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7802. Homeostatic modulation of stimulation-dependent plasticity in human motor cortex

Creator:
Ilić, N. V., Milanović, S., Krstić, J., Bajec, Đ. D., Grajić, M., and Ilić, T. V.
Format:
print
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, transkraniální magnetická stimulace, transcranial magnetic stimulation, paired associative stimulation, motor cortex, homeostatic plasticity, 14, and 612
Language:
English
Description:
Since recently, it is possible, using noninvasive cortical stimulation, such as the protocol of paired associative stimulation (PAS), to induce the plastic changes in the motor cortex, in humans that mimic Hebb's model of learning. Application of TMS conjugated with peripheral elec trical stimulation at strictly coherent temporal manner lead to convergence of inputs in the sensory-motor cortex, with the consequent synaptic potentiation or weakening, if applied repeti tively. However, when optimal interstimulus interval (ISI) for induction of LTP-like effects is applied as a single pair, Motor evoked potential (MEP) amplitude inhibition is observed, the paradigm known as short-latency afferent inhibition (SLAI). Aiming to resolve this paradox, PAS protocols were applied, with 200 re petitions of TMS pulses paired with median nerve electrical stimul ation, at ISI equa l to individual latencies of evoked response of somatosensory cortex (N20) (PASLTP), and at ISI of N20 shortened for 5 msec (PASLTD) - protocols that mimic LTP-like changes in the human motor cortex. MEP amplitudes before, during and after interventions were measured as an indicator based on output signals originating from the motor system. Post-intervention MEP amplitudes following the TMS protocols of PASLTP and PASLTD were facilitated and depressed, respectively, contrary to MEP amplitudes during intervention. During PASLTP MEP amplitudes were significantly decreased in case of PASLTP , while in the case of PASLTD an upward trend was observed. In conclusions, a possible explanation for the seemingly paradoxical effect of PAS can be found in the mechanism of homeostatic modulation of plasticity. Those findings indicate the existence of complex relationships in the development of plasticity induced by stimulation, depending on the level of the previous motor cortex excitability., N. V. Ilić., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

7804. Homérowa Iliada

Creator:
Homéros and Vlček, Jan B. Josef
Publisher:
Jan Spurný
Format:
print and 440, [4] s. 1 mapa : front. ; 21 cm
Type:
model:monograph and TEXT
Subject:
beletrie-poezie (sbírkový fond), vzácné tisky 19. stol. (sbírkový fond), vzácné a historické tisky MKP (sbírkový fond), starořecká poezie, and starořecká literatura
Language:
Czech
Description:
Poezie v češtině pro dospělé, mládež a starší děti.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

7806. Homines Scientiarum

Creator:
Marina Hužvárová
Format:
print, bez média, and svazek
Type:
article, zprávy, reports, model:article, and TEXT
Subject:
Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce, Ústav pro soudobé dějiny (Akademie věd ČR)., Kabinet dějin vědy, vědecká práce, filozofie a věda, vzdělanost, scientific work, philosophy and science, educational attainment, Česko, Czechia, 12, and 00
Language:
Czech
Description:
Marina Hužvárová.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

7810. Homogamie a internet: Pomáhají online seznamky rozumět výběrovému párování

Creator:
Šetinová, Markéta
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
partnerský výběr, mate selection, partner selection, homogamy, assortative mating, online dating, 18, and 316.4/.7
Language:
Czech
Description:
Non-random selection of reproductive partners in the human population, i.e. assortative mating, has been a stable occurrence for decades and across societies, including the Czech Republic. Social sciences have paid primary attention to homogamy, marriage between similar partners, also due to its potential impact on society. High levels of homogamy in a society may imply high closedness of the different groups, prevent social mobility, suggest racial tensions, or lead to higher inequality. Three factors are deemed as responsible for homogamy. Structural factors are represented by the partners’ physical closeness as they meet, for example, at school or other institutions. Second, there are individual factors, namely one’s personal preferences for a relationship with someone similar to one. Finally, social factors represent the influence of social groups as they have their own stake in preserving group cohesion through marriage between their members. However, evidence of assortative mating and its mechanisms mostly comes from attitudinal data or questionnaire surveys, which make it difficult to differ between individual and structural factors, among others. In this review article, I focus on the potential of data from online dating sites to help us better understand assortative mating. Is the Internet changing the ways people meet? How does assortative mating work in the online environment and what can it tell us about the mating process in general? The paper starts by presenting the main theories of assortative mating and adding information on the specifics of the online environment. There are basically two contradictory expectations of the effect of the Internet on the mating process. The first group assumes that the easy access to thousands of potential partners across all sociodemographic groups an online dating service provides, plus the absence of direct influence of intermediaries such as community members, will lead to higher diversity of the ensuing marriages. In short, the level of assortative mating will decrease. The opposite expectation is based on the assumption that people generally prefer contact with similar partners and online dating services help them more effectively filter mates by preferred criteria, thus avoiding contact with people who do not fit their expectations. As a result, assortative mating will grow. The theory section is followed by a review of contemporary international research of online dating services with regard to assortative mating. I conclude the detailed review by arguing that the human preference for similar partners occurs in the online environment as well, and therefore, assortative mating likely cannot be explained by structural factors only. Moreover, all points to the fact that data from real-life user interaction in online dating services can importantly widen our knowledge of assortative mating., Markéta Šetinová., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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