Potential Competitors Research Articles

Food-plant choice of seven dominant grasshopper species in the Xinjiang grasslands

Feeding habits and competitive interactions among dominant grasshopper species in the Xinjiang grasslands (China) were studied under natural conditions through microscopic analyses of insect crop contents. Sex-specific and interindividual differences in feeding habits and interspecific competition were investigated. Analyses of ecological niche width and overlap revealed potential competition among grasshoppers. The results showed significant difference in the sex-specific variations in the feeding habits of the seven grasshoppers; sex-specific variations in feeding range and preferred plants were observed, with females feeding more extensively on host plants, and female and male adults choosing to feed on different plant species. Individuals of all seven grasshoppers showed different degrees of dietary variance, with oligophagous grasshoppers (Oedaleus decorus males, Dericorys annulata, and Bryodema gebleri males) showing a smaller degree of individual dietary variance than polyphagous grasshoppers (Oedipoda caerulescens, Calliptamus coelesyriensis females, Calliptamus barbarus, and Notostaurus albicornis); Calliptamus coelesyriensis and Notostaurus albicornis showed the greatest individual variance in their diets. Oedaleus decorus, Bryodema gebleri, and Calliptamus barbarus consumed primarily Poaceae and exhibited varying foot-plant choice. For example, Oedaleus decorus was observed to have high- preference feeding for Poa annua, Bryodema gebleri for Stipa capillata, and Calliptamus barbarus for Setaria viridis. Dericorys annulata fed primarily on Amaranthaceae, Notostaurus albicornis fed primarily on Poaceae and Amaranthaceae, and Oedipoda caerulescens fed primarily on Asteraceae. Calliptamus barbarus exhibited strong interspecific competition with Oedaleus decorus and Calliptamus coelesyriensis, and Bryodema gebleri demonstrated the strongest interspecific competition with all six other species. Considering the influence of sex on interspecific competition among grasshoppers enhances our understanding of interspecific competitive relationships.

Large-scale overlap and fine-scale avoidance: assessing interactions between coyotes, bobcats, and cougars at multiple scales

Abstract In multi-carnivore systems individuals must forage and reproduce while also competing with other carnivores and avoiding intraguild predation. These interactions may vary by strength and scales across different ecosystems. We used occupancy analyses and attraction–avoidance indices to assess large- and fine-scale interactions, respectively, between Cougars (Puma concolor), Bobcats (Lynx rufus), and Coyotes (Canis latrans) in northeast Oregon based on data from camera traps set during the summer and fall of 2016 and 2017. To determine the importance of habitat preferences and spatial overlap, we compared occupancy (probability of use) models that included habitat covariates with and without species co-occurrence terms. Detection was different for all species and was influenced by roads, game trails, and canopy cover. Terrain ruggedness was important for all species; Bobcats showed the strongest preference for ruggedness, Cougars showed a weak preference, and Coyotes significantly but weakly avoided rugged areas. The top probability of use model showed that Bobcats and Coyotes were 1.88 times more likely to spatially overlap on roads. We also found evidence that interactions among carnivores were scale-dependent. At larger scales, habitat preference was more important than interactions with other carnivores, whereas at finer scales, most carnivores avoided each other. At fine spatiotemporal scales, our attraction–avoidance analyses showed that Bobcats avoided Coyotes and Coyotes avoided both Bobcats and Cougars. These findings suggest that carnivores in our study system were adept at minimizing conflict through fine-scale avoidance in space and time, that the human footprint can influence carnivore interactions, and that studying carnivore interactions at multiple scales is important for understanding the effects of spatial overlap and potential competition.

Patents, Freedom to Operate, and Follow-on Innovation: Evidence from Post-Grant Opposition

We study the blocking effect of patents on follow-on innovation by others. We posit that follow-on innovation requires freedom to operate (FTO), which firms typically obtain through a license from the patentee holding the original innovation. Where licensing fails, follow-on innovation is blocked unless firms gain FTO through patent invalidation. Using large-scale data from post-grant oppositions at the European Patent Office, we find that patent invalidation increases follow-on innovation, measured in citations, by 16% on average. This effect exhibits a U-shape in the value of the original innovation. For patents on low-value original innovations, invalidation predominantly increases low-value follow-on innovation outside the patentee’s product market. Here, transaction costs likely exceed the joint surplus of licensing, causing licensing failure. In contrast, for patents on high-value original innovations, invalidation mainly increases high-value follow-on innovation in the patentee’s product market. We attribute this latter result to rent dissipation, which renders patentees unwilling to license out valuable technologies to (potential) competitors. This paper was accepted by Ashish Arora, entrepreneurship and innovation. Funding: This work was supported by the Deutsche Forschungsgemeinschaft [Collaborative Research Center TRR 190]. F. Gaessler acknowledges financial support from the Spanish Agencia Estatal de Investigación through the Severo Ochoa Programme for Centres of Excellence in R&D [Barcelona School of Economics CEX2019-000915-S]. Supplemental Material: The online appendices and data files are available at https://doi.org/10.1287/mnsc.2019.02294 .

Starch-mediated colloidal chemistry for highly reversible zinc-based polyiodide redox flow batteries

Aqueous Zn-I flow batteries utilizing low-cost porous membranes are promising candidates for high-power-density large-scale energy storage. However, capacity loss and low Coulombic efficiency resulting from polyiodide cross-over hinder the grid-level battery performance. Here, we develop colloidal chemistry for iodine-starch catholytes, endowing enlarged-sized active materials by strong chemisorption-induced colloidal aggregation. The size-sieving effect effectively suppresses polyiodide cross-over, enabling the utilization of porous membranes with high ionic conductivity. The developed flow battery achieves a high-power density of 42 mW cm−2 at 37.5 mA cm−2 with a Coulombic efficiency of over 98% and prolonged cycling for 200 cycles at 32.4 Ah L−1posolyte (50% state of charge), even at 50 °C. Furthermore, the scaled-up flow battery module integrating with photovoltaic packs demonstrates practical renewable energy storage capabilities. Cost analysis reveals a 14.3 times reduction in the installed cost due to the applicability of cheap porous membranes, indicating its potential competitiveness for grid energy storage.

Spatial distribution models for the four commercial tuna in the sea of maritime continent using multi-sensor remote sensing and maximum entropy

The dynamic of marine environmental parameters affects the distribution of commercial tuna in the sea of the maritime continent. Hence, the objectives of this study are to develop spatial distribution models for the four main tuna species in the Maritime continent's sea with reasonable accuracy, identify their correlation with marine environmental parameters, and investigate areas of interaction between those tuna species. The study develops the distribution models for albacore (Thunnus alalunga), bigeye (Thunnus obesus), yellowfin (Thunnus albacares), and skipjack (Katsuwonus pelamis) tuna species, utilizing multi-sensor satellite remote sensing and maximum entropy. The results show models have good performance, focusing on environmental factors such as sea surface temperature (SST), chlorophyll-a (CHL), and sea surface height anomalies (SSHA), combined with eddy kinetic energy (EKE). Seasonal variations in potential tuna habitats are revealed, emphasizing the influence of those marine environmental conditions. From December to May, the four commercial tuna species were distributed in conditions characterized by SST of 26–31.5 °C, CHL levels of 0–3 mg/l, SSHA of −0.3 to 0.2 m, and EKE of 0–1 m2/s2, while from June to November, they experienced SST of 23–31 °C, CHL levels of 0–4 mg/l, SSHA of −0.5 to 0.3 m, and EKE of 0–1.1 m2/s2. The spatial persistence of the four tuna species emerged mainly around the south sea of Java, with skipjack being the most common species found in the sea of the maritime continent. With sufficient and evenly distributed tuna presence records, the results indicate the potential for extrapolation beyond the training data to estimate habitat suitability for the four commercial tuna distributions. The results also suggest potential competition between tuna species sharing ecological niches and highlight possible overlapping areas where different tuna species interact with the same fishing gear.

Social interactions and information use by foraging seabirds.

What do seabirds perceive about the world? How do they do so? And how do they use the information available to them to make foraging decisions? Social cues provide seabirds with information about the location of prey. This can, of course, be passive and not involve higher-order cognitive processes (e.g. simple conspecific or heterospecific attraction). However, seabirds display many behaviours that promote learning and the transmission of information between individuals: the vast majority of seabirds are colonial living, have an extended juvenile phase that affords them time to learn, routinely form intra- and interspecific associations, and can flexibly deploy a combination of foraging tactics. It is worth evaluating their foraging interactions in light of this. This review describes how seabirds use social information both at the colony and at sea to forage, and discusses the variation that exists both across species and amongst individuals. It is clear that social interactions are a critical and beneficial component of seabird foraging, with most of the variation concerning the way and extent to which social information is used, rather than whether it is used. While it may seem counterintuitive that large groups of potential competitors congregating at a patch can result in foraging gains, such aggregations can alter species dynamics in ways that promote coexistence. This review explores how competitive interference at a patch can be mitigated by behavioural modifications and niche segregation. Utilising others for foraging success (e.g. via social cues and facilitation at a patch) is likely to make population declines particularly damaging to seabirds if the quantity or quality of their social foraging interactions is reduced. Environmental changes have the potential to disrupt their social networks and thus, how these species obtain food and transfer information.

Regulation and activity of Runx2 in CD8+ T cells responding to infection promotes long-term survival

Abstract Constitutive expression of Runx family proteins in CD8 T cells and maintenance of accessibility surrounding Runx motifs in regulatory regions of lineage-specific loci suggest that they may play a role in establishing and maintaining the epigenetic state of CD8 T cells. Additionally, Runx proteins possess a highly homologous DNA binding domain, leading not only to redundancies, but also potential competition between Runx proteins for the same genomic binding sites. While Runx1 and Runx3 have well known roles in the development of CD8 T cells, the function of Runx2 is not well established. To further explore the function of Runx2, our lab utilizes a model of retroviral overexpression and CRISPR knockout of Runx proteins in OT-1 CD8 T cells. Adoptive transfer of Runx2 overexpressing or knockout cells followed by ovalbumin-expressing Listeria monocytogenes (LmOva) infection suggests that Runx2 activity is important for the expression and maintenance of genes needed for long-term survival and function, such as Tcf7 and Il7ra. Data analyzed from the literature and chromatin analyses from our lab suggest that Runx proteins may compete for binding sites and drive opposing transcriptional and epigenetic profiles in CD8 T cells after infection. Preliminary data also give insight into the mechanisms controlling Runx2 expression, suggesting that the signals received during priming may affect the balance of Runx protein activity.

Community ecology in a bottle: Leveraging eDNA metabarcoding data to predict occupancy of co‐occurring species

AbstractDetecting environmental DNA (eDNA) of numerous organisms from the same samples has been revolutionized by metabarcoding. However, utilizing the vast amounts of data generated from metabarcoding to predict occupancy probabilities for co‐occurring species is currently rare. Here, we demonstrate how metabarcoding data can be used to advance community ecology research through a case study using replicate stream water samples and Bayesian occupancy models to test hypotheses of eDNA occurrence for a native fish (brook trout, Salvelinus fontinalis), its major ectoparasite (gill lice, Salmincola edwardsii), and an introduced potential competitor (brown trout, Salmo trutta). Gill lice DNA occupancy was positively associated with brook trout biomass determined via electrofishing conducted near eDNA sampling sites, suggesting gill lice occupancy is dependent on host density. Leveraging site‐specific molecular operational taxonomic units identified from metabarcoding, DNA occupancy of trout and gill lice was often positively predicted by species richness of aquatic insect orders trout commonly feed on, which are also environmental quality indicators. Thus, high‐quality habitats that environmentally sensitive salmonids and their primary prey rely on may promote higher fish occupancy rates, further facilitating the spread of fish parasites. An increasing amount of community‐level data is being generated from global metabarcoding efforts, and we suggest our framework could be broadly implemented to enhance understanding of factors impacting distributions of co‐occurring species, reveal new ecological phenomena, and support management and conservation efforts.

Sustainable utilization of sugarcane bagasse for wood-based panels: A promising approach for waste management in Egypt

One method to sustainable development is to reduce waste generation and recycle it in a way that contributes to the economic, social, and environmental goals of sustainable development. The study focuses on particle board production from Sugar Cane Bagasse (SCB). Various fiber-matrix combinations were used to create composites using SCB and epoxy resin matrix. Mechanical testing and water absorbance tests were employed to assess the effects of the epoxy content (0–25 wt%). The outcomes demonstrated that the optimal tensile strength of bio composites was attained by the 25 wt% of epoxy with SCB (18.49 Mpa). The water resistance duration property was improved in this study to reach 120 hours by mixing SCB with 25% epoxy. The results show that sugarcane bagasse-epoxy composites demonstrated acceptable mechanical and multifunctional properties. This portrays the effectiveness of Sugarcane bagasse and it a potential competitor to wood-based structural panels. The study uses the open LCA program to conduct a cradle-to-gate life cycle assessment of binder-less particleboard from sugarcane waste manufacturing. Additionally, the study provided an overview of the cost estimation involved in utilizing bagasse as a substitute for MDF particle boards. Furthermore, the influence of pressing temperature on the properties of the particle boards is investigated.

Measuring Regional Competitiveness: New Insights Based on the RCI

The design of a comprehensive measure of regional competitiveness has attracted much attention, with the Regional Competitiveness Index (RCI) as a benchmark. We contribute from two different perspectives. On the one hand, we test the robustness of the RCI results by modifying the dimensionality reduction technique. On the other hand, we explore the importance of two factors in the analysis of regional competitiveness: geographical distance to potential competitors (by correcting the index with the introduction of several distance measures) and technological specialization (by making a prior selection of the regions that are expected to compete mostly either in high-tech sectors or in medium- or low-tech sectors, and recalculating the index accordingly). The results show that the RCI indicator is robust to the variable reduction methods employed. Moreover, including geographical distance substantially modifies the degree of competitiveness of many regions, which we believe cannot be neglected since competition tends to be fiercer the shorter the distance between the regions involved. Finally, if regions are categorized into two groups based on their technology level, some changes in RCI rankings are very noticeable.

Development of a group II intron-based genetic manipulation tool for Streptomyces.

The availability of an alternative and efficient genetic editing technology is critical for fundamental research and strain improvement engineering of Streptomyces species, which are prolific producers of complex secondary metabolites with significant pharmaceutical activities. The mobile group II introns are retrotransposons that employ activities of catalytic intron RNAs and intron-encoded reverse transcriptase to precisely insert into DNA target sites through a mechanism known as retrohoming. We here developed a group II intron-based gene editing tool to achieve precise chromosomal gene insertion in Streptomyces. Moreover, by repressing the potential competition of RecA-dependent homologous recombination, we enhanced site-specific insertion efficiency of this tool to 2.38%. Subsequently, we demonstrated the application of this tool by screening and characterizing the secondary metabolite biosynthetic gene cluster (BGC) responsible for synthesizing the red pigment in Streptomyces roseosporus. Accompanied with identifying and inactivating this BGC, we observed that the impair of this cluster promoted cell growth and daptomycin production. Additionally, we applied this tool to activate silent jadomycin BGC in Streptomyces venezuelae. Overall, this work demonstrates the potential of this method as an alternative tool for genetic engineering and cryptic natural product mining in Streptomyces species.

A Financial Analysis of Ryanair in UK Market

This report evaluates external environment and internal environment of Ryanair. It has certain competitiveness in the UK market, but it still faces challenges from potential entrants, suppliers, buyers, substitutes and industry competitiveness. In order to remain competitive in the market and meet customer needs, Ryanair airlines need to continuously innovate and improve services, while establishing long-term and stable cooperative relationships with partners to achieve sustainable development. The conclusion is that Ryanair has recovered from the pandemic downturn in 2023 financial year. Its risks are identified and risk management measures are analysed. First, Ryanair faces legal risks as it faces increasingly complex data protection laws and regulations. Second, in a highly competitive industry, the company faces operational risk from being exposed to significant price and other pressures. Third, Ryanair faces financial risks. Fourth, Ryanair faces cybersecurity risks and may incur increasing costs to minimize these risks. Within the company, Ryanair has established a clear functional organizational structure and clear division of responsibilities and authorities including the appointment of head of internal audit and the chief risk officer. Ryanair has implemented a risk management program across the company, with senior management responsible for reviewing and monitoring the financial and non-financial controls in place to manage risks to the business.

KEY ASPECTS OF THE TRANSFORMATION OF THE CHARACTER OF COMPETITION ON THE UKRAINIAN FOOD MARKET

The set of opportunities of an agricultural enterprise to create competitive advantages make up the potential of its competitiveness. However, competitive advantages, especially those that can be characterized as sustainable, are formed on the basis of the mobilization of the economic potential of the enterprise, which is a set of opportunities for the long-term implementation of the main activity of the business entity. Accordingly, the study identified the place and role of the potential of competitiveness in the structure of the enterprise's potential and its relationship with the economic potential. In turn, it was established that the components of economic potential are production potential in combination with commercial and sales opportunities, the basis of all types of enterprise potential is resource potential, and the potential of product competitiveness and enterprise competitiveness is based on the economic potential of the enterprise, contributing to the growth of the latter. Agricultural producers face many problems that can prevent them from growing and selling their products profitably. The problem of ensuring the effective economic activity of the studied subjects of agricultural production lies in the relative complexity of the relationships between them within the framework of the current market environment. the market environment of the functioning of commercial structures is not homogeneous, and the levers of state regulation do not have an unequivocal effect on all operators of one or another commodity market at the same time. To increase productivity and expand participation in market relations, they absolutely need appropriate mechanisms and policy measures. In the current situation, it becomes necessary for each manufacturer to analyze its competitiveness and develop effective means to increase it. An important condition for ensuring the competitiveness of enterprises is the effective use of resources, personnel qualifications, achievements of modern management, innovative, financial and informational capabilities of the enterprise, which together represent its potential. State determination of the legal field of existence of market participants requires a clear understanding of the relevant state of their interaction and the development trends of this interaction. The consequences of agricultural regulation policy and the manifestation of market forces in relation to the productivity and evolution of the food industry vary depending on the field, direction of production, etc.

The hydrometallurgical recovery of critical and valuable elements from WEEE shredding dust: Process effectiveness in a life cycle perspective

Waste electrical and electronic equipment (WEEE) recycling stands as a crucial opportunity to get critical resources while managing a waste stream in accordance with the circular economy principles. Recently, a two-step hydrometallurgical process has been successfully investigated to treat the dust originating from the mechanical processing of WEEE. The best operating conditions selected in this study were used to further investigate the recovery of precious metals and critical elements, achieving extraction yields of approximately 77.7 % and 53.1 %, respectively; base metals (i.e. aluminum, zinc, copper, ..) were also leached from dust up to 96 %. A life cycle approach was also applied to preliminary assess and compare the potential environmental impact of the proposed process with respect to the manufacturing process of the virgin material. The analysis focused on standard environmental indicators (i.e. global warming potential, acidification, …), human toxicity and eco-toxicty and a set of five different characterisation models for abiotic depletion of resources. Four scenarios, differing for allocation criteria (mass/economic) and the possible recovery of metals along with REEs, were compared. Among the recovered products, the greates potential benefits were found in the case of rare earth elements, in the scenario considering the complete recovery of base and precious metals and performing an economic allocation. Impacts on abiotic depletion and toxicity account for the highest benefits from maerial recovery. Nevertheless, the recovery of sulphuric acid would allow a further reduction also in other impacts, strengthening the potential competitiveness of REE recovery against the manufacturing of virgin materials.

Probing new physics with polarization components of the tau lepton in quasielastic e−p→Λcτ− scattering process

Kinematics restricts the ability of rare charm decays to explore the charged lepton-flavor-violation processes mediated by the quark-level c→uℓτ transition. To fill the gap, we propose exploring new physics (NP) through the quasielastic scattering process e−p→τ−Λc and the polarization of the τ lepton. As analyzing modes for the τ polarization, we consider the decays τ−→π−ντ, τ−→ρ−ντ, and τ−→ℓ−ν¯ℓντ, and show that the τ polarization components can be extracted from analyzing the kinematics of the τ visible decay products. In the framework of a general low-energy effective Lagrangian, we then perform a detailed analysis of the polarization components in various aspects and scrutinize possible NP signals. With one upcoming experimental setup, we finally demonstrate promising event rate can be expected for the cascade process and, even in the worst-case scenario—no signals are observed at all—it can still provide a competitive potential for constraining the NP, compared with those from the high-pT dilepton invariant mass tails at high-energy colliders. Published by the American Physical Society 2024

The Future of Energy Storage in Vietnam: A Fuzzy Multi-Criteria Decision-Making Approach to Metal-Ion Battery Assessments

Lithium-ion (Li-ion) batteries, despite their prevalence, face issues of resource scarcity and environmental concerns, prompting the search for alternative technologies. This study addresses the need to assess and identify viable metal-ion battery alternatives to Li-ion batteries, focusing on the rapidly industrializing context of Vietnam. It acknowledges the criticality of developing a sustainable, cost-effective, and resource-efficient energy storage solution that aligns with the country’s growth trajectory. The primary objective is to evaluate the suitability of emerging metal-ion batteries—specifically sodium-ion (SIB), sodium-ion saltwater (SIB-S), magnesium-ion (MIB), and zinc-ion (ZIB)—for Vietnam’s energy storage needs, guiding future investment and policy decisions. A Fuzzy Multiple-Criteria Decision-Making (MCDM) approach is employed, incorporating both quantitative and qualitative criteria. This study utilizes the Fuzzy Best-Worst Method (BWM) to determine the relative importance of various performance indicators and then applies the Bonferroni Fuzzy Combined Compromise Solution (Bonferroni FCoCoSo) method to rank the battery alternatives. The SIBs emerged as the most promising alternative, scoring the highest in the overall evaluation. The MIBs and SIB-saltwater batteries displayed competitive potential, while the ZIBs ranked the lowest among the considered options. This research provides a strategic framework for energy policy formulation and investment prioritization. It contributes to the field by applying a fuzzy-based MCDM approach in a novel context and offers a structured comparative analysis of metal-ion batteries, enhancing the body of knowledge on sustainable energy storage technologies.

Broad collection of consumer data by Big Tech: exclusionary or exploitative abuse?

ABSTRACT The ability to gather and process large amounts of personal data is primarily held by a small group of companies. Some regulators, scholars, and practitioners have expressed concerns that major advertising-based platforms such as Google and Facebook may abuse their dominant position in the data market by requiring users to agree to the intensive collection of their data as a condition to the free access and use of those platforms’ core services. This raises the question of whether such broad collection of consumer data should be examined by European competition authorities as a foreclosure aiming at excluding current and potential competitors from the market of consumer data or as an excessive collection of personal data having the effect of lowering user’s privacy. This paper seeks to discuss this matter by examining the recent ruling in Meta by the European Court of Justice.

What bycatch tells us about the diet of harbor and gray seals and overlap with commercial fishermen

Northwest Atlantic harbor (Phoca vitulina vitulina) and gray (Halichoerus grypus atlantica) seal populations are recovering from early to mid-20th century exploitation, increasing their biological interactions and bycatch in Northeastern US commercial fisheries. We evaluated the seals’ diet composition and compared their prey to commercial catches to assess trophic overlap and potential competition with commercial fisherman target catches. We obtained 148 harbor and 178 gray seal stomach samples from bycatch events that occurred between 2004 and 2018. We learned from the hard part remains that the majority of seals bycaught are young-of-the-year (≤12 months old) that consume a wide breadth of prey across three trophic groups. There was a general dichotomy in extrinsic factors associated with seal diet in which 45% trophic niche separation was explained by non-overlapping harbor and gray seal phenology and pup haul-out locations that are adjacent to active fishing areas. Prey size estimated from fish otoliths and squid beaks recovered from stomach contents showed that gray seals consumed larger prey than harbor seals and prey sizes from both seals showed limited overlap with prey sizes caught by commercial gillnet fishermen. The most important prey to both seals included large (>20 cm) and small (≤20 cm) silver hake (Merluccius bilinearis), (≤40 cm) red hake (Urophycis chuss), gulf stream flounder (Citharichthys arctifrons), medium (21–40 cm) white hake (Urophycis tenuis), and (<50 cm) Atlantic cod (Gadus morhua). Important prey to harbor seals that did not overlap with gray seals were Acadian redfish (Sebastes fasciatus), Atlantic herring (Clupea harengus), longfin (Doryteuthis pealeii), and shortfin squid (Illex illecebrosus). They contrasted with prey important to gray seals that did not overlap with harbor seals: yellowtail flounder (Limanda ferruginea), sand lance (Ammodytes spp.), Urophycis spp., and fourspot flounder (Hippoglossina oblonga). Despite the potential bias associated with opportunistic bycatch sampling, this study demonstrates the importance and value of utilizing carcasses retained from bycatch events, is complimentary to newer methodologies (i.e., DNA meta-barcoding), and fills data gaps in our understanding of the role recovering harbor and gray seal populations have on Northeastern US regional food webs.

Hydrophilic membranes for effective removal of PFAS from water: Anti-fouling, durability, and reusability

Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants in natural water. The polyacrylonitrile ultrafiltration membrane with an average pore size of 10.9 nm, grafted with tertiary amino groups, and subsequently quaternized, was developed to effectively adsorb PFAS in the presence of co-existing competitors. It achieved over 98 % removal of perfluorooctane sulfonic acid (PFOS) at neutral pH. Over 90 % removal efficiency was recovered within four cycles through eluent regeneration. The removal mechanism was determined, through advanced characterization and theoretical analysis, as a synergistic process of electrostatic, hydrophobic, and dipole-dipole interactions. To address potential competition in adsorption caused by natural organic matter (NOM), membrane pores were regulated to achieve selective interception of humic acid (HA, a representative NOM). Effective PFOS removal (98.4 %) maintained in the presence of abundant competitors. Furthermore, the mild regeneration method led to a flux recovery rate of 99.0 %, underscoring its resistance to contamination. The effects of versatile NOM and surfactants were also evaluated, that insignificant reduction in removal efficiency was observed. After 144th regeneration cycles (equivalent), <15 % changed in grafting moieties and <13.5 % decreased in HA removal were observed, suggesting the durability on chemical composition and interception ability. Overall, the adsorptive membranes, with reusability, anti-fouling, and durability, showed great potential for remediation of PFAS from natural water.

Effects of simulated glyphosate drift to native prairie plants and canola-compatible Brassicaceae species of North Dakota, United States

This study evaluated effects to native plant and weedy Brassicaceae species growing in areas potentially affected by drift of glyphosate used with glyphosate-resistant canola (Brassica napus). Ten native grass and forb species were selected based on importance in prairie areas of North Dakota, US; and four introduced Brassicaceae species (Brassica juncea, Brassica nigra, Brassica rapa, and Sinapis arvensis ssp. arvensis) were selected based on their ability to cross with B. napus. Greenhouse-grown seedlings were treated with 0 (carrier control), 0.00056, 0.0032, 0.018 and 0.1 × a field application rate (FAR) of 829 g ha−1 acid glyphosate (g acid equivalent or a.e. ha−1), along with no spray plants; with each treatment repeated in two experiments. Shoot dry weight and height were measured 14 days after treatment, and data were subjected to analysis of variance or covariance followed by a Dunnett's multiple comparison test to obtain No-Observed-Adverse-Effect-Rates (NOAERs) for both parameters. A Weibull regression was used to obtain the rate producing a 25% reduction (ER25) for shoot dry weight or height for a limited number of species and experiment combinations. Based on NOAER values for both shoot dry weight and height, most native species had reductions in growth with 0.1 × FAR resulting in NOAERs of 0.018 × FAR for at least one experiment. Nassella viridula was the most sensitive native species, with a NOAER of 0.0032 × FAR for shoot dry weight and one experiment for height. The Brassicaceae species responded similarly to glyphosate as the native species, with NOAER values ranging from 0.0032 to 0.018 × FAR. Only four species had valid regression analyses for shoot dry weight or height resulting in ER25 values between 0.007 and 0.054 × FAR. Pascopyrum smithii and Schizachyrium scoparium were not affected by glyphosate as indicated by NOAER values. This study indicated that drift concentrations between approximately 0.003, but more commonly ≥0.1 × FAR (2.49 and 82.9 g ha−1 acid glyphosate, respectively) may affect the growth and potential competitiveness of selected native plant species, and Brassicaceae species sexually compatible with glyphosate-resistant B. napus in North Dakota.