cssi/SciSciGPT-SciSciNet huggingface dataset:
Integrin α6 expression in human prostate carcinoma cells is associated with a migratory and invasive phenotype in vitro and in vivo

Cell adhesion and migration are important features in tumor invasion, being mediated in part by integrins (extracellular matrix receptors). Integrins are significantly decreased in human prostate cancer. An exception is alpha 6 integrin (laminin receptor) which persists during prostate tumor progression. We have selected high (DU-H) and low (DU-L) expressors of alpha 6 integrin from a human prostate tumor cell line, DU145, to assess experimentally the importance of alpha 6 integrin in tumor invasion. DU-H cells exhibited a four-fold increased expression of alpha 6 integrin on the surface compared to DU-L cells. Both cell types contained similar amounts of alpha 3 and alpha 5 integrin. The DU-H cells contained alpha 6 subunits complexed with both the beta 1 and beta 4 subunits whereas DU-L cells contained alpha 6 complexed only with beta 4. DU-H cells were three times more mobile on laminin as compared to DU-L, but adhered similarly on laminin. Adhesion and migration were inhibited with anti-alpha 6 antibody. Each subline was injected intraperitoneally into SCID mice to test its invasive potential. Results showed greater invasion of DU-H compared to DU-L cells, with increased expression of alpha 6 integrin on the tumor at the areas of invasion. These data suggest that alpha 6 integrin expression is advantageous for prostate tumor cell invasion.
Trypanosoma cruzi: Cultivation in macromolecule-free semisynthetic and synthetic media

Abstract A macromolecule-free semi-synthetic medium (F-81) was devised to culture Trypanosoma cruzi serially at room temperature. F-81 contains only one undefined substance, trypticase, which consists primarily of short-chain polypeptides. In F-81 medium T. cruzi will grow to a density of 35 to 43 × 10 6 organisms/ml, a density comparable to that obtainable in a serum-containing medium such as F-69. High concentrations of water-soluble vitamins appear to have a serum-replacing effect in the F-81 medium. A completely synthetic medium (F-84) was prepared by replacing trypticase in F-81 with Trager's amino acid mixture. T. cruzi epimastigotes could be serially cultured in F-84, with a maximum yield of 9.2 × 10 6 organisms/ml of medium after 3 to 4 weeks of incubation at 27 C.
Species-specific deletion of the viral attachment glycoprotein of avian metapneumovirus

The avian metapneumovirus (AMPV) genome encodes the fusion (F), small hydrophobic (SH), and attachment glycoprotein (G) as envelope glycoproteins. The F and G proteins mainly function to allow viral entry into host cells during the early steps of the virus life cycle. The highly variable AMPV G protein is a major determinant for distinguishing virus subtypes. Sequence analysis was used to determine if any differences between avian or mammalian cell propagated subtype C AMPV could be detected for the 1.8 kb G gene. As a result, the complete 1.8 kb G gene was found to be present when AMPV was propagated in our immortal turkey turbinate (TT-1) cell line regardless of passage number. Surprisingly, AMPV propagated for 15 or more passages in mammalian Vero cells revealed an essentially deleted G gene in the viral genome, resulting in no G gene mRNA expression. Although the Vero cell propagated AMPV genome contained a small 122 nucleotide fragment of the G gene, no other mRNA variants were detected from either mammalian or avian propagated AMPV. The G gene truncation might be caused by cellular molecular mechanisms that are species-specific. The lack of viral gene deletions suggests that avian cell propagated AMPV will provide a better alternative host for live recombinant vaccine development based on a reverse genetics system.
DPNH peroxidase: Effector activities of DPN+

Abstract At suboptimal H2O2 concentrations, DPNH inhibits the peroxidase activity of the flavoprotein, DPNH peroxidase, by converting the enzyme to an unstable intermediate that decays slowly to inactive enzyme. It is postulated that at concentrations of DPNH that are saturating for peroxidase activity, this unstable intermediate is responsible for most of the DPNH oxidation that is supported by alternate electron acceptors, such as O2 and menadione. DPN+ behaves as an activator by reversing the equilibria that lead to the unstable intermediate, thus converting the enzyme to the kinetically active complex that reduces H2O2. The data show that DPN+ binding will stimulate the peroxidase activity (by lowering the Km for H2O2) and simultaneously lead to strong inhibition of both the rate of enzyme inactivation and the rate at which DPNH is oxidized by alternate electron acceptors.
Photoreactivating enzyme from Neurospora crassa.

— Extracts of Neurospora crassa contain photoreactivating enzyme by the criteria of ability to split thymine-containing dimers and to increase the transforming ability of u.v.-irradiated Hemophilus influenzae DNA. The latter activity is heat-labile and is destroyed by trypsin. The action spectrum of such in vitro photoreactivation is a simple one (with a single maximum at 405 nm in the range 313 to 436 nm), differing from the more complicated in vitro spectra for yeast and Escherichia coli. However, the in vitro Neurospora spectrum coincides closely with the in vivo spectrum for this organism, suggesting that there is little or no “indirect” photoreactivation in Neurospora. It is concluded that the Neurospora photoreactivating enzyme is probably of a different type than those of yeast and Escherichia coli.
22A. Neurogenesis: Implications for Integrative Care of Neurological Conditions.

Focus Area: Integrative Approaches to Care Chronic neurological illnesses such as Alzheimer's Disease are the most pressing public health problems in aging societies. Biomedical and mechanistic approaches to these degenerative conditions are limited by incomplete knowledge of the initiating causes and basic mechanisms of pathogenesis. Proposed treatments such as monoclonal antibodies are built on disputed notions of the role of pathological markers such as cerebral amyloid. They are unproven and likely to be very expensive, especially if used for millions of affected or at-risk individuals. Integrative approaches emphasize multimodal, holistic approach to support the body's self-healing abilities. This approach offers a safe, effective, and cost-effective alternative to conventional biomedical treatments. There is growing evidence that neurogenesis, the birth of new neurons from neural stem cells, occurs under normal physiological conditions throughout life. The key steps in this process are under positive and negative modulation by environmental and behavioral factors. Effective management of these conditions and, indeed, prevention in populations is dependent on promoting modulatory influences that support neurogenesis and avoiding and mitigating those influences that negatively affect neurogenesis. In this session, we will hear from an interprofessional team consisting of a neurologist, an exercise physiologist, a psychotherapist and mind-body practitioner, and a traditional Chinese medicine physician who are actively developing integrative approaches to these problems.
Simulated Radiance Patterns for Finite Cubic Clouds

Abstract Calculated distributions of scattered shortwave radiance are presented for simulated cumulus clouds using a cubic shape. Comparison with similar clouds of semi-infinite horizontal extent is included. For an incident solar zenith angle of 0° the angular distribution of the radiance exiting the cloud top is similar for the cube and the semi-infinite layer, but the radiance from the cube is much smaller for optical depths between 9.8 and 73.5. At an optical depth of 73.5 the vertical radiance from the cube is only 58% of the radiance from the semi-infinite layer cloud. For an incident solar zenith angle of 60°, the angular distribution and the magnitudes of the scattered radiances are similar for the cube top and the semi-infinite layer. A comparison of the total radiance from the cube top and side in the solar plane shows a dramatic change in angular distribution compared with the semi-infinite cloud. Radiances exiting the antisolar side of the cube illustrate the strong forward scattering for shor...
The National Park Service and Civic Engagement

Edward T. Linenthal reflects on the several years he spent as a Visiting Scholar with the Civic Engagement program of the National Park Service. Linenthal conducted seminars on issues in public history for NPS staff at various sites around the country. Civic engagement has been characterized by NPS9s former Northeast Regional Director Marie Rust as "a refocusing of current efforts at partnering with communities, expanding our education agenda, telling the 9untold stories,9 and working with communities and partners to preserve sites that represent the fullness of the American experience." Linenthal discusses the particular challenge of creating a more inclusive process in the shaping of NPS9s work and the equally challenging task of creating a more diverse historic landscape.
Quantitative contamination and transfer of Escherichia coli from foods by houseflies, Musca domestica L. (Diptera: Muscidae)

The housefly, Musca domestica L. (Diptera: Muscidae), is recognized as an important factor in the dissemination of various infectious diseases such as cholera, shigellosis, and salmonellosis. They can also serve as a cross-contamination vector for other foodborne pathogens. However, the potential for bacterial transfer by houseflies has been demonstrated in a qualitative rather than quantitative manner. In this study, the numbers of bacteria a housefly can carry on its body and transfer to a clean surface after exposure to a sugar-milk aqueous solution, steak, and potato salad contaminated with a fluorescent gene Escherichia coli (8 log10 CFU/ml) were determined. In the first series of experiments to quantify bacterial numbers on the flies, about 40-60 flies were transferred into a sterile cage, exposed to the food for 30 min, the flies immobilized and the attached E. coli on each fly enumerated. Detectable E. coli (>1.7 log10 CFU/fly) were found on 43% (29/67), 53% (23/43), and 62% (32/52) of the flies in the cages with sugar/milk, steak, and potato salad, respectively. For the positive flies, the geometric mean carriage (log10 CFU/fly) was 2.93+/-1.24 for sugar-milk, 3.77+/-1.28 for steak, and 2.25+/-0.64 for the potato salad. In the second series of experiments, the transfer of bacteria by individual flies from contaminated food to the inner surface of a sterile jar per each landing was determined. E. coli transferred from the sugar-milk was 3.5+/-0.7 log10 CFU/fly-landing, 3.9+/-0.7 for steak and 2.61+/-1.16 for the potato salad. From the initial contamination levels of bacteria and the number of transferred bacteria, it can be calculated that flies contaminate clean surfaces with approximately 0.1 mg of food per landing.
Sociology of “primitive societies,” evolutionism, and Africa

Sociology of “primitive societies” has revised its earlier views about “kinship,” lineage, or lineage mode of production. It attempts now to show that lineage did not pervade African precolonial societies and that other relations, such as capitalist and class relations, were also present. This article seeks to reestablish, contrary to the revisionist view, the centrality of lineage in African precolonial societies to allow for a paradigmatic shift that repudiates evolutionism and brings precolonial societies back to the center of the African debate. Because in such a reoriented debate Africa ceases to be marginalized and on the fringes of other historical experiences, the shift allows, paradoxically, the integration of scholarship on Africa into universal social theory.
A test of leadership categorization theory: Internal structure, information processing, and leadership perceptions

Abstract This paper reports results from a series of studies designed to directly test a categorization-based model of leadership perceptions in three areas: specifying the internal structure of leadership categories, investigating the accessibility and importance of various individual behaviors in making leadership judgments, and explaining leadership perception in terms of categorization. In Study 1, data provided by 263 subjects were used to calculate three measures of category representativeness: family resemblance scores, cue validity scores, and prototypicality ratings. Results showed that leader family resemblance, cue validity, and prototypicality were all strongly correlated. In Study 2, accessibility was investigated by administering to 64 subjects a specially constructed questionnaire containing leader behaviors which varied in prototypicality and then measuring the reaction time to rate the behavior as prototypical of a leader. Results showed that there was a significant negative correlation between prototypicality and reaction time to behavioral items, suggesting that more prototypical items were more easily accessed. Study 3 manipulated prototypicality of leadership behaviors for an experimental group where leadership had been primed extensively and for a group of subjects who had been given no primes. The results showed the prototypicality manipulation strongly affected leadership ratings, behavioral expectations, and causal ascriptions to the target person, but the priming factor had no significant effects on dependent variables. Suggestions for future research and practical implications are also discussed.
Effects of Low Soil Temperature on Transpiration, Photosynthesis, Leaf Relative Water Content, and Growth Among Elevationally Diverse Plant Populations

The effects of low soil temperature on photosynthesis and water relations were examined in 17 populations of 12 vascular plant species from native elevations ranging between 10 m and 3,170 m. Root permeability to water was sufficient in the majority of populations studied so that neither transpiration nor net photosynthesis was reduced at 3 degrees C soil temperature compared to the rates at 20 degrees C soil temperature. There was no evidence of differential natural selection along altitudinal gradients for ability to maintain photosynthesis rate when roots were chilled. Leaf relative water content was typically reduced in response to soil cooling. There is a critical relative water content above which both transpiration and photosynthesis are insensitive to water content reductions. Root chilling failed to reduce relative water content below this level in most populations studied. Low soil temperatures which had no adverse effects on transpiration or photosynthesis were found to significantly retard plant growth. The observed relative water content reductions might limit growth despite their failure to affect photosynthesis. Evidence for natural selection for ability to maintain turgor upon root chilling in high elevation populations was provided by an inverse relationship between the magnitude of depression in relative water content and native elevation. Thus, growth reduction at low soil temperatures must result from impaired turgor, decreased root growth and metabolism, or impaired cytokinin synthesis and translocation rather than direct limitation of carbon assimilation.
Lysosomal hydrolases in lymphoid tissue from germ-free and neonatal rats.

Die Ergebnisse histochemischer Farbeverfahren fur β-Galaktosidase und β-Glukuronidase in lymphoiden Geweben von keimfreien Ratten sind ahnlich denjenigen von neugeborenen Tieren. Diese Daten stellen einen zusatzlichen Beweis fur die wichtige Rolle der Antigene bei der normalen neonatalen Entwicklung der lysosomalen Enzymaktivitat dar.
Factors Affecting Sample Selection in a Randomized Trial of Balance Enhancement: The FICSIT Study

OBJECTIVE: To determine demographic, functional, and health-related factors that may have influenced the selection of older adults for a randomized trial of balance enhancement. DESIGN: Comparison of participants with nonparticipants at various stages of the recruiting process. SETTING: Northeastern suburban community. PARTICIPANTS: Registered voters aged 75 and older (n = 7191). MEASUREMENTS: Demographic, health-related, functional, balance, gait, and falling characteristics. RESULTS: The overall participation rate in the randomized trial was 1.5%. Compared with nonparticipants, participants were significantly more likely to be male, married, living with others, living in a house, highly educated, healthy, and physically active. CONCLUSION: Recruiting older subjects by mail to studies of rigorous interventions can produce significant selection biases that may limit the population to which results can be generalized. J Am Geriatr Soc 44:377–382, 1996.
Multi-environmental lubrication performance and lubrication mechanism of MoS 2 /Sb 2 O 3 /C composite films

MoS2–Sb2O3–C composite films exhibit adaptive behavior, where surface chemistry changes with environment to maintain the good friction and wear characteristics. In previous work on nanocomposite coatings grown by PVD, this type of material was called a “chameleon” coating. Coatings used in this report were applied by burnishing mixed powders of MoS2, Sb2O3 and graphite. The solid lubricant MoS2 and graphite were selected to lubricate over a wide and complementary range including vacuum, dry air and humid air. Sb2O3 was used as a dopant because it acts synergistically with MoS2, improving friction and wear properties. The MoS2–Sb2O3–C composite films showed lower friction and longer wear life than either single component MoS2 or C film in humid air. Very or even super low friction and long wear-life were observed in dry nitrogen and vacuum. The excellent tribological performance was verified and repeated in cycles between humid air and dry nitrogen. The formation of tribo-films at rubbing contacts was studied to identify the lubricating chemistry and microstructure, which varied with environmental conditions. Micro-Raman spectroscopy and Auger electron spectroscopy (AES) were used to determine surface chemistry, while scanning electron microscopy and transmission electron microscopy were used for microstructural analysis. The tribological improvement and lubrication mechanism of MoS2–Sb2O3–C composite films were caused by enrichment of the active lubricant at the contact surface, alignment of the crystal orientation of the lubricant grains, and enrichment of the non lubricant materials below the surface. Sb2O3, which is not lubricious, was covered by the active lubricants (MoS2 – dry, C – humid air). Clearly, the dynamics of friction during environmental cycling cleaned some Sb2O3 particles of one lubricant and coated it with the active lubricant for the specific environment. Mechanisms of lubrication and the role of the different materials will be discussed.
FRET Detection of RyR2 Calmodulin Binding and Calcium-Dependent Modulation by RyR22460-2495 Peptide (DPc10)

We are using F-FKBP biosensors and FRET to resolve protein-protein interactions and structural changes regulating ryanodine receptor (RyR) channels. We previously showed that this approach resolves the binding of calmodulin (CaM) to its regulatory site on RyR2. Here we examine the modulation of RyR2 CaM binding by DPc10, a peptide derived from the central hot-spot region of RyR2. In 30nM Ca, DPc10 reduced F-CaM binding to RyR2 by more than half, decreasing both the apparent affinity of binding and the maximal FRET at high [F-CaM]. In contrast, in 300μM Ca DPc10 had no effect on RyR2 F-CaM binding, suggesting that DPc10 selectively inhibits apoCaM versus CaCaM binding. Accordingly, in experiments using a Ca-insensitive F-CaM (F-CaM1234), DPc10 inhibited RyR2 CaM binding regardless of [Ca], indicating that the loss of DPc10 inhibition in micromolar Ca results from Ca binding to CaM (and not from Ca binding to RyR2). To directly monitor DPc10 binding to RyR2, we attached a nonfluorescent acceptor to the peptide's N-terminus (A-DPc10). Binding of A-DPc10 to RyR2 was shown by a decrease in fluorescence of RyR2-bound F-FKBP donor (ie, FRET). Increasing Ca from 30nM to 300μM progressively reduced, but did not abolish, A-DPc10 binding to RyR2. FRET to A-DPc10 was strong when the donor was attached to FKBP at a position adjacent to the RyR2 handle region, and weaker when the donor was attached near the RyR2 clamp region. We conclude that DPc10 binds to a discrete site near the RyR2 handle to inhibit apoCaM binding to the channel. Results suggest new insights into the mechanisms by which DPc10 promotes diastolic Ca leak and myocyte hypertrophy, and new means of probing regulatory interactions between CaM and RyR2 that are crucial for cardiac function and development.
Basic fibroblast growth factor mRNA increases in specific brain regions following convulsive seizures

Basic fibroblast growth factor (bFGF) is a trophic factor synthesized in the central nervous system (CNS), where it is believed to play a role in neuronal maintenance and repair. Little is known about the regulation of this growth factor in the CNS. To determine whether the expression of the bFGF gene in the brain of adult animals changes in response to alterations of neuronal activity, we examined bFGF mRNA levels in several brain regions of rats experiencing focally-evoked convulsive seizures. Seizures were induced by microinjecting bicuculline unilaterally into an epileptogenic site within the deep prepiriform cortex, area tempestas (AT). By 5 h after initiation of brief limbic motor seizures from AT, there was a four fold increase in the levels of bFGF mRNA in the entorhinal cortex, hippocampus and olfactory bulb, but not in the caudate-putamen. The maximal expression of bFGF mRNA was reached by 10 h after seizure onset. In the same animals, the mRNA encoding nerve growth factor (NGF) was increased in entorhinal cortex and hippocampus, but not in the olfactory bulb. Our results demonstrate that neuronal activity can influence bFGF expression in an anatomically selective fashion and that acute changes in bFGF can occur in the uninjured mature brain. The increase in bFGF expression in response to excessive activation of specific neuronal circuitry may represent an adaptive response to protect against potential injury in those circuits.
Renin increases human amnion cell prostaglandin E2 biosynthesis.

Chorionic cells are known to produce several protein hormones; among them is prorenin/renin, whose function is unknown at this time. Amnion is contiguous with chorion and plays a part in the mechanism(s) of parturition through increased prostaglandin (PG) production. The purpose of the present study was to determine whether renin has any action on amnion cell PGE2 biosynthesis. Amnion cells in primary monolayer culture were incubated for 16 h with increasing concentrations of renin. Renin induced a concentration-dependent increase in amnion cell PGE2 production (e.g. in picograms of PGE2 per microgram protein/16 h; mean +/- SEM; n = 4; control, 3.01 +/- 0.15; 0.0001 U/mL renin, 9.66 +/- 2.0; 0.001 U/mL renin, 10.36 +/- 1.91; 0.01 U/mL renin, 10.3 +/- 3.36; 0.1 U/mL renin, 13.82 +/- 2.1). Significant stimulation of amnion cell PGE2 by renin is not observed until 2 h of incubation; stimulation continues a further 6 h, with little change in the following 8 h. We tested the possibility that renin's stimulatory effects were due to angiotensin-I (AI) and angiotensin-II (AII) formation by testing the effects of AI and AII directly and that of renin in the presence of saralasin, a potent antagonist of AII action. Saralasin did not inhibit the effect of renin, nor was AI or AII alone (10(-10)-10(-6) M) stimulatory. Thus, we believe that chorionic renin may have a novel role in the regulation of amnion cell PGE2 production that is independent of angiotensin formation.
Trends in Pulmonary Valve Replacement in Children and Adults With Tetralogy of Fallot

Operative correction of tetralogy of Fallot frequently results in pulmonary insufficiency and chronic volume overload, which have been linked to increased risk for adverse outcomes. No consensus recommendations for the timing of pulmonary valve replacement (PVR) exist. The aim of this study was to examine the pattern of PVR in the United States from 2004 to 2012. The Pediatric Health Information Systems database was used to perform an observational study of children and adults ≥10 years of age with diagnoses of tetralogy of Fallot who underwent PVR at 35 centers in the United States from 2004 and 2012, to assess the rate of PVR and the age at which is performed. Mixed-effects multivariate regression was used to account for patient-level covariates and center-level covariance. Additional analyses assessed for trends in cost, hospital length of stay (LOS), intensive care unit LOS, and in-hospital mortality over the study period. In total, 799 subjects at 35 centers underwent PVR over the study period. The number of PVRs performed per year increased significantly over the study period. There was significant between-center heterogeneity in age at PVR (p
HyBAR: hybrid bone-attached robot for joint arthroplasty

Background A number of small bone-attached surgical robots have been introduced to overcome some disadvantages of large stand-alone surgical robots. In orthopaedics, increasing demand on minimally invasive joint replacement surgery has also been encouraging small surgical robot developments. Among various technical aspects of such an approach, optimal miniaturization that maintains structural strength for high speed bone removal was investigated. Methods By observing advantages and disadvantages from serial and parallel robot structures, a new hybrid kinematic configuration was designed for a bone-attached robot to perform precision bone removal for cutting the femoral implant cavity during patellofemoral joint arthroplasty surgery. A series of experimental tests were conducted in order to evaluate the performance of the new robot, especially with respect to accuracy of bone preparation. Results A miniaturized and rigidly-structured robot prototype was developed for minimally invasive bone-attached robotic surgery. A new minimally invasive modular clamping system was also introduced to enhance the robotic procedure. Foam and pig bone experimental results demonstrated a successful implementation of the new robot that eliminated a number of major design problems of a previous prototype. Conclusions For small bone-attached surgical robots that utilize high speed orthopaedic tools, structural rigidity and clamping mechanism are major design issues. The new kinematic configuration using hinged prismatic joints enabled an effective miniaturization with good structural rigidity. Although minor problems still exist at the prototype stage, the new development would be a significant step towards the practical use of such a robot. Copyright © 2009 John Wiley & Sons, Ltd.
Characterizing riboswitch function: Identification of Mg2+ binding site in T box antiterminator RNA

Abstract T box bacterial genes utilize a riboswitch mechanism to regulate gene expression at the transcriptional level. Complementary base pairing of the 5′-untranslated mRNA with uncharged cognate tRNA stabilizes formation of an antiterminator element and permits complete transcription. In the absence of tRNA, a mutually exclusive RNA terminator element forms and results in transcription termination. This regulatory mechanism requires divalent metal ions at the antitermination event. The structural effects of Mg2+ binding to antiterminator model RNA were investigated to ascertain if this requirement is due to the presence of a specific metal ion binding site in the antiterminator. Spectroscopic analysis identified the presence of a hydrated, diffuse Mg2+ binding site. The results indicate that the mechanistic requirement for divalent metal ions is not due to Mg2+-induced pre-formation of a functional antiterminator receptor; rather, Mg2+ binds in a helical region of high phylogenetic sequence conservation adjacent to the tRNA binding site.
New distribution records and complementary description of Haemomaster venezuelae (Siluriformes: Trichomycteridae), a rare and poorly known fish from Northern South America

New locations of the rare Haemomaster venezuelae (Pisces: Trichomycteridae) are described. One new record is from the Rio Orinoco, Venezuela, four are from the Essequibo drainage, Guyana.
Schistosoma mansoni: Ultrastructural observations on the small intestine of the murine host

Abstract Between 6 and 29 weeks, the small intestines of mice infected with Schistosoma mansoni were studied with the electron microscope. Granulomas were confined to the serosal-muscularis regions of the small intestine. Early granulomas were characterized by having several cell types with the most conspicuous type being the eosinophil. Older granulomas were more fibrotic. These were compared with hepatic granulomas of comparable age. In the vicinity of active eggs either in granulomas or in the lamina propria, mitochrondria from epithelial cells displayed intracristal granules. Intraperitoneal injections of soluble egg antigen isolated from viable S. mansoni eggs produced identical mitochondrial abberations. Cytochrome c -cytochrome oxidase activity was visualized in the mitochondria by the diaminobenzidine method.
A novel portable bipolar near-field measurement system for millimeter-wave antennas: construction, development, and verification

As new antenna designs require higher frequencies and smaller sizes, traditional large-scale antenna measurement systems become ill-suited for such measurements. External mixing, room-sized chambers, and expensive test equipment add large costs and burdens to antenna measurement systems. A smaller and more cost-effective system is presented in this paper. Using the bipolar planar scanning technique developed at UCLA, a portable millimeter-wave antenna measurement system has recently been constructed. The system was designed to fit on the end of a standard optical table, and enjoys the spacesaving and accuracy inherent to the bipolar planar configuration. Simple construction of the chamber allows for relatively easy assembly and disassembly, and allows movement of the system from one table to another, if needed. Antennas of diameters up to 24 in can be accommodated, and scan planes of up to a diameter of 60 in can be measured. Millimeter-wave frequencies from around 30 GHz to 67 GHz can be measured, with potential extension to higher frequencies. Planar nearfield-to-far-field techniques are used to construct the antenna's far-field patterns from the measured near field. In particular, the post processing follows the OSI/EFT method for pattern reconstruction and diagnostics. The design of the scanner configuration allows the incorporation of the phase-retrieval techniques developed for the bipolar configuration. These phaseless measurements allow the use of scalar millimeter-wave test equipment, with much lower cost than comparable vector test equipment.
An Introduction to Agent-based Modeling for Undergraduates

Abstract Agent-based modeling (ABM) has become an increasingly important tool in computational science. Thus, in the final week of the 2013 fall semester, Wofford College's undergraduate Modeling and Simulation for the Sciences course (COSC/MATH 201) considered ABM using the NetLogo tool. The students explored existing ABMs and completed two tutorials that developed models on unconstrained growth and the average distance covered by a random walker. The models demonstrated some of the utility of ABM and helped illustrate the similarities and differences between agent-based modeling and previously discussed techniques— system dynamics modeling, empirical modeling, and cellular automaton simulations. Improved test scores and questionnaire results support the success of the goals for the week.
Phases of the multiple quantum well in a strong magnetic field: Possibility of irrational charge

We have constructed the phase diagram for a multiple-quantum-well system of two-dimensional electron layers in a strong perpendicular magnetic field. There are a number of different phases which appear as in-layer density and layer separation are varied. At densities corresponding to low filling factors of the lowest Landau level there are solid phases, while at higher densities a sequence of Laughlin-liquid-like states occurs at small layer separation. The excitations of the liquid states can exhibit irrational charge.
Dynamic ductile rupture under conditions of plane strain

Abstract A plate impact experiment is used to study dynamic ductile rupture at strain rates up to 10 5 s −1 in a spheroidized 1045 steel. The material has a microstructure consisting of a fine dispersion of cementite particles embedded in ferrite particles. Plane strain tensile loading is generated by impacting a deeply notched specimen with a thin elastic flyer plate. The notch, parallel to the impact plane and extending halfway through the diameter, is filled with steel shims to transmit compressive stress waves. Upon reflection from the rear surface of the specimen, the waves become tensile in nature and cause an opening mode of loading at the blunt notch tip resulting in ductile void nucleation and growth there. The nucleation of voids is observed to occur through particle-matrix debonding, particle fracture and particle-particle separation. Extensive void growth is observed at the notch tip as the impact velocity is increased. Relative notch opening displacement is found to depend on the initial notch width as well as the impact velocity. At impact velocities above 0.14 mm/μs, void nucleation due to the reflected tensile waves is also observed away from the notch along a plane parallel to the rear surface. This spallation is studied in one version of the plate impact experiment that does not involve a notch. Scanning electron microscopy of the rupture surfaces shows that spallation occurs mainly by cleavage of the ferrite grains and is assisted by void nucleation and growth on separate void sheets. Free surface velocities are monitored and analyzed at three points in front of the notch tip on the unnotched side by means of a normal velocity interferometer system. A dynamic finite element method based on a constitutive law proposed by Gurson for porous materials is used to simulate the experiments. The results have identified the mechanism for damage through the calculated and measured free surface velocity profiles.
Requiem for Philosophy

Abstract Compsing his obituary for Rome's antiquity, in his City of God Augustine proclaimed that ancient philosophy had perished, too. In casting history in the fashion, Augustine's funeral obloquy helped bury philosophy, as the ancients once had lived it from Socrates to Stoicism. In this essay, Augustine's requiem for philosophy is examined, with a view toward suggesting what philosophy would have to become in order to meet the spiritual requirements Augustine found it lacked.
Geometric single-qubit gates for an electron spin in a quantum dot

Using the analytic expression of the evolution operator for the electron spin in a quantum dot, we propose a scheme to design a universal set of single-qubit gates based solely on the geometric phase that the qubit state acquires after a cyclic evolution in the parameter space. The scheme is using ultrafast linearly chirped pulses providing adiabatic excitation of the qubit states and the geometric phase is fully controlled by the relative phase between pulses. © 2012 Wiley Periodicals, Inc.
Application of wavelet transform to uterine electromyographic signals recorded using abdominal surface electrodes.

Objective: The aim of this study was to explore the use of the wavelet transform technique to extract and display simultaneously the time, frequency and amplitude information corresponding to electromyographic (EMG) activity of the uterus during labor recorded using abdominal electrodes. Methods: Uterine EMG signals were recorded from patients in labor using three pairs of electrodes placed across the maternal abdomen. In all the patients uterine activity was also recorded either from an intrauterine pressure catheter (IUPC) or a tocodynamometer. The EMG signals were analyzed using spectral analysis and wavelet analysis. Results: Uterine EMG bursts corresponded with uterine activity measured with either the IUPC or the tocodynamometer. Using wavelet analysis a time-frequency-amplitude plot was obtained to separate out the frequency components relating to uterine EMG activity. Conclusion: This study showed that the wavelet transform could be a useful tool to study the uterine EMG activity. Continued studie...
Pulsed phytoplankton supply to the rocky subtidal zone: influence of internal waves.

Abstract Hydrographic measurements indicate that the thermocline and the phytoplankton-rich chlorophyll maximum layer are vertically displaced over a rocky pinnacle in the central Gulf of Maine by internal waves with maximum amplitudes of 27 m. Such predictable downwelling events are linked to rapid, 2- to 3-fold increases in chlorophyll a, an indicator of phytoplankton concentration, in pulses of warm water recorded 4 cm above the bottom (29-m depth). The 1.5-5.6 degrees C temperature fluctuations had an average period of 10.6 min and were generated on both ebb and flood tides. Local lee waves and the arrival of solitons propagated from Georges Bank are hypothesized to explain the timing of the internal waves. Because internal waves and chlorophyll maxima are pervasive features of stratified temperate seas, this mechanism of food coupling should be common in other rocky subtidal habitats.
Modeling Subunit Cooperativity in Opening of Tetrameric Ion Channels

Most potassium channels are tetramers of four homologous polypeptides (subunits). During channel gating, each subunit undergoes several conformational changes independent of the state of other subunits before reaching a permissive state, from which the channel can open. However, transition from the permissive states to the open state involves a concerted movement of all subunits. This cooperative transition must be included in Markov models of channel gating. Previously, it was implemented by considering all possible combinations of four subunit states in a much larger expanded model of channel states (e.g., 27,405 channel states versus 64 subunit states), which complicates modeling and is computationally intense, especially when accurate modeling requires a large number of subunit states. To overcome these complexities and retain the tetrameric molecular structure, a modeling approach was developed to incorporate the cooperative transition directly from the subunit models. In this approach, the open state is separated from the subunit models and represented by the net flux between the open state and the permissive states. Dynamic variations of the probability of state residencies computed using this direct approach and the expanded model were identical. Implementation of the direct approach is simple and its computational time is orders-of-magnitude shorter than the equivalent expanded model.
Stable isotope stratigraphy and paleoclimatology of the Paleogene Bighorn Basin (Wyoming, USA)

Abstract Climatic warming from the late Paleocene into the early Eocene had profound effects on atmospheric and marine circulation, marine thermal gradients, and benthic biota. In addition, marine carbon isotope values decreased substantially in both surface and deep waters. Because carbon is rapidly exchanged between reservoirs at the earth's surface, such as marine surface water, the atmosphere, land plants, and materials that obtain carbon from plants (e.g., soil minerals and herbivores), carbon isotope fluctuations provide time lines linking the marine and continental records. We analyzed the carbon isotope composition of paleosol carbonates and mammalian tooth enamel from stratigraphic sections in northwestern Wyoming. Carbon isotope correlation demonstrates that a short interval of extreme high-latitude warming coincided precisely with the first appearance of several important modern mammalian orders. In addition, oxygen isotope analyses of fossils and paleosol carbonates provide information about climatic conditions on land in the Paleogene. We reconstructed the oxygen isotope composition of local meteoric water using biogenic minerals. Paleocene-Eocene meteoric water was significantly 18 O-depleted, indicating substantial loss of water vapor during its transport to the region. Soil temperature was calculated as a proxy for mean annual temperature, assuming oxygen isotope equilibrium between soil carbonate and meteoric water. Calculated temperatures were plausible (≈10–25°C), but highly variable, prohibiting high-resolution analysis of local temperature variations in response to global climatic warming.
IRI: An international Rawer initiative

This paper was presented during the special session that was held at the 1993 International Reference Ionosphere (IRI) Workshop in honor of Karl Rawer's 80th birthday. It retraces the steps that led from the start of the IRI project to the present edition of the model highlighting the important role that the honoree played in guiding IRI from infancy to maturity. All summary view graphs are reproduced at the end of the article.
An affordance field for guiding movement and cognition

An embodied movement-planning field cannot account for behavior and cognition more abstract than that of reaching. Instead, we propose an affordance field, and we sketch how it could enhance the analysis of the A-not-B error, underlie cognition, and serve as a base for language. Admittedly, a dynamic systems account of an affordance field awaits significant further development.
Results of Stocking Catchable-sized Warmwater Fishes in a Lake with an Established Fish Population

Abstract Three stockings of marked, catchable-sized, warmwater fishes were made in a 30-acre lake. Creel censuses were then conducted to determine the percent recapture of these fish and their contribution to the anglers' catches. The percent returns from the spring stockings during the year in which the fish were stocked were similar for the three principal kinds of fishes, namely: crappies, 32.0 percent; bullheads, 28.3 percent; and bluegill, 26.1 percent. Further returns from these stockings during the following year averaged only 2.5 percent. As compared to returns from the spring stockings, very poor returns resulted from a fall stocking subjected to fishing the following season. The overall return in this case was only 8.6 percent. The contribution each kind of fish made to the anglers' catch of that fish varied with the density of the native population. Stocked crappies contributed 35.6 percent to the catch and bullheads 43.3 percent, while stocked bluegill contributed only 1.5 percent. There was a...
A review of high performance ultra-wideband antenna array layout design

An overview of many of the new and powerful methods for generating ultra-wideband array layouts is given, focusing mainly on the contributions of the Computational Electromagnetics and Antennas Research Lab (CEARL) at Penn State. Evolutionary strategies and optimization algorithms are used exclusively with most of these design techniques, allowing for easy creation of arrays of various sizes and properties. These ultra-wideband array design methods span multiple dimensions, ranging from simple linear arrays to planar and volumetric types. A selection of design methods will be covered here along with example arrays, their performance, and suggested applications.
A comparison of species diversity and morphological diversity across the North American latitudinal gradient

There are vastly more plants and animals in the tropics than elsewhere. In the past 100 years, many hypotheses have been investigated, but no concise answer to what drives tropical diversity has emerged. One reason is that the usual way of examining diversity, species richness, is only one possible descriptor. Other measures, such as morphological diversity, may be equally revealing, and comparisons between measures may provide still better resolution. I performed the first explicit comparison of species richness and morphological diversity of terrestrial mammal communities across latitude. Mammal com- munities differed in diversity of both body sizes and body shapes. Tropical sites were less size diverse and more shape diverse than predicted by random models. Polar sites were more size diverse and less shape diverse than predicted. The analysis indicated that different evolutionary and ecological factors determine community structure at different points along this latitudinal gradient.
Contributions of atom probe tomography to the understanding of nickel-based superalloys ☆

Abstract Atom probe tomography enables atomic level microstructural characterization to be performed on complex engineering materials such as superalloys. The technique provides information on the size, morphology and compositions of coexisting phases, the solute partitioning of the elements between the phases, and solute segregation to interfaces and grain boundaries. This information leads to a more complete understanding of nickel-based superalloys. The types of atomic level information that may be obtained with atom probe tomography are illustrated with examples of the formation of fine γ precipitates within the central region of the γ′ phase in PW 1480, the evolution of the dual γ′/γ″ nature of secondary precipitates in alloy 718, the interphase precipitation of the γ′ phase at the primary γ″–γ interface in alloy 718, and the quantification of the level and spatial extent of the boron segregation at grain boundaries in a nickel–molybdenum superalloy.
Colonial Latin America

Colonial Latin America. MARK A. BURKHOLDER and LYMAN JOHNSON. New York: Oxford University Press, 1990. x+360 pp., bibliography, index. $13.95 (paper). ISBN not available.
Regulation of cAMP by the p75 neurotrophin receptor: insight into drug design of selective phosphodiesterase inhibitors.

Subcellular compartmentalization of PDEs (phosphodiesterases) is a major mechanism for the regulation of cAMP signalling. The identification of the proteins that recruit specific PDE isoforms to subcellular compartments can shed light on the regulation of spatial and temporal cAMP gradients in living cells and provide novel therapeutic targets for inhibiting functions of PDEs. We showed recently that p75 NTR (p75 neurotrophin receptor) interacts directly with a single PDE isoform, namely PDE4A4/5, via binding to its unique C-terminal region, and targets cAMP degradation to the membrane. The purpose of this review is to present the biological significance of PDE4A compartmentalization by p75 NTR and discuss the potential of inhibiting the interaction between p75 NTR and PDE4A for the development of an isoform-specific inhihibitor for PDEs.