Effect of Different Landing Heights and Loads on Ankle Inversion Proprioception during Landing in Individuals with and without Chronic Ankle Instability.

Proprioception is essential for neuromuscular control in relation to sport injury and performance. The effect of landing heights and loads on ankle inversion proprioceptive performance in individuals with or without chronic ankle instability (CAI) may be important but are still unclear. Forty-three participants (21 CAI and 22 non-CAI) volunteered for this study. The Ankle Inversion Discrimination Apparatus for Landing (AIDAL), with one foot landing on a horizontal surface and the test foot landing on an angled surface (10°, 12°, 14°, 16°), was utilized to assess ankle proprioception during landing. All participants performed the task from a landing height of 10 cm and 20 cm with 100% and 110% body weight loading. The four testing conditions were randomized. A repeated measures ANOVA was used for data analysis. The result showed that individuals with CAI performed significantly worse across the four testing conditions (p = 0.018). In addition, an increased landing height (p = 0.010), not loading (p > 0.05), significantly impaired ankle inversion discrimination sensitivity. In conclusion, compared to non-CAI, individuals with CAI showed significantly worse ankle inversion proprioceptive performance during landing. An increased landing height, not loading, resulted in decreased ankle proprioceptive sensitivity. These findings suggest that landing from a higher platform may increase the uncertainty of judging ankle positions in space, which may increase the risk of ankle injury.

Engineered Spore-Forming Bacillus as a Microbial Vessel for Long-Term DNA Data Storage.

DNA data storage technology may supersede conventional chip or magnetic data storage medium, providing long-term stability, high density, and sustainable storage. Due to its error-correcting capability, DNA data stored in living organisms exhibits high fidelity in information replication. Here we report the development of a Bacillus chassis integrated with an inducible artificially assembled bacterial chromosome to facilitate random data access. We generated three sets of data in the form of DNA sequences using a rudimentary coding system accessible by the regulatory promoter. Sporulated Bacillus harboring the genes were used for long-term storage, where viability assays of spores were subjected to harsh environmental stresses to evaluate the data storage stability. The data accuracy remained above 99% after high temperature and oxidative stress treatment, whereas UV irradiation treatment provided above 96% accuracy. The developed Bacillus chassis and artificial chromosome facilitate the long-term storage of larger datum volume by using other DNA digital encoding and decoding programs.

An Intelligent Multi-View Active Learning Method Based on a Double-Branch Network.

Artificial intelligence is one of the most popular topics in computer science. Convolutional neural network (CNN), which is an important artificial intelligence deep learning model, has been widely used in many fields. However, training a CNN requires a large amount of labeled data to achieve a good performance but labeling data is a time-consuming and laborious work. Since active learning can effectively reduce the labeling effort, we propose a new intelligent active learning method for deep learning, which is called multi-view active learning based on double-branch network (MALDB). Different from most existing active learning methods, our proposed MALDB first integrates two Bayesian convolutional neural networks (BCNNs) with different structures as two branches of a classifier to learn the effective features for each sample. Then, MALDB performs data analysis on unlabeled dataset and queries the useful unlabeled samples based on different characteristics of two branches to iteratively expand the training dataset and improve the performance of classifier. Finally, MALDB combines multiple level information from multiple hidden layers of BCNNs to further improve the stability of sample selection. The experiments are conducted on five extensively used datasets, Fashion-MNIST, Cifar-10, SVHN, Scene-15 and UIUC-Sports, the experimental results demonstrate the validity of our proposed MALDB.

Radiation properties of quantum emitters via a plasmonic waveguide integrated with a V-shaped traveling wave antenna.

We experimentally study the radiation direction and relaxation rate of quantum emitters (QEs) coupled with a plasmonic waveguide integrated with a V-shaped traveling wave antenna. The plasmonic waveguide couples the excitation energy of the nearby QEs into surface plasmons and the connected V-shaped traveling wave antenna converts them into highly directional radiation. The directivity of the radiation depends on the shape of the antenna. The half-power beam widths of the radiation with respect to the azimuthal and polar angles are as small as 15.1° and 13.1°, respectively, when the antenna has a 144° intersection angle. The relaxation rates of the QEs are enhanced up to 33.04 times relative to the intrinsic emission rate. The method to control the fluorescence of QEs is of great significance for optical devices, nanoscale light sources, and integrated optics.

Nanoscale Refractive Index Sensors with High Figures of Merit via Optical Slot Antennas.

Nanoscale refractive index (RI) sensors based on a single nanorod or nanoantenna typically suffer from a low figure of merit (FOM) due to the large full width at half-maximum of the plasmonic dipole resonance. Here, we demonstrate nanosensors with a high FOM and a sensing volume that is much smaller than λ3 using slot antennas. Two configurations, one based on a bowtie slot antenna (BSA) and one based on a slot antenna pair (SAP), are proposed. The RI information is obtained from the extinction dip that is due to the interference of surface plasmon polaritons (SPPs), which are launched at different nodes of a third-order resonant mode of the BSA or different antennas of the SAP. The high FOM is attributed to the dependence of the extinction spectrum on both the amplitude and the phase of the SPPs. There are important applications for these nanosensors, which can measure the local RI beyond the diffraction limit and can be flexibly integrated.

Microcystin-LR influences the in vitro oocyte maturation of zebrafish by activating the MAPK pathway.

Harmful cyanobacteria and their production of microcystins (MCs) exert significant toxicity on reproduction of fish, especially the process of oogenesis. Our previous studies demonstrated that MCs have negative impacts on the quantity and quality of mature oocytes in female zebrafish. However, the underlying mechanisms of MCs disrupting oocyte maturation (OM) have been rarely reported. In the present study, in vitro oocytes (immature) were separated from zebrafish and treated with 1, 10, 100 µg/L MC-LR. The serine/threonine protein phosphatase 2A (PP2A) activity was downregulated significantly in oocytes exposed to 10 and 100 µg/L MC-LR for both 2 and 4 h. The phosphorylation levels of mitogen-activated protein kinase (MAPK) were detected without noticeable change in all oocytes treated with MC-LR for 2 h, whereas the activated levels of MAPK subtypes (ERK, p38 and JNK) increased remarkably in the 100 µg/L MC-LR treatment of 4 h. In the oocytes exposed to 100 µg/L MC-LR for 4 h, germinal vesicle breakdown (GVBD) rates changed abnormally and maturation-promoting factor (MPF) activity increased significantly, in accordance with the upregulation of Cyclin B protein levels. Moreover, the MAPK inhibitors (10 µM) were applied to explore the role of MAPK subtypes during MC-LR influencing OM and results showed that ERK inhibitor U0126 and p38 inhibitor SB203580 mitigated the effects of 100 µg/L MC-LR-induced MAPK hyper-phosphorylation and elevated GVBD in the oocytes. In conclusion, the present study indicates that microcystins disrupt the meiotic maturation by the pathway of MC-PP2A-MAPK-OM due to the phosphorylation disorder in oocytes.

Recovery of reproductive function of female zebrafish from the toxic effects of microcystin-LR exposure.

Fish has a strong resistance to microcystins (MCs), cyclic heptapeptide cyanotoxins, known as endocrine disrupting chemicals (EDCs) which are released during cyanobacterial blooms and many laboratory and field studies have found the hepatic recovery of fish from the MCs exposure. The aim of the present study was to investigate the recovery mechanisms of reproductive function of adult zebrafish (Danio rerio) from microcystin-LR (MC-LR) exposure. Therefore, adult female zebrafish were exposed to 0, 1 or 50 µg/L of MC-LR for 21days and transferred to MC free water for another 21 days to investigate the recovery. After MC-LR exposure, marked histological lesions in the gonads, decreased the percentage of mature oocytes, decreased number of spawned eggs, decreased fertilization and hatching rates were observed. MC-LR exposure increased the concentration of 17ß-estradiol (E2), testosterone (T) and vitellogenin (VTG) in female zebrafish. Some gene transcriptions of the hypothalamic-pituitary-gonad (HPG) axis significantly changed. The protein levels of 17ßhsd and cyp19a remarkably increased in the MC-LR exposure groups. However, our laboratory observation also indicates that zebrafish transferred from microcystin exposure to toxin-free water and reared for 21 days exhibited a nearly complete recovery of reproductive functions, including histological structure, increased the percentage of matured oocytes and spawned eggs, stable hormone levels, well-balanced transcriptional and translational levels. These results indicate that after MC-LR exposure, the reproductive impairments in zebrafish are also reversible likewise hepatic recovery seen by different studies in fish. Future studies should be conducted to explore a better understanding of the recovery mechanisms of fish from microcystins exposure.

µEvaluation of microcystin-LR absorption using an in vivo intestine model and its effect on zebrafish intestine.

Microcystin-LR (MC-LR) is regarded as one of the most toxic microcystins (MCs) isoforms. Microcystins could cause multiple organs dysfunction, and more attention has been drawn to the toxic effects on the gastrointestinal disorder. By using ex vivo everted gut sac model in 6 fish (Carassius auratus, Megalobrama amblycephala, Hypophthalmichthys molitrix, Aristichthys nobilis, Ctenopharyngodon idellus and Cyprinus carpio) and determining the accumulation of MC-LR in zebrafish intestine, we found a dose-dependent manner in the absorption and accumulation of MC-LR. Until now, little studies have been reported concerning the gut microbiota composition caused by different MC-LR exposure. The present study is the first time characterized the phylogenetic composition and taxonomic of the bacterial communities growth in the intestines of zebrafish treated with MC-LR using 16S rRNA pyrosequencing. After 30 days of treatment with 0, 1, 5 or 20 µg/L MC-LR, the alpha and beta diversity did not generate significant differences, indicating the existence of a core microbiota. However, db-RDA analysis showed that treatment with 20 µg/L MC-LR changed the characteristics of high abundances microbiota. The expression of Oatp2b1, stress related enzyme activities in gut and their associations with gut microbiota were also determined. The identified phylotypes including Actinobacteria, Lactobacillus and some opportunistic pathogens highlight the increasing risks of pathogen invasion and recovery tendency via potential probiotics resistance in zebrafish exposed to MC-LR.

Explorations of the optimal method for isolating oocytes from zebrafish (Danio rerio) ovary.

Obtaining oocytes from the adult female zebrafish (Danio rerio) ovary has enormous importance in the studies of developmental biology, toxicology, and genetics. It is vital to establish a simple and effective approach to ensure the quantity and quality of oocytes, which will enable the success of follow-up experimental investigation finally. Usually, oocytes are separated with mechanical or enzymatic methods, however, little studies have been done with concerns about the comparative effects. The present study separated zebrafish oocytes of Stage III with five frequently used methods, including stripping, pipetting, hyaluronidase (1.6 mg/ml), collagenase (0.4 mg/ml), and trypsin (0.1%). The cell viability, oxidative stress, mitogen-activated protein kinase (MAPK) protein phosphorylation, and apoptosis levels were selected as main biomarkers to evaluate the oocytes health status. The results showed that both trypsin and hyaluronidase isolation significantly upregulated germinal vesicle breakdown (GVBD) rates and downregulated p38 MAPK activity simultaneously. GVBD rates and survival rates were decreased notably in oocytes separated by the collagenase method. Above results indicate that zebrafish oocytes in vitro are sensitive to enzymatic treatments and the enzymatic isolation is not the suitable mean for collecting zebrafish oocytes although it is time-saving. The mechanical strategy of pipetting remarkably increased the reactive oxygen species and malondialdehyde level in isolated oocytes. Interestingly, oocytes separated with stripping show less physiological and biochemical damages. Therefore, stripping isolation is comparatively recommended as the optimum method for separating and collecting numerous intact and healthy zebrafish oocytes in vitro for the subsequent developmental research.