Fratricidal rebels: ideological extremity and warring factionalism in civil wars

The article of record as published may be found at http://dx.doi.org/10.1080/09546553.2017.1389726Why do rebels kill each other? When confronting a formidable regime, rebels often descend into warring factionalism rather than forge unity across their ranks to reap the advantages of cooperation. This article tackles the puzzle of inter-rebel fratricide. It explores power and resource competition arguments, and contrasts them with ideological mechanisms that can drive inter-rebel violence. It argues that ideological extremity is central to rebel fratricide. Rebel organizations with common ideological origins can still compete with each other based on their degree of centrism and extremism, making them ideologically distant. This proximity-distance paradox makes their cohabitation mutually threatening. Ideological challengers from the same family tree are particularly threatening to one’s group cohesion, and if successful, guarantee one’s political marginalization within the broader movement. Extremist groups are likely to respond to these threats with fratricide, while ideologically centrist ones will rely on other strategies such as balancing, outbidding, or defecting to manage their rivalries. Algeria’s civil war, 1992–2002, is a plausibility probe case study that illustrates these causal mechanisms. The study contributes to a burgeoning literature on the role of ideology in armed civil conflicts

Thresholds Optimization for One-Bit Feedback Multi-User Scheduling

We propose a new one-bit feedback scheme with scheduling decision based on the maximum expected weighted rate. We show the concavity of the $2$-user case and provide the optimal solution which achieves the maximum weighted rate of the users. For the general asymmetric M-user case, we provide a heuristic method to achieve the maximum expected weighted rate. We show that the sum rate of our proposed scheme is very close to the sum rate of the full channel state information case, which is the upper bound performance

The radicalization puzzle: a theoretical synthesis of empirical approaches to homegrown extremism

The article of record as published may be found at http://dx.doi.org/10.1080/1057610X.2015.1051375Why and how do individuals residing in relatively peaceful and affluent Western societies come to embrace extremist ideologies that emanate from distant places? We summarize the most recent empirical literature on the causes and dynamics of radicalization, and evaluate the state of the art in the study of Islamist homegrown extremism in the West. We propose a theoretical synthesis based on four factors that come together to produce violent radicalization: personal and collective grievances, networks and interpersonal ties, political and religious ideologies, and enabling environments and support structures. We propose adopting a “puzzle” metaphor that represents a multifactor and contextualized approach to understanding how ordinary individuals transform into violent extremists. We concluded with three recommendations to strengthen the empirical foundations of radicalization studies

Numerical algorithms for steady and unsteady incompressible Navier-Stokes equations

The numerical analysis of the incompressible Navier-Stokes equations are becoming important tools in the understanding of some fluid flow problems which are encountered in research as well as in industry. With the advent of the supercomputers, more realistic problems can be studied with a wider choice of numerical algorithms. An alternative formulation is presented for viscous incompressible flows. The incompressible Navier-Stokes equations are cast in a velocity/vorticity formulation. This formulation consists of solving the Poisson equations for the velocity components and the vorticity transport equation. Two numerical algorithms for the steady two-dimensional laminar flows are presented. The first method is based on the actual partial differential equations. This uses a finite-difference approximation of the governing equations on a staggered grid. The second method uses a finite element discretization with the vorticity transport equation approximated using a Galerkin approximation and the Poisson equations are obtained using a least squares method. The equations are solved efficiently using Newton's method and a banded direct matrix solver (LINPACK). The method is extended to steady three-dimensional laminar flows and applied to a cubic driven cavity using finite difference schemes and a staggered grid arrangement on a Cartesian mesh. The equations are solved iteratively using a plane zebra relaxation scheme. Currently, a two-dimensional, unsteady algorithm is being developed using a generalized coordinate system. The equations are discretized using a finite-volume approach. This work will then be extended to three-dimensional flows

Mothers attributes and supervision behaviors relevant to child injury

Background: Home injuries are a major health problem in children. They are the most common cause of death in children under 5 years of age. Every year they leave many thousands permanently disabled. Most of these accidents are preventable through increased awareness and improvements in the home environment.Objectives: To assess mothers attitude about home related injuries among children younger than 5 years of age.Patients and methods: A cross-sectional study included 330 mothers conducted in health unit of Safour Village, Diarb Negm District, Sharqia Governorate. A predesigned validated questionnaire was administered to mothers who have children equal or less than five years old to assess the parent supervision attributes profile.Results: the result revealed that mothers have satisfactory score as regard subscale of protectiveness, risk tolerance and supervision beliefs respectively (84.8%, 74.5% and 72.2%).Conclusion: Mothers in Diarb Negm district have satisfactory supervision attribute as regards home injuries of their under five years children

Reducing Precoder/Channel Mismatch and Enhancing Secrecy in Practical MIMO Systems Using Artificial Signals

Practical multiple-input-multiple-output (MIMO) systems depend on a predefined set of precoders to provide spatial multiplexing gain. This limitation on the flexibility of the precoders affects the overall performance. Here, we propose a transmission scheme that can reduce the effect of mismatch between users' channels and precoders. The scheme uses the channel knowledge to generate an artificial signal, which realigns the predefined precoder to the actual channel. Moreover, the scheme can provide an additional level of secrecy for the communication link. The performance of the proposed scheme is evaluated using bit-error rate (BER), error vector magnitude (EVM), and secrecy capacity. The results show a significant improvement for the legitimate user, along with a degradation for the eavesdropper.Comment: 4 pages, 5 figures. Accepted for publication in IEEE Communications Letter

An investigation into the current utilisation and prospective of renewable energy resources and technologies in Libya

With the increase in energy demand and the international drive to reduce carbon emission from fossil fuel, there has been a drive in many oil-rich countries to diversify their energy portfolio and resources. Libya is currently interested in utilising its renewable energy resources in order to reduce the financial and energy dependency on oil reserves. This paper investigates the current utilisation and the future of renewable energy in Libya. Interviews have been conducted with managers, consultants and decision makers from different government organisations including energy policy makers, energy generation companies and major energy consumers. The results indicate that Libya is rich in renewable energy resources but in urgent need of a more comprehensive energy strategy and detailed implementation including reasonable financial and educational investment in the renewable energy sector

Comparison of serum cystatin C and creatinine based methods in detection of early renal dysfunction in critically ill patients

Early detection of renal dysfunction is of importance inthe care of critically ill patients. Cystatin C was proposedto be superior to serum creatinine in estimation of renal function. This work aimed to compare serum cystatin Cto serum creatinine and creatinine based formulae indetection of early decline in renal function at a singlepoint in critically ill patients. Fifty critically ill patientsadmitted to Cairo University Hospitals ICUs - Egypt wereincluded. Patients with chronic renal disease,thyroid disease, malignancy, patients receivingcorticosteroid therapy, with serum creatinine > 1.4 mg/dland patients receiving diuretics or large volumes of IVfluids were excluded. Serum creatinine, serum cystatinC, adjusted creatinine clearance (Adj Ccr), estimatedGFR (eGFR) by modification of diet in renal disease(MDRD), abbreviated MDRD (abb MDRD) andCockcroft-Gault (CG) formulae were measured. Patientswith renal dysfunction (adj Ccr < 80 ml/min/1.73m2)were 26 (52%) in number. Patients with renaldysfunction and high serum creatinine were 12/26(46.2%) while those with high cystatin C were 23/26(88.5%). Cystatin C was found to be significantlycorrelated with serum creatinine, adj Ccr and eGFR by all studied formulae. Using receiver operatingcharacteristic (ROC) analysis; AUC for Cystatin C(0.976) was more than that for eGFR by abb MDRD(AUC=0.839), MDRD (AUC=0.822), CG formulae(AUC=0.808) and serum creatinine (AUC=0.710)respectively. In conclusion; cystatin C was found to bebetter than serum creatinine, eGFR by abb MDRD,MDRD and CG formulae in detection of early renaldysfunction at a single point in critically ill patients

Seasonal fluctuations of population density of the cabbage aphid, Brevicoryne brassicae (L.), in the Netherlands, and the role of its parasite, Aphidius (Diaeretiella) rapae (Curtis)

Brevicoryne brassicae (L.) had 4-14 generations in the year, it overwintered in the egg stage on cruciferous plants and reached a peak of abundance on brussels sprouts in July, rapidly declined and increased again in September-October. The mid-season decline proved to be due to increased mortality rather than to reduction of reproduction or to migration.Abiotic factors and biotic factors, entomophagous fungi, predators and parasites, Aphidius rapae, (Curtis) were all involved.A. rapae was an internal parasite, only one adult emerged from each host. The parasite overwintered as a last-instar-larva inside the host. The adults emerged in spring. There were 5-11 generations a year each lasting 14-16 days. Eggs were deposited singly and at random in infested aphids. Half-grown nymphs seemed to be preferred to other stages and wingless to winged.Parasitism eliminated reproduction completely if it occurred early in the host development but not necessarily if it were delayed until the fourth instar or later. Host development was always delayed.Parasitism caused only a small proportion of total aphid mortality though it sometimes reached 80-90 % of the stem-mothers on overwintered brussels sprouts. Hyperparasites, like Charips ancylocera, reduced effectiveness. Also the slower development of A. rapae than of B.brassicae reduced its effectiveness