Population Growth Inhibition Research Articles

Abstract 5304: ABL407, a LILRB4x4-1BB bispecific antibody with a wild type Fc, exhibits potent antitumor activity by modulating immune system in multiple ways involving T cells, myeloids, and regulatory T cells

Abstract Tumor-associated myeloid cells such as myeloid-derived suppressor cells (MDSC) accumulate in the tumor microenvironment (TME) and suppress anti-tumor immune responses in a broad range of cancers. LILRB4 (Leukocyte Immunoglobulin-Like Receptor Subfamily B Member 4), an emerging myeloid target, is specifically expressed in tumor-associated myeloid cells and suppresses the immune response, thus promoting cancer progression and metastasis. ABL407 is a First-in-Class bispecific antibody designed to simultaneously target LILRB4 and 4-1BB, enabling LILRB4 expression-dependent 4-1BB activation. By antagonizing LILRB4 signaling, ABL407 inhibited LILRB4 mediated immunosuppression, restoring T cell activity. In addition, ABL407 inhibited fibronectin, a potential LILRB4 ligand, -mediated suppression of myeloid cells. To evaluate the efficacy of ABL407, we established EL4 murine tumor model overexpressing LILRB4 (EL4/LILRB4) in h4-1BB transgenic mice and hLILRB1/4-h4-1BB triple transgenic mice. We observed LILRB4 was overexpressed in M-MDSC in the blood and liver-metastasized tumors. A significant decrease of M-MDSC population and tumor growth inhibition was observed in mice treated with anti-LILRB4 antibody and ABL407. ABL407 treatment resulted in a proportion increment of T cells. However, the percentage of Treg cells and M-MDSC in the liver and blood was reduced by ABL407 treatment in hLILRB1/4-h4-1BB triple transgenic mice. Mice with complete remission (CR) were further protected from the rechallenge of previously exposed tumor after 3 months of cessation of ABL407 treatment, implicating that immunological memory might be generated. In conclusion, our findings suggest that ABL407, LILRB4x4-1BB bispecific antibody, may be a promising strategy for the treatment of cancer. It can be applied as a "LILRB4 antagonist" as well as a "LILRB4-dependent 4-1BB agonist" across a broad spectrum of cancers. Citation Format: Minkyu Seon, Yangsoon Lee, Hyunseong Youn, Yelim Park, Sora Kim, Kyungjin Park, Jonghwa Won. ABL407, a LILRB4x4-1BB bispecific antibody with a wild type Fc, exhibits potent antitumor activity by modulating immune system in multiple ways involving T cells, myeloids, and regulatory T cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5304.

How antibiotic exposure affect predator-prey interactions by population dynamics in ciliates?

Biodiversity loss resulting from environmental pollution is a global concern. While interspecific interactions are central to ecology, the impact of environmental pollution on predator-prey interactions and its ecological consequences, such as extinction and biodiversity loss, remain unclear. To investigate the effects of antibiotic exposure on predation strength and the resulting ecological consequence, the Didinium-Paramecium was utilized as a predator-prey model and exposed to nitrofurazone or erythromycin, two common pollutants, respectively. Initially, we determined prey population growth dynamics, body size, and predator numerical-functional responses. Subsequently, these above parameters were integrated into a mathematical model of predator-prey predation. Then both the long time-series data and phase portraits obtained through model simulation were used to estimate interaction strength and to predict the outcome of predator-prey coexistence. Our results revealed that exposure to either antibiotic significantly reduced prey population growth parameters (e.g., μmax and K) while increasing individual body size. The combined effects of antibiotic exposure and predation pressure on population growth inhibition or body size promotion were variable, mostly additive, with a few cases of synergy and extremely rare antagonism, depending on antibiotic exposure concentration. As antibiotic exposure concentration increased, the predator rmax generally declined, while functional responses varied depending on specific parameters, implying a decrease in predator-prey interaction strength. Analyses of phase portrait features showed that the population oscillation amplitude decreased with increasing antibiotic exposure concentrations, the cycle length of adjacent peaks increased, and prey extinction occurred earlier. In conclusion, antibiotic exposure reduced both predator and prey fitness, underlying the reason antibiotics reduces the strength of predator-prey interaction. Despite the indirect benefits of prey gain from this, the presence of predators can expedite the process of prey extinction caused by antibiotic exposure.

Activity of nanoemulsion botanical insecticides from Myristica fragrans and Jatropha curcas essential oil against Sitophilus zeamais

Abstract. Nuryanti NSP, Budiarti L, Dulbari, Sutrisno H, Sudrajat D, Yuriansyah, Priyadi, Rahmadi R, Rochman F, Sari EY, Maharani JS. 2023. Activity of nanoemulsion botanical insecticides from Myristica fragrans and Jatropha curcas essential oil against Sitophilus zeamais. Biodiversitas 24: 5610-5617. Maize weevils also known as Sitophilus zeamais, are primary pests that decrease in the quality and quantity of grain products. This study aimed to examine the impact of nanoemulsion formulas of Myristica fragrans and Jatropha curcas essential oils on S. zeamais adults. The investigation focused on the toxicity, ability to inhibit population growth, intensity of damage caused, and effect on seed weight loss. The essential oils were extracted using the distillation method, and the toxicity was tested through contact, fumigant, and seed dressing. A probit program was used to analyze the toxicity level (LC50 and LC95). The results showed that M. fragrans essential oil had the highest toxicity in contact treatment and the lowest when applied via fumigation. Furthermore, this method shows an LC50 value for the contact method of 0.53% and fumigation of 1.01%, while the LC95 value is 4.38% and 10.60% respectively. Based on the LC95 botanical insecticide from J. curcas, all three methods were toxic to S. zeamais adults, with contact being the highest, followed by seed dressing, and fumigant, at 5.23, 6.44, and 19.94%, respectively. The botanical insecticides derived from M. fragrans essential oil through contact provided the best inhibitory activity on population development, intensity of damage, and seed weight loss, with values of 18.00, 16.81, and 13.96%. Plant-based pesticides not only cause pest mortality but also maintain seed quality by reducing weight loss, intensity of pest attacks, and inhibiting the development of pest populations in storage.

Akanthomyces dipterigenus acts as a potential biocontrol agent by causing mortality and inhibiting population growth of Bemisia tabaci

Bemisia tabaci is a worldwide pest, and has developed severe resistance to many insecticide. Therefore, it is great significance to find new substitute for chemical insecticide to control B. tabaci. In this study, selected efficient strains by comparing the virulence of Akanthomyces dipterigenus, Cordyceps javanica, Purpureocillium lilacinum, Penicillium camemberti, Metarhizium anisopliae, and Beauveria bassiana against 2nd-instar nymphs of B. tabaci and bioassays were conducted on various developmental stages of B. tabaci using highly pathogenic strain. Additionally, the effects of medium lethal concentration of high-efficiency strains on the biological parameters of B. tabaci were also studied. The bioassay showed that six entomopathogenic fungi have significant effects on the 2nd-instar nymphs of B. tabaci, the median lethal concentration (LC50) of A. dipterigenus against 2nd-instar nymphs of B. tabaci was only 6.54 × 103 (3.35 × 103–1.13 × 104) conidia mL−1, which was lower than that of the other five fungi, and the median lethal time (LT50) was the shortest. In addition, A. dipterigenus also had lethal effects on eggs, nymphs and adults of B. tabaci, among which the mortality rate of 2nd-instar nymphs was the highest. The fungal treatment affected the population parameters of B. tabaci, R0, r, and λ were significantly reduced, T was significantly prolonged, and had higher preadult mortality and shorter adult longevity, but had no significant effect on the total fecundity. These findings highlight the potential of using A. dipterigenus as a sustainable and eco-friendly alternative to chemical insecticides for controlling B. tabaci populations in agricultural settings.

Physiological response and molecular mechanisms against UV-B radiation in Brachionus asplanchnoidis (Rotifera)

Ultraviolet B (UV-B, 280–320 nm) radiation is a major environmental stressor for aquatic organisms on Earth's surface. Its effects on biological systems are well known, but the mechanisms by which organisms respond and adapt to UV-B radiation are still being explored. In this study, we investigated the effects of UV-B radiation on the monogonont rotifer Brachionus asplanchnoidis, focusing on physiological parameters, antioxidant systems, DNA damage, and DNA repair-related molecular mechanism. Our results showed that the LD50 was at 28.53 kJ/m2, indicating strong tolerance to UV-B. However, UV-B radiation caused adverse effects on growth and reproduction, with shortened reproductive period and longevity, decreased fecundity and hatchability, and inhibition of population growth. Biochemical analyses revealed severe oxidative damage and lipid peroxidation, with increased ROS and MDA levels. Activities of antioxidant enzymes were highly induced at low doses but decreased at high doses. DNA damage also occurred in UV-B-exposed rotifers. Furthermore, selected DNA repair-related genes were up-regulated in a dose-dependent manner. These findings provide a comprehensive understanding of the effects of UV-B radiation on rotifers and highlight the importance of considering both ecological and molecular responses in assessing the impact of UV-B radiation on aquatic organisms.

Prediction of the toxic impact on the freshwater microalgae Scenedesmus intermedius produced by the interaction of copper sulfate and copper oxychloride in a binary mixture with glyphosate

The high population growth worldwide causes a high demand for food with an increase in the use of different agrochemicals, with pesticides and herbicides being the primary pollutants of anthropogenic origin in the environment. One of the critical aims of ecotoxicology is the evaluation of toxic effects of mixtures of chemical substances that can have additive, synergistics or antagonistics effects in different ecosystems. For this reason, the aims of this research were to: 1) estimate the individual subchronic toxicity of agrochemicals copper oxychloride [Cu2(OH)3Cl], copper sulfate (CuSO4), and glyphosate (Gly-BH) on the inhibition of population growth of the freshwater chlorophyte Scenedesmus intermedius, and 2) predict the antagonistic, synergistic, or additive behaviour of binary mixtures of Gly-BH with Cu2(OH)3Cl and CuSO4 through the Combination Index Equation (CIE). The individual toxicity order at 7 days of exposure in S. intermedius was CuSO4 (IC50 2.70 mg/l) > Gly-BH (IC50 4.03 mg/l) with no statistical differences between both agrochemicals and > Cu2(OH)3Cl (IC50 25.59 mg/l) with a major tolerance if it compared with the other chemicals. For the binary mixture of CuSO4/Gly-BH, an antagonistic effect was observed (combination index CI > 1), but with lower toxicity (IC50 7.40 mg/l) when compared with the individual responses of these compounds. However, in the mixture, Cu2(OH)3Cl/Gly-BH was more toxic with a synergistic response (IC50 0.85 mg/l) even between 5 and 30 times higher. These results highlight the importance of studying interactions of chemical substances in ecosystems to establish a better evaluation and regulation of their environmental impact.

UV-B radiation alleviated detrimental effects of polymethyl methacrylate microplastics on marine diatom Thalassiosira pseudonana

Microplastics (MPs) in marine environments simultaneously affect microalgae with UV-B radiation, while their joint effecting mechanisms remain largely unknown. To fill this research gap, the joint effects of polymethyl methacrylate (PMMA) MPs and UV-B radiation (natural environments intensity) on the model marine diatom Thalassiosira pseudonana were investigated. Antagonism was found between the two factors with regards to population growth. Furthermore, we found more inhibited population growth and photosynthetic parameters when pre-treated with PMMA MPs compared to pre-treated with UV-B radiation before joint-treated by the two factors. Transcriptional analysis elucidated that UV-B radiation could alleviate the down-regulation of photosynthetic (PSII, cyt b6/f complex and photosynthetic electron transport) and chlorophyll biosynthesis genes caused by PMMA MPs. Besides, the genes encoding carbon fixation and metabolisms was up-regulated under UV-B radiation, which could provide extra energy for the enhanced anti-oxidative activities and DNA replication-repair processes. These consequences showed that the toxicity of PMMA MPs was comprehensively alleviated when T. pseudonana was jointed treated by UV-B radiation. Our results reveled the underlying molecular mechanisms of antagonistic effects between PMMA MPs and UV-B radiation. This study provides important information that environmental factors like UV-B radiation should be considered when accessing the ecological risks of MPs on marine organisms.

Alien species affect the abundance and richness of native species in tropical forests: The role of adaptive strategies

AbstractUnderstanding the role of alien species in forest communities, and how native and alien species interact to shape the composition and structure of contemporary forests, is of critical importance to invasion ecology and natural resource management. We used vegetation data collected over a 20‐year period in 341 permanent plots representing remnants of closed‐canopy forests and post‐agricultural secondary forests across Puerto Rico to compare changes in the composition and abundance of native and alien woody species in plots with and without aliens across different forest types and to assess whether aliens and natives show divergence or convergence regarding functional roles and ecological strategies. We also tested the applicability of Grime's CSR (competitive, stress‐tolerant, and ruderal strategies) theory to explain naturalization success. Species richness and abundance of natives are consistently lower in plots in which aliens are present compared with those without them. This negative association between aliens and natives has been consistent over the 20 years and across all forest types. Both native and total richness slightly increased over the 20 years, but the increase in native species richness was three times lower in plots with aliens relative to those without aliens. The CSR classification provided insight into the naturalization success of aliens. Corroborating the “join the locals” hypothesis, aliens use the same functional spaces as natives. The exception is in dry forests, where aliens and natives differ in the use of functional spaces, a result that corroborates the “try harder” hypothesis. Generally, aliens were better competitors compared with natives, and natives were more stress‐tolerant than aliens. Our combined results suggest that alien species may inhibit population growth or even drive local changes in native plant communities by transforming the assembly and dynamics of tropical forests. Ultimately, modifications linked to invasive species may have significant implications for local forests, affecting their regeneration and productivity. More definitive conclusions require additional plot censuses, and analyses of disturbance regimes and stand‐age structure to reveal the long‐term implications of alien species on regenerating tropical forests, including their vulnerability, resilience, and adaptive capacity to cope with various aspects of climate change.

Spatiotemporal Evolution and Influencing Factors of Population Growth Transition in China during the COVID-19 Pandemic

At present, China has lost its demographic dividend. Meanwhile, in the face of the twin challenges of rising living costs and the uneven distribution of educational resources, the fertility intentions of ordinary people are rapidly declining. In the background, China’s latest birth incentive policy has not had the desired effect. Especially with the COVID-19 pandemic, these issues have become more complicated, making it more difficult to achieve policy goals. Analysis of changing characteristics and influencing mechanisms in China’s current stage of population growth is therefore significant. Such analysis can help improve China’s population structure and preserve the advantage of human resource endowment. In this paper, we use data from 2008, 2012, 2016, and 2020 as made available from the resources of China’s National Bureau of Statistics and National Health Commission. These included annual macro statistics, seventh census data, and COVID-19 pandemic data, allowing us to analyze the influencing mechanism of China’s population growth by using the Geographic Detector Model. The research revealed the dependency ratio as the primary factor influencing spatial differentiation of population growth in China, indicating that the dependency burden plays a role in inhibiting population growth. The secondary factor showed different changes in stages. At the same time, any two factors showed more substantial explanatory power after the interaction, meaning the spatial distribution of China’s population growth results from the joint influence of many factors. The strong interaction was mainly concentrated around the dependency ratio and were with women’s political participation and internet coverage. However, under the impact of the COVID-19 pandemic, the explanatory power of traditional factors was diluted, leading to a decline in the strength of interaction.

The Role of a Child Tax Policy: Population, Human Capital, and Economic Growth

This study analyzes the impact of a child tax policy on the population, human capital, and economic growth in an overlapping generations model with endogenous fertility and human capital. The model shows that the child tax policy inhibits population growth and promotes human capital accumulation, generating a trade-off between the quantity and quality of children. The reduced population and increased human capital both contribute to per capita income. The balance between the negative impact of the child tax policy on the population and the positive impact on per capita income ultimately determines the impact on aggregate growth. The results show that the effect on aggregate growth rate is positive when parents' preference for children is large enough, and negative otherwise. In addition, with the pay-as-you-go pension system, I find that, under feasible conditions, the effect of the child tax policy on pensions is the same as that on total growth.

ROS-mediated time-varying cytotoxic effects on Phaeodactylum tricornutum under the stress of commercial naphthenic acids

The aquatic toxicity and ecological risks of naphthenic acids (NAs) in marine environments have attracted an increasing amount of attention. However, there remains a lack of methodologies for the long-term risk assessment of NAs on marine ecosystems after high acid crude oil spill accidents. In this study, using the model microalgae Phaeodactylum tricornutum as the target object, the time-effect manner under NAs stress is investigated for a continuous 24–144 h. We found that: 1) NAs caused photosynthetic damage and persistent oxidative stress that slowed the growth rate and limited the maximum growth of P. tricornutum population within 24 h to 144 h of exposure, especially under the high concentration treatment; 2) Within 144 h, NAs can cause oxidative stress to P. tricornutum. The damage to cell membrane and radical oxidative species (ROS) accumulation of P. tricornutum were observed as obvious time-effect; 3) Under NAs stress, the two types of cell death (accidental cell death and regulated cell death) of P. tricornutum cell mediated by ROS played different roles in the population growth inhibition of P. tricornutum. Moreover, regulated cell death of the P. tricornutum cell was accompanied by PS externalization, DNA fragment and the G2/M phase stagnation acted as an adaptive regulatory mechanism under NAs stress. This explained the dose-time-effects of NAs on the population growth of P. tricornutum. Overall, the results suggested that NAs have a lasting effect on marine phytoplankton populations, and long-term risk assessments are required after high acid crude oil spill accidents. This is the first attempt to identify the different types of death at the cellular level to explain the time-effect toxicity at the population level of marine microalgae when exposed to NAs. This research will provide a new approach to facilitate further risk assessments for NAs and related contaminants in marine ecosystems.

Particles Morphology Impact on Cytotoxicity, Hemolytic Activity and Sorption Properties of Porous Aluminosilicates of Kaolinite Group

A comparative study of the properties of aluminosilicates of the kaolinite (Al2Si2O5(OH)4∙nH2O) group with different particles morphology has been carried out. Under conditions of directed hydrothermal synthesis, kaolinite nanoparticles with spherical, sponge, and platy morphologies were obtained. Raw nanotubular halloysite was used as particles with tubular morphology. The samples were studied by X-ray diffraction, SEM, solid-state NMR, low-temperature nitrogen adsorption, and the dependence of the zeta potential of the samples on the pH of the medium was defined. The sorption capacity with respect to cationic dye methylene blue in aqueous solutions was studied. It was found that sorption capacity depends on particles morphology and decreases in the series spheres-sponges-tubes-plates. The Langmuir, Freundlich, and Temkin models describe experimental methylene blue adsorption isotherms on aluminosilicates of the kaolinite subgroup with different particles morphology. To process the kinetic data, pseudo-first order and pseudo-second order were used. For the first time, studies of the dependence of hemolytic activity and cytotoxicity of aluminosilicate nanoparticles on their morphology were carried out. It was found that aluminosilicate nanosponges and spherical particles are not toxic to human erythrocytes and do not cause their destruction at sample concentrations from 0.1 to 1 mg/g. Based on the results of the MTT test, the concentration value that causes 50% inhibition of cell population growth (IC50, mg/mL) was calculated. For nanotubes, this value turned out to be the smallest—0.33 mg/mL. For samples with platy, spherical and nanosponge morphology, the IC50 values were 1.55, 2.68, and 4.69 mg/mL, respectively.

Toxicity of 2, 2′, 4, 4′-tetrabromodiphenyl ether (BDE-47) on the green microalgae Chlorella sp. and the role of cellular oxidative stress

Polybrominated diphenyl ethers (PBDEs) are toxic to marine organisms including the major primary producer phytoplankton, while the toxic mechanisms haven't yet been fully clarified. Therefore, we comprehensively studied the toxic mechanisms of BDE-47 on the marine chlorophyte Chlorella sp., with a focus on the role of cellular oxidative stress. The results indicate that BDE-47 stress resulted in the inhibition of population growth as well as cell death and programmed cell death. The antioxidant system was activated in both low and high BDE-47 treatments, but only microalgal cells in the high BDE-47 treatment showed cellular oxidative stress. By adding ROS inhibitor, the relief of photosynthetic inhibition, Ca2+ overproduction and cell death was found. Therefore, we conclude that photosynthetic damage, cell death and cellular oxidative stress were the major mechanisms of BDE-47 toxicity to Chlorella sp., and that cellular oxidative stress played an important role in mediating the other mechanisms.

Alleviation of Tris(2-chloroethyl) Phosphate Toxicity on the Marine Rotifer Brachionus plicatilis by Polystyrene Microplastics: Features and Molecular Evidence.

As emerging pollutants, microplastics (MPs) and organophosphorus esters (OPEs) coexist in the aquatic environment, posing a potential threat to organisms. Although toxicological studies have been conducted individually, the effects of combined exposure are unknown since MPs can interact with OPEs acting as carriers. In this study, we assessed the response of marine rotifer, Brachionus plicatilis, to co-exposure to polystyrene MPs and tris(2-chloroethyl) phosphate (TCEP) at different concentrations, including population growth, oxidative status, and transcriptomics. Results indicated that 0.1 μm and 1 μm MPs were accumulated in the digestive system, and, even at up to 2000 μg/L, they did not exert obvious damage to the stomach morphology, survival, and reproduction of B. plicatilis. The presence of 1 μm MPs reversed the low population growth rate and high oxidative stress induced by TCEP to the normal level. Some genes involved in metabolic detoxification and stress response were upregulated, such as ABC and Hsp. Subsequent validation showed that P-glycoprotein efflux ability was activated by combined exposure, indicating its important role in the reversal of population growth inhibition. Such results challenge the common perception that MPs aggravate the toxicity of coexisting pollutants and elucidate the molecular mechanism of the limited toxic effects induced by MPs and TCEP.

Baicalein inhibits cell proliferation and enhances apoptosis in human A549 cells and benzo(a)pyrene‐induced pulmonary carcinogenesis in mice

Our current study is done to explore the possible mechanisms to elaborate on the growth inhibitory effect of baicalein (BE) in human lung carcinoma. Initially, BE (25 and 50 µM) treatment for 24 h, suppressedthe viability and inhibited population growth in A549 cells. BE upholds the production of reactive oxygen species (ROS) with concomitant replenishment of glutathione, catalase, and glutathione peroxidase activity. The expression level of nuclear factor erythroid 2-related factor 2and heme oxygenase-1markedly increased after BE treatment will intimidate A549 cells proliferation by the ROS-independent pathway via the antioxidant pathway. In vivo investigations were carried out on BE (12 mg/kg, oral) in benzo(a)pyrene (B(a)P; 50 mg/kg, oral) induced lung carcinogenesis in mice. BE induces caspase-dependent apoptosis by increasing the levels of cytosolic cytochrome c accompanied by upregulating the outflow of p53, Bax, and caspase-3 with a concomitant abatement in the outflow of Bcl-2 in both in vitro and in vivo. In the murine model, BE treatment hindered the countenance of proliferation-related proteins (argyrophilic nucleolar organizing regions and proliferating cell nuclear antigen). Additionally, appraisal of the cell nucleus by transmission electron microscopic assessment uncovered that BE treatment adequately counteracts B(a)P-induced lung cancer cell survival. During the transition of the G0 /G1 phase, BE is arrested in the cell cycle process. This might be the cause of a substantial increase in the appearance of p21Cip1 with concomitant downregulating the expressions of CDK4, cyclin D, and cyclin E both in vitro and in vivo. Our results conclude that BE treatment induced apoptosis and repressed proliferation both in vitro and in vivo of human lung carcinoma.

Multitaxa assessment of carryover ecotoxicity following three hospital wastewater treatments

Pollutants affect taxa in different ways, which is why ecotoxicity bioassays should be conducted on several species. Bioassays play a key role in improving hospital wastewater (HWW) technologies, which are beset, firstly, by remaining toxicity (inefficiency); and secondly, by toxicity caused by each technology belonging to an HWW treatment train. Both effects constitute carryover toxicity (CT).A new CT test based on four harmonized bioassays (approved by both US Environmental Protection Agency and the Organization for Economic Cooperation and Development, EPA-OECD) was developed to assess three wastewater technologies. Real-life complexity (the multiplicity of technologies, xenobiotics, taxa in trophic networks, and endpoints), as well as ill-suited conventional metrics warranted the use of information theory tools (entropy, chemometrics with principal components analysis, sensitivity and specificity, receiver-operating characteristic) and a Bayesian model (to identify screening and confirmatory capabilities of the CT test).The CT assessment showed that the effect of zeolite with hexadecyltrimethylammonium bromide (Ze) on Daphnia pulex had the highest toxicological cost. This cost was the inhibition or induction entailed by Ze or chlorination (Cl) disinfection given that anaerobic and aerobic digestion (AnA) fomented growth of coliforms.The dose-response curves showed a consistent pattern whereby the point called knee summarized most of the information (i.e., correlated well with the information entropy, R2 = 0.77). Sensitivity (Se) and specificity (Sp) of the 3-taxa test were high (rates of true positives and true negatives were 0.73 and 0.87, respectively). The knee was interpreted as the point at which induction or inhibition plateaued, that is, toxic saturation occurred.Physicochemical results pointed to fat, oil and grease (FOG) associated to total P as clear predictors of induction of bioindicator population growth, possibly related to the action of hormones and pharmaceutical endocrine disruptors (EDs) present in the hospital's pharmacopeia and patients' excreta. In turn, inhibition of population growth was related to high COD.

Enhanced and sustainable control of Myzus persicae by repellent plants in organic pepper and eggplant greenhouses.

Repellent plants (RPs), generally used to keep pests away from crops in integrated pest management, have been shown to reduce the need for synthetic insecticide sprays in various agroecosystems. However, few studies have evaluated the pest control efficiency of RPs over the entire growth period of crops. To evaluate the effect of RPs against Myzus persicae and explore the application and management modes of RPs in the field, we planted mint (Mentha haplocalyx), mung bean (Vigna radiata), celery (Apium graveolens) and coriander (Coriandrum sativum) near the ventilation openings of commercial greenhouses. Five-month sampling results showed that mung bean and mint treatments significantly reduced M. persicae population levels over the entire growth period, whereas celery and coriander reduced aphid infestations during the main harvest period of eggplant. The four RP species showed the strongest repellence during their fast-growth periods. Mung bean and mint shortened the activity period of M. persicae in pepper by delaying the pest in reaching its peak activity. Celery and coriander reduced aphid density on eggplant during their main activity period. Mint, celery and coriander inhibited population growth in M. persicae in the laboratory, revealing the potential value of RPs in reducing M. persicae population levels in the field. Mint, mung bean, celery and coriander planted near ventilation openings could be used to control M. persicae infestations in commercial greenhouses. Early planting and timely replanting of RPs is a more effective, environmentally friendly and suitable method for organic pest control compared with chemical pesticides. © 2021 Society of Chemical Industry.

Chronic toxicity of new pyridine-n-oxide derivatives for tetrahymena pyriformis w, determination of “structure-toxicity”, “concentration-time-effect” correlation

There is a considerable amount of work in the scientific literature on nonlinear (“paradoxical”) effects, but their toxicological significance for the body is still poorly understood. Plant growth regulators are biologically active substances at the level of low and ultra-low doses and concentrations, they are widely used in agriculture. To date, the mechanisms of their toxic and specific effects on the body, the presence of “paradoxical” effects at low doses have not been sufficiently studied. Thus, it is important to further indepth study of the “concentration-time-effect” relationship under chronic exposure to the body, which will be important for understanding the general biological processes, developing approaches to hygienic regulation and risk assessment for human health and non-target environmental objects. The Aim of the Research. Determine the dependence of “structure-toxicity”, “concentration-time-effect” of plant growth regulators – pyridine-N-oxide derivatives under conditions of chronic effects on the body of ciliates Tetrahymena pyriformis W. Materials and Methods. The object of research was complexes of methyl derivatives of pyridine-N-oxide with organic acids and metal salts. Studies were performed on ciliates of Tetrahymena pyriformis W in the stationary phase of growth. The chronic effect of plant growth regulators on ciliates was studied in a 96-hour experiment in the concentration range from 1×10 -2 M to 1×10-28 M. The initial number of ciliates in the sample was 20,000 cells/ml of culture medium. The samples were incubated in a dry air thermostat at 25°C. After 24, 48, 72, 96 hours, the number of ciliates in different growth phases was determined. The experiments were performed in four replicates. The results of the research were subjected to mathematical processing by methods of variation statistics using the standard software package Microsoft® Office Excel 2010. Results. It is shown that at a concentration of 1×10-2 M investigated complexes of methyl derivatives of N-oxidepyridine with metal salts are more toxic than with organic acids. In the range of concentrations from 1×10-4 M to 1×10-28 M dependence "concentration-timeeffect" was not detected. Regardless of the concentration and duration of action, both inhibition and induction of ciliate population growth were observed. The change in the direction of the effect was observed at the level of high, low and ultralow concentrations. Conclusions. 1. Under conditions of chronic exposure to the population of ciliates Tetrahymena pyriformis W, the rate of growth inhibition at a concentration of 1×10-2 M, studied complexes DG-377 (Di-2,6-dimethylpyridine-N-oxide with ZnCl2), DG-380 (Di-2,6-dimethylpyridine-N-oxide with ZnI2), DG-387 (Di-2,6-dimethylpyridine-N-oxide with CoCl2), DG-480 (2-methylpyridineN-oxide with CoCl2), DG-471 (Di-2-methylpyridine-N-oxide with CoI2) are more toxic than similar complexes with organic acids – DG-361a (2,6-dimethylpyridine-N-oxide with succinic acid), DG-361 (Di-2,6-dimethylpyridine-N- with succinic acid), DG-362 (2,6-dimethylpyridine-N-oxide with maleic acid), DG-349a (2-methylpyridine-N-oxide with succinic acid). 2. In the range of concentrations from 1×10-4 M to 1×10 -28 M, regardless of the concentration and time of action, there is both inhibition and induction of growth of the ciliate population. The change in the direction of the effect was observed at the level of high, low and ultralow concentrations. The growth of the ciliate population, depending on the concentrations of the studied substances and the time of exposure, was polymodal in nature. 3. According to the direction and severity of the effect on the growth of the ciliate population for DG-361a, DG-361, DG-377, DG-387, DG-349a and DG-480 is characterized mainly by an inhibitory effect. The stimulating effect was observed in some phases of growth and was moderate or weak. For DG-362, DG-380 and DG-471 is characterized by a pronounced stimulation of population growth of ciliates. Key Words: methyl derivatives of pyridine-N-oxide, ciliates, “structure-toxicity”, “concentration-time-effect”.

Forty years later: monitoring and status of the endangered Coachella Valley fringe-toed lizard

The Coachella Valley fringe-toed lizard, Uma inornata, was listed as endangered under the California Endangered Species Act in 1980. By that time, the lizard’s habitat was already reduced by 90%, fragmented into isolated habitat islands on private property among hundreds of landowners. Ecosystem processes that are essential for delivering sand and maintaining the lizard’s sand dune habitat were already compromised. As challenging as it was to protect its habitat under these conditions, populations of this lizard still occur across much of the area where it was found forty years ago. Annual monitoring was designed to assess the ongoing viability of these populations by quantifying the effects of potential threats and stressors and focusing adaptive management actions where they are most needed. Here we demonstrate how hypothesis-based monitoring identified specific locations where invasive plant control and sand corridor management were needed to maintain the lizard’s populations. By monitoring lizard densities within the context of environmental variables that either drive or inhibit population growth, this monitoring approach informs if, when, and where management actions are needed.

Complete Characterization of Degradation Byproducts of Olmesartan Acid, Degradation Pathway, and Ecotoxicity Assessment

Antihypertensive drugs are among the most prescribed drugs. Olmesartan acid, of the sartan class, belongs to a relatively new generation of antihypertensive drugs called angiotensin II receptor blockers. There are very few studies on the presence and fate of sartans in the environment, despite them being marketed in huge quantities, metabolized in low percentages, and detected in wastewater and water bodies. This paper presents a study on the less abundant and more polar fractions that have been neglected in previous studies, which led to the isolation by chromatographic methods of thirteen degradation byproducts (DPs), six of which are new, identified by nuclear magnetic resonance and mass spectrometry. A mechanism of degradation from the parent drug was proposed. The ecotoxicity of olmesartan acid and identified compounds was evaluated in Aliivibrio fischeri bacteria and Raphidocelis subcapitata algae to assess acute and chronic toxicity. For 75% of the DPs, acute and chronic exposure to the compounds, at concentrations of 5 mg/L, inhibited population growth in the algae and decreased bioluminescence in the bacteria.