First report of Navicula jakovljevicii Hustedt (Bacillariophyta) from Hungary: distribution, comparative morphology and a related species

In Hungary Navicula jakovljevicii was firstly recorded in biofilm of Elodea nuttallii in 2005 in an oxbow of the catchment area of the River Danube. Subsequently, in 2006, N. jakovljevicii was also found in the same oxbow on reed stems as well. In the following years it appeared in another oxbow, suggesting an expanding distribution in the tributaries of the Danube in Hungary. The Hungarian population can be characterised as having mixed morphological features in comparison with other known N. jakovljevicii populations of Europe. When the morphological study was expanded, a similar, but \u27giant form\u27 was detected in fossil material. We found similarities and a possible connection between N. jakovljevicii and Navicula lucida, a diatom taxon described from a Neogene deposit in the Carpathian Basin. Despite the morphological similarities in the shape, apices, striae pattern and raphe structure of these two species, there are significant differences in valve dimensions: the valves of N. lucida are larger and more heavily silicified than N. jakovljevicii

A város peremén. (A rozsdaövezet múltja és jelene Budapesten) = At the outskirts of the city. (Past and Present of the brownfield area in Budapest)

A barnamezős térség - ahol korábban elsősorban ipari tevékenység folyt - felméréseink szerint 68-70 km2-t foglal el Budapest közigazgatási területéből. Kutatásaink négy területre koncentrálódtak: bemutattuk az ipar mintegy 160 éves történetét, az ipari múlt örökségét (a környezeti szennyezettséget, az alacsony hatásfokú földhasználatot, a megüresedett területeket, a zavaros tulajdonviszonyokat, stb.), a korábbi funkciók spontán változásait (az új bevásárló központok, technológiai és ipari parkok megjelenését, az ipari műemlékek más célú - kulturális, lakás, stb. - felhasználását), és végül, a barnamezős területek rehabilitációjával foglalkozó, reménykeltő terveket. A barnamező megújítására irányuló erőfeszítések előtt hatalmas a kihívás. Mindazonáltal, ez a térség Budapest fejlesztésének fontos gazdasági tartaléka. | The brownfield belt of the Hungarian capital, where once large industrial production sites were located, comprises an area of 68-70 square kilometres. Our researches have been concentrated on four fields: to present the 160-year-long history of Budapest as an industrial city; the legacy of the industrial past (environmental pollution, the uneffected land use, empty areas, a messy ownership, etc.); the spontaneous changes of the former fuctions (appearence of new shopping centres, technological and industrial parks, industrial monuments used for cultural events, housing, etc.); and finally the promising plans that deal with the brownfields of Budapest. Any effort of brownfield rehabilitation in Budapest faces formidable challenges. However, this area could be promising for metropolitan development and become an important economic factor in the future

Is 4C+29.48 a γ-ray source?

The Fermi Large Area Telescope revealed that the extragalactic gamma-ray sky is dominated by blazars, active galactic nuclei (AGN) whose jet is seen at very small angle to the line of sight. To associate and then classify the gamma-ray sources, data have been collected from lower frequency surveys and observations. The gamma-ray source 3FGL J1323.0+2942 is associated with the radio source 4C+29.48 and classified as a blazar of unknown type, lacking optical spectrum and redshift. The higher-resolution radio data showed that 4C+29.48 comprises three bright radio-emitting features located within a ~1'-diameter area. We (re-)analyzed archival Very Large Array and unpublished very long baseline interferometry (VLBI) observations conducted by the Very Long Baseline Array and the European VLBI Network of 4C+29.48. We also collected data form optical, infrared and X-ray surveys. The northernmost complex of 4C+29.48 contains a blazar with a high brightness temperature compact core and a steep-spectrum jet feature. The blazar is positionally coincident with an optical source at a redshift of 1.142. Its mid-infrared colors also support its association with a gamma-ray emitting blazar. The two other radio complexes have steep radio spectra and do not have optical or infrared counterparts in currently available surveys. Based on the radio morphology, they are unlikely to be related to the blazar. We discuss the possibilities whether the two radio features are lobes of a radio galaxy, or gravitationally lensed images of a background source. We propose to associate 3FGL J1323.0+2942 in subsequent versions of the Fermi catalog with the blazar residing in northernmost complex. We suggest naming this source J1323+2941A to avoid misinterpretation arising from the fact that the coordinates of the currently listed radio counterpart 4C+29.48 is closer to a most probably unrelated radio source. (abridged)Comment: 10 pages, 3 tables, 12 figures; accepted for publication in Astronomy & Astrophysic

Halophilic diatom taxa are sensitive indicators of even short term changes in lowland lotic systems

The occurrence and spread of halophilic diatom taxa in freshwater lotic ecosystems are influenced both by natural processes and anthropogenic pollution. Diatom assemblages were regularly monitored in lowland lotic systems in Hungary (Central Europe) during the unusually dry year of 2012. Highly pronounced changes in diatom composition were observed from spring to autumn. Halophilic taxa (especially Nitzschia sensu lato species) appeared in the dry autumn. In addition, the total relative abundances of halophilic species also increased up to autumn. Abundance of Nitzschia cf. lorenziana and Nitzschia tryblionella showed a positive correlation with chloride and phosphate concentration, while that of other taxa like Tryblionella apiculata or Tryblionella calida showed a positive correlation with the concentration of nitrate. Our fi ndings clearly demonstrated that these halophilic and mesohalophilic diatom taxa were sensitive indicators of even short-term changes in lowland lotic ecosystems, such as the increasing salt concentration from spring to autumn caused by the lack of rainfall and/or environmental loads