@article{15205, abstract = {Magnetars are neutron stars with ultrastrong magnetic fields, which can be observed in x-rays. Polarization measurements could provide information on their magnetic fields and surface properties. We observed polarized x-rays from the magnetar 4U 0142+61 using the Imaging X-ray Polarimetry Explorer and found a linear polarization degree of 13.5 ± 0.8% averaged over the 2– to 8–kilo–electron volt band. The polarization changes with energy: The degree is 15.0 ± 1.0% at 2 to 4 kilo–electron volts, drops below the instrumental sensitivity ~4 to 5 kilo–electron volts, and rises to 35.2 ± 7.1% at 5.5 to 8 kilo–electron volts. The polarization angle also changes by 90° at ~4 to 5 kilo–electron volts. These results are consistent with a model in which thermal radiation from the magnetar surface is reprocessed by scattering off charged particles in the magnetosphere.}, author = {Taverna, Roberto and Turolla, Roberto and Muleri, Fabio and Heyl, Jeremy and Zane, Silvia and Baldini, Luca and González-Caniulef, Denis and Bachetti, Matteo and Rankin, John and Caiazzo, Ilaria and Di Lalla, Niccolò and Doroshenko, Victor and Errando, Manel and Gau, Ephraim and Kırmızıbayrak, Demet and Krawczynski, Henric and Negro, Michela and Ng, Mason and Omodei, Nicola and Possenti, Andrea and Tamagawa, Toru and Uchiyama, Keisuke and Weisskopf, Martin C. and Agudo, Ivan and Antonelli, Lucio A. and Baumgartner, Wayne H. and Bellazzini, Ronaldo and Bianchi, Stefano and Bongiorno, Stephen D. and Bonino, Raffaella and Brez, Alessandro and Bucciantini, Niccolò and Capitanio, Fiamma and Castellano, Simone and Cavazzuti, Elisabetta and Ciprini, Stefano and Costa, Enrico and De Rosa, Alessandra and Del Monte, Ettore and Di Gesu, Laura and Di Marco, Alessandro and Donnarumma, Immacolata and Dovčiak, Michal and Ehlert, Steven R. and Enoto, Teruaki and Evangelista, Yuri and Fabiani, Sergio and Ferrazzoli, Riccardo and Garcia, Javier A. and Gunji, Shuichi and Hayashida, Kiyoshi and Iwakiri, Wataru and Jorstad, Svetlana G. and Karas, Vladimir and Kitaguchi, Takao and Kolodziejczak, Jeffery J. and La Monaca, Fabio and Latronico, Luca and Liodakis, Ioannis and Maldera, Simone and Manfreda, Alberto and Marin, Frédéric and Marinucci, Andrea and Marscher, Alan P. and Marshall, Herman L. and Matt, Giorgio and Mitsuishi, Ikuyuki and Mizuno, Tsunefumi and Ng, Stephen C.-Y. and O’Dell, Stephen L. and Oppedisano, Chiara and Papitto, Alessandro and Pavlov, George G. and Peirson, Abel L. and Perri, Matteo and Pesce-Rollins, Melissa and Pilia, Maura and Poutanen, Juri and Puccetti, Simonetta and Ramsey, Brian D. and Ratheesh, Ajay and Romani, Roger W. and Sgrò, Carmelo and Slane, Patrick and Soffitta, Paolo and Spandre, Gloria and Tavecchio, Fabrizio and Tawara, Yuzuru and Tennant, Allyn F. and Thomas, Nicholas E. and Tombesi, Francesco and Trois, Alessio and Tsygankov, Sergey S. and Vink, Jacco and Wu, Kinwah and Xie, Fei}, issn = {1095-9203}, journal = {Science}, keywords = {Multidisciplinary}, number = {6620}, pages = {646--650}, publisher = {American Association for the Advancement of Science}, title = {{Polarized x-rays from a magnetar}}, doi = {10.1126/science.add0080}, volume = {378}, year = {2022}, } @article{15206, abstract = {We use the Relativistic Precession Model (RPM) and quasi-periodic oscillation (QPO) observations from the Rossi X-ray Timing Explorer to derive constraints on the properties of the black holes that power these sources and to test general relativity (GR) in the strong field regime. We build upon past techniques by using pairs of simultaneously measured QPOs, rather than triplets, and by including characteristic frequencies from the broad noise components of the power spectra in our fits. We find the inclusion of these broad noise components causes an overestimate in masses and underestimate in spins compared to values derived independently from optical spectra. We extend the underlying space-time metric to constrain potential deviations from the predictions of GR for astrophysical black holes. To do this, we modify the RPM model to a Kerr–Newman–deSitter space-time and model changes in the radial, ecliptic, and vertical frequencies. We compare our models with X-ray data of XTE J1550-564 and GRO J1655-40 using robust statistical techniques to constrain the parameters of the black holes and the deviations from GR. For both sources, using QPO and characteristic frequency data, we constrain particular deviations from GR to be less than one part per thousand.}, author = {Rink, Katherine and Caiazzo, Ilaria and Heyl, Jeremy}, issn = {1365-2966}, journal = {Monthly Notices of the Royal Astronomical Society}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {1}, pages = {1389--1397}, publisher = {Oxford University Press}, title = {{Testing general relativity using quasi-periodic oscillations from X-ray black holes: XTE J1550-564 and GRO J1655-40}}, doi = {10.1093/mnras/stac2740}, volume = {517}, year = {2022}, } @article{15207, abstract = {Of more than a thousand known cataclysmic variables (CVs), where a white dwarf is accreting from a hydrogen-rich star, only a dozen have orbital periods below 75 minutes1,2,3,4,5,6,7,8,9. One way to achieve these short periods requires the donor star to have undergone substantial nuclear evolution before interacting with the white dwarf10,11,12,13,14, and it is expected that these objects will transition to helium accretion. These transitional CVs have been proposed as progenitors of helium CVs13,14,15,16,17,18. However, no known transitional CV is expected to reach an orbital period short enough to account for most of the helium CV population, leaving the role of this evolutionary pathway unclear. Here we report observations of ZTF J1813+4251, a 51-minute-orbital-period, fully eclipsing binary system consisting of a star with a temperature comparable to that of the Sun but a density 100 times greater owing to its helium-rich composition, accreting onto a white dwarf. Phase-resolved spectra, multi-band light curves and the broadband spectral energy distribution allow us to obtain precise and robust constraints on the masses, radii and temperatures of both components. Evolutionary modelling shows that ZTF J1813+4251 is destined to become a helium CV binary, reaching an orbital period under 20 minutes, rendering ZTF J1813+4251 a previously missing link between helium CV binaries and hydrogen-rich CVs.}, author = {Burdge, Kevin B. and El-Badry, Kareem and Marsh, Thomas R. and Rappaport, Saul and Brown, Warren R. and Caiazzo, Ilaria and Chakrabarty, Deepto and Dhillon, V. S. and Fuller, Jim and Gänsicke, Boris T. and Graham, Matthew J. and Kara, Erin and Kulkarni, S. R. and Littlefair, S. P. and Mróz, Przemek and Rodríguez-Gil, Pablo and Roestel, Jan van and Simcoe, Robert A. and Bellm, Eric C. and Drake, Andrew J. and Dekany, Richard G. and Groom, Steven L. and Laher, Russ R. and Masci, Frank J. and Riddle, Reed and Smith, Roger M. and Prince, Thomas A.}, issn = {1476-4687}, journal = {Nature}, number = {7932}, pages = {467--471}, publisher = {Springer Nature}, title = {{A dense 0.1-solar-mass star in a 51-minute-orbital-period eclipsing binary}}, doi = {10.1038/s41586-022-05195-x}, volume = {610}, year = {2022}, } @article{15208, abstract = {This year, a new era of observations of compact objects in X-ray polarization is commencing. Among the key targets for the Imaging X-ray Polarimetry Explorer mission are the magnetars 4U 0142+61 and 1RXS J170849.0-400910. Here, we present detailed predictions of the expected polarization from these sources that incorporate realistic models of emission physics at the surface (gaseous or condensed), the temperature distribution on the surface, general relativity, quantum electrodynamics, and scattering in the magnetosphere, accounting for the broad-band spectral energy distribution from below 1 keV to nearly 100 keV. We find that either atmospheres or condensed surfaces can account for the emission at a few keV. In both cases, either a small hot polar cap or scattering is required to account for the emission at 5–10 keV and, above 10 keV, scattering by a hard population of electrons can account for the rising power in the hard X-rays observed in many magnetars in quiescence. Although these different scenarios result in very similar spectral energy distributions, they generate dramatically different polarization signatures from 2 to 8 keV, which is the range of sensitivity of the Imaging X-ray Polarimetry Explorer. Observations of these sources in X-ray polarization will therefore probe the emission from magnetars in an essentially new way.}, author = {Caiazzo, Ilaria and González-Caniulef, Denis and Heyl, Jeremy and Fernández, Rodrigo}, issn = {1365-2966}, journal = {Monthly Notices of the Royal Astronomical Society}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {4}, pages = {5024--5034}, publisher = {Oxford University Press}, title = {{Probing magnetar emission mechanisms with X-ray spectropolarimetry}}, doi = {10.1093/mnras/stac1571}, volume = {514}, year = {2022}, } @article{15209, abstract = {It has been recently suggested that white dwarfs generate magnetic fields in a process analogous to the Earth. The crystallization of the core creates a compositional inversion that drives convection, and combined with rotation, this can sustain a magnetic dynamo. We reanalyse the dynamo mechanism, arising from the slow crystallization of the core, and find convective turnover times tconv of weeks to months – longer by orders of magnitude than previously thought. With white dwarf spin periods P ≪ tconv, crystallization-driven dynamos are almost always in the fast-rotating regime, where the magnetic field B is at least in equipartition with the convective motion and is possibly further enhanced by a factor of B ∝ (tconv/P)1/2, depending on the assumed dynamo scaling law. We track the growth of the crystallized core using MESA and compute the magnetic field B(Teff) as a function of the white dwarf’s effective temperature Teff. We compare this prediction with observations and show that crystallization-driven dynamos can explain some – but not all – of the ∼MG magnetic fields measured for single white dwarfs, as well as the stronger fields measured for white dwarfs in cataclysmic variables, which were spun up by mass accretion to short P. Our B(Teff) curves might also explain the clustering of white dwarfs with Balmer emission lines around Teff ≈ 7500 K.}, author = {Ginzburg, Sivan and Fuller, Jim and Kawka, Adela and Caiazzo, Ilaria}, issn = {1365-2966}, journal = {Monthly Notices of the Royal Astronomical Society}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {3}, pages = {4111--4119}, publisher = {Oxford University Press}, title = {{Slow convection and fast rotation in crystallization-driven white dwarf dynamos}}, doi = {10.1093/mnras/stac1363}, volume = {514}, year = {2022}, } @article{15210, abstract = {The maximum mass of a star that can produce a white dwarf (WD) is an important astrophysical quantity. One of the best approaches to establishing this limit is to search for WDs in young star clusters in which only massive stars have had time to evolve and where the mass of the progenitor can be established from the cooling time of the WD together with the age of the cluster. Searches in young Milky Way clusters have not thus far yielded WD members more massive than about 1.1 M⊙, well below the Chandrasekhar mass of 1.38 M⊙, nor progenitors with masses in excess of about 6 M⊙. However, the hunt for potentially massive WDs that escaped their cluster environs is yielding interesting candidates. To expand the cluster sample further, we used HST to survey four young and massive star clusters in the Magellanic Clouds for bright WDs that could have evolved from stars as massive as 10 M⊙. We located five potential WD candidates in the oldest of the four clusters examined, the first extragalactic single WDs thus far discovered. As these hot WDs are very faint at optical wavelengths, final confirmation will likely have to await spectroscopy with 30 m class telescopes.}, author = {Richer, Harvey B. and Cohen, Roger E. and Heyl, Jeremy and Kalirai, Jason and Caiazzo, Ilaria and Correnti, Matteo and Cummings, Jeffrey and Goudfrooij, Paul and Hansen, Bradley M. S. and Peeples, Molly and Sabbi, Elena and Tremblay, Pier-Emmanuel and Williams, Benjamin}, issn = {2041-8213}, journal = {The Astrophysical Journal Letters}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {2}, publisher = {American Astronomical Society}, title = {{When do stars go boom?}}, doi = {10.3847/2041-8213/ac6585}, volume = {931}, year = {2022}, } @article{15211, abstract = {Over a dozen millisecond pulsars are ablating low-mass companions in close binary systems. In the original ‘black widow’, the eight-hour orbital period eclipsing pulsar PSR J1959+2048 (PSR B1957+20)1, high-energy emission originating from the pulsar2 is irradiating and may eventually destroy3 a low-mass companion. These systems are not only physical laboratories that reveal the interesting results of exposing a close companion star to the relativistic energy output of a pulsar, but are also believed to harbour some of the most massive neutron stars4, allowing for robust tests of the neutron star equation of state. Here we report observations of ZTF J1406+1222, a wide hierarchical triple hosting a 62-minute orbital period black widow candidate, the optical flux of which varies by a factor of more than ten. ZTF J1406+1222 pushes the boundaries of evolutionary models5, falling below the 80-minute minimum orbital period of hydrogen-rich systems. The wide tertiary companion is a rare low-metallicity cool subdwarf star, and the system has a Galactic halo orbit consistent with passing near the Galactic Centre, making it a probe of formation channels, neutron star kick physics6 and binary evolution.}, author = {Burdge, Kevin B. and Marsh, Thomas R. and Fuller, Jim and Bellm, Eric C. and Caiazzo, Ilaria and Chakrabarty, Deepto and Coughlin, Michael W. and De, Kishalay and Dhillon, V. S. and Graham, Matthew J. and Rodríguez-Gil, Pablo and Jaodand, Amruta D. and Kaplan, David L. and Kara, Erin and Kong, Albert K. H. and Kulkarni, S. R. and Li, Kwan-Lok and Littlefair, S. P. and Majid, Walid A. and Mróz, Przemek and Pearlman, Aaron B. and Phinney, E. S. and Roestel, Jan van and Simcoe, Robert A. and Andreoni, Igor and Drake, Andrew J. and Dekany, Richard G. and Duev, Dmitry A. and Kool, Erik C. and Mahabal, Ashish A. and Medford, Michael S. and Riddle, Reed and Prince, Thomas A.}, issn = {1476-4687}, journal = {Nature}, keywords = {Multidisciplinary}, number = {7908}, pages = {41--45}, publisher = {Springer Nature}, title = {{A 62-minute orbital period black widow binary in a wide hierarchical triple}}, doi = {10.1038/s41586-022-04551-1}, volume = {605}, year = {2022}, } @article{15212, abstract = {We determine the distribution of cooling ages of massive Gaia EDR3 white dwarfs identified with over 90 per cent probability within 200 pc and with mass in the range 0.95–1.25 M⊙. Using three sets of publicly available models, we consider sub-samples of these white dwarfs sorted into three equally spaced mass bins. Under the assumption of a constant white dwarf formation rate, we find an excess of white dwarfs, both along the Q branch and below it, corresponding respectively to stars that are in the process of freezing and those that are completely frozen. We compare the cooling age distributions for each of these bins to the recently determined time-varying star formation rate of Gaia DR2 main sequence stars. For white dwarfs in the two lightest mass bins, spanning the mass range 0.95–1.15 M⊙, we find that the cumulative cooling age distribution is statistically consistent with the expectation from the star formation rate. For white dwarfs in the heaviest mass bin, 1.15–1.25 M⊙, we find that their cumulative distribution is inconsistent with the star formation rate for all of the models considered; instead, we find that their cooling age distribution is well fitted by a linear combination of the distribution expected for single stellar evolution products and the distribution expected for double white dwarf merger products when approximately 40–50 per cent of the 1.15–1.25 M⊙ white dwarfs that formed over the past 4 Gyr are produced through double white dwarf mergers.}, author = {Fleury, Leesa and Caiazzo, Ilaria and Heyl, Jeremy}, issn = {1365-2966}, journal = {Monthly Notices of the Royal Astronomical Society}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {4}, pages = {5984--5993}, publisher = {Oxford University Press}, title = {{The cooling of massive white dwarfs from Gaia EDR3}}, doi = {10.1093/mnras/stac458}, volume = {511}, year = {2022}, } @article{15213, abstract = {We searched through the entire Gaia EDR3 candidate white dwarf catalog for stars with proper motions and positions that are consistent with them having escaped from the Alpha Persei cluster within the past 81 Myr, the age of the cluster. In this search we found five candidate white dwarf escapees from Alpha Persei and obtained spectra for all of them. We confirm that three are massive white dwarfs sufficiently young to have originated in the cluster. All these are more massive than any white dwarf previously associated with a cluster using Gaia astrometry, and possess some of the most massive progenitors. In particular, the white dwarf Gaia EDR3 4395978097863572, which lies within 25 pc of the cluster center, has a mass of about 1.20 solar masses and evolved from an 8.5 solar-mass star, pushing the upper limit for white dwarf formation from a single massive star, while still leaving a substantial gap between the resulting white dwarf mass and the Chandrasekhar mass.}, author = {Miller, David R. and Caiazzo, Ilaria and Heyl, Jeremy and Richer, Harvey B. and Tremblay, Pier-Emmanuel}, issn = {2041-8213}, journal = {The Astrophysical Journal Letters}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {2}, publisher = {American Astronomical Society}, title = {{The ultramassive white dwarfs of the Alpha Persei cluster}}, doi = {10.3847/2041-8213/ac50a5}, volume = {926}, year = {2022}, } @article{15214, abstract = {We search through an eight million cubic parsec volume surrounding the Pleiades star cluster and the Sun to identify both the current and past members of the Pleiades cluster within the Gaia EDR3 data set. We find nearly 1300 current cluster members and 289 former cluster candidates. Many of these candidates lie well in front of or behind the cluster from our point of view, so formerly they were considered cluster members, but their parallaxes put them more than 10 pc from the center of the cluster today. Over the past 100 Myr we estimate that the cluster has lost twenty percent of its mass including two massive white dwarf stars and the α2 Canum Venaticorum type variable star, 41 Tau. All three white dwarfs associated with the cluster are massive (1.01–1.06 M⊙) and have progenitors with main-sequence masses of about six solar masses. Although we did not associate any giant stars with the cluster, the cooling time of the oldest white dwarf of 60 Myr gives a firm lower limit on the age of the cluster.}, author = {Heyl, Jeremy and Caiazzo, Ilaria and Richer, Harvey B.}, issn = {1538-4357}, journal = {The Astrophysical Journal}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {2}, publisher = {American Astronomical Society}, title = {{Reconstructing the Pleiades with Gaia EDR3}}, doi = {10.3847/1538-4357/ac45fc}, volume = {926}, year = {2022}, } @article{15268, abstract = {Apolipoprotein A‐I (apoA‐I) has a key function in the reverse cholesterol transport. However, aggregation of apoA‐I single point mutants can lead to hereditary amyloid pathology. Although several studies have tackled the biophysical and structural consequences introduced by these mutations, there is little information addressing the relationship between the evolutionary and structural features that contribute to the amyloid behavior of apoA‐I. We combined evolutionary studies, in silico mutagenesis and molecular dynamics (MD) simulations to provide a comprehensive analysis of the conservation and pathogenic role of the aggregation‐prone regions (APRs) present in apoA‐I. Sequence analysis demonstrated that among the four amyloidogenic regions described for human apoA‐I, only two (APR1 and APR4) are evolutionary conserved across different species of Sarcopterygii. Moreover, stability analysis carried out with the FoldX engine showed that APR1 contributes to the marginal stability of apoA‐I. Structural properties of full‐length apoA‐I models suggest that aggregation is avoided by placing APRs into highly packed and rigid portions of its native fold. Compared to silent variants extracted from the gnomAD database, the thermodynamic and pathogenic impact of amyloid mutations showed evidence of a higher destabilizing effect. MD simulations of the amyloid variant G26R evidenced the partial unfolding of the alpha‐helix bundle with the concomitant exposure of APR1 to the solvent, suggesting an insight into the early steps involved in its aggregation. Our findings highlight APR1 as a relevant component for apoA‐I structural integrity and emphasize a destabilizing effect of amyloid variants that leads to the exposure of this region.}, author = {Gisonno, Romina A. and Masson, Tomas and Ramella, Nahuel A. and Barrera, Exequiel E. and Romanowski, Víctor and Tricerri, M. Alejandra}, issn = {1097-0134}, journal = {Proteins: Structure, Function, and Bioinformatics}, keywords = {Molecular Biology, Biochemistry, Structural Biology}, number = {1}, pages = {258--269}, publisher = {Wiley}, title = {{Evolutionary and structural constraints influencing apolipoprotein A‐I amyloid behavior}}, doi = {10.1002/prot.26217}, volume = {90}, year = {2022}, } @article{10566, abstract = {A versatile, scalable, room temperature and surfactant-free route for the synthesis of metal chalcogenide nanoparticles in aqueous solution is detailed here for the production of PbS and Cu-doped PbS nanoparticles. Subsequently, nanoparticles are annealed in a reducing atmosphere to remove surface oxide, and consolidated into dense polycrystalline materials by means of spark plasma sintering. By characterizing the transport properties of the sintered material, we observe the annealing step and the incorporation of Cu to play a key role in promoting the thermoelectric performance of PbS. The presence of Cu allows improving the electrical conductivity by increasing the charge carrier concentration and simultaneously maintaining a large charge carrier mobility, which overall translates into record power factors at ambient temperature, 2.3 mWm-1K−2. Simultaneously, the lattice thermal conductivity decreases with the introduction of Cu, leading to a record high ZT = 0.37 at room temperature and ZT = 1.22 at 773 K. Besides, a record average ZTave = 0.76 is demonstrated in the temperature range 320–773 K for n-type Pb0.955Cu0.045S.}, author = {Li, Mengyao and Liu, Yu and Zhang, Yu and Chang, Cheng and Zhang, Ting and Yang, Dawei and Xiao, Ke and Arbiol, Jordi and Ibáñez, Maria and Cabot, Andreu}, issn = {1385-8947}, journal = {Chemical Engineering Journal}, publisher = {Elsevier}, title = {{Room temperature aqueous-based synthesis of copper-doped lead sulfide nanoparticles for thermoelectric application}}, doi = {10.1016/j.cej.2021.133837}, volume = {433}, year = {2022}, } @article{10583, abstract = {The synthetic strigolactone (SL) analog, rac-GR24, has been instrumental in studying the role of SLs as well as karrikins because it activates the receptors DWARF14 (D14) and KARRIKIN INSENSITIVE 2 (KAI2) of their signaling pathways, respectively. Treatment with rac-GR24 modifies the root architecture at different levels, such as decreasing the lateral root density (LRD), while promoting root hair elongation or flavonol accumulation. Previously, we have shown that the flavonol biosynthesis is transcriptionally activated in the root by rac-GR24 treatment, but, thus far, the molecular players involved in that response have remained unknown. To get an in-depth insight into the changes that occur after the compound is perceived by the roots, we compared the root transcriptomes of the wild type and the more axillary growth2 (max2) mutant, affected in both SL and karrikin signaling pathways, with and without rac-GR24 treatment. Quantitative reverse transcription (qRT)-PCR, reporter line analysis and mutant phenotyping indicated that the flavonol response and the root hair elongation are controlled by the ELONGATED HYPOCOTYL 5 (HY5) and MYB12 transcription factors, but HY5, in contrast to MYB12, affects the LRD as well. Furthermore, we identified the transcription factors TARGET OF MONOPTEROS 5 (TMO5) and TMO5 LIKE1 as negative and the Mediator complex as positive regulators of the rac-GR24 effect on LRD. Altogether, hereby, we get closer toward understanding the molecular mechanisms that underlay the rac-GR24 responses in the root.}, author = {Struk, Sylwia and Braem, Lukas and Matthys, Cedrick and Walton, Alan and Vangheluwe, Nick and Van Praet, Stan and Jiang, Lingxiang and Baster, Pawel and De Cuyper, Carolien and Boyer, Francois-Didier and Stes, Elisabeth and Beeckman, Tom and Friml, Jiří and Gevaert, Kris and Goormachtig, Sofie}, issn = {1471-9053}, journal = {Plant & Cell Physiology}, keywords = {flavonols, MAX2, rac-Gr24, RNA-seq, root development, transcriptional regulation}, number = {1}, pages = {104--119}, publisher = {Oxford University Press}, title = {{Transcriptional analysis in the Arabidopsis roots reveals new regulators that link rac-GR24 treatment with changes in flavonol accumulation, root hair elongation and lateral root density}}, doi = {10.1093/pcp/pcab149}, volume = {63}, year = {2022}, } @article{10584, abstract = {Electrically tunable lenses (ETLs) are those with the ability to alter their optical power in response to an electric signal. This feature allows such systems to not only image the areas of interest but also obtain spatial depth perception (depth of field, DOF). The aim of the present study was to develop an ETL-based imaging system for quantitative surface analysis. Firstly, the system was calibrated to achieve high depth resolution, warranting the accurate measurement of the depth and to account for and correct any influences from external factors on the ETL. This was completed using the Tenengrad operator which effectively identified the plane of best focus as demonstrated by the linear relationship between the control current applied to the ETL and the height at which the optical system focuses. The system was then employed to measure amplitude, spatial, hybrid, and volume surface texture parameters of a model material (pharmaceutical dosage form) which were validated against the parameters obtained using a previously validated surface texture analysis technique, optical profilometry. There were no statistically significant differences between the surface texture parameters measured by the techniques, highlighting the potential application of ETL-based imaging systems as an easily adaptable and low-cost alternative surface texture analysis technique to conventional microscopy techniques}, author = {Nirwan, Jorabar Singh and Lou, Shan and Hussain, Saqib and Nauman, Muhammad and Hussain, Tariq and Conway, Barbara R. and Ghori, Muhammad Usman}, issn = {2072-666X}, journal = {Micromachines}, keywords = {surface texture, electrically tunable lens, materials, hypromellose, surface topography, surface roughness, pharmaceutical tablet, variable focus imaging}, number = {1}, publisher = {MDPI}, title = {{Electrically tunable lens (ETL) - based variable focus imaging system for parametric surface texture analysis of materials}}, doi = {10.3390/mi13010017}, volume = {13}, year = {2022}, } @article{10587, abstract = {Access to a blossoming library of colloidal nanomaterials provides building blocks for complex assembled materials. The journey to bring these prospects to fruition stands to benefit from the application of advanced processing methods. Epitaxially connected nanocrystal (or quantum dot) superlattices present a captivating model system for mesocrystals with intriguing emergent properties. The conventional processing approach to creating these materials involves assembling and attaching the constituent nanocrystals at the interface between two immiscible fluids. Processing small liquid volumes of the colloidal nanocrystal solution involves several complexities arising from the concurrent spreading, evaporation, assembly, and attachment. The ability of inkjet printers to deliver small (typically picoliter) liquid volumes with precise positioning is attractive to advance fundamental insights into the processing science, and thereby potentially enable new routes to incorporate the epitaxially connected superlattices into technology platforms. In this study, we identified the processing window of opportunity, including nanocrystal ink formulation and printing approach to enable delivery of colloidal nanocrystals from an inkjet nozzle onto the surface of a sessile droplet of the immiscible subphase. We demonstrate how inkjet printing can be scaled-down to enable the fabrication of epitaxially connected superlattices on patterned sub-millimeter droplets. We anticipate that insights from this work will spur on future advances to enable more mechanistic insights into the assembly processes and new avenues to create high-fidelity superlattices.}, author = {Balazs, Daniel and Erkan, N. Deniz and Quien, Michelle and Hanrath, Tobias}, issn = {1998-0000}, journal = {Nano Research}, keywords = {interfacial assembly, colloidal nanocrystal, superlattice, inkjet printing}, number = {5}, pages = {4536–4543}, publisher = {Springer Nature}, title = {{Inkjet printing of epitaxially connected nanocrystal superlattices}}, doi = {10.1007/s12274-021-4022-7}, volume = {15}, year = {2022}, } @article{10588, abstract = {We prove the Sobolev-to-Lipschitz property for metric measure spaces satisfying the quasi curvature-dimension condition recently introduced in Milman (Commun Pure Appl Math, to appear). We provide several applications to properties of the corresponding heat semigroup. In particular, under the additional assumption of infinitesimal Hilbertianity, we show the Varadhan short-time asymptotics for the heat semigroup with respect to the distance, and prove the irreducibility of the heat semigroup. These results apply in particular to large classes of (ideal) sub-Riemannian manifolds.}, author = {Dello Schiavo, Lorenzo and Suzuki, Kohei}, issn = {1432-1807}, journal = {Mathematische Annalen}, keywords = {quasi curvature-dimension condition, sub-riemannian geometry, Sobolev-to-Lipschitz property, Varadhan short-time asymptotics}, pages = {1815--1832}, publisher = {Springer Nature}, title = {{Sobolev-to-Lipschitz property on QCD- spaces and applications}}, doi = {10.1007/s00208-021-02331-2}, volume = {384}, year = {2022}, } @article{10589, abstract = {Superconducting devices ubiquitously have an excess of broken Cooper pairs, which can hamper their performance. It is widely believed that external radiation is responsible but a study now suggests there must be an additional, unknown source.}, author = {Higginbotham, Andrew P}, issn = {1745-2481}, journal = {Nature Physics}, keywords = {superconducting devices, superconducting properties and materials}, pages = {126}, publisher = {Springer Nature}, title = {{A secret source}}, doi = {10.1038/s41567-021-01459-x}, volume = {18}, year = {2022}, } @article{10600, abstract = {We show that recent results on adiabatic theory for interacting gapped many-body systems on finite lattices remain valid in the thermodynamic limit. More precisely, we prove a generalized super-adiabatic theorem for the automorphism group describing the infinite volume dynamics on the quasi-local algebra of observables. The key assumption is the existence of a sequence of gapped finite volume Hamiltonians, which generates the same infinite volume dynamics in the thermodynamic limit. Our adiabatic theorem also holds for certain perturbations of gapped ground states that close the spectral gap (so it is also an adiabatic theorem for resonances and, in this sense, “generalized”), and it provides an adiabatic approximation to all orders in the adiabatic parameter (a property often called “super-adiabatic”). In addition to the existing results for finite lattices, we also perform a resummation of the adiabatic expansion and allow for observables that are not strictly local. Finally, as an application, we prove the validity of linear and higher order response theory for our class of perturbations for infinite systems. While we consider the result and its proof as new and interesting in itself, we also lay the foundation for the proof of an adiabatic theorem for systems with a gap only in the bulk, which will be presented in a follow-up article.}, author = {Henheik, Sven Joscha and Teufel, Stefan}, issn = {1089-7658}, journal = {Journal of Mathematical Physics}, keywords = {mathematical physics, statistical and nonlinear physics}, number = {1}, publisher = {AIP Publishing}, title = {{Adiabatic theorem in the thermodynamic limit: Systems with a uniform gap}}, doi = {10.1063/5.0051632}, volume = {63}, year = {2022}, } @article{10602, abstract = {Transforming ω-automata into parity automata is traditionally done using appearance records. We present an efficient variant of this idea, tailored to Rabin automata, and several optimizations applicable to all appearance records. We compare the methods experimentally and show that our method produces significantly smaller automata than previous approaches.}, author = {Kretinsky, Jan and Meggendorfer, Tobias and Waldmann, Clara and Weininger, Maximilian}, issn = {1432-0525}, journal = {Acta Informatica}, keywords = {computer networks and communications, information systems, software}, pages = {585--618}, publisher = {Springer Nature}, title = {{Index appearance record with preorders}}, doi = {10.1007/s00236-021-00412-y}, volume = {59}, year = {2022}, } @article{10604, abstract = {Maternally inherited Wolbachia transinfections are being introduced into natural mosquito populations to reduce the transmission of dengue, Zika, and other arboviruses. Wolbachia-induced cytoplasmic incompatibility provides a frequency-dependent reproductive advantage to infected females that can spread transinfections within and among populations. However, because transinfections generally reduce host fitness, they tend to spread within populations only after their frequency exceeds a critical threshold. This produces bistability with stable equilibrium frequencies at both 0 and 1, analogous to the bistability produced by underdominance between alleles or karyotypes and by population dynamics under Allee effects. Here, we analyze how stochastic frequency variation produced by finite population size can facilitate the local spread of variants with bistable dynamics into areas where invasion is unexpected from deterministic models. Our exemplar is the establishment of wMel Wolbachia in the Aedes aegypti population of Pyramid Estates (PE), a small community in far north Queensland, Australia. In 2011, wMel was stably introduced into Gordonvale, separated from PE by barriers to A. aegypti dispersal. After nearly 6 years during which wMel was observed only at low frequencies in PE, corresponding to an apparent equilibrium between immigration and selection, wMel rose to fixation by 2018. Using analytic approximations and statistical analyses, we demonstrate that the observed fixation of wMel at PE is consistent with both stochastic transition past an unstable threshold frequency and deterministic transformation produced by steady immigration at a rate just above the threshold required for deterministic invasion. The indeterminacy results from a delicate balance of parameters needed to produce the delayed transition observed. Our analyses suggest that once Wolbachia transinfections are established locally through systematic introductions, stochastic “threshold crossing” is likely to only minimally enhance spatial spread, providing a local ratchet that slightly—but systematically—aids area-wide transformation of disease-vector populations in heterogeneous landscapes.}, author = {Turelli, Michael and Barton, Nicholas H}, issn = {2056-3744}, journal = {Evolution Letters}, keywords = {genetics, ecology, evolution, behavior and systematics}, number = {1}, pages = {92--105}, publisher = {Wiley}, title = {{Why did the Wolbachia transinfection cross the road? Drift, deterministic dynamics, and disease control}}, doi = {10.1002/evl3.270}, volume = {6}, year = {2022}, }