Casting a wide net: use of diverse model organisms to advance toxicology

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Hahn, M. E., & Sadler, K. C. Casting a wide net: use of diverse model organisms to advance toxicology. Disease Models & Mechanisms, 13, (2020): dmm.043844, doi: 10.1242/dmm.043844.Toxicology – the study of how chemicals interact with biological systems – has clear relevance to human health and disease. Persistent exposure to natural and synthetic chemicals is an unavoidable part of living on our planet; yet, we understand very little about the effects of exposure to the vast majority of chemicals. While epidemiological studies can provide strong statistical inference linking chemical exposure to disease, research in model systems is essential to elucidate the mechanisms of action and to predict outcomes. Most research in toxicology utilizes a handful of mammalian models that represent a few distinct branches of the evolutionary tree. This narrow focus constrains the understanding of chemical-induced disease processes and systems that have evolved in response to exposures. We advocate for casting a wider net in environmental toxicology research to utilize diverse model systems, including zebrafish, and perform more mechanistic studies of cellular responses to chemical exposures to shift the perception of toxicology as an applied science to that of a basic science. This more-inclusive perspective will enrich the field and should remain central to research on chemical-induced disease.K.C.S. acknowledges support from the National Institutes of Health (NIH)(5R01AA018886). M.E.H. acknowledges support from the National Institute ofEnvironmental Health Sciences (NIEHS) through the Boston University SuperfundResearch Program (P42ES007381) and the Woods Hole Center for Oceans andHuman Health (NIEHS grant P01ES028938 and National Science Foundation grantOCE-1840381)

Dicarba-closo-dodecarborane-containing half-sandwich complexes of ruthenium, osmium, rhodium and iridium : biological relevance and synthetic strategies

This review describes how the incorporation of dicarba-closo-dodecarboranes into half-sandwich complexes of ruthenium, osmium, rhodium and iridium might lead to the development of a new class of compounds with applications in medicine. Such a combination not only has unexplored potential in traditional areas such as Boron Neutron Capture Therapy agents, but also as pharmacophores for the targeting of biologically important proteins and the development of targeted drugs. The synthetic pathways used for the syntheses of dicarba-closo-dodecarboranes-containing half-sandwich complexes of ruthenium, osmium, rhodium and iridium are also reviewed. Complexes with a wide variety of geometries and characteristics can be prepared. Examples of addition reactions on the metal centre, B–H activation, transmetalation reactions and/or direct formation of metal–metal bonds are discussed (103 references)

Achieving quality improvement through understanding and evaluating information systems development methodologies

Since the 70s literally hundreds of different methods and tools have appeared each claiming to ease the life of the developer and the user by achieving improved productivity without compromising the quality of the software artefact. These methodologies range from integrated collections of procedures to single technique, notations, 4GLs and tools for supporting the process at the various stages of the systems lifecycle [1, 2, 3, 4]. This paper discusses how an organisation wishing to improve their development practices embarks onto the time-consuming and expensive process of evaluation of methods and tools. The underlying complexity and application domain will themselves be decisive in the choice of methodology. The improvement process starts with the understanding phase. Here, we need to identify the important features of a methodology such as usability, portability, adaptability and functionality, and the nature of the problem(s) the methodology will apply to. We draw the distinction between problem, methodology (procedures, techniques) and tools and discuss their interrelationships [4, 7]. The evaluation phase starts with the specification of acceptance criteria and it involves the study of the features identified during the understanding phase against these criteria. Evaluations can be qualitative and quantitative

A deep survey of the low-surface-brightness radio sky

We have made a radio survey--the Australia Telescope Low Brightness Survey (ATLBS)--of 8.4 square degrees sky area, using the Australia Telescope Compact Array in the 20-cm band, in an observing mode designed to provide wide-field images with exceptional sensitivity in surface brightness, and thereby explore a new parameter space in radio source populations. The goals of this survey are to quantify the distribution in angular sizes, particularly at weak surface brightness levels: this has implications for the confusion in deep surveys with the SKA. The survey is expected to lead to a census of the radio emission associated with low-power radio galaxies at redshifts 1-3, without any missing extended emission, and hence a study of the cosmic evolution of low-power radio galaxies to higher redshift and a comprehensive study of the AGN feedback during the intense black hole growth phase during this redshift range.Comment: 5 pages, includes 2 figures and 1 table. To appear in the proceedings of "From Planets to Dark energy: the modern radio universe" in the online journal Proceedings of Science - Po

ATLBS: the Australia Telescope Low-brightness Survey

We present a radio survey carried out with the Australia Telescope Compact Array. A motivation for the survey was to make a complete inventory of the diffuse emission components as a step towards a study of the cosmic evolution in radio source structure and the contribution from radio-mode feedback on galaxy evolution. The Australia Telescope low-brightness survey (ATLBS) at 1388 MHz covers 8.42 sq deg of the sky in an observing mode designed to yield images with exceptional surface brightness sensitivity and low confusion. The ATLBS radio images, made with 0.08 mJy/beam rms noise and 50" beam, detect a total of 1094 sources with peak flux exceeding 0.4 mJy/beam. The ATLBS source counts were corrected for blending, noise bias, resolution, and primary beam attenuation; the normalized differential source counts are consistent with no upturn down to 0.6 mJy. The percentage integrated polarization Pi_0 was computed after corrections for the polarization bias in integrated polarized intensity; Pi_0 shows an increasing trend with decreasing flux density. Simultaneous visibility measurements made with longer baselines yielded images, with 5" beam, of compact components in sources detected in the survey. The observations provide a measurement of the complexity and diffuse emission associated with mJy and sub-mJy radio sources. 10% of the ATLBS sources have more than half of their flux density in extended emission and the fractional flux in diffuse components does not appear to vary with flux density, although the percentage of sources that have complex structure increases with flux density. The observations are consistent with a transition in the nature of extended radio sources from FR-II radio source morphology, which dominates the mJy population, to FR-I structure at sub-mJy flux density. (Abridged)Comment: 18 pages, 8 figues, 6 tables, accepted for publication in MNRA

At the Back of the North Wind: George MacDonald: A Centennial Appreciation

A brief overview of MacDonald’s life and writing, with a particular focus on At the Back of the North Wind