Oxidation of hydrofluoroolefins (HFOs) is a source of trifluoroacetic acid (TFA) in the lower atmosphere. TFA is deposited in precipitation and accumulates in water bodies and at land surfaces and...

Hydrochemical characteristics, evolution, and controlling factors of a karstic river with reservoirs: Insights from spatial-temporal analysis.

Echium species, abundant in the Canary Islands, contain unique fatty acids (FA) such as stearidonic acid (SDA; 18:4n-3) and γ-linolenic acid (GLA; 18:3n-6), which may improve egg quality while valorizing local genetic resources. This study evaluated the effects of Echium plantaegineum oil (EO) compared with linseed oil (LO) and soybean oil (SO) on productive performance, egg quality, sensory traits, and yolk fatty acid profile. Forty-eight hens from the Canary Islands were fed for 31 days with diets supplemented with 1.25% SO (SO-d), 1.1% LO + 0.15% beef tallow (LO-d), and 1% EO + 0.25% LO (EO-d). LO supplementation reduced laying rate and egg mass with respect to SO, increasing feed conversion ratio (FCR), whereas EO produced slightly lighter eggs compared to the SO group but with normal yolk proportion and shell traits. EO markedly increased egg yolk deposition of SDA, eicosapentaenoic acid (EPA; 20:5n-3), docosapentaenoic acid (n-3 DPA; 22:5n-3), and docosahexaenoic acid (DHA; 22:6n-3), while lowering the n-6/n-3 ratio and thrombogenic index (TI). No differences were observed in the evaluated sensory attributes among treatments. In conclusion, dietary inclusion of EO effectively enriches eggs with n-3 LC-PUFA without negatively affecting sensory quality, supporting its potential use as a functional ingredient in laying hen diets.

Homogentisic acid deposition within connective tissues causes ochronotic arthropathy, a rare musculoskeletal consequence of alkaptonuria that causes progressive degenerative changes in the joints. Significant impairment and unique intraoperative challenges during surgical management may result from advanced involvement of weight-bearing joints. We present the case of a 53-year-old adult who arrived with radiating hip and knee pain, stiffness, and limited mobility. The patient's history of dark urine prompted a biochemical analysis that showed high levels of homogentisic acid. It's interesting to note that there were no traditional outward signs of ochronosis, such as bluish-black scleral discolouration (Osler's sign) or auricular cartilage pigmentation. Both the hip and knee joints showed significant degenerative changes on radiographs. A phased surgical approach was chosen due to the advanced arthropathy, starting with bilateral total hip replacement and progressing to bilateral total knee replacement. Pathognomonic symptoms of ochronotic arthropathy, i.e. diffuse blackish-brown pigmentation of the articular cartilage and subchondral bone, were observed during surgery. Following surgery, the patient experienced a smooth recovery and reported long-lasting pain relief along with a return to his normal level of mobility and independence. The Harris Hip Score (HHS) increased from 31 to 93, and the Knee Society Score (KSS) increased from 40 to 93 at the 12-month follow-up, indicating a notable improvement in functional assessment. The current case of ochronotic arthropathy demonstrated pain relief and functional restoration after the staged bilateral total hip and knee arthroplasty. Despite the intraoperative challenges posed by pigmented and friable tissues, the use of common modern implants produced stable fixation and facilitated a smooth recovery for the patient.

The karst regions of northern Guangdong are the eastern extension of the southwestern karst regions in China. However, compared with the typical karst areas in Guangxi, Guizhou, and Yunnan provinces, the karst process and hydrochemical characteristics in this area have received less attention in scientific research. By collecting surface water and soil water samples, the Gibbs model, hydrochemical component relationship, ion ratio method, and positive matrix factorization（PMF）were used to deeply analyze the hydrochemical characteristics and influencing factors of the Niupanshi watershed in karst regions of northern Guangdong. Additionally, the influence and contribution of karstification on the hydrochemical characteristics of the watershed were quantitatively analyzed. The water in the Niupanshi watershed was mainly HCO3-Ca·Mg type, with a weakly acidic average pH of 6.68, in sharp contrast to the weakly alkaline characteristics of typical karst areas in southwestern China. Exogenous acids such as H2SO4 and HNO3 mainly entered the study area through atmospheric acid deposition and agricultural activities. The contribution rates of karstification to the hydrochemical characteristics of surface water and soil were 44.8% and 40.2%, respectively. The results showed that the hydrochemical characteristics of the Niupanshi watershed in karst regions of northern Guangdong were mainly affected by karstification, and exogenous acids significantly participated in the carbonate rock dissolution process in this area. These results not only enhance the understanding of the hydrogeological process in karst regions of northern Guangdong but also provide a new perspective for understanding the changes in the water environment in the karst area, which has important scientific significance for regional water resource management and ecological protection.

Over a century of large-scale mining and smelting in Sudbury (Ontario, Canada) has impacted nearby aquatic ecosystems. While considerable research exists on Sudbury-area lakes, few studies focus on lands important to Indigenous communities. Wolf Lake, located ~50 km northeast of Sudbury, acidified in the 1960s from long-range acidic deposition from regional smelters. While emission reductions ca. 1970s have been tracked through water chemistry monitoring, baseline conditions remain unknown. Using indicators preserved in lake sediments, we examined long-term effects of acidic emissions and other stressors on Wolf Lake’s aquatic biota. After peak atmospheric emissions, reconstructed lake water pH dropped to ~5.1, with concurrent decreases in sediment chlorophyll <i>a</i> (chl <i></i>a<i></i>) and dissolved organic carbon (DOC). These changes coincided with elevated sediment metal levels. Recent sediments show partial recovery, with pH, DOC, and chl a returning towards pre-disturbance levels. However, sediment metal levels remain high, and diatom assemblages have not fully recovered. Understanding these changes offers management insights for the Wahnapitae First Nation’s proposal for an Other Effective area-based Conservation Measure designation for Wolf Lake.

Fatty acid composition and gene regulatory network analysis of pectoral muscle in pigeons across developmental stages.

Nutrient losses from forest soils caused by decades of acid deposition have affected tree growth and depleted soils of essential nutrients in eastern North America. Non‐industrial wood ash (NIWA) is rich in macronutrients and may be a potential remediation strategy to restore lost nutrients as a forest soil amendment. We evaluated the effects of a single NIWA application on forest soils and Sugar maple ( Acer saccharum Marsh) foliage at three sugar bush stands in Muskoka, Ontario, Canada. Soil pH and calcium (Ca) increased in the treatment plots (4 and 8 Mg/ha) 1 year after application and remained elevated into year 2. Soil potassium and magnesium concentrations also increased in the treatment plots; however, changes varied in intensity depending on the element, site, and time following application. Changes in soil metal concentrations after application were restricted to the organic soil horizons increasing in the litter in year 1 followed by a decrease in year 2 that was accompanied by increases in the fibrous‐humic layer in year 2. Base cation concentrations increased significantly in sapling and mature sugar maple foliage particularly in the mature foliage in year 2. Despite changes in soil metals, changes in foliar metal concentrations were generally not significant. Foliar Diagnosis and Recommendation Integrated System indices indicated deficiencies in Ca and nitrogen (N) suggesting Ca benefits take longer to appear and that supplementing with N additions on acidic soils exhibiting foliar deficiencies might prevent further imbalances from occurring while facilitating tree recovery.

Acid rain has emerged as a significant environmental challenge, particularly in industrial regions such as Bayelsa State, Nigeria, where extensive oil exploration and gas flaring contribute to atmospheric pollution. The deposition of sulfuric and nitric acids from industrial emissions into water bodies has led to severe acidification, posing substantial risks to aquatic ecosystems. This study examines the effects of acid rain on water quality, aquatic biodiversity, and the socio-economic well-being of communities reliant on these water resources. A comprehensive research approach was employed, integrating field sampling, laboratory analysis, and socio-economic surveys. Water samples from key rivers and creeks in Bayelsa State were analyzed for pH levels, dissolved oxygen, sulfate, nitrate, and heavy metal concentrations. The findings indicate that acid rain has led to a significant drop in water pH, with values ranging from 4.2 to 5.8, far below the optimal range for aquatic life. Elevated levels of heavy metals such as aluminum, lead, and mercury were detected, further exacerbating toxicity and endangering fish populations. The study also documented biodiversity loss, particularly among sensitive fish species and plankton communities, which are vital for maintaining ecosystem balance. Additionally, socio-economic assessments revealed that declining fish stocks have severely impacted the livelihoods of local fishermen, increasing food insecurity and economic instability. Communities relying on these water bodies for drinking water and irrigation have reported rising health concerns due to heavy metal contamination. To mitigate these adverse effects, the study recommends stringent industrial regulations to curb emissions, afforestation initiatives to buffer acid deposition, and improved public awareness campaigns on environmental conservation. Strengthening environmental policies and promoting sustainable industrial practices will be crucial in safeguarding Bayelsa State’s aquatic ecosystems and ensuring long-term ecological and economic stability.

Maximising olfactory deposition of a valproic acid (VPA)-loaded nanostructured lipid carriers (NLC) formulation.

Diatom-inferred water pH variability in response to climate change and acid deposition in subtropical peatlands.

Nitrate is a key nutrient and one of the most important nitrogen sources for land plants. Besides its nutritional role, nitrate is a signal molecule that regulates plant gene expression, metabolism, physiology, growth, and development. In cotyledons and true leaves, nitrate promotes growth by inducing cell expansion. Plant cell expansion requires changes in the cell wall. However, there is scant information on the influence of nitrate on cell wall metabolism and properties during cell expansion and growth. Here, we demonstrate that nitrate availability modulates pectin metabolism, a major polysaccharide of the primary cell wall. Using colorimetric assays, immunohistochemistry, and confocal microscopy, we show that nitrate enhances methylesterified pectin during cotyledon cell expansion. This is achieved by increasing galacturonic acid (GalA) deposition as homogalacturonan (HG) and by decreasing global PME activity. We further show that this regulation is dependent on nitrate signaling pathway components, including NRT1.1 and NLP7. Pectin methylesterification state impacts the mechanical properties of the cell wall. We characterized cell wall elasticity changes during nitrate-induced expansion using atomic force microscopy (AFM) and automatic confocal microextensometry (ACME). We found that nitrate induces cell wall softening at both cellular and whole-tissue levels during this expansion process. Our results indicate pectin metabolism plays an important role in nitrate-induced cell expansion and cotyledon growth in Arabidopsis. We provide insights into the interplay between nitrate signaling, cell wall metabolism, and biomechanical properties for cell expansion. Our results contribute to our understanding of how plants sense and respond to environmental cues for growth.

Incorporating enhanced rock weathering into sustainable forest management.

Northern forests are currently taking up large quantities of carbon due to tree growth. Yet, it is not known how the stocks of soil nutrients have responded to this increase in biomass. Therefore, we analyzed thousands of forest soils in Sweden over the last four decades. We found strong increases in the concentrations and stocks of plant-available magnesium, calcium, and manganese in the organic layer of the soils. Specifically, the concentrations of plant-available magnesium, calcium, and manganese in the organic layer increased by 38%, 21%, and 100%, respectively, over the four decades. These increases were related to soil texture and the magnesium concentration of the soil parent material as well as to the dominant tree species. The increase in nutrients in the organic layer might be caused by an uplift of nutrients from the mineral subsoil to the organic layer due to plant nutrient uptake in the subsoil and litter fall and they might also be driven by decreased leaching of nutrients from the organic layer due to decreased acid deposition. Concurrently, the nitrogen content of the organic layer decreased over the four decades. In conclusion, our results show that stocks and concentrations of plant-available cations in the organic layer of Swedish forest soils increased despite increases in tree biomass and regular tree harvests. Our study indicates that there is a low risk for base cation deficiency and that nitrogen will remain the limiting nutrient for tree growth in northern forests.

Beyond rain: Fog as a dominant pathway for acid deposition in Japan's Montane Forests

A retrospective case series of 4 patients with spinal ochronosis. To evaluate the clinical, radiological, and surgical outcomes in patients with spinal ochronosis undergoing surgical intervention. Ochronosis, resulting from alkaptonuria, leads to homogentisic acid deposition in connective tissues, affecting the spine early. Due to its rarity, limited literature addresses the clinical, radiological, and surgical aspects of spinal ochronosis. We reviewed four cases of spinal ochronosis where patients underwent surgery for symptoms such as pain, paresthesia, and myelopathy. Radiological findings, intraoperative observations, and postoperative outcomes were analysed. The iOS 'Measure' app was used to quantify angles intraoperatively. Patients, aged 45-56, presented with leg pain, paresthesia, and gait disturbances. Radiographs revealed disc degeneration, spinal stenosis, and sagittal imbalance. Surgical interventions included decompression, fusion, and en bloc resection of calcified ligamentum flavum. Dural tears occurred in 2 cases but were successfully repaired. All patients experienced significant symptom relief, though residual sagittal imbalance persisted in some. Spinal ochronosis presents significant surgical challenges due to tissue fragility, adhesions. Surgical intervention can provide symptom relief, however, complete correction of deformities may not always be feasible. Further research is required to optimize treatment strategies for this rare condition.

Dietary Effects of Fish Oil Containing EPA and DHA on Performance, Fatty Acid Deposition, Plasma Oxylipins, and Cytokines in Response to LPS Challenge in Laying Hens.

Fish-assemblage and water-quality recovery with declining acidic deposition in Adirondack mountain streams, New York, USA

Abstract Disclosure: J. Salinas: None. J.S. Burgos: None. J.R. Camano: None. A.P. Sinha-Hikim: None. T.C. Friedman: None. K.M. Hasan: None. Metabolic dysfunction-associated steatotic liver disease (MASLD) is highly prevalent in the U.S. population, affecting approximately 30-35% of individuals. It is considered a critical risk factor for type 2 diabetes (T2D), cardiovascular diseases (CVD), and hepatic cancer. However, no effective therapeutics are currently available to cure this chronic metabolic condition, making it imperative to understand its molecular mechanisms. CARF (CDKN2AIP) is a novel multifunctional gene that has been shown to regulate cellular fate in response to various stresses, including DNA damage, oxidative stress, and replication stress. Until recently, its response to metabolic or over-nutrition stress was unknown. Our recent study demonstrated that CARF expression is dramatically reduced in response to free fatty acid (FFA) deposition in the liver, suggesting that CARF may play a protective role against MASLD. Supporting this hypothesis, overexpression of CARF was found to suppress MASLD in a high-fat diet (HFD)-induced mouse model of the disease. However, the underlying mechanisms by which CARF suppresses MASLD remain largely unknown. To address this, transcriptome analysis by RNA sequencing upon silencing of CARF revealed that the PPARα signaling pathway, which regulates cellular fatty acid oxidation (FAO), was altered in hepatocytes. We hypothesize that silencing CARF attenuates hepatic FAO, leading to fat deposition in hepatocytes. Using RT-PCR and western blotting, we confirmed that the expression of multiple PPARα signaling pathway genes, including CPT2, MCAD, and ACAD9, was reduced in CARF-depleted HepG2 cells. Furthermore, using palmitate as a substrate in Seahorse metabolic analysis, we demonstrated that CARF overexpression enhances the oxygen consumption rate (OCR) in HepG2 cells, suggesting that CARF regulates mitochondrial β-oxidation. Consistent with this, CPT2 expression, along with CARF, was significantly reduced in HFD-fed livers, indicating that the CARF-CPT2 axis could play a vital role in hepatic FAO. Intriguingly, hepatic overexpression of CARF restored CPT2 expression in HFD-fed livers, which could be accounted for CARF's protective role against MASLD in mice. In conclusion, these results establish CARF as a novel regulator of cellular fatty acid metabolism. Its dysregulation could contribute to the development of MASLD, warranting further research to evaluate its clinical significance. Presentation: Saturday, July 12, 2025

The pace and trajectory of ecosystem development are governed by the availability and cycling of limiting nutrients, and anthropogenic disturbances such as acid rain and deforestation alter these trajectories by removing substantial quantities of nutrients via titration or harvest. Here, we use six decades of continuous chemical and hydrologic data from three adjacent headwater catchments in the Hubbard Brook Experimental Forest, New Hampshire-one deforested (W5), one CaSiO3-enriched (W1), and one reference (W6)-to quantify long-term nutrient and mineral fluxes. Acid deposition since 1900 drove pronounced depletion and export of base cations, particularly calcium, across all watersheds. Experimental deforestation of W5 intensified loss of biomass and nutrient cations and triggered sustained increases in streamwater pH, Ca2+, and SiO2 exports over nearly four decades, greatly exceeding the effects of direct CaSiO3 enrichment in both duration and magnitude. We detect no long-term changes in water yield or water flow paths in the experimental watersheds, and we attribute this multidecadal increase in weathering rates following deforestation to biological responses to severe nutrient limitation. Our evidence suggests that in the regrowing forest, plants are investing photosynthate into belowground processes that amplify mineral weathering to access phosphorus and micronutrients, consequently elevating the export of less limiting elements present in silicate parent material. Throughout decades of forest regrowth, enhanced biotic weathering has continued to deplete the acid buffering capacity of the terrestrial ecosystem while the export of weathering products has elevated the pH of the receiving stream.