Control for oriented growth of large size KCl crystals by the competition between spontaneous and induced nucleation/growth on a Langmuir-Blodgett film

Langmuir-Blodgett (LB) film of stearic acid was used as template to induce the nucleation and growth of KCl crystals when the KCl solution was cooled from 50 to 25 degrees C. When the LB film template was vertically dipped into the solution, only induced crystals with (1 1 0) orientation were formed. However, if the template was horizontally placed into solutions, both the induced nuclei at the solution/film interface and spontaneous nuclei formed in solution were simultaneously absorbed onto the LB film, and then grew further to form crystals. X-ray diffraction (XRD) patterns and optical microscopy images showed that the orientation and morphology of the crystals were controlled properly by changing the orientation and position of the LB films in the solutions.

The competition between the liquid-liquid dewetting and the liquid-solid dewetting

We investigate the dewetting behavior of the bilayer of air/PS/PMMA/silanized Si wafer and find the two competing dewetting pathways in the dewetting process. The upper layer dewets on the lower layer (dewetting pathway 1, the liquid-liquid dewetting) and the two layers rupture on the solid substrate (dewetting pathway 2, the liquid-solid dewetting). To the two competing dewetting pathways, the process of forming holes and the process of hole growth, influence their competing relation. In the process of forming holes, the time of forming holes is a main factor that influences their competing relation. During the process of hole growth, the dewetting velocity is a main factor that influences their competing relation.

Competition of lamellar orientation in thin films of a symmetric poly(styrene)-b-poly(L-lactide)diblock copolymer in melt state

We have studied the lamellar orientation in thin films of a model diblock copolymer, symmetric poly(styrene)-b-poly(L-lactide) (PS-PLLA), in the melt state on supported silicon wafer surface. In this system, while the PLLA block prefers to wet the polymer/substrate interface, the polymer/air as well as polymer/polymer interface is neutral for both blocks due to the similar surface energies of PS and PLLA in melt state. Our results demonstrate that the interplay of the interfaces during phase separation results in a series of structures before approaching the equilibrium state. Lamellar orientation of thin films with different initial film thicknesses at different annealing stages has been investigated using atomic force microscopy (AFM), transmission electronic microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It is found that in the early stage (annealing time t < 10 min), the polymer/substrate interface dominates the structure evolution, leading to a parallel lamellar structure with holes or islands formed depending on the initial film thickness. Later on, the neutral air interface becomes important and leads to a transition of lamellar orientation from parallel to perpendicular. It is interesting to see that for films with thickness h > 2L, where L is the bulk lamellar period, the lamellar orientation transition can occur independently in different parallel lamellar domains due to the neutrality of polymer/polymer interface.

Competition between band filling and steric effect in ordered double perovskites Sr2-xLaxMnMoO6

The ordered double perovskites, Sr2-xLaxMnMoO6, were prepared by sol-gel reaction. Structural, magnetic, and electrical properties were investigated for a series of ordered double perovskites Sr2-xLaxMnMoO6(0 <= x <= 1). The compounds have a monoclinic structure (space group P2(1)/n) and the cell volume expands monotonically with La doping. The T-C and the magnetic moment rise and the cusp-like transition temperature below which the magnetic frustration occurs shifts to high temperature as x increases. With La doping, electrical resistivity of Sr2-xLaxMnMoO6 decreases only at low doping levels (x <= 0.2); while at high doping levels (0.8 <= x <= 1), electrical resistivity tends to increase greatly. The results suggest that the competition between band filling effect and steric effect coexists in the whole doping range, and the formation of ferrimagnetic interactions is not simply at the expense of antiferromagnetic interactions.

On morphology and the competition between crystallization and phase separation in polypropylene-polyethylene blends

Blends of polypropylene (PP) and low density polyethylene (LDPE) have been examined for a series of compositions using differential scanning calorimetry and permanganic etching followed by transmission electron microscopy. Thermal analysis of their melting and recrystallization behaviour suggests two possibilities, either that below 15 wt % PP the blends are fully miscible and that PP only crystallizes after LDPE because of compositional changes in the remaining melt, or else that the PP is separated, but in the form of droplets too small to crystallize at normal temperatures. Microscopic examination of the morphology shows that the latter is the case, but that a fraction of the PP is nevertheless dissolved in the LDPE. (C) 1998 Kluwer Academic Publishers.

Competition between Stipa grandis and Cleistogenes squarrosa

Competitive strategy for resources between Cleistogenes squarrosa (Trin.) Keng which is a dominant species of grasslands degraded by moderate-heavy grazing, and Stipa grandis P. Smirnov, which is a dominant species of ungrazed communities, was studied using a replacement series method in a greenhouse. The knowledge would be helpful in managing grasslands and restoring the degraded C. squarrosa grassland. Although there was neither inter- nor intra-specific competition between the two species when no nutrients were added, intra-specific competition of C. squarrosa was observed and increased with increased nutrient availability and more sulfur (S) was allocated to the aboveground partition of the plant. Relative competitive ability of C. squarrosa was greater than that of S. grandis when nutrients were supplied regardless of S. There was no significant difference between shoot and root competition based on dry matter yields. However, root competition was significantly greater than that of shoot based on S uptake under all treatments. A significant interaction was not observed between shoot and root competition. Therefore, nutrients addition benefits the restoration of degraded grassland of C. squarrosa, which may not exclude S. grandis. Also productivity and forage quality of the community will be increased. (C) 2007 Elsevier Ltd. All rights reserved.

Defoliation, nitrogen, and competition: effects on plant growth and resource allocation of Cleistogenes squarrosa and Artemisia frigida

Two species, Artemisia frigida Willd. (C-3, semishrub, and dominant on overgrazed sites) and Cleistogenes squarrosa (Trin.) Keng (C-4, perennial bunchgrass, and dominant or codominant on moderately grazed sites) were studied to determine the effects of defoliation, nitrogen (N) availability, competition, and their interactions on growth, biomass, and N allocation in a greenhouse experiment. The main treatments were: two nitrogen levels (NO = 0 mg N pot(-1), N1 = 60 mg N pot(-1)), two defoliation intensities (removing 60% of total aboveground biomass and no defoliation), and three competitive replacement series (monocultures of each species and mixtures at 0.5:0.5). Our results were inconsistent with our hypothesis on the adaptive mechanisms of A. frigida regarding the interactive effects of herbivory, N, and competition in determining its dominant position on overgrazed sites. Cleistogenes squarrosa will be replaced by A. frigida on over-grazed sites, although C. squarrosa had higher tolerance to defoliation than did A. frigida. Total biomass and N yield and N-15 recovery of C. squarrosa in mixed culture were consistently lower than in monocultures, whereas those of A. frigida grown in mixtures were consistently higher than in monocultures, suggesting higher competitive ability of A. frigida. Our results suggest that interspecific competitive ability may be of equal or greater importance than herbivory tolerance in determining herbivore-induced species replacement in semi-arid Inner Mongolian steppe. In addition, the dominance of A. frigida on overgrazed sites has been attributed to its ability to shift plant-plant interactions through (lap colonization, root niche differentiation, and higher resistance to water stress.

Productivity and persistence of perennial grass mixtures under competition from annual weeds in the alpine region of the Qinghai-Tibetan Plateau

In the alpine region of the Qinghai-Tibetan Plateau four indigenous perennial grass species Bromus inermis (BI), Elymus sibiricus (ES), Elymus nutans (EN) and Agropyron cristatum (AC) were cultivated as three mixtures with different compositions and seeding rates, BI + EN, BI + ES + AC and BI + ES + EN + AC. From 1998 to 2001 there were three different weeding treatments: never weeded (CK); weeded on three occasions in the first year (1-y) and weeded on three occasions in both the first and second year (2-y) and their effect of grass combination and interactions on sward productivity and persistence was measured. Intense competitive interference by weedy annuals reduced dry matter (DM) yield of the swards. Grass combination significantly affected sward DM yields, leaf area index (LAI) and foliar canopy cover and also species composition DM and LAI, and species plant cover. Interaction between weeding treatments and grass combination was significant for sward DM yield, LAI and canopy cover, but not on species composition for DM, LAI or species plant cover. Grass mixture BI + ES + EN + AC gave the highest sward DM yield and LAI for both weeding and non-weeding treatments. Species ES and EN were competitively superior to the others. Annual weedy forbs must be controlled to obtain productive and stable mixtures of perennial grasses, and germination/emergence is the most important time for removal. Weeding three times (late May, late June and mid-July) in the establishment year is enough to maintain the production and persistence of perennial grass mixtures in the following growing seasons. Extra weeding three times in the second growing year makes only a slight improvement in productivity.

A trait specific model of competition in a spatially structured plant community

John Warren and Chris Topping (2004). A trait specific model of competition in a spatially structured plant community. Ecological Modelling, 180 pp.477-485 RAE2008

Linking Attention to Learning, Expectation, Competition, and Consciousness

The concept of attention has been used in many senses, often without clarifying how or why attention works as it does. Attention, like consciousness, is often described in a disembodied way. The present article summarizes neural models and supportive data and how attention is linked to processes of learning, expectation, competition, and consciousness. A key them is that attention modulates cortical self-organization and stability. Perceptual and cognitive neocortex is organized into six main cell layers, with characteristic sub-lamina. Attention is part of unified design of bottom-up, horizontal, and top-down interactions among indentified cells in laminar cortical circuits. Neural models clarify how attention may be allocated during processes of visual perception, learning and search; auditory streaming and speech perception; movement target selection during sensory-motor control; mental imagery and fantasy; and hallucination during mental disorders, among other processes.

REQUIRED VIOLA REPERTOIRE FOR THE PRIMROSE COMPETITION AND THE TERTIS COMPETITION

William Primrose (1903-1982) and Lionel Tertis (1876-1975) made the viola a grand instrument for public performances of solo and chamber music throughout their long and active lives characterized by a common passion for the viola. I, too, have been deeply inspired by their passion for the viola. I chose, therefore, for my doctoral performance project to feature works for viola from the required repertoire of the William Primrose and Lionel Tertis competitions of 2001 and 2003, respectively. For purposes of the performances, I divided selections from the combined repertoire for the William Primrose and Lionel Tertis competitions into three recitals. The first recital included Sonata, Opus 120, No.2 in E-flat Major (1894) by Johannes Brahms; Sonata, Opus 147 (1975) by Dmitri Shostakovich; and Sonata (1919) by Rebecca Clarke. These pieces represent standard components of the general repertoire for both the Primrose and Tertis competitions. The second recital was comprised of two works dedicated by their composers to Primrose: Lachrymae, Opus 48 (1950) by Benjamin Britten; and Concerto (1945) by Bela Bartok. The third recital included three pieces dedicated by their composers to Tertis: Sonata (1922) by Arnold Bax; Sonata in C Minor (1905) by York Bowen; and Sonata (1952) by Arthur Bliss. The goal of my preparation for these recitals was to emphasize a variety of techniques and, also, the unique timbre of the viola. For example, the works I selected emphasized high-position technique, which was not much used before the nineteenth century, and featured the lowest string (the C-string), which provides a beautifully somber and austere sonority characteristic of the viola. For these reasons, the selected works provided not only attractive and interesting pieces to study and perform but were also of educational merit.

Managing dynamic competition

In many important high-technology markets, including software development, data processing, communications, aeronautics, and defense, suppliers learn through experience how to provide better service at lower cost. This paper examines how a buyer designs dynamic competition among rival suppliers to exploit learning economies while minimizing the costs of becoming locked in to one producer. Strategies for controlling dynamic competition include the handicapping of more efficient suppliers in procurement competitions, the protection and allocation of intellectual property, and the sharing of information among rival suppliers. (JEL C73, D44, L10).

Entry and competition in generic biologics

Patents for several blockbuster biological products are expected to expire soon. The Food and Drug Administration is examining whether biologies can and should be treated like pharmaceuticals with regard to generics. In contrast with pharmaceuticals, which are manufactured through chemical synthesis, biologies are manufactured through fermentation, a process that is more variable and costly. Regulators might require extensive clinical testing of generic biologies to demonstrate equivalence to the branded product. The focus of the debate on generic biologies has been on legal and health concerns, but there are important economic implications. We combine a theoretical model of generic biologies with regression estimates from generic pharmaceuticals to estimate market entry and prices in the generic biologic market. We find that generic biologies will have high fixed costs from clinical testing and from manufacturing, so there will be less entry than would be expected for generic pharmaceuticals. With fewer generic competitors, generic biologies will be relatively close in price to branded biologies. Policy makers should be prudent in estimating financial benefits of generic biologies for consumers and payers. We also examine possible government strategies to promote generic competition. Copyright © 2007 John Wiley & Sons, Ltd.

Evolving brand-name and generic drug competition may warrant a revision of the Hatch-Waxman Act.

The evolution of pharmaceutical competition since Congress passed the Hatch-Waxman Act in 1984 raises questions about whether the act's intended balance of incentives for cost savings and continued innovation has been achieved. Generic drug usage and challenges to brand-name drugs' patents have increased markedly, resulting in greatly increased cost savings but also potentially reduced incentives for innovators. Congress should review whether Hatch-Waxman is achieving its intended purpose of balancing incentives for generics and innovation. It also should consider whether the law should be amended so that some of its provisions are brought more in line with recently enacted legislation governing approval of so-called biosimilars, or the corollary for biologics of generic competition for small-molecule drugs.

Decision making across social contexts: Competition increases preferences for risk in chimpanzees and bonobos

Context can have a powerful influence on decision-making strategies in humans. In particular, people sometimes shift their economic preferences depending on the broader social context, such as the presence of potential competitors or mating partners. Despite the important role of competition in primate conspecific interactions, as well as evidence that competitive social contexts impact primates' social cognitive skills, there has been little study of how social context influences the strategies that nonhumans show when making decisions about the value of resources. Here we investigate the impact of social context on preferences for risk (variability in payoffs) in our two closest phylogenetic relatives, chimpanzees, Pan troglodytes, and bonobos, Pan paniscus. In a first study, we examine the impact of competition on patterns of risky choice. In a second study, we examine whether a positive play context affects risky choices. We find that (1) apes are more likely to choose the risky option when making decisions in a competitive context; and (2) the play context did not influence their risk preferences. Overall these results suggest that some types of social contexts can shift patterns of decision making in nonhuman apes, much like in humans. Comparative studies of chimpanzees and bonobos can therefore help illuminate the evolutionary processes shaping human economic behaviour. © 2012 The Association for the Study of Animal Behaviour.