Now showing items 5739-5758 of 11675

    • J. R. R. Tolkien and the 1954 nomination of E. M. Forster for the Nobel Prize in Literature

      Wise, Dennis Wilson; Univ Arizona (MYTHOPOEIC SOCIETY, 2017)
      According to Dimitra Fimi, although some of Tolkien's romanticism remained "in the new idea of a 'proto-prehistoric' united Europe fighting against Sauron," such as we see in The Lord of the Rings, that kind of romanticism differs greatly from "the aggressive nationalism of The Book of Lost Tales" (130). Because of Fielding's perfect (and unusual) freedom to follow his conscience, he is liberal humanism's perfect representative. [...] despite clear intellectual differences, Tolkien's nomination of Forster may have rested on the sense of understanding he felt toward Forsterian morality as articulated in the novels. [...] the announcement for the creation of the Chair for Medieval and Renaissance English came in the same month as Nobel nominations were due.
    • J1342+0928 supports the timeline in the = cosmology

      Melia, Fulvio; Univ Arizona, Dept Phys, Appl Math Program; Univ Arizona, Dept Astron (EDP SCIENCES S A, 2018-07-24)
      Aims. The discovery of quasar J1342+0928 (z = 7.54) reinforces the time compression problem associated with the premature formation of structure in A cold dark matter (ACDM). Adopting the Planck parameters, we see this quasar barely 690 Myr after the big bang, no more than several hundred Myr after the transition from Pop III to Pop II star formation. Yet conventional astrophysics would tell us that a 10 M-circle dot seed, created by a Pop II/III supernova, should have taken at least 820 Myr to grow via Eddington-limited accretion. This failure by ACDM constitutes one of its most serious challenges, requiring exotic "fixes", such as anomalously high accretion rates, or the creation of enormously massive (similar to 10(5) M-circle dot) seeds, neither of which is ever seen in the local Universe, or anywhere else for that matter. Indeed, to emphasize this point, J1342+0928 is seen to be accreting at about the Eddington rate, negating any attempt at explaining its unusually high mass due to such exotic means. In this paper, we aim to demonstrate that the discovery of this quasar instead strongly confirms the cosmological timeline predicted by the R-h = Ct Universe. Methods. We assume conventional Eddington-limited accretion and the time versus redshift relation in this model to calculate when a seed needed to start growing as a function of its mass in order to reach the observed mass of J1342+0928 at z = 7.54. Results. Contrary to the tension created in the standard model by the appearance of this massive quasar so early in its history, we find that in the R-h = Ct cosmology, a 10 M-circle dot seed at z similar to 15 (the start of the Epoch of Reionization at t similar to 878 Myr) would have easily grown into an 8 x 10(8) M-circle dot black hole at z = 7.54 (t similar to 1.65 Gyr) via conventional Eddington-limited accretion.
    • J1342+0928 supports the timeline in the R-h = ct cosmology

      Melia, Fulvio; Univ Arizona, Dept Phys, Appl Math Program; Univ Arizona, Dept Astron (EDP SCIENCES S A, 2018-07-24)
      Aims. The discovery of quasar J1342+0928 (z = 7.54) reinforces the time compression problem associated with the premature formation of structure in A cold dark matter (ACDM). Adopting the Planck parameters, we see this quasar barely 690 Myr after the big bang, no more than several hundred Myr after the transition from Pop III to Pop II star formation. Yet conventional astrophysics would tell us that a 10 M-circle dot seed, created by a Pop II/III supernova, should have taken at least 820 Myr to grow via Eddington-limited accretion. This failure by ACDM constitutes one of its most serious challenges, requiring exotic "fixes", such as anomalously high accretion rates, or the creation of enormously massive (similar to 10(5) M-circle dot) seeds, neither of which is ever seen in the local Universe, or anywhere else for that matter. Indeed, to emphasize this point, J1342+0928 is seen to be accreting at about the Eddington rate, negating any attempt at explaining its unusually high mass due to such exotic means. In this paper, we aim to demonstrate that the discovery of this quasar instead strongly confirms the cosmological timeline predicted by the R-h = Ct Universe. Methods. We assume conventional Eddington-limited accretion and the time versus redshift relation in this model to calculate when a seed needed to start growing as a function of its mass in order to reach the observed mass of J1342+0928 at z = 7.54. Results. Contrary to the tension created in the standard model by the appearance of this massive quasar so early in its history, we find that in the R-h = Ct cosmology, a 10 M-circle dot seed at z similar to 15 (the start of the Epoch of Reionization at t similar to 878 Myr) would have easily grown into an 8 x 10(8) M-circle dot black hole at z = 7.54 (t similar to 1.65 Gyr) via conventional Eddington-limited accretion.
    • The Jazziness of Local Food Practice Work: Organization-Level Ingenuity and the Entrepreneurial Formation and Evolution of Local Food Systems

      Mars, Matthew M.; Schau, Hope Jensen; Univ Arizona, Dept Agr Leadership & Innovat; Univ Arizona, Dept Mkt (WILEY, 2019-06)
      Local food systems (LFSs) are complex and diverse social structures. The processes that influence the formation and evolution of LFSs are obscure, relatively uncoordinated, and somewhat mysterious. This study develops a stronger understanding of such processes through a qualitative exploration of the influence of routine practice work at the organization level on the entrepreneurial development of two distinct LFSs in the Southwest region of the United States: southeastern Arizona and Albuquerque-Santa Fe. We gathered data between August 2014 and September 2017 through semistructured interviews with and direct observations of 53 local food practitioners operating in one of the two LFSs. Theoretical principles of institutional entrepreneurship, embedded agency, and practice work guided the study. The findings reveal three forms of ingenuity (technological, organizational, policy) that regularly emerge through the day-to-day organization-level work of local food practitioners. We argue that the system-level influence of these forms, whether intentional or not, are indicators of the embedded agency of the practitioners and their capacities to serve as institutional entrepreneurs. We discuss implications for both practice and future research.
    • Jens Walther’s Abstieg vom Zauberberg (1997): A Literary Reflection on the World of Publishing in the Postmodern World

      Classen, Albrecht; Univ Arizona, Dept German Studies (SPRINGER, 2020-03)
      The world of book publishing is currently undergoing a major paradigm shift, but this was already fully under way in the 1990s. In the German novel Abstieg vom Zauberberg, published in 1997 by an anonymous author under the pseudonym Jens Walther, we are given an excellent insider view of the concrete situation within literary publishing houses and how they operate behind the scene and in public to secure the best possible titles and to fend off manuscripts that appear to be trivial literature. The author proves to be highly educated in the history of German and western literature at large and also demonstrates great expertise regarding book fairs, book reviews, and book prizes, framing all this by a somewhat twisted love story involving a young author, Anna Becker, and two men, first the young Johannes Rieger, then his father Helmut Rieger, both representing the fictional publishing house Engsfeld.
    • Jet and missing transverse momentum reconstruction in ATLAS at the LHC

      Loch, Peter; Department of Physics, University of Arizona (Sissa Medialab Srl, 2020-10-24)
      Particle jets and the missing transverse momentum (ETmiss) generated by the proton–proton collisions at the Large Hadron Collider (LHC) at CERN are important components of the final state reconstruction with the ATLAS detector. Both jet and ETmiss reconstruction during LHC Run 2 (2015–2018), where the protons were collided with a centre-of-mass energy of √s = 13 TeV, faced significant challenges due to the high beam intensities that introduced the highest level of pile-up so far. Selected results from the evaluation of the jet and ETmiss reconstruction performances are presented. Notably, the achieved precision of the jet energy measurement is about 1% over a large fraction of the accessible phase space for both narrow and wide jets, thus preserving the precision reached in previous LHC operations with significantly lower pile-up.
    • Jet energy scale and resolution measured in proton–proton collisions at √s=13 TeV with the ATLAS detector

      ATLAS Collaboration; Department of Physics, University of Arizona (Springer Science and Business Media Deutschland GmbH, 2021)
      Jet energy scale and resolution measurements with their associated uncertainties are reported for jets using 36–81 fb- 1 of proton–proton collision data with a centre-of-mass energy of s=13 TeV collected by the ATLAS detector at the LHC. Jets are reconstructed using two different input types: topo-clusters formed from energy deposits in calorimeter cells, as well as an algorithmic combination of charged-particle tracks with those topo-clusters, referred to as the ATLAS particle-flow reconstruction method. The anti-kt jet algorithm with radius parameter R= 0.4 is the primary jet definition used for both jet types. This result presents new jet energy scale and resolution measurements in the high pile-up conditions of late LHC Run 2 as well as a full calibration of particle-flow jets in ATLAS. Jets are initially calibrated using a sequence of simulation-based corrections. Next, several in situ techniques are employed to correct for differences between data and simulation and to measure the resolution of jets. The systematic uncertainties in the jet energy scale for central jets (| η| < 1.2) vary from 1% for a wide range of high-pT jets (250<pT<2000GeV), to 5% at very low pT (20GeV) and 3.5% at very high pT (>2.5TeV). The relative jet energy resolution is measured and ranges from (24 ± 1.5)% at 20 GeV to (6 ± 0.5)% at 300 GeV. © 2021, The Author(s).
    • JINGLE – IV. Dust, H i gas, and metal scaling laws in the local Universe

      De Looze, I; Lamperti, I; Saintonge, A; Relaño, M; Smith, M W L; Clark, C J R; Wilson, C D; Decleir, M; Jones, A P; Kennicutt, R C; et al. (OXFORD UNIV PRESS, 2020-06-02)
      Scaling laws of dust, HI gas, and metal mass with stellar mass, specific star formation rate, and metallicity are crucial to our understanding of the build-up of galaxies through their enrichment with metals and dust. In this work, we analyse how the dust and metal content varies with specific gas mass (M-HI/M-star) across a diverse sample of 423 nearby galaxies. The observed trends are interpreted with a set of Dust and Element evolUtion modelS (DEUS) - including stellar dust production, grain growth, and dust destruction - within a Bayesian framework to enable a rigorous search of the multidimensional parameter space. We find that these scaling laws for galaxies with -1.0 less than or similar to log M-HI/M-star less than or similar to 0 can be reproduced using closed-box models with high fractions (37-89 per cent) of supernova dust surviving a reverse shock, relatively low grain growth efficiencies (subset of = 30-40), and long dust lifetimes (1-2 Gyr). The models have present-day dust masses with similar contributions from stellar sources (50-80 per cent) and grain growth (20-50 per cent). Over the entire lifetime of these galaxies, the contribution from stardust (>90 per cent) outweighs the fraction of dust grown in the interstellar medium (<10 per cent). Our results provide an alternative for the chemical evolution models that require extremely low supernova dust production efficiencies and short grain growth time-scales to reproduce local scaling laws, and could help solving the conundrum on whether or not grains can grow efficiently in the interstellar medium.
    • JNK2 regulates vascular remodeling in pulmonary hypertension

      Das, Mita; Zawada, W. Michael; West, James; Stenmark, Kurt R.; Univ Arizona, Coll Med Phoenix, Dept Internal Med (SAGE PUBLICATIONS INC, 2018-07-03)
      Pulmonary arterial (PA) wall modifications are key pathological features of pulmonary hypertension (PH). Although such abnormalities correlate with heightened phosphorylation of c-Jun N-terminal kinases 1/2 (JNK1/2) in a rat model of PH, the contribution of specific JNK isoforms to the pathophysiology of PH is unknown. Hence, we hypothesized that activation of either one, or both JNK isoforms regulates PA remodeling in PH. We detected increased JNK1/2 phosphorylation in the thickened vessels of PH patients' lungs compared to that in lungs of healthy individuals. JNK1/2 phosphorylation paralleled a marked reduction in MAP kinase phosphatase 1 JNK dephosphorylator) expression in patients' lungs. Association of JNK1/2 activation with vascular modification was confirmed in the calf model of severe hypoxia-induced PH. To ascertain the role of each JNK isoform in pathophysiology of PH, wild-type (WT), JNK1 null (JKN1(-/-)), and JNK2 null (JNK2(-/)(-)) mice were exposed to chronic hypoxia (10% O-2 for six weeks) to develop PH. In hypoxic WT lungs, an increase in JNK1/2 phosphorylation was associated with PH-like pathology. Hallmarks of PH pathophysiology, i.e. excessive accumulation of extracellular matrix and vessel muscularization with medial wall thickening, was also detected in hypoxic JNK1(-/-) lungs, but not in hypoxia-exposed JNK2(-/-) lungs. However, hypoxia-induced increases in right ventricular systolic pressure (RVSP) and in right ventricular hypertrophy (RVH) were similar in all three genotypes. Our findings suggest that JNK2 participates in PA remodeling (but likely not in vasoconstriction) in murine hypoxic PH and that modulating JNK2 actions might quell vascular abnormalities and limit the course of PH.
    • Joint analysis of galaxy-galaxy lensing and galaxy clustering: Methodology and forecasts for Dark Energy Survey

      Park, Y.; Krause, E.; Dodelson, S.; Jain, B.; Amara, A.; Becker, M. R.; Bridle, S. L.; Clampitt, J.; Crocce, M.; Fosalba, P.; et al. (AMER PHYSICAL SOC, 2016-09-30)
      The joint analysis of galaxy-galaxy lensing and galaxy clustering is a promising method for inferring the growth function of large-scale structure. Anticipating a near future application of this analysis to Dark Energy Survey (DES) measurements of galaxy positions and shapes, we develop a practical approach to modeling the assumptions and systematic effects affecting the joint analysis of small-scale galaxy-galaxy lensing and large-scale galaxy clustering. Introducing parameters that characterize the halo occupation distribution (HOD), photometric redshift uncertainties, and shear measurement errors, we study how external priors on different subsets of these parameters affect our growth constraints. Degeneracies within the HOD model, as well as between the HOD and the growth function, are identified as the dominant source of complication, with other systematic effects being subdominant. The impact of HOD parameters and their degeneracies necessitate the detailed joint modeling of the galaxy sample that we employ. We conclude that DES data will provide powerful constraints on the evolution of structure growth in the Universe, conservatively/optimistically constraining the growth function to 7.9%/4.8% with its first-year data that cover over 1000 square degrees, and to 3.9%/2.3% with its full five-year data that will survey 5000 square degrees, including both statistical and systematic uncertainties.
    • A joint chance-constrained programming approach for the single-item capacitated lot-sizing problem with stochastic demand

      Gicquel, Céline; Cheng, Jianqiang; Univ Arizona, Dept Syst & Ind Engn (SPRINGER, 2018-05)
      We study the single-item single-resource capacitated lot-sizing problem with stochastic demand. We propose to formulate this stochastic optimization problem as a joint chance-constrained program in which the probability that an inventory shortage occurs during the planning horizon is limited to a maximum acceptable risk level. We investigate the development of a new approximate solution method which can be seen as an extension of the previously published sample approximation approach. The proposed method relies on a Monte Carlo sampling of the random variables representing the demand in all planning periods except the first one. Provided there is no dependence between the demand in the first period and the demand in the later periods, this partial sampling results in the formulation of a chance-constrained program featuring a series of joint chance constraints. Each of these constraints involves a single random variable and defines a feasible set for which a conservative convex approximation can be quite easily built. Contrary to the sample approximation approach, the partial sample approximation leads to the formulation of a deterministic mixed-integer linear problem having the same number of binary variables as the original stochastic problem. Our computational results show that the proposed method is more efficient at finding feasible solutions of the original stochastic problem than the sample approximation method and that these solutions are less costly than the ones provided by the Bonferroni conservative approximation. Moreover, the computation time is significantly shorter than the one needed for the sample approximation method.
    • Joint effects of citrus peel use and black tea intake on the risk of squamous cell carcinoma of the skin

      Hakim, Iman; Harris, Robin; University of Arizona College of Public Health and the Arizona Cancer Center, 1515 N Campbell Ave, Tucson, AZ 85724, USA (BioMed Central, 2001)
      BACKGROUND:Differences in tea drinking habits and/or citrus peel use are likely to vary by populations and could contribute to the inconsistencies found between studies comparing their consumption and cancer risk.METHODS:A population-based case-control study was used to evaluate the relationships between citrus peel use and black tea intake and squamous cell carcinoma (SCC) of the skin. Moreover, we assessed the independent and interactive effects of citrus peel and black tea in the development of SCC.RESULTS:Hot and iced teas were consumed by 30.7% and 51.8% of the subjects, respectively. Peel consumption was reported by 34.5% of subjects. Controls were more likely than were cases to report citrus peel use (odds ratio (OR) = 0.67) and hot tea intake (OR = 0.79). After adjustment for hot and iced tea intake, the ORs associated with citrus peel use were 0.55 and 0.69, respectively, whereas the corresponding adjusted ORs for hot and iced tea intake after adjustment for citrus peel use were 0.87 and 1.22 respectively. Compared with those who did not consume hot black tea or citrus peel, the adjusted ORs associated with sole consumption of hot black tea or citrus peel were 0.60 and 0.30, respectively. Subjects who reported consumption of both hot black tea and citrus peel had a significant marked decrease (OR= 0.22
    • Joint Probabilistic-Nyquist Pulse Shaping for an LDPC-Coded 8-PAM Signal in DWDM Data Center Communications

      Han, Xiao; Yang, Mingwei; Djordjevic, Ivan B; Yue, Yang; Wang, Qiang; Qu, Zhen; Anderson, Jon; Univ Arizona, ECE Dept (MDPI, 2019-11-20)
      M-ary pulse-amplitude modulation (PAM) meets the requirements of data center communication because of its simplicity, but coarse entropy granularity cannot meet the dynamic bandwidth demands, and there is a large capacity gap between uniform formats and the Shannon limit. The dense wavelength division multiplexing (DWDM) system is widely used to increase the channel capacity, but low spectral efficiency of the intensity modulation/direct detection (IM/DD) solution restricts the throughput of the modern DWDM data center networks. Probabilistic shaping distribution is a good candidate to offer us a fine entropy granularity and efficiently reduce the gap to the Shannon limit, and Nyquist pulse shaping is widely used to increase the spectral efficiency. We aim toward the joint usage of probabilistic shaping and Nyquist pulse shaping with low-density parity-check (LDPC) coding to improve the bit error rate (BER) performance of 8-PAM signal transmission. We optimized the code rate of the LDPC code and compared different Nyquist pulse shaping parameters using simulations and experiments. We achieved a 0.43 dB gain using Nyquist pulse shaping, and a 1.1 dB gain using probabilistic shaping, while the joint use of probabilistic shaping and Nyquist pulse shaping achieved a 1.27 dB gain, which offers an excellent improvement without upgrading the transceivers.
    • Joint QKD-Post-Quantum Cryptosystems

      Djordjevic, Ivan B.; Univ Arizona, Dept Elect & Comp Engn (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2020-08)
      To extend the transmission distance and/or improve secret-key rate of QKD protocols, we propose to employ the joint QKD-post-quantum cryptosystems in which QKD is used for raw-key transmission while the post-quantum cryptography (PQC) subsystem to transmit parity bits for information reconciliation. We also describe a run-time configurable spatially coupled (SC)-LDPC code, derived from template quasi cyclic (QC)-LDPC, suitable for use in both information reconciliation and McEliece crypto-subsystem. For twin-field (TF)-QKD subsystem, the proposed joint cryptosystem, which takes the complexity of algorithm used to break the PQC subsystem into account, is able to achieve record distance of 1238 km over ultra-low-loss fiber.
    • Joint Strong and Weak Lensing Analysis of the Massive Cluster Field J0850+3604

      Wong, Kenneth C.; Raney, Catie; Keeton, Charles R.; Umetsu, K.; Zabludoff, Ann; Ammons, S. Mark; French, K. Decker; Univ Arizona, Steward Observ (IOP PUBLISHING LTD, 2017-07-31)
      We present a combined strong and weak lensing analysis of the J085007.6+360428 (J0850) field, which contains the massive cluster Zwicky 1953. This field was selected for its high projected concentration of luminous red galaxies. Using Subaru/Suprime-Cam BVR(c)I(c)i'z' imaging and MMT/Hectospec spectroscopy, we first perform a weak lensing shear analysis to constrain the mass distribution in this field, including the cluster at z = 0.3774 and a smaller foreground halo at z = 0.2713. We then add a strong lensing constraint from a multiply imaged galaxy in the imaging data with a photometric redshift of z approximate to 5.03. Unlike previous cluster-scale lens analyses, our technique accounts for the full three-dimensional mass structure in the beam, including galaxies along the line of sight. In contrast with past cluster analyses that used only lensed image positions as constraints, we use the full surface brightness distribution of the images. This method predicts that the source galaxy crosses a lensing caustic, such that one image is a highly magnified "fold arc" that could be used to probe the source galaxy's structure at ultra-high spatial resolution (< 30 pc). We calculate the mass of the primary cluster to be M-vir = 2.93(-0.65)(+0.71) x 10(15) M-circle dot. with a concentration of C-vir = 3.46(-0.59)(+0.70), consistent with the mass-concentration relation of massive clusters at a similar redshift. The large mass of this cluster makes J0850 an excellent field for leveraging lensing magnification to search for high-redshift galaxies, competitive with and complementary to that of well-studied clusters such as the HST Frontier Fields.
    • A joint SZ–X-ray–optical analysis of the dynamical state of 288 massive galaxy clusters

      Zenteno, A; Hernández-Lang, D; Klein, M; Vergara Cervantes, C; Hollowood, D L; Bhargava, S; Palmese, A; Strazzullo, V; Romer, A K; Mohr, J J; et al. (OXFORD UNIV PRESS, 2020-05-04)
      We use imaging from the first three years of the Dark Energy Survey to characterize the dynamical state of 288 galaxy clusters at 0.1 less than or similar to z less than or similar to 0.9 detected in the South Pole Telescope (SPT) Sunyaev-Zeldovich (SZ) effect survey (SPT-SZ). We examine spatial offsets between the position of the brightest cluster galaxy (BCG) and the centre of the gas distribution as traced by the SPT-SZ centroid and by the X-ray centroid/peak position from Chandra and XMM data. We show that the radial distribution of offsets provides no evidence that SPT SZ-selected cluster samples include a higher fraction of mergers than X-ray-selected cluster samples. We use the offsets to classify the dynamical state of the clusters, selecting the 43 most disturbed clusters, with half of those at z greater than or similar to 0.5, a region seldom explored previously. We find that Schechter function fits to the galaxy population in disturbed clusters and relaxed clusters differ at z > 0.55 but not at lower redshifts. Disturbed clusters at z > 0.55 have steeper faint-end slopes and brighter characteristic magnitudes. Within the same redshift range, we find that the BCGs in relaxed clusters tend to be brighter than the BCGs in disturbed samples, while in agreement in the lower redshift bin. Possible explanations includes a higher merger rate, and a more efficient dynamical friction at high redshift. The red-sequence population is less affected by the cluster dynamical state than the general galaxy population.
    • Jordan’s Accession to the WTO: Retrospective and Prospective

      Malkawi, Bashar; Univ Arizona, James E Rogers Coll Law (The Estey Centre, 2010)
      Jordan acceded to the WTO in 1999. In its accession Jordan agreed, for example, to reduce tariffs on imported products and open its services market; it also modified its intellectual property regime. Jordan enjoyed special and differential treatment in few areas and was not able to designate olive oil as a good eligible for special safeguards. The WTO agreements required fundamental changes in the domestic laws and regulations of Jordan. The article concludes by arguing that Jordan’s accession to the WTO was a lengthy and costly process. Jordan agreed to an arduous package of legal and economic reforms. Given that Jordan agreed to greater commitments compared to the obligations of the original WTO members, the multilateral trading system witnessed an accession saga.
    • Joseph Petzval lens design approach

      Sasián, José; Univ Arizona, Coll Opt Sci (SPIE-INT SOC OPTICAL ENGINEERING, 2017-11-27)
      We pose that there is enough information left to reconstruct Petzval lens design approach, and answer the question of how Joseph Petzval design his famous portrait objective.
    • The Journey Home: Violence, Anchoring, and Refugee Decisions to Return

      Ghosn, Faten; Chu, Tiffany S.; Simon, Miranda; Braithwaite, Alex; Frith, Michael; Jandali, Joanna; School of Government and Public Policy, University of Arizona (Cambridge University Press (CUP), 2021-05-17)
      While the UNHCR promotes voluntary repatriation as the preferred solution to refugee situations, there is little understanding of variation in refugees' preferences regarding return. We develop a theoretical framework suggesting two mechanisms influencing refugees' preferences. First, refugees' lived experiences in their country of origin prior to displacement and in their new host country create a trade-off in feelings of being anchored to their origin or host country. Second, firsthand exposure to traumas of war provides some refugees with a sense of competency and self-efficacy, leading them to prefer to return home. We test these relationships with data from a survey among Syrian refugees hosted in Lebanon. We find refugees exposed to violence during the war have a sense of attachment to Syria and are most likely to prefer return. Refugees who have developed a detachment from Syria or an attachment to Lebanon are less likely to prefer return.
    • A journey of exploration to the polar regions of a star: probing the solar poles and the heliosphere from high helio-latitude

      Harra, Louise; Andretta, Vincenzo; Appourchaux, Thierry; Baudin, Frédéric; Bellot-Rubio, Luis; Birch, Aaron C.; Boumier, Patrick; Cameron, Robert H.; Carlsson, Matts; Corbard, Thierry; et al. (Springer Science and Business Media LLC, 2021-07-31)
      A mission to view the solar poles from high helio-latitudes (above 60°) will build on the experience of Solar Orbiter as well as a long heritage of successful solar missions and instrumentation (e.g. SOHO Domingo et al. (Solar Phys. 162(1-2), 1–37 1995), STEREO Howard et al. (Space Sci. Rev. 136(1-4), 67–115 2008), Hinode Kosugi et al. (Solar Phys. 243(1), 3–17 2007), Pesnell et al. Solar Phys. 275(1–2), 3–15 2012), but will focus for the first time on the solar poles, enabling scientific investigations that cannot be done by any other mission. One of the major mysteries of the Sun is the solar cycle. The activity cycle of the Sun drives the structure and behaviour of the heliosphere and of course, the driver of space weather. In addition, solar activity and variability provides fluctuating input into the Earth climate models, and these same physical processes are applicable to stellar systems hosting exoplanets. One of the main obstructions to understanding the solar cycle, and hence all solar activity, is our current lack of understanding of the polar regions. In this White Paper, submitted to the European Space Agency in response to the Voyage 2050 call, we describe a mission concept that aims to address this fundamental issue. In parallel, we recognise that viewing the Sun from above the polar regions enables further scientific advantages, beyond those related to the solar cycle, such as unique and powerful studies of coronal mass ejection processes, from a global perspective, and studies of coronal structure and activity in polar regions. Not only will these provide important scientific advances for fundamental stellar physics research, they will feed into our understanding of impacts on the Earth and other planets’ space environment. © 2021, The Author(s).