In this paper,an improvement has been made to the approximation technique of a complex domain through the stair-step approach to have a considerable accuracy,minimize computational cost,and avoid the hardship of manua...In this paper,an improvement has been made to the approximation technique of a complex domain through the stair-step approach to have a considerable accuracy,minimize computational cost,and avoid the hardship of manual work.A novel stair-step representation algorithm is used in this regard,where the entire procedure is carried out through our developed MATLAB routine.Arakawa C-grid is used in our approximation with(1/120)°grid resolution.As a test case,the method is applied to approximate the domain covering the area between 15°-23°N latitudes and 85°-95°E longitudes in the Bay of Bengal.Along with the approximation of the land-sea interface,coastal stations are also identified.Approximated land-sea interfaces and coastal stations are found to be in good agreement with the actual ones based on the similarity index,overlap fraction,and extra fraction criteria.The method can be used for approximating an irregular geometric domain to employ the finite difference method in solving problems related to long waves.As a test case,shallow water equations in Cartesian coordinates are solved on the domain of interest for simulating water levels due to the nonlinear tide-surge interaction associated with the storms April 1991 and AILA,2009 along the coast of Bangladesh.The same input except for the discretized domain and bathymetry as that of Paul et al.(2016)is used in our simulation.The results are found to be in reasonable agreement with the observed data procured from Bangladesh Inland Water Transport Authority.展开更多
The second internal transcribed spacer (ITS2) of Culicoides arakawae was amp lified by PCR, cloned and sequenced. wDNAsis software was used to analyze the IT S2 sequences of C. arakawae , two other Culicoides species ...The second internal transcribed spacer (ITS2) of Culicoides arakawae was amp lified by PCR, cloned and sequenced. wDNAsis software was used to analyze the IT S2 sequences of C. arakawae , two other Culicoides species and three othe r species of mosquitos which were obtained from GenBank. The lengths of the ITS2 region of the three Culicoides species (C.arakawae, C.variipennis and C.imico la) ranged from 205 to 250 bp, while the ITS2 region of Aedes albopictus a nd Anopheles albimanus were 424 bp and 435 bp respectively. The G+C content of C.arakawae was the lowest (20 87%) among the species examined, while tha t of Aedes albopictus (56 35%) and Anopheles albimanus (56 13%) were t he highest. The composition of the ITS2 sequence was highly variable, and there we re no conserved regions with more than two bases in their sequences. The conserv ed loci appeared at positions 9, 113, 117, 134, 141, 164, 197, 212, 292 and 396 loci. After the ITS2 sequences of the three species of Culicoides were align ed, four conserved regions were observed. The highest genetic similarity existed bet ween C.arakawae and C.imicola (40 9%) and the least between C.arakawa e, Aedes albopictus and Anopheles albimanus (7 7%). Since the ITS2 provid es enough genetic markers it could be used as a target region to set up diagnost ic PCR assay for Culicoides .展开更多
This paper presents a new horizontal staggered grid (LE grid), which defines h at a gridpoint, and both u and v at the same mid-gridpoint along the x and y directions. A general method is used to deduce the dispersion...This paper presents a new horizontal staggered grid (LE grid), which defines h at a gridpoint, and both u and v at the same mid-gridpoint along the x and y directions. A general method is used to deduce the dispersion relationships of describing inertia gravity waves on LE grid and Arakawa A―E grids, which are then compared with the analytical solution (AS) in re- solved or under-resolved cases, using two-order central difference or four-order compact differ- ence scheme from the frequency and group velocity. Results show that in both resolved and under-resolved cases, no matter whether two-order central difference or four-order compact dif- ference scheme is used, the frequency and group velocity discrete errors on LE grid in describing inertia gravity waves are smaller than those of Arakawa A―E grids. At the same time, it is only on LE or Arakawa grid C that the employment of a compact difference scheme of higher difference precision can improve their accuracy in describing inertia gravity waves. However, as for the other four grids (Arakawa A,B,D and E), when the difference precision increases, the accuracy of simulating inertia gravity waves decreases.展开更多
文摘In this paper,an improvement has been made to the approximation technique of a complex domain through the stair-step approach to have a considerable accuracy,minimize computational cost,and avoid the hardship of manual work.A novel stair-step representation algorithm is used in this regard,where the entire procedure is carried out through our developed MATLAB routine.Arakawa C-grid is used in our approximation with(1/120)°grid resolution.As a test case,the method is applied to approximate the domain covering the area between 15°-23°N latitudes and 85°-95°E longitudes in the Bay of Bengal.Along with the approximation of the land-sea interface,coastal stations are also identified.Approximated land-sea interfaces and coastal stations are found to be in good agreement with the actual ones based on the similarity index,overlap fraction,and extra fraction criteria.The method can be used for approximating an irregular geometric domain to employ the finite difference method in solving problems related to long waves.As a test case,shallow water equations in Cartesian coordinates are solved on the domain of interest for simulating water levels due to the nonlinear tide-surge interaction associated with the storms April 1991 and AILA,2009 along the coast of Bangladesh.The same input except for the discretized domain and bathymetry as that of Paul et al.(2016)is used in our simulation.The results are found to be in reasonable agreement with the observed data procured from Bangladesh Inland Water Transport Authority.
文摘The second internal transcribed spacer (ITS2) of Culicoides arakawae was amp lified by PCR, cloned and sequenced. wDNAsis software was used to analyze the IT S2 sequences of C. arakawae , two other Culicoides species and three othe r species of mosquitos which were obtained from GenBank. The lengths of the ITS2 region of the three Culicoides species (C.arakawae, C.variipennis and C.imico la) ranged from 205 to 250 bp, while the ITS2 region of Aedes albopictus a nd Anopheles albimanus were 424 bp and 435 bp respectively. The G+C content of C.arakawae was the lowest (20 87%) among the species examined, while tha t of Aedes albopictus (56 35%) and Anopheles albimanus (56 13%) were t he highest. The composition of the ITS2 sequence was highly variable, and there we re no conserved regions with more than two bases in their sequences. The conserv ed loci appeared at positions 9, 113, 117, 134, 141, 164, 197, 212, 292 and 396 loci. After the ITS2 sequences of the three species of Culicoides were align ed, four conserved regions were observed. The highest genetic similarity existed bet ween C.arakawae and C.imicola (40 9%) and the least between C.arakawa e, Aedes albopictus and Anopheles albimanus (7 7%). Since the ITS2 provid es enough genetic markers it could be used as a target region to set up diagnost ic PCR assay for Culicoides .
文摘This paper presents a new horizontal staggered grid (LE grid), which defines h at a gridpoint, and both u and v at the same mid-gridpoint along the x and y directions. A general method is used to deduce the dispersion relationships of describing inertia gravity waves on LE grid and Arakawa A―E grids, which are then compared with the analytical solution (AS) in re- solved or under-resolved cases, using two-order central difference or four-order compact differ- ence scheme from the frequency and group velocity. Results show that in both resolved and under-resolved cases, no matter whether two-order central difference or four-order compact dif- ference scheme is used, the frequency and group velocity discrete errors on LE grid in describing inertia gravity waves are smaller than those of Arakawa A―E grids. At the same time, it is only on LE or Arakawa grid C that the employment of a compact difference scheme of higher difference precision can improve their accuracy in describing inertia gravity waves. However, as for the other four grids (Arakawa A,B,D and E), when the difference precision increases, the accuracy of simulating inertia gravity waves decreases.
