와편모조류 시스트 분리를 위한 Panning 방법과 SPT 용액방법의 비교

Well-crystallized groundmass fractions are commonly used to obtain reliable K-Ar ages for volcanic rocks, as phenocrysts potentially contain excess 40Ar. In general, phenocrysts are removed by magnetic separator, heavy liquid separation, and hand picking. Heavy liquid separation utilizes sodium polytungstate (SPT) solution, which replaced toxic heavy liquids such as bromoform in the 1980s. Recently, a vacuum pump has been used to reduce the filtration time for heavy liquid separation using SPT solution, which has a high viscosity. This note describes the separation procedure for gentle suction filtration using a hand vacuum pump, which can be safely completed in 50-60 minutes per sample. The procedure was tested on andesite and basalt samples from Hakusan, Miyakejima, and Etna Volcanos. Separation of the groundmass fraction from the phenocryst fraction was successful for all andesite samples, whereas separation was incomplete in some of the basalt samples, probably because the gravity of groundmass grains was heavier than the maximum gravity of the SPT solution (3.11 g/cm3).

A solution of sodium polytungstate (SPT) is used as a heavy liquid in global soil studies. This reagent has found wide use because it is nontoxic, incombustible, well soluble, environmentally safe, and of low viscosity. There is a relatively simple and accessible method for its regeneration. The reagent contains no carbon compounds, which is important for studying organic matter with the use of carbon isotopes. However, some chemical properties of SPT should be taken into consideration to ensure the obtainment of incoherent and sorbed solid-phase forms of organic matter. A modification of granulodensimetric fractionation is described that allows separating the solid-phase fractions of soils without changes in the content and isotope composition of the organic carbon and organic nitrogen in the separated material.

Bone density is considered one of the many factors influencing bone structure and DNA preservation. For this reason, it is of interest in fields such as anthropology, palaeontology, and genetics. This study describes a method for bone density assessment by gradient centrifugation in Sodium Poly-Tungstate (SPT) solutions (from 2.1 to 2.6 g/cm3). Fifty milligrams of bone powder (size range of 20–50 µm) were used, with an average recovery of 89.9 (IC = 3.3% at 95% of probability). In the first phase of the experiment, the protocol was applied to ten femurs: three exhumed from the WWII mass grave of Ossero, three aged (43–50 years old) femurs from a museum collection and four fresh controls. In the subsequent phase, the analysis was extended to three petrous bones, three metacarpals, and three metatarsals exhumed from the WWII mass grave. The SPT density gradient profiles revealed marked differences among the three femur sample sets: more than 80% of the powder from control femurs was recovered in fractions with a density ≤ 2.2 g/cm3, whereas approximately 45% of the femurs from the mass grave showed a density > 2.6 g/cm3. The remaining three aged femurs displayed peculiar density patterns. Among the other bone types, metatarsals showed the lowest density values, followed by petrous bones and metacarpals. To detect degradation signatures, all nineteen bone powders were also analysed by ATR-FTIR. The femurs from the mass grave exhibited spectral features consistent with mineral recrystallisation and degradation of the organic phase, whereas the other three aged femurs showed peculiar spectral profiles; metacarpals, petrous bones and metatarsals showed intermediate spectra. PCA was applied to SPT and ATR-FTIR data, revealing correlations that support the SPT method as a novel tool for bone quality assessment. Although based on a limited sample size, this preliminary work demonstrates that SPT gradient analysis is an effective, low-cost, rapid and reliable method for assessing bone density, with potential applications in different disciplines studying aged bone samples. Lastly, principal component analysis (PCA) revealed a correlation between bone density and the yield of DNA recovered from the ten femoral specimens.

Soil samples from a rainforest, a papaya plantation, a pure Brachiaria humidicola pasture and a B. humidicola/Desmodium ovalifolium mixture were analyzed for fertility parameters. Soils were sieved to >100 µm and the organic matter light fraction was obtained by 1.8 g mL−1 density separation in a sodium polytungstate solution which was subsequently incubated under anaerobic conditions. The effect of different density agents (sodium polytungstate, Ludox and sodium iodide) on mineralization was also tested on a temperate and a tropical soil and on maize tissue.

ABSTRACTIdentifying and tackling recrystallization is a critical factor in the reliable radiocarbon (14C) dating of carbonates, since exogenous carbon can be incorporated and thus mask the real age of the samples. Vermetids are among the most important bioindicators used for paleo sea-level reconstruction, and the accuracy of their chronology can significantly impact sea-level curves. Age differences larger than 1 14C kyr before and after acid etching, combined with X-ray diffraction (XRD) analysis that indicates a significant amount of calcite still remains in the shell, led us to apply the previously developed carbonate density separation protocol (CarDS). Using a solution of sodium polytungstate, with density of 2.80 g/cm3, we successfully separated different carbonate fractions for a set of 10 vermetid samples from the coast of Rio de Janeiro, southeast of Brazil. Each separation was verified by XRD analysis and the 14C concentrations of different fractions were compared. The results show that the calcite fraction in the studied vermetid samples varied from 12 to 63% and aragonite fraction ages are up to 2 14C kyr older than the raw samples, thus confirming the efficacy of CarDS in removing young carbonates and the importance of density separation to vermetids prior to accelerator mass spectrometry (AMS) dating.

Evidence for the production of asexual resting cysts in a free-living species of Symbiodiniaceae (Dinophyceae)

The importance of nucleolar changes in cancer cells is underestimated in tumour pathology. There is evidence that the nucleolus is the mirror of a series of metabolic changes that characterize cancer cells. Cell entry into the cell cycle is always associated with up-regulation of the nucleolar function and increased nucleolar size, which are also directly dependent on the rapidity of cell cycle progression. Furthermore, alterations of the major tumour suppressor retinoblastoma (Rb) and p53 pathways also contribute to the stimulation of nucleolar function and to nucleolar enlargement. High cell growth fraction, high cell growth rate and disruption of the Rb and p53 pathways are responsible for greater aggressiveness of cancer tissues. Therefore, the evaluation of nucleolar size allows one to obtain reliable information on the clinical outcome of the cancer: the greater the nucleolar size, the worse the tumour prognosis. Indeed, a series of studies carried out on numerous human tumours has shown that nucleolar hypertrophy (prominent nucleolus) was an independent predictive and prognostic parameter of a fatal clinical outcome.

Prior literature has explored the developmental trajectories and the comorbidity of adolescent alcohol use and rule-breaking behavior; however, there are several limitations of the current literature. First, little evidence exists that tested the longitudinal trajectories of both alcohol use and rule-breaking behavior while controlling for the shared effects of physical aggression, exposure to family violence, and demographic variables (e.g., gender and race). Second, limited studies have tested the longitudinal effects of baseline and growth of alcohol use on baseline and growth of rule-breaking behavior. Third, scant studies have estimated the developmental categories of alcohol use (e.g., LL: low baseline alcohol use and low growth rate; LH: low baseline alcohol use and high growth rate; HL: high baseline alcohol use and low growth rate; HH: high baseline alcohol use and high growth rate) on rule-breaking longitudinally. Therefore, the present study utilized a sample of 1,872 adolescents to address these limitations in the literature. Results indicated that while alcohol use progressed across four-time points, rule-breaking behavior did not. Furthermore, the baseline and growth rate of alcohol use positively predicted the baseline and the growth rate of rule-breaking behavior. Finally, adolescents who were classified within the high baseline and high growth subgroup were more likely to engage in rule-breaking longitudinally. Practical and theoretical implications are discussed. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Lactic acid production from lactose by Lactobacillus plantarum: kinetic model and effects of pH, substrate, and oxygen

Palynostratigraphie du Callovien-Oxfordien (Jurassique) dans les Terres noires, sud-est France

The Tuscahoma Sand of the Wilcox Group is composed of fine-grained sand, laminated sandy clay, marl, and lignite. It forms a poorly exposed belt from southeastern Alabama extending north-westward into western Alabama and eastern Mississippi. It is assigned to the late Paleocene planktonic foraminiferal Morozovella velasocoensis interval zone. Lignites in the Tuscahoma Sand occur as parasequence deposits in the highstand systems tract of a type 2 depositional sequence near the top of the formation. Organic debris associated with these highstand systems tract deposits are dominated by land-derived plant tissues such as angiosperm and gymnosperm pollen, spores of ferns, lycopods, and fungi, plant cuticle, wood in various states of degradation, charcoal or inertinite, cysts of fresh-water algae, and resins. Marine influence in some samples is indicated by the rare occurrence of dinoflagellate cysts, microforaminiferal tests linings, and the presence of gray, amorphous organic matter. Three palynofacies are recognized within highstand systems tract deposits in the upper Tuscahoma Sand based on the occurrence of organic debris. They represent fresh-water swamp, brackish marsh, and marginal to shallow-water marine depositional environments. Lignites in the Tuscahoma Sand are dominated by an angiosperm pollen assemblage. Pollen similar to that produced by the Betulaceae and Myricaceae, modern arborescent angiosperms, is common in these assemblages, as are fern spores, spore of Sphagnum, woody tissue, and charcoal. Gymnosperm pollen is rare, and marine forms are absent. This assemblage reflects deposition under fresh-water swamp conditions. Carbonaceous clay samples vary in the composition of organic debris. However, many are characterized by the occurrence of herbaceous angiosperm pollen such as Carex, Arecipites, Calamuspollenites, and Liliacidities. Arborescent angiosperm pollen is also common, as are fern spores. Bisaccate conifer pollen is common, and dinoflagellate cysts are rare. Fungal elements are abundant, and woody tissue is commonly more degraded than in lignite samples. This assemblage represents deposition in coastal, brackish marsh environments. Organic debris in laminated clays, silts, and sands typically have angiosperm and gymnosperm pollen, dinoflagellate cysts, degraded terrestiral plant materal, and amorphous organic matter, and represent shallow marine and marginal marine deposits. End_of_Record - Last_Page 508-------

Dinoflagellate cyst distribution in surface sediments of the southern Indian Ocean

ABSTRACTWe have developed a plasma enhanced chemical vapor deposition (PECVD) technique for high-rate growth of µc-Si:H at low temperatures using hydrogen diluted monosilane source gas under high-pressure depletion conditions. It was found that material qualities deteriorate, e.g. crystallinity decreases and defect density increases with increasing growth rate mainly due to ion damage from the plasma. We have found that deuterium dilution improves not only the crystallinity but also defect density as compared to hydrogen dilution and that deuterium to hydrogen ratio incorporated in the film has a good correlation with crystallinity. The advantages of the deuterium dilution are ascribed to lower ion bombardment due to slower ambipolar diffusion of deuterium ion from the plasma. Further improvement of material quality has been achieved using a triode technique where a mesh electrode inserted between cathode and anode electrodes prevents from ion bombardment. In combination with a shower head cathode, the triode technique remarkably improves the crystallinity as well as defect density at a high growth rate. As a consequence, we have succeeded to obtain much better crystallinity and uniformity at 5.8 nm/s with a defect density of 2.6×1016cm−3. We also discuss the limiting factors of growth rate and material quality for µc-Si solar cells.

Brazil is a mega diverse country, but as consequence of habitat degradation several plant species are threatened. Quillaja brasiliensis is a rare and threatened tree species of the temperate forests of South America. We investigated protocols for germination, seedling growth and transplantation. We discuss some ecological matters that could affect the species’ establishment. We evaluated germination under a range of storage periods, temperature and light conditions, the effects of transplantation and the development of seedlings under two sowing methods. We found that seeds germinated rapidly and have a high germination rate. Temperature infl uenced germination vigour, and photoperiod infl uenced synchrony. There was increased and faster germination under controlled culture conditions. The high germination rate and rapid growth qualify Q. brasiliensis as a potential species for restoring degraded areas and enrichment programmes.

A high-entropy strategy has emerged as a promising approach to enhance the functional properties of piezoelectric ceramics for biomedical applications. For this reason, we have designed two novel high-entropy ceramics, (Bi1/2Na1/2)(Zr1/3Sn1/3Ti1/3)O3(BNZST) and (Bi1/2Na1/2)(Zr1/4Sn1/4Hf1/4Ti1/4)O3(BNZSHT), which were synthesized via a two-step solid-state reaction. The phase structure, surface morphology, biocompatibility, and in vitro bioactivity were assessed. The results showed both ceramics adopted perovskite structures. BNZST and BNZSHT ceramics had relatively even crystallite sizes and element distribution, as well as achieving piezoelectric (d33 ≥ 78 pC/N) properties. In vitro tests confirmed a high relative cell growth rate (RSG, >80%) after co-culturing BNZST or BNZSHT ceramic with murine fibroblasts L929 for more than 3 days. In particular, the surface with electric charge enhanced L929 with more extensive, widespread, and dense proliferation for the BNZST ceramic compared to ceramics without BNZST or unpolarized BNZST. The above indicated that multi-element doping and entropy stabilization established a novel pathway for developing a high-entropy bio-piezoelectric ceramics with high biocompatibility and bioactivity, providing the possibility for their use in bone repair materials.