cssi/SciSciGPT-SciSciNet huggingface dataset:
Metal(loid)s and human semen quality: The LIFE Study.

Abstract Multiple studies have demonstrated a global population-wide decline in semen quality, with sperm concentrations having fallen 50 % over the past 50 years. Several metal and metalloid (“metal(loid)”) compounds are known to have testicular toxicity, raising concerns about their contribution to rising infertility. In the male reproductive tract, metal(loid)s can reduce semen quality and disturb function both directly, by inducing tissue damage, and indirectly, by disrupting hormone production and secretion. This study assessed associations between 15 creatinine-adjusted metal(loid)s and 7 measures of semen quality among 413 reproductive-aged men recruited from 16 U.S. counties between 2005–2009. Multi-metal(loid) multivariable linear regression models estimated associations between semen quality endpoints and urinary concentrations of chromium, cobalt, copper, molybdenum, selenium, zinc, antimony, arsenic, barium, cadmium, lead, thallium, tin, tungsten, and uranium. LASSO regression was employed to select model variables and account for multicollinearity of the metal(loid)s. A positive association was observed between tin and sperm morphology (β = 4.92 p = 0.045). Chromium (β = 1.87, p = 0.003) and copper (β= −1.30, p = 0.028) were positively and negatively associated with total sperm count, respectively. With respect to DNA fragmentation, cadmium (β = 12.73, p = 0.036) was positively associated and chromium was negatively associated (β = −5.08, p = 0.001). In this cohort of U.S. population-based men, there was evidence of both positive and negative associations between specific metal(loid)s and semen quality. Additional research is needed to determine interactions between metal(loid)s within a mixture, consistent with typical human exposure, and identify sperm effects resulting from cumulative metal(loid) exposures.
Interlaminar shear fracture healing of thermoset CFRP composite using multiphase thermoplastic healing agents

Abstract The shear fracture toughness (Mode II) recovery of damaged thermoset carbon fiber reinforced polymer (CFRP) composite by multiphase thermoplastic healing agents is presented here. Bio-mimetic heat-activated intrinsic healing was employed to recover the shear fracture toughness of fractured CFRP specimens. The activation of embedded shape memory polymers (SMP) closes the gap between the delaminated faces. Simultaneously, molten thermoplastic polycaprolactone (PCL) healants repair the micro or macro cracks. End notch flexure (ENF) test specimens were fractured in a quasi-static test to verify the proof-of-concept healing under Mode II shear loading. Rapid melting of PCL healants at ∼80 °C enabled the recovery of the damage site, while subsequent solidification recovered the structural integrity. The healing efficiency was quantified by comparing the shear fracture toughness ( G IIc ) of a healed specimen to the similar toughness of a virgin specimen. Maximum 88.39 ± 16.41 % recovery of virgin toughness was observed during the first heal cycles, and the healing efficiency was always greater than 70 % in all subsequent cycles. The fractographic features of the delaminated surfaces were observed and analyzed by scanning electron microscope (SEM) and optical microscope . The fractographic observation elucidated the mechanisms behind the shear toughness recovery in different healing cycles.
The ATS-5 solar cell experiment after 6-1/2 years in synchronous orbit

Several types of solar cell/coverslide combinations were launched into synchronous orbit. The cells were 2 and 10 ohm-cm crucible-grown silicon with thicknesses of 0.2 and 0.3 mm. Coverslides were fused silica, ranging in thickness from 0.15 to 1.52 mm. The cells were mounted on two panels, one a rigid aluminum honeycomb structure, giving essentially infinite backshielding; the other was a thin Kapton-fiberglass substrate, offering minimal protection to the rear surface of the cells. The current-voltage curves of the cells were measured. Correction of cell electrical output to standard temperature and solar intensity was performed, using empirical radiation-dependent corrections. It is found that the cells on the flexible panel degrade much more rapidly than predicted, while the rigid panel cells follow the predictions fairly well. The anomalous behavior of the flexible panel cells is attributed to the deposition of a contaminant on the cell coverslides.
Code Switching and Code Cracking

In exploring ways in which the L1 and code-switching can be used as potential resources in the L2 classroom, Cenoz and Gorter (2011), provide valuable insights for both second language researchers and instructors. First, the various approaches through which code-cracking and interaction have been studied will be mentioned. Next, Cenoz and Gorter’s (2011) Focus on Multilingualism approach will be presented and discussed in relation to code-switching, code-cracking and interaction.
Fine structure of the eyes of an alciopid polychaete, Vanadis tagensis (Annelida)

The fine structure of the pair of large and complex cerebral ocelli of Vanadis tagensis is described. The primary retina with its component photoreceptoral and supportive cells can be divided into four principal layers. Beginning from the basal lamina encapsulating the eye, these are the plexiform, nuclear, pigmented, and receptoral layers. Each photoreceptor consists of an array of densely packed microvilli 6 μm in diameter projecting radially from a cylindrical photoreceptoral process extending about 80 μm into the optic cavity in. the center of the ocellus. A large striated rootlet, 0.5 μm in diameter, and numerous microtubules extend the length of the process. A basal body, without a cilium, has been observed at the tip of the striated rootlet. Long straight microvilli from the supportive cells extend the length of the photoreceptoral processes between the microvilli of adjacent photoreceptors. The shading pigment of the pigmented layer is located in both types of cells. Nuclei of the supportive cells are closer to the pigmented layer and one seventh as numerous as those of the photoreceptoral cells. The supportive cells are irregular in shape and packed with filaments ending in large desmosomes along the proximal border of the pigmented layer. Opposite the primary retina a pigmented iris surrounds the pupil, except on one side where a small group of cells, the secondary retina, is situated. Between the primary and secondary retinas is the apex of a large secretory cell whose cell body lies between the plexiform layer of the primary retina and the basal lamina. The large, spherical, compact lens occupies but does not fill the optic cavity. The true structure of the material in the remainder of the optic cavity has not been determined. These eyes are compared to the descriptions of the cerebral ocelli of cephalopods, onychophorans, and phyllodocidan polychaetes.
The Tits boundary of a $\text {CAT}(0)$ 2-complex

We investigate the Tits boundary of CAT(0) 2-complexes that have only a finite number of isometry types of cells. In particular, we show that away from the endpoints, a geodesic segment in the Tits boundary is the ideal boundary of an isometrically embedded Euclidean sector. As applications, we provide sufficient conditions for two points in the Tits boundary to be the endpoints of a geodesic in the 2-complex and for a group generated by two hyperbolic isometries to contain a free group. We also show that if two CAT(0) 2-complexes are quasi-isometric, then the cores of their Tits boundaries are bi-Lipschitz.
Assessing predictive ability of three auroral precipitation models using DMSP energy flux

Our study statistically compares the total energy flux outputs of Newell et al.'s (2010a) oval variation, assessment, tracking, intensity, and online nowcasting (OVATION) Prime model, Hardy et al.'s (1991) Kp-based model, and a coupled Space Weather Modeling Framework ring current model to energy flux data obtained from 2198 Defense Meteorological Satellite Program (DMSP) satellite passes in the Northern Hemisphere. Our DMSP data set includes 28 days grouped into continuous 3 and 4 day periods between 2000 and 2008 and encompasses magnetic local times (MLTs) between 04:00 and 21:00. We obtain the most equatorward magnetic latitude coordinate, where a DMSP satellite energy flux measurement exceeds 0.4 erg/cm2/s, and use this point as a proxy for the equatorward boundary of the auroral oval in a particular MLT sector. We then calculate a prediction efficiency (PE) score by comparing the DMSP boundary coordinates to each model, using the same energy flux threshold to obtain a model's boundary location. We find that the PE for the OVATION Prime model is 0.55, and the PE for the Hardy Kp model is 0.51. When we accomplish the same analysis using a higher energy flux threshold equal to 0.6 erg/cm2/s, the OVATION Prime model's PE increases to 0.58, while the Hardy Kp model's score drops to 0.41. Our results indicate that more complex modeling techniques, like those used in OVATION Prime, can more accurately model the auroral oval's equatorward boundary. However, Hardy's discretized Kp model, despite its relative simplicity, is still a competitive and viable modeling option.
Has the trimethylene radical cation been observed?: An Ab initio molecular orbital study

Abstract Ab initio calculations have been performed on the cyclopropane radical cation and the trimethylene radical cation. The former radical cation has been claimed to undergo irreversible ring opening to the latter in CFCl 2 CF 2 Cl matrices at 80 K. However, the computational results reported here show that the energy of the cyclopropane radical cation is much lower than that of the (0,0) trimethylene radical cation, thus casting doubt on the possibility of irreversible ring opening of the former to the latter. It is suggested that the ring-opened species that is observed in the matrix by EPR has a nucleophile strongly coordinated to the carbocationic center.
Conference Report: Workshop on "Discourse—Knowledge—Culture" / Workshop on "Applied Discourse Analyses

Der – analog zu zwei vorangegangenen Tagungen in den Jahren 1999 und 2000 – vom Augsburger/Munchener Arbeitskreis Diskursanalyse und der DGS-Sektion Wissenssoziologie veranstaltete Workshop "Diskurs – Wissen – Kultur" verfolgte in theoretischer und methodischer Hinsicht die Frage nach dem Zusammenhang von Diskursen, der gesellschaftlichen (Re-) Produktion von Wissen und der Bedeutung von Kultur. Insbesondere ging es dabei um die Auseinandersetzung mit Ansatzen und Entwicklungen, die fur oder gegen eine Vermittlung zwischen der franzosischen Tradition von Diskursanalyse (entlang und in Fortfuhrung der FOUCAULTschen Perspektive) und aktueller Beitrage zur Wissenssoziologie in Deutschland sprechen. Der zweite Themenschwerpunkt der Veranstaltung richtete sich auf die Moglichkeiten und Grenzen angewandter Diskursforschung, wobei verschiedene Beitrage der Teilnehmer/innen insbesondere auch praktische Probleme bei der Durchfuhrung und Ergebnisprasentation von Diskursanalysen ins Zentrum ruckten. Dem entsprechend bot der zweite Workshop im Juni 2004 die Moglichkeit zur gemeinsamen Diskussion von laufenden Forschungsprojekten der Teilnehmer/innen, um so die eigenen theoretischen Positionen, methodologischen Fundamente und methodischen Herangehensweisen prufen und absichern zu konnen. URN: urn:nbn:de:0114-fqs0403388
Acceleration of the Cleavage in Sea Urchin Eggs by Treatmentswith Local Anesthetics (I) Procaine Treatment*. (acceleration of cleavage/local anesthetics/procaine/sea urchin eggs)

Unfertilized sea urchin eggs were pre-treated with 2–10 mM procaine sea water for 10 min and then fertilized 5 min later. These eggs hatched about 1–1.5 hr earlier than the control eggs. This acceleration of hatching seems to be the result of a reduction in the individual cleavage cycles. In the second series of experiments, eggs were inseminated at 5, 30 and 60 min after the procaine treatments. In this case, the rate of accelerated cleavage decreased gradually, as the intervals between the treatments and insemination were extended. Next, the minimum time-length of procaine treatment to accelerate cleavage was determined. When eggs were immersed in procaine for 1 min, cleavage was accelerated as in the case of 10 min-treatment, although acceleration to the same degree required higher concentrations of procaine solution. When fertilized eggs were post-treated with procaine, cleavage was also accelerated, but both the rate of acceleration and the effective concentrations decreased with time after fertilization.
Role of Bioactivation Reactions in Chemically Induced Nephrotoxicity

Kidneys express a diverse array of enzymes that can catalyze the bioactivation of many drugs and xenobiotics. The kidneys are particularly susceptible to chemically induced toxicity because of their basic physiology and biochemistry. The article discusses the role of bioactive reactions in chemically induced nephrotoxicity. Keywords: nephrotoxicity; xenobiotics; kidney; bioactive reactions; drug toxicity
THE GROWTH ADVANTAGE CONFERRED BY HIV-1 NEF IS DETERMINED AT THE LEVEL OF VIRAL DNA FORMATION AND IS INDEPENDENT OF CD4 DOWNREGULATION

Recent data on the phenotype of nef-defective HIV-1 in vitro indicate a new function of the Nef gene product: enhancement of viral infectivity. Single-cycle replication studies have suggested that Nef enhances the efficiency of an early step during viral replication, a step that leads to the establishment of viral DNA. To test this interpretation, the accumulation of low-molecular-weight (unintegrated) viral DNA was measured in cells following exposure to wild-type and nef-defective viruses. nef-defective virus accumulated less DNA than the wild type. This difference was observed after as little as 5 hr of exposure to virus. However, the reverse transcriptase activities of wild-type and nef-defective viruses were equal when measured in cell-free assays using either exogenous or endogenous templates. In addition, the abilities of these viruses to bind and enter cells were not significantly different. Together, these data suggest that Nef optimizes postentry events that are required for efficient synthesis of viral DNA. To determine if these effects were related to the property of Nef-mediated downregulation of CD4, growth curves of these viruses were determined using cells that express a CD4 molecule unable to respond to Nef. nef-defective virus remained attenuated in these cells, indicating that Nef-mediated downregulation of CD4 is not required for Nef-mediated enhancement of viral propagation in vitro.
Short course antibiotic therapy for respiratory infections: a review of the evidence.

Background. The judicious use of antibiotics entails achieving the appropriate balance between prescribing them with sufficient frequency and duration to effect a clinical cure for bacterial infections and overprescribing them, a practice that increases prescription drug costs as well as the risks of bacterial resistance, non-compliance with therapy and side effects. The recognition that the traditional 10-day or greater duration of therapy for acute otitis media, tonsillopharyngitis and sinusitis does not derive from a strong scientific or medical rationale (with the exception of penicillin therapy for tonsillopharyngitis) and the increasing awareness of the adverse sequelae of long-duration antibiotic therapy have led some clinicians to call for shortening the duration of antibiotic therapy in these infections. The soundness of this recommendation hinges on the demonstration that shortened courses of antibiotic therapy are at least as effective as traditional courses of therapy. Synopsis. Data relevant to determining the optimum duration of therapy in acute otitis media, tonsillopharyngitis and sinusitis are reviewed in this article. The review demonstrates particularly strong justification for shortening the duration of therapy from the standard 10 days to 5 days in acute otitis media, in which numerous open label and controlled studies have shown equivalent efficacy of the two durations of regimen. A growing body of evidence indicates that tonsillopharyngitis, too, can be effectively treated with non-penicillin antibiotics given for fewer than 10 days. Although sinusitis data are less plentiful than those for acute otitis media and tonsillopharyngitis, the results available to date are encouraging in suggesting that shortened courses of therapy may also be appropriate for acute maxillary sinusitis.
Modification of the HER2/NEU-derived tumor antigen GP2 improves induction of GP2-reactive cytotoxic T lymphocytes.

GP2 (IISAVVGIL), the p654–662 HER2/neu-derived tumor antigen, induces HLA-A2-restricted cytotoxic T lymphocytes (CTL) reactive to various epithelial cancers. The binding affinity of GP2 for HLA-A2, however, is very low. To improve the immunogenicity of GP2, we tested 10 different amino acid substitutions into GP2 at the C- and N- terminus. Five out of 10 modified peptides, especially those containing phenylalanine at position 1 (1F), showed a significantly improved binding affinity to HLA-A2. 1F-based modified peptides were well recognized by GP2-specific CTL. These peptides were used to stimulate peripheral blood lymphocytes from HLA-A2 healthy donors using peptide-pulsed autologous dendritic cells (DC). After 3 or more weekly stimulations, CTL activity against GP2 pulsed T2 (T2-GP2) and HER2/neu-overexpressing tumor cells was measured in 51Cr release and IFN-γ secretion assays. The modified peptides significantly enhanced GP2-specific CTL activity in some donors. In particular, the peptide with phenylalanine at position 1, leucine at position 2 and valine at position 10 (1F2L10V) maximized the CTL activity against both T2-GP2 and HER2/neu-positive tumor cells. Peptide 1F2L10V increased not only the binding affinity to HLA-A2 but also improved recognition of GP2. These data suggest that DC + modified GP2 may improve immune therapies for the treatment of HER2/neu overexpressing tumors. © 2001 Wiley-Liss, Inc.
Investigation of thermal transport in colloidal silica dispersions (nanofluids)

Thermal conductivity enhancement in colloidal silica dispersions (nanofluids) is investigated experimentally using a novel optical technique. The effects of nanoparticle size, concentration, and state of aggregation are examined. New data on well dispersed systems are compared to published data obtained using the more conventional transient hot-wire technique and good agreement was found. Experimental results are also compared with model predictions for relative thermal conductivity based on effective medium theory. For systems composed of larger diameter nanoparticles (~30 nm), good agreement was found between the measured thermal conductivity enhancement and that predicted by the classical Maxwell-Garnett model. For systems composed of smaller nanoparticles (∼10 and 20 nm), thermal conductivity enhancement was reduced by as much as 10%, presumably because interfacial thermal resistance effects become important. Measurements on two systems that were induced to form gels exhibited an increase in thermal conductivity of approximately 5% relative to the well-dispersed systems. The observed increase in thermal conductivity is larger than that predicted by a recently proposed model for aggregated nanofluids.
Design and Operation of an Electrochemical Methanol Concentration Sensor for Direct Methanol Fuel Cell Systems

The development of a 150-Watt packaged power source based on liquid feed direct methanol fuel cells is being pursued currently at the Jet propulsion Laboratory for defense applications. In our studies we find that the concentration of methanol in the fuel circulation loop affects the electrical performance and efficiency the direct methanol fuel cell systems significantly. The practical operation of direct methanol fuel cell systems, therefore, requires accurate monitoring and control of methanol concentration. The present paper reports on the principle and demonstration of an in-house developed electrochemical sensor suitable for direct methanol fuel cell systems.
Breaking the One Second Barrier: Fast Kinetics of Protein Adsorption by FT-IR

The Battelle Biological Spectroscopy Facility is currently studying the adsorption of blood proteins onto various surfaces using the combination of Fourier transform infrared spectroscopy (FT-IR) and attenuated total reflectance (ATR) optics. We have advanced our capabilities to study this phenomenon to the point where useful infrared spectra are obtained at 0.8-s intervals. This high-time resolution is helping to probe more accurately these important blood-surface interactions.
Meta-analysis of functional neuroimaging studies of emotion perception and experience in schizophrenia.

Background Neuroimaging studies of emotion in schizophrenia have reported abnormalities in amygdala and other regions, although divergent results and heterogeneous paradigms complicate conclusions from single experiments. To identify more consistent patterns of dysfunction, a meta-analysis of functional imaging studies of emotion was undertaken. Methods Searching Medline and PsycINFO databases through January 2011, 88 potential articles were identified, of which 26 met inclusion criteria, comprising 450 patients with schizophrenia and 422 healthy comparison subjects. Contrasts were selected to include emotion perception and emotion experience. Foci from individual studies were subjected to a voxelwise meta-analysis using multilevel kernel density analysis. Results For emotional experience, comparison subjects showed greater activation in the left occipital pole. For emotional perception, schizophrenia subjects showed reduced activation in bilateral amygdala, visual processing areas, anterior cingulate cortex, dorsolateral frontal cortex, medial frontal cortex, and subcortical structures. Schizophrenia subjects showed greater activation in the cuneus, parietal lobule, precentral gyrus, and superior temporal gyrus. Combining across studies and eliminating studies that did not balance on effort and stimulus complexity eliminated most differences in visual processing regions as well as most areas where schizophrenia subjects showed a greater signal. Reduced reactivity of the amygdala appeared primarily in implicit studies of emotion, whereas deficits in anterior cingulate cortex activity appeared throughout all contrasts. Conclusions Processing emotional stimuli, schizophrenia patients show reduced activation in areas engaged by emotional stimuli, although in some conditions, schizophrenia patients exhibit increased activation in areas outside those traditionally associated with emotion, possibly representing compensatory processing.
Generation of three-dimensional boundary-fitted curvilinear coordinate systems for wing/wing-tip geometries using the elliptic solver method

A three-dimensional elliptic solver technique is utilized to generate surface-fitted coordinates about wing/wing-tip configurations. The method is applicable to wings of arbitrary section profile and camber, leading-edge sweep, taper ratio, and spanwise thickness variation. The basic theory of three-dimensional elliptic mappings is developed along with a method to compute interior coordinate control functions. Examples of grids generated about several wing/wing-tip geometries are given. A 49 x 33 x 17 grid requires about 3 minutes of CPU time on a CYBER 203 computer.
Dihydroacacipetalin–a new cyanogenic glucoside from Acacia sieberiana var. Woodii

Abstract The structure of a new cyanogenic glucoside, dihydroacacipetalin has been established, primarily on the basis of NMR and mass spectral data. This compound co-occurs with acacipetalin and is also derived from l -leucine in the plant Acacia sieberiana var. woodii (Leguminosae).
Delineating a Conserved Genetic Cassette Promoting Outgrowth of Body Appendages

The acquisition of the external genitalia allowed mammals to cope with terrestrial-specific reproductive needs for internal fertilization, and thus it represents one of the most fundamental steps in evolution towards a life on land. How genitalia evolved remains obscure, and the key to understanding this process may lie in the developmental genetics that underpins the early establishment of the genital primordium, the genital tubercle (GT). Development of the GT is similar to that of the limb, which requires precise regulation from a distal signaling epithelium. However, whether outgrowth of the GT and limbs is mediated by common instructive signals remains unknown. In this study, we used comprehensive genetic approaches to interrogate the signaling cascade involved in GT formation in comparison with limb formation. We demonstrate that the FGF ligand responsible for GT development is FGF8 expressed in the cloacal endoderm. We further showed that forced Fgf8 expression can rescue limb and GT reduction in embryos deficient in WNT signaling activity. Our studies show that the regulation of Fgf8 by the canonical WNT signaling pathway is mediated in part by the transcription factor SP8. Sp8 mutants elicit appendage defects mirroring WNT and FGF mutants, and abolishing Sp8 attenuates ectopic appendage development caused by a gain-of-function β-catenin mutation. These observations indicate that a conserved WNT-SP8-FGF8 genetic cassette is employed by both appendages for promoting outgrowth, and suggest a deep homology shared by the limb and external genitalia.
A rapid-scanning electron paramagnetic resonance spectrometer with stopped-flow mixing

Abstract Modifications to a commercial electron paramagnetic resonance (e.p.r.) spectrometer are described which allow data to be obtained from 64 e.p.r, spectra (0.1–100 gauss per scan) with scan times of 0.010–0.900 s and with 0.020–900 s delay times between scans. Reagents are delivered into an e.p.r, cell from a stopped-flow mixer that triggers the generation of a microprocessor-controlled waveform to drive a rapid-scan unit. This digitally synthesized waveform is designed to correct inherent imperfections in the Helmholtz-type sweep coil circuit in the rapid-scan unit. The spectra are digitized (250 points per scan) and can be processed to determine rates of reaction. Performance of the system is demonstrated by the determination of the kinetics of rearrangement of a bis(di- peptide)nickelate(III) complex.
Unexpected formation of 2′-deoxy-N3-(3,3,3-trifluoro-1-propenyl)uridine via a Michael-type addition to 3,3,3-trifluoropropyne

Abstract Reaction of 3,3,3-trifluoropropyne with 2′-deoxy-5-iodouridine under conditions that have previously been used to prepare 5-alkynyl-2′-deoxyuridine derivatives gave 2′-deoxy- N 3-(3,3,3-trifluoro-1-propenyl)uridine. This unexpected alkylation is a result of a Michael-type addition of N 3 on the pyrimidine base to the electron deficient trifluoropropyne.
Personality, Sexuality, and Demographic Differences Between Volunteers and Nonvolunteers for a Laboratory Study of Male Sexual Behavior

Personality, sexuality, and demographic differences were examined in volunteers and nonvolunteers for a laboratory study of male sexual arousal. Subjects were 108 participants in a questionnaire study entitled “Personality and Sexuality,” who were then asked to volunteer for a second study which necessitated watching sexually explicit films, being partially undressed in an experimental chamber, and having penile diameter measured via a strain gauge device. Volunteers for the second study were found to be less guilty, less sexually fearful, more sexually experienced, and older than nonvolunteers. Volunteers also reported a higher incidence of past erectile difficulties and tended to be White or of mixed racial heritage, as opposed to being Oriental. Other personality variables did not discriminate between the two groups. The results indicate that future research in human sexuality using the laboratory analytic method must impose strict limits on generalization from the research data.
The τ-value, The core and semiconvex games

Theτ-value for cooperativen-person games is central in this paper. Conditions are given which guarantee that theτ-value lies in the core of the game. A full-dimensional cone of semiconvex games is introduced. This cone contains the cones of convex and exact games and there is a simple formula for theτ-value for such games. The subclass of semiconvex games with constant gap function is characterized in several ways. It turns out to be an (n+1)-dimensional cone and for all games in this cone the Shapley value, the nucleolus and theτ-value coincide.
Numerical simulations of detonations in hydrogen-air and methane-air mixtures

Detailed numerical simulations of supersonic reactive flow and gas phase detonation problems are very expensive due to their computer time and memory requirements. The bulk of this cost is in integrating the ordinary differential equations describing chemical reactions. A global induction parameter model has thus been developed which describes the chemical induction time of a mixture and allows for release of energy over a finite time period. The specific gases for which it has been calibrated are stoichiometric mixtures of hydrogen and methane in air. The relatively inexpensive induction parameter model is then used in time-dependent one- and two-dimensional simulations of supersonic reactive flows.
The 4-azepentalenyl anion

Abstract The simplest nitrogen heterocycle isoelectronic with the pentalenyl dianion is the 4-azapentalenyl anion (“azapentalenyl anion,” VI). The preparation and properties of this anion are described. It was prepared by reacting 3H-pyrrolizine (IX) in tetrahydrofuran (THF) with n-butyllithium, with potassium, and with sodium. That lithium, sodium, and potassium azapentalenide are ionic is indicated by the similarity of their PMR spectra in THF. The NMR and UV spectra of potassium azapentalenide are recorded in Figs 1 and 4. Lithium azapentalenide in THF reacts with benzophenone and with benzil to give fulvenes, X or XI. The anion is easily made and useful in preparing these derivatives, but the pKa of its conjugate acid, 3H-pyrrolizine, estimated to be 29 from the rate of exchange of its protons with deuterium oxide and triethylamine, is greater than anticipated on the basis of the Huckel MO theory.
Signature of bedload particle transport mode in the acoustic signal of a geophone

ABSTRACTThe purpose of this study is to develop a relationship for predicting the bedload rate from the acoustic signal of a geophone, under the rolling and saltating bedload transport modes. Controlled experiments corresponding to near-incipient, marginal, and general bedload motion were conducted. The geophone recorded impacts and resulting acoustic signal impulses at the lower “Frequency 1” (100–200 kHz) and the higher “Frequency 4” (380–480 kHz) ranges. Rolling particles produced stronger responses in Frequency 1 and weaker in Frequency 4 due to rotational vibrations. Instead, saltating particles generated stronger responses in Frequency 4 and weaker in Frequency 1 because of spheroid vibrations. The impulse in both Frequency 1 and 4 was related to bedload transport, as it accounts for the number and magnitude of the signal spikes due to the particle impacts. This study complements efforts for quantifying bedload transport using geophones by relating bedload to impulse for rolling and saltation.
Structural characteristics of bimetallic catalysts supported on nano-ceria

Cu-Pt bimetal catalysts supported on nanocrystalline CeO2 (nano-ceria) are synthesized via the low-cost sol-gel approach followed by impregnation processing. The average particle size of the catalytic composites is 63 nm. Ceria nanopowders sequentially impregnated in copper solution and then in Pt solution transformed into Pt-skin-structured Cu-Pt/ceria nanocomposite, based on the surface elemental and bulk compositional analyses. The ceria supporter has a fluorite structure, but the structure of Cu and Pt catalytic contents, not detected by X-ray diffraction spectroscopy due to the low loading level, is yet conclusive. The bimetallic catalytic nanocomposites may potentially serve as sulfur-tolerant anode in solid oxide fuel cells.
Autoradiographic localization of adenosine uptake sites in guinea pig brain using [3H]dipyridamole.

Abstract Tritiated dipyridamole, a specific adenosine uptake inhibitor binds in a saturable and reversible fashion to high-affinity receptor sites in guinea pig brain sections ( K d =10±1.5 nM; B max =650±100 fmol/mg prot.). The anatomical distribution of [ 3 H]dipyridamole binding sites obtained with autoradiographic techniques shows a widespread but heterogenous distribution of the binding sites throughout the whole guinea pig brain. Very high densities of binding sites are observed in the cerebellar cortex (molecular layer), the pyriform cortex, the superior colliculus (superficial layer), the supraoptic nucleus and the nucleus of the tractus solitarius. The anatomical characterization of the adenosine uptake site, using [ 3 H]dipyridamole as a probe, may be useful to determine the functional role of adenosine in the brain.
Hydrologic control of litter decomposition in seasonally flooded prairie marshes

The effect of seasonal inundation on the decomposition of emergent macrophyte litter (Scolochloa festucacea) was examined under experimental flooding regimes in a northern prairie marsh. Stem and leaf litter was subjected to six aboveground inundation treatments (ranging from never flooded to flooded April through October) and two belowground treatments (nonflooded and flooded April to August). Flooding increased the rate of mass loss from litter aboveground but retarded decay belowground. Aboveground, N concentration decreased and subsequently increased earlier in the longer flooded treatments, indicating that flooding decreased the time that litter remained in the leaching and immobilization phases of decay. Belowground, both flooded and nonflooded litter showed an initial rapid loss of N, but concentration and percent of original N remaining were greater in the nonflooded marsh throughout the first year. This suggested that more N was immobilized on litter under the nonflooded, more oxidizing soil conditions. Both N concentration and percent N remaining of belowground litter were greater in the flooded than the nonflooded marsh the second year, suggesting that N immobilization was enhanced after water-level drawdown. These results suggest different mechanisms by which flooding affects decomposition in different wetland environments. On the soil surface where oxygen is readily available, flooding accelerates decomposition by increasing moisture. Belowground, flooding creates anoxic conditions that slow decay. The typical hydrologic pattern in seasonally flooded prairie marshes of spring flooding followed by water-level drawdown in summer may maximize system decomposition rates by allowing rapid decomposition aboveground in standing water and by annually alleviating soil anoxia.
Choice-Based Segmentation As an Enrollment Management Tool

ABSTRACT This article presents an approach to enrollment management based on target marketing strategies developed from a choice-based segmentation methodology. Students are classified into “switchable” or “non-switchable” segments based on their probability of selecting specific majors. A modified multinomial logit choice model is used to identify “switchable” students and provides insight into the attributes that influence their choice.
Men Planning for Retirement Changing Meanings of Preretirement Planning

Using data from 69 in-depth interviews, the authors examine how men define financial planning and preretirement planning. The analyses show that younger men are less likely than older men to actively plan for retirement, and a clearer distinction is made between financial planning and preretirement planning. The results also show that the meanings of the two phrases overlap as one ages and that financial habits change over the life course. Understanding the changes over the life course would ensure that successful programs aim at securing financial security at older ages.
Cr, Co, Pd, Au, and In overlayers on PbS(100): Adatom interactions and interface formation.

High-resolution synchrotron-radiation photoemission has been used to investigate Cr-, Co-, Pd-, Au-, and In-adatom depositions at room temperature on cleaved PbS(100) single-crystal surfaces. In general, these adatoms induce disruption of the substrate but the growth morphology and the distribution of the released Pb and S atoms in the overlayer varies a great deal. The deposition of adatoms of Cr, Co, Pd, and Au in small amounts leads to the appearance of a chemically shifted Pd 5d core-level component and at high coverage there is substantial Pb segregation to the free surface. Pb segregation is greatest for Cr and diminishes for Co, Pd, and Au. This ordering reflects differences in the amount of substrate disruption (greatest for Cr, least for Au) and the low solubility of Pb in these metals. The S 2p core-level results also reveal chemical changes associated with Cr-sulfide formation and the dissolution of S in, and on, the growing metal overlayer (surface segregation is greatest for Pd and Au and least for Cr). In contrast, studies of the In/PbS interface show that In forms clusters, that there is some disruption of the substrate, that S is expelled to the surface, and that Pb is released into the In overlayer.
Treatment and assessment of pain in children with extremity fractures

Study objectives: Pain is the most common presenting complaint to US emergency departments (EDs). Despite this, the treatment and assessment of pain in children who present to the ED remain one of the more significant disparities in our field. The duty of emergency medicine nurses and physicians to quantify and provide relief from pain has been described in several consensus statements from groups including the American Pain Society, the American College of Emergency Physicians, and the Joint Commission on Accreditation of Healthcare Organizations. Despite these requirements, emergency medicine nurses and physicians frequently fail to meet the guidelines described by these agencies, particularly in the pediatric population. The purpose of this study is to describe the pain assessment and pain prescribing behaviors of emergency medicine nurses and physicians in pediatric patients with isolated extremity fractures. Methods: This was a retrospective medical record review in a large urban ED with an emergency medicine residency. Children aged 3 to 18 years and with an isolated extremity fracture were included. Children with multisystem trauma, hemodynamic instability, and documented Glasgow Coma Scale score less than 15 were excluded. Records were generated from an electronic database. Two abstractors obtained data using a standardized data sheet and prospectively derived rules. Each abstractor was trained before abstraction to ensure data fidelity. Results: One hundred fifty-three records were reviewed. Forty-one percent were for female patients. Ninety percent of patients were 5 years or older. Twenty-eight percent were black and 5% Hispanic. Twenty-seven percent were admitted for fracture repair or reduction. Pain was documented in 63% of nurse histories and 75% of physician histories but quantified only 19% of the time by nurses and 9% by physicians. Although 90% of medications dispensed in the ED were narcotics, only 55% of children received pain medications. White children were more likely to receive pain medications (63%) than nonwhite children (39%; P =.006 using Pearson χ 2 test). Conclusion: These data suggest that although ED staff tend to use narcotic medications for the treatment of pain from extremity fractures in this population, there remains a significant segment that does not have pain assessed or treated. Furthermore, these findings are more prevalent in ethnic minorities.
The influence of central search task luminance upon peripheral visual detection time

Twenty Ss were exposed to a wide range of luminances (8.5, 55, 792, 6,800 fL) of a centrally located diffuse white search panel. Each S attempted to detect the onset of seven randomly presented test lights (90, 60, 30 deg of arc left and right of 0 deg of arc along the horizontal meridian) concurrently with a continuous search task. The findings suggest that the visual field constricts with an increased central panel luminance. This is shown by an increased peripheral detection time (DT) and by more undetected peripheral test lights, even though the difficulty of the central search task was held constant. These results on the effect of an environmental stressor (high luminance) upon peripheral DT are related to findings from previous investigations as well as various applied situations.
The relationship between motivation, monetary compensation, and data quality among US- and India-based workers on Mechanical Turk

In this study, we examined data quality among Amazon Mechanical Turk (MTurk) workers based in India, and the effect of monetary compensation on their data quality. Recent studies have shown that work quality is independent of compensation rates, and that compensation primarily affects the quantity but not the quality of work. However, the results of these studies were generally based on compensation rates below the minimum wage, and far below a level that was likely to play a practical role in the lives of workers. In this study, compensation rates were set around the minimum wage in India. To examine data quality, we developed the squared discrepancy procedure, which is a task-based quality assurance approach for survey tasks whose goal is to identify inattentive participants. We showed that data quality is directly affected by compensation rates for India-based participants. We also found that data were of a lesser quality among India-based than among US participants, even when optimal payment strategies were utilized. We additionally showed that the motivation of MTurk users has shifted, and that monetary compensation is now reported to be the primary reason for working on MTurk, among both US- and India-based workers. Overall, MTurk is a constantly evolving marketplace where multiple factors can contribute to data quality. High-quality survey data can be acquired on MTurk among India-based participants when an appropriate pay rate is provided and task-specific quality assurance procedures are utilized.
Probabilistic considerations of creep crack growth

Abstract A tensile ligament instability model for creep controlled crack growth, based on Krafft, and Hart and Li, is used to illustrate the approach in formulating a mechanistically based probability model for life prediction. Such a model is needed for making statistically accurate estimates of service life for conditions not included within typical supporting design data. The approach and methodology for model development are described. The contributions and significance of selected fundamental variables for the deformation and failure processes are discussed.
Transdermal iontophoretic delivery of arginine-vasopressin (I): Physicochemical considerations

Abstract The enhancement in the transdermal delivery of arginine-vasopressin (AVP), a nonapeptide antidiuretic hormone (ADH), was studied using the Transdermal Periodic lontotherapeutic System (TPIS). The TPIS is capable of generating a pulse current at a specific combination of waveform, frequency and ON/OFF ratio. The in vitro permeation studies of AVP across the hairless rat skin was conducted under TPIS application and the results were compared with that by passive diffusion. Vasopressin was found to be relatively stable during the course of the experiment. The effect of pH and ionic strength of the donor solution and drug concentration on the AVP flux was evaluated. Under the application of TPIS, the transdermal delivery rate of AVP could be enhanced as much as 1000-fold and the degree of enhancement was noted to be dependent upon the physicochemical conditions used during the iontophoresis treatment. The flux of AVP at pH 5.0 and 7.4 was similar at constant ionic strength, but increased substantially as the ionic strength decreased. A linear relationship was established between AVP flux and AVP concentration in the donor compartment. The skin permeability enhanced by TPIS treatment is reversible and upon termination of iontophoretic application, the AVP flux was observed to return to that by passive diffusion alone.
Chiral recognition of 1,1′-binaphthyl-2,2′-diyl hydrogenphosphate using fluorescence anisotropy

Abstract The photophysical properties of 1,1′-binaphthyl-2,2′-diyl hydrogenphosphate (BNP) have been examined with particular emphasis to the effects of the chiral recognition of BNP by α-, β-, and γ-cyclodextrins (CDs). Fluorescence spectra and anisotropy values of the BNP enantiomers were measured in the presence and absence of the CDs under various conditions and the chiral recognition behavior are discussed based on the acquired fluorescence data. Small spectral shifts in the fluorescence emission allowed evaluation of the binding constant and enantioselectivity of the binding in β-, and γ-cyclodextrin, but significant shifts were not observed in the case of α-cyclodextrin. Fluorescence anisotropy proved to be an effective technique to study the enantioselective interactions, even in the case of α-cyclodextrin where a smaller binding constant and enantiodiscrimination were confirmed. The differential thermodynamics of binding were examined by fluorescence anisotropy and are discussed with reference to the general structural characteristic of the cyclodextrins examined. Interestingly, BNP was found to exhibit opposite thermodynamic trends for β-cyclodextrin at low (1 mM) and high (11 mM) cyclodextrin concentrations, indicating the possibility of complex of even different modes of enantiodiscrimination in this system.
Brownian dynamics simulations of bead-rod and bead-spring chains: numerical algorithms and coarse-graining issues

Abstract The efficiency and robustness of various numerical schemes have been evaluated by performing Brownian dynamics simulations of bead-rod and three popular nonlinear bead-spring chain models in uniaxial extension and simple shear flow. The bead-spring models include finitely extensible nonlinear elastic (FENE) springs, worm-like chain (WLC) springs, and Pade approximation to the inverse Langevin function (ILC) springs. For the bead-spring chains two new predictor–corrector algorithms are proposed, which are much superior to commonly used explicit and other fully implicit schemes. In the case of bead-rod chain models, the mid-point algorithm of Liu [J. Chem. Phys. 90 (1989) 5826] is found to be computationally more efficient than a fully implicit Newton’s method. Furthermore, the accuracy and computational efficiency of two different stress expressions for the bead-rod chains, namely the Kramers–Kirkwood and the modified Giesekus have been evaluated under both transient and steady conditions. It is demonstrated that the Kramers–Kirkwood with stochastic filtering is the preferred choice for transient flow while the Giesekus expression is better suited for steady state calculations. The issue of coarse graining from a bead-rod chain to a bead-spring chain has also been investigated. Though bead-spring chains are shown to capture only semi-quantitatively the response of the bead-rod chains in transient flows, a systematic coarse-graining procedure that provides the best description of bead-rod chains via bead-spring chains is presented.
Irreducible representations, symmetry coordinates, and the secular equation for line groups☆

Abstract The theory of irreducible representations of one-dimensional space groups is reviewed. Explicit directions for setting up representations are given and illustrated by examples. Symmetry coordinates and factoring of the secular equation for chain molecules are discussed.