Estimating vertex-degree-based energies

Introduction/purpose: In the current literature, several dozens of vertex-degree-based (VDB) graph invariants are being studied. To each such invariant, a matrix can be associated. The VDB energy is the energy (= sum of the absolute values of the eigenvalues) of the respective VDB matrix. The paper examines some general properties of the VDB energy of bipartite graphs. Results: Estimates (lower and upper bounds) are established for the VDB energy of bipartite graphs in which there are no cycles of size divisible by 4, in terms of ordinary graph energy. Conclusion: The results of the paper contribute to the spectral theory of VDB matrices, especially to the general theory of VDB energy.

Polyureas Versatile Polymers for New Academic and Technological Applications

Polyureas (PURs) are a competitive polymer to their analogs, polyurethanes (PUs). Whereas PUs’ main functional group is carbamate (urethane), PURs contain urea. In this revision, a comprehensive overview of PUR properties, from synthesis to technical applications, is displayed. Preparative routes that can be used to obtain PURs using diisocianates or harmless reagents such as CO2 and NH3 are explained, and aterials, urea monomers and PURs are discussed; PUR copolymers are included in this discussion as well. Bulk to soft components of PUR, as well as porous materials and meso, micro or nanomaterials are evaluated. Topics of this paper include the general properties of aliphatic and aromatic PUR, followed by practical synthetic pathways, catalyst uses, aggregation, sol–gel formation and mechanical aspects.

Mutations in DISC1 alter IP3R and Voltage-Gated Ca2+ Channel Functioning: Implications for Major Mental Illness

Disrupted in Schizophrenia 1 (DISC1) participates in a wide variety of developmental processes of central neurons. It also serves critical roles that underlie cognitive functioning in adult central neurons. Here we summarize DISC1’s general properties and discuss its use as a model system for understanding major mental illnesses. We then discuss the cellular actions of DISC1 that involve or regulate Ca2+ signaling in adult central neurons. In particular, we focus on the tethering role DISC1 plays in transporting RNA particles containing Ca2+ channel subunit RNAs, including IP3R1, CACNA1C and CACNA2D1, and in transporting mitochondria into dendritic and axonal processes. We also review DISC1’s role in modulating IP3R1 activity within mitochondria-associated ER membrane. Finally, we discuss DISC1-GSK3b signaling that regulates functional expression at voltage-gated Ca2+ channel at central synapses. In each case, DISC1 regulates the movement of molecules that impact Ca2+ signaling in neurons.

Subcellular localization defects characterize ribose-binding mutant proteins with new ligand properties in Escherichia coli

Periplasmic-binding proteins have been previously proclaimed as a general scaffold to design sensor proteins with new recognition specificities for non-natural compounds. Such proteins can be integrated in bacterial bioreporter chassis with hybrid chemoreceptors to produce a concentration-dependent signal after ligand binding to the sensor cell. However, computationally designed new ligand-binding properties ignore the more general properties of periplasmic binding proteins, such as their periplasmic translocation, dynamic transition of open and closed forms, and interactions with membrane receptors. In order to better understand the roles of such general properties in periplasmic signaling behaviour, we study here the subcellular localization of ribose-binding protein (RbsB) in Escherichia coli in comparison to a recently evolved set of mutants designed to bind 1,3-cyclohexanediol. As proxies for localization we calibrate and deploy C-terminal end mCherry fluorescent protein fusions. Whereas RbsB-mCherry coherently localized to the periplasmic space and accumulated in (periplasmic) polar regions depending on chemoreceptor availability, mutant RbsB-mCherry expression resulted in high fluorescence cell-to-cell variability. This resulted in higher proportions of cells devoid of clear polar foci and of cells with multiple fluorescent foci elsewhere, suggesting poorer translocation, periplasmic autoaggregation and mislocalization. Analysis of RbsB mutants and mutant libraries at different stages of directed evolution suggested overall improvement to more RbsB-wild-type-like characteristics, which was corroborated by structure predictions. Our results show that defects in periplasmic localization of mutant RbsB proteins partly explains their poor sensing performance. Future efforts should be directed to predicting or selecting secondary mutations outside computationally designed binding pockets that take folding, translocation and receptor-interactions into account. Importance Biosensor engineering relies on transcription factors or signaling proteins to provide the actual sensory functions for the target chemicals. Since for many compounds there are no natural sensory proteins, there is a general interest in methods that could unlock routes to obtaining new ligand-binding properties. Bacterial periplasmic-binding proteins (PBPs) form an interesting family of proteins to explore to this purpose, because there is a large natural variety suggesting evolutionary trajectories to bind new ligands. PBPs are conserved and amenable to accurate computational binding pocket predictions. However, studying ribose-binding protein in Escherichia coli we discovered that designed variants have defects in their proper localization in the cell, which can impair appropriate sensor signaling. This indicates that functional sensing capacity of PBPs cannot be obtained solely through computational design of the ligand-binding pocket, but must take other properties of the protein into account, which are currently very difficult to predict.

General properties of exchange rate of national money versus some foreign currencies in Albania

In this work we have considered the study of the exchange rate series for the specific case where the formal financial market is not active. In those situations, we would be interested in the parallelization of the exchange rate with financial indexes for stabilized financial market. We observed that the stationarity of the distribution for some the exchange rate of currencies traded in the country differs significantly. The time dynamics shows the presence of the elements of local critical behavior, but those tendencies attenuate and fade away in an a periodic fashion. Next, we considered and evidenced the correlation distances and dissimilarity between exchange rates of national currencies versus euro and dollar and golden prices. It resulted that two exchange rates do have different distance from golden price taken for references. The correlation distance between the series of the return in different period has evidenced that there is not a regular behavior in this respect.

Elementary analitical models of atmosphere

Для понимания физики и общих свойств экзопланет важно изучать свойства их атмосфер. В статье последовательно рассматриваются гидростатические и стационарные решения уравнений газодинамики для исследования структуры течения атмосфер экзопланет в изотермическом и адиабатическом приближениях. Данные решения, несмотря на их абстрактный характер, важны для понимания физики процесса истечения и играют роль опорных точек при разработке более реалистичных моделей. To understand the physics and general properties of exoplanets it is important to study the properties of their atmospheres. In this paper, we sequentially discuss the hydrostatical and hydrodynamical stationary solutions for an exoplanet atmosphere in isothermal and adiabatic approximations. These solutions, despite their abstract nature, are important for understanding the physics of the outflow process and play the role of reference points in the development of more realistic models.

General Properties on Differential Sets of a Graph

Let G=(V,E) be a graph, and let β∈R. Motivated by a service coverage maximization problem with limited resources, we study the β-differential of G. The β-differential of G, denoted by ∂β(G), is defined as ∂β(G):=max{|B(S)|−β|S|suchthatS⊆V}. The case in which β=1 is known as the differential of G, and hence ∂β(G) can be considered as a generalization of the differential ∂(G) of G. In this paper, upper and lower bounds for ∂β(G) are given in terms of its order |G|, minimum degree δ(G), maximum degree Δ(G), among other invariants of G. Likewise, the β-differential for graphs with heavy vertices is studied, extending the set of applications that this concept can have.

Concept of standard raw drug substitution in Traditional Siddha Medicine - A Review

Classical Siddha medicine recommends the usage of functionally parallel substitute raw drugs in the scarcity of the original material. The concept of standard raw drug substitution is designated by the Tamil term Matru sarakku, which emphasizes selecting alternatives either in herbal or non-herbal sources based on certain attributes. Functionally similar materials are suggested for balancing the deficit based on such parameters. Literature sources from Siddha medicine and other allied subjects were explored and documented for the inclusive understanding of the concept of ideal substitution. Few of the standard substitutes mentioned in the classical Siddha literature were evaluated in a scientific account for its justification. An outlook on different specimens as described in the ancient texts of Tamil medicine indicates the usage of substitutes from numerous plants, animals, and other metallo-mineral ingredients. The rationale of selecting alternatives primarily depends on the equivalent following traditional attributes like organoleptic entities, potency, division, general properties, specific actions, and medicinal uses of the material shared between the raw drugs. This must undergo a systematic evaluation by pharmacognostic and phytochemical studies to justify current practices of substitution. A systematic document in these lines will give a proper guideline for the effective employment of substitute drugs in the current scenario of dwindling official botanical sources for many Traditional Siddha formulations.