Modular Theory Research Articles

Strong nutrient-plant interactions enhance the stability of ecosystems

Modular food web theory shows how weak energetic fluxes resulting from consumptive interactions plays a major role in stabilizing food webs in space and time. Despite the reliance on energetic fluxes, food web theory surprisingly remains poorly understood within an ecosystem context that naturally focuses on material fluxes. At the same time, while ecosystem theory has employed modular nutrient-limited ecosystem models to understand how limiting nutrients alter the structure and dynamics of food webs, ecosystem theory has overlooked the role of key ecosystem interactions and their strengths (e.g., plant-nutrient; R-N) in mediating the stability of nutrient-limited ecosystems. Here, towards integrating food web theory and ecosystem theory, we first briefly review consumer-resource interactions (C-R) highlighting the relationship between the structure of C-R interactions and the stability of food web modules. We then translate this framework to nutrient-based systems, showing that the nutrient-plant interaction behaves as a coherent extension of current modular food web theory; however, in contrast to the rule that weak C-R interactions tend to be stabilizing we show that strong nutrient-plant interactions are potent stabilizers in nutrient-limited ecosystem models.

Electron EDM arising from modulus \u03c4 in the supersymmetric modular invariant flavor models

The electric dipole moment (EDM) of electron is studied in the supersymmetric A4 modular invariant theory of flavors with CP invariance. The CP symmetry of the lepton sector is broken by fixing the modulus τ. Lepton mass matrices are completely consistent with observed lepton masses and mixing angles in our model. In this framework, a fixed τ also causes the CP violation in the soft SUSY breaking terms. The electron EDM arises from the CP non-conserved soft SUSY breaking terms. The experimental upper bound of the electron EDM excludes the SUSY mass scale below 4–6 TeV depending on five cases of the lepton mass matrices. In order to see the effect of CP phase of the modulus τ, we examine the correlation between the electron EDM and the decay rate of the μ → eγ decay, which is also predicted by the soft SUSY breaking terms. The correlations are clearly predicted in contrast to models of the conventional flavor symmetry. The branching ratio is approximately proportional to the square of |de/e|. The SUSY mass scale will be constrained by the future sensitivity of the electron EDM, |de/e| ≃ 10−30 cm. Indeed, it could probe the SUSY mass range of 10–20 TeV in our model. Thus, the electron EDM provides a severe test of the CP violation via the modulus τ in the supersymmetric modular invariant theory of flavors.

Modular symmetry at level 6 and a new route towards finite modular groups

We propose to construct the finite modular groups from the quotient of two principal congruence subgroups as Γ(N′)/Γ(N″), and the modular group SL(2, ℤ) is ex- tended to a principal congruence subgroup Γ(N′). The original modular invariant theory is reproduced when N′ = 1. We perform a comprehensive study of {Gamma}_6^{prime } modular symmetry corresponding to N′ = 1 and N″ = 6, five types of models for lepton masses and mixing with {Gamma}_6^{prime } modular symmetry are discussed and some example models are studied numerically. The case of N′ = 2 and N″ = 6 is considered, the finite modular group is Γ(2)/Γ(6) ≅ T′, and a benchmark model is constructed.

Crystal of affine type [formula omitted] and Hecke algebras at a primitive 2ℓth root of unity

Let ℓ∈N with ℓ>1. In this paper we give a new realization of the crystal of affine type Aˆℓ−1 using the modular representation theory of the affine Hecke algebras Hn of type A and their level two cyclotomic quotients with Hecke parameter being a primitive 2ℓth root of unity. We construct “hat” versions of i-induction and i-restriction functors on the category RepI(Hn) of finite dimensional integral modules over Hn, which induce Kashiwara operators on a suitable subgroup of the Grothendieck groups of RepI(Hn). For any simple module M∈RepI(Hn), we prove that the simple submodules of resHn−2HnM which belong to Bˆ(∞) (Definition 5.1) occur with multiplicity two. The main results generalize the earlier work of Grojnowski and Vazirani on the relations between the crystal of slˆℓ and the affine Hecke algebras of type A at a primitive ℓth root of unity.

The Effect of Role-Based Product Representations on Individual and Team Coordination Practices: A Field Study of a Globally Distributed New Product Development Team

The investigation of the appealing indication that a modular product architecture is best associated to a loosely coupled organizational structure—that is, the mirroring hypothesis—has produced contradictory evidence, especially in the dynamic and ambiguous context of new product development. By integrating modularity theory and product-representation theories, we investigate how individual agency affects coordination in teams developing modular products. We conducted a field study of Flower-Net, a globally distributed team in a major IT company, engaged with the development of a modular software using agile practices. Our grounded model shows that, whereas top managers defined the product as modular and coordinated work accordingly, individuals developed different representations of the product’s architecture and conflicting individual coordination practices. We traced the individual development of product architecture representations back to the individual interpretations of organizational roles as more or less “segmented.” Conflicting individual practices, associated to different role-based product representations, were not addressed by the team—that developed a state of illusory concordance—and impaired the functioning of the team. This study contributes to the literature on modularity and the mirroring hypothesis by proposing individual role-based representations as an underexplored level of analysis for the matching between product and organizational modularity (Mirroring Hypothesis II). It also contributes to the debate on how representations affect team coordination, by detailing how role-based product representations can influence team members’ divergence and sustain illusory concordance.

A survey of semisimple algebras in algebraic combinatorics

This is a survey of semisimple algebras of current interest in algebraic combinatorics, with a focus on questions which we feel will be new and interesting to experts in group algebras, integral representation theory, and computational algebra. The algebras arise primarily in two families: coherent algebras and subconstituent (aka. Terwilliger) algebras. Coherent algebras are subalgebras of full matrix algebras having a basis of 01-matrices satisfying the conditions that it be transpose-closed, sum to the all 1’s matrix, and contain a subset \(\Delta \) that sums to the identity matrix. The special case when \(\Delta \) is a singleton is the important case of an adjacency algebra of a finite association scheme. A Terwilliger algebra is a semisimple extension of a coherent algebra by a set of diagonal 01-matrices determined canonically from its basis elements and a choice of row. We will survey the current state of knowledge of the complex, real, rational, modular, and integral representation theory of these semisimple algebras, indicate their connections with other areas of mathematics, and present several open questions.

Interfaces, Modularity and Ecosystem Emergence: How DARPA Modularized the Semiconductor Ecosystem

Scholars have identified the pivotal role that modularity plays in creating innovation ecosystems—complex arrangements of buyers, suppliers, and complementors. In large part, this is due to modularity’s effect on industry structure, breaking up the value chain along interfaces, thus allowing specialized firms to enter, compete, and innovate. Less well-understood is where modularity comes from. While modularity theory is heavily influenced by the information technology sector, other industries (such as automobiles) suggest a potential conflict between firm incentives and the creation of modular interfaces. We demonstrate the role for government funding in generating modularity using an historical case study of the semiconductor industry and shifts in industry structure enabled by public R&D funding in the 1970s. We argue that this funding was mission-oriented with an interest in changing the semiconductor industry structure from a vertically-integrated oligopoly to a competitive, de-integrated industry. A subsequent shift, to an ecosystem encompassing an ever-expanding variety of customer industries, further increases the long-term economic value of modularity-as-policy.

A modular design method based on TRIZ and AD and its application to cutter changing robot

Modular design, Axiomatic design (AD) and Theory of inventive problem solving (TRIZ) have been increasingly popularized in concept design of modern mechanical product. Each method has their own advantages and drawbacks. The benefit of modular design is reducing the product design period, and AD has the capability of problem analysis, while TRIZ’s expertise is innovative idea generation. According to the complementarity of these three approaches, an innovative and systematic methodology is proposed to design big complex mechanical system. Firstly, the module partition is executed based on scenario decomposition. Then, the behavior attributes of modules are listed to find the design contradiction, including motion form, spatial constraints, and performance requirements. TRIZ tools are employed to deal with the contradictions between behavior attributes. The decomposition and mapping of functional requirements and design parameters are carried out to construct the structural hierarchy of each module. Then, modules are integrated considering the connections between each other. Finally, the operation steps in application scenario are designed in temporal and spatial dimensions. Design of cutter changing robot for shield tunneling machine is taken as an example to validate the feasibility and effectiveness of the proposed method.

Acquisition of variability in Akan Phonology: Labio-palatalized consonants and front rounded vowels.

This paper addresses how input variability in the adult phonological system is mastered in the output of young children in Akan, a Kwa language spoken in Ghana, involving variability between labio-palatalized consonants and front rounded vowels. The high-frequency variant involves a complex consonant which is expected to be mastered late, while the low-frequency variant involves a front rounded vowel which is expected to be mastered relatively early. Late mastery of complex consonants was confirmed. The high-frequency labiopalatalized-consonant variant was absent at age 3 and not yet mastered even at age 5. All children produced the easier-to-produce low-frequency front-rounded-vowel variant, most at far greater frequency than in adult speech, implying that a child's output limitations can affect which variant the child targets for production. Modular theories, in which phonological plans reflect only the characteristics of adult input, fail to account for our results. Non-modular theories are implicated.

Boundary negotiations: a paradox theoretical approach for efficient and flexible modular systems

PurposeThe purpose of this paper is to explore the interplay between firm boundary decisions and the management of both efficiency and flexibility and the implications this has for modular design in the provision of advanced services.Design/methodology/approachA single case study in the defence industry employs semi-structured interviews supplemented by secondary data. Data are analysed using thematic analysis.FindingsThe findings provide a process model of boundary negotiations for the design of efficient and flexible modular systems consisting of three phases; boundary ambiguity, boundary defences and boundary alignment.Practical implicationsThe study provides a process framework for boundary negotiations to help organisations navigate the management of both-and efficiency and flexibility in the provision of advanced services.Originality/valueDrawing upon modularity, paradox and systems theory, this article provides novel theoretical insight into the relationship between firm boundary decisions and the management of both-and efficiency vs. flexibility in the provision of product upgrade services.

Computing homological residue fields in algebra and topology

We determine the homological residue fields, in the sense of tensor-triangular geometry, in a series of concrete examples ranging from topological stable homotopy theory to modular representation theory of finite groups.

Modular invariant dynamics and fermion mass hierarchies around \u03c4 = i

We discuss fermion mass hierarchies within modular invariant flavour models. We analyse the neighbourhood of the self-dual point τ = i, where modular invariant theories possess a residual Z4 invariance. In this region the breaking of Z4 can be fully described by the spurion ϵ ≈ τ − i, that flips its sign under Z4. Degeneracies or vanishing eigenvalues of fermion mass matrices, forced by the Z4 symmetry at τ = i, are removed by slightly deviating from the self-dual point. Relevant mass ratios are controlled by powers of |ϵ|. We present examples where this mechanism is a key ingredient to successfully implement an hierarchical spectrum in the lepton sector, even in the presence of a non-minimal Kähler potential.

Modeling genome-wide by environment interactions through omnigenic interactome networks.

How genes interact with the environment to shape phenotypic variation and evolution is a fundamental question intriguing to biologists from various fields. Existing linear models built on single genes are inadequate to reveal the complexity of genotype-environment (G-E) interactions. Here, we develop a conceptual model for mechanistically dissecting G-E interplay by integrating previously disconnected theories and methods. Under this integration, evolutionary game theory, developmental modularity theory, and a variable selection method allow us to reconstruct environment-induced, maximally informative, sparse, and casual multilayer genetic networks. We design and conduct two mapping experiments by using a desert-adapted tree species to validate the biological application of the model proposed. The model identifies previously uncharacterized molecular mechanisms that mediate trees' response to saline stress. Our model provides a tool to comprehend the genetic architecture of trait variation and evolution and trace the information flow of each gene toward phenotypes within omnigenic networks.

Statistics on the Industry Structure of the Russian Economy and its Optimization Model

This article describes the results of econometric research and optimization of the industry structure of the Russian economy. The results of modern domestic research on this topic show that the task of establishing theoretically justified quantitative criteria for optimizing the structural composition of multicomponent (discrete) social systems remains beyond due attention and not only should, but can be solved. Therefore, the purpose of this study is to determine the optimal size, to establish a measure of a harmonious combination of the sectoral components of the domestic economy and, on their basis, to develop an actual orientation of the structural economic policy of the Russian state for the foreseeable future.Materials and methods. The theoretical foundations of the study are developed on the basis of the authors’ preferences regarding the results of conceptual and applied developments of domestic scientists in the field of structural analysis of systems. The methodological basis of the research consists of works on the structural organization of systems, the concept of structural harmony of systems, the dialectic of harmony, the modular theory of society, and econometrics. The analysis of parameters (indicators) of the component composition of the domestic economy was carried out on the basis of statistical data of ROSSTAT for 2018. The assessment of the export-import potential of the domestic economy is based on statistical data on the cost of output of goods and services for 2014-2018. Econometric methods of processing the initial data and tabular methods of visualizing the results of the study were used. Standard Microsoft Office application software packages were used to solve the research tasks.Results. The theoretical foundations, the procedure and algorithms for studying the structure of multicomponent (discrete) systems are presented. The criterion (maximizing the structural potential of the development of the system under study) is determined and a quantitative model for optimizing their structure is constructed. On the basis of the model, the optimal scales of the structural components (branches) of the domestic economy are determined. According to the statistics for 2018, reflecting the resource capacity (employment, fixed assets, number of organizations) and the results of activities (value added, investment activity), econometric calculations of the relative (in comparison with the entire economy) sizes of the Russian economy sectors were made. Comparison of actual and model (optimal) indicators of the magnitude of domestic industries as a way to detect non-optimality (the discrepancies) of its structure, shows the path of transition from its actual status to “the best” structure which describes a quantitative model of optimal combination of scale of its industries.Conclusion. Based on the quantitative model of optimization of the industry structure, the unbalanced nature of the industry structure, the need for harmonization of the industry composition and, thus, the presence of structural reserves for economic growth of the Russian economy are shown. Optimization of the scale of industries is the formation of structural conditions for a more efficient functioning of the Russian economy; it can be recognized as a macroeconomic condition and a strategic reserve for the economic growth.

Mini-Workshop: Kronecker, Plethysm, and Sylow Branching Coefficients and their Applications to Complexity Theory

The Kronecker, plethysm and Sylow branching coefficients describe the decomposition of representations of symmetric groups obtained by tensor products and induction. Understanding these decompositions has been hailed as one of the definitive open problems in algebraic combinatorics and has profound and deep connections with representation theory, symplectic geometry, complexity theory, quantum information theory, and local-global conjectures in representation theory of finite groups. The overarching theme of the Mini-Workshop has been the use of hidden, richer representation theoretic structures to prove and disprove conjectures concerning these coefficients. These structures arise from the modular and local-global representation theory of symmetric groups, graded representation theory of Hecke and Cherednik algebras, and categorical Lie theory.

Frugivore zoogeochemistry in tropical forest ecosystems

Frugivore zoogeochemistry in tropical forest ecosystems

Modeling Genome-Wide by Environment Interactions Through Omnigenic Interactome Networks

How genes interact with the environment to shape phenotypic variation and evolution is a fundamental question interesting to biologists from various fields. Existing linear models built on single genes are inadequate to reveal the complexity of gene-environment (G-E) interactions. Here, we develop a conceptual model for mechanistically dissecting G-E interplay by integrating previously disconnected theories and methods. Under this integration, evolutionary game theory, developmental modularity theory, and variable selection method allow us to reconstruct environment-induced, maximally informative, sparse, and casual multilayer genetic networks. We design and conduct a mapping experiment using a salt-resistant tree species to validate the biological application of the new model. The model identifies previously uncharacterized molecular mechanisms that mediate trees’ response to saline stress. Our model provides a tool to comprehend the genetic architecture of trait variation and evolution and trace the information flow of each gene toward phenotypes within omnigenic networks.

Red ear syndrome in children: Review of literature and report of three cases

BackgroundRed ear syndrome (RES) is a neurological syndrome that is characterized by attacks of redness and pain that is localized in the earlobe, accompanied by a burning sensation, swelling or otalgia. The exact pathophysiology of RES is not known. Several pediatric cases have been described. They show an extreme variability in clinical presentation and therapeutic response, and therefore there are numerous difficulties in the diagnostic-therapeutic approach and in the comprehension of the physiopathology. The goal of this report is to present three clinical cases of red ear syndrome in children. These cases show various characteristics that can give useful indications regarding the differential diagnosis and the pathogenetic mechanisms that are involved, particularly when they are compared with cases published in the literature. Case-reportsWe report three pediatric RES cases: 1) a boy whose condition offered a typical example of the association that occurs between migraine and RES. 2) a girl with idiopathic RES. 3) a child who suffered RES attacks that showed many similarities with trigeminal autonomic cephalalgias. ConclusionOur clinical series shows the different ways in which RES can be expressed and they support the reported scientific literature. We suggest that the different forms of RES have a common final autonomic pathogenetic mechanism that is activated by parasympathetic hyperactivity and sympathetic inhibition. The different temporal characteristics, frequency, etc. may depend on the activation of distinct physiopathological modules that are related to the pain circuits, as suggested by the modular theory which describes that groups of neurons are defined as a module, where each module is responsible for a symptom and the individual's headache is defined by the activated modules.

Module partitioning study of specialized engineering services based on modular theory ——case on coal production firms

Outsourcing of specialized engineering services has become one of the routes to the innovation and high-quality development of the commercial model of coal production enterprises in China. Currently, although there is practice, no scale-up development has been achieved.In this paper, based on modular theory, under the condition of unknown expert weights, triangular fuzzy number method is used to construct a service unit association relationship evaluation model, and the correlation matrix is calculated. Then, a genetic algorithm is used to cluster the association matrix and obtain the results of the division of the outsourced module of engineering services. Finally, the proposed method is validated using the coal mine development process of coal producers as an example.

Did George Orwell’s Newspeak Have a Point?: Linguistic Relativity and Its Implications for Copyright

To date, copyright scholarship has almost completely overlooked the linguistics and cognitive psychology literature exploring the connection between language and thought. An exploration of the two major strains of this literature, known as universal grammar (associated with Noam Chomsky) and linguistic relativity (centered around the Sapir-Whorf hypothesis), offers insights into the copyrightability of constructed languages and of the type of software packages at issue in Google v. Oracle recently decided by the Supreme Court. It turns to modularity theory as the key idea unifying the analysis of both languages and software in ways that suggest that the information filtering associated with the Sapir-Whorf hypothesis may be a general strategy for managing complex systems that is not restricted to language. It also examines Jerry Fodor’s application of modularity theory to cognition and his Language of Thought Hypothesis to see what they reveal about the idea-expression dichotomy.