Example Of Asymmetry Research Articles

Symmetry and asymmetry between positive and negative square energies of graphs

The positive and negative square energies of a graph, $s^+(G)$ and $s^-(G)$, are the sums of squares of the positive and negative eigenvalues of the adjacency matrix, respectively. The first results on square energies revealed symmetry between $s^+(G)$ and $s^-(G)$. This paper reviews examples of asymmetry between these parameters, for example using large random graphs and the ratios $s^+/s^-$ and $s^-/s^+$, as well as new examples of symmetry. Some questions previously asked about $s^{+}$ and $s^{-}$ are answered and several further avenues of research are suggested.

A General Approach to Sylvester-Polynomial-Conjugate Matrix Equations

Sylvester-polynomial-conjugate matrix equations unify many well-known versions and generalizations of the Sylvester matrix equation AX−XB=C which have a wide range of applications. In this paper, we present a general approach to Sylvester-polynomial-conjugate matrix equations via groupoids, vector spaces, and matrices over skew polynomial rings. The obtained results are applied to Sylvester-polynomial-conjugate matrix equations over complex numbers and quaternions. The main role in our approach is played by skew polynomial rings, which are well-known tools in algebra to provide examples of asymmetry between left-sided and right-sided versions of many ring objects.

The Problem of Asymmetric Development of the Global Financial Market

The transformation of the modern global monetary and financial system involves the elimination of institutional and functional contradictions existing at various levels. Some contradictions arose as a result of the asymmetric development of the global financial market (GFM). The aim of the article is to substantiate the asymmetry of the GFM development as an organic phenomenon, which, on the one hand, becomes a serious obstacle to the functioning and progressive development of the world economy, and, on the other hand, is the driving force behind this development. The authors apply general logical, theoretical, empirical, and special research methods. The origins of the asymmetric development of the GFM are determined. Endogenous and exogenous factors of GFM asymmetry were revealed. The article considers examples of asymmetry in various GFM segments. The negative impact of the global financial and economic crisis of 2008–2009 and the coronavirus pandemic on increasing the asymmetry of the GFM development has been determined. Based on the analysis of the key macroeconomic indicators of the top 20 countries in terms of GDP, the asymmetric nature and the absence of stable patterns that determine the country’s position in the world ranking are revealed. The authors conclude that the asymmetry of the GFM development is an organic phenomenon, caused by a wide range of causes of endogenous and exogenous nature. Endogenous asymmetries can be partially compensated either through complete economic isolation, which is likely to lead to a slowdown in development and lagging behind other countries in the future or through active involvement in a system of world economic relations based on fair partnerships. Exogenous asymmetry, due to the peculiarities of the historically established world order, is destructive for all participants in the global economic system, including those whose interests must be protected in the first place.

Extreme developmental instability associated with wing plasticity in pea aphids.

A key focus of evolutionary developmental biology is on how phenotypic diversity is generated. In particular, both plasticity and developmental instability contribute to phenotypic variation among genetically identical individuals, but the interactions between the two phenomena and their general fitness impacts are unclear. We discovered a striking example of asymmetry in pea aphids: the presence of wings on one side and the complete or partial absence of wings on the opposite side. We used this asymmetric phenotype to study the connection between plasticity, developmental instability and fitness. We found that this asymmetric wing development (i) occurred equally on both sides and thus is a developmental instability; (ii) is present in some genetically unique lines but not others, and thus has a genetic basis; and (iii) has intermediate levels of fecundity, and thus does not necessarily have negative fitness consequences. We conclude that this dramatic asymmetry may arise from incomplete switching between developmental targets, linking plasticity and developmental instability. We suspect that what we have observed may be a more widespread phenomenon, occurring across species that routinely produce distinct, alternative phenotypes.

Asymmetric Impact of Advertising revenues on Consumer Behavior: A Bivariate Approach

There is very little research in the extant literature on the asymmetry that may exist in consumers reactions to changes in the aggregate level of advertising in the marketplace. Aggregate levels of advertising act as a signal to consumers regarding the health of the economy. In this study, we investigate the extent of this asymmetry in terms of how consumer confidence, which is a proxy for future consumer spending, responds to upturns and downturns in advertising revenues. We find that consumers react with higher levels of confidence to upturns in advertising revenues. However, consumers do not react to downturns in advertising revenue with commensurate reductions in consumer confidence. They ignore the signaling effects of a downturn in advertising revenues, displaying asymmetric behavior in response to changes in advertising revenue. The increase in consumer confidence resulting from an increase in advertising revenue is a delayed response effect and comes after two quarters lag. It is statistically significant at conventional levels for the following two quarters as a response to a one-time upturn in advertising revenues. The results provide important information to practitioners and researchers on the asymmetric signaling and ratchet effects of advertising on consumer behavior. The implication for practitioners and policy makers is that aggregate increases in advertising has a delayed positive effect on consumer confidence with positive implications for consumer spending. The implications for researchers is another example of asymmetry in human decision-making and specifically the tendency to embrace positive and ignore negative economic signals. The implication for investors is a better understanding of how macro advertising expenditures function as a leading indicator for consumer confidence, consumer spending, and economic growth.

Computationally Universal Phase of Quantum Matter.

We provide the first example of a symmetry protected quantum phase that has universal computational power. This two-dimensional phase is protected by one-dimensional linelike symmetries that can be understood in terms of the local symmetries of a tensor network. These local symmetries imply that every ground state in the phase is a universal resource for measurement-based quantum computation.

Is an Appreciation of Isomerism the Key to Unlocking the Mysteries of the Cardiac Findings in Heterotaxy?

Pediatric cardiologists treating patients with severe congenital cardiac defects define “visceral heterotaxy” on the basis of isomerism of the atrial appendages. The isomeric features represent an obvious manifestation of disruption of left-right asymmetry during embryonic development. Thus, there are two subsets of individuals within the overall syndrome, with features of either right or left isomerism. Within the heart, it is only the atrial appendages that are truly isomeric. The remainder of the cardiac components shows variable morphology, as does the arrangement of the remaining body organs. Order is provided in this potentially chaotic arrangement simply by describing the specific features of each of the systems. These features as defined by clinicians, however, seem less well recognized by those investigating the developmental origins of the disruption of symmetry. Developmental biologists place much greater emphasis on ventricular looping. Although the direction of the loop can certainly be interpreted as representing an example of asymmetry, it is not comparable to the isomeric features that underscore the clinical syndromes. This is because, thus far, there is no evidence of ventricular isomerism, with the ventricles distinguished one from the other on the basis of their disparate anatomical features. In similar fashion, some consider transposition to represent abnormal lateralization, but again, clinical diagnosis depends on recognition of the lateralized features. In this review, therefore, we discuss the key questions that currently underscore the mismatch in the approaches to “lateralization” as taken by clinicians and developmental biologists.

Take your seats: leftward asymmetry in classroom seating choice.

Despite an overall body symmetry, human behavior is full of examples of asymmetry, from writing or gesturing to kissing and cradling. Prior research has revealed that theatre patrons show a bias towards sitting on the right side of a movie theatre. Two competing theories have attempted to explain this seating asymmetry: one posits that expectation of processing demand drives the bias; the other posits that basic motor asymmetries drive the bias. To test these theories we assessed the real-world classroom seating choices of university students using photographs. A bias for students to choose seats on the left side of the classroom was observed, in contrast to the right side bias observed in theatre seating studies. These results provide evidence in support of a processing-expectation bias.

Asymmetric reproductive isolation during simultaneous reciprocal mating in pulmonates

The generality of asymmetric reproductive isolation between reciprocal crosses suggests that the evolution of isolation mechanisms often proceeds in reciprocal asymmetry. In hermaphroditic snails that copulate simultaneously and reciprocally, asymmetry in premating isolation may not be readily detectable because the failure of the symmetric performance of courtship would prevent copulation from occurring. On the other hand, through their prolonged copulation, snails discriminate among mates when exchanging spermatophores for their benefit and thus may exhibit asymmetric reproductive isolation during interspecific mating. However, no clear case of reciprocal asymmetry has been found in reproductive isolation between snail species. Here we show a discrete difference in hybridization success between simultaneous reciprocal copulations between two species of pulmonate snails. Premating isolation of Bradybaena pellucida (BP) and Bradybaena similaris (BS) is incomplete in captivity. In interspecific copulation, BP removes its penis without transferring a spermatophore, while BS sires hybrids by inseminating BP. Thus, 'male' BP or 'female' BS rejects the other individual, while female BP and male BS accept each other, so that the two sexes of either BP or BS oppose each other in mate discrimination. Our results are a clear example of asymmetry in reproductive isolation during simultaneous reciprocal mating between hermaphroditic animals.

Genomic imprinting and the social brain.

Genomic imprinting refers to the parent-of-origin-specific epigenetic marking of a number of genes. This epigenetic mark leads to a bias in expression between maternally and paternally inherited imprinted genes, that in some cases results in monoallelic expression from one parental allele. Genomic imprinting is often thought to have evolved as a consequence of the intragenomic conflict between the parental alleles that occurs whenever there is an asymmetry of relatedness. The two main examples of asymmetry of relatedness are when there is partiality of parental investment in offspring (as is the case for placental mammals, where there is also the possibility of extended postnatal care by one parent), and in social groups where there is a sex-biased dispersal. From this evolutionary starting point, it is predicted that, at the behavioural level, imprinted genes will influence what can broadly be termed bonding and social behaviour. We examine the animal and human literature for examples of imprinted genes mediating these behaviours, and divide them into two general classes. Firstly, mother-offspring interactions (suckling, attachment and maternal behaviours) that are predicted to occur when partiality in parental investment in early postnatal offspring occurs; and secondly, adult social interactions, when there is an asymmetry of relatedness in social groups. Finally, we return to the evolutionary theory and examine whether there is a pattern of behavioural functions mediated by imprinted genes emerging from the limited data, and also whether any tangible predictions can be made with regards to the direction of action of genes of maternal or paternal origin.

Asymmetrical spondylolysis.

The objective of this study was to examine examples of spondylolysis in which the pattern of separation was clearly asymmetrical, in order to learn more about the process of bone separation that produces this condition. Although the primary focus was on unilateral complete separation, examples of asymmetry represented by incomplete separation and by complete bilateral separation where the separation sites are in different locations on the two sides were included. Two collections were used, one consisting of Canadian Inuit skeletons curated at the Canadian Museum of Civilization, and the other of 48 individual examples of asymmetrical spondylolysis from sites in a variety of localities curated by several different institutions. The first collection was studied primarily to observe early manifestations of spondylolysis, particularly incomplete separation, while various patterns of asymmetrical complete separation were the focus of the second. The results indicate that asymmetry is part of the earliest osteological picture of spondylolysis, with right-sidedness predominating, a condition perhaps related in some way to handedness. The right-side predominance appears to decrease with age. The ratio of unilateral to bilateral separation ranges from 3-33% in different studies, and a significant number of the unilateral separations have spina bifida occurring in the same vertebra. Overall, the specimens examined here, considered along with clinical cases, nicely illustrate a progression of spondylolysis. A unilateral separation may heal, it may progress to bilateral separation, or it may remain as a permanent condition, producing a pattern of degenerative changes that can include spondylolisthesis. A unilateral healing of bilateral complete separation is likely a rare phenomenon, at least after the separations have reached a certain level of maturity.

Broken symmetry

Broken symmetry

An example of asymmetry of convolution operators

Esistono un gruppo compatto non commutativoG∼ ed un operatore di convoluzioneT tale che: perp∈[2,4] e perq∈[1,2),T∈Lpp(G∼) eT∋Lqq(G∼).

CONGENITAL HEMIHYPERTROPHY

IT IS not uncommon in pediatric practice to see examples of asymmetry involving parts of the face or even, at times, of the extremities. However, when this asymmetry affects a complete side and is found in the bone structure as well as in the soft tissues it is rare enough to report. The number of such cases described in the literature to date is still probably under the one hundred mark. These cases, described as instances of total (or complete) asymmetry, may be of the atrophic or hypertrophic type. The nature and especially the causation of this condition have never been satisfactorily explained, and this is so in no small measure because of the lack of autopsied material. In an article published in 1942, Schwartzman and others 1 stated that only 4 cases have come to postmortem examination. In the case we are about to report we were able to