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Sargassum polycystum C. Agardh, a brown alga that is widely distributed in tropical areas, has significant economic value by virtue of its use as food, traditional medicine, animal fodder, and chemical products in Asian countries. In order to explore suitable conditions for the aquaculture of this alga, we used 9-10 cm long branches of S. polycystum to assess the effects of various environmental factors, including temperature, salinity, and irradiance upon the relative growth rate (RGR), photosynthetic pigment content, and chlorophyll fluorescence characteristics of this species. Data showed that S. polycystum exhibited a relatively broad tolerance to various environmental conditions, and grew well in different conditions of temperature, salinity, and irradiance, ranging from 15 to 25 °C, 20-40 PSU, and 10-80 μmol photons·m−2·s−1. The maximum RGR of S. polycystum occurred at 23 °C, 32 PSU, and 20-80 μmol photons·m−2·s−1 (P < 0.05). Temperature had a significant effect (P < 0.05) upon RGR and the chlorophyll fluorescence characteristics of S. polycystum, and lower temperature (10 °C) led to rapid reductions in the maximal photochemical quantum yield of photosystem II (Fv/Fm) and non-photochemical quenching (NPQ) values. Salinity exhibited a relatively weak effect upon the growth of S. polycystum, and the plant was able to survive at salinities from 16 to 40 PSU; during a two-week cultivation period, significant differences in RGR were not observed among different salinity conditions until 2 weeks of cultivation. Chlorophyll a and carotenoid content of S. polycystum decreased as irradiance increased (P < 0.05), and photo-inhibition occurred under higher levels of irradiance (> 80 μmol photons·m−2·s−1). These physiological data provide valuable data related to the successful cultivation of S. polycystum under controlled conditions. [ABSTRACT FROM AUTHOR]

Speciation analysis of long-lived I in seawater can provide useful information on the source of water masses. This paper presents an improved method for speciation analysis of I based on coprecipitation of iodide as AgI with AgSO and AgCl. By adding a small amount of I carrier, the separation efficiency of iodine species and the accuracy and precision of I measurement are remarkably improved. I species in depth profiles of seawater from the Antarctic were analyzed for investigation of water circulation in the Antarctic. [ABSTRACT FROM AUTHOR]

The low-thrust trajectory optimization with complicated constraints must be considered in practical engineering. In most literature, this problem is simplified into a two-body model in which the spacecraft is subject to the gravitational force at the center of mass and the spacecraft's own electric propulsion only, and the gravity assist (GA) is modeled as an instantaneous velocity increment. This paper presents a method to solve the fuel-optimal problem of low-thrust trajectory with complicated constraints in a full ephemeris model, which is closer to practical engineering conditions. First, it introduces various perturbations, including a third body's gravity, the nonspherical perturbation and the solar radiation pressure in a dynamic equation. Second, it builds two types of equivalent inner constraints to describe the GA. At the same time, the present paper applies a series of techniques, such as a homotopic approach, to enhance the possibility of convergence of the global optimal solution. [ABSTRACT FROM AUTHOR]

The leaves of many plants are red during particular stages of their lives, but the adaptive significance of leaf colouration is not yet clearly understood. In order to reveal whether anthocyanins play a similar role (i.e. antioxidants) in different seasonal contexts, this study investigated species with red young leaves in the subtropical forest of Dinghushan biosphere reserve (South China) during summer and winter and compared group leaf characteristics between the two seasons. Of 62 total species, 33 exhibited red young leaves in summer only, 6 in winter only, and 23 in both seasons. The anthocyanins extracted from most of these species had an absorption peak at ~530 nm. Frequency distribution analysis showed that the species containing anthocyanins at levels ranging from 0.02 to 0.04 μmol cm−2 occurred most frequently in summer or winter. Based on conditional grouping of the species, no significant variation was observed in the average anthocyanin contents and antioxidant abilities between summer and winter; the flavonoid content in summer was 2-fold that in winter, whereas the anthocyanin:flavonoid ratio in summer was only half that in winter. Moreover, a positive correlation between anthocyanins and flavonoids was found in summer. Therefore, it is less likely for anthocyanins to serve as antioxidants in summer than winter, because such a function in summer leaves is readily replaced by other flavonoids. [ABSTRACT FROM AUTHOR]

A rapid analytical method for sequential separation and determination of the most significant α- and β-emitting radionuclidic impurities in 99Tc radiopharmaceutical raw material is presented. Successive HTiO co-precipitation steps were first conducted for effective removal of 99Tc to avoid its spectral interference on the determination of β-emitting nuclides by liquid scintillation counting. A sequential chromatographic method was applied for simultaneous separation and purification of actinide and lanthanide isotopes. A series of K99TcO4 solution spiked with known quantities of 238Pu, 239Pu, 241Pu, 237Np, 241Am, 244Cm and 147Pm were analyzed for method evaluation, demonstrating that the method would meet the analytical requirements for radionuclidic impurity evaluation of K99TcO4 raw material. [ABSTRACT FROM AUTHOR]

A method using solvent extraction following a preconcentration of iodine by evaporation was developed for separation of iodine in waters associated with coalbed methane (CBM) for the determination of 129I using accelerator mass spectrometry, for exploration of CBM resources. The 129I/127I ratios in water samples collected in a CBM field have been determined using the developed method to be (1.6–2.4) × 10–11, which are 2–3 orders of magnitudes lower than that of environmental samples in Xi'an, but 2 orders of magnitude higher than the procedure blank of (1.5–2.1) × 10–13, confirming no measurable crossover contamination during sample analysis and slightly input of modern water in the CBM water. [ABSTRACT FROM AUTHOR]

WNT-ß-catenin-TCF pathway is involved in carcinogenesis and foetal development. As a member of the WNT gene family, Wnt8A encodes secreted signalling proteins and responds to many biological processes. However, similar research on the effects of genetic variations of Wnt8A gene on growth traits is lacking. Therefore, in this study, polymorphisms of Wnt8A were detected in 396 animals from Chinese Qinchuan cattle using DNA pool sequencing and PCR-RFLP methods. Four novel single-nucleotide polymorphisms (SNPs) of Wnt8A gene were identified, including three mutations in introns (g.T-445C, g.G244C and g.G910A) and one in exon (g.T4922C). Additionally, we examined the associations of four SNPs with growth traits. The results revealed that SNP2 (g.G244C) was significantly associated with shoulder height, hip height, body length, hip width, and body weight ( $$P < 0.05$$ ). SNP3 (g.G910A) also displayed notable effects on hip width ( $$P < 0.05$$ ). Meanwhile, the haplotype combination CC-GC-GA-CC was strongly associated with heavier, taller and longer animals ( $$P < 0.05$$ ). These results show that the Wnt8A gene may be a potential candidate gene, and the SNPs could be used as molecular markers in early marker-assisted selection in beef cattle breeding programmes. [ABSTRACT FROM AUTHOR]