Species groups among pelagic tunicates in the western part of the Bay of Bengal

The tunicate species which frequently form part of each other's environment were assorted into groups by the use of an index derived from the corrected geometric mean of joint occurrence of pairs of species following Fager (1957) and Fager and McGowan (1963). The relationships shown in the temperature-salinity-plankton (TSP) diagrams between species and water properties are also used as a basis for classifying the species. Similar relationships have enabled species to be grouped together and consistent differences between one group and another set them apart

Residual tumor cells that drive disease relapse after chemotherapy do not have enhanced tumor initiating capacity.

Although chemotherapy is used to treat most advanced solid tumors, recurrent disease is still the major cause of cancer-related mortality. Cancer stem cells (CSCs) have been the focus of intense research in recent years because they provide a possible explanation for disease relapse. However, the precise role of CSCs in recurrent disease remains poorly understood and surprisingly little attention has been focused on studying the cells responsible for re-initiating tumor growth within the original host after chemotherapy treatment. We utilized both xenograft and genetically engineered mouse models of non-small cell lung cancer (NSCLC) to characterize the residual tumor cells that survive chemotherapy treatment and go on to cause tumor regrowth, which we refer to as tumor re-initiating cells (TRICs). We set out to determine whether TRICs display characteristics of CSCs, and whether assays used to define CSCs also provide an accurate readout of a cell's ability to cause tumor recurrence. We did not find consistent enrichment of CSC marker positive cells or enhanced tumor initiating potential in TRICs. However, TRICs from all models do appear to be in EMT, a state that has been linked to chemoresistance in numerous types of cancer. Thus, the standard CSC assays may not accurately reflect a cell's ability to drive disease recurrence

Integrin signaling is critical for pathological angiogenesis

The process of postnatal angiogenesis plays a crucial role in pathogenesis of numerous diseases, including but not limited to tumor growth/metastasis, diabetic retinopathy, and in tissue remodeling upon injury. However, the molecular events underlying this complex process are not well understood and numerous issues remain controversial, including the regulatory function of integrin receptors. To analyze the role of integrin phosphorylation and signaling in angiogenesis, we generated knock-in mice that express a mutant β3 integrin unable to undergo tyrosine phosphorylation. Two distinct models of pathological angiogenesis revealed that neovascularization is impaired in mutant β3 knock-in mice. In an ex vivo angiogenesis assay, mutant β3 knock-in endothelial cells did not form complete capillaries in response to vascular endothelial growth factor (VEGF) stimulation. At the cellular level, defective tyrosine phosphorylation in mutant β3 knock-in cells resulted in impaired adhesion, spreading, and migration of endothelial cells. At the molecular level, VEGF stimulated complex formation between VEGF receptor-2 and β3 integrin in wild-type but not in mutant β3 knock-in endothelial cells. Moreover, phosphorylation of VEGF receptor-2 was significantly reduced in cells expressing mutant β3 compared to wild type, leading to impaired integrin activation in these cells. These findings provide novel mechanistic insights into the role of integrin–VEGF axis in pathological angiogenesis

Preliminary observations on the hydrography and inshore plankton in the Bay of Bengal off Visakhapatnam coast

Plankton investigation in Indian waters is in its infancy and most of the observations so far made are confined to a narrow coastal belt of water not exceeding two to five miles width, the samples being collected by towing a net from country crafts like the catamaran. Sewell (1913) gave the earliest account of the plankton from the south-east zone of the Bay of Bengal, based on a large number of samples collected from R.I.M.S.S. " INVESTIGATOR " during the survey season 1910-12. He found that while in the northerly region of the zone under survey the plankton exhibited a regular banded arrangement, there was uniform distribution of the plankton in the southerly region. Other studies have so far been largely confined to the inshore waters. Menon (1931), Aiyar et al. (1936), and Rama Murthy (1953) studied the qualitative and quantitative aspects of the plankton off the coast of Madras City. Chacko (1950), Prasad et ah (1952) and Prasad (1954) have made preliminary investigations on the seasonal variations and distribution of the plankton in the Gulf of Mannar. Ganapati and Murthy (1953) made a preliminary survey of the quantitative variations of the phytoplankton at various depths and distances in the neritic waters off Visakhapatnam. In addition to these general investigations accounts of special groups of planktonic organisms from the Bay of Bengal are also available

Development of a web-based simulation application for efficient drip irrigation submain design

Drip simulation software is essential for accurately optimizing and maximizing the efficiency of drip irrigation systems, enabling precise water management and resource conservation. The present study developed a powerful web-based application to assist irrigation system designers in evaluating the effectiveness of the submain design on uniform or non-uniform slope conditions. The software facilitates the simulation and optimisation of submain design by incorporating modern drip design approaches and state-of-the-art software development methodologies. With its intuitive user interface, the software allows users to effortlessly enter important design parameters, including slope specifications, lateral discharge rates, submain length, lateral spacing and submain inlet pressure head. The software calculates to determine the pressure head values at each outlet and the relative variation in pressure head (vh), allowing for comprehensive design evaluation. Extensive testing using various typical sample data ensured the high accuracy and reliability of the developed web application. It empowers users to explore multiple design alternatives and determine the most suitable option. Rigorous testing, employing various typical sample data, has further enhanced the accuracy and reliability of the developed application. Live demonstrations were conducted to evaluate its user-friendliness, yielding overwhelmingly positive feedback from designers. The software can be accessed conveniently via the website https://www.dripdesigncheck.in/telescopic/submain, ensuring easy availability to users

Neural stem cell properties of Müller glia in the mammalian retina: Regulation by Notch and Wnt signaling

AbstractThe retina in adult mammals, unlike those in lower vertebrates such as fish and amphibians, is not known to support neurogenesis. However, when injured, the adult mammalian retina displays neurogenic changes, raising the possibility that neurogenic potential may be evolutionarily conserved and could be exploited for regenerative therapy. Here, we show that Müller cells, when retrospectively enriched from the normal retina, like their radial glial counterparts in the central nervous system (CNS), display cardinal features of neural stem cells (NSCs), i.e., they self-renew and generate all three basic cell types of the CNS. In addition, they possess the potential to generate retinal neurons, both in vitro and in vivo. We also provide direct evidence, by transplanting prospectively enriched injury-activated Müller cells into normal eye, that Müller cells have neurogenic potential and can generate retinal neurons, confirming a hypothesis, first proposed in lower vertebrates. This potential is likely due to the NSC nature of Müller cells that remains dormant under the constraint of non-neurogenic environment of the adult normal retina. Additionally, we demonstrate that the mechanism of activating the dormant stem cell properties in Müller cells involves Wnt and Notch pathways. Together, these results identify Müller cells as latent NSCs in the mammalian retina and hence, may serve as a potential target for cellular manipulation for treating retinal degeneration

On the vertical distribution of chemical constituents in the shelf waters off Waltair

The chemical composition of the shelf water has been investigated and examples of the vertical chemical structure are given in the table. From these values and other related hydrographic information the chemical factors controlling the composition of the shelf water may be discussed. The range of salinity between surface and bottom was greater during the period of sinking and lower during upwelling. The high values of salinity, phosphate, silicates and oxygen were influenced by upwelling. The advection of Northern Dilute water and Southern Bay of Bengal water also affect the vertical and horizontal chemical structure of the water. These were further modified by planktonic consumption during periods of accelerated production. A detailed report is under preparation

The angiogenic response is dictated by β3 integrin on bone marrow–derived cells

Angiogenesis is dependent on the coordinated action of numerous cell types. A key adhesion molecule expressed by these cells is the αvβ3 integrin. Here, we show that although this receptor is present on most vascular and blood cells, the key regulatory function in tumor and wound angiogenesis is performed by β3 integrin on bone marrow–derived cells (BMDCs) recruited to sites of neovascularization. Using knockin mice expressing functionally stunted β3 integrin, we show that bone marrow transplantation rescues impaired angiogenesis in these mice by normalizing BMDC recruitment. We demonstrate that αvβ3 integrin enhances BMDC recruitment and retention at angiogenic sites by mediating cellular adhesion and transmigration of BMDCs through the endothelial monolayer but not their release from the bone niche. Thus, β3 integrin has the potential to control processes such as tumor growth and wound healing by regulating BMDC recruitment to sites undergoing pathological and adaptive angiogenesis

Systematics of the magnetic-Prandtl-number dependence of homogeneous, isotropic magnetohydrodynamic turbulence

We present the results of our detailed pseudospectral direct numerical simulation (DNS) studies, with up to $1024^3$ collocation points, of incompressible, magnetohydrodynamic (MHD) turbulence in three dimensions, without a mean magnetic field. Our study concentrates on the dependence of various statistical properties of both decaying and statistically steady MHD turbulence on the magnetic Prandtl number ${\rm Pr_M}$ over a large range, namely, $0.01 \leq {\rm Pr_M} \leq 10$. We obtain data for a wide variety of statistical measures such as probability distribution functions (PDFs) of moduli of the vorticity and current density, the energy dissipation rates, and velocity and magnetic-field increments, energy and other spectra, velocity and magnetic-field structure functions, which we use to characterise intermittency, isosurfaces of quantities such as the moduli of the vorticity and current, and joint PDFs such as those of fluid and magnetic dissipation rates. Our systematic study uncovers interesting results that have not been noted hitherto. In particular, we find a crossover from larger intermittency in the magnetic field than in the velocity field, at large ${\rm Pr_M}$, to smaller intermittency in the magnetic field than in the velocity field, at low ${\rm Pr_M}$. Furthermore, a comparison of our results for decaying MHD turbulence and its forced, statistically steady analogue suggests that we have strong universality in the sense that, for a fixed value of ${\rm Pr_M}$, multiscaling exponent ratios agree, at least within our errorbars, for both decaying and statistically steady homogeneous, isotropic MHD turbulence.Comment: 49 pages,33 figure