Rapid Maize Leaf and Immature Ear Responses to UV-B Radiation

Because of their sessile lifestyle, plants have evolved adaptations to environmental factors, including UV-B present in solar radiation. To gain a better understanding of the initial events in UV-B acclimation, we have analyzed a 10 min to 1 h time course of transcriptome responses in irradiated and shielded leaves, and immature maize ears to unravel the systemic physiological and developmental responses in exposed and shielded organs. After 10 min of UV-B exposure, 262 transcripts are changed by at least two-fold in irradiated leaves, and this number doubles after 1 h. Indicative of the rapid modulation of transcription, 130 transcripts are only changed after 10 min. This is true not only in irradiated leaves, but also in shielded tissues. After 10 min of exposure, the overlap in transcriptome changes in irradiated and shielded organs is significant; however, after 30 min of UV-B, there are only two transcripts showing similar UV-B regulation between the three organs; 35 are similarly regulated in both IL and SL. Therefore, at longer irradiation times, there is more specificity of responses, and these are organ-specific. We suggest that early signaling in different tissues may be elicited by common signaling pathways, while at longer exposure times responses become more specific. To identify metabolites as possible signaling molecules, we looked for compounds that increased within 5–90 min in both irradiated and shielded leaves, to explain the kinetics of profound transcript changes within 1 h. We found that myoinositol is one such candidate metabolite; and we also demonstrate that if 0.1 mM myoinositol is applied to leaves of greenhouse maize, some metabolites that are changed by UV-B are also changed similarly by the chemical treatment. Therefore, this metabolite can partially mimic UV irradiation

Species distribution modeling predicts significant declines in coralline algae populations under projected climate change with implications for conservation policy

Funding: This work was funded by a NERC iCASE studentship award to HB, PH, JB, and TF (NE/R007233/1). The Royal Botanic Garden Edinburgh acknowledges funding support from the Scottish Government Rural and Environment Sciences and Analytical Services Division (RESAS). This is a contribution to the Scottish Blue Carbon Forum.Anthropogenic climate change presents a major challenge to coastal ecosystems. Mass population declines or geographic shifts in species ranges are expected to occur, potentially leading to wide-scale ecosystem disruption or collapse. This is particularly important for habitat-forming species such as free-living non-geniculate coralline algae that aggregate to form large, structurally complex reef-life ecosystems with high associated biodiversity and carbon sequestration capability. Coralline algal beds have a worldwide distribution, but have recently experienced global declines due to anthropogenic pressures and changing environmental conditions. However, the environmental factors controlling coralline algal bed distribution remain poorly understood, limiting our ability to make adequate assessments of how populations may change in the future. We constructed the first species distribution model for non-geniculate coralline algae (focusing on maerl-forming species but including crustose coralline algae associated with coralline algal beds) and showed that bathymetry, temperature at the seabed and light availability are the primary environmental drivers of present-day non-geniculate coralline algae distribution. Our model also identifies suitable areas for species presence that currently lack records of occurrence. Large-scale spatial declines in coralline algal distribution were observed under all IPCC Representative Concentration Pathways (ranging from 38% decline under RCP 2.6 up to 84% decline under RCP 8.5), with the most rapid rate of decline up to 2050. Refuge populations that may persist under projected climate change were also identified – informing priority areas for future conservation efforts to maximize the long-term survival of this globally important ecosystem.Publisher PDFPeer reviewe

Self-Selected Versus Standardised Warm-Ups; Physiological Response on 500 m Sprint Kayak Performance

This study investigated the effectiveness of a self-selected (SS) warm-up on 500 m sprint kayak performance (K500) compared to continuous (CON) and intermittent high intensity (INT)-type warm-ups. Twelve nationally ranked sprint kayakers (age 17.7 ± 2.3 years, mass 69.2 ± 10.8 kg) performed CON (15 min at the power at 2 m·mol−1), INT (10 min at 2 m·mol−1, followed by 5 × 10 s sprints at 200% power at VO2max with 50 s recovery at 55% power at VO2max), and SS (athlete’s normal competition warm-up) warm-ups in a randomised order. After a five-minute passive recovery, K500 performance was determined on a kayak ergometer. Heart rate and blood lactate (BLa) were recorded before and immediately after each warm-up and K500 performance. Ratings of perceived exertion (RPE) were recorded at the end of the warm-up and K500. BLa, heart rate, and RPE were generally higher after the INT than CON and SS warm-ups (p 0.05). RPE and changes in BLa and heart rate after the K500 were comparable. There were no differences in K500 performance after the CON, SS, or INT warm-ups. Applied practitioners can, therefore, attain similar performance independent of warm-up type

Effects of Small-Sided Games vs. Conventional Endurance Training on Endurance Performance in Male Youth Soccer Players: A Meta-Analytical Comparison

This paper is in closed access .© 2019, Springer Nature Switzerland AG. Background: Small-sided games have been suggested as a viable alternative to conventional endurance training to enhance endurance performance in youth soccer players. This has important implications for long-term athlete development because it suggests that players can increase aerobic endurance through activities that closely resemble their sport of choice. Objectives: The objectives of this meta-analysis were to compare male youth soccer players’ adaptability to small-sided games vs. conventional endurance training and to establish exercise prescription guidelines for this population. Data Sources: The data sources utilised were Google Scholar, PubMed and Microsoft Academic. Study Eligibility Criteria: Studies were eligible for inclusion if interventions were carried out in male soccer players (aged < 18 years) and compared the effects of small-sided games and conventional endurance training on aerobic endurance performance. We defined small-sided games as “modified [soccer] games played on reduced pitch areas, often using adapted rules and involving a smaller number of players than traditional games”. We defined conventional endurance training as continuous running or extensive interval training consisting of work durations > 3 min. Study Appraisal and Synthesis Methods: The inverse-variance random-effects model for meta-analyses was used because it allocates a proportionate weight to trials based on the size of their individual standard errors and facilitates analysis whilst accounting for heterogeneity across studies. Effect sizes were represented by the standardised mean difference and presented alongside 95% confidence intervals. Results: Seven studies were included in this meta-analysis. Both modes of training were effective in increasing endurance performance. Within-mode effect sizes were both of moderate magnitude [small-sided games: 0.82 (95% confidence interval 0.05, 1.60), Z = 2.07 (p = 0.04); conventional endurance training: 0.89 (95% confidence interval 0.06, 1.72), Z = 2.10 (p = 0.04)]. There were only trivial differences [0.04 (95% confidence interval − 0.36, 0.43), Z = 0.18 (p = 0.86)] between the effects on aerobic endurance performance of small-sided games and conventional endurance training. Subgroup analyses showed mostly trivial differences between the training methods across key programming variables such as set duration (≥ or < 4 min) and recovery period between sets (≥ or < 3 min). Programmes that were longer than 8 weeks favoured small-sided games [effect size = 0.45 (95% confidence interval − 0.12, 1.02), Z = 1.54 (p = 0.12)], with the opposite being true for conventional endurance training [effect size = − 0.33 (95% confidence interval − 0.79, 0.14), Z = 1.39 (p = 0.16)]. Programmes with more than 4 sets per session favoured small-sided games [effect size = 0.53 (95% confidence interval − 0.52, 1.58), Z = 0.98 (p = 0.33)] with only a trivial difference between those with 4, or fewer, sets [effect size = − 0.13 (95% confidence interval − 0.52, 0.26), Z = 0.65 (p = 0.52)]. Conclusions: Small-sided games are as effective as conventional endurance training for increasing aerobic endurance performance in male youth soccer players. This is important for practitioners as it means that small-sided games can allow both endurance and skills training to be carried out simultaneously, thus providing a more efficient training stimulus. Small-sided games offer the same benefits as conventional endurance training with two sessions per week, with ≥ 4 sets of 4 min of activity, interspersed with recovery periods of 3 min, recommended in this population

Aging and Recovery After Resistance-Exercise-Induced Muscle Damage: Current Evidence and Implications for Future Research

Accepted author manuscript version reprinted, by permission, from Journal of Aging and Physical Activity, 2021, 29(3): 544-551, https://doi.org/10.1123/japa.2020-0201. © Human Kinetics, Inc.Aging is anecdotally associated with a prolonged recovery from resistance training, though current literature remains equivocal. This brief review considers the effects of resistance training on indirect markers of muscle damage and recovery (i.e., muscle soreness, blood markers, and muscle strength) in older males. With no date restrictions, four databases were searched for articles relating to aging, muscle damage, and recovery. Data from 11 studies were extracted for review. Of these, four reported worse symptoms in older compared with younger populations, while two have observed the opposite, and the remaining studies (n = 6) proposed no differences between age groups. It appears that resistance training can be practiced in older populations without concern for impaired recovery. To improve current knowledge, researchers are urged to utilize more ecologically valid muscle-damaging bouts and investigate the mechanisms which underpin the recovery of muscle soreness and strength after exercise in older populations

Group versus Individualised Minimum Velocity Thresholds in the Prediction of Maximal Strength in Trained Female Athletes

This study examined the accuracy of di erent velocity-based methods in the prediction of bench press and squat one-repetition maximum (1RM) in female athletes. Seventeen trained females (age 17.8 1.3 years) performed an incremental loading test to 1RM on bench press and squat with the mean velocity being recorded. The 1RM was estimated from the load–velocity relationship using the multiple- (8 loads) and two-point (2 loads) methods and group and individual minimum velocity thresholds (MVT). No significant e ect of method, MVT or interaction was observed for the two exercises (p > 0.05). For bench press and squat, all prediction methods demonstrated very large to nearly perfect correlations with respect to the actual 1RM (r range = 0.76 to 0.97). The absolute error (range = 2.1 to 3.8 kg) for bench press demonstrated low errors that were independent of the method and MVT used. For squat, the favorable group MVT errors for the multiple- and two-point methods (absolute error = 7.8 and 9.7 kg, respectively) were greater than the individual MVT errors (absolute error = 4.9 and 6.3 kg, respectively). The 1RM can be accurately predicted from the load–velocity relationship in trained females, with the two-point method o ering a quick and less fatiguing alternative to the multiple-point method

Fgf receptor 3 activation promotes selective growth and expansion of occipitotemporal cortex

<p>Abstract</p> <p>Background</p> <p>Fibroblast growth factors (Fgfs) are important regulators of cerebral cortex development. Fgf2, Fgf8 and Fgf17 promote growth and specification of rostromedial (frontoparietal) cortical areas. Recently, the function of Fgf15 in antagonizing Fgf8 in the rostral signaling center was also reported. However, regulation of caudal area formation by Fgf signaling remains unknown.</p> <p>Results</p> <p>In mutant mice with constitutive activation of Fgf receptor 3 (Fgfr3) in the forebrain, surface area of the caudolateral cortex was markedly expanded at early postnatal stage, while rostromedial surface area remained normal. Cortical thickness was also increased in caudal regions. The expression domain and levels of Fgf8, as well as overall patterning, were unchanged. In contrast, the changes in caudolateral surface area were associated with accelerated cell cycle in early stages of neurogenesis without an alteration of cell cycle exit. Moreover, a marked overproduction of intermediate neuronal progenitors was observed in later stages, indicating prolongation of neurogenesis.</p> <p>Conclusion</p> <p>Activation of Fgfr3 selectively promotes growth of caudolateral (occipitotemporal) cortex. These observations support the 'radial unit' and 'radial amplification' hypotheses and may explain premature sulcation of the occipitotemporal cortex in thanatophoric dysplasia, a human <it>FGFR3 </it>disorder. Together with previous work, this study suggests that formation of rostral and caudal areas are differentially regulated by Fgf signaling in the cerebral cortex.</p

Di-ureasil hybrids doped with LiBF4: attractive candidates as electrolytes for "Smart Windows"

The sol-gel process has been used to prepare hybrid electrolytes composed of a poly(oxyethylene) (POE)/siloxane hybrid network doped with lithium tetrafluoroborate (LiBF4) with compositions of n between ∞ and 2.5. In this context the lithium salt concentration is expressed in terms of the number of oxyethylene units in the organic component of the network per Li+ ion. Electrolyte samples with n ≥ 20 are thermally stable up to approximately 250 ºC. All the materials synthesized are semi-crystalline: in the composition range n ≥ 15 free crystalline POE exists and at 60 ≥ n ≥ 2.5 evidence of the presence of a crystalline POE/LiBF4 compound has been found. At n = 2.5 this latter crystalline phase coexists with free salt. The room temperature conductivity maximum of this electrolyte system is located at n = 10 (1.5x10-5 S cm-1 at 22 ºC). The electrochemical stability domain of the sample with n = 15 spans about 5.5 V versus Li/Li+. This new series of materials represents a promising alternative to the LiTFSI- and LiClO4-doped POE and POE/siloxane analogues. Preliminary tests performed with a prototype electrochromic device (ECD) comprising the sample with n = 8 as electrolyte and WO3 as cathodically coloring layer are extremely encouraging. The device exhibits switching time around 50 s, an optical density change of 0.13, open circuit memory of about 4 months and high coloration efficiency (106 cm2C-1 in the 3rd cycle).Fundação para a Ciência e a Tecnologi

Observation of three-state nematicity in the triangular lattice antiferromagnet Fe1/3_{1/3} NbS2_2

Nematic order is the breaking of rotational symmetry in the presence of translational invariance. While originally defined in the context of liquid crystals, the concept of nematic order has arisen in crystalline matter with discrete rotational symmetry, most prominently in the tetragonal Fe-based superconductors where the parent state is four-fold symmetric. In this case the nematic director takes on only two directions, and the order parameter in such "Ising-nematic" systems is a simple scalar. Here, using a novel spatially-resolved optical polarimetry technique, we show that a qualitatively distinct nematic state arises in the triangular lattice antiferromagnet Fe$_{1/3}$NbS$_2$. The crucial difference is that the nematic order on the triangular lattice is a Z$_3$, or three-state Potts-nematic order parameter. As a consequence, the anisotropy axes of response functions such as the resistivity tensor can be continuously re-oriented by external perturbations. This discovery provides insight into realizing devices that exploit analogies with nematic liquid crystals.Comment: The main text is 16 pages, including 5 figures and references. Supplementary information is appended at the end of the articl