| 1. |
- Klionsky, Daniel J., et al.
(author)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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In: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Research review (peer-reviewed)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 2. |
- Bakker, D. C. E., et al.
(author)
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An update to the surface ocean CO2 atlas (SOCAT version 2)
- 2014
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In: Earth System Science Data. - : Copernicus GmbH. - 1866-3508 .- 1866-3516. ; 6:1, s. 69-90
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Journal article (peer-reviewed)abstract
- The Surface Ocean CO2 Atlas (SOCAT), an activity of the international marine carbon research community, provides access to synthesis and gridded fCO2 (fugacity of carbon dioxide) products for the surface oceans. Version 2 of SOCAT is an update of the previous release (version 1) with more data (increased from 6.3 million to 10.1 million surface water fCO 2 values) and extended data coverage (from 1968-2007 to 1968-2011). The quality control criteria, while identical in both versions, have been applied more strictly in version 2 than in version 1. The SOCAT website (http://www.socat.info/) has links to quality control comments, metadata, individual data set files, and synthesis and gridded data products. Interactive online tools allow visitors to explore the richness of the data. Applications of SOCAT include process studies, quantification of the ocean carbon sink and its spatial, seasonal, year-to-year and longerterm variation, as well as initialisation or validation of ocean carbon models and coupled climate-carbon models. © Author(s) 2014. CC Attribution 3.0 License.
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| 3. |
- Botticella, M. T., et al.
(author)
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Supernova 2009kf : An Ultraviolet Bright Type IIP Supernova Discovered with Pan-STARRS 1 and GALEX
- 2010
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In: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 717, s. L52-L56
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Journal article (peer-reviewed)abstract
- We present photometric and spectroscopic observations of a luminous Type IIP Supernova (SN) 2009kf discovered by the Pan-STARRS 1 (PS1) survey and also detected by the Galaxy Evolution Explorer. The SN shows a plateau in its optical and bolometric light curves, lasting approximately 70 days in the rest frame, with an absolute magnitude of M V = -18.4 mag. The P-Cygni profiles of hydrogen indicate expansion velocities of 9000 km s-1 at 61 days after discovery which is extremely high for a Type IIP SN. SN 2009kf is also remarkably bright in the near-ultraviolet (NUV) and shows a slow evolution 10-20 days after optical discovery. The NUV and optical luminosity at these epochs can be modeled with a blackbody with a hot effective temperature (T ~ 16,000 K) and a large radius (R ~ 1 × 1015 cm). The bright bolometric and NUV luminosity, the light curve peak and plateau duration, the high velocities, and temperatures suggest that 2009kf is a Type IIP SN powered by a larger than normal explosion energy. Recently discovered high-z SNe (0.7 < z < 2.3) have been assumed to be IIn SNe, with the bright UV luminosities due to the interaction of SN ejecta with a dense circumstellar medium. UV-bright SNe similar to SN 2009kf could also account for these high-z events, and its absolute magnitude M NUV = -21.5 ± 0.5 mag suggests such SNe could be discovered out to z ~ 2.5 in the PS1 survey.
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| 4. |
- Pastorello, A., et al.
(author)
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Ultra-bright Optical Transients are Linked with Type Ic Supernovae
- 2010
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In: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 724, s. L16-L21
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Journal article (peer-reviewed)abstract
- Recent searches by unbiased, wide-field surveys have uncovered a group of extremely luminous optical transients. The initial discoveries of SN 2005ap by the Texas Supernova Search and SCP-06F6 in a deep Hubble pencil beam survey were followed by the Palomar Transient Factory confirmation of host redshifts for other similar transients. The transients share the common properties of high optical luminosities (peak magnitudes ~-21 to -23), blue colors, and a lack of H or He spectral features. The physical mechanism that produces the luminosity is uncertain, with suggestions ranging from jet-driven explosion to pulsational pair instability. Here, we report the most detailed photometric and spectral coverage of an ultra-bright transient (SN 2010gx) detected in the Pan-STARRS 1 sky survey. In common with other transients in this family, early-time spectra show a blue continuum and prominent broad absorption lines of O II. However, about 25 days after discovery, the spectra developed type Ic supernova features, showing the characteristic broad Fe II and Si II absorption lines. Detailed, post-maximum follow-up may show that all SN 2005ap and SCP-06F6 type transients are linked to supernovae Ic. This poses problems in understanding the physics of the explosions: there is no indication from late-time photometry that the luminosity is powered by 56Ni, the broad light curves suggest very large ejected masses, and the slow spectral evolution is quite different from typical Ic timescales. The nature of the progenitor stars and the origin of the luminosity are intriguing and open questions.
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| 5. |
- Nicholl, M., et al.
(author)
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Slowly fading super-luminous supernovae that are not pair-instability explosions
- 2013
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 502:7471, s. 346-
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Journal article (peer-reviewed)abstract
- Super-luminous supernovae(1-4) that radiate more than 1044 ergs per second at their peak luminosity have recently been discovered in faint galaxies at redshifts of 0.1-4. Some evolve slowly, resembling models of 'pair-instability' supernovae(5,6). Such models involve stars with original masses 140-260 times that of the Sun that now have carbon-oxygen cores of 65-130 solar masses. In these stars, the photons that prevent gravitational collapse are converted to electron-positron pairs, causing rapid contraction and thermonuclear explosions. Many solar masses of Ni-56 are synthesized; this isotope decays to Fe-56 via Co-56, powering bright light curves(7,8). Such massive progenitors are expected to have formed from metal-poor gas in the early Universe(9). Recently, supernova 2007bi in a galaxy at redshift 0.127 (about 12 billion years after the Big Bang) with a metallicity one-third that of the Sun was observed to look like a fading pair-instability supernova(1,10). Here we report observations of two slow-to-fade super-luminous supernovae that show relatively fast rise times and blue colours, which are incompatible with pair-instability models. Their late-time light-curve and spectral similarities to supernova 2007bi call the nature of that event into question. Our early spectra closely resemble typical fast-declining super-luminous supernovae(2,11,12), which are not powered by radio-activity. Modelling our observations with 10-16 solar masses of magnetar-energized(13,14) ejecta demonstrates the possibility of a common explosion mechanism. The lack of unambiguous nearby pair-instability events suggests that their local rate of occurrence is less than 6 x 10(-6) times that of the core-collapse rate.
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| 6. |
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| 7. |
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| 8. |
- Kankare, E., et al.
(author)
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Discovery of two new supernovae and an AGN outburst by PS1
- 2010
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Reports (other academic/artistic)abstract
- We report the discovery of two spectroscopically-confirmed Supernovae PS1-1000302 and PS1-1000303, and an AGN outburst PS1-1000305 in the Pan-STARRS1 "3Pi Faint galaxy supernova survey". PS1-1000302 was detected on June 12.4 UT (g=18.5) at 16:33:43.094 +54:42:04.18 (J2000) located 1.1" from the center of the host galaxy SDSS J163343.08+544205.4. PS1-1000303 was detected on June 14.3 UT (g=19.2) at 17:11:52.827 +43:36:57.06 (J2000) located 0.4" from the center of the host galaxy SDSS J171152.82+433656.7.
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| 9. |
- Pastorello, A., et al.
(author)
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Detection of PTF10cwr/CSS100313 on PS1 sky survey images and host galaxy identification
- 2010
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Reports (other academic/artistic)abstract
- We report that the transient PTF10cwr (Quimby et al. ATEL #2492), a.k.a. CSS100313:112547-084941 (Mahabal et al. ATel #2490), was also recovered on images from the Pan-STARRS Telescope #1 (PS1) as part of the PS1 3Pi survey (PS1-1000037). Magnitudes of i=18.96 and r=18.65 where measured with respect to SDSS sequence stars on March 12.45 and 13.49 UT respectively. Further photometry was gathered at the Liverpool Telescope on March 20.92 and March 23.00 UT.
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| 10. |
- Valenti, S., et al.
(author)
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Discovery of two new supernovae and a possible AGN/luminous SN IIn in the Pan-STARRS1 3Pi faint galaxy supernova survey
- 2010
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Reports (other academic/artistic)abstract
- report the discovery of two new supernovae and a possible AGN/luminous SN IIn in the Pan-STARRS 1 "3Pi Faint galaxy supernova survey". During the course of the PS1 3Pi sky survey, PS1-1000791 was detected on Aug 14.40 (UT) (Coord: 20:45:13.089 -06:56:11.090, J2000) at g=19.4 and detected again on Aug 19.33 at r=18.64 within 0.9 arcsec of the faint SDSS galaxy (J204513.14-065611.2). A spectrum of PS1-1000791 was obtained at the Nordic Optical Telescope (+ALFOSC+Gr4; range 350-950nm) on Aug 30.0 (UT).
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