Taxol-DNA interactions: fluorescence and CD studies of DNA groove binding properties of taxol

Taxol is perhaps the most successful drug used for the treatment of various cancers. Comprehensive literature accumulated on therapeutics of the drug has indicated numerous side effects. In this paper, by use of fluorescence spectroscopy, it is shown that taxol binds to DNA with an affinity constant (Ka) of 1.08×107 M-1. This binding is accompanied by a large 'red edge excitation shift' (REES) of fluorescence emission maximum in taxol-DNA complex. The results point to an interaction of taxol with its core eight-membered ring in the DNA groove and the three phenyl rings projecting away from the DNA. The drug encompasses about two base pairs of DNA upon binding to it. Systematic studies with taxol analogues confirms such a mode of binding. These interesting findings on hitherto unknown taxol-DNA interactions may have clinical implications in view of its large number of side effects and pharmacokinetics

Web-Weka1.0: Online Tool for Comparison of Classification Algorithms of Weka

ABSTRACT Machine learning and Data mining are becoming increasingly important in the recent years and have been successfully applied to solve a number of problems, especially in the areas of science and engineering. A variety of algorithms exist in the popular data mining tool 'Weka' to classify a given set of records into different classes. However, choosing the right classifier among them is a tricky task as the performance of a particular algorithm depends on various factors such as the application domain and the data set. In order to aid the researchers in comparing the performances of various classification algorithms in Weka, we have developed an online resource named Web-Weka using which one can compare a set of classification algorithms on a single data set on the fly and choose the right classifier for their study. The tool is available for free at www.mcr.org.in/webweka

An index based road feature extraction from LANDSAT-8 OLI images

Road feature extraction from the remote sensing images is an arduous task and has a significant role in various applications of urban planning, updating the maps, traffic management, etc. In this paper, a new band combination (B652) to form a road index (RI) from OLI multispectral bands based on the spectral reflectance of asphalt, is presented for road feature extraction. The B652 is converted to road index by normalization. The morphological operators (top-hat or bottom-hat) uses on RI to enhance the roads. To sharpen the edges and for better discrimination of features, shock square filter (SSF), is proposed. Then, an iterative adaptive threshold (IAT) based online search with variational min-max and Markov random fields (MRF) model are used on the SSF image to segment the roads and non-roads. The roads are extracting by using the rules based on the connected component analysis. IAT and MRF model segmentation methods prove the proposed index (RI) able to extract road features productively. The proposed methodology is a combination of saturation based adaptive thresholding and morphology (SATM), and saturation based MRF (SMRF), applied to OLI images of several urban cities of India, producing the satisfactory results. The experimental results with the quantitative analysis presented in the paper

PAN SHARPENING USING RELATIVE SPECTRAL RESPONSE OF SENSOR FOR CARTOSAT-1 PAN AND RESOURCESAT LISS-4 MX DATA

Most of the Indian remote sensing systems, provide sensors with one high spatial resolution panchromatic (PAN) and several multispectral (MS) bands. An increasing number of applications, such as feature detection, change monitoring, and land cover classification, often demand the use of images with both high spatial and high spectral resolution. Image fusion or pan sharpening, is a technique to enhance the spatial resolution. The most significant problem in the traditional fusion methods is spectral distortion of fused images. The main reason for this being, the physical spectral characteristic of the sensors are not considered during the fusion process, resulting in undesirable effects such as modified spectral signatures resulting in classification errors and resolution over injection. For most earth resource satellites which provide both PAN and MS bands, in ideal condition, all MS bands would be well separated and would cover exactly the same wavelengths as the PAN band. Theoretically, the measured energy in the PAN band can be obtained with the summation of corresponding MS bands. As the measured energy in an individual channel is the sum of incoming radiation and relative spectral response: Lk&thinsp;=&thinsp;L(&lambda;)&thinsp;Rk(&lambda;); where &lambda; is the wavelength, the in-band radiance, L(&lambda;) at aperture spectral radiance and Rk(&lambda;) the peak-normalized spectral response. Therefore, the energy in PAN band can be estimated by defining weights as follows: Pan&thinsp;=&thinsp;wR&thinsp;R&thinsp;+&thinsp;wG&thinsp;G&thinsp;+&thinsp;wNIR NIR&thinsp;+ other; where Pan, G, R, NIR represent the radiance of individual spectral bands wG, wR, wNIR are the weights of corresponding MS bands and other for the influence of the spectral range which is missing from MS bands but still covered with the PAN band. In this paper, a novel spectral preservation fusion method for remotely sensed images using Cartosat-1 PAN and Resourcesat-Liss4 Mx data is presented by considering the physical characteristics of the sensors. It is based on the curvelet transform using relative spectral response (RSR) values of the sensor, improved in two parts: 1) the construction of PAN image using RSR values and the curvelet components, 2) the injection method of detail information. The performance and efficiency of the proposed method is compared with traditional IHS, wavelet based methods both visually and quantitatively. The results show that the proposed method preserves spatial details and minimize spectral distortion.</p

ESTABLISHMENT OF VICARIOUS CALIBRATION/VALIDATION FACILITY FOR SPACE BORNE HIGH AND MID RESOLUTION OPTICAL SENSORS

Vicarious calibration refers to methods that make use of “invariant” natural targets of the Earth for the post-launch calibration of sensors. This process of calibration is useful for initial phase orbit operation of sensor and thereafter for validation during its operational span. This method of periodic evaluation of radiometric and geometric performance of the space-borne optical sensors and validation of derived radiance/reflectance is to ensure availability of consistent and accurate data products to the user community. This paper describes one such Cal/Val facility’s design, engineering aspects and realization at National Remote Sensing Centre (NRSC), Shadnagar. The target materials used for filling the Cal/Val site are studied for its reflectance. These targets have reflectance ranging from 9% to 53%, in the VNIR (Visible and Near Infra-Red) region. This paper also describes instruments used for calibration and homogeneity studies of targets for its invariance since operationalisation (January 2016). The last section of this paper is about reflectance based absolute radiometric calibration of medium resolution Indian Remote Sensing (IRS) sensor (Resourcesat and Cartosat series) using RT model and edge based LSF/MTF estimation of high resolution sensor carried out using the Cal/Val facility

Heavy metals concentration in soils under rainfed agro-ecosystems and their relationship with soil properties and management practices

Heavy metals are governed by parent material of soils and influenced by the soil physicochemical properties and soil and crop management practices. This paper evaluates total heavy metal concentrations in rainfed soils under diverse management practices of tropical India. Vertisols (clayey soils with high shrink/swell capacity) had the highest concentrations of heavy metals. However, chromium (Cr) content was above the threshold value in Aridisol [calcium carbonate (CaCO3)]-containing soils of the arid environments with subsurface horizon development. Concentration increased at lower depths (>30 cm). Basaltic soils showed higher concentrations of nickel (Ni), copper (Cu) and manganese (Mn). Cadmium (Cd), cobalt (Co), Cu and Mn concentrations were higher in soils cultivated to cotton, whereas Cr concentration was above the threshold level of 110 mg kg−1 in food crop cultivated soils. As the specific soil surface is closely related to clay content and clay type, soil’s ability to retain heavy metals is more closely tied to the specific surface than to the soil cation exchange capacity. Higher positive correlations were found between heavy metal concentrations and clay content [Cd(r = 0.85; p ≤ 0.01); Co (r = 0.88; p ≤ 0.05); Ni (r = 0.87; p ≤ 0.01); Co (r = 0.81; p ≤ 0.05); Zn (r = 0.49; p ≤ 0.01); Cr (r = 0.80; p ≤ 0.05); Mn (r = 0.79; p ≤ 0.01)]. The amounts of nitrogen–phosphorus–potassium applied showed a positive correlation with Co and Ni (r = 0.62; p ≤ 0.05). As several soils used for growing food crops are high in Ni, Cr and Mn, the flow of these metals in soil–plant–livestock/human chain needs further attention

Generalized Kac-Moody Algebras from CHL dyons

We provide evidence for the existence of a family of generalized Kac-Moody(GKM) superalgebras, G_N, whose Weyl-Kac-Borcherds denominator formula gives rise to a genus-two modular form at level N, Delta_{k/2}(Z), for (N,k)=(1,10), (2,6), (3,4), and possibly (5,2). The square of the automorphic form is the modular transform of the generating function of the degeneracy of CHL dyons in asymmetric Z_N-orbifolds of the heterotic string compactified on T^6. The new generalized Kac-Moody superalgebras all arise as different `automorphic corrections' of the same Lie algebra and are closely related to a generalized Kac-Moody superalgebra constructed by Gritsenko and Nikulin. The automorphic forms, Delta_{k/2}(Z), arise as additive lifts of Jacobi forms of (integral) weight k/2 and index 1/2. We note that the orbifolding acts on the imaginary simple roots of the unorbifolded GKM superalgebra, G_1 leaving the real simple roots untouched. We anticipate that these superalgebras will play a role in understanding the `algebra of BPS states' in CHL compactifications.Comment: LaTeX, 35 pages; v2: improved referencing and discussion; typos corrected; v3 [substantial revision] 44 pages, modularity of additive lift proved, product representation of the forms also given; further references adde

The Murchison Widefield Array

It is shown that the excellent Murchison Radio-astronomy Observatory site allows the Murchison Widefield Array to employ a simple RFI blanking scheme and still calibrate visibilities and form images in the FM radio band. The techniques described are running autonomously in our calibration and imaging software, which is currently being used to process an FM-band survey of the entire southern sky.Comment: Accepted for publication in Proceedings of Science [PoS(RFI2010)016]. 6 pages and 3 figures. Presented at RFI2010, the Third Workshop on RFI Mitigation in Radio Astronomy, 29-31 March 2010, Groningen, The Netherland

Elevated Oestrogen Receptor Splice Variant ERαΔ5 Expression in Tumour-adjacent Hormone-responsive Tissue

Susceptibility to prostate or endometrial cancer is linked with obesity, a state of oestrogen excess. Oestrogen receptor (ER) splice variants may be responsible for the tissue-level of ER activity. Such micro-environmental regulation may modulate cancer initiation and/or progression mechanisms. Real-time reverse transcriptase (RT) polymerase chain reaction (PCR) was used to quantitatively assess the levels of four ER splice variants (ERαΔ3, ERαΔ5, ERβ2 and ERβ5), plus the full-length parent isoforms ERα and ERβ1, in high-risk [tumour-adjacent prostate (n = 10) or endometrial cancer (n = 9)] vs. low-risk [benign prostate (n = 12) or endometrium (n = 9)], as well as a comparison of UK (n = 12) vs. Indian (n = 15) benign prostate. All three tissue groups expressed the ER splice variants at similar levels, apart from ERαΔ5. This splice variant was markedly raised in all of the tumour-adjacent prostate samples compared to benign tissues. Immunofluorescence analysis for ERβ2 in prostate tissue demonstrated that such splice variants are present in comparable, if not greater, amounts as the parent full-length isoform. This small pilot study demonstrates the ubiquitous nature of ER splice variants in these tissue sites and suggests that ERαΔ5 may be involved in progression of prostate adenocarcinoma

Salmonella enterica Serovar Typhimurium Lacking hfq Gene Confers Protective Immunity against Murine Typhoid

Salmonella enterica is an important enteric pathogen and its various serovars are involved in causing both systemic and intestinal diseases in humans and domestic animals. The emergence of multidrug-resistant strains of Salmonella leading to increased morbidity and mortality has further complicated its management. Live attenuated vaccines have been proven superior over killed or subunit vaccines due to their ability to induce protective immunity. Of the various strategies used for the generation of live attenuated vaccine strains, focus has gradually shifted towards manipulation of virulence regulator genes. Hfq is a RNA chaperon which mediates the binding of small RNAs to the mRNA and assists in post-transcriptional gene regulation in bacteria. In this study, we evaluated the efficacy of the Salmonella Typhimurium Δhfq strain as a candidate for live oral vaccine in murine model of typhoid fever. Salmonella hfq deletion mutant is highly attenuated in cell culture and animal model implying a significant role of Hfq in bacterial virulence. Oral immunization with the Salmonella hfq deletion mutant efficiently protects mice against subsequent oral challenge with virulent strain of Salmonella Typhimurium. Moreover, protection was induced upon both multiple as well as single dose of immunizations. The vaccine strain appears to be safe for use in pregnant mice and the protection is mediated by the increase in the number of CD4+ T lymphocytes upon vaccination. The levels of serum IgG and secretory-IgA in intestinal washes specific to lipopolysaccharide and outer membrane protein were significantly increased upon vaccination. Furthermore, hfq deletion mutant showed enhanced antigen presentation by dendritic cells compared to the wild type strain. Taken together, the studies in murine immunization model suggest that the Salmonella hfq deletion mutant can be a novel live oral vaccine candidate