Dengue is a mosquito-borne disease caused by virus and found mostly in urban and semi-urban areas, in many regions of the world. Female Aedes mosquitoes, which usually bite during daytime, spread the disease. This flu-like disease may progress to severe dengue and cause fatality. A generic reaction-diffusion model for transmission of mosquito-borne diseases was proposed and formulated. The motivation is to explore the ability of the generic model to reproduce observed dengue cases in Borneo, Malaysia. Dengue prevalence in four districts in Borneo namely Kuching, Sibu, Bintulu and Miri are compared with simulations results obtained from the temporal and spatio-temporal generic model respectively. Random diffusion of human and mosquito populations are taken into account in the spatio-temporal model. It is found that temporal simulations closely resemble the general behavior of actual prevalence in the three locations except for Bintulu. The recovery rate in Bintulu district is found t...

Concurrent constraint programming is classically based on asynchronous communication via a shared store. In previous work ([1, 2]), we presented a new version of the ask and tell primitives which features synchronicity, our approach being based on the idea of telling new information just in the case that a concurrently running process is asking for it. We turn in this paper to a semantic study of this new framework, called Scc. It is first shown to be different in nature from classical concurrent constraint programming and from CCS, a classical reference in traditional concurrency theory. This suggests the interest of new semantics for Scc. To that end, an operational semantics reporting the steps of the computations is presented. A denotational semantics is then proposed. It uses monotonic sequences of labelled pairs of input-output states, possibly containing gaps, and ending – according to the logic programming tradition – with marks reporting success or failure. This denotationa...

This experiment aimed to study effect of levels of molasses in oil palm frond silage on intake digestibility coefficient, nitrogen balance and rumen fermentation characteristics in goats. Four Thai NativexAnglo-Nubian 50% crossbred male goat, 2.7-2.8 years old with average body weight (BW) of 35.1+1.6 kg, were arranged in 4x4 Latin Square design. The goats were fed with oil palm frond silage mixed with molasses 0, 2, 4 and 6% ad libitum and supplemented with concentrate at 0.5% of BW as dry matter basis. The results showed that there were no significant differences (P>0.05) among treatments regarding nutrient intake and digestibility coefficients of dry matter, organic matter and crude protein. Nitrogen balance, ruminal pH and blood urea nitrogen (BUN) of all groups were not significantly differences (P>0.05). Thus, it is not necessary to add molasses in oil palm frond silage.

Sweet cherry (Prunus avium L.) is considered as one of the most important temperate zone fruits worldwide. It is an economical fruit with high demand because of its early ripening fruits that enter the market early in the season. Most sweet cherry cultivars are self-incompatible, not able to produce commercial fruit without being pollinated with a compatible pollinizer. In the present study, flowers of cv. Zarde Daneshkadea were hand pollinated using collected pollen from Sefid Rezaeieh, Napoleon, Abardeh, Bing, Shabestar cultivars as well as ...

This paper investigates the Diffie-Hellman key exchange scheme over the group F∗ p of nonzero elements of finite fields and shows that there exist exponents k, l satisfying certain conditions called the modulus conditions, for which the Diffie Hellman Problem (DHP) can be solved in polynomial number of operations in m without solving the discrete logarithm problem (DLP). These special private keys of the scheme are termed weak and depend also on the generator a of the cyclic group. More generally the triples (a, k, l) with generator a and one of private keys k, l weak, are called weak triples. A sample of weak keys is computed and it is observed that their number may not be insignificant to be ignored in general. Next, an extension of the analysis and weak triples is carried out for the Diffie Hellman scheme over the matrix group GLn and it is shown that for an analogous class of session triples, the DHP can be solved without solving the DLP in polynomial number of operations in the...

Micro- and macroscale experiments which document the dynamics of salt damage to porous stone have yielded data which expose weaknesses in earlier interpretations. Previously unexplained differences are found in crystal morphology, crystallization patterns, kinetics and substrate damage when comparing the growth of mirabilite (Na2SO4. 10H2O) and thenardite (Na2SO4) versus halite (NaCl). The crystallization pattern of sodium sulphate was strongly affected by relative humidity (RH), while a lesser RH effect was observed for sodium chloride. Macroscale experiments confirmed that mirabilite (crystallizing at RH>50 per cent) and thenardite (crystallizing at RH<50 per cent) tend to form subflorescence in highly localized areas under conditions of constant RH and temperature. This crystallization pattern was more damaging than that of halite, since halite tended to grow as efflorescence or by filling the smallest pores of the stone in a homogeneous fashion, a result which contradicts Wellman and Wilson's theoretical model of salt damage. Low RH promoted rapid evaporation of saline solutions and higher supersaturation levels, resulting in the greatest damage to the stone in the case of both sodium sulphate and sodium chloride crystallization. At any particular crystallization condition, sodium chloride tended to reach lower supersaturation levels (resulting in the crystallization of isometric crystals) and created negligible damage, while sodium sulphate reached higher supersaturation ratios (resulting in non-equilibrium crystal shapes), resulting in significant damage. ESEM showed no damage from sodium sulphate due to hydration. Instead, after water condensation on thenardite crystals, rapid dissolution followed by precipitation of mirabilite took place, resulting in stone damage by means of crystallization pressure generation. It is concluded that salt damage due to crystallization pressure appears to be largely a function of solution supersaturation ratio and location of crystallization. These key factors are related to solution properties and evaporation rates, which are constrained by solution composition, environmental conditions, substrate properties, and salt crystallization growth patterns. When combined with a critical review of salt damage literature, these experiments allow the development of a model which explains variations in damage related to combinations of different salts, substrates and environmental conditions.

Suppose an &quot;escaping&quot; player moves continuously at maximum speed 1 in the interior of a region, while a &quot;pursuing&quot; player moves continuously at maximum speed r outside the region. For what r can the first player escape the region, that is, reach the boundary a positive distance away from the pursuing player, assuming optimal play by both players? We formalize a model for this infinitesimally alternating 2-player game that we prove has a unique winner in any region with locally rectifiable boundary, avoiding pathological behaviors (where both players can have &quot;winning strategies&quot;) previously identified for pursuit-evasion games such as the Lion and Man problem in certain metric spaces. For some regions, including both equilateral triangle and square, we give exact results for the critical speed ratio, above which the pursuing player can win and below which the escaping player can win (and at which the pursuing player can win). For simple polygons, we giv...