The implications of supplier encroachment via an online platform

E-commerce provides suppliers with the flexibility to operate an online arm via a platform in addition to their pre-existing physical stores. Although such supplier encroachment is becoming increasingly prevalent in e-commerce markets, the literature on supplier encroachment traditionally assumes that suppliers sell products to consumers directly and argues that supplier encroachment can mitigate double marginalisation problems that can secure Pareto improvements. This paper narrows this gap by investigating the implications of the supplier encroachment with an online platform under two scenarios (i.e., the platform owner forgoing or retaining its entry options). A central result obtained is that, unlike supplier-owned direct channels and in addition to the ‘win-win’ outcomes for the supplier and the traditional retailer, supplier encroachment with an online platform may also lead to ‘win-lose’ and ‘lose-lose’ outcomes. Furthermore, when the platform owner retains its entry option, such encroachment is always detrimental for the traditional retailer but beneficial for the supplier.

A Multiplication Technique for the Factorization of Bivariate Quaternionic Polynomials

We consider bivariate polynomials over the skew field of quaternions, where the indeterminates commute with all coefficients and with each other. We analyze existence of univariate factorizations, that is, factorizations with univariate linear factors. A necessary condition for existence of univariate factorizations is factorization of the norm polynomial into a product of univariate polynomials. This condition is, however, not sufficient. Our central result states that univariate factorizations exist after multiplication with a suitable univariate real polynomial as long as the necessary factorization condition is fulfilled. We present an algorithm for computing this real polynomial and a corresponding univariate factorization. If a univariate factorization of the original polynomial exists, a suitable input of the algorithm produces a constant multiplication factor, thus giving an a posteriori condition for existence of univariate factorizations. Some factorizations obtained in this way are of interest in mechanism science. We present an example of a curious closed-loop mechanism with eight revolute joints.

Energetic scaling in microbial growth

Microbial growth is a clear example of organization and structure arising in nonequilibrium conditions. Due to the complexity of the microbial metabolic network, elucidating the fundamental principles governing microbial growth remains a challenge. Here, we present a systematic analysis of microbial growth thermodynamics, leveraging an extensive dataset on energy-limited monoculture growth. A consistent thermodynamic framework based on reaction stoichiometry allows us to quantify how much of the available energy microbes can efficiently convert into new biomass while dissipating the remaining energy into the environment and producing entropy. We show that dissipation mechanisms can be linked to the electron donor uptake rate, a fact leading to the central result that the thermodynamic efficiency is related to the electron donor uptake rate by the scaling law η∝μED−1/2 and to the growth yield by η∝Y4/5. These findings allow us to rederive the Pirt equation from a thermodynamic perspective, providing a means to compute its coefficients, as well as a deeper understanding of the relationship between growth rate and yield. Our results provide rather general insights into the relation between mass and energy conversion in microbial growth with potentially wide application, especially in ecology and biotechnology.

ON THE DECIDABILITY OF THE INTERSECTION OF ALL TABULAR P N L-LOGICS

В (Попов 2018) проводилось исследование счетно-бесконечной иерархии табличных P N L-логик - логик P N L[3], P N L[4], P N L[5] и т. д. Центральный результат предлагаемой статьи: ∩i∈N P N L[i + 2] является разрешимой паранормальной логикой. In previous work (Попов 2018), we studied one countably infinite hierarchy of tabular P N L-logics (that is, P N L[3], P N L[4], P N L[5] and so on). The central result of the present article: ∩i∈N P N L[i + 2] is a decidable paranormal logic.

Narrative identity among people with disabilities during the COVID-19 pandemic: The interdependent self

This study examines narrative identity among a large, diverse (American) sample of people with disabilities (PWDs) during the “second wave” of the COVID-19 pandemic (October-December, 2020). The study relied on abductive analyses, combining a purely inductive phase of inquiry followed by two rounds of investigation that filtered inductive insights through three theoretical lenses: social-ecological theory, the theory of narrative identity, and perspectives from the interdisciplinary field of disability studies. The central result was the identification of a particular configuration of self, one that was demonstrably interdependent with both immediate interpersonal contexts and with broader cultural contexts. This interdependent self was interpreted in both positive and negative ways by PWDs. These findings invite future inquiry into commonplace conceptualizations of an independent self at the center of personality research.

Performability of Actions

Action theory may be regarded as a theoretical foundation of AI, because it provides in a logically coherent way the principles of performing actions by agents. But, more importantly, action theory offers a formal ontology mainly based on set-theoretic constructs. This ontology isolates various types of actions as structured entities: atomic, sequential, compound, ordered, situational actions etc., and it is a solid and non-removable foundation of any rational activity. The paper is mainly concerned with a bunch of issues centered around the notion of performability of actions. It seems that the problem of performability of actions, though of basic importance for purely practical applications, has not been investigated in the literature in a systematic way thus far. This work, being a companion to the book as reported (Czelakowski in Freedom and enforcement in action. Elements of formal action theory, Springer 2015), elaborates the theory of performability of actions based on relational models and formal constructs borrowed from formal lingusistics. The discussion of performability of actions is encapsulated in the form of a strict logical system "Equation missing". This system is semantically defined in terms of its intended models in which the role of actions of various types (atomic, sequential and compound ones) is accentuated. Since due to the nature of compound actions the system "Equation missing" is not finitary, other semantic variants of "Equation missing" are defined. The focus in on the system "Equation missing" of performability of finite compound actions. An adequate axiom system for "Equation missing" is defined. The strong completeness theorem is the central result. The role of the canonical model in the proof of the completeness theorem is highlighted. The relationship between performability of actions and dynamic logic is also discussed.

The Measure Aspect of Quantum Uncertainty, of Entanglement, and the Associated Entropies

Indeterminacy associated with the probing of a quantum state is commonly expressed through spectral distances (metric) featured in the outcomes of repeated experiments. Here, we express it as an effective amount (measure) of distinct outcomes instead. The resulting μ-uncertainties are described by the effective number theory whose central result, the existence of a minimal amount, leads to a well-defined notion of intrinsic irremovable uncertainty. We derive μ-uncertainty formulas for arbitrary set of commuting operators, including the cases with continuous spectra. The associated entropy-like characteristics, the μ-entropies, convey how many degrees of freedom are effectively involved in a given measurement process. In order to construct quantum μ-entropies, we are led to quantum effective numbers designed to count independent, mutually orthogonal states effectively comprising a density matrix. This concept is basis-independent and leads to a measure-based characterization of entanglement.

Context for the Disc Embedding Theorem

‘Context for the Disc Embedding Theorem’ explains why the theorem is the central result in the study of topological 4-manifolds. After recalling surgery theory and the proof of the s-cobordism theorem for high-dimensional manifolds, the chapter explains what goes wrong when trying to apply the same techniques in four dimensions and how to start overcoming these problems. The complete statement of the disc embedding theorem is provided. Finally the most important consequences to manifold theory are listed, including a proof of why Alexander polynomial one knots are topologically slice and the existence of exotic smooth structures on 4-dimensional Euclidean space.

Proper static potential in classical lattice gauge theory at finite T

We compute the proper real-time interaction potential between a static quark and antiquark in classical lattice gauge theory at finite temperature. Our central result is the determination of the screened real-part of this potential, and we reconfirm the presence of an imaginary part. The real part is intimately related to the back-reaction of the static sources onto the gauge fields, incorporated via Gauss’s law. Differences in the treatment of static sources in quantum and classical lattice gauge theory are discussed.

Mentoringprozesse in der Lehrer:innenausbildung. Gelingensbedingungen für Schulpraktika

School mentoring in Austria is structurally anchored in the curricula of the new teacher trai-ning with the establishment/implementation of pedagogical-practical studies. Partner schools of universities of teacher education and universities offer students space for learning experience through practice and opportunity to complete the curricular parts of school in social environ-ment of schools. Mentors accompany and support the professionalization process and enter into a mutual learning and developmental relationship against the background of curricular re-quirement structures as well as subjective interpretative patterns. Transformational mentoring with a categorical breakdown to guide self-reflection is presented and discussed as a possible form of mentoring.In the research approach, interviews with mentors and students were conducted and evaluated with Grounded Theory. The central result of the study is that those involved in the dyadic rela-tionship want to build up or want to enter into a profession-specific learning and development process with the aim of furthering their own effectiveness and professionalism. Emanating from these studies, (training ) models for mentoring programs were constructed.