cssi/SciSciGPT-SciSciNet huggingface dataset:
Molybdenum carbonitride deposited by plasma atomic layer deposition as a Schottky contact to gallium nitride

Molybdenum carbonitride films prepared by plasma enhanced atomic layer deposition were studied for use as Schottky contacts to n-type gallium nitride. Deposited using bis(tertbutylimino)bis(dimethylamino)molybdenum and a remote plasma N2/H2 plasma, the diodes capped with Ti/Au displayed excellent rectifying behavior with a barrier height of 0.87 ± 0.01 eV and an ideality factor of 1.02 ± 0.01 after annealing at 600 °C in N2. These characteristics surpass those of pure metal nitride Schottky diodes, possibly due to work function engineering due to the incorporation of C and use of a remote plasma to avoid process-induced defects. According to x-ray photoelectron spectroscopy and energy-dispersive x-ray spectroscopy, the film composition is approximately MoC0.3N0.7. Grazing incidence x-ray diffraction and plan-view transmission electron microscopy selected area electron diffraction are consistent with a rock salt structure with a lattice parameter of 0.42 nm.
Benzonaphthothiophene migration tracer: Selective separation and comparison with nitrogen tracers

Abstract Benzonaphthothiophene (BNT) ratio (benzonaphtho[2,1-d]thiophene/benzonaphtho[1,2-d]thiophene) for five oil fields in Saudi Arabia, was measured and integrated with benzocarbazole ratio (BCR, benzo[a]carbazole/benzo[c]carbazole) and other geochemical data to track migration pathways and reduce charge risk. To improve analytical resolution, the sulfur-containing heterocycles were separated from the aromatic hydrocarbons using palladium(II)-bonded silica column prior to gas chromatography–mass spectrometry. The API gravity varies from 34.6° in the northernmost deepest field A to 14.7° in field E located 5000 ft (1524 m) shallower and 150 km to the south. This southward-shallowing trend is accompanied by a drop in the BNT ratio from 5.49 (field A) to 1.89 (field E). A common source kitchen and a narrow maturity range (0.78–0.84% calculated vitrinite reflectance), together with the lack of any evidence for biodegradation, collectively suggest that the observed fluid property variations in this petroleum system are controlled mainly by geochromatographic fractionation during migration. This is further attested by similarly decreasing BCR from 1.09 to 0.24, in agreement with southward migration. In comparison with the BCR, the BNT ratio shows wider variations with depth and relative migration distances, attesting to its value in tracking migration and reducing charge risk, especially in fluids that lack carbazole derivatives.
Social Psychology and Mental Retardation

Publisher Summary This chapter discusses social psychology aspects of mental retardation. The chapter offers an interpretation of retardation that stresses three variables: the genetic endowment of the population; the ability level of the population; and the demands of the society. Mental retardation is seen as a social problem that is destined to increase, as the accelerating demands of society outdistance the ability of an ever-increasing percentage of the population. The recommended solution is the institution of one or more of the several possible “eugenics” programs. In recommending such programs, it is emphasized that retardation (and genius) does run in families and that a phenotypically based program of birth control would, therefore, work irrespective of whether the familial nature of the conditions is based on genetic or cultural factors or both. The first section of this chapter discusses the extent to which a social psychology of mental retardation does or does not exist. The second section treats retardation as a social problem that may be alleviated by a eugenics program. The third section discusses the retardate's social success, his vocational success, his self-concept, his image in the eyes of the layman, and his relation with his family.
‘FOR THE BETTER HUMILIATION OF THE PEOPLE’: PUBLIC DAYS OF FASTING AND THANKSGIVING DURING THE ENGLISH REVOLUTION

(1992). ‘FOR THE BETTER HUMILIATION OF THE PEOPLE’: PUBLIC DAYS OF FASTING AND THANKSGIVING DURING THE ENGLISH REVOLUTION. The Seventeenth Century: Vol. 7, No. 2, pp. 129-149.
Population and ecosystem theory in ecological risk assessment

Assessments of ecological risks associated with toxic contaminant releases necessarily involve extrapolation from observed responses of simplified laboratory systems to predicted responses of complex natural systems. In this paper we evaluate the utility of population and ecosystem theory for making these extrapolations, based on: (1) the success of the theory when applied to other environmental assessment and resource management problems, and (2) the degree of scientific consensus concerning the appropriate approaches to modeling populations and ecosystems. The applications we review include fisheries management, water-quality assessment and management, and power-plant-impact assessment. We conclude that neither population nor ecosystem theory can now provide models that accurately predict the long-term ecological consequences of toxic contaminant releases. However, we show how short-term effects of toxic contaminants on fish populations can be projected by use of models employed in fisheries management. Further, we show how ecosystem theory can, in spite of its relative immaturity, make immediate contributions to understanding the qualitative responses of complex ecological systems to toxic contaminants.
Fuzzy Temporal Segmentation and Probabilistic Recognition of Continuous Human Daily Activities

Understanding human activities is an essential capability for intelligent robots to help people in a variety of applications. Humans perform activities in a continuous fashion, and transitions between temporally adjacent activities are gradual. Our Fuzzy Segmentation and Recognition (FuzzySR) algorithm explicitly reasons about gradual transitions between continuous human activities. Our objective is to simultaneously segment a given video into a sequence of events and recognize the activity contained in each event. The algorithm uniformly segments the video into a sequence of nonoverlapping blocks, each lasting a short period of time. Then, a multivariable time series is formed by concatenating block-level human activity summaries that are computed using topic models over local spatiotemporal features extracted from each block. Through encoding an event as a fuzzy set with fuzzy boundaries to represent gradual transitions, our approach is capable of segmenting the continuous visual data into a sequence of fuzzy events. By incorporating all block summaries contained in an event, our algorithm determines the activity label for each event. To evaluate performance, we conduct experiments using six datasets. Our algorithm shows promising continuous activity segmentation results on these datasets and obtains the event-level activity recognition precision of 42.6%, 60.4%, 65.2%, and 78.9% on the Hollywood-2, CAD-60, ACT $4^2$ , and UTK-CAP datasets, respectively.
Predicting short-period, wind-wave-generated seismic noise in coastal regions

Substantial effort has recently been made to predict seismic energy caused by ocean waves in the 4–10 s period range. However, little work has been devoted to predict shorter period seismic waves recorded in coastal regions. Here we present an analytical framework that relates the signature of seismic noise recorded at 0.6–2 s periods (0.5–1.5 Hz frequencies) in coastal regions with deep-ocean wave properties. Constraints on key model parameters such as seismic attenuation and ocean wave directionality are provided by jointly analyzing ocean-floor acoustic noise and seismic noise measurements. We show that 0.6–2 s seismic noise can be consistently predicted over the entire year. The seismic noise recorded in this period range is mostly caused by local wind-waves, i.e. by wind-waves occurring within about 2000 km of the seismic station. Our analysis also shows that the fraction of ocean waves traveling in nearly opposite directions is orders of magnitude smaller than previously suggested for wind-waves, does not depend strongly on wind speed as previously proposed, and instead may depend weakly on the heterogeneity of the wind field. This study suggests that wind-wave conditions can be studied in detail from seismic observations, including under specific conditions such as in the presence of sea ice.
Numerical Modeling and Simulation of the Vehicle Cooling System for a Heavy Duty Series Hybrid Electric Vehicle

The cooling system of Series Hybrid Electric Vehicles (SHEVs) is more complicated than that of conventional vehicles due to additional components and various cooling requirements of different components. In this study, a numerical model of the cooling system for a SHEV is developed to investigate the thermal responses and power consumptions of the cooling system. The model is created for a virtual heavy duty tracked SHEV. The powertrain system of the vehicle is also modeled with Vehicle-Engine SIMulation (VESIM) previously developed by the Automotive Research Center at the University of Michigan. VESIM is used for the simulation of powertrain system behaviors under three severe driving conditions and during a realistic driving cycle. The output data from VESIM are fed into the cooling system simulation to provide the operating conditions of powertrain components. The cooling system model includes various component models for three main fluid circuits of coolant, cooling air, and engine oil. The model predicts the thermal responses of all cooling system components and the temperatures of the engine and electric components. Using the cooling system models, the thermal response and power consumption of the cooling system over a realistic driving cycle is estimated and the factors that affect the performance and the power consumption of the cooling system are identified.
Investigating the cell death mechanism(s) of 4-hydroxy-tamoxifen in glioblastoma (411.1)

Tamoxifen (TMX) is widely used as a chemotherapeutic agent in the treatment of estrogen receptor (ER)-positive breast cancer. Recent studies have demonstrated that TMX inhibits the growth of malign...
Evidence for Proteolytic Degradation of Histidinol Phosphate Phosphatase Specified by Nonsense Mutants of the hisB Gene of Salmonella typhimurium

The gene products from hisB nonsense mutants having histidinol phosphate phosphatase activity were isolated from Salmonella typhimurium. The enzyme from strain TR691 (hisB278 hisT1529 aroD5) was isolated in the presence of diisopropylfluorophosphate. Three electrophoretically separable forms were demonstrated, and all were shown to have a mol wt of approximately 38,000 and to consist of a single polypeptide chain. Previously, two forms of the phosphatase enzyme from this strain were isolated without diisopropylfluorophosphate and shown to have a different subunit composition. Strain TA387 (hisB2133 his 01242) was shown to have two electrophoretically separable phosphatases with a mol wt of about 52,000 and consisted of 17,000- to 19,000-mol wt polypeptide chains as evidenced by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The results could be explained by proteolytic cleavage of the primary gene product which can partially be prevented by the protease inhibitor. Strain TA387 phosphatase lost all activity in 8 M urea but could be renatured by dialysis. Gel filtration showed that it also regained its original molecular weight. The values of Km of histidinol phosphate and the competition inhibition constant for histidinol were determined. The addition of MnCl2 to the assay was shown to shift the optimal pH value to a lower pH value.
A report on the H‐bahai digital library

FOR HISTORIANS, SPECIALISTS IN RELIGION, AND SOCIAL SCIENTISTS INTERESTED in matters such as millenarianism or religion-state relations in Iran, the H-Bahai digital library (http://www2.h-net.msu.edu/-bahai/) is increasingly becoming a treasure trove of primary and secondary sources. Humanities and Social Sciences Online or H-Net (at http://www2.h-net.msu.edu/), a consortium of over 100 academic email discussion groups, is housed at Michigan State University and supported by that institution as well as the National Endowment for the Humanities. Among its many thriving lists are a handful that concentrate on Middle East Studies, including H-Turk and H-Levant. The only list so far with a specific Iran focus is H-Bahai, which focuses not only on the Bahali faith, but also on the Shaykhi and Babi movements and on thinkers and groups that intersect with these religious movements originating in the Qajar period. The discussions have often been lively, covering topics from the Constitutional Revolution in Iran to Shicite theology, and from Baha3i conversions in India and Malaysia to controversies of the Nicmatullahi Sufis. The discussion logs are available to academics at the main web page. The username is H-Bahai and the password is listpass. The list began in 1997 with about 70 subscribers and now has over two hundred members. Subscribers are required to have done graduate study in the social sciences or humanities. H-Net also provides the discussion lists with generous server space for web pages, but to date only H-Bahai and H-Africa have taken real advantage of the possibilities inherent in this medium. Although the vast majority of Iranians is Shicite Muslim, religious minorities have played a disproportionate cultural, social and economic role in modem Iran. Debates over the place of non-Muslims have also been crucial to its history. Shicism, a dynamic tradition, threw up a number of new religious traditions in the nineteenth century. Shaykhism synthesized religious motifs from esoteric Shicism, rationalism, and mysticism. Babism, a messianic or mahdist movement,
REFLECTIONS UPON UNIVERSITY RETIREMENT: WITH THANKS AND APOLOGIES TO JAMES JOYCE

This article examines (1) the elimination of mandatory retirement in American higher education, (2) research related to retirement decisions of university faculty, and (3) the author's thoughts and feelings before and following retirement from academia. An interior monologue, stream-of-consciousness method is used to reflect the author's movement into retirement following 35 years as a university professor. Reminiscence, life review, and a pilgrimage after 50 years to the author's childhood home, are incorporated in relation to the retirement process. The subsequent decision to embrace part-time university teaching is reflected within the interior monologue and in relation to recent retirement research.
Constraining Inflation with Cosmic Microwave Background Polarization

Observations of the polarization of the cosmic microwave backround (CMB) have the potential to place much tighter constraints on cosmological parameters than observations of the fluctuations in temperature alone. We discuss using CMB polarization to constrain parameters relevant for distinguishing among popular models for cosmological inflation, using the MAP and Planck satellite missions as example cases. Of particular interest is the ability to detect tiny contributions to the CMB anisotropy from tensor modes, which is fundamentally limited by cosmic variance in temperature-only observations. The ability to detect a tensor/scalar ratio r{approximately}0.01 would allow precision tests of interesting inflation models, and is possible with a modest increase in sensitivity over that planned for the Planck satellite or is potentially achievable by ground-based experiments. {copyright} {ital 1998} {ital The American Physical Society}
Ecomorphodynamic feedbacks and barrier island response to disturbance: Insights from the Virginia Barrier Islands, Mid-Atlantic Bight, USA

Abstract Ecomorphodynamic feedbacks play an important role in the susceptibility and response of barrier islands to disturbance by overwash. Dune-building grasses, like Ammophila breviligulata , can help to restore areas of high relief after overwash events (i.e., resist disturbance). If overwash recurs before dunes have reestablished, however, overwash-adapted “maintainer” species, like Spartina patens (upright variety), may preferentially survive. Maintainer species help to preserve low, flat topography, thereby increasing the likelihood of future overwash (i.e., reinforcing disturbance). Under frequent disturbance conditions, this positive feedback may lead to overwash persistence. We explore the potential influence of the maintainer feedback on two morphologically distinct barrier islands in the Virginia Coast Reserve (VCR), located in the Mid-Atlantic Bight of the U.S. East Coast. Combined topographic and vegetation surveys show that on Hog Island (high-relief, rotating), where dunes dominated by A. breviligulata are ubiquitous, overwash zones are currently limited in extent and related to beach width rather than dominance by S. patens . Historical aerial photos and stratigraphic evidence (ground-penetrating radar, cores) indicate that gradual recovery has taken place following overwash events on Hog Island, except where the beach is narrow and eroding. Conversely, on Metompkin Island (low-relief, transgressing), overwash is widespread and dominated by S. patens , particularly along the rapidly migrating northern half of the island, where shell armoring is also common. Overwash has generally been more prevalent and persistent here than on Hog Island. We present a new conceptual model of the response of barrier islands to disturbance incorporating ecological and physical processes. Our findings suggest that in barrier systems where both dune-building grasses and overwash-adapted maintainer species are common (like the VCR), the maintainer feedback is likely to be a more important dynamic on islands already susceptible to frequent disturbance because of physical factors. The maintainer feedback, therefore, has the potential to accelerate large-scale shifts from dune-dominated to overwash-dominated barrier morphologies as the effects of climate change (increased storm intensity, sea level rise) cause overwash to become more frequent.
Extent of ubiquinone reduction by succinate in electron transport particles from beef heart.

Abstract Addition of millimolar succinate to a buffered suspension of beef heart electron transport particles (ETP) treated with cyanide gives a greater decrease in optical absorption at 275 vs. 290 mμ, corresponding to ubiquinone (Q) reduction, than does addition of cyanide to succinate-treated particles prior to anaerobiosis. In the latter case, addition of millimolar succinate to the aerobic suspension rapidly reduces about one fourth of the Q, which level is maintained during steady state oxidation of succinate to fumarate. If the absorption decrease corresponding to this reduction, which is obscured by an increase due to fumarate, is accounted for, then the same total absorption decrease is observed for both cases of cyanide-induced and natural anaerobiosis; it corresponds to complete Q reduction. A pigment with a difference spectrum peak (reduced minus oxidized) at 313 mμ is also observed in these ETP; it interferes with Q determination if reference wavelengths longer than 290 mμ are used.
A non-aqueous microemulsion system of ethylene glycol, sodium dodecyl sulfate, toluene, and decanol

The microemulsion liquid in the system ethylene glycol, sodium dodecyl sulfate, decanol, and toluene was investigated by determination of solubility regions and of light scattering intensity.
Can rational choice guide us to correct de se beliefs

Significant controversy remains about what constitute correct self-locating beliefs in scenarios such as the Sleeping Beauty problem, with proponents on both the “halfer” and “thirder” sides. To attempt to settle the issue, one natural approach consists in creating decision variants of the problem, determining what actions the various candidate beliefs prescribe, and assessing whether these actions are reasonable when we step back. Dutch book arguments are a special case of this approach, but other Sleeping Beauty games have also been constructed to make similar points. Building on a recent article (Shaw, Synthese 190(3):491–508, 2013), I show that in general we should be wary of such arguments, because unintuitive actions may result for reasons that are unrelated to the beliefs. On the other hand, I show that, when we restrict our attention to additive games, then a thirder will necessarily maximize her ex ante expected payout, but a halfer in some cases will not (assuming causal decision theory). I conclude that this does not necessarily settle the issue and speculate about what might.
Model of hydrogenated amorphous silicon

Computer models of hydrogenated amorphous silicon have been constructed by adding hydrogen atoms to broken bonds in periodic random-network models of pure amorphous silicon. The atomic coordinates of 12 examples containing 10--13 at. % have been determined by minimizing a valence-force potential supplemented by a repulsion between H atoms and Si atoms other than those that are bonded to each other. Radial distribution functions and structure factors have been computed for three sets of force constants. The computed neutron scattering is in good agreement with recent diffraction data, and this is taken as support for the assumption that most of the hydrogen in this material is covalently bound to silicon atoms in a random network.
Ring-rotational defects in polyaniline

Abstract The effects of electron-lattice coupling via ring rotation on the electronic structure of leucoemeraldine base (LB) and its charged defects are investigated. We suggest that in LB and other phenyl-ring-containing polymers the charged defect states, particularly hole polarons, are associated with localized distortions of the ground state ring torsion angles toward a planar conformation, in contrast with the bond-alternation defects present in conducting polymers. The relevance of these defects to recent photoinduced optical experiments is discussed.
Improving cost estimation in market-based coordination of a distributed sensing task

While market-based approaches, such as TraderBots, have shown much promise for efficient coordination of multirobot teams, the cost estimation mechanism and its impact on solution efficiency has not been investigated. This paper provides a first analysis of the cost estimation process in the TraderBots approach applied to a distributed sensing task. In the presented implementation, path costs are estimated using the D* path planning algorithm with optimistic costing of unknown map cells. The reported results show increased team efficiency when cost estimates reflect different environmental and mission characteristics. Thus, this paper demonstrates that market-based approaches can improve team efficiency if cost estimates take into account environmental and mission characteristics. These findings encourage future research on applying learning techniques for online modification of cost estimation and in market-based coordination.
Uniform Microcrystals of Platinum and Gold

Theories describing bulk properties of solids are simplified by neglecting the presence of a boundary; i.e., one usually assumes a crystal of infinite size. There are situations, however, in which it is not permissible to neglect the effects that crystal boundaries have on electronic and vibrational properties. Order‐of‐magnitude calculations show that for most properties, particles must be less than 1000 A before size effects become manifest. To study physical properties which are crystal‐size dependent it is often desirable to have a sample containing many distinct particles of a well‐defined size distribution confined to a small volume. Hydrosols of platinum and gold have been prepared using various procedures in order to determine the optimum conditions required to produce a given crystal size with a uniform size distribution. Crystal size and morphology were analyzed by electron microscopy and electron diffraction. Uniform microcrystals were obtained with sizes ranging from 40 to 500 A. Methods for dialyzing and dehydrating the hydrosols are also discussed.
Formation of Ordered Cellular Structures in Suspension via Label-Free Negative Magnetophoresis

The creation of ordered cellular structures is important for tissue engineering research. Here, we present a novel strategy for the assembly of cells into linear arrangements by negative magnetophoresis using inert, cytocompatible magnetic nanoparticles. In this approach, magnetic nanoparticles dictate the cellular assembly without relying on cell binding or uptake. The linear cell structures are stable and can be further cultured without the magnetic field or nanoparticles, making this an attractive tool for tissue engineering.
Information Literacy as a Barrier

Aujourd'hui, la plupart d'entre nous disposent de trop d'informations. Les outils informatiques nous aident a gerer l'information, mais nous en apportent aussi davantage. Les changements dans les formats et l'organisation de l'information entrainent un besoin d'aide de la part des usagers. La culture de l'information est un concept qui a emerge pour decrire la tâche exigee. L'article propose une analyse de cette notion et expose les activites des bibliotheques en ce sens, en mettant l'accent sur les bibliotheques scientifiques et techniques
Usefulness of calcium scoring using electron beam computed tomography and noninvasive coronary angiography in patients with suspected coronary artery disease.

The aim of this study was to investigate the reliability of calcium scoring (CS) and electron beam computed tomographic angiography (EBCTA) as a noninvasive tool in the diagnosis of coronary artery disease (CAD): 93 consecutive patients (aged 59 ± 9 years) with symptoms suspicious for CAD underwent CS. In 87 of these subjects, an additional EBCTA investigation was performed. Using receiver-operating characteristic curve analysis, we determined a calcium score cut point providing an overall sensitivity of 80% and a specificity of 72% in detecting patients with CAD. For clinical purposes the use of cut points is difficult. We therefore determined score ranges providing >80% specificity (high score range) and >85% sensitivity (low score range) and determined the scores between these ranges as equivocal borderline scores. Calculated on a per-segment basis in assessable proximal and midcoronary segments, the sensitivity for detecting coronary stenoses >50% was 78%, and the specificity was 93%. Thus, 32 of 44 patients with significant CAD and 24 of 49 patients without CAD were correctly classified. The combination of CS and EBCTA predicted CAD in 77% (72 of 93) of patients. No or low calcium scores provided high specificity for ruling out CAD. The addition of EBCTA in those patients improved sensitivity. In patients with high calcium scores, accuracy of EBCTA was not significantly different from CS alone (72% vs 83%), whereas in patients with borderline scores it was significantly superior (80% vs 58%, p <0.03). Thus, the complementary use of CS and EBCTA appears beneficial, particularly in patients with borderline scores, and could improve sensitivity in the low score range. In the presence of high scores, no major diagnostic gain from an additional EBCTA versus CS alone could be observed.
Sensory innervation of the rat kidney and ureter as revealed by the anterograde transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) from dorsal root ganglia.

The sensory innervation of the rat kidney and ureter was investigated in wholemount preparations and sectioned materials by labeling the afferent nerve fibers with wheat germ agglutinin Northwest Center for Medical Education, Indiana University School of Medicine, Gary, Indiana 46408horseradish peroxidase (WGANorthwest Center for Medical Education, Indiana University School of Medicine, Gary, Indiana 46408HRP) transported anterogradely from dorsal root ganglia. Labeled fibers were seen in large numbers in the ureter and in the lining of the renal pelvis, where they were located in the adventitia, smooth muscle, subepithelial connective tissue, and epithelium. Most of the fibers in the ureter and ureteropelvic junctional zone traveled parallel to the long axis of the organ. In contrast, fibers in the widest part of the funnel Northwest Center for Medical Education, Indiana University School of Medicine, Gary, Indiana 46408shape renal pelvis were oriented predominantly in a circumferential fashion. Many of the pelvic afferents were extremely fine and appeared to terminate as free nerve endings. Modest networks of labeled axons were also observed around branches of the renal artery; the greatest innervation was supplied to the distal portions of the interlobar arteries and to the arcuate arteries. Only single axons were observed around the interlobular arteries, and very few fibers were seen around afferent arterioles or near glomeruli. In contrast to the arteries, branches of the renal vein were relatively sparsely innervated. Occasional labeled fibers entered the renal cortex and formed intimate associations with renal tubules; however, the vast majority of renal tubular elements were not contacted by labeled sensory fibers. Labeled fibers were never observed in the renal medulla or in the papilla. The present study represents the first time that the sensory innervation of the kidney and ureter has been investigated by using a highly specific anterograde nerve tracing technique. The pattern of innervation demonstrated here reveals an anatomical configuration of ureteral and renal pelvic sensory nerves consistent with a role in detection of ureteral and pelvic pressure and chemical changes and a renal vascular sensory innervation that may monitor changes in renal arterial and venous pressure and chemical content. Still other renal afferent nerve endings may signal renal pain.
Understanding of Pollution among 4th, 8th, and 11th Grade Students

Abstract This study assessed 4th, 8th, and 11th grade students' understanding of natural and social science concepts related to pollution. A representative sample of public school students (n = 105) in 11 Maine schools was selected, and students were interviewed on four concept principles considered critical to a full understanding of the pollution problem. The concept of pollution included the much publicized issues of solid and toxic waste as well as air, soil, and water pollution. Research assertions were summarized in generalized correct concept statements indicating the extent of current student knowledge. Common misconceptions were also noted. This study considered student understanding from a human ecological perspective, that is, as an integrated set or cluster of concepts related to pollution. This reflects a complex, integrated, and multidisciplinary conception of natural phenomena. Human constructivism, meaningful learning theory, and principles related to the relevance of student schema in the...
Structures of pure and Ca-segregated MgO (001) surfaces

The structures of pure and Ca-segregated MgO (001) surfaces have been studied using first-principles density-functional theory. The relaxation and rumpling for the pure surface are found to be 0.48% and 1.62%, respectively. Ca segregation significantly modifies the surface structure. The surface-segregated Ca atoms protrude outwards owing to the size mismatch between Ca and Mg. Consequently, their nearest neighbor oxygen atoms are pulled up. The value of the protrusion of Ca atoms is strongly dependent on the Ca coverage of the surface.
Origins of the high catalytic activity of human alcohol dehydrogenase 4 studied with horse liver A317C alcohol dehydrogenase.

Abstract The turnover numbers and other kinetic constants for human alcohol dehydrogenase (ADH) 4 (“stomach” isoenzyme) are substantially larger (10–100-fold) than those for human class I and horse liver alcohol dehydrogenases. Comparison of the primary amino acid sequences (69% identity) and tertiary structures of these enzymes led to the suggestion that residue 317, which makes a hydrogen bond with the nicotinamide amide nitrogen of the coenzyme, may account for these differences. Ala-317 in the class I enzymes is substituted with Cys in human ADH4, and locally different conformations of the peptide backbones could affect coenzyme binding. This hypothesis was tested by making the A317C substitution in horse liver ADH1E and comparisons to the wild-type ADH1E. The steady-state kinetic constants for the oxidation of benzyl alcohol and the reduction of benzaldehyde catalyzed by the A317C enzyme were very similar (up to about 2-fold differences) to those for the wild-type enzyme. Transient kinetics showed that the rate constants for binding of NAD + and NADH were also similar. Transient reaction data were fitted to the full Ordered Bi Bi mechanism and showed that the rate constants for hydride transfer decreased by about 2.8-fold with the A317C substitution. The structure of A317C ADH1E complexed with NAD + and 2,3,4,5,6-pentafluorobenzyl alcohol at 1.2 A resolution is essentially identical to the structure of the wild-type enzyme, except near residue 317 where the additional sulfhydryl group displaces a water molecule that is present in the wild-type enzyme. ADH is adaptable and can tolerate internal substitutions, but the protein dynamics apparently are affected, as reflected in rates of hydride transfer. The A317C substitution is not solely responsible for the larger kinetic constants in human ADH4; thus, the differences in catalytic activity must arise from one or more of the other hundred substitutions in the enzyme.
Cryostat design and fabrication for the Gemini NIRI instrument

ABSTRACT The Gemini Near Infrared Imager (NIRI) is a cryogenic instrument cooled by two closed-cycle cryo-coolers. The vacuumjacket is a hexagon shaped vacuum vessel made of three sections. Each section is forged out of aluminum 606 1 . All theinternal structural components are made of aluminum 6061T6 except the supporting trusses, which are made of titanium.All the internal structural members are stress relieved to maintain dimensional stability and good optical alignment. Thethennal insulation includes floating shields and cold shields. Two closed-cycle coolers are mounted opposite to each otherand electronically synchronized in order to cancel the vibration caused by the oscillating expansion valve. Several differentfabrication methods and stress relief methods are discussed.KEYWORD: infrared, instrument, cryogenic, cooler, vacuum, cryostat, radiation, shield, aluminum, titanium 1. Introduction The Gemini Near Infrared Imager (NIRI) [11 will be the main infrared imaging instrument on the 8-meter Gemini NorthTelescope. It will be used for the commissioning of the telescope and the characterization of its performance. NIRI is beingdesigned and fabricated by the University ofHawaii Institute for Astronomy under contract from AURA.The ciyostat consists of the following major components: the vacuum jacket (vacuum vessel), main work surface, imageroptical table, on-instrument-wave4ront-sensor (OIWFS) optical table, internal mounting trusses, closed cycle coolers,floating radiation shields, cold shields, and photon shields.The vacuumjacket is the enclosure of the instrument. It provides a high vacuum and ciyogemc environment for the infraredarray and all the optics inside the vacuum jacket. The main work surface is a 40-mm thick aluminum plate. It is attachedto the vacuum jacket through three pairs of titanium trusses. All the rest of the internal components and assemblies aremounted on the main work surface. The main work surface is like a partition, dividing the instrument into two sections:Imager section and WFS section. The imager optical table is mounted on one side of the main work surface, the WFSoptical table is mounted on the other side of the main work surface.Two closed-cycle coolers are used to cool the instrument and maintain the operating temperature inside the vacuum jacketat about 60 °
Effect of Uniaxial Stresses on the Paramagnetic Spectra of Mn 3 + and Fe 3 + in MgO

We have investigated the lowest energy levels of the paramagnetic ions ${\mathrm{Mn}}^{2+}$ and ${\mathrm{Fe}}^{3+}$ in the host crystal MgO, as a function of externally applied uniaxial stress. The effect of the stress on the energy levels of the paramagnetic ion can be described by introducing into the spin Hamiltonian an additional term of the form $\mathrm{S}\ifmmode\cdot\else\textperiodcentered\fi{}D\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{S}$. When the components of $D$ are expressed as linear functions of the applied stress components, there are only two independent constants of proportionality in our simple case of a cubic crystalline lattice. We have experimentally determined these two constants, i.e., spin-lattice coefficients ${C}_{11}$ and ${C}_{44}$, for ${\mathrm{Mn}}^{2+}$ and ${\mathrm{Fe}}^{3+}$ in MgO, and find them to be, in units of ${10}^{\ensuremath{-}13}$ cm/dyne: for ${\mathrm{Mn}}^{2+}$, ${C}_{11}=(+7.1\ifmmode\pm\else\textpm\fi{}3)%$ and ${C}_{44}=(\ensuremath{-}2.1\ifmmode\pm\else\textpm\fi{}3)%$; for ${\mathrm{Fe}}^{3+}$, ${C}_{11}=(+26\ifmmode\pm\else\textpm\fi{}3)%$ and ${C}_{44}=(\ensuremath{-}5.5\ifmmode\pm\else\textpm\fi{}5)%$. We have also investigated the absolute value and the angular dependence of the linewidth of the fine structure of ${\mathrm{Mn}}^{2+}$ and ${\mathrm{Fe}}^{3+}$ in MgO. We can account for these widths in terms of the spin-lattice coefficients, by assuming a random distribution of internal stresses in the host sample. We also indicate the relevance of the spin-lattice coefficients in the determination of the direct spin-lattice relaxation times.
The oxidation and rumpling behavior of overlay B2 bond coats containing Pt, Pd, Cr and Hf

Abstract The behavior of Hf-modified B2 nickel aluminide bond coatings, fabricated by ion-plasma deposition, has been investigated under thermal cycling conditions. The mass change, surface roughness, and microstructural evolution have been characterized. Variation in the Al, Cr, Pd and Pt concentrations did not affect the initial oxidation or rumpling behavior of these bond coats, but did influence oxide adherence as well as the surface roughness at failure. Both the Pt and, interestingly, the Pd-modified coatings displayed superior cyclic oxidation lifetimes compared to the state-of-the-art platinum aluminide coatings. The rate of surface roughening (rumpling) is discussed in terms of the B2 to L1 2 phase transformation and oxide spallation.
Catalytic reduction of carbon monoxide over potassium modified iron surfaces

Abstract The catalytic reduction of carbon monoxide (Fischer-Tropsch chemistry) over iron and potassium modified iron surfaces has been studied. The study was carried out in a combined micro-reactor surface analysis system. This combination permits pre-reaction and post-reaction surface analysis to be coupled with medium pressure (5–10 atm) catalytic reaction studies. Iron surfaces in the absence of surface alkali exhibit a high hydrogenation activity resulting in a product distribution consisting of small (C 1 to C 6 ) alkanes. Investigation of the surface after reaction by XPS reveals substantial surface carbon of a mixed carbidic and graphitic nature. The modification of the iron surface by K 2 CO 3 pretreatment dramatically lowers the hydrogenation activity of the surface resulting in product rich in alkenes and low in methane. The potassium treated surface after reaction was covered with a multilayer carbonaceous deposit. The carbon deposit is similar in nature to the reaction products and is best characterized as polymethylene.
Pure strategy nash equilibria with continuous objectives

Abstract This paper looks at the question of the existence of a pure strategy Nash equilibrium if the assumption of quasi-concavity of objective functions is dropped. The analysis focuses on the space of reaction correspondences of firms. It is shown that for an open and dense subset of this space, there does not exist a Nash equilibrium. This is shown to imply that in the space of continuous objective functions, an open and dense subset does not have a Nash equilibrium.
Effects of moisture content on the storage stability of dried lipoplex formulations

The purpose of this study is to investigate the effects of moisture content on the storage stability of freeze-dried lipoplex formulations. DC-Cholesterol: DOPE (dioleoyl phosphatidylethanolamine)/plasmid DNA lipoplexes were prepared at a 3-to-2 DC-Cholesterol(+) to DNA(-) molar ratio and lyophilized prior to storing at room temperature, 40, and 60 degrees C for 3 months. Different residual moistures (1.93%, 1.10%, 1.06%, and 0.36%) were obtained by altering the secondary drying temperatures. In addition to moisture content, lipoplex formulations were evaluated after freeze-drying and/ or storage for particle size, transfection efficiency, accumulation of thiobarbituric acid reactive substances (TBARS), glass transition temperature, DNA supercoil content, and surface area. Lipoplex formulations stored at room temperature for 3 months maintain TBARS concentrations and supercoil contents. At higher storage temperatures, formulations possessing the highest moisture content (1.93%) maintained significantly lower TBARS concentrations and higher supercoil content than those with the lowest (0.36%) moisture content. Curiously, the intermediate moisture contents exhibited marked differences in stability despite virtually identical moisture contents. Subsequent measurements of surface area indicated that the lower stability corresponded to higher surface area in the dried cake, suggesting that there may be an interplay between water content and surface area that contributes to storage stability.
Imagining a transformed UNESCO with learning at its core

Abstract This paper argues that key aspects of UNESCO's organizational culture are a major impediment to the realization of its important educational agenda. Drawing upon sustained observations over a four-year period, the paper describes the nature and consequences of UNESCO's highly ritualized and ‘inward-oriented’ work activities, especially the weak links between what happens at Headquarters and the realities on the ground in formal and non-formal educational frameworks worldwide. By establishing a more open, interactive and egalitarian organizational milieu, focused on collaborative learning and knowledge creation, accumulation and dissemination, this paper argues that these linkages can be tightened. A genuine learning-oriented culture at UNESCO would encourage professional empowerment, independent thinking, human resource development, greater dialogue and critical debate, and the creation and dissemination of quality publications. Thus, for UNESCO to regain its leadership role in the education world and effectively serve as a broker of innovative ideas and effective programs, it must overcome the stultifying tendencies of its current organizational culture and find ways to develop dynamic learning cultures both from without and from within.
HIV/AIDS: Its Impact in the Zimbabwean School Curriculum

This report presents the findings of the impact of HIV/AIDS on the quality of education in rural secondary schools in the Zaka district, Zimbabwe. The methodology involved ten rural secondary schools and a sample of 20 teachers (10 males and 10 females) and 40 students (20 boys and 20 girls). This study used a qualitative methodology throughout the interview sessions because “letting people talk” has been found by most social researchers to be the most appropriate when dealing with this nature of research. Findings in this study indicated that the quality of education is being impacted by the HIV/AIDS epidemic. The quality of education is being impacted by the HIV/AIDS epidemic mainly because trained teachers are lost due to illness and death; student-teacher contact is reduced as a result of permanent or temporary absenteeism of teachers and students. The findings also suggest that students with parents that are infected with HIV/AIDS were mostly affected. This research study recommends that schools should establish Anti-AIDS clubs to educate students about HIV/AIDS transmission and prevention as well as to deal with the needs of those affected with the virus. The study further recommends that students should develop a culture of reading material on HIV/AIDS so as to gain a better understanding and hence make informed decisions about sexual behaviour. DOI: 10.5901/mjss.2013.v4n13p773
Vinyl-β-lactams as Efficient Synthons. Eco-friendly Approaches via Microwave Assisted Reactions

Abstract Vinyl-β-lactams are efficient synthons for a variety of compounds of biomedical interest—such as isocephalosporins, carbapenem and thienamycin intermediates, and pyrrolidine alkaloids. Convenient methods are described for obtaining both enantiomers of some of these synthons. Microwave-induced Organic Reaction Enhancement (MORE) chemistry techniques allow highly accelerated synthesis of variously substituted vinyl-β-lactams using limited amounts of solvents and with efficient stereocontrol—thus achieving high ‘atom economy’. The effect (if any) of microwaves on bond angles and bond lengths and the geometry of transition states are not well understood yet. Nonetheless, reactions under microwave irradiation in open systems are rapid, safe, and cost-effective for synthetic approaches that are much more friendly to the environment than conventional processes.
Hierarchical Organization of Modularity in Metabolic Networks

Spatially or chemically isolated functional modules composed of several cellular components and carrying discrete functions are considered fundamental building blocks of cellular organization, but their presence in highly integrated biochemical networks lacks quantitative support. Here, we show that the metabolic networks of 43 distinct organisms are organized into many small, highly connected topologic modules that combine in a hierarchical manner into larger, less cohesive units, with their number and degree of clustering following a power law. Within Escherichia coli, the uncovered hierarchical modularity closely overlaps with known metabolic functions. The identified network architecture may be generic to system-level cellular organization.
An improved high performance liquid chromatographic method for the quantification of solasodine

An improved isocratic high performance liquid chromatographic method for the quantification of solasodine, an alternative precursor for the commercial production of steroid drugs, is reported. A highly sensitive and reproducible assay for solasodine quantification was achieved using a base-deactivated C-8 column and an acidic mobile phase. Sharp symmetrical peaks were obtained and a linear relationship between the amount of solasodine injected and the area under the peak was achieved. The method allows the simultaneous identification and quantification of solasodine in plant tissue samples at amounts as low as 0.40 μg, and reports the actual amounts of solasodine in the sample rather than the “solasodine equivalents” as determined by previously published methods. Copyright © 1999 John Wiley & Sons, Ltd.
High-Performance Liquid Chromotography Analysis of 8-Methoxypsoralen Monoadducts and Crosslinks in Lymphocytes and Keratinocytes

Human lymphocytes and murine keratinocytes were treated with clinically relevant doses of 8-methoxypsoralen and long-wavelength ultraviolet radiation. The extent of 8- MOP photoadduct formation was determined by liquid scintillation analysis. The distribution of photoadducts was determined by HPLC analysis of enzymatically hydrolyzed DNA from these cells. Analysis of photoadduct formation in lymphocytes and keratinocytes showed that 4',5'-monoadducts were the predominant photoadducts (42% and 41%, respectively). Monoadduct and crosslink yields were dependent on cell type as well as irradiating wavelength. The photochemical conversion of 400 nm-induced 4',5'-monoadducts to crosslinks, as well as 3,4-monoadducts in poly(dA-dT) was measured.