cssi/SciSciGPT-SciSciNet huggingface dataset:
On the Use of a Protic Ionic Liquid with a Novel Cation To Study Anion Basicity

The need for reliable means of ordering and quantifying the Lewis basicity of anions is discussed and the currently available methods are reviewed. Concluding that there is need for a simple impurity-insensitive tool, we have sought, and here describe, a new method using NMR spectroscopy of a weak base, a substituted urea, 1,3-dimethyl-2-imidazolidinone (DMI), as it is protonated by Bronsted acids of different strengths and characters. In all cases studied the product of protonation is a liquid (hence a protic ionic liquid). NMR spectroscopy detects changes in the electronic structure of the base upon interaction with the proton donors. As the proton-donating ability, that is, acidity, increases, there is a smooth but distinct transition from a hydrogen-bonded system (with no net proton transfer) to full ionicity. The liquid state of the samples and high concentration of nitrogen atoms, despite the very low natural abundance of its preferred NMR-active isotope ((15) N), make possible the acquisition of (15) N spectra in a relatively short time. These (15) N, along with (13) C, chemical shifts of the carbonyl atom, and their relative responses to protonation of the carbonyl oxygen, can be used as a means, sensitive to anion basicity and relatively insensitive to impurities, to sort anions in order of increasing hydrogen bond basicity. The order is found to be as follows: SbF6 (-) ClO4 (-) >FSO3 (-) <TfO(-) <HSO4 (-) <Cl(-) <MsO(-) .
Thermodynamic quantities for the interaction of SO 4 2− with H + and Na + in aqueous solution from 150 to 320°C

The aqueous reactions, $$\begin{gathered} H^ + + SO_4^{2 - } = HSO_4^ - ,Na^ + + SO_4^{2 - } = NaSO_1^ - , \hfill \\ and H^ + + HSO_4^ - = H_2 SO_4 (aq) \hfill \\ \end{gathered} $$ were studied as a function of ionic strength(I) at 150, 175, 200, 250, 300 and 320°C using a flow calorimetric procedure. Log K, ΔH, ΔS and ΔC p values at I=0 were derived from the data at each temperature. Using these experimental values, equations describing log K, ΔH, ΔS and ΔC p at I=0 and temperatures from 150 to 320°C were derived for each system. The use of equations containing identical numbers of positive and identical numbers of negative charges on both sides of the equal sign (isocoulombic reaction principle) was evaluated as a technique for the extrapolation of log K values valid below 100°C to temperatures above 150°C. This evaluation indicated that the principle gives good estimates up to 320°C.
Analysis of anisotropic graphene platelet heat spreaders to reduce hot spot temperature and temperature non-uniformity

This work investigates the effect of thin film graphene heat spreaders on the maximum temperature of integrated electric circuits. An electronic chip with a 4 × 3mm footprint featured a centrally located 0.5 × 0.5mm hot spot located on the top wall. The remainder of the top wall was exposed to a uniform background heat flux. The graphene heat spreaders were applied to the top wall of an optimized cooling array of micro pin-fins having airfoil cross-sections. A fully 3D conjugate heat transfer analysis was performed to investigate the effects of different heat spreader thicknesses on the temperature of the hot spot and the temperature distribution on the hot surface. Both isotropic and anisotropic thermal conductivities of heat spreaders were considered. The conjugate heat transfer analysis also incorporated thermal contact resistance.
Computation of three-dimensional multiphase flow dynamics by Fully-Coupled Immersed Flow (FCIF) solver

Abstract This work presents a Fully-Coupled Immersed Flow (FCIF) solver for the three-dimensional simulation of fluid–fluid interaction by coupling two distinct flow solvers using an Immersed Boundary (IB) method. The FCIF solver captures dynamic interactions between two fluids with disparate flow properties, while retaining the desirable simplicity of non-boundary-conforming grids. For illustration, we couple an IB-based unsteady Reynolds Averaged Navier Stokes (uRANS) simulator with a depth-integrated (long-wave) solver for the application of slug development with turbulent gas and laminar liquid. We perform a series of validations including turbulent/laminar flows over prescribed wavy boundaries and freely-evolving viscous fluids. These confirm the effectiveness and accuracy of both one-way and two-way coupling in the FCIF solver. Finally, we present a simulation example of the evolution from a stratified turbulent/laminar flow through the initiation of a slug that nearly bridges the channel. The results show both the interfacial wave dynamics excited by the turbulent gas forcing and the influence of the liquid on the gas turbulence. These results demonstrate that the FCIF solver effectively captures the essential physics of gas–liquid interaction and can serve as a useful tool for the mechanistic study of slug generation in two-phase gas/liquid flows in channels and pipes.
The Oklahoma Meso-Scale Integrated Socio-Geographic Network: A Technical Overview

AbstractEstablished as a social companion to the Oklahoma Mesonet, the Oklahoma Meso-Scale Integrated Socio-Geographic Network (M-SISNet) is a network of approximately 1500 “social monitoring stations” (geolocated households) across the state of Oklahoma that provide data on household perceptions and responses to signals that are sent from agricultural, hydrological, and meteorological systems. This paper outlines the purpose and nature of the M-SISNet, with specific focus on the sample frame, protocols for recruitment, retention, and survey implementation. It concludes with example survey questions, analyses, and directions for accessing the data.
Methane hydrate formation in thick sand reservoirs: 1. Short-range methane diffusion

Abstract We show with a comprehensive hydrate formation model that diffusion of dissolved methane along the local concentration gradient alone cannot transport enough methane to form the concentrated methane hydrates in thick (>= several m) marine sand reservoirs. In this model, methane is generated locally by biodegradation of organic matter in mudstones and diffused into the bounding sandstone where the methane hydrate solubility decreases abruptly and hydrate precipitates from the extra methane in water. Hydrate formed by local diffusion has peak concentrations at the top and base of the sandstone, and it decreases sharply toward the center; salinity is slightly elevated relative to seawater, and its gradient is negligible across the sandstone and adjacent mudstones; dissolved methane concentration decreases from the mudstones to the sandstone. Overpressure is generated in the sediment due to reduction of sediment permeability and volume expansion when hydrate replaces pore water. There is a shallow zone where pore pressure converges toward the lithostatic pressure and fracturing is possible. This study provides further insights into hydrate formation by local diffusion of dissolved methane. In addition, the numerical model we developed in this study fully couples the hydrate-liquid capillary effect, dynamic pore size change, and transient pore pressure-dependent sediment compaction with the multiphase (gas, liquid and hydrate) flow and multicomponent (methane, water and salt) transport. Our model not only predicts pore pressure, but also incorporates the effect of hydrate formation on overpressure generation and subsequent dissipation. These modeling approaches are now at a level of sophistication that we can start to distinguish what physical processes, of the several proposed, are viable explanations for observed hydrate deposits.
Power/Performance Controlling Techniques in OpenPOWER

This paper presents the design and implementation of new power measurement and management features found in OpenPOWER systems, along with new techniques for increasing system performance in power constrained environments. The firmware and its ecosystem are open source to allow the community to extend the current capabilities.
Biochemistry of Enzymatic Pathogenicity Factors

Secreted proteinases, lipases, and glycosidases produced by the Eumycota are, by and large, components of a repertoire of exoenzymes which participate in absorptive nutrition. Such hydrolases are characterized by broad substrate specificities. Their secretion is induced by exposure of cells to specific nutritive compounds and modulated by physical factors that characterize the ecological niche in which the fungus proliferates. Certain exoenzymes have also been reported to alter the pH of the microenvironment, a secondary function which contributes to optimization of conditions for fungal growth and sporulation. Fungi that evolved as agents of superficial or deep-seated mycoses of mammals have encountered an abundance of proteins, such as keratin, elastin, collagen, albumin, hemoglobin, and immunoglobulins.
T7 Expression Systems for Inducible Production of Proteins from Cloned Genes in E. coli

Inducible T7 expression systems are capable of producing a wide range of proteins in E. coli. Improvements over common practice include: (1) preventing unintended induction by establishing and maintaining expression strains in non-inducing growth media composed entirely of purified components instead of complex growth media that may variably induce target proteins on approach to saturation; and (2) expressing many target proteins in parallel by convenient and productive auto-induction in BL21(DE3) and other suitable hosts, instead of IPTG induction. From the earliest days, basal expression prevented establishment of inducible strains for producing proteins that are stressful to the host. Newly developed pAL vectors now reduce basal expression to levels where coding sequences for even the most stressful proteins can be maintained and induced. Asymmetric ligation allows simple and efficient cloning of individual coding sequences or simultaneous cloning of two or three coding sequences for co-expression from a single pAL vector. © 2018 by John Wiley & Sons, Inc.
Inhibition of prolyl hydroxylases alters cell metabolism and reverses pre-existing diastolic dysfunction in mice

Abstract Background Diastolic dysfunction is emerging as a leading cause of heart failure in aging population. Induction of hypoxia tolerance and reprogrammed cell metabolism have emerged as novel therapeutic strategies for the treatment of cardiovascular diseases. Methods and results In the present study, we showed that deletion of sirtuin 3 (SIRT3) resulted in a diastolic dysfunction together with a significant increase in the expression of prolyl hydroxylases (PHD) 1 and 2. We further investigated the involvement of PHD in the development of diastolic dysfunction by treating the 12–14 months old mice with a PHD inhibitor, dimethyloxalylglycine (DMOG) for 2 weeks. DMOG treatment increased the expression of hypoxia-inducible factor (HIF)-1α in the endothelium of coronary arteries. This was accompanied by a significant improvement of coronary flow reserve and diastolic function. Inhibition of PHD altered endothelial metabolism by increasing glycolysis and reducing oxygen consumption. Most importantly, treatment with DMOG completely reversed the pre-existing diastolic dysfunction in the endothelial-specific SIRT3 deficient mice. Conclusions Our findings demonstrate that inhibition of PHD and reprogrammed cell metabolism can reverse the pre-existed diastolic dysfunction in SIRT3 deficient mice. Our study provides a potential therapeutic strategy of induction of hypoxia tolerance for patients with diastolic dysfunction associated with coronary microvascular dysfunction, especially in the aging population with reduced SIRT3.
Persistent Human Control in a Reservation-Based Autonomous Intersection Protocol

Widespread use of fully autonomous vehicles is near. However, the desire of human beings to maintain control of their vehicles – even limited control – is unlikely to ever go away. Several protocols (e.g., AIM, SemiAIM and H-AIM) have been developed to safely and efficiently manage reservation-based intersections with a mixture of fully autonomous, semi-autonomous and non-autonomous vehicles. However, these protocols do not incorporate the dynamic of a human maintaining control of a semi-autonomous vehicle when approaching and crossing an intersection. This chapter lays the foundation for the extensions required for human-control of semi-autonomous vehicles, the ultimate goal being a protocol that maintains the efficiency of a fully autonomous environment while allowing human control of vehicles when navigating an intersection. This chapter also proposes information feedback mechanisms for human response, such as displays that provide the intersection arrival time, goal velocity, lane maintaining assistance and other warnings. Additionally, it describes a synthetic environment that enables the testing of intersection protocols that support human interaction.
An Empirical Study of SSL Usage in Android Apps

SSL/TLS (Secure Socket Layer/Transport Layer Security) has been used as a de facto security protocol to protect users' sensitive information in Android apps, which often need to communicate with servers online to provide users with some of their functionalities and services. Since most Android users tend to be either unaware of or unable to understand the security protocol well, it is critically important to investigate if SSL/TLS is used properly and implemented correctly to protect users' sensitive information such as credentials. In this paper, we seek to shine some light into this important issue by studying the usage of the security protocol in 200 most popular Android apps downloaded from Google Play. We found out that only 4% of these apps are vulnerable to two well-known attacks against the protocol, and this shows huge improvement of SSL/TLS usage in Android apps when compared to the results from a study conducted in 2012, where 100% of Android apps under the study were vulnerable.
Atomic layer deposition of epitaxial ferroelectric barium titanate on Si(001) for electronic and photonic applications

Epitaxial barium titanate (BTO) thin films are grown on strontium titanate-buffered Si(001) using atomic layer deposition (ALD) at 225 °C. X-ray diffraction confirms compressive strain in BTO films after the low temperature growth for films as thick as 66 nm, with the BTO c-axis oriented in the out-of-plane direction. Postdeposition annealing above 650 °C leads to an in-plane c-axis orientation. Piezoresponse force microscopy was used to verify the ferroelectric switching behavior of ALD-grown films. Electrical and electro-optic measurements confirm BTO film ferroelectric behavior in out-of-plane and in-plane directions, respectively, at the micrometer scale.Epitaxial barium titanate (BTO) thin films are grown on strontium titanate-buffered Si(001) using atomic layer deposition (ALD) at 225 °C. X-ray diffraction confirms compressive strain in BTO films after the low temperature growth for films as thick as 66 nm, with the BTO c-axis oriented in the out-of-plane direction. Postdeposition annealing above 650 °C leads to an in-plane c-axis orientation. Piezoresponse force microscopy was used to verify the ferroelectric switching behavior of ALD-grown films. Electrical and electro-optic measurements confirm BTO film ferroelectric behavior in out-of-plane and in-plane directions, respectively, at the micrometer scale.
Stark Broadening of H β , H γ , and H δ : An Experimental Study

Stark-broadened ${\mathrm{H}}_{\ensuremath{\beta}}$, ${\mathrm{H}}_{\ensuremath{\gamma}}$, and ${\mathrm{H}}_{\ensuremath{\delta}}$ line profiles from a spatially uniform plasma column which was formed in a critically damped discharge tube were recorded with a rapid-scan spectrometer. A plasma temperature of \ensuremath{\sim}2 eV was inferred from both ${\mathrm{H}}_{\ensuremath{\beta}}$- and ${\mathrm{H}}_{\ensuremath{\gamma}}$-to-continuum ratios. Values of the electron density were determined to an estimated accuracy of better than \ifmmode\pm\else\textpm\fi{}2% by means of two multiple-pass laser interferometers operating at infrared and visible wavelengths. Systematic errors in recording and analyzing the line profiles are estimated to be less than \ifmmode\pm\else\textpm\fi{}1.5%. For interferometric values of the electron density in the range (1.3-8.5)\ifmmode\times\else\texttimes\fi{}${10}^{16}$ ${\mathrm{cm}}^{\ensuremath{-}3}$, the measured half-intensity widths of all the recorded ${\mathrm{H}}_{\ensuremath{\beta}}$ profiles agreed to within \ifmmode\pm\else\textpm\fi{}2% of the widths predicted by Stark-broadening theory. In this comparison, the \ifmmode\pm\else\textpm\fi{}2% represents the maximum scatter of the measured half-intensity widths where the theoretical widths were determined using the interferometric values of electron density which were taken as the standard. The total systematic error in this comparison is estimated to be less than \ifmmode\pm\else\textpm\fi{}3.5%. For ${\mathrm{H}}_{\ensuremath{\gamma}}$ the measured half-intensity widths ranged from 11 to 25% larger than that predicted by theory for electron densities in the range (1.3-7.1)\ifmmode\times\else\texttimes\fi{}${10}^{16}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. For ${\mathrm{H}}_{\ensuremath{\delta}}$ the measured half-intensity widths are 7% narrower than that predicted by theory for electron densities in the range (1.3-2.8)\ifmmode\times\else\texttimes\fi{}${10}^{16}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. Because the ${\mathrm{H}}_{\ensuremath{\beta}}$, ${\mathrm{H}}_{\ensuremath{\gamma}}$, and ${\mathrm{H}}_{\ensuremath{\delta}}$ profiles were recorded from the same plasma, systematic errors in measuring the electron density will affect the comparison of theory and experiment for each line in the same sense. Thus the relative systematic errors between the comparison of all three lines with the theory are estimated to be less than \ifmmode\pm\else\textpm\fi{}1.5%.
Adventures in English Syntax

For anyone who wants to become a more effective writer, a more perceptive reader, and a more precise thinker, an understanding of English sentence structure is indispensable. This book shows you how to begin. Using clear and engaging examples from English, it introduces the basic concepts of syntactic structure to readers with no background in linguistics. Starting with simple, familiar phrases, and progressing to more complex sentences, it builds on what we already intuitively know, to provide a step-by-step account of why we understand these examples as we do. It then shows how that understanding can be applied to writing, helping us to avoid some of the common hallmarks of 'bad writing', such as ambiguity, redundancy, and vagueness. A unique and valuable resource, this book will enrich your understanding of English in ways that will make you a more effective user of the language. Publisher's note: The e-book edition of this title, like the print editions, contains color. For those e-reader devices and applications that cannot display color, the color material is available in pdf format as an online resource: www.cambridge.org/Freidin
Significance of positive tracheal cultures in the 30 days following tracheostomy

Abstract Introduction Positive tracheal cultures obtained after tracheostomy are often considered organ/space surgical site infections by the National Surgical Quality Improvement Project. However, the definition of bacterial tracheitis after tracheostomy is not well described. Objective To determine the relationship of positive tracheal cultures in the 30 days following pediatric tracheostomy, antibiotic treatment of these cultures, and signs/symptoms of respiratory infection. Methods A retrospective chart review was performed on subjects who underwent tracheostomy from November 2012–September 2017 at a tertiary care pediatric center. The following data was studied: positive tracheal cultures, antibiotic treatment for positive cultures, and other signs/symptoms of infection including fever and elevated white blood cell count. Descriptive data analysis was performed, and relative risk and 95% confidence intervals were calculated. Multivariate logistic regression model was used to assess independent association when applicable. Results There were 173 subjects who met study criteria. Median age at tracheostomy was 4.6 months. Fifty-one percent (89/173) of subjects had at least one positive tracheal culture in the 30 days following tracheostomy. Of those subjects, 38% (34/89) had fever, 71% (32/45) had an elevated white blood cell count, 31% (22/72) had consolidation on chest imaging, 61% (54/89) had increased tracheal secretions, 70% (62/89) had increased ventilation requirements, and 60% (53/89) were treated with antibiotics for a diagnosis of tracheitis. There was no meaningful difference when comparing fever, increased white blood cell count, lung consolidation, increased tracheal secretions, or increased ventilation requirements in those with and without a positive tracheal culture or in those with and without antibiotic treatment for a positive culture. Multivariate logistic regression analysis showed that increased age at time of tracheostomy, more days on the ventilator after tracheostomy, and an increased number of positive cultures in the year after tracheostomy were related to having a positive tracheal culture within 30 days of tracheostomy. Conclusion For post-operative pediatric tracheostomy subjects, there were no meaningful differences when comparing signs/symptoms of infection between those with and without a positive tracheal culture and between those with and without antibiotic treatment for a positive culture.
Ensemble Dehazing Networks for Non-Homogeneous Haze

Image dehazing is one of the most challenging imaging inverse problems. Although deep learning methods produce compelling results, one of the most crucial practical challenge is that of non-homogeneous haze, which remains an open problem. To address this challenge, we propose 3 models that are inspired by ensemble techniques. First, we propose a DenseNet based single-encoder four-decoders structure denoted as EDN-3J, wherein among the four decoders, three of them output estimates of dehazed images (J 1 , J 2 , J 3 ) that are then weighted and combined via weight maps learned by the fourth decoder. In our second model called EDN-AT, the single-encoder four-decoders structure is maintained while three decoders are transformed to jointly estimate two physical inverse haze models that share a common transmission map t with two distinct ambient light maps (A 1 , A 2 ). The two inverse haze models are then weighted and combined for the final dehazed image. To endow two sub-models flexibility and to induce capability of modeling non-homogeneous haze, we apply attention masks to ambient lights. Both the weight maps and attention maps are generated from the fourth decoder. Finally, in contrast to the above two ensemble models, we propose an encoder-decoder-U-net structure called EDN-EDU, which is a sequential hierarchical ensemble of two different dehazing networks with different modeling capacities. Experiments performed on challenging benchmark image datasets of NTIRE'20 and NTIRE'19 demonstrate that the proposed models outperform many state-of-the-art methods and this fact is particularly demonstrated in the NTIRE-2020 contest where the EDN-AT model achieves the best result in the sense of the perceptual quality metric LPIPS.
Experimental investigation of ram accelerator flow fields and combustion kinetics

Ram accelerator-related research at Stanford in the areas of hypersonic reactive flows and high-pressure combustion kinetics is presented. Research on reactive flows includes investigation of the combustion modes observed in hypersonic reactive flows over blunt cylinders and 2D bodies. In the experiments reported herein, simultaneous OH PLIF and schlieren imaging experiments of hypersonic reactive flow fields around spherical-nosed and flat-faced cylinders, 19 and 25 mm in diameter, have been performed. Stagnation pressure histories were recorded using a pressure transducer embedded in the cylinders. Methane-, ethylene-, and hydrogen-based fuel-oxidizer mixtures were used at different free stream conditions. Three different combustion modes were observed as flow velocity was varied relative to the Chapman-Jouget speed, consistent with previous work. These experiments represent the first time pressure disturbances in the unsteady combustion modes have been directly measured. Gas-phase combustion kinetics research involves the use of a high-pressure shock tube facility for ignition delay time measurements and detailed kinetics modeling for ram accelerator mixtures and conditions. Ignition time measurements are presented, and a detailed kinetics mechanism developed to model CH4/O2 ram accelerator ignition is reviewed.
Walking test procedures influence speed measurements in individuals with chronic stroke.

BACKGROUND Walking speed measurements are clinically important, but varying test procedures may influence measurements and impair clinical utility. This study assessed the concurrent validity of walking speed in individuals with chronic stroke measured during the 10-m walk test with variations in 1) the presence of an electronic mat, 2) the speed measurement device, and 3) the measurement distance relative to the total test distance. METHODS Twenty-five individuals with chronic stroke performed walking tests at comfortable and maximal walking speeds under three conditions: 1) 10-m walk test (without electronic mat) measured by stopwatch, 2) 10-m walk test (partially over an electronic mat) measured by software, and 3) 10-m walk test (partially over an electronic mat) measured by stopwatch. Analyses of systematic bias, proportional bias, and absolute agreement were performed to determine concurrent validity between conditions. FINDINGS Walking speeds were not different between measurements (P ≥ 0.11), except maximal walking speed was faster when speed was measured with software vs. stopwatch (P = 0.002). Absolute agreement between measurements was excellent (ICC ≥ 0.97, P < 0.001). There was proportional bias between software vs. stopwatch (R2 ≥ 0.19, P ≤ 0.03) and between tests with vs. without the electronic mat (R2 = 0.27, P = 0.008). Comparisons between conditions revealed that walking speed and concurrent validity may be influenced by walking test distance, presence of an electronic mat, speed measurement device, and relative measurement distance. INTERPRETATION Walking test procedures influence walking speed and concurrent validity between measurements. Waking test procedures should be as similar as possible with normative data or between repeated measurements to optimize validity.
Oxidation weakens interfaces in carbon nanotube reinforced titanium nanocomposites: An in situ electron microscopy nanomechanical study

Abstract The interfacial binding interactions in fiber–reinforced metal matrix nanocomposites (MMNC) are involved with sophisticated physico-chemical​ phenomena that are sensitive to their commonly encountered high-temperature processing and/or working environments. The resulting interfacial load transfer characteristics, which play a vital role in achieving the anticipated bulk mechanical properties enhancements, remain elusive. Here we investigate the effect of thermal processing on the interfacial strength of carbon nanotube (CNT) reinforced titanium (Ti) nanocomposites by conducting in situ nanomechanical single-nanotube pull-out measurements inside a high resolution scanning electron microscope. Our nanomechanical measurements reveal that thermal annealing at 400 °C for two hours results in a 40% decrease of the interfacial load-carrying capacity. The measurements were analyzed using a micromechanics shear-lag model, and the results show that the thermal annealing reduces the maximum interfacial shear strength by about 42% from about 231MPa to about 135 MPa. The observed weakening of the CNT–Ti interface caused by thermal annealing is attributed to the formation of newly grown titanium oxide on the CNT–Ti binding interface. The findings reported here are useful to better understand the impact of thermal processing on the reinforcing efficiency of nanotubes in metal matrices, which is essential to the design and manufacturing of nanotube-reinforced MMNC with superior high-temperature performance.
Trust and Lending: An Experimental Study

This paper investigates the importance and the determinants of trust in a lending situation using a controlled experiment. We find that communication can facilitate collaboration between lenders and borrowers through three channels of trust: 1) an information channel, 2) a preference channel, and 3) a reciprocity channel. Our results highlight the role of trust in mitigating the moral hazard problem in lending.
Keratin 19 maintains E-cadherin localization at the cell surface and stabilizes cell-cell adhesion of MCF7 cells.

A cytoskeletal protein keratin 19 (K19) is highly expressed in breast cancer but its effects on breast cancer cell mechanics are unclear. In MCF7 cells where K19 expression is ablated, we found tha...
1003 – GENETIC STUDIES OF HUMAN HEMATOPOIESIS

In this talk, I will discuss work in our laboratory that has focused on using insights from human genetic variation found in healthy individuals and those impacted by disease to gain further insights into hematopoiesis. I will additionally discuss how we are developing genomic assays to functionally dissect the contributions of such variation to hematopoiesis in health and disease.
How Does Port Efficiency Affect Maritime Transport Costs and Trade? Evidence from Indian and Western Pacific Ocean Countries

Would improvements in port performance increase trade in countries on the Indian and Western Pacific Oceans? Previous studies attempted to answer this question using ad hoc measures of port efficiency that do not control for the actual use of port assets or measures that can be very noisy. To avoid these problems, this paper builds a measure of economic efficiency based on the use of port inputs to deliver port output. Using data envelop analysis, it ranks countries on the Indian and Western Pacific Oceans in terms of their port efficiency, and assesses the effect of increased efficiency. It finds that becoming as efficient as the country with the most efficient port sector would reduce their average maritime transport costs by up to 14 percent and increase their exports by up to 2.2 percent.
Computational approaches to detect small lesions in 18 F-FDG PET/CT scans.

PURPOSE When physicians interpret 18 F-FDG PET/CT scans, they rely on their subjective visual impression of the presence of small lesions, the criteria for which may vary among readers. Our investigation used physical phantom scans to evaluate whether image texture analysis metrics reliably correspond to visual criteria used to identify lesions and accurately differentiate background regions from sub-centimeter simulated lesions. METHODS Routinely collected quality assurance test data were processed retrospectively for 65 different 18 F-FDG PET scans performed of standardized phantoms on eight different PET/CT systems. Phantoms included 8-, 12-, 16-, and 25-mm diameter cylinders embedded in a cylindrical water bath, prepared with 2.5:1 activity-to-background ratio emulating typical whole-body PET protocols. Voxel values in cylinder regions and background regions were sampled to compute several classes of image metrics. Two experienced physicists, blinded to quantified image metrics and to each other's readings, independently graded cylinder visibility on a 5-level scale (0 = definitely not visible to 4 = definitely visible). RESULTS The three largest cylinders were visible in 100% of cases with a mean visibility score of 3.3 ± 1.2, while the smallest 8-mm cylinder was visible in 58% of cases with a significantly lower mean visibility score of 1.5±1.1 (P < 0.0001). By ROC analysis, the polynomial-fit signal-to-noise ratio was the most accurate at discriminating 8-mm cylinders from the background, with accuracy greater than visual detection (93% ± 2% versus 76% ± 4%, P = 0.0001), and better sensitivity (94% versus 58%, P < 0.0001). CONCLUSION Image texture analysis metrics are more sensitive than visual impressions for detecting sub-centimeter simulated lesions. Therefore, image texture analysis metrics are potentially clinically useful for 18 F-FDG PET/CT studies.
The basement membrane: substratum of histological order and complexity

It has only been since the second great war that we finally are building a solid morphological bridge between the world of the biophysicists, populated in part by giant molecules, and the worlds of the cytologists, histologists, and embryologists where cells are the dominant populations. In previous meetings we have had ample demonstration of the important and often key role of electron microscopy in developing our knowledge of some families of macromolecules. People associated at one time or another with F. O. Schmitt at the Massachusetts Institute of Technology particularly have advanced macromolecular knowledge in studying collagen, muscle, myelin, and the cell surface.
Agonist Properties of N,N-Dimethyltryptamine at Serotonin 5-HT2A and 5-HT2C Receptors

Abstract R. L. SMITH, H. CANTON, R. J. BARRETT AND E. SANDERS-BUSH. Agonist properties of N,N-Dimethyltryptamine at 5-HT2A and 5-HT2C receptors. PHARMACOL BIOCHEM BEHAV 61(3) 323–330, 1998.—Extensive behavioral and biochemical evidence suggests an agonist role at the 5-HT2A receptor, and perhaps the 5-HT2C receptor, in the mechanism of action of hallucinogenic drugs. However the published in vitro pharmacological properties of N,N-dimethyltryptamine (DMT), an hallucinogenic tryptamine analog, are not consistent with this hypothesis. We, therefore, undertook an extensive investigation into the properties of DMT at 5-HT2A and 5-HT2C receptors. In fibroblasts transfected with the 5-HT2A receptor or the 5-HT2C receptor, DMT activated the major intracellular signaling pathway (phosphoinositide hydrolysis) to an extent comparable to that produced by serotonin. Because drug efficacy changes with receptor density and cellular microenvironment, we also examined the properties of DMT in native preparations using a behavioral and biochemical approach. Rats were trained to discriminate an antagonist ketanserin from an agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) in a two-lever choice paradigm. Pharmacological studies showed that responding on the DOI and ketanserin lever reflected agonist and antagonist activity at 5-HT2A receptors, and hence, was a suitable model for evaluating the in vivo functional properties of DMT. Like other 5-HT2A receptor agonists, DMT substituted fully for DOI. Intact choroid plexus was used to evaluate the agonist properties at endogenous 5-HT2C receptors; DMT was a partial agonist at 5-HT2C receptors in this native preparation. Thus, we conclude that DMT behaves as an agonist at both 5-HT2A and 5-HT2A receptors. One difference was evident in that the 5-HT2C, but not the 5-HT2A, receptor showed a profound desensitization to DMT over time. This difference is interesting in light of the recent report that the hallucinogenic activity of DMT does not tolerate in humans and suggests the 5-HT2C receptor plays a less prominent role in the action of DMT.
Bayesian Updating for General Maxmin Expected Utility Preferences

A characterization of “generalized Bayesian updating” in a maxmin expected utility setting is provided. The key axioms are consequentialism and constant-act dynamic consistency. The latter requires that, if an arbitrary act f is preferred (inferior) to a constant act y conditional upon E, and if f dominates (is dominated by) y pointwise on the complementary event Ec, then f is unconditionally preferred (inferior) to y. The result provides a basis for a model of dynamic choice that accommodates arbitrary unconditional maxmin EU preferences, and allows for deviations from full dynamic consistency related to ambiguity. Standard Expected Utility (EU) preferences are separable across events. In a static setting, the notion of separability is formalized by Savage’s Postulate P2 (the “Sure-Thing Principle”). In a dynamic framework, separability corresponds to dynamic consistency: if the decision maker would prefer some course of action to another if she learned that some event has obtained, and also if she learned that the same event has not obtained, then she should prefer it even prior to learning whether or not the event in question has obtained. As is well-known, P2 and dynamic consistency are closely related (see e.g. Ghirardato, 2001). In a static setting, Ellsberg (1961) demonstrates that separability may fail if the decision maker perceives some ambiguity in the relative likelihood of events. Thus, in a dynamic setting, it is at least plausible to expect some tension between ambiguity and dynamic consistency. Recent experimental evidence (Cohen et al., 2000) based on a dynamic version of the single-urn Ellsberg example seems to indicate that ambiguity may indeed lead to violations of dynamic consistency.
Superlinear Speedup in Parallel State-Space Search

When N processors perform depth-first search on disjoint parts of a state space tree to find a solution, the speedup can be superlinear (i.e., > N) or sublinear (i.e., <N) depending upon when a solution is first encountered in the space by one of the processors. It may appear that on the average, the speedup would be either linear or sublinear. Using an analytical model, we show that if the search space has more than one solution and if these solutions are randomly distributed in a relatively small region of the search space, then the average speedup in parallel depth-first search can be superlinear. If all the solutions (one or more) are uniformly distributed over the whole search space, then the average speedup is linear. This model is validated by our experiments on synthetic state-space trees and the 15-puzzle problem. The same model predicts average superlinear speedup in parallel best-first branch-and-bound algorithms on suitable problems.
Watershed‐scale effects of urbanization on sediment export: Assessment and policy

[1] Built components of watersheds are associated with impervious surfaces that alter hydrology, disrupt ecosystems, and affect water quality. This study focuses on the impervious factor as a tool for assessment and policy design to address water quality impacts. The empirical model uses a combination of watershed simulation and statistical regression modeling to study sediment loading at various stages of urbanization. The policy design is based on private behavior in a watershed setting to develop appropriate economic approaches. The incentives through taxes, subsidies, and cost sharing are based on water quality impacts. It was observed that nonlinearity in response functions resulted in transition effects that are continuous. This is due to gradual shifts in landscape characteristics as a result of urbanization. On a regional basis, impervious factor had a varying effect on water quality and depend on the state of urbanization and spatial characteristics. Economic policies based on a metric like impervious cover can be used to mitigate the negative effects of urbanization in watersheds through use of appropriate BMPs, urban forestry methods, and spatial targeting. While linear rules in policy are easier to implement, nonlinear rules were more effective in representing the changes in marginal social cost of impervious factor, especially initial and late stages of urbanization. There exists excellent scope in using this targeted policy to address specific problems associated with complex urban systems.
An Analysis by Selection and Crossing, of Genetic Factors Involved in Defective Venation, a Variable Character of the Parasitic Wasp, HABROBRACON JUGLANDIS (Ashmead).

Page 92, line 16, for "1901" read "1921." Table 4, facing page 104, top of "parents" column for "Stock14 ♀ ♀ × stock 3 ♂♂" read "stock 3 ♀♀ × stock 14
Engineering effective intervention: measuring reaction, learning, behavior and results

Summary form only given. Four years of undergraduate engineering education is not a panacea of success for engineers. Evidence suggests that most engineers need to learn the art of management when they have become successful as engineers but poor as managers of people; and must move on as more successful managers of technology and people. But, such characteristics must be developed by programming and intervention and by tapping into the hidden (latent) potential of engineers as they work on the job. These management development programs must be measured as effective interventions from four desirable aspects: (i) reaction to the intervention, (ii) knowledge gained for immediate concept simulated analysis and use, (iii) change of behavior in making appropriate decisions, and finally (iv) the impact on subordinates (manager once removed) due to the program effect reflected in the job performance, and the consequent impact on the employing organization. This research discusses the merits of an educational program evaluation with dependable results using reaction to, learning at, behavior after, and results of the educational intervention.
Principle design of 300 KHz meco RF kicker bipolar solid state modulator

A high speed, high repetition rate, bipolar solid-state high voltage modulator is under development at Brookhaven National Laboratory for muon electron conversion (MECO) experiment. The modulator will be used to drive a RF kicker consisting of a pair of parallel deflecting plates. The principle design is based on the inductive-adder topology. This system requires a fast pulse rise and fall time of approximately 20 ns, a pulse width of 100ns, a pulse repetition rate of 300 kHz, and a 60 kHz sinewave amplitude modulation. Fast high voltage MOSFETs are used as main switching devices. Different magnetic materials are being investigated for the adder core magnets. The main circuit design, critical subsystems, and major technical issues will be discussed. The circuit simulation, component selection and evaluation, and preliminary test results will be presented
Illusory correlations in perceptions and predictions of organizational traits

People often believe in 'illusory' correlations between variables that are similar, but not actually correlated. This study suggests that judgements of organizational traits reflect illusory correlations, because subject’ perceptions of correlations between traits, and the predictions of Hage’s (1965) ‘axiomatic’ theory, were more highly correlated with independent similarity ratings than with actual correlations between traits. Some methodological reasons why organizational-trait theories might unwittingly produce illusory correlation predictions are discussed, along with possible remedies.
Presynaptic modulation by eicosanoids in cortical synaptosomes.

In continuing experiments to determine the ionic basis of inhibitory presynaptic modulation, rat cortical synaptosomes were employed and receptor-activated K+ efflux was determined with a K+ sensitive electrode. When synaptosomes were sub-optimally depolarized by veratridine, the addition of agents that activated purinergic, α2, muscarinic and opioid receptors all promoted K+ efflux. With 2-chloroadenosine as a model inhibitory presynaptic modulator, the increased K+ efflux evoked by this agent was blocked by the cyclooxygenase inhibitor indomethacin suggesting that arachidonic acid or its metabolites was an intermediary in opening the channel. When arachidonic acid and PGE2 were tested, both promoted K+ efflux that was inhibited by dendrotoxin and mast cell degranulating peptide, two agents that are known to inhibit a delayed rectifier K+ current. Our results suggest that via eicosanoid second messengers, inhibitory presynaptic modulators open a sub-class of K channels that hyperpolarize nerve terminals, therefore less Ca2+ would enter per nerve impulse and thus the evoked release of neurotransmitters would be decreased.
Carbon dioxide urethral pressure profiles in males

Carbon dioxide urethral pressure profiles were obtained in a group of continent and incontinent male patients. Cystometry, needle electromyography of the striated urinary sphincter, and cystourethroscopy were also performed in most patients. A characteristic reproducible urethral pressure profile can be obtained in the continent, obstructed, and incontinent groups. The results also showed that the urethral pressure profile is influenced by the activity of the periurethral striated muscle. The urethral profile when performed with other established urodynamic procedures is a useful test in delineating normal and abnormal urinary sphincter function.
Context and Coalition-Bargaining Comparing Portfolio Allocation in Eastern and Western Europe

Eastern European countries have adopted parliamentary institutions that resemble those in the West. This enables researchers to evaluate the effects of institutions in contrasting contexts. In this...
Functional instability of T7 early mRNA

IT has been known for some time that mRNA of bacteriophage T7 is stable. Summers1 measured the decay of acid-insoluble radioactivity in the mRNA after new synthesis was stopped with actinomycin in T7-infected, actinomycin-permcable Escherichia coli cells. The halflife of T7 mRNA was estimated greater than 25–30 min at 30° C compared with about 2.5 min for E. coli mRNA. Marrs and Yanofsky2 showed that the mRNA transcribed from the tryptophan operon is degraded normally in T7-infected E. coli but T7 mRNA is stable, measured by hybridisation with T7 DNA. In these experiments only chemical stability of T7 mRNA was studied in terms of acid-insoluble amount or DNA-hybridisable amount and no information was obtained on the functional integrity of the mRNA.
On the complexity of solving feasible systems of linear inequalities specified with approximate data

An algorithm that gives an approximate solution of a desired accuracy to a system of linear inequalities specified with approximate data is presented. It uses knowledge that the actual instance is feasible to reduce the data precision necessary to give an approximate solution to the actual instance. In some cases, this additional information allows problem instances that are ill-posed without the knowledge of feasibility to be solved. The algorithm is computationally efficient and requires not much more data accuracy than the minimal amount necessary to give an approximate solution of the desired accuracy. This work aids in the development of a computational complexity theory that uses approximate data and knowledge.
New exploratory and confirmatory factor analysis insights into the community of inquiry survey

Abstract This study has the aim of investigating the factor structure of an adapted version of the Community of Inquiry survey developed by Arbaugh et al. (2008). For this purpose, both exploratory and confirmatory analyses were employed in addition to a parallel analysis using two different samples. The results indicated a three-factor structure as well as high reliability indices for each subpart of the survey. More specifically, the three factors identified appear to correspond to three presences: teaching, cognitive, and social presences. Moreover, results of the study did not reveal any substantial changes that need to be made to any survey items. All these align completely with the theoretical assumptions of the Community of Inquiry Framework (e.g., Garrison & Akyol, 2013a, b), and call for further factor analytic studies on the survey.
Efficiency and adverse selection

Abstract Ex-ante and interim constrained efficiency of market equilibria with adverse selection is studied. With a continuum of qualities, allocations which are attainable (i.e., feasible, incentive compatible, and individually rational) are convex combinations of one-step allocations (named for the fact that an agent's consumption is a single stepped function of quality). This makes possible a simple geometric treatment of efficiency. Competitive equilibrium is efficient if the distribution of quality is not too convex. Wilson's (Bell J. Econ. 11 (1980), 108–130) buyer's equilibrium is generically unique and efficient. An efficient Wilson's seller's equilibrium always exists.