Bacillus thuringiensis and its application in agriculture

Presently, a number of approaches to pest control via genetic engineering have been developed and genetically engineered crops expressing insecticidal characteristics are under cultivation for the last 15 years. Use of Bacillus thuringiensis genes encoding o̅ endotoxins with insecticidal characteristics is the major approach and a number of such B. thuringiensis genes have been expressed in crops with variable level of efficiency. It is very crucial to achieve adequate level of B. thuringiensis gene expression to have durable resistance against target insect pests. As with many aspects of genetic engineering, politics can impact on the success of a project involving the development of B. thuringiensis transgenic crops, irrespective of its apparent social, economic or environmental benefits. Public education will be essential to ensure the widespread adoption of genetic adoption technologies in agriculture, and scientists will have to play an active role in this process

Correlation of Atrial Fibrillation with Left Atrial Volume in Patients with Mitral Stenosis. a Single Centre Study From Pakistan

Background: Rheumatic heart disease has a strong association with mitral valve stenosis. Atrial fibrillation is one of the most common complications of this condition and is a poor prognostic factor. Early detection and prompt management of atrial fibrillation can help to improve the quality of life and increase the life expectancy of the patients. We carried out this study to investigate the significance of left atrial volumetric changes in mitral stenosis and its correlation with atrial fibrillation. Methodology: We audited the data of 60 patients of rheumatic heart disease who had mitral valve stenosis. The patients were randomized into atrial fibrillation (Group A) and normal sinus rhythm (Group B). We conducted this cross-sectional analytical study at Cardiology Department, Mayo Hospital, Lahore, from 1st February 2017 to 31st January 2018. We only included those patients who consented to be a part of this study and fulfilled our predefined inclusion criteria. Left atrial volume was measured by prolate ellipse method and biplane methods on echocardiography. The Data was analyzed on SPSS v20. Results: Sixty patients were included in the study. Among the subjects, thirty-six (60%) were males, and twenty-four (40%) were females. Atrial fibrillation was noted in 43.33% of the patients of mitral valve stenosis. There was a marked difference in the mean volume of the left atrium among the two groups. We observed that the mean area of the mitral valve for Group A patients was larger than that of patients in Group B. Our study showed an inverse correlation between left atrial volume and mitral valve area among Group A patients. Conclusion: Patients of mitral stenosis are at an increased risk of developing atrial fibrillation if the left atrial volume is increasing. All patients with mitral stenosis should have routine echocardiography & measurement of left atrial volumes, so that proper treatment can be started if the left atrial volume is increasing, to prevent atrial fibrillation

Optimization of callus induction and regeneration system for Pakistani wheat cultivars Kohsar and Khyber-87

Wheat is a member of family Poaceae. It is the major staple food of Pakistan. The present study was done to improve the regeneration of two commercially grown wheat varieties Kohsar and Khyber-87.Mature embryos were used as explants. Five different concentrations of 2,4-D; 2, 2.5, 3, 3.5 and 4 mg/L were used for callus induction. For regeneration, initially different concentrations (0.1 to 0.2) of IAA(indole-3-acetic acid) and BAP (6-benzylaminopurine) were experimented. The best combination of these hormones that is, 0.1 mg/L IAA and 0.5 mg/L BAP were further subjected to experimentation along with different concentrations of kinetin; 0.1, 0.2, 0.3, 0.4, 0.5 and 1 mg/L. Maximum calli of Kohsar (83.3%) was obtained at 3 mg/L 2,4-D whereas for Khyber-87 maximum callus induction (71.70%) was obtained at 3.5 mg/l 2,4-D. The maximum regeneration of both Kohsar and Khyber-87 (80.5 and 62.2%, respectively) were obtained at the combinations of 0.1 mg/L IAA, 0.5 mg/L BAP and 0.5 mg/L kinetin

Fishermen's ingenuity in utilizing thermocole for making fishing crafts at Satpati (Maharashtra)

The ingenious traditional fishers of Satpati(Maharashtra) designed and fabricated fishing crafts uusing cheap thermocole(polyurethene)

Development of male sterility by silencing Bcp1 gene of Arabidopsis through RNA interference

The development of male sterility is one of the most important steps in hybrid seed production. Several methods for the abortion of pollens based on conventional as well as genetic engineering are reported for the various crop species. Here we have investigated the use of RNA interference (RNAi) technology to silence a male specific gene, Bcp1 in the model host Arabidopsis thaliana. Bcp1 is active in both diploid tapetum and haploid microspores. Three batches of explants (A. thaliana) were selected onherbicide glufosinate ammonium and putative transgenes were confirmed through PCR and Southern hybridization. About 49 out of 58 Arabidopsis lines transformed with RNAi construct containing Bcp1 sequences were male sterile. Transgenic plants were phenotypically indistinguishable from nontransgenic plants and by crossing with non-transgenic fertile pollens successful seed set was observed. The Bcp1 gene was also amplified from chilies, tomato and brassica. The present study resulted in developing male sterile A. thaliana (Eco. Columbia) line through genetic engineering. The diversity of Bcp1 gene will help us to produce transgenic male sterile plants in crop plants

Long-lasting photoluminescence in freestanding GaN templates

We studied time-resolvedphotoluminescence(PL) over a temporal range 10−6–103 s in high-purity freestanding GaN templates. Red, yellow, green, blue, and shallow donor–acceptor emission bands can be resolved in the PLspectrum. Observation of luminescence long after the excitation is switched off is a striking feature of our study. The persistent PL observed for all above bands, except for the green band, is primarily attributed to the donor–acceptor-pair-type recombination. An unusually slow, nonexponential decay of radiative transitions from the conduction band to the shallow acceptor was also observed, pointing to some additional mechanism for the persistent PL. Possible role of the surface states in this effect is discussed

Block-classified bidirectional motion compensation scheme for wavelet-decomposed digital video

In this paper the authors introduce a block-classified bidirectional motion compensation scheme for the previously developed wavelet-based video codec, where multiresolution motion estimation is performed in the wavelet domain. The frame classification structure described in this paper is similar to that used in the MPEG standard. Specifically, the I-frames are intraframe coded, the P-frames are interpolated from a previous I- or a P-frame, and the B-frames are bidirectional interpolated frames. They apply this frame classification structure to the wavelet domain with variable block sizes and multiresolution representation. They use a symmetric bidirectional scheme for the B-frames and classify the motion blocks as intraframe, compensated either from the preceding or the following frame, or bidirectional (i.e., compensated based on which type yields the minimum energy). They also introduce the concept of F-frames, which are analogous to P-frames but are predicted from the following frame only. This improves the overall quality of the reconstruction in a group of pictures (GOP) but at the expense of extra buffering. They also study the effect of quantization of the I-frames on the reconstruction of a GOP, and they provide intuitive explanation for the results. In addition, the authors study a variety of wavelet filter-banks to be used in a multiresolution motion-compensated hierarchical video codec

In vitro regeneration of Pakistani peanut (Arachis hypogea L.) varieties using de-embryonated coteledonary explants

Peanut (Arachis hypogaea L.) belongs to the family leguminosae and is one of the world’s largest oilseed crops. This study is the first report on peanut regeneration from Pakistan using four commercially released peanut varieties, that is, Golden, BARI-2000, BARD-479 and BARD-92. Longitudinally, halved cotyledons with removed embryos were employed as explants. Among various tested combinations of BAP and NAA, the best combination was 4 and 0.1 mg/L respectively. BARI-2000 proved to be the best responsive variety for in vitro regeneration in terms of number of shoots/explant (133.3%) and number of rooted plants/explant (124.99%). The optimized protocol, which is the first one in the country, would be used to incorporate important traits in future breeding programmes of peanut in Pakistan.Key words: Arachis hypogea, de-embryonated cotyledons, BAP, NAA, in vitro regeneration, Pakistan

The cross-species immunity during acute Babesia co-infection in mice

Babesiosis causes high morbidity and mortality in immunocompromised individuals. An earlier study suggested that lethal Babesia rodhaini infection in murine can be evaded by Babesia microti primary infection via activated macrophage-based immune response during the chronic stage of infection. However, whether the same immune dynamics occur during acute B. microti co-infection is not known. Hence, we used the mouse model to investigate the host immunity during simultaneous acute disease caused by two Babesia species of different pathogenicity. Results showed that B. microti primary infection attenuated parasitemia and conferred immunity in challenge-infected mice as early as day 4 post-primary infection. Likewise, acute Babesia co-infection undermined the splenic immune response, characterized by the significant decrease in splenic B and T cells leading to the reduction in antibody levels and decline in humoral immunity. Interestingly, increased macrophage and natural killer splenic cell populations were observed, depicting their subtle role in the protection. Pro-inflammatory cytokines (i.e. IFN-γ, TNF-α) were downregulated, while the anti-inflammatory cytokine IL-10 was upregulated in mouse sera during the acute phase of Babesia co-infection. Herein, the major cytokines implicated in the lethality caused by B. rodhaini infection were IFN- γ and IL-10. Surprisingly, significant differences in the levels of serum IFN- γ and IL-10 between co-infected survival groups (day 4 and 6 challenge) indicated that even a two-day delay in challenge infection was crucial for the resulting pathology. Additionally, oxidative stress in the form of reactive oxygen species contributed to the severity of pathology during acute babesiosis. Histopathological examination of the spleen showed that the erosion of the marginal zone was more pronounced during B. rodhaini infection, while the loss of cellularity of the marginal zone was less evident during co-infection. Future research warrants investigation of the roles of various immune cell subtypes in the mechanism involved in the protection of Babesia co-infected hosts