6,918 research outputs found
Dengue vector control in Malaysia: a review for current and alternative strategies
Dengue is a major issue in Malaysia as the dramatic emerge of infection. Yet an effective vaccine or medicine is not yet available, although many attempts are undergoing. Dengue vector control is still considered the most effective way for controlling and preventing the transmission of dengue virus. Nonetheless, as the conventional approaches are less successful in managing the dengue transmission, it is time to review the current applied and other available approaches. Current dengue vector relied greatly on the chemical approach as space treatment either thermal or ULV fogging, however, the approach seem like under the expectation. Beside space treatment, new control methods for example biological control (bacterium Bacillus thuringiensis, predatory mosquito Toxorhynchites) and attractive trap were carried out at certain location of Malaysia. Moreover, new emerged approaches such as mass release of genetic modification or artificially Wolbachia infected male dengue vector for the objective of generating sterile offspring when mate with wild population is urge to be tested in Malaysia, although concerns have to be taken before the actual mass release. In conclusion, control of dengue vector shall not consist exclusively for a single approach, neither genetic modification of artificially Wolbachia infected technique, nor the conventional insecticidal treatment. It should, however, comprise of the environment management as the fundamental approach, a well-planned integrated control program and a good cooperation among the organization
Evaluating the biological conversion of paddy husk to house fly, Musca domestica L (Diptera: Muscidae) pupa powder: a study of house fly as animal feed
The sector of livestock and aquaculture are growing rapidly in
order to meet the incremental demand of essential protein for
the world’s population. However, the supply of plant-based
animal feed was limited by resources such as land and water.
The opportunity for insect as the substitute to animal feed is
tremendous; nonetheless, little attention was taken in Malaysia.
In this study, low value bio-waste, paddy husks, which were in
pellet form were prior ground and dried, then fed to larva of
common house fly, Musca domestica L (Diptera: Muscidae).House fly pupae were collected, dried and ground into powder
for analysis. Weight-conversion and nutrition value were studied
by applying standard AOAC and FAO methods. The paddy husk
to pupa weight conversion was 4.10%, in other words, 41g
housefly pupae powder could obtained from 1kg of paddy husk.
For the nutritional analysis, house fly pupae powder consists of
68.90% crude protein, which was significantly higher that the
paddy husk (15.65% crude protein, <0.001). This study
indicating a significant conversion of a low value material to
highly protein contained animal feed and this transformation
was crucial in providing an alternative solution for animal feed
An efficient identity-based group signature scheme over elliptic curves
Group signatures allow every authorized member of a group to sign on behalf of the underlying group. Anyone except the group manager is not able to validate who generates a signature for a document. A new identity-based group signature scheme is proposed in this paper. This scheme makes use of a bilinear function derived from Weil pairings over elliptic curves. Also, in the underlying composition of group signatures there is no exponentiation computation modulo a large composite number. Due to these ingredients of the novel group signatures, the proposed scheme is efficient with respect to the computation cost in signing process. In addition, this paper comes up with a security proof against adaptive forgeability
Smooth Flow in Diamond: Atomistic Ductility and Electronic Conductivity
Diamond is the quintessential superhard material widely known for its stiff and brittle nature and large electronic band gap. In stark contrast to these established benchmarks, our first-principles studies unveil surprising intrinsic structural ductility and electronic conductivity in diamond under coexisting large shear and compressive strains. These complex loading conditions impede brittle fracture modes and promote atomistic ductility, triggering rare smooth plastic flow in the normally rigid diamond crystal. This extraordinary structural change induces a concomitant band gap closure, enabling smooth charge flow in deformation created conducting channels. These startling soft-and-conducting modes reveal unprecedented fundamental characteristics of diamond, with profound implications for elucidating and predicting diamond’s anomalous behaviors at extreme conditions
First-principles Study of High-Pressure Phase Stability and Superconductivity of Bi4I4
Bismuth iodide Bi4I4 exhibits intricate crystal structures and topological insulating states that are highly susceptible to influence by environments, making its physical properties highly tunable by external conditions. In this work, we study the evolution of structural and electronic properties of Bi4I4 at high pressure using an advanced structure search method in conjunction with first-principles calculations. Our results indicate that the most stable ambient-pressure monoclinic α−Bi4I4 phase in C2/m symmetry transforms to a trigonal P31c structure (ɛ−Bi4I4) at 8.4 GPa, then to a tetragonal P4/mmm structure (ζ−Bi4I4) above 16.6 GPa. In contrast to the semiconducting nature of ambient-pressure Bi4I4, the two high-pressure phases are metallic, in agreement with reported electrical measurements. The ɛ−Bi4I4 phase exhibits distinct ionic states of Iδ− and (Bi4I3)δ + (δ=0.4123 e), driven by a pressure-induced volume reduction. We show that both ɛ- and ζ−Bi4I4 are superconductors, and the emergence of pressure-induced superconductivity might be intimately linked to the underlying structural phase transitions
A note on pentavalent s-transitive graphs
AbstractA graph, with a group G of its automorphisms, is said to be (G,s)-transitive if G is transitive on s-arcs but not on (s+1)-arcs of the graph. Let X be a connected (G,s)-transitive graph for some s≥1, and let Gv be the stabilizer of a vertex v∈V(X) in G. In this paper, we determine the structure of Gv when X has valency 5 and Gv is non-solvable. Together with the results of Zhou and Feng [J.-X. Zhou, Y.-Q. Feng, On symmetric graphs of valency five, Discrete Math. 310 (2010) 1725–1732], the structure of Gv is completely determined when X has valency 5. For valency 3 or 4, the structure of Gv is known
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