1,279 research outputs found
Urban Ecology and the Effectiveness of Aedes Control
Past initiatives to control Aedes mosquitoes were successful, in part because they implemented draconian top-down control programs. To achieve similar results now, explicit recognition of the complexity in urban ecologies in terms of land ownership, law enforcement and accessibility for control interventions are required. By combining these attributes, four classes of spaces, along with corresponding control strategies, are suggested to better target Aedes species population control efforts. On one end of the spectrum there are accessible and accountable spaces (e.g. backyards and closely managed public facilities), where interventions can rely predominantly on bottom-up strategies with the local population playing the principle role in the implementation of actions, but with government coordination. On the other end of the spectrum are inaccessible and unaccountable spaces, which require top-down and extensive approaches. By identifying these and the intermediate classes of space, government and private resources can be allocated in a more efficient customized manner. Based on this new framework, a set of actions is proposed that might be implemented in dengue and other Aedes-borne crises. The framework considers existing limitations and opportunities associated with modern societies–which are fundamentally different from those associated with the successful control of Aedes species in the past
Robust grid adaptation for efficient uncertainty quantification
In the recent past, adjoint methods have been successfully applied in error estimation of integral outputs (functionals) of the numerical solution of partial differential equations. The adjoint solution can also be used as a grid adaptation indicator, with the objective of optimally targeting and reducing the numerical error in the functional of interest below a prespecified threshold. In situations where we seek to quantify the effect of aleatory uncertainties on statistical moments of the output functional, it becomes necessary to evaluate the functional accurately at multiple sample points in probability space. If the numerical accuracy of these sample evaluations is not uniform, variations in the numerical error can affect the evaluation of the statistical moments. Although it is possible to independently adapt the meshes to obtain more accurate solutions at each sample point in stochastic space, such a procedure can be both cumbersome and computationally expensive. To improve the efficiency of this process, a new robust grid adaptation technique is proposed that is aimed at minimizing the numerical error over a range of variations of the uncertain parameters of interest about a nominal state. Using this approach, it is possible to generate computational grids that are insensitive to small variations of the uncertain parameters that can both locally and globally change the solution and, as a result, the error distribution. This is in contrast with classical adjoint techniques, which seek to adapt the grid with the aim of minimizing numerical errors for a specific flow condition (and geometry). It is demonstrated that flow computations on these robust grids result in low numerical errors under the expected range of variations of the uncertain input parameters. The effectiveness of this strategy is demonstrated in problems involving the Poisson equation and the Euler equations at transonic and supersonic/hypersonic speeds
Inter-observer variation in the assessment of clinical signs in sick Tanzanian children
We assessed the inter-observer agreement in identification of a range of 24 clinical signs associated with disease presentation in 327 children aged 0·41) although there was only fair agreement (Kappa-score 0·21-0·40) in the detection of neck stiffness and chest indrawing and slight agreement in the detection of dehydration (Kappa-score 0·199). All objective neurological signs were less reliably assessed in infants than in older children. The difficulties surrounding the diagnosis of impaired consciousness in young children should increase vigilance in the diagnosis and management of neurological complications of illnesses in infanc
Rotura traumática del tendón del supraespinoso en un niño de seis años
Presentamos un caso de un niño de seis años que sufrió un traumatismo por caída sobre su hombro derecho, con rotura completa del tendón del supraespinoso. Comprobado con Resonancia Magnética. Se operó para efectuar una reinserción transósea del tendón mediante cirugía abierta. Después de un mes de inmovilización se comenzaron los ejercicios activos progresivos con recuperación completa a los tres meses de la intervención.A six year old boy sustained a right shoulder injury after a causal fall. Magnetic Resonance Imaging showed a complete rupture of the supraespinatus tendon. Open surgery was indicated by transosseus reinsertion of the tendon on the humeral head. After one month of shoulder immobilization, the patient physical therapy with progressive active exercises. The patient achivied complete joint motion and function three months after surgery
The incidence of clinical malaria detected by active case detection in children in Ifakara, southern Tanzania
Between July 2000 and June 2001, we used weekly active case detection (ACD) of clinical malaria episodes in 618 children aged <5 years to describe the epidemiology of malaria in Ifakara, southern Tanzania. Plasmodium falciparum-positive blood slides prepared from children with axillary temperature ⩾ 37.5°C were used to define clinical malaria and a rolling cross-sectional survey documented the prevalences of parasitaemia and anaemia. A random subsample of children was visited daily for 1 month at the end of the study to assess the effect of more frequent visits on estimated incidence rates. Only 50 (8%) children had 1 or more episodes of clinical malaria during the year, an overall incidence of 0.275 episodes/100 child-weeks-at-risk, with no age dependence. The maximum parasite prevalence of 25% was reached in children aged 4 years. The incidence of illness was significantly lower in children visited daily than in those visited weekly., suggesting a marked effect of frequent visits on estimated incidence rates. We conclude that the age pattern of malaria detected through ACD is a more robust epidemiological indicator than absolute incidence rate estimates and that, in contrast to the surrounding area, Ifakara town is subject to only moderate perennial malaria transmissio
Heat and Work Along Individual Trajectories of a Quantum Bit
We use a near quantum limited detector to experimentally track individual quantum state trajectories of a driven qubit formed by the hybridization of a waveguide cavity and a transmon circuit. For each measured quantum coherent trajectory, we separately identify energy changes of the qubit as heat and work, and verify the first law of thermodynamics for an open quantum system. We further establish the consistency of these results by comparison with the master equation approach and the two-projective-measurement scheme, both for open and closed dynamics, with the help of a quantum feedback loop that compensates for the exchanged heat and effectively isolates the qubit
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