Concave-convex Pattern Research Articles

Concave and convex effects of ESG performance on corporate sustainable development: Evidence from China

Research background: Corporate sustainable development (CSD) is essential to a company's success and survival. Environmental, social, and governance (ESG) are regarded as major factors in measuring the impact of CSD. Companies that perform well in terms of ESG can maintain a competitive advantage and achieve sustainable development. Poor management of ESG performance and involvement in controversial activity can harm a company's credibility and reputation in the market, as well as negatively impact sustainable development. Purpose of the article: Drawing on the stakeholder and signaling theories, this paper investigates the curvilinear nexus between ESG performance and CSD. Methods: Empirical studies were conducted on a sample of 697 Chinese listed manufacturing firms that disclosed ESG information from 2010 to 2020, with a total of 5699 firm-year observations. Quantile regression analysis and the U-test were used to examine the curvilinear ESG-CSD relationship. This technique was supplemented by conducting instrumental variables tests and propensity score matching to address concerns relating to the potential existence of endogeneity problems. Findings & value added: The results of the quantile regression estimation confirm the concave-convex (inverted U-shaped and U-shaped) ESG-CSD relationship via the U-test. The relationships between the environmental and social components and CSD follow an inverted U-shaped or half-inverted U-shaped pattern, while the relationship between the governance component and CSD exhibits a concave-convex pattern. A concave ESG-CSD nexus is evident in environmentally sensitive industries, whereas a half concave-convex ESG-CSD nexus is confirmed in non-environmentally sensitive industries. This study improves scholars’ understanding of ESG performance and provides a comprehensive perspective on the double-edged effects (positive and negative consequences) of ESG practices. The instrumentalization of ESG practices for management to seek personal gain has a negative impact on CSD, while ESG practices that add value for stakeholders have a positive impact. These findings provide empirical evidence for Chinese publicly listed manufacturing firms to effectively conduct ESG practices.

Concave-convex effect of financial resilience on corporate financial performance: quantile regression approach

This study not only aims to elucidate the curvilinear nexus between financial resilience (FR) and corporate financial performance (CFP) by drawing on the ‘too much of a good thing (TMGT)’ and ‘too little of a good thing (TLGT)’ effect but also attempts to examine whether the nonlinear relationship explains the conflicts found in previous findings. Data were analyzed from Taiwan publicly listed manufacturing firms amid the COVID-19 epidemic. Quantile regression approach results evidence that relationship between FR and CFP is of a concave-convex pattern. Moreover, the environmentally sensitive and non-sensitive firms are linked to CFP differently. The nexus between FR and CFP is concave for the environmentally sensitive firms, whereas the FR-CFP nexus is concave-convex for the environmentally non-sensitive firms. Overall, Taiwan’s manufacturing firms should carefully evaluate how capital is allocated to FR to avoid under- or over-investment in FR.

Programmable and scalable assembly of a flexible hexagonal DNA origami

Nanoscale structures demonstrate considerable potential utility in the construction of nanorobots, nanomachines, and many other devices. In this study, a hexagonal DNA origami ring was assembled and visualized via atomic force microscopy. The DNA origami shape could be programmed into either a hexagonal or linear shape with an open or folded pattern. The flexible origami was robust and switchable for dynamic pattern recognition. Its edges were folded by six bundles of DNA helices, which could be opened or folded in a honeycomb shape. Additionally, the edges were programmed into a concave-convex pattern, which enabled linkage between the origami and dipolymers. Furthermore, biotin-streptavidin labels were embedded at each edge for nanoscale calibration. The atomic force microscopy results demonstrated the stability and high-yield of the flexible DNA origami ring. The polymorphous nanostructure is useful for dynamic nano-construction and calibration of structural probes or sensors.

Water infiltration into subcritical water-repellent soils with time-dependent contact angle

Soil water repellency, defined as the situation in which the affinity of soils to water is reduced, has been reported for many natural and agricultural soils worldwide. Soil water repellency has significant impacts on hydrology and geomorphology. It has been widely observed that the contact angle (CA) of a sessile water drop placed on a single-layer surface of water-repellent soil particles decreases in an exponential manner with time. This time-dependent CA has a substantial effect on flow in water-repellent soils. However, mathematical models aimed at modeling water flow in water-repellent soils disregard the time-dependent CA's effect. The current study aims to correct this omission. Using capillary rise of water with a time-dependent CA in a capillary tube, a model for water infiltration into subcritical water-repellent soils (CA < 90°) was developed. This model was successfully verified by performing infiltration experiments into (packed) coated glass beads. The CA at the wetting front during infiltration decreased exponentially to equilibrium, and the time to equilibrium was similar to that measured for a reference single layer of coated glass beads. Simulations for subcritical water-repellent soils with time-dependent CA yielded an infiltration rate that is either increasing with time (noted as concave) or initially increases and afterward decreases (noted as a concave-convex pattern).

Meshing characteristic analysis of a cycloid drive with epitrochoid profile and its conjugate envelope

Cycloid drives are widely adopted in the areas of industry robot, aerospace, automotive, etc., due to the advantages of large ratio, compact size and light weight. To improve the transmission efficiency and the load capability, a novel geometric design of the cycloid drive is presented based on coordinate transformation and envelope theory, including the profile generation and modification. The conjugate gear tooth pair is a concave-convex pattern of contact and composed by the epitrochoid profile and its conjugate envelope profile modified by a small fillet. The meshing characteristics, such as the contact zones, contact ratio, sliding coefficients and induced normal curvature are analyzed to estimate the performance of the proposed cycloid drive. The influence of those characteristics in varied geometrical design parameters is also discussed for optimal design. The contact stress is analyzed by using finite element method and a comparison study is conducted to compare with the conventional cycloid drive. The contact stress and sliding coefficients demonstrate a salient feature of the proposed cycloid drive.

A planície costeira holocênica de Campos Verdes (Laguna, SC): evolução sedimentar inferida a partir de georradar (GPR), granulometria e minerais pesados

Campos Verdes region, in Laguna, mid-south coast of Santa Catarina, is characterized by sets of beach ridges alignments, oriented transversal to the present coastline and separated from each other by truncations with a concave-convex pattern. This strandplain is limited towards SW by a higher area (1m) without beach ridges, where four shell mounds are located. The alignments are superposed by several groups of inactive parabolic dunes, attributed to the aeolian generation 3 (post maximum Holocene flooding). The sedimentary growing began in the southwest (higher area), where the former beach ridges developed anchored on a sandy spit. This spit was formed according to the Zenkovitch’s models of lagoonal circulation; moreover, it would have worked as a “trap” for the accumulation of sediments that formed the strandplain. This hypothesis is highlighted by the GPR sections, with reflectors dipping towards N, indication of progradation towards this azimuth. The McLaren’s granulometric variation pattern of “fining, better sorting and more negative skewness” towards N can be interpreted as resulting from a progressive sedimentary reworking during progradation. In a longitudinal profile, the pattern of “coarsening, better sorting and more positive skewness” towards W, suggests transport by longshore currents towards this azimuth. The variation in the heavy minerals assemblage shows a higher concentration of unstable components in opposite to the decrease of ultrastable components towards N and W, with an increase in the relation tourmaline/zircon towards NW. This decreasing mineralogical maturity towards the sector formed in the end of the progradation can be attributed to three factors: 1. progressive concentration by hydraulic sorting; 2. increase in the sedimentary input of newer sediments, because of the stronger influence of Tubarao river deltaic front; and 3. least time for the action of pos-depositional solution in the newer beach ridges.

A planície costeira holocênica de Campos Verdes (Laguna, SC): evolução sedimentar inferida a partir de georradar (GPR), granulometria e minerais pesados

Campos Verdes region, in Laguna, mid-south coast of Santa Catarina, is characterized by sets of beach ridges alignments, oriented transversal to the present coastline and separated from each other by truncations with a concave-convex pattern. This strandplain is limited towards SW by a higher area (1m) without beach ridges, where four shell mounds are located. The alignments are superposed by several groups of inactive parabolic dunes, attributed to the aeolian generation 3 (post maximum Holocene flooding). The sedimentary growing began in the southwest (higher area), where the former beach ridges developed anchored on a sandy spit. This spit was formed according to the Zenkovitch’s models of lagoonal circulation; moreover, it would have worked as a “trap” for the accumulation of sediments that formed the strandplain. This hypothesis is highlighted by the GPR sections, with reflectors dipping towards N, indication of progradation towards this azimuth. The McLaren’s granulometric variation pattern of “fining, better sorting and more negative skewness” towards N can be interpreted as resulting from a progressive sedimentary reworking during progradation. In a longitudinal profile, the pattern of “coarsening, better sorting and more positive skewness” towards W, suggests transport by longshore currents towards this azimuth. The variation in the heavy minerals assemblage shows a higher concentration of unstable components in opposite to the decrease of ultrastable components towards N and W, with an increase in the relation tourmaline/zircon towards NW. This decreasing mineralogical maturity towards the sector formed in the end of the progradation can be attributed to three factors: 1. progressive concentration by hydraulic sorting; 2. increase in the sedimentary input of newer sediments, because of the stronger influence of Tubarão river deltaic front; and 3. least time for the action of pos-depositional solution in the newer beach ridges.

Pharmacokinetics and pharmacodynamics of a therapeutic dose of unfractionated heparin (200 U/kg) administered subcutaneously or intravenously to healthy dogs

Heparin treatment has been recommended for dogs in hypercoagulable states such as disseminated intravascular coagulation, however, potential benefits have to be balanced against the bleeding risk if overdosage occurs. A better understanding of the pharmacology of heparin and tests to monitor heparin therapy in dogs may help prevent therapeutic hazards. The purpose of this study was to evaluate the effects of 200 U/kg of sodium unfractionated heparin (UFH) on coagulation times in dogs after intravenous (IV) and subcutaneous (SC) administration and to compare these effects with plasma heparin concentrations assessed by its antifactor Xa (aXa) activity. 200 U/kg of UFH were administered IV and SC to 5 healthy adult Beagle dogs with a washout period of at least 3 days. Activated partial thromboplastin time (APTT), prothrombin time (PT), and plasma aXa activity were determined in serial blood samples. After IV injection, PT remained unchanged except for a slight increase in 1 dog; APTT was not measurable (>60 seconds) for 45-90 minutes, and then decreased gradually to baseline values between 150 and 240 minutes. High plasma heparin concentrations were observed (maximal concentration = 4.64 +/-1.4 aXa U/mL) and decreased according to a slightly concave-convex pattern on a semilogarithmic curve, but returned to baseline slightly more slowly (t240-t300 minutes) than did APTT. After SC administration, APTT was moderately prolonged (by a ratio of 1.55 +/-0.28 APTT t0, range 1.35-2.01) between 1 and 4 hours after administration. Plasma aXa activity reached a maximum of 0.56 +/-0.20 aXa U/mL (range 0.42-0.9 U/mL) after 132 +/-26.8 minutes; this lasted for 102 +/-26.8 minutes. Prolongation of APTTs of 120-160% corresponded to plasma heparin concentrations of 0.3-0.7 aXa U/mL. As in humans, the pharmacokinetics of UFH in dogs was nonlinear. Administration of 200 U/kg of UFH SC in healthy dogs resulted in sustained plasma heparin concentrations in accordance with human recommendations for thrombosis treatment or prevention, without excessively increased bleeding risks. In these conditions, APTT can be used as a surrogate to assess plasma heparin concentrations. These findings need to be confirmed in diseased animals.

2227 動的軸圧縮荷重を受けるアルミニウム角管の変形について(S31-1 最新のチューブフォーミングとその動向(1),S31 最新のチューブフォーミングとその動向)

Buckling and impact resistance of dynamic axial compressed aluminum square tube are discussed. The result shows that ripples of buckling are produced in the surfaces of the tube wall when the striking mass reaches a certain values. The wave pattern on the deformed tube wall of 1mm, 1.2mm and 1.5mm thick is concave-convex pattern in adjoining surface, while that of 2mm thick is convex pattern in all surfaces.

Deformation and Energy Absorption of Aluminum Square Tubes with Dynamic Axial Compressive Load

Buckling, impact resistance and energy absorption of dynamic axial compressed aluminum square tube are discussed. Numerical analysis of the deformation of the square tube is made by a finite element method. The result shows that ripples of buckling are produced in the surfaces of the tube wall when the striking mass reaches to a certain value. The wave pattern on the deformed tube wall of 1 mm thick is concave-convex pattern in adjoining surface, while that of 2 mm thick is convex pattern in all surfaces. Absorbed energy of the deformed tube increases in proportion to axial displacement of the tube. Experimental results agree approximately with those of the finite element method analysis.

動的軸圧縮荷重を受けるアルミニウム角管の変形特性とエネルギー吸収特性

Buckling, impact resistance and energy absorption of dynamic axial compressed aluminum square tube are discussed. Numerical analysis of the deformation of the square tube is made by a finite element method. The result shows that ripples of buckling are produced in the surfaces of the tube wall when the striking mass reaches a certain values. The wave pattern on the deformed tube wall of 1 mm thick is concave-convex pattern in adjoining surface, while that of 2 mm thick is convex pattern in all surfaces. Absorbed energy of the deformed tube increases in proportion to axial displacement of the tube. Experimental results agree approximately with those of the finite element method analysis.

Dynamic axial plastic buckling of square tube

The dynamic axial deformation process of a square tube is discussed in order to obtain basic data for buckling and impact resistance. The deformation process is measured by a high-speed camera and is analyzed numerically, based on a finite-element method. The result shows that compressive strain reaches a peak value on the tube wall of the central part of the tube in the axial direction and buckling appears. Unevenness and ripples on the surface of the tube are caused by buckling. The unevenness pattern on the surface is a concave–convex pattern in the adjoining surface. Experimental results agree approximately with those of the finite-element method analysis.

Fabrication of submicrometre 3D periodic structurescomposed of Si/SiO 2

The successful fabrication of 3D periodic structures composed of two transparent materials in the submicrometre range is reported for the first time. The material system comprises a-Si (n=3.26) and SiO/sub 2/ (n=1.46), and sputter-etching leads to 'high-fidelity' layer-to-layer propagation of a concave-convex pattern.

Heparin pharmacokinetics and pharmacodynamics.

Heparin was discovered approximately 75 years ago and has been used extensively for the last 50 years to treat thromboembolic disorders. An endogenous glycosaminoglycan, heparin is found largely in the liver, lung and intestine. It is available for exogenous administration both as unfractionated and low molecular weight heparin. Unfractionated heparin is a heterogenous mixture of polysaccharide chains of varying length resulting in a range of molecular weights from 3000 to 30,000D while low molecular weight heparin ranges from 3000 to 6000D. Heparin produces its antithrombotic effect by binding to antithrombin III and this complex then binds to thrombin. In order to accomplish this a total of 18 to 22 monosaccharide units is necessary including a specific pentasaccharide binding site for antithrombin III. After either subcutaneous or intravenous injection heparin is distributed primarily within the intravascular space. A short distribution phase is seen which is thought to correspond to endothelial cell binding and internalisation. The disposition curve for unfractionated heparin has a unique concave-convex shape which is the result of combined saturable and nonsaturable elimination mechanisms. The nonsaturable elimination mechanism is renal and is the primary route of elimination for low molecular weight heparins. For this reason, the concave-convex pattern is not seen with low molecular weight preparations. Both forms of heparin are useful antithrombotic agents; however, the correlation between the antithrombotic effect and an in vitro laboratory test for either type still needs further clarification.

3 Pharmacokinetics of heparin and low molecular weight heparin

After parenteral injection, heparin is removed from the blood via two mechanisms, saturable and non-saturable. The saturable mechanism represents clearance by the reticuloendothelial system and endothelial cells, to which heparin binds with a high affinity. The non-saturable mechanism is represented by renal excretion. The contribution of the two mechanisms to the clearance of heparin varies according to the dose delivered and the molecular weight of the heparin preparation. At low doses, unfractionated heparin (UH) is removed mainly via the saturable mechanism, while at higher doses the contribution of the non-saturable mechanism to its clearance becomes pre-eminent. This model accounts for the major pharmacokinetic properties of UH. After bolus intravenous injection of low doses, UH disappears from the blood exponentially with a dose-dependent half-life; at higher doses, UH disappears with a concave-convex pattern. Under continuous intravenous infusion there is a non-linear relationship between the dose of UH injected and the steady-state plasma concentration. After subcutaneous injection, the bioavailability of the anti-factor Xa activity increases with the dose delivered and tends toward 100% at high doses. In contrast, low molecular weight heparins (LMWH) are mainly removed by non-saturable renal excretion. This explains the dose independence of the pharmacokinetic parameters of LMWH, the excellent bioavailability of the subcutaneous route at any dose, and the prolongation of LMWH half-life in cases of chronic renal insufficiency. However, the model does not explain the large interindividual variability of the pharmacokinetic parameters of both UH and LMWH.

Effects of increased sulfation of dermatan sulfate on its in vitro and in vivo pharmacological properties

The in vitro and in vivo pharmacological properties of two oversulfated dermatan sulfate (DS) derivatives, S-DS1 and S-DS2, containing 2 and 3.7 sulfate groups / disaccharide unit respectively were compared to those of the parent DS (1 sulfate group / disaccharide unit). In a purified system the ability of S-DS1 and of S-DS2 to catalyse thrombin inhibition by heparin cofactor II was increased by ten- and seventeen-fold respectively. These compounds also had more potent anticoagulant activities in the activated partial thromboplastin time and the thrombin clotting time assays. Plasmas immunodepleted in antithrombin III, heparin cofactor II and both cofactors allowed it to be demonstrated that these enhanced anticoagulant activities were partly (S-DS1) or totally (S-SD2) independent of any plasma cofactors. In spite of these enhanced anticoagulant activities in vitro the oversulfated derivatives did not exhibit an increased antithrombotic activity in a thromboplastin Wessler type model. Moreover, at the doses investigated, S-DS2 had no antithrombotic effect. The influence of oversulfation on the pharmacokinetic pattern of DS was also investigated. As reported for unfractionated heparin, the biological activities generated after IV injection of high doses of S-DS1 and S-DS2 disappeared according to a concaveconvex pattern. This may result from the higher affinities of S-DS1 and of S-DS2 toward endothelial cells in comparison with that of DS.

Evidence for a saturable mechanism of disappearance of standard heparin in rabbits

This work demonstrates that after bolus intravenous injection standard heparin (SH) disappearance results from the combination of a saturable and a non saturable mechanism. Pharmacokinetics and pharmacodynamics of SH were studied by measuring the disappearance of increa-sing doses (5 – 500 anti-factor Xa U/kg) of 125I-heparin and of its biological effects. CPM curves allowed to determine the half lives of heparin according to the dose injected. The half lives were clearly dose dependent and reached a plateau over 100 anti-factor Xa U/kg. The complex curve which describes the amount of heparin cleared per time unit after any given dose has been resolved into its two components reflecting a saturable and a non saturable mechanism of disappearance. For the doses <100 anti-factor Xa U/kg the saturable mechanism was preeminent and the anti-factor Xa activity disappearance followed an exponential pattern ; for the doses >100 anti-factor Xa U/kg the contribution of the non saturable mechanism becames more important and the anti-factor Xa activity disappearance followed a concave-convex pattern. Further experiments showed that the heparin half life shortened as the circulating anti-factor Xa activity decreased ; this phenomenon may explain the concave-convex pattern of the curve of the anticoagulant effect observed after injection of large doses of SH.