394 research outputs found

    Effects of Noise on Galaxy Isophotes

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    The study of shapes of the images of objects is an important issue not only because it reveals its dynamical state but also it helps to understand the object's evolutionary history. We discuss a new technique in cosmological image analysis which is based on a set of non-parametric shape descriptors known as the Minkowski Functionals (MFs). These functionals are extremely versatile and under some conditions give a complete description of the geometrical properties of objects. We believe that MFs could be a useful tool to extract information about the shapes of galaxies, clusters of galaxies and superclusters. The information revealed by MFs can be utilized along with the knowledge obtained from currently popular methods and thus could improve our understanding of the true shapes of cosmological objects.Comment: 3 pages, 1 figure, to appear in "The IGM/Galaxy Connection - The Distribution of Baryons at z=0" Conference Proceeding

    Caesarean section in a tertiary care centre

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    Background: Caesarean section constitutes a major surgical procedure characterized with morbidity even if it is performed a planned procedure. Postoperative infection in obstetrics continues to affect the practice of every surgeon. Infection can cause an increase in patient’s stay in the hospital, create discomfort, cause disfigurement and lead to morbidities to the patient. Thus, preventive measures need to be constantly evaluated and updated and hence authors have to study and analyse prevalence of postoperative infectious morbidities.Methods: The study was conducted in an Urban Based Medical College Hospital in Ahmedabad. It was a retrospective cross-sectional study of 50 cases of patients who suffered infectious complications post caesarean from 1st March 2019 to 31st March 2020.Results: The prevalence rate of surgical site infection in my study is 5.9% whereas of post-operative puerperal sepsis is 0.6%, of post-operative urinary tract infection is 1.09%, of post-operative breast abnormalities is 0.16%. The most common infectious morbidity amongst all was surgical site infection (surgical site) infection and its prevalence was 5.9%.Conclusions: The development of post-operative infection is an important event that can be prevented by taking proper precautions and following prescribed guidelines. There should be specific use of antibiotics in the post-operative period. In the event of early signs of sepsis antibiotics should be administered properly as per culture sensitivity report. The decrease in infection rate also indirectly reduce the health costs involved in treating them post operatively

    Low Frequency Broad Band Acoustic Propagation in Andaman Sea

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    During November 2017, an active source seismic survey was performed in Andaman sea to study the acoustic propagation characteristics. High power low frequency acoustic signals generated by 20-air gun array onboard ORV Samudra Ratnagar were recorded from INS Sagardhwani at four different depths within 8 km ranges in shallow and deep waters. Low frequency sound levels were estimated using root mean square and power spectral values. Amplitude levels were analysed with respect to arrival time variation with frequency and is presented

    Effect of Environment on Underwater Acoustic Communication Data Rates

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    Underwater acoustic communication has several applications for civilians and defence. It is a challenging engineering problem, where large variability of ambient noise and highly variable channel characteristics limits the performance of communication system. In addition horizontal transmissions in shallow water is considered very challenging due to time varying delay spread and significant Doppler spread. An experiment was conducted to study the diurnal variability of underwater acoustic communication channel properties of the south west coast of India. Time spread and bit error rate for different ranges and depths are compared in this paper. Influence of prevailing sound speed profile on acoustic communication link is also discussed

    Dark energy from conformal symmetry breaking

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    The breakdown of conformal symmetry in a conformally invariant scalar-tensor gravitational model is revisited in the cosmological context. Although the old scenario of conformal symmetry breaking in cosmology containing scalar field has already been used in many earlier works, it seems that no special attention has been paid for the investigation on the possible connection between the breakdown of conformal symmetry and the existence of dark energy. In this paper, it is shown that the old scenario of conformal symmetry breaking in cosmology, if properly interpreted, not only has a potential ability to describe the origin of dark energy as a symmetry breaking effect, but also may resolve the coincidence problem.Comment: 11 pages, minor revision, published online in EPJ

    Physiological and pathological roles of LRRK2 in the nuclear envelope integrity

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    Mutations in LRRK2 cause autosomal dominant and sporadic Parkinson’s disease but the mechanisms involved in LRRK2 toxicity in PD are yet to be fully understood. We found that LRRK2 translocates to the nucleus by binding to seven in absentia homolog (SIAH-1), and in the nucleus it directly interacts with lamin A/C, independent of its kinase activity. LRRK2 knockdown caused nuclear lamina abnormalities and nuclear disruption. LRRK2 disease mutations mostly abolish the interaction with lamin A/C and, similar to LRRK2 knockdown, cause disorganization of lamin A/C and leakage of nuclear proteins. Dopaminergic neurons of LRRK2 G2019S transgenic and LRRK2 -/- mice display decreased circularity of the nuclear lamina and leakage of the nuclear protein 53BP1 to the cytosol. Dopaminergic nigral and cortical neurons of both LRRK2 G2019S and idiopathic PD patients exhibit abnormalities of the nuclear lamina. Our data indicate that LRRK2 plays an essential role in maintaining nuclear envelope integrity. Disruption of this function by disease mutations suggests a novel phosphorylation-independent loss of function mechanism that may synergize with other neurotoxic effects caused by LRRK2 mutations

    SUMOylation and ubiquitination reciprocally regulate α-synuclein degradation and pathological aggregation

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    α-Synuclein accumulation is a pathological hallmark of Parkinson’s disease (PD). Ubiquitinated α-synuclein is targeted to proteasomal or lysosomal degradation. Here, we identify SUMOylation as a major mechanism that counteracts ubiquitination by different E3 ubiquitin ligases and regulates α-synuclein degradation. We report that PIAS2 promotes SUMOylation of α-synuclein, leading to a decrease in α-synuclein ubiquitination by SIAH and Nedd4 ubiquitin ligases, and causing its accumulation and aggregation into inclusions. This was associated with an increase in α-synuclein release from the cells. A SUMO E1 inhibitor, ginkgolic acid, decreases α-synuclein levels by relieving the inhibition exerted on α-synuclein proteasomal degradation. α-Synuclein disease mutants are more SUMOylated compared with the wild-type protein, and this is associated with increased aggregation and inclusion formation. We detected a marked increase in PIAS2 expression along with SUMOylated α-synuclein in PD brains, providing a causal mechanism underlying the up-regulation of α-synuclein SUMOylation in the disease. We also found a significant proportion of Lewy bodies in nigral neurons containing SUMO1 and PIAS2. Our observations suggest that SUMOylation of α-synuclein by PIAS2 promotes α-synuclein aggregation by two mutually reinforcing mechanisms. First, it has a direct proaggregatory effect on α-synuclein. Second, SUMOylation facilitates α-synuclein aggregation by blocking its ubiquitin-dependent degradation pathways and promoting its accumulation. Therefore, inhibitors of α-synuclein SUMOylation provide a strategy to reduce α-synuclein levels and possibly aggregation in PD

    Statefinder diagnostic and stability of modified gravity consistent with holographic and new agegraphic dark energy

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    Recently one of us derived the action of modified gravity consistent with the holographic and new-agegraphic dark energy. In this paper, we investigate the stability of the Lagrangians of the modified gravity as discussed in [M. R. Setare, Int. J. Mod. Phys. D 17 (2008) 2219; M. R. Setare, Astrophys. Space Sci. 326 (2010) 27]. We also calculate the statefinder parameters which classify our dark energy model.Comment: 12 pages, 2 figures, accepted by Gen. Relativ. Gravi

    A Moving Magnetic Trap Decelerator: a New Source for Cold Atoms and Molecules

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    We present an experimental realization of a moving magnetic trap decelerator, where paramagnetic particles entrained in a cold supersonic beam are decelerated in a co-moving magnetic trap. Our method allows for an efficient slowing of both paramagnetic atoms and molecules to near stopping velocities. We show that under realistic conditions we will be able to trap and decelerate a large fraction of the initial supersonic beam. We present our first results on deceleration in a moving magnetic trap by bringing metastable neon atoms to near rest. Our estimated phase space volume occupied by decelerated particles at final velocity of 50 m/s shows an improvement of two orders of magnitude as compared to currently available deceleration techniques
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