In this paper we study the structure of standard Einstein solvmanifolds of arbitrary rank. Also the validity of a variational method for finding standard Einstein solvmanifolds is proved.

Learning the true rank ordering among objects by aggregating a set of expert opinion rank order lists is an important and ubiquitous problem in many applications ranging from social choice theory to recommendation systems and search aggregation. We study the problem of unsupervised rank aggregation where no ground truth ordering information in available, neither about the true preference orderi...

Status within social hierarchies has great effects on the lives of socially organized mammals. Its effects on human behavior and related physiology, however, is relatively little studied. The present study investigated the impact of military rank on fairness and behavior in relation to salivary cortisol (C) and testosterone (T) levels in male soldiers. For this purpose 180 members of the Austri...

The enormous influence of hierarchical rank on social interactions [1] suggests that neural mechanisms exist to process status-related information [2] and ascribe value to it. The ventral striatum is prominently implicated in processing value and salience, independent of hedonic properties [3, 4], and a functional magnetic resonance imaging (fMRI) study of social status perception in humans dem...

Background: Evidence suggests that stress plays a role in changes in body weight and disordered eating. The present study examined the effect of mood, affect systems (attachment and social rank) and affect regulatory processes (self-criticism, self-reassurance) on the stress process and how this impacts on changes in weight and disordered eating. Methods: A large sample of women participated in...

Social relationships between group members are a key feature of many animal societies. The quality of social relationships has been described by three main components: value, compatibility and security, based on the benefits, tenure and stability of social exchanges. We aimed to analyse whether this three component structure could be used to describe the quality of social relationships in wild ...

According to the relative rank hypothesis (RRH), the magnitudes of sensory stimuli are estimated relative to their rank among related comparators. This study assessed the RRH in social drinkers and tested whether rank breath alcohol concentration is a better predictor of subjective alcohol risk estimates. The design was a crosssectional alcometer street survey. Data from 1997 respondents (mean ...

Learning the true ordering between objects by aggregating a set of expert opinion rank order lists is an important and ubiquitous problem in many applications ranging from social choice theory to natural language processing and search aggregation. We study the problem of unsupervised rank aggregation where no ground truth ordering information in available, neither about the true preference orde...