Sensitive Species Research Articles

Detection of Iturin A from Bacillus atrophaeus by HPLC and Mass Spectrometry Analysis and Evaluation of its Antifungal Activity

Background: Bacillus species create several kinds of metabolites, which contain cyclic lipopeptide-type antibiotics, consisting of three major families: fengycin, surfactin, and iturin. Iturin demonstrates powerful biocontrol characteristics and can restrain the growth of a diversity of plant fungal pathogens. Objective: The current study investigates the identification of iturin A from Bacillus atrophaeus using HPLC and Mass spectrometry analysis and evaluate its antifungal effects. Materials and Methods: In this study, the lipopeptide antibiotics were isolated by HPLC and characterized by MS. Then, the lipopeptides were examined for their ability to antagonize the growth of different pathogenic fungi. Antifungal performance of the lipopeptides was determined against Fusarium oxysporum, Aspergillus niger, Penicillium chrysogenum, and Mucor hiemalis according to well diffusion and percentage of growth inhibition. Results: Bacillus atrophaeus HNSQJYH170, isolated from Isfahan soil, offered strong fungicidal activity by producing cyclic lipopeptide-type antibiotics. Inhibition zones were 17.55, 17, 18.50, and 20.99 mm, and the percentages of growth inhibition were 78.54, 62.55, 83.11, and 84/95 for Fusarium oxysporum, Penicillium chrysogenum, Mucor hiemalis and Aspergillus niger, respectively. The spectrum represented the iturins family in retention times of 32.423–33.893 min. MS demonstrated molecular ion peaks (M+H) + for iturin at m/z 1029.55, 1043.60, 1051.55, 1065.60, 1079.60 and 1093.65. The inhibition rate against all fungi on the seventh day of incubation was higher than 80%. Among them, Aspergillus niger was the most sensitive fungal species with an average of 84.95% inhibition. Conclusion: According to the results, Bacillus atrophaeus HNSQJYH170 could operate as a biocontrol agent against a wide spectrum of pathogenic fungi.

Potential drivers and implications of a balanced breeding sex ratio in a small population of an imperiled species with environmental sex determination.

Small populations of imperiled species are susceptible to the negative consequences of skewed sex-ratios. In imperiled species with environmental sex determination such as sea turtles, examining sex ratios across a range of environments and population abundance levels can provide insight into factors that influence population resilience, which can then be the foci of management plans for these species. Breeding sex ratios (the ratio of actively breeding males to females during a reproductive season; BSRs) extrapolated from genetic parentage analyses are a common approach for enumerating sex ratios in sea turtles. Such analyses also allow for the characterization of multiple paternity within sea turtle clutches, which should reflect BSRs and breeding behaviors. We characterized the first BSR for a breeding assemblage of loggerhead sea turtles (Caretta caretta) belonging to the temperate, low-abundance Northern Gulf of Mexico Recovery Unit using genotypes of 16 microsatellite loci from nesting females and hatchlings. Unlike prior studies at both more-tropical and more-temperate, and higher-abundance, Recovery Units in this region, we found a balanced BSR of 1.3:1 males:female and a low incidence (~17%) of multiple paternity. This suggests that there are relatively few males breeding at this assemblage and within this Recovery Unit. Beaches in this region are expected to produce substantial numbers of male hatchlings based on sand temperature data. The relative dearth of mature males may then be due to hydrologic disturbances that disproportionately affect the fitness and survival of male hatchlings, or due to demographic stochasticity. More work is needed to study the factors that might influence male hatchling production and fitness in this region, particularly as climate change is predicted to lead to feminization in global sea turtle populations. Our work demonstrates the broad utility of characterizing BSRs and other sex ratios across a range of populations in imperiled, environmentally sensitive species.

Males miss and females forgo: Auditory masking from vessel noise impairs foraging efficiency and success in killer whales.

Understanding how the environment mediates an organism's ability to meet basic survival requirements is a fundamental goal of ecology. Vessel noise is a global threat to marine ecosystems and is increasing in intensity and spatiotemporal extent due to growth in shipping coupled with physical changes to ocean soundscapes from ocean warming and acidification. Odontocetes rely on biosonar to forage, yet determining the consequences of vessel noise on foraging has been limited by the challenges of observing underwater foraging outcomes and measuring noise levels received by individuals. To address these challenges, we leveraged a unique acoustic and movement dataset from 25 animal-borne biologging tags temporarily attached to individuals from two populations of fish-eating killer whales (Orcinus orca) in highly transited coastal waters to (1) test for the effects of vessel noise on foraging behaviors-searching (slow-click echolocation), pursuit (buzzes), and capture and (2) investigate the mechanism of interference. For every 1 dB increase in maximum noise level, there was a 4% increase in the odds of searching for prey by both sexes, a 58% decrease in the odds of pursuit by females and a 12.5% decrease in the odds of prey capture by both sexes. Moreover, all but one deep (≥75 m) foraging attempt with noise ≥110 dB re 1 μPa (15-45 kHz band; n = 6 dives by n = 4 whales) resulted in failed prey capture. These responses are consistent with an auditory masking mechanism. Our findings demonstrate the effects of vessel noise across multiple phases of odontocete foraging, underscoring the importance of managing anthropogenic inputs into soundscapes to achieve conservation objectives for acoustically sensitive species. While the timescales for recovering depleted prey species may span decades, these findings suggest that complementary actions to reduce ocean noise in the short term offer a critical pathway for recovering odontocete foraging opportunities.

Toxicity of isolated and mixed metals to a native Amazonian ostracod and ecological risk assessment.

In recent decades the Amazonian ecosystem has received large amounts of domestic and industrial effluents, as well as mining-related waste contributing significant quantities of metal to water bodies. Thus, the main objective of the study was to verify the sensitivity of a native Amazonian ostracod (Strandesia rondoniensis) species to isolated and mixed metal salts (CuSO4; ZnCl2; CdCl2 and HgCl2). The sensitivity will be compared to other species using species sensitivity distributions (SSDs) for an ecological risk assessment (ERA). The experiment consisted of simultaneously exposing each metal alone and in mixture, through a factorial design for toxicity with 25 different combinations for 48 h. For the ERA, metal concentrations measured in the water of various aquatic environments in the Amazon basin were considered based on the risk quotient values. The results showed that the metal toxicity gradient was Cd>Hg>Cu>Zn, respectively. The toxicity in the mixture showed that the combination of Cu-Cd and Cu-Zn better fit the model (CA), indicating mainly synergism when copper predominated in the mixture. Meanwhile, the Cu-Hg interaction fit the model better (IA), again indicating synergism when copper was at a higher concentration. The ERA showed a high risk (RQ > 1) for the Cd, Cu, and Hg metals.

Does exposure timing of macrolide antibiotics affect the development of river periphyton? Insights into the structure and function

Discharged sewage is the dominant source of urban river pollution. Macrolide antibiotics have emerged as prominent contaminants, which are frequently detected in sewage and rivers and pose a threat to aquatic microbial community. As a typical primary producer, periphyton is crucial for maintaining the biodiversity and functions of aquatic ecosystem. However, effects of antibiotic exposure time as well as the recovery process of periphyton remain undetermined. In the present study, five exposure scenarios of two typical macrolides, erythromycin (ERY) and roxithromycin (ROX) were investigated at 50 µg/L, dose to evaluate their potential detrimental effects on the structure and function of periphyton and the subsequent recovery process in 14 days. Results revealed that the composition of periphytic community returned to normal over the recovery period, except for a few sensitive species. The antibiotics-caused significant photodamage to photosystem II, leading to continuous inhibition of the photosynthetic capacity of periphyton. Furthermore, no significant difference in carbon metabolism capacity was observed after direct antibiotic exposure, while the amine carbon utilization capacity of periphyton remarkably increased during the recovery process. These results indicated that periphyton community was capable of coping with the periodic exposure of antibiotic pollutants and recovering on its own. However, the ecological functions of periphyton can be permanently disturbed due to macrolide exposure. Overall, this study sheds light on the influence of macrolide exposure on the development, structure and function of the periphytic microbial community in rivers.

Differential responses of community‐level functional traits to mid‐ and late‐season experimental drought in a temperate grassland

Abstract Extreme precipitation events are becoming more intense and frequent due to climate change. This climatic shift is impacting the structure and dynamics of natural communities and the key ecosystem services they provide. Changes in species abundance under these conditions are thought to be mediated by functional traits, morpho‐physiological characteristics of an organism that impact its fitness. Future environmental conditions may, therefore, favour different traits to those in present‐day communities. After 6 years of manipulated precipitation levels, including drought (−50% of ambient precipitation), irrigation (+50% of ambient precipitation), and control (ambient precipitation), we measured five key functional traits (plant height, leaf dry matter content [LDMC], leaf thickness, specific leaf area [SLA], and leaf phosphorus concentration) in 586 individual vascular plants to study the effects of precipitation changes on community‐weighted functional traits. Additionally, we tested whether the precipitation change effects on the traits depend on the time of the growing season. As expected, reduced precipitation impacted community composition only for the late‐season timing, after the seasonal field mowing, but led to a significant change in all community‐level plant traits between season timings. Under drought, communities shifted towards shorter individuals with thicker but small leaves and lower phosphorous content. Overall, a combination of community reassembly and intraspecific variation contributed to community‐weighted differences between control and drought plots for plant height, SLA, and LDMC traits. Species turnover was the main driver of community‐weighted means (CWMs) shifts in all traits in the late‐season but SLA. Whereas all traits showed variations at the community level with drought, SLA and LDMC were the most responsive traits at the species level. Nevertheless, our results suggest underestimation of intraspecific variation due to sensitive species lower abundance under stress. No differences in CWMs of functional traits were observed between control and irrigated plots. Synthesis: Our findings suggest that functional trait composition of grassland communities may shift under climate change‐induced drought, depending on the growing season timings. Trait‐based attempts to predict ecosystem functioning must account for such temporal variation in community trait values.

Derivation of site-specific environmental quality guideline values for fuel-contaminated soils on sub-Antarctic Macquarie Island.

Accidental fuel spills associated with the storage, transfer, and use of diesel fuel for power generation have occurred on sub-Antarctic Macquarie Island since the establishment of the island's research station in 1948. An extensive in situ remediation program was implemented by the Australian government from 2009 to 2016 that used nutrient addition and air sparging to enhance the microbial degradation of petroleum products. During this period, a range of ecotoxicological assessments were conducted to better understand the impacts of fuel in soils on native biota and their sensitivity. This study compiles this ecotoxicological data into a species sensitivity distribution (SSD) to establish environmental quality guideline values (EQGVs) for fuels in soils on Macquarie Island. The SSD model includes 13 critical effect concentrations (CECs) selected using an expert judgment approach. These include data from functional and community-based tests as well as traditional single-species toxicity tests using microbes, plants, and invertebrates and representing the range of carbon content (~3%-48%) and fuel composition at various stages of degradation (from fresh to 18 months aged) in soils as occurs at contaminated sites on the island. A protective concentration (PC80) of 97 mg/kg TPH C9-C40 (95% CI 24-283) was derived for special Antarctic blend diesel from the SSD and is recommended as an appropriate site-specific EQGV and potential remediation target for the immediate station area in the vicinity of infrastructure. More conservative PC values are also provided for areas with higher conservation values outside the station footprint. These EQGVs are the first to be produced for fuels in the sub-Antarctic and Antarctic regions. They will be used to inform ongoing environmental management on Macquarie Island and are likely suitable and recommended for use more broadly across the sub-Antarctic. Integr Environ Assess Manag 2024;00:1-13. © 2024 Commonwealth of Australia. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Subchronic Effects of Tetrachloroethylene on Two Freshwater Copepod Species: Implications for Groundwater Risk Assessment.

Aliphatic chlorinated hydrocarbons, notably tetrachloroethylene (also known as perchloroethylene [PCE]), are persistent, mobile, and toxic (PMT) and/or very persistent, mobile, and toxic (vPMT) groundwater pollutants, often exceeding safe drinking water thresholds. The present study delves into the groundwater risk assessment of PCE with a novel focus on the sensitivity of stygobitic species-organisms uniquely adapted to groundwater environments. Through a comparative analysis of the subchronic effects of PCE on the locomotion behavior of two copepod species, the stygobitic Moraria sp. and the nonstygobitic Bryocamptus zschokkei, we highlighted the inadequacy of the current European predicted-no-effect concentration of PCE for groundwater ecosystems. Our findings indicate significant behavioral impairments in both species at a concentration (32 ng/L PCE) well below the threshold deemed safe, suggesting that the current European guidelines for groundwater risk assessment may not adequately protect the unique biodiversity of groundwater habitats. Importantly, B. zschokkei demonstrated sensitivity to PCE comparable to or greater than that of the target stygobitic species, suggesting its utility as a substitute species in groundwater risk assessment. The present study adds to the limited research on the ecotoxicological sensitivity of groundwater species to PMT/vPMT chemicals and highlights the need for refined groundwater risk-assessment methodologies that consider the susceptibilities of stygobitic species. Environ Toxicol Chem 2024;00:1-13. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Adverse effect of TWPs on soil fungi and the contribution of benzothiazole rubber additives

Tire wear particles (TWPs) pollution is widely present in soil, especially in areas severely affected by traffic. Herein, regular variation of fungal biomass with TWPs was found in soils with different distances from the highway. In addition, the concentrations of benzothiazole compounds (BTHs), an important class of rubber vulcanization accelerators, were found to be positively correlated to the TWPs abundance. Sixty days' soil microcosm experiments were conducted to further confirm the adverse effect of TWPs and BTHs on soil fungi. TWPs spiking at 1000 mg/kg, a detectable level in the roadside, resulted in significant reduction of biomass and significant changes of soil fungal community structure, with Eurotium and Polyporales being the sensitive species. BTH+ 2-hydroxybenzothiazole (OHBT) (the dominant BTHs in soil) spiking at 200 ng/kg, the dose equivalent to 1000 mg/kg TWPs pollution, also caused a similar magnitude of soil fungal biomass reduction. Adonis demonstrated no significant difference of fungal community structure between TWPs and BTH+OHBT spiked soil, suggesting the adverse effect of TWPs on soil fungi may be explained by the act of BTHs. Pure culture using the representative soil fungi Eurotium and Polyporales also confirmed that BTHs were the main contributors to the adverse effect of TWPs on soil fungi.

Exploring Sensitized Photon Upconversion - From Past to Present.

The conversion of low energy photons into high energy photons via triplet-triplet annihilation (TTA) photon upconversion (UC) has become a promising avenue for furthering a wide range of optoelectronic applications. Through the decades of research, many combinations of triplet sensitizer species and annihilator molecules have been investigated unlocking the entire visible spectrum upon proper pairings of sensitizer and annihilator identities. Here, we reflect upon the seminal works which lay the foundation for TTA-UC originating from solution-based methods and highlight the recent advances made within the solid state primarily focusing on perovskite-based triplet generation.

Impact of carbon dioxide concentrations on laboratory sensitivity of Mycoplasma species isolated from dairy cows.

Current Mycoplasma spp. culture protocols lack empirical derivation concerning carbon dioxide (CO2) supplementation and are primarily based on the initial cultivation of Mycoplasma bovis. This study indicates that the suitable range for CO2 supplementation is broader than what is currently recommended by the National Mastitis Council for culturing within the specified 7-10 days. No differences in bacterial growth detection rates were observed among ambient air, 5% CO2, or 10% CO2 supplementation during the 7- and 10-day incubation intervals. These new insights provide evidence supporting the possibility of culturing Mycoplasma spp. under ambient air conditions in a laboratory setting.

Climate risk assessment of the fisheries in Namibia

In Namibia, fisheries are important for food security and protein provisioning, income generation and trade; but they are vulnerable to the impacts of climate change. Not only does climate change impact the marine living resources crucial to fisheries; but changes in weather, currents and storminess are affecting the safety and effectiveness of fishing. Here we ask: What are the key risks from climate change to the eight large-scale fishery sectors of Namibia, and for the recreational and small-scale (artisanal) fisheries? For each fishery sector, we assessed three main risk components: (1) climate hazard exposure; (2) fish species sensitivity; and (3) socio-economic vulnerability. In combination, these three risk components are then used to calculate the overall climate risk for each fishery. Climate hazard exposure was assessed as highest for the small-scale, recreational, and rock lobster fisheries. Species sensitivities were highest for the rock lobster and crab fisheries, followed by monkfish trawlers, hake liners and hake trawlers. Socio-economic vulnerability was highest for the small pelagic fishery (linked to the collapse of pilchard). The overall climate risk emerged as greatest for the rock lobster fishery, followed by the (highly marginalised) small-scale artisanal fishery. The key risks by sector emerging from this assessment, informed five stakeholder workshops held across Namibia in 2023, attended by representatives of each sector and aimed at exploring options for climate adaptation. Based on these, we discuss potential adaptation measures that could reduce risk and minimise consequences, in support of improved climate resilience in Namibian fisheries.

Agrochemical inputs to managed oil palm plantations are a probable risk to ecosystems: Results from a screening level risk assessment

Palm oil is a high value crop widely grown in the tropics. The management of palm oil is characterised by widespread agrochemical use. Here we report the results of a screening level risk assessment conducted from the available literature on the environmental concentration of agrochemicals in surface waters and soils in palm oil growing areas. To date, only a small number of published studies have measured pollutant concentrations in and around palm oil plantations. To identify potential high-risk contaminants, a standard SSD based risk assessment, establishing risk quotients for detected contaminants, was conducted in relation to available species sensitivity distributions. A probabilistic SSD based risk assessment, calculating potential risk distributions, was also conducted for contaminants with the required number of data points available. Metals were the most commonly detected (and measured) substances and also presented the greatest risk, especially copper and zinc, but also nickel, lead and cadmium. For these metals, environmental concentrations overlapped levels found to cause effects in toxicity studies, indicating the potential for adverse outcomes from exposure. To fully understand the extent of this risk, more detailed studies are needed that assess metal speciation states and bioavailability under the prevailing soil and water chemistry conditions in palm oil plots. Limited studies have measured pesticide concentrations in palm oil systems. In these few cases, only a few active substances have been measured. From the limited information available, potential risks are indicated due to the presence of some insecticides. However, fungicides are also widely used for palm oil disease management, but little data studies are available to assess both exposure and potential effects. To further assess the potential chemical footprint of different palm oil management practices, studies are needed that systematically assess pollutant levels across a range of chemical groups to consider effects within a mixture context.

Effect of Climate Change on Wildlife

Climate change is a global catastrophe that disrupts the balance of ecosystem by altering the climatic measures. Human being are not the only living species on earth that is affected by climate change. All the inhabitants on Earth are dependent on suitable living conditions for their survival. All human and non-human species on Earth either directly or indirectly relying on each other. Wildlife is the key indicator of climatic changes in the environment as they are part of various biological and ecological cycles in the atmosphere. Over the century, the atmospheric temperature has increased around 1.1°C. Changes in climatic conditions is affecting the terrestrial and aquatic biomes in plenty of ways. Limiting basic living conditions of animals by destruction of their natural habitation and its transformation into urban lands which intensifies the human-wildlife interactions. Migration of temperature sensitive species to the areas of higher altitude. High temperatures have increased the occurrence of wild-land fires, floods and droughts five times more than past 50 years. Animals naturally respond to altering climatic conditions by exhibiting changes in their general and reproductive behavior, growth patterns, increased zoonotic diseases. All these above cited effect put them to the status of endangered species and ultimately to the extinction. Strategic approaches i.e., protection, management, planning and evaluation of natural biomes to conserve the Earth’s biodiversity must be opted to avoid the extinction of wild species.

Chronic contamination in the southern Gulf of Mexico coastal zone, as evidenced by meiofauna biological traits

Meiofauna is a good pollution indicator that reflects the ecological status of sediments and their linkages with overlying communities. However, long-term monitoring of this fauna is a developing research activity in most marine ecosystems. This study assessed seasonal spatial and temporal changes in meiofauna composition, abundance, and biological traits in the southern Gulf of Mexico sublittoral zone. We examined two questions: How do the meiofauna attributes vary spatially and seasonally? Which contaminants correlate with the distribution of meiofauna biological traits? We analysed sediment characteristics, metals, hydrocarbons, and meiofauna data collected at shallow coastal sites (<10 m) during eight annual surveys (2005–2020). Organic contamination increased when natural disturbances occurred, mainly in the dry season, decreasing the number of nematode taxa and increasing their abundance. During the eight yearly sampling events, nematodes, harpacticoid copepods, and polychaetes varied according to the sedimentary gradient. Chronic contamination (aromatic compounds, Cr, V, Cd, Cr) covaried with meiofauna biological traits. Our results point out meiofauna taxa (e.g., Anoplostoma, Halalaimus, Monhystera, harpacticoid copepods, saccocirrid polychaetes) as bioindicators of resilient and disturbed sites for terrigenous and transitional sediments, while in carbonate sediments dominated sensitive species. Resilient sites were exposed to the Grijalva-Usumacinta river discharges and the oil industry. Tolerant and opportunistic taxa such as the nematodes Anoplostoma and Xyala were classified as colonisers and non-selective deposit feeders. Conversely, sensitive taxa such as Halalaimus and harpacticoid copepods were semelparous, carnivorous, and persisters.

Determining high priority disinfection byproducts based on experimental aquatic toxicity data and predictive models: Virtual screening and in vivo study

Only about 100 disinfection byproducts (DBPs) have been tested for their potential aquatic toxicity. It is not known which specific DBPs, DBP main groups, and DBP subgroups are more toxic due to the lack of experimental toxicity data. Herein, high priority specific DBPs, DBP main groups, DBP subgroups, most sensitive model aquatic species, potential PBT and PMT (persistent, bioaccumulative/mobile, and toxic) DBPs were virtually screened for 1187 updated DBPs inventory. Priority setting based on experimental and predicted acute and chronic aquatic toxicity data found that the aromatic and alicyclic DBPs in four DBPs main groups showed high priority because larger proportions of aromatic and alicyclic DBPs are in high hazard categories (i.e. Acute and/or Chronic Toxic-1 or Toxic-2) according to the criteria in GHS system compared to the aliphatic and heterocyclic DBPs. The halophenols, estrogen-DBPs, nonhalogenated esters, and nonhalogenated aldehydes were recognized as high priority DBPs subgroups. For specific DBPs, 19 and 31 DBPs should be highly concerned in the future study because both acute and chronic toxicity of those DBPs to all of the three aquatic life (algae, Daphnia magna, fish) were classified as Toxic-1 and Toxic-2, respectively. The Daphnia magna and algae were sensitive to the acute toxicity of DBPs, while the fish and Daphnia magna were sensitive to the chronic toxicity of DBPs. One potential PBT (Tetrachlorobisphenol A) and four potential PMT DBPs were identified. For verification, the acute toxicity of four DBPs on three aquatic organism were performed, and their tested acute toxicity data to three aquatic organisms were consistent with the predictions. Our results could be beneficial to government regulators to adopt effective measures to limit the discharge of high priority DBPs and help the scientific community to develop or improve disinfection processes to reduce the production of high priority DBPs.

Influence of polystyrene nanoplastics on the toxicity of haloperidol to amphibians: An in vivo and in vitro approach

Chemical pollution is a major driver for the current worldwide crisis of amphibian decline. The present study aimed to assess the influence of polystyrene nanoplastics (PS-NPLs) on the toxicity of haloperidol to aquatic life stages of amphibians, by using in vivo (tadpoles of Xenopus laevis and Pelophylax perezi) and in vitro (A6 and XTC-2 cell lines of X. laevis) biological models. Tadpoles of both species were exposed, for 96 h, to haloperidol: 0.404 to 2.05 mg l−1 (X. laevis) or 0.404 to 3.07 mg L−1 (P. perezi). The most sensitive species to haloperidol (X. laevis) was exposed to haloperidol's LC50,96h combined with two PS-NPLs concentrations (0.01 mg L−1 or 10 mg L−1); the following endpoints were monitored: mortality, malformations, body lengths and weight. In vitro cytotoxicity was assessed by exposing the two cell lines, for 72 h, to: haloperidol (0.195 to 100 mg L−1) alone and combined with 0.01 mg L−1 or 10 mg L−1 of PS-NPLs. Xenopus laevis tadpoles revealed a higher lethal and sublethal sensitivity to haloperidol than those of P. perezi, with LC50,96h of 1.45 and 2.20 mg L−1. In vitro assays revealed that A6 cell line is more sensitive haloperidol than XTC-2: LC50,72h of 13.2 mg L−1 and 5.92 mg L−1, respectively. Results also suggested a higher sensitivity of in vivo models when compared to in vitro biological. Overall, PS-NPLs did not influence haloperidol's toxicity for in vivo and in vitro biological models, except for a reduction on the incidence of malformations while increasing the lethal toxicity (at the lowest concentration) in tadpoles. These opposite interaction patterns highlight the need for a deeper comprehension of NPLs and pharmaceuticals interactions. Results suggest a low risk of haloperidol for anuran tadpoles, though in the presence of PS-NPLs the risk may be increased.

Validation of real-time PCR assays for detecting Plasmodium and Babesia DNA species in blood samples

Malaria and babesiosis are global health threats affecting humans, wildlife, and domestic animals, particularly in Africa, the Americas, and Europe. Malaria can lead to severe outcomes, while babesiosis usually resembles a mild illness but can be severe and fatal in individuals with weakened immune systems. Swift, accurate detection of these parasites is crucial for treatment and control. We evaluated a real-time PCR assay for diagnosing five Plasmodium and three Babesia species from blood samples, assessing its sensitivity, specificity, and analytical performance by analyzing 46 malaria-positive and 32 Babesia spp-positive samples diagnosed through microscopy. The limit of detection for Plasmodium species ranged from 30 to 0.0003 copies/µL. For mixed infections, it was 0.3 copies/µL for P. falciparum/P. vivax and 3 copies/µL for P. malariae/P. knowlesi. Babesia species had a detection limit of 0.2 copies/µL. No cross-reactivity was observed among 64 DNA samples from various microorganisms. The assay showed good sensitivity, detecting Plasmodium and Babesia species with 100 % accuracy overall, except for P. falciparum (97.7 %) and B. microti (12.5 %). The low sensitivity of detecting B. microti was attributed to limitations in microscopy for species identification. This technique heavily relies on the proficiency of the examiner, as species within the genus cannot be distinguished under a microscope. Additionally, Babesia can be confused with the early trophozoite stage (ring forms) of Plasmodium parasites. The findings support multiplex qPCR's diagnostic superiority over the gold standard, despite higher costs. It offers enhanced sensitivity, specificity, and detects mixed infections, crucial for effective monitoring and diagnosis of malaria and babesiosis in endemic regions with significant public health challenges.

Microplastic Characteristics and Risk Assessment in Multigate Dam-type River

Microplastics pose a serious ecological threat to rivers in China, and the construction of a large number of dams has complicated this problem. Ten dams of the Shaying River were chosen to investigate the abundance and composition of microplastics in surface water and sediments of the reservoir and upstream river. Ecological risk was evaluated using species sensitive distribution （SSD） and pollution load index （PLI）. The results showed that the Shaying River was exposed to a severe risk of microplastics from upstream to downstream. The construction of dams did not significantly affect the distribution of microplastics in the river. River sediments became a sink for microplastics in the surface water； however, the ecological risk posed by microplastics in the surface water was greater, and the comparison of the two assessment methods showed that the species sensitivity distribution assessment better reflected the accumulation and feeding behavior of organisms to pollutants compared to the pollution load index.

Derivation of ecotoxicologically acceptable Cu concentrations in soil from different land uses in South Korea

This study aimed to establish ecotoxicologically acceptable Cu concentrations for soil-residing species by integrating the biotic ligand model and the species sensitivity distribution. Statistical analyses were performed on 35 soil solution samples collected from four distinct land use sites: residential, agricultural, forested, and industrial regions. The environmental parameters of these samples, including pH, dissolved organic carbon (DOC), Ca2⁺, Mg2⁺, K⁺, and Na⁺ concentrations, exhibited wide variations across the four regions. Specifically, pH and the concentrations of Mg2⁺, K⁺, and Na⁺ showed significant variability. Additionally, a strong correlation was observed between pH and Ca2⁺, as well as between the DOC concentration and Mg2⁺ and Na⁺. Using the biotic ligand model, we derived the half-maximal effective activities of Cu (EC50{Cu2+}) for 10 soil organisms based on the chemical compositions of the soil solution samples. Additionally, a species sensitivity distribution approach was employed to determine the 5% hazardous concentration (HC5) for soil biota, which was closely associated with DOC and Na⁺ concentrations, with Mg2⁺ playing a secondary role. We attributed these relationships to the formation of DOC complexes that mitigate Cu toxicity, along with competitive interactions with cations. Notably, HC5 values did not differ significantly across sampling sites (p = 0.523). Clustering based on environmental factors grouped the samples into four clusters, each containing soils from different land use types. However, the third cluster included an outlier from agricultural soil due to its unusually high pH and DOC levels. These findings suggest that it is crucial to consider site-specific soil characteristics when determining ecotoxicologically acceptable Cu concentrations, and soil solution characteristics do not always align with specific land use patterns.