Publications by authors named "Takeshi Miki"

Microbes in the dark oceans are a key determinant of remineralization of sinking carbon particles. However, most marine ecosystem models overlook how microbes aggregate on particles and the microscale interactions between particle-associated microbes, making it difficult to obtain mechanistic insights on their vertical power-law decay pattern. Here, we present a spatial population model where the attachment and detachment processes of bacterial cells depend on local density of particle-associated bacteria.

View Article and Find Full Text PDF

Plant traits, which are often species specific, can serve as environmental filtering for community assembly on plants. At the same time, the species identity of the initially colonizing arthropods would vary between plant individuals, which would subsequently influence colonizing arthropods and community development in the later stages. However, it remains unclear whether interindividual divergence due to priority effects is equally important as plant trait-specific environmental filtering in the initial stages.

View Article and Find Full Text PDF

Reliable survey of arthropods is a crucial for their conservation, community ecology, and pest control on terrestrial plants. However, efficient and comprehensive surveys are hindered by challenges in collecting arthropods and identifying especially small species. To address this issue, we developed a non-destructive environmental DNA (eDNA) collection method termed "plant flow collection" to apply eDNA metabarcoding to terrestrial arthropods.

View Article and Find Full Text PDF
Article Synopsis
  • During extreme rainfall, untreated sewage from combined sewer overflows (CSO) directly contaminates rivers, impacting water quality and microbial communities.
  • A study analyzed changes in water quality, bacterial structures, and microbial functions before and after the construction of a stormwater storage pipe, revealing that CSOs significantly alter microbial functions and community structures.
  • The research suggests that implementing stormwater storage pipes can reduce the acute microbial disturbances caused by CSOs, thus improving waterway management in urban environments.
View Article and Find Full Text PDF
Article Synopsis
  • Ecosystem functions are more impacted by biodiversity loss when focusing on specific functions rather than broad ones, mainly because specific functions often rely on fewer species.
  • This study analyzed 33 ecosystem functions over three years in a freshwater ecosystem, using regression models to assess the roles of specific species and substrate complexity.
  • The results showed that taxon-based functional specificity (related to the richness of key species) is a stronger indicator of functional redundancy than substrate-based complexity, offering a framework to better predict how biodiversity loss affects ecosystem performance.
View Article and Find Full Text PDF

Microbial interactions shape the structure and function of microbial communities with profound consequences for biogeochemical cycles and ecosystem health. Yet, most interaction mechanisms are studied only in model systems and their prevalence is unknown. To systematically explore the functional and interaction potential of sequenced marine bacteria, we developed a trait-based approach, and applied it to 473 complete genomes (248 genera), representing a substantial fraction of marine microbial communities.

View Article and Find Full Text PDF

Untangling causal links and feedbacks among biodiversity, ecosystem functioning, and environmental factors is challenging due to their complex and context-dependent interactions (e.g., a nutrient-dependent relationship between diversity and biomass).

View Article and Find Full Text PDF

Reconstructing interactions from observational data is a critical need for investigating natural biological networks, wherein network dimensionality is usually high. However, these pose a challenge to existing methods that can quantify only small interaction networks. Here, we proposed a novel approach to reconstruct high-dimensional interaction Jacobian networks using empirical time series without specific model assumptions.

View Article and Find Full Text PDF

How do skilled players change their motion patterns depending on motion effort? Pitchers commonly accelerate wrist and elbow joint rotations via proximal joint motions. Contrastingly, they show individually different pitching motions, such as in wind-up or follow-through. Despite the generality of the uniform and diverse features, effort-dependent effects on these features are unclear.

View Article and Find Full Text PDF

Viral infections are a major factor in diatom cell death. However, the effects of viruses on diatom dynamics remain unclear. Based on laboratory studies, it is hypothesized that virus-induced diatom mortality is dependent on the diatom growth rate.

View Article and Find Full Text PDF
Article Synopsis
  • - This study focused on identifying key mechanical factors that affect the accuracy of baseball pitching, specifically examining the "release parameters" at the moment the ball is thrown.
  • - Results showed that the elevation pitching angle and ball speed are crucial for vertical pitch location, while the azimuth pitching angle primarily affects horizontal pitch location.
  • - The research concluded that pitching angles have the most significant impact on pitch location, with variations in these parameters differing among individual pitchers, ultimately contributing to our understanding of skills required for accurate ball control in pitching.
View Article and Find Full Text PDF
Article Synopsis
  • - The study investigated the thermal deactivation of Pd/CeO-ZrO (Pd/CZ) three-way catalysts through structural analysis and catalytic testing to better understand their lifetime and performance under high temperatures.
  • - Aging the catalysts at 600-1100 °C revealed significant changes in palladium (Pd) particle size (10-550 nm), impacting the catalyst's performance and indicating that Pd/CZ had a more complex surface structure compared to a reference catalyst, Pd/AlO.
  • - Ultimately, the research highlighted that the activity difference between the two catalysts was linked to the role of ceria-zirconia (CZ) in oxygen storage and release, which was crucial for performance, particularly as Pd particles sin
View Article and Find Full Text PDF
Article Synopsis
  • - The study analyzed how the accuracy and consistency of baseball pitchers' pitches vary across different age groups: elementary school, junior high, high school, and college students.
  • - Results indicated that while pitching precision improved with age, the variability in form (measured by minor axis length of error ellipses) varied significantly, especially in younger pitchers.
  • - Notably, younger pitchers showed a strong correlation between the variability of their throwing arm's trajectory and their performance, suggesting greater inconsistency compared to older groups.
View Article and Find Full Text PDF
Article Synopsis
  • Understanding ecosystem responses to climate change requires analyzing how various components, like biodiversity and environmental factors, interact over time.
  • A study of 10 long-term aquatic ecosystems revealed that individual factors alone don't predict stability; it's the interconnected relationships that matter most.
  • Systems experiencing more warming showed weakened interactions and greater fluctuations, emphasizing the need for a holistic view to anticipate climate impacts on aquatic ecosystems.
View Article and Find Full Text PDF

Fungal diseases threaten natural and man-made ecosystems. Chytridiomycota (chytrids) infect a wide host range, including phytoplankton species that form the basis of aquatic food webs and produce roughly half of Earth's oxygen. However, blooms of large or toxic phytoplankton form trophic bottlenecks, as they are inedible to zooplankton.

View Article and Find Full Text PDF
Article Synopsis
  • Food-web complexity makes it difficult to understand how food-web structure affects biodiversity, prompting the need for a new theoretical framework.
  • This framework introduces a method called food network unfolding, which simplifies complex food webs into linear food chains and defines three biodiversity indices: horizontal diversity (D₁), vertical diversity (D₂), and range diversity (D₃).
  • Testing this framework on riverine macroinvertebrate communities showed that the D indices, derived from biomass and stable isotope data, effectively captured changes in food-web structure better than Shannon's diversity index (H').
View Article and Find Full Text PDF

Heterotrophic microbes with the capability to process considerable amounts of organic matter can colonize microplastic particles (MP) in aquatic ecosystems. Weather colonization of microorganisms on MP will alter ecological niche and functioning of microbial communities remains still unanswered. Therefore, we compared the functional diversity of biofilms on microplastics when incubated in three lakes in northeastern Germany differing in trophy and limnological features.

View Article and Find Full Text PDF

Chytridiomycota, often referred to as chytrids, can be virulent parasites with the potential to inflict mass mortalities on hosts, causing e.g. changes in phytoplankton size distributions and succession, and the delay or suppression of bloom events.

View Article and Find Full Text PDF

Recent efforts in controlling mosquito-borne diseases focus on biocontrol strategies that incapacitate pathogens inside mosquitoes by altering the mosquito's microbiome. A case in point is the introduction of Wolbachia into natural mosquito populations in order to eliminate Dengue virus. However, whether this strategy can successfully control vector-borne diseases is debated; particularly, how artificial infection affects population dynamics of hosts remains unclear.

View Article and Find Full Text PDF

The ultrafast femtochemistry of carotenoids is governed by the interaction between electronic excited states, which has been explained by the relaxation dynamics within a few hundred femtoseconds from the lowest optically allowed excited state S2 to the optically dark state S1. Extending this picture, some additional dark states (3A(g)(-) and 1B(u)(-)) and their interaction with the S2 state have also been suggested to play a major role in the ultrafast deactivation of carotenoids and their properties. Here, we investigate the interaction between such dark and bright electronic excited states of open chain carotenoids, particularly its dependence on the number of conjugated double bonds (N).

View Article and Find Full Text PDF

Plants affect microbial communities and abiotic properties of nearby soils, which in turn influence plant growth and interspecific interaction, forming a plant-soil feedback (PSF). PSF is a key determinant influencing plant population dynamics, community structure, and ecosystem functions. Despite accumulating evidence for the importance of PSF and development of specific PSF models, different models are not yet fully integrated.

View Article and Find Full Text PDF

The "rare biosphere" consisting of thousands of low-abundance microbial taxa is important as a seed bank or a gene pool to maintain microbial functional redundancy and robustness of the ecosystem. Here we investigated contemporaneous growth of diverse microbial taxa including rare taxa and determined their variability in environmentally distinctive locations along a north-south transect in the Pacific Ocean in order to assess which taxa were actively growing and how environmental factors influenced bacterial community structures. A bromodeoxyuridine-labeling technique in combination with PCR amplicon pyrosequencing of 16S rRNA genes gave 215-793 OTUs from 1200 to 3500 unique sequences in the total communities and 175-299 OTUs nearly 860 to 1800 sequences in the active communities.

View Article and Find Full Text PDF

The structure of FeOx species supported on γ-Al2 O3 was investigated by using Fe K-edge X-ray absorption fine structure (XAFS) and X-ray diffraction (XRD) measurements. The samples were prepared through the impregnation of iron nitrate on Al2 O3 and co-gelation of aluminum and iron sulfates. The dependence of the XRD patterns on Fe loading revealed the formation of α-Fe2 O3 particles at an Fe loading of above 10 wt %, whereas the formation of iron-oxide crystals was not observed at Fe loadings of less than 9.

View Article and Find Full Text PDF

Reciprocal interaction between plant and soil (plant-soil feedback, PSF) can determine plant community structure. Understanding which traits control interspecific variation of PSF strength is crucial for plant ecology. Studies have highlighted either plant-mediated nutrient cycling (litter-mediated PSF) or plant-microbe interaction (microbial-mediated PSF) as important PSF mechanisms, each attributing PSF variation to different traits.

View Article and Find Full Text PDF