cssi/SciSciGPT-SciSciNet huggingface dataset:
11C-MC1 has adequate sensitivity to measure low density cyclooxygenase 2 (COX-2) in healthy human brain

103 Introduction: Cyclooxygenase enzymes (COX) are important targets for neuroinflammation. COX-1 is constitutively present at such high density in the brain and periphery that it can measured with PET imaging using a COX-1 selective radioligand (doi: 10.1021/acschemneuro.8b00103). In contrast, COX-2 is present at low density in healthy tissue but can be markedly upregulated by inflammation. 11C-MC1 is a selective and potent radioligand for COX-2, and it detected COX-2 in nonhuman primates after intracerebral injection of an inflammogen. We have found that in patients with rheumatoid arthritis, 11C-MC1 detected upregulated COX-2 in symptomatic joints (doi: 10.1186/s12974-020-01804-6). The purpose of this study was to determine if 11C-MC1 could measure COX-2 in healthy human brain. Methods: Five healthy participants were injected with 11C-MC1 (730 ± 37 MBq) and had two brain PET scans for 120 minutes with concurrent arterial sampling. The baseline scan was followed by one after blockade with celecoxib (600 mg p.o.), a preferential COX-2 inhibitor. Binding to the enzyme was calculated as total distribution volume corrected for free parent fraction in plasma (VT/fp) using a two-tissue compartment model (2TCM), and the receptor occupancy was determined using the Lassen plot. Results: After injection of 11C-MC1, the concentration of brain radioactivity peaked at 4.0 SUV at ~2.8 minutes and declined to 16% of the peak at 120 minutes. The brain time-activity curve was reasonably well-fitted to a 2TCM and provided stable values of VT after 40 minutes (i.e. within 10% of terminal values at 120 min). However, the measured values of VT after 60 minutes were higher than the fitted values, which might reflect accumulation of small amount of radiometabolites in brain. Nondisplaceable uptake (VND), calculated from the Lassen plot, was 80-90% of total uptake, and specific uptake (VS) was only 10-20% of VT. Based on the Lassen plot, celecoxib occupied 86% of available COX-2 in the brain. The regions with the highest amount of specific binding were occipital cortex, insula, and prefrontal cortex. Regional brain distribution of specific binding correlated with that of regional mRNA transcripts of the COX-2 gene obtained from the Allen Brain Atlas. Conclusions: The uptake of 11C-MC1 in healthy human brain reflects specific binding to COX-2 based on blockade by celecoxib and by the PET distribution of the enzyme correlating with the density of the gene transcript. Based on these preliminary results, 11C-MC1 has adequate sensitivity to measure the low-density of COX-2 in a healthy human brain. However, the specific binding was only 10-20% of total uptake, and greater confidence in these results will likely require studying neuroinflammatory disorders with higher density of COX-2. Acknowledgments: Intramural Research Program at the National Institute of Mental Health
Exploring assessment of students from different language backgrounds: A look at reading comprehension using informational texts

Within the United States, a priority has been placed on the area of reading assessment as mandated by the US Department of Education (2004). Confusion still exists as to how to assess students who ...
The yellow and the black of synthetic melanins

The observations reported here are a continuation and expansion of observations described earlier: the typical conditions to synthesize melanin-like materials from catecholic precursors (air-oxidation in an alkaline environment) leads to the generation of a light-colored substance in addition to the typical dark substances. This light-colored substance appears to be associated with the dark-colored materials through non-covalent interactions. We employed a novel co-precipitation process that allows for a simple separation of this light-colored substance from the dark-colored materials. We studied some of the physic-chemical properties (color, fluorescence, FT-IR absorbance) of some of the fractions we obtained and discussed these properties in the context of what has been discussed for eumelanin, pheomelanin or neuromelanin. Overall, the current observations strengthen our hypothesis that synthetic melanins may be built from at least two types of substances: 1) a soluble, yellow-to-orange colored component, possibly rich in unoxidized precursors and 2) an insoluble, dark component. Our observations do suggest that when studying the chemistry or physiology of melanins one should look beyond the dark colors typically displayed by melanin-like materials.
Development, Structure, and Function of Torus–Margo Pits in Conifers, Ginkgo and Dicots

Tracheary elements, the water-conducting cells of the xylem, are connected by bordered pit pairs containing pit membranes. The function of the latter is to allow passage of water but not air embolisms. One type of pit membrane form that has evolved repeatedly consists of a central, impermeable torus surrounded by a permeable margo. This membrane structure is common in gymnosperms, but less so in angiosperms. In this chapter, various ontogenetic sequences for the formation of torus/margo pit membranes are explored. Also, the presence and function of such pit membranes under xeric conditions are discussed.
Coronary sinus obstruction after atrioventricular canal defect repair

The coronary sinus can become obstructed with any instrumentation at or near the ostium such as in atrioventricular canal defect repairs. This complication may lead to a wide range of consequences including dyspnea, angina, myocardial infarction, and sudden death. The following report illustrates the importance of careful perioperative echocardiographic evaluation of the coronary sinus in procedures that may affect the sinus and its ostium.
Toward implementing robust support for portals 4 networks in MPICH

The Portals 4 network specification is a low-level API for high-performance networks developed by Sandia National Laboratories, Intel Corporation, and the University of New Mexico. Portals 4 is specifically designed to support both the MPI and PGAS programming models efficiently by providing building blocks upon which to implement their particular features. In this paper we discuss our ongoing efforts to add efficient and robust support for Portals 4 networks inside MPICH, and we describe how the API semantics influenced our design. In particular, we found the lack of reliability guarantees from the Portals 4 layer challenging to address. To tackle this situation, we implemented an intermediate layer---Rportals (reliable Portals), which modularizes the reliability functionality within our Portals network module for MPICH. In this paper we present the Rportals design and its performance impact.
LAT1 muscle-specific knockout limits early load-induced mTORC1 activity (1102.41)

Leucine exhibits a strong anabolic effect in skeletal muscle: increasing muscle protein synthesis via activation of mechanistic target of rapamycin-complex 1 (mTORC1). Since LAT1 is the primary leu...
Estimation of Process Change for Industrial Pollution Abatement

Abstract When forecasting the impacts of pollution control regulations upon industries which produce pollutants jointly with ordinary outputs, potential input and production process adjustments must be identified and assessed. The problem addressed here is that the empirical approximation of Joint production processes by a single-equation Least Squares (LS) regression misrepresents restrictions on input substitution possibilities. In such cases, some inputs are allocated to both production processes, which provides the jointness. But other inputs contribute to only one process and do not contribute to adjustment opportunities in the other process. Since single-equation LS regression assumes that all inputs can be substituted throughout the production process, its application results in a misspecified empirical model. This paper presents a theoretical framework that motivates the use of Seemingly Unrelated Regression (SUR) estimators to directly approximate such processes. The advantage to using the SUR es...
Adaptive sprinting: How to get the most out of Phase Change based passive cooling

CMOS scaling trends lead to elevated on-chip temperatures, which substantially limit the performance of today's processors. To improve thermal efficiency, Phase Change Materials (PCMs) have recently been used as passive cooling solutions. PCMs store large amount of heat at near-constant temperature during phase change, allowing strategies such as computational sprinting. While existing sprinting methods allow short performance boosts, there is significant unexplored potential in improving performance on systems with PCM-enhanced cooling. To this end, this paper proposes a novel runtime management policy driven by observations that are not captured by prior techniques: (i) PCM melts non-uniformly due to spatially heterogeneous on-chip heat distribution; (ii) power consumption during sprinting is highly application dependent and assuming a fixed sprinting power leads to lower thermal efficiency; (iii) if we monitor the remaining PCM energy at various locations, we can utilize the PCM heat storage capability much more efficiently. The proposed Adaptive Sprinting policy exploits these observations to extend sprinting duration for increased performance gains. Our policy monitors the remaining PCM energy corresponding to each core at runtime, and using this information, it decides on the number, the location and the voltage-frequency (V/f) setting of the sprinting cores. Experimental evaluation including a detailed phase change thermal model demonstrates 29% performance improvement, 22% energy savings, and 43% energy delay product (EDP) reduction on average, compared to prior strategies.
DNA duplex stability of the thio-iso-guanine•methyl-iso-Cytosine base pair.

We report the synthesis, incorporation into oligonucleotides, and base-pairing properties of the 2-thio-variant of iso-guanine. Iso-guanine is the purine component of a nonstandard base pair with 5-methyl-iso-cytosine. The 2-thio-iso-guanine•5-methyl-iso-cytosine base pair is found to have similar stability to an adenine•thymine pair.
Extracurricular Participation and Course Performance in the Middle Grades: A Study of Low-Income, Urban Youth

The transition to middle/junior high school is associated with declines in students’ academic performance, especially among low-income, urban youth. Developmental psychologists posit such declines are due to a poor fit between the needs of early adolescents—industry, identity, and autonomy—and the environment of their new schools. Extracurricular participation during these years may act as a buffer for youth, providing a setting for development outside the classroom. The current study examines participation within and across activity settings among low-income, urban youth in New York City over this transition. Using the Adolescent Pathways Project data, this study explores how such participation relates to course performance. We find that a large percentage of youth are minimally or uninvolved in extracurricular activities during these years; that participation varies within youth across time; and that the association between participation and course performance varies by activity setting. Youth who participate frequently in community or athletic settings or have high participation in two or more settings are found to have higher GPAs in the year in which they participate and youth who participate frequently in the religious setting are found to have lower GPAs. High participation in more than two settings may be detrimental.
Induction of monocyte differentiation and foam cell formation in vitro by 7-ketocholesterol

Oxidized LDL (OxLDL) is composed of many potentially proatherogenic molecules, including oxysterols. Of the oxysterols, 7-ketocholesterol (7-KC) is found in relatively large abundance in OxLDL, as well as in atherosclerotic plaque and foam cells in vivo. Although there is evidence that 7-KC activates endothelial cells, its effect on monocytes is unknown. We tested the hypothesis that 7-KC may induce monocyte differentiation and promote foam cell formation. THP-1 cells were used as a monocyte model system and were treated with 7-KC over a range of concentrations from 0.5 to 10 microg/ml. Changes in cell adhesion properties, cell morphology, and expression of antigens characteristic of differentiated macrophages were monitored over a 7-day period. 7-KC promoted cells to firmly adhere and display morphologic features of differentiated macrophages; this effect was time and dose dependent and was markedly more potent than cholesterol treatment (45% of cells became adherent after 7 days of treatment with 7-KC at 10 microg/ml vs. less then 5% for control cells, P < 0.01). Similar effects were obtained when LDL enriched with 7-KC or OxLDL were added to THP-1 cells. 7-KC-differentiated cells expressed CD11b, CD36, and CD68, phagocytized latex beads, and formed lipid-laden foam cells after exposure to acetylated LDL or OxLDL. In contrast to 7-KC, oxysterols with known cell regulatory effects such as 25-hydroxycholesterol, 7beta-hydroxycholesterol, and (22R)-hydroxycholesterol did not effectively promote THP-1 differentiation. In conclusion, these results demonstrate for the first time that 7-KC, a prominent oxysterol formed in OxLDL by peroxidation of cholesterol, may play an important role in promoting monocyte differentiation and foam cell formation. These studies also suggest that 7-KC induces monocyte differentiation through a sterol-mediated regulatory pathway that remains to be characterized.
Platelet preservation problems

Summary During the past decade efforts to preserve platelets have indicated that storage at 4°C will not maintain functional integrity. The current anticoagulants are acceptable with the proposed modification of ACD solutions. Plastic equipment has been of value to prepare platelet concentrates rapidly. We need to have better plastic materials for the projected temperatures used for storage. While the Cr51 platelet label has been of great value to evaluate methodology, further data are required to determine if isotope labeling of frozen platelets can be used to assess hemostasis. The two preservatives currently used for freezing need comparative studies to define acceptance in a national program. At the present time preservation studies continue to be done in an empiric fashion. Only when we understand platelet membrane functions more completely can we define the cryophysiology of this blood component.
Isozyme expression and gene-centromere distances in diploid and triploid hybrid catfish

Abstract Allozyme expression of 14 loci was studied in diploid channel catfish Ictalurus punctatus, blue catfish I. furcatus, and diploid and triploid hybrid catfish (channel catfish × blue catfish). This allowed appropriate interpretation of allozyme expression and estimates of gene–centromere distances in triploid hybrid catfish and contributed to genetic characterization of the commercially important ictalurid catfishes. Five polymorphic loci in the parental female channel catfish were used to confirm the retention of an extra diagnostic maternal allele in triploid offspring. Fidelity of gene dosage and allozyme expression of three parental alleles were found at 13 of 14 loci of triploid progeny; however, expression of phosphoglucomutase (PGM) in 174 and 197 triploid hybrids was similar to that of diploid hybrids. Electrophoretic variation for PGM was observed when different buffers were used, indicating nongenetic alteration of expression. Two polymorphic loci in triploid hybrid catfish provided new g...
The role of Wino content in neutralino dark matter

We investigate the dark matter prospects of supersymmetric models with nonuniversal gaugino masses at low values of tan{beta}. We find that for particular values of the ratio of soft supersymmetry-breaking gaugino masses, M{sub 2}/M{sub 1}, an enhanced coannihilation efficiency between the lightest chargino and the lightest neutralino occurs. As a specific example, we investigate models of hidden sector gaugino condensation. These models exhibit high scalar masses and the requisite freedom in the ratio of gaugino masses. The cosmologically viable regions of parameter space are investigated, allowing very specific statements to be made about the content of the supersymmetry-breaking hidden sector.
Relationship of students' affective learning to teachers' type A scores.

In a study of 107 college teachers, perceptions of college students' affective learning were positively associated .62 with teachers' self-reported Type A behavior scores.
Arming the campus cops: a descriptive and multivariate assessment of support

The general characteristics of crimes occurring on American college and university campuses have changed, reflecting a much greater frequency and variety of criminal activities. Therefore, many campus police departments are considering alternative mechanisms aimed at crime control and diminishing the fear levels of constituents. While most municipal police agencies routinely arm themselves, traditionally, armed police forces have been uncharacteristic of campus law enforcement, especially at smaller, rural and suburban schools. The present research assesses campus constituency support and rationale for arming the police force at one university. Constituent status, gender, fear of crime, outcome of contact with an officer, and political ideology are among the variables discussed in relation to this contemporary issue.
Microstructural stability, microhardness and oxidation behaviour of in situ reinforced Ti-8.5Al-1B-1Si (wt %)

Microstructural stability, microhardness and oxidation behaviour of an in situ reinforced Ti–8.5Al–1B–1Si (wt%) alloy was examined in both air and argon environments. When exposed for up to 5760 min at temperatures below the α/α+α2 transius, hardening occurred in both air and argon environments. The increase in hardness in the air heat-treated samples is attributed to a combination of solid-solution strengthening due to the oxygen and the precipitation of the α2 phase, while the increase in hardness in the argon heat-treated samples is primarily due to the precipitation of the α2 phase. On the other hand, when heat treated above the α/α+α2 transius, after an initial increase in hardness there is a drop in hardness which is attributed due to elimination of the α2 phase and a decreased contribution of boron and silicon in the matrix towards the solid-solution strengthening by virtue of coarsening of the TiSi2 and TiB reinforcements. Oxidation of the alloys follows a parabolic oxidation law when oxidized both in an environment of flowing air and static air with the primary oxidation product being TiO2. The activation energy for oxidation is 200 kJ mol-1 in an environment of flowing air and 303 kJ mol-1 in static air. The difference in activation energy arises from the difference in the availability of oxygen at the reaction front in the two cases. © 1998 Chapman & Hall
Monolithically integrated widely tunable 40Gbits/s wavelength converter with optical label modulation function

What we believe to be a novel monolithically integrated wavelength converter consisting of a sampled grating distributed Bragg reflector laser, a long semiconductor optical amplifier (SOA), and a delayed interferometer Mach-Zehnder interferometer (DIMZI) is reported. Error-free 40Gbits/s wavelength conversion for three different probe wavelengths is demonstrated. The impact of the output filter bandwidth and filter detuning on the performance of wavelength conversion is studied in detail. The optical label modulation of the on-chip DI-MZI is first demonstrated with amplitude- and phase-shift key schemes.
Determination Of Fluorescent Quantum Yields Using Pulsed-Laser Photoacoustic Calorimetry

Pulsed-laser, time-resolved photoacoustic calorimetry is a technique which provides information on nonradiative channels of deactivation of molecular excited states. It is thus complementary to fluorescence techniques, and can provide information on fluorescent quantum yields. This paper describes pulsed photoacoustic calorimetry, how the data can be deconvolved to give dynamic and enthalpic information, and how this information can be used to determine fluorescent quantum yields.
The disposition of citric acid cycle intermediates by isolated rat heart mitochondria

The mechanism of depletion of tricarboxylic acid cycle intermediates by isolated rat heart mitochondria was studied using hydroxymalonate (an inhibitor of malic enzymes) and mercaptopicolinate (an inhibitor of phosphoenolpyruvate carboxykinase) as tools. Hydroxymalonate inhibited the respiration rate of isolated mitochondria in state 3 by 40% when 2 mM malate was the only external substrate, but no inhibition was found with 2 mM malate plus 0.5 mM pyruvate as substrates. In the presence of bicarbonate, arsenite and ATP propionate was converted to pyruvate and malate at the rates of 14.0 +/- 2.9 and 2.8 +/- 1.8 nmol/mg protein in 5 min, respectively. Under these conditions, 0.1 mM mercaptopicolinate did not affect this conversion, but 2 mM hydroxymalonate inhibited pyruvate formation completely and resulted in an accumulation of malate up to 13.2 +/- 2.9 nmol/mg protein. No accumulation of phosphenolpyruvate was found under any condition tested. It is concluded that malic enzymes but not phosphoenolpyruvate carboxykinase, are involved in conversion of propionate to pyruvate in isolated rat heart mitochondria.
YBa/sub 2/Cu/sub 3/O/sub 7/

Some background information on superconducting ceramics is given, and the history of yttrium barium copper oxide (YBCO) is discussed. The crystal structure of superconducting YBCO is described. The production and extraction methods of bulk samples of YBCO are detailed. Different theories of superconductivity in YBCO are addressed, and applications of YBCO superconductors are discussed. >
A contribution to the concept "the exception" as a developmental phenomenon.

Abstract The sense of “entitlement” or of being an exception has been noted in people who have suffered from severe childhood deformities or from other forms of severe deprivation. In such cases it constitutes a restitution for earlier suffering. In this vignette from the treatment of a patient who, because of sexual abuse by her mother, did not feel that she owned her own genitals, the sense of entitlement represented a developmental step toward ownership of her own body.
The Development of Monoclonal Antibodies for the Therapy of Cancer

Monoclonal antibodies (Mabs) were first described by Kohler and Milstein in 1975. Not only did this discovery lead to a Nobel prize, but it created an enormous scientific field that has now become a multimillion dollar industry. Mabs made the transition from laboratory reagents to clinical diagnostics very quickly. However, their development as therapeutic agents was, as predicted, more costly and time-consuming. Indeed, clinicians and scientists were required to learn a new set of rules for using these large, immunogenic, targeted agents in humans. Nevertheless, in 1997 the first Mab was licensed in the U.S. and several others will soon follow. In this review, we discuss Mab-based strategies for the treatment of cancer. We compare native, fragmented, recombinant and chimeric antibodies, bispecific antibodies, immunoconjugates, and immunoliposomes. The rationale for their development, their advantages, their in vitro and in vivo performance, and their clinical usefulness are discussed.
Sliders and tension controlled reinforced elastomeric bearings combined for earthquake isolation

Essential requirements from a base isolation system include wind restraint, stability and fail-safe capacity. A new base isolation system that satisfies all three requirements and possesses other advantages was tested on the earthquake simulator at the University of California under the base of a one-fourth scale nine storey steel structure. The base behaves as fixed for low magnitude inputs. When sliding starts the rubber bearings provide additional stiffness and recentering. Displacements are better controlled than the ones for a purely elastomeric isolation system. Vertical deflections due to large horizontal drift encountered in solely rubber systems are eliminated. The fail safe capacity is provided by tension restrainers installed inside the rubber bearings, and by the constant contact of the base with the sliders. Base shear hysteresis loops are drastically enlarged by the presence of the sliders.
THE INFLUENCE OF IMMUNOLOGICALLY COMMITTED LYMPHOID CELLS ON MACROPHAGE ACTIVITY IN VIVO

It has been shown that the immune response of mice to infection with L. monocytogenes gives rise to a population of immunologically committed lymphoid cells which have the capacity to confer protection and a proportionate level of delayed-type hypersensitivity upon normal recipients. The cells were most numerous in the spleen on the 6th or 7th day of infection, but persisted for at least 20 days. Further study revealed that the immune cells must be alive in order to confer protection, and free to multiply in the tissues of the recipient if they are to provide maximum resistance to a challenge infection. The antibacterial resistance conferred with immune lymphoid cells is not due to antibacterial antibody; it is mediated indirectly through the macrophages of the recipient. These become activated by a process which appears to depend upon some form of specific interaction between the immune lymphoid cells and the infecting organism. This was deduced from the finding that immune lymphoid cells from BCG-immunized donors, which were highly but nonspecifically resistant to Listeria, failed to protect normal recipients against a Listeria challenge unless the recipients were also injected with an eliciting dose of BCG. The peritoneal macrophages of animals so treated developed the morphology and microbicidal features of activated macrophages. It is inferred that acquired resistance depends upon the activation of host macrophages through a product resulting from specific interaction between sensitized lymphoid cells and the organism or or its antigenic products. Discussion is also made of the possibility that activation of macrophages could be dependent upon antigenic stimulation of macrophages sensitized by a cytophilic antibody.
Metabolic studies on the micropinocytic process in endothelial cells.

Abstract Tufts of capillary endothelium isolated from rat epididymal fat ingest [ 14 C]sucrose by the process of micropinocytosis. Ingestion of sucrose for periods in excess of 30 min was quantitated using the concentration of cellular DNA as a standard. Capillaries incubated in the metabolic inhibitors 2,4-dinitrophenol, NaN 3 , or iodoacetate exhibit a dose-dependent reduction of cellular ATP. Micropinocytic ingestion of [ 14 C]sucrose is not affected by concentrations of these inhibitors which markedly reduce or deplete ATP pools. Pure oxygen or nitrogen atmospheres also have no effect on micropinocytosis. Ingestion of [ 14 C]sucrose is reduced, however, at temperatures lower than 37° or in the presence of Zn 2+ .
Travel behaviors, sustainable mobility, and transit-oriented developments: a travel counts analysis of older adults in the Denver, Colorado metropolitan area

As older adults become a larger portion of the U.S. population, new research examines the changing travel behaviors and needs of older adults in cities, especially in light of aging in place and active aging trends. Using descriptive statistics and regression models, this paper analyzes the trips, distances, mode choices, trip purposes, and time of day travel characteristics for older adults. It provides empirical evidence of basic travel behaviors and needs of older adults, examines heterogeneous characteristics between four different age groups, and focuses on sustainable mobilities, particularly the influence of transit-oriented developments. The data come from a 2009 travel-counts survey of the Denver, Colorado, (U.S.) metropolitan area, and include 4268 adults aged 60 and over, and 15,678 total trip activities. Consistent with existing research, total trips and mean distances decline with age, and mode of travel shifts away from car-driver. Each age group exhibits unique behaviors. For instance, the 75 to 84-year-old group is most mobile by car, and least by walking or transit. The models reveal that factors relating to changes in travel behaviors are quite complex, suggesting the need for research that examines lifestyle clusters more so than age and age groups.
Scattering by plasmon polaritons on a rough surface with a periodic component

We investigate the scattering properties of a metal surface composed of the sum of a sinusoidal component and a one-dimensional Gaussian random process. In experimental work, such surfaces are produced in gold-coated photoresist by combining speckle-scanning methods with holographic grating fabrication techniques. In the diffusely scattered light, light bands and related effects that arise from the excitation of surface plasmon polaritons are observed; the angular position of the diffuse light bands corresponds to the positions of the resonant absorption anomalies of the unperturbed periodic surface. It is also shown that the measurements are closely consistent with the predictions of rigorous numerical methods based on the reduced Rayleigh equations, in which the diffuse scatter is determined through an average over an ensemble of rough surfaces. With an analytical theoretical method that treats the grating exactly and the roughness as a perturbation, it is shown that an observed enhancement of a diffuse light band in the backscattering configuration results from the coherent interference of scattering contributions from counterpropagating surface plasmon polaritons.
Robustness of methane diffusion in geometrically restricted molecular sieve pores

NMR measurements of sorbate mobility in zeolites are especially attractive because of their capability of measuring multicomponent and anisotropic self-diffusion. We have recently reported the application of the pulsed field gradient NMR technique using very large zeolite crystals to study how easily methane can diffuse when we attempt to slow its migration by crowding the pore space. Here we analyze the implications of these PFG NMR experiments involving (i) ethylene blocking of methane in zeolite NaY; and (ii) methane molecules trying to pass one another in the molecular sieve A1PO4-5.
On extreme points of bounded sets of generalized finite sequence spaces

The Linear Independence Extreme Point Theorem and Opposite Sign Theorem of semiinfinite programming provide algebraic characterizations of unbounded infinite dimensional convex polyhedral sets in terms of their extreme points. The Charnes, Kortanek, and Raike purification algorithm, which transforms any non-extreme point to an extreme point having objective function value at least as great, is based upon the constructive proofs of these two theorems.
G-Protein activation mediates prepulse facilitation of Ca2+ channel currents in bovine chromaffin cells

The effects of G-protein activation were investigated on tonic, large depolarization-induced Ca2+ channel facilitation in cultured bovine adrenal chromaffin cells. Under whole-cell voltage clamp, activation of G proteins by intracellular dialysis with 200 μM GTP-γS did not significantly affect prepulse facilitation or whole-cell Ba2+ current (I Ba) density. In contrast, inactivation of G proteins by intracellular GDP-βS or pertussis toxin (PTX) pretreatment completely abolished or markedly attenuated facilitation of I Ba, respectively. GDP-βS dialysis resulted in nearly a threefold increase in peak I Ba density, whereas PTX pretreatment resulted in a 50% increase. Our results indicate that under control recording conditions (200 μm intracellular GTP), G proteins are tonically activated and suppress high-voltage-activated (HVA) Ca2+ channels in a voltage-dependent and voltage-independent manner. Local superfusion of chromaffin cells with normal bath solution produced a rapid and reversible increase (∼50%) in I Ba amplitudes that also abolished prepulse facilitation. Together, these results demonstrate that tonic facilitation of HVA Ca2+ channels in bovine chromaffin cells involves the voltage-dependent relief of a G-protein-mediated suppression, imposed by chromaffin cell secretory products that feedback and activate G-protein-coupled autoreceptors.
Meperidine's effects under shock titration and shock discrimination procedures ☆

Meperidine's effects were examined under a schedule of shock titration and under a shock intensity discrimination in which squirrel monkeys discriminated between the presence and absence of a low intensity shock. Meperidine did not increase the intensity at which monkeys maintained the shock in the shock titration procedure, nor did meperidine alter the percentage of correct responses under the shock intensity discrimination although meperidine did increase the time to respond in the presence and absence of shock. When meperidine was combined with a dose of SKF-525A, which did not alter responding when given alone, the intensity at which monkeys maintained the shock under the shock titration procedure was increased. Moreover, the percentage of correct responses in the presence of shock under the shock titration procedure was decreased by the combination of meperidine and SKF-525A.
Development and 3D Finite Element Implementation of a Multiaxial Constitutive Relation for Abdominal Aortic Aneurysms

Abdominal aortic aneurysm (AAA), a localized dilation of the infrarenal aorta, represents a significant disease in the western population. There are approximately 200,000 patients in the US and 500,000 patients worldwide diagnosed with AAAs every year (Bosch, et al. 2001), and rupture of AAAs currently ranks as the 13th leading cause of death in the US. (Silverberg and Lubera 1987) In the past 30 years, the diagnosis of AAA has tripled in the Western world, and this will likely increase in the coming years as the average age of the population is increasing. (Bosch, et al. 2001)Copyright © 2004 by ASME
The conversion of d-glucono-1,5-lactone into an α-pyrone derivative

Abstract Treatment of d -glucono-1,5-lactone ( 3 ) with excess of acetic anhydride in anhydrous pyridine at room temperature afforded the tetra-acetate and 2,4,6-tri- O -acetyl-3-deoxy- d - erythro -hex-2-enono-1,5-lactone ( 1 ). On prolonged reaction or at 80°, 3-acetoxy-6-acetoxymethylpyran-2-one ( 5 ) was the unexpected main product. The mechanistic implications of the conversion of 1 → 5 are discussed.
A numerical model of crevice corrosion for passive and active metals

Abstract A transient mathematical and numerical model for crevice corrosion is presented. The model is general in format and applicable to a variety of metallic and electrolyte systems. It allows consideration of electrode kinetics including both cathodic and anodic reactions with an active/passive transition. Chemical reactions in solution are generalized to facilitate simulation of a variety of electrolytes. The model is applied to experimental data on crevice corrosion initiation in stainless steel and to experiments on active crevice corrosion of iron.
What is an ‘elasmobranch’? The impact of palaeontology in understanding elasmobranch phylogeny and evolution

The Subclass Elasmobranchii is widely considered nowadays to be the sister group of the Subclass Holocephali, although chimaeroid fishes were originally classified as elasmobranchs along with modern sharks and rays. While this modern systematic treatment provides an accurate reflection of the phylogenetic relationships among extant taxa, the classification of many extinct non-holocephalan shark-like chondrichthyans as elasmobranchs is challenged. A revised, apomorphy-based definition of elasmobranchs is presented in which they are considered the equivalent of neoselachians, i.e. a monophyletic group of modern sharks and rays which not only excludes all stem and crown holocephalans, but also many Palaeozoic shark-like chondrichthyans and even close extinct relatives of neoselachians such as hybodonts. The fossil record of elasmobranchs (i.e. neoselachians) is reviewed, focusing not only on their earliest records but also on their subsequent distribution patterns through time. The value and limitations of the fossil record in answering questions about elasmobranch phylogeny are discussed. Extinction is seen as a major factor in shaping early elasmobranch history, especially during the Triassic. Extinctions may also have helped shape modern lamniform diversity, despite uncertainties surrounding the phylogenetic affinities of supposedly extinct clades such as cretoxyrhinids, anacoracids and odontids. Apart from these examples, and the supposed Cretaceous extinction of ‘sclerorhynchids’, elasmobranch evolution since the Jurassic has mostly involved increased diversification (especially during the Cretaceous). The biogeographical distribution of early elasmobranchs may be obscured by sampling bias, but the earliest records of numerous groups are located within the Tethyan realm. The break-up of Gondwana, and particularly the opening of the South Atlantic Ocean (together with the development of epicontinental seaways across Brazil and Africa during the Cretaceous), provided repeated opportunities for dispersal from both eastern (European) and western (Caribbean) Tethys into newly formed ocean basins.
Central effects of dibutyryl cyclic AMP and GMP on the temperature in conscious rabbits

Abstract Intracerebroventricular (i.c.v.) administration of dibutyryl cyclic AMP (Db-cAMP)- and dibutyryl cyclic GMP (Db-cGMP)-induced hyperthermia in rabbits. Central administration of 4-(3-cyclopentyloxy-4-methoxyphenyl)-2-pyrrolidone (ZK 62711), a selective inhibitor of cAMP phosphodiesterase, only accentuated the hyperthermia due to Db-cAMP whereas a selective inhibitor of cGMP phosphodiesterase, 2-O-proproxyphenyl-8-azapurin-6-one (M and B 22948), only potentiated the hyperthermia caused by Db-cGMP. The hyperthermia due to Db-cAMP and Db-cGMP was not mediated through prostaglandins (PG). In contrast, central administration of an α-adrenergic receptor antagonist, phenoxybenzamine, or a β-adrenergic receptor antagonist, sotalol, only attenuated the hyperthermic response to Db-cAMP while a cholinergic muscarinic receptor antagonist, atropine, specifically antagonized Db-cGMP-induced hyperthermia. I.c.v. administration of a protein synthesis inhibitor, anisomycin, did inhibit the hyperthermia due to Db-cAMP and Db-cGMP. Opiate antagonist, naloxone, did not antagonize Db-cAMP- nd Db-cGMP-induced hyperthermia. These results suggest that a protein mediator is implicated in the induction of hyperthermia by Db-cAMP and Db-cGMP and that cAMP and cGMP may be involved through α/β-adrenergic and cholinergic muscarinic receptors respectively in the central regulation of heat production/conservation in rabbits.
Recovery of a Sendai virus variant with temperature-sensitive hemolytic activity from persistently infected cells from mouse brain.

A persistently infected cell line designated MB/SenAS was established by cultivation of mouse brain cells from four-day-old C3H mice infected intracerebrally at birth with 106 PFU of Sendai virus, strain 52. After 5 passages, 0.16 per cent of Sendai52 antiserum (containing two 50 per cent plaque reducing doses/ml of serum) was introduced into the culture medium. The addition of antiserum was accompanied by a rise in cell-associated viral antigen from a level of 5 per cent antigen positive cells to 100 per cent demonstrable by both intracellular and membrane immunofluorescence.
Cloning, nucleotide sequence and mutational analysis of the gene encoding the Photosystem II manganese-stabilizing polypeptide of Synechocystis 6803.

Affinity purified, polyclonal antibodies raised against the Photosystem II 33 kDa manganese-stabilizing polypeptide of the spinach oxygen-evolving complex were used to isolate the gene encoding the homologous protein from Synechocystis 6803. Comparison of the amino acid sequence deduced from the Synechocystis psb1 nucleotide sequence with recently published sequences of spinach and pea confirms the homology indicated by antigenic crossreactivity and shows that the cyanobacterial and higher plant sequences are 43% identical and 63% conserved. Regions of identity, varying in length from 1 to 10 consecutive residues, are distributed throughout the protein. The 28 residues at the amino terminus of the psb1 gene product, characteristic of prokaryotic signal peptides, show homology with the carboxyl-terminal third of the transit sequences of pea and spinach and are most likely needed for the transport of the manganese-stabilizing protein across the thylakoid membrane to its destination of the lumen. Synechocystis mutants which contain a kanamycin resistance gene cassette inserted into the coding region for the 32 kDa polypeptide were constructed. These mutants contain no detectable 32 kDa polypeptide, do not evolve oxygen, and are incapable of photoautotrophic growth.
Analysis of the effects of orography on surface rainfall by a parameterized numerical model

Abstract A numerical model is formulated for estimating the spatial distribution of rainfall on the meso-local scale. Widespread rainfall not influenced by convective processes is considered. The observed rainfall on the soil surface unaffected by orographically produced contributions and meteorological parameters on the large scale are used as inputs to the model. It is then used for computing the spatial distribution of rainfall incorporating the orographic effects in a parameterized form. The model is applied to four rainfall events over an area of the Upper Tiber River, central Italy, basin and the results compare reasonably well with the observations in each event. The error in computing mean areal rainfall ranges in magnitude from 1% to 15% and further for each event at least 75% of the pointestimates has an error of less than ± 30%.
Drop formation at the surface of plane turbulent liquid jets in still gases

Abstract An experimental study of drop formation at the free surface of plane turbulent jets in gases (i.e., turbulent primary breakup) is described. Test conditions consisted of fully-developed turbulent plane water jets injected into still air at standard temperature and pressure with Reynolds numbers of 91,000–424,000, Weber numbers of 13,000–151,000 and Ohnesorge numbers of 0.0009–0.0012. Pulsed shadowgraphy was used to measure mean liquid surface velocities, mean and fluctuating drop velocities after primary breakup, drop sizes after primary breakup and the location of the onset of primary breakup. Drop velocities were related to the average streamwise velocity in a relatively simple manner, while drop size properties could be related to earlier findings for turbulent primary breakup of round liquid jets in still gases using hydraulic diameter concepts.
A strong form of the isoperimetric inequality in Rn

On etablit l'analogue d'un resultat de Fuglede relatif a une forme forte de l'inegalite isoperimetrique dans R n
Associative intrusions in short-term recall: A replication of Wickelgren

Thirty-two undergraduates listened to lists of nine letters presented at the rate of four letters per second and then attempted to recall the letters in the correct order. Letters following repeated letters tended to be interchanged in recall. Such associative intrusions were observed whether the repeated letters occurred at the beginning or middle of the lists, whether they were separated by one or two letters, and whether or not the items following the repeated items had a common vowel phoneme. Except for a failure to confirm the backward intrusion phenomenon, the results agreed with the earlier findings of Wickelgren (1966) and added to the data base supporting Wickelgren (1969).
A polarized partition relation using elementary substructures

Working in ZFC, we show that for any infinite cardinal X and ordinal y < (2<N)+ the polarized partition relation (2<)?)+ ((2<n)? V 's + 1i (2 `) J (2<-)' + I holds. Our proof of this relation involves the use of elementary substructures of set models of large fragments of ZFC. ?1. A brief introduction. In [5, Theorem 39, pp. 172-176] it is proven by P. Erdos, A. Hajnal, and R. Rado that GCH implies for every infinite cardinal x. The theorem indicated in the abstract (Theorem 2, below) generalizes and strengthens this result. The techniques used in the proof of [5, Theorem 39] are rather specific to the authors' assumption of GCH, and it is unclear to us how those methods might be extended to provide a proof of our Theorem 2, which makes no such assumption. The proofs presented here were inspired by those of the Erdos-Rado Theorem found in [1, Section 2, pp. 3-4] and [8, Section 2, pp. 244-245]. For the reader unfamiliar with the use of elementary substructures in infinite combinatorics, we recommend both [1] and [8] as good resources. ?2. A few remarks on our notation. Our set theoretic notation is essentially that of [7, Part I]. If x is a set of ordinals, then ot(x) is the unique ordinal a such that there is an order isomorphism between (x, c) and (a, c). If x is a set of ordinals and a is an ordinal, then [x] = {y C x I ot(y) = a} and [x]< = {y C x I ot(y) < l}. Cardinals are identified with initial ordinals. If x is any set and K is a cardinal, then [x]< = y{y C x I IyI < K}. If Es is a cardinal, then i,+ is the least cardinal greater Received February 10, 1998; revised November 4, 1998. 1991 Mathematics Subject Classification. 03E05, 04A20, 05A18, 05D10.
Shielded Sliding Discharge-Assisted Hydrocarbon Selective Catalytic Reduction of NO x over Ag/Al 2 O 3 Catalysts Using Diesel as a Reductant

The nonthermal plasma generated in a shielded sliding discharge reactor was used to reform diesel for the hydrocarbon-selective catalytic reduction (HC-SCR) of NOx on Ag/Al2O3 catalysts. Compared with raw diesel, the reformed diesel enhanced the NOx reduction efficiency, mitigated hydrocarbon poisoning of the catalyst and reduced the fuel penalty for the HC-SCR reaction. The NOx conversion values obtained with a commercial Ag/Al2O3 catalyst exceeded that of a 2.0 wt% Ag/Al2O3 catalyst prepared by wet impregnation. A significant amount of NH3 was produced as a by-product during the HC-SCR reaction, which suggests that further NOx conversion enhancement can be achieved by placing a second NH3-SCR catalyst in series with the Ag/Al2O3 catalyst.