cssi/SciSciGPT-SciSciNet huggingface dataset:
The congruence of Aristotle's rhetoric and poetics

Aristotle's Rhetoric and Poetics, two products of an incredibly productive mind, demonstrate a basic congruence of thinking within the disciplines of rhetoric and poetics. A remarkably consistent world view is applied both to the rhetorical and poetic arts.
Hyperpolarization-Activated Current (Ih) in Ganglion-Cell Photoreceptors

Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin and serve as the primary retinal drivers of non-image-forming visual functions such as circadian photoentrainment, the pupillary light reflex, and suppression of melatonin production in the pineal. Past electrophysiological studies of these cells have focused on their intrinsic photosensitivity and synaptic inputs. Much less is known about their voltage-gated channels and how these might shape their output to non-image-forming visual centers. Here, we show that rat ipRGCs retrolabeled from the suprachiasmatic nucleus (SCN) express a hyperpolarization-activated inwardly-rectifying current (Ih). This current is blocked by the known Ih blockers ZD7288 and extracellular cesium. As in other systems, including other retinal ganglion cells, Ih in ipRGCs is characterized by slow kinetics and a slightly greater permeability for K+ than for Na+. Unlike in other systems, however, Ih in ipRGCs apparently does not actively contribute to resting membrane potential. We also explore non-specific effects of the common Ih blocker ZD7288 on rebound depolarization and evoked spiking and discuss possible functional roles of Ih in non-image-forming vision. This study is the first to characterize Ih in a well-defined population of retinal ganglion cells, namely SCN-projecting ipRGCs.
Down syndrome patients with pulmonary hypertension have elevated plasma levels of asymmetric dimethylarginine

Down syndrome (DS) patients have an increased risk of developing pulmonary hypertension (PH). Increased plasma levels of asymmetric dimethylarginine (ADMA) may contribute to vascular dysfunction in adults with idiopathic pulmonary hypertension. Our goal was to test the hypothesis that DS patients with PH have higher plasma levels of ADMA than DS patients without PH. DS patients with definitive PH (n = 6) and DS patients with no evidence of PH (n = 12) were studied. Plasma levels of arginine, ADMA, and nitrite/nitrate (NOx; stable metabolites of nitric oxide (NO)) were measured. Plasma arginine concentration was lower (p < 0.05) in PH patients (23 ± 11 μM) versus non-PH patients (46 ± 24 μM). Plasma ADMA concentration was higher (p < 0.005) in PH patients (18.0 ± 4.2 μM) versus non-PH patients (8.6 ± 5.9 μM). Plasma NOx was lower (p < 0.05) in PH patients (4.5 ± 1.7 μM) versus non-PH patients (8.5 ± 7.3 μM). These results are consistent with ADMA contributing to lower NO production in DS patients with PH and suggest that ADMA levels may be a potential biomarker for PH in DS patients.
Cardiorespiratory variability following repeat acute hypoxia in the conscious SHR versus two normotensive rat strains

A link between exaggerated chemoreceptor sensitivity and hypertension has been documented in the spontaneously hypertensive rat (SHR) but has also been questioned when comparisons with normotensive strains other than the Wistar Kyoto (WKY) rat are made. To further evaluate the link between hypertension and chemoreflex sensitivity, changes in cardiorespiratory variability in response to three successive bouts of 5 min of hypoxia (21%→10%) were evaluated in conscious male SHR, and WKY and Sprague Dawley (SD) rats (n=7-8/group). In response to the first bout of hypoxia, the change in respiratory frequency (RF) was greatest in the SHR, but the increase in mean arterial pressure (MAP) was similar in both SHRs and WKY rats and all strains demonstrated a similar rise in heart rate (HR). All strains showed some level of response accommodation during subsequent bouts of hypoxia. Spectral analysis of HR variability identified a significant difference in high frequency (HF) power between strains during hypoxia, including an increase in HF power in the WKY rats, a decrease in the SHRs and little overall change in the SD rats. Alternatively, all strains demonstrated a rise in systolic arterial pressure (SAP) variability in the low frequency (LF) range in response to hypoxia but the increase was greatest in the SHR. Since SAP LF power is linked to vasosympathetic tone, these results support the hypothesis that essential hypertension is linked to exaggerated sympathetic responses to chemoreceptor stimulation but confirm that estimation of augmented reflex function cannot be determined by quantifying simple changes in MAP or HR.
Intracellular trafficking of P-glycoprotein

Overexpression of P-glycoprotein (P-gp) is a major cause of multidrug resistance in cancer. P-gp is mainly localized in the plasma membrane and can efflux structurally and chemically unrelated substrates, including anticancer drugs. P-gp is also localized in intracellular compartments, such as endoplasmic reticulum (ER), Golgi, endosomes and lysosomes, and cycles between endosomal compartments and the plasma membrane in a microtubular-actin dependent manner. Intracellular trafficking pathways for P-gp and participation of different Rab proteins depend on cellular polarization and choice of primary culture, cell line or neoplasm. Interruption of P-gp trafficking to the plasma membrane increases intracellular P-gp accumulation and anticancer drug levels, suggesting a potential approach to overcome P-gp-mediated multidrug resistance in cancer.
Modes, Weighted Modes, and Calibrated Modes: Evidence of Clustering Using Modality Tests*

We apply recent results from the statistics literature to test for multimodality of worldwide distributions of several (unweighted and population-weighted) measures of labor productivity. Specifically, we employ Silverman (Bump) and Dip modality tests, calibrated to correct for their incorrect asymptotic levels. We show that test results are sensitive to the test statistic employed and to population weighting. But regardless of the statistical criterion used, multimodality is present throughout, or emerges during, our sample period (1960-2000). We also examine (a) movements of economies between modal clusters and (b) relationships between certain key development factors and multimodality of the productivity distribution.
Genotype/phenotype of familial pancreatic cancer

It is estimated that 5% to 10% of pancreatic cancer cases are attributable to hereditary factors. We believe that the number of cases that are genetic in etiology are even greater, however, based not on a classic autosomal dominant pattern of inheritance but rather when one takes into account low-penetrant inherited susceptibility factors. There is also a growing recognition that the development of pancreatic cancer in pancreatic cancer-prone families is dependent not only on genetic variables but on nongenetic factors. The aim of this article is to review the challenges in identifying pancreatic cancer-prone families and how environmental factors interact with genetic factors in these families.
Characterization of a peptide alpha-amidation activity in human plasma and tissues.

Abstract Peptidyl glycine α-amidation activity has been detected in human plasma and in several human tissues known to synthesize biologically active α-amidated peptides. Activity was monitored by measuring conversion of mono-[125I]-D-Tyr-Val-Gly into mono-[125I]-D-Tyr-Val-NH2. The plasma α-amidation activity is dependent on molecular oxygen, copper, and ascorbic acid and appears to recognize a variety of peptide substrates which contain carboxyl terminal glycine residues. Kinetic analyses demonstrated Michaelis-Menten kinetics with a Km of 14 μmol/L for D-Tyr-Val-Gly. Based on gel filtration, the apparent molecular weight of the peptidyl glycine α-amidation activity in human serum is 60,000. The level of peptidyl glycine α-amidation activity in adult plasma (N = 17) was 106 ± 3 pmol/mL/h (Mean ± SEM) with no difference between male and female subjects (range 84 to 126 pmol/mL/h). In subjects under 15 years old (N = 10), mean plasma activity was 128 ± 10 pmol/mL/h, higher than values for adult control plasma (P
Baylisascaris procyonis in raccoons (Procyon lotor) in eastern Tennessee

Raccoon (Procyon lotor) carcasses (n=118) were collected from July through December 2007 throughout eastern Tennessee. Necropsies were performed, and Baylisascaris procyonis was collected from the gastrointestinal tract of infected carcasses. Prevalence rates were determined for the overall sample population, males and females, and adults and juveniles. The sample population had a B. procyonis prevalence of 12.7%. Males and females had a prevalence of 15% and 11%, respectively; prevalence in adults and juvenile was 13% and 12.6%, respectively. There were no significant differences in prevalence rates between the different groups. Baylisascaris procyonis is an ascarid infection of raccoons that can infect humans and over 100 species of other animals. The presence of infection in raccoons, paired with the expansion of human populations in eastern Tennessee, is likely to lead to increased interactions between humans and raccoons and therefore an increased risk of human and domestic animal exposure to B. procyonis.
Service quality, customer satisfaction, and behavioral intentions in fast‐food restaurants

Purpose – This study aims to explore the potential dimensions of service quality, and examine the relationship among service quality, food quality, perceived value, customer satisfaction and behavioral intentions in fast‐food restaurants (FFRs).Design/methodology/approach – The construct reliability and validity was assessed using exploratory factor analysis and confirmatory factor analysis. Structural equation modeling was employed to estimate the relationship among service quality, customer satisfaction, and behavioral intentions.Findings – Results indicated that five dimensions were significant: tangibles, reliability/responsiveness, recovery, assurance, and empathy. Service quality and food quality were two main determinants of customer satisfaction. The insignificance of perceived value is potentially due to the homogeneous nature of the construct within the FFR group rather than the importance of the perceived value construct within food service.Originality/value – The FFR success model, using the o...
Calorimetric Solution Properties of Simple Saccharides and Their Significance for the Stabilization of Biological Structure and Function

Thermodynamic and kinetic quantities were measured for 13 common saccharides: cellobiose, gentiobiose, glucose, lactose, lactulose, leucrose, maltose, melibiose, palatinose, raffinose, sucrose, trehalose, and turanose. Thermodynamic data included heats of solution (in water) of the amorphous and crystalline solids and melting temperatures. The glass transition temperature (Tg) and the increase in heat capacity at Tg were measured for each rigorously dried product. Many of these data were previously unavailable. We provided an interpretation of the heat of solution of the amorphous saccharides in terms of their capacity to hydrogen bond to water. A correlation was noted between the heats of solution of the amorphous carbohydrates and their Tg values. Furthermore, a thermodynamic analysis was performed to obtain values of the Gibbs free energy change for the amorphous-to-crystalline transformation at 25 °C.
Psychosocial correlates of sun protection behaviors among U.S. Hispanic adults

The incidence of skin cancer among U.S. Hispanics increased 1.3% annually from 1992 to 2008. However, little research has focused on skin cancer prevention among the rapidly growing Hispanic population. In this study, we examined theory-driven, psychosocial correlates of sun protection behaviors in a population-based sample of 787 Hispanic adults (49.6% female, mean age = 41.0 years) residing in five southern or western U.S. states. Participants completed an English- or Spanish-language online survey in September 2011. The outcomes of focus were sunscreen use, shade seeking, and use of sun protective clothing. The correlates included suntan benefits, sun protection benefits and barriers, skin color preference, perceived natural skin protection, photo-aging concerns, perceived skin cancer risk, skin cancer worry, skin cancer fatalism, and sun protection descriptive norms. Results of multiple linear regression analyses revealed the following: sun protection barriers were negatively associated with each outcome; descriptive norms were positively associated with each outcome; perceived natural skin protection was inversely associated with sunscreen use; skin cancer worry was positively associated with shade seeking and use of sun protective clothing; skin cancer fatalism was negatively associated with shade seeking; and skin color preference was negatively associated with use of sun protective clothing. A number of additional statistically significant associations were identified in bivariate correlation analyses. This study informs the potential content of interventions to promote engagement in sun protection behaviors among U.S. Hispanics.
Seismic behavior of a high‐strength concrete framed tube

An integrated analytical/experimental study is conducted to investigate the use of high-strength concrete (8 000–10 000 psi) in high-rise framed tube structural systems located in areas of high seismic risk. Results indicate that displacement demands from recorded strong ground motions are less than that which can be supplied by critical beam-to-column joints in the designed structure. Furthermore, the structural system offers high lateral stiffness, high redundancy and high energy dissipation through well-distributed plastic hinging in the spandrel girders. © 1997 John Wiley & Sons, Ltd.
Biophysical probes of iron metabolism in cells and organelles

In living systems, iron is found in many different structures, including Fe/S clusters, hemes and nonheme centers, and magnetically interacting aggregates. Understanding Fe metabolism and trafficking will require biophysical spectroscopic tools that can evaluate the types of Fe centers within entire cells and isolated organelles. Mossbauer spectroscopy will play an important role in such analyses, as it has perhaps the best combination of resolution, sensitivity, coverage, and quantifying abilities. Other spectroscopic techniques, with particular strengths, will be used in combination with Mossbauer, and results will be integrated to assess the 'ironome' of such complex samples. This integrative biophysical approach is illustrated by a discussion of iron trafficking in yeast cells.
Skeletal muscle NAD(P)H two-photon fluorescence microscopy in vivo: topology and optical inner filters.

Two-photon excitation fluorescence microscopy (TPEFM) permits the investigation of the topology of intercellular events within living animals. TPEFM was used to monitor the distribution of mitochondrial reduced nicotinamide adenine dinucleotide (NAD(P)H) in murine skeletal muscle in vivo. NAD(P)H fluorescence emission was monitored (∼460 nm) using 710–720 nm excitation. High-resolution TPEFM images were collected up to a depth of 150 μm from the surface of the tibialis anterior muscle. The NAD(P)H fluorescence images revealed subcellular structures consistent with subsarcolemmal, perivascular, intersarcomeric, and paranuclear mitochondria. In vivo fiber typing between IIB and IIA/D fibers was possible using the distribution and content of mitochondria from the NAD(P)H fluorescence signal. The intersarcomeric mitochondria concentrated at the Z-line in the IIB fiber types resulting in a periodic pattern with a spacing of one sarcomere (2.34 ± 0.17 μm). The primary inner filter effects were nearly equivalent to water, however, the secondary inner filter effects were highly significant and dynamically affected the observed emission frequency and amplitude of the NAD(P)H fluorescence signal. These data demonstrate the feasibility, and highlight the complexity, of using NAD(P)H TPEFM in skeletal muscle to characterize the topology and metabolic function of mitochondria within the living mouse.
Gauging The Boundaries Of Second Language Competence: A Study Of Learner Judgments

Second language learners can make judgments as to the acceptability of verbal sequences in a target language text. However, such judgments are often different from judgments of the same text by native speakers of the target language. These differences can be interpreted as a gauge of differences between the learners' transitional competence and the competence of native speakers. Similarly, changes in learner judgments may indicate changes in transitional competence. The latter part of this paper reports a study in which learner judgments are used to test a model of change in learner competence proposed by S. Pit Corder (1971) and an extension of that model proposed by Jacquelyn Schachter, Adele F. Tyson, and Frank J. Diffley (1976).
Hydrocode modeling of Chicxulub as an oblique impact event

Abstract Since the confirmation that the buried Chicxulub structure is the long-sought K/T boundary crater, numerous efforts have been devoted to modeling the impact event and estimating the amount of target material that underwent melting and vaporization. Previous hydrocode simulations modeled the Chicxulub event as a vertical impact. We carried out a series of three-dimensional (3D) hydrocode simulations of the Chicxulub impact event to study how the impact angle affects the results of impact events. The simulations model an asteroid, 10 km in diameter, impacting at 20 km/s on a target resembling the lithology of the Chicxulub site. The angles of impact modeled are 90° (vertical), 60°, 45°, 30°, and 15°. We find that the amount of sediments (surface layer) vaporized in the impact reaches a maximum for an impact angle of 30° from the surface, corresponding to less than two times the amount of vaporization for the vertical case. The degassing of the sedimentary layer, however, drops abruptly for a 15° impact angle. The amount of continental crust melted in the impact decreases monotonically (a consequence of the decrease in the maximum depth of melting) from the vertical impact case to the 15° impact. Melting and vaporization occur primarily in the downrange direction for oblique impacts, due to asymmetries in the strength of the shock wave with respect to the point of impact. The results can be used to scale the information from the available vertical simulations to correct for the angle of impact. A comparison of a 3D vertical impact simulation with a similar two-dimensional (2D) simulation shows good agreement between vertical 3D and 2D simulations.
Relational control in physician-patient encounters.

To further exploratory work done by O'Hair (1989) in applying relational communication theory to physician-patient communication, this study analyzed 30 transcripts of conversations between physicians and patients with 5,968 utterances and 5,929 exchanges in four contexts: an AIDS clinic, an institutional or home hospice program, a family practice clinic, and hospital rooms or doctor's offices. Results differed from O'Hair's exploratory study in that the predominant transaction control type across all contexts was neutralized symmetry, rather than complementary. Both physicians and patients tended to concentrate messages into three of the nine relational categories: extension, support, and answer. Physicians asked more questions and changed the topic frequently, particularly when the patients raised emotional issues. Physicians did not answer all questions asked by patients. The findings suggest a tendency toward domineering behavior on the part of the patient and a tendency toward control through questio...
Effect of Misfit Strain Relaxation on Nonlinear Dielectric Properties of Epitaxial (Ba 0.60 Sr 0.40 ) Thin Films on NdGaO 3

Strain relaxation in (Ba 0.60 Sr 0.40 ) TiO 3 epitaxial films on ≪110≫-oriented NdGaO 3 substrates is investigated in the thickness range, h= 25-1200 nm. The BST films prepared by PLD show that residual strains mostly relax by h 200 nm, and for h≫600 nm films are essentially strain free. Two independent dislocation mechanisms operate to relax anisotropic strains along the principal directions. The critical thickness for misfit dislocation formation along [001] and [010] were found to be 11 and 15 nm, respectively. Deviation from linear elasticity for h≪200 was observed, and increased as thickness decreased. Films with h≪25 nm are monoclinic due to a finite principal shear stress along [110] of the BST cell. The effects of misfit strain relaxation on the nonlinear dielectric response and tunability will be discussed as well. The in plane dielectric response demonstrates a directional dependence that increases with the magnitude of the residual strain.
Solid Solution and Chromium Oxide Loss in Part of the System MgO-Al2O3-Cr2O3-SiO2

Thermal and X-ray studies show that there is complete solid solution between MgO.Cr2O3 and MgO.Al2O3 and that the spinel solid solutions are stable with no exsolution down to temperatures as low as 510°C. There is no solid solution of excess Cr2O3 in MgO.Cr2O3 nor of MgO.Cr2O3 in Cr2O3. The join MgO.Cr2O3–Al2O3 is found to be nonbinary; compositions along that join yield mixtures of a chromium oxide-alumina solid solution and a spinel solid solution on firing to temperatures high enough to promote solid-state reaction. Chromium oxide loss by volatilization increases at higher temperature. At a given temperature, chromium oxide loss is found to vary directly with the partial pressure of oxygen in the furnace atmosphere and with the ratio of MgO to SiO2 in the charges heated.
The craniocaudal extent of the glycogen body in the domestic chicken

All birds have a glial enclosed, glycogen-containing structure in the lumbosacral region of their spinal cords. Recently, a dorsal, central, glycogen-rich area surrounding the central canal in the brachial spinal cord was described in domestic chickens. In order to topographically delineate and histochemically describe this structure, fresh, frozen serial sections of chicken brains and spinal cords were processed for glycogen content, phosphorylase, succinic dehydrogenase and cholinesterase activities. The glycogen-rich area surrounding the central canal in the lumbosacral region is found at all levels of the spinal cord and lower medulla. In the upper medulla, it is located in the medline floor immediately ventral to the ependyma. It persists in this position until the level of the oculomotor complex where it ends. Phosphorylase positive regions closely parallel the glycogen distribution. No succinic dehydrogenase or cholinesterase activities are found in these areas.
In vitro Reactions of Alkaloids I: Decarbalkoxylation of Some Esters with Quinine Monohydrate and Perloline Hydrochloride

Abstract We wish to describe the decarbalkoxylation of selected esters with the alkaloids quinine monohydrate (1) and perloline hydrochloride (2). Quinine has been effectively used for medicinal purposes and is the most important constituent of two Rubiaceous genera, Cinchona and Remijia 1. Perloline2 occurs in several species of grass and has been found to be inhibitory to seed germination, root elongation, protozoa mobility and cellulytic activity3. The stimulation of volatile fatty acid production by the alkaloid perloline is particularly noteworthy3.
The born global firm: An Entrepreneurial and capabilities perspective on early and rapid internationalization

Our 2004 Journal of International Business Studies article, “Innovation, Organizational Capabilities, and the Born Global Firm” provided a framework for the phenomenon of early and rapid internationalization among young, entrepreneurial firms. This work can be characterized as an integration of marketing, entrepreneurial, and capability-based thinking around exporting, positioned as the born global exporter. The article also reported findings from a national study of start-up firms that expanded abroad early in their evolution. In the present commentary, we reflect on the contributions of the 2004 article, review the scholarship on the topic over the past decade, and offer suggestions for future inquiry. While the incidence of early internationalization by firms was a novel concept two decades ago, today such firms are found in abundance in many countries. Yet many unresolved research questions remain, including the crucial topic of what happens to “born global” firms as they grow and mature over time. Similarly, the issue of why some firms internationalize early, others late in their evolution, and still others choose to remain local, is a fundamental question for international business scholarship.
Changes in phospholipase D experession in soybeans during seed development and germination

Activation of phospholipase D (PLD) has been linked to accumulation of nonhydratable phosphatides and lipid degradation leading to soybean seed deterioration during preharvest and postharvest events. This study examined the changes in PLD activity, protein, and mRNA in soybeans during seed development and germination. RNA blotting analysis indicated that expression of the gene that encodes PLD was highest during the early and middle stages of seed development. However, the amount of PLD activity accumulated per cotyledon reached the highest level in mature seeds. During germination and early seedling growth, PLD mRNA was not detected one day after imbibition, while a significant increase in PLD expression occurred in the cotyledons of three- and seven-day seedlings. Similarly, PLD activity and protein concentration showed little change during the first day of imbibition and increased afterward in three- and seven-day seedlings. These results suggested that expression of PLD is developmentally regulated and that the changes in its amount of activity and protein are controlled primarily at the mRNA level. Immunoblotting analysis further revealed the presence of PLD variants that were associated with specific stages of seed development and seedling growth. The PLD variants present in the cotyledons of mature seeds appeared to be distinct from those observed in the early stage of seed development and in young seedlings.
Media exposure and appraisal: Phase II, tests of a model in Nigeria

This study represents the second phase of a programmatic research effort designed to test a model of media exposure and appraisal. One of the distinguishing features of the model is that it attempts to link directly individual evaluations of a particular medium to exposure and appraisal. In the model three independent variables, editorial tone, communication potential, and utility, are posited to determine exposure and appraisal. This model was tested with two readership surveys of magazines distributed in Nigeria. While the model provided a good fit to the data, the results suggested that a contingency approach, based on specific attributes of a medium and situational factors, may be necessary to account for the effects of specific patterns of media exposure and appraisal.
Multidimensional Approximation Algorithms for Capacity-Expansion Problems

We develop multidimensional balancing algorithms to compute provably near-optimal capacity-expansion policies. Our approach is computationally efficient and guaranteed to produce a policy with total expected cost of no more than twice that of an optimal policy. We overcome the curse of dimensionality by introducing novel cost-separation schemes to separate the lost-sales cost of the system into exact monotonic subparts. This is the first approximation technique for multimachine, multiproduct systems facing stochastic, nonstationary, and correlated demands. To show the generality of this separation technique, we apply it to the capacity-expansion problem under two different production planning models: monotone production and revenue-maximizing production. We make the assumptions of minimal inventory and lost sales.
Role of insulin receptors in insulin-resistant states

The interaction of insulin with its receptor represents one of the key intermediate steps between secretion of insulin and its final biologic effects. Alterations in this interaction have been found in a number of disease states, including obesity, non-insulin-dependent diabetes mellitus (NIDDM), glucocorticoid excess, and acromegaly, as well as several rare forms of severe insulin resistance. The major factor regulating the receptor in obesity and NIDDM appears to be insulin. In obesity this alteration in normal regulation occurs secondary to overeating, whereas in the diabetic state the nature of the primary defect is uncertain. The role of the receptor in insulin resistance and methods for its evaluation are discussed.
Online digital computer measurement of a neurological control system

Quantative measurements of the neurological control system for hand movement have shown results both of diagnostic value and of theoretical interest in understanding the underlying neural mechanisms and their system organization [1-4]. The requirement for dynamic analysis for a complex unpredictable input is necessary in order to distinguish between behavior attributable to the “neurological” system and that due to the powerful brain prediction apparatus.In order to meet this need, reduce the hidden errors in analyzing filtered data, permit shorter experiments (and thus less dependence upon assumptions of time invariance) and eliminate painstaking pencil-and-ruler analysis, we have inaugurated an online digital computer system for this and related experiments. The RW-300 computer is a magnetic-drum (8000 18-bit words), solid-state computer that is often used in process control applications.1 It has integral analog-to-digital and digital-to-analog conversion facilities.
Life‐cycle exposure of fathead minnows (Pimephales promelas) to an ethinylestradiol concentration below 1 ng/L reduces egg fertilization success and demasculinizes males

Forty-eight hours after fertilization, fathead minnow (Pimephales promelas) eggs were exposed to the synthetic estrogen 17alpha-ethinylestradiol (EE2) at nominal concentrations of 0.32 and 0.96 ng/L and measured concentrations of 3.5, 9.6, and 23 ng/L. The fish were observed through the larval, juvenile, and adult stages. Growth, secondary sex characteristics, the liver somatic index, the gonadosomatic index, and fecundity were examined after several lengths of exposure. No significant changes were seen in fry or juvenile growth from 8 to 30 days posthatch (dph). An increase in the ovipositor index (a female secondary sex characteristic) was the most sensitive early response at 60 dph and was seen in fish exposed to EE2 concentrations > or = 3.5 ng/L. Continuation of the EE2 exposure until 150 dph, through maturation and reproduction, allowed measurement of two sensitive end points: decreased egg fertilization and sex ratio (skewed toward females), both of which were significantly affected at the lowest EE2 concentration tested, 0.32 ng/L. The next most sensitive end point was demasculinization (decreased male secondary sex characteristic index) of males exposed to an EE2 concentration of 0.96 ng/L. The effects of low concentrations of EE2 (0.32 and 0.96 ng/L) were manifested in male fish (decreased male sex characteristics and reduced egg fertilization success), whereas female fish showed no changes in the gonadosomatic index. Exposure to higher EE2 concentrations negatively affected females, as shown by a reduced gonadosomatic index at 150 dph in fish exposed to > or =3.5 ng/L EE2. Although there were some end points that showed changes at 60 dph, the reproductive end points and external sex characteristics measured in mature fish at 150 dph were more sensitive, with response thresholds of EE2 ranging from 0.32 to 0.96 ng/L. The concentrations of EE2 that negatively affected fathead minnows were similar to or lower than those detected in many municipal wastewater effluents. In conclusion, life-cycle exposure of fathead minnows proved to be a very sensitive bioassay, and responses were seen at concentrations of less than 1 ng/L, which are environmentally relevant concentrations of EE2.
Photointermediates of the Rhodopsin S186A Mutant as a Probe of the Hydrogen-Bond Network in the Chromophore Pocket and the Mechanism of Counterion Switch†

The role of a specific serine located in the retinylidene chromophore-binding pocket of bovine rhodopsin was investigated to determine its role in the mechanism of receptor photoactivaiton. The S18...
The interaction of directional lone pairs between bonded atoms: Hydrazine

The directional components of the barrier to rotation in hydrazine are investigated. The repulsion of the lone pairs appears to be significant, favoring the form with perpendicular lone pairs over the syn and anti forms.[/p]
The Chosen Women in Korean Politics: An Anthropological Study

Preface Introduction A Cultural Account Family Backgrounds and Education Other Personal Characteristics Pathways to the National Assembly Winning Legislative Seats Patterns of Adaptive Response Private Meanings and Public Images Conclusion Appendix: Biographical Notes on Elected Women Legislators Glossary References Index
Morphology and dynamics of 2D Sn-Cu alloys on (100) and (111) Cu surfaces

We have performed calculations of Sn deposition on Cu(111) and Cu(100) surfaces. The atomic interactions are described by modified embedded atom method (MEAM) potentials. This is a modification of the embedded atom method (EAM) to include higher moments in the electron density. We find that at low coverages Sn deposited on Cu(111) leads to the formation of a two-dimensional (2D) alloy phase with a p((3)1/2×(3)1/2)-R 30° structure which is stable up to temperatures of 1200 K. For deposition of Sn on Cu(100), a coverage of one-quarter of a monolayer results in the formation of a stable 2D alloy phase with a p(2×2) structure. These results are in agreement with ion-scattering experiments. It is found that on both Cu(100) and Cu(111) surfaces, the resulting alloy phases are rippled with the Sn atoms displaced outward from the surfaces.
Stabilization of a hydrated ketone by metal complexation. The crystal and molecular structures of bis-2,2′,N,N′-bipyridyl ketone-hydrate nickel(II) sulfate, copper(II) chloride and copper(II) nitrate

Abstract The crystal structure of the complexes (I)Ni[C11N8N2(OH)2]2SO4, (II) Cu[C11H8N2(OH)2]2Cl2· 4H2O and (III) Cu[C11H8N2(OH)2]2(NO3)2·2H2O have been determined by three-dimensional X-ray analysis methods. Crystal data are: (I), monoclinic, space group C2/c, Z = 4, a = 19.666(4), b = 7.994(2), c = 16.045(6) /rA, /gb = 111.231(9)°, (II), monoclinic, space group C2/c, Z = 4, a = 14.504(4), b = 12.333(8), c = 14.630(3) A, /gb = 90.92°; and (IIl), monoclinic, space group P21/n, Z = 2, a = 7.601(5), b = 11.977(4), c = 14.463(6) A, β = 93.10(8)°. These structural investigations clearly demonstrate that in each case hydration occurs across the ketone double bond in the ligand and that the resulting hydroxyl group coordinates to the metal. Two di-2-pyridyl ketone ligands are thus bonded to the metal atom in a tridentate fashion. In the nickel complex (I), all six coordination interactions appear to have approximately the same strength. However, in the copper complexes (II) and (III), the pyridyl nitrogens are strongly coordinating to the metal in the equatorial plane, while the hydroxyl groups are more weakly coordinating in the axial direction. The metal to ligand bond distances are: (I) dNi−O = 2.098(4), dNiN = 2.062(4), 2.087(4) A, (II) dCuO = 2.465(5), dCuN = 1.994(5), 2.006(5) A, (III) dCuO = 2.464(5), dCuN = 1.990(5), 2.036(5) A. The neutral diol that results from hydrolysis of di-2-pyridyl ketone is stabilized by coordination to the metal and such coordination is little affected by changes in the metal, the anion or the extent of hydration.
Characterization and 3D reservoir modelling of fluvial sandstones of the Williams Fork Formation, Rulison Field, Piceance Basin, Colorado, USA

This study describes the stratigraphic characteristics and distribution of fluvial deposits of the Upper Cretaceous Williams Fork Formation in a portion of Rulison Field and addresses 3D geologic modelling of reservoir sand bodies and their associated connectivity. Fluvial deposits include isolated and stacked point-bar deposits, crevasse splays and overbank (floodplain) mudrock. Within the Williams Fork Formation, the distribution and connectivity of fluvial sandstones significantly impact reservoir productivity and ultimate recovery. The reservoir sandstones are primarily fluvial point-bar deposits interbedded with shales and coals. Because of the lenticular geometry and limited lateral extent of the reservoir sandstones (common apparent widths of ∼500–1000 ft; ∼150–300 m), relatively high well densities (e.g. 10 acre (660 ft; 200 m) spacing) are often required to deplete the reservoir. Heterogeneity of these fluvial deposits includes larger scale stratigraphic variability associated with vertical stacking patterns and structural heterogeneities associated with faults that exhibit lateral and reverse offsets. The discontinuous character of the fluvial sandstones and lack of distinct marker beds in the middle and upper parts of the Williams Fork Formation make correlation between wells tenuous, even at a 10 acre well spacing. Some intervals of thicker and amalgamated sandstones within the middle and upper Williams Fork Formation can be correlated across greater distances. To aid correlation and for 3D reservoir modelling, vertical lithology proportion curves were used to estimate stratigraphic trends and define the stratigraphic zonation within the reservoir interval. Object-based and indicator-based modelling methods have been applied to the same data and results from the models were compared. Results from the 3D modelling indicate that sandstone connectivity increases with net-to-gross ratio and, at lower net-to-gross ratios (<30%), differences exist in the cumulative volume of connected sandstone bodies between the indicator- and object-based lithology models. Therefore, the types of lithology-modelling methods used for lower net-to-gross ratio reservoir intervals are important.
Membrane Refractoriness and Excitation Induced in Cardiac Fibers by Monophasic and Biphasic Shocks

Cardiac Fiber Responses to Defibrillation Shocks. Introduction: This modeling study examines the effect of low-intensity monophasic and biphasic waveforms on the response of a refractory cardiac fiber to the defibrillation shock. Methods and Results: Two cardiac fiber representations are considered in this study: a continuous fiber and a discrete fiber that incorporates gap junctions. Each fiber is undergoing a propagating action potential. Shocks of various strengths and coupling intervals are delivered extracellularly at fiber ends during the relative refractory period. In a continuous fiber, monophasic shock strengths of three times the diastolic threshold either elicit no response or, for coupling intervals above 380 msec, reinitiate propagation. In contrast, biphasic shocks of same strength are capable of terminating the existing wavefronts by either invoking a non-propagating response (coupling intervals 370 to 382 msec) that prolongs the refractory period or inducing wavefront collision (coupling intervals above 400 msec). The fiber response is similar for other shock strengths and when cellular discontinuity is accounted for. Thus, for a refractory fiber, biphasic shocks have only a small “vulnerable” window of coupling intervals over which propagation is reinitiated. Conclusion: At short coupling intervals, a significant extension of refractoriness is generated at regions where the biphasic shock induced hyperpolarization followed by depolarization. At large coupling intervals, the enhanced efficacy of biphasic shocks is associated with their ability to induce wavefront collision, thus decreasing the probability of reinitiating fibrillation. Overall, the defibrillation shock affects the tissue through the induced large-scale hyperpolarization and depolarization, and not through the small-scale transmembrane potential oscillations at cell ends.
MOUSE LEUKOCYTES IN CULTURE.

SummaryEfforts to establish a routine method for in vitro culture of mouse peripheral blood leukocytes are described. These cells generally failed to respond mitotically to PHA under a wide variety of culture conditions, In diffusion chambers placed in the peritoneal cavity of mice, however, proliferative activity of leukocytes was observed. Failure to obtain successful in vitro cultures therefore is probably attributable to culture conditions unfavorable for support of mouse leukocytes.
Role of phosphatidylinositol 3-kinase-γ in mediating lung neutrophil sequestration and vascular injury induced by E. coli sepsis

We addressed the in vivo role of phosphatidylinositol 3-kinase-γ (PI3K-γ) in signaling the sequestration of polymorphonuclear leukocytes (PMNs) in lungs and in the mechanism of inflammatory lung va...
Anti-Insulin IgE in Diabetics

Anti-insulin IgE and IgG were estimated in sera of diabetic patients. Using a paper radioimmunosorbent technique, detectable titers of anti-insulin IgE were found in all insulin-treated diabetics who were non-allergic to insulin. Patients with generalized insulin allergy, and immune-type insulin-resistance had higher titers of anti-insulin IgE. Anti-insulin IgG was present in all insulin-treated patients. The titers were significantly higher in insulin-resistant diabetics. Four of the 12 cases with insulin allergy had undetectable anti-insulin IgG titers. The ratios of 125I-insulin bound by IgE and IgG were significantly higher in 11 (91%) patients with systemic insulin-allergy. It is suggested that a relative excess of anti-insulin IgE may be associated with the insulin allergic state.
Apoptosis of Rat Vascular Smooth Muscle Cells Is Regulated by p53-Dependent and -Independent Pathways

Abstract Apoptosis of vascular smooth muscle cells has recently been described in culture and also in remodeling of the artery after birth. However, the genes that regulate apoptosis in smooth muscle cells are mostly unknown. We studied the regulation of apoptosis in rat smooth muscle cells stably infected with retrovirus constructs containing c-myc, adenovirus E1A, bcl-2, and a temperature-sensitive mutant of the tumor suppressor gene p53. Apoptosis was verified by electron microscopy and quantified by time-lapse videomicroscopy. Death was induced by c-myc and E1A when cells were deprived of serum survival factors. bcl-2 suppressed apoptosis of cells infected with c-myc and E1A and also normal smooth muscle cells. Overexpression of wild-type p53 induced apoptosis of cells infected with E1A and c-myc but not normal cells. In contrast, expression of mutant p53, which blocks wild-type p53 function, suppressed apoptosis of cells infected with E1A or c-myc but not normal cells. Both adenovirus E1A and c-myc i...
Well-Posedness of the Prandtl Boundary Layer Equations for the Upper Convected Maxwell Fluid

We prove the well-posedness of the Prandtl boundary layer equations for the upper convected Maxwell fluid under the assumption that the stress tensor is strictly positive definite.
A language for compositional specification and verification of finite state hardware controllers

The authors consider the state machine language (SML) for describing complex finite state hardware controllers. It provides many of the standard control structures found in modern programming languages. The state tables produced by the SML compiler can be used as input to a temporal logic model checker that can automatically determine whether a specification in the logic CTL is satisfied. The authors describe extensions to SML for the design of modular controllers. These extensions allow a compositional approach to model checking which can substantially reduce its complexity. To demonstrate these methods, the authors discuss the specification and verification of a simple central-processing-unit (CPU) controller. >
Ras-independent activation of Ral by a Ca2+-dependent pathway

The RalA and RalB proteins comprise a distinct family of small GTPases [1]. Ral-specific guanine-nucleotide exchange factors such as RalGDS, Rlf and RGL interact with activated Ras and cooperate with Ras in the transformation of murine fibroblasts [2-5]. Thus, the interaction of RalGDS with Ras and the subsequent activation of Ral are thought to constitute a distinct Ras-dependent signaling pathway. The function of Ral is largely unknown. There is circumstantial evidence that Ral may have a function in regulating the cytoskeleton through its interaction with RIP1 (also known as RLIP or RalBP1), a GTPase-activating protein specific for the small GTPases Cdc42 and Rac [6-8]. Ral also binds to phospholipase D (PLD) and thus may play a role in signaling through phospholipids [9]. We have examined endogenous levels of activated, GTP-bound Ral (Ral-GTP) in Rat-2 fibroblasts stimulated with various mitogens. Lysophosphatidic acid (LPA) and epidermal growth factor (EGF), which activate both Ras-dependent and Ras-independent signaling pathways [10,11], rapidly activated Ral. Inhibition of Ras activation by dominant-negative Ras (RasS17N) or pertussis toxin had little effect on Ral-GTP levels, however. Ral was activated by the Ca2+ ionophore ionomycin, and activation by LPA or EGF could be blocked by a phospholipase C (PLC) inhibitor. The results presented here demonstrate a Ca(2+)-dependent mechanism for the activation of Ral.
Screening for Drought Tolerance: Soybean Germination and its Relationship to Seedling Responses

Seventeen determinate soybean (Glycine max L.) cultivars from maturity groups V through VIII were screened for drought tolerance during germination and seedling stages. Germinating seeds and hydroponically-grown seedlings were subjected to osmotic stresses of -0.3 and -0.5 MPa using polyethylene glycol M.W. 8000. Genotypic variability was found among the cultivars for all the parameters analyzed in both germination and seedling tests. Germination stress index was lower for seeds exposed to -0.5 MPa than for -0.3 MPa osmotic stress. Lower osmotic potential in the treatment medium was also correlated with lower leaf water potential in seedlings subjected to it. A significant relationship was found between fresh weight and height stress indices. The cultivars that grew taller under drought stress conditions had greater dry matter accumulation and higher germination stress indices indicating the reliability of height to predict cultivar performance under such conditions. The cultivars Lee-74 and Wright had higher dry matter accumulation, greater height, and better germination under stress conditions than the other cultivars tested. Conversely, the cultivars Ra 401 and Bay performed poorly in the drought tests at both levels. In the seedling tests, there was no strong relationship between the leaf water potential and the overall performance of the plant suggesting no clear osmoregulatory mechanism. Based on results from germination and seedling tests, the cultivars Lee-74, Wright, and Ra 401 were selected for further studies in greenhouse and field trials.
Cloning, Characterization, and Tissue Expression Pattern of Mouse Tuftelin cDNA

Tuftelin is a protein that has been suggested to function during enamel crystal nucleation. Published sequences for bovine tuftelin cDNA and genomic clones proposed different reading frames that radically affected the derived amino acid sequence of the tuftelin carboxyl-terminus. We have isolated and characterized a full-length mouse cDNA clone and a partial porcine cDNA clone that include the region of the proposed frame-shift. The mouse tuftelin clone is 2572 nucleotides in length, exclusive of the poly(A+) tail. Translation from the 5'-most ATG yields a protein of 390 amino acids with an isotope-averaged molecular mass of 44.6 kDa and an isoelectric point of 5.9. Comparison of the bovine, mouse, and porcine cDNAs supports the revised bovine tuftelin amino acid sequence and suggests that the bovine tuftelin translation initiation codon be re-assigned to a more 5' ATG. Re-assigning the translation initiation codon lengthens the tuftelin protein by 52 amino acids, 51 of which are identical between bovine ...