Percent Cover Research Articles

Determination of Biological Control Agent Bacteria Against Crown Gall

This study was carried out to determine new bioagent bacteria for in vitro and semi-in vivo biological control of crown gall disease [Rhizobium radiobacter (Agrobacterium tumefaciens)]. A total of 2012 potential bioagent bacterial strains belonging to different genera were tested in vitro against the pathogen. Microbial identification systems (MIS) diagnoses of bioagent bacterial strains found to be effective as a result of in vitro tests were supported by some conventional tests. Then, the strains' semi-in vivo biocontrol activities found to be effective were tested in carrot slices and squash fruits. Statistical analysis of the data was made according to the percentage of surface coverage in carrot slices and the number and size of tumors in squash fruits. Then, the most effective bioagent and pathogenic bacterial strain diagnoses were determined molecularly. According to the results; 106 bioagent bacterial strains (66 antibiosis; 40 hyperparasitic effects) were found to be effective against R. radiobacter in vitro conditions. It was determined that conventional test results of bioagent bacteria and MIS results supported each other. As a result of semi-in vivo biocontrol activity, it was determined that 8 bioagent bacterial strains out of 106 bioagent bacterial strains did not produce pectolytic activity, and 8 bioagent bacterial strains could be evaluated as a result of semi-in vivo test. The most effective strain suppressing the development of the pathogen in carrot slices and squash fruits was RK 1986 (carrot slices 1.78±0.47; squash fruits 0.26±0.04), followed by RK 570A (carrot slices 2.89±0.82; squash fruits 0.35+0.03) and RK 1074 (carrot slices 3.44±0.99; squash fruits 0.46±0.05) strains were followed. According to the results of molecular identification, the most effective bioagent bacterial strain (RK 1986) was Bacillus mojavensis, and the pathogenic bacteria strain (1B) was R. radiobacter.

Fetal growth restriction: features of anamnesis, outcomes of pregnancy and childbirth

Background. Fetal growth restriction (FGR) is a serious medical and social problem, which is associated with high perinatal morbidity and mortality, as well as long-term consequences for offspring. To date, there are no absolute instrumental tests for accurately predicting the condition of the fetus, which justifies the relevance of this study.Objective. To study the features of the anamnesis, the course of pregnancy, and the outcome of childbirth in women with fetal growth restriction.Materials and methods. A retrospective cohort study was conducted using a continuous sample of 200 women who were delivered at the Clinic of the South Ural State Medical University (Chelyabinsk) in 2022. All the women were divided into two groups: group 1 - 30 women with FGR, group 2 - 170 women without FGR. The outcomes of pregnancy and childbirth were studied (the results were obtained by means of a questionnaire, analysis of medical documentation: the book of a pregnant woman, the history of childbirth).Results. There was a low effectiveness of the prognosis of FGR both according to the results of the analysis of anamnestic risk factors and according to laboratory and instrumental screening programs at 11-13,6 weeks of gestation. A low percentage of coverage with drug prevention was registered in the high-risk group of FGR (55%). We found that FGR is associated with other placental disorders, which more often began in the second trimester with changes in uterine and fetal blood flow and progressed as the gestation period increased. Fetal growth restriction is associated with severe preeclampsia, high incidence of premature birth, cesarean section, hypotrophy and severe asphyxia of newborns.Conclusion. The absence of significant anamnestic risk factors, the low effectiveness of predicting fetal growth retardation based on the results of programmatic screening at 11-13,6 weeks require the development of new modern methods for predicting pathology. Research should focus on the development of new fetal diagnostic tools that can improve the accuracy of predicting critical fetal conditions, as well as on the introduction of innovative therapeutic measures aimed at improving placental hemodynamics, which will further optimize the timing of delivery.

The hybrid approach to monitoring: a remote Rapid Assessment Protocol (RAP) complements existing monitoring tools for oyster restoration and management

Accurate and efficient monitoring of oyster reefs is critical for fisheries management and restoration. However, monitoring subtidal reefs requires labor‐intensive methods, such as sampling by SCUBA divers. A new Rapid Assessment Protocol (RAP) based on the collection of underwater imagery from random replicate points across a reef expands the toolkit for oyster reef monitoring. This study tests how the qualitative RAP compares to existing quantitative monitoring tools to inform approaches that combine methods and improve monitoring. We surveyed paired unrestored harvested reefs and restored sanctuary oyster reefs in the upper, middle, and lower Chesapeake Bay (United States) to compare the RAP to diver‐collected oyster metrics across management types and salinities. At each site, we compared the RAP's categorical habitat scores (based on percent cover and relative reef height in images) with physical metrics from synchronous diver collections, including live oyster density and biomass, on the same reef quadrats (n = 64). High RAP scores successfully captured high oyster density, biomass, reef height, rugosity, and multiple size classes. At lower RAP scores, the physical metrics often differed between RAP scores on unrestored harvested reefs, but not restored sanctuary reefs. This study highlights the value of underwater video in increasing monitoring efficiency with respect to time investment, while providing different habitat data than physical metrics. We describe how the RAP can be used in combination with more intensive, physical monitoring tools for restoration and fisheries management. The results of the RAP can inform oyster management in Chesapeake Bay and can be adapted for use worldwide.

Structural Adaptations of the Anterolateral Complex of the Knee and Associated Tissues: A Comparative Anatomical and Histological Analysis of Knees With and Without an Anterolateral Ligament.

The anterolateral ligament (ALL) is considered a secondary stabilizer of internal rotation and, due to proximity to the lateral collateral ligament (LCL), it may contribute to anterolateral rotatory stability. This study characterized the anatomy of the ALL and associated tissues of the anterolateral complex (ALC) to determine if structural and histological compensatory adaptations exist in patients without an ALL. Forty-nine cadaveric knees were dissected from distal-to-proximal using established landmarks with the aid of internal rotation stress to localize the ALL (if present), LCL, iliotibial band (ITB), and anterolateral capsule. The width and thickness of ALL and LCL were measured with digital calipers at the origin, middle, and insertion, and cross-sectional areas were calculated. ALL and LCL length and ITB thickness were also obtained. Samples of each tissue were stained with hematoxylin and eosin and picrosirius red, and histological images were evaluated with ImageJ to quantify collagen density (mean gray value [mgv]) and quantity (percent coverage). Size measurements and collagen characteristics were compared between ALL-present and ALL-deficient knees. The ALL was identified in 63% of knees with mean cross-sectional areas of 8.9, 5.8, and 9.7 mm2 at the origin, middle, and insertion, respectively. Mean collagen density of the ALL was 106.9 mgv on a scale of 0 (black) to 255 (white), and overall collagen quantity was 40.3%. Proximal LCL width (p = 0.04), distal LCL thickness (p = 0.03), and cross-sectional area (p = 0.01), and ITB thickness (p = 0.02) were significantly greater in ALL-deficient knees. A significantly higher collagen density was found within the LCL (p = 0.04), and higher overall quantity of collagen within the LCL (p < 0.01) and ITB (p < 0.01), of ALL-deficient knees. Gross anatomical and histological alterations exist in knees without an ALL compared with those with an ALL. These may reflect adaptations in the ALC and LCL that are present to compensate for the absence of the anterolateral rotatory stability afforded by the ALL.

The ambiguous role of partially protected marine protected areas in Australia: Results from a systematic literature review.

Marine protected areas (MPAs) are an important tool in helping to protect biodiversity in the oceans. Recent ratification of the Kunming-Montreal Global Biodiversity Framework (GBF) has ensured that globally we are committed to effectively protecting 30% of the world's oceans by 2030, in MPAs. In Australia there is considerable interest in the potential benefits that partially protected areas (PPAs) may provide. However, a consistent definition of a PPA is currently lacking, and urgently needed to conduct quantitative analyses of PPAs. We conducted a systematic literature review to understand the current knowledge surrounding PPAs and their potential benefits. We define a PPA, characterise PPA implementation in Australia, and present results for the outcomes of PPAs in terms of ecological, economic, and social indicators. Our review suggests that although 45% of Australia's marine environment is within MPAs, 61% of MPAs provide only partial protection. The Northern Territory (100%), New South Wales (81%), and Queensland (79.8%) have the highest percentage of MPAs that are partially protected, compared to Tasmania which has the smallest percentage of partially protected MPAs (13.12%). Tasmania also has the smallest percentage cover of MPAs (6.49% state waters). Most PPA management plans did not contain quantifiable Key Performance Indicators (KPIs) to be able to effectively monitor the progress of these PPAs against the stated outcomes. We find the benefits of PPAs to be ambiguous: PPAs generally provide benefits when compared to 'open' ocean, however this is not a consistent result. There are no PPAs that provide greater overall benefits when compared to fully protected MPAs. Only one state (South Australia) and the Commonwealth (Australian Marine Parks) are collecting publicly available baseline data to facilitate quantitative monitoring of PPAs. Contrary to fisheries management, there were no plans of action if the declared MPAs and PPAs failed to meet their declared objectives and goals. Some PPAs within Australia appear to be incompatible with conservation priorities according to the recent "MPA Guide" classification framework. This study highlights the need for clearer management rationale and plans for PPAs in Australia, as these comprise the majority of MPAs in Australia's Exclusive Economic Zone.

Long-term Retrospective Case Series of the Pinhole Surgical Technique.

The Pinhole Surgical Technique (PST) was first described in the International Journal of Periodontics and Restorative Dentistry (IJPRD) in October 2012, in a case series involving 43 patients with 121 recession defects, including follow-up data for 37 patients with 85 Miller Class I-II recession defects over an average period of 20.0 ± 6.7 months. The current study provides a long-term follow-up assessment of 28 patients with 68 Miller Class I-II sites from the original study, with an average follow-up period of 173.8 ± 32.2 months (14.5 ± 2.7 years). The percentage of complete root coverage (CRC) for Class I-II sites was 81.2% in the original study and 77.9% in this follow-up study. The mean root defect coverage was 94.0% ± 14.8% in the original study and 86.6% ± 27.4% in the follow-up study. Within the limitations of this study's design, PST demonstrates long-term predictability and effectiveness in achieving sustained root coverage over an average period of 14.5 years.

Coronally Advanced Flap with a Xenogeneic Collagen Matrix or a rhPDGF-BB-regenerative approach for Bilateral Multiple Gingival Recessions: A Split-mouth Clinical Feasibility Study.

This split-mouth trial investigated the efficacy of treating bilateral gingival recessions with either a xenogeneic cross-linked collagen matrix (CCM), or recombinant human platelet derived growth factor (rhPDGF-BB) with a bone allograft (AG). Ten patients were treated with the coronally advanced flap (CAF), either with a CCM, or rhPDGF-BB &#43; AG. The primary outcome was percentage of mean root coverage (mRC) at 12 months. Additional outcomes included clinical, volumetric, patient-reported outcome measures (PROMs) and ultrasonographic assessment of gingival thickness (GT) and position of the buccal bone (uBD). At 12 months, both groups showed significant improvements, with a mRC of 78.6% in the CCM group, and 82.3% for the rhPDGF-BB &#43; AG sites. 3D analysis of both groups showed comparable volumetric gain. CCM-treated sites displayed higher ultrasonographic echogenicity in GT (p<.01) than rhPDGF-BB &#43; AG sites. The rhPDGF-BB &#43; AG group showed greater reduction in the buccal bone dehiscence (mean 2.03 mm, p<0.01), less swelling during the first three days, and slighty greater mean root coverage. CCM and rhPDGF-BB &#43; AG showed to be effective in the treating multiple adjacent gingival recessions. CCM promotes greater gain in gingival thickness, while rhPDGF-BB &#43; AG resulted in a significantly less buccal bone dehiscense.

Surface runoff estimation at the Densu River Basin using geographic information system (GIS) and remote sensing (RS)

Accurate estimation of runoff depth and volume is essential for effective watershed management. Runoff, resulting from rainfall, is influenced by numerous factors, including soil type, vegetation, land use patterns, and rainfall characteristics. The Densu River Basin, located in the Greater Accra region of Ghana, has experienced flooding incidents, partly attributed to changes in land use and land cover. To address these challenges and facilitate proper flood management, drainage network design, hydropower generation, and other applications, this study aims to estimate surface runoff depth in the Densu River Basin, Ghana. The Natural Resources Conservation Services Curve Number (NRCS-CN) method, combined with Geographic Information System (GIS) and Remote Sensing (RS), is employed for runoff depth estimation. The research involves supervised classification of Landsat images from 2001, 2011, and 2022 to determine land use patterns, calculate grass cover percentages, identify hydrologic soil categories, extract rainfall intensity data, compute maximum soil storage, and estimate runoff depths for 10 year, 25 year, and 50 year return periods. The study reveals a significant increase in direct surface runoff depth, from 138.29 mm to 144.70 mm, for soil type D (Clay loam), the dominant soil type in the basin, during the 10 year return period, attributed to changes in land use and climate within the basin. The findings from this study hold valuable insights for mitigating environmental hazards in the area and improving water resource management.

Recreational Fisher Local Ecological Knowledge Provides Information Applicable to the Management of an Anthropogenically Impacted Estuary

ABSTRACTAnthropogenic impacts to estuaries are increasing globally, and often exceed the capacity of resource managers to effectively quantify environmental changes, design and implement effective restoration programs, or assess ecosystem response to specific restoration projects. We interviewed recreational fishers to document spatiotemporal fishing effort over a 40‐year period, analyzed commercial fishing landings, to qualitatively compare the data to seagrass monitoring estimates of aerial coverage and percent cover over a four‐decade period for the Indian River Lagoon, Florida (USA). Fisher effort and landings mirrored declines in seagrass percent cover, which preceded declines in seagrass aerial coverage resulting from large‐scale, harmful algal blooms. A super‐bloom was posited as the point of ecological collapse of the Indian River Lagoon. We recommend engaging stakeholders and incorporating local ecological knowledge into resource management programs to monitor and improve restoration outcomes by expanding the knowledge base from which decisions are made.

Environmental and social correlates of the plumage color polymorphism in an urban dweller, feral pigeon (Columba livia f. domestica)

We examined how urban environments affect the abundance, proportion, and diversity of plumage color morphs in feral pigeons. Five major plumage color morphs (black, blue, white, red, and mixed) were counted in sixty 25-ha plots in Poznań City (Poland). Generalized additive models were used to study the correlations among abundance, proportion of morphs, and environmental factors. Anthropogenic food sources were positively correlated with the abundance of black morphs and the proportions of black and red morphs. The blue morph abundance peaked at a moderate percentage of tall building cover, but its proportion decreased. A similar decrease was observed in the mixed plumage morphs. The abundance of blue morphs decreased, whereas the abundance of white morphs and the proportion of red morphs increased as the distance from the city center increased. The plumage color morph diversity (Simpson) index was positively correlated with food sources and hedgerow density but negatively correlated with street density. Color morph diversity in the study area may be sustained by differential responses of morphs to the environmental features of the urban environment. However, the positive correlation between the abundance of morphs indicates social attraction rather than social isolation among plumage color morphs.

Diversity and Distribution of Intertidal Cystoseira sensu lato Species Across Protection Zones in a Mediterranean Marine Protected Area.

This study investigates the diversity and distribution of intertidal Cystoseira sensu lato (s.l.) species across different protection zones within the "Capo Gallo-Isola delle Femmine" Marine Protected Area (MPA) in the central Mediterranean Sea. Five Cystoseira s.l. species (Cystoseira compressa, C. foeniculacea, Ericaria amentacea, E. brachycarpa and E. crinita) were observed on the intertidal rocky shores, with varied abundances across the MPA's protection zones. Ericaria amentacea was the only species found in all zones, with a much higher cover percentage in the most protected area (zone A). However, its morpho-functional traits showed an inverse trend, with the largest thalli found in the moderately protected zone B and C. The remaining Cystoseira s.l. species were only found in zones B and C probably due to their wider area and greater habitat diversity compared to zone A. The presence of two non-indigenous species, Asparagopsis taxiformis and Caulerpa cylindracea, was observed exclusively in the less protected zones B and C. Our findings highlight the complex interactions between MPA protection levels and Cystoseira s.l. species conservation, with protection having, in some respects, a positive influence on selected Cystoseira s.l. species, indicating the importance of careful consideration in MPA design and management. Furthermore, this study provides a baseline for future monitoring of Cystoseira s.l. populations in light of ongoing environmental changes in the Mediterranean Sea.

An Inter-Method Comparison of Drones, Side-Scan Sonar, Airplanes, and Satellites Used for Eelgrass (Zostera marina) Mapping and Management

Remote sensing is heavily relied upon where eelgrass maps are needed for tracking trends, project siting and permitting, water quality assessments, and restoration planning. However, there is only a moderate degree of confidence in the accuracy of maps derived from remote sensing, thus risking inadequate resource protection. In this study, semi-synchronous drone, side-scan sonar, airplane, and satellite missions were conducted at five Massachusetts eelgrass meadows to assess each method’s edge-detection capability and mapping accuracy. To ground-truth the remote sensing surveys, SCUBA divers surveyed the meadow along transects perpendicular to shore to locate the last shoot (i.e., meadow’s edge) and sampled quadrat locations along the transect for percent cover, canopy height, and meadow patchiness. In addition, drop frame underwater camera surveys were conducted to assess the accuracy of each remote sensing survey. Eelgrass meadow delineations derived from each remote sensing method were compared to ground-truthing data to address the following study objectives: (1) determine if and how much eelgrass was missed during manual photointerpretation of the imagery from each remote sensing method, (2) assess map accuracy, as well as the effects of eelgrass percent cover, canopy height, and meadow patchiness on method performance, and (3) make management recommendations regarding the use of remote sensing data for eelgrass mapping. Results showed that all remote sensing methods were associated with the underestimation of eelgrass. At the shallow edge, mean edge detection error was lowest for drone imagery (11.2 m) and increased with decreasing image resolution, up to 38.5 m for satellite imagery. At the deep edge, mean edge detection error varied by survey method but ranged from 72 to 106 m. Maximum edge detection errors across all sites and depths for each survey method were 112.4 m, 121.4 m, 121.7 m, and 106.7 m for drone, sonar, airplane, and satellite data, respectively. The overall accuracy of eelgrass delineations across the survey methods ranged from 76–89% and corresponded with image resolution, where drones performed best, followed by sonar, airplanes, and satellites; however, there was a high degree of site variability. Accuracy at the shallow edge was greater than at the deep edge across all survey types except for satellite, where accuracy was the same at both depths. Accuracy was influenced by eelgrass percent cover, canopy height, and meadow patchiness. Low eelgrass density (i.e., 1–10% cover), patchy eelgrass (i.e., shoots or patches spaced &gt; 5 m) and shorter canopy height (i.e., &lt;21 cm) were associated with reduced accuracy across all methods; however, drones performed best across all scenarios. Management recommendations include applying regulatory buffers to eelgrass maps derived from remote sensing in order to protect meadow edge areas from human disturbances, the prioritization of using SCUBA and high-resolution platforms like drones and sonar for eelgrass mapping, and for existing mapping programs to allocate more resources to ground-truthing along meadow edges.

Evaluation of binding activities of a putative lipoprotein LIC_13355 of Leptospira spp.

Pathogenic Leptospira is the etiological cause of the zoonotic life-threatening infection called leptospirosis. The disease is spread worldwide with higher risk in tropical regions. Although leptospirosis represents a burden to the health of humans and animals, the pathogenic mechanisms of Leptospira infection are yet to be clarified. Leptospirosis infection is multifactorial, involving functionally redundant proteins with the capability to invade, disseminate, and escape the host's immune response. In this work, we describe a putative lipoprotein encoded by the gene LIC_13355, genome annotated as hypothetical of unknown function. The coding sequence is conserved among pathogenic Leptospira spp. with high percentage of coverage and identity. The recombinant protein, rLIC_13355, was expressed in Escherichia coli host system in its insoluble form. The circular dichroism spectrum of the refolded protein showed it containing a mixture of secondary structures. rLIC_13355 interacts with extracellular matrix (ECM) component laminin and binds plasminogen (PLG), generating plasmin (PLA), thus possibly participating during the adhesion and dissemination processes. The rLIC_13355 has the ability to interact with Ea.hy926 and HMEC-1 endothelial cells either in monolayer or suspension. The binding of rLIC_13355 with monolayer cells is dose-dependent on protein concentration. Taken together, our data suggest that this is presumably an adhesion lipoprotein that may play diverse roles in host-Leptospira interactions by mediating the interaction with host components and with endothelial cell.

Long-term monitoring of woody plants of Doñana shrublands (SW Spain) from 2008 to 2023.

The long-term monitoring of the plant cover of Doñana shrublands is part of a harmonised protocol for the Long-term Ecological Monitoring Programme of Natural Resources and Processes targeting Terrestrial Vegetation. The general aim of this protocol is to monitor and assess the dynamics and trends of shrubland plant communities in Doñana. For shrublands, percentage cover is recorded annually, starting in 2008, by the Doñana Long-Term Monitoring Team in one field sampling campaign per year during the flowering season (between March and May) across 21 permanent square plots (15 m x 15 m). Permanent plots were located according to stratified random sampling according to the topographic gradient defining the main shrubland species dominance in the Doñana Biological Reserve. Cover is measured using the line intercept method in three transects inside the plots of 15 m length, orientated from west to east and located at fixed points of 2.5, 7.5 and 12.5 metres on both sides of the plot. Using the line-intercept method, the coverage of each species per individual is measured with a measuring tape, recording its class age (adult or seedling) and canopy status (green or dry) as a living or dead specimen. The average plant height is recorded for every transect. This method enables the calculation of the total percentage cover per species and plant density for transects and plots, as well as the total percentage cover per class age and the total percentage cover of dry and green canopies and bare soil. The annual species richness and diversity of woody plants can also be calculated for every plot. This paper presents the latest published version of the standardised dataset of percent cover per woody plant species of Doñana long-term monitoring plots available at GBIF.org.

A Nonparametric Global Win Probability Approach to the Analysis and Sizing of Randomized Controlled Trials With Multiple Endpoints of Different Scales and Missing Data: Beyond O'Brien-Wei-Lachin.

Multiple primary endpoints are commonly used in randomized controlled trials to assess treatment effects. When the endpoints are measured on different scales, the O'Brien rank-sum test or the Wei-Lachin test for stochastic ordering may be used for hypothesis testing. However, the O'Brien-Wei-Lachin (OWL) approach is unable to handle missing data and adjust for baseline measurements. We present a nonparametric approach for data analysis that encompasses the OWL approach as a special case. Our approach is based on quantifying an endpoint-specific treatment effect using the probability that a participant in the treatment group has a better score than (or a win over) a participant in the control group. The average of the endpoint-specific win probabilities (WinPs), termed the global win probability (gWinP), is used to quantify the global treatment effect, with the null hypothesis gWinP = 0.50. Our approach involves converting the data for each endpoint to endpoint-specific win fractions, and modeling the win fractions using multivariate linear mixed models to obtain estimates of the endpoint-specific WinPs and the associated variance-covariance matrix. Focusing on confidence interval estimation for the gWinP, we derive sample size formulas for clinical trial design. Simulation results demonstrate that our approach performed well in terms of bias, interval coverage percentage, and assurance of achieving a pre-specified precision for the gWinP. Illustrative code for implementing the methods using SAS PROC RANK and PROC MIXED is provided.

Urbanization and hydrological dynamics: a 22-year assessment of impervious surface changes and runoff in an urban watershed

The frequency and intensity of flooding have been increasing in urban watersheds. Urbanization disrupts natural landscapes by replacing vegetated areas with impervious surfaces, reducing infiltration and increasing runoff. The objective of this study was to evaluate the relationship between change in impervious surface area and runoff amount of Mihang’o watershed located in the outskirts of Nairobi for the period 2000–2022. The specific objectives of this study were as follows: To determine the change in the impervious surface area of Mihang’o watershed, the trend of precipitation amount in the watershed, and the trend in runoff amount, a major source of flood water from the watershed. Supervised classification was performed on land satellite (Landsat) images to determine percentages of impervious surface cover for the study period, and linear regression analysis was used to establish the trend. Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) rainfall data were retrieved from Google Earth Engine, then processed to produce monthly and annual rainfall totals, and Mann–Kendall trend tests were used to establish the rainfall trend for the watershed. The Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS) model was used to simulate runoff from the watershed with the rainfall data and impervious surface area percentages as inputs; then, linear regression analysis was performed to establish the runoff trend. The impervious surface area increased by 87.03% from 2.88% (0.49 km2) of the total surface area of the watershed in 2000 to 22.21% (3.91 km2) in 2022, demonstrating an approximate increment of 3.96% (0.88 km2) each year. The Mann–Kendall trend test results (Sen’s slope results [β = 0.832], Kendall’s tau results [τb = 0.146], and p-value [0.625]) confirmed that there is no significant change in rainfall amounts. Runoff increased by 84.75% from 0.18 mm in 2000 to 1.18 mm in 2022; otherwise, an approximate increment of 3.85% (0.045 mm) was evident each year. Besides the impervious surface area, the HEC-HMS model factors in the length of slope, length of reach, soil type, size of subbasins, and longest flow path, thus producing accurate runoff estimations.

Impact of agricultural land-use on functional feeding groups of Afrotropical Ephemeroptera, Plecoptera and Trichoptera in the Kat River, Eastern Cape, South Africa

Despite Africa experiencing a substantial rise in inadequately managed agricultural practices, studies examining the effects of these activities on the functional organisation of macroinvertebrates in tropical streams are underdeveloped. The responses of Ephemeroptera, Plecoptera and Trichoptera (EPTs) functional feeding groups (FFGs) to agricultural pollution were investigated in the Kat River, Eastern Cape, South Africa, to identify potential FFG indicators. Physicochemical parameters and macroinvertebrates were sampled from eight sites delineated into four land-use impact categories (highly impacted, HIC; impacted category, IC; moderately impacted, MIC; and least impacted, LIC) based on the percentage of agricultural land cover. The Permutational multivariate analyses of variance (PERMANOVA) results revealed land use (F = 4.2, 3.62; p < 0.05) and season (F = 2.89, p < 0.03) influenced FFGs in the river, with shredder abundances decreasing with increasing agricultural stress. Conversely, collectors, predators and scrapers were tolerant of agricultural disturbance. Nutrient variables (NO3-N, NO2-N and NH4-N), canopy and depth were the critical variables that affected FFG structure in the river. Our findings provided more understanding and insights into the functional structure of EPT in relation to agricultural pollution and can contribute to developing trait-based biomonitoring tools in Africa.

Optimizing aquatic weed management in Lake Ossa, Cameroon: Harnessing the power of biological control and real-time satellite monitoring

Salvinia, Salvinia molesta Mitchell (Salviniaceae) is a free-floating aquatic fern native to Brazil and considered one of the worst weeds in the world. When left unchecked, salvinia forms dense mats on the water surface, limiting sunlight penetration and altering water quality that disrupt ecosystem processes. In 2016, salvinia was first reported in Lake Ossa, Cameroon, and by summer 2021, had expanded to cover almost 49 % of the lake’s 4,000-hectare surface. A multinational team initiated a biological control and monitoring program, importing the salvinia weevil, Cyrtobagous salviniae Calder & Sands (Coleoptera: Curculionidae) from Louisiana, USA, in summer 2021. The objectives of this study were to: quantify the changes in salvinia cover and other floating vegetation, document the establishment and impact of the biological control program, and deliver a tool for near-real time monitoring of floating vegetation. We developed a satellite-based remote sensing application to document in near real-time the changes in coverage of floating vegetation. Using this tool, we quantified the reduction in the salvinia coverage by 80 % within three years of the release of the weevil. Field surveys in 2022 and 2023, demonstrated weevil establishment in the lake and widespread salvinia browning that was associated with weevil damage. Linear regressions of the percent cover of floating vegetation over time, demonstrated that after the weevil release, the rate of change decreased to −1.7 % per 60 days. Field monitoring and satellite imagery showed the establishment of a sedge (Oxycaryum sp., Cyperaceae) within the salvinia mat in late 2021. This secondary invasion slowed the reduction in coverage of floating vegetation from −1.7 % to −0.6 % per 60 days, and warrants further research. By late 2023, the revitalization of Lake Ossa restored fishing and transportation opportunities for the community, and also the comeback the emblematic African manatee. The success of the biological control of salvinia in Lake Ossa is not surprising due to its tropical conditions. However, it highlights the importance of early intervention and continuous monitoring. We propose that the integration of biological control and remote sensing technology is becoming more accessible and can be automated; therefore, a replicable model for future invasive weed programs around the world.

Investigation of Cr2SiC Ceramic MAX Phase Coated Metallic Bipolar Plates in Ex-situ Conditions for Proton Exchange Membrane Fuel Cells

Essential for compact and lightweight proton exchange membrane fuel cell (PEMFC) stacks, metallic bipolar plates (MBPs) suffer from durability and conductivity issues due to surface corrosion and passivation. This study conducts ex-situ characterization of Cr2SiC ceramic MAX phase coatings on stainless steel (SS) 316 L substrates to evaluate their suitability for MBP application. The investigation encompasses coating structure, surface morphology, corrosion resistance, surface wettability, in-plane electrical conductivity, and interfacial contact resistance. X-ray diffraction and X-ray photoelectron spectroscopy confirm the presence of Cr2SiC coatings on SS316L, while energy-dispersive X-ray spectroscopy verifies uniform coverage and elemental weight percentage. Corrosion resistance is evaluated using potentiostatic and potentiodynamic polarization tests, showing excellent resistance with low corrosion current density (Icorr) at both 25 °C (3.29E-03 μA/cm2) and 80 °C (4.32E-02 μA/cm2), meeting US Department of Energy (DOE) technical targets. Potentiodynamic polarization reveals large corrosion potential and small Icorr values at both temperatures, outperforming uncoated samples. Electrochemical impedance spectroscopy post-accelerated corrosion tests show high charge transfer resistance at 25 °C (3.68E+05 Ω cm2) and 80 °C (3.02E+05 Ω cm2), indicating stability in acidic environments. Surface wettability analysis indicates low water affinity with a large contact angle (75°) and low surface free energy (28.92 mJ/m2) for the coated samples as compared to the uncoated samples. Electrical conductivity meets DOE targets with an in-plane conductivity of 4.59E+05 S/m and interfacial contact resistance of 8.04 mΩcm2 after 5-h accelerated corrosion tests at 80 °C. These results suggest that Cr2SiC coated SS316L exhibits excellent corrosion resistance, surface wettability, and electrical characteristics, making them viable for PEMFC applications.

Estimation and Validation of Snowmelt Runoff Using Degree Day Method in Northwestern Himalayas

The rivers of the Himalayas heavily rely on the abundance of snow, which serves as a vital source of water to South Asian countries. However, its impact on the hydrological system of the region is mainly felt during the spring season. The melting of snow and consequent base flow significantly contribute to the incoming streamflow. This article examines the evaluation of the proportionate contribution to the total streamflow of Beas River up to Pandoh Dam through the snow melt. To analyze the snow melt, the snowmelt runoff model (SRM) has been utilized via dividing the study area into seven different elevation zones within a range of 853–6582 m and computing the percentage of snow cover, ranging from 15% to 90% across the basin. To validate the accuracy of the model, several metrics, such as coefficient of determination (R2) and volume difference (VD), are utilized. The R2 reveals that over the span of ten years, the daily discharge simulations exhibited efficiency levels ranging from 0.704 to 0.795, with VD falling within the range of 1.47% to 20.68%. This study has revealed that a significant amount of streamflow originates during the summer and monsoon periods, with snowmelt ranging from 10% to 45%. This research provides crucial understanding of the impact of snowmelt on streamflow, supplying essential knowledge on freshwater supply in the area.