cssi/SciSciGPT-SciSciNet huggingface dataset:
The Polycomb protein RING1B enables estrogen-mediated gene expression by promoting enhancer–promoter interaction and R-loop formation

Polycomb complexes have traditionally been prescribed roles as transcriptional repressors, though increasing evidence demonstrate they can also activate gene expression. However, the mechanisms underlying positive gene regulation mediated by Polycomb proteins are poorly understood. Here, we show that RING1B, a core component of Polycomb Repressive Complex 1, regulates enhancer-promoter interaction of the bona fide estrogen-activated GREB1 gene. Systematic characterization of RNA:DNA hybrid formation (R-loops), nascent transcription and RNA Pol II activity upon estrogen administration revealed a key role of RING1B in gene activation by regulating R-loop formation and RNA Pol II elongation. We also found that the estrogen receptor alpha (ERα) and RNA are both necessary for full RING1B recruitment to estrogen-activated genes. Notably, RING1B recruitment was mostly unaffected upon RNA Pol II depletion. Our findings delineate the functional interplay between RING1B, RNA and ERα to safeguard chromatin architecture perturbations required for estrogen-mediated gene regulation and highlight the crosstalk between steroid hormones and Polycomb proteins to regulate oncogenic programs.
An ESCRT to seal the envelope

Metazoan cells divide by “open” mitosis, in which disassembly of the nucleus allows microtubules of the mitotic spindle to access kinetochores, proteinaceous structures that associate with specialized regions of chromosomes called centromeres. Duplicated chromosomes align on the spindle, and as they segregate toward opposite ends of the dividing cell, nuclear membrane reassembly initiates ( 1 ). This requires recruiting membrane, reconstituting nuclear pores, and severing microtubule connections between chromosomes and the spindle organizing centers (centrosomes). The nuclear envelope must seal to reestablish proper separation of the genome from the cytoplasm, but just how the nuclear membrane closes and overcomes the physical roadblocks presented by spindle microtubules has been unclear. Recent studies ( 2 , 3 ) now demonstrate that the endosomal sorting complex required for transport (ESCRT) membrane fission machinery orchestrates this mysterious process.
Surgical Treatment of Rectal Prolapse: Rectopexy without Mesh

More than 150 years have elapsed since the first report on full-thickness rectal prolapse (FTRP) surgery appeared in the literature [1]. Yet, no adequately powered randomized trials have been published on surgical treatment of FTRP. The title of this chapter emphasizes how rectopexy can be performed without a mesh rather than affirming that it can be done with sutures. This chapter represents a current opinion on the impact that suture rectopexy may have on the outcomes of care of FTRP; however, the chapter provides no systematic review of the evidence available in the literature. The objective is to present a concise insight on surgical technique, the authors’ personal experience, and an overview of the literature dealing with this specific subject.
Vector Weights and Dual Graphs: An Emphasis on Connections in Brain Network Analysis

Graph theoretical representations of the brain as a complex network give a special emphasis to anatomical or functional units of the gray matter. These units are abstracted as the nodes of a graph and are pairwise connected by edges that embody a notion of connectivity. Graph theoretical operations in brain network analysis are typically employed to reveal organizational principles of the network nodes. At the same time, relatively little attention has been given to connection properties and the relations between them. Yet, various neuroscientific applications place an increased importance on connections and often require a characterization by multiple features per connection. It is not clear, however, how to incorporate vector edge weights in the standard graph representation. In this paper, we present a novel Dual graph formalism, in which the role of edges and vertices is inverted relative to the original (Primal) graph. This transformation shifts the emphasis of brain network analysis from gray matter units to their underlying connections in two important ways. First, it applies standard graph theoretical operations to discover the organization of connections, as opposed to that of gray matter centers. Second, it helps in removing the single scalar weight restriction and allows each connection to be characterized by a vector of several features. In this paper, we introduce the main concepts of this novel dual formalism and illustrate its potential in a population study on schizophrenia.
Measuring Rank Robustness of General Complex System Matrices with Respect to Real Matrix Perturbations

This paper examines the problem of computing the real matrix perturbation having smallest norm which causes a general complex (system) matrix to drop rank. Given the state model describing a linear time-invariant system, the norm of this matrix perturbation helps to determine the robustness of several system properties with respect to real parameter variations. The norm of this perturbation, or the real-restricted singular value of the complex matrix, is known to be a discontinuous function of the complex matrix. This paper presents some theoretical results characterizing the nature of this discontinuity and presents an experimental algorithm which may be used to compute the smallest real rank-reducing matrix perturbation and its norm. Some numerical examples are included.
Chemotaxis in Neutrophil-Like HL-60 Cells

Asymmetric localization of intracellular proteins and signals directs movement during axon guidance, endothelial cell invasion, and immune cell migration. In these processes, cell movement is guided by external chemical cues in a process known as chemotaxis. In particular, leukocyte migration in the innate immune system has been studied in the human neutrophil-like cell line (HL-60). Here, we describe the maintenance and transfection of HL-60 cells and explain how to analyze their behavior with two standard chemotactic assays. Finally, we demonstrate how to fix and stain the actin cytoskeleton of polarized cells for fluorescent microscopy imaging.
Bilateral double-rooted maxillary primary canines. An abbreviated case report.

Abstract Double-rooted canines are extremely rare. A case of bilateral double-rooted maxillary primary canines in a 5-year-old black boy is reported.
OR15 De novo development of DSA following human lung transplantation is associated with changes on circulating micro-RNA involved in T and B cell regulation and fibrogenesis

Aim Chronic rejection (bronchiolitis obliterans syndrome (BOS)) is the major limitation for long-term survival after lung transplantation (LTx). Its pathogenesis, however, is poorly understood and no effective predictive biomarkers have been identified. Several studies have shown that de novo development of antibodies to donor mismatched HLA (DSA) is a significant risk factor for the development of BOS. Methods Thirty LTx recipients from Barnes Jewish Hospital/Washington University School of Medicine (10 stable DSA− and BOS−, 10 DSA+ BOS− and 10 DSA+ and BOS+) were analyzed for circulating microRNAs (miRNAs). MiRNAs expression in the recipients’ serum was detected using RNA extraction and quantitative PCR analysis. Results We identified eight miRNAs which were selectively expressed on lung allograft recipients with de novo developed DSA and diagnosed with BOS in comparison to stable LTx without DSA and BOS: miR-369-5p, miR-144, miR-134, miR-10a, miR-195 miR-142-5p, miR-133b, and miR-155 (p Conclusion Our results, for the first time, demonstrated differential expression of circulating miRNAs in lung allograft recipients with de novo development of DSA and BOS. These dysregulated miRNAs are involved in T and B cell regulation and fibrogenesis, indicating their role in the development of DSA leading to chronic lung allograft rejection.
Trends in the use and cost of chiropractic spinal manipulation under Medicare Part B

Abstract Background context Concern about improper payments to chiropractic physicians prompted the US Department of Health and Human Services to describe chiropractic services as a "significant vulnerability" for Medicare, but little is known about trends in the use and cost of chiropractic spinal manipulation provided under Medicare. Purpose To quantify the volume and cost of chiropractic spinal manipulation services for older adults under Medicare Part B and identify longitudinal trends. Study design/setting Serial cross-sectional design for retrospective analysis of administrative data. Patient sample Annualized nationally representative samples of 5.0 to 5.4 million beneficiaries. Outcome measures Chiropractic users, allowed services, allowed charges, and payments. Methods Descriptive statistics were generated by analysis of Medicare administrative data on chiropractic spinal manipulation provided in the United States from 2002 to 2008. A 20% nationally representative sample of allowed Medicare Part B fee-for-service claims was merged, based on beneficiary identifier, with patient demographic data. The data sample was restricted to adults aged 65 to 99 years, and duplicate claims were excluded. Annualized estimates of outcome measures were extrapolated, per beneficiary and per user rates were estimated, and volumes were stratified by current procedural terminology code. Results The number of Medicare beneficiaries who used chiropractic spinal manipulation grew 13% from 2002 to 2004, remained flat through 2007, and then declined 5% through 2008. An estimated 1.7 million beneficiaries (6.9%) used 18.6 million allowed chiropractic services in 2008. In inflation-adjusted dollars, allowed charges per user increased 4% through 2005 and then declined by 17% through 2008; payments per user increased by 5% from 2002 to 2005 and then declined by 18% through 2008. Expenditures for chiropractic in 2008 totaled an estimated $420 million. Longitudinal trends in allowed claims for spinal manipulation varied by procedure: the relative frequency of treatment of one to two spinal regions declined from 43% to 29% of services, treatment of three to four regions increased from 48% to 62% of services, and treatment of five regions remained flat at 9% of services. Conclusions Chiropractic claims account for less than 1/10th of 1% of overall Medicare expenditures. Allowed services, allowed charges, and fee-for-service payments for chiropractic spinal manipulation under Medicare Part B generally increased from 2002, peaked in 2005 and 2006, and then declined through 2008. Per user spending for chiropractic spinal manipulation also declined by 18% from 2006 to 2008, in contrast to 10% growth in total spending per beneficiary and 16% growth in overall Medicare spending.
Hollow fiber gas permeator with countercurrent or cocurrent flow: series solutions

The problems in the numerical solution of boundary value problems encountered in hollow fiber binary gas permeatbrs having cocurrent or countercurrent permeate flow with axial pressure drop inside the fiber bore are discussed. A series solution technique is developed to express each product composition and the pressure ratio as a power series in terms of a dimensionless membrane area for shell side constant-pressure feed flow. Cocurrent or countercurrent rating or design problems require the solution of elther one algebraic equation, two coupled algebraic equations, or three coupled algebraic equations to determine the unknown quantities of interest. Calculated product and reject compositions, stage cuts, and closed-end pressure ratios compare quite well with those from numerical solutions for practically useful low to moderate cuts over a wide range of parameters. Cocurrent rating calculations requiring solution of only one algebraic equation are recommended for shortcut procedures since flow pattern effects are significant but not large.
Pre-EuroAmerican settlement forests in Redwood National Park, California, USA: a reconstruction using line summaries in historic land surveys.

Extensive logging in the twentieth century destroyed much of the coniferous forests in the lower Redwood Creek basin of Redwood National Park. Restoration of cutover lands requires the identification of historical, pre-logging reference conditions. Field notes from the original Public Land Surveys were used to reconstruct the pre-EuroAmerican settlement forests. Most reconstructive studies based on historic surveys rely on bearing tree evidence over large areas to determine vegetation patterns over several hundreds to thousands of square kilometers. Due to the small size of the study area (approximately 200 km2), bearing tree evidence could not accurately reconstruct the vegetation at this scale. Instead, lists of the overstory and understory vegetation for each surveyed mile (line summaries) were employed. Analysis of line summaries evidence identified the historical importance, geographical range, and environmental influences on woody species and vegetation communities. Topography, especially elevation, and soil texture were significantly correlated with plot-scale ordination scores derived from non-metric multidimensional scaling. The influence of topography and distance to ocean coast on the historical distribution of dominant woody species concurs with findings from present-day field studies of local and regional old-growth forest. A comparison with present-day vegetation maps revealed that coast redwood (Sequoia sempervirens), Douglas fir (Pseudotsuga menziesii), Sitka spruce (Picea sitchensis), and red alder (Alnus rubra) experienced the most substantive changes in the vegetation as a result of twentieth century land use activities.
A molecular view of powerful and powerless speech styles: Attributional consequences of specific language features and communicator intentions

Two studies are reported. The first study examined the extent to which seven forms of language were perceived as powerful and effective when used by an interviewee in a hypothetical job interview. Results suggested a five‐level model of linguistic power and effectiveness, which is independent of communicator sex. The second study examined the same seven linguistic features but in this case two dissimilar intentions were attributed to the interviewee: desire to appear sociable versus desire to appear authoritative. Results indicated that power of style interacted with communicator intention, qualifying to an extent the five‐level model suggested by Study 7. Again, effects were independent of communicator sex. Results of both studies showed that respondents made rather fine discriminations among powerful and powerless language forms, that these discriminations were quite stable, and that some ostensibly powerless forms were judged to be relatively powerful in fact.
Opening-Mode Cracking in Asphalt Pavements: Crack Initiation and Saturation

ABSTRACT Opening-mode cracking has been commonly found in asphalt pavements and other layered materials with nearly uniform crack spacing. Due to the deformation mismatches between surface overlay and base layer of pavements, longitudinal tensile stress is induced in the surface course. When it reaches a certain level, transverse cracks will initiate at the surface to release the energy stored in the asphalt materials. When crack spacing reduces to a certain value, crack density is saturated and no new crack forms. This paper investigates the crack initiation and saturation for opening-mode cracking. Using elastic governing equations and a weak form stress boundary condition, we derive an explicit solution of elastic fields in the surface course and obtain the energy release rate, so that opening-mode cracking initiation can be determined by fracture energy criterion. Interestingly, the longitudinal stress between such cracks along the surface undergoes a transition from tensile to compressive with increa...
Finite element analysis of stability of two-dimensional viscoelastic flows to three-dimensional perturbations

Abstract We present numerical methods for analysis of the stability of two-dimensional steady viscoelastic flows to small-amplitude, two-dimensional and three-dimensional disturbances based on finite element calculations of the steady base flow and the perturbation. Direct time integration of the linearized equations of motion and iterative calculation of the most dangerous components of the eigenspectrum are tested. Finite element discretizations based on the DEVSS-G finite element discretization with Newton’s method used to compute steady-state solutions. Two different time integration schemes are tested for computing the time evolution of general, random disturbances: a θ -method operator-splitting scheme and a fourth-order Runge–Kutta method. For both time integrators, time stepping is decoupled into a solution of a modified Stokes problem and an evaluation of the time-dependent constitutive equation. The overall efficiency of both methods is extremely high, as is the potential for implementation on parallel computers. An algorithm also is presented for calculating eigenvalues with the largest real part that combines time integration of the linearized equations with a Krylov subspace method to accelerate the calculation of the eigenvalues. Although this method does not dramatically reduce the computational cost over use of time integration alone, it does provide a more complete analysis of the eigenspectrum. For both direct time integration and the hybrid time integration/Krylov calculation, the stability results for cylindrical Couette flow show quantitative agreement with the eigenvalues calculated by using other methods of analysis [M. Avgousti, A.N. Beris, J. Non-Newtonian Fluid Mech. 50 (1993) 225–251]. Contrary to the results in our previous paper [R. Sureshkumar, M.D. Smith, R.C. Armstrong, R.A. Brown, J. Non-Newtonian Fluid Mech. 82 (1999) 57–104], we find that the flow of an Oldroyd-B fluid through a closely-spaced cylinder array is stable to two-dimensional perturbations. However, allowing the perturbations to be three-dimensional and considering an isolated cylinder does not alter the conclusions of our earlier study [R. Sureshkumar, M.D. Smith, R.C. Armstrong, R.A. Brown, J. Non-Newtonian Fluid Mech. 82 (1999) 57–104] of the two-dimensional stability of widely-spaced arrays of cylinders; the flow around an isolated cylinder is computed to be stable for all values of the Weissenberg number obtainable with these calculations, We≤0.75.
Investigations into sulfobetaine-stabilized Cu nanoparticle formation: toward development of a microfluidic synthesis.

The mechanistic aspects of the formation of sulfobetaine-stabilized copper nanoparticles were investigated by using in situ XANES (X-ray absorption near edge structure), UV−vis spectroscopy, and reaction calorimetry. The tetracoordinated sulfobetaine−Cu(II) complex was reduced to a stable sulfobetaine−Cu(I) complex prior to the formation of sulfobetaine-stabilized copper nanoparticles. The stability of the Cu(I) complex was found to be sensitive to the concentration of the sulfobetaine stabilizer and the addition rate of the reducing agent. It appears to exist primarily as a linear complex. A tetracoordinated Cu(I) complex as an intermediate has also been postulated. Based on the understanding from these investigations, a microfluidic process for copper nanoparticle synthesis was designed by using sulfobetaine−Cu(I) complex as the starting material. When compared with the copper nanoparticles synthesized by a conventional batch process, the microfluidic reactor process provided particles with a smaller si...
Stress and Multiple Potential Affiliates: Does Misery Choose Miserable Company?

According to Schachter's (1959) emotional similarity hypothesis, individuals facing a threat will prefer to affiliate with others facing a more, rather than less, similar threat. Previous research has been limited largelyto hypothetical or one-time affiliation choices within dyads in response tolaboratory stressors. This study examined affiliations between preoperativesurgical patients and their multiple hospital roommates. A multiple affiliation order (MAO) procedure was developed to assess participants' affiliation levels as a function of their similarity to their multiple roommates. Patients affiliated more with roommates who were likewise preoperative andthose with more similar health problems. Participants' anxiety levelsdid not moderate either of these effects. Other potential MAO applications are presented, and their implications for future research are discussed.
Challenges in understanding disparities in drug use and its consequences.

Racial/ethnic disparities in health have long been documented in a broad range of medical conditions in the United States. For example, Blacks have higher HIV incidence and AIDS-related mortality than do Whites., This article summarizes racial/ethnic differences in drug use and its consequences in the United States and proposes three key challenges to the study of disparities in drug use and its consequences. These are (a) patterns of drug use and misuse are complex, with different patterns of use of different drugs in different racia,/ethnic groups; (b) racial/ethnic differnces in use of drugs are not always associated with comparable differences in the consequences of drug use; and (c) the consequences of drug use are associated with drug use itself and other social/economic circumstances. Each of these challenges is discussed, and suggestions offered for future research that may help overcome them.
S-Parameter Based Macro Model of Distributed-Lumped Networks Using Exponentially Decayed Polynomial Function

A Scattering-Parameters (S-Parameters) based macromodel of distributed-lumped networks is presented. The networks can include capacitive cutsets, inductive loops, RLC meshes, and lossy transmission lines. An efficient network reduction algorithm is developed to reduce the original network into a network containing one multiport component together with the sources and loads of interest. The S-Parameters of the circuit components are approximated by Taylor series to simplify the reduction process. Exponentially Decayed Polynomial Function (EDPF) approximation is used to derive the macromodel, the higher accuracy can be obtained by selecting time constant according to an error criterion. The macromodel is always stable for a stable system and very flexible that the accuracy of the model can be controlled by adjusting the order of approximation. The experimental results indicate that our model can approach the accuracy of SPICE with one or two order less computing time.
The Synthesis of Carbon-13 Enriched Monosaccharides Derived from Glucose and Mannose

Abstract A modified Kiliani-Fischer reaction is used to prepare multigram quantities of [1-13C]-enriched glucose and mannose which are converted chemically or enzymatically into other labeled monosaccharides. The simplest conversion is the synthesis of labeled fructose from labeled glucose using commercially available immobilized glucose isomerase. The equilibrium for this reaction provides a 1:l mixture of glucose and fructose which can be separated by chromatography. The equilibrium can be shifted toward fructose by treating the reaction with germanate ion. [1-13C]Mannose can be converted into more useful sugars using a modification of the Lobry de Bruyn-Alberda van Ekenstein transformation. In this reaction, D-[1-13C]mannose is treated with an aqueous solution of dilute alkali and phenylboronate to form a mixture of labeled fructose, mannose and glucose. Fructose can be converted to a mixture of methyl fructofuranosides by using trifluoroacetic acid in methanol. [2-13C]Dihydroxyacetone can be prepared ...
Simulation of vapor emissions from liquid spills

Abstract An improved model for simulating vapor emissions from a multicomponent liquid spill (LSM90) has been developed incorporating three mechanisms for transfer to the gas phase: (i) flashing liquid, (ii) entrainment as aerosol, and (iii) liquid pool evaporation. The simulation accounts for both heat and mass transfer effects. Flexibility is given in describing the spill site configuration and chemical release composition. Several im- provements provide a more representative simulation. Pools spread more naturally within a diked area. The pool is also checked repeatedly to determine whether vaporization is by evaporation or a boiling mechanism. Aerosol formation rates are calculated using the new AIChE CCPS RELEASE model. The DIPPR database has been incorporated to give access to the physical properties of numerous materials. The model underwent a full prog- ram of validation. A test plan using over 90 cases was designed to check: (1) trends in the model's behavior from variations in input data, and (2) the accuracy of results when compared to experimental data. Single component land spill evaporation rates were compared against experimental results reported by Kawamura, MacKay and Matsugu. The model was also tested against two sets of liquified natural gas (LNG) spills on water: Matagorda Bay and the Burro Series.
THE NEAR FIELD TO FAR FIELD TRANSFORMATION

If a scattering problem is solved by finite element, finite volume or finite difference methods, it is necessary to predict the far field pattern (or radar cross‐section) by using a near field to far field transformation. Usually this is done using the Stratton‐Chu integral relations, which give the far field pattern in terms of a near field surface integral. When volume‐based methods are used this is unnatural, and it may be necessary to employ interpolation procedures to provide the necessary surface data. In this paper an alternative method based on volume integrals is proposed. The main advantage of the new procedure is that it allows the use of discrete quantities that are naturally available from the numerical scheme. However, it is now necessary to perform volume integrals. The error in the new procedure is examined, and a simple numerical example provided.
Supporting military communications with Named Data Networking: An emulation analysis

Named Data Networking is a new concept that takes a fundamentally different approach to what is found in Internet Protocol (IP) network systems. IP-type networks name locations (in the form of IP addresses) to route messages to destinations when sending data. Named Data Networks (NDNs), on the other hand, are primarily concerned about the data itself and not necessarily about the locations where the data is found. The forwarding decisions in an NDN are based on the actual data being sent/requested and not the presumed locations of the data content. Instead of naming network locations to facilitate message delivery (IP), NDNs name the actual data. This new approach allows the nodes of NDNs to more easily take advantage of the broadcast capabilities found in many of today's networking devices while also avoiding many of the problems and inefficiencies that exist within IP networks. Because many modern military communication systems rely on IP mechanisms to provide networking functionality, it is worthwhile to investigate the benefits NDN might be able to provide these systems. Specific design features of the NDN architecture provide an efficient alternative to IP-based systems, particularly those systems operating within challenged environments. Thus, this paper presents an emulation analysis of NDN-aided military communication networks. We also briefly describe the NDN architecture and how it can be incorporated into various military communication networks, such as the Navy's Automated Digital Networking System (ADNS) and the Army's Warfighter Information Network-Tactical (WIN-T). Preliminary results show tremendous performance gains when the NDN architecture is applied to these military communication networks.
The DIRTY Model. II. Self-consistent Treatment of Dust Heating and Emission in a Three-dimensional Radiative Transfer Code

In this paper and a companion paper we present the DIRTY model, a Monte Carlo radiative transfer code, self-consistently including dust heating and emission and accounting for the effects of the transient heating of small grains. The code is completely general: the density structure of the dust, the number and type of heating sources, and their geometric configurations can be specified arbitrarily within the model space. Source photons are tracked through the scattering and absorbing medium using Monte Carlo techniques, and the effects of multiple scattering are included. The dust-scattering, -absorbing, and -emitting properties are calculated from realistic dust models derived by fitting observed extinction curves in Local Group galaxies, including the Magellanic Clouds and the Milky Way. The dust temperature and the emitted dust spectrum are calculated self-consistently from the absorbed energy, including the effects of temperature fluctuations in small grains. Dust self-absorption is also accounted for, allowing the treatment of high optical depths, by treating photons emitted by the dust as an additional heating source and adopting an iterative radiative transfer scheme. As an illustrative case, we apply the DIRTY radiative transfer code to starburst galaxies wherein the heating sources are derived from stellar evolutionary synthesis models. Within the context of the starburst model, we examine the dependence of the ultraviolet to far-infrared spectral energy distribution, dust temperatures, and dust masses predicted by DIRTY on variations of the input parameters.
The Hall effect in oriented α-Pu

Abstract The ordinary Hall effect has been measured for random α-Pu and two configurations of oriented α-Pu. The results have been interpreted in terms of a hexagonal model with two components determining the Hall coefficient. The behavior of these components is qualitatively explicable by considering a Jones zone construction. Some evidence for antiferromagnetic ordering is seen at low temperatures.
How Do Natural Killer Cells Find Self to Achieve Tolerance

Natural killer (NK) cells provide innate defense against tumors and infections by virtue of potent capacities to immediately kill cellular targets and produce cytokines. These effector functions may potentially damage normal self-tissues unless they are kept in check by tolerance mechanisms that need clarification. Here, we discuss recent studies indicating that the NK cells acquire functional competence directly through engagement of their MHC-specific receptors by self-MHC. Ironically, these receptors were first identified in terms of recognizing target cell MHC class I molecules and inhibiting NK cells in effector responses. Other studies of NK cell tolerance are also discussed. Although these studies begin to clarify the means by which NK cell tolerance is achieved, much more investigation is needed because NK cell tolerance is relevant to clinical observations in patients with infections and cancer.
Imine-Bridged Planar Poly(p-phenylene) Derivatives for Maximization of Extended .pi.-Conjugation. The Common Intermediate Approach

Abstract : Described are two approaches to planar conjugated poly(p-phenylene) (PPP) derivatives. The first approach, involving lactam bridges, was unsuccessful due to the insolubility of the 6(511)-phenanthridinonyl moieties. The second approach, which utilized imine bridges, worked excellently since the compounds were generally soluble and the bridge formations were highly efficient. The main PPP backbone was synthesized via Pd(O)-catalyzed coupling of an arylbis(boronic ester) with an aryldibromide. Imine bridges, that are formed by exposure of the polymer to trifluoroacetic acid or HCl, force the consecutive units into planarity. The bridging units are sp2 hybridized thus allowing for greater it-electron flow between the consecutive phenyl units. The polymers, upon planarization, exhibit enormous bathochromic shifts of 210-240 nm.
OMVPE growth of GaxIn1−xP/GaAs(AlyGa1−yAs) heterostructures for optical and electronic device applications

Abstract Low pressure organometallic vapor phase epitaxy is used for the growth of Ga x In 1− x P lattice matched to GaAs and Al y Ga 1− y As buffer layers grown on GaAs substrates. Photoluminescence is used to determine lattice matched compositions. The group III gas phase composition required for lattice matching to Al 0.97 Ga 0.03 As is different than that for GaAs by 2–3%. Quantum well heterostructures of Al 0.97 Ga 0.03 As/Ga 0.5 In 0.5 P/Al 0.97 Ga 0.03 As as narrow as 30 A exhibit photoluminescence. These materials are used to realize a GaAs/Al y Ga 1− y As graded index-separate confinement light emitting diode with a Ga 0.5 In 0.5 P active region. In addition, the GaAs/Ga 0.51 In 0.49 P interface shows electron accumulation suggesting a two-dimensional electron gas has formed at the interface. The growth, fabrication, and characterization of these device materials are discussed.
Pericardiocentesis guided by a pulse generator.

Abstract This study was performed to compare pericardiocentesis guided by a pacing current applied through the pericardiocentesis needle with the traditional method of monitoring ST segment elevation from the needle tip electrogram. ST segment elevation was measured at 3 mm from the epicardium, after epicardial contact, after epicardial penetration and again at 3 mm from the epicardium after epicardial penetration. Two millivolts of ST segment elevation gave the highest combined positive (86%) and negative (79%) predictive value for epicardial contact by the pericardiocentesis needle between the two groups with the largest difference: 3 mm from the epicardium before contact and after epicardial penetration. Therefore, ST segment monitoring cannot reliably determine the point of epicardial contact. To determine the optimal stimulus strength for pulse generator-guided pericardiocentesis, pacing studies were performed using 2, 4, 6, 8 and 10 mA unipolar stimulus strengths. The pacing studies were performed both with and without a hemodynamically significant pericardial effusion to determine if increased pericardial pressure altered the pacing threshold. A 4 mA unipolar cathodal stimulus was chosen because it captured the ventricle only with direct contact of the epicardium. Ten dogs were instrumented and cardiac tamponade produced so that a subxiphoid approach to the epicardium with the pacing needle electrode could be attempted. During pericardiocentesis, needle tip electrograms were recorded, alternating with pacing attempts using a 4 mA unipolar stimulus. In all 10 dogs, the effusion was entered and epicardium was contacted as indicated by capture. No myocardial perforation or coronary artery or venous injuries were produced. These findings support the use of a pulse generator to guide pericardiocentesis.
Pyrosequencing reveals correlations between extremely acidophilic bacterial communities with hydrogen sulphide concentrations, pH and inert polymer coatings at concrete sewer crown surfaces

Aims To investigate the acidophilic bacterial communities involved in microbially induced concrete corrosion (MICC). Methods and Results Our study sites located downstream from a forced main provided a unique opportunity to study the microbial communities involved in MICC under different environmental conditions (gradients of atmospheric H2S, sulphate concentration and pH) and under pipe modifications (coated vs uncoated). Bacterial cell density estimated by both cultivation- and DNA-based methods was low in the corroded sewer samples. Pyrosequencing and cloning showed that Mycobacterium and Acidithiobacillus dominated the acidophilic microbial communities. Methylacidiphilum was also dominant in samples where methane was detected. Correlation analysis indicated that Mycobacterium and Acidithiobacillus were significantly affected by pH and that Mycobacterium could better withstand highly acidic conditions compared to Acidithiobacillus. Conclusions Communities dominated by Mycobacterium favoured conditions in the lined sewer pipes, while communities with a higher relative abundance of Acidithiobacillus favoured the unlined sewer pipes. Significance and Impact of the Study Identifying the key micro-organisms involved in MICC and knowing how they interact with their environment are essential aspects for identifying steps towards concrete corrosion management.
131-I treatment of micronodular pulmonary metastases from papillary thyroid carcinoma

BACKGROUND Pulmonary metastases from papillary thyroid carcinoma shorten the survival of the hosts. Treatments with 131-I have been reported to induce disappearance of these tumors in a large proportion of afflicted patients. In this study, consecutive patients with diffuse micronodular lung metastases from papillary thyroid carcinoma were examined to determine if disappearance of tumor occurred, and how much disappeared, after substantial amounts of 131-I were administered. METHODS Of 232 patients treated with 131-I for thyroid carcinoma between 1985 and 1994, 12 patients between the ages of 5 and 45 years exhibited evidence of micronodular metastases to the lungs that concentrated 131-I. Each patient had undergone total or nearly total thyroidectomy and cervical lymph node dissection. All neoplasms were well differentiated papillary carcinoma, but one also had focal, poorly differentiated insular components. Follicle formation by tumors varied from less than 10% to 100% of the histologic sections. Effects of treatment were measured by three indices: chest X-ray and/or CT images, scintigraphic images, and serum thyroglobulin levels. Individual activities of 131-I ranged from 2.2 gigabequerel (GBq) (initial activity in the 5-year-old patient) to 13 GBq, and were greater than 7.4 GBq in 6 patients. Only one treatment was given to three patients, two were given to seven, and more than two were given to two. The duration of follow-up was at least one year. RESULTS In two patients, the only evidence of lung metastases was on scintigraphic images made a few days after treatment. Another patient had a normal X-ray but showed diffuse uptake of 131-I in the lungs on a diagnostic scintiscan. Of the nine patients with abnormal X-ray and CT images, seven showed improvement, but tumors disappeared in only two. In the ten patients with abnormalities on the diagnostic scintiscans, five eventually manifested no abnormality. At the outset, thyroglobulin levels exceeded 10 ng/mL in each patient; 3 individuals exhibited a decline in level by 25% or more, and a value of less than 6 ng/mL, uncomplicated by thyroglobulin antibodies, was seen in two patients. Only two patients attained normality in all three indices. Hematologic toxicity was modest and reversible. CONCLUSIONS Despite a number of previous reports that pulmonary metastases from thyroid carcinoma disappear in approximately half of patients treated with 131-I, evidence of tumor reduction was found in most, but a complete remission occurred in only 2 of 12 patients. Nevertheless, 131-I therapy may be useful to decrease the tumor burden in many such patients. Cancer 1996;78:2184-92.
Optimal Interplanetary Trajectories for Chemically Propelled Spacecraft

Primer vector theory is applied to trajectory optimization for high-thrust, interplanetary missions. Using a sphere-of-influence analysis, it is shown that the interplanetary problem can be solved in the same format with which the central-body problem has been treated, merely by modifying the initial and final primer vectors. For the minimum-impulse case, this reduces to applying a scalar factor to the primer, but to obtain maximum final spacecraft mass, the primer must also undergo a rotation. The rotation accounts for the fact that launch vehicle performance is a function of both hyperbolic excess velocity and launch asymptote declination. This theory is used to generate optimal interplanetary trajectories for the 1973 Mars opportunity and a comparison between the optimal results and single-plane, ballistic transfers is presented.
Why nice guys finish last: A comment on Robert Axelrod's The Evolution of Cooperation

Robert Axelrod's The Evolution of Cooperation (1984) offers a cogent explanation for why mutually-beneficial behavior may emerge in a prisoner's dilemma game. Provided that the game will be repeated an indefinite number of times, that players of the game are capable of recognizing any other player and of remembering the nature of the interaction between the two of them in prior encounters, and that there is not too much discounting of the payoffs to be gained from future interactions, a strategy of reciprocity can be most desirable for players of the game. Even though such a mutual give-and-take strategy runs counter to the dictates of self-interest from a simple, short-run point of view, it can best promote one's interests over the long run when one's fellow players are capable of retaliating sufficiently tomorrow for any transgressions made against them today. As evidence for his argument, Axelrod reports on the results of several computer simulations that he has conducted. Some of the simulations consist of round-robin tournaments between the strategies submitted by various social and natural scientists for playing a repeated prisoner's dilemma game. Invariably, the winner of these tournaments is the simplest decision rule submitted, TIT FOR TAT: an eye-for-eye strategy that starts off by making a cooperative move and then mimics whatever the opposing player has done on the preceding move. TIT FOR TAT wins the tournament even when it is well-known beforehand that such a decision rule will be competing in the tournament. TIT FOR TAT also wins the overall round-robin even though it does no better in any head-to-head competition than the opposing decision rule with which it is paired.
Histogram Transformation for Inter-Modality Image Registration

This paper describes an efficient image transformation method based on histogram information and some prior knowledge of tissue expression in different modalities for registration of images from different image aquisition methods, such as CT and MRI. The metric defined in this paper represents a computationally efficient alternative to traditional, mutual information based methods. The optimization step in the registration algorithm can be carried out either by using a normalized cross-correlation function or as a simple image subtraction, which makes it suitable for hardware implementations.
REPRESENTATIONS OF PARAFERMI RINGS

Abstract We consider the operator algebra corresponding to a system consisting of an arbitrary finite number v of parafermi oscillators with a view to obtaining all irrepresentations of the operator algebra defining it. It is shown that this algebra is isomorphic to the Lie algebra of the orthogonal group B v in 2 v + 1 dimensions. The known results of the representation theory of the orthogonal group are then used to find the representations of the ring of parafermi operators. In particular it is seen that the so-called Green ansatz for a parafermi ring arises in a natural way and that, in a certain sense, it furnishes the most general “solution” of the parafermi algebra. The case of a parafermi ring of order 2, which is the simplest non-trivial case, is considered in some detail.
What the Rorschach can do for you: incremental validity in clinical applications.

Psychological assessment instruments vary in how much structure they provide and the extent to which their meaning and purpose are apparent. The Rorschach Inkblot Method (RIM) is a relatively unstr...
Design and synthesis of unnatural heparosan and chondroitin building blocks

Triazole linked heparosan and chondroitin disaccharide and tetrasaccharide building blocks were synthesized in a stereoselective manner by applying a very efficient copper catalyzed azide-alkyne cycloaddition (CuAAC) reaction of appropriately substituted azido-glucuronic acid and propargyluted N-acetyl glucosamine and N-acetyl galactosamine derivative, respectively. The resulting suitably substituted tetrasaccharide analogues can be easily converted into azide and alkyne unit for further synthesis of higher oligosaccharide analogues.
Age and strain comparisons of neurotransmitter synthetic enzyme activities in the mouse.

: Activities of the neurotransmitter synthetic enzymes, choline acetyltransferase (EC 2.3.1.6; ChAT), glutamic acid decarboxylase (EC 4.1.1.15; GAD), and tyrosine hydroxylase (EC 1.14.3.2; TH), were assayed in four brain regions of A/J and C57BL/6J mice at three ages (4. 18, and 24 months). The brain regions assayed were the fronto-parietal cortex, hippocampus, striatum, and cerebellum. Strain effects: In some brain regions, at several ages, ChAT activity did not differ among the two srains. However, ChAT was higher in the C57BL/6J strain in the cortex at 18 months, the hippocampus at 18 and 24 months, the striatum at 24 months, and the cerebellum at 4 months. The reverse was true in the cerebellum at 24 months, where ChAT was higher in A/J mice. GAD activity in C57BL/6J mice compared to that of A/J mice was higher in the striatum and cortex, and lower in the hippocampus and cerebellum. TH activities in all four regions were generally higher in C57BL/6J mice than in A. J mice. Age effects: Age differences in enzyme activities varied with the genetic strain. ChAT activity generally was higher in brain regions of older mice of both strains. GAD activity was lower in some brain regions of older mice compared to those of younger mice (A/J striatum, C57BL/6J cortex), but higher in other brain regions of older mice compared to those in younger mice (C57BL/6J striatum, hippocampus of both strains). Whereas there were no age-related differences in striatal TH in either strain, TH activity was higher in other brain regions of older mice (A/J cortex, cerebellum and hippocampus; C57BL/6J cerebellum). In C57BL/6J mice, cortical TH was higher at 18 months than at 4 months, but lower at 24 months than at 18 months. Higher activities of hippocampal ChAT and GAD and cerebellar TH in older C57BL/6J mice reflected increases in Vmax, with no age differences in Km values for substrates. These findings indicate that neurochemical profiles as well as the effects of age on these profiles vary with genetic strain.
Estimating groundwater evapotranspiration rates using diurnal water-table fluctuations in a semi-arid riparian zone

In semi-arid climates, phreatophytes draw on shallow aquifers, and groundwater evapotranspiration (ETG) is a principal component of groundwater budgets. Diurnal water table fluctuations, which often are a product of ETG, were monitored in the riparian zone of Red Canyon Creek, Wyoming, USA. These fluctuations were higher in a riparian wetland (2–36 mm) than a grass-covered meadow (1–6 mm). The onset and cessation of water-table fluctuations correspond to daily temperatures relative to freezing. Spatial differences were due to vegetation type and specific yield, while temporal changes were due to vegetation dormancy. Ratios of ETG to potential evapotranspiration (PET), K c,GW, were similar to ratios of actual evapotranspiration (ET) to PET, K c, in semi-arid rangelands. Before vegetation senescence, K c,GW increased between precipitation events, suggesting phreatophytes pull more water from the saturated zone as soil moisture decreases. In contrast, K c decreases with soil moisture following precipitation events as ET becomes increasingly water-limited. Error in ETG is primarily from estimates of specific yield (S y), which is difficult to quantify in heterogeneous sediments. ETG values may be more reliable because the range of acceptable S y is smaller than K c and S y does not change with vegetation type or soil moisture.