Microarray analysis of whole genome expression of intracellular Mycobacterium tuberculosis

Analysis of the changing mRNA expression profile of Mycobacterium tuberculosis though the course of infection promises to advance our understanding of how mycobacteria are able to survive the host immune response. The difficulties of sample extraction from distinct mycobacterial populations, and of measuring mRNA expression profiles of multiple genes has limited the impact of gene expression studies on our interpretation of this dynamic infection process. The development of whole genome microarray technology together with advances in sample collection have allowed the expression pattern of the whole M. tuberculosis genome to be compared across a number of different in vitro conditions, murine and human tissue culture models and in vivo infection samples. This review attempts to produce a summative model of the M. tuberculosis response to infection derived from or reflected in these gene expression datasets. The mycobacterial response to the intracellular environment is characterised by the utilisation of lipids as a carbon source and the switch from aerobic/microaerophilic to anaerobic respiratory pathways. Other genes induced in the macrophage phagosome include those likely to be involved in the maintenance of the cell wall and genes related to DNA damage, heat shock, iron sequestration and nutrient limitation. The comparison of transcriptional data from in vitro models of infection with complex in vivo samples, together with the use of bacterial RNA amplification strategies to sample defined populations of bacilli, should allow us to make conclusions about M. tuberculosis physiology and host microenvironments during natural infection

The frequency and properties of young tidal dwarf galaxies in nearby gas-rich groups

We present high-resolution Giant Metrewave Radio Telescope (GMRT) HI observations and deep Canada-France-Hawaii Telescope (CFHT) optical imaging of two galaxy groups: NGC 4725/47 and NGC 3166/9. These data are part of a multi-wavelength unbiased survey of the gas-rich dwarf galaxy populations in three nearby interacting galaxy groups. The NGC 4725/47 group hosts two tidal knots and one dIrr. Both tidal knots are located within a prominent HI tidal tail, appear to have sufficient mass (M_gas~10^8 M_sol) to evolve into long-lived tidal dwarf galaxies (TDGs) and are fairly young in age. The NGC 3166/9 group contains a TDG candidate, AGC 208457, at least three dIrrs and four HI knots. Deep CFHT imaging confirms that the optical component of AGC 208457 is bluer -- with a 0.28 mag g-r colour -- and a few Gyr younger than its purported parent galaxies. Combining the results for these groups with those from the NGC 871/6/7 group reported earlier, we find that the HI properties, estimated stellar ages and baryonic content of the gas-rich dwarfs clearly distinguish tidal features from their classical counterparts. We optimistically identify four potentially long-lived tidal objects associated to three separate pairs of interacting galaxies, implying that TDGs are not readily produced during interaction events as suggested by some recent simulations. The tidal objects examined in this survey also appear to have a wider variety of properties than TDGs of similar mass formed in current simulations of interacting galaxies, which could be the result of pre- or post-formation environmental influences.Comment: 18 pages, 14 figures, accepted for publication in MNRA

Meteoritic Material Recovered from the 07 March 2018 Meteorite Fall into the Olympic Coast National Marine Sanctuary

On 07 March 2018 at 20:05 local time (08 March 03:05 UTC), a dramatic meteor occurred over Olympic Coast National Marine Sanctuary (OCNMS) off of the Washington state coast (OCNMS fall, henceforth). Data to include seismometry (from both on-shore and submarine seismometers), weather radar imagery (Figure 1), and a moored weather buoy, were used to accurately identify the fall site. The site was visited by the exploration vessel E/V Nautilus (Ocean Exploration Trust) on 01 July 2018 [1] and by the research vessel R/V Falkor (Schmidt Ocean Institute) from 03-06 June 2019. Remotely operated vehicles (ROVs) from both vessels were used to search for meteorites and sample seafloor sediments. These expeditions performed the first attempts to recover meteorites from a specific observed fall in the open ocean. Analysis of weather radar data indicates that this fall was unusually massive and featured meteorites of unusually high mechanical toughness, such that large meteorites were disproportionately produced compared to other meteorite falls (Figure 2)[2-4]. We report the recovery of many (>100) micrometeorite-sized melt spherules and other fragments, and one small (~1mm3 ) unmelted meteorite fragment identified to date. Approximately 80% of the fragments were recovered from a single sample, collected from a round pit in the seafloor sediment. Melt spherules are almost exclusively type I iron-rich spherules with little discernible oxidation. Analyses are currently underway to attempt to answer the primary science question by identifying the parent meteorite type. Also, differences in the number and nature of samples collected by Nautilus and Falkor reveal a distinct loss rate to oxidation over the 15 months following the fall that is useful to inform future recovery efforts

Pre-existing dwarfs, tidal knots and a tidal dwarf galaxy: an unbiased H_I study of the gas-rich interacting galaxy group NGC 3166/9

We present Arecibo Legacy Fast ALFA (ALFALFA) and follow-up Giant Metrewave Radio Telescope (GMRT) H _I observations of the gas-rich interacting group NGC 3166/9. The sensitive ALFALFA data provide a complete census of H _I-bearing systems in the group while the high-resolution GMRT data elucidate their origin, enabling one of the first unbiased physical studies of gas-rich dwarf companions and the subsequent identification of second-generation, tidal dwarf galaxies in a nearby group. The ALFALFA maps reveal an extended H _I envelope around the NGC 3166/9 group core, which we mosaic at higher resolution using six GMRT pointings spanning ∼1 deg^2. A thorough search of the GMRT data cube reveals eight low-mass objects with gas masses ranging from 4 × 10^7 to 3 × 10^8 M_⊙ and total dynamical masses up to 1.4 × 10^9 M_⊙. A comparison of the H I fluxes measured from the GMRT data to those measured in the ALFALFA data suggests that a significant fraction (∼60 per cent) of the H _I is smoothly distributed on scales greater than 1 arcmin (∼7 kpc at the NGC 3166/9 distance). We compute stellar masses and star formation rates for the eight low-mass GMRT detections, using ancillary Sloan Digital Sky Survey (SDSS) and Galaxy Evolution Explorer (GALEX) data, and use these values to constrain their origin. Most of the detections are likely to be either pre-existing dwarf irregular galaxies or short-lived, tidally formed knots; however, one candidate, AGC 208457, is clearly associated with a tidal tail extending below NGC 3166, exhibits a dynamical to gas mass ratio close to unity and has a stellar content and star formation rate that are broadly consistent with both simulated as well as candidate tidal dwarf galaxies from the literature. Our observations therefore strongly suggest that AGC 208457 is a tidal dwarf galaxy

The influence of 'significant others' on persistent back pain and work participation: a qualitative exploration of illness perceptions

Background Individual illness perceptions have been highlighted as important influences on clinical outcomes for back pain. However, the illness perceptions of 'significant others' (spouse/partner/close family member) are rarely explored, particularly in relation to persistent back pain and work participation. The aim of this study was to initiate qualitative research in this area in order to further understand these wider influences on outcome. Methods Semi-structured interviews based on the chronic pain version of the Illness Perceptions Questionnaire-Revised were conducted with a convenience sample of UK disability benefit claimants, along with their significant others (n=5 dyads). Data were analysed using template analysis. Results Significant others shared, and perhaps further reinforced, claimants' unhelpful illness beliefs including fear of pain/re-injury associated with certain types of work and activity, and pessimism about the likelihood of return to work. In some cases, significant others appeared more resigned to the permanence and negative inevitable consequences of the claimant's back pain condition on work participation, and were more sceptical about the availability of suitable work and sympathy from employers. In their pursuit of authenticity, claimants were keen to stress their desire to work whilst emphasising how the severity and physical limitations of their condition prevented them from doing so. In this vein, and seemingly based on their perceptions of what makes a 'good' significant other, significant others acted as a 'witness to pain', supporting claimants' self-limiting behaviour and statements of incapacity, often responding with empathy and assistance. The beliefs and responses of significant others may also have been influenced by their own experience of chronic illness, thus participants lives were often intertwined and defined by illness. Conclusions The findings from this exploratory study reveal how others and wider social circumstances might contribute both to the propensity of persistent back pain and to its consequences. This is an area that has received little attention to date, and wider support of these findings may usefully inform the design of future intervention programmes aimed at restoring work participation

Optical spectroscopy of young tidal objects around two interacting galaxy pairs

We present Gemini Multi-Object Spectrograph spectra of HI-rich tidal features located around the outskirts of two interacting galaxy pairs, NGC 3166/9 and NGC 4725/47. These follow-up observations are part of a multiwavelength campaign to study the properties and frequency of tidal dwarf galaxies (TDGs) in group environments. Based on the calculated gas-phase metallicity and redshift, in addition to the previously measured HI and stellar properties, we have confirmed the tidal origins of TDG candidate AGC 208457, which has emerged from the tidal debris of an interaction between the NGC 3166/9 galaxy pair. By comparing HI and optical recessional velocities, we have also confirmed a physical association of the gaseous knots and star clusters embedded in the metal-rich tidal tail of NGC 4747.Fil: Lee-Waddell, K.. CIRO Australia Telescope National Facility; AustraliaFil: Madrid, J. P.. CIRO Australia Telescope National Facility; AustraliaFil: Spekkens, K. Royal Military College of Canada; CanadáFil: Donzelli, Carlos Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Koribalski, B. S.. CIRO Australia Telescope National Facility; AustraliaFil: Serra, P.. Università Degli Studi Di Cagliari.; ItaliaFil: Cannon, J. Macalester College. Department of Physics and Astronomy; Estados Unido

Coordinated and tailored work rehabilitation: a randomized controlled trial with economic evaluation undertaken with workers on sick leave due to musculoskeletal disorders

Introduction In Denmark, the magnitude and impact of work disability on the individual worker and society has prompted the development of a new "coordinated and tailored work rehabilitation" (CTWR) approach. The aim of this study was to compare the effects of CTWR with conventional case management (CCM) on return-to-work of workers on sick leave due to musculoskeletal disorders (MSDs). Methods The study was a randomized controlled trial with economic evaluation undertaken with workers on sick leave for 4-12 weeks due to MSDs. CTWR consists of a work disability screening by an interdisciplinary team followed by the collaborative development of a RTW plan. The primary outcome variable was registered cumulative sickness absence hours during 12 months follow-up. Secondary outcomes were work status as well as pain intensity and functional disability, measured at baseline, 3 and 12 months follow-up. The economic evaluation (intervention costs, productivity loss, and health care utilization costs) was based on administrative data derived from national registries. Results For the time intervals 0-6 months, 6-12 months, and the entire follow-up period, the number of sickness absence hours was significantly lower in the CTWR group as compared to the control group. The total costs saved in CTWR participants compared to controls were estimated at US $1,366 per person at 6 months follow-up and US$ 10,666 per person at 12 months follow-up. Conclusions Workers on sick leave for 4-12 weeks due to MSD who underwent "CTWR" by an interdisciplinary team had fewer sickness absence hours than controls. The economic evaluation showed that-in terms of productivity loss-CTWR seems to be cost saving for the society

Reproduced, reinterpreted, lost: Trajectories of scientific knowledge across contexts

This article reports on a research project that uses two innovative heuristics to examine the changes that texts – produced to disseminate new scientific knowledge – undergo when they travel across space and time. A critical analysis of such transformations would enhance our understanding of the processes involved in knowledge dissemination and inform the practice of communicating scientific knowledge to a variety of audiences. Based on our study of 520 closely linked science and science-related sources collected over 12 months in 2016, we argue that when scientific knowledge is re-contextualized to be disseminated to different audiences, it is not simply rephrased or simplified to make it more accessible. Rather, it also undergoes transformational processes that involve issues of social power, authority and access that require new analytical tools to surface more clearly. We report on the methodology of the study with a particular focus on its heuristics, and the transformations that result from a critical analysis of the data collected. We finally discuss a number of theoretical and practical implications in relation to contemporary practices for re-entextualizing scientific knowledge