4,634 research outputs found
Efficacy of Methyl-eugenol as Male Attractant for Dacus dorsalis Hendel (Diptera: Tephritidae)
Dacus dorsalis Hendel is the predominant species of fruit-fly (99.8%) found in a carambola orchard.
Population level was found to be correlated (r = 0.56) with rainfall. Infestation of fruits began 29 days
after fruit set. Laboratory studies show that among the three species of fruitflies tested for attractiveness to
methyl eugenol, male of D. dorsalis and D. umbrosus showed no significant difference but both are significantly
different (p < 0.05) with D. cucurbitae. Virgin adult males of D. dorsalis more than 20 days old were
greatly attracted to methyl eugeno
Variation in relapse frequency and the transmission potential of Plasmodium vivax malaria
There is substantial variation in the relapse frequency of
Plasmodium vivax malaria, with fast-relapsing strains in
tropical areas, and slow-relapsing strains in temperate areas
with seasonal transmission. We hypothesize that much of the
phenotypic diversity in P. vivax relapses arises from selection
of relapse frequency to optimize transmission potential in a
given environment, in a process similar to the virulence
trade-off hypothesis. We develop mathematical models of P. vivax
transmission and calculate the basic reproduction number R0 to
investigate how transmission potential varies with relapse
frequency and seasonality. In tropical zones with year-round
transmission, transmission potential is optimized at
intermediate relapse frequencies of two to three months:
slower-relapsing strains increase the opportunity for onward
transmission to mosquitoes, but also increase the risk of being
outcompeted by faster-relapsing strains. Seasonality is an
important driver of relapse frequency for temperate strains,
with the time to first relapse predicted to be six to nine
months, coinciding with the duration between seasonal
transmission peaks. We predict that there is a threshold degree
of seasonality, below which fast-relapsing tropical strains are
selected for, and above which slow-relapsing temperate strains
dominate, providing an explanation for the observed global
distribution of relapse phenotypes
Non-agricultural Market Access: A South Asian Perspective
A key element of the Doha Round of trade negotiations is liberalisation of trade in industrial products, commonly known as non-agricultural market access (NAMA). These negotiations are important for developing countries as these will determine the market access opportunities through which they can improve their growth prospects. This paper examines the key issues of NAMA from the South Asian perspective, outlines a negotiating strategy for increased market access, and spells out some policy implications.
Persistence of two genotypes of Neisseria gonorrhoeae during transmission.
Isolates of Neisseria gonorrhoeae were tested using a highly discriminatory typing method, opa typing, to examine the genetic diversity over a 2-year study period of isolates from all consecutive patients with gonorrhea attending the Genitourinary Medicine clinic in Sheffield, United Kingdom. Two opa genotypes were detected throughout the 2-year time period and comprised 41% of all strains tested. The persistence of two opa types was investigated further to determine the apparent genetic stability, by examining the ability of isolates to undergo intragenic and intergenic recombination and mutation in vitro. Intragenic recombination or mutation involving the opa genes of N. gonorrhoeae in the selected isolates was not detected, but intergenic recombination did occur. opa genes of N. gonorrhoeae in vivo appear to diversify primarily through intergenic recombination. Intergenic recombination in vivo would require the presence of a mixed gonococcal infection, in which an individual is concurrently colonized with more than one strain of N. gonorrhoeae. We propose that the level of diversity of opa genotypes in a population is linked to the degree of sexual mixing of individuals and the incidence of mixed infections of N. gonorrhoeae
Influences Of Neodymium Magnet Configurations On The Stiffness Of A Vibration Based Energy Harvesting Device
Energy harvesting from ambient sources has been a very familiar concept in recent years. In vibration based energy harvesting, resonant linear generators have been the most commonly adopted solution in the harvesting devices. However, several challenges appear when dealing with a linear resonant generator. Among the challenges are the effective power harvested by a linear generator is proportional to the cube of excitation frequency and the power is maximising for a narrow frequency bandwidth only. In this research, ocean wave motion vibration is selected as one of the low frequency sources and its frequency content is investigated. The frequency content is investigated by placing a shock and vibration recorder (MSR) at on-shore, near-shore and offshore at the east coast of Peninsular Malaysia. The measurement shows that the ocean motion vibration is distributed in the low frequency region. Thus, a device that can operate optimally with the low frequency-low amplitude input and has the ability to overcome the narrow frequency bandwidth is invented. Several magnet configurations are suggested to investigate the influences on the stiffness to the proposed design. In one proposed design, the stiffness behaviour of the system is studied by having two single magnets with similar poles (repulsive) and opposite poles (attractive) is placed oppositely. In the second proposed design considered, an oscillating single magnet is placed opposite to the double stationary magnets either attractive or repulsive modes. Another setting is obtained by having an oscillating magnet configured with the repulsive and attractive mode stationary magnets simultaneously. The stiffness of the configurations is related to the degree of non-linearity system. The non-linearity of the system can be adjusted by varying the magnets gap. The non-linear restoring force shows the influences of the linear stiffness and the non-linear stiffness of the system. In this thesis, the analytical solutions to estimate the characteristic behaviour of the magnet configurations are also studied. These proposed designs are then investigated with two main measurements. The quasi-static measurement is conducted to investigate the system stiffness and the dynamic measurement is conducted to investigate the characteristic of the response over a frequency range. It was found that the device is able to increase the frequency as well as amplifying the amplitude of the response. The result also shows that the effective configuration can be made by having the double stationary magnets compared to the single stationary magnet configuration
Membangun Interpersonal Skills Pustakawan Dalam Layanan Informasi Perpustakaan
Komunikasi merupakan sarana membangun hubungan dengan orang lain. Membangun hubungan yang baik dan pelayanan perpustakaan yang berkualitas berkaitan dengan kemampuan pustakawan dalam memberikan informasi kepada para pemustaka. Seorang pustakawan dalam memberikan layanan informasi membutuhkan keterampilan dan kemampuan sehingga layanan informasi berjalan secara sempurna dan maksimal. Bagaimana interpersonal skills pustakawan dalam memberikan informasi dalam layanan perpustakaan?. Kajian pustaka yang bersifat kualitatif dilakukan untuk menjawab permasalahan tersebut dengan menelaah buku atau tulisan dari berbagai bentuk yang ada kaitannya dengan interpersonal skills. Pemaparan hasil dilakukan secara deskriptif analisis. Interpersonal skills pustakawan mempengaruhi respon pemustaka terhadap pemanfaatan layanan informasi perpustakaan. Keterampilan pustakawan tersebut dielaborasi dalam tulisan ini. Kata Kunci: Interpersonal Skills, Layanan Informas
Use of Scrap Tyre as Lightweight Material In Civil Engineering Infrastructure Works
Load reduction effect of using lightweight material in new construction, expansion, rehabilitation or maintenance of infrastructure facilities provide advantages in term of reduction of total cost, construction time and maintenance work especially in soft ground areas
Civil Infrastructure in Land Development: The Sustainable And Environmental Challenges
Intensive housing and land development in Malaysia since the last decade has resulted in the depletion of suitable and cheap spot
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