P2X4 receptors interact with both P2X2 and P2X7 receptors in the form of homotrimers

BACKGROUND AND PURPOSE The P2X receptor family consists of seven subunit types - P2X1-P2X7. All but P2X6 are able to assemble as homotrimers. In addition, various subunit permutations have been reported to form heterotrimers. Evidence for heterotrimer formation includes co-localization, co-immunoprecipitation and the generation of receptors with novel functional properties; however, direct structural evidence for heteromer formation, such as chemical cross-linking and single-molecule imaging, is available in only a few cases. Here we examined the nature of the interaction between two pairs of subunits - P2X2 and P2X4, and P2X4 and P2X7. EXPERIMENTAL APPROACH We used several experimental approaches, including in situ proximity ligation, co-immunoprecipitation, co-isolation on affinity beads, chemical cross-linking and atomic force microscopy (AFM) imaging. KEY RESULTS Both pairs of subunits co-localize upon co-transfection, interact intimately within cells, and can be co-immunoprecipitated and co-isolated from cell extracts. Despite this, chemical cross-linking failed to show evidence for heteromer formation. AFM imaging of isolated receptors showed that all three subunits had the propensity to form receptor dimers. This self-association is likely to account for the observed close interaction between the subunit pairs, in the absence of true heteromer formation. CONCLUSIONS AND IMPLICATIONS We conclude that both pairs of receptors interact in the form of distinct homomers. We urge caution in the interpretation of biochemical evidence indicating heteromer formation in other cases.

Lead stimulus modality change and the attentional modulation of the acoustic and electrical blink reflex

Two experiments investigated the effects of the sensory modality of the lead and of the blink-eliciting stimulus during lead stimulus modality change on blink modulation at lead intervals of 2500 and 3500 ins. Participants were presented with acoustic, visual, or tactile change stimuli after habituation training with lead stimuli from the same or a different sensory modality. In Experiment 1, latency and magnitude of the acoustic blink were facilitated during a change to acoustic or visual lead stimuli, but not during a change to tactile lead stimuli. After habituation to acoustic lead stimuli, blink magnitude was smaller during tactile change stimuli than during habituation stimuli. The latter finding was replicated in Experiment 2 in which blink was elicited by electrical stimulation of the trigeminal nerve. The consistency of the findings across different combinations of lead stimulus and blink-eliciting stimulus modalities does not support a modality-specific account of attentional blink modulation. Rather, blink modulation during generalized orienting reflects modality non-specific processes, although modulation may not always be found during tactile lead stimuli. (C) 2002 Elsevier Science B.V. All rights reserved.

Relationship between cranio-cervical flexion range of motion and pressure change during the cranio-cervical flexion test

The purpose of this study was to quantify the sagittal angular displacement of the head (cranio-cervical flexion) for the five incremental stages of the cranio-cervical flexion test (CCFT). Range of cranio-cervical flexion during the CCFT was measured using a digital imaging method in 20 healthy volunteer subjects. The intra- and inter-rater reliability of the digital imaging technique for the assessment of this movement were also examined. The results of this study demonstrated a linear relationship between the incremental pressure targets of the CCFT and the percentages of full range cranio-cervical flexion range of motion (ROM) measured in the supine lying position of the test using a digital imaging technique. A mean of 22.9% full range cranio-cervical flexion was used to reach the first pressure target of the CCFT followed by linear increments up to 76.6% for the last stage of the test. An increasing amount of cranio-cervical flexion ROM was used to achieve the five successive stages of the CCFT reflecting an increasing contractile demand on the deep cervical flexor muscles. Excellent inter-rater (ICC = 0.994) and intra-rater reliability (ICC = 0.988-0.998) were demonstrated for the angular measurements using this digital imaging technique. (C) 2003 Elsevier Science Ltd. All rights reserved.

Vicarious dissonance: Attitude change from the inconsistency of others

Three studies support the vicarious dissonance hypothesis that individuals change their attitudes when witnessing members of important groups engage in inconsistent behavior. Study 1, in which participants observed an actor in an induced-compliance paradigm, documented that students who identified with their college supported an issue more after hearing an ingroup member make a counterattitudinal speech in favor of that issue. In Study 2, vicarious dissonance occurred even when participants did not hear a speech, and attitude change was highest when the speaker was known to disagree with the issue. Study 3 showed that speaker choice and aversive consequences moderated vicarious dissonance, and demonstrated that vicarious discomfort-the discomfort observers imagine feeling if in an actor's place-was attenuated after participants expressed their revised attitudes.

Governance of global climate change in the Brazilian Amazon: the case of Amazonian municipalities of Brazil

With regards to the debate about governance of climate change, it should be assumed that the Amazon region plays an important role, as this large area is highly vulnerable to its effects. In this sense, this article aims to discuss how some Amazonian municipalities of Brazil have been taking part in the complexes and multilayered processes of climate governance.

Organizational and accounting change within the context of the environmental agenda: evidence from Portugal

Purpose – The purpose of this paper is to explore the process of organizational change undergone by a large Portuguese business group within the context of the environmental agenda and the role of accounting as a mechanism for change. Design/methodology/approach – The paper reports the results of a case study conducted between 2006 and 2009. Information was obtained from semi-structured interviews and secondary sources. Organizational changes were analyzed using Laughlin’s model in order to identify which category reflected most of the changes introduced to address environmental matters. Findings – This paper offers evidence that change is not a homogeneous phenomenon. Additionally, it confirms previous studies’ findings which found that accounting did not play a significant role in the process of organizational change within the context of the environmental agenda. Originality/value – This paper seeks to complement the research in this area by integrating observations from a case study into an existing model of levels of organizational change according to how a Portuguese business group incorporated environmental issues into its processes, policies and corporate culture.

MICROFINANCE AND CLIMATE CHANGE IMPACTS: THE CASE OF AGROAMIGO IN BRAZIL

ABSTRACTThis paper reports an empirical case study on the interface between microfinance and climate change actions. Climate change, which until recently seemed a luxury for the microfinance sector, now appears to be crucial for its future. For their low adaptive capacity, the millions of microfinance clients worldwide happen to be the most vulnerable to a changing climate. However, such an arena is still blurred from an academic viewpoint, and inexistent among Brazilian academia. Therefore, by investigating Brazil’s largest rural MFI, Agroamigo, we aim at providing an empirical contribution to green microfinance. The main conclusion is that, albeit Agroamigo offers important links to climate change initiatives, it will need to take better account of specific vulnerabilities and risks to protect its portfolio and clients better from climate change impacts.

Oral health in the family health strategy: a change of practices or semantics diversionism

OBJECTIVE:To evaluate public health dentistry practices of two different family health models. METHODS: Qualitative study conducted with data obtained from focus groups consisting of 58 dentists working in the Family Health Strategy for at least three years between August-October, 2006. The Paideia Family Health Approach was used in the city of Campinas and the Oral Health Initiative as part of the Family Health Strategy was implemented in the city of Curitiba, Southeastern and Southern Brazil, respectively. Data was analyzed using the hermeneutic-dialectic method. Analysis indicators were employed to indicate backwardness, stagnation or progress in oral health practices effective from the implementation of the strategies referred. The indicators used were: work process; interdisciplinary approach; territorialization; capacity building of human resources; health promotion practices; and responsiveness to users' demands. RESULTS: There was progress in user access to services, humanization of health care, patient welcoming and patient-provider relationship. The results related to health promotion practices, territorialization, interdisciplinary approach and resource capacity building indicated a need for technical and operational enhancements in both cities. CONCLUSIONS: Both models have brought about important advances in terms of increased access to services and humanization of health care. Universal access to oral health at all levels of complexity was not achieved in both cities studied. Local health managers and oral health program coordinators must bring more weight to bear in the arena that defines public policy priorities.

Detecting and evaluating land cover change in the eastern half of East Timor (1972-2011)

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.