Processing and model design of the gamma oscillation activity based on FitzHugh-Nagumo model and its interaction with slow rhythms in the brain

The brain is processing information 24 hours a day. There are millions of processes proceeding in it accompanied by various spectra of rhythms. This paper tests the hypothesis that the slow delta rhythm excites the gamma rhythm oscillations. Unlike other papers, we determine the slow rhythm spectrum not at the hypothesis stage but during the experiment. We design algorithms of filtering, envelope extraction, and correlation coefficient calculation for signal processing. Moreover, we examine the data on all electroencephalogram channels, which allows us to make a more reasonable conclusion. We confirm that a slow delta rhythm excites a fast gamma rhythm with an amplitude-phase type of interaction and calculate a delay between these two signals equal to about half a second.

Attentional brain rhythms during prolonged cognitive activity

As routine and lower demand cognitive tasks are taken over by automated assistive systems, human operators are increasingly required to sustain cognitive demand over long periods of time. This has been reported to have long term adverse effects on cardiovascular and mental health. However, it remains unclear whether prolonged cognitive activity results in a monotonic decrease in the efficiency of the recruited brain processes, or whether the brain is able to sustain functions over time spans of one hour and more. Here, we show that during working sessions of one hour or more, contrary to the prediction of a monotonic decline, behavioral performance in both humans and non-human primates consistently fluctuates between periods of optimal and suboptimal performance at a very slow rhythm of circa 5 cycles per hour. These fluctuations are observed in both high attentional (in non-human primates) and low attentional (in humans) demand conditions. They coincide with fluctuations in pupil diameter, indicating underlying changes in arousal and information-processing load. Accordingly, we show that these rhythmic behavioral fluctuations correlate, at the neurophysiological level, with fluctuations in the informational attention orientation and perception processing capacity of prefrontal neuronal populations. We further identify specific markers of these fluctuations in LFP power, LFP coherence and spike-field coherence, pointing towards long-range rhythmic modulatory inputs to the prefrontal cortex rather than a local prefrontal origin. These results shed light on the resilience of brain mechanisms to sustained effort and have direct implications on how to optimize high cognitive demand working and learning environments.

ALAIN DELON AS PROTAGONIST OF THE BEGINNING OF THE END

The beginning of the end is a special category of beginning. The beginning of the end is a dramatic / pathetic / romantic / existential process in general. Within this process, the beginning becomes the end, and the end becomes the beginning. Sometimes it has a slow rhythm, sometimes it is experienced with a breathless speed. Coincidences shape this process, at the same time, intuition plays a crucial role in defining it. Beginning of the end can be experienced socially or individually. Like the historical / mass / chaotic beginnings of the end, there are also individuals who represent beginning of the end within rebellion / sacrifice / victimization or auto-destruction acts. The beginning of the end is sometimes a relative emancipation process. Paradoxically, fear and courage, violence and humanistic principles are intertwined. It’s also a perfect theme for artistic inspiration and creativity. Historically, there have been many "beginning of the end" periods. However, the period between the fall of the Austro-Hungarian Empire and Auschwitz is particularly important, and this topic is the subject of this article. In this context, Joseph Roth, Roman Vishniac, László Nemes, Joseph Losey, Alain Delon are some representatives of this topic in their respective fields with their works. In this paper, the phenomenon of “the beginning of the end” and its features will be developed using descriptive method. <p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/edu_01/0770/a.php" alt="Hit counter" /></p>

La configuración archivística en el cine de no ficción contemporáneo

This article deals with the works of filmmakers and artists who self-impose certain protocols linked to archival configuration to structure and make sense of their films or videos. In this way, collecting, classifying, making lists, series or catalogues will be common practices in this type of work, thus following some of the steps of the art-archive binomial that starts at the beginning of the 20th century with photographic archives such as Augène’s Atget or August Sander and that expands and develops through various artistic practices to this day. Radical documentary pieces with a clear allusion to photography - showing special attention in the portrait and landscape - and where repetitive structures, fixed planes and, in general, a slow rhythm that invites contemplation proliferate. Countenance (2002) by Fiona Tan, Twenty Cigarettes (2011) by James Benning, Ruinas (2009) by Manuel Mozos or Equí y n’otru tiempu (2014) by Ramón Lluís Bande are some of the examples of this cinema that appropriates archival principles, not only to question the very idea of archive, but also as a non-narrative strategy that probes the possibilities of what cinema is and can be.

Cortical silencing results in paradoxical fMRI overconnectivity

ABSTRACTfMRI-based measurements of functional connectivity are commonly interpreted as an index of anatomical coupling and direct interareal communication. However, causal testing of this hypothesis has been lacking. Here we combine neural silencing, resting-state fMRI and in vivo electrophysiology to causally probe how inactivation of a cortical region affects brain-wide functional coupling. We find that chronic silencing of the prefrontal cortex (PFC) via overexpression of a potassium channel paradoxically increases rsfMRI connectivity between the silenced area and its thalamo-cortical terminals. Acute chemogenetic silencing of the PFC reproduces analogous patterns of overconnectivity, an effect associated with over-synchronous fMRI coupling between polymodal thalamic regions and widespread cortical districts. Notably, multielectrode recordings revealed that chemogenetic inactivation of the PFC attenuates gamma activity and increases delta power in the silenced area, resulting in robustly increased delta band coherence between functionally overconnected regions. The observation of enhanced rsfMRI coupling between chemogenetically silenced areas challenges prevailing interpretations of functional connectivity as a monotonic index of direct axonal communication, and points at a critical contribution of slow rhythm generators to the establishment of brain-wide functional coupling.

A case of suspected antibiotic-associated encephalopathy in a patient undergoing long-term peritoneal dialysis

A man undergoing long-term peritoneal dialysis who had no history of mental illness suffered psychosis and auditory hallucination 2 days after clindamycin was initiated at a single dose of 0.6 g per day for pulmonary infection. His mental symptoms disappeared after clindamycin was discontinued and peritoneal dialysis was strengthened. The patient’s body temperature was mildly elevated the day before he was admitted to the hospital, and no abnormalities were observed on head and chest computed tomography imaging at admission, except for a slow rhythm on electroencephalogram. Many factors were involved in this case; antibiotic-related encephalopathy caused by clindamycin may be one factor. Physicians should carefully consider the use of antibiotics, especially in patients with end-stage renal disease.

Analysis of the agricultural productivity of the sugarcane crop in regions of new agricultural expansions of sugarcane

The launching of biofuel vehicles in 2003 led to ethanol demand increase and a new phase of expansion of sugarcane cultivation in Brazil. Although the increase in area of production and the quantity of sugarcane produced have been very important to Brazilian agribusiness, the recent agricultural productivity rate has slowed. In this context, this article analyzed the factors that influence the growth rate of sugarcane productivity in the regions of new agricultural expansions, specifically in the states of Mato Grosso do Sul and Goias. For the collection and data analysis, we used bibliographical and documentary research. The shift-share method was used to analyze the evolution of sugarcane production, through the decomposition of this variable into two factors: area effect and productivity effect. The results show that the increase in production in the region under analysis was mainly due to the incorporation of new planting areas and not to an increase in productivity. In addition, structural factors have negatively impacted crop performance. The analysis indicates that there is a slow rhythm of sugarcane fields’ renovation and the adoption of old varieties. Although the mechanization index is high in the studied regions, difficulties of technological adaptation still provide deficiency in the agricultural performance of sugarcane.

Selective Interareal Synchronization through Gamma Frequency Differences and Slower-Rhythm Gamma Phase Reset

The communication-through-coherence (CTC) hypothesis states that a sending group of neurons will have a particularly strong effect on a receiving group if both groups oscillate in a phase-locked (“coherent”) manner (Fries, 2005 , 2015 ). Here, we consider a situation with two visual stimuli, one in the focus of attention and the other distracting, resulting in two sites of excitation at an early cortical area that project to a common site in a next area. Taking a modeler’s perspective, we confirm the workings of a mechanism that was proposed by Bosman et al. ( 2012 ) in the context of providing experimental evidence for the CTC hypothesis: a slightly higher gamma frequency of the attended sending site compared to the distracting site may cause selective interareal synchronization with the receiving site if combined with a slow-rhythm gamma phase reset. We also demonstrate the relevance of a slightly lower intrinsic frequency of the receiving site for this scenario. Moreover, we discuss conditions for a transition from bottom-up to top-down driven phase locking.

The Effect of Weight Training with Fast and Slow Rhythm Movement towards Strength Enhancement

Kamal Firdaus, 2012. The Effect of Weight Training with Fast and Slow Rhythm Movement towards Strength Enhancement. Strength is the most important physical conditions in doing various activities, either daily activities or sports activities. One can not do much when there is no power. In the world of sports, generally the elements of power play a fairly important. In addition for those those truly need a power such as heavy weight, wrestling, boxing and other sports branches. The achievements competitiveness in sports happens because there are so many prizes and bonuses which are promised when somebody becomes a champion, it makes people strive to improve their performance in many ways in terms of strength. One of the efforts is from physical exercises. Physical exercise to increase strength is by lifting weights. The impact of other forms of weight training can be done to increase the strength. In this research, the writer would only look at the effect of weight training with a fast beat and slow rhythm towards the rate of strength enhancement. As for those who tried to be included in the study were derived from the population of boys grade I and II of SMA Negeri 3 Padang. From the total of the population, the writer randomized as many as 40 people as a sample. After these two groups underwent the initial tests, then the writer tried to divide them into 2 groups again, with each group consisting of 20 people. Before the treatment was conducted, some boys were given out the trial tests. This initial test was conducted to determine the level of initial strength owned by sample and tried to divide people into two homogeneous groups. After the sample had done the initial tests and had been divided into two groups, then for group I was given the weight training treatment with fast rhythm, while the second group was given the treatment of weight training with a slow rhythm. Treatment was given for 2 months with the practice intensity was 3 times per week. After the sample tried to complete their training program, then do another test (final test). This second test functions to see how much the influence of the treatment given by the trainer comparing to the results of preliminary tests. From the data analysis, it can be seen that; Weight training with fast rhythm movement can enhance the strength significantly . It is based on P <0.05 or value tO> from t table. Weight training with slow motion rhythm can enhance the strength significantly It is based on P <0.05 or value tO> of the t table. There were no differences in strength enhancement by conducting the treatment of weight training with fast rhythm and slow rhythm. It is proved that P> 0.05 or value tO < of t table.