Rarefied gas effects on the aerodynamics of high area-to-mass ratio spacecraft in orbit

The aerodynamic situation of a satellite-on-a-chip operating in low Earth orbit bears some resemblance to a classical Crookes radiometer. The large area-to-mass ratio characteristic of a SpaceChip means that very small surface-dependent forces produce non-negligible accelerations that can significantly alter its orbit. When the temperature of a SpaceChip changes, the drag force can be changed: if the temperature increases, the drag increases (and vice versa). Analytical expressions available in the literature that describe the change in drag coefficient with orbit altitude and SpaceChip temperature compare well with our direct simulation Monte Carlo results presented here. It is demonstrated that modifying the temperature of a SpaceChip could be used for relative orbit control of individual SpaceChips in a swarm, with a maximum change in position per orbit of 50 m being achievable at 600 km altitude

Internal agent states : experiments using the swarm leader concept

In recent years, an understanding of the operating principles and stability of natural swarms has proven to be a useful tool for the design and control of artificial robotic agents. Many robotic systems, whose design or control principals are inspired by behavioural aspects of real biological systems such as leader-follower relationship, have been developed. We introduced an algorithm which successfully enhances the navigation performance of a swarm of robots using the swarm leader concept. This paper presents some applications based on that work using the simulations and experimental implementation using a swarming behaviour test-bed at the University of Strathclyde. Experimental and simulation results match closely in a way that confirms the efficiency of the algorithm as well as its applicability

Blocked dihydropteridines as nitric oxide synthase activators

It has been shown that 6-acetyl-7,7-dimethyl-5,6,7,8-tetrahydropteridin-4(3H)-one can act as a competent cofactor for the production of nitric oxide by neuronal nitric oxide synthase (nNOS). More information was sought on the structural features that could contribute to strong binding within the enzyme whilst maintaining a fast electron transfer rate. This study was concerned with expansion at the C2-position of the pteridine scaffold. The evidence suggests that expansion at the C2-position had a deleterious effect with respect to Km and as a consequence electron transfer rate. Unexpectedly, several lines of evidence suggested that a methyl substituent on nitrogen at C2 reduced the electron density in the pyrimidine and dihydropterin rings

Development of a wireless intra-ocular pressure monitoring system for incorporation into a therapeutic glaucoma drainage implant

http://spiedigitallibrary.org/journals/doc/SPIEDL-home/proc

Identifying the barriers and enablers for a triage, treatment, and transfer clinical intervention to manage acute stroke patients in the emergency department : A systematic review using the theoretical domains framework (TDF)

Background Clinical guidelines recommend that assessment and management of patients with stroke commences early including in emergency departments (ED). To inform the development of an implementation intervention targeted in ED, we conducted a systematic review of qualitative and quantitative studies to identify relevant barriers and enablers to six key clinical behaviours in acute stroke care: appropriate triage, thrombolysis administration, monitoring and management of temperature, blood glucose levels, and of swallowing difficulties and transfer of stroke patients in ED. Methods Studies of any design, conducted in ED, where barriers or enablers based on primary data were identified for one or more of these six clinical behaviours. Major biomedical databases (CINAHL, OVID SP EMBASE, OVID SP MEDLINE) were searched using comprehensive search strategies. The barriers and enablers were categorised using the theoretical domains framework (TDF). The behaviour change technique (BCT) that best aligned to the strategy each enabler represented was selected for each of the reported enablers using a standard taxonomy. Results Five qualitative studies and four surveys out of the 44 studies identified met the selection criteria. The majority of barriers reported corresponded with the TDF domains of “environmental, context and resources” (such as stressful working conditions or lack of resources) and “knowledge” (such as lack of guideline awareness or familiarity). The majority of enablers corresponded with the domains of “knowledge” (such as education for physicians on the calculated risk of haemorrhage following intravenous thrombolysis [tPA]) and “skills” (such as providing opportunity to treat stroke cases of varying complexity). The total number of BCTs assigned was 18. The BCTs most frequently assigned to the reported enablers were “focus on past success” and “information about health consequences.” Conclusions Barriers and enablers for the delivery of key evidence-based protocols in an emergency setting have been identified and interpreted within a relevant theoretical framework. This new knowledge has since been used to select specific BCTs to implement evidence-based care in an ED setting. It is recommended that findings from similar future reviews adopt a similar theoretical approach. In particular, the use of existing matrices to assist the selection of relevant BCTs

Significant others, situations and infant feeding behaviour change processes: a serial qualitative interview study

BackgroundExclusive breastfeeding until six months followed by the introduction of solids and continued breastfeeding is recommended by the World Health Organisation. The dominant approach to achieving this has been to educate and support women to start and continue breastfeeding rather than understanding behaviour change processes from a broader perspective.MethodSerial qualitative interviews examined the influences of significant others on women’s feeding behaviour. Thirty-six women and 37 nominated significant others participated in 220 interviews, conducted approximately four weekly from late pregnancy to six months after birth. Responses to summative structured questions at the end of each interview asking about significant influences on feeding decisions were compared and contrasted with formative semi-structured data within and between cases. Analysis focused on pivotal points where behaviour changed from exclusive breastfeeding to introducing formula, stopping breastfeeding or introducing solids. This enabled us to identify processes that decelerate or accelerate behaviour change and understand resolution processes afterwards.ResultsThe dominant goal motivating behaviour change was family wellbeing, rather than exclusive breastfeeding. Rather than one type of significant other emerging as the key influence, there was a complex interplay between the self-baby dyad, significant others, situations and personal or vicarious feeding history. Following behaviour change women turned to those most likely to confirm or resolve their decisions and maintain their confidence as mothers.ConclusionsApplying ecological models of behaviour would enable health service organisation, practice, policy and research to focus on enhancing family efficacy and wellbeing, improving family-centred communication and increasing opportunities for health professionals to be a constructive influence around pivotal points when feeding behaviour changes. A paradigm shift is recommended away from the dominant approach of support and education of individual women towards a more holistic, family-centred narrative approach, whilst acknowledging that breastfeeding is a practical skill that women and babies have to learn

The Use of In-Space Manufactured Solid Foams for Aerocapture

No abstract available

Significant others, situations and their influences on infant feeding. Secondary analysis of data from: A prospective study exploring the early infant feeding experiences of parents and their significant others during the first 6 months of life: what would make a difference?

This study examines the range of influences on infant feeding behaviour from late pregnancy until six months after birth, which lead parents to introduce formula or solids, or to stop breastfeeding prior to the recommended six months. It reveals that a complex and dynamic combination of people, situations and personal experiences affect feeding behaviour initiation and maintenance and precipitate or prevent change

Significant others, situations and their influences on infant feeding. Secondary analysis of data from: A prospective study exploring the early infant feeding experiences of parents and their significant others during the first 6 months of life: what would make a difference?

This study examines the range of influences on infant feeding behaviour from late pregnancy until six months after birth, which lead parents to introduce formula or solids, or to stop breastfeeding prior to the recommended six months. It reveals that a complex and dynamic combination of people, situations and personal experiences affect feeding behaviour initiation and maintenance and precipitate or prevent change

A serial qualitative interview study of infant feeding experiences: idealism meets realism

Objective: To investigate the infant feeding experiences of women and their significant others from pregnancy until 6 months after birth to establish what would make a difference. Design: Qualitative serial interview study. Setting: Two health boards in Scotland. Participants: 72 of 541 invited pregnant women volunteered. 220 interviews approximately every 4 weeks with 36 women, 26 partners, eight maternal mothers, one sister and two health professionals took place. Results: The overarching theme was a clash between overt or covert infant feeding idealism and the reality experienced. This is manifest as pivotal points where families perceive that the only solution that will restore family well-being is to stop breast feeding or introduce solids. Immediate family well-being is the overriding goal rather than theoretical longer term health benefits. Feeding education is perceived as unrealistic, overly technical and rules based which can undermine women's confidence. Unanimously families would prefer the balance to shift away from antenatal theory towards more help immediately after birth and at 3-4 months when solids are being considered. Family-orientated interactive discussions are valued above breastfeeding-centred checklist style encounters. Conclusions: Adopting idealistic global policy goals like exclusive breast feeding until 6 months as individual goals for women is unhelpful. More achievable incremental goals are recommended. Using a proactive family-centred narrative approach to feeding care might enable pivotal points to be anticipated and resolved. More attention to the diverse values, meanings and emotions around infant feeding within families could help to reconcile health ideals with reality