cssi/SciSciGPT-SciSciNet huggingface dataset:
Diffuse ultrasonic backscatter in a two-dimensional domain

The scattering of elastic waves in polycrystalline materials is relevant for ultrasonic materials characterization and nondestructive evaluation (NDE). Diffuse ultrasonic backscatter measurements are used widely to extract the microstructural parameters such as grain size and also to detect flaws in materials. Accurate interpretation of experimental data requires robust scattering models. Line transducers are often used for ultrasonic experiments such that an appropriate model for these two-dimensional problems is needed. Here, a theoretical expression for the temporal diffuse backscatter is derived for such domains under a single-scattering assumption. The result is given in terms of transducer and microstructural parameters. In addition, the problem is examined in terms of numerical simulations using Voronoi polycrystals that are discretized using finite elements in a plane-strain formulation. The material properties of the individual Voronoi cells are chosen according to appropriate material distributions. Such numerical models also allow scattering theories, including the one discussed here, to be examined for well-controlled microstructures. Example numerical results for materials with varying degrees of scattering that are of common interest are presented. The numerical results are compared with the theory developed with good agreement. These results are anticipated to impact ultrasonic NDE of polycrystalline media.
Digital Media, Race, Gender, Affect, and Labor: Introduction to Special Section

This essay provides a brief introduction to how the special section of Television & New Media came about and discusses the concepts of race, gender, affect, and labor in relation to digital media as it is manifested in the present decade of public availability of the Internets.
Breaking the 10(-7) barrier for RI measurements in nanoliter volumes.

Refractive index (RI) detection is a common technique used in chemical and biochemical analysis. It can be employed to perform universal solute detection in μHPLC and CE, as well as temperature measurements. However, accurate RI measurements in nanoliter volumes still present a significant challenge. Here we present an alternative method to extract RI information encoded in spatial distribution of the backscattered fringes produced by a microinterferometric backscatter detector (MIBD) based on spatial Fourier analysis. By monitoring the phase in the Fourier domain, we were able to obtain detection limits of 7 × 10-8 RIU. It was also shown that such calculations could be performed in real time, thus making MIBD with Fourier analysis compatible with μHPLC, CE, and FIA.
Introduction of high molecular weight (IgG) proteins into receptor coupled, permeabilized smooth muscle.

The permeability to high molecular weight (IgG, 150 kD) proteins of the plasma membrane of receptor-coupled smooth muscles permeabilized with beta-escin was determined using confocal microscopy of immunofluorescent tracers and measurement of lactate dehydrogenase (LDH, 135-140 kD) leakage. Permeabilized strips of rabbit portal vein and guinea pig ileum were incubated in a relaxing solution containing mouse anti-smooth muscle alpha-actin antibody and immunostained with F(ab')2 labeled with tetramethyl rhodamine isothiocyanate. Confocal light microscopy of Triton X-100 and beta-escin permeabilized cells showed homogeneous staining of the cytoplasm, whereas in alpha-toxin treated and intact preparations only damaged cells at the edges of the strips were stained. Both the Ca(2+)-sensitizing effect of phenylephrine, in rabbit portal vein, and Ca2+ release by carbachol in guinea pig ileum, were retained after permeabilization and the treatment with the primary antibody. During the 30 min permeabilization, 38%, and within the next 75 min an additional approximately 30%, of the total LDH leaked out from the beta-escin-treated group, but not from the alpha-toxin-treated group (3.2%). The responsiveness to agonist and maximum contractility was improved if the preparations were incubated during the introduction of proteins at 4 degrees C, rather than 24 degrees C. Ca(2+)-independent myosin light chain kinase (61 kD) contracted the permeabilized portal vein in the absence of free Ca2+ (pCa < 8). In conclusion, permeabilization with beta-escin allows the transmembrane passage of 150 kD proteins under our experimental conditions that also retain receptor-coupled signal transduction.
Spine surgery training: is it time to consider categorical spine surgery residency?

Spine surgery training: is it time to consider categorical spine surgery residency? Alan H. Daniels, MD*, Christopher P. Ames, MD, Steven R. Garfin, MD, Christopher I. Shaffrey, MD, K. Daniel Riew, MD, Justin S. Smith, MD, PhD, Paul A. Anderson, MD, Robert A. Hart, MD Department of Orthopaedic Surgery, Warren Alpert Medical School of Brown University, 2 Dudley Street. Providence, RI 02905, USA Department of Neurological Surgery, University of California San Francisco, 505 Parnassus Ave., Rm. M779, San Francisco, CA 94143, USA Department of Orthopaedic Surgery, University of California San Diego, Perlman Ambulatory Care Center, 9350 Campus Point Drive, La Jolla, CA 92037, USA Department of Neurological Surgery, University of Virginia, P.O. Box 800386, Charlottesville, VA, 22908, USA Department of Orthopaedic Surgery, Washington University, Cervical Spine Institute. 4921 Parkview Place, A12, St. Louis, MO 63110, USA Department of Orthopaedic Surgery, University of Wisconsin, 1685 Highland Ave., UWMFCB – 6215, Madison, WI 53705, USA Department of Orthopaedics and Rehabilitation, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA
Effect of subtype-selective opioid receptor blockers on nitrous oxide antinociception in rats.

Abstract Nitrous oxide antinociception in rats was evaluated by the warm water tail withdrawal test following central pretreatment with blockers of various opioid receptor subtypes. The analgesic dose, 50% (AD50) value for nitrous oxide antinociception was significantly elevated by MR-2266 (which is relatively selective for κ-opioid receptors) and increased to a lesser degree by ICI-174,864 (which is selective for δ-opioid receptors). However, pretreatment with β-funaltrexamine (which is selective for μ-opioid receptors), even at extremely high doses, was ineffective in altering the AD50 for nitrous oxide antinociception. According to these findings, nitrous oxide antinociception, as evaluated in this paradigm, appears to be mediated by κ- and possibly δ- but not μ-opioid receptors.
Acknowledging the infrasystem: A critical feminist analysis of systems theory

Abstract The article examines the absence of a critical feminist perspective in the application of systems theory as a unifying paradigm for public relations. The article contends that such a paradigm actually works in opposition to the potential for excellence in public relations management posited by Grunig and others because it uncritically accepts the gendered, racist, classist and heterosexist norms that support systems theory. The article suggests that systems theory fails to acknowledge the existence of a third system that supports the approaches used by organizations to achieve homeostasis, balance or symmetry. A third system, the infrasystem, constructs both suprasystem and subsystem interactions. The article concludes with a case analysis of the institution of sport to illustrate how the infrasystem functions to preserve a system of gender privilege.
Potential uses of google glass in the pharmacy.

Technology companies are in a constant battle for consumers’ interest in their products. This leads to rapid change and innovation. Google Glass is a recent innovation that will soon be available to the general public. In this article, we briefly describe our experiences with Google Glass and suggest ways we think it can be used in the hospital pharmacy setting.
In vivo lipid-derived free radical formation by NADPH oxidase in acute lung injury induced by lipopolysaccharide: a model for ARDS

Intratracheal instillation of lipopolysaccharide (LPS) activates alveolar macrophages and infiltration of neutrophils, causing lung injury/acute respiratory distress syndrome. Free radicals are a s...
Interactions between hepatitis B virus and polymeric human albumin. I. Production of monoclonal anti-idiotypes (anti-anti-polymeric human albumin) which recognize hepatitis B virus surface antigen.

In an attempt to characterize the polymeric human albumin (polyHSA) receptor expressed on hepatitis B virus and hepatocytes, we have used a human anti-polyHSA IgG to generate monoclonal anti-idiotypes (anti-Id) which bear the internal image of polyHSA and mimic its binding activity. Two monoclonal anti-Id antibodies, 63.14 and 70.F9, were strongly reactive in both radioimmunoassay and enzyme-linked immunosorbent assay (ELISA) with the F(ab')2 of the immunogen as well as with purified hepatitis B surface antigen (HBsAg) expressing various subtypes. The specificity of the binding of anti-Id to HBsAg was confirmed in direct ELISA and by Western blot analysis. These experiments also showed that the anti-Id bind to a site expressed on the major 24-kDa protein of HBsAg particles, and that this recognition is specifically inhibited by polyHSA. Experiments on cellular staining and radioimmunoprecipitation on HBsAg-positive and -negative cell lines showed that the anti-Id recognize intracellular HBsAg but not other liver cell proteins, including the putative polyHSA receptor. These data indicate, therefore, that the monoclonal anti-Id mimic the binding activity of polyHSA and recognize its binding site on the virus. The inability of both anti-Id to react with the hepatocyte surface suggests either the absence of a specific hepatic polyHSA receptor or the expression of one with a different configuration.
Ductile/brittle grain-boundary fracture behaviour of L12-type intermetallic compounds

The fracture behaviour of grain boundaries in L12-type intermetallic compounds was investigated to explain recent experimental results reported by Takasugiet al. and Inoueet al. Inspection of these results revealed a simple rule; grain boundaries are ductile in Kurnakov compounds having an order-disorder transition below their melting point and a wide solid-solution field. On the other hand, grain boundaries are brittle in Berthollide compounds having no order-disorder transition below their melting point. The ductile grain-boundary behaviour in Kurnakov compounds is considered to be produced by disordered grain boundaries, intrinsically ductile and inherited when formed in disordered states.
Direct Observation of Morphological Tranformation from Twisted Ribbons into Helical Ribbons

We report on the direct observation of a nanostructural transformation from a twisted ribbon to a helical ribbon in supramolecular assemblies of peptide amphiphiles. Using cryogenic electron microscopy, a peptide amphiphile molecule containing aromatic residues was found to first assemble into short twisted ribbons in the time range of seconds, which then elongate in the time scale of minutes, and finally transform into helical ribbons over the course of weeks. By synthesizing an analogous molecule without the aromatic side groups, it was found that a cylindrical nanostructure is formed that does not undergo any transitions during the same time period. The study of metastable states in peptide aggregation can contribute to our understanding of amyloid-related diseases, such as Alzheimer's disease.
Power harvesting from rotation

We show the impossibility of harvesting power from rotational motions by devices attached to the rotating object. The presentation is suitable for students who have studied Lagrangian mechanics.
Anatomically based measurement of facial expressions in simulated versus hypnotically induced affect

In an attempt to determine whether hypnotically induced affect could be reliably discriminated from simulations, three hypnotically trained female undergraduate subjects were presented with posthypnotic cues to either experience or simulate varying degrees of anxiety and pleasure. Facial expressions generated by subjects in response to these cues were recorded on videotape and coded by means of the Facial Action Coding System (FACS). It was hypothesized that simulated emotional expressions, requiring greater cortical processing, would be marked by longer onset latencies and greater irregularity or fluctuation in muscular contraction than the presumably automatic changes in facial behavior accompanying posthypnotic emotions. Statistical analyses confirmed both expectations. The results were viewed as reflecting support for the validity of posthypnotically cued affect.
Onset of nanoscale wear of metallic implant materials: Influence of surface residual stresses and contact loads

Abstract Nanoscale wear response of cobalt–chromium alloy (ASTM F-75) was investigated as a function of contact load and surface residual stress in order to identify mechanism governing onset of surface damage in modular implants. A unique loading configuration was utilized to apply range of known in-plane stress states to the specimen surface in order to simulate different residual stress levels. Using the tip of a scanning force microscope as a well characterized “asperity,” controlled contact forces were applied on the specimen to mechanically stimulate the loaded surface. Volume of material removed was measured to characterize the wear rate as a function of the contact loads and surface stress state. Experimental measurements of material removal indicate that a critical level of contact pressure is required to initiate wear of the cobalt-chromium surface and as expected higher contact pressures accelerate the wear process. At a constant contact pressure, wear rate is accelerated by compressive in-plane stress while tensile in-plane stresses tend to suppress the surface wear. A surface damage mechanism based on successive damage/delamination of native oxide covered surface due to single asperity contact and repassivation of exposed surface is proposed to elucidate the experimental observations.
Humanization of lepidopteran insect-cell-produced glycoproteins.

The insect cell−baculovirus expression vector system, widely used for glycoprotein production, is not ideal for pharmaceutical glycoprotein production due to the characteristics of the N-glycans in the expressed products. Insect cells lack several enzymes required for mammalian-type N-glycan synthesis and contain a specific N-acetylglucosaminidase that stunts the growth of chains and a core α-1,3-fucosyltransferase that yields potentially allergenic glycoforms. Current knowledge on N-glycan processing in lepidopteran insect cells is summarized, and strategies to develop better glycoprotein expression systems suitable for pharmaceutical glycoprotein production are discussed.
Special Issue on the Social Action and Advocacy Paradigm in Art Therapy: The Lens of Art Therapy Opens Larger Still

I have never been more proud or more willing to claim art therapy as my tribe than in reading and introducing the articles presented in this special issue. The authors take us through a full spectr...
Tropical Storm Development from African Easterly Waves in the Eastern Atlantic: A Comparison of Two Successive Waves Using a Regional Model as Part of NASA AMMA 2006

Abstract Two successive African easterly waves (AEWs) from August 2006 are analyzed utilizing observational data, the European Centre for Medium-Range Weather Forecasts reanalysis, and output from the National Center for Atmospheric Research–National Oceanic and Atmospheric Administration Weather Research and Forecasting model (WRF) to understand why the first wave does not develop over the eastern Atlantic while the second wave does. The first AEW eventually forms Hurricane Ernesto over the Caribbean Sea, but genesis does not occur over the eastern Atlantic. The second wave, although weaker than the first over land, leaves the West African coast and quickly intensifies into Tropical Storm Debby west of the Cape Verde islands. This study shows that the environmental conditions associated with the first AEW’s passage inhibited development. These conditions include strong low- and midtropospheric vertical wind shear owing to a stronger than normal African easterly jet, lower than normal relative humidity, a...
Blocking IL-1 in systemic inflammation

A growing number of systemic inflammatory diseases characterized in part by recurrent fevers, leukocytosis, anemia, and elevated acute phase proteins are linked to interleukin (IL)-1 activity since rapid and sustained resolution is observed upon specific blockade of IL-1 receptors. Rapid resolution of systemic and local inflammation is now also reported in systemic onset juvenile idiopathic arthritis (SoJIA). Loss of control of the secretion of IL-1β might be a common mechanism explaining the aberrant activity of IL-1 in these diseases.
The effects of lubrol WX on brain membrane Ca2+/Mg2+ ATPase and ATP-dependent Ca2+ uptake activity following acute and chronic ethanol.

1. Acute administration of ethanol (2.5 gm/kg, i.p.) to rats inhibits the cytosolic buffering of Ca2+ in nerve terminals. 2. Ca2+ ATPase and ATP-dependent Ca2+ uptake are both inhibited 30 min after a single dose of ethanol. 3. Chronic ethanol administration (6%, 14 days) did not inhibit Ca2+ ATPase but significantly stimulated ATP-dependent Ca2+ uptake. 4. Lubrol WX treatment of acute ethanolicmembranes reverses the inhibition of Ca2+ ATPase seen following ethanol. 5. Lubrol WX treatment of chronic ethanolic membranes prevents the increase in ATP-dependent Ca2+ uptake seen in ethanolic membranes. 6. Both acute and chronic ethanol-induced changes in Ca2+ transport within nerve teminals may involve lipid-dependent parameters of the membrane which may underlie neuronal adaptation.
Egg Transmission of Avian Lymphomatosis

Abstract THE PROBLEM OF EGG TRANSMISSION IN THE study of any disease it is important to know the natural modes of transmisssion because such knowledge may lead to useful control or eradication measures. Three main natural modes of transmission for avian lymphomatosis have been suggested: (1) through direct contact of infected with non-infected birds. (2) through indirect contact with the secretions and excretions, blood, etc., of infected birds by means of contaminated equipment, air, feed, caretakers, insects and rodents, and (3) through the egg from infected parents to the offspring (Cottral, 1952b). The hypothesis that lymphomatosis may be transmitted through the egg has neither been proved nor disproved, even though it has been more than 23 years since Doyle (1929) suggested that the disease may be transmitted in this manner. Since then, many workers have presented observations and experimental evidence both for and against this contention. Epiornithological observations on the spread …
Bird species diversity in riparian buffers, row crop fields, and grazed pastures within agriculturally dominated watersheds

In response to concern about the loss of ecosystem services once provided by natural riparian systems, state and federal agencies have established incentive programs for landowners to convert sensitive lands from agricultural to conservation uses. Enhancement of wildlife habitat, while identified as a function of such systems, has often been of secondary importance to soil conservation and water quality objectives. Though greatly important, little consideration has been given to how specific species will respond to the design and management of riparian buffers or other conservation lands. This study compared avian communities within a chronosequence of riparian buffers established on previously cropped or pastured land with those of the nearby matrix land cover types (row crop fields and an intensively grazed pasture). The riparian buffers consisted of native grasses, forbs, and woody vegetation established at three different times (2, 9, and 14+ years prior to survey). At each site, 10 min point counts for breeding birds were conducted using 50 m fixed radius plots, which were visited eight times between May 15 and July 10, 2008. A total of 54 bird species were observed over all of the study sites. The re-established riparian buffers in this study had higher bird abundance, richness, and diversity than the crop and pasture sites. These results suggest that re-establishing native riparian vegetation in areas of intensive agriculture will provide habitat for a broad suite of bird species, but that specific species will reflect successional stage, horizontal and vertical vegetative structure, and compositional diversity of the buffer vegetation. These results emphasize the importance of matching buffer design and management to species requirements if the objectives are to attract specific target species or species groups.
Chemical Warfare and Medical Response During World War I

The first large-scale use of a traditional weapon of mass destruction (chemical, biological, or nuclear) involved the successful deployment of chemical weapons during World War I (1914–1918). Historians now refer to the Great War as the chemist’s war because of the scientific and engineering mobilization efforts by the major belligerents. The development, production, and deployment of war gases such as chlorine, phosgene, and mustard created a new and complex public health threat that endangered not only soldiers and civilians on the battlefield but also chemical workers on the home front involved in the large-scale manufacturing processes. The story of chemical weapons research and development during that war provides useful insights for current public health practitioners faced with a possible chemical weapons attack against civilian or military populations.
1156 POLYOL PATHWAY HYPERKINESIS IN CHILDREN WITH DIABETES

Intracellular sorbitol accumulation has been implicated as an etiologic factor for many of the sequelae of diabetes mellitus. The human erythrocyte is a tissue that accumulates sorbitol in response to extracellular glucose concentration. Red cell sorbitol levels in children with diabetes were compared to those in red cells from non diabetics. Sorbitol was measured by a fluorometric assay utilizing sheep liver sorbitol dehydrogenase; glucose was measured by glucose oxidase. Red cell sorbitol in 140 children with diabetes (36.6±1.7nmols/gm Hb) was greater than in 50 non diabetics (10.3±.79) p<.0005. The influence of extracellular glucose was taken into account by expressing intracellular sorbitol in terms of plasma glucose concentration (S/G). The S/G ratio for red cells from diabetics was 20.6±.88 and non diabetics was 12.1±.95 p<.0005. When red cells from diabetics were exposed to non diabetic glucose concentrations for up to 14 hours the S/G ratio did not return to non diabetic levels. Non diabetic red cells exposed to elevated glucose concentrations (300 and 500 mg/dl) for 3 hours did not manifest elevated S/G ratios. Elevated S/G ratios were found in association with non diabetic hemoglobin Alc values suggesting long term exposure to near physiologic glucose levels. Increased sorbitol production was found in most, but not all individuals with diabetes and seems to be an acquired characteristic. This is the first evidence of altered polyol pathway activity not directly related to substrate availability in spontaneous human diabetes.
Transparent and flexible quantum dot–polymer composites using an ionic liquid as compatible polymerization medium

Quantum dot (QD)–polymer composites were fabricated based on a solution of QDs dispersed in an ionic liquid. Positively charged water-soluble nanocrystals were obtained from solutions of CdSe/ZnS QDs dispersed in toluene by ligand exchange with 2-dimethylaminoethanethiol (DAET). The resulting QDs were further transferred into a hydrophobic ionic liquid HMITFSI (1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) by cation exchange, resulting in a CdSe/ZnS–HMITFSI solution, which was used as a compatible medium for the polymerization and cross-linking of polymethyl methacrylate networks. Transparent, fluorescent and flexible materials resulted. The quantum yields of the composites depended on the initial properties of the QDs dispersed in toluene, and medium-size QDs (2.6 nm) resulted in the highest quantum yields.
Oxygen free radicals and redox biology of organelles

The presence and supposed roles of reactive oxygen species (ROS) were reported in literature in a myriad of instances. However, the breadth and depth of their involvement in cellular physiology and pathology, as well as their relationship to the redox environment can only be guessed from specialized reports. Whatever their circumstances of formation or consequences, ROS seem to be conspicuous components of intracellular milieu. We sought to verify this assertion, by collecting the available evidence derived from the most recent publications in the biomedical field. Unlike other reviews with similar objectives, we centered our analysis on the subcellular compartments, namely on organelles, grouped according to their major functions. Thus, plasma membrane is a major source of ROS through NAD(P)H oxidases located on either side. Enzymes of the same class displaying low activity, as well as their components, are also present free in cytoplasm, regulating the actin cytoskeleton and cell motility. Mitochondria can be a major source of ROS, mainly in processes leading to apoptosis. The protein synthetic pathway (endoplasmic reticulum and Golgi apparatus), including the nucleus, as well as protein turnover, are all exquisitely sensitive to ROS-related redox conditions. The same applies to the degradation pathways represented by lysosomes and peroxisomes. Therefore, ROS cannot be perceived anymore as a mere harmful consequence of external factors, or byproducts of altered cellular metabolism. This may explain why the indiscriminate use of anti-oxidants did not produce the expected "beneficial" results in many medical applications attempted so far, underlying the need for a deeper apprehension of the biological roles of ROS, particularly in the context of the higher cellular order of organelles.
Cellular and molecular events in corneal wound healing: significance of lipid signalling

Alterations in the normal healing process after corneal injury can produce undesirable outcomes that range from corneal haze to ulceration and perforation. Lipids play important roles in the complex inflammatory processes that occur after corneal wounding. While some lipid mediators, such as the lipoxygenase derivatives of arachidonic acid, 12-hydroxyeicosatetraenoic acid (12[S]-HETE and 15[S]-HETE), act as second messengers to promote cell proliferation and are possibly involved in the synthesis of other molecules that suppress inflammation, others, such as platelet-activating factor (PAF), exert their actions through specific receptors, play key roles during sustained corneal inflammation (as might occur with chemical burns), and contribute to tissue destruction and neovascularization. PAF is also a strong inducer of selective metalloproteinases (MMPs) that degrade the extracellular matrix. The use of a new PAF antagonist has shown great promise for the treatment of diffuse lamellar keratitis (DLK) and alkali-burned corneas.
Lithium ratio and maintenance treatment response

Abstract Erythrocyte/plasma lithium ratios were determined in 41 bipolar manic depressive outpatients maintained on lithium for a mean of 64 months. Sixteen patients experienced affective episodes requiring additional pharmacologic intervention during periods when their plasma lithium averaged 0.7 meq/1 or above for at least 3 preceding months and they were on no concurrent medication known to induce depression or mania. These patients, considered to be a homogeneous group of non-responders to lithium, had a mean lithium ratio of 0.50 (range 0.15-1.16). Seven patients experienced affective symptoms at plasma levels below 0.7 meq/1 and/or while taking concurrent medication known to induce affective symptoms, and therefore could not be categorized clinically as lithium non-responders or responders. Eighteen remaining patients, who had no affective episodes during lithium maintenance, were found to have a mean erythrocyte/plasma ratio of 0.52 (range 0.19-1.05). This latter group of apparent responders should be considered heterogeneous in that it may include spontaneous remitters. The difference in mean ratios between the non-responder group and the apparent responder group was not statistically significant. These findings support the contention that the erythrocyte/plasma lithium ratio does not correlate with response of bipolar outpatients to maintenance lithium.
Bond-orientational order in liquid Si

We study bond‐orientational order in liquid Si via Monte Carlo simulation in conjunction with empirical two‐ and three‐body potentials of the form proposed by Stillinger and Weber. Bond‐orientational order (BOO) is described in terms of combinations of spherical harmonic functions. Liquid Si is found to have pronounced short‐range BOO corresponding to l=3, as expected for a structure with local tetrahedral order. No long‐range BOO is found either in the equilibrium or the supercooled liquid. When the three‐body potential is artificially removed, the tetrahedral bond‐orientation order disappears and the liquid assumes a close‐packed structure.
The Growing Size of Radiology Practices

Purpose To describe trends in the size of radiology practices from 1990 to 2007. Methods Data from the American College of Radiology's 1990, 1995, 2000, and 2003 surveys of radiologists and radiation oncologists and its 2007 survey of radiologist members are compiled to describe the changing distribution of radiologists by practice size over time. All estimates are weighted to be representative of all radiologists in the United States. Results The fraction of radiologists in small practices (1-4 radiologists) decreased from 29% in 1990 to 22% in 2007. The fraction in medium-sized practices (5-14 radiologists) decreased from 51% in 1990 to 38% in 2007. The fraction in practices with 15 to 29 radiologists increased from 14% in 1990 to 21% in 1995 and has since remained constant. The fraction in practices with 30 or more radiologists grew from 5% in 1990 to 19% in 2007, but since 2000, growth among these practices has largely been limited to practices with 60 or more radiologists. The median radiologist was in a 7-radiologist practice in 1990. This size increased to 11 in 2000 and was the same in 2007. The size of a practice at the 90th percentile of radiologists increased from 22 in 1990 to 45 in 2007. Conclusion Radiology practices grew in size throughout the 1990 to 2007 period. In general, changes were more rapid in 1990 to 2000 than since. The most conspicuous growth was in practices with 30 radiologists or more. This category almost quadrupled its share of radiologists. In contrast, the share of very small practices (1-4 radiologists) declined relatively little, by only approximately one-fourth.
Long optical path cell for photochemical kinetics in heterogeneous systems of low concentration

Previous work from this laboratory on heterogeneous chemical reactions such as those of black carbon with gaseous species of atmospheric interest (ozone and oxides of nitrogen or sulfur) and the photodegradation of polymers has been carried out under ordinary laboratory conditions of concentration, temperature, and pressure in cells, which have been designed to interface with a spectrometer.
Precision DSN radiometer systems: impact on microwave calibrations

The NASA Deep Space Network (DSN) has a long history of providing large parabolic dish antennas with precision surfaces, low-loss feeds, and ultra-low noise amplifiers for deep-space telecommunications. To realize the benefits of high sensitivity, it is important that receiving systems are accurately calibrated and monitored to maintain peak performance. A method is described to measure system performance and to calibrate the receiving system using procedures, software, and commercial instruments that are easy to implement and efficient to use. The utility of the measurement procedures and the precision of the receiver calibration technique were demonstrated by performing tests at Ka-band (32 and 33.68 GHz) frequencies at Goldstone on a 34-m beam-waveguide antenna. Observations of multiple calibration radio sources are used to measure the dependence of antenna gain and system noise temperature on source elevation and derive the performance parameters. The experimental results described illustrate some of the ways that receiving system nonlinearity can negatively impact system performance. A simple radiometer calibration technique and analysis provide quantitative information that enables the system engineer to adjust and linearize the receiving system. When that is not practical, the experimenter or the operator can apply connection coefficients to the measured values of system noise temperature and thereby compensate for the receiving system nonlinearity. >
Growth of the mandible after replacement of the mandibular condyle: an experimental investigation in Macaca mulatta.

Purpose: The study goal was to investigate growth of the mandible after temporomandibular joint reconstruction in juvenile monkeys. Materials and Methods: Sixteen juvenile monkeys (Macaca mulatta) were used as experiment subjects. Animals were equally divided into 4 experimental groups based on the method of temporomandibular joint reconstruction after bilateral condylar excision via extraoral vertical ramus osteotomies. Group Condyle animals had their condylar segments immediately replaced to serve as surgical controls. Group Bone animals were reconstructed with a bony strut. Group sternoclavicular joint (SCJ) animals were reconstructed with the sternal end of their clavicles. Group costochondral junction (CCJ) animals were reconstructed with costochondral junction of ribs. Standardized lateral cephalometric radiographs with the aid of tantalum bone markers were used to evaluate mandibular growth. Twenty animals were used as controls and were allowed to grow undisturbed for an 18-month period (Group Control). Results: All animals showed good mandibular function and a Class I molar relationship after an 18-month follow-up period. Statistical and graphic comparisons showed no significant difference in mandibular growth among any of the groups. Conclusions: The results of this investigation suggest that, within the limits of this model, the choice of autograft for condyle replacement may be irrelevant. © 2002 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 60:1461-1470, 2002
Laboratory Simulation of Ionospheric Double-Layers

A mechanism for double-layer formation in partially- or fully-ionized plasmas is described, founded on beam-plasma interaction: rf growth along the beam excites a rectified, ponderomotive electric field, which in turn causes charge separation. Laboratory studies of the mechanism are described.
Comparing rates of retinal nerve fibre layer loss with GDxECC using different methods of visual-field progression

Background This prospective analysis was designed to examine the rate of RNFL loss using scanning laser polarimetry (GDx enhanced corneal compensation (GDxECC)) in progressing versus non-progressing eyes using various methods to define functional progression. Methods Glaucoma suspect and glaucomatous eyes with ≥3 years of follow-up participating in the Advanced Imaging for Glaucoma Study were enrolled. All eyes underwent standard automated perimetry (SAP) and GDxECC imaging every 6 months. The annual rate of RNFL loss with GDxECC was calculated using linear regression analysis. Functional progression was determined using the Early Manifest Glaucoma Trial (EMGT) criterion, SAP Visual Field Index (VFI) and Progressor software. Results Fifty-three eyes (30 glaucoma suspect, 23 glaucoma) of 53 patients (mean age 64.5±10.7 years, range 42–79) were enrolled. Eighteen eyes (40%) demonstrated SAP progression during the follow-up period using the Progressor criterion, 10 eyes (18.9%) using the VFI criterion, and 3 eyes (5.7%) using the EMGT criterion. The annual rate (μm/year) of mean RNFL loss was significantly greater (p Conclusion Despite differences in the criteria used to judge functional progression, progressing eyes have a significantly greater rate of RNFL loss measured using GDxECC as compared with non-progressing eyes.
Bridging the gap between digital circuits and microprocessors

Most electrical and computer engineering students understand digital circuits and microprocessors, but fail to appreciate that a microprocessor is just a complex finite state machine. The authors present a three experiment sequence which takes the students from the design of a simple EEPROM-based finite state machine through a two-chip microsequencer to a 4-bit central processing unit (CPU). >
Subspace Partitioning for Target Detection and Identification

Detection of a given target or set of targets from observed data is a problem countered in many applications. Regardless of the algorithm selected, detection performance can be severely degraded when the subspace defined by the target data set is singular or ill conditioned. High correlations between target components and their linear combinations lead to false positives and misidentifications, especially for subspace-based detectors. In this paper, we propose a subspace partitioning scheme that allows for detection to be performed in a number of better conditioned subspaces instead of the original subspace. The proposed technique is applied to Raman spectroscopic data analysis. Through both simulation and experimental results, we demonstrate the improvement in the overall detection performance when using the proposed subspace partitioning scheme in conjunction with several subspace detection methods that are commonly used in practice.
Hepatocyte Proliferation is the Possible Mechanism for the Transient Decrease in Liver Injury During Steatosis Stage of Alcoholic Liver Disease

Steatosis is a frequent pathologic stage in alcoholic liver disease (ALD). Although the mechanisms for increased susceptibility of steatotic liver to injury have been postulated, the ability of these hepatocytes to proliferate and withstand injury is unknown. There are conflicting reports on the status of hepatocyte regeneration following chronic alcohol ingestion. Hence, the objective of this study was to investigate the temporal dynamics between the pattern of liver injury and hepatocyte proliferation during the steatosis stage of ALD. Alcoholic steatosis was induced in male Sprague-Dawley rats by feeding an ethanol (EtOH)-containing Lieber-DeCarli liquid diet for a period of 5 weeks. Microvesicular steatosis was evident in H&E sections by three weeks in the EtOH-treated rats, which further developed into panlobular macrovesicular steatosis by 5 weeks. Plasma transaminase activities indicated progressive increase in liver injury peaking at 3 weeks with significant but mild decrease at 4 and 5 weeks. CYP2E1 protein and activity was significantly increased in EtOH-fed rats as measured by Western blot and pNP hydroxylation assay. PCNA analysis of liver sections indicated that EtOH-treated rats had a significantly higher number of cells in S phase of cell division at weeks 1 (3.20 +/- 0.19), 2 (7.03 +/- 0.92), and 3 (4.23 +/- 1.41) when compared to controls (1.5 +/- 0.22). NF-kappaB DNA binding and Cyclin D1 proteins increased significantly in the EtOH-treated rats corresponding with enhanced hepatic proliferation. These data suggest the transient decline in liver injury during alcoholic steatosis is due to enhanced NF-kappaB-dependent hepatocyte proliferation.
Per-Core DVFS With Switched-Capacitor Converters for Energy Efficiency in Manycore Processors

Integrating multiple power converters on-chip improves energy efficiency of manycore architectures. Switched-capacitor (SC) dc-dc converters are compatible with conventional CMOS processes, but traditional implementations suffer from limited conversion efficiency. We propose a dynamic voltage and frequency scaling scheme with SC converters that achieves high converter efficiency by allowing the output voltage to ripple and having the processor core frequency track the ripple. Minimum core energy is achieved by hopping between different converter modes and tuning body-bias voltages. A multicore processor model based on a 28-nm technology shows conversion efficiencies of 90% along with over 25% improvement in the overall chip energy efficiency.
Logic, Research and the Married College Student

What is the relationship between the campus activity program and the married college student? Research and logic were the tools used to conduct the review and to formulate the conclusions and recommendations presented. Research indicated that married students participate in college activities at a minimal level; however, the needs of the country, the goals of higher education, and the philosophy of student personnel work dictate the desirability of increasing their social and cultural maturity. Student personnel workers must, then, find the necessary time, effort, and money needed to obviate the problem. Suggested guidelines include: (a) surveying of the situation on a given campus; (b) allocating necessary funds and staff for a separate activity program for married students; (c) initiating social programs at grass-roots level; and (d) identifying the most likely source of participants and workers.
Current Gain of an AlGaN/GaN Heterojunction Bipolar Transistor

A novel hybrid model and simulation results for an advanced, graded base AlGaN/GaN heterojunction bipolar transistor structure are presented. The base of the n-p-n HBT examined has two parts, a linearly graded AlGaN layer on the emitter side and a heavily p-doped GaN layer on the collector side. In the hybrid model developed here the potential profile is first calculated self-consistently in the biased state taking into account ionized impurity charges, polarization charges, and majority carrier charges. The minority carrier transport is examined subsequently. Injection of electrons from the emitter is modeled as a thermionic emission process. The minority electron transport process in the graded region is drift-dominated due to the large built-in effective field strength. In the low-field GaN layer of the base, electron transport is assumed to be diffusion-dominated. High-level injection effects are modeled in the framework of the Gummel-Poon model. Example structure design parameters are presented and it is found that the calculated current gain can be greater than 25, with a collector current density of 10 4A/cm 2.
Autobiography and liminality: Which story does Charlotte Perkins Gilman choose to tell?

(1991). Autobiography and liminality: Which story does Charlotte Perkins Gilman choose to tell? Women's Studies: Vol. 20, Women's Autobiographies, pp. 37-49.
Voltage-Dependent Sodium Channels Are Expressed in Nonspiking Retinal Bipolar Neurons

Retinal bipolar neurons transmit visual information by means of graded synaptic potentials that spread to the synaptic terminal without sodium-dependent action potentials. Although action potentials are not involved, voltage-dependent sodium channels may enhance subthreshold depolarizing potentials in the dendrites and soma of bipolar cells, as they do in other CNS neurons. We report here that voltage-dependent sodium currents are observed in a subset of bipolar neurons from goldfish retina. Single-cell reverse transcriptase-PCR identified four different sodium channel α subunits in goldfish bipolar cells, putatively corresponding to the mammalian voltage-gated sodium channels Nav1.1, Nav1.2, Nav1.3, and Nav1.6. The amount of sodium current was largest in cells with smaller synaptic terminals, which probably represent cone bipolar cells. Localization of sodium channel immunoreactivity in goldfish retina confirmed the expression of voltage-gated sodium channels in cone bipolar cells of both ON and OFF types. Both immunocytochemical and physiological evidence suggests that the sodium channels are localized to the soma and dendrites where they may play a role in transmission of synaptic signals, particularly in the long, thin dendrites of cone bipolar cells.
Provision of a public good with multiple dynasties

Carbon emissions create externalities across countries and generations. These externalities depend on the degree of contemporaneous cooperation and intergenerational altruism. I study the relative importance of these features, in determining equilibrium climate policy, by imbedding an OLG framework with intergenerational altruism into a differential game among dynasties, each representing a coalition of nations. There is an isomorphism between pure and paternalistic altruism. I illustrate the multiplicity of equilibria using an analytic “linear in state” model. Equilibrium steady states are more sensitive to small changes in cooperation than altruism. Consideration of large changes in altruism and cooperation can reverse this ranking.
On the Robustness of Kernel Density M-Estimators

We analyze a method for nonparametric density estimation that exhibits robustness to contamination of the training sample. This method achieves robustness by combining a traditional kernel density estimator (KDE) with ideas from classical M-estimation. The KDE based on a Gaussian kernel is interpreted as a sample mean in the associated reproducing kernel Hilbert space (RKHS). This mean is estimated robustly through the use of a robust loss, yielding the so-called robust kernel density estimator (RKDE). This robust sample mean can be found via a kernelized iteratively re-weighted least squares (IR-WLS) algorithm. Our contributions are summarized as follows. First, we present a representer theorem for the RKDE, which gives an insight into the robustness of the RKDE. Second, we provide necessary and sufficient conditions for kernel IRWLS to converge to the global minimizer, in the Gaussian RKHS, of the objective function defining the RKDE. Third, characterize and provide a method for computing the influence function associated with the RKDE. Fourth, we illustrate the robustness of the RKDE through experiments on several data sets.
Excitation Transport in Naphthalene Aggregates: Mixed Crystals, Amorphous Thin Films and Polymeric Glasses

There is much interest in the phenomena and mechanisms of energy transport (ET) in molecular aggregates — from basic solid-state considerations (diffusion, percolation, Anderson transition)[l] to photosynthesis and luminescent solar concentrators[2]. ET can also be used for the characterization of molecular aggregates — in mixed crystals, polymeric glasses, thin films and biomembranes.
Private Action and Social Consequence: Coase, Pigou and the Limit of Firms

The substance of value, whether in private negotiations, responding to incentives, reacting to market forces or calibrating government action, is dependent on the perception of that value. If private actions are to be influenced to curtail negative social consequences, this perception must not only be understood in and of itself. This perception must be understood as a communicative network of perceiver and perceived, of private actor and government, of private action and social consequence. It is not just in the being-but the perceiving-that matters.
Evaluation of Three Refurbished Guralp CMG-3TB Seismometers

The overall objective of testing the Guralp CMG-3TB refurbished seismometers is to determine whether or not the refurbished sensors exhibit better data quality and require less maintenance when deployed than the original Guralp CMG-3TBs. SNL will test these 3 refurbished Guralps to verify performance specifications. The specifications that will be evaluated are sensitivity, bandwidth, self-noise, output impedance, clip-level, dynamic range over application passband, verify mathematical response and calibration response parameters for amplitude and phase.