cssi/SciSciGPT-SciSciNet huggingface dataset:
Treatment Options for Refractory Angina Pectoris: Enhanced External Counterpulsation Therapy

Refractory angina pectoris, defined as angina refractory to maximal medical therapy and standard coronary revascularization procedures, remains a significant health problem in the United States and the world. Despite a panoply of recent therapeutic advances, patients with refractory angina pectoris are not adequately treated; therefore, scientists have been investigating new technologies to help these patients. The technique of counterpulsation, studied for almost half a century, is considered a safe, highly beneficial, low-cost, noninvasive treatment for these angina patients and now also for those with heart failure. Recent evidence suggests that enhanced external counterpulsation (EECP) therapy may improve symptoms and decrease long-term morbidity via several mechanisms, including improvement in endothelial function, promotion of collateralization, enhancement of ventricular function, improvement in oxygen consumption (Vo(2)), regression of atherosclerosis, and peripheral "training effects" similar to exercise. Numerous clinical trials in the past two decades have shown EECP therapy to be safe and effective for patients with refractory angina, with a clinical response rate averaging 70% to 80%, which is sustained up to 5 years. This review summarizes the current evidence to support EECP's use in treating refractory angina pectoris.
A comparison of CF4 + hydrocarbon fast gases for drift chambers and straw tubes

Measurements have been made of the signal charge, drift time distributions and sensitivity to soft photons and charged particles, for several CF4 + hydrocarbon fast gas mixtures. Comparisons are made with Ar + C2H6 (50:50) and with other standard gases. CF4 + CH4 (30:70) is found to have many advantages over CF4 + iC4H10 (80:20), which may make it appropriate for use in high rate particle physics experiments.
Cerebral correlates of amygdala responses during non-conscious perception of facial affect in adolescent and pre-adolescent children

During nonconscious perception of facial affect, healthy adults commonly activate a right-lateralized pathway comprising the superior colliculus, pulvinar, and amygdala. Whether this system is fully developed prior to adulthood is unknown. Twenty-three healthy adolescents underwent functional magnetic resonance imaging (fMRI) while viewing fearful, angry, and happy faces, backward masked by neutral faces. Left amygdala activation differed among the three affects, showing reductions to masked anger and increases to masked fear and happy faces. During masked fear, left amygdala activation correlated positively with extrastriate cortex and temporal poles and negatively with precuneus and middle cingulate gyrus. Responses of the left amygdala to masked anger correlated positively with right parahippocampal gyrus and negatively with dorsal anterior cingulate. Amygdala responses to masked happy faces were uncorrelated with other brain regions. Contrary to the right-lateralized pathway seen in adults, adolescent...
Effects of Changing Density and Food Level on Metamorphosis of a Desert Amphibian, Scaphiopus Couchii

Amphibians that breed in temporary ponds provide a good opportunity to study the ecological and evolutionary consequences of environmental variability. Ephem- eral aquatic habitats provide larval amphibians a transient and highly variable opportunity for growth. In the desert ponds used by Couch's spadefoot toad (Scaphiopus couchii), tadpole density varies considerably among ponds and often increases within a pond as it dries. Models of optimal size and timing of metamorphosis predict that, relative to constant high resource environments, metamorphosis should occur at a smaller size in constant low resource environments, and smaller and earlier in declining resource environments, as- suming all else is equal. Considerable evidence supports the first prediction, but few studies have examined the effect of decreasing resource availability. I conducted an experiment to examine the effects of increasing density and decreasing food level on metamorphosis in Couch's spadefoot toads. Tadpoles at constant high per capita food metamorphosed at the largest sizes. At low or decreasing per capita food, tadpoles metamorphosed at a uniformly small size, but varied in the time required to reach that size. Tadpoles from both increasing density and decreasing food treatments metamorphosed earlier than tadpoles from constant density, constant food treatments. These results support the idea that tadpoles can respond adaptively to resource variation.
Eye lens regeneration and the crystallins in the adult newt, Notophthalmus viridescens

Upon lens removal, the adult Eastern Spotted newt, Notophthalmus viridescens, has the capacity to regenerate an ocular lens. Crystallins, proteins characteristic of the vertebrate lens, were studied from normal and 3-month regenerated adult newt lenses. When separated by high-performance liquid chromatography (HPLC) or Sephadex G-200SF column chromatography, the crystallins from normal and regenerated lenses were fractionated into what appear to be the classical four groups: alpha, beta High, beta Low, and gamma. Upon further examination by immunoelectrophoresis, the first peak contains both alpha and beta crystallins. This study provides evidence that most of the crystallins from the regenerated lenses share biochemical properties with those of the normal lens crystallins based on their native molecular weight, isoelectric point, and the molecular wt of their constituent polypeptides, indicating that the fidelity of gene expression in reactivated iris tissue is high. Some differences are found between normal and regenerated lens crystallins and are most obvious in the beta-crystallin region: the proportion of beta crystallins is decreased in regenerated lenses when the total proteins are fractionated by column chromatography and some of the beta-crystallin polypeptide chains found in normal lenses are missing from regenerated lenses. Iris epithelial cells are normally withdrawn from the cell cycle and are synthesizing a tissue-specific product, melanin. After lentectomy these cells dedifferentiate, redifferentiate into lens cells, and their progeny then synthesize different tissue-specific proteins, crystallins. Little is known about the specific mechanism(s) for the activation of gene expression in eukaryotes, but the regenerating lens suggests itself as a good model in which to study this biological problem.
Optically active diethyl N-(p-toluenesulfonyl)-aziridine 2-phosphonates as chiral synthons for the synthesis of β-substituted α-amino phosphonates

A versatile approach for the synthesis of both protected enantiomers of aziridine 2-phosphonates for use as chiral synthons has been developed. The aziridines arise from either (R)- or (S)-phosphonoserine diethyl esters followed by N-tosylation, O-mesylation and cyclization with sodium hydride. These highly enantio-enriched aziridine 2-phosphonates have been shown to react with carbon, nitrogen, sulfur, hydride, fluoride, and phosphorus nucleophiles allowing for the rapid production of a variety of β-substituted α-amino phosphonates in either the (R)- or (S)-configurations. In the case of thiol nucleophiles, use of a stoichiometric amount of tri-n-butylphosphine was necessary to cleanly produce the corresponding sulfide products. Chiral HPLC methods were utilized to monitor the synthetic processes to evaluate the enantiomeric excess of the products obtained when possible.
Proton NMR Determination of Miscibility in a Bulk Model Photoresist System: Poly(4-hydroxystyrene) and the Photoacid Generator, Di(tert-butylphenyl)Iodonium Perfluorooctanesulfonate

The intimacy of component mixing in solvent-cast blends of poly(4-hydroxystyrene) (PHS) and a photoacid generator (PAG), di(tert-butylphenyl)iodonium perfluorooctanesulfonate (PFOS) were studied by solid-state proton NMR. These are simplified blends for chemically amplified photoresist formulations used in the micro-electronics industry. Multiple-pulse NMR techniques are used in both spin-diffusion and longitudinal relaxation experiments at ambient temperatures. It is deduced that PFOS is mixed with PHS on a molecular scale for the mass-ratio range investigated, namely, 91/9 to 55/45 PHS/PFOS; hence, the two components are thermodynamically miscible in this range. Control experiments involving a 91/9 physical mixture of PHS and PFOS as well as solvent-cast blends of polystyrene (PS) and PFOS serve to illustrate the contrast between data obtained for phase-separated blends and data for blends that display molecular level mixing. An attempt was also made to support the notion of intimate PFOS/PHS mixing by ...
Cell recognition among blood leukocytes: a new theory for cell recognition.

Blood leukocytes exhibit specific cell type recognition. Neutrophils adhere to neutrophils, eosinophils to eosinophils, basophils to basophils and monocytes to monocytes. Rather large homotypic aggragates are formed. These are almost abolished by prior treatment of the cells with trypsin. It is assumed that a protein is involved in this type of cell recognition. protein monomer-monomer interaction could provide the specificity required in homotypic aggregate formation.
THE LOGISTICS OF AIR CARGO CO-MINGLING AT TED STEVENS ANCHORAGE INTERNATIONAL AIRPORT

Abstract This paper discusses the current efforts to bring further deregulation to international air cargo operations. This is done in the context of a special set of operations, known as co-mingling, which is allowed at Ted Stevens Anchorage International Airport. Co-mingling involves air cargo being transferred to another airplane that may or may not be in the initiating carrier's fleet. After the transfer is completed the cargo proceeds based on the second plane's pre-determined routing. This paper sets co-mingling in context with co-terminalization and cabotage operations by outlining the limitations of what the United States Department of Transportation actually mandated. While the operations are unique to the State of Alaska they do set a precedent for unilateral reform of international air cargo operations on the part of the US government. An economic appraisal of co-mingling operations is provided and is shown to be a source of efficiency gains for the US air cargo market.
Peptide Sequence and Conformation Strongly Influence Tryptophan Fluorescence

This article probes the denatured state ensemble of ribonuclease Sa (RNase Sa) using fluorescence. To interpret the results obtained with RNase Sa, it is essential that we gain a better understanding of the fluorescence properties of tryptophan (Trp) in peptides. We describe studies of N-acetyl-L-tryptophanamide (NATA), a tripeptide: AWA, and six pentapeptides: AAWAA, WVSGT, GYWHE, HEWTV, EAWQE, and DYWTG. The latter five peptides have the same sequence as those surrounding the Trp residues studied in RNase Sa. The fluorescence emission spectra, the fluorescence lifetimes, and the fluorescence quenching by acrylamide and iodide were measured in concentrated solutions of urea and guanidine hydrochloride. Excited-state electron transfer from the indole ring of Trp to the carbonyl groups of peptide bonds is thought to be the most important mechanism for intramolecular quenching of Trp fluorescence. We find the maximum fluorescence intensities vary from 49,000 for NATA with two carbonyls, to 24,400 for AWA with four carbonyls, to 28,500 for AAWAA with six carbonyls. This suggests that the four carbonyls of AWA are better able to quench Trp fluorescence than the six carbonyls of AAWAA, and this must reflect a difference in the conformations of the peptides. For the pentapeptides, EAWQE has a fluorescence intensity that is more than 50% greater than DYWTG, showing that the amino acid sequence influences the fluorescence intensity either directly through side-chain quenching and/or indirectly through an influence on the conformational ensemble of the peptides. Our results show that peptides are generally better models for the Trp residues in proteins than NATA. Finally, our results emphasize that we have much to learn about Trp fluorescence even in simple compounds.
Delay in fatigue crack growth

The importance of delay, or retardation in the rate of fatigue crack growth, produced by load interactions in variable amplitude loading on the accurate prediction of fatigue lives of engineering structures has been well recognized for some time. Heretofore, only a few simple loading combinations or spectra have been examined systematically. In this investigation the effects of a broad range of loading variables on delay in fatigue crack growth at room temperature are examined for a mill annealed Ti-6Al-4V alloy. The results are used to estimate crack growth behavior under programmed loads.
Differential expression and 5′ end mapping of actin genes in Dictyostelium

Abstract Using a modification of the Berk and Sharp S1 nuclease mapping procedure and by analyzing actin cDNA clones, we have examined the expression of several members of the 17-member multigene family encoding actin in Dictyostelium. The mapping procedure, which takes advantage of the fact that the actin genes are homologous in the protein-coding region but are very divergent in the proposed 5′ untranslated region has enabled us to quantitate the relative expression of several genes during the Dictyostelium life cycle. We have shown that at least six of the 17 potential actin-coding sequences are expressed. One is not expressed at levels of more than 0.5-1% of total actin mRNA at the developmental times examined and appears to be a pseudogene. By quantitating the amount of actin mRNA in mRNA populations isolated from cells at various times in development, we have shown that four of the actin genes show different patterns of expression. Interestingly, three of the four genes appear to encode the same protein. We have also taken advantage of the S1 mapping procedure to identify the 5′ ends of the actin mRNAs from four genes and have compared the sequences outside the 5′ ends on these genes with the nucleotide sequences of seven other actin genes. We have identified homologous sequences in most of these genes that may be involved in initiation of transcription.
A simplified purification method for the analysis of abscisic acid

A fast and convenient method is given for the purification of abscisic acid (ABA) in plant extracts. Using a dual pH elution system on Sep-Pak C18 reverse phase prepacked cartridges, abscisic acid appears in the third eluent (32% methanol pH 8.0). The cartridges can be regenerated for multiple reuse.
Understanding and engineering RNA sequence specificity of PUF proteins

PUF proteins are RNA-binding proteins named for founding members PUMILIO and fem-3 binding factor (FBF). Together these proteins represent the range of known RNA recognition properties. PUMILIO is a prototypical PUF protein whose RNA sequence specificity is simple, elegant, and predictable. FBF displays differences in RNA recognition that represent divergence from the prototype. Here we review recent studies that examine the engineering of sequence specificity of PUF proteins and its applications as well as studies that increase our understanding of the natural diversity of RNA recognition by this family of proteins.
A SIMPLIFIED ASSESSMENT OF GESTATIONAL AGE

Accurate gestational assessment is important for the appropriate management of every newborn infant. There is still a need for a simple yet reliable method which could be used by ancillary personnel as well as physicians. A score was developed by condensing the methods of Dubowitz and others. The new score consists of 6 neurologic and 6 physical criteria (see Klaus and Fanaroff: CARE OF THE HIGH RISK NEONATE p. 47, W.B.Saunders,1973). To obtain this, multiple physical criteria were combined into single observations and neurologic signs using active muscle tone (which are misleading in sick infants) were eliminated. To test the accuracy of the simplified system, the Dubowitz method was used as a standard, and 284 babies were examined by both methods by unbiased observers. Ages ranged from 12 to 96 hrs with weights ranging from 760 to 5460 gms. Correlation between the two examinations was 0.975, p<.001). Individual criteria of the simplified score on a second group of 86 infants were then weighted for predictive value according to their correlation with known dates. The gestational age tended to be more closely related to the individual components of the physical assessment (r=0.614-0.784) than to the neurologic criteria (r-0.437-0.756). The correlation for the score obtained for the total assessment (r=0.952) was greater than that for any of the individual components. The average time required for Dubowitz exam was 10-15 min, the simplified method 3-4 min. This simplified scoring system provides a rapid and accurate assessment of gestational age.
Breast tumor vascularity identified by contrast enhanced ultrasound and pathology: initial results

Quantifiable measures of vascularity obtained from contrast enhanced color flow images were correlated with pathologic vascularity measurements in ten female patients with a solid breast mass. Each patient received Levovist Injection (Berlex Laboratories Inc., Montville, NJ). Color flow images pre- and post-contrast were obtained using an HDI 3000 unit (ATL, Bothell, WA) before removing the mass for pathologic vascularity assessments. Image-processing techniques were used to obtain both the ultrasound and pathologic vascularity measurements. Multiple linear regression found significant correlations for ultrasonic vascularity measurements post contrast and pathology (P = 0.02 and 0.06). No correlations were found between pre-contrast ultrasound and pathology. In conclusion, post-contrast ultrasonic flow measures provide a non-invasive measure of breast tumor neovascularity. However, the patient population is small, and until further patients are analyzed, these conclusions are preliminary.
Ion-atom collision-induced absorption.

We examine the linear electrodynamics arising from ion–atom collision-induced absorption. For this situation, induced absorption is achieved by means of long-range electrostatic forces, and the resulting spectral lines are relatively intense, symmetrical, and narrow. As a specific application, we examine the 3P0 → 1S0 forbidden transition of Sn, which is induced to absorb by collisions with I−. The resultant lines are of the order of 15 cm−1 wide, and the collision-induced absorption coefficienty is 0.45%/cm per Torr of Sn and per 0.1 Torr of I−.
Prostaglandin production by type II alveolar epithelial cells

Prostaglandin production was studied in fetal and adult type II alveolar epithelial cells. Two culture systems were employed, fetal rat lung organotypic cultures consisting of fetal type II cells and monolayer cultures of adult lung type II cells. Dexamethasone, thyroxine, prolactin and insulin, hormones which influence lung development, each reduced the production of prostaglandin E and F alpha by the organotypic cultures. The fetal cultures produced relatively large quantities of prostaglandin E and F alpha and smaller quantities of 6-keto-prostaglandin F1 alpha and thromboxane B2. However, prostaglandin E2 production was predominant. In contrast, the adult type II cells in monolayer culture produced predominantly prostacyclin (6-keto-prostaglandin F1 alpha) along with smaller quantities of prostaglandin E2 and F2 alpha. The type II cells were relatively unresponsive to prostaglandins. Exogenously added prostaglandin E, had no effect on cell growth, and only a minimal effect on cyclic AMP levels in the monolayer cultures.
Testing for Spatial Autocorrelation in Ecological Studies

We describe a statistical method appropriate for the analysis of spatial autocorrelation in data varying in time as well as space. In particular, the technique was developed lo address the issue of geographic synchrony in ecological variables that may change markedly from year to year such as population density of animals or seed production of trees. The method yields ‘modified correlograms” that test for significant autocorrelation between sites located within any given range of distances apart. This technique facilitates detecting and understanding spatial processes m a variety of ecological phenomena, including testing the plausibility of causational hypotheses using cross-correlational analyses. Several examples are discussed, including population densities of squirrels in Finland, winter densities of two hawk species in California, and acorn production and radial growth by individual blue oak Quercus douglasii trees in central coastal California.
Textured titanium oxide thin films produced by vacuum arc deposition

Abstract Results of vacuum arc deposition of titanium oxide at room temperature on silicon (100) and (111), with and without applying high voltage pulses of up to 10 kV to the substrate, are presented in this report. A titanium cathode in oxygen atmosphere was used to produce the titanium and oxygen ions. Rutile, the high temperature modification of the TiO2 phase, was found with some minor additions of substoichiometric oxides like Ti4O7 using X-ray diffraction (XRD). Columnar growth of strongly textured rutile was observed at all pulse bias voltages. The epitaxial relation is [110]TiO2‖[111]Si and [110]TiO2‖[311]Si. The rutile orientation is facilitated by a rather small lattice misfit of 3.4% for the Si[111] direction and 0.86% for the Si[311] direction. While applying a negative d.c. bias or high voltage pulses to the substrate, only a gradual loss of texture was observed, so that at 10-kV pulses, oriented rutile was still observed.
Editorials in national development: Perceptions of Nigerian journalists

Abstract This study examines the self‐reported perceptions of the role of editorials in national development for a purposive sample of 348 full‐time, salaried Nigerian journalists on nine national newspapers in two newspaper ownership groups: private and government. Three major findings are indicated. The first finding is that, on seven‐statement comparisons of the role of editorials in national development, government journalists perceived their editorials as more supportive of the government than did private journalists, a result largely reflective of government newspapers’ persuasive role in behalf of government agencies. The second finding is that ownership of newspapers is not a particularly strong factor in journalists’ perceptions of the role of editorials in development. Such a finding calls into question the rationale for the continuing case for private ownership of Africa's media institutions as a solution to the limitations of the region's media in exercising independent, effective, and persuas...
Esterification of Lactic Acid and Ethanol with/without Pervaporation

Reactors coupled with membrane separation, such as pervaporation, can help enhance the conversion of reactants for thermodynamically or kinetically limited reactions via selective removal of one or more product species from the reaction mixture. An example of these reactions is esterification of carboxylic acids and alcohols. Esterification of lactic acid (C3H6O3) and ethanol (C2H5OH) is studied in well-mixed reactors with/without a solid catalyst (Amberlyst XN-1010) in this paper. Rate expressions for homogeneous and heterogeneous esterification are obtained from the experimental data using differential and integral methods. Experiments with a closed-loop system of a “batch” catalytic reactor and a pervaporation unit reveal that fractional conversions of the two reactants and yield of ethyl lactate exceeding the corresponding maximum values in a reaction-only operation are obtained by stripping of the byproduct (water). The efficacy of pervaporation-aided esterification is illustrated by the substantial ...
Effects of conformational stability and geometry of guanidinium display on cell entry by β-peptides

We have used our ability to control beta-peptide secondary structure in order to explore the effects of conformational stability and geometry of guanidinium display on cell entry. Both of these factors affect the rate and relative amount of beta-peptide accumulation in the cytoplasm and nucleus of live HeLa cells. These beta-peptides do not show significant differences in cell surface binding, implying that structure and guanidinium display are important in a later step in cell entry than initial surface binding.
Bisphosphonate Actions on Cancer

Bisphosphonates (BPs) suppress cancer cell colonization in bone associated with cancers such as breast cancer and multiple myeloma. The mechanism of the suppressive action of BPs is thought to be due to an inhibition of osteoclastic bone resorption which releases bone-stored growth factors that feed cancer cells colonizing bone. Recently, data are accumulating that BP suppresses growth and induces apoptosis in cancer cells in culture, suggesting that BP directly influences survival of cancer cells in an osteoclast-independent manner. These results raise the possibility that BP inhibits cancer growth in organs other than bone. However, evidence is limited that BP reduces tumor growth in non-bone sites in cancer patients. In this review, we discuss the effectiveness of BP on breast cancer colonization in non-bone sites and our results in animal models with metastases. With currently available clinical and in vivo experimental data, BPs are definitely beneficial for the treatment of cancer patients who manifest clinically detectable bone metastases. However, it is not recommended that BP be given as a preventative to patients with visceral metastases and of no evidence of bone metastases. Whether individual BP with different chemical structure has unique biological or biochemical action is an intriguing question but open at the moment.
Long‐term survival of patients with acute differentiated histocytosis (letterersiwe disease)

A case is reported in which a patient with the typical clinical and pathologic features of Letterer-Siwe disease survived more than 15 years from the onset of symptoms. A search of the literature revealed only four other instances of similarly long survivals. An attempt to correlate clinical features and treatment data with length of survival in 96 adequately documented cases collected from the literature showed few clear-cut trends. Lack of pulmonary involvement and the absence of thrombocytopenia seem to be of favorable prognostic significance. Of the patients 18.9% survived 2 years or longer; all but one of these were still alive at the time of the last follow-up. Survivals of 2 years or longer were significantly higher in patients who had received corticosteroids than in those who had not. The number of reported long-term survivals is too small to permit one to detect a common denominator that would make it possible to predict such a favorable clinical course.
Role-Making in Participant Observation: Processes in the Researcher-Actor Relationship

Although recent essays about participant observations have extended our understanding of that research method and its problematic aspects, few methodologists have scrutinized intensively the processes by which roles are developed in this type of fieldwork or the relationship of role development to the data gathered. Our purpose in reviewing our own experiences as participant observers in a longitudinal study of baccalaureate student nurses is to explore these questions. We have also studied reports of the encounters of other researchers in participant observation. Using information from such experiences, we have tried to outline and interpret the characteristic processes of role defining in this type of research. We have restricted ourselves to consideration of fieldwork situations in which the involved parties are mutually aware of the research, thus avoiding the special problems of role definitions in hidden research.
Regression Calibration for Dichotomized Mismeasured Predictors

Epidemiologic research focuses on estimating exposure-disease associations. In some applications the exposure may be dichotomized, for instance when threshold levels of the exposure are of primary public health interest (e.g., consuming 5 or more fruits and vegetables per day may reduce cancer risk). Errors in exposure variables are known to yield biased regression coefficients in exposure-disease models. Methods for bias-correction with continuous mismeasured exposures have been extensively discussed, and are often based on validation substudies, where the “true” and imprecise exposures are observed on a small subsample. In this paper, we focus on biases associated with dichotomization of a mismeasured continuous exposure. The amount of bias, in relation to measurement error in the imprecise continuous predictor, and choice of dichotomization cut point are discussed. Measurement error correction via regression calibration is developed for this scenario, and compared to naily using the dichotomized mismeasured predictor in linear exposure-disease models. Properties of the measurement error correction method (i.e., bias, mean-squared error) are assessed via simulations.
Detection of adeno-associated virus (AAV)-specific nucleotide sequences in DNA isolated from latently infected Detroit 6 cells

Abstract Detroit 6 cells exposed to 250 TCID 50 /cell of adeno-associated virus (AAV)-2 retained the ability to produce AAV antigens and infectious virus upon subsequent exposure to helper adenovirus type 2 for many passages. The increased rate of annealing of 32 P-labeled AAV-DNA in the presence of cellular DNA from two such latently infected clones indicated the presence of three to five AAV genome equivalents per diploid amount of cell DNA.
Cocaine actions in a central noradrenergic circuit: enhancement of cerebellar Purkinje neuron responses to iontophoretically applied GABA.

Abstract Many recent studies have implicated the mesolimbic dopaminergic pathway as the central neurotransmitter system which is most likely responsible for the euphoria and abuse potential associated with cocaine self-administration. Nevertheless, cocaine also has well established interactions with the norepinephrine- and serotonin-containing pathways of the brain. In order to begin assessing potential nondopamine-mediated actions of cocaine in central circuits, we have initiated a series of experiments using the cerebellar Purkinje neuron as an electrophysiological test system. The strategy was to use the same experimental protocols employed in previous investigations of noradrenergic influences on putative amino acid transmitter action to examine the effects of exogenously applied cocaine on γ-aminobutyric acid (GABA)-induced depressant responses of Purkinje cells. Accordingly, the inhibitory responses of Purkinje neurons to microiontophoretically applied GABA were examined before and after systemic or local iontophoretic administration of cocaine. Drug-induced changes in the spontaneous firing rate and GABA responsiveness of individual cells were assessed by quantitative analysis of perievent histograms. The results indicate that, like norepinephrine, cocaine at parenteral or iontophoretic doses subthreshold for producing direct suppression of spontaneous discharge can augment Purkinje neuron responses to GABA. Such potentiating effects of cocaine on GABA-mediated inhibition were not evident in animals pretreated with the selective noradrenergic toxin DSP-4. These findings indicate that cocaine can enhance central neuronal responsiveness to GABA in a manner identical to that shown previously for norepinephrine. Such actions in noradrenergic target circuits throughout the brain could contribute to the net behavioral response observed following cocaine administration.
Naphthalene mineralization coupled to sulfate reduction in aquifer-derived enrichments

Naphthalene was microbially transformed in sulfate-reducing laboratory microcosms established under strictly anaerobic conditions using sediment from two sulfate-rich, coal tar-contaminated aquifers and enriched over a 3-year period. As much as 66% of [14C]naphthalene was mineralized to CO2 over 13 days. Addition of sodium molybdate inhibited sulfidogenesis and resulted in a 44% reduction in total [14C]naphthalene mineralized. Methane was never detected in active naphthalene-degrading microcosms, and formation of sulfide during naphthalene degradation was confirmed using a 35SO2−4 radiotracer technique. GC/MS analyses of stabilized naphthalene-degrading consortia indicated the formation of naphthalenol as a potential metabolic intermediate. These results demonstrate that naphthalene oxidation may be coupled to sulfate reduction in aquifer-derived sediments.
A Hybrid Architecture for Maneuver-Based Motion Planning and Control of Agile Vehicles

Abstract The paper presents an integrated approach for motion planning and control of nonlinear systems in obstacle environments. To reduce online computation time, dynamically-feasible trajectories will be generated in real-time from a library of pre-specified maneuvers, with the sequence of maneuvers to be traversed determined by a heuristic search algorithm which incorporates some features of greedy search along with effective backtracking. Linearizing the nonlinear system equations about the library maneuvers results in a hybrid linear time-varying model. The paper provides an optimal control algorithm, with the l2-induced norm as the performance measure, for such a hybrid model, which ensures that the system tracks the desired trajectory as accurately as possible despite various disturbances and uncertainties. The paper also compares the performance of the developed motion planning algorithm to that of dynamically weighted A*.
A role for cortactin in Listeria monocytogenes invasion of NIH 3T3 cells, but not in its intracellular motility.

Cortactin is an F-actin binding protein that binds to the Arp2/3 complex, stimulates its actin nucleation activity, and inhibits actin filament debranching. Using RNA interference directed against cortactin, we explored the importance of cortactin for several processes involving dynamic actin assembly. Silencing cortactin expression was efficiently achieved in HeLa and NIH 3T3 cells, with less than 5% of cortactin expression in siRNA-treated cells. Surprisingly, endocytosis in HeLa and NIH 3T3 cells, and cell migration rates, were not altered by RNAi-mediated cortactin silencing. Listeria utilizes actin-based motility to move within and spread among mammalian host cells; its actin-clouds and tails recruit cortactin. We explored the role of cortactin during the Listeria life cycle in cortactin “knockdown” NIH 3T3 cells. Interestingly, cortactin siRNA-treated cells showed a significant reduction in the efficiency of the bacteria invasion in NIH 3T3 cells. However, cortactin depletion did not interfere with assembly of Listeria actin clouds or actin tails, or Listeria intracellular motility or speed. Therefore, our findings suggest that cortactin plays a role in Listeria internalization, but not in the formation of actin clouds and tails, or in bacteria intracellular motility. Cell Motil. Cytoskeleton 2006. © 2006 Wiley-Liss, Inc.
Real time spectroscopic ellipsometry of Ag/ZnO and Al/ZnO interfaces for back-reflectors in thin film Si:H photovoltaics

Abstract Real time spectroscopic ellipsometry (RTSE) has been applied to analyze the optical characteristics of Ag/ZnO and Al/ZnO interfaces used in back-reflector (BR) structures for thin film silicon photovoltaics. The structures explored here are relevant to the substrate/BR/Si:H(n-i-p) solar cell configuration and consist of opaque Ag or Al films having controllable thicknesses of microscopic surface roughness, followed by a ZnO layer up to ~ 3000 A thick. The thicknesses of the final surface roughness layers on both Ag and Al have been varied by adjusting magnetron sputtering conditions in order to study the effects of metal film roughness on interface formation and interface optical properties. The primary interface loss mechanisms in reflection are found to be dissipation via absorption through localized plasmon modes for Ag/ZnO and through intraband and interband transitions intrinsic to metallic Al for Al/ZnO.
Feeding rate and the structure of protein digestion and absorption in lepidopteran midguts

The transformation of leaf protein into insect tissue can be distilled grossly into four serial steps: consumption of protein, digestion of protein into small peptides and free amino acids, absorption of these fragments across the gut epithelium, and construction of tissue from the absorbed fragments. We examine these steps in caterpillars, with emphasis on determining which, if any, process is limiting and how digestive events influence—and are influenced by—the rate of consumption. Five competing hypotheses are (1) the steps are matched, (2) consumption is limiting, (3) digestion is limiting, (4) absorption is limiting, and (5) post-absorptive processes are limiting. For conditions appropriate to each of the five hypotheses, we use a chemical reactor model to predict the concentration profiles of protein and protein breakdown products along the midgut. We test the predictions in two ways. First, based on midgut morphology and rates of digesta flow and protein breakdown estimated from in vitro experiments, we calculate the axial concentration profile of protein in the midgut of fifth instar Manduca sexta. This calculation suggests that protein breakdown occurs primarily in the anterior midgut, thus excluding the hypotheses that feeding and digestive processes are matched or that digestion is limiting. In addition, caterpillar feeding responses to reduced concentrations of protein are not consistent with the hypothesis that consumption is limiting. Second, we review published studies that show midgut concentration profiles of protein and breakdown products, one supporting the hypothesis that absorption across the midgut epithelium is limiting and the other suggesting that post-absorptive processes are limiting. Consequently, we interpret compensatory feeding by larval M. sexta as a mechanism for maintaining saturated rates of protein absorption or of tissue construction. Arch. Insect Biochem. Physiol. 42:74–87, 1999. © 1999 Wiley-Liss, Inc.
Retrospective analysis of preoperative embolization of spinal tumors.

BACKGROUND AND PURPOSE: Preoperative embolization of primary and metastatic spinal tumors is often performed to decrease intraoperative blood loss and facilitate surgical resection. The purpose of this study was to evaluate the safety of spinal tumor embolization and the variables that may influence intraoperative blood loss. MATERIALS AND METHODS: A retrospective analysis of 100 spinal tumor embolization procedures was performed. Multiple variables were evaluated with respect to intraoperative blood loss, including tumor pathology, degree of tumor embolization, embolization above/below the levels involved, PVA particle size, surgical approach, and invasiveness. RESULTS: There was 1 significant complication of the 100 embolization procedures performed. Evaluation of the entire set of embolization procedures demonstrated that RCC was associated with increased intraoperative blood loss (P = .009) relative to other tumor types, as were the surgical approach and invasiveness of the surgery performed. No other variables were found to be statistically significant predictors of intraoperative blood loss. Subset analysis of all RCCs demonstrated that complete embolization resulted in decreased blood loss compared with partial embolization (P = .03) and that male sex was associated with increased blood loss (P = .029). CONCLUSIONS: Preoperative embolization of spinal tumors is a safe procedure. Complete embolization of RCCs results in lower intraoperative blood loss compared with partial embolization. The effectiveness of preoperative embolization of non-RCCs is unclear. Using smaller embolic particles and embolizing beyond the levels affected by tumor may not provide added benefit.
Use of Dynamic Cone Penetrometer to Control Compaction of Granular Fill

Granular material is commonly used as backfill and embedment material for buried structures, including thermoplastic pipe. Proper compaction of this material is crucial to the successful performance of the pipe. However, the commonly used Proctor density approach cannot be used for the field compaction control of these materials because it does not provide a well-defined moisture-density relationship. An alternative method used by the authors for compaction control of such materials is described. This method involves a device known as the dynamic cone penetrometer (DCP). Findings are presented from a series of DCP tests conducted on a range of granular backfill materials that belong to ASTM D 2321 Classes I and II. These materials were compacted using (a) an impact rammer and (b) a vibratory plate compactor. The level of compaction energy was varied by changing the number of passes. The data obtained from these tests are presented in the form of DCP blow count profiles, which are then used as the basis for comparison between different materials, compaction equipment, and levels of compaction energy. A series of full-scale load tests conducted on high-density polyethylene (HDPE) pipe installations is also described. An overview is provided of how the DCP data may be combined with load-deflection data from full-scale load tests to establish guidelines for compaction control of pipe backfill.
Combined Effects of Normative Information and Task Difficulty on the Goal Commitment-Performance Relationship

The role of normative information, task difficulty and goal commitment on task performance in an assigned goal condition was investigated in a laboratory study using 209 student volunteers. The experiment was a 2 (task difficulty) by 2 (normative information) factorial design. All subjects received assigned difficult goals and normative information indicating how previous individuals had performed on one of two versions of an anagram task (easy or difficult) after which subjects indicated their goal commitment and completed anagrams for a short work period. Results indicated a significant 3-way interaction (task difficulty, normative information and goal commitment) on task performance. Findings suggest that goal commitment moderates the effects of normative information and task difficulty on task performance.
Diffraction management in 2D waveguide arrays

We report on the experimental observation of diffraction management in two-dimensional (2D) "fixed" periodic waveguide arrays in a photorefractive (PR) ferroelectric crystal.
A New Species of Hagenbachia (Anthericaceae) from Ecuador

A new species of Hagenbachia Nees & Mart. (Anthericaceae), H. ecuadorensis Cruden, is described from Ecuador. In addition to being geographically isolated from the other broad-leafed species in Hagenbachia, it has longer pedicels, filaments, and anthers, as well as qualitative differences in other traits.
A high performance implementation of MPI-IO for a Lustre file system environment

It is often the case that MPI-IO performs poorly in a Lustre file system environment, although the reasons for such performance have heretofore not been well understood. We hypothesize that such performance is a direct result of the fundamental assumptions upon which most parallel I-O optimizations are based. In particular, it is almost universally believed that parallel I-O performance is optimized when aggregator processes perform large, contiguous I-O operations in parallel. Our research, however, shows that this approach can actually provide the worst performance in a Lustre environment, and that the best performance may be obtained by performing a large number of small, non-contiguous I-O operations. In this paper, we provide empirical results demonstrating these non-intuitive results and explore the reasons for such unexpected performance. We present our solution to the problem, which is embodied in a user-level library termed Y-Lib, which redistributes the data in a way that conforms much more closely with the Lustre storage architecture than does the data redistribution pattern employed by MPI-IO. We provide a large body of experimental results, taken across two large-scale Lustre installations, demonstrating that Y-Lib outperforms MPI-IO by up to 36p on one system and 1000p on the other. We discuss the factors that impact the performance improvement obtained by Y-Lib, which include the number of aggregator processes and Object Storage Devices, as well as the power of the system's communications infrastructure. We also show that the optimal data redistribution pattern for Y-Lib is dependent upon these same factors. Copyright © 2009 John Wiley & Sons, Ltd.
Sensor Node Localization with Uncontrolled Events

Event-driven localization has been proposed as a low-cost solution for node positioning in wireless sensor networks. In order to eliminate the costly requirement for accurate event control in existing methods, we present a practical design using uncontrolled events. The main idea is to estimate both event generation parameters and the location of sensor nodes simultaneously, by processing node sequences that can be easily obtained from event detections. Besides the basic design, we proposed two enhancements to further extract information embedded in node orderings for two scenarios: (i) node density is high; and (ii) abundant events are available. To demonstrate the generality of our design, both straight-line scan and circular wave propagation events are addressed in the article, and we evaluated the design with extensive simulation as well as a testbed implementation with 41 MICAz motes. Results show that with only randomly generated events, our design can effectively localize nodes with great flexibility while adding little extra cost at the resource constrained sensor node side. In addition, localization via uncontrolled events provides a potential option of achieving node positioning through long-term ambient events.
Kidney transplantation: mechanisms of rejection and acceptance.

We describe the molecular and cellular mechanisms believed to be responsible for the rejection of renal allografts, including acute T cell–mediated rejection, acute antibody-mediated (humoral) rejection, rejection mediated by the innate immune system, and chronic rejection. We present mechanisms of graft acceptance, including accommodation, regulation, and tolerance. Studies in animals have replicated many pathologic features of acute and chronic rejection. We illuminate the pathogenesis of human pathology by reflection from experimental models.
Synaptic Basis of Persistent Activity in Prefrontal Cortex In Vivo and in Organotypic Cultures

Persistent activity is observed in many cortical and subcortical brain regions, and may subserve a variety of functions. Within the prefrontal cortex (PFC), neurons transiently maintain information in working memory via persistent activity patterns; however, the mechanisms involved are largely unknown. The present study used intracellular recordings from deep layer PFC neurons in vivo and patch-clamp recordings from PFC neurons in organotypic brain slice cultures to examine the ionic mechanisms underlying persistent activity states evoked by various inputs. Persistent activity had consistent features regardless of the initiating stimulus; it was driven by non-NMDA glutamate receptors yet consisted of an initial GABA mediated component, followed by a prolonged synaptically mediated inward current that maintained the sustained depolarization on which rode many asynchronous GABA-mediated events. The stereotyped nature of the multiple-component persistent activity pattern reported here might be a common feature of interconnected cortical networks but within PFC could be related to the persistent activity required for working memory.