Assessing mercury mobility in sediment of the Union Canal, Scotland, UK by sequential extraction and thermal desorption

The mobility of mercury (Hg) was assessed in sediment from the Union Canal, Scotland, UK. Samples collected from the vicinity of a former munitions factory that manufactured mercury fulminate detonators were subjected to sequential extraction followed by cold vapor atomic absorption spectrometry (CVAAS) and direct analysis using thermal desorption (TD). The sequential extraction indicated that > 75% of mercury (up to 429 mg kg −1 ) was in mobile forms, with 67% of the total Hg content was desorbed in the temperature range 100–250 °C consistent with species weakly attached to the mineral matrix [tentatively identified as an iron (oxy)hydroxide-associated species]. This predominance of mobile mercury species may arise from a lack of association between Hg and either organic matter or sulfur in the sediments. Further investigation of Hg mobilization, transport, and assimilation/biomagnification is required both to determine whether there is a need for remediation of the sediment and to improve understanding of the biogeochemical cycling of Hg in shallow, oxic, freshwater systems

G 112-29 (=NLTT 18149), a Very Wide Companion to GJ 282 AB with a Common Proper Motion, Common Parallax, Common Radial Velocity and Common Age

We have made a search for common proper motion (CPM) companions to the wide binaries in the solar vicinity. We found that the binary GJ 282AB has a very distant CPM companion (NLTT 18149) at a separation s=1.09 \arcdeg. Improved spectral types and radial velocities are obtained, and ages determined for the three components. The Hipparcos trigonometric parallaxes and the new radial velocities and ages turn out to be very similar for the three stars, and provide strong evidence that they form a physical system. At a projected separation of 55733AU from GJ 282AB, NLTT 18149 ranks among the widest physical companions known.Comment: 13 pages, 3 figures, submmited to Ap

Optimisation and application of a low cost, colorimetric screening method for mercury in marine sediment

A rapid, inexpensive, colorimetric screening method for mercury (Hg) has been optimised to provide a semi-quantitative measurement of Hg concentration in marine sediment within the range 0.038 to 1.5 mg kg-1 encompassing the interim sediment quality guideline (ISQG) value of 0.13 mg kg-1 (CCME 1999) and the probable effects level (PEL) of 0.7 mg kg-1 for Hg in marine sediment (CCME 1999). Neither salinity (up to 41 practical salinity units (psu)) nor sediment organic matter (ΟΜ) content (up to 10%) affected the performance of the method. Accurate results were obtained for spike recovery experiments and analysis of certified reference material (CRM) BCR 580 Estuarine Sediment. The method was applied to sediment samples from Elefsina Bay, Greece. Screening results indicated Hg contamination in the bay, with concentrations exceeding the PEL value. Findings were confirmed by quantitative analysis of the samples by cold vapour atomic absorption spectrometry (CV-AAS), where results in the range 1.4–2.96 mg kg-1 were determined

Cadherin-Mediated Differential Cell Adhesion Controls Slow Muscle Cell Migration in the Developing Zebrafish Myotome

AbstractSlow-twitch muscle fibers of the zebrafish myotome undergo a unique set of morphogenetic cell movements. During embryogenesis, slow-twitch muscle derives from the adaxial cells, a layer of paraxial mesoderm that differentiates medially within the myotome, immediately adjacent to the notochord. Subsequently, slow-twitch muscle cells migrate through the entire myotome, coming to lie at its most lateral surface. Here we examine the cellular and molecular basis for slow-twitch muscle cell migration. We show that slow-twitch muscle cell morphogenesis is marked by behaviors typical of cells influenced by differential cell adhesion. Dynamic and reciprocal waves of N-cadherin and M-cadherin expression within the myotome, which correlate precisely with cell migration, generate differential adhesive environments that drive slow-twitch muscle cell migration through the myotome. Removing or altering the expression of either protein within the myotome perturbs migration. These results provide a definitive example of homophilic cell adhesion shaping cellular behavior during vertebrate development

Study protocol of an investigation of attention and prediction error as mechanisms of action for latent inhibition of dental fear in humans

Background Evidence suggests that dental anxiety and phobia are frequently the result of direct associative fear conditioning but that pre-exposure to dental stimuli prior to conditioning results in latent inhibition of fear learning. The mechanisms underlying the pre-exposure effect in humans, however, are poorly understood. Moreover, pain sensitivity has been linked to dental fear conditioning in correlational investigations and theory suggests it may moderate the latent inhibition effect, but this hypothesis has not been directly tested. These gaps in our understanding are a barrier to the development of evidence-based dental phobia prevention efforts. Methods Healthy volunteers between the ages of 6 and 35 years will be enrolled across two sites. Participants will complete a conditioning task in a novel virtual reality environment, allowing for control over pre-exposure and the examination of behaviour. A dental startle (a brief, pressurized puff of air to a tooth) will serve as the unconditioned stimulus. Using a within-subjects experimental design, participants will experience a pre-exposed to-be conditioned stimulus, a non-pre-exposed to-be conditioned stimulus, and a neutral control stimulus. Two hypothesized mechanisms, changes in prediction errors and attention, are expected to mediate the association between stimulus condition and fear acquisition, recall, and retention. To ascertain the involvement of pain sensitivity, this construct will be measured through self-report and the cold pressor task. Discussion Dental phobia negatively affects the dental health and overall health of individuals. This study aims to determine the mechanisms through which pre-exposure retards conditioned dental fear acquisition, recall, and retention. A randomized control trial will be used to identify these mechanisms so that they can be precisely targeted and maximally engaged in preventative efforts

The Grizzly, November 21, 1980

Dean of Students\u27 Office Releases Vandalism Figures • Maintenance Working To Conserve Energy • Weight Room Relocated In Helfferich • College Union Attempts World\u27s Largest Molecule • Ursinus News In Brief: Espadas to speak today in Illinois; Maintenance planting new trees; Placement interviews coming soon • Rassias Method Explored for Languages • Journalism To Be Added To Curriculum • Medical Ethics Course Offered • Phil. & Rel. Dept. Lecture On Judaism • College To Host 43rd Messiah Performance • Foghat and Outlaws Perform for \u27Serious Rockers\u27 • Forum On Radiation Draws Mixed Views • Art Exhibit On Display In Wismer • Open House Planned By Astronomy Club • A Look At This Year\u27s Basketball Season • Cross Country To Compete In Nationals This Weekend • Gridders Lose Early Lead to Tie Gettysburghttps://digitalcommons.ursinus.edu/grizzlynews/1048/thumbnail.jp

Developing an intervention to facilitate family communication about inherited genetic conditions, and training genetic counsellors in its delivery.

Many families experience difficulty in talking about an inherited genetic condition that affects one or more of them. There have now been a number of studies identifying the issues in detail, however few have developed interventions to assist families. The SPRinG collaborative have used the UK Medical Research Council's guidance on Developing and Evaluating Complex Interventions, to work with families and genetic counsellors (GCs) to co-design a psycho-educational intervention to facilitate family communication and promote better coping and adaptation to living with an inherited genetic condition for parents and their children (<18 years). The intervention is modelled on multi-family discussion groups (MFDGs) used in psychiatric settings. The MFDG was developed and tested over three phases. First focus groups with parents, young people, children and health professionals discussed whether MFDG was acceptable and proposed a suitable design. Using evidence and focus group data, the intervention and a training manual were developed and three GCs were trained in its delivery. Finally, a prototype MFDG was led by a family therapist and co-facilitated by the three GCs. Data analysis showed that families attending the focus groups and intervention thought MFDG highly beneficial, and the pilot sessions had a significant impact on their family' functioning. We also demonstrated that it is possible to train GCs to deliver the MFDG intervention. Further studies are now required to test the feasibility of undertaking a definitive randomised controlled trial to evaluate its effectiveness in improving family outcomes before implementing into genetic counselling practice.The National Institute of Health Research funded the study but any views expressed do not necessarily reflect those of the Authority. Funded by NIHR reference number: RP-DG-1211-10015