BIOAVAILABLE STRONTIUM ISOTOPE BASELINE FOR THE NOVOTEMIRSKIY BRONZE AGE MINE

Для оценки мобильности и идентификации происхождения древних популяций требуется проводить сравнение их изотопных отношений 87Sr/86Sr с локальной базовой (фоновой) линией биодоступного стронция, характерной для каждого конкретного местонахождения или потенциального района происхождения индивида или артефакта. В данной работе на примере древнего рудника Новотемирский (Южный Урал) эпохи бронзы проведена оценка такой базовой линии. Изотопные отношения 87Sr/86Sr определены в поверхностной и подземной воде, коренной породе (серпентинит), глине из стенки шахты, кости светлого хоря, а также в траве и раковине двустворки с берега озера. Наименьшим разбросом изотопных отношений стронция друг относительно друга обладают поверхностная и подземная вода, раковина и трава, что позволяет использовать их для определения объединенной базовой линии биодоступного стронция. Мульти-прокси (поверхностная и подземная вода, травы и раковина двустворки) локальная базовая линия биодоступного стронция для района древнего рудника Новотемирский (Южный Урал) может быть представлена в виде диапазона 0,7096 ± 0,0003 (2σ, n = 5). To assess the mobility and provenance of ancient populations, it is necessary to compare their 87Sr/86Sr isotopic ratios with the local bioavailable strontium baseline (background), characteristic of each specific location or potential provenance region of an individual or artifact. Its definition requires a comprehensive approach to the analysis of heterogeneous samples («proxies») characterizing the ecosystem of the archaeological site under study, the identification of the most suitable proxies, as well as the unification and standardization of the sampling and analytic protocols. A pilot study is presented devoted the definition of the local range of bioavailable strontium by the example of the Novotemirskiy Bronze Age mine (Southern Urals). 87Sr/86Sr isotope ratios were determined in surface and underground water, bedrock (serpentinite), clay from the mine wall, and steppe polecat's bone, as well as in grass and a bivalve shell from the lake. The lowest range of strontium isotope ratios relative to each other is characteristic of surface and groundwater, shell and grass, which allows them to be used to determine the combined baseline of bioavailable strontium. Multi-proxy (surface and underground water, grass and a bivalve shell) local bioavailable strontium baseline for the Novotemirskiy ancient mine (Southern Urals) is 0,7096 ± 0,0003 (2σ, n = 5).

Biodiversity of Bivalves in South Bintan Waters, Riau Archipelago, Indonesia

Bivalves is the second most diverse group of molluscs after gastropods, they are also one of the most important members in marine ecosystems. Their taxonomic classifications are based on their morphology which tend to represent adaptation responses to ecology. The samples of bivalves examined in this study were taken in the South Bintan waters by Marine Geological Research and Development Center, Bandung. Identification of the bivalves shell samples was with the aid of a microscope and NIS-Elements software and identified using an identification book. There were 34 species of bivalves found in South Bintan Waters belong to 14 families. The highest abundance was in Station 1 the location close to the overflow of the river and a harbor (1162.5 ind.m-2) and the lowest was in Station 10 the location Station 10 the location close to a small island which is usually used as a tourist spot (62.5 ind.m-2). Their diversity and eveness index were included in the medium category with H’ value of 0.58-4.12 and e value of 0.11-0.89 respectively. There was species dominance in Station 3 (Liralucina lyngei of Lucinidae) and 10 (Cardites bicolor of Carditidae) but not in other stations. Both species was the most frequent species. Bivalves in South Bintan waters showed many different morphologies which represented their adaptation. The bivalve shells found were of different morphology. There are several forms of bivalve shell morphology that have shape round like species Chama japonica, triangular like species Gemma gemma, fragile like species Dendostrea rosacea. The shell decorations found in the bintan Bivalves samples are Spinose, Commarginally, Commarginally and radially ribbed. The hinge teeth are heteroodont, isodont, and schizodont.

Substantiation of the parameters of the working bodies of undulating disks of soil-cultivating harrows with a bionic approach

The article presents the methods and results of the bionic approach in the system of agricultural mechanics, which made it possible to theoretically substantiate the main parameters of the model of the working organs of wavy discs using two bionic prototypes - the burrowing leg and radial ribs of the bivalve shell of the edible heart-shaped mollusk (Cerastoderma edule) and the burrowing leg of the dung beetle common (Geotrupes stercorarius). The model of the working bodies of undulating disks allows one to preserve the anti-erosion resistance of the soil in the upper cultivated layer in order to preserve its structure and stubble background during non-moldboard tillage in the soil-protective agriculture system for the technologies “Verti-till” and “Strip-till”. The results of theoretical studies on the substantiation of the design parameters of the working bodies of wavy discs for surface tillage are presented.

Conversion of Bivalve Shells to Monocalcium and Tricalcium Phosphates: An Approach to Recycle Seafood Wastes

The search for sustainable resources remains a subject of global interest and the conversion of the abundantly available bivalve shell wastes to advanced materials is an intriguing method. By grinding, calcium carbonate (CaCO3) powder was obtained from each shell of bivalves (cockle, mussel, and oyster) as revealed by FTIR and XRD results. Each individual shell powder was reacted with H3PO4 and H2O to prepare Ca(H2PO4)2·H2O giving an anorthic crystal structure. The calcination of the mixture of each shell powder and its produced Ca(H2PO4)2·H2O, at 900 °C for 3 h, resulted in rhombohedral crystal β-Ca3(PO4)2 powder. The FTIR and XRD data of the CaCO3, Ca(H2PO4)2·H2O, and Ca3(PO4)2 prepared from each shell powder are quite similar, showing no impurities. The thermal behaviors of CaCO3 and Ca(H2PO4)2·H2O produced from each shell were slightly different. However, particle sizes and morphologies of the same products obtained from different shells were slightly different—but those are significantly different for the kind of the obtained products. Overall, the products (CaCO3, Ca(H2PO4)2·H2O, and Ca3(PO4)2) were obtained from the bivalve shell wastes by a rapidly simple, environmentally benign, and low-cost approach, which shows huge potential in many industries providing both economic and ecological benefits.

Daily cyclicity in bivalve shell chemistry: Paleo-weather record or circadian rhythm?

<p>Bivalve shells have a long-standing reputation as archives for high-resolution (seasonal scale) (paleo)climate variability due to their incremental growth, yielding accurate shell chronologies, and their abundance, diversity, and high preservation potential in the fossil record (Schöne and Surge, 2012). Capitalizing on innovations in geochemical techniques, high-resolution sclerochronology can now resolve changes in bivalve shell chemistry beyond the daily resolution (e.g. Sano et al., 2012; Warter et al., 2018). When applied on fossil shells, these ultra-high-resolution records have the potential to bridge the gap between climate and weather reconstructions and yield unprecedented information about bivalve paleobiology, extreme weather events in past climates and even astronomical cycles (Warter and Müller, 2017; de Winter et al., 2020; Yan et al., 2020).</p><p>However, studies of sub-daily scale shell chemistry are almost exclusively limited to giant clams (Tridacna spp.), due to their high growth rates. It is hitherto unknown if and how such diurnal cycles in chemistry differ in other genera across the bivalve clade and/or whether they are exclusive to photosymbiotic clams. In addition, it is not clear whether the daily cycles are formed in response to environmental conditions (e.g. light or temperature sensitivity) or reflect circadian rhythms.</p><p>To answer these questions, we combine ultra-high-resolution (hourly scale) Laser Ablation ICP-MS trace element profiles through shells of various tridacnid species from the tropical Gulf of Aqaba with profiles through the giant scallop (Pecten maximus) from the temperate Atlantic coast of northwestern France. We observe trace element cycles on in the daily frequency domain in both tridacnids and pectinids. This shows that these diurnal cycles are formed regardless of shell mineralogy (aragonite vs. calcite), living environment (tropical inter-tidal vs. temperate sub-tidal) and occur in highly unrelated bivalve taxa. Our data helps the interpretation of similar records from fossil shells in terms of past (extreme) weather events, climate, and shell growth.</p><p> </p><p><strong>References</strong></p><p>de Winter, N. J. et al. Paleoceanography and Paleoclimatology 35, e2019PA003723 (2020).</p><p>Sano, Y. et al. Nature Communications 3, 761 (2012).</p><p>Schöne, B. R. & Surge, D. M. Treatise Online 24, Volume 1, Chapter 14 (2012).</p><p>Warter, V., Erez, J. & Müller, W. Palaeogeography, Palaeoclimatology, Palaeoecology 496, 32–47 (2018).</p><p>Warter, V. & Müller, W. Palaeogeography, Palaeoclimatology, Palaeoecology 465, 362–375 (2017).</p><p>Yan, H. et al. PNAS 117, 7038–7043 (2020).</p>

Crab Diets Differ Between Adjacent Estuaries and Habitats Within a Sheltered Marine Embayment

Portunid crabs contribute to significant commercial and recreational fisheries globally and are commonly fished in estuaries and/or marine embayments, which are amongst the most degraded of all aquatic ecosystems. Portunus armatus were collected seasonally between April and February from five locations across three systems in temperate south-western Australia. The dietary composition of crabs was quantified and compared between two estuaries (Peel-Harvey and Swan-Canning) and a sheltered marine embayment (Cockburn Sound) containing three distinct habitats: shallow seagrass, shallow sand and deep sand. Overall, crabs ingested large volumes of bivalves (both live organisms and dead shell), polychaetes, crustaceans (e.g., amphipods, small decapods), and smaller volumes of teleosts, echinoderms and plant material (seagrass, algae). Analysis of Similarities showed that dietary composition varied significantly among the five locations (two estuaries and three habitats within Cockburn Sound) and seasons, with greater location than seasonal differences in the two estuaries. Diets were most distinct in the Cockburn Sound seagrass due to greater volumes of decapods and teleosts and smaller volumes of bivalve shell consumed in this habitat. Crabs from both estuaries consumed greater quantities of bivalves than those from Cockburn Sound. Seasonal differences in both estuaries were greatest between summer and winter, with a more diverse range of prey and large quantities of bivalves ingested in summer, whereas small bivalves and bivalve shell in the Peel-Harvey and polychaetes and other crustaceans in the Swan-Canning, were consumed in greater quantities in winter. The summer diet in the Peel-Harvey Estuary in the current study was compared to that 20 years previous and with documented change in the benthic macroinvertebrate fauna. Currently, crabs consume smaller volumes of high-calorie prey, i.e., polychaetes, small bivalves and teleosts, and instead ingest greater proportions of calcareous material than previously. This marked shift in dietary composition parallels changes in benthic macroinvertebrates in the Peel-Harvey Estuary. Overall, prey availability appears to be the major factor influencing the spatial and temporal differences in P. armatus diets in these three coastal systems.

Extraction and Characterization of Matrix Protein from Pacific Oyster（Crassostrea gigas）Shell and its Anti-osteoporosis Properties in vitro and in vivo

Matrix protein is a kind of secretory protein that regulates the biomineralization of bivalve shell. In this study, a water-soluble matrix protein (WSMP) from Pacific oysters (Crassostrea gigs) shell was...