cssi/SciSciGPT-SciSciNet huggingface dataset:
Use of a Fluorescent Analogue of 2,3-Diphosphoglycerate as a Probe of Human Hemoglobin Conformation during Carbon Monoxide Binding

Abstract The interaction of human hemoglobin (Hb) with 8-hydroxy-1,3,6-pyrenetrisulfonate (HPT) was studied at pH 6.0 and T/2 = 0.04. Binding of HPT was determined by quenching of its fluorescence upon interaction with Hb. HPT binds to deoxy-Hb with a stoichiometry of 1 mole per mole of Hb tetramer and with a higher affinity for the deoxy than the liganded form analogous to the binding of the physiologically important 2,3-diphosphoglycerate (DPG). Binding is prevented by either DPG or inositol hexaphosphate. A qualitative comparison of the time courses of HPT release and CO combination during the reaction of CO with deoxy-Hb indicates a marked lag in the release of HPT compared with CO binding. This led to the conclusion that during the course of CO binding, significant amounts of partially liganded Hb intermediates are formed and the release of HPT from the intermediates does not occur in proportion to the amount of CO bound. Quantitative analysis of the data, in the form of least squares fitting procedures, was carried out to examine the ability of some elementary models to describe the results. The best fit was obtained on the assumption that HPT is released after 3 CO molecules have bound to hemoglobin.
The Spins of Cyons and Dyons

It has recently been suggested1that a new kind of atom, sometimes called a cyon, may be able to have any spin and presumably any, or at least unusual, statistics. A cyon consists of a charged particle (e) which in the simplest case is a spinless boson bound by a scalar force to a toroidal region surrounding a magnetic flux line that lies along the z axis (Fig. 1) and carries an amount of flux equal to Φ.
Effects of perfusion on diffusion changes in human brain tumors.

Purpose To characterize the influence of perfusion on the measurement of diffusion changes over time when ADC is computed using standard two-point methods. Materials and Methods Functional diffusion maps (FDMs), which depict changes in diffusion over time, were compared with rCBV changes in patients with brain tumors. The FDMs were created by coregistering and subtracting ADC maps from two time points and categorizing voxels where ADC significantly increased (iADC), decreased (dADC), or did not change (ncADC). Traditional FDMs (tFDMs) were computed using b = 0,1000 s/mm2. Flow-compensated FDMs (fcFDMs) were calculated using b = 500,1000 s/mm2. Perfusion's influence on FDMs was determined by evaluating changes in rCBV in areas where the ADC change significantly differed between the two FDMs. Results The mean ΔrCBV in voxels that changed from iADC (dADC) on the tFDM to ncADC on the fcFDM was significantly greater (less) than zero. In addition, mean ΔrCBV in iADC (dADC) voxels on the tFDM was significantly higher (lower) than in iADC (dADC) voxels on the fcFDM. Conclusion The ability to accurately identify changes in diffusion on traditional FDMs is confounded in areas where perfusion and diffusion changes are colocalized. Flow-compensated FDMs, which use only non-zero b-values, should therefore be the standard approach. J. Magn. Reson. Imaging 2013;38:868–875. © 2013 Wiley Periodicals, Inc.
Early Micro Vascular Changes After Subarachnoid Hemorrhage

During the last decade much effort has been invested in understanding the events that occur early after SAH. It is now widely accepted that these early events not only participate in the early ischemic injury but also set the stage for the pathogenesis of delayed vasospasm. That early cerebral ischemia occurs after SAH is documented in both experimental SAH and in human autopsy studies; however, angiographic evidence for vasoconstriction early after SAH is lacking and the source of early ischemic injury is therefore unclear. Recently, the cerebral microvasculature has been identified as an early target of SAH. Changes in the anatomical structure of cerebral microvessels, sufficient to cause functional deficits, are found early after experimental SAH. These changes may explain cerebral ischemia in human in the absence of angiographic evidence of large vessel vasoconstriction. This paper summarizes known alterations in cerebral microvasculature during the first 48h after SAH.
The Contribution of Cell Surface Components to the Neutrophil Mechanosensitivity to Shear Stresses

This review discusses the regulation of neutrophils by fluid shear stress in the context of factors that may govern cell mechanosensitivity and its influence on cell functions. There is substantial evidence that mechanoreceptors located on the peripheral membrane contribute to the ability of shear stress to regulate cell activity. In the case of neutrophils, the formyl peptide receptor (FPR) and the CD18 integrins on the cell membrane have been shown to provide neutrophils with the ability to sense shear stresses in their local environment and alter their physiological state, accordingly. This configuration is also found for other types of cells, although they involve different cell-specific mechanoreceptors. Moreover, from an examination of the neutrophil mechanotransducing capacity, it is apparent that cellular mechanosensitivity depends on a number of factors that, if altered, contribute to dysregulation and ultimately pathophysiology. To exemplify this, we first describe the neutrophil responses to shear exposure. We then review two neutrophil mechanoreceptors, specifically FPR and CD18 integrins, which participate in controlling cell activity levels under physiological conditions. Next, we discuss the various factors that may alter neutrophil mechanosensitivity to shear stress and how these may underlie the circulatory pathobiology of two cardiovascular disease states: hypertension and hypercholesterolemia. Based on the material presented, it is conceivable that cell mechanosensitivity is a powerful global metric that permits a more efficient approach to understanding the contribution of mechanobiology to physiology and to disease processes.
On the Minimum Description Length Complexity of Multinomial Processing Tree Models.

Multinomial processing tree (MPT) modeling is a statistical methodology that has been widely and successfully applied for measuring hypothesized latent cognitive processes in selected experimental paradigms. This paper concerns model complexity of MPT models. Complexity is a key and necessary concept to consider in the evaluation and selection of quantitative models. A complex model with many parameters often overfits data beyond and above the underlying regularities, and therefore, should be appropriately penalized. It has been well established and demonstrated in multiple studies that in addition to the number of parameters, a model’s functional form, which refers to the way by which parameters are combined in the model equation, can also have significant effects on complexity. Given that MPT models vary greatly in their functional forms (tree structures and parameter/category assignments), it would be of interest to evaluate their effects on complexity. Addressing this issue from the minimum description length (MDL) viewpoint, we prove a series of propositions concerning various ways in which functional form contributes to the complexity of MPT models. Computational issues of complexity are also discussed.
Reaction of Selected Soybean Genotypes to Isolates of Fusarium solani f. sp. glycines and Their Culture Filtrates

Four soybean plant introductions, PI 520.733, PI 567.374, PI 567.650B, and PI 567.659, and one soybean cultivar, Great Lakes 3202, were inoculated under greenhouse conditions with four isolates of Fusarium solani f. sp. glycines. Foliar disease severity rating was greatest on PI 567.659, followed by Great Lakes 3202, PI 520.733, PI 567.650B, and PI 567.374. There was no significant interaction between isolates and soybean entries for foliar disease severity ratings. Experiments also were conducted to determine if disease development and root colonization differed among entries. Root infection of the five entries did not differ (P = 0.05). Foliar disease progress curves increased faster for PI 567.659 and Great Lakes 3202 than for PI 567.374. The area under the disease progress curve (AUDPC) value for PI 567.374 was the lowest and differed (P = 0.01) from AUDPC values for Great Lakes 3202 and PI 567.659. There were no differences (P = 0.01) in length of taproot lesions, losses in root dry weight, and vascular stem length discoloration among the entries, and there was no correlation (P = 0.05) between these measurements and foliar AUDPC values. Cut seedling stems immersed in culture filtrate developed interveinal chlorosis on leaves of each entry within 2 days. Disease severity on cut seedlings of PI 567.374 was lower (P = 0.01) than on the other entries. There was a positive correlation (r = 0.94, P = 0.05) between AUDPC values of the five entries inoculated with the fungus and the cut seedling test using culture filtrate.
Intermyofibrillar and nuclear-myofibrillar connections in human and canine myocardium. An ultrastructural study.

Abstract Cytoplasmic filaments, which measure 100 A in diameter, and which differ morphologically from actin and myosin filaments, are described in normal canine myocardium and in normal and hypertrophied human myocardium. These filaments were found between Z bands, near the sarcolemma, in regions of intercalated discs, and in the vicinity of nuclear membranes. The 100 A filaments appeared to form transverse connections between adjacent Z bands and between Z bands and outer nuclear membranes. These filaments probably function as a cytoskeleton.
The interaction of porphyrin precursors with GABA receptors in the isolated frog spinal cord.

Abstract Both delta aminolevulinic acid (ALA) and porphobilinogen (PBG) depressed spontaneous activity in the isolated hemisected frog spinal cord. ALA was approximately one fifth as potent as GABA in this respect and had a much slower time course. ALA hyperpolarized motoneurones and this effect was blocked by the GABA antagonist, picrotoxin, but not by the glycine antagonist, strychnine. ALA also depolarized primary afferents and this effect was similar to that of GABA although its action was somewhat reduced by strychnine. These results suggest that ALA activates the GABA receptors on motoneurones and primary afferents. The possible significance of these results to the clinical manifestations of acute attacks of porphyria is discussed.
Hemodynamics derived from Transesophageal Echocardiography (TEE)

Table 1 lists the parameters that are sought routinely in developing a complete hemodynamic profile by TEE. The arterial blood pressure is an essential starting point. Knowledge of the cardiac output (flow velocity integral) allows placement of the other parameters in context by providing a notion of the status of the general circulation and of the level of pulmonary and systemic vascular resistance. The mitral inflow allows segregation of the diastolic function of the left ventricle into one of three categories: (1) normal, (2) restrictive, or (3) delayed relaxation. Pulmonary vein inflow is complementary to mitral inflow and further confirms the status of the filling pressure. The MR jet is another means of gauging the systemic blood pressure and the filling pressure but is more technically demanding than recording mitral valve and pulmonary valve inflows. Tricuspid regurgitation, also technically demanding, reliably provides peak pulmonary systolic pressure, and PR provides the end-diastolic pulmonary artery pressure. Doppler [table: see text] flow in the great veins is useful in estimating right atrial pressure; this information must be integrated with TR and PR velocities to estimate pulmonary artery pressure. Finally, the motion and curvature direction of the IAS allows identification of the atrium with the higher pressure. Using the dynamic behavior of this structure enables reconstructing of the pressure in one atrium from knowledge of pressure in the other. As the case example shows, using these techniques in a routine fashion enables an accurate, comprehensive, and reliable qualitative assay of hemodynamic status.
Percutaneous Absorption of Sulconazole Nitrate in Humans

Abstract The percutaneous absorption of 1% sulconazole nitrate in a cream formulation containing 3 H-labeled drug has been studied in seven human subjects. Two applications of 4.5 g each were made to 450 cm 2 of abdominal skin at 0 and 12 h, and the site was washed at 24 h. The application site was subsequently washed at 24-h intervals for 3 consecutive days, and 6.7% of the dose was recovered in the urine and 2.0% in the feces following a 7-d collection period. Radioactivity was detectable in the plasma from 8–96 h, with a peak occurring at 24 h, and could also be recovered in the skin wash up to 96 h after application. Total percutaneous absorption of sulconazole was estimated to be 8.7-11.3% of the applied dose, considerably more than that previously reported for other imidazole drugs.
Detection of Left Ventricular Diverticulum by Cross-Sectional Echocardiography

This report describes the cross-sectional echocardiographic features of a left ventricular diverticulum. The echocardiographic findings are illustrated and discussed in relation to the diagnostic capabilities of this noninvasive imaging technique.
Colocalization of GABAA and NMDA receptors within the dorsal motor nucleus of the vagus nerve (DMV) of the rat

Changes in gastric motor activity are observed in response to glutamate and GABA in the DMV. We investigated the expression of GABA(A) and NMDA receptors within DMV neurons projecting to the stomach using pseudorabies virus (PRV). PRV immunoreactive (PRV-IR) cells expressing GABA(A) alpha1-IR, also expressed NMDAR1 suggesting that NMDA and GABA(A) receptors are colocalized. These results provide a neuroanatomical basis for these receptors jointly playing a role in gastric motor functions.
Does hue affect the perception of grayness

Although gray is defined as an achromatic color sensation varying only in lightness, in practice, grayness can be tinged by any hue within a limited range of chroma. Given the fact that preferred perceived white and black are slightly chromatic, the hypothesis tested in this study is that the preferred perceived object gray is also slightly chromatic. Two psychophysical experiments were carried out to test this hypothesis. A total of 56 color normal subjects assessed 27 different gray patches that varied mainly in hue, in three separate trials. Subjects selected a subset of samples (10 in the first experiment and five in the second experiment) that were considered “most gray” resulting in 168 selected sets of samples. Subjects then ranked their selected subset of samples from most to least gray. A total of 1225 assessments were thus obtained (750 assessments in the first experiment and 465 in the second experiment). Results from both experiments were in good agreement and indicate that greenish blue grays in the range of 190° to 235° of CIELAB hue angle were selected as most gray, thus indicating that the perception of grayness is influenced by hue. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 374–382, 2015
The Steward Observatory speckle interferometry program.

AbstractThe present status of the Steward Observatory speckle interferometer system and the asso-ciated reduction and image analysis programs are reviewed. Some recent results on solarsystem objects and quasars are reported.IntroductionThe speckle interferometry program at Steward Observatory was initiated approximately fouryears ago. Before describing the program itself I would, however, like to mention the mainparticipants, namely, K. Eege, E. Hubbard, N. Woolf, D. Rautenkrantz, J. Cocke and M. Gresham,all of whom have played key roles in various aspects of the work. We have also benefittedtremendously from the active participation of our colleagues at the Sacramento Peak Observa-tory, especially S. P. Worden, R. Radick and Julian Christou. The program has includedseveral parallel activities including development of instrumentation and basic reductionsoftware, analysis of atmospheric properties, work on image reconstruction techniques andobservations of a wide variety of astronomical objects (asteroids, planets, binary stars,Seyfert galaxy nuclei and quasars) and certain classes of orbiting satellites. The observa-tions have been carried out principally at the Steward Observatory 2.3m telescope on KittPeak and more recently the Multiple Mirror Telescope on Mount Hopkins.InstrumentationThe basic speckle camera is unchanged in principle from the system described by Hubbard
Autologous marrow transplantation after karyotypic conversion to normal in blastic phase of chronic myelocytic leukemia.

Abstract A patient with blastic transformation of Philadelphia chromosomepositive chronic myelocytic leukemia was treated with acridinyl anisidide, which resulted in conversion to a normal karyotype. At that time, bone marrow was harvested and cryopreserved. After relapse, the patient was treated with cyclophosphamide and fractionated total body irradiation followed by autologous marrow transplantation. Serial karyotypes and blood counts, determined up to 14 months after transplantation, remained normal.
The Neogene transition from C3 to C4 grasslands in North America: assemblage analysis of fossil phytoliths

Abstract The rapid ecological expansion of grasses with C4 photosynthesis at the end of the Neogene (8-2 Ma) is well documented in the fossil record of stable carbon isotopes. As one of the most profound vegetation changes to occur in recent geologic time, it paved the way for modern tropical grassland ecosystems. Changes in CO2 levels, seasonality, aridity, herbivory, and fire regime have all been suggested as potential triggers for this broadly synchronous change, long after the evolutionary origin of the C4 pathway in grasses. To date, these hypotheses have suffered from a lack of direct evidence for floral composition and structure during this important transition. This study aimed to remedy the problem by providing the first direct, relatively continuous record of vegetation change for the Great Plains of North America for the critical interval (ca. 12-2 Ma) using plant silica (phytolith) assemblages. Phytoliths were extracted from late Miocene–Pliocene paleosols in Nebraska and Kansas. Quantitative ...
Temporal properties of the red-green chromatic mechanism

The temporal properties of the red-green chromatic mechanism were studied with red and green equiluminant flashes of 1 deg diameter presented in the center of a bright (800-3000 td) yellow adapting field. A subthreshold 200 msec red or green flash makes an immediately subsequent, suprathreshold yellow luminance flash appear tinged with the complementary color. The chromatic flash also makes a subsequent chromatic flash of the same hue harder to detect and identify, and makes a flash of the opposite hue easier to detect and identify. These results indicate that the response of the red-green mechanism changes polarity during its time-course, suggesting that the chromatic temporal impulse-response function has a negative lobe. Pairs of chromatic pulses were used to estimate the shape of the chromatic impulse-response. The estimated impulse-response function has a zero crossing near 90 msec, followed by a long, shallow negative lobe. We also measured threshold-duration functions; the critical duration for the chromatic and luminance flashes is about 95 and 45 msec, respectively. Chromatic sensitivity (measured in cone contrast units) is 10 times greater than luminance sensitivity for long durations, and is 3 times greater for all durations less than 45 msec.
Transcript Profiles of Hexose Transporters in the Equine Gastrointestinal Tract

Abstract To test the hypothesis that hexose transporter transcripts are in lower abundance in the large compared with the small intestine of the horse, mRNA abundance of genes encoding for hexose transporters was quantified in small and large intestinal segments of the horse. Four adult horses were euthanized, and mucosal samples were taken from two segments of the small intestine (distal jejunum [DJ] and ileum [IL]) and three segments of the large intestine (cecum [CE], left ventral colon [LVC], and left dorsal colon [LDC]). Transcript abundance of candidate hexose transporter genes was determined using reverse transcription quantitative polymerase chain reaction. Primers for genes SLC2A1 , SLC2A2 , SLC2A5, and SLC5A1 , encoding for the hexose transporter proteins GLUT1, GLUT2, GLUT5, and SGLT1, respectively, were designed using gene sequences from GenBank. The 2 ΔΔC T method was used to compare mRNA abundance of candidate genes in the IL, CE, LVC, and LDC with that of the DJ. Relative to the DJ, mRNA abundance of GLUT1 was not different in the IL, CE, and LVC, and increased ( P ≤ .05) in the LDC. GLUT2, GLUT5, and SGLT1 gene expression was not different in the IL, and decreased ( P ≤ .01) in the CE, LVC, and LDC, relative to the DJ. The decrease in expression for the majority of the hexose transporter genes in the large intestine indicates that it has less capacity for glucose, galactose, or fructose absorption compared with the small intestine of the horse.
Semi-active controller dynamics in a magneto-rheological tuned vibration absorber

The primary objective of this study is to experimentally implement semi-active control to a Magneto-Rheological Tuned Vibration Absorber (MRTVA) and evaluate the dynamic performance of the MRTVA. The MRTVA is a semi-active TVA that employs an MR damper as its damping element. A test apparatus was built to represent a two-degree-of-freedom system-a primary structure coupled with an MRTVA. Using this test setup, a series of tests were performed to assess the dynamics of the MRTVA and to compare them with those of a passive TVA. The TVA used displacement-based, on-off groundhook (on-off DBG) control to regulate the MR damper. Unlike a passive TVA, the MRTVA was able to effectively control the resonant vibrations without sacrificing the isolation valley at high damping. To interpret the dynamics of the passive and semi-active system, the damper lock-up dynamics were investigated. The lock-up analysis further explains the actual implementation of the on-off DBG control policy in the system. The results of the lock-up analysis indicated that the dynamics of the control logic prevented lock-up in the MRTVA. This paper demonstrates that the MRTVA with the on-off DBG semi-active control can offer the benefits of high damping at the resonant peaks while still maintaining good isolation at the natural frequency of the structure. In other words, the semi-active TVA that employed an MR damper was more effective than an equivalent passive system in reducing vibrations of the primary structure.
Polymerase chain reaction detection of bacterial ribosomal genes from fresh and stored animal feeds

Feed quality can be influenced by both the microbial population levels and types of organisms that become associated with the feed matrices during processing and storage. Evaluation of microbial quality of animal feeds is difficult, because feeds generally contain a diverse bacterial population that can fluctuate widely depending on a variety of factors. Microbial diversity may be investigated in animal feed using the polymerase chain reaction (PCR) and 16S rDNA primers. In this study a bacterial isolation step involving centrifugation was combined with several DNA extraction techniques, and PCR amplicons were visualised on electrophoresis gels. Seven different animal feeds and two commonly used feed ingredients, either fresh or stored for approximately 14 months at −20 °C, were chosen (18 feed sources in total) to represent a variety of different matrices, concentrations of macronutrients such as protein and fat, and particle sizes. DNA extraction involving polyethylene glycol 8000 appeared to be the most reliable protocol for the extraction of community DNA for PCR analysis of feeds. The majority of the feeds (14 out of 18 animal feeds and feed ingredients) examined in this study yielded at least one PCR-positive replicate (1.1 kb band on gel), whereas no amplified products could be obtained from either of the other two DNA extraction protocols. Although some protocol refinement may be necessary for individual feeds, this approach has the potential to be a reliable method for monitoring microbial diversity changes in feeds and for rapid, simultaneous detection of a wide variety of micro-organisms in animal feeds during processing and storage. © 2002 Society of Chemical Industry
Exact transient results for pure and grazing indentation with friction

Exact transient 2D solutions are presented for pure and grazing indentation of elastic half-planes by rigid dies in the presence of friction. Slip is assumed to occur everywhere in this essentially first-step dynamic analysis, in accordance with the Coulomb model. Similarly, contact zone speeds are treated as sub-critical constants to be determined by the analysis. The results obtained for pure indentation by a wedge give an essentially linear contact zone expansion rate-indentation speed relation, and show that the region under the wedge apex is a potential site for tensile failure. The results for grazing indentation by a wedge give, on the other hand, a non-linear expansion rate-indentation speed relation. The short-time analysis of simultaneous punching and translation by a spring-loaded cylinder completes the study and, like the grazing wedge case, exhibits tangential contact zone velocities that are greater under the trailing side. These velocities, however, can reverse sign under the leading side, thereby suggesting small-scale material wrinkling as a surface wear precursor.
Poststroke Muscle Architectural Parameters of the Tibialis Anterior and the Potential Implications for Rehabilitation of Foot Drop

Poststroke dorsiflexor weakness and paretic limb foot drop increase the risk of stumbling and falling and decrease overall functional mobility. It is of interest whether dorsiflexor muscle weakness is primarily neurological in origin or whether morphological differences also contribute to the impairment. Ten poststroke hemiparetic individuals were imaged bilaterally using noninvasive medical imaging techniques. Magnetic resonance imaging was used to identify changes in tibialis anterior muscle volume and muscle belly length. Ultrasonography was used to measure fascicle length and pennation angle in a neutral position. We found no clinically meaningful bilateral differences in any architectural parameter across all subjects, which indicates that these subjects have the muscular capacity to dorsiflex their foot. Therefore, poststroke dorsiflexor weakness is primarily neural in origin and likely due to muscle activation failure or increased spasticity of the plantar flexors. The current finding suggests that electrical stimulation methods or additional neuromuscular retraining may be more beneficial than targeting muscle strength (i.e., increasing muscle mass).
The diagnosis of onboard generators (alternators)

In the paper selected problems related to diagnostics of onboard generators and alternators fitted with control systems are discussed. Problems refer to commutator generators and synchronous single- and threephase alternators. Special attention is paid to commutation effects. Results of incorrectness and possibility to detect them are discussed. There are also discussed effects associated with changes in a character of pulsation, which occur during shortings or insulation clearances in rotor or stator wiring. Possibility of diagnosis of generator’s or alternator’s parts by means of analysis of pulsation component parameters is indicated. In the case of alternators a number of diagnostic methods based on observation of changes in shape of voltage or frequency modulation, is discussed. This allows to detect many mechanical or electrical faults of generators, alternators or their control systems.
Enhanced fire control system filtering via refined air-to- air missile acceleration modeling

An extended Kalman filter is developed to aid the tracking of an air-to-air missile from a maneuvering target aircraft. The filter exploits knowledge of the dominant aerodynamically induced lift and drag forces of a non-thrusting missile employing proportional navigation guidance, and it also accounts for the dynamic lag and bandwidth effects of the missile seeker, guidance, and control systems. Incorporating the refined missile acceleration model enhances the filter's tracking estimate precision and provides meaningful threat predictive capabilities. Identifiability of parameters within the acceleration model is established, an adaptive filter is developed, and its performance capabilities portrayed through realistic Monte Carlo simulations.
An Empirical Assessment of Factors Affecting Corporate Debt Levels

Despite many efforts to develop a universally accepted theory of capital structure, observed capital structures do not appear to conform to existing theories. The objective of this research is to empirically examine capital structure decisions in terms of the relationship of debt policy with explanatory variables designed to capture the asset structure of each firm, the degree to which each firm is diversified, the agency relationships between management and owners, the level of business risk and the impact of alternative tax shields. The results suggest that the most influential factors are the asset type, the degree of firm diversification and the availability of alternative tax shields.
Uniform Stress Design in High-Voltage Cable Joints

This paper presents a method of determining whether a joint design is within the recommendations of the Underground Systems Reference Book and suggests a program for automatic computing of uniformly stressed cable joints. The method is based upon the computed solution to the equations given in reference 1. Their recommendations are based upon experience and surveys of actual splicing practice and make an allowance for the human factor as well as a factor of safety. The graphs presented here represent the, specific dimension Which gives the recommended maximum stress.
Measurement of the timescale of hygroscopic growth for atmospheric aerosols

[1] The rate of condensational growth is relevant to a variety of atmospheric processes, in particular the activation of cloud condensation nuclei to form cloud droplets. It has been hypothesized that the presence of organic films on the surface of aerosols can strongly inhibit condensational growth, but few relevant observations of atmospheric aerosol growth rates appear to have been previously reported. A brief review of the literature on the effects of films on the mass transfer of water is presented. A novel experiment based on tandem differential mobility analysis for the measurement of the timescale for condensational growth (τg) for ambient aerosols is introduced. Measurements were taken during the wet season (25–27 September 2000) and dry season (16–17 November 2000) in Mexico City for particles with diameters of 50 and 100 nm. The results show that most of the particles exhibit τg < 2 to 3 s. However, a small number (between 0 and 2.0% depending on particle size and season) do exhibit timescales larger than this. The accommodation coefficient of this minority of particles is estimated to be approximately in the range of 1 to 4 × 10−5, which is in the lowest range of observed values for laboratory aerosols. The observations show a strong dependence of the occurrence of such particles on season and time of day. It is hypothesized that these measurements suggest that an even larger concentration of particles exhibiting accommodation coefficients in the range of 10−5 to 10−4 may exist. The existence of such particles would be important to the indirect effect of aerosols on climate.
Structure-based determination of imaging length for super-resolution localization microscopy

Localization-based super-resolution techniques are revolutionizing biological research by breaking the diffraction limit of fluorescence microscopy. Each super-resolution image is reconstructed from a time series of images of randomly activated fluorophores. Here, a fundamental question is to determine the minimal imaging length so that the reconstructed image faithfully reflects the biological structures under observation. So far, proposed methods focus entirely on image resolution, which reflects localization uncertainty and fluorophore density, without taking into account the fact that images of biological structures are structured rather than random patterns. Here, we propose a different approach to determine imaging length based on direct quantification of image structural information using Gabor filters. Experimental results show that this approach is superior over approaches that only account for image-intensity distribution, confirming the importance of using structural information. In contrast to resolution-based methods, our method does not require an artificial selection of image resolution and provides a statistically rigorous strategy for determining imaging length based on image structural information.
Gas Phase Reactions of Transition Metal Clusters

The chemical reactions of isolated clusters of transition metal atoms with small molecules will be reviewed. Reactions of iron, cobalt, and nickel clusters with hydrogen, ammonia, water, and nitrogen will be considered. Experiments which determine the uptake of adsorbate molecules vs. reagent gas pressure provide information on kinetic and equilibrium processes, as well as a measure of the number of adsorbate binding sites on a cluster's surface. More detailed, quantitative determinations of reaction rate constants often show dramatic variation of reactivity with cluster size. Equilibrium studies provide measurements of cluster-adsorbate binding energies. A knowledge of the number of adsorbate binding sites often provides information about cluster geometrical structure.
Significant Geological Storage Capacity for Carbon in the United States, Report Finds

The United States has enough capacity to store a mean estimate of about 3000 metric gigatons (Gt) of carbon dioxide (CO2) through geological sequestration, according to a new assessment that looks at the potential for technically accessible geological CO2 storage in the country. That storage capacity is more than 500 times the nation's 2011 energy-related emissions, which the U.S. Energy Information Administration estimated at 5.5 Gt, and more than 90 times the 2011 global emissions of 31.6 Gt.
The structural proteins of scaleless-mutant chick epidermis

Abstract Epidermis isolated from the anterior tarsometatarsus region of scaleless mutant chick legs was found to contain only α fibrous protein rather than the usual feather one. The polyacrylamide disc electrophoretic pattern of structural proteins isolated from mutant epidermis was also different from that of normal tissue. X-ray diffraction analysis of the claw of mutant chicks, however, showed the usual feather pattern. These results indicated that failure of scale induction rather than a defect in synthesis of feather protein is the abnormality in the mutant chick.
What Is a “Semiotic Perspective”, and What Could It Be? Some Comments on the Contributions to This Special Issue

This comment attempts to identify different “semiotic perspectives” proposed by the authors of this special issue according to the problems they discuss. These problems can be distinguished as problems concerning the representation of mathematical knowledge, the definition and objectivity of meaning, epistemological questions of learning and activity in mathematics, and the social dimension of sign processes. The contributions are discussed so as to make visible further research perspectives with regard to “semiotics in mathematics education”.
The gas-phase decomposition of hydrazine and its methyl derivatives

The decomposition of hydrazine, hydrazine-water mixtures, UDMH, and monomethylhydrazine was studied in the Princeton adiabatic flow reactor. This reactor consisted of a cylindrical quartz section and a conical nozzle. The walls of the reactor were heated electrically to prevent heat loss. A hot carrier gas flowed through the reactor and was mixed rapidly with small quantities of gas-phase reactant, which is injected perpendicularly to the main stream at the throat of the nozzle. The mixing was followed by chemical reaction which could be extended over lengths as long as 30 in. Progress of the reaction was followed by measuring the longitudinal variation of temperature with a silica-coated platinum-PtRh thermocouple. Concentrations of reactant were generally less than 5% by volume, and the temperature regime of the study was 750 o –1000 o K. Also, chemical samples were taken with water-cooled probes near the end of the reaction zone. The over-all reaction order of all three monopropellants was very close to unity. The rate constant for hydrazine decomposition in a 3-in. duct was found to be k =10 10.33 exp (−36,170/ RT ) sec −1 , and the following stoichiometry was observed: N 2 H 4 →0.9 NH 3 +0.5 N 2 +0.6 H 2 A study of hydrazine-water mixtures showed their rates to be slower than those of the anhydrous material by approximately a factor of 10 and independent of the amount of water added. Slightly wet hydrazine behaved kinetically like the hydrazine-water mixtures. Thus, it seems that water inhibits the gaseous decomposition of hydrazine by very effectively suppressing some reaction step. UDMH was decomposed in 2-, 3-, and 4-in. ducts. No surface effect was observed. For the 2-in. duct, the first-order rate constant was found to be k =10 9.29 exp (−28,800/ RT ) sec −1 . Monomethylhydrazine was decomposed in 3-and 4-in. ducts. The over-all rate constant for MMH decomposition in the 3-in. duct was k =10 13.4 exp (−47,000/ RT ) sec −1 . The rates in the 4-in. duct were slightly lower. A comparison of the reaction rates of the three monopropellants shows that, in the temperature regime of this study, UDMH decomposition is the fastest, hydrazine decomposition is the slowest, and the monomethylhydrazine-decomposition rate is intermediate. A mechanism was postulated for hydrazine decomposition which differs from those suggested by other investigators, in that it includes a set of branching reactions N 2 H 3 +X→NH+NH 2 +X, N 2 H 4 +NH→NH 2 +N 2 H 3 . Rate constants computed from the mechanism agree closely with rates measured experimentally, and the computed stoichiometry agrees with that observed experimentally.
Phf7 Controls Male Sex Determination in the Drosophila Germline

Summary Establishment of germline sexual identity is critical for production of male and female germline stem cells, as well as sperm versus eggs. Here we identify PHD Finger Protein 7 (PHF7) as an important factor for male germline sexual identity in Drosophila . PHF7 exhibits male-specific expression in early germ cells, germline stem cells, and spermatogonia. It is important for germline stem cell maintenance and gametogenesis in males, whereas ectopic expression in female germ cells ablates the germline. Strikingly, expression of PHF7 promotes spermatogenesis in XX germ cells when they are present in a male soma. PHF7 homologs are also specifically expressed in the mammalian testis, and human PHF7 rescues Drosophila Phf7 mutants. PHF7 associates with chromatin, and both the human and fly proteins bind histone H3 N-terminal tails with a preference for dimethyl lysine 4 (H3K4me2). We propose that PHF7 acts as a conserved epigenetic "reader" that activates the male germline sexual program.
The pathway of left ventricular blood flow in healthy subjects and patients with corrected atrio-ventricular septum defect: an observational study using 4DFlow MRI and particle tracing

Background Blood entering the left ventricle (LV) through the left atrio-ventricular valve (LAVV) and exiting through the aorta is assumed to follow the most energy efficient pathway. In patients with a corrected atrio-ventricular septal defect (AVSD), this intra-cardiac blood flow pathway may be altered, due to the restricted opening of the LAVV. This might affect optimal LV function. Particle tracing in 4DFlow MRI data enables quantitative evaluation of the temporal distribution of blood particles in the LV. We aimed to compare the LV intra-cardiac blood flow pathway in corrected AVSD patients with that of healthy subjects, using 4DFlow MRI and particle tracing in the standard 16 segment model of the American Heart Association (AHA).
Trace metal dynamics in soils from a subalpine forest ecosystem

Abstract The distribution of total and DTPA-extractable soil trace metals varies significantly among pedogenic horizons in profiles from the subalpine forest zone of the Washington Cascades. Data from Spodosol profiles under old-growth, juvenile, and clearcut conditions indicate that trace metal distributions are modified by the same processes that govern the movement and arrest of Fe and A1 in soils. These profiles display 2–5 times greater metal concentrations in the illuvial, organic-rich B2 horizon than in the eluvial A2. Atmospheric deposition contributes relatively high concentrations (∼1kg ha−1yr−1) of Zn and Pb to this remote study area. Timber harvesting may indirectly alter the amount of atmospheric input to the soil. Trace metal concentrations in soil solutions collected by tension lysimetry are generally greater in the A2 than the B2 horizons. This trend is best exemplified by soluble Pb at the juvenile site and soluble Zn at the clearcut site.
Phenology and Density of Balsam Twig Aphid, Mindarus abietinus Koch (Homoptera: Aphididae) in Relation to Bud Break, Shoot Damage, and Value of Fir Christmas Trees

The balsam twig aphid, Mindarus abietinus Koch (Homoptera: Aphididae), is a major insect pest of balsam and Fraser fir grown for Christmas trees. Our objectives in this study were to 1) monitor the phenology of M. abietinus in fir plantations; 2) assess relationships among M. abietinus density, tree phenology, and damage to tree foliage; and 3) develop an esthetic injury level for M. abietinus on Christmas trees. We monitored phenology of M. abietinus and fir trees on three commercial Christmas tree plantations in central and northern Lower Michigan for 3 yr (1999–2001). Phenology of M. abietinus fundatrices and sexuparae was strongly correlated with accumulated degree-days (DD) base 10°C. Fundatrices matured by ≈83 DD10°C and sexuparae were first observed at ≈83–111 DD10°C. Trees that broke bud ≈1 wk later than other trees in the same field escaped M. abietinus damage and shoot expansion rate in spring was generally positively correlated with M. abietinus damage. Retail customers surveyed at a choose-and-cut Christmas plantation in 2 yr did not consistently differentiate between similarly sized trees with no, light, and moderate M. abietinus damage, but heavy damage (>50% damaged shoots) did affect customer perception. Similarly, when wholesale grades were assigned, the high quality Grade 1 trees had up to 40% shoot damage, whereas Grade 2 trees had 32–62% shoot damage. Two trees ranked as unsaleable had sparse canopies and distorted needles on 42% to almost 100% of the shoots.
A Proposed Reversible Mechanism Confirming Conformational Retention in 1, 12-Dimethyl[l. l]Ferrocenophane

Abstract Upon examination of the reaction of l, 12-dimethyi[l.l]ferrocenophane with the strong non-oxidizing acid boron trifluoride, a dication was formed. Upon dilution widi H2O, a bridge carbocation results. A mixture of exo-exo l, 12-dimethyl[l.l]ferro-cenophane and exo-endo l, 12-dimethyl[l.l]ferrocenophane should be observed, if the hydride is added direcdy back to the methylene bridge carbocation. However, when the hydride is added, retention of configuration is realized, indicating a significandy more complex mechanism of reaction. We propose that the iron centers and the methylene bridge participate through an intramolecular hydride migration which leads to retention of configuration.
Cytokine expression in adherent layers from patients with myelodysplastic syndrome and acute myelogenous leukemia

We have previously shown that long-term cultures of adherent layers derived from patients with chronic myelogenous leukemia in blast crisis express high levels of interleukin (IL)-1 beta and that this cytokine may participate in disease progression. In this study, we analyzed cytokine expression in bone marrow adherent layers derived from patients with myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML). IL-6 messenger RNA (mRNA) was expressed in adherent layers established from four of nine MDS patients, and from 10 of 17 AML patients (including all four individuals in whom AML had evolved from an antecedent MDS state). Similarly, IL-1 beta mRNA was expressed in adherent layers derived from two of nine MDS patients and from three of 17 AML patients. Cultures from two of 10 AML patients who expressed IL-6 also expressed granulocyte (G) colony-stimulating factor (CSF) mRNA. In contrast, IL-1 beta, IL-6, and G-CSF mRNA were not discernible in adherent layers from any of 14 normal volunteers. Transforming growth factor-beta 1, macrophage (M) CSF, IL-7, and leukemia inhibitory factor mRNA as well as IL-6 protein were constitutively expressed in adherent layers derived from both MDS patients, AML patients, and normal bone marrows, whereas IL-1 alpha, tumor necrosis factor-alpha, and GM-CSF were not expressed in either the normal-, MDS- or AML-derived adherent layers. These results indicate that cultured stroma from a subset of MDS and AML patients produce IL-1 beta and/or IL-6. Although, exposure of adherent layers to exogenous IL-1 beta was able to induce IL-6 expression, in 9 of the 14 samples constitutively expressing cytokines, IL-6 transcript levels were elevated without a concomitant increase in IL-1 beta, suggesting that IL-6 transcription was independently dysregulated.
Beam propagation in tapered quadratic-index waveguides: Analytical solutions

A Gaussian beam of light propagating through a quadratic lenslike medium remains Gaussian, even if all of the parameters of the medium vary along the propagation path. Exact numerical techniques are described for investigating the propagation of Gaussian beams in practical tapered fiber-optical waveguides. Solutions are obtained for off-axis beams in tapers which in general may also have quadratic radial loss variations.
Influence of joining on the fatigue and fracture behavior of high density polyethylene pipe

Polyethylene pipes have been used in a spectrum of corrosion-critical applications, including distribution systems for oil, gas, water, and chemicals. In this paper, the influence of joining on bending fatigue and fracture behavior of high density polyethylene pipe is presented and discussed, and performance is compared with a plain unwelded counterpart. High density polyethylene pipes were joined using electrofusion and butt-fusion techniques. Stiffness and strength of the electro-fusion joined pipe was far inferior to the butt-fusion and the plain unwelded pipe. Tensile failure of the butt-fusion joined specimen occurred at the fusion zone, while tensile failure of the electro-fusion joined pipe specimen occurred at the fusion joint. Bending fatigue resistance, quantified in terms of life to failure, of the pressurized pipe was superior to that of the unpressurized pipe. The fatigue resistance of the butt-fusion joined specimen was superior to that of the electro-fusion joined pipe specimen. The unwelded plain polyethylene pipe had bending fatigue resistance superior to that of the butt-fusion joined counterpart. Rationale for the differences observed in bending fatigue life is presented, and intrinsic differences in failure characteristics are highlighted.