@article{SchmaelzlinMoralejoGersondeetal.2018, author = {Schm{\"a}lzlin, Elmar Gerd and Moralejo, Benito and Gersonde, Ingo and Schleusener, Johannes and Darvin, Maxim E. and Thiede, Gisela and Roth, Martin M.}, title = {Nonscanning large-area Raman imaging for ex vivo/in vivo skin cancer discrimination}, series = {Journal of biomedical optics}, volume = {23}, journal = {Journal of biomedical optics}, number = {10}, publisher = {SPIE}, address = {Bellingham}, issn = {1083-3668}, doi = {10.1117/1.JBO.23.10.105001}, pages = {11}, year = {2018}, abstract = {Imaging Raman spectroscopy can be used to identify cancerous tissue. Traditionally, a step-by-step scanning of the sample is applied to generate a Raman image, which, however, is too slow for routine examination of patients. By transferring the technique of integral field spectroscopy (IFS) from astronomy to Raman imaging, it becomes possible to record entire Raman images quickly within a single exposure, without the need for a tedious scanning procedure. An IFS-based Raman imaging setup is presented, which is capable of measuring skin ex vivo or in vivo. It is demonstrated how Raman images of healthy and cancerous skin biopsies were recorded and analyzed. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License.}, language = {en} } @article{MannRahmstorfKornhuberetal.2018, author = {Mann, Michael E. and Rahmstorf, Stefan and Kornhuber, Kai and Steinman, Byron A. and Miller, Sonya K. and Petri, Stefan and Coumou, Dim}, title = {Projected changes in persistent extreme summer weather events}, series = {Science Advances}, volume = {4}, journal = {Science Advances}, number = {10}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {2375-2548}, doi = {10.1126/sciadv.aat3272}, pages = {9}, year = {2018}, abstract = {Persistent episodes of extreme weather in the Northern Hemisphere summer have been associated with high-amplitude quasi-stationary atmospheric Rossby waves, with zonal wave numbers 6 to 8 resulting from the phenomenon of quasi-resonant amplification (QRA). A fingerprint for the occurrence of QRA can be defined in terms of the zonally averaged surface temperature field. Examining state-of-the-art [Coupled Model Intercomparison Project Phase 5 (CMIP5)] climate model projections, we find that QRA events are likely to increase by similar to 50\% this century under business-as-usual carbon emissions, but there is considerable variation among climate models. Some predict a near tripling of QRA events by the end of the century, while others predict a potential decrease. Models with amplified Arctic warming yield the most pronounced increase in QRA events. The projections are strongly dependent on assumptions regarding the nature of changes in radiative forcing associated with anthropogenic aerosols over the next century. One implication of our findings is that a reduction in midlatitude aerosol loading could actually lead to Arctic de-amplification this century, ameliorating potential increases in persistent extreme weather events.}, language = {en} } @article{RichterFoxWakkeretal.2018, author = {Richter, Philipp and Fox, Andrew J. and Wakker, Bart P. and Howk, J. Christopher and Lehner, Nicolas and Barger, Kathleen A. and Lockman, Felix J.}, title = {New constraints on the nature and origin of the leading arm of the magellanic stream}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {865}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, number = {2}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0004-637X}, doi = {10.3847/1538-4357/aadd0f}, pages = {16}, year = {2018}, abstract = {We present a new precision measurement of gas-phase abundances of S, O, N, Si, Fe, P, Al, Ca as well as molecular hydrogen (H-2) in the Leading Arm (region II, LA II) of the Magellanic Stream (MS) toward the Seyfert galaxy NGC 3783. The results are based on high-quality archival ultraviolet/optical/radio data from various different instruments (HST/STIS, FUSE, AAT, GBT, GB140 ft, ATCA). Our study updates previous results from lower-resolution data and provides for the first time a self-consistent component model of the complex multiphase absorber, delivering important constraints on the nature and origin of LA II. We derive a uniform, moderate a abundance in the two main absorber groups at +245 and +190 km s(-1) of alpha/H = 0.30 +/- 0.05 solar, a low nitrogen abundance of N/H = 0.05 +/- 0.01 solar, and a high dust content with substantial dust depletion values for Si, Fe, Al, and Ca. These a, N, and dust abundances in LA II are similar to those observed in the Small Magellanic Cloud (SMC). From the analysis of the H2 absorption, we determine a high thermal pressure of P/k approximate to 1680 K cm(-3) in LA II, in line with the idea that LA II is located in the inner Milky Way halo at a z-height of < 20 kpc, where it hydrodynamically interacts with the ambient hot coronal gas. Our study supports a scenario in which LA II stems from the breakup of a metal- and dust-enriched progenitor cloud that was recently (200-500 Myr ago) stripped from the SMC.}, language = {en} } @article{BrueggerGobetSigletal.2018, author = {Br{\"u}gger, Sandra Olivia and Gobet, Erika and Sigl, Michael and Osmont, Dimitri and Papina, Tatyana and Rudaya, Natalia and Schwikowski-Gigar, Margit and Tinner, Willy}, title = {Ice records provide new insights into climatic vulnerability of Central Asian forest and steppe communities}, series = {Global and planetary change}, volume = {169}, journal = {Global and planetary change}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0921-8181}, doi = {10.1016/j.gloplacha.2018.07.010}, pages = {188 -- 201}, year = {2018}, abstract = {Forest and steppe communities in the Altai region of Central Asia are threatened by changing climate and anthropogenic pressure. Specifically, increasing drought and grazing pressure may cause collapses of moisture-demanding plant communities, particularly forests. Knowledge about past vegetation and fire responses to climate and land use changes may help anticipating future ecosystem risks, given that it has the potential to disclose mechanisms and processes that govern ecosystem vulnerability. We present a unique paleoecological record from the high-alpine Tsambagarav glacier in the Mongolian Altai that provides novel large-scale information on vegetation, fire and pollution with an exceptional temporal resolution and precision. Our palynological record identifies several late-Holocene boreal forest expansions, contractions and subsequent recoveries. Maximum forest expansions occurred at 3000-2800 BC, 2400-2100 BC, and 1900-1800 BC. After 1800 BC mixed boreal forest communities irrecoverably declined. Fires reached a maximum at 1600 BC, 200 years after the final forest collapse. Our multiproxy data suggest that burning peaked in response to dead biomass accumulation resulting from forest diebacks. Vegetation and fire regimes partly decoupled from climate after 1700 AD, when atmospheric industrial pollution began, and land use intensified. We conclude that moisture availability was more important than temperature for past vegetation dynamics, in particular for forest loss and steppe expansion. The past Mongolian Altai evidence implies that in the future forests of the Russian Altai may collapse in response to reduced moisture availability.}, language = {en} } @article{RamiaramanantsoaRatnasingamShenaretal.2018, author = {Ramiaramanantsoa, Tahina and Ratnasingam, Rathish and Shenar, Tomer and Moffat, Anthony F. J. and Rogers, Tamara M. and Popowicz, Adam and Kuschnig, Rainer and Pigulski, Andrzej and Handler, Gerald and Wade, Gregg A. and Zwintz, Konstanze and Weiss, Werner W.}, title = {A BRITE view on the massive O-type supergiant V973 Scorpii}, series = {Monthly notices of the Royal Astronomical Society}, volume = {480}, journal = {Monthly notices of the Royal Astronomical Society}, number = {1}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0035-8711}, doi = {10.1093/mnras/sty1897}, pages = {972 -- 986}, year = {2018}, abstract = {Stochastically triggered photospheric light variations reaching similar to 40 mmag peak-to-valley amplitudes have been detected in the O8 Iaf supergiant V973 Scorpii as the outcome of 2 months of high-precision time-resolved photometric observations with the BRIght Target Explorer (BRITE) nanosatellites. The amplitude spectrum of the time series photometry exhibits a pronounced broad bump in the low-frequency regime (less than or similar to 0.9 d(-1)) where several prominent frequencies are detected. A time-frequency analysis of the observations reveals typical mode lifetimes of the order of 5-10 d. The overall features of the observed brightness amplitude spectrum of V973 Sco match well with those extrapolated from two-dimensional hydrodynamical simulations of convectively driven internal gravity waves randomly excited from deep in the convective cores of massive stars. An alternative or additional possible source of excitation from a sub-surface convection zone needs to be explored in future theoretical investigations.}, language = {en} } @article{RychkovAltafim2018, author = {Rychkov, Dmitry and Altafim, Ruy Alberto Pisani}, title = {Template-based fluoroethylenepropylene ferroelectrets with enhanced thermal stability of piezoelectricity}, series = {Journal of applied physics}, volume = {124}, journal = {Journal of applied physics}, number = {17}, publisher = {American Institute of Physics}, address = {Melville}, issn = {0021-8979}, doi = {10.1063/1.5041374}, pages = {5}, year = {2018}, abstract = {In ferroelectrets, the piezoelectricity stems from the charges of both polarities trapped on the inner surfaces of the cavities in the material, so that its thermal stability is defined by the stability of the respective charges. In the present work, a template-based lamination technique has been employed to fabricate tubular-channel ferroelectrets from fluoroethylenepropylene (FEP) films. It has been shown that the piezoelectricity in FEP ferroelectrets decays at relatively low temperatures due to the inherently lower thermal stability of the positive charge. In order to improve charge trapping, we have treated both FEP films and inner surfaces of the ferroelectret cavities with titanium-tetrachloride vapor, using the atomic-layer-deposition technique. Using surface-potential-decay measurements on FEP films, we have found that the charge-decay curves shift by more than 100 degrees C to the higher temperatures as a result of the surface treatment. Direct measurements of piezoelectric d(33) coefficients as a function of temperature have shown that the piezoelectric stability is likewise improved with the d(33)-decay curves shifted by 60 degrees C to the right. The improvement of electret/ferroelectret properties can be attributed to the formation of the deeper traps on the chemically modified FEP surface. SEM micrographs and EDS analysis reveal island-like structures with titanium- and oxygen-containing species that can be responsible for the deeper trapping of the electret charges. Published by AIP Publishing.}, language = {en} } @article{JonscherFlemmingSchmittetal.2018, author = {Jonscher, Ernst and Flemming, Sven and Schmitt, Marius and Sabitzki, Ricarda and Reichard, Nick and Birnbaum, Jakob and Bergmann, B{\"a}rbel and H{\"o}hn, Katharina and Spielmann, Tobias}, title = {PfVPS45 Is Required for Host Cell Cytosol Uptake by Malaria Blood Stage Parasites}, series = {Cell host \& microbe}, volume = {25}, journal = {Cell host \& microbe}, number = {1}, publisher = {Cell Press}, address = {Cambridge}, issn = {1931-3128}, doi = {10.1016/j.chom.2018.11.010}, pages = {166 -- 173}, year = {2018}, abstract = {During development in human erythrocytes, the malaria parasite Plasmodium falciparum internalizes a large part of the cellular content of the host cell. The internalized cytosol, consisting largely of hemoglobin, is transported to the parasite's food vacuole where it is degraded, providing nutrients and space for growth. This host cell cytosol uptake (HCCU) is crucial for parasite survival but the parasite proteins mediating this process remain obscure. Here, we identify P. falciparum VPS45 as an essential factor in HCCU. Conditional inactivation of PfVPS45 led to an accumulation of host cell cytosol-filled vesicles within the parasite and inhibited the delivery of hemoglobin to the parasite's digestive vacuole, resulting in arrested parasite growth. A proportion of these HCCU vesicle intermediates was positive for phosphatidylinositol 3-phosphate, suggesting endosomal characteristics. Thus PfVPS45 provides insight into the elusive machinery of the ingestion pathway in a parasite that contains an endolysosomal system heavily repurposed for protein secretion.}, language = {en} } @misc{LewandowskyCowtanRisbeyetal.2018, author = {Lewandowsky, Stephan and Cowtan, Kevin and Risbey, James S. and Mann, Michael E. and Steinman, Byron A. and Oreskes, Naomi and Rahmstorf, Stefan}, title = {The 'pause' in global warming in historical context}, series = {Environmental research letters}, volume = {13}, journal = {Environmental research letters}, number = {12}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {1748-9326}, doi = {10.1088/1748-9326/aaf372}, pages = {25}, year = {2018}, abstract = {We review the evidence for a putative early 21st-century divergence between global mean surface temperature (GMST) and Coupled Model Intercomparison Project Phase 5 (CMIP5) projections. We provide a systematic comparison between temperatures and projections using historical versions of GMST products and historical versions of model projections that existed at the times when claims about a divergence were made. The comparisons are conducted with a variety of statistical techniques that correct for problems in previous work, including using continuous trends and a Monte Carlo approach to simulate internal variability. The results show that there is no robust statistical evidence for a divergence between models and observations. The impression of a divergence early in the 21st century was caused by various biases in model interpretation and in the observations, and was unsupported by robust statistics.}, language = {en} } @article{Goychuk2018, author = {Goychuk, Igor}, title = {Viscoelastic subdiffusion in a random Gaussian environment}, series = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, volume = {20}, journal = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, number = {37}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9076}, doi = {10.1039/c8cp05238g}, pages = {24140 -- 24155}, year = {2018}, abstract = {Viscoelastic subdiffusion governed by a fractional Langevin equation is studied numerically in a random Gaussian environment modeled by stationary Gaussian potentials with decaying spatial correlations. This anomalous diffusion is archetypal for living cells, where cytoplasm is known to be viscoelastic and a spatial disorder also naturally emerges. We obtain some first important insights into it within a model one-dimensional study. Two basic types of potential correlations are studied: short-range exponentially decaying and algebraically slow decaying with an infinite correlation length, both for a moderate (several kBT, in the units of thermal energy), and strong (5-10kBT) disorder. For a moderate disorder, it is shown that on the ensemble level viscoelastic subdiffusion can easily overcome the medium's disorder. Asymptotically, it is not distinguishable from the disorder-free subdiffusion. However, a strong scatter in single-trajectory averages is nevertheless seen even for a moderate disorder. It features a weak ergodicity breaking, which occurs on a very long yet transient time scale. Furthermore, for a strong disorder, a very long transient regime of logarithmic, Sinai-type diffusion emerges. It can last longer and be faster in the absolute terms for weakly decaying correlations as compared with the short-range correlations. Residence time distributions in a finite spatial domain are of a generalized log-normal type and are reminiscent also of a stretched exponential distribution. They can be easily confused for power-law distributions in view of the observed weak ergodicity breaking. This suggests a revision of some experimental data and their interpretation.}, language = {en} } @misc{RisbeyLewandowskyCowtanetal.2018, author = {Risbey, James S. and Lewandowsky, Stephan and Cowtan, Kevin and Oreskes, Naomi and Rahmstorf, Stefan and Jokim{\"a}ki, Ari and Foster, Grant}, title = {A fluctuation in surface temperature in historical context}, series = {Environmental research letters}, volume = {13}, journal = {Environmental research letters}, number = {12}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {1748-9326}, doi = {10.1088/1748-9326/aaf342}, pages = {23}, year = {2018}, abstract = {This work reviews the literature on an alleged global warming 'pause' in global mean surface temperature (GMST) to determine how it has been defined, what time intervals are used to characterise it, what data are used to measure it, and what methods used to assess it. We test for 'pauses', both in the normally understood meaning of the term to mean no warming trend, as well as for a 'pause' defined as a substantially slower trend in GMST. The tests are carried out with the historical versions of GMST that existed for each pause-interval tested, and with current versions of each of the GMST datasets. The tests are conducted following the common (but questionable) practice of breaking the linear fit at the start of the trend interval ('broken' trends), and also with trends that are continuous with the data bordering the trend interval. We also compare results when appropriate allowance is made for the selection bias problem. The results show that there is little or no statistical evidence for a lack of trend or slower trend in GMST using either the historical data or the current data. The perception that there was a 'pause' in GMST was bolstered by earlier biases in the data in combination with incomplete statistical testing.}, language = {en} }