cssi/SciSciGPT-SciSciNet huggingface dataset:
Online workflow management and performance analysis with stampede

Scientific workflows are an enabler of complex scientific analyses. They provide both a portable representation and a foundation upon which results can be validated and shared. Large-scale scientific workflows are executed on equally complex parallel and distributed resources, where many things can fail. Application scientists need to track the status of their workflows in real time, detect execution anomalies automatically, and perform troubleshooting -- without logging into remote nodes or searching through thousands of log files. As part of the NSF Stampede project, we have developed an infrastructure to answer these needs. The infrastructure captures application-level logs and resource information, normalizes these to standard representations, and stores these logs in a centralized general-purpose schema. Higher-level tools mine the logs in real time to determine current status, predict failures, and detect anomalous performance.
Interfacial morphology of low-voltage anodic aluminium oxide

X-ray reflectivity (XRR) and neutron reflectivity (NR), as well as ultra-small-angle X-ray scattering (USAXS), are used to examine the in-plane and surface-normal structure of anodic films formed on aluminium alloy AA2024 and pure aluminium. Aluminium and alloy films up to 3500 A thick were deposited on Si wafers by electron beam evaporation of ingots. Porous anodic aluminium oxide (AAO) films are formed by polarizing at constant voltage up to 20 V noble to the open circuit potential. The voltage sweet spot (5 V) appropriate for constant-voltage anodization of such thin films was determined for both alloy and pure Al. In addition, a new concurrent voltage- and current-control protocol was developed to prepare films with larger pores (voltages higher than 5 V), but formed at a controlled current so that pore growth is slow enough to avoid stripping the aluminium substrate layer. USAXS shows that the pore size and interpore spacing are fixed in the first 10 s after initiation of anodization. Pores then grow linearly in time, at constant radius and interpore spacing. Using a combination of XRR and NR, the film density and degree of hydration of the films were determined from the ratio of scattering length densities. Assuming a chemical formula Al2O3·xH2O, it was found that x varies from 0.29 for the native oxide to 1.29 for AAO grown at 20 V under concurrent voltage and current control. The average AAO film density of the porous film at the air surface is 2.45 (20) g cm−3. The density of the `barrier' layer at the metal interface is 2.9 (4) g cm−3, which indicates that this layer is also quite porous.
Double ionization of helium by protons and antiprotons in the energy range 0.30 to 40 MeV

We present an ab initio calculation of the double ionization of helium by protons and antiprotons, using the forced impulse method. Cross sections are larger for antiprotons than for protons, in accord with recently reported experimental results.
Constitutive Relations of High Temperature Solders

This study focuses on microelectronic package design for the oil and natural gas drilling of wells with depths in excess of 20,000 ft, where package temperatures can exceed 204°C. At these high temperatures, solder interconnect sites are subject to fatigue and creep failures due to the stress generated by the thermal expansion mismatch between various components in the package. Typically this phenomenon is modeled by finite element analysis (FEA) to predict the number of cycles to failure. To ensure meaningful model results, however, accurate time and temperature-dependent mechanical properties are needed. This study examines five solders suitable for high temperature: 90Pb-10Sn, 95Sn-5Sb, 92.5Pb-5Sn-2.5Ag, 95Pb-5In, and 93Pb-3Sn-2Ag-2In. Uniaxial tension tests of the solder wires are carried out on a MTS servohydraulic machine using wedge grips. To evaluate the time-dependence on deformation, a strain rate study was carried out at 0.5%/sec, 1%/sec, and 5%/sec. Nanoindentation of solder wire is performed and compared to the corresponding solder wires tested through uniaxial tension tests. Dynamic nanoindentation through continuous stiffness measurement is performed on the wires to obtain the indentation data less sensitive to creep of the material, as well as to assess the effect of indentation depth on elastic modulus for each solder. One purpose of nanoindentation testing is to determine its suitability for the mechanical testing of soft solders. Mechanical properties obtained from these tests will be used in future modeling studies to estimate the cyclic fatigue life of these solders under thermal loading.Copyright © 2007 by ASME
Supporting Concern-Based Regression Testing and Prioritization in a Model-Driven Environment

Traditional regression testing and prioritization approaches are bottom-up (or white-box). They rely on the analysis of the impact of changes in source code artifacts, identifying corresponding parts of software to retest. While effective in minimizing the amount of testing required to validate code changes, they do not leverage on specification-level design and requirements concerns that motivated these changes. Model-based testing approaches support a top-down (or black box) testing approach, where design and requirements models are used in support of test generation. They augment code-based approaches with the ability to test from a higher-level design and requirements perspective. In this paper, we present a model-based regression testing and prioritization approach that efficiently selects test cases for regression testing based on different concerns. It relies on traceability links between models, test cases and code artifacts, together with user-defined properties associated to model elements. In particular we describe how to support concern-based regression testing and prioritization using TDE/UML, an extensible model-based testing environment.
Integrating virtual and biochemical screening for protein tyrosine phosphatase inhibitor discovery.

Protein tyrosine phosphatases (PTPs) represent an important class of enzymes that mediate signal transduction and control diverse aspects of cell behavior. The importance of their activity is exemplified by their significant contribution to disease etiology with over half of all human PTP genes implicated in at least one disease. Small molecule inhibitors targeting individual PTPs are important biological tools, and are needed to fully characterize the function of these enzymes. Moreover, potent and selective PTP inhibitors hold the promise to transform the treatment of many diseases. While numerous methods exist to develop PTP-directed small molecules, we have found that complimentary use of both virtual (in silico) and biochemical (in vitro) screening approaches expedite compound identification and drug development. Here, we summarize methods pertinent to our work and others. Focusing on specific challenges and successes we have experienced, we discuss the considerable caution that must be taken to avoid enrichment of inhibitors that function by non-selective oxidation. We also discuss the utility of using “open” PTP structures to identify active-site directed compounds, a rather unconventional choice for virtual screening. When integrated closely, virtual and biochemical screening can be used in a productive workflow to identify small molecules targeting PTPs.
Multiple-access insights from bounds on sensor localization

In ad hoc location-aware sensor networks, unlocalized sensors can estimate their locations based on the triangulation of range measurements from location-aware sensors or ''anchors'', whose locations are known or estimated a priori. In this paper, we investigate the relationship between multiple-access design parameters and the accuracy of location estimation in ad hoc sensor networks. Bounds on the average localization accuracy in a packet-based sensor network with time-of-arrival (TOA) based distance estimation are used to investigate the connection between the average effective throughput of packets and the average localization accuracy. On this basis, we (i) develop an analytical framework that allows us to analyze the relationship between network parameters and the average localization accuracy obtained in ad hoc sensor networks with a spread-spectrum physical layer, and (ii) show that, for such networks, minimizing the average localization error is equivalent to maximizing the average effective throughput. We further demonstrate that the developed framework allows the extraction of the optimal network parameters that maximize localization accuracy. The trends in the localization accuracy with respect to the network parameters observed through analysis are then validated via simulation studies. Finally, some aspects of the modeling of location-aware sensor networks that warrant investigation and require more sophisticated modeling strategies are listed.
Designer psychostimulants in urine by liquid chromatography-tandem mass spectrometry.

Designer psychostimulants are known by recreational drug users to produce a complex array of adrenergic and hallucinogenic effects. Many of these drugs are not targeted during routine toxicology testing and as a consequence, they are rarely reported. The purpose of this study was to develop a procedure for the detection of 15 psychostimulants in urine using liquid chromatography–tandem mass spectrometry (LC-MS/MS), specifically 2,5-dimethoxy-4-bromophenethylamine (2C-B), 2,5-dimethoxy-4-chlorophenethylamine (2C-C), 2,5-dimethoxy-4-methylphenethylamine (2C-D), 2,5-dimethoxy-4-ethylphenethylamine (2C-E), 2,5-dimethoxyphenethylamine (2C-H), 2,5-dimethoxy-4-iodophenethylamine (2C-I), 2,5-dimethoxy-4-ethylthiophenethylamine (2C-T-2), 2,5-dimethoxy-4-isopropylthiophenethylamine (2C-T-4), 2,5-dimethoxy-4-propylthiophenethylamine (2C-T-7), 2,5-dimethoxy-4-bromoamphetamine (DOB), 2,5-dimethoxy-4-chloroamphetamine (DOC), 2,5-dimethoxy-4-ethylamphetamine (DOET), 2,5-dimethoxy-4-iodoamphetamine (DOI), 2,5-dimethoxy-4-methylamphetamine (DOM), and 4-methylthioamphetamine (4-MTA). Analytical recoveries using solid-phase extraction were 64–92% and the limit of detection was 0.5 ng/mL for all drugs except 2C-B (1 ng/mL). The assay was evaluated in terms of analytical recovery, precision, accuracy, linearity, matrix effect, and interferences. The technique allows for the simultaneous detection of 15 psychostimulants at sub-ng/mL concentrations.
Comparison of Coronary Artery Stenting Outcomes in the Eras Before and After the Introduction of Drug-Eluting Stents

Background— Few studies have compared medium-term outcomes for drug-eluting stents (DES) and bare metal stents, and most are relatively small randomized controlled trials. Furthermore, since the introduction of DES, there has been increased use and duration of use of clopidogrel, statins, and other evidence-based therapies. The purpose of the present study was to compare outcomes for patients who underwent stenting in the eras before and after the introduction of DES. Methods and Results— New York state patients undergoing stenting in all nonfederal hospitals in the state were studied. Patients were excluded if they had a previous revascularization. Risk factors that were significant predictors of adverse outcomes were used to adjust adverse outcome rates. The study included 11 436 patients who received stents between October 1, 2002, and March 31, 2003, and 12 926 patients who underwent stenting between October 1, 2003, and March 31, 2004. Death rates, the combined end point of death and myocardial infar...
Current breast cancer risks of hormone replacement therapy in postmenopausal women

The controversies surrounding hormone replacement therapy have left many women confused and afraid. Providers have been faced with long-standing assumptions challenged by an abundance of new data in the past few years, with little guidance on how to interpret these findings. The objective of this paper is to provide a framework for understanding breast cancer risk associated with postmenopausal hormone replacement therapy, with a particular focus on how observational studies and randomised trials provide complementary information. This framework considers the data on risks of various hormonal preparations, the profiles of women at risk, and ends with an expert opinion in this context.
Diffusion of intensity-modulated near-infrared light in turbid media

Light propagation in turbid media can be described by photon diffusion. In the frequency domain, sinusoidally intensity-modulated light gives rise to diffusive waves which have a coherent front. In a homogeneous medium, the wave front propagates with a constant phase velocity and the amplitude attenuates exponentially as the diffusional wave advances. We have studied the diffusion approximation to the one-speed linear transport equation with a sinusoidally intensity modulated point source of particles and performed experiments using frequency domain detection methods on homogeneous scattering and absorbing media to test the applicability of the above mentioned transport equation to photon migration in turbid media. We have used the analytical solutions of the linear transport equation in homogeneous, infinite media to determine via a simple analysis of our frequency domain data the linear scattering and absorption coefficients.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Detection and Measurement of Experimentally Produced Aortic Regurgitation by Means of Indicator-Dilution Curves Recorded from the Left Ventricle

In dogs studied without thoracotomy the detection of immediately appearing indicator in the left ventricle following its injection approximately 1 cm downstream from the aortic valve can be used as a reliable index of the presence or absence of aortic regurgitation. With this type of injection and under the conditions of these experiments, the ratio of the area encompassed by the immediately appearing portion of the dilution curve recorded from the left ventricle to the area encompassed by the primary portion of the curve recorded at the femoral artery bears a close positive correlation (correlation coefficient: 0.9) to the severity of aortic regurgitation as estimated by back perfusion of the valve at necropsy. Within limitations, the position of the tip of the sampling catheter in the left ventricle in dogs with aortic regurgitation is not an important determinant of the amount of immediately appearing indicator detected in this chamber. Furthermore, although the amount of indicator detected in the left ventricle following injections of very short duration is time-dependent, if the duration of the injection is extended to cover the full systolic or diastolic phase of one heartbeat or continues over one or more heartbeats, the exact timing of this injection in relation to the cardiac cycle is not an important determinant of this variable. It is concluded that under these conditions the positive correlation established between the amount of immediately appearing dye detected in the left ventricle (expressed as the regurgitant fraction) and the severity of aortic regurgitation determined by back perfusion at necropsy can be used as a valid means of estimating the severity of aoritic regurgitation in dogs. The applicability of this indicator-dilution method to the study of clinical aortic reguragitation merits further study.
Feedback phosphorylation of the yeast a-factor receptor requires activation of the downstream signaling pathway from G protein through mitogen-activated protein kinase.

The two yeast pheromone receptors, the a and α-factor receptors, share many functional similarities: both G protein-coupled receptors couple to the same downstream signal transduction pathway, and both receptors undergo feedback regulation involving increased phosphorylation on their C-terminal domains in response to ligand challenge. The present work, which focuses on the signaling mechanism controlling this feedback phosphorylation, indicates one striking difference. While the α-factor-induced phosphorylation of the α-factor receptor does not require activation of the downstream G protein-directed signaling pathway (B. Zanolari, S. Raths, B. Singer-Kruger, and H. Riezman, Cell 71:755–763, 1992), the a-factor-induced phosphorylation of the a-factor receptor (Ste3p) clearly does. Induced Ste3p phosphorylation was blocked in cells with disruptions of various components of the pheromone response pathway, indicating a requirement of pathway components extending from the G protein down through the mitogen-activated protein kinase (MAPK). Furthermore, Ste3p phosphorylation can be induced in the absence of the a-factor ligand when the signaling pathway is artificially activated, indicating that the liganded receptor is not required as a substrate for induced phosphorylation. While the activation of signaling is critical for the feedback phosphorylation of Ste3p, pheromone-induced gene transcription, one of the major outcomes of pheromone signaling, appears not to be required. This conclusion is indicated by three results. First, ste12Δ cells differ from cells with disruptions of the upstream signaling elements (e.g., ste4Δ, ste20Δ, ste5Δ, ste11Δ, ste7Δ, or fus3Δ kss1Δ cells) in that they clearly retain some capacity for inducing Ste3p phosphorylation. Second, while activated alleles of STE11 and STE12 induce a strong transcriptional response, they fail to induce a-factor receptor phosphorylation. Third, blocking of new pheromone-induced protein synthesis with cycloheximide fails to block phosphorylation. These findings are discussed within the context of a recently proposed model for pheromone signaling (P. M. Pryciak and F. A. Huntress, Genes Dev. 12:2684–2697, 1998): a key step of this model is the activation of the MAPK Fus3p through the Gβγ-dependent relocalization of the Ste5p-MAPK cascade to the plasma membrane. Ste3p phosphorylation may involve activated MAPK Fus3p feeding back upon plasma membrane targets.
Vigilant vector: Heart-specific promoter in an adeno-associated virus vector for cardioprotection

Repeated bouts of ischemia in the heart lead to fibrosis and eventually to heart failure. Although certain genes, such as SOD or hemoxygenase and antisense to AT(1)R, ACE, and (beta(1)-AR can provide short-term protection of the heart from ischemia, there is no known mechanism for constantly responding to repeated incidences of ischemia. We hypothesized that a "vigilant vector," designed to be expressed specifically in the heart and switch on therapeutic genes only during hypoxia, would provide cardioprotection. To attain cardiac specificity, we inserted an MLC2v promoter into an adeno-associated virus (AAV) designed to deliver AS to AT(1)R and gfp. In in vitro experiments in cardiomyocytes (H9C2 cells), the MLC2v-AAV-gfp drove gene expression in all cells at levels comparable to a cytomegalovirus (CMV) promoter. In in vivo experiments, the rAAV-MLC2v-gfp was injected intravenously into mice or rats. Green fluorescence protein (GFP) DNA was located in kidney, heart (right and left ventricle), lung, adrenal and spleen. GFP mRNA, however, was expressed only in the heart and absent in other tissues. To switch on the rAAV transgene during ischemia, we inserted a hypoxia response element (HRE). This upregulates transcription when O(2) levels are low. Thus, there are 4 components to the vigilant vector; a gene switch (HRE), a heart-specific promoter (MLC2v), a therapeutic gene (AS-AT(1)R) and a reporter gene (gfp). To silence or lower basal level of expression while retaining specificity, we have reduced the length of the MLC2v promoter from 3 kb to 1775 bp or 281 bp. The truncated promoter is equally effective in heart specific expression. Preliminary studies with the rAAV-HRE-gfp in vitro show an increased expression in 1% O(2) in 4 to 6 hours. By adding additional hypoxia-inducible factor (HIFalpha) (5 microg), the MLC2v-gfp expression is increased by 4-fold in 1% O(2). Further amplification of the gene to 400-fold in 1% O(2) can be achieved with a double plasmid. The construct may serve as a prototype "vigilant vector" to switch on therapeutic genes in specific tissue with physiological signals.
Managing colonial alterity: narratives of race, space and labor in Durban, 1870–1920

Abstract After being annexed by the British in 1844, the colony of Natal was administered through the mechanisms of indirect rule, which created a division between the subjects and spaces of a modern, urban European domain and a ‘primitive’, rural African realm. Towards the end of the nineteenth century, this implied spatial division began to dissolve as a growing economy drew large numbers of Indian and African workers into the colony's cities. This paper examines the impacts of these changes in the city of Durban, through a reading of European public sentiments about the presence of these ‘others’ within the city. Laboring bodies became sites of public anxiety about the potential ‘contamination’ of the social order, and this led to increasing attempts to identify and contain these bodies through new forms of juridical and administrative control. These policies served to redraw the spatial boundaries of subjectivity around race as the privileged category determining rights and residence within the city, and in this way Durban's urban history serves as an exemplar of a more pervasive socio-spatial epistemology of race and whiteness.
Purification of beta cells from rat islets by monoclonal antibody-fluorescence flow cytometry

Fluoresceinated monoclonal antibody plus flow cytometry was used to purify beta cells from mixed pancreatic islet endocrine cell populations. A2B5, a monoclonal antibody to a glycolipid on the surface of cells of neuroendocrine origin, was incubated with single cells dissociated from rat pancreatic islets. Antibody-bound cells were labeled with fluoresceinated goat F(ab')2 antimouse immunoglobulin and highly fluorescent cells were separated from less fluorescent cells on a Coulter EPICS IV cell sorter. Sorted cell populations were analyzed by radioimmunoassay for insulin, glucagon, and somatostatin. The highly fluorescent cell population was enriched sixfold for insulin-containing beta cells, indicating that islet beta cells are relatively enriched in A2B5 antigen and can be partially purified by this method.
The timing of UV mutagenesis in yeast: continuing mutation in an excision-defective (rad1-1) strain.

Mutation induction by ultraviolet light was studied in excision-defective (rad1-1) strains of Saccharomyces cerevisiae. Information about the timing of mutations in relation to postirradiation DNA replication was obtained. The experimental system involved pedigree analysis of G1 diploid cells and subsequent tetrad analysis of the mitotic segregants to detect mutations. The mutation pattern of rad1-1 strains differed from that of wild type in two respects: (1) few or none of the mutations affected both strands of the DNA, (2) mutations appeared as frequently in the second postirradiation mitotic generation as in the first. The data have led to the following conclusions about the mutation process in excision-defective (rad1-1) yeast: (a) Mutations are not fixed prior to the first postirradiation round of DNA replication. (b) Unexcised thymine dimers persist as mutagenic lesions through repeated postirradiation cell divisions. (c) Heteroduplex repair is involved in the mutation process. (d) Overlapping daughter-strand gaps are not a prerequisite for mutation. (e) The results provide no evidence that error-prone repair in this strain is inducible rather than constitutive. The data also show that (f) all 2-strand mutations (whole-colony mutants) induced in yeast by exposure to low levels of ultraviolet light are associated with excision repair, and that (g) essentially all lesions induced in excision-proficient strains have been excised at the time of the second round of postirradiation DNA synthesis.
Genetics of sunflower alcohol dehydrogenase: Adh 2 ,nonlinkage to Adh 1 and Adh 1 early alleles

Alcohol dehydrogenase (ADH) isozymes in annual sunflowers (Helianthus annuus) are dimers whose subunits are produced by two genes, Adh 1 and Adh 2 .The codominant F and S alleles of Adh 1 produce the slower-migrating set of three isozymes. The faster-migrating set of three isozymes is controlled by Adh 2 , which also has at least two alleles, F and S. Hybridization experiments indicated that the Adh 2 alleles segregate in expected Mendelian fashion and that Adh 1 and Adh 2 are not linked. A third common 1-locus allele is designated early (E) because when homozygous it results in a blank at the 1FF isozyme position in mature seeds, but in developing seeds produces a normal-appearing band at the 1FF position. Hybridization studies showed that the early alleles segregated normally. Correlation between genotype and presence or absence of isozymes electrophoretically intermediate between those of Adh 1 and Adh 2 suggests that four intergenic isozymes may be formed as a result of dimerization of the four basic subunits. Studies of zymograms of developing seeds suggest that the remaining but inconstant zymogram bands are mature seed isozymes which have altered charges during early morphogenesis and thus are developmental artifacts.
Forecasting crop yield using remotely sensed vegetation indices and crop phenology metrics

Abstract We used data from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) in association with county-level data from the United States Department of Agriculture (USDA) to develop empirical models predicting maize and soybean yield in the Central United States. As part of our analysis we also tested the ability of MODIS to capture inter-annual variability in yields. Our results show that the MODIS two-band Enhanced Vegetation Index (EVI2) provides a better basis for predicting maize yields relative to the widely used Normalized Difference Vegetation Index (NDVI). Inclusion of information related to crop phenology derived from MODIS significantly improved model performance within and across years. Surprisingly, using moderate spatial resolution data from the MODIS Land Cover Type product to identify agricultural areas did not degrade model results relative to using higher-spatial resolution crop-type maps developed by the USDA. Correlations between vegetation indices and yield were highest 65–75 days after greenup for maize and 80 days after greenup for soybeans. EVI2 was the best index for predicting maize yield in non-semi-arid counties ( R 2 = 0.67), but the Normalized Difference Water Index (NDWI) performed better in semi-arid counties ( R 2 = 0.69), probably because the NDWI is sensitive to irrigation in semi-arid areas with low-density agriculture. NDVI and EVI2 performed equally well predicting soybean yield ( R 2 = 0.69 and 0.70, respectively). In addition, EVI2 was best able to capture large negative anomalies in maize yield in 2005 ( R 2 = 0.73). Overall, our results show that using crop phenology and a combination of EVI2 and NDWI have significant benefit for remote sensing-based maize and soybean yield models.
Regeneration of transected rat sciatic nerves after using isolated nerve fragments as distal inserts in silicone tubes

Abstract We determined blood vessel and perineurial fascicle densities as well as axonal numbers in regenerated rat sciatic nerves 8 weeks after the nerves had been transected, the proximal stumps placed into the proximal ends of silicone tubes, and isolated fragments of nerve placed into the distal ends of the same tubes. The data are compared with data from the normal nerve and from regeneration in a similar paradigm in which the distal stumps were used as the inserts into the distal end of the silicone tubes. A major difference between the two regeneration paradigms was that axons were discouraged from reaching the periphery when the distal insert was an isolated fragment and encouraged to reach the periphery when the distal insert was the distal stump. We found that fascicle and blood vessel densities were greater than normal but less than with the distal stump as the distal insert. Thus we concluded that the nature of the distal insert had a bearing on how many vessels and perineurial fascicles were formed during regeneration in these conditions. Myelinated axon numbers did not differ in the two conditions whereas there were more unmyelinated axons with the isolated distal stump as the distal insert. Thus at this regeneration time the numbers of myelinated axons were not as dependent on the nature of the distal insert as were the numbers of unmyelinated axons. Finally the length of the gap had a great influence on the numbers of axons that regenerated. These data quantitate to some extent the regenerative responses under these experimental conditions and confirm that isolated pieces of nerve may be effective in promoting axon growth into silicone tubes, a finding that may ultimately have clinical significance.
Radiocarbon dating of a core from Long Island sound

Abstract Radiocarbon measurements sequentially with depth in a diver-obtained core from Long Island Sound has been interpreted in terms of sediment accumulation rates and sources of organic carbon in the sediment. A sediment accumulation rate of 0·075 ± 0·013 cm year −1 is determined from the data below 10 cm in the core. An age of 2320 year BP is obtained for the sediment-water interface by extrapolation. This means that the dominant carbon component preserved in the core is soil-derived. The contributions of fossil fuel carbon and bomb radiocarbon associated with plankton are also evaluated.
Graphene for Tunable Nanophotonic Resonators

Local electro-optic modulation of nanophotonic structures is important for many applications. Here, we show that one can achieve efficient tunability of the nanostructures by coupling them to graphene. The easy electrical control of graphene allows a large modulation of these graphene-clad nanophotonic devices. We describe electrostatic tuning of a metallic as well as a dielectric resonator coupled to graphene. A large change, both in resonator linewidth and resonance frequency is observed. The experimental data match the theory very well indicating that the changes in the resonator are solely coming due to graphene.
Dissimilarity of mechanisms for evocation of escape and avoidance responding in dogs

Two groups of dogs were compared on the ability of an aversive Pavlovian CS to evoke a negatively reinforced instrumental response. For one group, the instrumental training was avoidance; for the other, escape. When presented alone, the CS evoked the instrumental response only from the avoidance group. Failure of the CS to evoke the response from the escape group poses difficulties for theories which characterize the initiation of avoidance responses as “escapes” from CS.
Sex and age structured matrix model applied to harvesting a white tailed deer population

A simple two-sex density dependent matrix model was applied to simulate the effects of harvesting deer (Odocoileus virginianus borealis Miller) with harvesting of only males, with harvesting of only females, and with harvesting of both males and females. When both males and females were harvested the relation between harvest and rate of harvest was a parabola. At the maximum sustainable harvest most of the deer harvested were fawns with several 1-year-olds and a few 2- and 3-year-olds also harvested. If only males were harvested, yield increased asymptotically with increased harvest effort and there was no maximum sustainable yield. Deer abundance remained near the carrying capacity but nearly all of the deer were female. If only females were harvested, the harvest increased to a maximum and then decreased but the harvest was much smaller than when both males and females were harvested.
Conductivity-based strain monitoring and damage characterization of fiber reinforced cementitious structural components

In recent years, a new class of cementitious composite has been proposed for the design and construction of durable civil structures. Termed engineered cementitious composites (ECC), ECC utilizes a low volume fraction of short fibers (polymer, steel, carbon) within a cementitious matrix resulting in a composite that strain hardens when loaded in tension. By refining the mechanical properties of the fiber-cement interface, the material exhibits high tolerance to damage. This study explores the electrical properties of ECC materials to monitor their performance and health when employed in the construction of civil structures. In particular, the conductivity of ECC changes in proportion to strain indicating that the material is piezoresistive. In this paper, the piezoresistive properties of various ECC composites are thoroughly explored. To measure the electrical resistance of ECC structures in the field, a low-cost wireless active sensing unit is proposed. The wireless active sensing unit is capable of applying DC and AC voltage signals to ECC elements while simultaneously measuring their corresponding voltages away from the signal input. By locally processing the corresponding input-output electrical signals recorded by the wireless active sensing units, the magnitude of strain in ECC elements can be calculated. In addition to measuring strain, the study seeks to correlate changes in ECC electrical properties to the magnitude of crack damage witnessed in tested specimens. A large number of ECC specimens are tested in the laboratory including a large-scale ECC bridge pier laterally loaded under cyclically repeated drift reversals. The novel self-sensing properties of ECC exploited by a wireless monitoring system hold tremendous promise for the advancement of structural health monitoring of ECC structures.
Sleep State Switching

We take for granted the ability to fall asleep or to snap out of sleep into wakefulness, but these changes in behavioral state require specific switching mechanisms in the brain that allow well-defined state transitions. In this review, we examine the basic circuitry underlying the regulation of sleep and wakefulness and discuss a theoretical framework wherein the interactions between reciprocal neuronal circuits enable relatively rapid and complete state transitions. We also review how homeostatic, circadian, and allostatic drives help regulate sleep state switching and discuss how breakdown of the switching mechanism may contribute to sleep disorders such as narcolepsy.
An evaluation of flow-stratified sampling for estimating suspended sediment loads

Abstract Flow-stratified sampling is a new method for sampling water quality constituents such as suspended sediment to estimate loads. As with selection-at-list-time (SALT) and time-stratified sampling, flow-stratified sampling is a statistical method requiring random sampling, and yielding unbiased estimates of load and variance. It can be used to estimate event yields or to estimate mean concentrations in flow classes for detecting change over time or differences from water quality standards. Flow-stratified sampling is described and its variance compared with those of SALT and time-stratified sampling. Time-stratified sampling generally gives the smallest variance of the three methods for estimating storm yields. Flow-stratified sampling of individual storms may fail to produce estimates in some short-lived strata because they may have sample sizes of zero. SALT will tend to give small samples and relatively high variances for small stroms. For longer and more complex hydrographs, having numerous peaks, flow-stratified sampling gives the lowest variance, and the SALT variance is lower than that of time-stratified sampling unless the sample size is very large. A desirable feature of flow-stratified sampling is that the variance can be reduced after sampling by splitting strata, particularly high flow strata that have been visited just once, and recalculating the total and variance. SALT has the potential to produce the lowest variance, but cannot be expected to do so with an auxiliary variable based on stage.
Molecular dynamics investigations of the effects of debris molecules on the friction and wear of diamond

Abstract The friction between two diamond surfaces placed in sliding contact has been investigated using molecular dynamics simulations. These simulations show that the friction between two hydrogen-terminated diamond (111) surfaces is significantly reduced when methane molecules are placed between the diamond surfaces compared to the same two surfaces in the absence of the debris, or third-body, molecules. Macroscopic experiments that have examined the friction of diamond on diamond in the presence of debris (Hayward and Field, Proc. Inst. Mech. Eng., IMechE Conf. 1 (1987) 205) show similar trends. The specific atomic-scale motions which lead to the reduced friction and to the deformation of the methane molecules are identified.
Vacuum ultraviolet radiation as a probe of rare gas plasmas

Abstract A study of the structure of electromagnetically produced shocks has been made which illustrates a technique for measurements of either photoionization cross sections, σ i , or number densities, n i , of plasma particles. This technique utilizes measurements of intensity ratios, I / I 0 , due to plasma absorption of ultraviolet radiation, which is governed by the Lambert-Beers law, I = I 0 exp (-Σ i σ i n i L ) where L is the length of the absorption path. Due to the complex band structure of diatomic molecules, this experiment used instead a rare gas, xenon, to study number densities of Xe and Xe + . Plots of neutral and ion densities as a function of time show clearly the shock front defined by a sharp rise in particle density. Relaxation times and effects due to precursors were also studied.
Medicare Reform — Now Is the Time

Reforming Medicare, which serves persons who are 65 years of age or older and many persons with disabilities, is a popular topic whenever the program's solvency is perceived to be at stake. Given t...
On levels in arrangements of lines, segments, planes, and triangles

We consider the problem of bounding the complexity of the k th level in an arrangement of n curves or surfaces, a problem dual to, and an extension of, the well-known k-set problem. Among other results, we prove a new bound, O(nk 5/3 ) , on the complexity of the k th level in an arrangement of n planes in R 3 , or on the number of k -sets in a set of n points in three dimensions, and we show that the complexity of the k th level in an arrangement of n line segments in the plane is \(O(n\sqrt{k}\alpha(n/k))\) , and that the complexity of the k th level in an arrangement of n triangles in 3-space is O(n 2 k 5/6 α(n/k)) . 26 June, 1998 Editors-in-Chief: la href=../edboard.html#chiefslJacob E. Goodman, Richard Pollackl/al 19n3p315.pdf yes no no yes
Adaptive smart sensor webs with predictive control for workflow and resource management in dynamic environments

A novel predictive controller framework is discussed for integrated smart sensing and resource management in a distributed intelligent sensor network with sensor nodes whose useful active lifetime is significantly shorter than the required lifetime of the sensor system. Past sensor network research has focused on security and communication, but largely ignored the overall dynamic resource management issue of such distributed systems. Our contribution is in integrated control optimization and resource management algorithms to ensure proper functioning of distributed sensors in extremely limited bandwidth, power, and storage. In this paper, we present a novel genetic algorithm (GA) for real-time system control and resource management that handles multiple conflicting objectives and constraints in the distributed system. We suggest using a GA-based predictive controller to give optimal actions that account for future states and future possible events while estimating the optimal control action policy. Our framework is suitable for dynamic environments where the desired system performance and resource usage changes dynamically while being constrained by limited amount of resources.
Effects of fluid properties and pipe diameter on two-phase flow patterns in horizontal lines

Abstract Extensive new data have been obtained on the transitions between two-phase flow patterns during co-current gas liquid flow in horizontal lines. Fluid properties were varied in a systematic manner to determine the effects of liquid viscosity, liquid density, interfacial tension and gas density. Line sizes varied from 1.2 to 5 cm for most of the tests. Visual observations were supplemented by an analysis of pressure drop fluctuations and hence the present data are believed to be less subjective than most past observations. The transition data from the present tests, as well as available literature data, were compared to the most frequently used transition line correlations. In almost all cases serious deficiencies were observed. Revised dimensionless correlations which fit present data, and those previously available, are presented.
Effects of electrode particle morphology on stress generation in silicon during lithium insertion

Abstract We study the effects of particle morphology and size on stress generation during Li insertion into Si particles using a fully coupled diffusion-elasticity model implemented in a finite element formulation. The model includes electrochemical reaction kinetics through a Butler–Volmer equation, concentration-dependent material properties, and surface elasticity. Focusing on two idealized geometries (hollow spheres and cylinders), we simulate stresses during Li insertion in Si. These systems describe a wide variety of morphologies that have been fabricated and studied experimentally, including particles, nanowires, nanotubes, and porous solids. We find that stresses generated in solid particles during Li insertion decrease as particle radii decrease from μm-scale, but reach a minimum at about 150 nm. Surface stresses then begin to dominate the stress states as the particle size continues to decrease. The minimum occurs at larger radii for hollow particles. We also find that hollow particles experience lower stresses than solid ones, but our results suggest that there is not a significant difference in maximum stress magnitudes for spherical and cylindrical particles. Studying the influence of concentration-dependent elastic moduli we find that while they can significantly influence stress generation for potentiostatic insertion, their role is minimal when surface reaction kinetics are considered.
Retrospective c-erbB-2 immunostaining in aspiration cytology of breast cancer

Fifty fine-needle aspiration cytologies of breast that were diagnosed as carcinomas were retrieved from the files and retrospectively evaluated for the expression of c-erbB-2 oncoprotein using standard immunocytochemical methods. Corresponding histologic sections of all tumors were similarly studied. Seventeen fine-needle aspirates (34%) reacted positively for the presence of c-erbB-2 oncoprotein. All but one (32%) of the corresponding tissue sections were also positive for c-erbB-2 by immunohistochemistry. All positive cases were infiltrative ductal carcinomas with a preponderance of the comedo type. Positive reactions were localized in the cytoplasmic membrane of tumor cells. The staining was either present in all cells throughout a tumor, or it was completely absent. We conclude that immunocytochemistry for c-erbB-2 oncoprotein can be performed on fine-needle aspiration cytology samples that are previously fixed and stained with the Papanicolaou technique. Furthermore, the sensitivity of immunostaining results are comparable to that obtained in histologic sections. Diagn Cytopathol 1994; 11:262–265. © 1994 Wiley-Liss, Inc.
Optical network of silicon micromachined sensors

The Honeywell Technology Center, in collaboration with the University of Wisconsin and the Mobil Corporation, and under funding from this ARPA sponsored program, are developing a new type of `hybrid' micromachined silicon/fiber optic sensor that utilizes the best attributes of each technology. Fiber optics provide a noise free method to read out the sensor without electrical power required at the measurement point. Micromachined silicon sensor techniques provide a method to design many different types of sensors such as temperature, pressure, acceleration, or magnetic field strength and report the sensor data using FDM methods. Our polysilicon resonant microbeam structures have a built in Fabry-Perot interferometer that offers significant advantages over other configurations described in the literature. Because the interferometer is an integral part of the structure, the placement of the fiber becomes non- critical, and packaging issues become considerably simpler. The interferometer spacing are determined by the thin-film fabrication processes and therefore can be extremely well controlled. The main advantage, however, is the integral vacuum cavity that ensures high Q values. Testing results have demonstrated relaxed alignment tolerances in packaging these devices, with an excellent Signal to Noise Ratio. Networks of 16 or more sensors are currently being developed. STORM (Strain Transduction by Optomechanical Resonant Microbeams) sensors can also provide functionality and self calibration information which can be used to improve the overall system reliability. Details of the sensor and network design, as well as test results, are presented.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A liquid-state theory for electron correlation functions and thermodynamics

Abstract Correlation functions play an important role in determining the structural and energetic properties of electronic systems. However, exact results are available only for ideal systems free of electrostatic interactions. Here we present a liquid-state method that combines classical mapping of the Pauli exclusion principle with the universality ansatz of the bridge functional. We show excellent agreement of the new method with quantum Monte Carlo simulation for predicting the electronic correlation functions and thermodynamic properties of uniform electron systems.
A systematic approach to stabilizing EBA-175 RII-NG for use as a malaria vaccine.

Region II of the erythrocyte-binding antigen (EBA-175 RII) has been identified as a promising target for a malaria vaccine. A systematic approach to identify optimal preformulation conditions of a non-glycosylated (NG) antigen, EBA-175 RII-NG, has been developed. This approach consists of development of an empirical temperature/pH phase diagram, high throughput stabilizer screening and aluminum salt adjuvant adsorption studies. Using these physical methods, we developed a stable formulation for EBA-175 RII-NG at pH 6.0 with sucrose and Brij® 35 as stabilizers and Adju-Phos® as an adjuvant. This approach should be generally applicable to guiding the development of stable vaccine formulations.