The objective of the study was to investigate the effect of pre-synchronisation on the occurrence of the oestrus and pregnancy rate after fixed time artificial insemination (FTAI) in synchronised ewes during the anoestrous season. Kivircik ewes (n = 84) were randomly assigned to one of the two treatment groups with (PRE; n = 42) or without (SYN; n = 42) pre-synchronisation. In the SYN group, the ewes were subjected to a 7-d short-term protocol (P4 insertion-6d-PGF2α-1d-P4 removal + eCG). In the PRE group, the same short-term protocol as in the SYN group was applied with 7 days apart for a pre-synchronised synchronisation protocol. A cervical FTAI was performed with fresh semen at 54 h after sponge removal. At the beginning of the synchronisation protocol, the oestrous response (66.7% vs. 0.0%) and cyclicity rates (64.3% vs. 14.3%) based on progesterone (P4) were higher in the PRE group compared to those in the SYN group, respectively (P < 0.01). However, the oestrous response after synchronisation was lower within 96 h (57.1% vs. 95.2%; P < 0.01) in the PRE group compared to that in the SYN group. Although the pregnancy rate after the FTAI was significantly (P < 0.05) lower in the PRE group (14.3%) than the SYN group (35.7%), the overall pregnancy rate after natural mating was not different (95.2%) between the groups. In conclusion, the pre-synchronisation decreased the oestrous response leading to a lower pregnancy rate after the FTAI in the synchronised ewes during the anoestrous season. Thus, attention should be paid to two consecutive administrations of eCG in a pre-synchronisation and synchronisation protocol in ewes.

• Klíčová slova
• artificial insemination, pregnancy rate, progesterone, sheep,
• Publikační typ
• časopisecké články MeSH

The changes of spatial EEG synchronisation during brisk and slow voluntary self-paced movements of the right and left index finger were analysed in 12 right-handed and 11 left-handed subjects. EEG was recorded from the left and right sensorimotor area using 24 closely spaced electrodes. A novel measure of spatial EEG synchronisation, omega-complexity, was computed separately for the left and right sensorimotor area in 64 overlapping one-second epochs representing 4.5 s of the pre-movement and 3.5 s of the post-movement period. Omega-complexity was higher, hence spatial synchronisation was lower, in slow than in brisk movements, especially in the right-handed. A sustained increase of omega-complexity was observed during execution of a slow movement. A decrease of omega-complexity which was often associated with a brief burst of spatially synchronised 10-Hz oscillations occurred at the onset of extensor muscle contraction. We suggest that increased spatial EEG synchronisation at movement onset may prevent "spillover" of excitation from the sensorimotor hand area to other cortical regions. During movement, the cortical neuronal assemblies subserve distinct, specialised functions manifesting in increased omega-complexity.

• MeSH
• analýza rozptylu MeSH
• čití, cítění fyziologie   MeSH
• dospělí MeSH
• elektroencefalografie MeSH
• funkční lateralita fyziologie   MeSH
• korová synchronizace * MeSH
• lidé MeSH
• mapování mozku metody   MeSH
• pohyb fyziologie   MeSH
• prsty ruky inervace   MeSH
• psychomotorický výkon fyziologie   MeSH
• reakční čas fyziologie   MeSH
• retrospektivní studie MeSH
• ruka inervace   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In this study we explore how music can entrain human walkers to synchronise to the musical beat without being instructed to do so. For this, we use an interactive music player, called D-Jogger, that senses the user's walking tempo and phase. D-Jogger aligns the music by manipulating the timing difference between beats and footfalls. Experiments are reported that led to the development and optimisation of four alignment strategies. The first strategy matched the music's tempo continuously to the runner's pace. The second strategy matched the music's tempo at the beginning of a song to the runner's pace, keeping the tempo constant for the remainder of the song. The third alignment starts a song in perfect phase synchrony and continues to adjust the tempo to match the runner's pace. The fourth and last strategy additionally adjusts the phase of the music so each beat matches a footfall. The first two strategies resulted in a minor increase of steps in phase synchrony with the main beat when compared to a random playlist, the last two strategies resulted in a strong increase in synchronised steps. These results may be explained in terms of phase-error correction mechanisms and motor prediction schemes. Finding the phase-lock is difficult due to fluctuations in the interaction, whereas strategies that automatically align the phase between movement and music solve the problem of finding the phase-locking. Moreover, the data show that once the phase-lock is found, alignment can be easily maintained, suggesting that less entrainment effort is needed to keep the phase-lock, than to find the phase-lock. The different alignment strategies of D-Jogger can be applied in different domains such as sports, physical rehabilitation and assistive technologies for movement performance.

• MeSH
• akustická stimulace MeSH
• algoritmy MeSH
• bezdrátová technologie MeSH
• chůze * MeSH
• elektrické vybavení a zdroje MeSH
• hudba * MeSH
• lidé MeSH
• mladý dospělý MeSH
• noha (od hlezna dolů) fyziologie   MeSH
• technologie přístrojové vybavení   metody   MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Acquisition of new skills is often implemented by the formation of coordinated movements of functionally unrelated muscles. This situation was modelled in rats trained to lick at a retractable spout which was automatically withdrawn after termination of every lick but could be returned by pressing and releasing a lever placed 4 cm below the spout. Rats (n = 12) learned to perform short presses (50 ms) synchronized with the lick cycle in a way allowing continuous drinking. When the distance of the lever from the box was increased from 5 mm to 12.5 mm or when the force required for lever operation was raised from 20 g to 90 g, the lick-press interval increased in multiples of the interlick interval. Licking ceased during the lever pressing but regular timing of subsequent licks indicated uninterrupted activity of the licking generator. It is concluded that the coordination of orofacial and forelimb muscles engaged in licking and lever pressing, respectively, is accomplished by propagation of the activity of the lick generator to cortical and subcortical motor centers.

• MeSH
• apetenční chování fyziologie   MeSH
• arousal fyziologie   MeSH
• chování při pití fyziologie   MeSH
• jazyk inervace   MeSH
• krysa rodu Rattus MeSH
• mapování mozku MeSH
• motorické dovednosti fyziologie   MeSH
• mozkový kmen fyziologie   MeSH
• operantní podmiňování fyziologie   MeSH
• pozornost fyziologie   MeSH
• přední končetina inervace   MeSH
• psychomotorický výkon fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Many recent studies show that synchronisation of various behaviours are advantageous for group-living mammals. However, studies on synchronisation of suckling behaviour inmonotocous species are nearly absent. We observed 49 individual foals of three zebra species in Dvůr Králové Zoo, and recorded a total of 5 890 suckling bouts, almost one fifth (1 036) of which were synchronised (defined as at least two bouts overlapping at the same time). We found that synchronised suckling bouts lasted longer and were less likely to be terminated by the mother than non-synchronised ones. This is in line with social facilitation theory. In addition the occurrence of synchronised suckling bout differed interspecifically. In plains (Equus quagga) and mountain zebra (E. zebra) the probability of synchronised bouts increased with increasing numbers of foals, whereas the opposite result was found in Grevy's zebra (E. grevyi). We suggest that the interspecific differences may reflect differences in social organisation of respective species as suckling synchronisation rate was higher in species that form nurseries in the wild.

• Klíčová slova
• Equids, Social facilitation, Suckling behaviour, Synchronisation,
• MeSH
• Equidae * MeSH
• koně MeSH
• matky MeSH
• sociální facilitace * MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Experimental and theoretical studies have shown that ephaptic coupling leads to the synchronisation and slowing down of spikes propagating along the axons within peripheral nerve bundles. However, the main focus thus far has been on a small number of identical axons, whereas realistic peripheral nerve bundles contain numerous axons with different diameters. Here, we present a computationally efficient spike propagation model, which captures the essential features of propagating spikes and their ephaptic interaction, and facilitates the theoretical investigation of spike volleys in large, heterogeneous fibre bundles. We first lay out the theoretical basis to describe how the spike in an active axon changes the membrane potential of a passive axon. These insights are then incorporated into the spike propagation model, which is calibrated with a biophysically realistic model based on Hodgkin-Huxley dynamics. The fully calibrated model is then applied to fibre bundles with a large number of axons and different types of axon diameter distributions. One key insight of this study is that the heterogeneity of the axonal diameters has a dispersive effect, and that a higher level of heterogeneity requires stronger ephaptic coupling to achieve full synchronisation between spikes.

• Klíčová slova
• Ephaptic coupling, Peripheral nerves, Spike propagation, Synchronisation,
• MeSH
• akční potenciály fyziologie   MeSH
• axony * fyziologie   MeSH
• membránové potenciály MeSH
• nervová vlákna * MeSH
• periferní nervy MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The ability to emit and receive signals over long distances is one of the characteristic attributes of multicellular organisms. Such communication can be mediated in different manners (by chemical compounds, light waves, acoustic waves etc.) and usually is reflected in the behaviour of the communicating organisms. Recently, we reported that individual yeast colonies, organised multicellular structures, can also communicate at long distance by means of volatile ammonia, which is produced by colonies in pulses separated by acidification of the medium. Here, we demonstrate that the colony that first reached the stage of intense ammonia production induces ammonia production response in surrounding colonies regardless of their age, causing the synchronisation of their NH(3) pulses and, consequently, the mutual affection of their growth. Also an artificial source of ammonia (but neither NH(4)(+) nor NaOH gradients) can immediately induce the ammonia production even in the colony starting its acidic stage of the development. The repeated transition of Candida mogii colonies from the acidic phase to the phase of intensive ammonia production is accompanied by dramatic changes in colony morphology and also in cell morphology and growth. Relatively smooth colonies in the acidic phase are formed by growing pseudohyphae. After ammonia induction, pseudohyphae decompose into non-dividing yeast-like cells, which rearrange themselves into ruffled spaghetti-like structures. The synchronisation of colony growth, that also exists between yeast colonies of different genera, could be important in establishing their optimal distribution in a natural habitat.

• MeSH
• amoniak metabolismus   farmakokinetika   MeSH
• buněčné dělení účinky léků   fyziologie   MeSH
• Candida růst a vývoj   fyziologie   MeSH
• mezibuněčná komunikace účinky léků   fyziologie   MeSH
• mikrobiologické techniky MeSH
• signální transdukce účinky léků   fyziologie   MeSH
• velikost buňky účinky léků   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• amoniak MeSH

The relationship between network structure and dynamics is one of the most extensively investigated problems in the theory of complex systems of recent years. Understanding this relationship is of relevance to a range of disciplines-from neuroscience to geomorphology. A major strategy of investigating this relationship is the quantitative comparison of a representation of network architecture (structural connectivity, SC) with a (network) representation of the dynamics (functional connectivity, FC). Here, we show that one can distinguish two classes of functional connectivity-one based on simultaneous activity (co-activity) of nodes, the other based on sequential activity of nodes. We delineate these two classes in different categories of dynamical processes-excitations, regular and chaotic oscillators-and provide examples for SC/FC correlations of both classes in each of these models. We expand the theoretical view of the SC/FC relationships, with conceptual instances of the SC and the two classes of FC for various application scenarios in geomorphology, ecology, systems biology, neuroscience and socio-ecological systems. Seeing the organisation of dynamical processes in a network either as governed by co-activity or by sequential activity allows us to bring some order in the myriad of observations relating structure and function of complex networks.

• Klíčová slova
• chaotic oscillators, excitable dynamics, modular graphs, random graphs, scale-free graphs, synchronisation,
• MeSH
• ekologie * MeSH
• ekosystém * MeSH
• mozek MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Direct effects of climate change on animal physiology, and indirect impacts from disruption of seasonal synchrony and breakdown of trophic interactions are particularly severe in Arctic and Alpine ecosystems. Unravelling biotic from abiotic drivers, however, remains challenging because high-resolution animal population data are often limited in space and time. Here, we show that variation in annual horn growth (an indirect proxy for individual performance) of 8043 male Alpine ibex (Capra ibex) over the past four decades is well synchronised among eight disjunct colonies in the eastern Swiss Alps. Elevated March to May temperatures, causing premature melting of Alpine snowcover, earlier plant phenology and subsequent improvement of ibex food resources, fuelled annual horn growth. These results reveal dependency of local trophic interactions on large-scale climate dynamics, and provide evidence that declining herbivore performance is not a universal response to global warming even for high-altitude populations that are also harvested.

• Klíčová slova
• Alpine ungulates, European Alps, body size, climate change, ecological response, horn growth, phenotypic plasticity, plant phenology, spatial synchrony, trophic interaction,
• MeSH
• klimatické změny * MeSH
• kozy růst a vývoj   MeSH
• lineární modely MeSH
• roční období * MeSH
• rohy růst a vývoj   MeSH
• teplota * MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• dopisy MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Švýcarsko MeSH

• MeSH
• buněčné jádro fyziologie   MeSH
• dieta MeSH
• histologické techniky MeSH
• karyometrie MeSH
• krysa rodu Rattus MeSH
• mitóza MeSH
• slzné ústrojí cytologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH