A survey of elite and pre-elite athletes’ perceptions of key support, lifestyle and performance factors

Background Success at the elite level in sport is often attributed to physical prowess, technical skill, and mental attitude. However, underpinning these factors are various lifestyle, support and social factors that may contribute to successful performance, but which may be absent from athlete development programs. Methods An online survey was used to investigate athlete perceptions of lifestyle practices and support services amongst 135 Australian Olympic, Paralympic, National, and state-level athletes across 25 Olympic sports. Results International athletes perceived psychological skills and attributes, along with strong interpersonal relationships as vital to their success, and they also rated ‘Recovery practices’ as very important and made extensive use of available support services. These athletes also indicated that they would have liked access to these services earlier in their careers, a wish that was reiterated by the sub-elite athletes. Furthermore, athletes wanted greater knowledge, mentoring, and autonomy earlier in their careers, and the importance of ‘athlete wellbeing’ as well as ‘athletic performance’ was evident in a number of contexts. Conclusions An athlete development system into which these are included may assist in generating an environment that facilitates athlete success, repeated podium performances, retain athletes in high-performance sport for longer, encourage human-flourishing, wellbeing and smooth transitions for retiring athletes.

Smooth-Transition Simple Digital PWM Modulator for Four-Switch Buck-Boost Converters

This paper proposes a simple, hardware-efficient digital pulse width modulator for a 4SBB that enables operation in Buck, Boost, and Buck+Boost modes, achieving smooth transitions between the different modes. The proposed modulator is simulated using Simulink and experimentally demonstrated using a 500 W 4SBB converter with 24 V input voltage and 12–36 V output voltage range.

Towards seamless irradiance nowcasting on intrahour to intraday scales using all-sky and satellite imagery

<p align="justify">Photovoltaics (PV) power generation depends on atmospheric conditions and especially cloudiness causes strong fluctuations. Accurate nowcasting of the cloud situation and resulting solar irradiance for the next minutes and hours is thus essential for successful integration of PV power plants into the electricity grid. Ground based all-sky imagers allow for spatial and temporal high resolution snapshots of the cloud situation at the position of the plant at low costs. However, the limited area of the sky visible limits the possible forecast time when using cloud motion extrapolation. Commonly used consumer grade cameras further on do not easily allow for elaborate retrieval of cloud optical characteristics necessary for quantitative irradiance forecasts. In contrast, Meteosat satellite data allows for large spatial coverage and estimation of cloud optical properties suitable for intraday nowcasting but with lower spatial and temporal resolution. Due to the different resolutions, joint beneficial usage of all-sky and satellite imagery as well as smooth transitions between all-sky and satellite based nowcasting are challenging.</p> <p align="justify">This work demonstrates the possibility of supplementary usage of satellite imagery for all-sky image based intrahour nowcasting using a simplified 4D-Var assimilation framework. The use of satellite imagery also allows for a seamless transition from intrahour to intraday irradiance nowcasting.</p> <p align="justify">For the intrahour period, all-sky images from a pair of imagers are evaluated to obtain stereo cloud heights, cloud motion vectors and cloud masks utilizing a synthetic clearsky library. This data is combined into a 2D cloud mask advection model using a simplified 4D-var assimilation scheme. Data from multiple imagers and timesteps as well as satellite derived irradiance maps can be put to use within the assimilation framework and as boundary condition.<br />Within this work, satellite based irradiance maps are computed using methods based on Sirch (2018). Cloud optical properties are retrieved from Meteosat Second Generation (MSG) images with the APICS (Bugliaro et al. 2011) and CiPS (Strandgren et al., 2017) algorithms. These are horizontally advected using two separate layers for thin cirrus and thicker clouds, which are then input to radiative transfer calculations. Resulting irradiance maps can be used for the intrahour assimilation as well as seamlessly following intraday nowcasts.</p> <p align="justify"> </p> <p align="justify">References:</p> <p>Sirch, Tobias (2018): Multi-resolution nowcasting of clouds and DNI with MSG/SEVIRI for an optimized operation of concentrating solar power plants. Dissertation, LMU München: Faculty of Physics</p> <p>Bugliaro, L., Zinner, T., Keil, C., Mayer, B., Hollmann, R., Reuter, M., and Thomas, W.: Validation of cloud property retrievals with simulated satellite radiances: a case study for SEVIRI, Atmos. Chem. Phys., 11, 5603–5624,2011.</p> <p align="justify">Strandgren, J., Bugliaro, L., Sehnke, F., and Schröder, L.: Cirrus cloud retrieval with MSG/SEVIRI using artificial neural networks, Atmos. Meas. Tech., 10, 3547–3573, 2017.</p>

Continuality of Language Levels Hierarchy

The author points out that the structure of language levels system is still a crucial linguistic problem, that research in this field is far from being completed and that there is a need for further improvement of the current models of language levels hierarchy. The author sets out his reflections that sprang up from striving to eliminate some contradictions in the existing models of the language levels system. Applying the method of comparative analysis, elements of the model theory and linguistic systemology, using the Russian language material supplemented by some sporadic examples from other languages, the researcher puts forward a number of amendments to the existing models of the language levels hierarchy – amendments intended for riddance of the above-mentioned contradictions. The author argues in favor of merging the morphological and lexical levels, as well as the level of syntax and that of utterances, and offers insertion of the word combinations level at which language units and speech units co-exist, forming two intersecting sub-levels. The expediency of combining the system of language levels and that of speech levels into a common speech-language space has been proved. Using the empirical material, the author demonstrates the level boundaries blurring and existence of inter-level gaps, which contain hybrid units that have typological features of both the upper level and the lower level. The following conclusion is drawn: the speech-language hierarchy must be schematically presented not so much a column of hard and fast lines as a linguistic continuum with smooth transitions between the levels.

Topography-based local spherical Voronoi grid refinement on classical and moist shallow-water finite-volume models

Locally refined grids for global atmospheric models are attractive since they are expected to provide an alternative to solve local phenomena without the requirement of a global high-resolution uniform grid, whose computational cost may be prohibitive. Spherical centroidal Voronoi tessellation (SCVT), as used in the atmospheric Model for Prediction Across Scales (MPAS), allows a flexible way to build and work with local refinement. In addition, the Andes Range plays a key role in the South American weather, but it is hard to capture its fine-structure dynamics in global models. This paper describes how to generate SCVT grids that are locally refined in South America and that also capture the sharp topography of the Andes Range by defining a density function based on topography and smoothing techniques. We investigate the use of the mimetic finite-volume scheme employed in the MPAS dynamical core on this grid considering the nonlinear classic and moist shallow-water equations on the sphere. We show that the local refinement, even with very smooth transitions from different resolutions, generates spurious numerical inertia–gravity waves that may even numerically destabilize the model. In the moist shallow-water model, wherein physical processes such as precipitation and cloud formation are included, our results show that the local refinement may generate spurious rain that is not observed in uniform-resolution SCVT grids. Fortunately, the spurious waves originate from small-scale grid-related numerical errors and can therefore be mitigated using fourth-order hyperdiffusion. We exploit a grid geometry-based hyperdiffusion that is able to stabilize spurious waves and has very little impact on the total energy conservation. We show that, in some cases, the clouds are better represented in a variable-resolution grid when compared to a respective uniform-resolution grid with the same number of cells, while in other cases, grid effects can affect the cloud and rain representation.

Paths and pathways that generate cell-type heterogeneity and developmental progression in hematopoiesis

Mechanistic studies of Drosophila lymph gland hematopoiesis are limited by the availability of cell-type specific markers. Using a combination of bulk RNA-Seq of FACS-sorted cells, single cell RNA-Seq, and genetic dissection, we identify new blood cell subpopulations along a developmental trajectory with multiple paths to mature cell types. This provides functional insights into key developmental processes and signaling pathways. We highlight metabolism as a driver of development, show that graded Pointed expression allows distinct roles in successive developmental steps, and that mature crystal cells specifically express an alternate isoform of Hypoxia-inducible factor (Hif/Sima). Mechanistically, the Musashi-regulated protein Numb facilitates Sima-dependent non-canonical, and inhibits canonical, Notch signaling. Broadly, we find that prior to making a fate choice, a progenitor selects between alternative, biologically relevant, transitory states allowing smooth transitions reflective of combinatorial expressions rather than stepwise binary decisions. Increasingly, this view is gaining support in mammalian hematopoiesis.

Classical and Quantum Gases on a Semiregular Mesh

The main objective of a statistical mechanical calculation is drawing the phase diagram of a many-body system. In this respect, discrete systems offer the clear advantage over continuum systems of an easier enumeration of microstates, though at the cost of added abstraction. With this in mind, we examine a system of particles living on the vertices of the (biscribed) pentakis dodecahedron, using different couplings for first and second neighbor particles to induce a competition between icosahedral and dodecahedral orders. After working out the phases of the model at zero temperature, we carry out Metropolis Monte Carlo simulations at finite temperature, highlighting the existence of smooth transitions between distinct “phases”. The sharpest of these crossovers are characterized by hysteretic behavior near zero temperature, which reveals a bottleneck issue for Metropolis dynamics in state space. Next, we introduce the quantum (Bose-Hubbard) counterpart of the previous model and calculate its phase diagram at zero and finite temperatures using the decoupling approximation. We thus uncover, in addition to Mott insulating “solids”, also the existence of supersolid “phases” which progressively shrink as the system is heated up. We argue that a quantum system of the kind described here can be realized with programmable holographic optical tweezers.

Transition from the Taylor rule to the zero lower bound

This paper examines the Taylor rule in the context of United States monetary policy since 1965, particularly with respect to the zero-lower-bound era of the federal funds rate from 2009 to 2016. A nonlinear Taylor rule is developed which features smooth transitions in the first two moments of the federal funds rate. This flexible specification is found to usefully capture observed nonlinearity, while accounting for the well-documented structural changes in monetary policy formation at the Federal Reserve in the last 50 years, and especially in the recent zero-lower-bound era.

A Survey of Lifestyle and Performance Factors of Elite and Pre-Elite Athletes

Background Success at the elite level in sport is often attributed to physical prowess, technical skill, and mental attitude. However, underpinning these factors are various lifestyle and social influences that further contribute to successful performance, but which may be absent from athlete development programs. Methods An online survey was used to investigate athlete perceptions of lifestyle practices and support services amongst 135 Australian Olympic, Paralympic, National, and state-level athletes across 25 Olympic sports. Results International athletes perceived psychological skills and attributes, along with strong interpersonal relationships as vital to their success, and they also rated ‘Recovery practices’ as very important. Athletes wanted greater knowledge, mentoring, and autonomy earlier in their careers. Conclusions An athlete development system into which these are included may assist in generating an environment to facilitate repeated podium performances, retain athletes in high-performance sport for longer, encourage human-flourishing and smooth transitions for retiring athletes.