Investigation of the corrosion behaviour of AA 2024-T3 in low concentrated chloride media

Aluminium alloy (AA) 2024-T3 is an important engineering material due to its widespread use in the aerospace industry. However, it is very prone to localized corrosion attack in chloride containing media, which has been mainly associated to the presence of coarse intermetallics (IMs) in its microstructure. In this work the corrosion behaviour of AA 2024-T3 in low concentrated chloride media was investigated using microscopy and electrochemical methods. TEM/EDS observations on non-corroded samples evidenced the heterogeneous composition within the IMs. In addition, SEM observations showed that intermetallics with the same nominal composition present different reactivity, and that both types of coarse IMs normally found in the alloy microstructure are prone to corrosion. Moreover, EDS analyses showed important compositional changes in corroded IMs, evidencing a selective dissolution of their more active constituents, and the onset of an intense oxygen peak, irrespective to the IM nature, indicating the formation of corrosion products. On the other hand, the results of the electrochemical investigations, in accordance with the SEM/EDS observations, evidenced that IMs corrosion dominates the electrochemical response of the alloy during the first hours of immersion in the test electrolyte. (c) 2008 Elsevier Ltd. All rights reserved.

Social behaviour of collared peccaries (Pecari tajacu) under three space allowances

Captive breeding of peccaries is on the increase in neotropical countries. Few studies, however, have reported behavioural responses of wild animals under farmed conditions. Therefore, the aim of this study was to evaluate the effects of space allowance on the occurrence of social behaviour patterns on farmed collared peccary (Pecan tajacu). We observed three herds of collared peccaries each containing eight acquainted individuals. Using a 3 x 3 Latin square design, herds were allocated, in a random order, to one of the three experimental enclosures, each with a different size. 375, 750 and 1,500 m(2) of total available area, each with three wooden shelters. We recorded all the occurrences of selected positive and agonistic behavioural patterns that occurred 90 min before and during feeding Enclosure size had a significant effect on agonistic patterns of peccaries during feeding, in that more agonistic behaviour was observed in smaller spaces We also found that shelter usage increased as space decreased Differing space allowances, however, did not have an effect on the occurrence of positive interactions that were more frequent before compared to during feeding. We concluded that enclosure size had an effect on the expression of agonistic be and the use of shelters by collared peccaries Thus, animal welfare can be improved by adopting at least 187 5 m(2) per peccary. In addition, our study also confirmed the importance of shelter areas in collared peccary husbandry.

Evaluation of the role of environmental factors in the human gastrointestinal tract on the behaviour of probiotic cultures of Lactobacillus casei Shirota and Lactobacillus casei LC01 by the use of a semi-dynamic in vitro model

This study evaluated the influence of gastrointestinal environmental factors (pH, digestive enzymes, food components, medicaments) on the survival of Lactobacillus casei Shirota and Lactobacillus casei LC01, using a semi-dynamic in vitro model that simulates the transit of microorganisms through the human GIT. The strains were first exposed to different simulated gastric juices for different periods of time (0, 30, 60 and 120 min), and then to simulated intestinal fluids for zero, 120, 180 and 240 min, in a step-wise format. The number of viable cells was determined after each step. The influence of food residues (skim milk) in the fluids and resistance to medicaments commonly used for varied therapeutic purposes (analgesics, antiarrhythmics, antibiotics, antihistaminics, proton pump inhibitors, etc.) were also evaluated. Results indicated that survival of both cultures was pH and time dependent, and digestive enzymes had little influence. Milk components presented a protective effect, and medicaments, especially anti-inflammatory drugs, influenced markedly the viability of the probiotic cultures, indicating that the beneficial effects of the two probiotic cultures to health are dependent of environmental factors encountered in the human gastrointestinal tract.

Investigating the gap between citizens` sustainability attitudes and food purchasing behaviour: empirical evidence from Brazilian pork consumers

Consumers worldwide are increasingly concerned with sustainable production and consumption. Recently, a comprehensive study ranked 17 countries in regard to their environmentally friendly behaviour among consumers. Brazil was one of the top countries in the list. Yet, several studies highlight significant differences between consumers` intentions to consume ethically, and their actual purchase behaviour: the so-called `Attitude-Behaviour Gap`. In developing countries, few studies have been conducted on this issue. The objective of this study is therefore to investigate the gap between citizens` sustainability-related attitudes and food purchasing behaviour using empirical data from Brazil. To this end, Brazilian citizens` attitudes towards pig production systems were mapped through conjoint analysis and their coexistence with relevant pork product-related purchasing behaviour of consumers was investigated through cluster analysis. The conjoint experiment was carried Out with empirical data collected from 475 respondents surveyed in the South and Center-West regions of Brazil. The results of the conjoint analysis were used for a subsequent cluster analysis in order to identify clusters of Brazilian citizens with diversified attitudes towards pig production systems, using socio-demographics, attitudes towards sustainability-related themes that are expected to influence the way they evaluate pig production systems, and consumption frequency of various pork products as clusters` background information. Three clusters were identified as `indifferent`, `environmental conscious` and `sustainability-oriented` citizens. Although attitudes towards environment and nature had indeed an influence on citizens` specific attitudes towards pig farming at the cluster level, the relationship between `citizenship` and consumption behaviour was found to be weak. This finding is similar to previous research conducted with European consumers: what people (in their role of citizens) think about pig production systems does not appear to significantly influence their pork consumption choices. Improvements in the integrated management of this chain would better meet consumers` sustainability-related expectations towards pig production systems.

Fight versus flight: the interaction of temperature and body size determines antipredator behaviour in tegu lizards

Ectotherm antipredator behaviour might be strongly affected both by body temperature and size: when environmental temperatures do not favour maximal locomotor performance, large individuals may confront predators, whereas small animals may flee, simply because they have no other option. However, integration of body size and temperature effects is rarely approached in the study of antipredator behaviour in vertebrate ectotherms. In the present study we investigated whether temperature affects antipredator responses of tegu lizards, Tupinambis merianae, with distinct body sizes, testing the hypothesis that small tegus (juveniles) run away from predators regardless of the environmental temperature, because defensive aggression may not be an effective predator deterrent, whereas adults, which are larger, use aggressive defence at low temperatures, when running performance might be suboptimal. We recorded responses of juvenile (small) and adult (large) tegu lizards to a simulated predatory attack at five environmental temperatures in the laboratory. Most differences between the two size classes were observed at low temperatures: large tegus were more aggressive overall than were small tegus at all temperatures tested, but at lower temperatures, the small lizards often used escape responses whereas the large ones either adopted a defensive posture or remained inactive. These results provide strong evidence that body size and temperature affect the antipredator responses of vertebrate ectotherms. We discuss the complex and intricate network of evolutionary and ecological parameters that are likely to be involved in the evolution of such interactions. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Asymptotic behaviour of two-dimensional time-delayed Navier-Stokes equations

We consider the two-dimensional Navier-Stokes equations with a time-delayed convective term and a forcing term which contains some hereditary features. Some results on existence and uniqueness of solutions are established. We discuss the asymptotic behaviour of solutions and we also show the exponential stability of stationary solutions.

Political Parties and Governors as Determinants of Legislative Behavior in Brazil`s Chamber of Deputies, 1988-2006

This article examines the relative importance of regional and national forces in shaping the behavior of Brazilian legislators at the national level. A widely held view is that national legislators respond to state pressures in making decisions, rather than pressures from the national government. Governors not only can influence national debates but also can determine outcomes by exerting control over their states` legislative delegations. This article examines a dataset of all roll-call votes in the Chamber of Deputies between 1989 and 2006 to isolate and evaluate the impact of local pressures on legislative voting. Spanning the terms of five presidents and five different congresses, the data show that the local influence is weaker than the national on the voting decisions of individual legislators and the voting cohesion of state delegations. Alternative institutional resources allow the central government to counteract the centrifugal pressures of federalism and other institutional influences.

Sweeping democracy: considerations on the political relations between Janio Quadros and the National Congress

This article examines the relation between President Janio Quadros and the National Congress during the early 1960`s. Based on the analysis of the discourse of these figures, it proposes that Quadros maneuvered to diminish the legitimacy of the Congress in the public opinion, thus disrespecting its constitutional competencies. Consequently, it shows that not only did the Congress structure political mechanisms in an attempt to recover its credibility with society, but also that this dispute and its results had important effects on President Joao Goulart`s administration and even on the 1964 military coup.

RACE, RESOURCES, AND POLITICAL PARTICIPATION IN A BRAZILIAN CITY

Does race influence political behavior in Brazil? Using data from Belo Horizonte, Brazil, we explore whether an individual`s propensity to take part in a political association is affected by race, independent of socioeconomic position and of the availability of resources derived from this position. We found that white individuals participate more in political associations than do black individuals; however, after taking into account the differences in all types of resources, we found no difference in participation by racial groups. Nevertheless, by interacting race, skills, and income, it turns out that different racial groups use the same resources differently. A white individual`s propensity to participate politically is significantly more affected by income than a similar black individual`s propensity. Therefore, we argue that race mediates the effect of resources on political participation, which means that either different groups may use different resources or different groups can differ in how intensively they use resources.

Letters that construct limits: intellectual and political projects in the letters of Capistrano de Abreu to Barao do Rio Branco (1886-1903)

The intention of this paper is to analyze the letters from Capistrano de Abreu to Barao do Rio Branco in the years between 1886 and 1903. The focus will be given to the divergences around the notion of territorial formation, a basic concept for these authors who were thinking about the construction of a historical narrative at the end of the 19(th) and beginning of the 20(th) century. Later, the question is the construction of the craft of the historian in the letters of Capistrano de Abreu and his distinction and proximity to the ideas of the Barao do Rio Branco.

A description of adaptive and maladaptive behaviour in children and adolescents with Cri-du-chat syndrome

Background Psychological tests can be useful to record adaptive and maladaptive behaviours of children with intellectual disability. The objective of this study was to describe the adaptive and maladaptive behaviour of children and adolescents with Cri-du-chat syndrome. Methods The sample consisted of 10 children and adolescents with Cri-du-chat syndrome (mean chronological age = 11.3 years, mean mental age = 18 months). The developmental quotient was calculated through the Psychoeducational Profile - Revised. An observational protocol was used to record adaptive and maladaptive behaviours. Results The number of maladaptive behaviours observed was different among participants. However, all of them had high rates of adaptive behaviours, such as rule-following. Conclusions These results, though preliminary, justify that we continue to think about the need for psychoeducational interventions aimed at stimulating the repertoire of adaptive behaviours, in people with Cri-du-chat syndrome.

Childhood adversities as risk factors for onset and persistence of suicidal behaviour

Background Suicide is a leading cause of death worldwide, but the precise effect of childhood adversities as risk factors for the onset and persistence of suicidal behaviour (suicide ideation, plans and attempts) are not well understood. Aims To examine the associations between childhood adversities as risk factors for the onset and persistence of suicidal behaviour across 21 countries worldwide. Method Respondents from nationally representative samples (n = 55 299) were interviewed regarding childhood adversities that occurred before the age of 18 years and lifetime suicidal behaviour. Results Childhood adversities were associated with an increased risk of suicide attempt and ideation in both bivariate and multivariate models (odds ratio range 1.2-5.7). The risk increased with the number of adversities experienced, but at a decreasing rate. Sexual and physical abuse were consistently the strongest risk factors for both the onset and persistence of suicidal behaviour, especially during adolescence. Associations remained similar after additional adjustment for respondents` lifetime mental disorder status. Conclusions Childhood adversities (especially intrusive or aggressive adversities) are powerful predictors of the onset and persistence of suicidal behaviours.

Post-craniotomy headache: characteristics, behaviour and effect on quality of life in patients operated for treatment of supratentorial intracranial aneurysms

We prospectively studied headache characteristics during 6 months after craniotomy performed for treatment of cerebral aneurysms in 79 patients. Semistructured interviews, headache diaries, the Hospital Anxiety and Depression Scale and the Epworth Sleepiness Scales, the Short Form-36 Health Survey (SF-36) and McGill Pain Questionnaire were used. Seventy-two patients had headaches, half before the fifth day after surgery. Changes were observed in headache diagnosis, side and site in the postoperative period. Headache frequency increased immediately after surgery and then decreased over time. Headache frequency was associated with depressive and anxiety symptoms. Pain intensity was higher in women and in patients with more anxiety symptoms. An incidence of post-craniotomy headache of 40% was observed according to International Headache Society classification criteria, 10.7% of the acute and 29.3% of the chronic type. The bodily pain domain of the SF-36 was worse in patients with more anxiety symptoms. Greater frequencies of headache were associated with lower scores on bodily pain and social functioning.

Modulation of anxiety-like behaviour by Transient Receptor Potential Vanilloid Type 1 (TRPV1) channels located in the dorsolateral periaqueductal gray

The endocannabinoid anandamide is a possible agonist at the Transient Receptor Potential Vanilloid Type 1 (TRPV1) channel, in addition to its agonist activity at cannabinoid type 1 (CB1) receptor. In the midbrain dorsolateral periaqueductal gray (dlPAC) our previous data showed that CB1 activation induces anxiolytic-like effects. However, the rote of TRPV1 has remained unclear. Thus, in the present study we tested the hypothesis that this channel would contribute to the modulation of anxiety-like behaviour in the dlPAG. Mate Wistar rats received local injections of the TRPV1 antagonist capsazepine (10-60 nmol) and were submitted to the elevated plus-maze (EPM) and to the Vogel test. In addition, animals received local injections of capsaicin (0.01-1nmol), a TRPV1 agonist, and were tested in the same models. In accordance with our hypothesis, capsazepine produced anxiolytic-like effects both in the EPM and in the Vogel test. Capsaicin mimicked these results, which might be attributed to its ability to quickly desensitize the channel. Altogether, our data suggest that, while CB1 receptors seem to inhibit aversive responses in the dlPAG, TRPV1 could facilitate them. Thus, CB1 and TRPV1 may have opposite functions in modulating anxiety-like behaviour in this region. (C) 2008 Elsevier B.V. and ECNP. All rights reserved.

Cellular prion protein modulates defensive attention and innate fear-induced behaviour evoked in transgenic mice submitted to an agonistic encounter with the tropical coral snake Oxyrhopus guibei

The cellular prion protein (PrPC) is a neuronal anchored glycoprotein that has been associated with distinct functions in the CNS, such as cellular adhesion and differentiation, synaptic plasticity and cognition. Here we investigated the putative involvement of the PrPC in the innate fear-induced behavioural reactions in wild-type (WT), PrPC knockout (Prnp(0/0)) and the PrPC overexpressing Tg-20 mice evoked in a prey versus predator paradigm. The behavioural performance of these mouse strains in olfactory discrimination tasks was also investigated. When confronted with coral snakes, mice from both Prnp(0/0) and Tg-20 strains presented a significant decrease in frequency and duration of defensive attention and risk assessment, compared to WT mice. Tg-20 mice presented decreased frequency of escape responses, increased exploratory behaviour, and enhancement of interaction with the snake, suggesting a robust fearlessness caused by PrPC overexpression. Interestingly, there was also a discrete decrease in the attentional defensive response (decreased frequency of defensive alertness) in Prnp(0/0) mice in the presence of coral snakes. Moreover, Tg-20 mice presented an increased exploration of novel environment and odors. The present findings indicate that the PrPC overexpression causes hyperactivity, fearlessness, and increased preference for visual, tactile and olfactory stimuli-associated novelty, and that the PrPC deficiency might lead to attention deficits. These results suggest that PrPC exerts an important role in the modulation of innate fear and novelty-induced exploration. (C) 2008 Published by Elsevier B.V.