cssi/SciSciGPT-SciSciNet huggingface dataset:
Cellular antioxidant status and human immunodeficiency virus replication.

The factors that stimulate replication of the human immunodeficiency virus (HIV) and determine the period of disease latency are poorly understood. Recent evidence from in vitro cell culture studies of HIV-infected cells suggest that HIV activity is profoundly affected by the presence of antioxidants, such as glutathione and ascorbic acid, in the cell culture medium. These in vitro observations and reports of global glutathione deficiency in nonsymptomatic HIV-seropositive subjects suggest that cellular antioxidant status may be an important factor determining the latency period of HIV infection. The molecular mechanisms underlying HIV activation are beginning to be understood and point to a potentially important role for NF-kB, a cellular transcription factor that may be modulated by cellular antioxidant status.
Toxicokinetic and mechanistic basis for the safety and tolerability of liposomal amphotericin B

Introduction: Amphotericin B (AmB) was first approved by the US Food and Drug Administration in 1959 with sodium deoxycholate (DAmB, Fungizone®). Extensive toxicities associated with the drug led to the development of lipid formulations of AmB, including liposomal amphotericin B (L-AmB, AmBisome®). Phase I studies as well as comparative Phase III clinical trials indicate that L-AmB is associated with less nephrotoxicity and reduced infusion-related toxicity. There is, however, no recent comprehensive review of the safety and tolerability of L-AmB. Areas covered: This article reviews the safety, tolerability and the mechanisms of the major toxicities associated with L-AmB, including nephrotoxicity, infusion-related reactions (IRRs), anemia and thrombocytopenia, and hepatic abnormalities. The article further discusses the mechanism of action and pharmacokinetics of L-AmB. Expert opinion: L-AmB is a broad-spectrum antifungal agent that has significantly reduced toxicities compared to its predecessor, DAmB.
Traction of Lubricated Rolling Contacts between Thin-Film Coatings and Steel

Tribological thin-film coatings can enhance the performance of mechanical components such as bearings and gears. Although a lubricant is present in most applications, the interactions of the lubricant with the coated surfaces are not always well understood. In the present study, Stribeck curves (i.e., traction coefficient vs. dimensionless film thickness λ) were generated for lubricated rolling contact between coated and uncoated surfaces. Chromium nitride, tungsten carbide–reinforced amorphous hydrocarbon, and silicon-incorporated diamond-like carbon coatings were evaluated. Compositions, hydrogen concentrations, Raman spectra, and surface energies are reported for the films. A ball-on-flat test configuration was used in 5%, 50%, and 100% slide-to-roll conditions. The test lubricant was a polyalphaolefin containing rust and oxidation inhibitor additives only. Differences in traction performance were observed for different coating types. Traction coefficients decreased at high λ with increased hydrocarbon...
OMP decarboxylase: phosphodianion binding energy is used to stabilize a vinyl carbanion intermediate.

Orotidine 5′-monophosphate decarboxylase (OMPDC) catalyzes the exchange for deuterium from solvent D2O of the C-6 proton of 1-(β-d-erythrofuranosyl)-5-fluorouracil (FEU), a phosphodianion truncated...
Hepatic triacylglycerol hydrolysis regulates peroxisome proliferator-activated receptor α activity

Recent evidence suggests that fatty acids generated from intracellular triacylglycerol (TAG) hydrolysis may have important roles in intracellular signaling. This study was conducted to determine if fatty acids liberated from TAG hydrolysis regulate peroxisome proliferator-activated receptor α (PPARα). Primary rat hepatocyte cultures were treated with adenoviruses overexpressing adipose differentiation-related protein (ADRP) or adipose triacylglycerol lipase (ATGL) or treated with short interfering RNA (siRNA) targeted against ADRP. Subsequent effects on TAG metabolism and PPARα activity and target gene expression were determined. Overexpressing ADRP attenuated TAG hydrolysis, whereas siRNA-mediated knockdown of ADRP or ATGL overexpression resulted in enhanced TAG hydrolysis. Results from PPARα reporter activity assays demonstrated that decreasing TAG hydrolysis by ADRP overexpression resulted in a 35–60% reduction in reporter activity under basal conditions or in the presence of fatty acids. As expected, PPARα target genes were also decreased in response to ADRP overexpression. However, the PPARα ligand, WY-14643, was able to restore PPARα activity following ADRP overexpression. Despite its effects on PPARα, overexpressing ADRP did not affect PPARγ activity. Enhancing TAG hydrolysis through ADRP knockdown or ATGL overexpression increased PPARα activity. These results indicate that TAG hydrolysis and the consequential release of fatty acids regulate PPARα activity.
Structure-activity relationships of the melanocortin tetrapeptide Ac-His-DPhe-Arg-Trp-NH2 at the mouse melanocortin receptors Part 3: Modifications at the Arg position

The melanocortin pathway is an important participant in obesity and energy homeostasis. The centrally located melanocortin-3 and melanocortin-4 receptors (MC3R, MC4R) are involved in the metabolic and food intake aspects of energy homeostasis and are stimulated by melanocortin agonists such as α-melanocyte stimulation hormone (α-MSH). The melanocortin agonists contain the putative message sequence “His-Phe-Arg-Trp”, and it has been well documented that inversion of chirality of the Phe to DPhe results in a dramatic increase in melanocortin receptor potency. Herein, we report a tetrapeptide library based on the template Ac-His-DPhe-Arg-Trp-NH2, consisting of 17 members that have been modified at the His6 position (α-MSH numbering) and pharmacologically characterized for agonist activity at the mouse melanocortin receptors MC1R, MC3R, MC4R, and MC5R. These studies provide further experimental evidence that the His6 position can determine MC4R versus MC3R agonist selectivity and that chemically nonreactive s...
Murine immune responses to a novel schistosome egg antigen, SmEP25.

Abstract Pathology in schistosomiasis consists of granuloma formation around parasite eggs. There is considerable variation in the severity of disease in individuals with schistosomiasis, which may result from differential responses to egg antigens. The egg-induced immunopathology is mediated by CD4 + T helper cells sensitised to egg antigens. In this study, cellular responses to a 25-kDa fraction of egg proteins identified a novel T-cell antigen, SmEP25. The native SmEP25 elicited significant proliferative responses as well as gamma interferon (IFN-γ), IL-2, IL-4, and IL-5 secretion in CD4 + cells from 8.5-week infected CBA and C57BL/6 mice. In C57BL/6 mice, proliferative responses to SmEP25 were relatively stronger than those directed against the major egg antigen Sm-p40, whereas in CBA mice the reverse was found. SmEP25 elicited stronger Th2 type response than Sm-p40 in both mouse strains. By comparison, recombinant SmEP25 elicited a smaller, Th1-polarised response, with significant IFN-γ, low levels of IL-5 and essentially no IL-4. B-cell responses to SmEP25 coincided with the start of parasite egg production and SmEP25 protein was restricted to parasite eggs. The systematic identification of T-cell-sensitising egg components will lead to a better understanding of the processes involved in granuloma formation.
The decreased cyclic-AMP dependent-protein kinase A function in the nucleus accumbens: a role in alcohol drinking but not in anxiety-like behaviors in rats.

The nucleus accumbens (NAc) brain structures have been implicated in the reward and reinforcing properties of ethanol. The present study investigated the role of nucleus accumbal cyclic AMP (cAMP)-dependent protein kinase A (PKA) signaling in alcohol drinking and anxiety-like behaviors of rats. It was found that infusion of PKA inhibitor (Rp-cAMP) into the NAc shell significantly increased the alcohol but not the sucrose intake, without modulating the anxiety-like behaviors, as measured by elevated plus maze test in rats. PKA inhibitor infusion into the NAc shell significantly decreased the protein levels of α-catalytic subunit of PKA (PKA-Cα) and phosphorylated cAMP response element-binding protein (p-CREB) as well as decreased the protein levels of neuropeptide Y (NPY) in the shell but not in the NAc core of rats. On the other hand, infusion of PKA activator (Sp-cAMP) or NPY alone into the NAc shell did not produce any changes in alcohol intake; however, when these agents were coinfused with PKA inhibitor, they significantly attenuated the increases in alcohol preference induced by pharmacological inhibition of PKA. Interestingly, PKA activator coinfusion with PKA inhibitor into the NAc shell significantly normalized the PKA inhibitor-induced decreases in the protein levels of PKA-Cα and p-CREB as well as of NPY in the NAc shell of rats. Taken together, these results provide the first evidence that decreased PKA function in the NAc shell is involved in alcohol drinking but not in anxiety-like behaviors of rats. Furthermore, decreased function of PKA may regulate alcohol drinking behaviors via CREB-mediated decreased expression of NPY in the NAc shell of rats.
Electrical, chemical, and topological addressing of mammalian cells with microfabricated systems.

This communication describes our work in electrical, topological, and chemical micromodification of surfaces to modulate cellular form and function. We have addressed the surface physico-chemico-mechano properties of cell culture substrates that play a role in modulating cellular behavior. Single factorial model systems have been built using techniques adapted from microlithography. The tools and techniques of microfabrication, if harnessed and used correctly, can be enabling in elucidating the underlying principles and fundamental forces driving the cell-substrate interface. Additionally, the long-term practical applications of microfabrication in medicine and biomaterial/tissue engineering lie in enabling communication' with living cells/tissues at the cellular and subcellular levels.
Vacuum tunneling probe: A nonreciprocal, reduced-back-action transducer.

The vacuum tunneling probe used in the scanning tunneling microscope represents a new class of nonreciprocal electromechanical transducers. Nonreciprocity implies reduced back action and consequently increased sensitivity over conventional, reciprocal transducers. A vacuum tunneling probe may reach the quantum limit for a measurement of the position of a macroscopic mechanical oscillator even with use of a non-quantum-limited amplifier. The quantum limit is enforced by the momentum shot noise associated with the tunneling current.
Analysis and Testing of High Temperature Fibrous Insulation for Reusable Launch Vehicles

Analytical models were developed to model the heat transfer through high-temperature fibrous insulation used in metallic thermal protection systems on reusable launch vehicles. The optically thick approximation was used to simulate radiation heat transfer through the insulation. Different moddels for gaseous conduction and solid conduction in the fibers, and for combining the various modes of heat transfer into a local, volume-averaged, thermal conductivity were considered. The governing heat transfer equations were solved numerically, and effective thermal conductivities were calculated from the steady-state results. An experimental appartatus was developed to measure the apparent thermal conductivity of insulation subjected to pressures, temperatures and temperature gradients representative of re-entry conditions for launch vehicles. The apparent thermal conductivity of an alumina fiber insulation was measured at nominal densities of 24, 48, and 96 kg/m3. Data were obtained at environmental pressures from 10minus4 to 760 torr, with the insulation cold side maintained at room temperature and its hot side temperature varying up to 1000 degrees C. The experimental results were used to evaluate the analytical models. The best analytical model resulted in effective thermal conductivity predictions that were within 8 percent of experimental results.
Agile Software Development: Adaptive Systems Principles and Best Practices

Abstract Today's environments of increasing business change require software development methodologies that are more adaptable. This article examines how complex adaptive systems (CAS) theory can be used to increase our understanding of how agile software development practices can be used to develop this capability. A mapping of agile practices to CAS principles and three dimensions (product, process, and people) results in several recommendations for “best practices” in systems development.
Human CCAAT/Enhancer-binding Protein β Gene Expression Is Activated by Endoplasmic Reticulum Stress through an Unfolded Protein Response Element Downstream of the Protein Coding Sequence *

CCAAT/enhancer-binding protein β (C/EBPβ) is a member of the bZIP family of transcription factors that contribute to the regulation of a wide range of important cellular processes. The data in the present study document that transcription from the human C/EBPβ gene is induced in response to endoplasmic reticulum stress, such as glucose deprivation, or treatment of cells with tunicamycin or thapsigargin. Transient transfection of C/EBPβ genomic fragments linked to a luciferase reporter gene demonstrated that the C/EBPβ promoter plays no major regulatory role. Instead, by deletion analysis it was discovered that a 46-bp region, located at a genomic site that corresponds to the 3′-untranslated region of the C/EBPβ mRNA, harbored an element that was required for the stress response. Mutagenesis demonstrated that a cis-regulatory element located at nt +1614–1621 (5′-TGACGCAA-3′) is responsible for activation of the C/EBPβ gene. Electrophoresis mobility shift analysis revealed that proteins are bound to this element and that the amount of binding is increased following glucose deprivation. This element is homologous to a previously reported mammalian unfolded protein response element that binds XBP-1. Consistent with those data, overexpression of XBP-1 caused an increase in transcription that was mediated by the C/EBPβ mammalian unfolded protein response element.
Amelogenin "nanorods" formation during proteolysis by Mmp-20.

Abstract Amelogenin is cleaved by enamelysin (Mmp-20) soon after its secretion, and the cleavage products accumulate in specific locations during enamel formation, suggesting that parent amelogenin proteolysis is necessary for activating its functions. To investigate the precise roles of Mmp-20 and its influence on the assembly of amelogenin, an in vitro enzymatic digestion process mimicking the initial stages of amelogenin proteolysis was investigated at near-physiological conditions using recombinant porcine amelogenin (rP172) and enamelysin. Hierarchically organized nanorod structures formed during different digestion stages were detected by TEM. At the earliest stage, uniformly dispersed parent amelogenin spherical particles, mixed with some darker stained smaller spheres, and accompanying elongated chain-like nanostructures were observed. Cylindrical nanorods, which appeared to be the result of tight assembly of thin subunit cylindrical discs with thicknesses ranging from ∼2.5 to ∼6.0 nm, were formed after an hour of proteolysis. These subunit building blocks stacked to form nanorods with maximum length of ∼100 nm. With the production of more cleavage products, additional morphologies spontaneously evolved from the cylindrical nanorods. Larger ball-like aggregates ultimately formed at the end of proteolysis. The uniform spherical particles, nanorods, morphological patterns evolved from nanorods, and globular aggregated microstructures were successively formed by means of co-assembly of amelogenin and its cleavage products during a comparatively slow proteolysis process. We propose that, following the C-terminal cleavage of amelogenin, co-assembly with its fragments leads to formation of nanorod structures whose properties eventually dictate the super-structural organization of enamel matrix, controlling the elongated growth of enamel apatite crystals.
Use of phosphates in patients with calcareous renal calculi.

The effectiveness of orthophosphate administration in reducing the urinary calcium of hypercalciuric patients was first demonstrated by Albright et al [1]. Subsequently, Cordonnier and Talbot [2] suggested that the high incidence of renal calculi in immobilized patients might be decreased if their hypercalciuria was lessened by the use of sodium acid phosphate. Interestingly, in their immobilized patients, these investigators found that sodium acid phosphate regularly caused a reduction in urinary calcium, whereas in ambulatory normocalciuric subjects, it had been noted previously that orthophosphates did not induce any consistent change in urinary calcium [3].
The Division of Political Labor Between Mothers and Fathers

Primary groups are of undoubted importance in shaping and mediating the political behavior of individuals. Of all primary groups, the nuclear family is of special significance. A person's family of origin and family of procreation serve as important socialization agents and reference groups throughout the life cycle. As with most groups there is a division of labor within the family. This is most obvious with respect to parental versus offspring roles. Although exceptions come to mind, parents are typically the major political actors in the family. By the same token parents usually introduce their children into the political world rather than vice versa. Less obvious, perhaps, is the possibility that some division of labor also exists between marital partners. Some tasks may be shared rather equally while others may be performed much more by one partner than the other. Such a division would condition the political behavior of adults; it would also condition the socialization of children. This article looks at the degree to which political tasks are divided within couples, the relative superiority of one partner over the other, and the contingencies affecting differential behavior.
Preservation of Intrahepatic Hepatitis C Virus (HCV)-Specific CD4+ T Cell Responses despite Global Loss of CD4+ T Cells in HCV/HIV Coinfection

Background. Human immunodeficiency virus (HIV) coinfection and low peripheral blood CD4 + T cell counts are associated with increased hepatitis C liver disease.Methods. Hepatitis C virus (HCV)-specific CD4 + T cell responses were assessed using interferon (IFN)-γ enzyme-linked immunospot assays on peripheral blood mononuclear cells and expanded liver lymphocytes from HCV-monoinfected and HCV/HIV-coinfected subjects. Cell frequencies were determined using flow cytometry.Results. HIV coinfection was associated with decreased CD4 + T cell percentages in both peripheral blood (21% vs. 48%; P < .0001) and liver (15% vs. 36%; P < .0001) and with reduced responsiveness of peripheral CD4 + T cells to HCV antigens compared with HCV monoinfection (22% vs. 45%; P = .021). However, intrahepatic HCV-specific responses were maintained in HCV/HIV coinfection, compared with HCV monoinfection (38% vs. 32%; P = .7). Notably, the presence of HCV-specific responses was not related to the frequency of liver CD4 + T cells (P = .4). Circulating and liver CD4 + T cell percentages were correlated (r = 0.58; P < .0001). Circulating percentages were also inversely associated with liver fibrosis stage among HCV/HIV-coinfected subjects (P = .029). Neither hepatic CD4 + T cell percentages nor HCV-specific IFN-γ responses in the liver or periphery predicted stage.Conclusions. Despite decreases in peripheral blood HCV-specific CD4 + T cell responses and intrahepatic CD4 + T cell percentages, intrahepatic HCV-specific CD4 + IFN-γ responses were preserved in HCV/HIV coinfection.
Influence of temperature and hydroxyl concentration on incipient soot formation in premixed flames

Critical equivalence ratios phi(c) have been measured as a function of temperature (1600-1880 K) for premixed flames at atmospheric pressure. The five fuels studied are methane, ethane, propane, ethylene, and acetylene. The flames were stabilized on a flat flame burner and the temperatures were measured using sodium D-line reversal. A linear relationship is found between In phi(c) and 1/T for each fuel. Based on a global kinetic model in which soot precursors are formed by fuel pyrolysis and oxidized by OH, a predictive correlation has been developed which shows the influence of temperature, OH concentration, and C/H ratio on sooting tendency. This correlation describes all of the measured phi(c) versus temperature data, suggesting that the overall mechanism of soot formation is similar among aliphatic fuels.
Effect of cyclodextrins on the physicochemical properties of chlorophyll a in aqueous solution.

The interactions between chlorophyll a and two β-cyclodextrins, that have the same cavity size but different substituents, were studied in aqueous solutions. These supramolecular host−guest complexes were examined by a combination of UV/vis absorption, circular dichroism, NMR, and steady-state and time-resolved fluorescence measurements. The results indicate that all cyclodextrins solubilize the pigment mainly in monomeric form in water. The pigment forms 1:1 complexes with the heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin and 1:2 complexes with the hydroxypropyl-β-cyclodextrin. In such complexes the methyl groups of the cyclodextrin inner cavity are involved in the interaction with the pigment as evidenced by NMR measurements. We also measured the luminescence of singlet oxygen photosensitized by chlorophyll a in the inclusion complexes.
Mycobacterial variations as influenced by phage and other genomic factors.

A photochromogen,M. kansasii, produces cleared areas when plated on heavier inoculations of human, H37Rv, strain. No phage could be demonstrated. From an area spread with H37Rv and theM. kansasii was isolated a chromogenic rough type colony the organism of which produced lesions in guinea pigs. It is suggested that a cross or recombination may have occurred to produce this variant type.
PROCESSING PARAMETER EFFECTS ON TEXTURAL CHARACTERISTICS OF REDUCED‐FAT PORK SAUSAGE

The objective of this study was to evaluate the effects of fat (10, 20, and 30%, postrigor; 10 and 30% pre-rigor), rigor state, plate size (3 and 5 mm), and mixing time (2 and 5 min) on cooking loss and instrumental texture characteristics of reduced-fat pork sausage. High-fat products exhibited greater cook loss and lower breaking force than low-fat products. Rigor state of raw materials had no effect on the characteristics evaluated. Increasing plate size and mixing time increased initial force required to compress a 2.5 cm core to 20% of its original height but had no effect on other characteristics. Reduction of fat content can be accomplished without addition of nonmeat ingredients by limiting plate size to 3 mm and mixing time to 2 min.
Purification, recovery, and laser-driven fluorination of silicon from dissolved and particulate silica for the measurement of natural stable isotope abundances.

A procedure for the purification, recovery, and determination of isotopic abundances of silicon from biogenic and lithogenic particulate matter and dissolved silicic acid is reported. Purification involves the reaction of acid molybdate with dissolved silicon in natural waters or that produced by the dissolution of particulate silica by hydrofluoric acid. The resulting silicomolybdic acid is then quantitatively precipitated by reaction with triethylamine hydrochloride. The silicon is recovered as silicon dioxide through stepwise combustion of the dried precipitate. Fluorination of the product for isotopic analysis is accomplished by laser heating under pure fluorine generated by the decomposition of a fluorine-based salt. The resulting silicon tetrafluoride is separated from hydrogen fluoride and other fluorination byproducts cryogenically using a variable-temperature cold trap. Yields for silicon recovery are 99.9% for precipitation and greater than 95% for the purification/fluorination procedure. Reprod...
Fungal degradation of organophosphorous insecticides

Organophosphorous insecticides are used extensively in agriculture. As a group, they are easily degraded by bacteria in the environment. However, a number of them have half-lives of several months. Little is known about their biodegradation by fungi. We showed thatPhanerochaete chrysosporium mineralized chlorpyrifos, fonofos, and terbufos (27.5, 12.2, and 26.6%, respectively) during an 18-d incubation in nutrient nitrogen-limited cultures. Results demonstrated that the chlorinated pyridinyl ring of chlorpyrifos and the phenyl ring of fonofos undergo cleavage during biodegradation by the fungus. The usefulness ofP. chrysosporium for bioremediation is discussed.
Language Production: Electroencephalographic Localization in the Normal Human Brain

Slow negative potentials, which are at a maximum over Broca's area in the left hemisphere, were recorded when normnal subjects spontaneously produced polysyllabic words. Bilaterally symmetrical potentials were seen with analogous, nonspeech control gestures. These potentials began up to 1 second before word or gesture articulation. These results are the first demonstration of localization of language production in normal human brain.
Balanced Simultaneous Confidence Sets

Abstract Suppose that T(θ) = {Tu (θ)} is a family of parametric functions indexed by the variable u. For each u, an approximate confidence set Cn,u for Tu (θ) may be obtained by referring a function of Tu (θ) and the sample to an estimated quantile dn,u of that function's sampling distribution. This approach is sometimes called the pivotal method for constructing a confidence set, even when it is not based on a true pivot. A simultaneous confidence set Cn for T(θ) is then obtained by simultaneously asserting the individual confidence sets {Cn,u }. The problem is to choose the critical values for the {Cn,u } in such a way that the overall coverage probability of Cn is correct and the coverage probabilities of the individual confidence sets {Cn,u } are equal. The second property is termed balance. It means that the simultaneous confidence set Cn treats each constituent confidence statement Cn,u fairly. Aside from a few special cases, the problem just described is too difficult for analytical approaches, whe...
Melting and mantle flow beneath a mid-ocean spreading center

Abstract A series of numerical experiments on mantle flow, melt generation, and melt migration beneath mid-ocean ridges is reported. In these experiments, flow in the mantle is driven by the motion of the surface plates and melting-induced mantle density variations. Mantle densities are controlled by the proportions of minerals in the residual mantle and their Fe/Mg ratio. Flow due to thermal variations in density are ignored. Melting results from the decompression of the upwelling mantle beneath the ridge, and melt production rates are determined from variations in mantle temperature above a solidus that depends explicitly upon pressure, mantle mineralogy, and mantle oxide composition. Melt migration is driven by mantle pressure gradients and melt buoyancy forces. The mantle temperature is influenced by the latent heat of melting and the advection of heat due to flow of the melt and mantle. Experiments with solely plate driven flows illuminate the results of including these latter thermal effects. The latent heat of melting lowers mantle temperatures to the solidus wherever melting occurs and also has an influence on the distribution of melting. Advection of heat due to melt migration increases melting rates up the melting column. For low mantle viscosities (10 18 Pa s) the latter effect is minor as melt rises essentially vertically. The thermal effect of the melt, however, will become more important as melting rates increase and if melt is focused into a narrow region. At slow spreading rates (1 cm yr −1 ), depletion-driven mantle flow markedly increases crustal thicknesses as melting rates increase to match the enhanced advection of mantle heat. This additional flow also causes the melting region to become narrower but is an insufficient mechanism for focusing melt to the ridge axis. The rapid extraction of the melt phase from the mantle results in an enhanced upwelling beneath the ridge which in turn leads to higher melt production rates and greater crustal thicknesses. Solidification of the melt phase at its liquidus results in melt freezing rates of order ten times greater than average melt production rates. High freezing rates are the result of high vertical temperature gradients in the cool oceanic lithosphere where the freezing occurs. The release of latent heat upon solidification has a negligible effect upon melting rates within the melting regime. Buoyancy forces resulting from the presence of an interstitial melt phase can result in a significant narrowing of the mantle upwelling beneath the ridge and also the width of the melt regime. The importance of melt buoyancy forces in shaping mantle flow depends on their magnitude relative to buoyancy forces resulting from density changes in the solid mantle.
Reactivity of Group 4 Metal Alkyl and Metallacyclic Compounds Supported by Aryloxide Ligands Toward Organic Isocyanides

The reactivity of the dimethyl compound [Ti(OC6H3Ph2-2,6)2Me2] (1) and titanabicyclic compounds [(ArO)2Ti(CH2CH(C4H8)CHCH2)] (6, 7) (formed by trans-coupling of 1,7-octadiene) toward organic isocyanides has been investigated. Dimethyl 1 reacts with 1 equiv of 2,6-dimethylphenylisocyanide (xyNC) to produce a cyclometalated product [Ti(OC6H3Ph2-2,6)(OC6H3Ph-η1-C6H4){N(xy)CHMe2}] (2), which was structurally characterized. Compound 2 is believed to arise via CH bond activation within an intermediate η2-imine (azatitanacyclopropane) formed by transfer of both methyl groups to the isocyanide. With an excess of xyNC, 1 produces an intermediate bis(η2-iminoacyl) 4, which slowly converts to the enediamide [Ti(OC6H3Ph2-2,6)2{N(xy)CMeCMeN(xy)}] (5). The solid-state structure of 5 shows the presence of a folded diazatitanacyclopent-3-ene ring formed by intramolecular coupling of the two iminoacyl groups. Titanabicyclic compounds 6 and 7 react with ButNC and xyNC respectively to generate products 8 and 9, which both c...
Using liquid-crystal devices as input and filter SLMs

It is well known that real-time pattern recognition and tracking can be accomplished with optical correlation. The performance of a particular correlator depends mainly on the capability and availability of real-time spatial light modulators. Recently, twisted nematic liquid crystal (TNLC) devices have been used as spatial light modulators. To date, most of the correlator systems use these liquid crystal devices in either a joint transform correlator or as the input spatial light modulator in a Vander Lugt correlator system. This paper discusses the design considerations of a gray-scale converging beam correlator system using liquid crystal devices at both the input and the filter planes. The optical properties of twisted nematic liquid crystals pertaining to their use as a SLM are discussed. To date, all of the pixelated liquid crystal devices are addressed by video signal. A gray scale video addressing scheme is presented. In addition, the design of a real time converging beam correlator utilizing liquid crystal devices from an Epson Video projector is presented along with results that characterize its performance.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Factors Contributing to Hwabyung Symptoms among Korean Immigrants

This article reports on findings of a study examining the factors contributing to hwabyung symptoms among Korean immigrants in the United States. Data collected from an anonymous, voluntary survey of 242 adult Korean immigrants residing in the New England metropolitan area were employed for a statistical analysis. The findings highlight the importance of coping resources, both social support and self-esteem, in explaining hwabyung symptoms. Also, the findings suggest that education attained in the United States, economic circumstance, and gender have significant impacts on hwabyung symptoms. Based on the findings, the implications for practice and future study are discussed.
Hydrologic hazards in the lower Drift River basin associated with the 1989–1990 eruptions of Redoubt Volcano, Alaska

Abstract The eruptions of Redoubt Volcano between December 14, 1989 and April 26, 1990 triggered flows of snow, ice, water, sediment, and debris that traveled down the Drift River as far as its mouth, about 40 km downstream. A major explosive eruption and dome collapse on January 2, 1990 produced the largest flow. The peak discharge of this flow at a location 22 km downstream from the volcano was estimated to be between 12,000 and 60,000 m 3 per second. The estimated peak discharge of this event is more than 100 times larger than the 100-year meteorologically generated flood estimated for the Drift River. Pyroclastic flows and hot meltwater scoured the surface of Drift Glacier on the north flank of the volcano and were transformed into multipulsed, multiphased debris flows. Several other significant flows were generated by eruptions during this period: the two largest of these occurred on December 15, 1989 and February 15, 1990. Subsequent channel changes threatened the Drift River Oil Terminal built on an alluvial fan near the mouth of the Drift River.
Electron Microscopic Observations on Mitochondria of Rat Testes Fixed in Potassium Permanganate

A morphological investigation of mitochondria within the seminal epithelial cells of rat testes fixed in potassium permanganate reveals differences in electron opacity between the internal mitochondrial membranes of spermatogenic cells and those of Sertoli cells. Some interpretations of the apparent density differences are briefly discussed. It is concluded that the different effects of permanganate fixation upon the mitochondria of these cell types may reflect a significant structural difference between them.
A note on fitting one-compartment models: Non-linear least squares versus linear least squares using transformed data

Drug concentrations in one-compartment systems are frequently modeled using a single exponential function. Two methods of estimation are commonly used for determining the parameters of such a model. In the first method, non-linear least-squares regression is used to calculate the parameters. In the second method, the data are first transformed by a logarithmic function, and then the log-concentration data are fit using linear least-squares regression. The assumptions for fitting these models are discussed with special emphasis on which data points are most influential in determining parameter values. The similarities between fitting a linear regression model to the log-concentration data and fitting a weighted regression model to the original data are noted. An example is presented that illustrates the differences in fitting a model to the log-transformed data versus fitting unweighted and weighted models to the original-scale data.
Opiate vs non-opiate eootshock induced analgesia (FSIA): Descending and intraspinal components

Abstract Opiate and non-opiate footshock induced analgesia (FSIA) can be differentially elicited dependent upon the body region shocked. As measured by the spinally-mediated tail flick test, hind paw shock produces non-opiate analgesia whereas front paw shock produces opiate analgesia. The present series of experiments utilized cord lesions and transections to identify descending and intraspinal pathways mediating front paw and hind paw FSIA. The results of these studies indicate that front paw shock leads to activation of supraspinal sites which mediate analgeshi via descending pathways lying solely within the dorsolateral funiculus (DLF) of the spinal cord; direct intraspinal pathways are not involved. Hind paw FSIA is also mediated by a descending DLF pathway but is unlike front paw FSIA in that it involves intraspinal pathways as well. This work provides further parallels between the analgesias produced by morphine, electrical brain stimulation and environmental stimuli.
The crystal and molecular structure of 3,7‐dicyano‐3,5,7‐triaza‐1‐phosphabicyclo[3.3.1]nonane

The crystal and molecular structure of the title compound has been determined by a single crystal x-ray diffraction study using counter-data. The compound crystallizes in the monoclinic space group, P21/c, with a = 8.657 ± .001A, b = 10.513 ± .001A, c = 10.378 ± .001A, β = 99.68 ± .01° for Z = 4. The structure was solved by the symbolic addition procedure and refined by block-diagonal least-squares to R = 0.052 for 1479 statistically significant reflections. The geometry of the bicyclic ring system is discussed.
Hydrogen-rich gas production from oxygen pressurized gasification of biomass using a Fe–Cr Water Gas Shift catalyst

Abstract In this paper the catalytic activity of a Fe–Cr WGS catalyst is evaluated in terms of CO conversion and H 2 production. The experimental study has been carried out under realistic conditions typical of oxygen pressurized gasification of biomass. The influence of temperature, excess steam, feed gas composition and space velocity on the activity and selectivity of the catalyst for the WGS reaction is investigated. The experimental work was carried out in a micro reactor testing unit using synthetic gas feed mixtures. Despite the high CO content in the feed gas (44–60% dry basis) the catalyst has shown very good performance at intermediate temperatures 350–450 °C, providing hydrogen content increases in the exit gas in the range of 10–17% (dry basis) and CO concentration at the reactor outlet lower than 3% v/v. Best performance operating conditions and the suitability of the catalyst to be incorporated in a palladium membrane reactor is discussed in this article.
The effect of EDTA and trisodium phosphate, alone and in combination with nisin, on the growth of Arcobacter butzleri in culture

Arcobacter butzleri is a common contaminant of foods of animal origin and there is increasing evidence linking the organism to human illness. This study investigated the effectiveness of ethylene diamine tetra-acetic acid (EDTA) and trisodium phosphate (TSP) alone and in combination with nisin, on the growth of A. butzleri in culture. At 1 mM, 5 mM, 10 mM and 20 mM, EDTA inhibited growth, both alone and combined with 500 IU ml−1nisin, but only at 20 mM did the addition of nisin produce a statistically significant difference compared with EDTA alone (4·3 log10and 5·6 log10reduction respectively). Short-term simultaneous exposure with EDTA and 500 IU ml−1nisin was more effective than sequential treatment on both logarithmically growing and stationary phase cells. Growth of A. butzleri was inhibited by 0·5 mM TSP with simultaneous treatment being more effective than sequential treatment. After 10 min simultaneous treatment, only at 40 mM TSP (but not at lower concentrations) was there a statistically significant difference between TSP treatment alone and TSP plus 500 IU ml−1nisin (5·2 log10compared with 7·7 log10reduction). Thirty-minute treatment with 20 mM EDTA or 10 min with 10% TSP at 4°C, followed by incubation in the presence of 500 IU ml−1nisin, resulted in no viable cells being recovered after 24 h (>99·9% cell kill) indicating that a multiple hurdle approach is the most effective method of reducing growth and survival of A. butzleri in culture.
Morphological changes of the pyramidal cell nucleolus and nucleus in hamster frontal cortex during develoment and aging

Abstract The development and aging of the nucleolus and nucleus in layer V pyramidal cells in the hamster cerebrum were studied by light and electron microscopy. The nucleoli appeared in the newborn as occasional fibrillar masses adjacent to peripherally placed bodies of chromatin. By maturity, a single, generally central, nucleolus proper with nucleolus-associated chromatin was present. Nucleolar microbodies were observed at 10, 15, 20 and 480 days, but not in the newborn, 5- or 90-day animal. An intranucleolar body was not observed at the electron-microscopy level in these pyramidal cell nucleoli at any age in this series, in contrast to the situation in large motor neurons of the facial nucleus. The nucleus progressed from an irregular shape at birth to an oval shape at maturity. At 10 days, incipient invaginations of the nuclear membrane appeared; these subsequently increased in depth and frequency in the adult. The above changes,particularly in the nucleoli, are correlated in time with changes involving the endoplasmic reticulum. The correlations may indicate different periods of metabolic activity in the hamster pyramidal neurons. Four such periods can be differentiated on the basis of cytomorphic changes which may be correlated to reported development of function. The sequence of these changes, peculiar to the developing and aging hamster pyramidal neuron, differs from that seen in large spinal and cranial motor neurons. It appears that some features of nuclear immaturity, which are lost in larger neuronal types, are retained in the adult pyramidal neuron.
Petrologic Controls of Reservoir Properties of Mid-Continent Pennsylvanian Sandstones: ABSTRACT

Petrographic analyses of Middle Pennsylvanian (Desmoinesian) Cherokee Group sandstones in the Mid-Continent show that effective liquid porosities, liquid permeabilities, and pore-size distributions are controlled by sedimentologically influenced petrologic parameters and subsequent diagenetic alterations. Deltaic complexes contain two distinct sandstone-bearing lithologies: (1) subarkosic-quartzarenitic channel sandstones, and (2) sublitharenitic sandstones interstratified with shales representing overbank and interdistributary deposits. The sandstones in these two settings underwent different diagenetic histories, which enhanced original differences in their reservoir properties. Overbank deposits commonly contain soft, argillaceous rock fragments which underwent plastic deformation during compaction, causing the clogging of some pore-throats and pores. In addition, extensive silica cementation, perhaps due to diagenetic clay mineral conversions, caused further destruction of primary pores. In channel sandstones, porosity reduction was less extensive and apparently proceeded at a slower rate. Chlorite coatings on many grains prevented destruction of original pore spaces by inhibiting further silica cementation. Individual sandstone bodies with abundant coatings fall within a porosity range of 20 to 25%, whereas bodies with uncoated grains rarely exceed 18%. Permeabilities in clay-coated reservoir rocks fall within a 100 to 200 md range, whereas uncoated or spa sely coated rocks are in the 1 to 30 md range. The diagenetic histories of these rocks are further complicated by the development of secondary porosity caused mainly by dissolution of the feldspathic grains and carbonate cements. End_of_Article - Last_Page 644------------
Consequences of hydrogen bonding on molecular organization and charge transport in molecular organic photovoltaic materials

Reported is a systematic molecular structure–property relationship study to evaluate the consequences of dedicated H-bonding interactions between molecular electron donors on molecular assembly, absorption, charge collection, and performance in small-molecule bulk heterojunction organic photovoltaic devices. Three families of branched quaterthiophene donor chromophores have been synthesized with members that share nearly identical electronic and optical properties in the molecularly dispersed state but are either capable or incapable of self-association by hydrogen bonding (H-bonding). Phthalhydrazide-functionalized quaterthiophenes are H-bond “active” and show signatures of H-bond promoted assembly in solution (by 1H NMR) and in both neat and blended (with C60) films (by IR). Compared to control compounds with H-bonding “turned off”, the H-bonded derivatives show red-shifted thin film absorption (neat and as blends with C60), different colors as bulk solids, and increased decomposition and melt temperatures. Photovoltaic devices made from blends of H-bonded donor molecules with C60 as the electron acceptor show improved charge collection length and external quantum efficiency resulting in a more than two-fold enhancement in power conversion efficiency relative to non-H-bonding controls, from 0.49% to 1.04%. We anticipate this approach could be generalized to include other donor chromophores with lower optical gap to harvest more longer-wavelength photons and achieve higher power conversion efficiencies.
Crystallization and preliminary diffraction analysis of the HincII restriction endonuclease-DNA complex.

Crystals of the 60 kDa dimeric HincII restriction enzyme bound to a 12 base-pair dyad-symmetric duplex DNA carrying the specific 5′-­GTCGAC recognition site have been obtained. Crystals grew by hanging-drop vapor diffusion from solutions containing polyethylene glycol 4000 as precipitating agent. The rod-shaped crystals belong to space group I222 (or I212121), with unit-cell dimensions a = 66.9, b = 176.7, c = 256.0 A. There are most likely to be two dimeric complexes in the asymmetric unit. A complete native data set has been collected from a high-energy synchrotron source to a resolution of 2.5 A at 100 K, with an Rmerge of 4.8%.
U.S. Business and the Transfer of Intermediate Technology: Agricultural Equipment and the Developing Nations

Survey of U.S. firms manufacturing “intermediate” agricultural technology and U.S. aid organizations operating abroad suggests possibilities for expansion in developing nations. Although a need for technology transfer has been perceived, objections to the use of business must be overcome if there is to be a meaningful transfer of technology.
Extraction Of Soil And Vegetation Parameters From High Resolution Bi-directional Reflectance Spectra

High spectral resolution reflectance spectra were collected over a semi-desert grassland at both dry and wet season periods. Spectral reflectance measurements were made from several viewing angles at both low and high solar zenith angles. A mixture model was used to separate and extract green vegetation from dry/dead vegetation and soil. The extracted vegetation signal varied greatly with view and sun angle variations such that off-nadir viewing and illuminating angles resulted in the highest vegetation loadings. These variations were normalized with cosine functions for both sun and view angle. These results offer a methodology for standardizing multi-temporal and multi-angular satellite measurements of vegetation activity.
Cationic Diffusion in Clay Minerals:II. Orientation Effects*

The effect of orientation of vermiculite particles on the diffusion of Na ion was measured by a tracer technique. The diffusion measurements were made on pellets prepared by pressing freezedried vermiculite in a cylindrical die and the diffusion coefficient evaluated by a thin-film boundary condition of Fick’s law. Because flakes of vermiculite were highly oriented under the pressing force, it was possible to prepare different angles of specimen orientation with respect to the surface where diffusion was initiated. Mathematical relationships of orientation angle, axial ratio of the platelets, and apparent diffusion coefficient were developed. The experimental results on the diffusion of Na ion in K-vermiculite of clay size gave apparent diffusion coefficients of 2·21 × 107cm2 sec−1 when the diffusion flux was parallel with the clay platelets and 0·45 × 10−7 cm2 sec “1 when the flux was perpendicular to the clay platelets. For the diffusion of Na ion into Na-vermiculite, apparent diffusion coefficients were obtained of 1·18 × 10−8cm2sec−1 when the diffusion flux was parallel with the clay platelets, and 0·18 × 10−8 cm2 sec−1 when the flux was perpendicular to the platelets. For K-vermiculite, the change in apparent diffusion coefficient is a simple one of particle geometry. The Na-vermiculite system exhibited more complicated behavior.