Publications by authors named "Rubtsov A"

Article Synopsis
  • Under allopatric speciation, species are isolated by geographic barriers, leading to genetic changes and potential reproductive isolation.
  • The yellowhammer and pine bunting diverged during the Pleistocene but have shown weak reproductive barriers, as evidenced by extensive hybridization in their overlapping regions of Siberia.
  • Genomic analysis indicates that admixture is significant, suggesting that the two species might either continue to differentiate or merge, while also revealing a genetic inversion linked to plumage variation that could preserve these differences even if they do merge.
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  • - The Landau free energy helps describe how order parameters fluctuate in physical systems at thermal equilibrium, especially during critical phenomena.
  • - A new semianalytical approach is introduced, utilizing the fluctuating local field method for estimating Landau free energy.
  • - This method can be applied to small clusters in both discrete (Ising model) and continuous (Heisenberg model) types of order parameters.
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  • Gaussian boson sampling (GBS) is a problem that could show how quantum computing is better than classical computing.
  • An algorithm is introduced to simulate GBS classically using a Taylor series expansion, achieving higher accuracy with more terms.
  • The conditions for optimal performance of the algorithm are identified, which match those in recent experiments claiming quantum advantage, allowing for classical simulation of those experiments.
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The design and synthesis of new promising compounds based on thienopyrimidine scaffold containing 2-aminothiophene fragments with good safety and favorable drug-like properties are highly relevant for chemotherapy. In this study, a series of 14 variants of thieno[3,2-e]pyrrolo[1,2-a]pyrimidine derivatives (11aa-oa) and their precursors (31 compounds) containing 2-aminothiophenes fragments (9aa-mb, 10aa-oa) were synthesized and screened for their cytotoxicity against B16-F10 melanoma cells. The selectivity of the developed compounds was assessed by determining the cytotoxicity using normal mouse embryonic fibroblasts (MEF NF2 cells).

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  • The study explores the use of phase-stable light pulses to control quantum systems, particularly focusing on many-body systems with spins.
  • A single, brief control pulse can generate a significant population imbalance between two equivalent ground states in the Ising model.
  • This technique paves the way for fast data processing and storage, enabling all-optical control over the final states of correlated quantum systems.
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The original formulation of the boson sampling problem assumed that little or no photon collisions occur. However, modern experimental realizations rely on setups where collisions are quite common, i.e.

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Comparisons of genomic variation among closely related species often show more differentiation in mitochondrial DNA (mtDNA) and sex chromosomes than in autosomes, a pattern expected due to the differing effective population sizes and evolutionary dynamics of these genomic components. Yet, introgression can cause species pairs to deviate dramatically from general differentiation trends. The yellowhammer (Emberiza citrinella) and pine bunting (E.

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  • Research discusses how current global climate models are based on air temperatures but fail to capture the soil temperatures beneath vegetation where many species thrive.
  • New global maps present soil temperature and bioclimatic variables at 1-km resolution for specific depths, revealing that mean annual soil temperatures can differ significantly from air temperatures by up to 10°C.
  • The findings indicate that relying on air temperature could misrepresent climate impacts on ecosystems, especially in colder regions, highlighting the need for more precise soil temperature data for ecological studies.
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We study the impact of a few cycle extreme terahertz (THz) radiation (the field strength E ∼1-15 MV/cm is well above the DC-field breakdown threshold) on a p-doped Si wafer. Pump-probe measurements of the second harmonic of a weak infrared probe were done at different THz field strengths. The second harmonic yield has an unusual temporal behavior and does not follow the common instantaneous response, ∝TH2.

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Sex chromosomes often bear distinct patterns of genetic variation due to unique patterns of inheritance and demography. The processes of mutation, recombination, genetic drift and selection also influence rates of evolution on sex chromosomes differently than autosomes. Measuring such differences provides information about how these processes shape genomic variation and their roles in the origin of species.

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Bacterial persistence coupled with biofilm formation is directly associated with failure of antibiotic treatment of tuberculosis. We have now identified 4-(4,7-DiMethyl-1,2,3,4-tetrahydroNaphthalene-1-yl)Pentanoic acid (DMNP), a synthetic diterpene analogue, as a lead compound that was capable of suppressing persistence and eradicating biofilms in Mycobacterium smegmatis. By using two reciprocal experimental approaches - Δrel and ΔrelZ gene knockout mutations versus rel and relZ overexpression technique - we showed that both Rel and RelZ (p)ppGpp synthetases are plausible candidates for serving as targets for DMNP.

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  • A specific type of B cells, known as age-associated B cells (ABCs), is found in higher numbers in individuals with infections or autoimmune conditions.
  • Researchers aimed to determine the levels of ABC-like cells in patients with lung granulomatous diseases, such as sarcoidosis.
  • Results showed that patients with sarcoidosis had elevated levels of ABC-like cells in both blood and bronchoalveolar lavage (BAL) samples, and treatment led to a decrease in these cells, indicating a potential role for ABC-like cells in diagnosis and treatment strategies for lung diseases.
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A new, efficient, and versatile one-pot cascade reaction of diverse Gewald's aminothiophenes, 2-hydroxy-4-oxobut-2-enoic acid, and derivatives of cyanoacetic acid catalyzed by EtN is presented. It enables direct synthesis of diverse 1-(2-oxoethylidene)-2-oxothieno[3,2-]pyrrolo[1,2-]pyrimidine in good to excellent yields. The reaction exhibits a broad substrate scope and also presents an opportunity for further modification of the structure.

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Migratory divides are proposed to be catalysts for speciation across a diversity of taxa. However, it is difficult to test the relative contributions of migratory behaviour vs. other divergent traits to reproductive isolation.

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Bipyridine N,N'-dioxide is a structural fragment found in many bioactive compounds. Furthermore, chiral analogues secured their place as powerful Lewis base catalysts. The scope of the existing methods for the synthesis of atropisomeric bipyridine N,N'-dioxides is limited.

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Thermal-equilibrated finite classical lattices are considered as a minimal model of the systems showing an interplay between low-energy collective fluctuations and single-site degrees of freedom. Standard local field approach, as well as classical limit of the bosonic DMFT method, do not provide a satisfactory description of Ising and Heisenberg small lattices subjected to an external polarizing field. We show that a dramatic improvement can be achieved within a simple approach, in which the local field appears to be a fluctuating quantity related to the low-energy degree(s) of freedom.

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A highly expedient protocol for a catalytic Appel-type dehydration of amides to nitriles has been developed that employs oxalyl chloride and triethylamine along with triphenylphosphine oxide as a catalyst. The reactions are usually complete in less than 10 min with only a 1 mol % catalyst loading. The reaction scope includes aromatic, heteroaromatic, and aliphatic amides, including derivatives of α-hydroxy and α-amino acids.

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A mild, efficient protocol for oxidative cleavage of C-C bonds in aldehydes has been developed that employs alkali metal hydrides as reagents and oxygen from air as a terminal oxidant. The method is applicable to a broad substrate range.

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Hybrid zones are geographic regions where isolating barriers between divergent populations are challenged by admixture. Identifying factors that facilitate or inhibit hybridization in sympatry can illuminate the processes that maintain those reproductive barriers. We analysed patterns of hybridization and phenotypic variation across two newly discovered hybrid zones between three subspecies of barn swallow (Hirundo rustica).

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Autoimmune diseases affect more than 23.5million Americans. Traditional therapies for autoimmune diseases involve immunosuppressive drugs that globally dampen immune responses or target and kill large populations of normal immune cells.

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B cells contribute to multiple aspects of autoimmune disorders and may play a role in triggering disease. Thus, targeting B cells may be a promising strategy for treating autoimmune disorders. Better understanding of the B cell subsets that are responsible for the development of autoimmunity will be critical for developing efficient therapies.

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An expedient procedure for catalytic oxidative azo-ene cyclization of allylic and homoallylic 1,2-hydrazinedicarboxylates is reported. The reaction produced a wide range of cyclic carbamate derivatives featuring an appended alkene fragment ready for further functionalization.

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Knowledge of the processes that underlie IgG subclass switching could inform strategies designed to counteract infections and autoimmunity. Here we show that TLR7 ligands induce subsets of memory CD4 and CD8 T cells to secrete interferon γ (IFNγ) in the absence of antigen receptor stimulation. In turn, TLR ligation and IFNγ cause B cells to express the transcription factor, T-bet, and to switch immunoglobulin production to IgG2a/c.

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A short, nine-step, highly enantioselective synthesis of (-)-erogorgiaene and its C-11 epimer is reported. The key stereochemistry controlling steps involve catalytic asymmetric crotylation, anionic oxy-Cope rearrangement and cationic cyclisation. (-)-Erogorgiaene exhibited promising antitubercular activity against multidrug-resistant strains of Mycobacterium tuberculosis.

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Relaxation dynamics of complex quantum systems with strong interactions towards the steady state is a fundamental problem in statistical mechanics. The steady state of subsystems weakly interacting with their environment is described by the canonical ensemble which assumes the probability distribution for energy to be of the Boltzmann form. The emergence of this probability distribution is ensured by the detailed balance of the transitions induced by the interaction with the environment.

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