Explore the vast range of titles available.

Unexpectedly severe winter weather, which is arguably exogenous to firm and bank fundamentals, represents a significant cash flow shock for bank-borrowing firms. Firms respond to these shocks by drawing on and increasing the size of their credit lines. Banks charge borrowers for this liquidity via increased interest rates and less borrower-friendly loan provisions. Credit line adjustments occur within one calendar quarter of the shock and persist for at least nine months. Overall, we provide evidence that bank credit lines are an important tool for managing the nonfundamental component of cash flow volatility, especially for solvent, small bank borrowers.

Elucidating the complex processes that determine the ability of the human body to adapt to specific intense training programs is critical to improving athletic performance in elite athletes. The present work aims to describe the main hemorheological changes as a result of physical exercises of different intensity, frequency, duration and modes of loading. Sport and physical exertion induce a hemorheological response of different nature and degree, structured in the present paper as follows: erythrocyte aggregation; change in the concentration of basic plasma components; changes in blood flow; changes in blood volume; changes in the endothelial cells of the vascular walls; changes in blood pressure; changes resulting from tissue hypoxia; interacting, different in nature hemorheological consequences. The studied and described original models of hemorheological response can contribute to a more successful adaptation of the training programs—In order to improve the health status of the participants and to optimize the sports form of the elite athletes. Physical loads of different frequencies, intensities and durations induce a different hemorheological response in athletes. The effect of “regular, moderate and properly dosed physical activity” during training is also strictly individual. This fact suggests approaching the training regime of each elite athlete personally, practicing specific to his preparation, well-chosen, balanced physical exercises. This will help to achieve the so-called state of hemorheological fitness. Extensive future research is needed to elucidate the cellular, tissue and molecular mechanism of hemorheological changes in blood, blood cells, and blood plasma. It is essential to study the vascular characteristics and biomechanical properties of blood under physical loads with different regimes and variable parameters, taking into account the individual, professional, biological and mechanical profile of each athlete.

Scalable quantum networking requires quantum systems with quantum processing capabilities. Solid state spin systems with reliable spin–optical interfaces are a leading hardware in this regard. However, available systems suffer from large electron–phonon interaction or fast spin dephasing. Here, we demonstrate that the negatively charged silicon-vacancy centre in silicon carbide is immune to both drawbacks. Thanks to its 4 A 2 symmetry in ground and excited states, optical resonances are stable with near-Fourier-transform-limited linewidths, allowing exploitation of the spin selectivity of the optical transitions. In combination with millisecond-long spin coherence times originating from the high-purity crystal, we demonstrate high-fidelity optical initialization and coherent spin control, which we exploit to show coherent coupling to single nuclear spins with ∼1 kHz resolution. The summary of our findings makes this defect a prime candidate for realising memory-assisted quantum network applications using semiconductor-based spin-to-photon interfaces and coherently coupled nuclear spins. Point defects in solids have potential applications in quantum technologies, but the mechanisms underlying different defects’ performance are not fully established. Nagy et al. show how the wavefunction symmetry of silicon vacancies in SiC leads to promising optical and spin coherence properties.

Spin-active quantum emitters have emerged as a leading platform for quantum technologies. However, one of their major limitations is the large spread in optical emission frequencies, which typically extends over tens of GHz. Here, we investigate single V 4+ vanadium centres in 4H-SiC, which feature telecom-wavelength emission and a coherent S  = 1/2 spin state. We perform spectroscopy on single emitters and report the observation of spin-dependent optical transitions, a key requirement for spin-photon interfaces. By engineering the isotopic composition of the SiC matrix, we reduce the inhomogeneous spectral distribution of different emitters down to 100 MHz, significantly smaller than any other single quantum emitter. Additionally, we tailor the dopant concentration to stabilise the telecom-wavelength V 4+ charge state, thereby extending its lifetime by at least two orders of magnitude. These results bolster the prospects for single V emitters in SiC as material nodes in scalable telecom quantum networks. Several solid-state defect platforms have been proposed for application as a spin-photon interface in quantum communication networks. Here the authors report spin-selective optical transitions and narrow inhomogeneous spectral distribution of V centers in isotopically-enriched SiC emitting in the telecom O-band.

Physical exertion and sport cause changes of different nature and degree (positive or negative, strong, weak, moderate) in blood and blood cells’ biomechanical and fluid properties. The aim of this minireview was to attempt to summarize the main red blood cell deformability alterations during and after physical activity classified as follows: erythrocyte geometric shape; erythrocyte membrane rheological properties; biochemical and structural properties of erythrocyte membrane lipids and proteins; hemoglobin concentration; calcium ion concentration; intracellular diffusion and osmosis; nitric oxide and erythrocyte nitric oxide synthase; erythrocyte ATP synthase; erythrocyte age and degree of erythrocyte cell maturation; body and erythrocyte temperature. It is essential to study and evaluate the individual hemorheological response profile of erythrocyte deformability during physical activity because it is strongly personal. This is one of the major erythrocyte properties determining oxygen supply to working muscles. The multiple hemorheological changes during physical activity and their interconnectedness and strong personality make their differentiation very difficult. It is reasonable to weigh their effects (with specific quantitative measurements) to simplify the analysis and increase the likelihood of obtaining valid conclusions. But there will always be the probabilistic nature of these conclusions, determined by the complex and strictly individual picture of the hemorheological effects of physical exercises and activities.

The CRISPR-Cas9 nuclease has been widely repurposed as a molecular and cell biology tool for its ability to programmably target and cleave DNA. Cas9 recognizes its target site by unwinding the DNA double helix and hybridizing a 20-nucleotide section of its associated guide RNA to one DNA strand, forming an R-loop structure. A dynamic and mechanical description of R-loop formation is needed to understand the biophysics of target searching and develop rational approaches for mitigating off-target activity while accounting for the influence of torsional strain in the genome. Here we investigate the dynamics of Cas9 R-loop formation and collapse using rotor bead tracking (RBT), a single-molecule technique that can simultaneously monitor DNA unwinding with base-pair resolution and binding of fluorescently labeled macromolecules in real time. By measuring changes in torque upon unwinding of the double helix, we find that R-loop formation and collapse proceed via a transient discrete intermediate, consistent with DNA:RNA hybridization within an initial seed region. Using systematic measurements of target and off-target sequences under controlled mechanical perturbations, we characterize position-dependent effects of sequence mismatches and show how DNA supercoiling modulates the energy landscape of R-loop formation and dictates access to states competent for stable binding and cleavage. Consistent with this energy landscape model, in bulk experiments we observe promiscuous cleavage under physiological negative supercoiling. The detailed description of DNA interrogation presented here suggests strategies for improving the specificity and kinetics of Cas9 as a genome engineering tool and may inspire expanded applications that exploit sensitivity to DNA supercoiling.

The main focus of acquaintance theorists has been the nature and mechanism of perceptual acquaintance with particulars. Generally, one’s view of perceptual acquaintance with general features has taken its bearings from one’s view of perceptual acquaintance with particulars. This has led to the glossing over of significant differences in the mechanisms of perceptual acquaintance with particulars and with general features. The difference in mechanisms suggests a difference in the sort of epistemic state at play in the two kinds of cases. While the existence of such a difference might initially seem to spell trouble for acquaintance theorists, it can be made palatable by being traced back to the distinct basic functions concepts of particulars and of general features serve in thought.

The negatively charged silicon vacancy in silicon carbide is a well-studied point defect for quantum applications. At the same time, a closer inspection of ensemble photoluminescence and electron paramagnetic resonance measurements reveals an abundance of related but so far unidentified signals. In this study, we search for defects in 4H-SiC that explain the above magneto-optical signals in a defect database generated by automatic defect analysis and qualification (ADAQ) workflows. This search reveals only one class of atomic structures that exhibit silicon-vacancy-like properties in the data: a carbon antisite (C ) within sub-nanometer distances from the silicon vacancy only slightly alters the latter without affecting the charge or spin state. Such a perturbation is energetically bound. We consider the formation of up to 2 nm distance and report their zero phonon lines and zero field splitting values. In addition, we perform high-resolution photoluminescence experiments in the silicon vacancy region and find an abundance of lines. Comparing our computational and experimental results, several configurations show great agreement. Our work demonstrates the effectiveness of a database with high-throughput results in the search for defects in quantum applications.

Spin-active color centers in solids show good performance for quantum technologies. Several transition-metal defects in SiC offer compatibility with telecom and semiconductor industries. However, whether their strong spin-orbit coupling degrades their spin lifetimes is not clear. We show that a combination of a crystal-field with axial symmetry and spin-orbit coupling leads to a suppression of spin-lattice and spin-spin interactions, resulting in remarkably slow spin relaxation. Our optical measurements on an ensemble of Mo impurities in SiC show a spin lifetime T 1 of 2.4 s at 2 K.

Water samples for bacterial microbiome studies undergo biomass concentration, DNA extraction, and taxonomic identification steps. Through benchmarking, we studied the applicability of skimmed milk flocculation (SMF) for bacterial enrichment, an adapted in-house DNA extraction protocol, and six 16S rRNA databases (16S-DBs). Surface water samples from two rivers were treated with SMF and vacuum filtration (VF) and subjected to amplicon or shotgun metagenomics. A microbial community standard underwent five DNA extraction protocols, taxonomical identification with six different 16S-DBs, and evaluation by the Measurement Integrity Quotient (MIQ) score. In SMF samples, the skimmed milk was metabolized by members of lactic acid bacteria or genera such as Polaromonas, Macrococcus, and Agitococcus, resulting in increased relative abundance (p < 0.5) up to 5.0 log fold change compared to VF, rendering SMF inapplicable for bacterial microbiome studies. The best-performing DNA extraction protocols were FastSpin Soil, the in-house method, and EurX. All 16S-DBs yielded comparable MIQ scores within each DNA extraction kit, ranging from 61–66 (ZymoBIOMICs) up to 80–82 (FastSpin). DNA extraction kits exert more bias toward the composition than 16S-DBs. This benchmarking study provided valuable information to inform future water metagenomic study designs.