cssi/SciSciGPT-SciSciNet huggingface dataset:
Reduced GABA Concentration in Attention-Deficit/Hyperactivity Disorder

Context Attention-deficit/hyperactivity disorder (ADHD) is a developmental disorder characterized by a deficit in behavioral inhibition. Recent evidence also suggests a deficit in cortical inhibition via the GABA (γ-aminobutyric acid)–ergic system. Objective To investigate the GABAergic component of ADHD using magnetic resonance spectroscopy. Design Cross-sectional study. Setting Participants were recruited through local schools, local pediatric and other community clinics, and through advertisement in regional publications. Magnetic resonance spectroscopy was performed within the research institute. Participants Children (age range, 8-12 years) in a typically developing control group vs a group with ADHD were compared. Main Outcome Measures J-difference–edited magnetic resonance spectroscopy at 3 T was used to measure GABA concentration in a volume that included primary somatosensory and motor cortices. Results GABA concentration is reduced in children with ADHD compared with typically developing control subjects. Conclusion Our finding of reduced GABA concentration in ADHD is concordant with recently reported deficits in short intracortical inhibition in ADHD and suggests a GABAergic deficit in ADHD.
Structural transitions in micellar solutions of pluronic P-105 and their effect on the conformation of dissolved cytochrome C: An electron paramagnetic resonance investigation☆

Abstract Multimolecular micelles formed in aqueous solutions by some members of the Pluronic copolymer family have the potential to be used as drug vehicles. Structural transitions in Pluronic P-105 solutions at increasing Pluronic concentrations were monitored by a spin-probe technique. Electron paramagnetic resonance data revealed reversible transitions from Pluronic unimers to small and loose molecular aggregates to dense multimolecular micelles. The transition to multimolecular micelles started at a Pluronic concentration of about 1 wt.% and was completed at the concentration of 10 wt.%, with two populations of micelles coexisting at intermediate concentrations. Conformational changes of the membrane protein Cytochrome C in interaction with Pluronic solutions were investigated by the spinlabeling technique. The rotational correlation time of a spin label located near the surface of Cytochrome C, and the distance between the nitroxyl moiety and the heme iron of Cytochrome C depended on Pluronic concentration indicating protein conformational changes in Pluronic solutions.
The Preparation and Properties of the Perchlorates of Some Choline Esters

The preparation and properties of acetyl, benzoyl, furoyl, and thenoyl choline perchlorates are described. It is shown that perchloric acid may be used to isolate choline esters from their reaction mixtures.
Development and characterization of an interleukin-2–transduced human ovarian carcinoma tumor vaccine not expressing major histocompatibility complex molecules

Abstract OBJECTIVE: We initiated studies to develop cytokine-secreting human ovarian carcinoma cells for the purpose of using these cells as vaccines for the treatment of advanced epithelial ovarian cancer. STUDY DESIGN: A human ovarian carcinoma cell line (UCI-107) was genetically engineered to secrete the cytokine interleukin-2 by retroviral-mediated gene transduction. RESULTS: One clone, termed UCI-107A IL-2 AS, constitutively secreted high levels of interleukin-2 (i.e., 2000 to 2300 pg/ml/105 cells per 48 hours) for >55 passages and 8 months of study. Unlike parental- and vector-transduced cells, UCI-107A IL-2 AS cells were aneuploid and failed to express major histocompatibility complex class I and HER2/neu surface antigens. UCI-107A IL-2 AS cells were highly resistant to killing by gamma irradiation and continued to produce high levels of interleukin-2 even after irradiation with 10,000 cGy. Balb/C nude mice injected intraperitoneally with UCI-107A IL-2 AS cells survived significantly longer than control animals, with 25% of the animals totally rejecting their tumors. UCI-107A IL-2 AS was totally resistant to killing by fresh allogeneic peripheral blood lymphocytes in four hour chromium 51 release assays but induced high levels of killing in 72-hour long-term cytotoxic assays. CONCLUSION: The potential use of these interleukin-2 - secreting ovarian carcinoma cells as vaccines for women with advanced ovarian cancer will be discussed. (AM J OBSTET GYNECOL 1996;174:633-40.)
PORSEL: an expert system for assisting in investment analysis and valuation

During the last few years, we have developed an expert system, called PORSEL (PORtfolio SELection system), which uses a small set of rules to select stocks. PORSEL consists of three components: the Information Center, the Fuzzy Stock Selector, and the Portfolio Constructor. The purpose of the information center is to provide representation of several technical indicators such as candlestick charts, moving average of closing prices, and price trends. The fuzzy stock selector evaluates the listed stocks and then assigns a composite score for each stock. The portfolio constructor generates the optimal portfolios for the selected stocks. The PORSEL also includes a user-friendly interface for adding and deleting rules during the run time. The results of simulation shows that PORSEL outperformed the market almost every year during the testing period.
Effect of ibogaine on serotonergic and dopaminergic interactions in striatum from mice and rats.

The effect of ibogaine (Endabuse™, NIH 10567) on serotonin uptake and release, and on serotonergic modulation of dopamine release, was measured in striatal tissue from rats and mice. Two hours after treatment in vivo with ibogaine (40 mg/kg i.p.), the uptake of labeled [3H]serotonin and [3H]dopamine uptake in striatal tissue was similar in the ibogaine-treated animal to that in the control. The 5HT1B agonist CGS-12066A (10−5 M) had no effect on stimulation-evoked tritium release from mouse or rat striatal tissue preloaded with [3H]serotonin; however, it elevated tritium efflux from striatal tissue preloaded with [3H]dopamine. This increase was not seen in mice treated with ibogaine 2 or 18 hours previously, or in rats treated 2 hours before. Dopamine autoreceptor responses were not affected by ibogaine pretreatment in either mouse or rat striatal tissue; sulpiride increased stimulation-evoked release of tritium from tissue preloaded with [3H]dopamine. The long-lasting effect of ibogaine on serotonergic functioning, in particular, its blocking of the 5HT1B agonist-mediated increase in dopamine efflux, may have significance in the mediation of its anti-addictive properties.
Asking the Right Questions: Successful University Consultation in Public Schools

University professors can provide successful consultation to schools by learning to work effectively with administrators to remove roadblocks that prevent effective inservice. The questions suggested here may focus both university faculty members and school administrators on outcomes that meet participants' expectations.
Cerebrospinal Fluid Acetylcholinesterase in Neuropsychiatric Disorders

Acetylcholine (ACh) may be involved in a number of behavioral disorders.9 Therefore, with respect to investigations of the cholinergic system in neurological and psychiatric disorders, Cholinesterase (ChE), the enzyme that degrades ACh, would be one parameter of interest. This chapter focuses on findings with respect to esterases of the cholinergic system and their measurement in cerebrospinal fluid (CSF).
Analysis of common mutations and associated haplotypes in Chinese patients with glucose-6-phosphate dehydrogenase deficiency.

Glucose-6-phophate dehydrogenase (G6PD) deficiency is a rare disease in North China. In the present investigation, DNA samples from 17 patients with G6PD deficiency from Tianjin area in North China were studied for the two G6PD common mutations (R459L and R463H) and two single nucleotide polymorphisms (1311C/T and 1365-13T/C) using a dideoxy fingerprinting method. Five patients were positive for mutation R459L, and six patients were positive for mutation R463H. Further haplotype analyses using three flanking dinucleotide repeat polymorphism loci, DXS1123, DXS1113, and F8C(IVS 13), were performed on 14 patient families and 16 control Chinese females. The results indicated that the two common mutations were from different haplotypes. Also, the data suggested a possible allelic association between the two G6PD common mutations and the F8C(IVS13) locus and a different allelic distribution for loci DXS1113 and F8C(IVS13) between Chinese and Caucasian populations.
Between Scholarship and Polemic in Judeo-Islamic Studies

Beyond Religious Borders: Interaction and Intellectual Exchange in the Medieval Islamic World, edited by David M. Freidenreich and Miriam Goldstein, Philadelphia, University of Pennsylvania Press, ...
Reversible radiationless decay in methylglyoxal

Abstract We report an examination of the fluorescence decay of methylglyoxal vapor excited from the ground 1 A′(S 0 ) electronic state to the excited 1 A″(S 1 ) electronic state as a function of additive pressure and excitation wavelength. To explain the low-pressure behavior we postulate a kinetic model which includes a “reversible” collison-free intersystem crossing (S 1 -T 1 ) rate. Quantum mechanical considerations suggest that the optically excited single vibronic level is not coupled with pure T 1 levels.
Measurement of internal conversion electrons from Gd neutron capture

Abstract Gadolinium (Gd) is a suitable material for neutron conversion because of its superior neutron absorption cross-section. However, the principal secondary particles that generate electron-hole pairs in a semiconductor detector after Gd neutron capture are low-energy internal conversion (IC) electrons. We measured the IC electron spectrum due to Gd neutron capture by using a thermal neutron beam and a digitizer-based multidetector spectroscopy. We also discussed the effective use of the IC electrons in the context of a twin-detector design and the associated gamma-ray rejection issues. Extensive simulations of the spectra of IC electrons and gamma rays agreed well with the experimental results; both types of results support the feasibility of the proposed n – γ separation method.
Structures for Polymorphs of Triphenyl chloromethane. Triphenylacetic Acid Illustrates the Isomorphous Stable Modification

Abstract Triphenylacetic acid is isomorphous with the published structure of triphenylchloromethane (I). It crystallizes in the trigonal system, space group P3, with a=b=14.105(3)A, c=13.121(2)A V=2261(1)A3, Z=6 at 175K. The structure was solved by direct methods and refined to R(F 0)=0.062. We determined the structures for two triclinic polymorphs of triphenylchloromethane, II and III. The three forms were obtained from pentane evaporated at room temperature. Phases I and III were isolated from particular solvent systems. Crystal data (II): triclinic system, space group P3, with a=13.028(1)A, b=13.559(2)A, c=13.969(3)A, α=117.67(1)°, β=92.67(1)°, γ=91.43(1)°, V=2179.9A3, Z=6 at 228K. The structure was solved by direct methods and refined to R(F 0)=0.045. Crystal data (III): triclinic system, space group P3, with a=14.1562(4)A, b=21.3190(7)A, c=13.0654(5)A, α=99.92(3)°, β=92.68(3)°, γ=106.15(2)°, V=3712(2)A3, Z=10 at 248K. The structure was solved by direct methods and refined to R(F o)=0.064. A batch of ...
Central but not systemic administration of ghrelin induces wakefulness in mice.

Ghrelin is a brain-gut peptide hormone widely known for its orexigenic and growth hormone-releasing activities. Findings from our and other laboratories indicate a role of ghrelin in sleep regulation. The effects of exogenous ghrelin on sleep-wake activity in mice are, however, unknown. The aim of the present study was to determine the sleep-modulating effects of ghrelin after central and systemic administrations in mice. Sleep-wake activity after intracerebroventricular (icv) administration of 0.2, 1 and 5 µg ghrelin and intraperitoneal injections of 40, 100, and 400 µg/kg ghrelin prior to light onset were determined in C57BL/6 mice. In addition, body temperature, motor activity and 1-hour food intake was measured after the systemic injections. Sleep effects of systemic ghrelin (40 and 400 µg/kg) injected before dark onset were also determined. Icv injection of ghrelin increased wakefulness and suppressed non-rapid-eye-movement sleep and electroencephalographic slow-wave activity in the first hour after injections. Rapid-eye-movement sleep was decreased for 2–4 hours after each dose of ghrelin. Sytemic administration of ghrelin did not induce changes in sleep-wake activity in mice at dark or light onset. Motor activity and body temperature remained unaltered and food intake was significantly increased after systemic injections of ghrelin given prior the light period. These findings indicate that the activation of central, but not peripheral, ghrelin-sensitive mechanisms elicits arousal in mice. The results are consistent with the hypothesis that the activation of the hypothalamic neuronal circuit formed by ghrelin, orexin, and neuropeptide Y neurons triggers behavioral sequence characterized by increased wakefulness, motor activity and feeding in nocturnal rodents.
The significance of low thyroid reserve.

In a previous report from this clinic (1) the value of a test utilizing the effect of a single intramuscular injection of thyroid-stimulating hormone (TSH) in the diagnosis of obscure hypothyroidism was presented. Of 37 patients tested because of suspected hypothyroidism, 3 were found to manifest a condition that had not previously been clearly recognized, and which was termed “low thyroid reserve.” It was characterized by a normal three-hour thyroidal uptake of I131 and serum protein-bound iodine (PBI) level, but a failure of either to respond to stimulation with TSH. It was attributed to the presence of a remnant of thyroid tissue which was being stimulated maximally by endogenous TSH and hence could not respond further to the exogenous hormone administered in the test. Additional experiences with this condition were published in a subsequent brief report (2).
Behavioral and autonomic responses to intermittent social stress: differential protection by clonidine and metoprolol.

The present study investigated physiological and pharmacological characteristics of socially “stressed” animals. Specifically, we examined (1) to what degree autonomic and behavioral “stress” reactions during intermittent confrontations between an intruder male adult Long-Evans rat with an aggressive resident undergo habituation, and (2) to what extent the defeat-experienced animal can be protected against these “stress” reactions with clonidine or metoprolol, two adrenergic agents with clinical anxiolytic effects. We developed an acute social stress situation that consisted of initially placing an experimental rat as an intruder into the homecage of a resident while the resident was not present, thereafter permitting brief physical agonistic interactions with the reintroduced resident until the intruder was forced into a submissive supine posture and emitted ultrasonic vocalizations (USV), and eventually exposing the intruder to the resident's threats for one hour, while being shielded from potentially injurious attacks (“threat encounter”). Over the course of the initial 4-weekly threat encounters the acute tachycardia but not the hyperthermic stress responses decreased in magnitude. Following the first three threat encounters core temperature (Tc) was significantly elevated for at least 3 h. The Tc was already elevated when the repeatedly defeated intruder was confronted with the olfactory cues of the resident's cage. This conditioned “anticipatory” hyperthermia developed in the course of the first three confrontations and was paralleled by a decrease in exploratory and motor behavior and by an increase in defensive behaviors and in both types of USV emitted in the “low” (20–30 kHz) and the “high” (31–70 kHz) frequency range. Clonidine (0.01–0.1 mg/kg, IP), anα2-adrenergic agonist and metoprolol, a β-adrenergic blocker (1.0–10.0 mg/kg, IP), dose-dependently prevented the tachycardic response to stress. Only clonidine, but not metoprolol, also attenuated the rise in T0 during the 1-h agonistic interaction. Clonidine decreased those aspects of motor behavior (e.g. rearing, walking) that are of lesser “cost” for the individual but maintained high levels of defensive reactions and increased the duration of “low” USV. The high doses of clonidine (0.06, 0.1 mg/kg) attenuated the homeostatic regulation and sedated the intruder while exposed to threats during a social confrontation. The absence of attenuation of the high level of defensive behavior and the prolonged “low” USV suggest a stress intensification by the higher doses of clonidine. In conclusion, after the fourth encounter, the autonomic, behavioral and vocal response pattern prior to and during repeated weekly confrontations show no evidence for habituation for the following 6 weeks. Moreover, adrenergic therapeutic agents that are applied to treat symptoms of anxiety block the tachycardic response but may actually intensify defensive behavior and certain “stress” vocalizations.
Plasma bulk flow in Jupiter's dayside middle magnetosphere

Using the plasma data obtained during the Voyager 1 encounter and the full response function of the Plasma Science (PLS) experiment, convective plasma velocities have been determined in the dayside middle magnetosphere of Jupiter (r = 10-25 Jupiter radii). It is found that temperature anisotropies have very little effect on plasma velocity determination and that the plasma data are well approximated by convected, isotropic Maxwellian ion distribution functions. The insensitivity of the analysis to any thermal anisotropies which may exist allows a good determination of the bulk plasma flow velocity. In addition to the subcorotational azimuthal flow, there exists a substantial nonazimuthal component of plasma flow. This nonazimuthal flow is mostly aligned (antialigned) with the local magnetic field but also exhibits a cross-field component. The velocity pattern is inconsistent with enhanced plasma outflow in the active sector, as suggested by the corotating convection model of plasma transport. The contribution of field-aligned flow along the curved magnetic field lines to the stress on the magnetic field is evaluated. In the region studied, such flow contributes up to one half the stress produced by the azimuthal plasma flow.
Magnetic anomalies at high altitudes

To investigate the effect of anomalies in the Earth's magnetic field at high altitudes, aeromagnetic maps of two representative areas showing isanomalic curves for total intensity are projected to levels of 10 and 20 miles above the surface of a plane Earth. The projections are accomplished by numerical computations and by use of a magnetic-field projecting machine at the Naval Ordnance Laboratory. It is found that anomalies of 500 gammas near the surface of the Earth, in merging into neighboring anomalies, may produce effects of 100 gammas or more at an altitude of 20 miles.
HIGH SPEED RESONANT-CAVITY InGaAs/InAlAs AVALANCHE PHOTODIODES

The evolution of long-haul optical fiber telecommunications systems to bit rates greater than 10 GB/s has created a need for avalanche photodiodes (APDs) with higher bandwidths and higher gain-bandwidth products than are currently available. It is also desirable to maintain good quantum efficiency and low excess noise. At present, the best performance (f3dB ~ 15 GHz at low gain and gain-bandwidth product ~ 150 GHz) has been achieved by AlInAs/InGaAs(P) multiple quantum well (MQW) APDs. In this paper we report a resonant-cavity InAlAs/InGaAs APD that operates near 1.55 μm. These APDs have achieved very low noise (k equivalent to 0.18) as a result of the very thin multiplication regions that were utilized. The low noise is explained in terms of a new model that accounts for the non-local nature of impact ionization. A unity-gain bandwith of 24 GHz and a gain-bandwidth-product of 290 GHz were achieved.
State legislators' attitudes and voting intentions toward tobacco control legislation.

OBJECTIVES: This study describes state legislators' knowledge, attitudes, and voting intentions with regard to tobacco-related issues. METHODS: A cross-sectional survey of state legislators was conducted in North Carolina, Texas, and Vermont in 1994. RESULTS: Most legislators agreed that secondhand smoke can cause lung cancer in nonsmokers, and a majority believed that smokers are addicted to nicotine. More than 75% stated that they would support a measure to enforce laws preventing tobacco sales to youth. A majority of Texas and Vermont legislators supported an increase in the state cigarette excise tax; 43% of North Carolina legislators would support an increase if revenues were directed toward tobacco farmer diversification. CONCLUSIONS: State legislators believe tobacco to be addictive, and they support policies to protect youth from tobacco. Support for other legislative measures differs significantly across states.
Spontaneous symmetry breaking in de Sitter space

We study the vacuum structure of theφ4 theory in de Sitter space. We give the condition for the occurrence of vacuum degeracy and spontaneous symmetry breaking bothly in classical and quantized theories. We also give the wave function for each vacuum.
On stockpiling natural resources

Persistent and significant privately held stockpiles of minerals have long been an important empirical regularity in the United States. Such stockpiles would not rationally be held in a traditional Hotelling-style model, though firms could be willing to hold inventories if extraction costs are stock-dependent. More plausibly, if prices are stochastic, and sufficiently volatile, firms have an incentive to hold inventories to smooth production over time.
Foodways Transmission in the Standing Rock Nation

Effective foodways transmission is critical to maintain the food sovereignty of indigenous peoples. In order to determine their own foodways, indigenous communities have developed diverse systems to convey knowledge related to the procurement, preparation, distribution, and consumption of food. In recent years, community organizations are taking a more active role in facilitating foodways transmission. In the Standing Rock Nation of the northern Great Plains, several community organizations, including tribal government agencies, are creating opportunities for elders to share their knowledge about traditional foods. The impetus for these activities comes from elders themselves, who attribute high rates of diet-related diseases to a loss of knowledge about traditional foods. We conducted eighteen semi-structured interviews with elders and organizers in the midst of these activities to reflect on processes of foodways transmission, including the implications of facilitation by community organizations. Interv...
The Paradox of China’s Policy in Africa

In many cases it was China’s longstanding solidarity with several liberation movements in Africa in the colonial period which was later upgraded to bilateral and state-level diplomatic relations in the postcolonial era. However, the twenty-first century has also brought about quantitative and potentially qualitative changes in Sino-African relations which are more complex than what the advocates of stronger Sino-African relations (Sino-optimists) and proponents of disengagement (Sino-pessimists) seem to suggest. The defining patterns of China’s influence in Africa are either not yet fully crystallized or they come in paradoxical pairs. The essay spells out the manifestations of these paradoxes and what can be done under the circumstances to improve the African condition. The divergent schools of thought about the possible impacts of China’s increased activities in Africa seem not to be totally unrelated to their underlying assumptions about the causes of Africa’s unsuccessful modernization. The essay also explores these intellectual issues by focusing on the contradictory dimensions of Afro-Chinese relations.
Cloning and Expression of the Mouse Laminin γ2 (B2t) Chain, a Subunit of Epithelial Cell Laminin

We have isolated and sequenced the full-length cDNA for the mouse laminin γ2 chain and mapped it to mouse Chromosome 1 proximal to laminin γ1. The mRNA for the mouse γ2 spans 5.2 kb and codes for a 1192-residue amino acid polypeptide. The γ2 chain (formerly termed laminin B2t), a homologue of γ1 (formerly B2), lacks an N-terminal domain and has a shorter domain III in comparison to the laminin γ1 chain. The expression of the laminin γ1 and γ1 chains in both newborn and fetal mice was examined by both Northern analysis and in situ hybridization. mRNA for the laminin γ2 chain was expressed specifically by epithelial cells in many tissues with a particularly high level of expression in the tongue, hair follicles, lung and kidney. In contrast, a high level of expression of the laminin γ1 chain mRNA was seen in both epithelial and endothelial cells in these tissues. In addition, γ1 mRNA was expressed in other tissues such as the nasal septum, blood vessels, and the muscle of the tongue. Immunohistochemistry with an anti-γ2 IgG detected strong expression of the laminin γ2 chain in the basement membrane of the collecting tubules of the kidney and of the pancreas. Immunoprecipitation studies with antibodies to the γ2 chain detected three species at 165, 155 and 140 kDa in HT-1080 cell-conditioned media. This protein complex is characteristic of the kalinin (nicein/epiligrin) complex, and provides further evidence that these proteins are identical and that the γ2 chain is the subunit of the epithelial-cell-specific laminin.
Investment Criteria, Productivity and Economic Development: An Empirical Comment

Scarcely any subject in the recent literature on development has evoked as much interest and controversy as the quest for investment criteria.' The entire theoretical controversy, culminating in Eckstein's synthesis of Kahn's social marginal productivity approach with Galenson-Leibenstein's marginal reinvestment quotient, has been expertly summarized by Chenery.2 Much progress has admittedly been made, but no one as yet stands ready to dispute the Chenery judgment (of earlier vintage) that the relationship between the theory of production and growth remains "the most controversial aspect of the problem of economic development."3 Least of all Eckstein who admits that "the kind of planning horizon which [his] analysis presupposes, requires information of a sort which is never found in underdeveloped countries."4 And the chances of a moratorium for policy-makers in such countries remain dim. Much of the practical difficulty has centered about the relative merits of two major partial equilibrium approaches, one employing "static efficiency," in the sense of using given resources most effectively, the other "dynamic efficiency," in the sense of permitting a maximum margin for reinvestment. The purpose of this paper is to attempt to shed some light on this issue by bringing related empirical evidence to bear. The restricted nature of our inquiry should be emphasized. We are not concerned here with the criteria governing an over-all invest-
Inhibition of long-term potentiation by an antagonist of platelet-activating factor receptors.

BEHAVIORAL AND NEURAL BIOLOGY 54, 213--217 RAPID COMMUNICATION Inhibition of Long-Term Potentiation by an Antagonist of Platelet-Activating Factor Receptors S. DEL CERRO, A. ARAI, AND G. LYNCH 1 Center for the Neurobiology of Learning and Memory, Bonney Center, University of California, Irvine, CA 92717 Platelet-activating factor (PAF) is a potent membrane-derived agent that triggers shape change, secretion, and aggregation in blood platelets. It also causes increases in intracellular calcium levels and a variety of functional effects in cells other than platelets. Recent work indicates that PAF accumulates in brain during ischemia and convulsions (Kumar, Harvey, Kester, Hanahan, & Olson, 1988), that PAF receptors are found in synaptic membrane fractions, and that antagonists of the PAF receptor protect neurons from the pathophysiological effects of ischemia (see Marcheselli, Rossowska, Domingo, Braquet, & Bazan, 1990). The func- tions of PAF in brain are unknown but, in light of its effects on blood platelets, it is conceivable that the factor promotes structural changes in synapses. In support of this idea are reports that inhibitors of phos- p h o l i p a s e A2, the enzyme that catalyzes the initial steps of PAF syn- thesis, interfere with the induction of long-term potentiation (LTP) (Lin- den, Sheu, Murakami, & Routtenberg, 1987; Okada, Yamagishi, & Sugiyama, 1989), a type of physiological plasticity associated with mod- ifications of synaptic morphology. Here we describe experiments showing that a competitive antagonist of the PAF receptor blocks the formation of LTP. Hippocampal slices were prepared and maintained in an interface chamber using conventional techniques. An extracellular recording pi- pette was positioned in the apical dendritic zone (stratum radiatium) of field CAlb and two stimulating electrodes were placed into fields CAla and CAlc so as to activate separate populations of Schaffer-commissural axons. Responses were collected to single pulses delivered one/20s for 1 Supported by the Air Force Office of Scientific Research (AFOSR No. 89-0383). Cor- respondence and reprint requests should be Addressed to Dr. Gary Lynch, Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA 92717. Copyright © 1990 by Academic Press, Inc. All rights of reproduction in any form reserved.
Prebiotic Synthesis of Methionine

Methionine has been shown to be a product of the action of a spark discharge on a simulated primitive earth atmosphere containing CH4, N2, NH3, H2O, and H2S or CH3SH. Acrolein has also been shown to be a product of the discharge and is proposed as an intermediate in the prebiotic synthesis of methionine and of glutamic acid, homocysteine, homoserine, and α,γ-diaminobutyric acid.
Follicle flushing for oocyte retrieval: Targeted analysis for patients with few follicles

Recent meta-analyses suggest that flushing follicles during the oocyte retrieval is not beneficial for patients with a normal response to ovarian stimulation. The rate at which oocytes are recovered after flushing is not mathematically compatible with cumulus oocyte complexes always being free floating in the follicle. Furthermore, some residual fluid always remains in the follicle after aspiration. For patients with a small number of follicles, follicle flushing is likely to increase oocyte yield and the potential for pregnancy enough to be clinically significant.
Noninvasive angiography in preoperativeevaluation of complicated pediatric renal masses using phase contrast magnetic resonance angiography

Abstract Objectives To report a new technique called “phase contrast magnetic resonanceangiography” (PC MRA) utilizing phase contrast magnetic resonance imaging, for assessing the renal vasculature in relation to complicated pediatric renal masses. Methods Three-dimensional phase contrast gradient refocused pulse sequences wereobtained on four pediatric patients with complicated renal masses. Findings were compared to ultrasound and computed tomographic images and correlated with actual surgical anatomy. Results In all four cases PC MRA provided standard angiographic quality detail of the renal vascular anatomy. The PC MRA findings had a 100% correlation with surgical exploration and MRA proved to be approximately one third the cost of the standard angiographic technique. Conclusions Our experience with the use of PC MRA in children suggests that it canbe helpful in evaluating the vasculature of complicated pediatric renal masses. PC MRA utilizes current generation magnetic resonance units, is noninvasive, and does not require anesthesia. It may be especially useful in patients with hypersensitivity to contrast agents, in those with renal failure in whom contrast agents may be contraindicated, and is less expensive than standard angiography.
Yap5 Protein-regulated Transcription of the TYW1 Gene Protects Yeast from High Iron Toxicity

The budding yeast Saccharomyces cerevisiae responds to high cytosolic iron by inducing Yap5-mediated transcription. We identified genes regulated by Yap5 in response to iron and show that one of the genes induced is TYW1, which encodes an iron-sulfur cluster enzyme that participates in the synthesis of wybutosine-modified tRNA. Strains deleted for TYW1 do not show a phenotype in standard yeast medium. In contrast, overexpression of TYW1 results in decreased cell growth and induction of the iron regulon, leading to increased expression of the high affinity iron transporters. We identified a minimal domain of S. cerevisiae Tyw1 that is sufficient to induce the iron regulon. CCC1, a vacuolar iron importer, is a Yap5-regulated gene, and deletion of either CCC1 or YAP5 resulted in high iron sensitivity. Deletion of TYW1 in a Δccc1 strain led to increased iron sensitivity. The increased iron sensitivity of Δccc1Δtyw1 could be suppressed by overexpression of iron-sulfur cluster enzymes. We conclude that the Yap5-mediated induction of TYW1 provides protection from high iron toxicity by the consumption of free cytosolic iron through the formation of protein-bound iron-sulfur clusters.
Multicomponent cycling zone adsorption

Abstract Multicomponent cycling zone adsorption is studied both theoretically and experimentally using a low pressure liquid chromatography apparatus. A discrete staged equilibrium model is used to predict separations in the traveling wave mode of operation with pH as the cyclic variable. Experimental results with a glucose-fructose-water system were in qualitative agreement with theoretical predictions. Partial fractionation of glucose from fructose was achieved and a technique for obtaining pure glucose was developed. The theory is extended to predict what criteria are needed to obtain good separations by this technique. In addition a new approach for the separation of two solutes by cycling zone adsorption is presented.
In Vivo Growth Hormone Treatment Rapidly Stimulates the Tyrosine Phosphorylation and Activation of Stat3

The mechanisms by which GH regulates gene expression to alter growth and metabolism are unknown. We have demonstrated previously that in vivo GH treatment rapidly stimulates the tyrosine phosphorylation of multiple nuclear proteins and have identified the inducible transcription factor Stat1 (formerly Stat91) as one of the major GH-activated nuclear phosphoproteins. We now show that Stat3, a new member of the STAT (signal transducer and activator of transcription) family of transcription factors, is also phosphorylated on tyrosine residues and rapidly appears in the nucleus in response to GH. Activated Stat3 interacts with the naturally occurring c-sis-inducible element of the c-fos gene after GH treatment, as demonstrated by gel mobility shift assay, and is a component of gel-shifted bands A and B when the high affinity sis-inducible element is used as a probe. Our results suggest that multiple STAT proteins may mediate some of the pleiotropic effects of GH on gene expression.
Is There Completeness in Mathematics after Gödel

What do mathematicians do? There are many ways of approaching this question, but one kind of answer is easy to give. Mathematicians study structures of different kinds: for instance, natural numbers, real numbers (the continuum), geometrical structures, groups, lattices, topological spaces, etc. For these structures, they develop corresponding theories, such as number theory, real analysis (theories of measure and integration), Euclidean geometry, group theory, lattice theory, topology, etc. In the late nineteenth century, a large and central class of foundational problems came up concerning the nature, the basic assumptions, and the presuppositions of theories of this general kind. These problems included questions concerning the axiomatization of important mathematical theories, the definitions of their basic concepts (e.g., natural numbers, real numbers, different geometrical objects), the relation of these mathematical theories to logic, etc. These questions are clearly among the foundational problems which working mathematicians are likely to find relevant. Hilbert’s efforts in his axiomatization of elementary geometry constitute a representative example of this early foundational work.1
Some results on characterizing the edges of connected graphs with a given domination number

Abstract A dominating set for a graph G = ( V , E ) is a subset of vertices V ′ ⊆ V such that for all v ϵ V − V ′ there exists some u ϵ V ′ for which { v , u } ϵ E . The domination number of G is the size of its smallest dominating set(s). For a given graph G with minimum size dominating set D , let m 1 ( G , D ) denote the number of edges that have neither endpoint in D , and let m 2 ( G , D ) denote the number of edges that have at least one endpoint in D . We characterize the possible values that the pair ( m 1 ( G , D ), m 2 ( G , D )) can attain for connected graphs having a given domination number.
Some American Indian voices: Resources in intercultural rhetoric and interpretation

American Indian literature useful to the speech scholar and performer may be found in newspapers, magazines, journals, and diaries of the past and the present.
The Empowered Customer: User-Generated Content and the Future of Marketing

Abstract The boundaries that traditionally delineated the roles of consumers and firms are being blurred as users take on creative tasks that were previously managed solely by commercial firms. This paper argues that the user-generated content (UGC) created by these consumers represents a profound shift of power from firms to consumers. In order to better understand this changing landscape, as well as to distinguish the various types of UGC in which customers most commonly engage, and highlight the benefits and challenges associated with these types, we present a new UGC typology that takes into account the objectives that consumers pursue as well as the type of knowledge flow that is activated when consumers produce UGC. We draw on existing literature and use illustrative examples to explicate these UGC types and explore the implications of UGC for marketing thought and practice.
Leaving the Parental Home in Great Britain: A Comparative Perspective

A British birth cohort's experiences of leaving home are analyzed, and comparisons are made with leaving home patterns in the U.S. and Australia. Neither the fact nor the timing of leaving home can be understood without considering the reason for leaving. There are sharp differences between those who leave for education and those who leave to marry. The former leave earlier, come from higher status homes, have better academic records, and are more likely to return. Because, on average, women marry earlier than men, more women leave home by their mid-twenties and fewer return. All three societies show these differences, but the proportions leaving for the different reasons vary. Overall, Americans leave home earliest and are most likely to return, in part because more Americans than Australians or Britons first leave home for school. Observed societal differences are attributed to differences in the educational systems, but variations in youth employment and housing opportunities may also contribute.
Characterization of the CH 4 /H 2 /Ar high density plasma etching process for ZnSe

High density plasma etching of mercury cadmium telluride using CH4/H2/Ar plasma chemistries is investigated. Mass spectrometry is used to identify and monitor etch products evolving from the surface during plasma etching. The identifiable primary etch products are elemental Hg, TeH2, and Cd(CH3)2. Their relative concentrations are monitored as ion and neutral fluxes (both in intensity and composition), ion energy and substrate temperature are varied. General insights are made into surface chemistry mechanisms of the etch process. These insights are evaluated by examining etch anisotropy and damage to the remaining semiconductor material. Regions of process parameter space best suited to moderate rate, anisotropic, low damage etching of HgCdTe are identified.
The relative importance of large mammal species for tourism in Amboseli National Park, Kenya

Abstract Marketing for tourism in Kenya mostly revolves around “the big five” charismatic large mammals. However, it is not known if these are in fact the species tourists seek and prefer to see, or what other species are important when the “big five” are absent. This study investigated the large mammal interests of tourists in Amboseli National Park. Tourist interests were determined by tracking tourist vehicles and observing for which animals they stopped, the duration of each stop, and which animals were ignored. We developed five criteria for assessing the relative importance of large mammals: (i) length of viewing, (ii) vehicle crowding, (iii) stopping on every encounter, (iv) proportion of stops per species, and (v) the relative tourism importance rank index that weighed viewing to availability. This study found that tourists were interested particularly in the big cats and other unique large mammals, but interest was not confined to these species. Other animals attracting interest were cheetah, waterbuck, lion, hippopotamus, giraffe, spotted hyena, baboon, warthog and elephant. We propose that marketing for Amboseli should focus on the large mammals that tourists actually prefer and highlight the viewing potential of these mammals within the park. This should also be emulated such that each protected area in Kenya develops its own list of “attractive” animals for tourists.
Routes: Travel and Translation In the Late Twentieth Century

Routes: Travel and Translation In the Late Twentieth Century. James Clifford. Cambridge, MA: Harvard University Press, 1997. 408 pp., figures, notes, references, sources, Index.
Elliptical boundary arrays for coherent and incoherent imaging

In the imaging of far-field source distributions by a planar array of antenna elements, the quality of the image is determined by the beam pattern of the array. The physical size of the aperture ultimately determines its resolution capability, and the excitation or weighting imparted to the aperture controls the sidelobe characteristics. For a given number and spacing of antenna elements, the largest physical apertures are formed if the elements are distributed only around the boundaries of the apertures. This, however, results in beam patterns with rather high sidelobes. Thus it is of clear practical advantage to have available a technique for effectively filling in the interior of such a boundary aperture through appropriate signal processing applied to the boundary element signals. The paper builds on early results concerning such a technique, which made use of incoherent (receive-only) imaging systems. It is shown that for both incoherent imaging, the latter implemented using a transmit/receive scheme, it is possible to obtain such a filling-in or interpolation effect when imaging with an array composed of an elliptical (or circular) arrangement of array elements. Explicit synthesis theorems which give a specific constructive approach to implementing this effective interpolation to any desired degree of accuracy are given, and this approach is illustrated by giving the results of simulations, both with and without element location errors.
Efficient Forward Error Correction Coding for Free-Space Optical Communications

Atmospheric turbulence is known as the major channel impairment for outdoor long-distance free space optical communication. This paper investigates the performance of high-rate fast-speed Reed-Solomon (RS) codes on log-normal fading FSOC channels. The cases where the channel state information is available and unavailable to the decoder are investigated. The impacts of turbulence strength, temporal correlation, interleaver type and size, as well as performance comparison to turbo codes are reported. Through theoretical analysis and extensive computer simulations, it is shown that impressive coding gain can be achieved for RS codes with very little overhead.
Titian's Portrait of Filippo Archinto in the Johnson Collection

In the John G. Johnson Collection in Philadelphia there is a painting which never fails to excite the interest of visitors to the gallery (Fig. 1). It is a portrait of the sixteenth century Milanese prelate Filippo Archinto, which has long been attributed to Titian. With its mysterious veil, this painting would be unique in the work of Titian, and perhaps in the whole history of art. Another portrait of the same prelate, without a veil, hangs in the Altman Gallery of the Metropolitan Museum (Fig. 2), and it is so much like the painting in the Johnson Collection that one must be a copy of the other. We are thus confronted with an interesting problem of attribution as well as a fascinating iconographical riddle.
Rurality and cancer surgery in the United States

Abstract Background Rurality adversely impacts the continuum of cancer care. However, investigations of rural cancer surgery are notably absent. We examined patterns and outcomes of oncologic resections at rural US hospitals. Methods We identified 928,370 hospital admissions in which 1 of 20 oncologic resections was performed using the 1998 to 2009 Nationwide Inpatient Sample. Logistic regression examined predictors of rurality and the adjusted likelihood of in-hospital mortality at rural and urban hospitals. Results The fraction of procedures performed at rural hospitals decreased from 12% to 6%. Older age, non-Hispanic white race, and fewer comorbidities predicted rurality. Rural hospitals did not have worse mortality, however, rurality significantly augmented mortality among recipients of complex cancer surgery. Conclusions Rural hospitals had comparable mortality overall, but delivered poorer outcomes for certain groups. Future research should explore these variations as cancer care is increasingly centralized.
Consequences of individual feedback on behavior in organizations.

The literature on feedback to individuals was reviewed with respect to its effect on the behavior of individuals in performance-o riented organizations. Although contemporary views of individual behavior in organizations stress that feedback is necessary for effective role performance, little attention is given to the psychological processes affected by it. This review focuses upon the multidimensional nature of feedback as a stimulus and addresses the process by which feedback influences behavior. Emphasis is placed on those aspects of feedback that influence (a) the way it is perceived, (b) its acceptance by the recipient, and (c) the willingness of the recipient to respond to the feedback. Feedback about the effectiveness of an individual's behavior has long been recognized as essential for learning and for motivation in performance-oriented organizations. Not surprisingly, considerable research has been conducted on the subject (see reviews of feedback by Adams, 1968; Ammons, 19S6; Annett, 1969; Bilodeau, 1966; Locke, Cartledge, & Koeppel, 1968; Sassenrath, 1975). Yet, in spite of the large and varied literature, generalizations about the effects of feedback on individuals are few. Several factors contribute to this state of affairs. First, feedback is not a simple stimulus. The diverse elements subsumed under the single rubric of feedback may share the property of conveying some degree of information about past behavior, but they share We wish to thank L. L. Cummings, H. P. Dachler, E. A. Locke, M. M. Greller, D. M. Herold, and J. C. Naylor for their helpful comments on an earlier draft of this article. The research was supported by Grant DAHC 19-76-G-0017 from the Army Research Institute for the Behavioral Sciences, as part of the technical-base research project for the Organizational Development Unit. While the support of the agency is greatly appreciated, the ideas expressed in the article are solely those of the authors and are not to be considered the position of the agency or the U.S.