Dynamic Structural Role Node Embedding for User Modeling in Evolving Networks

Complex user behavior, especially in settings such as social media, can be organized as time-evolving networks. Through network embedding, we can extract general-purpose vector representations of these dynamic networks which allow us to analyze them without extensive feature engineering. Prior work has shown how to generate network embeddings while preserving the structural role proximity of nodes. These methods, however, cannot capture the temporal evolution of the structural identity of the nodes in dynamic networks. Other works, on the other hand, have focused on learning microscopic dynamic embeddings. Though these methods can learn node representations over dynamic networks, these representations capture the local context of nodes and do not learn the structural roles of nodes. In this article, we propose a novel method for learning structural node embeddings in discrete-time dynamic networks. Our method, called HR2vec , tracks historical topology information in dynamic networks to learn dynamic structural role embeddings. Through experiments on synthetic and real-world temporal datasets, we show that our method outperforms other well-known methods in tasks where structural equivalence and historical information both play important roles. HR2vec can be used to model dynamic user behavior in any networked setting where users can be represented as nodes. Additionally, we propose a novel method (called network fingerprinting) that uses HR2vec embeddings for modeling whole (or partial) time-evolving networks. We showcase our network fingerprinting method on synthetic and real-world networks. Specifically, we demonstrate how our method can be used for detecting foreign-backed information operations on Twitter.

Characterization of a Novel L-Asparaginase from Mycobacterium gordonae with Acrylamide Mitigation Potential

L-asparaginase (E.C.3.5.1.1) is a well-known agent that prevents the formation of acrylamide both in the food industry and against childhood acute lymphoblastic leukemia in clinical settings. The disadvantages of L-asparaginase, which restrict its industrial application, include its narrow range of pH stability and low thermostability. In this study, a novel L-asparaginase from Mycobacterium gordonae (GmASNase) was cloned and expressed in Escherichia coli BL21 (DE3). GmASNase was found to be a tetramer with a monomeric size of 32 kDa, sharing only 32% structural identity with Helicobacter pylori L-asparaginases in the Protein Data Bank database. The purified GmASNase had the highest specific activity of 486.65 IU mg−1 at pH 9.0 and 50 °C. In addition, GmASNase possessed superior properties in terms of stability at a wide pH range of 5.0–11.0 and activity at temperatures below 40 °C. Moreover, GmASNase displayed high substrate specificity towards L-asparagine with Km, kcat, and kcat/Km values of 6.025 mM, 11,864.71 min−1, and 1969.25 mM−1min−1, respectively. To evaluate its ability to mitigate acrylamide, GmASNase was used to treat potato chips prior to frying, where the acrylamide content decreased by 65.09% compared with the untreated control. These results suggest that GmASNase is a potential candidate for applications in the food industry.

Identification of N-glycans with GalNAc-containing antennae from recombinant HIV trimers by ion mobility and negative ion fragmentation

Negative ion collision-induced dissociation (CID) of underivatized N-glycans has proved to be a simple, yet powerful method for their structural determination. Recently, we have identified a series of such structures with GalNAc rather than the more common galactose capping the antennae of hybrid and complex glycans. As part of a series of publications describing the negative ion fragmentation of different types of N-glycan, this paper describes their CID spectra and estimated nitrogen cross sections recorded by travelling wave ion mobility mass spectrometry (TWIMS). Most of the glycans were derived from the recombinant glycoproteins gp120 and gp41 from the human immunodeficiency virus (HIV), recombinantly derived from human embryonic kidney (HEK 293T) cells. Twenty-six GalNAc-capped hybrid and complex N-glycans were identified by a combination of TWIMS, negative ion CID, and exoglycosidase digestions. They were present as the neutral glycans and their sulfated and α2→3-linked sialylated analogues. Overall, negative ion fragmentation of glycans generates fingerprints that reveal their structural identity.

Structural Phylogeny of Different Allergens May Reveal Common Epitopic Footprint

Background: The incidence of allergy is increasing at an alarming rate for the last few decades. Objective: Our present study is focused on finding out the structurally homologous motifs present in different proteinaceous allergens Methods: Significant number of protein sequences and their corresponding structures of various pollen, fungal, bacterial, and food allergens were retrieved, and the sequence and structural identity were analyzed. Results: Intra- and inter-sequence and their structural analysis of the proteinaceous allergens, resulted in no significant relationships among them. A few, but not negligible number of high structural similarities were observed within different groups of allergens from fungus, angiosperms, and animals (Aves and Mammalia). Conclusion: Our in silico study on thirty-six different allergens showed a significant level of structural similarities among themselves, regardless of their sequences.

Coumarin-Annulated Ferrocenyl 1,3-Oxazine Derivatives Possessing In Vitro Antimalarial and Antitrypanosomal Potency

A tailored series of coumarin-based ferrocenyl 1,3-oxazine hybrid compounds was synthesized and investigated for potential antiparasitic activity, drawing inspiration from the established biological efficacy of the constituent chemical motifs. The structural identity of the synthesized compounds was confirmed by common spectroscopic techniques: NMR, HRMS and IR. Biological evaluation studies reveal that the compounds exhibit higher in vitro antiparasitic potency against the chemosensitive malarial strain (3D7 P. falciparum) over the investigated trypanosomiasis causal agent (T. b. brucei 427) with mostly single digit micromolar IC50 values. When read in tandem with the biological performance of previously reported structurally similar non-coumarin, phenyl derivatives (i.e., ferrocenyl 1,3-benzoxazines and α-aminocresols), structure-activity relationship analyses suggest that the presence of the coumarin nucleus is tolerated for biological activity though this may lead to reduced efficacy. Preliminary mechanistic studies with the most promising compound (11b) support hemozoin inhibition and DNA interaction as likely mechanistic modalities by which this class of compounds may act to produce plasmocidal and antitrypanosomal effects.

Fragments and structural identity on a direct interpretation approach

This paper examines the relationship between merger and sprouting fragments, which are typically taken to involve clausal ellipsis. We argue that structural identity constraints on fragments and their correlates should, where appropriate, make reference to the argument structure of lexical heads in the antecedent clauses. Our proposal is spelled out as part of a direct interpretation approach to clausal ellipsis, but, in addition, it incorporates processing-based preferences as a means to motivate the contrast between merger and sprouting fragments. We propose specifically that phrases which are available to serve as correlates for fragments are maximal categories derived from the argument structure of lexical heads in the antecedents. This proposal successfully predicts form-matching effects that surface under clausal ellipsis, as well as well-known limits on clausal ellipsis regarding the morphosyntactic form of fragments. We take advantage of the fact that fragments are not embedded in unpronounced structures, which allows us to articulate a proposal that avoids the difficulty of having to simultaneously relate a fragment to the structure of the antecedent and to its own unpronounced structure, a difficulty that current PF-deletion accounts face.

Preservation of the structure of the building in the process of renovation of industrial architecture

The renovation of industrial buildings has become relevant recently with increasing interest in former industrial areas that need to rethink their importance in the city without losing their identity. Based on the previous scientific works of the authors, we reveal one of the principles of preserving identity in the renovation of industrial buildings – the principle of preserving the structural identity of the building. In this scientific study, we analyze the existing experience of preserving structures during renovation and consider this principle in practice, namely, the renovation of the mill building erected in 1912 in the urban-type settlement of Apastovo, Republic of Tatarstan, Russia. The practical significance of the work lies in the possibility of applying the results of the study in modern architectural practice, in particular in the reconstruction of industrial buildings in historical cities of Russia. This work can become the basis for further research, identifying valuable areas for the development of industrial formations.

First among equals: co-hyperintensionality for structured propositions

Theories of structured meanings are designed to generate fine-grained meanings, but they are also liable to overgenerate structures, thus drawing structural distinctions without a semantic difference. I recommend the proliferation of very fine-grained structures, so that we are able to draw any semantic distinctions we think we might need. But, in order to contain overgeneration, I argue we should insert some degree of individuation between logical equivalence and structural identity based on structural isomorphism. The idea amounts to forming an equivalence class of different structures according to one or more formal criteria and designating a privileged element as a representative of all the elements, i.e., a first among equals. The proposed method helps us to a cluster of notions of co-hyperintensionality. As a test case, I consider a recent objection levelled against the act theory of structured propositions. I also respond to an objection against my methodology.

ANTIOXIDANT ACTIVITY OF TRITERPENE GLYCOSIDE (CORTUSOSIDE A) FROM CORTUSA MATTHIOLI L. PLANT

The antioxidant activity of triterpene glycoside, first isolated from the aboveground part of the plant Cortusa matthioli L. and identified as β-D-xylopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranoside-(1→3)-13β,28-epoxyolean-30-al-3β,16α-diol (cortusoside A), is studied. Tests for the ability of cortusoside A to bind 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals did not reveal any activity of this compound. However, in experiments to study the ability to chelate Fe2+ ions, its sufficiently high iron chelating activity was found, which was only 2.24 times lower compared to the powerful Fe2+ chelator dipyridyl. The EC50 values for cortusoside A and dipyridyl were 0.417±0.057 and 0.186±0.018 mM, respectively. Literature analysis has shown that the structural analogue of cortusoside A, saxifragifolin B, has a much weaker iron chelating ability (13,4 times) compared to the standard Fe2+ EDTA-Na2 ion chelator, as well as a weak ability to bind free radicals of DPPH compared to the reference antioxidants – catechin and ascorbic acid (50 and 32 times, respectively). Despite the structural identity of the molecules cortusoside A and saxifragifolin B, low radiculopathy activity cortusosoide A may be due to differences in the structure of these substances (optical or geometric isomerism), as well as different methods were used in its definition.

Dealing with PET radiometabolites

Positron emission tomography (PET) offers the study of biochemical, physiological, and pharmacological functions at a cellular and molecular level. The performance of a PET study mostly depends on the used radiotracer of interest. However, the development of a novel PET tracer is very difficult, as it is required to fulfill a lot of important criteria. PET radiotracers usually encounter different chemical modifications including redox reaction, hydrolysis, decarboxylation, and various conjugation processes within living organisms. Due to this biotransformation, different chemical entities are produced, and the amount of the parent radiotracer is declined. Consequently, the signal measured by the PET scanner indicates the entire amount of radioactivity deposited in the tissue; however, it does not offer any indication about the chemical disposition of the parent radiotracer itself. From a radiopharmaceutical perspective, it is necessary to quantify the parent radiotracer’s fraction present in the tissue. Hence, the identification of radiometabolites of the radiotracers is vital for PET imaging. There are mainly two reasons for the chemical identification of PET radiometabolites: firstly, to determine the amount of parent radiotracers in plasma, and secondly, to rule out (if a radiometabolite enters the brain) or correct any radiometabolite accumulation in peripheral tissue. Besides, radiometabolite formations of the tracer might be of concern for the PET study, as the radiometabolic products may display considerably contrasting distribution patterns inside the body when compared with the radiotracer itself. Therefore, necessary information is needed about these biochemical transformations to understand the distribution of radioactivity throughout the body. Various published review articles on PET radiometabolites mainly focus on the sample preparation techniques and recently available technology to improve the radiometabolite analysis process. This article essentially summarizes the chemical and structural identity of the radiometabolites of various radiotracers including [11C]PBB3, [11C]flumazenil, [18F]FEPE2I, [11C]PBR28, [11C]MADAM, and (+)[18F]flubatine. Besides, the importance of radiometabolite analysis in PET imaging is also briefly summarized. Moreover, this review also highlights how a slight chemical modification could reduce the formation of radiometabolites, which could interfere with the results of PET imaging. Graphical abstract