Part Of Experiment Research Articles

Structural complexity and primary production resistance are coupled in a temperate forest

The capacity of forests to resist structural change and retain material legacies–the biotic and abiotic resources that persist through disturbance–is crucial to sustaining ecosystem function after disturbance. However, the role of forest structure as both a material legacy and feature supporting carbon (C) cycling stability following disturbance has not been widely investigated. We used a large-scale disturbance manipulation to ask whether legacies of lidar-derived canopy structures drive 3-year primary production responses to disturbance. As part of the Forest Resilience Threshold Experiment (FoRTE) in northern Michigan, USA we simulated phloem-disrupting disturbances producing a range of severities and affecting canopy trees of different sizes. We quantified the legacies of forest structure using two approaches: one measuring the change in structure and primary production from pre-to post-disturbance and the second estimating resistance as log transformed ratios of control and treatment values. We found that total aboveground wood net primary production (ANPPw) was similar across disturbance severities as legacy trees rapidly increased rates of primary production. Experiment-wide, the disturbance had limited effects on change in mean structural complexity values; however, high variance underscored large differences in the magnitude and direction of complexity's response at the plot-scale. Plot-scale structural complexity, but not vegetation area index (VAI), resistance strongly predicted ANPPw resistance while temporal VAI and structural complexity changes did not. We conclude that the presence of material legacies in the form of forest structure may affect primary production stability following disturbance and that how legacies are quantified may affect the interpretation of disturbance response.

Determination the levels of total bilirubin, total protein and liver histopathological changes in hepatotoxic rats and the role of Beta vulgaris roots ethanolic extract

The present study was done to investigate the therapeutic efficiency of Beta vulgaris roots ethanolic extract versus N-acetylcysteine (NAC) in overcoming experimentally induced hapatotoxicity in rats by given double maximum therapeutic oral dose of Acetaminophen (N-acetyl-para-aminophenol (APAP). The experiment was performed by two parts: First part was involved the extraction of Beta vulgaris roots by using 90% ethanolic solvent and identification the main phytochemical constituents of Beta vulgaris roots ethanolic extract by GC-MS spectrometry analysis , while the second part of experiment was involved the determination and understand the therapeutic effect of Beta vulgaris roots ethanolic extract on hepatotoxicity induced by Acetaminophen which administered more than the recommended dose in rats. Three treated groups of male albino rats (12 rats each) and the dosing regimen was performed as follows: Each group was dosed (APAP) twice daily of (100 mg/kg) for 14 days as follows dosing regimen: Positive control group: Rats were daily administered Acetaminophen at dose (100 mg/kg) orally twice a day as (50 mg/kg) in the morning and (50 mg/kg) at the evening for 14 days followed by two weeks recovery.

Preference for Type2 Diabetes Therapies in the United States: A Discrete Choice Experiment.

IntroductionType 2 diabetes mellitus (T2DM) is a chronic condition associated with substantial clinical and economic burden. As multiple therapeutic options are available, patient preferences on treatment characteristics are key in T2DM therapeutic decision-making. This study aimed to determine the preferences of US patients with T2DM for therapies recommended for first pharmacologic intensification after metformin.MethodsAs part of a discrete choice experiment, an online survey was designed using literature review and qualitative interview findings. Eligibility was met by US patients with T2DM who were aged 18 years or older with an HbA1c ≥ 6.5%. Anonymized therapy profiles were created from six antidiabetic therapies including oral and injectable semaglutide, dulaglutide, empagliflozin, sitagliptin, and thiazolidinediones.ResultsEligible patients (n = 500) had a mean HbA1c of 7.4%, and a mean BMI of 32.0 kg/m2, the majority of which (72.2%) were injectable-naïve. The treatment characteristic with greatest importance was mode and frequency of administration (35.5%), followed by body weight change (29.2%), cardiovascular event risk (19.1%), hypoglycemic event risk (9.9%), and HbA1c change (6.5%). An oral semaglutide-like profile was preferred by 91.9–70.1% of respondents depending on the comparator agent, and preference was significant in each comparison (p < 0.05); an injectable semaglutide-like profile was preferred by 89.3–55.7% of respondents in each comparison depending on the comparator agent.ConclusionPatients with T2DM in the USA are significantly more likely to prefer oral or injectable semaglutide-like profiles over those of key comparators from the glucagon-like peptide 1 receptor agonist, sodium-glucose cotransporter 2 inhibitor, dipeptidyl peptidase 4 inhibitor, and thiazolidinedione classes.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12325-022-02181-7.

CONCEPT AND EFFICIENCY OF RECREATIONAL AND HEALTHY SWIMMING FOR CHILDREN AGED 3-4 YEARS

Research lies in the theoretical and practical development of three methods of conducting recreational and health-improving swimming lessons for children 3-4 years-old, aimed at optimizing adaptation and developing certain adaptive abilities. The purpose consist in revealing the effectiveness of experimental techniques in the systems of individual and group lessons for children aged 3-4 years. The study was carried out as part of a complex experiment in the period 2015-2020, since the effectiveness of three different training methods was studied and significant factors were identified that determine various experimental teaching methods for children aged 3-4 years. All experimental activities took place based on the pool Lotus Water Energy SRL.

A PROPOSAL FOR A MOBILE SYSTEM OF VEHICLE AND RAIL TRACK DIAGNOSTICS

The proper technical condition of a vehicle and rail track in operation is a key aspect in terms of safety and travel comfort. This issue is of particular importance for operators and managers of rolling stock and rail infrastructure. Currently, many diagnostic systems have been developed to monitor the technical condition of selected vehicle systems or rail track from the viewpoints of both the vehicle and track. This article proposes the use of vibration signals in selected quantitative and qualitative analyses as the main diagnostic parameter. For this purpose, over a dozen vibration measurements were carried out during the normal operation of a freight wagon as part of a so-called passive experiment. Measurement points were located on the axle boxes of the wheelsets. The proposed research methodology served as a basis for comparative analyses of the selected operational cases that were investigated. The most important conclusion from the study is that it is possible to monitor the technical condition of vehicles and tracks in real time on the basis of measurements of vibration accelerations at the vehicle level. This directly increases the service life of rolling stock and optimises operating costs by changing the maintenance strategy to one that takes into account the idea of modern on-board technical diagnostics. Another important aspect is the possibility of the varied use of the proposed measurement system, depending on the purpose of the research, which is also associated with the diagnostician’s experience in processing vibroacoustic signals and the utilisation of simple or complex quantitative and qualitative analyses.

Effects of autonomous first- and last mile transport in the transport chain

In this paper we explore user preferences with respect to autonomous shuttle buses when these operate as a first/last mile feeder mode to the main public transport system. We analyse the extent to which improvements of the first- and last mile public transport, through the use of autonomous door-to-door shuttle services, can be expected to affect the choice of mode for the entire transport chain in comparison with choice of mode for the first- and last mile trip. The campus of the Technical University of Denmark (DTU) was used as a case study site, and pivoted stated choice experiments were developed as part of a real-life experiment where several autonomous buses were operated at the DTU campus. In the experiment, choice tasks were directed to users that specifically used the shuttle service. Our findings indicate that while AV shuttles did indeed attract some existing public transport users, almost no effect on the overall mode shares was observed. This even holds for scenarios where speed and frequency of the buses were improved considerably compared to those of the experimental setup. The paper thereby underlines that while new autonomous driving technologies have the potential to improve first and last mile services for public transport, they will have a limited effect on the overall choice of mode for the entire trip chain in their current form.

Advanced time-lapse processing of continuous DAS VSP data for plume evolution monitoring: Stage 3 of the CO2CRC Otway project case study

Active time-lapse seismic monitoring technology is essential for carbon storage projects due to its ability to track the CO2 plume in space and time. A particularly attractive implementation of this technology is permanent seismic reservoir monitoring (PRM) using permanent sources and receivers, which can track subsurface changes in near-real-time over decades. As the number of source points in such a setup is likely to be limited, repeatability and signal to noise ratio need to be improved by processing all the multiple vintages together rather than separately.We explore the advantages of this approach using a PRM dataset acquired to monitor injection of 15 kt of CO2 into a saline aquifer at the Otway International Test Centre (Australia). The monitoring employs continuous acquisition of multi-well offset VSP using nine permanent sources (surface orbital vibrators) and fibre-optic distributed acoustic sensors installed in five monitoring wells producing a vintage every two days for eighteen months before, during and after the injection.Since data reveals seasonal repeatability variations, mainly created by seasonal variations in precipitation levels, for each monitor, an optimal baseline is the one acquired in the same season. The signal-to-noise ratio is further improved by wavefield decomposition of P and S waves. The consistency of the source signature is improved using Wiener filtering. These algorithms improve the data repeatability from about 15–20% to 10–15% normalised root mean square. The results show the CO2 plume signal on the second day of the injection and subsequent time-lapse changes of a stable CO2 plume created at the same reservoir 650 m up-dip five years earlier as a part of the previous field experiment (Stage 2C) at the site.

Study the hepatoprotective effects and oxidant-antioxidant status of beta vulgaris roots ethanolic extract in hepatotoxic rats induced by acetaminophen

The present study was done to investigate the therapeutic efficiency of Beta vulgaris roots ethanolic extract versus N-acetylcysteine (NAC) in overcoming experimentally induced hapatotoxicity in rats by given double maximum therapeutic dose of Acetaminophen (N-acetyl-para-aminophenol (APAP) or paracetamol®) orally. The experiment was performed by two parts: First part was involved the extraction of Beta vulgaris roots by using 90% ethanolic solvent and detection the main phytochemical constituents of Beta vulgaris roots ethanolic extract and their concentrations% by using spectrophotometry analysis, while the second part of experiment was involved the determination and understand the therapeutic effect of Beta vulgaris roots ethanolic extract on hepatotoxicity induced by Acetaminophen which administered more than the recommended dose in rats. Three treated groups of male albino rats (12 rats each) and the dosing regimen was performed as follows: Each group was dosed (APAP) twice daily of (100 mg/kg B.W.) for 14 days as follows dosing regimen: Positive control group: Rats were daily administered Acetaminophen at dose (100 mg/kg) orally twice a day as (50 mg/kg) in the morning and (50 mg/kg) at the evening for 14 days followed by two weeks recovery.

Diosgenin protects against podocyte injury in early phase of diabetic nephropathy through regulating SIRT6

BackgroundDiabetic nephropathy (DN) is a serious complication of diabetes mellitus. DN is the main cause of end-stage renal disease (ESRD). SIRT6 becomes the important target of DN. Diosgenin (a monomer from Chinese herbs) is probable to bind to SIRT6. PurposeBased on studies presented in the literature on kidney injuries plus screening for the binding effects of the drug to Sirt6, we aimed to carry out the study to assess the effects of diosgenin involved in improving podocyte damage in the early phase of DN.. MethodsDN model was established in spontaneous diabetic db/db mice. Animal experiment was in two parts. The first part includes four groups consisting of control (Con) group, model (Mod) group, low dose of diosgenin (DL) group and high dose of diosgenin (DH) group. The second part includes four groups consisting of control group, model group, DH+OSS_128167 (OSS, inhibitor of SIRT6) group, MDL800 (agonist of SIRT6) group. MPC5 cell line was selected in cell experiment, which was mainly composed of six groups including Con group, palmitic acid (PA) group, PA+DL group, PA+DH group, PA+DH+OSS group, PA+MDL800 group. Some procedures such as transcriptomics, RT-qPCR and so on were used in the study to explore and verify the mechanism. ResultsThe abnormal changes of mesangial matrix expansion, glomerular basement membrane (GBM) thickness, foot process (FP) width, urine albumin/creatinine (UACR), DESMIN, ADRP, NEPHRIN, PODOCIN, SIRT6 in Mod group were alleviated in DH group rather than DL group in the first part of animal experiment. The effect in DH group could be reversed in DH+OSS group and the same effect was observed in MDL800 group in the second part of animal experiment. The same results were also found in cell experiment. Protein level and mRNA expression of pyruvate dehydrogenase kinase 4 (PDK4) and Angiopoietin-like-4 (ANGPTL4) were increased in PA group, which could be alleviated in DH group, MDL800 group rather than DH+OSS group. ConclusionsDiosgenin could protect against podocyte injury in early phase of diabetic nephropathy by regulating SIRT6.

Effect of genotype on the hematological parameter of TETRA-SL and Hungarian Partridge coloured chickens at young age

Indigenous chickens are well known for their dual-purpose function and palatable meat. However, the information on their hematology parameters is lacking and hence hampering the poultry industry production of local breeds. The main objective of this study was to examine the hematological parameters of Hungarian Partridge Coloured hen (HPC) and TETRA-SL (TSL) genotype and determine the hematological reference interval values. This trial was part of the larger experiment where a total of 200 chicks (HPC + TSL) were reared. For this trial the blood samples were obtained from brachial wing veins of 8 chicks of each genotype for blood hematological analysis. The results indicated that some of the hematological parameters such as red blood cells-RBC, white blood cells-WBC, hemoglobin-Hb, hematocrit-Ht, platelets-Plt, lymphocytes-LYM, and granulocytes-GRAN were significantly affected by the genotypes (p &lt; 0.05). The genotype did not affect the mean corpuscular volume-MCV, mean corpuscular hemoglobin-MCH, mean corpuscular hemoglobin concentration-MCHC, and GRAN (p &gt; 0.05). The hematological reference interval values were slightly higher in the TSL genotype compared to HPC chicks. It is concluded that genotype has a significant effect on the hematological parameters. The results from this trial will be help and design the baseline reference values for the HPC genotype which will be useful in assessing the health status of these indigenous chickens.

Evaluating different metrics from the thermal-based two-source energy balance model for monitoring grapevine water stress

Precision irrigation management requires operational monitoring of crop water status. However, there is still some controversy on how to account for crop water stress. To address this question, several physiological, several physiological metrics have been proposed, such as the leaf/stem water potentials, stomatal conductance, or sap flow. On the other hand, thermal remote sensing has been shown to be a promising tool for efficiently evaluating crop stress at adequate spatial and temporal scales, via the Crop Water Stress Index (CWSI), one of the most common indices used for assessing plant stress. CWSI relates the actual crop evapotranspiration ET (related to the canopy radiometric temperature) to the potential ET (or minimum crop temperature). However, remotely sensed surface temperature from satellite sensors includes a mixture of plant canopy and soil/substrate temperatures, while what is required for accurate crop stress detection is more related to canopy metrics, such as transpiration, as the latter one avoids the influence of soil/substrate in determining crop water status or stress. The Two-Source Energy Balance (TSEB) model is one of the most widely used and robust evapotranspiration model for remote sensing. It has the capability of partitioning ET into the crop transpiration and soil evaporation components, which is required for accurate crop water stress estimates. This study aims at evaluating different TSEB metrics related to its retrievals of actual ET, transpiration and stomatal conductance, to track crop water stress in a vineyard in California, part of the GRAPEX experiment. Four eddy covariance towers were deployed in a Variable Rate Irrigation system in a Merlot vineyard that was subject to different stress periods. In addition, root-zone soil moisture, stomatal conductance and leaf/stem water potential were collected as proxy for in situ crop water stress. Results showed that the most robust variable for tracking water stress was the TSEB derived leaf stomatal conductance, with the strongest correlation with both the measured root-zone soil moisture and stomatal conductance gas exchange measurements. In addition, these metrics showed a better ability in tracking stress when the observations are taken early after noon.

Lifetime fatigue response due to wake steering on a pair of utility-scale wind turbines

Quantifying the impacts on turbine loads during wind farm control is an important consideration in assessing power production benefits. Wake steering controls aim to improve total wind farm performance by coordinating the control actions of individual turbines, wherein an upstream turbine is intentionally yawed at an offset angle from the measured wind direction. Consequently, this redirects its wake for improved power production and potentially reduces fatigue loads of the downstream turbines. This paper studies the lifetime fatigue loads associated with wake steering by using utility-scale wind turbine experimental data to conduct an analysis on a pair of wind turbines. This study was part of a large field experiment in which a group of five GE 1.5-MW SLE CWE turbines were selected as targets for conducting wake steering research. A standard loads instrumentation package and data acquisition system were installed on two turbines within the cluster to measure turbine fundamental loads. The time-series databases were used to calculate loads statistics as well as short-term and lifetime damage equivalent loads. Fatigue calculations followed the guidance in Annex H of the International Electrotechnical Commission standard 61400-1, Edition 4. Lifetime fatigue calculation results are presented in this analysis; three methods of assessing lifetime fatigue were used to determine percent difference for blade root moments, main shaft moments, main shaft torque, and tower top torque. For all three fatigue treatments, some components’ lifetime fatigue increases for the controlled turbine; however, the downwind turbine experienced a reduction in lifetime fatigue and combined effect for the turbine pair results in a reduction of fatigue when wake steering controls are applied.

On the Utilization of Dietary Glycerol in Carnivorous Fish—Part II: Insights Into Lipid Metabolism of Rainbow Trout (Oncorhynchus mykiss) and European Seabass (Dicentrarchus labrax)

Glycerol is the by-product of biodiesel production and its utilisation in fish feed has recently gained relevance. As an important metabolic intermediate and structural component of triacylglycerol (TAG), it is still unclear whether its supplementation affects lipid utilisation and/or deposition in different tissues. Accordingly, a set of studies was aimed to evaluate how increasing levels of dietary glycerol (0, 2.5 and 5%) affect lipid synthesis in the liver, muscle and adipose tissue. After a growth trial with rainbow trout (8 weeks) and European seabass (6 weeks) fish were sampled at 6 and 24 h to assess mRNA levels of lipid metabolism-related enzymes. The remaining fish were subjected to a metabolic trial consisting of a 6-day residence in deuterated water (2H2O) for metabolic flux calculations. This study stands as the second part of a broader experiment that also aimed at evaluating the carbohydrate metabolism (Viegas et al., 2022). Dietary supplementation at 5% glycerol significantly increased plasma TAG levels in both species and liver TAG levels in seabass, with no repercussions on the perivisceral fat index. Despite responding as expected in a postprandial setting, only fas and Δ6-fad in trout and Δ6-fad in seabass responded significantly by increasing with the dietary supplementation of glycerol. In trout, the observed differences in the regulation of these enzymes were not reflected in the de novo lipogenic fluxes. The fractional synthetic rates (FSR) were overall low in all tissues with an average of 0.04, 0.02 and 0.01% d–1, for liver, muscle and perivisceral fat, respectively. In seabass on the other hand, and despite increased mRNA levels in Δ6-fad, the overall lipid profile in the liver muscle and perivisceral fat was higher in MUFA at the expense of lower PUFA. Moreover, glycerol supplementation altered the lipogenic capacity of seabass with hepatic fractional synthetic rates for TAG-bound FA increasing with increasing glycerol levels (0.32 ± 0.18, 0.57 ± 0.18, and 0.82 ± 0.24 for 0%, 2.5% and 5% glycerol supplementation, respectively). The findings of the present study suggest that supplementation up to 2.5% of glycerol did not severely impact the lipid metabolism nor increased lipogenic potential in liver, muscle and perivisceral fat accumulation.

Predicting Verbal Learning and Memory Assessments of Older Adults Using Bayesian Hierarchical Models.

Verbal learning and memory summaries of older adults have usually been used to describe neuropsychiatric complaints. Bayesian hierarchical models are modern and appropriate approaches for predicting repeated measures data where information exchangeability is considered and a violation of the independence assumption in classical statistics. Such models are complex models for clustered data that account for distributions of hyper-parameters for fixed-term parameters in Bayesian computations. Repeated measures are inherently clustered and typically occur in clinical trials, education, cognitive psychology, and treatment follow-up. The Hopkins Verbal Learning Test (HVLT) is a general verbal knowledge and memory assessment administered repeatedly as part of a neurophysiological experiment to examine an individual’s performance outcomes at different time points. Multiple trial-based scores of verbal learning and memory tests were considered as an outcome measurement. In this article, we attempted to evaluate the predicting effect of individual characteristics in considering within and between-group variations by fitting various Bayesian hierarchical models via the hybrid Hamiltonian Monte Carlo (HMC) under the Bayesian Regression Models using ‘Stan’ (BRMS) package of R. Comparisons of the fitted models were done using leave-one-out information criteria (LOO-CV), Widely applicable information criterion (WAIC), and K-fold cross-validation methods. The full hierarchical model with varying intercepts and slopes had the best predictive performance for verbal learning tests [from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study dataset] using the hybrid Hamiltonian-Markov Chain Monte Carlo approach.

Influence of Natural Convection and Volume Change on Numerical Simulation of Phase Change Materials for Latent Heat Storage

For the numerical simulation of a heat storage based on phase change materials (PCMs) an enhanced model is presented, considering the physical effects of convection flow in the liquid phase as well as the volume change during phase change. A modified heat capacity is used to realize the phase change. The phase change material is initially defined as a liquid with temperature-dependent material properties. A volume force is added to the Navier-Stokes equations to allow a circulating flow field in the liquid phase and prevent flow motion in the solid phase. The volume change is implemented with the Arbitrary Lagrangian-Eulerian method. A laboratory phase change experiment was performed using the PCM RT42 with a melting temperature of 42 °C. The laboratory experiment was calculated numerically using the enhanced model to evaluate the numerical model and to investigate the influence of the simulation parameters on the thermal behavior of the PCM. The thermal conductivity is determined as the main influencing parameter. A good agreement of the simulated melting front throughout a major part of the laboratory experiment has been shown. COMSOL Multiphysics provides a default model for phase change, which neglects convection flow and volume change. Compared to the default model, the enhanced model achieves more accurate results but requires more computational cost for complex latent heat storage systems. Using the default model without convection can be reasonable, considering that the heat storage design is either over-dimensioned or a suitable correction factor must be applied.

Seed nano-priming with Zinc Oxide nanoparticles in rice mitigates drought and enhances agronomic profile.

All cereal crops, particularly rice are perpetually affected due to drastic climatic changes which triggers different stressors resulting in food shortage scenarios across the globe. In modern era, application of nanotechnology holds the pledge in combating the climate change mediated environmental stressors through nanomaterials such as pesticides, nano-biosensors, nano-clays and nano-seed priming technologies. Current study is a part of experiment conducted to comprehend the behaviour of rice plants raised from Zinc Oxide nanoparticles (ZnONPs) primed seeds under the water shortage environment. The seed priming treatment concentrations included 0, 5, 10, 15, 25 and 50 ppm. In the experimental results an increase in plant height, total chlorophyll contents, plant fresh and dry weights was obtained by use of seed priming with ZnONPs. The study results proved that seed priming with 25ppm of ZnONPs increased seed and straw yield with value of 85.333 and 123.333, respectively under water deficit environment. The analysis depicted that 25 ppm has been found more suitable for increasing the 1000 paddy weight of rice plants under both well irrigated and water shortage conditions. Seed priming with ZnONPs results in 53% reduction in MDA contents of water stressed rice plants Drought stress leads to reduction in plant height by 31%, plant fresh weight by 22% and plant dry weight by 28%. Seed priming treatments imparted in current study show significance increase in plant biomass. Priming with ZnONPs further enhances the levels of proline amino acid facilitating the plant to combat water shortage stress. A further elevation in activities of SOD, CAT and POD takes place in rice plants raised from ZnONPs primed seeds by 11%, 13% and 38%, respectively. An elevation in activities of antioxidant enzymes was found and the levels of oxidative stress indicators decreased upon seed priming with ZnONPs. Furthermore the yield characteristics such as panicle length, number of tillers, paddy yield and straw yield of the rice plants raised through ZnONPs primed seeds enhanced. The ZnONPs at concentration of 25 ppm proved optimum in alleviating drought induced damages. It can be inferred that seed pre conditioning with ZnONPs is helpful in increasing yield attributes under the water shortage environment.

Changes in the direction of the diversity–productivity relationship over 15 years of stand development in a planted temperate forest

Abstract Experiments manipulating diversity in both forests and grasslands have often observed a positive diversity–productivity relationship (DPR) which tends to strengthen during plant community development. This pattern is generally attributed to an increase in niche complementarity or facilitation. Most analyses do not examine species dominance and density, which also change over time. Moreover, how neighbourhood‐scale interactions among tree species affect the DPR is not well‐understood. We analysed growth and mortality data from the Simplex experiment, a part of the BIOTREE tree diversity experiment. Simplex consists of 36 plots each planted with four common and commercially important tree species to create a gradient of tree species evenness at two tree densities (6667 and 3556 trees ha−1). We test whether: (a) the effect of evenness on total above‐ground biomass productivity increase with stand development (year), (b) the effect of evenness on productivity is stronger in dense plots; and (c) intraspecific competition from neighbours negatively affect the growth of dominant species more strongly compared to co‐dominant species, and whether this negative effect is stronger in denser plots. The direction of DPR was initially negative because the fast‐growing long‐lived pioneer Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) dominated. However, with time, shade‐tolerant Norway spruce (Picea abies [L.] Karst.) and European beech (Fagus sylvatica L.) increased in abundance (by biomass), and the relationship between evenness and biomass increment changed from negative to positive in high‐density plots. Neighbourhood analyses revealed that for Douglas fir and Norway spruce, conspecifics reduced individual growth rates across density levels and years. Synthesis. We observed a shift in the diversity–productivity relationship over 15 years in our experiment. Over time, increasing intraspecific competition limited the increment of the abundant Douglas fir in uneven plots, and a persistent increase in the abundance (by biomass) of shade‐tolerant Norway spruce and European beech in even plots led to a higher community biomass increment, which led to a positive DPR. Emergence of a positive DPR in temperate forest plantations requires significant time and is importantly promoted by diversity at the neighbourhood scale (intimate mixtures) as well as higher density planting.

Multi-disciplinary investigation of the hydraulic-mechanically driven convergence behaviour: CD-A twin niches in the Mont Terri Rock Laboratory during the first year

To enable safe geological storage of high-level radioactive waste, a comprehensive understanding of the overall system must include relevant physical processes, geological and geotechnical boundary conditions. In the Mont Terri Rock Laboratory (Switzerland) the Cyclic Deformation (CD-A) experiment has been established with the excavation of the two twin niches in the year 2019. To study the impact of the different climatic conditions on the hydraulic and mechanical processes in the claystone, an extensive investigation program has been carried out. As part of the CD-A experiment, we present here a multidisciplinary interpretation including geological characterisation, geodetic and geotechnical measurements, numerical modelling and visualisation techniques. The period under consideration runs between September 2019 and March 2021. Geological mappings illustrate different zones of tectonically induced faulted rock in the sandy facies of the Opalinus Clay and laserscans conducted at regular intervals show small convergence of the niches. While the deformation around the open niche tends to continue, extensometer measurements around the closed twin indicate a reduced deformation after the first months. First coupled hydraulic–mechanical simulations demonstrate that the numerical approach is capable of reproducing the hydro-mechanical behaviour qualitatively, including the extent of the desaturated zone. The application of state-of-the-art visualisation techniques allows simultaneous evaluation and comparison of geological features, measurements and simulation results. This holistic approach – discussed here exemplary for the mechanical effects – provides a valuable basis for the rating of the impact of geologic structures, material heterogeneities, and climatic conditions on the Opalinus Clay. Thus, it can be a valuable component for the safe construction and operation of a repository and for the long term safety assessment.

Deadbug Bridging Performance in 6- to 15-Year-Old Competitive Alpine Skiers-A Cross-Sectional Study.

Simple SummaryIn competitive alpine skiing, a stable trunk plays an important role in increasing performance and preventing injuries. The aim of the present study was to investigate the ability to stabilize the trunk during so-called deadbug bridging (DBB) exercises, a stabilizing, dynamic movement task in the supine position with the pelvis lifted and unilateral leg raising, in 6- to 15-year-old skiers. Trunk stabilization performance was better in female skiers of the under 15-year (U15) category than in their male counterparts, whereas there was no sex difference at ages under 10 years (U10). The only potential confounder when testing youth skiers revealed being body height, but only in female U10 skiers. In summary, this study provided sport-specific normative reference data that may be of equal interest to both researchers and sport practitioners.In competitive alpine skiing, a superior antirotation and rear-chain stabilization capacity is essential to constantly remain in dynamic equilibrium while skiing and to counteract the ski-specific adverse loading patterns of the back. As such, skiers’ trunk stabilization performance during deadbug bridging (DBB) exercises has been shown to be associated with both skiing performance and overuse complaints of the lower back in skiers under 16 years of age (U16). However, to date, little is known about the corresponding stabilization abilities in younger skiers, i.e., 6- to 15-year-old skiers. As part of a biomechanical field experiment during a national off-snow fitness competition, a total of 101 youth competitive alpine skiers were tested with respect to their trunk stabilization performance during DDB exercise. The maximum contralateral displacement of the pelvic drop during leg lift (DBBdisplacement) was quantified using reflective markers and a motion capture system (Vicon, Oxford, UK). Potential age group and sex differences in DBBdisplacement were assessed using analysis of variance (ANOVA) at p < 0.05. Within each subgroup, the associations of DBBdisplacement with age, anthropometrics and maturity offset were analysed using Pearson’s correlation (p < 0.05). Female skiers under 15 years of age (U15) showed better DBB performance than male U15 skiers, while there was no sex difference at the under 10-year (U10) level. In female U10 skiers, DBBdisplacement was moderately associated with body height, while in all other subgroups, no confounding associations with anthropometrics or biological maturation were found. Biomechanically quantifying DBB performance may be considered a feasible and nonconfounded screening test approach in young skiers older than 6 years. Body height may represent a confounding bias in exclusively the U10 female skier cohort and, therefore, should be considered when interpreting the test results. In summary, this study provided sport-specific normative reference data that may be of equal interest to both researchers and sport practitioners.

Bimodal distribution of size-resolved particle effective density: results from a short campaign in a rural environment over the North China Plain

Abstract. Effective density is one of the most important physical properties of atmospheric particles. It is closely linked to particle chemical composition and morphology and could provide special information on particle emissions and aging processes. In this study, size-resolved particle effective density was measured with a combined differential mobility analyzer–centrifugal particle mass analyzer–condensation particle counter (DMA–CPMA–CPC) system in autumn 2019 as part of the Multiphase chemistry experiment in Fogs and Aerosols in the North China Plain (McFAN). With a newly developed flexible Gaussian fit algorithm, frequent (77 %–87 %) bimodal distribution of particle effective density is identified, with a low-density mode (named sub-density mode) accounting for 22 %–27 % of the total number of observed particles. The prevalence of the sub-density mode is closely related to fresh black carbon (BC) emissions. The geometric mean for the main density mode (ρ‾eff,main) increases from 1.18 ± 0.10 g cm−3 (50 nm) to 1.37 ± 0.12 g cm−3 (300 nm) due to a larger fraction of high-density components and a more significant restructuring effect at large particle sizes but decreases from 0.89 ± 0.08 g cm−3 (50 nm) to 0.62 ± 0.12 g cm−3 (300 nm) for the sub-density mode (ρ‾eff,sub), which could be mainly ascribed to the agglomerate effect of BC. ρ‾eff,main and ρ‾eff,sub show similar diurnal cycles with peaks in the early afternoon, mainly attributed to the increasing mass fraction of high material density components associated with secondary aerosol production, especially of secondary inorganic aerosol (SIA). To investigate the impact of chemical composition, bulk particle effective density was calculated based on measured chemical composition (ρeff,ACSM) and compared to the average effective density at 300 nm (ρ‾eff,tot,300nm). The best agreement between the two densities is achieved when assuming a BC effective density of 0.60 g cm−3. The particle effective density is highly dependent on SIA and BC mass fractions. The influence of BC on the effective density is even stronger than SIA, implying the importance and necessity of including BC in the estimate of effective density for ambient particles.