cssi/SciSciGPT-SciSciNet huggingface dataset:
Adhesive Bonding and Corrosion Protection of a Die Cast Magnesium Automotive Door

It is well known that magnesium alloys, in close proximity to other alloys, are susceptible to galvanic corrosion. Combined with this fact, in automotive applications, it is rare that magnesium will be present in the absence of other alloys such as steel or aluminum. Therefore, in wet applications, where the galvanic cell is completed, it is necessary to isolate the magnesium in order to prevent accelerated corrosion. There are numerous commercial pre-treatments available for magnesium, however this paper focuses on conversion coatings in conjunction with a spray powder coat. By means of example, results for a hem flange joint on an AM50 die cast magnesium door structure will be presented. The outer door skin is an aluminum alloy hemmed around a cast magnesium flange. An adhesive is used between the inner and outer to help with stiffness and NVH (Noise, Vibration and Harshness). Results from bonded lap-shear coupon tests that have been exposed to accelerated corrosion cycles are presented. A second phase of this work considered a surrogate hem flange coupon, which was similarly exposed to the same accelerated corrosion cycle. Results from both of these tests are presented within this paper along with a discussion as to their suitability for use within automotive applications.
The fiscal body of sovereignty: to ‘make live’ in Indian country

Fiscal relations between the state and Indigenous peoples in Canada are a matter of life and death. By bringing to light techniques of economic rationality and governance of Indigenous peoples, thi...
High-Speed GC/MS of Gasoline-Range Hydrocarbon Compounds Using a Pressure-Tunable Column Ensemble and Time-of-Flight Detection

A pressure-tunable series-coupled ensemble of two capillary GC columns is combined with a time-of-flight MS detector for the high-speed characterization of mixtures containing hydrocarbon compounds. The column ensemble consists of a nonpolar 5% phenyl poly(dimethylsiloxane) column and a very polar poly(ethylene glycol) column. The TOFMS instrument uses time-array detection to obtain up to 500 complete electron mass spectra per second. Instrument software allows for automated peak finding and the spectral deconvolution of severely overlapping unknown chromatographic peaks, if their fragmentation patterns are significantly different and if at least two spectra can be recorded between the peak apexes. By adjusting the carrier-gas pressure at the column-junction point, the separations between adjacent peak pairs can be adjusted to enhance the capabilities of the TOFMS detector. The sensitivity of peak-pair separation to changes in junction-point pressure is studied for combinations of alkanes, olefins, and ar...
Depositing ordered arrays of metal sulfide nanoparticles in nanostructures using supercritical fluid carbon dioxide.

Silver sulfide and cadmium sulfide nanoparticles of controllable sizes are synthesized using a water-in-hexane microemulsion method and stabilized by dodecanethiol. The stabilized metal sulfide nan...
The relationship of total copper 48‐H LC50s to Daphnia magna dry weight

A study was conducted with Daphnia magna to determine the effect of neonate weight loss or lack of weight gain on experimentally derived copper 48-h LC50s. Standard unfed tests as well as algal-fed (Selenastrum capricornutum) tests were used to look at weight loss and gain. No significant relationship was found between amount of weight loss and copper LC50s. However, dry weight of unfed and algal-fed control organisms could be used to predict total copper LC50s.
The fundamental interaction of singing

This edition of the Nordic Journal of Music Therapy provides articles for two contrasting and eminently useful aspects of music therapy research with preterm infants. Friederike Haslbeck provides two articles to champion the lived experience of creative music therapy (CMT) for the preterm infant in the Neonatal Intensive Care Unit (NICU), while Garunkstiene and her team refine the application of live and recorded music for preterm infants. The studies epitomise the contrasting conceptualisation of music as an interpersonal process, and music as a stimulus...
Crayfish (Procambarus spiculifer) growth rate and final thermal preferendum

Abstract 1. 1|Crayfish growth rate was determined in a wild population and in the laboratory and compared to ambient temperatures. 2. 2|The largest growth increment/molt and the largest mean individual growth rate were observed when habitat temperatures were most similar to the final preferendum of the species. 3. 3|Growth slowed when temperatures exceeded the final preferendum.
Molecular and biophysical aspects of adaptation of life to temperatures below the freezing point

Abstract This review examines adaptation of life to temperatures below −2°C, from a biophysical point of view and relative to the properties of water. Different metabolic processes have different lowest temperatures. The lowest established temperature for photosynthesis and growth seems to be about −17°C. The review discusses membrane lipids from Antarctic microbial systems, and the limits to longevity of life in the cold, with coverage of permafrost microbial systems. It is directed towards readers of many backgrounds and supplements an earlier survey (L. Finegold, Adv. Space Res. 6, 257–264, 1986).
Altering the proportion of components in a mixed fixed-ratio schedule

Pigeons were trained under a schedule consisting of a number of fixed-ratio 100 components followed by a single fixed-ratio 10 component. The proportion of fixed-ratio 100 to fixed-ratio 10 components was varied according to several ascending and descending series within the range of 99:1 to 1:1. When this proportion was reduced to about 20:1 and below, the pause following each fixed-ratio 100 gradually decreased in length. Primes, a burst of responses at the start of the fixed-ratio 100 component, increased in frequency, and then decreased when the proportion became extremely low. Also, when the relative frequency of fixed-ratio 10 components was very high, primes were seldom observed in the first fixed-ratio 100 component following a fixed-ratio 10 component, but were distributed evenly throughout the remaining fixed-ratio 100 components.
State Equations for a Spacecraft With Maneuvering Flexible Appendages in Terms of Quasi-Coordinates

This paper is concerned with the derivation of the state equations of motion for a spacecraft consisting of a main rigid platform and a given number of flexible appendages changing the orientation relative to the main body. The equations are derived by means of Lagrange's equations in terms of quasi-coordinates. Assuming that the appendages represent distributed-parameter members, the state equations of motion are hybrid. Moreover, they are nonlinear. Following spatial discretization and truncation, the hybrid equations reduce to a system of nonlinear discretized state equations, which are more practical for numerical calculations and control design. To illustrate the effect of nonlinearity on the dynamic response during reorientation, a numerical example involving spacecraft with a membrane-like antenna is presented.
Minority Students in Gifted and Special Education Programs: The Case for Educational Equity

Inequities in education perpetuate disproportionality. Reform should stress the reexamination of policies and practices that produce these inequities. Variables affecting disproportionate minority representation in gifted and special education programs are addressed, including the definition of ethnicity, disability categories, and special education knowledge producers. Historical research synthesis providing an in-depth chronology of past reform efforts, current trends, proposed solutions, legislation and litigation, and statistical outcomes for various minority groups is stressed.
Children and the gendered politics of globalization: In remembrance of Sharon Stephens

Written to honor the memory of Sharon Stephens as an exceptional anthropologist this article focuses on her groundbreaking work of critically theorizing children and childhoods in relation to the politics of late capitalism and structures of modernity. Stephens's research into the contested category of childhood is here linked specifically to the location and uses of the figure of "the child" in the gendered politics of globalization, [children, childhood, globalization, gender, late capitalism, modernity, Cold War, "national security" discourses]
Optimal selection and sorting via dynamic programming

We show how to find optimal algorithms for the selection of one or more order statistics over a small set of numbers, and as an extreme case, complete sorting. The criterion is using the smallest number of comparisons; separate derivations are performed for minimization on the average (over all permutations) or in the worst case. When the computational process establishes the optimal values, it also generates C-language functions that implement policies which achieve those optimal values. The search for the algorithms is driven by a Markov decision process, and the program provides the optimality proof as well.
An Analytical Approach for Levee Underseepage Analysis

Summary Levee underseepage analyses are commonly performed to assess the risk of erosion and piping of levee foundation soils. They are also commonly used to estimate the quantity of seepage that is expected to pass beneath a levee over time, and to assess the risk of excessively high pore pressures at various points in the foundation. A variety of approaches have historically been utilized to perform steady-state underseepage analyses in levees, including flow-nets, closed-form analytical solutions, and numerical techniques such as finite difference or finite element analyses. This paper provides a derivation of a series of closed-form “blanket theory” analytical equations that can be used to perform a levee underseepage analysis. This derivation starts from a generic confined flow analytical solution, of the type that is common in groundwater flow analyses. The solution is then extended to simulate semiconfined flow beneath a levee in a shallow aquifer. Equations are presented for calculating total head and seepage quantity values for different model boundary conditions. A typical example problem is used to compare the analytical equations that are derived with the analytical equations that are presented in the US Army Corps of Engineers (USACE) levee design manual. The results provide validation for both the equations that are presented and the conventional USACE analytical design approach. Using the results from the example problem, general guidance and suggestions are provided for designers that use closed-form analytical approaches for modeling levee underseepage.
Sensitivity of Item Difficulties to Curricular Validity

The issue of the match of what is taught to what is tested recently has received increased emphasis. Many recent studies have examined the extent of the mismatch between a local set of objectives/instruction and the content of a nationally standardized test. Phillips and Mehrens (1985, 1987; see also Mehrens & Phillips, 1986) have conducted a series of studies that show that, within a district, different textbook series and informal curricula generally have no significant impact on test total, objective, or item scores. The present study explored further the curricular validity differences across textbooks and the relationship between item statistics and measures of curricular validity. In particular, this study sought to determine whether item p-values appear to be related to measures of curricular validity based on three mathematics textbook series used at a given grade and in a previous grade. The results of this study indicated that the textbooks differed somewhat in content coverage when using a 180-cell matrix classification. However, these differences were not great, especially when the textbooks in both grades 5 and 6 were considered. Further, all three series covered almost all of the 53 cells in the matrix covered by the Stanford Achievement Test, and the differences that did exist in textbook content coverage had no observable relationship to differences in item p-values. In addition, the mean difficulty level of the Stanford Achievement Test items classified by cell were similar for students using the different textbooks, despite the differences among textbooks in location, presentation, and organization of content.
Progressive Ocular Toxoplasmosis in Patients with Acquired Immunodeficiency Syndrome

We studied two patients, a 43-year-old Hispanic man with a one-year history of acquired immunodeficiency syndrome (AIDS) and a 34-year-old Hispanic man with newly diagnosed AIDS. Both had necrotizing retinitis that progressed to panophthalmitis and orbital cellulitis. Toxoplasmosis was not diagnosed in the first patient early in the course of the disease. The second patient had a history of toxoplasmic retinochoroiditis. Despite antitoxoplasmosis therapy, visual acuity deteriorated to no light perception in both patients. Diagnostic biopsy of the eye wall was performed on the first patient and enucleation of the globe on the second. Toxoplasmic panophthalmitis and orbital cellulitis were diagnosed in each patient by light microscopy and confirmed by electron microscopy. When patients with AIDS develop necrotizing retinitis, toxoplasmosis must be considered in the differential diagnosis, along with cytomegalovirus retinitis, progressive outer retinal necrosis, and syphilitic retinitis. Unlike cytomegalovirus retinitis, progressive outer retinal necrosis, and syphilitic retinitis, however, toxoplasmosis can cause a progressive intraocular infection, panophthalmitis, and orbital cellulitis in patients with AIDS.
Production Uncertainty and the Heckscher-Ohlin Theorem"2

Despite several recent contributions which have introduced uncertainty into general equilibrium models,3 trade theorists continue to assume that the economic environment is nonstochastic.4 One of the most fundamental theorems in trade theory is the HeckscherOhlin (HO) theorem which asserts that a country exports the commodities which are relatively intensive in the use of its relatively abundant factor. The purpose of this paper is to explore the implications of uncertainty in the production function for the validity of the HO theorem and its offspring, the factor-price equalization theorem. As a byproduct of our analysis, the Rybczynski theorem is also analysed. The HO theorem has been traditionally proved in terms of two alternative definitions of inter-country relative factor abundance, namely the " factor-price " definition and the " physical " definition. We show that the HO theorem cannot be proved in terms of the factor-price definition, but that the theorem is valid in terms of the physical definition even in the presence of uncertainty in the production process. The Rybczynski theorem also continues to hold, but the factor-price equalization theorem does not, even if all the assumptions made customarily for the validity of the theorem are satisfied. The reason for this turns out to be the producers' aversion towards risk.
Kalman Filter-Based Integrity Monitoring Against Sensor Faults

This paper introduces a new Kalman filter-based method for detecting sensor faults in linear dynamic systems. In contrast with existing sequential fault-detection algorithms, the proposed method enables direct evaluation of the integrity risk, which is the probability that an undetected fault causes state estimate errors to exceed predefined bounds of acceptability. The new method is also computationally efficient and straightforward to implement. The algorithm’s detection test statistic is established in three steps. First, the weighted norms of current and past-time Kalman filter residuals are defined as generalized noncentrally chi-square distributed random variables. Second, these residuals are proven to be stochastically independent from the state estimate error. Third, current-time and past-time residuals are shown to be mutually independent, so that the Kalman filter-based test statistic can be recursively updated in real time by simply adding the current-time residual contribution to a previously ...
Characterization of Two Seryl-tRNA Synthetases in Albomycin-Producing Streptomyces sp. Strain ATCC 700974

The Trojan horse antibiotic albomycin, produced by Streptomyces sp. strain ATCC 700974, contains a thioribosyl nucleoside moiety linked to a hydroxamate siderophore through a serine residue. The seryl nucleoside structure (SB-217452) is a potent inhibitor of seryl-tRNA synthetase (SerRS) in the pathogenic bacterium Staphylococcus aureus, with a 50% inhibitory concentration (IC(50)) of approximately 8 nM. In the albomycin-producing Streptomyces sp., a bacterial SerRS homolog (Alb10) was found to be encoded in a biosynthetic gene cluster in addition to another serRS gene (serS1) at a different genetic locus. Alb10, named SerRS2 herein, is significantly divergent from SerRS1, which shows high homology to the housekeeping SerRS found in other Streptomyces species. We genetically and biochemically characterized the two genes and the proteins encoded. Both genes were able to complement a temperature-sensitive serS mutant of Escherichia coli and allowed growth at a nonpermissive temperature. serS2 was shown to confer albomycin resistance, with specific amino acid residues in the motif 2 signature sequences of SerRS2 playing key roles. SerRS1 and SerRS2 are comparably efficient in vitro, but the K(m) of serine for SerRS2 measured during tRNA aminoacylation is more than 20-fold higher than that for SerRS1. SB-217452 was also enzymatically generated and purified by two-step chromatography. Its IC(50) against SerRS1 was estimated to be 10-fold lower than that against SerRS2. In contrast, both SerRSs displayed comparable inhibition kinetics for serine hydroxamate, indicating that SerRS2 was specifically resistant to SB-217452. These data suggest that mining Streptomyces genomes for duplicated aminoacyl-tRNA synthetase genes could provide a novel approach for the identification of natural products targeting aminoacyl-tRNA synthetases.
Local mode treatment of normal mode molecules: Application to CF2Cl2 overtone spectra

Abstract The CF stretching fundamental and overtone spectra are reported for CF2Cl2 for up to five vibrational quanta. A three-parameter local mode model accounts for both the frequencies and the relative intensities and provides a detailed description of the intramolecular dynamics following the excitation of a localized CF stretch.
Defects in oxygen implanted silicon

Abstract Silicon-based devices in their various representations use ion implantation for the electronic modification of the basic material. The defects and their formation by ion beam must be identified and minimized to obtain a useful product. We report the characterization of defects formed during oxygen implantation of silicon using conventional and high-resolution transmission electron microscopy. The effect of water temperature as the parameter most influential on type and density of defects was investigated. The study revealed that microtwins and stacking faults were created in the top silicon layer during implantation from 450–550°C. From 600–700°C, numerous multiply faulted defects were observed. They are 40 to 140 nm long and consist of several discontinuous stacking faults which are randomly spaced and separated by six to twelve atomic layers. In the substrate region beneath the buried oxide layer created by implantation, the defects observed included stacking faults and {113} defects. Some parts of the {113} defects show a twinning structure across {115} planes. Some are converted into a hexagonal structure. After annealing at 1300°C for 6 hours in argon, samples implanted at 450–575°C contain dislocation densities higher than those implanted 575°C. Details of the structure and formation mechanisms of these defects will be discussed.
"I swear by Apollo"--on taking the Hippocratic oath.

This spring, most U.S. medical schools will administer some type of professional oath to about 16,000 men and women who receive medical degrees. Dr. Howard Markel explains the complexities of the Hippocratic Oath.
Getting to know you: Face-to-face versus online interactions

It is an open question as to how impressions formed via computer-mediated communication (CMC) differ from those formed face-to-face (FtF). Some research suggests that judgments of others formed while interacting over CMC are more favorable than judgments formed in FtF, while other researchers argue the pattern is in the opposite direction. We sought to settle this conflict by examining impressions formed via each communication mode while controlling for the other. Participants interacted with a partner twice: once FtF and once CMC. When controlling for each communication mode, participants interacting FtF, formed more positive impressions of their partner than did those in the other sequence. Furthermore, FtF participants had greater self-other agreement then those who interacted via CMC. Implications for impressions formed over the Internet are discussed.
STUDIES ON A BACTERICIDAL AGENT EXTRACTED FROM A SOIL BACILLUS : III. PREPARATION AND ACTIVITY OF A PROTEIN-FREE FRACTION.

A cell-free extract of cultures of an unidentified soil bacillus, which exerts a bactericidal effect on Gram-positive microorganisms, has been described in previous reports; the first active preparations which were obtained were found to contain a protein precipitable at pH 4.5. It is shown in the present report that the bactericidal agent can be obtained in an active form free of protein. The new purified preparations retain all the activity of the original material, both in vitro and in vivo.
Intramuscular and oral disposition of enrofloxacin in African grey parrots following single and multiple doses

The intramuscular (IM) and oral (PO) disposition of enrofloxacin, a new fluoroquinolone antimicrobial drug, were evaluated in African grey parrots. Peak enrofloxacin concentration, mean (+/- SEM), at 1 h following a 15-mg/kg IM dose was 3.87 (+/- 0.27) micrograms/ml and declined with a mean residence time of 3.05 h. Peak enrofloxacin plasma concentrations at 2 to 4 h following oral doses of 3, 15, and 30 mg/kg were 0.31 (+/- 0.11), 1.12 (+/- 0.11), and 1.69 (+/- 0.23) micrograms/ml, respectively, and declined with a mean residence time of 3.44-5.28 h. The relative bioavailability of the 15-mg/kg oral dose was 48%. An equipotent metabolite, ciprofloxacin, was detected in plasma at concentrations ranging from 3 to 78% of those of enrofloxacin. Enrofloxacin concentrations and area under the curve were significantly lower, the mean residence time significantly shorter and the ciprofloxacin/enrofloxacin ratios higher, following 10 days of oral treatment at 30 mg/kg every 12 h. Following 10 days of treatment, no significant biochemical changes were noted; however, polydipsia and polyuria occurred in treated birds, but resolved quickly upon discontinuation of enrofloxacin administration. These studies indicate that a rational starting dose for enrofloxacin in psittacines (7.5-30 mg/kg BID) should be higher than those in other domestic animals.
A Large-Eddy Simulation Methodology in Generalized Curvilinear Coordinates

A generalized curvilinear coordinate formulation for the large-eddy simulation (LES) that centers on the fact that two spatial operations are necessary to complete the derivation is proposed. The recommended order of operations is to transform the full resolution system prior to filtering. This sequence rationally directs the filter operation along the curvilinear lines, thereby facilitating explicit evaluation of the Leonard stress and its isolation from the relative errors associated with the finite-difference approximations of the convective derivative. Representing the transformation metrics as filtered quantities in the formulation is justified through their numerical approximation. The generalized LES formulation was tested using direct numerical simulation results of the circular cylinder near wake at Re=3400. No discernible differences were detected in the spectral energies of the turbulent fluctuations by filtering in either the physical domain or the transformed space. However, the latter filtering scheme was considerably cheaper. In the transformed space, high-order numerical approximations are required for the convective derivatives to inhibit overshadowing of the concurrent contributions by the Leonard stress at all wave-numbers.
Late quaternary interglacial stages warmer than present

Abstract Literature on warm interglacials from both deep sea and continental records is reviewed. Although there is no unanimity, most deep sea data covering the late Quaternary (in this case, 500 ka to present) indicate that Oxygen Isotope Stage 11 (423-362 ka) was warmer than succeeding interglacials. Similarly, continental data imply warm intervals covering those interglacials between Stages 11 to 15 but with Stage 11 as the warmest. There are no direct data, however, to suggest that either the West Antarctic or Greenland Ice Sheets collapsed during warm interglacials. Indeed, recent work suggests that there may be a problem with assuming that collapse occurred as a result of, and during, a warmer than present interglacial; data from ice cores recovered on the Greenland Ice Sheet indicate that over the past 250 ka, excluding the last 8 ka, climate was unstable with rapid mode switches occurring during both glacials and interglacials and with modes lasting from 70 years to 5 ka. If warming is invoked as the underlying cause of collapse then warm intervals may not have been long enough to cause substantial melting. This suggests that, along with warmer than present interglacials, alternate mechanisms invoking forcing internal to the ice sheet and its substrate be seriously considered. Future studies should focus on these alternate mechanisms as well as on the interval equivalent to Oxygen Isotope Stage 11.
CO2-laser-induced breakdown in mono- and diatomic gases

Several monoatomic and homonuclear diatomic gases absorb energy from a focused CO2-laser photon field. It has been established that the pressure threshold for the energy absorption correlates qualitatively with the known ionization potentials of those gases. The simplified phenomenological theory of the CO2-laser-induced dielectric breakdown of gases is invoked to explain this phenomenon. In the H2−D2 system, the formation of HD is observed under these conditions. The examination of the reaction yields for HD formation demonstrates that the system studied does not reach equilibrium under our experimental conditions. Considerations regarding kinetics of primary processes reveal that ionic species, created originally via an inverse bremsstrahlung mechanism, are converted into atomic transients in fast ionic association processes. The latter species initiate chain reactions with surrounding molecules of substrates leading to the formation of HD. Simple kinetic analysis based on a non-steady-state assumption permitted the derivation of an expression for the yield of HD formation. This equation was fitted to the experimental data assuming that the temperature of the reaction rises with an increase of the amount of D2 in the mixture. Some other aspects regarding the behavior of this system in a focused CO2 laser beam are also discussed.
Hypothalamic-Midbrain Dysregulation Syndrome: Hypertension, Hyperthermia, Hyperventilation, and Decerebration:

Certain decerebrate lesions of brain stem or hypothalamus induce pharmacologically reversible hypertension and hyperthermia in animals. We observed three young patients with episodic decerebration, hyperthermia, hypertension, and hyperventilation during recovery from comas of different etiologies. The shared pathology on neurologic examinations and computed tomographic scans was hypothalamic-mesencephalic dysfunction, suggesting a diencephalic-brain-stem disconnection syndrome or brain-stem release mechanism. Propranolol was the most effective drug tested, but only two patients responded, one dramatically. This novel clinical syndrome may have localizing and therapeutic significance in pediatric coma that needs to be further defined in future studies. (J Child Neurol 1991;6:115-122).
Experimental investigation of natural convection heat transfer of Al2O3 Nanoparticle Enhanced Ionic Liquids (NEILs)

Abstract Experimental investigations were carried out regarding natural convection heat transfer of Nanoparticle Enhanced Ionic Liquids (NEILs) in rectangular enclosures of two different sizes with dimensions length × width × height, 50 × 50 × 50 mm and 50 × 50 × 75 mm in heated from below. The NEILs were synthesized by dispersing different wt% (0.5, 1.0, and 2.5) of aluminum oxide (Al2O3) nanoparticles of two different particle shapes (spherical and whiskers) into N-butyl-N-methylpyrrolidinium bis{(trifluoromethyl)sulfonyl} imide, ([C4mpyrr][NTf2]) ionic liquid (IL). Heat transfer related thermophysical properties, i.e. density, viscosity, thermal conductivity, and heat capacity of base IL and NEILs were also measured and reported. The experimental measurement shows enhanced density, thermal conductivity, viscosity, and heat capacity of NEILs compared to the base IL and they increase with the nanoparticle concentration. However natural convection heat transfer coefficient was observed to deteriorate for the NEILs compared to the base IL irrespective of the shapes of the particles and aspect ratio of the enclosure and the deterioration increases with the increase of nanoparticle concentration. Interestingly spherical Al2O3 NEILs was observed to affect more adversely compared to the whiskers Al2O3 NEILs. The observed degradation of the heat transfer performance of the NEILs could not fully be explained by the change of thermophysical properties, which indicates that other factors may play significant roles in this phenomenon and the possible reasons of the degradation is discussed in this paper.
The Thresholding Greedy Algorithm, Greedy Bases, and Duality

Some new conditions that arise naturally in the study of the Thresholding Greedy Algorithm are introduced for bases of Banach spaces. We relate these conditions to best n-term approximation and we study their duality theory. In particular, we obtain a complete duality theory for greedy bases.
Endogenous signaling pathways and chemical communication between sperm and egg

Red abalone (Haliotis rufescens) sperm detect a waterborne chemical cue released by conspecific eggs, and change their swimming behavior to increase the likelihood of fertilization success. Previously, we isolated the natural sperm attractant by bioassay-guided fractionation and high-performance liquid chromatography, and chemically identified it as the free-amino acid l-tryptophan (l-Trp). In the present study, levels of this ecologically meaningful compound were quantified in various abalone tissues, and in freshly spawned eggs. Tryptophan was the least abundant of 19 dissolved free amino acids (DFAAs) in ovary, testis, foot muscle, gill, stomach and hemolymph. As a proportion of the DFAA pool, however, Trp concentrations were significantly elevated in eggs (three- to seven-times higher) relative to all other sampled tissues. Natural rates of Trp release from eggs also were measured and correlated with fertility. Fertilization success peaked during an initial 30 min period (post-spawn), but decreased to nil over the next 50 min. Closely paralleling these events, Trp accumulated in seawater around freshly spawned eggs for the first 45 min (post-spawn) before decaying rapidly from solution. Older eggs stopped releasing Trp approximately when they became infertile, revealing a critical link between gamete physiology and chemical signaling. This apparent negative feedback loop did not arise from tryptophan oxidation, uptake by bacteria in seawater, or a degrading enzyme released by eggs. As a metabolic precursor critical to development of the larval nervous system, Trp could be an honest indicator of egg fitness for prospective sperm suitors. Our results suggest that endogenous signaling pathways have been co-opted for external communication between gametes, as an adaptation to increase reproductive success by promoting sperm navigation towards fertile eggs.
Computer-Aided Formulation of Silica Defoamers for the Paper Industry

In the manufacture of paper, wood chips are "cooked" in a vat of chemicals that has a tendency to boil over, much like spaghetti cooked in a pot of water. An important use of precipitated silica, fine particle silicon dioxide a noncrystalline form of sand, is in eliminating such foams from industrial processes. To be effective, the silica must be dispersed, often in a mixture of mineral oil and other chemicals. Based on an empirical equation of the defoamer's performance as well as on a deterministic equation of ingredient cost, I developed a nonlinear programming model for optimal performance. Paper manufacturers confirmed the validity of the predicted optimal formula in four out of five paper plant trials.
Comment: Alternative Strategies for Experimental Design

Commentary based on the article, "Experimental Design for Engineering Dimensional Analysis" by Mark C. Albrecht, Christopher J. Nachtsheim, Thomas A. Albrecht & R. Dennis Cook published in the journal Technometrics, volume 55, issue 3.
Stimulation of fire ant queen fecundity by a highly specific brood stage.

Fourth instars of the fire ant, Solenopsis invicta Buren, stimulate ovarian development and egg-laying in the queen. Fourth instars were separated into feeding, meconium-forming, postmeconial, and pupal stages, and each was tested for their effect on queen fecundity. Meconial-stage brood stimulated queens to lay eggs 60-170% faster than the other stages, which suggests that the stimulatory factor is released mainly at meconium formation. For brood to be effective, brood and queens must be present in the same nest. The effect of brood stage on ovarian development was significant only under some circumstances. Behavioral observations indicate that a certain group of workers repeatedly collects an unknown material from the anus of pharate pupae and proceeds more or less directly to the queen retinue, where they offer trophallactic exchange to the queen. Neither larva-tending nor most queen-tending workers shuttle in this manner. Results suggest that a specialized group of workers transfers a fecundity-stimulating anal factor from early postmeconial brood to the queen.
Longitudinal assessment of the effects of oestrogen on blood pressure and cardiovascular autonomic activity in female rats.

1. Published data concerning the effect of ovarian hormones on hemodynamic variability is contradictory. This study employed, for the first time, radiotelemetric hemodynamic monitoring to investigate the long-term effects of chronic estrogen depletion and repletion on cardiovascular autonomic control and arterial baroreflex sensitivity (BRS) in female rats. 2. Blood pressure (BP), heart rate (HR), and +dP/dtmax of arterial pressure (an estimate of myocardial contractility) were monitored in sham-operated (SO), ovariectomized (OVX), and estrogen-replaced OVX rats (OVXE2) for 16 weeks. Cardiovascular autonomic control and baroreflexes were assessed by frequency domain analysis of interbeat intervals (IBI) and systolic BP (SBP). 3. Compared with SO rats, OVX rats exhibited (i) no changes in BP, (ii) short-lived decreases in HR, and (iii) sustained reductions in dP/dtmax of arterial pressure. The high frequency (HF, 0.75-3 Hz) and low frequency (LF, 0.25-0.75 Hz) components of spectral power of IBI were significantly decreased and increased, respectively, by ovariectomy. An increase in the IBILF/HF ratio in OVX rats suggested a shift in the cardiac sympathovagal balance towards sympathetic dominance. Index α, the spectral index of spontaneous BRS, was reduced by OVX. 4. Estrogen replacement caused significant reductions in BP and HR and reversed OVX-induced changes in +dP/dtmax of arterial pressure and cardiac autonomic activity. The LF oscillations of SBP were reduced in OVX-E2 treated rats, suggesting a reduction in vascular sympathetic tone by estrogen. 5. These findings highlight the importance of long-term estrogen therapy in rectifying the detrimental cardiovascular and baroreflex influences caused by depletion of ovarian hormones.
Working memory deficits in current and previous users of MDMA ('ecstasy').

Current and previous users of the drug MDMA (‘ecstasy’) were tested on measures of central executive functioning, information processing speed, and on self-report measures of arousal and anxiety. The results were compared with those for a control group who did not use MDMA. Relative to the control group, both user groups were found to be impaired in some aspects of central executive functioning. Also, there were significant group differences on the measures of anxiety (users were more anxious) and on arousal (previous users scoring higher on the arousal measure relative to current users). Users processed information as quickly as non-users but less accurately. Some possible mediators of the above group differences are discussed.
Modification of the macaque's vestibulo-ocular reflex after ablation of the cerebellar vermis.

In macaque, the vestibulo-ocular reflex (VOR) as evaluated by the time constant of nystagmus in a modified Barany spinning test, shows a regular pattern of change with time after ablation of the vermis cerebelli. One day ablation the time constant is in the low normal range; it then increases, and after one week assumes values in the high normal range. While the time constant is high, the VOR is resistant to modification by repeated testing, but may be modified by unidirectional optokinetic nystagmus and by experience with reversing spectacles. These results suggest that the vermis of the cerebellum plays no crucial role in modifications of the VOR by visual inputs, but is involved when the VOR is modified by repeated vestibular experience.
Sister Malia Tu‘ifua: Descendant of Chiefs, Daughter of God

This portrait of Sister Tu'ifua (1924-2007), explores the life of high-ranking Halakihe'umata Tu'ifua from her inauspicious birth in Lapaha, Tonga, to her profession in becoming a Roman Catholic nun and her subsequent work for the church. The account details several features of her early life: her love of dancing and performing, her interaction with American servicemen during the Second World War, and her reason for becoming a nun. It then follows Sister Tu'ifua's career: teaching children, development work with Tongan women and, latterly, her international role and work for the betterment of the poorest of Tongan people.
Dependence of the Emittances of the Fermilab Injectors on Intensity

This paper reports the dependence of the emittance of the Main Ring injected beam on Booster intensity. The intensity was changed in two different ways: by changing the number of turns injected into the Booster using the normal H- charge-exchange injection and by changing the intensity of the Linac itself by varying the phase of the buncher. The measured emittance of the Linac beam was also compared, assuming adiabatic shrinkage, to the emittance of the Main Ring beam measured while injecting one turn into the Booster.
On principal noise of the laser Doppler velocimeter

The principal noise of the Laser Doppler Velocimeter is shown to be due to transit broadening rather than the most commonly suggested signal shot; the phase ambiguity noise is also shown as less serious for the dual-beam Laser Doppler Velocimeter. On the basis of optical geometry and Fourier analysis of electric fields interacting with moving particles, the transit broadening noise has been calculated; some supporting experimental evidence is also discussed along with means for reducing this principal noise.
The transferrins and hemoglobins of bighorn sheep (Ovis candensis), dall sheep (Ovis dalli) and mouflon (Ovis musimon)

Abstract 1. 1. Transferrins and hemoglobins of Ovis canadensis, Ovis dalli and Ovis musimon were analyzed by electrophoresis and compared with domestic sheep reference transferrins and hemoglobins. 2. 2. The following Tf's were observed: Tf's D and E in O. canadensis ; Tf D in O. dalli ; and Tf's C, D and E in O. musimon . Tf B + , perhaps characteristic for wild sheep, was identified in all three species. 3. 3. Hbg B characterized O. canadensis, O. dalli and O. musimon .
IMMUNOGENETICS OF TYPE I DIABETES MELLITUS

Type I (insulin-dependent) diabetes mellitus (IDDM), is generally considered to be an autoimmune disease based on: 1) the finding of numerous inflammatory cells in the islets of Langerhans at the onset of the disease; 2) the presence of circulating autoantibodies directed against the islet cells; and 3) the fact that immunosuppressive agents, such as cyclosporin A, are able to transiently block the course of the disease. Moreover, the observation that certain HLA class II alleles are associated with an increased risk for the disease, supports an autoimmune etiology for IDDM. In particular, the absence of aspartic acid in position 57 of the HLA-DQβ and the presence of arginine in position 52 of the DQα chain together, have been found to be strongly associated with IDDM in population studies. These heterodimers have been thought to play an important role in the pathogenesis of IDDM. In fact, the HLA class II molecule participates in a complex interaction between the processed foreign antigen and the T cell receptor (TCR) molecule, which starts the immune response. As the result of a stochastic rearrangement among variable (V), diversity (D), joining (J) and constant (C) gene segments encoding both α and β chains, the TCR may assume 1010 different configurations. If IDDM is provoked by a single antigen, a restricted set of T cell clones should emerge during the destruction of the insulin producing β cells. However, this phenomenon is difficult to study because T cells from the pancreas of patients with IDDM, at the onset of the disease, are required to characterize this process. We had the opportunity to study the pancreas of a newly diagnosed child with IDDM who unfortunately died of brain swelling during treatment of diabetic ketoacidosis. T cells from isolated islets were characterized based on their expression of different TCR Vβ regions. The presence of a remarkably restricted TCR Vβ repertoire of the T cells infiltrating the pancreatic islets of this patient strongly suggests the involvement of superanrigens in the etiology of IDDM
Mutual Learning and Democratic Action in Instrumental Music Education

This ethnography is an investigation of the notion of democracy as community-in-the-making. The researcher and nine band students came together to create music that was meaningful and self-reflective. The participants elected to split into two distinct ensembles. Group 1 chose not to compose on their primary band instruments, opting for electric guitar, bass, synthesized piano, and drums. Group 2 chose to create music using traditional concert band instruments. Choosing a genre and working with the traditions governing its creative processes seemed to be the largest determinant of a groups culture. The group members and researcher saw classical music as unproductive for group composing or community-making. Composing in a jazz or popular style was conceived of as fun, nonobligatory, self-directed, and personally meaningful. In such settings, there was an emphasis on interpersonal relationships, peer learning and peer critique, as well as an expectation that members will take care of each other.
Development of catalytically active and highly stable catalyst supports for polymer electrolyte membrane fuel cells

Abstract Novel procedures are developed for the synthesis of highly stable carbon composite catalyst supports (CCCS-800 °C and CCCS-1100 °C) and an activated carbon composite catalyst support (A-CCCS). These supports are synthesized through: (i) surface modification with acids and inclusion of oxygen groups, (ii) metal-catalyzed pyrolysis, and (iii) chemical leaching to remove excess metal used to dope the support. The procedure results in increasing carbon graphitization and inclusion of non-metallic active sites on the support surface. Catalytic activity of CCCS indicates an onset potential of 0.86 V for the oxygen reduction reaction (ORR) with well-defined kinetic and mass-transfer regions and ∼2.5% H2O2 production in rotating ring disk electrode (RRDE) studies. Support stability studies at 1.2 V constant potential holding for 400 h indicate high stability for the 30% Pt/A-CCCS catalyst with a cell potential loss of 27 mV at 800 mA cm−2 under H2-air, 32% mass activity loss, and 30% ECSA loss. Performance evaluation in polymer electrolyte membrane (PEM) fuel cell shows power densities (rated) of 0.18 and 0.23 gPt kW−1 for the 30% Pt/A-CCCS and 30% Pt/CCCS-800 °C catalysts, respectively. The stabilities of various supports developed in this study are compared with those of a commercial Pt/C catalyst.
Effect of the thermal treatment of ionomer films on permeability and permselectivity

Ionomers have been studied in detail and have gained widespread commercial use. Interested in altering the ratio of CO2/O2 permeability (i.e., permselectivity) of films for use in packaging respiring produce, we pressed sodium-neutralized poly(ethylene methacrylic acid) ionomers into films at 120–160°C and investigated their thermal, morphological, and permeability properties. The heat treatment of the ionomers at 160°C increased the gas permeability for O2 more than for CO2 and reduced the CO2/O2 permselectivity ratio from 4.1 to 1.6. The reasons for these changes in the permeability characteristics of the ionomers are not understood but could be related to a reduction in the polyethylene (PE) crystallinity and the destruction of the aggregates into smaller, dispersed clusters. These results were supported by differential scanning calorimetry data and scanning electron micrographs. This suggests that the heat treatment of ethylene–methacyrlic ionomers may improve their potential for applications as selective barriers for modified-atmosphere packaging of respiring produce. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2811–2815, 2002
Differential scanning tunnelling microscopy

SUMMARY We review the principle of differential imaging and its application to scanning tunnelling microscopy (STM). It is shown that placing a lateral dither on an STM tip at high frequency provides the means for transfering topographic information to a frequency range where noise is small. Differential STM imaging on graphite and gold is demonstrated. A simple relation between the differential image and the conventional topographic image is described.
Investigator Attitudes towards Participation in Contract Research Organization-Managed Clinical Studies

Background: Studies managed by contract research organizations (CROs) make up a significant portion of all clinical research activities. Despite this, there have been few analyses of investigator attitudes about the type of organization (i.e. CRO or sponsor company) that directly manages the investigator’s clinical trial. Methods:Utilizing a random sample of 5000 US investigators from the US Food and Drug Administration (FDA) 1572 database, the University of the Sciences in Philadelphia and TTC llc conducted a questionnairebased mail survey. Results:A total of 762 US investigators responded to the questionnaire. Investigators returning a completed questionnaire were more likely to come from an academic medical centre, be involved in teaching or be located at a research centre than non-respondents. They also had more 1572 records on file with the FDA, were older, but did not differ by sex. Nearly one-third of investigators preferred working directly with sponsor companies; two-thirds had no preference or actually preferred a CRO. These three types of investigators differed little in their reasons for participating in clinical trials. Each group cited the opportunity to participate in the research of innovative medical treatments as their primary motivation. Conclusions: Older investigators with more research experience do somewhat prefer a sponsor company to manage the clinical trial, although this group participates in a high percentage of CRO-managed studies.