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Background and Aims: Thallium (Tl) is extremely toxic to all life forms and is an emerging pollutant. Plants in the Brassicaceae family, including edible crops, have an enhanced capacity for Tl accumulation, even from soils with low thallium concentration. The most extreme Tl hyperaccumulator is Biscutella laevigata, capable of attaining >32 000 μg Tl g-1 dry weight (DW) in its leaves., Methods: Biscutella laevigata from a non-metallicolous accession (Feltre, Italy) and a metallicolous accession (Les Malines, France) were subjected to a dosing experiment in hydroponics (0, 5 and 30 μm Tl), followed by synchrotron-based micro-X-ray fluorescence analysis to elucidate tissue- and cellular-level Tl distribution., Key Results: Flow cytometric data on the two accessions showed that the Feltre accession has a genome size twice of that of the Les Malines accession (256 and 125 pg per 2C, respectively), suggesting that they are phylogenetically distant populations. The Feltre accession did not accumulate Tl (125 μg Tl g-1 DW on average in leaves) at the 5 µm Tl dose level, whereas the Les Malines accession had a mean of 1750 μg Tl g-1 DW, with peaks of 24 130 μg Tl g-1 DW, at the 30 µm Tl dose level. At 30 µm Tl, the non-metallicolous accession did not grow, and at 5 µm Tl it showed reduced biomass compared with the metallicolous one. In the Les Malines accession, the synchrotron-based micro-X-ray fluorescence analysis revealed that Tl was localized in the vacuoles of epidermal cells, especially underneath trichomes and in trichome basal cells. Thallium also occurred in solid crystalline deposits (3-5 µm in size, ~40 wt% Tl) that were found mainly in foliar margins and under trichome bases., Conclusions: Biscutella laevigata is an attractive model for studying Tl hypertolerance and hyperaccumulation on account of the extreme expression of this trait and its marked intraspecific variability., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Self-sustaining vegetation in metal-contaminated areas is essential for rebuilding ecological resilience and community stability in degraded lands. Metal-tolerant plants originating from contaminated post-mining areas may hold the key to successful plant establishment and growth. Yet, little is known about the impact of metal toxicity on reproductive strategies, metal accumulation, and allocation patterns at the seed stage. Our research focused on the metal tolerant Atriplex lentiformis. Specifically, we examined the effects of toxic metal(loid) concentration in soils on variability in its reproductive strategies, including germination patterns, elemental uptake, and allocation within the seeds. We employed advanced imaging techniques like synchrotron X-ray fluorescence microscopy (2D scans and 3D tomograms) combined with inductively coupled plasma mass spectrometry to reveal significant differences in metal(loid) concentration and distribution within the seed structures of A. lentiformis from contrasting habitats. Exclusive Zn hotspots of high concentrations were found in the seeds of the metallicolous accession, primarily in the sensitive tissues of shoot apical meristems and root zones of the seed embryos. Our findings offer novel insights into phenotypic variability and metal tolerance and accumulation in plants from extreme environments. This knowledge can be applied to enhance plant survival and performance in land restoration efforts., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The abandoned Allchar Mine in the Republic of North Macedonia is a globally unique deposit with the highest known grades of thallium (Tl) and arsenic (As) mineralization. We aimed to determine the distribution of As and Tl in whole dehydrated shoots of the three Viola taxa using synchrotron micro-X-ray fluorescence analysis. Additionally, soil and plant organ samples were collected from all three Viola taxa at the Allchar site and analysed using inductively coupled plasma-atomic emission spectrometry. Concentrations of Tl were extremely high in all three Viola taxa (up to 58 900 mg kg-1), but concentrations of As were highly variable with V. tricolor subsp. macedonica and V. allchariensis having low As (up to 20.2 and 26.3 mg kg-1, respectively) and V. arsenica having the highest concentrations (up to 381 mg kg-1). The extremely high Tl in all three species is endogenous and not a result of contamination. Arsenic in V. tricolor subsp. macedonica and V. allcharensis is strongly affected by contamination, but not in V. arsenica where it appears to be endogenous. The pattern of As enrichment in V. arsenica is very unusual and coincides with Ca-oxalate deposits and Br hotspots. The results of this study could form the basis for more detailed investigations under controlled conditions, including plant dosing experiments., (© The Author(s) 2023. Published by Oxford University Press.)

Background and Aims: Selenium hyperaccumulator species are of primary interest for studying the evolution of hyperaccumulation and for use in biofortification because selenium is an essential element in human nutrition. In this study, we aimed to determine whether the distributions of selenium in the three most studied hyperaccumulating taxa (Astragalus bisulcatus, Stanleya pinnata and Neptunia amplexicaulis) are similar or contrasting, in order to infer the underlying physiological mechanisms., Methods: This study used synchrotron-based micro-X-ray fluorescence (µXRF) techniques to visualize the distribution of selenium and other elements in fresh hydrated plant tissues of A. racemosus, S. pinnata and N. amplexicaulis., Key Results: Selenium distribution differed widely in the three species: in the leaves of A. racemosus and N. amplexicaulis selenium was mainly concentrated in the pulvini, whereas in S. pinnata it was primarilylocalized in the leaf margins. In the roots and stems of all three species, selenium was absent in xylem cells, whereas it was particularly concentrated in the pith rays of S. pinnata and in the phloem cells of A. racemosus and N. amplexicaulis., Conclusions: This study shows that Astragalus, Stanleya and Neptunia have different selenium-handling physiologies, with different mechanisms for translocation and storage of excess selenium. Important dissimilarities among the three analysed species suggest that selenium hyperaccumulation has probably evolved multiple times over under similar environmental pressures in the US and Australia., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Annals of Botany Company.)

Synchrotron-based micro-X-ray fluorescence analysis (µXRF) is a nondestructive and highly sensitive technique. However, element mapping of rare earth elements (REEs) under standard conditions requires care, since energy-dispersive detectors are not able to differentiate accurately between REEs L-shell X-ray emission lines overlapping with K-shell X-ray emission lines of common transition elements of high concentrations. We aim to test REE element mapping with high-energy interference-free excitation of the REE K-lines on hyperaccumulator plant tissues and compare with measurements with REE L-shell excitation at the microprobe experiment of beamline P06 (PETRA III, DESY). A combination of compound refractive lens optics (CRLs) was used to obtain a micrometer-sized focused incident beam with an energy of 44 keV and an extra-thick silicon drift detector optimized for high-energy X-ray detection to detect the K-lines of yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), and neodymium (Nd) without any interferences due to line overlaps. High-energy excitation from La to Nd in the hyperaccumulator organs was successful but compared to L-line excitation less efficient and therefore slow (∼10-fold slower than similar maps at lower incident energy) due to lower flux and detection efficiency. However, REE K-lines do not suffer significantly from self-absorption, which makes XRF tomography of millimeter-sized frozen-hydrated plant samples possible. The K-line excitation of REEs at the P06 CRL setup has scope for application in samples that are particularly prone to REE interfering elements, such as soil samples with high concomitant Ti, Cr, Fe, Mn, and Ni concentrations., (© The Author(s) 2023. Published by Oxford University Press.)

Visualizing the endogenous distribution of elements within plant organs affords key insights in the regulation of trace elements in plants. Hyperaccumulators have extreme metal(loid) concentrations in their tissues, which make them useful models for studying metal(loid) homeostasis in plants. X-ray-based methods allow for the nondestructive analysis of most macro and trace elements with low limits of detection. However, observing the internal distributions of elements within plant organs still typically requires destructive sample preparation methods, including sectioning, for synchrotron X-ray fluorescence microscopy (XFM). X-ray fluorescence microscopy-computed tomography (XFM-CT) enables "virtual sectioning" of a sample thereby entirely avoiding artefacts arising from destructive sample preparation. The method can be used on frozen-hydrated samples, as such preserving "life-like" conditions. Absorption and Compton scattering maps obtained from synchrotron XFM-CT offer exquisite detail on structural features that can be used in concert with elemental data to interpret the results. In this article we introduce the technique and use it to reveal the internal distribution of hyperaccumulated elements in hyperaccumulator plant species. XFM-CT can be used to effectively probe the distribution of a range of different elements in plant tissues/organs, which has wide ranging applications across the plant sciences., (© The Author(s) 2022. Published by Oxford University Press.)

Background: A lower developmental stage of the postural control system in childhood compared to adolescence and adulthood was reported in numerous studies and suggests differences (i.e., less improvements in children than in adolescents and young adults due to the immature postural control system) during learning a balance task. Therefore, the present study examined the effect practice on learning (i.e., retention and transfer) a balance task in healthy children, adolescents, and young adults., Methods: Healthy children ( n  = 32, 8.5 ± 0.5 years), adolescents ( n  = 30, 14.6 ± 0.6 years), and young adults ( n  = 28, 24.3 ± 3.3 years) practiced balancing on a stabilometer (i.e., to keep the platform as close to horizontal as possible) for 2 days. On the third day, learning was assessed using a retention (i.e., balance task only) and a transfer (i.e., balance task plus concurrent motor interference task) test. The root-mean-square-error (RMSE) was calculated and used as outcome measures., Results: Over the course of practice, significant improvements ( p  < 0.001) were detected in favor of children and young adults. However, neither the retention nor the transfer test showed significant group differences., Conclusion: Our findings indicate that learning a balance task did not seem to be influenced by the developmental stage of the postural control system., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Muehlbauer, Brueckner and Schedler.)

Biscutella laevigata is the strongest known thallium (Tl) hyperaccumulator plant species. However, little is known about the ecophysiological processes leading to root uptake and translocation of Tl in this species, and the interactions between Tl and its chemical analogue potassium (K). Biscutella laevigata was subjected to hydroponics experimentation in which it was exposed to Tl and K, and it was investigated in a rhizobox experiment. Laboratory-based micro-X-ray fluorescence spectroscopy (μ-XRF) was used to reveal the Tl distribution in the roots and leaves, while synchrotron-based μ-XRF was utilised to reveal elemental distribution in the seed. The results show that in the seed Tl was mainly localised in the endosperm and cotyledons. In mature plants, Tl was highest in the intermediate leaves (16,100 μg g -1 ), while it was one order of magnitude lower in the stem and roots. Potassium did not inhibit or enhance Tl uptake in B.laevigata. At the organ level, Tl was localised in the blade and margins of the leaves. Roots foraged for Tl and cycled Tl across roots growing in the control soils. Biscutella laevigata has ostensibly evolved specialised mechanisms to tolerate high Tl concentrations in its shoots. The lack of interactions and competition between Tl and K suggests that it is unlikely that Tl is taken up via K channels, but high affinity Tl transporters remain to be identified in this species. Thallium is not only highly toxic but also a valuable metal and Tl phytoextraction using B. laevigata should be explored., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The molecular biology and genetics of the Ni-Cd-Zn hyperaccumulator Noccaea caerulescens has been extensively studied, but no information is yet available on Ni and Zn redistribution and mobilization during seed germination. Due to the different physiological functions of these elements, and their associated transporter pathways, we expected differential tissue distribution and different modes of translocation of Ni and Zn during germination. This study used synchrotron X-ray fluorescence tomography techniques as well as planar elemental X-ray imaging to elucidate elemental (re)distribution at various stages of the germination process in contrasting accessions of N. caerulescens. The results show that Ni and Zn are both located primarily in the cotyledons of the emerging seedlings and Ni is highest in the ultramafic accessions (up to 0.15 wt%), whereas Zn is highest in the calamine accession (up to 600 μg g-1). The distribution of Ni and Zn in seeds was very similar, and neither element was translocated during germination. The Fe maps were especially useful to obtain spatial reference within the seeds, as it clearly marked the vasculature. This study shows how a multimodal combination of synchrotron techniques can be used to obtain powerful insights about the metal distribution in physically intact seeds and seedlings., (© The Author(s) 2022. Published by Oxford University Press.)

Objective: It has been shown that variable compared to fixed task prioritization during dual task practice more effectively improves motor (i.e., postural control) and cognitive (i.e., memory) performance in older adults. However, it is unclear whether this finding is also valid in young adults. Thus, the present study examined the effect of fixed (allocate equal priority on both tasks) versus variable (vary priority between both tasks) priority during short-term motor-cognitive dual task practice on single and dual task performance in healthy young adults (age range: 20-30 years)., Results: During two days of practice, significant improvements of motor (i.e., balance task: reduced root mean square error; p < 001, η p 2  = .72) and cognitive (i.e., arithmetic task: increased serial three subtractions; p < .001, η p 2  = .78) task performance were observed and that was irrespective of group ("fixed priority" and "variable priority"). Further, the statistical analysis of post-practice single and dual task performance revealed no significant differences between groups, irrespective of task (i.e., motor or cognitive). This indicates that in young as opposed to old adults, single and dual task performance improvements are independent of task prioritization (i.e., fixed or variable priority) during short-term motor-cognitive dual task practice., (© 2022. The Author(s).)

Background: Studies have shown that restricted compared to free arm movement negatively affects balance performance during balance assessment and this is reinforced when the level of task difficulty (e.g., varying stance/walk conditions, sensory manipulations) is increased. However, it remains unclear whether these findings apply to individuals with differences in the development of the postural control system. Thus, we examined the influence of arm movement and task difficulty on balance performance in children, adolescents, and young adults., Methods: Static, dynamic, and proactive balance performance were assessed in 40 children (11.5 ± 0.6 years), 30 adolescents (14.0 ± 1.1 years), and 41 young adults (24.7 ± 3.0 years) using the same standardized balance tests [i.e., one-legged stance (OLS) time with eyes opened/closed and/or on firm/foam ground, 3-m beam (width: 6, 4.5, or 3 cm) walking backward step number, Lower Quarter Y-Balance test (YBT-LQ) reach distance] with various difficulty levels under free vs. restricted arm movement conditions., Results: In all but one test, balance performance was significantly better during free compared to restricted arm movement. Arm by age interactions were only observed for the YBT-LQ and post hoc analyses revealed significantly greater performance differences between free and restricted arm movement, especially, in young adults. Arm by age by task difficulty interactions were found for the OLS and the 3-m beam walking backward test. Post hoc analyses showed significantly greater performance differences between free and restricted arm movement during high vs. low levels of task difficulty and this was more pronounced in children and adolescents., Conclusions: Regardless of age, static, dynamic, and proactive balance performance benefited from arm movements and this was especially noted for youth performing difficult balance tasks., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Muehlbauer, Hill, Heise, Abel, Schumann, Brueckner and Schedler.)

The concurrent execution of two or more tasks simultaneously results in performance decrements in one or both conducted tasks. The practice of dual-task (DT) situations has been shown to decrease performance decrements. The purpose of this study was to investigate the effects of consecutive versus concurrent practice on cognitive and motor task performance under single-task (ST) and DT conditions. Forty-five young adults (21 females, 24 males) were randomly assigned to either a consecutive practice (INT consecutive) group, a concurrent practice (INT concurrent) group or a control (CON) group (i.e., no practice). Both INT groups performed 2 days of acquisition, i.e., practicing a cognitive and a motor task either consecutively or concurrently. The cognitive task required participants to perform an auditory stroop task and the number of correct responses was used as outcome measure. In the motor task, participants were asked to stand on a stabilometer and to keep the platform as close to horizontal as possible. The time in balance was calculated for further analysis. Pre- and post-practice testing included performance assessment under ST (i.e., cognitive task only, motor task only) and DT (i.e., cognitive and motor task simultaneously) test conditions. Pre-practice testing revealed no significant group differences under ST and DT test conditions neither for the cognitive nor the motor task measure. During acquisition, both INT groups improved their cognitive and motor task performance. The post-practice testing showed significantly better cognitive and motor task values under ST and DT test conditions for the two INT groups compared to the CON group. Further comparisons between the two INT groups revealed better motor but not cognitive task values in favor of the INT consecutive practice group (ST: p = 0.022; DT: p = 0.002). We conclude that consecutive and concurrent practice resulted in better cognitive (ST condition) and motor (ST and DT test conditions) task performance than no practice. In addition, consecutive practice resulted in superior motor task performance (ST and DT test conditions) compared to concurrent practice and is, therefore, recommended when executing DT practice schedules., (© 2021. The Author(s).)

Objective: Cross-sectional studies reported increased postural sway during balance tasks with a high (e.g., unipedal stance on foam ground) compared to a low (e.g., unipedal stance on firm ground) level of task difficulty. Therefore, practicing/training balance tasks using high compared to low stimuli seems to be beneficial as it addresses larger adaptive reserves. Thus, the present study was performed to investigate the role of task difficulty during practice on learning a dynamic balance task in healthy young adults., Results: During acquisition, both practice groups ("Easy" or "Difficult" task condition) significantly improved their performance (i.e., time in balance). Further, the statistical analysis of post-practice performance revealed a significant main effect of test (i.e., better performance under easy compared to difficult test conditions, irrespective of group) but not of group. Additionally, the Group × Test interaction did not reach the level of significance, indicating that learning a dynamic balance task did not depend on the practiced task condition.

We report on the manufacturing and testing of the first nanofocusing refractive lenses made of single-crystal silicon carbide. We introduce the fabrication process based on lithography, followed by deep isotropic etching. The lenses were characterized at the energy of 12 keV at the beamline P06 of the synchrotron radiation source PETRA III. A focal spot of 186 nm×275 nm has been achieved with a lens working distance of 29 mm.

Background : Previous studies have reported positive effects of concurrent motor and cognitive task practice compared to motor or cognitive task practice only on dual-task performance in young adults. Knowledge about the effect of motor vs. cognitive task prioritization during practice on dual-task performance remains unclear and has not been investigated in depth so far. Thus, we examined the effects of motor task compared to cognitive task prioritization during dual-task practice on motor-cognitive performance in healthy young adults. Methods : Healthy young adults were randomly assigned to dual-task (DT; i.e., concurrent motor and cognitive practice) or single-task (ST; i.e., motor or cognitive task practice only) practice groups. In DT practice, subjects were instructed to either prioritize the motor or the cognitive task. The motor task required subjects to keep a stabilometer in a horizontal position. The cognitive task involved serial three subtractions. Outcome variables were the root-mean-square error (RMSE) for the motor task and the total number of correct calculations for the cognitive task. All participants practiced for 2 consecutive days under their respective treatment condition and were tested under DT condition 24 h later (i.e., retention on day 3) without providing instructions on task prioritization. Results : Irrespective of prioritization (i.e., prioritize the motor task or the cognitive task), the DT practice groups similarly improved their DT motor and cognitive task performance. The ST groups also improved motor or cognitive performance depending on their respective training contents (i.e., motor practice improved RMSE and cognitive practice improved number of correct calculations but not vice versa). Conclusion : We conclude that DT compared to ST practice is well-suited to improve DT performance, irrespective of task-prioritization. DT but not ST practice resulted in an improved modulation of both domains (i.e., motor and cognitive) during DT performance. Our findings might be explained by freeing up central resources following DT practice that can be used to effectively perform the concurrent execution of motor and cognitive processing demands. However, this process is not further enhanced by the prioritized task domain., (Copyright © 2020 Beurskens, Brueckner and Muehlbauer.)

To improve the prognosis of glioblastoma, innovative radiotherapy regimens are required to augment the effect of tolerable radiation doses while sparing surrounding tissues. In this context, nanoscintillators are emerging radiotherapeutics that down-convert X-rays into photons with energies ranging from UV to near-infrared. During radiotherapy, these scintillating properties amplify radiation-induced damage by UV-C emission or photodynamic effects. Additionally, nanoscintillators that contain high-Z elements are likely to induce another, currently unexplored effect: radiation dose-enhancement. This phenomenon stems from a higher photoelectric absorption of orthovoltage X-rays by high-Z elements compared to tissues, resulting in increased production of tissue-damaging photo- and Auger electrons. In this study, Geant4 simulations reveal that rare-earth composite LaF 3 :Ce nanoscintillators effectively generate photo- and Auger-electrons upon orthovoltage X-rays. 3D spatially resolved X-ray fluorescence microtomography shows that LaF 3 :Ce highly concentrates in microtumors and enhances radiotherapy in an X-ray energy-dependent manner. In an aggressive syngeneic model of orthotopic glioblastoma, intracerebral injection of LaF 3 :Ce is well tolerated and achieves complete tumor remission in 15% of the subjects receiving monochromatic synchrotron radiotherapy. This study provides unequivocal evidence for radiation dose-enhancement by nanoscintillators, eliciting a prominent radiotherapeutic effect. Altogether, nanoscintillators have invaluable properties for enhancing the focal damage of radiotherapy in glioblastoma and other radioresistant cancers., Competing Interests: The authors declare no conflict of interest., (© 2020 The Authors. Published by Wiley‐VCH GmbH.)

Background: The Lower Quarter Y Balance Test (YBT-LQ) has been widely used to register dynamic balance performance in children and adolescents. However, studies evaluating age- and sex-specific normative data to assess and classify YBT-LQ performance for these age-cohorts are missing., Objective: Thus, we investigated YBT-LQ performance in healthy youth to provide age- and sex-specific reference values., Methods: Six-hundred and sixty-nine individuals (286 female, 383 male) aged 10-17 years performed the YBT-LQ with their left and right leg. Normalized maximal reach distances (% leg length) for all three directions (i.e., anterior, posterolateral, posteromedial) and the composite score were calculated. Further, age- and sex-specific percentile values (i.e., 10th to 90th percentile) were computed and plotted., Results: In boys, the oldest age group (16-17 years) performed better than the younger ones (14-15, 12-13, and 10-11 years). In girls, the youngest age group (10-11 years) often achieved better values compared to the 12-13-year olds. Further, 16-17-year old boys compared to the same aged girls showed better YBT-LQ performance in all but one measure (except left leg reach in posterolateral direction). For both sexes, curvilinear shaped curves were detected for percentile values across the reach directions., Conclusions: The generated age- and sex-specific reference values for the YBT-LQ can be used by practitioners to evaluate dynamic balance performance in healthy youth aged 10-17 years., Competing Interests: Declaration of Competing Interest None of the authors has any conflicts of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A manual shoulder-training device may represent an alternative training device to improve symptoms and function in patients with subacromial shoulder pain by strengthening the external rotators. Thus, we examined the effects of a traditional versus an alternative strengthening exercise program on shoulder pain/function and physical performance in individuals with subacromial shoulder pain. Fifty-six adults with subacromial shoulder pain were randomly assigned to a passive control group (CON; n = 20), a traditional training group (TRA; n = 19), or an alternative training group (ALT; n = 17). Both training groups conducted a progressive home-based strengthening exercise program for the external rotators for eight weeks using elastic bands only (TRA group) or in combination with the shoulder-training device (Schulterhilfe®) (ALT group). Pre- and post-training assessment included measures of shoulder pain/function (i.e., shoulder pain and disability index (SPADI)) and physical performance (i.e., shoulder flexibility, maximal isometric strength, and strength endurance). We found significant test × group interactions in most of the investigated variables. Post hoc analyses showed significant training-related improvements for proxies of shoulder pain/function, shoulder flexibility, maximal isometric strength, and strength endurance in favor of the ALT and TRA group in comparison to the CON group. Further, larger and more frequent effects were found for the ALT compared to the TRA group. Measures of shoulder pain/function and physical performance can be significantly improved by both training regimens in individuals with subacromial shoulder pain. However, strength training using elastic bands with the manual shoulder device (ALT group) as compared to elastic bands (TRA group) only was more effective and may thus be a recommendable alternative in order to mitigate subacromial shoulder pain.

Background: In youth, sex-related differences in balance performances have been reported with girls usually outperforming same-aged boys. However, it is not known whether sex also has an influence on learning of a new balance task in primary school-aged children. Therefore, the present study investigated sex-related differences in children learning to maintain balance under dynamic conditions., Methods: Thirty-two children (16 girls, 16 boys) aged 8.5 ± 0.5 years practiced balancing on a stabilometer (i.e., to keep it as horizontal as possible) for seven trials (90 s each) on two consecutive days. Knowledge of results (KR) (i.e., time in balance) was provided after each trial. On day three learning was assessed using a retention test (i.e., balance task only) and a test of automation (i.e., balance plus concurrent motor interference task). Root-mean-square-error (RMSE) was recorded for all trials and used for further analysis., Results: During practicing (Day 1, Day 2) RMSE values significantly decreased over the days ( p  = 0.019, d  = 0.92) and trials ( p  = 0.003, d  = 0.70) in boys and girls. Further, the main effect of sex showed a tendency toward significance ( p  = 0.082, d  = 0.67). On day 3, the girls showed significantly smaller RMSE values compared to boys in the retention ( p  = 0.012, d  = 1.00) and transfer test ( p  = 0.045, d  = 0.74)., Conclusions: Performance increases during the acquisition phase tended to be larger in girls than in boys. Further, learning (i.e., retention and automation) was significantly larger in girls compared to boys. Therefore, practitioners (e.g., teachers, coaches) should supply boys and grils with balance exercises of various task difficulties and complexities to address their diverse learning progress., Competing Interests: Competing interestsThe authors declare that they have no competing interests. TM is an Editorial Board Member of BMC Sports Science, Medicine, and Rehabilitation., (© The Author(s) 2020.)

The fern Pteris vittata has been the subject of numerous studies because of its extreme arsenic hyperaccumulation characteristics. However, information on the arsenic chemical speciation and distribution across cell types within intact frozen-hydrated Pteris vittata fronds is necessary to better understand the arsenic biotransformation pathways in this unusual fern. While 2D X-ray absorption spectroscopy imaging studies show that different chemical forms of arsenic, As(III) and As(V), occur across the plant organs, depth-resolved information on arsenic distribution and chemical speciation in different cell types within tissues of Pteris vittata have not been reported. By using a combination of planar and confocal μ-X-ray fluorescence imaging and fluorescence computed μ-tomography, we reveal, in this study, the localization of arsenic in the endodermis and pericycle surrounding the vascular bundles in the rachis and the pinnules of the fern. Arsenic is also accumulated in the vascular bundles connecting into each sporangium, and in some mature sori. The use of 2D X-ray absorption near edge structure imaging allows for deciphering arsenic speciation across the tissues, revealing arsenate in the vascular bundles and arsenite in the endodermis and pericycle. This study demonstrates how different advanced synchrotron X-ray microscopy techniques can be complementary in revealing, at tissue and cellular levels, elemental distribution and chemical speciation in hyperaccumulator plants.

Hyperaccumulator plants present the ideal model system for studying the physiological regulation of the essential (and potentially toxic) transition elements nickel and zinc. This study used synchrotron X-ray Fluorescence Microscopy (XFM) elemental imaging and spatially resolved X-ray Absorption Spectroscopy (XAS) to elucidate elemental localization and chemical speciation of nickel and zinc in the hyperaccumulators Noccaea tymphaea and Bornmuellera emarginata (synonym Leptoplax emarginata). The results show that in the leaves of N. tymphaea nickel and zinc have contrasting localization, and whereas nickel is present in vacuoles of epidermal cells, zinc occurs mainly in the mesophyll cells. In the seeds Ni and Zn are similarly localized and strongly enriched in the cotyledons in N. tymphaea. Nickel is strongly enriched in the tip of the radicle of B. emarginata. Noccaea tymphaea has an Fe-rich provascular strand network in the cotyledons of the seed. The chemical speciation of Ni in the seeds of N. tymphaea is unequivocally associated with carboxylic acids, whereas Zn is present as the phytate complex. The spatially resolved spectroscopy did not reveal any spatial variation in chemical speciation of Ni and Zn within the N. tymphaea seed. The dissimilar ecophysiological behaviour of Ni and Zn in N. tymphaea and B. emarginata raises questions about the evolution of hyperaccumulation in these species.

Purpose/background: There are a few studies investigating the reproducibility of the Upper Quarter Y Balance Test (YBT-UQ) in adults. However, no study has determined test-retest reliability and the minimal detectable change of the YBT-UQ in adolescents from different age cohorts. The aim of the present study was to establish test-retest reliability and minimal detectable change of the YBT-UQ in a sample of healthy adolescents., Methods: In a school setting, 111 students (59 female, 52 male) aged 12-17 years performed the YBT-UQ twice, separated by one week. Normalized maximal reach distances (% arm length) for all three directions (i.e., medial, inferolateral, superolateral) and the composite score were used as outcome measures. Intraclass correlation coefficient (ICC3,1) and standard error of measurement (SEM) were calculated to assess both relative and absolute test-retest reliability. In addition, the minimal detectable change (MDC95%), an index that is defined as the minimal amount of change in performance that falls outside the measurement error or performance changes due to variability was determined., Results: Irrespective of age cohort, reach arm, and reach direction, the measure of relative reliability ranged from "moderate-to-good" to "excellent" ICC values and the proxy of absolute reliability was rather small (i.e., SEM ≤ 7.6%). The MDC95% needed to identify relevant effects in repeated measurements of the YBT-UQ performance ranged between 4.8% and 21.1%, depending on age, reach arm, and reach direction., Conclusions: The detected values imply that the YBT-UQ is a reliable field test that can be used to detect changes of upper quarter mobility/stability in healthy adolescents aged 12-17 years., Level of Evidence: 2b., Competing Interests: Conflict of interest statement: The authors declare that they have no conflict of interest., (© 2019 by the Sports Physical Therapy Section.)

Background: The sequence of blocked balance training (BT) followed by blocked plyometric training (PT) showed greater improvements in physical performance than vice versa and is explained by a preconditioning effect of BT-related adaptations on subsequent adaptations induced by PT. However, it remains unclear whether beneficial effects can also be induced using alternating instead of blocked BT and PT exercise sequences. Thus, we examined the effects of a blocked versus an alternated sequence of BT and PT on physical performance in trained individuals., Methods: Twenty young soccer players (13 years) were randomly assigned to a blocked ( n  = 10) or an alternated ( n  = 10) intervention group. Both groups trained balance and plyometric exercises for six weeks (two sessions/week). The exercises were conducted in a blocked (three weeks of BT followed by three weeks of PT) or an alternated sequence (weekly change of BT and PT). Assessment of pre- and post-training performance included measures of balance, muscle power, speed, and agility., Results: Mainly significant main effects of Test (i.e., pre- to post-test improvements) were observed for the Y-balance test ( p  ≤ 0.014, 1.3 ≤ Cohen's d  ≤ 1.81), the squat jump ( p  = 0.029, d  = 1.36), the countermovement jump ( p  = 0.002, d  = 2.21), the drop jump ( p  = 0.004, d  = 1.96), the split times/total time over 15-m sprinting ( p  ≤ 0.001, 2.02 ≤  d  ≤ 3.08), and the figure-T agility run ( p  < 0.001, d  = 3.80). Further, tendencies toward significant Test x Group interactions were found for several items of the Y-balance test and for SJ height in favor of the blocked BTPT group., Conclusions: Our results indicate that the combined training of balance and plyometric exercises is effective to improve proxies of physical performance in youth soccer players. In addition, there is a limited advantage in some parameters of balance and muscle power for the blocked as compared to the alternated sequence of BT and PT., Competing Interests: Competing interestsThe authors declare that they have no competing interests. One of the authors, Professor Dr. Thomas Muehlbauer, is an Associate Editor of BMC Sports Science, Medicine, and Rehabilitation.

Two in situ `nanoreactors' for high-resolution imaging of catalysts have been designed and applied at the hard X-ray nanoprobe endstation at beamline P06 of the PETRA III synchrotron radiation source. The reactors house samples supported on commercial MEMS chips, and were applied for complementary hard X-ray ptychography (23 nm spatial resolution) and transmission electron microscopy, with additional X-ray fluorescence measurements. The reactors allow pressures of 100 kPa and temperatures of up to 1573 K, offering a wide range of conditions relevant for catalysis. Ptychographic tomography was demonstrated at limited tilting angles of at least ±35° within the reactors and ±65° on the naked sample holders. Two case studies were selected to demonstrate the functionality of the reactors: (i) annealing of hierarchical nanoporous gold up to 923 K under inert He environment and (ii) acquisition of a ptychographic projection series at ±35° of a hierarchically structured macroporous zeolite sample under ambient conditions. The reactors are shown to be a flexible and modular platform for in situ studies in catalysis and materials science which may be adapted for a range of sample and experiment types, opening new characterization pathways in correlative multimodal in situ analysis of functional materials at work. The cells will presently be made available for all interested users of beamline P06 at PETRA III.

The aim of the present study was to investigate the concurrent validity and the test-retest reliability of an electronic contact mat for drop jump assessment in physically active adults. Seventy-nine young, physically active adults participated in the validity study, and 49 subjects were recruited for the reliability study. The motor task required subjects to perform two-legged drop jumps using drop heights of 24, 43, and 62 cm as well as one-legged drop jumps with the left and right leg using a drop height of 24 cm. Ground contact times were simultaneously quantified with an electronic contact mat, a force plate (i.e., gold standard), and a light-barrier system (another criterion device). Concurrent validity was assessed using intraclass correlation coefficient (ICC), systematic bias, limits of agreement, and linear regression analysis. Test-retest reliability (one week apart) was determined by calculating the ICC, the standard error of measurement (SEM), the coefficient of variation (CV), and Lin´s concordance correlation coefficient (р c ). Further, we determined the minimal detectable change (MDC 95% ). Irrespective of drop height and jump condition, good agreements between testing devices (ICC ≥ 0.95) were shown. Compared to the force plate (-0.6 to 3.1 ms) but not to the light-barrier system (31.4 to 41.7 ms), the contact mat showed low systematic bias values. In terms of test-retest reliability, our analyses showed that the measuring devices are in agreement (ICC: 0.70-0.92; SEM: 8.5-18.4 ms; CV: 3.6-6.4%). Depending on the measurement device, drop height, and jump condition, a MDC 95% value ranging from 23.6 to 50.9 ms represents the minimum amount of change needed to identify practical relevant effects in repeated measurements of drop jump performance. Our findings indicate that the electronic contact mat is a valid and reliable testing device for drop jump assessment from different drop heights in young physically active adults.

Background: Previous research showed changes in amplitude- or time-derived measures of electromyographic (EMG) activity with motor learning. However, an analysis of the EMG spectral content (e.g., via wavelet technique) has not been included in these investigations yet., Objective: The aim of this study was to use conventional, amplitude-derived EMG parameters along with modern, wavelet-based time-frequency EMG measures to assess the effects of motor practice on learning a dynamic balance task., Methods: Nineteen young male adults (mean age: 26 ± 6 years) practiced a dynamic balance task for two days. Delayed retention test was performed on the third day. On a behavioral level, the root-mean-square error (RMSE) of the stability platform angle was calculated and used as outcome measure. On a neuromuscular level, EMG data from the tibialis anterior (TA) and the gastrocnemius medialis (GM) muscle were unilaterally recorded and analysed by calculating the integrated EMG (iEMG) and the EMG intensity (via continuous wavelet transforms)., Results: Two days of practice resulted in significantly improved balance performance (i.e., lower RMSE) and TA/GM activation (i.e., reduced iEMG and EMG intensity) that was still present during the retention test on day 3. There was also evidence of practice-related changes in the EMG intensity pattern as indicated by an intensity shift from higher to lower frequency components., Conclusions: We conclude that motor practice leads to improvements in movement effectiveness as indicated by reduced RMSE and in movement efficiency (i.e., decreased iEMG and EMG intensity, intensity shift). In addition to conventional amplitude-derived EMG parameters, modern, wavelet-based time-frequency EMG measures are appropriate to detect practice-related changes in muscle activation., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In soccer, the dominant leg is frequently used for passing and kicking while standing on the non-dominant leg. Consequently, postural control in the standing leg might be superior compared to the kicking leg and is further enhanced with increasing age (i.e., level of playing experience). Unfortunately, leg differences in postural control are associated with an increased risk of injuries. Thus, we examined differences between limbs in unipedal balance performance in young soccer players at different ages. Performance in the Lower Quarter Y Balance Test (YBT-LQ) of the dominant and non-dominant leg and anthropometry was assessed in 76 young male soccer players (under-13 years [U13]: n = 19, U15: n = 14, U17: n = 21, U19: n = 22). Maximal reach distances (% leg length) and the composite scores were used for further analyses. Statistical analyses yielded no statistically significant main effects of leg or significant Leg × Age interactions, irrespective of the measure investigated. However, limb differences in the anterior reach direction were above the proposed cut-off value of >4 cm, which is indicative of increased injury risk. Further, statistically significant main effects of age were found for all investigated parameters, indicating larger reach distances in older (U19) compared to younger (U13) players (except for U15 players). Although reach differences between legs were non-significant, the value in the anterior reach direction was higher than the cut-off value of >4 cm in all age groups. This is indicative of an increased injury risk, and thus injury prevention programs should be part of the training of young soccer players., Competing Interests: The authors declare no conflict of interest.

Background: The Lower Quarter Y Balance Test (YBT-LQ) has been widely used in the field to assess dynamic balance performance in various populations. However, no study has demonstrated test-retest reliability of the YBT-LQ in adolescents including several age cohorts, even though reliability is necessary to provide repeatable performance data., Objective: Thus, we examined test-retest reliability of the YBT-LQ in healthy adolescents., Methods: In a school setting, 178 secondary school students (93 female, 85 male) in sixth to eleventh grades (11-19 years) performed the YBT-LQ twice, 7 days apart. Normalized maximal reach distances (% leg length) for all three directions (i.e., anterior, posterolateral, posteromedial) and both legs and the composite score were used as outcome measures. Intraclass correlation coefficient (ICC 3,1 ) and standard error of measurement (SEM) were calculated to assess relative and absolute test-retest reliability, respectively. Practical relevance of the YBT-LQ was determined by calculating the minimal detectable change (MDC 95% )., Results: Irrespective of grade, test-retest reliability for all distances reached was predominately "excellent" (i.e., ICC 3,1 > 0.75) and the rather small SEM values ranged from 1.77 to 5.81%. Depending on grade and reach direction, MDC values of 4.90 to 16.10% represent the minimum amount of change needed to identify clinically relevant effects in repeated measurements of the YBT-LQ performance., Conclusions: The observed values suggest that the YBT-LQ is a reliable test and suitable to detect changes of dynamic balance performance in healthy adolescents from grade six to eleven (i.e., aged 11-19 years)., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: In everyday life, people engage in situations involving the concurrent processing of motor (balance) and cognitive tasks (i.e., "dual task situations") that result in performance declines in at least one of the given tasks. The concurrent practice of both the motor and cognitive task may counteract these performance decrements. The purpose of this study was to examine the effects of single task (ST) compared to dual task (DT) practice on learning a dynamic balance task. Methods: Forty-eight young adults were randomly assigned to either a ST (i.e., motor or cognitive task training only) or a DT (i.e., motor-cognitive training) practice condition. The motor task required participants to stand on a platform and keeping the platform as close to horizontal as possible. In the cognitive task, participants were asked to recite serial subtractions of three. For 2 days, participants of the ST groups practiced the motor or cognitive task only, while the participants of the DT group concurrently performed both. Root-mean-square error (RMSE) for the motor and total number of correct calculations for the cognitive task were computed. Results: During practice, all groups improved their respective balance and/or cognitive task performance. With regard to the assessment of learning on day 3, we found significantly smaller RMSE values for the ST motor ( d = 1.31) and the DT motor-cognitive ( d = 0.76) practice group compared to the ST cognitive practice group but not between the ST motor and the DT motor-cognitive practice group under DT test condition. Further, we detected significantly larger total numbers of correct calculations under DT test condition for the ST cognitive ( d = 2.19) and the DT motor-cognitive ( d = 1.55) practice group compared to the ST motor practice group but not between the ST cognitive and the DT motor-cognitive practice group. Conclusion: We conclude that ST practice resulted in an effective modulation of the trained domain (i.e., motor or cognitive) while only DT practice resulted in an effective modulation of both domains (i.e., motor and cognitive). Thus, particularly DT practice frees up central resources that were used for an effective modulation of motor and cognitive processing mechanisms.

Background: A well-learned motor skill is characterized by the efficient activation of muscles that are involved in movement execution. However, it is unclear if practice-related changes in motor performance correlate with those in quantitative markers of muscle activity and if so, whether the association is different with respect to the investigated muscle (i.e., agonist and antagonist) and quantitative myoelectric parameter. Thus, we conducted a systematic review and characterized associations between practice-related changes in motor performance and muscle activity in healthy individuals., Methods: A computerized systematic literature search was performed in the electronic databases PubMed, Web of Science, and SPORTDiscus up to September 2017 to capture all relevant articles. A systematic approach was applied to evaluate the 1670 articles identified for initial review. Studies were included only if they investigated healthy subjects aged 6 years and older and tested at least one measure of motor performance (e.g., error score, movement time) and quantitative muscle activity (i.e., amplitude domain: iEMG [integrated electromyography], RMS [root mean square]; time domain: duration of muscle activity, time to peak muscle activation). In total, 24 studies met the inclusionary criteria for review. The included studies were coded for the following criteria: age, learning task, practice modality, and investigated muscles (i.e., agonist and antagonist). Correlation coefficients for the relationship of motor performance changes with changes in electromyography (EMG) amplitude, and duration were extracted, transformed (i.e., Fisher's z-transformed r z value), aggregated (i.e., weighted mean r z value), and back-transformed to r values. To increase sample size, we additionally extracted pre and post practice data for motor performance and myoelectric variables and calculated percent change values as well as associations between both. Correlations were classified according to their magnitude (i.e., small r ≤ 0.69, medium r ≤ 0.89, large r ≥ 0.90)., Results: Five studies reported correlation coefficients for the association between practice-related alterations in motor performance and EMG activity. We found small associations (range r = 0.015-0.50) of practice-related changes in motor performance with measures of agonist and antagonist EMG amplitude and duration. A secondary analysis (17 studies) that was based on the calculation of percent change values also revealed small correlations for changes in motor performance with agonist (r = - 0.25, 11 studies) and antagonist (r = - 0.24, 7 studies) EMG amplitude as well as agonist (r = 0.46, 8 studies) and antagonist (r = 0.29, 5 studies) EMG duration., Conclusions: Our systematic review showed small-sized correlations between practice-related changes in motor performance and agonist and antagonist EMG amplitude and duration in healthy individuals. These findings indicate that practice-related changes can only partly be explained by quantitative myoelectric measures. Thus, future studies investigating biomechanical mechanisms of practice-related changes in motor performance should additionally include qualitative measures of muscle activity (e.g., timing of muscle activity, level of coactivation) and other biomechanical variables (i.e., kinetics, kinematics).

Calorespirometry is the simultaneous analysis of the rate of heat emission (R q ), O 2 consumption (R O2 ) and CO 2 production (R CO2 ) by living systems such as tissues or organism cultures. The analysis provides useful knowledge about thermodynamic parameters relevant for e.g. biotechnology where parameter based yield maximization (fermentation) is relevant. The determination of metabolism related heat emission is easy and normally done by a calorimeter. However, measuring the amount of consumed O 2 and produced CO 2 can be more challenging, as additional preparation or instrumentation might be needed. Therefore, tunable diode laser absorption spectroscopy (TDLAS) was investigated as an alternative approach for respirometric analysis in order to facilitate the data collection procedure. The method determines by a spectroscopic laser non-invasively CO 2 and O 2 gas concentration changes in the respective vial headspaces. The gathered growth data from Pseudomonas aeruginosa cultured in two different scarce media was used to compute respiratory quotient (RQ) and calorespirometric ratios (CR CO2 [R q /R CO2 ], CR O2 [R q /R O2 ]). A comparison of the computed (experimental) values (for RQ, CR CO2 and CR O2 ) with values reported in the literature confirmed the appropriateness of TDLAS in calorespirometric studies. Thus, it could be demonstrated that TDLAS is a well-performing and convenient way to evaluate non-invasively respiratory rates during calorespirometric studies. Therefore, the technique is definitively worth to be investigated further for its potential use in research and in diverse productive environments., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Tunable diode laser absorption spectroscopy (TDLAS) was evaluated on its potential to detect bacterial growth of contaminated media fill vials. The target was a replacement/ automation of the traditional visual media fill inspection. TDLAS was used to determine non-invasively O 2 and/or CO 2 changes in headspaces of such vials being induced by metabolically active microorganisms. Four different vial formats, 34 microorganisms (inoculation volume<10 cells) and two different media (TSB/FTM) were tested. Applying parallel CO 2 and O 2 headspace measurements all format-organism combinations were detected within <11 days reliably with reproducible results. False negatives were exclusively observed for samples that were intentionally breached with syringes of 0.3mm in diameter. Overall it was shown that TDLAS functionality for a replacement of the visual media fill inspection is given and that investing in further validation and implementation studies is valuable. Nevertheless, some small but vincible challenges remain to have this technology in practical use., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Two methods were investigated for non-invasive microbial growth-detection in intact glass vials as possible techniques for automated inspection of media-filled units. Tunable diode laser absorption spectroscopy (TDLAS) was used to determine microbially induced changes in O2 and CO2 concentrations within the vial headspaces. Isothermal microcalorimetry (IMC) allowed the detection of metabolic heat production. Bacillus subtilis and Streptococcus salivarius were chosen as test organisms. Parameters as robustness, sensitivity, comparability and time to detection (TtD) were evaluated to assess method adequacy. Both methods robustly detected growth of the tested microorganisms within less than 76 hours using an initial inoculum of <10CFU. TDLA turned out to be less sensitive than TDLA and IMC, as some false negative results were observed. Compared to the visual media-fill examination of spiked samples, the investigated techniques were slightly slower regarding TtD. Although IMC showed shorter TtD than TDLAS the latter is proposed for automating the media-fill inspection, as larger throughput can be achieved. For routine use either TDLA or a combination of TDLA and TDLA should be considered. IMC may be helpful for replacing the sterility assessment of commercial drug products before release.

The maternally inherited obligate bacteria Wolbachia is known to infect various lepidopteran insects. However, so far only a few butterfly species harbouring this bacterium have been thoroughly studied. The current study aims to identify the infection status of these bacteria in some of the commonly found butterfly species in India. A total of nine butterfly species belonging to four different families were screened using PCR with Wolbachia-specific wsp and ftsZ primers. The presence of the Wolbachia super group 'B' in the butterflies Red Pierrot, Talicada nyseus (Guerin) (Lepidoptera: Lycaenidae) and Blue Mormon, Papilio polymnestor Cramer (Papilionidae), is documented for the first time in India. The study also gives an account on the lifetime fecundity and female-biased sex ratio in T. nyseus, suggesting a putative role for Wolbachia in the observed female-biased sex ratio distortion.

A case of a young man with myopathy, elevated serum aminotransferase and serum creatinine levels is presented. He had a polymyositis-like-syndrome caused by hashimoto thyroiditis with hypothyroidism. Thyroid hormone replacement therapy led to improvement in both the clinical and laboratory abnormalities. With the established tests for estimating the glomerular filtration rate we cannot determine if there was really a reversible acute renal failure or not.