AN INVESTIGATION ON ADVANCED WELDING TECHNIQUES

This paper deals with advanced welding techniques with use of friction stir welding. This type of welding carried out by aluminium 6063 alloy practically. When compared to conventional welding techniques it is not possible to weld, such type of aluminium alloy, because of some limitations. Friction stir welding is one such non-melting joining technology that has produced structural joints superior to conventional arc welds in aluminium. Friction stir welding can be conducted on a milling machine. While doing the experiment with change in variation of rotational speed and feed rate, with that experiment we chose five trials. In between five trials, the trials from one to four gives as different types of welds obtained. At the end of fifth trial, successful weld was obtained with very good surface finish on both ends and better tensile strength at types of welds obtained. At the end of fifth trial , successful weld was obtained with very good surface finish on both ends and better tensile strength at 1400rpm and 22.4 mm/rev. Tests were also performed to determine the susceptibility of FSW aluminium 6063 alloy to corrosion. The various test performed on the welded specimen are as follows tensile test and microstructure study. During tensile test, the maximum tensile strength obtained from two specimens was approximately 75% of the parent metal. Whereas the microstructure analysis is carried out to decrease the flow of material and change in the microstructure and grain size of measurement. By using this factor we present the paper that FRICTION STIR WELDING as a advanced welding techniques

AN INVESTIGATION ON DESIGN AND DEVELOPMENT OF ARECANUT TREE CLIMBER

The people in rural areas of Karnataka and Kerala mainly depend on agriculture for their livelihood. The main crops grown are Arecanut and coconut. For harvesting the nuts, and for spraying and applying insecticides on the crown, skilled labourers have to climb manually up the tree. Such a process looks easy, in reality it is a laborious and dangerous task. It requires skill to climb a arecanut tree. Skilled arecanut tree climbers have become scarce and farmers are finding it difficult to harvest the nuts. There are many equipments/ machines in the market to help the farmers in this regard. But they are not successful as the input for them is muscular power of the labour and it requires a person to physically climb the tree. There is no 100% safe arecanut harvesting device currently in the market. There is a need to invent a machine to address both efficiency and safety. The design of the device has to be simple enough for villagers to operate, yet work efficiently to appeal to the majority. Here we are designing and fabricating motorized arecanut tree climber. The tree climber has a base on which the drive system is mounted. The power from the motor to the rollers is transmitted by using sprocket and chain drive. To obtain the required speed of the rollers a reduction gear box is used in between the motor and the rollers. The machine is placed around the tree and clamped to it using a swivel opening on one side of the base. Due to the weight of the motor, gear box and some extra mass concentrated on one end of the base the machine locks itself to the tree. Now the motor is switched ON to drive the rollers. When the rollers rotate gripping the tree, the whole setup is lifted along the length of the tree. After reaching the required height the motor is switched OFF. By having suitable auxiliary equipments for spraying pesticides, plucking the nuts on the setup and suitable controlling methods for those equipments the required job can be performed. Once the job is done the motor is made to rotate in the reverse direction to descend down the tree

Solvatochromism, aggregation and photochemical properties of Fullerenes, C<SUB>60</SUB> and C<SUB>70</SUB>, in solution

Fullerenes, C60 and C70, display interesting physicochemical properties in solutions, especially due to their unique chemical structures and their good electron accepting abilities. Solubility of fullerenes in different organic solvents and their unusual solvatochromic behavior, the ability of the fullerenes to form aggregates in solutions, and their electron transfer and charge transfer interactions with variety of electron donors, are the subjects of extensive research activities for more than one decade. Many research groups including ours have contributed substantially in the understanding of the solvatochromism, aggregation behavior, and the photoinduced electron transfer and charge transfer chemistry of fullerenes, in condensed phase. Present article is aimed to summarize the important results reported on the above aspects of fullerenes, subsequent to the earlier report from our group. (D.K. Palit and J.P. Mittal, Full. Sci. &amp; Tech. 3, 1995, 643-659)

Hydrophobicity Directed Chiral Self-Assembly and Aggregation-Induced Emission:Diacetylene-Cored Pseudopeptide Chiral Dopants

Here we delineate simple and tunable hydrophobically driven chiral functional assemblies of diacetylene cored pseudopeptides. These amino acid appended, rigid core dialkynes constitute promising chiral supramolecular building blocks for materials properties engineering. The chiral appended amino acid elements allow for simple tuning of solubility and interaction properties as well as governing chirality, while the central dialkyne core can impart hydrophobically driven assembly and Aggregation Induced Emission (AIE) properties. The self-assembly of these rod-like dialkynes can be regulated by tuning the solvent environment, with for example self-assembly into vesicles in acetonitrile and into helical organization with AIE in a H 2 O/DMSO mixture. Of additional high interest, these supramolecular materials, themselves devoid of liquid crystal (LC) properties, can induce chirality into non-chiral LC matrices with high helical twisting power. </p

The Anticancer Plant Triterpenoid, Avicin D, Regulates Glucocorticoid Receptor Signaling: Implications for Cellular Metabolism

Avicins, a family of apoptotic triterpene electrophiles, are known to regulate cellular metabolism and energy homeostasis, by targeting the mitochondria. Having evolved from “ancient hopanoids,” avicins bear a structural resemblance with glucocorticoids (GCs), which are the endogenous regulators of metabolism and energy balance. These structural and functional similarities prompted us to compare the mode of action of avicin D with dexamethasone (Dex), a prototypical GC. Using cold competition assay, we show that Avicin D competes with Dex for binding to the GC receptor (GR), leading to its nuclear translocation. In contrast to Dex, avicin-induced nuclear translocation of GR does not result in transcriptional activation of GC-dependent genes. Instead we observe a decrease in the expression of GC-dependent metabolic proteins such as PEPCK and FASN. However, like Dex, avicin D treatment does induce a transrepressive effect on the pro-inflammatory transcription factor NF-κB. While avicin's ability to inhibit NF-κB and its downstream targets appear to be GR-dependent, its pro-apoptotic effects were independent of GR expression. Using various deletion mutants of GR, we demonstrate the requirement of both the DNA and ligand binding domains of GR in mediating avicin D's transrepressive effects. Modeling of avicin-GR interaction revealed that avicin molecule binds only to the antagonist confirmation of GR. These findings suggest that avicin D has properties of being a selective GR modulator that separates transactivation from transrepression. Since the gene-activating properties of GR are mainly linked to its metabolic effects, and the negative interference with the activity of transcription factors to its anti-inflammatory and immune suppressive effects, the identification of such a dissociated GR ligand could have great potential for therapeutic use

A Role for IFITM Proteins in Restriction of Mycobacterium tuberculosis Infection

SummaryThe interferon (IFN)-induced transmembrane (IFITM) proteins are critical mediators of the host antiviral response. Here, we expand the role of IFITM proteins to host defense against intracellular bacterial infection by demonstrating that they restrict Mycobacterium tuberculosis (MTb) intracellular growth. Simultaneous knockdown of IFITM1, IFITM2, and IFITM3 by RNAi significantly enhances MTb growth in human monocytic and alveolar/epithelial cells, whereas individual overexpression of each IFITM impairs MTb growth in these cell types. Furthermore, MTb infection, Toll-like receptor 2 and 4 ligands, and several proinflammatory cytokines induce IFITM1–3 gene expression in human myeloid cells. We find that IFITM3 co-localizes with early and, in particular, late MTb phagosomes, and overexpression of IFITM3 enhances endosomal acidification in MTb-infected monocytic cells. These findings provide evidence that the antiviral IFITMs participate in the restriction of mycobacterial growth, and they implicate IFITM-mediated endosomal maturation in its antimycobacterial activity

Effects of temporal variation in temperature and density dependence on insect population dynamics

Understanding the effects of environmental variation on insect populations is important in light of predictions about increasing climatic variability. This paper uses the univoltine western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte) as a case study and employs deterministic and stochastic modeling to evaluate how insect population dynamics is shaped by density-dependent survival and annual variation in temperature, which are key in regulating insect populations. Field data showed that larval survival varied significantly between years but was constant for a range of densities. Survival dropped only beyond a threshold density, a feature resembling generalized Ricker functions used in modeling density-dependent survival due to scramble competition for resources. We used soil temperature data for 20 yr to model annual variation in developmental time and survival. The deterministic model, where the developmental time was same across years, showed that though survival was high and did not change for a range of densities (i.e., density-independent survival), predicted densities were large enough that strong density dependence could occur in the field (i.e., predicted densities fall in the region where survival drops sharply) and that populations could exhibit stable equilibrium, cycles, etc. Interestingly, populations with lower density-independent survival were less likely to produce stable equilibrium compared to populations with higher density-independent survival. We found that population densities were at stable equilibrium when both mean developmental time and fertility were relatively low or when developmental time and fertility were relatively high. This in turn implies that, in warmer regions, where mean developmental time will be lower, stability is more likely for insect populations with low fertility; species in warmer regions will experience cyclical and unstable dynamics when fertility is high. While increase in the mean developmental time reduces overall survival, increasing variation in developmental time could increase mean survival, a consequence of the Jensen’s inequality, since survival was a concave decreasing function of developmental time. Hence, both mean and variability in temperature affect the dynamics of insect populations. Finally, we found that stochastic variation in soil temperature produced large variation in predicted population densities that could potentially enhance or diminish the effect of density dependence

In search of the right literature search engine(s)

*Background*&#xd;&#xa;Collecting scientific publications related to a specific topic is crucial for different phases of research, health care and &#x2018;effective text mining&#x2019;. Available bio-literature search engines vary in their ability to scan different sections of articles, for the user-provided search terms and/or phrases. Since a thorough scientific analysis of all major bibliographic tools has not been done, their selection has often remained subjective. We have considered most of the existing bio-literature search engines (http://www.shodhaka.com/startbioinfo/LitSearch.html) and performed an extensive analysis of 18 literature search engines, over a period of about 3 years. Eight different topics were taken and about 50 searches were performed using the selected search engines. The relevance of retrieved citations was carefully assessed after every search, to estimate the citation retrieval efficiency. Different other features of the search tools were also compared using a semi-quantitative method.&#xd;&#xa;*Results*&#xd;&#xa;The study provides the first tangible comparative account of relative retrieval efficiency, input and output features, resource coverage and a few other utilities of the bio-literature search tools. The results show that using a single search tool can lead to loss of up to 75% relevant citations in some cases. Hence, use of multiple search tools is recommended. But, it would also not be practical to use all or too many search engines. The detailed observations made in the study can assist researchers and health professionals in making a more objective selection among the search engines. A corollary study revealed relative advantages and disadvantages of the full-text scanning tools.&#xd;&#xa;*Conclusion*&#xd;&#xa;While many studies have attempted to compare literature search engines, important questions remained unanswered till date. Following are some of those questions, along with answers provided by the current study:&#xd;&#xa;a)&#x9;Which tools should be used to get the maximum number of relevant citations with a reasonable effort? ANSWER: _Using PubMed, Scopus, Google Scholar and HighWire Press individually, and then compiling the hits into a union list is the best option. Citation-Compiler (http://www.shodhaka.com/compiler) can help to compile the results from each of the recommended tool._&#xd;&#xa;b)&#x9;What is the approximate percentage of relevant citations expected to be lost if only one search engine is used? ANSWER: _About 39% of the total relevant citations were lost in searches across 4 topics; 49% hits were lost while using PubMed or HighWire Press, while 37% and 20% loss was noticed while using Google Scholar and Scopus, respectively._ &#xd;&#xa;c)&#x9;Which full text search engines can be recommended in general? ANSWER: _HighWire Press and Google Scholar._&#xd;&#xa;d)&#x9;Among the mostly used search engines, which one can be recommended for best precision? ANSWER: _EBIMed._&#xd;&#xa;e)&#x9;Among the mostly used search engines, which one can be recommended for best recall? ANSWER: _Depending on the type of query used, best recall could be obtained by HighWire Press or Scopus.

Avicin D, a Plant Triterpenoid, Induces Cell Apoptosis by Recruitment of Fas and Downstream Signaling Molecules into Lipid Rafts

Avicins, a family of triterpene electrophiles originally identified as potent inhibitors of tumor cell growth, have been shown to be pleiotropic compounds that also possess antioxidant, anti-mutagenic, and anti-inflammatory activities. We previously showed that Jurkat cells, which express a high level of Fas, are very sensitive to treatment with avicins. Thus, we hypothesized that avicins may induce cell apoptosis by activation of the Fas pathway. By using a series of cell lines deficient in cell death receptors, we demonstrated that upon avicin D treatment, Fas translocates to the cholesterol- and sphingolipid-enriched membrane microdomains known as lipid rafts. In the lipid rafts, Fas interacts with Fas-associated death domain (FADD) and Caspase-8 to form death-inducing signaling complex (DISC) and thus mediates cell apoptosis. Interfering with lipid raft organization by using a cholesterol-depleting compound, methyl-β-cyclodextrin, not only prevents the clustering of Fas and its DISC complex but also reduces the sensitivity of the cells to avicin D. Avicin D activates Fas pathways independent of the association between extracellular Fas ligands and Fas receptors. A deficiency in Fas and its downstream signaling molecules leads to the resistance of the cells to avicin D treatment. Taken together, our results demonstrate that avicin D triggers the redistribution of Fas in the membrane lipid rafts, where Fas activates receptor-mediated cell death

Phyllosticta citricarpa and sister species of global importance to Citrus.

Several Phyllosticta species are known as pathogens of Citrus spp., and are responsible for various disease symptoms including leaf and fruit spots. One of the most important species is P. citricarpa, which causes a foliar and fruit disease called citrus black spot. The Phyllosticta species occurring on citrus can most effectively be distinguished from P. citricarpa by means of multilocus DNA sequence data. Recent studies also demonstrated P. citricarpa to be heterothallic, and reported successful mating in the laboratory. Since the domestication of citrus, different clones of P. citricarpa have escaped Asia to other continents via trade routes, with obvious disease management consequences. This pathogen profile represents a comprehensive literature review of this pathogen and allied taxa associated with citrus, focusing on identification, distribution, genomics, epidemiology and disease management. This review also considers the knowledge emerging from seven genomes of Phyllosticta spp., demonstrating unknown aspects of these species, including their mating behaviour.TaxonomyPhyllosticta citricarpa (McAlpine) Aa, 1973. Kingdom Fungi, Phylum Ascomycota, Class Dothideomycetes, Order Botryosphaeriales, Family Phyllostictaceae, Genus Phyllosticta, Species citricarpa.Host rangeConfirmed on more than 12 Citrus species, Phyllosticta citricarpa has only been found on plant species in the Rutaceae.Disease symptomsP. citricarpa causes diverse symptoms such as hard spot, virulent spot, false melanose and freckle spot on fruit, and necrotic lesions on leaves and twigs.Useful websitesDOE Joint Genome Institute MycoCosm portals for the Phyllosticta capitalensis (https://genome.jgi.doe.gov/Phycap1), P. citriasiana (https://genome.jgi.doe.gov/Phycit1), P. citribraziliensis (https://genome.jgi.doe.gov/Phcit1), P. citrichinaensis (https://genome.jgi.doe.gov/Phcitr1), P. citricarpa (https://genome.jgi.doe.gov/Phycitr1, https://genome.jgi.doe.gov/Phycpc1), P. paracitricarpa (https://genome.jgi.doe.gov/Phy27169) genomes. All available Phyllosticta genomes on MycoCosm can be viewed at https://genome.jgi.doe.gov/Phyllosticta