Bemisia tabaci is a species complex consisting of at least 40 species which are morphologically indistinguishable. Althoughgenetic diversity of B. tabaci have been studied in many countries, its information is lack in Bangladesh. The COI sequencewas determined from 91 samples collected in Bangladesh and the phylogenetic relationship was constructed. Four crypticspecies (Asia I, Asia II-1, Asia II-5 and Asia II-10) were present in different regions. While both Asia I and Asia II-1was widely distributed in all around the country, Asia II-5 was central and southern regions, and Asia II-10 was onlyin the central region. Otherwise, our results showed that Asia II-5 had the highest haplotype and nucleotide diversity.Genetic groups of B. tabaci in Bangladesh were most similar with those of Thailand, Vietnam, Pakistan, China, and Indiabut did not show any aggressive cryptic species such as MED and MEAM-1.

We investigate two abnormal CME-Storm pairs that occurred on 2014 September 10 - 12 and 2015 March 15 - 17, respectively. The first one was a moderate geomagnetic storm (Dstmin  -75 nT) driven by the X1.6 high speed flare-associated CME (1267 km s−1) in AR 12158 (N14E02) near solar disk center. The other was a very intense geomagnetic storm (Dstmin  -223 nT) caused by a CME with moderate speed (719 km s−1) and associated with a filament eruption accompanied by a weak flare (C9.1) in AR 12297 (S17W38). Both CMEs have large direction parameters facing the Earth and southward magnetic field orientation in their solar source region. In this study, we inspect the structure of Interplanetary Flux Ropes (IFRs) at the Earth estimated by using the torus fitting technique assuming self-similar expansion. As results, we find that the moderate storm on 2014 September 12 was caused by small-scale southward magnetic fields in the sheath region ahead of the IFR. The Earth traversed the portion of the IFR where only the northward fields are observed. Meanwhile, in case of the 2015 March 17 storm, our IFR analysis revealed that the Earth passed the very portion where only the southward magnetic fields are observed throughout the passage. The resultant southward magnetic field with long- duration is the main cause of the intense storm. We suggest that 3D magnetic field geometry of an IFR at the IFR-Earth encounter is important and the strength of a geomagnetic storm is strongly affected by the relative location of the Earth with respect to the IFR structure.

The sweetpotato whitefly Bemisia tabaci (Gennadius) is a serious pest and vector of various virus causing economic losses in a variety of vegetables in Bangladesh as well as worldwide. In the present study, the mtCOI sequence of B. tabaci was analysed using 70 samples collected from different host plants at 12 districts of Bangladesh. Phylogenetic analysis was shown genetic divergence of our samples was 0.12 – 13.97%. There was three independent clusters such as Asia I, Asia II-1 and Asia II-5 genetic groups. Sequence diversity among three groups was 13.97%, 15.07% and 9.67%. Geographic diversity, for example, Asia I distributed in Central and Northern parts, Asia II-5 Central and Southern parts but Asia II-1 were present everywhere in Bangladesh. There was no B and Q aggressive biotypes in Bangladesh. Most Asia I and II was distributed in southeastern countries including Thailand, Vietnam, Pakistan, China and India. Our results provide understanding of genetic diversity of B. tabaci in southeast area.

La1-xBaxMnO3 (x = 0.30, 0.35 and 0.40) samples have been prepared by solid-state reaction method. The X-ray diffraction (XRD) study showed that all the samples crystallized in a rhombohedral structure with an R-3c space group. Variation of the magnetization as a function of the temperature and applied magnetic field was carried out. All the samples revealed ferromagnetic to paramagnetic (FM-PM) phase transition at the Curie temperature TC ~ 342 K. The magnetic entropy change was also studied through examination of the measured magnetic isotherms M(H, T) near TC. The magnetocaloric effect was calculated in terms of the isothermal magnetic entropy change. The maximum entropy change reaches a value of 1.192 J/ kgK under a magnetic field change of 2.5T for the La0.6Ba0.4MnO3 composition. The relative cooling power (RCP) is 79.31 J/ kg for the same applied magnetic field.