Safety and efficacy of COVID-19 vaccines: A systematic review and meta-analysis of controlled and randomized clinical trials.

Vaccines against coronavirus disease 2019 (COVID-19) have been discovered within a very small duration of time as compared to the traditional way for the development of vaccines, which raised the question about the safety and efficacy of the approved vaccines. The purpose of this study is to look at the effectiveness and safety of vaccine platforms against the incidence of COVID-19. The literature search was performed on PubMed/Medline, Cochrane, and clinical trials.gov databases for studies published between 1 January 2020 and 19 February 2022. Preferred Reporting Items for Systemic Review and Meta-Analysis Statement guidelines were followed. Among 284 articles received by keywords, a total of 11 studies were eligible according to the inclusion and exclusion criteria (studies in special populations, e.g., pregnant women, paediatric patients, editorials, case reports, review articles, preclinical and in vitro studies) of the study. A total of 247,186 participants were considered for randomisation at baseline, among them, 129,572 (52.42%) were provided with vaccine (Intervention group) and 117,614 (47.58%) with the placebo (Control group). A pooled fold change estimation of 0.19 (95% CI: 0.12-0.31, p < 0.0001) showed significant protection against the incidence of COVID-19 in the vaccines received group versus the placebo group. mRNA based, inactivated vaccines and non-replicating viral vector-based vaccines showed significantly protection against the incidence of COVID-19 compared to placebo with pooled fold change estimation was 0.08 (95% CI: 0.06-0.10), 0.20 (95% CI: 0.14-0.29) and 0.36 (95% CI: 0.28-0.46), respectively. Injection site discomfort and fatigue were the most common side effect observed in mRNA, non-replicating viral vector, inactivated, and protein subunit-based vaccines. All the approved vaccines were found safe and efficacious but mRNA-based vaccines were found to be more efficacious against SARS-CoV-2 than other platforms.

Exploring the influence of invasive weed biochar on the sorption and dissipation dynamics of imazethapyr in sandy loam soil.

The management of invasive weeds on both arable and non-arable land is a vast challenge. Converting these invasive weeds into biochar and using them to control the fate of herbicides in soil could be an effective strategy within the concept of turning waste into a wealth product. In this study, the fate of imazethapyr (IMZ), a commonly used herbicide in various crops, was investigated by introducing such weeds as biochar, i.e., Parthenium hysterophorus (PB) and Lantana camara (LB) in sandy loam soil. In terms of kinetics, the pseudo-second order (PSO) model provided the best fit for both biochar-mixed soils. More IMZ was sorbed onto LB-mixed soil compared to PB-mixed soil. When compared to the control (no biochar), both PB and LB biochars (at concentrations of 0.2% and 0.5%) increased IMZ adsorption, although the extent of this effect varied depending on the dosage and type of biochar. The Freundlich adsorption isotherm provided a satisfactory explanation for IMZ adsorption in soil/soil mixed with biochar, with the adsorption process exhibiting high nonlinearity. The values of Gibb's free energy change (ΔG) were negative for both adsorption and desorption in soil/soil mixed with biochar, indicating that sorption was exothermic and spontaneous. Both types of biochar significantly affect IMZ dissipation, with higher degradation observed in LB-amended soil compared to PB-amended soil. Hence, the findings suggest that the preparation of biochar from invasive weeds and its utilization for managing the fate of herbicides can effectively reduce the residual toxicity of IMZ in treated agroecosystems in tropical and subtropical regions.

Transformer-based tool recommendation system in Galaxy.

BACKGROUND: Galaxy is a web-based open-source platform for scientific analyses. Researchers use thousands of high-quality tools and workflows for their respective analyses in Galaxy. Tool recommender system predicts a collection of tools that can be used to extend an analysis. In this work, a tool recommender system is developed by training a transformer on workflows available on Galaxy Europe and its performance is compared to other neural networks such as recurrent, convolutional and dense neural networks. RESULTS: The transformer neural network achieves two times faster convergence, has significantly lower model usage (model reconstruction and prediction) time and shows a better generalisation that goes beyond training workflows than the older tool recommender system created using RNN in Galaxy. In addition, the transformer also outperforms CNN and DNN on several key indicators. It achieves a faster convergence time, lower model usage time, and higher quality tool recommendations than CNN. Compared to DNN, it converges faster to a higher precision@k metric (approximately 0.98 by transformer compared to approximately 0.9 by DNN) and shows higher quality tool recommendations. CONCLUSION: Our work shows a novel usage of transformers to recommend tools for extending scientific workflows. A more robust tool recommendation model, created using a transformer, having significantly lower usage time than RNN and CNN, higher precision@k than DNN, and higher quality tool recommendations than all three neural networks, will benefit researchers in creating scientifically significant workflows and exploratory data analysis in Galaxy. Additionally, the ability to train faster than all three neural networks imparts more scalability for training on larger datasets consisting of millions of tool sequences. Open-source scripts to create the recommendation model are available under MIT licence at https://github.com/anuprulez/galaxy_tool_recommendation_transformers.

Cost-Efficacy Analysis of Use of Frozen Section Histology for Margin Assessment During Breast Conservation Surgery in Breast Cancer Patients.

BACKGROUND: Margin assessment is an essential component of breast conservation surgery (BCS). Re-excision of infiltrated margin(s) detected on paraffin section histology (PSH) needs reoperation, adding time, inconvenience and cost. Intra-operative assessment of margins using frozen section histology (IFSH) can potentially obviate need for re-operation, thus facilitating one-step oncologically complete BCS. METHODS: IFSH and PSH reports of consecutive patients undergoing BCS (2010-2020) were reviewed. Accuracy and cost-efficacy of IFSH were assessed, considering PSH as gold standard. Cost of achieving oncologically complete BCS in whole cohort with IFSH (Scenario-A) was calculated and compared using appropriate statistical tests, with hospital costs for the cohort in a hypothetical Scenario-B, where IFSH was presumed not to have been used and all patients with infiltrated margin(s) on PSH would have been re-operated. RESULTS: Of the 367 patients screened, 39 were excluded due to incomplete IFSH data. Of 328 patients analyzed, 59 (18%) had one or more margins were reported infiltrated on IFSH, managed by re-excision or mastectomy in the same sitting, thus avoiding a reoperation. Additional 8 (2.4%) had involved margins on PSH (False negative IFSH). Significantly higher number of reoperations (p < 0.001) would have been needed in scenario-B. Average cost of the first operation with use of IFSH was Indian Rupees (INR) 25791 which included INR660 as IFSH cost. The average cost of reoperation was INR23724 which could be avoided in 59 (18%) by use of IFSH. The average cost per patient to achieve oncologically complete surgery in scenario A utilizing IFSH was significantly lower (p = 0.001) by INR3101 (11.7%), c.w. that in scenario B. Significant cost-saving with IFSH was maintained in cost-efficacy analysis undertaken with various higher and lower costs assumptions. CONCLUSIONS: Use of IFSH facilitates one-step oncologically complete BCS in majority of patients and results in considerable cost saving, resulting in avoidance of reoperations, besides preventing patient anxiety and delay in adjuvant treatment. TRIAL REGISTRATION: Clinical Trials Registry-India (CTRI/2021/08/035896).

Use of appropriate statistical tools in biomedical research: Current trend & status.

Background & objectives: Due to lack of appropriate statistical knowledge, published research articles contain various errors related to the design, analysis and interpretation of results in the area of biomedical research. If research contains statistical error, however, costly, it may be of no use and the purpose of the investigation gets defeated. Many biomedical research articles published in different peer reviewed journals may retain several statistical errors and flaws in them. This study aimed to examine the trend and status of application of statistics in biomedical research articles. Study design, sample size estimation and statistical measures are crucial components of a study. These points were evaluated in published original research articles to understand the use or misuse of statistical tools. Methods: Three hundred original research articles from the latest issues of selected 37 journals were reviewed. These journals were from the five internationally recognized publication groups (CLINICAL KEY, BMJ Group, WILEY, CAMBRIDGE and OXFORD) accessible through the online library of SGPGI, Lucknow, India. Results: Among articles assessed under present investigation, 85.3 per cent (n=256) were observational, and 14.7 per cent (n=44) were interventional studies. In 93 per cent (n=279) of research articles, sample size estimation was not reproducible. The simple random sampling was encountered rarely in biomedical studies even though none of the articles was adjusted by design effect and, only five articles had used randomized test. The testing of assumption of normality was mentioned in only four studies before applying parametric tests. Interpretation & conclusions: In order to present biomedical research results with reliable and precise estimates based on data, the role of engaging statistical experts need to be appreciated. Journals must have standard rules for reporting study design, sample size and data analysis tools. Careful attention is needed while applying any statistical procedure as, it will not only help readers to trust in the published articles, but also rely on the inferences the published articles draw.

Effect of glucocorticoids on the development of COVID-19-associated pulmonary aspergillosis: A meta-analysis of 21 studies and 5174 patients.

COVID-19-associated pulmonary aspergillosis (CAPA) remains a high mortality mycotic infection throughout the pandemic, and glucocorticoids (GC) may be its root cause. Our aim was to evaluate the effect of systemic GC treatment on the development of CAPA. We systematically searched the PubMed, Google Scholar, Scopus and Embase databases to collect eligible studies published until 31 December 2022. The pooled outcome of CAPA development was calculated as the log odds ratio (LOR) with 95% confidence intervals (CI) using a random effect model. A total of 21 studies with 5174 patients were included. Of these, 20 studies with 4675 patients consisting of 2565 treated with GC but without other immunomodulators (GC group) and 2110 treated without GC or other immunomodulators (controls) were analysed. The pooled LOR of CAPA development was higher for the GC group than for the controls (0.54; 95% CI: 0.22, 0.86; p < .01). In the subgroups, the pooled LOR was higher for high-dose GC (0.90; 95% CI: 0.17, 1.62: p = .01) and dexamethasone (0.71; 95% CI: 0.35, 1.07; p < .01) but had no significant difference for low-dose GC (0.41; 95% CI: -0.07, 0.89; p = .09), and non-dexamethasone GC (0.21; 95% CI: -0.36, 0.79; p = .47), treated patients versus controls. GC treatment increases the risk of CAPA development, and this risk is particularly associated with the use of high-dose GC or dexamethasone treatment.

Effect of soil amendments on the sorption behavior of atrazine in sandy loam soil.

The sorption behavior of pesticides applied during cultivation of crops is affected by amendments such as farm yard manure (FYM) and vermicompost (VC) during land preparation. Among pesticides, atrazine, a widely used herbicide in many crops, was analyzed for its kinetics and sorption behavior through the addition of FYM and VC in sandy loam soil. The pseudo-second-order (PSO) model best fit the kinetics results in the recommended dose of FYM and VC mixed soil. More atrazine was sorbed onto VC mixed soil than FYM mixed soil. In comparison to control (no amendment), both FYM and VC (1, 1.5, and 2%) increased atrazine adsorption, but the effect varied with dosage and type of amendment. The Freundlich adsorption isotherm adequately explained atrazine adsorption in soil/soil + (FYM/VC) mixtures, and the adsorption was highly nonlinear. The values of Gibb's free energy change (ΔG) were negative for both adsorption and desorption in soil/soil + (FYM/VC) mixtures, suggesting sorption was exothermic and spontaneous in nature. The results revealed that the application of amendments used by farmers interferes the availability, mobility, and infiltration of atrazine in the soil. Therefore, the findings of this study suggest that amendments such as FYM and VC can be effectively used to minimize the residual toxicity of atrazine-treated ago-ecosystems in tropical and sub-tropical regions.

Relative Adrenal Insufficiency in Decompensated Cirrhotic Children: Does It Affect Outcome?

INTRODUCTION: Relative adrenal insufficiency (RAI) is associated with poor outcome in adult cirrhotics. So far, pediatric studies are not available on the same. We aimed to prospectively study the presence and outcome of RAI in children with decompensated cirrhosis over 180 days. METHODS: Hemodynamically stable children with decompensated cirrhosis were sampled for serum basal cortisol and peak cortisol (after 30 minutes of 1-µg intravenous Synacthen) at day 1 and day 21. RAI was diagnosed as peak cortisol <500 nmol/L. Serum cytokines (interleukin-6 and tumor necrosis factor-α) and lipid profile were correlated with RAI. Cohort was followed up for outcomes over 180 days for complications and survival. With the identified risk factors, prognostic models were derived and compared with pediatric end-stage liver disease (PELD) and Child-Turcotte-Pugh scores. RESULTS: Prevalence of RAI was 54% at baseline and 61% at day 21 in the enrolled patients (n = 63, aged 128 ± 48 months, male 78%). No significant differences in cytokines and serum lipid levels were seen between RAI and normal adrenal function groups. Patients with RAI at baseline (D1-RAI) developed higher complications at follow-up as compared to the normal adrenal function group (53% vs 24%, P = 0.02). The PELD score (odds ratio 1.08, confidence interval 1.05-1.12, P < 0.01) and D1-RAI (odds ratio 3.19, confidence interval 1.32-7.73, P = 0.01) were independent predictors of follow-up complications. The PELD-delta cortisol model (area under the receiver operating curve 0.84, P < 0.001, 92% sensitivity; 60% specificity) predicted morbidity better than isolated PELD or Child-Turcotte-Pugh scores. DISCUSSION: RAI is a risk factor for development of complications in pediatric cirrhosis over short-term follow-up. The PELD-delta cortisol score is a promising prognostic model for predicting follow-up complications.

Galaxy-ML: An accessible, reproducible, and scalable machine learning toolkit for biomedicine.

Supervised machine learning is an essential but difficult to use approach in biomedical data analysis. The Galaxy-ML toolkit (https://galaxyproject.org/community/machine-learning/) makes supervised machine learning more accessible to biomedical scientists by enabling them to perform end-to-end reproducible machine learning analyses at large scale using only a web browser. Galaxy-ML extends Galaxy (https://galaxyproject.org), a biomedical computational workbench used by tens of thousands of scientists across the world, with a suite of tools for all aspects of supervised machine learning.

A Deep Convolutional Neural Network-XGB for Direction and Severity Aware Fall Detection and Activity Recognition.

Activity and Fall detection have been a topic of keen interest in the field of ambient assisted living system research. Such systems make use of different sensing mechanisms to monitor human motion and aim to ascertain the activity being performed for health monitoring and other purposes. Towards this end, in addition to activity recognition, fall detection is an especially important task as falls can lead to injuries and sometimes even death. This work presents a fall detection and activity recognition system that not only considers various activities of daily living but also considers detection of falls while taking into consideration the direction and severity. Inertial Measurement Unit (accelerometer and gyroscope) data from the SisFall dataset is first windowed into non-overlapping segments of duration 3 s. After suitable data augmentation, it is then passed on to a Convolutional Neural Network (CNN) for feature extraction with an eXtreme Gradient Boosting (XGB) last stage for classification into the various output classes. The experiments show that the gradient boosted CNN performs better than other comparable techniques, achieving an unweighted average recall of 88%.

Making Cities Smarter-Optimization Problems for the IoT Enabled Smart City Development: A Mapping of Applications, Objectives, Constraints.

One of the prime aims of smart cities has been to optimally manage the available resources and systems that are used in the city. With an increase in urban population that is set to grow even faster in the future, smart city development has been the main goal for governments worldwide. In this regard, while the useage of Artificial Intelligence (AI) techniques covering the areas of Machine and Deep Learning have garnered much attention for Smart Cities, less attention has focused towards the use of combinatorial optimization schemes. To help with this, the current review presents a coverage of optimization methods and applications from a smart city perspective enabled by the Internet of Things (IoT). A mapping is provided for the most encountered applications of computational optimization within IoT smart cities for five popular optimization methods, ant colony optimization, genetic algorithm, particle swarm optimization, artificial bee colony optimization and differential evolution. For each application identified, the algorithms used, objectives considered, the nature of the formulation and constraints taken in to account have been specified and discussed. Lastly, the data setup used by each covered work is also mentioned and directions for future work have been identified. This review will help researchers by providing them a consolidated starting point for research in the domain of smart city application optimization.

The Impact of COVID-19 on the Clinical Practices, Working Environment, and Social Life of Intensivists in Non-COVID ICU.

Purpose: Enlightening the changes in the usual clinical practices, working environment, and social life of Intensivists working in noncoronavirus disease intensive care units (non-COVID ICU) during the COVID pandemic. Materials and methods: Observational cross-sectional study for Indian intensivists working in non-COVID ICUs conducted between July and September 2021. A 16-question online survey consisting of the work and social profile of the participating intensivists, changes in the usual clinical practices, working environment, and impact on their social life was administered. For the last three sections, intensivists were asked to compare pandemic times to prepandemic times (pre-mid-March 2020). Results: The number of invasive interventions performed by intensivists working in the private sector with lesser clinical experience (<12 years) were significantly less as compared to the government sector (p = 0.07) and clinically experienced (p = 0.07). Intensivists without comorbidities performed significantly lesser number of patient examinations (p = 0.03). The cooperation from healthcare workers (HCWs) decreased significantly with lesser experienced intensivists (p = 0.05). Leaves were significantly reduced in case of private sector intensivists (p = 0.06). Lesser experienced intensivists (p = 0.06) and intensivists working in the private sector (p = 0.06) spent significantly lesser time with family. Conclusion: Coronavirus disease-2019 (COVID-19) affected the non-COVID ICUs as well. Young and private sector intensivists were affected due to less leaves and family time. HCWs need proper training for better cooperation during the pandemic time. How to cite this article: Ghatak T, Singh RK, Kumar A, Patnaik R, Sanjeev OP, Verma A, et al. The Impact of COVID-19 on the Clinical Practices, Working Environment, and Social Life of Intensivists in Non-COVID ICU. Indian J Crit Care Med 2022;26(7):816-824.

Management of patients who opt for radical prostatectomy during the coronavirus disease 2019 (COVID-19) pandemic: an international accelerated consensus statement.

OBJECTIVE: Coronavirus disease-19 (COVID-19) pandemic caused delays in definitive treatment of patients with prostate cancer. Beyond the immediate delay a backlog for future patients is expected. The objective of this work is to develop guidance on criteria for prioritisation of surgery and reconfiguring management pathways for patients with non-metastatic prostate cancer who opt for surgical treatment. A second aim was to identify the infection prevention and control (IPC) measures to achieve a low likelihood of coronavirus disease 2019 (COVID-19) hazard if radical prostatectomy (RP) was to be carried out during the outbreak and whilst the disease is endemic. METHODS: We conducted an accelerated consensus process and systematic review of the evidence on COVID-19 and reviewed international guidance on prostate cancer. These were presented to an international prostate cancer expert panel (n = 34) through an online meeting. The consensus process underwent three rounds of survey in total. Additions to the second- and third-round surveys were formulated based on the answers and comments from the previous rounds. The Consensus opinion was defined as ≥80% agreement and this was used to reconfigure the prostate cancer pathways. RESULTS: Evidence on the delayed management of patients with prostate cancer is scarce. There was 100% agreement that prostate cancer pathways should be reconfigured and measures developed to prevent nosocomial COVID-19 for patients treated surgically. Consensus was reached on prioritisation criteria of patients for surgery and management pathways for those who have delayed treatment. IPC measures to achieve a low likelihood of nosocomial COVID-19 were coined as 'COVID-19 cold' sites. CONCLUSION: Reconfiguring management pathways for patients with prostate cancer is recommended if significant delay (>3-6 months) in surgical management is unavoidable. The mapped pathways provide guidance for such patients. The IPC processes proposed provide a framework for providing RP within an environment with low COVID-19 risk during the outbreak or when the disease remains endemic. The broader concepts could be adapted to other indications beyond prostate cancer surgery.

A Hierarchical Approach to Activity Recognition and Fall Detection Using Wavelets and Adaptive Pooling.

Human activity recognition has been a key study topic in the development of cyber physical systems and assisted living applications. In particular, inertial sensor based systems have become increasingly popular because they do not restrict users' movement and are also relatively simple to implement compared to other approaches. In this paper, we present a hierarchical classification framework based on wavelets and adaptive pooling for activity recognition and fall detection predicting fall direction and severity. To accomplish this, windowed segments were extracted from each recording of inertial measurements from the SisFall dataset. A combination of wavelet based feature extraction and adaptive pooling was used before a classification framework was applied to determine the output class. Furthermore, tests were performed to determine the best observation window size and the sensor modality to use. Based on the experiments the best window size was found to be 3 s and the best sensor modality was found to be a combination of accelerometer and gyroscope measurements. These were used to perform activity recognition and fall detection with a resulting weighted F1 score of 94.67%. This framework is novel in terms of the approach to the human activity recognition and fall detection problem as it provides a scheme that is computationally less intensive while providing promising results and therefore can contribute to edge deployment of such systems.

Sorption mechanisms of pesticides removal from effluent matrix using biochar: Conclusions from molecular modelling studies validated by single-, binary and ternary solute experiments.

Sorption of atrazine (ATZ), imidacloprid (IMIDA) and azoxystrobin (AZOXY) in single-, bi- and ternary-solutes system was modelled using phosphoric acid-treated rice straw biochar (T-RSBC). The T-RSBC showed stronger sorption capacity for IMIDA in single- and bi-solute systems. The Freundlich constant (KFads) in ternary system followed the order: ATZ (222.7) < IMIDA (1314) < AZOXY (1459). Adsorption modeling and molecular dynamics suggested that non-bonding interactions between aromatic groups and electrostatic interactions with the phosphate ester group in T-RSBC played an important role. Enhanced sorption by pore-filling may be attributed to the stacking of pesticide molecules in the form of multilayer. IMIDA was predominantly sorbed by pore-filling mechanism, whereas, ATZ adsorbed by partitioning mechanism. The percent removal of three pesticides in waste water effluent followed the order: AZOXY > IMIDA > ATZ. The Freundlich isotherm based multicomponent Sheindorf-Rebuhn-Sheintuch equation's suggested that the extent of ATZ adsorption, in the presence of co-habiting pesticides, decreased with increase in number of solutes (KiATZ, Singlev> KiATZ, Binary> KiATZ, Ternary). The competitive coefficient values (αATZ/IMIDA, Ternary > αATZ/AZOXY,Ternary) revealed that ATZ adsorption in ternary system was inhibited more by the presence of IMIDA than AZOXY. Findings suggested that biochar with a large fraction of non-carbonized phase promoted non-competitive sorption.

Chirality-induced spin polarization places symmetry constraints on biomolecular interactions.

Noncovalent interactions between molecules are key for many biological processes. Necessarily, when molecules interact, the electronic charge in each of them is redistributed. Here, we show experimentally that, in chiral molecules, charge redistribution is accompanied by spin polarization. We describe how this spin polarization adds an enantioselective term to the forces, so that homochiral interaction energies differ from heterochiral ones. The spin polarization was measured by using a modified Hall effect device. An electric field that is applied along the molecules causes charge redistribution, and for chiral molecules, a Hall voltage is measured that indicates the spin polarization. Based on this observation, we conjecture that the spin polarization enforces symmetry constraints on the biorecognition process between two chiral molecules, and we describe how these constraints can lead to selectivity in the interaction between enantiomers based on their handedness. Model quantum chemistry calculations that rigorously enforce these constraints show that the interaction energy for methyl groups on homochiral molecules differs significantly from that found for heterochiral molecules at van der Waals contact and shorter (i.e., ∼0.5 kcal/mol at 0.26 nm).

Effect of crop residue ashes on sorption behavior of herbicides used in the succeeding crop in Indian soils.

Effect of the wheat straw ash (WSA) on pretilachlor and the rice straw ash (RSA) on sulfosulfuron kinetics and adsorption behavior was studied. Kinetics study suggested that adsorption of herbicides in soil/soil + 0.2% ash mixture was best explained by the pseudo second order model. Ashes at 0.1%-0.5% levels increased adsorption of respective herbicide; but, effect varied with ash content and soil type. Effect of ash (0.2%) on herbicide's adsorption was more in the sandy loam soil (144%-188%) than in the clay loam soil (112%-122%) suggesting masking of ash particles. The Freundlich adsorption isotherm explained the adsorption of herbicides in the soils/soil + ash mixtures and sorption was highly nonlinear as 1/n (slope) values varied between 0.57 and 1.25 for pretilachlor and 0.32 and 0.77 for sulfosulfuron. Adsorption increased with increase in temperature. High surface area unburnt carbon in ashes was responsible for increase in adsorption and decrease in desorption of herbicides in ash mixed soils. The pH of soil/soil + ash mixtures affected herbicide adsorption, but effect was significant for pretilachlor. The negative free energy change (ΔG) values suggested that the sorption process was exothermic and spontaneous in nature. This study has implications in identifying the role of crop residue burning on fate of herbicides applied in succeeding crop.

Rice and wheat straw ashes: Characterization and modeling of pretilachlor sorption kinetics and adsorption isotherm.

The rice straw ash (RSA) and wheat straw ash (WSA) were explored as low cost adsorbent for pretilachlor removal from water. The ashes were characterized and sorption behavior of pretilachlor was evaluated. Kinetics study suggested that the modified Elovich model best explained the pretilachlor sorption on both the ashes. The adsorption data were analyzed using 2-, 3- and 4-parameter models and nine error functions were used to compute the best fit isotherm by nonlinear regression analysis. The pretilachlor was more sorbed onto the RSA (22.0-92.2%) than the WSA (11.4-61.4%) and percent adsorption decreased with increase in the herbicide concentration in solution. Isotherm model optimization analysis suggested that the Freundlich and the Temkin isotherms were the best models to predict the pretilachlor adsorption onto the RSA and the WSA. The error analysis suggested that the reciprocal of the observed squared (ROS) and the reciprocal of the predicted squared (RPS) error functions provided the best determination of the adsorption constants for the Freundlich and the Temkin isotherms, respectively. The RSA, which exhibited higher pretilachlor sorption potential, can be utilized as low cost adsorbent for pesticide removal from contaminated water.

Chemical Degradation of Sulfosulfuron in Aqueous Suspension of Rice and Wheat Straw Ashes.

Burning of wheat and rice straw on field, after crop harvest, is a quick, cheap and an easy way for land clearing. The ashes generated after burning are mixed with soils and due to their alkaline nature, they may affect the degradation of applied herbicides. Therefore, present paper reports degradation of sulfosulfuron in aqueous suspension of the wheat (WSA) and rice (RSA) straw ashes. The results suggested that both ashes significantly enhanced sulfosulfuron dissipation in water and effect was more with the RSA. The solution pH affected sulfosulfuron dissipation and in control buffers (no ash) herbicide degradation followed the order: acidic > alkaline > neutral. Addition of the RSA significantly increased sulfosulfuron degradation in buffers, but effect was more evident at neutral and alkaline pH. The study has relevance in assessing degradation of sulfosulfuron in soils where crop residues are burned for land clearing.