Suggestions to the article: medical professionalism research characteristics and hotspots

Scientometrics - The article published on 5 July 2021 is well-written and of interest. However, some improvements could be made, such as ten Tables/Figures can be shortened to highlight the focused...     

Threshold privacy-preserving cloud auditing with multiple uploaders

International Journal of Information Security - Data integrity is a critical security issue in cloud storage. The data integrity checking schemes by a third-party auditor (TPA) have attracted a lot...     

Floc-based sequential partial nitritation and anammox at full scale with contrasting N2O emissions

New Activated Sludge (NAS^®) is a hybrid, floc-based nitrogen removal process without carbon addition, based on the control of sludge retention times (SRT) and dissolved oxygen (DO) levels. The aim of this study was to examine the performance of a retrofitted four-stage NAS^® plant, including on-line measurements of greenhouse gas emissions (N₂O and CH₄). The plant treated anaerobically digested industrial wastewater, containing 264 mg N L⁻¹, 1154 mg chemical oxygen demand (COD) L⁻¹ and an inorganic carbon alkalinity of 34 meq L⁻¹. The batch-fed partial nitritation step received an overall nitrogen loading rate of 0.18-0.22 kg N m⁻³ d⁻¹, thereby oxidized nitrogen to nitrite (45-47%) and some nitrate (13-15%), but also to N₂O (5.1-6.6%). This was achieved at a SRT of 1.7 d and DO around 1.0 mg O₂ L⁻¹. Subsequently, anammox, denitrification and nitrification compartments were followed by a final settler, at an overall SRT of 46 d. None of the latter three reactors emitted N₂O. In the anammox step, 0.26 kg N m⁻³ d⁻¹ was removed, with an estimated contribution of 71% by the genus Kuenenia, which constituted 3.1% of the biomass. Overall, a nitrogen removal efficiency of 95% was obtained, yielding a dischargeable effluent. Retrofitting floc-based nitrification/denitrification with carbon addition to NAS^® allowed to save 40% of the operational wastewater treatment costs. Yet, a decrease of the N₂O emissions by about 50% is necessary in order to obtain a CO₂ neutral footprint. The impact of emitted CH₄ was 20 times lower.     

Microbially mediated phosphine emission

There is still a lot of controversy in literature concerning the question whether a biochemical system exists enabling micro-organisms to reduce phosphate to phosphine gas. The search for so-called 'de novo synthesised' phosphine is complicated by the fact that soils, slurries, sludges, etc., which are often used as inocula, usually contain matrix bound phosphine (MBP). Matrix bound phosphine is a general term used to indicate non-gaseous reduced phosphorus compounds that are transformed into phosphine gas upon reaction with bases or acids. A study was carried out to compare the different digestion methods, used to transform matrix bound phosphine into phosphine gas. It was demonstrated that caustic and acidic digestion methods should be used to measure the matrix bound phosphine of the inoculum prior to inoculation to avoid false positive results concerning de novo synthesis. This is especially true if anthropogenically influenced inocula possibly containing minute steel or aluminium particles are used. The comparative study on different digestion methods also revealed that the fraction of phosphorus in mild steel, converted to phosphine during acid corrosion depended on the temperature. Following these preliminary studies, anaerobic growth experiments were set up using different inocula and media to study the emission of phosphine gas. Phosphine was detected in the headspace gases and its quantity and timeframe of emission depended on the medium composition, suggesting microbially mediated formation of the gas. The amount of phosphine emitted during the growth experiments never exceeded the bound phosphine present in inocula, prior to inoculation. Hence, de novo synthesis of phosphine from phosphate could not be demonstrated. Yet, microbially mediated conversion to phosphine of hitherto unknown reduced phosphorus compounds in the inoculum was evidenced.     

Advanced water treatment with manganese oxide for the removal of 17alpha-ethynylestradiol (EE2)

Municipal wastewater is supposed to be one of the most important sources of endocrine-disrupting compounds (EDCs) in water. Therefore, advanced treatments and cost-efficient techniques should be developed to prevent the spread of this type of pollution into the environment. In this view, experiments were conducted in which the removal of 17alpha-ethynylestradiol (EE2), a synthetic and persistent estrogen, from water was monitored in three upstream bioreactors (UBRs), filled with, respectively, sand, granulated activated carbon (GAC) and MnO(2) granules. Tap water, spiked with 15,000ngEE2/L was filtered through the reactors with a hydraulic retention time of approximately 1h. The removal of EE2 in the sand, GAC and MnO(2) reactors was, respectively, 17.3%,>99.8% and 81.7%. The removal in the GAC reactor was mainly due to adsorption. The MnO(2) reactor, however, removed significantly more EE2 than could be predicted from its adsorption capacity, probably thanks to its catalytic properties. These catalytic properties could make it a cost-efficient technique for the removal of EE2, but further research at more environmentally relevant concentrations is needed.     

Certificateless designated verifier signature revisited: achieving a concrete scheme in the standard model

International Journal of Information Security - In a designated verifier signature (DVS) scheme, the signer (Alice) creates a signature which is only verifiable by a designated verifier (Bob)....     

Motivational profiles from a self-determination perspective: The quality of motivation matters.

The present research complements extant variable-centered research that focused on the dimensions of autonomous and controlled motivation through adoption of a person-centered approach for identifying motivational profiles. Both in high school students (Study 1) and college students (Study 2), a cluster analysis revealed 4 motivational profiles: a good quality motivation group (i.e., high autonomous, low controlled); a poor quality motivation group (i.e., low autonomous, high controlled); a low quantity motivation group (i.e., low autonomous, low controlled); and a high quantity motivation group (i.e., high autonomous, high controlled). To compare the 4 groups, the authors derived predictions from qualitative and quantitative perspectives on motivation. Findings generally favored the qualitative perspective; compared with the other groups, the good quality motivation group displayed the most optimal learning pattern and scored highest on perceived need-supportive teaching. Theoretical and practical implications of the findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strategies to optimize phosphate removal from industrial anaerobic effluents by magnesium ammonium phosphate (MAP) production

BACKGROUND: Owing to more stringent phosphate discharge requirements and the increasing prices of fertilizers, beneficial recovery and reuse of phosphate from industrial anaerobic effluents is becoming an important issue. Phosphate recovery by struvite or magnesium ammonium phosphate (MAP) permits its recycling in the fertilizer industry because struvite is a valuable slow release fertilizer. Two different approaches to MAP crystallization depending on initial levels of phosphate in the wastewaters were tested and compared. RESULTS: For low‐phosphate‐containing anaerobic effluents (<30 mg PO₄^3?‐P L^?1), a novel approach using ureolytic induced MAP formation with MgO addition appeared to be suitable. The residual phosphate concentrations in the effluent ranged from 5 to 7 mg PO₄^3?‐P L^?1 and the separated matter contained residual amounts of Mg(OH)₂. High‐phosphate‐containing anaerobic effluents (100 to 120 mg PO₄^3?‐P L^?1) were treated efficiently using air stripping combined with MgCl₂ and NaOH reagents, yielding residual phosphate levels of 8 to 15 mg PO₄^3?‐P L^?1 and spherical pure MAP crystals of 0.5 to 2 mm. CONCLUSION: Results show that depending on the initial phosphate concentrations in the wastewaters and the ammonium and magnesium levels, the strategy selected for struvite crystallization is a determinative factor in achieving a cost effective technology. Copyright © 2008 Society of Chemical Industry