Trophic transfer of paralytic shellfish toxins from clams (Ruditapes philippinarum) to gastropods (Nassarius festivus)

A local strain of the dinoflagellate Alexandrium tamarense (ATCI01), which predominantly produces C2 toxin, was fed to the clams (Ruditapes philippinarum) under laboratory conditions. Concentrations of paralytic shellfish toxins (PSTs) in the dosed clams were determined by High Performance Liquid Chromatographic (HPLC) analyses, and the clams were homogenized and then fed to the gastropods (Nassarius festivus). In the toxin accumulation phase, which lasted for 42 days, concentrations of PSTs increased in the snails gradually, reaching a maximum of 1.10 nmole g(-1) at the end of the exposure period. The toxin content of the homogenized clams (food) was 13.18 nmole g(-1), which was about 12-fold higher than the PST content in the snails. Between day 43 and day 82, the snails were fed with non-toxic clams, and this period represented the depuration phase. Accumulation and depuration rates of PSTs in the snails, N. festivus, were determined by fitting the experimental data to user-defined parameters program using a one-compartment model. Two different modeling approaches were used to derive the accumulation and depuration rates. The first approach is to derive both values from the data for the toxin uptake. The second approach is to derive depuration rate from the depuration data and then to derive uptake rate, allowing for toxin depuration, from the data for toxin uptake. The first approach yielded more consistent results for the toxin concentration at the end of the uptake period, when compared with the experimental data. The toxin uptake and depuration rates were 1.64 (pmole of toxin into snail per day) per (nmole g(-1) of toxin in food) and 0.06+/-0.02 day(-1) (mean+/-SE), respectively. The toxin profiles of snails were similar to the clams, but different from the algae. Besides C toxins (C1 and C2), dcGTX2 and dcGTX3 were also detected in both clams and snails. The beta:alpha epimer ratio gradually decreased during trophic transfer and approached a ratio of 1:3 (26.4 mol%:73.6 mol% at day 42) in the snails, near the end of the accumulation period.     

Survey of urinary nickel in residents of areas with a high density of electroplating factories

The soil metal contamination arising from the discharge of the high density of electroplating factories in the geographic center of Taiwan has prompted concern about human exposure to harmful metals. This study aimed to determine the levels of nickel (Ni) in urine of residents living in the high vs. low factory-density areas, and to examine how these levels relate to gender and age. A total of 660 subjects, resident in the area for the last five years, were sampled according to the stratified random sampling approach, at ages 35-44, 45-54, and 55-64years for both genders. Metals in urine samples were analyzed by inductively coupled plasma mass spectrometry (ICPMS). The geometric mean (95% confidence interval (CI)) of urinary Ni was 6.30 (5.99-6.62)mug/l. The 0.95 parametric reference interval (90% CI) of urinary Ni was estimated to be 1.74 (1.62-1.88) to 22.73 (21.14-24.44)mug/l. Subjects in the areas with a high density of electroplating factories had significantly higher urinary Ni levels than those in the low-density areas, but both types of areas had obviously higher urinary Ni levels when compared to the non-occupationally exposed population from western countries. The health significance of elevated urinary Ni and its causative factors remain to be determined.     

Exploration of sustainable development by applying green economy indicators

Following the global trend of sustainable development, development of green economy is the best way of slowing the negative ecological and environmental impact. This research establishes the Taiwan's green economic indicators based on the ecological footprint and energy analysis. The results are as follows: Taiwan's ecological footprint in 2008 intensity index was at 4.364; ecological overshoot index was at 3.364, showing that Taiwan's ecological system is in overload state. Moreover, this study utilizes energy analysis model to study the sustainable development of Taiwan. Findings showed that total energy use in 2008 was 3.14 × 10(23)?sej (solar energy joule, sej), energy of renewable resources was 1.30 × 10(22)?sej, energy of nonrenewable resources was 2.26 × 10(23)?sej, energy of products from renewable resources was 1.30 × 10(22)sej, energy of currency flow was 8.02 × 10(22)?sej and energy of wastes flow was 6.55 × 10(22)?sej. Taiwan's energy per capita and the utilization rate of energy is lower while the environmental loading rate is significantly higher comparing to some other countries. The foregoing findings indicate that Taiwan currently belongs to an economic development pattern based on high resource consumption. The economic development is mainly established on the exploitation and utilization of nonrenewable resources. Therefore, Taiwan should change the development pattern, regulate the industrial structure, promote the utilization rate of resources, develop green pollution-free products, and enhance the sustainable development of ecological economic system.     

北京典型地铁系统可吸入颗粒物实测研究

为了解地铁环境空气污染状况,改善乘客和工作人员的环境,采用激光粉尘仪对北京地铁站外以及西直门(敞开式系统)、五道口(半高安全门系统)、西土城(全高安全门系统)和北土城(屏蔽门系统)等典型地铁系统站台和车厢空气中的细颗粒物(PM_(2.5))和可吸入颗粒物(PM_(10))在列车驶入前后的浓度(指质量浓度)大小,以及站台和车厢空气中PM_(2.5)和PM_(10)浓度随时间的变化规律进行了研究,并分析了PM_(2.5)与PM_(10)的浓度比值,以及地铁站外、站台与车厢空气中PM_(2.5)和PM_(10)源的相关性。结果表明:外界雾霾严重时,站内空气污染加重,地铁驶入后引起PM_(10)浓度增加,屏蔽门和车门的打开使得站台和车厢空气中的PM_(10)颗粒物浓度加速上升,以PM_(2.5)为主,且其浓度的变化随屏蔽门的启闭呈现一定的规律性。     

Tail loss compromises immunity in the many-lined skink, Eutropis multifasciata

Tail autotomy incurs energetic costs, and thus, a trade-off in resource allocation may lead to compromised immunity in lizards. We tested the hypothesis that tailless lizards will favor constitutive innate immunity responses over an energetically costly inflammatory response. The influence of fasting and colorful ornamentation was also investigated. We experimentally induced tail autotomy in the lizard Eutropis multifasciata and found that inflammation was suppressed by tail loss, but not further affected by fasting; the suppressive effect of colorful ornamentation was manifested only in males, but not in females. Constitutive innate immunity was not affected by any of these factors. As expected, only costly inflammation was compromised, and a less expensive constitutive innate immunity might be favored as a competent first-line defense during energetically demanding periods. After considering conventional trade-offs among tail regeneration and reproduction, further extending these studies to incorporate disease risk and how this influences escape responses to predators and future reproduction would make worthwhile studies.     

Characterization of activated carbons prepared from sugarcane bagasse by ZnCl2 activation.

Activated carbons were prepared from the agricultural waste of sugarcane bagasse by the chemical activation with zinc chloride (ZnCl2) at the activation temperature of 500 degrees C with soaking time of 0.5 hour. The influence of activation parameters on the final carbon products was examined by varying the impregnation ratio (i.e., mass ratio of added ZnCl2 to bagasse) and bagasse size. The physical properties of carbon products were characterized by nitrogen adsorption/desorption isotherms (at 77 K) and helium displacement method. The surface area and pore volume of carbons were thus obtained by the BET equation and t-plot method. Also, the particle density and porosity of carbons were estimated by the total pore volume and true density. The increases of the values of surface area and pore volume are approximately proportional to the impregnation ratio. The microporous carbon product with the BET surface area of 905 m2/g and total pore volume of 0.44 cm3/g was obtained in the present study. Further, the adsorption isotherms of two acid dyes from aqueous solutions onto the carbon products were performed at 30 degrees C. The results show that the adsorption isotherms of acid dyes with high molecular weight or large molecular size on the microporous adsorbents of activated carbons are plateau forms, indicating multilayer adsorptions, which may be attributed to the steric hindrance of the adsorbate molecules.