Interpretation of wetlands ecology from ERTS

There are no author-identified significant results in this report

Between subjection and accommodation : the development of José de Anchieta's missionary project in colonial Brazil

This article provides an explanation for why José de Anchieta, S.J., the most influential missionary in early colonial Brazil, engaged in apparently contradictory evangelization practices. Anchieta's belief that both subjection and accommodation were necessary in the process of converting natives is evidenced by his epic poem, De gestis Mendi de Saa, which praised Governor Mem de Sá for the peace he brought to Brazil. The climax of the poem is the death by cannibalism of a bishop. This act, in the minds of Anchieta and fellow Portuguese colonists, constituted a cause for just war. While Anchieta's initial evangelization strategies were focused on taming "savages" by subjecting them to the laws of the colonial governor and altering their indigenous customs, after a relative state of peace was established in the Jesuits' mission villages Anchieta was able to catechize with great attention to indigenous sensibilities. An analysis of his most popular play, On the Feast of St. Lawrence, highlights how European and indigenous customs combined on the stages of colonial Brazil. Through Anchieta's poetry and drama, we see that there were many ways of proceeding among the Jesuits, and that their apparent contradictions are better understood in view of their ultimate purpose: converting souls

Transforming Indigenous Vice to Virtue on the Stages of Colonial Brazil: an analysis of Jesuit Theater and the plays of José de Anchieta

José de Anchieta (1534-1597), one of the most influential missionaries in the history of Catholic expansion into South America, addressed the theological and cultural issues of explaining Christian life to the Tupi. Through his dramatic works, Anchieta sought to reform the Tupi warrior and reorient Tupi vice to virtue. Seeking to win the moral fidelity of the Tupi, on stage he compromised on various aspects of Catholicism in order to transform the Tupi warrior into a warrior of Christ. Scholars debate whether Jesuit theater in the sixteenth and seventeenth centuries was used for catechetical purposes or if its primary objective was to promote Christian culture, life and morality. Yet, the Jesuit project did not consist of separating doctrine and way of life. As the works and compromises of Anchieta show, preaching doctrine, teaching Christian culture and maintaining an alliance with the crown were all possible.Entre os missionários mais influentes na história da expansão na América do Sul encontra-se o espanhol José de Anchieta (1534-1597), que abordou as questões teológicas e culturais de como explicar a vida cristã aos Tupi. As suas peças do teatro eram escritas para reformar o guerreiro tupi e redireccionar a vida tupi dos vícios para as virtudes. Os palcos de Anchieta eram um campo de batalha para ganhar a fidelidade moral do tupi, onde Anchieta condescendeu em muitos aspectos do Catolicismo com o objectivo último de transformar o guerreiro tupi num guerreiro de Cristo. Académicos debatem se o teatro jesuítico nos séculos XVI e XVII era usado principalmente para a catequese ou se era usado para promover a cultura, vida e moralidade cristã. No entanto, o projecto jesuítico não visava separar a doutrina e a maneira de viver. Como as peças e os compromissos de Anchieta mostram, pregar a doutrina, ensinar a cultura cristã e manter a aliança com a coroa era possível em simultâneo

Electrical effects on droplet behaviour

The effect of charge on water droplets modulates various aspects of their behaviour. These include the droplet stability, evaporation, and lifetime. Microphysical models have been developed such that a reasonably good understanding of these processes has been achieved. However, the specific effects of charge deserve further scrutiny as they are an intrinsic component of the factors controlling droplet characteristics. Describing the effects of these requires an understanding of the electrostatic pressure present in the droplet and its surface tension. One way to test these effects and assess droplet response to charge is to take an experimental approach to make observations directly. In this study, individual droplets are levitated in an acoustic wave to allow isolated measurements to be taken. The droplets are monitored using a CCD camera with a microscope objective lens. In some cases, with sufficient charge present, effects on droplet stability can be observed as Rayleigh explosions, where a sudden drop in mass is seen superimposed on the evaporation profile. These events also allow the charge on the droplet to be calculated, which is then compared with the droplet evaporation. Another factor that plays a part in droplet behaviour is droplet composition. Different substances have different surface tension, and this is explored by performing some experiments on sulphuric acid droplets. Theory predicts that the more highly charged a droplet is, the more resistant to evaporation it becomes. Experimental data collected during this study agrees with this, with more highly charged droplets observed to have slower evaporation rates. However, highly charged drops were also observed to periodically become unstable during evaporation and undergo Rayleigh explosions. Each instability of a highly charged drop removes mass, reducing the overall droplet lifetime regardless of the slower evaporation rate. The sulphuric acid droplets were observed to be much more resistant to evaporation and no Rayleigh instabilities were observed

Protein inactivation in mycobacteria by controlled proteolysis and its application to deplete the beta subunit of RNA polymerase

Using a component of the Escherichia coli protein degradation machinery, we have established a system to regulate protein stability in mycobacteria. A protein tag derived from the E. coli SsrA degradation signal did not affect several reporter proteins in wild-type Mycobacterium smegmatis or Mycobacterium tuberculosis. Expression of the adaptor protein SspB, which recognizes this modified tag and helps deliver tagged proteins to the protease ClpXP, strongly decreased the activities and protein levels of different reporters. This inactivation did not occur when the function of ClpX was inhibited. Using this system, we constructed a conditional M. smegmatis knockdown mutant in which addition of anhydrotetracycline (atc) caused depletion of the beta subunit of RNA polymerase, RpoB. The impact of atc on this mutant was dose-dependent. Very low amounts of atc did not prevent growth but increased sensitivity to an antibiotic that inactivates RpoB. Intermediate amounts of RpoB knockdown resulted in bacteriostasis and a more substantial depletion led to a decrease in viability by up to 99%. These studies identify SspB-mediated proteolysis as an efficient approach to conditionally inactivate essential proteins in mycobacteria. They further demonstrate that depletion of RpoB by ∼93% is sufficient to cause death of M. smegmatis

Photometric and spectroscopic analysis of the Type II SN 2020jfo with a short plateau

We present high-cadence photometric and spectroscopic observations of SN~2020jfo in ultraviolet and optical/near-infrared bands starting from $\sim 3$ to $\sim 434$ days after the explosion, including the earliest data with the 10.4\,m GTC. SN~2020jfo is a hydrogen-rich Type II SN with a relatively short plateau duration ($67.0 \pm 0.6$ days). When compared to other Type II supernovae (SNe) of similar or shorter plateau lengths, SN~2020jfo exhibits a fainter peak absolute $V$-band magnitude ($M_V = -16.90 \pm 0.34$ mag). SN~2020jfo shows significant H$\alpha$ absorption in the plateau phase similar to that of typical SNe~II. The emission line of stable [Ni~II] $\lambda$7378, mostly seen in low-luminosity SNe~II, is very prominent in the nebular-phase spectra of SN~2020jfo. Using the relative strengths of [Ni~II] $\lambda$7378 and [Fe~II] $\lambda$7155, we derive the Ni/Fe production (abundance) ratio of 0.08--0.10, which is $\sim 1.5$ times the solar value. The progenitor mass of SN~2020jfo from nebular-phase spectral modelling and semi-analytical modelling falls in the range of 12--15\,$M_\odot$. Furthermore, semi-analytical modelling suggests a massive H envelope in the progenitor of SN~2020jfo, which is unlikely for SNe~II having short plateaus.Comment: 20 pages (plus 5 pages appendix), 19 figures, Accepted for publication in MNRA

Prediction of Cellular Burden with Host--Circuit Models

Heterologous gene expression draws resources from host cells. These resources include vital components to sustain growth and replication, and the resulting cellular burden is a widely recognised bottleneck in the design of robust circuits. In this tutorial we discuss the use of computational models that integrate gene circuits and the physiology of host cells. Through various use cases, we illustrate the power of host-circuit models to predict the impact of design parameters on both burden and circuit functionality. Our approach relies on a new generation of computational models for microbial growth that can flexibly accommodate resource bottlenecks encountered in gene circuit design. Adoption of this modelling paradigm can facilitate fast and robust design cycles in synthetic biology

The Evolution of Enzyme Specificity in the Metabolic Replicator Model of Prebiotic Evolution

The chemical machinery of life must have been catalytic from the outset. Models of the chemical origins have attempted to explain the ecological mechanisms maintaining a minimum necessary diversity of prebiotic replicator enzymes, but little attention has been paid so far to the evolutionary initiation of that diversity. We propose a possible first step in this direction: based on our previous model of a surface-bound metabolic replicator system we try to explain how the adaptive specialization of enzymatic replicator populations might have led to more diverse and more efficient communities of cooperating replicators with two different enzyme activities. The key assumptions of the model are that mutations in the replicator population can lead towards a) both of the two different enzyme specificities in separate replicators: efficient “specialists” or b) a “generalist” replicator type with both enzyme specificities working at less efficiency, or c) a fast-replicating, non-enzymatic “parasite”. We show that under realistic trade-off constraints on the phenotypic effects of these mutations the evolved replicator community will be usually composed of both types of specialists and of a limited abundance of parasites, provided that the replicators can slowly migrate on the mineral surface. It is only at very weak trade-offs that generalists take over in a phase-transition-like manner. The parasites do not seriously harm the system but can freely mutate, therefore they can be considered as pre-adaptations to later, useful functions that the metabolic system can adopt to increase its own fitness