cssi/SciSciGPT-SciSciNet huggingface dataset:
Creation and Evaluation of a Cesarean Section Simulator Training Program for Novice Obstetric Surgeons.

Background We evaluated a novel simulation-based cesarean section training program to teach critical techniques for cesarean section and hemorrhage management. Methods: This was a prospective educational intervention. After Institutional Review Board approval, we recruited Obstetrics and Gynecology, Family Medicine, and General Surgery residents at three hospitals. All participants received didactic education. Participants were then randomized into two arms with one group to receive task-trainer based training and the other no training. Afterwards, all residents had their performance of a complete cesarean section and management of a post-partum hemorrhage evaluated on a high-fidelity simulator. Evaluators were blinded to randomization. Experience Thirty-three participants were recruited between July 2017 and January 2019. There were 19 trainees in the control group and 14 in the intervention group. The intervention group scored significantly higher on performance of the cesarean delivery (p-value 0.007), hemorrhage management (p-value 0.0002), and overall skill (p-value 0.008). There were no differences in the other categories. Conclusion Participants trained with a combination of didactic education and task-trainers versus didactic education alone performed significantly better on all procedural aspects of a cesarean section and hemorrhage management on a high-fidelity simulator, demonstrating that simulation-based training allows trainees to gain procedural experience while decreasing patient risk.
Mechanochemical spinodal decomposition: a phenomenological theory of phase transformations in multi-component, crystalline solids

We present a phenomenological treatment of diffusion-driven martensitic phase transformations in multi-component crystalline solids that arise from non-convex free energies in mechanical and chemical variables. The treatment describes diffusional phase transformations that are accompanied by symmetry-breaking structural changes of the crystal unit cell and reveals the importance of a mechanochemical spinodal, defined as the region in strain–composition space, where the free-energy density function is non-convex. The approach is relevant to phase transformations wherein the structural order parameters can be expressed as linear combinations of strains relative to a high-symmetry reference crystal. The governing equations describing mechanochemical spinodal decomposition are variationally derived from a free-energy density function that accounts for interfacial energy via gradients of the rapidly varying strain and composition fields. A robust computational framework for treating the coupled, higher-order diffusion and nonlinear strain gradient elasticity problems is presented. Because the local strains in an inhomogeneous, transforming microstructure can be finite, the elasticity problem must account for geometric nonlinearity. An evaluation of available experimental phase diagrams and first-principles free energies suggests that mechanochemical spinodal decomposition should occur in metal hydrides such as ZrH2−2c. The rich physics that ensues is explored in several numerical examples in two and three dimensions, and the relevance of the mechanism is discussed in the context of important electrode materials for Li-ion batteries and high-temperature ceramics. A treatment to describe structural phase transformations in materials has been developed by researchers in the USA. Under favorable energetic conditions, some multicomponent solids such as lithium-ion battery electrodes can decompose from a uniform phase into two co-existing phases having different compositions. This spinodal decomposition affects the properties of a range of structural and electronic materials. Now, Krishna Garikipati at the University of Michigan and colleagues have modeled spinodal decomposition triggered by instabilities and variations in either strain or composition throughout a material. The model requires solving a system of complex nonlinear interactions through a computational framework, and represents a new phenomenological description of spinodal decomposition that could potentially be extended to other phase-transformation phenomena. The model may play a role in the study and development of practically relevant materials such as battery electrodes or nanoelectronics.
Prizes in Contests with Many Entrants

We examine the properties of all-pay contests in the spirit of Moldovanu and Sela (2001) as the number of entrants grows large under organizer objectives of expected and expected maximum outcomes. Unlike the case with a small number of entrants, with a large number of entrants a single prize becomes optimal even for an organizer with concave utility. Diminishing returns or risk-aversion on the part of the organizer do not justify multiple prizes in large contests. With optimal prizes determined asymptotically, we characterize the limiting value of outcomes in an optimal contest; exactly in the case of linear production and up to bounds in the concave/convex case. In all cases the limiting value is bounded away from zero. In the linear case, the limit is one-half the maximum feasible outcome.
Neural network enabled time stretch spectral regression.

Spectral interferometry is utilized in a wide range of biomedical and scientific applications and metrology. Retrieving the magnitude and phase of the complex electric field from the interferogram is central to all its applications. We report a spectral interferometry system that utilizes a neural network to infer the magnitude and phase of femtosecond interferograms directly from the measured single-shot interference patterns and compare its performance with the widely used Hilbert transform. Our approach does not require apriori knowledge of the shear frequency, and achieves higher accuracy under our experimental conditions. To train the network, we introduce an experimental technique that generates a large number of femtosecond interferograms with known (labeled) phase and magnitude profiles. While the profiles for these pulses are digitally generated, they obey causality by satisfying the Kramer-Kronig relation. This technique is resilient against nonlinear optical distortions, quantization noise, and the sampling rate limit of the backend digitizer – valuable properties that relax instrument complexity and cost.
Hybrid Analytical and Data-Driven Modeling Techniques for Digital Twin Applications

This paper summarizes, compares, and contrasts various modeling techniques which can be used in the notional digital twins which are under development for naval shipboard power and energy systems. The models can range from fully predetermined analytical models to fully data-driven empirical models, along with many hybrid approaches which fall between the two extremes. Hybrid approaches are of particular interest for digital twin applications as they can share benefits of both rigid analytical models and empirical models. One hybrid approach is proposed and discussed in detail as a particularly effective modeling solution. Drawbacks of the proposed approach are presented, along with further improvements which can mitigate those shortcomings.
Identification of novel membrane proteins for improved lignocellulose conversion

Lignocellulose processing yields a heterogeneous mixture of substances, which are poorly utilized by current industrial strains. For efficient valorization of recalcitrant biomass, it is critical to identify and engineer new membrane proteins that enable the broad uptake of hydrolyzed substrates. Whereas glucose consumption rarely presents a bottleneck for cell factories, there is also a lack of transporters that allow co-consumption of glucose with other abundant biomass sugars such as xylose. This review discusses recent efforts to bioinformatically identify membrane proteins of high biotech potential for lignocellulose conversion and metabolic engineering in both model and nonconventional organisms. Of particular interest are transporters sourced from anaerobic gut fungi resident to large herbivores, which produce Sugars Will Eventually be Exported Transporters (SWEETs) that enhance xylose transport in the yeast Saccharomyces cerevisiae and enable glucose and xylose co-utilization. Additionally, recently identified fungal cellodextrin transporters are valuable alternatives to mitigate glucose repression and transporter inhibition.
Symmetric Sparse Boolean Matrix Factorization and Applications.

In this work, we study a variant of nonnegative matrix factorization where we wish to find a symmetric factorization of a given input matrix into a sparse, Boolean matrix. Formally speaking, given $\mathbf{M}\in\mathbb{Z}^{m\times m}$, we want to find $\mathbf{W}\in\{0,1\}^{m\times r}$ such that $\| \mathbf{M} - \mathbf{W}\mathbf{W}^\top \|_0$ is minimized among all $\mathbf{W}$ for which each row is $k$-sparse. This question turns out to be closely related to a number of questions like recovering a hypergraph from its line graph, as well as reconstruction attacks for private neural network training. As this problem is hard in the worst-case, we study a natural average-case variant that arises in the context of these reconstruction attacks: $\mathbf{M} = \mathbf{W}\mathbf{W}^{\top}$ for $\mathbf{W}$ a random Boolean matrix with $k$-sparse rows, and the goal is to recover $\mathbf{W}$ up to column permutation. Equivalently, this can be thought of as recovering a uniformly random $k$-uniform hypergraph from its line graph. Our main result is a polynomial-time algorithm for this problem based on bootstrapping higher-order information about $\mathbf{W}$ and then decomposing an appropriate tensor. The key ingredient in our analysis, which may be of independent interest, is to show that such a matrix $\mathbf{W}$ has full column rank with high probability as soon as $m = \widetilde{\Omega}(r)$, which we do using tools from Littlewood-Offord theory and estimates for binary Krawtchouk polynomials.
Tracing changes in mantle and crustal influences in individual cone-building stages at Mt. Shasta using U–Th and Sr isotopes

Abstract 230Th-excess is rare in most arc lavas, but common in the Cascades, yet the origin of such excesses remains unclear. At Mt. Shasta, age-corrected (230Th/232Th) and (238U/232Th) activity ratios range from 1.108 to 1.290 and from 0.987 to 1.309 (27.3% 230Th-excess to 6.1% 238U-excess), respectively. Although small degrees of zircon crystallization ( At Mt. Shasta, the destruction of the ancestral cone (Sand Flat) was followed by four cone-building stages, three of which lie in the age range of U-series geochronology. Lavas within individual eruptive stages have relatively constant (230Th/232Th)0 ratios that are interpreted to reflect specific mixtures of mantle (m) and lower crustal (lc) melts that are characteristic of a specific stage ( M m : l c ). High (230Th/232Th)0 ratios identify higher proportions of lower crust in the Misery Hill stage ( M m : l c = ∼ 85 : 15 ), whereas low (230Th/232Th)0 ratios reflect the more mantle-like composition of the Shastina lavas ( M m : l c = ∼ 95 : 5 ); in the case of Shastina lavas, very low 87Sr/86Sr ratios, down to 0.7029, support a substantial mantle contribution. Changes in (230Th/232Th)0 ratios correlate with eruptive volume, where the most voluminous stage (Misery Hill) is inferred to have the largest proportion of crustal melt and highest (230Th/232Th)0 ratios. Variable (230Th/238U)0 ratios within, and between, eruptive groups likely reflect a combination of residence time in the lower crust and differential assimilation of bulk, non-garnet-bearing crust that had (230Th/238U) = 1. The volume-(230Th/232Th)0 relations are accompanied by correlations with 87Sr/86Sr ratios, where the most radiogenic Sr is associated with the largest eruptive volumes, indicating that the largest magmatic episodes produced the largest amount of lower crustal interaction. The new U–Th and Sr isotope measurements of this study, along with U-series data for other Cascade centers suggest that interaction with the lower crust exerts greater control on Cascade magma chemistry than previously recognized. Indeed, the relatively dry nature of the Cascades may offer a unique opportunity to better understand the influence of the deep crust in young continental arcs, as larger subduction components in other settings may overprint any lower crustal signature and produce lavas with large 238U-excesses.
sDOMO — A simple communication protocol for home automation and robotic systems

Today's market for domotic systems is dominated by proprietary communication protocols incompatible with each other. This not only prevents engineers from building highly integrated home automation and domestic robotic systems, but keeps prices artificially high due to a lack of competition in the market since the customers have to restrict their choices to components compatible with the system already deployed. In this paper, we propose a communication protocol for fully integrated domotic systems running on top of house network, protocol which is simple enough to accommodate as peers microcontroller based sensors but scalable enough to handle a house wide distributed computer vision system for domestic robot assisted living. Based on a house centered philosophy, the protocol is putting emphasis on privacy and protection of the residents.
NSF is up to new tricks.

Membrane trafficking depends on NSF, an ATPase that dissociates a complex of membrane proteins called SNAREs. A particular NSF mutant apparently lacks ATPase activity and cannot dissociate SNAREs, but can still promote membrane fusion in an in vitro assay. Might NSF, in certain systems, have actions we do not yet appreciate?
Exponential data weighting filter design for a class of nonlinear stochastic systems

The author considers unbiased linear state estimation of a class of nonlinear stochastic systems with noisy nonlinear measurement equations. Exponential data weighting ideas of linear filtering are applied to this class of systems. Results are obtained for both finite- and infinite-time filtering. In the time-invariant case, it is shown that mean square stability of the original system is sufficient for the existence of the unique nonnegative definite solution of the filter Riccati equation and that the filter has an exponential convergence rate. >
β-Catenin Inhibits T Cell Activation by Selective Interference with Linker for Activation of T Cells–Phospholipase C-γ1 Phosphorylation

Despite the defined function of the β-catenin pathway in thymocytes, its functional role in peripheral T cells is poorly understood. We report that in a mouse model, β-catenin protein is constitutively degraded in peripheral T cells. Introduction of stabilized β-catenin into primary T cells inhibited proliferation and cytokine secretion after TCR stimulation and blunted effector cell differentiation. Functional and biochemical studies revealed that β-catenin selectively inhibited linker for activation of T cells phosphorylation on tyrosine 136, which was associated with defective phospholipase C-γ1 phosphorylation and calcium signaling but normal ERK activation. Our findings indicate that β-catenin negatively regulates T cell activation by a previously undescribed mechanism and suggest that conditions under which β-catenin might be inducibly stabilized in vivo would be inhibitory for T cell-based immunity.
Some Observations on Future Directions in Fusion Energy Research

Over the years the author has written, coordinated, or contributed to numerous reviews of fusion energy. In revisiting them, he is encouraged by the tremendous progress that has been made across the board. Nevertheless, while he believes that a viable fusion reactor could be made in both magnetic and inertial fusion energy, he doesn’t think the best approach has yet been identified in either area. Also there remain a number of critical, hardly-explored areas. The author identifies three key issues. Finally, he comments briefly on all the major confinement approaches.
Rhetorical prototypes in architecture: Measuring the acropolis with a philosophical polemic

This essay interrogates the ways in which contemporary discourses about Periclean architecture rely on categories set up by the antisophistic polemics of Plato and Aristotle in the fourth century. These philosophers’ accusations that the sophists in the fifth century were deceptive, irrational, and excessive invade discussions about the designs of Periclean architecture. These assessments reflect arbitrary rhetorical prototypes of rationality and sense perception rather than the actual specifications of the architecture. On a broader note, this essay brings to light how rhetorical categories operate in the interpretation of historical phenomena, including the intagistic arts.
Inhibition of 14C-labeled amino acid incorporation into protein by particles and surface-active agents in human granulocytes.

Abstract Contact of human polymorphonuclear leukocytes with latex or zymosan particles resulted in inhibition of incorporation of 14 C-labeled amino acids into protein in the phagocytosing cells. The surface-active agents, concanavalin A and digitonin, exerted the same inhibitory activity on 14 C-labeled amino acid incorporation into protein in human granulocytes. The inhibition of 14 C label incorporation was dose dependent and the half-maximal effect per 10 7 cells was found at 0.8 mg of latex (0.79 μm in diameter), 0.25 mg of serum-coated zymosan and 35 μg of digitonin/ml of the incubation medium. Amino acid transport ( 14 C-labeled amino acids or amino[ 14 C]isobutyrate) was the same in the resting and phagocytosing granulocytes. These results suggest that the incorporation of 14 C-labeled amino acids into protein in human granulocytes is in some way connected to alteration in the cell plasma membrane.
Seeing the mean: ensemble coding for sets of faces.

We frequently encounter groups of similar objects in our visual environment: a bed of flowers, a basket of oranges, a crowd of people. How does the visual system process such redundancy? Research shows that rather than code every element in a texture, the visual system favors a summary statistical representation of all the elements. The authors demonstrate that although it may facilitate texture perception, ensemble coding also occurs for faces—a level of processing well beyond that of textures. Observers viewed sets of faces varying in emotionality (e.g., happy to sad) and assessed the mean emotion of each set. Although observers retained little information about the individual set members, they had a remarkably precise representation of the mean emotion. Observers continued to discriminate the mean emotion accurately even when they viewed sets of 16 faces for 500 ms or less. Modeling revealed that perceiving the average facial expression in groups of faces was not due to noisy representation or noisy discrimination. These findings support the hypothesis that ensemble coding
Studies on the carbohydrates of the slug Ariolimax columbianis with special reference to their distribution in the reproductive system

Abstract 1. 1. The major carbohydrate in the blood of the slug Ariolimax is glucose, which constitutes 84 per cent of the total carbohydrates. No oligosaccharides are present in the blood. Glycoproteins constitute 12 per cent of the total. 2. 2. The hepatopancreas showed the presence of glucose and maltose oligosaccharides, besides glycogen. 3. 3. Glycogen is present in large amounts in hepatopancreas and foot and in small quantities in the other regions of the body including the albumin gland. 4. 4. Galactogen is present only in the albumin gland. 5. 5. A sulphated acid mucopolysaccharide is present in the common duct region. Hydrolysis of this polysaccharide yielded two neutral sugars, galactose and fucose, and the amino sugar glucosamine. 6. 6. Administration of C 14 glucose resulted in the labelling of maltose oligosaccharides, glycogen, galactogen and acid mucopolysaccharide. Galactose, glycogen, galactogen and acid mucopolysaccharide. Galactose, fucose and glucosamine of the hydrolysate of the mucopolysaccharide showed labelling. 7. 7. Injection of labelled maltose also resulted in the labelling of maltotriose, maltotetrose, glycogen, galactogen and mucopolysaccharide. Glucose of the blood or liver did not show any labelling within 48 hr after maltose injection. 8. 8. Injected C 14 galactose carbon appeared in the galactogen and mucopolysaccharide but not in the glycogen or blood glucose. 9. 9. Eggs laid after the injection of labelled glucose and maltose showed radioactivity in the galactogen and mucopolysaccharide fractions.
Urinary lipase and effect of mecholyl and secretin

1. Der Harn gesunder Menschen enthalt ein fettspaltendes Ferment. 2. Im Harn des Hundes ist regelmasig ein fettspaltendes Ferment nachzuweisen. 3. Nach Injektion von Mecholyl und Secretin werden vom Hunde erheblich vermehrte Mengen von fettspaltendem Ferment ausgeschieden. 4. Die Wirkung des Secretin auf die Ausscheidung des fettspaltenden Fermentes ist langer anhaltend als die Auscheidung nach Mecholyl.
Counselling training in primary care education: A two-stage approach

Abstract Although primary care practitioners are increasingly called upon to manage the psychological stress of patients, they are often not equipped with relevant skills. Recent efforts to supply these skills suggest the need for a two-stage counselling-training format. For its training of midlevel primary care practitioners, the Health Associate Program of the Johns Hopkins University School of Health Services offers a counselling sequence that consists of a period of classroom didactics and skill development followed by a period of clinical experience. This sequence emphasizes the need for a defined stage at which students in their formative years can tie learned skills to explicit patient care. It is designed to provide students with the psychosocial skills that are needed for actual clinical work and for carrying out holistic health care.
In Vitro Susceptibility of Nocardia asteroides to N-Formimidoyl Thienamycin and Several Cephalosporins

Abstract The susceptibility of N. asteroides to N-formimidoyl thienamycin, cefamandole, cefoxitin, and moxalactam was determined by agar dilution. N-Formimidoyl thienamycin was the most active, inhibiting eight of nine strains at 1.56 μg/ml.
Plasma curvature effects on microwave reflectometry fluctuation measurements

Plasma poloidal curvature can significantly extend microwave reflectometry responses to high k⊥ poloidal fluctuations. Reflectometry responses can be several orders of magnitude larger at high k⊥ than that predicted by analysis based on two dimensional (2-D) slab geometry. As a result, the responses may approach the 1-D geometrical optics limit. This superresolution leads to a major modification of the spectral resolution of reflectometry. The phenomenon is analysed using a phase screen model for the general cases and the results are supported by detailed numerical 2-D realistic geometry full wave simulations for the specific case of the Alcator C-Mod tokamak.
Cesarean section in a parturient with HIV and recent cocaine and alcohol intake: anesthetic implications

We present a case of a human immunodeficiency virus (HIV) positive, poly-substance abusing parturient who presented for an emergency cesarean section following recent cocaine and alcohol intake. Spinal anesthesia was selected for the abdominal delivery. 4 min after delivery of the fetus, the patient developed hypotension, intermittent runs of ventricular tachycardia, premature ventricular complexes and ST-segment elevation. Induction of general anesthesia, endotracheal intubation, intravenous lidocaine and phenylephrine were required to restore stability. At the end of surgery the patient was stable and was extubated. The ST-segment elevation returned to normal 45 min postoperatively. Her postoperative course was uneventful.
Finite-element simulation of low-temperature, heat-pump-coupled, aquifer thermal energy storage

Abstract A two-dimensional, Galerkin finite-element, transport model was applied to a feasibility study of low temperature, heat pump coupled, aquifer thermal energy storage in a confined sandstone aquifer in northeastern Ohio. Simulations were run to determine the relative sensitivity of the model to transient versus steady-state radial flow, grid size, time-step lengths, and injection temperatures. In order to determine the effects of uncertainties in the values of aquifer and aquitard parameters, energy recovery factors and recovery temperatures were calculated for worst-case, best-case, and best-estimate simulations. Aquifer and aquitard parameters were either measured directly or were estimated based on previous hydrogeologic investigations. All simulations were performed assuming a 150 d injection phase with a pumping rate of 15 m 3 h −1 , a 35 d storage phase, and a 150 d production phase, also with a pumping rate of 15 m 3 h −1 . The worst-case simulation for an injection temperature of 23.9°C produced an energy recovery factor of 0.43 and a final production temperature of 14.6°C. The best-case simulation resulted in an energy recovery factor of 0.69 and a final production temperature of 16.2°C. The best-estimate simulation predicted an energy recovery factor of 0.50 and a final production temperature of 15.0°C. Both the energy recovery factor and the recovery temperature were most affected by the uncertainty in the storage formation longitudinal dispersivity. Using the best-estimate parameter values, an injection temperature of 18.0°C resulted in a final production temperature of 13.2°C and an energy recovery factor of 0.50. The best-estimate parameter values used with an injection temperature of 27.0°C yielded a final production temperature of 15.9°C and an energy recovery factor of 0.50.
NSF's three-phase program helps the small-business innovator bootstrap an idea to commercial success

A new National Science Foundation (NSF) program, introduced in part as a result of interest on the part of the U.S. Congress, has among its objectives greater utilization of small science and technology firms in U.S. Government R&D, and conversion of that research to technological innovation in the private sector. Called ?Small Business Innovation Applied to National Needs,? the new program solicits high-risk, potentially high-payoff, proposals from small business relating to the research objectives of the Applied Science and Research Applications (ASRA) Directorate.
A Test of Environmental, Situational, and Personal Influences on the Ethical Intentions of CEOs:

A national survey of CEOs of manufacturing firms was conducted to identify factors explaining CEOs' intentions to engage in two questionable business practices: soliciting a competitor's technological secrets and making payments to foreign government officials to secure business. Drawing on research in corporate misconduct, ethical decision making, and strategic management, the authors analyzed ethical intentions by looking at hostile environmental conditions, opportunity-rich situations, and/or personal characteristics. Based on responses to scenarios, their findings suggest that the ethical intentions of CEOs may be more affected by the decision maker's predisposition than by environmental pressures or organizational/situational characteristics.
Searching for directly decaying gluinos at the Tevatron

Abstract This Letter describes how to perform searches over the complete kinematically-allowed parameter space for new pair-produced color octet particles that each subsequently decay into two jets plus missing energy at the Tevatron. This Letter shows that current searches can miss otherwise discoverable spectra of particles due to CMSSM-motivated cuts. Optimizing the H T and E T cuts expands the sensitivity of these searches.
Towards computer-assisted qualitative analysis for model development: theory and algorithms

The modeling process involves a qualitative analysis, also referred to as problem structuring, of the problem prior to formulation of the mathematical representation. Current modeling systems provide limited support to modelers in the qualitative analysis. The author develops hypotheses about qualitative analysis for model development, specifically optimization models. His hypothesis views qualitative analysis as a process that includes, among other things, identification of complete, consistent, and relevant elements of a problem. The hypothesis has been implemented as a prototype system that can be part of integrated modeling environments to support the modeling process. Although the hypothesis, and the algorithms used in the current system are domain-independent, the author illustrates them with production planning examples. >
Identification and characterization of promoters regulating tuf expression in Chlamydia trachomatis serovar F.

Abstract Gene expression in the obligate intracellular bacterium Chlamydia trachomatis ranges from nil in the infectious EB form to high in the dividing RB form. Little is known about the mechanisms of gene regulation in chlamydiae and only a few promoter sequences have been characterized. The purpose of our study was to examine the expression of a cluster of genes that are required for translation in C. trachomatis serovar F: infA (encoding Initiation Factor 1), tRNA Thr , tuf (encoding Elongation Factor Tu), and tRNA Trp . Primer extension analysis indicated that tuf is expressed in three different mRNAs. Putative promoter sequences for these transcripts were defined as P1 (upstream of tRNA Thr ), P2 (within infA ) and P3 (upstream of infA ). Quantitative RT-PCR analysis revealed that P1 transcripts were most abundant at 16 h postinfection (pi), whereas P2 transcripts predominated at 24 h pi. P3 was active at all times pi; however, transcription terminated upstream of tuf at early times pi and continued through tuf at later times. P1 and P3 were active in Escherichia coli, as assessed by CAT expression in promoter-fusion vectors and a chlamydial in vitro transcription system. Site-specific mutagenesis confirmed the importance of the −35 and −10 hexamers in the P1 and P3 promoters. P2 was weakly active in E. coli and inactive in the in vitro transcription system, indicating either that the P2 transcript is processed from a longer transcript or that P2 expression requires a sigma or transcription factor which is not present in E. coli or the in vitro transcription system. Our data suggest that multiple processes play a role in the regulation of tuf gene expression during the developmental cycle.
Collective Behaviors in Two-Dimensional Systems of Interacting Particles

This article presents results of molecular dynamics simulations that show the emergence of collective behaviors in a two-dimensional system of particles (hard disks) interacting through a properly chosen collision rule. The particles, which are of finite size and are in free flight between collisions, are not self-propelled. They tumble randomly like bacteria and interact only when they collide, not through continuous potential forces. This work therefore indicates that interactions at the microscopic level, which occur only locally and discretely both in time and space, are sufficient to lead to large-scale macroscopic behaviors. Order parameters that capture and quantify the formation of collective behaviors are introduced and used to describe how the choice of collision rule affects the steady state dynamics of the system, by comparing the outcome to the standard case of elastic collisions. This work was motivated by recent results on the dynamics of bacterial colonies. Possible applications of the pre...
Treatment of a radiation-induced esophageal web with retrograde esophagoscopy and puncture.

Abstract Objective To present a technique for the treatment of complete esophageal stenosis in the post-radiation patient that may be applied to selected patients with obstructing stenoses. Study design A case report of the treatment of a post-radiation esophageal web. Methods A review of the patient's history of treatment and a discussion of reported treatment options. Results A complete obstruction of the cervical esophagus was diagnosed in a patient after chemoradiation for a hypopharyngeal carcinoma. Retrograde esophagoscopy through the patient's percutaneous endoscopic gastrostomy tube site aided visualization and perforation of the obstructing tissue. Subsequent dilation has allowed the patient to resume oral intake of a regular diet without restrictions. Conclusion Combined direct laryngoscopy with retrograde esophagoscopy represents a viable alternative to more extensive approaches for recannulization of selected obstructing esophageal stenoses.
Inert gas narcosis: Avoidance behavior in rats breathing elevated pressures of nitrogen and helium

Avoidance response rates generated by a free-operant avoidance schedule with a response-shock interval of 20 sec and a shock-shock interval of 2 sec increased when rats breathed raised pressures of nitrogen up to 19 times normal atmospheric pressure. Further, nitrogen pressure increases to over 30 times normal pressure produced decreases in avoidance rates and disruption of temporal discrimination reflected by changes in conditional probabilities of interresponse times. Changes in avoidance response rates and shock frequencies were related to increases in nitrogen partial pressures rather than total absolute pressure as oxygen and carbon dioxide partial pressures were kept at normal atmospheric levels, and similar avoidance performance changes did not occur at identical pressures breathing helium. Increased helium pressures produced increases in avoidance responding at 25 to 30 times normal atmospheric pressure that were similar to effects of nitrogen at lower pressures, indicating that nitrogen is about four times as potent as helium in terms of narcotic effects on avoidance behavior.
Self-consistent tight binding molecular dynamics study of TiO2 nanoclusters in water

Abstract Self-consistent tight binding molecular dynamics studies of TiO 2 anatase and rutile nanoclusters in dissociable water are reported. It is found that the structure of the particle expands as a result of interaction between the particle’s surface and water. Water molecules dissociate at the nanoparticle surface during simulation.
Cardiac Ca2+ Dynamics: The Roles of Ryanodine Receptor Adaptation and Sarcoplasmic Reticulum Load

We construct a detailed mathematical model for Ca2+ regulation in the ventricular myocyte that includes novel descriptions of subcellular mechanisms based on recent experimental findings: 1) the Keizer-Levine model for the ryanodine receptor (RyR), which displays adaptation at elevated Ca2+; 2) a model for the L-type Ca2+ channel that inactivates by mode switching; and 3) a restricted subspace into which the RyRs and L-type Ca2+ channels empty and interact via Ca2+. We add membrane currents from the Luo-Rudy Phase II ventricular cell model to our description of Ca2+ handling to formulate a new model for ventricular action potentials and Ca2+ regulation. The model can simulate Ca2+ transients during an action potential similar to those seen experimentally. The subspace [Ca2+] rises more rapidly and reaches a higher level (10-30 microM) than the bulk myoplasmic Ca2+ (peak [Ca2+]i approximately 1 microM). Termination of sarcoplasmic reticulum (SR) Ca2+ release is predominately due to emptying of the SR, but is influenced by RyR adaptation. Because force generation is roughly proportional to peak myoplasmic Ca2+, we use [Ca2+]i in the model to explore the effects of pacing rate on force generation. The model reproduces transitions seen in force generation due to changes in pacing that cannot be simulated by previous models. Simulation of such complex phenomena requires an interplay of both RyR adaptation and the degree of SR Ca2+ loading. This model, therefore, shows improved behavior over existing models that lack detailed descriptions of subcellular Ca2+ regulatory mechanisms.
Improving Weight Maintenance Using Virtual Reality (Second Life)

Abstract Objective Compare weight loss and maintenance between a face-to-face (FTF) weight management clinic and a clinic delivered via virtual reality (VR). Methods Participants were randomized to 3 months of weight loss with a weekly clinic delivered via FTF or VR and then 6 months' weight maintenance delivered with VR. Data were collected at baseline and 3 and 6 months for weight and process variables. Twenty overweight and obese individuals (31.1 ± 3.6 years of age; body mass index, 32.8 ± 5.1; 85% females; 20% minorities) responded to advertisement and met inclusion criteria. Diets (1,200–1,800 kcal/d) used prepackaged meals, fruits and vegetables, and physical activity (300 min/wk). Results Weight loss was significantly greater for FTF at 10.8% compared with 7.6% for VR (P Conclusions and Implications Virtual reality compares favorably with FTF for weight loss and may facilitate greater weight maintenance.
Midpalatal implants for orthodontic anchorage.

DESIGN: Randomised controlled trial. INTERVENTION: Patients with various malocclusions in which any forward movement of the molars would prevent achievement of an ideal Class I canine relationship were randomly allocated to either the headgear or the implant group. Randomisation was carried out by using a block design and computer-generated random numbers. The allocations were concealed in consecutively numbered, sealed envelopes. OUTCOME MEASURE: The outcomes were; surgical and orthodontic success rates of the implants, the number of visits, the length of treatment time and the success of treatment as judged by the peer assessment rating (PAR) score reductions and the patients' attitudes to implant placement. RESULTS: The surgical success rate of the implants was 75% and the orthodontic success rate was more than 90%. Both implants and headgear proved to be effective methods of reinforcing anchorage. The total number of visits was greater in the implant group, but the overall treatment times were almost identical. There were no statistically significant differences between the 2 groups in PAR scores either at the start or the end of treatment, and the percentages of PAR score reductions were almost identical. The patients had no problems accepting midpalatal implants as a method of reinforcing anchorage. CONCLUSIONS: The use of palatal implants to reinforce anchorage was as effective as extraoral anchorage with headgear.
Antisense modulation of the coding or regulatory sequence of the folate receptor (folate binding protein‐1) in mouse embryos leads to neural tube defects

BACKGROUND Although folic acid decreases the incidence of neural tube defects (NTDs) in humans, the mechanism for this protection is unknown. We have employed antisense technology to alter expression of the gene for the folate receptor (folate binding protein-1 [Folbp1]) in mouse embryos cultured in vitro. METHODS Embryos were explanted on day 8 of gestation and cultured for 44 hr. Several oligodeoxyribonucleotides designed to modulate the coding region or a regulatory sequence in the 5′-untranslated region of Folbp1 were microinjected into the amniotic sac of embryos at the beginning of the culture period. RESULTS Two different antisense sequences to the 5′ and 3′ coding region in Folbp1 produced concentration-dependent increases in the number of embryos with NTDs. Coinjection of 5-methyltetrahydrofolate with these sequences decreased the frequency of abnormal embryos. A semi-quantitative RT-PCR technique used to measure the amount of Folbp1 mRNA in treated and control embryos confirmed that the mRNA level was decreased by treatment with the antisense sequences. An antisense oligodeoxyribonucleotide to a 17 base cis regulatory element also generated a concentration-dependent increase in the frequency of embryos with NTDs, and a decrease in the level of Folbp1 mRNA. CONCLUSIONS These results demonstrate that alterations in expression of Folbp1 by perturbing either the coding sequence or a critical regulatory cis-element can play a role in NTDs. Birth Defects Research (Part A) 67475–487, 2003. © 2003 Wiley-Liss, Inc.
Nerve growth factor induces plasma extravasation in rat skin

The intradermal application of both mouse and bovine nerve growth factor induced dose-dependently increased vascular permeability as indicated by Evans blue extravasation. Plasma extravasation by nerve growth factor was markedly reduced by capsaicin pretreatment or a combination of H1- and H2-histamine antagonists. The finding that biologically inactive nerve growth factor failed to elicit protein leakage indicates that plasma extravasation by nerve growth factor is a characteristic of the biologically active molecule.
Differential regulation of CD4+ T helper cell responses by curcumin in experimental autoimmune encephalomyelitis

Nutraceuticals and phytochemicals are important regulators of human health and diseases. Curcumin is a polyphenolic phytochemical isolated from the rhizome of the plant Curcuma longa (turmeric) that has been traditionally used for the treatment of inflammation and wound healing for centuries. Systematic analyses have shown that curcumin exerts its beneficial effects through antioxidant, antiproliferative and anti-inflammatory properties. We and others have shown earlier that curcumin ameliorates experimental autoimmune encephalomyelitis (EAE) model for multiple sclerosis. In this study, we show that C57BL/6 mice induced to develop EAE express elevated levels of interferon (IFN) γ and interleukin (IL)-17 in the central nervous system (CNS) and lymphoid organs that decreased significantly following in vivo treatment with curcumin. The EAE mice also showed elevated expression of IL-12 and IL-23 that decreased after treatment with curcumin. Ex vivo and in vitro treatment with curcumin resulted in a dose-dependent decrease in the secretion of IFNγ, IL-17, IL-12 and IL-23 in culture. The inhibition of EAE by curcumin was also associated with an up-regulation of IL-10, peroxisome proliferator activated receptor γ and CD4(+)CD25(+-)Foxp3(+) Treg cells in the CNS and lymphoid organs. These findings highlight that curcumin differentially regulates CD4(+) T helper cell responses in EAE.
Polarization Rotation via a Monoclinic Phase in the Piezoelectric 92%PbZn1/3Nb2/3O3-8%PbTiO3

The origin of ultrahigh piezoelectricity in the relaxor ferroelectric PbZn(1/3)Nb(2/3)O3-PbTiO3 was studied with an electric field applied along the [001] direction. The zero-field rhombohedral R phase starts to follow the direct polarization path to tetragonal symmetry via an intermediate monoclinic M phase, but then jumps irreversibly to an alternate path involving a different type of monoclinic distortion. Details of the structure and domain configuration of this novel phase are described. This result suggests that there is a nearby R-M phase boundary as found in the Pb(Ti,Zr)O3 system.
Faculty contracting for the technical management of an academic radiology department: A case study

I n this case study, we describe how an academic radiology department and its academic medical center-both of which were adversely affected by changes in the economic environment but confronting different financial incentives--negotiated an agreement for the radiology faculty to manage the technical aspects of the department that traditionally fall under medical center control. The resultant benefits to the radiologists and the medical center included (1) more coordinated delivery of service; (2) better preservation of quality of service in a time of decreasing resources; (3) better alignment of the goals of the radiologists and hospital; and (4) improved physician-hospital administration working relationships. We also detail models of departmental organizational structure, quality of service, and cost that were adopted to facilitate implementation of the departmental-medical center agreement.
Model Robust Calibration: Method and Application to Electronically-Scanned Pressure Transducers

This article presents the application of a recently developed statistical regression method to the controlled instrument calibration problem. The statistical method of Model Robust Regression (MRR), developed by Mays, Birch, and Starnes, is shown to improve instrument calibration by reducing the reliance of the calibration on a predetermined parametric (e.g. polynomial, exponential, logarithmic) model. This is accomplished by allowing fits from the predetermined parametric model to be augmented by a certain portion of a fit to the residuals from the initial regression using a nonparametric (locally parametric) regression technique. The method is demonstrated for the absolute scale calibration of silicon-based pressure transducers.
Disparities in treatment for substance use disorders and co-occurring disorders for ethnic/racial minority youth.

Objective To review the literature on racial and ethnic disparities in behavioral health services and present recent data, focusing on services for substance use disorders (SUD) and comorbid mental health disorders for children and adolescents. Method A literature review was conducted of behavioral health services for minority youth. Articles were included if specific comparisons in receipt of SUD services for youth were made by race or ethnicity. The review was organized according to a sociocultural framework. Results Compared with non-Latino Whites with SUD, Black adolescents with SUD reported receiving less specialty and informal care, and Latinos with SUD reported less informal services. Potential mechanisms of racial and ethnic disparities were identified in federal and economic health care policies and regulations, the operation of the health care system and provider organization, provider level factors, the environmental context, the operation of the community system, and patient level factors. Significant disparity decreases could be achieved by adoption of certain state policies and regulations that increase eligibility in public insurance. There is also a need to study how the organization of treatment services might lead to service disparities, particularly problems in treatment completion. Institutional and family characteristics linked to better quality of care should be explored. Because treatments appear to work well independent of race/ethnicity, translational research to bring evidence-based care in diverse communities can bolster their effectiveness. Conclusions This review suggests promising venues to decrease ethnic and racial disparities in behavioral health services for ethnic and racial minority youth.
School Choice as a Latent Variable: Estimating the “Complier Average Causal Effect” of Vouchers in Charlotte

Randomized field trials of school voucher policy interventions face major statistical hurdles in the measurement of a voucher effect on student achievement. Selection bias undermines the benefits of randomization when the treatment, a random offer of a voucher, is declined by participants who systematically differ from those who accept. This article argues that the complier average causal effect (CACE) is the parameter of interest in voucher evaluations. As an example, the CACE is estimated using data from a small, one-year field trial of vouchers in Charlotte, NC. In this estimation, voucher impacts in Charlotte are positive, but appear to be moderated by the probability of compliance. For math achievement, maximum likelihood CACE estimates are smaller and insignificant compared to intention to treat and instrumental variable estimates of mean treatment effects.
Demand for power

World Energy Supply: Resources. Technologies. Perspectives. By Manfred Grathwohl. Walter de Gruyter: 1982. Pp.450. DM120, $54.