Application of the concept of the criterion of equivalence of complex stress state to simple tension for assessing the fatigue resistance of structural materials. Part 1. Review of some experimental data with the preparation of the necessary information for subsequent use

A brief overview of the features of the fatigue resistance of some steels is given with the selection of terms, concepts and numerical data necessary for the subsequent compilation and verification of the equivalence criterion in relation to assessing the ability of structural materials to resist fatigue for a long time under the action of certain combinations of alternating and static loads. Keywords: regular loading cycle, extremely stressed state, static stressed state, bending, torsion, biaxial static tension. [email protected]

Comparative Analysis of Genetically-Modified Crops: Conditional Equivalence Criteria

The comparative assessment of genetically-modified (GM) crops relies on the principle of substantial equivalence, which states that such products should be compared to conventional counterparts that have an established history of safe use. In an effort to operationalize this principle, the GMO Panel of the European Food Safety Authority proposed an equivalence test that directly compares a GM test variety with a set of unrelated, conventionally-bred reference varieties with part of the difference as the known background of the test (the same as the given control). The criterion of the EFSA test, however, is defined solely by genotypic differences between the non-traited control and reference varieties (i.e. the background effect) while assuming the so-called GM trait effect as zero. As the outcome of an EFSA equivalence test is determined primarily by the similarity, or lack thereof, of the control and references, a conditional equivalence criterion is proposed in this investigation that focuses on “unintended” effects of a GM trait which is irrespective of the (random) genotypic value of a given control. The new criterion also includes a mean-scaled standard similar to the 80-125% rule for bioequivalence assessment practiced in the pharmaceutical industry as an alternative when the reference variation is zero or close to zero. In addition, optional criteria are proposed with a step-wise procedure to control the rate of false negatives (non-equivalence by chance) providing a comprehensive assessment under multiple comparisons. An application to maize grain composition data demonstrates that the conditional equivalence criterion provides effect-specific and more robust assessment of equivalence than the EFSA criterion did, especially for GM traits showing negligible or no unintended effects which are likely true for most traits in the current market.

On an integrability criterion for a family of cubic oscillators

<abstract><p>In this work we consider a family of cubic, with respect to the first derivative, nonlinear oscillators. We obtain the equivalence criterion for this family of equations and a non-canonical form of Ince Ⅶ equation, where as equivalence transformations we use generalized nonlocal transformations. As a result, we construct two integrable subfamilies of the considered family of equations. We also demonstrate that each member of these two subfamilies possesses an autonomous parametric first integral. Furthermore, we show that generalized nonlocal transformations preserve autonomous invariant curves for the equations from the studied family. As a consequence, we demonstrate that each member of these integrable subfamilies has two autonomous invariant curves, that correspond to irreducible polynomial invariant curves of the considered non-canonical form of Ince Ⅶ equation. We illustrate our results by two examples: An integrable cubic oscillator and a particular case of the Liénard (4, 9) equation.</p></abstract>

Probe Cocktail to Assess Transporter Function in Sandwich-Cultured Human Hepatocytes

PURPOSE: Probe substrates are used routinely to assess transporter function in vitro. Administration of multiple probe substrates together as a “cocktail” in sandwich-cultured human hepatocytes (SCHH) could increase the throughput of transporter function assessment in a physiologically-relevant in vitro system. This study was designed to compare transporter function between cocktail and single agent administration in SCHH. METHODS: Rosuvastatin, digoxin, and metformin were selected as probe substrates of hepatic transporters OATP1B1, OATP1B3, BCRP, P-gp, and OCT1. Total accumulation (Cells+Bile) and biliary excretion index (BEI) values derived from administration of the cocktail were compared to values obtained after administration of single agents in the absence and presence of a model inhibitor, erythromycin estolate. RESULTS: For rosuvastatin and metformin accumulation, the ratio of means [90% confidence interval (CI)] for cocktail to single agent administration was 100% [94%, 106%] and 90% [82%, 99%], respectively. Therefore, the cocktail and single-agent mode of administration were deemed equivalent per standard equivalence criterion of 80-120% for rosuvastatin and metformin accumulation, but not for digoxin accumulation (77% [62%, 92%]). The ratio of means [90% CI] for rosuvastatin BEI values between the two administration modes (105% [97%, 114%]) also was deemed equivalent. The ratio for digoxin BEI values between the two administration modes was 99% [78%, 120%]. In the presence of erythromycin estolate, the two administration modes were deemed equivalent for evaluation of rosuvastatin, digoxin, and metformin accumulation; the ratio of means [90% CI] was 104% [94%, 115%], 94% [82%, 105%], and 100% [88%, 111%], respectively. However, rosuvastatin and digoxin BEI values were low and quite variable in the presence of the inhibitor, so the BEI results were inconclusive. CONCLUSIONS: These data suggest that rosuvastatin and metformin can be administered as a cocktail to evaluate the function of OATP1B1, OATP1B3, BCRP, and OCT1 in SCHH, and that digoxin may not be an ideal component of such a cocktail.

An equivalence criterion for the generalized injectivity of modules with respect to algebraic classes of homomorphisms

Departing from a general definition of injectivity of modules with respect to suitable algebraic classes of morphisms, we establish conditions under which two modules are isomorphic when they are isomorphic to submodules of each other. The main result of this work extends both Bumby’s criterion for the isomorphism of injective modules and the well-known Cantor–Bernstein–Schröder’s theorem on the cardinality of sets. In the way, various properties on essential extensions, injective modules and injective hulls are generalized. The applicability of our main theorem embraces the cases of [Formula: see text]-injective and pure-injective modules as particular scenarios. Many of the propositions which lead to the proof of the main result of this paper are valid for arbitrary categories.

An Improved Dynamic Surface Control Approach and Applications to the Control of DC-DC Power Converter

This article presents an improved dynamic surface control (IDSC) approach for DC-DC Buck converter with parameter uncertainties and external disturbances. For IDSC method, the parameters update laws are designed based on uncertainty equivalence criterion, the requirements to the controlled systems are reduced, and the problem of explosion of complexity can be overcome. The features of the derived controller are discussed and illustrated by the Simulation study. The analysis and simulation show that the obtained controller possesses good adaptability and robustness to system uncertainties.