The response of broiler breeder hens to dietary balanced protein

Two basal feeds (118 and 175 g protein/kg) with similar balanced amino acid mixtures were appropriately blended to produce six experimental diets differing in protein. These were fed for six weeks to 180 broiler breeder hens (Ross 308) housed in individual cages from 26 w of age. A 13 h photoperiod was applied. Half the birds were restricted to 160 g of feed/d, whilst the others were fed ad libitum. The treatments were randomly allocated within six blocks. At the end of the six-week period the mean voluntary intake of the ad libitum-fed birds was 169 g/d whereas the intake of hens on feed restriction was 155 g/d. In spite of the range of protein intakes from 18.5 and 28.8 g/bird, no differences were observed in rate of laying between the two feeding strategies or dietary protein levels, nor were there differences in the proportions of yolk or albumen between these treatments. Egg weight, egg output and weight gain increased with protein intake as did energy retention (kJ/d) whereas heat output (kJ/d) decreased as protein intake increased. Even though dietary protein intake had no effect on rate of lay, the resultant decrease in heat output at high protein intakes suggests that this might be a useful strategy to consider for overcoming mild heat stress.Keywords: Ad libitum feeding, heat production, energy retention, egg compositio

Policy design: who, what, how

What can help students designing? What brings them beyond merely experiencing complexity and building up frustration tolerance? How to pave the road for policy design without dodging its inalienable messy practice? I address these questions by summarizing policy design literature and synthesizing its main ideas. First I describe common ground in this broad literature, to see the forest through the trees. Second I point at differences and controversies in the same literature. These debates urge designers to take a position. In conclusion, I show how these two cross‐sections of the literature help students to see who policy designers are, what makes ‘good’ policy design and how to organize the design process

Top10 inspectors: Board game for a meaningful preparation of standardized tests

ResumenLos exámenes estandarizados son una forma de evaluación formativa que permite a las instituciones obtener información para diferenciar y medir el proceso de aprendizaje de los estudiantes. Sin embargo, los docentes frecuentemente optan por preparar únicamente para el examen a través de una serie de simulacros, estrategias para pruebas estandarizadas y análisis de preguntas. TOP10 Inspectors es una innovación pedagógica en forma de juego de mesa que le permite al docente desarrollar habilidades comunicativas, trabajar procesos de pensamiento y fortalecer la motivación estudiantil hacía su propio aprendizaje. Este artículo explica cómo el juego está compuesto y los resultados obtenidos al preparar a los estudiantes para un examen de suficiencia en inglés.Palabras claves: Motivación, Aprendizaje basado en tareas, habilidades de pensamiento y retroalimentación.AbstractStandardized tests are considered a formative assessment that provide schools with the data needed to differentiate and work effectively on the learning process of the students. However, teachers frequently opt for preparing explicitly for the test by having the students sitting several mock exams, giving tips, and analyzing questions. TOP10 Inspectors is a pedagogical innovation in the form of a board game that enables the teacher to develop communication skills, work Higher Order Thinking Skills (H.O.T.S), and increase the students´ motivation for the their own learning process. This article explains how the game is set up and the results obtained when implementing it for the preparation of an English Proficiency Test.Keywords: Motivation, Task Based Learning, HOTS, and feedback.

Exposure radius of a local coal mine in an Arctic coastal system; correlation between PAHs and mercury as a marker for a local mercury source

Mercury in the Arctic originates from emissions and releases at lower latitudes and, to a lesser extent, from local and regional sources. The relationship between mercury (Hg) and polycyclic aromatic hydrocarbons (PAHs) in sediment can be applied as an indicator of the mercury source. This research examines the Hg contamination gradient from a land-based coal mine to the surrounding coastal environment to quantify the impact of local sources. Total mercury and PAH (Σ(14)PAH) were measured in terrestrial and marine sediments as well as in marine biota. Samples were collected at the mine and two reference sites. Mercury and Σ(14)PAH concentrations in samples collected at the mine site were significantly higher than those at the reference sites. This was also found in the biota samples, although less pronounced. This work addresses the complexities of interpreting data concerning very low contaminant levels in a relatively pristine environment. A clear correlation between PAH and Hg concentration in sediment was found, although a large number of samples had levels below detection limits. PAH profiles, hierarchical clustering, and molecular diagnostic ratios provided further insight into the origin of PAHs and Hg, showing that signatures in sediments from the nearest reference site were more similar to the mine, which was not the case for the other reference site. The observed exposure radius from the mine was small and diluted from land to water to marine biota. Due to low contamination levels and variable PAH profiles, marine biota was less suitable for tracing the exposure radius for this local land-based Hg source. With an expected increase in mobility and availability of contaminants in the warming Arctic, changes in input of PAHs and Hg from land-based sources to the marine system need close monitoring. [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10661-021-09287-5

Mating systems, insect pollination and chemical ecology of grassland Protea species (Proteaceae)

Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.Major transitions between vertebrate and insect pollination systems have occurred many times during the angiosperm radiation and are associated with evolutionary modifications in floral traits. In the large ancestrally bird-pollinated African genus Protea (Proteaceae), an evolutionary shift from bird to insect pollination in the genus is suggested by the fruity diurnal scent of flowers in a recently evolved clade of grassland species. In this study, I confirm that four of these grassland Protea species have mixed mating systems and are indeed insect pollinated, and furthermore demonstrate the functional significance of their floral presentation and scent chemistry for attraction of pollinators, specifically cetoniine beetles. The study species, Protea caffra, Protea dracomontana, Protea simplex and Protea welwitschii, have colourful bowl-shaped inflorescences that produce copious amounts of pollen and dilute, xylose-rich nectar. Cetoniine beetles were found to be the most suitable pollinators due to their abundance, size, relatively pure Protea pollen loads, and their preference for the fruity scent and low growth form of these scented Protea species, as demonstrated by choice experiments in which inflorescences were offered at either end of a y-maze or at various heights above the ground, respectively. Bagging and hand pollinations revealed that these Protea species are self-compatible and capable of autonomous selfing. Self progeny of P. caffra were as vigorous as cross progeny in terms of germinability and survivorship to two months. Vertebrate-excluded and open-pollinated inflorescences yielded similar seed numbers for all species. Supplemental hand-pollinations, however, failed to increase seed set substantially, an indication of resource limitation. Outcrossing rates estimated using polymorphisms at eight allozyme loci in progeny from vertebrate-excluded and open-pollinated treatments of P. caffra were no different (t=0.59), indicating outcrossing by insects and an equal or insubstantial contribution from bird pollinators. The fruity-sweet scents of these species were more complex, with higher whole flower and mass-specific emission rates, than those in eight bird-pollinated congenerics. The overall floral scent is shown to be a blend of emissions from various plant parts, especially nectar. Electroantennography (EAG) revealed that the generalist pollinator Atrichelaphinis tigrina responds to a variety of volatile compounds found in fruity Protea scents. Field trapping confirmed that this cetoniine beetle is strongly attracted to ß-linalool (up to 60% of scent profile) and methyl benzoate. In conclusion, this study demonstrates the evolution of beetle pollination and mixed mating systems in a grassland clade of Protea. Volatile compounds that make up the unique (within Protea) fruity scent of the study species are shown to attract beetles, and the emission of large amounts of these compounds was probably a key step in the transition from bird to insect pollination in Protea

Learning Adaptive Evolutionary Computation for Solving Multi-Objective Optimization Problems

Multi-objective evolutionary algorithms (MOEAs) are widely used to solve multi-objective optimization problems. The algorithms rely on setting appropriate parameters to find good solutions. However, this parameter tuning could be very computationally expensive in solving non-trial (combinatorial) optimization problems. This paper proposes a framework that integrates MOEAs with adaptive parameter control using Deep Reinforcement Learning (DRL). The DRL policy is trained to adaptively set the values that dictate the intensity and probability of mutation for solutions during optimization. We test the proposed approach with a simple benchmark problem and a real-world, complex warehouse design and control problem. The experimental results demonstrate the advantages of our method in terms of solution quality and computation time to reach good solutions. In addition, we show the learned policy is transferable, i.e., the policy trained on a simple benchmark problem can be directly applied to solve the complex warehouse optimization problem, effectively, without the need for retraining