cssi/SciSciGPT-SciSciNet huggingface dataset:
DIAGNOSIS AND DIFFERENTIAL DIAGNOSIS OF MULTIPLE SCLEROSIS

The criteria of the Schumacher committee appear to be the most practical set of requirements for the clinical diagnosis of multiple sclerosis. Multiplicity in both time and space are essential for this disease. A combination of optic nerve involvement, long-tract signs and evidence of brain-stem dysfunction is a constellation which is most likely to be due to multiple sclerosis in young individuals. Even here though, other disorders need be kept in mind: Leber's optic atrophy, heredofamilial spinocerebellar degenerations, nutritional disorders, ischemic and inflammatory vascular disease. When the eye is not involved, one need also consider Behcet's disease and other chronic meningoencephalitides. Regardless what the course of illness has been, a lack of spatial dissemination within the central nervous system precludes a diagnosis of MS. Brain stem or spinal cord disorders are notorious for causing disturbances suspicious of multiple lesions when in fact a single local lesion is operative. Early development of dementia or seizures, or the presence of extrapyramidal signs, stupor, aphasia, or focal atrophy with fasciculations is in each instance most unusual in MS.
Modulation of 3-hydroxy-3-methyl glutaryl CoA reductase by 2,3-diphosphoglyceric acid

Rat liver microsomal 3-hydroxy-3-methylgularyl CoA (HMG-CoA) reductase was activated by 50% at a concentration of 0.4 mM 2,3-diphosphoglyceric acid (DPG) and by 11-fold at 10 mM DPG. DPG also prevented the inactivation of HMG-CoA reductase by ATP and Mg++. Rat liver microsomal HMG-CoA reductase prepared in the presence of 1 mM DPG was significantly more active than when prepared in the absence of DPG. Activation of the enzyme by DPG and protection of the enzyme against inhibition by ATP and Mg++ by DPG were also observed with solubilized HMG-CoA reductase.
An 18O/16O and D/H study of Tertiary hydrothermal systems in the southern half of the Idaho batholith

During Eocene time, 37 to 49 m.y. ago, a series of large hydrothermal systems was developed around a group of epizonal granite plutons in the Idaho batholith. These systems involved deep and extensive circulation of fluids derived from low-δ 18 O (∼−16) and low-δD (∼−120) meteoric waters. Water-rock interactions occurred at temperatures of 150 to 400 °C, lowering the 18 O/ 16 O and D/H ratios in the surrounding Mesozoic rocks (tonalite, granodiorite, and granite), such that the feldspar δ 18 O and biotite δD values became as low as −8.2 and −176, respectively. These values contrast markedly with the primary isotopic compositions of +9.3 ± 1.5 and −70 ± 5, respectively. Widespread propylitization of the Mesozoic plutonic rocks accompanied these isotopic exchange effects. Systematic mapping shows that anomalous δD and δ 18 O values occur over more than 15,000 km 2 , indicating the extensive lateral dimensions of the ancient circulating systems. The former zones of intense hydrothermal activity are marked by low- 18 O zones, which were mapped in the vicinity of the margins of several Eocene plutons (for example, at Rocky Bar) and also within a giant (5- to 20-km wide, 60- to 40-km diam) ring zone that surrounds the Sawtooth Mountains. The latter anomaly is coincident with the high-permeability ring fracture zone of an Eocene caldera system. Most of the ore deposits in the southern half of the Idaho batholith are epithermal and mesothermal Au-Ag veins that are located near the periphery of the low- 18 O zones (that is, near the outermost δ 18 O = 8 isopleth). This association links these deposits with the Tertiary hydrothermal activity and has great potential as an exploration tool in the heavily forested region. Evidence is presented that the Eocene ground-water circulation pattern was affected over large lateral distances (25 to 50 km) and great depths (5 to 7 km). These conclusions, together with the indications that large amounts of water (> 7,000 km 3 ) were involved in some systems and that the circulation patterns probably are related to caldera ring structures, may be of particular importance in geothermal exploration and exploitation of analogous modern systems. For example, the “fossil” hydrothermal activity mapped in the Idaho batholith may be characteristic of deep-level fluid circulation in geothermal systems such as Yellowstone National Park, Wyoming. In such regions, the major zones of hydrothermal activity seem to be principally associated with either (1) the caldera ring zones or (2) the central plutons (resurgent domes).
A numerical method for phase-change problems

A highly accurate and efficient finite-difference method for phase-change problems with multiple moving boundaries of irregular shape is developed by employing a coordinate transformation that immobilizes moving boundaries and preserves the conservative forms of the original governing equations. The numerical method is first presented for one-dimensional phase-change problems (involving large density variation between phases, heat generation, and multiple moving boundaries) and then extended to solve two-dimensional problems (without change of densities between phases). Numerical solutions are obtained non-iteratively using an explicit treatment of the interfacial mass and energy balances and an implicit treatment of the temperature field equations. The accuracy and flexibility of the present numerical method are verified by solving some phase-change problems and comparing the results with existing analytical, semi-analytical and numerical solutions. Results indicate that one- and two-dimensional phase-change problems can be handled easily with excellent accuracies.
The production of amorphous regions in carbon nanotubes by 140 keV He ion irradiation

Abstract The production of amorphous regions in carbon nanotubes irradiated with 140 keV He ions was studied using Raman spectroscopy and transmission electron microscopy (TEM). Intensity ratios of Raman D to G bands ( I D / I G ) initially increase and then decrease as a function of ion fluence at all investigated irradiation temperatures (room temperature, 200 and 400 °C). The critical ion fluences corresponding to the maximum in I D / I G ratios increase with increasing irradiation temperature because of the enhanced defect annealing. The displacement per atom (dpa) values, consistent with a maximum in I D / I G ratios, are determined to be 0.15 dpa at room temperature and 200 °C, and 0.3 dpa at 400 °C. TEM examination of all irradiated specimens supports Raman results indicating that the maximum in I D / I G correlates to the formation of amorphous regions. The study shows that after formation of amorphous regions at high fluences, I D / I G ratio can be no longer used to measure amorphous/graphitic content in CNTs.
Effect of the synthetic method and support porosity on the structure and performance of silica‐supported CuBr/pyridylmethanimine atom transfer radical polymerization catalysts. II. Polymerization of methyl methacrylate

A systematic study of the effect of the synthesis method and catalyst structure on the atom transfer radical polymerization (ATRP) performance of copper(I) bromide/pyridylmethanimine complexes supported on silica is described. Four different synthetic routes, including multistep-grafting (M1), two-step-grafting (M2), one-pot (M3), and preassembled-complex (M4) methods, have been evaluated on three different silica supports (mesoporous SBA15 with 48- and 100-A pores and nonporous Cab-O-Sil EH5). The resulting solids have been used for ATRP of methyl methacrylate. The catalysts allow for moderate to poor control of the polymerization, with polydispersity indices (PDIs) ranging from 1.46 to greater than 2. The materials made with the preassembled-complex (M4) and one-pot (M3) approaches are generally more effective than those prepared with a grafting method (M1 and M2) on porous silica, whereas all the methods provide similarly performing catalysts on the nonporous support. Nonporous Cab-O-Sil EH5 is the most effective support because of its small particle size, lack of porosity, and relative compatibility in the reaction media. All the catalysts leach copper into solutions in small amounts. In addition, the catalysts can be effectively recycled, with improved controlled character in recycle runs (PDI ∼ 1.2). Control experiments have shown that this improved performance of the used catalysts is likely due to the presence of a soluble Cu(II) complex in the materials that effectively deactivates the growing polymer chain, leading to narrow PDIs and controlled molecular weights. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1384–1399, 2004
Learning computer science in the "comfort zone of proximal development"

As computer science faculty, we are always looking for better ways to recruit and retain new majors. One way to achieve this goal is to incorporate material into the introductory courses that lies within the intersection of the student's "zone of proximal development" (which contains concepts that the student is capable of understanding) and "comfort zone" (which contains concepts that motivate the student and are presented in a way in which the student is familiar and comfortable). We refer to this region as the "comfort zone of proximal development." In this paper, we present a "comfort zone of proximal development" that we have created for computer science students which consists of a collaborative learning environment where programming concepts are introduced with gaming applications.
On why Collet's doubts regarding the PCA are misplaced

Collet's (1989) doubts regarding the efficacy of principal component analysis (PCA) as a tool in the study of event-related brain potentials (ERPs) are unpersuasive. The substantive point reported by Collet is that data points are autocorrelated over the time period during which a single, PCA-defined, ERP component predominates. Such autocorrelation has long been recognized by investigators in the field, and its confirmation by autoregressive modeling does not provide useful information about issues central to ERP data analysis. Furthermore, because he fails to take a full count of the number of parameters used in his autoregressive model his argument from parsimony is flawed. In any event, Collet's argument misperceives the heuristic mode in which PCA is used in actual studies.
Structure and Biosynthesis of Free Lipid A Molecules That Replace Lipopolysaccharide in Francisella tularensis subsp. novicida

Francisella tularensis subsp. novicida U112 phospholipids, extracted without hydrolysis, consist mainly of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, and two lipid A species, designated A1 and A2. These lipid A species, present in a ratio of 7:1, comprise 15% of the total phospholipids, as judged by 32Pi labeling. Although lipopolysaccharide is detectable in F. tularensis subsp. novicida U112, less than 5% of the total lipid A is covalently linked to it. A1 and A2 were analyzed by electrospray ionization and matrix-assisted laser desorption ionization mass spectrometry, gas chromatography/mass spectrometry, and NMR spectroscopy. Both compounds are disaccharides of glucosamine, acylated with primary 3-hydroxystearoyl chains at positions 2, 3, and 2' and a secondary palmitoyl residue at position 2'. Minor isobaric species and some lipid A molecules containing a 3-hydroxypalmitoyl chain in place of 3-hydroxystearate are also present. The 4'- and 3'-positions of A1 and A2 are not derivatized, and 3-deoxy-d-manno-octulosonic acid (Kdo) is not detectable. The 1-phosphate groups of both A1 and A2 are modified with an alpha-linked galactosamine residue, as shown by NMR spectroscopy and gas chromatography/mass spectrometry. An alpha-linked glucose moiety is attached to the 6'-position of A2. The lipid A released by mild acid hydrolysis of F. tularensis subsp. novicida lipopolysaccharide consists solely of component A1. F. tularensis subsp. novicida mutants lacking the arnT gene do not contain a galactosamine residue on their lipid A. Formation of free lipid A in F. tularensis subsp. novicida might be initiated by an unusual Kdo hydrolase present in the membranes of this organism.
Dependence of transcription-coupled DNA supercoiling on promoter strength in Escherichia coli topoisomerase I deficient strains.

Abstract Transcription by RNA polymerase can induce the formation of hypernegatively supercoiled DNA in vitro and in vivo . This phenomenon has been nicely explained by a “twin-supercoiled-domain” model of transcription where a positively supercoiled domain is generated ahead of the RNA polymerase and a negatively supercoiled domain behind it. In Escherichia coli topA strains, DNA gyrase selectively converts the positively supercoiled domain into negative supercoils to produce hypernegatively supercoiled DNA. In this article, in order to examine whether promoter strength affects transcription-coupled DNA supercoiling (TCDS), we developed a two-plasmid system in which a linear, non-supercoiled plasmid was used to express lac repressor constitutively while a circular plasmid was used to gage TCDS in E. coli cells. Using this two-plasmid system, we found that TCDS in topA strains is dependent on promoter strength. We also demonstrated that transcription-coupled hypernegative supercoiling of plasmid DNA did not need the expression of a membrane-insertion protein for strong promoters; however, it might require co-transcriptional synthesis of a polypeptide. Furthermore, we found that for weak promoters the expression of a membrane-insertion tet gene was not sufficient for the production of hypernegatively supercoiled DNA. Our results can be explained by the “twin-supercoiled-domain” model of transcription where the friction force applied to E. coli RNA polymerase plays a critical role in the generation of hypernegatively supercoiled DNA.
Endogenous protein kinase-C activation in osteoblast-like cells modulates responsiveness to estrogen and estrogen receptor levels

The osteoblast-like osteosarcoma cell line ROS 17/2.8, which expresses very low levels of estrogen receptor (ER), was stably transfected with the mouse ER in order to more easily evaluate the physiological role of estrogens in bone cell homeostasis. These transfected ROS.SMER 14 cells are highly responsive to estrogenic stimulation at subconfluence, but become refractory to estrogenic stimulation when postconfluency is reached. The purpose of these studies was to determine the mechanisms underlying this loss of responsiveness in these ER stably transfected cells at postconfluence. When proliferative capacity was evaluated by bromodeoxyuridine immunocytochemistry, approximately 70% of the subconfluent cells were actively dividing, whereas none of the postconfluent cells underwent division. Subconfluent cells were found to contain 2500-3000 ER-binding sites/cell, whereas the ER in postconfluent cells was low and often undetectable. Steady state ER mRNA levels were not significantly modified by postconfluency. ER protein levels were also unaffected by confluency status. Since protein kinase-C (PKC) has been reported to influence cell proliferation and steroid hormone receptor binding, PKC activity was measured in sub- and postconfluent cells. Calcium-dependent PKC activity was approximately about 2-fold higher in postconfluent compared to subconfluent cells, whereas no differences were discerned in calcium-independent PKC activity. In an effort to examine the role of PKC in greater detail, postconfluent cells were treated with PKC inhibitors (H-7 or staurosporine) or with the tumor promoter TPA (12-O-tetradecanoylphorbol-13-acetate) to down-regulate PKC activity, and changes in ER were evaluated. Inhibition or down-regulation of the PKC activity in postconfluent cells enhanced ER-binding capacity in a dose-dependent manner and estrogen responsiveness of an exogenous reporter gene and of the endogenous alkaline phosphatase, representing an endogenous estrogen-stimulated gene. These data indicate that there is an interaction between the PKC and ER signaling systems in bone cells and that this interaction may be influenced by the proliferative and/or differentiative state of the cells, resulting in modulation of hormone responsiveness.
Thermal Design Criteria for Extraordinary Performance of Devices Cooled by Microchannel Heat Sink

Increasing power dissipation in microprocessors and other devices is leading to the consideration of more capable thermal solutions than the traditional air-cooled fin heat sinks. Microchannel heat sinks (MHSs) are promising candidates for long-term thermal solution given their simplicity, performance, and the development of MHS-compatible 3D device architecture. As the traditional methods of cooling generally have uniform heat removal on the contact area with the device, thermal consequences of design have traditionally been considered only after the layout of components on a device is finalized in accordance with connection and other criteria. Unlike traditional cooling solutions, however, microchannel heat sinks provide highly nonuniform heat removal on the contact area with the device. This feature is of utmost importance and can actually be used quite advantageously, if considered during the design phase of a device. In this study, simple thermal design criteria governing the general placement of components on devices to be cooled by microchannel heat sink are developed and presented. These thermal criteria are not meant to supersede connection and other important design criteria but are intended as a necessary and valuable supplement. Full-scale numerical simulations of a device with a realistic power map cooled by microchannel heat sink prove the effectiveness of the criteria, showing large reduction in maximum operating temperature and harmful temperature gradients. The simulations further show that the device and microchannel heat sink can dissipate a comparatively high amount of power, with little thermal danger, when design considers the criteria developed herein.
Allosteric effects of a GABA receptor-active steroid are altered by stress.

Abstract Recently, ring A reduced metabolites of naturally occurring steriods have been shown to act as allosteric modulators of GABA-gated chloride ion conductance. Specifically, 5α-pregnance-3α,21-diol-20-one (allotetrahydrodeoxycorticosterone; 5α-THDOC) was shown to be a positive allosteric effector. For example, 5α-THDOC enhances the specific binding of [3H]flunitrazepam, a benzodiazepine receptor agonist, among other pharmacological actions. Swim stress has been shown to reduce the ability of flurazepam, a prototypic benzodiazepine agonist, to antagonize the electrical precipitation of tonic hindlimb extension in mice. This stress-induced reduction in flurazepam's antiseizure efficacy persists for up to 72 h and is associated with alterations in the specific binding of ligands to the GABAA receptor complex. In the current study, the potentiation of [3H]flunitrazepam binding by 5α-THDOC was greater in cerebral cortical membranes prepared from stressed mice compared with unstressed controls. Moreover, nanomolar concentrations of 5α-THDOC that were ineffective in potentiating the specific binding of [35S]TBPS in cerebral cortical membranes prepared from unstressed control mice were capable of potentiating this binding in membranes prepared from stressed animals. Specifically, 50 nM 5α-THDOC caused a 23% increase in the specific binding of [35S]TBPS in membranes from stressed mice, whereas it was without any significant effect in unstressed controls. This apparent ability of 5α-THDOC to distinguish between the binding of [35S]TBPS to crude membranes prepared from stressed and unstressed control mice was eliminated in the presence of a 5 μM concentration of GABA. The data are consistent with an effect of stress on the ability of a GABA-positive steroid to allostetically modulate the binding of both a benzodiazepine agonist and GABAA-associated channel ligand. These data provide additional support for a stress-induced alteration of the GABAA receptor complex.
Controlling the optical wave propagation using engineered nanoscale metasurfaces

We present ultrathin plasmonic reflectarray metasurfaces for arbitrary shaping of the wave phase front at infrared and optical frequencies. The metasurface building blocks are designed exploiting nanocircuit concepts, offering high controllability and low loss. We present a fast and accurate analytical model to tune the metasurface and achieve large conversion efficiency over a broad angular range and moderately broad bandwidth of operation. We suggest the application of these concepts for light manipulation, trapping and harvesting in solar cells technology.
Consistent Boundary Conditions for Multicomponent Real Gas Mixtures Based on Characteristic Waves

Previously developed characteristic-wave-based boundary conditions for multicomponent perfect gas mixtures are here extended to real gas mixtures. The characteristic boundary conditions are derived from the one-dimensional wave decomposition of the Euler equations, and the wave amplitude variations are determined from the prescribed boundary conditions on the flow variables. The viscous conditions are applied separately. For multidimensional simulations, the boundary conditions for each coordinate direction are applied additively. These boundary conditions are tested on a representative two-dimensional problem?the propagation of an incompressible vortex by a supersonic flow with outflow conditions specified as nonreflecting?solved using a high-order finite-difference scheme. Simulations conducted for a heptane?nitrogen mixture flow with strong real gas effects display excellent, nonreflective wave behavior as the vortex leaves the computational domain, verifying the suitability of this method for the multidimensional multicomponent real gas flows computed.
Phase transformations in sputtered Ni-Mn-Ga magnetic shape memory alloy thin films

Abstract Ni–Mn–Ga magnetic shape memory alloy films have been prepared by the DC magnetron sputtering technique. As-deposited films show a quasi-amorphous structure that crystallizes at ~ 500 K. Crystallization study using Kissinger's analysis reveals a relatively low activation energy indicating partial crystallinity in the films. In situ X-ray diffraction studies show reversible martensite phase transformations, and phase segregation to non-transforming L1 2 precipitates at higher temperatures. It was observed that the phase segregation can be suppressed by low temperature heat treatment.
Going Blood-Simple in Poisonville Hard-Boiled Masculinity in Dashiell Hammett’s Red Harvest

This article examines the representation and critique of what it terms hard-boiled masculinity as an exemplary form of modern masculinity in Dashiell Hammett’s Red Harvest. The novel presents hard-boiled masculinity as violent, rationalized, and largely purged of interiority and affect. Its representation of masculinity is organized around a form of split narration in which the affective detachment and seeming rationality of the firstperson narration produces a textual unconscious in which the affect purged fromthe surface of the narrative is projected on to and returns in the shape of various gendered, racialized, and nationalized others. After explicating this split narration, and suggesting its links to the advent of Taylorism and incipient Fordism in the 1920s, the article charts the political costs of this displacement of affect and the form of masculinity it constructs.
Correlating the Kinetics of Cytokine-Induced E-Selectin Adhesion and Expression on Endothelial Cells

Many human diseases are mediated through the immune system. In chronic inflammatory disorders, the processes ordinarily involved in tissue healing become destructive. Endothelial cells normally recruit leukocytes to inflamed tissue using cytokine-induced adhesion receptors on the surfaces of interacting cells. Leukocyte capture depends on specialized characteristics of these receptors, particularly the binding kinetics. This study is designed to clarify the relationship between cytokine-induced changes in cell properties and binding kinetics. Here, we measure the kinetics of expression and monoclonal antibody binding for E-selectin in interleukin-1alpha-stimulated microvascular endothelium in vitro and incorporate the data into kinetic models. Quantitative flow cytometry is used to determine molecular density (expression), and micropipette assays are used to find the probability of adhesion (function). Within five hours of interleukin-1alpha stimulation, E-selectin density increases from 0 to 742 sites/microm(2), and antibody-E-selectin adhesion probability increases from a baseline of 6.3% to 64%. A kinetic model is applied to find an apparent association rate constant, k(f), of 3.7 x 10(-14) cm(2)/sec for antibody-E-selectin binding. Although the model successfully predicts experimental results, the rate constant is undervalued for a diffusion-limited process, suggesting that functional adhesion may be modified through cytokine-induced changes in microtopology and receptor localization.
Measuring the Effects of Initiating Body Checking at the Atom Age Level

The purpose of this study was to determine the effects of initiating body checking at the Atom age level. The study used an experimental design in which teams from the Ottawa District Minor Hockey Association (ODMHA) represented the control group, while teams from the Ontario Hockey Federation (OHF) represented the treatment group. The study was conducted over a 3-year period from 1998 to 2001. The comparison sampling between the two leagues was as follows: ODMHA Yr1 = 69 teams versus OHF Yr1 = 74 teams, ODMHA Yr2 = 59 teams versus OHF Yr2 = 101 teams, ODMHA Yr3 = 46 teams versus OHF Yr3 = 90 teams. Measures of interest reported here included player selection bias, injury incidence, and variables that describe the characteristics of the flow of the game such as goals for, goals against, and number of penalties. Athlete exposures for each league by year were computed using 15 players per team for a 20 game plus 20 practice schedule. Statistical analysis of the difference in proportions of injuries reported by the two leagues based on the CHA injury insurance dataset showed that no significant difference occurred per year of the study. In addition, the rates of injuries were lower in each year than those reported by previously published studies. Body checking, which includes body contact is considered by many to be a skill within the game of ice hockey that can be taught at the younger age levels in a manner that does not lead to a higher incidence of injuries, or unfavorable changes in the game. The results of this study support that contention. In the present study, it was assumed that education was an essential component of the introduction process and that coaches were provided the necessary background to enable them to teach the introduction of body checking as a skill.
In‐situ measurement of soil moisture at the KUREX‐91 Streletskaya steppe sites

Measurements were obtained at Kursk Biospheric Reserve Station (BRS) throughout the period from 6 July through 27 July, 1991. Both gravimetric and dielectric measurements were obtained daily for all sites on the steppe. Soil sampling points were selected near each corner of the three sites (i.e. southeast, southwest, northwest, and northeast field corners). This scheme was slightly modified for the primary site, field 12, to achieve better coincidence with Soviet measurements. The moisture content of the top 10 cm of soil was examined by extracting a cylindrical core approximately 2cm in diameter and 10cm long at four sampling locations in each of the three test sites/fields. Two cores were extracted from each sampling location and combined in a single sampling container for subsequent gravimetric analysis. These samples were weighed in the laboratory several hours after being obtained and placed in drying ovens at a temperature of 110°C for approximately 48 h. Dry weights were then obtained and the origi...
Methods in Sinology: Problems of Teaching and Learning

Even as recently as a dozen years ago, one learned basic Sinological methods rather much the way one learned about sex: by osmosis and “from the gutter.” One puzzled over the remarks of his professors, looked up the strange words in the dictionary, and listened to the older boys in the hall. “I got it from the Kanshi taikan,” some graduate student would say, and you made a mental note to ask a friend about the Kanshi taikan the next time you could be alone together. For all the limitations, it was a pleasant and reasonably effective way to learn Sinology. The atmosphere was clubby, the pace was slow, and there was usually time for patient professional attention.
RC+ gene-dependent inhibition of RNA synthesis without ppGpp accumulation

Summary The lack of a required amino acid or a block in the synthesis of an aminoacyl-tRNA inhibits net RNA synthesis and results in the accumulation of the nucleotides ppGpp and MS II in RC + but not in RC − cells of E. coli. It would be conceivable that ppGpp is the mediator of the inhibition of net RNA synthesis by the RC + control system. However, the following results indicate that this is not (or at least not always) the case: Trimethoprim, an inhibitor of the formation of the peptide chain initiator formylmethionyl-tRNA f , blocks net RNA synthesis in RC + but not in RC − cells. We found that in RC + E. coli cells, trimethoprim (i) does not cause ppGpp or MS II accumulation if no required amino acid is missing, and (ii) does not inhibit ppGpp accumulation elicited by the lack of a required amino acid.
Decentralized Control for a Swarm of Vehicles Performing Source Localization

In this paper, decentralized feedback controls are presented for a swarm of autonomous, robotic vehicles that is tasked with localizing a stationary, time-invariant source. The development of the feedback controls is motivated by classic function-minimization theory and the method is actually suited for a large collection of agents, where collection of agents may refer to, for example, a population of N design points in some variable space. We present the theory that supports the method, some example problems and their simulations to illustrate the method, and discuss some potential applications.
A molecular orbital study of ethylene and the all-trans conjugated polyenes: C4H6, C6H8, C8H10 and C10H12

Abstract We have carried out calculations on ethylene, trans 1,3-butadiene and on all-trans 1,3,5-hexatriene, 1,3,5,7-octatetraene and 1,3,5,7,9-decapentaene at the 6-31G level, on 1,3-butadiene and 1,3,5-hexatriene at the 6-31G* level, and on 1,3-butadiene at the 6-311G** level, with full geometry optimization. As the chain length is increased, the terminal CC bond shows an increase in length, the adjacent CC bond a decrease, the next CC bond along the chain an increase, and the next CC bond a decrease, the change in each case tending towards a limiting value. The terminal CC bond is shorter than the others, and the CC bond next to the end is longer than the others. The HC bonds in the middle of the longer chains also show a progressive increase towards a limiting value. The terminal C-atoms serve as both σ- and π-charge acceptors, whereas the other C-atoms are σ-charge acceptors but π-charge donors. The σ-charge transfer tends to level off at a value of about −0.182 in the middle of the chain, while the π-charge transfer drops almost to zero. The total overlap populations between the C-atoms of the CC and CC bonds are larger the shorter the bond length, and vice-versa, following straight line relationships. The breakdown of the total overlap population into contributions from atom centers, proximal and distal bonded atoms, and antibonded atoms, finds significant antibonded atom contributions amounting to 10–14% of that from proximal bonded atoms. Isodesmic bond separation energies and homodesmotic group separation energies are evaluated to assess the conjugation energy (stabilization energy) in the polyenes, and comparisons are made with the corresponding energies for benzene.
Energy gap and critical temperature in a resonating-valence-bond theory of high-T c superconductivity

The zero-temperature energy gap and the critical temperature are evaluated in mean-field approximations of a resonating-valence-bond theory of high-${T}_{c}$ superconductivity. The ratio of energy gap to ${T}_{c}$ is found to be small compared to the Bardeen-Cooper-Schrieffer value except for parameters when ${T}_{c}$ is very low.
Factors influencing environmental stewardship in U.S. agriculture: Conservation program participants vs. non-participants

United States Department of Agriculture (USDA) conservation policy has increasingly shifted from a traditional land-retirement focus to greater emphasis on producer adoption of working-land conservation practices. This research made use of USDA integrated field/farm surveys, the Conservation Effects Assessment Project (CEAP) and Agricultural Resources Management Survey (ARMS), to (1) enhance understanding of operator, field, farm, economic, and environmental characteristic differences between conservation program participants and non-participants across a farm typology, and (2) to enhance understanding of the relative importance of these factors on influencing farm stewardship intensity in corn and wheat production, i.e., how these factors influence differences in producer adoption of alternative levels of land and pest-management practices between conservation program participants and non-participants. The research used a cost-function acreage-based technology adoption model to examine farm stewardship differences. Results indicate that program non-participants invest more heavily in land conserving and pest-management practices than program participants. Relative prices, structural, and socio-environmental factors play significantly different roles across crops, and between conservation program participants and non-participants, in their influence on producer adoption decisions for land and pest-management intensity. The environmental effectiveness and cost efficiency of conservation programs will likely improve when their implementation more explicitly recognizes farm heterogeneity as well as differences in farmer motivations for stewardship investments. Recognizing these differences can help improve targeting of conservation incentive structures.
Substructure lattices of models of arithmetic

Abstract We completely characterize those distributive lattices which can be obtained as elementary substructure lattices of models of Peano arithmetic. Stated concisely: every plausible distributive lattice occurs abundantly. Our proof employs the notion of a strongly definable type in many variables. With slight modifications the method also yields a characterization of those distributive lattices which can be obtained uniformly by Gaifman's methods of definable and end extensional 1-types. As a special case this gives another proof of two conjectures involving finite distributive lattices and models of arithmetic posed by Gaifman and initially proved by Schmerl. We also show that every minimal type (in the sense of Gaifman) satisfies a strong partition property which we will call being “uniformly Ramsey”.
Reproduction in the rat on purified diets containing succinylsulfathiazole.

SummaryAdult rats maintained on a purified diet containing succinylsulfathiazole and supplemented with all the known vitamins except pteroylglutamic acid from one to 3 months before breeding showed impaired reproduction.
Conceptualizing spirituality in social work: How the metaphysical beliefs of social workers may foster bias toward theistic consumers

Abstract In spite of the growing interest in spirituality, little attention has been paid to how social workers’ metaphysical worldviews affect their conceptualization and subsequent operationalization of spirituality. This paper explores how the largely nontheistic worldviews of social workers inform their definitions of spirituality, which in turn fosters a systemic bias against the spirituality of consumers who hold theistic belief systems. Examples of how current definitions conflict with a theistic worldview are provided, and it is suggested that the operationalization of existing conceptualizations would yield biased measures that would preas‐sign theistic consumers a lower level of spirituality. Suggestions for addressing the problem conclude the paper.
Oxysterol-induced cell death in human leukemic T-cells correlates with oxysterol binding protein occupancy and is independent of glucocorticoid-induced apoptosis

In eukaryotic cells oxysterols inhibit cholesterol biosynthesis and cell growth. A potent oxysterol, 25-hydroxycholesterol, was used to investigate the biological effects of oxysterols on three clonal lines of either glucocorticoid-sensitive or -resistant CEM cells, human leukemic T-lymphocytes. In addition, the glucocorticoid sensitivity of an oxysterol-resistant CEM cell line was tested. Oxysterols blocked growth and caused the lysis of cells regardless of their glucocorticoid response. All cells studied herein possessed an oxysterol binding protein with high affinity for 25-hydroxycholesterol. For all clones grown in serum-free medium, the half-maximal cytolytic concentration of 25-hydroxycholesterol (20-40 nM) correlated with its affinity (Kd = approximately 31 nM) for this oxysterol binding protein. Both cholesterol and mevalonate reversed 25-hydroxycholesterol cytotoxicity; 3-6 microM cholesterol or 0.1 mM mevalonate decreased 60 nM 25-hydroxycholesterol cytotoxicity by 50%. This cholesterol or mevalonate reversal appeared possible even after several days of 60 nM oxysterol treatment. The protective effect of cholesterol could be overcome by increasing 25-hydroxycholesterol concentrations. Cholesterol and mevalonate did not prevent glucocorticoid-mediated lymphocytolysis. Furthermore, the oxysterol-resistant line was sensitive to dexamethasone lysis. These data support the hypothesis that oxysterols and glucocorticoids act independently to block the growth of human leukemic lymphoblasts.
Language Selection and Switching in Strasbourg

Language Selection and Switching in Strasbourg. Penelope Gardner-Chloros. Oxford Studies in Language Contact. Oxford: Clarendon Press, 1991. 218 pp. $67.00 (doth)
The messenger RNA encoding VGF, a neuronal peptide precursor, is rapidly regulated in the rat central nervous system by neuronal activity, seizure and lesion

The VGF gene encodes a neuronal secretory-peptide precursor that is rapidly induced by neurotrophic growth factors and by depolarization in vitro. VGF expression in the animal peaks during critical periods in the developing peripheral and central nervous systems. To gain insight into the possible functions and regulation of VGF in vivo, we have used in situ hybridization to examine the regulation of VGF messenger RNA by experimental manipulations, and have found it to be regulated in the CNS by paradigms that affect electrical activity and by lesion. Inhibition of retinal electrical activity during the critical period of visual development rapidly repressed VGF messenger RNA in the dorsal lateral geniculate nucleus of the thalamus. In the adult, kainate-induced seizures transiently induced VGF messenger RNA in neurons of the dentate gyrus, hippocampus, and cerebral cortex within hours. Cortical lesion strongly induced VGF messenger RNA in ipsilateral cortex within hours, and strongly repressed expression in ipsilateral striatum. Ten days postlesion there was a delayed induction of VGF messenger RNA in a portion of deafferented striatum where compensatory cortical sprouting has been detected. Expression of the neuronal secretory-peptide precursor VGF is therefore modulated in vivo by monocular deprivation, seizure, and cortical lesion, paradigms which lead to neurotrophin induction, synaptic remodeling and axonal sprouting.
Estado pós-nacional e ampliação da liberdade do cidadão na Europa contemporânea

Se fora do organismo politico, qualquer que seja, nao ha significado nem dignidade para o homem, como defende Hannah Arendt, e preciso que esta vivencia politica nao se converta em totalitarismo, garantindo a liberdade e a pluralidade de valores na sociedade. O Estado, como organizacao politica, deve estar estruturado de maneira a tutelar a liberdade do homem. Hoje, ve-se um enfraquecimento do modelo do Estado-nacao. Por um lado, ha desafios que ultrapassam a possibilidade de uma solucao nacional, como nas areas da seguranca e da economia. Por outro, ha os anseios a uma liberdade que desconheca fronteiras territoriais e se materialize atraves de uma cidadania transnacional. Ganha revelo, assim, a ideia de um novo modo de organizacao politica desvinculada do nacionalismo, capaz de potencializar a liberdade - o Estado pos-nacional.
EMPATHY AND SECOND LANGUAGE LEARNING1

The study reported here represents the culmination of the development and application of a research strategy whereby hypotheses generated in the clinical circumstance are transposed to a behavioral realm where more rigorous, reproducible, reliable, and valid experimentation is feasible (Guiora 1970). Our concern has chiefly been to apply this strategy to the concept of empathy, choosing as the transposed realm of behavior, language, in particular, authenticity of pronunciation of a second language. In a series of studies we investigated the hypothesis that empathy plays a significant role in the ability to authentically pronounce a second language. The measure which proved to be most successful in predicting authenticity of pronunciation was the Micro-Momentary Expression (MME) test as modified by us. The present study confirms the original hypothesis that empathy as measured by the MME is positively related to the ability to authentically pronounce a second language. Essentially the MME measure coupled with the Verbal Mental Reasoning test of intelligence and a simple but apparently effective measure of motivation provide, we believe, a major contribution to the prediction of pronunciation ability. Adding the Army Language Aptitude Test as a linguistic measure, the combined instruments constitute a powerful predictive battery.
Reduced selective constraint in endosymbionts: elevation in radical amino acid replacements occurs genome-wide.

As predicted by the nearly neutral model of evolution, numerous studies have shown that reduced Ne accelerates the accumulation of slightly deleterious changes under genetic drift. While such studies have mostly focused on eukaryotes, bacteria also offer excellent models to explore the effects of Ne. Most notably, the genomes of host-dependent bacteria with small Ne show signatures of genetic drift, including elevated Ka/Ks. Here, I explore the utility of an alternative measure of selective constraint: the per-site rate of radical and conservative amino acid substitutions (Dr/Dc). I test the hypothesis that purifying selection against radical amino acid changes is less effective in two insect endosymbiont groups (Blochmannia of ants and Buchnera of aphids), compared to related gamma-Proteobacteria. Genome comparisons demonstrate a significant elevation in Dr/Dc in endosymbionts that affects the majority (66–79%) of shared orthologs examined. The elevation of Dr/Dc in endosymbionts affects all functional categories examined. Simulations indicate that Dr/Dc estimates are sensitive to codon frequencies and mutational parameters; however, estimation biases occur in the opposite direction as the patterns observed in genome comparisons, thereby making the inference of elevated Dr/Dc more conservative. Increased Dr/Dc and other signatures of genome degradation in endosymbionts are consistent with strong effects of genetic drift in their small populations, as well as linkage to selected sites in these asexual bacteria. While relaxed selection against radical substitutions may contribute, genome-wide processes such as genetic drift and linkage best explain the pervasive elevation in Dr/Dc across diverse functional categories that include basic cellular processes. Although the current study focuses on a few bacterial lineages, it suggests Dr/Dc is a useful gauge of selective constraint and may provide a valuable alternative to Ka/Ks when high sequence divergences preclude estimates of Ks. Broader application of Dr/Dc will benefit from approaches less prone to estimation biases.
The June 1965 magnetic storm: Millstone Hill observations☆

Abstract Incoherent (Thomson) scatter observations are presented for the F -region electron density over the altitude range 150–650 km during the first 48 hr of a large magnetic storm that occurred in June 1965. These measurements, made at Millstone Hill (42.6°N, 71.5°W), are compared with measurements of the peak electron density N m F 2 and total ionospheric electron content n t reported for a number of other stations during the same storm. It is shown that anomalously large values of N m F 2 and n t were widely observed during the late afternoon on June 15 and 16, and that these arose because the layer was driven to a much larger height than normal. This motion coincided with the development of a large local increase in the total magnetic field. We suggest that an east-west electric field associated with the asymmetric part ( DS ) of the ring current system was responsible for the vertical motion of the layer and hence for the large increases of n t and N m F 2 seen in some storms a little before sunset.
Synchronous effects of temperature, hydrostatic pressure, and salinity on growth, phospholipid profiles, and protein patterns of four Halomonas species isolated from deep-sea hydrothermal-vent and sea surface environments.

Four strains of euryhaline bacteria belonging to the genus Halomonas were tested for their response to a range of temperatures (2, 13, and 30°C), hydrostatic pressures (0.1, 7.5, 15, 25, 35, 45, and 55 MPa), and salinities (4, 11, and 17% total salts). The isolates were psychrotolerant, halophilic to moderately halophilic, and piezotolerant, growing fastest at 30°C, 0.1 MPa, and 4% total salts. Little or no growth occurred at the highest hydrostatic pressures tested, an effect that was more pronounced with decreasing temperatures. Growth curves suggested that the Halomonas strains tested would grow well in cool to warm hydrothermal-vent and associated subseafloor habitats, but poorly or not at all under cold deep-sea conditions. The intermediate salinity tested enhanced growth under certain high-hydrostatic-pressure and low-temperature conditions, highlighting a synergistic effect on growth for these combined stresses. Phospholipid profiles obtained at 30°C indicated that hydrostatic pressure exerted the dominant control on the degree of lipid saturation, although elevated salinity slightly mitigated the increased degree of lipid unsaturation caused by increased hydrostatic pressure. Profiles of cytosolic and membrane proteins of Halomonas axialensis and H. hydrothermalis performed at 30°C under various salinities and hydrostatic pressure conditions indicated several hydrostatic pressure and salinity effects, including proteins whose expression was induced by either an elevated salinity or hydrostatic pressure, but not by a combination of the two. The interplay between salinity and hydrostatic pressure on microbial growth and physiology suggests that adaptations to hydrostatic pressure and possibly other stresses may partially explain the euryhaline phenotype of members of the genus Halomonas living in deep-sea environments.
Theory of Tunneling and its Dependence on a Longitudinal Magnetic Field

A theory of interband tunneling due to a constant electric field is presented which is free of certain objections to previous theories. It is shown that the expression for the Zener current has new terms oscillatory in the electric field, which reflect the Stark quantization of the longitudinal motion of the electron. It is pointed out that for sufficiently small electric fields, the tunneling probability itself is an oscillatory function of the electric field. The effect of a longitudinal magnetic field on the tunneling is calculated for a class of substances. The tunneling in InSb in a magnetic field is considered in detail. Effects of spin-orbit interaction and nonparabolicity of energy bands are taken into account.