Classical Mode Research Articles

Diets of erythritol, xylitol, and sucrose affect the digestive activity and gut bacterial community in adult house flies

AbstractPolyol sweeteners, including erythritol and xylitol, have been investigated for their potential in insect control against a number of pests including mosquitoes, fruit flies, ants, and filth flies. Several insecticidal modes of action for the polyols have been proposed in non‐biting flies and include: (1) dehydration from excessive regurgitation, (2) arrestment of physiological processes due to abnormally high hemolymph osmolality or osmotic diarrhea, and (3) alteration of the gut microbiome. Here, we explored the proposed modes of action in the house fly, Musca domestica L. (Diptera: Muscidae), a non‐biting fly of medical and veterinary importance. House flies fed erythritol or xylitol regurgitated at a significantly higher rate when compared to flies that ingested sucrose. Flies that ingested sucrose solutions had higher hemolymph osmolality than erythritol but not xylitol, and deposited significantly more fecal spots than flies fed polyol solutions. Cultivable bacteria were least abundant in flies fed solutions of either sucrose or xylitol and most abundant in control flies provided water only. Of the potential modes of action tested, physiological stress from excessive post‐feeding regurgitation seems the likeliest cause of death related to polyol consumption. However, we cannot rule out a classical toxicological or biochemical mode of action from these results. Although the efficacy of polyols as active ingredients is still under debate, their use as other components in fly control products may be beneficial. Due to widespread resistance to a limited number of insecticidal chemicals registered for house fly control, it is important that new control chemicals be thoroughly assessed for usefulness.

المعتقدات السودانية في الشعر السوداني

In any community, beliefs are formed according to ideological, historical, political, intellectual, social and environmental changes. Hence, the research aims at unmasking the role of these changes in forming beliefs in the Sudan and, thereof, showing the way they are reflected in Sudanese poetry. Accordingly, the problem of the research consists inherently in the following question: to what extent could the Sudanese poets highlight Suda- nese beliefs in their own poetry? In this context, a group of Sudanese poets have highlighted the images of those Sudanese beliefs which are distinguished from the beliefs of other countries. In this regard, the Sudanese poets are obviously strongly affected by the call of the late Sudanese critic, Hamza al-Malik Ṭambal (in early twentieth century), in which he called on the Sudanese poets to emancipate themselves from imitating the classic mode of old and contemporary Arab poetry. To Ṭambal, this style of the classic Arab verse has negatively impacted the Sudanese poem, the result of which is the lack of the distinctive character of the Sudanese poetry. Of the most important outcomes concluded by the researcher is that the Sudanese poets, in their portrayal of the Sudanese beliefs in their poetries, have been flagrantly been affected by the call of the Sudanese critic, Ṭambal. Therefore, the Sufi idiosyncrasy has predominantly prevailed over these images as a result of the overriding Sufi current over the Sudanese community. Likewise, before penetration of Islam into the Sudan, the indigenous Sudanese beliefs had had a clear role in forming those images, notwithstanding the incompatibility of the images to the Islamic faith. Moreover, the Sudanese social variation had its own obvious role in forming the images of those beliefs, particularly predilection for rapture and music rhythm. Also, of the ensuing outcomes, those icons came to be as closely resembling folkloric pictures

Toughening induced by the formation of facets in mode I+III brittle fracture: Experiments versus a two-scale Cohesive Zone model

When subjected to some anti-plane shear mode III loading, segmentation of the crack front frequently occurs during propagation: even if the crack is initially planar, propagation produces facets/segments rotated toward the shear free direction. Here, we examine, both experimentally and theoretically, the effect of this microstructure on the effective macroscale brittle fracture toughness. Experiments performed on PMMA beams reveal that the critical load leading to abrupt rupture increases with mode III to mode I ratio. This apparent macroscopic toughening is usually taken into account by invoking a specific mode III toughness in addition to the mode I one. By applying thoroughfully a micro/macroscale Cohesive Zone (CZ) model that we have recently developed, we demonstrate that an additional material constant is useless here since this toughness increase can be attributed mainly to the presence of the facets at the microscale, whose geometry can be anticipated to depend on the classical mode I material constants. More precisely, two related physical mechanisms are generated due to the formation of a disconnected crack front: (i) changes in fractured surface area in comparison to a straight propagation, and (ii) crack shielding caused by the facets that reduce the effective crack opening. While the first effect is obvious to quantify, we show that the second plays an essential role but is more complex to take into account: it depends on the solution of the three-dimensional elasticity problem in presence of the facets, that is considered in the CZ model. We illustrate on the experiments how to use this approach in practice to determine the critical fracture threshold.

A role for substance P and acid-sensing ion channel 1a in prolotherapy with dextrose-mediated analgesia in a mouse model of chronic muscle pain.

Prolotherapy is widely used in pain control and tissue repair in pain medicine. The classical mode is injection with hypertonic dextrose in muscle or perimysium. However, the analgesic mechanism is still not known. Here, we successfully established dextrose-mediated antinociception in a mouse model of fibromyalgia. The antinociceptive effects of dextrose injections were evaluated in a mouse model of fibromyalgia, in which bilateral chronic mechanical hyperalgesia was induced by unilateral intramuscular acid injection. The injectant (dextrose), dose (≥5%), and volume (>10 μL), but not osmolarity, were essential for the prolotherapy. Further studies showed that the activation of acid-sensing ion channel 1a (ASIC1a), neural activation, and the release of substance P from muscle afferents were required in the dextrose-induced reduction of mechanical hypersensitivity. Both pharmacological blockade and genetic deletion of ASIC1a or substance P as well as lidocaine abolished the dextrose-induced antinociception in mice with chronic hyperalgesia. Moreover, intramuscular dextrose injection induced phosphorylated extracellular signal-regulated kinase expression in dorsal root ganglion neurons expressing substance P; the phosphorylated extracellular signal-regulated kinase expression was inhibited by the ASIC1a antagonist PcTx1. The optimal settings for prolotherapy in fibromyalgia-like pain are dextrose dependent and volume dependent, and the peripheral antinociception involves ASIC1a and substance P signaling in muscle afferents. This study suggests a possible mechanism of action of dextrose prolotherapy in noninflammatory muscle pain such as fibromyalgia and provides insights into treating other types of chronic pain.

A novel dual-mode robust model predictive control approach via alternating optimizations

The minimal robust positively invariant (mRPI) set plays an important role in robust model predictive control (RMPC). However, the exact computation of the mRPI set is generally intractable. This paper proposes a novel ℋ∞-type RMPC approach for linear systems with additive disturbances. This approach enables users to compute an ellipsoidal RPI set that approximates the minimal one in online implementations. Considering that a bilinear matrix inequality is involved in the problem formulation, an alternating optimization method is proposed in this work to ensure that the optimization problem to be solved online is always convex. Furthermore, a novel dual-mode control strategy is introduced that consists of two modes, i.e., with, and without alternating optimizations. The “classic mode” achieves fast convergence of the control algorithm, while the “alternating mode” can precisely approximate the mRPI set. None of the proposed approaches requires any off-line design, which makes practical applications more convenient. Simulations are conducted to demonstrate the effectiveness of the proposed approaches.

A Porous Coordination Polymer Showing Guest-Amplified Positive and Negative Thermal Expansion.

A solvothermal reaction of Zn(NO3)2 and 4-(1H-pyrazol-4-yl)benzoic acid (H2pba) with toluene (Tol) as the template yielded a porous coordination polymer, [Zn(pba)]·0.5Tol, possessing a three-dimensional (3D) fence-like coordination framework based on inclined two-dimensional (2D) fence-like coordination layers. By virtue of the classic deformation mode of the 2D/3D fence structures, the guest-free structure exhibits very large positive thermal expansion of 347 MK-1 and moderate negative thermal expansion of -63/-83 MK-1, which are remarkably enhanced to new records of 689 and -171/-249 MK-1, respectively, by inclusion of Tol.

Including Substrate Losses and Noise in a Quantum Mechanical Model of a Josephson Traveling-Wave Parametric Amplifier

Substrate losses affect the performance of dispersive readout of superconducting qubits. We present a quantum mechanical model of a Josephson traveling-wave parametric amplifier, including substrate losses and the associated noise contributions. Losses and noise are introduced by coupling the system Hamiltonian to a bosonic bath, where the coupling constants can be related to the loss tangent of the transmission line substrate. Closed-form solutions for the temporal evolution of discrete mode operators in the presence of losses and noise are derived, under the assumption of a strong classical pump mode. A careful analysis of the loss-induced noise contributions can lead to the formulation of limits for the scaling of ultra-low noise qubit readout.

Effects in the Optical and Structural Properties Caused by Mg or Zn Doping of GaN Films Grown via Radio-Frequency Magnetron Sputtering Using Laboratory-Prepared Targets

GaN films doped with Mg or Zn were obtained via radio-frequency magnetron sputtering on silicon substrates at room temperature and used laboratory-prepared targets with Mg-doped or Zn-doped GaN powders. X-ray diffraction patterns showed broadening peaks, which could have been related to the appearance of nano-crystallites with an average of 7 nm. Scanning electron microscopy and transmission electron microscopy showed good adherence to silicon non-native substrate, as well as homogeneity, with a grain size average of 0.14 µm, and 0.16 µm for the GaN films doped with Zn or Mg, respectively. X-ray photo-electron spectroscopy demonstrated the presence of a very small amount of magnesium (2.10 mol%), and zinc (1.15 mol%) with binding energies of 1303.18, and 1024.76 eV, respectively. Photoluminescence spectrum for the Zn-doped GaN films had an emission range from 2.89 to 3.0 eV (429.23–413.50 nm), while Mg-doped GaN films had an energy emission in a blue-violet band with a range from 2.80 to 3.16 eV (443.03–392.56 nm). Raman spectra showed the classical vibration modes A1(TO), E1(TO), and E2(High) for the hexagonal structure of GaN.

Internationalizing small-sized cities through mega-events: the case of Matera-Basilicata 2019 European Capital of Culture

ABSTRACT The paper is part of an ongoing thesis on the city of Matera (Italy). The research questions the effects and challenges of a double international recognition on urban space production: the mega-event ‘European Capital of Culture’ and the UNESCO World Heritage status. Using Matera’s bid book to become the European Capital of Culture, the paper focuses on the vocabulary used by the experts in charge of the application and questions the city models underlying the cultural programme. Through the use of an entrepreneurial vocabulary, the stakeholders of the Matera–Basilicata 2019 Foundation propose to transform the classic modes of bureaucratic management and the way of conceiving urban design. In this perspective, the challenge is no longer to invest in infrastructural components or public facilities but to create a new attractive image of the city. In this context, the Foundation in charge of the organization of the event acts as a company to promote new narratives and to provide new services for the city. The label ‘European Capital of Culture’ is therefore used to promote the city through a new urban vision, which reinterprets the local and historical urban representations.

Tonic prime-boost of STING signalling mediates Niemann-Pick disease type C.

The classic mode of STING activation is through binding the cyclic dinucleotide 2'3'-cyclic GMP-AMP (cGAMP), produced by the DNA sensor cyclic GMP-AMP synthase (cGAS), which is important for the innate immune response to microbial infection and autoimmune disease. Modes of STING activation that are independent of cGAS are much less well understood. Here, through a spatiotemporally resolved proximity labelling screen followed by quantitative proteomics, we identify the lysosomal membrane protein Niemann-Pick type C1 (NPC1) as a cofactor in the trafficking of STING. NPC1 interacts with STING and recruits it to the lysosome for degradation in both human and mouse cells. Notably, we find that knockout of Npc1 'primes' STING signalling by physically linking or 'tethering' STING to SREBP2 trafficking. Loss of NPC1 protein also 'boosts' STING signalling by blocking lysosomal degradation. Both priming and boosting of STING signalling are required for severe neurological disease in the Npc1-/- mouse. Genetic deletion of Sting1 (the gene that encodes STING) or Irf3, but not that of Cgas, significantly reduced the activation of microglia and relieved the loss of Purkinje neurons in the cerebellum of Npc1-/- mice, leading to improved motor function. Our study identifies a cGAS- and cGAMP-independent mode of STING activation that affects neuropathology and provides a therapeutic target for the treatment of Niemann-Pick disease typeC.

The predicted rate-dependent deformation behaviour and multistage strain hardening in a model heterostructured body-centered cubic high entropy alloy

Heterostructured high-entropy alloys (HEAs) exhibit a good combination of strength and ductility. However, the deformation mechanisms and related mechanical properties of the heterogeneous nanostructured body-centred cubic (BCC) HEAs remain largely unrevealed. Here, we report the effect of the strain rate on the mechanical properties and microstructural evolution in the heterostructured Al3CoCrCuFeNi HEA with the gradient grain size ranging from 9 nm at the surface to 45 nm in the center using the large-scale atomic simulations. Based on the characterization of microstructure evolution from the atomic simulation, a microstructure-based constitutive model that utilizes a single parameter set is established to study the effects of the multiple strengthening mechanisms at various deformation stages on the strength and strain hardening of the heterostructured HEA under different strain rates. The results show that the plastic deformation mechanisms are strongly influenced by the strain rate in the range of 1 × 106 to 1 × 1010 s−1. The dislocation and deformation twin are the main deformation mechanisms at the strain rate less than 1 × 108 s−1. The deformation twinning cooperated with multiple phase transformations plays a pivotal role at the strain rate of 1 × 109 s−1. The multiple phase transformations are the dominant plastic deformation model at the strain rate of 1 × 1010 s−1, which is different from the classic plastic-deformation mode, including the dislocation and deformation twin in traditional alloys. This phenomenon is ascribed to various types of atomic interactions and atomic-size mismatches, which produce strong lattice distortion. In particular, a large number of edge dislocations are observed, which is extremely different from screw dislocations invariably generated in traditional BCC alloys, and thus, could be responsible for high strength. Furthermore, the stress-strain response of the Al3CoCrCuFeNi HEA is derived from the individual contributions of the lattice distortion, dislocation, grain boundary, deformation twin, phase transformation, and back-stress strengthening mechanisms. The heterogeneous grain boundaries and lattice distortion contribute the most to the yield strength, and the dislocation, deformation twin, phase transformation, and back stress dominate the strain hardening. Therefore, these results highlight a new design strategy of HEAs to tailor their mechanical properties based on the partition of the multistage strengthening mechanisms by the heterostructure.

Real-time chatter detection via iterative Vold-Kalman filter and energy entropy

Real-time chatter detection is important in improving the surface quality of workpieces in milling. Since the process from stable cutting to chatter is characterized by the progressive variation of the vibration energy distribution, entropy has been utilized to capture the decreasing randomness of vibration signals when chatter occurs. To make such an index more sensitive to transitions of the cutting state, the entropy can be computed based on signal components obtained through signal decomposition techniques. However, the classic empirical mode decomposition (EMD) is difficult to put into practice due to its weak robustness to noises. The up-to-date variational mode decomposition (VMD) has strict requirements on a priori information about the signal and thus is not applicable either. In this paper, a novel method named the iterative Vold-Kalman filter (I-VKF) is proposed under the framework of the greedy algorithm, where the Vold-Kalman filter (VKF), a classic order tracker for rotating machinery, is improved to recursively extract each signal component. In the meantime, a spectrum concentration index–based technique is developed for the estimation of the instantaneous chatter frequency to adaptively determine the filter parameter. Numerical examples demonstrate the superiority of the I-VKF over the original VKF, EMD, and VMD, especially in the presence of strong noises. Combined with the energy entropy of extracted components and an automatically calculated threshold, the proposed strategy greatly helps in timely chatter detection, which has been verified by dynamic simulation and experiments.

Time and Temporality: M. Heidegger`s Interpretation versus H. Bergson’s Intuition

The issue of the postmodern conceptualization of temporality is realized in a number of different fields of science and scientific schools. At the same time the relationship between discourse of temporality as theory and discursive practices of temporal modes is widely represented both in "high" and popular culture. As a result, classical concepts and traditional notions have been abandoned with the consequent predominance of plurality of meanings and variability of senses, which opens theoretical space for examining time and temporality both in modernity and postmodernity. 
 The aim of theorizing temporality in this article is presented as conceptual reconstruction of temporality in Heidegger`s and Bergson`s ideas who, while working approximately at the same period, addressed temporality from different standpoints; however, both laid the foundation for the postmodern conceptual apparatus of researching temporality. The attempts of analyzing temporality also include their most influential approaches to the interaction of "interpretation" and "intuition" in the post-paradigmatic "drift" under the "postmodern conditions". The methods of the analysis are stipulated by the interdisciplinary character of the research, which demands complex approaches and systematic investigation with the bias on phenomenological, hermeneutic and post-structural methods. 
 The scientific novelty of the research lies in the reconstruction of the notion and models of temporality in Heidegger`s and Bergson`s conceptions with the accent on the "volumetrical" reflections of both scientists, which include the dialogue relations in their creating meanings and concept, the dialogism (M. Bakhtin) in painting the polyphonic picture of the world. At present, temporality is often used both as a flexible notion and a kind of epiphenomenon of time, occupying mid-positions between the absolute time and the relative time. Heidegger accentuates the notional character of time, however using the term "phenomenon" in some cases, as for "Bergsonism" duration is presented as a notion in its conceptual development (Deleuze). According to Heidegger, all philosophic propositions are temporal ones; still he obviously could not have introduced his "finite temporalization" without Bergson`s claim of the ontological priority of duration. Though in the postmodern theory it is accepted that the unprecedented stress on temporality is due to Heidegger, the recognition should go back to Bergson for having transformed the classical modes of time and temporality and traditional approaches to their conceptualization.

Mode superposition methods based on hysteretic damping assumption used in seismic calculation of hybrid structures

To make it mathematically easy to solve, various practical time history analysis methods are all based on the viscous damping assumption to establish the dynamic equations of the system. From the viscous damping assumption, the conclusion that the damping force or its energy dissipation of the system is proportional to the frequency of the system can be deduced, which is not consistent with the experimental results. When the classical mode superposition method based on the viscous damping assumption is used to calculate the dynamic response of a hybrid structure under an earthquake, how to calculate the modal damping ratio or how to determine a number of significant frequencies of the response to calculate the damping matrix has always been an urgent problem to be resolved in the engineering community. Since the hysteretic damping assumption is consistent with the experimental results, the mode superposition method based on the hysteretic damping assumption is explored in this paper to solve the above problems. The mode superposition method based on the hysteretic damping assumption can avoid the modal damping ratio trouble of the classical mode superposition method based on the viscous damping assumption, and its damping matrix has advantages of simple construction method and small construction workload and clear physical meaning. In this paper, the complex mode superposition method and the real mode superposition method based on the hysteretic damping assumption are studied, the calculation results and calculation efficiency of the two methods are analyzed and compared, and the conclusion is drawn that the real mode superposition method is better than the complex mode superposition method.

Dynamics of Development of Folklore Festivals in Volyn in the Late 20th Century. Features of Formation

The paper addresses the problems of Volyn festival movement. The aim of this study is to consider the specifics of Volyn folklore festivals “Berehynia” and “Polissia Summer With Folklore” as prominent international projects. The research included collecting information from various sources (books, magazine and newspaper articles, interviews with organizers and participants, observations), analytical processing of this information, description of important facts, comparison of festivals by project size, age and social status of the audience, festival goal and scope, frequency, as well as social, demographic, geographical, professional status of their participants, conceptual differences and features, place and nature of events, ways to present projects to the general public and others. As a result, it was concluded that “Berehynia” is a festival of a classical mode while “Polissia Summer With Folklore” is a festival of a non-classical mode.

Evaluation of the Performances of Radar and Lidar Altimetry Missions for Water Level Retrievals in Mountainous Environment: The Case of the Swiss Lakes

Radar altimetry is now commonly used to provide long-term monitoring of inland water levels in complement to or for replacing disappearing in situ networks of gauge stations. Recent improvements in tracking and acquisition modes improved the quality the water retrievals. The newly implemented Open Loop mode is likely to increase the number of monitored water bodies owing to the use of an a priori elevation, especially in hilly and mountainous areas. The novelty of this study is to provide a comprehensive evaluation of the performances of the past and current radar altimetry missions according to their acquisition (Low Resolution Mode or Synthetic Aperture Radar) and tracking (close or open loop) modes, and acquisition frequency (Ku or Ka) in a mountainous area where tracking losses of the signal are likely to occur, as well as of the recently launched ICESat-2 and GEDI lidar missions. To do so, we evaluate the quality of water level retrievals from most radar altimetry missions launched after 1995 over eight lakes in Switzerland, using the recently developed ALtimetry Time Series software, to compare the performances of the new tracking and acquisition modes and also the impact of the frequency used. The combination of the Open Loop tracking mode with the Synthetic Aperture Radar acquisition mode on SENTINEL-3A and B missions outperforms the classical Low Resolution Mode of the other missions with a lake observability greater than 95%, an almost constant bias of (−0.17 ± 0.04) m, a RMSE generally lower than 0.07 m and a R most of the times higher than 0.85 when compared to in situ gauge records. To increase the number of lakes that can be monitored and the temporal sampling of the water level retrievals, data acquired by lidar altimetry missions were also considered. Very accurate results were also obtained with ICESat-2 data with RMSE lower than 0.06 and R higher than 0.95 when compared to in situ water levels. An almost constant bias (0.42 ± 0.03) m was also observed. More contrasted results were obtained using GEDI. As these data were available on a shorter time period, more analyses are necessary to determine their potential for retrieving water levels.

Ultrafast Fluorescence Depolarization in Conjugated Polymers.

We report on large-scale simulations of intrachain exciton dynamics in poly(para-phenylenevinylene). Our theoretical model describes Frenkel exciton coupling to both fast, quantized C-C bond vibrations and slow, classical torsional modes. We also incorporate system-bath interactions. The dynamics is simulated using the time evolution block decimation method, which avoids the failures of the Ehrenfest approximation to describe decoherence processes and nonadiabatic interstate conversion. System-bath interactions are modeled using quantum trajectories and Lindblad quantum jump operators. We find that following photoexcitation, the quantum mechanical entanglement of the exciton and C-C bond phonons causes exciton-site decoherence. Next, system-bath interactions cause the stochastic collapse of high-energy delocalized excitons into chromophores. Finally, torsional relaxation causes additional exciton-density localization. We relate these dynamical processes to the predicted fluorescence depolarization, extract the time scales corresponding to them, and thus interpret the observed sub-ps fluorescence depolarization.

Band-pass filter-assisted ratiometric fluorescent nanoprobe composed of N-(2-aminoethyl-1,8-naphthalimide)-functionalized gold nanoclusters for the determination of alkaline phosphatase using digital image analysis.

A smartphone-based dual-wavelength digital imaging platform containing red (539-695nm) and blue (389-511nm) band-pass filters was developed for point-of-care (POC) testing of alkaline phosphatase (ALP) activity. The platform was based on dual-emitting fluorescent nanohybrids (AuNC@NAN), the ratiometric probe, which had a fluorescence "on-off-on-off" response. The probe comprised red-emitting gold nanoclusters (AuNCs) acting as the signal report units and blue-emitting N-(2-aminoethyl-1,8-naphthalimide) (NAN) acting as an internal reference. The different responses of the ratiometric probes resulted in a continuous color-multiplexing change from pink-red to dark-purple upon exposure to ALP. The dual-wavelength digital imaging platform was employed to acquire images of AuNC or NAN fluorescence signals without the influence of background light. Unlike the classical one-time digital imaging mode, the accurate red (R) and blue (B) channel values of the generated images can help to directly judge or eliminate the disturbance from unavoidable interfering factors. The R/B values were successfully employed for determining the ALP activity at a range 2.0 to 35.0mU·mL-1 with the detection limit of 1.04mU·mL-1. Such sensing imaging platform is also successful in determining ALP activity in human serum with 94.9-105% recoveries and relative standard deviation in the range 4.2-5.6%. A novel dual-wavelength smartphone-based digital imaging platform was proposed for simultaneous readout of the reporting and internal reference signals from dual-emitting ratiometric fluorescence probes, which allowed us to the accurate, reliable, and highly sensitive assay of ALP activity in complex samples.

A computationally efficient adaptive robust control scheme for a quad-rotor transporting cable-suspended payloads

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.

How many suns are in the sky? A SPHERE multiplicity survey of exoplanet host stars

Aims. We are studying the influence of stellar multiplicity on exoplanet systems and, in particular, systems that have been detected via radial-velocity searches. We are specifically interested in the closest companions as they would have a strong influence on the evolution of the original planet-forming disks. In this study, we present new companions that have been detected during our ongoing survey of exoplanet hosts with VLT/SPHERE (Spectro-Polarimetric High-Contrast Exoplanet Research). Methods. We are using the extreme adaptive optics imager SPHERE at the ESO/VLT to search for faint (sub)stellar companions. We utilized the classical coronagraphic imaging mode to perform a snapshot survey (3–6 min integration time) of exoplanet host stars in the Ks-band. Results. We detected new stellar companions to the exoplanet host stars HD 1666, HIP 68468, HIP 107773, and HD 109271. With an angular separation of only 0.38′′ (40 au of projected separation), HIP 107773 is among the closest companions found for exoplanet host stars. The presence of the stellar companion explains the linear radial-velocity trend seen in the system. At such a small separation, the companion likely had a significant influence on the evolution of the planet-forming disk around the primary star. We find that the companion in the HD 1666 system may well be responsible for the high orbit eccentricity (0.63) of the detected Jupiter class planet, making this system one of only a few where such a connection can be established. A cross-match with the Gaia DR2 catalog shows, furthermore, that the near infrared faint companion around HD 109271 was detected in the optical and it is significantly brighter than in the near infrared, making it a white dwarf companion.