High-throughput discrimination of bacteria isolated from Astacus astacus and A. leptodactylus

Bacterial diseases and pathogens of crayfish are common, widespread, and occasionally causing serious mortalities. In order to take rapid measures for correct treatment of crayfish diseases, the turnover time and accuracy in bacterial identification is an issue. Bacteria isolated from tissues of apparently healthy Astacus astacus and A. leptodactylus were identified by the commercial phenotypic tests (API 20E) and by the matrix assisted laser induced desorption ionization connected to the time of flight mass spectrometry (MALDI-TOF MS). For Gram-negative rods, API 20E resulted in fewer species identifications than MALDI-TOF MS (5.2% versus 52.61%). The most frequently identified genus from A. astacus and A. leptodactylus was Pseudomonas spp.: API 20E (47.82%) and MALDI-TOF MS (52.17%). Both systems identified 60.86% of total isolates identically to the genus. Hafnia alvei was the only isolate for which API 20E and MALDI-TOF MS had a concordant reading to the species. MALDI-TOF MS proved to be a powerful, low-cost, rapid tool in bacterial genus identification. This is the first report of a direct comparison between the two systems for the identification of bacteria in crayfish, and also the first report on using MALDI-TOF MS for discrimination of freshwater crayfish bacterial isolates

Kavezno izlaganje lubina (Dicentrarchus labrax) u procjeni genotoksičnog utjecaja onečišćenja

Genotoxic effects are often the earliest signs of pollution-related environmental disturbance. In this study, we used the comet assay and micronucleus test to assess DNA damage in the erythrocytes of the European sea bass (Dicentrarchus labrax) exposed to environmental pollution in situ. Fish were collected from a fi sh farm in the Trogir Bay and their cages placed at an unpolluted reference site Šolta (Nečujam Bay) and a polluted site Vranjic (Kaštela Bay) for four weeks. A group of fi sh which remained at the fi sh farm Trogir Bay were used as the second control group. Fish exposed at the Vranjic site showed a signifi cantly higher erythrocyte DNA damage, measured by the comet assay, than either control group. Micronucleus induction showed a similar gradient of DNA damage, but did not reach statistical signifi cance. Our results show that cage exposure of a marine fi sh D. labrax can be useful in environmental biomonitoring and confi rm the comet assay as a suitable tool for detecting pollution-related genotoxicity.Genotoksični učinak često je jedan od najranijih pokazatelja štetnog djelovanja onečišćenja okoliša. U ovom radu procijenjeno je oštećenje DNA u eritrocitima lubina (Dicentrarchus labrax) izloženima okolišnom onečišćenju s pomoću komet-testa i mikronukleus-testa. Lubini su prikupljeni na ribogojilištu i kavezno izloženi u periodu od četiri tjedna na dvije postaje različitog stupnja onečišćenja na jadranskoj obali: na kontrolnoj postaji Šolta (zaljev Nečujam) i na onečišćenoj postaji Vranjic (Kaštelanski zaljev). Zasebna skupina lubina skupljena na ribogojilištu poslužila je kao druga kontrola. Rezultati komet-testa pokazali su statistički značajan porast oštećenja DNA na postaji Vranjic u usporedbi s obje kontrolne postaje. Rezultati mikronukleus-testa pokazali su sličan gradijent onečišćenja, iako nisu dosegli statističku značajnost. Ovi rezultati upućuju na primjenjivost kaveznog izlaganja lubina D. labrax u biomonitoringu vodenog okoliša te potvrđuju korisnost komet-testa kao prikladne metode za detekciju genotoksičnog utjecaja onečišćenja

Hif1a inactivation rescues photoreceptor degeneration induced by a chronic hypoxia-like stress

Reduced choroidal blood flow and tissue changes in the ageing human eye impair oxygen delivery to photoreceptors and the retinal pigment epithelium. As a consequence, mild but chronic hypoxia may develop and disturb cell metabolism, function and ultimately survival, potentially contributing to retinal pathologies such as age-related macular degeneration (AMD). Here, we show that several hypoxia-inducible genes were expressed at higher levels in the aged human retina suggesting increased activity of hypoxia-inducible transcription factors (HIFs) during the physiological ageing process. To model chronically elevated HIF activity and investigate ensuing consequences for photoreceptors, we generated mice lacking von Hippel Lindau (VHL) protein in rods. This activated HIF transcription factors and led to a slowly progressing retinal degeneration in the ageing mouse retina. Importantly, this process depended mainly on HIF1 with only a minor contribution of HIF2. A gene therapy approach using AAV-mediated RNA interference through an anti-Hif1a shRNA significantly mitigated the degeneration suggesting a potential intervention strategy that may be applicable to human patients

GENOTOXICITY OF SHALLOW WATERS NEAR THE BRAZILIAN ANTARCTIC STATION "COMANDANTE FERRAZ" (EACF), ADMIRALTY BAY, KING GEORGE ISLAND, ANTARCTICA

Series of biomonitoring surveys were undertaken weekly in February 2012 to investigate the genotoxicity of the shallow waters around the Brazilian Antarctic Station "Comandante Ferraz" (EACF). The comet assay was applied to assess the damage to the DNA of hemocytes of the crustacean amphipods Gondogeneia antarctica collected from shallow waters near the Fuel Tanks (FT) and Sewage Treatment Outflow (STO) of the research station, and compare it to the DNA damage of animals from Punta Plaza (PPL) and Yellow Point (YP), natural sites far from the EACF defined as experimental controls. The damage to the DNA of hemocytes of G. antarctica was not significantly different between sites in the biomonitoring surveys I and II. In survey III, the damage to the DNA of animals captured in shallow waters near the Fuel Tanks (FT) and Sewage Treatment Outflow (STO) was significantly higher than that of the control site of Punta Plaza (PPL). In biomonitoring survey IV, a significant difference was detected only between the FT and PPL sites. Results demonstrated that the shallow waters in front of the station may be genotoxic and that the comet assay and hemocytes of G. antarctica are useful tools for assessing genotoxicity in biomonitoring studies of Antarctic marine coastal habitats

Bridges of Kaliningrad in the past and today

U ovom radu su najprije dane stvarne situacije oko Kalingradskih mostova kroz povijest. Nakon toga je dano Eulerovo rješenje problema, Eulerov teorem za opći slučaj te Fleuryjev algoritam.In this paper the history of Kaliningrad\u27s bridges is described first. After that Euler\u27s solution of the problem is given, and then Euler\u27s theorem and Fleury\u27s algorithm

Interference of solvent impurities in pesticide residues analysis by gas chromatography

Uobičajena analiza uzoraka mlijeka u prahu (koja se provodi u proizvodnji dječje hrane) ponekad vodi do previsokih rezultata za sadržaj nekih pesticida. Proučavan je utjecaj za sada još nepoznatih nečistoća otapala na točnost rezultata slijedećim metodama: a) promjena uvjeta pri radu plinskom kromatografijom, b) primjena vrlo tankog sloja (tanji od 0,25 mm) pri radu tankoslojnom kromatografijom. c) dodavanje poznatih količina aktivne tvari, d) kombinacija plinske kromatografije i spektroskopije masa. Iako kombinacija plinske kromatografije i spektroskopije masa nije potpuno uspjela, dokazana je da je koncentracija aldrina i α-HCH kod većine uzoraka niža nego što je dobiveno obično upotrebljavanim metodama.The analysis of samples of milk powder (conventionally used in baby foods manufacture control) can give essentially higher results for the content of some pesticides. The influence of undefined impurities (introduced with solvents) on samples was studied by the following methods: a) variations in operating conditions of GLC, b) application of a very thin layer in TLC, c) addition of known amounts of active principle to the sample, d) combination of GLC and mass spectroscopy. Although the isolation and determination of interfering components by the use of a combination of GLC and mass spectroscopy were not successful, it was proved that the concentrations of aldrin and α-HCH in almost all samples are lower than the values suggested by conventional analytical procedures

Update on the distribution of freshwater crayfish in Croatia

Four indigenous European and two non-indigenous American freshwater crayfish species inhabit Croatian freshwater habitats. Generally, the noble crayfish (Astacus astacus), the narrow-clawed crayfish (Astacus leptodactylus) and the stone crayfish (Austropotamobius torrentium) are distributed in the water bodies of the Black Sea drainage while the white-clawed crayfish (Austropotamobius pallipes) inhabits rivers of the Adriatic Sea drainage. However, a few records of the noble and the stone crayfish populations in the Adriatic Sea drainage exist. Non-indigenous species the signal crayfish (Pacifastacus leniusculus) and the spiny-cheek crayfish (Orconectes limosus) are distributed in northern Croatia, in the water bodies of the Black Sea drainage. Recently, the distribution of Croatian crayfish populations has been studied more intensely within the frame of Natura 2000. In this paper we present results of field work conducted from 2005 till 2010, and compare them with previous data. Approximately 520 sites were investigated. Results indicate that non-indigenous crayfish are spreading and displacing the noble and the narrow-clawed crayfish. No mass mortalities in the contact zone have been reported. This survey also revealed the spread of the narrow-clawed crayfish westwards and southwards displacing the noble and the stone crayfish from their habitats. The stone and the white-clawed crayfish populations have undergone the biggest decline in numbers. The main reasons for this are disturbance of their habitats and intensive droughts which have been pronounced of late. Collected data are helpful as a starting point for development of management strategies by state institutions dealing with protection of endangered crayfish species

ANNUAL ACTIVITY OF THE NOBLE CRAYFISH (ASTACUS ASTACUS) IN THE ORLJAVA RIVER (CROATIA)

We studied the annual activity of the noble crayfish (Astacus astacus) at three sites along the Orljava River, in the continental part of Croatia, between August 2003 and September 2004. Each site represented the typical characteristics of the upper, middle and lower section of the river (5, 24 and 37 km from the spring, respectively). The biggest population size was recorded on the most upstream site, with greatest structural variability of bottom, high biotic index, and the lowest mean water temperature. Males dominated in catch during the whole research period (total sex ratio was 1.77 males: 1 female). The number of caught crayfish fluctuated during the year and their activity was positively correlated with the water temperature. The crayfish catch within the two downstream sites was dramatically lower in the autumn 2004 then the year before. No obvious reason could be found; therefore we concluded that this was probably result of natural fluctuations in population. Males were significantly longer than females on all three sites. Males and females had similar percentages of injuries, mainly on claws and antennae. Crayfish were active during the whole year, even when water temperature was just 1°C. Phases of life cycle (moulting, active cement glands, mating, hatchlings) occurred a month later in our population than in the Northern Europe populations, probably as a consequence of differences in the climate