cssi/SciSciGPT-SciSciNet huggingface dataset:
Scale and Translation Invariant Methods for Enhanced Time-FrequencyPattern Recognition

Time-frequency (t-f) analysis has clearly reached a certain maturity. One can now often provide striking visual representations of the joint time-frequency energy representation of signals. However, it has been difficult to take advantage of this rich source of information concerning the signal, especially for multidimensional signals. Properly constructed time-frequency distributions enjoy many desirable properties. Attempts to incorporate t-f analysis results into pattern recognition schemes have not been notably successful to date. Aided by Cohen‘s scale transform one may construct representations from the t-f results which are highly useful in pattern classification. Such methods can produce two dimensional representations which are invariant to time-shift, frequency-shift and scale changes. In addition, two dimensional objects such as images can be represented in a like manner in a four dimensional form. Even so, remaining extraneous variations often defeat the pattern classification approach. This paper presents a method based on noise subspace concepts. The noise subspace enhancement allows one to separate the desired invariant forms from extraneous variations, yielding much improved classification results. Examples from sound classification are discussed.
Phase-locked loop based delta-sigma ADC

A phase-locked loop (PLL) based delta-sigma analogue-to-digital converter architecture providing second-order noise shaping is presented. By combining a low power passive integrator with a voltage-controlled oscillator-based integrator, the proposed architecture suppresses the oscillator nonlinearity with minimum hardware penalty. Simulation results indicate 14-bit performance by using only a 4-bit linear oscillator.
Recent Developments in the Theory of Electron Scattering by Highly Polar Molecules

Publisher Summary This chapter summarizes recent work in the theory of electron collisions as applied to highly polar molecules. In the discussion of both theory and calculations presented in the chapter, the emphasis is on elastic scattering and rotational excitation; however, vibrational excitation is also discussed briefly. The chapter presents a general overview of the unique features of scattering by polar molecules with a view to motivating and providing direction for the discussion to follow. The chapter is also devoted to a synthesis of the formal theoretical hardware, to numerical techniques that are essential to scattering calculations, and to an adequate description of the interaction potential. The chapter emphasizes on the approaches that employ the most powerful and general techniques. Discussions and comparisons of some of the recent applications of this machinery, the various approximations made thereto, and the general physical picture thus developed are presented in the chapter.
Web 2.0 and warfighter training

Web 2.0 services refer to web-based applications that allow a user to create and publish their own unique content. They also include services that allow mass collaboration among self-organized communities. Tim O'Reilly defines Web 2.0 as any set of tools that are able to harness the collective intelligence of groups of people and put that to work toward a shared goal. These services focus on distributed collaboration, information sharing, interoperability, and information reuse -- many of the same issues that military simulation projects face.Simulation-based training has always wrestled with issues in user interfaces, collaboration, networking, standardization, and interoperability. These problems have often been more advanced than those faced in the business IT and C4I communities. As a result we have developed a culture in which we develop our own software, hardware, and networking solutions. However, recent advances in fields like computer gaming and business IT have shown that commercial technologies can become the basis for simulation systems. Over the last two years consumer IT applications have emerged that may have useful application in distributed simulation. Social networks, wikis, blogs, web page tagging, photo and video sharing, and tools for personal 3D game development have all attracted significant attention in the commercial world by bringing distributed processing technologies to the mass consumer.Web 2.0 companies are creating tools which answer important problems around distributed, interoperable, interactive, user centered experiences. This paper identifies many of these applications, defines useful categories for understanding them, and illustrates valuable applications in simulation and training. Just as computer games brought powerful commercial technologies to military training, Web 2.0 applications have similar potential which is not yet generally recognized. The goal of this paper is to begin a dialog on the useful application of these technologies within the interactive simulation community.
Magnetic neutron-scattering study of MnCl 2 -graphite intercalation compound

The in-plane spin order of ${\mathrm{MnCl}}_{2}$ graphite intercalation compound has been studied between 63 mK and 30 K by elastic neutron scattering. This compound approximates a classical XY antiferromagnet on a triangular lattice. Below 7.5 K magnetic critical scattering peaks are observed at wave vectors incommensurate with the ${\mathrm{MnCl}}_{2}$ and graphene sublattices. As the temperature is raised, the cell contracts towards a commensurate 2$\sqrt{3}$\ifmmode\times\else\texttimes\fi{}2$\sqrt{3}$ magnetic unit cell. The ground-state in-plane spin configuration is explained by an exchange Hamiltonian that includes no fewer than three shells of nearest neighbors in the plane. The magnetic peaks have a Lorentzian shape and are broader than resolution down to 63 mK, well below the peak in the magnetic susceptibility at 1.1 K. No evidence of three-dimensional magnetic correlations was found at any temperature.
Re–Os isotope evidence for the composition, formation and age of the lower continental crust

Knowledge of the composition of the lower continental crust is important for understanding the formation and evolution of the crust as a whole, and the petrogenesis of continental basalts. Here we present rhenium–osmium isotope data for two well characterized suites of lower-crustal xenoliths from North Queensland, Australia1,2,3,4,5,6,7, which have average major- and trace-element compositions similar to estimates of the bulk lower continental crust8,9. Our data indicate that the lower crust has 1 to 2 times as much osmium, about half as much rhenium, and is less radiogenic than the upper continental crust10. We interpret the rhenium–osmium isotope systematics to indicate that assimilation and fractional crystallization are important processes in the formation of the lower crust, and lead to dramatic changes in the osmium isotopic composition of basalts that pond and fractionate there. A consequence of this is that the rhenium–osmium isotopic system should not be relied on to yield accurate mantle extraction ages for continental rocks.
Regulated Expression and Subcellular Localization of Syndecan Heparan Sulfate Proteoglycans and the Syndecan-Binding Protein CASK/LIN-2 during Rat Brain Development

The syndecan family of cell surface heparan sulfate proteoglycans interacts via their cytoplasmic C-terminal tail with the PDZ domain of CASK/LIN-2, a membrane-associated guanylate kinase homolog. The syndecan–CASK interaction may be involved in intercellular signaling and/or cell adhesion. Here we show that syndecan-1 to syndecan-4 have distinctive mRNA distributions in adult rat brain by in situ hybridization, with syndecan-2 and -3 being the major syndecans expressed in neurons of the forebrain. At the protein level, syndecan-2 and -3 are differentially localized within neurons; syndecan-3 is concentrated in axons, whereas syndecan-2 is localized in synapses. The synaptic accumulation of syndecan-2 occurs late in synapse development. CASK is a cytoplasmic-binding partner for syndecans, and its subcellular distribution changes strikingly during development, shifting from a primarily axonal distribution in the first 2 postnatal weeks to a somatodendritic distribution in adult brain. This change in CASK distribution correlates temporally and spatially with the expression patterns of syndecan-3 and -2, consistent with the association of both of these syndecans with CASK in vivo . In support of this, we were able to coimmunoprecipitate a complex of CASK and syndecan-3 from brain extracts. Our results indicate that specific syndecans are differentially expressed in various cell types of the brain and are targeted to distinct subcellular compartments in neurons, where they may serve specialized functions. Moreover, CASK is appropriately expressed and localized to interact with both syndecan-2 and -3 in different compartments of the neuron throughout postnatal development.
CHANGES IN LIFE EXPECTANCY IN THE UNITED STATES DUE TO DECLINES IN MORTALITY, 1968–1975

This study examines the gains in life expectancy for four race/sex groups of the US population between 1968 and 1975. An increase of 2.3 years in life expectancy at birth and 1.7 years in life expectancy at age 45 years has occurred for all race/sex groups combined. The added years of life for the normal working ages (15-70 years) is only 0.6 years for the total US population, 0.3 years for white females, 0.6 years for white males, 1.5 years for nonwhite males, and 1.7 years for nonwhite females. The relative contribution of the five leading causes of death to this gain varies at different ages. For example, more than 50% of the increase in life expectancy at age 45 years was due to a lower mortality rate in diseases of the heart which is still the leading cause of death among each of the race/sex groups. Other contributions to the increase in life expectancy at age 45 years are: cerebrovascular diseases, 16%; accidents, 6%; influenza and pneumonia, 7%; and all other causes, 16%. The increase in the malignant neoplasms mortality rate had a negative effect, -2%, on the gain of life expectancy.
Crooksidine, an indole alkaloid from Haplophyton crooksii

Abstract Crooksiine, a new bisindole alkaloid with antiacetylcholinesterase activity was isolated from Haplophyton crooksii . Its structure was established utilizing spectrometric methods.
Lysosomes and disease

The cells of most vertebrate tissues possess specialized structures called lysosomes.These organelles contain enzymes which can digest proteins, carbohydrates, and other cell constituents. Lysosomes appear to play a vital role in the life and death of cells. They have been linked to important physiological processes and to the pathogenesis of a variety of human diseases.
Caloric Restriction Alters the Metabolic Response to a Mixed-Meal: Results from a Randomized, Controlled Trial

Objectives: To determine if caloric restriction (CR) would cause changes in plasma metabolic intermediates in response to a mixed meal, suggestive of changes in the capacity to adapt fuel oxidation to fuel availability or metabolic flexibility, and to determine how any such changes relate to insulin sensitivity (SI). Methods: Forty-six volunteers were randomized to a weight maintenance diet (Control), 25% CR, or 12.5% CR plus 12.5% energy deficit from structured aerobic exercise (CR+EX), or a liquid calorie diet (890 kcal/d until 15% reduction in body weight)for six months. Fasting and postprandial plasma samples were obtained at baseline, three, and six months. A targeted mass spectrometry-based platform was used to measure concentrations of individual free fatty acids (FFA), amino acids (AA), and acylcarnitines (AC). SI was measured with an intravenous glucose tolerance test. Results: Over three and six months, there were significantly larger differences in fasting-to-postprandial (FPP) concentrations of medium and long chain AC (byproducts of FA oxidation) in the CR relative to Control and a tendency for the same in CR+EX (CR-3 month P=0.02; CR-6 month P=0.002; CR+EX-3 month P=0.09; CR+EX-6 month P=0.08). After three months of CR, there was a trend towards a larger difference in FPP FFA concentrations (P=0.07; CR-3 month P=0.08). Time-varying differences in FPP concentrations of AC and AA were independently related to time-varying SI (P,0.05 for both). Conclusions: Based on changes in intermediates of FA oxidation following a food challenge, CR imparted improvements in metabolic flexibility that correlated with improvements in SI. Trial Registration: ClinicalTrials.gov NCT00099151
A differential absorption spectrometer for determining flash X-ray spectra☆

Abstract Three models of a differential absorption spectrometer have been developed for determining the photon spectra of bremsstrahlung sources whose endpoints vary from ∼ 150 to 2000 keV. Spectral data are unfolded from dose-depth measurements using an iterative technique, with spectral response functions generated by a radiation transport code (CEPXS/ONETRAN). Unfolded spectra from quasi-monoenergetic photon sources from 17 to 1250 keV, and from a well-characterized continuous bremsstrahlung source at endpoint energies from 150 to 900 keV, were in good agreement with the known or calculated spectra. The use of the DAS to estimate the spectra from flash X-ray sources is demonstrated. The effects of systematic and random errors on unfolded spectra are evaluated.
Reducing energy consumption of queries in memory-resident database systems

The tremendous growth of system memories has increased the capacities and capabilities of memory-resident embedded databases, yet current embedded databases need to be tuned in order to take advantage of new memory technologies. In this paper, we study the implications of hosting memory resident databases, and propose hardware and software (query-driven) techniques to improve their performance and energy consumption. We exploit the structured organization of memories, which enables a selective mode of operation in which banks are accessed selectively. Unused banks are placed in a lower power mode based on access pattern information. We propose hardware techniques that dynamically control the memory by making the system adapt to the access patterns that arise from queries. We also propose a software (query-directed) scheme that directly modifies the queries to reduce the energy consumption by ensuring uniform bank accesses. Our results show that these optimizations could lead to at the least 40% reduction in memory energy. We also show that query-directed schemes better utilize the low-power modes, achieving up to 68% improvement.
Phenotypic and functional characterization of the hematopoietic stem cell

ABSTRACT The purpose of this report is to demon- strate the phenotypic and functional charac- teristics of a primitive hematopoietic stem cell (HSC). We present evidence that an isolated murine HSC can repopulate the hematopoietic tissues of lethally irradiated recipient animals long term. By limiting dilution, as few as ten isolated stem cells can reconstitute mice for their lifetime. The stem cell which we have iso- lated does not copurify with colony forming unit-spleen or radioprotect recipients from lethal radiation. The phenotypic characteri- zation of this rare cell, which represents 0.005% of total bone marrow, includes either the absence or very low expression of mark- ers associated with long-term repopulating cells described by other groups. We believe this stem cell represents a very early self- renewing stem cell in the mouse. Stem Cells 1997;15(~~p~~E 1):41-45 INTRODUCTION The functional definition of a hematopoietic stem cell (HSC) includes the ability of this cell to repopulate the hematopoietic tissues of transplanted recipients long term as well as maintain itself (self-renewal.) Self- renewal is defined as the ability of the HSC to give rise to additional stem cells; this is tested by subjecting this cell to secondary transplantation. Techniques utilized by us [l] and others [2] have led to the isolation of HSC by collecting small-sized cells by elutriation, suggesting that these cells are not in cycle. These HSC repopulate the hematopoietic system of lethally irradiated hosts. Other investigators [3-51 have also published data supporting the isolation of candidate HSC. Several groups
Partial regularity for weak heat flows into riemannian homogeneous spaces

It is proved that any weak flow of harmonic maps into a compact homogeneous manifold satisfying the monotonicity inequality and the energy inequality is regular off a closed set of m-dimensional Hausdorff measure zero (w.r.t parabolic metric), and coincides with a regular flow if the latter one exists. Moreover, it is also shown that the weak limit of a sequence of such weak flows is a weak flow.
Extracting target orientation for different electromagnetic induction sensing geometries

Electromagnetic induction (EMI) sensors are commonly used to detect and locate buried metallic objects such as landmines, but they are capable of extracting much more information about objects, e.g., location and magnetic polarizability. Recent research has led to an effective inversion method to extract target orientation by finding the tensor representation of the target [1-3]. The “tensor amplitude” extraction techniques also have an important capability that has not been fully examined until now, and that is the ease with which they can be used with a variety of EMI sensor geometries. This paper will examine how making slight alterations to an existing sensor geometry can dramatically increase its effectiveness, while still using the “tensor amplitude” extraction to accurately and efficiently determine the unknown parameters of a metallic object.
Comparison of active and passive environmental sampling for safeguards applications

Environmental sampling (ES) of surfaces using cotton swipes at nuclear facilities is one of the standard sampling protocols used by International Atomic Energy Agency (IAEA) inspectors to verify treaty compliance. Described herein is a series of studies undertaken to (1) survey a variety of low latent uranium content sampling media for efficacy of collecting nuclear materials and (2) compare active collection of particulates to swipe sampling. Findings from the evaluation of 40 natural and synthetic woven swipes will be presented. Results from a joint Oak Ridge National Laboratory (ORNL) and Savannah River National Laboratory (SRNL) project wherein a variety of passive deposition surfaces and active collections were examined for efficacy of sampling uranium processing effluents will also be detailed. For the swipe material evaluation portion of this work, uranium (U) particulate collection efficiency was evaluated on woven materials as-received and coated with complexants/solvents. The relative merits of each sampling matrix were reviewed on the basis of: (1) latent U background, (2) ease of separating the swipe material from the nuclear components, (3) presence of isobaric interferences from the swipe, and (4) efficiency in collecting uranium from contaminated surfaces. The second series of experiments evaluated the collection characteristics of active aerosol collection versus swipe sampling. ORNL and SRNL are collaborating on the development of the next generation of ES equipment for air grab and constant samples that could become an important addition to the international nuclear safeguards inspector’s toolkit. Described herein are findings from the evaluation of collection efficiency of swipe sampling and active collection using an aerosol contaminant extractor (ACE) developed by SRNL.
Evidence-based Integrative Medicine in Clinical Veterinary Oncology

Integrative medicine is the combined use of complementary and alternative medicine with conventional or traditional Western medicine systems. The demand for integrative veterinary medicine is growing, but evidence-based research on its efficacy is limited. In veterinary clinical oncology, such research could be translated to human medicine, because veterinary patients with spontaneous tumors are valuable translational models for human cancers. An overview of specific herbs, botanics, dietary supplements, and acupuncture evaluated in dogs, in vitro canine cells, and other relevant species both in vivo and in vitro is presented for their potential use as integrative therapies in veterinary clinical oncology.
Cytoplasmic Polyamines as Permeant Blockers and Modulators of the Voltage-Gated Sodium Channel

We report that voltage-gated Na+ channels (Na(V)) from rat muscle (mu1) expressed in HEK293 cells exhibit anomalous rectification of whole-cell outward current under conditions of symmetrical Na+. This behavior gradually fades with time after membrane break-in, as if a diffusible blocking substance in the cytoplasm is slowly diluted by the pipette solution. The degree of such block and rectification is markedly altered by various mutations of the conserved Lys(III) residue in Domain III of the Na(V) channel selectivity filter (DEKA locus), a principal determinant of inorganic ion selectivity and organic cation permeation. Using whole-cell and macropatch recording techniques, we show that two ubiquitous polyamines, spermine and spermidine, are potent voltage-dependent cytoplasmic blockers of mu1 Na(V) current that exhibit relief of block at high positive voltage, a phenomenon that is also enhanced by certain mutations of the Lys(III) residue. In addition, we find that polyamines alter the apparent rate of macroscopic inactivation and exhibit a use-dependent blocking phenomenon reminiscent of the action of local anesthetics. In the presence of a physiological Na+/K+ gradient, spermine also inhibits inward Na(V) current and shifts the voltage dependence of activation and inactivation. Similarities between the endogenous blocking phenomenon observed in whole cells and polyamine block characterized in excised patches suggest that polyamines or related metabolites may function as endogenous modulators of Na(V) channel activity.
Effects of Established Perennial Grasses on Introduction of Native Forbs in California

Prairie restoration is not complete without the establishment of both grasses and forbs. However, if desirable forbs and grasses are seeded simultaneously, control of broadleaf weeds is problematic. If possible, a two-step process of introducing forbs after establishing grasses would allow use of broadleaf-specific herbicides at the critical early stages of grass growth. We conducted experiments to investigate methods for introducing forbs into previously restored native perennial grasslands on rural roadsides in the Sacramento Valley of California. In one experiment, we studied the effects of background vegetation (established perennial grasses or tilled ground) on seven native forb species planted from seed. In a second experiment, we evaluated the effects of background vegetation (existing perennial grasses or tilled ground) and container size (36 ml or 105 ml) with excavation technique (excavation by core removal [core] or by creating an impression [dibble]) on the growth of transplants of the native perennial forbs Asclepias fascicularis and Sisyrinchium bellum . The presence of established perennial grasses reduced the growth of seeded forbs, but did not affect transplants, indicating the vulnerability of seedling forbs to interference. When compared to control plots that had been tilled in the autumn, weed canopy cover was significantly lower in the presence of perennial grasses if seeded with forbs, but not in the presence of perennial grasses alone. Both transplanted species grew better in the large container/core treatment than the small container/ dibble treatment; however, existing grasses eliminated these positive effects. Asclepias fascicularis performed better when grown in large containers than in small containers, but its growth was not affected by excavation method; S. bellum performed better when planted with the core method than the dibble method of excavation, but container size made no difference. We attribute differences in the responses of the species to interactions between phenological differences and expansive clay soils that naturally de-compact upon drying.
The gcvB gene encodes a small untranslated RNA involved in expression of the dipeptide and oligopeptide transport systems in Escherichia coli

The Escherichia coli gcvB gene encodes a small RNA transcript that is not translated in vivo. Transcription from the gcvB promoter is activated by the GcvA protein and repressed by the GcvR protein, the transcriptional regulators of the gcvTHP operon encoding the enzymes of the glycine cleavage system. A strain carrying a chromosomal deletion of gcvB exhibits normal regulation of gcvTHP expression and glycine cleavage enzyme activity. However, this mutant has high constitutive synthesis of OppA and DppA, the periplasmic-binding protein components of the two major peptide transport systems normally repressed in cells growing in rich medium. The altered regulation of oppA and dppA was also demonstrated using oppA–phoA and dppA–lacZ gene fusions. Although the mechanism(s) involving gcvB in the repression of these two genes is not known, oppA regulation appears to be at the translational level, whereas dppA regulation occurs at the mRNA level.
Global agricultural drought mapping: Results for the year 2011

Food production and security will become more and more important issue as the world population has been steadily increasing since 1960. In contrast, the volume of crop production hasn't been keeping up with human population's uptrend. Major fall in crop production is a typical result of recurring agricultural droughts. To be able to predict such crop failures, a drought monitoring system at global scale is required. For this reason, a new project named Global Agricultural Drought Monitoring and Forecasting System (GADMFS) kicked off earlier in 2011. Our drought maps indicated multiple agricultural droughts in varying severities across the globe such as persistent extreme drought in Texas, US and short-term drought around Western Europe enclosing Germany, Luxembourg and France. The results from other sources such as US Drought Monitor (USDM) and European commission Joint Research Center Institute (JRC) for Environment and Sustainability (IES) confirmed our findings. In conclusion, accurate satellite vegetation indices are invaluable source for drought monitoring applications.
Marking Time: The Effect of Timing on Appointment Keeping

The retrospective memory literature suggests that people develop internal representations of time based on the stable occurrence of events in time. Two experiments were conducted to investigate whether the temporal structure of daily life affects prospective remembering. Fifty-six subjects in Experiment 1 were randomly assigned to an appointment time scheduled either during the ‘work’ week (assumed to be more routine-filled or structured) or the weekend (assumed to be less structured). Results, while non-significant, indicated that the number of reminders may have mediated performance. There was an attempt to control this in Experiment 2. The results indicate that appointments imbedded within more structured days are more easily recalled. © 1997 John Wiley & Sons, Ltd.
Teaching globalization, globally: A 7-year case study of south africa--u.s. virtual teams

This article reports on a project conducted from 1999--2006 that involved a substantial collaboration between South African and U.S. universities to build human capacity for the knowledge-intensive global economy through geographically distributed collaborative learning. The project used a highly interactive, rich media, synchronous and asynchronous learning environment to foster U.S.--South Africa student team learning. Particular attention was paid to the use of commercially available Web-based collaboration technologies that work well in both developed and developing country university settings. The study had one overarching research question: Can universities in developing as well as developed countries use a suite of commercially available Web-based collaboration technologies to successfully deliver an advanced global graduate seminar? Data for the study came from narrative evaluations and post-hoc surveys of student participants. Focusing on providing a model that can be used in disparate multidisciplinary and university settings, the article highlights both the technologies and the pedagogy that recognize cultural differences and cross-national collaborative opportunities in university settings.
Broadly reactive human CD8 T cells that recognize an epitope conserved between VZV, HSV and EBV.

Human herpesviruses are important causes of potentially severe chronic infections for which T cells are believed to be necessary for control. In order to examine the role of virus-specific CD8 T cells against Varicella Zoster Virus (VZV), we generated a comprehensive panel of potential epitopes predicted in silico and screened for T cell responses in healthy VZV seropositive donors. We identified a dominant HLA-A*0201-restricted epitope in the VZV ribonucleotide reductase subunit 2 and used a tetramer to analyze the phenotype and function of epitope-specific CD8 T cells. Interestingly, CD8 T cells responding to this VZV epitope also recognized homologous epitopes, not only in the other α-herpesviruses, HSV-1 and HSV-2, but also the γ-herpesvirus, EBV. Responses against these epitopes did not depend on previous infection with the originating virus, thus indicating the cross-reactive nature of this T cell population. Between individuals, the cells demonstrated marked phenotypic heterogeneity. This was associated with differences in functional capacity related to increased inhibitory receptor expression (including PD-1) along with decreased expression of co-stimulatory molecules that potentially reflected their stimulation history. Vaccination with the live attenuated Zostavax vaccine did not efficiently stimulate a proliferative response in this epitope-specific population. Thus, we identified a human CD8 T cell epitope that is conserved in four clinically important herpesviruses but that was poorly boosted by the current adult VZV vaccine. We discuss the concept of a “pan-herpesvirus” vaccine that this discovery raises and the hurdles that may need to be overcome in order to achieve this.
AN ESHELBY-TYPE APPROACH FOR DEFECT ENERGETICS IN CARBON NANOTUBES

This paper presents a method for characterizing the formation energy of Stone‐Wales defect transformation in deforming carbon nanotubes. A formula is derived to show that the structural energy variation consists of the change of atomic potential due to bond reconfiguration in a local defective region, and an elastic correction that represents the influence of the remaining system. The advantage of the method lies in its computational efficiency. Specifically, global optimization for the configuration of the defective tube is eliminated. We use the method to investigate the formation energy distribution in nonuniformly deforming nanotubes, and to study the energetic interaction between multiple defects. Accuracy of the method is also assessed through numerical experiments.
International Students' Motivation to Pursue and Complete a Ph.D. in the U.S.

This study explores what motivates 19 international students to pursue a Ph.D. at a public research university in the U.S. and, more importantly, what motivates them to persist despite unsatisfying socialization. Based on value-expectancy achievement motivation theory, four motivations emerged: intrinsic interest in research, intrinsic interest in teaching, high utility of a U.S.-earned Ph.D., and high emotional and social cost of quitting. As students’ educational experiences unfolded, the influence of these motivations changed over time. Findings and implications are discussed in connection with the achievement motivation theory and the literature on international student mobility. Implication for future research is also provided.
Decomposition of fMRI data into multiple components

The goal of this work is to provide a new representation of functional magnetic resonance imaging (fMRI) time series. Functional neuroimaging aims at quantifying and localizing neuronal activity using imaging techniques. Functional MRI can detect and quantify hemodynamic changes induced by brain activation and neuronal activity. The time course of the fMRI signal at a given voxel inside the brain is represented with a structural model where each component of the model belongs to a subspace spanned by a small number of basis functions. The basis functions in different subspaces have very distinct time-frequency characteristics. The large scale trend of the signal is represented with a combination of large scale wavelets. The response to the stimulus is expanded on a small set of basis functions. Because it is critical to adapt the basis functions to the type of stimulus, the evoked response to a random presentation is expanded into small scale wavelets or wavelet packets, while the response to a periodic stimulus is represented with cosine or sine functions. We illustrate the estimation of the components of the model with several experiments.
Siderophore-promoted dissolution of hematite

Siderophores are highly Fe( III)-specific bidentate ligands excreted by aerobic and facultative anaerobic microorganisms to facilitate Fe uptake in oxic environments. These compounds are thought to influence mineral weathering and the biogeochemical cycling of Fe, but quantitative information concerning this possible influence is nonexistent. Preparative quantities of a soil bacterium siderophore were extracted and purified for use in batch dissolution experiments performed with synthetic hematite particles suspended in 1 mmol dm−3 NaNO3 at pH 3 under exclusion of light. The initial siderophore concentration used, 0.24 mmol dm−3 was representative of microniche environments. Soluble Fe per unit mass of hematite was linear with time over an observational period between 2 and 24 h, leading to an area-based dissolution rate of 10−8 mol m−2 h−1 . Comparative dissolution experiments, performed with oxalate and ascorbate ligands at the 2–3 mmol dm−3 initial concentration typical of soil environments (otherwise identical conditions to the siderophore experiments), led to dissolution rates of 5 X 10−8 mol m−2 h−1 , in agreement with literature values. The comparability of dissolution rates for a soil bacterium siderophore and two terrestrial organic ligands, despite an order-of-magnitude difference in their initial concentrations, suggests that siderophores may indeed figure significantly in Fe(Ill) -mineral weathering reactions under natural conditions.
Effect of lubricant on helicopter transmission efficiency

Efficiency tests were conducted using eleven different lubricants in the NASA Lewis Research Center's 500 hp torque regenerative helicopter transmission test stand. The test transmission was the OH58A helicopter main transmission. The mechanical power input to the test transmission was 224 kW (300 hp) at 6060 r/min. Tests were run at oil-in temperatures of 335°K (180°F) and 372°K (210°F). The efficiency was calculated from a heat balance on the water running through an oil-to-water heat exchanger while the transmission was heavily insulated. The test lubricants were analysed for their physical and chemical properties. Data on pressure-viscosity characteristics as well as friction data from LFW-1 type testing were examined for possible correlation with the efficiency data. The following results were obtained. (1) Among the eleven different lubricants, the efficiency ranged from 98.3 to 98.8%, which is a 50% variation relative to the losses associated with the maximum efficiency measured. (2) for a given lubricant, the efficiency increased as temperature increased and thus as viscosity decreased. There were two exceptions which could not be explained on the basis of available data. (3) There was a reasonable correlation of efficiency with absolute viscosity (corrected for temperature and pressure in the contact). (4) Between lubricants, efficiency did not correlate well with absolute viscosity at atmospheric pressure. (5) Between lubricants, efficiency did not correlate well with calculated lubricant film forming capacity. (6) Bench type (LFW-1) sliding friction and wear measurements could not be correlated to transmission efficiency and component wear. (7) The lubricants had no significant effect on the vibration signature of the transmission.
Inflation, Portfolio Choice, and the Prices of Land and Corporate Stock: Discussion

The paper by Martin Feldstein presents a novel approach to asset pricing over time. It departs from the present value and discounted rate-of-return models familiar to most agricultural economists. By introducing differential tax rates, portfolio balance concepts, and uncertainty, it highlights demand-side forces which affect relative prices of land and other assets in the presence of general price inflation.
Multi-asset control, sensor fusion, and information sharing through a centralized operator station

As the number of sensing assets and tactical command and control (C2) systems grow, the need for a centralized means of collecting and disseminating the crucial information grows as well. Over the past 5 years, Honeywell has created a software application known as the Network-Enabled Operator Station (NEOS) to answer this need. NEOS has been developed from the ground up to be an open-architecture solution which integrates a variety of assets, communications systems and protocols, and data sharing techniques. The ultimate goals are to increase friendly situational awareness and increase the effectiveness of field operators.
A Framework for Optimizing Resource Allocation for Health Education Programs

Health education programs conventionally are implemented in four sites: school, clinical, occupational, and community settings. One problem encountered by health education specialists, community health planners, and policy makers, is ascertaining the optimal allocation of health education resources to these four settings. This paper proposes a framework to assist in making this decision. The framework incorporates considerations of the target group, the health problem, the desired health behaviors, and administrative aspects of the program, which are broken down into 26 different "criteria", (e.g., age of target group, stage of disease intervention). Each of the 26 criteria has its respective "dimensions" (e.g., age of target group: preschool children, school children, and adults), and each dimension in turn suggests the optimal health education setting(s). An improved understanding of the advantages and disadvantages of implementing health education programs in the different sites will facilitate better coordination between practitioners in school, clinical, occupational, and community settings.
Quantitative effect of a single large dose of methylprednisolone on infarct size in baboons.

Despite numerous studies directed at determining the ability of glucocorticoids to minimise myocardial ischaemic damage following acute coronary occlusion, there remains no clear consensus concerning their usefulness. Within an ischaemic region, glucocorticoids produce membrane stabilising effects which decrease the autolytic effects of marked cellular swelling and lysosomal membrane rupture.1-3 Their use has also been associated with a decreased cellular lysis due to infiltrating inflammatory cells1 and with an increase in collateral blood flow.4 The use of glucocorticoids has remained clinically attractive due to experimental observations regarding these local actions; however, the potential of these actions to enhance long-term viability of ischaemic myocardium has remained uncertain. A major problem in the comparison of the extent of infarction between treated and untreated animals has been the variability in infarct size that results from coronary artery ligation at any given anatomical site.2 5 6 In the experimental baboon model which we have employed, we have previously shown that the ultimate epicardial area of infarction, as well as the volume of infarction as assessed histologically at 7 days post occlusion, shows a good linear relationship to the area of ischaemic injury at 1-hour post occlusion, as assessed by high resolution epicardial ST segment mapping.7 In this way animals may serve as their own controls and as long as an intervention is initiated at 1 h or later post occlusion, then the epicardial area or transmural volume of histologically assessed infarction at 7 days can be compared with the predicted epicardial area or transmural volume of infarction and hence determine the effect of that intervention in altering infarct size. This experimental model does not rely on a comparison of the absolute magnitude of infarcts between treated and untreated animals and, therefore, avoids the error introduced by the inherent variability in infarct size between animals after coronary occlusion.
Hypotension and thirst in rats after phentolamine treatment

Abstract Administration of the α-adrenergic receptor blocker phentolamine is known to lower arterial blood pressure and to increase renin secretion and water intake in rats. In the present experiments, drinking by rats after subcutaneous administration of the drug was found to be inversely related to arterial blood pressure within the range of 60–90 mm Hg. Drug treatment in nephrectomized rats led to such severe hypotension that drinking was precluded. Pretreatment with propranolol moderated the hypotension in nephrectomized rats and drinking was not attenuated. These results parallel those of previous experiments using the β-adrenergic receptor agonist isoproterenol. Collectively, they suggest that after treatment with these hypotensive agents, a stimulus for thirst can arise from some factor other than angiotensin. This stimulus, perhaps mediated by arterial baroreceptors, is additive in its effects on thirst with the stimulus induced by hypertonic NaCl or subcutaneous colloid treatments.
3D simulation of GaAs/AlGaAs quantum dot point contact structures

We present simulation results for the activation barrier O 0 and the number of electrons N in a quantum dot structure that are obtained from the self-consistent solution of the 3D Schrodinger-Poisson problem. We observe an approximately linear rise in the electrostatic barrier O 0 as a function of the gate bias once pinchoff occurs. There is an associated linear decrease in the number of the electrons in the dot region. Calculated values of O 0 and N are in an agreement with those utilized in the energy balance analysis for similar structure investigated experimentally in connection with negative conductance behaviour. The simulation results also suggest that, if the dot area is too small, all particles may be depleted from the dot before the input and output barrier forms, thus preventing the bistable operation.
Circular Substrates of the Hammerhead Ribozyme Shift the Internal Equilibrium Further toward Cleavage

To test whether the Y-shaped conformation of the hammerhead ribozyme is maintained throughout the catalytic pathway, the cleavage properties of circular substrates which bind the ribozyme through helices I and II were determined. Constraining the position of helices I and II in this manner did not significantly alter the rate constant for cleavage, consistent with no large rearrangement of the helices occurring during catalysis. Unexpectedly, the “internal” equilibrium between the cleavage and ligation reactions for the circular hammerheads was shifted further toward cleavage. This effect was due to the rate of ligation of the circular substrate being slower than the corresponding linear substrate. The temperature dependence of the internal equilibrium of the circular substrate revealed that although restricting the flexibility of the hammerhead reduced the favorable entropy change associated with cleavage as expected, the unfavorable enthalpy change was reduced as well, resulting in greater overall cleavage.
Time-series ingestion rate estimates on individual Calanus pacificus Brodsky: interactions with environmental and biological factors

Time-series of estimates of ingestion rate were obtained for individual Calanus pacificus Brodsky adult females provided with excess food. In one set of experiments copepods were incubated in the dark and estimates were made every 1.5 h over a 12-h period. In two additional sets of experiments estimates were made every 6 h over a 48-h period with copepods kept either in continuous darkness or in a simulated 12-h light:dark cycle. The results indicate that: (1) ingestion rate was higher in starved females than in unstarved females, (2) ingestion rate was higher in the dark than in the light, (3) gut phaeopigment and egg production, determined at the end of the experiments, were correlated with ingestion rate, and (4) egg production and ingestion rate were correlated with body size. However, stepwise multiple linear regression analysis indicated that the apparent relationship between egg production and ingestion rate may have been due to the intercorrelation of egg production, ingestion rate, and body size. No significant endogenous rhythmic feeding was found.
Digital image correlation techniques for full-field displacement measurements of micro air vehicle flapping wings

This work has detailed a novel method for capturing the motion of a rapidly actuated flapping membrane wing with a pair of low-speed stereo cameras and a triggered strobe light. Techniques are further detailed for separating the rigid body kinematic motions from the structural deformation. This is expected to be a necessary step, as a rigid wing (or a flexible wing in vacuum) is not expected to generate sufficient lift and thrust loads. Indeed, inspection of deformation results from flapping in both air and vacuum reveals the passive trailing edge feathering for thrust generation only in the former case. Future work will expand on the results presented here with an expansive series of wing topologies (combinations of membrane skin and batten structures) and measurements of flight loads for correlation with wing deformation.
Neodymium: YAG transconjunctival laser revision of late-failing filtering blebs.

Abstract Objective To study the effectiveness of neodymium:YAG (Nd:YAG) laser transconjunctival revision of late-failing filtering blebs. Design Retrospective, noncomparative case series. Participants Thirty consecutive patients from a glaucoma referral practice at the Ohio State University Department of Ophthalmology. Intervention Transconjunctival Nd:YAG laser revision of blebs diagnosed as failing secondary to episcleral fibrosis. Main outcome measure Reduction in intraocular pressure (IOP) and survival of bleb. Results Reduction in IOP was attained in 24 (80%) of 30 patients with a mean prelaser IOP of 21.21 mmHg and a mean 1-week postlaser IOP of 13.97 mmHg ( P P = 0.0008), 14.81 mmHg ( P P = 0.0003), respectively. Two-year data were available on a small number of patients (4) with a mean of 15.25 mmHg ( P = 0.0085). Mean time interval between trabeculectomy and laser revision was 31 months. Conclusion Late-failing filtering blebs are often amenable to Nd:YAG transconjunctival revision.
Self-assembling amphiphiles for construction of protein molecular architecture

Peptide-amphiphiles with collagen-model head groups and dialkyl chain tails have been synthesized and shown to self-assemble into highly ordered polyPro II like triple-helical structures when dissolved in aqueous subphases. Evidence for this self-assembly process has been obtained from (a) compression of stable peptide-amphiphile monolayers to molecular areas comparable with triple-helical areas, (b) circular dichroism spectra and melting curves characteristic of triple-helices, and (c) two-dimensional NMR spectra indicative of stable triple-helical structure at low temperatures and melted triple-helices at high temperatures. The thermal stability of the collagen-like structure in the peptide-amphiphile is substantially higher (ΔTm = 15−20 °C) than that of peptides without lipidation. The assembly process driven by the hydrophobic tail may provide a general method for creating well-defined protein molecular architecture using a minimalist peptide-based approach.