cssi/SciSciGPT-SciSciNet huggingface dataset:
Utility of dual phase liver CT for metastatic melanoma staging and surveillance.

Abstract Rationale and objectives To evaluate the clinical utility of dual phase computed tomography (CT) for assessment of hepatic metastases in patients with metastatic melanoma. Materials and methods A retrospective case–control study of dual phase CT examinations consisting of late hepatic arterial and portal venous phases performed on patients with melanoma was undertaken. In 2010, 420 dual phase CT examinations were performed on 188 patients. Of these, 46 CT examinations on 24 patients with hepatic metastases were combined with 52 control studies for evaluation. Two blinded reviewers independently evaluated single portal venous phase alone and dual phase imaging on separate occasions. The presence of hepatic lesions, the conspicuity of the lesions, and the likelihood that the detected lesions were metastases was recorded. Agreement between readers, sensitivity and specificity was calculated. Results In no case was hepatic metastatic disease only apparent on arterial phase imaging. Arterially enhancing hepatic lesions only visible on the arterial phase or much more conspicuous on the arterial phase were present in 10 studies (10%), all of which were benign. Liver metastases were rated as being more accurately assessed on the portal venous phase in up to 100%. In a per scan analysis dual phase and venous phase imaging had similar sensitivities of 96% (95%, CI: 86–100) and 98% (95%, CI: 89–100), respectively. Conclusion Single portal venous phase imaging is adequate for staging and surveillance in patients with metastatic melanoma.
Copper glutarate coordination polymers with dipyridylamide ligands: Effect of donor disposition and steric bulk on structure

Abstract A structurally diverse series of divalent copper glutarate coordination polymers incorporating dipyridylamide ligands has been prepared and structurally characterized. {[Cu2(glu)2(3-pina)]·3.5H2O}n (1, glu = glutarate, 3-pina = 3-pyridylisonicotinamide) manifests a 3D pcu network constructed from [Cu(glu)]n layers containing {Cu2(OCO)4} paddlewheel dimers. Increasing the steric bulk of the glutarate ligand afforded [Cu2(dmg)2(3-pina)]n (2, dmg = 3,3-dimethylglutarate), which shows a (4,4) grid structure based on linked [Cu(dmg)]n chains containing similar {Cu2(OCO)4} paddlewheel dimers. {[Cu(glu)(3-pna)(H2O)]·H2O}n (3, 3-pna = 3-pyridylnicotinamide) has a simple (4,4) grid-like layer structure with isolated copper atoms, while {[Cu(glu)(4-pna)(H2O)]·H2O}n (4, 4-pna = 4-pyridylnicotinamide) possesses a 2-fold parallel interpenetrated (6,3) herringbone lattice. Increased steric bulk and counterion inclusion in [Cu3(Hmg)2(4-pna)4(SO4)2(H2O)4]n (5, meg = 2-methylglutarate) results in a 1D ribbon structure. Thermal properties are also investigated.
Structure and ion transport in polymer-salt complexes

Abstract Polymer electrolytes based on alkali metal complexes of polyethers and cross-linked polyethers have significant cation mobility, which appears to arise from large-amplitude motions of the polymer. High chain flexibility not only promotes ion transport but it also is important for the initial formation of polymer-salt complexes. Several new polymer electrolyte systems are discussed which contain flexible polymer backbones and high concentrations of polar groups.
A computerized biomechanical model-development of and use in studying gross body actions.

Gross body actions involved in heavy industry. e.g. lifting and carrying materials. are often the cause of injury to the musculoskeletal system. A computer model is developed which treats the human body as a series of seven links from which reactive forces and torques are computed at each articulation during various simulated materials handling tasks. In addition, an analysis of shearing and compressing forces at the lower lumbar spine is included. The assumptions of the present model are presented, along with a discussion of future models. IT HAS been reported by Troup (1965) that a relatively large portion of industrial injuries (as great as 12 per cent) are back disorders resulting from a lifting task. It is also evident from papers by Tichauer (1965), Raof et al. (1960) and Davis et al. (1965) that the estimation of stresses on various parts of the musculoskeletal system during lifting activities will require a complex methodology which takes account of such factors as (1) instan- taneous positions of the extremities and trunk, (2) curvature changes in the spine, (3) strength variations within different muscle groups and people, and (4) abdominal pressure effects.
Surface-tension properties of some polydispersed alkyl-substituted polyoxyethylated phenylsulfonamides

Twenty-nine laboratory-prepared polydisperse nonionic surfactants, derived from polyoxyethylatedN-alkylphenylsulfonamides [RϕSO2 N(R′) (EO)nH], have been characterized. EO is ethyoxylation;R is hydrogen,n-butyl ort-butyl;R′ is hexyl, octyl, or decyl; and (EO)n is varied from (EO)4 to (EO)20. Surface tension in aqueous solution was studied. The critical micelle concentration, surface excess, minimum area per molecule, effectiveness of surface-tension reduction, and free energy of micelle formation were calculated from the surface-tension measurements. The critical micelle concentrations for the derivatives in whichR′-hexyl were considerably higher than the corresponding derivatives whereR′ is octyl or decyl. The greatest surface-tension reduction was found in theR′=n-octyl derivatives whereR ist-butyl with (EO)9 orn-butyl with (EO)11.
A review of advances in high-temperature corrosion☆

Abstract The current understanding of selective oxidation is discussed. The transition from internal to external oxidation of binary alloys and the effects of transient oxidation and third element additions are considered. It is shown that the classic approach for calculating the critical solute content to form an external scale must be modified when applied to systems in which the thermodynamic stability of the lowest oxide of the matrix element approaches that of the solute oxide and/or the oxygen permeability in the alloy becomes very small. These conditions are pertinent to the oxidation of many intermetallic compounds. The results of recent studies of stress generation and relief in oxide scales and on oxide adherence are briefly reviewed. Emphasis is placed on the effects of minor elements such as the noble metals and “oxygen-active elements”. The effects of second oxidants (e.g. sulfur, carbon, nitrogen etc.) on the selective oxidation process are discussed. It is shown that the presence of a second oxidant can retard the formation of a protective oxide film in certain alloy systems. Additionally, the influence of a second oxidant on the breakdown of previously formed protective oxide films is discussed. Finally, recent developments in the understanding of the hot corrosion of alloys, particularly alumina-forming coatings, are reviewed. The effects of deposit composition, atmosphere composition, and temperature on the initiation and propagation of hot corrosion degradation are included in this discussion.
Development of a controller to provide primary frequency response capability for a wind farm

Given the continuously growing contribution of renewable resources to energy generation, the operation of these renewable resources, such as Wind Turbine Generators (WTGs) and their response to disturbances or other changing conditions on the power system has a very significant impact on system operation and performance. These concerns will continue to grow in importance as the amount of wind generation increases. Independent System Operators around the world are starting to look for this type of renewable resource to provide primary frequency response capability to help ensure safe and reliable power grid operations. Using a wind farm configuration loosely based on an actual wind farm, this paper investigates the effectiveness of a wind farm to supply primary frequency response capability, that is, to adjust its power output in response to a change in system frequency. The controller structure demonstrated is a general purpose controller that interfaces with the park controller(s) so it could be applied to wind farms with any type of turbines including vintage ones where manufacturers supplied advanced frequency control features may not be available. This control logic has been applied at a large wind farm in Texas and has been operating successfully for over a year.
The E- and D-region in IRI

Abstract The International Reference Ionosphere provides a representation of the electron density and the ion composition in the E- and D-region (from 60 km upward) based on measurements from the ground (ionosonde, incoherent scatter) and from rockets. We will review the current status of the IRI E- and D-region models and discuss recent improvements and plans for future updates. Shortcomings and limits of the present description will be pointed out and the need for more measurements will be stressed. We will also discuss other venues of model improvement, e.g., results from theoretical models and input of measured characteristic parameters (E peak, D ledge).
Predictors of organ damage in systemic lupus erythematosus: The Hopkins Lupus Cohort

Objective The Systemic Lupus International Collaborating Clinics/American College of Rheumatology (ACR) Damage Index (SDI) is the accepted measure of permanent organ damage in systemic lupus erythematosus (SLE). We analyzed data from a large SLE cohort to identify variables associated with rates of damage accrual as measured by the SDI. Methods The study included 2,054 SLE patients (92% female, 56% white, and 37% African American) with a mean age at diagnosis of 33 years. The SDI score was calculated retrospectively at the time of cohort entry and prospectively during followup. The relationships between time-invariant patient characteristics and rates of damage accrual were assessed based on the damage score at the last available followup visit. The relationships between time-varying patient characteristics and damage accrual were assessed based on the timing of damage accrual during cohort participation. Results Overall, the SDI score increased at a rate of 0.13 per year. Higher rates of damage were observed for those who were older, male, or African American, had a lower income or education level, were hypertensive, were positive for lupus anticoagulant, or had proteinuria. During followup, the risk of damage was higher for those who were older, had more disease activity, had low complement levels, were positive for anti–double-stranded DNA, satisfied more ACR criteria for SLE, or were receiving corticosteroids. Lower risk was observed among patients receiving hydroxychloroquine. After adjustment for other variables, age, hypertension, and corticosteroid use emerged as the most important predictors of damage accrual. Conclusion Our findings indicate that rates of damage vary in demographic subgroups, but much variation appears to be explained by hypertension and corticosteroid use. These data clearly point to the need for tight control of disease activity without reliance on corticosteroids.
H7N9 and Other Pathogenic Avian Influenza Viruses Elicit a Three-Pronged Transcriptomic Signature That Is Reminiscent of 1918 Influenza Virus and Is Associated with Lethal Outcome in Mice

ABSTRACT Modulating the host response is a promising approach to treating influenza, caused by a virus whose pathogenesis is determined in part by the reaction it elicits within the host. Though the pathogenicity of emerging H7N9 influenza virus in several animal models has been reported, these studies have not included a detailed characterization of the host response following infection. Therefore, we characterized the transcriptomic response of BALB/c mice infected with H7N9 (A/Anhui/01/2013) virus and compared it to the responses induced by H5N1 (A/Vietnam/1203/2004), H7N7 (A/Netherlands/219/2003), and pandemic 2009 H1N1 (A/Mexico/4482/2009) influenza viruses. We found that responses to the H7 subtype viruses were intermediate to those elicited by H5N1 and pdm09H1N1 early in infection but that they evolved to resemble the H5N1 response as infection progressed. H5N1, H7N7, and H7N9 viruses were pathogenic in mice, and this pathogenicity correlated with increased transcription of cytokine response genes and decreased transcription of lipid metabolism and coagulation signaling genes. This three-pronged transcriptomic signature was observed in mice infected with pathogenic H1N1 strains such as the 1918 virus, indicating that it may be predictive of pathogenicity across multiple influenza virus strains. Finally, we used host transcriptomic profiling to computationally predict drugs that reverse the host response to H7N9 infection, and we identified six FDA-approved drugs that could potentially be repurposed to treat H7N9 and other pathogenic influenza viruses. IMPORTANCE Emerging avian influenza viruses are of global concern because the human population is immunologically naive to them. Current influenza drugs target viral molecules, but the high mutation rate of influenza viruses eventually leads to the development of antiviral resistance. As the host evolves far more slowly than the virus, and influenza pathogenesis is determined in part by the host response, targeting the host response is a promising approach to treating influenza. Here we characterize the host transcriptomic response to emerging H7N9 influenza virus and compare it with the responses to H7N7, H5N1, and pdm09H1N1. All three avian viruses were pathogenic in mice and elicited a transcriptomic signature that also occurs in response to the legendary 1918 influenza virus. Our work identifies host responses that could be targeted to treat severe H7N9 influenza and identifies six FDA-approved drugs that could potentially be repurposed as H7N9 influenza therapeutics.
Stratified Flow over Extended Obstacles and Its Application to Topographical Effect on Vertical Wind Shear

Abstract An investigation is made of the two-dimensional flow of a stratified fluid over an extended obstacle, characterized by a source disturbance, for an infinite medium and for a layer of finite depth. The problems are posed as initial-boundary value problems, and steady-state solutions for the flow field are obtained in the limit of large time. The results show an unattenuated system of jets or shear layers extending far upstream from the obstacle, which occurs whenever a system of lee waves is present. For the finite depth case detailed calculations are made, starting with realistic mean values for the atmosphere. The final established profile indicates a variable shear and density profile far upstream, characterized by variable local Richardson numbers. The wind shears induced are also of the order of shears due to thermal wind effects, though quite apart from these effects. The study therefore points to the importance of topographical features on vertical wind shear in the troposphere.
Expression of the β-glucuronidase gene under the control of the CaMV 35S promoter in Schizosaccharomyces pombe

We have transformed Schizosaccharomyces pombe with the β-glucuronidase (GUS) gene from Escherichia coli under the control of the plant cauliflower mosaic virus (CaMV) 35S promoter element. Efficient expression of GUS enzyme was observed. Moreover, transcription initiated at a unique site identical to that used in plant cells.
A relation between the dark mass of elliptical galaxies and their shape

We have studied a large number of elliptical galaxies and found a correlation between their dark matter content and the ellipticity of their visible shape. The galaxies were strictly selected so that only typical medium-size elliptical galaxies were considered. Galaxies with unusual characteristics were rejected to minimize point-to-point data scatter and avoid systematic biases. Data from six different techniques of extracting the galactic dark matter content were used to avoid methodological biases. A thorough investigation of the interrelation between attributes of elliptical galaxies was carried out to assess whether the correlation originates from an observational bias, but no such origin could be identified. At face value, the correlation found implies that at equal luminosities, rounder medium-size elliptical galaxies appear to contain less dark matter than flatter elliptical galaxies, e.g. the rounder galaxies are on average four times less massive than the flatter ones. This is puzzling in the context of the conventional model of cosmological structure formation.
LABORATORY STUDY OF FEASIBILITY OF STABILIZING ZINC CLINKER AND ROAD MILLINGS TO PRODUCE LOW-PERMEABILITY PAVEMENT MATERIAL

An international mining company has funded research to develop a lowpermeability pavement material by stabilizing on-site waste materials (zinc clinker and road millings) at a zinc processing plant in the mid-western United States. The need for development of this material has arisen from concerns of the state environmental protection agency (EPA) that rain is leaching zinc from stockpiles of clinker, thereby contaminating the surface soils, drainage ditches, and groundwater on the site. The desired engineering properties of the stabilized material are as follows: (a) the material must have sufficiently low permeability to act as an "impermeable" liner, (b) the material must bind the zinc to the clinker so that it does not leach out, and (c) the material must be stiff and strong enough to serve as a pavement base course and wearing surface. Laboratory tests were conducted with various stabilized combinations of asphaltic road millings, zinc clinker, and local clay from a zinc processing plant in the midwe...
PSAR: Predictive space aggregated regression and its application in valvular heart disease classification

This paper presents a predictive space aggregated regression based boosting algorithm, and its application in classifying the Continuous Wave(CW) Flow Doppler image data set with the diseases of stenosis and regurgitation in mitral and aortic valves. The proposed algorithm involves finding a way to simultaneously combine all the weak learners based on a well-justified assumption as in the previous work[1] that not only the weak learners but each training sample should have different contributions toward learning the final strong hypothesis. However, the proposed algorithm greatly improves on the previous method by (1) dramatically reducing the number of combination weights, leading to a more stable numerical solution, (2) having regularization in both data and predictive spaces to reduce the generalization error of the model, and (3) using the sparse weight selection scheme in the testing to further avoid overfitting. A sparse subset of the training data is chosen to best approximate the test sample, and the final hypothesis is constructed based only on the chosen training samples and associated weak learner weights. Finally, we empirically show that the proposed technique not only successfully solves the overfitting problem but also significantly increases the performance of the weak classifiers via a set of comparison experiments on the CW Flow Doppler image data set consisting of 4 types of valvular diseases at different severity levels.
Do Corals Lie About Their Age? Some Demographic Consequences of Partial Mortality, Fission, and Fusion

Population dynamics of corals and other colonial animals are complicated by their modular construction and growth. Partial colony mortality, colony fission, and colony fusion distort any simple relationship between size and age among reef corals.
Family history of diabetes mellitus and oral glucose tolerance testing criteria.

A review of 185 obstetrical patients, having a family history of diabetes mellitus without medical history of glucose intolerance in the non-pregnant state was conducted. A 3-hour 100-g oral glucose tolerance test was performed on all patients between 20 and 34 weeks of gestation. According to O'Sullivan's criteria for glucose tolerance testing, normal glucose tolerance occurred in 89.7%, while Class A diabetes was identified in 10.3% of patients tested. 3.8% of the study population fulfilled the O'Sullivan criteria for abnormal glucose intolerance and required insulin treatment during pregnancy.The Division of Perinatal Medicine at Duke University has traditionally defined the abnormal glucose tolerance test at glucose values lower than O'Sullivan's internationally accepted criteria. An intermediate group, having abnormal glucose values according to the Duke criteria, was classified as “Carbohydriate Intolerance”, comprised 32.4% of the patients tested and were managed identically to O'Sullivan Class A D...
PARATHYROID HORMONE (PTH) AND Na 2 CaEDTA (EDTA): THEIR EFFECTS ON BONE LEAD (pb), CALCIUM (Ca) AND HYDROXYPROLINE (HOP) IN BONE ORGAN CULTURE

Bone is the primary reservoir of Pb and the major source of Pb chelation by EDTA. To define further the interactions of Pb with bone mineral and matrix, the effects of EDTA and PTH have been compared in bone organ culture. Pregnant rats were intoxicated with Pb (5mg/ml) by adding it to the drinking water. On day 119 of gestation, paired fetal bones were placed on grids in BGJ medium to which either PTH or EDTA were added. After 72 hours in culture, bones were removed, cartilage ends were separated from the shafts of each bone, and concentrations of Pb, Ca and HOP were measured separately for both parts of bone. The results (* p = < .01 vs controls) of bone shafts were: Increasing the concentrations of phosphate in the medium markedly inhibited the actions of both agents; and very little Pb (≤ .08μg) was found in cartilage. These data indicate that EDTA has similar effects on the collagen of bone shafts to PTH. Furthermore, besides its chelation of Pb from bone shafts, EDTA produces solubilization of bone mineral and matrix in vitro.
P. Secchi, S. Vantini and V. Vitelli: Analysis of spatio-temporal mobile phone data: a case study in the metropolitan area of Milan

I thank the authors and the editorial board for inviting me to comment on this work. I would like to congratulate the authors on bringing in a new tool set for the analysis of functional data indexed by spatial locations. Data of this type have been attracting attention of the FDA research community for some time, but the focus has been of functional principal component (FPC) expansions to form a suitable temporal basis. My comments will focus on providing several relevant references to my own research, which are related to this work. Many other researchers have contributed to this field, but I do not aim at a comprehensive review. Delicado et al. (2010) provide a very good review. They review research on geostatistical functional data (focusing on kriging), point processes associated with functional data, and functional areal data. My own work in this area has focused on geostatistical functional data, which can be denoted as X (sk; t), where sk is the spatial location and t is time. Using this notation, the Erlang data can be written as E(xk; t), where the xk are the locations with almost complete records. Gromenko et al. (2012) study the estimation of the mean function μ and the FPC’s v j in the Karhunen–Loeve representation
Artificial dissipation models for hypersonic external flow

Four artificial dissipation models which augment central difference schemes were examined for hypersonic external flows. The models were a first and third order dissipation model, a directionally scaled first and third order dissipation model, a flux limited dissipation model, and a flux difference split dissipation model. Each model was implemented in the lower-upper symmetric-Gauss-Seidel (LU-SGS) algorithm to solve the full Navier-Stokes equations. The latter two models can be regarded as total variation diminishing (TVD) schemes. Test results for model problems showed that the flux limited dissipation model was robust enough to predict a high speed blunt body flow with strong shock and expansion waves. The flux difference split dissipation model was capable of shock capturing with higher resolution, but was less robust. First and third order dissipation models turned out to be neither accurate nor robust enough for high Mach number flow computations.
The Social Construction of Beliefs About Cancer: A Critical Discourse Analysis of Racial Differences in the Popular Press

There is a great disparity between African and Caucasian Americans with regard to frequency of cancer screenings, timely follow-up, and scheduling diagnostic appointments. This study compared popular press articles targeting African Americans with those targeting Caucasian Americans in an effort to understand how the media, which is often a reflection of the dominant culture, contributes to this disparity. The data were analyzed along three dimensions: comparative descriptive analysis, comparative impact on the reader's beliefs about cancer, and the social control exerted by the political-economic context in which the discourse on cancer occurs. Significant differences were found in many of the parameters. The results demonstrate the importance of considering the influence of the media when targeting healthcare interventions.
Human eosinophils constitutively express nuclear factor of activated T cells p and c

Abstract Background: Eosinophils are now known to produce a variety of proinflammatory cytokines, although the molecular factors that regulate their production are poorly understood. The expression of almost all of the cytokines produced by eosinophils, including the proallergic cytokine IL-4, is now known to be regulated at the level of transcription by members of the nuclear factor of activated T cells (NFAT) family of transcription factors. Objective: We sought to characterize the expression of different NFAT proteins in resting and activated eosinophils. Methods: Nuclear and whole cell extracts were obtained from both peripheral blood eosinophils and those obtained from bronchoalveolar lavage fluid of asthmatic subjects after endobronchial allergen challenge. NFAT expression was determined by using immunoprecipitation and Western blot analysis, DNA-binding assays, and RT-PCR analysis of eosinophil mRNA. Results: Both peripheral blood and bronchoalveolar lavage fluid eosinophils expressed NFATp and NFATc protein. Unlike activated T cells, which express multiple NFATc isoforms, eosinophils preferentially express the approximately 85-kd isoform. In addition, eosinophils were found to constitutively express NFATc mRNA. A brief incubation with the T H 2 cytokines IL-4 and IL-5 was sufficient to induce the nuclear translocation of NFATc. Eosinophil nuclear extracts contain multiple factors that can specifically recognize the IL-4 promoter P1 NFAT site in DNA-binding assays, including NFATp. Conclusion: NFATp and NFATc can regulate the expression of cytokines and other genes in eosinophils but appear to be regulated by a novel signal transduction mechanism in these cells. (J Allergy Clin Immunol 2001;107:143-52.)
Dynamics of the redistribution of 1-dodecylpyrene aggregates in micellar solution

Abstract Injection of 1-dodecylpyrene into sodium dodecyl sulfate micellar solutions at probe: micelle ratios of
Cocaine and depression

High rates of depressive symptoms and suicide have been documented with cocaine abuse. The purpose of this review is to investigate the possible relationship between cocaine use and depression. This article will examine reports investigating the prevalence of depression in cocaine users, critique studies using psychotropic medication to treat either cocaine abuse and/or depression in cocaine abusers, highlight future areas of research, and offer a unifying hypothesis to explain the disparate findings of affective symptomatology in this population of substance abusers. Depression 1:235–249 (1993). © 1993 Wiley-Liss, Inc.
The Relationship Between Falls and Psychological Well-Being in a Brazilian Community Sample

In Brazil and in the United States, one in three older adults fall each year. Falling can lead to devastating outcomes for older adults, their families and health care systems. Research has identified many risk factors for falls, including physical and environmental hazards. However, less research has addressed the relationship between psychological well-being and falls, when the focus has usually been fear of falling and depression. Using a secondary dataset we tested the relationship between psychological well-being and falls in community dwelling older adults from the state of Rio Grande do Sul, Brazil. Analysis was conducted using logistic regression. Findings show that most of the psychological well-being variables are predictors of falls. Advanced age and not feeling calm and relaxed were the variables that showed more chances involved with falling. These research findings are important to increase the existing knowledge about falls in Brazil and provide information for professionals working in fall prevention.
Cracking and damage mechanisms in ceramic/metal multilayers

Abstract Investigations of cracking in multilayered ceramic/metal composites are presented. Two aspects are considered: crack renucleation across intact single metal layers and subsequent crack extension. Crack renucleation criteria are determined and compared with predictions. High-resolution strain-mapping techniques are employed to determine the surface strain fields surrounding cracks. Good agreement is found between these experimental measurements and the predictions of a small-scale yielding model. Subsequent crack progression occurs either by the extension of a dominant, nearly planar crack or by the formation of a zone of periodically spaced cracks. Both patterns are analyzed. The dominant cracking behavior is found to depend on the volume fraction and yield strength of the metal.
Uncertainty Functions with a Constant Rate of Reduction and Comparison of Experiments

Abstract It is proved that an uncertainty function is a geometric mean if and only if the rate of reduction of uncertainty is independent of the prior distribution.
Regulatory drinking: Do the physiological substrates have an ecological niche?

Abstract The current physiological theories of thirst are briefly reviewed, and a number of experiments in which drinking behavior does not conform to such models are described. These include parenteral self-administration and taste adulteration experiments. Regulatory drinking may be identified in these preparations, but is substantially different from that defined by simple physiological models. Similarly aberrant regulatory drinking is seen after a variety of hypothalamic lesions, and the interpretation of such experiments is discussed. Finally, the relevance of some laboratory paradigms to the normal (ethologically determined) controls of drinking is questioned, and it is suggested such factors should be incorporated into future models.
The Effect of Microenterprise Lending on Child Schooling in Guatemala

Many recent theoretical models which portray human capital investment as a primary engine of economic growth underemphasize the structure of the microeconomic decision-making process which gives rise to human capital investment. In both developed and developing countries human capital investment tends to be a household-level decision made in the form of child schooling. For families in developing countries which operate household enterprises the decision involves an economic trade-off between future returns to schooling and the current return to childrens labor in the enterprise. The author explores how access to credit in developing countries can affect the child schooling decision. A 2-period household model is presented which endogenously generates an optimal level of child schooling by households accounting for the possibility of asymmetric information in credit and labor markets. Comparative statics are then conducted to show the conditions under which child schooling will increase or decrease when credit constraints are relaxed. A brief background of the schooling system in Guatemala and a brief description of the survey data collected in Guatemala are provided followed by the presentation of empirical tests and a summary of empirical findings with suggestions made for further research.
Apparatus for low-energy X-ray fluorescence using an Al K X-ray source and an Si(Li) detector

The concept, design, characterization and operation of an apparatus for low-energy x-ray fluorescence are described. This system utilizes commercially available components in a novel arrangement. An Al K x-ray source, an ultra-thin-windowed Si(Li) detector and an ion gun for sputter cleaning were combined to perform analyses for elements with atomic number Z ⩾ 6. Pairs of slit collimators placed between the specimen and the x-ray detector defined the area analyzed. The system configuration permitted analyses over areas with a variety of dimensions (0.4–22 mm). Distinction between surface and bulk signals was possible using the sputter-cleaning capability.
Effects of ambient illumination and image color balance on the perception of neutral in hybrid image display systems

This paper describes a visual experiment in which a group of observers made forced choice judgments of the location of neutral in test images presented on a color CRT display and photographic reflection prints. The CRT and photographic images were presented both separately and side-by-side in a simulated office environment under two conditions of ambient illumination, tungsten and daylight fluorescent. The results indicate that an observer's state of chromatic adaptation during image viewing is mainly dependent on image areas with little or no dependence upon the surrounding environment. With reflection images viewed in normal conditions, observers were noted to automatically discount ambient illumination. When viewing self-luminous images however, observers formed relative judgements only under certain conditions. These results are discussed in terms of their use in choosing white points for color reproduction calculations.
Optical absorption spectrum of Ce@C82

Optical absorption spectrum for the Ce@C82 endohedral fullerene has been studied using the density-functional theory and the many-body Green's-function approaches. The geometry optimization was performed using the DMol3 software. A plane wave approach as implemented in the ABINIT package has been used to solve the Kohn-Sham equation. Self-energy was evaluated by the GW approximation. Finally the optical absorption spectra have been calculated using the random phase approximation (RPA), RPA plus self-energy correction (RPA-GW) and the Bethe-Salpeter equation (BSE-GW).
Fiber array fabrication technique for 15-μm-diameter single-mode fibers

We describe a technique to package 15-μm-diam single-mode fibers on a silicon substrate that can be incorporated into an endoscopic probe tip. The single-mode fibers in the array can be used in coherent imaging applications such as optical coherence tomography. Fiber-to-substrate and fiber-to-fiber coupling effects are studied using beam propagation techniques to determine the different design characteristics and the maximum length of the reduced diameter fiber that can be packaged in the probe tip. Single-mode fibers are etched to reduce the cladding diameter from 125 to 15 μm. A 2-μm-thick silica layer is grown in the silicon substrate to minimize the fiber-substrate coupling. Reduced diameter fibers are placed into a 5-mm by 150-μm trench etched in a silicon-silica substrate and fixed with UV curable cement. Active alignment is used to ensure the correct alignment of fibers. The fiber array is experimentally evaluated to test fiber placement accuracy, throughput, and cross talk. Optical coherence tomography images are also obtained with the array.
Isolation of a Stable ansa-Chromocene(III) Carbonyl Cation and Characterization of a Transient, Cationic ansa-Chromocene(IV) Carbonyl Hydride

Protonation of the metal occurs upon reaction of Me4C2(C5H4)2CrCO with [H(Et2O)2][B(3,5-(CF3)2C6H3)4] at −70 °C in thf-d8. The diamagnetic Cr(IV) hydride intermediate was characterized by 1H NMR spectroscopy. Its decomposition to a paramagnetic product mixture upon warming to room temperature is accompanied by the evolution of 0.5 equiv of gas that is 54% H2 and 46% CO. Crystals of the borate salt of the 17e- ansa-chromocenium carbonyl cation [Me4C2(C2H4)2CrCO]+ were isolated from the product mixture for a molecular structure determination.
Variability in study withdrawal rates among academic neuroradiologists participating in a radiology utilization management program.

Purpose The aim of this study was to analyze variability in study withdrawal rates among academic neuroradiologists participating in a utilization management (UM) program. Methods The activities of 5 academic neuroradiologists participating in a UM program were assessed. The project period spanned 42 months. Participating neuroradiologists received identical training and used identical rule sets to evaluate the appropriateness of outpatient CT and MRI studies. Neuroradiologists could approve studies on the basis of available electronic data or contact referring physicians for further information. The rate of withdrawals (defined as "study not performed by consensus" or "study changed by consensus" with the referring physician) was compared among the neuroradiologists. Results A total of 5,256 studies were reviewed (mean, 1,051; median, 1,043). There were 573 studies (10.9%) not performed by consensus and 298 studies (5.7%) changed by consensus, resulting in a total of 871 withdrawals (16.6%). Among the neuroradiologists, withdrawal rates varied by approximately a factor of 2 (mean, 16.5%; median, 15.2%; range, 12.8%-23.5%). Although rate of studies not performed by consensus varied by approximately a factor of 2 (mean, 10.8%; median, 8.1%; range, 7.6%-18.0%), the rate of studies changed by consensus showed little variation (mean, 5.7%; median, 5.5%; range, 4.8%-6.6%). Conclusions Variability in withdrawal rates was related to cases in which referring physicians were asked not to perform studies; there was little variation when referring physicians were asked to change studies. These data imply agreement among the neuroradiologists regarding appropriateness of rule sets but suggest that personality characteristics such as persuasiveness, persistence, and desire for conflict avoidance may play an important role in outcomes.
Diagnosis and treatment of osteoporosis in patients with vertebral compression fractures.

OBJECTIVES: To determine whether patients with vertebral compression fractures are diagnosed with or treated for osteoporosis. DESIGN: Retrospective cohort study. SETTING: Two primary care practices in Massachusetts. PARTICIPANTS: Two hundred six patients with vertebral compression fractures noted on routine radiographs in 1997–1998. MEASUREMENTS: Percentage of patients diagnosed with osteoporosis and treated with prescription medications (estrogen, bisphosphonates, raloxifene, or calcitonin). Factors associated with missed osteoporosis diagnosis and treatment, including risk factors for osteoporosis, comorbidities, vertebral fracture severity, and processes of care communication were also examined. RESULTS: The median patient age was 76, 71% of the cohort was female, and 13% of patients had a history of corticosteroid use. Thirty-eight percent of subjects (46% of women and 19% of men) were diagnosed with osteoporosis and 32% (39% of women and 14% of men) received prescription medications for osteoporosis. Of women who were diagnosed with osteoporosis, 69% received prescription medications. In adjusted analyses women younger than 50 (adjusted odds ratio (AOR) = 0.09; 95% confidence interval (CI) = 0.01–0.71) and 90 and older (AOR = 0.27; 95% CI = 0.08–0.98) were less likely to be diagnosed with osteoporosis, whereas women with a prior hip or radial fracture (AOR = 3.65; 95% CI = 1.28–10.38) or back pain (AOR = 2.84; 95% CI = 1.38–5.85) were more likely to be diagnosed with osteoporosis. CONCLUSIONS: Physicians frequently did not diagnose osteoporosis in primary care patients with vertebral fractures, missing an important preventive opportunity for patients at high risk for future fractures. Efforts targeted to improving diagnosis of osteoporosis could improve patient care.
At-risk mothers' parenting capacity: an epistemological analysis of change through intensive intervention.

Using an epistemological framework, we examine the process of change for two at-risk mothers participating in the Children's Ark, an innovative foster care program. The Children's Ark invited at-risk mothers who had lost custody of their children to live in a structured, supervised environment with their infants/toddlers while receiving intensive intervention. Focusing on two mothers who completed the program and regained custody of their children, we developed a coding system from Women's ways of knowing (Belenky, Clinchy, Goldberger, & Tarule, 1986) to analyze entry and discharge interviews, and as a means of exploring alternative conceptualizations to the helping professions' understanding of at-risk families. In terms of an epistemological framework, we found that mothers increased their capacity to acknowledge their own minds and voices and those of their children. Additionally, mothers came to recognize their capacity to generate knowledge, especially through dialogue and relationships with others. ...
Upstream monopoly, downsteam competition and spatial price discrimination

Abstract Works on spatial competition with discriminatory pricing assume that the input market is competitive or, at least, that upstream input suppliers do not offer price schedules contingent on downstream location decisions. In the present paper it is assumed that an upstream monopoly sets the price of its output based on its observation of the locations chosen by the firms downstream. A complete characteri- zation of a subgame-perfect equilibrium is given. In particular, no equilibrium is efficient. Futhermore, the payoffs of the different firms in an equilibrium, point to an incentive shared by all of them for vertical integration.
Antigen-Loading Compartments for Major Histocompatibility Complex Class II Molecules Continuously Receive Input from Autophagosomes

Major histocompatibility complex (MHC) class II molecules present products of lysosomal proteolysis to CD4+ T cells. Although extracellular antigen uptake is considered to be the main source of MHC class II ligands, a few intracellular antigens have been described to gain access to MHC class II loading after macroautophagy. However, the general relevance and efficacy of this pathway is unknown. Here we demonstrated constitutive autophagosome formation in MHC class II-positive cells, including dendritic, B, and epithelial cells. The autophagosomes continuously fuse with multivesicular MHC class II-loading compartments. This pathway was of functional relevance, because targeting of the influenza matrix protein 1 to autophagosomes via fusion to the autophagosome-associated protein Atg8/LC3 led to strongly enhanced MHC class II presentation to CD4+ T cell clones. We suggest that macroautophagy constitutively and efficiently delivers cytosolic proteins for MHC class II presentation and can be harnessed for improved helper T cell stimulation.
Multiple-Trait Prediction of Transmitting Abilities for Herd Life and Estimation of Economic Weights Using Relative Net Income Adjusted for Opportunity Cost

Abstract Genetic and phenotypic (co)variances among linear type traits, final score, first lactation milk and fat yield, and 84-mo totals for longevity, relative net income, and relative net income adjusted for opportunity cost of postponed replacement were estimated with a multiple-trait sire model. Data were from 433,116 cows in herds participating in the classification program for conformation traits of the Holstein Association of America. Yield information from all cows in classified herds indicated that classified cows are not a random sample. Heritability of net income adjusted for opportunity cost was higher, .17, than unadjusted net income, .12, but the genetic correlation between the estimates of net income was high, .97. Adjusted net income also had high genetic correlations with first lactation milk yield, .80; fat yield, .60; and dairy form, .48. Heritability of longevity (months in milk to 84 mo) was .06. Adjustment of net income for opportunity cost lowered the genetic correlation with longevity from .84 to .70. Evaluation of lifetime merit using traits measured during first lactation with economic weights developed using adjusted net income was more accurate than indirect prediction of longevity; the approximate reliability of a first-crop AI sire for lifetime merit was .65 compared with .42 for longevity.
Synaptic effects of nitric oxide on enkephalinergic, GABAergic, and glutamatergic networks of the rat periaqueductal gray

Previous studies have shown that the injection of nitric oxide (NO) donating compounds into the dorsal periaqueductal gray region of the midbrain (PAG) decreases mean arterial pressure (MAP), while the injection of NO synthase (NOS) inhibitors increases MAP. In this study we used both in-vivo and in-vitro preparations and examined the effect of a NO donor and a NOS inhibitor on MAP, membrane properties, and synaptic activities in PAG neurons. We found that: (1) Injection of the NO donor hydroxylamine (HA) into the dorsal PAG decreased MAP, while the injection of the neuronal NOS (nNOS) inhibitor, 1-(2-trifluoromethylphenyl) imidazole (TRIM) increased MAP. These responses were consistent and site-specific. (2) HA-evoked hypotensive responses were mediated by PAG neuronal activity, because they were blocked by pre-injection with gamma-amino-butyric acid (GABA). (3) HA consistently increased the rate of observable synaptic events while TRIM consistently decreased the rate of observable synaptic events. (4) Bicuculline (BIC) and naloxone (NAL) blocked HA-evoked increases in the rate of observable inhibitory synaptic events. (5) Perfusion with sodium nitroprusside (SNP) and illumination with bright light consistently elevated rates of observable synaptic events, and SNP-evoked increases of excitatory synaptic events were blocked by pretreatment with glutamic acid antagonists. (6) PAG-medullary projecting neurons exhibited similar response patterns. The results of this study suggest that: (1) NO production within the PAG is a major component of PAG-mediated cardiovascular responses. (2) The effects of NO may be mediated in part by increased presynaptic vesicular release of glutamic acid, GABA, and enkephalin.
Proton coupled electron transfer of galvinol in self-assembled monolayers

Abstract Proton coupled electron transfer (PCET) half-reactions play a vital role in a variety of biological and chemical processes. A previous kinetic analysis of proton coupled redox couples on electrodes assumes that electron and proton transfers proceed stepwise and that the transfer coefficient for electron transfer steps remains constant at all overpotentials. This work explores the consequences of the stepwise model with a potential-dependent transfer coefficient using a surface-attached 1-electron/1-proton-redox couple. The potential dependence of the transfer coefficient is based on the Marcus density-of-states model for heterogeneous electron transfer. Galvinol is attached to a self-assembled monolayer on a gold electrode and its voltammetry investigated from pH 2 to 14. The formal potential, standard rate constant and p K a for galvinoxyl/deprotonated galvinol/protonated galvinol are obtained from the pH dependence of the apparent formal potential and apparent standard rate constant. The standard rate constant for galvinoxyl/deprotonated galvinol (5600 s −1 ) suggests that the reorganization energy of the galvinol system is comparable to or higher than the reorganization energy of Ru(NH 3 ) 5 (pyridine) complex (0.8 eV). Deviations from the predicted pH dependence of the apparent standard constant are seen at pH less than 9. The deviations suggest that the assumption of stepwise electron and proton transfer should be questioned.