Elevated Carbon Dioxide Levels Research Articles

Observational study of ground-level ozone and climatic factors in Craiova, Romania, based on one-year high-resolution data.

Air pollution is a multifaceted issue affecting people's health, environment, and biodiversity. Gaining comprehension of the interactions between natural and anthropocentric pollutant concentrations and local climate is challenging. This study aims to address the following two questions: (1) What is the influential mechanism of climatic and anthropogenic factors on the ground-level ozone (O3) concentrations in an urban environment during different seasons? (2) Can the ozone weekend effect be observed in a medium-sized city like Craiova, and under which conditions? In order to answer these questions, ozone interactions with meteorological parameters (temperature, pressure, relative humidity) and pollutant concentrations (particulate matter, carbon dioxide, volatile organic compounds, formaldehyde, nitrogen dioxide, nitric oxide and carbon monoxide) is evaluated based on a one-year dataset given by a low-cost sensor and one-year dataset provided by the National Environment Agency. Using two statistical analysis programs, Python and SPSS, a good understanding of the correlations between these variables and ozone concentration is obtained. The SPSS analysis underscores the significant impact of three meteorological factors and nine other pollutants on the ozone level. A positive correlation is noticed in the summer when sunlight is intense and photochemical reactions are elevated. The relationship between temperature and ozone concentration is strong and positive, as confirmed by Spearman's rho correlation coefficient (r = 0.880). A significant negative correlation is found between relative humidity and ozone (r = -0.590). Moreover, the analysis shows that particulate matter concentrations exhibit a significant negative correlation with ozone (r ≈ -0.542), indicating that higher particulate matter concentrations reduce ozone levels. Volatile organic compounds show a significant negative correlation with ozone (r = -0.156). A negative relationship between ozone and carbon dioxide (r = -0.343), indicates that elevated carbon dioxide levels might also suppress ozone concentrations. A significant positive correlation between nitrogen dioxide and ozone (r = 0.060), highlights the role of nitrogen dioxide in the production of ozone through photochemical reactions. However, nitric oxide shows a negative correlation with ozone (r = -0.055) due to its role in ozone formation. Carbon monoxide has no statistically significant effect on ozone concentration. To observe the differences between weekdays and weekends, T-Test was used. Even though significant differences were observed in temperature, humidity, carbon dioxide, volatile organic compounds, nitrogen dioxide, nitric oxide and carbon monoxide levels between weekdays and weekends, the T-Test did not highlight a significant weekend ozone effect in a mid-sized city as Craiova. Using Python, the daily values were calculated and compared with the limit values recommended by the World Health Organization (WHO) and European Environment Agency (EEA). The WHO O3 recommended levels were exceeded for 13 times in one year. This study offers a comprehensive understanding of ozone pollution in a mid-sized city as Craiova, serving as a valuable reference for local decision-makers. It provides critical insights into the seasonal dynamics of ozone levels, emphasizing the significant role of temperature in ozone formation and the complex interactions between various pollutants and meteorological factors.

Skill building in freediving as an example of embodied culture.

Skilled activity is a complex mix of automatized action, changed attention patterns, cognitive strategies and physiological adaptations developed within a community of practice. Drawing on physiological and ethnographic research on freediving, this article argues that skill acquisition demonstrates the variety of mechanisms that link biological and cultural processes to produce culturally shaped forms of embodiment. In particular, apneists alter phenotypic expression through patterned practices that canalize development, exaggerating the dive response, developing resistance to elevated carbon dioxide levels (hypercapnia) and accommodating hydrostatic pressure at depth. The community of divers provides technical advice and helps to orient individuals' motivations. Some biological processes are phenomenologically accessible, but others are sub-aware and must be accessed indirectly through behaviour or altered interactions with the environment. The close analysis of embodied skills like freediving illustrates how phenotypic plasticity is inflected by culturally patterned behaviours. Divers do developmental work on bodily traits like the dive response to achieve more dramatic performance, even if they cannot directly control all elements of the neurological and physiological responses. The example of expert freediving illustrates the imbrication of biology and culture in embodiment. This article is part of the theme issue 'Minds in movement: embodied cognition in the age of artificial intelligence'.

Spatiotemporal evolution of air-sea CO2 flux in the Northwest Pacific and its response to ENSO

Global warming, driven by human activities since the Industrial Revolution, has significantly elevated atmospheric carbon dioxide (CO2) levels, leading to higher global temperatures and a rise in extreme weather events. The ocean, as a major carbon sink, has absorbed about 30% of human-induced carbon emissions, helping mitigate global warming’s impacts. This study examines the spatiotemporal distribution of air-sea CO2 flux in the Northwest Pacific from 1982 to 2021 and its response to El Niño-Southern Oscillation, using Empirical Orthogonal Function and composite analysis. The seasonal patterns of air-sea CO2 flux and the influence of environmental factors were further evaluated. The results show that air-sea CO2 flux in the Northwest Pacific exhibits clear seasonal fluctuations. In winter, high-latitude areas act as significant carbon sources. Strong winds deepen the mixed layer, promoting CO2 release from the ocean into the atmosphere. In contrast, in summer, longer daylight hours, rising SST, and melting sea ice lead to upwelling, which brings nutrients to the surface and stimulates phytoplankton growth. This process turns the region into a carbon sink as phytoplankton growth, driven by intense sunlight, enhances the ocean’s CO2 absorption. The mid-latitude region consistently acts as a carbon sink year-round. During El Niño events, more negative air-sea CO2 flux anomalies appear in the eastern Northwest Pacific, enhancing carbon uptake. La Niña events have the opposite effect in the eastern regions. These findings highlight the Northwest Pacific’s critical role in modulating regional and global carbon cycles under varying climatic conditions. Understanding these dynamics is crucial for improving predictions of future climate impacts and for developing effective strategies to mitigate global warming.

Evaluation of Elevated CO2 on Nutritional Quality of Green Gram for the Management of Callosobruchus chinensis (L.) during Storage

An experiment was conducted to study the assessment of nutritional quality parameters of green gram treated with elevated levels of carbon dioxide to manage Callosobruchus infestation during 2020-21 at Seed Entomology Laboratory, Seed Research and Technology Centre, College of Agriculture, Rajendranagar, Hyderabad, India. Nutritional quality of Callosobruchus chinensis infested green gram seeds exposed to four different concentrations of CO2 viz., 20, 40, 60 and 80 per cent was studied. The results revealed that the 80 per cent CO2 concentration maintained high carbohydrate content (62.93 per cent) and crude fat (4.51 per cent) besides less protein (25.26 per cent) content after two months of storage. The 80per cent CO2 treatment was consistently found to be the best treatment when it was retested in bulk quantity (25 kg of seed) after two months of storage period. High carbohydrate, crude fat content and low protein content were observed in all the CO2 treatments (20, 40, 60 and 80 per cent) when compared to untreated control. These findings suggest that using elevated CO2 levels could be a viable alternative to synthetic pesticides chemical fumigants for preserving green gram during storage.

Impact Of Inhalational Anesthetics On Respiratory System

Inhalational anaesthetics, commonly used in general anaesthesia, profoundly impact respiratory function and lung mechanics. These agents depress the central nervous system, including the respiratory centres in the brainstem, leading to reduced breathing rate and depth. This suppression results in diminished tidal volume, reduced inspiratory and expiratory reserve volumes, and potentially decreased functional residual capacity. The central nervous system depression also weakens airway reflexes such as coughing, gagging, and swallowing, increasing the risk of airway obstruction and aspiration. Additionally, inhalational anaesthetics can impair gas exchange, causing lower oxygen levels (hypoxemia) and elevated carbon dioxide levels (hypercapnia). Respiratory complications during surgery may include hypoxia, bronchospasm, and impaired ventilation, especially in patients with pre-existing respiratory conditions. To manage these risks, continuous monitoring of respiratory parameters, preoperative assessment, and effective airway management are crucial. This paper reviews the effects of inhalational anaesthetics on respiratory function and outlines strategies for minimising associated risks during surgical procedures

Stoichiometric theory in aquatic carbon sequestration under elevated carbon dioxide

Global climate change projections indicate that the atmospheric concentration of carbon dioxide will increase twofold by the end of this century. However, how the elevated carbon dioxide affects aquatic carbon sequestration and species composition within aquatic microbial communities remains inconclusive. To address this knowledge gap, we formulate a bacteria-algae interaction model to characterize the effects of elevated carbon dioxide on aquatic ecosystems and rigorously derive the thresholds determining the persistence and extinction of algae or bacteria. We explore the impacts of abiotic factors, such as light intensity, nutrient concentration, inorganic carbon concentration and water depth, on algae and bacteria dynamics. The main findings indicate that the elevated atmospheric carbon dioxide will increase algae biomass and thus facilitate carbon sequestration. On the other hand, the elevated atmospheric carbon dioxide will reduce bacterial biomass, and excessive carbon dioxide concentrations can even destroy bacterial communities. Numerical simulations indicate that eutrophication and intensified light intensity can reduce aquatic carbon sequestration, while elevated atmospheric carbon dioxide levels can mitigate eutrophication. Furthermore, higher algae respiration and death rates are detrimental to carbon sequestration, whereas the increased bacterial respiration rates promote carbon sequestration.

Identification of genes used by Escherichia coli to mitigate climatic stress conditions

IntroductionIncreasing temperature and elevated atmospheric carbon dioxide levels could impact the survival of stress-adapted bacteria. Method and resultsIn this study, RNA sequencing was performed to quantify Escherichia coli BL21 (DE3) gene expression in culture media under environmental temperature (27 °C and 42 °C) and carbon dioxide (0.2 % and 6 % v/v) conditions. Differential gene expression analysis between low temperature and different carbon dioxide conditions revealed up-regulated genes such as ldtC and bioA, optimising cell wall integrity and nutrient uptake. While, the downregulation of genes such as malK suggested a metabolic adaptation. Low temperature and high carbon dioxide levels enhanced bacterial tolerance to environmental stress. Under optimal temperatures, Escherichia coli adapts through various metabolic pathways while engaging in different processes at low temperatures and carbon dioxide levels, with temperature having a greater impact on gene expression than carbon dioxide levels. This study shows that complex metabolic activities are activated when both temperatures and carbon dioxide levels are combinsed, affecting antimicrobial resistance, nutrient acquisition, and adaptation strategies. ConclusionEach condition exhibited mechanisms to enhance cellular resilience and adaptation to stress, focusing on cellular integrity, optimising energy utilisation, and activating stress response pathways. Impact statementThe findings stress the importance of continued research to understand the implications of climate change on microbial transcriptomes comprehensively.

Influence of multi-stressor combinations of pCO2, temperature, and salinity on the toxicity of Heterosigma akashiwo (Raphidophyceae), a fish-killing flagellate.

Climate change and global warming have led to more frequent harmful algal blooms in the last decade. Among these blooms, Heterosigma akashiwo, a golden-brown phytoflagellate, is one of the 40 species with a high potential to form harmful blooms, leading to significant fish mortality. Climate change leads to rising atmospheric and ocean temperatures. These changes, along with altered rainfall patterns and meltwater input, can cause fluctuations in ocean salinity. Elevated atmospheric carbon dioxide (CO2) levels increase water acidity as oceans absorb CO2. This study investigated the effects of temperature, salinity, and CO2 levels on lipid production, hemolytic activity, and toxicity of H. akashiwo using the design of experiment approach, which can be used to investigate the effect of two or more factors on the same response simultaneously in a precise manner with fewer experiments and materials but in a larger region of the factor space. The lipid content was measured using a high-throughput Nile Red method, and the highest level of lipid content was detected at 25°C, a salinity of 30, and a CO2 concentration of 400 ppm. Hemolytic activity was assessed using rabbit blood erythrocytes in a 96-well plate, and the optimal conditions for achieving the highest hemolytic activity were determined at 15°C, a salinity of 10, and a CO2 concentration of 400 ppm. As the chemical structure of the toxin is not known, we used the toxicity against the cell line RTgill-W1 as the cell toxicity proxy. The maximum toxicity was identified at 15°C, a salinity of 10, and a CO2 level of 700 ppm.

Impacts of Climate change on soil microbial diversity, distribution and abundance

Climate change, driven by anthropogenic activities, has far-reaching consequences for our planet. Among its many impacts, changes in temperature, elevated carbon dioxide levels, and shifts in greenhouse gas concentrations significantly affect soil ecosystems. In particular, soil microbial communities play a pivotal role in nutrient cycling, organic matter decomposition, and overall soil health. Soil microbial communities respond differently to the effects of climate change, like elevated warming and precipitation. The change in climatic conditions is reported to be adversely affecting soil biological activity directly through either drying or wetting of soil or affecting their associated plants. This review delves into the intricate relationship between climate change and soil microbial abundance, diversity, and distribution. The paper also discusses climatic change pressure on soil enzymatic activity and microbial biomasses, as well as soil faunal activity, as they are key indicators of soil health in a changing climate. Soil microbial communities cope with climate change by changing their diversity and physiological characteristics and by changing their symbiotic plants, which indicates the role of soil microbes in withstanding the negative impact of climate change.

ASSESSMENT OF CO2 EMISSION DUE TO SPEED BUMPS ON SELECTED HIGHWAYS IN BAUCHI STATE

One industry that will emit carbon dioxide (CO2) that is dependent on the production of fossil fuels is transportation. Even though cars emit carbon dioxide (CO2), which contributes to air pollution, fossil fuel-powered vehicles nevertheless require widespread use. Traffic-calming devices act as tools to reduce the rapidity of automobiles. They make a major contribution to road protection; however, air contamination is more likely to arise due to the fact that motor vehicles use brakes and accelerate more regularly. This study examines the impact of speed bumps brought on by elevated carbon dioxide (CO2) levels on selected commercial vehicles, including Vectra, Volkswagon, Peugeot, Ford Galaxy, and Toyota Hiace buses, traveling on highways from Bauchi to Jos, Bauchi to Azare, Bauchi to Gombe, and Bauchi to Kano. To estimate the CO2 emissions of each kind of specified commercial vehicle, the fuel consumption of the vehicles before and after the installation of bumps was gathered using a questionnaire model and examined using a mathematical model using a macro-scale approach. The result shows that there is an increase of 21% in CO2 emissions on the Bauchi to Jos Highway, 15% in CO2 emissions on Bauchi to Azare, 24% in CO2 emissions on Bauchi to Gombe, and 40% in CO2 emissions on Bauchi to Kano. The study concludes that transport-related pollution on Bauchi Highway has indeed significantly increased with the installation of calming traffic devices, which is dangerous to human health and vegetation near these highways.

Global warming’s grip on agriculture: Strategies for sustainable production amidst climate change using regression based prediction

The intersection of climate change and food production is emerging as a critical area of research, focusing on both the potential benefits and the significant challenges posed by changing climate conditions. Elevated levels of carbon dioxide alongside rising global temperatures could theoretically boost crop yields, benefiting both human and animal consumption. This study examines the impact of various climate variables—temperature, humidity, precipitation, and soil moisture—on the primary production of essential foods such as rice, wheat, livestock, milk, eggs, vegetables, and fruits. Utilizing data from different countries spanning from 2000 to 2020, drawn from world development indicators, this research employs econometric analysis coupled with deep learning-based cluster analysis. Additionally, it projects future production trends up to 2100 using the moving average time series forecasting method. The findings reveal a direct correlation between climate variables and the production levels of vegetables and other food items, highlighting the immediate effects of climatic changes on agriculture. The study also points out the uneven distribution of these climate impacts, with developing countries facing more severe challenges due to their limited resources and adaptive capacities. This uneven impact contributes to increased uncertainty in food supply and affects market stability. Furthermore, concerns about food safety are intensifying under the influence of climate change, although some regions have implemented effective food conservation and control measures to mitigate these risks. This research underscores a complex landscape where the risks and benefits of climate change on food production are not uniformly distributed, but rather are influenced by a myriad of factors including geographic location, economic conditions, and the level of technological advancement in food safety practices. The nuanced understanding of these dynamics is crucial for developing targeted strategies to enhance food security in the face of a changing climate.

Effectiveness of corticosteroids and epinephrine use in neonates for the first extubation attempt: A retrospective study

BackgroundThis study aimed to analyze the use of corticosteroids and epinephrine in neonates for the first extubation attempt and compared clinical characteristics of infants with successful and failed extubation events. MethodsThis was a retrospective cohort study conducted at a single level III neonatal intensive care unit in Taiwan. The study included 215 infants born between 2020 and 2021 who had been intubated for more than 48 h before their first extubation attempt. We compared perinatal and peri-extubation characteristics and outcomes between the two groups. Successful extubation was defined as freedom from invasive ventilatory support 72 h after extubation. The relationship between corticosteroids, local epinephrine, and successful extubation was determined using multivariate logistic regression analysis. ResultsIn the univariate analysis, the failed extubation group received a significantly higher proportion of intravenous dexamethasone (p = 0.006) than the successful extubation group. Furthermore, the failed extubation group had a longer duration of nebulized epinephrine (p = 0.034) and more episodes of local application of epinephrine to the superior larynx (p = 0.003) than the successful extubation group. Multivariate analysis revealed that the absence of lung atelectasis, tachycardia 72 h after extubation, and lower post-extubation PCO2 were the key factors associated with successful extubation. ConclusionsThere were trends toward systemic dexamethasone, local application of epinephrine to the superior larynx, and longer duration of nebulized epinephrine in the reintubation group. However, corticosteroid or local epinephrine use was not significantly associated with successful extubation. Lung atelectasis, elevated levels of carbon dioxide, and tachycardia were identified as risk factors for extubation failure.

Primary Metabolic Response of Aristolochia contorta to Simulated Specialist Herbivory under Elevated CO2 Conditions.

This study explores how elevated carbon dioxide (CO2) levels affects the growth and defense mechanisms of plants. We focused on Aristolochia contorta Bunge (Aristolochiaceae), a wild plant that exhibits growth reduction under elevated CO2 in the previous study. The plant has Sericinus montela Gray (Papilionidae) as a specialist herbivore. By analyzing primary metabolites, understanding both the growth and defense response of plants to herbivory under elevated CO2 conditions is possible. The experiment was conducted across four groups, combining two CO2 concentration conditions (ambient CO2 and elevated CO2) with two herbivory conditions (herbivory treated and untreated). Although many plants exhibit increased growth under elevated CO2 levels, A. contorta exhibited reduced growth with lower height, dry weight, and total leaf area. Under herbivory, A. contorta triggered both localized and systemic responses. More primary metabolites exhibited significant differences due to herbivory treatment in systemic tissue than local leaves that herbivory was directly treated. Herbivory under elevated CO2 level triggered more significant responses in primary metabolites (17 metabolites) than herbivory under ambient CO2 conditions (five metabolites). Several defense-related metabolites exhibited higher concentrations in the roots and lower concentrations in the leaves in response to the herbivory treatment in the elevated CO2 group. This suggests a potential intensification of defensive responses in the underground parts of the plant under elevated CO2 levels. Our findings underscore the importance of considering both abiotic and biotic factors in understanding plant responses to environmental changes. The adaptive strategies of A. contorta suggest a complex response mechanism to elevated CO2 and herbivory pressures.

Modeling Climate Change Scenarios for Spring Barley in Southeast of Almaty in Kazakhstan Using the LINTUL Approach

Barley stands as a cornerstone in agricultural landscape of Kazakhstan, weaving through diverse climate zones, and annually gracing over 1.5 million hectares. The intricate interplay between climate and food systems necessitates thorough analysis and strategic measures to food safety and nutritional security, as the evolving climate significantly influences both the quantity and quality of our food resources. This study aims to employ the LINTUL-MULTICROP Model to assess how spring barley adapts to both today’s climatic conditions and potential climate change scenarios to elevated levels of carbon dioxide and temperature under the specific conditions of southeast of Almaty. Three different global climate change models were studied (GCMs); i) GFDL-ESM2M, ii) HadGEM2-AO, and iii) MPI-ESM-MR for historical period (1986-2005) under RCP 4.5 and RCP 8.5 during the periods of i) 2040-2059 years scenarios, ii) 2060-2079 years scenarios, and iii) 2080-2099 years scenarios. Overall, the HADGEMAO and MPIESMMR models exhibited promising results in simulating yield, projecting an increase in spring barley yield for both RCP4.5 and RCP8.5 scenarios in GFDL-ESM2M model case also demonstrated stable increase in rainfed conditions. In conclusion, it should be noted that in the conditions of Kazakhstan, the cultivation of spring barley tends to change to growth in the southeast of Almaty.

Elevated Ambient Carbon Dioxide Levels Induce Attraction but Not Attachment of Adult Ixodes scapularis in Artificial Membrane Feeding

Numerous feeding studies on tick species have explored disease transmission, vector interactions, and acaricide testing. Traditionally, these studies used animals for feeding. However, artificial membrane feeding offers several advantages including increased standardization of experiments, decreased costs, and improved animal welfare. In vitro conditions must closely mimic natural environments to promote successful feeding attachment. Kairomones produced by the host are strong stimulants that encourage attachment. An important kairomone detected by ticks is carbon dioxide (CO2). Previous studies have shown elevated CO2 levels stimulate host identification and attraction and potentially improve artificial feeding rates in some tick species. The objective of this study was to use an artificial membrane feeding chamber prototype to explore the effects of ambient CO2 in inducing Ixodes scapularis attachment. Differences in attachment rate were explored at an air-typical ambient CO2 level of 0.04% and an elevated CO2 level of 4.0%. Tick attachment was not detected in either ambient CO2 condition during the incubation period, indicating ambient CO2 does not impact the attachment rate under the presented condition. However, I. scapularis contact with the artificial membrane occurred at an increased rate of 0.014 female ticks in contact with the membrane per hour in the elevated CO2 condition (4%) compared with a rate of 0.01 ticks per hour in the air-typical CO2 condition (0.04%) (p = 0.048) suggesting that the ambient CO2 level affects attraction to the blood but does not directly stimulate attachment of I. scapularis.

Photothermal-driven CO2 reduction over Nd2O3/TiO2 heterojunction catalysts in aqueous medium

Elevated carbon dioxide levels, a major environmental concern, pose challenges for causing many climate problems. Addressing this, conversion CO2 into valuable chemicals is highly important. In this work, we explore photothermal catalytic CO2 reduction, an attractive approach that combines photocatalysis and thermal catalysis. We developed an enhanced Nd2O3/TiO2 catalyst using the sol-gel method, which significantly improves the efficiency of converting CO2 to CO in the presence of water. This catalyst exhibited a CO production rate of 22 μmol·gcat−1·h−1 at 130 °C, markedly surpassing the performance of sole photocatalysis by 7.3 times. Through systematic characterizations, we discovered that Nd2O3 prevents TiO2’s transition from anatase to rutile, thereby increasing CO2 adsorption and creating more vacancies. The interface between Nd2O3 and TiO2 forms a Z-scheme heterojunction, crucial for the simultaneous reduction of CO2 and oxidation of water. This research introduces a promising catalyst for photothermal CO2 reduction, which also acts as a reducing reagent. The strategic engineering of dual metal oxide interfaces in this catalyst suggests its applicability in a range of photothermal catalytic processes, marking a significant advancement in the field of CO2 utilization.

Unraveling the Complexities of Oxidative Stress and Inflammation Biomarkers in Obstructive Sleep Apnea Syndrome: A Comprehensive Review.

Obstructive sleep apnea syndrome (OSAS), affecting approximately 1 billion adults globally, is characterized by recurrent airway obstruction during sleep, leading to oxygen desaturation, elevated carbon dioxide levels, and disrupted sleep architecture. OSAS significantly impacts quality of life and is associated with increased morbidity and mortality, particularly in the cardiovascular and cognitive domains. The cyclic pattern of intermittent hypoxia in OSAS triggers oxidative stress, contributing to cellular damage. This review explores the intricate relationship between OSAS and oxidative stress, shedding light on molecular mechanisms and potential therapeutic interventions. A comprehensive review spanning from 2000 to 2023 was conducted using the PubMed, Cochrane, and EMBASE databases. Inclusion criteria encompassed English articles focusing on adults or animals and reporting values for oxidative stress and inflammation biomarkers. The review delineates the imbalance between pro-inflammatory and anti-inflammatory factors in OSAS, leading to heightened oxidative stress. Reactive oxygen species biomarkers, nitric oxide, inflammatory cytokines, endothelial dysfunction, and antioxidant defense mechanisms are explored in the context of OSAS. OSAS-related complications include cardiovascular disorders, neurological impairments, metabolic dysfunction, and a potential link to cancer. This review emphasizes the potential of antioxidant therapy as a complementary treatment strategy. Understanding the molecular intricacies of oxidative stress in OSAS is crucial for developing targeted therapeutic interventions. The comprehensive analysis of biomarkers provides insights into the complex interplay between OSAS and systemic complications, offering avenues for future research and therapeutic advancements in this multifaceted sleep disorder.

Effects of unilateral superimposed high-frequency jet ventilation on porcine hemodynamics and gas exchange during one-lung flooding.

Superimposed high-frequency jet ventilation (SHFJV) is suitable for respiratory motion reduction and essential for effective lung tumor ablation. Fluid filling of the target lung wing one-lung flooding (OLF) is necessary for therapeutic ultrasound applications. However, whether unilateral SHFJV allows adequate hemodynamics and gas exchange is unclear. To compared SHFJV with pressure-controlled ventilation (PCV) during OLF by assessing hemodynamics and gas exchange in different animal positions. SHFJV or PCV was used alternatingly to ventilate the non-flooded lungs of the 12 anesthetized pigs during OLF. The animal positions were changed from left lateral position to supine position (SP) to right lateral position (RLP) every 30 min. In each position, ventilation was maintained for 15 min in both modalities. Hemodynamic variables and arterial blood gas levels were repeatedly measured. Unilateral SHFJV led to lower carbon dioxide removal than PCV without abnormally elevated carbon dioxide levels. SHFJV slightly decreased oxygenation in SP and RLP compared with PCV; the lowest values of PaO2 and PaO2/FiO2 ratio were found in SP [13.0; interquartile range (IQR): 12.6-5.6 and 32.5 (IQR: 31.5-38.9) kPa]. Conversely, during SHFJV, the shunt fraction was higher in all animal positions (highest in the RLP: 0.30). In porcine model, unilateral SHFJV may provide adequate ventilation in different animal positions during OLF. Lower oxygenation and CO2 removal rates compared to PCV did not lead to hypoxia or hypercapnia. SHFJV can be safely used for lung tumor ablation to minimize ventilation-induced lung motion.

A laboratory study of the increasing competitiveness of Karenia mikimotoi under rising CO2 scenario

Ocean acidification (OA) driven by elevated carbon dioxide (CO2) levels is expected to disturb marine ecological processes, including the formation and control of harmful algal blooms (HABs). In this study, the effects of rising CO2 on the allelopathic effects of macroalgae Ulva pertusa to a toxic dinoflagellate Karenia mikimotoi were investigated. It was found that high level of CO2 (1000 ppmv) promoted the competitive growth of K. mikimotoi compared to the group of present ambient CO2 level (420ppmv), with the number of algal cell increased from 32.2 × 104 cells/mL to 36.75 × 104 cells/mL after 96 h mono-culture. Additionally, rising CO2 level weakened allelopathic effects of U. pertusa on K. mikimotoi, as demonstrated by the decreased inhibition rate (50.6 % under the original condition VS 34.3 % under the acidified condition after 96 h co-culture) and the decreased reactive oxygen species (ROS) level, malondialdehyde (MDA) content, antioxidant enzymes activity (superoxide dismutase (SOD), peroxidase (POD), glutathione peroxidase (GPX), glutathione reductase (GR) and catalase (CAT) and non-enzymatic antioxidants (glutathione (GSH) and ascorbic acid (ascorbate, vitamin C). Indicators for cell apoptosis of K. mikimotoi including decreased caspase-3 and -9 protease activity were observed when the co-cultured systems were under rising CO2 exposure. Furthermore, high CO2 level disturbed fatty acid synthesis in U. pertusa and significantly decreased the contents of fatty acids with allelopathy, resulting in the allelopathy weakening of U. pertusa. Collectively, rising CO2 level promoted the growth of K. mikimotoi and weakened allelopathic effects of U. pertusa on K. mikimotoi, indicating the increased difficulties in controlling K. mikimotoi using macroalgae in the future.

Optimisasi Budidaya Rumput Laut sebagai Benteng Alami untuk Mengurangi Asidifikasi Laut

Anthropogenic carbon dioxide emissions are propelling a concerning rise in ocean acidity, posing severe threats to marine ecosystems, especially calcifying organisms like corals and mollusks. In response to this global challenge, seaweed farming has emerged as a promising remedy. Leveraging their remarkable growth rates and carbon sequestration abilities, seaweeds offer a viable solution to counteract the acidifying effects of elevated carbon dioxide levels in the oceans. Through photosynthesis, seaweeds actively absorb carbon dioxide from seawater, thereby mitigating acidity and fostering improved water quality. The potential of seaweed farms extends beyond mere carbon sequestration. These farms play a pivotal role in habitat creation, absorb nitrogen and phosphorus nutrients, and contribute to enhanced biodiversity. The cultivation of seaweed not only addresses the immediate concern of ocean acidification but also provides a holistic ecological approach with far-reaching benefits. As a sustainable and scalable strategy, seaweed farming exemplifies an innovative and multifaceted solution to the complex challenges posed by anthropogenic impacts on the oceans, underlining the importance of nature-based interventions in preserving the health and balance of marine ecosystems.