The effects of peer influence on adolescent pedestrian road-crossing decisions

Objective: Adolescence is a high-risk period for pedestrian injury. It is also a time of heightened susceptibility to peer influence. The aim of this research was to examine the effects of peer influence on the pedestrian road-crossing decisions of adolescents. Methods: Using 10 videos of road-crossing sites, 80 16- to 18-year-olds were asked to make pedestrian road-crossing decisions. Participants were assigned to one of 4 experimental conditions: negative peer (influencing unsafe decisions), positive peer (influencing cautious decisions), silent peer (who observed but did not comment), and no peer (the participant completed the task alone). Peers from the adolescent’s own friendship group were recruited to influence either an unsafe or a cautious decision. Results: Statistically significant differences were found between peer conditions. Participants least often identified safe road-crossing sites when accompanied by a negative peer and more frequently identified dangerous road-crossing sites when accompanied by a positive peer. Both cautious and unsafe comments from a peer influenced adolescent pedestrians’ decisions. Conclusions: These findings showed that road-crossing decisions of adolescents were influenced by both unsafe and cautious comments from their peers. The discussion highlighted the role that peers can play in both increasing and reducing adolescent risk-taking

Clinician and carer moral concerns when caring for children who tube-feed.

Child healthcare can be vexed by moral concerns - this extends to the care of children who tube-feed. Children who tube-feed often receive care from family members and clinicians of various disciplines. Each brings expertise, experiences, values, and views to a situation, prioritising the child's needs while attending to those they deem important in potentially disparate ways. Their understanding of a situation is shaped by beliefs, feelings, and perceptions. How then are key decisions made about the care of a child who tube-feeds? This article explores clinicians' and carers' moral concerns when caring for children who tube-feed. Interviews with clinicians (n = 9) and carers (n = 9) clarified three findings: first, there are often disparate beliefs about the need for tube-feeding; second, tube-feeding can evoke strong emotions; and third, it can be difficult to normalise tube-feeding. This article demonstrates how challenges can emerge when relationships between clinicians and carers diverge. Furthermore, it establishes how an ethic of care can bring different interests together to bolster the relationships required to optimise feeding care and promote health outcomes among children who tube-feed and their carers. This requires improved dialogue between and among clinicians and carers to create shared understandings of what is, what should be, and how to benefit children who tube-feed

Quantum Phase Transitions in the Ising model in spatially modulated field

The phase transitions in the transverse field Ising model in a competing spatially modulated (periodic and oscillatory) longitudinal field are studied numerically. There is a multiphase point in absence of the transverse field where the degeneracy for a longitudinal field of wavelength $\lambda$ is $(\frac {1 + \sqrt{5}}{2})^{2N/\lambda}$ for a system with $N$ spins, an exact result obtained from the known result for $\lambda =2$. The phase transitions in the $\Gamma$ (transverse field) versus $h_0$ (amplitude of the longitudinal field) phase diagram are obtained from the vanishing of the mass gap $\Delta$. We find that for all the phase transition points obtained in this way, $\Delta$ shows finite size scaling behaviour signifying a continuous phase transition everywhere. The values of the critical exponents show that the model belongs to the universality class of the two dimensional Ising model. The longitudinal field is found to have the same scaling behaviour as that of the transverse field, which seems to be a unique feature for the competing field. The phase boundaries for two different wavelengths of the modulated field are obtained. Close to the multiphase point at $h_c$, the phase boundary behaves as $(h_c - h_0)^b$, where $b$ is also $\lambda$ dependent.Comment: To appear in Physical Review

Peritoneal dialysis technique survival at Tygerberg Hospital in Cape Town, South Africa

Background: The use of peritoneal dialysis (PD) as a treatment modality for patients with end-stage renal disease (ESRD) has been declining in many countries over the past few years. One of the reasons is technique failure, which occurs more frequently than is the case with chronic haemodialysis. Identifying and addressing the causes of technique failure is important in order to maintain more patients on PD, especially in settings where there are limited resources for chronic haemodialysis and a “PD first” approach is followed.Methods: In this retrospective study at Tygerberg Hospital in Cape Town, South Africa, we investigated 170 patients who were started on chronic ambulatory PD between January 2008 and July 2014, and determined rates of technique and patient survival. Demographic, clinical and laboratory data were assessed to identify risk factors for these outcomes.Results: The median age of the patients was 36 years and the most common cause of ESRD was glomerulonephritis. Only one patient had diabetes mellitus. Technique survival at 1, 3 and 5 years was 80%, 54% and 39%, respectively, while patient survival was 90%, 82% and 63%. Patients started on PD during the second half of the study period had improved rates of technique survival. Peritonitis was the most common cause of technique failure. Increasing age and Black ethnicity were associated with increased likelihood of technique failure. Other clinical and social factors were not significantly associated with the occurrence of technique failure.Conclusions: In our patients on PD, peritonitis, increased age and Black ethnicity were important factors associated with the development of technique failure. Concerted efforts are required to reduce peritonitis rates at our centre as this is the leading cause of technique failure

Local cues and asymmetric cell divisions underpin body plan transitions in the moss Physcomitrella patens

Background: Land plants evolved from aquatic algae more than 450 million years ago. Algal sisters of land plants grow through the activity of apical initial cells that cleave either in one plane to generate filaments or in two planes to generate mats. Acquisition of the capacity for cell cleavage in three planes facilitated the formation of upright bushy body plans and enabled the invasion of land. Evolutionary transitions between filamentous, planar, and bushy growth are mimicked within moss life cycles. Results: We have developed lineage analysis techniques to assess how transitions between growth forms occur in the moss Physcomitrella patens. We show that initial cells giving rise either to new filaments or bushy shoots are frequently juxtaposed on a single parent filament, suggesting a role for short-range cues in specifying differences in cell fate. Shoot initials cleave four times to establish a tetrahedral shape and subsequently cleave in three planes, generating bushy growth. Asymmetric and self-replacing divisions from the tetrahedral initial generate leaf initials that divide asymmetrically to self-replace and to produce daughter cells with restricted fate. The cessation of division in the leaf is distributed unevenly and contributes to final leaf shape. Conclusions: In contrast to flowering plants, changes in body plan in P. patens are regulated by cues acting at the level of single cells and are mediated through asymmetric divisions. Genetic mechanisms regulating shoot and leaf development in P. patens are therefore likely to differ substantially from mechanisms operating in plants with more recent evolutionary origins

Modelling the influence of RKIP on the ERK signalling pathway using the stochastic process algebra PEPA

This paper examines the influence of the Raf Kinase Inhibitor Protein (RKIP) on the Extracellular signal Regulated Kinase (ERK) signalling pathway [5] through modelling in a Markovian process algebra, PEPA [11]. Two models of the system are presented, a reagent-centric view and a pathway-centric view. The models capture functionality at the level of subpathway, rather than at a molecular level. Each model affords a different perspective of the pathway and analysis. We demonstrate the two models to be formally equivalent using the timing-aware bisimulation defined over PEPA models and discuss the biological significance

Radio Continuum and Recombination Line Study of UC HII Regions with Extended Envelopes

We have carried out 21 cm radio continuum observations of 16 UC HII regions using the VLA (D-array) in search of associated extended emission. We have also observed H76$_\alpha$ recombination line towards all the sources and He76$_\alpha$ line at the positions with strong H76$_\alpha$ line emission. The UC HII regions have simple morphologies and large (>10) ratios of single-dish to VLA fluxes. Extended emission was detected towards all the sources. The extended emission consists of one to several compact components and a diffuse extended envelope. All the UC HII regions but two are located in the compact components, where the UC HII regions always correspond to their peaks. The compact components with UC HII regions are usually smaller and denser than those without UC HII regions. Our recombination line observations indicate that the ultracompact, compact, and extended components are physically associated. The UC HII regions and their associated compact components are likely to be ionized by the same sources on the basis of the morphological relations mentioned above. This suggests that almost all of the observed UC HII regions are not `real' UC HII regions and that their actual ages are much greater than their dynamical age (<10000 yr). We find that most of simple UC HII regions previously known have large ratios of single-dish to VLA fluxes, similar to our sources. Therefore, the `age problem' of UC HII regions does not seem to be as serious as earlier studies argued. We present a simple model that explains extended emission around UC HII regions. Some individual sources are discussed.Comment: 29 pages, 28 postscript figures, Accepted for publication in Ap

How is Brilliance Enacted in Professional Practices? Insights from the Theory of Practice Architectures

Brilliance has been overlooked in studies of professional work. This study aimed to understand how brilliant practices are made possible and enacted in a multidisciplinary paediatric feeding clinic, where professionals from different disciplines work together and with parents and carers of children. The existing literature has thematically described brilliance but not theorised how it is accomplished and enabled. Using video reflexive ethnographic methods, the study involved the video-recording of 17 appointments and two reflexive discussions with the participating professionals, who selected and reviewed five episodes exemplifying brilliant care. These were analysed through three themes: carer-friendly and carer-oriented practice; ways of working together; and problem-solving in actu (in the very act of doing). Using the theory of practice architectures, we explored brilliant practices as complexes of sayings, doings, and relatings, identifying the arrangements that enabled those practices and the forms of praxis involved