Device-independent quantum randomness-enhanced zero-knowledge proof.

Zero-knowledge proof (ZKP) is a fundamental cryptographic primitive that allows a prover to convince a verifier of the validity of a statement without leaking any further information. As an efficient variant of ZKP, noninteractive zero-knowledge proof (NIZKP) adopting the Fiat-Shamir heuristic is essential to a wide spectrum of applications, such as federated learning, blockchain, and social networks. However, the heuristic is typically built upon the random oracle model that makes ideal assumptions about hash functions, which does not hold in reality and thus undermines the security of the protocol. Here, we present a quantum solution to the problem. Instead of resorting to a random oracle model, we implement a quantum randomness service. This service generates random numbers certified by the loophole-free Bell test and delivers them with postquantum cryptography (PQC) authentication. By employing this service, we conceive and implement NIZKP of the three-coloring problem. By bridging together three prominent research themes, quantum nonlocality, PQC, and ZKP, we anticipate this work to inspire more innovative applications that combine quantum information science and the cryptography field.

Device-independent quantum random-number generation.

Randomness is important for many information processing applications, including numerical modelling and cryptography1,2. Device-independent quantum random-number generation (DIQRNG)3,4 based on the loophole-free violation of a Bell inequality produces genuine, unpredictable randomness without requiring any assumptions about the inner workings of the devices, and is therefore an ultimate goal in the field of quantum information science5-7. Previously reported experimental demonstrations of DIQRNG8,9 were not provably secure against the most general adversaries or did not close the 'locality' loophole of the Bell test. Here we present DIQRNG that is secure against quantum and classical adversaries10-12. We use state-of-the-art quantum optical technology to create, modulate and detect entangled photon pairs, achieving an efficiency of more than 78 per cent from creation to detection at a distance of about 200 metres that greatly exceeds the threshold for closing the 'detection' loophole of the Bell test. By independently and randomly choosing the base settings for measuring the entangled photon pairs and by ensuring space-like separation between the measurement events, we also satisfy the no-signalling condition and close the 'locality' loophole of the Bell test, thus enabling the realization of the loophole-free violation of a Bell inequality. This, along with a high-voltage, high-repetition-rate Pockels cell modulation set-up, allows us to accumulate sufficient data in the experimental time to extract genuine quantum randomness that is secure against the most general adversaries. By applying a large (137.90 gigabits × 62.469 megabits) Toeplitz-matrix hashing technique, we obtain 6.2469 × 107 quantum-certified random bits in 96 hours with a total failure probability (of producing a random number that is not guaranteed to be perfectly secure) of less than 10-5. Our demonstration is a crucial step towards transforming DIQRNG from a concept to a key aspect of practical applications that require high levels of security and thus genuine randomness7. Our work may also help to improve our understanding of the origin of randomness from a fundamental perspective.

Physiological and Biochemical Properties of Cotton Seedlings in Response to Cu2+ Stress.

Copper(II) (Cu2+) is essential for plant growth and development. However, high concentrations are extremely toxic to plants. We investigated the tolerance mechanism of cotton under Cu2+ stress in a hybrid cotton variety (Zhongmian 63) and two parent lines with different Cu2+ concentrations (0, 0.2, 50, and 100 µM). The stem height, root length, and leaf area of cotton seedlings had decreased growth rates in response to increasing Cu2+ concentrations. Increasing Cu2+ concentration promoted Cu2+ accumulation in all three cotton genotypes' roots, stems, and leaves. However, compared with the parent lines, the roots of Zhongmian 63 were richer in Cu2+ and had the least amount of Cu2+ transported to the shoots. Moreover, excess Cu2+ also induced changes in cellular redox homeostasis, causing accumulation of hydrogen peroxide (H2O2) and malondialdehyde (MDA). Conversely, antioxidant enzyme activity increased, while photosynthetic pigment content decreased. Our findings indicated that the hybrid cotton variety fared well under Cu2+ stress. This creates a theoretical foundation for the further analysis of the molecular mechanism of cotton resistance to copper and suggests the potential of the large-scale planting of Zhongmian 63 in copper-contaminated soils.

Quantum Complementarity Approach to Device-Independent Security.

Complementarity is an essential feature of quantum mechanics. The preparation of an eigenstate of one observable implies complete randomness in its complementary observable. In quantum cryptography, complementarity allows us to formulate security analyses in terms of phase-error correction. However, the concept becomes much subtler in the device-independent regime that offers security without device characterization. Security proofs of device-independent quantum cryptography tasks are often complex and quite different from those of their more standard device-dependent cousins. The existing proofs pose huge challenges to experiments, among which large data-size requirement is a crux. Here, we show the complementarity security origin of the device-independent tasks. By linking complementarity with quantum nonlocality, we recast the device-independent scheme into a quantum error correction protocol. Going beyond the identical-and-independent-distribution case, we consider the most general attack. We generalize the sample entropy in classical Shannon theory for the finite-size analysis. Our method exhibits good finite-size performance and brings the device-independent scheme to a more practical regime. Applying it to the data in a recent ion-trap-based device-independent quantum key distribution experiment, one could reduce the requirement on data size to less than a third. Furthermore, the operational meaning of complementarity naturally extends device-independent scenarios to advantage key distillation, easing experiments by tolerating higher loss and lower transmittance.

Experimental Mode-Pairing Measurement-Device-Independent Quantum Key Distribution without Global Phase Locking.

In the past two decades, quantum key distribution networks based on telecom fibers have been implemented on metropolitan and intercity scales. One of the bottlenecks lies in the exponential decay of the key rate with respect to the transmission distance. Recently proposed schemes mainly focus on achieving longer distances by creating a long-arm single-photon interferometer over two communication parties. Despite their advantageous performance over long communication distances, the requirement of phase locking between two remote lasers is technically challenging. By adopting the recently proposed mode-pairing idea, we realize high-performance quantum key distribution without global phase locking. Using two independent off-the-shelf lasers, we show a quadratic key-rate improvement over the conventional measurement-device-independent schemes in the regime of metropolitan and intercity distances. For longer distances, we also boost the key rate performance by 3 orders of magnitude via 304 km commercial fiber and 407 km ultralow-loss fiber. We expect this ready-to-implement high-performance scheme to be widely used in future intercity quantum communication networks.

Scalable Multipartite Entanglement Created by Spin Exchange in an Optical Lattice.

Ultracold atoms in optical lattices form a competitive candidate for quantum computation owing to the excellent coherence properties, the highly parallel operations over spins, and the ultralow entropy achieved in qubit arrays. For this, a massive number of parallel entangled atom pairs have been realized in superlattices. However, the more formidable challenge is to scale up and detect multipartite entanglement, the basic resource for quantum computation, due to the lack of manipulations over local atomic spins in retroreflected bichromatic superlattices. In this Letter, we realize the functional building blocks in quantum-gate-based architecture by developing a cross-angle spin-dependent optical superlattice for implementing layers of quantum gates over moderately separated atoms incorporated with a quantum gas microscope for single-atom manipulation and detection. Bell states with a fidelity of 95.6(5)% and a lifetime of 2.20±0.13 s are prepared in parallel, and then connected to multipartite entangled states of one-dimensional ten-atom chains and two-dimensional plaquettes of 2×4 atoms. The multipartite entanglement is further verified with full bipartite nonseparability criteria. This offers a new platform toward scalable quantum computation and simulation.

Roles of S-Adenosylmethionine and Its Derivatives in Salt Tolerance of Cotton.

Salinity is a major abiotic stress that restricts cotton growth and affects fiber yield and quality. Although studies on salt tolerance have achieved great progress in cotton since the completion of cotton genome sequencing, knowledge about how cotton copes with salt stress is still scant. S-adenosylmethionine (SAM) plays important roles in many organelles with the help of the SAM transporter, and it is also a synthetic precursor for substances such as ethylene (ET), polyamines (PAs), betaine, and lignin, which often accumulate in plants in response to stresses. This review focused on the biosynthesis and signal transduction pathways of ET and PAs. The current progress of ET and PAs in regulating plant growth and development under salt stress has been summarized. Moreover, we verified the function of a cotton SAM transporter and suggested that it can regulate salt stress response in cotton. At last, an improved regulatory pathway of ET and PAs under salt stress in cotton is proposed for the breeding of salt-tolerant varieties.

GhAP1-D3 positively regulates flowering time and early maturity with no yield and fiber quality penalties in upland cotton.

Flowering time (FTi) is a major factor determining how quickly cotton plants reach maturity. Early maturity greatly affects lint yield and fiber quality and is crucial for mechanical harvesting of cotton in northwestern China. Yet, few quantitative trait loci (QTLs) or genes regulating early maturity have been reported in cotton, and the underlying regulatory mechanisms are largely unknown. In this study, we characterized 152, 68, and 101 loci that were significantly associated with the three key early maturity traits-FTi, flower and boll period (FBP) and whole growth period (WGP), respectively, via four genome-wide association study methods in upland cotton (Gossypium hirsutum). We focused on one major early maturity-related genomic region containing three single nucleotide polymorphisms on chromosome D03, and determined that GhAP1-D3, a gene homologous to Arabidopsis thaliana APETALA1 (AP1), is the causal locus in this region. Transgenic plants overexpressing GhAP1-D3 showed significantly early flowering and early maturity without penalties for yield and fiber quality compared to wild-type (WT) plants. By contrast, the mutant lines of GhAP1-D3 generated by genome editing displayed markedly later flowering than the WT. GhAP1-D3 interacted with GhSOC1 (SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1), a pivotal regulator of FTi, both in vitro and in vivo. Changes in GhAP1-D3 transcript levels clearly affected the expression of multiple key flowering regulatory genes. Additionally, DNA hypomethylation and high levels of H3K9ac affected strong expression of GhAP1-D3 in early-maturing cotton cultivars. We propose that epigenetic modifications modulate GhAP1-D3 expression to positively regulate FTi in cotton through interaction of the encoded GhAP1 with GhSOC1 and affecting the transcription of multiple flowering-related genes. These findings may also lay a foundation for breeding early-maturing cotton varieties in the future.

Glucose regulates cotton fiber elongation by interacting with brassinosteroid.

In plants, glucose (Glc) plays important roles, as a nutrient and signal molecule, in the regulation of growth and development. However, the function of Glc in fiber development of upland cotton (Gossypium hirsutum) is unclear. Here, using gas chromatography-mass spectrometry (GC-MS), we found that the Glc content in fibers was higher than that in ovules during the fiber elongation stage. In vitro ovule culture revealed that lower Glc concentrations promoted cotton fiber elongation, while higher concentrations had inhibitory effects. The hexokinase inhibitor N-acetylglucosamine (NAG) inhibited cotton fiber elongation in the cultured ovules, indicating that Glc-mediated fiber elongation depends on the Glc signal transduced by hexokinase. RNA sequencing (RNA-seq) analysis and hormone content detection showed that 150mM Glc significantly activated brassinosteroid (BR) biosynthesis, and the expression of signaling-related genes was also increased, which promoted fiber elongation. In vitro ovule culture clarified that BR induced cotton fiber elongation in a dose-dependent manner. In hormone recovery experiments, only BR compensated for the inhibitory effects of NAG on fiber elongation in a Glc-containing medium. However, the ovules cultured with the BR biosynthetic inhibitor brassinazole and from the BR-deficient cotton mutant pag1 had greatly reduced fiber elongation at all the Glc concentrations tested. This demonstrates that Glc does not compensate for the inhibition of fiber elongation caused by BR biosynthetic defects, suggesting that the BR signaling pathway works downstream of Glc during cotton fiber elongation. Altogether, our study showed that Glc plays an important role in cotton fibre elongation, and crosstalk occurs between Glc and BR signaling during modulation of fiber elongation.

Fundamental Limitation on the Detectability of Entanglement.

Entanglement detection is essential in quantum information science and quantum many-body physics. It has been proved that entanglement exists almost surely for a random quantum state, while the realizations of effective entanglement criteria usually consume exponentially many resources with regard to system size or qubit number, and efficient criteria often perform poorly without prior knowledge. This fact implies a fundamental limitation might exist in the detectability of entanglement. In this work, we formalize this limitation as a fundamental trade-off between the efficiency and effectiveness of entanglement criteria via a systematic method to evaluate the detection capability of entanglement criteria theoretically. For a system coupled to an environment, we prove that any entanglement criterion needs exponentially many observables to detect the entanglement effectively when restricted to single-copy operations. Otherwise, the detection capability of the criterion will decay double exponentially. Furthermore, if multicopy joint measurements are allowed, the effectiveness of entanglement detection can be exponentially improved, which implies a quantum advantage in entanglement detection problems. Our results may shed light on why quantum phenomena are difficult to observe in large noisy systems.

Detecting Entanglement in Quantum Many-Body Systems via Permutation Moments.

Multipartite entanglement plays an essential role in both quantum information science and many-body physics. Because of the exponentially large dimension and complex geometric structure of the state space, the detection of entanglement in many-body systems is extremely challenging in reality. Conventional means, like entanglement witness and entropy criterion, either highly depend on the prior knowledge of the studied systems or the detection capability is relatively weak. In this Letter, we propose a framework for designing multipartite entanglement criteria based on permutation moments, which have an effective implementation with either the generalized control-swap quantum circuits or the random unitary techniques. As an example, in the bipartite scenario, we develop an entanglement criterion that can detect bound entanglement and show strong detection capability in the multiqubit Ising model with a long-range XY Hamiltonian. In the multipartite case, the permutation-moment-based criteria can detect entangled states that are not detectable by any criteria extended from the bipartite case. Our framework also shows potential in entanglement quantification and entanglement structure detection.

Near-Infrared Light-Driven Photoredox Catalysis by Transition-Metal-Complex Nanodots.

Developing light-harvesting materials with broad spectral response is of fundamental importance in full-spectrum solar energy conversion. We found that, when a series of earth-abundant metal (Cu, Co, Ni and Fe) salts are dissolved in coordinating solvents uniformly dispersed nanodots (NDs) are formed rather than fully dissolving as molecular species. The previously unrecognized formation of this condensed state is ascribed to spontaneous aggregation of molecular transition-metal-complexes (TMCs) via weak intermolecular interactions, which results in redshifted and broadened absorption into the NIR region (200-1100 nm). Typical photoredox reactions, such as carbonylation and oxidative dehydrogenation, well demonstrate the feasibility of efficient utilization of NIR light (λ>780 nm) by TMCs NDs. Our finding provides a conceptually new strategy for extending the absorption towards low energy photons in solar energy harvesting and conversion via photoredox transformations.

Functional gene assessment of bread wheat: breeding implications in Ningxia Province.

BACKGROUND: The overall genetic distribution and divergence of cloned genes among bread wheat varieties that have occurred during the breeding process over the past few decades in Ningxia Province, China, are poorly understood. Here, we report the genetic diversities of 44 important genes related to grain yield, quality, adaptation and resistance in 121 Ningxia and 86 introduced wheat cultivars and advanced lines. RESULTS: The population structure indicated characteristics of genetic components of Ningxia wheat, including landraces of particular genetic resources, introduced varieties with rich genetic diversities and modern cultivars in different periods. Analysis of allele frequencies showed that the dwarfing alleles Rht-B1b at Rht-B1 and Rht-D1b at Rht-D1, 1BL/1RS translocation, Hap-1 at GW2-6B and Hap-H at Sus2-2B are very frequently present in modern Ningxia cultivars and in introduced varieties from other regions but absent in landraces. This indicates that the introduced wheat germplasm with numerous beneficial genes is vital for broadening the genetic diversity of Ningxia wheat varieties. Large population differentiation between modern cultivars and landraces has occurred in adaptation genes. Founder parents carry excellent allele combinations of important genes, with a higher number of favorable alleles than modern cultivars. Gene flow analysis showed that six founder parents have greatly contributed to breeding improvement in Ningxia Province, particularly Zhou 8425B, for yield-related genes. CONCLUSIONS: Varieties introduced from other regions with rich genetic diversity and landraces with well-adapted genetic resources have been applied to improve modern cultivars. Founder parents, particularly Zhou 8425B, for yield-related genes have contributed greatly to wheat breeding improvement in Ningxia Province. These findings will greatly benefit bread wheat breeding in Ningxia Province as well as other areas with similar ecological environments.

Evolutionary characteristics and phylogeny of cotton chloroplast tRNAs.

MAIN CONCLUSION: The novel structural variations were identified in cotton chloroplast tRNAs and gene loss events were more obvious than duplications in chloroplast tRNAs. Transfer RNAs (tRNA) have long been believed an evolutionary-conserved molecular family, which play the key roles in the process of protein biosynthesis in plant life activities. In this study, we detected the evolutionary characteristics and phylogeny of chloroplast tRNAs in cotton plants, an economic and fibered important taxon in the world. We firstly annotated the chloroplast tRNAs of 27 Gossypium species to analyze their genetic composition, structural characteristics and evolution. Compared with the traditional view of evolutionary conservation of tRNA, some novel tRNA structural variations were identified in cotton plants. I.g., tRNAVal-UAC and tRNAIle-GAU only contained one intron in the anti-condon loop region of tRNA secondary structure, respectively. In the variable region, some tRNAs contained a circle structure with a few nucleotides. Interestingly, the calculation result of free energy indicated that the variation of novel tRNAs contributed to the stability of tRNA structure. Phylogenetic analysis suggested that chloroplast tRNAs have evolved from multiple common ancestors, and the tRNAMet seemed to be an ancestral tRNA, which can be duplicated and diversified to produce other tRNAs. The chloroplast tRNAs contained a group I intron in cotton plants, and the evolutionary analysis of introns indicated that group I intron of chloroplast tRNA originated from cyanobacteria. Analysis of gene duplication and loss events showed that gene loss events were more obvious than duplications in Gossypium chloroplast tRNAs. Additionally, we found that the rate of transition was higher than the ones of transversion in cotton chloroplast tRNAs. This study provided new insights into the structural characteristics and evolution of chloroplast tRNAs in cotton plants.

Experimental Realization of Device-Independent Quantum Randomness Expansion.

Randomness expansion where one generates a longer sequence of random numbers from a short one is viable in quantum mechanics but not allowed classically. Device-independent quantum randomness expansion provides a randomness resource of the highest security level. Here, we report the first experimental realization of device-independent quantum randomness expansion secure against quantum side information established through quantum probability estimation. We generate 5.47×10^{8} quantum-proof random bits while consuming 4.39×10^{8} bits of entropy, expanding our store of randomness by 1.08×10^{8} bits at a latency of about 13.1 h, with a total soundness error 4.6×10^{-10}. Device-independent quantum randomness expansion not only enriches our understanding of randomness but also sets a solid base to bring quantum-certifiable random bits into realistic applications.

An RTM-GWAS procedure reveals the QTL alleles and candidate genes for three yield-related traits in upland cotton.

BACKGROUND: Cotton (Gossypium spp.) fiber yield is one of the key target traits, and improved fiber yield has always been thought of as an important objective in the breeding programs and production. Although some studies had been reported for the understanding of genetic bases for cotton yield-related traits, the detected quantitative trait loci (QTL) for the traits is still very limited. To uncover the whole-genome QTL controlling three yield-related traits in upland cotton (Gossypium hirsutum L.), phenotypic traits were investigated under four planting environments and 9244 single-nucleotide polymorphism linkage disequilibrium block (SNPLDB) markers were developed in an association panel consisting of 315 accessions. RESULTS: A total of 53, 70 and 68 significant SNPLDB loci associated with boll number (BN), boll weight (BW) and lint percentage (LP), were respectively detected through a restricted two-stage multi-locus multi-allele genome-wide association study (RTM-GWAS) procedure in multiple environments. The haplotype/allele effects of the significant SNPLDB loci were estimated and the QTL-allele matrices were organized for offering the abbreviated genetic composition of the population. Among the significant SNPLDB loci, six of them were simultaneously identified in two or more single planting environments and were thought of as the stable SNPLDB loci. Additionally, a total of 115 genes were annotated in the nearby regions of the six stable SNPLDB loci, and 16 common potential candidate genes controlling target traits of them were predicted by two RNA-seq data. One of 16 genes (GH_D06G2161) was mainly expressed in the early ovule-development stages, and the stable SNPLDB locus (LDB_19_62926589) was mapped in its promoter region. CONCLUSION: This study identified the QTL alleles and candidate genes that could provide important insights into the genetic basis of yield-related traits in upland cotton and might facilitate breeding cotton varieties with high yield.

AKR2A participates in the regulation of cotton fibre development by modulating biosynthesis of very-long-chain fatty acids.

The biosynthesis of very-long-chain fatty acids (VLCFAs) and their transport are required for fibre development. However, whether other regulatory factors are involved in this process is unknown. We report here that overexpression of an Arabidopsis gene ankyrin repeat-containing protein 2A (AKR2A) in cotton promotes fibre elongation. RNA-Seq analysis was employed to elucidate the mechanisms of AKR2A in regulating cotton fibre development. The VLCFA content and the ratio of VLCFAs to short-chain fatty acids increased in AKR2A transgenic lines. In addition, AKR2A promotes fibre elongation by regulating ethylene and synergizing with the accumulation of auxin and hydrogen peroxide. Analysis of RNA-Seq data indicates that AKR2A up-regulates transcript levels of genes involved in VLCFAs' biosynthesis, ethylene biosynthesis, auxin and hydrogen peroxide signalling, cell wall and cytoskeletal organization. Furthermore, AKR2A interacted with KCS1 in Arabidopsis both in vitro and in vivo. Moreover, the VLCFA content and the ratio of VLCFAs to short-chain fatty acids increased significantly in seeds of AKR2A-overexpressing lines and AKR2A/KCS1 co-overexpressing lines, while AKR2A mutants are the opposite trend. Our results uncover a novel cotton fibre growth mechanism by which the critical regulator AKR2A promotes fibre development via activating hormone signalling cascade by mediating VLCFA biosynthesis. This study provides a potential candidate gene for improving fibre yield and quality through genetic engineering.

Regulation of the Metal Center and Coordinating Anion of Mononuclear Ln(III) Complexes to Promote an Efficient Luminescence Response to Various Organic Solvents.

A series of mononuclear lanthanide complexes [Ln(L1)(NO3)3], (Ln = Dy(III), 1; Tb(III), 3; and Eu(III), 4; L1 = (N1E,N2E)-N1,N2-bis((1-methyl-1H-benzo[d]imidazol-2-yl)methylene)cyclohexane-1,2-diamine) is obtained by reacting N-methylbenzimidazole-2-carbaldehyde (L2) and 1,2-cyclohexanediamine (L3) with Ln(NO3)3·6H2O under solvothermal conditions. L1 ligand is produced via an in situ Schiff base reaction of two molecules of L2 and one molecule of L3. The metal center Ln(III) is in a N4O6 environment formed by L1 and NO3-. NaSCN is added on the basis of 1 synthesis. One SCN- replaces one of the three coordinated NO3- anions in the 1 structure, and the complex [Dy(L1)(NO3)2(SCN)]·CH3CN (2) is synthesized. The complex 1 shows excellent luminescence response to petroleum ether (PET), an organic solvent. To the best of our knowledge, this study is the first to use a complex for sensing responses to PET. When the metal center is changed, the obtained mononuclear complexes 3 and 4 show an excellent luminescence response to tetrahydrofuran (THF). Lastly, 2 obtained by changing the coordinating anion shows an excellent luminescence response to dichloromethane. Herein, for the first time, we regulate the metal center and coordinating anion of lanthanide complexes to adjust the recognition and response of these complexes to different organic solvents.

Gene transfer and nucleotide sequence evolution by Gossypium cytoplasmic genomes indicates novel evolutionary characteristics.

KEY MESSAGE: The DNA fragments transferred among cotton cytoplasmic genomes are highly differentiated. The wild D group cotton species have undergone much greater evolution compared with cultivated AD group. Cotton (Gossypium spp.) is one of the most economically important fiber crops worldwide. Gene transfer, nucleotide evolution, and the codon usage preferences in cytoplasmic genomes are important evolutionary characteristics of high plants. In this study, we analyzed the nucleotide sequence evolution, codon usage, and transfer of cytoplasmic DNA fragments in Gossypium chloroplast (cp) and mitochondrial (mt) genomes, including the A genome group, wild D group, and cultivated AD group of cotton species. Our analyses indicated that the differences in the length of transferred cytoplasmic DNA fragments were not significant in mitochondrial and chloroplast sequences. Analysis of the transfer of tRNAs found that trnQ and nine other tRNA genes were commonly transferred between two different cytoplasmic genomes. The Codon Adaptation Index values showed that Gossypium cp genomes prefer A/T-ending codons. Codon preference selection was higher in the D group than the other two groups. Nucleotide sequence evolution analysis showed that intergenic spacer sequences were more variable than coding regions and nonsynonymous mutations were clearly more common in cp genomes than mt genomes. Evolutionary analysis showed that the substitution rate was much higher in cp genomes than mt genomes. Interestingly, the D group cotton species have undergone much faster evolution compared with cultivated AD groups, possibly due to the selection and domestication of diverse cotton species. Our results demonstrate that gene transfer and differential nucleotide sequence evolution have occurred frequently in cotton cytoplasmic genomes.

Direct counterfactual communication via quantum Zeno effect.

Intuition from our everyday lives gives rise to the belief that information exchanged between remote parties is carried by physical particles. Surprisingly, in a recent theoretical study [Salih H, Li ZH, Al-Amri M, Zubairy MS (2013) Phys Rev Lett 110:170502], quantum mechanics was found to allow for communication, even without the actual transmission of physical particles. From the viewpoint of communication, this mystery stems from a (nonintuitive) fundamental concept in quantum mechanics-wave-particle duality. All particles can be described fully by wave functions. To determine whether light appears in a channel, one refers to the amplitude of its wave function. However, in counterfactual communication, information is carried by the phase part of the wave function. Using a single-photon source, we experimentally demonstrate the counterfactual communication and successfully transfer a monochrome bitmap from one location to another by using a nested version of the quantum Zeno effect.