Behavioral Asymmetries Research Articles

Cross-Layer Optimization for Multilevel Cell STT-RAM Caches

Spin-transfer torque random access memory (STT-RAM), as an emerging nonvolatile memory technology, provides very dense array structure and extremely low leakage power consumption. It demonstrates a great potential in replacing conventional static random access memory technology to develop the next-generation on-chip cache memory of microprocessors and graphics processing units. The multilevel cell (MLC) design of STT-RAM that stores two or more bits in one cell potentially has higher storage capacity and faster system performance, attracting significant attention. In this paper, we first quantitatively evaluated the data storage density of the MLC STT-RAM. Our results revealed limited density improvement because of the large size of access transistor induced by high write current amplitude requirement and asymmetry of switching behavior. Moreover, the read and write accesses of existing MLC STT-RAM cache designs require two-step operation. The system level evaluation shows that the long access latency could amortize the performance speed brought by larger cache size, and even degrade the system performance for some applications. To unleash the potential of MLC STT-RAM cache, we proposed a new design through a cross-layer co-optimization. The memory cell structure integrated the reversed stacking of magnetic junction tunneling for a more balanced device and design tradeoff. In architecture development, we presented an adaptive mode switching mechanism: based on application’s memory access behavior, the MLC STT-RAM cache can dynamically change between low latency single-level cell mode and high capacity MLC mode. Furthermore, we divided cache lines into fast and slow regions and investigated new data migration policies to allocate frequently access data to fast regions. Simulation results show that the proposed techniques can improve the system performance by 10.2% and reduce the energy consumption on cache by 9.5% compared with conventional MLC STT-RAM cache design.

Are investors consistent in their trading strategies? An examination of individual investor-level data

While it has been demonstrated that momentum or contrarian trading strategies can be profitable in a range of institutional settings, less evidence is available concerning the actual trading strategies investors adopt. Standard definitions of momentum or contrarian trading strategies imply that a given investor applies the same strategy to both their buy and sell trades, which need not be the case. Using investor-level, transaction-based data from China, where tax effects are neutral, we examine investors' buy-sell decisions separately to investigate how past returns impact differentially on the trading strategies investors adopt when buying and selling stock. After controlling for a wide range of stock characteristics, extreme price changes and portfolio value, a clear asymmetry in trading is observed; with investors displaying momentum behavior when buying stocks, but contrarian behavior when selling stocks. This asymmetry in behavior is not driven purely by reactions to stock characteristics or extreme stocks. We discuss behavioral and cultural explanations for our findings.

Lateralized Functions in the Dog Brain

Understanding the complementary specialisation of the canine brain has been the subject of increasing scientific study over the last 10 years, chiefly due to the impact of cerebral lateralization on dog behaviour. In particular, behavioural asymmetries, which directly reflect different activation of the two sides of the dog brain, have been reported at different functional levels, including motor and sensory. The goal of this review is not only to provide a clear scenario of the experiments carried out over the last decade but also to highlight the relationships between dogs’ lateralization, cognitive style and behavioural reactivity, which represent crucial aspect relevant for canine welfare.

Rat embryonic fibroblasts immortalized by MRPS18-2 protein are target for NK-cells.

Overexpression of the human mitochondrial ribosomal protein MRPS18-2 (S18-2) led to immortalization of primary rat embryonic fibroblasts (REFs). The derived cells (18IM) expressed embryonic stem cell markers. Noteworthy, genes encoding the COX family proteins were up-regulated significantly. It is known that the COX family proteins are involved in the regulation of immune response.In the present work we demonstrate that 18IM cells behave like stem cells when subjected to directed differentiation in vitro. However, unlike stem cells, 18IM cells do not develop tumors in vivo, in SCID mice. This phenomenon is observed due to the strong natural killer (NK) cell immunogenicity. 18IM cells were better recognized by NK cells, compared with primary REFs, as was shown by a standard NK killing assay.Our data explain asymmetry in behavior of stem-like cells in vivo and in vitro, and this support the notion that stem and/or cancer-initiating cells are preferred targets for NK-cells. Concluding, the S18-2 protein is a putative target for cancer vaccines.

Source/Drain Asymmetry in InGaAs Vertical Nanowire MOSFETs

This paper demonstrates InGaAs vertical nanowire (VNW) MOSFETs fabricated via an improved top–down approach, the performance of which is comparable to that of the best bottom–up devices in terms of the balance between transport and electrostatics. These devices, when contrasted with an earlier generation fabricated by a similar technology, have enabled the first experimental study of source/drainasymmetry in InGaAs VNWMOSFETs. The transconductance differs significantly when swapping source and drain due to inherently different top and bottom contact electrical resistance. This also results in distinct asymmetry in the saturation behavior of the output characteristics. On the other hand, diameter nonuniformity along the nanowire (NW) length is responsible for asymmetry in the subthreshold characteristics. A uniform NW cross section, enabled by our improved InGaAs dry etch technology in the present devices, eliminates the asymmetry of the electrostatics, which was observed in our previous work.

The Genetics of Asymmetry: Whole Exome Sequencing in a Consanguineous Turkish Family with an Overrepresentation of Left-Handedness

Handedness is the most pronounced behavioral asymmetry in humans. Genome-wide association studies have largely failed to identify genetic loci associated with phenotypic variance in handedness, supporting the idea that the trait is determined by a multitude of small, possibly interacting genetic and non-genetic influences. However, these studies typically are not capable of detecting influences of rare mutations on handedness. Here, we used whole exome sequencing in a Turkish family with history of consanguinity and overrepresentation of left-handedness and performed quantitative trait analysis with handedness lateralization quotient as a phenotype. While rare variants on different loci showed significant association with the phenotype, none was functionally relevant for handedness. This finding was further confirmed by gene ontology group analysis. Taken together, our results add further evidence to the suggestion that there is no major gene or mutation that causes left-handedness.

Behavioural asymmetry in Devonian trilobites

The cephalon of the trilobite Phacopidae was usually separated from the thorax during moulting, and abandoned near the trunk. We statistically evaluated the distribution pattern of the cephala of Omegops cornelius, and found that near 70% of the total cephala were displaced on the right side, from the Upper Devonian deposits of the western Junggar in Northwest China. Omegops cornelius might have actively pushed the cephalon to the right of its body during moulting, indicating their preference to move counterclockwise. This preferred movement direction manifested the behavioural asymmetry in trilobites. A different type of asymmetry has been observed in Phacopidae Plagiolaria nandanensis from the Lower Devonian of Guangxi in South China, where about 67% of the cephala were found on the left side of the trilobite trunks. So the behavioural asymmetry may be diverse (or opposite) in different species of trilobites, and the reasons for the asymmetric moulting and movement patterns of the above two trilobites are likely related to their body structures, or their living environments. These new materials provide evidence for studying the origin and evolution of behavioural asymmetry.

Lord Eldon Redux: Information Asymmetry, Accountability and Fiduciary Loyalty

This article investigates the development of accountability and fiduciary loyalty as an institutional response to information asymmetries in agency relations, especially in firm-like settings. Lord Eldon articulated the crucial role of information asymmetries in opportunistic behaviour in the early 19th century, but its roots are much older. A 13th-century trend towards direct farming of English manors and the transformation of feudal accounting after the Domesday Book and early Exchequer period engendered profound developments. The manor emerged as (possibly the first) profit-maximising firm, complete with separation of ownership and control and a hierarchy of professional managers. This primordial firm relied on primordial fiduciary loyalty—an accountability regime backed by social norms that was tailored for addressing the acute information asymmetries in agency relations. Courts have gradually expanded this regime, which in due course enabled Equity to develop the modern duty of loyalty. These insights suggest implications for contemporary fiduciary loyalty.

Sex difference and Allee effects shape the dynamics of sex‐structured invasions

The rate at which a population grows and spreads can depend on individual behaviour and interactions with others. In many species with two sexes, males and females differ in key life-history traits (e.g. growth, survival and dispersal), which can scale up to affect population rates of growth and spread. In sexually reproducing species, the mechanics of locating mates and reproducing successfully introduce further complications for predicting the invasion speed (spread rate), as both can change nonlinearly with density. Most models of population spread are based on one sex, or include limited aspects of sex differences. Here we ask whether and how the dynamics of finding mates interact with sex-specific life-history traits to influence the rate of population spread. We present a hybrid approach for modelling invasions of populations with two sexes that links individual-level mating behaviour (in an individual-based model) to population-level dynamics (in an integrodifference equationmodel). We find that limiting the amount of time during which individuals can search for mates causes a demographic Allee effect which can slow, delay, or even prevent an invasion. Furthermore, any sex-based asymmetries in life history or behaviour (skewed sex ratio, sex-biased dispersal, and sex-specific mating behaviours) amplify these effects. In contrast, allowing individuals to mate more than once ameliorates these effects, enabling polygynandrous populations to invade under conditions where monogamously mating populations would fail to establish. We show that details of individuals' mating behaviour can impact the rate of population spread. Based on our results, we propose a stricter definition of a mate-finding Allee effect, which is not met by the commonly used minimum mating function. Our modelling approach, which links individual- and population-level dynamics in a single model, may be useful for exploring other aspects of individual behaviour that are thought to impact the rate of population spread.

Electrostatic forces and geometry of organic molecules. Part II. Unsaturated acyclic molecules with one double bond: C=C, C=O, or C=N

In the extension of the electrostatic approach developed in the previous paper on the basis of the available experimental and ab initio calculations data, the geometric structure of acyclic organic molecules containing one isolated chemical bond C=C, C=O, or C=N was analyzed. In agreement with conventional σ/π-representation for this type of bonds, the electrostatic model was suggested, comprising two kinds of local electron densities (LEDs) differing in topology and polarizability, which are in the close spin–spin interaction and show some asymmetry in behavior under the action of external perturbing electrostatic forces (ESFs). Based on the previously introduced concepts of LEDs, point positive charges (PPCs), directions of their most effective interaction (MEI) and using the procedure of fixed molecule (FM), the capabilities of the model were demonstrated on the examples of typical alkenes, carbonyl compounds, azomethines and oximes.

Rising Power on the Mind

AbstractA prominent explanation of war claims that international conflict can result when shifts in bargaining power induce the declining power to behave aggressively today because the rising power cannot credibly commit to not behave aggressively tomorrow. This paper asks whether individuals respond to shifting power in ways assumed by these models. Rather than use abstract laboratory-based bargaining games as in other work, I use vignettes describing the United States in an international bargaining situation to explore the microfoundations of power transitions models empirically. The vignettes vary whether the individual is a member of a declining or a rising power and whether there are previous public commitments to the status quo division of territory. Subjects propose a response the United States should make and then explain their decision in their own words. I apply new methods for analyzing these open-ended responses. Consistent with predictions from the behavioral literature, I find important asymmetries in behavior across these conditions as well as substantial heterogeneities in individuals' motivations for their decisions. The results of the experiments suggest potential ways that power-transition models should be refined to have a firmer behavioral basis.

Damage-induced alarm cues influence lateralized behaviour but not the relationship between behavioural and habenular asymmetry in convict cichlids (Amatitlania nigrofasciata).

Cerebral lateralization, the partitioning of functions into a certain hemisphere of the brain, is ubiquitous among vertebrates. Evidence suggests that the cognitive processing of a stimulus is performed with a specific hemisphere depending in part upon the emotional valence of the stimulus (i.e. whether it is appetitive or aversive). Recent work has implicated a predominance of right-hemisphere processing for aversive stimuli. In fish with laterally placed eyes, the preference to view an object with a specific eye has been used as a proxy for assessing cerebral lateralization. The habenula, one of the most well-known examples of an asymmetrical neural structure, has been linked to behavioural asymmetry in some fish species. Here, we exposed convict cichlid fish (Amatitlania nigrofasciata) to both a social and non-social lateralization task and assessed behavioural lateralization in either the presence or absence of an aversive stimulus, damage-induced alarm cues. We also assessed whether behavioural asymmetry in these tests was related to asymmetry of the habenular nuclei. We found that when alarm cues were present, fish showed increased left-eye (and by proxy, right hemisphere) preference for stimulus viewing. In addition, females, but not males, showed stronger eye preferences when alarm cues were present. We did not find a relationship between behavioural lateralization and habenular lateralization. Our results conflict with previous reports of concordance between behavioural and habenular lateralization in this fish species. However, our results do provide support for the hypothesis of increased right-hemisphere use when an organism is exposed to aversive stimuli.

Larval antlions with more pronounced behavioural asymmetry show enhanced cognitive skills.

Brain lateralization is hypothesized to improve the efficiency of information processing. Here, we found that some Myrmeleon bore antlion larvae showed individual asymmetry in righting from a supine to normal position over one side of their body, which can be considered a reflection of greater brain lateralization. We demonstrated that these behaviourally asymmetrical individuals showed improved learning abilities, providing novel evidence that brain lateralization leads to beneficial effects on cognitive functions.

Multiple behavioural asymmetries impact male mating success in the khapra beetle, Trogoderma granarium

Extensive research has recently been conducted to shed light on mating behavioural asymmetries in various species of vertebrates. However, little is available on this key issue for invertebrates, especially for species of the order Coleoptera. In the present study, we highlighted the presence of four population-level lateralized mating traits in the mating behaviour of an alien and invasive pest of stored products, the khapra beetle, Trogoderma granarium (Dermestidae). Male recognition and mounting, as well as the female post-copulation kicks, were left-biased, while male foreleg tapping acts were right-biased. Notably, left-biased asymmetries in the recognition approach led to significant differences in recognition duration, the number of head wagging acts, whole mating duration and, most importantly, male mating success. Overall, the results reported here represent a unique example of four subsequent mating traits lateralized at the population level which influence male mating success. From an applied perspective, the quantification of lateralized mating traits is expected to contribute to a better understanding of key biological traits of this species, which can be used for the prediction of its spread and population growth parameters.

Assessment of handedness and footedness by lateral preference inventory

Handedness is considered as the most obvious type of behavioral and cognitive asymmetry reported in human beings. Also we have footedness in the motor domain. This study investigated the percentage distribution and their significance for handedness and footedness in both sexes of adolescent age group in both left and right handers based on laterality preference inventory. Handedness got a significant result whereas footedness score has no significance based on the laterality preference inventory.

Власть и табу: о культурно-психологических истоках традиционализма

Traditionalism as a "return to traditional values" is widely represented today in the world political process, but it is particularly striking in the East. This phenomenon is analyzed from the standpoint of cultural-historical psychology. The revival of "archaic" manifestations is explained by the political elites’ (conscious or unconscious) appeal to deep layers of people's consciousness which provided the legitimacy of the "power of tradition" in the traditional society. The paper reveals the essence of this power embodied in social fear that had emerged together with first behavioral norms. It analyses taboo as a norm which initially labeled the hierarchy in the primary society, prescribing an asymmetry of behavior to the higher and lower strata (the ones in power and the ones in their power). There is a relation between the taboo and the psychophysiological mechanism of the prohibition (I. Pavlov, J. Castro) which transformed the "natural" fear into the "social" one. The paper describes the ambivalent nature of social fear as well as its intentional object: representatives of the higher strata (L. Vygotsky). The archetype of power behavior is illustrated by the political practices of the East where taboos in the shape of «absurd laws», religious and etiquette norms are widely existent in the legal field of this region’s states. This archetype also largely determines the behavior of politicians which often appears in archaic forms. Similar "psychological documents" (L. Vygotsky) are recorded in the behavior of actors in the political process of the West.

Behavioral Asymmetries of Pectoral Fin Use During Social Interactions of Bottlenose Dolphins (Tursiops truncatus)

The preference for utilizing certain appendages (handedness) has been explored in human and nonhuman primates. Similarly to primates, dolphins possess hemispheres that allow an individual to present behaviorally dominant features as well as appendages (i.e., pectoral fins) that are utilized both as social facilitators as well as means to interact with objects. Thus, the possibility of handedness in a captive population of 27 bottlenose dolphins (Tursiops truncatus) was explored. Dolphins in a mother-offspring relationship made significantly more pectoral fin contacts than in the absence of this relationship (p < 0.001). No significant difference was observed between maternal siblings and non-maternal siblings in overall pectoral fin contact. Handedness indexes were calculated for 26 individuals that initiated pectoral fin contact with both conspecifics and flora (i.e., seagrass) in their habitat. No significant differences were observed between the sexes in handedness indexes, however calves displayed a significant right-fin handedness compared to both sub-adults and adults (p < 0.05). Both sub-adults and adults showed a left-fin handedness indexes, but no significant difference in the strength of this relationship among these two age classes was observed. Individual variation in handedness indexes was noted. These results suggest that handedness may be present in Atlantic bottlenose dolphins with regards to social contact, and a larger and more diverse sample size may provide a better understanding in why handedness may change across development.

Right hemisphere advantage in the development of route fidelity in homing pigeons

Several laboratory studies have revealed functional hemispheric lateralization in birds performing visual tasks. However, the role of functional brain asymmetries in spatial behaviour in natural settings is still poorly investigated. We studied monocularly occluded homing pigeons, Columba livia, to investigate potential differences in the hemispheric control of navigational performance. We GPS-tracked monocularly occluded and control binocular homing pigeons during seven group training releases and a final solitary release from each of two sites. The pigeons were then given one last release from each site after a phase shift of the light-dark cycle under binocular conditions, to distinguish compass-based orientation from landmark-based pilotage. Overall, pigeons homing with the left eye/right hemisphere (RH) displayed a greater fidelity to the familiar space previously experienced than pigeons homing with the right eye/left hemisphere (LH). Another difference between the two monocular groups is that LH pigeons were more likely than RH pigeons to fly with other pigeons during the group training releases. The data support the hypothesis that the left eye/right hemisphere plays a more substantial role as pigeons develop fidelity to certain routes to home from familiar release sites, an enhanced fidelity that may be supported by superior memory for familiar landmarks.

Model-Based and Design-Based Inference: Reducing Bias Due to Differential Recruitment in Respondent-Driven Sampling

Respondent-driven sampling (RDS), a link-tracing sampling and inference method for studying hard-to-reach populations, has been shown to produce asymptotically unbiased population estimates when its assumptions are satisfied. However, some of the assumptions are prohibitively difficult to reach in the field, and the violation of a crucial assumption can produce biased estimates. We compare two different inference approaches: design-based inference, which relies on the known probability of selection in sampling, and model-based inference, which is based on models of human recruitment behavior and the social context within which sampling is conducted. The advantage of the latter approach is that when the violation of an assumption has been shown to produce biased population estimates, the model can be adjusted to more accurately reflect actual recruitment behavior, and thereby control for the source of bias. To illustrate this process, we focus on three sources of bias, differential effectiveness of recruitment, a form of nonresponse bias, and bias resulting from status differentials that produce asymmetries in recruitment behavior. We first present diagnostics for identifying types of bias and then present new forms of a model-based RDS estimator that controls for each type of bias. In this way, we show the unique advantages of a model-based estimator.

Effects of induced placental and fetal growth restriction, size at birth and early neonatal growth on behavioural and brain structural lateralization in sheep

ABSTRACTPoor perinatal growth in humans results in asymmetrical grey matter loss in fetuses and infants and increased functional and behavioural asymmetry, but specific contributions of pre- and postnatal growth are unclear. We therefore compared strength and direction of lateralization in obstacle avoidance and maze exit preference tasks in offspring of placentally restricted (PR: 10M, 13F) and control (CON: 23M, 17F) sheep pregnancies at 18 and 40 weeks of age, and examined gross brain structure of the prefrontal cortex at 52 weeks of age (PR: 14M, 18F; CON: 23M, 25F). PR did not affect lateralization direction, but 40-week-old PR females had greater lateralization strength than CON (P = .021). Behavioural lateralization measures were not correlated with perinatal growth. PR did not alter brain morphology. In males, cross-sectional areas of the prefrontal cortex and left hemisphere correlated positively with skull width at birth, and white matter area correlated positively with neonatal growth rate of the skull (all P < .05). These studies reinforce the need to include progeny of both sexes in future studies of neurodevelopmental programming, and suggest that restricting in utero growth has relatively mild effects on gross brain structural or behavioural lateralization in sheep.