Unconstrained Analysis Research Articles

Simulating Non-Adiabatic Dynamics of Photoexcited Phenyl Azide: Investigating Electronic and Structural Relaxation en Route to the Formation of Phenyl Nitrene.

Excited state molecular dynamics simulations of the photoexcited phenyl azide have been performed. The semi-classical surface hopping approximation has enabled an unconstrained analysis of the electronic and nuclear degrees of freedom which contribute to the molecular dissociation of phenyl azide into phenyl nitrene and molecular nitrogen. The significance of the second singlet excited state in leading the photodissociation has been established through electronic structure calculations, based on multi-configurational schemes, and state population dynamics. The investigations on the structural dynamics have revealed the N-N bond separation to be accompanied by synchronous changes in the azide N-N-N bond angle. The 100 fs simulation results in a nitrene fragment that is electronically excited in the singlet manifold.

Signal and Image Reconstruction with Tight Frames via Unconstrained [formula omitted]-Analysis Minimizations

In the paper, we introduce an unconstrained analysis model based on the ℓ1−αℓ2(0<α≤1) minimization for the signal and image reconstruction. We develop some new technology lemmas for tight frame, and the recovery guarantees based on the restricted isometry property adapted to frames. The effective algorithm is established for the proposed nonconvex analysis model. We illustrate the performance of the proposed model and algorithm for the signal and compressed sensing MRI reconstruction via extensive numerical experiments. And their performance is better than that of the existing methods.

Performance analysis for unconstrained analysis based approaches* *The work was supported by NSFC (Nos.11901037, 11871109, 61932010, 61932011, 11771162, 12001067), CAEP Foundation (Grant No. CX20200027).

Efficient recovery of sparse signals from underdetermined linear systems has received extensive attentions in recent decade. This paper considers the stable recovery of a signal x , which is not k-sparse itself but is k-sparse in terms of a Parseval frame D , from the observations y = Ax + e via three unconstrained minimization approaches. We show that if the sensing matrix A satisfies the restricted isometry property adapted to D with for any t > 1, then these three approaches can stably recover x . As a consequence, when t = 2 and 3, our result significantly improves existing best sufficient conditions. Furthermore, we theoretically characterize the recovery errors of these methods.

Fully Automated Unconstrained Analysis of High-Resolution Mass Spectrometry Data with Machine Learning.

Mass spectrometry (MS) is a convenient, highly sensitive, and reliable method for the analysis of complex mixtures, which is vital for materials science, life sciences fields such as metabolomics and proteomics, and mechanistic research in chemistry. Although it is one of the most powerful methods for individual compound detection, complete signal assignment in complex mixtures is still a great challenge. The unconstrained formula-generating algorithm, covering the entire spectra and revealing components, is a "dream tool" for researchers. We present the framework for efficient MS data interpretation, describing a novel approach for detailed analysis based on deisotoping performed by gradient-boosted decision trees and a neural network that generates molecular formulas from the fine isotopic structure, approaching the long-standing inverse spectral problem. The methods were successfully tested on three examples: fragment ion analysis in protein sequencing for proteomics, analysis of the natural samples for life sciences, and study of the cross-coupling catalytic system for chemistry.

Testing the monophyly of Chaetarthriinae (Coleoptera, Hydrophilidae) and the phylogenetic position of Guyanobius with larval characters

The subfamily Chaetarthriinae includes morphologically distinct larvae that are adapted to a diversity of environments. Based on larval characters, cladistic analyses (maximum parsimony (MP) and Bayesian inference (BI) with homoplasy as a partitioning scheme) were performed to test the monophyly of the subfamily and the relationships of the two tribes included in it: Chaetarthriini and Anacaenini. The chaetotaxy of a third instar larva Guyanobius adocetus is described and illustrated in detail, including morphometric characters. This larva is compared to those of the known larvae of the tribe Chaetarthriini belonging to the genus Chaetarthria, and Pseudorygmodus, Crenitis, and Crenitulus from Anacaenini. None of the unconstrained analyses recover Chaetarthriinae as monophyletic. Chaetarthria diverges in an early branch, probably due to a series of unique morphological modifications associated with a riparian lifestyle whereas Guyanobius appears closely related to Anacaenini. Two alternative positions of Guyanobius are revealed: (1) as sister of all Anacaenini (unconstrained MP) or (2) nested within Anacaenini as sister of Crenitis + Crenitulus (constrained MP and unconstrained BI). The genera Paracymus and Tormus (tribe Laccobiini) diverge as two successive branches subordinate to Chaetarthriinae (excluding Chaetarthria) in the unconstrained MP analysis. However, the support is rather weak, and the position of Paracymus and Tormus is an artifact produced by some homoplastic characters. In this regard, homoplasy partitioning resulted a useful technique to solve some artifacts generated by convergent morphologies.

Machine Componential Analysis of Kinship Vocabularies: An Example

The paper introduces a computer program to handle the task of componential analysis of kinship terms. Given the kin terms of a language with their attendant kin types, the program discovers all componential models, including the "simplest" ones (using the minimum number of dimensions and components in kin term definitions). As an illustrative example of the application of the program we use the kinship vocabulary of Catalan, a previously unanalyzed language. A completely unconstrained analysis of Catalan leads to an intolerably large number of alternative models but our simplicity restriction pertaining to choosing the minimum number of dimensions leads to a unique model. The generated componential model of Catalan uses four dimensions of contrast, viz. "sex", "generation", "distance" and "affinity", and coincides with that of Spanish. However, it is different from those of other Indo-European languages that also use for demarcation this very set of dimensions.

Toward Privacy Preservation Using Clustering Based Anonymization: Recent Advances and Future Research Outlook

With the continuous increase in avenues of personal data generation, privacy protection has become a hot research topic resulting in various proposed mechanisms to address this social issue. The main technical solutions for guaranteeing a user’s privacy are encryption, pseudonymization, anonymization, differential privacy (DP), and obfuscation. Despite the success of other solutions, anonymization has been widely used in commercial settings for privacy preservation because of its algorithmic simplicity and low computing overhead. It facilitates unconstrained analysis of published data that DP and the other latest techniques cannot offer, and it is a mainstream solution for responsible data science. In this paper, we present a comprehensive analysis of clustering-based anonymization mechanisms (CAMs) that have been recently proposed to preserve both privacy and utility in data publishing. We systematically categorize the existing CAMs based on heterogeneous types of data (tables, graphs, matrixes, etc.), and we present an up-to-date, extensive review of existing CAMs and the metrics used for their evaluation. We discuss the superiority and effectiveness of CAMs over traditional anonymization mechanisms. We highlight the significance of CAMs in different computing paradigms, such as social networks, the internet of things, cloud computing, AI, and location-based systems with regard to privacy preservation. Furthermore, we present various proposed representative CAMs that compromise individual privacy, rather than safeguarding it. Finally, we discuss the technical challenges of applying CAMs, and we suggest promising opportunities for future research. To the best of our knowledge, this is the first work to systematically cover current CAMs involving different data types and computing paradigms.

Object Detection in Drone Imagery via Sample Balance Strategies and Local Feature Enhancement

With the advent of drones, new potential applications have emerged for the unconstrained analysis of images and videos from aerial view cameras. Despite the tremendous success of the generic object detection methods developed using ground-based photos, a considerable performance drop is observed when these same methods are directly applied to images captured by Unmanned Aerial Vehicles (UAVs). Usually, most of the work goes into improving the performance of the detector in aspects such as design loss, training sample selection, feature enhancement, and so forth. This paper proposes a detection framework based on an anchor-free detector with several modules, including a sample balance strategies module and super-resolved generated feature module, to improve performance. We proposed the sample balance strategies module to optimize the imbalance among training samples, especially the imbalance between positive and negative, and easy and hard samples. Due to the high frequencies and noisy representation of the small objects in images captured by drones, the detection task is extraordinarily challenging. However, when compared with other algorithms of this kind, our method achieves better results. We also propose a super-resolved generated GAN (Generative Adversarial Network) module with center-ness weights to effectively enhance the local feature map. Finally, we demonstrate our method’s effectiveness with the proposed modules by carrying out a state-of-the-art performance on Visdrone2020 benchmarks.

Unexpected new lizard from the Late Cretaceous of southern South America sheds light on Gondwanan squamate diversity

The record of Cretaceous terrestrial lizards (Squamata) in South America is patchy, with seven species described from north-eastern and south-eastern Brazil, and few isolated records of iguanians and scincomorphans from the Argentinian Patagonia. Herein we describe a new genus and species of Cretaceous lizard, Paleochelco occultato gen. et sp. nov., based on a partial skull (MACN-Pv-N 120) discovered about three decades ago that was unnoticed in the Coleccion Paleovertebrados of the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”. It comes from rocks of the Upper Cretaceous Bajo de la Carpa Formation (Neuquen Group) exposed at the Campus of the Universidad Nacional del Comahue, north of Neuquen City (Neuquen Province). The new taxon was included into a broad phylogenetic dataset of squamates and it was recovered around the base of Polyglyphanodontia in a constrained analysis using a total-evidence backbone. By contrast, the same, but topologically unconstrained analysis found Paleochelco occultato also around the base of Polyglyphanodontia but alternatively as the sister taxon to Polyglyphanodontia + Scleroglossa or as one of the sister taxa to the Mosasauria + Scleroglossa clade. The new finding, as well as other records from Argentina and Brazil, highlights a complex, still unrecovered, evolutionary history for lizards in the Mesozoic of South America.

Competing priorities: a qualitative study of how women make and enact decisions about weight gain in pregnancy

BackgroundDespite ample clinical evidence that gaining excess weight in pregnancy results in negative health outcomes for women and infants, more than half of women in Western industrialized nations gain in excess of national guidelines. The influence of socio-demographic factors and weight gain is well-established but not causal; the influence of psychological factors may explain some of this variation.MethodsThis is the qualitative portion of an explanatory sequential mixed-methods study designed to identify predictive psychological factors of excess gestational weight gain (QUAN) and then explain the relevance of those factors (qual). For this portion of the study, we used a qualitative descriptive approach to elicit 39 pregnant women’s perspectives of gestational weight gain, specifically inquiring about factors determined as relevant to excess gestational weight gain by our previous predictive study. Women were interviewed in the latter half of their third trimester. Data were analyzed using a combination of unconstrained deductive content analysis to describe the findings relevant to the predictive factors and a staged inductive content analytic approach to examine the data without a focus on the predictive factors.ResultsVery few participants consistently made deliberate choices relevant to weight gain; most behaviour relevant to weight gain happened with in-the-moment decisions. These in-the-moment decisions were influenced by priorities, hunger, a consideration of the consequence of the decision, and accommodation of pregnancy-related discomfort. They were informed by the foundational information a woman had available to her, including previous experience and interactions with health care providers. The foundational information women used to make these decisions was often incomplete. While women were aware of the guidelines related to gestational weight gain, they consistently mis-applied them due to incorrect understanding of their own BMI. Only one woman was aware that weight gain was linked to maternal and infant health outcomes.ConclusionsThere is an important role for prenatal providers to provide the foundational information to positively influence in-the-moment decisions. Understanding how weight gain guidelines apply to one’s own pre-pregnancy BMI and comprehending the well-established link between gestational weight gain and health outcomes may help women prioritize healthy weight gain amongst many competing factors.

The phylogeny of the Diploporita: a polyphyletic assemblage of blastozoan echinoderms

AbstractThe phylogenetic relationships of Paleozoic blastozoan echinoderms are poorly understood and many of the traditionally ascribed groups are likely polyphyletic. Diploporitans, those blastozoans with double pore (diplopore) respiratory structures, have never been placed within a rigorous phylogenetic framework, and their highly variable morphologies suggest that they do not represent a natural clade. A maximum parsimony phylogenetic analysis, spanning a wide range of diploporitan and related taxa, indicates that diplopore-bearing blastozoans are a polyphyletic grouping and, consequently, that diplopore respiratory structures have evolved more than once within the echinoderms. Constraint analyses indicate that a single diplopore-bearing clade bearing the traditionally defined Glyptosphaeritida, Sphaeronitida, Asteroblastida is less parsimonious than multiple diplopore-bearing clades inferred by the unconstrained analysis.

An impressive skeleton of the giant top predator Prestosuchus chiniquensis (Pseudosuchia: Loricata) from the Triassic of Southern Brazil, with phylogenetic remarks

ABSTRACT In the present contribution, we aim to present the osteology of ‘ULBRA-PVT-281’, which comprises the best-preserved skeleton of Prestosuchus chiniquensis ever found. ULBRA-PVT-281 combines the morphology of two classic specimens referred to P. chiniquensis, UFRGS-PV-0156-T and UFRGSPV- 0152-T, reunited in a single operational taxonomic unit (OTU) in previous phylogenetic studies. Therefore, the new specimen reinforces the combination of both specimens. We performed a phylogenetic analysis, combining the information of these three specimens plus braincase data from a fourth specimen, UFRGS-PV-0629-T, into a new P. chiniquensis terminal taxon. Moreover, our analysis also included some new taxa potentially related to P. chiniquensis. As a result, we found a topology slightly distinct from previous studies, where Ticinosuchus ferox is the basalmost member of Loricata, which also includes the new combined P. chiniquensis. Our results place P. chiniquensis, Luperasuchus fractus, and Saurosuchus galilei distributed in a pectinate paraphyletic pattern towards Crocodylomorpha. On the other hand, a constrained analysis forcing the monophyly of these taxa demands just a single extra step. Therefore, both scenarios are plausible and agree with the placement of P. chiniquensis within Loricata, whereas T. ferox nests in Loricata only in the unconstrained analysis.

Atom probe tomography analysis of the reference zircon gj-1: An interlaboratory study

In recent years, atom probe tomography (APT) has been increasingly used to study minerals, and in particular the mineral zircon. Zircon (ZrSiO4) is ideally suited for geochronology by utilising the U-Th-Pb isotope systems, and trace element compositions are also widely used to constrain petrogenetic processes. However, while standard geoanalytical techniques provide information at micrometer scale lengths, the unique combination of chemical/isotopic sensitivity and spatial resolution of APT allows compositional and textural measurements at the nanoscale. This interlaboratory study aims to define the reproducibility of APT data across research facilities and assess the role of different aspects of the atom probe workflow on reproducibility. This is essential to allow correct evaluation of APT results and full utilization of this emerging technique within the geoscience community. In this study, nine samples from the same homogeneous, GJ-1/87 zircon reference grain were sent to nine APT institutes in Germany, the UK, USA, Canada and Australia. After preparing the sample out of a selectioned slab, each institute conducted three different rounds of APT analyses: using (i) unconstrained analysis parameters, (ii) pre-defined analysis parameters, and (iii) interpreting and quantifying a provided dataset. Data such as the measured elemental composition, acquisition parameters, or mass spectrum peak identifications, were recorded and analyzed. We observe a significant variation in the measured composition across this interlaboratory study as well as the number of trace elements identified. These differences are thought to directly result from the user's choice of atom probe data analysis parameters. The type of instrument does not seem to be a critical factor. Consequently, comparison of absolute trace element concentrations on zircon using APT between laboratories is only valid if the same workflow has been ensured.

Statistical Evaluation of Monophyly in the ‘Broad-Nosed Weevils’ through Molecular Phylogenetic Analysis Combining Mitochondrial Genome and Single-Locus Sequences (Curculionidae: Entiminae, Cyclominae, and Hyperinae)

Establishing well-supported monophyletic groups is a key requirement for producing a natural classification that reflects evolutionary descent. In a phylogenetic framework this is best achieved through dense taxon sampling and the analysis of a robust character dataset, combined with statistical testing of topological hypotheses. This study assesses the monophyly of tribes and subfamilies within the diverse ‘broad-nosed weevils’ (Curculionidae: Entiminae, Cyclominae and Hyperinae) through analysis of single-locus sequence data for mitochondrial cox1 and rrnL genes, in combination with a ‘backbone’ of complete and near-complete mitochondrial genome sequences. Maximum likelihood phylogenetic analyses incorporating topological constraints for various higher-taxa were statistically tested using the AU, SH, and KH tests, which indicated that three tribes within Entiminae, as presently classified, are not monophyletic. Moderate and high bootstrap support was also consistent with two entimine tribes (Peritelini and Cylydrorhinini) being each recovered as monophyletic in an unconstrained analysis. Furthermore, one genus of cyclomine weevils (Aphela) is recovered outside the clade of ‘broad-nosed weevils’, although its taxonomic placement remains uncertain. It is apparent that the present approach may be hampered by limited taxon sampling in the ‘backbone’ dataset, rendering it difficult for divergent taxa to robustly match to their closest lineages. However, with improved taxon sampling of the mitogenome tree, the general approach can be a useful taxonomic tool for weevils.

The Genus Woronichinia (Cyanobacteria) in Natural Lakes of Drawa National Park (Poland)

Abstract Woronichinia Elenkin is a cyanobacteria genus characteristic of lentic ecosystems. The type species, W. naegeliana (Unger) Elenkin, often blooms in the plankton of eutrophic reservoirs but this genus also contains species sensitive to high nutrient concentrations. The study analyzed the diversity and biomass of Woronichinia in lakes in a national park, isolated from the direct impact of human activity. The lakes were in various trophic states resulting from gradual and natural changes of trophy. Trophy was assessed with the use of the trophic diatom index, according to the classification we proposed for natural lakes. The relationship between the biomass and the trophic state of lakes was investigated with the use of multivariate unconstrained analysis with supplementary variables. Five species of Woronichinia were identified in all trophic types of lakes except for two oligotrophic ones: W. compacta (Lemmerm.) Komárek &amp; Hindák, W. delicatula (Skuja) Komárek &amp; Hindák, W. karelica Komárek &amp; Komárk.-Legn., W. obtusa Joosten and W. naegeliana (Unger) Elenkin. The occurrence and biomass of the species were related to the trophic state of the lakes. The absence of Woronichinia in two oligotrophic lakes could be due to the high concentration of humic compounds in the sediments. The low nitrogen-to-phosphorus ratio characteristic of the oligo-mesotrophic lakes resulted in increased species diversity. The lakes’ isolation from human activity fostered the development of rare and sensitive species such as W. delicatula and W. karelica.

Optical angle‐of‐arrival (AoA) sensor for the motion analysis of knee joints

The most widely used clinical technique for estimating bone movements in knee joints with acceptable accuracy utilises implantation of heavy metallic beads into the bones. These small metallic objects become visible as highly contrasting features in captured radiographs, thus facilitating post kinematic assessment of bones in human joints with pinpoint accuracy. Although, this approach provides necessary precision for clinical diagnosis, pre- and post-surgery planning for restoring joint function and locomotion, however, this approach also incurs high degree of invasiveness. In this study, a novel optical sensor is proposed for use in non-invasive motion measurement of knee joints in three-dimensional (3D) space. The approach is based on 3D angle-of-arrival (AoA) estimation using image processing procedures on the two-dimensional images of sensor's aperture shadows. The novelty of the sensor in terms of design, operation and its potential applications for a wide range of possibilities including precise AoA estimation for unconstrained 3D motion analysis of knee joints is described. Finally, error analysis of the sensor's AoA measurement uncertainty is provided for different incident angles of optical beams, which demonstrates the potential of the sensor not only for high-precision motion analysis of human joints; however, for other motion and position-aware systems.

Machine componential analysis of Bulgarian kinship terminology and more on the problem of multiple solutions

Machine componential analysis of Bulgarian kinship terminology and more on the problem of multiple solutionsThe Bulgarian kin terms of reference and address are subjected to componential analysis, using the sophisticated computer program KINSHIP. It is shown that an unconstrained and separate analysis of the two sets of terms yields an astronomical number of alternative componential models for each, threatening to compromise the componential method as a whole. However, after combining the set of reference and the set of address terms into a unitary kin term domain and applying the program to this new enlarged data set, further employing appropriate simplicity criteria on overall features (=dimensions) and components of kin term definitions, yields a unique componential model. This result is evaluated in the context of a famous debate on the problems of multiple solutions of kinship systems. It is concluded that componential analysis properly used is an indispensable tool for revealing the structuring of semantic domains.

Compact representation for large-scale unconstrained video analysis

Recently, newly invented features (e.g. Fisher vector, VLAD) have achieved state-of-the-art performance in large-scale video analysis systems that aims to understand the contents in videos, such as concept recognition and event detection. However, these features are in high-dimensional representations, which remarkably increases computation costs and correspondingly deteriorates the performance of subsequent learning tasks. Notably, the situation becomes even worse when dealing with large-scale video data where the number of class labels are limited. To address this problem, we propose a novel algorithm to compactly represent huge amounts of unconstrained video data. Specifically, redundant feature dimensions are removed by using our proposed feature selection algorithm. Considering unlabeled videos that are easy to obtain on the web, we apply this feature selection algorithm in a semi-supervised framework coping with a shortage of class information. Different from most of the existing semi-supervised feature selection algorithms, our proposed algorithm does not rely on manifold approximation, i.e. graph Laplacian, which is quite expensive for a large number of data. Thus, it is possible to apply the proposed algorithm to a real large-scale video analysis system. Besides, due to the difficulty of solving the non-smooth objective function, we develop an efficient iterative approach to seeking the global optimum. Extensive experiments are conducted on several real-world video datasets, including KTH, CCV, and HMDB. The experimental results have demonstrated the effectiveness of the proposed algorithm.

Twenty-first century advances in knowledge of the biology of moa (Aves: Dinornithiformes): a new morphological analysis and moa diagnoses revised

The iconic moa (Aves: Dinornithiformes) from New Zealand continue to attract much scientific scrutiny, as they have done since their discovery in the 1840s. Here, we review moa research since 2001 that advances our knowledge of the biology of these families; in particular, their breeding, diet and phylogenetic relationships. Then we perform a phylogenetic analysis based on morphological characters using a broader range of taxa and many more characters than hitherto used in moa analyses. Finally, we provide revised diagnoses of all moa taxa to reflect current knowledge. In this last decade, molecular analyses have been at the forefront of much of this research. Indeed, moa have become model subjects for advances in ancient DNA technology on account of their preservation and young geological age, and the fact that several of the foremost proponents of ancient DNA research are New Zealanders. Much of this research has been about extending the capacity of ancient DNA technology as much as about answering biological questions, but the resultant insights with regard to the latter have been profound for moa. Complete mitochondrial genomes for three species of moa have been published and extensive datasets of a number of mitochondrial genes are now available for all species over their entire geographic range. Analyses of nuclear DNA is limited to a sex specific gene and some preliminary microsatellite identifications, but it seems likely that improved technology will allow greater use of this resource in the near future. Phylogenetic analyses of mitochondrial molecular data have precipitated several changes to moa taxonomy and nine species are now recognised. The significance of deep phylogenetic structure among populations in some taxa continues to attract debate and likely will require nuclear data and a more profound understanding of natural variation in extant species to resolve. Significantly, molecular data have enabled new insights into diet, with direct identification of species responsible for coprolites, and by its new-found propensity to identify eggshell, foreshadows further advances in understanding their breeding biology and distribution. Our phylogenetic analysis, based on 179 characters scored for 23 ingroup palaeognath taxa and three galloanseres as outgroups, resulted in several strongly supported relationships. Firstly, the Eocene palaeognath Lithornis was either sister to remaining palaeognaths or had a weak affinity towards tinamous. All ratites formed a monophyletic clade exclusive of tinamous. Moa were monophyletic and sister to aepyornithids in the unconstrained analysis. Attempts to constrain moa as sister to tinamous to reflect molecular-based conclusions resulted in moa as sister to all ratites in a clade that was unresolved with respect to tinamous and Lithornis. This relatively basal position of moa was not a significantly worse reflection of the data compared to their more crownward location in the initial analyses. The casuariids were sister to Struthio and the rheas. In our revised diagnoses for Dinornithiformes and all its constituent taxa, we give updated information on the type specimens based on recent research by the authors. We accept three families, six genera and nine species, and make the new combinations of Euryapteryx curtus curtus (Owen) and E. curtus gravis (Owen). Complete or near complete exemplars of the skull of all moa taxa, most not illustrated before, are shown in dorsal, lateral and ventral views.

Is Remusatia (Araceae) Monophyletic? Evidence from Three Plastid Regions

The genus Remusatia (Araceae) includes four species distributed in the tropical and subtropical Old World. The phylogeny of Remusatia was constructed using parsimony and Bayesian analyses of sequence data from three plastid regions (the rbcL gene, the trnL-trnF intergenic spacer, and the rps16 intron). Phylogenetic analyses of the concatenated plastid data suggested that the monophyly of Remusatia was not supported because R. hookeriana did not form a clade with the other three species R. vivipara, R. yunnanensis, and R. pumila. Nevertheless, the topology of the analysis constraining Remusatia to monophyly was congruent with the topology of the unconstrained analysis. The results confirmed the inclusion of the previously separate genus Gonatanthus within Remusatia and disagreed with the current infrageneric classification of the genus.