682 research outputs found

    Identifikasi Manifestasi Panas Bumi Dengan Memanfaatkan Kanal Thermal Pada Citra Landsat (Studi Kasus : Kawasan Dieng)

    Full text link
    Indonesia is one country that still uses fossil energy sources as a primary energy source. However, the availability of fossil energy sources is surely will be depleted when used continuously.In addition to the abundant fossil energy sources, Indonesia is also gifted new and renewable energy sources. The energy sources such as water, geothermal, biomass, solar, wind, up to uranium. Geothermal energy in Indonesia is estimated to be the third largest in the world. It is closely related to the position of Indonesia in the tectonic framework of the world. Dieng Plateau is a complex of volcanoes, vast plains shaped with a length of approximately 14 km, 6 km wide and extends from the Southwestern - Southeast. The availability of geothermal energy is not separated by a manifestations exist on the surface. Surface geothermal manifestations such as solfatar, fumaroles, hot steamy soil, silica sinter and hydrothermal alteration. All the manifestations of the surface has a relatively higher temperature then the surrounding environment. Remote sensing method is very effective in finding geothermal manifestations considering the research area covering a large area. Landsat image processing result of thermal band will generate hot spots that indicates the exist of geothermal manifestations. But the hot spots that gained are not all as geothermal manifestations. Therefore it needs separation of the hot spots in the form of geothermal manifestations and not a manifestation of geothermal. Landsat image processing results in this research showed the lowest temperature is 11,180 0C on Landsat imagery in 2006 and the highest temperature is 39,671 0C on Landsat imagery in 2014. The temperature range of geothermal manifestation which is recorded in this research is at 25,271 0C up to 39,671 0C. According to the level of consistency hot sightings from geothermal manifestations in this research, the manifestations of which are constantly showing the heat production is Sileri Crater and Condrodimuko Crater. Size manifestation that was detected by Landsat imagery wider than 30 m x 30 m in accordance with a spatial resolution of thermal band Landsat image

    Cranial and intra-axial metastasis originating from a primary ovarian Dysgerminoma.

    Get PDF
    Dysgerminomas are aggressive germ cell tumors that typically have a favorable prognosis, especially in patients diagnosed with early stage disease. We recount the history of a 23-year-old woman who was treated for a stage IA ovarian dysgerminoma in November 2017. Postoperatively, the patient was noncompliant insofar as obtaining routine lab evaluations; ten months later, she was diagnosed with a cranial metastasis that extended into the meninges. The patient subsequently underwent a posterior fossa craniotomy and adjuvant etoposide, bleomycin and cisplatin chemotherapy to which she initially responded; however, during cycle 4, she developed pancytopenia whereupon the chemotherapy was summarily discontinued. Thereafter, the patient was surveilled and currently, she remains in clinical remission. Early stage ovarian dysgerminoma, albeit rarely, has the capacity to metastasize to the cranium or brain, further underscoring the significance of employing active follow-up with these patients

    An Interstellar Conduction Front Within a Wolf-Rayet Ring Nebula Observed with the GHRS

    Full text link
    With the High Resolution Spectrograph aboard the Hubble Space Telescope we obtained high signal-to-noise (S/N > 200 - 600 per 17 km/s resolution element) spectra of narrow absorption lines toward the Wolf-Rayet star HD 50896. The ring nebula S308 that surrounds this star is thought to be caused by a pressure-driven bubble bounded by circumstellar gas (most likely from a red supergiant or luminous blue variable progenitor) pushed aside by a strong stellar wind. Our observation has shown for the first time that blueshifted (approximately 70 km/s relative to the star) absorption components of C IV and N V arise in a conduction front between the hot interior of the bubble and the cold shell of swept-up material. These lines set limits on models of the conduction front. Nitrogen in the shell appears to be overabundant by a factor ~10. The P Cygni profiles of N V and C IV are variable, possibly due to a suspected binary companion to HD 50896.Comment: 32 pages, Latex, to appear in the Astrophysical Journal, April, 199

    The Discovery of a Gravitationally Lensed Quasar at z = 6.51

    Get PDF
    Strong gravitational lensing provides a powerful probe of the physical properties of quasars and their host galaxies. A high fraction of the most luminous high-redshift quasars was predicted to be lensed due to magnification bias. However, no multiple imaged quasar was found at z>5 in previous surveys. We report the discovery of J043947.08+163415.7, a strongly lensed quasar at z=6.51, the first such object detected at the epoch of reionization, and the brightest quasar yet known at z>5. High-resolution HST imaging reveals a multiple imaged system with a maximum image separation theta ~ 0.2", best explained by a model of three quasar images lensed by a low luminosity galaxy at z~0.7, with a magnification factor of ~50. The existence of this source suggests that a significant population of strongly lensed, high redshift quasars could have been missed by previous surveys, as standard color selection techniques would fail when the quasar color is contaminated by the lensing galaxy.Comment: 8 pages, 4 figures, submitted to ApJ

    alpha II-spectrin and beta II-spectrin do not affect TGF beta 1-induced myofibroblast differentiation

    Get PDF
    Mechanosensing of fibroblasts plays a key role in the development of fibrosis. So far, no effective treatments are available to treat this devastating disorder. Spectrins regulate cell morphology and are potential mechanosensors in a variety of non-erythroid cells, but little is known about the role of spectrins in fibroblasts. We investigate whether II- and II-spectrin are required for the phenotypic properties of adult human dermal (myo)fibroblasts. Knockdown of II- or II-spectrin in fibroblasts did not affect cell adhesion, cell size and YAP nuclear/cytosolic localization. We further investigated whether II- and II-spectrin play a role in the phenotypical switch from fibroblasts to myofibroblasts under the influence of the pro-fibrotic cytokine TGF1. Knockdown of spectrins did not affect myofibroblast formation, nor did we observe changes in the organization of SMA stress fibers. Focal adhesion assembly was unaffected by spectrin deficiency, as was collagen type I mRNA expression and protein deposition. Wound closure was unaffected as well, showing that important functional properties of myofibroblasts are unchanged without II- or II-spectrin. In fact, fibroblasts stimulated with TGF1 demonstrated significantly lower endogenous mRNA levels of II- and II-spectrin. Taken together, despite the diverse roles of spectrins in a variety of other cells, II- and II-spectrin do not regulate cell adhesion, cell size and YAP localization in human dermal fibroblasts and are not required for the dermal myofibroblast phenotypical switch

    Placental promoter methylation of DNA repair genes and prenatal exposure to particulate air pollution: an ENVIRONAGE cohort study

    Get PDF
    BACKGROUND: Exposure to particulate air pollution has been linked with risk of carcinogenesis. Damage to repair pathways might have long-term adverse health effects. We aimed to investigate the association of prenatal exposure to air pollution with placental mutation rate and the DNA methylation of key placental DNA repair genes. METHODS: This cohort study used data from the ongoing ENVironmental Influence ON early AGEing (ENVIRONAGE) birth cohort, which enrols pairs of mothers and neonates (singleton births only) at the East-Limburg Hospital (Genk, Belgium). Placental DNA samples were collected after birth. We used bisulfite-PCR-pyrosequencing to investigate the mutation rate of Alu (a marker for overall DNA mutation) and DNA methylation in the promoter genes of key DNA repair and tumour suppressor genes (APEX1, OGG1, PARP1, ERCC1, ERCC4, p53, and DAPK1). We used a high-resolution air pollution model to estimate exposure to particulate matter with a diameter less than 2·5 μm (PM2·5), black carbon, and NO2 over the entire pregnancy on the basis of maternal address. Alu mutation was analysed with a linear regression model, and methylation values of the selected genes were analysed in mixed-effects models. Effect estimates are presented as the relative percentage change in methylation for an ambient air pollution increment of one IQR (ie, the difference between the first and third quartiles of exposure in the entire cohort). FINDINGS: 500 biobanked placental DNA samples were randomly selected from 814 pairs of mothers and neonates who were recruited to the cohort between Feb 1, 2010, and Dec 31, 2014, of which 463 samples met the pyrosequencing quality control criteria. IQR exposure increments were 3·84 μg/m3 for PM2·5, 0·36 μg/m3 for black carbon, and 5·34 μg/m3 for NO2. Among these samples, increased Alu mutation rate was associated with greater exposure to PM2·5 (r=0·26, p<0·0001) and black carbon (r=0·33, p<0·0001), but not NO2. Promoter methylation was positively associated with PM2·5 in APEX1 (7·34%, 95% CI 0·52 to 14·16, p=0·009), OGG1 (13·06, 3·88 to 22·24, p=0·005), ERCC4 (16·31%, 5·43 to 27·18, p=0·01), and p53 (10·60%, 4·46 to 16·74, p=0·01), whereas promoter methylation of DAPK1 (-12·92%, -22·35 to -3·49, p=0·007) was inversely associated with PM2·5 exposure. Black carbon exposure was associated with elevated promoter methylation in APEX1 (9·16%, 4·06 to 14·25, p=0·01) and ERCC4 (27·56%, 17·58 to 37·55, p<0·0001). Promoter methylation was not associated with pollutant exposure in PARP1 and ERCC1, and NO2 exposure was not associated with methylation in any of the genes studied. INTERPRETATION: Transplacental in-utero exposure to particulate matter is associated with an increased overall placental mutation rate (as measured with Alu), which occurred in concert with epigenetic alterations in key DNA repair and tumour suppressor genes. Our results suggest that exposure to air pollution can induce changes to fetal and neonatal DNA repair capacity. Future studies will be essential to elucidate whether these changes persist and have a role in carcinogenic insults later in life. The work is supported by the European Research Council (ERC-2012-StG.310898 and ERC-2011-StG. 282413) and by the Flemish Scientific Fund (FWO,G073315N/G082317N)

    ALMA Observations of the Sub-kpc Structure of the Host Galaxy of a z= 6.5 Lensed Quasar: A Rotationally-Supported Hyper-Starburst System at the Epoch of Reionization

    Full text link
    We report ALMA observations of the dust continuum and {\cii} emission of the host galaxy of J0439+1634, a gravitationally lensed quasar at z=6.5z=6.5. Gravitational lensing boosts the source-plane resolution to \sim0\farcs15 (0.8 kpc)(\sim0.8\text{ kpc}). The lensing model derived from the ALMA data is consistent with the fiducial model in \citet{fan19} based on {\it HST} imaging. The host galaxy of J0439+1634 can be well-fitted by a S\'ersic profile consistent with an exponential disk, both in the far-infrared (FIR) continuum and the {\cii} emission. The overall magnification is 4.53±0.054.53\pm0.05 for the continuum and 3.44±0.053.44\pm0.05 for the {\cii} line. The host galaxy of J0439+1634 is a compact ultra-luminous infrared galaxy, with a total star formation rate (SFR) of 1.56×103M/year1.56\times10^{3}M_\odot/\text{year} after correcting for lensing and an effective radius of 0.740.74 kpc. The resolved regions in J0439+1634 follow the ``{\cii} deficit," where the {\cii}-to-FIR ratio decreases with FIR surface brightness. The reconstructed velocity field of J0439+1634 appears to be rotation-like. The maximum line-of-sight rotation velocity of 130 km/s at a radius of 2 kpc. However, our data cannot be fit by an axisymmetric thin rotating disk, and the inclination of the rotation axis, ii, remains unconstrained. We estimate the dynamical mass of the host galaxy to be 7.9sin2(i)×109M7.9\sin^{-2}(i)\times10^{9}M_\odot. J0439+1634 is likely to have a high gas-mass fraction and an oversized SMBH compared to local relations. The SFR of J0439+1634 reaches the maximum possible values, and the SFR surface density is close to the highest value seen in any star-forming galaxy currently known in the universe.Comment: 14 pages, 7 figures. Accepted by Ap

    An 800-million-solar-mass black hole in a significantly neutral Universe at redshift 7.5

    Get PDF
    Quasars are the most luminous non-transient objects known and as a result they enable studies of the Universe at the earliest cosmic epochs. Despite extensive efforts, however, the quasar ULAS J1120+0641 at z=7.09 has remained the only one known at z>7 for more than half a decade. Here we report observations of the quasar ULAS J134208.10+092838.61 (hereafter J1342+0928) at redshift z=7.54. This quasar has a bolometric luminosity of 4e13 times the luminosity of the Sun and a black hole mass of 8e8 solar masses. The existence of this supermassive black hole when the Universe was only 690 million years old---just five percent of its current age---reinforces models of early black-hole growth that allow black holes with initial masses of more than about 1e4 solar masses or episodic hyper-Eddington accretion. We see strong evidence of absorption of the spectrum of the quasar redwards of the Lyman alpha emission line (the Gunn-Peterson damping wing), as would be expected if a significant amount (more than 10 per cent) of the hydrogen in the intergalactic medium surrounding J1342+0928 is neutral. We derive a significant fraction of neutral hydrogen, although the exact fraction depends on the modelling. However, even in our most conservative analysis we find a fraction of more than 0.33 (0.11) at 68 per cent (95 per cent) probability, indicating that we are probing well within the reionization epoch of the Universe.Comment: Updated to match the final journal versio
    corecore