cssi/SciSciGPT-SciSciNet huggingface dataset:
Stable diffractive beam rider.

A passively stable laser-driven lightsail is described, which makes use of a spatially variant “bi-grating” sail with a mass (payload) attached to a boom (patent pending). A two-dimensional analytical model of the system, a linear stability analysis, and numerical solutions of the equations of motion are reported. The acceleration of the light sail along the beam path is found to depend on the grating parameters. We identify stability conditions that depend on the grating design, beam parameters, and boom length. The inclusion of damping is found to enhance the dynamic range of stability.
The Generalizability of Measurements: An Application to ’Blind Refereeing’ Process

This paper introduces generalizability theory as a means of assessing and improving the dependability (reliability) of the refereeing process used in journal article publication decisions. Concepts and computational procedures are presented and the power and flexibility of generalizability analysis are illustrated. It is shown that the refereeing process may be "optimized" by trading off costs and desired levels of generalizability.
Image registration of low signal-to-noise cryo-STEM data.

Abstract Combining multiple fast image acquisitions to mitigate scan noise and drift artifacts has proven essential for picometer precision, quantitative analysis of atomic resolution scanning transmission electron microscopy (STEM) data. For very low signal-to-noise ratio (SNR) image stacks – frequently required for undistorted imaging at liquid nitrogen temperatures – image registration is particularly delicate, and standard approaches may either fail, or produce subtly specious reconstructed lattice images. We present an approach which effectively registers and averages image stacks which are challenging due to their low-SNR and propensity for unit cell misalignments. Registering all possible image pairs in a multi-image stack leads to significant information surplus. In combination with a simple physical picture of stage drift, this enables identification of incorrect image registrations, and determination of the optimal image shifts from the complete set of relative shifts. We demonstrate the effectiveness of our approach on experimental, cryogenic STEM datasets, highlighting subtle artifacts endemic to low-SNR lattice images and how they can be avoided. High-SNR average images with information transfer out to 0.72 A are achieved at 300 kV and with the sample cooled to near liquid nitrogen temperature.
StretchfMRI: a novel technique to quantify the contribution of the reticular formation to long-latency responses via fMRI

Increased reticulospinal (RS) function has been observed to cause both positive and negative outcomes in the recovery of motor function after corticospinal lesions such as stroke. Current knowledge of RS function is limited by the lack of accurate, noninvasive methods for measuring RS function. Recent studies suggest that the RS tract may be involved in processing and generating Long Latency Responses (LLRs). As such, LLRs, elicited by applying precisely controlled perturbations, can thus act as a reliable stimulus to measure brainstem function using fMRI with high signal-to-noise ratio.In this paper, we present StretchfMRI, a novel technique that enables simultaneous recording of neural and muscular activity during motor responses conditioned by robotic perturbations, which allows direct investigation of the neural correlates of LLRs.Via preliminary validation experiments, we demonstrate that our technique can reliably elicit and identify LLRs in two wrist muscles–Flexor Carpi Radialis and Extensor Carpi Ulnaris. Moreover, via a single-subject pilot experiment, we show that the occurrence of an LLR in a flexor and extensor muscles modulates neural activity in distinct regions of the brainstem. The observed somatotopic organization is in agreement with the double reciprocal model of RS function observed in animal models, in which the right medullary and left pontine reticular formation are responsible for control of the motor activity in flexors and extensors, respectively.
Impact of Prescribing on New Persistent Opioid Use After Cardiothoracic Surgery

Background New persistent opioid use occurs in 3% to 14% of patients after elective surgery, but is poorly described after cardiothoracic surgery. We examined the association of prescription size with new persistent opioid use after cardiothoracic surgery. Methods Opioid-naive Medicare patients undergoing cardiothoracic surgery between 2009 and 2015 were identified. Patients who filled an opioid prescription between 30 days before surgery and 14 days after discharge and with continuous Medicare enrollment 12 months before and 6 months after surgery were selected (n = 24,549). New persistent use was defined as continued prescription fills 91 to 180 days after surgery. Prescription size was reported in oral morphine equivalents. Multivariable regression was performed for risk adjustment, and new persistent use rate was estimated. Results Patient age was 71 ± 8 years, 9222 (38%) were female, and 20,898 (85%) were white. Overall new persistent use was 12.8% (3153 of 24,549), and declined yearly from 17% in 2009 to 7.1% in 2015 (P Conclusions Size and timing of perioperative opioid prescriptions were the strongest predictors of new persistent opioid use after cardiothoracic surgery. Modifiable risk factors such as prescription size should be targeted to reduce new persistent use.
Moderate Expected Utility

The moderate utility model represents the probability of choosing an option in a pairwise comparison as an increasing function of utility difference divided by a dissimilarity metric. We provide a single, directly testable property that characterizes the model: choices are moderately transitive. We show that the model allows the analyst to accommodate well-known failures of strong transitivity, while retaining significantly more empirical bite than weak transitivity, achieving a useful compromise. Extending the analysis to the domain of risky choice, we introduce and characterize the moderate expected utility model, and we show how the analyst can measure utility and dissimilarity from observed choice behavior.
An analysis of the differences in the acute hospitalization charges following minimally invasive versus open posterior lumbar interbody fusion.

Object Minimally invasive spine (MIS) procedures are increasingly being recognized as equivalent to open procedures with regard to clinical and radiographic outcomes. These techniques are also believed to result in less pain and disability in the immediate postoperative period. There are, however, little data to assess whether these procedures produce their intended result and even fewer objective data to demonstrate that they are cost effective when compared with open surgery. Methods The authors performed a retrospective analysis of hospital charges for 1- and 2-level MIS and open posterior interbody fusion for lumbar spondylotic disease, disc degeneration, and spondylolisthesis treated at a single academic medical center. Patients presenting with bilateral neurological symptoms were treated with open surgery, and those with unilateral symptoms were treated with MIS. Overall hospital charges and surgical episode–related charges, length of stay (LOS), and discharge status were obtained from the hospital ...
Astrocytosis without globules in infant cerebral white matter. An epidemiologic study.

Abstract The epidemiologic features of the morphologic entity of hypertrophic astrocytes unaccompanied by amphophilic globules in infant cerebral white matter (HA · GL ) have been studied in a selected autopsy population of 191 infants. During the 3 years of this study the pattern of changes in the annual frequency of HA · GL in the base population most closely resembled the patterns of congenital heart disease (CHD) and cardiac catheterization. When the 33 infants with HA · GL and the 80 infants without any white matter abnormality were grouped by postnatal or total (gestational plus postnatal) age, CHD was the risk factor most closely associated with HA · GL . It is speculated that infants with CHD may be at heightened risk of HA · GL because of oxygen toxicity, prolonged hypoxia, unrecognized hypoglycemia, undernutrition, heightened risk of bacterial infection, or persistent viral infection.
Socioeconomic status and survival in older patients with melanoma.

White older men have had a sustained increase in melanoma incidence and mortality in the last 2 decades in the United States. From 1969 through 1999, it has been reported that mortality rates from melanoma increased 157% in men aged 65 and older, more than three times greater than the increase for women of the same age.1 Similarly, the incidence of melanoma increased nearly five times for older men; the incidence also increased for older women, but the increase was less than in older men. Another study2 found that the rate of thick melanomas (≥4 mm) has increased significantly in men aged 60 and older but not in men of other ages or in women. Socioeconomic status (SES) influences cancer survival. Two English studies reported that patients from affluent areas had better survival rates than patients from deprived areas for lung, breast, colorectal, bladder, prostate, uterine, and cervical cancer.3,4 Disparities in cancer survival have been also reported in the United States and Canada between socioeconomic and ethnic groups.5,6 Population-based, cohort, and hospital-based registry studies have showed lower survival from melanoma in low-SES populations.7 In those studies, SES was measured at individual (occupation) or aggregate levels (median household income, education, socioeconomic deprivation, or poverty percentage). SES may interact with other sociodemographic factors and affect living conditions and availability of health care, and by affecting health status or by determining stage at diagnosis, may affect survival from melanoma.4,7 The Surveillance Epidemiology and End Results (SEER) tumor registry, which has been linked to Medicare claims data at the National Cancer Institute, was used in this study.8 Few studies on melanoma have been done using the SEER-Medicare linked database and none on the association between SES and melanoma.9 The objective of this study was to examine the relationship between SES and survival in patients with melanoma in the older Medicare population. The hypothesis is that low SES is associated with poorer survival in patients with melanoma.
Early mammalian embryo development depends on cumulus removal technique

Cumulus removal (CR) at the zygote stage is necessary for most mammalian in vitro production (IVP). Present techniques use high fluidic stresses (vortexing) or mechanical stress with enzymatic treatment (pipetting) to remove cumulus. Herein a recently developed microfluidic device for cumulus removal from zygotes is compared with traditional vortexing. Microfluidic CR (µFCR) increased development on day 2 (20 ± 4% to 35 ± 6%, p < 0.01) and blastocyst formation at day 8 (33 ± 1% to 57 ± 5%, p < 0.01) when compared to vortex CR. Vortexing effects on embryo development were studied; 15, 30 and 120 s vortex doses. Development at day 2 was inversely proportional to duration of vortexing. An in situ transcription assay was used to assess biochemical activity of zygotes after cumulus removal. There was a spike of RNA transcription of vortexed zygotes at 2 h post CR not seen in the microfluidic treatment. These results suggest the potential for microfluidic methods to enhance production efficiencies while providing insight into basic developmental mechanisms.
Microsatellite variation in solitary and social tuco-tucos: molecular properties and population dynamics

Variation at 15 microsatellite loci was characterized for a population of the solitary Patagonian tuco-tuco (Ctenomys haigi) and a population of group-living colonial tuco-tuco (C. sociabilis), both of which were located in the Limay River Valley of south western Argentina. All loci examined were characterized by uninterrupted di- or trinucleotide repeats in both species; seven of these loci had been isolated from C. haigi and eight had been isolated from C. sociabilis. Across all loci, there was a significant tendency for both number of alleles and heterozygosity to be greater in C. haigi than in C. sociabilis. Cloning and sequencing of multiple PCR products per locus per population revealed no significant biases in allele length, suggesting that this difference in variability was not due to ascertainment bias or to population-wide differences in rates of microsatellite evolution. Instead, differences in microsatellite variation between C. haigi and C. sociabilis were more consistent with current demographic and suspected historical differences between these populations. In particular, interpopulation differences in the distribution of microsatellite allele sizes and allele frequencies suggested that C. sociabilis has been more subject to historical reductions in population size (e.g. population bottlenecks) than has C. haigi. These findings indicate that analyses of microsatellite structure can yield important insights into the population-level phenomena that contribute to diversity at these markers, including differences in population history that continue to influence levels of genetic variability.
On the Study of Politics

Despite its progress, political science is held to be out of touch with much of contemporary politics. The author lays the blame on the concept of the state, which pervades the thinking of political scientists to the extent that they cannot adequately come to terms with the widespread political situations in which anarchy, instability, discontinuity, and disorder prevail. Political science should instead "focus primarily on the political process in the dynamics of human existence."
Performance Analysis of Plug Nozzles for Turbojet and Rocket Exhausts

An attractive feature of the plug-type nozzle for turbojets and rocket jets is that it can automatically adjust its effective exit area with operating pressure ratio and achieve a high level of efficiency over a wide range of operating pressure ratio without variation of mechanical shape. The design and off-design performance analysis of such nozzles is described.Copyright © 1959 by ASME
Two-center approximation in the quantum theory of solids

A study is presented of the two-center approximation to the multicentered integrals which appear in the Hartree-Fock theory of solids when a localized set of basis functions is employed. A model potential is introduced to simulate the complicated self-consistent field of real crystals. This permits a simple separation of multicentered contributions to energy integrals and at the same time provides a system for which accurate solutions can be obtained easily. Crystal potentials are constructed for LiF, a typical ionic insulator, and silicon, a typical covalent semiconductor. All integrals with the model potentials are accurately evaluated, and the exact energy-band structures are compared to the results obtained in the two-center approximation. Two types of errors are found, and the orbital ranges are identified for which the two-center approximation is especially bad. For both crystals it is concluded that the two-center approximation is accurate for core orbitals only, semiqualitative for the valence orbitals, and completely inappropriate for orbitals which describe conduction bands. Generalization of these results is made to other systems, and it is concluded that neglect of multicentered integrals must always be done with special care if even qualitatively meaningful results are to be obtained.
The Impact of Experiential Education on Adolescent Development

This article summarizes the findings of a national study of 27 varied programs and concludes that experience-based educational programs can have a significant positive impact on the social, psychological, and intellectual development of adolescents.
Biostratinomic processes for the development of mud-cast logs in Carboniferous and Holocene swamps

Prostrate trees are common features of fossil forest litters, and are frequently preserved as mud-casts. Specimens of Carboniferous mud-cast trees and a mud-filled incipient cast of a Holocene Taxodium have been investigated to determine the biostratinomic processes responsible for their formation. These processes are complex. Hollowing of tree trunks may take place during life or by degradation after death. Once the trunk has fallen, the hollow cavity is supported by surrounding wood and/or bark tissues and acts as a conduit for sediment-laden waters. Leaf litter may be preserved on bedding surfaces. The infilling sequence of horizontal, parallel bedded, fine-grained sediment is deposited from suspended load during multiple overbank flooding events. These results differ from experimentally produced pith casts in which the sediment grain size is of fine sand. In Holocene specimens, alluvial mud within the log may provide a substrate for infaunal invertebrates. No evidence of infaunal burrowing in Carboniferous analogues exists.
Dose effect of adrenocorticotropin on aldosterone and cortisol biosynthesis in cultured bovine adrenal glomerulosa cells: in vitro correlate of hyperreninemic hypoaldosteronism.

In some critically ill patients, aldosterone secretion is diminished despite hyperreninemia. These same patients demonstrate appropriately elevated plasma ACTH and cortisol levels. In addition, infusion of ACTH or angiotensin-II (AII) fails to elicit the normal aldosterone response, implying that the defect is at the level of the zona glomerulosa (ZG) cell. To test the hypothesis that elevated ACTH levels induce this defect, Percoll-purified bovine ZG cells were plated in serum-free defined medium and cultured for 5 days. On days 1-4, cells were exposed to various concentrations of ACTH for 1 h. On the fifth day of culture, half of the wells pretreated with ACTH were treated for 1 h with AII (10(-7) M); the other half of the wells received another dose of ACTH for 1 h. Additionally, cells were exposed to daily 1-h pulses of AII (10(-7) M) alone or in combination with ACTH (10(-8) M) for 5 days. Acutely dispersed bovine ZG cells showed dose-dependent increases in aldosterone when incubated with ACTH, potas...
Commentary on “nursing home residents’ sense of coherence and functional status

Functional status is an important measure in older adults. Functional decline has been associated with emergency room visits in elders (Wilber, Blanda, & Gerson, 2006), and elders are at a high risk of functional decline after hospitalization (Cornett, Swine, Malhomme, Gillet, & D’Hoore, 2006). Furthermore, those with functional decline consume larger resources. Therefore, identifying those elders at risk for functional decline is important. This descriptive study examined functional status over time in older adults living in nursing homes.
Fibroblast growth factor-8 protects cultured rat hippocampal neurons from oxidative insult.

Basic fibroblast growth factor (bFGF) has been reported to have neuroprotective properties following excitotoxic, metabolic, and oxidative insults. We report here that another FGF family member, FGF-8 is able to protect rat hippocampal cultures from oxidative stress. The b isoform of FGF-8 protected hippocampal cultures from hydrogen peroxide with an EC50 of approximately 25 ng/ml. In a time course study, using pre-, co-, post-treatment paradigms, we report that bFGF and FGF-8b were neuroprotective when added as a pre-treatment, co-treatment, and even at 2 h post-insult. Using neuronal enriched cultures, we demonstrate that bFGF and FGF-8b neuroprotection partially results from a direct action of the growth factors on neurons. The direct action on neurons may work in concert with normal and FGF-stimulated glial secretion products to give the full FGF protective effect. FGF-8b showed maximal protection at 50 ng/ml, whereas bFGF showed maximal protection at 10 ng/ml. Despite requiring higher concentrations to elicit protection, FGF-8b is able to attain levels of protection equivalent to that of bFGF (attenuation of 75-80% of hydrogen peroxide induced death). We also report that bFGF and FGF-8b are able to protect the human neuroblastoma cell line, SK-N-MC, from peroxide-induced LDH release by 50%. From these studies, we conclude that FGF-8b is another member of the FGF family which may show in vivo efficacy for the treatment of oxidative insults, such as stroke.
Evolution of Photostimulated Luminescence During Thermal Cycling of Electron Beam Physical Vapor Deposited Thermal Barrier Coatings

Thermal barrier coatings (TBCs) are widely used for thermal protection of hot section components in turbines for propulsion and power generation. Development of a robust non-destructive evaluation (NDE) technique for TBCs is essential for quality control, life assessment and health monitoring that will facilitate reliable application, efficient maintenance and prevention of catastrophic failure. In this study, degradation of TBCs was non-destructively evaluated by photostimulated luminsecence (PSLS) and microstructurally examined as a function of furnace thermal cycling carried out in air with 10-minute heat-up, 1-, and 10-hour dwell duration at 2050°F (1121°C), and 10-minute forced-air quench. TBCs examined in this study consisted of electron beam physical vapor deposited (EB-PVD) yttria-stabilized zirconia (YSZ) on grit-blasted (Ni,Pt)Al or as-coated (Ni,Pt)Al or shot-peened NiCoCrAlY bond coats and various superalloy substrates. Characteristics of subcritical-subsurface damage near the thermally grown oxide (TGO) were documented by cross-sectional scanning electron microscopy. Mechanisms of damage varied as a function of TBC type and thermal cycling dwell time, and included preferential grain boundary oxidation after ridge-induced micro-cracking, racheting and undulation of TGO/bond coat interface, internal oxidation of bond coats, and formation of Ni/Co-rich oxides. These microstructural observations are correlated to the evolution in compressive residual stress in the TGO scale determined by photostimulated luminescence shift, including stress-relief associated with subcritical cracking in the TGO scale, and stress-relaxation associated with racheting of the TGO/bond coat interface. Correlations between the microstructural development and the photostimulated luminescence from the TGO scale are discussed as a function of TBC type and thermal cycling dwell time.Copyright © 2005 by ASME
Mobilizing the Base and Embarrassing the Opposition: Defense of Marriage Referenda and Cross-Cutting Electoral Cleavages

Using the recent spate of so-called Defense of Marriage (DOMA) referenda as a point of analysis, the author argues that direct democracy presents the potential for intensifying the nature of interparty competition at the state level. Given a particular configuration of circumstances—namely where a salient electoral issue cross-cuts already existing party cleavages—ballot referenda can become tools by which political parties “poach” members of an opposing coalition. Using data at the county level, the author finds evidence that DOMA ballot referenda do not simply mobilize conservative Protestant voters; they also (potentially) reorient the partisan loyalties of two core Democratic constituencies: African Americans and Hispanics. However, as the electoral system is dynamic, the effectiveness of referenda as mechanisms of partisan competition changes with succeeding election cycles and may even lead to unintended effects. Notably, late-cycle DOMA elections (those occurring in 2005 and 2006) provide evidence ...
The therapeutic alliance in the cognitive behavioral treatment of pediatric obsessive–compulsive disorder ☆

Abstract Although cognitive-behavioral therapy (CBT) for pediatric obsessive–compulsive disorder (OCD) is considered a first-line treatment, not all youth have a positive treatment response, suggesting need for investigating factors that may enhance or reduce treatment effects. Few studies have investigated predictors of treatment response in pediatric OCD, and there is an absence of studies examining the influence of treatment process variables (e.g., therapeutic alliance [TA]) on treatment outcome. Using a multiple-informant and multiple-time point design, the current study examined the role of the TA in family-based CBT for pediatric OCD. Analyses examined (1) the predictive value of the TA on OCD symptom reduction and (2) whether changes in the TA over time predict treatment response. Findings indicated that (1) stronger child-rated, parent-rated, and therapist-rated TAs were predictive of better treatment outcome and (2) larger and more positive early alliance shifts (as rated by changes in child-rated TA between sessions 1 and 5) were predictive of better treatment outcome. Implications for the treatment of youth with OCD within family-based CBT are discussed.
Comfort and experience with computing: are they the same for women and men?

What produces comfort with computers and how is comfort related to computer achievement for men and women? This study looks at the effects of comfort and prior spreadsheet knowledge on the ability to design spreadsheets by management science students. Results showed that comfort with computing is significantly correlated with test performance for women; for men, mathematics ability and relevance to their future career are more important. The study suggests that the quality of women's initial computing instruction is very important in affecting what they will accomplish in the future.
IgM-IgG1, 2, 3 relationship during pregnancy.

IN mice, paternal tissue grafts generally survive longer in the mother with each succeeding pregnancy1. Similar findings have been reported for rats, rabbits and humans2. Paternal tumours also survive longer in pregnant mice3. However, mating across strain does include cellular immunity directed against paternal antigens, measured by graft versus host activity4 and in vitro killing of hybrid foetal cells3 by maternal lymphocytes. Thus the survival of experimental allografts1,3 and of the natural foetal “allograft” in the face of maternal cellular immunity may depend on immunological enhancement, that is, the protection of foreign grafts by specific antibody which blocks cellular immune rejection3,5.
Numerical study of iso-Q sample geometric effects on charring ablative materials

Abstract The geometric effects of iso-Q sample – a geometry that is widely used in arc-jet experiments – were numerically studied on charring ablative materials under arc-jet conditions. The objective was to investigate how the sample diameter, thickness, and sample holder affect the pyrolysis gas transport, thermal, and material response within the material. A series of three-dimensional (3D) simulations was performed on different iso-Q samples. Identical conditions were applied on the same low-density charring ablative material, but with different sample diameters and thicknesses. The results indicate that the sample diameter influences both side-wall heating behavior and the amount of gas blowing through the front surface; the sample thickness significantly affects the side-wall blowing pattern. In addition, two types of impermeable sample holders were studied. Sample holders which sheath the outside of the sample were found to result in effects similar to shortening the depth of the sample. Moreover, for samples with high diameter-to-depth ratio, the sample holder was found to increase the blowing rate at the stagnation point. These results can be used as general guidelines for choosing model geometries in future arc-jet experiments. The importance of 3D modeling and the limit of the one-dimensional (1D) assumption made in most material response codes, are also addressed.
MITRAL VALVE REPAIR vs REPLACEMENT: Current Recommendations and Long-Term Results

Techniques now exist to correct abnormalities of all components of the mitral valvular apparatus except extensive loss of pliable leaflet area. Thus, paradoxically, myxomatous valves with redundant leaflets represent the ideal candidates for mitral valve repair. Repair for mitral insufficiency can be performed for some rheumatic valves, but patient selection is critical. Loss of leaflet area, leaflet thickening, and extensive calcification of the leaflets or commissures are contraindications to repair. The abnormalities of the subvalvular apparatus are less important because a complete set of new chordae can be reconstructed using PTFE suture material. Some cases of endocarditis are ideal for repair using localized debridement and pericardial patch repair with or without PTFE chordal replacement. True ischemic mitral regurgitation of the Carpentier type I category is still something of a surgical enigma. Because it is a restrictive leaflet motion problem, annuloplasty alone is not always effective, and the outcome of any given repair attempt is less predictable. Repairs in patients with small annuli and multiple leaflet defects requiring complex series of maneuvers have a low probability of success. Furthermore, such patients with small left ventricular cavities are more prone to experience SAM. Several factors contributing to which therapy is chosen for mitral valve disease are summarized in Table 1. Patient selection, accurate evaluation of the cause or causes of mitral regurgitation, and well-executed application of the appropriate techniques for repair are all critical factors in the early and late success of mitral valve repair.
Evaluation of myocardial ischemia using a rest metabolism/stress perfusion protocol with fluorine-18 deoxyglucose/technetium-99m MIBI and dual-isotope simultaneous-acquisition single-photon emission computed tomography

Objectives. This study sought to develop a dual-isotope single-acquisition single-photon emission computed tomographic (SPECT) protocol using a multihead SPECT camera equipped with an ultra-high energy collimator to evaluate rest metabolism/stress perfusion simultaneously with fluorine-18 (F-18) deoxyglucose/technetium-99m (Tc-99m) 2-hexakis-2-methoxy-2-methylpropyl isonitrile (MIBI). Background. The most accurate and logistic method of identifying injured but viable myocardium remains a diagnostic challenge. Methods. Sixty-five patients were given 25 to 50 g of glucose and, after ∼60 min, an injection of 370 MBq (10 mCi) of F-18 fluorodeoxyglucose. After a 35-min distribution phase, patients underwent exercise or pharmacologic stress followed by administration of 925 MBq (25 mCi) of Tc-99m MIBI. Five patients underwent F-18 fluorodeoxyglucose positron emission tomography before dualisotope SPECT. Results. With a window of 20% for both photopeaks and a technetium-99m/fluorine-18 concentration of 3.2: 1, the “spillover” from fluorine-18 into the technetium-99m window is 70% was used as the criterion for a diagnosis of coronary artery disease, dual-isotope SPECT had a sensitivity of 100%, specificity of 88%, positive predictive value of 93%, negative predictive value of 100% and an accuracy of 96%. Conclusions. Dual-isotope SPECT may provide an alternative, accurate, cost-effective method to nitrogen-13 ammonia/F-18 fluorodeoxyglucose positron emission tomography or thallium-201 reinjection for identifying injured or dysfunctional but viable myocardium.
Identifying students’ mental models of sound propagation: the role of conceptual blending in understanding conceptual change

We investigated introductory physics students’ mental models of sound propagation. We used a phenomenographic method to analyze the data in the study. In addition to the scientifically accepted Wave model, students used the “Entity” model to describe the propagation of sound. In this latter model sound is a self-standing entity, different from the medium through which it propagates. All other observed alternative models contain elements of both Entity and Wave models, but at the same time are distinct from each of the constituent models. We called these models “hybrid” or “blend” models. We discuss how students use these models in various contexts before and after instruction and how our findings contribute to the understanding of conceptual change. Implications of our findings for teaching are summarized.
The application of dustiness tests to the prediction of worker dust exposure.

Laboratory bench tests, known as dustiness tests, have been used to evaluate and compare the potential of various powders to cause occupational dust exposure. Dustiness tests are used to develop products with reduced dust emissions. The correlation between dustiness test results and dust exposures was evaluated at two bag dumping and bag filling operations. At one bag dumping and one bag filling operation, there was evidence of a relationship between dustiness test results and dust exposures. In one case, regression analysis showed that dust exposures could be predicted to within nearly one order of magnitude. The variability in this prediction was caused by the inherent variability in the occupational dust exposures. In the other case, there was evidence of a correlation after the data had been adjusted for the effect of varying drop height. At the remaining two operations, no correlation between dust exposures and dustiness test results were observed. These results indicate that the relevance of dustine...
Reconfigurable Threshold Logic Gates Using Memristive Devices

We present our design exploration of reconfigurable Threshold Logic Gates (TLG) implemented using silver–chalcogenide memristive devices combined with CMOS circuits. Results from simulations and physical circuits are shown. A variety of linearly separable logic functions including AND, OR, NAND, NOR have been realized in discrete hardware using a single-layer TLG. The functionality can be changed between these operations by reprogramming the resistance of the memristive devices.
Characterization of Ni/TiO2 catalysts by TEM, X-ray diffraction, and chemisorption techniques

Nickel crystallite sizes calculated from H2, CO, and O2 chemisorption are compared to those determined from X-ray diffraction (XRD) and transmission electron microscopy (TEM). Good agreement is obtained among all techniques for typical NiSiO2 and NiAl2O3 catalysts, whereas sizes calculated from H2 and CO chemisorption are far too large for NiTiO2 catalysts. In contrast, oxygen chemisorption provides values in excellent agreement with those from XRD and TEM, and indicates that monolayer coverages of CO and H2 are much lower on TiO2-supported nickel. This agreement also implies that oxygen monolayer coverage on TiO2-supported nickel does not exceed unity regardless of crystallite size, whereas coverages of two or higher are observed on SiO2- and Al2O3-supported nickel, in agreement with previous studies. Isobars for CO and H2 adsorption on NiTiO2 clearly show that activated adsorption is not responsible for the low CO and H2 uptakes at 300 K. Low-contrast nickel crystallites on titania are observed in the TEM micrographs, indicating that nickel may exist with a raft-like morphology on this support. These results provide evidence that strong metal-support interaction behavior exists in the NiTiO2 system.
The effects of testosterone or insulin treatment on contractile responses of the rat vas deferens following castration or streptozotocin-induced diabetes mellitus.

Abstract 1. Castration and streptozotocin-induced diabetes produce significant decreases in serum testosterone levels accompanied by decreased vas deferens weights, a decreased responsiveness to nerve stimulation, and altered contractile responses to carbachol and phenylephrine. 2. Treatment of castrated rats with testosterone for 8 weeks prevented the decreased vas deferens weights and contractile changes associated with castration. 3. Treatment of diabetic rats with testosterone for 8 weeks prevented the decreased vas deferens weights and the supersensitivity to contractile agonists associated with diabetes. Testosterone treatment only partially prevented the decreased response to nerve stimulation. 4. Treatment of diabetic rats with testosterone plus insulin for 8 weeks prevented the decreased vas deferens weights and decreased the sensitivity to carbachol and phenylephrine compared to controls. Testosterone plus insulin treatment prevented the decreased response to nerve stimulation. 5. There were no differences in the IC50 values for nitrendipine among any of the groups studied, suggesting that the contractile changes observed in vasa deferentia following castration or diabetes are not the result of changes in calcium movements. 6. The results suggest that decreased testosterone levels are at least partially responsible for the changes in contractility of the vas deferens of streptozotocin-diabetic rats.
Comparative studies on the effects of various microsomal enzyme inducers on the N-demethylation of dimethylnitrosamine

Abstract The effects of various compounds on the N -demethylation of dimethylnitrosamine (DMN) were investigated and grouped into three different categories according to their effects on both DMN-demethylase I and II (using 4 and 200 mM DMN concentrations respectively). 3-Methylchol-anthrene (3-MC), β-naphthoflavone (β-NF), Aroclor 1254, benzo[a]pyrene (BP), and phenobarbital (PB) pretreatments decreased the activity of demethylase I, but they increased or had no effect on the activity of the second enzyme. Chlorpromazine pretreatment did not alter the activity of demethylase I whereas the activity of II was enhanced significantly. Feeding tryptophan and indole to rats, on the other hand, increased the activities of both demethylases as well as the cytochrome P-450 content.
Systemic infections of neuro-ophthalmic significance

Systemic infectious disease may present with or include neuro-ophthalmic findings. Many of these signs and symptoms are related to topographical location of the infectious process,but some entities have distinctive and characteristic features that allow specific diagnosis. This article updates and reviews the neuro-ophthalmic features of infectious disease.
Rapid, broadband two-photon-excited fluorescence spectroscopy and its application to red-emitting secondary reference compounds

We present a methodology for rapidly acquiring broadband two-photon absorption (2PA) spectra by means of a compact two-channel femtosecond fluorescence excitation apparatus. This technique is insensitive to differences in excitation and collection geometries as well as detection efficiencies between the sample and reference, in addition to variations in average power, pulse duration and spatial beam profile, as it utilizes sequential measurement of the sample and reference in each of the two cell positions. Our approach eliminates the need to determine the fluorescence quantum yields of the sample and reference, as it allows measurement of emission from samples at a common specified wavelength. These attributes allow for acquisition of 2PA spectra with an estimated accuracy of ± 15% (limited almost exclusively by the uncertainty in the 2PA cross section for the reference standards) over an excitation range of 550-1600 nanometers with a typical time per spectrum of ~30-60 minutes. We have applied this technique to determine the 2PA spectra of six commercially available organic dyes over a wide range of excitation wavelengths (670-1600 nm), which can be used as secondary reference standards emitting in the red and near-infrared spectral region (600-1000 nm). We have also characterized some of these compounds using the femtosecond-pulsed Z-scan method and found very good agreement with the fluorescence-based measurements.
Wilson loops in large N field theories

We propose a method to calculate the expectation values of an operator similar to the Wilson loop in the large $N$ limit of field theories. We consider $N\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}4$ $(3+1)$-dimensional supersymmetric Yang-Mills theory. The prescription involves calculating the area of a fundamental string world sheet in certain supergravity backgrounds. We also consider the case of coincident $M$-theory five-branes where one is led to calculating the area of $M$-theory two-branes. We briefly discuss the computation for $(2+1)$-dimensional supersymmetric Yang-Mills theory with 16 supercharges which is nonconformal. In all of these cases, we calculate the energy of a quark-antiquark pair.
Lysis of Oocytes by Bovine Sperm and Seminal Plasma

Abstract This study examined the lytic activity of bovine seminal plasma on zona-free oocytes commonly used to assess bovine capacitanon. Exposure of hamster oocytes (intact or zona-free) to undiluted seminal plasma resulted in lysis within 5min. With intact oocytes, 1:5 to 1:20 seminal plasma resulted in swelling of the oocytes. With zona-free oocytes, seminal plasma (1:0 to 1:1000) resulted in lysis within 1min to 3h depending on dilution. Heating seminal plasma to inactivate complement did not reduce lytic activity, but boiling destroyed it. Lytic activity was present in seminal plasma from vasectomized bulls and in seminal vesicle fluid. After elution of seminal plasma through Sephadex G-200, lytic activity was only associated with the fraction containing proteins of 200,000 to 45,000 dal. Lytic activity remained with washed capacitated bull sperm only when 10 7 sperm/ml or more were coincubated with zona-free oocytes at 37°C for 3h. In conclusion, both bovine seminal plasma and capacitated sperm were lytic in the zona-free hamster oocyte assay. The results may explain why so few sperm are normally found at the site of fertilization.
Sex identification of turkey embryos using a multiplex polymerase chain reaction

Abstract A considerable portion of the W chromosome in Gallinaceous birds consists of tandem repetitive DNA. In the turkey, a 0.4-kb PstI element is repeated about 10,000 times in the female diploid genome but is undetectable as such a unit in males. In this study a multiplex polymerase chain reaction was developed to identify the sex of turkeys based upon the PstI repeat. The technique utilized two pairs of primers, the first pair was designed to amplify a region of the PstI repetitive element, resulting in the production of a 177-bp fragment in females. The other pair was designed to amplify a region of the adenosine triphosphate (ATP) synthase gene, present in both males and females. The simultaneous use of all four primers in the same reaction resulted in the coamplification of a 177-bp and a 250-bp fragment in females and a 250-bp fragment in males. This technique was used to verify the sex of 45 adults of known sex and to identify the sex of 74 embryos from Day 5 to hatch. This procedure is rapid and permits the sexing of many embryos in a short time. The ability to sex early embryos can facilitate studies on avian sex determination.
Octanol−Water Partition Coefficients of Cyclic C-7 Hydrocarbons and Selected Derivatives

Partition coefficients between 1-octanol and water, Kow, of 16 C-7 cyclic hydrocarbons were measured using the classic shake-flask method or the more recent slow-stir method. For eight compounds, b...
Use of functional transformations in the solution of systems of nonlinear equations having singular or near singular jacobians

A functional transformation method has been developed for use with the Newton's method for solving single algebraic equations [f(x) = 0] and systems of algebraic equations (f(x) = 0] having either maxima, minima, turning points, or singular (or near singular) Jacobians. The functional transformation method is used to trace the path of a function through a maximum or minimum. If in the course of searching for the x that makes f(x) = 0 an xk is found for which f'(xk) = 0 or for which /f(xk)/ > /f(xk−1)/, a new function F(x) having the same solution as f(x) but a different slope is defined such that /F(xk)/ < /F(xk−1/. After having passed through the maximum or minimum, the trial proceduce returns to the original function f(x). For the numerical examples presented herein, the performance of the functional transformation method was found to be superior to that of several other well known numerical methods.
Tandem Diels-Alder/fragmentation approach to the synthesis of eleutherobin.

A synthesis of 28, the carbon framework of the eleutherobin aglycone, is reported in a 15-step sequence from readily available starting materials. The tandem Diels−Alder reaction of 6 and 7 to produce 18, in which three new rings and six new stereocenters are formed, is a key step in the reaction sequence.
Modeling and control challenges in power electronics

The paper reviews some of the typical features and problems associated with modeling and control of power electronic circuits, and highlights various questions in power electronics that may be usefully examined from the viewpoint of control theory.
Warning signal and other improvements for automatic elemental analyzers

Abstract Circuits are shown to signal the completion of a cycle by automatic elemental analyzers. By modifying the circuit of Coleman Carbon-Hydrogen Analyzer the bleed rate is reduced from 100 to 10 ml per minute. A lighting arrangement for the nitrometer compartment of Coleman Nitrogen Analyzer is shown.
TOUGHENING OF ISOTACTIC POLYPROPYLENE WITH CACO3 PARTICLES

Abstract The mechanisms of deformation and fracture of isotactic polypropylene filled with CaCO3 particles were studied. Three types of particles with average diameters of 0.07, 0.7, and 3.5 μm were used at filler volume fraction from 0.05 to 0.30. The experiments included slow tensile tests, notched Izod impact tests with varying notch depths, and fracture resistance tests using double-cantilever-beam sample configurations. In slow tension, addition of fillers increased the modulus and decreased the yield stress independently of filler type. The strain at break increased with initial incorporation of fillers but decreased at higher loadings. The 0.7 μm diameter particles improved Izod impact energy up to four times that of the unfilled matrix. The other particles had either adverse or no effect on the impact toughness. The toughening mechanisms at work were plastic deformation of interparticle ligaments following particle–matrix debonding with additional contribution coming from crack deflection toughening. The failure of the 0.07 and 3.5 μm diameter particles to toughen the matrix was attributed to poor dispersion.
A distributed multi-storage I/O system for data intensive scientific computing

More and more parallel applications are running in a distributed environment to take advantage of easily available and inexpensive commodity resources. For data intensive applications, employing multiple distributed storage resources has many advantages. In this paper, we present a Multi-Storage I/O System (MS-I/O) that cannot only effectively manage various distributed storage resources in the system, but also provide novel high performance storage access schemes. MS-I/O employs many state-of-the-art I/O optimizations such as collective I/O, asynchronous I/O etc. and a number of new techniques such as data location, data replication, subtile, superfile and data access history. In addition, many MS-I/O optimization schemes can work simultaneously within a single data access session, greatly improving the performance.Although I/O optimization techniques can help improve performance, it also complicates I/ O system. In addition, most optimization techniques have their limitations. Therefore, selecting accurate optimization policies requires expert knowledge which is not suitable for end users who may have little knowledge of I/O techniques. So the task of I/O optimization decision should be left to the I/O system itself, that is, automatic from user's point of view. We present a User Access Pattern data structure which is associated with each dataset that can help MS-I/O easily make accurate I/O optimization decisions.