SIGNATURES OF MULTI-STATE SYSTEMS BASED ON A SERIES/PARALLEL/RECURRENT STRUCTURE OF MODULES

In this paper, we consider multi-state coherent systems that can be regarded as a series/parallel/recurrent connection of multi-state modules with binary/multi-state components. The multi-state (survival) signatures of such systems are presented in terms of multi-state (survival) signatures of related modules based on the structures. For a recurrent structure, the multi-state survival signature of the structure is also needed. The results established here are finally illustrated with a number of examples.

Whole-brain computational modeling reveals disruption of microscale brain dynamics in HIV infected individuals

In this study, we adopted the relaxed mean-field dynamic modeling to investigate structural and functional connectivity in forty-two HIV-infected subjects before and after 12-week of combination antiretroviral therapy (cART) and compared them with forty-six age-matched healthy subjects. Microscale brain dynamics were modeled by a set of parameters including two region-specific microscale brain properties, recurrent connection strengths, and subcortical inputs. We also analyzed the relationship between the model parameters (i.e. the recurrent connection and subcortical inputs) and functional network topological characterizations. The results show that untreated HIV-infected individuals have disrupted local brain dynamics that in part correlate with network topological measurements. Notably, after 12 weeks of cART, both the microscale brain dynamics and the network topological measurements improved and were closer to those in the healthy brain. This was also associated with improved cognitive performance, suggesting that improvement in local brain dynamics translates into clinical improvement.

On a Ricci quarter-symmetric metric recurrent connection and a projective Ricci quarter-symmetric metric recurrent connection in a Riemannian manifold

Two new types of connections, Ricci quarter-symmetric metric recurrent connection and projective Ricci quarter-symmetric metric recurrent connection, were introduced and some interesting geometrical and physical characteristics were achieved.

Geometries for a mutual connection of semi-symmetric metric recurrent connections

A semi-symmetric metric recurrent connection has already been studied. In this paper we newly discovered geometrical properties and conjugate symmetric condition for the mutual connection of a semi-symmetric metric recurrent connection in a Riemannian manifold.

Goal-Directed, Spontaneous, and Stimulus-Independent Thoughts and Mindwandering in a Competitive Context

The aim of this study was to analyze the functions of goal-directed thoughts and the content of spontaneous and stimulus-independent thoughts and mindwandering in a competitive setting and to explore links between different types of thoughts. Therefore, 17 young sport science students competed in a card-sorting task, while their recorded thoughts were collected between trials. Afterwards, the participants classified their own transcripts into different types of thoughts. The results indicated that goal-directed thinking serves a variety of functions, that spontaneous thought content might reflect a series of psychological states and processes relevant for performance, and that the content of mindwandering was idiosyncratic. Moreover, goal-directed thinking increased during competition, whereas mindwandering diminished. Lastly, mindwandering was rarely connected to other types of thinking, whereas the most recurrent connection between thoughts was found between goal-directed and spontaneous thinking.

On a generalized quarter symmetric metric recurrent connection

We introduce a generalized quarter-symmetric metric recurrent connection and study its geometrical properties. We also derive the Schur?s theorem for the generalized quarter-symmetric metric recurrent connection.

Flexible adaptation to an artificial recurrent connection from muscle to peripheral nerve in man

Controlling a neuroprosthesis requires learning a novel input-output transformation; however, how subjects incorporate this into limb control remains obscure. To elucidate the underling mechanisms, we investigated the motor adaptation process to a novel artificial recurrent connection (ARC) from a muscle to a peripheral nerve in healthy humans. In this paradigm, the ulnar nerve was electrically stimulated in proportion to the activation of the flexor carpi ulnaris (FCU), which is ulnar-innervated and monosynaptically innervated from Ia afferents of the FCU, defined as the “homonymous muscle,” or the palmaris longus (PL), which is not innervated by the ulnar nerve and produces similar movement to the FCU, defined as the “synergist muscle.” The ARC boosted the activity of the homonymous muscle and wrist joint movement during a visually guided reaching task. Participants could control muscle activity to utilize the ARC for the volitional control of wrist joint movement and then readapt to the absence of the ARC to either input muscle. Participants reduced homonymous muscle recruitment with practice, regardless of the input muscle. However, the adaptation process in the synergist muscle was dependent on the input muscle. The activity of the synergist muscle decreased when the input was the homonymous muscle, whereas it increased when it was the synergist muscle. This reorganization of the neuromotor map, which was maintained as an aftereffect of the ARC, was observed only when the input was the synergist muscle. These findings demonstrate that the ARC induced reorganization of neuromotor map in a targeted and sustainable manner.