cssi/SciSciGPT-SciSciNet huggingface dataset:
An experimental study of the formation of metallic iron in chondrules

Abstract The abundance of metallic iron is highly variable in different kinds of chondrites. The precise mechanism by which metal fractionation occurred and its place in time relative to chondrule formation are unknown. As metallic iron is abundant in most Type I (FeO-poor) chondrules, determining under what conditions metal could form in chondrules is of great interest. Assuming chondrules were formed from low temperature nebular condensate, we heated an anhydrous CI-like material at 1580°C in conditions similar to those of the canonical nebula (P H2 = 1.3 × 10 −5 atm). We reproduced many of the characteristics of Type IA and IIA chondrules but none of them contained any iron metal. In these experiments FeO was abundant in charges that were heated for as long as 6 h. At a lower temperature, 1350°C, dendritic/cellular metal crystallized from Fe-FeS melts during the evaporation of S. However, the silicate portion consisted of many relict grains and vesicles, not typical of chondrules. Evaporation experiments conducted at P H2 = 1 atm and 1565°C produced charges containing metallic iron both as melt droplets and inclusions in olivine, similar to those found in chondrules. Formation of iron in these experiments was primarily the result of desulfurization of FeS. With long heating times Fe° was lost by evaporation. Apart from some reduction of FeO by kerogen to make metal inclusions within olivine grains, reduction of FeO to make Fe° in these charges was not observed. This study shows that under canonical nebular conditions FeS and iron-metal are extremely volatile so that metal-rich Type I chondrules could not form by melting “CI.” Under these conditions FeO is lost predominantly by hydrogen stripping and, due to the relative low abundance of hydrogen at low pressures, remains in the melt for as long as 6 h. Conversely, at higher total pressures (1-atm H 2 ) iron metal (produced mainly by the desulfurization of troilite) is less volatile and remains in the melt for longer times (at least 6 h). In addition, due to elevated pressures of hydrogen, FeO is stripped away much faster. These results suggest that chondrule formation occurred in environments with elevated pressures relative to the canonical nebula for iron metal to be present.
Treatment of chronic hepatitis B

Interferon (IFN) alpha, lamivudine, and adefovir are the three antiviral therapies currently approved for the treatment of chronic hepatitis B virus (HBV). Initiation of treatment is indicated in patients with abnormal liver enzymes and markers of active viral replication (ie, HBV DNA positive). Hepatitis B early antigen seroconversion rates are higher and treatment duration is shorter with IFN than with lamivudine or adefovir. However, treatment results in frequent side effects and many patients have contraindications to therapy. Lamivudine and adefovir are better tolerated, but have lower seroconversion rates after 12 months of treatment. Resistance develops in 20% of lamivudine patients after 12 months; adefovir resistance has not been identified to date. Individualization of therapy, based on factors such as patient comorbidities, response to prior therapies, and stage of disease (ie, presence of cirrhosis), is recommended. All patients over the age of 40 or with advanced liver disease should be continually screened for hepatocellular carcinoma with serum alphafetoprotein and abdominal imaging every 6 months.
Use of indirect site-directed mutagenesis to alter the substrate specificity of methylamine dehydrogenase.

Methylamine dehydrogenase (MADH) is a tryptophan tryptophylquinone-dependent enzyme that catalyzes the oxidative deamination of primary amines. Native MADH exhibits a strong preference for methylamine over longer carbon chain amines. Residue αPhe55 controls this substrate specificity. When αPhe55 is replaced with Ala, this preference is reversed with αF55A MADH preferring long-chain amines with at least seven carbons (Zhu, Z., Sun, D., and Davidson, V. L. (2000)Biochemistry 39, 11184–11186). To further modulate the substrate specificity of MADH, the side-chain of αPhe55was repositioned by site-directed mutagenesis of residue βIle107. This residue makes close contact with αPhe55 and restricts its movement. βI107V MADH exhibits a strong preference for propylamine, and βI107N MADH exhibits a preference for 1-aminopentane. Thus, it has been possible to create forms of MADH that exhibit a preference for amines with carbon chain lengths of one, three, five, or seven carbons. The ability to discriminate between amines of different chain length was essentially abolished by an αF55I mutation. Molecular modeling studies with the known crystal structure are described that provide an explanation for these results. These results provide an example of a design-based approach to protein engineering in which site-directed mutagenesis on one residue can be used to reposition another residue to specifically alter enzyme specificity.
What can sociology teach us about the ideational origins of modernity? Comments on McCloskey's Bourgeois Dignity

► Bourgeois Dignity offers compelling history of the rise of the modern world. ► Sociological work on markets and morals provides theoretical springboard. ► Economists should start paying attention to discourse in markets.
A routing architecture for scheduled dynamic circuit services

A wide range of applications in the nascent field of cloud computing and in other fields require stable, low-delay wide-area connectivity together with capabilities of co-scheduling network and server resources. As a result, both research and commercial providers have recently started to deploy scheduled dynamic circuit services (SDCS) as a complement to their IP-routed and leased-line service offerings. Under such services, corporations, universities, or end-users dynamically place requests for a fixed-rate circuit lasting for a fixed duration, for either earliest possible usage or scheduled usage at some point in the future. The lack of adequate support for inter-domain routing and provisioning represents, however, a major hurdle to the full-scale deployment of SDCS. Indeed, existing protocols, such as BGP, do not cater to future dynamic allocation and scheduling of network resources. In this paper, we introduce a strawman protocol, called scheduled circuit routing protocol (SCRP), geared towards inter-domain routing in SDCS-based architectures. The purpose of this protocol is to report available bandwidth information as a function of time across domains without revealing internal network topologies. We describe tradeoffs associated with the design of such a protocol, more particularly the challenge of ensuring high performance while maintaining low implementation complexity, and present avenues for future research.
Intracellular dynamics of hippocampal place cells during virtual navigation

Hippocampal place cells encode spatial information in rate and temporal codes. To examine the mechanisms underlying hippocampal coding, here we measured the intracellular dynamics of place cells by combining in vivo whole-cell recordings with a virtual-reality system. Head-restrained mice, running on a spherical treadmill, interacted with a computer-generated visual environment to perform spatial behaviours. Robust place-cell activity was present during movement along a virtual linear track. From whole-cell recordings, we identified three subthreshold signatures of place fields: an asymmetric ramp-like depolarization of the baseline membrane potential, an increase in the amplitude of intracellular theta oscillations, and a phase precession of the intracellular theta oscillation relative to the extracellularly recorded theta rhythm. These intracellular dynamics underlie the primary features of place-cell rate and temporal codes. The virtual-reality system developed here will enable new experimental approaches to study the neural circuits underlying navigation.
Integrating History and Philosophy of the Life Sciences in Practice to Enhance Science Education: Swammerdam’s Historia Insectorum Generalis and the Case of the Water Flea

Hasok Chang (Sci Educ 20:317–341, 2011) shows how the recovery of past experimental knowledge, the physical replication of historical experiments, and the extension of recovered knowledge can increase scientific understanding. These activities can also play an important role in both science and history and philosophy of science education. In this paper I describe the implementation of an integrated learning project that I initiated, organized, and structured to complement a course in history and philosophy of the life sciences (HPLS). The project focuses on the study and use of descriptions, observations, experiments, and recording techniques used by early microscopists to classify various species of water flea. The first published illustrations and descriptions of the water flea were included in the Dutch naturalist Jan Swammerdam’s, Historia Insectorum Generalis (1669) (Algemeene verhandeling van de bloedeloose dierkens. t’Utrrecht, Meinardus van Dreunen, ordinaris Drucker van d’Academie). After studying these, we first used the descriptions, techniques, and nomenclature recovered to observe, record, and classify the specimens collected from our university ponds. We then used updated recording techniques and image-based keys to observe and identify the specimens. The implementation of these newer techniques was guided in part by the observations and records that resulted from our use of the recovered historical methods of investigation. The series of HPLS labs constructed as part of this interdisciplinary project provided a space for students to consider and wrestle with the many philosophical issues that arise in the process of identifying an unknown organism and offered unique learning opportunities that engaged students’ curiosity and critical thinking skills.
Use of hypothermia for general anesthesia in preweanling rodents

Documentation and rationale are provided for the use of deep hypothermia alone for anesthesia during surgical manipulations in young preweanling rodents and moderate hypothermia as an adjunct to other anesthesia in older preweanling animals. Techniques and applications for the procedure are also described.
Developmental psychobiological influences on rodent parental behavior

The present paper focuses on the development, broadly defined, of parental responsiveness. Both sexes can respond to young with parental behavior, in the absence of elaborate experimental manipulations; yet, through the combined natural forces of ontogeny and maturation, organizational influences of hormones, and adult modifications of neurochemical sensitivity, these animals can be rendered more or less sensitive to young. We will explore the ways in which such developmental alterations determine whether or not an animal is responsive to neonates.
The Emergence of Complexity, Fluency, and Accuracy in the Oral and Written Production of Five Chinese Learners of English

Seeing language as a complex, dynamic system and language use/acquisition as dynamic adaptedness ('a make-do' solution) to a specific context proves a useful way of understanding change in progress, such as that which occurs with a developing L2 system. This emergentist shift of perspective provides another way of understanding previously observed characteristics of learner language, that is that its development is not discrete and stage-like but more like the waxing and waning of patterns; that, from a target-language perspective, certain aspects of the behavior are progressive, others, regressive; that change can be gradual and it can- be sudden; and that the latter notably heralds the emergence of a new order qualitatively different and novel from earlier organizations. In addition, when group data are disaggregated, it is clear that there are many paths to development. By closely examining the oral and written production of five Chinese learners of English, the emergence of complexity, fluency, and accuracy can be seen, not as the unfolding of some prearranged plan, but rather as the system adapting to a changing context, in which the language resources of each individual are uniquely transformed through use.
Are pulp and paper mills sources of toxaphene to Lake Superior and northern Lake Michigan

Abstract Toxaphene was a broad-spectrum pesticide consisting of a mixture of highly chlorinated bornanes and bornenes. After its ban in 1982, toxaphene concentrations have shown a general decline in the environment as a whole and in most of the Great Lakes specifically. Recent work, however, shows that toxaphene concentrations are not decreasing in fishes from Lake Superior and northern Lake Michigan. Non-atmospheric, relatively localized sources are a possible explanation for these observations. For example, toxaphene could be inadvertently produced and released by pulp and paper mills, which could be synthesizing toxaphene-like compounds as a byproduct of bleached paper production. Reported here is a study of surficial river sediment collected upstream and downstream from seven pulp and paper mills, from five areas of previous toxaphene use, and from two presumed pristine locations. Concentrations of toxaphene found downstream are similar to those found upstream from each of the pulp and paper mills. Concentrations in sediment from rivers near previous toxaphene use locations were higher than concentrations in the background samples. These data suggest that pulp and paper mills are not now sources of toxaphene but that toxaphene used as a pesticide in the Great Lakes basin (although these uses were very small compared to its use in the southern US) could be a potential source.
Structure of an Evolving Hailstorm, Part II: Thermodynamic Structure and Airflow in the Near Environment

Abstract A diverse set of mesoscale observations collected in the National Hail Research Experiment in connection with an evolving Colorado hailstorm is analyzed to determine the kinematic and thermodynamic structure of the near environmental and subcloud regimes. The analysis centers on multi–level aircraft measurements in the inflow sector and on mesoscale observations at the surface and aloft. Although considerable evolution was observed in overall radar echo development patterns, changes in one of the many storms detected occurred in a systematic and periodic manner. The instantaneous structure of the subcloud inflow into this storm is emphasized in the present work. Surface and aircraft data substantiate the following characteristics. Inflow air approached the front of the storm, originating from a very shallow layer (≤5 m) near the ground and at a considerable distance (≥20 km) upstream in the relative wind direction. Inflow air rose unmixed to at least cloud base, feeding the main updraft which was...
NEW LEPTONS: AN EXPERIMENTAL REVIEW

We review experimental knowledge on what are usually called heavy leptons, but we call new leptons. These are leptons other than the electron, muon, and their associated neutrinos. The measured properties of the tau lepton are surveyed, including a discussion of the inconsistencies in present knowledge of its one-charged-particle decay modes. We summarize experimental limits on the existence of other possible leptons. We conclude the review with a discussion of searches which can be made with the new and proposed particle colliders.
Effect of Fluoride-Containing Zinc Oxide-Eugenol Cements on Solubility of Enamel

The solubility of intact enamel surface was reduced by contact with zinc oxide-eugenol formulations to which sodium fluoride or stannous fluoride was added. The magnitude of the reduction was comparable to that incurred in enamel in contact with silicate cement. No change in solubility was observed when fluoridefree zinc oxide-eugenol cements were used.
The cell wall is a real drag.

Martiniere et al. (1), at long last, take a critical look at the general mobility of proteins in the plant plasma membrane. Hundreds of studies looking at the active or diffusion-limited transport of proteins in the animal cell plasma membrane paint a complex picture. There are mammalian proteins that wander the membrane aimlessly, proteins corralled into pens by the cytoskeleton, proteins that become stuck in a cholesterol-rich mud, and even proteins that anchor themselves to the ECM (2). From these broader findings, it appears clear that animal cells exploit the restriction of proteins to a 2D lipid plane for complex outcomes. At issue in plant cells is almost every property that has ever been ascribed to the transport of a plasma membrane protein in a cellular system. A systematic study of how different classes of membrane proteins move within the plant plasma membrane simply has not been done.
Electrochemical studies on stacked-ring silicon phthalocyanines

Abstract Voltammetric and spectroscopic data on monomeric, dimeric, and trimeric t-butyldimethylsilyl silicon phthalocyanines (SiPc) are compared. These phthalocyanines are bonded through axial OSiO linkages with an interplanar spacing of about 0.34 nm. The through-space orbital interactions which result from the cofacial orientation of the SiPc rings causes a large stabilization of the one-electron oxidation product of the dimer and trimer SiPc compared to the monomer SiPc and a slight destabilization of their one-electron reduction products. The electrochemical reactions have significance in correlation with the conductivity, photoconductivity, and solid-state orientation of phthalocyanines which aggregate or polymerize.
The CC chemokine receptor 5 regulates olfactory and social recognition in mice

Abstract Chemokines are chemotactic cytokines that regulate cell migration and are thought to play an important role in a broad range of inflammatory diseases. The availability of chemokine receptor blockers makes them an important therapeutic target. In vitro , chemokines are shown to modulate neurotransmission. However, it is not very clear if chemokines play a role in behavior and cognition. Here we evaluated the role of CC chemokine receptor 5 (CCR5) in various behavioral tasks in mice using Wt ( Ccr5 + / + ) and Ccr5 -null ( Ccr5 − / − ) mice. Ccr5 − / − mice showed enhanced social recognition. Administration of CC chemokine ligand 3 (CCL3), one of the CCR5-ligands, impaired social recognition. Since the social recognition task is dependent on the sense of olfaction, we tested olfactory recognition for social and non-social scents in these mice. Ccr5 − / − mice had enhanced olfactory recognition for both these scents indicating that enhanced performance in social recognition task could be due to enhanced olfactory recognition in these mice. Spatial memory and aversive memory were comparable in Wt and Ccr5 − / − mice. Collectively, these results suggest that chemokines/chemokine receptors might play an important role in olfactory recognition tasks in mice and to our knowledge represents the first direct demonstration of an in vivo role of CCR5 in modulating social behavior in mice. These studies are important as CCR5 blockers are undergoing clinical trials and can potentially modulate behavior.
A new feature selection algorithm for two-class classification problems and application to endometrial cancer

In this paper, we introduce a new algorithm for feature selection for two-class classification problems, called l 1 -StaR. The algorithm consists of first extracting the statistically relevant features using the Student t-test, and then passing the reduced feature set to an l 1 -norm support vector machine (SVM) with recursive feature elimination (RFE). The final number of features chosen by the l 1 -StaR algorithm can be smaller than the number of samples, unlike with l 1 -norm regression where the final number of features is bounded below by the number of samples. The algorithm is illustrated by applying it to the problem of determining which endometrial cancer patients are at risk of having the cancer spreading to their lymph nodes. The data consisted of 1,428 micro-RNAs measured on a data set of 94 patient samples (divided evenly between those with lymph node metastasis and those without). Using the algorithm, we identified a subset of just 15 micro-RNAs and a linear classifier based on these, that achieved two-fold cross validation accuracies in excess of 80%, and combined accuracy, sensitivity and specificity in excess of 93%.
Representation of serial order in speech: evidence from the repeated phoneme effect in speech errors.

Previous research has shown that slips of the tongue involving the exchange of phonemes (e.g., left hemisphere----left hemisphere) are often characterized by a repeated phoneme next to the exchanging ones (the vowel /epsilon/ in the above example is next to both of the exchanging sounds, /l/ and /h/). Two experiments, which elicited slips of the tongue under controlled conditions, revealed that repeated sounds in a speech plan are contributory causes of phoneme exchanges, anticipations, and perseverations. In addition, it was found that repeated sounds induce the misordering of sounds that are not adjacent to the repeated ones, as well as those that are adjacent to the repeated ones. An analysis of a collection of natural slips also supported the conclusion that repeated sounds cause nonadjacent sounds to slip. The results are seen as inconsistent with serial order theories that propose a linear structure of sounds held together by contextual influences between adjacent phonemes.
Limitation of ribosomal protein L11 availability in vivo affects translation termination.

Historically referred to as "the GTPase center", the L11 binding region (L11BR) of Escherichia coli 23 S rRNA is a highly conserved structure that has been implicated in several essential functions during protein synthesis. Here, in vivo expression of an RNA fragment containing that structure was found to affect translation termination in a codon-specific manner. The cause of these effects appeared to be titration of ribosomal protein L11, since normal phenotypes could be restored by simultaneous overproduction of wild-type L11 but not mutant L11. Subsequently, altered termination phenotypes were produced when the availability of L11 was limited by overexpression of RNA antisense to L11 mRNA and, finally, by inactivation of the chromosomal L11 gene, and they too were reversible by simultaneous expression of cloned L11. Our results indicate that in the intact cell the L11BR is an integral functional unit important for translation termination and that the presence of L11 in ribosomes is required for UAG-dependent termination and is somewhat inhibitory of UGA-dependent termination.
Prevalence and trends of receipt of cancer screenings among US women with diagnosed diabetes.

BACKGROUND Diabetes increases the risk of breast and colorectal cancers and has an undetermined relationship to cervical cancer. Improved screenings for these cancers are effective in reducing cancer mortality.
An Innovative Way to Measure Temperature by Using the Faraday Effect

An innovative temperature sensor has been presented based on “Faraday Effect”. The Faraday Effect or the Faraday rotation is a magneto-optical phenomenon; that is, an interaction between electromagnetic wave and a magnetic field in a medium. Optical sensors based on the Faraday Effect have the advantages of simplicity, high electrical insulation and immunity to electromagnetic interference. We will be making use of an optical fiber and a permanent magnet as our sensing elements. The magnet will be the sensing element for change in temperature and the fiber optic cable will sense the change in magnetic field intensity corresponding to the change in temperature.Copyright © 2011 by ASME
Introduction to special issue of sleep medicine.

The field of sleep medicine is in a welcome stage of rapid advance, but at a pace that leads to a sometimes overwhelming overload of knowledge for both clinicians and researchers. The nine papers in this issue are designed to give the reader an organized overview of current thinking and background in Basic Science, Clinical Science and Therapeutic Measures, the major divisions of this special issue. An important trend is the increasing development of basic science knowledge relevant to understanding and treating the clinical features of sleep disorders. The therapeutic advances section covers both the treatment of narcolepsy and the role of non‐invasive ventilation. The recent neurobiologic knowledge that narcolepsy‐cataplexy results from a deficiency of the hypothalamic neuropeptide hypocretin (orexin) has opened has opened the exciting possibility of using novel therapies. Despite this new knowledge, traditional stimulants and anticataplectic agents including modafinil, a novel wake‐promoting agent and selective serotonergic, adrenergic and dopaminergic reuptake inhibitors and recently introduced sodium oxybate remain the mainstay of treatment for this condition. To whet the reader’s appetite and to offer a road map for possible reading, we briefly summarize the content of the papers.
Evaluating N-benzylgalactonoamidines as putative transition state analogs for β-galactoside hydrolysis.

Experimental evidence is provided for p-methylbenzyl-D-galactonoamidine to function as a true transition state analog for the enzymatic hydrolysis of aryl-β-D-galactopyranosides by β-galactosidase (A. oryzae). The compound exhibits inhibition constants in the low nanomolar concentration range (12–56 nM) for a selection of substrates. Along these lines, a streamlined synthetic method based on phase-transfer catalysis was optimized to afford the required variety of new aryl-β-D-galactopyranosides. Last, the stability of the galactonoamidines under the assay conditions was confirmed.
Thorax — A program to assist in the preoperative risk assessment of patients undergoing thoracic surgery

Patients who undergo thoracic surgical procedures often are at high risk. Several risk-scoring systems have been advocated; they are complex and unwieldy. Also, physicians-in-training need a teaching tool with a consistent format. A program for these needs has been written in the high-level language Modula-2 for the Macintosh Computer. The user enters height, weight and easily obtainable data. Normal values are accessed via a ‘window’ which is triggered by clicking the ‘mouse’. When pulmonary data is entered, cardiovascular system questions are presented. The user is finally presented with entered data, calculated data and a risk estimate. Complications estimates are derived from a special LEARNER file. The program ‘learns’ from a constantly expanding database.
Mechanical behavior of human cortical bone in cycles of advancing tensile strain for two age groups

The capacity of bone for post-yield energy dissipation decreases with age. To gain information on the causes of such a change, we examined age-related changes in the mechanical behavior of human cadaveric bone as a function of progressive deformation. In this study, tensile specimens from tibiae of nine middle aged and eight elderly donors were loaded till failure in an incremental and cyclic (load-dwell-unload-dwell-reload) scheme. The elastic modulus, maximum stress, permanent strain, stress relaxation, permanent strain energy, elastic release strain energy, and hysteresis energy were determined in each loading cycle at incremental strains. Similar with previous work, the results of the present study also indicated that elderly bone failed at much lower strains compared to middle aged bone. However, no significant differences in the mechanical behavior of bone were observed between the two age groups except for the premature failure of elderly bone. After yielding, the energy dissipation and permanent strain of bone appeared to linearly increase with increasing strain applied, while nonlinear changes occurred in the modulus loss and stress relaxation with increasing strain. Moreover, stress relaxation tended to peak at 1% strain beyond which few elderly bone specimens survived. This study suggests that damaging mechanisms in bone vary with deformation, and aging affects the post-yield mechanisms, thus giving rise to the age-related differences in the mechanical properties of bone, especially the capacity of the tissue for energy dissipation.
Effects of aging per se on arterial stiffness: systemic and regional compliance in beagles.

Abstract Although previous studies have suggested that aging results in an increase in vascular stiffness, diseases that increase in prevalence with advanced age may have confounded the results of some of this past research. The purpose of this investigation was to determine whether aging per se results in reduced arterial compliance by using animals that are resistant to atherosclerosis and do not develop hypertension or hyperlipidemias with advanced age. We evaluated systemic and regional (femoral) arterial compliance in older (110 ± 8 months old) and in younger (27 ± 2 months old) female beagle dogs by using a computer-based assessment of the diastolic decay of arterial pressure waveforms and a modified Windkessel model of the circulation. Although systemic arterial pressure was very similar in both age groups, cardiac output was 29% lower ( p = 0.03) and systemic vascular resistance was 24% higher ( p = 0.02) in the older dogs. Moreover, there was an age-related reduction in systemic arterial compliance, derived both from the exponential decay in the arterial pulse (C 1 ) ( p = 0.05) and that derived from the oscillatory component of the diastolic pulse wave (C 2 ) ( p = 0.04). By contrast, although femoral vascular resistance was 25% higher in the older dogs ( p = 0.04), regional (femoral) vascular compliance measured after femoral arterial occlusion was also 25% reduced but was not significantly changed with age ( p = 0.14). These results demonstrate that systemic arterial compliance is reduced with age in dogs, extending this finding to animals without age-related diseases that frequently occur in older human beings. Regional compliance, evaluated in the isolated femoral vascular bed, also tends to be reduced with age, but variability in this parameter in dogs reduces the significance of this finding.
EEG study of methysergida in migraine

Abstract 1. 1. The EEG effects of methysergida (UML-491) were studied in eleven patients with vascular headaches of the migraine type, four of whom had abnormal records. 2. 2. Acute intravenous administration produced transitory drowsiness in nine of the eleven and, in the EEG of seven, there was associated 4–6 c/sec theta activity. 3. 3. Prolonged oral administration of methysergida (UML-491) to four patients resulted in relief of headache in all four, but no significant change in any EEG. Previous EEG abnormalities in two of these patients remained unaltered.
Fractional coverage metrics based on ecological home range for calculation of the effective peak capacity in comprehensive two-dimensional separations.

Abstract Optimization of comprehensive two-dimensional separations frequently relies on the assessment of the peak capacity of the system. A correction is required for the fact that many pairs of separation systems are to some degree correlated, and consequently the entire separation space is not chemically accessible to solutes. This correction is essentially a measure of the fraction of separation space area where the solutes may elute. No agreement exists in the literature as to the best form of the spatial coverage factor. In this work, we distinguish between spatial coverage factors that measure the maximum occupiable space, which is characteristic of the separation dimensionality, and the space actually occupied by a particular sample, which is characteristic of the sample dimensionality. It is argued that the former, which we call f coverage , is important to calculating the peak capacity. We propose five criteria for a good f coverage metric and use them to evaluate various area determination methods that are used to measure animal home ranges in ecology. We consider minimum convex hulls, convex hull peels, α-hulls, three variations of local hull methods, and a kernel method and compare the results to the intuitively satisfying but subjective Stoll–Gilar method. The most promising methods are evaluated using two experimental LC × LC data sets, one with fixed separation chemistry but variable gradient times, and a second with variable first dimension column chemistry. For the 12 separations in the first data set, in which f coverage is expected to be constant, the minimum convex hull is the most precise method ( f coverage = 0.68 ± 0.04) that gives similar results to the Stoll–Gilar method ( f coverage = 0.67 ± 0.06). The minimum convex hull is proposed as the best method for calculating f coverage , because it has no adjustable parameters, can be scaled to different retention time normalizations, is easily calculated using available software, and represents the expected area of solute occupation based on a proposed linear free energy formalism.
Optimization and application of particle beam high‐performance liquid chromatography/mass spectrometry to compounds of pharmaceutical interest

Particle beam high-performance liquid chromatography/mass spectrometry (HPLC/MS) parameters were optimized for the sensitive analysis of several drugs in agricultural products such as milk and tissue. Sensitivity of the particle beam interface was greatest for solvents with low heat capacities (methanol greater than acetonitrile greater than isopropanol greater than water). Furthermore, optimal sensitivity was obtained at low solvent flow rates (about 0.4-0.6 ml min-1). Parameters such as desolvation temperature, helium flow rate to the nebulizer and nebulizer position resulted in minimal change in sensitivity. The source temperature was optimized to obtain suitable vaporization with minimal thermal degradation (200-300 degrees C). The determination of a variety of compounds (including beta-lactams, cephapirin, tetracyclines, methylene blue, furosemide, spectinomycin, cytidine, 2-chloro-4-nitrobenzamide and thiamine) was possible using the particle beam interface. Under full-scan conditions, detection limits were in the 100 ng range for most drugs. With selected ion monitoring, particle beam HPLC/MS was demonstrated for the analysis of p.p.m. levels of these drugs in milk and tissue extracts. Precision of the particle beam analysis was usually better than 15% RSD. For the same compounds, HPLC/MS with a thermospray interface often resulted in less structural information (single ion spectra) then obtained by particle beam with thermospray detection limits varying from 10 ng to 1 microgram.
Electrophysiological effects of enkephalin analogs in rat cortex

The microiontophoretic potencies of methionine-enkephalin (ME) analogs with similar charges but different potencies in the in vitro assays were studied with respect to spontaneous and evoked activity of rat cerebral cortex neurons (CX). ME slowed discharge in 65% of the 62 CX tested; activity evoked by acetylcholine (ACh) or glutamate, as well as spontaneous discharge, was affected. The vast majority of responsive cells were deeper than 500 μ and excited by ACh. Antidromic spikes were elicited in many of these neurons by pyramidal tract stimulation. The electrophysiological effects of D-Ala2 ME amide, a more potent analog in vitro, was similar to ME when tested on the same parietal CX, however, D-Ala2 ME amide was much more potent than ME on frontal CX. On the other hand N-acetyl D-Ala2-Lys3 ME amide, which has low potency in vitro, had little effect on CX which were readily depressed by equivalent doses of ME or the D-Ala2 analog. The depressions induced by ME or the D-Ala2 derivative were readily and reversibly antagonized by prior iontophoretic administration of naloxone. It is concluded that opiate receptor interactions may play an important role in electrophysiological responses to iontophoretically administered ME and that the deeper cholineceptive cortical cells, possibly pyramidal neurons, may be preferentially affected.
Ganomalite from Franklin, New Jersey, and Jakobsberg, Sweden: new chemical and crystallographic data

Chemical analyses for ganomalite from Franklin, New Jersey, and Jakobsberg, Nordmark, Sweden, imply that Mn is an essential element and that the formula is Pb9Ca5MnSi9O33, with Z = 1 for the hexagonal unit cell. Preliminary crystal structure data confirm that Mn and Ca are ordered, as implied by the chemical analyses. Ganomalite is hexagonal, space group P3, with a = 9.82 and c = 10.13 A. Occurrences of samples from both localities are described, together with analytical data for macedonite from Jakobsberg.
Permeability of human synovial membrane to plasma proteins. Relationship to molecular size and inflammation

Passage of plasma proteins from blood into synovial fluid was found quantitatively related to molecular size and to degree of inflammation in four groups of patients differing in severity of synovial inflammation, and in a group of autopsied subjects without joint disease. Greater inflammation was accompanied by augmented passage of each protein across the synovial membrane, and by proportionately greater increase in permeability to larger proteins. In classic rheumatoid arthritis, synovial IgM and IgG concentrations were higher than predicted from the above-described interrelationships, suggesting local immunoglobulin synthesis.
Chromatographic purification of tritiated steroids prior to use in radioimmunoassay

Abstract The purity of tritiated steroids used as reagents in radio immunoassay plays an important role in the reliability of the assay. These radioactive reagents should be assessed for purity upon receipt and the purity should be checked periodically afterward. For such purposes, we have used chromatographic purification on Celite microcolumns. By charging the polarity of the stationary and mobile phases, 20 different tritiated steroids with a wide range of polarity could be purified on these microcolumns. This approach is easy, rapid, economical, and reliable.
Acoustic wave propagation predictions based on two different particle/fluid two-phase flow models

Abstract Acoustic wave propagation predictions are reported based on two frequently used models of particle/fluid two phase flow. It is shown that the predictions of one model are qualitatively correct while those of the other are qualitatively incorrect. These results provide a concrete example of the extreme sensitivity of two phase flow predictions to modeling assumptions.
Molecular Dynamics Simulation Study of T Cell Receptor Molecular Recognition of Peptide-Major Histocompatibility Complexes

An important early molecular recognition event that triggers T cell mediated immune responses is the interaction of a T cell receptor (TCR) on the surface of the T cell with a heterodimeric complex displayed on the surface of pathogen-infected cells. This heterodimeric complex consists of a peptide, 8-10 amino acids in length, bound to the highly polymorphic major histocompatibility complex (MHC). A TCR binds to this heterodimeric complex (peptide-MHC) with sufficient affinity only if interactions between the TCR and certain key regions located on both the MHC and the bound peptide are favorable. On the MHC, these key regions or “hotspots” are restricted to just a few amino acids. The molecular mechanisms by which mutations of these MHC “hotspot” residues influence TCR/peptide-MHC binding are not well understood.Molecular Dynamics simulations coupled with free energy calculations based on the inverse form of the Potential Distribution Theorem were carried out to evaluate the effect of single-amino acid mutations of the MHC “hotspot” residues on the binding affinity of the A6 TCR to the HLA-A2 MHC complexed with the Tax peptide of the Type I T lymphotropic virus. In agreement with experimental observations, this analysis reveals a strong influence of the MHC “hotspot” residue mutations on TCR/peptide-MHC binding affinity. Also, the changes in TCR binding affinities resulting from the MHC “hotspot” mutations are compared to those resulting from mutations of key amino acids in the bound peptide of the peptide-MHC complex in order to provide a quantitative comparison of the relative contributions of the peptide and the MHC to the TCR binding affinity. These comparisons permit a detailed thermodynamic analysis of the effect of mutations on TCR molecular recognition of peptide-MHCs.
Calcium-dependent fast depolarizing afterpotentials in vasopressin neurons in the rat supraoptic nucleus.

Oxytocin (OT) and vasopressin (VP) synthesizing magnocellular cells (MNCs) in the supraoptic nucleus (SON) display distinct firing patterns during the physiological demands for these hormones. Depo...
Analyzing and Implementing a Feature Mapping Approach to CAD System Interoperability

Interoperable information exchange between computer-aided design (CAD) systems is one of the major problems to enable information integration in a collaborative engineering environment. Although a significant amount of work has been done on the extension and standardization of CAD data formats as well as the cooperation of CAD systems in both academy and industry, these approaches are generally low-level and narrowly targeted. Lack of fundamental study of interoperability and generic solution to this problem is the major issue. Our intention of this research is to design a solution of CAD feature interoperability as generic as possible based on a theoretical foundation of language types. In this paper, we present a fundamental model of semantic features and feature mapping process based on the type theory. We implement and demonstrate our approach for automated feature exchange between commercial CAD systems.Copyright © 2009 by ASME
Analyzing Ultimatum Bargaining: A Bayesian Approach to the Comparison of Two Potency Curves Under Shape Constraints

An experiment designed to test whether experimenter observation influences play of the ultimatum game led to a comparison of proportions of perfect equilibria obtained under different conditions. Our analysis features a Bayesian approach to this comparison. Our method extends recent work in the nonparametric Bayesian analysis of bioassay problems when the prior constrains the form of the potency curve. Sampling-based approaches to calculating posterior features of interest are used and discussed. We conclude that experimenter observation has a small influence but not enough to account for most of the deviation from perfect-equilibrium play.
Slavery in the Great Lakes Region of East Africa

edited by Henri Medard & Shane Doyle, Oxford, James Currey, 2007, xiv, 273 pp., £55.00 and £17.95. ISBN 978-1-84701-602-7 (cloth); 978-1-84701-603-4 (paper). The Great Lakes region of East Africa i...
Weighted bicubic spline interpolation to rapidly varying data

The weighted bicubic spline that is a C1 piecewise bicubic interpolant to three-dimensional gridded data is introduced. This is a generalization of the univariate weighted spline, developed by Salkauskas, in that a weighted minimization problem is solved. The minimization problem solved is a weighted version of the problem that the natural bicubic spline and Gordon's spline-blended interpolants minimize. The surface is represented as a piecewise bicubic Hermite interpolant whose derivatives are the solution of a linear system of equations. For computer-aided-design applications, the shape of the surface is controlled by weighting the variation over the individual patches, whereas many other shape-control methods weight the discrete data points. A method for selecting the weights is presented so that the weighted bicubic spline effectively solves the important and often difficult problem of interpolating rapidly varying data.
Importance of time to reperfusion for 30-day and late survival and recovery of left ventricular function after primary angioplasty for acute myocardial infarction

Abstract Objectives. The purpose of this study was to evaluate the importance of time to reperfusion for outcomes after primary angioplasty for acute myocardial infarction. Background. Survival benefit of thrombolytic therapy for acute myocardial infarction is strongly dependent on time to treatment. Recent observations suggest that time to treatment may be less important for survival with primary angioplasty. Methods. Consecutive patients (n = 1,352) with acute myocardial infarction treated with primary angioplasty were followed for up to 13 years. Paired acute and follow-up ejection fraction data were obtained at cardiac catheterization in 606 patients. Results. Reperfusion was achieved within 2 h in 164 patients (12%). Thirty-day mortality was lowest with early reperfusion (4.3% at 6 h). Thirty-day–plus late cardiac mortality was also lowest with early reperfusion (9.1% at 6 h). Improvement in left ventricular ejection fraction was greatest in the early reperfusion group and relatively modest after 2 h (6.9% at Conclusions. Time to reperfusion, up to 2 h, is important for survival and recovery of left ventricular function. After 2 h, recovery of left ventricular function is modest and survival is relatively independent of time to reperfusion. These data suggest that factors other than myocardial salvage may be responsible for survival benefit in patients treated with primary angioplasty after 2 h.
The effect of dimethylsulfoxide on the tegumental brush border of the cestode Hymenolepis diminuta.

Dimethyl sulfoxide (DMSO), commonly used for cryoprotection or for the solvation of cytoskeleton-modifying drugs, causes changes in the topology of the plasma membrane of the tegumental brush border in the tapewormHymenolepis diminuta; however, relatively long exposures or high concentrations are required. In tapeworms treated with DMSO concentrations of ≥1% in the present study, the interaction of the tegumental surface membrane with the underlying cytoskeleton may have been disrupted at focal points in the brush border, resulting in a partial loss of the membrane anchoring required for the structural integrity of the brush border. Blebbing of the tegumental surface was prominent only after exposure to 1% DMSO for 20 h in vitro culture with RPMI 1640, and vesiculation of the membrane along the microvillar (microtriche) shafts, which may have been related to the in vitro conditions, was amplified by the presence of concentrations of ≥1% DMSO in the incubation medium. The tegumental response to DMSO was not uniform but regional, consistently appearing to be more prevalent on the distal aspects of each proglottid rather than on the edge proximal to the scolex. Blebbing and vesiculation were not seen on the basal aspect of the tegument, including the basal ectocytoplasmic plasma membrane, the perikarya, and the internuncial processes. Microvillar core bundles of actin microfilaments persisted following 8 h in vitro exposure to all three concentrations of DMSO tested (0.1%, 1%, 5%); however, only in tapeworms that were treated in vitro with 5% DMSO for ≥ 8 h did core microfilament bundles appear to lose the rigidly straight and parallel organization characteristic of control tapeworms that were incubated either in the absence of DMSO or with 0.1% DMSO. Other components of the brush border cytoskeleton (i.e., microvillar caps, junctional tubules, and tunics) appeared unaffected by DMSO except at foci where blebbing occurred. These data suggest that in vitro concentrations of <1% DMSO have little observable effect on the anchoring of the tegumental surface membrane to the underlying cytoskeleton or the organization of the microfilamentous cytoskeleton of the brush border microvilli. The present investigation thus provides baseline data on DMSO-induced artifact for future studies that require the use of DMSO but do not focus on its effects.