The analysis of proteins in the gas phase benefits from detectors that exhibit high efficiency and precise spatial resolution. Although modern secondary electron multipliers already address numerous analytical requirements, additional methods are desired for macromolecules at energies lower than currently used in post-acceleration detection. Previous studies have proven the sensitivity of superconducting detectors to high-energy particles in time-of-flight mass spectrometry. Here, we demonstrate that superconducting nanowire detectors are exceptionally well suited for quadrupole mass spectrometry and exhibit an outstanding quantum yield at low-impact energies. At energies as low as 100 eV, the sensitivity of these detectors surpasses conventional ion detectors by three orders of magnitude, and they offer the possibility to discriminate molecules by their impact energy and charge. We demonstrate three developments with these compact and sensitive devices, the recording of 2D ion beam profiles, photochemistry experiments in the gas phase, and advanced cryogenic electronics to pave the way toward highly integrated detectors.
Crime, poverty and survival in the Middle East and North Africa: the ‘dangerous classes’ since 1800 Crime, poverty and survival in the Middle East and North Africa: the ‘dangerous classes’ since 1800 , edited by Stephanie Cronin (London: I.B. Tauris, 2019), 315 pp., £29.99 (paperback), £100 (hardback). ISBN 9780755645015; 9781788313711: Edited by Stephanie Cronin, London, I.B. Tauris, 2019, 315 pp., £29.99 (paperback), £100 (hardback). ISBN 9780755645015; 9781788313711
Planets with radii between that of the Earth and Neptune (hereafter referred to as ‘sub-Neptunes’) are found in close-in orbits around more than half of all Sun-like stars1,2. However, their composition, formation and evolution remain poorly understood³. The study of multiplanetary systems offers an opportunity to investigate the outcomes of planet formation and evolution while controlling for initial conditions and environment. Those in resonance (with their orbital periods related by a ratio of small integers) are particularly valuable because they imply a system architecture practically unchanged since its birth. Here we present the observations of six transiting planets around the bright nearby star HD 110067. We find that the planets follow a chain of resonant orbits. A dynamical study of the innermost planet triplet allowed the prediction and later confirmation of the orbits of the rest of the planets in the system. The six planets are found to be sub-Neptunes with radii ranging from 1.94R⊕ to 2.85R⊕. Three of the planets have measured masses, yielding low bulk densities that suggest the presence of large hydrogen-dominated atmospheres.
Entanglement is a distinguishing feature of quantum many-body systems, and uncovering the entanglement structure for large particle numbers in quantum simulation experiments is a fundamental challenge in quantum information science¹. Here we perform experimental investigations of entanglement on the basis of the entanglement Hamiltonian (EH)² as an effective description of the reduced density operator for large subsystems. We prepare ground and excited states of a one-dimensional XXZ Heisenberg chain on a 51-ion programmable quantum simulator³ and perform sample-efficient ‘learning’ of the EH for subsystems of up to 20 lattice sites⁴. Our experiments provide compelling evidence for a local structure of the EH. To our knowledge, this observation marks the first instance of confirming the fundamental predictions of quantum field theory by Bisognano and Wichmann5,6, adapted to lattice models that represent correlated quantum matter. The reduced state takes the form of a Gibbs ensemble, with a spatially varying temperature profile as a signature of entanglement². Our results also show the transition from area- to volume-law scaling⁷ of von Neumann entanglement entropies from ground to excited states. As we venture towards achieving quantum advantage, we anticipate that our findings and methods have wide-ranging applicability to revealing and understanding entanglement in many-body problems with local interactions including higher spatial dimensions.
An analysis is given of the local phase space of gravity coupled to matter to second order in perturbation theory. Working in local regions with boundaries at finite distance, we identify matter, Coulomb, and additional boundary modes. The boundary modes take the role of reference frames for both diffeomorphisms and internal Lorentz rotations. Passing to the quantum level, we identify the constraints that link the bulk and boundary modes. The constraints take the form of a multifingered Schrödinger equation, which determines the relational evolution of the quantum states in the bulk with respect to the quantum reference fields for the local gravitational symmetries at the boundary. Taking the boundary to infinity, we obtain quantum reference frames for asymptotic symmetries.
This article revisits the interaction between regular ‘Neogrammarian’ sound change (defined as a purely phonological process) and subsequent morphological change (especially changes subsumed under the term ‘analogy’) in the development of the outcomes of Brugmann's Law (BL) in Indo‐Iranian. The traditional formulation of BL states that Proto‐Indo‐European * o became Indo‐Iranian /ā/ in open syllables and /a/ elsewhere, positing a purely phonological context of application. Alternatively, Kiparsky (2010) has argued for a revised version of BL in which the accent and ablaut properties of the affected forms play a role, hence essentially for a synchronic morphophonological rule. I argue that this revised version fails both from the perspective of comparative reconstruction and as a synchronic rule based on a detailed study of the forms cited as evidence for the revised rule. Rather, in order to identify inherited * o in Indo‐Iranian the effects of the ‘blind’ Neogrammarian rule must be separated from the synchronic morphological rules of the attested languages. This paper thus makes a methodological contribution in defence of the Neogrammarian approach to sound change, but also an empirical contribution by showing that this approach, in combination with a strictly lexical definition of analogy, can account for some conspicuous exceptions to traditional BL.
Lawrence et al. have presented an argument purporting to show that “relative facts do not exist” and, consequently, “Relational Quantum Mechanics is incompatible with quantum mechanics”. The argument is based on a GHZ-like contradiction between constraints satisfied by measurement outcomes in an extended Wigner’s friend scenario. Here we present a strengthened version of the argument, and show why, contrary to the claim by Lawrence et al., these arguments do not contradict the consistency of a theory of relative facts. Rather, considering this argument helps clarify how one should not think about a theory of relative facts, like RQM.
Objectives Estimating the sex of cremated human remains is difficult. The petrous bone frequently survives the cremation due to its density. Wahl observed the lateral angle to be sexually dimorphic in the 1980s. Previous studies showed various cut‐off points to separate females from males, which are hardly replicable and difficult to apply. We want to test the Wahl method and compare it to a new landmark‐based version. Materials and Methods In this study, we measured the lateral angle of 35 cremated petrous bones from late bronze age Austria using micro‐CT scans. Technical errors of measurement were calculated for two different methods to intersect the internal acoustic meatus virtually in the midline (manual or landmark‐based intersection). Furthermore, sex was estimated based on morphological features and metric measurements. This information was used in logistic regression modeling to define a cut‐off point in our sample. Results The technical errors of measurement suggested that a landmark‐based method was more precise in comparison to a manual intersection which was much more intuitive. Inter‐ and intra‐observer errors were low which improved reliability. The logistic regression model produced good results in our sample ( p = 0.02, R 2 = 0.38, accuracy = 0.8). The mean lateral angle was similar to studies which focused on prehistoric cremated petrous bones. Discussion The proposed landmark‐based method was precise, quick, and could be easily applied, even by unexperienced researchers. The size of the lateral angle seemed to be population‐specific but also dependent on the method applied. We recommend to use the proposed landmark‐based method which is more precise.
We analyze the local dynamics of magnetotail reconnection onset using Magnetospheric Multiscale (MMS) data. In conjunction with MMS, the macroscopic dynamics of this event were captured by a number of other ground and space‐based observatories, as is reported in a companion paper. We find that the local dynamics of the onset were characterized by the rapid thinning of the cross‐tail current sheet below the ion inertial scale, accompanied by the growth of flapping waves and the subsequent onset of electron tearing. Multiple kinetic‐scale magnetic islands were detected coincident with the growth of an initially sub‐Alfvénic, demagnetized tailward ion exhaust. The onset and rapid enhancement of parallel electron inflow at the exhaust boundary was a remote signature of the intensification of reconnection Earthward of the spacecraft. Two secondary reconnection sites are found embedded within the exhaust from a primary X‐line. The primary X‐line was designated as such on the basis that (a) while multiple jet reversals were observed in the current sheet, only one reversal of the electron inflow was observed at the high‐latitude exhaust boundary, (b) the reconnection electric field was roughly five times larger at the primary X‐line than the secondary X‐lines, and (c) energetic electron fluxes increased and transitioned from anti‐field‐aligned to isotropic during the primary X‐line crossing, indicating a change in magnetic topology. The results are consistent with the idea that a primary X‐line mediates the reconnection of lobe magnetic field lines and accelerates electrons more efficiently than its secondary X‐line counterparts.
In 2021 and 2022, the 13th and 14th seasons of excavations at the Late Bronze Age site of Hala Sultan Tekke were carried out in Area A, and as a result of these investigations numerous tombs were found. These tombs were threatened by farming. Four magnetic anomalies, indicated in the 2017 survey magnetometer map, were investigated. They represent three tombs, L198, TT, and UU, and the probable Offering Pit SS-S. The minimum number of individuals (MNI) in Pit Tomb L198, which contains only secondary burials, is six. They are associated with 21 ceramic vessels of which a few were imported from Anatolia. Chamber Tomb TT was completely excavated and contained a minimum of 25 individuals and 78 objects. Among these are 47 ceramic vessels of which a few are from the Mycenaean sphere of culture. Other mortuary gifts are various objects of metal, faience, carnelian, haematite, and rock crystal in addition to three scarabs. The incompletely excavated large (Chamber?) Tomb UU contained, so far, a minimum of 19 individuals and 140 objects. They comprise 124 ceramic vessels including numerous Late Helladic, Late Minoan, and Anatolian pottery. Other finds are bronze and gold jewellery, the latter including a diadem, and a duck-shaped ivory box from the same context as Egyptian-imported vessels of calcite. None of the tombs and the offering pit, which can all be roughly dated to the 14th century BC, were looted. The special arrangements of the human bones in Chamber Tomb TT and the multitude of imported materials in Tomb UU offer additional insights into complex Late Cypriot mortuary practices and the far-reaching interregional connections of the urban élites of Hala Sultan Tekke.
The performance of quantum information protocols can be impacted by the noninertial motion of parties such as in a gravitational field. Previous studies have primarily focused on the degradation of entanglement for global modes, revealing that bipartite entanglement vanishes in the limit of large acceleration, whereas tripartite entanglement does not. In this study, we examine the impact of acceleration on tripartite Gaussian resource states encoded in spatially localized wave packets. Contrarily to prior findings, we observe that genuine tripartite entanglement (GTE) vanishes in the limit of large acceleration for various initial states and observer trajectories.
The ancient southern Levantine city of Gezer is well-known from Egyptian, Biblical and Assyrian sources, associated with power struggles, conquests, and intriguing tales involving figures such as Milkilu and Amenhotep III, Merneptah, the Philistines, Solomon and his unidentified pharaonic father-in-law, and Shishak / Sheshonq I. Since the identity of Gezer with “Tell Jezer” is quite literally ‘set in stone’ by some dozen boundary inscriptions, along with impressive Bronze and Iron Age remains, research at this site provides a unique opportunity to compare text and archaeology, as well as bring to light the undocumented everyday lives of the city’s inhabitants. In this endeavour, independent scientific dating is crucial for anchoring the remains chronologically. This paper presents the first substantial radiocarbon dataset and Bayesian chronological analysis for Gezer spanning the last part of the Late Bronze Age (LBA; LB IIB) through Iron Age II. The dataset derives from an essentially continuous stratigraphic sequence exposed in recent years by the Tandy expedition along the central-southern edge of the site. The results allow us for the first time to independently determine the site chronology, test the viability (from a chronological perspective) of proposed historical correlations, and contribute to debates on Philistine and Iron Age chronology.
By assuming a type of balance for length ℓ = 87 \ell =87 and nontrivial subgroups of multiplier groups of Legendre pairs (LPs) for length ℓ = 85 \ell =85 , we find LPs of these lengths. We then study the power spectral density (PSD) values of m m compressions of LPs of length 5 m 5m . We also formulate a conjecture for LPs of lengths ℓ ≡ 0 \ell \equiv 0 (mod 5) and demonstrate how it can be used to decrease the search space and storage requirements for finding such LPs. The newly found LPs decrease the number of integers in the range ≤ 200 \le 200 for which the existence question of LPs remains unsolved from 12 to 10.
The quantum switch is a quantum process that creates a coherent control between different unitary operations, which is often described as a quantum process which transforms a pair of unitary operations ( U 1 , U 2 ) into a controlled unitary operation that coherently applies them in different orders as | 0 ⟩ ⟨ 0 | ⊗ U 1 U 2 + | 1 ⟩ ⟨ 1 | ⊗ U 2 U 1 . This description, however, does not directly define its action on non-unitary operations. The action of the quantum switch on non-unitary operations is then chosen to be a ``natural'' extension of its action on unitary operations. In general, the action of a process on non-unitary operations is not uniquely determined by its action on unitary operations. It may be that there could be a set of inequivalent extensions of the quantum switch for non-unitary operations. We prove, however, that the natural extension is the only possibility for the quantum switch for the 2-slot case. In other words, contrary to the general case, the action of the quantum switch on non-unitary operations (as a linear and completely CP preserving supermap) is completely determined by its action on unitary operations. We also discuss the general problem of when the complete description of a quantum process is uniquely determined by its action on unitary operations and identify a set of single-slot processes which are completely defined by their action on unitary operations.
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