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Abstract Background Osteoarthritis in the thumb base (trapeziometacarpal joint, CMC-1 joint) is prevalent, particularly among middle-aged and elderly women, causing significant disability. Conservative treatments, including steroid injections, have been questioned for their efficacy, prompting exploration into alternative therapies such as platelet-rich plasma (PRP) injections. This randomized, double-blinded, controlled trial aims to evaluate the effectiveness of high-concentration PRP (platelet-rich plasma) injection compared to saline (placebo) in reducing pain and disability in patients with thumb base osteoarthritis. Methods Patients meeting inclusion criteria will be randomized and blinded, with injections administered under sterile conditions and radiological guidance. With a planned sample size of 90 patients recruited from the Department of Hand Surgery at Södersjukhuset, Stockholm, the study will assess pain relief and functional improvement at 3, 6, and 12 months post-injection. The primary outcome measure is pain on load (numerical rating scale) at 6 months, with secondary outcomes including patient-reported outcomes, key pinch, grip strength, abduction of the thumb, and time to intervention within 1 year. Statistical analyses will employ non-parametric tests, chi-square tests, and generalized estimating equations to compare outcomes between the PRP and placebo groups. Discussion The study aims to provide evidence regarding the efficacy of high-concentration PRP injections for thumb base osteoarthritis. If PRP proves superior to saline in reducing pain and improving function, it could offer a promising alternative treatment. Conversely, if PRP does not demonstrate significant benefits over placebo, its use for this condition is not justified. This study seeks to address the current gap in evidence regarding the efficacy of PRP injections for thumb base osteoarthritis. Trial registration The study has been approved by the Swedish Ethical Review Authority (2023–06860-01 and 2024–01238-02) and is registered on ClinicalTrials.gov (NCT06193499) 2024–01-04.

From the beginning of building techniques creating pre-stressed and accordingly post-tensioned concrete structures until the late 1980ies manufacturers and construction companies dealt with pre-stressing steel material vulnerable to stress corrosion cracking. Almost every load-bearing structure requires regular inspection on a mandatory basis. Due to knowledge of pre-stressed structural reinforcement susceptible to stress corrosion cracking being used during construction or visible damage alongside the tendon area arises the demand for detailed investigation of cracks within the post-tensioned steel elements. Even though the pre-stressed steel elements of a structure are not especially at risk for stress corrosion cracking by its manufacturing process, the natural deterioration of the building fabric and manifold eventual defects and failure during structure erection encourage the requirement for an inspection of their structural integrity at least within the most important load-bearing areas. Therefore needed investigations can be carried out by application of the non-destructive magnetic flux leakage measurement technique for single bar elements and stranded wire tendons even inside cladding tubes. This testing method is subject to successful research work for more than 30 years now and has proven its validated functionality with impressive results on a big number of investigated structures including bridge elements, truss beams and container components.Starting with the basic physical measurement principle of magnetic flux leakage for dipole-formation in the area of fractures of the magnetized pre-stressed steel elements this document presents the practical application possibilities and development history of the testing method.With the consecutively presented further development of the BetoFlux-System we can provide a piece of testing equipment which combines the advantages of a pure physical measurement principle with the economical requirements for an on-site-application to investigate pre-stressed reinforcing steel elements at an early stage prior to structural collapse hazards.

Comparison is an everyday process of thinking, which is also frequently used in geography lessons. However, in geography pedagogy, the term 'comparison' remains vague and insufficiently defined. In this paper, we will propose a clear definition of what comparison is and introduce it as a systematic method for secondary school geography education. This definition and method is the result of our theoretical-conceptual approach, according to which we have analyzed the current academic discussion about scientific comparison and converted it into a method for teaching. We argue that applying comparison as a pedagogical tool may improve students' skills to argue, reflect, solve problems, and promote good judgement.

Five nearly identical fragments of specialized bone tools, interpreted as lissoirs (French for "smoothers"), have been found at two Middle Paleolithic sites in southwest France. The finds span three separate archaeological deposits, suggesting continuity in the behavior of late Neandertals. Using standard morphological assessments, we determined that the lissoirs were produced on ribs of medium-sized ungulates. However, since these bones are highly fragmented and anthropogenically modified, species determinations were challenging. Also, conservative curation policy recommends minimizing destructive sampling of rare, fragile, or small artifacts for molecular identification methods. To better understand raw material selection for these five lissoirs, we reassess their taxonomy using a non-destructive ZooMS methodology based on triboelectric capture of collagen. We sampled four storage containers and obtained identifiable MALDI-TOF MS collagen fingerprints, all indicative of the same taxonomic clade, which includes aurochs and bison (Bos sp. and Bison sp.). The fifth specimen, which was stored in a plastic bag, provided no useful MALDI-TOF MS spectra. We show that the choice of large bovid ribs in an archaeological layer dominated by reindeer (Rangifer tarandus) demonstrates strategic selection by these Neandertals. Furthermore, our results highlight the value of a promising technique for the non-destructive analysis of bone artifacts.

Quantile mapping is a method often used for the bias adjustment of climate model data toward a reference, i.e. to construct a transformation of the model's distribution to that of the reference. The main moments of the distributions are typically well transformed by quantile mapping, but statistical uncertainty increases towards the extreme tails, making robust transformations challenging. Because of the limited data at the extreme tails, an empirical quantile mapping also needs to make some estimation or fit a parameterised function for data beyond the calibration data range. Here, the MIdAS bias adjustment platform is employed to explore different methods for handling the extreme tail; these approaches are evaluated using an indicator of extreme precipitation – the maximum daily precipitation amount per year. Different methodologies are evaluated for a large ensemble of regional climate model projections over Scandinavia. The sensitivity of the empirical quantile mapping to the tails of the distribution is demonstrated, and it is found that the behaviour is significantly different within and outside of the calibration period, causing severe issues with the temporal consistency of the time series. The sensitivity is identified to be due to differences in the activated features of the bias adjustment within the calibration period (where the empirical transfer function is applied) and outside of that period (where the extrapolation method is likely applied). This means that the bias adjustment method is, in a sense, different between different time periods. Furthermore, finding a robust parameterisation for the tail is not straightforward. We identify a two-step solution that works well for this problem: We refer to the first step as "Murder your darlings". By excluding data from the tail data in the calibration period, the extrapolation feature is activated for all time periods, even the calibration period. In the second step, applying an outlier-insensitive method for linear regression works well for finding an extrapolation parameterisation for the tail. [ABSTRACT FROM AUTHOR]

The composition of plant functional traits varies in response to environmental conditions due to processes of community assembly and species sorting. However, there is a lack of understanding of how plant trait composition responds to environmental conditions at different spatial scales and across the plant life cycle. We investigated the trait composition of leaves (specific leaf area), seeds (seed mass) and seedlings (initial seedling height) across elevations and within elevations in relation to soil and light conditions in a tropical montane forest in southern Ecuador. We surveyed traits and communities of adult trees, seeds and seedlings on nine plots at three elevations (1000–3000 m a.s.l.) and calculated community‐weighted mean trait values to analyse trait variation across and within elevations. In addition, we measured two environmental factors (soil C/N ratio and canopy openness) to quantify local‐scale variation in environmental conditions within elevations. We found that community‐weighted means of specific leaf area, seed mass and initial seedling height decreased consistently with increasing elevation. Within elevations, mean trait values of trees, seeds and seedlings responded differently to local‐scale environmental conditions. Specific leaf area decreased with increasing soil C/N ratio, and initial seedling height decreased with increasing canopy openness. Seed mass was associated neither with soil nor with light conditions. Our findings show that broad‐scale and local‐scale processes differently shape the composition of leaf, seed and seedling traits in tropical forests, indicating a scale‐dependence in trait–environment associations. Furthermore, plant traits corresponding to different life stages were related differently to environmental conditions within elevations. Community assembly processes may therefore lead to differences in species sorting at early and late plant life stages. [ABSTRACT FROM AUTHOR]

The globally increasing reactive N richness affects even remote ecosystems such as the tropical montane forests in Ecuador. We tested whether the δ15N values of total dissolved N (TDN), measured directly in solution with a TOC‐IRMS, can be used to help elucidate N sources and sinks along the water path and thus might be suitable for ecosystem monitoring. From 2013 to 2016, the δ15N values of TDN in bulk deposition showed the most pronounced temporal variation of all ecosystem solutions (δ15N values: 1.9–5.9‰). In throughfall (TF), TDN was on average 15N‐depleted (−1.8 ± s.d. 0.4‰) relative to rainfall (3.4 ± 0.9‰), resulting from net retention of isotopically heavy N, mainly as NH4+. Simultaneously, N‐isotopically light NO3−‐N and dissolved organic nitrogen (DON) with a δ15N value between NO3−‐N and NH4+‐N were leached from the canopy (leaves: −3.5 ± 0.5‰). The increasing δ15N values in the order, TF < stemflow (SF, 0.1 ± 0.6‰)< litter leachate (LL, 1.3 ± 0.7‰) concurred with an increasing DON contribution to TDN reflecting the δ15N value of the organic layer (1.9 ± 0.9‰). The lower δ15N value of the mineral soil solution at the 0.15 m soil depth (SS15, −1.5 ± 0.3‰) than in LL can be explained by the retention of DON and NH4+ and the addition of NO3− from mineralization and nitrification. The increasing δ15N values in the order, SS15 < SS30 (−0.6 ± 0.2‰) < streamflow (ST, 0.5 ± 0.6‰) suggested gaseous N losses because of increasing denitrification. There was no seasonality of the δ15N values. Our results demonstrate that the δ15N values of TDN in ecosystem solutions help identify N sources and sinks in forest ecosystems. Plain Language Summary: Many ecosystems experience increasing nitrogen availability because of nitrogen deposition from the atmosphere caused by human activities. The deposited nitrogen can produce a growth boost or be leached into groundwater and surface water. The stable isotope ratios of nitrogen (δ15N values) provide a tool to investigate into the consequences of increasing nitrogen availability. Here, we applied a new direct measurement method of δ15N values in total dissolved nitrogen of ecosystem solutions to follow sources and sinks of nitrogen in a tropical montane rain forest in Ecuador. We found that the isotopically heavy nitrogen input via rainfall is enriched by isotopically lighter nitrogen from plants and nitrogen turnover during the water passage through the canopy. Once, the solutions reach the mineral soil, dissolved organic nitrogen, which is comparatively rich in the heavy nitrogen isotope, is retained rendering the remaining nitrogen isotopically lighter. This process is reversed deeper in the soil by conversion of the nitrate to nitrogen gasses, which are depleted in the heavy nitrogen isotope and leave the ecosystem to the atmosphere. The direct measurement of δ15N values provides a tool to monitor the changing nitrogen cycle in ecosystems. Key Points: Increasing δ15N values in total dissolved nitrogen from throughfall to litter leachate correlated with an increasing organic contributionThe retention of N‐isotopically heavy dissolved organic nitrogen in the mineral topsoil decreased the δ15N values in mineral soil solutionsIncreasing δ15N values from the topsoil solution via the subsoil to the streamflow suggested gaseous N losses because of denitrification [ABSTRACT FROM AUTHOR]

The geochemical composition of sediment cores can serve as a proxy for reconstructing past human and nature-driven environmental and climatic changes. We investigated the temporal variation in the concentrations and fluxes of polycyclic aromatic compounds (PACs) which include polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs, and azaarenes in the Sihailongwan Maar Lake and found that they remained low before 1950. The PAC concentrations and fluxes increased substantially since 1950, which was in good agreement with the fast socio-economic development, industrialization, and associated growth in fossil fuel consumption in China, particularly since the 1980s. After 2010, the PAC fluxes decreased, which was consistent with the implementation of air pollution control policies in China at that time. The concentration ratios of the sums of low to high molecular weight PAHs (LMW-PAHs/HMW-PAHs), benzo[e]pyrene/benzo[a]pyrene, and benzo[a]anthracene-7,12-dione/benzo[a]anthracene all decreased from bottom to top of the sediment core, reflecting the rapidly increasing contribution of emissions derived from high-temperature fossil fuel combustion (energy, transport and industry) to the PAC emissions in recent times at the expense of biomass burning. In addition, these data reflect the increasing local sources of PACs in more recent times because of the enhanced human activities in the area surrounding the Maar lake. Our results demonstrate that PAC fluxes and concentrations in sediment cores reflect the regional and national economic development and the efficiency of pollution control measures. [ABSTRACT FROM AUTHOR]