cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of heat treatment on U–Mo fuel foils with a zirconium diffusion barrier

Abstract A monolith fuel design based on U–Mo alloy has been selected as the fuel type for conversion of the United States’ high performance research reactors (HPRRs) from highly enriched uranium (HEU) to low-enriched uranium (LEU). In this fuel design, a thin layer of zirconium is used to eliminate the direct interaction between the U–Mo fuel meat and the aluminum-alloy cladding during irradiation. The co-rolling process used to bond the Zr barrier layer to the U–Mo foil during fabrication alters the microstructure of both the U–10Mo fuel meat and the U–Mo/Zr interface. This work studied the effects of post-rolling annealing treatment on the microstructure of the co-rolled U–Mo fuel meat and the U–Mo/Zr interaction layer. Microscopic characterization shows that the grain size of U–Mo fuel meat increases with the annealing temperature, as expected. The grain sizes were ∼9, ∼13, and ∼20 μm for annealing temperature of 650, 750, and 850 °C, respectively. No abnormal grain growth was observed. The U–Mo/Zr interaction-layer thickness increased with the annealing temperature with an Arrhenius constant for growth of 184 kJ/mole, consistent with a previous diffusion-couple study. The interaction layer thickness was 3.2 ± 0.5 μm, 11.1 ± 2.1 μm, 27.1 ± 0.9 μm for annealing temperature of 650, 750, to 850 °C, respectively. The homogeneity of Mo improves with post rolling annealing temperature and with U–Mo coupon homogenization. The phases in the Zr/U–Mo interaction layer produced by co-rolling, however, differ from those reported in the previous diffusion couple studies.
Comparison of optical coherence tomography assessments in the comparison of age-related macular degeneration treatments trials.

Objective To determine agreement between spectral-domain (SD) and time-domain (TD) optical coherence tomography (OCT) image assessments by certified readers in eyes treated for neovascular age-related macular degeneration (AMD). Design Cross-sectional study within the Comparison of AMD Treatments Trials (CATT). Participants During year 2 of CATT, 1213 pairs of SD OCT and TD OCT scans were compared from a subset of 384 eyes. Methods Masked readers independently graded OCT scans for presence of intraretinal fluid (IRF), subretinal fluid (SRF), and sub-retinal pigment epithelium (RPE) fluid and performed manual measurements of retinal, SRF, and subretinal tissue complex thicknesses at the foveal center. Main Outcome Measures Presence of fluid was evaluated with percent agreement, κ coefficients with 95% confidence intervals (CIs), and McNemar tests. Thickness measurements were evaluated with mean difference (Δ) ±95% limits of agreement and intraclass correlation coefficients (ICCs) with 95% CIs. Results Between SD OCT and TD OCT, agreement on presence of any fluid was 82% (κ = 0.46; 95% CI, 0.40–0.52), with 5% more SD OCT scans demonstrating fluid ( P P P Conclusions Agreement on fluid presence and manual thickness measurements between paired scans from each OCT modality was moderate, providing a reasonable basis to compare CATT results with future SD OCT-based trials. Fluid was detected 5% more frequently with SD OCT, which may increase frequency of fluid-based treatment. Lower-resolution and artifactual interpretation of dark areas as cystoid edema may explain the greater frequency of IRF detected with TD OCT.
Temperature control of silicon-germanium alloy epitaxial growth on silicon substrates by infrared transmission

We report the application of the technique of infrared transmission to measure the temperature of silicon wafers during the growth of silicon‐germanium alloy heteroepitaxial layers in a rapid thermal processing system. The silicon‐germanium alloy layers have negligible absorption at 1.3 and 1.55 μm over wide ranges of thickness, composition, and strain condition. The substantial improvement of the uniformity of layers grown using the technique to measure the temperature for feedback control of the lamp power has also been demonstrated.
Proteomic profiling of differentiating osteoblasts

The major event that triggers osteogenesis is the transition of mesenchymal stem cells into bone-forming, differentiating osteoblast cells. Osteoblast differentiation is the primary event of bone formation, exemplified by the synthesis, deposition and mineralization of extracellular matrix. Osteoblast differentiation is controlled tightly by sequential activation of diverse transcription factors that regulate the expression of specific genes. The spatial and temporal regulation of the differentiation process is not completely understood at the cellular or molecular level. Recent advances in mass spectrometry-based proteomics have allowed for the systematic qualitative and quantitative profiling of differentiating osteoblasts, enabling a better understanding of the multiple factors and signaling events that control the differentiation process at a molecular level. This review focuses on recent developments in the proteomic analysis of differentiating osteoblasts, including advances, challenges and future p...
The simulation of thymidine kinase enzyme kinetics in cultured cells using the computer language Cellsim.

Abstract Thymidine kinase is an enzyme that occurs in cells actively synthesizing DNA. In studies of synchronized cell populations, it has been shown that the enzyme activity disappears during the G1 phase of the cell cycle and reappears during the S and G2 phases. Its reappearance is consistent with the synthesis of the mRNA for this enzyme during the S and G2 phases and its immediate translation into active enzyme by the protein synthesis machinery within the cell. The disappearance of the enzyme is consistent with the cessation of mRNA synthesis by mitotic cells. We have now tested this concept by computer simulation of a growing cell population in which a specific mRNA is generated while cells are in the S and G2 phases of the cell cycle. The computer simulation was done using the simulation language Cellsim designed for modeling populations of cells. The Cellsim program which we developed allowed each cell to make about 1 mRNA molecule per min during the S and G2 phases. Every 3 min each mRNA molecule generated a protein enzyme molecule. The mRNA had a half-life of about 9 min, and the enzyme had a half-life of about 150 min. When these molecular parameters were coupled to the cell cycle parameters for Chinese hamster fibroblasts, the resulting curve of enzyme production with time closely matched the observed kinetics of enzyme activity seen in synchronized cells. The only part of the curve that did not fit was the rapid drop in enzyme activity which was seen as the population of mitotic cells was permitted to enter G1. This drop in activity was not seen in mitotic cells blocked with Colcemid where mRNA synthesis must be lacking. Earlier studies have shown that the Gl cells do not contain any inhibitor of enzyme activity. It therefore appears that the enzyme molecule is more unstable during the G1 phase than in any of the other phases of the cell cycle.
Electromagnetic radiation from a laser produced plasma expanding into a uniform magnetic field

A laser produced plasma expanding in a uniform magnetic field emits far infrared radiation. The time-dependent radiation history is calculated assuming spherical symmetry and compared with experiment. General features of the radiation history agree well with experimental observation. However, a detailed comparison is difficult because of the oversimplified theoretical model employed.
A twin study of sex differences in social support.

Background. Social support may reduce the risk of psychiatric illness. Though perceived as an environmental measure, genetic factors may influence levels of social support. A relationship between social roles and personality with social support suggests possible sex effects on the sources of individual differences in social support. Method. We used the responses of MZ and DZ same and opposite sex twins to 16 questions regarding their social life. Six factors - friend support, relative support, friend problem, relative problem, confidants and social integration were used for structural equation modelling. Factor derived scales were analysed for genetic, shared and unique environmental influences. Quantitative and qualitative gender differences were analysed using the software package Mx. Results. Except for relative support and confidants, no qualitative sex differences were seen. Genetic and individual specific environmental influences accounted for the variance for friend support, friend problems, relative problems and social integration and no quantitative gender differences were seen. For relative support genetic factors were detected in females but not males, while for confidants, the shared environment was important in females but not males. Conclusions. Except for relative support in males, genetic factors influence variation in all dimensions of social support. Shared environmental factors influence relative support and relative problems in both sexes. Sex differences were detected for confidants and relative support.
Stem injuries of red spruce trees of the Adirondack Mountains, New York, USA

Numerous studies have shown that red spruce (Picea rubens Sarg.) trees growing in high elevation areas of the northeastern United States have experienced a growth decline. The most obvious symptom is apical dieback, the death of first-year, over-wintering terminal buds and stems (stems with needles). Although, these symptoms and the anatomical characteristics of these symptoms have been documented, there is no recent, extensive, and quantitative documentation of the numbers of stems that show these symptoms. The purpose of this research was to determine the numbers and percentages of first-year stems that show these symptoms for stems produced in 2002, 2003, and 2004. This research project was designed to determine the degree of missing and dead stems that result from apical dieback for over-wintering stems on two branches per direction, eight directions per tree, four trees per elevation, and four elevations per mountain for each of four mountains in the Adirondack Mountains of New York. For this study, 944 stems of 2002 growth, 2151 stems of 2003 growth, and 5832 stems of 2004 growth were analyzed. For 2003 and 2004 stem samples, 206 (10%) and 1851 (32%) stems were missing/dead. Of the three new stems (two lateral stems and one central stem) produced on each established stem, central stems had higher survival rates than lateral stems. There were no statistically significant effects of direction of stems around trees or among the four elevations sampled per mountain. Since higher elevations had more stem deaths several decades ago, we conclude that the lack of an elevational effect or an directional effect on trees may have resulted from relatively high levels (32% missing/dead stems for 2004) of stem death that are currently present for red spruce trees in the Adirondack Mountains.
Influence of phosphocitrate, a potent inhibitor of hydroxyapatite crystal growth, on mineralization of cartilage and bone.

Summary An in vivo bone induction system was used to study the effect of phosphocitrate, a potent inhibitor of calcium phosphate crystallization, on the initial stages of mineralization. Subcutaneous transplantation of coarse powders of demineralized rat diaphyseal bone matrix into allogenic recipients results in a well defined sequence of mineralization steps involving cartilage formation, calcification and bone formation. Phosphocitrate when administered locally or systemically had no effect on the mineralization of either cartilage or bone. Dose levels were chosen to be consistent with that of a previous study which demonstrated that ethane-1-hydroxy-1, 1-diphosphonate (EHDP), a similarly effective in vitro inhibitor of hydroxyapatite crystallization, has a strong inhibitory effect on the initial mineralization steps. Since EHDP is not metabolized in vivo , the lack of effect of phosphocitrate in this study is suggestive of possible enzymatic hydrolysis at the calcification site which may regulate the level of phosphocitrate.
Singular and Smooth Time-Dependent Orbifolds

We consider string theory in a smooth time-dependent orbifold of Minkowski space, which is known as the ‘null-brane’, and whose limit reproduces a spacetime with a null singularity — the parabolic orbifold. We show that adding particles of small enough energy to the geometry does not cause a gravitational collapse. The null-brane is a well-behaved background of string theory where it is possible to compute string scattering amplitudes using perturbation theory. We also mention another way of making the parabolic orbifold smooth — besides considering the null-brane.
The primitive eutherian dental formula

ABSTRACT Various lines of paleontological evidence support the theory, first emphasized by McKenna (1975), that eutherians primitively had at least five premolars. The most likely transformation to the four premolar number in many modern eutherians involved the loss of a premolar in the middle of the series, perhaps at the P3 locus. Transformational hypotheses invoking the retention of a last premolar and the loss of the last molar to arrive at the four premolar, three molar formula seem less plausible. More primitive dental formulae are apparent in the Cretaceous leptictid relative, Gypsonictops, Eocene sirenians, and a number of Mesozoic non-therians. The marsupial dental pattern, however, seems anomalous, and specialized in a way that contrasts strongly with the eutherian condition. Standard dental comparisons often conceal the problem of homology between corresponding teeth in different taxa. Such comparisons are strongly affected by the particular hypothesis of dental ontogeny and transformation assumed.
Does Breakfast Consumption Affect Nutritional Adequacy of the Diets of Young Adults

Abstract LEARNING OUTCOME: To describe the impact of breakfast consumption on the nutritional adequacy of the diets of young adults. Breakfast consumption patterns of 504 young adults (x age: 23yrs.; 58% female, 70% white) were examined using the 24-hour dietary recall. Consumption patterns were then related to mean daily nutrient intake. Thirty-seven percent of young adults skipped breakfast. For those who ate breakfast, 75% ate the meal at home, 10% reported having a fast-food breakfast, and 15% reported other sources. The mean energy intake from breakfast was 485 kcal; with males consuming more energy(x=576 kcal) than females (x=413 kcal) (p
On the calibration of sensor arrays for pattern recognition using the minimal number of experiments

Abstract We investigate optimal experiment selection to train a classifier on gas sensor arrays to get the maximal possible performance in a limited number of experiments. In gas sensing, while collecting data for a particular sensor array, one has to choose what gas and concentration level is going to be presented in the next experiment. It is an active decision by the operator selecting the experiments and training the classifiers. Can the algorithm be trained sooner rather than later? Can we minimize the costs of collecting the data in terms of the man-hour of the operator and the expenses of the experiment itself? Active control sampling provides a way to deal with the challenge of minimizing the calibration costs and is applicable to any situation where experimental selection is parameterized by an external control variable. Our results indicate that active sampling strategies can only improve a random selection of experiments over a wide range of concentration of gasses. However, random or uninformed selection is fairly close. Additionally, our active sampling methodology reveals that, when there is no prior knowledge about the range of concentrations to which the sensor will be exposed during real operation, sensor must be calibrated over the entire working range, not just high concentrations. In fact, our results show that it is especially important to include low concentrations in the calibration since the lack of these values would dramatically decrease the performance of the system.
Does Similarity Breed Connection? - An Investigation in Blogcatalog and Last.fm Communities

Similarity breeds connections, the principle of homophily, has been well studied in existing sociology literature. Several studies have observed this phenomenon by conducting surveys on human subjects. These studies have concluded that new ties are formed between similar individuals. This phenomenon has been used to explain several socio-psychological concepts such as segregation, community development, social mobility, etc. However, due to the nature of these studies and limitations because of involvement of human subjects, conclusions from these studies are not easily extensible in online social media. Social media, which is becoming the infinite space for interactions, has exceeded all the expectations in terms of growth and user participation, for reasons beyond human mind. New ties are formed in social media similarly as they would emerge in real-world. However, given the differences between real-world and online social media, do the same factors that govern the construction of new ties in real-world also govern the construction of new ties in social media? In this article, we study this extremely significant question. We propose a systematic approach by studying two online social media sites, BlogCatalog and Last.fm at varying granularity of interactions and report our findings along with some interesting observations.
Rat hypothalamic GRF elicits its biologic action in GH3 cells by interaction with VIP-preferring receptor site(S)

Summary GH 3 cells can be used effectively to study the in vitro mechanism of action of GRF. In these cells, there is a time and concentration-dependent release of cAMP into the medium. Rat hypothalamic GRF, (rGRF) is 7 to 10 fold more active than human hypothalamic GRF (hGRF). VIP, a peptide which is structurally homologous to GRF, stimulates cAMP efflux in GH 3 cells, with a higher affinity than hGRF or rGRF. We propose that in contradistinction to the normal rat pituitary, the stimulation of cAMP release by GRF in GH 3 cells occurs via activation of VIP-preferring receptors and that GRF (rGRF in particular) behaves as a partial VIP agonist.
Increased diagnostic accuracy of laparoscopy in endometriosis using indigo carmine: A new technique

Objective To report the technique and outcome of laparoscopy in endometriosis using indigo carmine. Design Case report. Setting Tertiary care center. Patient(s) Twenty-nine-year-old nulligravid woman with a history of endometriosis and left unicornuate uterus with an absent right horn with a present right ovary and distal fallopian tube with recurrence of disease. Intervention(s) Operative laparoscopy for destruction of endometriosis and chromopertubation, given the patient's history of infertility. Main Outcome Measure(s) Identification of endometriosis. Result(s) Lesions of endometriosis were stained with indigo carmine and were easily identified. Conclusion(s) Tissue staining demonstrated lesions of endometriosis that were more easily identified; therefore, this technique could provide a special and unique approach to a more accurate diagnosis of endometriosis.
Acid rain and ozone depletion from pulsed Siberian Traps magmatism

The Siberian Traps flood basalts have been invoked as a trigger for the catastrophic end-Permian mass extinction. Widespread aberrant plant remains across the Permian-Triassic boundary provide evidence that atmospheric stress contributed to the collapse in terrestrial diversity. We used detailed estimates of magmatic degassing from the Siberian Traps to complete the first three-dimensional global climate modeling of atmospheric chemistry during eruption of a large igneous province. Our results show that both strongly acidic rain and global ozone collapse are possible transient consequences of episodic pyroclastic volcanism and heating of volatile-rich Siberian country rocks. We suggest that in conjunction with abrupt warming from greenhouse gas emissions, these repeated, rapidly applied atmospheric stresses directly linked Siberian magmatism to end-Permian ecological failure on land. Our comprehensive modeling supplies the first picture of the global distribution and severity of acid rain and ozone depletion, providing testable predictions for the geography of end-Permian environmental proxies.
The effect of intention on what concepts are acquired

Categories that have a strong family-resemblance structure should be learned more easily than categories based on a selected criterial attribute under conditions that promote non-analytic processing (that is guided by overall similarity). Two studies of artificial category learning by adults test the hypothesis that incidental conditions, more than intentional learning conditions, favor the acquisition of family-resemblance categories as opposed to categories based on criterial attributes. A third experiment confirms that this relation is mediated by the increased use of holistic processing under incidental conditions: exemplar encoding and sensitivity to overall similarity relations. A final study shows a parallel effect of developmental status. Under intentional learning conditions, 5-year olds, but not 10-year olds, have more difficulty learning criterial-attribute-based categories than categories organized by family resemblances. Thus, both characteristics of the task and characteristics of the learner affect the structural nature of the concept that is learned, and both effects underline the importance of overall similarity relations under more “primitive” conditions. These findings have implications for the understanding of natural concepts and natural category learning, where the role of overall similarity may have been underestimated.
Comparison of Hindcasts Anticipating the 2004 Florida Hurricane Season

Abstract Advances in hurricane climate science allow forecasts of seasonal landfall activity to be made. The authors begin with a review of the forecast methods available in the literature. They then reformulate the methods using a Bayesian probabilistic approach. This allows a direct comparison to be made while focusing on a single hindcast of the 2004 season over Florida. The models, including climatology, are estimated using Gibbs sampling. Diagnostic checks verify convergence and efficient mixing of the samples from each of the models. A below average sea level pressure gradient over the eastern North Atlantic Ocean during May and June in combination with an above average tropospheric-averaged wind index associated, in part, with a strengthening of the Bermuda high pressure during July resulted in an above average probability of at least one Florida hurricane. The relatively high hindcast probabilities for 2004 were in marked contrast to the most recent 50-yr empirical probabilities for Florida, but f...
Medical Device Regulation: An Introduction for the Practicing Physician

Patient care for the practicing physician increasingly relies on medical devices. The U.S. Food and Drug Administration is responsible for the safety and effectiveness of medical devices in the United States. In addition to playing a role in the clinical use of devices, physicians may also participate in their design, production, use, and safety by expressing their need for certain products, by providing practical input and feedback into product design, by participating in device-related research, and by reporting device-related adverse events. Physicians should understand the rules that govern the approved and unapproved use of medical devices as well as device premarket evaluation and approval processes and device postmarket surveillance.
Structural characteristics via SLDV for a class of morphing micro-air-vehicles

Conventional control surfaces have been used in most carbon fiber composite, membrane-wing autonomous micro air vehicles (MAV). In some cases, vehicle morphing is achieved using servo actuators to articulate vehicle kinematic joints, or to deform crucial wing / tail surfaces. However, articulated lifting surfaces and articulated wing sections are difficult to instrument and fabricate in a repeatable fashion. Assembly is complex and time consuming. The goal of this paper is to establish the feasibility of morphing wings on autonomous MAVs that are actuated via active materials. Active actuation is achieved via a type of piezoceramic composite called Macro Fiber Composite (MFC). This paper investigates the structural dynamics of morphing wings on MAVs that are actuated via active composites. This paper continues the work presented in1 by considering structural dynamic characteristics of the morphing vehicle determined through Scanning Laser Doppler Vibrometry (SLDV).
Paliperidone for irritability in adolescents and young adults with autistic disorder

Individuals with autistic disorder (autism) frequently exhibit significant irritability marked by severe tantrums, aggression, and self-injury. Despite advances in the treatment of this symptom domain in autism, there remains an ongoing need for more effective and better tolerated pharmacotherapies. The aim of this study is to determine the effectiveness and tolerability of paliperidone for irritability in autism. This is a prospective, 8-week open-label study of paliperidone in 25 adolescents and young adults with autism. Primary outcome measures included the Clinical Global Impressions-Improvement (CGI-I) Scale and the Irritability subscale of the Aberrant Behavior Checklist (ABC-I). Concomitant medications (except antipsychotics) were permitted if dosages were stable for ≥2 months. Twenty-one (84 %) of 25 subjects ages 12–21 years (mean 15.3 years) responded to paliperidone, based on a CGI-I Scale score of 1 or 2 (very much or much improved) and ≥25 % improvement on the ABC-I. The mean final dosage of paliperidone was 7.1 mg/day (range 3–12 mg/day). Two subjects discontinued paliperidone prior to study completion (moderate sedation, n = 1; nonresponse, n = 1). Mild-to-moderate extrapyramidal symptoms were recorded in four subjects. A mean weight gain of 2.2 ± 2.6 kg (range −3.6 to +7.9 kg) was recorded. Mean age- and sex-normed body mass index increased from 23.6 to 24.2 (p ≤ 0.001). Mean serum prolactin increased from 5.3 to 41.4 ng/mL (p ≤ 0.0001). Paliperidone treatment was associated with significant improvement in irritability and was generally well tolerated. Larger scale, placebo-controlled studies are needed to elucidate the efficacy and tolerability of paliperidone in this population.
The Carboxyl Terminus of Zona Occludens-3 Binds and Recruits a Mammalian Homologue of Discs Lost to Tight Junctions

Abstract Mammalian homologues of theDrosophila polarity proteins Stardust, Discs Lost, and Crumbs have been identified as Pals1,Pals1-associated tightjunction protein (PATJ), and human Crumbs homologue 1 (CRB1), respectively. We have previously demonstrated that PATJ, Pals1, and CRB1 can form a tripartite tight junction complex in epithelial cells and that PATJ recruits Pals1 to tight junctions. Here, we observed that the Pals1/PATJ interaction was not crucial for the ultimate targeting of PATJ itself to tight junctions. This prompted us to examine if any of the 10 post-synaptic density-95/Discs Large/zona occludens-1 (PDZ) domains of PATJ could bind to the carboxyl termini of known tight junction constituents. We found that the 6thand 8th PDZ domains of PATJ can interact with the carboxyl termini of zona occludens-3 (ZO-3) and claudin 1, respectively. PATJ missing the 6th PDZ domain was found to mislocalize away from cell contacts. Surprisingly, deleting the 8th PDZ domain had little effect on PATJ localization. Finally, reciprocal co-immunoprecipitation experiments revealed that full-length ZO-3 can associate with PATJ. Hence, the PATJ/ZO-3 interaction is likely important for recruiting PATJ and its associated proteins to tight junctions.
The standard model of particle physics

Over the past three decades a compelling case has emerged for the now widely accepted standard model of elementary particles and forces. A “Standard Model” is a theoretical framework built from observation that predicts and correlates new data. The Mendeleev table of elements was an early example in chemistry; from the periodic table one could predict the properties of many hitherto unstudied elements and compounds. Nonrelativistic quantum theory is another standard model that has correlated the results of countless experiments. Like its precursors in other fields, the standard model of particle physics has been enormously successful in predicting a wide range of phenomena. And, just as ordinary quantum mechanics fails in the relativistic limit, we do not expect the standard model to be valid at arbitrarily short distances. However, its remarkable success strongly suggests that the standard model will remain an excellent approximation to nature at distance scales as small as 10–18 m.
The German Turners and the Taming of Radicalism in Chicago [1]

The German Turner movement, a nationalistic gymnastic enterprise, migrated to the United States in the aftermath of the failed revolution of 1848. It quickly took hold in American cities with sizable German populations. Many German Turners espoused liberal philosophies, including Marxist, socialist and anarchist sympathies in their political views. They assumed leadership roles in politics, education and the labour movement; but those radical sympathies dissipated over time in the United States. This case study of Chicago, the centre of the American labour movement and a bastion of Turnerism in the United States, examines and analyzes the transition of Turner ideology and practice, from initial radicalism to incorporation within the mainstream political system, and from a focus on gymnastics to adoption of American sport forms. That transition occurred rather rapidly, largely over a period of two generations, by which time American Turners admitted that they had little in common with their European brethr...
A quasi-Monte Carlo approach to 3-D migration: Theory

A mathematical breakthrough was recently achieved in understanding the tractability of multidimensional integration using nearly optimal quasi‐Monte Carlo methods. Inspired by the new mathematical insights, we have studied the feasibility of applying quasi‐Monte Carlo methods to seismic imaging by 3-D prestack Kirchhoff migration. This earth imaging technique involves computing a large (109) number of 3-D or 4-D integrals. Our numerical studies show that nearly optimal quasi‐Monte Carlo migration can produce the same or better quality earth images using only a small fraction (one fourth or less) of the data required by a conventional Kirchhoff migration. The explanation is that an image migrated from a coarse quasi‐random array of seismic data is less likely, on average, to be aliased than an image migrated from a regular array of data. In migrating these data, the geophones act as an incoherent arrangement of loud‐speakers that broadcast the reflected wavefield back into the earth; the broadcast will pro...
Computer simulation of chiral-symmetry breaking in (2+1)-dimensional QED with N flavors.

Noncompact quantum electrodynamics in three Euclidean dimensions with N species of four-component Dirac fermions is simulated by lattice-gauge-theory techniques. On an ${8}^{3}$ lattice we find chiral-symmetry breaking in the continuum limit for N\ensuremath{\le}${N}_{c}$ but no symmetry breaking for N\ensuremath{\ge}${N}_{c}$, with ${N}_{c}$=3.5\ifmmode\pm\else\textpm\fi{}0.5. A physical picture of our results is presented.
Increased exercise SaO2 independent of ventilatory acclimatization at 4,300 m

Arterial O2 saturation (Sao2) decreases in hypoxia in the transition from rest to moderate exercise, but it is unknown whether other several weeks at high altitude SaO2 in submaximal exercise follows the same time course and pattern as that of ventilatory acclimatization in resting subjects. Ventilatory acclimatization is essentially complete after approximately 1 wk at 4,300 m, such that improvement in submaximal exercise SaO2 would then require other mechanisms. On days 2, 8, and 22 on Pikes Peak (4,300 m), 6 male subjects performed prolonged steady-state cycle exercise at 79% maximal O2 uptake (VO2 max). Resting SaO2 rose from day 1 (78.4 +/- 1.6%) to day 8 (87.5 +/- 1.4%) and then did not increase further by day 20 (86.4 +/- 0.6%). During exercise, SaO2 values (mean of 5-, 15-, and 30-min measurements) were 72.7% (day 2), 78.6% (day 8), and 82.3% (day 22), meaning that all of the increase in resting SaO2 occurred from day 1 to day 8, but exercise SaO2 increased from day 2 to day 8 (5.9%) and then increased further from day 8 to day 22 (3.7%). On day 22, the exercise SaO2 was higher than on day 8 despite an unchanged ventilation and O2 consumption. The increased exercise SaO2 was accompanied by decreased CO2 production. The mechanisms responsible for the increased exercise SaO2 require further investigation.
Paxillin-Kinase-Linker Tyrosine Phosphorylation Regulates Directional Cell Migration

Directed cell migration requires the coordination of growth factor and cell adhesion signaling and is of fundamental importance during embryonic development, wound repair, and pathological conditio...
Shape-controlled growth of micrometer-sized gold crystals by a slow reduction method.

Micrometer-sized gold crystals have been synthesized through a binary mixture of amine ligand molecules in the presence of a gold precursor under slow growth conditions (see picture). A wide range of morphologies in the form of triangles, octahedra, pentagonal decahedra, platelets, and nanowires with well-defined morphologies can be derived by varying the composition and ratio of the ligand mixture.
Postoperative and Postradiation Changes on Imaging

The normal appearance of the posttherapy neck after common surgical procedures and chemoradiation therapy is presented, with specific details for each surgical procedure. Subsequently, the authors emphasize the recognition of complications and disease recurrence with illustrated examples.
Impact of precursor size on the chain structure and mechanical properties of solvent-swollen epoxy gels

The thermal and mechanical properties of solvent-swollen epoxy gels were investigated as a function of pre-cursor size in a model end-linked network. The epoxy networks were formed by cross-linking diepoxide and diamine precursors in the presence of a low volatility solvent, dibutylphthalate (DBP). Both precursors were end functionalized and contained a poly(propylene glycol) (PPG) spacer between the epoxy and amine functionality, respectively. The lengths of both precursors were controlled by varying the molecular weight of the PPG spacer between functional groups. The glass transition temperature for the gels as a function of solvent loading was well predicted by the Fox equation. The scaling factors of shear storage modulus versus solvent loading increased with increasing diamine precursor molecular weight to values much larger (3.91) than the theoretical value of 2.3, for entanglement dominated network formation in a theta solvent. In contrast, the scaling factor increased with decreasing epoxy precursor molecular weight to values near 4.5. The large, molecular weight dependent scaling factors are attributed to loop defect formation as the result of the amine cross-linker architecture, which consists of two difunctional reactive end groups separated by a spacer. Rather than equal spacing of all four reactive sites, the amine end groups contain two reactive hydrogens that increase the local concentration of reactive species, and facilitates loop formation. We anticipate that this work will aid in the development of non-aqueous gels and provide enhanced tailoring of the gel properties over a broad range of stiffness.
FURTHER STUDIES ON THE ANDROGENICITY OF PROGESTERONE1

EVIDENCE that progesterone, the corpus luteum hormone, has androgenic properties in the rat has been presented by Lamar (1) and Greene, Burrill and Ivy (2). To date, these two contributions represent the only direct evidence for the androgenicity of this substance, although indicative evidence from various other sources is not lacking (see Greene, Burrill and Ivy). Results of other attempts to demonstrate an androgenic function for progesterone have all been negative. Albrieux and his coworkers (3) found progesterone to have no influence on the seminal vesicles of the castrated rat nor on the capon comb. Hill (4), using small amounts of progestin (extract of corpora lutea) failed to find any stimulatory effect on the accessories of the castrate male rat. Dessau (5) obtained no effect on the capon comb with progesterone. Korenchevsky and Hall (6) classified progesterone as a “purely female hormone” since, on the basis of unpublished experiments, they found it to have no effect on the male sex organs.
Emergent Literacy in Early Childhood Special Education Curriculum and Instruction

The purpose of Project I.E.P. (Intervention for Early Progress) was to discover whether young children with handicaps who were exposed to structured, print-rich environments with opportunities to e...
Timestamp consistency and trace-driven analysis for distributed parallel systems

A continuous stream of event data describing the progress of parallel program execution is realized for trace-driven analysis. Unfortunately, it is often the case that separate streams are produced independently by multiple processors in the system, and the logical order of events cannot be guaranteed due to discrepancy among local clocks. We present an integrated approach for timestamp consistency and performance analysis techniques for IBM SPn systems. The trace facility requires no source code modification, and can generate message passing and system events with minimal trace overhead. Trace-driven analysis tools are developed to extract useful information. Analysis results for NAS kernel benchmarks are reported. >
Spline-based non-parametric regression for periodic functions and its application to directional tuning of neurons

The activity of neurons in the brain often varies systematically with some quantitative feature of a stimulus or action. A well-known example is the tendency of the firing rates of neurons in the primary motor cortex to vary with the direction of a subject's arm or wrist movement. When this movement is constrained to vary in only two dimensions, the direction of movement may be characterized by an angle, and the neuronal firing rate can be written as a function of this angle. The firing rate function has traditionally been fit with a cosine, but recent evidence suggests that departures from cosine tuning occur frequently. We report here a new non-parametric regression method for fitting periodic functions and demonstrate its application to the fitting of neuronal data. The method is an extension of Bayesian adaptive regression splines (BARS) and applies both to normal and non-normal data, including Poisson data, which commonly arise in neuronal applications. We compare the new method to a periodic version of smoothing splines and some parametric alternatives and find the new method to be especially valuable when the smoothness of the periodic function varies unevenly across its domain.
S-band reflection type variable attenuator

A reflection type variable attenuator is described in this letter. The main component of the circuit is a microstrip 3 dB quadrature coupler. The coupler is used in conjunction with two varactor diodes to vary the attenuation from 2.2 dB to 17 dB over a 40% bandwidth (2.8-4.2 GHz). If married with a programmable voltage controller, the proposed design will provide a low-cost solution for applications with narrow instantaneous bandwidth.
Effect of Aspect Ratio on Flow Through Serpentine Nozzles

4, providing a Dean number of 8400 (based upon radius of curvature at the centerline of the nozzle). The experimental portion of the study was conducted by three-component laser Doppler velocimetry using a five-beam probe. A computational study was performed on the interior of the nozzle using a commercial code that employed a Reynolds stress model. With noted exceptions, good correlation was observed between the computational and experimental solutions. Secondary-flow velocities at the nozzle exit revealed evidence of a complex pattern of streamwise vortices generated by the two bends. It was found that despite the common Dean number, the difference in aspect ratio led to substantially different velocity fields. The flow was dominated by a single pair of counterrotating streamwise vortices in one case, whereas its counterpart yielded a complex pattern of multiple smaller vortices.
The Color of the Ethno/Graphic

Anthropologist Michael Taussig calls it a “polymorphous magical substance.” This is how he “prefers to think of color, something more than a spot of red or blue on a page. It affects all the senses, not just sight. It moves. It has depth and motion, and it connects such that it changes whatever it comes into contact with.” Color is elusive. The ethno/graphic then must reflect the elusive as it falls into the unavoidable trappings of social research. Color may not be route out of a long series of inescapable research traps, but this ‘polymorphous magical substance’ brings us into the montage of the everyday to reveal meanings otherwise left concealed. The purpose of this reflective essay is to demonstrate color’s necessity within the trappings of social research that often remove color, and, as a result remove the soul, substance, and meaning, from the ethnographic.
Stable isotope constraints on vein formation and fluid evolution along a recent thrust fault in the Cascadia accretionary wedge

Abstract In situ secondary ionization mass spectrometry (SIMS) analyses of oxygen isotopes in authigenic calcite veins were obtained from an active thrust fault system drilled at Ocean Drilling Program (ODP) Site 892 (44°40.4′N, 125°07.1′W) along the Cascadia subduction margin. The average δ18OPDB value of all samples is −9.9‰ and the values are the lowest of any measured in active accretionary prisms. Ranges in individual veins can be as much as 19.6‰. There is an isotopic stratigraphy related to the structural stratigraphy. Mean isotope values in the hanging wall, thrust, and footwall are −14.4‰, −9.5‰, and − 5.2‰, respectively. Several veins and crosscutting vein sequences show a general trend from lower to higher δ18O values over time. Isotopic and textural data indicate several veins formed by a crack-seal mechanism and growth into open fractures. The best explanation for the strong 18O depletions is periodic rapid flow from 2–3 km deeper in the prism. Relatively narrow isotopic ranges for most veins suggest that fluids were derived from a similar source depth for each episode of fluid pulse and calcite crystallization. Structural and mass balance considerations are consistent with a record preserved in the veins of ten to hundreds of thousands of years. The fluid pulses may relate to periodic large earthquake events such as those recognized in the paleoseismicity records from the Cascadia margin.
Zinc and human immunodeficiency virus infection

Abstract The importance of zinc in normal immune function - and of its deficiency in immune dysfunction - has led to increased interest in its role in nutrition and immunity in human immunodeficiency virus type 1 (HIV) infection. Zinc deficiency produces reversible immune dysfunction, particularly of T-lymphocyte cell-mediated immunity. In developing countries where zinc deficiency is prevalent, zinc supplementation has been shown to reduce morbidity from respiratory and diarrheal illnesses. The relationship between zinc and HIV infection has not been well delineated. Malabsorption, repeated concurrent infections and increased losses probably increase zinc requirements in HIV infection. In some studies, low plasma zinc levels occur frequently in HIV infection and have predicted disease progression and mortality, suggesting supplementation might be beneficial. However, the finding that zinc binding to specific HIV proteins is essential for HIV function and replication and the association in one observational study of zinc intake with higher rates of HIV progression have raised questions regarding the safety of zinc supplementation among HIV-infected individuals. To date, no randomized, placebo-controlled study of moderate zinc supplementation in HIV infection has been published. We believe that available evidence supports the need for and acceptability of such a trial.
From a supporter to a challenger? Japan's currency leadership in dollar-dominated East Asia

ABSTRACT The dollar dominance in East Asia has depended on its regional support. Japan's supportive policy toward the dollar, however, shifted in the late 1990s as the Japanese government began to address the region's heavy dependence on the dollar, which was regarded as one (but an important one) of the causes of the 1997 Asian Financial Crisis (AFC), by promoting the use of the yen in the region and regional monetary initiatives. Despite emerging signs of those challenges, Japan's domestic resistance and the region's power rivalry between Japan and China still makes the dollar the currency of choice in the medium term future.
The Use of Public Libraries by Native Americans

Library services to Native Americans have expanded greatly in the past several decades, but more work still needs to be done to provide for the information needs of Native Americans. Data from the U.S. Current Population Survey were used to compare library use rates of Native American households to rates of Anglo households. Results show that Native Americans still lag behind Anglos in public library use rates. Of households that report library use, Native Americans are more likely to engage in certain types of library use than are Anglos. Socioeconomic and geographic variables are indicated as factors in the lower library use rates of Native American households. Study results could be useful for groups working to improve Native American library and information services.
Prevention moderates associations between family risks and youth catecholamine levels.

Objective: The purpose of this study was to establish, using a quasi-experimental design, whether 2 family risk factors, parental psychological dysfunction and nonsupportive parenting, during preadolescence could longitudinally predict elevated sympathetic nervous system (SNS) activity 9 years later, and to determine whether participation in an efficacious family centered prevention program could moderate these associations if they emerged. Method: Rural African American preadolescents (N 476) were assigned randomly to the Strong African American Families (SAAF) program or to a control condition. When youths were 11 years of age (M 11.2 years), primary caregivers provided data on their own depressive symptoms and self-esteem, and youths provided data on their receipt of nonsupportive parenting. When the youths were 20 years of age, indicators of SNS activity, the catecholamines epinephrine and norepinephrine, were assayed from their overnight urine voids. Results: Parental psychological dysfunction and nonsupportive parenting forecast elevated catecholamine levels for youths in the control condition, but not for those in the SAAF condition. Conclusions: The demonstration that a prevention program can induce reduction of catecholamine levels is important from both theoretical and public health perspectives, because it shows that the developmental progression from family risk factors to heightened sympathetic nervous system activity is not immutable.