cssi/SciSciGPT-SciSciNet huggingface dataset:
Simultaneous Observation of Phase-Stepped Photoelastic Images Using Diffraction Gratings

Phase-stepped photoelasticity is a powerful method for full-field stress analysis, but sequential collection of the multiple required images limits the technique to static loading applications. In an effort to collect four phase-stepped images simultaneously with a single camera for transient loading applications, we have developed a system that utilizes diffraction gratings, which are for separation of coherent monochromatic laser light. Two adjacent, perpendicularly oriented, 1D Ronchi rulings that are placed after a transparent sample split the light into equal intensity beams for each diffraction order. The four beams that are diffracted once in the x direction and once in the y direction transmit through arrays of analyzing polariscope elements, with different combinations of fast-axis orientations for four phased-stepped images. The mirrors and imaging lenses in the system work in concert to focus each beam onto separate quadrants of the same CCD. We demonstrate the system for stress analysis of compressive loading of a Homalite-100 disk. We can utilize this system for photoelastic analysis of time-dependent materials and of dynamic events, when equipped with a high-speed camera.
Fidelity test for through-focus or volumetric type of optical imaging methods

Rapid increase in interest and applications of through-focus (TF) or volumetric type of optical imaging in biology and other areas has resulted in the development of several TF image collection methods. Achieving quantitative results from images requires standardization and optimization of image acquisition protocols. Several standardization protocols are available for conventional optical microscopy where a best-focus image is used, but to date, rigorous testing protocols do not exist for TF optical imaging. In this paper, we present a method to determine the fidelity of the TF optical data using the TF scanning optical microscopy images.
Tying Hands, Sinking Costs, and Leader Attributes:

Do costly signals work? Despite their widespread popularity, both hands-tying and sunk-cost signaling have come under criticism, and there’s little direct evidence that leaders understand costly si...
Nonlinear transfer and temporal gain control in ON bipolar cells

The separation of visual input into discrete channels begins at the photoreceptor to bipolar cell synapse. Current models of the ON pathway describe the time-varying membrane voltage of ON bipolar cells as a linear function of light fluctuations. While this linearity holds under some visual conditions, stimulating the retina with full-field, high contrast flashes reveals a number of nonlinearities already present in the input current of ON bipolar cells. First, we show that the synaptic input to ON bipolar cells is asymmetric in response to equal flashes of opposite polarity. Next, we show that this asymmetry emerges because the responses to dark flashes increase linearly with contrast, whereas responses to bright flashes are highly rectified. We also describe how the outward current saturates in response to dark flashes of increasing duration. Furthermore, varying the inter-flash interval between a pair of high contrast flashes reveals a rapid, transient form of gain control that modulates both the amplitude and time course of the flash response. We develop a phenomenological model that captures the primary features of the ON bipolar cell response at high contrast. Finally, we discuss the implications of these nonlinearities in our understanding of how retinal circuitry shapes the visual signal.
Union Threat Effects and the Decline in Employer-Provided Health Insurance

Employer-provided health insurance decreased by an average of almost 0.6 percentage points per year for adults aged 18 to 64 who were working full-time in the private sector between 1983 and 2007. ...
Resorcin[4]arenes: A Convenient Scaffold To Study Supramolecular Self-Assembly and Host:Guest Interactions for the Undergraduate Curriculum

In response to the call for an increased emphasis from the American Chemical Society on including macromolecular studies in the undergraduate curriculum, a supramolecular-themed experiment was designed for undergraduate-level organic laboratory courses that provides a convenient platform to study physical behaviors of supramolecular assemblies. Students synthesize an easily purified resorcin[4]arene and characterize the product of its self-assembly via 1H NMR spectroscopy. These bowl-shaped molecules are noteworthy because of their propensity to self-assemble in organic solution in the presence of trace water or alcohol solvents. Upon self-assembly, the resulting hexamer adopts a well-defined molecular cage structure with a large internal cavity that can be used to explore host:guest chemistry. After completing the experiment, students are expected to gain a better understanding of electrophilic aromatic substitution, 1H NMR spectroscopy, supramolecular chemistry and self-assembly, and molecular recognition.
Getting the Word Out, Rain or Shine: The Impact of Message Features and Hazard Context on Message Passing Online

AbstractNetworked social media provide governmental organizations, such as the National Weather Service (NWS), the opportunity to communicate directly with stakeholders over long periods of time as...
Visible-light photocatalytic activation of N-chlorosuccinimide by organic dyes for the chlorination of arenes and heteroarenes

Abstract A variety of arenes and heteroarenes are chlorinated in moderate to excellent yields using N-chlorosuccinimide (NCS) under visible-light activated conditions. A screening of known organic dye photocatalysts resulted in the identification of methylene green as the most efficient catalyst to use with NCS. According to mechanistic studies described within, the reaction is speculated to proceed via a single electron oxidation of NCS utilizing methylene green under visible-light photoredox pathway. The photo-oxidation of NCS amplifies the electrophilicity of the chlorine atom of the NCS, thus leading to enhanced reactivity as a chlorinating reagent with aromatic substrates.
“Time is not a line.” Temporal gestures in Chol Mayan

Abstract The metaphorical mapping of time and space has been attested in a variety of languages and cultures around the world. Although much research has been devoted to documenting variations in the direction and orientation of such metaphorical timelines according to cross-linguistic differences, the inherent linearity of this model of temporal representation is rarely called into question. The present study provides gestural evidence which shows that speakers of Chol, a Maya language spoken in Chiapas, Mexico, do not conceptualize time in terms of such abstract mental timelines or axes. A description of temporal reference and temporal gesture in Chol is provided, focusing on how deictic (past/present/future) and sequential (earlier/later) relations between events are expressed in this language, followed by a qualitative analysis of the types of gestures that accompany these kinds of temporal expressions. It will be argued that, instead of reflecting the metaphorical mapping of time onto space in a timeline, temporal gestures in Chol often reflect the aspectual semantics of the sentences where they occur.
Initiation and early growth of the skull vault in zebrafish.

Abstract The zebrafish offers powerful advantages as a model system for examining the growth of the skull vault and the formation of cranial sutures. The zebrafish is well suited for large–scale genetic screens, available in large numbers, and continual advances in genetic engineering facilitate precise modeling of human genetic disorders. Most importantly, zebrafish are continuously accessible for imaging during critical periods of skull formation when both mouse and chick are physically inaccessible. To establish a foundation of information on the dynamics of skull formation, we performed a longitudinal study based on confocal microscopy of individual live transgenic zebrafish. Discrete events occur at stereotyped stages in overall growth, with little variation in timing among individuals. The frontal and parietal bones initiate as small clusters of cells closely associated with cartilage around the perimeter of the skull, prior to metamorphosis and the transition to juvenile fish. Over a period of ~30 days, the frontal and parietal bones grow towards the apex of the skull and meet to begin suture formation. To aid in visualization, we have generated interactive three–dimensional models based on the imaging data, with annotated cartilage and bone elements. We propose a framework to conceptualize development of bones of the skull vault in three phases: initiation in close association with cartilage; rapid planar growth towards the apex of the skull; and finally overlapping to form sutures. Our data provide an important framework for comparing the stages and timing of skull development across model organisms, and also a baseline for the examination of zebrafish mutants affecting skull development. To facilitate these comparative analyses, the raw imaging data and the models are available as an online atlas through the FaceBase consortium ( facebase.org ).
Simulation Methods for Teaching Sampling Distributions: Should Hands-on Activities Precede the Computer?

Sampling distributions are fundamental to an understanding of statistical inference, yet research shows that students in introductory statistics courses tend to have multiple misconceptions of this...
Is Collective Efficacy a Theory of Offending? Unraveling the Relationship between Individual-Level Perceptions of Collective Efficacy and Youth Offending

This study seeks to reaffirm the value of collective efficacy as a theory of offending and highlight a crucial individual-level mechanism through which collective efficacy may operate: individual-l...
Comparison of whole genome sequences of Streptococcus equi subsp. equi from an outbreak in Texas with isolates from within the region, Kentucky, USA, and other countries.

Abstract Strangles, caused by Streptococcus equi subspecies equi (S. equi) is an infectious disease of horses with worldwide distribution, but there are limited data available regarding strain variation using whole genome sequencing among and within outbreaks in the United States (US), and how US isolates compare with S. equi isolated globally. To address this knowledge-gap, we compared the whole genomes of 54 S. equi isolates from Texas and Kentucky and those of 230 publicly available sequences of S. equi isolates collected from other countries. Our results show that despite minimal variation among isolates within an outbreak some mutations do occur among individual outbreak isolates. Some S. equi strains from the US are closely related to S. equi isolates from other countries, likely reflecting international dissemination of isolates. Collectively, these data improve our understanding of phenotypic and genotypic variation of isolates within an outbreak, and the international distribution of S. equi. We also identify a novel variant of the S. equi M-protein, and observed cases of strangles that were caused by the modified-live vaccine but that were not recognized as vaccine-associated at the time of clinical sample submission.
Determination and analysis of allergen specific IgE in 1 028 children with allergic dermatosis

Objective To observe the differences in specific IgE of allergic diseases. Methods The allergens in 1 028 patients (including 606 cases of eczema/specific dermatitis, 319 Cases of urticaria, 103 cases of papular urticaria and prurigo) were detected by German Allergy Screen Immune mark method. Results There were statistically significant differences (P 3-year-old group was dust mite (10.77%), cockroach (3.52%), Penicillium notatum/Piptocephalis/ aspergillus fumigatus/aspergillus niger/Alternaria (21.32%), Short ragweed/artemisia/Humulus scandens/quinoa (14.73%). The positive rate of specific IgE against house dust in the third quarter was the highest (17.78%) and the difference was statistically significant (χ2=14.443, P=0.002). Among the statistically significant difference in the positive rate of specific IgE between eczema/atopic dermatitis in different age groups (χ2=10.204, P=0.006), the positive rate in the group of 1 to 3 years was the highest. Conclusions Different diseases, ages, and seasonal specific allergens are different, individualized treatment can be carried out according to disease types, ages and seasons. Key words: Anaphylaxis; Allergens; Immunoglobulin E; Child
Comparing Thermography and X-Ray Computed Tomography Analyses of Composite Helmets

The coupling of x-ray computed tomography (XCT) established baselines with thermographic evaluation could result in a system of inspection for defective personnel protection components at the depot level by technicians with moderate training. XCT inspection was used to determine and define damage baselines within components. These baseline components were scanned using thermography to establish corresponding thermal images. A limited catalog of thermal patterns was compiled relating the thermal pattern to components suitability for use. At the depot level thermography units could scan personnel protection components and the resulting thermal images compared with cataloged thermal images to insure components viability. This will result in lower life cycle cost and higher effectiveness of personnel protection components. This paper addresses a cursory study into the feasibility of such an approach.
Suppliers as Financiers of the Last Resort: The Effect of Exogenous Changes in Analyst Coverage on Trade Credit Use

We document a negative causal relationship between changes in the analyst coverage of buying firms and their use of trade credit, thus establishing an "information production" hypothesis of trade credit usage. We show that firms use trade credit to a greater extent when the extent of asymmetric information facing external financiers (such as banks) about buying firms increases, thus increasing suppliers' information advantage with respect to such external financers. We establish a causal relationship between trade credit use and analyst coverage using two different identification methodologies: first, using exogenous changes in the analyst coverage of firms following brokerage house mergers; and second, using an instrumental variable (IV) analysis. Our cross sectional analyses provide further support for the information production hypothesis. First, increases in trade credit usage following reductions in analyst coverage are smaller for firms with closer established lending relationships with banks and those incurring higher audit fees. Second, increases in trade credit usage following reductions in analyst coverage are larger for financially constrained firms and those headquartered in regions characterized by a higher extent of social capital.
Drug Positivity Findings from a Universal Umbilical Cord Tissue Drug Analysis Program in Appalachia.

Background West Virginia has high rates of opioid-related health crises and deaths that extend to pregnant women and newborns. Our institutional screening approach has included universal umbilical cord tissue drug analysis (UCTDA) since 2013. The objective of this study was to retrospectively report incidence of in utero drug exposure using UCTDA data. Methods Two sequential UCTDA data sets (October 2013 to September 2015, and October 2016 to September 2018) represent interrupted epochs given changes in interfaced data availability. UCTDA positivity (by drug class and parent drug) and numbers of drugs detected in each specimen were retrospectively analyzed. THC was removed from the analysis because of discontinuous testing, and 4 opioids were separated from the data set given the potential for both therapeutic and illicit use. Results UCTDA specimens that were positive for drugs (22% overall) decreased between Epochs 1 and 2, from 25% to 20%. Increased positivity was noted for hydrocodone (+407%), oxycodone (+240%), amphetamines (+506%), and cocaine (+417%). Fentanyl and morphine positivity decreased by 75% and 18%, respectively, whereas buprenorphine detection increased 195%. Most positive specimens (80% overall) had 1 drug present, but specimens positive for 2 to 6 discrete drugs were found. Conclusion Universal UCTDA allows for unbiased assessment of drug exposure in infants. With the additional knowledge of therapeutic indications for drug use, UCTDA may allow for analysis of trends in illicit drug use and the impact of interventions to curb neonatal abstinence syndrome.
Long-Term Inactivation of Sodium Channels as a Mechanism of Adaptation in CA1 Pyramidal Neurons

The hippocampus is involved in memory and spatial navigation. Many CA1 pyramidal cells function as place cells, increasing their firing rate when a specific place field is traversed. The dependence of CA1 place cell firing on position within the place field is asymmetric. We investigated the source of this asymmetry by injecting triangular depolarizing current ramps to approximate the spatially-tuned, temporally-diffuse depolarizing synaptic input received by these neurons while traversing a place field. Ramps were applied to rat CA1 pyramidal neurons in vitro (slice electrophysiology) and in silico (multi-compartmental NEURON model). Under control conditions, CA1 neurons fired more action potentials at higher frequencies on the up-ramp versus the down-ramp. This effect was more pronounced for dendritic compared to somatic ramps. We incorporated a five-state Markov scheme for NaV1.6 channels into our model and calibrated the spatial dependence of long-term inactivation according to the literature; this spatial dependence was sufficient to explain the difference in dendritic versus somatic ramps. Long-term inactivation reduced the firing frequency by decreasing open-state occupancy, and reduced spike amplitude during trains by decreasing occupancy in closed states, which comprise the available pool. PKC activators like phorbol ester phorbol-dibutyrate (PDBu) are known to reduce NaV long-term inactivation. PDBu application removed spike amplitude attenuation during spike trains in vitro, more visibly in dendrites, consistent with decreased NaV long-term inactivation. Moreover, PDBu greatly reduced adaptation, consistent with our hypothesized mechanism. Our synergistic experimental/computational approach shows that long-term inactivation of NaV1.6 is the primary mechanism of adaptation in CA1 pyramidal cells.
DECOMPOSITION APPROACH TO BUS NETWORK DESIGN

This paper presents a decomposition approach to bus network design in which the task of network design is accomplished through the optimization of a series of subproblems. Bus routes are classified into several types, each having a different development priority. The basis design unit in the proposed approach is a development stage. Only one type of bus route is to be considered in each stage. After the number of bus routes to be included in each stage is determined, the origins and destinations of potential routes are identified. Optimal alignment connecting each pair or origin and destination is subsequently located.
A decision-theoretic model of coordination and communication in autonomous systems

This thesis presents a formal model of rational, autonomous behavior in single- and multi-agent domains, together with its implementation--the Rational Reasoning System (RRS). The model is based on a notion of economic rationality, which directs an agent to maximize the expected utility of its interactions with the environment. Rationality is implemented by having an agent repeatedly calculate the expected utility of plans of action available to it, and execute the plan with the highest utility. In cases in which the agent is interacting with other agents, the calculation of the expected utility includes the anticipated actions of others. An agent predicts the actions of the other agents using the assumption that they also are rational. The fact that they may be using the same assumption about the original agent leads to a recursive nesting of beliefs. The formalism that expresses this recursion is called the Recursive Modeling Method (RMM), which can be shown to converge on the best choice of action for an agent after considering a finite number of levels of recursive models. RMM can be used to compute the expected utilities of possible messages the agent can exchange with others, thus allowing the agent to be rational in its communicative behavior. This method can be extended to account for the possibility of the messages being dishonest and not believed. RMM has led to a preliminary version of a recursive variant of the possible world semantics that provides for a natural distinction between the concepts of knowledge and belief, and facilitates both recursively nested deductive reasoning, useful for problems like the Three Wise Men puzzle, and recursive decision-theoretic reasoning for coordination and communication.
Synthesis and Catalytic Activity of Rh(I) Phosphine Complexes Attached to Polymethylsiloxanes

The largest portion of research on polymer attached homogeneous catalysts has dealt with the use of insoluble polymeric supports based on the polystyrene backbone.1 Work on soluble polymeric supports has received less attention as has the use of inorganic materials. For example, work on metal complexes attached to the siloxane backbone has not been extensive. A patent has been issued describing the preparation and use of insoluble diphenylphosphinylethylsilsesquioxanes as supports for Pt and Pd catalysts.2 Similar Rhodium containing siloxane polymers have been formed on the surface, of silica and their catalytic activity determined in the hydrogenation of olefins.3-5 Advantages of using soluble siloxane polymer supports could arise because of their high thermal stability, as well as good coating and mechanical properties.6 We wish to report here the synthesis of various soluble and insoluble siloxane supports that contain diphenylphosphine functional groups with their Rhodium (I) complexes.6 The catalysts have been tested in the hydroformylation of 1-hexene.
Forth as the basis for an integrated operations environment for a space shuttle scientific experiment

Over a period of three years, a FORTH-based system was developed by JPL for the operations of a major scientific instrument onboard the Space Shuttle. The software had to meet a very demanding operations environment where the interactiveness of the software was not merely desirable but essential to the success of the mission. Forth was chosen for its capability of integrating divergent software needs into an interactive package. The mission flown in October 1984 was beset with numerous hardware failures and challenged the capability of the system to its fullest.
Simplified labeling process for medical image segmentation

Image segmentation plays a crucial role in many medical imaging applications by automatically locating the regions of interest. Typically supervised learning based segmentation methods require a large set of accurately labeled training data. However, thel labeling process is tedious, time consuming and sometimes not necessary. We propose a robust logistic regression algorithm to handle label outliers such that doctors do not need to waste time on precisely labeling images for training set. To validate its effectiveness and efficiency, we conduct carefully designed experiments on cervigram image segmentation while there exist label outliers. Experimental results show that the proposed robust logistic regression algorithms achieve superior performance compared to previous methods, which validates the benefits of the proposed algorithms.
Desmin and intermediate filaments in muscle cells.

With electron microscopy, a morphological class of filaments with an average diameter of 100 A has been identified in many vertebrate cells. These filaments were initially referred to as intermediate filaments since their diameter is intermediate to those of the 60 A actin filaments and the 250 A microtubules in nonmuscle cells and intermediate to those of the 60 A actin filaments and the 150 A myosin filaments in muscle cells. Presently, intermediate filaments are commonly referred to as neurofilaments in neurons, glial filaments in glial cells, 10 nm filaments in fibroblastic cells, tonofilaments or keratin filaments in epiderimal and epithelial cells, and intermediate filaments in skeletal, cardiac, and smooth muscle cells. Due to their wide distribution and morphological similarity, it was originally believed that the major subunit of the intermediate filaments from these various sources would be highly conserved in its amino acid sequence as is the case with actin and tubulin. The recent isolation of intermediate filaments from a variety of avian or mammalian cell types has enabled investigators to characterize the subunit proteins of these different filament preparations and to determine the extent of their homology. By a number of criteria including peptide mapping, antibody cross-reactivity, isoelectric point and molecular weight, it was shown that the major protein subunit of the intermediate filaments from muscle cells (desmin), fibroblasts, glial cells, neurons, and epidermal and epithelial cells (keratins) was distinct (Benitz et al. 1976; Dahl and Bignami 1976; Davison et al. 1977; Schachner et al. 1977; Schlaepfer 1977; Franke et al. 1978; Lazarides 1978; Lazarides and Balzer 1978; Milstone and McGuire 1978; Schlaepfer and Freeman 1978; Starger et al. 1978; Sun and Green 1978).
Power Ultrasound Treatment of Listeria monocytogenes in Apple Cider

Inactivation experiments with Listeria monocytogenes 10403S, an ultrasound-resistant strain, were conducted at sublethal (20, 30, and 40 degrees C) and lethal (50, 55, and 60 degrees C) temperatures in saline solution (pH 7.0), acidified saline solution (pH 3.4), and apple cider (pH 3.4) with and without application of ultrasound (20 kHz, 457 mW.ml(-l)). The survival of recoverable L. monocytogenes 10403S in apple cider was evaluated, and the effects of temperature, ultrasound, pH, and food matrix on inactivation were studied. Application of ultrasound increased the inactivation rate at both sublethal and lethal temperatures. Additional death of L. monocytogenes 10403S was due to low acidity at the lethal temperatures. The reduction in surviving L. monocytogenes 10403S followed first order kinetics at sublethal temperatures, but at lethal temperatures, a two-section linear model described the inactivation behavior. The bactericidal effect of thermosonication was additive in apple cider. The survival tests of L. monocytogenes 10403S in apple cider indicated the possibility of using a mild treatment condition in combination with ultrasound to achieve a 5-log reduction in number of listerial cells.
Evaluation of utilizing 0.18-/spl mu/m PMOS transistors in a 2.4-GHz receiver

2.4-GHz PMOS low noise amplifiers (LNAs) fabricated in a 0.18-/spl mu/m CMOS process have /spl sim/16 dB transducer power gain and 3.5 dB noise figure (N.F.) at 5.4-mW power consumption, which is /spl sim/3 dB lower and 1 dB higher than those of NMOS LNAs fabricated in the same process. PMOS LNAs have 6-8 dB higher IIP/sub 3/. 2.4-GHz PMOS mixers have 6-dB conversion gain and /spl sim/ 8-dB double side band N.F. at 29-mW power consumption, The gain is /spl sim/ 3 dB lower while the N.F. is slightly lower than those of NMOS mixers. PMOS mixers have about 5-9 dB lower flicker noise. These indicate the feasibility of using PMOS transistors for RF applications, to improve noise isolation without adding any process modifications and cost.
Determination of small molecule ABAD inhibitors crossing blood-brain barrier and pharmacokinetics.

A major obstacle to the development of effective treatment of Alzheimer’s disease (AD) is successfully delivery of drugs to the brain. We have previously identified a series of benzothiazole phosphonate compounds that block the interaction of amyloid beta peptide (Aβ) with amyloid-beta binding alcohol dehydrogenase (ABAD). A selective and sensitive method for the presence of three new benzothiazole ABAD inhibitors in mouse plasma, brain and artificial cerebrospinal fluid has been developed and validated based on high performance liquid chromatography tandem mass spectrometry. Mass spectra were generated using Micromass Quattro Ultima “triple” quadrupole mass spectrometer equipped with Electrospray ionization interface. Good linearity was obtained over a concentration range of 0.05–2.5 µg/ml. The lowest limit of quantification and detection was 0.05µg/ml. All inter-day accuracies and precisions were within ±15% of the nominal value and ±20%, respectively, at the lower limit of quantitation. The tested compounds were stable at various conditions with recoveries >90.0 % (RSD<10%). The method used for pharmacokinetic studies of compounds in mouse cerebrospinal fluid, plasma, and brain is accurate, precise, and specific with no matrix effect. Pharmacokinetic data showed these compounds penetrate the blood–brain barrier (BBB) yielding 4–50 ng/ml peak brain concentrations and 2 µg/ml peak plasma concentrations from a 10mg/kg dose. These results indicate that our newly synthesized small molecule ABAD inhibitor have good drug properties with the ability to cross the blood brain barrier, which holds a great potential for AD therapy.
Aromatic biosynthesis. XII. Conversion of 5-dehydroquinic acid to 5-dehydroshikimic acid dy 5-dehydroquinase.

Abstract 5-Dehydroquinase, an enzyme that catalyzes the conversion of 5-dehydroquinic acid to 5-dehydroshikimic acid through removal of a molecule of water, has been extracted from E. coli and partially purified. The reaction apparently involves a single enzyme and has no demonstrable cofactor requirement. The activity of the enzyme is readily measured by virtue of the absorption peak of 5-dehydroshikimic acid at 234 mμ. The reaction is reversible, with an equilibrium constant of 15. Certain properties of the enzyme are described.
MELISSA: Mobile Electronic LSA Internet Server Search Agent

Searching the World Wide Web for desired information is becoming increasingly challenging with the growing number of web servers and pages. Commonly used search engines often return broken links, out-of-date information, and unrelated pages. This project presents an alternative to these search engines by describing an architecture for a mobile autonomous search agent. MELISSA searches Internet web servers on the user's behalf and reports results back to the user in real-time that are up-to-date and free of broken links. In addition, MELISSA suppresses most unrelated pages by applying Latent Semantic Analysis (LSA), a statistical method for extracting and representing meaning in text corpora. An experiment comparing MELISSA to the AltaVista Internet search engine reveals significant improvements in search engine performance.
Mössbauer line-shape parameters for 183W and 191Ir in metallic tungsten and iridium.

We have carried out precise M\"ossbauer line-shape analyses in tungsten and iridium metal using an exact representation of the line shape in transmission. By using exceptionally intense sources (\ensuremath{\sim}70 Ci for $^{183}\mathrm{Ta}$) and carefully chosen constraints between sets of M\"ossbauer-effect spectra, we have been able to make a quantitative test of the theory of final-state effects. The temperature dependence of the recoilless fraction, ${\mathit{f}}_{\mathit{a}}$(T), for $^{183}\mathrm{W}$ in tungsten metal has been determined to about 1% accuracy, which is an order of magnitude better than previous M\"ossbauer or x-ray investigations, between 80 and 1067 K. The Debye model fits our results from 80 through 968 K, with a Debye M\"ossbauer temperature of 336.5 K, when a correction for thermal expansion is included. The recoilless fraction data were used to derive a value of 8.76(10) for the internal conversion coefficient for the 46.5-keV transition in $^{183}\mathrm{W}$, with an approach based on the quasiharmonic approximation to the lattice vibrations, which determines the temperature dependence of the recoilless fraction. The interference parameters, times 100, that we find in this investigation of $^{183}\mathrm{W}$ in tungsten metal (46.5 keV) and $^{191}\mathrm{Ir}$ in iridium metal (129 keV), are -0.317(6) and -0.77(10), respectively. These values are both greater in magnitude than the theoretically calculated values by about 10%, although the $^{191}\mathrm{Ir}$ case has errors large enough that the comparison with theory is inconclusive. These results differ with theory, and would indicate that the theoretical calculations of interference need refinement if they are to be used in studies of time-reversal invariance.
An improved approach to predict far field for infinite planar structure in FDTD simulations

This paper presents an improved approach to predicting the far fields for infinite planar structures using the finite difference time domain techniques. We have found that the equivalent magnetic current decays much faster than the electric current on the surface of the Huygens' box above the patch antenna due to the presence of the PEC ground plane. Hence, we suggest that the equivalent principle and image theory should be applied to calculate the far field using only the equivalent magnetic current to reduce the size of the computational domain. The example of a single patch antenna and a patch antenna array are employed to validate the proposed approach.
Relative motions of fragments of the split comets: III. A test of splitting and comets with suspected multiple nuclei

A quantitative test of splitting for comets with suspected multiple nuclei has been formulated using a model which assumes the motions of cometary fragments to be due primarily to outgassing. The model expresses the relative motion of the cometary fragments in terms of the time of splitting and the differential force, which are determined by measurements of the position angle and the separation distance between fragments. The test is applied to 18 comets suspected of having multiple nuclei, of which the comets Sawerthal 1888 I, Campbell 1914 IV, Whipple-Fedtke-Tevzadze 1943 I, Honda 1955 V, Wild 1968 III and Tago-Sato-Kosaka 1969 IX were found to be clear cases of split comets and Davidson 1889 IV and Periodic Giacobini 1896 V were judged to be likely candidates. At least three of the secondary nuclei confirmed can be classified as short-lived companions, while only two appear to be persistent.
Miller coded pilot aided modulation schemes for digital mobile radio

The performance of Miller coded pilot aided modulation systems is studied by computer-aided design techniques. It is shown that the use of this nonredundant code may improve the bit error rate (BER) performance of pilot aided modulation schemes over similar uncoded coherent and noncoherent systems. Miller coded random data have a spectral density about 12 dB lower than uncoded data at and around the unmodulated carrier frequency. The use of this code reduces the interference between the data spectrum and the pilot tone, and hence improves the BER performance. This improvement is significant, particularly in low bit-rate systems where a relatively wide bandpass filter is required for pilot extraction and successful compensation for fading and Doppler shift caused phase variations. This improved BER performance is obtained with no redundancy, but at the cost of some spectral efficiency. >
Schema design for a molecular biology laboratory information management system

The development of the conceptual scheme for the database supporting the laboratory activities for the mapping phase of the Human Genome Project at Lawrence Berkeley Laboratory is discussed. This entailed recording the instances of molecular biology experiments, the data generated from the experiments, and the inventories of biological stocks and chemical compounds. The authors discuss the nature of the application, the major modeling problems they confront, and the methodology they have adopted to address some of these problems. The methodology they adopted combines elements of an extended entity-relation model with those of a data-flow model. >
Critical Pedagogy and Classroom Praxis

In this paper we argue for the incorporation of critical pedagogy in the teaching of sociology. We first establish the theoretical and emancipatory rationale for critical pedagogy with a review of the neomarxist concept of reproduction. We then examine a specific application of critical pedagogy in the sociology curriculum of Western Oregon University. We give particular attention to a course sequence on community organizing in which students have developed a successful tenants union that serves as a vehicle for both personal and social transformation.
Referral revisited: community financing schemes and emergency transport in rural Africa

Referral between first and second levels of care in rural African health systems is an extremely complex problem. Problems that have plagued the process of referral include poor service quality, low availability of trained personnel, inadequate supplies of drugs and medical diagnostic equipment and inadequate communication infrastructure. In this paper, the authors analyse the role of transport costs in the utilization of referral and how community health insurance schemes can help reduce the economic burden of transport costs, thereby improving referral utilization and health outcomes. Following the introduction, the authors provide a conceptual framework of the individual-, household- and community-level factors that affect referral in the rural African context, with particular emphasis on the role of the time and monetary costs of transport and the potential role of community risk-sharing schemes. The paper then presents a detailed case study from Kenya where a community has been experimenting with a health insurance scheme which provides emergency transport for emergency referral. Data from the past eight years of experience in northern Kenya suggests that support for the insurance scheme has depended on the reliability of the health system, as well as the seasons and various external problems, such as political interference, drought and insecurity. Conclusions drawn support the idea of community financing schemes for transport, not merely as a life-saving strategy in remote and resource-poor health infrastructures, but also as a means to help build trust in the health system itself and thus improve sustainability through local institutional support.
Characterizing the range of simulated prostate abnormalities palpable by digital rectal examination.

Abstract Background: Although the digital rectal exam (DRE) is a common method of screening for prostate cancer and other abnormalities, the limits of ability to perform this hands-on exam are unknown. Perceptible limits are a function of the size, depth, and hardness of abnormalities within a given prostate stiffness. Methods: To better understand the perceptible limits of the DRE, we conducted a psychophysical study with 18 participants using a custom-built apparatus to simulate prostate tissue and abnormalities of varying size, depth, and hardness. Utilizing a modified version of the psychophysical method of constant stimuli, we uncovered thresholds of absolute detection and variance in ability between examiners. Results: Within silicone-elastomers that mimic normal prostate tissue (21kPa), abnormalities of 4mm diameter (20mm 3 volume) and greater were consistently detectable (above 75% of the time) but only at a depth of 5mm. Abnormalities located in simulated tissue of greater stiffness (82kPa) had to be twice that volume (5mm diameter, 40mm 3 volume) to be detectable at the same rate. Conclusions: This study finds that the size and depth of abnormalities most influence detectability, while the relative stiffness between abnormalities and substrate also affects detectability for some size/depth combinations. While limits identified here are obtained for idealized substrates, this work is useful for informing the development of training and allowing clinicians to set expectations on performance.
AINTEGUMENTA and AINTEGUMENTA-LIKE6 Act Redundantly to Regulate Arabidopsis Floral Growth and Patterning

An Arabidopsis (Arabidopsis thaliana) flower consists of four types of organs arranged in a stereotypical pattern. This complex floral structure is elaborated from a small number of floral meristem cells partitioned from the shoot apical meristem during reproductive development. The positioning of floral primordia within the periphery of the shoot apical meristem depends on transport of the phytohormone auxin with floral anlagen arising at sites of auxin maxima. An early marker of lateral organ fate is the AP2/ERF-type transcription factor AINTEGUMENTA (ANT), which has been proposed to act downstream of auxin in organogenic growth. Here, I show that the related, AINTEGUMENTA-LIKE6 (AIL6)/PLETHORA3 gene acts redundantly with ANT during flower development. ant ail6 double mutants show defects in floral organ positioning, identity, and growth. These floral defects are correlated with changes in the expression levels and patterns of two floral organ identity genes, APETALA3 and AGAMOUS. ant ail6 flowers also display altered expression of an auxin-responsive reporter, suggesting that auxin accumulation and/or responses are not normal. Furthermore, I show that ANT expression in incipient and young floral primordia depends on auxin transport within the inflorescence meristem. These results show that ANT and AIL6 are important regulators of floral growth and patterning and that they may act downstream of auxin in these processes.
Ethanol up-regulates fatty acid uptake and plasma membrane expression and export of mitochondrial aspartate aminotransferase in HepG2 cells

To explain the increased plasma mitochondrial aspartate aminotransferase (mAspAT) observed in alcoholics, we cultured HepG2 hepatoma cells in ethanol. Acute (24 hour) exposure to 0, 20, 40, or 80 mmol/L ethanol produced a dose-dependent (r = .98) increase in mAspAT messenger RNA (mRNA) of < or = thirteen-fold, with no significant change in the cellular content of mAspAT or of several other enzymes. The recovery of mAspAT in the medium over 24 hours of ethanol exposure correlated with both ethanol concentration and with mAspAT mRNA (r = .90), reaching 808% of cellular enzyme content/24 hours at 80 mmol/L. Recovery of all other enzymes studied was < or = 20% of cellular content and unaffected by ethanol. Plasma membrane mAspAT content also correlated with mAspAT mRNA (r = .96) and mitochondrial levels were unchanged. No mitochondrial morphologic abnormalities were observed at any ethanol concentration studied. In cells cultured chronically at 0 to 80 mmol/L ethanol, fatty acid uptake Vmax increased in parallel with plasma membrane expression of mAspAT (r = .98). Cellular triglyceride content was highly correlated with Vmax. Thus, the data suggest that: 1) the increased plasma mAspAT observed in alcoholics may reflect pharmacologic upregulation of mAspAT mRNA and of mAspAT synthesis by ethanol; and 2) increased mAspAT-mediated fatty acid uptake may contribute to alcoholic fatty liver.
The THz Spectrum of Density Fluctuations of Water: The Viscoelastic Regime

Relevant advances in the knowledge of the water dynamics at mesoscopic scales are reviewed, while mainly focusing on the contribution provided by high resolution inelastic X-ray scattering (IXS). In particular it is discussed how the use of IXS has improved our understanding of viscoelastic properties of water at THz frequencies. This specifically involves some solid-like features such as the onset of shear wave propagation, a sound velocity surprisingly similar to the one of ice, and an anomalously low sound absorption coefficient. All these properties can be explained by assuming the coupling of THz density fluctuations with a structural relaxation process connected to the breaking and forming of hydrogen bonds (HBs). This review also includes more recent IXS results demonstrating that, upon approaching supercritical conditions, relaxation phenomena in water gradually lose their structural character becoming essentially collisional in character. Furthermore, GHz spectroscopy results on supercooled water, suggesting the occurrence of a structural arrest, are discussed. An overview of the new opportunities offered by next generation IXS spectrometers finally concludes this review.
Suppression of the pituitary follicle-stimulating hormone secretion during proestrus and estrus in rats by porcine follicular fluid: possible site of action.

These studies were designed to investigate the action of porcine follicular fluid (PFF) on the secretion of FSH and LH in cyclic fen lie rats. PFF was obtained from medium sized follicles and was charcoal treated to remove steroids. Control animals received pig serum (PS). Proestrous rats were injected ip with 1 ml PFF or PS at 1100 or 1800 h, or at both times. Sequential blood collections were obtained at 1300, 1600, and 1900 h proestrus and at 0800, 1100, and 1400 h on estrus. When PFF was injected at 1100 h, plasma FSH levels were significantly depressed on proestrous afternoon but not on estrous morning. In rats treated with PFF at 1800 h, FSH was significantly lower only at 0800 h on estrous morning. When two injections of PFF were given to rats at 1100 and 1800 h, plasma FSH was markedly reduced at 1600 and 1900 h proestrus and at 0800 and 1100 h estrus. In contrast, plasma LH and progesterone in proestrous rats were only altered when two PFF injections were given. All PFF-treated rats ovulated and ...
Brain vasopressin and sodium appetite

Intraventricular injections of vasopressin (VP) and antagonists with varying degrees of specificity for the VP receptors were used to identify the action of endogenous brain VP on 0.3 M NaCl intake...
The Dynamics of the Wealth Distribution and the Interest Rate with Credit Rationing

are uniquely determined, and wealth dispersion among individuals or firms is irrelevant. Introducing credit rationing into the Solow model modifies these conclusions. Multiple stationary interest rates and wealth distributions can exist because higher initial rates can be self-reinforcing through higher credit rationing and lower capital accumulation. The wealth accumulation process is ergodic in every steady state, but wealth mobility is lower with higher steady-state interest rates. Aggregate output is higher in steady states with lower interest rates because credit is better allocated. Short-run interest rate or distribution shocks can be self-sustaining and can have long-run effects on output through the induced dynamics of the wealth distribution and credit rationing.