Diamagnetism versus Paramagnetism in charged spin-1 Bose gases

It has been suggested that either diamagnetism or paramagnetism of Bose gases, due to the charge or spin degrees of freedom respectively, appears solely to be extraordinarily strong. We investigate magnetic properties of charged spin-1 Bose gases in external magnetic field, focusing on the competition between the diamagnetism and paramagnetism, using the Lande-factor $g$ of particles to evaluate the strength of paramagnetic effect. We propose that a gas with $g<{1/\sqrt{8}}$ exhibits diamagnetism at all temperatures, while a gas with $g>{1/2}$ always exhibits paramagnetism. Moreover, a gas with the Lande-factor in between shows a shift from paramagnetism to diamagnetism as the temperature decreases. The paramagnetic and diamagnetic contributions to the total magnetization density are also calculated in order to demonstrate some details of the competition.Comment: 6 pages, 5 figure

Dual role of nNOS in ischemic injury and preconditioning

<p>Abstract</p> <p>Background</p> <p>Nitric oxide (NO) is cardioprotective and a mediator of ischemic preconditioning (IP). Endothelial nitric oxide synthase (eNOS) is protective against myocardial ischemic injury and a component of IP but the role and location of neuronal nitric oxide synthase (nNOS) remains unclear. Therefore, the aims of these studies were to: (i) investigate the role of nNOS in ischemia/reoxygenation-induced injury and IP, (ii) determine whether its effect is species-dependent, and (iii) elucidate the relationship of nNOS with mitoK_ATPchannels and p38MAPK, two key components of IP transduction pathway.</p> <p>Results</p> <p>Ventricular myocardial slices from rats and wild and nNOS knockout mice, and right atrial myocardial slices from human were subjected to 90 min ischemia and 120 min reoxygenation (37°C). Specimens were randomized to receive various treatments (n = 6/group). Both the provision of exogenous NO and the inhibition of endogenous NO production significantly reduced tissue injury (creatine kinase release, cell necrosis and apoptosis), an effect that was species-independent. The cardioprotection seen with nNOS inhibition was as potent as that of IP, however, in nNOS knockout mice the cardioprotective effect of non-selective NOS (L-NAME) and selective nNOS inhibition and also that of IP was blocked while the benefit of exogenous NO remained intact. Additional studies revealed that the cardioprotection afforded by exogenous NO and by inhibition of nNOS were unaffected by the mitoK_ATPchannel blocker 5-HD, although it was abrogated by p38MAPK blocker SB203580.</p> <p>Conclusions</p> <p>nNOS plays a dual role in ischemia/reoxygenation in that its presence is necessary to afford cardioprotection by IP and its inhibition reduces myocardial ischemic injury. The role of nNOS is species-independent and exerted downstream of the mitoK_ATPchannels and upstream of p38MAPK.</p

Bose-Einstein condensation of the magnetized ideal Bose gas

We study the charged non-relativistic Bose gas interacting with a constant magnetic field but which is otherwise free. The notion of Bose-Einstein condensation for the three dimensional case is clarified, and we show that although there is no condensation in the sense of a phase transition, there is still a maximum in the specific heat which can be used to define a critical temperature. Although the absence of a phase transition persists for all values of the magnetic field, we show how as the magnetic field is reduced the curves for the specific heat approach the free field curve. For large values of the magnetic field we show that the gas undergoes a "dimensional reduction" and behaves effectively as a one-dimensional gas except at very high temperatures. These general features persist for other spatial dimensions D and we show results for D=5. Finally we examine the magnetization and the Meissner-Ochsenfeld effect.Comment: 4 pages RevTex 2 column format with 4 eps figures, uses epsf. Replaced version has missing acknowledgements and a discussion of two references is corrected thanks to discussions with J. Daicic and N. Franke

Structured evaluation of virtual environments for special-needs education

This paper describes the development of a structured approach to evaluate experiential and communication virtual learning environments (VLEs) designed specifically for use in the education of children with severe learning difficulties at the Shepherd special needs school in Nottingham, UK. Constructivist learning theory was used as a basis for the production of an evaluation framework, used to evaluate the design of three VLEs and how they were used by students with respect to this learning theory. From an observational field study of student-teacher pairs using the VLEs, 18 behaviour categories were identified as relevant to five of the seven constructivist principles defined by Jonassen (1994). Analysis of student-teacher behaviour was used to provide support for, or against, the constructivist principles. The results show that the three VLEs meet the constructivist principles in very different ways and recommendations for design modifications are put forward

Development of an online diary for longitudinal travel / activity surveys

Motivated by the continued search for methods to reduce participant burden and non-response, and improve the quality of travel data, this paper details the development of a new online travel/activity diary to support a major longitudinal investigation of travel in Sydney, Australia. The diary employs several innovative features designed to simplify the process of data entry, and improve participant recall and completeness of travel, including auto-fills, prompts, trip editing capabilities, favourite trips and a dragand- drop technique for capturing travel mode. An additional innovation is the ability to view a GPS-based Google map of daily travel while completing the diary to assist with recall. The diary is tested on 37 participants, with a range of diagnostics provided to assess their comprehension and interaction with the diary, reaction and burden, and completeness of data provided. Overall, 89% of participants complete all seven days of the diary with 75% indicating no issues once they become accustomed to how it works. Trip entry times average around two minutes/trip with three-quarters of trips entered within 24 hours of being made and 96% of trips provided with complete details. In terms of the GPS component, while the data itself is of variable quality and the optional viewing of trips is lower than anticipated, those carrying a GPS report more trips/day and segments/day, fewer missing days, and provide more complete trip data

Effects of system- and media-driven immersive capabilities on presence and affective experience

Virtual reality (VR) is receiving widespread attention as a delivery tool for exposure therapies. The advantage offered by VR over traditional technology is a greater sense of presence and immersion, which magnifies user effects and enhances the effectiveness of exposure-based interventions. The current study systematically examined the basic factors involved in generating presence in VR as compared to standard technology, namely (1) system-driven factors that are exclusive to VR devices while controlling general factors such as field of view and image quality; (2) media-driven factors of the virtual environment eliciting motivational salience through different levels of arousal and valence (relaxing, exciting and fear evoking stimuli); and (3) the effects of presence on magnifying affective response. Participants (N = 14) watched 3 different emotionally salient videos (1 × fear evoking, 1 × relaxing and 1 × exciting) in both viewing modes (VR and Projector). Subjective scores of user experience were collected as well as objective EEG markers of presence (frontal alpha power, theta/beta ratio). Subjective and objective presence was significantly greater in the VR condition. There was no difference in subjective or objective presence for stimulus type, suggesting presence is not moderated by arousal, but may be reliant on activation of motivational systems. Finally, presence did not magnify feelings of relaxation or excitement, but did significantly magnify users’ experience of fear when viewing fear evoking stimuli. This is in line with previous literature showing strong links between presence and generation of fear, which is vital in the efficacy of exposure therapies

The neural correlates of reinforcement sensitivity theory: a systematic review of the (f)MRI literature

Objectives: Reinforcement Sensitivity Theory (RST) is a theory of motivation, emotion and learning, that has been translated into an account of personality. RST proposes neural structures that form the basis of systems responsible for reward (BAS), punishment (FFFS) and conflict processing (BIS). This systematic review collated studies examining psychometric measures of RST alongside structural and function MRI data to (i) examine how psychometric RST is associated with the proposed neural topologies of RST, (ii) identify any common associations between psychometric RST and other brain regions, and (iii) provide recommendations for advancing the current literature base. Methods: Initial search terms identified 10952 papers. After processing, 39 papers that investigated the association between RST scales and neural functioning in healthy adult samples were included in this review. Results: There was general support for associations between the BAS and the structure/activity of the pre-frontal cortex and ventral striatum with some additional findings for the ventral pallidum and ventral tegmental area. There was also some support for associations between BIS/FFFS and structure/activity of frontal regions, cingulate cortices and the amygdala. Conclusions: Overall, psychometric correlates of RST were associated with activity in proposed neural circuitry, with the most consistent support being found for the BAS; however, psychometric and experimental limitations still hamper the differentiation of the BIS and FFFS systems in their activation of deeper brain networks. Future studies need to include revised RST scales that separate the BIS and FFFS and implement more rigorous tasks that allow for the examination of each system both independently and codependently

Introducing genetic testing for cardiovascular disease in primary care: a qualitative study

Background: While primary care systematically offers conventional cardiovascular risk assessment, genetic tests for coronary heart disease (CHD) are increasingly commercially available to patients. It is unclear how individuals may respond to these new sources of risk information. Aim: To explore how patients who have had a recent conventional cardiovascular risk assessment, perceive additional information from genetic testing for CHD. Design and setting: Qualitative interview study in 12 practices in Nottinghamshire from both urban and rural settings. Method: Interviews were conducted with 29 adults, who consented to genetic testing after having had a conventional cardiovascular risk assessment. Results: Individuals’ principal motivation for genetic testing was their family history of CHD and a desire to convey the results to their children. After testing, however, there was limited recall of genetic test results and scepticism about the value of informing their children. Participants dealt with conflicting findings from the genetic test, family history, and conventional assessment by either focusing on genetic risk or environmental lifestyle factors. In some participants, genetic test results appeared to reinforce healthy behaviour but others were falsely reassured, despite having an ‘above-average’ conventional cardiovascular risk score. Conclusion: Although genetic testing was acceptable, participants were unclear how to interpret genetic risk results. To facilitate healthy behaviour, health professionals should explore patients’ understanding of genetic test results in light of their family history and conventional risk assessment