cssi/SciSciGPT-SciSciNet huggingface dataset:
Modeling the three-dimensional structure of RNA using discrete nucleotide conformational sets.

Abstract The flexibility about seven torsion angles in nucleotides constitutes a severe obstacle to computer modeling of RNA. The computational feasibility of RNA conformational searches can be enhanced by assigning to each nucleotide a set of discrete conformations. In this work, four types of discrete conformational sets for the atomic representation of nucleotide structures were defined and evaluated. These sets, comprising between 10 and 30 conformations, were tested for their ability to reproduce known RNA structures and to generate structures responding to new specifications. Conformational searches were performed with the MC-SYM program, which allows for the generation of all structures satisfying a predetermined set of three-dimensional constraints in a given discrete space. Results with known hairpin loop structures show that root-mean-square deviations of about 1·5 A for backbone atoms and about 2?0 A for all atoms between the modeled and X-ray crystal structures can be expected. The conformational set that gives the most faithful representation of test structures is based on the classification of nucleotide conformations derived from a structural database. Representative conformations are selected from each class that adequately sample variations in backbone direction, sugar pucker and base orientation. With this conformational set, most of the important features of test hairpin structures are reproduced with fidelity, indicating that biologically useful models can be constructed from the combination of discrete nucleotide conformations and an algorithm that rapidly and systematically scans the pre-defined conformational space.
Modified lignin in tobacco and poplar plants over‐expressing the Arabidopsis gene encoding ferulate 5‐hydroxylase

Ferulate 5-hydroxylase (F5H) is a cytochrome P450-dependent monooxygenase that catalyses the hydroxylation of ferulic acid, coniferaldehyde and coniferyl alcohol in the pathways leading to sinapic acid and syringyl lignin biosynthesis. Earlier studies in Arabidopsis have demonstrated that F5H over-expression increases lignin syringyl monomer content and abolishes the tissue-specificity of its deposition. To determine whether this enzyme has a similar regulatory role in plants that undergo secondary growth, we over-expressed the F5H gene in tobacco and poplar. In tobacco, over-expression of F5H under the control of the cauliflower mosaic virus 35S promoter increased lignin syringyl monomer content in petioles, but had no detectable effect on lignification in stems. By contrast, when the cinnamate 4-hydroxylase (C4H) promoter was used to drive F5H expression, there was a significant increase in stem lignin syringyl monomer content. Yields of thioglycolic acid and Klason lignin in C4H-F5H lines were lower than in the wild-type, suggesting that F5H over-expression leads to a reduced deposition or an altered extractability of lignin in the transgenic plants. Histochemical analysis suggested that the novel lignin in C4H-F5H transgenic lines was altered in its content of hydroxycinnamyl aldehydes. Transgenic poplar trees carrying the C4H-F5H transgene also displayed enhanced lignin syringyl monomer content. Taken together, these data show that hydroxylation of guaiacyl-substituted lignin precursors controls lignin monomer composition in woody plants, and that F5H over-expression is a viable metabolic engineering strategy for modifying lignin biosynthesis in forest species.
Characterization and reactivity of broiler chicken sera to selected recombinant Campylobacter jejuni chemotactic proteins

Campylobacter jejuni, a Gram-negative rod bacterium, is the leading causative agent of human acute bacterial gastroenteritis worldwide. Consumption and handling of raw or undercooked poultry are regarded as a major source for human infection. Because bacterial chemotaxis guides microorganisms to colonization and invasion in the host cells, proteins involved in chemotactic processes can be novel targets for vaccine development. In this communication, we report amplification, cloning and expression of the C. jejuni chemotactic proteins in an Escherichia coli expression system. A total of 15 chemotactic protein genes were successfully expressed. These recombinant proteins were confirmed by nucleotide sequencing, SDS-PAGE analysis and immunoblot analysis of six-His and hemagglutinin tags. Twelve recombinant chemotactic proteins were further tested whether they were antigenic using sera from broiler chickens older than 4 weeks. The immunoblot results show that each chicken serum reacted to a variety of the recombinant proteins, but all sera reacted to the Cjj0473 gene product (annotated as a methyl-accepting chemotaxis protein), suggesting that anti-Campylobacter antibodies may be prevalent in the poultry population. These antibody screening results provide a rationale for further evaluation of the Cjj0473 protein as a potential vaccine for broilers to improve human food safety.
Comparison of four different silver-staining techniques for salivary protein detection in alkaline polyacrylamide gels

Abstract Four different silver-staining methods for detecting proteins in alkaline polyacrylamide gels were compared following the electrophoresis of parotid saliva. Differences in staining selectivity and sensitivity of specific acidic proteins were found among the silver-staining systems. The unique structure of salivary acidic proline-rich proteins may contribute to the lack of silverstaining sensitivity found among this particular group.
Effects of the oophagous bivalve Acesta oophaga on the morphology and fecundity of its deep‐sea tubeworm host, Lamellibrachia luymesi

The deep-sea bivalve Acesta oophaga lives attached to the anterior end of the vestimentiferan tubeworm, Lamellibrachia luymesi, at cold methane seeps. The bivalve is found almost exclusively on female tubeworms, where it consumes the lipid-rich eggs of L. luymesi that are spawned year round (Biological Bulletin, 209, 2005, 87). It is apparent that A. oophaga benefits directly from this close association, but the consequences for the tubeworm host may be more complicated than just a simple predator–prey interaction. Since A. oophaga completely surrounds the tube opening and plume of the worm, it is likely that its presence would limit oxygen uptake by L. luymesi, thereby inhibiting worm growth and reproduction. We hypothesized that occupied tubeworms would compensate for this by growing larger plumes for oxygen uptake. To explore the effects of bivalve presence/absence on female tubeworms, several morphological features, including body size, plume length, tube diameter, and tube segment length, as well as instantaneous fecundity, were compared. Results suggest that the mere presence of A. oophaga has a significant impact on the morphology of its host worm, as all measures of worm size, except for tube segment length, were significantly greater with clams present. Additionally, instantaneous fecundity was 3.5 times higher in occupied worms, implying that tubeworms are not oxygen-deprived or energy limited as a result of bivalve presence. Our findings suggest that the association between these two deep-sea organisms may be a more complex form of symbiosis than the simple predator–prey relationship, as previously thought.
Association of Ionized Polymer Micelles with Oppositely Charged Polyelectrolytes

We consider the equilibrium structure of the complex formed by an ionized starlike polymer micelle with oppositely charged polyion. The charges on both the micelle and polyion are quenched, and the complex is immersed in a salt-free aqueous solution. Analytical and numerical self-consistent-field (SCF) models are employed to describe the properties of such a complex. Our findings indicate that the micelle−polyion complex is essentially electroneutral as a whole and that the polyion replaces almost all small counterions within the micelle corona. The structure of the complex is governed by the effective second and third virial coefficients of monomer−monomer interactions and is much more compact than original ionized micelle. Furthermore, the structure of the complex is predicted to be insensitive to the molecular weight of the polyion. The effective virial coefficients can be mediated by variations in the solvent quality, the degree of ionization, and the incompatibility of the branches of the micelle and...
Occupational blood-borne diseases in surgery.

Abstract Background Human immunodeficiency virus (HIV), hepatitis B (HBV), and hepatitis C (HCV) infections are transmitted by blood exposure. Surgeons have been concerned about the risks of blood exposure in the operating room as a potential source of occupational infections from these viruses. The actual risk and frequency of operating room transmission remains poorly understood by many surgeons. Methods The pertinent recent literature on the pathophysiology, diagnosis, prevention, and treatment of HIV, HBV and HCV were reviewed to address the current understanding of these viruses as occupational risks to surgeons. Results HIV transmission to surgeons has not been documented in the United States by the Centers for Disease Control. HIV transmission from a surgeon to a patient in the environment of the operating room, as well as transmission from an HIV-infected surgeon to a patient, has not been documented. HBV infection of surgeons has declined with the general acceptance of the HBV vaccine. HCV infection remains a real risk for transmission in the operating room, given that no vaccine is currently available and that the overall number of chronically infected patients remains quite high. Conclusion The risk of occupational infection from known viral pathogens for surgeons is low, but it is not zero. Effective barriors, modified patterns of behavior, and prompt responses to blood exposure events are the best methods for prevention.
The Cosmic γ -Ray Spectrum near 1 MeV Observed by the ERS-18 Satellite

In this paper, we wish to report new data obtained on the total, or omnidirectional, cosmic γ-ray flux in the 250 keV to 6 MeV range. Flux in this energy range up to 2 MeV was first detected on the Ranger 3 (Metzger et al., 1964) and has been confirmed up to 0.5 MeV and extended to lower energies by a series of rocket (Gorenstein et al., 1969; Seward et al., 1967) and balloon measurements (Bleeker et al., 1966; Rocchia et al., 1967). Observation of the spectrum at higher energies has become of considerable importance since the recent successful detection of galactic 100 MeV γ-rays by the OSO-3 (Clark et al., 1968).
In vitro hemodynamic model of the arm arteriovenous circulation to study hemodynamics of native arteriovenous fistula and the distal revascularization and interval ligation procedure

Background Experimental modeling of arteriovenous hemodialysis fistula (AVF) hemodynamics is challenging. Mathematical modeling struggles to accurately represent the capillary bed and venous circulation. In vivo animal models are expensive and labor intensive. We hypothesized that an in vitro, physiologic model of the extremity arteriovenous circulation with provisions for AVF and distal revascularization and interval ligation (DRIL) configurations could be created as a platform for hemodynamic modeling and testing. Methods An anatomic, upper extremity arteriovenous model was constructed of tubing focusing on the circulation from the subclavian artery to subclavian vein. Tubing material, length, diameter, and wall thickness were selected to match vessel compliance and morphology. All branch points were constructed at physiologic angles. The venous system and capillary bed were modeled using tubing and one-way valves and compliance chambers. A glycerin/water solution was created to match blood viscosity. The system was connected to a heart simulator. Pressure waveforms and flows were recorded at multiple sites along the model for the native circulation, brachiocephalic AVF configuration, and the AVF with DR without and with IL (DR no IL and DRIL). Results A preset mean cardiac output of 4.2 L/min from the heart simulator yielded a subclavian artery pressure of 125/55 mm Hg and a brachial artery pressure of 121/54 mm Hg with physiologic arterial waveforms. Mean capillary bed perfusion pressure was 41 mm Hg, and mean venous pressure in the distal brachial vein was 17 mm Hg with physiologic waveforms. AVF configuration resulted in a 15% decrease in distal pressure and a 65% decrease in distal flow to the hand. DR no IL had no change in distal pressure with a 27% increase in distal flow. DRIL resulted in a 3% increase in distal pressure and a 15% increase in distal flow to the hand above that of DR no IL. Flow through the DR bypass decreased from 329 mL/min to 55 mL/min with the addition of IL. Flow through the AVF for both DR no IL and DRIL was preserved. Conclusions Through the construction and validation of an in vitro, pulsatile arteriovenous model, the intricate hemodynamics of AVF and treatments for ischemic steal can be studied. DR with or without IL improved distal blood flow in addition to preserving AVF flow. IL decreased the blood flow through the DR bypass itself. The findings of the AVF as a pressure sink and the relative role of IL with DR bypass has allowed this model to provide hemodynamic insight difficult or impossible to obtain in animal or human models. Further study of these phenomena with this model should allow for more effective AVF placement and maturation while personalizing treatment for associated ischemic steal.
Testosterone and human aggressiveness: an analysis

Abstract Recent evidence of a positive correlation between testosterone and human aggressiveness is in contradiction with general principles of the evolution of mammalian behavior. Analysis of the primate literature, both human and non-human, reveals the presence of a powerful extraneous variable, stress, in studies reporting a positive correlation. Stress is known to influence both testosterone and aggressiveness. Under conditions of stress, circulating testosterone and aggressiveness may be measurably correlated, even though these variables are not causally linked.
Investigation of the interaction potential between a neutral molecule and a conducting surface

The interaction potential between a neutral molecule and a conducting surface is investigated through the study of the deflection of a beam of molecules by the conducting surface. The ultrahigh-vacuum system gave a vacuum below 5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}11}$ Torr, where the scattering by the residual gas is negligible in the deflection region of interest. An ${r}^{\ensuremath{-}3}$ potential is predicted from a model in which the permanent dipole of the molecule interacts with its image in the surface of an ideal conductor. The measured deflection by the conducting surface does not agree precisely in form with this predicted potential. When this small difference in form is ignored, the observed interaction constants indicate that the model does, in fact, account for the major part of the interaction. These observed constants are from 0.42 to 0.68 of the predicted values. There remain unevaluated corrections arising from the finite resistivity of the conductor, and from a contribution by the fluctuation of the instantaneous dipole moment of the molecule from its statistical average (i.e., the permanent dipole moment).
SPECTROSCOPIC STUDIES OF CUTANEOUS PHOTOSENSITIZING AGENTS-XIII. pH DEPENDENCE OF THE PHOTOCHEMISTRY OF PHOTO ALLERGENS BITHIONOL AND FENTICHLOR: AN ELECTRON spIN RESONANCE STUDY OF THE FREE RADICAL PHOTOPRODUCTS

The photoallergens bithionol (BT) and fentichlor (FT) generated free radical photoproducts upon UV photolysis which were observable by direct electron spin resonance (ESR). Both the yield and the type of free radical photoproducts were affected by pH, and to some extent, concentration of oxygen and concentrations of the photosensitizers. At pH 8.5, bithionol (0.9 mM) generated a semiquinone type free radical (BI) via a mechanism which probably involves substitution of the 4-chlorine by hydroxyl to form the corresponding hydroquinone followed by oxidation. The photolysis of 4-chlorophenol, 4-chlorocatechol and 2,2'-methylene-bis(4-chlorophenol) also generated the corresponding semiquinone radicals, suggesting that this mechanism is shared by other 4-chlorophenols. At pH 8.5, only photoproduct BI was observed during the irradiation of BT; FT related photoproducts were not observed at this pH. However, at higher pH values (pH 10.7 or pH 12), FT photoproducts were also observed in addition to BI upon prolonged irradiation. Moreover, the yield of BI increased drastically at higher pH. Oxygen did not play any role at pH 10.7, although it enhanced the yield of BI at pH 8.5. At pH 8.5, irradiated fentichlor generated, in roughly equal amounts, a semiquinone radical (Fla) and an unidentified species which contained two inequivalent protons (FII). At higher pH values (pH 10.7 and pH 12), at least four species were observed. All of the species are believed to be semiquinone radicals and two have been unambiguously identified. The yield of FI increased by a factor of 50 as the pH was increased from 8.5 to 12. Oxygen played only a minor role at pH 10.7 and above. However, at pH 8.5, it also enhanced the yield of FI.
Intuitive statistical inferences about diffuse hypotheses

Abstract When data are sampled from a population and subjects revise probability estimates about which population is being sampled, their revisions are less than the optimal amount calculated by using Bayes's theorem; they are conservative. The experiments reported here used binomial populations with proportions that were either defined precisely by a display or defined diffusely by a sample of data. The experimenter randomly selected one of two populations and then sampled data from the selected population. The subjects made very nearly Bayesian revisions on the basis of the first datum sampled, but became markedly conservative when the task required aggregating evidence across a sequence of data. This result was independent of whether population proportions were defined precisely or diffusely.
Dihydroxy bile acids activate the transcription of cyclooxygenase-2.

Bile acids, endogenous promoters of gastrointestinal cancer, activate protein kinase C (PKC) and the activator protein-1 (AP-1) transcription factor. Because other activators of PKC and AP-1 induce cyclooxygenase-2 (COX-2), we determined the effects of bile acids on the expression of COX-2 in human esophageal adenocarcinoma cells. Treatment with the dihydroxy bile acids chenodeoxycholate and deoxycholate resulted in an ∼10-fold increase in the production of prostaglandin E2(PGE2). Enhanced synthesis of PGE2 was associated with a marked increase in the levels of COX-2 mRNA and protein, with maximal effects at 8–12 and 12–24 h, respectively. In contrast, neither cholic acid nor conjugated bile acids affected the levels of COX-2 or the synthesis of PGE2. Nuclear run-off assays and transient transfections with a human COX-2promoter construct showed that induction of COX-2 mRNA by chenodeoxycholate and deoxycholate was due to increased transcription. Bile acid-mediated induction of COX-2 was blocked by inhibitors of PKC activity, including calphostin C and staurosporine. Treatment with bile acid enhanced the phosphorylation of c-Jun and increased binding of AP-1 to DNA. These data are important because dihydroxy bile acid-mediated induction of COX-2 may explain, at least in part, the tumor-promoting effects of bile acids.
Market Liquidity and Trader Welfare in Multiple Dealer Markets: Evidence from Dual Trading Restrictions

In the context of dual trading restrictions, we examine whether aggregate liquidity measures are appropriate indicators of trader welfare in multiple dealer markets. Consistent with our theoretical results, we show empirically that dual trading restrictions did not affect market liquidity significantly, but dual traders of above-average skills may have quit brokerage and switched to trading exclusively for their own accounts following restrictions. Further, customers of these dual-traders had lower trading costs in the period before restrictions relative to the trading costs of all customers after restrictions.
Effect of gravity modulation on the stability of convection in a vertical slot

The nature of instability occurring in a differentially heated infinite slot under steady gravity depends only on the Prandtl number of the contained Boussinesq fluid. For fluids with Pr 12.5, the instability is buoyancy dominated and onsets in an oscillatory mode. In this paper, we examine the effect of gravity modulation on the stability characteristics of convection in an infinite slot with both kinds of fluids, in particular, Pr = 1 and Pr = 25. Using the method of Sinha & Wu (1991), we are able to obtain accurate results without excessive numerical integration in the linear stability analysis by Floquet theory. Results show that, for Pr = 1, at a non-dimensional oscillation frequency ω = 20, the critical state alternates between the synchronous and subharmonic modes. At higher frequencies, ω > 100, all critical states occur in the synchronous mode. For Pr = 25, with a modulation amplitude ratio of 0.5, resonant interaction occurs in the neighbourhood of ω = 2σc, where σc is the oscillation frequency of the instability at the critical state under steady gravity. This resonant interaction is destabilizing, with the critical Grashof number being reduced by approximately 20% from that at steady gravity. It is due to the presence of a detached subharmonic branch of the marginal stability curve. In frequency ranges where the detached subharmonic branch is absent, the critical state is in the quasi-periodic mode consisting of two waves of different oscillation frequencies whose sum is the forcing frequency. An analysis of the rate of change of the perturbation kinetic energy shows that, for Pr = 1, the instability is shear dominated regardless of the mode of oscillation, synchronous or subharmonic. Similarly, for Pr = 25, the instability is buoyancy dominated whether it is in the quasi-periodic or subharmonic mode. The mode switching is a response to the forcing and is independent of the dominant mechanisms of instability.
Low-pressure flame composition and the origin of C3H3+

Low-pressure flat premixed flames of C 2 H 4 /O 2 , C 2 H 2 /O 2 , and H 2 /O 2 with small amounts of added C 2 H 4 and C 2 H 2 have been investigated by means of microprobe sampling, flame ion mass epectrometry, and optical spectrometry in an attempt to elucidate the formation mechanism of C 3 H 3 + and the role of electronically excited CH in chemi-ionization. Ion profiles have been taken for C 3 H 3 + and other flamefront ions in order to determine their relative concentrations and decay mechanism. The kinetic dependences of the various observed species on added C 2 H 2 or C 2 H 4 have been examined and the results employed to test previously proposed mechanisms for the formation of C 3 H 3 + and the importance of CH * in the over-all chemionization process. Neither the B 2 Σ − nor the A 2 Δ state of CH commonly observed in emission from hydrocarbon combustion flames has been found to contribute significantly to chemi-ionization through either CH * +C 2 H 2 →C 3 H 3 + + e (1) CH * +O→CHO + + e .(2) This conclusion has been tested in several flames over a range of equivalence ratios commonly employed in combustion research and verified under conditions of widely varying composition and ion concentration. Despite the variations in flow rate and hydrocarbon composition in flames at 2 and 4 Torr, it has been found that all secodary ions which are formed and destroyed in or near the flame front decay with the same rate constant. The results have been interpreted as being indicative that all these ions react with the same oxidative species in a set of reactions having the same bimolecular rate coefficient, k r =(4±2)×10 −11 cm 3 sec −1 . It has also been shown that Reaction (1) is not responsible for C 3 H 3 + formation and that this ion probably arises instead from proton transfer and/or ion molecule (CH + transfer) reactions involving C 3 H 2 or C 2 H 2 . However, the addition of C 2 H 2 to a H 2 /O 2 flame produces C 3 H 3 + through a different mechanism than that which is operative for C 2 H 4 addition. The mechanisms are similar in that the same neutral species is probably involved, but the charged species involved differ markedly as the result of distinctly different spectra of ion-molecule kinetic relationships.
Schizophrenia should be renamed to help educate patients and the public.

Background: A new name for schizophrenia, reflecting a biopsychosocial conceptualization, may have utility in educating patients and the public. If readily translatable, it would be of great value in transcultural psychiatry. It may be clinically beneficial to psychoeducation in evidence-based treatment modalities such as medication management, multifamily group psycho-education and cognitive therapy.Discussion: Neuro-Emotional Integration Disorder (NEID) is proposed as the biopsychosocial candidate term to replace schizophrenia. The following subtypes are proposed: defensive type replacing paranoid, motoric type replacing catatonic, Brief Neuro-Emotional-Integration Breakdown (B-NEIB) replacing brief psychotic episode, NEID-Time Limited replacing schizophreniform disorder. Schizoaffective disorder might be termed NEID-Bipolar type. Anti-psychotic medication would be termed NEI-Enhancing medication.Conclusions: By emphasizing the neuropsychiatric basis of this ‘highly treatable brain disorder’ through its...
Tandemly repeated sequences are present at the ends of the DNA of raccoonpox virus

Abstract The DNA of raccoonpox virus (RCN) has been characterized by restriction enzyme analysis. DNA hybridization studies showed that all Hin dIII fragments of the 215-kbp RCN DNA share some nucleotide sequence similarity with fragments of the DNA of cowpox virus (CPV). This information was used to construct a Hin dIII restriction map of the RCN DNA. The nucleotide sequence of the 2.2-kbp Sa /1 end fragment of the RCN DNA has been determined from a cloned copy of the Hin dIII O fragment. Of this 2.2-kbp region 75% consists of short, tandemly repeated sequences. It does not contain any open reading frames capable of encoding polypeptide chains of more than 62 amino acids. There are six related types of repeated sequence, and these are arranged into two separate sets, each flanked by nonrepeated sequences. The nucleotide sequences of both repeated and nonrepeated sequences within this Sa /1 fragment are extremely similar to those of the Sa /1-generated end fragments of the DNAs of CPV and vaccinia virus. The arrangements of the repeated and nonrepeated sequences are also similar in the DNAs of these three viruses. In contrast, the remainder of the RCN DNA is markedly different from the DNAs of other orthopoxviruses. The high degree of similarity between the ends of the RCN DNA and the ends of the other orthopoxvirus DNAs suggests that the complex arrays of repeated and nonrepeated sequences have been conserved because they have a role in virus multiplication.
Extreme temperature 6H-SiC JFET integrated circuit technology

Extreme temperature semiconductor integrated circuits (ICs) are being developed for use in the hot sections of aircraft engines and other harsh-environment applications well above the 300 °C effective limit of silicon-on-insulator IC technology. This paper reviews progress by the NASA Glenn Research Center and Case Western Reserve University (CWRU) in the development of extreme temperature (up to 500 °C) integrated circuit technology based on epitaxial 6H-SiC junction field effect transistors (JFETs). Simple analog amplifier and digital logic gate ICs fabricated and packaged by NASA have now demonstrated thousands of hours of continuous 500 °C operation in oxidizing air atmosphere with minimal changes in relevant electrical parameters. Design, modeling, and characterization of transistors and circuits at temperatures from 24 °C to 500 °C are also described. CWRU designs for improved extreme temperature SiC JFET differential amplifier circuits are demonstrated. Areas for further technology maturation, needed prior to beneficial system insertion, are discussed. Optical micrograph of a 500 °C durable 6H-SiC JFET differential amplifier IC chip fabricated at NASA prior to packaging. Digitized waveforms measured during the 1st (solid black) and 6519th (dashed grey) hour of 500 °C operational testing show no change in output characteristics.
Skill Level and Audience Effects on Performance of a Karate Drill

Abstract Skilled (12 male, 4 female) and unskilled (13 male, 4 female) American karate students kicked a target as many times as possible for four 15-s trials. They performed this multiple standing roundhouse kick drill both in the presence of an evaluative audience of karate experts and without the audience present. The presence of an audience had no effect on accurate kicks or errors for skilled subjects but did reduce the frequency of accurate kicks for unskilled performers. Several measures of socially influenced motivation failed to discriminate performers who would be more or less sensitive to the audience. Results are interpreted as consistent with social facilitation predictions and indicated that unskilled subjects sacrificed desired performance in order to avoid an increase in errors.
Langmuir probe and mass spectrometric measurements in inductively coupled CF4 plasmas

Electron and ion energy distribution functions and other plasma parameters such as plasma potential (Vp), electron temperature (Te) and electron and ion number densities (ne and ni) in low-pressure CF4 plasmas have been measured. The experiments were conducted in a GEC cell using an inductively coupled plasma device powered by a 13.56 MHz radiofrequency (rf) power source. The measurements were made at 300 W of input rf power at 10, 30 and 50 mTorr gas pressures. Langmuir probe measurements suggest that ne, ni and Vp remain constant over 60% of the central electrode area, beyond which they decrease. Within the limits of experimental error (±0.25 eV), Te remains nearly constant over the electrode area and peaks towards the electrode edge before falling rapidly. Te and Vp increase with a decrease in pressure. ne and ni are not affected as significantly as Te or Vp by variation in the gas pressure. The electron energy distribution function measurements indicate a highly non-Maxwellian plasma. CF3+ is the most dominant ion product of the plasma, followed by CF2+ and CF+. Significant amounts of etch products, SiFx/COFx(x = 0-3), of the quartz window were also detected. The concentrations of CF2+ and CF+ are much larger than that is possible from direct electron impact ionization of the parent gas. The cross-section data suggest that the direct electron impact ionization of fragment neutrals and negative ion production by electron attachment may be responsible for increase of the minor ions.
Ferroelectricity and structure in the YMnO3 family

The 1963 discovery of ferroelectricity in YMnO3 was accompanied by an experimental Curie temperature (Tc) reported as 913 K; this value was revised to 1270 K in the following decade. Subsequently, YInO3 was shown to be isostructural with YMnO3 and later demonstrated to satisfy the structural criteria for ferroelectricity; recent unpublished measurements give Tc (YInO3) = 835 (15) K. The experimental Tc value of 913 K for YMnO3 is in satisfactory agreement with the calculated 1220 (100) K value as derived from a very recent structural refinement, the experimental Tc of 835 (15) K for YInO3 with the calculated 760 (120) K. The full YMnO3 family includes the AMnO3 subfamily with A = Y, Ho, Er, Tm, Yb, Lu, Sc, In; the AInO3 subfamily with A = Y, Gd, Dy, Ho, Tb; and the AGaO3 subfamily with A = Y, Ho, Er. The Tc values of six family members with known structure, in addition to YMnO3 and YInO3, have been structurally derived as 1310 (110) K for ErMnO3, 1290 (165) K for LuMnO3, 1270 (110) K for YbMnO3, 1220 (105) K for ScMnO3, 540 (375) K for InMnO3 and 1020 (100) K for YGaO3. The agreement between predicted and experimental Tc values for ErMnO3, LuMnO3 and YbMnO3, in addition to that for YMnO3 and YInO3, leads to the confident prediction that ScMnO3, InMnO3 and YGaO3 are new ferroelectrics. The remaining six members of the full YMnO3 family are also expected to be new ferroelectrics.
Can the QGP Be Found Using Only an Electromagnetic Calorimeter

Measurements using the finely segmented EM Calorimeter in PHENIX are presented. The issue of whether these are sufficient to claim discovery of the Quark–Gluon Plasma is discussed.
Perspectival Understanding of Conceptions and Conceptual Growth in Interaction

Abstract We propose a bridge between cognitive and sociocultural approaches that is anchored on the sociocultural side by distributed cognition and participation, and on the cognitive side by information structures. We interpret information structures as the contents of distributed knowing and interaction in activity systems. Conceptual understanding is considered as achievement of discourse in activity systems, and conceptual growth is change in discourse practice that supports more effective conceptual understanding. We also introduce a concept of perspectival understanding, in which accounts of cognition, including conceptual understanding, include points of view. This concept generalizes the concept of schema by hypothesizing that a perspectival understanding can be constructed by constraint satisfaction when a sufficient schema is not known or recognized. We provide an example in which perspectival understanding was jointly constructed, illustrating an interactional process we call “constructive list...
Quantum size effects in amorphous Si superlattice solar cells

Abstract Amorphous silicon/alloy superlattices provide advantages in solar cell design, such as (a) effective band gap widening (b) effective mass separation (c) increased open-circuit voltage. The latter increases via Fermi level control, due to p-doping of potential barriers, pushing EF towards the valence bands, with simultaneous widening of the effective band gap, thus leading to potentially higher collection incident wavelengths. The density of gap states in the heavily doped layer is modeled as an exponential whose parameter kT* can be varied by the doping concentrations, while its activation energy saturates at some value. This communication provides (i) a general formulation of the problem at finite temperatures as well as numerical results for specific realizable contacts (ii) detailed treatment of gap states (iii) the neutrality condition (iv) a relation between Fermi level position and open-circuit voltage in the nitride region (superlattice p-region). For a p-(a-SiN: H/a-Si: H)-i (a-Si: H)-n (a-Si: H) sample, we compute the Fermi level position relative to the a-Si: H valence band edge. For low and wide gap thin layers of the order of 2.5–3.5 nm, open-circuit voltage values are predicted in excess of 1.05 V, and efficiencies are predicted in excess of 12%.
Dissolution of deep-sea carbonate: preliminary calibration of preservational and morphologic aspects

Dissolution experiments, using planktonic foraminifera from a well-preserved tropical sediment, suggest that for this assemblage the lysocline corresponds to the level of about 80% foraminiferal weight loss by dissolution. The R0 level (the greatest depth at which there is no relative increase in the resistant species due to dissolution) corresponds to the level of about 50% foraminiferal weight loss. This indicates that significant dissolution occurs at depths shallower than the one at which the first assemblage changes are evident. The dissolution experiments show about a one-order-of-magnitude range in the resistances of the planktonic foraminifera. The uniformity of resistance within species populations shows large variation. In the Globigerinoides ruber population, the smaller specimens (< 250 μm) appear more resistant than the larger ones. Calcareous benthonic foraminifera, as a group, are less resistant than the resistant planktonic foraminifera. The tropical nannofossil assemblage may be less resistant to dissolution than the co-existing larger planktonic foraminifera. An equation is derived which uses the morphologic features of the tests of planktonic foraminifera to rank species by their resistance to dissolution. An Assemblage Solution Index (ASI) is calculated to characterize the preservation state of entire assemblages of planktonic foraminifera. The ASI shows excellent resolution of differences in preservation for sediments between the lysocline and calcite compensation depth and is an objective means for comparison of the preservation states of assemblages in which species are not co-occurring.
Impacts of the distribution of households across income groups in a differential demand system for orange juice

This study examines the effects of the distribution of households across income groups on the Rotterdam demand model’s income and price responses. The model’s marginal propensities to consume and Slutsky coefficients are specified as varying parameters dependent on the portions of households falling in different income categories. This specification was used to analyze the demand for different orange-juice products across 52 US cities. The results indicate that for these products the distribution of households across income groups is an important determinant of the model coefficients.
Reliability evaluation and optimization of series–parallel systems with k-out-of-n: G subsystems and mixed redundancy types

This article considers the redundancy allocation problem pertaining to k-out-of-n: G heterogeneous series–parallel systems. Different from existing approaches that consider either hot or cold stand...
NEA Presidential Address: Gender Inequality and Human Development in Sub- Saharan Africa

This Presidential Address considers the effects of gender inequality on human development in Sub-Saharan Africa. Parameter estimates from quantile and ordinal categorical latent variable specifications of the relationship between components of the Human Development Index and measures of gender inequality suggests that human development in Sub-Saharan Africa increases with respect to improvements in several measures of gender inequality. The results suggest that inegalitarian laws, norms, traditions and codes of conduct toward women constrain both human and economic development in Sub-Saharan Africa.
The P2Y12 Antagonists, 2-Methylthioadenosine 5′-Monophosphate Triethylammonium Salt and Cangrelor (ARC69931MX), Can Inhibit Human Platelet Aggregation through a Gi-independent Increase in cAMP Levels

ADP plays an integral role in the process of hemostasis by signaling through two platelet G-protein-coupled receptors, P2Y1 and P2Y12. The recent use of antagonists against these two receptors has contributed a substantial body of data characterizing the ADP signaling pathways in human platelets. Specifically, the results have indicated that although P2Y1 receptors are involved in the initiation of platelet aggregation, P2Y12 receptor activation appears to account for the bulk of the ADP-mediated effects. Based on this consideration, emphasis has been placed on the development of a new class of P2Y12 antagonists (separate from clopidogrel and ticlopidine) as an approach to the treatment of thromboembolic disorders. The present work examined the molecular mechanisms by which two of these widely used adenosine-based P2Y12 antagonists (2-methylthioadenosine 5′-monophosphate triethylammonium salt (2MeSAMP) and ARC69931MX), inhibit human platelet activation. It was found that both of these compounds raise platelet cAMP to levels that substantially inhibit platelet aggregation. Furthermore, the results demonstrated that this elevation of cAMP did not require Gi signaling or functional P2Y12 receptors but was mediated through activation of a separate G protein-coupled pathway, presumably involving Gs. However, additional experiments revealed that neither 2MeSAMP nor ARC69931MX (cangrelor) increased cAMP through activation of A2a, IP, DP, or EP2 receptors, which are known to couple to Gs. Collectively, these findings indicate that 2MeSAMP and ARC69931MX interact with an unidentified platelet G protein-coupled receptor that stimulates cAMP-mediated inhibition of platelet function. This inhibition is in addition to that derived from antagonism of P2Y12 receptors.
Urine Screening for Abused Drugs in New Admissions to a VA Hospital

Summary The urine samples from two groups of Veteran's Administration patients newly admitted to general psychiatry units were screened in 1985 and in 1987–88 for abused drugs. The results were compared Kith urine samples from controls with similar age distributions admitted to an alcohol and drug abuse unit or to medical-surgical units. About 40% of all newly admitted patients were positive for one or more controlled drugs, but there were no significant differences among patient groups in the percentage of urine samples positive for these drugs. Marijuana and benzodiazepines were delected frequently in all patient groups and often in combination, although opiates also were frequently detected in the urine samples from the medical-surgical patients. There was a clear decrease in drug-positive samples with age in all patient groups, much of which could be accounted for by decreased marijuana detection.
Structure and Electrochemistry of Carbon-Metal Fluoride Nanocomposites Fabricated by Solid-State Redox Conversion Reaction

Utilizing a solid-state redox-driven conversion reaction enabled by mechanochemistry, conductive C:FeF 3 nanocomposites were fabricated from insulative CF 1 :FeF 2 precursors. All reactions were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The latter provided insights to the progression of the CF and C phases and the metal fluoride during the course of the reaction. Such nanocomposites resulted in a four order of magnitude increase in electrical conductivity and enabled excellent specific capacity approaching 500 mAh/g vs. Li with good reversibility, although at slow rates. Utilizing the theoretical basis of the technique, other couples were examined to experimentally isolate the oxidative power of CF 1 . In the process, we have also shown that a composite of CF 1 :CrF 2 can be easily converted to C:CrF 3 . The resulting nanocomposite exhibited a specific capacity of 682 mAh/g at an average voltage of approximately 1.9 V. The technique is also a powerful method for the fabrication of single phase metal fluoride solid solutions, as demonstrated with the fabrication of Cr 0 . 5 Fe 0 . 5 F 3 .
Thermodynamic properties of two gaseous halogenated ethers from speed-of-sound measurements: Difluoromethoxy-difluoromethane and 2-difluoromethoxy-1,1,1-trifluoroethane

We present measurements of the speed of sound in gaseous difluoromethoxy-difluoromethane (CHF2-O-CHF2) and 2-difluoromethoxy-1,1,1-trifluoroethane (CF3-CH2-O-CHF2). These measurements were performed in an all-metal apparatus between 255 and 384 K. We have obtained ideal-gas heat capacities and second acoustic virial coefficients from analysis of these measurements. Two methods of correlating the second acoustic virial coefficients, a square well model of the intermolecular interaction and a function due to Pitzer and Curl, are presented.
Developmental and immunogenetic features of biologic aging.

The major advances in the prevention of chronic disease are discussed to demonstrate that biologic aging is a normal result of developmental biology and not a disease. Genes that regulate immune processes appear to be significantly related to the rates of biologic aging.
The Teaching of Science: Content, Coherence, and Congruence

stitute, my colleagues, and especially my friend for more than 30 years, John Padalino, thank you for this opportunity to present the Paul F-Brandwein lecture. I take it as a great honor to present a lecture in memory of Paul F-Brandwein a great scientist, a great environmentalist, and a great science teacher. On several occasions, I had the opportunity to talk with Paul F-Brandwein and always found him to be personable and understanding of a young professional who wanted to understand his views on science edu-
Finding relevant PDF medical journal articles by the content of their figures

Literature review is a time-consuming burden because it is hard to find relevant articles. But literature review is so important because it allows researchers to find solutions to their questions/problems from previous work already performed and published by others. It is difficult to wade through documents quickly and assess their quality by only looking at their title, abstract, or even full-text. The human visual system allows us to quickly glance at images and infer the main subject of an article and decide whether we are interested in reading more. In some cases, such as biology articles for example, figures showing photos of experimental results quickly allow a researcher in the literature review phase to determine the quality of the work by its results. This work describes a system for literature review that uses content-based image retrieval (CBIR) techniques to search for relevant documents using the content of figures in a document along with relevance feedback refinement instead of keyword search guesswork. The long-term goal is to use it as a subsystem in a content-based document retrieval system where the figures and their captions are combined with the document's body text. This paper describes the processing of the documents to extract available raster graphics as well as text with its layout and formatting information intact. The process of matching a figure to its caption using this layout information is then described. While caption-based search is implemented but not quite merged into the system yet, the figure-caption matching is complete. Two novel modified tf-idf measures that are being considered to take into account bold/italic text, font size, and document structure as a way to infer text importance rather than just rely on text frequency is detailed mathematically and explained intuitively. CBIR queries where there are multiple images that form the query are issued as separate queries and their results are then merged together.
Designing nanostructured membranes for oxidative dehydrogenation of alkanes using kinetic modeling

Continuum-level modeling and Knudsen dynamics simulations were used to investigate the oxidative dehydrogenation of ethane in nanostructured membranes. Different operational modes were investigated, including pass-through and sweep-gas modes, and pores with total and partial catalyst coverage on the walls were studied. It was determined that by adjusting the aspect ratio (L/d) of the pore in the pass-through mode it is possible to achieve high conversions and yields even for slow reactions. On the other hand, in the sweep-gas mode, the velocity of the reaction limits the conversion and yield that can be achieved. It was also found that, under Knudsen diffusion, covering the wall of the pores only partially with catalyst could improve the per gram conversion obtained. However, it does not improve the selectivity achieved for a given conversion when compared to that obtained in a pore fully covered in catalyst.
The use and abuse of control groups in program evaluation

The selection of a control or contrast group is of utmost importance when designing methods to evaluate programs.