Germination of chapolin® tomato using different substrates and shading.

Vegetable production is a great source of Brazilian income and has been widely studied. Thus, the formation of substrates that promote better seedling cultivation conditions and the amount of light received become important research factors for better results in the final product. The use of coconut fiber (FC) has been widely used in the production of seedlings of many vegetable species. Thus, the objective of this work was to evaluate the interaction of different substrate compositions and different shading levels in the germination of tomato of the Chapolin® variety. For this, the experiment was conducted at three different shading levels (70 and 90%) and 5 different mixtures of substrates with different concentrations of clay (A) and coconut fiber (FC): T1 (100% A), T2 (80 % A + 20% FC), T3 (60% A + 40% FC), T4 (40% A + 60% FC) and T5 (100% FC), in a completely randomized design, with four replications for each level of shading and substrate concentration. The beginning of germination occurred on the seventh day after sowing (DAS) and lasted until the fourteenth DAS. The type of substrate concentration with the highest germination percentage was the T2 substrate and the shading was 70%. Thus, for such experimental conditions, the concentration of 80% clay with 20% coconut fiber is indicated, when conducted in 70% shading and for 90% shading conditions, the composition of 60% clay and 40% fiber of coconut

The political economy of high skills:Higher Education in knowledge-based labour markets

<p>A successful transition into the knowledge economy depends upon higher level skills, creating unprecedented pressure on university systems to provide labour markets with the skills needed. But what are the political economy dynamics underlying national patterns of high skill formation? The article proposes a framework to theorize the relationship between higher education systems and knowledge-based labour markets based on two dimensions: the type of knowledge economy predominant in a given country and the extent of inter-university competition. It is argued that the former explains what type of higher level skills will be sought by employers and cultivated by governments, while the latter helps us understanding why some higher education systems are more open to satisfying labour market demands compared to others. A set of diverse country case studies (Britain, Germany, South Korea and the Netherlands) is employed to illustrate the theory.</p

Simulation and experimental study of proton bunch self-modulation in plasma with linear density gradients

We present numerical simulations and experimental results of the self-modulation of a long proton bunch in a plasma with linear density gradients along the beam path. Simulation results agree with the experimental results reported [F. Braunmller, T. Nechaeva et al. (AWAKE Collaboration), Phys. Rev. Lett. 125, 264801 (2020)PRLTAO0031-900710.1103/PhysRevLett.125.264801]: with negative gradients, the charge of the modulated bunch is lower than with positive gradients. In addition, the bunch modulation frequency varies with gradient. Simulation results show that dephasing of the wakefields with respect to the relativistic protons along the plasma is the main cause for the loss of charge. The study of the modulation frequency reveals details about the evolution of the self-modulation process along the plasma. In particular for negative gradients, the modulation frequency across time-resolved images of the bunch indicates the position along the plasma where protons leave the wakefields. Simulations and experimental results are in excellent agreement

Experimental study of extended timescale dynamics of a plasma wakefield driven by a self-modulated proton bunch

Plasma wakefield dynamics over timescales up to 800 ps, approximately 100 plasma periods, are studied experimentally at the Advanced Wakefield Experiment (AWAKE). The development of the longitudinal wakefield amplitude driven by a self-modulated proton bunch is measured using the external injection of witness electrons that sample the fields. In simulation, resonant excitation of the wakefield causes plasma electron trajectory crossing, resulting in the development of a potential outside the plasma boundary as electrons are transversely ejected. Trends consistent with the presence of this potential are experimentally measured and their dependence on wakefield amplitude are studied via seed laser timing scans and electron injection delay scan