Exploring multiple viewshed analysis using terrain features and optimisation techniques

The calculation of viewsheds is a routine operation in geographic information systems and is used in a wide range of applications. Many of these involve the siting of features, such as radio masts, which are part of a network and yet the selection of sites is normally done separately for each feature. The selection of a series of locations which collectively maximise the visual coverage of an area is a combinatorial problem and as such cannot be directly solved except for trivial cases. In this paper, two strategies for tackling this problem are explored. The first is to restrict the search to key topographic points in the landscape such as peaks, pits and passes. The second is to use heuristics which have been applied to other maximal coverage spatial problems such as location-allocation. The results show that the use of these two strategies results in a reduction of the computing time necessary by two orders of magnitude, but at the cost of a loss of 10% in the area viewed. Three different heuristics were used, of which Simulated Annealing produced the best results. However the improvement over a much simpler fast-descent swap heuristic was very slight, but at the cost of greatly increased running times. © 2004 Elsevier Ltd. All rights reserved

Poverty and Economic Freedom: Evidence from Cross-Country Data

This paper explores the empirical relationship between poverty and economic freedom. In doing so, it estimates the levels of absolute poverty for a panel of over forty developing countries and then utilizes fixed effects and GMM-IV estimators to derive the empirical relationships. The principal empirical results that emerge from this exercise indicate that important indicators of economic freedom such as openness to trade and small size of the government are robustly associated with poverty reduction. Labor market flexibility, which reflects an important dimension of economic freedom, does not have a significant effect on poverty on average. However, there is some evidence that trade's beneficial impact on poverty has been smaller in economies with more regulated labor markets. Finally, civil liberties that encompass various types of important economic freedom such as poverty rights, rule of law, etc., also contribute significantly to poverty reduction. This result contrasts with that for political liberties, which have seemingly no impact on poverty reduction. All these suggest that economic freedom is as much important for economic growth as for poverty reduction.

A Serendipitous XMM-Newton Observation of the Intermediate Polar WX Pyx

We briefly describe a serendipitous observation of the little-studied intermediate polar WX Pyx using XMM-Newton. The X-ray spin period is 1557.3 sec, confirming the optical period published in 1996. An orbital period of approximately 5.54 hr is inferred from the separation of the spin-orbit sidelobe components. The soft and hard band spin-folded light curves are nearly sinusoidal in shape. The best-fit spectrum is consistent with a bremsstrahlung temperature of about 18 keV. An upper limit of approximately 300 eV is assigned to the presence of Fe line emission. WX Pyx lies near TX and TV Col in the P_spin-P_orb plane.Comment: 5 pages, 5 figs; accepted A&A 2004 Dec

LMS Based Adaptive Channel Estimation for LTE Uplink

In this paper, a variable step size based least mean squares (LMS) channel estimation (CE) algorithm is presented for a single carrier frequency division multiple access(SC-FDMA) system under the umbrella of the long term evolution (LTE). This unbiased CE method can automatically adapts the weighting coefficients on the channel condition. Therefore, it does not require knowledge of channel,and noise statistics. Furthermore, it uses a phase weighting scheme to eliminate the signal fluctuations due to noise and decision errors. Such approaches can guarantee the convergence towards the true channel coefficient. The mean and mean square behaviors of the proposed CE algorithm are also analyzed. With the help of theoretical analysis and simulation results, we prove that the proposed algorithm outperforms the existing algorithms in terms of mean square error (MSE) and bit error rate (BER) by more than around 2.5dB

Orai1 inhibitor STIM2?? regulates myogenesis by controlling SOCE dependent transcriptional factors

Store-operated Ca2+ entry (SOCE), the fundamental Ca2+ signaling mechanism in myogenesis, is mediated by stromal interaction molecule (STIM), which senses the depletion of endoplasmic reticulum Ca2+ stores and induces Ca2+ influx by activating Orai channels in the plasma membrane. Recently, STIM2??, an eight-residue-inserted splice variant of STIM2, was found to act as an inhibitor of SOCE. Although a previous study demonstrated an increase in STIM2?? splicing during in vitro differentiation of skeletal muscle, the underlying mechanism and detailed function of STIM2?? in myogenesis remain unclear. In this study, we investigated the function of STIM2?? in myogenesis using the C2C12 cell line with RNA interference-mediated knockdown and CRISPR-Cas-mediated knockout approaches. Deletion of STIM2?? delayed myogenic differentiation through the MEF2C and NFAT4 pathway in C2C12 cells. Further, loss of STIM2?? increased cell proliferation by altering Ca2+ homeostasis and inhibited cell cycle arrest mediated by the cyclin D1-CDK4 degradation pathway. Thus, this study identified a previously unknown function of STIM2?? in myogenesis and improves the understanding of how cells effectively regulate the development process via alternative splicing

Reducible Correlations in Dicke States

We apply a simple observation to show that the generalized Dicke states can be determined from their reduced subsystems. In this framework, it is sufficient to calculate the expression for only the diagonal elements of the reudced density matrices in terms of the state coefficients. We prove that the correlation in generalized Dicke states $|GD_N^{(\ell)}>$ can be reduced to $2\ell$-partite level. Application to the Quantum Marginal Problem is also discussed.Comment: 12 pages, single column; accepted in J. Phys. A as FT

Laterally wedged insoles in knee osteoarthritis: do biomechanical effects decline after one month of wear?

<p>Abstract</p> <p>Objective</p> <p>This study aimed to determine whether the effect of laterally wedged insoles on the adduction moment in knee osteoarthritis (OA) declined after one month of wear, and whether higher reported use of insoles was associated with a reduced effect on the adduction moment at one month.</p> <p>Methods</p> <p>Twenty people with medial compartment OA underwent gait analysis in their own shoes wearing i) no insoles and; ii) insoles wedged laterally 5° in random order. Testing occurred at baseline and after one month of use of the insoles. Participants recorded daily use of insoles in a log-book. Outcomes were the first and second peak external knee adduction moment and the adduction angular impulse, compared across conditions and time with repeated measures general linear models. Correlations were obtained between total insole use and change in gait parameters with used insoles at one month, and change scores were compared between high and low users of insoles using general linear models.</p> <p>Results</p> <p>There was a significant main effect for condition, whereby insoles significantly reduced the adduction moment (all p < 0.001). However there was no significant main effect for time, nor was an interaction effect evident. No significant associations were observed between total insole use and change in gait parameters with used insoles at one month, nor was there a difference in effectiveness of insoles between high and low users of the insoles at this time.</p> <p>Conclusion</p> <p>Effects of laterally wedged insoles on the adduction moment do not appear to decline after one month of continuous use, suggesting that significant wedge degradation does not occur over the short-term.</p

DA Wand: Distortion-Aware Selection using Neural Mesh Parameterization

We present a neural technique for learning to select a local sub-region around a point which can be used for mesh parameterization. The motivation for our framework is driven by interactive workflows used for decaling, texturing, or painting on surfaces. Our key idea is to incorporate segmentation probabilities as weights of a classical parameterization method, implemented as a novel differentiable parameterization layer within a neural network framework. We train a segmentation network to select 3D regions that are parameterized into 2D and penalized by the resulting distortion, giving rise to segmentations which are distortion-aware. Following training, a user can use our system to interactively select a point on the mesh and obtain a large, meaningful region around the selection which induces a low-distortion parameterization. Our code and project page are currently available.Comment: Project page: https://threedle.github.io/DA-Wand/ Code: https://github.com/threedle/DA-Wan

Management of osteoarthritis of the knee

Osteoarthritis is a chronic disease; management should be patient centred and coordinated, with attention to modifiable risk factors and comorbidities Focus on conservative non-drug treatment, particularly exercise; for overweight or obese patients weight loss is recommended Management should be evidence based; do not use interventions with high cost and risk that outweigh their benefits Use paracetamol or non-steroidal anti-inflammatory drugs for pain relief, with due attention to precautions and contraindications Refer patients to a physiotherapist for exercise, manual therapy, and gait aids; orthotist for bracing; psychologist for cognitive behavioural therapy; and dietitian for nutritional advice Do not use arthroscopy for pain management; refer patients for joint replacement only when symptoms are severe and other treatments have faile