Strong law of large numbers for the generalized Fr\'{e}chet means with random minimizing domains

This paper introduces a novel extension of Fr\'{e}chet means, called \textit{generalized Fr\'{e}chet means} as a comprehensive framework for characterizing features in probability distributions in general topological spaces. The generalized Fr\'{e}chet means are defined as minimizers of a suitably defined cost function. The framework encompasses various extensions of Fr\'{e}chet means in the literature. The most distinctive difference of the new framework from the previous works is that we allow the domain of minimization of the empirical means be random and different from that of the population means. This expands the applicability of the Fr\'{e}chet mean framework to diverse statistical scenarios, including dimension reduction for manifold-valued data

Oscillatory spin-orbit torque switching induced by field-like torques

Deterministic magnetization switching using spin-orbit torque (SOT) has recently emerged as an efficient means to electrically control the magnetic state of ultrathin magnets. The SOT switching still lacks in oscillatory switching characteristics over time, therefore, it is limited to bipolar operation where a change in polarity of the applied current or field is required for bistable switching. The coherent rotation based oscillatory switching schemes cannot be applied to SOT because the SOT switching occurs through expansion of magnetic domains. Here, we experimentally achieve oscillatory switching in incoherent SOT process by controlling domain wall dynamics. We find that a large field-like component can dynamically influence the domain wall chirality which determines the direction of SOT switching. Consequently, under nanosecond current pulses, the magnetization switches alternatively between the two stable states. By utilizing this oscillatory switching behavior we demonstrate a unipolar deterministic SOT switching scheme by controlling the current pulse duration

Sepsis-Like Systemic Inflammation Induced by Nano-Sized Extracellular Vesicles From Feces

Nano-sized extracellular vesicles (EVs), including exosomes, microvesicles, and other types of vesicles, are released by most mammalian cells and bacteria. We here ask whether feces contain EVs of mammalian and/or bacterial origin, and whether these EVs induce systemic inflammation. Fecal extracellular vesicles (fEVs) were isolated from mice and humans. The presence of EVs from Gram-negative and Gram-positive bacteria was detected by enzyme-linked immunosorbent assay using anti-lipid A and anti-lipoteichoic acid antibodies, whereas Western blot using anti-beta-actin antibody was employed to detect host-derived EVs in the fEVs. Further, fEVs were administered into mice by intraperitoneal injection, and inflammatory responses were investigated in the peritoneum, blood, and lungs. The role of TLR2 and TLR4 were studied using knockout mice. Significant quantities of EVs were present in feces from mice as well as humans, and derived from Gram-negative and Gram-positive bacteria, as well as the host. Bacteria-free fEVs introduced into the peritoneum induced local and systemic inflammation (including in the lungs), but fEVs from germ-free animals had weaker effects. This pronounced local and systemic inflammatory responses seemed to be induced by EVs from both Gram-negative and Gram-positive bacteria, and was attenuated in mice lacking TLR2 or TLR4. Our findings show that fEVs cause sepsis-like systemic inflammation, when introduced intraperitoneally, a process regulated by TLR2 and TLR4.11Ysciescopu

Potential effects of sediment processes on water quality of an artificial reservoir in the Asian monsoon region

Sediment processes in lakes may affect water chemistry through the internal loading of phosphorus, ammonia, and sulfides released under anoxic conditions. Lake Soyang is a deep warm monomictic reservoir with a dendritic shape, located in the Asian summer monsoon region, South Korea. During summer, the lake is stratified and receives a large nutrient input via storm runoff, which forms a turbid intermediate layer with high concentrations of suspended particles. The lake water, the main inflowing stream (the Soyang River), bottom sediment, and porewater of the lake sediments were studied over a 2-year period (2012–2013). After intensive monsoon rain events, particulate organic carbon (POC), total phosphorus (TP), and turbidity were high in the inflowing water (C: 1.21 mg L−1 in June 2013) and in the metalimnion (2.8 mg L−1, 17.6 μg L−1, and 58.5 NTU, respectively in July 2013). Higher concentrations of iron (Fe) and manganese (Mn) were also associated with the turbid intermediate layer (37 and 8 μg L−1, respectively, in July 2013). During the summer stratification period, oxygen started to deplete in the hypoliminion (down to 0.5 mg L−1 in September 2013), and sediment became anoxic, showing negative oxidation redox potential (ORP) in core samples. Diffusion of dissolved inorganic P and ammonia from sediment to the water column can be substantial, considering the concentration difference between the porewater and hypolimnetic water. Fe and Mn were abundant in the sediment porewater at the dam site, implying inorganic nutrients and minerals are well transported along the 60 km long lake axis by the density current of storm runoff. Sulfate and reduced sulfur were larger in the porewater of the top sediment than in the lower layer of the sediment core (below 10 cm). The results show that substantial amounts of inorganic nutrients and minerals are supplied to the lake by storm runoffs during monsoon and distributed through the lake by a density current, controlling the material cycle and flux at the sediment surface

Peptidyl-prolyl cis/trans isomerase Pin1 interacts with hepatitis B virus core particle, but not with HBc protein, to promote HBV replication

Here, we demonstrate that the peptidyl-prolyl cis/trans isomerase Pin1 interacts noncovalently with the hepatitis B virus (HBV) core particle through phosphorylated serine/threonine-proline (pS/TP) motifs in the carboxyl-terminal domain (CTD) but not with particle-defective, dimer-positive mutants of HBc. This suggests that neither dimers nor monomers of HBc are Pin1-binding partners. The 162TP, 164SP, and 172SP motifs within the HBc CTD are important for the Pin1/core particle interaction. Although Pin1 dissociated from core particle upon heat treatment, it was detected as an opened-up core particle, demonstrating that Pin1 binds both to the outside and the inside of the core particle. Although the amino-terminal domain S/TP motifs of HBc are not involved in the interaction, 49SP contributes to core particle stability, and 128TP might be involved in core particle assembly, as shown by the decreased core particle level of S49A mutant through repeated freeze and thaw and low-level assembly of the T128A mutant, respectively. Overexpression of Pin1 increased core particle stability through their interactions, HBV DNA synthesis, and virion secretion without concomitant increases in HBV RNA levels, indicating that Pin1 may be involved in core particle assembly and maturation, thereby promoting the later stages of the HBV life cycle. By contrast, parvulin inhibitors and PIN1 knockdown reduced HBV replication. Since more Pin1 proteins bound to immature core particles than to mature core particles, the interaction appears to depend on the stage of virus replication. Taken together, the data suggest that physical association between Pin1 and phosphorylated core particles may induce structural alterations through isomerization by Pin1, induce dephosphorylation by unidentified host phosphatases, and promote completion of virus life cycle

The effects of Asian summer monsoon on algal blooms in reservoirs

An important characteristic of lakes and reservoirs in the East Asian summer monsoon region is the dramatic seasonal difference in hydrologic inputs, with annual rainfall commonly concentrated in a few heavy rain events. In this study, we surveyed the monthly variations of phytoplankton density in 3 large deep reservoirs and 7 small shallow reservoirs and analyzed the effect of large precipitation events on phytoplankton. During heavy rains, stream phosphorus concen¬trations increased sharply, and phosphorus loadings into reservoirs were not continuous but episodic shock loadings. In deep stratified reservoirs, however, the concentrations of phosphorus and chlorophyll a were much lower than expected from the high total phosphorus levels in the storm runoff. Inflowing storm waters laden with phosphorus flowed into metalimnetic layers because deep reservoirs had strong thermal stratification and the storm water was cooler than the epilimnion. The result was the formation of an ecosystem resilient to phosphorus shock loadings during monsoon. Nutrients in the metalimnion seemed to be dispersed gradually toward the epilimnion, and phytoplankton reached maximum densities, called “monsoon blooms,” after the monsoon. By contrast, shallow reservoirs with short hydraulic residence times had lower chlorophyll a concentrations during the monsoon season because the high flushing rate was the major limiting factor of phytoplankton growth. In conclusion, summer monsoon is the major determinant of phyto¬plankton density in reservoirs of the East Asian region, but their responses can vary widely depending on hydrologic characteristics

Navigation-assisted anchor insertion in shoulder arthroscopy: a validity study

Background: This study aimed to compare conventional and navigation-assisted arthroscopic rotator cuff repair in terms of anchor screw insertion. Methods: The surgical performance of five operators while using the conventional and proposed navigation-assisted systems in a phantom surgical model and cadaveric shoulders were compared. The participating operators were divided into two groups, the expert group (n = 3) and the novice group (n = 2). In the phantom model, the experimental tasks included anchor insertion in the rotator cuff footprint and sutures retrieval. A motion analysis camera system was used to track the surgeons’ hand movements. The surgical performance metric included the total path length, number of movements, and surgical duration. In cadaveric experiments, the repeatability and reproducibility of the anchor insertion angle were compared among the three experts, and the feasibility of the navigation-assisted anchor insertion was validated. Results: No significant differences in the total path length, number of movements, and time taken were found between the conventional and proposed systems in the phantom model. In cadaveric experiments, however, the clustering of the anchor insertion angle indicated that the proposed system enabled both novice and expert operators to reproducibly insert the anchor with an angle close to the predetermined target angle, resulting in an angle error of < 2° (P = 0.0002). Conclusion: The proposed navigation-assisted system improved the surgical performance from a novice level to an expert level. All the experts achieved high repeatability and reproducibility for anchor insertion. The navigation-assisted system may help surgeons, including those who are inexperienced, easily familiarize themselves to of suture anchors insertion in the right direction by providing better guidance for anchor orientation. Level of evidence: A retrospective study (level 2). © 2020, The Author(s).1