Convective thundercloud development over the western ghats mountain slope in Kerala

Studies were carried out on the data from Braemore mountain observatory (lat. 8°45'N, long. 77°5'E) using a single-lens ceilometer (LIDAR), an electric field mill and a portable automatic weather station throughout the year 2010. The simultaneous data collected using the above instruments indicate the existence of strong updrafts followed by the formation of thunderclouds, a characteristic of the mountain slopes, during the thunderstorm months. Changes in atmosphere related to condensation and formation of water droplets during updraft events on the mountain slope could be detected from the ceilometer scattering data. Results of the study point to the cause of relatively more thunderstorm activity in that zone. This seems to be due to excessive updraft, which is strongly related to lightning activity in the region

Fungal Endophyte Diversity in Sarracenia

Fungal endophytes were isolated from 4 species of the carnivorous pitcher plant genus Sarracenia: S. minor, S. oreophila, S. purpurea, and S. psittacina. Twelve taxa of fungi, 8 within the Ascomycota and 4 within the Basidiomycota, were identified based on PCR amplification and sequencing of the internal transcribed spacer sequences of nuclear ribosomal DNA (ITS rDNA) with taxonomic identity assigned using the NCBI nucleotide megablast search tool. Endophytes are known to produce a large number of metabolites, some of which may contribute to the protection and survival of the host. We speculate that endophyte-infected Sarracenia may benefit from their fungal associates by their influence on nutrient availability from within pitchers and, possibly, by directly influencing the biota within pitchers

The Cell Cycle Time of CD8+ T Cells Responding In Vivo Is Controlled by the Type of Antigenic Stimulus

A hallmark of cells comprising the mammalian adaptive immune system is the requirement for these rare naïve T (and B) lymphocytes directed to a specific microorganism to undergo proliferative expansion upon first encounter with this antigen. In the case of naïve CD8+ T cells the ability of these rare quiescent lymphocytes to rapidly activate and expand into effector T cells in numbers sufficient to control viral and certain bacterial infections can be essential for survival. In this report we examined the activation, cell cycle time and initial proliferative response of naïve murine CD8+ T cells responding in vivo to Influenza and Vaccinia virus infection or vaccination with viral antigens. Remarkably, we observed that CD8+ T cells could divide and proliferate with an initial cell division time of as short as 2 hours. The initial cell cycle time of responding CD8+ T cells is not fixed but is controlled by the antigenic stimulus provided by the APC in vivo. Initial cell cycle time influences the rate of T cell expansion and the numbers of effector T cells subsequently accumulating at the site of infection. The T cell cycle time varies with duration of the G1 phase of the cell cycle. The duration of G1 is inversely correlated with the phosphorylation state of the retinoblastoma (Rb) protein in the responding T cells. The implication of these findings for the development of adaptive immune responses and the regulation of cell cycle in higher eukaryotic cells is discussed

Transcriptional Activity and Nuclear Localization of Cabut, the Drosophila Ortholog of Vertebrate TGF-β-Inducible Early-Response Gene (TIEG) Proteins

BackgroundCabut (Cbt) is a C2H2-class zinc finger transcription factor involved in embryonic dorsal closure, epithelial regeneration and other developmental processes in Drosophila melanogaster. Cbt orthologs have been identified in other Drosophila species and insects as well as in vertebrates. Indeed, Cbt is the Drosophila ortholog of the group of vertebrate proteins encoded by the TGF-ß-inducible early-response genes (TIEGs), which belong to Sp1-like/Krüppel-like family of transcription factors. Several functional domains involved in transcriptional control and subcellular localization have been identified in the vertebrate TIEGs. However, little is known of whether these domains and functions are also conserved in the Cbt protein.Methodology/Principal FindingsTo determine the transcriptional regulatory activity of the Drosophila Cbt protein, we performed Gal4-based luciferase assays in S2 cells and showed that Cbt is a transcriptional repressor and able to regulate its own expression. Truncated forms of Cbt were then generated to identify its functional domains. This analysis revealed a sequence similar to the mSin3A-interacting repressor domain found in vertebrate TIEGs, although located in a different part of the Cbt protein. Using β-Galactosidase and eGFP fusion proteins, we also showed that Cbt contains the bipartite nuclear localization signal (NLS) previously identified in TIEG proteins, although it is non-functional in insect cells. Instead, a monopartite NLS, located at the amino terminus of the protein and conserved across insects, is functional in Drosophila S2 and Spodoptera exigua Sec301 cells. Last but not least, genetic interaction and immunohistochemical assays suggested that Cbt nuclear import is mediated by Importin-α2.Conclusions/SignificanceOur results constitute the first characterization of the molecular mechanisms of Cbt-mediated transcriptional control as well as of Cbt nuclear import, and demonstrate the existence of similarities and differences in both aspects of Cbt function between the insect and the vertebrate TIEG proteins

Molecular evolution of cyclin proteins in animals and fungi

<p>Abstract</p> <p>Background</p> <p>The passage through the cell cycle is controlled by complexes of cyclins, the regulatory units, with cyclin-dependent kinases, the catalytic units. It is also known that cyclins form several families, which differ considerably in primary structure from one eukaryotic organism to another. Despite these lines of evidence, the relationship between the evolution of cyclins and their function is an open issue. Here we present the results of our study on the molecular evolution of A-, B-, D-, E-type cyclin proteins in animals and fungi.</p> <p>Results</p> <p>We constructed phylogenetic trees for these proteins, their ancestral sequences and analyzed patterns of amino acid replacements. The analysis of infrequently fixed atypical amino acid replacements in cyclins evidenced that accelerated evolution proceeded predominantly during paralog duplication or after it in animals and fungi and that it was related to aromorphic changes in animals. It was shown also that evolutionary flexibility of cyclin function may be provided by consequential reorganization of regions on protein surface remote from CDK binding sites in animal and fungal cyclins and by functional differentiation of paralogous cyclins formed in animal evolution.</p> <p>Conclusions</p> <p>The results suggested that changes in the number and/or nature of cyclin-binding proteins may underlie the evolutionary role of the alterations in the molecular structure of cyclins and their involvement in diverse molecular-genetic events.</p

Expansion of Masood′s cytologic index for breast carcinoma and its validity

Background: The incidence of breast carcinoma is increasing in developing countries due to adoption of western life-style. Fine-needle aspiration cytology is the initial method to evaluate the palpable breast lesions. The neoadjuvant therapy is helpful in treating high grade rather than low grade breast carcinomas. Masood cytologic index (MCI) delineates all the breast lesions into four groups. The carcinoma group is not graded further. Aim: The present study proposes a method for the expansion of carcinoma group into three grades. Materials and Methods: A total of 50 breast carcinoma cases were prospectively studied by comparing expansion of MCI with modified bloom Richardson (MBR) grading over a period of 3 years. Results: Altogether 43/50 cases (86%) had concordance with histopathological grading. The analysis revealed a R2 value of 60%, which was significant. The P value of anisonucleosis, nucleoli and chromatin pattern were 0.001, 0.049 and 0.02 respectively, which were significant. Conclusions: The present study with the expansion of carcinoma category of MCI into three grades similar to MBR will help the treating surgeon to plan the management accordingly. The results obtained in this study need to be subjected to multicentric study with a large number of cases

Fatigue properties of sand cast, stircast and extruded Al-7Si-0.3 Mg alloy with trace additions of Be and Mn

Studies the fatigue behaviour of Al-7Si-0.3 Mg sand cast alloys at varying iron levels and with beryllium and manganese trace additions and when the alloy is stircast and extruded. From the stress (S)-number of cycles to failure (N)-(S-N) curves it is observed that the presence of higher amount of iron (0.76%) in sand cast alloys leads to a shorter fatigue life. Beryllium and manganese additions to a higher iron containing alloy (0.76%) show better fatigue properties than low (0.29%) and high (0.76%) iron containing sand cast alloys, thus countering the detrimental effect of iron. The better fatigue life of beryllium and manganese added high iron alloy is due to the presence of (Be,Mn)-Fe phases only inside α-Al dendrites. The fatigue life of stircast and extruded low iron (0.44%) alloy is superior to sand cast low (0.29%) iron alloys. Observation of fractured surfaces reveals that porosity/inclusions is the high stress concentrating point where the crack originates (stage-I) and then propagates (stage-II) depending on the presence of the second phases. In the case of low iron alloys (sand and extruded stircast) a crack propagates along eutectic silicon, while in the high iron alloys a crack propagates through the brittle β-phase. In beryllium and manganese added alloys, even though a crack nucleates on the (Be,Mn)-Fe phase, it will be arrested as it approaches α-Al dendrites and hence, the crack has to propagate along silicon particles. The fractured surface of the stircast and extruded alloys has revealed fine fatigue fracture with striation as compared to sand cast alloys. This aspect of crack nucleation and propagation is explained schematically