There are emerging tensions for theory results of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment both within recent lattice QCD calculations and between some ...lattice QCD calculations and R-ratio results. In this paper, we work toward scrutinizing critical aspects of these calculations. We focus in particular on a precise calculation of Euclidean position-space windows defined by RBC/UKQCD that are ideal quantities for cross-checks within the lattice community and with R-ratio results. We perform a lattice QCD calculation using physical up, down, strange, and charm sea quark gauge ensembles generated in the staggered formalism by the MILC Collaboration. We study the continuum limit using inverse lattice spacings from a−1 ≈ 1.6 GeV to 3.5 GeV, identical to recent studies by FNAL/HPQCD/MILC and Aubin et al. and similar to the recent study of BMW. Our calculation exhibits a tension for the particularly interesting window result of a ud , conn . , isospin , W μ from 0.4 to 1.0 fm with previous results obtained with a different discretization of the vector current on the same gauge configurations. Our results may indicate a difficulty related to estimating uncertainties of the continuum extrapolation that deserves further attention. In this work, we also provide results for aud, conn., isospinμ, as, conn., isospinμ , a SIB, conn.μ for the total contribution and a large set of windows. For the total contribution, we find aHVP LOμ = 714 (27) (13) 10−10 , aud , conn . , isospin μ = 657 (26) (12) 10−10 , as, conn., isospinμ = 52.83 (22) (65) 10−10, and a SIB, conn.μ = 9.0 (0.8) (1.2) 10−10 , where the first uncertainty is statistical and the second systematic. We also comment on finite-volume corrections for the strong-isospin-breaking corrections.
Domestication is a good model for the study of evolutionary processes because of the recent evolution of crop species (<12,000 years ago), the key role of selection in their origins, and good ...archaeological and historical data on their spread and diversification. Recent studies, such as quantitative trait locus mapping, genome-wide association studies and whole-genome resequencing studies, have identified genes that are associated with the initial domestication and subsequent diversification of crops. Together, these studies reveal the functions of genes that are involved in the evolution of crops that are under domestication, the types of mutations that occur during this process and the parallelism of mutations that occur in the same pathways and proteins, as well as the selective forces that are acting on these mutations and that are associated with geographical adaptation of crop species.
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Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In recent years, enzyme immobilization has been presented as a powerful tool for the improvement of enzyme properties such as stability and reusability. However, the type of support material used ...plays a crucial role in the immobilization process due to the strong effect of these materials on the properties of the produced catalytic system. A large variety of inorganic and organic as well as hybrid and composite materials may be used as stable and efficient supports for biocatalysts. This review provides a general overview of the characteristics and properties of the materials applied for enzyme immobilization. For the purposes of this literature study, support materials are divided into two main groups, called Classic and New materials. The review will be useful in selection of appropriate support materials with tailored properties for the production of highly effective biocatalytic systems for use in various processes.
Recently, it has been predicted that the Andreev bound state spectrum of four-terminal Josephson junctions may possess zero-energy Weyl singularities. Using one superconducting phase as a control ...parameter, these singularities are associated with topological transitions between time-reversal symmetry broken phases with different Chern numbers. Here we show that such topological transitions may also be tuned with a magnetic flux through the junction area in a three-terminal geometry.
Keratin is an insoluble and protein-rich epidermal material found in e.g. feather, wool, hair. It is produced in substantial amounts as co-product from poultry processing plants and pig ...slaughterhouses. Keratin is packed by disulfide bonds and hydrogen bonds. Based on the secondary structure, keratin can be classified into α-keratin and β-keratin. Keratinases (EC 3.4.-.- peptide hydrolases) have major potential to degrade keratin for sustainable recycling of the protein and amino acids. Currently, the known keratinolytic enzymes belong to at least 14 different protease families: S1, S8, S9, S10, S16, M3, M4, M14, M16, M28, M32, M36, M38, M55 (MEROPS database). The various keratinolytic enzymes act via endo-attack (proteases in families S1, S8, S16, M4, M16, M36), exo-attack (proteases in families S9, S10, M14, M28, M38, M55) or by action only on oligopeptides (proteases in families M3, M32), respectively. Other enzymes, particularly disulfide reductases, also play a key role in keratin degradation as they catalyze the breakage of disulfide bonds for better keratinase catalysis. This review aims to contribute an overview of keratin biomass as an enzyme substrate and a systematic analysis of currently sequenced keratinolytic enzymes and their classification and reaction mechanisms. We also summarize and discuss keratinase assays, available keratinase structures and finally examine the available data on uses of keratinases in practical biorefinery protein upcycling applications.
•Overview of keratin as an enzyme substrate for circular economy biorefining•Details of α-keratin and β-keratin•Examination of microbial keratinases: Protein family, origin, reaction optima•Critical assessment of keratinase enzyme assays•Structure-function analysis of all known endo-keratinolytic proteases
Carrageenan, agar, and alginate are seaweed-derived carbohydrate hydrocolloids which are used as thickening and gelling agents in foods, pharma and biotechnology applications due to their unique ...gelation properties. These hydrocolloids are extracted commercially from a set of high-yielding, cultivated seaweeds (marine macroalgae). The seaweed type and biological and environmental factors during seaweed growth determine the chemical and rheological hydrocolloid properties. New insight into biosynthesis and microbial degradation of these seaweed-derived hydrocolloids includes discovery of unique enzymes that catalyze specific structural changes in the carbohydrate polymers which affect the hydrocolloid properties.
In this review we describe the intricate chemical structures, gelation mechanisms and biosynthesis routes of seaweed hydrocolloids. We provide an overview of novel enzymes and enzyme reactions that catalyze changes in these hydrocolloids, and discuss how this new enzyme knowledge may enable further technological advancements in processing and applications of seaweed hydrocolloids.
The red seaweeds from the genera Kappaphycus and Eucheuma are key commercial sources of carrageenan, species from the genera Gracilaria and Gelidium are the main sources of agar, and brown seaweeds from the genera Laminaria and Macrocystis are currently the main sources of alginate. Recent progress has advanced our understanding of enzymatic reactions involved in the biosynthesis and microbial degradation of these hydrocolloids and especially uncovered unique epimerase, desulfatase, and alginate lyase processes. This new knowledge provides a basis for rethinking the sources and extraction protocols of these hydrocolloids because such enzymes can catalyze distinct molecular changes to improve the physical properties of the hydrocolloids.
•Chemical structures of seaweed-derived hydrocolloids carrageenans, agar, alginate.•Illustrated gelation mechanisms of seaweed-derived hydrocolloids.•Update of biosynthesis of cell wall hydrocolloid carbohydrates in seaweeds.•New microbial enzymes that catalyze modifications of carrageenans, agar, alginate.
ABSTRACT Carbon-enhanced metal-poor (CEMP) stars in the Galactic Halo display enrichments in heavy elements associated with either the s (slow) or the r (rapid) neutron-capture process (e.g., barium ...and europium, respectively), and in some cases they display evidence of both. The abundance patterns of these CEMP-s/r stars, which show both Ba and Eu enrichment, are particularly puzzling, since the s and the r processes require neutron densities that are more than ten orders of magnitude apart and, hence, are thought to occur in very different stellar sites with very different physical conditions. We investigate whether the abundance patterns of CEMP-s/r stars can arise from the nucleosynthesis of the intermediate neutron-capture process (the i process), which is characterized by neutron densities between those of the s and the r processes. Using nuclear network calculations, we study neutron capture nucleosynthesis at different constant neutron densities n ranging from 107-1015 cm−3. With respect to the classical s process resulting from neutron densities on the lowest side of this range, neutron densities on the highest side result in abundance patterns, which show an increased production of heavy s-process and r-process elements, but similar abundances of the light s-process elements. Such high values of n may occur in the thermal pulses of asymptotic giant branch stars due to proton ingestion episodes. Comparison to the surface abundances of 20 CEMP-s/r stars shows that our modeled i-process abundances successfully reproduce observed abundance patterns, which could not be previously explained by s-process nucleosynthesis. Because the i-process models fit the abundances of CEMP-s/r stars so well, we propose that this class should be renamed as CEMP-i.
Activity of the hypothalamic-pituitary-adrenocortical (HPA) axis is commonly assessed by measuring glucocorticoids such as cortisol (CORT). For many years, CORT was obtained primarily from blood ...plasma or urine, whereas later approaches added saliva and feces for noninvasive monitoring of HPA functioning. Despite the value of all these sample matrices for answering many research questions, they remain limited in the temporal range of assessment. Plasma and saliva are point samples that vary as a function of circadian rhythmicity and are susceptible to confounding by environmental disturbances. Even urine and feces generally assess HPA activity over a period of only 24 h or less. We and others have recently developed and validated methods for measuring the concentration of CORT in the body hair of animals (e.g. rhesus monkeys) and scalp hair of humans. CORT is constantly deposited in the growing hair shaft, as a consequence of which such deposition can serve as a biomarker of integrated HPA activity over weeks and months instead of minutes or hours. Since the advent of this methodological advance, hair CORT has already been used as an index of chronic HPA activity and stress in human clinical and nonclinical populations, in a variety of laboratory-housed and wild-living animal species, and in archival specimens that are many decades or even centuries old. Moreover, because human hair is known to grow at an average rate of about 1 cm/month, several studies suggest that CORT levels in hair segments that differ in proximity to the scalp can, under certain conditions, be used as a retrospective calendar of HPA activity during specific time periods preceding sample collection.
Topological materials and their unusual transport properties are now at the focus of modern experimental and theoretical research. Their topological properties arise from the bandstructure determined ...by the atomic composition of a material and as such are difficult to tune and naturally restricted to ≤3 dimensions. Here we demonstrate that n-terminal Josephson junctions with conventional superconductors may provide novel realizations of topology in n-1 dimensions, which have similarities, but also marked differences with existing 2D or 3D topological materials. For n≥4, the Andreev subgap spectrum of the junction can accommodate Weyl singularities in the space of the n-1 independent superconducting phases, which play the role of bandstructure quasimomenta. The presence of these Weyl singularities enables topological transitions that are manifested experimentally as changes of the quantized transconductance between two voltage-biased leads, the quantization unit being 4e(2)/h, where e is the electric charge and h is the Planck constant.
Seaweeds--or marine macroalgae--notably brown seaweeds in the class Phaeophyceae, contain fucoidan. Fucoidan designates a group of certain fucose-containing sulfated polysaccharides (FCSPs) that have ...a backbone built of (1→3)-linked α-L-fucopyranosyl or of alternating (1→3)- and (1→4)-linked α-L-fucopyranosyl residues, but also include sulfated galactofucans with backbones built of (1→6)-β-D-galacto- and/or (1→2)-β-D-mannopyranosyl units with fucose or fuco-oligosaccharide branching, and/or glucuronic acid, xylose or glucose substitutions. These FCSPs offer several potentially beneficial bioactive functions for humans. The bioactive properties may vary depending on the source of seaweed, the compositional and structural traits, the content (charge density), distribution, and bonding of the sulfate substitutions, and the purity of the FCSP product. The preservation of the structural integrity of the FCSP molecules essentially depends on the extraction methodology which has a crucial, but partly overlooked, significance for obtaining the relevant structural features required for specific biological activities and for elucidating structure-function relations. The aim of this review is to provide information on the most recent developments in the chemistry of fucoidan/FCSPs emphasizing the significance of different extraction techniques for the structural composition and biological activity with particular focus on sulfate groups.
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