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Mashup Score: 57Virological characteristics of the SARS-CoV-2 KP.2 variant - 4 hour(s) ago
The JN.1 variant (BA.2.86.1.1), arising from BA.2.86(.1) with the S:L455S substitution, exhibited increased fitness and outcompeted the previous dominant XBB lineage by the biggening of 2024. JN.1 subsequently diversified, leading to the emergence of descendants with spike (S) protein substitutions such as S:R346T and S:F456L. Particularly, the KP.2 (JN.1.11.1.2) variant, a descendant of JN.1 bearing both S:R346T and S:F456L, is rapidly spreading in multiple regions as of April 2024. Here, we investigated the virological properties of KP.2. KP.2 has three substitutions in the S protein including the two above and additional one substitution in non-S protein compared with JN.1. We estimated the relative effective reproduction number (Re) of KP.2 based on the genome surveillance data from the USA, United Kingdom, and Canada where >30 sequences of KP.2 has been reported, using a Bayesian multinomial logistic model. The Re of KP.2 is 1.22-, 1.32-, and 1.26-fold higher than that of JN.1 in
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Mashup Score: 2Structural basis for molecular assembly of fucoxanthin chlorophyll a/c-binding proteins in a diatom photosystem I supercomplex - 5 hour(s) ago
Light-harvesting complexes (LHCs) in photosynthetic organisms are attached to photosystem I (PSI), forming a PSI-LHCI supercomplex; however, it is unknown how LHCIs recognize their specific binding sites in the PSI core. Here we determine a cryo-electron microscopic structure of a PSI supercomplex containing fucoxanthin chlorophyll a/c-binding proteins (FCPs), namely PSI-FCPI, isolated from the diatom Thalassiosira pseudonana CCMP1335. The PSI-FCPI structure shows five FCPI subunits together with a PSI monomer. The five FCPIs are identified as RedCAP, Lhcr3, Lhcq10, Lhcf10, and Lhcq8. Structural and sequence analyses reveal specific protein-protein interactions at the binding sites between FCPI and PSI subunits and among FCPI subunits. Structural comparisons of PSI-FCPI supercomplexes and phylogenetic analysis of FCPs between T. pseudonana and the diatom Chaetoceros gracilis unveil the conservation of protein motifs involved in selective bindings of individual FCPI subunits. These find
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Mashup Score: 1Chloroquine attenuates hypoxia-mediated autophagy to curb thrombosis- an ex vivo and in vivo study - 5 hour(s) ago
Background: Hypoxia can trigger the activation of blood platelets, leading to thrombosis. If not addressed clinically, it can cause severe complications and fatal consequences as well. The current treatment regime for thrombosis is often palliative and includes long-term administration of anticoagulants, which has the risk of over-bleeding in injury and other secondary effects as well. This demands a deeper understanding of the process and exploration of an alternative therapeutic avenue. Interestingly, recent studies demonstrate that platelets though atypical and enucleated, possess components of autophagy machinery. This cellular homeostatic process though well-studied in non-platelet cells, is under-explored in platelets. Methods: In this study, we report an activation of autophagy in rat-derived platelets cultured under physiologically relevant hypoxic condition (10% O2) ex vivo. Furthermore, autophagy was triggered in vivo when rats were exposed to hypobaric hypoxic conditions. Su
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Mashup Score: 0
Crossover interference is a phenomenon that affects the number and positioning of crossovers in meiosis and thus affects genetic diversity and chromosome segregation. Yet, the underlying mechanism is not fully understood, partly because quantification is difficult. To overcome this challenge, we introduce the interference length that quantifies changes in crossover patterning due to interference. We show that it faithfully captures known aspects of crossover interference and provides superior statistical power over previous methods. We apply our analysis to empirical data and unveil a similar behavior of the interference length across species, which hints at a common mechanism. A recently proposed coarsening model generally captures these aspects, providing a unified view of crossover interference. Consequently, the interference length facilitates model refinements and general comparisons between alternative models of crossover interference. ### Competing Interest Statement The authors
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Mashup Score: 1Quantifying competition between two demersal fish species from spatiotemporal stomach content data - 5 hour(s) ago
Competition is challenging to quantify in natural systems and inference is often made on indirect patterns of potential competition, such as trends in population trajectories and overlap in spatiotemporal distribution and resource use. However, these indicators are not direct measures of fitness, nor do they say if the contested resource is limited in supply, which are key features of competition. Here we combine stomach content and biomass density data from scientific bottom trawl surveys to evaluate if competition is occurring between two dominant demersal fish species in the southern Baltic Sea: Atlantic cod (Gadus morhua) and flounder (Platichthys spp.). We use multivariate generalized linear latent variable models (GLLVMs) to quantify diet similarities across the domain, diet overlap indices on relatively small spatial scales to test if predator density drives diet overlap, and spatiotemporal GLMMs fit to prey weights in individual predators to evaluate the effects of local biotic
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Mashup Score: 1
Fluvial ecosystems are vital for biodiversity and human welfare but face increasing threats from flow intermittency caused by climate change and other human activities. To better understand drivers of flow intermittency, we analyzed long-term and spatially explicit river drying data from the Rio Grande, a regulated river in the North American desert southwest that was historically perennial but is now persistently intermittent. We examined the spatial structure and influences of precipitation, temperature, in-channel infrastructure, and river discharge on flow intermittency using multivariate autoregressive state space (MARSS) models and 12 years of daily data. Our findings indicate that river diversion rates at dams and irrigation return flows significantly structure the spatial occurrence of flow intermittency, but factors (possibly geologic) at distances less than or equal to 7 kilometers (km) are more influential as predictors of drying. Controlling influences of temperature and pr
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Mashup Score: 0Pharmaco-resistant temporal lobe epilepsy gradually perturbs the cortex-wide excitation-inhibition balance - 5 hour(s) ago
Excitation-inhibition (E/I) imbalance is theorized as a key mechanism in the pathophysiology of epilepsy, with a mounting body of previous research focusing on elucidating its cellular manifestations. However, there are limited studies into E/I imbalance at macroscale and its microcircuit-level mechanisms and clinical associations. In our current work, we computed the Hurst exponent—a previously validated index of the E/I ratio—from resting-state fMRI time series, and simulated microcircuit parameters using biophysical computational models. We found a broad reduction in the Hurst exponent in pharmaco-resistant temporal lobe epilepsy (TLE), indicative of a shift towards more excitable network dynamics. Connectome decoders pointed to temporolimbic and frontocentral areas as plausible network epicenters of E/I imbalance. Computational simulations further revealed that enhancing cortical excitability in patients likely reflected atypical increases in recurrent connection strength of local
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Mashup Score: 0Single-nucleus and spatial transcriptomic profiling of human temporal cortex and white matter reveals novel associations with AD pathology - 5 hour(s) ago
Alzheimer’s disease (AD) is a neurodegenerative disorder with complex pathological manifestations and is the leading cause of cognitive decline and dementia in elderly individuals. A major goal in AD research is to identify new therapeutic pathways by studying the molecular and cellular changes in the disease, either downstream or upstream of the pathological hallmarks. In this study, we present a comprehensive investigation of cellular heterogeneity from the temporal cortex region of 40 individuals, comprising healthy donors and individuals with differing tau and amyloid burden. Using single-nucleus transcriptome analysis of 430,271 nuclei from both gray and white matter of these individuals, we identified cell type-specific subclusters in both neuronal and glial cell types with varying degrees of association with AD pathology. In particular, these associations are present in layer specific glutamatergic (excitatory) neuronal types, along with GABAergic (inhibitory) neurons and glial
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Mashup Score: 0Noise Stress induces Cardiovascular Metabolic Shifts - 6 hour(s) ago
Environmental stressors present in the modern world can fundamentally affect humans’ physiology and health. Exposure to stressors like air pollution, heat, and traffic noise has been linked to a pronounced increase in non-communicable diseases. Specifically, aircraft noise has been identified as a risk factor for cardiovascular and metabolic diseases, such as arteriosclerosis, heart failure, stroke, and diabetes. Noise stress leads to neuronal activation with subsequent stress hormone release that ultimately leads to activation of the renin-angiotensin-aldosterone system, increasing inflammation and oxidative stress, dramatically affecting the cardiovascular system. However, despite the epidemiological evidence of a link between noise stress and metabolic dysfunction, the consequences of exposure at the molecular, metabolic level of the cardiovascular system are largely unknown. Here we use a murine model system of aircraft noise exposure to show that noise stress profoundly alters hea
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Mashup Score: 0Three pollen QTLs are sufficient to partially break stylar unilateral incompatibility of Solanum pennellii - 6 hour(s) ago
In tomato clade, both self-incompatibility(S-) locus-dependent and -independent mechanisms are present in unilateral incompatibility (UI). Several stylar UI factors mediating S-locus-independent mechanism have been gradually uncovered, however, related pollen UI (pui) factors still await more studies.Quantitative trait loci (QTL) mapping, comparative transcriptomics and introgression lines (ILs) /inbred backcross lines (BILs)-based functional analysis were applied for identification and functional validation of pui QTLs between self-compatible (SC) Solanum lycopersicum and SC S. pennellii LA0716.In addition to the reported pui10.1 (SpFPS2), two pui QTLs (pui6.2 and pui12.1) were identified. Pollen tubes of cultivated tomatoes introgressed with three pui loci could partially break the stylar UI response in LA0716 styles. Furthermore, a conserved function of pui12.1 was found in the styles of SC S. habrochaites LA0407 and SC S. chmielewskii LA1028. Three candidate genes linked to pui6.2
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Here's what we know about the KP.2 FLiRT variant that is destined to become the new dominant variant here Thanks to @SystemsVirology https://t.co/RvQjX2dOCA >3-fold resistance to current booster (XBB.1.5) https://t.co/UEnte4LZAI https://t.co/n1oULGNZYX