cssi/SciSciGPT-SciSciNet huggingface dataset:
Ultrasound-guided procedures in medical education: a fresh look at cadavers

Demand for bedside ultrasound in medicine has created a need for earlier exposure to ultrasound education during the clinical years of undergraduate medical education. Although bedside ultrasound is often used for invasive medical procedures, there is no standardized educational model for procedural skills that can provide the learner a real-life simulated experience. The objective of our study was to describe a unique fresh cadaver preparation model, and to determine the impact of a procedure-focused ultrasound training session. This study was a cross-sectional study at an urban academic medical center. A sixteen-item questionnaire was administered at the beginning and end of the session. Fifty-five third year medical students participated in this 1-day event during their surgical clerkship. Students were trained to perform the following ultrasound-guided procedures: internal jugular vein cannulation, femoral vein cannulation femoral artery cannulation and pericardiocentesis. Preparation of the fresh cadaver is easily replicated and requires minor manipulation of cadaver vessels and pericardial space. Fifty-five medical students in their third year participated in this study. All of the medical students agreed that US could help increase their confidence in performing procedures in the future. Eighty percent (95 % CI 70–91 %) of students felt that there was a benefit of learning ultrasound-based anatomy in addition to traditional methods. Student confidence was self-rated on a five-point Likert scale. Student confidence increased with statistical significance in all of the skills taught. The most dramatic increase was noted in central venous line placement, which improved from 1.95 (SD = 0.11) to 4.2 (SD = 0.09) (p < 0.001). The use of fresh cadavers for procedure-focused US education is a realistic method that improves the confidence of third year medical students in performing complex but critical procedures.
Scaling wireless full-duplex in multi-cell networks

We investigate the open problem of characterizing the multiplexing gain offered by FD in a network of M cells (compared to the gain of two available on a single link). While self-interference cancellation is fundamental in realizing full duplex (FD) capability, the more challenging problem in a network-wide deployment of FD communication is a new form of uplink-downlink interference, namely UDI, caused by transmission of uplink clients on the downlink reception of other clients operating in the same frequency band during FD. We leverage spatial interference alignment (IA) as an effective approach to address UDI and characterize the scalability of the FD's multiplexing gain (in terms of M) by providing a closed-form expression. To the best of our knowledge, this is the first characterization of FD's multiplexing gain in a multi-cell network. We also provide an IA construction that can achieve the best scaling possible. Further, we extend our results to practical settings with limited number of clients and limited information sharing between access points.
Organic desulfurization of Illinois No. 6 coal

First, lithium aluminum hydride cleanly removes pyrite from the Illinois No. 6 coal to leave the original organosulfur compounds. Second, the SET reagent selectively removes sulfur from heterocyclic sulfur compounds and aromatic sulfides. Lochmann`s base does not remove the sulfur from the heterocycles, but does react with sulfidic sulfur compounds such as alkyl aromatic sulfides that are susceptible to base catalyzed elimination reactions. Third, the organic sulfur compounds that remain after the dual SET and BASE treatment are dominantly aliphatic substances including alkyl and allylic thiols and fourth the sulfur compounds that remain are susceptible to thermal decomposition and acid hydrolysis.
Fishing Rights and Race Relations

Prejudice in Politics . Group Position, Public Opinion, and the Wisconsin Treaty Rights Dispute. By Lawrence D. Bobo and Mia Tuan . Harvard University Press, Cambridge, MA, 2006. 288 pp. $40, £25.95, €36.90. ISBN 0-674-01329-8. Exploring how racial prejudice shapes the fate of political claims of a minority group, the authors discuss the controversy that surrounded the efforts of Wisconsin's Chippewa Indians to assert their traditional fishing and hunting rights.
A pocket borough? Reformed politics in Ripon, 1832-67

This article examines the political history of the parliamentary borough of Ripon between the Great Reform Act of 1832 and the Second Reform Act of 1867. It challenges the notion that Ripon remained a ‘pocket borough’ during this era; rather, the Reform Act rendered Ripon’s politics much more open, vibrant and participatory than they had been during the ‘unreformed’ era. In demonstrating this, the article calls into question the alleged prevalence of ‘pocket boroughs’ in the reformed era.
The Role of Radiation in the Perioperative Treatment of Esophagogastric Cancer

Cancers of the esophagus, stomach, and the esophagogastric junction (EGJ) remain a global health problem. There has been a dramatic increase in the incidence of adenocarcinoma of the distal esophagus and EGJ in the past two decades with little change in the poor prognosis associated with these cancers. Previously surgery alone was the mainstay of therapeutic intervention, but high rates of local and systemic failure have prompted investigation into neoadjuvant and adjuvant therapy. Treatment paradigms differ across continents, but the unifying theme that has emerged in the past decade implies that surgery alone can no longer be considered the standard of care. The multi-disciplinary management of patients with locally advanced esophagogastric carcinomas using trimodality therapy with radiotherapy, chemotherapy, and surgery confers the greatest opportunity for margin negative resection, improved loco-regional control and cure, and should be the accepted treatment paradigm. The traditional backbone of platinum plus fluorouracil concurrent with radiotherapy may be supplanted by more modern, easier-to-administer regimens incorporating taxanes and irinotecan. The current generation of clinical trials in this heterogeneous group of diseases is examining targeted therapy, newer methods of radiotherapy, and predictors of response to therapy aiming to tailor management to an individual patient.
A step back as donors shift institution building from the public to the “private” sector

Abstract Frustrated with public sectors in developing countries, donors have shifted support to nonprofit nongovernmental organizations. This paper questions the preferability of the nonprofit or public sector from the donor and host country perspectives. Case study experience from agriculture and natural resource institutions in Ecuador and the Dominican Republic is presented to expand upon current thinking about the role of the nonprofit sector. Nonprofits are found to possess substantially increased flexibility for donor purposes and avoid many of the pitfalls of the political process. They are, however, subject to free-rider problems and bear no responsibility to the general public.
Role of Toll-Like Receptors in Changes in Gene Expression and NF-κB Activation in Mouse Hepatocytes Stimulated with Lipopolysaccharide

The liver is an important site of host-microbe interaction. Although hepatocytes have been reported to be responsive to lipopolysaccharide (LPS), the global gene expression changes by LPS and mechanism(s) by which LPS stimulates cultured hepatocytes remain uncertain. Cultures of primary mouse hepatocytes were incubated with LPS to assess its effects on the global gene expression, hepatic transcription factors, and mitogen-activated protein (MAP) kinase activation. DNA microarray analysis indicated that LPS modulates the selective expression of more than 80 genes and expressed sequence tags. We have shown previously that hepatocytes express CD14, which is required both for uptake and responsiveness to LPS. In other cells, responsiveness to microbial products requires expression of Toll-like receptors (TLR) and their associated accessory molecules. Hepatocytes expressed TLR1 through TLR9 as well as MyD88 and MD-2 transcripts, as shown by reverse transcriptase PCR analysis, indicating that hepatocytes express all known microbe recognition molecules. The MAP kinase extracellular signal-regulated kinase 1/2 was phosphorylated in response to LPS in mouse hepatocytes, and the levels of phosphorylation were lower in hepatocytes from TLR4-null mice. NF-κB activation was reduced in TLR4-mutant or -null hepatocytes compared to control hepatocytes, and this defect was partially restored by adenoviral transduction of mouse TLR4. Thus, hepatocytes respond to nanogram concentrations of LPS through a TLR4 response pathway.
A combined experimental and theoretical study of resonance emission spectra of SO2(C̃)

Abstract Experimental and theoretical resonance emission spectra are obtained for a number of vibrational states of SO 2 (C 1 B 2 ). The experimental emission spectra are dominated by ( n 1 ν 1 , n 2 ν 2 , 0) bands, but some weak activity in the anti-symmetric stretch ( ν 3 ) is observed. The calculated emission spectra based on an empirical near-equilibrium potential energy surface agree reasonably well with experiment for two lowest states investigated here, but fail to reproduce higher ones. Resonance Raman spectra are also calculated and agree well with an earlier experiment.
Intermodal nonlinear mixing with Bessel beams in optical fiber

Nonlinear frequency mixing as a means to coherently convert light to new frequencies is widely used in many branches of optics. This process requires momentum conservation through phase matching (PM). In free-space optics, PM is achieved through angle tuning the medium with respect to the incoming light—here we explore an in-fiber analogue: PM using spatial modes of the fiber. We demonstrate over two octaves (400–1700 nm) of coherent spectral translation generated by intermodal four-wave mixing between subsets of 11 different Bessel-like fiber modes. These interactions are facilitated by the unique mode-coupling resistance of this subset of azimuthally symmetric, zero orbital angular momentum fiber modes. Their stability allows overcoming previous limitations of multimode nonlinear-optical systems imposed by mode coupling, hence enabling long interaction lengths, large effective mode areas, and a highly multimode basis set with which a new degree of freedom for versatile PM can be obtained.
Further aspects of the differential capacitance of iron

Abstract The differential capacitance of high purity zone-refined iron was measured using a single pulse technique. Capacitance behaviour in dilute solutions of sodium perchlorate showed that an unambiguous assignment of a value to the pzc is not possible from the capacitance minima. Measurements in sodium halides showed a different behaviour with I− than with F−, Cl− and Br−. Electrode capacitance in an aqueous solution of furoic-acid-sodium-furoate buffer was determined over 300 mV on either side of the open-circuit potential. The effect of specifically adsorbed furoate ions on the morphology of the capacitance curves is very striking.
Using OpenFlow to provide cut-through switching in MobilityFirst

Mobile devices are expected to become the Internet's predominant technology. Current protocols such as TCP/IP were not originally designed with mobility as a key consideration, and therefore underperform under challenging mobile and wireless conditions. MobilityFirst, a clean slate architecture proposal, embraces several key concepts centered around secure identifiers that inherently support mobility and trustworthiness as key requirements of the network architecture. This includes a hop-by-hop segmented data transport based on a globally unique identifier. This allows late and dynamic rebinding of end-point addresses to support mobility. While this provides critical gains in wireless segments, some overheads are incurred even in stable segments such as in the core. Bypassing routing-layer decisions in these cases, with lower layer cut-through forwarding, can improve said gains. In this work, we introduce a general bypass capability within the MobilityFirst architecture that provides better performance and enables both individual and aggregate flow-level traffic control. Furthermore, we present an OpenFlow-based proof-of-concept implementation of the bypass function using layer 2 VLAN tagging. We run experiments on the ORBIT and Global Environment for Network Innovations (GENI) testbeds to evaluate the performance and scalability of the solution. By implementing the bypass functionality, we are able to significantly reduce the number of messages processed by the controller as well as the number of flow rules that need to be pushed into the switches.
Inversion behavior in core- and cladding-pumped Yb-doped fiber photodarkening measurements

Yb-doped fibers are widely used in applications requiring high average output powers and high power pulse amplification. Photodarkening of the Yb-doped silicate glass core potentially limits the lifetime or efficiency of such fiber devices. In many studies of photodarkening, two principal methods of controllably inducing an inversion are used, namely, cladding pumping and core pumping of the sample. We present simulation results describing the key differences in the inversion profiles of samples of different physical parameters in these two cases, and we discuss the problems and possibilities that arise in benchmarking fibers of various physical parameters. Based on the simulation and experimental work, we propose guidelines for photodarkening benchmarking measurements and show examples of measurements made within and outside of the guidelines.
Reduction of a Finite Volume Model for Control of the Solidification Front in a Remelting Process

Remelting is used in the production of superalloy ingots. In these processes, stabilization of the solidification front is crucial in the prevention of segregation defects. However, models that account for solidification dynamics often are distributed-parameter multi-physics models that are not used in process control due to their complexity. This paper outlines model reduction for a remelting process based on a multi-physics finite volume model. A reduced-order model is constructed from a state-space realization where only transport phenomena are included. Balancing-free square-root singular perturbation approximation is used to construct a minimal reduced system, and then modal residualization is performed to remove modes that lie outside of the bandwidth of the actuators. The obtained reduced-order model was used to design an LQG controller. Simulation results verify that using the proposed reduced-order model for estimation and control can result in more accurate solidification control, when compared to a simplified model that accounts only for thermal processes.Copyright © 2014 by ASME
Modelos locales de densificación según gradientes territoriales de habitabilidad en conurbación interior, Valparaíso-Viña, Rodelillo Alto

This paper discusses the growth and spontaneous density at the edge of the city of Valparaiso, Rodelillo sector, close to the conurbation in Vina del Mar. Criteria are proposed to study aspects as well as the territory’s own local conditions regarding the use and socio-cultural assimilation, whose interaction determines the densification processes and vernacular growth occurring there, raising the notion of gradient as a unifying basis for identifying and studying possible zoning. Facts such as the fire of February 2013, in the adjacent sector to the study area, reinforce the need for local models that consider the interaction of morphological variables such as wind, territory and local population densification. In the particular case of the Rodelillo sector at least five types of areas can be identified, articulated in a clear and direct territorial gradient expressed in local cartographies. This organized diversity can guide the development of local building and densification models.
The Chemistry of TALSPEAK: A Review of the Science

The TALSPEAK Process (Trivalent Actinide Lanthanide Separation with Phosphorus-Reagent Extraction from Aqueous Komplexes) was originally developed at Oak Ridge National Laboratory by B. Weaver and F.A. Kappelmann in the 1960s. It was envisioned initially as an alternative to the TRAMEX process (selective extraction of trivalent actinides by tertiary or quaternary amines over fission product lanthanides from concentrated LiCl solutions). TALSPEAK proposed the selective extraction of trivalent lanthanides away from the actinides, which are retained in the aqueous phase as aminopolycarboxylate complexes. After several decades of research and development, the conventional TALSPEAK process (based on di-(2-ethylhexyl) phosphoric acid (extractant) in 1,4-di-isopropylbenzene (diluent) and a concentrated lactate buffer containing diethylenetriamine-N,N,N’,N”,N”-pentaacetic acid (actinide-selective holdback reagent)) has become a widely recognized benchmark for advanced aqueous partitioning of the trivalent 4f/5f e...
Free trees and bidirectional trees as representations of psychological distance

Abstract Two types of graph-theoretic representations of psychological distances or dissimilarities are proposed: weighted free trees and weighted bidirectional trees. A weighted free tree is a generalization of the sort of graph representation used in hierarchical clustering. A weighted bidirectional tree is a further generalization which allows for asymmetric dissimilarities. The properties of these structures are discussed and numerical methods are presented that can be used to derive a representation for any given set of dissimilarities. The applicability of these structures is illustrated by using them to represent the data from experiments on the similarities among animal terms and on memory for sentences. An analysis based upon free trees is compared and contrasted with analyses using hierarchical clustering and multidimensional scaling.
Bayesian analysis. V : Amplitude estimation for multiple well-separated sinusoids

Abstract Bayesian probability theory is used to estimate the amplitude of multiple well-separated exponentially decaying sinusoids in NMR free-induction-decay data. Specifically the posterior probability for the amplitude is derived independent of the phase, frequency, decay rate constant, and variance of the noise. The estimate is shown to be accurate and precise in the sense that as the noise approaches zero, the estimate approaches the true value of the amplitude and the uncertainty in the estimate approaches zero. For fixed data-acquisition time, the uncertainty in the estimate is shown to vary inversely with the square root of the sampling rate. Finally, the calculation is applied in two examples. The first example demonstrates the ability of probability theory to estimate frequencies and amplitudes in very low signal-to-noise. The second example illustrates the use of this calculation when the data contain multiple, well-separated sinusoids.
The Gauss—Markov Theorem and Random Regressors

Abstract In the standard linear regression model with independent, homoscedastic errors, the Gauss—Markov theorem asserts that = (X'X)-1(X'y) is the best linear unbiased estimator of β and, furthermore, that is the best linear unbiased estimator of c'β for all p × 1 vectors c. In the corresponding random regressor model, X is a random sample of size n from a p-variate distribution. If attention is restricted to linear estimators of c'β that are conditionally unbiased, given X, the Gauss—Markov theorem applies. If, however, the estimator is required only to be unconditionally unbiased, the Gauss—Markov theorem may or may not hold, depending on what is known about the distribution of X. The results generalize to the case in which X is a random sample without replacement from a finite population.
Increased resistance to punishment produced by adaptation to a cold stressor.

Abstract In order to examine the relationship between physiological adaptation and behavioral responses, groups of rats received daily brief immersion exposures in 10°C or 35°C water, or restraint without immersion. Following seven days of treatment, behavioral testing commenced. Subjects had to traverse a cold water barrier in a straight alley in order to reach the goal box. As measured by running speed or percentage of completed approaches, cold adapted subjects were less disrupted and warm water exposed rats were more disrupted by punishment than controls. These findings support the view that physiological modifications, produced independently of the behavioral situation, can subsequently alter the resistance to punishment.
Vitrectomy for nondiabetic vitreous hemorrhage. Retinal and choroidal vascular disorders

The results and complications of pars plana vitrectomy for nondiabetic vitreous hemorrhage due to retinal and choroidal vascular disorders were studied in 68 eyes of 66 patients. Diagnoses included: retinal branch vein obstruction (34 eyes), choroidal neovascularization (15 eyes), central retinal vein occlusion (5 eyes), Eales' disease (10 eyes), pars planitis (3 eyes), and hemoglobin S-C retinopathy (1 eye). The duration of the vitreous hemorrhage was 6 months or more in 48 eyes (71%), and averaged 17.8 months. Preoperative visual acuity was less than 5/200 in 57 eyes (84%). Best postoperative visual acuity was 5/200 or better in 55 patients (81%), and vision improved two or more lines after vitrectomy in 54 eyes (80%). Patients with retinal branch vein obstruction, Eales' disease, or pars planitis had the best prognosis. Those with central retinal vein obstruction or choroidal neovascularization had the worst prognosis.
Plasmid expression vector using the lambda late promoter

Abstract A plasmid expression vector called pQTE1 based on the late promoter, pR′, and positive control gene Q of bacteriophage lambda has been constructed. This vector has unique cloning sites for placing exogenous DNA under control of pR′. Induction of expression of genes cloned into the pQTE1 plasmid leads to massive overproduction of the gene products. Also, transcription from the pR′ promoter on pQTE1 appears to be insensitive to polarity effects.
Silicon micromachining to tissue engineer branched vascular channels for liver fabrication

To date, many approaches to engineering new tissue have emerged and they have all relied on vascularization from the host to provide permanent engraftment and mass transfer of oxygen and nutrients. Although this approach has been useful in many tissues, it has not been as successful in thick, complex tissues, particularly those comprising the large vital organs such as the liver, kidney, and heart. In this study, we report preliminary results using micromachining technologies on silicon and Pyrex surfaces to generate complete vascular systems that may be integrated with engineered tissue before implantation. Using standard photolithography techniques, trench patterns reminiscent of branched architecture of vascular and capillary networks were etched onto silicon and Pyrex surfaces to serve as templates. Hepatocytes and endothelial cells were cultured and subsequently lifted as single-cell monolayers from these two-dimensional molds. Both cell types were viable and proliferative on these surfaces. In addit...
Satisfaction with upper-extremity surgery in individuals with tetraplegia.

Abstract Wuolle KS, Bryden AM, Peckham PH, Murray PK, Keith M. Satisfaction with upper-extremity surgery in individuals with tetraplegia. Arch Phys Med Rehabil 2003;84:1145–9. Objective: To measure the satisfaction of individuals with tetraplegia with their upper-extremity reconstructive surgery. Design: Survey. Setting: Two Spinal Cord Injury Model Systems centers. Participants: Sixty-seven individuals with spinal cord injury at the C4 through C8 motor level (107 arms). Interventions: Participants had upper-extremity surgery to improve function. The surgical procedures included tendon transfers for elbow extension, wrist extension, hand grasp, and pinch or hand grasp neuroprosthesis. Main Outcome Measure: A survey was mailed to participants, who were asked to respond to statements such as, "If I had it to do over, I would have the hand/arm surgery again," using a 5-level Likert scale (ranging from strongly agree to strongly disagree). Results: Seventy percent of the participants were generally satisfied with the results of their upper-extremity surgery, 77% reported a positive impact on their lives, 68% reported improvements in activities of daily living (ADLs), 66% reported improved independence, 69% reported improvement in occupation, 71% reported improved appearance or neutral, 78% reported their hand worked as well (or neutral) as it did when surgery was first performed, and 86% reported postoperative therapy as being beneficial. Conclusions: Upper-extremity surgery had a positive impact on life, increased ability to perform ADLs and to be independent, and improved quality of life.
Flux-Corrected Transport looks at forty

Abstract This year, 2013, marks the 40th anniversary of the journal article “Flux-Corrected Transport I. SHASTA, A Fluid Transport Algorithm That Works” by Jay Boris and David Book [1] . Flux-Corrected Transport (FCT) removed a serious roadblock to advances in Computational Fluid Dynamics (CFD) by enabling the accurate treatment of strong, time-dependent shock problems in blast, reactive-flow, and combustion physics, and in aerodynamics and astrophysics. Steep gradients in conserved fluid variables could now be convected across a computational grid without the appearance of spurious oscillations and physically impossible negative values. The nonlinear “flux-correction” algorithm introduced in FCT imposes the physical properties of conservation, locality, causality, and monotonicity on the numerical solutions for convection without adding a great deal of numerical diffusion. This article shows that implementing these physical properties in solving the continuity equation through high-resolution FCT also results in a serviceable Large-Eddy Simulation treatment of turbulent flows without need for additional “subgrid turbulence models.” We have named this simplified approach Monotone Integrated Large Eddy Simulation (MILES).
Parallel optical control of spatiotemporal neuronal spike activity using high-speed digital light processing.

Neurons in the mammalian neocortex receive inputs from and communicate back to thousands of other neurons, creating complex spatiotemporal activity patterns. The experimental investigation of these parallel dynamic interactions has been limited due to the technical challenges of monitoring or manipulating neuronal activity at that level of complexity. Here we describe a new massively parallel photostimulation system that can be used to control action potential firing in in vitro brain slices with high spatial and temporal resolution while performing extracellular or intracellular electrophysiological measurements. The system uses Digital-Light-Processing (DLP) technology to generate 2-dimensional (2D) stimulus patterns with >780,000 independently controlled photostimulation sites that operate at high spatial (5.4 µm) and temporal (>13kHz) resolution. Light is projected through the quartz-glass bottom of the perfusion chamber providing access to a large area (2.76 x 2.07 mm2) of the slice preparation. This system has the unique capability to induce temporally precise action potential firing in large groups of neurons distributed over a wide area covering several cortical columns. Parallel photostimulation opens up new opportunities for the in vitro experimental investigation of spatiotemporal neuronal interactions at a broad range of anatomical scales.
Knowledge and the Norms of Assertion

An account of the norms of assertion is proposed which is supported by the same considerations that motivate the familiar knowledge account of those norms, but does not have a problematic consequence of the latter. This alternative account is defended against others to be found in the literature, and some larger epistemological issues it raises are considered briefly.
Modeling the observer in target acquisition

Models of target acquisition by human observers are probabilistic. Two reasons for the indeterminate nature of the models are (1) the observer ensemble includes individuals with varying levels of competence in target acquisition, and (2) the target acquisition process is itself (at least in part) a random process. Each of the two commonly used combat simulations, CASTFOREM and JANUS, assumes that (a different) one of these completely accounts for the indeterminacy, and ignores the other. While the distinction is irrelevant for the simple one-on-one case, it has recently been shown that the choice can affect the outcomes of more realistic many-on-many engagements. We propose a model in which target detection probability is a function of both a target statistic and an observer statistic. Our analysis of recently compiled observer test data validates the model and provides it with the correct quantitative balance between variations among observers and the inherently stochastic component of target acquisition.
Enzyme-linked Immunoassay for Respiratory Syncytial Virus Is Not Predictive of Bronchiolitis in Sudden Infant Death Syndrome

Although respiratory syncytial virus (RSV)-infected infants may present with apnea, the role that RSV plays in sudden infant death syndrome (SIDS) is speculative. To determine whether RSV is associated with bronchiolitis in these patients, we examined histologic sections of lungs from 41 apparent SIDS cases and compared the results with those of enzyme-linked immunofluorescent assay (EIA) from nasal washings. Bronchiolitis was defined by a bronchiolar inflammatory cell infiltrate plus epithelial necrosis. A positive EIA was associated with bronchiolitis in 8 instances, compared with 6 having a positive EIA and negative histology, 14 having a negative EIA and positive histology, and 13 having EIA and histology both negative. These results yield a predictive value of a positive test of 57% and a predictive value of a negative test of 48% (P > .9 by chi square analysis). Although RSV of the upper respiratory tract may be related to SIDS, our results indicate that EIA of nasal washings is not predictive of bronchiolitis, and we recommend other means of verification of histologic results.
Morphology and Field-Effect Mobility of Charge Carriers in Binary Blends of Poly(3-hexylthiophene) with Poly[2-methoxy-5-(2-ethylhexoxy)-1,4-phenylenevinylene] and Polystyrene

Two series of binary blends of regioregular poly(3-hexylthiophene) (PHT) with a polymer semiconductor, poly[2-methoxy-5-(2-ethylhexoxy)-1,4-phenylenevinylene] (MEH−PPV), and with an insulating polymer, polystyrene, were investigated and found to be phase separated and to exhibit relatively high field-effect mobility of holes ((0.1−6) × 10-3 cm2/(V s)). Atomic force microscopy showed nucleation and growth type phase separation on the length scale of 100−600 nm in the binary blend systems. The mobility of holes in PHT/polystyrene blends is up to 7-fold higher than in PHT/MEH−PPV blends. The reduced carrier mobility in the PHT/MEH−PPV blends is due to dipolar effects arising from the polarity of the components. These results show for the first time that dipolar effects can substantially modify the charge transport properties of blends of conjugated polymers.
Magnetic susceptibility and Faraday rotation in zirconium based fluoride glasses

The temperature dependences of the d.c. magnetic susceptibility and Verdet constant in two zirconium based fluoride glasses have been studied. One sample has as a minor constituent dysprosium which has a large magnetic moment that dominates the material's magnetic character. The second sample, containing a small amount of europium, shows both Van Vleck paramagnetism and a Curie-Weiss behaviour. The Curie-Weiss character is believed to come from small amounts of and/or produced during the sample's manufacturing process. An upper limit is placed on the amount of magnetic zirconium in the material.
SU-E-T-102: Factors That Affect the Accuracy of IMRT Quality Assurance Measurements and Their Clinical Significance

Purpose: The purpose of this work was to perform error analysis on various processes that directly affect the accuracy of quality assurance (QA) measurements for intensity modulated radiation therapy(IMRT)delivery and to gauge their overall clinical impact for various clinical sites. Methods: In this study, we developed a numerical model based on the propagation of errors to quantify the complexity of treatment plans by the level of the intensity of modulation, and correlated the level of the modulation directly to the agreement of the IMRT QA results. We also provide detailed analysis of the uncertainties from IMRT QA results stratified by treatment site specific plans and fidelity in plan delivery. Results: Using a 5%/2mm criterion, it was found that the level of agreement of IMRT QA measurements was better for pelvic and chest plans than for head and neck, breast and brain plans. Errors tended to first increase with an increase in the number of Multi‐leaf Collimator(MLC) segments from 5 to 20 and then decrease with further increase in the number of segments. It was determined that other factors that impact the accuracy of the measurements include measurement device limitations, machine output variations, and phantom setup errors. Similarly, uncertainties in the beam data modeling and the calculation algorithm, as well as the initial beam commissioning data are main contributing factors to the accuracies of the treatment planning systems. Conclusions: The overall agreement of IMRT QA results is affected by both ‐ the accuracy of the measurement and that of the treatment planning system. We will demonstrate that the IMRT QA analysis criteria currently used in many clinics can be modified and improved to reflect the uncertainties of the process using the error propagation model developed in this study.
Applications of Ali-Silvey Distance Measures in the Design Generalized Quantizers for Binary Decision Systems

The Ali-Silvey class of distance measures is applied to the problem of designing quantizers for use in binary detection systems. To find optimal solutions the notion of quantization must be generalized slightly, and necessary conditions are established for the selection of quantizer parameters in this context. Local, or small-signal, conditions are also derived and these are seen to agree with asymptotic results based on Pitman efficiency. As an example, four-level generalized quantization for detecting a constant signal in additive generalizedGaussian noise is investigated.
A Discourse on Semantic Priming

Abstract The processing of a word is sometimes affected if earlier words are semantically related to it (semantic “priming”). Priming phenomena have generally been interpreted as reflecting the organization of the mental lexicon. Past studies have shown that priming effects have a very fast rise time and a relatively rapid decay time. This paper investigates the rate of decay of semantic facilitation in both sentences and lists. It was hypothesized that sentence processing involves the construction of a discourse model in which the main topics stay active. If true, then words referring to related objects or events will be processed rapidly even if they occur later in the input, i.e., there will be no decay of facilitation. Three experiments with college students examined the relative time to process a critical word when it was preceded by either a pair of semantically related words or more neutral words. The materials occurred in either sentences or lists, the latter being word-level anagrams of the sentences. Subjects carried out the phonememonitoring task, responding to a word-initial target phoneme that occurred immediately after the critical word. In Experiments I (N = 58) and II (N = 40) 12 words separated the related/neutral words and the critical items. Facilitation in processing the critical word was present in sentences but not in lists. Experiment III (N = 128) showed that the amount of facilitation in sentences was the same when 12 words separated the related/neutral and critical words as when 1.5 words separated them. Thus, there was no evidence obtained here for decay of facilitation in sentences. The results are taken to be consistent with a discourse-model interpretation of semantic facilitation in sentences.
COMMENT ON :THERMOCAPILLARY BUBBLE MIGRATION AT HIGH REYNOLDS AND MARANGONI NUMBERS UNDER LOW GRAVITY

Abstract This article proposes that the experimental data associated with Treuner et al. (Treuner, M., Galindo, V., Gerbeth, G., Langbein, D., and Rath, H. J., J. Colloid Interface Sci. 179, 114 (1996)) indicates that a secondary oscillation may exist for bubble motion due to thermocapillary effects in a low gravity environment. This oscillation in the velocity appears to have a frequency of about 4 Hz for a 2.0-mm bubble in octane with a temperature gradient of about 0.56°C/mm.
Some Results Concerning the Crossover Behavior of Quasi—Two-Dimensional and Quasi—One-Dimensional Systems

A magnetic system with intraplanar and interplanar interaction strengths $J$ and $\mathrm{RJ}$ is is treated. Rigorous relations are established concerning the first few derivatives with respect to $R$ of the susceptibility $\ensuremath{\chi}(R)$. Considering $\ensuremath{\chi}(R)={b}_{0}+{b}_{1}R+{b}_{2}{R}^{2}+\ensuremath{\cdots}$, we find ${b}_{1}$ and the order of magnitude of ${b}_{2}$. Hence we can predict when the system "crosses over" from $d$-dimensional to $d$-dimensional behavior (e.g., for quasi---two-dimensional systems, $d=2$, $\overline{d}=3$, while for quasi---one-dimensional systems, $d=1$, $\overline{d}=3$). These results also support scaling with respect to the anisotropy parameter $R$.
Nader's Support: Its Sources and Concerns

Do the consumer advocates, such as Nader, have a real constituency? Where do they get their support? This study, based on a nationwide sample, investigated the extent of support for Ralph Nader and his program, and its sources. Nader was found to have substantial support, a major portion of it consisting of middle-income political liberals. Those supporting Nader were found to be active complainers and supporters of other political and social causes, suggesting that support for Nader is part of a broader pattern of activisim.
Anthropogenic trace elements and polycyclic aromatic hydrocarbon levels in sediment cores from two lakes in the Adirondack acid lake region

Sediment cores were taken from the remote Sagamore and Woods Lakes in New York State's Adirondack acid lake region and analyzed for 3 to 7 ring polycyclic aromatic hydrocarbons (PAHs) and Ag, Al, As, Be, Cd, Cr, Cu, Hg, Ni, Ph, Se, Sn, TI, V, and Zn. With the exception of perylene, all of the parental PAHs, e.g. those without sidechains, and several of the metals, Pb, As, and Cd, were found to be significantly increased in the sediments of both lakes compared to their natural integrated deposits (ng cm−2) and their background concentrations (μg g−1 or ng g−1 dry wt). Although the concentrations were generally much higher in Woods Lake, the total anthropogenic integrated depositions were about the same in both lakes for most of the metals and the 3 to 4 ring PAHs. The prime source of most of the 3 to 7 ring PAHs and trace elements measured is ascribed to anthropogenic combustion. Anthropogenically derived materials decreased in concentration with depth to baseline levels in sediment layers estimated by137Cs analyses to be ∼30 yr old, while biogenic or crustal derived species remained constant or fluctuated with core depth.
Inhibition of proliferation in human MNNG/HOS osteosarcoma and SK-ES-1 Ewing sarcoma cell lines in vitro and in vivo by antagonists of growth hormone-releasing hormone: effects on insulin-like growth factor II.

BACKGROUND Antagonists of growth hormone-releasing hormone (GH-RH) can inhibit the proliferation of various tumors either indirectly through the suppression of the pituitary growth hormone/hepatic insulin-like growth factor I (IGF-I) axis and the lowering of serum IGF-I concentration or directly by reducing the levels of IGF-I and IGF-II and their mRNA expression in tumors and blocking the effect of autocrine GH-RH. In this study, the authors investigated the effects of the GH-RH antagonist JV-1-38 on MNNG/HOS human osteosarcoma and SK-ES-1 human Ewing sarcoma cell lines. METHODS Male nude mice bearing subcutaneous xenografts of MNNG/HOS or SK-ES-1 tumors were treated subcutaneously with JV-1-38 at a dose of 20 μg twice daily for 4 weeks. The concentrations of IGF-I and IGF-II in serum and in tumor tissue were measured by radioimmunoassay. Tumor and liver levels of mRNA for IGF-I and IGF-II were determined by reverse transcriptase-polymerase chain reaction analysis. The effects of JV-1-38, IGF-I, and IGF-II on cell proliferation in vitro were evaluated. RESULTS GH-RH antagonist significantly (P 50% after 4 weeks and increased tumor doubling time. JV-1-38 lowered the serum IGF-I level, decreased the expression of mRNA for IGF-I in the liver, and significantly (P < 0.05–0.01) reduced the concentration of IGF-II and mRNA levels for IGF-II in both sarcomas. The concentration of IGF-I was lowered only in SK-ES-1 tumors. In vitro, the proliferation of SK-ES-1 and MNNG/HOS cells was inhibited by JV-1-38 and by antisera to IGF-I and IGF-II. CONCLUSIONS The inhibition of MNNG/HOS osteosarcoma and SK-ES-1 Ewing sarcoma by GH-RH antagonists was linked to a suppression of IGF-II production in tumors. However, in SK-ES-1 tumors, the effects on IGF-I also may be involved. Cancer 2002;95:1735–45. © 2002 American Cancer Society. DOI 10.1002/cncr.10865
Kβ X-ray Emission Spectroscopy Offers Unique Chemical Bonding Insights: Revisiting the Electronic Structure of Ferrocene

Kβ X-ray emission spectroscopy (XES) is emerging as a powerful tool for the study of chemical bonding. Analyses of the Kβ XES of ferrocene (Fc) and ferrocenium (Fc(+)) are presented as further demonstrations of the capabilities of the technique. Assignments of the valence to core (V2C) region of these spectra as electric dipole-allowed cyclopentadienyl (Cp) → Fe 1s transitions demonstrate that XES affords electronic structural insight into the energetics of ligand-based molecular orbitals (MOs). Combined with K-edge X-ray absorption spectroscopy (XAS), we show that XES can provide analogous information to photoemission spectroscopy (PES). Density functional theory (DFT) analyses reveal that the V2C transitions in Fc/Fc(+) derive their intensity from Fe 4p admixture (on the order of 5-10%) into the Cp-based MOs from which they originate. These 4p admixtures confer bonding character to the Cp-based a(2u) and e(1u) MOs to at least the extent of backbonding contributions to frontier MOs from higher-lying Cp π* MOs.
Clustered Adaptation for Estimation of Time-Varying Underwater Acoustic Channels

In this paper, we present a sparse channel estimator that exploits channel coherence across blocks for orthogonal frequency division multiplexing (OFDM) in underwater acoustic (UWA) transmissions. We propose a novel channel variation model that the channel paths within a cluster share the same amplitude, delay, and Doppler scale variations from one block to the next, but different clusters vary independently. The variation offsets for different clusters are estimated based on the measurements on the pilot subcarriers of the current block. A hybrid channel estimator is developed that can effectively utilize both the channel knowledge from the previous block and the pilot observations of the current block. Performance results based on collected data from two experiments demonstrate that adaptation with multiple clusters outperforms that with one cluster, and that the proposed cluster-adaptation based channel estimator significantly improves the system performance relative to the pilot-based counterpart.
Near-field microwave non-invasive determination of NaCl in mortar

In recent years near-field microwave nondestructive testing and evaluation techniques have shown great promise for evaluating different properties of cement-based structures. An important issue regarding the inspection of these structures is the ability to determine the presence and evaluate the content of chloride in them. Chlorides can be introduced in these structures in many different ways including when salts are present in their mixing water. Consequently, for this investigation, two sets of 8"/spl times/8"/spl times/8" (203 mm) cubic mortar specimens were prepared each with a water-to-cement (w/c) ratio of 0.5 and 0.6, respectively, and both sets with sand-to-cement ratios of (s/c) of 1.5. Four specimens were produced for each set with different salt (NaCl) contents added to the mixing water, producing salt-to-cement (NaCl/c) ratios of 0.0, 1, 2 and 3%, respectively. For the purpose of compressive strength measurement, cylindrical specimens of these mortar specimens were also prepared and tested for their compressive strength. Microwave reflection properties of these specimens were measured at S-band (2.6-3.95 GHz) and X-band (8.2-12.4 GHz), employing open-ended rectangular waveguide probes. It is shown that the magnitude of reflection coefficient is a useful parameter for detecting different chloride levels in these specimens. Moreover, the influence of chloride on the curing properties (i.e. setting time) and the compressive strength of these specimens are subsequently shown to be well correlated to the measured magnitude of reflection coefficient of these specimens at S-band. It is also shown that this correlation is unambiguous as a function of w/c which possesses significant practical ramifications.
The intracellular and membrane effects of oxidant agents on normal red cells.

Summary. Oxidant drugs produced different patterns of oxidative change in red cell GSH and haemoglobin. Naphthoquinones were associated with a marked increase in methaemoglobin, a marked decrease in GSH and the ready formation of Heinz bodies. Phenylhydrazine, at the lower concentrations, produced Heinz bodies while methaemoglobin levels were only minimally increased and GSH levels unchanged. p-Aminophenol markedly increased the concentration of methaemoglobin while decreasing that of GSH but formed no Heinz bodies. With hydroquinone, GSH was virtually depleted before small amounts of methaemoglobin were produced. Membrane damage as measured by a loss of red cell K+ and haemolysis in hypotonic saline was only found with 1,4-naphthoquinone, β-naphthol and the antimalarial drugs. These compounds produced abnormal osmotic fragility curves which differed one from the other. Membrane injury occurred in the presence and absence of intracellular oxidative change. These studies demonstrate marked differences in the intracellular and membrane actions of oxidant agents.
Coevolutionary genetics of hosts and parasites with quantitative inheritance

A model of host—parasite coevolution is analysed. A host resistance trait and a parasite virulence trait interact to determine the outcome of a parasitic attack, where each trait is determined by quantitative genetic variation. The resistance and virulence traits are assumed to have a fitness cost. Each host and parasite genotype is treated as a separate ‘species’ in a multidimensional Lotka—Volterra system in which the numerical abundance of each genotype is free to change. Thus, the epidemiological effects of fluctuating population sizes are analysed jointly with changes in genotype frequencies. Population sizes fluctuate increasingly as the parasites' reproductive capacity increases and as resistance and virulence benefits per unit cost decline. The patterns of genetic variability depend mainly on the stability of population sizes and on the shape of the relationship between the costs and benefits of a trait.