124,469 research outputs found
The role of social media in the collaboration, interaction, co-creation and co-delivery of a social venture in an uncertain conflict environment
This research case study examines the creation and development of a bottom-up social enterprise immediately after the outbreak of a civil war in an Arab country by a group of young patriots in the aftermath of the Arab Spring uprisings in the 2010s. Drawing on Linders’ (2012) model of social action lifecycle, our study examines how different actors become involved and co-created a socially entrepreneurial venture (SEV), how these actors contributed to the coproduction and co-delivery of the social actions (values) over time, and how social media play
roles in these processes. Drawing from the empirical evidences of citizen co-production within the existing literature, we found that SEVs operate in very different ways in which the role of social media is critical, both from their equivalents operating in a penurious but stable
environment, and those intending to pursue political action within a conflict situation. In our case study, social media was not intended for mass-mobilisation, but for selected mobilisation amongst those within the network. This is due to the insecure environment and the fear of
infiltration from opposing parties. We also examine how new actors were, over time, being carefully screened and selected, and potential harmful existing players being excluded, which in turn contributed to the evolving nature of the social enterprises
Recommended from our members
CO2 plume evolution in a depleted natural gas reservoir: Modeling of conformance uncertainty reduction over time
Uncertainty in the long-term fate of CO2 injected for geologic carbon sequestration (GCS) is a significant barrier to the adoption of GCS as a greenhouse-gas emission-mitigation for industry and regulatory agencies alike. We present a modeling study that demonstrates that the uncertainty in forecasts of GCS site performance decreases over time as monitoring data are used to update operational models. We consider a case study of GCS in a depleted natural gas reservoir, with CO2 injection occurring over 20 years, with a 50-year post-injection site care period. We constructed a detailed model to generate the actual model output, which is considered synthetic observation data. A series of simpler operational models based on limited data and assumptions about how an operator would model such a site are then run and compared against actual model output at specific monitoring points after one year, two years, etc. The operational model is updated and improved using the synthetic observation data from the actual model at the same time intervals. Model parameter values and model features needed to be updated over time to improve matches to the actual model. These kinds of model adjustments would be a normal part of reservoir engineering and site management at GCS sites. Uncertainty in two key measures related to site performance decreases with time: extent of the CO2 plume up-dip migration, and radial extent of the pressure pulse. This conclusion should help allay the concerns of industry and regulators about uncertainty in long-term fate of CO2 at GCS sites
The effect of sea quarks on the mass of the charm quark from Lattice QCD
We compute the mass of the charm quark using both quenched and dynamical
lattice QCD calculations. We examine the effects of mass dependent lattice
artifacts by comparing two different formalisms for the heavy quarks. We take
the continuum limit of the charm mass in quenched QCD by extrapolating from
three different lattice spacings. At a fixed lattice spacing, the mass of the
charm quark is compared between quenched QCD and dynamical QCD with a sea quark
mass around strange. In the continuum limit of quenched QCD, we find
m_c(m_c)=1.29(7)(13) GeV. No evidence was seen for unquenching.Comment: Added NP analysis of quenched data, corrected error in PCAC RGI mass,
updated strange quark mass discussion and references, unified notation and
corrected typos. No change in final result. Version accepted for publication
in JHE
Atmospheric teleconnection mechanisms of extratropical North Atlantic SST influence on Sahel rainfall
Extratropical North Atlantic cooling has been tied to droughts over the Sahel in both paleoclimate observations and modeling studies. This study, which uses an atmospheric general circulation model (GCM) coupled to a slab ocean model that simulates this connection, explores the hypothesis that the extratropical North Atlantic cooling causes the Sahel droughts via an atmospheric teleconnection mediated by tropospheric cooling. The drying is also produced in a regional climate model simulation of the Sahel when reductions in air temperature (and associated geopotential height and humidity changes) from the GCM simulation are imposed as the lateral boundary conditions. This latter simulation explicitly demonstrates the central role of tropospheric cooling in mediating the atmospheric teleconnection from extratropical North Atlantic cooling. Diagnostic analyses are applied to the GCM simulation to infer teleconnection mechanisms. An analysis of top of atmosphere radiative flux changes diagnosed with a radiative kernel technique shows that extratropical North Atlantic cooling is augmented by a positive low cloud feedback and advected downstream, cooling Europe and North Africa. The cooling over North Africa is further amplified by a reduced greenhouse effect from decreased atmospheric specific humidity. A moisture budget analysis shows that the direct moisture effect and monsoon weakening, both tied to the ambient cooling and resulting circulation changes, and feedbacks by vertical circulation and evaporation augment the rainfall reduction. Cooling over the Tropical North Atlantic in response to the prescribed extratropical cooling also augments the Sahel drying. Taken together, they suggest a thermodynamic pathway for the teleconnection. The teleconnection may also be applicable to understanding the North Atlantic influence on Sahel rainfall over the twentieth century
Craniometaphyseal and craniodiaphyseal dysplasia, head and neck manifestations and management
Craniometaphyseal and craniodiaphyseal dysplasia are rare genetic disorders of bone due to modelling errors of long bones and skull bones. These syndromes present with multiple ENT symptomatology from an early age. The diagnostic distinction can now be made radiologically by serial skeletal survey which is important for prognosis. We review the clinical, radiological, computed tomography (CT) scan, otological, audiological and histopathological findings in two cases with craniodiaphyseal, and two cases with craniometaphyseal dysplasia, and report our experiences of medical and surgical treatment to date. In the craniodiaphyseal dysplasia, the hearing abnormality progressed from an initial conductive to a mixed loss on serial audiometric follow up. Temporal bone CT scans showed narrowing of the middle ear cavity, internal auditory meatus, and facial nerve canal at the geniculate ganglion. Benefits from choanal stenosis surgery, craniofacial remodelling and dacrocystorhinostomy were shortlived. Calcitriol therapy with a low calcium diet did not alter the clinical course of progression in our cases. The underlying defect, causing net bone formation in these phenotypically similar syndromes, appears to be different when based on the differing biochemical responses to calcitriol and bone biopsy findings. Increased numbers of osteoblasts were found in bone biopsies from both cases with craniodiaphyseal dysplasia. Early recognition is crucial in these conditions as therapy directed at the underlying bony defect has the best chance of success if initiated in infancy (Cole et al., 1988; Fanconi et al., 1988; Key et al., 1988)
- …