1,781 results match your criteria: "a Graduate School of Biosphere Sciences; Hiroshima University ; Higashi-Hiroshima[Affiliation]"

Automated estimation of stomatal number and aperture in haskap (Lonicera caerulea L.).

Planta

September 2023

Division of Biosphere Science, Graduate School of Environmental Science, Hokkaido University, Kita 11, Nishi 10, Kita-ku, Sapporo, 060-0811, Japan.

This study developed the reliable Mask R-CNN model to detect stomata in Lonicera caerulea. The obtained data could be utilized for evaluating some characters such as stomatal number and aperture area. The native distribution of haskap (Lonicera caerulea L.

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Treatment with cholesterol just after thawing maintains the fertility of bull sperm.

Mol Hum Reprod

August 2023

Laboratory of Reproductive Endocrinology, Department of Bioresource Science, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.

Freezing and thawing diminish sperm motility and fertility by disrupting the cholesterol balance in sperm plasma and organelle membranes. The aim of this study was to elucidate the mechanisms through which exogeneous cholesterol treatment enhances the quality of frozen-thawed bull sperm. The incorporation of cholesterol was investigated using boron-dipyrromethene (BODIPY)-cholesterol, and BODIPY signals were detected not only in the plasma membrane but also in the midpiece region immediately after thawing.

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Role of trisaccharides in larval secretion of Lycaeides argyrognomon butterfly on ant attendance.

J Insect Physiol

November 2023

Graduate School of Integrated Sciences for Life, Hiroshima University, Higashihiroshima, Hiroshima 739-8528, Japan; Graduate School of Biosphere Science, Hiroshima University, Higashihiroshima, Hiroshima 739-8528, Japan. Electronic address:

Several myrmecophilous insects participate in symbiotic relationships with ants that receive sugar-rich food rewards. For instance, certain aphid species secrete honeydew containing high concentration of melezitose, which acts as a potent feeding-stimulant and attractant for ants. Lycaenid butterfly larvae possess dorsal nectary glands that secrete sugar-rich droplets for tending ants.

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Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies. Here, leveraging global tree databases, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity.

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Primary productivity response to climatic drivers varies temporally, indicating state-dependent interactions between climate and productivity. Previous studies primarily employed equation-based approaches to clarify this relationship, ignoring the state-dependent nature of ecological dynamics. Here, using 40 y of climate and productivity data from 48 grassland sites across Mongolia, we applied an equation-free, nonlinear time-series analysis to reveal sensitivity patterns of productivity to climate change and variability and clarify underlying mechanisms.

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Environmental pH signals the release of monosaccharides from cell wall in coral symbiotic alga.

Elife

August 2023

Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.

Reef-building corals thrive in oligotrophic environments due to their possession of endosymbiotic algae. Confined to the low pH interior of the symbiosome within the cell, the algal symbiont provides the coral host with photosynthetically fixed carbon. However, it remains unknown how carbon is released from the algal symbiont for uptake by the host.

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Deep learning-based high-throughput detection of in vitro germination to assess pollen viability from microscopic images.

J Exp Bot

November 2023

Division of Biosphere Science, Graduate School of Environmental Science, Hokkaido University, Kita 11, Nishi 10, Kita-ku, Sapporo 060-0811, Japan.

Article Synopsis
  • In vitro pollen germination is an effective way to evaluate pollen viability, relying on measuring germination frequency and pollen tube length.
  • This study introduces a Mask R-CNN model trained on microscopic images of tree peony pollen to quickly quantify germination rates and pollen tube lengths.
  • The model showed high accuracy, achieving a mean average precision of 0.949, and demonstrated its capability to be applied to other plant species, indicating broad potential for use in pollen viability assessments.
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In Ficus septica, the short-term control of isoprene production and, therefore, isoprene emission has been linked to the hormone balance between auxin (IAA) and jasmonic acid (JA). However, the relationship between long-term changes in isoprene emission and that of plant hormones remains unknown. This study tracked isoprene emissions from F.

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Jasmonate inhibits plant growth and reduces gibberellin levels via microRNA5998 and transcription factor MYC2.

Plant Physiol

October 2023

Program of Basic Biology, Graduate School of Integrated Science for Life, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan.

Jasmonate (JA) and gibberellins (GAs) exert antagonistic effects on plant growth and development in response to environmental and endogenous stimuli. Although the crosstalk between JA and GA has been elucidated, the role of JA in GA biosynthesis remains unclear. Therefore, in this study, we investigated the mechanism underlying JA-mediated regulation of endogenous GA levels in Arabidopsis (Arabidopsis thaliana).

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Forest-stream ecotones possess prominent detritus-based food webs, and Cs-contaminated litter can influence the contamination levels of animals inhabiting such ecosystems. The effects of leaching on contaminated litter induce greater absolute differences between the Cs concentrations of forest and stream litter in more contaminated sites. Because Cs concentrations in litter can be attenuated temporally, spatiotemporal patterns in the differences in Cs concentrations between forest and stream litter may vary depending on both the amount of Cs deposition and the passage of time.

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Plant mycorrhizal associations influence the accumulation and persistence of soil organic matter and could therefore shape ecosystem biogeochemical responses to global changes that are altering forest composition. For instance, arbuscular mycorrhizal (AM) tree dominance is increasing in temperate forests, and ericoid mycorrhizal (ErM) shrubs can respond positively to canopy disturbances. Yet how shifts in the co-occurrence of trees and shrubs with different mycorrhizal associations will affect soil organic matter pools remains largely unknown.

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Construction of multiple metagenome assembled genomes containing carbon monoxide dehydrogenases from anaerobic carbon monoxide enrichment cultures.

Arch Microbiol

July 2023

Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan.

Despite its toxicity to many organisms, including most prokaryotes, carbon monoxide (CO) is utilized by some aerobic and anaerobic prokaryotes. Hydrogenogenic CO utilizers employ carbon monoxide dehydrogenase (CODH) and energy-converting hydrogenase (ECH) to oxidize CO and reduce protons to produce H. Those prokaryotes constitute a rare biosphere and are difficult to detect even with PCR amplification and with metagenomic analyses.

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Article Synopsis
  • Mammalian megafauna are large animals that have been important for Earth's ecosystems for millions of years, but their numbers have been decreasing due to climate changes and the evolution of early humans.
  • The study looks at how the loss of different species of large herbivores in eastern Africa affected their roles in the environment over the last 7.4 million years.
  • It was found that significant changes in the environment and loss of diversity mainly started affecting how these herbivores interacted with their habitats during the mid-Pleistocene, when grasslands expanded and climates changed.
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The persistent exposure of coral assemblages to more variable abiotic regimes is assumed to augment their resilience to future climatic variability. Yet, while the determinants of coral population resilience across species remain unknown, we are unable to predict the winners and losers across reef ecosystems exposed to increasingly variable conditions. Using annual surveys of 3171 coral individuals across Australia and Japan (2016-2019), we explore spatial variation across the short- and long-term dynamics of competitive, stress-tolerant, and weedy assemblages to evaluate how abiotic variability mediates the structural composition of coral assemblages.

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Evaluation of binding capacity of circulating insulin-like growth factor binding protein-1b in salmonids using a ligand immunofunctional assay.

Comp Biochem Physiol A Mol Integr Physiol

October 2023

Field Science Center for Northern Biosphere, Hokkaido University, 3-1-1 Minato, Hakodate, Hokkaido 041-8611, Japan. Electronic address:

Insulin-like growth factor-binding proteins (IGFBPs) regulate the activity of insulin-like growth factor (IGF)-1. Among the three major circulating IGFBPs in salmonids, IGFBP-1b is an inhibitor of IGF activity induced under catabolic conditions. IGFBP-1b is considered to quickly sequester IGF-1 from the circulation.

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Few animal groups can claim the level of wonder that cephalopods instill in the minds of researchers and the general public. Much of cephalopod biology, however, remains unexplored: the largest invertebrate brain, difficult husbandry conditions, and complex (meta-)genomes, among many other things, have hindered progress in addressing key questions. However, recent technological advancements in sequencing, imaging, and genetic manipulation have opened new avenues for exploring the biology of these extraordinary animals.

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Atmospheric chemistry research has been growing rapidly in China in the last 25 years since the concept of the "air pollution complex" was first proposed by Professor Xiaoyan TANG in 1997. For papers published in 2021 on air pollution (only papers included in the Web of Science Core Collection database were considered), more than 24 000 papers were authored or co-authored by scientists working in China. In this paper, we review a limited number of representative and significant studies on atmospheric chemistry in China in the last few years, including studies on (1) sources and emission inventories, (2) atmospheric chemical processes, (3) interactions of air pollution with meteorology, weather and climate, (4) interactions between the biosphere and atmosphere, and (5) data assimilation.

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Ocean acidification (OA) and warming (OW) are major global threats to coral reef ecosystems; however, studies on their combined effects (OA + OW) are scarce. Therefore, we evaluated the effects of OA, OW, and OA + OW in the branching reef corals Acropora digitifera and Montipora digitata, which have been found to respond differently to environmental changes. Our results indicate that OW has a greater impact on A.

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The stability and resilience of the Earth system and human well-being are inseparably linked, yet their interdependencies are generally under-recognized; consequently, they are often treated independently. Here, we use modelling and literature assessment to quantify safe and just Earth system boundaries (ESBs) for climate, the biosphere, water and nutrient cycles, and aerosols at global and subglobal scales. We propose ESBs for maintaining the resilience and stability of the Earth system (safe ESBs) and minimizing exposure to significant harm to humans from Earth system change (a necessary but not sufficient condition for justice).

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Perspective: sustainability challenges, opportunities and solutions for long-term ecosystem observations.

Philos Trans R Soc Lond B Biol Sci

July 2023

Tomakomai Experimental Forest, Field Science Center for Northern Biosphere, Hokkaido University, Takaoka, Tomakomai, Hokkaido 053-0035, Japan.

As interest in natural capital grows and society increasingly recognizes the value of biodiversity, we must discuss how ecosystem observations to detect changes in biodiversity can be sustained through collaboration across regions and sectors. However, there are many barriers to establishing and sustaining large-scale, fine-resolution ecosystem observations. First, comprehensive monitoring data on both biodiversity and possible anthropogenic factors are lacking.

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Quantifying the direct and indirect effects of sika deer (Cervus nippon) on the prevalence of infection with Rickettsia in questing Haemaphysalis megaspinosa: A field experimental study.

Ticks Tick Borne Dis

September 2023

Graduate School of Frontier Sciences, The University of Tokyo, 5F Environmental Building, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan. Electronic address:

Sika deer (Cervus nippon) are important hosts for all life stages of Haemaphysalis megaspinosa, a suspected Rickettsia vector. Because some Rickettsia are unlikely to be amplified by deer in Japan, the presence of deer may decrease the prevalence of Rickettsia infection in questing H. megaspinosa.

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Orphan gene expressed in flame cone cells uniquely found in seahorse epithelium.

Cell Tissue Res

July 2023

Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Chiyoda-ku, Tokyo, Japan.

The seahorse is one of the most unique teleost fishes in its morphology. The body is surrounded by bony plates and spines, and the male fish possess a brooding organ, called the brood pouch, on their tail. The surfaces of the brood pouch and the spines are surrounded by characteristic so-called flame cone cells.

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Spatial and temporal distribution of reported dengue cases and hot spot identification in Quezon City, Philippines, 2010-2017.

Trop Med Health

May 2023

Department of Global Health, Graduate School of Health Sciences, University of the Ryukyus, 207 Uehara, Nishihara-Cho, Nakagami-Gun, Okinawa, 903-0215, Japan.

Background: Dengue remains a major public health problem in the Philippines, particularly in urban areas of the National Capital Region. Thematic mapping using geographic information systems complemented by spatial analysis such as cluster analysis and hot spot detection can provide useful information to guide preventive measures and control strategies against dengue. Hence, this study was aimed to describe the spatiotemporal distribution of dengue incidence and identify dengue hot spots by barangay using reported cases from Quezon City, the Philippines from 2010 to 2017.

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Response of resistant larvae of the coral Acropora tenuis to future thermal stress.

Mar Pollut Bull

July 2023

Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Okinawa, Japan. Electronic address:

Seawater temperatures are rising rapidly and severely due to climate change, negatively affecting coral reef communities. The persistence of coral populations depends on their success during the early life stages. Thermal conditioning during the larval stage can increase coral larvae's ability to tolerate high temperatures in subsequent stages.

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Dispersal is a crucial mechanism to living beings, allowing them to reach new resources such that populations and species can occupy new environments. However, directly observing the dispersal mechanisms of widespread species can be costly or even impractical, which is the case for mangrove trees. The influence of ocean currents on mangrove dispersal is increasingly evident; however, few studies mechanistically relate the patterns of population distribution with the dispersal by oceanic currents under an integrated framework.

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