Quantifying Social Asymmetric Structures

Many social phenomena involve a set of dyadic relations among agents whose actions may be dependent. Although individualistic approaches have frequently been applied to analyze social processes, these are not generally concerned with dyadic relations nor do they deal with dependency. This paper describes a mathematical procedure for analyzing dyadic interactions in a social system. The proposed method mainly consists of decomposing asymmetric data into their symmetrical and skew-symmetrical parts. A quantification of skew-symmetry for a social system can be obtained by dividing the norm of the skew-symmetrical matrix by the norm of the asymmetric matrix. This calculation makes available to researchers a quantity related to the amount of dyadic reciprocity. Regarding agents, the procedure enables researchers to identify those whose behavior is asymmetric with respect to all agents. It is also possible to derive symmetric measurements among agents and to use multivariate statistical techniques

Effectiviteit energiebesparingsbeleid in de glastuinbouw

De inzet van twee fiscale beleidsinstrumenten, de Energie-investeringsaftrek (EIA) en de Vrije afschrijving milieu-investeringen (Vamil), blijkt de investering in energiebesparende technieken wel te stimuleren, maar niet aantoonbaar te leiden tot energiebesparing. De fiscale maatregelen worden door glastuinbouwbedrijven in ruime mate gebruikt, maar deze bedrijven gaan niet efficiënter met energie om dan de niet-gebruikers

Asymmetric scaling models for square contingency tables: points, circles, arrows and odds ratios

Multivariate analysis of psychological dat

Modeling Asymmetric Exchanges Between Clusters

A nonhierarchical clustering model is proposed here which jointly fits the symmetric and skew-symmetric components of an asymmetric pairwise dissimilarity matrix. Two similar clustering structures are defined depending on two (generally different) partitions of the objects: a “complete” partition fitting the symmetries (where all objects belong to some cluster) and an “incomplete” partition fitting the skew-symmetries, where only a subset of objects is assigned to some cluster, while the remaining ones may remain non-assigned. The exchanges between clusters are accounted for by the model which is formalized in a least squares framework and an appropriate Alternating Least Squares algorithm is provided to fit the model to illustrative real data

Cerebrospinal Fluid and Plasma Amine Profiles in Interictal Migraine

Objective: Impaired amine metabolism has been associated with the etiology of migraine, that is, why patients continue to get migraine attacks. However, evidence from cerebrospinal fluid (CSF) is lacking. Here, we evaluated individual amine levels, global amine profiles, and amine pathways in CSF and plasma of interictal migraine patients and healthy controls. Methods: CSF and plasma were sampled between 8:30 am and 1:00 pm, randomly and interchangeably over the time span to avoid any diurnal and seasonal influences, from healthy volunteers and interictal migraine patients, matched for age, sex, and sampling time. The study was approved by the local medical ethics committee. Individual amines (n = 31), global amine profiles, and specific amine pathways were analyzed using a validated ultraperformance liquid chromatography mass spectrometry platform. Results: We analyzed n = 99 participants with migraine with aura, n = 98 with migraine without aura, and n = 96 healthy volunteers. Univariate analysis with Bonferroni correction indicated that CSF L-arginine was reduced in migraine with aura (10.4%, p < 0.001) and without aura (5.0%, p = 0.03). False discovery rate-corrected CSF L-phenylalanine was also lower in migraine with aura (6.9%, p = 0.011) and without aura (8.1%, p = 0.001), p = 0.088 after Bonferroni correction. Multivariate analysis revealed that CSF global amine profiles were similar for both types of migraine (p = 0.64), but distinct from controls (p = 0.009). Global profile analyses were similar in plasma. The strongest associated pathways with migraine were related to L-arginine metabolism. Interpretation: L-Arginine was decreased in the CSF (but not in plasma) of interictal patients with migraine with or without aura, and associated pathways were altered. This suggests that dysfunction of nitric oxide signaling is involved in susceptibility to getting migraine attacks. ANN NEUROL 2023