Radiation damage in the LHCb vertex locator

The LHCb Vertex Locator (VELO) is a silicon strip detector designed to reconstruct charged particle trajectories and vertices produced at the LHCb interaction region. During the first two years of data collection, the 84 VELO sensors have been exposed to a range of fluences up to a maximum value of approximately 45 × 1012 1 MeV neutron equivalent (1 MeV neq). At the operational sensor temperature of approximately −7 °C, the average rate of sensor current increase is 18 μA per fb−1, in excellent agreement with predictions. The silicon effective bandgap has been determined using current versus temperature scan data after irradiation, with an average value of Eg = 1.16±0.03±0.04 eV obtained. The first observation of n+-on-n sensor type inversion at the LHC has been made, occurring at a fluence of around 15 × 1012 of 1 MeV neq. The only n+-on-p sensors in use at the LHC have also been studied. With an initial fluence of approximately 3 × 1012 1 MeV neq, a decrease in the Effective Depletion Voltage (EDV) of around 25 V is observed. Following this initial decrease, the EDV increases at a comparable rate to the type inverted n+-on-n type sensors, with rates of (1.43±0.16) × 10−12 V/ 1 MeV neq and (1.35±0.25) × 10−12 V/ 1 MeV neq measured for n+-on-p and n+-on-n type sensors, respectively. A reduction in the charge collection efficiency due to an unexpected effect involving the second metal layer readout lines is observed

Epidemiology of hip fracture in Botswana

Summary A retrospective population-based survey in the Republic of Botswana determined the incidence of fractures at the hip over 3 years. The estimated number of such fractures nationwide for 2020 was 103 and is predicted to increase. Objective This article describes the epidemiology of hip fractures in the Republic of Botswana. Methods A retrospective patient chart review was conducted to identify from hospital registers the number of patients diagnosed with hip fracture in 2009, 2010, and 2011. Age- and sex-specific incidence of hip fracture was determined from which lifetime probabilities and future projections for hip fracture were calculated. Results The incidence of hip fracture was low and comparable to rates reported from Tunisia. The remaining lifetime risk of hip fracture at the age of 50 years in men and women was 1.4 and 1.1%, respectively. The incidence of hip fracture suggested that the estimated number of hip fractures nationwide in persons over the age of 50 years for 2020 was 103 and is predicted to increase by more than threefold to 372 in 2050. Conclusion The hip fracture rates can be used for healthcare planning. Additionally, these data can be used to create a FRAX model to help guide decisions about treatment

Bio-Geo-Graphy: Landscape, Dwelling, and the Political Ecology of Human-Elephant Relations

The relation between the bio and the geo has been amongst geography's most enduring concerns. This paper contributes to ongoing attempts in human geography to politicise the dynamics and distribution of life. Drawing upon postcolonial environmental history, animal ecology, and more-than-human geography, the paper examines how humans and elephants cohabit with and against the grain of cartographic design. Through fieldwork in northeast India, it develops a ‘dwelt political ecology’ that reanimates landscape as a dwelt achievement whilst remaining sensitive to postcolonial histories and subaltern concerns. The paper conceptualises and deploys a methodology of ‘tracking’ through which archival material, elephant ecology, and voices of the marginalised can be integrated and mapped. It concludes by discussing the implications of this work for fostering new conversations between more-than-human geography and subaltern political ecology

Development of a Lower Limb Arthroplasty Service in a Developing Country: Lessons learned after the first 100 cases (joints)

There is emerging evidence that total hip arthroplasty (THR) can be safely practiced in developing countries but scant evidence of safety of total knee replacement (TKR). The purpose of this study is to evaluate the outcomes of these procedures focusing on procedure related complications. This is a retrospective study of the first 100 arthroplasties (92 patients) consisting of 58 TKR and 42 THR with a minimum follow-up of 26 months (range of 26 to 47 months). Major complications included deep infection in one TKR and dislocation of one THR and one TKR.  Two patients died in the second post-operative week from cardiac events following TKR. Blood transfusion rate for hips and knees was 13.7% and 5.6% respectively.  THR can be safely performed in less than ideal circumstances in developing countries in carefully selected patients. More importantly this study demonstrates that TKR can be safely practiced under the same circumstances