Evolutionary History of Arabidopsis thaliana Aminoacyl-tRNA Synthetase Dual-Targeted Proteins

Aminoacyl-transfer RNA (tRNA) synthetases (aaRS) are key players in translation and act early in protein synthesis by mediating the attachment of amino acids to their cognate tRNA molecules. In plants, protein synthesis may occur in three subcellular compartments (cytosol, mitochondria, and chloroplasts), which requires multiple versions of the protein to be correctly delivered to its proper destination. The organellar aaRS are nuclear encoded and equipped with targeting information at the N-terminal sequence, which enables them to be specifically translocated to their final location. Most of the aaRS families present organellar proteins that are dual targeted to mitochondria and chloroplasts. Here, we examine the dual targeting behavior of aaRS from an evolutionary perspective. Our results show that Arabidopsis thaliana aaRS sequences are a result of a horizontal gene transfer event from bacteria. However, there is no evident bias indicating one single ancestor (Cyanobacteria or Proteobacteria). The dual-targeted aaRS phylogenetic relationship was characterized into two different categories (paralogs and homologs) depending on the state recovered for both dual-targeted and cytosolic proteins. Taken together, our results suggest that the dual-targeted condition is a gain-of-function derived from gene duplication. Selection may have maintained the original function in at least one of the copies as the additional copies diverged.

A history of agricultural production at Neolithic Catalhoyuk East, Turkey

A history of agricultural production is proposed for Neolithic Catalhoyuk East, central Turkey, using archaeobotanical, environmental, population and settlement studies. In the aceramic early phase of site occupation, intensive strategies developed as changes in population and environment caused stress on food supplies produced within a limited territory. Food exchange may have been part of the social means by which Catalhoyuk and nearby contemporary settlements amalgamated into the single site of the main occupation phase. Population change, inherited territories and continuing environmental impact led to the development of an extensive system of agriculture using widely dispersed dry soils, with an intensive regime applied to nearby alluvial soils. Social tensions caused by the evolution of this system contributed to the fissioning of the site by the Chalcolithic.

Sucrose Fermentation by Brazilian Ethanol Production Yeasts in Media Containing Structurally Complex Nitrogen Sources

Four Saccharomyces cerevisiae Brazilian industrial ethanol production strains were grown, under shaken and static conditions, in media containing 22% (w/v) sucrose supplemented with nitrogen sources varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids) and peptides (peptone). Sucrose fermentations by Brazilian industrial ethanol production yeasts strains were strongly affected by both the structural complexity of the nitrogen source and the availability of oxygen. Data suggest that yeast strains vary in their response to the nitrogen source`s complex structure and to oxygen availability. In addition, the amount of trehalose produced could be correlated with the fermentation performance of the different yeasts, suggesting that efficient fuel ethanol production depends on finding conditions which are appropriate for a particular strain, considering demand and dependence on available nitrogen sources in the fermentation medium.

Glucose and Fructose Fermentation by Wine Yeasts in Media Containing Structurally Complex Nitrogen Sources

Glucose and fructose fermentations by industrial yeasts strains are strongly affected by both the structural complexity of the nitrogen Source and the availability of oxygen. In this Study two Saccharomyces cerevisiae industrial wine strains were grown, under shaken and static conditions, in a media containing either a) 20% (w/v) glucose, or b) 10% (w/v) fructose and 10% (w/v) glucose or c) 20% (w/v) fructose, all supplemented with nitrogen Sources varying from a single ammonium salt (ammonium Sulfate) to free amino acids (casamino acids) and peptides (peptone). Data Suggest that 1 complex Structured nitrogen source is not submitted to the same control mechanisms as those involved in the utilization of simpler structured nitrogen Sources, and mutual interaction between carbon and nitrogen Sources, including the mechanisms involved ill the regulation of aerobic/anaerobic metabolism, may play in important role in defining yeast fermentation performance and the differing response to the structural complexity of the nitrogen Source, with a strong impact oil fermentation performance.

NEWS CONCERNING A CERTAIN TAMOIO CONFEDERATION

In this article we revisit a famous chapter of Brazilian history, yet to be properly analysed from an ethnological perspective: the `Tamoio confederation,` a coalition of 16th century coastal Tupian groups who threatened to undermine Portuguese colonization during the dispute between the French and Portuguese for the Guanabara region (now Rio de Janeiro). Was this `confederation` a new phenomenon in Tupian politics, engendered by the Conquest and inducing a shift towards political centralization? Or was it, on the contrary, the actualization of a possibility already (always) present in Tupian forms of political organization and action? These are the questions guiding our inquiry, which we seek to answer through the use of both historical sources and the in-depth ethnological knowledge of Tupi-Guarani peoples developed by various authors over recent decades.

History teaching today: wanderings, gains and losses

This article analyzes traditions of debate about the teaching of history in Brazil since the 1964-1984 dictatorship. It discusses the changes, continuities, achievements and losses in the history of the discipline. It emphasizes the importance of school culture, the necessary continuity of the school as an institution and dialogue with non-school forms of education.

ACHIEVEMENTS AND CHALLENGES OF ISPRM

This paper describes the history of the International Society of Physical and Rehabilitation Medicine (ISPRM) Past achievements. and current challenges are outlined ISPRM has been successful In setting up a central office. attracting individual and national members,. holding International congresses, and establishing relations with the Journal of Rehabilitation Medicine (JRM) as the organization`s official journal ISPRM is currently; In official relations with the World Health Organization (WHO) and collaborates closely, with WHO`s Disability and Rehabilitation team ISPRM, however also faces challenges with regard to its growth and the realization of its goals These Include boundaries of voluntary leadership. limited economic resources, the need for enhancing the central office. variations in membership. limits of the current congress bidding system and structure, relations with regional societies, and the need to further develop policies within the field of Physical and Rehabilitation Medicine (PRM) and In relation to WHO and the United Nations system is concluded that ISPRM must evolve from an organization, of which the main activities ay-e to hold a biennial congress hosted by a member nation and to provide input to WHO on request. Into a professional non-governmental organization (NGO) ISPRA should embark on assuming, a leadership role at the further development of PRM within the broader area of human functioning and rehabilitation

The response of native Australian rodents to predator odours varies seasonally: a by-product of life history variation?

Small mammals are subject to predation from mammalian, avian and reptilian predators. There is an obvious advantage for prey species to detect the presence of predators in their environment, enabling them to make decisions about movement and foraging behaviour based on perceived risk of predation. We examined the effect of faecal odours from marsupial and eutherian predators, and a native reptilian predator, on the behaviour of three endemic Australian rodent species (the fawn-footed melomys, Melomys cervinipes, the bush rat, Rattus fuscipes, and the giant white-tailed rat, Uromys caudimaculatus) in rainforest remnants on the Atherton Tableland, North Queensland, Australia. Infrared camera traps were used to assess visit rates of rodents to odour stations containing faecal and control odours. Rodents avoided odour stations containing predator faeces, but did not avoid herbivore or control odours. The responses of the three prey species differed: in the late wet season U. caudimaculatus avoided predator odours, whereas R. fuscipes and M. cervinipes did not. In contrast, in the late dry season all three species avoided odour stations containing predator odours. We speculate that these different responses may result from variation in life history traits between the species. (c) 2006 The Association for the Study of Animal Behaviour Published by Elsevier Ltd. All rights reserved.