Knowing What, Knowing How, or Knowing Where? How Technology Challenges Concepts of Knowledge

When bringing innovative technology into school education it has been challenging to get full benefits from the technology. Instead of seeking new ways of teaching we tend to adapt the use of technology to traditional ways of teaching. This can relate to the fact that we lack theoretical concepts that help us rethink and revise our practices. In Norwegian curriculum we see different learning discourses represented, that makes it difficult to change our concept of knowledge. It is therefore time to look for new ways of understanding the concept of knowledge, to be able to build new perspective on learning and teaching that opens for a more innovate way of using technology in education. George Siemens’ connectivism gives interesting contributions to this transformative process, and may inspire to new concepts of knowledge

Characteristics of hearing-impairment among patients in Ghana

The causes, and characteristics of hearing-impairment were determined prospectively among six thousand, four hundred and twenty-eight (6,428) patients who reported at the Komfo Anokye Teaching Hospital (KATH) with hearing problems. The purpose of the study was to determine the characteristics and some causes of hearing loss of patients who report for management at Komfo Anokye Teaching Hospital. The procedure adopted included a detailed case history, Otoscopy and Pure-tone Audiometry. Of the 6,428 patients, 5,734 (89.9%) were diagnosed as having significant hearing loss. There were more hearing impaired women than men at all ages. Majority of the patients had mild hearing loss. The overall prevalence of Sensorineural Hearing Loss was more in worse ear than better ear. Again, the occurrence of Sensorineural Hearing Loss was more than other types of hearing loss. Noise, Fever, Presbycusis, Sickness, Meningitis and Meniere\'s diseases were the major causes of Sensorineural Hearing Loss. Conductive Hearing Loss was attributed in the main to Wax, Foreign Bodies, Otitis Media, and Traumas. These findings have important implications on the need of resources for rehabilitation. African Journal of Health Sciences Vol. 13 (1-2) 2008: pp. 110-11

Natural resources conflicts and the biofuel industry: implications and proposals for Ghana

Africa has become an important target producer of the feedstock, Jatropha curcas L (JCL), for biofuel production. This presents opportunities for transforming production, markets and the well-being of farmers and rural populations in developing countries, if deals are well-structured. The history of natural resource use conflicts in Africa has important implications for understanding current resource ecology and the social and political relationships within it. Ghana has had varying resource management regimes in its history. This paper seeks to relate the history of Ghana's natural resources conflicts to the current rush for lands in Ghana forcultivation of JCL and to discuss its implications and opportunities for a sustainable JCL industry in the countly. The colonial and postcolonial land conflicts and politics and the current and potential conflicts and opportunities associated with the JCL indust1y are presented. The paper offers suggestions not only for a sustainable cultivation of Jatropha, but alsofor a biofuel policy in Ghana.Keywords: Biofuel; natural resources conflicts,- land grabbing; Jatrophacurcas; Ghana

Fiber Orientation Estimation Guided by a Deep Network

Diffusion magnetic resonance imaging (dMRI) is currently the only tool for noninvasively imaging the brain's white matter tracts. The fiber orientation (FO) is a key feature computed from dMRI for fiber tract reconstruction. Because the number of FOs in a voxel is usually small, dictionary-based sparse reconstruction has been used to estimate FOs with a relatively small number of diffusion gradients. However, accurate FO estimation in regions with complex FO configurations in the presence of noise can still be challenging. In this work we explore the use of a deep network for FO estimation in a dictionary-based framework and propose an algorithm named Fiber Orientation Reconstruction guided by a Deep Network (FORDN). FORDN consists of two steps. First, we use a smaller dictionary encoding coarse basis FOs to represent the diffusion signals. To estimate the mixture fractions of the dictionary atoms (and thus coarse FOs), a deep network is designed specifically for solving the sparse reconstruction problem. Here, the smaller dictionary is used to reduce the computational cost of training. Second, the coarse FOs inform the final FO estimation, where a larger dictionary encoding dense basis FOs is used and a weighted l1-norm regularized least squares problem is solved to encourage FOs that are consistent with the network output. FORDN was evaluated and compared with state-of-the-art algorithms that estimate FOs using sparse reconstruction on simulated and real dMRI data, and the results demonstrate the benefit of using a deep network for FO estimation.Comment: A shorter version is accepted by MICCAI 201

Large entropy production inside black holes: a simple model

Particles dropped into a rotating black hole can collide near the inner horizon with enormous energies. The entropy produced by these collisions can be several times larger than the increase in the horizon entropy due to the addition of the particles. In this paper entropy is produced by releasing large numbers of neutrons near the outer horizon of a rotating black hole such that they collide near the inner horizon at energies similar to those achieved at the Relativistic Heavy Ion Collider. The increase in horizon entropy is approximately 80 per dropped neutron pair, while the entropy produced in the collisions is 160 per neutron pair. The collision entropy is produced inside the horizon, so this excess entropy production does not violate Bousso's bound limiting the entropy that can go through the black hole's horizon. The generalized laws of black hole thermodynamics are obeyed. No individual observer inside the black hole sees a violation of the second law of thermodynamicsComment: 10 page

Bounded Verification with On-the-Fly Discrepancy Computation

Simulation-based verification algorithms can provide formal safety guarantees for nonlinear and hybrid systems. The previous algorithms rely on user provided model annotations called discrepancy function, which are crucial for computing reachtubes from simulations. In this paper, we eliminate this requirement by presenting an algorithm for computing piece-wise exponential discrepancy functions. The algorithm relies on computing local convergence or divergence rates of trajectories along a simulation using a coarse over-approximation of the reach set and bounding the maximal eigenvalue of the Jacobian over this over-approximation. The resulting discrepancy function preserves the soundness and the relative completeness of the verification algorithm. We also provide a coordinate transformation method to improve the local estimates for the convergence or divergence rates in practical examples. We extend the method to get the input-to-state discrepancy of nonlinear dynamical systems which can be used for compositional analysis. Our experiments show that the approach is effective in terms of running time for several benchmark problems, scales reasonably to larger dimensional systems, and compares favorably with respect to available tools for nonlinear models.Comment: 24 page

The effect of vitamin C on upper respiratory infections in adolescent swimmers: A randomized trial

The risk of upper respiratory infections (URIs) is increased in people who are under heavy physical stress, including recreational and competitive swimmers. Additional treatment options are needed, especially in the younger age group. The aim of this study was to determine whether 1 g/day vitamin C supplementation affects the rate, length, or severity of URIs in adolescent swimmers. We carried out a randomized, double-blind, placebo-controlled trial during three winter months, among 39 competitive young swimmers (mean age 13.8 ± 1.6 years) in Jerusalem, Israel. Vitamin C had no effect on the incidence of URIs (rate ratio = 1.01; 95% confidence interval (CI) = 0.70-1.46). The duration of respiratory infections was 22% shorter in vitamin C group, but the difference was not statistically significant. However, we found a significant interaction between vitamin C effect and sex, so that vitamin C shortened the duration of infections in male swimmers by 47% (95% CI: -80% to -14%), but had no effect on female swimmers (difference in duration: +17%; 95% CI: -38% to +71%). The effect of vitamin C on the severity of URIs was also different between male and female swimmers, so that vitamin C was beneficial for males, but not for females. Our study indicates that vitamin C does not affect the rate of respiratory infections in competitive swimmers. Nevertheless, we found that vitamin C decreased the duration and severity of respiratory infections in male swimmers, but not in females. This finding warrants further research.Peer reviewe