Remediation Trials Research Articles

Streptomyces pactum addition to contaminated mining soils improved soil quality and enhanced metals phytoextraction by wheat in a green remediation trial

Streptomyces pactum (Act12), an agent of a gentle in situ remediation approach, has been recently used in few works in phytoextraction trials; however, the impact of Act12 on soil quality and metal phytoavailability has not been assessed in multi-metal contaminated soils. Consequently, here we assessed the potential impact of Act12 on the wheat (Triticum aestivum L.) growth, antioxidants activity, and the metal bioavailability in three industrial and mining soils collected from China and contained up to 118, 141, 339, and 6625 mg Cd, Cu, Pb, and Zn kg−1 soil, respectively. The Act12 was applied at 0 (control), 0.75 (Act-0.75), 1.50 (Act-1.5), and 2.25 (Act-2.25) g kg−1 (dry weight base) to the three soils; thereafter, the soils were cultivated with wheat (bio-indicator plant) in a pot experiment. The addition of Act12 (at Act-1.5 and Act-2.25) promoted wheat growth in the three soils and significantly increased the content of Cd, Cu, and Zn in the roots and shoots and Pb only in the roots (up to 121%). The Act12-induced increase in metals uptake by wheat might be attributed to the associated decrease in soil pH and/or the increase of metal chelation and production of indole acetic acid and siderophores. The Act12 significantly decreased the antioxidant activities and lipid peroxidation in wheat, which indicates that Act12 may mitigate metals stress in contaminated soils. Enhancing metals phytoextraction using Act12 is a promising ecofriendly approach for phytoremediation of metal-contaminated mining soils that can be safely utilized with non-edible plants and/or bioenergy crops.

What is normal cognition in depression? Prevalence and functional correlates of normative versus idiographic cognitive impairment.

Traditional neuropsychological assessment methods identify a subpopulation of individuals with Major Depressive Disorder (MDD) who demonstrate cognitive functioning below population norms. An even larger proportion of those with MDD self-report problems with cognition that interfere with daily roles and responsibilities. We aim to test whether an intraindividual deviation of cognitive functioning relative to premorbid estimates (idiographic impairment) may better characterize challenges for functional recovery in MDD. Adult participants with MDD (N = 111) who completed a baseline neuropsychological assessment battery for a cognitive remediation trial were used in analyses. We compared the frequency of cognitive impairment using the normative and idiographic approaches and examined how these indexes related to observed functioning, perceived functioning, and depression severity. While only 25% of the sample would be classified as cognitively impaired on a composite measure according to normative comparison standards, 62.2% of this group were classified as idiographically impaired using a conservative cut-off of at least 1 SD deviation below premorbid estimates. Idiographic cognitive impairment shared a stronger inverse relationship with perceived functional competence than normative cognitive impairment. Depressive symptoms did not significantly correlate with both normative and idiographic impairment. In MDD, reliance on assessment of contemporary cognitive functioning might underestimate rates of those who could be considered cognitively impaired. Consideration of idiographic impairment may help explain gaps between normatively defined cognitive ability with subjective complaints and disability in MDD. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

NEMATODE COLONIZATION OF PYRITE CINDER-POLLUTED SOIL

The nematofauna was studied in the early stages of a remediation trial at an industrial site where pyrite cinders had accumulated for 40 years in a large area and were then covered with mineral soil. The cinders were contaminated with several metals and metalloids. The soil of the experimental plots was derived from the mixture of cinders with the covering soil in a 1:1 ratio. Plots were amended with manure and sown with 3 metal resistant plants: Sorghum bicolor L., Helianthus annuus L., and Arundo donax L. Samples were taken : a) at the beginning of the trial on the pyrite cinders and covering soil, separately; b) from the mixture before the application of manure; c) from cultivated plots. Nematode communities were compared by using general composition, trophic structure, biodiversity and ecology indices. Nematofauna and other soil fauna were not detected in the pyrite cinders. Nematodes were recorded in the covering soil and after mixing with the cinders. In these early stages of the remediation process, amending and cropping increased nematode abundance and biodiversity compared to the initial situation of the pyrite cinders. The nematode community structures and all calculated indices showed an increase in the quality of the soil after the remediation process. Our results showed that phytoremediation brought about the repopulation of an extremely compromised area. Moreover, the analysis of nematofauna could be a useful tool for assessing the degree of soil disturbance and soil remediation

Mine spoil remediation via biochar addition to immobilise potentially toxic elements and promote plant growth for phytostabilisation

There are thousands of disused and abandoned mining sites around the world with substantial accumulations of exposed mine spoil materials that pose a direct threat to their surrounding environment. Management of such sites, and neutralisation of the environmental threats they pose, is therefore extremely important and is an issue of global significance. Low cost management and remediation strategies need to be developed because many abandoned mine sites are in remote and/or economically challenged areas. One promising option is the incorporation of biochar into spoil materials, which has the potential to immobilise leachable toxic constituents and facilitate revegetation and thereby stabilisation of spoil heaps. This study investigated the capacity of readily available biochar materials made from wheat and rice waste products to immobilise and retain key metallic contaminants Pb and Zn from solution, and also investigated the utility of biochar application for remediating mine spoil heaps from different mine types in terms of facilitating establishment of vegetation coverage and minimising porewater element mobility within spoil heaps. The results demonstrated the high sorption capacity of the biochars (typically >97% of Pb or Zn in solution) and their ability to retain the metals despite an active desorption procedure (>93% of sorbed Pb retained and >75% of sorbed Zn). The remediation trial revealed that biochar application increased plant yield and decreased plant assimilation of many potentially toxic elements and also decreased spoil porewater concentrations of Al, Cd, Pb and Zn in most cases. In some spoil types investigated biochar addition also significantly decreased porewater concentrations of As (e.g. from ~30 mg/L to ~5 mg/L), demonstrating its potential utility for low cost environmental remediation across a range of mine spoil types.

In situ arsenic immobilization by chemical oxidation: Field trial and reactive transport modelling

In situ chemical oxidation (ISCO) can be used as a technique for in situ arsenic (As) removal from groundwater. NaClO as an oxidant was intermittently injected into an anoxic aquifer with high aqueous As and Fe concentrations which is located on the Jianghan Plain (JHP). The aim was to promote the formation of hydrous ferric oxide (HFO) and oxidize arsenite to arsenate, thus immobilization aqueous arsenate via adsorption and/or co-precipitation. A three-dimensional reactive transport model was developed to determine the hydrogeochemical processes responsible for As (im)mobilization during the field trial. The modeling results indicate that the variation of AsO33− concentration can be divided into adsorption non-equilibrium and adsorption equilibrium stage. In adsorption non-equilibrium stage, oxidation and accompanying adsorption onto the surface of HFO causes the rapid decrease of AsO33− concentration. However, the modeled AsO33− concentrations were lower than measured concentrations in adsorption equilibrium stage, which may be due to AsO33− desorption from the surface of HFO as advantages of other competitive ions. Comparison of field data and modeling results suggest the product of the oxidative hydrolysis of Fe2+(aq) in the field experiment was ferrihydrite. The concentration of total As was mainly affected by the HFO content and concentration of competitive adsorption ions in groundwater. The natural groundwater flow field led to a difference in the concentration of HFO upstream and downstream of the injection well, where the downstream well had a higher HFO content and lower total As concentration. HCO3– was the dominant surface species affecting the adsorption of AsO43− by HFO. There is more sorption site on HFO surface due to the oxidation of adsorbed Fe2+, and then resulted in an increase in adsorbed H2SiO3(aq) and Mg2+(aq) content on the surface of the HFO over the course of the experiment. The reactive transport modeling (RTM) results reasonably match with observed concentrations of hydrochemical ions, indicating RTM can explain the crucial chemical processes in this in situ As remediation trial, providing important technical guidance for similar remediation operations.

Individual Alpha Peak Frequency Moderates Transfer of Learning in Cognitive Remediation of Schizophrenia.

Meta-analyses report moderate effects across cognitive remediation (CR) trials in schizophrenia. However, individual responses are variable, with some participants showing no appreciable gain in cognitive performance. Furthermore, reasons for heterogeneous outcome are undetermined. We examine the extent to which CR outcome is attributable to near learning-direct gains in trained cognitive tasks-while also exploring factors influencing far transfer of gains during training to external cognitive measures. Thirty-seven schizophrenia outpatients were classified as CR responders and non-responders according to change in MATRICS Consensus Cognitive Battery composite score following 20 sessions of computer-based training. Metrics of near learning during training, as well as baseline demographic, clinical, cognitive, and electroencephalographic (EEG) measures, were examined as predictors of responder status. Significant post-training improvement in cognitive composite score (Cohen's d = .41) was observed across the sample, with n = 21 and n = 16 classified as responders and non-responders, respectively. Near learning was evidenced by significant improvement on each training exercise with practice; however, learning did not directly predict responder status. Group-wise comparison of responders and non-responders identified two factors favoring responders: higher EEG individual alpha frequency (IAF) and lower antipsychotic dosing. Tested in moderation analyses, IAF interacted with learning to predict improvement in cognitive outcome. CR outcome in schizophrenia is not directly explained by learning during training and appears to depend on latent factors influencing far transfer of trained abilities. Further understanding of factors influencing transfer of learning is needed to optimize CR efficacy.

496P - Higher osimertinib introduction rate achieved by multiple repeated re-biopsy after acquired resistance to first/second generation EGFR-TKIs

BackgroundIndication for treatment with osimertinib after first/second generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) resistance depends on T790M mutation detected by re-biopsy. REMEDY trial consisting many cases using plasma biopsy revealed osimertinib introduction rate of approximately 25 percent in EGFR-mutant non-small cell lung cancer (NSCLC) patients pretreated with first/second generation EGFR-TKIs. The aim of study is to analyze the data on clinical practice of our hospital, where histological re-biopsy is actively carried out multiple times. MethodsWe retrospectively reviewed our electronic medical records of EGFR-mutant NSCLC patients to examine osimertinib introduction rate and associated outcomes. ResultsAmong 95 patients with EGFR-mutant NSCLC, 73 patients received first/second generation EGFR-TKIs. Of 57 progressive disease patients, 50 patients (57/50: 87%) underwent re-biopsy. T790M was detected in 36 patients (36/50: 72%) and osimertinib was introduced in 35 patients (35/50: 70%). Among 36 patients harboring T790M mutation: histological re-biopsy was performed in 21 patients (21/36: 58%); cytology in 12 patients (12/36: 33%); blood biopsy in three patients (3/36: 8.3%). T790M was detected by first re-biopsy in 14 patients (14/36: 39%), and by second or subsequent re-biopsy 22 patients (22/36: 61%). The median overall survival (OS) in osimertinib induction patients was not reached (95% CI, 64.2-not reached) while in non- osimertinib patients median OS was 92.9 months (95% CI, 22.5-not reached) (p = 0.0173). Five year survival rates were 77% and 52%, respectively. ConclusionsHigher osimertinib introduction rate was achieved by multiple repeated re-biopsy after first/second generation EGFR-TKIs, and its high introduction rate could contribute to better prognosis of EGFR-mutant NSCLC. Legal entity responsible for the studyKobe Minimally Invasive Cancer Center. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

RHEUMATIC HEART DISEASE PRESENTING AS PROGRESSIVE DYSPNEA AND PULMONARY INFILTRATES

SESSION TITLE: Cardiovascular Disease 1 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: Acute rheumatic fever and subsequently rheumatic heart disease (RHD) has been significantly reduced in developed countries during the 20th century. Although uncommon, RHD remains present in undeveloped countries and immigrant populations. Knowledge of common presentations of this once ubiquitous disease thus remains clinically useful. CASE PRESENTATION: A 32-year-old African-American male presented for 7 days of progressive dyspnea, diaphoresis with exertion, and pleuritic chest pain. Prior evaluation was concerning for community acquired pneumonia treated with azithromycin and doxycycline without improvement. On admission, the patient reported subjective fever without recent travel or known sick contacts. He is a naturalized citizen who lived in Sierra Leone until age 16 and currently works with a predominantly immigrant population as a pig butcher. The patient’s past medical history was grossly unremarkable. Physical exam was significant for right lung crackles on inspiration and grade 3 holosystolic murmur with normal respiratory rate and oxygen saturation on room air. Chest x-ray at the time of presentation was notable for progressive worsening of a right upper lobe (RUL) infiltrate. Patient was started on Levaquin and admitted to the hospital for pneumonia versus tuberculosis. CT of the chest was completed for concern of non-resolving pulmonary symptoms and noted for RUL infiltrate and left ventricular hypertrophy (LVH). ECG also suggested LVH and transthoracic echocardiogram showed a dilated cardiomyopathy with severely reduced ejection fraction (20-25%), severe mitral regurgitation and severe aortic regurgitation. This presentation was highly suggestive of RHD with pulmonary infiltrate secondary to retrograde flow secondary to significant valvular disease, confirmed with transesophageal echocardiogram. The patient was transferred to a tertiary surgical center on hospital day 6 for valve replacement. DISCUSSION: This case represents classic findings of RHD with secondary mitral valve regurgitation and RUL pulmonary infiltrates. Per the REMEDY trial, the patient’s presentation of chronic rheumatic valvular disease leading to acute heart failure is the most common presentation of RHD. This exemplifies the need to suspect this disease in patients with the appropriate clinical history and in patients from countries where rheumatic fever and RHD are still common. CONCLUSIONS: RHD continues to be clinically relevant despite significant decrease in incidence among the US population. Presentation with signs of pulmonary infiltrate due to retrograde flow via the pulmonary veins is more than a theoretic presentation and supports maintenance of a broad differential especially in patients tied to the developing world. Reference #1: Essop MR, Nkomo VT. Rheumatic and nonrheumatic valvular heart disease: epidemiology, management, and prevention in Africa. Circ. 2005;112(23),3584-3591. Reference #2: Watkins DA., Johnson CO, Colquhoun SM, et al. Global, regional, and national burden of rheumatic heart disease, 1990-2015. N Engl J Med. 2017;377:713-722. Reference #3: Zuhlke L, Engel ME, Karthikeyan G, et al. Characteristics, complications, and gaps in evidence-based interventions in rheumatic heart disease: the Global Rheumatic Heart Disease Registry (the REMEDY study). Eur Heart J. 2015; 36(18),1115-1122. DISCLOSURES: no disclosure on file for Travis Bentz; No relevant relationships by Nathan Boyer, source=Web Response No relevant relationships by Aaron Farmer, source=Web Response No relevant relationships by Samone Franzese, source=Web Response No relevant relationships by John Lammie, source=Web Response No relevant relationships by Michael Phillips, source=Web Response

Less abnormal uterine bleeding with dabigatran than warfarin in women treated for acute venous thromboembolism

Introduction Although direct oral anticoagulants (DOACs) are associated with a better safety profile than warfarin in patients with acute venous thromboembolism (VTE), direct factor Xa inhibitors involve a higher risk of abnormal uterine bleeding (AUB). We aimed to determine the risk of AUB during anticoagulation with dabigatran compared with warfarin. Methods Post-hoc analysis of the pooled RE-COVER studies and the RE-MEDY trial. Incidences of AUB, based on a defined preferred terms search for adverse events, in female patients aged 18-50 years treated with dabigatran, were compared with those in women treated with warfarin. Results Of the 2964 women included in the above-mentioned trials, 1280 women were in the relevant age category (18-50 years) and included in the current analysis. A total of 643 patients were randomized to treatment with dabigatran and 637 to treatment with warfarin. The overall rate of AUB was 8.1%, 5.9% for the women treated with dabigatran and 9.6% in those treated with warfarin, for an odds ratio for dabigatran-treated patients of 0.59 (95% confidence interval [CI], 0.39-0.90; P = 0.015). In the dabigatran-treated patients, three (0.5%) suffered major bleeding (MB) vs. five (0.8%) in the warfarin-treated patients (HR, 0.65; 95% CI, 0.15-2.72). MB or non-major relevant bleeding occurred in 30 (4.7%) patients randomized to receive dabigatran and 57 (8.9%) randomized to receive warfarin (HR, 0.53; 95% CI, 0.34-0.83). None of the bleeding events was fatal. Conclusion Dabigatran treatment was associated with a significantly (41%) lower risk of AUB than warfarin. Future studies in daily practice are needed to corroborate these findings.

Towards a biomarker model for cognitive improvement: No change in memory-related prefrontal engagement following a negative cognitive remediation trial in bipolar disorder

Cognitive deficits are prevalent in bipolar disorder during remission but effective cognition treatments are lacking due to insufficient insight into the neurobiological targets of cognitive improvement. Emerging data suggest that dorsal prefrontal cortex target engagement is a key neurocircuitry biomarker of pro-cognitive treatment effects. In this randomized controlled functional magnetic resonance imaging study, we test this hypothesis by investigating the effects of an ineffective cognitive remediation intervention on dorsal prefrontal response during strategic memory encoding and working memory engagement. Bipolar disorder patients in partial remission with subjective cognitive difficulties were randomized to receive 12-week group-based cognitive remediation ( n = 13) or to continue their standard treatment ( n = 14). The patients performed a strategic episodic picture encoding task and a spatial n-back working memory task under functional magnetic resonance imaging at baseline and following cognitive remediation or standard treatment. The right dorsolateral prefrontal cortex was commonly activated by both strategic memory tasks across all patients. The task-related prefrontal engagement was not altered by cognitive remediation relative to standard treatment. The dorsolateral prefrontal cortex response was not significantly associated with recall accuracy or working memory performance. As hypothesized, no task-related change in prefrontal activity was observed in a negative cognitive remediation trial in remitted bipolar disorder patients. By complementing previous findings linking cognitive improvement with increased dorsolateral prefrontal cortex engagement, our negative findings provide additional validity evidence to the dorsal prefrontal target engagement biomarker model of cognitive improvement by strengthening the proposed causality between modulation of dorsolateral prefrontal cortex engagement and pro-cognitive effects.

Using sequential analysis to assess component integrity of discrete-trial teaching programs

ABSTRACTTreatment integrity is the extent to which interventionists implement treatment procedures as prescribed. The majority of treatment integrity research involving discrete-trial teaching (DTT) reports an overall score summarizing integrity across procedural components. Because DTT is a procedure consisting of multiple steps, practitioners may find it helpful to report integrity data separately for each component (i.e., component integrity). Recent research has found that high levels of overall integrity are not always representative of high integrity for individual treatment components. The purpose of this study was to assess component integrity of DTT programs occurring in the natural environment with a specific emphasis on identifying integrity errors for an error-correction procedure consisting of remedial trials. The results showed that high overall levels of integrity did not correspond to high levels of integrity for the remedial trial portion of the error-correction procedures. We discuss the implications of the results for research and practice.

Small Scale In-Situ Bioremediation of Diesel Contaminated Soil – Screeing Life Cycle Assessment of Environmental Performance

Spillage of diesel oil and other petroleum products is a commonly creating need for site remediation of contaminated soils. In Sweden the most common remediation action is excavation of the contaminated soil and off site biological treatment by composting. However, a number of small sites spread out in rural areas end up low on priority lists, and will not be attended to within foreseeable future if ever. For such areas a low cost, easy to apply remediation techniques would be of interest. Enhanced bioremediation of diesel contaminants in soil by whey addition has been demonstrated in lab scale. Whey is a by-product from cheese production. A first pilot remediation trial on an actual site in Gäddede, County of Jämtland, was started the summer of 2010. Using this site as a case study a screening life cycle assessment model has been set up. The goal of the study was to investigate the environmental performance of the whey method, to benchmark the whey method toward the excavation and composting practice and to identify environmental hot spots in the whey treatment life cycle. The study aims at establishing if further work should be put into developing the method, or if the environmental performance is such that the whey method should be abandoned. It should be noted that even with a slightly worse environmental performance compared to other remediation alternatives whey treatment could still be of interest, since the small scale sites in rural areas we talk about here otherwise most often would not be attended to. Results from the screening life cycle assessment indicate a rather good environmental performance of the whey method, partly depending on impact category considered. For the whey method, impacts from farming activities in the milk production chain allocated to the whey give significant contributions. Transportation gives important impacts from both the whey method and the excavation and off site composting, thus logistics should always be considered and optimized. The whey onsite treatment could be an interesting alternative for bioremediation especially at sites that would not otherwise be treated, due to small size or remote location.

Dabigatran Is Associated with a Significantly Lower Risk of Abnormal Uterine Bleeding Than Warfarin in Female Patients of Childbearing Age with Venous Thromboembolism

▪Introduction: While Direct Oral Anticoagulants (DOACs) have been shown to have an overall equal efficacy as and better safety profile than warfarin in patients with acute venous thromboembolism (VTE), Xa-inhibitors have been associated with a higher risk of abnormal uterine bleeding (AUB). No data regarding AUB with the direct thrombin inhibitor dabigatran etexilate (dabigatran) have been reported to date.Aim: To determine the risk of AUB during anticoagulation with dabigatran compared to warfarin in female VTE patients aged 18-50 years.Methods: We performed a post hoc analysis of the pooled RE-COVER studies, two double-blind randomized trials evaluating dabigatran administered at a dose of 150mg twice daily versus warfarin after an initial treatment with parenteral anticoagulants, and the RE-MEDY trial, a double-blind randomized trial that studied the extended use of dabigatran at the same dose versus warfarin, all in patients with VTE. We compared the incidence of AUB, based on a defined preferred terms search in adverse events, in female patients aged 18-50 years who were treated with dabigatran versus who were treated with warfarin. Patients who rolled-over from RE-COVER into RE-MEDY and stayed on the same treatment were accounted for as "only one patient" taking the whole treatment period into consideration, whereas patients who switched treatment were analyzed as two different study subjects.Results: Of the 2964 women included in the above mentioned trials, 1280 women were in the relevant age category and included in the current analysis. A total of 643 patients were randomized to treatment with dabigatran and 637 to treatment with warfarin. The overall rate of AUB was 5.9% for the women treated with dabigatran and 9.6% in those treated with warfarin, for an Odds Ratio of 0.59 (95% confidence interval 0.39-0.90).Conclusion: In female VTE patients of 18-50 years old, dabigatran was associated with a significantly 41% lower risk of AUB than warfarin. DisclosuresFerreira:BMS-Pfizer: Consultancy, Other: Grant support; Bayer: Other: Grant support. Klok:Boehringer Ingelheim Pharma GmbH & Co.KG: Research Funding; Bristol-Myers Squibb: Research Funding; Bayer HealthCare: Research Funding; Daiichi-Sankyo: Research Funding. Feuring:Boehringer Ingelheim Pharma GmbH & Co.KG: Employment. Fraessdorf:Boehringer Ingelheim Pharma GmbH & Co.KG: Employment. Kreuzer:Boehringer Ingelheim: Employment. Huisman:GlaxoSmithKline: Other: Grant support; Boehringer Ingelheim Pharma GmbH & Co.KG: Other: Grant support; Bayer HealthCare: Other: Grant support; Pfizer: Other: Grant support; Actelion: Other: Grant support.

Rosuvastatin for Reduction of Myocardial Damage during Coronary Angioplasty - the Remedy Trial.

Periprocedural myocardial infarction (MI) is a frequent complication of percutaneous coronary intervention (PCI). Statins might reduce its incidence. The aims of the present studyare to assess whether such benefit is a class-effect or whether differences exist between various lipid-lowering strategies and whether cardioprotectionis exerted by increasing circulating endothelial progenitor cells (EPCs). The REMEDY study will enroll a total of 1080 patients submitted to elective PCI. Eligible patients will be randomized into 4 groups: 1) placebo; 2) atorvastatin (80mg+40mg before PCI); 3) rosuvastatin (40mg twice before PCI); and 4) rosuvastatin (5mg) and ezetimibe (10mg) twice before PCI. Peri-procedural MI is defined as an elevation of markers of cardiac injury (either CK-MB or troponin I or T) values >5x the upper reference limit estimated at the 99th percentile of the normal distribution, or a rise >20% in case of baseline values already elevated. EPCs will be assessed before, at 24h and - in a subset of diabetic patients - at 3months after PCI (EPC-substudies). The primary endpoint of the main REMEDY study is the rate of peri-procedural MI in each of the 4 treatment arms. Secondary endpoints are the combined occurrence of 1-month major adverse events (MACE, including death, MI, or the need for unplanned revascularization); and any post-procedural increase in serum creatinine. Endpoints of the EPC-substudies are the impact of tested regimens on 1) early (24-h) and 3-month EPC levels and functional activity; 2) stent strut re-endothelialization and neointimal hyperplasia; 3) 1-year MACE. REMEDY will add important information on the cardioprotective effects of statins after PCI.

Development and Characterization of PCE-to-Ethene Dechlorinating Microcosms with Contaminated River Sediment.

An industrial complex in Wonju, contaminated with trichloroethene (TCE), was one of the most problematic sites in Korea. Despite repeated remedial trials for decades, chlorinated ethenes remained as sources of down-gradient groundwater contamination. Recent efforts were being made to remove the contaminants of the area, but knowledge of the indigenous microbial communities and their dechlorination abilities were unknown. Thus, the objectives of the present study were (i) to evaluate the dechlorination abilities of indigenous microbes at the contaminated site, (ii) to characterize which microbes and reductive dehalogenase genes were responsible for the dechlorination reactions, and (iii) to develop a PCE-to-ethene dechlorinating microbial consortium. An enrichment culture that dechlorinates PCE to ethene was obtained from Wonju stream, nearby a trichloroethene (TCE)-contaminated industrial complex. The community profiling revealed that known organohalide-respiring microbes, such as Geobacter, Desulfuromonas, and Dehalococcoides grew during the incubation with chlorinated ethenes. Although Chloroflexi populations (i.e., Longilinea and Bellilinea) were the most enriched in the sediment microcosms, those were not found in the transfer cultures. Based upon the results from pyrosequencing of 16S rRNA gene amplicons and qPCR using TaqMan chemistry, close relatives of Dehalococcoides mccartyi strains FL2 and GT seemed to be dominant and responsible for the complete detoxification of chlorinated ethenes in the transfer cultures. This study also demonstrated that the contaminated site harbors indigenous microbes that can convert PCE to ethene, and the developed consortium can be an important resource for future bioremediation efforts.

Remediation trials for hydrocarbon-contaminated soils in arid environments: Evaluation of bioslurry and biopiling techniques

Effective bioremediation requires an extensive understanding of the soil parameters and microbial community diversity. Long term contamination of petroleum hydrocarbon soils in arid areas present unique opportunities to study the response of the impacted microbial community to bioremediation efforts. Two bioremediation treatments viz., biopile and bioslurry, were applied to assess the efficacy of different bioremediation methods in long term petroleum hydrocarbon contaminated soils. The bioslurry treatment was markedly more effective at treating the long term petroleum hydrocarbon contaminated soils in a short period of time. First order rates of hydrocarbon degradation in the bioslurry treatment were between 0.066 and 0.073 d−1 compared with the biopile treatment where the rates ranged from 0.011 to 0.03 d−1, depending on the level and nature of the hydrocarbon fractions present in the soils. Bioslurry treatment of the long term contaminated soils exhibited a shift in the microbial community composition. Alpha-proteobacteria dominated the microbial community present in the hydrocarbon contaminated soils but bioslurry treatment of the contaminated soils led to a clear shift in the microbial community present in the soils, with Gamma-proteobacteria dominating the remediation environment along with microbial sequences associated with the TM7 phylum and a subsequent reduction in hydrocarbon concentration in the soils.

Selecting enhancing solutions for electrokinetic remediation of dredged sediments polluted with fuel

In this paper a procedure for selecting the enhancing solutions in electrokinetic remediation experiments is proposed. For this purpose, dredged marine sediment was contaminated with fuel, and a total of 22 different experimental conditions were tested, analysing the influence of different enhancing solutions by using three commercial non-ionic surfactants, one bio-surfactant, one chelating agent, and one weak acid. Characterisation, microelectrophoretic and electrokinetic remediation trials were carried out. The results are explained on the basis of the interactions between the fuel, the enhancing electrolytes and the matrix. For one specific system, the electrophoretic zeta potential, (ζ), of the contaminated matrix in the solution was found to be related to the electroosmotic averaged ζ in the experiment and not to the efficiency in the extraction. This later was correlated to a parameter accounting for both contributions, the contaminant and the enhancing solution, calculated on the basis of differences in the electrophoretic ζ in different conditions which has allowed to propose a methodology for selection of enhancing solutions.

The role of low cognitive effort and negative symptoms in neuropsychological impairment in schizophrenia.

Two experiments were conducted to examine whether insufficient effort, negative symptoms (e.g., avolition, anhedonia), and psychological variables (e.g., anhedonia and perception of low cognitive resources) predict generalized neurocognitive impairment in individuals with schizophrenia (SZ). In Experiment 1, participants included 97 individuals with SZ and 63 healthy controls (CN) who completed the Victoria Symptom Validity Test (VSVT), the MATRICS Consensus Cognitive Battery (MCCB), and self-report anhedonia questionnaires. In Experiment 2, participants included 46 individuals with SZ and 33 CN who completed Green's Word Memory Test (WMT), the MCCB, and self-reports of anhedonia, defeatist performance beliefs, and negative expectancy appraisals. RESULTS indicated that a low proportion of individuals with SZ failed effort testing (1.0% Experiment 1; 15.2% Experiment 2); however, global neurocognitive impairment was significantly predicted by low effort and negative symptoms. Findings indicate that low effort does not threaten the validity of neuropsychological test results in the majority of individuals with schizophrenia; however, effort testing may be useful in SZ patients with severe negative symptoms who may be more likely to put forth insufficient effort due to motivational problems. Although the base rate of failure is relatively low, it may be beneficial to screen for insufficient effort in SZ and exclude individuals who fail effort testing from pharmacological or cognitive remediation trials.

Comparison of most‐to‐least to error correction for teaching receptive labelling for two children diagnosed with autism

Prompting systems are guidelines of when to provide learners with prompts and when to fade prompts. Today, there are several prompting systems implemented to teach receptive labeling to individuals diagnosed with autism spectrum disorders and other disabilities. This study compared most‐to‐least prompting to an error correction procedure involving feedback and remedial trials for teaching two children with autism a variety of receptive labels. All teaching was implemented in a one‐to‐one instructional setting. Researchers taught each participant how to receptively identify 18 pictures; nine were taught using error correction and nine were taught using most‐to‐least. The researchers utilized an adapted alternating treatment design nested into a multiple probe design to evaluate the two procedures. Results indicated that participants were able to reach mastery criterion on 100% of skills taught using the error correction and were able to reach mastery criterion on 88.9% of skills taught using most‐to‐least. Additionally, error correction tended to require fewer trials for participants to reach mastery criterion.

Spatial distribution of metal contamination before and after remediation in the Meza Valley, Slovenia

Geostatistical technique was used to predicted spatial reduction of metal contamination after applying EDTA-based soil remediation. Soil samples from 268 locations in the Meza Valley, Slovenia with Pb and Zn concentrations up to 8955 and 15518mgkg−1 were extracted with the chelating agent ethylenediamine tetraacetate (EDTA). On average, 63 and 22% of Pb and Zn, respectively, were removed with washing solution containing 60mmol EDTA per kg of soil and 75 and 34% of Pb and Zn with 120mmol EDTA kg−1 soil. Spatial structure analysis revealed a good spatial structure and little spatial variation of data, which were further interpolated using Empirical Bayesian kriging to produce a continuous surface of Pb and Zn concentrations before and after remediation. Geostatistical simulations showed that the contaminated area covers 19.4km2 and that soil remediation (60mmol EDTA kg−1) has the potential to reduce the area with Pb and Zn above the critical regulatory threshold limit by 91 and 42%, respectively. Validated by pilot-scale remediation trials, soil extractions exhibit little scale-dependency of extraction efficiency. EDTA extraction also significantly reduced the bio-accessibility of toxic metals that remained in the soil after remediation using the unified bio-accessibility method. Pb and Zn concentrations accessible from the simulated intestinal phase were reduced by up to 99 and 96%, respectively.