21 research outputs found

    Mobility as a contradictory resource: Peripatetic Qur’anic students in Kano, Nigeria

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    Mobility is a powerful resource young people can draw on to improve their lives, but it can also entail risks. This paper explores how mobility becomes a contradictory resource for peripatetic Qur'anic students (almajirai) in Kano State in northern Nigeria. Moving to urban areas allows the young almajirai to escape difficult conditions and to access educational and income opportunities absent in their rural homes. It makes it possible for them to adopt self-conceptions as migrants in search of sacred knowledge who were once widely respected. However, economic decline has made survival in the city more difficult. Lacking the economic and cultural resources to participate in displays of status, and without social superiors to speak for them, the almajirai feel they have become fair game for those searching for scapegoats

    The African experience : essays

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    Vol. 1xi, 655 p.; 23 cm

    Greenland basal water distribution from airborne radar sounding (2003-2014)

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    There is widespread, but often indirect, evidence that a significant fraction of the bed beneath the Greenland Ice Sheet is thawed (at or above the pressure melting point for ice). This includes the beds of major outlet glaciers and their tributaries and a large area around the NorthGRIP borehole in the ice-sheet interior. The ice-sheet scale distribution of basal water is, however, poorly constrained by existing observations. In principle, airborne radio-echo sounding (RES) enables the detection of basal water from bed-echo reflectivity, but unambiguous mapping is limited by uncertainty in signal attenuation within the ice. Here we introduce a new, RES diagnostic for basal water that is associated with wet-dry transitions in bed material: bed-echo reflectivity variability. This technique acts as a form of edge detector and is a sufficient, but not necessary, criteria for basal water. However, the technique has the advantage of being attenuation-insensitive and suited to data combination enabling combined analysis of over a decade of Operation IceBridge survey data. The basal water predictions are compared with existing analyses of the basal thermal state (frozen and thawed beds) and geothermal heat flux. In addition to the outlet glaciers, we demonstrate widespread water storage in the northern and eastern interior. Notably, we observe a quasi-linear 'corridor' of basal water extending from NorthGRIP to Petermann glacier that spatially correlates with elevated heat flux predicted by a recent magnetic model. Finally, with a general aim to stimulate regional- and process-specific investigations, the basal water predictions are compared with bed topography, subglacial flow paths, and ice-sheet motion. The basal water distribution, and its relationship with the thermal state, provides a new constraint for numerical models

    Radiostratigraphy and age structure of the Greenland Ice Sheet.

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    Several decades of ice-penetrating radar surveys of the Greenland and Antarctic ice sheets have observed numerous widespread internal reflections. Analysis of this radiostratigraphy has produced valuable insights into ice sheet dynamics and motivates additional mapping of these reflections. Here we present a comprehensive deep radiostratigraphy of the Greenland Ice Sheet from airborne deep ice-penetrating radar data collected over Greenland by The University of Kansas between 1993 and 2013. To map this radiostratigraphy efficiently, we developed new techniques for predicting reflection slope from the phase recorded by coherent radars. When integrated along track, these slope fields predict the radiostratigraphy and simplify semiautomatic reflection tracing. Core-intersecting reflections were dated using synchronized depth-age relationships for six deep ice cores. Additional reflections were dated by matching reflections between transects and by extending reflection-inferred depth-age relationships using the local effective vertical strain rate. The oldest reflections, dating to the Eemian period, are found mostly in the northern part of the ice sheet. Within the onset regions of several fast-flowing outlet glaciers and ice streams, reflections typically do not conform to the bed topography. Disrupted radiostratigraphy is also observed in a region north of the Northeast Greenland Ice Stream that is not presently flowing rapidly. Dated reflections are used to generate a gridded age volume for most of the ice sheet and also to determine the depths of key climate transitions that were not observed directly. This radiostratigraphy provides a new constraint on the dynamics and history of the Greenland Ice Sheet.Key pointsPhase information predicts reflection slope and simplifies reflection tracingReflections can be dated away from ice cores using a simple ice flow modelRadiostratigraphy is often disrupted near the onset of fast ice flow

    Effect of ruboxistaurin in patients with diabetic macular edema: Thirty-month results of the randomized PKC-DMES clinical trial

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    Objective: To evaluate the safety and efficacy of orally administered ruboxistaurin (RBX) as a mesylate salt in patients with diabetic macular edema (DME). 1 Design: Multicenter, double-masked, randomized, placebo-controlled study of 686 patients receiving placebo or RBX orally ( 4, 16, or 32 mg/d) for 30 months. At baseline, patients had DME farther than 300 mu m from the center of the macula, an Early Treatment Diabetic Retinopathy Study retinopathy severity level from 20 to 47A without prior photocoagulation, and an Early Treatment Diabetic Retinopathy Study visual acuity of 75 or more letters in the study eye. The primary study outcome was progression to sight-threatening DME or application of focal/grid photocoagulation for DME. Main Outcome Measure: Masked grading of stereoscopic fundus photographs. Results: The delay in progression to the primary outcome was not statistically significant ( 32 mg of RBX vs placebo, P=.14 [unadjusted]; Cox proportional hazards model adjusted for covariates, hazards ratio=0.73; 95% confidence interval, 0.53-1.0; P=.06). However, application of focal/ grid photocoagulation prior to progression to sight-threatening DME varied by site, and a secondary analysis of progression to sight-threatening DME alone showed that 32 mg of RBX per day reduced progression, compared with placebo (P=.054 [ unadjusted]; Cox proportional hazards model, hazards ratio= 0.66; 95% confidence interval, 0.47-0.93; P=.02). Conclusions: Although progression to the primary outcome was not delayed, daily oral administration of RBX may delay progression of DME to a sight-threatening stage. Ruboxistaurin was well tolerated in this study
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