A complete sample of quasars from the 7C redshift survey

We present details of a new sample of radio-loud quasars drawn from 0.013 sr of the 7C Redshift Survey. This sample is small (21 quasars) but complete in that every object with an unresolved nucleus and/or broad emission lines with S(151MHz) > 0.5 Jy has been discovered. The dependence of the quasar fraction with redshift and radio luminosity is investigated, providing new evidence supporting the unification of radio-loud quasars and powerful radio galaxies. This 7C sample is compared with optically-selected quasars, in order to determine whether there are systematic biases in the different selection techniques. There are no lightly reddened (Av approx. 1) quasars in our sample amongst the 14 with z < 2. The discovery of a reddened quasar at z = 2.034 and its implications are discussed. A tight correlation between radio luminosity and optical/near infrared continuum luminosity for a subset of the sample is also found.Comment: 6 pages Latex, To appear in the "Cosmology with the New Radio Surveys" Conference - Tenerife 13-15 January 199

Reflections Upon our Way of Invoking an Indigenous Paradigm to Co-Explore Community Mobilization against Irresponsible Practices of Foreign-Owned Companies in Nwoya District, Uganda

This article offers our reflections upon how we invoked an Indigenous paradigm in undertaking/facilitating qualitative research in a setting in Northern Uganda (2020/2021). The research was aimed at co-exploring with participants how they mobilized as a community against social and environmental injustices attendant with the entry of certain foreign enterprises into their community. We set up four focus group sessions in three villages to generate discussion in regard to how they had built up a community protest (with some success) against the operations of two enterprises who had been operational in the community. In our article we do not concentrate so much on the content of the focus group sessions (or the ensuing dissemination/discussion workshop), but rather, on how we enacted our understanding of an Indigenous paradigm in this research initiative. In this way we share possibilities for activating an Indigenous paradigm in the doing of research. We do this in order to help strengthen and further credentialize this paradigm in academic paradigmatic discourses and help secure its respected place on the paradigmatic “dance floor” (to use a metaphor offered by Chilisa, 2020)

The evaluation of small airway disease in the human lung with special reference to tests which are suitable for epidemiological screening

It has been known for several years that small airways of the lung (<2 mm internal diameter) may be defective in the absence of either clinical symptoms or abnormal function tests such as Forced Expiratory Volume in one second (FEV1), Forced Vital Capacity (FVC) or Peak Expiratory Flow Rate (PEFR). Interest in this "silent zone" has led to the development of special tests of small airway function. Some of these special tests including Frequency Dependence of Compliance and Deposition Patterns using radionuclide tagged particles are not readily adaptable to epidemiological screening. Others such as measurements of instantaneous flow rates on Maximal and Partial Expiratory Flow Volume (MEFV and PEFV) curves and the determination of Closing Volume (CV), are more suitable since they are obtained from gas flow at the mouth. A relatively inexpensive apparatus was constructed and used to measure CV, FEV 1, FVC and instantaneous flowrates on MEFV and PEFV curves produced by healthy volunteers (asymptomatic smokers and non smokers), whilst breathing air or a mixture of 80% helium and 20% oxygen (He-02). The position of a characteristic flow volume curve discontinuity (notch) was analysed in 28 volunteer (11 smokers) and was used to effect a measure of separation between the smokers and non smokers. From the systematic difference in MEF 50 and MEF 25 obtained on the MEFV and PEFV curves of 10 males (3 smokers) it is tentatively suggested that the wide predicted normal range for these indices may be related to changes in airway smooth muscle tone. An index of radionuclide particle penetration (Initial Lateral Penetration Index) was as expected positively correlated with PEPR (r= 0.52), FEV1 (r= 0.57) and MEF 50 (r=0.44) and negatively correlated with CV (r= -0.49) in 11 adults confirming that depth of deposition of particles is a sensitive function of airway health. A total of 13 indices were ranked according to the sensitivity and specificity with which drug induced reversible airway changes were detected in a group of 25 volunteers (14 non smokers). Partial (P) indices (obtained from submaximal inspiration) were ranked :- (1) MEF 25 (P) (Air) and MEF 40 (P) (Air). (2) MEF 25 (P) (He); MEF 40 (P) (He) and Isoflow volume point (IFVP). (3) The excess flow rate on He-02 compared to Air {MEF 25 (P) (He/A) and MEF 40 (P) (He/A)}. (4) CV. Correspondingly the ratings for maximal (M) indices were:- (1) MEF 40 (He). (2) MEF 25 (He), ,(3) MEF 40 (Air). (4) IFVP and CV. (5) MEF 25 (Air). (6) FEV1. (7) FVC. (8) CV/SVC (%), MEF 40 (He/A) and MEF 25 (He/A). (9) FEV1/FVC (%). (10) Slow vital capacity. MEF 40 on both air and He-02 was superior to CV and both of these were superior to FEV1 in detecting reversible airway changes

Cassini observations of the thermal plasma in the vicinity of Saturn's main rings and the F and G rings

The ion mass spectrometer on Cassini detected enhanced ion flux near Saturn's main rings that is consistent with the presence of atomic and molecular oxygen ions in the thermal plasma. The ring "atmosphere'' and "ionosphere'' are likely produced by UV photosputtering of the icy rings and subsequent photoionization of O-2. The identification of the O+ and O-2(+) ions is made using time-of-flight analysis and densities and temperatures are derived from the ion counting data. The ion temperatures over the main rings are a minimum near synchronous orbit and increase with radial distance from Saturn as expected from ion pick up in Saturn's magnetic field. The O-2(+) temperatures provide an estimate of the neutral O-2 temperature over the main rings. The ion mass spectrometer also detected significant O-2(+) outside of the main rings, near the F ring. It is concluded that between the F and G rings, the heavy ion population most likely consists of an admixture of O-2(+) and water group ions O+, OH+, and H2O+

Comparison of Primary Open Angle Glaucoma Patients in Rural and Urban Ghana

Purpose: To compare the clinical features of glaucoma patients who present at a rural hospital in North Eastern Ghana and an urban hospital in the capital city of Accra.Methods: This is a multi-center retrospective case series involving records of newly diagnosed glaucoma patients with emphasis on primary open angle glaucoma (POAG). Information collected included basic demographic data, intraocular pressures and optic disc measurements.Results: A total of 949 patients (437 rural; 512 urban; 1868 eyes) were included. Rural vs. urban comparisons, respectively: mean age, 53.2 ± 16.3 vs. 54.5 ± 16.4 years; male: female ratio, 3:2 vs. 1:1; POAG, 78.1% vs. 50.6%; POAG suspect, 10.3% vs. 41.9%; IOP, 39.2 ± 7.1 vs. 31.8 ± 7.3 mmHg; bilateral blindness, 34.1% vs. 17.5%; uniocular blindness, 52.2% vs. 32.9%. Females at the rural hospital were twice as likely to present blind in at least one eye (OR 2.04, CI 1.36 - 3.07, p&lt;0.001).Conclusions: Patients with POAG at the rural hospital present with more advanced disease characteristics.Keywords: glaucoma, open angle,Ghana, Urban, rura

Peroxisomal proliferator activated receptor-γ deficiency in a Canadian kindred with familial partial lipodystrophy type 3 (FPLD3)

BACKGROUND: Familial partial lipodystrophy (Dunnigan) type 3 (FPLD3, Mendelian Inheritance in Man [MIM] 604367) results from heterozygous mutations in PPARG encoding peroxisomal proliferator-activated receptor-γ. Both dominant-negative and haploinsufficiency mechanisms have been suggested for this condition. METHODS: We present a Canadian FPLD3 kindred with an affected mother who had loss of fat on arms and legs, but no increase in facial, neck, suprascapular or abdominal fat. She had profound insulin resistance, diabetes, severe hypertriglyceridemia and relapsing pancreatitis, while her pre-pubescent daughter had normal fat distribution but elevated plasma triglycerides and C-peptide and depressed high-density lipoprotein cholesterol. RESULTS: The mother and daughter were each heterozygous for PPARG nonsense mutation Y355X, whose protein product in vitro was transcriptionally inactive with no dominant-negative activity against the wild-type receptor. In addition the mutant protein appeared to be markedly unstable. CONCLUSION: Taken together with previous studies of human PPARG mutations, these findings suggest that PPAR-γ deficiency due either to haploinsufficiency or to substantial activity loss due to dominant negative interference of the normal allele product's function can each contribute to the FPLD3 phenotype

Why Some Interfaces Cannot be Sharp

A central goal of modern materials physics and nanoscience is control of materials and their interfaces to atomic dimensions. For interfaces between polar and non-polar layers, this goal is thwarted by a polar catastrophe that forces an interfacial reconstruction. In traditional semiconductors this reconstruction is achieved by an atomic disordering and stoichiometry change at the interface, but in multivalent oxides a new option is available: if the electrons can move, the atoms don`t have to. Using atomic-scale electron energy loss spectroscopy we find that there is a fundamental asymmetry between ionically and electronically compensated interfaces, both in interfacial sharpness and carrier density. This suggests a general strategy to design sharp interfaces, remove interfacial screening charges, control the band offset, and hence dramatically improving the performance of oxide devices.Comment: 12 pages of text, 6 figure

Gold nanorods as a contrast agent for Doppler optical coherence tomography

Purpose: To investigate gold nanorods (GNRs) as a contrast agent to enhance Doppler optical coherence tomography (OCT) imaging of the intrascleral aqueous humor outflow. Methods: A serial dilution of GNRs was scanned with a spectral-domain OCT device (Bioptigen, Durham, NC) to visualize Doppler signal. Doppler measurements using GNRs were validated using a controlled flow system. To demonstrate an application of GNR enhanced Doppler, porcine eyes were perfused at constant pressure with mock aqueous alone or 1.0×10 12 GNR/mL mixed with mock aqueous. Twelve Doppler and volumetric SD-OCT scans were obtained from the limbus in a radial fashion incremented by 30°, forming a circular scan pattern. Volumetric flow was computed by integrating flow inside non-connected vessels throughout all 12 scans around the limbus. Results: At the GNR concentration of 0.7×1012 GNRs/mL, Doppler signal was present through the entire depth of the testing tube without substantial attenuation. A well-defined laminar flow profile was observed for Doppler images of GNRs flowing through the glass capillary tube. The Doppler OCT measured flow profile was not statistically different from the expected flow profile based upon an autoregressive moving average model, with an error of -0.025 to 0.037 mm/s (p = 0.6435). Cross-sectional slices demonstrated the ability to view anterior chamber outflow ex-vivo using GNR-enhanced Doppler OCT. Doppler volumetric flow measurements were comparable to flow recorded by the perfusion system. Conclusions: GNRs created a measureable Doppler signal within otherwise silent flow fields in OCT Doppler scans. Practical application of this technique was confirmed in a constant pressure ex-vivo aqueous humor outflow model in porcine eyes. © 2014 Wang et al

Understanding processes of island development on an island braided river over timescales from days to decades

This is the peer reviewed version of the following article: Gurnell, A. M., Bertoldi, W., Francis, R. A., Gurnell, J., and Mardhiah, U. ( 2019) Understanding processes of island development on an island braided river over timescales from days to decades. Earth Surf. Process. Landforms, 44: 624– 640. https://doi.org/10.1002/esp.4494., which has been published in final form at https://doi.org/10.1002/esp.4494. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsBar colonization by vegetation and subsequent island formation is a key bio‐geomorphological process in fluvial landscape evolution. Here we investigate morphological and ecological evolution of river islands over timescales from single floods to decades, focusing on islands initiated by deposited trees that sprout to form vegetated patches. On a braided reach of the high‐energy Tagliamento River, Italy, we monitored 30 pioneer islands of 1 to 17 years age in comparison with unvegetated bar surfaces, open areas between islands, and established island surfaces. We integrated morphological, surface sediment and vegetation properties of islands initiated by different flood events, combining evidence from remotely‐sensed and ground observations, flow and climate time series. At a decadal timescale, pioneer islands aggrade rapidly to the elevation of the mean annual flood, showing a steady increase in vegetation canopy height, fining of surface sediments from predominantly gravel to silty‐sand with a notable clay and organic fraction. The standing vegetation included over 130 species, with the largest number on island surfaces of intermediate elevation and flood disturbance. As islands age, standing vegetation becomes comprised mainly of competitor species with transient seed banks and typical of woodland, scrub, pasture and wetland habitats, whereas the winter seedbank is dominated on all surfaces by ruderal species with persistent seedbanks, mainly associated with aquatic, wetland, pasture, arable and wasteland habitats. At shorter timescales, the biogeomorphological trajectory of pioneer islands is initiated by large flood events that control the elevation of deposited trees, and subsequent flows that control tree survival and establishment. Island morphological evolution depends on the frequency‐magnitude of sediment and seed delivery and redistribution by flood and possibly wind events, whereas island ability to retain sediments reflects the degree of vegetation establishment, which in the short‐term may vary with seasonal to annual moisture supply, substrate characteristics and climatic growth conditions.Ulfah Mardhiah's research was funded by the SMART Joint Doctoral Programme (Science for MAnagement of Rivers and their Tidal systems), which is financed by the Erasmus Mundus Programme of the European Union