Differential release of sewage sludge biochar-borne elements by common low-molecular-weight organic acids

Biochar materials originated from sewage sludge may contain elevated levels of potentially toxic elements. There was a lack of information on the mobility of biochar-borne elements, as driven by lowmolecular-weight organic acids (LMWOAs) contained in plant root exudates. A batch experiment was conducted to examine the effects of three common LMWOAs on the release of major elements and trace elements with a focus on various potentially toxic trace elements. The results showed that substantial amounts of Al, Mn, Fe, K, Na and Mg were extracted from two sewage sludge-derived biochar materials by the LMWOAs. A much higher release rate of potentially toxic trace elements was observed in the presence of LMWOAs, as compared to reported data using extractants not encountered in root exudates. The LMWOA-driven releasibility of various potentially toxic trace elements was in the following decreasing order: Zn > Ni > Pb > Cu > Cr > Co = Cd. Other trace elements that are subject to mobilization in the presence of LMWOAs included B, Ba, In, Li and Sr except Ba under oxalic acid extraction. Among the three LMWOAs, oxalic acid showed a generally stronger capacity to mobilize these metals. The findings obtained from this study provides new information that can be used for better evaluating the phyto-availability of trace elements bound to sewage sludge-originated biochar materials

New-onset seizures in older people: Clinical features, course and outcomes

OBJECTIVE: The incidence of epilepsy increases with age. With current demographic trends, this presents a healthcare challenge. We investigated the clinical spectrum of first seizures, evaluated neuroimaging and EEG findings, and determined clinical outcomes, including anti-seizure medication (ASM) response in older people. In addition, we sought to understand the relative effects of age and frailty on ASM response. METHODS: A retrospective single centre cohort study of 207 cases ≥60 years' old, 113 of whom were eventually diagnosed with a first seizure in a specialist epilepsy clinic. RESULTS: 65/113 (57.5%) presented with either focal aware or focal impaired awareness seizures. Stroke was the most common aetiological association (31.9%, 36/113), and odds of seizure recurrence did not significantly differ between aetiologies. 55/86 (64.0%) who started an ASM had no seizure recurrence. 14/48 (29.2%) who underwent EEG had epileptiform abnormalities, however EEG result directly affected management in only 4/48 (8.3%). The most common MRI findings were small vessel disease (37/93, 39.8%), stroke (27/93, 29.0%) and global atrophy (14/93, 15.1%). Increasing age and frailty did not affect the odds of seizure recurrence or of experiencing ASM side effects. Severity of small vessel disease or atrophy did not affect odds of seizure recurrence. CONCLUSION: Our data inform the management of first seizures in older people and provisionally support the use of ASMs in patients with increasing age and frailty, despite concerns over polypharmacy and comorbidity. Our findings should be replicated in larger cohorts

The effects of biochar on trace element and nutrient solubility in the presence of low-molecular-weight organic acids

Low-molecular-weight organic acids (LMWOAs) secreted by plant roots play an essential role in regulating the phytoavailability of soil-borne trace elements and nutrients. Biochar is widely considered as a suitable soil remediation option, having shown an efficacy to retain both anions and cations. This study aims to unravel the roles of LMWOAs in affecting the functioning of biochar in aqueous and soil systems. Twelve biochar were characterised and rice husk biochar was selected for use. Firstly, aqueous batch experiments examined the biochar-driven immobilisation of trace elements and nutrients with and without LMWOAs. Then, batch studies tested if biochar would reduce the LMWOA-driven solubilisation of trace elements and nutrients in soil. Later, rice husk biochar and LMWOA-activated rice husk biochar were incorporated in greenhouse investigations to study the growth parameters of edible plant species and trace element uptake by pea (Pisum sativum). Solution sorption studies found that LMWOAs impeded the biochar-driven removal of cadmium and lead but enhanced nitrate removal. Biochar did not affect phosphate removal. Biochar inhibited the LMWOA-driven solubilisation of soil-borne cadmium and zinc. Nitrate immobilisation was not enhanced but biochar reduced the immobilisation of the added nitrate overall. Phosphate immobilisation was observed but was caused by the precipitation of practically insoluble phosphate minerals using biochar as a source of soluble calcium. Seven out of eleven trace elements accumulated in pea roots were reduced either by biochar and LMWOA-activated biochar but the uptake was variable with biochar type. The data obtained indicate LMWOAs complicate biochar functioning in solution and soil under the studied conditions. Based on the results, protonation of the biochar materials in acidic conditions impeded cation immobilisation whilst enhancing nitrate immobilisation. Acid neutralisation by the biochar materials likely reduced the LMWOA-solubilisation of trace elements which would affect trace element uptake by plants such as pea, within biochar-amended soils

Effects of softwood biochar on the status of nitrogen species and elements of potential toxicity in soils

The effects of softwood-derived biochar materials on the chemical behaviour of environmental contaminants in soils were examined in two microcosm scenarios. Addition of the biochar materials into an alkaline sandy soil significantly reduced NH3 volatilization and made it available for conversion into NO3- via nitrification. This process could be enhanced by an increased application rate of biochar produced at a higher pyrolysis temperature. Under the alkaline conditions encountered in the experiment, the biochar surfaces tended to be negatively charged which disfavours the adsorption of NO3-. Therefore, in a fully open system, the addition of biochar materials was likely to contribute to nitrate leaching from the fertilized alkaline sandy soil. The effects of the biochar materials on the immobilization of Fe2+ generated via anaerobic iron reduction in the inundated contaminated soil were not observed, except for the treatment with a higher dose of biochar material produced under pyrolysis temperature at 700°C after the 240th h of incubation. Arsenic showed similar behaviour to Fe. Zn tended to have a higher affinity to the biochar, as compared to Mn. Immobilization of Pb occurred regardless of whether or not the biochar is present

An autoencoder-based reduced-order model for eigenvalue problems with application to neutron diffusion

Using an autoencoder for dimensionality reduction, this paper presents a novel projection-based reduced-order model for eigenvalue problems. Reduced-order modelling relies on finding suitable basis functions which define a low-dimensional space in which a high-dimensional system is approximated. Proper orthogonal decomposition (POD) and singular value decomposition (SVD) are often used for this purpose and yield an optimal linear subspace. Autoencoders provide a nonlinear alternative to POD/SVD, that may capture, more efficiently, features or patterns in the high-fidelity model results. Reduced-order models based on an autoencoder and a novel hybrid SVD-autoencoder are developed. These methods are compared with the standard POD-Galerkin approach and are applied to two test cases taken from the field of nuclear reactor physics.Comment: 35 pages, 33 figure

Assessment of the U.S. Department of Energy's Home Energy Scoring Tool

The National Renewable Energy Laboratory (NREL) conducted a series of assessments of the U.S. Department of Energy's (DOE) proposed Home Energy Scoring Tool (HEST). This report is an assessment of the 4/27/2012 release of HEST. Predictions of electric and natural gas consumption were compared with weather-normalized utility billing data for a mixture of newer and older homes located in Oregon, Wisconsin, Minnesota, North Carolina and Texas

"Remember Everything": things past in Station Island

Book synopsis: Seamus Heaney: Poet, Critic, Translator explores the range of Heaney's writing, emphasizing significant intersections in his work - meeting places; spaces between; tradition meeting the contemporary context as life meets death; liminal poetic representations and political divisions; town and woods, absence and presence; inner reality facing external reality; the timely and the transcendent; region and wider world; Irish tradition encountering Polish tradition; the space between modern English and ancient Greek; the meeting of personal and formal in the translation of Beowulf; different times and perceptions meeting problematic memory; Heaney's Leavisite stance in the face of contemporary critical currents; and Heaney's imagination approaching the imaginations of other poets

A new simplified protocol for copper(I) alkyne–azide cycloaddition reactions using low substoichiometric amounts of copper(II) precatalysts in methanol

Copper(II) carboxylates are reduced efficiently by methanol in the presence of alkynes and form yellow alkynylcopper(I) polymeric precatalysts that are involved with azides, in the absence of added ligands, in the catalytic cycles that result in the formation of 1,4-disubstituted 1,2,3-triazoles

Tea and coffee consumption in relation to vitamin D and calcium levels in Saudi adolescents

Background Coffee and tea consumption was hypothesized to interact with variants of vitamin D-receptor polymorphisms, but limited evidence exists. Here we determine for the first time whether increased coffee and tea consumption affects circulating levels of 25-hydroxyvitamin D in a cohort of Saudi adolescents. Methods A total of 330 randomly selected Saudi adolescents were included. Anthropometrics were recorded and fasting blood samples were analyzed for routine analysis of fasting glucose, lipid levels, calcium, albumin and phosphorous. Frequency of coffee and tea intake was noted. 25-hydroxyvitamin D levels were measured using enzyme-linked immunosorbent assays. Results Improved lipid profiles were observed in both boys and girls, as demonstrated by increased levels of HDL-cholesterol, even after controlling for age and BMI, among those consuming 9–12 cups of coffee/week. Vitamin D levels were significantly highest among those consuming 9–12 cups of tea/week in all subjects (p-value 0.009) independent of age, gender, BMI, physical activity and sun exposure. Conclusion This study suggests a link between tea consumption and vitamin D levels in a cohort of Saudi adolescents, independent of age, BMI, gender, physical activity and sun exposure. These findings should be confirmed prospectively