Short-term dynamics of fecal microbiome and antibiotic resistance in juvenile rainbow trout (Oncorhynchus mykiss) following antibiotic treatment and withdrawal.

Background: In aquaculture, the secretions of cultured organisms contribute to the development of aquatic antibiotic resistance. However, the antibiotic-induced changes in fish feces remain poorly understood. This study aimed to assess the short-term dynamics of fecal microbiome and antibiotic resistance in juvenile rainbow trout (Oncorhynchus mykiss) upon antibiotic treatment and withdrawal period.

Early-Branching Cyanobacteria Grow Faster and Upregulate Superoxide Dismutase Activity Under a Simulated Early Earth Anoxic Atmosphere.

The evolution of oxygenic photosynthesis during the Archean (4-2.5 Ga) required the presence of complementary reducing pathways to maintain the cellular redox balance. While the timing of the evolution of superoxide dismutases (SODs), enzymes that convert superoxide to hydrogen peroxide and O, within bacteria and archaea is not resolved, the first SODs appearing in cyanobacteria contained copper and zinc in the reaction center (CuZnSOD).

Nitrogen availability in soil controls uptake of different nitrogen forms by plants.

Nitrogen (N) uptake by plant roots from soil is the largest flux within the terrestrial N cycle. Despite its significance, a comprehensive analysis of plant uptake for inorganic and organic N forms across grasslands is lacking. Here we measured in situ plant uptake of 13 inorganic and organic N forms by dominant species along a 3000 km transect spanning temperate and alpine grasslands.

Spatial variations of ascidian diets in a glacial retreated fjord of the West Antarctic Peninsula.

The impacts of glacial retreat on diets of ascidians, one of the filter feeders and a major component of the benthic-pelagic energy pathway, remain unclear. We analyzed carbon and nitrogen stable isotopes of four dominant ascidian species and five potential food sources in Marian Cove, a deglaciating fjord in West Antarctica. Microphytobenthos was a major food source for ascidians regardless of proximity to the glacier, but phytoplankton contribution decreased closer to the glacier.

Evaluating radionuclide mobility in groundwater recharge areas of fractured natural barrier systems using multiple isotopes and microbial indicators.

The distribution of uranium (U) concentrations, which reached up to 322 µg/L, was found to correlate with the pattern of fractures within the natural barrier system (NBS). Analysis of the vertical distribution of dissolved oxygen (DO), dissolved organic carbon (DOC), tritium (H), microbial communities, and HO and SO isotopes revealed insights into oxic water infiltration within the heterogeneous fractured system. Their distribution showed that the average infiltration depth at the KURT site is 200 m, while in external areas with a high frequency of fractures, oxic conditions extended down to 495 m.

Pervasive fire danger continued under a negative emission scenario.

Enhanced fire-prone weather under greenhouse gas warming can significantly affect local and global carbon budgets from increased fire occurrence, influencing carbon-climate feedbacks. However, the extent to which changes in fire-prone weather and associated carbon emissions can be mitigated by negative emissions remains uncertain. Here, we analyze fire weather responses in CO removal climate model experiments and estimate their potential carbon emissions based on an observational relationship between fire weather and fire-induced CO emissions.

A step-by-step procedure for analysing the 16S rRNA-based microbiome diversity using QIIME 2 and comprehensive PICRUSt2 illustration for functional prediction.

Short-read sequencing technology has emerged as a preferred tool to analyse the bacterial composition of a niche by targeting hypervariable regions of the 16S rRNA gene. It targets the short hypervariable regions of the 16S rRNA gene and uncovers the taxonomic profile and their associated pathways. QIIME 2 is preferred and ready-to-use pipelines that perform stepwise analysis of massive short reads of 16S rRNA genes.

Selective transmission of airborne bacterial communities from the ocean to the atmosphere over the Northern Pacific Ocean.

This study simultaneously measured the taxonomic diversity of bacterial communities in both seawater and PM aerosol samples collected from the Northern Pacific Ocean during a cruise covering 7724 km between 37°N 126°E and 58°N 179°E. The relative abundance of Proteobacteria, Cyanobacteria, and Firmicutes were found to be more prevalent in aerosol samples (39 ± 16 %, 5.1 ± 1.

Iron Impurity Impairs the CO Capture Performance of MgO: Insights from Microscopy and Machine Learning Molecular Dynamics.

Magnesium oxide (MgO) is a promising sorbent for direct air capture (DAC) of carbon dioxide. Iron (Fe) is a common impurity in naturally occurring MgO and minerals used to produce MgO, yet a molecular-scale understanding of Fe-doping effects on carbonation is lacking. Here, we observed reduced carbonation performance in Fe-doped MgO experimentally.

Revisiting the mid-Pleistocene transition ocean circulation crisis.

The mid-Pleistocene transition (MPT) [~1.25 to 0.85 million years ago (Ma)] marks a shift in the character of glacial-interglacial climate (, ).

How (Eco)immunology can augment global EcoHealth programmes: opportunities, needs, and challenges.

Graphical Abstract.

Quantitative analysis of winter PM reduction in South Korea, 2019/20 to 2021/22: Contributions of meteorology and emissions.

To quantitatively analyze the factors contributing to the change in winter PM concentrations in South Korea over the past three years (2019/20 to 2021/22), we used updated anthropogenic emissions, a nested version of the GEOS-Chem model, and ground-based observational data. Our study identified meteorological variability and changes in anthropogenic emissions from China and South Korea as the main factors influencing changes in PM concentrations. The model results showed low normalized mean biases (NMBs) (13 % to 25 % for China, -5 % to -1 % for South Korea) compared with the seasonal mean ground observations in winter, indicating the model's reliability.

Prediction of cytotoxicity of polycyclic aromatic hydrocarbons from first principles.

Ligand-specific binding interactions of xenobiotics with receptor proteins form the basis of cytotoxicity-based hazard assessment. Computational approaches enable predictive hazard assessment for a large number of chemicals in a high-throughput manner, minimizing the use of animal testing. However, in silico models for predicting mechanisms of toxic actions and potencies are difficult to develop because toxicity datasets or comprehensive understanding of the complicated kinetic process of ligand-receptor interactions are needed for model development.

Environmental fate and transformation mechanisms of chlorinated organic pollutants from the petrochemical industry: Insights for pollution control and remediation.

Chlorinated organic pollutants (Cl-OPs), highly toxic and environmentally persistent, have become the spotlight, particularly from petrochemical industry. This study focuses on environmental fate of Cl-OPs from petrochemical industry, and transformation mechanisms in multi-media, aiming to enhance pollution control and remediation strategies. Emitted from leakage and waste discharge, Cl-OPs, encompassing chlorinated volatile organic compounds (Cl-VOCs), traditional and emerging persistent organic pollutants (POPs), were prevalent with average concentrations of 10-10 μg/m in the atmosphere, 10-10 μg/kg in soil and 10-10 μg/L in groundwater.

Triple-oxygen isotopes of stony micrometeorites by secondary ion mass spectrometry (SIMS): Olivine, basaltic glass and iron oxide matrix effects for sensitive high-mass resolution ion microprobe-stable isotope (SHRIMP-SI).

Rationale: Micrometeorites are extraterrestrial particles smaller than ~2 mm in diameter, most of which melted during atmospheric entry and crystallised or quenched to form 'cosmic spherules'. Their parentage among meteorite groups can be inferred from triple-oxygen isotope compositions, for example, by secondary ion mass spectrometry (SIMS). This method uses sample efficiently, preserving spherules for other investigations.

Thoron, radon and microbial community as supportive indicators of seismic activity in groundwater.

Earthquakes have a significant impact on groundwater environments as well as human life. However, identifying active and affected zones from seismic events using isotopic and microbial diversity indicators remains a challenging frontier. To validate the applicability of this coupled method for real-time analysis, we analyzed thoron (Rn), radon (Rn), microbial community compositions, and hydrochemistry in groundwater samples during the 2017 Pohang earthquake for the first time.

Nonlinear changes in urban heat island intensity, urban breeze intensity, and urban air pollutant concentration with roof albedo.

This study systematically examines how the urban heat island (UHI) and urban breeze circulation (UBC) respond to an increase in roof albedo (α) and its influence on urban air pollutant dispersion. For this, idealized ensemble simulations are performed using the Weather Research and Forecasting (WRF) model. The increase in α from 0.

Highly potent and selective PPARδ agonist reverses memory deficits in mouse models of Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disease accompanied by neurotoxicity, excessive inflammation, and cognitive impairment. The peroxisome proliferator-activated receptor (PPAR) δ is a potential target for AD. However, its regulatory mechanisms and therapeutic potential in AD remain unclear.

Microplastics pollution in the marine environment: A review of sources, impacts and mitigation.

Over the past few years, microplastics (MPs) pollution in the marine environment has emerged as a significant environmental concern. Poor management practices lead to millions of tons of plastic waste entering oceans annually, primarily from land-based sources like mismanaged waste, urban runoff, and industrial activities. MPs pollution in marine environments poses a significant threat to ecosystems and human health, as it adsorbs pollutants, heavy metals, and leaches additives such as plasticizers and flame retardants, thus contributing to chemical pollution.