Screening of organic contaminants in urban snow

Snowmelt is known to cause peak concentrations of pollutants, which may adversely affect receiving water quality. High concentrations of metals and suspended solids in snow have been reported, whereas studies on organic pollutants are rare. This study aims at investigating the occurrence of anthropogenic organic compounds in urban snow in Gothenburg (Sweden). The most frequently detected organic pollutants in the collected snow samples were polycyclic aromatic hydrocarbons (PAHs), high molecular-weight phthalates, 4-nonylphenol and 4-t-octylphenol. Brominated flame retardants and chlorinated paraffins were only sporadically detected. In several snow samples, the concentrations of specific PAHs, alkylphenols and phthalates were higher than reported stormwater concentrations and European water quality standards. Pollutant source identification and sustainable management of snow are important instruments for the mitigation of organic contaminants in the urban environment.     

The good,the bad,and the algae: Perceiving ecosystem services and disservices generated by zebra and quagga mussels

Dreissenid (zebra and quagga) mussels are widely recognized as having strong, adverse ecological and economic impacts, e.g., biofouling and loss of water column primary production. We assessed perceptions and values associated with two less often considered ecological outcomes of dreissenid mussel influences on coastal ecosystems along Lake Ontario and the western St. Lawrence River in New York State. One, the generation of water clarity through filtration, we define as an ecosystem service; the other, the production of large amounts of nuisance algae (e.g., Cladophora and Microcystis) is defined as an ecosystem disservice. Surveys of business owners and homeowners quantified their preferences and the formation of values regarding these products of zebra mussel influence. Water clarity increased greatly, particularly in the eastern portion of Lake Ontario, and algal problems increased throughout. Businesses attributed increases and decreases in revenues associated with water clarity and algae; homeowners reported analogous changes in property values. Water clarity was positively associated, and algae negatively associated, with changes in revenues and property values. Threshold responses of costs as functions of filamentous algae were evident. Given the likely continued influx of invasive species due to human activities, further development of the ecosystem service concept should consider potential “goods” and “bads” of invasives and their influence on ecosystem and social system resiliency.     

A Fully Automated Process Using a Magnetic Particle Based Kit for Removal of Dye Terminators from Sequencing Reactions

Prolinx,® Inc. of Bothell, WA has developed the RapXtract™ 384 Dye Terminator Removal Kit for full automation of DNA sequencing reaction purification. The RapXtract product line is based upon proprietary superparamagnetic particle technology that eliminates the need for centrifugation, vacuum filtration, or modified primers to achieve purification of sequencing reactions. The kit described here is pre-dispensed in a 384-well microtiter plate and run on the TECAN GENESIS Workstation 150 (Tecan U.S. Inc., Research Triangle Park, NC). This system enables rapid purification of up to 384 sequencing reactions in a single run.As the completion of the Human Genome Project nears, it is imperative for biotechnology and pharmaceutical companies to increase throughput of DNA sequencing in order to be competitive in the drug discovery and validation process. The “race to market” requires a shift from standard DNA sequencing processes-including DNA sequencing reaction purification-towards complete walk-away automation for all steps.Existing sequencing reaction purification methods (Table 1) require considerable resources including: plastic and other laboratory consumables; specialized equipment, such as high-speed centrifuges or vacuum filtration apparatus; and labor-intensive protocols requiring large amounts of technician time. As a result, walk-away automation of standard purification methods is difficult and expensive.     

Charakterisierung des quasilinearen Raumes I(R) und Klassifizierung der quasilinearen Räume der Dimension 1 und 2

In this paper we investigate the quasilinear spacesQ with dimQ≤2 and characterize the special role of the quasilinear space I(R), the space of all compact intervals overR.     

Gas chromatographic separation of linoleic acid hydroperoxides as trimethylsilyl ethers of methyl hydroxystearates

The primary products, 9- and 13-hydroperoxy-octadecadienoic acids, from lipoxygenase catalyzed oxidation of linoleic acid, were converted into the trimethylsilyl ethers of methyl 9- and 13-hydroxystearates which were completely separated by gas chromatography on an OV-17 methyl silicone (50% phenyl groups), capillary column.     

The determination of diffusion coefficients in activated carbons made from bituminous coal

The gas chromatographic method has been used to measure the effective diffusion coefficients D_e or the diffusion parameters $\text{D}{}_{\mathrm{e}}\text{d}{}^2$. Nitrogen was used as a carrier gas, krypton-85 as test gas. The tests were carried out on different activated carbons made from air-preoxidized bituminous coals whose pore structure as a function of the burn-off was known. The diffusion parameters for krypton were found to increase exponentially with the mean micropore diameter of the activated carbons which was varied in our tests between 5.8 and 7.0 Å. For activated carbon with the narrowest pores the activation energy of krypton diffusion was found to be 2.8 kcal/mol. In case of such a product the diffusion time is not rigidly dependent on the particle diameter as would have to be expected theoretically. With increasing micropore diameter this dependency is attenuated very rapidly, and in carbons with a mean micropore diameter above ca. 6.8 Å it exists no longer at all. To check the results, gravimetric studies on the adsorption kinetics of krypton in vacua and on the desorption kinetics using the gas flushing method were made. It was found that the results obtained by the gas chromatographic method and the gas flushing method were in good agreement, whereas the diffusion parameters obtained by measurements in vacuo were by one order of magnitude lower. The findings are discussed in relation to the pore structure of the adsorbent and the properties of the sorbate. The limits of the different measuring methods are shown.     

Do work technique and musculoskeletal symptoms differ between men and women performing the same type of work tasks?

Musculoskeletal disorders are more common among women than among men. When comparing the difference between men and women in the prevalence of musculoskeletal disorders, methodological problems arise as men and women seldom perform the same type of activities, neither at work nor at home.

The main objective of this cross-sectional case study was to compare work technique and self-reported musculoskeletal symptoms between men and women performing the same type of work tasks within a metal industry. Other factors, such as leisure activities, were also taken into consideration. Three data collection methods were used; questionnaire, interviews and systematic observations. The results from the observations revealed that women worked more frequently and during longer times with their hands above shoulder height than men. Working with hands above shoulder height is considered a risk factor for neck and shoulder disorders according to previous studies. Workplace design factors were probably a reason for differences in working technique between men and women. A higher proportion of women than men reported shoulder symptoms. Women spent more time on household activities than men, which indicates a higher total workload in paid and unpaid work.     

Is there more to complicated grief than depression and posttraumatic stress disorder? A test of incremental validity.

There is growing interest in complicated grief reactions as a possible new diagnostic category for inclusion in the Diagnostic and Statistical Manual of Mental Disorders. However, no research has yet shown that complicated grief has incremental validity (i.e., predicts unique variance in functioning). The authors addressed this issue in 2 studies by comparing grief, depression, and posttraumatic stress disorder (PTSD) symptoms with different measures of functioning (interviewer ratings, friend ratings, self-report, and autonomic arousal). The 1st study (N = 73) used longitudinal data collected at 4 and 18 months postloss, and the 2nd study (N = 447) used cross-sectional data collected 2.5-3.5 years postloss. With depression and PTSD controlled, grief emerged as a unique predictor of functioning, both cross-sectionally and prospectively. The findings provide convergent support for the incremental validity of complicated grief as an independent marker of bereavement-related psychopathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)