cssi/SciSciGPT-SciSciNet huggingface dataset:
Guided wave optoelectronic interconnects: their potential and future trends

We present in this paper the research status of polymer-based photonic integrated circuits (PICs) and their applications for VLSI optoelectronic interconnects. Demonstrated features of polymer-based PICs are delineated with GaAs and LiNbO3 integrated photonic devices as references. These unique features, including longer interconnection length, larger phase modulation index, graded-index (GRIN) characteristic, massive fanout capability and cost- effectiveness, make the polymer-based PICs very attractive for an optoelectronically interconnected VLSI system. The usefulness of polymer-based PICs for VLSI optoelectronic interconnects relies on not only the system requirements but also the processing temperatures over which polymer-based photonic devices are fabricated and then assembled. Optical bus design rules are provided in this paper to optimize the interconnection length while maintaining low cross talk and maximum bus packing density. Optoelectronically interconnected inter-MCM (multi-chip module) and intra-MCM will be the future research trend of optoelectronic interconnects. Intra-board and backplane optoelectronic interconnects represent the major milestones for the realization of these schemes.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The S2-Closure of a Rees Algebra

Let R be a Noetherian ring and let I be an ideal of R. We study when the Rees algebra of I satisfies the condition (S2) of Serre and, when this property is missing, to enable it in a finite extension of R[It].
Structural features facilitating the glutamate dehydrogenase catalyzed α-imino acid-α-amino acid interconversion

Abstract Glutamate dehydrogenase catalyzes the reversible oxidation of l -proline and l -pi-pecolic acid to the corresponding cyclic α-imino acids. The active substrates are the amino acid anion in one direction and the iminium ion in the other. The oxidation of the ester, amide, and N-methyl derivatives of l -proline by enzyme-NADP+ and the reduction of N-methyl-Δ1-tetrahydropyridinium ion by enzyme-NADPH do not proceed to a detectable extent under the experimental conditions. The methyliminium ion, however, undergoes facile nonenzymatic reduction by NADPH. If it is assumed that the nonenzymatic reaction reflects the structural requirements of the redox step of the enzymatic reaction, then the lack of reactivity of the tetrahydropyridinium ion toward enzyme-NADPH must be due to the instability of the central complex. It appears that the α-carboxylate and NH groups in the amino acid anion and in the α-imino acid are involved in binding the substrates to the enzyme-coenzyme complexes. We conclude that each of these active substrates binds to its appropriate enzyme-coenzyme complex through a hydrogen bond between its NH group and a basic enzyme group; there is also an ionic bond in the central complex between the α-carboxylate group of the active substrate and a positively charged enzyme group. The five-membered amino acid anions are more reactive toward enzyme-NADP+ than the six-membered ones. The same reactivity order is seen for the reduction of imino acids by enzyme-NADPH. Since these effects are also present in the nonenzymatic reduction by NADPH we ascribe the ring size effects on V K substrate primarily to those on the hydride-transfer step.
Analysis and optimization of prediction-based flow control in networks-on-chip

Networks-on-Chip (NoC) communication architectures have emerged recently as a scalable solution to on-chip communication problems. While the NoC architectures may offer higher bandwidth compared to traditional bus-based communication, their performance can degrade significantly in the absence of effective flow control algorithms. Unfortunately, flow control algorithms developed for macronetworks, either rely on local information, or suffer from large communication overhead and unpredictable delays. Hence, using them in the NoC context is problematic at best. For this reason, we propose a predictive closed-loop flow control mechanism and make the following contributions: First, we develop traffic source and router models specifically targeted to NoCs. Then, we utilize these models to predict the possible congestion in the network. Based on this information, the proposed scheme controls the packet injection rate at traffic sources in order to regulate the total number of packets in the network. We also illustrate the proposed traffic source model and the applicability of the proposed flow controller to actual designs using real NoC implementations. Finally, simulations and experimental study using our FPGA prototype show that the proposed controller delivers a better performance compared to the traditional switch-to-switch flow control algorithms under various real and synthetic traffic patterns.
Synthesis of TiB2–TiC/Fe nano-composite coating by laser surface engineering

Abstract The study explores the synthesis of TiB2 and TiC reinforced Fe-based nano-composite coating by laser surface engineering using Ti, B4C and Fe powder mixture as precursor. The effect of laser scanning speed on the size, morphology, and amount of nano-sized ceramic reinforcements were studied at laser fluence of 1111 J/cm2, 1667 J/cm2 and 3333 J/cm2 respectively. A bimodal microstructure with TiC and TiB2 particles dispersed in fine α-Fe matrix was evolved in the laser processed coatings. Besides, the nature of formation of nano-sized ceramic phase was examined. The laser synthesized nano-composite coating yielded 3–5 times increase in microhardness. It appears that the presence of nano-sized TiB2 and TiC particles coupled with the highly refined α-Fe matrix improves the hardness significantly. This coating offers the potential to increase the hardness and toughness simultaneously for developing wear-resistance coatings.
Structural duration analysis of management data

Abstract In this paper, duration data are viewed as being generated jointly by a natural mechanism and an economic agent's optimizing behavior. Between the two competing forces only the force which comes first is realized as an observed duration, with the source identified. This paper uses a structural approach to derive explicitly the joint distribution of the two duration variables, providing a structural economic motivation for the continuous-time competing-risks model. Issues of estimation and identification are discussed. A small simulation study examines properties of the model and the parameter estimators.
Perception of Self and Scholastic Underachievement in the Academically Capable

This study explored differences in the ways that underachievers and achievers perceive themselves and their relationships to the world around them. Achiever and underachiever groups, each consisting of 25 high school junior boys who were 115 IQ or better, were administered an apperceptive device. Protocols were analyzed in terms of six continua of perception. The statistical analyses utilizing t and F tests (with a predetermined 5 per cent Alpha level) demonstrated very significant differences between the groups. Underachievers showed significant and consistent differences from achievers in that they: (a) Saw themselves as less adequate, (b) Saw themselves as less acceptable to others, (c) Saw their peers as less acceptable, (d) Saw adults as less acceptable, (e) Showed an inefficient and less effective approach to problems, (f) Showed less freedom and adequacy of emotional expressions. Suggestions are made of certain factors that may produce underachievement and certain possible directions for future research.
Necrotizing cellulitis caused by Legionella micdadei

Legionella micdadei is primarily considered a pathogen of the pulmonary tract of immunocompromised patients, the majority of whom have been renal transplant recipients. We report the case of a necrotizing soft tissue infection in a cadaveric renal transplant recipient resulting in amputation of the left arm. Only one other extrathoracic bacteriologically documented L. micdadei infection has been reported in the literature.
Onsager's Regression Hypothesis Applied to Driftwave Fluctuations

Summary form only given. We analyze time correlation functions of drift wave fluctuations in the ion distribution function between spatial points separated along a fixed magnetic field in a plasma cylinder. The measurements are resolved in the component of ion velocity along the magnetic field. Even though Onsager's hypothesis was originally proposed for nearly-thermal fluctuations we observe that the time correlation function does resemble the linear response function even under circumstances where the plasma is unstable and highly non-thermal. In addition to a surprising level of agreement with Onsager's hypothesis of the drift wave fluctuations we also observe a component of the fluctuations that does not appear to be explained by the drift waves and which, in contrast to the drift wave component, lacks a number of symmetries (isotropy along the magnetic field and isotropy with respect to ion velocity direction along the magnetic field). We explore possible explanations for the second component.
Coregistered volumetric true 3D ultrasonography in image-guided neurosurgery

Intraoperative ultrasound (iUS) has emerged as a practical neuronavigational tool in image-guided open cranial procedures because of its low cost, easy implementation and real time image acquisition. Two-dimensional iUS (2DiUS) is currently the most common ultrasonic imaging tool used in the operating room (OR). However, gaps between imaging planes and limited volumetric sampling with 2DiUS often result in incomplete imaging of the internal anatomical structures of interest (e.g., tumor). In this paper, we investigate and evaluate the use of coregistered volumetric true three-dimensional iUS (3DiUS) generated from a broadband matrix array transducer (X3-1) attached to a Phillips iU22 intelligent ultrasound system. This 3DiUS scheme is able to provide full 3D sampling over a frustum-shaped volume with high resolution dicom images directly recovered by the ultrasound system without the need for free-hand sweeps or 3D reconstruction. Volumetric 3DiUS images were co-registered with preoperative magnetic resonance (pMR) images by tracking the spatial location and orientation of an infrared light-emitting tracker rigidly attached to the US scan-head following a fiducial registration and an iUS scan-head calibration. The registration was further refined using an imagebased scheme to maximize the inter-image normalized mutual information. In addition, we have utilized a coordinate system nomenclature and developed a set of static visualization techniques to present 3D US image data in the OR, which will be important for qualitative and quantitative analyses of the performance of 3DiUS in image-guided neurosurgery in the future. We show that 3DiUS significantly improves the imaging efficiency and enhances integration of iUS into the surgical workflow, making it appear to be promising for routine use in the OR.
PET studies of syntactic processing with auditory sentence presentation.

Sixteen subjects made plausibility judgments regarding auditorily presented cleft object and cleft subject sentences (It was the actress that the award thrilled; It was the award that thrilled the actress). rCBF increased in Broca's area, pars triangularis, when subjects processed the syntactically more complex cleft object sentences. The results are consistent with previous experiments using written materials and suggest that an increase in rCBF in Broca's area is associated with processing syntactically more complex sentences.
Inhibition of PGI2 signaling by miconazole in vascular smooth muscle cells.

Abstract Miconazole is widely used clinically as an anti-fungal agent and experimentally as a cytochrome P450 (CYP) inhibitor. In rat coronary arteries that produce PGI2 as the major arachidonic acid (AA) metabolite, activation of the large-conductance K+ (BK) channels in coronary arterial smooth muscle cells by AA was inhibited by miconazole but not by the CYP inhibitor SKF525A. Activation of BK currents in coronary smooth muscle cells by carbacyclin or iloprost also was inhibited by miconazole but not by SKF525A, suggesting that miconazole might have properties other than those of CYP inhibition. In addition, carbacyclin-induced dilation of isolated mesenteric arteries was inhibited by treatment with miconazole (51.9 ± 4.2% dilation in control, n = 7 versus 30.1 ± 4.0% with miconazole, n = 4, p
Detection and Quantification of N-Acetyl-β-D-glucosaminidase, Chitobiosidase, and Endochitinase in Solutions and on Gels

Procedures are described for the direct assay of N-acetyl-beta-glucosaminidase (EC 3.2.1.30), chitobiosidase, and endochitinase (EC 3.2.1.14) after separation on starch or polyacrylamide electrophoresis gels. The enzymes were visualized as fluorescent bands by using an agarose overlay containing 4-methylumbelliferyl derivatives of N-acetyl-beta-D-glucosaminide, beta-D-N,N'-di-acetylchitobioside, or beta-D-N,N',N"-triacetylchitotriose for N-acetyl-beta-glucosaminidase, chitobiosidase, or endochitinase, respectively. For quantitative assay of N-acetyl-beta-glucosaminidase and chitobiosidase in solutions, a rapid technique using nitrophenyl-N-acetyl-beta-D-glucosaminide and nitrophenyl-beta-D-N,N'-diacetyl-chitobiose, respectively, was used. Endochitinase activity was quantitatively measured by determining the percentage reduction in turbidity of a reaction mixture that contained purified colloidal chitin. Trichoderma harzianum strain P1 was shown to produce three kinds of chitinolytic enzymes, and there were multiple forms of some of these.
Rapid analysis of pharmaceuticals and excreted xenobiotic and endogenous metabolites with atmospheric pressure infrared MALDI mass spectrometry

Atmospheric pressure (AP) infrared (IR) matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) was demonstrated for the rapid direct analysis of pharmaceuticals, and excreted human metabolites. More than 50 metabolites and excreted xenobiotics were directly identified in urine samples with high throughput. As the water content of the sample was serving as the matrix, AP IR-MALDI showed no background interference in the low mass range. The structure of targeted ions was elucidated from their fragmentation pattern using collision activated dissociation. The detection limit for pseudoephedrine was found to be in the sub-femtomole range and the semi-quantitative nature of the technique was tentatively demonstrated for a metabolite, fructose, by using a homologous internal standard, sucrose. A potential application of AP IR-MALDI for intestinal permeability studies was also explored using polyethylene glycol.
Alloys created between immiscible elements

Abstract The development and understanding of alloys is one of the most important themes of physical metallurgy. Over the past four decades, the progress in modern processing techniques has enabled researchers to artificially create an increasing number of new alloys in systems that are immiscible in thermodynamic equilibrium. This possibility of alloying elements between which no alloys exist in nature offers exciting opportunities for many physics, chemistry, and materials science endeavors. One of the obvious questions that needs to be answered is exactly what kind of alloys have been, and can be, obtained in these systems with positive heat of mixing, in terms of the uniformity, the presence of short-to-medium range chemical and topological order/clustering, and the energy state of the new alloy phases. This issue was not adequately addressed before because, until recent years, simple diffraction measurements constituted the main method for the characterization of the alloys produced. In this article, we survey the alloys created in binary systems with positive heat of mixing. Our emphasis is on a systematic examination of the atomic-level structure, and calorimetric determination of the positive enthalpy of mixing, of several model binary alloys created between immiscible elements, covering both amorphous and crystalline solid solutions. Vapor-deposited alloys will be our primary focus, but alloys prepared via other processing routes or modeled in computer simulations will also be discussed. The experimental characterization results recently obtained using local environment probes will be reviewed, together with the insight gained through computer atomistic simulations. The local structures uncovered will be correlated directly with the thermodynamic properties. A full account of the thermodynamic and kinetic aspects of the phase selection and the details of the transformation mechanisms involved, on the other hand, is a much broader subject to be dealt with in a separate review.
Diethyl pyrocarbonate (DEPC) inhibits CO2 chemosensitivity in Helix aspersa

Central CO2 chemoreceptors in poikilothermic vertebrates may not regulate ventilation at a particular pH setpoint; central chemoreceptor responses may more accurately reflect the relative charge state (alpha) of the imidazole of histidine. We have tested the alphastat hypothesis in the terrestrial, air breathing, pulmonate snail, Helix aspersa, by chemically modifying histidine residues in the central CO2 chemoreceptor area of this animal using diethyl pyrocarbonate (DEPC). After focal application of 20 mM DEPC to the central CO2 chemoreceptor region, the pneumostome, a respiratory, CO2 responsive organ in the snail, no longer responded to hypercapnic, acidotic stimulation of the central chemoreceptor area. However, pneumostomal responses to hypoxic stimulation of the pneumostome and to focal stimulation of the central chemoreceptor area with sodium nitroprusside, a respiratory stimulant in H. aspersa, remained intact after DEPC treatment. Furthermore, DEPC treatment of the central chemoreceptor area blocked pneumostomal responses to ammonia pre-pulse treatment, which changes intracellular pH, while extracellular pH is held constant. These results resemble mammalian responses to DEPC treatment and indicate that central chemoreceptor responses in H. aspersa may originate from changes in the alpha of intracellular histidine residues.
To Choose or not to Choose: Equity in Connecticut in the Wake of Sheff v. O'Neill

This article considers the complex process of having students cross the boundaries of race, class, and culture in the Open Choice program, a remedy designed to reduce the racial, social, and economic isolation of Connecticut school children in the wake of the ruling in the Sheff v. O'Neill (1996) desegregation case. Using transcripts from three focus discussion groups, personal interviews, and a student forum, the authors present the voices and perspectives of students and parents who are crossing these boundaries, as well as the voices of educators they meet on the other side. A variety of issues and concerns emerge from the conversations that raise questions about the efficacy of Open Choice and busing, and their potential impact on student achievement. We argue that crossing boundaries of race, class, and culture requires a long-term commitment to fundamental social change and consistent efforts to raise the racial consciousness of educators through a statewide overhaul of professional development, spe...
Intraoperative digital real-time fluoroscopic arteriography for distal infrapopliteal arterial reconstruction.

La radioscopie digitale de haute resolution permet d'obtenir d'excellentes images TV biplanaires, agrandies ainsi que des films RX de toutes les fistules et des anastomoses distales. La duree de l'operation peut etre nettement diminuee
Biosensing with one-dimensional photonic bandgap structure

The optical properties of photonic bandgap (PBG) structures are highly sensitive to the geometry and refractive index. This makes PBG structures a good host for sensor applications. The binding of target species inside the PBG structure changes the refractive index of the material, which can be detected by monitoring the optical response of the device. One-dimensional PBG biosensors based on porous silicon (PSi) have been fabricated. The device is a microcavity, made of a symmetry breaking PSi layer (defect layer) inserted between two PSi Bragg mirrors. Narrow resonances are introduced in the photoluminescence and reflectance spectra. The large internal surface of the sensor is functionalized for the capture of target biological materials. When the sensor is exposed to the target, binding to the internal surface increases the effective optical thickness of the microcavity and thus causes a red shift of the optical spectrum. The sensor's sensitivity is determined by the morphology and geometry of the device. We will present the details of the materials science, sensor fabrication and optimization, and also describe experiments performed with biological targets.
Species and functors and types, oh my!

The theory of combinatorial species, although invented as a purely mathematical formalism to unify much of combinatorics, can also serve as a powerful and expressive language for talking about data types. With potential applications to automatic test generation, generic programming, and language design, the theory deserves to be much better known in the functional programming community. This paper aims to teach the basic theory of combinatorial species using motivation and examples from the world of functional programming. It also introduces the species library, available on Hackage, which is used to illustrate the concepts introduced and can serve as a platform for continued study and research.
Teaching technical writing to the engineering student: Industry's needs, the students' expectations

This paper describes the problem of teaching technical writing to engineering students who are convinced they will never need or use the skills. A possible solution to the problem is to use the case method. The case method changes the nature of the traditional classroom environment by reflecting life on the “outside.” This paper describes how the case method is used in one technical writing course and how it changed some students' minds about the importance of a technical writing course in helping them prepare for their professional careers. The ten-week syllabus is described and samples of “before” and “after” are offered.
Reconstituting rotational band structure from deformed boson expansions: Generic treatment

The usefulness of perturbative expansions in deformed bosons has been limited by difficulties associated with zero-frequency (Goldstone) modes. A method developed earlier by Marshalek and Weneser to overcome these difficulties was restricted to the case in which the broken-symmetry generators commute. The present paper shows how to extend the method to the non-Abelian case of three-dimensional rotation of axially symmetric deformed systems. Application is made to a generic anharmonic Hamiltonian constructed from random-phase-approximation modes.
Recent advances in hot-wire CVD R&D at NREL : From 18% silicon heterojunction cells to silicon epitaxy at glass-compatible temperatures

Our research aiming to improve silicon photovoltaic materials and devices extensively utilizes hot-wire chemical vapor deposition (HWCVD). We have recently achieved 18.2% heterojunction silicon solar cells by applying HWCVD a-Si:H front and back contacts to textured p-type silicon wafers. This is the best reported p-wafer heterojunction solar cell by any technique. We have also dramatically improved the quality of HWCVD silicon epitaxy and recently achieved 11 μm of epitaxial growth at a rate of 110 nm/min.
Regulation of cholesterol metabolism in a slow-growing hepatoma in vivo.

Abstract Cholesterol metabolism and its regulation are altered in hepatomas as compared to normal liver. We investigated parameters of cholesterol metabolism and their regulation in rats bearing the well-differentiated Morris hepatoma 9108. The numbers of membrane associated receptors recognizing chylomicron remnants, the lipoproteins that deliver dietary lipid to the liver, were substantially decreased in the 9108 tumor relative to the host liver. Cholesterol synthetic rates were 2–3-fold higher in the tumor, while the activity of 3-hydroxy-3-methylglutarylcoenzyme A reductase (EC 1.1.1.88), a rate-limiting enzyme for sterol synthesis, was elevated 6–14-fold. Although tumor free and esterified cholesterol contents were elevated, the activity of acylcoenzyme A:cholesterol acyltransferase (EC 2.3.1.26), the enzyme responsible for intracellular sterol esterification, was unchanged. Similar to the host liver, cholesterol synthesis and 3-hydroxy-3-methylglutarylcoenzyme A reductase were inhibited in the tumor when rats were fed a diet containing cholesterol, cholate and lard, and there was no effect on the numbers of chylomicron remnant recptors. Administering an intravenous bolus of very low density lipoproteins obtained from hypercholesterolemic rats caused an inhibition of tumor reductase activity, but had little effect on cholesterol content or cholesterol esterification. Thus, hepatoma 9108 expressed quantitative differences in cellular parameters involved in the uptake, metabolism, and synthesis of cholesterol and their susceptibility to regulation when compared with the host liver. These differences are best explained by changes in the hepatoma of multiple factors involved in the regulation of normal hepatic cholesterol metabolism.
Analysis of antiarrhythmic drug concentrations determined during electrophysiologic drug testing in patients with inducible tachycardias.

T he approved type IA antiarrhythmic drugs quinidine, procainamide and disopyramide are widely used in the treatment of cardiac rhythm disturbances and serum concentrations of these drugs are frequently obtained. These drug levels are routinely interpreted in the context of commonly cited “therapeutic ranges” and used to guide therapy decisions and manipulate dosages. The present study was undertaken to evaluate the value of isolated serum concentrations of antiarrhythmic drugs and to analyze the effect of concentration on concordance and discordance of response.
Comparison of Sampling Methods to Estimate the Number of Oriental Fruit Fly and Melon Fly (Diptera: Tephritidae) Captured in Traps

Three sampling methods (weight. volume, and grid) were used to estimate large numbers of melon fly, Dacus cucurbitae Coquillett, and oriental fruit fly, Dacus dorsalis Hendel, captured in traps. The weight method was significantly faster than either the volume or grid method and provided the most precise estimate of a known number of flies for both species. Sample sizes as small as 5% of the total insect weight resulted in precise estimates of the total number of insects. Regression equations for prediction of the number of melon flies and oriental fruit flies based on the dry weight of trap catches were calculated with coefficients of determination ( r 2) of 0.98.
Porcine endometrial prolactin receptors detected by homologous radioreceptor assay

Abstract Heterologous radioreceptor assays, commonly using ovine prolactin, may generate inconsistent results since prolactin (PRL) from one species may be recognized as growth hormone in another. Homologous radioreceptor assays (RRA) are most similar to the in vivo hormone-tissue receptor environment; however, lactogenic homologous RRAs have been reported only for mouse hepatic membranes. In this study, an assay system was developed to investigate homologous binding for porcine PRL in porcine uterine tissue. The pig does not produce a decidual PRL or a placental lactogen; yet, PRL affects uterine physiology during reproductively important events. Optimal binding conditions established for porcine PRL homologous RRA include 150 μg membrane, 45 000 cpm labeled porcine PRL and 500 μl sodium phosphate buffer pH 7.6, incubated at 25°C for 24 h. Binding of porcine PRL tracer is very low ( 2 (4 M), binding increases from 3 to 28%. Dissociation kinetics show a rate of 3.79 × 10 −6 /s initially, and then 1.63 × 10 −6 s. Competition for labeled PRL on binding sites with unlabeled porcine PRL results in 80% displacement with unlabeled porcine prolactin (NSB) of 7% at 1000 ng. Affinity constant generated from homologous inhibition assays is 0.326 × 10 8 M −1 . Porcine growth hormone (GH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) do not displace porcine PRL tracer. These data describe a lactogenic homologous RRA for porcine endometrial membranes similar to that previously reported for murine hepatic tissue. Homologous RRAs may allow elucidation of PRL receptor characteristics with more similarity to the in vivo hormone-receptor milieu.
Cognitive Science and the Problem of Semantic Content

By ‘cognitive science’ I mean the branch of cognitive psychology that incorporates the computer model, and that is sometimes known as ‘computational psychology’ and ‘information-processing psychology’ as well. My remarks are directed particularly against the version of cognitive science defended in recent writings by Jerry Fodor. By ‘the problem of semantic content’ I mean roughly the problem of explicating those features of a brain state or process by virtue of which it may properly be said to possess meaning or reference or truth value. Since I am primarily concerned with the account of semantic content implicated in Fodor’s version of cognitive science, I shall summarize that account before attempting to formulate the problem in a more precise manner.
Relationships between nonadiabatic bridged intramolecular, electrochemical, and electrical electron-transfer processes.

Fermi's golden rule is used to develop relationships between rate constants for electron transfer in donor−bridge−acceptor and electrode−bridge−acceptor systems and resistances across metal−bridge−electrode and metal−bridge−tip junctions. Experimental data on electron-transfer rates through alkanethiolate, oligophenylene, and DNA bridges are used to calculate the electronic coupling matrix element per state through these moieties. The formulation is then used to predict the resistance of these bridges between two gold contacts. This approach provides a straightforward method for experimentalists to assess the self-consistency between intramolecular electron-transfer rate constants and low-bias resistances measured for molecularly bridged junctions between two metallic contacts. Reported resistances for alkanethiolate bridges vary by a factor of 20, with predicted resistances falling within this range. However, comparisons between carboxylato and directly linked alkanethiolate bridges suggest differences between the coupling at the interface to either the redox center or the gold electrode in such systems. Calculated resistances for oligophenylene bridges are close to those measured experimentally in a similar oligophenylene system.
A note on the electorate's most preferred inflation rate

Nordhaus (1975) and MacRae (1977) have articulated theories of the political business cycle which allow one to estimate an inflation rate that is optimal in the sense that it will maximize the chance of a political party remaining in power. Central to the notion of a political business cycle is a preference function or iso-vote loss curve which reflects the willingness of the electorate to endure extra unemployment for the sake of a lower inflation rate. The authors assume that this tradeoff function is well behaved and can be approximated by a parabola or half circles. The electorate's most preferred inflation rate can be defined as that rate which will maximize the chance of an incumbent political party getting reelected for any possible variation in the unemployment rate. It is also the inflation rate which would presumably prevail in a democratic society if unemployment were not a problem. In constructing their voter preference curves involving a tradeoff between inflation and unemployment Nordhaus and MacRae both assumed that price stability, other things equal, is preferred by the electorate to either inflation or deflation. Alan Greenspan, has indicated that he and other governors of the Federal Reserve share this view and are willing to support a bill sponsored by Representative Stephen Neal which would require the Fed to pursue polices aimed at eliminating inflation within five years (Wessel, 1989). When parabolas representing a non "turnover contour" curve are fit to the election year inflation and unemployment rates which encompass all those cases where the incumbent political party did not loose the presidential election, however, the conclusion is that the most preferred inflation rate is positive and has been trending upward over time. The basic data on inflation, unemployment and the outcome of presidential elections from 1920-88 are presented in Table 1. For the entire period one can encompass all those non turnover cases where the incumbent political party did not loose the election by fitting a simple parabola to the data points for 1928, 1936 and 1988. Where U is the unemployment rate and P is the inflation rate,
O022 Suppressor of cytokine signaling-3 inhibits breast tumor kinase and STAT3

Introduction The proteins of the SOCS family are best characterized as negative regulators of cytokine signaling and inhibitors of Janus kinases (JAKs) that are bound to cytokine receptors. We describe the distinct ability of SOCS3 to inhibit the activity of breast tumor kinase (Brk), and evaluate the mechanisms by which SOCS3 suppresses Brk. Breast tumor kinase (Brk) is a non-receptor tyrosine kinase that is expressed in a majority of breast tumors, but not in normal mammary glands. One of the substrates of Brk is the signal transducer and activator of transcription 3 (STAT3), a transcription factor causally linked to cancer. Methods Co-immunoprecipitation assays were used to demonstrate SOCS3 binding to Brk, and protein–protein interactions were used to define the domains of Brk required to bind SOCS3. The ability of Brk to tyrosine phosphorylate STAT3 was used as a measure of its activity, and used to evaluate the effects of various deletions of SOCS3. The effect of SOCS3 expression was tested on proliferation of a breast cancer cell line expressing Brk. Results Results reveal SOCS3 inhibits Brk by binding primarily via its SH2 domain to phosphotyrosine residues of Brk. The main inhibitory effect of SOCS3 is mediated by the kinase inhibitory region (KIR). SOCS3 has only a modest effect on promoting Brk degradation, and this requires the carboxyl terminal SOCS box domain. Conclusion SOCS3 is the only known inhibitor of Brk, and knowledge of the mechanisms by which SOCS3 inhibits Brk may lead to methods that block Brk in cancer progression.
Inverse scattering for stratified elastic media

Abstract The trace method is applied to recover the Lame parameters λ and μ and the mass density ϱ of a stratified elastic medium.
Diphenylhydantoin Microdetermination in Serum and Plasma by UV Spectrophotometry

Abstract: A modified UV spectrophotometry procedure for determining diphenylhydantoin in 0.1-0.2 ml of serum is described. Improvement of previously described techniques was accomplished by modifying the extraction conditions and refluxing assembly. Continuous extraction of the oxidized diphenylhydantoin provided the maximum yield of benzophenone, resulting in optimal sensitivity as well as reproducibility of analytical values. Reliable clinical assays are achieved on 0.1 ml of serum containing 0.5 μg of diphenylhydantoin. Recovery of the drug from biological fluids is approximately 94%.
Increased dose density is feasible: a pilot study of adjuvant epirubicin and cyclophosphamide followed by paclitaxel, at 10- or 11-day intervals with filgrastim support in women with breast cancer.

Purpose: Because Cancer and Leukemia Group B 9741 trial showed a benefit for every 14-day administration of chemotherapy compared with every 21-day treatment, we hypothesized that even greater dose density would be more effective. We conducted a pilot trial to assess the feasibility of dose-dense chemotherapy consisting of a standard regime at 10- to 11-day intervals in the adjuvant/neoadjuvant setting. A 2-day window was allowed for scheduling logistics. Experimental Design: Thirty-nine women with early-stage breast carcinoma were accrued from April 2004 to October 2004. Median age was 47 years (range, 26-67 years). Patients received therapy with 100 mg/m2 epirubicin and 600 mg/m2 cyclophosphamide (EC) q 10 to 11 days for four cycles followed by 175 mg/m2 paclitaxel q 10 to 11 days for four cycles, all with filgrastim support (300 μg s.c. daily) from day 2 to 24 h before the next treatment. Results: Thirty-five (90%) patients completed all planned therapy. The median intertreatment interval was 10 days (range, 8-28 days). Cycles (80.7%) were delivered at no more than 10- to 11-day intervals. There were five dose reductions of 25% for grade 3 nonhematologic toxicity in five patients. Six (16%) patients developed febrile neutropenia defined as temperature >38°C with absolute neutrophil count <1,000/μL. All febrile neutropenia was during therapy with EC. Other grade 3 toxicities included bone pain, hand and foot syndrome, neuropathy, mucositis, nausea, and vomiting. Conclusions: Therapy with EC for four cycles followed by paclitaxel for four cycles at 10- to 11-day intervals is feasible. The ∼30% reduction in intertreatment interval compared with every 14-day treatment could increase the efficacy of adjuvant chemotherapy.
Global behavior of a multi-group SIS epidemic model with age structure

Abstract We study global dynamics of a system of partial differential equations. The system is motivated by modelling the transmission dynamics of infectious diseases in a population with multiple groups and age-dependent transition rates. Existence and uniqueness of a positive (endemic) equilibrium are established under the quasi-irreducibility assumption, which is weaker than irreducibility, on the function representing the force of infection. We give a classification of initial values from which corresponding solutions converge to either the disease-free or the endemic equilibrium. The stability of each equilibrium is linked to the dominant eigenvalue s ( A ) , where A is the infinitesimal generator of a “quasi-irreducible” semigroup generated by the model equations. In particular, we show that if s ( A ) 0 then the disease-free equilibrium is globally stable; if s ( A ) > 0 then the unique endemic equilibrium is globally stable.
Evidence for Pervasive Bioerosion of Silica Substrates in a Freshwater Peat Environment: ABSTRACT

Siliceous particles (30 to 100 µm) collected from freshwater peat deposits in the Okefenokee swamp show extensive effects of bioerosion. When viewed with the SEM these effects include: (1) depressions (similar to those produced by diatoms); (2) perforations (holes 2 µm in diameter); and (3) borings (holes > 2 µm in diameter). These features are most likely to be of biological origin because of their smooth surfaces and the consistency of the geometry of the cavities. The delicate nature of the eroded grains dictates that the biological agents responsible must have lived in the peat-forming environment. For example, monaxon sponge spicules have lost as much as half their original mass through hundreds of tubular microborings, rendering them far too fragil for transport. Heretofore, microborings have been observed to commonly occur on carbonate substrates, and in only two cases has bioerosion been reported in siliceous sediments in a marine environment. Our observations show that freshwater organisms are also capable of boring/dissolving silica, and that this form of degradation may play a major role in silicon mobility within peat-forming environments. End_of_Article - Last_Page 543------------
Beverage intake of girls at age 5 y predicts adiposity and weight status in childhood and adolescence

Background: Increased consumption of sweetened beverage has been linked to higher energy intake and adiposity in childhood. Objective: The objective was to assess whether beverage intake at age 5 y predicted energy intake, adiposity, and weight status across childhood and adolescence. Design: Participants were part of a longitudinal study of non-Hispanic white girls and their parents (n = 170) who were assessed biennially from age 5 to 15 y. At each assessment, beverage intake (milk, fruit juice, and sweetened beverages) and energy intake were assessed by using three 24-h recalls. Percentage body fat and waist circumference were measured. Height and weight were measured and used to calculate body mass index. Multiple regression analyses were used to predict the girls’ adiposity. In addition, at age 5 y, girls were categorized as consuming <1, ≥1 and <2, or ≥2 servings of sweetened beverages. A mixed modeling approach was used to assess longitudinal differences and patterns of change in sweetened beverage and energy intake, adiposity, and weight status by frequency of sweetened beverage intake. Results: Sweetened beverage intake at age 5 y, but not milk or fruit juice intake, was positively associated with adiposity from age 5 to 15 y. Greater consumption of sweetened beverages at age 5 y (≥2 servings/d) was associated with a higher percentage body fat, waist circumference, and weight status from age 5 to 15 y. Conclusion: These findings provide new longitudinal evidence that early intake of sweetened beverages predicts adiposity and weight status across childhood and adolescence.
Construction of maximum‐entropy density maps, and their use in phase determination and extension

Methods for constructing everywhere-positive electron-density maps with Fourier amplitudes matching those for arbitrarily large sets of observed data, utilizing dual-function methods for maximization of entropy, are described. Possible strategies for utilizing these maps for the determination and extension of phases in macromolecular structure determination are suggested, and problems are discussed.
Neuronal activity causes rapid changes of lateral amygdala neuronal membrane properties and reduction of synaptic integration and synaptic plasticity in vivo

Neuronal membrane properties dictate neuronal responsiveness. Plasticity of membrane properties alters neuronal function and can arise in response to robust neuronal activity. Despite the potential for great impact, there is little evidence for a rapid effect of activity-dependent changes of membrane properties on many neuronal functions in vivo in mammalian brain. In this study it was tested whether periods of neuronal firing lead to a rapid change of membrane properties in neurons of a rat brain region important for some forms of learning, the lateral nucleus of the amygdala, using in vivo intracellular recordings. Our results demonstrate that rapid plasticity of membrane properties occurs in vivo , in response to action potential firing. This plasticity of membrane properties leads to changes of synaptic integration and subsequent synaptic plasticity. These changes require Ca 2+ and hyperpolarization-activated ion channels, but are NMDA independent. Furthermore, the parameters and time course of these changes would not have been predicted from most in vitro studies. The plasticity of membrane properties demonstrated here may represent a basic form of in vivo short-term plasticity that modifies neuronal function.
Effects of normal faulting on fluid flow in an ore-producing hydrothermal system, Comstock Lode, Nevada

Abstract Normal faults in the Comstock Lode mining district, NV, USA, are delineated by low 18O belts and strong isotopic gradients perpendicular to strike. These faults perturb and also offset the regional pattern of δ18O contours produced by pervasive hydrothermal alteration of the Alta formation, and have preserved the down-dropped hanging wall rocks while exposing the footwall rocks to greater erosion. Fluid–rock interaction was greatly enhanced within >200-m-wide zones centered on the normal faults where permeability was increased and fluids were focused parallel to the fault plane. The effects of displacement and permeability enhancement around the faults are investigated using oxygen isotope profiles through the Comstock and Occidental faults and across steeper secondary normal faults such as the Coryell fault that may have formed after the principal faults were rotated to more shallow dips. Oxygen isotope profiles record both post-hydrothermal displacement and syn-deformational enhancement of fluid flow around the faults. Fluid focusing along normal faults perturbs the δ18O values by increasing the water–rock ratio. This isotopic effect can be mathematically described for any distance x from the fault using the formula: Δ f =A· e −bx 2 which is analogous to the fundamental solution for diffusion away from a plane source. The maximum magnitude of 18O depletion, A, depends on the effects of permeability, temperature, mineralogy, fluid isotopic composition and integrated fluid flux. The constant b is related to the scale of exchange enhancement around the fault. The characteristic width (w=1/√b) of the fluid focusing effects is remarkably similar at 100 m for all three faults examined. Coupling this isotope exchange effect with a step-function, which accounts for fault displacement, provides a good fit to the observed 18O fault profiles. The 18O distribution around faults can be used to infer relationships and timing among the processes of structural deformation, hydrothermal convection, and ore deposition in the Comstock district.
GRACE-Based Estimates of Terrestrial Freshwater Discharge from Basin to Continental Scales

In this study, new estimates of monthly freshwater discharge from continents, drainage regions, and global land for the period of 2003‐05 are presented. The method uses observed terrestrial water storage change estimates from the Gravity Recovery and Climate Experiment (GRACE) and reanalysis-based atmospheric moisture divergence and precipitable water tendency in a coupled land‐atmosphere water mass balance. The estimates of freshwater discharge are analyzed within the context of global climate and compared with previously published estimates. Annual cycles of observed streamflow exhibit stronger correlations with the computed discharge compared to those with precipitation minus evapotranspiration (P 2 E) in several of the world’s largest river basins. The estimate presented herein of the mean monthly discharge from South America (;846 km 3 month 21 ) is the highest among the continents and that flowing into the Atlantic Ocean (;1382 km 3 month 21 ) is the highest among the drainage regions. The volume of global freshwater discharge estimated here is 30 354 6 1212 km 3 yr 21 . Monthly variations of global freshwater discharge peak between August and September and reach a minimum in February. Global freshwater discharge is also computed using a global ocean‐atmosphere mass balance in order to validate the land‐ atmosphere water balance estimates and as a measure of global water budget closure. Results show close proximity between the two estimates of global discharge at monthly (RMSE 5 329 km 3 month 21 ) and annual time scales (358 km 3 yr 21 ). Results and comparisons to observations indicate that the method shows important potential for global-scale monitoring of combined surface water and submarine groundwater discharge at near‐real time, as well as for contributing to contemporary global water balance studies and for constraining global hydrologic model simulations.