory T (Treg) cells play an important role in controlling allergic inflammation. The transcription factor Foxp3 regulates the development and function of natural and adaptive CD4 + CD25 + Treg cells. Objectives We sought to examine the effect of grass pollen injection immunotherapy on the numbers of Foxp3 + CD4 + and Foxp3 + CD25 + T cells in and out of season and their expression of IL-10 in the nasal mucosa of patients with hay fever. Methods Nasal biopsy specimens were obtained from untreated patients with hay fever, participants with grass pollen allergy who had received 2 years of immunotherapy, and healthy control subjects. Dual-immunofluorescence microscopy was used to enumerate and colocalize Foxp3 expression to CD4 + and CD25 + T cells in the nasal mucosa. Triple staining was performed to colocalize Foxp3 + cells to CD3 + CD25 + and CD3 + IL-10–expressing cells. Results At peak season, numbers of Foxp3 + CD25 + ( P = .02) and Foxp3 + CD4 + ( P = .03) cells were significantly increased in the nasal mucosa of immunotherapy-treated patients compared with numbers before treatment. Foxp3 + CD25 + ( P = .03) and Foxp3 + CD4 + ( P = .04) cells were also greater in immunotherapy-treated patients out of season compared with those in untreated patients with hay fever. Within the immunotherapy-treated group, 20% of CD3 + CD25 + cells expressed Foxp3, and 18% of Foxp3 + CD3 + cells were IL-10 positive. Conclusion The presence of local Foxp3 + CD25 + CD3 + cells in the nasal mucosa, their increased numbers after immunotherapy, and their association with clinical efficacy and suppression of seasonal allergic inflammation support a putative role for Treg cells in the induction of allergen-specific tolerance in human subjects.
Low temperature nmr study of two-dimensional molecular motion

Abstract The magnetic properties of surface layers of methane physisorbed on porous silicon have been studied in detail for several submonolayer coverages. At 0.6 monolayer, the spin-lattice relaxation time T1 versus temperature showed two minima and two discontinuities between 1.3K and 73K, while at 0.3 monolayer the Tl behavior was much more complex. At 0.8 monolayer, T1 increased dramatically by several orders of magnitude. The restriction of the pore size is believed to be responsible for this unusual T1 behavior. The relaxation times for the 0.3 and 0.8 monolayers were non-exponential, due to the presence of two or three groups of spins whose local environments were different from each other.