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Cold-season emissions substantially contribute to the annual methane budget of northern wetlands, yet they remain underestimated by process-based models. Models show significant uncertainty in their parameterization of processes, particularly during the transitional phases of freezing and thawing temperatures in the shoulder seasons. Our aim was to identify the environmental controls on the components of the methane fluxes – methane production, oxidation, and transport – from a boreal peatland during the shoulder seasons. We partitioned net methane emissions into their components by combining manual chamber flux measurements on vegetation removal treatments with pore water sampling for concentrations and stable carbon isotope ratios of dissolved methane in the wet hollows of Siikaneva bog in southern Finland during seasonal field campaigns in 2021 and 2022. The results suggest that the decrease in methane emissions due to decreasing production rates with decreasing peat temperatures in the shoulder seasons was dampened by several processes. Firstly, highly efficient transport of methane through the aerenchyma of peatland sedges continued outside of the growing season after plant senescence. Secondly, decaying vascular plants provided additional substrate for methane production at the end of the growing season. Thirdly, accumulation of methane in the pore water partly delayed the emission of methane produced in summer and winter compared to the shoulder seasons. Substrate-limited oxidation rates, however, largely compensated for the higher diffusion rates related to high pore water concentrations in fall. Accounting for these processes specific to the shoulder seasons by separately modeling the components of methane fluxes will likely work against the underestimation of cold-season methane emissions from northern peatlands.

During permafrost thaw, nitrogen can be released as the greenhouse gas nitrous oxide, but the magnitude of this flux is unknown. Nitrous oxide emissions from ice-rich permafrost deposits are reported here, showing that emissions increase after thawing and stabilization and could represent an unappreciated positive climate feedback in the Arctic.

Urbanisation is becoming increasingly important in terms of climate change and ecosystem functionality worldwide. We are only beginning to understand how the processes of urbanisation influence ecosystem dynamics, making peri-urban environments more vulnerable to nutrient losses. Brisbane in South East Queensland has the most extensive urban sprawl of all Australian cities. This research estimated the environmental impact of land use change associated with urbanisation by examining soil nitrogen (N) turnover and subsequent nitrous oxide (N2O) emissions using a fully automated system that measured emissions on a sub-daily basis. There was no significant difference in soil N2O emissions between the native dry sclerophyll eucalypt forest and an extensively grazed pasture, wherefrom only low annual emissions were observed amounting to 0.1 and 0.2 kg N2O ha−1 yr−1, respectively. The establishment of a fertilised turf grass lawn increased soil N2O emissions 18-fold (1.8 kg N2O ha−1 yr−1), with highest emissions occurring in the first 2 months after establishment. Once established, the turf grass lawn presented relatively low N2O emissions for the rest of the year, even after fertilisation and rain events. Soil moisture was significantly higher, and mineralised N accumulated in the fallow plots, resulting in the highest N2O emissions (2.8 kg N2O ha−1 yr−1) and significant nitrate (NO3−) losses, with up to 63 kg N ha−1 lost from a single rain event due to reduced plant cover removal. The study concludes that urbanisation processes creating peri-urban ecosystems can greatly modify N cycling and increase the potential for losses in the form of N2O and NO3−.

Global atmospheric concentrations of nitrous oxide have been increasing over previous decades with emerging research suggesting the Arctic as a notable contributor. Thermokarst processes, increasing temperature, and changes in drainage can cause degradation of polygonal tundra landscape features resulting in elevated, well-drained, unvegetated soil surfaces that exhibit large nitrous oxide emissions. Here, we outline the magnitude and some of the dominant factors controlling variability in emissions for these thermokarst landscape features in the North Slope of Alaska. We measured strong nitrous oxide emissions during the growing season from unvegetated high centered polygons (median (mean) = 104.7 (187.7) µg N 2 O-N m -2  h -1 ), substantially higher than mean rates associated with Arctic tundra wetlands and of similar magnitude to unvegetated hotspots in peat plateaus and palsa mires. In the absence of vegetation, isotopic enrichment of 15 N in these thermokarst features indicates a greater influence of microbial processes, (denitrification and nitrification) from barren soil. Findings reveal that the thermokarst features discussed here (~1.5% of the study area) are likely a notable source of nitrous oxide emissions, as inferred from chamber-based estimates. Growing season emissions, estimated at 16 (28) mg N 2 O-N ha -1  h -1 , may be large enough to affect landscape-level greenhouse gas budgets., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s) 2024.)

Mountain birch forests (Betula pubescens Ehrh. ssp. czerepanovii) at the subarctic treeline not only benefit from global warming, but are also increasingly affected by caterpillar outbreaks from foliage-feeding geometrid moths. Both of these factors have unknown consequences on soil organic carbon (SOC) stocks and biogeochemical cycles. We measured SOC stocks down to the bedrock under living trees and under two stages of dead trees (12 and 55 years since moth outbreak) and treeless tundra in northern Finland. We also measured in-situ soil respiration, potential SOC decomposability, biological (enzyme activities and microbial biomass), and chemical (N, mineral N, and pH) soil properties. SOC stocks were significantly higher under living trees (4.1 ± 2.1 kg m²) than in the treeless tundra (2.4 ± 0.6 kg m²), and remained at an elevated level even 12 (3.7 ± 1.7 kg m²) and 55 years (4.9 ± 3.0 kg m²) after tree death. Effects of tree status on SOC stocks decreased with increasing distance from the tree and with increasing depth, that is, a significant effect of tree status was found in the organic layer, but not in mineral soil. Soil under living trees was characterized by higher mineral N contents, microbial biomass, microbial activity, and soil respiration compared with the treeless tundra; soils under dead trees were intermediate between these two. The results suggest accelerated organic matter turnover under living trees but a positive net effect on SOC stocks. Slowed organic matter turnover and continuous supply of deadwood may explain why SOC stocks remained elevated under dead trees, despite the heavy decrease in aboveground C stocks. We conclude that the increased occurrence of moth damage with climate change would have minor effects on SOC stocks, but ultimately decrease ecosystem C stocks (49% within 55 years in this area), if the mountain birch forests will not be able to recover from the outbreaks., (© 2021 The Authors. Global Change Biology published by John Wiley & Sons Ltd.)

In contrast to the well-recognized permafrost carbon (C) feedback to climate change, the fate of permafrost nitrogen (N) after thaw is poorly understood. According to mounting evidence, part of the N liberated from permafrost may be released to the atmosphere as the strong greenhouse gas (GHG) nitrous oxide (N 2 O). Here, we report post-thaw N 2 O release from late Pleistocene permafrost deposits called Yedoma, which store a substantial part of permafrost C and N and are highly vulnerable to thaw. While freshly thawed, unvegetated Yedoma in disturbed areas emit little N 2 O, emissions increase within few years after stabilization, drying and revegetation with grasses to high rates (548 (133-6286) μg N m -2 day -1 ; median with (range)), exceeding by 1-2 orders of magnitude the typical rates from permafrost-affected soils. Using targeted metagenomics of key N cycling genes, we link the increase in in situ N 2 O emissions with structural changes of the microbial community responsible for N cycling. Our results highlight the importance of extra N availability from thawing Yedoma permafrost, causing a positive climate feedback from the Arctic in the form of N 2 O emissions., (© 2021. The Author(s).)

We investigated longitudinal associations of moderate-to-vigorous physical activity (MVPA) and light-intensity physical activity (LPA) with plasma concentrations of 138 metabolites after colorectal cancer (CRC) treatment. Self-reported physical activity data and blood samples were obtained at 6 weeks, and 6, 12 and 24 months post-treatment in stage I-III CRC survivors (n = 252). Metabolite concentrations were measured by tandem mass spectrometry (BIOCRATES AbsoluteIDQp180 kit). Linear mixed models were used to evaluate confounder-adjusted longitudinal associations. Inter-individual (between-participant differences) and intra-individual associations (within-participant changes over time) were assessed as percentage difference in metabolite concentration per 5 h/week of MVPA or LPA. At 6 weeks post-treatment, participants reported a median of 6.5 h/week of MVPA (interquartile range:2.3,13.5) and 7.5 h/week of LPA (2.0,15.8). Inter-individual associations were observed with more MVPA being related (FDR-adjusted q-value < 0.05) to higher concentrations of arginine, citrulline and histidine, eight lysophosphatidylcholines, nine diacylphosphatidylcholines, 13 acyl-alkylphosphatidylcholines, two sphingomyelins, and acylcarnitine C10:1. No intra-individual associations were found. LPA was not associated with any metabolite. More MVPA was associated with higher concentrations of several lipids and three amino acids, which have been linked to anti-inflammatory processes and improved metabolic health. Mechanistic studies are needed to investigate whether these metabolites may affect prognosis.

Purpose: Evidence from cross-sectional studies suggests that higher levels of light-intensity physical activity (LPA) are associated with better health-related quality of life (HRQoL) in colorectal cancer (CRC) survivors. However, these associations have not been investigated in longitudinal studies that provide the opportunity to analyse how within-individual changes in LPA affect HRQoL. We investigated longitudinal associations of LPA with HRQoL outcomes in CRC survivors, from 6 weeks to 2 years post-treatment., Methods: Data were used of a prospective cohort study among 325 stage I-III CRC survivors (67% men, mean age: 67 years), recruited between 2012 and 2016. Validated questionnaires were used to assess hours/week of LPA (SQUASH) and HRQoL outcomes (EORTC QLQ-C30, Checklist Individual Strength) at 6 weeks, and 6, 12 and 24 months post-treatment. We applied linear mixed regression to analyse longitudinal confounder-adjusted associations of LPA with HRQoL., Results: We observed statistically significant longitudinal associations between more LPA and better global quality of life and physical, role and social functioning, and less fatigue over time. Intra-individual analysis showed that within-person increases in LPA (per 8 h/week) were related to improved HRQoL, including better global quality of life (β = 1.67, 95% CI 0.71; 2.63; total range scale: 0-100) and less fatigue (β = - 1.22, 95% CI - 2.37; - 0.07; scale: 20-140). Stratified analyses indicated stronger associations among participants below the median of moderate-to-vigorous physical activity (MVPA) at diagnosis., Conclusion: Higher levels of LPA were longitudinally associated with better HRQoL and less fatigue in CRC survivors up to two years post-treatment. Further prospective studies using accelerometer data are necessary to inform development of interventions targeting LPA.

Increasing population densities and urban sprawl are causing rapid land use change from natural and agricultural ecosystems into smaller, urban residential properties. However, there is still great uncertainty about the effect that urbanization will have on biogeochemical C and N cycles and associated greenhouse gas (GHG) budgets. We aimed to evaluate how typical urbanization related land use change in subtropical Australia affects soil GHG exchange (N 2 O and CH 4 ) and the associated global warming potential (GWP). Fluxes were measured from three land uses: native forest, a long-term pasture, and a turf grass lawn continuously over two years using a high-resolution automated chamber system. The fertilized turf grass had the highest N 2 O emissions, dominated by high fluxes >100 g N 2 O-N day -1 immediately following establishment though decreased to just 0.6 kg N 2 O-N ha -1 in the second year. Only minor fluxes occurred in the forest and pasture, with the high aeration of the sandy topsoil limiting N 2 O emissions while promoting substantial CH 4 uptake. Native forest was consistently the strongest CH 4 sink (-2.9 kg CH 4 -C ha -1  year -1 ), while the pasture became a short-term CH 4 source after heavy rainfall when the soil reached saturation. On a two-year average, land use change from native forest to turf grass increased the non-CO 2 GWP from a net annual GHG sink of -83 CO 2 -e ha -1  year -1 to a source of 245 kg CO 2 -e ha -1  year -1 . This study highlights that urbanization can substantially alter soil GHG exchange by altering plant soil water use and by increasing bulk density and inorganic N availability. However, on well-drained subtropical soils, the impact of urbanization on inter-annual non-CO 2 GWP of turf grass was low compared to urbanized ecosystems in temperate climates., (© 2018 John Wiley & Sons Ltd.)

A typical fibroxanthoma is a solitary tumour of the skin, which occurs mostly on sun-exposed areas in elderly people. The diagnosis can only be made with certainty on the typical histological findings, which suggest a bizarre malignant tumour. Although metastasizing tumours are reported in the literature, the authors believe that the true atypical fibroxanthoma is benign. Correct diagnosis obviates the need for unnecessary radical surgery. The possibility of atypical fibroxanthoma should always be considered when a histologically bizarre tumour is found on sun-damaged or irradiation-damaged skin in elderly patients or on previously traumatized sites. In this paper five cases are added to the 346 cases culled from the literature. Electron microscopic investigations in one case demonstrated cells with delicate cytoplasmic fibrils in small bundles. This does not necessarily suggest filaments of myofibroblasts, as has been previously reported.

Complete resolution of glomerular changes in toxemia of pregnancy has been reported to occur as early as 4 weeks postpartum, whereas their persistence for as long as 2 years in some instances has been noted. However, the mechanism of resolution remains obscure. Percutaneous renal biopsy was performed in 22 patients between 10 and 14 days after delivery. These women fulfilled the criteria for toxemia of pregnancy (edema-proteinuria-hypertension gestosis). Biopsy specimens were examined, using light, immunofluorescence and electron microscopy. Semithin sections were studied in view of greater reliability and better relation with further electron microscopic studies. A diffuse increase in mesangial cellularity and matrix was seen in all glomeruli with varying intensity, compatible with mesangium activity, more than endothelial proliferation. So-called capillary occlusions by endothelial swelling were not observed in the biopsies taken 10 days after delivery, but expulsed mesangial cytoplasm could be observed incidentally in the capillary lumen. This phenomenon may explain the wrong interpretation of paraffin sections studied by light microscopy. The presence of immunoglobulins in the glomeruli, seen by immunofluorescence, seems to be nonspecific trapping. In view of experimental studies of mesangium function in macromolecular uptake and processing, it is possible that resolution of the characteristic renal lesions in toxemia is promoted by mesangium activity.

In the immotile cilia syndrome, transmission electron microscopy of the cilia shows abnormalities in the arrangement of the central pairs of tubules and in the dynein arms of the peripheral tubules, or in the radial spokes, We studied four nonrelated children, 9/12, 5, 6, and 6 years old, with situs inversus and a history of chronic sinusitis and bronchitis (Kartagener's syndrome) and four children in the same age group and with the same history, but without situs inversus. Under the phase contrast microscope no motile cilia were seen in the four patients with Kartagener's syndrome and in two of the four other children. Transmission electron microscopy showed aberrations in the cilia (absence of dyneim arms, random orientation of central tubules) in the patients with Kartagener's syndrome. Scanning electron microscopy revealed differences in morphology and arrangement of cilia between patients and controls. In the patients much more mucus was present on the mucosal surface. Furthermore, the cilia were in a state of disorder, with a multidirectional orientation instead of the parallel orientation seen in controls.

A patient with congenital ichthyosis and progressive neurologic anomalies showed disturbances in the specific humoral and cellular defense as well as the presence of atypical lymphoid cells in skin and lymph node. The latter resembled the atypical T cells found in mycosis fungoides and Sézary syndrome. The possibility of the presence of either a cutaneous T cell lymphoma or unregulated T cell stimulation leading to concurrent immunodeficiency in this patient is discussed.

In the past decades many changes have taken place in the classification of lymphoreticular malignancies. At present two main groups are recognized--Hodgkin's lymphomas and non-Hodgkin's lymphomas. Hodgkin's lymphomas rarely affect the oral cavity. The mouth, especially the soft tissues, is somewhat more frequently involved in cases of non-Hodgkin's lymphoma. There seems to be some predilection for the mucosa of the palate. The present report describes eight patients in whom a swelling of the palatal mucosa led to the diagnosis of non-Hodgkin's lymphoma. The emphasis is on the clinical and microscopic aspects. The present most accepted histologic classifications have been applied and are briefly discussed.