In this study, we questioned whether ground-level ozone (O3) induces hormesis in Japanese larch (Larix kaempferi) and its hybrid F1 (L. gmelinii var. japonica × L. kaempferi). In order to answer the question, we exposed seedlings of both taxa to four O3 treatments [ranging from ≈10 to 60 nmol(O3) mol-1] in open-top chambers for two consecutive growing seasons. We found a hormetic response in maximum photosynthetic rate (PNmax) at 1700 μmol(CO2) mol-1 and maximum rates of carboxylation (Vcmax) and electron transport (Jmax) in both larches. Stimulation of PNmax, Vcmax, and Jmax did not lead to suppressed plant productivity in Japanese larch, which followed a stress-tolerant strategy, but it did lead to suppressed plant productivity in hybrid larch which followed a competitive strategy. These findings are the first to suggest that stimulation of physiological functions by low O3 exposures may have negative consequences for larch reproduction., T. Sugai, D.-G. Kam, E. Agathokleous, M. Watanabe, K. Kita, T. Koike., and Obsahuje bibliografii
In the parthenogenetic monogeneans of the genus Gyrodactylus Nordmann, 1832, the genetic diversity within or between hosts is determined by the relative roles of lateral transmission and clonal propagation. Clonality and limited transmission lead to high-amplitude metapopulation dynamics and strong genetic drift. In Baltic populations of the three-spined stickleback Gasterosteus aculeatus Linnaeus, the local mitochondrial diversity of Gyrodactylus arcuatus Bychowsky, 1933 is very high, and spatial differentiation weak. To understand the transmission dynamics in a single location, the transmission of the parasite from adults to next generation sticklebacks was investigated in a northern Baltic brackish water location. By sequencing 777 nt of cox1, as many as 38 separate mitochondrial haplotypes were identified. In August, the intensity of gyrodactylid infection on adult hosts was high, the haplotype diversity (h) was extreme and differentiation between fish was negligible (total h = 0.926, mean h = 0.938). In October, only 46% of the juvenile sticklebacks carried G. arcuatus. The number of parasites per young fish followed a Poisson distribution 0.92 ± 1.04 (mean ± SD) on October 2, and was clearly overdispersed 2.38 ± 5.00 on October 25. The total haplotype diversity of parasites on juveniles was nearly as high as in adults (h = 0.916), but the mean per fish was only h = 0.364 (FST = 0.60), due to low intensity of infection and rapid clonal propagation of early arrivals. The initial first come first served advantage of the first gyrodactylid colonisers will be lost during the host adulthood via continuous transmission. Nesting and polygamy are suggested as factors maintaining the high genetic diversity of the parasite population. The transmission dynamics and, consequently, the population structure of Baltic G. arcuatus is fundamentally different from that of G. salaris Malmberg, 1957, on the Baltic salmon Salmo salar Linnaeus., Jaakko Lumme, Marek S. Ziętara., and Obsahuje bibliografii
Jana Cahlíková, Lubomír Cingl, Ian Levely., Částečně tištěno napříč, Obsahuje bibliografii a bibliografické odkazy, České a anglické resumé, and born digital
The impact of the arrival of the exotic coccinellid Harmonia axyridis on the biological control and dispersion of apple mites and aphids, and on the vertical distribution of the established coccinellids Coccinella septempunctata and Coleomegilla maculata have been studied. Assemblages of adults of the three coccinellid species were tested on apple saplings and on apple trees against Aphis citricola and Tetranychus urticae. The presence or substitution of adults of H. axyridis for adults of C. maculata or C. septempunctata did not reduce the predation impact on mite or aphid prey. H. axyridis was a more efficient predator of mites than was C. septempunctata and generated lower prey dispersal from host plants. Substitutions of adults of H. axyridis for those of C. maculata, and in some cases of C. septempunctata, resulted in greater reduction in number of aphids. On apple trees, the three coccinellid species occurred at different heights. Neither C. maculata nor C. septempunctata modified their vertical distribution on apple tree over a 24 hour period in response to the presence of H. axyridis.
In the internal French Alps, subalpine grasslands become dominated by the tussock grass, Festuca paniculata, when mowing ceases. Does litter or living plants affect seedling recruitment in these subalpine communities, and does this vary between mown and unmown grasslands? Can the vegetation patterns observed in the field be related to the effects of F. paniculata? These hypotheses were tested using both a field and pot experiment. Seedlings of Bromus erectus, a subordinate species in these grasslands, were used as phytometers in both experiments. At both mown and unmown subalpine grassland sites in the French Alps, a removal experiment was established. This field experiment included removal of litter and living vegetation in order to differentiate their respective effect on seedling establishment. Vegetation and litter had contrasting effects. Vegetation affected the recruitment success of B. erectus by limiting seedling growth at the mown site and survival at the unmown site. Litter modified recruitment only at the unmown site, where it increased survival but limited growth. Survival and growth of seedlings responded to different environmental factors. Survival was determinedmore by soilmoisture, while growth probably dependedmore on light availability.Where there is a thick litter layer, as is the case in unmown subalpine grasslands, the competitive effect of vegetation can be counterbalanced by an increase in soil moisture due to the litter reducing rate of evaporation of water. The effect on seedlings of the presence of Festuca paniculata, the dominant species at these sites, was also quantified using a pot experiment, including a cutting treatment. This experiment showed that the competitive effect of the vegetation could be largely explained by the inhibitory effect on growth of the dominant species, F. paniculata. This study provides a better understanding of the processes that result in conservative plants, such as F. paniculata, becoming dominant in these subalpine environments upon cessation of traditional management practices.
Competition is a major force organizing ant communities and results in co-occurring species evolving different strategies for foraging and use of space. Territorial species, as top dominants exclude each other, while shaping the local ant communities both qualitatively and quantitatively. In this study we examined how two territorial species, Formica polyctena and Lasius fuliginosus, can coexist in adjacent territories over long periods of time, and whether they affect co-occurring species of ants in different ways. Field observations in the absence and in the presence of baits were carried out around a L. fuliginosus nest complex surrounded by a polydomous F. polyctena colony in S Finland in 2007–2009. Both species controlled their territories, but were affected by changes in the abundance of the other species and the distance from L. fuliginosus’ main nest. They did not have the same effect on the subordinate species in the absence of baits, but the abundance of Myrmica spp. recorded at baits was negatively affected by both of the territorial species. The preferences of the different species for the artificial food sources differed: L. fuliginosus and F. polyctena preferred tuna to honey and Myrmica spp. honey to tuna. More individuals of the subordinate species were recorded in the territory of F. polyctena than of L. fuliginosus, although conflicts with this territorial species were also recorded. During the three years of the study almost no overlaps in the territories of the two territorial species were recorded, and there were mostly minor shifts in the boundaries of the territories. Differences between the two territorial species in their use of space and competitive effects ensured their coexistence at this particular site in Finland., Wojciech Czechowski ... [et al.]., and Obsahuje seznam literatury
Earlier this month, the Czech media reported that a highly efficient antiviral drug developed by Czech scientists has been shelved, reportedly for fear it would compete with existing medicines manufactured by pharmaceutical giants. The substance, known as MK-612, was designed at the Academy´s Institute of Organic Chemistry and Biochemistry. Academic Bulletin interviewed Zdeněk Havlas, headmaster of the Institute, about next stage in the future of this efficient substance MK-612. and Marina Hužvárová.
Mammals have the ability to identify particular conspecifics and in doing so use this information to discriminate between them, and respond in a manner that increases their survival and fitness. This narrative focuses on the behavioral challenges that voles face when they have to make decisions about mate choice, samesex competition, odor communication, and sperm allocation. The narrative points out the different decisions that voles may make when they encounter the social information contained in the scent marks and over-marks of different conspecifics. The narrative demonstrates that the choices made by voles, and their resulting behaviors, may depend on several factors including the vole’s own condition, age, and sex and those of nearby same- and opposite-sex conspecifics. The results of these studies are ecologically relevant as they reflect situations and challenges faced by free-living voles. The range of situations that voles find themselves and the decisions voles make when they encounter a potential mate or competitor become the backdrop of the narrative. Concentrating on the responses of a single model species was intentional. This approach may allow specific comparisons with other terrestrial mammals, facing similar behavioral and ecological challenges.
In mammalian carnivore guilds (order Carnivora), spatiotemporal partitions play a major role in reducing competitive confrontations and facilitating successful sympatry. Using camera-trapping techniques, the present study aimed to elucidate patterns of spatial distribution and diel activities among medium- and large-sized carnivore species across central Bulgaria. We obtained 3,364 images of nine focal carnivores from 13,988 camera-trapping days between 2015 and 2020. Our findings indicated that the spatial distribution of the focal carnivore guilds varied with changes in altitudinal gradient, ruggedness, and forest-agricultural landscape changes. Specifically, the two largest species, the grey wolf (Canis lupus Linnaeus, 1758) and the brown bear (Ursus arctos Linnaeus, 1758), were found only in the Balkan Mountains, whereas the largest mesocarnivore, the golden jackal (Canis aureus Linnaeus, 1758), was mainly distributed agricultural lowlands. The European wildcat (Felis sylvestris Schreber, 1777) was found in forests inside protected areas, and other mesocarnivores were distributed at intermediate levels between wooded-mountains and agricultural lowlands. Brown bear, golden jackal, and domestic dog (Canis lupus familiaris Linnaeus, 1758) showed cathemeral, crepuscular, and diurnal activity, respectively, whereas the remaining six carnivores showed nocturnal activity in synchrony with their main prey. Our findings indicated that anthropogenic landscape modifications and potential interspecific competition resulted in patterns of spatial distribution and temporal activity in this carnivore guild.
Tento článek hodnotí jev označovaný jako sportovní národnost z pohledu práva Evropské unie. Jeho cílem je posoudit soulad pravidel mezinárodních sportovních organizací upravujících příslušnost sportovců k národním týmům s konkrétními ustanoveními unijního práva. Jedná se především o ta ustanovení, která rozvíjejí zákaz diskriminace na základě státní příslušnosti v oblastech vnitřního trhu a hospodářské soutěže. Pravidla upravující sportovní národnost jsou v práci rozdělena do čtyř skupin podle toho, jak se k nim se zřetelem ke své stávající rozhodovací praxi v budoucnu pravděpodobně postaví Soudní dvůr Evropské unie. Nejprve je zkoumána otázka, zda tato pravidla vůbec spadají do působnosti práva EU, tudíž i do jurisdikce unijních soudních orgánů. V případě kladné odpovědi je dále posuzováno, zda představují překážku volnému pohybu a v případě, že ano, je hodnoceno, zda je takové omezení jako výjimka v unijním právu ospravedlnitelné a přiměřené. Výjimky jsou zkoumány z pohledu Smluv i na základě bohaté sportovní judikatury Soudního dvora Evropské unie. Vědom si neustále se zvyšujícího ekonomického dopadu sportovní činnosti dal Soudní dvůr ve svém rozsudku Meca-Medina & Majcen z roku 2006 posuzování souladu pravidel upravujících sportovní národnost s unijním právem úplně nový rozměr. and This contribution assesses sporting nationality under EU law. Its aim is to consider compliance of the rules governing athletes’ eligibility in national teams with the concrete provisions of EU law. The provisions under scrutiny are mostly those laying down the prohibition of discrimination on the basis of nationality in the fields of internal market and competition. The rules governing sporting nationality are divided into four groups according to the attitude of the Court of Justice of the European Union, which might be expected according to its current case law. The contribution firstly considers whether these rules fall within the scope of EU law and therefore must be reviewed by EU judicial authorities. If so, it is assessed whether the sporting rules constitute a restriction on provisions on free movement. Finally, the justification for and the proportionality of such restrictions are
discussed. The restrictions are assessed from the perspective of the Treaties and the case law of the Court of Justice. In its Meca-Medina & Majcen judgment of 2006, the Court gave a completely new dimension to assessing the compliance of the rules governing athletes’ eligibility with EU law.