Distribution of total mercury, methyl mercury and selenium in pod of killer whales (Orcinus Orca) stranded in the northern area of Japan: comparison of mature females with calves

Total mercury (T-Hg) and selenium (Se) concentrations in liver, kidney and muscle from a pod of killer whales including five mature females and three calves stranded in the northern area of Japan were analyzed. In the mature female, contamination level of T-Hg in the liver sample (62.2+/-21.9 microg/wet g) was markedly higher than that in kidney sample and muscle sample. The molar ratio of T-Hg to Se in the liver sample was approximately 1, and those in the kidney and muscle samples were markedly lower than 1. These results suggest that the formation of HgSe compound increases the hepatic accumulation of mercury (Hg). In contrast, contamination level of T-Hg in the calf organs was much lower than that in the mature female organs. These results suggest that the transfer of Hg from the mother to the fetus via placenta and/or to calf via milk is trace.     

Diel periodicity of pheromone release by females of Planococcus citri and Planococcus ficus and the temporal flight activity of their conspecific males

The diel periodicity of sex pheromone release was monitored in two mealybug species, Planococcus citri and Planococcus ficus (Hemiptera; Pseudococcidae), using sequential SPME/GCMS analysis. A maximal release of 2 ng/h pheromone by 9–12-day-old P. citri females occurred 1–2 h before the beginning of photophase. The highest release of pheromone by P. ficus females was 1–2 ng/2 h of 10–20-day-old females, approximately 2 h after the beginning of photophase. Mating resulted in termination of the pheromone release in both mealybug species. The temporal flight activity of the males was monitored in rearing chambers using pheromone baited delta traps. Males of both P. citri and P. ficus displayed the same flight pattern and began flying at 06:00 hours when the light was turned on, reaching a peak during the first and second hour of the photophase. Our results suggest that other biparental mealybug species display also diel periodicities of maximal pheromone release and response. Direct evaluation of the diel periodicity of the pheromone release by the automatic sequential analysis is convenient and will be very helpful in optimizing the airborne collection and identification of other unknown mealybug pheromones and to study the calling behavior of females. Considering this behavior pattern may help to develop more effective pheromone-based management strategies against mealybugs.     

Is there a double-dividend from anti-sprawl policies?

This paper examines the welfare effects of anti-sprawl policies, such as development tax, in a simple spatial explicit urban model with two market failures - urban decline at the city core and underprovision of open space amenities at the urban fringe - and pre-existing distortionary property tax, used to fund public services and improvements to mitigate urban decline. Consistent with prior double-dividend literature, there is a tax interaction effect that occurs between the development tax and the pre-existing property tax. However, there are two fundamental differences between the tax interaction effect identified here and that of prior literature. Ours one has two components: First, there is a cost-side tax interaction effect that is ‘spatially’ concentrated at the urban fringe, as only agents at the urban fringe alter their behavior in response to the development tax. Second, there is also a benefit-side tax interaction effect, as increases in open space at the urban fringe are capitalized into housing prices throughout the city. In contrast to prior literature, we find that the empirical importance of the combined tax interaction effect is of substantially less importance and, as a consequence, the likelihood of a ‘double-dividend’ is higher than in prior studies. Further, we show that the development tax should be part of the local tax system, even in the absence of open space benefits.     

Human bioaccessibility of Cr, Cu, Ni, Pb and Zn in urban soils from the city of Torino, Italy

Several physiologically based extraction procedures have been proposed to estimate the fraction of the potentially toxic element content that would be bioaccessible in the human gastro-intestinal tract following accidental ingestion of soil. Many of these procedures are complex, they have been applied to a very limited range of soils, and most work has focussed on arsenic and lead. In the present study, a simplified, two-stage extraction, simulating the human stomach and intestine, was developed and applied to urban soil samples from ten public-access areas in the City of Torino, Italy. The human oral bioaccessibility of chromium, copper, nickel, lead and zinc was estimated. Lead and zinc bioaccessibilities were found to be higher in the stomach, but chromium was more bioaccessible in the intestine. Analyte concentrations were higher in roadside soils than in soils from parks. A higher proportion of the soil metal content was found in bioaccessible forms at roadsides than in parks. Comparison of the current findings with results of earlier work involving sequential extraction of the same soils indicated that the sequential procedure gave a relative, but not an absolute, indication of bioaccessibility. Calculations based on the bioaccessible analyte concentrations suggest that ingestion of only 2–3 g of some of the roadside soil samples from Torino could deliver the tolerable daily oral intake of chromium, nickel and lead to a 20-kg child. The developed procedure is useful for preliminary screening of soils and prediction of whether their bioaccessible metal contents are likely to pose a risk to human health.     

2,2',4,4'-四溴联苯醚的好氧微生物降解

从北京高碑店污水处理厂活性污泥中筛选出1株能好氧降解2,2’,4,4’-四溴联苯醚(BDE-47)的细菌,并对其降解特性及有关蛋白质进行分析,目的是了解好氧条件下BDE-47的微生物降解机制.BDE-47降解菌通过平板划线法获得,其16S rDNA与不动杆菌(Acintobacter sp.)的相似度最大,为90%.采用250 mL锥形瓶研究了所得菌对BDE-47的降解情况,在BDE-47初试浓度为146μg.L-1的条件下,经过63 d的培养,所得菌降解了45.44%的BDE-47,降解产物主要为4-OH-联苯醚,菌量增加了7倍左右.分别以BDE-47和酵母提取物为碳源培养所得菌2周,然后各自提取蛋白质,通过蛋白质双向电泳及质谱检测,发现了与BDE-47降解有关的一些特异蛋白质.本研究表明,在好氧条件下,细菌可以BDE-47为碳源生长,其过程涉及多种蛋白质的作用.     

Ecological consistency across space: a synthesis of the ecological aspects of Dromiciops gliroides in Argentina and Chile

Dromiciops gliroides is an arboreal marsupial found in the temperate forests of South America (36–43 °S). This species is the sole extant representative of the order Microbiotheria, and is a key seed disperser of many native plant species, including the keystone mistletoe Tristerix corymbosus. Here, we synthesized the current knowledge on the ecological aspects of this species, and compared the available information from Argentina and Chile. Population density (23?±?2 (mean ± SE) individual/ha) and home range (1.6?±?0.6?ha) appear to be relatively similar across a marked ecological gradient in the mainland, but lower densities (7?±?2 individual/ha) and smaller home ranges (0.26?±?0.04?ha) were detected at island sites. We detected regional variation in body condition in Chile, but there were no significant differences across a wider E-W gradient. Movement patterns fit a random walk model; such behavior might have important consequences in shaping plant’s spatial patterns. Although our data suggest that D. gliroides is more tolerant to habitat disturbance than previously thought, its incapability to disperse across non-forested areas suggests that the rapid rate of habitat loss and fragmentation that characterizes southern temperate forests likely poses a serious threat to this species. These ecological similarities are surprising given that forests studied receive dramatically different rainfall and correspond to distinct forest types. The evidence synthetized here dispels some of the myths about this species but also stresses the need for more comprehensive ecological studies across its distribution range.     

Transforming pods of the species Capparis flexuosa into effective biosorbent to remove blue methylene and bright blue in discontinuous and continuous systems

Environmental Science and Pollution Research - This study investigates, for the first time, the applicability of seed pods from Capparis flexuosa as an alternative biosorbent to remove methylene...     

Pervaporation of ethanol produced from banana waste

Banana waste has the potential to produce ethanol with a low-cost and sustainable production method. The present work seeks to evaluate the separation of ethanol produced from banana waste (rejected fruit) using pervaporation with different operating conditions. Tests were carried out with model solutions and broth with commercial hollow hydrophobic polydimethylsiloxane membranes. It was observed that pervaporation performance for ethanol/water binary mixtures was strongly dependent on the feed concentration and operating temperature with ethanol concentrations of 1–10%; that an increase of feed flow rate can enhance the permeation rate of ethanol with the water remaining at almost the same value; that water and ethanol fluxes was increased with the temperature increase; and that the higher effect in flux increase was observed when the vapor pressure in the permeate stream was close to the ethanol vapor pressure. Better results were obtained with fermentation broth than with model solutions, indicated by the permeance and membrane selectivity. This could be attributed to by-products present in the multicomponent mixtures, facilitating the ethanol permeability. By-products analyses show that the presence of lactic acid increased the hydrophilicity of the membrane. Based on this, we believe that pervaporation with hollow membrane of ethanol produced from banana waste is indeed a technology with the potential to be applied.     

Effective antibacterial and antioxidant properties of methanolic extract of Laurus nobilis seed oil

This study was carried out to determine the in vitro antimicrobial and antioxidant activities of the essential oil, seed oil, and methanolic extract of seed oil obtained from Laurus nobilis L. (Lauraceae). The methanolic extract of seed oil exhibited more effective antibacterial activity comparing to essential oil and seed oil, GC-MS analyses of the essential oil resulted in the identification of 25 compounds. 1.8-Cineol (44.72%), a-Terpinyl acetate (12.95%), Sabinene (12.82%) were the main components. The fatty acid composition was characterized with the high content of linoleic acid (40.79%) and lauric acid (38.08%). The 50% (IC50) inhibition activity of the essential oil on the free radical DPPH was determined as 94.655 mg ml(-1), whereas IC50 value of methanolic extract of seed oil was found unstable. In the case of the linoleic acid system, oxidation of linoleic acid was inhibited by essential oil and methanolic extract of seed oil, which showed 64.28 and 88.76% inhibition, respectively. The inhibition value of the methanolic extract of seed oil was quite close to the synthetic antioxidant BHT, 92.46% inhibition.