Concave Manner Research Articles

Step-by-Step Nanoscale Top-Down Blocking and Etching Lead to Nanohexapods with Cartesian Geometry.

In this research, we designed a stepwise synthetic method for Au@Pt hexapods where six elongated Au pods are arranged in a pairwise perpendicular fashion, sharing a common point (the central origin in a Cartesian-coordinate-like hexapod shape), featured with tip-selectively decorated Pt square nanoplates. Au@Pt hexapods were successfully synthesized by applying three distinctive chemical reactions in a stepwise manner. The Pt adatoms formed discontinuous thin nanoplates that selectively covered six concave facets of a Au truncated octahedron and served as etching masks in the succeeding etching process, which prevented underlying Au atoms from being oxidized. The subsequent isotropic etching proceeded radially, starting from the bare Au surface, carving the central nanocrystal in a concave manner. By controlling the etching conditions, Au@Pt hexapods were successfully fabricated, wherein the core Au domain is connected to six protruding arms, which hold Pt nanoplates at the ends. Due to their morphology, Au@Pt hexapods feature distinctive optical properties in the near-infrared region, as a proof of concept, allowing for surface-enhanced Raman spectroscopy (SERS)-based monitoring of in situ CO electrooxidation. We further extended our synthetic library by tailoring the size of the Pt nanoplates and neck widths of Au branches, demonstrating the validity of selective blocking and etching-based colloidal synthesis.

Sharing land via keystone structure: Retaining naturally regenerated trees may efficiently benefit birds in plantations.

Meeting food/wood demands with increasing human population and per-capita consumption is a pressing conservation issue, and is often framed as a choice between land sparing and land sharing. Although most empirical studies comparing the efficacy of land sparing and sharing supported land sparing, land sharing may be more efficient if its performance is tested by rigorous experimental design and habitat structures providing crucial resources for various species-keystone structures-are clearly involved. We launched a manipulative experiment to retain naturally regenerated broad-leaved trees when harvesting conifer plantations in central Hokkaido, northern Japan. We surveyed birds in harvested treatments, unharvested plantation controls, and natural forest references 1-year before the harvest and for three consecutive postharvest years. We developed a hierarchical community model separating abundance and space use (territorial proportion overlapping treatment plots) subject to imperfect detection to assess population consequences of retention harvesting. Application of the model to our data showed that retaining some broad-leaved trees increased the total abundance of forest birds over the harvest rotation cycle. Specifically, a preharvest survey showed that the amount of broad-leaved trees increased forest bird abundance in a concave manner (i.e., in the form of diminishing returns). After harvesting, a small amount of retained broad-leaved trees mitigated negative harvesting impacts on abundance, although retention harvesting reduced the space use. Nevertheless, positive retention effects on the postharvest bird density as the product of abundance and space use exhibited a concave form. Thus, small profit reductions were shown to yield large increases in forest bird abundance. The difference in bird abundance between clearcutting and low amounts of broad-leaved tree retention increased slightly from the first to second postharvesting years. We conclude that retaining a small amount of broad-leaved trees may be a cost-effective on-site conservation approach for the management of conifer plantations. The retention of 20-30 broad-leaved trees per ha may be sufficient to maintain higher forest bird abundance than clearcutting over the rotation cycle. Retention approaches can be incorporated into management systems using certification schemes and best management practices. Developing an awareness of the roles and values of naturally regenerated trees is needed to diversify plantations.

Investigation on the Air Permeability and Pore Structure of Concrete Subjected to Carbonation under Compressive Stress.

Concrete structures have to withstand the combined effects of external load and environmental factors. Therefore, it is meaningful to study the durability of concrete under compression and carbonation. The air permeability coefficient (kAu) and pore structure of concrete under uniaxial compression and carbonation were measured by the Autoclam method and mercury intrusion porosimetry (MIP). The Autoclam test results showed that the concrete kAu changed in a concave parabolic manner with the compressive stress level, and the inflection point of the stress level was 45%. The MIP results showed that the characteristic pore structural parameters (porosity, average pore diameter, median pore diameter by area, and median pore diameter by volume) first decreased and then increased with the stress level change. The change in concrete microstructure was a result of the combined effect of pore filling, decalcification, and densification, as well as the split effect. The key pore structural parameters affecting kAu were confirmed using gray relational analysis (GRA). The top three parameters with the highest correlation with the carbonated concrete kAu were porosity (gray relational grade γi = 0.789), median pore diameter by volume (γi = 0.763), and proportion of transition pore volume (γi = 0.827). Furthermore, the regression analysis showed a good linear relation between kAu and the important pore structural parameters.

Soft tissue phenotype modification predicts gingival margin long-term (10-year) stability: Longitudinal analysis of six randomized clinical trials.

AimTo assess the prognostic value of soft tissue phenotype modification following root coverage procedures for predicting the long‐term (10‐year) behaviour of the gingival margin.Materials and MethodsParticipants from six randomized clinical trials on root coverage procedures at the University of Michigan were re‐invited for a longitudinal evaluation. Clinical measurements were obtained by two calibrated examiners. A data‐driven approach to model selection with Akaike information criterion (AIC) was carried out via multilevel regression analyses and partial regression plotting for changes in the level of the gingival margin over time and interactions with the early (6‐month) results of soft tissue phenotypic modification.ResultsOne‐hundred and fifty‐seven treated sites in 83 patients were re‐assessed at the long‐term recall. AIC‐driven model selection and regression analyses demonstrated that 6‐month keratinized tissue width (KTW) and gingival thickness (GT) influenced the trajectory of the gingival margin similarly in a concave manner; however, GT was the driving determinant that predicted significantly less relapse in the treatments, with stability of the treated gingival margin obtained beyond values of 1.46 mm.ConclusionsAmong a compliant patient cohort, irrespective of the rendered therapy, the presence of at least 1.5 mm KTW and 1.46 mm GT was correlated with the long‐term stability of the gingival margin.

Award scheme in random trial contests

Innovation contests have been an important tool used in product research and development for companies. In the innovation contest literature, most papers assume the homogenous innovation contest model or the all-pay auction model. In this paper, we consider the random trial contest model and study the optimal award scheme. We show that, in this contest model, risk types of contestants play important roles in the award scheme, and the results are independent of the probability density function of the random shock. These generalize the work in literature. In addition, the risk aversion coefficient will decide the allocation manner in a multiple-winner scheme, i.e., a concave allocation manner or a convex allocation manner is optimal.

On the asymptotic decay of the Schrödinger–Newton ground state

The asymptotics of the ground state u(r) of the Schrödinger–Newton equation in R3 was determined by V. Moroz and J. van Schaftingen to be u(r)∼Ae−r/r1−‖u‖22/8π for some A>0, in units in which the ground state energy is −1. They left open the value of ‖u‖22, the squared L2 norm of u. Here it is rigorously shown that 21/33π2⩽‖u‖22⩽27/2π3/2. It is reported that numerically ‖u‖22≈14.03π, revealing that the monomial prefactor of e−r increases with r in a concave manner. Asymptotic results are proposed for the Schrödinger–Newton equation with external ∼−K/r potential, and for the related Hartree equation of a bosonic atom or ion.

Ecosystem Service-Based Sensitivity Analyses of i-Tree Eco

"Trees are known to provide various ecosystem services and disservices to urban communities, which can be quantified using models based on field and environmental data. It is often uncertain how tree structure and environmental variables impact model output. Here we perform a sensitivity analysis (SA) of i-Tree Eco, a common urban forest model, to analyze the relative impact of different model inputs on three module outputs: biogenic volatile organic compound (BVOC)(isoprene and monoterpenes) emissions, carbon storage and sequestration, and dry deposition of nitrogen dioxide, sulfur dioxide, and ozone. The SA methods included novel applications of the Morris one-at-a-time method and a variance-based decomposition method, which integrates Monte Carlo simulation with Latin hypercube sampling and Iman Conover analysis. A case study was performed in New York City, New York, USA, with field plot data collected in 2013. Genus has the largest influence on BVOC emissions by determining base emission rates and its high interactions with other input factors, and BVOC emissions are sensitive to leaf biomass in a concave manner and temperature in a convex manner, while isoprene emissions show a strong linear relationship with photosynthetically active radiation (PAR). Diameter at breast height plays the most important role for both carbon storage and sequestration estimators; crown light exposure and tree condition are also important for carbon sequestration. Dry deposition velocity is sensitive to leaf area index and relative humidity in a nearly linear way, while sensitive to temperature and PAR in a concave manner. The results provide guidance to facilitate future field plot campaigns and model development. The knowledge revealed by the SA is also beneficial for model uncertainty reduction, which in turn facilitates more effective urban forest management and decision-making.

Knowledge Recombination and Inventor Networks: The Asymmetric Effects of Embeddedness on Knowledge Reuse and Impact

Inventors are triply embedded. They are embedded in a network of knowledge components that they can reuse in future inventions. They are embedded in an inventor network, where internal embeddedness (the strength of relationships between focal inventors and their colleagues upon whose knowledge the team builds) and network centrality influence access to information. Finally, they are embedded in the firm, with its specific routines that favor external or internal knowledge search, what we call search orientation. Using a sample of 39,785 semiconductor patents, we study the pattern of knowledge reuse, or the recombination of technologically similar components, on invention impact. We propose that reuse of internal knowledge affects invention impact in a concave manner and posit that internal embeddedness steepens this relationship while network centrality leads to an inflection point shift. We examine whether these effects differ for subsamples of firms with inward- or outward-looking search orientation. We find that inward-looking firms’ optimal pattern of internal knowledge reuse does not differ markedly from that of outward-looking firms. We find that inward-looking firms are more susceptible to internal embeddedness and that centrality in the collaborative network flattens rather than shifts the relationship between reuse and impact. These findings elevate the theoretical discourse of embeddedness from the effects of network positions on innovation outcomes to similar network positions having asymmetric effects that vary with the firm’s search orientation. Our results contribute to an emergent area in innovation research on how inventor networks shape the inventive process and its outcomes.

In-Store Spending Dynamics: How Budgets Invert Relative-Spending Patterns

Abstract The authors conduct four controlled lab experiments and one field study in a brick-and-mortar grocery store to demonstrate that relative spending—the price of the purchased item relative to the mean price of the product category—evolves nonlinearly and distinctly for budget and nonbudget shoppers. While the relative spending of budget shoppers evolves in a concave manner, the relative spending of nonbudget shoppers evolves inversely in a convex manner. Thus, budget (nonbudget) shoppers spend relatively more (less) in the middle than at the beginning and toward the end of their shopping trip. Mediation analyses confirm that the pain of paying experienced while shopping drives price salience, which then drives relative spending. Moreover, manipulating shoppers’ pain of paying, by altering the opportunity costs associated with their spending or drawing shoppers’ attention to their spending via real-time spending feedback, is shown to influence these spending patterns. The research offers theoretical contributions to the in-store decision-making, budgeting, and pain-of-paying literature and has important implications for marketing and promotion strategies in retail and mobile technology environments, as it suggests when a shopper may be more sensitive to price-related factors.

Across-trophic variation of potassium, calcium and magnesium stoichiometric traits in a parasitism food chain across temperate and subtropical biomes

Potassium (K), calcium (Ca) and magnesium (Mg) are three macro-elements essential for plants and animals. The ratios K : Mg or K : (Ca + Mg) are viewed as indices of physiological status in livestock animals. In plants, Ca, Mg and K concentrations can vary with climate in terrestrial ecosystems. Here, with a widespread tree species (Chinese cork oak, Quercus variabilis Blume) and an acorn predator (the weevil Curculio davidi Fairmaire), we investigate how K, Ca and Mg vary in soils, plant tissues (leaves and acorns) and a consumer (herbivore insects) with climatic variables induced by latitude (LAT) across the temperate–subtropical areas of eastern China. Concentrations of K, Ca and Mg in soils, leaves, acorns and weevil larvae showed different degrees of variation across the study area, but only Mg concentration increased significantly with rising LAT across all four trophic levels, albeit with varying slopes. With rising mean annual temperature (MAT) and precipitation (MAP), soil Ca significantly decreased, as did leaf and acorn K concentrations, whereas all four tropic levels showed significant decreases in Mg content with both MAT and MAP (P < 0.05–0.001). Leaf and acorn Ca : Mg showed significant relationships with LAT and MAT (P < 0.05–0.01). The K : (Mg + Ca) ratio in soils and weevil larvae increased linearly with MAP (P < 0.05), and acorn K : (Mg + Ca) ratio varied in a concave manner (P < 0.001). Our results suggest that variations of Ca, Mg and K in plant tissues and weevil larva across a study area of 20° LAT range were largely driven by climatic factors, and that Mg concentration changes in all four trophic levels with climate (and LAT) largely drive changes in soil, plant and consumer ratios between Mg, Ca and/or K. These results provide information on possible effects of climate change on nutrient dynamics in terrestrial ecosystems.

Anisotropic Strain Effect on Electron Transport in C60Organic Field Effect transistors

ABSTRACTMechanical flexibility is one of the key advantages of organic semiconducting films in applications such as wearable-electronics or flexible displays. The present study is aimed at gaining deeper insight into the effect of strain on charge transport properties of the organic semiconductor films. We have fabricated high performance C60top gate organic field effect transistors (OFET) on flexible substrates and characterized the devices by curling the substrates in concave and convex manner, to apply varying values of compressive and tensile strain, respectively. Electron mobility is found to increase with compressive strain and decrease with tensile strain. The observed strain effect is found to be strongly anisotropic with respect to the direction of flow of current. This observation on mobility is quantified using an Extended Gaussian Disorder Model (EGDM) for the hopping charge transport. We suggest that the observed strain dependence of the electron transport is dominated by a change in the effective charge hopping distance over the grain boundaries in polycrystalline C60films.

Derivatives of (-)-Isosteviol with Expanded Ring D and Various Oxygen Functionalities

(–)-Isosteviol is a unique ex-chiral-pool building block that is readily available. Both functional groups are aligned in a concave manner. The methyl moiety on the backbone also points in this direction, creating a strong asymmetric environment close to these functional groups. The slightly divergent orientation of the keto and carboxy functions limits its use in the construction of supramolecular architectures as optically pure divalent building blocks. By selective transformations, ring D of (–)-isosteviol can be expanded and equipped with oxygen-containing functionalities, providing a variety of useful and rigid building blocks with defined stereochemistry.

Differences in masticatory function of subjects with different closing path

The purpose of this study was to clarify whether there was a difference in the masticatory function between two masticatory path patterns: a convex closing path and a concave closing path. For 80 healthy subjects, the masticatory function (masticatory muscular activity, mandibular movement, and masticatory performance) when chewing a gummy jelly was recorded. Out of the 160 chewing cases (80 subjects chewing on either side), 65 cases (Group I) in which the incisal point opened in a linear or concave manner toward the working side and closed in a convex manner, and 15 cases (Group II) in which the opening path was the same as that in Group I, but the closing followed a concave path, were selected. For the masticatory function, the integral values per unit time of masseter and temporal muscular activities, the gape and masticatory width, the indicators representing the stability of movement path, and the glucose extraction from chewing gummy jelly were measured and compared between the two groups. The integral values of muscular activities and the amount of glucose extraction were significantly greater in Group I. The gape and masticatory width were not significantly different between the groups. The values of the indicators representing the stability of path were smaller in Group I than in Group II. From these results, it was suggested that there was a functional difference between Group I (with a convex closing path) and Group II (with a concave closing path), and that Group I had a superior masticatory function to Group II.

Structural Performance of Bridge Approach Slabs under Given Embankment Settlement

Soil embankment settlement causes concrete approach slabs of bridges to lose their contact and support from the soil. When soil settlement occurs, the slab will bend in a concave manner that causes a sudden change in slope grade near its ends. Meanwhile, loads on the slab will also redistribute to the ends of the slab, which may result in faulting across the roadway at the ends of the approach slab. Eventually, the rideability of the bridge approach slab will deteriorate. The current American Association of State Highway Transportation Officials code specifications do not provide clear guidelines to design approach slabs considering the embankment settlements. State Departments of Transportation are spending millions of dollars each year to deal with problems near the ends of approach slabs. To investigate the effect of embankment settlements on the performance of the approach slab, a three-dimensional finite element analysis was conducted in the present study, considering the interaction between the approach slab and the embankment soil, and consequently the separation of the slab and soil. The predicted internal moments of the approach slab provide design engineers with a scientific basis to properly design the approach slab considering different levels of embankment settlements. A proper design of the approach slab will help mitigate the rideability problems of the slab.

Profits, Losses and the Non-Linear Pricing of Internet Stocks

This paper sheds light on the economics of Internet firms by extracting information on major value-drivers from their stock prices. Contrary to conventional Wall Street wisdom that there is little or no method in the pricing of Net stocks, I find that basic accounting data are highly value-relevant in a simple nonlinear manner. Using log-linear regression on quarterly data for 167 Net firms over the period 1997:Q1?1999:Q2, I show that Net firms' market values are linear and increasing in book equity, but concave and increasing (decreasing) in positive (negative) net income. When Net firms' earnings are decomposed into revenues and expenses, revenues are found to be weakly positively priced. In contrast, and consistent with the argument that very large marketing costs are intangible assets, not period expenses, Net firms' market values are reliably positive and concave in selling and marketing expenses when net income is negative, particularly during the first two fiscal quarters after the IPO. R&D expenditures are priced in a similarly concave manner, although more durably beyond the IPO than are marketing costs. The concavity in the pricing of core net income, R&D costs, and selling and marketing expenses runs counter to the notion that Net firms are expected to benefit from extraordinary profitability stemming from large strategic operating options, or increasing returns-to-scale.

Minimal Radius of Curvature of Lipid Bilayers in the Gel Phase State Corresponds to the Dimension of Biomembrane Structures “Caveolae”

Caveolae are membrane invaginations with a radius of curvature in the range of 40 nm for the bulb; 10–15 nm is the minimal radius for lipid bilayers in the liquid-crystalline Lα(liquid-disordered:ld) phase state. A minimal radius of 20–30 nm could be detected for the gel phase state by analysis of convex–concave bilayer deformations. Circular protrusions with a diameter in the range of only about 40 nm are closed by a flat lid, and those with diameters of 60 nm or more are closed by hemispherical caps. These structures are found primarily in phosphatidylcholine/sterol mixtures, where the gel phase state “liquid ordered” (lo) has been introduced. As a further example the mixture of dimyristoylphosphatidylcholine (DMPC) with an unusual sterol (diflucortolon-21-valerat) is presented. In the usual hydration at temperatures above the phase transition the deformation requires an incubation at 4°C for several weeks or months to form. Using a low temperature hydration procedure (at 4°C), surprisingly bilayers of pure DMPC and DPPC (dipalmitoylphosphatidylcholine) are found to deform in the same convex–concave manner, and this takes place within hours and days. The dependence on hydration protocol is also observed for formation of a sponge-like bilayer network with 30–35 nm radius of curvature in brain sphingomyelin and its mixtures with cholesterol. Caveolae are microdomains enriched in cholesterol and sphingomyelin and are simultaneously discussed to be in thelostate. Direct evidence by investigation of bilayers formed by the lipids isolated from caveolae is still lacking, but structures similar to caveolae which are in the gel phase state (very probably thelostate) are also formed by lipids extracted from bacterial membranes. A further analogy exists because both natural lipid mixtures (brain sphingomyelin and bacterial lipids) transform during heating from the curved bilayer structures into microvesicles above the phase transition. Internalization of caveolae is a process of vesicle formation.

Shoot water relations and gas exchange of western hemlock and western red cedar seedlings during establishment on a reforestation site

Shoot water relations, summer gas exchange response and morphological development of western hemlock [Tsuga heterophylla (Raf.) Sarg.] and western red cedar (Thuja plicata Donn) seedlings were monitored over the first growing season on a coastal reforestation site in British Columbia. In March, osmotic potential (ψs) at saturation [ψs(sat)] was −1.98 MPa and turgor loss point [ψs(tlp)] −2.38 MPa for western hemlock, while western red cedar had −1.45 MPa ψs(sat) and −1.93 MPa ψs(tlp). Seasonally ψs increased through June and then decreased through September, with western hemlock −0.15 to −0.50 MPa lower than western red cedar. Maximum bulk modulus of elasticity (ɛmax) for western hemlock was 29.3 MPa in March, decreased to 15.0 MPa in June and increased to 25.0 MPa from July through September, while western red cedar ɛmax was 10.6 MPa in March and around 8.0 MPa thereafter. Utilized turgor (Tutil) for western hemlock was <40% from March through May, 69 to 78% from June through August and 96% in September, while western red cedar Tutil was 68 to 73% during March and April, 84 to 96% from May through August and 100% in September. Maximum CO2 assimilation rate (A) of western red cedar was more than double western hemlock, and for both species A declined in a linear fashion with increasing vapour pressure deficit (D). Maximum foliage conductance (gwv) declined in a concave manner as D increased in both species, with western red cedar values 50 to 67% greater than western hemlock. Maximum daily gwv declined in a concave manner as predawn shoot water potential (ψpd) decreased, with maximum daily gwv 1.8 to 3.6 times greater in western red cedar than western hemlock, when ψpd was −0.25 and −1.4 MPa, respectively. Western red cedar, compared to western hemlock, had a greater increase in A as gwv increased. Eight months after planting, western red cedar seedlings had twice the root growth, measured as root dry weight and root number, of western hemlock.

加圧排気鋳造法による粒子強化複合材料の複合化過程の解析

Temperature distribution in the squeeze-exhaust cast composite materials during casting was determined by the temperature measurement at the several portions in the preform. The permeation behavior of the molten metal, the solidification process and the optimal casting conditions (temperatures of mold and molten metal) for the SiO2/Pb composite material were clarified by this method. In order to obtain sound composite materials it is essential that the molten metal front moves from the upper part to the lower part of the preform in the planar or slightly concave manner and that the solidification front, on the contrary, moves from the lower part to the upper one. The casting conditions mentioned above for the fabrication of sound composite materials are limited to a narrow temperature range. In the case of the SiO2/Pb composite material the mold temperature is required not to be lower than Tm (melting point of the matrix), and the temperature of the molten metal is required not to be higher than 1.1Tm.

Gas exchange processes of yellow-cedar (Chamaecyparis nootkatensis) in response to environmental variables

Yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach) gas exchange processes were measured in response to the following primary environmental variables: photosynthetically active radiation, vapour pressure deficit, root temperature, and soil moisture. Under nonlimiting edaphic conditions, maximum stomatal conductance and maximum CO2 assimilation increased rapidly as photosynthetically active radiation increased from 0 to 200 μmol∙m−2∙s−1 and from 0 to 500 μmol∙m−2∙s−1, respectively. Thereafter, greater photosynthetically active radiation levels only resulted in minor increases in stomatal conductance and CO2 assimilation. Maximum stomatal conductance and maximum CO2 assimilation declined in a concave manner as vapour pressure deficit increased from 1 to 5 kPa. Response surface model for stomatal conductance showed vapour pressure deficit was the primary influence after light had caused initial stomatal opening. Response surface modeling approach showed CO2 assimilation increased as photosynthetically active radiation increased, but increased vapour pressure deficit resulted in a suppression of CO2 assimilation. Response surface model showed internal CO2 concentration declined sharply as photosynthetically active radiation increased from 0 to 500 μmol∙m−2∙s−1, but it remained constant with increasing vapour pressure deficit. Decreasing root temperature resulted in a continual decline in CO2 assimilation and stomatal conductance from 22 to 1 °C, while internal CO2 concentration declined from 22 to 13 °C with little change between 13 and 1 °C. As predawn shoot water potential decreased from −0.5 to −2.0 MPa, CO2 assimilation declined in a linear manner, while stomatal conductance and internal CO2 concentration declined in a concave manner. Key words: Chamaecyparis nootkatensis, CO2 assimilation, stomatal conductance, internal CO2 concentration, photosynthetically active radiation, vapour pressure deficit, root temperature, predawn shoot water potential.

The transition from algorithm to retrieval in memory-based theories of automaticity

Two memory-based theories of automaticity were compared. The mixture model and the race model both describe automatization as a transition from algorithmic processing to memory retrieval. The mixture model predicts that, with training, the variability of reaction time will initially increase, and later decrease in a concave downward manner, whereas the race model predicts the variability will decrease only in a concave upward manner. The mixture model predicts that using both algorithm and retrieval on a single trial will be slower than using the algorithm alone, whereas the race model predicts the reverse. The experiments used an alphabet arithmetic task, in which subjects verified equations of the form H + 3 = K and made subjective reports of their strategies on individual trials. Both the variability of reaction times and the pattern of reaction times associated with the strategy reports supported the race model.