cssi/SciSciGPT-SciSciNet huggingface dataset:
Interaction between parathyroid hormone and endogenous estrogen in normal women

It has been hypothesized that estrogens conserve bone substance by blocking the resorbing effect of parathyroid hormone (PTH). We evaluated this hypothesis by examining the relation of circulating PTH to endogenous estrogen fluctuation during four quarters of a single menstrual cycle in 20 normal women. The hypothesis predicts that PTH should vary directly with estrogen, since PTH should increase following estrogen elevation to satisfy physiologic demands for calcium. Contrary to the predicted direct variation, PTH remained constant throughout the menstrual cycle despite sharply fluctuating estrogen levels. Furthermore, PTH was negatively associated with estrone during the early follicular (r = -.65, P less than 0.005) and late follicular (r = -.84, P less than 0.0001) phases. We attempted to determine whether this unexpected relationship between estrone and PTH signified a direct physiologic link, by excluding factors which could have spuriously engendered the inverse correlation. Stepwise multiple regression and partial correlation showed that estrone contributed significantly to circulating PTH independent of the effects of dietary calcium, 25-hydroxyvitamin D, serum calcium, 1,25-dihydroxyvitamin D, phosphate, estradiol, progesterone, and body weight. Therefore, it is possible that the inverse correlation between estrone and PTH signified a direct physiologic link, as an artifactual cause for the relationship could not be identified. These data imply that estrone interacts with PTH, but not by blocking PTH-mediated bone resorption. We conclude that estrone is associated with reduced circulating PTH through an as yet undetermined mechanism.
Nonperturbative self-energy corrections to the Hubbard model

Abstract We have applied the functional derivative technique to the Hubbard model to obtain exact self-energy equations. An important feature is that these equations involve functional derivatives to first order only. A procedure is proposed for generating nonperturbative self-energy corrections systematically. A first approximation is applied to a 1-dimensional tractible system to demonstrate the validity of the approach. We calculate the ground state energy and compare the reasults to other approaches.
Comparing Adult Males and Females in the United States to Examine the Association between Body Mass Index and Frequent Mental Distress: An Analysis of Data from BRFSS 2011.

Background. There is conflicting evidence regarding the association of body mass index (BMI) with mental distress. Studies have focused on different dimensions of mental health and used different definitions and many of them have not controlled for confounding factors. The aim of this study was to examine the relationship between frequent mental distress (FMD) and BMI among adults in the United States, with special emphasis on gender differences. Methods. Data from the Behavioral Risk Factor Surveillance System (BRFSS) for the year 2011 were used in logistic regression models to predict FMD, defined as having 14 or more days of poor mental health in the previous month. Sociodemographic factors, tobacco and alcohol use, diet and physical activity, and number of chronic diseases were controlled for. Results. 11.95% ( <path id="x1D45B" d="M495 86q-46 -47 -87 -72.5t-63 -25.5q-43 0 -16 107l49 210q7 34 8 50.5t-3 21t-13 4.5q-35 0 -109.5 -72.5t-115.5 -140.5q-21 -75 -38 -159q-50 -10 -76 -21l-6 8l84 340q8 35 -4 35q-17 0 -67 -46l-15 26q44 44 85.5 70.5t64.5 26.5q35 0 10 -103l-24 -98h2 q42 56 97 103.5t96 71.5q46 26 74 26q9 0 16 -2.5t14 -11.5t9.5 -24.5t-1 -44t-13.5 -68.5q-30 -117 -47 -200q-4 -19 -3.5 -25t6.5 -6q21 0 70 48z" /> = 53,715) of the participants with valid responses ( = 496,702) had FMD. The adjusted ORs of having FMD among underweight, overweight, and obese females were 1.13 (95% CI: 1.10, 1.60), 1.10 (95% CI: 1.03, 1.19), and 1.21 (95% CI: 1.13, 1.31), respectively, but they were not statistically significant for males. Conclusions. These findings suggest a relationship between BMI and FMD, independent of other variables. It may be useful to explore longitudinal trend in this association.
Calcium-dependent and calcium-independent contractions in smooth muscles

This review examines signal transduction pathways mediating agonist-induced contraction of circular muscle in the body of the esophagus and in the lower esophageal sphincter (LES). In the LES, circular muscle agonists activate a well-defined contractile pathway, involving calcium (Ca(2+))-induced activation of calmodulin and myosin kinase, causing phosphorylation of 20-kDa myosin light chains (MLCs) and contraction. In this pathway, phosphorylation and contraction may be modulated by other factors, resulting, for instance, in inhibition of phosphatase activity, which may potentiate MLC phosphorylation. The agonist-activated contractile pathway of circular muscle from the esophageal body is not as well defined, and it is different from the LES contractile pathway, as it depends on activation of a Ca(2+)-independent protein kinase C (PKC), PKC-epsilon. In this pathway, agonist-induced Ca(2+) influx and/or release activate phospholipases to produce second messengers, such as diacylglycerol and arachidonic acid. The second messengers, however, activate a PKC-epsilon and a contractile pathway, which is Ca(2+) independent. This contractile pathway depends on activation of the mitogen-activated protein (MAP) kinases ERK1 and ERK2 and of p38 MAP kinase. These kinases are, in turn, linked to the small heat-shock protein HSP27, to integrin-linked kinase, and perhaps to other Ca(2+)-independent kinases, such as zipper kinase capable of producing MLC phosphorylation and contraction.
Uterine contraction pressures in women undergoing a trial of labor after prior cesarean delivery

A TRIAL OF LABOR AFTER PRIOR CESAREAN DELIVERY LINDA FONSECA, SUSAN RAMIN, MICHAEL LUCAS, ALFRED SOSA, MARYCLARE DAY, LARRY GILSTRAP III, University of Texas Health Science Center at Houston, Obstetrics, Gynecology and Reproductive Sciences, Houston, TX OBJECTIVE: To evaluate the maximum uterine contraction pressures or Montevideo units (MVUs) in womenundergoing a trial of labor (TOL) after one prior cesarean. STUDY DESIGN:TheMVUs were determined during the first stage of labor for women undergoing a TOL after one prior cesarean delivery. All women included in this study were at term, had intrauterine pressure catheters (IUPCs), and were undergoing TOL during their second pregnancy. For analysis of MVUs, patients were divided into two groups. Group A included those women who had a successful TOL. Group B included those women who required repeat cesarean delivery. MVUs were also determined according to the type of labor (spontaneous, induced, or augmented). RESULTS: The mean MVU ( ± SD) for group A (n = 98) was 217 ± 79 versus 214 ± 78 for groupB (n = 45) (P = NS). 72 (73.5%) of the 98 womenwho had successful TOL (group A) achieved$200 MVUs, compared to 27 (60%) of the 45 women who had a failed TOL (group B; P = NS). The MVUs achieved in both group A and group B were similar regardless of whether labor was spontaneous (202 ± 90 [n = 55] vs 202 ± 80 [n = 13]) or if oxytocin was required (234 ± 74 [n = 43] vs 219 ± 74 [n = 32], P = NS) for either induction or augmentation. Not surprisingly, the mean birth weight for babies in group B was significantly greater than for group A (3630 ± 460 vs 3410 ± 498, P = 0.015). The mean gestational age was similar for both groups (39.5 weeks vs 40.0 weeks). CONCLUSION: Themajority of women undergoing a TOL in their second pregnancy achieved $200 MVUs regardless of whether they had a successful vaginal birth or required a repeat cesarean delivery. The number of Montevideo units achieved was not predictive of success or failure of the TOL. Women requiring repeat cesarean delivery had larger babies.
La0.9Sr0.1Ga0.8Mg0.2O3 − δ-La0.6Sr0.4Co0.2Fe0.8O3 − θ composite cathodes for intermediate-temperature solid oxide fuel cells

Abstract Solid oxide fuel cells with thin La 0.9 Sr 0.1 Ga 0.8 Mg 0.1 O 3 − δ (LSGM) electrolytes have the potential to provide high power densities down to at least 600 °C. The present study was on a candidate cathode material for such SOFCs: composites containing La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 − θ (LSCF) and LSGM. Symmetrical cathodes with LSCF contents of 30–70 wt.% were fired at temperatures from 1000 to 1300 °C on both sides of bulk LSGM electrolytes. No secondary phases were detected by X-ray diffraction for the firing temperatures tested. Cathode polarization resistance R p , measured using impedance spectroscopy, varied little with firing temperature despite substantial changes in cathode microstructure as observed by scanning electron microscopy. R p varied only slightly with LSCF content, reaching a minimum of ∼ 0.18 Ohm.cm 2 at 650 °C for 40–60 wt.% LSCF fired at 1100 °C. The R p value was stable over several hundred hours at a current density of 0.5 A/cm 2 . The temperature dependence of R p yielded an activation energy of ≈ 1.7 eV for all compositions. Measurements versus oxygen partial pressure P O yielded R p ∝ P O2 0.20 . SOFCs with LSCF-LSGM cathodes and thin LSGM electrolytes yielded a maximum power density of 0.57 W/cm 2 at 650 °C.
A novel mechanism for CCR4 in the regulation of macrophage activation in bleomycin-induced pulmonary fibrosis.

Macrophage polarization into M1 or M2 phenotypes dictates the nature, duration, and severity of an inflammatory response. The objective of this study was to examine the role of CC chemokine receptor 4 (CCR4) in macrophage polarization during pulmonary oxidative injury in wild-type [WT (CCR4 +/+ )] and CCR4-deficient (CCR4 −/− ) mice. Intrapulmonary administration of bleomycin sulfate provoked lethal inflammatory and fibrotic responses in WT (CCR4 +/+ ) mice, but such responses were absent in CCR4 −/− mice. Transcript and protein analyses of alveolar and bone marrow-derived macrophages showed that cells isolated from CCR4 −/− mice did not exhibit CCL17-dependent M1 activation in response to bleomycin. Instead, CCR4 −/− macrophages showed an M2 phenotype characterized by significantly elevated expression of arginase 1 and FIZZ1 (found in inflammatory zone 1), particularly during the peak of pulmonary inflammation. Compared with WT (CCR4 +/+ ) mice, CCR4 −/− mice exhibited a significant increase in the expression of the nonsignaling CC chemokine scavenging receptor D6 in whole lung samples and isolated macrophages. Thus, these results demonstrate that CCL17-dependent activation of CCR4 in macrophages plays a central role in free radical-induced pulmonary injury and repair.
Sorption mechanisms of zinc to calcium silicate hydrate: sorption and microscopic investigations.

Knowledge of the binding mechanisms of heavy metals to cement minerals is essential for the prediction of the long-term leachability of secondary building materials and cement-stabilized wastes containing heavy metals. In this study, the sorption of Zn(II) to calcium silicate hydrate (C-S-H(I)) in pre-equilibrated aqueous suspensions has been investigated as a function of time (up to 87 d), pH (11.7, 12.48, and 12.78) and Zn(II) concentration (4.8−4800 μM). Electron probe microanalysis (EPMA) was performed in order to determine where Zn(II) was bound. At high Zn(II) concentrations (>1000 μM), the precipitation of β2-Zn(OH)2 ( pH 12) was observed. Surface precipitation could not be discerned. At lower concentrations, it was found that the sorption process was initially very rapid with over 50% sorbed within 30 min but that the sorption continued more slowly to at least 87 d. The data could be interpreted in terms of the Freundlich isotherm up to a Si:Zn(II)sorb...
Computing orthogonal polynomials

A simple transformation for achieving orthogonal polynomials of any order is described in this article. This transformation, called the residual procedure, is easy to understand, easy to implement in existing programs, and applicable for polynomial regression models whose data are unequally spaced. This same procedure is used in obtaining coefficients for orthogonal contrasts in the analysis of variance. The simplicity of this procedure also makes it easily adaptable to spread-sheet and data base applications.
VARIATION IN FEMALE LIFE-HISTORY TRAITS AMONG ALASKAN POPULATIONS OF THE THREESPINE STICKLEBACK, GASTEROSTEUS ACULEATUS L. (PISCES : GASTEROSTEIDAE)

Life-history characteristics of female threespine stickleback (Gasterosteus aculeatus) were examined in 12 populations, 11 freshwater and one anadromous, within the Cook Inlet region of Alaska. Because this area has been deglaciated during the last 20 000 years, the freshwater populations are recently derived, probably independently, from the local marine or anadromous stickleback. Freshwater threespine stickleback have undergone considerable morphological evolution within this region, apparently in response to environmental factors including predatory regimes and environmental productivity. Our freshwater study populations were selected to sample this range of morphological variation in order to determine whether life-history traits and morphologies have followed similar evolutionary trajectories. Freshwater populations could be categorized generally into one of three ecomorphotypes: those inhabiting relatively productive lakes having one or more piscivorous fishes present, and in which the stickleback exhibit a fully developed pelvic girdle; those inhabiting low-calcium lakes that lack piscivorous fishes, and in which the pelvic structures are incomplete; those living in streams with piscivorous fishes, in which the stickleback have fully developed pelvic girdles. The anadromous population constituted a fourth ecomorphotype that lives in marine waters, and is robustly armored. The freshwater populations showed considerable variation in all life-history traits assessed, and this variation generally corresponded to our ecomorphological classifications. Nevertheless, within each ecomorphotype there was sufficient variation to suggest that morphological and life-history traits may not always respond in the same manner in response to the same selective regime.
Performance Comparison of Internal Reforming Against External Reforming in a SOFC, Gas Turbine Hybrid System

Solid Oxide Fuel Cell (SOFC) manufacturers are presently considering both internal and external reforming fuel cell designs. Generally, the endothermic reforming reaction and excess air through the cathode provide the cooling needed to remove waste heat from the fuel cell. Current information suggests that external reforming fuel cells will require a flow rate twice the amount necessary for internal reforming fuel cells. The increased airflow could negatively impact system performance. This paper compares the performance among various external reforming hybrid configurations and an internal reforming hybrid configuration. A system configuration is introduced that uses interstage external reforming. Results show that that the thermodynamic performance of an interstage reforming system is an improvement over a base-concept external approach, and may be slightly better than the hybrid with an internal reforming fuel cell.© 2003 ASME
Ab initio study on the thermochemistry of diphosphine (P2H4) and diphosphine radical cation (P2H+4)

Abstract The G2 calculated heat of formation of diphosphine, Δ H f298 (H 2 PPH 2 ) is 35.3 ± 8.3 kJ mol −1 . This is closer to the earlier experimental estimates of 20.9 ± 4.2 kJ mol −1 and 41.4 kJ mol −1 than to the ΔH f298 value of 69 kJ mol −1 given in the widely used compilation of Lias et al. The diphosphine radical cation, H 2 PPH + 2 ; has a non-planar C 2h ground state structure and its heat of formation of H 2 PPH + 2 ( Δ H f28 ) is 893.2 ± 2.0 kJ mol −1 . The adiabatic ionization energy of diphosphine, H 2 P-PH 2 , was calculated using G2 theory to be 8.87 eV.
Accurate approximation of time-varying matrices of linear differential systems

We consider the problem of the identification of the time-varying matrix A(t) of a linear m-dimensional differential system y′ = A(t)y. We develop an approximation An,k = ∑nj − 1 cj{Y(tk + τj) Y−1(tk) − I} to A(tk) for grid points tk = a + kh, k = 0,…, N using specified τj = θjh, 0 < θj < 1, j = 1, …, n, and show that for each tk, the L1 norm of the error matrix is O(hn). We demonstrate an efficient scheme for the evaluation of An,k and treat sample problems.
CD and EPR Structural Studies on the KCNE1 Protein in a Lipid Bilayer

KCNE1, also known as minK, is a membrane protein responsible for modulating the KCNQ1 voltage-gated potassium ion channel in the human heart. Previous in vivo electrophysiological studies have shown that KCNQ1 loses its functionality in the absence of KCNE1, showing that KCNE1 is an essential protein for proper heart function (Sanders et al., Biochemistry 2007 46:11459-11472). Though KCNE1 has been extensively studied in micelle detergent systems, little work has been done to study the protein in an actual lipid bilayer-membrane system. Our current research uses biophysical techniques such as circular dichrosim (CD) spectroscopy and electron paramagnetic resonance (EPR) spectroscopy to characterize and compare KCNE1 proteins in various micelle and lipid bilayer environments using both qualitative and quantitative methods. Our CD spectroscopy experiments have shown that KCNE1 undergoes a change in secondary structure when removed from a micelle environment and placed in a lipid bilayer. We have used EPR spectroscopy to show that the dynamic properties of KCNE1 also change when taken out of micelles and inserted into lipid bilayers. Calculations have been done to quantify these differences in the structural and dynamic properties observed for KCNE1 in micelles and lipid bilayers.
Dietary Linolenic Acid and Fasting Glucose and Insulin: The National Heart, Lung, and Blood Institute Family Heart Study

Objective: To assess whether dietary linolenic acid is associated with fasting insulin and glucose. Research Methods and Procedures: In a cross-sectional design, we studied 3993 non-diabetic participants of the National Heart, Lung, and Blood Institute Family Heart Study 25 to 93 years of age. Linolenic acid was assessed through a food frequency questionnaire, and laboratory data were obtained after at least a 12-hour fast. We used generalized linear models to calculate adjusted means of insulin and glucose across quartiles of dietary linolenic acid. Results: From the lowest to the highest sex-specific quartile of dietary linolenic acid, means ± standard error for logarithmic transformed fasting insulin were 4.06 ± 0.02 (reference), 4.09 ± 0.02, 4.13 ± 0.02, and 4.17 ± 0.02 pM, respectively (trend, p < 0.0001), after adjustment for age, sex, energy intake, waist-to-hip ratio, smoking, and high-density lipoprotein-cholesterol. When dietary linolenic acid was used as a continuous variable, the multivariable adjusted regression coefficient was 0.42 ± 0.08. There was no association between dietary linolenic acid and fasting glucose (trend p = 0.82). Discussion: Our data suggest that higher consumption of dietary linolenic acid is associated with higher plasma insulin, but not glucose levels, in non-diabetic subjects. Additional studies are needed to assess whether higher intake of linolenic acid results in an increased insulin secretion and improved glucose use in vivo.
The Situational Levers of Negotiating Flexibility

The effects of a number of situational variables on decisions to be flexible or inflexible were explored in a simulation of an international negotiation on the regulation of gases contributing to the depletion of the ozone layer. Four negotiating-stage scenarios were created, each consisting of a particular combination of variables arranged into three experimental conditions. The experiment was run with two international samples, one consisting of scientists, the other of diplomats from different countries. The hypothesized differences among the conditions were obtained for both samples. Using a pair-comparisons format, participants were asked to judge the relative importance of the variables, within stages, in producing flexibility. Analyses of these judgments revealed trajectories of factors leading to agreement or to stalemate for both samples. These results were also compared with those obtained from a meta-analysis of earlier experiments examining similar variables. The simulation results, based on c...
Sentinel lymph node identification for early-stage cervical cancer

This requires a cervical injection of 0.1–0.5 mci radiolabeled filtered Tc99 microsulfur colloid in 0.1–0.5 ml of solution. After a speculum exam is performed, this will be injected directly into the cervix using a Potocky needle (Cooper Surgical, Trumbull, CT) or a spinal needle into the 4 quadrants closest to the area of normal cervix/tumor interface. In patients who have undergone a prior cone biopsy, the injection is made into the bed of the cone. The injection is made into the stroma of the cervix. The radiolabeled injection is prepared by the nuclear medicine department, which will also dispose of the syringe and other materials. A preoperative lymphoscintigram is obtained after the injection by the nuclear medicine department. Two series of pictures are obtained—immediate “dynamic images” and subsequent “static images” to localize the nodes. The localizing scan will usually accompany the patient to the operating room (Fig. 1). The patient will spend approximately 1 h in the nuclear medicine department. Injection of the radioisotope may be performed 1 day prior to surgery or the morning of.
Environments of Mid-Cretaceous Saharan dinosaurs

Abstract Recent studies of the oceanic record suggest that the Earth was a global greenhouse during middle Cretaceous time. A review of topographic, sedimentary and biologic data pertaining to terrestrial mid-Cretaceous equatorial environments broadly supports the climatic inferences of marine studies. In particular, analyses of widely-occurring low latitude Saharan sediments support the Cretaceous greenhouse hypothesis. In comparison to marine ecosystems, terrestrial ecosystems respond more sensitively to atmospherically transported heat and nutrients because of the more tenuous presence of the hydrosphere on land. Indeed, the morphologies of terrestrial biota suggest that: (1) equatorial mid-Cretaceous climates were episodic rather than seasonal; (2) convective storms although infrequent were violent; and (3) a moist intertropical convergence zone was absent. Cretaceous atmospheric dynamics apparently differed importantly from those of the present. Circumstantial evidence suggests that (1) higher atmospheric carbon dioxide levels probably stimulated the emission of other greenhouse gases; and (2) higher humidity levels reduced diurnal temperature variations but impaired evaporative thermoregulatory mechanisms. That terrestrial ecosystems withstood greenhouse conditions in low latitudes as well as they did underscores the adaptability of terrestrial life. Analogies for future environmental stresses and responses, whether anthropogenic or resulting from other causes, might be found in the terrestrial record of the Cretaceous equatorial zone.
Thermodynamic constants of N-[tris(hydroxymethyl)methyl-3-amino]propanesulfonic acid (Taps) from the temperatures 278.15 K to 328.15 K

Abstract Values of the second thermodynamic dissociation constant pK2 of N-[tris(hydroxymethyl)methyl-3-amino]propanesulfonic acid (Taps) have been determined at twelve temperatures from 278.15 K to 328.15 K including 310.15 K by measurements of the electromotive-force for cells without liquid junction of the type: Pt|H2 (g, p∘ = 101.325 kPa)|Taps (m1), NaTapsate (m2), NaCl (m3)|AgCl|Ag, where m denotes molality. The pK2 values for the dissociation of Taps are represented by the equation: pK2 = 2969.61 · (K/T) – 17.05052 + 2.73697 · ln(T/K). The values of pK2 for Taps were found to be (8.502 ± 0.0007) at T = 298.15 K and (8.225 ± 0.0009) at T = 310.15 K, respectively, indicating thereby to be useful as buffer solutions for pH control in the region 7.4 to 8.5. The thermodynamic quantities, ΔG∘, ΔH∘, ΔS∘, and Δ C p ∘ dissociation process of Taps have been derived from the temperature coefficients of the pK2.
Exact results for a system of coupled electronic and nuclear spins

We study the properties of a system of coupled classical electronic spins, each of which interacts with a quantum nuclear spin via an isotropic hyperfine interaction. Results analogous to those of Mattis and Wolf are derived for the free energy and static correlation functions. Specializing to the case of a linear chain of Heisenberg electronic spins and classical nuclear spins, we calculate some second frequency moments. These exhibit interesting deviations from the uncoupled case and at $T=0$\ifmmode^\circ\else\textdegree\fi{}K are interpreted in terms of spin-wave theory.
Issues of Language and Ethnicity in the Postclassic Maya Codices

Researchers have long attributed the prehispanic Maya codices to a Yucatecan provenience, based on their style and on the occurrence of Yucatec words spelled phonetically in the glyphic texts. This interpretation has recently been challenged by two studies that demonstrate the presence of Ch’olan vocabulary and morphological features in the Dresden and Madrid codices, alongside the better known Yucatec spellings (Wald 1994, Lacadena 1997). The present study identifies the linguistic affiliation of lexical items in the codical texts (Yucatecan, Ch’olan, or indeterminate), and charts the distribution of Yucatecan and Ch’olan terms in the Madrid Codex as a means of identifying patterns of usage. Several models are examined to account for the linguistic diversity of the manuscript, including (a) possible bilingualism of scribes; (b) lexical borrowing; (c) errors introduced by copying; and (d) the likelihood that certain glyphs were logographic, and could have different values depending on the language being recorded. It is argued that the Madrid Codex was drafted by Yucatecan scribes who were influenced in various ways by Ch’olan speakers — a situation comparable to the use of Spanish loanwords in the Colonial Books of Chilam Balam.
An Experiment in Grading: A Dialog

Professor Wilbur Scott submitted to Dr. Harold Yuker, Director of the Center for the Study of Higher Education at Hofstra, a report on a grading experiment he had conducted in his literature course, "Narratives of the Western World." Yuker's response, sympathetic but critical, suggested the possible value of presenting the report to a larger audience, with such comments as Yuker chose to make. This jointly written article expresses two kinds of perception common in the academic world, and since the differences between them are unresolved, this mode of presentation allows the reader himself to enter the debate.
Low-temperature elastic-constant anomalies in Fe-Cr-Ni-Mn alloys

Abstract By measuring velocities of longitudinal and shear waves we determined accurately the temperature variation of elastic constants — Young modulus, shear modulus, bulk modulus, Poisson ratio — of a polycrystalline austenitic steel: Fe-5Cr-26Mn. Versus temperature, near 335 K, this alloy exhibits an anomalous elastic-constant transition. In similar alloys, a magnetic-susceptibility cusp occurs at the transition temperature, T c ,. The bulk modulus shows a maximum at a higher temperature. Below T c , the Poisson ratio behaves anomalously, increasing with decreasing temperature.
Evidence for hydrogen bonds in 1,2-dimethyl-3-propylimidazolium chloride and its chloroaluminate molten salts

The crystal structure of l,2-dimethyl-3-propylimidazoIium chloride (DMPICl) reveals the formation of hydrogen bonds between the ring, methyl, and methylene hydrogens and the chloride ion. Although the aromatic rings are found in stacks, aromatic-aromatic interactions are precluded by the 6.98 A distance between the rings. From IR and1HNMR spectroscopies, it is determined that only the hydrogen bonds between the ring hydrogens and the chloride ion persist in the room-temperature molten salts obtained from combining DMPIC1 with AlCl3.
Crossing international cultural boundaries in business using common contingency frameworks

This paper discusses situation-specific contingency processes used by managers and business educators in handling such (1) common cross-boundary links or frameworks and (2) significant cross-boundary differences — two seemingly divergent aspects of cross-cultural management situations. This paper is based on the authors' conducting business training programs (focusing mainly on free market planning and management and on advanced computer technologies) for Asian and Russian/Central European business managers and graduate business students. It is also based on their research work done while investigating investment opportunities and in consulting in these countries over the past seven years.
Electronic structure of ladder polysilane and related compounds

Abstract Electronic structures in the optimized geometries of polycyclotetrasilane, polycyclotetragermane and their alternating copolymer are studied theoretically using the one-dimensional tight-binding self-consistent-field crystal orbital (SCF-CO) method. These polymers have anti and syn ladder structures. The results show that anti -configurations are energetically favorable for these polymers and that anti -conformers have smaller bandgap values and greater σ-conjugation than syn -conformers.
Atypical Infective Endocarditis

Background: Although infective endocarditis has changed in the recent past as a result of microbiologic and risk factors, it continues to be clinically challenging. The disease is characterized by the formation of septic masses of platelets on the surfaces of heart valves. Several mechanisms can cause or contribute to the development of endocarditis. Although risk factors for infective endocarditis are well known, patients with atypical signs and symptoms continue to challenge us. Methods: We describe a case report of a patient admitted to our inpatient service with back pain and presumed pyelonephritis. A MEDLINE literature search was conducted, using the key words “endocarditis,” “back pain,” and “bacterial,” for the years 1986 to the present. Results and Conclusions: A 42-year-old woman with a history of intravenous drug abuse was admitted to the family practice service with back pain and pyelonephritis. She developed hypoxia and a new heart murmur and had continued fevers. Blood cultures drawn in the emergency department grew methicillin-resistant Staphylococcus aureus . A bone scan and magnetic resonance imaging led to the diagnosis of epidural abscess. What appeared to be a simple case of pyelonephritis with back pain became a case of infective endocarditis complicated by an epidural abscess.
Interplay between JPEG-2000 image coding and quality estimation

Image quality and utility estimators aspire to quantify the perceptual resemblance and the usefulness of a distorted image when compared to a reference natural image, respectively. Image-coders, such as JPEG-2000, traditionally aspire to allocate the available bits to maximize the perceptual resemblance of the compressed image when compared to a reference uncompressed natural image. Specifically, this can be accomplished by allocating the available bits to minimize the overall distortion, as computed by a given quality estimator. This paper applies five image quality and utility estimators, SSIM, VIF, MSE, NICE and GMSE, within a JPEG-2000 encoder for rate-distortion optimization to obtain new insights on how to improve JPEG-2000 image coding for quality and utility applications, as well as to improve the understanding about the quality and utility estimators used in this work. This work develops a rate-allocation algorithm for arbitrary quality and utility estimators within the Post- Compression Rate-Distortion Optimization (PCRD-opt) framework in JPEG-2000 image coding. Performance of the JPEG-2000 image coder when used with a variety of utility and quality estimators is then assessed. The estimators fall into two broad classes, magnitude-dependent (MSE, GMSE and NICE) and magnitudeindependent (SSIM and VIF). They further differ on their use of the low-frequency image content in computing their estimates. The impact of these computational differences is analyzed across a range of images and bit rates. In general, performance of the JPEG-2000 coder below 1.6 bits/pixel with any of these estimators is highly content dependent, with the most relevant content being the amount of texture in an image and whether the strongest gradients in an image correspond to the main contours of the scene. Above 1.6 bits/pixel, all estimators produce visually equivalent images. As a result, the MSE estimator provides the most consistent performance across all images, while specific estimators are expected to provide improved performance for images with suitable content.
Inner Core Structure of Hurricane Alicia from Airborne Doppler Radar Observations

Abstract Airborne Doppler radar measurements are used to determine the horizontal winds, vertical air motions, radar reflectivity and hydrometer fallspeeds over much of the inner-core region (within 40 km of the eye) of Hurricane Alicia (1983). The reconstructed flow field is more complete and detailed than any obtained previously. The data show both the primary (azimuthal) and secondary (radial-height) circulations. The primary circulation was characterized by an outward sloping maximum of tangential wind. The secondary circulation was characterized by a deep layer of radial inflow in the lower troposphere and a layer of intense outflow above 10 km altitude. The rising branch of the secondary circulation was located in the eyewall and sloped radially outward. Discrete convective-scale bubbles of more intense upward motion were superimposed on this mean rising current, and convective-scale downdrafts were located throughout and below the core of maximum precipitation in the eyewall. Precipitation particle...
Wide-tuning range, amplitude-locked test signal source for self-healing, mixed-signal electronic systems

An integrated wideband amplitude-locked test signal source for “self-healing” and built-in-self-test (BIST) of multiband mixed-signal system-on-a-chip solutions is demonstrated. To the authors' knowledge, this work achieves the widest reported tuning range per unit die area compared to the state-of-the-art. The signal generator spans frequencies ranging from X to K band while occupying only 0.329 mm2 of core die area. The oscillator core is based on a differential ring topology to achieve wide tuning capability. The amplitude-locked loop consists of a variable gain amplifier (VGA), a low power peak detector, and an opamp that doubles as a loop filter. The circuits were fabricated in a commercially-available 180 nm SiGe BiCMOS platform.
Two-Connected Augmentation Problems in Planar Graphs

Given a weighted undirected graph G and a subgraph S of G, we consider the problem of adding a minimum-weight set of edges of G to S so that the resulting subgraph satisfies specified (edge or vertex) connectivity requirements between pairs of nodes of S. This has important applications in upgrading telecommunication networks to be invulnerable to link or node failures. We give a polynomial algorithm for this problem when S is connected, nodes are required to be at most 2-connected, and G is planar. Applications to network design and multicommodity cut problems are also discussed.
Albumin-bound polyacrolein: implications for Alzheimer’s disease

Acrolein-modified proteins are markers of disorders such as Alzheimer's disease (AD). Acrolein (H2C=HC-CH=O), which can be produced by the oxidative properties of amyloid-beta (Abeta) peptide, localizes to areas immediately surrounding early Abeta aggregates. The focal production of acrolein would consequently yield localized high concentrations that may be susceptible to polymerization via basic latex polymer chemistry. Using albumin as our model we examined whether simple in vitro conditions may bring about higher order aggregates composed of polyacrolein. We observed that thin plastic-like fragments were formed following incubation of albumin in acrolein solutions from 5 to 500 mM in sodium phosphate buffers (pH 7.4). The layered plastic film stained for carbonyls and for amyloid (cross-beta structures) suggesting a polyacrolein-albumin colloidal mixture. Large structures (up to 2700 microm2) readily form under simple conditions. These observations suggest that polyacrolein latexes may potentially exist in biological tissues contributing to the pathogenesis of diseases such as AD.
Persistent annular erythema of infancy

Annular erythema of infancy is an uncommon, nonpruritic, figurate erythema that begins in the first year of life. Biopsy specimens reveal a perivascular and interstitial lymphocytic infiltrate with numerous eosinophils. The cause of the disorder is unknown, but a hypersensitivity response to unrecognized antigens is suspected. The disorder is self-limited, but may last for many months. In our patient the eruption continued 19 months after its onset.
Lacustrine ostracodes as hydrochemical indicators in lakes of the north-central United States

The modern ostracode distribution in lakes of the north-central United States shows how ostracode abundances are related to concentrations of major ions such as calcium, sulfate, and bicarbonate. These relationships are quantified for species living in lakes that range from fresh water (200 μS cm-1) to saline water (17 000 μS cm-1). Lakes located in the Minnesota forests have different ostracode assemblages and different water chemistry than lakes located on the prairie of North Dakota and South Dakota. These differences are attributed to differences in precipitation and rock-water interactions. Multivariate analyses of the ostracode and water chemistry data set indicate that different ostracode species are associated with different water types. For example, Limnocythere sappaensis and Heterocypris glaucus are found in bicarbonate-enriched sulfate-dominated waters, whereas Limnocythere staplini is found in bicarbonate-depleted sulfate-dominated waters. Candona ohioensis and Limnocythere itasca are found in fresh water, and Candona rawsoni is eurytopic and found in both bicarbonate-enriched and bicarbonate-depleted sulfate-dominated waters. Ostracodes can be used to identify changes in both ionic composition (solutes) and ionic concentration.
Ribosomal components required for binding protein S1 to the 30 S subunit of Escherichia coli.

Abstract 30 S subunits of Escherichia coli ribosomes washed with 3 m -NH 4 C1 lose proteins S2, S3, S9, S10, S14, S20 and S21, as well as their ability to bind S1 with high affinity (Laughrea and Moore, 1978). Binding activity is restored when the split proteins are added back to the protein-deficient cores. Here we show that, among the split proteins, S9 is by far the most effective in restoring S1 binding capability to 3 m -NH 4 Cl cores.
Optimal transformations and the spectral envelope for real-valued time series

Abstract The concept of a spectral envelope for exploring the periodic nature of real-valued time series is introduced. This concept follows naturally from the data-dependent approach proposed by Stoffer et al. (1993) for spectral analysis and scaling of categorical processes. Here, the notion of the spectral envelope is applied in the context of transformations of a time series, and a data-dependent approach for selecting optimal transformations is proposed. These transformations help emphasize periodicities that may exist in the real-valued process. The definition of the spectral envelope is also extended to include multivariate time series. Several examples are used to illustrate the application of this methodology and asymptotic properties of the procedure are established.
Gender role stereotypes in fine art: A content analysis of art history books

This paper reports findings from a content analysis of the gender role images in the works of Gothic, Renaissance, Baroque and Modern art in three major Western art history textbooks. Males were overrepresented as subjects; males and females were presented in stereotypic roles and activities; the Madonna and the idle nude were common female images; males were overrepresented in portraits. Fine art as presented in major art history books was found to embody the gender role stereotypes of the wider society.
Interactive videodisc to teach combat trauma life support

Training military physicians in trauma management is a dilemma in peacetime, since there are few opportunities to gain clinical experience within the military care system. This program provides experience in clinical decision making through case simulation. Five cases, of increasing difficulty, are presented in a single videodisc side. The program is implemented on a system based on the IBM PC, and is written in the C programming language. The program emphasizes clinical realism by providing many clinical options at each decision point, and by audiovisually depicting combat clinical care in very realistic ways. The user interface is flexible and, though complex, is easy to use; it is supported by a narrated, on-line tutorial.
Characterization of spontaneous termination of sustained ventricular tachycardia associated with coronary artery disease.

Abstract To characterize the change in cycle length and QRS morphology before spontaneous termination of sustained ventricular tachycardia (VT), electrocardiograms were recorded and VT cycle length measured for the periods 31 to 21 and 11 to 1 beats before termination in 55 episodes from 28 patients with coronary artery disease. Beats 31 to 21 were designated as a period of stable arrhythmia and served as a reference for changes occurring just before termination. Forty-four episodes of VT occurred in the setting of antiarrhythmic drug therapy; 11 episodes occurred in patients not treated with antiarrhythmic drugs. Variability in cycle length was indexed by the standard deviation of the mean cycle length and by the percentage of consecutive cycles varying by ≥ 40 ms (% ≥ 40 ms). There was greater variability just before termination (standard deviation of the mean cycle length, 25.8 ms; % ≥ 40 ms, 16.7%) than during the stable period (standard deviation of the mean cycle length, 8.5 ms; % ≥ 40 ms, 5.4%; p
Comparison of auroral electrojet indices in the Northern and Southern Hemispheres

[1] The auroral electrojet (AE) index is traditionally calculated from a set of about 10 to 13 ground magnetometer stations located around the typical northern auroral oval location. Similar coverage in the Southern Hemisphere does not exist, so the AE calculation has only been performed using Northern Hemisphere data. In the present paper, we use seven southern auroral region ground magnetometers as well as their conjugate Northern Hemisphere data to calculate conjugate AE indices during the Northern Hemisphere winter using the standard method. The correlation coefficient between the northern and southern AE indices for many of the intervals is above 0.7, but in one interval, it is close to 0. We compare our conjugate AE indices with the standard AE index and find a number of asymmetries because of station coverage gaps both in our conjugate indices and in interplanetary magnetic field (IMF) conditions. When the southern AE index is compared with the standard AE index, we find that for most intervals the correlation is less than 0.7, and in one interval, the correlation is about 0. The correlation between the conjugate northern AE index and the standard AE index is somewhat better, suggesting true interhemispheric asymmetries. The mean difference between the southern and northern AE indices is largest during southward IMF and for large values of IMF ∣By∣ (>5 nT). This is most likely due to the increased activity levels during southward IMF and the greater twisting of the magnetic field lines during strong IMF By. IMF Bx seems to have no effect on the interhemispheric differences of the AE index. The mean differences between the southern and conjugate northern H component are of the order of ∼35 nT, with the largest differences occurring in the midnight magnetic local time (MLT) sector. We suggest that these differences may be related to seasonal effects, ionospheric effects, and MLT effects.
Dose-rate dependence of radiation-induced metaphase delay

An equation relating radiation-induced metaphase delay to the dose-rate and duration of irradiation is obtained. The equation is derived from a model specifying the effects of radiation on the normal chromosome coiling process. The basic assumptions of the model are (1) that normal coiling proceeds by contractile protein acting on segements of a viscoelastic chromosomal fiber; (2) that radiation causes cross-linking of adjacent chromosomal fibers which hinders the coiling process.
Chronic Mycoplasma conjunctivitis in house finches: Host antibody response and M. gallisepticum VlhA expression

Previous studies have shown that house finch field isolates of Mycoplasma gallisepticum (MG) vary in virulence and ability to induce an antibody response. After experimental inoculation, MG causes persistent, severe disease in a subset of individuals. In this study, we further characterized MG infection using five field isolates, with an emphasis on chronically diseased birds. After experimental inoculation of house finches, MG load was measured by quantitative PCR and anti-MG antibody responses were measured by ELISAs. Birds with chronic disease had significantly higher pathogen loads and antibody responses than did birds without chronic disease. Using a monoclonal antibody (MAb86) specific for a variant of the MG VlhA adhesin and immunodominant surface protein, we show that VlhA expression differs among MG isolates in this study, and that in vivo VlhA changes occur in house finches infected with MG. Overall, our results suggest that chronic MG disease has a strong pathogen-mediated component.
Modeling Freckle Segregation with Mesh Adaptation

Modeling the formation of macroscopic segregation channels during directional solidification processes has important applications in the casting industry. Computations that consider thermosolutal convection involve different length scales ranging from the small solute boundary layer at the dendrite tips to the characteristic size of the casting. In general, numerical models of solidification in the presence of a developing mushy zone are computationally inefficient because of nonlinear transport in an anisotropic porous medium. In the current work, mesh adaptation with triangular finite elements is used in conjunction with an efficient fractional-step solver of the momentum equations to predict the occurrence of channel-type segregation defects or freckles. The triangulations are created dynamically using an unstructured grid generator and a refinement criterion that tracks the position of the channel segregates. The efficiency of mesh adaptation is illustrated with simulations showing channel formation and macrosegregation in directional solidification of a Pb–Sn alloy.
Subharmonic entrainment of a forced relaxation oscillator

Abstract Using a simplified model of a relaxation oscillator which exhibits the characteristic free response of intervals of slow decay separated by rapid jumps, we determine steady-state response to a harmonic forcing input and obtain regions in the parameter space where subharmonic entrainment occurs. The model relaxation oscillator consists of a one-dimensional flow with jump conditions and is motivated by earlier studies of the flow on the slow manifold of a piecewiselinear relaxation oscillator. The results are obtained by studying the dynamics of the phase mapping which describes how the forcing phase varies between jumps. Details of the phase mapping are obtained both analytically and by numerical integration of the governing flow. The results obtained regarding existence and stability of subharmonics bear strong qualitative resemblance to experimental observations of frequency demultiplication by van der Pol and van der Mark (1927) and to numerical investigations of the forced van der Pol oscillator by Flaherty and Hoppensteadt (1978).