38 research outputs found

    Testing the no-hair nature of binary black holes using the consistency of multipolar gravitational radiation

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    Gravitational-wave (GW) observations of binary black holes offer the best probes of the relativistic, strong-field regime of gravity. Gravitational radiation in the leading order is quadrupolar. However, nonquadrupole (higher order) modes make appreciable contribution to the radiation from binary black holes with large mass ratios and misaligned spins. The multipolar structure of the radiation is fully determined by the intrinsic parameters (masses and spin angular momenta of the companion black holes) of a binary in quasicircular orbit. Following our previous work [S. Dhanpal, A. Ghosh, A. K. Mehta, P. Ajith, and B. S. Sathyaprakash, Phys. Rev. D 99, 104056 (2019).], we develop multiple ways of testing the consistency of the observed GW signal with the expected multipolar structure of radiation from binary black holes in general relativity. We call this a no-hair test of binary black holes as this is similar to testing the no-hair theorem for isolated black holes through mutual consistency of the quasinormal mode spectrum. We use Bayesian inference on simulated GW signals that are consistent/inconsistent with binary black holes in general relativity to demonstrate the power of the proposed tests. We also make estimate systematic errors arising as a result of neglecting companion spins

    Testing the no-hair nature of binary black holes using the consistency of multipolar gravitational radiation

    Get PDF
    Gravitational-wave (GW) observations of binary black holes offer the best probes of the relativistic, strong-field regime of gravity. Gravitational radiation in the leading order is quadrupolar. However, nonquadrupole (higher order) modes make appreciable contribution to the radiation from binary black holes with large mass ratios and misaligned spins. The multipolar structure of the radiation is fully determined by the intrinsic parameters (masses and spin angular momenta of the companion black holes) of a binary in quasicircular orbit. Following our previous work [S. Dhanpal, A. Ghosh, A. K. Mehta, P. Ajith, and B. S. Sathyaprakash, Phys. Rev. D 99, 104056 (2019).], we develop multiple ways of testing the consistency of the observed GW signal with the expected multipolar structure of radiation from binary black holes in general relativity. We call this a no-hair test of binary black holes as this is similar to testing the no-hair theorem for isolated black holes through mutual consistency of the quasinormal mode spectrum. We use Bayesian inference on simulated GW signals that are consistent/inconsistent with binary black holes in general relativity to demonstrate the power of the proposed tests. We also make estimate systematic errors arising as a result of neglecting companion spins

    Testing the no-hair nature of binary black holes using the consistency of multipolar gravitational radiation

    Get PDF
    Gravitational-wave (GW) observations of binary black holes offer the best probes of the relativistic, strong-field regime of gravity. Gravitational radiation in the leading order is quadrupolar. However, nonquadrupole (higher order) modes make appreciable contribution to the radiation from binary black holes with large mass ratios and misaligned spins. The multipolar structure of the radiation is fully determined by the intrinsic parameters (masses and spin angular momenta of the companion black holes) of a binary in quasicircular orbit. Following our previous work [S. Dhanpal, A. Ghosh, A. K. Mehta, P. Ajith, and B. S. Sathyaprakash, Phys. Rev. D 99, 104056 (2019).], we develop multiple ways of testing the consistency of the observed GW signal with the expected multipolar structure of radiation from binary black holes in general relativity. We call this a no-hair test of binary black holes as this is similar to testing the no-hair theorem for isolated black holes through mutual consistency of the quasinormal mode spectrum. We use Bayesian inference on simulated GW signals that are consistent/inconsistent with binary black holes in general relativity to demonstrate the power of the proposed tests. We also make estimate systematic errors arising as a result of neglecting companion spins

    Effect of Bacilli Calmette-Guerin vaccine on severe combined immunodeficiency patient: a narrative review and proposed workup algorithm

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    This systematic review critically investigates the administration of the Bacillus Calmette-GuΓ©rin (BCG) vaccine in neonates with severe combined immunodeficiency (SCID). The BCG vaccine, derived from Mycobacterium bovis, is a live attenuated vaccine recognized for its significant role in mitigating the impacts of tuberculosis (TB) in endemic areas. Despite its beneficial effects in controlling TB, safety and efficacy concerns have been raised when the vaccine is administered to SCID patients, who have a severe dysfunction or absence of the immune system. The potential for the vaccine to lead to severe complications due to the immunocompromised state of SCID patients necessitates a comprehensive investigation. To better understand these issues, a thorough literature review was carried out, integrating data from clinical trials and observational studies available on the PubMed database. An extensive review and analysis of 32 relevant articles revealed substantial evidence of complications from BCG vaccination in SCID patients. These findings emphasize the urgency for a more effective pre-vaccination screening process to circumvent potential adverse effects. Given the crucial role of the BCG vaccine in controlling TB, its potential to induce severe complications in SCID patients warrants careful consideration. Therefore, this review proposes an in-depth screening algorithm for newborns before BCG vaccination administration. The goal is to prevent these adverse events, offering critical insights to health policymakers, researchers, and clinicians in the field

    Mesoamerican nephropathy: a narrative review

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    Mesoamerican nephropathy (MeN) also known as chronic kidney disease of unknown etiology (CKDu) is prevalent in agriculturally rich areas. The most widely accepted pathophysiological explanation for MeN is chronic dehydration caused by prolonged exposure to the sun. Other theories include oxidative stress, chronic inflammation, infection and tubulointerstitial fibrosis. The clinical presentation is quite vague and is diagnosed similar to CKD from any cause using blood, urine analysis and ultrasound. The study highlights the need for interdisciplinary cooperation among physicians, epidemiologists, toxicologists, and geneticists while identifying significant research gaps and future objectives. Occupational health related to agriculture is not emphasised enough especially in third world countries where a large chunk of population heavily depend on farming. To safeguard the population at risk, the significance of community-based initiatives, occupational health measures, and regulatory changes is emphasised

    Characterizations of novel broad-spectrum lytic bacteriophages Sfin-2 and Sfin-6 infecting MDR Shigella spp. with their application on raw chicken to reduce the Shigella load

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    The evidence and prevalence of multidrug-resistant (MDR) Shigella spp. poses a serious global threat to public health and the economy. Food- or water-borne MDR Shigella spp. demands an alternate strategy to counteract this threat. In this regard, phage therapy has garnered great interest from medical practitioners and researchers as a potential way to combat MDR pathogens. In this observation, we isolated Shigella phages from environmental water samples and tested against various clinically isolated MDR Shigella spp. In this study, we have defined the isolation and detailed physical and genomic characterizations of two phages Sfin-2 and Sfin-6 from environmental water samples. The phages exhibited potent lytic activity against Shigella flexneri, Shigella dysenteriae, and Shigella sonnei. They showed absorption within 5–10 min, a burst size ranging from ~74 to 265 PFU/cell, and a latent period of 5–20 min. The phages were stable at a broad pH range and survived an hour at 50Β°C. The purified phages Sfin-2 and Sfin-6 belong to the Siphoviridae family with an isometric head (64.90 Β± 2.04 nm and 62.42 Β± 4.04 nm, respectively) and a non-contractile tail (145 Β± 8.5 nm and 148.47 Β± 14.5 nm, respectively). The in silico analysis concluded that the size of the genomic DNA of the Sfin-2 phage is 50,390 bp with a GC content of 44.90%, while the genome size of the Sfin-6 phage is 50,523 bp with a GC content of 48.30%. A total of 85 and 83 putative open reading frames (ORFs) were predicted in the Sfin-2 and Sfin-6 phages, respectively. Furthermore, a comparative genomic and phylogenetic analysis revealed that both phages represented different isolates and novel members of the T1-like phages. Sfin-2 and Sfin-6 phages, either individually or in a cocktail form, showed a significant reduction in the viable Shigella count on raw chicken samples after 72 h of incubation. Therefore, these results indicate that these phages might have a potential role in therapeutic approaches designed for shigellosis patients as well as in the biological control of MDR Shigella spp. in the poultry or food industry during the course of meat storage

    T Cells from Programmed Death-1 Deficient Mice Respond Poorly to Mycobacterium tuberculosis Infection

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    Programmed Death-1 (PD-1; CD279) receptor molecule is widely believed to be a negative regulator predominantly expressed by exhausted/activated mouse T cells. Upon interaction with its ligands, PD-L1 and PD-L2, PD-1 inhibits activation of T cells and cytokine production, which has been documented in various viral and fungal infections as well as in vitro studies. Therefore, inhibition of T cell responses by PD-1 resulted in disease resistance in a variety of mouse infection models studied heretofore.Here, we report that PD-1 deficient (PD-1(-/-)) mice infected with Mycobacterium tuberculosis (M. tb) H37Rv by the aerosol route have increased susceptibility as compared with their wild type littermates. Surprisingly, M. tb antigen-specific T cell proliferation was dramatically reduced in PD-1 deficient animals compared with wild-type littermates, and this was due to increased numbers of regulatory T cells (Tregs) and recruitment of mesenchymal stem cells. Furthermore, PD-1(-/-) mice exhibited decreases in the autophagy-induced LC3-B marker protein in macrophages.Our findings suggest that PD-1 does not play an inhibitory role during M. tb infection and instead promotes mycobacterial clearance in mice

    Early Secreted Antigen ESAT-6 of Mycobacterium tuberculosis Promotes Protective T Helper 17 Cell Responses in a Toll-Like Receptor-2-dependent Manner

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    Despite its relatively poor efficacy, Bacillus Calmette-GuΓ©rin (BCG) has been used as a tuberculosis (TB) vaccine since its development in 1921. BCG induces robust T helper 1 (Th1) immune responses but, for many individuals, this is not sufficient for host resistance against Mycobacterium tuberculosis (M. tb) infection. Here we provide evidence that early secreted antigenic target protein 6 (ESAT-6), expressed by the virulent M. tb strain H37Rv but not by BCG, promotes vaccine-enhancing Th17 cell responses. These activities of ESAT-6 were dependent on TLR-2/MyD88 signalling and involved IL-6 and TGF-Ξ² production by dendritic cells. Thus, animals that were previously infected with H37Rv or recombinant BCG containing the RD1 region (BCG::RD1) exhibited improved protection upon re-challenge with virulent H37Rv compared with mice previously infected with BCG or RD1-deficient H37Rv (H37RvΞ”RD1). However, TLR-2 knockout (TLR-2-/-) animals neither showed Th17 responses nor exhibited improved protection in response to immunization with H37Rv. Furthermore, H37Rv and BCG::RD1 infection had little effect on the expression of the anti-inflammatory microRNA-146a (miR146a) in dendritic cells (DCs), whereas BCG and H37RvΞ”RD1 profoundly induced its expression in DCs. Consistent with these findings, ESAT-6 had no effect on miR146a expression in uninfected DCs, but dramatically inhibited its upregulation in BCG-infected or LPS-treated DCs. Collectively, our findings indicate that, in addition to Th1 immunity induced by BCG, RD1/ESAT-6-induced Th17 immune responses are essential for optimal vaccine efficacy

    Design and general characteristics of sole fish gill nets of Ratnagiri, Maharashtra

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    722-724Gill net fishing is one of the popular fishing methods along the west coast of India. However, there are regional variations in their design, construction and operation. This paper deals with design and general characteristics of sole fish gill nets operated from Ratnagiri, Maharashtra. Main webbing of sole fish gill net was made up of material polyamide (PA) monofilament of 0.23 mm diameter and the mesh size varied in between 75 to 85 mm. Sole fish gill nets were set nets, operated near the coast mostly after monsoon season when the water was turbid. In Ratnagiri, the nets were fabricated with the hung length and hung depth which varied from 58.5 to 70.38 m and 3.42 to 3.92 m respectively. The total fleet length varied from 130 to 160 m. The sole fish gill net was operated in the depth ranging from 6 to 15 m. It was calculated that, average area covered by each unit in bottom set sole fish gill net was 213.85 m2. Ten to twenty number per unit of plastic or expanded polyvinyl chloride (PVC) floats were used on head rope and oval shape lead sinkers of 20 to 23 g weight and 72 to 100 number per unit were used on foot rope. Sole fish gill nets were locally known in marathi as β€œLepechi jali”
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