Can cyanobacterial diversity in the source predict the diversity in sludge and the risk of toxin release in a drinking water treatment plant?

ABSTRACT: Conventional processes (coagulation, flocculation, sedimentation, and filtration) are widely used in drinking water treatment plants and are considered a good treatment strategy to eliminate cyanobacterial cells and cell-bound cyanotoxins. The diversity of cyanobacteria was investigated using taxonomic cell counts and shotgun metagenomics over two seasons in a drinking water treat- ment plant before, during, and after the bloom. Changes in the community structure over time at the phylum, genus, and species levels were monitored in samples retrieved from raw water (RW), sludge in the holding tank (ST), and sludge supernatant (SST). Aphanothece clathrata brevis, Microcystis aeruginosa, Dolichospermum spiroides, and Chroococcus minimus were predominant species detected in RW by taxonomic cell counts. Shotgun metagenomics revealed that Proteobacteria was the pre- dominant phylum in RW before and after the cyanobacterial bloom. Taxonomic cell counts and shotgun metagenomic showed that the Dolichospermum bloom occurred inside the plant. Cyanobac- teria and Bacteroidetes were the major bacterial phyla during the bloom. Shotgun metagenomics also showed that Synechococcus, Microcystis, and Dolichospermum were the predominant detected cyanobacterial genera in the samples. Conventional treatment removed more than 92% of cyanobac- terial cells but led to cell accumulation in the sludge up to 31 times more than in the RW influx. Coagulation/sedimentation selectively removed more than 96% of Microcystis and Dolichospermum. Cyanobacterial community in the sludge varied from raw water to sludge during sludge storage (1–13 days). This variation was due to the selective removal of coagulation/sedimentation as well as the accumulation of captured cells over the period of storage time. However, the prediction of the cyanobacterial community composition in the SST remained a challenge. Among nutrient parameters, orthophosphate availability was related to community profile in RW samples, whereas communities in ST were influenced by total nitrogen, Kjeldahl nitrogen (N- Kjeldahl), total and particulate phos- phorous, and total organic carbon (TOC). No trend was observed on the impact of nutrients on SST communities. This study profiled new health-related, environmental, and technical challenges for the production of drinking water due to the complex fate of cyanobacteria in cyanobacteria-laden sludge and supernatant

The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

Optimal Treatment Strategies to Prevent and Manage Cyanobacteria and Cyanotoxins in Drinking Water Sludge

RÉSUMÉ: Ces dernières années, l'accumulation de cyanobactéries et leur cyanotoxines dans les boues générées par des procédés de traitement conventionnels (coagulation, floculation, décantation et filtration) ont suscité des inquiétudes liées à la santé dans les usines de filtration de l'eau potable. Le devenir des cyanobactéries et cyanotoxines dans les boues est complexe en raison de l'impact simultané de la composition des cyanobactéries de l'eau brute, des conditions environnementales et de divers phénomènes tels que la survie des cellules, la croissance, la lyse et le relâchement de cyanotoxines pendant le stockage des boues. Cependant, peu d'informations est disponible sur i) la dynamique des changements de la composition de la communauté cyanobactérienne entre l'eau brute et les boues stockées, ainsi que le surnageant associé, ii) le devenir des cyanobactéries et cyanotoxines lors du stockage de boues et iii) le traitement des boues contenant des cyanobactéries et cyanotoxines. L'objectif général de cette recherche est d'étudier le devenir des cyanobactéries et des cyanotoxines dans les usines de filtration de l'eau potable pendant le stockage et la manipulation. ABSTRACT: Health-related concerns on accumulation of cyanobacteria and cyanotoxins in the sludge of conventional treatment processes (coagulation, flocculation, sedimentation, and filtration) have been raised in drinking water treatment plants (DWTPs) in recent years. The fate of cyanobacteria and cyanotoxins in the sludge is complex due to the simultaneous impact of cyanobacterial composition in the intake water, environmental conditions, and various phenomena such as cell survival, growth, lysis, and cyanotoxin release during sludge storage. However, little information about the dynamics of cyanobacterial shifts from the intake water towards sludge and supernatant, the fate of cyanobacteria and cyanotoxins during sludge storage, and treatment of cyanobacteria-laden sludge is available. The general objective of this research study is to investigate the fate of cyanobacteria and cyanotoxins in the sludge of DWTPs during storage and handling. The specific objectives are to: i) Diagnose critical points of DWTPs where cyanobacteria cells and their associated cyanotoxins accumulate, ii) Determine the relationship between cyanobacterial communities in the intake water, sludge, and sludge supernatant; iii) Determine the impact of nutrients on cyanobacterial community shifts in the intake water, sludge, and sludge supernatant; iv) Compare taxonomic cell counts with shotgun metagenomic sequencing results; v) Validate cyanobacterial cell growth during sludge storage, vi) Study the dynamics of the cyanobacterial compositions in the stored sludge under controlled conditions, vii) Investigate the most resistant and susceptible cyanobacterial genus during sludge storage, viii) Study the potential health impact (i.e. cyanotoxin release) of the genera surviving sludge storage, ix) Investigate the impact of oxidation on cyanobacteria and cyanotoxins in both lab- and full- scales, x) Determine the efficiency of oxidation during sludge storage, xi) Evaluate the impact of oxidation and stagnation on microbial and cyanobacterial communities, xii) Conduct a critical review on the fate of cyanobacteria and cyanotoxins in conventional treatment plants' sludge and during sludge storage and, xiii) Develop an operational decision framework to determine the best practice to minimize risks associated with cyanobacteria and cyanotoxin presence in DWTPs

Inverse and direct optimization shape of airfoil using hybrid algorithm Big Bang-Big Crunch and Particle Swarm Optimization

In this paper, Big Bang-Big Crunch and Particle Swarm Optimization algorithms are combined and used for the first time to optimize airfoil geometry as a aerodynamic cross section. The optimization process is carried out both in reverse and direct directions. In the reverse approach, the object function is the difference between pressure coefficients of the optimized and target airfoils, which must be minimized. In the direct approach, three objective functions are introduced, the first of which is the drag to lift (D/L) ratio. It is minimized considering four different initial geometries, ultimately, all four geometries converge to the same final geometry. In other cases, maximizing lift the coefficient with the fixed drag coefficient constraint and minimizing the drag coefficient while the lift coefficient is fixed are defined as purposes. The results show that by changing the design parameters of the initial airfoil geometry, the proposed hybrid optimization algorithm as a powerful method satisfies the needs with proper accuracy and finally reaches the desired geometry

A comprehensive study on criteria of sustainable urban waste management system: using content analysis

Abstract The present study was developed to comprehensively analyze experts' views and content of documents focusing on goals and criteria of sustainable waste management system in Tehran, Iran. To this end, the suitable goals for sustainable waste management system in Tehran city were adopted from domestic, national and international documents. For this purpose, 27 national and international documents and 2 domestic documents related to waste management were selected and analyzed by using content analysis according to Gall, 1994. Further, in order to formulate goals in case of bottlenecks and challenges of waste management in Tehran, the focus group technique was used based on Stewart and Shamdasani, 2014. At this stage, 24 key experts in the field of waste management were interviewed in the form of 4 focus groups. Data collection were performed via audio recording and word-for-word implementation of conversations, taking notes and writing field notes. The data collection continued until reaching theoretical saturation. Next, content analysis and coding methods were used to analyze the data. Finally, the goals of waste management were divided into five general categories including: institutional (with emphasis on the integration and inclusion of the key elements of the urban waste management system), technical and infrastructural (with emphasis on the optimization of existing processes in the use of urban waste management technologies), environmental (with emphasis on minimizing the adverse health and environmental effects of the urban waste management system, economic (with emphasis on the economic and financial sustainability of the urban waste management system), and cultural-social (with emphasis on attracting the maximum participation of citizens and service recipients). The results clearly showed that sustainable waste management measures in Tehran should follow these five components in order to reduce the problems caused by unrealistic waste management and make sustainable use of basic, natural, financial and human resources

Reduction of UreB and CagA expression level by siRNA construct in Helicobacter pylori strain SS1

Abstract Background Two important virulence factors, urease and cagA, play an important role in Helicobacter pylori (H. pylori) gastric cancer. Aim of this study was to investigate the expression level and function of ureB and cagA using small interfering RNAs (siRNA). Methods SS1 strain of H. pylori was considered as host for natural transformation. siRNA designed for ureB and cagA genes were inserted in pGPU6/GFP/Neo siRNA plasmid vector to evaluate using phenotypic and genotypic approaches. Then, qPCR was performed for determining inhibition rate of ureB and cagA gene expression. Results The expression levels of siRNA-ureB and siRNA-cagA in the recombinant strain SS1 were reduced by about 5000 and 1000 fold, respectively, compared to the native H. pylori strain SS1. Also, preliminary evaluation of siRNA-ureB in vitro showed inhibition of urea enzyme activity. These data suggest that siRNA may be a powerful new tool for gene silencing in vitro, and for the development of RNAi-based anti-H. pylori therapies. Conclusion Our results show that targeting ureB and cagA genes with siRNA seems to be a new strategy to inhibit urease enzyme activity, reduce inflammation and colonization rate

A Higher Healthy Eating Index Is Associated with Decreased Markers of Inflammation and Lower Odds for Being Overweight/Obese Based on a Case-Control Study

Obesity is a health risk characterized by chronic inflammation, and food choices are strongly associated with its etiology. Our objective was to investigate the association between dietary patterns and the healthy eating index (HEI) with the odds of overweight/obesity and related inflammatory markers. Within a population-based case-control study, we collected data and samples from 793 normal-weight and 812 overweight/obese Iranian people (based on either body mass index (BMI) or body surface area (BSA)). Dietary intake and HEI scores were obtained via a validated 124-item food frequency questionnaire. Anthropometric and socioeconomic parameters, as well as blood inflammatory markers, were measured. Participants with higher HEI scores had higher serum high-density lipoprotein-cholesterol (HDL-C) and significantly lower energy intake. Water consumption in the overweight/obese group was significantly lower than in the control group. In the final models using partial correlation and controlling for multiple confounders, there was a significant inverse correlation between HEI and interleukin-4 (IL-4, R = −0.063), IL-1β (R = −0.054), and high-sensitivity C-reactive protein (hs-CRP, R = −0.069). Based on multivariable logistic regression models adjusted for multiple confounders, there was a significant association between HEI as a continuous variable (OR = 0.993, 95% CI: 0.988–0.999) and categorical variable (OR = 0.801, 95% CI: 0.658–0.977) and odds of overweight/obesity across BMI groups. The dietary patterns in the case and control groups however were similar, and we failed to find a significant association between HEI and odds of overweight/obesity based on BSA. Adherence to healthy eating recommendations may be a prudent recommendation to prevent overweight/obesity and keeping inflammatory indicators low

Evidence-Based Framework to Manage Cyanobacteria and Cyanotoxins in Water and Sludge from Drinking Water Treatment Plants

Freshwater bodies and, consequently, drinking water treatment plants (DWTPs) sources are increasingly facing toxic cyanobacterial blooms. Even though conventional treatment processes including coagulation, flocculation, sedimentation, and filtration can control cyanobacteria and cell-bound cyanotoxins, these processes may encounter challenges such as inefficient removal of dissolved metabolites and cyanobacterial cell breakthrough. Furthermore, conventional treatment processes may lead to the accumulation of cyanobacteria cells and cyanotoxins in sludge. Pre-oxidation can enhance coagulation efficiency as it provides the first barrier against cyanobacteria and cyanotoxins and it decreases cell accumulation in DWTP sludge. This critical review aims to: (i) evaluate the state of the science of cyanobacteria and cyanotoxin management throughout DWTPs, as well as their associated sludge, and (ii) develop a decision framework to manage cyanobacteria and cyanotoxins in DWTPs and sludge. The review identified that lab-cultured-based pre-oxidation studies may not represent the real bloom pre-oxidation efficacy. Moreover, the application of a common exposure unit CT (residual concentration × contact time) provides a proper understanding of cyanobacteria pre-oxidation efficiency. Recently, reported challenges on cyanobacterial survival and growth in sludge alongside the cell lysis and cyanotoxin release raised health and technical concerns with regards to sludge storage and sludge supernatant recycling to the head of DWTPs. According to the review, oxidation has not been identified as a feasible option to handle cyanobacterial-laden sludge due to low cell and cyanotoxin removal efficacy. Based on the reviewed literature, a decision framework is proposed to manage cyanobacteria and cyanotoxins and their associated sludge in DWTPs

Efficacy and safety of decompressive craniectomy in acute ischemic stroke patients treated with intravenous thrombolysis

Abstract Introduction The optimal timing for decompressive hemicraniectomy (DHC) after intravenous thrombolysis (IVT) remains unclear. This study in patients with acute ischemic stroke treated with IVT aimed to assess the safety of DHC and patient outcome. Methods Data was extracted from the Tabriz stroke registry from June 2011 up to September 2020. In all, 881 patients were treated with IVT. Among these, 23 patients underwent DH. Six patients were excluded due to symptomatic intracranial hemorrhage (parenchymal hematoma type 2 based on SITS-MOST definition) after IVT, but other types of bleeding after venous thrombolysis, including HI1, HI2, and PH1 were not excluded; so the remaining 17 patients were enrolled in the study. Functional Outcome was defined as the proportion of patients who achieved mRS score of 2–3 (moderate disability), 4–5 (severe disability), or 6 (mortality) at 90 days after stroke. mRSwas assess by trained neurologist at the hospital clinic with direct interview Safety outcome was assessed by comparison of two scans just prior to and after craniectomy. Any new hemorrhage or worsening of previous hemorrhage was reported. Parenchymal hematoma type 2, based on ECASS II definition, was considered as major surgical complication. This study was approved by the local ethics committee of the Tabriz University of Medical Sciences (Ethics Code: IR.TBZMED.REC.1398.420). Results At the three-month mRS follow up, six patients (35%) had moderate and five (29%) had severe disability. The outcome of death was observed in six patients (35%).Nine of 15 patients (60%) underwent surgery in the first 48 hours after onset of symptoms. No patient over 60 years of age survived to the three-month follow up; 67% of those who were under60 years and underwent DH in the first 48 hours had favorable outcome. Hemorrhagic complication was seen in 64% of patients but none was major. Conclusion Results of this study showed that the rate of major bleeding and outcome of acute ischemic stroke patients who underwent DHC after IVT is comparable with the reported data in the literature and intentionally waiting for the fibrinolytic effects of IVT to disappear may not outweigh the benefits of DHC. Although the findings of the study should be interpreted with caution and larger studies are needed to confirm the results

Impact of Stagnation on the Diversity of Cyanobacteria in Drinking Water Treatment Plant Sludge

Health-related concerns about cyanobacteria-laden sludge of drinking water treatment plants (DWTPs) have been raised in the past few years. Microscopic taxonomy, shotgun metagenomic sequencing, and microcystin (MC) measurement were applied to study the fate of cyanobacteria and cyanotoxins after controlled sludge storage (stagnation) in the dark in a full-scale drinking water treatment plant within 7 to 38 days. For four out of eight dates, cyanobacterial cell growth was observed by total taxonomic cell counts during sludge stagnation. The highest observed cell growth was 96% after 16 days of stagnation. Cell growth was dominated by potential MC producers such as Microcystis, Aphanocapsa, Chroococcus, and Dolichospermum. Shotgun metagenomic sequencing unveiled that stagnation stress shifts the cyanobacterial communities from the stress-sensitive Nostocales (e.g., Dolichospermum) order towards less compromised orders and potential MC producers such as Chroococcales (e.g., Microcystis) and Synechococcales (e.g., Synechococcus). The relative increase of cyanotoxin producers presents a health challenge when the supernatant of the stored sludge is recycled to the head of the DWTP or discharged into the source. These findings emphasize the importance of a strategy to manage cyanobacteria-laden sludge and suggest practical approaches should be adopted to control health/environmental impacts of cyanobacteria and cyanotoxins in sludge