Polycyclic Aromatic Hydrocarbons in Urban Stream Sediments

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants of high environmental concern with known carcinogenic activity. Although literature documents PAH fate in urban runoff, little is known about their distribution on sediment sizes, which is essential for determining their treatability and fate in receiving waters. This paper has quantified the concentrations of selected PAHs in urban creek sediments and examined possible relationships between sediment PAH content and sediment characteristics, such as particle size, volatile organic content (VOC), and sediment chemical oxygen demand (SCOD). SCOD, VOC, and PAH concentrations of sediments showed a bimodal distribution by particle size. The large diameter sediments had the highest VOC and also had the highest PAH concentrations. The spatial variation of PAH content by sediment sizes also was statistically significant; however, the mass of the PAH material was significantly affected by the relative abundance of the different particle size classes in the sediment mixtures

Analyses of PAHs in Urban Stormwater Particulates

Abstract: Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants of concern in many receiving waters. The transport and fate of PAHs in the environment depends primarily on their physical and chemical properties and the reactivity of the compound. A fugacity calculation method presented b

Cryptic Eimeria genotypes are common across the southern but not northern hemisphere

The phylum Apicomplexa includes parasites of medical, zoonotic and veterinary significance. Understanding the global distribution and genetic diversity of these protozoa is of fundamental importance for efficient, robust and long-lasting methods of control. Eimeria spp. cause intestinal coccidiosis in all major livestock animals and are the most important parasites of domestic chickens in terms of both economic impact and animal welfare. Despite having significant negative impacts on the efficiency of food production, many fundamental questions relating to the global distribution and genetic variation of Eimeria spp. remain largely unanswered. Here, we provide the broadest map yet of Eimeria occurrence for domestic chickens, confirming that all the known species (Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox, Eimeria tenella) are present in all six continents where chickens are found (including 21 countries). Analysis of 248 internal transcribed spacer sequences derived from 17 countries provided evidence of possible allopatric diversity for species such as E. tenella (FST values ⩽0.34) but not E. acervulina and E. mitis, and highlighted a trend towards widespread genetic variance. We found that three genetic variants described previously only in Australia and southern Africa (operational taxonomic units x, y and z) have a wide distribution across the southern, but not the northern hemisphere. While the drivers for such a polarised distribution of these operational taxonomic unit genotypes remains unclear, the occurrence of genetically variant Eimeria may pose a risk to food security and animal welfare in Europe and North America should these parasites spread to the northern hemisphere

Quantum Statistics and Entanglement of Two Electromagnetic Field Modes Coupled via a Mesoscopic SQUID Ring

In this paper we investigate the behaviour of a fully quantum mechanical system consisting of a mesoscopic SQUID ring coupled to one or two electromagnetic field modes. We show that we can use a static magnetic flux threading the SQUID ring to control the transfer of energy, the entanglement and the statistical properties of the fields coupled to the ring. We also demonstrate that at, and around, certain values of static flux the effective coupling between the components of the system is large. The position of these regions in static flux is dependent on the energy level structure of the ring and the relative field mode frequencies, In these regions we find that the entanglement of states in the coupled system, and the energy transfer between its components, is strong.Comment: 15 pages, 19 figures, Uploaded as implementing a policy of arXiving old paper

Get screened: a pragmatic randomized controlled trial to increase mammography and colorectal cancer screening in a large, safety net practice

Abstract Background Most randomized controlled trials of interventions designed to promote cancer screening, particularly those targeting poor and minority patients, enroll selected patients. Relatively little is known about the benefits of these interventions among unselected patients. Methods/Design "Get Screened" is an American Cancer Society-sponsored randomized controlled trial designed to promote mammography and colorectal cancer screening in a primary care practice serving low-income patients. Eligible patients who are past due for mammography or colorectal cancer screening are entered into a tracking registry and randomly assigned to early or delayed intervention. This 6-month intervention is multimodal, involving patient prompts, clinician prompts, and outreach. At the time of the patient visit, eligible patients receive a low-literacy patient education tool. At the same time, clinicians receive a prompt to remind them to order the test and, when appropriate, a tool designed to simplify colorectal cancer screening decision-making. Patient outreach consists of personalized letters, automated telephone reminders, assistance with scheduling, and linkage of uninsured patients to the local National Breast and Cervical Cancer Early Detection program. Interventions are repeated for patients who fail to respond to early interventions. We will compare rates of screening between randomized groups, as well as planned secondary analyses of minority patients and uninsured patients. Data from the pilot phase show that this multimodal intervention triples rates of cancer screening (adjusted odds ratio 3.63; 95% CI 2.35 - 5.61). Discussion This study protocol is designed to assess a multimodal approach to promotion of breast and colorectal cancer screening among underserved patients. We hypothesize that a multimodal approach will significantly improve cancer screening rates. The trial was registered at Clinical Trials.gov NCT00818857http://deepblue.lib.umich.edu/bitstream/2027.42/78264/1/1472-6963-10-280.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78264/2/1472-6963-10-280.pdfPeer Reviewe

Argumentation in school science : Breaking the tradition of authoritative exposition through a pedagogy that promotes discussion and reasoning

The value of argumentation in science education has become internationally recognised and has been the subject of many research studies in recent years. Successful introduction of argumentation activities in learning contexts involves extending teaching goals beyond the understanding of facts and concepts, to include an emphasis on cognitive and metacognitive processes, epistemic criteria and reasoning. The authors focus on the difficulties inherent in shifting a tradition of teaching from one dominated by authoritative exposition to one that is more dialogic, involving small-group discussion based on tasks that stimulate argumentation. The paper builds on previous research on enhancing the quality of argument in school science, to focus on how argumentation activities have been designed, with appropriate strategies, resources and modelling, for pedagogical purposes. The paper analyses design frameworks, their contexts and lesson plans, to evaluate their potential for enhancing reasoning through foregrounding the processes of argumentation. Examples of classroom dialogue where teachers adopt the frameworks/plans are analysed to show how argumentation processes are scaffolded. The analysis shows that several layers of interpretation are needed and these layers need to be aligned for successful implementation. The analysis serves to highlight the potential and limitations of the design frameworks

Radio observations of Circinus X-1 over a complete orbit at an historically faint epoch

We present results from the first radio observations of a complete orbit (~ 17 days) of the neutron star X-ray binary Circinus X-1 using the Australia Telescope Compact Array Broadband Backend, taken while the system was in an historically faint state. We have captured the rapid rise and decline of a periastron passage flare, with flux densities for 9 days prior to the event stable at ~ 1 mJy at 5.5 GHz and ~ 0.5 mJy at 9 GHz. The highest flux densities of 43.0 +/- 0.5 mJy at 5.5 GHz and 29.9 +/- 0.6 mJy at 9 GHz were measured during the flare's decline (MJD 55206.69) which continues towards pre-flare flux densities over the following 6 days. Imaging of pre-flare data reveals steady structure including two stable components within 15 arc-seconds of the core which we believe may be persistent emission regions within the system's outflows, one of which is likely associated with the system's counter-jet. Unlike past observations carried out in the system's brighter epochs, we observe no significant structural variations within \approx 3 arc-seconds of the core's position. Model subtraction and difference mapping provide evidence for variations slightly further from the core: up to 5" away. If related to the observed core flare, then these variations suggest very high outflow velocities with {\Gamma} > 35, though this can be reduced significantly if we invoke phase delays of at least one orbital period. Interestingly, the strongest structural variations appear to the north west of the core, opposite to the strongest arcsec-scale emission historically. We discuss the implications of this behaviour, including the possibility of precession or a kinked approaching jet.Comment: Accepted for publication in MNRA

Identification of Homogentisate Dioxygenase as a Target for Vitamin E Biofortification in Oilseeds

Soybean (Glycine max) is a major plant source of protein and oil and produces important secondary metabolites beneficial for human health. As a tool for gene function discovery and improvement of this important crop, a mutant population was generated using fast neutron irradiation. Visual screening of mutagenized seeds identified a mutant line, designated MO12, which produced brown seeds as opposed to the yellow seeds produced by the unmodified Williams 82 parental cultivar. Using forward genetic methods combined with comparative genome hybridization analysis, we were able to establish that deletion of the GmHGO1 gene is the genetic basis of the brown seeded phenotype exhibited by the MO12 mutant line. GmHGO1 encodes a homogentisate dioxygenase (HGO), which catalyzes the committed enzymatic step in homogentisate catabolism. This report describes to our knowledge the first functional characterization of a plant HGO gene, defects of which are linked to the human genetic disease alkaptonuria. We show that reduced homogentisate catabolism in a soybean HGO mutant is an effective strategy for enhancing the production of lipid-soluble antioxidants such as vitamin E, as well as tolerance to herbicides that target pathways associated with homogentisate metabolism. Furthermore, this work demonstrates the utility of fast neutron mutagenesis in identifying novel genes that contribute to soybean agronomic traits

Effectiveness and cost-effectiveness of a telehealth intervention to support the management of long-term conditions: study protocol for two linked randomized controlled trials

Background: As the population ages, more people are suffering from long-term health conditions (LTCs). Health services around the world are exploring new ways of supporting people with LTCs and there is great interest in the use of telehealth: technologies such as the Internet, telephone and home self-monitoring. Methods/Design: This study aims to evaluate the effectiveness and cost-effectiveness of a telehealth intervention delivered by NHS Direct to support patients with LTCs. Two randomized controlled trials will be conducted in parallel, recruiting patients with two exemplar LTCs: depression or raised cardiovascular disease (CVD) risk. A total of 1,200 patients will be recruited from approximately 42 general practices near Bristol, Sheffield and Southampton, UK. Participants will be randomly allocated to either usual care (control group) or usual care plus the NHS Direct Healthlines Service (intervention group). The intervention is based on a conceptual model incorporating promotion of self-management, optimisation of treatment, coordination of care and engagement of patients and general practitioners. Participants will be provided with tailored help, combining telephone advice from health information advisors with support to use a range of online resources. Participants will access the service for 12 months. Outcomes will be collected at baseline, four, eight and 12 months for the depression trial and baseline, six and 12 months for the CVD risk trial. The primary outcome will be the proportion of patients responding to treatment, defined in the depression trial as a PHQ-9 score <10 and an absolute reduction in PHQ-9 ≥5 after 4 months, and in the CVD risk trial as maintenance or reduction of 10-year CVD risk after 12 months. The study will also assess whether the intervention is cost-effective from the perspective of the NHS and personal social services. An embedded qualitative interview study will explore healthcare professionals’ and patients’ views of the intervention. Discussion: This study evaluates a complex telehealth intervention which combines evidence-based components and is delivered by an established healthcare organisation. The study will also analyse health economic information. In doing so, the study hopes to address some of the limitations of previous research by demonstrating the effectiveness and cost-effectiveness of a real world telehealth interventio