The control of global brain dynamics: opposing actions of frontoparietal control and default mode networks on attention

Understanding how dynamic changes in brain activity control behavior is a major challenge of cognitive neuroscience. Here, we consider the brain as a complex dynamic system and define two measures of brain dynamics: the synchrony of brain activity, measured by the spatial coherence of the BOLD signal across regions of the brain; and metastability, which we define as the extent to which synchrony varies over time. We investigate the relationship among brain network activity, metastability, and cognitive state in humans, testing the hypothesis that global metastability is “tuned” by network interactions. We study the following two conditions: (1) an attentionally demanding choice reaction time task (CRT); and (2) an unconstrained “rest” state. Functional MRI demonstrated increased synchrony, and decreased metastability was associated with increased activity within the frontoparietal control/dorsal attention network (FPCN/DAN) activity and decreased default mode network (DMN) activity during the CRT compared with rest. Using a computational model of neural dynamics that is constrained by white matter structure to test whether simulated changes in FPCN/DAN and DMN activity produce similar effects, we demonstate that activation of the FPCN/DAN increases global synchrony and decreases metastability. DMN activation had the opposite effects. These results suggest that the balance of activity in the FPCN/DAN and DMN might control global metastability, providing a mechanistic explanation of how attentional state is shifted between an unfocused/exploratory mode characterized by high metastability, and a focused/constrained mode characterized by low metastability

Crew Resource Management and Its Possible Role in Nursing Risk Management

Crew Resource Management (CRM) was introduced within the aviation industry in the late 1970s after an aircraft ran out of fuel whilst the pilots were trying to solve an undercarriage problem. To reduce such errors and ultimately lower the probability of failure and the severity of risks that occur, training in CRM was rolled out across the whole industry. It has been successful over the last few years in major reductions in the number of crashes and fatalities in the commercial aviation sector. Nursing has similar concerns in that errors can ultimately result in fatalities. There are parallels in the needs and expectations of pilots and nurses to assess risk, reduce risk and deliver reliable and dependable professional services. In this paper the parallels of pilots and nurses demands are compared to assess if the lessons learned in aviation can assist nurses deliver procedures with lower risks. The analysis will draw on the demands and expectations and how they both deal with risk, challenging errors and ensuring that identified risks are not overlooked or ignored. Finally, suggestions of adopting, sharing and benchmarking between these two industries can adopt best practices so that both industries can learn from each other

The Development of a Scoring Tool for the Measurement of Performance in Managing Hypotension and Intra-Operative Cardiac Arrest during Spinal Anaesthesia for Caesarean Section

Background: At level one hospitals in South Africa a high annual number of maternal deaths occur due to the unrecognised/ untreated complications of spinal anaesthesia. The authors developed a clinical scenario and scoring system to measure intern performance in managing hypotension and cardiac arrest during spinal anaesthesia for caesarean section on a human patient simulator. This system was then subjected to tests of validity and reliability.Methods: The simulator-based clinical scenario was developed by two specialist anaesthesiologists. A modified Delphi technique was used to achieve consensus among 10 anaesthetic specialists regarding a standardised scoring system. A total of 20 medical officers with a Diploma in Anaesthesiology and 20 interns completed the scenario and were scored by two senior anaesthesiologists.Results: Medical officers scored an average of 252 and 246 points, whereas interns scored an average of 216 and 215 points (p = 0.005 and p = 0.013, respectively). The scoring instrument demonstrated high inter-assessor reliability with an intra-class correlation coefficient of 0.983.Conclusions: The scoring tool was shown to be valid and reliable. It offers a standardised assessment process and may be used to refine institutional intern training programmes, with a view to improving anaesthesia skills in community service medical officers.Keywords: Anaesthesia Spinal, Caesarean Section, Internship, Residency, Simulation, Simulato

Gravity from a fermionic condensate of a gauge theory

The most prominent realization of gravity as a gauge theory similar to the gauge theories of the standard model comes from enlarging the gauge group from the Lorentz group to the de Sitter group. To regain ordinary Einstein-Cartan gravity the symmetry must be broken, which can be accomplished by known quasi-dynamic mechanisms. Motivated by symmetry breaking models in particle physics and condensed matter systems, we propose that the symmetry can naturally be broken by a homogenous and isotropic fermionic condensate of ordinary spinors. We demonstrate that the condensate is compatible with the Einstein-Cartan equations and can be imposed in a fully de Sitter invariant manner. This lends support, and provides a physically realistic mechanism for understanding gravity as a gauge theory with a spontaneously broken local de Sitter symmetry.Comment: 16 page

Indigenous entrepreneurship: Closing the gap on local terms

Within the federal government ‘Closing the Gap’ policy context this paper reports on local entrepreneurial activities by local Yolngu people in East Arnhem Land in the Northern Territory. Particular attention is directed to members of the Rirratjingu clan in the town of Yirrkala. We describe how the activities of a local social enterprise offer pathways for the creation of income, employment and social capital within the local community and where the protection of cultural vitality and integrity is axiomatic. The findings point to the need for more flexible policy approaches, to enable the establishment and growth of Indigenous business activities outside the economic mainstream. We echo the calls in the literature for policy support for what has been described as the ‘hybrid economy’, which allows for participation in both economic and cultural activities

Australian indigenous social enterprise: Measuring performance

Purpose Using an integrated framework for performance management of nonprofit organisations, this paper presents an analysis of the activities of an Indigenous social enterprise in the town of Yirrkala in northeast Arnhem Land in the Northern Territory of Australia. The evaluation focuses on the social effectiveness of the organisation and its ability to help generate income and employment and drive social capital creation. Design/methodology/approach The analysis is informed by data derived from ‘yarns’ with social enterprise staff and semi-structured interviews conducted with key informants who were selected using snowball sampling. Data were transcribed and analysed thematically. Findings The analysis reveals that the organisation provides a successful community-based pathway to increasing Indigenous economic participation on local terms at a time of regional economic decline and high levels of Indigenous unemployment nationally. Practical implications The measured effectiveness of Nuwul highlights the need for targeted policy support for Indigenous enterprises and that social entrepreneurship is far more likely to be successful in a supportive government policy environment. a critical need for government-initiated policies to encourage the formation of Indigenous social enterprises that are entrepreneurial and innovative in their solutions to poverty and marginalization. Such policies should not only aid the establishment of Indigenous ventures but also facilitate their long-term growth and sustainability. Originality/value While Indigenous entrepreneurial activities have been found to be effective in addressing Indigenous disadvantage in Australia, little is known about their community impact. The article provides original empirically grounded research on the measurement of Indigenous entrepreneurial activities and their wider community impact. The data show, against the backdrop of mixed results of government efforts to drive Indigenous economic mainstreaming, that the entrepreneurial activities analyzed in this paper are an example of more flexible and culturally appropriate pathways to achieving Indigenous equality in rural and remote regions of Australia

Space suit

A pressure suit for high altitude flights, particularly space missions is reported. The suit is designed for astronauts in the Apollo space program and may be worn both inside and outside a space vehicle, as well as on the lunar surface. It comprises an integrated assembly of inner comfort liner, intermediate pressure garment, and outer thermal protective garment with removable helmet, and gloves. The pressure garment comprises an inner convoluted sealing bladder and outer fabric restraint to which are attached a plurality of cable restraint assemblies. It provides versitility in combination with improved sealing and increased mobility for internal pressures suitable for life support in the near vacuum of outer space

A right-handed isotropic medium with a negative refractive index

The sign of the refractive index of any medium is soley determined by the requirement that the propagation of an electromagnetic wave obeys Einstein causality. Our analysis shows that this requirement predicts that the real part of the refractive index may be negative in an isotropic medium even if the electric permittivity and the magnetic permeability are both positive. Such a system may be a route to negative index media at optical frequencies. We also demonstrate that the refractive index may be positive in left-handed media that contain two molecular species where one is in its excited state.Comment: 4.1 pages, 4 figures, submitted to Physical Review Letter