A Survey of Proper Motion Stars. XVII. A Deficiency of Binary Stars on Retrograde Galactic Orbits and the Possibility that omega Centauri is Related to the Effect

We find a deficiency of binary stars moving on strongly retrograde Galactic orbits. No binary deficiencies are seen for U or W velocities, however. From theoretical analyses, we rule out preferential disruption of pre-existing binary stars due to encounters with massive perturbers. We also rule out globular clusters as the source of the effect since prograde motions are more likely to create such an effect. We search for star streams and find one possible candidate, but it is not on a retrograde orbit and probably represents the remains of a cluster that has passed too near the Galactic center. Based on a very small number of stars, we find that about the right fraction of stars on retrograde Galactic orbits share some chemical similarities to the cluster omega Cen, suggesting that its parent galaxy could be the explanation.Comment: To appear in the Astronomical Journal (March 2005 issue

Step by step optimization of a sperm cryopreservation protocol for spotted wolffish (Anarhichas minor Olafsen, 1772)

Spotted wolffish Anarhichas minor reproduction in captivity is dependent on in vitro fertilization. However, low sperm volume with relatively low cell concentration and the lack of gametes synchronization (simultaneous availability of mature eggs and sperm) represent a challenge for the industry. Thus, the development of protocols for sperm storage are crucial. Four sequential experiments were conducted to optimize a sperm cryopreservation protocol for this species. First, three different cryoprotectants (DMSO; 1, 2-propanediol; and methanol) at different concentrations (5, 10, and 20%) were tested for their toxicity. No significant differences (p > 0.05) were detected between the control samples and cryoprotectants at concentration up to 10% DMSO, 10% propanediol, and 20% methanol in terms of motility parameters. Second, using the highest non-toxic concentrations of cryoprotectants, sperm was cryopreserved in 0.5 mL straws, at different distances from the liquid nitrogen (1.5, 2.5, 4.5, and 7.5 cm) that correspond to different freezing rates. Motility parameters after freezing/thawing decreased for all the cryoprotectants (p  0.05) between the two thawing rates. The best results were obtained using 10% DMSO. Finally, the fertilization capacity of cryopreserved sperm (10% DMSO and thawed at 5 °C for 1 min) was tested against fresh sperm using two spermatozoa:egg ratios and 4 h gametes contact time. The ratio of eggs with normal cell cleavage, abnormal cleavage or undeveloped were counted at the 2-4 cell stage. Cryopreserved sperm showed lower fertilization capacity at a concentration of 5 × 104 spermatozoa:egg compared with fresh sperm (p  0.05). To cryopreserve spotted wolffish sperm it is recommended to use 10% DMSO, loaded in 0.5 mL straws, freeze at a height between 4.5 (-14.05 °C/min) and 7.5 cm (-5.9 °C/min) from liquid nitrogen for 10 min and thaw for 1 min at 5 °C (177.9 °C/min). In vitro fertilization with cryopreserved sperm should be performed with a concentration of at least 5 × 105 spermatozoa per egg.WOLFSTORE project (AF0078) supported by the MABIT program from Norway. JS was supported by a Cost action FA1205 AQUAGAMETE and an ERASMUS grant.info:eu-repo/semantics/publishedVersio

On the age heterogeneity of the Pleiades, Hyades and Sirius moving groups

We investigate the nature of the classical low-velocity structures in the local velocity field, i.e. the Pleiades, Hyades and Sirius moving groups. After using a wavelet transform to locate them in velocity space, we study their relation with the open clusters kinematically associated with them. By directly comparing the location of moving group stars in parallax space to the isochrones of the embedded clusters, we check whether, within the observational errors on the parallax, all moving group stars could originate from the on-going evaporation of the associated cluster. We conclude that, in each moving group, the fraction of stars making up the velocity-space overdensity superimposed on the background is higher than the fraction of stars compatible with the isochrone of the associated cluster. These observations thus favour a dynamical (resonant) origin for the Pleiades, Hyades and Sirius moving groups.Comment: 8 pages, 8 figures, accepted for publication in A&

The cue is key: Design for real-life remembering

This paper aims to put the memory cue in the spotlight. We show how memory cues are incorporated in the area of interaction design. The focus is on external memory cues - cues that exist outside the human mind but have an internal effect on memory reconstruction. Examples of external cues include people, environments, and things, where the latter are most relevant for the aim of this paper since these cues can be incorporated in designs. This paper makes a dual contribution to research: (1) it provides insights into how memory research informs the design of devices to facilitate personal memory recall; and (2) by taking a design perspective, it raises questions about memory cues as part of real-life remembering to inform psychological memory research. Since memory theory inspires design and both fields would benefit from collaboration, we would like these questions to be an inspiration for future memory research, in particular targeting external memory cues. © 2014 Hogrefe Publishing

Climate change effects on human health: projections of temperature-related mortality for the UK during the 2020s, 2050s and 2080s

Background The most direct way in which climate change is expected to affect public health relates to changes in mortality rates associated with exposure to ambient temperature. Many countries worldwide experience annual heat-related and cold-related deaths associated with current weather patterns. Future changes in climate may alter such risks. Estimates of the likely future health impacts of such changes are needed to inform public health policy on climate change in the UK and elsewhere. Methods Time-series regression analysis was used to characterise current temperature-mortality relationships by region and age group. These were then applied to the local climate and population projections to estimate temperature-related deaths for the UK by the 2020s, 2050s and 2080s. Greater variability in future temperatures as well as changes in mean levels was modelled. Results A significantly raised risk of heat-related and cold-related mortality was observed in all regions. The elderly were most at risk. In the absence of any adaptation of the population, heat-related deaths would be expected to rise by around 257% by the 2050s from a current annual baseline of around 2000 deaths, and cold-related mortality would decline by 2% from a baseline of around 41 000 deaths. The cold burden remained higher than the heat burden in all periods. The increased number of future temperature-related deaths was partly driven by projected population growth and ageing. Conclusions Health protection from hot weather will become increasingly necessary, and measures to reduce cold impacts will also remain important in the UK. The demographic changes expected this century mean that the health protection of the elderly will be vital

Informing design for reflection: An overview of current everyday practices

© 2016 ACM. There is an increasing interest in HCI in designing to support reflection in users. In this paper, we specifically focus on everyday life reflection, covering and connecting a broad range of topics from someone's life rather than focusing on a very specific aspect. Although many systems aim to support reflection, few are based on an overview of how people currently integrate reflection in everyday life. In this paper, we aim to contribute to this gap through a questionnaire on everyday life reflection practices combining both qualitative and quantitative questions. Findings provide insights in the broad range of people that engage with reflection in different ways. We aim to inform design through four considerations: rumination, timing, initiative and social context

Peripheral interaction: characteristics and considerations

© 2014, Springer-Verlag London. In everyday life, we are able to perceive information and perform physical actions in the background or periphery of attention. Inspired by this observation, several researchers have studied interactive systems that display digital information in the periphery of attention. To broaden the scope of this research direction, a few recent studies have focused on interactive systems that can not only be perceived in the background but also enable users to physically interact with digital information in their periphery. Such peripheral interaction designs can support computing technology to fluently embed in and become a meaningful part of people’s everyday routines. With the increasing ubiquity of technology in our everyday environment, we believe that this direction is highly relevant nowadays. This paper presents an in-depth analysis of three case studies on peripheral interaction. These case studies involved the design and development of peripheral interactive systems and deployment of these systems in the real context of use for a number of weeks. Based on the insights gained through these case studies, we discuss generalized characteristics and considerations for peripheral interaction design and evaluation. The aim of the work presented in this paper is to support interaction design researchers and practitioners in anticipating and facilitating peripheral interaction with the designs they are evaluating or developing

The Hierarchical Formation of the Galactic Disk

I review the results of recent cosmological simulations of galaxy formation that highlight the importance of satellite accretion in the formation of galactic disks. Tidal debris of disrupted satellites may contribute to the disk component if they are compact enough to survive the decay and circularization of the orbit as dynamical friction brings the satellite into the disk plane. This process may add a small but non-negligible fraction of stars to the thin and thick disks, and reconcile the presence of very old stars with the protracted merging history expected in a hierarchically clustering universe. I discuss various lines of evidence which suggest that this process may have been important during the formation of the Galactic disk.Comment: paper to be read at the "Penetrating Bars through Masks of Cosmic Dust" conference in South Afric

Designing for multi-user interaction in the home environment: Implementing social translucence

© 2016 ACM. Interfaces of interactive systems for domestic use are usually designed for individual interactions although these interactions influence multiple users. In order to prevent conflicts and unforeseen influences on others we propose to leverage the human ability to take each other into consideration in the interaction. A promising approach for this is found in the social translucence framework, which was originally described by Erickson & Kellogg. In this paper, we investigate how to design multi-user interfaces for domestic interactive systems through two design cases where we focus on the implementation of social translucence constructs (visibility, awareness, and accountability) in the interaction. We use the resulting designs to extract design considerations: interfaces should not prescribe behavior, need to offer sufficient interaction alternatives, and previous settings need to be retrievable. We also identify four steps that can be integrated in any design process to help designers in creating interfaces that support multi-user interaction through social translucence