cssi/SciSciGPT-SciSciNet huggingface dataset:
Staging of Breast Cancer with Ultrasound

The prognosis of women with breast cancer depends on tumor size and regional lymph node status. Clinical assessment combined with imaging is important in the staging of primary breast cancer, particularly in a multidisciplinary setting where radiologists, pathologists, medical, surgical, and radiation oncologists work together to optimize patient care. Delineation of loco-regional (multifocal vs multicentric) disease is critical in surgical planning to enable a curative procedure with clear margins and good cosmetic outcome. Regional (ipsilateral axillary, infraclavicular, internal mammary, and supraclavicular) nodal information helps determine patient eligibility for neoadjuvant protocols and also aids in radiation planning. The role of high-resolution ultrasound in staging breast cancer is discussed in conjunction with mammography, and magnetic resonance imaging.
Subtleties in crystal structure solution from powder diffraction data using simulated annealing: ranitidine hydrochloride.

Recent advances in crystallographic computing and availability of high-resolution diffraction data have made it relatively easy to solve crystal structures from powders that would have traditionally required single crystal samples. The success of direct space methods depends heavily on starting with an accurate molecular model. In this paper we address the applicability of using these methods in finding subtleties such as disorder in the molecular conformation that might not be known a priori. We use ranitidine HCl as our test sample as it is known to have a conformational disorder from single crystal structural work. We redetermine the structure from powder data using simulated annealing and show that the conformational disorder is clearly revealed by this method.
An existence and uniqueness theorem for a nonlinear differential equation

for h . k # 0 and (x + h, y + k) in I. If u possesses a cross partial derivative, say D,,,u a-e. on 1, then Du(z) = D3cp(u) 9 a.e. on 1. It has been shown [2] that if U(Z) is anchored and absolutely continuous on I, then Du, D,,u, and D,,u exist and are equal a.e. on I. There are functions however, for which the derivative as defined above exists but a first partia1 derivative and hence a cross partial derivative fails to exist on 1. Thus the second order nonlinear partial differential equation D,,u(z) = f[x, u(z)] is a special case of equation (1). a.e. on I. (3)
Application of Interpolating Moving Least Squares Fitting to Hypervelocity Collision Dynamics: O(3P) + HCl†

We use an automated interpolating moving least-squares (IMLS) algorithm, which generates a fitted ab initio surface for systems of arbitrary topology, to construct a global OHCl ((3)A'') surface at the UB3LYP/aug-cc-pVTZ level of theory. This analytic PES includes all reaction channels and OHCl geometries with energies up to 144 kcal/mol (6.25 eV) above the O + HCl asymptote. The fitted surface was combined with the quasiclassical trajectory method to study the dynamics of the O((3)P) + HCl reaction at hyperthermal collision energies. The fitted PES greatly improves energy conservation during trajectory integration and eliminates problems with ab initio convergence, which are often encountered during direct dynamics studies. The more extensive trajectory calculations yield new insight into the title reaction and agree well with previous experimental studies and direct dynamics results.
Indomethacin administration at the time of ultrasound-indicated cerclage: is there an association with a reduction in spontaneous preterm birth?

Objective The purpose of this study was to estimate the effect of indomethacin on the prevention of preterm birth (PTB) in women with an ultrasound-indicated cerclage. Study Design We performed a retrospective cohort study from 1995-2006. Asymptomatic women with a cerclage for a short cervical length (CL), which was defined as Results Fifty-one women received indomethacin, and 50 women did not. There were no differences between groups regarding previous PTB, gestational age, or CL at time of cerclage. The rate of spontaneous PTB at Conclusion Administration of indomethacin around the time of ultrasound-indicated cerclage was not associated with a decrease in spontaneous PTB.
Fetal Blood Sampling and Intrauterine Transfusion

Fetal blood sampling via cordocentesis, alternatively called percutaneous umbilical blood sampling, has improved the accuracy of diagnosis of fetal disorders, including hydrops, neonatal alloimmune thrombocytopenia, and genetic diseases. The ability to access the fetal vasculature allows timely intrauterine treatment, most commonly red blood cell or platelet transfusions. Such interventions have led to improved survival of infants who would have otherwise died in utero, from prematurity, or from late complications of disease. Appropriate patient selection and identification, monitoring, timely intervention, and a team approach between the obstetrician, maternal–fetal medicine specialist, and neonatologist are key to optimizing outcomes.
Thermal transformations of 2-chlorophenol on a surface of ZnO powder catalyst

Abstract Catalytic transformation of multifunctional molecules requires understanding of the competing reactions on a surface of a heterogeneous catalyst. Here the reaction of 2-chlorophenol is investigated with ZnO powder that has a potential to be used in environmental remediation. Since it is important to follow every step of surface-catalyzed processes, adsorption and thermally induced transformations of 2-chlorophenol on ZnO powder catalyst were followed by Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), and supplemented by density functional theory (DFT) investigations. The room temperature adsorption FTIR results show that O–H dissociation is the primary reaction pathway. Room temperature adsorption studies followed by in situ thermal annealing to desired temperature and then quenching back to room temperature followed by XPS prove that C–Cl dissociation in 2-chlorophenol is competing with the O–H dissociation process on ZnO; however, the majority of chlorine is still bound to carbon and can only be removed by thermal annealing together with the phenyl group. DFT description helps to construct the reaction mechanism diagram and O–H dissociation is found to have a reaction barrier of only 62.4 kJ/mol, while C–Cl bond dissociation has a substantially higher barrier of 111.2 kJ/mol. Thus, this set of studies suggests that the reaction of 2-chlorophenol on ZnO powder proceeds selectively towards the O–H dissociation; however, the products released from its surface following thermal annealing contain chlorinated hydrocarbon fragments. This observation implies that it would be difficult to use unmodified ZnO as a catalyst for a direct utilization and mineralization of chlorophenols.
Single Molecule Study of HIV-1 Reverse Transcriptase Polymerization Activity in the Presence of NC

HIV-1 reverse transcriptase (RT) is a multifunctional polymerase, which synthesizes double-stranded proviral DNA from single-stranded viral RNA by catalyzing RNA- and DNA-dependent DNA polymerization and degrading RNA via its RNase H activity. Reverse transcription is an essential step in HIV-1 infection, and HIV-1 RT is the target of many anti-AIDs therapeutic drugs. HIV-1 nucleocapsid (NC) protein is a nucleic acid chaperone, which facilitates DNA duplex melting and re-annealing, and shows rapid protein-nucleic acid interaction kinetics. The effect of NC on the reverse transcription process is not fully understood. To gain insights into the polymerase activity of RT in the presence of NC protein, we use single molecule force spectroscopy to examine DNA polymerization activity of HIV-RT along long single-stranded DNA (ssDNA) templates with and without NC. Our preliminary observations show the polymerization activity of RT is dependent on the force on ssDNA templates; an increase in the force on ssDNA templates reduces the polymerization activity of HIV-RT. The observed exponential dependence of polymerization activity of RT with force on long ssDNA templates is consistent with previous single molecule studies, and NC appears to enhance the polymerization rate. Our studies will test the polymerization activity of RT in the presence of NC, allowing us to determine the biophysical mechanism by which NC enhances this activity.
Once-Daily Ceftriaxone in the Treatment of Lower Respiratory Tract Infections

We conducted a retrospective clinical evaluation to assess the efficacy of a 1-gram once-daily regimen of intravenously administered ceftriaxone in the treatment of a variety of bacterial infections. Of the 250 patients studied, 167 had infections of the lower respiratory tract, approximately 70% of which were diagnosed as community-acquired pneumonias. The principal identified pathogens were Staphylococcus aureus and Haemophilus influenzae. Forty per cent of community-acquired pneumonias occurred in patients over 69 years of age, who showed a 13% mortality compared to a mortality rate of 4% in younger patients. Once-daily ceftriaxone was effective and well tolerated as empiric therapy for pneumonia likely to be caused by susceptible organisms.
Stochastic response of structures with fluid-containing appendages

Abstract The influence of fluid-containing appendages on the dynamic response of multi-degree-of-freedom systems subjected to stochastic environmental loads, e.g., earthquakes, waves, or winds, is investigated. The modal properties of a system comprising of a fluid-containing appendage attached to a multi-degree-of-freedom system are expressed in terms of the individual dynamic properties of the primary and secondary systems. The primary system is modeled as a lumped mass multi-degree-of-freedom system. An equivalent lumped mass model of the sloshing fluid is used to represent the secondary system. All the frequencies of the secondary system that are less than or equal to the fundamental natural frequency of the primary system are included in the dynamic analysis of the combined system. The input to the system may be a stationary or a non-stationary white or filtered white noise vector-valued excitation. In this study the structural response to an earthquake represented by a non-stationary filtered white noise is computed at any time interval by utilizing the modal impulse-response function and approximating the envelope intensity function with a staircase unit impulse function. The formulation presented here renders the computational procedure very efficient by reducing the multiplicity of the integrals. The covariance matrices of the response components of the combined system are computed by using this formulation. The peak response values at any level on the structure may be obtained by following the evolutionary distribution of the extreme values. An important feature of the combined system is that the response of the primary system is suppressed when one of the sloshing modes of the secondary fluid appendage is tuned to the fundamental mode of the primary system. A building with a water tank situated at any floor, excited by an earthquake, is used to illustrate the methodology.
Punishment, placebos, psychophysiology, and polemics in aversion therapy: A reply to danaher and lichtenstein

Danaher and Lichtenstein's (1973) comments on aversion therapy are briefly evaluated. It is suggested that they underestimate the importance of conditions of original training relative to the modification of smoking behavior using the “rapid smoking” method, confound the issues of endogenous cues and topographial similarity, blur important distinctions among various kinds of placebo control groups, incorrectly imply that attention to the qualitative aspects of aversive stimuli necessitates a psychophysiological methodology, and erroneously evaluate the clinical utility of parametric studies. It is emphasized that most of these issues can be empirically resolved if investigators utilize more precise experimental designs.
Angular dependent transport of auroral electrons in the upper atmosphere

The transport of auroral electrons through the upper atmosphere is analyzed. The transport equation is solved using a discrete-ordinate method, including elastic and inelastic scattering of electrons (resulting in changes of pitch angle) and degradation in energy as the electrons penetrate into the atmosphere. The transport equation is solved numerically for the electron intensity as a function of altitude, pitch angle, and energy. In situ measurements of the pitch angle and energy distribution of precipitating electrons over an auroral arc provide boundary conditions for the calculation. Model calculations were carried out with various different phase functions for elastic and inelastic collisions to attempt changing the angular scattering, but the observed pitch angle distributions remain unexplained. It is suggested that mechanisms other than collisional scattering influence the angular distribution of auroral electrons at or below 300 km altitude in the low-energy domain.
The adaptive nature of the social system and behavior in the eastern chipmunk, Tamias striatus

1. The social system and behavior of a population of Tamias striatus were studied from October 1973 to November 1976 on a 5-ha woodlot in southeastern Ohio. The basic social unit is the solitary individual occupying a single burrow system, but a more complex social unit consisting of mother and litter persists briefly until emergence and dispersal of the litter from the natal burrow site. Burrow systems are distributed in a regular pattern and are surrounded by nonoverlapping core areas which are defended throughout the year by adults and seldom by subadults or juveniles. Defense of home sites has evolved as a mechanism to insure individuals an adequate share of a seasonal food supply. Two other spacing mechanisms occur in the annual cycle: defense of individual distances and relative dominance hierarchies. Rare instances of aggressive behavior in juveniles and subadults are examples of defense of individual distance. Relative dominance hierarchies form among adult males participating in a mating bout in core areas of estrous females. Brief pairing and multiple mating occur during a single mating bout. 2. Time budgets vary with sex and age class and also due to temporal, spatial, and social factors. The adaptiveness of differential time budgets resulting from the effects of these factors is discussed. Individual behavioral profiles are related to successful defense of home sites and reproductive fitness. Unaggressive adults are never or rarely territorial and do not mate, but extreme aggressiveness may be disadvantageous under certain circumstances. The ontogeny of aggressive behavior is discussed and factors selecting against precocious aggressiveness and sexual behavior are suggested. 3. The social system and behavior are major determinants of population dynamics and spatial distribution. Territoriality acts to regulate population density and partially determines the pattern of dispersion. Dispersing juveniles are forced into vacant areas, marginal habitats, or distant areas from birth sites by aggressive behavior in residents. Extrinsic factors which regulate density and determine spatial distribution include food resources and predation. The social system and behavior typifies that of a mammalian species adapted to a dispersed, solitary way of life.
Trimodal cloudiness and tropical stable layers in simulations of radiative convective equilibrium

[1] In this paper, we examine the tropical environment at radiative convective equilibrium using a large-domain cloud system resolving numerical model. As in observed studies of convectively active periods over warm tropical oceans (in particular the tropical western Pacific), we find a trimodal cloud structure that is closely associated with the presence of three distinct stable layers, including a prominent stable layer located near the zero-degree Celsius level. In addition, the simulation exhibits three separate large scale zonal overturning circulations, with two of these circulations located above the trade wind inversion and separated by the freezing level stable layer. At equilibrium, latent heat release associated with freezing and melting processes is dwarfed by that of vapor transitions, and simulation results suggest that this stable layer can be maintained by subsidence in the presence of longwave radiative cooling above the zero-degree level. Citation: Posselt, D. J., S. C. van den Heever, and G. L. Stephens (2008), Trimodal cloudiness and tropical stable layers in simulations of radiative convective equilibrium, Geophys. Res. Lett., 35, L08802, doi:10.1029/ 2007GL033029.
Authentic leadership and the narrative self

Abstract Contemporary leadership theory and practice describes authenticity in relation to self-awareness of one's fundamental values and purpose, and attributes the motivational effects of leadership to the consistency of leader's values and behaviors and the concordance of their values with those of followers. Drawing from hermeneutic philosophy, I offer a different perspective on authenticity in leadership that is based on the framework of the narrative self. This framework suggests that authenticity is not achieved by self-awareness of one's inner values or purpose, but instead is emergent from the narrative process in which others play a constitutive role in the self. Implications of this framework for research and for the practice of ethical leadership are discussed.
Exciton-Optical Properties of TlBr and TlCl

The effect of strain on thallous-halide films has been investigated, and a technique developed for producing essentially strain-free films. The optical absorption of strain-reduced TlBr and TlCl films has been measured down to 4.2\ifmmode^\circ\else\textdegree\fi{}K, and the results analyzed for the optical constants. Relatively narrow (2-meV) firstexciton lines were found in the near ultraviolet accompanied by longitudinal-optical-phonon sidebands. The Faraday rotation pattern was measured through the first peak in TlBr and found to be linear in $H$. An analysis of the rotation pattern together with the known $n$ and $\ensuremath{\kappa}$ yields an exciton effective $g$ value of 0.7 for TlBr. Oscillatory magnetoabsorption has been observed in both TlBr and TlCl originating from the edge of the sideband. The exciton binding energies are 6.5\ifmmode\pm\else\textpm\fi{}1 meV in TlBr and 11\ifmmode\pm\else\textpm\fi{}2 meV in TlCl. The exciton-optical transition is discussed and the importance of lattice and polaron effects emphasized.
Effect of level of confusability on reporting letters from briefly presented visual displays

In a report paradigm, two letters are presented on a trial which are either confusable(e.g., P and R) or nonconfusable (e.g., P and M) in terms of visual features. Across trials, interletter distance, retinal location, duration, and visual field are varied. Identification accuracy on confusable trials was generally lower than on nonconfusable trials, and this effect of level of confusability increased with distance from the fixation point, decreased with duration, and was smaller on the central letter than on the more peripheral letter. A quantitative model, incorporating aspects of the interactive channels model (Estes, 1972) and feature perturbation model (Wolford, 1975), is developed and tested. One parameter of the model measures the effective similarity between two letters after lateral inhibition has occurred, and other parameters measure the probability of feature perturbation in foveal and peripheral directions.
Probabilities for singleton and multiple pregnancies after in vitro fertilization

Abstract Objective: To help physicians provide risk estimates for specific pregnancy outcomes. Design: Computation of exact binomial probabilities for singleton and multiple pregnancies as a function of two inputs: the number of embryos transferred and the implantation rate. Inputs were varied over the range of values reported in the literature. Main Outcome Measure(s): Probabilities for a singleton pregnancy ( P one ), a multiple pregnancy ( P mult ), and no pregnancy ( P none ) after one IVF cycle. Result(s): Given a 30% implantation rate and three embryos transferred, P one = .44, P mult = .22, and P none = .34. Although further increasing the number of embryos transferred increases the chance of pregnancy, it also raises the probability of a multiple pregnancy and lowers the chance of a singleton pregnancy. Although varying the implantation rate changes the specific probability estimates, the same trade-off persists. Conclusion(s): Those who consider an IVF "success" to be a singleton pregnancy should be attentive to the number of embryos transferred. Infertility therapy may be one area in medicine where more is not necessarily better.
Biracial/Bicultural Identity in the Writings of Sui Sin Far

At the turn into the twentieth century, American culture witnessed related literary and political shifts through which marginalized voices gained increased strength despite the severe racism that informed US laws and social interaction. Many authors and literary critics saw connections between literary content and social influence. For example, in Criticism and Fiction (1891), William Dean Howells, proponent of nineteenth-century American realism, warns readers to avoid sentimental or sensational novels, which he claims "hurt" by presenting "idle lies about human nature and the social fabric." He reminds us that "it behooves us to know and to understand" our people and our social context "that we may deal justly with ourselves and with one another" (94-95). He argues that the writer of fiction is obligated to write that which is "true to the motives, the impulses, the principles that shape the life of actual men and women" in the US (99). His is both a demand for aesthetic standards in fiction and an insistence that the failure to achieve "true" representations of American people will result in the disintegration of national humanity and, consequently, of national unity. The irony of Howells' standards is that despite this impulse toward national unification, his own tenets of American realism have for years served to exclude from the canon those writers who were greatly interested in creating "true" representations of American characters in order to promote a society in which Americans could finally "deal justly with ourselves and with one another."l One artist who wrote with the goal of creating an America where we would "deal justly" with one another was turn-of-thecentury Eurasian journalist and fiction writer Sui Sin Far.2 In an essay entitled "The Chinese in America," Sui Sin Far laments western literary depictions of the Chinese that portray them as "unfeeling" and "custom-bound." "[F]iction writers seem to be so im
Industry demand characteristics and the structure-performance relationship

Abstract Theoretical models of industrial profitability have included the price clasticity of demand among the structural elements that explain profitability. Empirical studies have accounted for variations in demand characteristics across industries by sample partition or use of broadly defined dummy variables. Variations in demand characteristics across industries can be modeled directly, by including among the variables that explain industrial profitability the share of industry sales going to different classes of consumers, for example, final consumer demand and different segments of the public sector. In empirical tests, inclusion of such demand share variables improves the explanatory power of the model, especially for consumer goods industries.
SURGERY OF PERIURETERIC OBSTRUCTION IN 101 CHILDREN OVER ONE YEAR OF AGE

One hundred and one children over 1 year of age have had surgery for pelviureteric obstruction over an 11 year period. The common clinical features were abdominal pain, urinary infection or haematuria, but a number presented as an incidental finding. Less commonly, the patients presented with an abdominal mass or with hypertension. The diagnosis was usually made on intravenous pyelography (IVP) but in the latter part of the series, renal nuclide scan (RNS) and ultrasonography (US) were preferred. Ninety-three patients had a unilateral pyeloplasty, three had bilateral pyeloplasty and five had nephrectomy or heminephrectomy. Whereas initially nephrostomy drainage was used in the majority of patients after pyeloplasty, a trend away from nephrostomy evolved in the latter part of the series. With experience, the incidence of postoperative complications was also reduced and there was a reduction in the period of hospitalization. Clinical results were consistently satisfactory. Postoperative assessment after pyeloplasty was made by IVP and/or RNS and also US. A review of these investigations showed that RNS provided more factual information of the result when compared with the IVP.
Scanning FCS, a novel method for three-dimensional particle tracking

We describe a novel method to track fluorescent particles in three dimensions with nanometre precision and millisecond time resolution. In this method, we use our two-photon excitation microscope. The galvomotor-driven x-y scanning mirrors allow the laser beam to move repetitively in a circular path with a radius of half the width of the point spread function of the laser. When the fluorescent particle is located within the scanning radius of the laser, the precise position of the particle in the x-x plane can be determined by its fluorescence intensity distribution along the circular scanning path. A z-nanopositioner on the objective was used to change the laser focus at two planes (half width of the point spread function apart). The difference of the fluorescence intensity in the two planes is used to calculate the z-position of the fluorescent particle. The laser beam is allowed to scan multiple circular orbits before it is moved to the other plane, thus improving the signal to noise ratio. With a fast feedback mechanism, the position of the laser beam is directed to the centre of the fluorescent particle, thus allowing us to track a particle in three dimensions. In this contribution we describe some calibration experiments performed to test the three-dimensional tracking capability of our system over a large range.
On the Use of a Simplified New Product Development Process in an Early-Stage Firm

Disciplined product development has been a hallmark of mature companies for many decades, resulting in shorter development cycles, reduced costs, and higher quality products. Unfortunately, these tools and processes have typically been applied in large, well-established firms, not start-up companies. In this paper, we describe a simplified new product development process for early-stage firms and its application to a consumer product in which the process was executed during a 14-month development cycle. The process consists of 15-steps in 3-phases, two decision gates, and provides a step-by-step guide for development, with specific call-outs as to what, when, and where tools such as market segmentation, platform planning, industrial design, and cost modeling should be applied. The proposed process is applied to design a new consumer product, and the case study results are discussed with specific emphasis on costs, duration, and applicability of the process and its related engineering tools. Finally, we conclude with comments on the limitations of the proposed process, potential improvements, and future work.Copyright © 2007 by ASME
Creation of an Artificial Bifunctional Intein by Grafting a Homing Endonuclease into a Mini-intein

The majority of inteins are comprised of a protein splicing domain and a homing endonuclease domain. Experimental evidence has demonstrated that the splicing domain and the endonuclease domain in a bifunctional intein are largely independent of each other with respect to both structure and activity. Here, an artificial bifunctional intein has been created through the insertion of an existing homing endonuclease into a mini-intein that is naturally lacking this functionality. The gene for I-CreI, an intron-encoded homing endonuclease, was grafted into the monofunctional Mycobacterium xenopi GyrA intein at the putative site of the missing endonuclease. The resulting fusion protein was found to be capable of protein splicing similar to that of the parent intein. In addition, the protein demonstrated site-specific endonuclease activity that is characteristic of the I-CreI homing endonuclease. The function of each domain therefore remained unaffected by the presence of the other domain. This artificial fusion of the two domains is a potential novel mobile genetic element.
Genetic diversity for agronomic and fiber traits in day-neutral accessions derived from primitive cotton germplasm

Upland cotton (Gossypium hirsutumL) is an important crop that is cultivated in warm climates through-out the world. Agronomic performance and fiber quality must continually be improved if cotton is to maintain economic viability. Primitive ancestors of cotton contain diversity for trait improvement; however, many of these accessions have a short-day flowering response (photoperiodic) and are not readily useable in breeding programs. In this study, 114 day-neutral derived primitive germplasm lines were evaluated in field trials for two years. Agronomic and fiber trait data were collected and analyzed. Variance components, genotypic values, and genotypic correlations were calculated. Genotypic effects for all traits studied made significant contributions to the phenotypic variation indicating genetic diversity among these lines. The predicted genotypic values showed a wide range of variation for agronomic and fiber traits. Weak genotypic correlations were found between yield and 2.5% span length and fiber strength, two important fiber traits. Although these day-neutral derived accessions had lower lint percentage, they had improved fiber length, strength, micronaire, and comparable yields with two commercial cultivars. Thus, these day-neutral derived accessions are sources of genetic variation that when used in breeding programs offer the potential to improve important traits and expand genetic diversity.
Mining enriched contextual information of scientific collaboration: A meso perspective

Studying scientific collaboration using coauthorship networks has attracted much attention in recent years. How and in what context two authors collaborate remain among the major questions. Previous studies, however, have focused on either exploring the global topology of coauthorship networks (macro perspective) or ranking the impact of individual authors (micro perspective). Neither of them has provided information on the context of the collaboration between two specific authors, which may potentially imply rich socioeconomic, disciplinary, and institutional information on collaboration. Different from the macro perspective and micro perspective, this article proposes a novel method (meso perspective) to analyze scientific collaboration, in which a contextual subgraph is extracted as the unit of analysis. A contextual subgraph is defined as a small subgraph of a large-scale coauthorship network that captures relationship and context between two coauthors. This method is applied to the field of library and information science. Topological properties of all the subgraphs in four time spans are investigated, including size, average degree, clustering coefficient, and network centralization. Results show that contextual subgprahs capture useful contextual information on two authors' collaboration. © 2011 Wiley Periodicals, Inc.
Friction and Wear of Ceramics for Magnetic Recording Applications: Part I—A Review

The friction and wear of ceramics under lightly-loaded, marginally-lubricated sliding-contact conditions are reviewed. The mechanism of ceramic friction and wear and the factors influencing them in these situations are identified and discussed with reference to the results presented in the literature. The implications to slider-material and thin-film rigid-disk overcoat material selection in magnetic recording devices are discussed
High resolution structures of the 4-4-20 Fab-fluorescein complex in two solvent systems: effects of solvent on structure and antigen-binding affinity.

Three-dimensional structures were determined for three crystal forms of the antigen binding fragment (Fab) of anti-fluorescein antibody 4–4-20 in complex with fluorescein. These included 1) a triclinic (P1) form crystallized in 47% (v/v) 2-methyl-2,4-pentanediol (MPD); 2) a triclinic (P1) form crystallized in 16% (w/v) poly(ethylene glycol), molecular weight 3350 (PEG); and 3) a monoclinic (P21) form crystallized in 16% PEG. Solvent molecules were added to the three models and the structures were refined to their diffraction limits (1.75-A, 1.78-A, and 2.49-A resolution for the MPD, triclinic PEG, and monoclinic PEG forms, respectively). Comparisons of these structures were interesting because 4–4-20 exhibited a lower antigen-binding affinity in 47% MPD (Ka = 1.3 x 10(8) M-1) than in either 16% PEG (Ka = 2.9 x 10(9) M-1) or phosphate-buffered saline (Ka = 1.8 x 10(10) M-1). Even though the solution behavior of the antibody was significantly different in MPD and PEG, the crystal structures were remarkably similar. In all three structures, the fluorescein-combining site was an aromatic slot formed by tyrosines L32, H96, and H97 and tryptophans L96 and H33. In addition, several active site constituents formed an electrostatic network with the ligand. These included a salt link between arginine L34 and one of fluorescein's enolate oxygen atoms, a hydrogen bond between histidine L27d and the second enolic group, a hydrogen bond between tyrosine L32 and the phenylcarboxylate group, and two medium range (approximately 5 A) electrostatic interactions with lysine L50 and arginine H52. The only major difference between the triclinic MPD and PEG structures was the degree of hydration of the antigen-combining site. Three water molecules participated in the above electrostatic network in the MPD structure, while eight were involved in the PEG structure. Based on this observation, we believe that 4–4-20 exhibits a lower affinity in MPD due to the depletion of the hydration shell of the antigen-combining site.
Effect of ECS on one-trial learning and on the partial reinforcement effect

Thirty-two naive male albino rats were trained to leverpress for sucrose using a discrete trial procedure. Half of the Ss were trained on a continuous reinforcement schedule (CRF), and the other half were trained on a variable-ratio schedule (VR). Following acquisition, for half of the Ss in each group a leverpress produced footshock followed by ECS. For the remaining Ss, a leverpress produced footshock only. While ECS produced apparent amnesia for the footshock in CRF-trained Ss, it did not produce amnesia for the footshock in VR-trained Ss. Further, VR-trained Ss which received ECS failed to show the partial reinforcement effect in extinction.
Reconciling Hydrodynamic Simulations with Spectroscopic Observations of Solar Flares

Chromospheric evaporation is a central element of current models of solar flares. The high-velocity upflows that should accompany evaporation, however, are rarely observed in high-resolution solar flare spectra. Thus the absence of blueshifted line profiles represents a significant discrepancy between the theory and observations of this phenomenon. In this Letter we present an algorithm for computing multiple-loop time-dependent hydrodynamic simulations of solar flares using a minimum of assumptions. We show that these simulations can accurately reproduce the Ca XIX and S XV line profiles observed with the Bragg Crystal Spectrometer on Yohkoh during the earliest stages of a flare. Since our model represents the flare as a succession of independently heated threads, the strongly blueshifted emission evident during the initial heating of a thread is largely masked by emission from threads that have been heated previously and do not show bulk motions.
BOLD fractional contribution to resting-state functional connectivity above 0.1 Hz.

Abstract Blood oxygen level dependent (BOLD) spontaneous signals from resting-state (RS) brains have typically been characterized by low-pass filtered timeseries at frequencies ≤ 0.1 Hz, and studies of these low-frequency fluctuations have contributed exceptional understanding of the baseline functions of our brain. Very recently, emerging evidence has demonstrated that spontaneous activities may persist in higher frequency bands (even up to 0.8 Hz), while presenting less variable network patterns across the scan duration. However, as an indirect measure of neuronal activity, BOLD signal results from an inherently slow hemodynamic process, which in fact might be too slow to accommodate the observed high-frequency functional connectivity (FC). To examine whether the observed high-frequency spontaneous FC originates from BOLD contrast, we collected RS data as a function of echo time (TE). Here we focus on two specific resting state networks — the default-mode network (DMN) and executive control network (ECN), and the major findings are fourfold: (1) we observed BOLD-like linear TE-dependence in the spontaneous activity at frequency bands up to 0.5 Hz (the maximum frequency that can be resolved with TR = 1 s), supporting neural relevance of the RSFC at a higher frequency range; (2) conventional models of hemodynamic response functions must be modified to support resting state BOLD contrast, especially at higher frequencies; (3) there are increased fractions of non-BOLD-like contributions to the RSFC above the conventional 0.1 Hz (non-BOLD/BOLD contrast at 0.4–0.5 Hz is ~ 4 times that at
Highly concentrated ceramic bonding suspensions and the influence of the concentration factor

The marked influence of the volume concentration of the suspension during wet milling of VKVS on the properties of these materials was established. To characterize the concentrations of VKVS it is proposed to use the factor of volume solid-liquid ratio, OTZh. It was established that, the content of kinetically bonded liquid Cws in stabilized VKVS, and also the porosity of the casting Pcast based on them, is inversely proportional to the values of OTZh in obtaining the suspension. It is shown that the product of the factors OTZh·Cws and OTZh·Pcast are constant magnitudes, and on average amount to 0.30 and 34.5 respectively. In the range of concentrations for Cv of from 0.60 to 0.75, most typical for VKVS, corresponding to the two-fold increase in OTZh (from 1.5 to 3.0) we note a halving of the factors Cws and Pcast. Rules were formulated for determining OTZh (the OTZh rule). Proposals are made about the mechanisms determining the regularities that were revealed in this work.
Anomalous spin polarization of GaAs two-dimensional hole systems

We report measurements and calculations of the spin-subband depopulation, induced by a parallel magnetic field, of dilute GaAs two-dimensional 2D hole systems. The results reveal that the shape of the confining potential dramatically affects the values of an in-plane magnetic field at which the upper spin subband is depopulated. Most surprisingly, unlike 2D electron systems, the carrier-carrier interaction in 2D hole systems does not significantly enhance the spin susceptibility. We interpret our findings using a multipole expansion of the spin density matrix, and suggest that the suppression of the enhancement is related to the holes’ band structure and effective spin j=3/2.
Hormonal stimulation of avian embryonic cartilage growth in vitro: Histologic and ultrastructural features

We studied the histologic and ultrastructural features of embryonic chick cartilage after the cartilage had been incubated in serum-free medium that contained hormones and growth factors known to stimulate in vitro cartilage growth. Pelvic cartilages from 9 d chick embryos were incubated in BGJb (Fitton-Jackson modification) medium alone (control) or medium containing one of the following:N 6 monobutyryl cyclic AMP 0.5 mM, forskolin 100 μM, triiodothyronine (T3) 10 nM, insulin 45 nM, or somatomedin C 0.67 nM. At the end of 3 d of incubation the cartilages were fixed in buffered formalin. Significant growth (increases in size, wet and dry weight) was seen with each treatment group. N6-Monobutyryl cAMP treated cartilage had an increased number of flattened immature chondrocytes with large nuclei and prominent nucleoli. The histologic and ultrastructural features of forskolin treated cartilage were indistinguishable from N6-monobutyryl cAMP treatment. The T3 treated cartilage contained large hypertrophic chondrocytes with prominent lacunar typical of mature cartilage. T3 Treated cartilage had considerable vacuole formation and dilated endoplasmic reticulum. Insulin and somatomedin treated cartilage had histologic appearance similar to control cartilage. Thus, the effects of various hormones on embryonic cartilage growth in vitro can be separated as to whether growth is the result of chondrocytic hyperplasia (cyclic AMP mediated), chondrocytic hypertrophy with maturation (T3), or a combination of both hyperplasia and hypertrophy (insulin and somatomedin-C).
Insect sensory systems inspired computing and communications

Insects are the most successful group of living things in terms of the number of species, the biomass and their distribution. Entomological research has revealed that the insect sensory systems are crucial for their success. Compared to human brains, the insect central nerve systems are extremely primitive and simple, both structurally and functionally, and are of minimal learning ability. Faced with these constraints, insects have evolved a set of extremely effective sensory systems that are structurally simple, functionally versatile and powerful, and highly distributed, as well as noise and fault tolerant. As a result, in recent years insect sensory systems have been inspirational to new communications and computing paradigms, which have lead to significant advances. However, we believe that the potential for insect-inspired solutions for communications and computing is far from being fully recognized. In particular, the contrasting similarity between the ubiquitous existences of insect sensory networks in nature and the idea of pervasive computing has received little attention. For example, the chemosensory communication systems in many of the moth, ant and beetle populations are essentially ''wireless'' sensory networks. The difference between the ''wireless'' network of an insect population and an engineered wireless sensor network is that insects encode messages with semiochemicals (also known as infochemicals) rather than with radio frequencies; in addition, the computing node is the individual insect powered by its brain, sensory and neuromotor systems, rather than a microchip-powered sensor. The objectives of this paper are threefold: (1) to introduce the state-of-the art research in insect sensory systems from entomological perspectives; (2) to propose potential new research problems inspired by insect sensory system with focusing on unexplored fields; and (3) to justify how and why insect sensory systems may inspire novel computing and communications paradigms.
Conductance of HCl, NaCl, Na acetate, and acetic acid in water-ethylene carbonate solvent mixtures at 25 and 40°C

The molar conductances of solutions of hydrochloric acid, sodium chloride, sodium acetate, and acetic acid were measured in water-ethylene carbonate (EC) solvent mixtures at 25 and 40°C. These solvents have dielectric constants higher than that of water. Four solvent compositions, in which the mole fraction (x2) of EC was 0.2, 0.4, 0.5, and 0.6, were studied at 25°C. For HCl and acetic acid at 40°C, additional measurements were made atx2=0.8 and 1.0. Analysis of the data by the Pitts equation was successful up tox2=0.6 and for HCl tox2=0.8. A graphical method, together with Λ0 derived from the measurements for HCl, NaCl, and NaAc, yielded the dissociation constant of acetic acid up tox2=0.6. As EC is added, all the compounds studied displayed increased ion association. The acidic strength of acetic acid is greatly reduced; the dissociation constant atx2=0.6 is only 1/1000 that in water. The behavior of these electrolytes reflects the poor solvating power of EC, and the dielectric constant plays only a minor role.
The isolation of a suppressible nonsense mutant in mammalian cells

Abstract An HGPRT − cell line derived from mouse L cells has been shown to have the following properties: it is CRM + ; the defective HGPRT molecules are altered in the carboxyterminal peptide; the mutant cells regain HGPRT activity when ochre-suppressor tRNA is microinjected into them, but not when amber-suppressor or wild-type tRNAs are injected. We conclude from these properties that this mutant cell line contains an ochre nonsense mutation (UAA) in the structural gene for HGPRT.
Effect of Language and Task Demands on the Diagnostic Effectiveness of the Autism Diagnostic Observation Schedule: The Impact of Module Choice

The ADOS characterizes socio-communicative deficits in autism spectrum disorders (ASD). In this study the effect of module choice on ADOS classification was examined. For 74 participants (52 autism, 22 PDD-NOS), Module 1 and Module 2 were administered in a single session. Fifty-one participants maintained ADOS classification, with 17 more impaired on M2 and 6 more impaired on M1. For 64 participants (25 autism, 39 PDD-NOS), Module 2 and Module 3 were administered. Thirty-nine participants maintained classification, with 24 more impaired on M3 and 1 more impaired on M2. As expected, more impairment was indicated when a module with more language and task demands was administered. Clinical judgment of the most appropriate module for administration was found to be important.
Unattended optimisation of normal phase high-performance liquid chromatography separations with a microcomputer controlled chromatograph

The use of the sequential simplex procedure with a microcomputer controlled chromatograph to carry out unattended optimisation of normal phase separations is described. It is shown that by examining the second derivative of the final chroamtogram further information can be obtained about the quality of the optimum. Further optimisation can then be carried out should a truly optimised separation not have been achieved initially.
The behavioral effects of REM sleep deprivation in rats.

Four experiments were performed to test the behavioral effects of REM deprivation on rats. Two studies of avoidance learning showed that shuttle avoidance and runway avoidance were unaffected by REM deprivation. REM deprivation produced an enhancement of activity, and the addition of periodic shock demonstrated a failure of adaptation for REM-deprived subjects. These data were interpreted as indicating that REM deprivation produces motivational effects on rat behavior and that electric shock-induced pain and REM deprivation interact to change activity patterns. It was concluded that the findings of the present experiment can be explained most parsimoniously in terms of increased sensitivity of REM-deprived subjects to environmental stimulation.
Depression in women: implications for health care research

Epidemiologic data from around the world demonstrate that major depression is approximately twice as common in women than men and that its first onset peaks during the childbearing years. Progress has been made in understanding the epidemiology of depression and in developing effective treatments. Much remains to be learned about the basic pathogenesis of depression and the specific treatment needs of depressed women and their offspring, especially during the reproductive years.