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The temporal dynamics of 33 major, trace, and rare earth elements (REEs) were studied in the litter samples containing Swedish Norway spruce (Picea abies) (NSL) and Scots pine (Pinus sylvestris) (SPL), with the aim to assess their release and accumulation dynamics. Litter bags (8 × 8 cm) were incubated in paired monoculture stands with both the species for up to 5 years from 1979 to 1984 according to a randomized block design comprising 25 blocks (1 × 1 m) within an area of 625 m2. The decomposition rate was slightly higher for Scots pine litter (k = 0.315) than for Norway spruce litter (k = 0.217). During litter decomposition, at ∼70% accumulated mass loss (AML), the concentration of trace elements increased by >50% in both litter types compared to initial concentrations. The concentration change took place in a non-linear pattern, and polynomial quadratic regression between concentration change and accumulated mass loss resulted in significant relationships (adj R2 = 0.20–0.97; p = 0.15–0.95). A general upward convexity in the dynamics suggests that if further incubated in the field, decomposing litter could have accumulated more REEs in the organic matter. The results of this study can be useful for future studies in other ecosystems including metal-contaminated sites or element-depleted sites. Plant litter accumulation, its decomposition, and build-up of humic substances in the decomposing organic matter can act as a sink for elements and can be used as a management tool for ecological amelioration of metal-contaminated sites as well as natural systems that are impoverished, especially recuperating sites. The study’s findings have implications beyond such sites and can be useful in any research that seeks to understand the patterns of accumulation and release related to decomposition in different ecosystems.

Abstract Background Nitrogen (N) deposition alters litter decomposition and soil carbon (C) sequestration by influencing the microbial community and its enzyme activity. Natural atmospheric N deposition comprises of inorganic N (IN) and organic N (ON) compounds. However, most studies have focused on IN and its effect on soil C cycling, whereas the effect of ON on microbial enzyme activity is poorly understood. Here we studied the effects of different forms of externally supplied N on soil enzyme activities related to decomposition in a temperate steppe. Ammonium nitrate was chosen as IN source, whereas urea and glycine were chosen as ON sources. Different ratios of IN to ON (Control, 10:0, 7:3, 5:5, 3:7, and 0:10) were mixed with equal total amounts of N and then used to fertilize the grassland soils for 6 years. Results Our results show that IN deposition inhibited lignin-degrading enzyme activity, such as phenol oxidase (POX) and peroxidase (PER), which may restrain decomposition and thus induce accumulation of recalcitrant organic C in grassland soils. By contrast, deposition of ON and mixed ON and IN enhanced most of the C-degrading enzyme activities, which may promote the organic matter decomposition in grassland soils. In addition, the β-N-acetyl-glucosaminidase (NAG) activity was remarkably stimulated by fertilization with both IN and ON, maybe because of the elevated N availability and the lack of N limitation after long-term N fertilization at the grassland site. Meanwhile, differences in soil pH, soil dissolved organic carbon (DOC), and microbial biomass partially explained the differential effects on soil enzyme activity under different forms of N treatments. Conclusions Our results emphasize the importance of organic N deposition in controlling soil processes, which are regulated by microbial enzyme activities, and may consequently change the ecological effect of N deposition. Thus, more ON deposition may promote the decomposition of soil organic matter thus converting C sequestration in grassland soils into a C source.

Litter decomposition is a key process for carbon and nutrient cycling in terrestrial ecosystems and is mainly controlled by environmental conditions, substrate quantity and quality as well as microbial community abundance and composition. In particular, the effects of climate and atmospheric nitrogen (N) deposition on litter decomposition and its temporal dynamics are of significant importance, since their effects might change over the course of the decomposition process. Within the TeaComposition initiative, we incubated Green and Rooibos teas at 524 sites across nine biomes. We assessed how macroclimate and atmospheric inorganic N deposition under current and predicted scenarios (RCP 2.6, RCP 8.5) might affect litter mass loss measured after 3 and 12 months. Our study shows that the early to mid-term mass loss at the global scale was affected predominantly by litter quality (explaining 73% and 62% of the total variance after 3 and 12 months, respectively) followed by climate and N deposition. The effects of climate were not litter-specific and became increasingly significant as decomposition progressed, with MAP explaining 2% and MAT 4% of the variation after 12 months of incubation. The effect of N deposition was litter-specific, and significant only for 12-month decomposition of Rooibos tea at the global scale. However, in the temperate biome where atmospheric N deposition rates are relatively high, the 12-month mass loss of Green and Rooibos teas decreased significantly with increasing N deposition, explaining 9.5% and 1.1% of the variance, respectively. The expected changes in macroclimate and N deposition at the global scale by the end of this century are estimated to increase the 12-month mass loss of easily decomposable litter by 1.1–3.5% and of the more stable substrates by 3.8–10.6%, relative to current mass loss. In contrast, expected changes in atmospheric N deposition will decrease the mid-term mass loss of high-quality litter by 1.4–2.2% and that of low-quality litter by 0.9–1.5% in the temperate biome. Our results suggest that projected increases in N deposition may have the capacity to dampen the climate-driven increases in litter decomposition depending on the biome and decomposition stage of substrate.

Collected harmonized data on global litter decomposition are of great relevance for scientists, policymakers, and for education of the next generation of researchers and environmental managers. Here we describe the TeaComposition initiative, a global and open research collaborative network to study organic matter decomposition in a standardized way allowing comparison of decomposition rate and carbon turnover across global and regional gradients of ecosystems, climate, soils etc. The TeaComposition initiative today involves 570 terrestrial and 300 aquatic ecosystems from nine biomes worldwide. Further, we describe how to get involved in the TeaComposition initiative by (a) implementing the standard protocol within your study site, (b) joining task forces in data analyses, syntheses and modelling efforts, (c) using collected data and samples for further analyses through joint projects, (d) using collected data for graduate seminars, and (e) strengthening synergies between biogeochemical research and a wide range of stakeholders. These collaborative efforts within/emerging from the TeaComposition initiative, thereby, will leverage our understanding on litter decomposition at the global scale and strengthen global collaborations essential for addressing grand scientific challenges in a rapidly changing world.

Abstract Evergreen and deciduous broad‐leaved tree species can coexist across the globe and constitute different broad‐leaved forests along large‐scale geographical and climatic gradients. A better understanding of climatic influence on the distribution of mixed evergreen and deciduous broad‐leaved forest is of fundamental importance when assessing this mixed forest's resilience and predicting potential dynamics of broad‐leaved forests under future climate change. Here, we quantified the horizontal distribution of this mixed forest in mountains in relation to climate seasonality by compiling vegetation information from the earlier records and our own field sampling on major subtropical mountains of China. We found that the probability of occurrence of this forest in subtropical mountains was positively associated with the latitude but not the longitude. The occurrence probability of this forest was observed at high‐temperature but not precipitation seasonality mountains. Temperature seasonality was five times more important than precipitation seasonality in explaining the total variation of occurrence of this mixed forest. For its distribution, our results shed light on that temperature seasonality was generally a more powerful predictor than precipitation seasonality for montane mixed forest distribution. Collectively, this study clearly underscores the important role of temperature seasonality, a previously not quantified climatic variable, in the occurrence of this mixed forest along geographical gradients and hence yields useful insight into our understanding of climate–vegetation relationships and climate change vulnerability assessment in a changing climate.

This paper studies whether a board game can effectively raise awareness of cultural differences and their impacts on everyday life. Furthermore, the paper compares whether a board game might achieve this goal more efficiently, or differently, than more traditional ‘open discussion’ exercises. To conduct this study, a board game that present players with cultural dilemmas was designed and developed based on a comparative model of individualistic and collectivistic cultures. The game’s ability to generate discussion and engagement with cross-cultural topics was evaluated and compared with traditional discussion exercises in a series of experimental studies conducted in SFI (Swedish For Immigrants) classrooms. A follow-up survey was also conducted to compare long-term effects between the board game and the traditional discussion exercise. Results indicate that the game benefited participants’ discussions and reflections regarding cultural awareness directly after the game session, and that they retained their attitudes and perceptions of cultural awareness better than participants of the non-game exercise.

Carbon sequestration rates in forest soil can be estimated using the concept of calculable stable remains in decomposing litter. In a case study of Swedish forest land we estimated C-sequestration rates for the two dominant tree species in the forest floor on top of the mineral soil. Carbon sequestration rates were upscaled to the forested land of Sweden with 23 x 106 ha with Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (Karst.) L.). Two different theoretical approaches, based on limit-value for litter decomposition and N-balance for vegetation and SOM gave rates of the same magnitude. For the upscaling, using these methods, 17 000 grids of 5 x 5 km were used. The ‘limit-value approach’ gave a sequestration of 4.8 106 tons of C, annually sequestered in the forest floor, with an average of 180 kg C ha–1 yr–1 and a range from 40 to 410 kg C ha–1 yr–1. The ‘N-balance approach’ gave an average value of c. 96 kg ha–1 yr–1 and a range from –60 to 360 kg ha–1 yr–1. A method based on direct measurements of changes in humus depth over 40 years, combined with C analyses gave an average rate that was not very different from the calculated rates, viz. c. 180 kg ha–1 yr–1 and a range from –20 to 730 kg ha–1 yr–1. These values agree with forest floor C sequestration rate based on e.g. sampling of chronsequences but differ from CO2 balance measurements. The three approaches showed different patterns over the country and regions with high and low carbon sequestration rates that were not always directly related to climate.

Plant litter decomposition plays an important role in forest soil fertility due to nutrient cycling and soil organic matter formation. Litter decomposition, results in return of leaves nutrient to soil and supply of necessary elements for plant growth. In fact, nutrient availability is highly related to litter nutrient dynamic in soil. In this study the nutrient dynamic of Norway spruce litter was investigated in both pure and mixed condition to determine whether its nutrient dynamic is affected by its composition with broad-leaved litters or not. For this reason, Norway spruce litters were treated for 400 days at pure and mixed conditions with Beech (Fagus orientalis lipsky), Alder (Alnus subcordata C.A.Meyer) and Maple (Acer velutinum Boiss.) litters in pure Norway spruce plantation at Lajim site, using litter bag method. The results showed that the non-additive effect of litter composition on dynamic of lignin and manganese was neutral, but on dynamic of nitrogen, potassium and magnesium was positive, whereas on dynamic of calcium was negative. The finding of this study showed that litter mineralization rate of nitrogen in the three treatments of litter composition was higher than the its rate in the pure Norway spruce litter, whereas the mineralization rate of manganese was negative at the end of the study time in all the combinations, except for Norway spruce mixed with beech.

The task of integrating games into an educational setting is a demanding one, and integrating games as a harmonious part of a bigger ecosystem of learning requires teachers to orchestrate a myriad of complex organizational resources. Historically, research on digital game-based learning has focused heavily on the coupling between game designs, previously established learning principles, student engagement, and learning outcomes much to the expense of understanding how games function in their intended educational contexts and how they impact the working processes of teachers. Given the significant investments of time and resources teachers need to make in order to conduct game-based learning activities, the foci of past research is problematic as it obfuscates some of the pressing realities that highly affect games' viability as tools for teaching and learning. This paper aims to highlight the demands that the implementation and use of an educational game in formal educational settings puts on teachers' working processes and skill sets. The paper is based on two case studies in which a researcher collaborated with K-12 teachers to use MinecraftEdu (TeacherGaming LLC, 2012) as a classroom activity over a five-month long period. By documenting both the working processes involved in implementing the game into the classroom environment, as well as the execution of the actual game-based classroom activities, the studies identified a wide variety roles that a teacher needs to take on if they are to make games a central part of a school curriculum. Ultimately, the paper highlights the importance of understanding the constraints under which teachers work, and argues that a better understanding of the contexts in which games are to be used, and the roles teachers play during game-based learning scenarios, is a necessary foundation for improving games' viability as educational tools.

An important factor for success in project-based learning (PBL) is that the involved project groups establish an atmosphere of social interaction in their working environment. In PBL-scenarios situated in distributed environments, most of a group's work-processes are mediated through the use of production-focused tools that are unconcerned with the important informal and social aspects of a project. On the other hand, there are plenty of tools and platforms that focus on doing the opposite and mainly support informal bonding (e.g., Facebook), but these types of environments can be obtrusive and contain distractions that can be detrimental to a group's productivity and are thus often excluded from working environments. The aim of this paper is to examine how a game-based multi-user environment (MUVE) can be designed to support project-based learning by bridging the gap between productivity-focused and social software. To explore this, the authors developed a game-based MUVE which was evaluated in a PBL-scenario. The result of the study revealed several crucial design elements that are needed to make such a MUVE work effectively, and that the acceptance towards game-based MUVEs is high, even with a rudimentary execution.

ABSTRACT Local delivery of antibiotics as prophylaxis for prosthetic joint infections (PJIs) is frequently used during total hip replacement surgery. Morselized bone allograft impregnated with vancomycin and tobramycin (TobraVanc) could provide effective prophylaxis against bacteria commonly associated with PJIs. In this study, the concentrations of antibiotics released by bone allograft impregnated with TobraVanc were determined by using an in vitro bioassay system entailing measuring inhibition zone diameters caused by antibiotic-impregnated bone chips cast in agar against standard curves. The concentrations were determined in samples of TobraVanc-impregnated bone graft taken before and after the application of the bone graft in the patients undergoing acetabular revision surgery. Antibiotic-impregnated bone grafts, sampled prior to application in the patient, delivered antibiotics in the concentration ranges of 730–9,800 mg/L for tobramycin and 1,300–11,000 mg/L for vancomycin. Samples taken after application in the patient released lower concentrations of tobramycin (490–1,900 mg/L; P < 0.01) and vancomycin (3,000–5,100 mg/L; P < 0.05); however, these concentrations remained well above the tobramycin minimum inhibitory concentrations (MICs) for investigated, highly tobramycin-resistant Staphylococcus epidermidis strains (MICs > 256 mg/L). At the tested concentrations, bone graft material mixed with TobraVanc delivered antibiotics in potent concentrations above the MICs for bacteria causing PJIs. Clinical trials are needed to evaluate the efficacy and risk of TobraVanc-impregnated bone graft as a prophylactic agent for patients undergoing hip replacement surgery.IMPORTANCEAntibiotic prophylaxis is the cornerstone of successful joint replacement surgery, reducing the risk for the dreaded complication of prosthetic joint infection (PJI) to roughly 0.5%–2% in standard total hip replacement (THR). In addition to systemic antibiotics, antibiotics added locally have the potential to reduce the PJI risk even further, because of the high concentrations that can be achieved in the joint with limited risk for systemic toxicity. The results in the current study show that bone chips impregnated with a combination of tobramycin and vancomycin (TobraVanc) release antibiotics in concentrations that are potent against common bacteria causing PJIs. Especially in high-risk patients, our results support the prophylactic use of TobraVanc in hip replacement surgery requiring the use of a bone graft. A clinical study testing the efficacy of TobraVanc-impregnated bone graft in reducing the incidence of PJI in hip replacement surgery is currently ongoing (EudraCT: 2021-001708-14).

ObjectTumors in the temporo-mesial region often extend into the insula and vice versa. The present study investigated the results of a surgical strategy that combines principles of tumor and epilepsy surgery.MethodsWe retrospectively analyzed 157 consecutive patients with intrinsic brain tumors in the temporo-mesial region, with varying degrees of extensions into the insula (44 patients, 28.0%). The surgical strategy utilized “anatomy-guided resection,” targeting specific anatomical compartments infiltrated by the tumor (e.g., temporal pole, anterior temporo-mesial region = uncus and hippocampal head, posterior temporo-mesial, insula) rather than treating the tumor as a single mass.ResultsThe most frequent histologies were ganglioglioma CNS WHO grade 1 (55 patients, 35.0%) and IDH1 wildtype glioblastoma (36 patients, 22.9%). Tumor infiltration was most commonly found in the anterior temporo-mesial compartment (145 patients, 92.4%). An anterior temporal lobectomy was part of the surgical strategy in 131 cases (83.4%). Seventy-six patients (48.4%) with drug-resistant epilepsy underwent a formal presurgical epilepsy work-up, including depth electrode placement in three cases. Complete resections were achieved in 117 patients (74.5%), with supramarginal resections performed in 89 cases (56.7%). Four patients experienced non-temporary neurological complications (CTCAE grade 3–5). At 6 months, 127 of 147 assessable patients (86.4%) were free from seizures or auras (ILAE class 1), excluding early postoperative seizures (

The functional properties of Andean grain starches of two species, amaranth (Amaranthus caudatus) and canihua (Chenopodium pallidicaule), three cultivars each, were studied. The study focused on chemical composition, pasting properties, thermal properties, water solubility index (WSI), swelling power (SP), and granule morphology. All amaranth starches were waxy starches, with amylose content less than 5 %, which had some differences in chemical composition (p

Abstract Endovascular thrombectomy (EVT) is the most effective treatment for acute ischemic stroke caused by large vessel occlusion (LVO). Yet, long-term outcome (LTO) and health-related quality of life (HRQoL) in these patients have rarely been addressed, as opposed to modified Rankin scale (mRS) recordings. We analysed demographic data, treatment and neuroimaging parameters in 694 consecutive stroke patients in a maximum care hospital. In 138 of these patients with respect on receipt of written informed consent, LTO and HRQoL were collected over a period of 48 months after EVT using a standardised telephone survey (median 2.1 years after EVT). Age 2 according to the telephone survey more often had complaints regarding mobility, self‐care, and usual activity domains of the HRQoL. Our results underline a sustainable positive effect of effective EVT on the quality of life in LVO stroke. Additionally, predictive parameters of outcome were identified, that may support clinical decision making in LVO stroke.