cssi/SciSciGPT-SciSciNet huggingface dataset:
Track-draw: A graphical interface for controlling the parameters of a speech synthesizer

In this report we describe a graphical interface for generating voiced speech using a frequency-domain implementation of the Klatt (1980) cascade formant synthesizer. The input to the synthesizer is a set of parameter vectors, calledtracks, which specify the overall amplitude, fundamental frequency, formant frequencies, and formant bandwidths at specified time intervals. Tracks are drawn with the aid of a computer mouse that can be used either inpoint-draw mode, which selects a parameter value for a single time frame, or inline-draw mode, which uses piecewise linear interpolation to connect two user-selected endpoints. Three versions of the program are described: (1) SYNTH draws tracks on an empty time-frequency grid, (2) SPECSYNTH creates a spectrogram of a recorded signal upon which tracks can be superimposed, and (3) SWSYNTH is similar to SPECSYNTH, except that it generatessine-wave speech (Remez, Rubin, Pisoni, & Carrell, 1981) using a set of time-varying sinusoids rather than cascaded formants. The program is written for MATLAB, an interactive computing environment for matrix computation. Track-Draw provides a useful tool for investigating the perceptually salient properties of voiced speech and other sounds.
Modulation of feeding by hypothalamic paraventricular nucleus α1- and α2-adrenergic receptors

Noradrenergic receptor populations within the paraventricular hypothalamus (PVN) modulate feeding. Satiated rats exhibit enhanced feeding subsequent to activation of alpha 2-adrenergic receptors within the PVN induced by exogenous infusion of either norepinephrine (NE) or clonidine (CLON). The feeding-stimulatory effect of alpha 2-adrenergic agents presumably reflects an inhibitory action on receptors located on medial hypothalamic "satiety" cells. Adrenergic receptors of the alpha 1-subclass have been identified within the PVN which are excitatory and which may function to suppress food intake. Microinjection into rat PVN of various alpha 1-adrenergic agonists including cirazoline, methoxamine, phenylpropanolamine and phenylephrine suppress feeding; an effect that is reversed by pretreatment with alpha 1-adrenergic receptor antagonists. The present review argues that alpha 1- and alpha 2-adrenoceptors within brain and specifically within the PVN are organized in an antagonistic fashion and that the effects of various adrenergic agonists on feeding may reflect the degree to which these agonists act at alpha 1- and alpha 2-adrenoceptors as well the relative balance of these receptors and their activity within the PVN.
A retrospective clinicopathological analysis of appendiceal tumors from 3,744 appendectomies: a single-institution study

This study was conducted to describe the clinicopathological characteristics of appendiceal tumors and to evaluate their appropriate management. Between September 2000 and September 2005, 28 appendiceal tumors were identified by a retrospective review of 3,744 appendectomies. Twenty-eight patients were found to have appendiceal tumors (incidence, 0.7%).The largest single group of tumors were benign mucinous cystadenomas (50%); carcinoids (32.1%) were next, and they were followed by malignant tumors (17.9%). Four out of five patients who had malignant appendiceal tumors presented with periappendiceal abscess. None of the patients was correctly diagnosed preoperatively. One-stage curative resection was possible in more than 76% of the patients, and the rate of making the correct preoperative diagnosis was 35%. Most appendiceal tumors presented with appendicitis and periappendiceal abscess. Appendiceal tumors should be included in the differential diagnosis when an unexpected appendiceal mass is encountered during appendectomy.
Single Molecule Investigation of RNA Polymerase I using Multiplexed Tethered Particle Motion

In eukaryotic cells, RNA Polymerase I (Pol I), which produces ribosomal RNA (rRNA), catalyzes up to 80% of all transcriptional activity in growing cells, and its regulation is an emerging field of study for anti-cancer drug development. In order to gather more comprehensive information about ribosomal RNA production by Pol I, we conducted single molecule experiments to characterize rates and pauses in the elongation phase of transcription by wild-type and mutant Pol I. Transcription by individual molecules was based on real-time measurements using custom multiplexed Tethered Particle Motion (TPM) microscopy. Microspheres were attached to one end of a DNA template engaged in an elongation complex with a Pol I molecule immmuno-imobilized on a coverslip. The range of Brownian motion of the microsphere was a function of the tether length that in turn depended on the progress of the polymerase. Either the lack of a full complement of associated factors or the constitution of in vitro transcription assay limited of polymerase activity to only 1-2%. In order to increase the throughput of the transcription assay, we increased the field of view and implemented a particle-tracking algorithm to track a high number of beads simultaneously in real time. The time courses of rare transcription events were analyzed for velocity and pausing. The processivity of Pol I without tension on the DNA template was remarkably lower than observed in studies of Pol II transcribing DNA templates under a few picoNewtons of tension. Furthermore, as reported previously based on bulk experiments, the average elongation rate of an F1205H mutant was lower than that of wild-type Pol I. At least six possible pause sites were also identified including one recently found in bulk transcription study.
Effect of Non-Newtonian Behavior on Hemodynamics of Cerebral Aneurysms

Blood flow dynamics near and within cerebral aneurysms have long been implicated in aneurysm growth and rupture. In this study, the governing equations for pulsatile flow are solved in their finite volume formulation to simulate blood flow in a range of three-dimensional aneurysm geometries. Four constitutive models are applied to investigate the influence of non-Newtonian behavior on flow patterns and fluid mechanical forces. The blood's non-Newtonian behavior is found to be more significant, in particular, vascular geometries, and to have pronounced effects on flow and fluid mechanical forces within the aneurysm. The choice of constitutive model has measurable influence on the numerical prediction of aneurysm rupture risk due to fluid stresses, though less influence than aneurysm morphology.
Smad4‐Shh‐Nfic signaling cascade–mediated epithelial‐mesenchymal interaction is crucial in regulating tooth root development

Transforming growth factor beta (TGF-beta)/bone morphogenetic protein (BMP) signaling is crucial for regulating epithelial-mesenchymal interaction during organogenesis, and the canonical Smad pathway-mediated TGF-beta/BMP signaling plays important roles during development and disease. During tooth development, dental epithelial cells, known as Hertwig's epithelial root sheath (HERS), participate in root formation following crown development. However, the functional significance of HERS in regulating root development remains unknown. In this study we investigated the signaling mechanism of Smad4, the common Smad for TGF-beta/BMP signaling, in HERS in regulating root development. Tissue-specific inactivation of Smad4 in HERS results in abnormal enamel and dentin formation in K14-Cre;Smad4(fl/fl) mice. HERS enlarges but cannot elongate to guide root development without Smad4. At the molecular level, Smad4-mediated TGF-beta/BMP signaling is required for Shh expression in HERS and Nfic (nuclear factor Ic) expression in the cranial neural crest (CNC)-derived dental mesenchyme. Nfic is crucial for root development, and loss of Nfic results in a CNC-derived dentin defect similar to the one of K14-Cre;Smad4(fl/fl) mice. Significantly, we show that ectopic Shh induces Nfic expression in dental mesenchyme and partially rescues root development in K14-Cre;Smad4(fl/fl) mice. Taken together, our study has revealed an important signaling mechanism in which TGF-beta/BMP signaling relies on a Smad-dependent mechanism in regulating Nfic expression via Shh signaling to control root development. The interaction between HERS and the CNC-derived dental mesenchyme may guide the size, shape, and number of tooth roots.
Stimulatory effects of transforming growth factor-beta and epidermal growth factor on epidermal cell outgrowth from porcine skin explant cultures

Transforming growth factor-beta (TGF-beta) is known to stimulate dermal wound healing events (fibroplasia and fibrosis). In this study, the effect of TGF-beta on epidermal wound healing (re-epithelialization) was examined. Epidermal cell outgrowth from partial-thickness porcine skin explants was used as an in vitro model for epithelialization. All cultures were grown in medium with 1% fetal bovine serum, which was sufficient for explant viability but low enough to permit measurement of modulation by added factors. Because TGF-beta is known to act in concert with other growth factors, it was evaluated alone and in the presence of epidermal growth factor (EGF) and platelet-derived growth factor (PDGF). The results indicate that TGF-beta produced earlier initiation of outgrowth, by 1-2 d compared with control cultures, and increased the rate of outgrowth during the migratory phase of culture (Days 1 -3). Compared to controls, EGF alone produced a greater percentage of growing explants and an increased rate of outgrowth during the mitotic phase (Days 4-7). TGF-beta (1 or 10 mg/ml) and EGF (5 ng/ml) had an additive rather than a synergistic effect on outgrowth. PDGF-treated explants did not show enhanced growth when PDGF (2.5 units/ml) was added alone or together with TGF-beta and EGF. The ability of TGF-beta to produce earlier initiation of outgrowth was not due to an effect on mitosis, because TGF-beta did not increase the incorporation of [3H]thymidine into keratinocytes in the growing epidermal sheets. Rather, it is likely that TGF-beta facilitated keratinocyte migration, possibly by unmasking a receptor on the epidermal cell surface. These results suggest that TGF-beta may play a role in early epidermal wound healing.
Low Cost DC to 6 GHz Electronic Step Attenuator SMT MCMs with Gate Lag Elimination By Use of High Intensity LEDs

Output step attenuators for microwave test instrumentation are continually being pushed to perform faster, more reliably, with lower loss and less distortion, and at lower cost. This paper describes a state of the art GaAs FET switch IC based, high dynamic range step attenuator topology using SMT MCMs operating from DC to 6 GHz that has low loss, low distortion, fast switching speed with minimized transients, and low cost. These modules use light from high intensity LEDs reflected off of the package lid in a novel, low cost manner to provide compact, inexpensive elimination of the gate lag effect commonly associated with GaAs FET based switching, such that this attenuator provides an amplitude stable output within 20us of when a change of attenuation state is initiated. This is the first reported usage of light from LEDs reflected off of the lid of an MCM SMT package to eliminate the gate lag effect in a GaAs FET switch based subsystem.
Decoding myocardial Ca2+ signals across multiple spatial scales: A role for sensitivity analysis

Abstract Numerous studies have employed mathematical modeling to quantitatively understand release of Ca 2 + from the sarcoplasmic reticulum (SR) in the heart. Models have been used to investigate physiologically important phenomena such as triggering of SR Ca 2 + release by Ca 2 + entry across the cell membrane and spontaneous leak of Ca 2 + from the SR in quiescent heart cells. In this review we summarize studies that have modeled myocardial Ca 2 + at different spatial scales: the sub-cellular level, the cellular level, and the multicellular level. We discuss each category of models from the standpoint of parameter sensitivity analysis, a common simulation procedure that can generate quantitative, comprehensive predictions about how changes in conditions influence model output. We propose that this is a useful perspective for conceptualizing models, in part because a sensitivity analysis requires the investigator to define the relevant parameters and model outputs. This procedure therefore helps to illustrate the capabilities and limitations of each model. We further suggest that in future studies, sensitivity analyses will aid in simplifying complex models and in suggesting experiments to differentiate between competing models built with different assumptions. We conclude with a discussion of unresolved questions that are likely to be addressed over the next several years. This article is part of a Special Issue entitled “Calcium Signaling in Heart”.
Superlattices of Platinum and Palladium Nanoparticles

The authors have used a nonionic inverse micelle synthesis technique to form nanoclusters of platinum and palladium. These nanoclusters can be rendered hydrophobic or hydrophilic by the appropriate choice of capping ligand. Unlike Au nanoclusters, Pt nanoclusters show great stability with thiol ligands in aqueous media. Alkane thiols, with alkane chains ranging from C{sub 6} to C{sub 18} were used as hydrophobic ligands, and with some of these they were able to form 2-D and/or 3-D superlattices of Pt nanoclusters as small as 2.7 nm in diameter. Image processing techniques were developed to reliably extract from transmission electron micrographs (TEMs) the particle size distribution, and information about the superlattice domains and their boundaries. The latter permits one to compute the intradomain vector pair correlation function of the particle centers, from which they can accurately determine the lattice spacing and the coherent domain size. From these data the gap between the particles in the coherent domains can be determined as a function of the thiol chain length. It is found that as the thiol chain length increases, the gaps between particles within superlattice domains increases, but more slowly than one might expect, possibly indicating thiol chain interdigitation.
Choice modulates the neural dynamics of prediction error processing during rewarded learning.

Abstract Our ability to selectively engage with our environment enables us to guide our learning and to take advantage of its benefits. When facing multiple possible actions, our choices are a critical aspect of learning. In the case of learning from rewarding feedback, there has been substantial theoretical and empirical progress in elucidating the associated behavioral and neural processes, predominantly in terms of a reward prediction error, a measure of the discrepancy between actual versus expected reward. Nevertheless, the distinct influence of choice on prediction error processing and its neural dynamics remains relatively unexplored. In this study we used a novel paradigm to determine how choice influences prediction error processing and to examine whether there are correspondingly distinct neural dynamics. We recorded scalp electroencephalogram while healthy adults were administered a rewarded learning task in which choice trials were intermingled with control trials involving the same stimuli, motor responses, and probabilistic rewards. We used a temporal difference learning model of subjects' trial-by-trial choices to infer subjects' image valuations and corresponding prediction errors. As expected, choices were associated with lower overall prediction error magnitudes, most notably over the course of learning the stimulus–reward contingencies. Choices also induced a higher-amplitude relative positivity in the frontocentral event-related potential about 200 ms after reward signal onset that was negatively correlated with the differential effect of choice on the prediction error. Thus choice influences the neural dynamics associated with how reward signals are processed during learning. Behavioral, computational, and neurobiological models of rewarded learning should therefore accommodate a distinct influence for choice during rewarded learning.
Peripheral, but not central nervous system, type I interferon expression in mice in response to intranasal vesicular stomatitis virus infection

Type I interferon (IFN) is critical for resistance of mice to infection with vesicular stomatitis virus (VSV). Wild type (wt) VSV infection did not induce type I IFN production in vitro or in the central nervous system (CNS) of mice; however IFN-β was detected in lungs, spleen, and serum within 24 h. The M protein mutant VSV, T1026R1 (also referred to as M51R), induced type I IFN production in vitro and in the CNS, with poor expression in spleens. In addition, VSV T1026R1 was not pathogenic to mice after intranasal infection, illustrating the importance of IFN in controlling VSV replication in the CNS. Experiments with chemical sympathectomy, sRAGE, and neutralizing antibody to VSV were performed to investigate the mechanism(s) utilized for induction of peripheral IFN; neither sRAGE infusion nor chemical sympathectomy had an effect on peripheral IFN production. In contrast, administration of neutralizing antibody (Ab) readily blocked the response. Infectious VSV was transiently present in lungs and spleens at 24 h post infection. The results are consistent with VSV traffic from the olfactory neuroepithelium to peripheral lymphoid organs hematogenously or via lymphatic circulation. These results suggest that VSV replicates to high titers in the brains of mice because of the lack of IFN production in the CNS after intranasal VSV infection. In contrast, replication of VSV in peripheral organs is controlled by the production of large amounts of IFN.
The interaction of two fluid phases in fractured media

In fractured porous media, interactions between immiscible fluid phases within the fractures place a critical control on system behavior. A key component of the interactions is the geometry, or structure, of the respective phases. Over the past 10 years, process-based experiments have greatly increased our understanding of phase structure development within individual fractures. In the past 2 years, new calculational models that incorporate some of this understanding have further demonstrated the influence of phase structure on flow and transport within the phases, and inter-phase mass transport. These computational models can now be applied to consider the efficacy and parameterization of constitutive relations for a subset of two-phase situations. Full understanding of the morphology, connectivity, and temporal dynamics of phase structure in rough-walled fractures is yet to be developed, and is a promising area for further research.
Thyroid hormones in relation to urinary metabolites of non-persistent insecticides in men of reproductive age.

Human exposure to contemporary-use insecticides is widespread, but effects of exposure on human endocrine function have gone largely untested to date. Samples of urine and blood were collected concurrently from 322 adult men between the years 2000 and 2003. Urine samples were analyzed for 3,5,6-trichloro-2-pyridinol (TCPY), a metabolite of chlorpyrifos and chlorpyrifos-methyl, and 1-napththol (1N), a metabolite of carbaryl and naphthalene. Serum samples were analyzed for free T4, total T3, and thyroid stimulating hormone (TSH). There was an association between TCPY and TSH, where an interquartile range (IQR) increase in TCPY was associated with a 9% (95% confidence interval 0–18%) increase in TSH. There was also a suggestive inverse association between TCPY and free T4. There were no associations between 1N and thyroid hormones. Environmental exposure to chlorpyrifos, chlorpyrifos-methyl, or its metabolite TCPY may be associated with altered thyroid function in human males.
Iterative nonlinear precoding and link adaptation for MU-MIMO with CSI impairments

An iterative nonlinear precoding technique based on the Tomlinson-Harashima precoder is proposed for MU-MIMO to alleviate the performance degradation due to mismatches between actual Channel State Information (CSI) and impaired CSI available at the transmitter. A robust design is presented to feedback the effective channel rather than the nonprecoded channel for relay backhaul channel. A Channel Quality Indicator (CQI) generation is proposed for the base station (eNB) to estimate the receivers' signal-to-interference-plus-noise ratio taking into account impact of quantization errors. Numerical studies verify that the combination of the proposed iterative precoding and effective channel feedback significantly reduces the high sensitivity to quantization errors and improves the quality of radio link between the eNB and receiver. The proposed CQI feedback method enables the transmitter to accurately derive the effective channel quality seen by the receiver. Therefore, a tight link adaptation loop can be achieved to fully utilize the improved radio link.
Toroidal splitting observations from the Great 1994 Bolivia and Kuril Islands Earthquakes

The June 9, 1994, Bolivia earthquake and the October 4, 1994, Kuril Islands earthquake provide a unique opportunity for a splitting analysis of the Earth's long-period toroidal free oscillations. We present toroidal splitting observations for the 6 fundamental modes 0T4, 0T5, 0T6, 0T7, 0T8, and 0T9, and for the 5 first overtones 1T1, 1T2, 1T3, 1T4 and 1T6. The first identification of mode 1T1 is made possible by simultaneously fitting the multiplets 1T1 and 0T7. The observed splitting is reasonably well explained by current shear velocity models of the mantle. Our analysis yields new estimates of the center frequencies and quality factors of these 11 toroidal modes.
Modeling of web conveyance systems for multivariable control

A distributed parameter model of the lateral dynamic behavior of a moving web in an n-roller system is proposed. A span of web moving longitudinally and under tension is modeled as a beam with shear flexibility (Timoshenko beam). A quasistatic simplification of the model is made on the basis of spectral separation. Boundary conditions at the web-roller interface are considered. Actuator dynamics are introduced through the formulation of the boundary conditions. Closed-loop simulations using a state-space version of the simplified model are in agreement with experimental results. >
Mutagenic activity in diesel exhaust particulates

Chloroform eluates of diesel exhaust particulate extracts were mutagenic in the Ames test. The mutagenic activity of approximately 480 revertants/100 ..mu..g of extract/plate did not require liver enzymes for its expression. The addition of liver enzymes decreased mutagenic activity, an effect which has previously been shown to be non-specific binding of the mutagen to liver proteins. After reduction of the diesel exhaust extract with sodium borohydride, the S-9 independent activity was greatly diminished. Addition of S-9 to the reduced sample revealed the presence of S-9 dependent mutagenic activity. These results, although not conclusive, provide additional evidence for the presence of nitronarene mutagens in diesel exhaust particulates. If, for example, the samples contained nitrofluorene, nitronaphthalene or nitropyrene, the reduction reaction would have formed aminofluorene, aminonaphthalene, and aminopyrene, compounds which are mutagens requiring liver enzyme activation in the Ames test. Attempts to isolate the amine by acidic extraction were not successful, however, because of the weak mutagenic activity in the sample.
Cannabinoid receptor 2-mediated attenuation of CXCR4-tropic HIV infection in primary CD4+ T cells

Agents that activate cannabinoid receptor pathways have been tested as treatments for cachexia, nausea or neuropathic pain in HIV-1/AIDS patients. The cannabinoid receptors (CB(1)R and CB(2)R) and the HIV-1 co-receptors, CCR5 and CXCR4, all signal via Gαi-coupled pathways. We hypothesized that drugs targeting cannabinoid receptors modulate chemokine co-receptor function and regulate HIV-1 infectivity. We found that agonism of CB(2)R, but not CB(1)R, reduced infection in primary CD4+ T cells following cell-free and cell-to-cell transmission of CXCR4-tropic virus. As this change in viral permissiveness was most pronounced in unstimulated T cells, we investigated the effect of CB(2)R agonism on to CXCR4-induced signaling following binding of chemokine or virus to the co-receptor. We found that CB(2)R agonism decreased CXCR4-activation mediated G-protein activity and MAPK phosphorylation. Furthermore, CB(2)R agonism altered the cytoskeletal architecture of resting CD4+ T cells by decreasing F-actin levels. Our findings suggest that CB(2)R activation in CD4+ T cells can inhibit actin reorganization and impair productive infection following cell-free or cell-associated viral acquisition of CXCR4-tropic HIV-1 in resting cells. Therefore, the clinical use of CB(2)R agonists in the treatment of AIDS symptoms may also exert beneficial adjunctive antiviral effects against CXCR4-tropic viruses in late stages of HIV-1 infection.
The Kaiser-Wilhelm Institut fr physikalische Chemie und Elektrochemie at Dahlem, near Berlin

ON October I Prof. F. Haber began his work as director of the new Kaiser-Wilhelm Institut fur physikalische Chemie und Elektrochemie at Dahlem, near Berlin. The buildings of the institute, work upon which was begun during the summer of this year, are being erected by the Prussian Government working in conjunction with the Koppel-Stiftung for the purpose of improving the intellectual relations of Germany with other lands.
Characterization of the two myotoxin a isomers from the prairie rattlesnake (Crotalus viridis viridis) by capillary zone electrophoresis and fluorescence quenching studies

The two myotoxin a isomers from the venom of the prairie rattlesnake Crotalus viridis viridis have different isoelectric points, as determined by capillary zone electrophoresis. The pI values are 10.50 and 10.57, respectively, and both are higher than the previously reported pI value for myotoxin a. The difference in the isoelectric points between the two isomers is attributed to altered surface charge as a result of the conformational change in myotoxin a. Both isomers exist in crude venom, discounting the possibility that they are artifacts formed during the purification process. Fluorescence quenching of myotoxin a reveals heterogeneity of the tryptophans, possibly due to different environments. The fraction of the total tryptophan fluorescence quenched by iodide is 81% and is attributed to solvent-accessible tryptophan residues at the protein surface. The 19% non-quenchable tryptophans probably represent residues that are shielded from the solvent exposure. The ratio of buried to exposed tryptophans is similar to the ratio of isomers seen by capillary zone electrophoresis and reverse-phase high-performance liquid chromatography (c. 1 : 4).
Holistic vs. Hole-Istic E&P Strategies

E&P is a risky business because, while a few exploration projectsare tremendously successful, most are total failures. This makesmanagement of uncertainty crucial. Development of seismic tech-nology in the 1930’s and 1940’s substantially reduced the risk infinding petroleum. The resulting geology and geophysics (G&G)revolutionized petroleum exploration.Decision analysis traditionally has been applied to rank projectshole by hole, determining (on an individual basis) whether theyshould be explored and developed. Today this “hole-istic” approachis being challenged by a holistic one that takes into account theentire portfolio of potential projects as well as current holdings.This portfolio analysis starts with representations of the local uncer-tainties of the individual projects provided by geology and geo-physics. It then takes into account global uncertainties by addingtwo additional G’s: geoeconomics and geopolitics, thereby reducingrisks associated with price fluctuations and political events in addi-tion to those addressed by traditional G&G analysis. The holisticapproach is based on, but not identical to, the Nobel-prize winningportfolio theory
Field analog studies of the distribution of windblown sediments at Amboy Crater, California, with application to Mars

Abstract Many shallow craters in the Spirit Mars Exploration Rover site contain asymmetric distributions of windblown sediments, which could indicate the predominant local wind direction at the time of their deposition or redistribution. Terrestrial analog field work at the Amboy lava field, Mojave Desert, California, included real-time wind measurements and assessments of active sediment deposition in four small (
Failure Mode of Pedicle Screw Fixation Depends Upon the Presence, Absence, and Position of Interbody Spacers. A Pilot Study

Transpedicular screw fixation permits segmental stabilization to supplement anterior, transforamenal, posterior lumbar interbody, or postero-lateral fusion techniques. This study was designed to evaluate the use of ASTM F1717-14 in determining the failure mode of pedicle screw constructs using these four different fusion constructs. Single level pedicle screw constructs were assembled and tested for axial stiffness and possible failure mode. The constructs included interbody spacers placed anteriorly, unilaterally, posteriorly, and with no spacer. The anterior specimens failed at supraphysiologic loads with rods bending in the sagittal plane. The unilateral specimens failed in physiologic range of loads with expulsion of the spacers and deformation of the constructs in the coronal plane. The posterior specimens failed at supraphysiologic loads and relatively large cycle numbers with screw fatigue fractures and subsequent set screw disengagement. The specimens with no spacers failed at physiologic loads with abutting of the anterior aspect of the test blocks. Failure of lumbar fusion constructs in this laboratory model occur in different modes depending on the fusion construct. In general, when the spacer is placed in line with the load axis, the pedicle instrumentation is “protected” from failure. When the spacer is off the load axis or no spacer is used, the pedicle screw system is subject to potential failure within physiologic loads. Considering the different modes of failure depending on placement of the interbody device, no single testing model is applicable to all clinically used constructs.
Operational aspects of terminating randomization in the multicenter trial of cryotherapy for retinopathy of prematurity

The Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) is a randomized clinical trial sponsored by the National Eye Institute (NEI) designed to test whether cryotherapy applied to eyes of premature infants with a specified extent of stage 3+ ROP significantly decreases the incidence of an unfavorable outcome. An unfavorable outcome is defined as either retinal detachment or a retinal fold and was determined at 3 months posttreatment by the use of a masked photographic system. Enrollment into the trial was terminated on recommendation of the Data and Safety Monitoring Committee 9 months before the scheduled closing date for enrollment because of demonstrated treatment benefit. The purpose of this article is to discuss the operations involved in the orderly termination of enrollment and dissemination of results from this trial. These activities included preparation of trial participants and staff, release of trial information, continuing patient care, data collection and coding, and publication of trial results.
Co-occurring chronic conditions and healthcare expenditures associated with Parkinson's disease: a propensity score matched analysis.

Abstract Background The objective of this study was to ascertain co-occurring chronic conditions and expenditures associated with Parkinson's disease among elderly individuals (age ≥ 65 years). Methods A retrospective, cross-sectional matched case–control design with data from Medical Expenditure Panel Survey (MEPS), a nationally representative survey of households in the United States was used. Elderly with Parkinson's disease (N = 350) were compared to a matched control group (N = 1050) based on propensity scores. Ordinary Least Squares regressions on logged dollars were performed to understand the association between Parkinson's disease and expenditures. All analyses accounted for the complex survey design of the MEPS and were conducted in SAS 9.3. Results Among elderly, the average total expenditures were $15,404 for those with Parkinson's disease and $13,333 for those without Parkinson's disease. Results from regressions revealed that elderly with Parkinson's disease had 109% greater total expenditure compared to those without Parkinson's disease, when only demographic and socioeconomic variables were entered in the model. When co-occurring chronic conditions were additionally included in the model, those with Parkinson's disease had 84% greater expenditures compared to those without Parkinson's disease. Conclusions Excess expenditures associated with Parkinson's disease are partially driven by co-occurring conditions among individuals with Parkinson's disease.
Individual differences in children's ability to profit from picture adjunct aids

Abstract A paired-associate memory task with pictures and words as items was used to categorize fourth graders into four learner types: HH, high picture-high word; HL, high picture-low word; LH, low picture-high word; LL, low picture-low word. Some children in each classification read prose passages with picture adjunct aids; other children read the passages without adjunct aids. Although free recall for the prose passage yielded inconclusive data, a constructed response test for facts in the prose passages revealed significant Aptitude × Treatment interactions, such that poor paired-associate learners (i.e., LLs) profited more than did good paired-associate learners (i.e., HHs) from picture aids on the prose task. The children's standardized reading scores were positively related to memory performance, but good and poor readers did not differ in their ability to profit from picture aids. It was suggested that less-strategic learners, such as those who perform poorly on paired-associate tasks, are more likely to be helped by externally provided mediational aids, while more-strategic learners are more likely to be helped by instructions to generate their own mediational aids.
Serum concentrations and analgesic effects of liposome-encapsulated and standard butorphanol tartrate in parrots.

Objective—To compare serum concentrations of liposome-encapsulated butorphanol tartrate (LEBT) and standard butorphanol tartrate (STDBT) following SC and IM administration, respectively, and to evaluate analgesic effects of LEBT and STDBT after parenteral administration to Hispaniolan parrots. Animals—11 adult Hispaniolan parrots. Procedure—The ability of LEBT to prolong the duration of analgesia in an avian species was tested. Blood samples were collected at serial time points after SC administration of LEBT (10 mg/kg or 15 mg/kg) or IM administration of STDBT (5 mg/kg). Serum concentrations of butorphanol tartrate were determined by use of a commercial immunoassay that measured parent drug and metabolites. Analgesic efficacy was evaluated in parrots exposed to electrical and thermal stimuli. Foot withdrawal thresholds were recorded at baseline and at serial time points after LEBT (15 mg/kg), liposome vehicle, STDBT (2 mg/kg), or physiologic saline (0.9% NaCl) solution administration. Results—LEBT had a ...
A Jarman/Bell model of primate feeding niches

Some of the behavioral-ecological variation in the primate order can be explained by reference to a general model known as the Jarman/Bell principle. This principle involves a scaling relationship between metabolism and body size which suggests that body size is a fundamental tactic in an animal's feeding strategy. Relatively accurate predictions regarding the diets of primates of known body weight follow from this model. In addition, it can be expanded to predict the kinds of adaptations that would appear in animals that deviate from the expected size/diet pattern. The model is general enough such that, when joined with feeding strategy theory, it can be applied to extinct organisms. In this context it is suggested that Pleistocene hominid ecology was characterized more by omnivory than carnivory.
Stuttering behavior: A phonetic analysis☆

Abstract Phonetic transcriptions were made of 500 stutterings, 25 each from 20 adult stutters. The findings were: 1. 1. Repetition and prolongation were the only behaviors common to all. 2. 2. The average duration of 1.6 sec, with a standard deviation of 3 sec. 3. 3. The mean length of the prolongations was 0.87 sec, with a standard deviation of 0.72 sec. 4. 4. More than 4 out of 5 repetitions—83%—were phoneme and syllable repetitions. 5. 5. Phrase repetition was comparatively rare, comprising only 5% of the repetitions. 6. 6. There was a strong tendency for various stuttering behaviors to be aligned into a definite sequence, or stuttering pattern. 7. 7. Ninety-six percent of the stuttering occured in relation to initial sounds. 8. 8. One-half of the blocks involved some degree of stuttering on the wrong sound. 9. 9. Stutterers frequently continued to stutter on words they had already said. 10. 10. Stutterers described as their “hard sounds” the initial sounds they actually uttered successfully, to the exclusion of the remainder of the word. 11. 11. Stuttering was seen chiefly as a disorder of release , with irrelevancies and crutches employed as instrumental acts to satisfy fear and bring about termination of the block.
Composite overlapping meshes for the solution of partial differential equations

Abstract We discuss the generation of curvilinear composite overlapping grids and the numerical solution of partial differential equations on them. A composite overlapping grid consists of a set of curvilinear component grids that cover a region and overlap where they meet. Continuity conditions (interpolation) are imposed at the overlapping boundaries. The principal advantage of composite grids is in the generation of grids for regions with complicated geometries. The grid construction program CMPGRD is used to create composite grids with any number of component grids. We describe some techniques for the solution of elliptic and time-dependent PDEs on composite meshes. Applications to the solution of the compressible Navier-Stokes equations are presented.
A method for the determination of activated receptor phosphorylation state following in vivo drug treatment.

Abstract Reversible phosphorylation events can alter many critical cellular functions and has been hypothesized to play a role in the development of tolerance to chronically administered agonists. The technique described here was developed to assess the phosphorylation state of μ-opioid receptor protein isolated from rodent brain tissue following 4 days of continual, subcutaneously released morphine. We have adapted and combined two techniques: back-phosphorylation reactions, which make use of tissue from animal models, and phosphorylation followed by immunoprecipitation, an approach used in cell culture models. μ-receptor protein is precipitated using a receptor-specific antibody, and the protein phosphorylation state is preserved by the use of phosphatase inhibitors. Phosphorylation sites that are dephosphorylated on the isolated protein are then radiolabelled by the addition of purified cAMP-dependent protein kinase (PKA) catalytic subunit and [ 32 P ]ATP. The samples are separated by gel electrophoresis, and the resulting bands are quantified using a phosphoimager. The amount of 32 P incorporated into the protein is assumed to be inversely related to the degree of phosphorylation prior to the reaction (i.e., the in vivo state of the protein). These estimates of μ-opioid receptor phosphorylation can then be correlated with a behavioral endpoint such as antinociception, to better understand the role of phosphorylation events in tolerance development. Themes: Neurotransmitters, modulators, transporters and receptors Topics: Second messengers and phosphorylation, receptor modulation, up- and down-regulation
GEOMETRIC EFFECTS ON EARTHQUAKE NUCLEATION ON BENT DIP-SLIP FAULTS

The geometric effects on earthquake nucleation processes on bent dip-slip faults are studied using a slip strengthening and weakening friction law implemented in a two-dimensional quasi-static boundary integral model. The results show that the bend causes normal stress variations under tectonic loading on both the upper and lower segments. These stress variations differ from those on planar faults, leading to significant effects on earthquake nucleation location and time. Earthquakes tend to nucleate at shallower locations on thrust faults and at deeper locations on normal faults for steeper dipping angles on the lower fault segments. The elapsed time until nucleation on both thrust and normal faults is increased considerably as the bend angle becomes larger. For a thrust fault with a nearly horizontal lower segment, the time until nucleation can be more than 10 times larger than that for a corresponding planar fault. These findings may provide important insights for earthquake hazard analysis by taking the fault geometry effect into account when estimating hypocenter positions and time to instability.
Effects of age and body lead burden on CNS function in young children. II. EEG spectra.

Abstract This study explored the effects of age and PbB upon EEG power spectra and various measures of hemispheric laterality in children, aged 13–75 months, watching a display (cartoon). The following are the principle conclusions: 1. (1) The δ- and θ-band amplitude decreased with age. 2. (2) When only bilaterally synchronized EEG between P3 and P4 was considered, the amplitude of P3 was estimated as greater than P4 in all frequency bands and for all ages. Previous reports have not shown lateral EEG dominance in children below 75 months. 3. (3) When lateral dominance measures consider only the relationship between synchronized EEG at P3 and P4, bilateral communality in the δ band increased with age. 4. (4) Increased PbB generally produced an increase in the relative amplitude of synchronized EEG between P3 and P4 in all frequency bands. This was true for PbB levels well below 15 μg/dl, among the lowest level PbB effects previously reported. No clinical or behavioral effects of PbB values have been reported below 15 μg/dl. It appears to be theoretically and practically important to understand the functional significance of bilaterally synchronized activity. The signal processing of the CNS can be explored using these methods. Greater understanding of these data would help define the extent and etiology of PbB effects on the CNS.
Monocarboxylic Acids in Murray and Murchison Carbonaceous Meteorites

THAT carbonaceous meteorites contain organic substances has been known for more than a century, and during this time controversies developed concerning whether or not this organic material was a product of extraterrestrial life. Within the past few years studies of carbonaceous meteorites have provided solid evidence that certain organic compounds are indigenous and were most likely produced by non-biological, chemical syntheses1–7. These studies have emphasised the occurrences of amino acids and hydrocarbons in two C2 carbonaceous chondrites, the Murray and the Murchison. We have now found in specimens of both of these meteorites straight and branched-chain mono-carboxylic acids having two to eight carbon atoms. Although many of these acids are of biological significance, the distribution of compounds in these meteorites supports the proposition that they, like the amino acids and hydrocarbons, result from non-biological, chemical syntheses.
Application of a minimum probability of error classifier with Linear Time-Varying pre-filters for buried target recognition

In this paper we overview the theory of Linear Time-Varying (LTV) filters and investigate via simulation their application to buried target classification in challenging nonstationary environments; in particular, environments where noise is not only nonstationary but exhibits statistical properties that are not known a priori. We then propose an extension of the Minimum Probability of Error (MPE) classifier (a/k/a Minimum Distance Receiver) by pre-processing the received data through a bank of LTV filters before the calculation of each test statistic via the MPE classifier. The proposed augmented MPE classifier is shown to outperform the conventional MPE classifier via simulation.
Field-Portable Pixel Super-Resolution Microscopy of Dense Samples using Lensfree Holograms Recorded at Multiple Heights

By capturing lensfree in-line holograms of objects at multiple heights, phase and amplitude images of dense specimens (e.g. Papanicolaou smears) can be iteratively reconstructed over a large field-of-view (~30 mm2) with sub-micron resolution.
Reconciliation of the absorption change at 325 nm and other flash-yield determinations of concentrations of active photosystem II centers

The concentration of photosystem II was determined in thylakoids of dwarf peas by the use of the following methods: absorption change at 325 nm; atrazine binding; and flash yields of oxygen evolution (Emerson-Arnold method), of protons from oxidation of water, and of reduction of DCIP. For the first time all of the flash-yield measurements have been done on the same sample and give equivalent values for the concentration of photosystem II. Agreement of the absorption change measurement at 325 nm with the other measurements was accomplished by the introduction of important improvements to the methods of Melis and co-workers [Proc. Natl. Acad. Sci. USA (1980) 77, 4712-4716]. The atrazine-binding method gave photosystem II values that were twice as large as any of the other photosystem II measurements. Possible reasons are discussed for this discrepancy in terms of the secondary acceptor (Q400) of Ikegami and Katoh [Plant Cell Physiol. (1973) 14, 829-836]. The concentration of photosystem I was measured by absorption change at 705 nm. From the concentration values of photosystem II and I the system II/I stoichiometry was calculated.
Forecasting correlation among equity mutual funds

Abstract Investors often buy multiple funds that are actively managed, specializing within narrowly defined market segments. To successfully implement a strategy of diversification investors must obtain accurate estimates of correlation among mutual fund returns. This paper forecasts mutual fund correlations using eight models that are broadly classified into historical, mean and index. Results indicate that estimate of future correlations from the Multi-Style Index, Dynamic and Fama–French 3-Factor models have the lowest prediction errors. Moreover, the relative ranks of Multi-Style Index and Fama–French 3-Factor models have lower dispersion across different forecasting time periods and in sub-samples of funds belonging to similar or different ‘style’ categories.
Determining what our students need most: exploring student perceptions and comparing difficulty ratings of students and faculty

If the goal of teaching is to help students understand a subject, teaching cannot begin until student difficulties with a subject are understood. In order to create a guide for assessing student difficulties with chemistry material, students were asked to rate exam questions on three factors: problem difficulty, familiarity, and self-confidence. These surveys were then compared to difficulty ratings of the same questions as determined by chemistry professors. Students' ratings of problem difficulty, problem familiarity, and self-confidence correlated, as expected, with their success on exam problems. There was also some agreement between students and faculty on the difficulty of exam problems, though students were much more accurate of judging problem difficulty than were chemistry professors. Students were surveyed in two separate cohorts to test year-to-year reliability.