Pesticide removal from cotton farm tailwater by a pilot-scale ponded wetland

A pilot-scale, ponded wetland consisting of an open pond and a vegetated pond in series was constructed on a cotton farm in northern New South Wales, Australia, and assessed for its potential to remove pesticides from irrigation tailwater. Ten incubation periods ranging from 7 to 13 days each were conducted over two cotton growing seasons to monitor removal of residues of four pesticides applied to the crop. Residue reductions ranging 22–53% and 32–90% were observed in the first and second seasons respectively. Average half-lives during this first season were calculated as 21.3 days for diuron, 25.4 days for fluometuron and 26.4 days for aldicarb over the entire wetland. During the second season of monitoring, pesticide half-lives were significantly reduced, with fluometuron exhibiting a half-life of 13.8 days, aldicarb 6.2 days and endosulfan 7.5 days in the open pond. Further significant reductions were observed in the vegetated pond and also following an algal bloom in the open pond, as a result of which aldicarb and endosulfan were no longer quantifiable. Partitioning onto sediment was found to be a considerable sink for the insecticide endosulfan. These results demonstrate that macrophytes and algae can reduce the persistence of pesticides in on-farm water and provide some data for modelling.     

Extraction properties of new polymeric sorbents in SPE/GC analysis of phenol and hydroquinone from water samples

The influence of the polymers' properties on the solid-phase extraction recovery was studied. Different porous copolymers were used: di(methacryloyloxymethyl)naphtalene-divinylbenzene with ester functional groups (DMN-DVB), 4,4'-bis(maleimido)diphenylmethane-divinylbenzene with imide functional groups (BM-DVB), p,p'-dihydroxydiphenylmethane diglycidyl methacrylic ester-divinylbenzene (MEMDE-DVB) and p,p'-dihydroxydiphenylpropane diglycidyl methacrylic ester-divinylbenzene (MEDDE-DVB) with ester end hydroxyl functional groups. The extraction properties of new synthesized polymeric sorbents were compared with these of two commercial polymeric sorbents: styrene-divinylbenzene (SDB-1) and styrene-divinylbenzene with modified surface (StrataX). These sorbents were used in the SPE of phenol and hydroquinone from water samples.     

Humpback whale song: who sings?

While on their winter breeding grounds, male humpback whales (Megaptera novaeangliae) produce long sequences of structured vocalizations called song, whose function within the mating system is still unresolved. Here we ask which males sing. Is it only those sexually mature, as typifies songbirds and some lekking ungulates in which vocalizations during the rut are restricted to mature males? Or do immature males join in the chorus? Using an underwater videogrammetric technique, we measured the body lengths of 87 humpback singers in the Hawaiian winter grounds. Applying length and sexual maturity relationships for North Pacific humpbacks as determined by biologists aboard twentieth century Japanese whaling vessels, we found that singer lengths ranged from 10.7 to 13.6 m, with 15 % of lengths indicative of probable sexual immaturity (length?<?11.3 m, p [maturity]?<?0.5). We interpret this broad participation of males as a lekking aggregation and the asynchronous singing chorus as an instance of by-product mutualism. The participation of many singers yields a heightened signal level that may attract more females to the singing area. Sexually mature males can benefit through access to more females. Immature males may gain deferred benefits through increased opportunities to learn and practice the social, behavioral, and acoustical skills and conventions of the winter grounds that they can apply usefully in later years.     

Proactive career behaviors and subjective career success: The moderating role of national culture

Although career proactivity has positive consequences for an individual's career success, studies mostly examine objective measures of success within single countries. This raises important questions about whether proactivity is equally beneficial for different aspects of subjective career success, and the extent to which these benefits extend across cultures. Drawing on Social Information Processing theory, we examined the relationship between proactive career behaviors and two aspects of subjective career success—financial success and work‐life balance—and the moderating role of national culture. We tested our hypotheses using multilevel analyses on a large‐scale sample of 11,892 employees from 22 countries covering nine of GLOBE's 10 cultural clusters. Although we found that proactive career behaviors were positively related to subjective financial success, this relationship was not significant for work‐life balance. Furthermore, career proactivity was relatively more important for subjective financial success in cultures with high in‐group collectivism, high power distance, and low uncertainty avoidance. For work‐life balance, career proactivity was relatively more important in cultures characterized by high in‐group collectivism and humane orientation. Our findings underline the need to treat subjective career success as a multidimensional construct and highlight the complex role of national culture in shaping the outcomes of career proactivity.     

基于测试数据的室内超宽带信道建模研究

基于室内超宽带信道测量研究建立了基于簇的时延抽头模型以及与距离和载频有关的新颖的路径损耗模型,建立了路径损耗同时与距离和频率的依赖关系.同时,研究发现视距和非视距接收信号幅度分别满足莱斯和瑞利分布.该模型对超宽带无线系统仿真和设计有重要的指导意义.     

Ecotoxicological effects of an aged TiO2 nanocomposite measured as apoptosis in the anecic earthworm Lumbricus terrestris after exposure through water, food and soil

Titanium dioxide nanoparticles seem to have a low toxicity to terrestrial organisms, though few studies are published in this area. TiO(2) used in sunscreens are nanocomposites where TiO(2) has been coated with magnesium, silica or alumina, as well as amphiphilic organics like polydimethyl siloxane (PDMS), and these coatings are modified by ageing. We assessed the ecotoxicity and propensity for bioaccumulation of an aged TiO(2) nanocomposite used in sunscreen cosmetics, and its potential effect on the frequency of apoptosis in different earthworm tissues. The earthworm Lumbricus terrestris was exposed to the TiO(2) nanocomposite for 7 days in water or 2-8 weeks in soil with the nanocomposite mixed either into food or soil at concentrations ranging from 0 to 100 mg kg(-1). Apoptosis was then measured by immunohistochemistry and Ti localized by XRF microscopy. Results showed no mortality, but an enhanced apoptotic frequency which was higher in the cuticule, intestinal epithelium and chloragogenous tissue than in the longitudinal and circular musculature. TiO(2) nanoparticles did not seem to cross the intestinal epithelium/chloragogenous matrix barrier to enter the coelomic liquid, or the cuticule barrier to reach the muscular layers. No bioaccumulation of TiO(2) nanocomposites could thus be observed.     

Short-term dynamics and long-term relationship between natural gas consumption and economic growth in Nigeria: an ARDL approach with breaks

Environmental Science and Pollution Research - This paper investigates the short-term dynamics as well as the long-term relationship between natural gas consumption and economic growth in Nigeria,...     

Trace element pollution records in some UK lake sediments, their history, influence factors and regional differences

Sediment cores were taken from six sites across the UK. Apart from Banbury Reservoir in London, all the other sites are relatively remote lakes. Trace elements Pb, Zn, Cu, Cd, Cr, Ni, Sn, As and V, major elements such as Fe, Mn, Ti and Al were analysed, and organic content measured as loss-on-ignition was determined in all of these cores. The result shows that these relatively remote sites have experienced enhanced atmospheric deposition of anthropogenically derived trace elements for over 100 years, and the contamination might start before industrialisation. Trace metal contamination remains the highest level at Banbury Reservoir showing "pollution source" influence. Despite the considerable reduction in atmospheric deposition in recent years, although some of the element concentrations in the surface sediments have declined, they are still much higher than their natural background values. In these sites, trace element pollution records have been influenced by many different factors. Redox condition could affect As distribution in the sediments. Sediment matrix could also affect trace element pollution signal. Apart from direct atmospheric deposition, the distributions of trace elements in the sediments have been affected by forestry activities and catchment erosion, and more contaminated soil in-wash could increase sediment pollution whilst less contaminated soil could dilute sediment pollution. In some sites, data suggest that catchment in-wash is an important source of elements for the lakes.