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Microplastics (MPs) in subsurface environments are migratory and can carry heavy metals, increasing the extent of MP and heavy metal pollution. This study used quartz sand-filled column experiments to investigate the adsorption and cotransport behaviours of PS-MPs, O 3 , UV-aged PS-MPs, and Cu 2+ at different MP concentrations, ionic strengths, and ionic valences in a saturated porous medium. The results showed that when MPs migrate alone in the absence of an ionic background, higher concentrations have increased mobility. In contrast, an increase in the background ion concentration or ion valence inhibits the individual transport capacity of PS-MPs. An increase in the concentration of background ions or elevation in the valence state promotes Cu 2+ transport because of the action of the double electric layer on the surface of the colloid and the electrostatic repulsive forces combined with the background ions. The adsorption capacity of aged PS-MPs was stronger than that of PS-MPs because of the binding of the aged PS-MPs to Cu 2+ through complexation and electrostatic attraction. In the binary system of PS-MPs/Cu 2+ , PS-MPs promoted Cu 2+ transport and the mobility of Cu 2+ loaded by PS-MPs decreased with increasing background ion concentration. The cotransport results showed that MPs promote Cu 2+ transport in the following order: O 3 -aged Ps > UV-aged Ps > Ps, as the increasing cation concentration in the MPs and Cu 2+ occupies the PS surface adsorption sites. Overall, PS is an effective carrier for Cu 2+ . These findings offer fresh exploration concepts for the joint migration of MPs and heavy metals in underground settings.

Most migrating birds must replenish energy reserves during migration. Food availability significantly influences migratory routes and can even force migrants to detour, but still little is known about potential co-migration between insectivorous birds and their insect prey. To address this gap, we focused on day-flying insects and the insectivorous birds migrating through the Červenohorské sedlo mountain pass, Czech Republic. During four seasons of insect and bird trapping, using Malaise trap and mist-nets, respectively, we recorded 23 094 birds of 80 species and 35 087 migrating hoverflies (Syrphidae) of 47 species. We found a strong temporal correlation between the number of migrating hoverflies and insectivorous birds crossing the mountain pass. The observed pattern suggests that a similar phenomenon may occur in lowlands, where both groups stop over before and after crossing the mountains. These stopovers may provide migratory birds with abundant and reliable food resources. We also found that hoverflies comprised 88% of the biomass of all trapped insects, making them the most abundant potential prey of migrating birds. Our results outline the co-migration of birds and hoverflies and shed light on possible predator–prey dynamics during migration.

Microplastics (MPs) are abundant in soil and the subsurface environment. They can co-transport with pathogens or act as vectors for pathogens, potentially causing severe ecological harm. The interaction of MPs with pathogens is an important topic. To describe the origins and features of MPs in the subsurface environment, we evaluated relevant studies conducted in the laboratory and field groundwater habitats. We explore the interactions between pathogens and microplastics from three perspectives including the respective physicochemical properties of microplastics and pathogens, external environmental factors, and the binding between microplastics and pathogens. The effects of some interaction mechanisms and environmental factors on their co-transport are discussed. The key factors affecting their interaction are the particle size, specific surface area, shape and functional groups of MPs, the zeta potential and auxiliary metabolic genes of pathogens, and the hydrophobicity of both. Environmental factors indirectly affect MPs and the interaction and co-transport process of pathogens by changing their surface properties. These findings advance our knowledge of the ecological behavior of MPs–pathogens and the associated potential health hazards.

In recent years, the distribution and transport of microplastics (MPs) in aquatic environments have garnered significant research interest due to their interactions with sediments, which directly influence their migration pathways, deposition patterns, and ecological risks. This study reviews research on the co-migration of suspended sediments (SS) and MPs based on publications from the Web of Science and Engineering Village databases spanning 2011–2025. A co-occurrence network analysis of keywords was conducted using CiteSpace, and the literature was visualized accordingly. The study also investigates the distribution of MPs in sediments within Chinese waters as a case study. The spatiotemporal distribution of MPs is influenced by hydrological conditions (e.g., flow and runoff intensity) and MP properties (e.g., density, shape, polymer type). This paper provides a systematic overview of key physical processes in sedimentary environments, including MP aggregation, settling, burial, and resuspension. Hydrographic conditions, particle concentration, and material properties are identified as the primary factors governing their co-migration. At the microscopic level, interactions between MPs and SS are mainly controlled by van der Waals forces, electrostatic interactions, and covalent bonding. The co-migration of MPs and SS involves multi-mechanistic coupling governed by physical, chemical, and biological processes. This study offers a scientific basis for assessing pollution risks and developing effective management strategies. Graphical Abstract

Colorectal cancer (CRC) cells often metastatize to the liver. Cancer-associated fibroblasts (CAFs) enhance metastasis by providing cytokines that create a favorable microenvironment and by inducing co-dissemination with tumor cells. However, the mechanisms of co-metastatization remain elusive. The aim of this study is to assess the role of TGFβ₁in CRC cell–CAFs attachment and its impact on liver metastasis. CAFs were obtained after xenotransplantation of Mc38 cells into EGFP-C57BL/6 mice. Attachment experiments with CRC cells and CAFs (with or without TGFβ₁and the inhibitory peptide P17) were carried out, as well as in vivo liver metastasis assays. TGFβ₁induced adhesion of CRC cells to CAFs, whereas exposure to P17 abrogated this effect. Co-injection of Mc38 cells with CAFs intrasplenically increased liver metastasis, as compared to injection of tumor cells alone. Pretreatment of Mc38 cells with TGFβ₁enhanced the metastatic burden, in comparison to untreated Mc38 + CAFs. TGFβ₁-pretreated Mc38 cells co-metastatized with CAFs to the liver in a highly efficient way. Importantly, the metastatic burden was significantly reduced (p < 0.001) when P17 was administered in mice. The number of PCNA+ and CD-31+ cells was also reduced by P17 in these animals, indicating a decrease in proliferation and angiogenesis upon TGFβ₁signaling blockade. Through microarray analysis, we identified potential TGFβ₁-regulated genes that may mediate cancer cell–stroma interactions to increase metastasis. In conclusion, TGFβ₁promotes co-travelling of CRC cells and CAFs to the liver to enhance metastasis. Our results strongly support the use of TGFβ₁targeted drugs as a novel strategy to reduce liver metastasis in CRC patients.

Recent molecular approaches for the study of microbial communities such as PCR-cloning have enabled the detection and identification of as-yet-unculturable taxa. Cloning and sequencing of multiple samples is extremely laborious and expensive to perform thoroughly due to the large diversity involved. For this purpose, techniques such as denaturing gradient gel electrophoresis (DGGE) may be better suited. There is increasing evidence suggesting that DGGE of complex polymicrobial communities may be limited by co-migration of different sequences. In this study, we attempt to address this limitation by excising individual bands and running them through a shorter denaturant gradient, a process we have termed “denaturing gradient gel electrophoresis gel expansion” (DGGEGE).

Host identity is among the most important factors in structuring ectomycorrhizal (ECM) fungal communities. Both host–fungal coevolution and host shifts can account for the observed host effect, but their relative significance in ECM fungal communities is not well understood. To investigate these two host-related mechanisms, we used relict forests of Pseudotsuga japonica , which is an endangered endemic species in Japan. As with other Asian Pseudotsuga species, P. japonica has been isolated from North American Pseudotsuga spp. since the Oligocene and has evolved independently as a warm-temperate species. We collected 100 soil samples from four major localities in which P. japonica was mixed with other conifers and broadleaf trees. ECM tips in the soil samples were subjected to molecular analyses to identify both ECM fungi and host species. While 136 ECM fungal species were identified in total, their communities were significantly different between host groups, confirming the existence of the host effect on ECM fungal communities. None of the 68 ECM fungal species found on P. japonica belonged to Pseudotsuga -specific lineages (e.g., Rhizopogon and Suillus subgroups) that are common in North America. Most of ECM fungi on P. japonica were shared with other host fungi or phylogenetically close to known ECM fungi on other hosts in Asia. These results suggest that after migrating, Pseudotsuga -specific fungal lineages may have become extinct in small isolated populations in Japan. Instead, most of the ECM fungal symbionts on P. japonica likely originated from host shifts in the region.

Denaturing gradient gel electrophoresis (DGGE) is commonly utilized to identify and quantify microbial diversity, but the conditions required for different electrophoretic systems to yield equivalent results and optimal resolution have not been assessed. Herein, the influence of different DGGE system configuration parameters on microbial diversity estimates was tested using Symbiodinium, a group of marine eukaryotic microbes that are important constituents of coral reef ecosystems. To accomplish this, bacterial clone libraries were constructed and sequenced from cultured isolates of Symbiodinium for the ribosomal DNA internal transcribed spacer 2 (ITS2) region. From these, 15 clones were subjected to PCR with a GC clamped primer set for DGGE analyses. Migration behaviors of the resulting amplicons were analyzed using a range of conditions, including variation in the composition of the denaturing gradient, electrophoresis time, and applied voltage. All tests were conducted in parallel on two commercial DGGE systems, a C.B.S. Scientific DGGE-2001, and the Bio-Rad DCode system. In this context, identical nucleotide fragments exhibited differing migration behaviors depending on the model of apparatus utilized, with fragments denaturing at a lower gradient concentration and applied voltage on the Bio-Rad DCode system than on the C.B.S. Scientific DGGE-2001 system. Although equivalent PCR-DGGE profiles could be achieved with both brands of DGGE system, the composition of the denaturing gradient and application of electrophoresis time × voltage must be appropriately optimized to achieve congruent results across platforms.

Abstract Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) uses arbitrary primers and low stringency annealing conditions to amplify anonymous DNA fragments which are then depicted in agarose gels. RAPD-PCR fingerprints have been used for typing and differentiation of bacteria and, increasingly, for the study of genetic relationships between strains and species of microorganisms, plants and animals. The analysis of such fingerprints is based upon the assumption that co-migration of amplicons does not occur and that any given band contains a single amplicon. This report shows that co-migration of fragments of nearly identical size, but different nucleotide sequences, occurs between different isolates and within single RAPD-PCR bands from Aeromonas hydrophila. The possibility of the same phenomenon occurring for other prokaryotic or eukaryotic genomes argues for caution in the interpretation of RAPD-PCR fingerprints.

Many low-income countries and development organizations are calling for greater liberalization of labor immigration policies in high-income countries. At the same time, human rights organizations and migrant rights advocates demand more equal rights for migrant workers. The Price of Rights shows why you cannot always have both. Examining labor immigration policies in over forty countries, as well as policy drivers in major migrant-receiving and migrant-sending states, Martin Ruhs finds that there are trade-offs in the policies of high-income countries between openness to admitting migrant workers and some of the rights granted to migrants after admission. Insisting on greater equality of rights for migrant workers can come at the price of more restrictive admission policies, especially for lower-skilled workers. Ruhs advocates the liberalization of international labor migration through temporary migration programs that protect a universal set of core rights and account for the interests of nation-states by restricting a few specific rights that create net costs for receiving countries. The Price of Rights analyzes how high-income countries restrict the rights of migrant workers as part of their labor immigration policies and discusses the implications for global debates about regulating labor migration and protecting migrants. It comprehensively looks at the tensions between human rights and citizenship rights, the agency and interests of migrants and states, and the determinants and ethics of labor immigration policy.