cssi/SciSciGPT-SciSciNet huggingface dataset:
Demonstration of Insulin Receptors and Modulation of Alkaline Phosphatase Activity by Insulin in Rat Osteoblastic Cells

Osteoporosis is a known complication of diabetes mellitus, suggesting a role for insulin in bone homeostasis. We studied insulin receptors and insulin action in the osteoblast-like rat osteogenic sarcoma cell line ROS 17/2.8. These cells share many common features with the osteoblast, such as 1,25-dihydroxyvitamin D3 receptors, PTH receptors, and 1,25-dihydroxyvitamin D3-induced modulation of alkaline phosphatase activity and osteocalcin. Competition binding studies revealed high affinity insulin receptors, with an ED50 for insulin of 1 nM. The receptors were highly specific for insulin, with 60% inhibition of insulin binding by an antireceptor antibody, no competition by epidermal growth factor, and an ED50 of 300 nM for proinsulin. Steady state maximal insulin binding was obtained by 40 min at 37 C, and insulin degradation, as measured by trichloroacetic acid solubility, was 1%/h at 37 C. ROS cells readily internalized insulin, and under steady state binding conditions at 37 C, 56% of the cell-associated radioactivity consisted of intracellular material. Chloroquine (100 microM) inhibited intracellular processing of insulin, leading to a 300% increase in cell-associated insulin by 2 h (37 C). Photoaffinity labeling of the insulin receptor with the photosensitive analog of insulin, B2 (2-nitro-4-azidophenyl-acetyl)des-pheB1-insulin, followed by solubilization and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, revealed specific bands of 125K and 430K mol wt under reducing and nonreducing conditions, respectively. Thus, the structure of insulin receptors in ROS cells appears comparable to that of insulin receptors of known target tissues. Insulin action was also examined. Insulin did not stimulate [2-3H]deoxyglucose uptake or [1-14C]leucine incorporation into protein. In contrast, physiological concentrations of insulin inhibited alkaline phosphatase activity in nonconfluent cells. After exposure to insulin for 24 h, alkaline phosphatase activity was decreased compared to basal by 39.5% and 50% with 5 and 50 ng/ml insulin, respectively. In conclusion, ROS cells bind insulin to specific receptors that are similar to insulin receptors on other target tissues; receptors internalize insulin, which is then processed through a chloroquine-sensitive pathway; insulin does not affect membrane substrate transport; and insulin does inhibit the activity of an enzyme that is important in bone metabolism. ROS cells represent a model for studying insulin effects on bone.
Variations in birth weight within the normal range are related to visual orienting in infancy for boys but not for girls

Abstract Pooling across 27 experiments on visual orienting during early infancy generated a large sample of full-term infants with birth weights greater than 2500 g ( N =944). A weight-for-date measure was obtained separately for girls and for boys by residualizing birth weight on gestational age at birth. The proportion of trials with orienting toward a moving target increased directly with this weight-for-date measure for boys but not for girls in a linear regression with adjustments for gestational age at testing, birth order and visual stimulus parameters across experiments. The same relations held when raw birth weight was used as a predictor. For the 475 boys, the z -score of the orienting measure increased by 0.221 for each kilogram increase in birth weight corrected for gestational age (0.196 z -units per kilogram adjusted for covariates, 95% CI = 0.04–0.35 z -units per kg, P =0.014). The interaction of gender and birth weight in this association makes explanations based on confounding family social variables less tenable as explanations. This association primarily for boys is similar to recently reported associations between birth weight and IQ during childhood. Possible factors underlying this association such as prenatal nutrition are discussed.
Methane Gas Visualization Using Infrared Imaging System and Evaluation of Temperature Dependence of Methane Gas Emissivity

Infrared (IR) camera has been used widely in the industry to visualize gases that cannot be seen by the naked eye or a visual camera. The use of an infrared camera for gas imaging offers several advantages such as faster locating of gas leaks and easier understanding on how the gas travels and disperses. In addition, several types of infrared cameras have the capability to measure the temperature of target objects especially solid body objects. However, this facility has not been applied for measurement of gas temperature due to complex analysis on the physics of infrared imaging and some uncertainties related to the radiation heat transfer processes during temperature measurement that have not been well understood. The objective of this research is to make use of the infrared or thermal imaging system to provide a concise temperature distribution of a methane gas plume presented in the infrared image. However, the current technology in infrared imaging cannot provide the true temperature of a gas plume b...
Prolonged survival (74 years) in unoperated tetralogy of Fallot with associated mitral valve prolapse.

Abstract Prolonged survival in tetralogy of Fallot is rare. About 5% of patients without operative therapy 5% survive >25 years. Recently, we studied at necropsy a man with tetralogy of Fallot who survived 74 years without operation and at necropsy severe mitral valve prolapse also was present. A description of pertinent findings in him are described herein.
Detailed Microscopic Analysis of Self-interstitial Aggregation in Silicon. I. Direct Molecular Dynamics Simulations of Aggregation

A comprehensive atomistic study of self-interstitial aggregation in crystalline silicon is presented. Here, large-scale parallel molecular dynamics simulations are used to generate time-dependent views into the self-interstitial clustering process, which is important during post-implant damage annealing. The effects of temperature and pressure on the aggregation process are studied in detail and found to generate a variety of qualitatively different interstitial cluster morphologies and growth behavior. In particular, it is found that the self-interstitial aggregation process is strongly affected by hydrostatic pressure. {111}-oriented planar defects are found to be dominant under stress-free or compressive conditions while {113} rodlike and planar defects are preferred under tensile conditions. Moreover, the aggregation pathways for forming the different types of planar defect structures are found to be qualitatively different. In each case, the various cluster morphologies generated in the simulations are found to be in excellent agreement with structures previously predicted from electronic-structure calculations and observed experimentally by electron microscopy. Multiple empirical interatomic potential models were employed and found to generally provide similar results leading to a fairly consistent picture of self-interstitial aggregation. In a companion article, a detailed thermodynamic analysis of various cluster configurations is employed to probe the mechanistic origins of these observations.
Presence of κ-opioid tone at the onset of the ovulatory luteinizing hormone surge in the proestrous rat

Abstract A decrease in endogenous opioid peptide inhibitory tone on the afternoon of proestrus is one event underlying generation of the ovulatory luteinizing hormone (LH) surge. Whether this disinhibition involves a complete loss of opioid suppression at the time of the LH surge is controversial. The objective of the present study was to determine whether a total loss specifically of the κ-opioid inhibitory component suppressing LH secretion occurs on proestrus at the onset of the LH surge. Proestrous rats were infused intraventricularly with either artificial cerebrospinal fluid (aCSF) or aCSF containing nor-binaltorphimine (nor-BNI), a selective κ-opioid receptor antagonist, from 15:30 or 16:30 h (the approximate onset time of the spontaneous LH surge) to 18:50 h. The LH surge in rats treated with nor-BNI beginning at 15:30 h started 0.5 h earlier than the spontaneous surge in aCSF controls, and had significantly higher plasma LH levels from 16:30 to 17:30 h. Nor-BNI administration begun at 16:30 h also produced an LH surge with more elevated plasma LH levels at 17:30 and 18:00 h than in aCSF-treated controls. These results demonstrate that significant amounts of κ-opioid tone are still present during the hours when the LH surge is initiated. Thus, a complete loss of κ-opioid inhibition is not required for the onset of the LH surge on proestrus.
Framing teacher education: participation frameworks as resources for teacher learning

This article examines the role modes of participation play in pre-service teachers' learning – what it means to teach and to learn, and what it means to be a teacher and a student. In particular, it examines how a teacher educator's taking up some social positions and refusing to take up others serves to cultivate active engagement and inquiry about teaching, learning, and schooling among the pre-service teachers by providing them with opportunities to reinterpret the figured world of school.
On designing a low-power garbage collector for java embedded devices: a case study

This paper presents an energy consumption comparison between two well-known garbage collection algorithms---mark-sweep-compact and reference counting. Our goal is to evaluate the suitability of reference counting as an algorithm for memory-constrained Java embedded devices. We hypothesize that reference counting would be suitable because it has higher data locality, which should reduce the number of data-cache misses, and so reduce energy consumption. However, this benefit could be offset by the extra instructions required for each reference update, a basic requirement of reference counting. To test our hypothesis, we implement, into Sun's KVM, a hybrid scheme that combines a standard mark-sweep-compact collector and limited-field reference counting. Our hybrid scheme is then compared against the default KVM with only mark-sweep-compact. We investigate several performance metrics that contribute to the performance of the system, including number of garbage collections, instructions, level-1 instruction and data cache misses, and total energy consumption.Based on our observations, the hybrid scheme yields three important benefits: (a) the hybrid scheme reclaims most memory quickly, resulting in less mark-sweep garbage collection invocations, (b) the reduction in garbage collection improves cache locality and reduces the number of main memory accesses, and (c) the reduction in memory accesses ultimately results in lower energy consumption, since a memory access can be energy-intensive. Our results confirm our hypothesis, with the hybrid scheme requiring up to 59% less energy than the default KVM.
Collective excitations of nuclear matter for N ≠ Z

Abstract Assuming an energy gap between proton and neutron in nuclear matter, collective excitations of nuclear matter are investigated. Two kinds of collective excitation are found, with a relation between energy and momentum given by Δ(q) = η+q2/2m+…. A connection between the collective states and excited states of actual nuclei is shown. The damping of the collective states is also calculated.
Respiration of 14CO2 by intact animals of various species given l-[1-14C]fucose or d-[1-14C]arabinose☆

Abstract The production of 14CO2 from l -[1-14C]fucose and d -[1-14C]arabinose has been studied in five mammalian species. Cats, guinea pigs, mice, and rabbits respired about 22% of the label of l [1-14C]fucose or of d -[1-14C]arabinose within 6 h after intraperitoneal injection of the sugar. Rats respired only 1.5% of the l -fucose label and 5% of the d -arabinose label in the same time period. Liver homogenates from cat, guinea pig, and rabbit produced significantly more 14CO2 from l -[1-14C]fucose or d -[1-14C]arabinose than mouse or rat liver homogenates. Unlike those of the other species, guinea pig liver homogenates had very low l -fucose dehydrogenase activity. The results suggest that substantial catabolism of l -fucose and d -arabinose occurs in the tissues of some animal species. Investigators wishing to employ l -fucose as a tracer of glycoprotein metabolism must, therefore, ensure that the species that they employ does not metabolize l -fucose to products interfering with their studies.
Growth hormone-releasing factor (GRF) regulates expression of its own receptor

Recent studies have demonstrated that passive immunization of neonatal rats to GRF inhibited their somatic growth through the suppression of GH secretion. In this study, we investigated the changes in pituitary GRF receptor (GRFR) expression in GRF antibody (GRF-ab) treated rats. Neonatal rats were treated from day 1 to day 10 after birth with every other day sc injection of 50 microliters of normal rabbit serum (groups I: control & III) or rabbit serum containing GRF-ab (groups II & IV). In addition, groups III & IV received twice daily injection of recombinant human GH (0.4 microgram/kg, sc). The rats were sacrificed on day 11 and pituitaries were removed. The pituitary weights in all treatment groups were decreased compared to the control group (I). Total pituitary RNA was extracted and GRFR mRNA levels were determined by RNase protection assay. Receptor RNA levels were quantitated and normalized to an internal standard, glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The ratios of GRFR mRNA to GAPDH mRNA were significantly decreased to 49.6 +/- 4.9 (mean +/- SD), 73.0 +/- 8.7, 43.6 +/- 9.5% of control group I in the experimental groups II, III, and IV, respectively (P < 0.01). These data suggest that (1) suppression of GH secretion in GRF-ab treated animals was due, at least in part, to a decrease in GRFR expression, (2) GRF may be necessary for its own receptor expression, (3) exogenous administration of GH suppresses pituitary GRFR mRNA.
Brief Endotoxemia Markedly Increases Expression of Glut1 Glucose Transporter in Kupffer, Hepatic Endothelial and Parenchymal Cells

Expression of various glucose transporter isoforms was studied in hepatic cells from fasted rats 3h after an injection of E. coli LPS (1mg/kg bw., i.v.). Glucose transporter isoform content of plasma membranes from hepatic cells was determined by western blot analysis using polyclonal antibodies. The predominant glucose transporter isoform expressed in parenchymal cells was GLUT2. GLUTS-1 and -4 were also observed to be present; however, GLUT4 protein was expressed to a relatively minor extent. GLUT3 was not detectable. LPS injection resulted in a 50% decrease in GLUT2 while GLUT1 protein doubled. GLUT4 was not altered after LPS. In the plasma membranes of Kupffer and endothelial cells only the GLUT1 isoform was detected. LPS treatment resulted in a 7- and 4-fold increase in the GLUT1 protein content in these cells. These data indicate that the predominant glucose transporter of hepatic nonparenchymal cells is the GLUT1 isoform and its synthesis and/or membrane translocation is augmented in response to LPS. The observed alterations in the contents of glucose transporters indicate adaptive changes to endotoxemia in the glucose consuming and glucose producing populations of hepatic cells.
Characterization of Zn(II)·Deglycobleomycin A2 and Interaction with d(CGCTAGCG)2: Direct Evidence for Minor Groove Binding of the Bithiazole Moiety

Deglycobleomycin (dgBLM) binds to and degrades the self-complementary oligonucleotide d(CGCTAGCG)2 in a sequence-selective fashion. To characterize the binding interaction, a 1:1 complex of Zn(II)·dgBLM A2 with the DNA octanucleotide has been examined using two-dimensional NMR experiments and restrained molecular dynamics calculations. Critical elements of the mode of DNA interaction within two structural domains of Zn(II)·dgBLM A2 were fundamentally different than those observed previously for Zn(II)·BLM A2 (Manderville, R. A.; Ellena, J. F.; Hecht, S. M. J. Am. Chem. Soc. 1995, 117, 7891). A minor groove mode of binding by the bithiazole moiety is supported by the present study. Only slight upfield shifting of the bithiazole (Bit) protons Bit H5 and Bit H5‘ is observed, and the sequential intrastrand NOE connectivities are retained upon Zn(II)·dgBLM A2 binding. The orientation of the drug molecule in the complex is based on the finding of 16 intermolecular Zn(II)·dgBLM A2−DNA NOEs. The cationic C-substi...
Taking It to the Stacks: An Inventory Project at the University of Mississippi Libraries.

This article examines multiple inventory methods and findings from the inventory processes at the University of Mississippi Libraries. In an attempt to reduce user frustration from not being able to locate materials, the University of Mississippi Libraries conducted an inventory process beginning with a pilot inventory of a branch library and a sample inventory at the Main Library followed by full inventory of sections of the Main Library's one-million-plus collection. The benefits of inventories, including cost effective, efficient workflows, are discussed.
Small-Molecule CD4 Mimics Interact with a Highly Conserved Pocket on HIV-1 gp120

Human immunodeficiency virus (HIV-1) interaction with the primary receptor, CD4, induces conformational changes in the viral envelope glycoproteins that allow binding to the CCR5 second receptor and virus entry into the host cell. The small molecule NBD-556 mimics CD4 by binding the gp120 exterior envelope glycoprotein, moderately inhibiting virus entry into CD4-expressing target cells and enhancing CCR5 binding and virus entry into CCR5-expressing cells lacking CD4. Studies of NBD-556 analogs and gp120 mutants suggest that (1) NBD-556 binds within the Phe 43 cavity, a highly conserved, functionally important pocket formed as gp120 assumes the CD4-bound conformation; (2) the NBD-556 phenyl ring projects into the Phe 43 cavity; (3) enhancement of CD4-independent infection by NBD-556 requires the induction of conformational changes in gp120; and (4) increased affinity of NBD-556 analogs for gp120 improves antiviral potency during infection of CD4-expressing cells.
Buspirone as an antidote to venlafaxine-induced bruxism.

Received November 12, 1999; revised December 9, 1999; accepted May 5, 2000. From Ehrling Bergquist USAF Hospital, University of Nebraska Medical Center; Mayo Clinic, Rochester, Minnesota. Address correspondence and reprint requests to Dr. Jaffee, 55MDOS/SGOH, 2501 Capehart Road, Offutt AFB, NE 68113. Copyright 2000 The Academy of Psychosomatic Medicine. We offer what we believe to be the first case series of venlafaxine-induced bruxism. Although selective serotonin reuptake inhibitor (SSRI)-associated bruxism has been described in at least two case series, we found no cases in a search of the MEDLINE database (1966–present) that link bruxism and the antidepressant venlafaxine.
A jaw metastasis from the colon

Abstract A case of primary adenocarcinoma of the colon metastasizing to the mandible is presented. The clinical, radiographic, and histologic features, course, and outcome are included.
Energetics and dynamics of the reactions of O(3P) with dimethyl methylphosphonate and sarin.

Electronic structure and molecular dynamics calculations were performed on the reaction systems O(3P) + sarin and O(3P) + dimethyl methylphosphonate (DMMP), a sarin simulant. Transition state geometries, energies, and heats of reaction for the major reaction pathways were determined at several levels of theory, including AM1, B3LYP/6-311+G(d,p), and CBS-QB3. The major reaction pathways for both systems are similar and include H-atom abstraction, H-atom elimination, and methyl elimination, in rough order from low to high energy. The H-atom abstraction channels have fairly low barriers (∼10 kcal mol−1) and are close to thermoneutral, while the other channels have relatively high energy barriers (>40 kcal mol−1) and a wide range of reaction enthalpies. We have also found a two-step pathway leading to methyl elimination through O-atom attack on the phosphorus atom for DMMP and sarin. For sarin, the two-step methyl elimination pathway is significantly lower in energy than the single-step pathway. We also prese...
Marketing Ethics across Cultures: Decision-Making Guidelines and the Emergence of Dialogic Idealism:

This article extends the macromarketing literature by discussing the relevance of culture to marketing ethics and by proposing decision-making guidelines for multifaceted, cross-cultural contexts. ...
The skeptical technophile: iPad review.

When I joined the faculty of the Radiology Department in April 2011, part of my onboarding included a computer budget for my office. Since I had just finally consolidated my life onto a MacBook Air which came with me everywhere, I had no interest in an office desktop, even if the University was paying for it. In the spirit of scientific inquiry, I used some of the money to buy an iPad and let the rest lapse back into the University’s coffers. I had been skeptical of the iPad as a useful tool for radiologists, and now I could find out for myself in a hands-on way. Here is my 6-month report.
Spatiotemporal Step Patterns during Crystal Growth in a Transport-Controlled System

We aim at insight into the unsteady kinetics and the formation of spatiotemporal patterns of steps during the crystal growth in systems, in which the growth rate is controlled by the rate of supply...
Semiclassical quantization rules near separatrices

We derive semiclassical quantization equations with uniform estimate of the error term near unstable equilibria of the classical system for the one-dimensional Schrodinger operator.
Cooling, degassing and compaction of rhyolitic ash flow tuffs: a computational model

Previous models of degassing, cooling and compaction of rhyolitic ash flow deposits are combined in a single computational model that runs on a personal computer. The model applies to a broader range of initial and boundary conditions than Riehle's earlier model, which did not integrate heat and mass flux with compaction and which for compound units was limited to two deposits. Model temperatures and gas pressures compare well with simple measured examples. The results indicate that degassing of volatiles present at deposition occurs within days to a few weeks. Compaction occurs for weeks to two to three years unless halted by devitrification; near-emplacement temperatures can persist for tens of years in the interiors of thick deposits. Even modest rainfall significantly chills the upper parts of ash deposits, but compaction in simple cooling units ends before chilling by rainwater influences cooling of the interior of the sheet. Rainfall does, however, affect compaction at the boundaries of deposits in compound cooling units, because the influx of heat from the overlying unit is inadequate to overcome heat previously lost to vaporization of water. Three density profiles from the Matahina Ignimbrite, a compound cooling unit, are fairly well reproduced by the model despite complexities arising from numerous cooling breaks. Uncertainties in attempts to correlate in detail among the profiles may be the result of the non-uniform distribution of individual deposits. Regardless, it is inferred that model compaction is approximately valid. Thus the model should be of use in reconstructing the emplacement history of compound ash deposits, for inferring the depositional environments of ancient deposits and for assessing how long deposits of modern ash flows are capable of generating phreatic eruptions or secondary ash flows.
Traumatic retropharyngeal hematoma—A cause of acute airway obstruction☆

Blunt trauma causing a retropharyngeal hematoma without an associated cervical fracture is a relatively rare occurrence. This article presents the case of a patient with airway compromise from a retropharyngeal hematoma, and discusses the diagnosis, airway management, and treatment of this condition.
Nontidal Circulation and Mixing Processes in the Lower Potomac Estuary

An analysis of the vertical structure of nontidal longitudinal currents and salinity in a reach of the lower Potomac River Estuary suggests that values for vertical eddy viscosity and eddy diffusivity scale with water depth H, tidal current amplitude U and bulk Richardson number according to conventional empirical formulas. However, the constant which relates the vertical eddy coefficients under conditions of neutral stability to UH is found to be an order of magnitude less than that expected for tidal conditions. Analyses also suggest that the degree of enhancement of longitudinal dispersion by the shear effect associated with the nontidal currents is a strong function of bulk Richardson number.
On the use of the word 'epigenetic'.

Over the past few years we have seen an odd change, or extension, in the use of the word ‘epigenetic' when describing matters of gene regulation in eukaryotes. Although it may generally be that it is not worth arguing over definitions, this is true only insofar as the participants in the discussion know what each other means. I believe the altered use of the term carries baggage from the standard definition that can have misleading implications. Here I wish to probe our use of language in this way, and to show how such a discussion leads to some more general considerations concerning gene regulation.
Molecular Neuroanatomy's “Three Gs”: A Primer

New genetic technologies are transforming nervous system studies in mice, impacting fields from neural development to the neurobiology of disease. Alongside these methodological advances, new concepts are taking shape with respect to both vocabulary and form. Here we review aspects of both burgeoning areas. Presented are technologies which, by co-opting site-specific recombinase systems, enable select genes to be turned on or off in specific brain cells of otherwise undisturbed mouse embryos or adults. Manipulated genes can be endogenous loci or inserted transgenes encoding reporter, sensor, or effector molecules, making it now possible to assess not only gene function, but also cell function, origin, fate, connectivity, and behavioral output. From these methodological advances, a new form of molecular neuroscience is emerging that may be said to lean on the concepts of genetic access, genetic lineage, and genetic anatomy—the three "Gs"—much like a general education rests on the basics of reading, ‘riting, and ‘rithmetic.
Seasonality of reproduction in captive squirrel monkeys (Saimiri Sciureus).

Seasonality of reproduction is believed to be influenced by environmental factors such as humidity, temperature, and photoperiod. In primates, there has been much speculation about which environmental factors have the greatest influence on reproductive seasonality. To determine whether environmental factors affect seasonality of reproduction of squirrel monkeys in captivity, I used path analysis to compare number of births and matings per month with monkeys kept in indoor enclosures (maintained at optimal temperatures) and those kept in outdoor enclosures (exposed to the elements). Since a different pattern of seasonality was found to occur, I was able to test whether temperature, rainfall, or photoperiod could explain the temporal variation in reproduction. Squirrel monkeys raised in captivity displayed different patterns of seasonality of reproduction, depending on the conditions in which they are housed (, P<0.001; G = 28.10, P<0.001). Temperature seemed to have a large impact on number of births and matings per month (matings: path coefficient = 0.799; births: path coefficient = −1.315). Understanding what factors regulate reproduction for animals and how these factors affect reproduction differently in wild versus captive populations are important to conservation and management of species. Am. J. Primatol. 69:1001–1012, 2007. © 2007 Wiley-Liss, Inc.
Dynamic programming for the analysis of serial behaviors

Studies of breakdowns in music performance can provide rich information about the planning activities required for music performance, as well as offer significant advantages over studies of skilled performance in other domains (Palmer & van de Sande, 1993). Yet despite the potential benefits, documented evidence of errors in music performance is scarce, primarily because of methodological limitations. One important practical problem that arises is how to find a correspondence between the actual performance and the score, or intended performance. When performances are long and complex, with potentially many errors, matching a performance to a musical score becomes a nontrivial task. This paper describes an algorithm for this task, developed in the context of a study of music production errors. The solution to the problem utilizes dynamic programming techniques and runs in polynomial time.
Chaotic Wave Solutions in a Nonlocal Model for Media With Vibrating Inclusions

The present paper is devoted to the investigation of wave solutions of a mathematical model of a complex medium that takes into account the nonlocal interaction of structural elements of the main medium and the vibration dynamics of an additional continuum (inclusions). By the methods of qualitative and numerical analysis, it is shown that an autonomous dynamic system with four-dimensional phase space has periodic, multiperiodic, quasiperiodic, and chaotic solutions. We construct bifurcation diagrams of the development of vibrations depending on the parameters of nonlocality of the dynamic equation of state of the medium
Hydrocarbon Oxidation by Bis-μ-oxo Manganese Dimers: Electron Transfer, Hydride Transfer, and Hydrogen Atom Transfer Mechanisms

Described here are oxidations of alkylaromatic compounds by dimanganese μ-oxo and μ-hydroxo dimers [(phen)2MnIV(μ-O)2MnIV(phen)2]4+ ([Mn2(O)2]4+), [(phen)2MnIV(μ-O)2MnIII(phen)2]3+ ([Mn2(O)2]3+), and [(phen)2MnIII(μ-O)(μ-OH)MnIII(phen)2]3+ ([Mn2(O)(OH)]3+). Dihydroanthracene, xanthene, and fluorene are oxidized by [Mn2(O)2]3+ to give anthracene, bixanthenyl, and bifluorenyl, respectively. The manganese product is the bis(hydroxide) dimer, [(phen)2MnIII(μ-OH)2MnII(phen)2]3+ ([Mn2(OH)2]3+). Global analysis of the UV/vis spectral kinetic data shows a consecutive reaction with buildup and decay of [Mn2(O)(OH)]3+ as an intermediate. The kinetics and products indicate a mechanism of hydrogen atom transfers from the substrates to oxo groups of [Mn2(O)2]3+ and [Mn2(O)(OH)]3+. [Mn2(O)2]4+ is a much stronger oxidant, converting toluene to tolyl-phenylmethanes and naphthalene to binaphthyl. Kinetic and mechanistic data indicate a mechanism of initial preequilibrium electron transfer for p-methoxytoluene and naphthal...
An Attempt to Detect the Artificial Production of V 0 -particles by High-Energy Photons

The beam of γ -rays produced by the large betatron built in Urbana by D. Kerst and his collaborators has been used to investigate the possibility of producing V -particles artificially, γ -rays produced on a metal target (see figure 47) were collimated by a suitable arrangement of lead screens to define a beam having an annular cross-section. The intensity of the γ -rays was 7000 R min-1 at a distance of 1 m from the source, corresponding to 1.14 x 1011 quanta cm-2 min-1.
Cephalosporin side chain idiosyncrasies: a case report of ceftriaxone-induced agranulocytosis and review of literature.

Drug-induced neutropenia is characterized by a sharp decrease in the absolute neutrophil count (ANC) to <500/mm3; agranulocytosis is said to be present once the granulocyte count reaches zero. Although associated with a large variety of drugs, this adverse effect is rare, occurring in 2.4–15.4 cases per million courses of therapy [1]. Because of its efficacy and relative safety, ceftriaxone is commonly used for treating a broad range of serious infections [2]. In this report, we describe a patient who developed agranulocytosis during treatment with ceftriaxone and recovered after treatment was changed to cefepime, and we review previously reported cases of ceftriaxone-induced agranulocytosis.
CHEMISORPTION PROPERTIES AND STRUCTURAL EVOLUTION OF PT-SI INTERMETALLIC THIN FILMS PREPARED BY THE ACTIVATED ADSORPTION OF SIH4 ON PT(111)

The reaction of a silicon adlayer deposited on Pt(111) by chemical vapor deposition (CVD) using silane (SiH4) is described. Data from Auger electron spectroscopy (AES) reveal that Si readily diffuses into the Pt substrate and sequentially forms at least two unique intermetallic Pt−Si surface structural phases with (√7 × √7)R19.1° and (√19 × √19)R23.4° real space unit cells as characterized by low-energy electron diffraction (LEED). The chemisorption properties of each of the ordered overlayers were studied using CO as a molecular probe. Reflection−absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) studies indicated that CO was mostly limited to chemisorption at “atop” Pt sites in the √7 phase with a significant reduction of the heat of adsorption with respect to the Pt(111) surface. The √19 phase also showed a significant modification of the chemisorption properties although it is not as pronounced as that seen for the √7 structure. The relevance of these studies to inter...
Investigating the Interaction of Saposin C with POPS and POPC Phospholipids: A Solid-State NMR Spectroscopic Study

The interaction of Saposin C (Sap C) with negatively charged phospholipids such as phosphatidylserine (PS) is essential for its biological function. In this study, Sap C (initially protonated in a weak acid) was inserted into multilamellar vesicles (MLVs) consisting of either 1-palmitoyl-2-oleoyl-sn-glycero-3-[phospho-L-serine] (negatively charged, POPS) or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (neutrally charged, POPC). The MLVs were then investigated using solid-state NMR spectroscopy under neutral pH (7.0) conditions. The 2H and 31P solid-state NMR spectroscopic data of Sap C-POPS and Sap C-POPC MLVs (prepared under the same conditions) were compared using the 2H order parameter profiles of the POPC-d31 or POPS-d31 acyl chains as well as the 31P chemical shift anisotropy width and 31P T1 relaxation times of the phospholipids headgroups. All those solid-state NMR spectroscopic approaches indicate that protonated Sap C disturbs the POPS bilayers and not the POPC lipid bilayers. These observations suggest for the first time that protonated Sap C inserts into PS bilayers and forms a stable complex with the lipids even after resuspension under neutral buffer conditions. Additionally, 31P solid-state NMR spectroscopic studies of mechanically oriented phospholipids on glass plates were conducted and perturbation effect of Sap C on both POPS and POPC bilayers was compared. Unlike POPC bilayers, the data indicates that protonated Sap C (initially protonated in a weak acid) was unable to produce well-oriented POPS bilayers on glass plates at neutral pH. Conversely, unprotonated Sap C (initially dissolved in a neutral buffer) did not interact significantly with POPS phospholipids allowing them to produce well-oriented bilayers at neutral pH.
Optimal wavelet design via multiresolutional parametric spectral estimation

Due to the fact that linearly dependent wavelet transforms are inefficient in computation and storage, the most popular discrete wavelet transforms (DWT) use orthonormal basis decompositions (ODWT). However, there are several problems related to ODWT: as a time- frequency analyzer, the time-frequency resolution and localization of ODWT are poor; from a spectral analysis point of view, the ODWT produces a distorted spectrum with energy leaking, aliasing, and magnitude distortion; to produce a reasonable time-varying spectrum, the signal is required to be octave-distributed with a spectral shape matching the spectra of the wavelets. To overcome these problems, a new approach for designing the optimal wavelet is proposed. Using the multiresolution parametric spectral estimator, the new method continuously tracks the time-varying signal to adapt the optimal wavelets, and yields high resolution, localization, and fidelity for the resulting time-frequency decomposition. When the optimal wavelets act as matched filters they can greatly reduce broadband background noise in the decomposition process.
The Influence of Top Management Team Leadership on Corporate Refocusing: A Theoretical Framework

Refocusing has become one of the major strategies pursued by large organizations in the 1990s. Prior research in the area of upper echelons (top management team) leadership has revealed that there is a strong relationship between top management team characteristics and organizational strategies and outcomes. However, researchers have confined their studies to exploring the impact of observable upper echelon characteristics, namely the demographic traits on corporate strategies and performance. In this study we integrate two main sets of upper echelon leadership characteristics, demographic and psychological traits, and build a theoretical framework to study their impact on corporate refocusing.
Analytical model for optically generated currents in GaAs MESFETs

The MESFET as an optically sensitive microwave element in MMICs has attracted much attention. The theoretical modeling of the device, however, needs more consideration. The authors propose an analytical model for the illuminated MESFET, complete in that all major contributions to the optical response are considered. The dependence of the response on bias conditions, the wavelength and intensity of the optical input, and the particulars of device structure, are incorporated in the model. The importance of the internal photovoltaic effect, which has not been properly modeled previously, is emphasized. The novel theoretical model is verified by experimental results. >
Empathy and care within engineering: qualitative perspectives from engineering faculty and practicing engineers

The purpose of this study was to investigate how empathy and care look within an engineering context from the perspective of (1) existing literature (2) engineering faculty and (3) practicing engineers. The project employed three separate, but interrelated studies, including a summative content analysis of the existing literature, a consensual qualitative research analysis of small group interviews with the engineering faculty, and a consensual qualitative research analysis of written responses from practicing engineers to an open-ended question about empathy and care. Thematic analyses of all three studies demonstrated that although empathy and care appear to have a place within engineering and engineering education – particularly given the current trends in engineering towards sustainability, team-oriented design work, and the renaissance engineer of tomorrow – it appears that conversations and awareness of these two constructs may not often be explicitly stated within the literature or frequently addre...
A compact K/Ka-band transceiver MMIC using GaAs 3D-MMIC technology

A highly integrated K and Ka-band transceiver MMIC that integrates 33 circuits in a 3 mm × 3 mm area using three-dimensional MMIC (3D-MMIC) technology is presented. It achieved a noise figure of 3.4 dB and a conversion gain of 39 dB at 25 GHz in the receive mode. It also achieved a high P1dB of 8 dBm and a conversion gain of 29 dB at 25 GHz in the transmit mode. The power dissipation of the MMIC is only 0.34 W in the receive mode and 0.38 W in the transmit mode. It also integrates a frequency doubler, a single-pole/double-through (SPDT) amplifier for local oscillator (LO) signals, and step attenuators with built-in inverters using N-channel depression HEMTs. The attenuators make it possible to control receiver gain and transmitting power, and thermal noise reduction to the receiver block.
Ovine Osteopontin: II. Osteopontin and αvβ3 Integrin Expression in the Uterus and Conceptus During the Periimplantation Period

Osteopontin (OPN) is an acidic 70-kDa glycoprotein that is cleaved by proteases to yield 45-kDa and 24-kDa fragments. The 70-kDa and 45-kDa proteins contain a Gly-Arg-Gly-Asp-Ser (GRGDS) sequence that binds to cell surface integrins (primarily alpha(v)beta(3) heterodimer) to promote cell-cell attachment and cell spreading. A 70-kDa acidic protein was previously detected by two-dimensional (2D) PAGE in Day 17 pregnant endometrial cytosolic extracts using Stainsall and identified as immunoreactive OPN using Western blotting. Three forms of immunoreactive OPN proteins (70, 45, and 24 kDa) were detected by 1D PAGE and Western blot analysis of endometrial extracts. OPN protein in endometrial extracts did not differ between cyclic and pregnant ewes. However, the amount of 45-kDa OPN increased in uterine flushings from pregnant ewes between Days 11 and 17. Immunoreactive OPN was localized to luminal and glandular epithelia of both cyclic and pregnant ewes, and to trophectoderm of Day 19 conceptuses. The alpha(v) and beta(3) integrins were detected on Day 19 endometrium and conceptuses by immunofluorescence. It was reported that OPN mRNA increases in the uterine glands of pregnant ewes and secretion of OPN protein into the uterine lumen increases during early pregnancy. The present results demonstrate accumulation of OPN protein on endometrial LE and conceptus trophectoderm. Therefore, it is hypothesized that progesterone and/or interferon-tau induce expression, secretion and/or proteolytic cleavage of OPN by uterine epithelium. Secreted OPN is then available as ligand for alpha(v)beta(3) integrin heterodimer on trophectoderm and uterus to 1) stimulate changes in morphology of conceptus trophectoderm and 2) induce adhesion between luminal epithelium and trophectoderm essential for implantation and placentation.
An Investigation of the Implementation and Effects of a Full-Time Mainstreaming Program

Results are reported from an investigation of the feasibility and effectiveness of the Adaptive Learning Environments Model, a program designed to provide special education services for mainstreamed handicapped students in regular classroom settings on a full-time basis. Three categories of findings are discussed—degree of implementation, classroom processes, and student achievement and attitudinal outcomes. In addition, the objectives and design of the educational program are described, and the educational and policy implications of the findings are discussed.
Hydrogen structures in heavily hydrogenated crystalline and amorphous silicon

The hydrogen binding energy distribution and IR spectra of hydrogen platelets in c-Si have been measured and compared to H in other forms of silicon including hydrogenated polycrystalline and amorphous Si. The binding distribution for platelet containing samples, determined using H evolution, exhibits two peaks: a bulk peak at 1.8--1.9 eV below the transport barrier, and a second possibly surface related peak 1.8--1.9 eV below the surface evolution barrier. The bulk peak grows at 250 C and is consistent with calculated energies for platelet structures. The same two evolution peaks are found in hydrogenated polycrystalline Si and amorphous silicon. The IR spectra for heavily hydrogenated c-Si are dominated by the stretching modes at 2076 and 2128 cm{sup {minus}1}. Most surprisingly there appears to be a strong mode at 856 cm{sup {minus}1} which is associated with a deformation mode of SiH{sub 3}. Even more surprising, this SiH{sub 3} 856 cm{sup {minus}1} mode remains until 550 C indicating that the SiH{sub 3} containing structures are rather stable.
FRACTURE MECHANICS TREATMENT OF RESIDUAL STRESSES IN DEFECT ASSESSMENT

Over the last decade, as more in-depth understanding of weld residual stresses is being achieved, particularly of their characteristic distributions in pressure vessel and piping components, the residual stress effects on stress intensities at welds are becoming better understood. In this paper, some of the important residual stress characteristics are first identified in the form of either “bending” dominated or “self-equilibrating” dominated types for girth welds. The applicability in other joint configurations in welded structures is then discussed, with a collection of validated residual stress distributions. The characterization of both “bending” and “self-equilibrating” types in residual stress distributions provides a consistent framework for stress intensity factor considerations in either fracture and fatigue assessment. The contribution of weld residual stresses to stress intensities at welds are shown to be in the form of Ksolutions under displacement controlled conditions. The “bending” type residual stresses provide a longer range of influence than “self-equilibrating” type in K solutions. The contribution of “self-equilibrating” type residual stresses to stress intensities is shown to be dominant when crack size is small, while the contribution of the “bending” type dominant for crack size up to a much larger size with respect to wall thickness.
Carcinogenesis, Bioassays, and the Regulatory Modus Operandi

The major provocative conjecture of Dr. Cohen’s article is contained in the subtitle: ‘‘The Two-Year Bioassay Is No Longer Necessary.’’ I truly wish that I could board this train; I cannot. Neither, however, do I wish to lay on the tracks to derail an attempt to shift from a tired toxicological paradigm: the two-year rodent carcinogen bioassay. The difficulty appears to be the need to accept Cohen’s specific mechanistic views of carcinogenesis for the alternative he suggests to be viable. Everyone would appreciate having at their disposal bioassays that could predict carcinogenesis, mechanisms included, using less time, labor, and treasure than expended by the currently employed two-year rodent models and their kin. Cohen’s proposal here for hepatocellular carcinogens is an approach that might go some distance in reaching that goal after some rethinking. Yet one disturbing exigency comes to mind that might present an impasse: how would quantitative risk assessment or potency ranking be gleaned from short-term studies? The biological unit of time for carcinogenesis is not celestial, but physiologic, best correlated with species life span. The rationale of the two-year rodent studies is that they employ the majority of life span without significant compromise of study viability, which can be thwarted for many reasons. Early nonneoplastic lesions are often considered to be indicators of the eclipse of the viable chronic dose. Moreover, carcinogenesis, per se, will not be adequately realized, either qualitatively or quantitatively, by studies employing only a small fraction of rodent lifetime. I am skeptical that employing early nonneoplastic lesions will give a valid quantitative measure of potency, which should be the primary regulatory parameter. There may also be other technical concerns with Cohen’s approach. They are likely to be with the experimental details and, most importantly, over reaching a consensus on utility. Balanced regulation, guided by risk assessment, is best based on the use of scientific models that have a reasonable level of consensus. To do other than this results in a degree of bickering not compatible with public confidence in science-based regulation. Moreover, one has only to view the history of the Interagency Coordinating Committee on the Validation of Alternative Methods and its international counterparts, European Centre for the Validation of Alternative Methods and the Japanese Center for the Validation of Alternative Methods, to know that it is not just an ephemeral premonition to worry that consensus about alternative models, such as the Cohen proposal, will be elusory. I have more general concerns with Cohen’s approach that I would like to air.
Lattice codes can achieve capacity on the AWGN channel

It is shown that lattice codes can achieve capacity on the additive white Gaussian noise channel. More precisely, for any rate R less than capacity and e>0, there exists a lattice code with rate no less than R and average error probability upper-bounded by e. These lattice codes include all points of the (translated) lattice within the spherical bounding region (not just the ones inside a thin spherical shell).