1,476 research outputs found

    Singlet Scalar Resonances and the Diphoton Excess

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    ATLAS and CMS recently released the first results of searches for diphoton resonances in 13 TeV data, revealing a modest excess at an invariant mass of approximately 750 GeV. We find that it is generically possible that a singlet scalar resonance is the origin of the excess while avoiding all other constraints. We highlight some of the implications of this model and how compatible it is with certain features of the experimental results. In particular, we find that the very large total width of the excess is difficult to explain with loop-level decays alone, pointing to other interesting bounds and signals if this feature of the data persists. Finally we comment on the robust Z-gamma signature that will always accompany the model we investigate

    Notched and Unnotched Fatigue Behavior of Angle-Ply Graphite/Epoxy Composites

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    The axial fatigue behavior of both notched and unnotched graphite/epoxy composites was studied. In unnotched studies, conducted on a 0/+ or - 30 3S AS/3501 laminate, S-N curves were determined for various stress ratios R using simply supported test specimens. Apparent fatigue limits in tension-tension (T-T) and compression-compression (C-C) cycling occurred at about 60% of the respective static strengths. The overall results were expressed in the form of a constant life diagram showing the relationship between mean stress and stress amplitude. The diagram illustrates a skew-symmetry in fatigue life caused by the relatively low compressive strength of the unrestrained test specimens used. In effect, a maximum in fatigue properties occurs at a positive value of mean stress. Results are of significance in situations where structural members are buckling or crippling critical in design

    Cellular Automata and Ultra-Discrete Painlev\'e Equations

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    Starting from integrable cellular automata we present a novel form of Painlev\'e equations. These equations are discrete in both the independent variable and the dependent one. We show that they capture the essence of the behavior of the Painlev\'e equations organizing themselves into a coalescence cascade and possessing special solutions. A necessary condition for the integrability of cellular automata is also presented.Comment: 8 pages, plainTeX, 2 figure

    Integrable systems without the Painlev\'e property

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    We examine whether the Painlev\'e property is a necessary condition for the integrability of nonlinear ordinary differential equations. We show that for a large class of linearisable systems this is not the case. In the discrete domain, we investigate whether the singularity confinement property is satisfied for the discrete analogues of the non-Painlev\'e continuous linearisable systems. We find that while these discrete systems are themselves linearisable, they possess nonconfined singularities

    COMPARATIVE STUDY ON ANTIMICROBIAL ACTIVITY OF SEAWEEDS

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    Objective: Secondary metabolites from natural resources are a potential source of antimicrobial leads and drugs can exploited to combat antimicrobial resistance in microorganisms. Seaweeds are considered as a valuable source with a broad spectrum of biological activities. Hence, this study was undertaken to screen seaweeds from Mandapam coastal waters, East coast of India, for antimicrobial activity.Methods: Compounds were extracted using methanol from the seaweeds, namely, Halimeda gracilis, Caulerpa serrulata, Sargassum swartzii, Sargassum wightii, Jania rubens, Ulva lactuca, Ulva fasciata, Gracilaria corticata, Stoechospermum marginatum, Caulerpa scalpelliformis, Caulerpa taxifolia, Chaetomorpha crassa, Enteromorpha flexuosa, and Turbinaria ornate. The extracts were screened for their antimicrobial activity against selected bacterial and fungal pathogens.Results: In the present study, S. swartzii, J. rubens, and S. marginatum showed broad spectrum of antibacterial activity against all the test bacterial pathogens. Among these, the maximum activity was exhibited by S. swartzii against Enterococcus faecalis (27.00 ± 0.88) and Streptococcus pyogenes (23.00 ± 0.84), followed by J. rubens against E. faecalis (26.00 ± 0.56) and S. pyogenes (22.00 ± 0.75), and S. marginatum exhibited significant inhibition against Staphylococcus aureus (15.00 ± 0.22) and S. pyogenes (18.00 ± 1.16).Conclusion: These seaweeds with significant antibacterial activity will subjected to phytochemical screening to find out the potential active principle responsible for antimicrobial activity. It is followed by purification and characterization of the compounds for possible application in drug formulation, can take this to large-scale application in pharmaceutical industries

    On a q-difference Painlev\'e III equation: I. Derivation, symmetry and Riccati type solutions

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    A q-difference analogue of the Painlev\'e III equation is considered. Its derivations, affine Weyl group symmetry, and two kinds of special function type solutions are discussed.Comment: arxiv version is already officia

    Critical Role of the Secondary Binding Pocket in Modulating the Enzymatic Activity of DUSP5 toward Phosphorylated ERKs

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    DUSP5 is an inducible nuclear dual-specificity phosphatase that specifically interacts with and deactivates extracellular signal-regulated kinases ERK1 and ERK2, which are responsible for cell proliferation, differentiation, and survival. The phosphatase domain (PD) of DUSP5 has unique structural features absent from other nuclear DUSPs, such as the presence of a secondary anion-binding site in the proximity of the reaction center and a glutamic acid E264 positioned next to the catalytic cysteine C263, as well as a remote intramolecular disulfide linkage. The overall 400 ns molecular dynamics simulations indicate that the secondary binding site of DUSP5 PD acts as an allosteric regulator of the phosphatase activity of DUSP5. Our studies have identified E264 as a critical constituent of the dual binding pocket, which regulates the catalytic activity of DUSP5 by forming a salt bridge with arginine R269. Molecular dynamics studies showed that initial occupation of the secondary binding pocket leads to the breakage of the salt bridge, which then allows the occupation of the active site. Indeed, biochemical analysis using the pERK assay on mutant E264Q demonstrated that mutation of glutamic acid E264 leads to an increase in the DUSP5 catalytic activity. The role of the secondary binding site in assembling the DUSP5–pERK pre-reactive complex was further demonstrated by molecular dynamics simulations that showed that the remote C197–C219 disulfide linkage controls the structure of the secondary binding pocket based on its redox state (i.e., disulfide/dithiol) and, in turn, the enzymatic activity of DUSP5

    An interesting case of Phocomelia

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    Authors present a very rare case of tetra-phocomelia evaluated by antenatal ultrasonography. It is a condition seen in 0.62 per 100,000 live births. This is a congenital chromosomal abnormality involving the musculoskeletal system. Primi gravida with spontaneous conception after a long period of infertility underwent early anomaly scan. Patient was not aware of the last menstrual period hence; NT scan was missed. Routine early anomaly scan done between 16-18 weeks of pregnancy diagnosed a fetus with Tetra-Phocomelia. Due to the lack of associated symptoms or significant history, our case did not fit into any specific syndrome and appears to be the result of a sporadic, non-hereditary limb deficiency involving all four limb buds.  Second opinion obtained from a fetal medicine consultant who confirmed the diagnosis. Hence, decided for mid trimester termination and fetus was expelled after 8 hours. Fetus was not sent for pathological analysis. Tetra-phocomelia is a rare congenital anomaly and it may be associated with other deformity also. 1st case of phocomelia was described after the intake of thalidomide. In this condition hands and feet are seen as small flippers of a seal. The differential diagnosis includes sporadic phocomelia, Holt-Oram syndrome, thrombocytopenia-absent radius syndrome (TAR syndrome), Robert’s syndrome, and thalidomide-induced phocomelia. Here authors are presenting a rare case of Phocomelia where there is no history of drug intake or family history. This has to differentiate from thrombocytopenia-absent radius syndrome (TAR syndrome), sporadic phocomelia, Holt-Oram syndrome, Robert’s syndrome, and thalidomide-induced phocomelia

    Aggressive angiomyxoma

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    Angiomyxoma is a rare slow-growing, benign low-grade tumor occurring in women of reproductive age group which is known for its recurrence. The symptoms are variable. Mrs. K. aged 33 years, reached our outpatient department (OPD) with complaints of painless swelling on the right labial region which she was feeling uncomfortable while sitting. Mass was found to be mobile with no evidence of inflammatory change. The location of the mass made us think about, Bartholin’s cyst and hence surgical excision of the mass was done. The whole mass was found to be lying below the fat in the right labial region and wide excision was completed. The histopathology of the mass was reported as angiomyxoma. Angiomyxoma arises from the mesenchymal tissue and it is locally invasive with high recurrence rate. It is more common in females. Mostly seen in the vulvovaginal, pelvic cavity and perineum. The lesion can reach huge size. It has to be differentiated from gynecologic malignancies, cyst, abscess and hernia. Histology along with immune-histochemistry can confirm the lesion. Wide excision is the mode of treatment. Incomplete excision can lead to relapse. Relapse can happen in 35-72% of the cases. Local recurrence may occur between 2 months to 15 years following initial diagnosis. Hence, follow up is essential. Angiomyxoma is a very rare condition and only around 250 cases have been reported in the world literature. It has to be differentiated from other benign conditions. Diagnosed by non-invasive techniques like ultrasound sonography (USG), magnetic resonance imaging (MRI) and computed tomography (CT). Wide excision is the treatment of choice. Long term follow up is needed as recurrences are high
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