A topological method for detecting the new emergence of magnetic flux using SOHO/MDI magnetograms of the full solar disk is proposed. This method uses the number of pixels in the image that can be distinguished from a specified value to within a predetermined threshold (the number of disconnected components). We study more than ten very powerful active regions (ARs) with very high flare activity and show that the number of disconnected components increases directly before the development of a series of M and X flares, or accompanies this process. This behaviour is evident not only when there is an explicit emergence of a new flux and a series of fast flares, such as in AR 9236 (November 2000), but also in groups with many non-stationary processes developing along a neutral line of the large-scale magnetic field. We also discuss the possibility of using the obtained results for flare prediction.

This work analyzes the temporal evolution for three active regions (ARs) (AR 2034, AR 2035, and AR 2036). In terms of complexity, these are objects with high a priori probability of flares. However, their actual flare scenarios proved to be very different. The temporal evolution of ARs is analyzed with modern prognostic parameters and descriptors obtained by methods of computational topology. We show that these methods are more suitable for describing the actual situation. We note that the change in complexity descriptors for prognostic problems is more important than the set of characteristics themselves.

A quantitative description of the geometry and topology of the magnetic field of the Sun is given in terms of Minkowski functionals: the Euler characteristic and the perimeter of excursion sets for specified levels. Methods of mathematical morphology are applied to background fragments of magnetograms for the entire solar disk. The results obtained show that the topological characteristics of the background field are stable in time and correspond to log-normal, intermittent random fields.

Themain purpose of this paper is to describe the evolution of the magnetic field of active regions of the Sun in the context of Minkowski functionals: the Euler characteristic and perimeter calculated on the excursion set for a specified level. Themethods of geometry of random fields was applied to the MDI SOHO magnetogram, containing flaring active regions. The results demonstrated that morphological functional tracked the dynamic scenarios of the magnetic fields preceded by flares or accompanying them.

Two prominent features of obsessive-compulsive disorder (OCD) are the inability to inhibit intrusive thoughts and behaviors and pathological doubt or intolerance of uncertainty. Previous study showed that uncertain context modeled by equiprobable presentation of excitatory (Go) and inhibitory (NoGo) stimuli requires non-selective response inhibition in healthy subjects. In other words, it requires transient global inhibition triggered not only by excitatory stimuli but also by inhibitory stimuli. Meanwhile, it is unknown whether OCD patients show abnormal brain activity of the non-selective response inhibition system. In order to test this assumption, we performed an fMRI study with an equiprobable Go/NoGo task involving fourteen patients with OCD and compared them with 34 healthy controls. Patients with OCD showed pathological slowness in the Go/NoGo task. The non-selective response inhibition system in OCD included all brain areas seen in healthy controls and, in addition, involved the right anterior cingulate cortex (ACC) and the anterior insula/frontal operculum (AIFO). Moreover, a between-group comparison revealed hypoactivation of brain regions within cingulo-opercular and cortico-striato-thalamo-cortical (CSTC) circuits in OCD. Among hypoactivated areas, the right ACC and the right dorsolateral prefrontal cortex (DLPFC) were associated with non-selective inhibition. Furthermore, regression analysis showed that OCD slowness was associated with decreased activation in cingulate regions and two brain areas related to non-selective inhibition: the right DLPFC and the right inferior parietal lobule (IPL). These results suggest that non-selective response inhibition is impaired in OCD, which could be a potential explanation for a relationship between inhibitory deficits and the other remarkable characteristic of OCD known as intolerance of uncertainty.