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| 2. |
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| 3. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)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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| 4. |
- Sakatani, N., et al.
(författare)
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Anomalously porous boulders on (162173) Ryugu as primordial materials from its parent body
- 2021
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Ingår i: Nature Astronomy. - : Springer Nature. - 2397-3366. ; 5:8, s. 766-774
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Tidskriftsartikel (refereegranskat)abstract
- Planetesimals—the initial stage of the planetary formation process—are considered to be initially very porous aggregates of dusts1,2, and subsequent thermal and compaction processes reduce their porosity3. The Hayabusa2 spacecraft found that boulders on the surface of asteroid (162173) Ryugu have an average porosity of 30–50% (refs. 4,5,6), higher than meteorites but lower than cometary nuclei7, which are considered to be remnants of the original planetesimals8. Here, using high-resolution thermal and optical imaging of Ryugu’s surface, we discovered, on the floor of fresh small craters (<20 m in diameter), boulders with reflectance (~0.015) lower than the Ryugu average6 and porosity >70%, which is as high as in cometary bodies. The artificial crater formed by Hayabusa2’s impact experiment9 is similar to these craters in size but does not have such high-porosity boulders. Thus, we argue that the observed high porosity is intrinsic and not created by subsequent impact comminution and/or cracking. We propose that these boulders are the least processed material on Ryugu and represent remnants of porous planetesimals that did not undergo a high degree of heating and compaction3. Our multi-instrumental analysis suggests that fragments of the highly porous boulders are mixed within the surface regolith globally, implying that they might be captured within collected samples by touch-down operations10,11.
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| 5. |
- Sugita, S., et al.
(författare)
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The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes
- 2019
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Ingår i: Science. - : AAAS. - 0036-8075 .- 1095-9203. ; 364:6437
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Tidskriftsartikel (refereegranskat)abstract
- Asteroids fall to Earth in the form of meteorites, but these provide little information about their origins. The Japanese mission Hayabusa2 is designed to collect samples directly from the surface of an asteroid and return them to Earth for laboratory analysis. Three papers in this issue describe the Hayabusa2 team's study of the near-Earth carbonaceous asteroid 162173 Ryugu, at which the spacecraft arrived in June 2018 (see the Perspective by Wurm). Watanabeet al.measured the asteroid's mass, shape, and density, showing that it is a “rubble pile” of loose rocks, formed into a spinning-top shape during a prior period of rapid spin. They also identified suitable landing sites for sample collection. Kitazatoet al.used near-infrared spectroscopy to find ubiquitous hydrated minerals on the surface and compared Ryugu with known types of carbonaceous meteorite. Sugitaet al.describe Ryugu's geological features and surface colors and combined results from all three papers to constrain the asteroid's formation process. Ryugu probably formed by reaccumulation of rubble ejected by impact from a larger asteroid. These results provide necessary context to understand the samples collected by Hayabusa2, which are expected to arrive on Earth in December 2020.Science, this issue p.268, p.272, p.eaaw0422; see also p.230
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| 9. |
- Milillo, A., et al.
(författare)
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Investigating Mercury's Environment with the Two-Spacecraft BepiColombo Mission
- 2020
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Ingår i: Space Science Reviews. - : Springer Science and Business Media LLC. - 0038-6308 .- 1572-9672. ; 216:5
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Forskningsöversikt (refereegranskat)abstract
- The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well as their interactions with the solar wind, radiation, and interplanetary dust. Many scientific instruments onboard the two spacecraft will be completely, or partially devoted to study the near-space environment of Mercury as well as the complex processes that govern it. Many issues remain unsolved even after the MESSENGER mission that ended in 2015. The specific orbits of the two spacecraft, MPO and Mio, and the comprehensive scientific payload allow a wider range of scientific questions to be addressed than those that could be achieved by the individual instruments acting alone, or by previous missions. These joint observations are of key importance because many phenomena in Mercury's environment are highly temporally and spatially variable. Examples of possible coordinated observations are described in this article, analysing the required geometrical conditions, pointing, resolutions and operation timing of different BepiColombo instruments sensors.
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| 10. |
- Biskaborn, Boris K., et al.
(författare)
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Permafrost is warming at a global scale
- 2019
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Permafrost warming has the potential to amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007–2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39 ± 0.15 °C. Over the same period, discontinuous permafrost warmed by 0.20 ± 0.10 °C. Permafrost in mountains warmed by 0.19 ± 0.05 °C and in Antarctica by 0.37 ± 0.10 °C. Globally, permafrost temperature increased by 0.29 ± 0.12 °C. The observed trend follows the Arctic amplification of air temperature increase in the Northern Hemisphere. In the discontinuous zone, however, ground warming occurred due to increased snow thickness while air temperature remained statistically unchanged.
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| 11. |
- Ohara, N, et al.
(författare)
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Sequence analysis and variation of EBNA-1 in Epstein-Barr virus-related herpesvirus of cynomolgus monkey
- 2000
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Ingår i: Intervirology. - : S. Karger AG. - 0300-5526 .- 1423-0100. ; 43:2, s. 102-106
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Tidskriftsartikel (refereegranskat)abstract
- <i>Objectives:</i> The Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) is an important protein for immortalization and tumorigenesis of infected cells. EBNA-1 gene variants may play a role in tumorigenesis. We determined the nucleotide and amino acid (aa) sequences of EBNA-1 in EBV-related herpesviruses from cynomolgus monkeys (cynomolgus-EBV) which induced malignant lymphomas in its natural host and in rabbits, and compared them with sequences of EBV and other lymphocryptoviruses (LCVs). <i>Methods:</i> Polymerase chain reaction and direct sequencing methods were performed using extracted DNA from cynomolgus-EBV-infected cell lines. <i>Results:</i> The amino acid sequences of cynomolgus-EBV EBNA-1 from two cell lines (Si-IIA: 588 aa; Ts-B6: 619 aa) which are antigenically cross-reactive to human EBV EBNA-1 showed homology with human EBV (Si-IIA: 53%; Ts-B6: 58%) and other LCVs from baboons (54 and 52%) and rhesus monkeys (60 and 58%), especially in the C-terminal unique domain. Homology of the EBNA-1 sequence between Si-IIA and Ts-B6 was 92%. The sequence difference between EBV and the related LCVs was manifested mainly in the length of the internal repeat 3-corresponding region, which contains serine in the glycine/alanine repeat region of nonhuman LCVs. <i>Conclusion:</i> Sequence variation of cynomolgus-EBV EBNA-1 from different cell lines was observed. However, their sequences show a relatively high homology with human EBV and share the common features of EBNA-1 of EBV and other LCVs.
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| 12. |
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| 13. |
- Prokhorov, Dmitry, et al.
(författare)
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Can electron distribution functions be derived through the Sunyaev-Zel'dovich effect?
- 2011
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 529
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Tidskriftsartikel (refereegranskat)abstract
- Aims. Measurements of the Sunyaev-Zel'dovich (hereafter SZ) effect distortion of the cosmic microwave background provide methods to derive the gas pressure and temperature of galaxy clusters. Here we study the ability of SZ effect observations to derive the electron distribution function (DF) in massive galaxy clusters. Methods. Our calculations of the SZ effect include relativistic corrections considered within the framework of the Wright formalism and use a decomposition technique of electron DFs into Fourier series. Using multi-frequency measurements of the SZ effect, we find the solution of a linear system of equations that is used to derive the Fourier coefficients; we further analyze different frequency samples to decrease uncertainties in Fourier coefficient estimations. Results. We propose a method to derive DFs of electrons using SZ multi-frequency observations of massive galaxy clusters. We found that the best frequency sample to derive an electron DF includes high frequencies nu = 375, 600, 700, 857 GHz. We show that it is possible to distinguish a Juttner DF from a Maxwell-Bolzman DF as well as from a Juttner DF with the second electron population by means of SZ observations for the best frequency sample if the precision of SZ intensity measurements is less than 0.1%. We demonstrate by means of 3D hydrodynamic numerical simulations of a hot merging galaxy cluster that the morphologies of SZ intensity maps are different for frequencies nu = 375, 600, 700, 857 GHz. We stress that measurements of SZ intensities at these frequencies are a promising tool for studying electron distribution functions in galaxy clusters.
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| 14. |
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| 15. |
- Takahashi, H., et al.
(författare)
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A thermal-neutron detector with a phoswich system of LiCaAlF6 and BGO crystal scintillators onboard PoGOLite
- 2010
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Ingår i: 2010 IEEE Nuclear Science Symposium, Medical Imaging Conference, NSS/MIC 2010 and 17th International Workshop on Room-Temperature Semiconductor X-ray and Gamma-ray Detectors, RTSD 2010. ; , s. 32-37
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Konferensbidrag (refereegranskat)abstract
- To measure the flux of atmospheric neutrons and study the neutron contribution to the background of the main detector of the PoGOLite (Polarized Gamma-ray Observer) balloon-borne experiment, a thermal-neutron detector with a phoswich system of LiCaAlF6 (Eu) and BGO crystal scintillators is developed. The performance to separate thermal-neutron events from those of gamma-rays and charged particles is validated with 252Cf on ground. The detector is attached to the PoGOLite instrument and is launched in 2011 from the Esrange facility in the North of Sweden. Although the emission wavelength of the LiCaAlF6 (Ce) is 300 nm and overlaps with the absorption wavelength of the BGO, the phoswich capability of the LiCaAlF6 (Ce) with the BGO is also confirmed with installing a waveform shifter.
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| 16. |
- Umeki, K., et al.
(författare)
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Product distribution characteristics of pyrolysis and steam gasification of woody and agricultural biomass : Paper # 21
- 2008
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Ingår i: Air and Waste Management Association. - 9781605603797 - 9781605603797 ; , s. 578-588
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Konferensbidrag (refereegranskat)abstract
- A series of pyrolysis experiments were carried out with a batch reactor heated up by an electrical heater. Feedstocks used here were cedar, rice husk and rice straw. Gas evolution rates and product distributions were investigated. The following is the summary of results. Most gas was generated by pyrolysis within 60-120 seconds after introducing the sample into the reactor. Cedar pyrolyzed fastest among feedstock samples used in this study. Cedar generated very small amounts of char and significant amounts of tar compared with other feedstock samples. Carbon monoxide and hydrogen were the main products from pyrolysis of woody and agricultural biomass. Rice husk generated less hydrocarbon gases compared with other samples.
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| 17. |
- Yoshimi, N., et al.
(författare)
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Cerebrospinal fluid metabolomics identifies a key role of isocitrate dehydrogenase in bipolar disorder: evidence in support of mitochondrial dysfunction hypothesis
- 2016
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Ingår i: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 21:11, s. 1504-1510
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Tidskriftsartikel (refereegranskat)abstract
- Although evidence for mitochondrial dysfunction in the pathogenesis of bipolar disorder (BD) has been reported, the precise biological basis remains unknown, hampering the search for novel biomarkers. In this study, we performed metabolomics of cerebrospinal fluid (CSF) from male BD patients (n = 54) and age-matched male healthy controls (n = 40). Subsequently, postmortem brain analyses, genetic analyses, metabolomics of CSF samples from rats treated with lithium or valproic acid were also performed. After multivariate logistic regression, isocitric acid (isocitrate) levels were significantly higher in the CSF from BD patients than healthy controls. Furthermore, gene expression of two subtypes (IDH3A and IDH3B) of isocitrate dehydrogenase (IDH) in the dorsolateral prefrontal cortex from BD patients was significantly lower than that of controls, although the expression of other genes including, aconitase (ACO1, ACO2), IDH1, IDH2 and IDH3G, were not altered. Moreover, protein expression of IDH3A in the cerebellum from BD patients was higher than that of controls. Genetic analyses showed that IDH genes (IDH1, IDH2, IDH3A, IDH3B) and ACO genes (ACO1, ACO2) were not associated with BD. Chronic (4 weeks) treatment with lithium or valproic acid in rats did not alter CSF levels of isocitrate, and mRNA levels of Idh3a, Idh3b, Aco1 and Aco2 genes in the rat brain. These findings suggest that abnormality in the metabolism of isocitrate by IDH3A in the mitochondria plays a key role in the pathogenesis of BD, supporting the mitochondrial dysfunction hypothesis of BD. Therefore, IDH3 in the citric acid cycle could potentially be a novel therapeutic target for BD.
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| 20. |
- Hardi, F., et al.
(författare)
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Catalytic hydrothermal liquefaction of biomass with K2CO3 for production of gasification feedstock
- 2021
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Ingår i: Biofuels. - : Taylor and Francis Ltd.. - 1759-7269 .- 1759-7277. ; 12:2, s. 149-160
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Tidskriftsartikel (refereegranskat)abstract
- The introduction of alkali catalyst during hydrothermal liquefaction (HTL) improves conversion and allows the aqueous liquid product to be used as gasification feedstock. This study investigates the effect of reaction temperature (240–300°C), sawdust mass fraction (9.1–25%) and reaction time (0–60 min) during K2CO3-catalytic HTL of pine sawdust. The highest biomass conversion (75.2% carbon conversion and 83.0% mass conversion) was achieved at a reaction temperature of 270°C, 9.1% sawdust mass fraction and 30 min reaction time; meanwhile, the maximum aqueous product (AP) yield (69.0% carbon yield and 73.5% mass yield) was found at a reaction temperature of 300°C, 9.1% sawdust mass fraction and 60 min reaction time. Based on the main experimental results, models for carbon and mass yields of the products were developed according to face-centered central composite design using response surface methodology. Biomass conversion and product yields had a positive correlation with reaction temperature and reaction time, while they had an inverse correlation with sawdust mass fraction. Further investigation of the effects of biomass/water and biomass/K2CO3 ratios revealed that both high water loading and high K2CO3 loading enhanced conversion and AP yield.
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| 21. |
- Ishima, T., et al.
(författare)
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Abnormal gene expression of BDNF, but not BDNF-AS, in iPSC, neural stem cells and postmortem brain samples from bipolar disorder
- 2021
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Ingår i: Journal of Affective Disorders. - : Elsevier BV. - 0165-0327. ; 290, s. 61-64
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Tidskriftsartikel (refereegranskat)abstract
- Background: Brain-derived neurotrophic factor (BDNF) antisense RNA (BDNF-AS) was identified as naturally conserved non-coding antisense RNA that suppresses the transcription of BDNF. Methods: We measured the expression of BDNF mRNA and BDNF-AS mRNA in iPSC and NSC from bipolar disorder (BD) patients and healthy control subjects, and postmortem brain samples such as the corpus callosum, the Brodmann area (BA8), and BA46 from BD patients and age-and sex-matched controls. Results: The expression of BDNF mRNA in iPSC from BD patients (n = 6) was significantly lower than that of control subjects (n = 4) although the expression of BDNF mRNA in NSC from BD patients was significantly higher than that of control subjects. In contrast, there were no changes in the expression of BDNF-AS mRNA in both iPSC and NSC between two groups. The expression of BDNF mRNA in the BA46 from BD patients (n = 35) was significantly lower than that of controls (n = 34) although the expression of BDNF mRNA in the corpus callosum and BA8 was not different between two groups (n = 15). In contrast, there were no changes in expression of BDNF-AS mRNA in the three brain regions between two groups. Interestingly, there were significant positive correlations between BDNF mRNA expression and BDNF-AS mRNA expression in the postmortem brain samples. Limitations: Sample sizes are relatively low. Conclusions: Our data suggest that abnormalities in the expression of BDNF, but not BDNF-AS, play a role in the pathogenesis of BD.
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| 22. |
- Kawano, H., et al.
(författare)
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Pi 2 waves simultaneously observed by Cluster and CPMN ground-based magnetometers near the plasmapause
- 2011
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Ingår i: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 29:9, s. 1663-1672
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Tidskriftsartikel (refereegranskat)abstract
- We have analyzed an event on 14 February 2003 in which Cluster satellites and the CPMN ground magnetometer chain made simultaneous observations of a Pi 2 pulsation along the same meridian. Three of the four Cluster satellites were located outside the plasmasphere, while the other one was located within the plasmasphere. By combining the multipoint observations in space and the multipoint observations on the ground, we have obtained a detailed L-profile of the Pi 2 signatures, which has not been done in the past. In addition, we have used a method called Independent Component Analysis (ICA) to separate out other superposed waves with similar spectral components. The result shows that the wave phase of the Pi 2 was the same up to L similar to 3.9 (corresponding to the plasmasphere), became earlier up to L similar to 4.1 (corresponding to the plasmapause boundary layer), and showed a delaying tendency up to L similar to 5.9 (corresponding to the plasmatrough). This systematic phase pattern, obtained for the first time by a combination of a ground magnetometer chain and multisatellites along a magnetic meridian with the aid of ICA, supports the interpretation that a Pi 2 signal propagated from a farther source and reached the plasmasphere.
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| 23. |
- Prokhorov, Dmitry, et al.
(författare)
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A high-frequency study of the Sunyaev-Zel'dovich effect morphology in galaxy clusters
- 2011
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 416:1, s. 302-310
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Tidskriftsartikel (refereegranskat)abstract
- High-frequency, high-resolution imaging of the Sunyaev-Zel'dovich (SZ) effect is an important technique to study the complex structures of the atmospheres of merging galaxy clusters. Such observations are sensitive to the details of the electron spectrum. We show that the morphology of the SZ intensity maps in simulated galaxy clusters observed at 345, 600 and 857 GHz are significantly different because of SZ relativistic corrections. These differences can be revealed by high-resolution imaging instruments. We calculate relativistically corrected SZ intensity maps of a simulated, massive, merging galaxy cluster and of the massive, merging clusters 1E0657-558 (the Bullet cluster) and Abell 2219. The morphologies of the SZ intensity maps are remarkably different between 345 and 857 GHz for each merging cluster. We show that high-resolution imaging observations of the SZ intensity maps at these frequencies, obtainable with the LABOCA and HERSCHEL-SPIRE instruments, allow to fully exploit the astrophysical relevance of the predicted SZ morphological effect.
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| 24. |
- Prokhorov, Dmitry, et al.
(författare)
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A high-resolution study of the X-ray emission and Sunyaev-Zel'dovich effect in the Bullet cluster (1E 0657-56)
- 2012
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 426:3, s. 2291-2299
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Tidskriftsartikel (refereegranskat)abstract
- High-resolution imaging of the SunyaevZel'dovich (SZ) effect opens new possibilities for testing the presence of various high-energy particle populations in clusters of galaxies. A detailed X-ray analysis of the Bullet cluster (1E 0657-56) with Chandra has revealed the presence of additional X-ray spectral components beyond a simple, single-temperature plasma in its X-ray spectra. X-ray methods alone are insufficient to elucidate the origins of these spectral components. We show that the morphology and magnitude of the SZ effect at high frequencies are critically dependent upon the mechanism by which the additional X-ray spectra are created. We examine the differences between the predicted SZ effect emission maps at 600?GHz assuming the X-ray spectra are composed of thermal gas with a steep power-law index component and also thermal gas with a significant contribution of strongly heated gas. A two-temperature model with a hot (kT ? 3040?keV) second component is the most consistent with existing SZ data at high frequencies. However, significant morphological differences remain. High-angular-resolution SZ intensity maps at high frequencies in combination with deep X-ray data provide a new window into understanding particle energization processes in the hottest, massive merging galaxy clusters.
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| 25. |
- Prokhorov, Dmitry, et al.
(författare)
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Unveiling the 3D temperature structure of galaxy clusters by means of the thermal Sunyaev-Zel'dovich effect
- 2011
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 415:3, s. 2505-2512
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Tidskriftsartikel (refereegranskat)abstract
- The Sunyaev-Zel'dovich (hereinafter SZ) effect is a promising tool to derive the gas temperature of galaxy clusters. Approximation of a spherically symmetric gas distribution is usually used to determine the temperature structure of galaxy clusters, but this approximation cannot properly describe merging galaxy clusters. The methods used so far, which do not assume the spherically symmetric distribution, permit us to derive 2D temperature maps of merging galaxy clusters. In this paper, we propose a method to derive the standard temperature deviation and temperature variance along the line of sight, which permits us to analyse the 3D temperature structure of galaxy clusters by means of the thermal SZ effect. We also propose a method to reveal merger shock waves in galaxy clusters by analysing the presence of temperature inhomogeneities along the line of sight.
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