A Review on Antiviral Plants Effective against Different Virus Types

The treatment of microbial infections has proven challenging for humans in recent years. Synthetic medications, such as antimicrobial agents, are used for treating these infections. Antimicrobials derived from natural sources have gained popularity as an alternative to manufactured medications due to their lack of adverse effects. Plants, which play a significant role in this setting, have historically served as a reliable natural defence against several pathogens. In this study, studies on plants used against viral diseases are mentioned. Studies on viruses that cause disease have been compiled in the literature. According to the findings, it has been reported in the literature that many different plant species are effective against herpes simplex virus (HSV-1, HSV-2), human immunodeficiency virus (HIV), influenza virus (A, B) and parainfluenza, Poliovirus, Astrovirus, Parvovirus, Sindbis virus (SINV), Feline calicivirus (FCV), Rhinovirus, Echovirus, Rotavirus, Bovine alphaherpesvirus 1 (BoHV-1), Reovirus, Vaccinia virus (VACV), Cardiovirus A (Encephalomyocarditis virus;EMCV), Coxsackie virus, Semliki forest, Measles virus, Newcastle disease virus (NDV), Coronavirus, Adenovirus (ADV-3, ADV-5, ADV-8, ADV-11), Canine distemper virus (CDV), Lumpy skin disease virus (LSDV), Hepatitis A, B, C virus and Enterovirus. To combat viruses, plants can be considered a potentially invaluable natural resource.

Analytical and biomedical applications of microfluidics in traditional Chinese medicine research

Traditional Chinese medicine (TCM) has significant benefits in the prevention and treatment of diseases due to its unique theoretical system and research techniques. However, there are still key issues to be resolved in the full interpretation and use of TCM, such as vague active compounds and mechanism of action. Therefore, it is promising to promote the research on TCM through innovative strategies and advanced cutting-edge technologies. Microfluidic chips have provided controllable unique platforms for biomedical applications in TCM research with flexible composition and large-scale integration. In this review, the analysis and biomedical applications of microfluidics in the field of TCM are highlighted, including quality control of Chinese herbal medicines (CHMs), delivery of CHMs, evaluation of pharmacological activity as well as disease diagnosis. Finally, potential challenges and prospects of existing microfluidic technologies in the inheritance and innovation of TCM are discussed.Copyright © 2022 Elsevier B.V.

Rejuvenation and Restoration of Surface Water Quality Amid COVID-19 Lockdown: A Comprehensive Review in Indian Context

Rivers are our country's lifeline;however, we have done enough destruction to them which leads to deterioration in water quality. Fortunately, COVID-19 lockdown has brought new life to nature. This encouraged us to outline present review article which discusses pilot impacts of lockdown on six Indian rivers. Few rivers including Ganga showed major improvement at few sites in the assessed parameters such as pH, BOD, DO, FC, etc. The Ganga water at Haridwar and Rishikesh was investigated `fit for drinking' (Class A) while at Kanpur was found fit for `outdoor bathing' (Class B). These improvements can be attributed to strict restriction on human activities during lockdown as there were no or minimum industrial discharge, tourism activities, mass bathing and commercial events near rivers. However, after upliftment of lockdown, these activities will return to their previous state and most likely pollutants will eventually reappear in the water bodies. So, in this review we have reviewed government's existing water pollution control schemes, analysed their limitations and recommended several scopes for improvement. Further research directions in this area have also been highlighted. We believe that plans and actions described in the article, if implemented, will lead to fruitful outcomes in managing water resources.

COVID-19 Lockdown Effects on a Highly Contaminated Coastal Site: The Mar Piccolo Basin of Taranto

The COVID-19 pandemic has had a dramatic socio-economic impact on mankind;however, the COVID-19 lockdown brought a drastic reduction of anthropic impacts on the environment worldwide, including the marine–coastal system. This study is concentrated on the Mar Piccolo basin of Taranto, a complex marine ecosystem model that is important in terms of ecological, social, and economic activities. Although many numerical studies have been conducted to investigate the features of the water fluxes in the Mar Piccolo basin, this is the first study conducted in order to link meteo-oceanographic conditions, water quality, and potential reduction of anthropic inputs. In particular, we used the model results in order to study the response of the Mar Piccolo basin to a drastic reduction in the leakage of heavy metal IPAs from industrial discharges during the two months of the mandated nationwide lockdown. The results show the different behavior of the two sub-basins of Mar Piccolo, showing the different times necessary for a reduction in the concentrations of heavy metals even after a total stop in the leakage of heavy metal IPAs. The results highlight the high sensitivity of the basin to environmental problems and the different times necessary for the renewal of the water in both sub-basins. © 2023 by the authors.

Positive Matrix Factorization as Source Apportionment of Paddy Soil Heavy Metals in Black Shale Areas in Western Zhejiang Province, China

The source apportionment of pollutants is the key to preventing and controlling the pollution caused by heavy metals in soils. The aim of this study was to investigate the main sources of heavy metals in the soils of black shale areas in western Zhejiang, China. Based on geostatistical spatial analysis, this research employed positive matrix factorization (PMF) for the source apportionment of heavy metals in paddy soil. The results showed that contaminated arable soils were concentrated in the western and southern study areas. At least five major sources of heavy metals were screened in this study: natural sources (39.66%), traffic emissions (32.85%), industrial emissions (9.23%), agricultural activities (9.17%), and mining (9.10%). To be specific, Cd was mainly from mining;As originated from agricultural inputs such as fertilizers and pesticides;and Hg, as an industrial pollutant, was transported by atmospheric deposition in the study area. The accumulation of Pb, Zn, and Cu was mainly influenced by natural sources and anthropogenic sources, i.e., traffic emissions, while that of Cr and Ni was controlled by natural sources.

Changes in physicochemical, heavy metals and air quality linked to spot Aplocheilus panchax along Mahanadi industrial belt of India under COVID-19-induced lockdowns.

Positive effects of COVID-19-induced lockdowns on environment are well documented although pre-planned experiments for such analyses and appearance of fish species are lacking. We hypothesize that spotting the fish Aplocheilus panchax along the industrial belt of Mahanadi River near Cuttack in a never seen manner could be due to the regenerated environment. Heavy metals, water and air qualities along with spotting A. panchax in up, mid and downstream of Mahanadi River near Jagatpur industrial basins were analysed during pre-(end of March 2020) and after 60 days of lockdowns (last week of May 2020). An overall 45, 61, 79, 100, 97 and 90% reduction of Fe, Cu, Ni, Cd, Pb and Zn was recorded in the studied area after lockdowns, respectively. Similarly, dissolved oxygen and pH were elevated by 26 and 7%, respectively. Water temperature, conductivity and total dissolved solute levels were reduced by 7, 46 and 15%, respectively, which were again elevated during post-lockdowns during 2021 as observed from the Landsat-8 OLI satellite data. Air NO2, SO2, NH3, PM2.5, PM10 and CO levels were alleviated by 58.75, 80.33, 72.22, 76.28, 77.33 and 80.15%, respectively. Finally, for the first time, about 12 A. panchax fish per 100 m shore line in the area were spotted. The observed lockdown-induced environmental healing at the studied area could contribute to the appearance of A. panchax in the study site and therefore a stringent environmental audit is suggested during post-COVID-19 periods to make the regenerated environmental status long lasting in such habitats.

Protective Disposable Face Masks Used During the COVID-19 Pandemic as a Source of Pollutants in the Aquatic Environment – A Study of Short-Term Effects

The paper examines the impact of protective equipment used during the COVID-19 pandemic on the environment. The impact of protective face masks on the aquatic environment was analyzed in more detailed way. The amount of protective face masks penetrated into the environment as a result of the COVID-19 pandemic and their role in the increase of plastic and microplastic things in the environment was noted. The aim of the work was to study the migration of a number of metals from disposable protective masks into the aquatic environment in the short term. Using the method of atomic absorption spectroscopy, the value of Cu, Pb, Mn, Zn, Fe in the investigated model systems containing protective disposable face masks was obtained by varying the pH of the aqueous medium. It was found that for manganese, lead and iron there is a permanent (Mn) or temporary (Pb, Fe) excess of these metals in the aquatic environment according to national and European standards. The probable possibility of sorption effects and the need for further research in this direction were noted. © 2023, Polskie Towarzystwo Inzynierii Ekologicznej (PTIE). All rights reserved.

Polyurethane With Instant And Persistent Antimicrobial Efficacy Against Bacteria And SARSCoV- 2

Purpose/Objectives: Gram-negative bacteria including E. coli and P. aeruginosa can survive for months on dry hard surfaces, and SARS viruses can persist for days. These contaminated surfaces along with patients' damaged skin barriers, due to wounds or central line insertion sites, increase the risk healthcare-acquired infections (HAI) and subsequent serious complications. Furthermore, with increased frequency and duration of hospitalizations due to the current pandemic, the number of HAIs is on the rise. Currently there are no antimicrobial surfaces that provide both instant and long-lasting antimicrobial protection against a broad spectrum of infectious microbes. Liquid- or radiation-based disinfection techniques are kill microbes quickly, but their effect does not last long before needing reapplication. Antimicrobial surfaces based on heavy metals remain antimicrobial for long durations, but complete disinfection can take hours. In this work, we developed a new class of plant-inspired antimicrobial surfaces and wound dressings that incorporate plant secondary metabolites capable of rapid disinfection (> 4-log reduction) of common bacteria and viruses and maintain their efficacy over time (> 6 months). Methodology: We developed a method for stabilizing naturally antimicrobial essential oils components from plants such as, alpha terpineol (AT) and cinnamaldehyde (CMA), within a polyurethane polymer. Using a modified standard method for evaluating the performance of different nonporous solids (ISO 22196) and median tissue culture infection dose assay, these antimicrobial polyurethane coatings were tested and found to be effective in killing E. coli, P. aeruginosa, methicillin-resistant S. aureus (MRSA), and SARS-CoV-2. The durability of the coatings was tested by linear abrasion, UV and airflow exposure. Application methods such as spray coating and dip coating allow the coating to be applied to a variety of surfaces. Results: Polyurethane surfaces containing 35% AT content (PU-35%AT) showed a ∼5.8-log reduction in E. coli colony forming units per cm2 (CFU/cm2) in under 2 minutes, a shorter time than common commercial disinfectants. Additionally, when subjected to 8 consecutive rounds of inoculation the PU- 35%AT surface reduced the E. coli by >99.99% for all 8 rounds. We achieved a ∼5.8-log reduction of MRSA within 5 minutes on PU-60%AT. The PU-35%AT surfaces showed a 4.0-log reduction in SARS-CoV- 2 in 60 minutes. A PU-70%AT showed a 1.6-log reduction after 10 minutes and maintained virucidal capabilities after 2 weeks. PU+35%AT surfaces maintained a ∼5.3-log reduction in CFU/cm2 in MRSA and E. coli after 1000 abrasion cycles, 12 hours of UV exposure, 25 hours of exposure to -17°C, or 5 months of air flow. Lastly, to demonstrate the coating's real world functionality the PU+35%AT coating was successfully applied to a computer keyboard, cell phone screen protector and medical gauze. Conclusion/Significance: This work demonstrates a novel approach for fabricating a broad-spectrum antibacterial and antiviral polymer surface based on plant essential oil components. This antimicrobial polyurethane coating has not only rapid bactericidal and virucidal capabilities but maintains this efficacy over time. Additionally, the coating can be applied to a variety of surfaces including medical gauze to create wound dressings that significantly reduce bacterial burden and decrease chances of HAIs.

Incorporating field-based research into remote learning: An assessment of soil lead pollution in different land-use types in Los Angeles.

A research-based course was developed to investigate the legacy of soil lead (Pb) pollution in Los Angeles, California. During the course, undergraduate and graduate students collected a total of 270 soil samples for analyses of metal (loid) concentrations in different land-use types (residential, park, and school). Residential soils had significantly higher Pb concentrations than other land uses (p < 0.01) exceeding the California recommended safety level for soil Pb (80 mg/kg) at the highest frequency (64% of samples), followed by schools (42%) and parks (6.0%). Soil Pb from all 87 census block groups was correlated with battery recycling plant and railroad proximity as geospatial indicators of childhood Pb exposure risk. Meanwhile, census block groups with higher Pb levels were correlated with higher percentages of the following population: those without health insurance, without college degrees, with a lower median household income and income below the poverty line, and ethnic and racial minorities (r = -0.46 to 0.59, p < 0.05). Principal component regression models significantly improved soil Pb estimation over correlation analysis by incorporating sociodemographic, economic, and geospatial risk factors for Pb exposure (R2 = 0.58, p < 0.05). This work provides new insights into how topsoil Pb prevails in various land-use types and their co-occurring sociodemographic, economic, and geospatial risk factors, indicating the need for multi-scalar assessment across urban land uses.

COVID-19 lockdown-driven changes in the Ganga River ecosystem in response to human perturbations.

We examined 10 subsurface water, 5 benthic water and 19 sediment (02 cm) samples along a 518 km of the middle segment of the Ganga River to assess the possible improvements that resulted from the industrial shutdown during the COVID-19 pandemic. The sites included the main stem river, tributary confluences, and two point sources, one of which releases metal-rich effluents and the other flushes municipal sewage. We found significant declines in the carbon, nutrient and metal concentrations in both the water and sediment. Even the most polluted zones did not show hypoxia (dissolve oxygen; DO < 2.0 mg L-1) that had been observed in the previous year. Despite a significant decline in carbon and nitrogen as substrates, the activities of extracellular enzymes (EEs), such as ß-D-glucosidase, FDAase and protease in sediment (0-2 cm depth), increased significantly (p < 0.05) in response to the declining metal concentrations resulting from the industrial shutdown. We found strong negative correlations between EE activity and the concentrations of metal pollutants measured in 2019, but the correlations between these variables appeared poor in 2020 (lockdown period). Also, we found large variances (low stability coefficients) during the period of strong anthropogenic effects (2019). The study indicates that industrial sources are important contributors of metal pollution in the Ganga River and has relevance exploring river ecosystem recovery windows for management decisions.

Study of Short-Term Effects on the Soil of Disposable Protective Face Masks Used in the COVID-19 Pandemic

The paper analyzes the impact of personal protective equipment used by the population as a result of the COVID-19 pandemic on the environment. The scale of the additional amount of waste generated as a result of the use of protective face masks, etc. is noted. The globality of the existing problem and its multiparametric impact on the components of the environment are indicated. The short-term effect of a number of disposable protective face masks on the condition of soil by chemical component has been studied. The dependence of leaching of heavy metals from masks on soil acidity was experimentally analyzed, the dynamics of mobile phosphorus and potassium in soil samples was studied. It is shown that the presence of masks in the soil leads to exceeding the standard for zinc content, while for copper content and manganese content exceeding the standard is not observed in the study period, for lead there are fluctuations in content beyond standard value. The need for long-term research on the impact of face masks on the environment, and in particular soils, was noted. © 2022 Trans Tech Publications Ltd, Switzerland.

A Case of Transverse Myelitis After Moderna SARS-CoV-2 Vaccination

Objective: This case report describes a longitudinally-extensive transverse myelitis after Moderna SARS-CoV-2 vaccination. Background: Transverse myelitis (TM) is an inflammatory spinal cord syndrome presenting with acute-to-subacute neurological deficits. A lesion spanning three or more vertebral segments on imaging is considered “longitudinally-extensive.” The TM differential is broad-- among these etiologies, vaccination is a rare but recognized entity. Design/Methods: 60-year-old, right-handed man with chronic right hemisphere stroke with residual left hemiparesis admitted for four days of bilateral lower extremity numbness progressing to weakness and urinary and bowel incontinence 10 days after receiving his second Moderna SARS-CoV-2 vaccination. Examination showed hypotonic lower extremities, proximal greater than distal weakness, a T9 dermatome sensory level, perineal numbness, mildly-reduced rectal tone, and preserved reflexes. MRI spine revealed a longitudinallyextensive, non-enhancing T2-hyperintense lesion spanning T8-T12. CSF analysis demonstrated 5 white blood cells, 1271 red blood cells, 124 glucose, and 55 protein. Aside from mildly elevated ESR and CRP, extensive serum and CSF work-up for other causes of myelopathy, including nutritional/toxic (copper, zinc, heavy metals), infectious (RPR/VDRL, HIV, HTLV, HSV, VZV, West Nile), and rheumatologic (anti-Jo, anti-Mi-2, anti-Ro/La, anti-smith, anti-Scleroderma, anti-dsDNA, anti-ribosomal P, anti-RNP), were unremarkable. Anti-NMO and anti-MOG antibodies were negative. He improved with methylprednisolone 1000 mg daily for five days suggesting an autoimmune etiology. Results: NA Conclusions: Transverse myelitis has a broad presentation and differential, requiring detailed history-taking to determine the cause as management differs between etiologies. SARS-CoV-2 and post-vaccination are known etiologies for TM. Given the timing of our patient's symptom onset after vaccination and thorough exclusion of other causes, we postulate a potentially novel case of TM associated with the Moderna SARS-CoV-2 vaccine. Though post-vaccination myelopathy is potentially debilitating if untreated, it is rare, and the benefits of vaccination appear to outweigh the risks.

Distribution and temporal variability of uranium and toxic metal(loid)s in snow and rainwater from an oil industry and urban area in Thessaloniki-Greece.

The concentrations of uranium and nine elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in snow and rainwater samples were determined. Samples were collected in Thessaloniki-northern Greece in three sites, one in the industrial area close to an oil production power plant and two in the centre of the city. Snow samples were collected during January-February 2019 and 2021 whereas in the case of rainwater, a two-year survey has been performed during 2019 and 2020. The activity concentrations of the uranium radioisotopes were measured by alpha spectrometry whereas the metal(loid)s concentrations were determined by inductively coupled plasma mass spectroscopy (ICP-MS). The elevated concentrations of uranium (U) and the deviation of the isotopic ratio of U-234/U-238 from the equilibrium value indicated intensive dissolution of uranium. The results were analyzed using statistical analysis (Shapiro-Wilk, Friedman and Kruskal-Wallis tests). The obtained data and the calculated enrichment factors (Efs) denote variation of the concentration values between industrial and urban area and different elemental distribution influenced from anthropogenic contributions, meteorological conditions and the COVID-19 pandemic.

Properties of Binder Board Mixed with Chitosan

Recently, as non-face-to-face culture spreads to COVID-19, the time spent indoors is increasing. Accordingly, indoor air quality management has become an important factor. Therefore, the purpose of this study is to evaluate the possibility that chitosan may exist as a building material for reducing air pollutants such as heavy metals and formaldehyde. As a result of the experiment, cement cured binder are better in terms of strength than non-cement cured binder, and as the chitosan substitution rate increases, flexural strength increases and compressive strength decreases. Chitosan has a similar structure to fiber, and chitosan powder has a dispersion-enhancing effect, which is considered to help increase flexural strength. The concentrations of heavy metals and formaldehyde tend to decrease. It is estimated that Chitosan adsorbed fine dust by attracting negative fine dust according to the principle of charge. In addition, it is estimated that heavy metals and formaldehyde were adsorbed due to its excellent chelate properties of chitosan. As a result of the board experiment mixed with chitosan, the durability of the board is excellent as the PVA fiber incorporation rate increases. Therefore, it is judged that this study can be used as basic data for the development of multifunctional building materials by utilizing Kitosan Mountain, which lacks research in the field of building materials. © 2021 Architectural Institute of Korea.

Pediatric reference intervals: Gaps and recent advances

Clinical laboratory reference ranges serve as health-associated benchmarks that enable clinicians to interpret laboratory test results and facilitate clinical decision-making. Unfortunately, critical gaps currently exist in accurate and up-to-date pediatric reference ranges for accurate interpretation of laboratory tests performed in children and adolescents, which may contribute to erroneous diagnosis or misdiagnosis of many diseases. Several initiatives have been established internationally to address these gaps, including the KiGGS initiative in Germany, the Aussie Normals in Australia, the AACC-National Children Study in the USA, the NORICHILD Initiative in Scandinavia, and the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) program in Canada. Since 2009, CALIPER has recruited more than 12,000 healthy children and adolescents, thereby establishing a comprehensive database of pediatric reference ranges for over 185 biomarkers of health and disease (www.caliperdatabase.org). However, evidence gaps continue to exist for special markers and new laboratory instruments. To address these gaps, our team has recently completed or is currently undertaking studies to establish pediatric reference ranges for: 1) chemistry and immunological markers on new analytical systems (Abbott Alinity, Siemens Attelica), 2) hematological markers on multiple platforms (Sysmex, Beckman, Mindray), 3) critical care markers on point of care testing platforms, 4) markers of inflammatory disease (cytokines, calprotectin, autoimmune), 5) markers of nutritional deficiency (essential trace elements), and 6) markers of environmental toxicity (heavy metals). CALIPER is also embarking on specific sub-studies regarding maternal, child, and adolescent health, such as the Mother & Child Health Initiative, COVID-19 Seroprevalence Study, and Lipid Metabolism in Adolescents with obesity. In this presentation, I will review the recent worldwide initiatives on pediatric reference ranges as well as discuss the concept and feasibility of common reference ranges. I will also discuss the progress made by the CALIPER program, the CALIPER database, and future research directions.

[High-frequency Responses to the COVID-19 Shutdown of Heavy Metal Elements in PM2.5 in Shanghai].

To study the evolution and sources of heavy metal elements in the urban atmosphere before, during (overlapped with Chinese Lunar New Year), and after China's COVID-19 shutdown, a multi-metal online analyzer was deployed to determine the trace elements in PM2.5 in Shanghai from January 1 to February 26, 2020. Meanwhile, source apportionment of the hourly measured heavy metal concentrations was performed using a PMF model, in which eight sources were identified. The results show that the concentrations of most elements presented a "V-shaped" trend, which was mainly influenced by emissions from fireworks (K, Cu, Ba as indicative elements), Se-related industry, road dust (Ca, Fe, Ba), and motor vehicles (Mn, Zn, Fe, Cu). However, during the COVID-19 shutdown period, the concentrations of K, Ba, and Cu were high. Case-specific analysis suggested that prior to the shutdown period, the high concentrations of Cu were significantly influenced by long-range transport, which shifted to a dominant contribution from local fireworks during the shutdown period.

Assessment of the surface water quality improvement during pandemic lockdown in ecologically stressed Hooghly River(Ganges) Estuary, West Bengal, India.

The countrywide COVID-19 pandemic lockdown accomplished what aggressive plans could not do throughout the long-term cleaning of the Ganga River. Here, we illustrated Hooghly River surface water quality [physico-chemical parameters, biological parameters, dissolved heavy metals] improvement by analyzing eight sampling station before and during the lockdown. Because of shutdown of industrial units and individuals staying at home, a complete decrease in industrial wastes, contaminants, and self-purging of the stream improved significantly water quality by about 40% to 50%. Among dissolved heavy metals, the concentrations of Cd (50%), Pb (53%), demonstrated noteworthy variations during the lockdown. Diminishing trends were also observed for TDS (62%), and BOD (52%), with significant reduction in the total coliform (63%), faecal coliform (61%), notably. Principal component analysis and paired t-test signify the alteration of water quality. The study concludes that the aquatic ecosystem can be revived if wastewater, and anthropogenic activities are properly managed by environmental surveillance.

Effects of COVID-19 pandemic lockdown on microbial and metals contaminations in a part of Thirumanimuthar River, South India: A comparative health hazard perspective.

Twenty-two water samples from the Thirumanimuthar River course in southern India were collected before COVID-19 lockdown and during COVID-19 lockdown periods and were analyzed for microbiological parameters (fecal coliform bacteria, total coliform bacteria, Escherichia coli, and fecal streptococci) and heavy metals (Fe, Mn, Zn, Cu, Cd, Ni, Pb and Cr). The lockdown has decreased microbial populations and heavy metals. Fe, Cu, Cd, Ni, Pb and Cr exceeded the drinking water limits, respectively, in 77%, 45%, 27%, 18%, 9% and 91% of the pre-lockdown samples. During the lockdown period, Fe, Cu and Cd concentrations in 23% and Cr in 50% of the samples exceeded the limits. Heavy Metal Pollution Index (PI) expressed that 27%, 64% and 9% of the pre-lockdown samples represented 'low', 'medium' and 'high' pollution categories, respectively, but 68% and 32% of the lockdown period samples represented 'low' and 'medium' categories, respectively. The Metal Index (MI) exposed that all samples of pre-lockdown were under the seriously affected category, whereas 54% and 46% of lockdown samples were under strongly and seriously affected categories, respectively. Health risk evaluation predicted that 95%, 91% and 86% of pre-lockdown samples and 45%, 36% and 33% of lockdown period samples were at risk among children, teenagers and adults, respectively. As there is no integrated study on river water quality of COVID-19 lockdown this work is uniquely carried out by combining heavy metal pollution, microbial contamination and human health risk evaluation.