cssi/SciSciGPT-SciSciNet huggingface dataset:
Atrial systole and left ventricular filling in hypertrophic cardiomyopathy: Effect of verapamil

Many patients with hypertrophic cardiomyopathy (HC) have impaired left ventricular (LV) rapid diastolic filling. To quantitate the contribution of atrial systole to LV filling, we used radionuclide angiography to study 30 normal volunteers and 42 patients with HC before and after oral administration of verapamil (320 to 560 mg/day). LV time-activity curves were constructed by combined forward and reverse gating from the R wave, and the onset of atrial systole was determined by the P-R interval. The percent of LV stroke volume filled during rapid diastolic filling and atrial systole was then computed. Peak LV filling rate during rapid diastolic filling was expressed in end-diastolic volume (EDV)/second. Peak rate of rapid diastolic filling was not different in normal patients and those with HC (3.3 +/- 0.6 versus 3.3 +/- 1.1 EDV/s) and was within the normal range in 34 patients with HC (81%). However, the contribution to LV filling volume by rapid diastolic filling was diminished in patients with HC (83 +/- 7% normal, 67 +/- 17% HC, p less than 0.001) and the contribution of atrial systole was increased (16 +/- 8% normal, 31 +/- 18% HC, p less than 0.001). LV filling volume during atrial systole was above the upper normal limit of 31% in 17 patients (40%), including 13 patients with a normal peak filling rate. After verapamil, peak filling rate increased (to 4.2 +/- 1.2 EDV/s, p less than 0.001), percent LV filling during rapid diastolic filling increased (to 83 +/- 7%, p less than 0.001), and percent LV filling during atrial systole decreased (to 16 +/- 9%, p less than 0.001). Percent LV filling volume during atrial systole was abnormal after verapamil in only 3 patients (7%). Hence, although the peak rate of rapid diastolic filling may be normal in patients with HC, the contribution to LV filling by rapid diastolic filling is reduced and that of atrial systole is thereby increased. Increased rate and magnitude of rapid diastolic filling during verapamil is associated with decrease and normalization of the contribution of atrial systole to LV filling. These data suggest that many patients with HC are at risk of hemodynamic decompensation with the onset of atrial fibrillation or other tachyarrhythmias and loss of the atrial contribution to LV filling. This risk may be reduced during verapamil therapy.
DIFFERENTIATION OF ELECTRON TRANSPORT SYSTEMS IN MITOCHONDRIA AND MICROSOMES DURING EMBRYONIC DEVELOPMENT.

Abstract Activities of various particulate-linked oxidative enzyme activities and of cytochrome components were examined in well-defined mitochondrial and microsomal fractions obtained from 24-hr. chick embryos and from heart and liver of chick embryos and chicks. Changes in relative as well as absolute levels of these components are considered in terms of the differentiation of organized electron transport chains in different tissues and within a given tissue in the course of embryonic development.
A Start-Up Scheme for a Three-Stage Solid-State Transformer With Minimized Transformer Current Response

This letter is focused on developing a start-up scheme for a three-stage solid-state transformer that includes a high-frequency transformer. The proposed scheme is aiming at minimizing the high-frequency transformer current during the start-up transient. As a result, the input-inrush current is also eliminated. The scheme is implemented with no extra cost by synchronizing the start-up of rectifier stage and dc-dc converter stage. The scheme is compared with other start-up methods. The theoretical analysis and experimental results are provided to verify the proposed start-up scheme.
Estimate of removal rate of Nereis virens (Polychaeta: Nereidae) from an intertidal mudflat by gulls ( Larus spp.)

The feeding behavior of herring gulls (Larus argentatus), ringed-billed gulls (L. delawarensis) and great blackbacked gulls (L. marinus) on an intertidal mudflat in Maine, USA, was investigated. Remains of fish, mussels, crabs, insects, and the polychaeteNereis virens were recovered from gull feces. Forty-three percent of the fecal samples containedN. virens jaws, setae, or both. A comparison of jaws from fecal material and from worms collected from the natural community demonstrates that gulls preferentially preyed upon larger worms. Feeding was largely confined to 3 h around low tide, and birds fed mostly in the low intertidal and below mean low water where the largest worms were located. Individual birds remained on the flat for a mean of 28.0 min and consumed a mean of 19.2 worms per visit. It was calculated that gulls remove a mean of 808 largeN. virens from the flat per tide from June to October, representing an estimated 0.04% of the standing crop of largeN. virens.
Central Pigmentary Sheen Dystrophy

Three members from two successive generations demonstrated a bilateral, symmetric pigmentary maculopathy consisting of a diffuse yellowish sheen of the posterior pole. The visual acuity was variable (20/25 to 10/400) and visual function tests indicated a localized disorder. Historic information suggests the disorder is slowly progressive. On the basis of mode of inheritance, fundus and angiographic appearance, and visual function testing this appears to be a newly described disorder.
EXPERIMENTAL STUDIES ON THE POSTNATAL DEVELOPMENT OF THE BRAIN. III. CEREBELLAR DEVELOPMENT FOLLOWING LOCALIZED ADMINISTRATION OF ENU

Experimental studies on the postnatal development of the train. III. Cere-bellar development following localized administration of ENU Microquantities of N-ethyl-N-nitrosourea (ENU) were injected directly into the cerebellum of 5 and 10 day old rats. It was found that ENU had cytotoxic effects not only on the mitotically active cells of the external granular layer, but also on the non-mitotic differentiating neurons, including Purkinje cells. Regeneration of the external granular layer, in part due to initial immigration of cells from the normal neighboring folia followed by mitosis, was found to be related to and followed by the recovery of the surviving Purkinje cells. These findings suggested that (a) disorientation and disorganization of the Purkinje cells were due to the treatment and not to the degenerative and regenerative activities of the external granular layer, and that (b) regeneration and increase in the external granular layer resulted from induction by the surviving Purkinje cells. Although microscopically the cerebellum appeared to have regenerated, macroscopically ENU had left lasting effects. The folia, where the carcinogen was injected, showed an absence of secondary folia, and the cerebellum as a whole was small in size.
Coarse-graining of proteins based on elastic network models

Abstract To simulate molecular processes on biologically relevant length- and timescales, coarse-grained (CG) models of biomolecular systems with tens to even hundreds of residues per CG site are required. One possible way to build such models is explored in this article: an elastic network model (ENM) is employed to define the CG variables. Free energy surfaces are approximated by Taylor series, with the coefficients found by force-matching. CG potentials are shown to undergo renormalization due to roughness of the energy landscape and smoothing of it under coarse-graining. In the case study of hen egg-white lysozyme, the entropy factor is shown to be of critical importance for maintaining the native structure, and a relationship between the proposed ENM-mode-based CG models and traditional CG-bead-based models is discussed. The proposed approach uncovers the renormalizable character of CG models and offers new opportunities for automated and computationally efficient studies of complex free energy surfaces.
Growth rates of n-knots☆

Abstract We use growth rates of group endomorphisms to define an invariant γ κ for any oriented spherical or disk n -knot K , provided its group has finitely generated commutator subgroup. In the special case of a fibered hyperbolic 1-knot K , γ κ is the log of the stretching factor of the pseudo-Anosov monodromy. We obtain results about satelite n -knots. We prove that there exist infinitely many distinct doubly slice fibered ribbon 1-knots having the same prescribed Alexander polynomial, and we give an example of a noninvertible fibered ribbon 2-knot that satisfies Ruberman's necessary conditions for a fibered even-dimensional knot to be invertible. Also, we present Miyazaki's argument that γ respects the partial ordering of ribbon concordance on the set of fibered 1-knots.
Compact reformulation of distorted-wave and coupled-channel Born approximations for transfer reactions between nuclei

Abstract DWBA and CCBA calculations are reformulated in a form which is compact, and which is symmetric with respect to the projected-ejectile system and to the target-residual nucleus system, so that the formulae can be used conveniently for heavy-ion as well as light-ion induced reactions. Clarification is also made of the relation between the exact finite-range calculations on the one hand and the no-recoil and zero-range approximations on the other. Some detailed information is given to show how to carry out efficiently the exact finite-range calculations.
A New Strategy for Spectroscopic Imaging

This paper describes a new approach for reducing ringing artifacts in spectroscopic imaging (or chemical-shift imaging). The new method is aimed at reducing the signal contamination in areas of interest, due to ringing, that often arises from adjacent areas with high intensity, such as subcutaneous fat in the case of 1H spectroscopy and skeletal muscle in case of the 31P spectroscopy. The method is based on the fact that the high-intensity signals which are the major source of contamination can be captured with one or few acquisitions and the metabolite resonances in areas of interest require considerably more averaging in the data acquisition due to low signal-to-noise ratio. In order to reduce ringing and maintain adequate SNR for the metabolites, the data points in high k space are measured with one or few excitations while those in the low k space are sampled with many excitations. By virtue of this sampling scheme, the data contain more noise in the high-spatial-frequency region and direct Fourier transformation reconstruction generates a very noisy image. Therefore, a new reconstruction technique is developed for the reconstruction. This approach has been studied by simulations and its practical utility is demonstrated by an in vivo proton CSI experiment. Technical details and simulation and experimental results are presented. From these results, it is concluded that the technique is robust and can be used for in vivo applications.
The anterior cerebral artery is an appropriate arterial input function for perfusion-CT processing in patients with acute stroke

Introduction Dynamic perfusion-CT (PCT) with deconvolution requires an arterial input function (AIF) for postprocessing. In clinical settings, the anterior cerebral artery (ACA) is often chosen for simplicity. The goals of this study were to determine how the AIF selection influences PCT results in acute stroke patients and whether the ACA is an appropriate default AIF.
Evolutionary music composer integrating formal grammar

In this paper, an autonomous music composition tool is developed using Genetic Algorithms. The production is enhanced by integrating formal grammar rules. A formal grammar is a collection of either or both descriptive or prescriptive rules for analyzing or generating sequences of symbols. In music, these symbols are musical parameters such as notes and their attributes. The composition is conducted in two Stages. The first Stage generates and identifies musically sound patterns (motifs). In the second Stage, methods to combine different generated motifs and their transpositions are applied. These combinations are evaluated and as a result, musically fit phrases are generated. Four musical phrases are generated at the end of each program run. The generated music pieces will be translated into Guido Music Notation (GMN) and have alternate representation in Musical Instrument Digital Interface (MIDI). The Autonomous Evolutionary Music Composer (AEMC) was able to create interesting pieces of music that were both innovative and musically sound.
Residual strength prediction of damaged composite fuselage panel with R-curve method

Abstract This study applies the crack growth resistance curve (R-curve) method to predict the residual strength of a composite fuselage panel with discrete source damage. The R-curve is constructed from the energy release rates computed from cracked tensile plate test specimens at their failure loads. To predict the residual strength of a curved fuselage panel with discrete source damage using the R-curve method, G-curves of the energy release rate of the damaged fuselage panel need to be established. These G-curves are generated for various fuselage pressures over a range of crack lengths. Since this study found that the membrane stiffening effect could significantly reduce the energy release rate at the crack tip of a pressurized fuselage, geometrically nonlinear behavior was considered in the calculations. The residual strength of the damaged fuselage panel was determined by comparing the energy release rates with the “allowable-like” R-curve. The correlation between the crack growth predictions and the damage progression results obtained from experiments is very good. Therefore, the R-curve method has the potential to be a practical engineering method for predicting the residual strength of damaged fuselage panels.
A class of throughput optimal routing policies

This paper considers the problem of routing packets across a multi-hop wireless network while ensuring throughput optimality. One of the main challenges in the design of throughput optimal routing policies is identifying an appropriate Lyapunov function with negative expected drift. The only known throughput optimal routing policies in the literature, most notably backpressure routing, are constructed using simple node-based quadratic or exponential Lyapunov functions of the queue backlogs and as such exhibit poor delay performance under many network topologies and traffic conditions. By constructing a class of continuous, differentiable, and piece-wise quadratic Lyapunov functions, this paper provides a large class of throughput optimal routing policies. The nature of the proposed Lyapunov functions is such that, under a “sufficiently unbalanced” backlog state, the traffic must be routed away from nodes with significantly large backlogs (consistent with backpressure) in order to ensure a negative expected drift. In contrast, under all other backlog states, any non-idling policy can ensure a negative expected drift in the proposed Lyapunov function, providing tremendous flexibility in controlling routing decisions for most of the state-space.
Sustainable Leadership and Development in Education: creating the future, conserving the past

This article addresses how to reconcile the creative and innovative emphases of future knowledge societies with the needs and demands for longer term sustainable development of enduring and worthwhile practices — within education and beyond it. Drawing on a theoretical framework of organisational memory and sustainability, the article argues that most change efforts deny or demean the past in an attempt to promise a better future, and need instead to build improvement efforts in ways that connect their future and their past.
Seeing collectivity: Structural relation through the lens of Youngian seriality

This article is an examination of the puzzle of why there has been so little organizing of the unemployed and the precariously employed in the years since the beginning of the Great Recession in 2008. I argue that this paucity of organization is, in part, the result of the sedimentation of a neoliberal commonsense, or a particularly dominant colloquial interpretation of American individualism, which makes it difficult to perceive structural relation – not only in the case of economic politics, but generally speaking. I propose that using Youngian seriality as a lens can help us see structural relation more lucidly without reducing all structural relation to class relations or making essentialist claims about who we may be as persons or about the objective nature or static organization of structures themselves. This way of seeing provides an opportunity to perceive the multifaceted and intersectional ‘we’s’ that contemporary people perceive themselves to be, while not reducing the individual to an atomistic being outside the context of social, political and economic relations.
Nickel Oxide Interstratified α-Zirconium Phosphate, a Composite Exhibiting Ferromagnetic Behavior

As part of an ongoing research program to synthesize novel pillared layered materials, nickel and cobalt hydroxyacetates were inserted between the layers of amine intercalates of α-zirconium phosphate. The structure of the resultant nickel composite, derived from x-ray powder data, was found to consist of a three-tiered layer of nickel atoms bridged by hydroxo and acetato groups. Heating to 420°C converted the hydroxyacetate layers to oxide and imparted ordered magnetic domains to the composite. The phosphate layers appear to act as a template directing the growth of the inserted layers in this class of composite materials.
In vitro models to evaluate acute and chronic injury to the heart and vascular systems.

Abstract Multiple in vitro model systems are currently available to evaluate structure and function relationships in the cardiovascular system as well as the system’s response to injury. As the level of molecular sophistication continues to advance, so does the level of complexity of the analysis. One of the most daunting tasks faced by researchers interested in studying cardiovascular function and injury is the selection of the system or systems best suited to answer the particular question at hand. In order to successfully apply any given model system, the researcher must recognize the advantages and limitations in the system of choice. This review provides a listing of the historical and modern techniques used to study cardiovascular function and chemically-induced toxicity. With the growing number of new pharmaceuticals discovered each year, it is imperative to use experimental model systems that allow for identification of targets that participate in or mediate adverse outcomes. Clearly, in vitro analysis cannot replace in vivo experimentation, but the methods currently available allow for a reduction in the number of animals used for experimentation and a better understanding of the complexity associated with the injury response.
Elastic scattering of electrons from SO2

Using a crossed electron beam–molecular beam scattering geometry and the relative‐flow technique, ratios of elastic differential cross sections of SO2 to those of He have been measured at electron impact energies of 12, 20, 50, 100, 150, and 200 eV. At each energy, an angular range of 15° to 150° has been covered. These ratios have been multiplied by previously known He elastic differential cross sections to obtain elastic differential cross sections for SO2. From a knowledge of differential cross sections, integral and momentum transfer cross sections have been determined. Using the two‐potential theory of e‐molecule scattering, calculations were also performed and compared with the measurements.
An asynchronous data acquisition ASIC with a data-push architecture

Abstract We report on a digital circuit for data acquisition that has been developed for high energy physics applications. Its function is to receive asynchronous voltage pulses, time-stamp them individually and transmit them sequentially on an external bus. A 16-channel design has been fabricated as an application specific integrated circuit (ASIC) using the HP 1.2 μm double-metal, single-polysilicon process. Test results made on prototype chips indicate that the circuit performs within specifications for an operating clock frequency of 25 MHz and a working environment temperature of 0°C to 40°C.
Design of multifocal transmitarray antennas for beamforming applications

Beam scanning performance of planar multifocal transmitarray antennas are investigated in this paper. The advantages of the proposed structure over conventional designs are first delineated, and then a Ku-band transmitarray antenna with quadrufocal phase distribution is designed using the particle swarm optimization technique for 60° scan coverage, which shows a good performance. The results presented in this study reveal that multifocal transmitarray antenna can be a suitable low-cost choice for high-gain beamforming applications.
Prenatal benzodiazepine administration. II. Lorazepam exposure is associated with decreases in [35S]TBPS binding but not benzodiazepine binding.

Abstract Prenatal benzodiazepine exposure has been associated with neurobehavioral alterations in humans and animals. To determine effects of prenatal benzodiazepine exposure on binding at the benzodiazepine and t-butylbicyclophosphorothionate (TBPS) sites on the GABA A receptor in mature offspring, we treated mice with lorazepam, 2 mg/kg/day, during days 13–20 of gestation. Binding was assessed at 6 weeks of age. There were no differences among controls, vehicle- or lorazepam-exposed mice in benzodiazepine receptor binding determined in vivo or in vitro. However, receptor density for [ 35 S]TBPS binding sites was decreased in lorazepam-exposed offspring compared to the other groups. These data are consistent with prior neurochemical results indicating decreased TBPS binding and GABA A receptor function in several systems.
Performance and environment monitoring for continuous program optimization

Our research is aimed at characterizing, understanding, and exploiting the interactions between hardware and software to improve system performance. We have developed a paradigm for continuous program optimization (CPO) that assists in and automates the challenging task of pelformance tuning, and we have implemented an initial prototype of this paradigm. At the core of our implementation is a performance- and environment-monitoring (PEM) component that vertically integrates performance events from various layers in the execution stack. CPO agents use the data provided by PEM to detect, diagnose, and alleviate performance problems on existing systems. In addition, CPO can be used to improve future architecture designs by analyzing PEM data collected on a whole-system simulator while varying architectural characteristics. In this paper, we present the CPO paradigm, describe an initial implementation that includes PEM as a component, and discuss two CPO clients.
Double Negative (CD3+4-8-) TCRαβ Splenic Cells from Young NOD Mice Provide Long-Lasting Protection against Type 1 Diabetes

BACKGROUND Double negative CD3(+)4(-)8(-) TCR alphabeta splenic cells (DNCD3) can suppress the immune responses to allo and xenografts, infectious agents, tumors, and some autoimmune disorders. However, little is known about their role in autoimmune diabetes, a disease characterized by the reduction of insulin production subsequent to destruction of pancreatic beta-cells by a polyclonal population of self-reactive T-cells. Herein, we analyzed the function and phenotype of DNCD3 splenic cells in young NOD mice predisposed to several autoimmune disorders among which, the human-like autoimmune diabetes. METHODOLOGY/PRINCIPAL FINDINGS DNCD3 splenic cells from young NOD mice (1) provided long-lasting protection against diabetes transfer in NOD/Scid immunodeficient mice, (2) proliferated and differentiated in the spleen and pancreas of NOD/Scid mice and pre-diabetic NOD mice into IL-10-secreting T(R)-1 like cells in a Th2-like environment, and (3) their anti-diabetogenic phenotype is CD3(+)(CD4(-)CD8(-))CD28(+)CD69(+)CD25(low) Foxp3(-) iCTLA-4(-)TCR alphabeta(+) with a predominant Vbeta13 gene usage. CONCLUSIONS/SIGNIFICANCE These findings delineate a new T regulatory component in autoimmune diabetes apart from that of NKT and CD4(+)CD25(high) Foxp3(+)T-regulatory cells. DNCD3 splenic cells could be potentially manipulated towards the development of autologous cell therapies in autoimmune diabetes.
On the positivity of the Bondi mass

Abstract A new way of showing local positivity of the Bondi mass is presented. The method used makes use only of the constraint equations. By looking at the constraint equations of general relativity on an asymptotically constant mean extrisic curvature hypersurface, a mass aspect is picked out, whose average over the 2-sphere coincides with the Bondi mass. This mass aspect differs from Bondi's mass aspect by terms linear in the news function. It is shown that the mass aspect so produced may be considered as a functional of the dependent data in the problem. This functional is shown to have Minkowski space as a critical point. The second variational of the functional about flat space is then shown to be positive. From this, one concludes that the functional is positive in a neighborhood of flat space. Hence the Bondi mass, too, is positive in a neighborhood of flat space.
The influence of sodium on the calcium nutrition of excised cotton roots

Growth of excised cotton roots increased with increasing substrate Ca from 0.025 to 0.8 mM, although in most cases no significant increase was obtained above 0.2 mM. The sodium effect was more complex and indicated that there were two positive relationships between the Na level and root elongation.
Methods of Estimating the Input Coefficients for Linear Programming Models

In order to apply the linear programming method to determine the most profitable product mix of a farm, it is often necessary to estimate the input coefficients from sample data. The estimated coefficients must all be nonnegative. Estimates from regression models of input demand equations are not always nonnegative. The sample average of inputs used per acre of various crops provides nonnegative estimates but may suffer from selectivity bias. In this study the methods of minimizing the mean of absolute deviations and of minimizing the maximum absolute deviation are discussed as alternatives to inequality-constrained least squares.
Histology of abortive egg sites in the uterus of a viviparous, placentotrophic lizard, the skink Chalcides chalcides

Although abortive uterine eggs are often assumed to be resorbed by females of the viviparous skink Chalcides chalcides, little microscopic evidence of resorption of such eggs is available. Oviducts from pregnant female C. chalcides in which egg resorption was inferred were examined histologically to seek a morphological basis for resorption. Uterine histology at the site of abortive eggs was very similar to that of lizards in early pregnancy. The uterine epithelium consisted of a monolayer of pseudostratifed columnar cells that showed no evidence of yolk phagocytosis. The uterine lamina propria exhibited shell glands and modest vascularity, typical of early gestation, and contained neither yolk droplets nor accumulating leukocytes. Unattenuated regions of the lamina propria contained occasional macrophages and mast cells, some of the latter of which were undergoing degranulation. The abortive eggs often were collapsed with ruptured shell membranes, and some were undergoing extrusion from the incubation chambers down the oviduct. In eggs that had begun developing, extraembryonic ectoderm and endoderm were atypical in location, and had failed to enclose yolk leaking from the eggs. Oviducts sampled from later in the reproductive season were reproductively inactive, and showed no trace of abortive eggs or egg components. We postulate that abortive eggs are extruded from the oviduct by pregnant females under conditions of physiological stress, as a means of enhancing future reproductive effort. J. Morphol. 235:97-108, 1998. © 1998 Wiley-Liss, Inc.
Introduction: Mentholated cigarettes and public health.

The Food and Drug Administration’s Center for Tobacco Products (CTP) oversees the implementation of the Family Smoking Prevention and Tobacco Control Act, H.R. 1256. Among its many provisions, section 907(a) of the Tobacco Control Act banned the use of characterizing flavors, specifically excluding only tobacco and menthol flavors from the ban. According to section 907(e)(2), “[n]ot later than 1 year after its establishment, the Tobacco Product Scientific Advisory Committee shall submit to the Secretary the report and recommendations required pursuant to [menthol],” which, according to section 907(e)(1), is “the issue of the impact of the use of menthol in cigarettes on the public health, including such use among children, African-Americans, Hispanics, and other racial and ethnic minorities.” The inaugural meeting of the Food and Drug Administration’s Tobacco Products Scientific Advisory Committee (TPSAC) was held March 30–31, 2010 in Washington, DC. In preparation for this meeting, CTP reviewed peer-reviewed literature on menthol and tobacco as indentified by the National Cancer Institute’s “Bibliography of literature on menthol and tobacco”, and seven scientific presentations were made, including the use of menthol cigarettes (epidemiology), smoking topography and sensations associated with menthol cigarettes, marketing of menthol cigarettes, menthol cigarettes and initiation of smoking behavior, menthol cigarettes and nicotine dependence, menthol cigarettes and cessation of tobacco use, and the health effects of menthol cigarettes as compared to non-menthol cigarettes. Following this initial presentation, additional information was collected through FDA investigation, as well as recommendations from the public, research community and tobacco industry, resulting in comprehensive reviews. Thus, this supplement brings together the extant peer-reviewed information on these seven topics.
Industrial Innovation in Japan and the United States

Japanese firms tend to be quicker and more economical than U.S.firms at developing and introducing new products and processes, but this advantage seems to exist only among innovations based on external technology, rather than internal technology. Whereas U.S.firms put more emphasis on marketing start-up, they put much less emphasis on tooling, equipment, and manufacturing facilities than do Japanese firms. Applied RD but there is no evidence that the rate of return from basic research has been relatively high in Japan. In robotics, the Japanese edge seems to increase as one moves from R&D toward the market.
Multinuclear NMR and infrared spectroscopic study of a series of cis‐Mo(CO)4(py‐R)2 (Py‐R = 3‐ or 4‐substituted pyridine) complexes: Relationship between chemical shifts and infrared force constants and the Taft electron donor/acceptor parameters of the pyridine substituents

Poor correlations are normally observed between the chemical shifts of the various NMR-active nuclei in Mo carbonyl complexes of group 15 ligands as the group 15 atom substituents are varied. It is possible to observe good chemical shift correlations and to develop relationships between chemical shift and changes in electron density due to variations in the group 15 atom substituents, provided that this variation does not change the cone angles of these ligands. This is the case for complexes of the type cis-Mo(CO)4(py-R)2 (py-R = 3- or 4-substituted pyridine). Good to excellent linear correlations are observed between the chemical shifts of the cis and trans CO 13C and 17O resonances and the 95Mo resonances in these complexes, and between these chemical shifts and the CO infrared stretching force constants of the complexes. Good to excellent correlations also occur between either the chemical shifts or the CO infrared stretching force constants and either the Taft σm/σp or σR and σ1 parameters. These correlations provide significant insights into the relationship between the electron donor/acceptor abilities of the pyridine ligands and the NMR and infrared spectra exhibited by the cis-Mo(CO)4(py-R)2 complexes.
Distortion product otoacoustic emission suppression tuning curves in human adults and neonates

Distortion product otoacoustic emission (DPOAE) iso-suppression tuning curves (STC) were generated in 15 normal-hearing adults and 16 healthy term-born neonates for three f2 frequencies. The 2f1-f2 DPOAE was elicited using f2/f1 = 1.2, LI = 1.2, LI = 65 and L2 = 50 dB SPL. A suppressor tone was presented at frequencies ranging from 1 octave below to 1/4 octave above f2 and varied in level until DPOAE amplitude was reduced by 6 dB. The suppressor level required for 6 dB suppression was plotted as function of suppressor frequency to generate a DPOAE STC. Forward-masked psychoacoustic tuning curves (PTC) were obtained for three of the adult subjects. Results indicate that DPOAE STCs are stable and show minimal inter- and intra-subject variability. The tip of the STC is consistently centered around the f2 region and STCs are similar in shape, width (Q10) and slope to VIIIth-nerve TCs. PTCs and STCs measured in the same subject showed similar trends, although PTCs had narrower width and steeper slope. Neonatal STCs were recorded at 3000 and 6000 Hz only and were comparable in shape, width and slope to adult STCs. Results suggest: (1) suppression of the 2f1-f2 DPOAE may provide an indirect measure of cochlear frequency resolution in humans and (2) cochlear tuning, and associated active processes in the cochlea, are mature by term birth for at least mid- and high-frequencies. These results provide significant impetus for continued study of DPOAE suppression as a means of evaluating cochlear frequency resolution in humans.
The bioenergetics of methanogenesis.

The reduction of CO2 or any other methanogenic substrate to methane serves the same function as the reduction of oxygen, nitrate or sulfate to more reduced products. These exergonic reactions are coupled to the production of usable energy generated through a charge separation and a protonmotive-force-driven ATPase. For the understanding of how methanogens derive energy from C-1 unit reduction one must study the biochemistry of the chemical reactions involved and how these are coupled to the production of a charge separation and subsequent electron transport phosphorylation. Data on methanogenesis by a variety of organisms indicates ubiquitous use of CH3-S-CoM as the final electron acceptor in the production of methane through the methyl CoM reductase and of 5-deazaflavin as a primary source of reducing equivalents. Three known enzymes serve as catalysts in the production of reduced 5-deazaflavin: hydrogenase, formate dehydrogenase and CO dehydrogenase. All three are potential candidates for proton pumps. In the organisms that must oxidize some of their substrate to obtain electrons for the reduction of another portion of the substrate to methane (e.g., those using formate, methanol or acetate), the latter two enzymes may operate in the oxidizing direction. CO2 is the most frequent substrate for methanogenesis but is the only substrate that obligately requires the presence of H2 and hydrogenase. Growth on methanol requires a B12-containing methanol-CoM methyl transferase and does not necessarily need any other methanogenic enzymes besides the methyl-CoM reductase system when hydrogenase is present. When bacteria grow on methanol alone it is not yet clear if they get their reducing equivalents from a reversal of methanogenic enzymes, thus oxidizing methyl groups to CO2. An alternative (since these and acetate-catabolizing methanogens possess cytochrome b) is electron transport and possible proton pumping via a cytochrome-containing electron transport chain. Several of the actual components of the methanogenic pathway from CO2 have been characterized. Methanofuran is apparently the first carbon-carrying cofactor in the pathway, forming carboxy-methanofuran. Formyl-FAF or formyl-methanopterin (YFC, a very rapidly labelled compound during 14C pulse labeling) has been implicated as an obligate intermediate in methanogenesis, since methanopterin or FAF is an essential component of the carbon dioxide reducing factor in dialyzed extract methanogenesis. FAF also carries the carbon at the methylene and methyl oxidation levels.(ABSTRACT TRUNCATED AT 400 WORDS)
Isolation of a Vicia faba metallothionein-like gene: expression in foliar trichomes

Animal metallothioneins (MTs) are cysteine-rich, low-molecular-weight proteins that bind to heavy metals and are believed to play a role in their metabolism and detoxification. Genes encoding MT-like proteins have been isolated in a number of plants although their function remains to be elucidated. We describe the isolation and characterization of a bean cDNA encoding an MT-like protein. The bean gene, called MT, was isolated as a result of a differential screen for genes that are expressed in leaves but not in the most common cell type, the mesophyll cell. MT contained two regions with abundant cysteines and sequence comparison found that MT had greatest homology to MT-like subtype 2 from other plant species. Northern blot analysis demonstrated that MT was expressed in the leaf, stem and flower, at very low levels in roots and was not detectable in mesophyll protoplasts. MT transcript levels were not significantly affected by treatment with Cu, Zn or Cd. In the leaf, in situ hybridization studies demonstrated striking cell specificity with MT expression confined predominantly to trichomes. Possible explanations for the pronounced expression of MT in leaf trichomes are discussed.
The septum in the human brain

The septum of the human brain was studied in relation to its location, composition and development. It was possible to divide it into two parts: septum pellucidum, composed of fiber tracts and glia, and septum verum (true septum) which in addition to fiber tracts and glia, contain neurons arranged in a nuclear pattern. The septum verum in the human corresponds to the septum as described in lower forms. The human septum has been thought to have regressed and be nearly functionless in contrast to lower forms. However, the nucleus septalis triangularis is the only septal nucleus which regressed in development when compared to that in the brains of insectivores and primates. The rest of the septal nuclei progressively increased in size during primate development. Finally, it should be emphasized that the septum verum of the human has attained its highest degree of development in primate phylogeny.
The local median and other window operations on SIMD computers

Abstract Local window operations are frequently used to filter data in image processing applications. In this paper the implementation of several local operations on an SIMD computing structure is considered. These operations are: local median, local maximum, local mean, and local sorting. Efficient implementation is achieved by factoring the operation such that partial results may contribute to more than one local computation. The cost of these operations in terms of computation, storage and routing on a mesh connected processor is discussed.
Growth of postembryonic skin epithelial cells on collagen gels.

A procedure to extract and to purify acid-soluble collagen from rabbit skin and a technique to prepare a semi-transparent collagen gel to support growth of postembryonic rabbit, mouse, and human skin epithelial cells are presented. When a suspension of trypsin-released epithelial cells is plated on a collagen gel, the reorganization and growth of cells takes place in 3 stages. In stage 1, the germinative cells attach to, and assume a polyhydral configuration on the surface of the gel. In Stage 2, the cells migrate actively over the surface of the gel and reassociate into a multicellular colony. In Stage 3, the cells both multiply horizontally and vertically to the surface of the gel. A quantitative method to study growth and metabolism of isolated epidermal cells and the factors which induce or repress epidermal growth in vitro are outlined.
Comparison of the 197Au (ϱ, fission) to the 194Pt (α, fission) at an excitation of 40·5 MeV

Abstract Through the use of standard radiochemical techniques, the charged particle induced fission of 198Hg was studied by the formation of this species by means of protons on 197Au and helium ions on 194Pt to yield the compound nucleus in the same excitation level. At the 40·5 MeV excitation the two fission reactions produced nearly identical fission fragment mass distribution curves with a width at half maximum ( W 1 2 ) of 21 ± 1 a.m.u. However, the proton induced fission cross-section was 140 μbarns and the helium ion-induced fission was only 22 μbarns. It is postulated that this effect may be due to the relative deposition of angular momentum into each target nucleus resulting in a partition of excitation energy into vibrational and rotational states which is different in each case, resulting in different probabilities for fission due to the different mode of compound nucleus formation.
The effect of age and lung pathology on cytochrome a,a3 redox levels in rat cerebral cortex.

Abstract The steady-state reduction/oxidation (redox) ratio of cytochrome a,a3 in the non-stressed or ‘resting’ cerebral cortex was compared in ‘healthy’ mature and aged rats and in animals with varying degress of lung pathology present. By using non-invasive dual wavelength spectrophotometry, cytochrome a,a3 was found to be approximately 30% reduced under ‘resting’ conditions in both mature and ‘aged’ brain. Although no significant age-related or strain differences were apparent, the ‘resting’ redox level of cytochrome a,a3 was markedly affected by the presence of lung pathology. The redox ratio was lower in animals where lung lesion involvement was not extensive, and higher (indicative of cellular hypoxia) in animals having both extensive acute and chronic lung pathology. These studies demonstrate that, regardless of age or lung pathology, the cortical cytochrome a,a3 redox state is labile to changes in the amount of inspired oxygen, a condition differing from that of isolated mitochondria. These results indicate that dysfunction of the mitochondrial respiratory chain is not a direct or primary consequence of chronological aging in the ‘resting’ brain.
Race/ethnicity, socioeconomic factors, and smoking among early adolescent girls in the United States.

Abstract Background This study uses large nationally representative samples of White, Black, Mexican American, Puerto Rican, Other Latina, Asian American, and American Indian 8th-grade girls to examine racial/ethnic differences and similarities in patterns, trends, and socioeconomic correlates of cigarette use. Methods The data are drawn from the University of Michigan's Monitoring the Future study. Prevalence and trend data (from 1991 to 2007) in girls’ cigarette use were examined by racial/ethnic subgroup. Logistic regression analyses were conducted to determine the extent to which socioeconomic factors predict girls’ cigarette use, and whether the relationships between socioeconomic status (SES) and smoking differed across racial/ethnic subgroup. Results Cigarette use was highest among American Indian girls; at an intermediate level among Mexican American, Puerto Rican, Other Latinas, and White girls; and lowest among Black and Asian American girls. Trend data show that cigarette use has declined for all racial/ethnic subgroups, and that small but consistent racial/ethnic differences in girls’ cigarette use have persisted. Generally, girls who did not live in two-parent households, whose parents had lower levels of educational attainment, who attended lower SES schools, and who had more disposable income were more likely than their peers to smoke. That said, however, the relationships between smoking and parental education and school SES were, on average, stronger for White girls than for Black or Hispanic (Mexican American, Other Latina, Puerto Rican) girls. Conclusions Future research should seek to understand the mechanisms by which low SES impacts smoking.
A Study of Frontogenesis Using Finite-Element and Finite-Difference Methods

Abstract The accuracy of finite-element and finite-difference methods used to simulate frontogenesis in a six-layer three-dimensional model employing isentropic coordinates is compared. The problem solved is that of an initial height-independent deformation velocity field with a small potential temperature perturbation. The problem has a two-dimensional analytical solution and thus the accuracy of each model is assessed with the aid of this known solution. The finite-element model required approximately half the computer time needed for the finite-difference solution. In addition, due to the strong internal coupling between elements, the finite-element method is better able to simulate the open boundary Neumann conditions which are required for the present problem. This internal coupling, together with the smoothing action of operating on an element of space rather than a point as in finite differences, provides the stibility the finite-element technique shows in this example. Both solution methods give s...
Inquiry Training in the School's Science Laboratories*

Inquiry training and critical thinking, as goals of science education in secondary schools, have long been held as goals worth achieving. But, like the weather, they have been more talked-about than doneabout! Part of this stems from the fact that teachers who like to teach also like to talk. Floyd (1960) indicates with primary teachers that about 95% of all talking is done during class by the teacher. It is probable that this is equalled in secondary school classrooms. Suchman^s work (1962) rather leads the present writer to believe that, by Grade 3, children no longer ask the questions to which they want to know the answers, but find it advantageous from the standpoint of good grades to ask questions to which the teacher knows the answer; Suchman^s finding that several weeks of individual work with children to learn again how to ask crucial questions to find answers that they want to know, when these children reach Grade 6, makes one wonder if the usual junior and senior high school student without such training ever does learn (or should I say re-learn) the skill he had so well at Grade 1 level. Questioning is at the basis of inquiry, whether it is Inquiry as Content or Inquiry as Technique. Certainly, much can be gained from organizing content, step by step, so that the student sees the crucial experiments which, with Platt^s ^strong inference55 (1964) have led to our present state of knowledge. But today we are more concerned with that facet of Inquiry as Technique by which, with the proper organization of laboratory experiences, the student actually learns (though it be slow and laborious) the ways of the scientist in inquiry process. This means learning how to inquire by actually doing his sciencing in the laboratory as inquiry. Beginning at puberty, the Basal Metabolic Rate drops from that of early childhood to that of normal adults, and as Piaget has shown in many of his 48 books, with this change comes a shift from concrete operations to the newly discovered logical operations of adulthood. One is tempted to believe that only at lower metabolic rates do those synaptic electrochemical conditions exist which permit logical inference. Whatever the physiological chemistry involved, the secondary school science teacher can capitalize on the condition whereby students suddenly want to know ^why77 as well as "how.75 This is the
A surface chemical potential for elastic solids

Abstract The surface chemical potential field represents the tendency for an elastic solid to lower its free energy by means of mass rearrangement. In a recent paper in this Journal, Wu, 1996 [ J. Mech. Phys. Solids 44, 2059–2077] pointed out that the commonly used definition of chemical potential for elastic solids is inconsistent with the change in free energy of the system associated with shape change at finite strain. The purpose here is to rederive Wus main result by a direct rate calculation, rather than a variational approach, which appears to be simpler in implementation. In addition, the definition is generalized to include orientation dependence of surface energy.