cssi/SciSciGPT-SciSciNet huggingface dataset:
Differences between experts’ and students’ conceptual images of the mathematical structure of Taylor series convergence

Taylor series convergence is a complicated mathematical structure which incorporates multiple concepts. Therefore, it can be very difficult for students to initially comprehend. How might students make sense of this structure? How might experts make sense of this structure? To answer these questions, an exploratory study was conducted using experts and students who responded to a variety of interview tasks related to Taylor series convergence. An initial analysis revealed that many patterns of their reasoning were based upon certain elements and actions performed on elements from the underlying mathematical structure of Taylor series. A corresponding framework was created to better identify these elements and how they were being used. Some of the elements included using particular values for the independent variable, working with terms, partial sums, sequences, and remainders. Experts and students both focused on particular elements of Taylor series, but the experts demonstrated the efficiency and effectiveness of their reasoning by evoking more conceptual images and more readily moving between images of different elements to best respond to the current task. Instead of moving between images as dictated by tasks, students might fixate on “surface level” features of Taylor series and fail to focus on more relevant features that would allow them to more appropriately engage the task. Furthermore, how experts used their images, supports the idea that they were guided by formal theory, whereas students were still attempting to construct their understanding.
The coupled-cluster correction to multi-reference configuration interaction method: application to excited states

Abstract The multi-reference configuration interaction method applies equally well to ground and excited states. However, a disadvantage of the MR-CI scheme is that its accuracy can be seriously affected by inadequate description of dynamical electron correlation effects. This problem can be alleviated to a large extent through an a posteriori correction based on the coupled-cluster (CC) expansion. Since our correction is derived within the single-reference CC formulation, its application to excited states is less obvious although possible and fully justified. In this Letter, we explore this possibility and study the performance of the correction for excited states.
The tracy pumping plant

THE TRACY PUMPING PLANT, now being completed, is located on the Delta-Mendota Canal near Tracy, Calif. It is one of a series of works to provide an adequate supply of water to the lower San Joaquin Valley from the Sacramento-San Joaquin Delta. At one time a considerable acreage in this area was placed under cultivation by irrigation. Much of this irrigation was from wells which in time lowered the water table, depleted supplies, and in some cases necessitated abandonment of cultivation. Diversion of water by the Friant Dam to the upper San Joaquin has further reduced supplies available to the lower valley.
Open tube vapor transport growth of Pb1−xSnxTe epitaxial films for infrared detectors

Epitaxial films of Pb1−xSnxTe have been grown by open tube vapor transport on (100) Pb1−xSnxTe substrates. The as-grown films are suitable for detector array fabrication with respect to both surface smoothness and electrical properties. Charge compositions from 1% excess metal to 1% excess Te were used. Growth rates up to 3–4 ym per hour were achieved. The asgrown carrier concentrations varied from 3 × 1016cm−3 to 3 × 1017cm−3 depending on growth temperature and charge composition. Schottky barrier detectors with semi-transparent electrodes were fabricated on as-grown layers with no surface preparation. Good uniformity of detector parameters was obtained with arrays of 20 to 40 elements. The array size is not limited by either substrate size or epitaxial quality. Resistance-area products on the order of 1 ohm-cm were obtained at 77 K for detectors with a 12 ym long wavelength cutoff. Quantum efficiencies for 8–12 urn radiation were 40–50%. Peak response and 50% cutoff occurred at 11 and 12 ym, respectively. Uniformity of cutoff wavelength across the arrays of ± 0.1 ym was obtained.
The failure of Education for All as political strategy

Since 1990 the education development community has focused on a strategy titled: Education for All. This article argues that, as political strategy, it has been a failure. The article explains why and suggests ways to correct the problem.
THE ENZYMATIC AND VITAGEN PROPERTIES OF UNSATURATED FATS AS THEY INFLUENCE THE DIFFERENTIATION OF CERTAIN PLANT TISSUES

AS A continuation of earlier work by the author, the present paper elaborates upon the internal distribution of unsaturated fats and associated enzymes in relation to the differentiation of certain types of plant cells. The formation and deposition of unsaturated fats are predominantly localized in the epidermis, hypodermis, endodermis, mestome or bundle sheath, trabecular cells and integument cells, all of which are essentially dermal structures. Certain characteristic physico-chemical relations in and near these dermal structures evidently underlie their structural differentiation. Special consideration is given to the reactions which determine whether or not an endodermis is formed. Incidental reference is made to the functional role of the endodermis. Preliminary work on certain vitamins as they influence the vitagen (Rosenberg, 1942) action of unsaturated fats in the development of some tissues is reported. GENERAL NATURE AND DETECTION OF THE FAT SYSTEM IN DERMAL TISSUES.-It is generally recognized that unsaturated fats have a tendency to oxidize. Several workers have demonstrated that this oxidation may be accelerated by an unsaturated fat oxidase system (Tauber, 1940; Strain, 1941; and Van Fleet, 1942b, 1943). The rate of oxidation of fats may be influenced by the hydrion concentration and by various pro-oxidants and antioxidants (Bradway and Mattill, 1934; Olcott and Mattill, 1936; and Van Fleet, 1942b). For a complete description of the exact mechanism of fat oxidation in plant tissue see Van Fleet, 1942b. The oxidation system in dermal tissues may be detected by application of buffered alkaline solutions (pH 7.8-8.2) and suitable indicators to fresh or frozen freehand or sliding microtome sections. The indicators found to be best adapted to this work are guaiacol, the reduced or leuco form of thionin, leuco methylene blue, leuco indigo carmine, leuco cresyl blue, "Nadi" and "Dopa." Through the application of alkali, particularly sodium selenite (Van Fleet, 1942b, 1943), the unsaturated fats are freed from inhibitols so that immediate oxidation takes place, and at the same time oxidation in other surrounding tissues is held in an inactivated state by the alkali. The term inhibitol is used here to denote all naturally occurring substances that are alkali-labile and related to a-tocopherol (Golumbic, 1941) or other possible unknown vitamin or related substances (see Mattill and co-workers). The term antioxidant signifies all artificially introduced or naturally occur-
HSV-Mediated Delivery of Erythropoietin Restores Dopaminergic Function in MPTP-Treated Mice

To investigate the neuroprotective effects of erythropoietin (EPO) in a rodent model of Parkinson disease, we inoculated a nonreplicating herpes simplex virus-based vector expressing EPO (vector DHEPO) into the striatum of mice 1 week prior to, or 2 weeks after, the start of continual administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (4 mg/kg intraperitoneally, 5 of 7 days) for 6 weeks. Inoculation with DHEPO prior to MPTP intoxication preserved behavioral function measured by pellet retrieval and the histological markers of tyrosine hydroxylase-immunoreactive (TH-IR) neuronal cell bodies in the substantia nigra (SN) and TH-IR and dopamine transporter-immunoreactive (DAT-IR) terminals in striatum. Inoculation of DHEPO 2 weeks into a 6-week course of MPTP resulted in improvement of behavioral function and restoration of TH-IR cells in SN and TH- and DAT-IR in the striatum. The effects of vector-produced EPO were similar in magnitude to the effects of vector-mediated expression of glial-derived neurotrophic factor in the same model. These results demonstrate that vector-mediated EPO production may be used to reverse dopaminergic neurodegeneration in the face of continued toxic insult.
A class of iterative techniques for the factorization of polynomials

A method of iteration is developed in terms of a function of somewhat arbitrary character. Sufficient conditions are given for convergence of the process, yielding factors of arbitrary degree for polynomials in one variable. Both Lin's method and Newton's method occur as special cases.
Systemic and global toxicities of head and neck treatment

The increased use of aggressive, combined modality therapy for the treatment of head and neck cancer has resulted in a marked increase in acute and late adverse effects. The acute effects of therapy have long been appreciated; however, it is now being recognized that the late effects of therapy result in a significant symptom burden, diminished functional capacity and decreased quality of survivorship. Furthermore, head and neck cancer has historically been considered a locoregional disease that is treated predominantly with locoregional therapy. It is now recognized that there are systemic effects of therapy that need to be considered. Potential systemic effects of therapy include: fatigue, weight loss, nutritional deficiencies, altered physical functioning and mood disorders. It is important for clinicians to be aware of these late effects in order to provide patients with appropriate support services and referrals. This paper examines the global and systemic effects of therapy.
A Cross-Walk of Professional Competencies Involved in Expanded School Mental Health: An Exploratory Study

Expanded school mental health (ESMH) programs often involve individuals from a variety of professions working together to address student needs evident across school, family, and community systems. Profession-driven differences in philosophies, expectations regarding confidentiality, and graduate training that reinforces isolated rather than interprofessional approaches to working with students, however, represent real challenges to maximizing the potential of ESMH. To address these issues, this exploratory study identified a common set of competencies to support interprofessional practice in ESMH. A total of 51 competencies were identified across seven theme areas, including: (1) Key Policies and Laws; (2) Interprofessional Collaboration; (3) Cross-Systems Collaboration; (4) Provision of Academic, Social-Emotional, and Behavioral Learning Supports; (5) Data-Driven Decision-Making; (6) Personal and Professional Growth and Well-Being; and, (7) Cultural Competence. Mapping of the competencies to existing accreditation and practice standards for selected professions revealed shared and unique competencies. Implications for workforce development and future research are offered.
Global implications of national unconventional policies: A comment

Abstract This comment discusses “Global Implications of National Unconventional Policies” by L. Dedola. P. Karadi and G. Lombardo, which was presented in Carnegie-Rocherster conference in April 2012.
A Cytoplasmic Substrate of Mitogen-Activated Protein Kinase Is Responsible for Estrogen Receptor-α Down-Regulation in Breast Cancer Cells: The Role of Nuclear Factor-κB

Estrogen receptor alpha (ERalpha) negative breast tumors often present with enhanced expression and/or activation of growth factor receptors, resulting in increased growth factor signaling and hyperactivation of MAPK (ERK1 and ERK2). We have pre-viously shown that ERalpha(+) MCF-7 cells with elevated growth factor signaling lose expression of ERalpha without any ligand-independent transcriptional activation, and this is a reversible effect attributable to ERK1/2 hyperactivation. Here, we show that down-regulation of ERalpha is not mediated by a specific ERK-1 vs. ERK-2 substrate. Despite up-regulated activator protein-1 activity in response to ERK1/2 activation, and in ERalpha(-) and hormone-independent breast cancers, we find that increased activator protein-1 activity is not responsible for ERalpha down-regulation. Interestingly, our findings implicate a cytoplasmic substrate of ERK1/2. However, RSK1, the best-characterized cytoplasmic ERK1/2 substrate, does not down-regulate ERalpha in our models. On the other hand, inhibition of nuclear factor-kappaB (which is linked to chemoresistance in cancer in general and has elevated activity in hormone-independent and ERalpha- breast cancer) significantly enhances ERalpha activity, suggesting that indirect elevation in nuclear factor-kappaB activity (due to hyperactive ERK1/2) is at least partially responsible for ERalpha down-regulation in these cell line models.
Effect of Catalytic Activity on the Metallic Nanoparticle Size Distribution: Electron-Transfer Reaction between Fe(CN)6 and Thiosulfate Ions Catalyzed by PVP−Platinum Nanoparticles

The electron-transfer reaction between hexacyanoferrate(III) ions and thiosulfate ions is known to be catalyzed by platinum nanoparticles. In the present study, the stability and catalytic activity of the PVP−Pt nanoparticle during its catalytic function for this electron-transfer reaction is studied. The stability of the nanoparticles after various perturbations was assessed using TEM, and the kinetics of the reaction was followed using absorption spectroscopy. The studies were conducted on four different concentrations of PVP−Pt nanoparticles. It was found that the average size and width of the PVP−Pt nanoparticles decrease slightly after the first and second cycles of the electron-transfer reaction. The size and size distribution width do not change in the presence of only the thiosulfate reactant, whereas the presence of only the hexacyanoferrate reactant results in a reduction of the nanoparticle size. The reduction in the nanoparticle size in the presence of hexacyanoferrate(III) ions is proposed to...
More on the uniform rule: Characterizations without Pareto optimality

Abstract We consider the problem of allocating an infinitely divisible commodity to agents with single-peaked preferences. We propose various characterizations of the allocation rule known as the uniform rule without imposing Pareto optimality . We also present new computational characterizations of the rule.
Alcoholic Cardiomyopathy: Pathophysiologic Insights

Alcoholic cardiomyopathy (ACM) is a specific heart muscle disease found in individuals with a history of long-term heavy alcohol consumption. ACM is associated with a number of adverse histological, cellular, and structural changes within the myocardium. Several mechanisms are implicated in mediating the adverse effects of ethanol, including the generation of oxidative stress, apoptotic cell death, impaired mitochondrial bioenergetics/stress, derangements in fatty acid metabolism and transport, and accelerated protein catabolism. In this review, we discuss the evidence for such mechanisms and present the potential importance of drinking patterns, genetic susceptibility, nutritional factors, race, and sex. The purpose of this review is to provide a mechanistic paradigm for future research in the area of ACM.
New formulation of FEM for deterministic and stochastic beams through generalization of Fuchs' approach

This paper proposes an alternative way of constructing the global stiffness matrix of the finite element method for bending beams, it also applies the new formulation to first and second moment analysis of stochastic beams, which involve spatially uncertain bending stiffness. Originating from Fuchs' idea of decoupling the shear and bending components in the bending beam, the element level stiffness matrix is diagonalized. The generalized stress-strain, strain-displacement and equilibrium relationships are assembled, respectively, and then are combined to form the global stiffness matrix. The advantage of the new formulation is that the bending stiffness explicitly appears in the global stiffness matrix. The mean vector and covariance matrix of the displacement of the beam are then obtained in terms of probabilistic characteristics of the uncertain bending stiffness. This is in contrast to the conventional finite element method in stochastic setting, which is based on the perturbation technique. The example is given to illustrate the efficacy of the new formulation and its application to bending of stochastic beams.
Extensive heterogeneity in white matter intensity in high-resolution T2*-weighted MRI of the human brain at 7.0 T.

Abstract MRI at high magnetic field strength potentially allows for an increase in resolution and image contrast. The gains are particularly dramatic for T 2 * -weighted imaging, which is sensitive to susceptibility effects caused by a variety of sources, including deoxyhemoglobin, iron concentration, and tissue microstructure. On the other hand, the acquisition of high quality whole brain MRI at high field is hampered by the increased inhomogeneity in B o and B 1 fields. In this report, high-resolution gradient echo MRI was performed using an 8-channel detector to obtain T 2 * -weighted images over large brain areas. The high SNR achieved with the multi-channel array enabled T 2 * -weighted images of the brain with an unprecedented spatial resolution of up to 0.2 × 0.2 × 0.5 mm 3 . This high resolution greatly facilitated the detection of microscopic susceptibility effects. In addition to the expected contrast between gray, white matter, cerebral spinal fluid, and veins, a large degree of heterogeneity in contrast was observed throughout the white matter of normal brain. The measured T 2 * values in white matter varied as much as 30% with some of the variation apparently correlating with the presence of large fiber bundles.
Single-unit and slow potential responses from rat frontal cortex during associative conditioning

Single-unit and slow potential responses were recorded from the frontal cortex of unanesthetized, restrained rats trained to associate an auditory cue (tone) with rewarding medial forebrain bundle stimulation. Slow potential responses to the unpaired tone were minimal whereas large negative slow potential responses developed to the paired tone. Units were selected which had large-amplitude action potentials and positive first deflections, characteristics suggesting that the recordings were derived from pyramidal neurons. Responses of excitation, inhibition, and no change were observed during tone presentation. Forty-five percent of the units responded to the unpaired tone; with pairing, 90% of the units demonstrated significant responses. Furthermore, the magnitude of the excitatory responses was enhanced by pairing and a distribution pattern developed in which the overall response of the more superficial units was activation whereas deeper units were inhibited. The results suggest that the conditioning-related negative slow potential responses recorded from the surface of the rat frontal cortex reflect excitatory processes which are associated with an enhanced firing rate of neurons in the upper layers.
Future Directions for Advancing Issues in Children’s Mental Health: A Delphic Poll

The current study utilized a Delphic poll to identify significant problems regarding children and families in which psychologists can assist. The Delphic poll methodology combines both qualitative and quantitative methodologies to obtain information and predictions about the future from a panel of knowledgeable experts. Thirty-one professionals participated in the first round of the survey, and 26 participants (83.9 % of the round 1 participants) chose to complete the second-round survey. Several themes emerged consistently across questions as important issues to be addressed in the future of childhood mental health. For example, participants frequently identified access, advocacy, research and research dissemination, prevention/early intervention, and integration of services as important issues. Implications and recommendations are drawn for organizations and individual psychologists as advocates for improving children’s mental health in the United States.
Flux process for growth of large crystals with application to beryllia

Abstract A procedure is described for flux-growth of beryllia crystals, applicable to other crystals. Growth is promoted in a solvent flux by continuous transport of BeO solute in a steady-state thermal gradient. Prepared seeds are mounted on a support structure, submerged in the flux at thermal equilibrium, and rotated during the growth period. The character of growth depends on multi-parameter growth conditions including proper seed crystal structure and preparation, flux composition and impurities, temperature, and operational procedures.
Internships link user services to academic departments

To User Services people, networking the campus goes beyond laying cable and connecting hardware. We connect by establishing liaison programs, sending out surveys, and listening to feedback from vocal users, yet sometimes we still cannot get a clear focus on the needs of the academic community. Nor do we develop the trust and respect that the users need to provide us with useful feedback and needs assessments. Establishing the academic network necessary to read the pulse of the campus requires ingenuity, creativity, and sometimes just plain luck. For us in User Services at the University of Wisconsin-Eau Claire's Academic Computing Services, a successful and ongoing internship program resulted from a combination of all three. It established a link which has proven to be a real advantage for User Services, the cooperating academic departments, and the University as a whole.
Evaluating the effectiveness of automatic PVR management

A model for evaluating the effectiveness of automatic recording of television programs by digital personal video recorders (PVRs) is presented. The model is used to evaluate the tradeoff between manual management of recording programs to a PVR archive and automatic management of recording. We show that a tradeoff exists between manual management in which the utility of a program is perfectly known but user awareness of available programs is limited versus automatic management in which utility estimates contain error but awareness is perfect. Experiments with the model show that the shape of this tradeoff is most governed by the shape of the distribution of user utility. As the percentage of programs with high user utility decreases relative to the average, the more effective automatic recording is likely to be despite errors in utility estimation. The shape of this tradeoff, however, is highly inelastic. Thus, improving utility estimates will not make automatic recording more effective if user awareness is sufficiently high.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
An Interview with Edmund Campion

Edmund J. Campion was born in Dallas, Texas, in 1957. (See Figure 1.) He received a doctorate in composition at Columbia University and attended the Paris Conservatory where he worked with composer G6rard Grisey. In 1993, Campion was selected for the one-year course in computer music at the Institut de Recherche et Coordination Acoustique/Musique (IRCAM). He was eventually commissioned by IRCAM for his work Natural Selection and the evening-length dance piece Playback with choreographer Frangois Raffinot. In 1995, Hillary Clinton presented him with the Rome Prize in Music Composition at the White House.
Natural convection effect in reverse osmosis

Abstract A mathematical analysis based on boundary layer theory is presented to describe the effect of natural convection in reverse osmosis. A system consisting of a vertical membrane with a liquid stream flowing upward is considered. Since the equations of diffusion and motion are very strongly coupled, the integral technique is employed. It is shown that the effect of including the buoyancy term is to decrease the concentration polarization. Numerical results are presented for a variety of cases.
A Thermodynamic and Structural Study of the Interactions of Pyridino- and Diketopyridino-18-Crown-6 Ligands with some Primary Organic Ammonium Cations

Equilibrium constant (K), enthalpy change (ΔH), and entropy change (ΔS) values have been determined calorimetrically at 25°C in 90%MeOH 10%H2O (v/v) for the interactions of pyridino-18-crown-6 (P18C6) and diketopyridino-18-crown-6 (K2P18C6) with perchlorate salts of ammonium, benzylammonium,α-phenylethylammonium,β-phenylethylammonium, andα-(1-naphthyl)ethyl-ammonium cations. The crystal structure of the complex of P18C6 with benzylammonium perchlorate was determined by X-ray crystallography. The1H 1D and 2D NMR spectra of some of these complexes were used to elucidate their structural features in solution. The logK values for the interaction of the ammonium cations with P18C6 are larger than those with K2P18C6, probably due to the higher degree of structural flexibility of P18C6. Ligand K2P18C6 displays appreciable π-π interaction with theα-(1-naphthyl)ethylammonium cation, but not with theα-phenylethylammonium cation.
Computer Anxiety: Definition, Measurement, and Correlates:

This review examines the definition, measurement and correlates of computer anxiety as provided in available research to date. A selected review of the general anxiety construct and its measurement provides a framework for considering computer anxiety. Test anxiety and math anxiety are discussed briefly as specific anxiety manifestations with potential similarities, particularly as they relate to the educational context. Five studies are identified and discussed for their contributions to an understanding of the definition, measurement practices, and correlates of computer anxiety. It is clear from this preliminary review that more work must be done to determine if computer anxiety is a valid psychological construct and, if it is, how it should be defined, measured, and correlated with other known variables.
Quantitative Determination of Morphological and Territorial Structures of Articular Cartilage from Both Perpendicular and Parallel Sections by Polarized Light Microscopy

In order to investigate the three-dimensional structure of the collagen fibrils in articular cartilage, full-thickness canine humeral cartilage was microtomed into perpendicular sections that included both the articular surface and the subchondral bone and approximately 100 successive parallel sections that were each 6 μm thick and from a different cartilage depth. Each section was imaged using polarized light microscopy with a 5× objective (2.0 μm pixel size), generating two quantitative images (angle and retardation). Selected sections were also imaged using a 40× objective (0.25 μm pixel size). At an increased depth from the articular surface, the angle and retardation results in the perpendicular sections showed the well-known 90° change in fibril orientation between the surface and the deep cartilage. In contrast, the retardation results of the parallel sections decreased from the articular surface and remained approximately 0 through most of the radial zones, while the angle results of the parallel ...
Evaluating performance of passive distribution networks

The access network plays a major role in meeting the rapidly growing demand for higher bandwidth by transporting traffic from the long-haul network to the end users. The distribution network is part of access network that carries traffic to and from the customer premises to the feeder network. Distribution networks are usually passive with short span length. One of the major impairments in a distribution network is crosstalk which represents leaking of signal from one channel to another. Crosstalk along with various types ofnoise at the receiver degrades the quality of signal. This paper presents a qualitative and quantitative analysis of the effects of crosstalk on signal quality and system performance. The output power, worst case crosstalk, and system performance in terms of Q value are calculated for different device parameters and network configuration to evaluate the impact of crosstalk on the quality of signal and system.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Effect of a solid/liquid interface on bulk solution structures under flow

It has been known for some time that a shear field can impart enough energy to a liquid system for it to exhibit a phase change. Not as well appreciated is the fact that non Newtonian solutions can be driven into a quasi phase separation due to the vastly different shear rates between the bulk and near surface regions. Using a variety of scattering techniques the authors have probed the interfacial and near surface region of a system of wormlike colloidal particles under flow separately from the bulk. They find that the hexagonal phase which forms under flow near the surface, does not persist into the bulk. They also present data showing substantial differences in the kinetics of alignment and relaxation of the two phases.
Behavior of Atoms at the Surface of a K2O · 3siO2 Glass—A Molecular Dynamics Simulation

Recent ion scattering spectroscopy (ISS) studies indicate that an excess of K ions occurs at the surface of a K2O · 3SiO2 glass. Molecular dynamics (MD) computer simulations were used to evaluate the short-time dynamic behavior of atoms at the surface of such a glass in order to determine a mechanism for the K ion enrichment. In the simulations, a bulk glass of several hundred atoms was melted using three-dimensional periodic boundary conditions, and subsequently quenched to lower temperatures. Periodic boundary conditions were removed in one dimension near room temperature so as to create free surfaces. The distribution of species perpendicular to the free surface was determined. The MD simulations show that K ions can build up at the outermost surface of the glass within several picoseconds after formation of the surface.
Reductions of vascular endothelial growth factor and placental growth factor concentrations in severe preeclampsia

Objective: The aim of this study was to determine whether plasma concentrations of vascular endothelial growth factor and placental growth factor are altered in women with severe preeclampsia. Study Design: We performed a case-control study to compare plasma concentrations of vascular endothelial growth factor and placental growth factor between women with severe preeclampsia and normotensive women admitted for delivery. Twenty-one women with severe preeclampsia were matched for gestational age and ethnicity with 21 normotensive women. Vascular endothelial growth factor and placental growth factor concentrations were measured with a specific antigen-capture enzyme-linked immunosorbent assay. Results: Women with severe preeclampsia demonstrated significantly lower plasma concentrations of both vascular endothelial growth factor (6.36 ± 3.96 pg/mL vs 18.65 ± 5.98 pg/mL; P <.0001) and placental growth factor (138 ± 119 pg/mL vs 531 ± 340 pg/mL; P <.0001) than did women with normotensive pregnancy. Logistic regression analysis showed an independent association between plasma vascular endothelial growth factor concentration and plasma placental growth factor concentration and preeclampsia. Conclusion: Patients with severe preeclampsia had decreased maternal serum concentrations of both vascular endothelial growth factor and placental growth factor. (Am J Obstet Gynecol 2000;183:1554-7.)
Relative influence of musical and linguistic experience on early cortical processing of pitch contours

To assess domain specificity of experience-dependent pitch representation we evaluated the mismatch negativity (MMN) and discrimination judgments of English musicians, English nonmusicians, and native Chinese for pitch contours presented in a nonspeech context using a passive oddball paradigm. Stimuli consisted of homologues of Mandarin high rising (T2) and high level (T1) tones, and a linear rising ramp (T2L). One condition involved a between-category contrast (T1/T2), the other, a within-category contrast (T2L/T2). Irrespective of condition, musicians and Chinese showed larger MMN responses than nonmusicians; Chinese larger than musicians. Chinese, however, were less accurate than nonnatives in overt discrimination of T2L and T2. Taken together, these findings suggest that experience-dependent effects to pitch contours are domain-general and not driven by linguistic categories. Yet specific differences in long-term experience in pitch processing between domains (music vs. language) may lead to gradations in cortical plasticity to pitch contours.
A note on the decoupling of multivariable systems

A definition of decoupling is presented which is simple, intuitive, and which brings into the open the class of decoupling feedback matrices. Using this definition, the necessary and sufficient conditions for decoupling obtained in [1] are rederived.
Regulating discrete-time homogeneous systems under arbitrary switching

We consider discrete-time homogeneous control systems that undergo arbitrary switching. We propose an optimization-based, constructive method (which can be numerically realized) to generate a homogeneous control Lyapunov function and a homogeneous feedback law that stabilizes the origin for all possible switching scenarios. The established stability is robust with respect to small perturbations. We show that for linear systems the resulting Lyapunov function turns out to be convex. We also present a converse Lyapunov result where we state the equivalence of controllability to the origin and existence of a control Lyapunov function.
Role of a Highly Conserved NH2-Terminal Domain of the Human Parainfluenza Virus Type 3 RNA Polymerase

The RNA polymerase complex of human parainfluenza virus type 3 (HPIV 3), a member of the family Paramyxoviridae, is composed of two virally encoded polypeptides: a multifunctional large protein (L, 255 kDa) and a phosphoprotein (P, 90 kDa). From extensive deduced amino acid sequence analyses of the cDNA clones of a number of L proteins of nonsegmented negative-strand RNA viruses, a cluster of high-homology sequence segments have been identified within the body of the L proteins. Here, we have focused on the NH(2)-terminal domain of HPIV 3 L protein that is also highly conserved. Following mutational analyses within this domain, we examined the ability of the mutant L proteins to (i) transcribe an HPIV 3 minireplicon, (ii) transcribe the viral RNA in vitro using the HPIV 3 nucleocapsid RNA template, and (iii) interact with HPIV 3 P protein. Our results demonstrate that the first 15 amino acids of the NH(2)-terminal domain spanning a highly conserved motif is directly involved in transcription of the genome RNA and in forming a functional complex with the P protein. Substitution of eight nonconserved amino acids within this domain by the corresponding Sendai virus L protein residues yielded mutants with variable transcriptional activities. However, one mutant in which all eight amino acids were replaced with the corresponding residues of Sendai virus L protein failed to both transcribe the minireplicon and interact with HPIV 3 P and the Sendai virus P protein. The possible functional significance of the NH(2)-terminal domain of paramyxovirus L protein is discussed.
AN EARLY ROYAL MAYA TOMB FROM CHAN CHICH, BELIZE

In 1997, the Chan Chich Archaeological Project excavated a Terminal Preclassic/Early Classic period Maya tomb at Chan Chich, Belize. Tomb 2 represents the earliest royal tomb in the Three Rivers Region of the east-central Yucatan Peninsula and has striking similarities to Burial 85 at Tikal, the tomb of the dynastic founder Yax Ehb’ Xook. This paper describes Tomb 2 and its contents and considers its significance within the context of the significant political and cultural changes that marked the transition from the Late Preclassic to the Early Classic period. We argue that the tomb is an early example of a regional expression of elite competition for status and power in the Central Lowlands that included the use of a subcomplex of ceramics and exotic artifacts to express prestige. Tomb 2 is also an example of an early royal burial pattern that may be more widespread than believed but has been overlooked due to excavation bias. Chan Chich is a medium-to-large site for northwestern Belize. During the first season of excavations there in 1997 researchers encountered—in a fortuitously-placed test pit—a tomb carved into bedrock and buried beneath a plaza at the site (Robichaux 1998). This feature was designated Tomb 2 and became the subject of three seasons of investigations. Artifacts within the tomb and supporting stratigraphic evidence indicate Tomb 2 was most likely constructed during the Terminal Preclassic or the beginning of the Early Classic period, around a.d. 200–350. The ceramics within the tomb include forms typically associated with the “Protoclassic” period in northern Belize. For the purposes of this paper, we utilize the term Terminal Preclassic rather than Protoclassic when referring to this chronological period. In this article, we describe the discovery of Tomb 2 and its contents. We argue that it represents the earliest known royal tomb in the region and is a regional expression of an emerging pattern of elite competition in the Central Lowlands, which began earlier in the Preclassic and intensified and transformed during the Late Preclassic and Early Classic periods (e.g., Freidel and Schele 1988: 549). In particular, we examine the strong similarities between Chan Chich Tomb 2 and Tikal Burial 85, the tomb of Yax Ehb’ Xook—the founder of Tikal’s dynasty. We also discuss the possibility that Terminal Preclassic kings were more numerous than commonly believed. However, because of archaeological excavation bias and preconceptions regarding royal burial practices, many of their tombs may lie undiscovered beneath plazas and platforms.
Characterization of the localized hydrodynamic shear forces and dissolved oxygen distribution in sparged bioreactors

Detailed, high-resolution numerical simulations of the bubbly flows, used for oxygen delivery and mixing in mammalian cell suspensions, have been performed. The hydrodynamics, shear and normal forces, mass transfer and mass transport from and around individual bubbles and bubble clusters were resolved for different operating conditions, that is, Weber, Morton, and Schmidt numbers. Suspended animal (e.g., mammalian, insect) cells are known to be susceptible to damage potentially leading to cell death, caused by hydrodynamic stresses and oxygen deprivation. Better knowledge of the magnitude of the shear forces and the extent of mixing of the dissolved oxygen in sparged bioreactors can have a significant impact on their future design and optimization. Therefore, the computed liquid-phase velocity fields were used to calculate and compare the local shear in different types of single bubble wakes and in bubble clusters. Oxygen mass transfer and dissolved oxygen transport were resolved to examine oxygen supply to the cells in the different types of flows.
Experimental and simulated analysis of front versus all‐back‐contact silicon heterojunction solar cells: effect of interface and doped a‐Si:H layer defects

Front silicon heterojunction and interdigitated all-back-contact silicon heterojunction (IBC-SHJ) solar cells have the potential for high efficiency and low cost because of their good surface passivation, heterojunction contacts, and low temperature fabrication processes. The performance of both heterojunction device structures depends on the interface between the crystalline silicon (c-Si) and intrinsic amorphous silicon [(i)a-Si:H] layer, and the defects in doped a-Si:H emitter or base contact layers. In this paper, effective minority carrier lifetimes of c-Si using symmetric passivation structures were measured and analyzed using an extended Shockley–Read–Hall formalism to determine the input interface parameters needed for a successful 2D simulation of fabricated baseline solar cells. Subsequently, the performance of front silicon heterojunction and IBC-SHJ devices was simulated to determine the influence of defects at the (i)a-Si:H/c-Si interface and in the doped a-Si:H layers. For the baseline device parameters, the difference between the two device configurations is caused by the emitter/base contact gap recombination and the back surface geometry of IBC-SHJ solar cell. This work provides a guide to the optimization of both types of SHJ device performance, predicting an IBC-SHJ solar cell efficiency of 25% for realistic material parameters. Copyright © 2013 John Wiley & Sons, Ltd.
The recursive reduced-order solution of an open-loop control problem of linear singularly perturbed systems

A reduced-order method with an arbitrary degree of accuracy is obtained for solving the linear-quadratic optimal open-loop control problem. The original two-point boundary value problem is transformed into the pure-slow and pure-fast reduced-order completely decoupled initial value problems. By doing this, the stiffness of the singularly perturbed two-point boundary value problem is converted into the problem of an ill-defined linear system of algebraic equations. >
Thermal Dehydrogenation of Base‐Stabilized B2H5+ Complexes and Its Role in C ? H Borylation

Thermally induced dehydrogenation of the H-bridged cation L2B2H5+ (L=Lewis base) is proposed to be the key step in the intramolecular CH borylation of tertiary amine boranes activated with catalytic amounts of strong “hydridophiles”. Loss of H2 from L2B2H5+ generates the highly reactive cation L2B2H3+, which in its sp2-sp3 diborane(4) form then undergoes either an intramolecular CH insertion with BB bond cleavage, or captures BH3 to produce L2B3H6+. The effect of the counterion stability on the outcome of the reaction is illustrated by formation of LBH2C6F5 complexes through disproportionation of L2B2H5+ HB(C6F5)3−.
Applying graphical design techniques to graph visualisation

This paper contains details of new criteria for graph layout, based on the concepts used in graphical design. Current graph layout criteria have been shown to be effective in measuring the quality of a graph layout, but they are ad-hoc and often miss subtle appearance considerations such as balance and distribution. We discuss how the principles concerning the layout of text and diagrams from design can be applied to graph layout and show how two new metrics can be implemented based on these criteria. We also give preliminary examples of layout generated using the new metrics.
Learning to identify student preconceptions from text

Automatic classification of short textual answers by students to questions about topics in physics, computing, etc., is an attractive approach to diagnostic assessment of learning. We present a language for expressing rules that can classify text based on the presence and relative positions of words, lists of synonyms and other abstractions of a single word. We also describe a system, based on Mitchell's version spaces algorithm, that learns rules in this language. These rules can be used to categorize student responses to short-answer questions. The system is trained on written responses captured by an online assessment system that poses multiple choice questions and asks the student to justify their answers with textual explanations of their reasoning. Several experiments are described that examine the effects of the use of negative data and tagging students explanations with their answer to the original multiple choice question.
Selective peptide antagonist of the class E calcium channel from the venom of the tarantula Hysterocrates gigas.

We describe the first potent and selective blocker of the class E Ca2+channel. SNX-482, a novel 41 amino acid peptide present in the venom of the African tarantula, Hysterocrates gigas, was identif...
The OKRA leaf shape mutation in cotton is active in all cell layers of the leaf.

Oin the middle mesophyll of the lamina and the vasculature of major lateral veins (L3 derivatives) had no local effect on the expansion of the lamina, but significantly increased lobe length. These results demonstrate that L2 O is active in every tissue layer of the leaf.
Effects of Participation and Collaboration on Perceived Effectiveness of Core Public Health Functions

Objectives. We measured the perceived effectiveness of core public health services at the community level, and we assessed whether certain system factors were associated with perceived effectiveness.Methods. We used data from the National Longitudinal Survey of Local Public Health Systems, conducted in 1998 and 2006, to examine the effects of the contributions of health departments and the participation of other agencies to core functions on the perceived effectiveness of community delivery of core assessment, policy development, and assurance functions.Results. Perceived effectiveness increased over time for all 3 core function areas (range = 41%–53% in 2006). Multivariable results showed that local health department contribution to effort was positively associated with perceived effectiveness of public health core functions. The significance of participation of individual types of agencies or organizations varied by core function areas, except for local government agencies and hospitals, which were sign...
Single shot characterization of amplitude and phase of pulse-to-pulse switched optical arbitrary waveforms from a 10 GHz frequency comb

We use dual-quadrature spectral interferometry to demonstrate single shot amplitude and phase retrieval of shaped waveforms generated from a 10 GHz optical frequency comb and switched at the repetition rate of the frequency comb.
Graphitic hollow carbon calabashes

Graphitic carbon calabashes, a new structure of carbon, have been found among the solid carbon spheres synthesized by a . mixed-valent oxide-catalytic carbonization MVOCC process. The calabashes are as large as 0.8 mm and are constructed by graphitic carbon shells of thicknesses ; 10 nm. The calabash can be hollow or filled with a carbon core. Oxygen gas has been found to be trapped inside the calabashes, suggesting they could be used for gasrenergy storage. q 1998 Published by Elsevier Science B.V. All rights reserved.