An Introduction to the Chalk Aquifers of Northern Europe

We briefly outline the progressive development of approaches to both the characterization and simulation of the hydrogeology of northern European chalk aquifers, which were some of the first in the world to be studied. The volume's scope includes work on water resources and quality, chalk streams and wetland ecosystems, chalks as heat reservoirs for building temperature regulation, sources of groundwater flood risk and impacts of engineering on the subsurface, and diffuse and point-source pollution affecting these aquifers. It excludes hydrocarbon-related studies and those focused on offshore chalk sequences. We briefly outline the current state of knowledge of hydrogeological processes, characterization, assessment and modelling, and the increasingly recognized importance of karst features. The latter were little discussed 20 years ago and are still often neglected. There follows a brief quantitative analysis of publication topics relating to chalk hydrogeology in the scientific literature over the past three decades, which highlights key trends including both the purposes of studies and the methods employed. We present a summary of the topics and contributions within this volume, and conclude by identifying the key issues that need to be addressed in order to ensure the sustainability of our chalk aquifers for the future

D-cycloserine-augmented one-session treatment of specific phobias in children and adolescents.

BACKGROUND: D-Cycloserine has potential to enhance exposure therapy outcomes. The current study presents a preliminary randomized, placebo-controlled double-blind pilot trial of DCS-augmented one-session treatment (OST) for youth (7-14 years) with specific phobia. A secondary aim of this pilot study was to explore the effects of youth age and within-session fear reduction as potential moderators of DCS outcomes in order to generate hypotheses for a larger trial. It was hypothesized that DCS would be associated with greater improvements than placebo, that children (7-10 years) would have greater benefits than adolescents (11-14 years), and that DCS effects would be stronger for participants with the greater within-session fear reduction during the OST. METHODS: Thirty-five children and adolescents were randomized to either OST combined with DCS (n = 17), or OST combined with placebo (PBO; n = 18) and assessed at 1 week, 1 month, and 3 month following treatment. RESULTS: There were no significant pre- to post-treatment or follow-up benefits of DCS relative to placebo. Secondary analyses of age indicated that relative to PBO, DCS was associated with greater improvements for children (but not adolescents) on measures of severity at 1-month follow-up. Children in the DCS condition also showed significantly greater improvement to 1 month on global functioning relative to other groups. Conversely, adolescents had significant post-treatment benefits in the PBO condition on symptom severity measures relative to DCS, and adolescents in the DCS condition had significantly poorer functioning at 3 months relative to all other groups. Finally, there was a trend for within-session fear reduction to be associated with moderating effects of DCS, whereby greater reduction in fear was associated with greater functioning at one-month follow-up for children who received DCS, relative to PBO. LIMITATIONS: The study sample was small and therefore conclusions are tentative and require replication. CONCLUSIONS: Age and within-session fear reduction may be important moderators of DCS-augmented one-session exposure therapy, which requires testing in a fully powered randomized controlled trial

Can acoustic radiation force imaging of the liver and spleen predict the presence of gastroesophageal varices?

Aim To determine whether acoustic radiation force imaging (ARFI) of the liver/spleen could be used in patients with cirrhosis to predict the presence of gastroesophageal varices (GOVs). Materials and methods Fifty-eight patients with cirrhosis who were undergoing 6-monthly ultrasound examinations for hepatoma surveillance and who were due to have oesophagogastroduodenoscopy (OGD) within 6 months of their ultrasound were recruited. During routine ultrasound, the patient's liver and spleen were also assessed using ARFI. Other clinical parameters (platelet count, spleen size, and transient elastography measurements) were also collected. Logistic regression was used to determine which variables were significantly associated with presence or absence of varices univariably and multivariably Results Fourteen patients (24%) had GOVs. Patients with GOVs had higher ARFI measurements in the liver and spleen than patients without GOVs (liver: 2.39 versus 2.13, spleen: 2.89 versus 2.82), but these results were not statistically significant (odds ratio=1.75, 95% confidence interval [CI]=0.82, 3.91 and odds ratio=1.12, 95% CI=0.33, 3.97, respectively). The platelet/splenic ratio, in comparison, was associated with the presence or absence of GOVs in multivariate analysis (odds ratio=0.32, 95% CI=0.008, 0.91). Conclusion Although patients with GOVs had overall higher ARFI liver and spleen results, this was not statistically significant. As such, ARFI cannot yet replace OGD in predicting GOVs in this patient group

Sea-level constraints on the amplitude and source distribution of Meltwater Pulse 1A.

During the last deglaciation, sea levels rose as ice sheets retreated. This climate transition was punctuated by periods of more intense melting; the largest and most rapid of these—Meltwater Pulse 1A—occurred about 14,500 years ago, with rates of sea-level rise reaching approximately 4 m per century1, 2, 3. Such rates of rise suggest ice-sheet instability, but the meltwater sources are poorly constrained, thus limiting our understanding of the causes and impacts of the event4, 5, 6, 7. In particular, geophysical modelling studies constrained by tropical sea-level records1, 8, 9 suggest an Antarctic contribution of more than seven metres, whereas most reconstructions10 from Antarctica indicate no substantial change in ice-sheet volume around the time of Meltwater Pulse 1A. Here we use a glacial isostatic adjustment model to reinterpret tropical sea-level reconstructions from Barbados2, the Sunda Shelf3 and Tahiti1. According to our results, global mean sea-level rise during Meltwater Pulse 1A was between 8.6 and 14.6 m (95% probability). As for the melt partitioning, we find an allowable contribution from Antarctica of either 4.1 to 10.0 m or 0 to 6.9 m (95% probability), using two recent estimates11, 12 of the contribution from the North American ice sheets. We conclude that with current geologic constraints, the method applied here is unable to support or refute the possibility of a significant Antarctic contribution to Meltwater Pulse 1A

Takeovers and cooperatives: governance and stability in non-corporate firms

Author's draft dated 11 January 2010. Final version published in Journal of economics available online at http://www.springerlink.com/If consumers wholly or partially control a firm with market power they will charge less than the profit maximizing price. Starting at the usual monopoly price, a small price reduction will have a second order effect on profits but a first order effect on consumer surplus. Despite this desirable static result, it has been argued that cooperatives are vulnerable to take-over by outsiders who will run them as for-profit businesses. This paper studies takeovers of cooperatives. We argue that there will not be excessive takeovers of cooperatives due to the Grossman-Hart problem of free riding during takeovers.Research in part supported by ESRC grant RES-000-22-0650

Norbornene probes for the study of cysteine oxidation

Cysteine residues on proteins can react with cellular oxidants such as hydrogen peroxide. While this process is important for scavenging excess reactive oxygen species, the products of this oxidation may also mediate cell signalling. To understand the role of cysteine oxidation in biology, selective probes are required to detect and quantify its occurence. Cysteine oxidation products such as sulfenic acids are sometimes unstable and therefore short-lived. If such cysteine derivatives are to be analysed, rapid reaction with the probe is required. Here we introduce norbornene derivatives as probes for cysteine oxidation, and demonstrate their ability to trap sulfenic acids. The synthesis of norbornene derivatives containing alkyne or biotin affinity tags are also reported to facilitate the use of these probes in chemical biology and proteomics

Communicating genetic information: a difficult challenge for future pediatricians

<p>Abstract</p> <p>Background</p> <p>The role of the pediatrician as genetic counselor is ideal because pediatricians have medical knowledge and experience with genetic disorders (e.g. Down syndrome). Moreover, pediatricians can provide comprehensive care in a medical home to patients with genetic disorders. However, changes in the curriculum of the pediatric resident are necessary to address the future challenges of effectively communicating genetic information to patients. The objective of this study was to explore these challenges and make recommendations for training to adequately prepare pediatricians for their future role as genetic counselors.</p> <p>Methods</p> <p>Three reviewers independently searched PubMed, OVID, and Medline databases to identify articles describing the challenges of communicating genetic information to patients, published from 1960 to December 2005. After the publications were identified and reviewed, four major areas of interest were identified in order to categorize the findings.</p> <p>Results</p> <p>Twenty-five publications were identified during the literature search. From the review, the following categories were selected to organize the findings: (1) Inherent difficulties of communicating and comprehending genetic information; (2) Comprehension of genetic information by pediatricians; (3) Genetics training in residency programs; and (4) The effect of genetic information on the future role of pediatricians and potential legal implications.</p> <p>Conclusion</p> <p>Pediatricians and residents lack essential knowledge of genetics and communication skills for effective counseling of patients. The review indicated that successful communication of genetic information involves a number of important skills and considerations. It is likely that these skills and considerations are universally required for the communication of most complex specialized medical information. In the past, communication skills have not been considered a priority. Today, these skills have become a demanding professional and even legal obligation. However, the challenges involved in communicating complex medical information cannot be successfully addressed with universal, one-size-fits-all recommendations. Residency training programs require changes to adequately prepare future pediatricians for the growing challenge of communicating genetic information. Four important skills should be considered in the training of residents to improve the communication of complex information to patients. These skills are (1) discriminating, (2) understanding, (3) simplifying, and (4) explaining information.</p

Grids of stellar models with rotation: V. Models from 1.7 to 120 Msun at zero metallicity

Understanding the nature of the first stars is key to understanding the early universe. With new facilities such as JWST we may soon have the first observations of the earliest stellar populations, but to understand these observations we require detailed theoretical models. Here we compute a grid of stellar evolution models using the Geneva code with the aim to improve our understanding of the evolution of zero-metallicity stars, with particular interest in how rotation affects surface properties, interior structure, and metal enrichment. We produce a range of models of initial masses (Mini) from 1.7 Msun to 120 Msun, focusing on massive models of 9 Msun 60 Msun reach critical rotation on the main sequence and experience mass loss. We find that rotational mixing strongly affects metal enrichment, but does not always increase metal production as we see at higher metallicities. This is because rotation leads to an earlier CNO boost to the H shell during He-burning, which may hinder metal enrichment depending on initial mass and rotational velocity. Electronic tables of this new grid of Population III models are publicly available

A meta-analytic review of stand-alone interventions to improve body image

Objective Numerous stand-alone interventions to improve body image have been developed. The present review used meta-analysis to estimate the effectiveness of such interventions, and to identify the specific change techniques that lead to improvement in body image. Methods The inclusion criteria were that (a) the intervention was stand-alone (i.e., solely focused on improving body image), (b) a control group was used, (c) participants were randomly assigned to conditions, and (d) at least one pretest and one posttest measure of body image was taken. Effect sizes were meta-analysed and moderator analyses were conducted. A taxonomy of 48 change techniques used in interventions targeted at body image was developed; all interventions were coded using this taxonomy. Results The literature search identified 62 tests of interventions (N = 3,846). Interventions produced a small-to-medium improvement in body image (d+ = 0.38), a small-to-medium reduction in beauty ideal internalisation (d+ = -0.37), and a large reduction in social comparison tendencies (d+ = -0.72). However, the effect size for body image was inflated by bias both within and across studies, and was reliable but of small magnitude once corrections for bias were applied. Effect sizes for the other outcomes were no longer reliable once corrections for bias were applied. Several features of the sample, intervention, and methodology moderated intervention effects. Twelve change techniques were associated with improvements in body image, and three techniques were contra-indicated. Conclusions The findings show that interventions engender only small improvements in body image, and underline the need for large-scale, high-quality trials in this area. The review identifies effective techniques that could be deployed in future interventions

Expression and Membrane Topology of Anopheles gambiae Odorant Receptors in Lepidopteran Insect Cells

A lepidopteran insect cell-based expression system has been employed to express three Anopheles gambiae odorant receptors (ORs), OR1 and OR2, which respond to components of human sweat, and OR7, the ortholog of Drosophila's OR83b, the heteromerization partner of all functional ORs in that system. With the aid of epitope tagging and specific antibodies, efficient expression of all ORs was demonstrated and intrinsic properties of the proteins were revealed. Moreover, analysis of the orientation of OR1 and OR2 on the cellular plasma membrane through the use of a novel ‘topology screen’ assay and FACS analysis demonstrates that, as was recently reported for the ORs in Drosophila melanogaster, mosquito ORs also have a topology different than their mammalian counterparts with their N-terminal ends located in the cytoplasm and their C-terminal ends facing outside the cell. These results set the stage for the production of mosquito ORs in quantities that should permit their detailed biochemical and structural characterization and the exploration of their functional properties