1,216 research outputs found

    On The Center Sets and Center Numbers of Some Graph Classes

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    For a set SS of vertices and the vertex vv in a connected graph GG, maxxSd(x,v)\displaystyle\max_{x \in S}d(x,v) is called the SS-eccentricity of vv in GG. The set of vertices with minimum SS-eccentricity is called the SS-center of GG. Any set AA of vertices of GG such that AA is an SS-center for some set SS of vertices of GG is called a center set. We identify the center sets of certain classes of graphs namely, Block graphs, Km,nK_{m,n}, KneK_n-e, wheel graphs, odd cycles and symmetric even graphs and enumerate them for many of these graph classes. We also introduce the concept of center number which is defined as the number of distinct center sets of a graph and determine the center number of some graph classes

    Effect of osmotic stress on in vitro plant growth hormone production by osmotolerant bacteria isolated from chilli phyto microbiome

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    The present study was conducted to determine the effect of osmotic stress on the plant growth hormone production by six osmotolerant plant growth promoting bacterial strains. These strains originated from the phytomicrobiome of chilli cultivated in the drought prone areas of Andhra Pradesh. They possessed multiple plant growth promotion traits including the ability to produce a variety of plant growth hormones. The effect of osmotic stress on the plant growth hormone production was determined by High Performance Liquid Chromatography (HPLC) under normal and in vitro osmotic stress conditions using 25% Poly Ethylene Glycol (PEG) 8000. In general, it was observed that osmotic stress impacted the plant growth hormone production of the isolates, but nevertheless plant hormones were detected in all the bacterial strains. An exception to this was the cytokinin molecule zeatin riboside, which was produced at higher levels by five of the six bacterial isolates under osmotic stressed conditions

    Current distribution of the invasive earthworm Pontoscolex corethrurus (Müller, 1857) after a century of its first report from Kerala state, India

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    Pontoscolex corethrurus (Müller, 1857) is an important peregrine earthworm species in the humid tropics and is found in land disturbed by human activities. Its presence in Kerala state was first reported by Michaelsen in 1910. So far the occurrence of 14 exotic earthworm species has been reported from Kerala state. However present distribution status of any of these exotic species is not yet thoroughly studied. Now P. corethrurus is naturalized in forests, degraded areas, and agroecosystems from the higher altitude areas to the coastal zones. Here, the current distribution pattern of P. corethrurus in the state after a period of 100 years is highlighted

    Development of a DNA marker by minisatellite associated sequence amplification (MASA) from the endangered Indian rhino (Rhinoceros unicornis)

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    Rhinoceroses are highly endangered species and their protection warrants immediate remedial measures. Development of DNA markers is envisaged to complement global efforts of the conservation of these extant animals. Minisatellite associated sequence amplification (MASA) of DNA from Indian rhinoceros (Rhinoceros unicornis) and three sub-species of South African black rhinoceros (Diceros bicornis) was carried out using a primer based on consensus sequence of the minisatellite repeat locus 33.15. Several bands in the range of 3.0 kilobases (kb) to 650 base pairs (bp) were identified that were useful for successful differentiation of R. unicornis from D. bicornis. Of these fragments, a 688 bp one, unique to R. unicornis was cloned and sequenced (Accession No. AF-296689). The band patterns uncovered by MASA and the species-specific hybridisation of pSG5 may be utilised as a tool for differentiating the R. unicornis genome from that of D. bicornis. This approach may also be adopted for the development of DNA-based genetic marker(s) useful for identification of other endangered species

    Green synthesis of magnesium oxide nanoparticles and their antibacterial activity

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    1210-1215Nanotechnology has prospects of opening new avenues to fight and prevent diseases using atomic-scale tailoring of materials. As the nano revolution emerges, it is imperative to develop “nano‑naturo” links between nanotechnology and green domains of the nature. The present investigation describes the mangrove Rhizophora lamarckii’s property of synthesizing magnesium oxide nanoparticles . The newly synthesized magnesium oxide nanoparticle morphology is nanohexagonal and spherical. The particles range in dimensions between 20 and 50 nm and are crystalline in nature. The functional groups of the mangrove, amine, and alkane are found to act as reductants and stabilizers. The newly synthesized MgO nanoparticles are found to have potent antibacterial activity

    Immunological mechanisms of intravesical chitosan/interleukin-12 immunotherapy against murine bladder cancer

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    There is a critical unmet clinical need for bladder cancer immunotherapies capable of inducing durable antitumor immunity. We have shown that four intravesical treatments with a simple co-formulation of interleukin-12 and the biopolymer chitosan not only destroy orthotopic bladder tumors, but also promote a potent long-lasting systemic immune response as evidenced through tumor-specific in vitro killing assays, complete protection from rechallenge, and abscopal antitumor responses at distant non-treated tumors. This study investigates the immunological kinetics underlying these results. We show through depletion studies that CD8+ T cells are required for initial tumor rejection, but CD4+ T cells protect against rechallenge. We also show that even a single intravesical treatment can eliminate tumors in 50% of mice with 6/9 and 7/8 mice eliminating tumors after three or four treatments respectively. We then performed immunophenotyping studies to analyze shifts in immune cell populations after each treatment within the tumor itself as well as in secondary lymphoid organs. These studies demonstrated an initial infiltration of macrophages and granulocytes followed by increased CD4+ and CD8+ effector-memory cells. This was coupled with a decreased level of regulatory T cells in peripheral lymph nodes as well as decreased myeloid-derived suppressor cell infiltration in the bladder. Taken together, these data demonstrate the ability of properly delivered interleukin-12-based therapies to engage adaptive immunity within the tumor itself as well as throughout the body and strengthen the case for clinical translation of chitosan/interleukin-12 as an intravesical treatment for bladder cancer

    PHARMACOGNOSTIC STUDY OF MANSOA ALLIACEA LEAF

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    Mansoa alliacea Lam. (Family: Bignoniaceae) is a native plant from Amazonian basin in South America. Plant derivatives are used as anti-inflammatory, antioxidant, antiseptic and antibacterial agents. The study was aimed to determine the pharmacognostic and phytochemicals present in Mansoa alliacea. Micro and organoleptic characteristics of fresh and dried leaf samples had been examined. Physicochemical variables had been done by using WHO suggested variables; preliminary phytochemical of leaf sample had been performed to identify the presence of alkaloids, flavonoids, tannins and phenols, and quinones using the ethanolic extract of the leaves of M. alliacea

    Modulation of Interleukin-12 activity in the presence of heparin

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    Glycosaminoglycans (GAGs), especially heparin and heparan sulfate (HS), modulate the functions of numerous cytokines. The aims of this multidisciplinary research were to characterize heparin binding to interleukin-12 (IL-12) and determine the mechanism(s) by which heparin influences IL-12 bioactivity. Heparin and HS were found to bind human IL-12 (hIL-12) with low micromolar affinity and increase hIL-12 bioactivity by more than 6-fold. Conversely, other GAGs did not demonstrate significant binding, nor did their addition affect hIL-12 bioactivity. Biophysical studies demonstrated that heparin induced only minor conformational changes while size-exclusion chromatography and small angle X-ray scattering studies indicated that heparin induced dimerization of hIL-12. Heparin modestly protected hIL-12 from proteolytic degradation, however, this was not a likely mechanism for increased cytokine activity in vitro. Flow cytometry studies revealed that heparin increased the amount of hIL-12 bound to cell surfaces. Heparin also facilitated hIL-12 binding and signaling in cells in which both hIL-12 receptor subunits were functionally deleted. Results of this study demonstrate a new role for heparin in modulating the biological activity of IL-12

    Orc1 Controls Centriole and Centrosome Copy Number in Human Cells

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    Centrosomes, each containing a pair of centrioles, organize microtubules in animal cells, particularly during mitosis. DNA and centrosomes are normally duplicated once before cell division to maintain optimal genome integrity. We report a new role for the Orc1 protein, a subunit of the origin recognition complex (ORC) that is a key component of the DNA replication licensing machinery, in controlling centriole and centrosome copy number in human cells, independent of its role in DNA replication. Cyclin A promotes Orc1 localization to centrosomes where Orc1 prevents Cyclin E-dependent reduplication of both centrioles and centrosomes in a single cell division cycle. The data suggest that Orc1 is a regulator of centriole and centrosome reduplication as well as the initiation of DNA replication

    A Retrospective Seroprevalence Study of Dengue, Chikungunya and Co-Infection virus: a Hospital Based Study from Theni, Tamil Nadu

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    Viral-borne diseases have recently gained significant public health importance in the current world. The Viral Research and Diagnostic Laboratory (VRDL) located at Government Theni Medical College (GTMC), Theni, Tamil Nadu, conducts the diagnosis of common virus infections. The purpose of this study is to investigate the seroprevalence of dengue (DENV) and chikungunya (CHIKV) virus infections, as well as their co-infection, in people who have clinical symptoms. From January 2018 to June 2023, serum samples were collected from clinically suspected patients at the tertiary care hospital in Theni, Tamil Nadu. DENV and CHIKV were detected using an enzyme-linked immunosorbent assay (ELISA) in all of the samples. A total of 16,997 cases were enrolled, out of which 11264/2971(26.3%) tested positive for Dengue IgM, 1395/288 (20.6%) for Dengue NS1 Ag, 19/3(15.7%) for IgG, followed by 4319/3388(8.9%) of CHIKV IgM. Fever (n = 16598, 97.6%) was the most prevalent clinical characteristic in all probable dengue and chikungunya patients. Other symptoms were chills (n = 11252, 66.1%), arthralgia (n = 10245, 60.2%), headache (n = 11354, 66.8%), and joint pain (n = 11256, 66.2%). The findings showed a lesser likelihood of acquiring both DENV and CHIKV infections at the same time; however, the risk is still not trivial. This study investigates the clinical presentation of Dengue-Chikungunya patients. The rising prevalence of dengue and chikungunya, as well as their co-infection, need thorough monitoring of endemic areas and good patient care management
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