432 research outputs found
The Search for Intergalactic Hydrogen Clouds in Voids
I present the results of a search for intergalactic hydrogen clouds in voids.
Clouds are detected by their HI LyA absorption lines in the HST spectra of
low-redshift AGN. The parameter with which the environments of clouds are
characterized is the tidal field, which places a lower limit on the cloud
mass-density which is dynamically stable against disruption. Galaxy redshift
catalogs are used to sum the tidal fields along the lines of sight, sorting
clouds according to tidal field upper, or lower limits. The analytical
methodology employed is designed to detect gas clouds whose expansion following
reionization is restrained by dark matter perturbations. End-products are the
cloud equivalent width distribution functions (EWDF) of catalogs formed by
sorting clouds according to various tidal field upper, or lower limits.
Cumulative EWDFs are steep in voids (S ~ -1.5 \pm 0.2), but flatter in high
tidal field zones (S ~ -0.5 \pm 0.1). Most probable cloud Doppler parameters
are ~30 km/s in voids and ~60 km/s in proximity to galaxies. In voids, the
cumulative line density at low EW (~ 15 mA) is ~ 500 per unit redshift. The
void filling factor is found to be 0.87 <= f_v <= 0.94. The void EWDF is
remarkably uniform over this volume, with a possible tendency for more massive
clouds to be in void centers. The size and nature of the void cloud population
suggested by this study is completely unanticipated by the results of published
3-D simulations, which predict that most clouds are in filamentary structures
around galaxy concentrations, and that very few observable absorbers would lie
in voids. Strategies for modeling this population are briefly discussed.Comment: 21 pages, 19 figures, apjemulate style, to appear in ApJ vol. 57
The four or more medicines (FOMM) support service:results from an evaluation of a new community pharmacy service aimed at over-65s
Background: 57% of all prescriptions dispensed in the UK in 2003 were for people aged ≥60, where ≥20% of them were prescribed ≥ five medicines. Inappropriate prescribing and non-adherence have a significant impact on hospital admissions and patient quality of life. The English government has identified that community pharmacy could make a significant contribution to reducing non-adherence and improving the quality of prescribing, reducing both hospital admissions and medicines wastage. Objective: To evaluate a community pharmacy service aimed at patients over the age of 65 years prescribed four or more medicines. Method: Patients were invited to participate in the service by the community pharmacy team. The pharmacist held regular consultations with the patient and discussed risk of falls, pain management, adherence and general health. They also reviewed the patient’s medication using STOPP/START criteria. Data wereas analysed for the first six months of participation in the service. Key findings: 620 patients were recruited with 441 (71.1%) completing the six month study period. Pharmacists made 142 recommendations to prescribers in 110 patients largely centred on potentially inappropriate prescribing of NSAIDs, PPIs or duplication of therapy. At follow-up there was a significant decrease in the total number of falls (mean -0.116 (-0.217 - -0.014)) experienced and a significant increase in medicines adherence (mean difference in MMAS-8: 0.513 (0.337 – 0.689)) and quality of life. Cost per QALY estimates ranged from £11,885 to £32,466 depending on the assumptions made. Conclusion: By focussing on patients over the age of 65 years with four or more medicines, community pharmacists can improve medicines adherence and patient quality of life
New Observations of Extra-Disk Molecular Gas in Interacting Galaxy Systems, Including a Two-Component System in Stephan's Quintet
We present new CO (1 - 0) observations of eleven extragalactic tails and
bridges in nine interacting galaxy systems, almost doubling the number of such
features with sensitive CO measurements. Eight of these eleven features were
undetected in CO to very low CO/HI limits, with the most extreme case being the
NGC 7714/5 bridge. This bridge contains luminous H II regions and has a very
high HI column density (1.6 X 10^21 cm^-2 in the 55" CO beam), yet was
undetected in CO to rms T(R)* = 2.4 mK. The HI column density is higher than
standard H2 and CO self-shielding limits for solar-metallicity gas, suggesting
that the gas in this bridge is metal-poor and has an enhanced N(H2)/I(CO) ratio
compared to the Galactic value. Only one of the eleven features in our sample
was unambiguously detected in CO, a luminous HI-rich star formation region near
an optical tail in the compact group Stephan's Quintet. We detect CO at two
widely separated velocities in this feature, at ~6000 km/s and ~6700 km/s. Both
of these components have HI and H-alpha counterparts. These velocities
correspond to those of galaxies in the group, suggesting that this gas is
material that has been removed from two galaxies in the group. The
CO/HI/H-alpha ratios for both components are similar to global values for
spiral galaxies.Comment: 39 pages, Latex, 15 figures, Astronomical Journal, in pres
Personalised service? Changing the role of the government librarian
Investigates the feasibility of personalised information service in a government department. A qualitative methodology explored stakeholder opinions on the remit, marketing, resourcing and measurement of the service. A questionnaire and interviews gathered experiences of personalised provision across the government sector. Potential users were similarly surveyed to discuss how the service could meet their needs. Data were analysed using coding techniques to identify emerging theory. Lessons learned from government librarians centred on clarifying requirements, balancing workloads and selective marketing. The user survey showed low usage and awareness of existing specialist services, but high levels of need and interest in services repackaged as a tailored offering. Fieldwork confirmed findings from the literature on the scope for adding value through information management advice, information skills training and substantive research assistance and the need to understand business processes and develop effective partnerships. Concluding recommendations focus on service definition, strategic marketing, resource utilisation and performance measurement
GMRT HI observations of the Eridanus group of galaxies
The GMRT HI 21cm-line observations of galaxies in the Eridanus group are
presented. The Eridanus group, at a distance of ~23 Mpc, is a loose group of
\~200 galaxies. The group extends more than 10 Mpc in projection. The velocity
dispersion of the galaxies in the group is ~240 km/s. The galaxies are
clustered into different sub-groups. The overall population mix of the group is
30% (E+S0) and 70% (Sp+Irr). The observations of 57 Eridanus galaxies were
carried out with the GMRT for ~200 hour. HI emission was detected from 31
galaxies. The channel rms of ~1.0 mJy beam^{-1} was achieved for most of the
image-cubes made with 4 hour of data. The corresponding HI column density
sensitivity (3-sigma) is ~1x10^{20} cm^{-2} for a velocity-width of ~13.4 km/s.
The 3-sigma detection limit of HI mass is ~1.2x10^{7} M_sun for a line-width of
50 km/s. Total HI images, HI velocity fields, global HI line profiles, HI mass
surface densities, HI disk parameters and HI rotation curves are presented. The
velocity fields are analysed separately for the approaching and the receding
sides of the galaxies. This data will be used to study the HI and the radio
continuum properties, the Tully-Fisher relations, the dark matter halos, and
the kinematical and HI lopsidedness in galaxies.Comment: 75 pages including HI atlas; Accepted for publication in Journal of
Astroph. & Astron. March, 200
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The social context of tuberculosis treatment in urban risk groups in the United Kingdom: a qualitative interview study
Objectives: There is scant qualitative research into the experiences of tuberculosis treatment in urban risk groups with complex health and social needs in the UK. This study aimed to describe the social context of adherence to treatment in marginalised groups attending a major tuberculosis centre in London.
Methods: Qualitative cross-sectional study using semi-structured interviews with patients receiving treatment for tuberculosis. Analytical frameworks aimed to reflect the role of broader social structures in shaping individual health actions.
Results: Seventeen participants, the majority were homeless and had complex medical and social needs including, drug and alcohol use or immigration problems affecting entitlement to social welfare. Participants rarely actively chose not to take their medication but described a number of social and institutional barriers to adherence and their need for practical support. Many struggled with the physical aspects of taking medication and the side effects. Participants receiving DOT reported both positive and negative experiences reflecting type of DOT provider and culture of the organisation.
Conclusions: There is a need for integrated care across drug, alcohol, HIV and homeless services in order to address complex clinical co-morbidities and social need which impact on patients’ ability to sustain a course of treatment
Chronic Exposure to Complex Metal Oxide Nanoparticles Elicits Rapid Resistance in Shewanella Oneidensis MR-1
Engineered nanoparticles are incorporated into numerous emerging technologies because of their unique physical and chemical properties. Many of these properties facilitate novel interactions, including both intentional and accidental effects on biological systems. Silver-containing particles are widely used as antimicrobial agents and recent evidence indicates that bacteria rapidly become resistant to these nanoparticles. Much less studied is the chronic exposure of bacteria to particles that were not designed to interact with microorganisms. For example, previous work has demonstrated that the lithium intercalated battery cathode nanosheet, nickel manganese cobalt oxide (NMC), is cytotoxic and causes a significant delay in growth of Shewanella oneidensis MR-1 upon acute exposure. Here, we report that S. oneidensis MR-1 rapidly adapts to chronic NMC exposure and is subsequently able to survive in much higher concentrations of these particles, providing the first evidence of permanent bacterial resistance following exposure to nanoparticles that were not intended as antibacterial agents. We also found that when NMC-adapted bacteria were subjected to only the metal ions released from this material, their specific growth rates were higher than when exposed to the nanoparticle. As such, we provide here the first demonstration of bacterial resistance to complex metal oxide nanoparticles with an adaptation mechanism that cannot be fully explained by multi-metal adaptation. Importantly, this adaptation persists even after the organism has been grown in pristine media for multiple generations, indicating that S. oneidensis MR-1 has developed permanent resistance to NMC
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