cssi/SciSciGPT-SciSciNet huggingface dataset:
Spin-based logic in semiconductors for reconfigurable large-scale circuits

Research in semiconductor spintronics aims to extend the scope of conventional electronics by using the spin degree of freedom of an electron in addition to its charge. Significant scientific advances in this area have been reported, such as the development of diluted ferromagnetic semiconductors, spin injection into semiconductors from ferromagnetic metals and discoveries of new physical phenomena involving electron spin. Yet no viable means of developing spintronics in semiconductors has been presented. Here we report a theoretical design that is a conceptual step forward-spin accumulation is used as the basis of a semiconductor computer circuit. Although the giant magnetoresistance effect in metals has already been commercially exploited, it does not extend to semiconductor/ferromagnet systems, because the effect is too weak for logic operations. We overcome this obstacle by using spin accumulation rather than spin flow. The basic element in our design is a logic gate that consists of a semiconductor structure with multiple magnetic contacts; this serves to perform fast and reprogrammable logic operations in a noisy, room-temperature environment. We then introduce a method to interconnect a large number of these gates to form a 'spin computer'. As the shrinking of conventional complementary metal-oxide-semiconductor (CMOS) transistors reaches its intrinsic limit, greater computational capability will mean an increase in both circuit area and power dissipation. Our spin-based approach may provide wide margins for further scaling and also greater computational capability per gate.
PARTIAL OCCLUSION OF THE PULMONARY AORTA AND INFERIOR VENA CAVA WITH THE METALLIC BAND. OBSERVATIONS ON CHANGES IN THE VESSEL WALL AND IN THE HEART

In dogs a constricting metallic band does not affect the integrity of the wall of the vena cava, whereas it leads to a rapid death of the wall of the aorta, and, as evidenced by a single instance studied, to a much slower death of the pulmonary artery. In the instance, just mentioned, constriction of the common pulmonary artery by an aluminum band for a period of 2½ years led to a right ventricular hypertrophy.
Regulatory Interactions between RNA and Polycomb Repressive Complex 2

Polycomb repressive complex 2 (PRC2) is a histone methyltransferase that is localized to thousands of mammalian genes. Though important to human disease and as a drug target, how PRC2 is recruited remains unclear. One model invokes cis-regulatory RNA. Herein, we biochemically and functionally probe PRC2’s recognition of RNA using the X-inactivation model. We observe surprisingly high discriminatory capabilities. While SUZ12 and JARID2 subunits can bind RNA, EZH2 has highest affinity and is somewhat promiscuous. EED regulates the affinity of EZH2 for RNA, lending greater specificity to PRC2-RNA interactions. Intriguingly, while RNA is crucial for targeting, RNA inhibits EZH2’s catalytic activity. JARID2 weakens PRC2’s binding to RNA and relieves catalytic inhibition. We propose that RNA guides PRC2 to its target but inhibits its enzymatic activity until PRC2 associates with JARID2 on chromatin. Our study provides a molecular view of regulatory interactions between RNA and PRC2 at the chromatin interface.
Induction of immune responses to ovarian tumor antigens by multiparity.

OBJECTIVE Because epidemiologic data indicate a reduction in ovarian cancer risk with increased parity, the occurrence of maternal immunization against ovarian tumor-associated antigens during pregnancy was investigated. METHODS Sera were obtained from nulligravid and multiparous women and from men. Cellular proteins were isolated from four ovarian tumor cell lines as well as from normal ovaries. These proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the presence of cellular proteins reactive with each individual's serum was assessed by Western immunoblot. Tumor-reactive antibodies from two multiparous women were used to prepare immunoaffinity columns for the isolation of reactive proteins from ovarian tumor cells. These immunoaffinity-purified antigens were transferred electrophoretically to nitrocellulose membranes, stained with Ponceau S, and identified by amino acid sequencing. RESULTS Western immunoblot analysis of the cellular proteins from four established ovarian tumor cell lines using sera from multiparous women as the primary antibody indicated that these samples recognized multiple bands on ovarian tumors, ranging from 30 to 150 kD. Two commonly recognized proteins were isolated and subjected to microsequencing, which identified the 56-kD band protein as elongation factor-1 alpha and the 38-kD protein as nucleophosmin/B23 protein. Both of these proteins play integral roles in cell growth. CONCLUSION These findings suggest that certain antigens expressed by the fetus immunize women during pregnancy. This immune response may protect these women from the subsequent development of cancer.
Scheduling in multichannel wireless networks with flow-level dynamics

This paper studies scheduling in multichannel wireless networks with flow-level dynamics. We consider a downlink network with a single base station, M channels (frequency bands), and multiple mobile users (flows). We also assume mobiles dynamically join the network to receive finite-size files and leave after downloading the complete files. A recent study [16] has shown that the MaxWeight algorithm fails to be throughput-optimal under this flow-level dynamics. The main contribution of this paper is the development of joint channel-assignment and workload-based scheduling algorithms for multichannel downlink networks with dynamic flow arrivals/departures. We prove that these algorithms are throughput-optimal. Our simulations further demonstrate that a hybrid channel-assignment and workload-based scheduling algorithm significantly improves the network performance (in terms of both file-transfer delay and blocking probability) compared to the existing algorithms.
Scalable Video Data Placement on Parallel Disk Arrays

We present three strategies for placement of video data on parallel disk arrays. Using a low- level disk model and video data from a scalable subband coding technique, we derive constraints with which to compare the three strategies. One strategy, constant frame grouping, is shown to be superior. Two methods for interleaving multiple videos under the constant frame grouping strategy are presented: nonperiodic and periodic. Periodic interleaving is shown to have the advantages of a lower access time and limited scan and pause functions. The constant frame grouping strategy is tested on an actual array of 8 disks and shown to have performance that is close to the theoretical prediction. The scalable nature of the compressed data is used to relieve the disk system overload for an overly high request rate.
Forecast of inflow of Colorado River into Lake Mead at Boulder Dam, 1939

The May 1, 1939, forecast of inflow to Lake Mead was as follows: Accumulated precipitation during the period October 1938–April 1939, inclusive, compared with similar accumulative records for corresponding periods of the two previous seasons, indicated that the total precipitation to May 1, 1939, was 90 per cent of the average of the previous years, and that the inflow to Lake Mead would probably be 8,000,000 acre-feet between May 1 and August 1, 1939. Based on water-content of snow, records of this character available since 1936 indicated that the water-content as of May 1, 1939, was 91 per cent of the previous three-year average, or that the probable inflow would be 7,000,000 acre-feet.
A biologically active peptide mimetic of N-acetylgalactosamine/galactose.

Glycosylated proteins and lipids are important regulatory factors whose functions can be altered by addition or removal of sugars to the glycan structure. The glycans are recognized by sugar-binding lectins that serve as receptors on the surface of many cells and facilitate initiation of an intracellular signal that changes the properties of the cells. We identified a peptide that mimics the ligand of an N-acetylgalactosamine (GalNAc)-specific lectin and asked whether the peptide would express specific biological activity. A 12-mer phage display library was screened with a GalNAc-specific lectin to identify an amino acid sequence that binds to the lectin. Phage particles that were eluted from the lectin with free GalNAc were considered to have been bound to a GalNAc-binding site. Peptides were synthesized with the selected sequence as a quadravalent structure to facilitate receptor crosslinking. Treatment of human peripheral blood mononuclear cells for 24 h with the peptide stimulated secretion of interleukin-8 (IL-8) but not of IL-1β, IL-6, IL-10, or tumor necrosis factor-α (TNF-α). The secretion of IL-21 was stimulated as strongly with the peptide as with interferon-γ. The data indicate that the quadravalent peptide has biological activity with a degree of specificity. These effects occurred at concentrations in the nanomolar range, in contrast to free sugars that generally bind to proteins in the micro- to millimolar range.
Fear and greed: The evolution of double liability in American banking, 1865–1930

Abstract This paper examines the pattern and timing of the enactment of double liability for state banks in the United States prior to the Great Depression. Under double liability, shareholders of failing banks could lose, in addition to the initial purchase price of shares, an amount equal to the par value of shares owned. The results suggest that double liability was adopted by states subject to greater economic risks, where bank failures were more likely, or where the economy and banking sector were more advanced and bank failures would be more costly (i.e., fear), and that single liability was adopted by more rapidly growing states, where the payoff to greater risk-taking was higher (i.e., greed).
Implementation and validation of advanced unintentional islanding testing using power hardware-in-the-loop (PHIL) simulation

Unprecedented investment in new renewable power (especially solar photovoltaic) capacity is occurring. As this new generation capacity is interconnected with the electric power system (EPS), it is critical that their grid interconnection systems have proper controls in place so that they react appropriately in case of an unintentional islanding event. Advanced controls and methods for unintentional islanding protection that go beyond existing standards, such as UL 1741 and IEEE Std 1547, are often required as more complex high penetration photovoltaic installations occur. This paper describes the implementation, experimental results, and validation of a power hardware-in-the-loop (PHIL)-based platform that allows for the rapid evaluation of advanced anti-islanding and other controls in complex scenarios. The PHIL-based approach presented allows for accurate, real-time simulation of complex scenarios by connecting a device under test to a software-based model of a local EPS. This approach was validated by conducting an unintentional islanding test of a photovoltaic inverter, as described in IEEE 1547.1, using both PHIL and discrete hardware-based test configurations. The comparison of the results of these two experiments demonstrates that this novel PHIL-based test platform accurately emulates traditional unintentional islanding tests. The advantage of PHIL-based testing over discrete hardware-only testing is demonstrated by completing an IEEE 1547.1 unintentional islanding test using a very precisely tuned resonant circuit that is difficult to realize with discrete hardware using PHIL.
Heating and cooling of the thermal X-ray plasma in solar flares

Characteristic times for heating and cooling of the thermal X-ray plasma in solar flares are estimated from the time profile of the thermal X-ray burst and from the temperature, emission measure and over-all length scale of the flare-heated plasma at thermal X-ray maximum. The heating is assumed to be due to magnetic field reconnection, and the cooling is assumed to be due to heat conduction and radiation.
Imaging the Localized Protein Interactions Between Pit-1 and the CCAAT/Enhancer Binding Protein α in the Living Pituitary Cell Nucleus

The homeodomain protein Pit-1 cooperates with the basic-leucine zipper protein CCAAT/enhancer binding protein alpha (C/EBPalpha) to control pituitary-specific prolactin gene transcription. We previously observed that C/EBPalpha was concentrated in regions of centromeric heterochromatin in pituitary GHFT1-5 cells and that coexpressed Pit-1 redistributed C/EBPalpha to the subnuclear sites occupied by Pit-1. Here, we used fluorescence resonance energy transfer microscopy to show that when C/EBPalpha was recruited by Pit-1, the average distance separating the fluorophores labeling the proteins was less than 7 nm. A mutation in the Pit-1 homeodomain, or truncation of the C/EBPalpha transactivation domain disrupted the redistribution of C/EBPalpha by Pit-1. Fluorescence resonance energy transfer analysis revealed that the mutant Pit-1 still associated with C/EBPalpha, and the truncated C/EBPalpha still associated with Pit-1, but these interactions were preferentially localized in regions of centromeric heterochromatin. In contrast, a truncation in C/EBPalpha that prevented DNA binding also blocked its association with Pit-1, suggesting that the binding of C/EBPalpha to DNA is a critical first step in specifying its association with Pit-1. These findings indicated that the protein domains that specify the interaction of Pit-1 and C/EBPalpha are separable from the protein domains that direct the positioning of the associated proteins within the nucleus. The intimate association of Pit-1 and C/EBPalpha at certain sites within the living cell nucleus could foster their combinatorial activities in the regulation of pituitary-specific gene expression.
Career preparation for doctoral students: The University of Kansas history department

A historian chronicles her department's efforts to reorient its graduate program to prepare students pragmatically for their careers.
The 'current state of play' in transplantation and restoration research of the CNS.

Atthe Network of European CNS Transplantation and Restoration 2005 meeting, a number of revealing studies were reported that could be divided into two broad, overlapping groups; methods to maximize the efficacy of cell transplantsin vitro and their usein vivo. A variety of different forms of stem cells ranging from embryonic stem cells to cells expressing specific genes following lentiviral vector transduction were investigated. Methods to improve the efficacy of transplants included the cotransplantation of other cell lines, exposure of the recipient to an enriched environment, and methods to promote differentiation.
Symposium Human Resource Management in Nonprofit Organizations

The nonprofit sector, with its roots in volunteerism, increasingly plays a central role in the country's cultural, economic, and social development. Recent statistics attest to the significance of ...
The ontological function of interpersonal communication: A cross‐cultural analysis of Americans and Palestinians

This article explores the ontological function of interpersonal communication (Stewart, 1977/1986), which focuses on the processes of communication that enable individuals to form, negotiate, and preserve self‐definitions. The ontological function offers a vehicle for understanding how and why all forms of human communication are unique in their expression. The study contrasts self‐definitions held by Palestinians with those held by Americans based upon the high‐to‐low context continuum (Hall, 1976) and the doing‐to‐being value orientation (Kluckhohn & Strodtbeck, 1961). The study illustrates how these culturally variant self‐definitions are mirrored in culturally mediated patterns of the ontological function.
Reframing bodies: AIDS, bearing witness, and the queer moving image, by Roger Hallas

Roger Hallas, Durham, NC, Duke University Press, 2009, 319 pp., US$ 24.95 (paperback), ISBN 978-0-8223-4601-2 In Reframing bodies, Roger Hallas proposes a compelling and exciting evaluation – or re...
Superconvergence and a posteriori error estimates for the LDG method for convection-diffusion problems in one space dimension

In this paper we investigate the superconvergence properties of the local discontinuous Galerkin (LDG) method applied to transient convection-diffusion problems in one space dimension. We show that the leading terms of the local discretization errors for the p-degree LDG solution and its spatial derivative are proportional to (p+1)-degree right and left Radau polynomials, respectively. Thus, the discretization errors for the p-degree LDG solution and its spatial derivative are O(h^p^+^2) superconvergent at the roots of (p+1)-degree right and left Radau polynomials, respectively. The superconvergence results are used to construct asymptotically correct a posteriori error estimates. These error estimates are computationally simple and are obtained by solving a local steady problem with no boundary conditions on each element. Numerical computations suggest that these a posteriori LDG error estimates for the solution and its spatial derivative at a fixed time t converge to the true errors at O(h^p^+^3) and O(h^p^+^2) rates, respectively. We also show that the global effectivity indices for the solution and its derivative in the L^2-norm converge to unity at O(h^2) and O(h) rates, respectively. Finally, we show that the LDG method combined with the a posteriori error estimation procedure yields both accurate error estimates and O(h^p^+^2) superconvergent solutions. Our proofs are valid for arbitrary regular meshes and for P^p polynomials with p>=1, and for periodic, Dirichlet, and mixed Dirichlet-Neumann boundary conditions. Several numerical simulations are performed to validate the theory.
Optimal control of switching systems

This paper considers an optimal control problem for a switching system. For solving this problem we do not make any assumptions about the number of switches nor about the mode sequence, they are determined by the solution of the problem. The switching system is embedded into a larger family of systems and the optimization problem is formulated for the latter. It is shown that the set of trajectories of the switching system is dense in the set of trajectories of the embedded system. The relationship between the two sets of trajectories (1) motivates the shift of focus from the original problem to the more general one and (2) underlies the engineering relevance of the study of the second problem. Sufficient and necessary conditions for optimality are formulated for the second optimization problem. If they exist, bang-bang-type solutions of the embedded optimal control problem are solutions of the original problem. Otherwise, suboptimal solutions are obtained via the Chattering Lemma.
Duty's classification of natural waters and chemical composition of atmospheric precipitation in USSR: A review

The present review contains Durov's method of classifying natural waters on the basis of ionic composition. The chemical composition of atmospheric precipitation in USSR is also presented.
Cementicles and fragments of cementum in the periodontal membrane.

Abstract Cementicles are spherical calcified bodies lying free in the periodontal membrane. They may also be incorporated within the cementum or the alveolar bone or even within the bone marrow spaces of the tension side of drifting or moved teeth. They originate from calcified epithelial rests, from dystrophically calcified connective tissue within the areas of indefinite fibers, from small spicules of cementum or alveolar bone traumatically displaced into the periodontal membrane and modeled by the functional movement of the tooth, from calcified Sharpey's bundles, and eventually from calcified thrombosed vessels within the periodontal membrane. Cementicles undergo deposition of either primary or secondary cementum. They may also show osteoclastic resorption. Occasionally they fracture, but the fragments may become united by callus. The fusion of free cementicles around the apical end is not considered as a true cementoma. Larger parts of cementum found in the periodontal membrane result from trauma. These fragments may become united with the root surface by a bony callus or may be coupled to the root surface by a newly formed periodontal membrane.
Methods for point source analysis in high energy neutrino telescopes

Abstract Neutrino telescopes are moving steadily toward the goal of detecting astrophysical neutrinos from the most powerful galactic and extragalactic sources. Here we describe analysis methods to search for high energy point-like neutrino sources using detectors deep in the ice or sea. We simulate an ideal cubic kilometer detector based on real world performance of existing detectors such as AMANDA, IceCube, and ANTARES. An unbinned likelihood ratio method is applied, making use of the point spread function and energy distribution of simulated neutrino signal events to separate them from the background of atmospheric neutrinos produced by cosmic ray showers. The unbinned point source analyses are shown to perform better than binned searches and, depending on the source spectral index, the use of energy information is shown to improve discovery potential by almost a factor of two.
The photodynamic occlusion of choroidal vessels using benzoporphyrin derivative

We used benzoporphyrin derivative-monoacid (BPD-MA), a new photosensitizing agent, in photodynamic therapy (PDT) to occlude choroidal vessels in the rabbit. Using BPD-MA, seven dutch-belted rabbit eyes were photodynamically treated to achieve acute choroidal vessel closure. Fundoscopy, fluorescein angiography (FA), and histology were performed 1 hour, 1 day, 3 days, 7 days, 14 days, 21 days, and 28 days after PDT. On FA, PDT-treated spots remained nonperfused until day 3 when gradual reperfusion from the periphery began to appear. By day 28 the area of PDT appeared completely reperfused. Histology of lesions showed acute damage to choroidal vascular endothelial cells and retinal pigment epithelial (RPE) cells. Over subsequent days, recovery of RPE cells and regeneration of large choroidal vascular endothelial cells occurred. In addition, retinal degeneration occurred gradually over the 28 days of follow-up. Since current argon laser therapy of retinal neovascularization causes immediate retinal damage, the ability to occlude choroidal vessels without inducing acute thermal damage holds promise for treating clinical pathologic conditions that feature abnormal neovascularization, such as age-related macular degeneration and diabetic retinopathy.
Electromagnetic beam modes driven by anisotropic electron streams.

A theory is presented which provides an explanation for recent laboratory observations of a 'new electromagnetic' mode in a non-Maxwellian high-beta plasma' and suggests a likely relevance of these modes to space plasmas. Unstable parallel-propagating waves, which can be beam modes or whistlers, depending mainly on the degree of velocity anisotropy in a weak electron beam, are found. In the beam-mode limit relevant to the experiment, this is a kinetic Weibel instability, enhanced by a parallel magnetic field. The frequency of the mode can be above or below the electron cyclotron frequency.
Modeling and efficient optimization for object-based scalability and some related problems

MPEG-4 is the first visual coding standard that allows coding of scenes as a collection of individual audio-visual objects. We present mathematical formulations for modeling object-based scalability and some functionalities that it brings with it. Our goal is to study algorithms that aid in semi-automating the authoring and subsequent selective addition/dropping of objects from a scene to provide content scalability. We start with a simplistic model for object-based scalability using the "knapsack problem"-a problem for which the optimal object set can be found using known schemes such as dynamic programming, the branch and bound method and approximation algorithms. The above formulation is then generalized to model authoring or multiplexing of scalable objects (e.g., objects encoded at various target bit-rates) using the "multiple choice knapsack problem." We relate this model to several problems that arise in video coding, the most prominent of these being the bit allocation problem. Unlike previous approaches to solve the operational bit allocation problem using Lagrangean relaxation, we discuss an algorithm that solves linear programming (LP) relaxation of this problem. We show that for this problem the duality gap for Lagrange and LP relaxations is exactly the same. The LP relaxation is solved using strong duality with dual descent-a procedure that can be completed in "linear" time. We show that there can be at most two fractional variables in the optimal primal solution and therefore this relaxation can be justified for many practical applications. This work reduces problem complexity, guarantees similar performance, is slightly more generic, and provides an alternate LP-duality based proof for earlier work by Shoham and Gersho (1988). In addition, we show how additional constraints may be added to impose inter-dependencies among objects in a presentation and discuss how object aggregation can be exploited in reducing problem complexity. The marginal analysis approach of Fox (1966) is suggested as a method of re-allocation with incremental inputs. It helps in efficiently re-optimizing the allocation when a system has user interactivity, appearing or disappearing objects, time driven events, etc. Finally, we suggest that approximation algorithms for the multiple choice knapsack problem, which can be used to quantify complexity vs. quality tradeoff at the encoder in a tunable and universal way.
Culture, power, authenticity and psychological well-being within romantic relationships: A comparison of European American and Mexican Americans

Abstract This study investigated possible cultural differences in the association of power, authentic self-expression, and well-being within romantic relationships. Participants ( N = 314) included European American students from a central Texas university and Mexican American students from a border university. Results indicated that power inequality was associated with a lack of authentic self-expression among men and women in both populations, although a three-way interaction between sex, culture, and power indicated that Mexican American men responded differently than other groups. Results also indicated that a lack of authenticity negatively impacted psychological health, especially for Mexican Americans. Findings suggest that authentic self-expression is one of the primary ways in which power inequality impacts close interpersonal relationships, and that gender and cultural variables must be examined simultaneously when considering the link between power and authenticity.
Is there a vitamin E paradox

In addition to epidemiologic studies that suggest a benefit for high intakes of alpha-tocopherol, studies of supplementation in humans have clearly shown that alpha-tocopherol decreases lipid peroxidation, platelet aggregation, and functions as a potent anti-inflammatory agent. In the five large prospective clinical trials with alpha-tocopherol therapy, four have shown a beneficial effect on cardiovascular end-points (two studies on a primary end-point and two studies on other cardiovascular end-points). Thus, the totality of evidence based on the epidemiologic data, in-vitro studies and animal models, and the clinical trials appears to support a benefit for alpha-tocopherol supplementation in patients with pre-existing cardiovascular disease. However, definitive recommendations must await ongoing clinical trials.
Controlled modulation of the phase separation and opacification temperature of purified bovine γIV-crystallin

In the bovine lens the γIV-crystallin fraction is a principal determinant of the phase separation and opacification temperature, TC (Siezen et al, Proc. Natl. Acad. Sci. USA 82, 1985, 1701). We have now measured the effect on TC of purified γIV-crystallin solutions produced by a variety of reagents which affect protein-protein, protein-water and water-water interactions.Ionic strengths less than physiological increase TC dramatically, while higher ionic strength has very little effect. Calcium ion concentrations up to 8 mM produce no change in TC. Glycerol and acrylamide both depress TC linearly with reagent concentrations; TC depression of γIV-crystallin by these compounds is quantitatively the same as for whole lens.Sulfhydryl reducing agents such as glutathione and dithiothreitol lower TC, while hydrogen peroxide increases TC. Changes in opacification temperature of γIV-crystallin produced by oxidizing and reducing agents are time-dependent and highly non-linear with reagent concentration.Our results c...
Spatial heterogeneity of factors determining ethanol production site selection in the U.S., 2000-2007.

Abstract Bivariate probit regression and spatial clustering methods analyze investment activity of ethanol plants at the county level for the contiguous 48 United States from 2000–2007. Infrastructure, product and input markets, fiscal policy of local communities, and state and federal incentives determined the location of ethanol plants. The ability to supply feedstock and the absence of previously established ethanol plants dominated the distribution of site selection. Other factors, such as access to railroads or navigable rivers, product markets, lower wages, producer credit and excise tax incentives, and methyl tertiary-butyl ether bans provided some counties comparative advantage with respect to attracting ethanol plants.
Adherence counseling practices of generalist and specialist physicians caring for people living with HIV/AIDS in North Carolina.

CONTEXT: National guidelines recommend that practitioners assess and reinforce patient adherence when prescribing antiretroviral (ART) medications, but the extent to which physicians do this routinely is unknown.
Epitaxial Growth of Vacuum-Evaporated Co on NaCl. I. Conditions Leading to Epitaxy

Conditions necessary for complete epitaxial growth ((001) [100] Co // (001) [100] NaCl) of f.c.c. Co on NaCl were investigated. Both high-evaporation rates and vacuum cleavage were found necessary, which indicates the importance of substrate cleanliness. It also appears necessary to avoid the nucleation of h.c.p. Co in order to obtain epitaxial growth of the f.c.c. phase. The development of “abnormal” h.c.p. crystals of Co in fiber texture orientation (00.1) h.c.p. // (001) Nacl is discussed. It is suggested that contaminants aid the occurrence of h.c.p. Co in preference to the f.c.c. form. Die Bedingungen wurden untersucht, die fur ein vollstandiges epitaxiales Wachstum ((001) [100] Co // (001) [100] NaCl) von kfz-Co auf NaCl notwendig sind. Es wurde gefunden, das sowohl hohe Aufdampfraten wie auch Spaltung der Kristalle im Vakuum notwendig sind, was die Bedeutung der Reinheit des Substrats zeigt. Es erscheint ebenfalls notwendig, die Keimbildung von hep-Co zu vermeiden, um expitaxiales Wachstum der kfz-Phase zu erhalten. Die Entwicklung „anomaler” hcp-Kristalle von Co in Fibertexturorientierung (0.01) hcp // (00.1) NaCl wird diskutiert. Es wird angenommen, das Verunreinigungen das Auftreten von hep-Co gegenuber der kfz-Form unterstutzen.
Visually comparing multiple partitions of data with applications to clustering

Tightly coupled visualization and analysis is a powerful approach to data exploration especially for clustering. We describe such a specific integration of analysis and visualization for the evaluation of multiple partitions of a data set. Partitions are decompositions of a dataset into a family of disjoint subsets. They may be the results of clustering, of groupings of categorical dimensions, of binned numerical dimensions, of predetermined class labeling dimensions, or of prior knowledge structured in mutually exclusive format (one data item associated with one and only one outcome). Partition or cluster stability analysis can be used to identify near-optimal structures, build ensembles, or conduct validation. We extend Parallel Sets to a new visualization tool which provides for the mutual comparison and evaluation of multiple partitions of the same dataset. We describe a novel layout algorithm for informatively rearranging the order of records and dimensions. We provide examples of its application to data stability and correlation at the record, cluster, and dimension levels within a single interactive display.
Inheritance of mercury tolerance in the aquatic oligochaete Tubifex tubifex

Resistance to contaminants is an important yet unmeasured factor in sediment toxicity tests. The rate at which mercury resistance develops and its genetic persistence in the oligochaete worm Tubifex tubifex were studied under laboratory conditions. Worms were raised for four generations under two different sediment treatments, one reference clean sediment, the other contaminated with mercury. Worms raised in mercury-contaminated sediment developed mercury tolerance that persisted even when the worms were raised for three subsequent generations in clean sediment. Mercury tolerance was determined by comparative water-only toxicity tests with mercury as the only stressor. Control worms had a mean lethal concentration (LC50) of 0.18 mg/L(-1). Worms exposed to high levels of mercury in sediment had high mercury tolerance with a mean LC50 of 1.40 mg/L(-1). When mercury-tolerant and control mercury-intolerant worms were crossed, their descendants also demonstrated mercury tolerance during lethal toxicity tests. The LC50 for worm descendants resulting from this cross was 1.39 mg/L(-1). Adaptation to mercury exposures occurred rapidly in this group of worms and appears to be due to both phenotypic and genotypic mechanisms. Development of contaminant resistance and adaptation may be common phenomena in aquatic benthic invertebrates, which should be considered during the design and interpretation of toxicity tests.
Versatility and robustness of Gaussian random fields for modelling random media

One of the authors (JAQ) has recently introduced a method of modelling random materials using excursion sets of Gaussian random fields. This method uses convex quadratic programming to find the optimal admissible field autocorrelation function, providing both theoretical and computational advantages over other techniques such as simulated annealing. In this paper, we discuss the application of this algorithm to model various aerogel systems given small-angle neutron scattering data. We also present new results concerning the robustness of this method.
The Mesoscale and Microscale Structure and Organization of Clouds and Precipitation in Midlatitude Cyclones. I: A Case Study of a Cold Front

Abstract Detailed information is deduced on the mesoscale organization of precipitation, the structures of the clouds, the air flows associated with mesoscale rainbands, and the precipitation efficiencies and the mechanisms producing precipitation in the rainbands associated with a cold front. Measurements were obtained with quantitative reflectivity and Doppler radars, two instrumented aircraft, serial rawinsondes and a network of ground stations. The regions of heaviest precipitation were organized into a complex mesoscale rainband in the warm-sector air ahead of the front, a narrow band of precipitation at the surface cold front, and four wide cold-frontal rainbands. The wide cold-frontal rainbands and the smaller mesoscale areas of precipitation within them moved with the velocities of the winds between ∼3—6 km. The narrow rainband, which was produced by strong convergence and convection in the boundary layer, moved with the speed of the cold front at the surface. A coupled updraft and downdraft was p...
Boosted Bayesian network classifiers

The use of Bayesian networks for classification problems has received a significant amount of recent attention. Although computationally efficient, the standard maximum likelihood learning method tends to be suboptimal due to the mismatch between its optimization criteria (data likelihood) and the actual goal of classification (label prediction accuracy). Recent approaches to optimizing classification performance during parameter or structure learning show promise, but lack the favorable computational properties of maximum likelihood learning. In this paper we present boosted Bayesian network classifiers, a framework to combine discriminative data-weighting with generative training of intermediate models. We show that boosted Bayesian network classifiers encompass the basic generative models in isolation, but improve their classification performance when the model structure is suboptimal. We also demonstrate that structure learning is beneficial in the construction of boosted Bayesian network classifiers. On a large suite of benchmark data-sets, this approach outperforms generative graphical models such as naive Bayes and TAN in classification accuracy. Boosted Bayesian network classifiers have comparable or better performance in comparison to other discriminatively trained graphical models including ELR and BNC. Furthermore, boosted Bayesian networks require significantly less training time than the ELR and BNC algorithms.
Nitric oxide as a potent fumigant for postharvest pest control.

ABSTRACT There is a great demand for safe and effective alternative fumigants to replace methyl bromide and other toxic fumigants for postharvest pest control. Nitric oxide, a common signal molecule in biological systems, was found to be effective and safe to control insects under ultralow oxygen conditions. Four insect species including western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae); aphid, Nasonovia ribisnigri (Mosley) (Homoptera: Aphididae); confused flour beetle, Tribolium confusimi Jacquelin du Val (Coleoptera: Tenebrionidae); and rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), at various life stages were fumigated with 0.1–2.0% nitric oxide under ultralow oxygen levels of ≤50 ppm in 1.9-liter glass jars at 2–25°C depending on insect species. Fumigations were effective against all four insect species. Efficacy of nitric oxide fumigation increased with nitric oxide concentration, treatment time, and temperature. There were also considerable vari...
On the continuum approximation of large reaction mixtures

In analyzing a reaction mixture of very many components, treating the mixture as a continuum can produce results of generality. In many practical situations (e.g., hydrodesulfurization), it is highly desirable to predict the overall behavior of the mixture at large times (high conversions) with minimum information on the mixture property. For irreversible first-order reactions in a plug-flow reactor, it was previously shown that the continuum approximation cannot be valid at arbitrarily large times. This work is an investigation of the validity of the approximation for mixtures with complex kinetics. It is found that the approximation can be conditionally or universally valid, depending on kinetics, reactor type, pore diffusion, and mixture properties. The validity conditions for a variety of situations, nontrivial as they may seem, take a power-law form. Backmixing and pore diffusion widen the range of validity. The underlying physics and some dichotomies/subtleties are discussed. The results are applied to catalytic hydroprocessing in petroleum refining. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Cellular neural networks

A novel class of information-processing systems called cellular neural networks is proposed. Like neural networks, they are large-scale nonlinear circuits which process signals in real time. Like cellular automata, they are made of a massive aggregate of regularly spaced circuit clones, called cells, which communicate with each other directly only through their nearest neighbors. Some applications in such areas as image processing are demonstrated, albeit with only a crude circuit. In particular, examples of cellular neural networks which can be designed to recognize the key features of Chinese characters are presented. Some theorems concerning the dynamic range and the steady states of cellular neural networks are proved. In view of the near-neighbor interactive property of cellular neural networks, they are much more amenable to VLSI implementation than general neural networks. >
Country of origin, encounter norms, and crowding in a frontcountry setting

Existing normative studies have focused on backcountry encounter norms reported by North Americans. This study compares encounter norms and perceptions of crowding reported by visitors from five different countries of origin—Canada, United States, Japan, Germany, and England—to a frontcountry day‐use recreation area. Data were obtained from random samples of two types of visitors—those riding in “snocoach” tour vehicles (n = 463) and those on the toe of the glacier (n = 375)—at the Columbia Icefield in Jasper National Park, Alberta. Results indicated both similarities and differences among the visitors. In terms of differences, Anglo American respondents were least likely to specify a norm, while the Germans and Japanese were most likely. Among those who reported an encounter norm, however, the average tolerance limit did not vary by country of origin. Few differences were also apparent for perceived crowding levels among the five visitor groups. Irrespective of country of origin, when contacts exceeded t...
Yersinia pestis kills Caenorhabditis elegans by a biofilm-independent process that involves novel virulence factors.

It is known that Yersinia pestis kills Caenorhabditis elegans by a biofilm-dependent mechanism that is similar to the mechanism used by the pathogen to block food intake in the flea vector. Using Y. pestis KIM5, which lacks the genes that are required for biofilm formation, we show that Y. pestis can kill C. elegans by a biofilm-independent mechanism that correlates with the accumulation of the pathogen in the intestine. We used this novel Y. pestis–C. elegans pathogenesis system to show that previously known and unknown virulence-related genes are required for full virulence in C. elegans. Six Y. pestis mutants with insertions in genes that are not related to virulence before were isolated using C. elegans. One of the six mutants carried an insertion in a novel virulence gene and showed significantly reduced virulence in a mouse model of Y. pestis pathogenesis. Our results indicate that the Y. pestis–C. elegans pathogenesis system that is described here can be used to identify and study previously uncharacterized Y. pestis gene products required for virulence in mammalian systems.
A note on block relative gain and Euclidean condition number

New relations between the block relative gain and condition number are developed that complement previously available results. It is shown that the condition number must be large if the corresponding block relative gain has a large maximum singular value, and the minimal condition number must be large if the block relative gain has a large structured singular value. These results are useful in clarifying the role of block relative gain as a measure of potential design difficulties associated with a certain class of plants. >
Articulating factors defining RMS delay spread in LV PLC networks

Communication over the power line network (PLN) referred as power line communication (PLC) has a long history of narrowband applications. With the recent developments in the field of digital communications, current interest is to exploit this medium for wideband communications for several applications such as Internet access, home networking, and in-vehicle data communication. In line with this recently emerging interest which envisions the conversion of a power transmission network into a communication network, understanding the root-mean-squared (RMS) delay spread is essential for multipath PLC channels for the establishment of reliable communication systems. In this paper, factors that play a role on the RMS delay spread value of low voltage (LV) PLC channels are articulated. Among these factors, dependency of the RMS delay spread on attenuation, loading, and physical characteristics of the communication channel in the PLNs is investigated.
Bone density and the lightweight skeletons of birds

The skeletons of birds are universally described as lightweight as a result of selection for minimizing the energy required for flight. From a functional perspective, the weight (mass) of an animal relative to its lift-generating surfaces is a key determinant of the metabolic cost of flight. The evolution of birds has been characterized by many weight-saving adaptations that are reflected in bone shape, many of which strengthen and stiffen the skeleton. Although largely unstudied in birds, the material properties of bone tissue can also contribute to bone strength and stiffness. In this study, I calculated the density of the cranium, humerus and femur in passerine birds, rodents and bats by measuring bone mass and volume using helium displacement. I found that, on average, these bones are densest in birds, followed closely by bats. As bone density increases, so do bone stiffness and strength. Both of these optimization criteria are used in the design of strong and stiff, but lightweight, manmade airframes. By analogy, increased bone density in birds and bats may reflect adaptations for maximizing bone strength and stiffness while minimizing bone mass and volume. These data suggest that both bone shape and the material properties of bone tissue have played important roles in the evolution of flight. They also reconcile the conundrum of how bird skeletons can appear to be thin and delicate, yet contribute just as much to total body mass as do the skeletons of terrestrial mammals.
Transmural Gradient of Retrograde Collateral Blood Flow in Acutely Ischemic Canine Myocardium

The contribution of retrograde coronary flow to total collateral flow was examined transmurally in anesthetized, open-chest dogs subjected to acute obstruction of the left anterior descending coronary artery. Regional coronary flow in normal and ischemic tissue was reflected by the tissue content of radioisotopes of potassium and rubidium and by radioactive microspheres. To measure total collateral flow, one isotope was administered when the retrograde cannula was clamped. The other isotope was administered when the cannula was opened to divert retrograde coronary flow away from acutely ischemic myocardium. Significant quantities of this isotope reached the ischemic region despite diversion of retrograde flow at an average rate of 3.5 ml/min. These results confirm earlier, but disputed, reports that total coronary collateral flow exceeds retrograde flow and are indicative of collateral pathways associated more closely with the microcirculation than with the larger epicardial arteries. Furthermore, the transmural distribution of myocardial blood flow in the ischemic tissue was altered nonuniformly by diversion of retrograde flow: 42K or 86Rb uptake was reduced to 25% of control in subepicardial tissue but only to 70% of control in subendocardial tissue. The transmural distribution of radioactive microspheres was similarly affected by diversion of retrograde flow. The results suggest that collateral pathways differ transmurally and may include significant luminal connections. Retrograde coronary flow is not a sensitive index of collateral flow to acutely ischemic subendocardial tissue.