cssi/SciSciGPT-SciSciNet huggingface dataset:
Classical Limit for a System of Non-Linear Random Schrödinger Equations

This work is concerned with the semi-classical analysis of mixed state solutions to a Schrodinger–Position equation perturbed by a random potential with weak amplitude and fast oscillations in time and space. We show that the Wigner transform of the density matrix converges weakly and in probability to solutions of a Vlasov–Poisson–Boltzmann equation with a linear collision kernel.Aconsequence of this result is that a smooth non-linearity such as the Poisson potential (repulsive or attractive) does not change the statistical stability property of the Wigner transform observed in linear problems.We obtain, in addition, that the local density and current are self-averaging, which is of importance for some imaging problems in random media. The proof brings together the martingale method for stochastic equations with compactness techniques for non-linear PDEs in a semi-classical regime. It relies partly on the derivation of an energy estimate that is straightforward in a deterministic setting but requires the use of a martingale formulation and well-chosen perturbed test functions in the random context.
Multidirectional Instability in the Female Athlete

Multidirectional instability of the shoulder (MDI) is the least common form of shoulder instability. It is characterized by a global laxity of the joint capsule that leads to symptomatic inferior instability in addition to anterior or posterior instability or both. Patients with MDI are atypical in that they often have no history of trauma and may present with only vague complaints. They tend to have a loose, patulous inferior capsule in addition to altered glenohumeral and scapulothoracic mechanics, which contribute to instability. Female athletes may be particularly susceptible to MDI because of an increased predisposition to joint hyperlaxity. In addition, female athletes tend to favor sports that both reward and demand flexibility such as gymnastics, ice skating, diving, yoga, and cheerleading, which may cause MDI to become more symptomatic. The goals of treatment include pain relief, functional rehabilitation, and return to sport. Most patients respond well to a rehabilitation protocol involving strengthening of the rotator cuff, scapular stabilization exercises, and proprioceptive training exercises. For patients who fail to respond to conservative treatment, open or arthroscopic capsular shift may be performed, with the technique tailored to the patient’s individual pathology. Postoperative rehabilitation aims to restore range of motion, flexibility, and strength while protecting the integrity of the surgical repair. With close adherence to a well-designed rehabilitation protocol, patients may achieve predictably good outcomes, with a low recurrence rate of instability and a high rate of return to sports. Patients should be advised that surgery may decrease their range of motion, and that they may not be able to return to the same level of athletic competition.
Non-invasive impedance analysis: a new non-invasive test for graft surveillance.

Abstract Detection of failing grafts with early reoperation is clearly associated with better long-term patency than intervention after graft failure. Duplex ultrasonography is more accurate than ankle:brachial index for graft surveillance, but is expensive, time consuming and technically demanding. Non-invasive estimation of graft impedance is now possible. The present study was undertaken to evaluate the utility of non-invasive impedance in detecting the failing vein graft. Sixty-nine grafts in 51 patients were followed over a period of 12 months (April 1992–March 1993). High risk infrainguinal arterial vein bypass patients were entered into a graft surveillance program. Ankle:brachial index, non-invasive impedance and duplex ultrasonography were performed upon discharge, 1 month after surgery and then at 3-monthly intervals. Non-invasive impedance was measured using a mean Doppler flow signal obtained from both upper and lower ends of the graft paired with the mean pulse volume recording obtained from the distal arterial bed. The mean pulse volume recording and flow signals were digitized by discrete Fourier transform and an impedance index generated. An impedance index ⩾ 0.5 was considered abnormal. Impedance results were compared with ankle:brachial index, duplex ultrasonography and angiography when appropriate, and detected 28 failing and five failed grafts. Non-invasive impedance achieved a sensitivity of 91 % and a specificity of 94%. Similarly, duplex ultrasonography was 91% sensitive and 97% specific, while ankle:brachial index was 58% sensitive and 94% specific. Non-invasive impedance is a simple, inexpensive and effective test which detects the failing graft and is an appropriate first-line alternative to duplex ultrasonography for postoperative graft surveillance.
Agriculture and the Environment: The Demand for Conflict Resolution Mechanisms

ABSTRACT Mutually acceptable solutions that are obtained from resolving conflicts that surround agriculture and the environment have important implications for natural resource use and ecological balance. Thus, the ability to understand the determinants of conflict resolution presents an important opportunity for researchers and policy makers to assess the likely or possible outcomes in conflict situations. This paper estimates an empirical model that examines the relationship between the demand for conflict resolution mechanisms and several socioeconomic variables. The analysis suggests that income and the sharing of information are influential in the demand for conflict resolution mechanisms. The findings also show that farmers are willing to be equal partners with environmentalists in attempts to resolve conflicts peacefully.
Epidemiologic Musing on Statin Drugs in the Prevention of Advanced Prostate Cancer

In this issue of Cancer Epidemiology, Biomarkers, and Prevention , the journal has published three large prospective studies: Cancer Prevention Study II Nutrition Cohort ([1][1]), California Men's Health Cohort Study (CMHCS; ref. [2][2]), and a case-control study nested in the Finnish population ([3
Neutral Composition of the Upper Atmosphere of Mars as Determined from the Mariner UV Spectrometer Experiments

Atomic oxygen and hydrogen identification in Mars upper atmospheric emission spectra by Mariner UV spectrometer, inferring carbon monoxide presence by self absorption
Changes in the Fluoride-induced Modulation of Maturation Stage Ameloblasts of Rats

The maturation stage of enamel development is characterized by a cyclic modulation of the ameloblasts between bands of smooth-ended cells and longer bands of ruffle-ended cells. There are cyclic patterns of calcein staining of and 45Ca uptake in the enamel associated with this cellular modulation. Rats were given 0, 75, 100, or 150 ppm fluoride in their drinking water. Fluoride disrupted the cyclic patterns of the maturation stage, resulting in fewer bands of smooth-ended ameloblasts, fewer calcein-stained stripes, and fewer cycles of 45Ca uptake. When animals were given water containing 0 ppm fluoride following ingestion of water containing 100 ppm fluoride, the pattern of calcein staining returned to that of the control enamel. The disruption of the cyclic patterns in the maturation stage and the increased protein content of maturation enamel seem to be among the early events in the development of fluorosis.
Oxaloacetate inhibition of aconitate hydratase

Abstract An oxaloacetate-Fe 2+ complex has been found to be a potent competitive inhibitor of aconitate hydratase. The requirement for both oxaloacetate and Fe 2+ in this inhibition appears to be absolute.
Formation of Protein Charge Ladders by Acylation of Amino Groups on Proteins

The values of charge and electrophoretic mobility of a protein are changed upon acylation of its α- and Lys e-NH3+ groups. Partial acylation of the amino groups of a protein results in a set of derivatives that is often resolved by capillary electrophoresis into a set of distinct peaksthe “rungs” of a protein charge ladderthat differ incrementally in the number of residues modified. Proteins that have values of MW 50 kD form broad unresolved peaks. Resolved charge ladders of proteins that have values of MW > 50 kD may be formed using acylating agents that introduce several charges upon acylation of each of their Lys e-NH3+ groups. As an example, l-lactate dehydrogenase (MW = 147 kD) does not form a resolved charge ladder when modified with acetic anhydride. When it is acylated with either 1,2,4-benzenetricarboxylic anhydride, 3, or 1,2,4,5-benzenetetracarboxylic dianhydride, 4,...
Oral Abscess Caused by Campylobacter rectus: Case Report and Literature Review

Campylobacter rectus was isolated under routine anaerobic conditions (no additional hydrogen gas in the atmosphere) from an oral, nonperiodontal abscess from a patient with gastroesophageal adenocarcinoma. We report the first case of a palate abscess caused by C. rectus and review the literature and atmospheric requirements of this organism.
Analysis of Time Variations in Natural Background Gamma Radiation Flux Density

Data of variations in natural background γ-radiation flux density obtained from observations near the ground surface made for a period of almost 1 year are given together with data on simultaneous measurements on changes in various environmental influencing factors, such as the degree of soil dryness, atmospheric radon daughter concentration and rainfall rate. Statistical and time series analyses of these data have provided much information on the relationships between the flux density and influencing factors and periodical characteristics of those variations in the natural environment. It is concluded from the results of the analyses that the atmospheric randon daughters and rainfall play an important role in short- and middle-term variations in the background radiation flux, while the change of soil dryness contributes to long-term variations.
Surface studies of 2,4-pentanedione on γ-Al2O3/NiAl (1 0 0) and NiAl (1 0 0)

Abstract The chemical compound 2,4-pentanedione (Hacac) has been shown to etch the oxidized metal surfaces metals such as copper and nickel, but not their unoxidized surfaces. Here it is shown that on the γ-Al 2 O 3 /NiAl (1 0 0) surface (oxidized NiAl (1 0 0)) etching of aluminum occurs at 170 K and 750 K. Reflection–absorption infrared spectroscopy (RAIRS) is used to show that Hacac binds to both the clean, metallic and oxidized surfaces, but decomposition and combustion products dominate on the metallic surface and no etching occurs. The binding process that involves a deprotonation reaction of the enol species was identified by redshift in the carbonyl peaks and the appearance of an Al–H peak observed in the IR spectrum. The implication of these results is that there is both an unusual low temperature and high temperature etching of the alumina by bound acac.
The weaning of the green: Environmentalism comes of age in the 1990s

The extremes must come closer to each other for the problems caused by environmental pollution to be solved equitably. E nvironmental issues are certain to assume enhanced prominence throughout the 1990s and into the twenty-first century. Environmentalism will provide new business opportunities, such as marketing biodegradable plastics, dolphin-safe canned tuna, and even wristwatches containing small gardens of grass. The most significant economic effect of the environmental movement, however, will continue to be business costs of complying with government regulations and corporate liability for damages from pollution. As environmental control costs grow, the pattern of regulation and liability will continue to evolve in new directions. Environmental regulation and liability already carry enormous economic effect. The Environmental Protection Agency estimated that private industry spent $64 billion in 1988 to prevent or clean up pollution, and federal, state, and local governments spent an additional $31 billion. The expenses of pollution control have steadily increased since the early 1970s. The soon-to-bepassed reauthorization of the Clean Air Act will probably add another $10-$20 billion in annual economic cost. Countless additional dollars are paid out in common law and statutory liability awards and settlements for environmental damages. Economic studies have attributed a significant portion of the nation's productivity slowdown to environmental expenditures. Environmental protection regulation and liability have become an integral part of business planning for most industries, including many promising hightech industries. To state the considerable costs of pollution control is not to dejustify them, however. Environmental contamination annually causes billions of dollars of direct economic loss, without even considering costs to public health and quality of life. Eliminating pollution control expenditures is not an economically efficient action and is politically unacceptable. As costs rise, pressure from international competition makes it increasingly essential not to waste expenditures on relatively valueless endeavors, but to obtain the greatest possible environmental protection bang for the buck. Traditional environmental regulation, unfortunately, has been neither particularly efficient nor effective. Environmental concerns have been marked by considerable antagonism between the environmental and industrial communities. In a political attempt to appear "greener than thou," environmental activists have demanded the most extreme levels of environmental protection and refused to consider the costs of such protection. Industrial representatives have too often fought even efficient environmental protection measures and employed spurious science on behalf of their position. The product of this hostile battle is only coincidentally beneficial to society in general. The recent shift in attitudes of both these political combatants offers promise for improved environmental policies.
An improved synthesis of a fluorophosphonate-polyethylene glycol-biotin probe and its use against competitive substrates.

The fluorophosphonate (FP) moiety attached to a biotin tag is a prototype chemical probe used to quantitatively analyze and enrich active serine hydrolases in complex proteomes in an approach called activity-based protein profiling (ABPP). In this study we have designed a novel synthetic route to a known FP probe linked by polyethylene glycol to a biotin tag (FP–PEG–biotin). Our route markedly increases the efficiency of the probe synthesis and overcomes several problems of a prior synthesis. As a proof of principle, FP–PEG–biotin was evaluated against isolated protein mixtures and different rat-tissue homogenates, showing its ability to specifically target serine hydrolases. We also assessed the ability of FP–PEG–biotin to compete with substrates that have high enzyme turnover rates. The reduced protein-band intensities resulting in these competition studies demonstrate a new application of FP-based probes seldom explored before.
Phase transformation during low temperature Tl-diffusion in the fabrication of Tl-Ba-Ca-Cu-O thin films

Abstract In the two-step fabrication of Tl-Ba-Ca-Cu-O thin films, Tl 2 Ba 2 Ca 2 Cu 3 O 10 (Tl-2223) and Tl 1 Ba 2 Ca 2 Cu 3 O 9 (Tl-1223) films with good superconducting properties can be produced at a relatively low Tl-diffusion temperature. Our study shows that although a low annealing temperature generally favors the formation of Tl 2 Ba 2 Ca 1 Cu 2 O 7 (Tl-2212) superconducting film, Tl-2223 and Tl-1223 phases can still form by prolonging the annealing time. In fact, a prolonged annealing time leads to the transformation from Tl-2212 phase to Tl-2223 phase, and then to Tl-1223 phase. Therefore, the annealing time must be carefully controlled to get the needed superconducting phase.
REVIEW: Wild Rice: Both an Ancient Grain and a Whole Grain

ABSTRACT Wild rice (Zizania spp.) grows in shallow waters of North America and is distinct from brown and white rice (Oryza spp.). The recent trends toward gluten-free foods and ancient grains present an opportunity for increased interest in the health benefits of wild rice. Wild rice is classified as a whole grain and typically contains 75% carbohydrate, 6.2% dietary fiber, 14.7% protein, and 1.1% lipids. Wild rice is a good source of dietary fiber and has nearly double the amount of protein of white rice. The lipid content is low; however, most of the lipids are essential omega-6 (35.0–37.8%) and omega-3 (20.0–31.5%) fatty acids. In addition to macronutrient content, wild rice contains phytosterol levels several times higher than white rice. Furthermore, the antioxidant activity of wild rice is 10–15 times higher than white rice. A series of rat studies in which wild rice was added to a high fat, high cholesterol diet found significant attenuation of serum free fatty acids, total cholesterol, and trigly...
Expression of the α4 neuronal nicotinic acetylcholine receptor subunit in the developing mouse hippocampus

Neurotransmitters such as acetylcholine can control neuritogenesis of hippocampal cells. The timing of its receptors expression consequently may influence synaptogenesis and neuronal activity in the developing hippocampus. We investigated the mRNA expression of the nicotinic acetylcholine-gated ion channel receptor (nAChR) α4 subunit in the embryonic and postnatal hippocampal formation. Although its expression level is low in the adult hippocampus, this protein consitutes the major nAChR subunit in the central nervous system. We carried out in-situ hybridization experiments to determine whether or not the α4 AChR subunit mRNA distributions show evidence of regional and developmental regulation during hippocampal maturation. Our studies reveal that α4 AChR mRNA expression was low at the embryonic stage, but increased transiently during postnatal development reaching a maximum during the second week of life and decreasing thereafter, to a minimum at adulthood. In hippocampal regions, the peak values of α4 AChR expression were between 400 and 800% of adult α4 messenger levels. In the postnatal hippocampus, most of the cells from the pyramidal layer of the CA3 and CA2 areas displayed a strong hybridization signal for the α4 AChR subunit. In the hilus and the CA1 regions, the localization of the α4 transcripts seemed to be restricted to some interneurons and pyramidal cells, respectively. Moderate and uniform in-situ hybridization signals were observed in granular cells from the dentate gyrus. The transient profile of α4 expression suggests that nAChRs may participate in the early postnatal maturation of hippocampal circuity.
Competing Coupon Promotions and Category Sales

Recent reports show that manufacturers in many consumer product industries continue to use coupons as one of their main promotional tools. The rising intensity of coupon competitions, however, makes the issue of having better measures for coupon effects ever more important. This paper proposes a method to assess the category expansion effect in an environment where rival brands distribute coupons repeatedly over a period of time. A consumer utility maximization model is presented in which the decision of coupon use is endogenized along with the demand decision. Using single-source detergent data as benchmark, the proposed model is an advance over the conventional regression model in that the latter tend to produce upward-biased estimations for the category impact of coupons.
Molecular mechanism underlying ethanol activation of G-protein–gated inwardly rectifying potassium channels

Alcohol (ethanol) produces a wide range of pharmacological effects on the nervous system through its actions on ion channels. The molecular mechanism underlying ethanol modulation of ion channels is poorly understood. Here we used a unique method of alcohol-tagging to demonstrate that alcohol activation of a G-protein–gated inwardly rectifying potassium (GIRK or Kir3) channel is mediated by a defined alcohol pocket through changes in affinity for the membrane phospholipid signaling molecule phosphatidylinositol 4,5-bisphosphate. Surprisingly, hydrophobicity and size, but not the canonical hydroxyl, were important determinants of alcohol-dependent activation. Altering levels of G protein Gβγ subunits, conversely, did not affect alcohol-dependent activation, suggesting a fundamental distinction between receptor and alcohol gating of GIRK channels. The chemical properties of the alcohol pocket revealed here might extend to other alcohol-sensitive proteins, revealing a unique protein microdomain for targeting alcohol-selective therapeutics in the treatment of alcoholism and addiction.
Phosphomannoisomerase, an SH-Dependent Metal-Enzyme Complex

PHOSPHOMANNOISOMERASE was found in red cells of the pig. The enzyme catalyses the reaction mannose-6-phosphate ⇌ fructose-6-phosphate Enzyme activity was determined by measuring the rate of formation of fructose-6-phosphate. The method was as follows: 1 vol. packed cells + 4 vol. ice-cold distilled water were frozen and thawed several times. 1.0 ml. of this haemolysate, corresponding to 0.2 ml. original packed cells, 1.0 ml. acetate buffer, 0.1 M, pH 5.6, and 1.0 ml. mannose-6-phosphate (sodium salt 0.03 M, pH 5.9) were kept at 37° C. for the appropriate time and deproteinized by the addition of 3.0 ml. ice-cold 10 per cent perchloric acid. The deproteinizing agent was added to the blank before mannose-6-phosphate. The method of Roe1 was chosen for the determination of fructose-6-phosphate in the filtrates. Because of the big excess of phosphoglucoisomerase in red cells2 the fructose-6-phosphate measured is in equilibrium with glucose-6-phosphate at any stage of the reaction (60 and 40 per cent of glucose-6-phosphate and fructose-6-phosphate respectively at 37° C.) This was confirmed by determinations of glucose-6-phosphate with triphosphopyridine nucleotide and Zwischenferment3 and colorimetric measurements of fructose-6-phosphate in corresponding filtrates. The total original amount of fructose-6-phosphate was calculated by multiplication of that found by 2.5.
Biosynthesis: A new (old) way of hijacking tRNA.

Aminoacylation of tRNA is the cellular process for providing aminoacyl donors for the ribosome synthesis of polypeptides. New research highlights an unexpected structural overlap between enzymes involved in this process and those involved in the biosynthesis of cyclodipeptides, an important class of bioactive molecules.
Shape Optimization of Electrodes for Piezoelectric Actuators

This paper describes a method of shape optimization for electrodes used in piezoelectric actuators. This work is motivated by recent attempts to design piezoceramic bimorph actuators for the optimal control of two-dimensional flow fields. It has been observed experimentally that uniformly-electroded bimorphs induce undesirable three-dimensional effects into the flow. These effects complicate the optimal flow control problem considerably. Therefore, the objective is to design an electrode that is shaped in such a manner as to minimize three-dimensional effects while providing maximum actuator deflection. This paper considers electrode shape optimization for a typical two-layer composite transducer (unimorph) structure, which takes the form of a small, rigidly-clamped flap. The strong and weak forms of the governing equations of motion are derived for this system, which can be approximated as a thin plate. The finite element method is used to determine the dynamic flap response for a given electrode shape and voltage input. The optimization problem entails determining the electrode shape that, for a prescribed voltage input, minimizes the three-dimensional distortion at the trailing edge of the flap. Constraints are enforced that guarantee that the electrode shape is relatively smooth and that the electrode coverage is large enough to provide sufficient flap deflection. Theoretical results are presented that prove the existence of a solution when the shape optimization problem is formulated in this manner. Numerical results are given that validate the theory and illustrate the qualitative behavior of the shape optimization method. For the static case, the results are compared with those obtained in previous work using an ad hoc optimization algorithm that is not rigorously consistent with the shape optimization theory. Results are also given for the dynamic case in which the time-dependent response to a prescribed voltage input is considered.
Magnetic field characterization of high T/sub c/ YBCO superconducting weak links

We report measurements of the voltage across a weak link as a function of applied magnetic field. This measurement provides a sensitive probe of the quality of a weak link, as exhibited by the uniformity of the critical current density across it. Much more structure was found in the current density across longer links, and hysteresis due to flux trapping is evident. Deviations from a uniform critical current density were observed even in very short (4 /spl mu/) links.
Lack of effect of a behaviorally active dose ofα-melanotropin on biochemical indices of dopaminergic neuronal activity in the rat

An attempt was made to correlate behavioral changes in the male rat following an intracerebroventricular (ICV) injection ofα-melanotropin (α-MSH, 10μg) with biochemical estimates of the activities of nigrostriatal, mesolimbic, tuberoinfundibular and tuberohypophyseal dopaminergic neurons. ICV injection ofα-MSH elicited body snaking, stretching, yawning and penile erections. The concentrations of dopamine (DA) and dihydroxyphenylacetic acid and the rate of DA synthesis (accumulation of DOPA after the inhibition of DOPA decarboxylase) in the striatum, nucleus accumbens, olfactory tubercle, septum, median eminence and posterior pituitary were unaltered at any time (30–180 min) after ICV injection ofα-MSH. Intraperitoneal injection ofα-MSH (100μg/kg) also failed to change the rate of DOPA accumulation in these brain regions. These results imply that the behaviors observed afterα-MSH are not associated with changes in the activity of DA neurons.
The politics of wire service photography: Infrastructures of representation in a digital newsroom

This article examines the politics of image brokering in the daily rituals of a major wire service’s photography division. Specifically, it investigates crises of visualization: moments when routine visualization itself is challenged due to changes in infrastructures of representation. The transition to digital transmission has changed work of image brokers—people involved in the creation, validation, packaging, and circulation of images. New image brokers and changed infrastructures of representation challenge established hierarchies and who provides and polices news images. At a moment when the war on terror is also a war of images, battles over the infrastructures of representation are battles over visual worldmaking. [digital, infrastructure of representation, photography, Agence France Presse, journalism, crisis of representation, wire service, visualization, Iraq] E very day at around 9:25 a.m., someone would yell, “Shall we go up?” and two representatives from “Photo” at Agence-France Presse (AFP) would ride the small, arthritic elevator up to the morningmeetingonthefifthflooroftheagency’sParisheadquarters. The jovial air and constant jokiness of the photo department would follow them onto the elevator but adjust to the more muted tone of the text services as soon as they entered the meeting room, not much largerthanthetableinit.There,theywouldjointheeditor-in-chief,flanked by two text editors—one responsible for France and the other for International. The International text editor sat next to the International photo editor, and the respective France editors did the same. Around the table were representatives of the various sections—Economics, Sports, Politics, Arts and Culture, et cetera. Collectively, they reviewed the day’s news prospects. The editor-in-chief routinely began the meeting with “Qu’est-ce que c’est le dominant?” [What is the dominant?]. 1 In the context of the daily high-level meeting at one of the world’s largest wire news services, the question elicited information that would then shape the next day’s major headlines on the front pages of AFP subscribers’ publications around the world. The wording of this routine question emphasizes the constant hierarchies being evaluated in the production and circulation of news. At a wire service, what is being evaluated is a news story’s perceived importance. Whereas individual publications, such as the Yomuiri Shimbun, the Times of India, TIME, or Bild, might decide their coverage on the basis of imagined reader interest or marketability, the debates about which of the many news stories of the day should dominate thewireservice’scoveragearephrasedintermsofglobalsignificance. 2 Wire services function as journalistic wholesalers, and their subscribers pay not for coverage of individual stories but for access to the wire “feed.” For one story to be dominant, literally to be the most influential, to exercise authority over others, other stories need to be dominated, given less priority. This daily call and response dictates the reporting for the next 24 hours.
Smart help for operator performance

Abstract Our emphasis in this paper has been on the knowledge-based and cognitive issues pertinent for improved interactions between workers and manufacturing computer systems. We believe that these techniques are as necessary and applicable to manufacturing as to any other vocation, especially as the difference in collar color of shop people becomes less noticeable in their increasing role as knowledge workers.
Protein kinase C: regulation of serotonin release from rat brain cortical slices.

Abstract The effects of phorbol esters on serotonin release were examined in an attempt to investigate the role of protein kinase C in the regulation of serotonin release. Rat brain parietal cortical slices were incubated with [ 3 H]5-HT in the presence of pargyline in order to label the serotonin stores. Potassium stimulated (30 s) release and spontaneous [ 3 H]5-HT efflux were examined in slices during superfusion with Krebs-Ringer solution containing chlorimipramine. Repeated K + stimulations elicited reproducible responses with release ratios of approximately 1.0. Introduction of phorbol 12-myristate,13-acetate (PMA) or phorbol 12,13-dibutyrate (PDBu) 20 min prior to S 2 , or S 3 resulted in dose-related increases in [ 3 H]5-HT or [ 3 H]NE release. PMA was slightly more potent (93% increase) than PDBu in potentiating K + -stimulated [ 3 H]5-HT release. Phorbol and 4α-phorbol 12,13-didecanoate (4αPDD) which do not activate protein kinase C did not alter serotonin release. In contrast, basal [ 3 H]5-HT and [ 3 H]NE release were altered to a far lesser extent which was not always dose related. The response to the phorbol esters was reversible, Ca 2+ -dependent and reached maximal effect after 20 min of superfusion. The putative protein kinase C inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7) inhibited K + -induced [ 3 H]5-HT release significantly (11%) but did not alter basal efflux. The PMA facilitation of serotonin release was, however, markedly prevented by the enzyme inhibitor. The effect of PMA on release was found not to be directly mediated through the prejunctional serotonin autoreceptors. This is suggested by (1) the similarity in PMA-induced release potentiation observed in the presence or absence of the serotonin agonist, 5-methoxytryptamine, and (2) by the inability of the kinase inhibitor, H-7, to alter K + -stimulated release by the serotonin receptor antagonist, methiothepin. These results on serotonin and norepinephrine release and those of previous workers dealing with other transmitters point to an important role of protein kinase C in the modulation of neurotransmitter release in the central nervous system.
Variability in Green-Ampt effective hydraulic conductivity under fallow conditions

Hydraulic conductivity of the soil matrix dynamically responds to changes in the surrounding environment. Therefore, infiltration parameters for the Green-Ampt equation should change for each storm event in continuous simulation models. This study focused on improving Water Erosion Prediction Project (WEPP) model estimates of runoff using over 220 plot-years of natural runoff plot data from 11 locations. By optimizing the effective Green-Ampt hydraulic conductivity, Ke, for each event within the simulation, a method of correlating hydraulic conductivity on any given day to many other parameters was established. Factors with significant correlation to optimized values of Ke fell into three distinct categories; (1) factors related to soil crusting and tillage; (2) factors related to event size; (3) factors related to antecedent moisture conditions. Equations were developed to represent the temporal variability of hydraulic conductivity for each group. The equation describing the decrease in hydraulic conductivity owing to crusting used an exponential decay function based primarily on cumulative rainfall kinetic energy since last tillage, a soil stability factor, and a crust factor. The relationship between hydraulic conductivity and event size was characterized using an exponential relationship with total rainfall kinetic energy. The final adjustment used the moisture content immediately below the infiltration zone to account for the influence of antecedent moisture conditions on optimized hydraulic conductivities. All three adjustments were incrementally incorporated into WEPP and each improved the average model efficiency.
Reducibility and Surface Area of Coprecipitated Supported Nickel Methanation Catalysts

A study on the effect of reducing temperature and time on the N2 BET surface area and the H2 chemisorption metal surface area of a range of alumina and silica supported nickel methanation catalysts is described. Increasing the reduction temperature from 400 to 600 °C generally decreases the N2 BET surface area. The effect is more marked in the silica supported catalysts. The reduced metal surface area increases in the silica supported catalysts as the temperature increases from 400 to 600 °C. In the alumina supported catalysts the metal surf ace area increases from 400 to 500 °C, but decreases from 500 to 600 °C. The fraction of nickel that is reduced increases as the reduction temperature increases.
DIFFERENTIAL PRICING AND SEGMENTATION ON THE INTERNET: THE CASE OF HOTELS

In the ever‐changing electronic environment of the twenty‐first century, price is one of the key strategic elements that is often overlooked by firms. The paper addresses differential pricing in business‐to‐consumer electronic commerce, in particular differential pricing for hotel services sold on the Internet. Hotels are able to take advantage of differential pricing for various segments because the market for hotels can be divided into narrow customer segments. An overview of e‐commerce and Internet marketing is provided. The characteristics of products sold online and differential pricing are discussed. Pricing policies for on‐line marketing are examined with a special emphasis on differential pricing, customer loyalty and segmentation. With the help of secondary data, online pricing strategies used by hotels on the Internet are evaluated. Finally, conclusions are drawn and implications for the hotel industry are discussed.
A coupled enzymatic method to measure blood lactate by amperometric monitoring of the rate of oxygen depletion with a Clark oxygen electrode.

Abstract A rapid, sensitive and reliable method to measure lactate in blood is described. The method is based on the enzymatic oxidation of lactate to pyruvate in the presence of nicotinamide adenine dinucleotide (NAD + ) and lactate dehydrogenase (LDH). The reaction product, NADH, is then oxidized by molecular oxygen, carried in the buffered reagent medium, in the presence of horseradish peroxidase and other cofactors. The maximum rate of oxygen depletion, which is directly proportional to the amount of lactate ion present in the sample, is amperometrically monitored by a membrane oxygen electrode. No sample pretreatment is required in the present procedure other than dilution, and a comparison study between the described method and a spectrophotometric method shows good correlation.
CORRELATED EVOLUTION OF GENOME SIZE AND CELL VOLUME IN DIATOMS (BACILLARIOPHYCEAE)1

A correlation between genome size and cell volume has been observed across diverse assemblages of eukaryotes. We examined this relationship in diatoms (Bacillariophyceae), a phylum in which cell volume is of critical ecological and biogeochemical importance. In addition to testing whether there is a predictive relationship across extant species, we tested whether evolutionary divergences in genome size were correlated with evolutionary divergences in cell size (using independent contrasts). We estimated total DNA content for 16 diatom species using a flow cytometer and estimated cell volumes using critical dimensions with scaling equations. Our independent contrast analyses indicated a significant correlated evolution between genome size and cell volume. We then explored the evolutionary and ecological implications of this evolutionary relationship. Diatom cell volume is an important component of the global carbon cycle; therefore, understanding the mechanisms that drive diatom genome evolution has both evolutionary and ecological importance.
Pharmacokinetics of sodium phenylacetate and sodium benzoate following intravenous administration as both a bolus and continuous infusion to healthy adult volunteers.

Abstract Background: Ammunol ® (sodium phenylacetate/sodium benzoate) is an intravenously administered, investigational drug used for the treatment of acute hyperammonemia in infants, children, and adults with urea cycle enzyme deficiencies. A pharmacokinetic study of sodium phenylacetate/sodium benzoate (NAPA/NABZ) was performed in two groups of normal healthy volunteers, following the dosing regimen used to treat hyperammonemia. Methods: The first group of subjects ( n =3) received a bolus dose of 5.5g/m 2 of NAPA/NABZ, over a period of 1.5h. Following a seven-day washout, subjects then received the same bolus dose, followed by a continuous infusion of 5.5g/m 2 over 24h. A second group of different subjects ( n =17) received the same treatment regimen, but using doses of 3.75g/m 2 . Phenylacetate (PA) and benzoate (BZ), and their respective metabolites, phenylacetylglutamine (PAG), and hippurate (HIP) were measured over a 24-h period. An HPLC method was used for the measurement of all analyte concentrations. Non-compartmental analysis and modeling was performed using WinNonlin Professional ® . Results: Both BZ and PA displayed saturable, non-linear elimination, with a decrease in clearance with increased dose. During the bolus dose with continuous infusion regimen, plasma levels of both BZ and PA peaked at the end of the priming dose, and PA levels remained near peak for 5–9h. In contrast, BZ plasma levels immediately fell following the priming dose, and became undetectable at 14.1±4.2 and 26.8±2.3h in the low- and high-dose group, respectively. The formation of HIP occurred more rapidly than that of PAG. For both PA and BZ, metabolite formation increased in a linear fashion with the dose. Conclusion: These data describe the pharmacokinetics of PA and BZ, and their respective metabolites, as observed in healthy adult volunteers, with the higher dose studied equivalent to that used to treat hyperammonemia. Dose optimization is required to maximize nitrogen removal, while minimizing the risk of toxicity, especially due to PA. Because of the slower elimination of PA, and the non-linear pharmacokinetic behavior displayed by both PA and BZ, only investigational protocol-specific doses should be used, and higher doses should be avoided unless blood level monitoring can be done promptly and frequently.
Introduction to the role of excitatory amino acids in the actions of abused drugs: A symposium presented at the 1993 annual meeting of the College on Problems of Drug Dependence

Recent evidence has demonstrated that N-methyl-d-aspartic acid (NMDA) and non-NMDA, excitatory amino acid (EAA) receptor antagonists block the motor stimulating, neurotoxic, and rewarding actions of cocaine and the amphetamines. The participants in this symposium discussed evidence that (i) the initiation of stimulant-induced behavioral sensitization involves NMDA receptor stimulation in the ventral tegmental area (VTA), (ii) competitive and non-competitve NMDA antagonists block the dopaminergic neurotoxic actions of methamphetamine, and (iii) NMDA receptor antagonists block cocaine and methamphetamine-induced increases in striatal neurotensin and dynorphin expression. Furthermore, a theoretical framework was proposed in which to interpret dopamine-glutamate interactions based on tonic and phasic dopamine release in the striatum under acute, chronic and withdrawal states of stimulant exposure.
Effect of α-methyl-p-tyrosine on the incidence of spontaneous convulsions observed following barbital withdrawal

Abstract Male Sprague-Dawley rats were made dependent on barbital by the administration of this drug in the drinking water following an established dosage regimen. Following abrupt barbital withdrawal, the incidence of convulsions was determined in barbital-dependent rats. Groups of these animals were treated with saline, 30, 60, 125 or 250 mg/kg α-methyl-para-tyrosine (αMPT) at the time of barbital withdrawal and a second time 16 hr later. A statistically significant (P
Micellar Fluidity and Preclouding in Mixed Surfactant Solutions

The fluorescence anisotropy of perylene and the native fluorescence of Igepal CO-630 and Triton X-114 were used to study the intramicellar fluidity of mixed micellar solutions containing these noni...
Thermodynamics: Highs and lows in the density of water

Water contracts when it is cooled but, unlike other liquids, it then starts to expand at temperatures a few degrees above the melting point of ice. However, a new experimental study suggests that normal behaviour returns if the water is supercooled to low enough temperatures.
Sphingosine 1-Phosphate Stimulates Cell Migration through a Gi-coupled Cell Surface Receptor POTENTIAL INVOLVEMENT IN ANGIOGENESIS

Sphingosine 1-phosphate (SPP) has been shown to inhibit chemotaxis of a variety of cells, in some cases through intracellular actions, while in others through receptor-mediated effects. Surprisingly, we found that low concentrations of SPP (10-100 nM) increased chemotaxis of HEK293 cells overexpressing the G protein-coupled SPP receptor EDG-1. In agreement with previous findings in human breast cancer cells (Wang, F., Nohara, K., Olivera, O., Thompson, E. W., and Spiegel, S. (1999) Exp. Cell Res. 247, 17-28), SPP, at micromolar concentrations, inhibited chemotaxis of both vector- and EDG-1-overexpressing HEK293 cells. Nanomolar concentrations of SPP also induced a marked increase in chemotaxis of human umbilical vein endothelial cells (HUVEC) and bovine aortic endothelial cells (BAEC), which express the SPP receptors EDG-1 and EDG-3, while higher concentrations of SPP were less effective. Treatment with pertussis toxin, which ADP-ribosylates and inactivates G(i)-coupled receptors, blocked SPP-induced chemotaxis. Checkerboard analysis indicated that SPP stimulates both chemotaxis and chemokinesis. Taken together, these data suggest that SPP stimulates cell migration by binding to EDG-1. Similar to SPP, sphinganine 1-phosphate (dihydro-SPP), which also binds to this family of SPP receptors, enhanced chemotaxis; whereas, another structurally related lysophospholipid, lysophosphatidic acid, did not compete with SPP for binding nor did it have significant effects on chemotaxis of endothelial cells. Furthermore, SPP increased proliferation of HUVEC and BAEC in a pertussis toxin-sensitive manner. SPP and dihydro-SPP also stimulated tube formation of BAEC grown on collagen gels (in vitro angiogenesis), and potentiated tube formation induced by basic fibroblast growth factor. Pertussis toxin treatment blocked SPP-, but not bFGF-stimulated in vitro angiogenesis. Our results suggest that SPP may play a role in angiogenesis through binding to endothelial cell G(i)-coupled SPP receptors.
A new method for quantification of liquid saturation in 2D translucent porous media systems using light transmission

Abstract Five physically based models for predicting liquid saturation from light transmission in 2D laboratory systems containing translucent porous media were developed and tested (Models A–E). The models were based upon various simplifying assumptions concerning pore geometry, wettability, and drainage. Models A–D assumed uniform-sized pores, and liquid saturation was an explicit function of light transmission. Model E considered a distribution of pore sizes whose drainage characteristics were inferred from the Laplace equation. Mass balances were calculated using data from drainage and infiltration experiments, in four textures of silica sand with water as the fluid. Model E performed the best overall, with systematic errors of less than 2.3% saturation. Model E represents a robust easily applied new method for the determination of liquid saturation by light transmission. The other four models are presented, and compared, for reasons of historical interest and to investigate the impact of the various simplifying assumptions.
ENDOTHELIUM-DEPENDENT VASODILATORS DO NOT CAUSE PROPAGATED INTERCELLULAR CA2+ WAVES IN VASCULAR ENDOTHELIAL MONOLAYERS

Local application of a number of vasoactive agents affects vasomotor tone not only downstream to the point of application but also upstream. The mechanism(s) of upstream propagation is unknown. In endothelial cell monolayers, mechanical stimulation of one cell leads to intercellular propagation of increases in endothelial cell (EC) [Ca2+]i. In this study, we tested whether increases in EC [Ca2+]i induced by the local application of the endothelium-dependent vasodilators ATP, bradykinin and acetylcholine could spread across the monolayer. We demonstrate that unlike the response seen to a mechanical stimulus, there was no significant propagation of increases in EC [Ca2+]i levels in response to localized application of these agents. These findings suggest that upstream vasodilation in response to endothelium-dependent vasodilators is not mediated by propagation of EC [Ca2+]i waves and suggest that other electrical or chemical signals are responsible.
Inhibition of DNA double-strand break repair by the Ku heterodimer in mrx mutants of Saccharomyces cerevisiae

Abstract Yeast rad50 and mre11 nuclease mutants are hypersensitive to physical and chemical agents that induce DNA double-strand breaks (DSBs). This sensitivity was suppressed by elevating intracellular levels of TLC1, the RNA subunit of telomerase. Suppression required proteins linked to homologous recombination, including Rad51, Rad52, Rad59 and Exo1, but not genes of the nonhomologous end-joining (NHEJ) repair pathway. Deletion mutagenesis experiments demonstrated that the 5′-end of TLC1 RNA was essential and a segment containing a binding site for the Yku70/Yku80 complex was sufficient for suppression. A mutant TLC1 RNA unable to associate with Yku80 protein did not increase resistance. These and other genetic studies indicated that association of the Ku heterodimer with broken DNA ends inhibits recombination in mrx mutants, but not in repair-proficient cells or in other DNA repair single mutants. In support of this model, DNA damage resistance of mrx cells was enhanced when YKU70 was co-inactivated. Defective recombinational repair of DSBs in mrx cells thus arises from at least two separate processes: loss of Mrx nuclease-associated DNA end-processing and inhibition of the Exo1-mediated secondary recombination pathway by Ku.