In the last two decades a huge amount of research has focused on the invasive harlequin ladybird, Harmonia axyridis, particularly on potential or actual deleterious effects that have arisen after it has colonised new regions. A focus of this work has been real or anticipated declines in native ladybird abundance since the introduction of H. axyridis, for which it is deemed responsible. Scientists have generally painted a very bleak picture of the effects of H. axyridis on native species: in this paper I argue that the picture painted is often too bleak. I use the case of the 2-spot ladybird, Adalia bipunctata, the species most often invoked as threatened by H. axyridis, to illustrate my point. While there is little question that H. axyridis has led to a decline in A. bipunctata populations in Europe, it seems likely that prior to the invasive ladybird's arrival A. bipunctata occurred in artificially high numbers in the urban environments in which it was typically studied. Pollution in towns and cities led to enhanced numbers of prey aphids on plants there which initially favoured A. bipunctata, and later H. axyridis. Thus one species, A. bipunctata, that has benefitted from an association with humans has been replaced by another, H. axyridis, just as brown rats replaced black rats in Europe and North America. Viewed with a longer perspective, A. bipunctata has more likely declined back to pre-industrial levels: the artificially high level from which it has declined recently was not a 'natural' one, and thus its decline from this level does not imply that it is now threatened or endangered. More broadly, we need a wider perspective, encompassing other ladybirds, longer timeframes and better comparisons with other (non-ladybird) invasive species to more clearly assess whether H. axyridis really poses as much of a threat as is often proposed., John J. Sloggett., and Obsahuje bibliografii
Archeologický a stavebně historický výzkum minoritského areálu v Mostě probíhal v letech 1971–1976 v souvislosti s likvidací významného historického města. Výzkum se soustředil na poznání vývoje kostela a klausury mosteckých minoritů ve 13.–14. stol. a na objasnění pozice jejich konventu uvnitř městského organismu. Konvent stával takřka uprostřed města, k důležitým tématům proto patřilo archeologické svědectví o počáteční urbanizaci dané části městského jádra. and The Minorite Monastery in Most. An archaeological and building history study of the Minorite grounds in Most took place in 1971–1976 due to the liquidation of the notable historic town. The study focussed on learning about the development of the church and the reclusion of the Most Minorites in the 13th-14th centuries, and on unravelling the position of their convent within the town organism. The convent stood approximately in the town centre; archaeological testaments on the beginnings of urbanisation in the given town centre are therefore of utmost importance.
Článek předkládá nástin dějin bádání o oppidech a urbanizačních procesech v době laténské ve střední Evropě. Autor poukazuje na skutečnost, že interpretace oppid jakožto měst vznikla již na počátku 20. stol., kdy kromě několika málo oppid nebyla jiná laténská sídliště vůbec známa. Dnes tato interpretace neodpovídá stavu poznání laténské sídlištní struktury. Významnou roli v urbanizačním procesu zaujímají nedávno objevená neopevněná výrobní a distribuční centra a centra typu Němčice-Roseldorf, v nichž lze spatřovat počátky urbanizace střední Evropy v době laténské. Oppidům je naproti tomu přisouzena především obranná a prestižní úloha. and The article offers an outline of the history of research into oppida and urbanisation processes of the La Tène period in Central Europe. The author addresses the fact that the interpretation of oppida as towns came about at the beginning of the 20th century when, besides a few oppida, no other La Tène settlements were known at all. Today this interpretation does not correspond with what we know regarding the La Tène settlement structure. Recently discovered unfortified production and distribution centres and centres of Němčice-Roseldorf type play a significant role in the urbanisation process, in which we are able to see the beginnings of urbanisation of Central Europe during the La Tène period. As opposed to these, the oppida are attributed tasks primarily of a defensive and prestigious nature.
Příspěvek se zabývá strukturálními změnami osídlení 13. stol. ve středním Pojizeří. Prvé písemné doklady o tomto regionu začínají ve 12. stol., kdy se stal významnou součástí majetkové domény Markvarticů, jednoho z předních šlechtických rodů. Až do 13. stol. se moc přemyslovského státu v Pojizeří opírala o hrad v Mladé Boleslavi. V poslední třetině 13. stol. ale vznikla nová síť mocenských center a význam Mladé Boleslavi klesl. Ve zjevné shodě se zájmy krále ovládli střední Pojizeří Markvarticové, postupně rozdělení do několika větví. Hlavní téma příspěvku se soustřeďuje na okolí města Turnova, který se stal jedním z regionálních hospodářských center. Do doby utváření tohoto poddanského městečka ve 2. pol. 13. a v počátcích 14. stol. spadaly i počátky několika blízkých hradů. and The study looks at the structural changes of settlement in the central Jizera River region (northern Bohemia) during the 13th century. The first written records of this region date to the 12th century, when it became an important holding of the Markvartici, one of leading aristocratic kin-groups in Bohemia. Until the 13th century, the power of the Přemyslid state in the Jizera River region had rested in the castle in Mladá Boleslav. The last third of the 13th century, however, saw the establishment of a new network of power centres, causing Mladá Boleslav to wane in former significance. In apparent accord with the interests of the king, control over the central Jizera River region was maintained by the Markvartici kin-group, which eventually split into several branches. The main focus of the work is on the area surrounding the town of Turnov, which grew into one of the region’s centres of economic activity. The beginnings of several nearby castles also fall within the era of the founding of this territorial town in the second half of the 13th and early 14th centuries.
Identifying patterns with sufficient predictive power is a constant challenge for ecologists to address ecological problems related to species conservation, pollution or infectious disease control. During the last years, the amounts of parasitological studies in this sense increased, but they are still scarce in urban environments. The main aim of this study was to investigate if the helminth communities of urban rodents are structured within host assembly (compound community) or they are a result of random events occurring at each individual host scale (infracommunity). A total of 203 rodents belonging to four species, Rattus rattus (Linnaeus), Rattus norvegicus (Berkenhout), Mus musculus Linnaeus and the native Oligoryzomys flavescens (Waterhouse) and captured in different landscape units of the City of Buenos Aires (industrial-residential neighbourhoods, shantytowns and parklands) were analysed. The results showed that infracommunities could be grouped according to composition and relative abundances and that they respond to the structure of the host community. Thus, the component communities defined in this study could be identified as subsets of the compound community (rodent assemblage) and infracommunities (each host) as random samples within each one. Quantitative differences among component communities were denoted by comparing the infection levels of helminths described as central species. Therefore, infracommunities of R. norvegicus and O. flavescens were the most predictable because of the high abundance of the nematodes Heterakis spumosa Schneider, 1866 and Nippostrongylus brasiliensis (Travassos, 1914), and Stilestrongylus flavescens (Sutton et Durette-Desset, 1991), respectively. Several mechanisms contribute to complexity of the structure of parasite communities, where specific parasites, definitive and intermediate hosts, and environmental and anthropogenic factors all play a role in the dynamics of the compound community., Diego Hancke, Olga Virginia Suárez., and Obsahuje bibliografii