Toward a hierarchical concept of plant stress

A number of attempts have been made to obtain a clear definition of biological stress. However, in spite of the efforts, some controversies on the concept of plant stress remain. The current versions are centered either on the cause (stress factor) or on the effect (stress response) of environmental stress. The objective of this study was to contribute to the definition of stress, using a hierarchical approach. Thus, we have performed an analysis of the most usual stress concepts and tested the relevance of considering different observation scales in a study on plant response to water deficit. Seedlings of Eucalyptus grandis were grown in vitro at water potentials ranging from -0.16 to -0.6 MPa, and evaluated according to growth and biochemical parameters. Data were analyzed through principal component analysis (PCA), which pointed to a hierarchical organization in plant responses to environmental disturbances. Growth parameters (height and dry weight) are more sensitive to water deficit than biochemical ones (sugars, proline, and protein), suggesting that higher hierarchical levels were more sensitive to environmental constraints than lower hierarchical ones. We suggest that before considering an environmental fluctuation as stressful, it is necessary to take into account different levels of plant response, and that the evaluation of the effects of environmental disturbances on an organism depends on the observation scale being used. Hence, a more appropriate stress concept should consider the hierarchical organization of the biological systems, not only for a more adequate theoretical approach, but also for the improvement of practical studies on plants under stress.

A SYSTEMIC CONCEPT OF THE GENE

The univocal correspondence between one gene and one polypeptide has been challenged by many examples of ambiguities. A rapidly expanding list of one-to-many or many-to-one correspondences includes: genomic rearrangements, alternative processing of transcripts, overlapping translation frames, RNA editing, alternative translation modes, and polyprotein cleavage.The genomic message requires interpretation through decoding by a sophisticated information retrieval system which should also carry some kind of information. The full meaning of the whole cell, as a unit, is emphasized.The gene is a combination of (one or more) nucleic acid (DNA or RNA) sequences, defined by the system (the whole cell, interacting with the environment, or the environment alone, in subcellular or pre-cellular systems), that gives origin to a product (RNA or polypeptide).

Insights into the concept of fish welfare

Fish welfare issues are predicated on understanding whether fish are sentient beings. Therefore, we analyzed the logic of the methodologies used for studying this attribute. We conclude that empirical science is unable to prove or to disprove that fish are sentient beings. Thus, we propose a combined ethical-scientific approach for considering fish as sentient beings. The most difficult ongoing question is to determine which conditions fish prefer. Approaches to assess fish preferences should be rigorously and cautiously employed. In light of these considerations, attempts to establish physiological standards for fish welfare are discouraged, and a preference-based definition of fish welfare is proposed.

Establishment of the epithelial attachment and connective tissue adaptation to implants installed under the concept of "platform switching": a histologic study in minipigs

Aim: To validate the platform switching concept at oral implants with respect to the preservation of the alveolar crestal bone levels in an animal model. Material & methods: Five minipigs received three implants each with a 0.25mm implant/ abutment mismatch and were placed flush (T(0)), 1 mm below (T(1)) and 1 mm above (T(+1)) the alveolar bony crest, and as a control, one conventionally restored implant placed at the bone level. The implants were randomly inserted flapless into the mandible. Four months after implant insertion, the animals were sacrificed, and undecalcified block sections were obtained and used for histological analyses. Results: The mean values for peri- implant bone resorption were 1.09 +/- 0.59mm (Control), 0.51 (+/- 0.27 mm, T(0)), 0.50 (+/- 0.46 mm, T(1)) and 1.30 (+/- 0.21 mm, T (+1)), respectively. Statistically significant differences (P< 0.05) were found among the test (T(0), T(-1)) and the control sites. Control implants presented an average biologic width length of 3.20mm (+/- 0.33), with a connective tissue adaptation compartment of 1.29mm (+/- 0.53) and an epithelial attachment of 1.91 mm (+/- 0.71). T(0), T(1) and T(+1) implants presented with a mean biologic width of 1.97mm (+/- 1.20), 2.70 mm (+/- 1.36) and 2.84mm (+/- 0.90), respectively, with a connective tissue adaptation compartment of 1.21mm (+/- 0.97), 1.21 mm (+/- 0.65) and 1.50 mm (+/- 0.70) and an epithelial attachment of 0.84 mm (+/- 0.93), 1.66 mm (+/- 0.88) and 1.35 mm (+/- 0.44), respectively. Differences between the configurations were mainly associated with the length of the epithelial attachment. The epithelial attachment was significantly longer in the C sites than in T(0) (P = 0.014). However, no other differences between configurations were detected. Conclusion: If the implants are positioned at the level of the alveolar bony crest, the platform switching concept may have a minor impact on the length of the epithelial attachment (0.84 vs. 1.91 mm), while the connective tissue adaptation compartment remains relatively unaffected. Moreover, platform switching resulted in less resorption of the alveolar crest (0.58 mm).

Concept of Matching Parallelepiped and its use in the correspondence problem

In this paper, the concept of Matching Parallelepiped (MP) is presented. It is shown that the volume of the MP can be used as an additional measure of `distance' between a pair of candidate points in a matching algorithm by Relaxation Labeling (RL). The volume of the MP is related with the Epipolar Geometry and the use of this measure works as an epipolar constraint in a RL process, decreasing the efforts in the matching algorithm since it is not necessary to explicitly determine the equations of the epipolar lines and to compute the distance of a candidate point to each epipolar line. As at the beginning of the process the Relative Orientation (RO) parameters are unknown, a initial matching based on gradient, intensities and correlation is obtained. Based on this set of labeled points the RO is determined and the epipolar constraint included in the algorithm. The obtained results shown that the proposed approach is suitable to determine feature-point matching with simultaneous estimation of camera orientation parameters even for the cases where the pair of optical axes are not parallel.

Two new species of Zetzellia Oudemans (Acari: Stigmaeidae) that threaten the concept of genera: Disgeneric marriage?

Two new species of Zetzellia Oudemans, Z. agistzellia sp. n. and Z. quasagistemas sp. n., are described from rubber trees of northwestern São Paulo State, Brazil. Females have clear features of Zetzellia, whereas males resemble Agistemus in some characters. Immatures are also described. The discovery of these species raises some problems concerning generic concepts in Stigmaeidae. Since features of different genera are present in the same species, the authors suggest that the scope of those genera should be reviewed. Copyright © 2005 Magnolia Press.

Foucault's heraclitism and the concept of history

Deleuze states that Foucault would have created a new relationship between men and history, a relationship other than that established by the philosophers of history. In order to specify the steps Foucault took to accomplish this invention, I shall support, according to Deleuze, Foucault s Heraclitism as the basis for a genuine Foucaultian concept of history. After outlining the risks taken by Foucault s concept of history, I observe this concept at work through the three periods that perform his thought: Archeology, Genealogy and Aesthetics of Existence. The main characters that embody his concept of history through these periods are: a) the discontinuous profile of history; b) the denaturalization of would-be unhistorical objects; c) the historical dimension of body; d) the eddies of subjectivation in history. We shall focus our inspection on the turn made along Foucault s work when he takes into a new account the theme of subjectivity, mostly in the last two volumes of the History of Sexuality. Thus, our attention turns to the subjectivity defined as a process, in order to investigate individual identity as the result of history.

The role of the state in health public policies: an overview of the debate on the concept of State and the Brazilian case

This article is the result of a narrative literature review. The objective is to show the development of an overview on the ideological debate on the design of state health policies. We argue that the role of the state in the development of health policy, even under the pressure of the global market, may create alternatives to promote and drive economic and social development, meaning they are not subject to economic constraints imposed by the liberal ideal of market. Here is a part of a theoretical discussion about the construction and presence of the State in Latin America, particularly in Brazil. We take the approaches of the Marxist tradition and liberal to the issue as reference. This discussion allows us to understand the historical role of the state in the maintenance of social policies, specifically health, is an alternative to public control eases the intense capital mobility promoted by economic globalization. In this sense, the theme makes the Brazilian health an important issue of social sciences, why is the historicity of the construction of the Brazilian health system, as a public policy that can mirror the actual reconstruction of the institutional framework of the Brazilian state with the establishment instances of negotiation between the various spheres of power that strengthen the state in this process of democratization of Brazilian society.

A efetivação do direito humano à paz por intermédio da Defensoria Pública: atuação em favor da vítima na presecução penal

Pós-graduação em Direito - FCHS

Blaming the victim: Aspects of the Brazilian case

This report describes the consequences and some aspects of the origin and development of victim blaming in accident analysis, and some methods for investigating such events, with particular emphasis on the situation in Brazil. In Brazil, the spread of this practice seems to have been helped by several factors. (1) the idea that occupational accidents are simple phenomena with a limited number of causal factors linked to unsafe actions and/or conditions. In the past, the theory of accident proneness had less influence than in other countries. (2) Government regulations that stipulate the hiring of health and safety officers, production of educational material, and preventive campaigns that emphasize the role of the victim's faulty behavior in the origin of an accident. (3) Mandatory implementation of standardized models for accident investigation directed toward searching for a single cause. Usually one conclusion, expressed in terms of unsafe acts or conditions, is formulated so that whoever performs an unsafe act is responsible for the accident. (4) Lack of knowledge, as shown in Brazilian publications on occupational accidents and in the evolution of studies on the nature of accident phenomena and of strategies adopted for their prevention.