The physiology and ecology of planktonic organisms are influenced by the concentration, chemical speciation and resulting bioavailability of some trace metals. The determination of the elemental structure of phytoplankton is important for interpretation of physiological and functional states of coastal ecosystems. The present study is focused on the structure and elemental composition of the phytoplankton assemblages from the different coastal zones by instrumental neutron activation analysis (INAA), scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS). For the first time these complementary techniques were simultaneously applied to study the Black Sea phytoplankton. The concentrations of 45 elements in the coastal phytoplankton communities used as bioindicator of inorganic contamination of the Black Sea coastal area near Sevastopol, Ukraine, were determined. Phytoplankton samples were collected by total tows of the plankton net with 35 μm pore size at 3 stations situated in polluted and relatively pristine water areas of the Sevastopol coastal zone during autumn period of the phytoplankton growth. The concentration of Mg, Al, Sc, Ti, V, Mn, As, Rb, Ba, Th and Fe, Cr increases exponentially from relatively pristine station to more polluted station and 10-times and 3-times greater, respectively, in the phytoplankton of the Sevastopol Bay. The rare-earth elements have relatively the same concentration values less than 1 μg/g and tend to accumulate in the phytoplankton from the polluted station in the Sevastopol Bay. The obtained results are in a good agreement with the elemental concentration data in the oceanic plankton, plankton communities from the White Sea and the Black Sea. Using energy-dispersive X-ray spectrometry the mineral particles of unknown origin and impurities of copper (0.42% by weight) in the phytoplankton at the polluted station and zinc (0.57% by weight) at the relatively pristine station were determined. * Corresponding author. P. S. Nekhoroshkov et al.324

Abstract:For the first time the concentration of 26 macro-and microelements (Na,

Several candidates for antihelium events have been found in the AMS-02 experiment. They cannot be created by natural astrophysical sources and, if confirmed, imply the existence of antimatter stars in our galaxy. This immediately reduces the class of inflationary models with baryosynthesis to those that can provide the creation of an antimatter domain of surviving size together with the general baryon asymmetry of the Universe. To confront the future results of experimental searches for cosmic antihelium with predictions of this hypothesis, we develop numerical studies of the creation and propagation of antihelium flux from antimatter globular clusters in the Galaxy. This article presents the results of such a simulation: a function of the magnetic cut-off for the penetration of antihelium nuclei into the Galaxy disk and an estimate of the energy range in which the search and detection of antihelium is most optimal.

The levels and compartmentalization of Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Mo, Sb, I, Cs, Ba, La, Ce, Sm, Eu, Tb, Hf, Ta, Au, Th, and U in Phragmites australis (Cav.) Trin. ex Steud., Carex conescens L. and Cladophora sericea (Hudson) Kutzing from the Caucasian coast of the Black Sea-Anapa recreational region was investigated by Neutron Activation Analysis. The study touches upon subject of the sediment-to-plant and root-to-leaf elemental transfer as well as of the influence of anthropogenic pollution on wetland ecosystems in zone of resort. The content of the majority of considered elements was found higher in the belowground organs of P. australis than in the aboveground tissues while a reverse regularity was evidenced for C. conescens. The levels of elements decrease from bottom sediments to aquatic plants with the notable exception of the halogens Cl, Br and I that presented 5 to 100 fold higher content in plants than in sediments. The increased levels of As, Mo, and Sb in some soil and sediment samples most probably indicate the anthropogenic pollution. It recommends them for a continuous monitoring of the same area.

The concentrations of 29 elements in the soft tissues and of 24 elements in the shells of mussels (Mytilus galloprovincialis) collected in one selected recreational and two relatively polluted zones were determined and are presented. The high levels of elements in the mussels from a relatively polluted zone of the harbor (Kamyshovaya Bay) could be associated with phytoplankton, terrigenous matter and anthropogenic sources, but did not harm the mussel population, according to the calculated average condition factors. The low levels of the studied elements and condition factors in the mussels from another harbor (Sevastopol Bay) can be explained by the high circulation and influence of submarine desalinated waters in this zone. The mussels from a recreational site in the South coast of Crimea (Foros) showed high levels of the examined elements, commonly due to the coastal weathering of typical local rocks. The found levels of the radionuclides 40K, 137Cs, 232Th, 226Ra and 235U in mussel soft tissues were below the minimum detectable concentrations. The calculated enrichment factors and soft tissue/shells ratios demonstrated differences between groups of elements among the studied sites.