cssi/SciSciGPT-SciSciNet huggingface dataset:
Optimized Gated Detection for Lifetime Measurement over a Wide Range of Single Exponential Decays

Optimal estimation parameters are determined for the rapid lifetime determination technique (RLD) of fitting an exponential model to luminescence decay data that exhibit a wide range of lifetimes. Optimization of the lifetime estimate by this technique depends on only two parameters—period of integration and separation between the periods of integration. Luminescence quenching experiments produce a range of decay lifetimes. Selection of a fixed set of measuring parameters to determine lifetime throughout the entire range can simplify instrumentation and result in enhanced computation speed. The measuring parameters must be optimized to yield the best estimation of each lifetime in the range. The errors in measured lifetime for the RLD technique are investigated for a wide range of luminescence decays. Optimal separation and periods of integration for the modified RLD technique are found by modeling a set of simulated decay data with different lifetimes. Results from the simulation are then compared to similar measurements of oxygen-quenched luminescence decay. Agreement between simulation and quenching data is good.
Position 3 analogues of a crustacean pigment-dispersing hormone: Synthesis and biological activity☆

In an effort to explain the difference in potencies between the two characterized crustacean pigment-dispersing hormones (alpha-PDH; beta-PDH) and to define a role for residue 3 in these octadecapeptide hormones, we have synthesized and purified seven position 3 alpha-PDH analogues ([Ala3], [Ile3], [Asn3], [Gln3], [Asp3], [Glu3], and [Lys3]alpha-PDH). When tested for melanophore pigment-dispersing activity in destalked Uca, [Glu3]alpha-PDH was found to be 325% more potent than alpha-PDH. Reduced potencies were observed for the [Asp3] (58%), [Asn3] (26%), [Gln3] (11%), and [Ala3] (8%) derivatives. Much lower potencies were displayed by the [Lys3] and [Ile3] analogues (0.73% and 0.66%, respectively). These results suggest that the position 3 side chain carboxylate anion of [Glu3]alpha-PDH stabilizes the active receptor-bound conformer through a charge-charge interaction.
Epoxidation of Bacterial Polyesters with Unsaturated Side Chains. I. Production and Epoxidation of Polyesters from 10-Undecenoic Acid

Poly(3-hydroxyoctanoate-co-3-hydroxy-10-undecenoate)s (PHOUs) with controlled amounts of unsaturated side chains were produced by Pseudomonas oleovorans from various mixtures of 10-undecenoic acid ...
On the metatheoretical relativism of analyses of metatheoretical analyses: A critique of Kendler's comments☆

Abstract Because of its import for theory and method, developmental psychologists, over the past three decades, have discussed the philosophical bases of their discipline and/or evaluated the adequacy of others' discussions. T. S. Kendler's 1986 Developmental Review, 6, 80–95 commentary on our article (R. M. Lerner & M. B. Kauffman 1985 Developmental Review, 5, 309–333) is an instance of the latter type of paper. Kendler's evaluation is flawed because it (1) provides an undocumented and superficial analysis of the integration of organismic and contextualist ideas described in Lerner and Kauffman; (2) conflates ideas associated with separate world views; (3) confuses the superordinate nature of a world view with specific instances of this class of ideas; (4) confuses issues of description with issues of explanation; and (5) presents inaccurate, inadequately justified, and contradictory claims for the use of the mechanistic model. However, Kendler's paper is a good illustration of the idea that how one treats the adequacy of others' discussions of metatheoretical issues depends on, or is relative to, one's own metatheory and the recognition of this relativism.
Application of PIXE to the study of Renaissance style enamelled gold jewelry

Abstract This study examines and compares three pieces of Renaissance style gold and enamelled jewelry owned by the Walters Art Gallery, Baltimore, MD, USA. These are a 16th century Hat Badge of Adam and Eve, a 19th century Fortitude Pendant and a Diana Pendant presumed to be of the 16th century (The Walters Art Gallery, Jewelry, Ancient to Modern (Viking, New York, 1979)), Ref. [1]. PIXE spectroscopy was applied to examine the elemental composition of the gold and of the enamels. Compositional differences, including the use of post-Renaissance colorants, were found between the enamels in separate regions of each of the three pieces. The modern colorant, chromium, was, in fact, found in all of the pieces and uranium was found in only the Diana Pendant. There are some differences in the gold purity of the three objects; there are significant differences in the solders used even within one object, the Fortitude Pendant.
The Status of the Northern Population of the Copper-Bellied Watersnake, Nerodia erythrogaster neglecta

Abstract The Nerodia erythrogaster neglecta (Copper-bellied Watersnake) population north of 40 degrees north latitude is categorized as threatened under the US Endangered Species Act. Previous efforts to use mark-recapture to estimate population size have been unsuccessful because there were so few initial captures. We therefore evaluated the status of the largest presumed subpopulation of this population by using strip transects to provide a conservative (maximum) estimate of density and population size of adults. Our results indicate that the largest presumed adult Copper-bellied Watersnake metapopulation north of 40 degrees north latitude is extremely small, with a total size of 94 ± 22 adults, and is characterized by a population density of 1.17 ± 0.27 adult snakes/ha (95 % CI = 0.73–1.87 snake/ha). This Copper-bellied Watersnake population appears to be in danger of extirpation within the foreseeable future. Recovery will require protecting existing wetland complexes and restoring wetlands and the su...
Epiluminescence microscopy features of cutaneous malignant melanoma metastases.

Especially small and/or initial cutaneous malignant melanoma metastases (CMMMs) are tumours with inconspicuous clinical and sometimes histological features which may be difficult to differentiate from benign melanocytic lesions or angiomas. Thus it would be very valuable to have additional criteria for the differential diagnosis of such lesions. Thirty histologically verified CMMMs were examined using epiluminescence microscopy (ELM) in order to visualize a large number of morphological features permitting the recognition of malignancy. One hundred primary cutaneous malignant melanomas (PCMMs), 50 dysplastic naevi, 50 common naevi, 30 blue naevi and 20 haemangiomas served as the control group; these were randomly selected from a large data base and were all reviewed for histological diagnosis. Four of the 24 features studied were shown to differ significantly between CMMMs and the control group. Two features of the malignant tumour group (CMMM and PCMM) differed significantly from the benign tumour group. A polymorphic angiectatic base pattern and/or vascular aneurysms, peripheral erythema, brown-grey coloration as a negative criterion (i.e. its absence is indicative of CMMM) and a light brown halo had a specificity of 86.7-96.0% for CMMM. Areas of polymorphic and/or horizontally dilated capillaries and a saccular pattern had a specificity of 97.3-99.2% for the malignant group (CMMM and PCMM). Three features - peripheral greyish patches, lesions surrounded by grey streaks (melanoma cell infarcts of the vessels) and microscopic ovoid blood lakes (spontaneous microhaemorrhages)--were absent in the benign group. The prevalence of distinct ELM criteria in CMMM represents a useful enhancement for the diagnosis of malignancy in melanocytic skin lesions.
Substrate rescue of DNA polymerase β containing a catastrophic L22P mutation.

DNA polymerase (pol) β is a multidomain enzyme with two enzymatic activities that plays a central role in the overlapping base excision repair and single-strand break repair pathways. The high frequency of pol β variants identified in tumor-derived tissues suggests a possible role in the progression of cancer, making the determination of the functional consequences of these variants of interest. Pol β containing a proline substitution for leucine 22 in the lyase domain (LD), identified in gastric tumors, has been reported to exhibit severe impairment of both lyase and polymerase activities. Nuclear magnetic resonance (NMR) spectroscopic evaluations of both pol β and the isolated LD containing the L22P mutation demonstrate destabilization sufficient to result in LD-selective unfolding with minimal structural perturbations to the polymerase domain. Unexpectedly, addition of single-stranded or hairpin DNA resulted in partial refolding of the mutated lyase domain, both in isolation and for the full-length enz...
Imaging and estimating the surface heterogeneity on a droplet containing cosolvents.

Cosolvents have numerous applications in many industries as well as scientific research. The shortage in the knowledge of the structures in a cosolvent system is significant. In this work, we display the spatial as well as the kinetic distribution of the cosolvents using droplets as paradigms. When an alcohol/water-containing sessile droplet evaporates on a substrate, it phase segregates into a water-enriched core and a thin alcohol prevailing shell. This is considered to be due to the different escaping rate of solvents out of the liquid−vapor (l−v) interfaces. In between the core and shell phases, there exists a rough and solid-like liquid−liquid (l−l) wall interface as marked by the fluorescent polystyrene spheres and imaged by a confocal microscope. Holes and patches of beads are observed to form on this phase boundary. The water-dispersed beads prefer to partition within the core. The shell prevails in the droplet during most of the drying and shrinks with the l−v boundary. By monitoring the morpholo...
Ground calibrations of the Clouds and the Earth's Radiant Energy System (CERES) instrument for the tropical rainfall measuring mission (TRMM)

Clouds and the Earth's radiation energy system (CERES), a key experiment in the Earth observing system (EOS), is designed to measure the reflected shortwave and the emitted longwave radiances from Earth and its atmosphere. The CERES instrument consists of a scanning thermistor bolometer package with built in flight calibration systems. The first CERES instrument is scheduled for launch in 1997 aboard the joint National Aeronautics and Space Administration (NASA) and Japanese National Space Development Agency (NASDA) tropical rainfall measuring mission (TRMM) spacecraft. The laboratory calibrations of the instrument were conducted in the TRW vacuum facilities which are equipped with blackbodies, a cryogenically cooled transfer active-cavity radiometer, shortwave reference source, solar simulator and a constant radiance reference source. This paper describes the calibration facility and the calibration procedures for the CERES instrument.
Effects of the order of addition of reagents and alkali on modification of wheat starches

The objective of this research was to determine if adding reactive reagents to wheat starch granules before addition of alkali (the TRF method) would produce products that are different than those obtained with the conventional procedure (adding alkali before addition of reagent). Laboratory-isolated (LI) and commercial (C) normal (NWS) and waxy (WWS) wheat starches were each reacted with 6 reagents (acetic-adipic mixed anhydride (AAMA), phosphoryl chloride (POCl3), sodium trimetaphosphate (STMP), acetic anhydride (AA), succinic anhydride (SA), octenylsuccinic anhydride (OSA)). Data obtained were similar to those previously obtained with maize starches (Sui, Huber, & BeMiller, 2013). Almost no starch polymer molecule modification occurred when the TRF method and AAMA or AA were used; less than a third as much reaction when SA was the reagent used, and about the same amount of reaction when POCl3, STMP, or OSA were the reagents used (for different reasons).
An MRI-Compatible Probe Exchanger for Early Diagnosis and Treatment of Breast Cancer

The objective of this project is to develop a device to exchange interventional probes such as biopsy needles, local anesthesia, ablation tools, and lesion removal devices to perform multiple procedures for breast cancer diagnosis and treatment during single session in the MR scanner. Used as a supplement to an existing five degree-of-freedom (DOF) interventional probe positioning device, the apparatus is fitted with two additional DOF for the selection and exchange of interventional probes to be used in an automated probe positioning device. The entire system is constructed of MR compatible materials, i.e. non-magnetic and non-conductive, to eliminate artifacts and distortion of the MR images. The apparatus is remotely controlled by means of ultrasonic piezoelectric motors and a graphical user interface, providing MRI-guided planning and monitoring of the procedure while it is in progress. Based on a timing analysis, the device can quickly exchange a probe (48 seconds), thereby reducing the complexity and cost of the overall procedure.Copyright © 2004 by ASME
Lamb wave dispersion under finite plastic deformation

This paper presents a preliminary study of the effects residual plastic strains have on Lamb wave velocities and time of flight measurements. The potential application of this research is non-destructive evaluation and structural health monitoring, particularly reconstructing plastic strain fields. The finite deformation of a semi-infinite plate due to residual plastic strain is used to accommodate the changes in plate thickness and elongation. The results show that the S0 mode exhibits significant variations in group velocity in the highly dispersive regions, as much as a 2% increase in velocity with a 1% plastic strain. However, for time of flight measurements, the plate elongation had an order of magnitude effect rather than showing velocity changes. By exploiting time delay measurements, it may be possible to use wave speed measurements to determine plastic zones through Lamb-like waves.
US market entry processes of emerging multinationals: A case of Indian pharmaceuticals

This paper examines the foreign market entry strategies used by Indian pharmaceuticals to enter the United States. We use Dunning’s eclectic theory and its extensions to develop an understanding of how firm-specific and location-specific advantages are combined to exploit (e.g., sales in the US) and augment (e.g., access to RD Indian pharmaceuticals continually reassess their entry strategy and consider it within a wider combination of simultaneous strategies. For example, exporting a generic drug formulation into the US after a legal battle with an incumbent competitor does not inhibit acquisitions in complimentary drug markets, or preclude present or future research partnerships with that same incumbent company. The pursuit of multiple strategies at the same time allows developing country multinationals to succeed in the United States as latecomers compared to other generic manufacturers, domestic and foreign, who have their operations for a much longer period of time.
Geometrically exact displacement-based shell theory

Abstract The deformed geometry often is the most important information for applications of highly flexible plates/shells, and a geometrically exact shell theory should be displacement-based in order to directly and exactly describe any greatly deformed geometry. The main challenges of modeling a shell undergoing large deformation are how to describe its deformed reference plane and its differential element's large rotations and how to derive objective strains in terms of global displacements and rotations that contain both elastic straining and rigid-body movement. This paper presents a truly geometrically exact displacement-based shell theory without singularity problems. The theory fully accounts for geometric nonlinearities, all possible initial curvatures, and extensionality by using Jaumann strains and stresses, exact coordinate transformation, and orthogonal virtual rotations. Moreover, transverse shear deformations are accounted for by using a high-order shear deformation theory. The derived fully nonlinear strain–displacement relations enable geometrically exact forward analysis (obtaining the deformed geometry under a set of known loads) and inverse analysis (obtaining the required loads for a desired deformed geometry). Several numerical examples are used to demonstrate the accuracy and capabilities of the geometrically exact shell theory. Moreover, different theoretical and numerical problems of other geometrically nonlinear shell theories are shown to be mainly caused by the use of Mindlin plate theory to account for transverse shears, Green–Lagrange strains to account for geometric nonlinearities, and/or Euler and Rodrigues parameters to model large rotations.
Reaction paths and free energy profiles for conformational transitions: An internal coordinate approach

A new approach is proposed for the determination of transition states and reaction paths for conformational transitions. The method makes use of adiabatic energy surfaces in the space of ‘‘essential’’ degrees of freedom of the molecule. The reduced dimensionality of this space, compared to the full Cartesian space, offers improved computational efficiency and should allow determination of exact reaction paths in systems much larger than those currently amenable to study in Cartesian space. A procedure to obtain reaction paths and free energy profiles in solution is also proposed. The free energy profile along the path in solution is calculated utilizing a free energy perturbation method with constrains and perturbations in internal coordinate space. Applications to a conformational transition of the alanine dipeptide and the folding transition of a model reverse turn in water are presented. For the reverse turn, the sequential flip of dihedral angles reported by Czerminsky and Elber on a similar peptide [...
Hyperspectral Cloud and Aerosol Optical and Radiative Properties Modeling and Applications

This paper reports on the simulations of the hyperspectral radiative signatures of ice clouds and aerosols. Additionally, the numerical accuracy of a newly developed fast cloudy radiative transfer model is assessed.
Density and O-density of Beurling generalized integers

Let π(x) and N(x) be the respective counting functions of a set of generalized primes and a set of generalized integers in Beurling's sense. We consider weak conditions on π(x) some of which yield N(x) ∼ cx for some positive c, and some of which yield nontrivial O-estimates for N(x)x.
Intergrowth of Two Different Layered Networks in the Metallic Copper Oxyselenide Na1.9Cu2Se2·Cu2O

Solid-state oxy-chalcogenides of the late transition metals are rare. One reason for this may be the relative low oxophilicity and high chalcophilicity of these metals. An oxy-chalcogenide is defined as a compound with metal-oxide and metal-chalcogen bonds but no direct O-Q (Q = S, Te) bonds. Even though numerous copper chalcogenides and copper oxides exist, not mixed copper oxychalcogenides have been reported. Since these material display interesting electronic properties (e.g., metallic and charge density wave properties in chalogenides and high T[sub c] superconductivity in oxides), it is intriguing to consider the potential properties of mixed compounds. During this investigation of the reactivity of Cu with varous polychalcogenide fluxes such as Na[sub 2]-Se[sub x] the authors isolated an unusual new compound Na[sub 1.9]Cu[sub 2]-Se[sub 2][sm bullet]Cu[sub 2]O (I) with unprecendented mixed Cu-Se/Cu-O features. This is the first layered oxyselenide and is composed of two alternating, independent Cu/Se and Cu/O frameworks. The synthesis, structure, and charge-transport properties of this new material are reported herein. 14 refs., 3 figs.
Convergence properties of local solutions of sequences of mathematical programming problems in general spaces

This paper gives several sets of sufficient conditions that alocal solutionx k exists of the problem $$\min _{R^k } f^k (x)$$ ,k=1, 2,..., such that {x k } has cluster points that arelocal solutions of a problem of the form min R f(x). The results are based on a well-known concept of topological, orpoint-wise convergence of the sets {R k } toR. Such results have been used to construct and validate large classes of mathematical programming methods based on successive approximations of the problem functions. They are also directly applicable to parametric and sensitivity analysis and provide additional characterizations of optimality for large classes of nonlinear programming problems.
Generic properties of Mn spinels with an immiscibility induced by a Jahn-Teller distortion

The generic properties are scrutinized in Mn spinels with an immiscibility induced by a Jahn-Teller distortion through the CoFe(2-x)Mn(x)O(4) system. The x-ray diffraction experiment reveals that the immiscibility occurs at 1.1<x<2.0 and the relevant kinetics becomes faster with x. The temperature of the Jahn-Teller transition, which accompanies a sharp resistivity anomaly and matches the immiscibility gap boundary, increases with increasing x. The evolution of the magnetic and structural properties with various thermal treatments is studied carefully in this paper. Based on our comprehensive results, we have constructed a phase diagram of CoFe(2-x)Mn(x)O(4).
Impact of re-coarctation following the Norwood operation on survival in the balloon angioplasty era.

OBJECTIVES The objective of this study was to determine the efficacy of balloon angioplasty (BA) by comparing the immediate and long-term outcomes of patients with and without re-coarctation after a Norwood procedure. BACKGROUND Although BA has become the standard means for treating recurrent coarctation following a Norwood operation, it has been suggested that re-coarctation remains a significant cause of morbidity and mortality. METHODS Patients who survived a Norwood operation from December 1986 through June 2001 were studied. Differences between groups were evaluated by t test and logistic regression. Survival differences were tested by log-rank tests using Kaplan-Meier survival curves. RESULTS Fifty-eight of 633 patients underwent treatment for re-coarctation (9.2%). Thirty-five patients underwent BA (before 1988, 23 had surgery). Median age at catheterization was 6.6 months (1.9 to 35.6 months). Balloon angioplasty was successful (gradient <10 mm Hg) in 32 of 35 patients (92%). There were no BA-related deaths or neurologic complications. Recurrent obstruction after BA occurred in seven patients (20%); five underwent re-dilation. Kaplan-Meier estimates of freedom from recurrent obstruction after initial BA were 97% at one month, 79% at one year, and 79% at five years. There were no differences in survival between patients with re-coarctation treated by BA and patients who did not undergo treatment for re-coarctation. CONCLUSIONS We found that 9.2% of patients underwent treatment for re-coarctation following a Norwood operation. Balloon angioplasty is effective, with low morbidity, no early mortality, and no difference in long-term survival when compared with patients who did not have re-coarctation. Recurrent coarctation following BA occurred in 17% of patients, usually within the first year after BA.
A novel angiogenesis inhibitor suppresses rat adjuvant arthritis

Rat adjuvant arthritis (AA) is an animal model of rheumatoid arthritis in which pannus formation and destruction of joints occur after immunization with complete Freund's adjuvant. Neovascularization is present within the synovium and may be critical for pannus growth. In this study the effects of a novel angiogenesis inhibitor, AGM-1470, on AA were evaluated. Lewis rats were immunized with CFA to induce arthritis. AGM-1470 treatment was initiated prior to arthritis onset (preventative protocol) or administered to rats with established disease (suppressive protocol). The severity of synovitis and the immunologic status of all rats were then evaluated. Using clinical and radiographic criteria, AGM-1470 significantly reduced arthritis incidence (preventative protocol) (P < 0.01) and disease severity (both protocols, P < 0.001, compared to controls) without affecting T cell function in vitro or phenotype in vivo. Additionally, histologic sections from control rats revealed marked pannus formation, destruction of bone/cartilage, and neovascularization. These findings were absent in AGM-1470-treated rats. AGM-1470 may offer a new treatment option for rheumatoid arthritis and other angiogenesis-dependent diseases.
Pericytes and perivascular fibroblasts are the primary source of collagen-producing cells in obstructive fibrosis of the kidney.

Understanding the origin of scar-producing myofibroblasts is vital in discerning the mechanisms by which fibrosis develops in response to inflammatory injury. Using a transgenic reporter mouse model expressing enhanced green fluorescent protein (GFP) under the regulation of the collagen type I, α 1 (coll1a1) promoter and enhancers, we examined the origins of coll1a1-producing cells in the kidney. Here we show that in normal kidney, both podocytes and pericytes generate coll1a1 transcripts as detected by enhanced GFP, and that in fibrotic kidney, coll1a1-GFP expression accurately identifies myofibroblasts. To determine the contribution of circulating immune cells directly to scar production, wild-type mice, chimeric with bone marrow from coll-GFP mice, underwent ureteral obstruction to induce fibrosis. Histological examination of kidneys from these mice showed recruitment of small numbers of fibrocytes to the fibrotic kidney, but these fibrocytes made no significant contribution to interstitial fibrosis. Instead, using kinetic modeling and time course microscopy, we identified coll1a1-GFP-expressing pericytes as the major source of interstitial myofibroblasts in the fibrotic kidney. Our studies suggest that either vascular injury or vascular factors are the most likely triggers for pericyte migration and differentiation into myofibroblasts. Therefore, our results serve to refocus fibrosis research to injury of the vasculature rather than injury to the epithelium.
The need for quantitative methods in syntax and semantics research

The prevalent method in syntax and semantics research involves obtaining a judgement of the acceptability of a sentence/meaning pair, typically by just the author of the paper, sometimes with feedback from colleagues. This methodology does not allow proper testing of scientific hypotheses because of (a) the small number of experimental participants (typically one); (b) the small number of experimental stimuli (typically one); (c) cognitive biases on the part of the researcher and participants; and (d) the effect of the preceding context (e.g., other constructions the researcher may have been recently considering). In the current paper we respond to some arguments that have been given in support of continuing to use the traditional nonquantitative method in syntax/semantics research. One recent defence of the traditional method comes from Phillips (2009), who argues that no harm has come from the nonquantitative approach in syntax research thus far. Phillips argues that there are no cases in the literature...
Scanless Hyperspectral Raman Imaging (HSRI) by Active-Illumination for SERS-based Multiplexed Molecular Imaging

We present hyperspectral Raman imaging for collecting Raman spectra from ~500 diffraction limited pixel within 1 second without mechanical scanning, from 100x100 μm2 field of view, which is applicable to multiplexed molecular imaging using SERS-tags.
Ultrabroad-bandwidth electro-optic modulator based on a cascaded Bragg grating.

It is shown that the bandwidth of a traveling-wave electro-optical modulator can be greatly increased by matching of the group velocities of the optical and rf waves in the waveguides with cascaded Bragg gratings. A LiNbO3 Mach–Zehnder modulator with 1-V half-wave voltage and a bandwidth in excess of 100 GHz is proposed and its performance evaluated.
Quantifying rates and timescales of geomorphic processes

In the past decade, the application of a variety of new tools has spurred significant advances in quantifying the rates and timing of geomorphic processes. These advancements resulted from improvements in methods for collecting and interpreting data, increased access to analytical facilities, and creative applications of techniques to new problems. New analytical techniques are emerging as mainstream procedures for evaluating the temporal and spatial variations of Earth surface processes. In this and the next issue of Earth Surface Processes and Landforms we highlight new applications of geochemical, field and modelling methods applied to problems in landform evolution. These applications address processes related to erosion and sedimentation on small, intermediate and large temporal and spatial scales. We present an overview of techniques and applications discussed in these two special issues, as well as some of the limitations and future challenges inherent to these techniques.
A “disposable” graphical event synthesizer for teaching simulation model building

This article describes an easy to use graphical simulator specifically designed for teaching the fundamental concepts of discrete event simulation modeling. The simulator permits students to have the satisfaction of building working models early in a course without having to learn a specific commercial language. The simulator is “disposable” in the sense that students can replace the various components of the simulator with their own routines as they progress through the course. It is thus possible for the students to customize their own personal graphically oriented modeling language. Models built on this simulator are also easily implemented in higher level simulation languages making the simulator a useful modeling aid even for simulation courses that are built around a specific language.
An L-arginine–nitric oxide–cyclic guanosine monophosphate system exists in the uterus and inhibits contractility during pregnancy☆☆☆*★★

Abstract OBJECTIVE: Nitric oxide is synthesized from L -arginine and it causes relaxation of smooth muscle by elevating cyclic guanosine monophosphate levels. We hypothesized that an L -arginine–nitric oxide–cGMP system is present in the uterus and modulates contractility. STUDY DESIGN: Isometric tension of the uterus was measured in vitro from pregnant rats in response to various agents that modulate nitric oxide–cyclic guanosine monophosphate production or action. RESULTS: Major findings are as follows: (1) The substrate and a donor of nitric oxide produced uterine relaxation; (2) inhibitors of the nitric oxide–cyclic guanosine monophosphate pathway blocked the relaxation responses; (3) nitric oxide synthase was localized to several uterine cell types; (4) nitric oxide was produced by the uterus during periods when L-arginine was consumed and citrulline levels increased; (5) effects of nitric oxide substrate on relaxation were mimicked by cyclic guanosine monophosphate; (6) nitric oxide–cyclic guanosine monophosphate responses were decreased during delivery; (7) L -arginine responses were increased by progesterone, and antiprogesterone treatment decreased cyclic guanosine monophosphate – induced relaxations. CONCLUSION: An L -arginine–nitric oxide–cyclic guanosine monophosphate system is present in the uterus and it may regulate relaxation during pregnancy. The inhibitory action of L -arginine and 8-bromo-cyclic guanosine monophosphate was considerably lower during delivery and post partum, indicating that the nitric oxide system may contribute to the maintenance of uterine quiescence during pregnancy, when progesterone levels are elevated, but not during delivery. (AM J OBSTET GYNECOL 1993;170:175-85.)
Reducing Undesirable Effects in the Human Centrifuge

The human centrifuge is used to train pilots and astronauts for flights where they are subject to large accelerations. This paper deals with the problems of simulating such linear accelerations with a rotating device and presents suitable means of reducing undesirable simulation error. The advantages of using three gimbals rather than the usual two are considered. Numerical results illustrate the problems of simulation and the improvement achieved by the use of a third gimbal.
Is awareness necessary for true inference

In transitive inference, participants learn a set of context-dependent discriminations that can be organized into a hierarchy that supports inference. Several studies show that inference occurs with or without task awareness. However, some studies assert that without awareness, performance is attributable to pseudoinference. By this account, inference-like performance is achieved by differential stimulus weighting according to the stimuli’s proximity to the end items of the hierarchy. We implement an inference task that cannot be based on differential stimulus weighting. The design itself rules out pseudoinference strategies. Success on the task without evidence of deliberative strategies would therefore suggest that true inference can be achieved implicitly. We found that accurate performance on the inference task was not dependent on explicit awareness. The finding is consistent with a growing body of evidence that indicates that forms of learning and memory supporting inference and flexibility do not necessarily depend on task awareness.
Comparison of Spatial Discretization Methods for Solving the SN Equations Using a Three-Dimensional Method of Manufactured Solutions Benchmark Suite with Escalating Order of Nonsmoothness

A comparison of the accuracy and computational efficiency of spatial discretization methods of the three-dimensional SN equations is conducted, including discontinuous Galerkin finite element metho...
Challenges in developing estimates of exposure rate near the Nevada Test Site.

As one of several dose reconstruction projects, the Off-site Radiation Exposure Review Project needed to develop models that reflect processes and lifestyles of the past and obtain accurate and adequate historical data to drive the models. One of the critical pieces, ultimately used to estimate the potential dose to people in the area surrounding the Nevada Test Site, was the development of exposure rate estimates used as input to the external and internal dose models. The historical data available for making these estimates were collected in manners and for purposes not necessarily consistent with the needs of this task. The Town Data Base is the culmination of the effort to develop those estimates for the Project`s Phase I region (or for locations near the Nevada Test Site that were primarily covered by ground monitoring at the time of the nuclear tests). It includes estimates of discernible exposure rate at 353 populated locations in Arizona, California, Nevada, and Utah and for 74 nuclear tests at the Nevada Test Site. Each dose reconstruction effort has similarities with, and variations from, others. This paper describes some of the challenges encountered in creating the Town Data Base and the approaches used to address them.more » These challenges included collecting historical data, incorporating net exposure rate values of zero into the estimates, defining a discernible fallout level, handling the lack of measurements at some locations and creating dispersion estimates. The approaches were developed to create {open_quotes}best{close_quotes} estimates and to use actual data (as opposed to assumed values) as the primary source where such data were available. A summary of the spatial distribution of these estimates and a comparison of relative levels of fallout by location are also included.« less
Gap-junctional properties of electrically coupled skate horizontal cells in culture.

Whole-cell voltage-clamp recordings were used to examine the unusual pharmacological properties of the electrical coupling between rod-driven horizontal cells in skate retina as revealed previously by receptive-field measurements (Qian & Ripps, 1992). The junctional resistance was measured in electrically coupled cell pairs that had been enzymatically isolated and maintained in culture; the typical value was about 19.92 MΩ(n = 45), more than an order of magnitude lower than the nonjunctional membrane resistance. These data and the intercellular spread of the fluorescent dye Lucifer Yellow provide a good indication that skate horizontal cells are well coupled. The junctional conductance between cells was not modulated by the neurotransmitters dopamine (200 μM) or GABA (1 mM), nor was it affected by the membrane-permeable analogues of cAMP or cGMP, or the adenylate cyclase activator, forskolin. Although resistant to agents that have been reported to alter horizontal-cell coupling in cone-driven horizontal cells, the junctional conductance between paired horizontal cells of skate was greatly reduced by the application of 20 mM acetate, which is known to effectively reduce intracellular pH. Together with the results obtained in situ on the receptive-field properties of skate horizontal cells, these findings indicate that the gap-junctional properties of rod-driven horizontal cells of the skate are fundamentally different from those of cone-driven horizontal cells in other species. This raises the possibility that there is more than one class of electrical synapse on vertebrate horizontal cells.
Optimal maintenance planning for repairable multi-component systems subject to dependent competing risks

Many complex multi-component systems suffer from dependent competing risks. The reliability modeling and maintenance planning of repairable dependent competing risks systems are challenging tasks because the repair of the failed component can change the lifetime of the other components when multiple components fail dependently. This article first proposes a generally dependent latent age model to capture the dependence of competing risks under general component repairs. Based on the proposed reliability model, both system- and component-level periodic inspection-based maintenance polices are considered for repairable multi-component systems that are subject to dependent competing risks. Under the system-level maintenance policy, the entire system is restored to the as-good-as-new state once a failure is detected. While under the component-level maintenance policy, only the failed component is repaired imperfectly. The optimal solution of the system-level policy is obtained by using renewal theory. The opt...
Efficient, blue light-emitting diodes using cross-linked layers of polymeric arylamine and fluorene

Abstract Single-, double- and triple-layer polymer light-emitting diodes (PLEDs) with indium-tin oxide (ITO) anodes and Ca cathodes were fabricated, based on solution processable and thermally cross-linkable hole transporting polyarylamine and blue luminescent polyfluorene; and an electron transporting oxadiazole trimer. Triple-layer PLEDs show the highest efficiency, brightness and saturation of blue emission. These results are interpreted in terms of charge injection balance and electron-hole recombination efficiency. The maximum external quantum efficiencies achieved (>1%) are comparable to the best polymer blue PLEDs.
Expression of retinoic acid receptor mRNA in hematopoietic cells

Abstract Retinoic acid (RA) has profound effects upon the proliferation and differentiation of many hematopoietic cells. The mechanism by which RA acts is unclear. Recently, several retinoic acid receptors (RAR) have been cloned. We studied expression of RAR-α mRNA by RNA blots in hematopoietic cells blocked at different stages of differentiation. All hematopoietic cells expressed RAR-α mRNA (3.4, 4.5 kb) including KG-1 (myeloblasts); HL-60 (promyelocytes); ML3, THP-1, U937 (myelomonoblasts and monoblasts); K562 (erythroblasts); and S-LB1 (T-lymphocytes). In addition, transformed cells from four non-hematopoietic tissues also expressed RAR-α mRNA. Steady-state levels of RAR-α mRNA were not affected by induction of terminal differentiation of HL-60 cells to either granulocytes or macrophages. Furthermore, both actively proliferating and resting lymphocytes from the same individuals expressed equal concentrations of RAR-α mRNA. Taken together, data suggest that level of expression of RAR-α mRNA is not related to cellular proliferation. We also showed that exposure to ligand (all-trans retinoic acid) did not change levels of RAR-α mRNA in three different cell types. Half-life of RAR-α mRNA was short (0.7 h) as determined by measuring decay of message after addition of actinomycin D. Consistent with this finding, accumulation of RAR-α mRNA increased in cells of three lines as their protein synthesis was inhibited. In summary, hematopoietic cells of different lineages and stages of differentiation constitutively express RAR-α mRNA. This expression is unaffected either by terminal differentiation or cell cycle. The RAR-α mRNA is short-lived and super-inducible by a protein synthesis inhibitor.
Effects of intermittent UVA exposure on cultured lens epithelial cells.

Purpose. This paper addresses the question of whether a single non-lethal dose of UVA radiation or the same dose divided three daily one-third doses have like or unlike effects on the growth and the catalase activity of cultured rabbit epithelial (RLE) and immortalized human epithelial (HLE) cells. Methods. Non-confluent cultured RLE and HLE cells were used to study the effects of UVA radiation on their growth. The effects of three doses of 3 J/cm 2 given one day apart on cell growth (i.e. live cell number) over a three day period were compared with those of a single 9 J/cm 2 exposure. Estimation of live cell numbers was done 24 hrs after each exposure by counting trypan blue exclusive cells using a hemocytometer. Confluent cultures of RLE cells were used to study the effects of UVA radiation on their catalase activity. The effects of three doses of 1.25 J/cm 2 each given one day apart on catalase activity (breakdown of H 2 O 2 measured spectro-photometrically at 240 nm) were compared with that of a singl...
Eliciting Honesty: How to Tell the Truth with Statistics

This paper describes and illustrates several models of randomized response sampling, a survey technique for eliciting truthful answers to sensitive questions.
Formation of Submicron Magnesite during Reaction of Natural Forsterite in H2O-Saturated Supercritical CO2

Abstract Natural forsterite was reacted in bulk liquid water saturated with supercritical CO 2 (scCO 2 ) and scCO 2 saturated with water at 35–80 °C and 90 atm. The solid reaction products were analyzed with nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and confocal Raman spectroscopy. Two carbonate phases, nesquehonite (MgCO 3 ·3H 2 O) and magnesite (MgCO 3 ), were identified with the proportions of the two phases depending on experimental conditions. In liquid water saturated with scCO 2 , nesquehonite was the dominant carbonate phase at 35–80 °C with only a limited number of large, micron size magnesite particles forming at the highest temperature, 80 °C. In contrast, in scCO 2 saturated with H 2 O magnesite formation was identified at all three temperatures: 35, 50, and 80 °C. Magnesite was the dominant carbonation reaction product at 50 and 80 °C, but nesquehonite was dominant at 35 °C. The magnesite particles formed under scCO 2 saturated with H 2 O conditions exhibited an extremely uniform submicron grain-size and nearly identical rhombohedral morphologies at all temperatures. The distribution and form of the particles were not consistent with nucleation and growth on the forsterite surface.
Detectors for neutron scattering in the eV region

Abstract With the advent of high-current high-energy proton accelerators used as pulsed neutron sources for condensed matter studies, interest in extending neutron scattering measurements to the eV region has increased. Among the instruments proposed is the resonance-detector spectrometer (RDS) which uses the sharp low-energy nuclear resonances (usually capture) to define the energy of the scattered neutron. These spectrometers require detectors with high efficiency and good background rejection. Two promising candidates for such detectors, a bismuth germanate (BGO) scintillator and a high-purity germanium (HPGe) detector have been tested at the NBS neutron time-of-flight facility. These tests used simple recoil scattering at high scattering angles and several different resonance foils. Efficiencies and signal to background ratios were measured.
An Individual Difference Perspective on Student Diversity.

The purpose of this study was to explore the relationships among various aspects of learning styles/strategies and personality dimensions to arrive at a “thicker” description of individual differences in functioning in general and in the school context in particular. An exploratory factor analysis of the subscales of the Inventory of Learning Processes-Revised and the NEO-Personality Inventory provided evidence for convergent and discriminant validity of six higher-order common factors. Hierarchical regression analyses were performed to differentially predict ILP-R subscales from NEO-PI subscales. The analyses were conducted separately for students identified as having high versus low academic self-esteem. The results support previous findings that self-concept variables strongly moderate relationships among personality and learning style dimensions. We discuss how the cross-fertilization between personality and learning theory and research enables us to better define what individual differences in learning consist of, how they originate, how they are manifested, what furthers or hinders their expression, and finally, to what extent they are amenable to change (maturation, development, training). Implications for school achievement, cognitive development and the productive use of individual differences in educational practice are discussed with regard to different types of learners.
Increased dietary sodium is independently associated with greater mortality among prevalent hemodialysis patients

Dietary sodium is thought to play a major role in the pathogenesis of hypertension, hypervolemia, and mortality in hemodialysis patients; hence, sodium restriction is almost universally recommended. Since the evidence upon which to base these assumptions is limited, we undertook a post-hoc analysis of 1770 patients in the Hemodialysis Study with available dietary, clinical, and laboratory information. Within this cohort, 772 were men, 1113 black, and 786 diabetic, with a mean age of 58 years and a median dietary sodium intake of 2080mg/day. After case-mix adjustment, linear regression modeling found that higher dietary sodium was associated with a greater ultrafiltration requirement, caloric and protein intake; sodium to calorie intake ratio was associated with a greater ultrafiltration requirement; and sodium to potassium ratio was associated with higher serum sodium. No indices were associated with the pre-dialysis systolic blood pressure. Cox regression modeling found that higher baseline dietary sodium and the ratio of sodium to calorie or potassium were each independently associated with greater all-cause mortality. No association between a prescribed dietary sodium restriction and mortality were found. Thus, higher reported dietary sodium intake is independently associated with greater mortality among prevalent hemodialysis patients. Randomized trials will be necessary to determine whether dietary sodium restriction improves survival.