Effects of cluster galaxies on arc statistics

We present the results of a set of numerical simulations evaluating the effect of cluster galaxies on arc statistics. We perform a first set of gravitational lensing simulations using three independent projections for each of nine different galaxy clusters obtained from N-body simulations. The simulated clusters consist of dark matter only. We add a population of galaxies to each cluster, mimicking the observed luminosity function and the spatial galaxy distribution, and repeat the lensing simulations including the effects of cluster galaxies, which themselves act as individual lenses. Each galaxy is represented by a spherical Navarro, Frenk & White (1997) density profile. We consider the statistical distributions of the properties of the gravitational arcs produced by our clusters with and without galaxies. We find that the cluster galaxies do not introduce perturbations strong enough to significantly change the number of arcs and the distributions of lengths, widths, curvature radii and length-to-width ratios of long arcs. We find some changes to the distribution of short-arc properties in presence of cluster galaxies. The differences appear in the distribution of curvature radii for arc lengths smaller than 12'', while the distributions of lengths, widths and length-to-width ratios are significantly changed only for arcs shorter than 4''.Comment: 11 pages, Latex using MN style, 6 figures enclosed. Version accepted for publication in MNRAS. Gzipped file including a full resolution version of Figures 2a, 2b, 3a, 3b, 3c can be downloaded by anonymous ftp at http://gt.pd.astro.it/~bepi/PAPERS/lensing.ps.g

Magnetic Field and Pressure Phase Diagrams of Uranium Heavy-Fermion Compound U2_2Zn17_{17}

We have performed magnetization measurements at high magnetic fields of up to 53 T on single crystals of a uranium heavy-fermion compound U$_2$Zn$_{17}$ grown by the Bridgman method. In the antiferromagnetic state below the N\'{e}el temperature $T_{\rm N}$ = 9.7 K, a metamagnetic transition is found at $H_c$ $\simeq$ 32 T for the field along the [11$\bar{2}$0] direction ($a$-axis). The magnetic phase diagram for the field along the [11$\bar{2}$0] direction is given. The magnetization curve shows a nonlinear increase at $H_m$ $\simeq$ 35 T in the paramagnetic state above $T_{\rm N}$ up to a characteristic temperature $T_{{\chi}{\rm max}}$ where the magnetic susceptibility or electrical resistivity shows a maximum value. This metamagnetic behavior of the magnetization at $H_m$ is discussed in comparison with the metamagnetic magnetism of the heavy-fermion superconductors UPt$_3$, URu$_2$Si$_2$, and UPd$_2$Al$_3$. We have also carried out high-pressure resistivity measurement on U$_2$Zn$_{17}$ using a diamond anvil cell up to 8.7 GPa. Noble gas argon was used as a pressure-transmitting medium to ensure a good hydrostatic environment. The N\'{e}el temperature $T_{\rm N}$ is almost pressure-independent up to 4.7 GPa and starts to increase in the higher-pressure region. The pressure dependences of the coefficient of the $T^2$ term in the electrical resistivity $A$, the antiferromagnetic gap $\Delta$, and the characteristic temperature $T_{{\rho}{\rm max}}$ are discussed. It is found that the effect of pressure on the electronic states in U$_2$Zn$_{17}$ is weak compared with those in the other heavy fermion compounds

High-pressure phases of uranium monophosphide studied by synchrotron x-ray diffraction

X-ray diffraction studies have been performed on UP powder for pressures up to 51 GPa using synchrotron radiation and a diamond-anvil cell. At ambient pressure UP has the rocksalt structure. The bulk modulus has been determined to B$_0$=102(4) GPa and its pressure derivative to B'$_0$ =4.0(8). The cubic phase has been found to transform to a new phase, UP II, at about 10 GPa. UP II can be characterized by a rhombohedral Bravais lattice. UP II transforms to an orthorhombic phase, UP III, at 28 GPa. No volume change has been observed at the two transitions. The influence of the 5f electrons on the transformations is discussed

The Open Innovation in Science research field: a collaborative conceptualisation approach

Openness and collaboration in scientific research are attracting increasing attention from scholars and practitioners alike. However, a common understanding of these phenomena is hindered by disciplinary boundaries and disconnected research streams. We link dispersed knowledge on Open Innovation, Open Science, and related concepts such as Responsible Research and Innovation by proposing a unifying Open Innovation in Science (OIS) Research Framework. This framework captures the antecedents, contingencies, and consequences of open and collaborative practices along the entire process of generating and disseminating scientific insights and translating them into innovation. Moreover, it elucidates individual-, team-, organisation-, field-, and society‐level factors shaping OIS practices. To conceptualise the framework, we employed a collaborative approach involving 47 scholars from multiple disciplines, highlighting both tensions and commonalities between existing approaches. The OIS Research Framework thus serves as a basis for future research, informs policy discussions, and provides guidance to scientists and practitioners

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Narcissism: a factor behind the selective sharing of news online

The current study examined the extent to which narcissism influences the social network users’ intention to share positive and negative life events with (close or unknown) online contacts. Using an online survey, small vignettes and a cross-sectional convenience sample of 119 participants, the results showed that narcissism positively predicted sharing intention of positive and negative life events with strangers. However, individuals rating higher in narcissism were less likely to share negative news with family. The research findings suggest that personality traits such as narcissism, the type of contacts online, and the nature of the news may shape what information is shared by online users. The type of news presented may therefore be a function of who is posting the content, their personality, and the kind of social network contacts they have online

Microfluidics: reframing biological enquiry

The underlying physical properties of microfluidic tools have led to new biological insights through the development of microsystems that can manipulate, mimic and measure biology at a resolution that has not been possible with macroscale tools. Microsystems readily handle sub-microlitre volumes, precisely route predictable laminar fluid flows and match both perturbations and measurements to the length scales and timescales of biological systems. The advent of fabrication techniques that do not require highly specialized engineering facilities is fuelling the broad dissemination of microfluidic systems and their adaptation to specific biological questions. We describe how our understanding of molecular and cell biology is being and will continue to be advanced by precision microfluidic approaches and posit that microfluidic tools - in conjunction with advanced imaging, bioinformatics and molecular biology approaches - will transform biology into a precision science