Perfect Copies Research Articles

Assisted cloning of an unknown shared quantum state.

We first propose a novel protocol to realize quantum cloning of an arbitrary unknown shared state with assistance offered by a state preparer. The initial phase of this protocol involves the utilization of quantum teleportation (QT), enabling the transfer of quantum information from an arbitrary number of senders to another arbitrary number of receivers through a maximally entangled GHZ-type state serving as a network channel, without centralizing the information at any specific location. In the second stage of this protocol, the state preparer performs a special single-qubit projective measurement and multiple Z-basis measurements and then communicates a number of classical bits corresponding to measurement results, the perfect copy or orthogonal-complementing copy of an unknown shared state can be produced at senders hands. Then, using a non-maximally entangled GHZ-type state instead of the aforementioned quantum channel, we extend the proposed protocol from three perspectives: projective measurement, positive operator-value measurement (POVM), and a single generalized Bell-state measurement. Our schemes can relay quantum information over a network without requiring fully trusted central or intermediate nodes, and none of participants can fully access the information.

Virtual Quantum Broadcasting.

The quantum no-broadcasting theorem states that it is impossible to produce perfect copies of an arbitrary quantum state, even if the copies are allowed to be correlated. Here we show that, although quantum broadcasting cannot be achieved by any physical process, it can be achieved by a virtual process, described by a Hermitian-preserving trace-preserving map. This virtual process is canonical: it is the only map that broadcasts all quantum states, is covariant under unitary evolution, is invariant under permutations of the copies, and reduces to the classical broadcasting map when subjected to decoherence. We show that the optimal physical approximation to the canonical broadcasting map is the optimal universal quantum cloning, and we also show that virtual broadcasting can be achieved by a virtual measure-and-prepare protocol, where a virtual measurement is performed, and, depending on the outcomes, two copies of a virtual quantum state are generated. Finally, we use canonical virtual broadcasting to prove a uniqueness result for quantum states over time.

Massive ambitwistor-strings; twistorial models

Ambitwistor-strings are chiral strings whose targets are spaces of complex massless particles, and whose correlation functions directly lead to simple, compact formulae for scattering amplitudes and loop integrands for massless gauge and gravity theories. This article extends the framework to massive particles in 4d, obtained via a symmetry reduction of higher dimensional massless models based on twistors. The target space of the resulting models turns out to be the phase space of 4d massive particles in a twistorial representation, and the worldsheet theory agrees with the two-twistor string previously introduced by the authors. The paper has been written so as to be largely self-contained. We discuss two interesting classes of massive theories in detail. For gauge theories, the reduction procedure is explicitly adapted to supersymmetric gauge theories on the Coulomb branch. For supergravity theories, the reduction is adapted to give theories obtained via Cremmer, Scherk & Schwartz (CSS) reduction, with broken supersymmetry and massive multiplets. The reduction procedure gives explicit and systematic rules to obtain amplitudes for all these theories and their amplitudes from two compact master formulae that have their origins in 6d based on the polarized scattering equations; in the CSS case the formulae are new, and in both cases their derivation is systematic. The freedom to include mass allows the definition of a loop insertion operator, thereby extending the formulae to 1-loop. Unlike the massless 4d twistorial models, these all display a perfect double copy structure, here incorporating massive particles in the relationship between gauge theory and CSS supergravity amplitudes.

Convergent Evolution of Adhesive Properties in Leaf Insect Eggs and Plant Seeds: Cross-Kingdom Bioinspiration.

Plants and animals are often used as a source for inspiration in biomimetic engineering. However, stronger engagement of biologists is often required in the field of biomimetics. The actual strength of using biological systems as a source of inspiration for human problem solving does not lie in a perfect copy of a single system but in the extraction of core principles from similarly functioning systems that have convergently solved the same problem in their evolution. Adhesive systems are an example of such convergent traits that independently evolved in different organisms. We herein compare two analogous adhesive systems, one from plants seeds and one from insect eggs, to test their properties and functional principles for differences and similarities in order to evaluate the input that can be potentially used for biomimetics. Although strikingly similar, the eggs of the leaf insect Phyllium philippinicum and the seeds of the ivy gourd Coccinia grandis make use of different surface structures for the generation of adhesion. Both employ a water-soluble glue that is spread on the surface via reinforcing fibrous surface structures, but the morphology of these structures is different. In addition to microscopic analysis of the two adhesive systems, we mechanically measured the actual adhesion generated by both systems to quantitatively compare their functional differences on various standardized substrates. We found that seeds can generate much stronger adhesion in some cases but overall provided less reliable adherence in comparison to eggs. Furthermore, eggs performed better regarding repetitive attachment. The similarities of these systems, and their differences resulting from their different purposes and different structural/chemical features, can be informative for engineers working on technical adhesive systems.

Genuine multipartite entanglement of quantum states in the multiple-copy scenario

Genuine multipartite entanglement (GME) is considered a powerful form of entanglement since it corresponds to those states that are not biseparable, i.e. a mixture of partially separable states across different bipartitions of the parties. In this work we study this phenomenon in the multiple-copy regime, where many perfect copies of a given state can be produced and controlled. In this scenario the above definition leads to subtle intricacies as biseparable states can be GME-activatable, i.e. several copies of a biseparable state can display GME. We show that the set of GME-activatable states admits a simple characterization: a state is GME-activatable if and only if it is not partially separable across one bipartition of the parties. This leads to the second question of whether there is a general upper bound in the number of copies that needs to be considered in order to observe the activation of GME, which we answer in the negative. In particular, by providing an explicit construction, we prove that for any number of parties and any number k∈N there exist GME-activatable multipartite states of fixed (i.e. independent of k) local dimensions such that k copies of them remain biseparable.

Plan S the Present and Future of Open Access Publishing

Introduction:This editorial is based on a concise introduction to the basics of open access, describing what it is and showing that it is easy, fast, inexpensive, legal, and a beneficial form of academic publishing. The Internet lets us share perfect copies of our workwith a worldwide audience at virtually no cost. Working in “open access”means: digital, online, free of charge, and free of most copyright and licensing restrictions. The purposeof this paper is to provide an overview about Plan S and its significance for open access publishing. Methods: An analysis of relevant literature, sources from the internet and published literature, personal experience and observations of the author. Findings: Formerly, scholars have written peer-reviewed journal articles for impact, not for money, and are free to consent to open access without losing revenue.Open access is beneficialforauthors and readers of research.PlanSis an initiative to drive wider adoption of open access publishing whichwas launched in 2018 by cOAlitionS, an inter-national consortium of organisations who fund or carry out research. The first and main objective was to require that, from 2021, publicly funded research must only be published in journals or on platforms on an open access basis without embargo. Conclusions: There are10 principles of PlanScovering the way in which all stakeholders should work together to-wards an optimal open access future, drive service standards, promote greater transparency around costs and charges, and more fairly assess the merits of research outputs.

Transcription-Replication Coordination.

Transcription and replication are the two most essential processes that a cell does with its DNA: they allow cells to express the genomic content that is required for their functions and to create a perfect copy of this genomic information to pass on to the daughter cells. Nevertheless, these two processes are in a constant ambivalent relationship. When transcription and replication occupy the same regions, there is the possibility of conflicts between transcription and replication as transcription can impair DNA replication progression leading to increased DNA damage. Nevertheless, DNA replication origins are preferentially located in open chromatin next to actively transcribed regions, meaning that the possibility of conflicts is potentially an accepted incident for cells. Data in the literature point both towards the existence or not of coordination between these two processes to avoid the danger of collisions. Several reviews have been published on transcription–replication conflicts, but we focus here on the most recent findings that relate to how these two processes are coordinated in eukaryotes, considering advantages and disadvantages from coordination, how likely conflicts are at any given time, and which are their potential hotspots in the genome.

Tatian’s Diatessaron: The Arabic Version, the Dura Europos Fragment, and the Women Witnesses

Abstract Tatian’s Diatessaron (c. 180 CE) does not survive in its original form but only in later versions. Its content and wording, even its original language, can then be debated. However, there is a small, third-century fragment written in Greek (P. Dura 10), discovered in Dura Europos, identified as coming from the Diatessaron. Some have disputed this identification. The difficulty is that reconstructing the Diatessaron on the basis of later versions has proven problematic, so there is no agreed-upon text with which the fragment can be compared. This study presents current understandings of the Diatessaron and reviews the situation in regard to the Arabic version: a translation of the Diatessaron done in the 11th century from a Syriac text. It is argued that the Arabic Diatessaron manuscripts offer readings that are close to the Dura parchment, and this can be shown particularly in regard to the women’s presence as witnesses to the crucifixion, though there is a slightly different ordering of component parts. It is observed that the Dura fragment itself is not a perfect copy of any master text, but contains significant errors of reading, and thus it may be a writing exercise. As such it cannot be considered a definitive version of the Diatessaron, made by an expert scribe. It does, nevertheless, attempt to copy the Diatessaron, given that its content significantly overlaps with the Arabic version. This analysis uses more manuscripts than ever before assembled of the Arabic Diatessaron, so as to provide a reliable reading of the section that overlaps with the Dura fragment, and calls for a new edition, given that it provides a reasonably accurate representation of the content of Tatian’s work.

The Effect of Task Complexity on Time Estimation in the Virtual Reality Environment: An EEG Study

This paper investigated the effect of task complexity on time estimation in the virtual reality environment (VRE) using behavioral, subjective, and physiological measurements. Virtual reality (VR) is not a perfect copy of the real world, and individuals perceive time duration differently in the VRE than they do in reality. Though many researchers have found a connection between task complexity and time estimation under non-VR conditions, the influence of task complexity on time estimation in the VRE is yet unknown. In this study, twenty-nine participants performed a VR jigsaw puzzle task at two levels of task complexity. We observed that as task complexity increased, participants showed larger time estimation errors, reduced relative beta-band power at Fz and Pz, and higher NASA-Task Load Index scores. Our findings indicate the importance of controlling task complexity in the VRE and demonstrate the potential of using electroencephalography (EEG) as real-time indicators of complexity level.

Copies and Random Decision: a proposal to peacefully solve the conflict around looted art

I propose a novel approach to deal with the conflict between the present owners and the original owners of looted art. The procedure is based on perfect copying (which is possible today due to digital techniques) and random procedures (which are a means to achieve a fair outcome).

The Evidential Statistics of Genetic Assembly: Bootstrapping a Reference Sequence

The reference sequences play an essential role in genome assembly, like type specimens in taxonomy. Those references are also samples obtained at some time and location with a specific method. How can we evaluate or discriminate uncertainties of the reference itself and assembly methods? Here we bootstrapped 50 random read data sets from a small circular genome of aEscherichia colibacteriophage, phiX174, and tried to reconstruct the reference with 14 free assembly programs. Nine out of 14 assembly programs were capable of circular genome reconstruction. Unicycler correctly reconstructed the reference for 44 out of 50 data sets, but each reconstructed contig of the failed six data sets had minor defects. The other assembly software could reconstruct the reference with minor defects. The defect regions differed among the assembly programs, and the defect locations were far from randomly distributed in the reference genome. All contigs of Trinity included one, but Minia had two perfect copies other than an imperfect reference copy. The centroid of contigs for assembly programs except Unicycler differed from the reference with 75bases at most. Nonmetric multidimensional scaling (NMDS) plots of the centroids indicated that even the reference sequence was located slightly off from the estimated location of the true reference. We propose that the combination of bootstrapping a reference, making consensus contigs as centroids in an edit distance, and NMDS plotting will provide an evidential statistic way of genetic assembly for non-fragmented base sequences.

Over‐Darkening of Pulsating Aurora

AbstractRecent analyses of high‐time resolution ground‐based optical observations of pulsating aurora (PsA) have reported that the brightness of PsA sometimes decreases below the diffuse background level immediately after the ON phase of the main pulsation finishes. To date, however, the generation mechanism of such an “over‐darkening PsA” is still unclarified. In this study, we investigated the characteristics of the over‐darkening PsA by using simultaneous observations of PsA with an electron multiplying charge coupled device all‐sky camera in Sodankylä, Finland and the Arase satellite. During one of the conjunction events in Scandinavia on March 29, 2017, almost all the PsA pulses showed clear over‐darkening characteristics. By analyzing the 2D all‐sky images at the times of over‐darkening we discovered that over‐darkening areas appeared in the trailing edge of PsA patches and moved in tandem with the poleward propagating patches. It was also found that similar over‐decreasing characteristics were not seen in the chorus data from the wave instruments onboard Arase located at the magnetospheric counterpart of PsA. These results indicate that the over‐darkening PsA is not caused by a temporal variation of chorus at a fixed point, but is produced by a propagation of over‐darkening area with PsA patches. That is, the over‐darkening PsA is a result of compounding effects of spatial structure and recurrent propagation of PsA. The mechanism creating the dark area is still unknown, but the existence of over‐darkening PsA suggests that the temporal variation of PsA is not always a perfect copy of the modulation of lower‐band chorus waves in the magnetosphere.

All-Optical Optimal N-to-M Quantum Cloning of Coherent States.

The laws of quantum mechanics forbid the perfect copying of an unknown quantum state, known as the no-cloning theorem. In spite of this, approximate cloning with imperfect fidelity is possible, which opens up the field of quantum cloning. In general, quantum cloning can be divided into discrete variable and continuous variable (CV) categories. In the CV regime, all-optical implementation of the optimal N→M quantum cloning has been proposed in two original parallel works, which involves a parametric amplifier and a set of beam splitters and thus avoids the optic-electro and electro-optic conversions in the current CV quantum cloning technologies. However, such original proposal of all-optical CV optimal N→M quantum cloning scheme has never been experimentally implemented. Here, we show that optimal N→M quantum cloning of coherent states can be realized by utilizing a parametric amplifier based on four-wave mixing process in a hot atomic vapor and a set of beam splitters. In particular, we realize 1→M, 2→M, and 4→M quantum cloning. We find that the fidelity of N→M quantum cloning increases with the decrease of clone number M and the increase of original replica number N. The best cloning fidelity achieved in our experiment is about 93.3% ±1.0% in the 4→5 case. Our results may find potential applications in realizing all-optical high-fidelity quantum state transfer and all-optical high-compatibility eavesdropping attack in quantum communication networks.

New Evidence for Ben Jonson’s Epigrammes (ca. 1612) in Bodleian Library Records

New Evidence for Ben Jonson’s <i>Epigrammes</i> (ca. 1612) in Bodleian Library Records

Unusual mtDNA Control Region Length Heteroplasmy in the COS-7 Cell Line.

The COS-7 cell line is a workhorse of virology research. To expand this cell line’s utility and to enable studies on mitochondrial DNA (mtDNA) transcription and replication, we determined the complete nucleotide sequence of its mitochondrial genome by Sanger sequencing. In contrast to other available mtDNA sequences from Chlorocebus aethiops, the mtDNA of the COS-7 cell line was found to contain a variable number of perfect copies of a 108 bp unit tandemly repeated in the control region. We established that COS-7 cells are heteroplasmic with at least two variants being present: with four and five repeat units. The analysis of the mitochondrial genome sequences from other primates revealed that tandem repeats are absent from examined mtDNA control regions of humans and great apes, but appear in lower primates, where they are present in a homoplasmic state. To our knowledge, this is the first report of mtDNA length heteroplasmy in primates.

The Shanxi Grand Theater: The “Renaissance” of Chinese Drama Land

ThispaperfocusesonTaiyuancity,asecond-tierChinesecitywithabrillianthistorythat had been gradually reduced to mediocrity. When an ambitious governor took office, he planned to carry out an urban revitalization process in which cultural facilities would become symbols of power and represent the city’s identity or define its character. The importation of western-style architecture and urban design for the performing arts offer a way out. The ‘perfect copies’ of European lifestyle, through the way of architectural, urbanism transplant, seemed to serve as a potent symbol of China authority’s ability to control and rearrange the worldwide intelligence for their citizen. The authors investigated Taiyuan and its performance spaces, examine the Shanxi Grand Theatre in terms of designs, layouts and uses, expectations, and disappointments in spatial terms both within and in relation to urban spaces, which epitomized China’s strategy on balancing the elite cultural monuments and social welfare.

Digital fabrication of cultural heritage artwork replicas. In the search for resilience and socio-cultural commitment

The traditional approach for physical reproduction in Cultural Heritage requires the production of moulds on the very surface of the original artwork in an invasive, manual and usually time-consuming process that is intensely influenced by the complexity of the piece to be reproduced. The difficulties increase when changing the size of the copy is needed. But producing replicas is a necessity, mostly when it comes to mounting exhibitions within interpretive centres. The educational role of such institutions is beyond doubt. Furthermore, they have also become major drivers of social inclusion of at-risk groups. So, having perfect copies of archaeological remains without damaging them is a challenge that technology has been facing for the last years. This paper describes a procedure to obtain exact replicas of classical statues that reduces their manipulation, thus preventing them for further damages, which was applied to two Roman marble sculptures of Medellín (Badajoz, Spain).

Art and achievement

An increasingly popular view in the philosophy of art is that some artworks are good artworks at least partly because they are achievements. This view was introduced to explain why two works that look the same, such as an original painting and a perfect copy, can differ in artistic merit. An achievement theory can say that the original is better because it is a greater achievement. Achievement theories have since been used to answer other questions, and they are now a serious alternative to traditional theories of artistic merit. This paper has three aims. The first is to articulate the achievement theory more fully and explicitly than its advocates have. The second is to show that the achievement theory should be rejected, by raising five problems for it. The third is to show that appealing solely to the excellence, aptitude, and ineptitude a work manifests yields a better theory of artistic merit.

The perfect true copy: manuscript as evidence in seventeenth-century vernacular English news and medical books

The seventeenth-century London press proliferated titles purporting to reveal new truths gleaned from secret papers and private mailbags. These books, whether political, religious, or scientific in content, promised to reveal to the reader the complex (and sometimes scandalous) inner workings of political, social, and natural processes. They did so via the mechanism of the “perfect true copy”: the printed book or pamphlet that was (or claimed to be) an exact copy of private manuscript papers, whether nabbed or voluntarily released from the mailbags and closets of the prominent, the highborn, the powerful, or the learned. This article investigates the relations between printed copy and manuscript original in two cases where medical, natural philosophical, and political controversy overlapped: the mid-1650s posthumous publication (and forgery) of works by the astrological medical practitioner Nicholas Culpeper and the performance of Valentine Greatrakes, the Irish Stroker, as a faith healer in Restoration London. In each case, controversialists pointed to manuscript material as a secure record that backed up points being made in printed pamphlets and books, even inviting readers to check manuscript originals physically (often referred to as “copy”: that from which printed copies were made). These case studies engage with questions of gender and women’s credibility in print, authoring, and authorizing, both texts and medical expertise. Within the world of cheap vernacular medical print, and pamphlet controversy, women themselves, as well as male associates, such as stationers and husbands, used women’s knowledge and domestic positions—which encompassed their connections to manuscript copy—to certify printed texts and cures.

Johannes Semper hobusega. Avangard, takerduja tehnika ja looduse vahel / Johannes Semper with a horse: Avant-garde between technology and nature

Artikkel annab ülevaate 20. sajandi alguse kirjandusliku avangardi suhetest tehnikaga. Avangardi (eriti futurismi) jaoks pidi tehnika saama loomise eeskujuks ja masinate seadused esteetilise loovuse seadusteks. Artikkel väidab, et paljud avangardi tekstiuuenduslikud ideaalid on vastuolus tehnika ideaalidega ja iseloomustavad ennekõike loodust. Tehnika väärtustas tulemust, avangard protsessi. Tehnika väärtustas süsteemsust, ennustatavust, koopialisust, avangard vabarütme, ennustamatust ja originaalsust. Tehnika nõudis ratsionaalsust ja eesmärgipärast tegutsemist, avangard kuulutas intuitsiooni ja prohvetlikku kujutlust. Tehnika tõi odavad masstooted, avangard hindas haruldust. Tehnika väärtustas funktsionaalsust, avangard ebafunktsionaalsust. Tehnika väärtustas puhtust ja hügieeni, avangard järgis inetuse esteetikat. Tehnika nõudis tootmises vigade ja häirete vältimist, avangard tõstis vea loovaks ideeks.&#x0D; &#x0D; The article examines the relationship between the early twentieth century international and Estonian literary avant-garde and new technology, which radically changed life and interpersonal relationships in Europe and America (trains, airplanes, metro, telephone, telegraph, skyscrapers, fast food, etc.).&#x0D; At first, I highlight general features connecting the new technology and its products, which emerged in distinct opposition to nature. The central activity in the world of technology appeared to be efficient, planned, and purposeful production, in which the main agents were engineer, designer, and worker. The new technology emphasized the value of the product, which rapidly became standardized and cheaply made mass-produced perfect copies of each other. The beauty of the new era was to be a technological, functionalist beauty. Production as a process had to operate without failures and the ideal product had to be without any defects. Therefore, the technological process had to be clean, even hygienic. The new technology established its own rhythm in modern cities, characterized by repeatability and predictability. At the same time, the technology covered cities by the voices that made up the noise of technology.&#x0D; It could be said, even, that the new technology exceeded the limits of time and space. The result was a world of simultaneity. At the same time, relationships and links between people became increasingly loose and the world and man’s worldview was characterized by increasing fragmentation.&#x0D; The early European avant-garde at the beginning of the twentieth century greeted the new world of technology and speed with great enthusiasm (Italian futurism, constructivism, etc.). Perhaps only early expressionism and Russian futurism had even more ambivalent attitude to the technology. The First World War significantly decreased the pre-war fascination with technology. The war destroyed the faith in the machines; the machine now became a destroyer, and the new mechanical man (a fusion of man and machine) came into view as a killer with killed soul. At the same time, modern technology became more and more common in the everyday life, and, hence, the attitude towards technology changed. The technology became a harrowing phenomenon.&#x0D; For early European avant-garde, the new technology was supposed to become a model for the creation and laws of machines laws of aesthetic creativity (Marinetti). We can find several features in the texts of avant-garde (especially in poetry), which are in accordance with the new world of speed and technology.&#x0D; Simultaneous and fragmented text represented simultaneity and fragmentarity of the world. The speed was intermediated by the telegram style, parataxis, glossolalia, onomatopoeia, mathematical symbols, etc. The artist’s ideal was engineer and machine had to become a model for making the text. I present examples of such new texts in Estonian avant-garde poetry and prose.&#x0D; However, much of the avant-garde ideas and ideals for textual innovation contradicted the ideals of technology. Whilst technology predominantly esteemed the result, the avant-garde valued the process of making the text. In addition, the world of technology expected systematics, predictability, repetitive rhythms, and copies while avant-garde proclaimed free rhythms, free verse, unpredictability, and originality. Technology insisted on rational and purposeful acting; avant-garde proclaimed intuition and prophetic imagination. Technology brought cheap mass products; avant-garde appreciated the rarity and expensiveness. Technology promoted utilitarianism and functionality; avant-garde non-functionality. Technology put stress on the cleanliness and hygiene of the products; avant-garde often followed the aesthetics of ugliness. Technology required efficiency and economy of production, avoiding mistakes and disturbances; avant-garde regarded error as a creative idea.&#x0D; I argue that many of these avant-garde ideas are very similar to nature. For example, chaos, illogicality, glossolalia, words-in-freedom, and zaum truly characterize nature. Originality, variability, unpredictable rhythms, non-systematicity are also the qualities of nature. Lack of purpose, irrationality, and lack of thought are features of nature. An error or a shift as the basis of creation and inefficiency characterizes nature, too. The aesthetics of ugliness parallels the ugliness of nature.&#x0D; Thus, the observance of the avant-garde ideals results in a text that, on the one hand, craves the world of technology and machines, but on the other hand goes back to the ideas and ideals of nature and seeks solutions largely in the same way as nature.