Biomagnification of mercury in trophic relation of Great Cormorant (Phalacrocorax carbo) and fish in the Vistula Lagoon, Poland

Total mercury (Hg) concentrations were determined by CV-AAS in selected tissues (liver, kidney, and muscle) of the Great Cormorant and some fish species (herring, ruffe, European smelt, tench, roach, Crucian carp, and Prussian carp) from the Vistula Lagoon ecosystem (Poland). Significant correlations between Hg concentrations in the kidneys and muscle of cormorants (U test, p?<?0.05) were found; levels of the metal were highest in the birds?? liver and kidneys. Total Hg concentrations in the fish decreased in the following order: roach > Prussian carp > Crucian carp > tench > European smelt > ruffe > herring. The biomagnification factor of Hg for the cormorant relative to the fish decreased in the following sequence: herring > ruffe > European smelt > tench > Crucian carp > roach = Prussian carp. It was significantly greater than unity, especially for the cormorant?Cherring trophic relationship. This implies that Hg is biomagnified in the cormorant in relation to its prey.     

Variable-Thermoinsulation Garments With a Microprocessor Temperature Controller

This paper presents the concept of active variable thermoinsulation clothing for users working in low temperatures. Those garments contain heating inserts regulated by a microprocessor temperature controller. This paper also presents the results of tests carried out on the newly designed garments.     

Sperm competition in the mite Caloglyphus berlesei

Summary The sperm utilisation pattern of C. berlesei was investigated using the sterile male method. The last male to mate with a female fertilised most of her eggs. In experiments where females mated with two virgin males, second males fertilised on average 86% of eggs when second matings took place immediately after the first. Last male sperm priority was also confirmed in experiments where females mated sequentially with three males. The proportion of eggs fertilised by the second male decreased to 71% and 56% when the interval between matings was 2 and 6 h, respectively. Males that had opportunities to mate prior to experiments copulated for a shorter time than virgin males, and second males fertilised on average 74% eggs.     

Solid State Reactions of Potato Starch with Urea and Biuret

Reaction of granular potato starch with urea and biuret resulted in the formation of products, which were soluble neither in cold nor boiling water. The net reaction was a monosubstitution of the hydrogen atom in one hydroxyl group in each D-glucose unit of starch with the either CO–NH₂ or CO–NH–CO–NH₂ moiety, respectively. Properties of the products, particularly these with urea, depended on the mode of reaction. Reactions were carried out in the microwave oven as well as with convection heating. The products retained the granular form of starch but a vast majority of granules were damaged. -Amylolysis of those materials revealed that their susceptibility to the enzyme increasing in the order: starch-amylolysis with simultaneous insolubility in water make these products suitable as ruminant fodder and, eventually, biodegradable material.     

Overexpression of LCT1 in tobacco enhances the protective action of calcium against cadmium toxicity

Wheat cDNA LCT1, a nonspecific transporter for Ca2+, Cd2+, Na+ and K+, was overexpressed in tobacco. Transformants were tested for their sensitivity to a range of Ca2+-concentrations [0.01-10 mM Ca(NO3)2] with or without the presence of 0.05 mM Cd(NO3)2. Calcium and cadmium accumulation was also determined. LCT1-transformed plants expressed a phenotype distinct from controls only under conditions of low calcium (0.01-1 mM Ca2+). They grew significantly better and had slightly higher shoot calcium concentration. Transformants subjected to 0.05 mM Cd(NO3)2 in the presence of 1 mM Ca2+ displayed a substantially higher level of tolerance to cadmium and accumulated less Cd in roots. These results are the first to demonstrate the involvement of LCT1 in calcium acquisition and in the regulation of amelioration of Cd-toxicity by calcium.     

Determination of elemental carbon emission

The studies on elemental carbon content in the atmospheric air, performed at the air monitoring station in Katowice (Poland), have revealed violations of allowable maximum average annual and diurnal concentrations. Elemental carbon is introduced into the atmosphere mainly as soot generated from combustion processes. This work presents the determination of elemental carbon in emission generated from coal combustion processes.     

The effect of mating frequency on female lifetime fecundity in the bulb mite, <Emphasis Type="Italic">Rhizoglyphus robini </Emphasis>(Acari: Acaridae)

We investigated the influence of mating frequency on lifetime reproductive success in females of the bulb mite, Rhizoglyphus robini. This species is highly promiscuous, and its colonial lifestyle promotes mating frequencies of at least several times a day. We manipulated mating frequencies either by keeping females continuously in the presence of a male, with males replaced every second day, or by exposing females to a new male for 4 h every second day (4 h is enough for a male to complete at least one copulation). We used males that were isolated from females either for 2 days, and thus had large reserves of sperm and seminal fluid, or for 2 h. We found that females with continuous access to a male had lower lifetime egg output than those exposed to males intermittently. This effect was mediated through decreased fecundity and not longevity. Male mating history had no significant effect on female fecundity or longevity. These results confirm that mating frequencies observed in bulb mite colonies exceed those necessary for sperm replenishment, and suggests that frequent mating is costly to females. We discuss possible explanations for the maintenance of mating frequencies that are detrimental to females.     

Microbial Cretaceous park: biodiversity of microbial fossils entrapped in amber

Microorganisms are the most ancient cells on this planet and they include key phyla for understanding cell evolution and Earth history, but, unfortunately, their microbial records are scarce. Here, we present a critical review of fossilized prokaryotic and eukaryotic microorganisms entrapped in Cretaceous ambers (but not exclusively from this geological period) obtained from deposits worldwide. Microbiota in ambers are rather diverse and include bacteria, fungi, and protists. We comment on the most important microbial records from the last 25 years, although it is not an exhaustive bibliographic compilation. The most frequently reported eukaryotic microfossils are shells of amoebae and protists with a cell wall or a complex cortex. Likewise, diverse dormant stages (palmeloid forms, resting cysts, spores, etc.) are abundant in ambers. Besides, viral and protist pathogens have been identified inside insects entrapped in amber. The situation regarding filamentous bacteria and fungi is quite confusing because in some cases, the same record was identified consecutively as a member of these phylogenetically distant groups. To avoid these identification errors in the future, we propose to apply a more resolute microscopic and analytical method in amber studies. Also, we discuss the most recent findings about ancient DNA repair and bacterial survival in remote substrates, which support the real possibility of ancient DNA amplification and bacterial resuscitation from Cretaceous resins.     

Distribution of mercury in different environmental compartments in the aquatic ecosystem of the coastal zone of the Southern Baltic Sea

The aim of this study was to characterize mercury (Hg) contamination in the coastal waters of the Southern Baltic Sea, and to investigate transformations of Hg in the initial links of the marine food chain. Concentrations of Hg in water, particulate matter, plankton and macrophytes at various stations in the coastal zone (a bay with restricted water exchange, near an industrial city, river mouths, and the open sea) were measured in 2006–2008. Hg concentrations observed in the Southern Baltic varied greatly, showing the highest average values in all environmental compartments near the river mouths. In shallow, sheltered parts of the gulf, where water exchange is restricted, Hg concentrations in the water and in macrophytes were elevated relative to those in the coastal zone of the deeper part of the bay and in the open Baltic. Distance to the river mouth, terrestrial runoff, and quantity and quality of organic matter were more important than seasonal variations in controlling Hg and HgSPM concentrations in water samples. Mercury concentrations in the surface microlayer at the air/sea interface were over 10 times higher than those in the bulk surface water. Concentrations of Hg in macrophytes in the winter were significantly higher than those in the warm seasons (spring, summer, autumn). This was probably the combined effect of higher availability of Hg in porewaters and leaf growth inhibition.     

Rapana venosa as a bioindicator of environmental pollution

The aim of this investigation was to examine biochemical differences in the gastropod Rapana venosa (R. venosa) from polluted (RvP) and nonpolluted (RvN) sites of the Black Sea's Bulgarian coast that may serve as bioindicators of environmental quality. Mussels Mytilus galloprovincialis (MMg) were collected from polluted (MMgP) and nonpolluted (MMgN) sites at the same time for comparison. Bioactive compounds and the antioxidant activity of dry matter (DM) methanol extracts from RvP and RvN were determined. Three-dimensional fluorometry (3D-FL) and Fourier transform infrared (FTIR) analyses were used to evaluate polyphenols and proteins. DM methanol extracts from RvP, and to lesser extent RvN, showed high amounts of total phenolics (23.22±2.9 and 15.60±1.8 mg GAE · g^?1 DW) and exhibited high levels of antioxidant activity in some radical scavenging assays (μ MTE · g^?1 DW): 56.38±5.2 and 33.79±3.3 by 2,2azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diamonium salt (ABTS·⁺); 54.79±5.6 and 33.7±2.6 by cupric reducing antioxidant capacity (CUPRAC); 62.34±6.8 and 30.31±3.9 by the 1diphenyl-2-picrylhydrazyl method (DPPH). A correlation in the above indices was found between R. venosa and M. galloprovincialis, but all results were relatively higher for M. galloprovincialis than for R. venosa. The obtained indices of R. venosa may serve as a bioindicator of environmental ecological quality.