Research Article Phytoremediation of heavy metal-contaminated water and sediment by Eleocharis acicularisPhytoremediation is an environmental remediation technique that takes advantage of plant physiology and metabolism. The unique property of heavy metal hyperaccumulation by the macrophyte Eleocharis acicularis is of great significance in the phytoremediation of water and sediments contaminated by heavy metals at mine sites. In this study, a field cultivation experiment was performed to examine the applicability of E. acicularis to the remediation of water contaminated by heavy metals. The highest concentrations of heavy metals in the shoots of E. acicularis were 20 200 mg Cu/kg, 14 200 mg Zn/kg, 1740 mg As/kg, 894 mg Pb/kg, and 239 mg Cd/kg. The concentrations of Cu, Zn, As, Cd, and Pb in the shoots correlate with their concentrations in the soil in a log-linear fashion. The bioconcentration factor for these elements decreases log-linearly with increasing concentration in the soil. The results indicate the ability of E. acicularis to hyperaccumulate Cu, Zn, As, and Cd under natural conditions, making it a good candidate species for the phytoremediation of water contaminated by heavy metals.

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Accretion of a large number of seamounts or fragments of huge oceanic plateaus is recorded in the geology of Japan. Major accretion occurred twice; a late Early Carboniferous seamount chain acefeted in latest Permian to Middle Jurassic time, and a Late Jurassic oceanic plateau acefeted in the Early Cretaceous. The Late Jurassic plateau now in northern Japan and Sakhalin is here named the "Sorachi Plateau" and a Tithonian age for it is well documented on the basis of microfossils from pelagic cherts and limestones. Petrochemical characteristics of basalts suggest two kinds of sources; depleted mantle under oceanic lithosphere and enriched mantle related to plume upwelling. All the accreted fragments in Japan can be traced back to the central part of the Panthalassa by using paleomagnetic data and plate "trajectory analysis." The timing of generation of the accreted seamount chain and the plateau is consistent with a time of global change. Their place of origin, in the mid-Panthalassa, retains a positive residual geoid anomaly and slow Vp in the lower mantle, which suggest a past upwelling of hot material from the core-mantle boundary. Introduction Recently, large-scale igneous activities such as continental flood basalts and oceanic plateau volcanism have aroused interest because of their significance in understanding activity in Earth's interior and possible catastrophic effects on the global change of environment [e.g., Courtillot, 1990; Richards et al., 1989; Coffin and Eldholm, 1991; Duncan and Richard, 1991]. Periodicity of such igneous activity through geologic history has also been suggested [Courtillot and Besse, 1987; Rampino and Stothers, 1988; Larson, 1991a, b]. The central to southern Pacific Ocean is a place where several active hot spots are located. A positive residual geoid anomaly [Anderson, 1982; Chase and Sprowl, 1982; LePichon and Huchon, 1983] and slow Vp in the lower manfie [Morelli and Dziewonski, 1987; Tanirnoto, 1990; Fukao, 1992] suggest a broad upwelling of hot manfie beneath this region. The upwelling can be traced back to the Mesozoic by using hot spot tracks and plate kinematic reconstructions [Anderson, 1982; Chase and Sprowl, 1982; Tarduno et al., 1991; Anderson, 1990]. Cretaceous plume upwelling in this region is documented by studies of huge plateaus such as Ontong Java, Hess Rise, and others [Nakanishi et al., 1989, 1992a, b; Larson, 1991a; Tarduno et al., 1991]. Plume activity before the Cretaceous in the old Pacific Ocean (Panthalassa superocean) is obscured because few Jurassic parts of plates are preserved. The only way to clarify plume activity before the Cretaceous is through a geological analysis of accreted oceanic materials within circum-Pacific orogens. We have reviewed accretionary complexes in the western circum-Pacific orogens, especially in the Japanese islands, and have identified two periods of accretion of seamount chains or plateaus; accretion of a late Early Carboniferous seamount chain between the end of the Permian and the Middle to Late Jurassic and of a Lat...

Mercury concentrations in the environment (river sediments and fish) and in the hair of artisanal gold miners and inhabitants of the Gorontalo Utara Regency were determined in order to understand the status of contamination, sources and their impacts on human health. Mercury concentrations in the sediments along the Wubudu and Anggrek rivers are already above the tolerable level declared safe by the World Health Organization (WHO). Meanwhile, commonly consumed fish, such as snapper, have mercury levels above the threshold limit (0.5 μg/g). The mean mercury concentrations in the hair of a group of inhabitants from Anggrek and Sumalata are higher than those in hair from control group (the inhabitants of Monano, Tolinggula and Kwandang). The mean mercury concentration in the hair of female inhabitants is higher than that in the hair of male inhabitants in each group. Neurological examinations were performed on 44 participants of artisanal and small-scale gold mining (ASGM) miners and inhabitants of Anggrek and Sumalata. From the 12 investigated symptoms, four common symptoms were already observed among the participants, namely, bluish gums, Babinski reflex, labial reflex and tremor.

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In the present work, we investigate scaling rules for the ionization cross sections of multicharged ions on molecules of biological interest. The cross sections are obtained from distorted-wave calculations for atomic targets combined with a stoichiometric model for the molecules proposed in [Mendez et al. J. Phys B (2020)]. We examine ions with charges Z from +1 to +8 in five nucleobases -adenine, cytosine, guanine, thymine, uracil-, tetrahydrofuran, pyrimidine, and also in water. We propose a scaling with the ion charge, which is valid in the intermediate to high energy range, i.e. 0.2-5 MeV/amu for oxygen impact. We extend our work to a universal scaling for any ion and molecule, merging the forty ion-molecule systems analyzed here into a single band. Furthermore, our model proved to be valid for other molecules too.The ionization of biological molecules by multicharged ions has gained increasing interest due to medical and environmental reasons [1], from medical treatments [2-4] to contaminant recognition in biological materials [5,6]. Many semiempirical [7] and theoretical efforts are currently being undertaken [8][9][10][11][12][13] to get reliable values for the ionization cross sections of these molecules.Recently, we combined the continue distorted-wave calculations (CDW) for atoms and the simple stoichiometric model (SSM) to approximate the ionization cross sections of complex molecular targets by charged ions [8]. The CDW-SSM approximation showed reasonable results for over a hundred of ion-molecule systems. As expected, in the high energy range (i.e. above 5 MeV/amu) the ionization cross sections present the Z 2 dependence predicted by the first Born approximation. However, at intermediate energies, the dependence with Z is more complex, and non-perturvative models are mandatory.The intention of this letter is to give a follow up of our previous work [8] by proposing a scaling with the ion charge Z of the ionization cross sections of complex molecules, valid at intermediate energies. In general, scaling rules are used as first-order tests in experimental measurements and multipurpose codes. Based on [8], we propose a universal scaling for any ion-target system.At intermediate impact energies, Janev and Presnyakov [14] suggest σ Z versus E Z as the natural reduced form of the ionization cross section σ and the incident ion energy E. Much more recently, Montenegro and co-workers [15,16] proposed an alternative scaling by taking into account that σ is a function of Z 2 E. Their scaling, given bykeeps the Z 2 E relationship for any value of α. In Ref.[15], the authors propose α = 4 3 for ionization of He and H 2 by different charged ions. Combining our recent CDW-SSM results [8] and Eq. (1), we propose here a Z-scaling and implement it for forty collisional systems. The ion-molecule systems are composed of eight targets: the DNA and RNA nucleobases -adenine, cytosine, guanine, thymine, uracil-, tetrahydrofuran (THF), pyrimidine, and water; and five charged ions: H + , He +2 , Be +4 , C +6 , and O +8 . We ...