The Roles of Membrane Rafts in CD32A-Mediated Phagocytosis

Membrane rafts are highly dynamic heterogeneous sterol- and sphingolipid-rich micro-domains on cell surfaces. They are generally believed to provide residency for cell surface molecules (e.g., adhesion and signaling molecules) and scaffolding to facilitate the functions of these molecules such as membrane trafficking, receptor transport, cell signaling, and endocytosis.
The governing, or overall hypothesis, for this project is that membrane rafts provide residency for Fc[gamma]RIIA (CD32A) on K562 cells, and that by doing so they provide a platform from which Fc[gamma]RIIA initiate or carry out their functions, which include migration, signaling, phagocytic synapse formation, and internalization of IgG opsonized targets.
Using immuno-fluorescent laser scanning confocal microscopy and reflection interference microscopy (RIM), we studied the spatial and temporal distributions of membrane rafts and surface receptors, signaling molecules, and cell organelles during the formation of phagocytic contact areas. K562 cells, which naturally express CD32A, a cell surface receptor for the Fc portion of Immuno-globulin G(IgG), was chosen as a model for neutrophils. An opsonized target was modeled using a glass supported lipid bilayer reconstituted with IgG. CD32A was found to cluster and co-localize with membrane rafts. Placing the K562 cells on the lipid bilayer triggered a process of contact area formation that includes binding between receptors and ligands, their recruitment to the contact area, a concurrent membrane raft movement to and concentration in the contact area, and transport of CD32A, IgG, and membrane rafts to the Golgi complex. Characterization of these processes was performed using agents known to disrupt detergent resistant membranes (DRMs), dissolve actin microfilaments, and inhibit myosin motor activity, which abolished the CD32A clusters and prevented the contact area formation. 
The relevance to phagocytosis of contact area formation between K562 cells and lipid bilayers was demonstrated using micro-beads coated with a lipid bilayer reconstituted with IgG as the opsonized target instead of the glass supported planar lipid bilayer. Disruption of membrane rafts, salvation of the actin cytoskeleton, and inhibition of myosin II activity were found to inhibit phagocytosis.
These data suggest membrane rafts play several important roles in CD32A mediated phagocytosis including pre-clustering CD32A, transport of CD32A to the phagocytic cup, and transport of the opsonized target towards the Golgi complex. Here we have provided evidence that membrane rafts serve as platforms which are used to cluster CD32A and transport CD32A along the actin cytoskeleton to the site of phagocytic synapse formation thus allowing for the quick assembly of a phagocytic synapse.
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Host genetics and tuberculosis susceptibility

Susceptibility to tuberculosis is multifactorial. The importance of host genetic factors on the susceptibility or resistance to tuberculosis has been emphasized by many workers. Host genetic factors such as human leucocyte antigens (HLA) and non-HLA genes that are associated with the susceptibility to tuberculosis will serve as genetic markers to predispose or predetermine the development of the disease. Such markers may be useful to understand the immune mechanism of susceptibility or resistance to tuberculosis. Association of various HLA and non-HLA genes with susceptibility to tuberculosis in various ethnic population has been established. HLA studies carried out in the Asian region, especially in India, revealed the association of HLA-DR2 and -DQ1 antigens with the susceptibility to pulmonary TB. Further, studies on DNA typing explored the association of DRB1 *1501 and *1502 (DR2 subtypes) in north Indian and DRB1 *1501, DRB1 *0601 (DQ1 subtype) and DPB1 *02 (DP2 subtype) in south Indian population. Various studies on non-classical major histocompatibility complex (MHC) genes and non-MHC/non-HLA gene polymorphisms such as transporter associated with antigen processing (TAP), tumour necrosis factor a and b (TNF a and b), mannose binding lectin (MBL), vitamin D receptor (VDR) (BsmI, ApaI, TaqI and FokI polymorphisms), Interleukin-1 receptor antagonist (IL-1RA) and natural resistance associated macrophage protein-1 (NRAMP-1) genes revealed the association of TAP2 gene variant along with HLA–DR2 and functional mutant homozygotes (FMHs) of MBL with the susceptibility to pulmonary TB. The polymorphic BsmI, ApaI, TaqI and FokI gene variants of VDR showed differential susceptibility and resistance with male and female subjects. These studies suggest that multicandidate genes are associated with the susceptibility to pulmonary tuberculosis in India

Role of Human Leucocyte Antigen (HLA) and Non-HLA genes in susceptibility or resistance to pulmonary tuberculosis

Human beings live in an environment endemic to various diseases. Under such conditions, some individuals are susceptible to certain diseases while most are resistant to those diseases. This raises many questions. One such question is whether the person who is susceptible is genetically different from the person who is resistant to the disease? Similarly, in a family, one of the parents may be affected with a particular disease (e.g. diabetes); among the children born to the parents, if one child (younger one) develops the disease and the other child (elder one) does not, the question arises why did the younger one develop the disease and the elder did not, when both of them were living together with the affected parent. This raises the possibility of the disease being inherited from parents. If genetic factors play a major role in disease susceptibility or resistance, in what way are they associated with the disease development? Do they control the immune response to an antigen and/or pathogen? Do they play a role in the immune mechanism of susceptibility or resistance to disease? This article gives an account of disease susceptibility or resistance in pulmonary tuberculosis in the context of the host genetic factors, i.e. HLA (Human Leucocyte Antigens) and non- HLA genes and their gene products

Enhancing the Photovoltaic Performance of Dye-Sensitised Solar Cells for Building Integrated Applications

The building sector is responsible for more than one-third of global energy consumption. With increasing global population, the demand for energy efficiency buildings and on-site electricity production is rising. Building integrated photovoltaics (BIPV) is one of the most promising contributors to net-zero energy buildings, while also increasing the aesthetic value of the built environment. Among all the transparent solar cells, dye-sensitised solar cells (DSSCs) have low production cost, semi-transparency nature and a range of colours for building design. This thesis presents an overview of the current energy scenario and future prospects, state-of-the-art of photovoltaic technologies and the challenges in commercialising new generation solar cells. The first approach here is to find an efficient and low-cost alternative photoanode, sensitiser and counter electrode for DSSC. The tested materials are high surface area mesoporous TiO2, new ruthenium complex (m-HRD-1) sensitiser and Jet nebulizer spray coated CZTS. All the obtained results are compared with the commercial materials. Secondly, semi-transparent DSSCs are fabricated with different transparencies and their colour properties such as correlated colour temperature and colour rendering index are evaluated. Moreover, glazing properties and daylight glare analysis are studied to assess the possibility of adopting semi-transparent DSSCs into building architectures. Finally, a low solar concentrator is placed on the transparent-DSSCs to enhance their photovoltaic performance. The internal charge transfer mechanism of the DSSCs is also studied to understand the impact of the concentrated light. Furthermore, the performance of the concentrator coupled devices under different light intensities is studied. The results presented here provide a fertile base for further investigation, which will focus on improving the performance of all the new generation low cost solar cells using optical elements with new designs. The target is to improve the performance and stability of the transparent solar cell devices and use them as BIPV materials to overcome the challenges of the increasing energy demand

Algorithm for Pocket Milling using Zig-zag Tool Path

Pocket-milling operations are widely used for scooping out materials during the machiningof aircraft components. This paper presents a tool-path planning algorithm for pocket-millingusing zig-zag method. The algorithm consists of basically three modules, viz., generating toolpathelements using pocket geometry entities as input, finding out intersection points (edgepoints), and rearranging points in a zig-zag fashion. OPTPATH algorithm1,2 is used for generatingtool-path elements. These elements thus generated are used to find out the intersection pointswith all entities. The valid points are arranged in a zig-zag way, which are used for machiningany pocket considered. This algorithm works satisfactorily for all the pocket boundaries havingline-line, line-arc, and arc-arc geometry entities

Training fisherwomen in fish processing

A project on training fisherwomen for their participation in rural development, sponsored by Ford Foundation (U.S.A), has been started by the Centre for Agricultural and Rural Development Studies, T.N AU.,at the Fisheries College, Tuticorin. The project alms to select a few literate rural women with leadership qualities for Imparting to them a training In the organisational and managerial aspects of a viable fish processing enterprise. It also alms to assist the trained fisherwomen in organising and operating cottage industries by continued technical backing and thus making the production units demonstration centres for the benefit of other women In the region. The preliminary survey helped in identifying 5 candidates from each of the 3 selected villages. The pre-survey revealed the respondents' choice of subject-areas to undergo training and their enthusiasm to learn techniques for the preparation of fish products like fish pickle and MasI Meen. It also revealed their desire to be exposed to new products like fish wafers, fish oil, fish meal, shark fin-rays etc. The pre- and post evaluations of the training programme helped In I) identifying training needs In the fields of marketing and financial management; II) Identifying some low-cost technological substitutes for some of the commercial products (eg: 'Gadi' for vineger); ill) identifying the products or techniques appreciated by the trainees and the products or techniques that received lukewarm response with reasons for such a response: Iv) Identifying the level of managerial efficiency gained by the trainees and the kind of support required for each Individual to start cottage industries. The programme Is being followed up by Interpersonal contacts and the co-ordinate efforts of the development departments

OPTIMIZATION OF SURFACE ROUGHNESS OF AISI 304 AUSTENITIC STAINLESS STEEL IN DRY TURNING OPERATION USING TAGUCHI DESIGN METHOD

The present work is concentrated with the dry turning of AISI 304 Austenitic Stainless Steel (ASS). This paper presents the influence of cutting parameters like cutting speed, feed rate and depth of cut on the surface roughness of austenitic stainless steel during dry turning. A plan of experiments based on Taguchi’s technique has been used to acquire the data. An orthogonal array, the signal to noise (S/N) ratio and the analysis of variance (ANOVA) are employed to investigate the cutting characteristics of AISI 304 austenitic stainless steel bars using TiC and TiCN coated tungsten carbide cutting tool. Finally the confirmation tests that have been carried out to compare the predicted values with the experimental values confirm its effectiveness in the analysis of surface roughness

Marine fisheries development in Tamil Nadu

Fisheries development is governed by the stock of fishery resources, the level and types of fishing effort and the use of diversified craft and gear. The growing Importance of fishery resources and the level of their exploitation are traced in this paper. The marine capture fisheries account for a substantial proportion of the total fish production in Tamil Nadu. The present level of fish landings, their seasonal variation and the major species groups are brought out. The developmental programme aimed at increasing fish production are reviewed. The need for innovations In and diversification of fishing methods is highlighted. The Impact of investment on fish production is analysed with a time frame of ten years. Basic needs of fisher folk which have a bearing on fisheries development are identified. Technological developments made over the last decade are mentioned with a note on the extent of non-adoption of new technology and the major determinants thereof are pointed out for remedying the situation. Culture practices in suitable areas along the coasts are stressed to provide employment opportunities that step up production. Developments in the preservation and processing of the sea foods are presented and the scope for the establishment of a stable Internal and external market is explored. The state of affairs of marine or coastal fisheries management and suggestions for toning up resource management are stressed. The need for sea ranching and SCUBA diving Is Indicated. The vital feature of training and the nature and areas of extension programmes are also pointed out for ushering In speedier development of the sector