281 research outputs found

    The Atacama Cosmology Telescope: CO(J = 3 - 2) mapping and lens modeling of an ACT-selected dusty star-forming galaxy

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    We report Northern Extended Millimeter Array (NOEMA) CO(J=3−2J = 3 - 2) observations of the dusty star-forming galaxy ACT-S\,J020941+001557 at z=2.5528z = 2.5528, which was detected as an unresolved source in the Atacama Cosmology Telescope (ACT) equatorial survey. Our spatially resolved spectral line data support the derivation of a gravitational lens model from 37 independent velocity channel maps using a pixel-based algorithm, from which we infer a velocity-dependent magnification factor μ≈7−22\mu \approx 7-22 with a luminosity-weighted mean \left\approx 13. The resulting source-plane reconstruction is consistent with a rotating disk, although other scenarios cannot be ruled out by our data. After correction for lensing, we derive a line luminosity LCO(3−2)′=(5.53±0.69)×1010  K km s−1 pc2L^{\prime}_{\rm CO(3-2)}= (5.53\pm 0.69) \times 10^{10}\,{\rm \,K\,km\,s^{-1}\,pc^{2}}, a cold gas mass Mgas=(3.86±0.33)×1010 M⊙M_{{\rm gas}}= (3.86 \pm 0.33) \times 10^{10}\,M_{\odot}, a dynamical mass Mdyn sin2 i=3.9−1.5+1.8×1010 M⊙M_{\rm dyn}\,{\rm sin}^2\,i = 3.9^{+1.8}_{-1.5} \times 10^{10}\,M_{\odot}, and a gas mass fraction fgas csc2 i=1.0−0.4+0.8f_{\rm gas}\,{\rm csc}^2\,i = 1.0^{+0.8}_{-0.4}. The line brightness temperature ratio of r3,1≈1.6r_{3,1}\approx 1.6 relative to a Green Bank Telescope CO(J=1−0J=1-0) detection may be elevated by a combination of external heating of molecular clouds, differential lensing, and/or pointing errors.Comment: 8 pages, 5 figures, accepted to Ap

    tRNA methylation resolves codon usage bias at the limit of cell viability.

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    Codon usage of each genome is closely correlated with the abundance of tRNA isoacceptors. How codon usage bias is resolved by tRNA post-transcriptional modifications is largely unknown. Here we demonstrate that the N1-methylation of guanosine at position 37 (m1G37) on the 3'-side of the anticodon, while not directly responsible for reading of codons, is a neutralizer that resolves differential decoding of proline codons. A genome-wide suppressor screen of a non-viable Escherichia coli strain, lacking m1G37, identifies proS suppressor mutations, indicating a coupling of methylation with tRNA prolyl-aminoacylation that sets the limit of cell viability. Using these suppressors, where prolyl-aminoacylation is decoupled from tRNA methylation, we show that m1G37 neutralizes differential translation of proline codons by the major isoacceptor. Lack of m1G37 inactivates this neutralization and exposes the need for a minor isoacceptor for cell viability. This work has medical implications for bacterial species that exclusively use the major isoacceptor for survival

    The Role of Purinergic Signaling in the Pathophysiology of Perinatal Hypoxic-Ischemic Encephalopathy

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    Perinatal hypoxic-ischemic encephalopathy (HIE), known as birth asphyxia, remains a major contributor to poor neurodevelopmental outcomes including cerebral palsy and seizures. One striking feature of HIE injury is a delayed progression of neuronal degeneration that spreads over time from the most severely damaged areas outward into neighboring undamaged regions. There is increasing evidence that these lesions act as sites of origin for waves of spreading depression (SD), a wave of neuronal and glial depolarization, that progressively enlarge the brain lesions. While the pathophysiology of SD is still under debate, there is increasing evidence that purinergic receptors in conjunction with connexin and pannexin 1 channels are necessary for sustained propagation of the waves and neuroinflammation. This review intends to discuss the relative contribution of purinergic signaling and connexin and pannexin 1 channels to trigger and spread SD waves leading to the development of progressive brain lesions under conditions of perinatal HIE

    Dinoprostone vaginal insert (DVI) versus adjunctive sweeping of membranes and DVI for term induction of labor.

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    AIM: To compare the efficacy and safety of dinoprostone vaginal insert (DVI) alone versus DVI with adjunctive sweeping of membranes (ASM) for induction of labor (IOL). METHODS: Single-center, prospective, randomized controlled trial; women with singleton term pregnancies, cervical dilation ≥1 and <3 cm, intact membranes allocated to either DVI or DVI with ASM. The primary outcome was vaginal delivery within 24 h of insertion. Secondary outcomes included mean time from insertion to delivery, tachysystole, operative delivery for non-reassuring fetal status (NRFS), tocolytics, fetal outcomes, pain information, and subject satisfaction. RESULTS: One hundred and four received DVI (Group 1) alone and 104 DVI with ASM (Group 2). The rate of vaginal delivery within 24 h was 53% versus 56%, cesarean rate 8.7% versus 10.6% in Groups 1 and 2 respectively. Although the duration of labor was similar in both groups, about 6% of women required additional ripening with dinoprostone vaginal tablets in Group 2 compared to 11.5% in Group 1 (p-value = 0.2). The frequency of hyperstimulation syndrome, failed induction, analgesic requirements, and fetal outcomes were comparable. The majority (83%-86%) in either cohort were satisfied with their labor experience. Multivariate logistic regression demonstrated a slightly better chance for vaginal delivery within 24 h (odds ratio [OR] 1.22 [95% confidence interval, CI 0.65-2.29]; p-value 0.53] for DVI with ASM, although statistically insignificant. Younger maternal age and multiparity (OR 10.36 [95% CI 4.88-23.67]; p-value <0.0001) contributed to successful IOL. CONCLUSION: DVI with ASM is at least as efficacious as DVI for cervical ripening with no increase in morbidity. Although DVI with ASM group less often needed additional dinoprostone tablets to complete the process of IOL (p-value = 0.2), adjunctive sweeping has not been shown to have a significant impact on the duration of labor or mode of delivery

    GABA regulates electrical activity and tumor initiation in melanoma

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    Oncogenes can initiate tumors only in certain cellular contexts, which is referred to as oncogenic competence. In melanoma, whether cells in the microenvironment can endow such competence remains unclear. Using a combination of zebrafish transgenesis coupled with human tissues, we demonstrate that GABAergic signaling between keratinocytes and melanocytes promotes melanoma initiation by BRAFV600E. GABA is synthesized in melanoma cells, which then acts on GABA-A receptors in keratinocytes. Electron microscopy demonstrates specialized cell–cell junctions between keratinocytes and melanoma cells, and multielectrode array analysis shows that GABA acts to inhibit electrical activity in melanoma/keratinocyte cocultures. Genetic and pharmacologic perturbation of GABA synthesis abrogates melanoma initiation in vivo. These data suggest that GABAergic signaling across the skin microenvironment regulates the ability of oncogenes to initiate melanoma. Significance: This study shows evidence of GABA-mediated regulation of electrical activity between melanoma cells and keratinocytes, providing a new mechanism by which the microenvironment promotes tumor initiation. This provides insights into the role of the skin microenvironment in early melanomas while identifying GABA as a potential therapeutic target in melanoma

    Toward an internally consistent astronomical distance scale

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    Accurate astronomical distance determination is crucial for all fields in astrophysics, from Galactic to cosmological scales. Despite, or perhaps because of, significant efforts to determine accurate distances, using a wide range of methods, tracers, and techniques, an internally consistent astronomical distance framework has not yet been established. We review current efforts to homogenize the Local Group's distance framework, with particular emphasis on the potential of RR Lyrae stars as distance indicators, and attempt to extend this in an internally consistent manner to cosmological distances. Calibration based on Type Ia supernovae and distance determinations based on gravitational lensing represent particularly promising approaches. We provide a positive outlook to improvements to the status quo expected from future surveys, missions, and facilities. Astronomical distance determination has clearly reached maturity and near-consistency.Comment: Review article, 59 pages (4 figures); Space Science Reviews, in press (chapter 8 of a special collection resulting from the May 2016 ISSI-BJ workshop on Astronomical Distance Determination in the Space Age

    Cosmological distance indicators

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    We review three distance measurement techniques beyond the local universe: (1) gravitational lens time delays, (2) baryon acoustic oscillation (BAO), and (3) HI intensity mapping. We describe the principles and theory behind each method, the ingredients needed for measuring such distances, the current observational results, and future prospects. Time delays from strongly lensed quasars currently provide constraints on H0H_0 with < 4% uncertainty, and with 1% within reach from ongoing surveys and efforts. Recent exciting discoveries of strongly lensed supernovae hold great promise for time-delay cosmography. BAO features have been detected in redshift surveys up to z <~ 0.8 with galaxies and z ~ 2 with Ly-α\alpha forest, providing precise distance measurements and H0H_0 with < 2% uncertainty in flat Λ\LambdaCDM. Future BAO surveys will probe the distance scale with percent-level precision. HI intensity mapping has great potential to map BAO distances at z ~ 0.8 and beyond with precisions of a few percent. The next years ahead will be exciting as various cosmological probes reach 1% uncertainty in determining H0H_0, to assess the current tension in H0H_0 measurements that could indicate new physics.Comment: Review article accepted for publication in Space Science Reviews (Springer), 45 pages, 10 figures. Chapter of a special collection resulting from the May 2016 ISSI-BJ workshop on Astronomical Distance Determination in the Space Ag

    A survey of individual preference for colorectal cancer screening technique

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    BACKGROUND: Due to the low participation in colorectal cancer screening, public preference for colorectal cancer screening modality was determined. METHODS: A cross-sectional survey was performed of healthy ambulatory adults in a pediatrics primary care office and neighboring church. Overall preference was ranked for each of four colorectal cancer screening modalities: Faecal Occult Blood, Fiberoptic Sigmoidoscopy, Barium Enema and Colonoscopy. Four additional domains of preference also were ranked: suspected discomfort, embarrassment, inconvenience and danger of each exam. RESULTS: 80 surveys were analyzed, 57 of which were received from participants who had experienced none of the screening tests. Fecal Occult Blood Testing is significantly preferred over each other screening modality in overall preference and every domain of preference, among all subjects and those who had experienced none of the tests. CONCLUSIONS: Efforts to increase public participation in colorectal cancer screening may be more effective if undertaken in the context of public perceptions of screening choices

    Pulmonary hemorrhage syndrome associated with dengue fever, High-resolution computed tomography findings: a case report

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    Dengue hemorrhagic fever is an acute infectious disease caused by dengue virus. We described the high-resolution CT findings in a 70-year-old male with the disease, which was diagnosed by clinical examination and confirmed by serological methods. High-resolution CT demonstrated bilateral areas of consolidation with air bronchogram and ground glass opacities, as well as small bilateral pleural effusions. Dengue hemorrhagic fever should be considered in the differential diagnosis of diffuse pulmonary hemorrhage

    "The fruits of independence": Satyajit Ray, Indian nationhood and the spectre of empire

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    Challenging the longstanding consensus that Satyajit Ray's work is largely free of ideological concerns and notable only for its humanistic richness, this article shows with reference to representations of British colonialism and Indian nationhood that Ray's films and stories are marked deeply and consistently by a distinctively Bengali variety of liberalism. Drawn from an ongoing biographical project, it commences with an overview of the nationalist milieu in which Ray grew up and emphasizes the preoccupation with colonialism and nationalism that marked his earliest unfilmed scripts. It then shows with case studies of Kanchanjangha (1962), Charulata (1964), First Class Kamra (First-Class Compartment, 1981), Pratidwandi (The Adversary, 1970), Shatranj ke Khilari (The Chess Players, 1977), Agantuk (The Stranger, 1991) and Robertsoner Ruby (Robertson's Ruby, 1992) how Ray's mature work continued to combine a strongly anti-colonial viewpoint with a shifting perspective on Indian nationhood and an unequivocal commitment to cultural cosmopolitanism. Analysing how Ray articulated his ideological positions through the quintessentially liberal device of complexly staged debates that were apparently free, but in fact closed by the scenarist/director on ideologically specific notes, this article concludes that Ray's reputation as an all-forgiving, ‘everybody-has-his-reasons’ humanist is based on simplistic or even tendentious readings of his work
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