Complete Characterization Research Articles

A class of Schwarz qubit maps with diagonal unitary and orthogonal symmetries

Abstract A class of unital qubit maps displaying diagonal unitary and orthogonal symmetries is analyzed. Such maps have already found a lot applications in quantum information theory. We provide a complete characterization of this class of maps showing intricate relation between positivity, operator Schwarz inequality, and complete positivity. Finally, it is shown how to generalize the entire picture beyond unital case (so called generalized Schwarz maps). Interestingly, the first example of Schwarz but not completely positive map found by Choi belongs to our class. As a case study we provide a full characterization of Pauli maps. Our analysis leads to generalization of seminal Fujiwara–Algoet conditions for Pauli quantum channels.

Sharing proofs with predicative theories through universe-polymorphic elaboration

As the development of formal proofs is a time-consuming task, it is important to devise ways of sharing the already written proofs to prevent wasting time redoing them. One of the challenges in this domain is to translate proofs written in proof assistants based on impredicative logics to proof assistants based on predicative logics, whenever impredicativity is not used in an essential way. In this paper we present a transformation for sharing proofs with a core predicative system supporting prenex universe polymorphism. It consists in trying to elaborate each term into a predicative universe-polymorphic term as general as possible. The use of universe polymorphism is justified by the fact that mapping each universe to a fixed one in the target theory is not sufficient in most cases. During the elaboration, we need to solve unification problems in the equational theory of universe levels. In order to do this, we give a complete characterization of when a single equation admits a most general unifier. This characterization is then employed in a partial algorithm which uses a constraint-postponement strategy for trying to solve unification problems. The proposed translation is of course partial, but in practice allows one to translate many proofs that do not use impredicativity in an essential way. Indeed, it was implemented in the tool Predicativize and then used to translate semi-automatically many non-trivial developments from Matita's library to Agda, including proofs of Bertrand's Postulate and Fermat's Little Theorem, which (as far as we know) were not available in Agda yet.

Physics-informed neural network for volumetric sound field reconstruction of speech signals

Recent developments in acoustic signal processing have seen the integration of deep learning methodologies, alongside the continued prominence of classical wave expansion-based approaches, particularly in sound field reconstruction. Physics-informed neural networks (PINNs) have emerged as a novel framework, bridging the gap between data-driven and model-based techniques for addressing physical phenomena governed by partial differential equations. This paper introduces a PINN-based approach for the recovery of arbitrary volumetric acoustic fields. The network incorporates the wave equation to impose a regularization on signal reconstruction in the time domain. This methodology enables the network to learn the physical law of sound propagation and allows for the complete characterization of the sound field based on a limited set of observations. The proposed method’s efficacy is validated through experiments involving speech signals in a real-world environment, considering varying numbers of available measurements. Moreover, a comparative analysis is undertaken against state-of-the-art frequency domain and time domain reconstruction methods from existing literature, highlighting the increased accuracy across the various measurement configurations.

Isolation of ovatoxin-a from Ostreopsis cf. ovata cultures. A key step for hazard characterization and risk management of ovatoxins

Ostreopsis cf. ovata, a benthic/epiphytic marine dinoflagellate, is currently spreading in tropical, sub-tropical and temperate areas, causing periodic Harmful Algal Blooms (HABs). It produces a wide array of palytoxin-like compounds named ovatoxins (OVTXs), with OVTX-a generally the most abundant congener. Despite numerous cases of human poisonings and environmental damage associated with the presence of OVTXs and O. cf. ovata proliferations, a complete characterization of the toxicity of this class of molecules cannot be performed until Reference Material (RM) for individual congeners is available. This, in turn, requires the availability of sufficient amounts of toxin at a high purity grade. To achieve this goal, herein an analytical re-evaluation of critical-steps of OVTX-a isolation from O. cf. ovata cell pellets is reported. The overall procedure consists of four steps, namely an extraction, a Medium Pressure Liquid Chromatography (MPLC) separation, and two preparative High Performance Liquid Chromatography (HPLC) steps. Particular attention was paid to the extraction step to evaluate the repeatability in OVTX-a yields. For subsequent steps, loading sample preparation and chromatographic conditions were refined. As a result, a significant increase in recovery yields (from 12.5 to 20 ± 3%) and in purity grade (from 51% to 94%) of the isolated OVTX-a was achieved in comparison to previous studies. The improved procedure can easily be applied to isolate sufficient quantities of a good candidate RM for OVTX-a.

Optimized terahertz generation in BNA organic crystals with chirped Ti:sapphire laser pulses.

We report on the efficient generation of intense terahertz radiation from the organic crystal N-benzyl-2-methyl-4-nitroaniline pumped by chirped Ti:sapphire femtosecond laser pulses. The THz energy and spectrum as a function of the pump fluence and duration of the chirped laser pulses are studied systematically. For the appropriate positively chirped pump pulses, a significant boost in the THz generation efficiency by a factor of around 2.5 is achieved, and the enhancement of high-frequency components (>1 THz) shortens the THz pulse duration. Via complete characterization of THz properties and transmitted laser spectra, this nonlinear behavior is attributed to the extended effective interaction length for phase matching as a result of the self-phase modulation of the intense pump laser pulses. Numerical calculations well reproduce the experimental observation. Our results demonstrate a robust, efficient, strong-field (up to several MV/cm) THz source using the common sub-10 mJ and sub-100 fs Ti:sapphire laser systems without optical parametric amplifiers.

Complete mitochondrial genome characterisation of Ratha longimana (H. Milne Edwards, 1834) from the western Atlantic Ocean, with a phylogeny of the Xanthidae (Decapoda: Brachyura)

Abstract The longhand rubble crab Ratha longimana inhabits coral reefs and rocky shores in the subtropical and tropical western Atlantic Ocean. This species was long considered to be the only chlorodielline species present in the area, but has since been transferred to the genus RathaLasley, Lai & Thoma, 2013 and is now thought to belong to an undescribed subfamily within Xanthidae MacLeay, 1838. Here we provide a complete mitochondrial assemblage and characterisation of this species. The assembled mitochondrial genome (hereafter mitogenome) of R. longimana is 15,819 bp in length and contains 13 protein coding genes (PCGs), 22 transfer RNA (tRNA) genes, and two ribosomal RNA (rRNA) genes. The 22 tRNA genes range from 62 to 69 bp in length. A mitochondrial gene order (MGO) analysis revealed a transposition of the tRNA genes Val (V) and 12S rRNA (rrnS) when compared to the ancestral brachyuran gene order, which is in line with earlier studies on xanthoid mitogenomes. Mitogenome data for xanthid crabs (as well as the superfamily Xanthoidea MacLeay, 1838) are currently scarce considering the species richness of the family, limiting the options for phylogenomic studies. This is partially remedied here by providing a new genomic resource for R. longimana.

Whole genome sequencing and genome characterization of Aichivirus isolated from Korean adults.

The whole-genome sequence (WGS) analysis of Aichivirus (AiV) identified in Korea was performed in this study. Using Sanger and Nanopore sequencing, the 8228-nucleotide-long genomic sequence of AiV (OQ121963) was determined and confirmed to belong to genotype A. The full-length genome of OQ121963 consisted of a 7296 nt open reading frame (ORF) that encodes a single polyprotein, and 5' UTR (676 nt) and 3' UTR (256 nt) at 5' and 3' ends, respectively. The ORF consisted of leader protein (L), structural protein P1 (VP0, VP1, and VP3), and nonstructural protein P2 (2A, 2B, and 2C) and P3 (3A, 3B, 3C, and 3D). The secondary structure analysis of the 5' UTR identified only stem-loop C (SL-C) and not SL-A and SL-B. The variable region of the AiV genome was analyzed by MegAlign Pro and reconfirmed by SimPlot analysis using 16 AiV whole genomes known to date. Among the entire regions, structural protein region P1 showed the lowest amino acid identity (96.07%) with reference sequence AB040749 (originated in Japan; genotype A), while the highest amino acid identity (98.26%) was confirmed in the 3D region among nonstructural protein region P2 and P3. Moreover, phylogenetic analysis of the WGS of OQ121963 showed the highest homology (96.96%) with JX564249 (originated in Taiwan; genotype A) and lowest homology (90.14%) with DQ028632 (originated in Brazil; genotype B). Therefore, the complete genome characterization of OQ121963 and phylogenetic analysis of the AiV conducted in this study provide useful information allowing to improve diagnostic tools and epidemiological studies of AiVs.

Astrometry and Precise Radial Velocities Yield a Complete Orbital Solution for the Nearby Eccentric Brown Dwarf LHS 1610 b

The LHS 1610 system consists of a nearby (d = 9.7 pc) M5 dwarf hosting a candidate brown dwarf companion in a 10.6 days, eccentric (e ∼ 0.37) orbit. We confirm this brown dwarf designation and estimate its mass ( 49.5−3.5+4.3 M Jup) and inclination (114.5° −10.0+7.4 ) by combining discovery radial velocities (RVs) from the Tillinghast Reflector Echelle Spectrograph and new RVs from the Habitable-zone Planet Finder with the available Gaia astrometric two-body solution. We highlight a discrepancy between the measurement of the eccentricity from the Gaia two-body solution (e = 0.52 ± 0.03) and the RV-only solution (e = 0.3702 ± 0.0003). We discuss possible reasons for this discrepancy, which can be further probed when the Gaia astrometric time series become available as part of Gaia Data Release 4. As a nearby mid-M star hosting a massive short-period companion with a well-characterized orbit, LHS 1610 b is a promising target to look for evidence of sub-Alfvénic interactions and/or auroral emission at optical and radio wavelengths. LHS 1610 has a flare rate (0.28 ± 0.07 flares per day) on the higher end for its rotation period (84 ± 8 days), similar to other mid-M dwarf systems such as Proxima Cen and YZ Ceti that have recent radio detections compatible with star–planet interactions. While available Transiting Exoplanet Survey Satellite photometry is insufficient to determine an orbital phase dependence of the flares, our complete orbital characterization of this system makes it attractive to probe star–companion interactions with additional photometric and radio observations.

A criterion for the holomorphy of the curvature of smooth planar webs and applications to dual webs of homogeneous foliations on PC2$\mathbb {P}^{2}_{\mathbb {C}}$

AbstractLet be an integer. For a holomorphic ‐web on a complex surface , smooth along an irreducible component of its discriminant , we establish an effective criterion for the holomorphy of the curvature of along , generalizing results on decomposable webs due to Marín, Pereira, and Pirio. As an application, we deduce a complete characterization for the holomorphy of the curvature of the Legendre transform (dual web) of a homogeneous foliation of degree on , generalizing some of our previous results. This then allows us to study the flatness of the ‐web in the particular case where the foliation is Galois. When the Galois group of is cyclic, we show that is flat if and only if is given, up to linear conjugation, by one of the two 1‐forms , . When the Galois group of is noncyclic, we obtain that is always flat.

Red blood cell distribution width as a surrogate biomarker of damage and disease activity in patients with systemic lupus erythematosus.

Red blood cell distribution width (RDW) is a measure of variability in mean corpuscular volume. Alterations in RDW can be observed in a variety of human disorders, including inflammatory, cardiovascular, and hepatic or renal diseases. Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that can affect virtually any organ in the body. In this work, our objective was to analyse how a complete characterisation of disease characteristics in a large series of patients with SLE is related to RDW values. 284 patients with SLE and 181 age- and sex-matched healthy controls were recruited. Complete blood count including RDW was assessed. Multivariable analysis was performed to analyse the relationship between RDW and SLE disease characteristics, including composite scores of disease activity and damage. After multivariable adjustment, RDW was higher in patients with SLE compared to controls (beta coefficient 0.8 [95% confidence interval: 0.3-1] %, p=0.003). Several disease characteristics, such as the presence of extractable nuclear antibodies and antiphospholipid syndrome, and the use of prednisone and azathioprine, were significantly associated with higher levels of RDW after adjustment for confounders. Of note, cumulative disease damage and disease activity scores were associated with higher RDW values after controlling for covariates. RDW may serve as a surrogate biomarker of accrual disease damage and activity in patients with SLE.

Projections of four corner Cantor set: Total self-similarity, spectrum and unique codings

Given ρ∈(0,1/4], the four corner Cantor set E⊂R2 is a self-similar set generated by the iterated function system {(ρx,ρy),(ρx,ρy+1−ρ),(ρx+1−ρ,ρy),(ρx+1−ρ,ρy+1−ρ)}. For θ∈[0,π) let Eθ be the orthogonal projection of E onto a line with an angle θ to the x-axis. In principle, Eθ is a self-similar set having overlaps. In this paper we give a complete characterization on which the projection Eθ is totally self-similar. We also study the spectrum of Eθ, which turns out that the spectrum achieves its maximum value if and only if Eθ is totally self-similar. Furthermore, when Eθ is totally self-similar, we calculate its Hausdorff dimension and study the subset Uθ which consists of all x∈Eθ having a unique coding. In particular, we show that dimHUθ=dimHEθ for Lebesgue almost every θ∈[0,π). Finally, for ρ=1/4 we prove that the possibility for Eθ to contain an interval is strictly smaller than that for Eθ to have an exact overlap.

Unraveling the Structure and Dynamics of Ac-PHF6-NH2 Tau Segment Oligomers.

The aggregation of the proteins tau and amyloid-β is a salient feature of Alzheimer's disease, the most common form of neurodegenerative disorders. Upon aggregation, proteins transition from their soluble, monomeric, and functional state into insoluble, fibrillar deposits through a complex process involving a variety of intermediate species of different morphologies, including monomers, toxic oligomers, and insoluble fibrils. To control and direct peptide aggregation, a complete characterization of all species present and an understanding of the molecular processes along the aggregation pathway are essential. However, this is extremely challenging due to the transient nature of oligomers and the complexity of the reaction networks. Therefore, we have employed a combined approach that allows us to probe the structure and kinetics of oligomeric species, following them over time as they form fibrillar structures. Targeting the tau protein peptide segment Ac-PHF6-NH2, which is crucial for the aggregation of the full protein, soft nano-electrospray ionization combined with ion mobility mass spectrometry has been employed to study the kinetics of heparin-induced intact oligomer formation. The oligomers are identified and characterized using high-resolution ion mobility mass spectrometry, demonstrating that the addition of heparin does not alter the structure of the oligomeric species. The kinetics of fibril formation is monitored through a Thioflavin T fluorescence assay. Global fitting of the kinetic data indicates that secondary nucleation plays a key role in the aggregation of the Ac-PHF6-NH2 tau segment, while the primary nucleation rate is greatly accelerated by heparin.

Geometry of transcendental singularities of complex analytic functions and vector fields

Abstract On Riemann surfaces M M , there exists a canonical correspondence between a possibly multivalued function Ψ X {\Psi }_{X} whose differential is single-valued (i.e. an additively automorphic singular complex analytic function) and a vector field X X . From the point of view of vector fields, the singularities that we consider are zeros, poles, isolated essential singularities, and accumulation points of the above. The theory of singularities of the inverse function Ψ X ‒ 1 {\Psi }_{X}^{‒1} is extended from meromorphic functions to additively automorphic singular complex analytic functions. The main contribution is a complete characterization of when a singularity of Ψ X − 1 {\Psi }_{X}^{-1} is algebraic, is logarithmic, or arises from a zero with non-zero residue of X X . Relationships between analytical properties of Ψ X {\Psi }_{X} , singularities of Ψ X − 1 {\Psi }_{X}^{-1} and singularities of X X are presented. Families and sporadic examples showing the geometrical richness of vector fields on the neighbourhoods of the singularities of Ψ X − 1 {\Psi }_{X}^{-1} are studied. As applications, we have; a description of the maximal univalence regions for complex trajectory solutions of a vector field X X , a geometric characterization of the incomplete real trajectories of a vector field X X , and a description of the singularities of the vector field associated with the Riemann ξ {\rm{\xi }} -function.

Multiparameter cascaded quantum interferometer

We theoretically propose a multiparameter cascaded quantum interferometer in which a two-input and two-output setup is obtained by concatenating 50:50 beam splitters with n independent and adjustable time delays. A general method for deriving the coincidence probability of such an interferometer is given based on the linear transformation of the matrix of beam splitters. As examples, we analyze the interference characteristics of one-, two-, and three-parameter cascaded quantum interferometers with different frequency correlations and input states. Some typical interferograms of such interferometers are provided to reveal richer and more complicated two-photon interference phenomena. This work offers a general theoretical framework for designing versatile quantum interferometers and provides a convenient method for deriving the coincidence probabilities involved. In principle, arbitrary two-input and two-output experimental setups can be designed with the framework. Potential applications can be found in the complete spectral characterization of two-photon states, multiparameter estimation, and quantum metrology.

Molecular properties, including chameleonicity, as essential tools for designing the next generation of oral beyond rule of five drugs

Background and Purpose. The classical drug discovery toolbox continually expands beyond traditional rule of five (Ro5)-compliant small molecules to include new chemical modalities for difficult-to-drug targets. The paper focuses on the molecular properties essential to drive oral bioavailability within the bRo5 framework. Experimental Approach. The first part outlines the concept and methodologies for characterizing bRo5 physicochemical properties, including considerations on chameleonicity; in particular, the paper sum­marizes the content of the last author’s talk presented during the IAPC-10 Meeting held in Belgrade in September 2023 (https://iapchem.org/index.php/iapc-10-home). The second part of the manuscript presents novel experimental and computational data on three proteolysis targeting chimeras (PROTACs) currently in clinical trials. Key Results. Molecular descriptors of ARV-110, ARV-471, and DT-2216 are reported and the main limitations of the applied experimental approaches are discussed. Moreover, a simple computational method shows how predicting the presence of chameleonic effects. Conclusion. A full complete physicochemical characterization of three degraders in clinical trial is reported to highlight the differences in physicochemical descriptors between PROTACs dosed orally and intravenously.

The extremals of the Kahn-Saks inequality

A classical result of Kahn and Saks states that given any partially ordered set with two distinguished elements, the number of linear extensions in which the ranks of the distinguished elements differ by k is log-concave as a function of k. The log-concave sequences that can arise in this manner prove to exhibit a much richer structure, however, than is evident from log-concavity alone. The main result of this paper is a complete characterization of the extremals of the Kahn-Saks inequality: we obtain a detailed combinatorial understanding of where and what kind of geometric progressions can appear in these log-concave sequences. This settles a partial conjecture of Chan-Pak-Panova, while the analysis uncovers new extremals that were not previously conjectured. The proof relies on a much more general geometric mechanism—a hard Lefschetz theorem for nef classes that was obtained in the setting of convex polytopes by Shenfeld and Van Handel—which forms a model for the investigation of such structures in other combinatorial problems.

Synthesis and Characterization of Transition Metal Complexes Supported by Phosphorus Ligands Obtained Using Hydrophosphination of Cyclic Internal Alkenes.

The design and study of rich, bulky phosphorus ligands is a key area of research for homogeneous catalysis. Here, we describe an original strategy using a hydrophosphination reaction to produce phosphines of interest for coordination chemistry and homogenous catalysis. In particular, the phosphine obtained by reacting diphenylphosphine with acenaphthylene (ligand 2) gives a ligand that adopts an unusual spatial geometry. The coordination chemistry of the ligand has been investigated with Au(I), Ag(I), Cu(I), and Pd(II), for which a complete characterization could be made, particularly in X-ray diffraction studies. The reactivity of some of these complexes has been demonstrated, particularly in Pd-catalyzed cross-coupling reactions and Au-catalyzed hydroaminations and in the hydration of alkynes.

Optimizing Distributions for Associated Entropic Vectors via Generative Convolutional Neural Networks.

The complete characterization of the almost-entropic region yields rate regions for network coding problems. However, this characterization is difficult and open. In this paper, we propose a novel algorithm to determine whether an arbitrary vector in the entropy space is entropic or not, by parameterizing and generating probability mass functions by neural networks. Given a target vector, the algorithm minimizes the normalized distance between the target vector and the generated entropic vector by training the neural network. The algorithm reveals the entropic nature of the target vector, and obtains the underlying distribution, accordingly. The proposed algorithm was further implemented with convolutional neural networks, which naturally fit the structure of joint probability mass functions, and accelerate the algorithm with GPUs. Empirical results demonstrate improved normalized distances and convergence performances compared with prior works. We also conducted optimizations of the Ingleton score and Ingleton violation index, where a new lower bound of the Ingleton violation index was obtained. An inner bound of the almost-entropic region with four random variables was constructed with the proposed method, presenting the current best inner bound measured by the volume ratio. The potential of a computer-aided approach to construct achievable schemes for network coding problems using the proposed method is discussed.

Bridging pyrimidine hemicurcumin and Cisplatin: Synthesis, coordination chemistry, and in vitro activity assessment of a novel Pt(II) complex

In the upcoming decades, the incidence and mortality rates of cancer are expected to rise globally, with colorectal and prostate cancers among the most prevalent types. Despite advancements in molecular targeted therapy, platinum-based chemotherapies remain the cornerstone of treatment, especially for colorectal and prostate cancer, with oxaliplatin and cisplatin being extremely effective due to their DNA-targeting capabilities. In our pursuit of new platinum-based chemotherapeutics that are potentially less toxic and more effective, we have explored the combination of the Pt-binding groups of the diaminocyclohexane ring used in oxaliplatin, with the stable amino-pyrimidine hemicurcumin moiety. This new derivative exhibit improved stability in physiological conditions and increased solubility in aqueous media, demonstrating promising effects on cell proliferation of both colorectal and prostate cells. We report herein the complete synthesis and chemical characterization in solution of the new derivative [(1R,2R)-N1-(3-(4-((E)-2-(2-Amino-6-methylpyrimidin-4-yl)vinyl)-2-methoxyphenoxy) propyl) cyclohexane-1,2-diamine] (MPYD). Our analysis includes an examination of its acid-base equilibria, speciation and stability in physiological conditions. The synthesis and in situ formation of Pt(II) complexes were investigated by nuclear magnetic resonance spectroscopy, while density functional theory calculations were employed to elucidate the chemical structure in solution. Results on the biological activity were obtained through cell viability assays on different colorectal and prostate cell lines (HCT116, HT29, PC3 and LNCaP).

The support of mixed area measures involving a new class of convex bodies

Mixed volumes in n-dimensional Euclidean space are functionals of n-tuples of convex bodies K,L,C1,…,Cn−2. The Alexandrov–Fenchel inequalities are fundamental inequalities between mixed volumes of convex bodies. As very special cases they cover or imply many important inequalities between basic geometric functionals. A complete characterization of the equality cases in the Alexandrov–Fenchel inequality remains a challenging open problem. Major recent progress was made by Yair Shenfeld and Ramon van Handel [13,14], in particular they resolved the problem in the cases where C1,…,Cn−2 are polytopes, zonoids or smooth bodies (under some dimensional restriction). In [6] we introduced the class of polyoids, which are defined as limits of finite Minkowski sums of polytopes having a bounded number vertices. Polyoids encompass polytopes, zonoids and triangle bodies, and they can be characterized by means of generating measures. Based on this characterization and Shenfeld and van Handel's contribution (and under a dimensional restriction), we extended their result to polyoids (or smooth bodies). Our previous result was stated in terms of the support of the mixed area measure associated with the unit ball Bn and C1,…,Cn−2. This characterization result is completed in the present work which more generally provides a geometric description of the support of the mixed area measure of an arbitrary (n−1)-tuple of polyoids (or smooth bodies). The result thus (partially) confirms a long-standing conjecture by Rolf Schneider in the case of polyoids, and hence in particular it covers the case of zonoids and triangle bodies.