Kinematic and Mechanical Profile of the Self-Actuation of Thermosalient Crystal Twins of 1,2,4,5-Tetrabromobenzene: A Molecular Crystalline Analogue of a Bimetallic Strip

A paradigm shift from hard to flexible, organic-based optoelectronics requires fast and reversible mechanical response from actuating materials that are used for conversion of heat or light into mechanical motion. As the limits in the response times of polymer-based actuating materials are reached, which are inherent to the less-than-optimal coupling between the light/heat and mechanical energy in them, 1 a conceptually new approach to mechanical actuation is required to leapfrog the performance of organic actuators. Herein, we explore single crystals of 1,2,4,5-tetrabromobenzene (TBB) as actuating elements and establish relations between their kinematic profile and mechanical properties. Centimeter-size acicular crystals of TBB are the only naturally twinned crystals out of about a dozen known materials that exhibit the thermosalient effect-an extremely rare and visually impressive crystal locomotion. When taken over a phase transition, crystals of this material store mechanical strain and are rapidly self-actuated to sudden jumps to release the internal strain, leaping up to several centimeters. To establish the structural basis for this colossal crystal motility, we investigated the mechanical profile of the crystals from macroscale, in response to externally induced deformation under microscope, to nanoscale, by using nanoindentation. Kinematic analysis based on high-speed recordings of over 200 twinned TBB crystals exposed to directional or nondirectional heating unraveled that the crystal locomotion is a kinematically complex phenomenon that includes at least six kinematic effects. The nanoscale tests confirm the highly elastic nature, with an elastic deformation recovery (60%) that is far superior to those of molecular crystals reported earlier. This property appears to be critical for accumulation of stress required for crystal jumping. Twinned crystals of TBB exposed to moderate directional heating behave as all-organic analogue of a bimetallic `strip, where the lattice misfit between the two crystal components drives reveriible deformation of the crystal.

Mechanical effects of the self-organization of dislocations and related critical characteristics

The effects of the dislocation pattern formed due to the self-organization of the dislocations in crystals on the macroscopic hardening and dynamic internal friction (DIF) during deformation are studied. The classic dislocation models for the hardening and DIF corresponding to the homogeneous dislocation configuration are extended to the case for the non-homogeneous one. In addition, using the result of dislocation patterning deduced from the non-linear dlislocation dynamics model for single slip, the correlation between the dislocation pattern and hardening as well as DIF is obtained. It is shown that in the case of the tension with a constant strain rate, the bifurcation point of dislocation patterning corresponds to the turning point in the stress versus strain and DIF versus strain curves. This result along with the critical characteristics of the macroscopic behavior near the bifurcation point is microscopically and macroscopically in agreement with the experimental findings on mono-crystalline pure aluminum at temperatures around 0.5T(m). The present study suggests that measuring the DIF would be a sensitive and useful mechanical means in order to study the critical phenomenon of materials during deformation.

The Metabolic Core and Catalytic Switches Are Fundamental Elements in the Self-Regulation of the Systemic Metabolic Structure of Cells

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Uniformity enhancement of the self-organized InAs quantum dots

Growth interruption was introduced after the deposition of GaAs cap layer, which is thinner than the height of quantum dots. Uniformity of quantum dots has been enhanced because the full-width of half-maximum of photoluminescence decrease from 80 to 27 meV in these samples as the interruption time is increased. Meanwhile, we have observed that the peak position of photoluminescence is a function of interruption time, which can be used to modulate energy level of quantum dots. All of the phenomenon mentioned above can be attributed to the diffusion of In atoms from the tops of InAs islands to the top of GaAs cap layer caused by the difference between the surface energies of InAs and GaAs. (C) 1999 Elsevier Science B.V. All rights reserved.

It takes guts for tolerance: The phenomenon of oral tolerance and the regulation of autoimmune response

The intestinal tract is a peculiar environment due to its constant contact with the microbiota agents, food antigens and other molecules. Such exposure requires the establishment of important regulatory mechanisms in order to avoid inflammatory response and self aggression. In this context, the GALT plays a very relevant role due to the presence of several different cellular populations which are the main players in this phenomenon. Moreover, it was described a while ago that the oral ingestion of a given molecule is able to induce systemic tolerance to the same molecule when it is used as an immunogen by parenteral route, known as oral tolerance. This observation led researches to use these mechanisms to induce tolerance against cognate antigens of different autoimmune diseases. In this context, in this review we focused on several tolerance inducing mechanisms which are relevant not only for the maintenance of intestinal tract but also for the suppression of T effector cells, such as Th1, Th2 and the newly described Th17 cells. To name a few, CD103(+) dendritic cells, Tr1 cells derived IL-10 secretion, Foxp3 conversion and CD4(+)LAP(+) regulatory cells induction are among the recently described features of the tolerogenic environment of the intestinal tract. (C) 2009 Elsevier B.V. All rights reserved.

Constructing an Indigenous Model of the Self to Address Cultural and Mental Health Issues in the Canadian Subarctic

Since the last decades, academic research has paid much attention to the phenomenon of revitalizing indigenous cultures and, more precisely, the use of traditional indigenous healing methods both to deal with individuals' mental health problems and with broader cultural issues. The re-evaluation of traditional indigenous healing practices as a mode of psychotherapeutic treatment has been perhaps one of the most interesting sociocultural processes in the postmodern era. In this regard, incorporating indigenous forms of healing in a contemporary framework of indigenous mental health treatment should be interpreted not simply as an alternative therapeutic response to the clinical context of Western psychiatry, but also constitutes a political response on the part of ethno-cultural groups that have been stereotyped as socially inferior and culturally backward. As a result, a postmodern form of "traditional healing" developed with various forms of knowledge, rites and the social uses of medicinal plants, has been set in motion on many Canadian indigenous reserves over the last two decades.

‘State failure’ and the extraterritorial use of force in self-defence against non-state actors

The thesis is first and foremost the examination of the notion and consequences of ‘state failure’ in international law. The disputes surrounding criteria for creation and recognition of states pertain to efforts to analyse legal and factual issues unravelling throughout the continuing existence of states, as best evidenced by the ‘state failure’ phenomenon. It is argued that although the ‘statehood’ of failed states remains uncontested, their sovereignty is increasingly considered to be dependent on the existence of effective governments. The second part of this thesis focuses on the examinations of the legal consequences of the continuing existence of failed states in the context of jus ad bellum. Since the creation of the United Nations the ability of states to resort to armed force without violating what might be considered as the single most important norm of international law, has been considerably limited. State failure and increasing importance of non-state actors has become a greatly topical issue within recent years in both scholarship and the popular imagination. There have been important legal developments within international law, which have provoked much academic, and in particular, legal commentary. On one level, the thesis contributes to this commentary. Despite the fact that the international community continues to perpetuate a notion of ‘statehood’ which allows the state-centric system of international law to exist, when dealing with practical and political realities of state failure, international law may no longer consider external sovereignty of states as an undeniable entitlement to statehood. Accordingly, the main research question of this thesis is whether the implicit and explicit invocation of the state failure provides sufficient legal basis for the intervention in self-defence against non-state actors in located in failed states. It has been argued that state failure has a profound impact, the extent of which is yet to be fully explored, on the modern landscape of peace and security.

Haematidrosis: The Rare Phenomenon of Sweating Blood

Objectives: Haematidrosis, also known as haematohidrosis, is a very rare condition where blood is excreted with sweat. As only a few cases have been described in the literature, we present guidelines on management of this rare phenomenon. Case: A 44-year-old man presented with self-limited and spontaneous bleeding episodes from different parts of his body. This had started 2 weeks before admission after an episode of extreme emotional stress. Medical history and laboratory tests were normal. The microscopic examination of a sample of the fluid excreted confirmed all blood elements. Conclusion: The disorder is thought to be related to activation of the sympathetic nervous system. The use of benzodiazepines and beta blockers may be helpful in controlling the bleeding episodes and give some comfort to the patient.

Self-medication on the students of the school of health from Polytechnic Institute of Bragança

The self-medicatíon is a phenomenon more and more frequent and used for several years already, and tts incidence and dlstribution are related wtth the organizatíon and health system of each country. Following Medeiros thoughts (2011), this practíce conststs in the consumptíon of a medicine with the purpose of treating or relieving the symptoms and diseases or even promote self health, without using a professional prescription. Methods: With thts study, we intend to find the self-medication practice incidence on the students in the School of Health of Polytechnic Institute of Bragança (ESSa), identify the motives that lead these students to resort to this methods and identify the most used medicatíons. lt's a transversal descriptive, observational and quantítative study. To obtain the best results it was applied a questíonnaire built for that purpose. The statístícs analyses was made using Excel program. Our sample hás 219 students of the School of Health from Polytechntc Instítute of Bragança. Results: The studied sample includes 194 female and 25 male students distributed as follows: 36 frequenting Biomedical Laboratory Sdences, 26 Dietetics and Nutrition, 99 Nursing, 33 Gerontology and 22 studying Pharmacy. The self-medicatíon prevalence was 98%. The most used medicines was the analgesics and antipyretics with 86%. The most prevalent reason for the use of self-medicatíon was the thought that the disease was a "minor health issue". It was also considered a risky practice by 77% of the students. Conclusions: The self-medication is an evident practíce on the ESSa students. This results reveal some contradiction stnce the most consider 1t as a risky practíce, however it is, stíll, practíced.

The use of technology-based self-service on assessments of consumer satisfaction and consumer commitment

Technology-based self-service (TBSS) enables consumers to complete services themselves using a technological interface. As evaluations of consumer satisfaction and commitment have typically focused on interpersonal interactions, the effect of TBSS on these is under researched . This paper explores the impact of TBSS on consumer satisfaction and on a multidimensional measure of consumer commitment.Data are collected from 241 hotel guests. The results suggest personal-service is more important for satisfaction and commitment. This has implications for marketing as the benefits of adopting TBSS are not clear. Multi-dimensional commitment provides some interesting findings and suggests the need for further research into TBSS and commitment.

An investigation of the social learning and symbolic interaction models for the development of self-concepts and self-esteem

Two studies were conducted to investigate empirical support for two models relating to the development of self-concepts and self-esteem in upper-primary school children. The first study investigated the social learning model by examining the relationship between mothers' and fathers' self-reported self-concepts and self-esteem and the self-reported self-concepts and self-esteem of their children. The second study investigated the symbolic interaction model by examining the relationship between children's perception of the frequency of positive and negative statements made by parents and their self-reported self-concepts and self-esteem. The results of these studies suggested that what parents say to their children and how they interact with them is more closely related to their children's self-perceptions than the role of modelling parental attitudes and behaviours. The findings highlight the benefits of parents talking positively to their children.

Youth, personhood and 'practices of the self'

In contrast to most previous research in the field, this paper argues that the concept of 'youth' is best understood as an example of the governmental formation of a specific type of person. It is constructed at the intersection of a variety of diverse problematisations, being produced by the processes of individuation/ normalisation and the regulation of relations of time. Within programs such as those pertinent to the management of sex, an array of technologies structure the practices by which individuals pattern their own conduct - thereby fashioning a kind of habitus. This forms part of a general strategy of enrolling the objects of these programs in their own self-reformation. Consequently, `youth' can be understood as `the doing of specific types of work on the self'. By utilising this framework, the paper not only seeks to identify and better understand some of the sexual subjectivities associated with the construction of youth, it also seeks to offer some new directions for research in the area.