The Impact of Sea Ice Loss on Benthic Communities of the Makarov Strait (Northeastern Barents Sea).

The continental shelf of the northeastern Barents Sea is presently experiencing a weak influx of Atlantic water from the west. In recent times, warming in Arctic regions has led to an increase in extended ice-free periods in this area, instead of significantly elevating water temperatures. The implications of this phenomenon on the structure and functioning of benthic communities were investigated during the autumn of 2019 within the Makarov Strait, located in the southwestern part of the St. Anna Trough. The macrozoobenthic communities exhibited a clear connection with the duration of ice-free periods. This variable influenced a vertical carbon flux, which subsequently served as the primary predictor for faunal abundance and diversity, as demonstrated by redundancy and correlation analyses. Two faunal groups were identified, corresponding to short and long open-water periods. Both groups had similar alpha diversity (65 ± 6 and 61 ± 9 species per station) and biomasses (39 ± 13 and 47 ± 13 g m-2) but displayed differing abundances (1140 ± 100 vs. 4070 ± 790 ind. m-2) and other diversity indices. We observed a decline in the proportion of polychaetes, accompanied by an increase in the proportion and diversity of bivalves, as well as a rise in the abundance of infaunal species, sub-surface deposit feeders, and mobile suspension feeders, in response to the increasing vertical carbon flux. The potential increase in anthropogenic pressures related to oil development in the northeastern Barents Sea highlights the importance of our study for conservation and monitoring efforts in the region.

New sublittoral species of Laonice (Annelida: Spionidae) from southern Asian coasts.

Four new species of Laonice (Annelida: Spionidae) are described from the southern and southeastern coasts of Asia: L. (Laonice) persica sp. nov., L. (Laonice) siamica sp. nov., L. (Sarsiana) apicelamella sp. nov. and L. (Sarsiana) andamanica sp. nov. Materials were collected within the scope of different environmental surveys performed by the consulting company Créocéan, ranging from the Persian Gulf (Indian Ocean) on the west, to the Gulf of Siam (Pacific Ocean) on the east. In addition, specimens found in the Gulf of Siam are tentatively attributed to L. (Sarsiana) sinica, and an English translation of the species description is provided for the first time. Different species subgroups within L. (Sarsiana) are also recognized based on key morphologic characters, though their phylogenetic relevance requires further confirmation. The scientific value of biological material collected during environmental surveys is emphasized, and contractors are encouraged to deposit reference collections in public natural history collections.

Reversible Sorptive Preconcentration of Noble Metals Followed by FI-ICP-MS Determination.

In this paper, we propose the combined procedure of noble metal (NM) determination, including fire assay, acid digestion, and reversible dynamic sorptive preconcentration, followed by flow-injection ICP-MS. Reversible preconcentration of all NMs was carried out using micro-column packed new PVBC-VP sorbent and elution with a mixture of thiourea, potassium thiocyanate, and HCl, which recovers Pd, Ir, Pt, and Au by 95% and Ru, and Rh by 90%. The proposed procedure was approved using certified reference materials.

Revision of the Laonice bahusiensis complex (Annelida: Spionidae) with a description of three new species.

The morphological reexamination of specimens previously identified as Laonice bahusiensis Sderstrm, 1920 from North European and Mediterranean collections, supported by the molecular analysis of freshly collected material, enabled the recognition of four different species in the region: the genuine L. bahusiensis, L. irinae n. sp. from North European waters, and L. grimaldii n. sp. and L. mediterranea n. sp. from the Mediterranean Sea. The morphology of these species is described and illustrated, and their distributions are clarified based on old and new materials. A key for their identification is also provided. The Bayesian analysis of the COI sequences (483 bp) showed that these four species form a clade, namely the L. bahusiensis species complex, morphologically characterized by the continuous dorsal crests on postbranchiate chaetigers in the adults. The genetic p-distances between the species of the complex ranged from 13.27% to 17.99%, while the intraspecific variability ranged from 0.6% to 1.57%. Together with the sister species Laonice cirrata (Sars, 1851), the L. bahusiensis complex formed the Laonice (Laonice) clade, which is morphologically characterized by the prostomium fused with the anterior peristomial margin. However, the monophyly of the L. bahusiensis complex, as well as that of the clade Laonice (Laonice), needs to be further supported through the analysis of a greater set of genes from a larger number of species.

Two new deep-sea species of Laonice (Annelida: Spionidae) from the Mediterranean Sea.

Two new deep-sea species of the genus Laonice belonging to the subgenera Sarsiana and Appelloefia respectively, are described from the Mediterranean Sea. Complete specimens of the subgenus Appelloefia were studied for the first time, and the new information collected raised questions on the boundaries between the subgenera Appelloefia and Norgensia. The presence of characters in L. barcinensis sp. nov. previously considered to be exclusive to each these two subgenera suggests that they should be regarded as synonymous. The name Appelloefia being given precedence here, according to the Principle of the First Reviser. A correction is made regarding the depth range of Laonice rasmusseni Sikorski Pavlova, 2018.

Rare earth elements in poplar leaves as indicators of geological environment and technogenesis.

Background and anomalous rare earth element (RЕЕ) concentrations in poplar (Populus spp.) leaves in urban areas of Siberia, Russian Far East, and Kazakhstan were determined. Regions with the highest RЕЕ levels were identified. Ratios of light to middle RЕЕs are geochemical indicators of the impacts of oil refining and mining. Airborne dust transport by prevailing winds from ash and slag dumps of power plants and industrial sites, and alluvial terraces control the REE distribution in cities.

The natural history of renal cell carcinoma with pulmonary metastases illuminated through mathematical modeling.

The goal of this study is to uncover some unobservable aspects of the individual-patient natural history of metastatic renal cell carcinoma (RCC) through mathematical modeling. We analyzed four clear cell RCC patients who at the time of primary tumor resection already had pulmonary metastases. Our description of the natural history of cancer in these patients was based on a parameterized version of a previously proposed very general mathematical model adjusted to these clinical cases. For each patient, identifiable model parameters were estimated by the method of maximum likelihood from the volumes of lung metastases computed from CT scans taken at or around the time of surgery. The model-based distribution of the volumes of lung metastases with likelihood maximizing parameters provided an excellent fit to the data for all patients analyzed. We found that, according to the model, the most likely scenario in all four patients had the following clinically important features: (1) duration of metastatic latency was very small compared to the growth period; (2) seeding of the first lung metastasis occurred before primary tumor reached detectable size, which implies that early cancer detection would not have prevented metastasis; (3) primary tumor contained a relatively fast growing subpopulation of metastasis-producing cells, which is consistent with the observed aggressive course of the disease; and (4) the volume of the primary tumor at the time of metastasis survey does not seem to be correlated with such characteristics of the metastatic burden as the number of detected lung metastases, their total volume, and the volume of the largest detected lung metastasis.

Two new species of Laonice (Norgensia) (Spionidae, Polychaeta) from subtropical Atlantic and subequatorial Pacific coasts of North America.

Two new species, Laonice costaricensis sp. nov. and L. rasmusseni sp. nov., belonging to the subgenus Norgensia Sikorski et al., 2017 were found in material from the Pacific collected from Coco Island off the coast of Costa Rica and from the Atlantic collected from Sapelo Island off the coast of Georgia (USA), respectively. Laonice cosaricensis is very close morphologically to L. lemniscata but without transdorsal membranes and having as usual capillaries in several anterior parapodia arranged in three vertical rows. Laonice rasmunsseni has genital pouches starting much anteriorly than in all known species from this subgenus. An identification key for the species belonging to this subgenus is given.

Three new species of Laonice (Polychaete: Spionidae) from West and Southwest Africa.

Three new species of Laonice (Polychaete: Spionidae): L. galatheae, L. cricketae, L. olgae-are described from South and West Africa (along the coast from 31°14.1'S to 04°44'N) based on Danish and South African zoological collections. Arguments relative to the morphological heterogeneity of the genus Laonice are advanced. The arguments are based on the following characters: degree of fusion of prostomium with peristomium at the anterior margin, degree of variability of all numerical characters, arrangement of anterior capillaries in two or more vertical rows, presence or absence of transversal dorsal membranous crests in the "post nuchal organ" and presence of genital pouches only on very limited number of segments or other pattern. Authors think it is obvious today an existence of at least four morphologically separate groups of species inside the Laonice-genus: "L. cirrata", "L. sarsi", "L. appelloefi" and "L. norgensis" groups. Eight species names from 34 valid names in the genus are still with unclear affiliation. L. quadridentata is treated now as a junior synonym of L. brevicornis. An opinion is expressed about L. insolita not belonging to the genus Laonice because of discrepancy the generic diagnosis.

A quantitative insight into metastatic relapse of breast cancer.

BACKGROUND: Metastatic relapse is the principal source of breast cancer mortality. This work seeks to uncover unobservable, yet clinically important, aspects of post-surgery metastatic relapse of breast cancer and to quantify effects of surgery on metastatic progression. METHODS: We classified metastases into three categories: (1) solitary cancer cells that were formed before or during surgery and either circulate in blood or are lodged at various secondary sites; (2) dormant or slowly growing avascular metastases; and (3) vascular secondary tumors. We developed a general mathematical model aimed at describing post-surgery dynamics of these three metastatic states. One parametric version of the model assumed that sojourn times of metastases in the three states are exponentially distributed while another was based on Erlang distribution. Model parameters were estimated from a sample of metastatic relapse or censoring times for 673 breast cancer patients treated with surgery. RESULTS: We estimated the expected number of metastases at surgery and mean sojourn times for the three states and found that both are decreasing with state number. We also computed the probability that metastatic relapse resulted from a metastasis in a given state at surgery. The values of these attribution probabilities suggest that under the Erlang model all three states have a considerable effect on metastatic relapse while in the case of exponential model this is true for states 1 and 2 only. CONCLUSIONS: (1) In some patients metastasis occurred before surgery; (2) our results confirm significance of metastatic dormancy; (3) according to the model surgery stimulates escape from dormancy, promotes angiogenesis and accelerates metastatic growth in a fraction of breast cancer patients. Taken summarily, these findings call into question the benefits of primary tumor resection for certain categories of breast cancer patients.

Optimal screening schedules for prevention of metastatic cancer.

We develop methodological, mathematical, statistical, and computational approaches to constructing schedules of cancer screening that maximize the probability that by the time of primary tumor detection it has not yet metastasized. Solving this problem is based on a comprehensive mechanistic model of cancer progression. We apply the model with realistic parameters and the screening optimization methodology to mammographic screening for breast cancer within the American female population. We uncover some general patterns of optimal screening schedules. We show that optimization of screening regimens leads to a significant reduction in the probability of detecting breast cancer that has already disseminated.

Self-concentration effects in preparative SEC of mineral electrolytes using nanoporous neutral polymeric sorbents.

Separation of mineral electrolytes according to size exclusion mechanism using neutral nanoporous polystyrene sorbents and carbonaceous materials has been examined in detail on hand of HCl and CaCl2 solutions, taken separately and in the mixture. Phase distribution coefficients of the above electrolytes have been measured under static conditions at different concentrations. The k-values and their dependence on the concentration were correlated with the elution curves of the components from a chromatographic column. Both the static and dynamic data suggest a strong dependence of the hydration number and effective size of ions on the concentration. Self-concentration of HCl in small pores and that of CaCl2 outside of small pores exhibits itself in both static and chromatographic experiments and results from the relocation of the components largely within the volume of the initial mixture. Additional apparent "retention" of HCl in the porous volume of the sorbent in concentrated electrolyte mixtures was shown to be caused by the competition between all ions of the system for hydration water. Increased separation selectivity and enhanced self-concentration effects for more concentrated mixtures point to preparative and industrial perspectives of size exclusion chromatography (SEC) of complex electrolyte mixtures on nanoporous neutral sorbents.