Nano-Scale Hydroxyapatite: Synthesis, Two-Dimensional Transport Experiments, and Application for Uranium Remediation

Synthetic nano-scale hydroxyapatite (NHA) was prepared and characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods. The XRD data confirmed that the crystalline structure and chemical composition of NHA correspond to Ca5OH(PO4)3. The SEM data confirmed the size of NHA to be less than 50 nm. A two-dimensional physical model packed with saturated porous media was used to study the transport characteristics of NHA under constant flow conditions. The data show that the transport patterns of NHA were almost identical to tracer transport patterns. This result indicates that the NHA material can move with water like a tracer, and its movement was neither retarded nor influenced by any physicochemical interactions and/or density effects. We have also tested the reactivity of NHA with 1 mg/L hexavalent uranium (U(VI)) and found that complete removal of U(VI) is possible using 0.5 g/L NHA at pH 5 to 6. Our results demonstrate that NHA has the potential to be injected as a dilute slurry for in situ treatment of U(VI)-contaminated groundwater systems

Gravitational intraction on quantum level and consequences thereof

The notion of gravitational emission as an emission of the same level with electromagnetic emission is based on the proven fact of existence of electrons stationary states in its own gravitational field, characterized by gravitational constantComment: 22 pages, 9 figure

Phosphorus Release from Unamended and Gypsum- or Biochar-Amended Soils under Simulated Snowmelt and Summer Flooding Conditions

Prolonged flooding changes the oxidation–reduction status of soils, often enhancing P release to overlying floodwater. We studied P release from unamended, gypsum-amended, and biochar-amended soils under simulated snowmelt flooding (previously frozen, cold flooding at +4°C) and summer flooding (unfrozen, warm flooding at +22°C) using two soils, Fyala clay (FYL-Cl) and Neuenberg sandy loam (NBG-SL), from Manitoba, Canada. Amended and unamended soils were packed into vessels and flooded under cold and warm temperatures in the laboratory. Pore water and floodwater samples were taken weekly for 6 wk after flooding (WAF) and thereafter biweekly for 10 WAF and analyzed for dissolved reactive P (DRP), pH, and cation concentrations. The NBG-SL showed a significantly higher DRP concentration in pore water and floodwater despite its low Olsen P content. Redox potential (Eh) decreased slowly under cold versus warm flooding; hence, redox-induced P release was substantially lower under cold flooding. Gypsum amendment significantly decreased the floodwater DRP concentrations in NBG-SL by 38 and 35% under cold and warm flooding, respectively, but had no significant effect in FYL-Cl, which had low DRP concentrations (<1.2 mg L−1) throughout the flooding period. Biochar amendment significantly increased floodwater DRP concentrations by 27 to 68% in FYL-Cl under cold and warm flooding, respectively, but had no significant effect in NBG-SL. The results indicate substantially less P release under cold than under warm flooding. Gypsum was effective in reducing floodwater DRP concentrations only at high DRP concentrations; thus, the effectiveness was greater under warm than under cold flooding conditions."Funding for this research was provided by a National Sciences and Engineering Research Council (NSERC) Discovery Grant and a University of Winnipeg Major Grant to Darshani Kumaragamage, and a fellowship awarded by the University of Winnipeg–Queen Elizabeth Advanced Scholar Program to R.S. Dharmakeerthi."https://acsess.onlinelibrary.wiley.com/doi/10.2134/jeq2019.02.009

Feasibility and Evaluation of Surgical Simulation with Developed Crisis Scenarios: A Comparison of Performance by Vascular Surgery Training Paradigms

OBJECTIVES: Surgical simulation is an integral component of training and has become increasingly vital in the evaluation and assessment of surgical trainees. Simulation proficiency determination has been traditionally based on accuracy and time to completion of various simulated tasks, but we were interested in assessing clinical judgment during a simulated crisis scenario. This study assessed the feasibility of creating a crisis simulator station for vascular surgery and evaluated the performance of vascular surgery integrated residents (0+5) and vascular surgery fellows (5+2) during a technical testing with an integrated crisis scenario. METHODS: A Modified Delphi method was used to create vascular surgery crisis simulation stations containing a clinical scenario in conjunction with either an open or endovascular simulator. Senior level vascular surgery trainees from both integrated residencies (0+5) and traditional vascular surgery fellowships (5+2) were then evaluated on two simulation stations: 1) Elective carotid endarterectomy (CEA) where the crisis is a postoperative stroke and 2) Endovascular aneurysm repair (EVAR) for a ruptured abdominal aortic aneurysm (rAAA). Each simulation had a crisis scenario incorporated into the procedure. Assessment was completed using a performance assessment tool containing a Likert scale. Total score was calculated as a percentage. Scores were also sub-divided in the following four categories: Situation Recognition and Decision-making, Procedural Flow, Technical Skills, and Interpretation and Use of Imaging Skills. Student\u27s t-test was used for analysis. RESULTS: 40 senior-level trainees were evaluated (27 fellows and 13 integrated residents) completing 80 simulations. The CEA crisis simulation yielded similar results between both groups (0+5 vs. 5+2, p = 1.00). The 0+5 residents in vascular surgery were graded to be more proficient in the EVAR for rAAA crisis simulation and demonstrated significant differences in Total Score (p = 0.04), Procedural Flow (p=0.03), and Interpretation and Use of Imaging Skills (p = 0.02). CONCLUSIONS: The creation of crisis-based simulation for trainees in vascular surgery is feasible and actionable. Integrated 0+5 residents performed similarly to 5+2 fellows on an open carotid endarterectomy (CEA) crisis simulation, but 0+5 residents scored significantly higher compared to traditional 5+2 fellows in an endovascular rAAA crisis simulation. Crisis simulation may offer better educational experiences and improved value compared to routine simulation. Further studies using different procedural models and clinical scenarios are needed to assess the validity of crisis simulation in vascular surgery and to better understand the performance disparities found between these training paradigms

A Logic with Reverse Modalities for History-preserving Bisimulations

We introduce event identifier logic (EIL) which extends Hennessy-Milner logic by the addition of (1) reverse as well as forward modalities, and (2) identifiers to keep track of events. We show that this logic corresponds to hereditary history-preserving (HH) bisimulation equivalence within a particular true-concurrency model, namely stable configuration structures. We furthermore show how natural sublogics of EIL correspond to coarser equivalences. In particular we provide logical characterisations of weak history-preserving (WH) and history-preserving (H) bisimulation. Logics corresponding to HH and H bisimulation have been given previously, but not to WH bisimulation (when autoconcurrency is allowed), as far as we are aware. We also present characteristic formulas which characterise individual structures with respect to history-preserving equivalences.Comment: In Proceedings EXPRESS 2011, arXiv:1108.407

Entrepreneurs’ age, institutions, and social value creation goals: a multi-country study

This study explores the relationship between an entrepreneur's age and his/her social value creation goals. Building on the lifespan developmental psychology literature and institutional theory, we hypothesize a U-shaped relationship between entrepreneurs’ age and their choice to create social value through their ventures, such that younger and older entrepreneurs create more social value with their businesses while middle age entrepreneurs are relatively more economically and less socially oriented with their ventures. We further hypothesize that the quality of a country’s formal institutions in terms of economic, social, and political freedom steepen the U-shaped relationship between entrepreneurs’ age and their choice to pursue social value creation as supportive institutional environments allow entrepreneurs to follow their age-based preferences. We confirm our predictions using multilevel mixed-effects linear regressions on a sample of over 15,000 entrepreneurs (aged between 18 and 64 years) in 45 countries from Global Entrepreneurship Monitor data. The findings are robust to several alternative specifications. Based on our findings, we discuss implications for theory and practice, and we propose future research directions

Quality and thermal characterization of glutenin-rich fractions of wheat flour (Triticum aestivum) obtained by different extraction methods

Wheat gluten is mainly responsible for the structural characteristics of bakery products. When studying wheat proteins, it is important to use reliable extraction methods. Four different methods of wheat protein extraction were studied, with emphasis on the glutenin-rich fractions. The final quality of the protein fractions was evaluated in terms of denaturation, indirect yield, molecular weight, secondary structure, and thermal profile. Our results indicate that addition of dithiothreitol improves glutenin extraction without interfering with protein secondary structure and denaturation. Different thermal profiles were evidenced for different extraction methods, indicating the selectivity of the processes. Denaturation temperatures of the samples showed differences within about 3 °C, while denaturation enthalpies (ΔH) differed by about 14 kJ µg−1. Data in this paper may provide a broader perspective on how wheat proteins are affected by the extraction method

Blueberry Progress Reports

The 1978 edition of the Blueberry Progress Reports was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers with the Maine Life Sciences and Agriculture Experiment Station and Maine Cooperative Extension Service at the University of Maine, Orono. Projects in this report include: 1. Weed Control in Blueberry Fields 2. Pruning of Blueberries 3. Integrated Management of Blueberry Fields 4. Factors Regulating Rhizome Initiation and Development in the Lowbush Blueberry 5. Effect of Plant-Water Stress on Lowbush Blueberry Growth Yield and Quality 6. Blossom Blight of Blueberries 7. Botrytis Blossom Blight of Lowbush Blueberries 8. Insects Affecting the Blueberry 9. Treatment of Blueberries with Potassium Sorbate to Reduce Spoilage During Temporary Storage 10. Cooperative Extension Activitie