High-resolution simulations of stellar collisions between equal-mass main-sequence stars in globular clusters

We performed high-resolution simulations of two stellar collisions relevant for stars in globular clusters. We considered one head-on collision and one off-axis collision between two 0.6 M_sun main sequence stars. We show that a resolution of about 100 000 particles is sufficient for most studies of the structure and evolution of blue stragglers. We demonstrate conclusively that collision products between main-sequence stars in globular clusters do not have surface convection zones larger than 0.004 M_sun after the collision, nor do they develop convection zones during the `pre-main-sequence' thermal relaxation phase of their post-collision evolution. Therefore, any mechanism which requires a surface convection zone (i.e. chemical mixing or angular momentum loss via a magnetic wind) cannot operate in these stars. We show that no disk of material surrounding the collision product is produced in off-axis collisions. The lack of both a convection zone and a disk proves a continuing problem for the angular momentum evolution of blue stragglers in globular clusters.Comment: 7 pages, 5 figures, accepted by MNRA

Qualitative Data Analysis Challenges in Co-Designing Educational Technology Systems for Refugee Children

There is a growing interest in the potential for technology to facilitate emergency education of refugee children. But designing in this space requires knowledge of the displaced population and the contextual dynamics surrounding it. Design should therefore be informed by both existing research across relevant disciplines, and from those who are on the ground facing the problem in real life. This paper describes a process that is based on literature from emergency education, student engagement and motivation, educational technology, and participatory design. We describe how this process was implemented leading to the design of a digital learning space for children living in a refugee camp in Greece. The challenge of data analysis is critical, as the qualitative data in the process is elicited from activities of various natures and thus moving from qualitative data to designs is a critical challenge that we are looking to cover for our process to be complete and applicable. We discuss some of the challenges that can be expected in such context

Labor Law Preemption: The Ninth Circuit Grants Malpractice Immunity to Union Attorneys—Peterson v. Kennedy, 771 F.2d 1244 (9th Cir. 1985)

This Note traces the development of federal preemption in labor law, examining Peterson as an illustration of the tendency of courts to broadly interpret federal statutory labor policy. In particular, this Note questions whether preemption in a legal malpractice action is appropriate, since professional negligence is not expressly or impliedly addressed under federal statute, and is not an essential part of the national labor policy expressed in legislative history. This Note concludes that federal law should not have preempted the state cause of action in Peterson. Finally, this Note suggests that recognition of state legal malpractice actions would be an ideal signpost announcing the outer limits of federal preemption under Section 301

Brown dwarf populations in open clusters

We present the results of multiple simulations of open clusters, modelling the dynamics of a population of brown dwarf members. We consider the effects of a large range of primordial binary populations, including the possibilities of having brown dwarf members contained within a binary system. We also examine the effects of various cluster diameters and masses. Our examination of a population of wide binary systems containing brown dwarfs, reveals evidence for exchange reactions whereby the brown dwarf is ejected from the system and replaced by a heavier main-sequence star. We find that there exists the possibility of hiding a large fraction of the brown dwarfs contained within the primordial binary population. We conclude that it is probable that the majority of brown dwarfs are contained within primordial binary systems which then hides a large proportion of them from detection.Comment: 16 pages, 8 figures; to appear in MNRA

Restricted Crossings on Rural Highways

This study examines the potential for replacing the standard intersection design at two-way stop control (TWSC) and all- way stop control (AWSC) intersections along rural highways with a roundabout or a restricted crossing u-turn (RCUT) facility. The geometry of the RCUT design prohibits left and through movements from the side road, and provides a u-turn location downstream from the main crossing. This type of facility has been implemented for rural highways extensively in both Maryland and North Carolina, as well as in limited cases in many other states such as Minnesota and Missouri, with the potential to serve as a cost-effective solution to improve roadway safety within Nebraska. The primary takeaway from the research is that both a roundabout and an RCUT design can be relied upon to lead to significant safety improvements for unsignalized intersections on rural highways, and that the decision of which one to use should factor in the potential increase in delays to the minor approach at the RCUT design if a high demand volume is anticipated (such as Dakota City), or the consideration of whether it is permissible to interrupt the flow of the major arterial through movement with a roundabout versus leaving it free-flowing with the RCUT

Increasing participation in the information society by people with disabilities and their families in lower-income countries using mainstream technologies

Assistive technology (AT) has been actively researched, developed and implemented throughout higher-income countries, but is relatively absent from lower-income countries. In lower-income countries, there is very little AT for reading, writing, communicating and for participation in the information society. In order for persons with disabilities in lower-income countries to participate fully in society, mainstream information and communication technologies (ICTs) such as mobile phones should be used as AT. This paper explores the potential for using mainstream ICTs as AT in lower-income countries, keeping in mind current ICT trends, characteristics of the post-PC era and ICT-based AT in higher-income countries. The paper concludes with a case study where mobile phones and SMS were used by people with disabilities and their caregivers to access information in a resourced-limited community in Bogota, Colombia. Mobile phones, a readily available mainstream ICT in this community, were a useful tool for addressing the information exclusion of people with disabilities and caregivers

Advances in conservation science and practice in Oceania: delivering on research priorities for the region

[Extract] Oceania is a diverse region both biologically and culturally. Yet the region is also marked by high rates of biodiversity loss due to major threats such as habitat destruction, climate change and invasive species (Kingsford et al., 2009). Evidence-based strategies are needed for successful conservation in the region, and targeted research delivering on urgent practical questions can support this. In 2015, we set out to identify research questions that, if answered, would increase the effectiveness of conservation and natural resource management practice and policy within Oceania in the next 10 years (Weeks & Adams, 2017). The priority questions that we identified emphasized the need for research that addresses distinctive management challenges prevalent in Oceania, and which fits the sociocultural contexts of the region. Five years on, we reflect on some of the progress made in answering these priority questions, with the eight papers featured in this Special Section addressing 12 of the 38 priority questions (Table 1)

Enabling live dialogic and collaborative learning between field and indoor contexts

This paper explores how field and indoor based students can be connected so that their contrasting circumstances and capabilities are used as a basis for learning. We describe the design of the ‘Out There and In Here’ system and activity. Using naturalistic evaluations in the context of higher education earth science, we find evidence that this approach can be beneficial in developing essential skills, by supporting dialogue and collaboration across diverse contexts. This provokes novel forms of reflection and motivation, and could inspire a new generation of learning tools combining mobile and collaborative technologies. We discuss important issues in this design space, such as asymmetrical dependencies and structures for dialogic and collaborative learning