Self-organized patterns of coexistence out of a predator-prey cellular automaton

We present a stochastic approach to modeling the dynamics of coexistence of prey and predator populations. It is assumed that the space of coexistence is explicitly subdivided in a grid of cells. Each cell can be occupied by only one individual of each species or can be empty. The system evolves in time according to a probabilistic cellular automaton composed by a set of local rules which describe interactions between species individuals and mimic the process of birth, death and predation. By performing computational simulations, we found that, depending on the values of the parameters of the model, the following states can be reached: a prey absorbing state and active states of two types. In one of them both species coexist in a stationary regime with population densities constant in time. The other kind of active state is characterized by local coupled time oscillations of prey and predator populations. We focus on the self-organized structures arising from spatio-temporal dynamics of the coexistence. We identify distinct spatial patterns of prey and predators and verify that they are intimally connected to the time coexistence behavior of the species. The occurrence of a prey percolating cluster on the spatial patterns of the active states is also examined.Comment: 19 pages, 11 figure

Taurine: A Potential Ergogenic Aid for Preventing Muscle Damage and Protein Catabolism and Decreasing Oxidative Stress Produced by Endurance Exercise

The aim of this study was to evaluate the effects of taurine and chocolate milk supplementation on oxidative stress and protein metabolism markers, and aerobic parameters in triathletes. Methods: A double-blind, crossover study was conducted with 10 male triathletes, aged 30.9 ± 1.3 year, height 1.79 ± 0.01 m and body weight 77.45 ± 2.4 kg. Three grams of taurine and 400 ml of chocolate milk (TAUchoc), or a placebo (chocolate milk) (CHOC) was ingested post exercise for 8 weeks. Oxidative stress marker levels, and 24 h urinary nitrogen, creatinine, and urea excretion were measured before and after 8 weeks of training and supplementation with TAUchoc or CHOC. A maximal incremental running test on a treadmill was performed in order to evaluate aerobic parameters: Vmax, heart rate (HR) and rate of perceived exertion (RPE). Results: TAUchoc treatment during the 8 weeks resulted in increased taurine plasma levels (PRE 201.32 ± 29.03 μmol/L and POST 234.36 ± 35.51 μmol/L, p = 0.01), decreased malondialdehyde levels (19.4%, p = 0.03) and urinary nitrogen excretion (−33%, p = 0.03), and promoted positive nitrogen balance (p = 0.01). There were no changes in reduced glutathione (TAUchoc PRE 0.72 ± 0.08 mmol/L and POST 0.83 ± 0.08 mmol/L; CHOC PRE 0.69 ± 0.08 mmol/L and POST 0.81 ± 0.06 mmol/L), vitamin E plasma levels (TAUchoc PRE 33.99 ± 2.52 μmol/L and 35.95 ± 2.80 μmol/L and CHOC PRE 31.48 ± 2.12 μmol/L and POST 33.77 ± 3.64 μmol/L), or aerobic parameters, which were obtained in the last phase of the maximal incremental running test (Vmax TAUchoc PRE 13 ± 1.4 km/h and POST 13.22 ± 1.34 km/h; CHOC PRE 13.11 ± 2.34 km/h and POST 13.11 ± 2.72 km/h), the heart rate values were TAUchoc PRE 181.89 ± 24.18 bpm and POST 168.89 ± 46.56 bpm; CHOC PRE 181.56 ± 2.14 bpm and POST 179.78 ± 3.4 bpm, and the RPE were TAUchoc PRE 8.33 ± 2.4 AU and POST 9.1 ± 2.1 AU; CHOC PRE 8.11 ± 4.94 AU and POST 8.78 ± 2.78 AU). Conclusion: Taurine supplementation did not improve aerobic parameters, but was effective in increasing taurine plasma levels and decreasing oxidative stress markers, which suggests that taurine may prevent oxidative stress in triathletes

Flipping the Classroom: Reflections on the flipped classroom and teaching practice in Philosophy in the Higher Education

The new Coronavirus Pandemic has revealed the need for a methodological redefinition of teaching and learning attitude of teachers and students, through the pedagogical use of digital technologies. Therefore, this article aims to present reflections on the use of the Flipped Classroom methodology as a re-signifying possibility for the teaching of Philosophy in Higher Education, considering the context of remote emergency teaching. Assuming that there is a concern with the didactic-pedagogical and sociopolitical process of teaching and learning that constitutes teaching practice in the teaching of Philosophy in Brazilian Academies, the question is: what are the advantages and challenges of using the flipped classroom methodology in the process of teaching and learning Philosophy in Higher Education? For this, two fundamental aspects of the formal educational process are discussed: the first refers to the didactic-pedagogical and sociopolitical aspects of the teaching and learning process that constitute the teaching practice, as the content and didactics are emphasized. that is, the “what” and the “how to teach” and the second, it is about the need for re-signification/updating of traditional teaching in face of active methodologies. Based on the current context of remote teaching and/or hybrid teaching in Higher Education in Brazil, it is concluded that is necessary to reframe pedagogical practice in terms of the production of academic knowledge, without losing sight of the conditions in which it is produced

BIOTRANSFORMAÇÃO IN VITRO DE UM COMPOSTO ANTITUMORAL (LQFM 018)

Introdução e objetivos: O composto LQFM 018 foi sintetizado no Laboratório de QuímicaFarmacêutica Medicinal/FF/UFG, é um potente agente antitumoral que em ensaiostoxicológicos agudos in vitro, no modelo de vermelho neutro, não apresentou efeito tóxicosignificativo para as células basais. Estudos do metabolismo são de grande importânciapara o desenvolvimento de novos fármacos. O principal objetivo deste trabalho foi aaplicação de metodologia utilizando fungos filamentosos para mimetizar o metabolismohumano do LQFM 018 e possibilitar a preparação in vitro de metabólitos. Metodologia:LQFM 018 solubilizado em etanol/DMSO foi adicionado ao meio reacional PDSM, napresença de fungos filamentosos e foi incubados por 96 h a 27ºC sob agitação de 200rpm. Acinética reacional foi realizada por Cromatografia em Camada Delgada (CCD). Osderivados obtidos foram extraídos com acetato de etila e purificados por Cromatografia emColuna (CC) com Sílica-gel, para em seguida serem caracterizados por RessonânciaMagnética Nuclear (RMN). Resultados e discussões: Foram identificados vários fungoscapazes de catalisar a reação dando origem a cinco prováveis metabólitos Mortierellaisabelina foi a cepa mais promissora. Quantidade suficiente dos metabólitos para ensaios deatividade antitumoral foram obtidos e serão realizados posteriormente. Conclusões: Osfungos filamentosos foram capazes de biotransformar o LQFM 018, produzindo prováveismetabólitos

Response to comment on 'Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity'

Lambert et al. question our retrospective and holistic epidemiological assessment of the role of chytridiomycosis in amphibian declines. Their alternative assessment is narrow and provides an incomplete evaluation of evidence. Adopting this approach limits understanding of infectious disease impacts and hampers conservation efforts. We reaffirm that our study provides unambiguous evidence that chytridiomycosis has affected at least 501 amphibian species

A genetic algorithm for the one-dimensional cutting stock problem with setups

This paper investigates the one-dimensional cutting stock problem considering two conflicting objective functions: minimization of both the number of objects and the number of different cutting patterns used. A new heuristic method based on the concepts of genetic algorithms is proposed to solve the problem. This heuristic is empirically analyzed by solving randomly generated instances and also practical instances from a chemical-fiber company. The computational results show that the method is efficient and obtains positive results when compared to other methods from the literature. © 2014 Brazilian Operations Research Society

A cross-national study on the antecedents of work–life balance from the fit and balance perspective

Drawing on the perceived work–family fit and balance perspective, this study investigates demands and resources as antecedents of work–life balance (WLB) across four countries (New Zealand, France, Italy and Spain), so as to provide empirical cross-national evidence. Using structural equation modelling analysis on a sample of 870 full time employees, we found that work demands, hours worked and family demands were negatively related to WLB, while job autonomy and supervisor support were positively related to WLB. We also found evidence that resources (job autonomy and supervisor support) moderated the relationships between demands and work–life balance, with high resources consistently buffering any detrimental influence of demands on WLB. Furthermore, our study identified additional predictors of WLB that were unique to some national contexts. For example, in France and Italy, overtime hours worked were negatively associated with WLB, while parental status was positively associated with WLB. Overall, the implications for theory and practice are discussed.Peer ReviewedPostprint (author's final draft