Size and Structure of the Narrow-Line Region of Quasars

We have observed the narrow-line regions (NLRs) of the seven brightest radio-quiet PG (or BQS) quasars (z < 0.5) with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST). Linear-ramp filters were used to image the [OIII] lambda 5007 line emission with 0.0455-0.1 arcsec pixel resolution. We find that the NLRs are very compact with typical extents of 2-4 arcsec. Two quasars show compact filamentary structures similar to Seyfert NLRs. They may be related to radio outflows. Most interestingly, when including a sample of Seyfert galaxies observed with HST, we tentatively find that the size of the NLR is proportional to the square root of the [OIII] luminosity. This is comparable to the scaling found for the size of the broad-line region with continuum luminosity, which has been interpreted in terms of a constant photoionization parameter. The relation determined here connects the NLR of radio-quiet quasars and Seyferts over three orders of magnitude in [OIII] luminosity.Comment: 6 pages, 4 figures, accepted for publication in ApJ Letter

'Reaching the hard to reach' - lessons learned from the VCS (voluntary and community Sector). A qualitative study.

Background The notion 'hard to reach' is a contested and ambiguous term that is commonly used within the spheres of social care and health, especially in discourse around health and social inequalities. There is a need to address health inequalities and to engage in services the marginalized and socially excluded sectors of society. Methods This paper describes a pilot study involving interviews with representatives from eight Voluntary and Community Sector (VCS) organisations . The purpose of the study was to explore the notion of 'hard to reach' and perceptions of the barriers and facilitators to accessing services for 'hard to reach' groups from a voluntary and community sector perspective. Results The 'hard to reach' may include drug users, people living with HIV, people from sexual minority communities, asylum seekers, refugees, people from black and ethnic minority communities, and homeless people although defining the notion of the 'hard to reach' is not straight forward. It may be that certain groups resist engaging in treatment services and are deemed hard to reach by a particular service or from a societal stance. There are a number of potential barriers for people who may try and access services, including people having bad experiences in the past; location and opening times of services and how services are funded and managed. A number of areas of commonality are found in terms of how access to services for 'hard to reach' individuals and groups could be improved including: respectful treatment of service users, establishing trust with service users, offering service flexibility, partnership working with other organisations and harnessing service user involvement. Conclusions: If health services are to engage with groups that are deemed 'hard to reach' and marginalised from mainstream health services, the experiences and practices for engagement from within the VCS may serve as useful lessons for service improvement for statutory health services

Nxele, Ntsikana and the origins of the Xhosa religious reaction

The sudden expulsion of the Xhosa across the Fish River in 1811–12 created a practical and conceptual crisis which the traditional political authorities were unable to resolve. Two commoners, Nxele and Ntsikana, emerged in this vacuum, each proposing his own solution to the problems posed by the white irruption. Although these responses were religious responses, they were neither irrational nor incomprehensible. Xhosa religion had long functioned as an instrument for the control of the material world. By incorporating selected Christian concepts with the Xhosa world-view, Nxele and Ntsikana were able to provide the Xhosa with acceptable explanations of past events and prescriptions for future action. Nxele urged resistance and Ntsikana preached submission, but an examination of their personal histories shows that these final conclusions were more the product of exterior pressure than interior revelation. It may be suggested that the future reputations of the two men, like their past actions, will be determined more by the popular mood than by anything they themselves did or said

Author&apos;s personal copy Leishmania donovani lacking the Golgi GDP-Man transporter LPG2 exhibit attenuated virulence in mammalian hosts

a b s t r a c t Surface phosophoglycans such as lipophosphoglycan (LPG) or proteophosphoglycan (PPG) and glycosylinositol phospholipids (GIPLs) modulate essential interactions between Leishmania and mammalian macrophages. Phosphoglycan synthesis depends on the Golgi GDP-mannose transporter encoded by LPG2. LPG2-null (lpg2 À ) Leishmania major cannot establish macrophage infections or induce acute pathology, whereas lpg2 À Leishmania mexicana retain virulence. lpg2 À Leishmania donovani has been reported to survive poorly in cultured macrophages but in vivo survival has not been explored. Herein we discovered that, similar to lpg2 À L. major, lpg2 À L. donovani promastigotes exhibited diminished virulence in mice, but persisted at consistently low levels. lpg2 À L. donovani promastigotes could not establish infection in macrophages and could not transiently inhibit phagolysosomal fusion. Furthermore, lpg2 À promastigotes of L. major, L. donovani and L. mexicana were highly susceptible to complement-mediated lysis. We conclude that phosphoglycan assembly and expression mediated by L. donovani LPG2 are important for promastigote and amastigote virulence, unlike L. mexicana but similar to L. major. Published by Elsevier Inc

In vivo Imaging of Transgenic Leishmania Parasites in a Live Host

Abstract Distinct species of Leishmania, a protozoan parasite of the family Trypanosomatidae, typically cause different human disease manifestations. The most common forms of disease are visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). Mouse models of leishmaniasis are widely used, but quantification of parasite burdens during murine disease requires mice to be euthanized at various times after infection. Parasite loads are then measured either by microscopy, limiting dilution assay, or qPCR amplification of parasite DNA. The in vivo imaging system (IVIS) has an integrated software package that allows the detection of a bioluminescent signal associated with cells in living organisms. Both to minimize animal usage and to follow infection longitudinally in individuals, in vivo models for imaging Leishmania spp. causing VL or CL were established. Parasites were engineered to express luciferase, and these were introduced into mice either intradermally or intravenously. Quantitative measurements of the luciferase driving bioluminescence of the transgenic Leishmania parasites within the mouse were made using IVIS. Individual mice can be imaged multiple times during longitudinal studies, allowing us to assess the inter-animal variation in the initial experimental parasite inocula, and to assess the multiplication of parasites in mouse tissues. Parasites are detected with high sensitivity in cutaneous locations. Although it is very likely that the signal (photons/second/parasite) is lower in deeper visceral organs than the skin, but quantitative comparisons of signals in superficial versus deep sites have not been done. It is possible that parasite numbers between body sites cannot be directly compared, although parasite loads in the same tissues can be compared between mice. Examples of one visceralizing species (L. infantum chagasi) and one species causing cutaneous leishmaniasis (L. mexicana) are shown. The IVIS procedure can be used for monitoring and analyzing small animal models of a wide variety of Leishmania species causing the different forms of human leishmaniasis. Protocol Infection of small animals with transgenic Leishmania Parasite lines Transgenic Leishmania spp. parasites expressing luciferase are generated using an episomal or an integrating vector as reported. 1 2 Clonal lines are preferred. Two important points are: (a) Integrated luciferase is preferred over episomal luciferase, since in theory these parasite lines should better retain the transgene in the absence of drug pressure, i.e. after introduction into a mammal. However even integrated transgenes can be lost at low rates, 3 so it is critical to maintain selective drug pressure on the stock culture. In practice, Leishmania spp. often retain episomal elements for extended time periods even in vivo, although with variation in plasmid copy number per cell. (b) The Leishmania spp. parasites can lose virulence during in vitro culture. In some species (e.g. L. donovani, L. infantum chagasi) this loss can occur rapidly over weeks of culture. In other species (e.g., L. major, L. mexicana) virulence is retained longer term, for months to years. Nonetheless, clonal transfectants should be screened to identify those retaining full virulence for small animals. Many labs will serially pass the parasites several times (4 or more) through mice or hamsters to augment virulence prior to use in experiments. Preparation of infective metacyclic stage parasites for infection The infective form of Leishmania spp. that is transmitted by the sand fly to the mammalian host is the metacyclic promastigote. 5 Therefore, animal infections with this form of the parasite are preferred as a model of natural infection. Although sand flies are difficult to maintain, parasites grown in vitro will conveniently undergo metacyclogenesis. The percent of metacyclics present in a culture will vary with the number of passes since isolation from the animal, the culture media and the parasite species and strain. Metacyclics can be purified by positive or negative selection depending on the species and line of Leishmania. Changes in the terminal or side chain carbohydrate residues of the abundant surface lipophosphoglycan (LPG) of L. major allow it to be purified by loss of agglutination with the lectin PNA (peanut agglutinin). Choice of route for inoculation of Leishmania spp. into the host The clinical disease manifestations of human leishmaniasis vary depending on both the species of parasite and host factors. There are corresponding differences in murine infection, leading investigators to use different models and routes of infection. For example, species causing human CL (e.g. L. major, L. mexicana, L. amazonensis) are often inoculated into mice subcutaneously in the footpad or intradermally in the ear. Pre-treatment of mice with anesthetic Wild-type, transgenic or gene knockout mice can be used. Although not formally, quantified, it seems most likely that nude or albino such as BALB/c mice allow for greater light transmission through tissue compared to mice with dark skin and hair pigment such as C57BL/6. Injectable anesthestic agents such as a mixture of ketamine plus xylazine [80-100 mg/kg + 10 mg/kg, respectively, intraperitoneally (i.p.)] diluted in saline is one preferred method, since the animals will be lightly anesthetized for at least 10 minutes with a single dose. 100-200ul total volume is injected i.p. using a 25-30 gauge needle. The animals are manually restrained firmly by their dorsal skin with their abdomen up and head pointed down. The needle should be positioned with the bevel up and slightly angled. The tip of the needle should just slightly penetrate the lower left quadrant of the abdominal wall. An inhalant anesthetic such as isoflurane can alternately be used, but animals will only remain under anesthesia for as long as they are inhaling the anesthetic agent. Infection of mice with Leishmania spp. parasites Once the animals are lightly anesthetized, the infection sites are cleaned with 70% ethyl or isopropyl alcohol. The parasite species, dose and infection route is determined by the investigator. The injection volume should be minimized to prevent excessive tissue damage for intradermal (10 μl) or intramuscular (25-50 μl) infection routes. The allowable injection volumes in mice can be larger for intravenous (100-200 μl), subcutaneous (up to 2 ml) or intraperitoneal (up to 2 ml) infection routes. Infection routes and volumes used in our experiments include intradermal in the ear pinna Bioluminescent imaging of Leishmania using the IVIS (in vivo imaging system) Preparation of D-luciferin for in vivo bioluminescent imaging D-Luciferin (Caliper LifeSciences) is reconstituted to a concentration of 15 mg/ml in Dulbecco&apos;s PBS with or without Mg 2+ and Ca 2+ , and syringe filtered (0.2 μm). Aliquots are frozen at -80°C until use. Prior to injection, luciferin is warmed to 37°C in a water bath. Injection of D-luciferin The injection site is cleaned and luciferin is introduced into conscious animals by an intraperitoneal injection of a 15 mg/ml luciferin solution in DPBS, at a dose of 150 mg/kg. Luciferin can also be injected into anesthetic-treated animals, but the bioluminescence kinetics may vary slightly. Once injected into animals, luciferin circulates rapidly. It is useful to empirically determine the optimal time to acquire luminescent data after luciferin injection for each experimental model and for different anatomical locations of the mice, because the kinetics of luciferin distribution may vary. A kinetic curve is generated by acquiring a sequence of replicate images. Animals are lightly anesthetized Inhalant or injectable anesthetics may be used for the imaging procedure. Isoflurane is simpler to administer at this stage, since most IVIS systems have an attached anesthesia chamber and anesthesia nose cone manifold inside the imaging chamber. The anesthesia is split between the anesthesia chamber and the manifold inside the imaging chamber. The animals are placed in the clear Plexiglass anesthesia chamber and lightly anesthetized with 2.5-3.5% isoflurane. Animals are visually monitored to ensure an effective degree of anesthesia has been induced, and that their breathing is unhindered. Sufficient degree of anesthesia is verified by lack of withdrawal from painful paw pressure. The amount of isoflurane may be reduced to 1.5-2% after animals are lightly anesthetized. Bioluminescent data is collected Adequately anesthetized animals are transferred from the anesthesia chamber to the imaging chamber and positioned so that the nose cones attached to the manifold will deliver a continuous and regulated flow of isoflurane. The Pressing Acquire or Acquire continuous photos in the IVIS System Control window initiates image and data acquisition on the IVIS. Acquisition times can range from a few seconds up to several minutes. For our experiments, we use the 60 second default exposure setting. A Close-up image (small FOV) may provide greater resolution, but not necessarily enhanced sensitivity compared to an image taken using a larger FOV. After the imaging procedure, animals are removed from the imaging chamber, returned to their cages and monitored until they recover from the anesthesia. Data analysis The luminescence data is analyzed using the Living Image software (Xenogen) and corresponds to the light intensity expressed as the number of photons detected by the CCD camera. These data are represented by a pseudo-color image that is overlaid on to a black and white photograph of the animals. Specific areas of the image may be analyzed by creating regions of interest (ROI). The Living Image software does provide a variety of data output options. One of the simplest ways to analyze the data is to select a region of interest ( ROI ) and measure the average # of photons/second that is detected. These data can then be exported to a spread sheet such as Microsoft Office Excel (Microsoft Corporation). GraphPad Prism (GraphPad Software) was subsequently used to generate graphs for this manuscript. Representative Results Summary: IVIS technology enables the visualization of luciferase-expressing Leishmania spp. parasites in living anesthetized BALB/c mice in real-time. Once the substrate luciferin distributes through tissues, the rapid oxidation of D-luciferin by luciferase expressed by the transgenic parasites causes light to be emitted. The photons that are not absorbed by the tissue are detected at the surface of the animal by the CCD camera of the IVIS imaging technology

Genome assemblies across the diverse evolutionary spectrum of Leishmania protozoan parasites

We report the high-quality draft assemblies and gene annotations for 13 species and/or strains of the protozoan parasite gener

High mannose N-glycans on red blood cells as phagocytic ligands, mediating both sickle cell anaemia and resistance to malaria

Acknowledgements We are grateful for the assistance provided by both the Microscopy and Histology Core Facility, and the Iain Fraser Cytometry Centre, at the University of Aberdeen. We thank Ann Wheeler and Matt Pearson from Edinburgh Super-Resolution Imaging Consortium for technical support with 3D SIM microscopy. We also thank Janet A. Willment and Bernard Kerscher, supervised by G.D.B., for providing the Fc fusion proteins, Jeanette A. Wagener, supervised by Neil A.R.G. Gow, for providing high purity chitin, Jan Westland for obtaining blood samples and Paul Crocker for useful discussions. Principal funding for this project was provided by Wellcome Trust grant 094847 (R.N.B, L.P.E, M.A.V). In addition, support was provided by Biotechnology and Biological Sciences Research Council grants BBF0083091 (A.D. and S.M.H.) and BBK0161641 (A.D. and S.M.H.), Wellcome Trust grant 082098 (A.D.), Wellcome Trust grants 97377, 102705 (G.D.B) and funding for the MRC Centre for Medical Mycology at the University of Aberdeen MR/N006364/1 (G.D.B).Non peer reviewe

Red blood cell mannoses as phagocytic ligands mediating both sickle cell anaemia and malaria resistance

Acknowledgements We are grateful for the assistance provided by both the Microscopy and Histology Core Facility, and the Iain Fraser Cytometry Centre, at the University of Aberdeen. We thank Ann Wheeler and Matt Pearson from Edinburgh Super-Resolution Imaging Consortium for technical support with 3D SIM microscopy. We also thank Janet A. Willment and Bernard Kerscher, supervised by G.D.B., for providing the Fc fusion proteins, Jeanette A. Wagener, supervised by Neil A.R.G. Gow, for providing high purity chitin, Jan Westland for obtaining blood samples and Paul Crocker for useful discussions. Principal funding for this project was provided by Wellcome Trust grant 094847 (R.N.B., L.P.E., M.A.V.). In addition, support was provided by Biotechnology and Biological Sciences Research Council grants BBF0083091 (A.D. and S.M.H.) and BBK0161641 (A.D. and S.M.H.), Wellcome Trust grant 082098 (A.D.), Wellcome Trust grants 97377, 102705 (G.D.B.), and funding for the MRC Centre for Medical Mycology at the University of Aberdeen MR/N006364/1 (G.D.B.).Peer reviewedPublisher PD

Development and initial validation of the Influences on Patient Safety Behaviours Questionnaire

YesBackground: Understanding the factors that make it more or less likely that healthcare practitioners (HCPs) will perform certain patient safety behaviors is important in developing effective intervention strategies. A questionnaire to identify determinants of HCP patient safety behaviors does not currently exist. This study reports the development and initial validation of the Influences on Patient Safety Behaviors Questionnaire (IPSBQ) based on the Theoretical Domains Framework. Methods: Two hundred and thirty-three HCPs from three acute National Health Service Hospital Trusts in the United Kingdom completed the 34-item measure focusing on one specific patient safety behavior (using pH as the first line method for checking the position of a nasogastric tube). Confirmatory factor analysis (CFA) was undertaken to generate the model of best fit. Results: The final questionnaire consisted of 11 factors and 23 items, and CFA produced a reasonable fit: χ2 (175) = 345.7, p < 0.001; CMIN/DF = 1.98; GFI = 0.90 and RMSEA = 0.06, as well as adequate levels of discriminant validity, and internal consistency (r = 0.21 to 0.64). Conclusions: A reliable and valid theoretically underpinned measure of determinants of HCP patient safety behavior has been developed. The criterion validity of the measure is still unknown and further work is necessary to confirm the reliability and validity of this measure for other patient safety behaviors