cssi/SciSciGPT-SciSciNet huggingface dataset:
A model for the origin of protein synthesis as coreplicational scanning of nascent RNA.

The origin of protein synthesis is one of the major riddles of molecular biology. It was proposed a decade ago that the ribosomal RNA evolved from an earlier RNA-replisome (a ribozyme fulfilling RNA replication) while transfer RNA (tRNA) evolved from a genomic replication origin. Applying these hypotheses, I suggest that protein synthesis arose for the purpose of segregating copy and template RNA during replication through the conventional formation of a complementary strand. Nascent RNA was scanned in 5′ to 3′ direction following the progress of replication. The base pairing of several tRNA-like molecules with nascent RNA released the replication intermediates trapped in duplex. Synthesis of random peptides evolved to fuel the turnover of tRNAs. Then the combination of replication-coupled peptide formation and the independent development of amino acid-specific tRNA aminoacylation resulted in template-based protein synthesis. Therefore, the positioning of tRNAs adjacent to each other developed for the purpose of replication rather than peptide synthesis. This hypothesis does not include either selection for useful peptides or specific recognition of amino acids at the initial evolution of translation. It does, however, explain a number of features of modern translation apparatus, such as the relative flexibility of genetic code, the number of proteins shared by the transcription and translation machines, the universal participation of an RNA subunit in co-translational protein secretion, ‘unscheduled translation’, and factor-independent translocation. Assistance of original ribosomes in keeping apart the nascent transcript from its template is still widely explored by modern bacteria and perhaps by other domains of life.
Role of protein kinases on acid-induced duodenal bicarbonate secretion in rats.

Luminal acid is the most potent physiologic stimulus for duodenal bicarbonate secretion (DBS) ([1). Indomethacin inhibits acid-induced DBS, consistent with the involvement of cyclooxygenase (COX) ([2). Also, protein kinase A (PKA) is thought to be involved, since cAMP stimulates the cystic fibrosis transmembrane conductance regulator (CFTR), a candidate apical HC03 - channel and the basolateral sodium bicarbonate cotransporter (NBC) ([3, [4). DBS also cAMP dependent. Nevertheless, little is known about the involvement of other kinases, such as protein kinase C (PKC) and tyrosine kinase (TK), in acid-induced DBS. We thus tested the hypothesis that acid-induced DBS requires intracellular signaling pathways by testing the effects of protein kinase inhibitors, staurosporine for PKC, H-89 for PKA and genistein for TK on acid-induced DBS in rats.
Real world problems bringing life to course content

The computer technology program at Purdue University prepares students for existing and emerging jobs and careers in the application of information systems and technology. Many courses are designed with a theoretical framework supplemented with hands-on learning experiences and reinforced by addressing real-world problems through class projects. These class projects are designed with a problem-based/problem-centered framework.Anxious to engage in hands-on activity, students have a tendency to dive right into programming or systems design assignments. The use of structured methods that require careful planning like the process to define requirements, evaluate design options, build on schedule, and the setup of testing and evaluation tools do not hold much relevance to the budding IT professional. Projects change this perspective. Students gain a meaningful understanding of why and how structured methodologies affect success in a team-based environment. The implementation and relevance of textbook methodology comes to life in real-world examples of changing requirements, budget constraints, culture, and competing objectives. Students gain experience with the less tangible 'people skills' qualities that get lost in the prescriptive text book descriptions. While our experiences with the benefits to student learning are discussed here, the traps and obstacles to taking a project approach to traditional classroom instruction can be daunting. They include the ability to manage and direct open-ended assignments, managing student and customer expectations, engaging real-world customers, defining project scope, managing to a real world deliverable, liability issues, and customer commitment.This paper reviews the lessons learned from five (5) different successful and unsuccessful experiences implementing problem-based/problem-centered learning within the undergraduate computer program at Purdue University.
Crack arrest in steels

Abstract This paper examines 3 theories that have been used to characterize the arrest capabilities of steels and structures: (1) The static analysis, arrest toughness ( K Ia ) theory; (2) The dynamically loaded/stationary crack toughness ( K Id ) theory, and (3) The dynamic analysis, propagating crack energy or toughness ( R ID or K ID ) theory. These three concepts are examined in the light of measurements of unstable fracture and crack arrest in wedge-loaded DCB test pieces together with a fully dynamic analysis of the experiments.
Occult choriocarcinoma discovered by positron emission tomography/computed tomography imaging following a successful pregnancy.

Abstract Background Positron emission tomography (PET) is commonly used to detect occult or recurrent malignancy, including tumors of the female genital tract. Recently, there have been reports of PET scans used in patients with Gestational Trophoblastic Disease (GTD). Case A 22-year-old female presented with vaginal bleeding and elevated β-hCG 7 months after a spontaneous vaginal delivery of a healthy infant. She had a history of molar pregnancy and persistent GTD requiring multi-agent chemotherapy. Metastatic evaluation with computed tomography and magnetic resonance imaging showed no evidence of GTD. A positron emission tomography/computed tomography (PET/CT) scan revealed a focus of metabolic activity in the left pelvis. The patient underwent an exploratory laparotomy that revealed metastatic choriocarcinoma in the left broad ligament. Conclusion PET/CT may be useful in the evaluation of occult choriocarcinoma when conventional imaging fails to identify metastatic disease.
Local polynomials for data detrending and interpolation in the presence of barriers

We discuss features of local polynomial interpolation (LPI), focusing on the problem with unstable solutions of the LPI system of linear equations. We develop a new diagnostic based on condition number values. Also, a variant of Tikhonov regularization is proposed, which allows the production of continuous predictions and prediction standard errors nearly everywhere in the data domain. This variant of LPI can be used in the presence of barriers defined by polylines. LPI model is a good candidate for real time automatic mapping of the data regularly collected from the environmental monitoring networks. We illustrate the LPI usage with both simulated data and real data.
Tunable UV LIF of terbium-doped bacteria endospores

Terbium-dipicolinic acid can be used to enhance the UV fluorescence detection of selected biological agents and endospore cells. We are using new tunable UV laser near 220nm-280nm to optimize the excitation wavelength and detection sensitivity, and studying the acid solution/buffer mix to optimize the fluorescence yield. Enhancements on the order of a factor of 20 have been observed so far.
Asymptotic analysis of growing plane strain tensile cracks in elastic-ideally plastic solids

An exact asymptotic analysis is presented of the stress and deformation fields near the tip of a quasistatically advancing plane strain tensile crack in an elastic-ideally plastic solid. In contrast to previous approximate analyses, no assumptions which reduce the yield condition, a priori, to the form of constant in-plane principal shear stress near the crack tip are made, and the analysis is valid for general Poisson ratio ν. Specific results are given for ν = 0.3 and 0.5, the latter duplicating solutions in previous work by L.I. Slepyan, Y.-C. Gao and the present authors. The crack tip field is shown to divide into five angular sectors of four different types ; in the order in which these sweep across a point in the vicinity of the advancing crack, they are : two plastic sectors which can be described asymptotically (i.e., as r → 0, where r is distance from the crack tip) in slip-line terminology as ‘constant stress’ and ‘centered fan’ sectors, respectively ; a plastic sector of non-constant stress which cannot be described asymptotically in terms of slip lines; an elastic unloading sector; and a trailing plastic sector of the same type as that directly preceding the elastic sector. Further, these four different sector types constitute the full set of asymptotically possible solutions at the crack tip. As is known from prior work, the plastic strain accumulated by a material point passing through such a moving ‘centered fan’ sector is O(ln r) as r → 0 ; it is proved in the present work that the plastic strain accumulated by a material point passing through the ‘constant stress’ sector ahead of a growing crack must be less singular than In r as r → 0. As suggested also in earlier studies, the rate of increase of opening gap δ at a point currently at a distance r behind, but very near, the crack tip is given for crack advance under contained yielding by δ = αJσ0+β(σ0E)a ln(Rr) where a is crack length, σ0 is tensile yield strength, E is Young's modulus, J is the value of the J-integral taken in surrounding elastic material, and the parameters α and R are undetermined by the asymptotic analysis. The exact solution for ν = 0.3 gives β = 5.462, which agrees very closely with estimates obtained from finite element solutions. An approximate analysis based on use of slip line representations in all plastic sectors is outlined in the Appendix.
Using Hydrogen Bonds to Design Acentric Organic Materials for Nonlinear Optical Users

Abstract Second order non-linear optical (NLO) effects, such as second harmonic generation, occur only in materials that are acentric. Finding ways to assure that a bulk material is acentric has been a serious hurdle in the design of new organic materials for non-linear optical uses.1 A trivial, albeit useful, solution to the symmetry problem is to use chiral molecules which necessarily crystallize in acentric structures.2 The general solution to the problem involves understanding how to promote self-assembly of molecules, regardless of their molecular symmetry, into acentric arrays. We have found a partial answer to the asymmetric self-assembly question using intermolecular hydrogen bonds.
Learning robust build-orders from previous opponents with coevolution

Learning robust, winning strategies from previous opponents in Real-Time Strategy games presents a challenging problem. In our paper, we investigate this problem by using case-injection into the teachset and population of a coevolutionary algorithm. Specifically, we take several winning build-orders we created through hand-tuning or coevolution and periodically inject them into the coevolutionary population and/or teachset. We compare the build-orders produced by three different case-injection methods to the robustness of build-orders produced without case-injection and measure their similarity to all the injected cases. Our results show that case injection works well with a coevolutionary algorithm. Case injection into the population quickly influences the strategies to play like some of the injected cases, without losing robustness. This work informs our ongoing research on finding robust build-orders for real-time strategy games.
Frequency dependence of third-harmonic generation in cis- and trans-polyacetylene: importance of the degenerate ground state to nonlinear optical response☆

Abstract Third-harmonic generation (THG) measurements on cis - and trans -polyacetylene over the pump frequency range from 0.55 through 1.25 eV show that χ (3) (3 ω ; ω , ω , ω ) for trans -(CH) x is an order of magnitude larger than that for the cis -isomer over the entire spectral range, even comparing the respective 3ω resonance maxima. The THG data demonstrate a symmetry specific mechanism favoring the degenerate ground state system, consistent with the existence of an important contribution from virtual soliton pairs enabled by nonlinear zero-point fluctuations. Because the soliton pair creation energy at finite separation is less than the energy gap, χ (3) can be simultaneously resonant at 3ω and at 2ω, and, therefore, significantly enhanced in polymers with a degenerate ground state.
Gide’s La Symphonie pastorale as a Bildungsroman

In the light of Goethe’s strong influence on Andre Gide and the latter’s interest in apprenticeship and psychoanalysis, this essay examines La Symphonie pastorale as a Bildungsroman. Noting that the Bildungsroman is a predominantly male genre, the study discusses the implications of the apprentice Gertrude’s gender from a psychoanalytic perspective. Using Freud’s theory, the effects of the pre-Oedipal phase and the Oedipus complex on her, as well as the dialectic of inward-outward development are analyzed. The developments of the Pastor’s wife, Amelie, and their son, Jacques, are also examined. Amelie’s limited development foreshadows Gertrude’s, whereas Jacques’s Bildung shows the disparity between male and female developments. While Gertrude becomes the victim of the Pastor’s failure, Jacques learns from it and becomes independent.
Evaluating Geography Textbook Questions from a Spatial Perspective: Using Concepts of Space, Tools of Representation, and Cognitive Processes to Evaluate Spatiality

Abstract This article examines whether questions embedded in geography textbooks address three components of spatial thinking: concepts of space, tools of representation, and processes of reasoning. A three-dimensional taxonomy of spatial thinking was developed and used to evaluate questions in four high school level geography textbooks. The results indicate that textbook questions focus on low-level spatial concepts more frequently than high-level spatial concepts; few questions require students to create various kinds of spatial representations; and textbook questions only rarely encourage higher-order cognitive skills. The study provides insights on the design and use of textbook questions to foster learning to think spatially.
Delivery of pseudorabies virus envelope antigens enclosed in immunostimulating complexes (ISCOMs): elicitation of neutralizing antibody and lymphoproliferative responses in swine and protection in mice

An experimental subunit vaccine that consisted of pseudorabies virus (PRV) envelope glycoproteins enclosed into immunostimulating complexes (PRVenv/ISCOM) was constructed, and evaluated in DBA/2 mice and inbred swine of the SLA hoplotype c/c. Two to three weeks after the first vaccine dose, specific anti-PRV antibodies could be demonstrated by ELISA or virus neutralization (VN) assays. Booster PRVenv/ISCOM vaccinations resulted in rapid and significant increases in antibody titres in both mice and swine. In addition, a week after receiving the third PRVenv/ISCOM vaccine dose swine peripheral blood mononuclear cells exhibited significant proliferation in response to stimulation with PRV virion antigen. Moreover, two doses of vaccine sufficed to protect mice fully against lethal virus challenge. Therefore, the data presented here support the ISCOM as a viable antigen delivery system for subunit PRV vaccines.
Progress towards achieving profile control in the recently upgraded DIII–D plasma control system

Abstract This paper describes the improvements being made in the capabilities of the DIII–D plasma control system (PCS) towards achieving optimization of current and pressure profiles in advanced tokamak discharges. Key improvements have been increased processing power and the ability to include profile diagnostic data. The recently completed upgrade of the PCS to Linux based Intel computers connected with 2 Gigabit/s Myrinet networking technology has been successful in achieving the goals of increasing the overall performance and flexibility of the system. The new Intel computing system has increased processing power by a factor 30 over the older i860 based systems. The Myrinet fiber based network has allowed the inclusion of data in real-time from DIII–D diagnostics, situated in remote locations within the DIII–D research facility. The PCS now collects 32 channels of motional stark effect (MSE) data and uses these data for real-time computation of the safety factor (q) profile. Electron temperature and density profile data from the Thomson scattering diagnostic and electron temperature profile data from the electron cyclotron emission (ECE) diagnostic are presently being added. Addition of an ion temperature and toroidal rotation profile data from the charge exchange recombination diagnostic is planned. Feedback control by the PCS of the electron temperature at two points has been demonstrated using either ECH or neutral beam power. This has been used to modify current profile evolution during plasma current ramp up. Specifics of the latest improvements to the DIII–D PCS are detailed here.
Abstract 461: Modulation of estrogen receptor (ER) and androgen receptor (AR) by a modified CRISPR-Cas9 system

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated (Cas) system is a bacterial adaptive immune defense against foreign nucleic acids from viruses, plasmids, and other mobile genetic elements. There are three types of CRISPR systems; type II uses single effector enzyme, Cas9, to cleave double-stranded DNA (dsDNA). Because of this unique feature, CRISPR/Cas9 system has been widely used as a genetic engineering tool from bacteria to mammals. In this system, Cas9 nuclease can bind and cleave genome directed by sequence-specific guide RNA (gRNA). While the wild type Cas9 can cleave double stranded DNA, the mutant Cas9 at D10A and H804A can only bind to but cannot cleave the DNA. Given this unique feature, we tried to repurpose Cas9 as a gene activation or suppression tool. To achieve this, we generated DMCas9 (double-mutant Cas9), and fused it with VP16AD (VP16 activation domain) or VP64AD (VP64 activation domain) to explore its utility for gene activation. To generate a Cas9-based gene silencing tool, we fused DMCas9 with Krab, a well-known protein domain with suppression function. Using a reporter system carrying a specific sequence that was recognized by a given gRNA and mCherry as a readout, we demonstrated that co-expression of VP16AD-DMCas9 and specific gRNAs leads to a at least three-fold induction of mCherry signal; in contrast, DMhCas9-Krab along with the specific gRNA resulted in a significant suppression of mCherry activity. Furthermore, we showed that DMCas9-Krab combined with gRNAs suppressed endogenous expression of AR and ER in MCF-7 cells, causing cell growth inhibition. Together, these results demonstrate the feasibility of Cas9-based gene activation and gene suppression. Citation Format: Nanjiang Zhou, Yin-Yuan Mo. Modulation of estrogen receptor (ER) and androgen receptor (AR) by a modified CRISPR-Cas9 system. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 461. doi:10.1158/1538-7445.AM2014-461
Free/Libre open-source software development: What we know and what we do not know

We review the empirical research on Free/Libre and Open-Source Software (FLOSS) development and assess the state of the literature. We develop a framework for organizing the literature based on the input-mediator-output-input (IMOI) model from the small groups literature. We present a quantitative summary of articles selected for the review and then discuss findings of this literature categorized into issues pertaining to inputs (e.g., member characteristics, technology use, and project characteristics), processes (software development practices, social processes, and firm involvement practices), emergent states (e.g., social states and task-related states), and outputs (e.g. team performance, FLOSS implementation, and project evolution). Based on this review, we suggest topics for future research, as well as identify methodological and theoretical issues for future inquiry in this area, including issues relating to sampling and the need for more longitudinal studies.
Chronic loneliness and television use

The study examined how chronic loneliness influenced local news and soap opera viewing. We hypothesized that chronic loneliness relates to reduced interpersonal interaction, increased electronic media use, and passive television use. The discriminant analysis distinguished chronic loneliness from nonloneli‐ness by: (a) lesser use of interpersonal channels and greater use of electronic media channels, especially television and movies; and (b) pass time viewing motivation. We discussed the implications of the results and related the findings to the links between personal and mediated communication.
Beyond Public Opinion Polls: Punitive Public Sentiment & Criminal Justice Policy

The punitive turn in criminal justice policy, epitomized by policies like three-strikes, truth in sentencing, and mandatory minimums, is often attributed in part to demand for harsher criminal justice responses from an increasingly punitive public. It has been argued that public opinion, known to be both largely uninformed and often misunderstood, might both indirectly and directly affect policy. This survey article on punitiveness in public opinion opens with a discussion of competing depictions of the nature of the relationship between a punitive public and increasingly punitive criminal justice policies. The article then focuses on some of the most influential explanations for variations in punitiveness within individuals and across groups. A review of what we know about public attitudes toward punishment and a brief explanation of how we know what we know (e.g. the methodologies by which we gauge public opinion) follow. The article concludes with the observation that as methodologies continue to improve and the literature in this area continues to grow, so too does our understanding of punitive public opinion in all of its complexity.
Development of a proof-of-concept aircraft smart control system

Hutapea et al (Aircraft Engineering and Aerospace Technology: 80(4), 439–444, 2008) proposed an actuation system based on shape memory alloy springs for a wing flap of an aircraft. A continued research and development of these previously demonstrated smart flight control mechanisms was performed with the goal to develop a proof-of-concept shape memory alloy (SMA) actuation system, which utilizes SMA springs to control the six degrees of freedom of an aircraft. As a significant advancement to the overall actuation system, an air burst-cooling system was added to increase the cooling rate of the SMA springs by means of forced convection. A one-sixth scale proof-of-concept model was constructed to demonstrate and to verify the final actuation system design.Copyright © 2009 by ASME
A unifying logic-based formalism for semantic data models

Contrary to the Relational, Hierarchical, and Network Data Models which represent an application's semantics implicitly in a particular data structure, Semantic Data Models implement well-known data abstractions (i.e. aggregation, isa, association, and collection) in order to represent the semantics explicitly. A common formalism represents a framework in which data model formalisms can be transcribed and provides a uniformity useful for theoretical investigations. In this paper a first-order logic is introduced as a common formalism for analyzing Semantic Data Models. A schema is viewed as a first-order theory and the database as a model of this theory. Relations in the logic correspond to the data abstractions mentioned and axioms are given which describe their properties. Every schema contains these 'general' axioms in addition to those specific to the real-world application. The presence of the 'general' axioms provides a logical environment in which schemas can be developed. Exploiting its proof theory, the logic provides a natural mechanism with which schema consistency and schema information content are examined. The notion of a semantic database domain is introduced to provide a set-theoretic basis for the logic formalism.
Base sequence effects in double-helical DNA. II. Configurational statistics of rodlike chains.

Matrix generator techniques have been adapted to account for precise structural features of the nucleotide repeating unit and to translate the primary sequence of DNA base pairs into three-dimensional structures. Chains have been constructed to reflect the local sequence-dependent differences of bending and twisting of adjacent residues and various overall chain properties, including the average unperturbed moments of the end-to-end vector r and the mean angular orientation (〈γ〉 between base pair normals, 〈ϕ1〉 between long axes, and 〈ϕ2〉 between short axes) of terminal chain residues, have been computed. The chain backbone is treated implicitly in terms of the spatial fluctuations of successive base pairs. Motions are limited to low-energy perturbations of the standard B-DNA helix. Approximate potential energy schemes are used to represent the rules governing the patterns of local base–base morphology and flexibility. Theoretical predictions are compared with experimental observations at both the local and the macro-molecular level. Initial applications are limited to the rodlike poly(dA) · poly(dT) and poly(dG) · poly(dC) helices. The former duplex is found to be more compressed and the latter more extended than random-sequence DNA of the same chain length. The flexibility of the duplexes as a whole is described in terms of the average higher moments of the displacement vector ρ = r - 〈r〉 and the likelihood of chain cyclization is estimated from the three-dimensional Hermite series expansions of the displacement tensors. Emphasis is placed on theoretical methodology and the practical relevance of the calculated chain moments to observed physical properties.
Managerial and Peer Influence on Ethical Behavioral Intentions in a Personal Selling Context

This article evaluates the relationship between the ethical behavioral intentions of 374 future salespeople and the ethical climate of the firm. The ethical philosophy (high or low) of top management, immediate sales managers, and the peers of potential sales people were examined to see if they influenced: (1) comfort levels with the philosophy of the firm and (2) likelihood of engaging in unethical sales behavior. Ethical behavior measures included 14 situations such as deceptive sales tactics, deceptive pricing, and unethical behavior toward the employer.
Failure Mechanism Study of GaAs MODFET Devices and Integrated Circuits

GaAs Modulation Doped Field Effect Transistor (MOD-FET) integrated circuits have been accelerated stress tested under bias at 150°C, 200°C, 210°C. The failure mode has been identified to be a diffusion controlled degradation of the 2 DEC layers. Alpha particle irradiation resulted in a decrease in charge collection efficiency, and catastrophic gate burnout.
Three factor analysis of essential leaf oils in selected Persea species

Abstract A three-dimensional computer correlation of the components of the leaf oils of Persea established a clear association between the profiles of distribution of these components with taxonomic relationships based on morphology and on graft-and-hybridization compatibilities.
Broader and deeper A study of newsroom culture in a time of change

This essay offers an ethnographic analysis of The Daily Times,1 a mid-sized American corporately owned newsroom. During the period under study, a new editor changed the way that reporters produced ...
Microstimulation of auditory nerve for estimating cochlear place of single fibers in a deaf ear

Multielectrode cochlear prostheses seek to approximate the cochlea's normal frequency-place mapping through spatial segregation of stimulus currents. Various electrode configurations have been employed to achieve such segregation. Direct measurements of stimulation regions among single auditory nerve (AN) fibers has been possible only when normal hearing is preserved, such that each fiber's cochlear place can be inferred from its tuning curve. This precludes measurements in deafened ears, or ears compromised by implantation of the electrodes. Data presented here demonstrate that the cochlear place of an AN fiber can be estimated without acoustic sensitivity, using electrical microstimulation through a recording pipette in the AN bundle. The procedure exploits cochleotopic projection to isofrequency laminae within the contralateral inferior colliculus (IC). Microstimulation excites a small group of fibers neighboring the recorded fiber, generating centrally propagated volleys along a narrow frequency-specific pathway. Evoked potential recordings at varying depths are made to identify the ICC lamina where the response to AN microstimulation is greatest. Preliminary data are also presented for an alternative method of identifying the lamina using a frequency domain measure of binaural interactions within the IC.
207PB NMR and monte carlo studies of ionic solid solutions

Lead, strontium and barium nitrates, like the titanates of the same cations, form a continuous set of solid solutions. 207 Pb NMR spectra of mixed crystals of lead/strontium nitrate and lead/barium nitrate each show up to 13 lines, arising from lead ions with from zero to twelve Pb 2+ nearest-neighbor cations replaced by Sr 2+ or Ba 2+ . In the case of (Pb,Sr)(NO 3 ) 2 these shifted lines are further split by the multiplicity of inequivalent nearest-neighbor replacements. The average shift per Sr 2+ ion is 21.8 ppm; that for Ba 2+ is smaller. Using Monte Carlo/Metropolis calculations, the intensities of the resonances can be fit to statistical models of Pb 2+ and Sr 2+ ion distributions, and used to probe the microenergetics of solid solution formation. The data can be satisfactorily fit by distributions in which the cations are slightly clustered, with like pairs of nearest neighbors being favored by 120 J/mol over unlike pairs. Interestingly, this finding is inconsistent with the conventional interpretation of powder diffraction results for the mixed crystals, where the dependence of lattice parameter on composition shows a slight positive curvature, generally held to indicate a favorable interaction between unlike ions.
Hydrodynamic theory for spatially inhomogeneous semiconductor lasers. II. Numerical results

We present numerical results for the diffusion coefficients (DCs) in the coupled diffusion model derived [J. Li and C. Z. Ning, preceding paper, Phys. Rev. A 66, 023802 (2002)] for a semiconductor quantum well. These include self- and mutual-diffusion coefficients in the general two-component case, as well as density- and temperature-related DCs under the single-component approximation. The results are analyzed from the viewpoint of the free Fermi gas theory with many-body effects incorporated. We discuss in detail the dependence of these DCs on densities and temperatures in order to identify different roles played by the free-carrier contributions including carrier statistics and carrier\char21{}LO-phonon scattering, and many-body corrections including band-gap renormalization and electron-hole $(e\ensuremath{-}h)$ scattering. In the general two-component case, it is found that the self- and mutual-diffusion coefficients are determined mainly by the free-carrier contributions, but with significant many-body corrections near the transition density where carrier statistics changes from the Maxwell to the Fermi-Dirac distribution. Carrier\char21{}LO-phonon scattering is dominant at low density, whereas e-$h$ scattering becomes important in determining their density dependence above the electron transition density. In the single-component case, it is found that many-body effects decrease the density coefficients but enhance the temperature coefficients. The modification is on the order of $10%$ and reaches a maximum of over $20%$ [C. Z. Ning and J. Li, Phys. Rev. B $65,$ 201305(R) (2002)] for the density coefficients. Overall, temperature elevation enhances the diffusive capability of carriers (DCs) linearly, and such an enhancement grows with density. The complete data set of various DCs as functions of carrier densities and temperatures provides necessary ingredients for future applications of the model to various spatially inhomogeneous optoelectronic devices.
Gefiltin in zebrafish embryos: sequential gene expression of two neurofilament proteins in retinal ganglion cells

Neurogenesis is correlated with the progressive synthesis of diverse neuronal intermediate filaments (IF) proteins. This apparent developmental regulation of IF protein gene expression suggests that specific neurofilament proteins impart unique structural attributes that support the staged growth of the neuron. In the teleost visual pathway, the sequential expression of two IF genes, plasticin and gefiltin, is linked to the age of retinal ganglion cells (RGCs) and to the regeneration of optic axons after nerve injury. Given this pattern of plasticin and gefiltin expression, we hypothesized that the two proteins would be sequentially expressed in zebrafish retina during development. We analyzed the pattern of gefiltin expression during zebrafish development and compared it to our previous determination of plasticin expression (Canger et al. 1998). Gefiltin is expressed after plasticin, during the later stages of retinal development when axons grow past the optic chiasm and innervate their targets. Thus, during RGC development, expression of plasticin and gefiltin resembles that with optic nerve regeneration. Outside of the visual pathway, gefiltin is predominantly expressed in the central nervous system whereas plasticin is primarily expressed in the peripheral nervous system. These results suggest that the expression of these genes is regulated in a neuron-specific manner. In addition, since plasticin and gefiltin are co-expressed during RGC development, these findings suggest a more complex mechanism of transcriptional regulation which orchestrates the sequential expression of these genes.
NUCLEATION AND GROWTH IN THE DIFFUSION CLOUD CHAMBER II STEADY STATE NUCLEATION

Abstract A model describing nucleation and growth in a thermal diffusion cloud chamber presented earlier in this Journal to explain oscillatory nucleation is extended to the case of steady state nucleation. The model is applied to nucleation rate data for ethanol vapor obtained using a thermal diffusion cloud chamber. A correction is made for the deleterious effects of vapor depletion and latent heat generation which accompany droplet growth thus extending the accessible range of nucleation rate measurements by several orders of magnitude.
Effects of baclofen on synaptically-induced cell firing in the rat hippocampal slice.

The effects of baclofen on the synaptically-induced firing of pyramidal and granule cell populations were tested in the rat hippocampal slice. Population spikes were evoked by stimulating excitatory pathways in the presence and absence of bath-applied drug. (+/-)-Baclofen (20 microM) completely blocked the firing of CA1 or CA3 hippocampal pyramidal cells subsequent to stimulation of projections that originate in area CA3. In contrast, the firing of dentate granule cells evoked by stimulation of the perforant path fibres was depressed by only 46% and baclofen did not affect the monosynaptic firing of CA3 pyramidal cells evoked by mossy fibre stimulation. These results are consistent with the effects of baclofen on the corresponding extracellularly-recorded excitatory postsynaptic potentials (e.p.s.ps). The Schaffer collateral-commissural population spike in area CA1 was depressed by (-)-baclofen (EC50 = 2.8 microM), GABA (EC50 = 2.2 mM) and 3-aminopropanesulphonic acid (3-APS) (EC50 = 0.34 mM). (-)-Baclofen was 180 times as potent as (+)-baclofen. Bicuculline methiodide (100 microM) did not reverse the depressant action of (-)-baclofen. GABA-induced depressions were antagonized to only a small degree, whilst the effect of 3-APS was readily reversed. Raising the concentration of bicuculline from 100 microM to 500 microM did not further reverse the action of GABA. The effects of (-)-baclofen and 3-APS on the relationship between extracellular e.p.s.p. and population spike were tested by stimulation of the Schaffer collateral-commissural fibres in area CA1. (-)-Baclofen shifted the 'input/output' curve to the right at a concentration of 1 microM, but less or not at all at 3 microM. In contrast, increasing the concentration of 3-APS shifted this curve farther to the right.
Computer analysis of Feynman diagrams for a static model

Abstract A computer program, written in fortran , which constructs and computes Feynman diagrams for the charged scalar static model is described.
Lack of c-kit receptor promotes mammary tumors in N-nitrosomethylurea-treated Ws/Ws rats.

Background c-kit is expressed in various cell types during development and it has been linked to the promotion of cellular migration, proliferation and/or survival of melanoblasts, hematopoietic progenitors and primordial germ cells. Several reports have proposed a role for the c-kit gene on carcinogenesis. Gain-of-function mutations are associated with diseases such as mastocytosis and gastrointestinal stromal tumors among others. However, very little is known about pathologies associated with loss-of-function mutations. Regarding breast cancer, c-kit protein and mRNA are highly expressed in normal breast but their expression decreases or is absent in the presence of breast cancer. We studied the role of c-kit in mammary carcinogenesis in the Ws/Ws rats carrying spontaneous lack-of-function mutation in the c-kit gene. Fifty day-old virgin female Ws/Ws rats and their wild type counterparts were injected with either 50 mg/kg body weight of the chemical carcinogen N-nitrosomethylurea or with vehicle. The animals were followed-up for 6 months. Fisher 344 rats were used as positive controls for tumor development.
EPR study of photochemical reactions of fac- and mer-[Cr(CO)3(η1-L2)(η2-L2)]+ (L2 = bidentate phosphine, arsine, or phosphonite ligand)

Rearrangement of fac-[Cr(CO) 3 (η 2 -L 2 )(η 1 -L 2 )] + to mer-[Cr(CO) 3 (η 2 -L 2 )(η 1 -L 2 )] + (L 2 is a bidentate phosphine or arsine ligand) is a rapid thermally activated process. Loss of CO from mer-[Cr(CO) 3 (η 2 -L 2 )(η 1 -L 2 )] + to form trans-[Cr(CO) 2 (η 2 -L 2 ) 2 ] + is shown to be a clean photochemical process, perhaps the first example of a quantitative photochemical transformation for a Cr(I) complex. The bidentate phosphonite ligand, L 2 = (MeO) 2 PCH 2 CH 2 P(OMe) 2 , behaves quite differently: fac-[Cr(CO) 3 (η 2 -L 2 )(η 1 -L 2 )] + undergoes photochemical loss of CO to form a five-coordinate complex which converts slowly via thermal activation to trans-[Cr(CO) 2 (η 2 -L 2 ) 2 ] + .
Lack of correlation between histologic findings and response to chemotherapy in metastatic breast cancer.

A retrospective analysis was undertaken to assess the prognostic role of histologic findings in response to chemotherapy and survival in patients with metastatic breast cancer. Histologic material was available for 395 of 1587 patients treated for metastatic breast cancer at the M.D. Anderson Cancer Center between 1973 and 1984. Chemotherapy consisted of 5-fluorouracil, doxorubicin, and cyclophosphamide or similar drugs, with or without tamoxifen. Maintenance cyclophosphamide, methotrexate, and 5-fluorouracil was continued for 2 years after a cumulative doxorubicin dose of 450 mg/m2 was administered. The histologic distribution was as follows: infiltrating ductal carcinoma, 353; invasive lobular, 14; mixed histology, ten; mucinous, seven; signet ring, four; tubular, three; papillary, two; sarcomatoid, one; and apocrine, one. Because individual histologic types occurred infrequently, the patients were divided into infiltrating ductal and nonductal groups. Baseline patient characteristics included age, performance status, estrogen-receptor status, prior hormone response, disease extent, and levels of alkaline phosphatase, bilirubin, and lactate dehydrogenase. These were similar in the two groups. Significantly more patients with nonductal histology had greater than three metastatic sites. There were also more patients with hemoglobin less than 10 mg/dl and albumin less than 3.5 mg/dl in the nonductal group of patients. However, statistically these factors did not have an impact on the results. There was a 63% response rate (17% complete and 46% partial) for the ductal group and a 60% response rate (12% complete and 48% partial) for the nonductal group. The time from initiation of chemotherapy to disease progression was identical (12 months) for the two groups. Survival from initiation of chemotherapy was not significantly different (22 months for ductal and 27 months for nonductal). Based on this study, the authors conclude that histologic findings have no bearing on patient response to chemotherapy or survival in metastatic breast cancer.
highwire , rpm-1 , and futsch : Balancing Synaptic Growth and Stability

HIW/RPM-1 and Futsch can thus be added to the growing repertoire of proteins involved in the modulation of synaptic growth. The available evidence suggests that these processes are under both positive and negative regulation, and HIW/RPM-1 and Futsch play roles in this regulation. One issue of interest will be to determine what genes are upstream and downstream of these proteins in fly and worm and thus define a signaling cascade that modulates synaptic growth and plasticity. The large size and multiple domains of HIW/RPM-1 and Futsch may allow these proteins to complex with several others in presynaptic terminals. A second issue of interest, then, will be to determine how these protein complexes are assembled in periactive zones. The different phenotypes observed in motor versus sensory and other neurons in rpm-1 mutants raises the possibility that these protein complexes in periactive zones may differ among different neurons, perhaps reflecting the wide variety of signaling interactions with potential postsynaptic targets.A third issue is whether HIW/RPM-1 homologs in addition to hPam exist in vertebrates, whether periactive zone domains exist in vertebrate presynaptic terminals, and whether these have similar functions as those in fly and worm. Two proteins shown to be localized to presynaptic terminals in rodents, Bassoon and Piccolo/Aczonin, also contain two zinc finger domains, as do HIW/RPM-1 (cf. Fenster et al. 2000xFenster, S.D., Chung, W.J., Zhai, R., Cases-Langhoff, C., Voss, B., Garner, A.M., Kaempf, U., Kindler, S., Gundelfinger, E.D., and Garner, C.C. Neuron. 2000; 25: 203–214Abstract | Full Text | Full Text PDF | PubMedSee all ReferencesFenster et al. 2000), but the in vivo functions of these proteins are presently unknown.Finally, it will be interesting to explore how activity-dependent regulation of synaptic growth may be linked to HIW/RPM-1 and Futsch function. While studies in worm, fly, and mouse show that presynaptic activity is not required for synapse formation (cf. Verhage et al. 2000xVerhage, M., Maia, A.S., Plomp, J.J., Brussaard, A.B., Heeroma, J.H., Vermeer, H., Toonen, R.F., Hammer, R.E., van den Berg, T., Missler, M. et al. Science. 2000; 287: 864–869Crossref | PubMed | Scopus (743)See all ReferencesVerhage et al. 2000), synaptic growth and stabilization are modulated by neural activity. Combining genetics with structural and functional analyses at the molecular and cellular levels will expand our understanding of how neural activity, and other signals, tip the balance between synaptic growth and stability during development as well as in adulthood.*To whom correspondence should be addressed (e-mail: rbaliceg@mail.med.upenn.edu).
Linking molecular and cellular events in T-cell activation and synapse formation

The complex sequence of events in which T cells recognize foreign entities on other cells is not well understood. However, the development of new techniques and approaches in both the molecular and cellular aspects of this problem have provided significant insights into the mechanisms of T-cell recognition and synapse formation. In particular, we have a clearer picture of T-cell sensitivity, the role of co-stimulation in formation of the immunological synapse, and how TCR signaling acts to maintain synapse structure and potentiate the T cells over many hours of engagement. We also are aware of new complexities in the way T-cell receptor molecules bind peptide-MHC (pMHC) ligands and what that may mean for TCR scanning, cross-reactivity, and activation. Ultimately, we want to integrate these cellular aspects of T-cell recognition with key features of the molecular interactions that drive specific events.
Pelvic radiation improves local control after hysterectomy for uterine leiomyosarcoma: a 20-year experience.

Background: Uterine leiomyosarcoma (LMS) is associated with high rate of recurrence after surgical resection. The role of adjuvant radiation therapy in improving survival in women with uterine LMS is unclear. Methods: All cases of LMS treated from 1985 to 2005 at 11 regional medical centers were identified. Kaplan-Meier survival curves were constructed and compared with log-rank testing. Multivariate analysis was performed to account for the potential influence of confounding factors. Results: One hundred forty-seven patients with LMS were identified. The median age of diagnosis was 51 years with the stage distribution of stage I (n = 87), II (n = 9), III (n = 25), IV (n = 25), and unknown (n = 1). One hundred forty-three underwent total abdominal hysterectomy and bilateral salpingoophorectomy. Twenty-four (17%) of these patients received adjuvant pelvic irradiation, and 63 (44%) received adjuvant and/or palliative chemotherapy. With a median follow-up of 24 months (range, 1-249 months), the median survival for the entire group was 37 months. Cox proportional hazards modeling demonstrated the presence of high tumor grade and advanced stage adversely affected survival. Although the 5-year survival for patients who received adjuvant radiotherapy was significantly higher than those who did not (70% vs 35%), this survival advantage was not sustained as the curves crossed at 90-month follow-up. Pelvic recurrence rate was lower in the radiation group (18% vs 49%; P = 0.02). Conclusions: Adjuvant radiation therapy was associated with decreased pelvic failure and a modest improvement in 5-year survival, but did not impact overall survival with extended follow-up.
Tissue residues and metabolism of narasin in chicken

Chickens were fed 50 ppm [ 14 C]narasin rations. After 5 days, the chickens were sacrificed, and tissues were taken for assay. Tissues were assayed for total radioactivity by solubilization and liquid scintillation counting. The mean residue concentrations of narasin equivalents were 0.32 ppm in liver, 0.12 ppm in fat, 0.08 ppm in skin/fat, 0.04 ppm in kidney, and <0.04 ppm in muscle. Liver radioactivity was isolated by liquid-liquid extractions and preparative silica liquid chromatography (LC). Radioactivity in fat was isolated and assayed by high-performance liquid chromatography/electrospray-mass spectrometry/liquid scintillation counting (HPLC/ESMS/LSC). The radioactivity in fat was characterized as being predominately parent narasin. Excreta samples were also collected for isolation, quantification, and characterization of narasin and its metabolites. Fifteen metabolites and parent narasin were characterized from the excreta of chickens using HPLC/ESMS/LSC. These metabolites were predominately di- and trihydroxylated narasin and di- and trihydroxylated narasin B. These hydroxylated metabolites represented almost 50% of the total radioactivity in excreta. The chromatographic distribution and relative magnitude of radioactivity from liver and excreta were similar, suggesting that excreta metabolites are the same as those found in liver.