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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is widely assumed that aggressive behavior affects space acquisition in territorial species, but to date most workers have focused on competition for indivisible space, that is, space that cannot be divided or shared. We present a learning-based model that investigates the effects of aggressive interactions on space acquisition when unequal competitors arrive and settle in patches of divisible space. This model assumes that aggressive interactions act as punishment, in the sense that previous aggressive interactions in a given area reduce an individual's likelihood of returning to that area. Individually based, spatially explicit simulations incorporating this and other assumptions were used to investigate the effects of different types of aggressive interactions on the space use of individuals and dyads settling in divisible space. At the individual level, final space use was related to the amount of punishment that individuals inflicted on their opponents during aggressive interactions; in general, highly aggressive individuals acquired larger, more exclusive home ranges than less aggressive individuals. At the dyadic level, the division or sharing of space between competitors depended on both the relative and absolute punishment that competitors inflicted on one another during aggressive interactions. Aggressive interactions in which both participants strongly punished one another (e.g., escalated fights) produced mutually exclusive home ranges, interactions with intermediate levels of punishment produced asymmetrical space use patterns proportional to asymmetries in punishment levels, and interactions involving little punishment for either participant generated large home ranges with extensive home range overlap. Overall, our model implies that territorial animals need not "win" aggressive interactions to win divisible space, that repeatedly "nagging" an opponent may also be a viable strategy for gaining space, and that a learning-based approach can account for puzzling patterns in the territorial literature, for example, observations of individuals who acquire space by initiating aggressive interactions that they never win.
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PMID:How territorial animals compete for divisible space: a learning-based model with unequal competitors. 1870 69

Macaque social relationships differ greatly between species. Based on captive studies that focus mainly on females, researchers have classified stumptail macaque (Macaca arctoides) social relationships as tolerant, as indicated by a high rate of affiliation, frequent aggression, and symmetrical conflicts. To accumulate more data on male social relationships, which are relatively understudied, and to generate comparative data, we investigated male social relationships in a provisioned group of 68 free-ranging, naturally dispersing stumptail macaques in southern Thailand. We collected continuous focal animal and ad libitum data on 7 adult and 2 subadult males, recording social behavior during 283 contact hours between December 2006 and March 2007. Stumptail macaques of this population were less tolerant than predicted based on previous studies on captive groups: Rates of spatial proximity, affiliation, and aggression were low, most males directed affiliative behavior toward higher-ranking males, and conflicts were generally of low intensity and relatively asymmetrical. Thus, male stumptail macaques of the focal group appear to differ in their social style from a previous study of a captive group that mainly comprised of females. In some traits, they are even more intolerant than rhesus macaques, an intensively studied intolerant macaque species. We also compare our data on stumptail macaque males to those on other male macaques, but available data are too sparse to draw final conclusions.
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PMID:Social Relationships in Free-Ranging Male Macaca arctoides. 1964 54

This study aimed to evaluate neuroendocrine and cardiovascular responses together with changes in brain asymmetry following an anger mood induction laboratory task. Previous research has shown an increase in heart rate and blood pressure when anger is experienced. Increased testosterone and decreased cortisol in response to anger and aggressive behavior have also been reported. With regard to asymmetrical frontal brain activity and emotion, the valence model links negative affect (as anger) to the right hemisphere while the motivational direction model links approach-related emotions (as anger) to the left hemisphere. From the subjective perception and from the neuroendocrine and cardiovascular response of the subjects, we can conclude that the self-referent statement anger induction method by Engebretson et al. (1999) was able to generate an experience of an anger affect in 30 healthy men. Another question was to analyze the consequences of that experience upon perceptual asymmetry when measured with a non-emotional laterality task. Regarding dichotic listening, an enhanced REA (right ear advantage) was observed after anger which indicates greater left hemisphere activity, supporting the motivational direction model.
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PMID:What happens when we get angry? Hormonal, cardiovascular and asymmetrical brain responses. 2004 13

Central to our understanding of social group formation and maintenance is the question of how within-group conflict resolution is achieved in the face of asymmetrical competition over resources and reproduction. A crucial yet implicit assumption of many conflict resolution models dealing with reproductive skew is that subordinates have perfect knowledge of the extent of conflict between themselves and their dominants, enabling behavioural responses on an individual rather than evolutionary scale. However, a mechanism enabling subordinates to accurately assess their relative conflict levels has yet to be empirically demonstrated. Here, we show in the angelfish Centropyge bicolor that the rate of overt mild aggression from dominants to subordinates acts as a signal of increasing rank conflict. The clarity of this signal can be reduced by spatial segregation, causing subordinates to be less able to respond appropriately by regulation of their foraging rates. A reduced signal ultimately leads to a less well-defined dominance hierarchy and destabilization of the social group. Our study suggests that, contrary to previous suggestions, dominant aggression rates play a crucial role as an accurate information signal required for the evolutionary stability of skew models.
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PMID:Aggression, segregation and stability in a dominance hierarchy. 2005 47

While a germline activating mutation of the luteinizing hormone receptor (LHR) gene is known to cause autonomous production of testosterone from testicular Leydig cells in male-limited precocious puberty, only a few studies have addressed the role of somatic LHR mutation in testicular pathology. The authors report a case of a 6-year-old boy who developed secondary sex characteristics including facial acne, enlarging genitalia, and aggressive behavior, for which serial biochemical evaluation confirmed the status of peripheral precocious puberty. Examination revealed asymmetrical testicular volume, following which a left testicular tumor was detected through ultrasonography. A left orchiectomy was performed, and histopathology revealed a well-circumscribed Leydig cell tumor Molecular study of the exon 11 of the LHR gene revealed a missense mutation at the nucleotide position 1,732, leading to a substitution of histidine for aspartic acid at codon 578. Interestingly, the substitution was consistent with all previously reported LHR alteration in pediatric Leydig cell adenoma, but which had never before been reported in male-limited precocious puberty, suggesting that the mutation is a molecular signature of the adenoma.
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PMID:Peripheral precocious puberty in a male caused by Leydig cell adenoma harboring a somatic mutation of the LHR gene: report of a case. 2087 84

Cross-sectional and longitudinal predictors of mutual and nonmutual intimate partner violence (IPV) perpetration were identified in a sample of female college freshmen (N = 499). Using female reports, couples were classified as to whether the relationship included no IPV, female-only IPV, or mutual IPV (male-only IPV was too rare to analyze). Mutual IPV was more common than asymmetrical IPV, and women in mutually violent relationships perpetrated more frequent acts of physical aggression than those in female-only violent relationships. In cross-sectional analyses of IPV in the first semester of college, only partner antisocial behavior and psychological aggression distinguished female-only IPV from no IPV; witnessing mother-to-father aggression, higher psychological aggression, more frequent partner marijuana use, partner antisocial behavior, and, surprisingly, higher relationship satisfaction, discriminated mutual IPV from no IPV. Contrary to hypothesis, first semester (T1) IPV did not predict having a new partner in the second semester (T2); however, women who reported more frequent heavy episodic drinking and lower relationship satisfaction at T1 were more likely to be in a different relationship at T2. Prospective prediction of T2 IPV category failed to support the hypothesis that female-only IPV would escalate to mutual IPV. The majority of couples with female-only IPV reported no IPV at T2. After accounting for T1 IPV, the only significant predictor of T2 IPV category was T1 psychological aggression, suggesting that this may be an appropriate target for IPV prevention efforts among college dating couples.
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PMID:Female intimate partner violence perpetration: stability and predictors of mutual and nonmutual aggression across the first year of college. 2146 1

Emotion perception is necessarily imprecise, leading to possible overperception or underperception of a given emotion extant in a target individual. When the costs of these two types of errors are recurrently asymmetrical, categorization mechanisms can be expected to be biased to commit the less costly error. Contextual factors can influence this asymmetry, resulting in a concomitant increase in biases in the perception of a given emotion. Anger motivates aggression, hence an important contextual factor in anger perception is the capacity of the perceived individual to inflict harm. The greater the capacity to harm, the more costly it is to underestimate the extent to which the target is angry, and therefore the more that perception should be biased in favor of overestimation. Consonant with this prediction, in two studies, U.S. adults perceived greater anger when models were holding household objects having affordances as weapons (e.g., garden shears) than when they were holding objects lacking such affordances (e.g., a watering can) or were empty-handed. Consistent with the unique relationship between anger and aggression, this positive bias did not appear in judgments of other negative emotions.
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PMID:If looks could kill: anger attributions are intensified by affordances for doing harm. 2474 38

Sexual selection on multiple signals may lead to differential rates of signal introgression across hybrid zones if some signals contribute to reproductive isolation but others facilitate gene flow. Competition among males is one powerful form of sexual selection, but male behavioral responses to multiple traits have not been considered in a system where traits have introgressed differentially. Using playbacks, mounts, and a reciprocal experimental design, we tested the hypothesis that male responses to song and plumage in two subspecies of red-backed fairy-wren (Malurus melanocephalus) explain patterns of differential signal introgression (song has not introgressed, whereas plumage color has introgressed asymmetrically). We found that males of both subspecies discriminated symmetrically between subspecies' songs at a long range, but at a close range, we found that aggression was equal for both subspecies' plumage and songs. Taken together, our results suggest that male behavioral responses hinder the introgression of song, but allow for the observed asymmetrical introgression of plumage. Our results highlight how behavioral responses are a key component of signal evolution when recently divergent taxa come together, and how differential responses to multiple signals may lead to differential signal introgression and novel trait combinations.
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PMID:Differential rates of phenotypic introgression are associated with male behavioral responses to multiple signals. 2629 44

Research on hybridization between species provides unparalleled insights into the pre- and postzygotic isolating mechanisms that drive speciation. In social organisms, colony-level incompatibilities may provide additional reproductive barriers not present in solitary species, and hybrid zones offer an opportunity to identify these barriers. Here, we use genotyping-by-sequencing to sequence hundreds of markers in a hybrid zone between two socially polymorphic ant species, Formica selysi and Formica cinerea. We characterize the zone, determine the frequency of hybrid workers, infer whether hybrid queens or males are produced and investigate whether hybridization is influenced by colony social organization. We also compare cuticular hydrocarbon profiles and aggression levels between the two species. The hybrid zone exhibits a mosaic structure. The asymmetric distribution of hybrids skewed towards F. cinerea suggests a pattern of unidirectional nuclear gene flow from F. selysi into F. cinerea. The occurrence of backcrossed individuals indicates that hybrid queens and/or males are fertile, and the presence of the F. cinerea mitochondrial haplotype in 97% of hybrids shows that successful F1 hybrids will generally have F. cinerea mothers and F. selysi fathers. We found no evidence that social organization contributes to speciation, because hybrids occur in both single-queen and multiple-queen colonies. Strongly differentiated cuticular hydrocarbon profiles and heightened interspecific aggression further reveal that species recognition cues are both present and perceived. The discovery of fertile hybrids and asymmetrical gene flow is unusual in ants, and this hybrid zone will therefore provide an ideal system with which to investigate speciation in social insects.
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PMID:Ants exhibit asymmetric hybridization in a mosaic hybrid zone. 2750 80

Previous studies have shown that Siamese fighting fish, Betta splendens, preferentially use right-eye during the aggressive displays. However, administration of antidepressant drugs may disrupt eye-use preference in association with a reduction in aggression; a phenomena that has not been explored in fish. The objective of the current study was to examine the effects of exposure to the antidepressant drug, fluoxetine, on lateralization in eye-use during aggressive displays in male Siamese fighting fish. Baseline aggression and lateralization in eye use of thirty fish were assessed toward live conspecifics, following which experimental subjects (n=15) were then exposed to fluoxetine (540ng/L) in a static renewal water system. Behavior was quantified again after 9 days of exposure. All of the subjects preferentially used the right-eye during aggressive responses before the exposure experiments. Fluoxetine exposed subjects showed a reduction in the time spent gill flaring as has previously been reported, indicative of a reduction in the level of aggression. Fluoxetine also had a significant effect on the lateralization in preferred eye-use while looking at their opponent. Fish exposed to fluoxetine switched from a preferential use of the right-eye during aggressive encounters prior to exposure to using their left-eye after exposure to fluoxetine. The results are discussed with regard to asymmetrical distribution of serotonin between the two brain hemispheres.
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PMID:Prozac impacts lateralization of aggression in male Siamese fighting fish. 2823 86


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