Irrigation Activities Research Articles

Impact of organic matter on arsenic mobilization induced by irrigation in the unsaturated and saturated zones

Organic matter (OM) plays an important role in the biogeochemical transformation of arsenic (As) in groundwater and sediments. High-As groundwater used for irrigation introduces dissolved As into the ground. Moreover, water table fluctuations and variations in redox conditions affect As mobilization in both the unsaturated and saturated zones. A field experiment was conducted at the DY site, Datong Basin, China to explore the effect of OM on As and iron (Fe) mobilization and transformation in the unsaturated and saturated zones during irrigation. Soil water/groundwater and sediments sampled at different depths during the experiment were analyzed to investigate the hydrochemical processes and correlations between As, Fe, and OM concentrations. Irrigation activities led to the accumulation of aqueous As in the saturated zone and increasing As content in the topsoil. Analyses of Fourier-transform infrared (FTIR) spectra suggest the existence of As-Fe-OM ternary complexation. Parallel factor analysis (PARAFAC) of the three-dimensional fluorescence excitation–emission matrix (EEM) reveals that water-extractable organic matter (WEOM) of sediments comprises three major components, two terrestrial humic-like components (C1 and C2) and one protein-like component (C3). And terrestrial humic-like components with high molecular weight promotes As-Fe-OM complexation reactions. The results of this study demonstrate As mobilization under irrigation conditions and contribute to a better understanding of the role of OM under high-As groundwater irrigation. This study has implications for controlling and managing OM or As-contaminated water for irrigation in high-As groundwater regions.

Dinâmica do uso do solo e alterações na vazão na bacia do Rio São Francisco no início do Séc. XXI

The aim of this study is to evaluate the changes occurred in the land use of Sao Francisco river basin (BHRSF), and the their influence in the observed streamflows, for the period from 2001 to 2013. In order to identify changes in land use and land cover, images from MODIS satellite - Moderate Resolution Imaging Spectroradiometer plataform were used through a code developed in the DINAMICA EGO software. The generated product presents informations about the quantification of changes in terms of area and the identification of the type and the location of the occured transitions. To analyze the trend in streamflow behavior, 18 fluviometric stations belonging to the national hydrometeorological network, operated by ANA, were used. The Mann-Kendall statistical test was applied and the results demonstrate some significant land cover transitions such as: Forest to Savanna, Woody to Savanna and Cropland to Savanna. It was also observed in 11 of the 18 fluviometric stations studied, a trend of decreasing streamflow over the years. This result may be explained by the extend irrigation activity performed in the basin. The transitions “Savanna to Cropland” and “Woody to Cropland” are assossiated to high levels of water use, which are responsible for the decrease of water supply in the Sao Francisco river basin, and therefore in the streamflows.

Debris Removal by Activation of Endodontic Irrigants in Complex Root Canal Systems: A Standardized In-Vitro-Study

Aim of the study was to develop a standardized model system to investigate endodontic irrigation techniques and assess the efficiency of different activation methods on the removal of hard tissue debris in complex root canal systems. Mesial roots of mandibular molars were firstly scanned by micro-computed tomography (µCT) and allocated to three groups of irrigant activation: sonic activation (EDDY, VDW, Munich, Germany), laser activation (AutoSWEEPS, FOTONA, Ljubljana, Slovenia) and conventional needle irrigation (control). Roots were fixed in individual 3D-printed holders to facilitate root canal enlargement under constant irrigation with NaOCl (5%). To enable standardized quantification of remaining debris, BaSO4-enriched dentine powder was compacted into the canals, followed by another µCT-scan. The final irrigation was performed using 17% ethylenediaminetetraacetic acid (EDTA) and 5% sodium hypochlorite (NaOCl) with the respective activation method, and the volume of remaining artificial debris was quantified after a final µCT-scan. The newly developed model system allowed for reliable, reproducible and standardized assessment of irrigation methods. Activation of the irrigant proved to be significantly more effective than conventional needle irrigation regarding the removal of debris, which persisted particularly in the apical third of the root canal in the control group. The efficiency of irrigation was significantly enhanced with laser- and sonic-based activation, especially in the apical third.

English

Groundwater is a valuable natural resource whose quality is threatened by natural and man-made pollutants. This study aims to perform a hydrochemical characterization of groundwater resources used for domestic and irrigational activities in Melong (Littoral Cameroon). Thus, 26 subsurface water samples were collected in the dry season (six sampling points) and rainy season (seven sampling points) of the years 2019 and 2020. Physical water quality parameters were measured on the field while ionic constituents and bacteriological parameters were determined in the laboratory. The main findings revealed that the pH of the water samples was slightly acidic to neutral, fluctuating from 5.3 to 7.1; electrical conductivity ranged from 0.03 to 0.33 µS/cm and turbidity varied from 0.5 to 33.7 NTU revealing that the water is weakly mineralized. The ionic constituents were such that Ca2+ > K+ > Mg2+ > Na+ for cationic constituents while anions appeared as HCO3-> NO3- >Cl- > PO43-. The major ions fell within the acceptable limits of World Health Organisation (WHO) drinking water standards. Bacteria indicators of faecal pollution were identified in all the water samples, including Enterobacteria, Escherichia coli, Streptococcus, Salmonella, Shigella, Staphylococcus and Vibrio. This indicates an exposure of water sources to unhygienic conditions that may place consumers at risk of water-borne diseases, hence necessitating basic treatment of the water before consumption.   Key words: Hydrochemistry, Melong, groundwater quality, bacteriological analysis, Littoral Cameroon.

Surface water quality assessment in the semi-arid area by a combination of heavy metal pollution indices and statistical approaches for sustainable management

The current study consists of evaluating surface water pollution using an integrated approach based on pollution assessment indices and statistical approaches (principal component analysis (PCA), logistic regression (LR) analysis, and cluster analysis (CA)). Thirty-four water samples from the High Ziz basin (semi-arid area), occupied by abandoned mine sites in SE Morocco, were collected and analysed for physicochemical parameters and heavy metals (Cu, Zn, Fe, Pb, Ni, and Cd). The mean concentrations of Pb, Zn, Cu, and Fe in the water samples were 41.9 mg/L, 14.8 mg/L, 20.1 mg/L, and 8.1 mg/L, respectively. The large part of the samples is in a near neutral high metal zone based on the plot of heavy metals (Fe+Cu+Pb+Zn+Ni) versus pH. The HPI, HEI, and CI pollution indices were found to average around 586.2, 321.8, and 315.8 respectively, these show strong correlations with heavy metals. The HPI, CI, and HEI values were above 100 as critical pollution index value. These indices indicate that the surface water samples are critically polluted with respect to studied heavy metals. Therefore, the high metal content of the studied samples should be of great concern for the irrigation activity. Moreover, the water quality index (WQI) shows that 76% of the water samples are unsuitable for drinking. The CA analysis grouped 34 samples into four clusters according to the similarity proprieties observed in water quality. Furthermore, the total variance is explained by 75.7% of the water quality with four components according to PCA analysis. Based on LR analysis, the hazard area is strongly correlated with the river system near abandoned mine sites, agricultural and urban areas. The water quality in the study area is controlled by natural/geogenic processes according to the interpretation of pollution indices and statistical approaches (PCA, CA, and LR). The distribution intensity of Pb, Zn, Cu, and Fe metals in the study area's surface water constitutes an environmental concern and needs a monitoring network for sustainable water resources management.

Hydrochemical Evaluation of the Tigris River from Mosul to South of Baghdad Cities, Iraq

Aims of this Study: To investigate the climate change{effects in Iraq on the quality and quantity of the water of the Tigris River from {Mosul” city to South of Baghdad city.00 This paper provides a review of the observed and the predicted impacts of climate change on the water quality in the Tigris River in Iraq.
 Study Design: Cross-Sectional study.
 Place and Duration of Study: The study area is starting {from Mosul city which is located in {the north part of Iraq to the Al-Azziziyah city located in the south of Baghdad (2005-2012) .
 Methodology: The current study was include the available historical data which are the discharge and hydrochemical analysis includes (Ca, Mg, Na, K, Cl, SO4, HCO3, TDS,NO3, and EC) were taken from 6 stations along the Tigris’ River from Mosul to the south of Baghdad’ cities for the years 2005 to 20112. The available historical climate data’ includes (Rainfall and Temperature) for the period 1990-2012. In this paper also, used some of pervious studies and compared them with the current results.
 Results: The average annual flow of the Tigris River in Mosul station for the period (1990-2012) ranged between’ (193.8-906) m3/sec and for Sammarra station ranged between’ (366-977) m3/sec. Then, between south of Sammarra’city and north of Baghdad city, Canal of Dijla’joins the Tigris River has a discharge ranges between’ (9-217) m3/sec. After that, the ’Tigris River inter to Baghdad city, the discharge value range between’ (392-1173) m3/sec’and continue his flow to the south of Baghdad city and Diyala River joins it with discharge’range between (55-193) m3/sec. Finally, the Tigris River reaches to’Al-Azizziyah city station with’discharge ranges between (134-769) m3/sec.
 Conclusion: In general the water quality of the Tigris River are sulfates, calcium, and magnesium. But in Canal of Dijla the most dominant ion is sodium due to agricultural activities and geology of the area consist of gypsum rocks and this can be effects on water quality of Tigris River in the next station (Baghdad). In Al-Azizziyah city the sulfates, calcium, and Sodium is high level due to drainage from irrigation, industrial“and domestic activities.

Effect of Irrigating Agitation after Root End Preparation on the Wall Cleaning and Bond Strength of Calcium Silicate Material in Retrograde Obturation.

Objective This study aimed to evaluate the cleaning efficacy of irrigant activation with a new ultrasonic tip in root-end preparations and to determine its influence on the bond strength of calcium silicate-based material. Materials and Methods Maxillary canines were prepared and filled, and their root ends resected. Root-end cavities were ultrasonically prepared and randomly distributed into four groups according to the final irrigation protocols: G1 (ultrasonic irrigation [UI] + saline solution [SS]), G2 (syringe irrigation [SI] + SS), G3 (UI + ethylenediaminetetraacetic acid [EDTA]), and G4 (SI + EDTA). Cleaning efficacy analysis employed 72 specimens ( n = 18) split longitudinally for imaging of the same areas by scanning electron microscopy (SEM). The percentage of dentinal tubules opened before and after irrigation was used as evaluation parameter. Push-out testing employed 40 specimens ( n = 10) sectioned apical region perpendicularly, which slice was placed on a testing machine for the bond strength measurement and failure mode was assessed by SEM. The data were statistically analyzed (α ≤ 0.05). Results G3 (UI + EDTA) removed the smear layer more effectively, showed the best tubule opening ( p < 0.05), and presented the highest mean bond strength values ( p < 0.05). Failure modes were predominantly adhesive, except for the G3 (UI + EDTA) group, in which they were mainly mixed (80%). Conclusion The results of this study suggest that EDTA 17% agitation promoted better cleaning and smear layer removal, improving the push-out bond strength of calcium silicate material in retrograde obturation.

SINGLE VISIT REVASCULARIZATION OF MATURE TEETH USING SONIC ACTIVATION PROTOCOL (A CASE SERIES)

Revascularization has been commonly known to be limited to the immature teeth. Owing to its promising results, it was suggested as another treatment option to conventional endodontics in mature teeth. Single visit revascularization is still an area of evaluation and was developed to reduce the drawbacks of multiple visits. This report described the outcomes of single visit revascularization both clinically and radiographically in necrotic permanent mature teeth with chronic apical periodontitis after irrigation activation using sonic disinfection protocol. Twelve cases of permanent mature teeth were recruited into the study. Canals were prepared till file X4 Protaper next system. For disinfection protocol, sonic activation (Endoactivator) was used to agitate sodium hypochlorite (2.5%) for sixty seconds followed by 20 ml of 17% EDTA. The bleeding was then induced and Biodentine was placed over blood clot. Glass ionomer was used as a base then composite as final restoration. Treatment outcome was evaluated for 12 months period. After 12 months of follow-up, all teeth showed the absence of clinical signs and/or symptoms and evidence of periapical healing radiographically. Four teeth regained vitality by the end of 12 month period. Favorable outcome for single visit revascularization procedure when activated with sonic irrigation in mature single-rooted teeth with chronic apical periodontitis.

Critical review on hazardous pollutants in water environment: Occurrence, monitoring, fate, removal technologies and risk assessment

Water is required for the existence of all living things. Water pollution has grown significantly, over the decades and now it has developed as a serious worldwide problem. The presence and persistence of Hazardous pollutants such as dyes, pharmaceuticals and personal care products, heavy metals, fertilizer and pesticides and their transformed products are the matter of serious environmental and health concerns. A variety of approaches have been tried to clean up water and maintain water quality. The type of pollutants present in the water determines the bulk of technological solutions. The main objective of this article was to review the occurrences and fate of hazardous contaminants (dyes, pharmaceuticals and personal care products, heavy metals, and pesticides) found in wastewater effluents. These effluents mingle with other streams of water and that are utilized for a variety of reasons such as irrigation and other domestic activities that is further complicating the issue. It also discussed traditional treatment approaches as well as current advances in hazardous pollutants removal employing graphite oxides, carbon nanotubes, metal organic structures, magnetic nano composites, and other innovative forms of useable materials. It also discussed the identification and quantification of harmful pollutants using various approaches, as well as current advancements. Finally, a risk assessment of hazardous pollutants in water is provided in terms of the human health and the environment. This data is anticipated to serve as a foundation for future improvements in hazardous pollutant risk assessment. Furthermore, future studies on hazardous pollutants must not only emphasize on the parent chemicals, as well as on their possible breakdown products in various media.

Impact of small-scale irrigation on household food security: evidence from Ethiopia

BackgroundAdamitulu Jido Komoblcha is one of the districts located in lowland areas of the Oromia region with irrigation potentials of 14,000 hectares out of which only 2568 hectares are under small-scale irrigation practices. Though there are a lot of households using irrigation in the study area, the impact that it has brought on the food security of the household is not yet well studied in the area. Several related studies reviewed lack appropriate impact evaluation methods in studying the impact of small-scale irrigation on food security that may result in overestimation or underestimation of the impact. To this end, the main motivation behind this study was to examine whether small-scale irrigation in the study area is creating positive change on household food security or not using the propensity score matching approach.MethodologyBoth primary and secondary data were collected and used in the study. The primary data were collected from randomly selected 94 irrigation users and 100 non-user households from February to March 2018. Secondary data were collected from a review of different works of literature. Both descriptive statistics and econometric models were applied to analyze the data using Stata software version 13. The study applied the propensity score matching (PSM) model to analyze the impact of small-scale irrigation on food security. In analyzing the impact of small scale irrigation on food security, we have used calorie intake, crop harvest and consumption both from own production and bought from the sale of the crop harvest produced through irrigation as an indicator of food security.ResultThe study has found that participation in irrigation is positively determined by age, education, land size, access to extension service, and participation in off or non-farm activities. In contrast to this, participation in irrigation is negatively determined by distance from farm plot to water source and distance from the main market. The results of the nearest neighbor and caliper matching estimators show that participation in small-scale irrigation increased the daily calorie intake of the small-scale irrigation users by 643.76 kcal over non-user households. Similarly, it increased their daily calorie intake to 596.43 kcal and 591.74 kcal, respectively, with radius and kernel matching estimators. The result further indicted that irrigation had positive impact on crop production, consumption and revenue generation which all together indicated improvement in food security. The sensitivity analysis test shows that impact results estimated by this study were insensitive to unobserved selection bias which shows it is a real impact of the irrigation.ConclusionIt was concluded that irrigation has a positive and significant impact on household food security. Concerned bodies that working on small-scale irrigation development therefore should continue investment in irrigation activities for poverty reduction strategies and scale-up irrigation interventions to the other areas where there is potentially irrigable land.

The effect of different irrigation solutions and activation techniques on the expression of growth factors from dentine of extracted premolar teeth.

To evaluate in a laboratory study, the effect of different canal irrigant solutions and activation techniques on transforming growth factor (TGF-β1), insulin growth factor-1 (IGF-1), bone morphogenetic protein-7 (BMP-7) and vascular endothelial growth factor-A (VEGF-A) release levels from the dentine of extracted premolar teeth. Seventy premolar teeth with single root and canal were used. The lengths of the root segments were standardized to 12mm, and the root canals were prepared up to size 100 with hand files. All surfaces of the teeth were covered with nail polish except the inner root canal surface. The root canals were irrigated with 1.5% NaOCl. Ten teeth were allocated to the control group. The remaining sixty teeth were divided into 2main groups according to the chelating agent used (17% EDTA, 10% Citric acid; CA) and 3subgroups (n=10) according to irrigation activation technique (conventional syringe irrigation (CSI), passive ultrasonic irrigation (PUI) and Er:YAG laser activation). After the activation procedure, the root segments were placed into eppendorf tubes containing 1mL of phosphate-buffered saline solution and kept at 37℃. TGF-β1, IGF-1, BMP-7 and VEGF-A release levels from dentine were measured using the enzyme-linked immunosorbent assay (ELISA) method at 24 h and at day 7. The volume of root canals was calculated using cone-beam computed tomography. The growth factor levels were calculated in ng/mL except VEGF-A (pg/ml). Normality analysis of the data was evaluated with the Kolmogorov-Smirnov test. Statistical analysis was performed using the Mann-Whitney-U and Wilcoxon tests. Regardless of the activation type and sampling time, EDTA caused significantly more IGF release than did CA, whereas EDTA and CA were equally effective for the release of the other growth factors. For either EDTA or CA, the lowest and highest growth factor release levels were observed in the CSI and Er:YAG laser groups, respectively (p<.05). All of the growth factors were released significantly more at 24 h than on day 7 (p<.05). Irrigation activation techniques with EDTA or CA increased the release levels of all growth factors from the dentine of canal walls in extracted premolar teeth.

Analysis of Double-diffusive natural convection in a solar distiller embedded with PCM and cooled with external water stream

BackgroundThe increase demand of water for irrigation and human activities leads to a global development of alternative methods to produce distillate water especially from sea. In this context, the use of solar distiller instead of the classic distillation process is a good solution to preserve environment and reduce the use of fuel. This study explores the advantages of the classic solar still by studying the effect of the PCM-RT42. Hence, a detailed investigation of the heat and mass transfer of a single slope solar still incorporation PCM-RT42 as heat storage system will be presented. MethodsThe governing equations are solved numerically with employing the finite volume method. The next scopes of parameters are utilized in the computations: dimensionless time (τ = 4.2×10–3, 25.2×10–3, and 50.4×10–3), Rayleigh number (104 ≤ Ra ≤ 106), buoyancy ratio (1 ≤ N ≤ 5). Mixture Prandtl number (Prm), Schmidt number (Sc) and Lewis number (Le) are presumed as fixed to 0.705, 0.613 and 0.869, respectively. Significant FindingsThe results show the good effect of the PCM-RT42 on the transfer of heat and mass compared to the initial time for low Ra. However, for Ra=105 and 106, a reduction in the efficiency of condensation and the performance of the solar distiller is observed.

Physico-chemical assessment of waters used to irrigate agricultural lands of Amazon

The use of pesticides / fertilizers in plantations has become a problem in maintaining the quality of surface water. Thus, the objective of this study was to evaluate the water quality for irrigation purposes in the Rio Apéu microbasin – Para. The physico-chemical parameters evaluated were: pH, DO, SAR, TDS and EC measured in situ and the metals Al, Fe, Na, Ca, Mg determined in the laboratory Evandro Chagas Institute, according to the method of APHA. The average levels of pH (5.51), OD (5.04 mg L-1) are indications of normal condition in Amazonian waters. The results of Al (332 mg L-1) and Fe (5.74 mg L -1) imply the leaching of sediments from the geological formation of the region rich in these minerals, even though they present values above what is recommended by the legislation. The Richard classification allowed us to define that the waters of the study area have low salinity and sodicity, so they are not restricted to use. Thus, the results of the water quality analysis in the watershed can be concluded that it does not offer environmental problems in the use for irrigation activity

Effect of Different Final Irrigation Activation Methods on Root Canal Cleanliness

Aim: to evaluate canal cleanliness after using manual dynamic activation, passive ultrasonic irrigation and photoactivated disinfection in comparison with conventional needle irrigation, using scanning electron microscopy Methods: Sixty single rooted human premolars with nearly straight single canal were collected, the crowns of all teeth were removed near the level of cementoenamel junction to obtain approximately 15 ±1 mm uniform root lengths. After instrumentaion with ProTaper Next files up to X4 (40/06), roots were randomly divided into 4 equal groups (n=15) according to the method of final irrigation activation. Group I: Conventional needle and syringe irrigation. Group II: Manual dynamic activation. Group III: passive ultrasonic irrigation. Group IV: photoactivated disinfection. Canal cleanliness was evaluated with SEM using different magnification (X350- X1000). Results: Group III had the best cleanliness of the root canal while Group I had the worst cleanliness, there were statistical significant differences between Group I versus Groups II and III and between Group III and Group IV (P ≤ 0.05). Regardless the irrigation activation method, the coronal level showed significantly less amount of smear layer and remaining debris than the apical level. Conclusions: None of the tested final irrigation activation methods resulted in completely clean canal wall.

Recent Advances in Endodontics – A Perspective Review

Contemporary endodontics has seen an unprecedented advance in technology and materials. This article aimed to review some of the challenges and advances in the following sections: (1) Magnification, (2) LASER, (3) NiTi files, (4) Irrigation activation systems, and (5) CAD CAM. Jointly, these advances are aimed at improving the state of the art and science of root canal treatment and restoring the tooth back to function in the oral cavity

Efficacy of finisher files in the removal of calcium hydroxide paste from the root canal system – preliminary results

Introduction. Successful endodontic treatment is affected by a number of factors associated with the disinfection and filling of the root canal. The chemical-mechanical root canal preparation consists in a thorough removal of any content from the pulp space, including inflamed pulp, bacteria, as well as canal filling materials. Aim. The aim of the study was to analyse the efficacy of the XP-endo Finisher and the Brush-Finisher on the removal of a calcium hydroxide dressing. Material and Methods. The study was conducted using extracted single-rooted human teeth prepared according to sample standardization. Calcium hydroxide with iodoform was inserted into the canals. After two weeks, canal cleaning was performed with the use of 2% sodium hypochlorite solution and both finisher files. A conventional endodontic needle and syringe (SNI) were used in the control group. Following rinsing activation, two projection radiographs were performed and uploaded to software developed specifically for the study. The graphic files were evaluated in terms of the remaining amount of dressing. In order to analyse whether the percentage of the canal area that remained untreated was statistically significant, the Kruskal-Wallis ANOVA test with Dunn’s post-hoc test were employed. Results. The intracanal dressing was most effectively removed in the XP-endo Finisher group (in both projections 96.32% and 91.35%), and its removal was considerably better than that in the control group (p&lt;0.0001), although not significantly different from the Brush-Finisher group (89.68% and 81.85%). Conclusions. Supplementary irrigant activation with either the XP-endo Finisher or the Brush-Finisher improved the removal of calcium hydroxide from the root canal walls.

Effect of Different Irrigation Activation Techniques on Sealer Penetration: A Confocal Laser Microscopy Study.

To compare the efficiency of a new sonic powered irrigation system named EDDY (VDW, Munich, Germany), passive ultrasonic irrigation (PUI) and conventional needle irrigation (CNI) in root canal sealer penetration. A total of 45 mandibular premolars were instrumented up to size 30, 0.9 taper and randomly divided into three groups (n = 15) depending on the final irrigation activation technique: EDDY, PUI or CNI. After the final irrigation procedures, the root canals were obturated with labelled sealer mixed with 0.1% rhodamine B. Transverse sections at 3, 5 and 7 mm from the root apex were examined using confocal laser scanning microscopy. The maximum depth and total area and percentage of sealer penetration were measured using ImageJ analysis software (National Institutes of Health, Bethesda, MD, USA). In the EDDY group, the penetration depth was higher compared to the CNI group in the apical and middle sections and compared to the PUI group in the apical section (P ˂ 0.05). The penetration area in the EDDY group was higher compared to the CNI group in all sections and compared to the PUI group in the coronal section (P ˂ 0.05). The percentage of penetration was higher in the EDDY group compared to the CNI group in all sections and compared to the PUI group in the coronal section (P ˂ 0.05). In the present study, sealer penetration was superior in the EDDY group than the CNI group in the apical section. In the middle and coronal sections, sealer penetration was similar for the EDDY and PUI groups.

Salinity and Sodicity Status of the Floodplain Soils of Kebbi State, North Western, Nigeria

Floodplain soils are the sites for most of agricultural activities during dry seasons. With efficient irrigation facilities such as tube wells and water pumps, they can produce 2-3 short duration crops during a year. However, due to persistent irrigation activities, these soils are always susceptible to salinization and sodicity hazards. High salt content in the soil inhibits uptake of plant nutrients and water, while high sodium content in sodic soils destroys soil structure and consequently reduces the rate of permeability and aeration. In view of this, it becomes necessary to assess the level of salinity and sodicity of the floodplain soils of the study area; Augie, Argungu, Birnin Kebbi and Bunza Local Government Area of Kebbi State, so as to ascertain the appropriate management practices to be applied on these soils. Soluble salts were as such analyzed. It was observed that the calcium (Ca2+), magnesium (Mg2+), potassium (K+) and Sodium (Na2+), were in the value of 1.90cmol(+)kg-1, 1.66cmol(+)kg-1, 0.16cmol(+)kg-1, and 0.34cmol(+)kg-1, respectively. Salinity and sodicity determinants were also analyzed where pH was observed to be 6.88, electrical conductivity (EC) 0.19dSm-1 exchangeable sodium percentage (ESP) 2.09%. The data were subjected to statistical analysis so as understand the relationship between the four local government areas. Based on the concentration of pH, EC and ESP, the soils could be said to be free from salinity and sodicity hazards at least for now. However, due to the high concentration of Mg2+, K+ and Na+, the soils could be said to have potential threat to salinity and sodicity problems and therefore proper management strategies should be practiced to prevent their further concentration.

Cleaning efficacy and uncontrolled removal of dentin of two methods of irrigant activation in curved canals connected by an isthmus.

The aim of this study was to compare the efficacy of UAI with ESI, sonic activation with Eddy® and syringe irrigation in removing debris, and dentin removal during canal irrigation. Twenty-four mandibular molars containing isthmus type V and with a mean curvature of 32.5° were instrumented and divided into three groups for final irrigation: UAI with ESI, sonic activation with Eddy and syringe irrigation. The samples were scanned in a SkyScan 1172 micro-CT device for pre-, post-instrumentation and post-irrigation images and analysis of dentin removal. Statistical analysis was performed using Wilcoxon, Kruskal-Wallis and Dunn tests. UAI and sonic activation significantly improved debris removal (P < 0.05). No significant difference was observed regarding dentin removal between the groups (P > 0.05), although higher values were found for UAI. Sonic activation with Eddy® showed to be an effective and safe device since it was able to remove debris without causing damage to the canal walls.

Cyanobacterial Toxins and Peptides in Lake Vegoritis, Greece

Cyanotoxins (CTs) produced by cyanobacteria in surface freshwater are a major threat for public health and aquatic ecosystems. Cyanobacteria can also produce a wide variety of other understudied bioactive metabolites such as oligopeptides microginins (MGs), aeruginosins (AERs), aeruginosamides (AEGs) and anabaenopeptins (APs). This study reports on the co-occurrence of CTs and cyanopeptides (CPs) in Lake Vegoritis, Greece and presents their variant-specific profiles obtained during 3-years of monitoring (2018–2020). Fifteen CTs (cylindrospermopsin (CYN), anatoxin (ATX), nodularin (NOD), and 12 microcystins (MCs)) and ten CPs (3 APs, 4 MGs, 2 AERs and aeruginosamide (AEG A)) were targeted using an extended and validated LC-MS/MS protocol for the simultaneous determination of multi-class CTs and CPs. Results showed the presence of MCs (MC-LR, MC-RR, MC-YR, dmMC-LR, dmMC-RR, MC-HtyR, and MC-HilR) and CYN at concentrations of <1 μg/L, with MC-LR (79%) and CYN (71%) being the most frequently occurring. Anabaenopeptins B (AP B) and F (AP F) were detected in almost all samples and microginin T1 (MG T1) was the most abundant CP, reaching 47.0 μg/L. This is the first report of the co-occurrence of CTs and CPs in Lake Vegoritis, which is used for irrigation, fishing and recreational activities. The findings support the need for further investigations of the occurrence of CTs and the less studied cyanobacterial metabolites in lakes, to promote risk assessment with relevance to human exposure.