Soil Stabilization with Polystyrene

This paper presents results of an investigation of the effect of polystyrene on the engineering properties of three soils. Use of a polystyrene-benzene solution as an admixture resulted in increased strength values. Satisfactory resistance to expansion and frost action was obtained with sandy and silty soils; unsatisfactory results were obtained with a clayey soil. Polystyrene stabilization is most effective with sandy soils; effectiveness decreases with increasing clay content. At present the method does not compare favorably with the economics of other available methods of stabilization

Changes in N-Transforming Archaea and Bacteria in Soil during the Establishment of Bioenergy Crops

Widespread adaptation of biomass production for bioenergy may influence important biogeochemical functions in the landscape, which are mainly carried out by soil microbes. Here we explore the impact of four potential bioenergy feedstock crops (maize, switchgrass, Miscanthus X giganteus, and mixed tallgrass prairie) on nitrogen cycling microorganisms in the soil by monitoring the changes in the quantity (real-time PCR) and diversity (barcoded pyrosequencing) of key functional genes (nifH, bacterial/archaeal amoA and nosZ) and 16S rRNA genes over two years after bioenergy crop establishment. The quantities of these N-cycling genes were relatively stable in all four crops, except maize (the only fertilized crop), in which the population size of AOB doubled in less than 3 months. The nitrification rate was significantly correlated with the quantity of ammonia-oxidizing archaea (AOA) not bacteria (AOB), indicating that archaea were the major ammonia oxidizers. Deep sequencing revealed high diversity of nifH, archaeal amoA, bacterial amoA, nosZ and 16S rRNA genes, with 229, 309, 330, 331 and 8989 OTUs observed, respectively. Rarefaction analysis revealed the diversity of archaeal amoA in maize markedly decreased in the second year. Ordination analysis of T-RFLP and pyrosequencing results showed that the N-transforming microbial community structures in the soil under these crops gradually differentiated. Thus far, our two-year study has shown that specific N-transforming microbial communities develop in the soil in response to planting different bioenergy crops, and each functional group responded in a different way. Our results also suggest that cultivation of maize with N-fertilization increases the abundance of AOB and denitrifiers, reduces the diversity of AOA, and results in significant changes in the structure of denitrification community

Consensus Recommendations for Clinical Outcome Assessments and Registry Development in Ataxias: Ataxia Global Initiative (AGI) Working Group Expert Guidance

To accelerate and facilitate clinical trials, the Ataxia Global Initiative (AGI) was established as a worldwide research platform for trial readiness in ataxias. One of AGI's major goals is the harmonization and standardization of outcome assessments. Clinical outcome assessments (COAs) that describe or reflect how a patient feels or functions are indispensable for clinical trials, but similarly important for observational studies and in routine patient care. The AGI working group on COAs has defined a set of data including a graded catalog of COAs that are recommended as a standard for future assessment and sharing of clinical data and joint clinical studies. Two datasets were defined: a mandatory dataset (minimal dataset) that can ideally be obtained during a routine clinical consultation and a more demanding extended dataset that is useful for research purposes. In the future, the currently most widely used clinician-reported outcome measure (ClinRO) in ataxia, the scale for the assessment and rating of ataxia (SARA), should be developed into a generally accepted instrument that can be used in upcoming clinical trials. Furthermore, there is an urgent need (i) to obtain more data on ataxia-specific, patient-reported outcome measures (PROs), (ii) to demonstrate and optimize sensitivity to change of many COAs, and (iii) to establish methods and evidence of anchoring change in COAs in patient meaningfulness, e.g., by determining patient-derived minimally meaningful thresholds of change

Comparative Accuracy and Cost-Effectiveness of Dynamic Contrast Enhanced Computed Tomography and Positron Emission Tomography in the Characterisation of Solitary Pulmonary Nodules

Abstract Introduction: Dynamic contrast-enhanced computed tomography (DCE-CT) and Positron Emission Tomography/Computed Tomography (PET/CT) have a high reported accuracy for the diagnosis of malignancy in solitary pulmonary nodules. The aim of this study was to compare the accuracy and cost-effectiveness of these. Methods: In this prospective multicentre trial, 380 participants with a solitary pulmonary nodule (8-30mm) and no recent history of malignancy underwent DCE-CT and PET/CT. All patients underwent either biopsy with histological diagnosis or completed CT follow-up. Primary outcome measures were sensitivity, specificity, and overall diagnostic accuracy for PET/CT and DCE-CT. Costs and cost-effectiveness were estimated from a healthcare provider perspective using a decision-model. Results: 312 participants (47% female, 68.1±9.0 years) completed the study, with 61% rate of malignancy at 2 years. The sensitivity, specificity, positive predictive value and negative predictive values for DCE-CT were 95.3% [95% CI 91.3;97.5], 29.8% [95% CI 22.3;38.4], 68.2% [95% CI 62.4%;73.5%] and 80.0% [95% CI 66.2;89.1] respectively, and for PET/CT were 79.1% [95% CI 72.7;84.2], 81.8% [95% CI 74.0;87.7], 87.3%[95% CI 81.5;91.5) and 71·2% [95% CI 63.2;78.1]. The area under the receiver operator characteristic curve (AUROC) for DCE-CT and PET/CT was 0.62 [95%CI 0.58;0.67] and 0.80 [95%CI 0.76;0.85] respectively (p<0.001). Combined results significantly increased diagnostic accuracy over PET/CT alone (AUROC=0.90 [95%CI 0.86;0.93], p<0.001). DCE-CT was preferred when the willingness to pay per incremental cost per correctly treated malignancy was below £9000. Above £15500 a combined approach was preferred. Conclusions: PET/CT has a superior diagnostic accuracy to DCE-CT for the diagnosis of solitary pulmonary nodules. Combining both techniques improves the diagnostic accuracy over either test alone and could be cost-effective. (Clinical trials.gov - NCT02013063)

Testing for mild explosivity and bubbles in LME non-ferrous metals prices

Figuerola-Ferretti thanks the Spanish Ministry of Education and Science for support under grants MICINN ECO2010-19357, ECO2012-36559 and ECO2013-46395, and McCrorie, The Carnegie Trust for the Universities of Scotland under grant no. 31935.This paper applies the mildly explosive/multiple bubbles testing methodology developed by Phillips, Shi and Yu (2015a, International Economic Review, forthcoming) to examine the recent time series behaviour of the main six London Metal Exchange (LME) non-ferrous metals prices. We detect periods of mild explosivity in the cash and three-month futures price series in each of copper, nickel, lead, zinc and tin, but not in aluminium. We argue that convenience yield, though the formal counterpart to dividend yield in commodity markets, is not a useful basis on which to assess whether observed explosivity is indicative of bubbles (namely, departures of prices from their fundamental values). We construct other measures that provide evidence that suggests the observed explosivity in the non-ferrous metals market can be associated with tight physical markets.PostprintPeer reviewe

To follow a rule?:On frontline clinicians’ understandings and embodiments of hospital-acquired infection prevention and control rules

This article reports on a study of clinicians’ responses to footage of their enactments of infection prevention and control. The study’s approach was to elicit clinicians’ reflections on and clarifications about the connections among infection control activities and infection control rules, taking into account their awareness, interpretation, and in situ application of those rules. The findings of the study are that clinicians responded to footage of their own IPC practices by articulating previously unheeded tensions and constraints including: infection control rules that were incomplete, undergoing change, and conflicting; material obstructions limiting infection control efforts; and habituated and divergent rule enactments and rule interpretations that were problematic but disregarded. The reflexive process is shown to elicit clinicians’ learning about these complexities as they affect the accomplishment of effective infection control. The process is further shown to strengthen clinicians’ appreciation of infection control as necessitating deliberation to decide what are locally appropriate standards, interpretations, assumptions, habituations and enactments of infection control. The article concludes that clinicians’ ‘practical wisdom’ is unlikely to reach its full potential without video-assisted scrutiny of and deliberation about in situ clinical work. This enables clinicians to anchor their in situ enactments, reasonings and interpretations to local agreements about the intent, applicability, limits and practical enactment of rules. Key words: video-reflexivity, rules, infection control, patient safety, embodied practice, practical wisdom, abductio

X-Ray Diffraction of Highway Materials

X-ray diffraction data during adsorption of water vapor on Na- and Ca-montmorillonites show that interlayer expansion is continuous but nonuniform. X-ray and adsorption isotherm data indicate an ice-like configuration of water molecules is completed with the fourth layer of interlayer water for the Ca-clay; a fifth layer intrudes to give a less ordered structure. Data for the Na-clay indicate a laminar stacking arrangement for up to three layers of interlayer water. The Na-clay adsorbs more than twice as much water and undergoes four times as large a volume change than the Ca-clay. The free energy change during adsorption of water vapor on the Ca-clay is nearly twice that for the Na-clay. Free energy changes with increasing relative pressure reflect interlayer expansion increments