Improvement of roughness in ultrasonic assisted magnetorheological finishing of small titanium alloy nuts by orthogonal test method.

Titanium alloy with high corrosion resistance, high strength-to-density ratio, and excellent biocompatibility has a wide range of applications in the field of biomedical implants. Polishing experiments of titanium alloy with a small size and complex shapes were investigated using an ultrasonic assisted magnetorheological finishing (UMRF) device excited by a three-pole magnetic field generator. The models of the normal force and the shear force were first proposed based on the Preston equation to analyze the mechanism of material removal in the UMRF process. Subsequently, the single-factor experiments using titanium alloy nuts (M3) and the MR polishing fluid with silicon carbide abrasives were carried out. Furthermore, to improve the surface roughness and the change rate of surface roughness of nuts, orthogonal tests with a standard L9(34) orthogonal array were designed and performed based on the optimized process parameters obtained from the single-factor experiment. The results indicated the effect on surface roughness and change rate of surface roughness as applied current > roller speed > ultrasonic amplitude > spindle speed and applied current > roller speed > spindle speed > ultrasonic amplitude, respectively. Moreover, the surface roughness was improved from an initial 1.247 µm to a final 0.104 µm after the polishing for 80 min under these optimal process parameters.

Evolutionary analysis and biological characterization of a novel alphabaculovirus isolated from Mythimna separata.

Baculoviruses are insect-specific pathogens. Novel baculovirus isolates provide new options for the biological control of pests. Therefore, research into the biological characteristics of newly isolated baculoviruses, including accurate classification and nomenclature, is important. In this study, a baculovirus was isolated from Mythimna separata and its complete genome sequence was determined by next-generation sequencing. The double-stranded DNA genome was 153 882 bp in length, encoding 163 open reading frames. The virus was identified as a variant of Mamestra brassicae multiple nucleopolyhedrovirus (MbMNPV) and designated Mamestra brassicae multiple nucleopolyhedrovirus CHN1 (MbMNPV-CHN1) according to ultrastructural analysis, genome comparison and phylogenetic analysis. Phylogenetic inference placed MbMNPV-CHN1 in a clade containing isolates of MacoNPV-A, MacoNPV-B and MbMNPV, which we have designated the Mb-McNPV group. The genomes of isolates in the Mb-McNPV group exhibited a high degree of collinearity with relatively minor differences in the content of annotated open reading frames. The development of codon usage bias in the Mb-McNPV group was affected mainly by natural selection. MbMNPV-CHN1 shows high infectivity against seven species of Lepidoptera. The yield of MbMNPV-CHN1 in the fourth- and fifth-instar M. separata larvae was 6.25×109-1.23×1010 OBs/cadaver. Our data provide insights into the classification, host range and virulence differences among baculoviruses of the Mb-McNPV group, as well as a promising potential new baculoviral insecticide.

Improved effects of Helicoverpa armigera nucleopolyhedrovirus integrated with Campoletis chlorideae against H. armigera and impact of the virus on the parasitoid.

BACKGROUND: Combined use can be an effective measure to improve pest control by viruses and parasitic wasps. However, not all combinations of natural enemies show improved effects. Helicoverpa armigera nucleopolyhedrovirus (HearNPV) and Campoletis chlorideae Uchida are two important natural enemies of Helicoverpa armigera. This study aimed to investigate the combined effects of C. chlorideae and HearNPV against H. armigera larvae and the impact of HearNPV on C. chlorideae. RESULTS: The combination of HearNPV and C. chlorideae exerted increased mortality on H. armigera when C. chlorideae parasitized larvae one day after infection with HearNPV. C. chlorideae could distinguish between HearNPV-infected and noninfected larvae. Besides influencing host selection of C. chlorideae, HearNPV infection had negative effects on the development and reproduction of C. chlorideae. The developmental time of C. chlorideae was significantly prolonged and the percentage of emergence and adult eclosion of C. chlorideae was lower in infected hosts. The adult wasps were also smaller in body size, and female adults had fewer eggs when they developed in virus-infected hosts. CONCLUSIONS: HearNPV combined with C. chlorideae could improve the efficacy of biological control against H. armigera. The results provided valuable information on the importance of timing in the combined use of HearNPV and C. chlorideae for the biological control of H. armigera. © 2023 Society of Chemical Industry.

Dietary Supplementation with Lysozyme-Cinnamaldehyde Conjugates Enhances Feed Conversion Efficiency by Improving Intestinal Health and Modulating the Gut Microbiota in Weaned Piglets Infected with Enterotoxigenic Escherichia coli.

This study aims to evaluate the efficacy of lysozyme-cinnamaldehyde conjugates (LC) as a potential alternative to antibiotics in treating piglets infected with enterotoxigenic Escherichia coli (ETEC). The results demonstrated that piglets fed with the LC diet exhibited lower rectal temperature and fecal scores at 9 h, 24 h, and 48 h post-ETEC challenge. Furthermore, LC supplementation led to significant improvements in the mechanical and immune barriers of the jejunum and ileum, as indicated by an increased villi-height-to-crypt-depth ratio (VCR) and the expression of tight junction proteins, mucin, and ß-defensins. Furthermore, the LC diet lowered the levels of pro-inflammatory cytokines TNF-α and IL-1ß in the plasma. Further analyses showed that the LC diet downregulated genes (specifically TLR4 and MyD88) linked to the TLRs/MyD88/NF-κB signaling pathway in the small intestine. Additionally, 16SrDNA sequencing data revealed that LC supplementation increased the α diversity of intestinal microorganisms and the relative abundance of Lactobacillus. In summary, the LC-supplemented diet effectively mitigated the adverse effects of E. coli K88, including intestinal barrier damage and inflammation. Furthermore, it improved the structure of the intestinal flora, ultimately contributing to better growth performance in piglets.

Creating Age-Friendly Environments in a Smart Society in China: A Policy Review.

Technology is increasingly being integrated into Age-Friendly Environments (AFEs). This study explores how technology is manifested in AFE policies in China. We conducted a content analysis of 176 policies spanning seven years to identify the relationship between technology and AFEs and the characteristics of policy development. The findings indicate that technology plays a role in advancing a smart age-friendly society, particularly in terms of enhancing community support and health services and promoting social inclusion. The findings also reveal a list of policy actions and changes in collaborative leadership and strategic priorities throughout policy development. This study emphasizes the need for ongoing policy attention to technology as an integrated component of AFE policies.

Enhancing rice quality and productivity: Multifunctional biochar for arsenic, cadmium, and bacterial control in paddy soil.

The perilousness of arsenic and cadmium (As-Cd) toxicity in water and soil presents a substantial hazard to the ecosystem and human well-being. Additionally, this metal (loids) (MLs) can have a deleterious effect on rice quality and yield, owing to the existence of toxic stress. In response to the pressing concern of reducing the MLs accumulation in rice grain, this study has prepared magnesium-manganese-modified corn-stover biochar (MMCB), magnesium-manganese-modified eggshell char (MMEB), and a combination of both (MMCEB). To test the effectiveness of these amendments, several pot trials were conducted, utilizing 1% and 2% application rates. The research discovered that the MMEB followed by MMCEB treatment at a 2% rate yielded the most significant paddy and rice quality, compared to the untreated control (CON) and MMCB. MMEB and MMCEB also extensively decreased the MLs content in the grain than CON, thereby demonstrating the potential to enrich food security and human healthiness. In addition, MMEB and MMCEB augmented the microbial community configuration in the paddy soil, including As-Cd detoxifying bacteria, and decreased bioavailable form of the MLs in the soil compared to the CON. The amendments also augmented Fe/Mn-plaque which captured a considerable quantity of As-Cd in comparison to the CON. In conclusion, the utilization of multifunctional biochar, such as MMEB and MMCEB, is an encouraging approach to diminish MLs aggregation in rice grain and increase rice yield for the reparation of paddy soils via transforming microbiota especially enhancing As-Cd detoxifying taxa, thereby improving agroecology, food security, and human and animal health.

Artificial intelligence in the diagnosis of dental diseases on panoramic radiographs: a preliminary study.

BACKGROUND: Artificial intelligence (AI) has been introduced to interpret the panoramic radiographs (PRs). The aim of this study was to develop an AI framework to diagnose multiple dental diseases on PRs, and to initially evaluate its performance. METHODS: The AI framework was developed based on 2 deep convolutional neural networks (CNNs), BDU-Net and nnU-Net. 1996 PRs were used for training. Diagnostic evaluation was performed on a separate evaluation dataset including 282 PRs. Sensitivity, specificity, Youden's index, the area under the curve (AUC), and diagnostic time were calculated. Dentists with 3 different levels of seniority (H: high, M: medium, L: low) diagnosed the same evaluation dataset independently. Mann-Whitney U test and Delong test were conducted for statistical analysis (ɑ=0.05). RESULTS: Sensitivity, specificity, and Youden's index of the framework for diagnosing 5 diseases were 0.964, 0.996, 0.960 (impacted teeth), 0.953, 0.998, 0.951 (full crowns), 0.871, 0.999, 0.870 (residual roots), 0.885, 0.994, 0.879 (missing teeth), and 0.554, 0.990, 0.544 (caries), respectively. AUC of the framework for the diseases were 0.980 (95%CI: 0.976-0.983, impacted teeth), 0.975 (95%CI: 0.972-0.978, full crowns), and 0.935 (95%CI: 0.929-0.940, residual roots), 0.939 (95%CI: 0.934-0.944, missing teeth), and 0.772 (95%CI: 0.764-0.781, caries), respectively. AUC of the AI framework was comparable to that of all dentists in diagnosing residual roots (p > 0.05), and its AUC values were similar to (p > 0.05) or better than (p < 0.05) that of M-level dentists for diagnosing 5 diseases. But AUC of the framework was statistically lower than some of H-level dentists for diagnosing impacted teeth, missing teeth, and caries (p < 0.05). The mean diagnostic time of the framework was significantly shorter than that of all dentists (p < 0.001). CONCLUSIONS: The AI framework based on BDU-Net and nnU-Net demonstrated high specificity on diagnosing impacted teeth, full crowns, missing teeth, residual roots, and caries with high efficiency. The clinical feasibility of AI framework was preliminary verified since its performance was similar to or even better than the dentists with 3-10 years of experience. However, the AI framework for caries diagnosis should be improved.

Dental caries status and its associated factors among schoolchildren aged 6-8 years in Hangzhou, China: a cross-sectional study.

BACKGROUND: Dental caries prevalence reaches the first peak around 6 years old. It is necessary to take effective measures to prevent and treat caries at this stage. This study investigated the prevalence and associated factors of dental caries among schoolchildren aged 6-8 years in Hangzhou City, China. METHODS: A cross-sectional survey was conducted in Hangzhou from October 2017 to May 2018. Oral health status of schoolchildren in 1st and 2nd grades of primary schools aged 6-8 years was examined by well-trained examiners according to the WHO criteria. Questionnaires about potential caries-related factors were distributed to their parents. ANOVA test and logistic regression were conducted for the statistical analyses (α = 0.05). RESULTS: A total of 7959 pairs of schoolchildren and their parents were invited to participate, and 5595 were included in this study according to the eligible criteria (response rate: 70.3%). The overall prevalence and mean dmft/DMFT of dental caries in the investigated schoolchildren were 52.78% and 2.11. The prevalence and mean dmft/DMFT were 39.05% and 1.63 in the deciduous teeth, while these were 21.45% and 0.48 in the permanent teeth, respectively. For the first permanent molars (FPMs), the rate of fully eruption and pit and fissure sealing (PFS) were 79.09% and 6.60%, respectively. Multiple logistic regression showed that girl (OR = 1.12, 95% CI 1.01-1.25, p < 0.05), seldom or never brush teeth (OR = 2.36, 95% CI 1.08-5.44, p < 0.05), consuming sweet food or drink once or more time a day (OR = 1.14, 95% CI 1.00-1.29, p < 0.05; OR = 1.21, 95% CI 1.07-1.36, p < 0.05), dental visit experiences (OR = 1.58, 95% CI 1.35-1.86, p < 0.001) were positively and no tooth pain in the past 12 months (OR = 0.55, 95% CI 0.38-0.80, p < 0.05) were negatively associated with caries. CONCLUSIONS: Dental caries was prevalent among schoolchildren aged 6-8 years in Hangzhou, and was associated with gender, frequency of toothbrushing, sweet food or drink consuming, tooth pain and dental visit experiences. A large number of fully erupted FPMs did not receive timely PFS.

The Associations Between Alanine Aminotransferase and Other Biochemical Parameters in Lean PCOS.

To explore the associations of alanine aminotransferase in lean women of polycystic ovary syndrome (PCOS) with other biochemical parameters and the potential risk factors. This is a retrospective cohort study with lean PCOS (n = 91) and healthy controls (n = 45); we reviewed the electrical records and databases of the PCOS patients in our infertility clinic between January 2019 and September 2021; independent t-test, linear correlation analysis, and multiple linear regression were used to explore the associations. Higher levels of luteinizing hormone, total testosterone, thyroid stimulating hormone, platelet count, lymphocyte count, homocysteine, alanine aminotransferase (ALT), and uric acid were identified in lean PCOS patients, while follicle-stimulating hormone level was lower in in lean PCOS as expected (P < 0.05). Of note, the linear correlation showed that BMI, total testosterone, white blood cell count, lymphocyte count, aspartate aminotransferase, and uric acid were positively associated with alanine aminotransferase (r = 0.232, 0.318, 0.218, 0.388, 0.602, 0.353 respectively, P < 0.05). After multiple linear regression was performed, total testosterone and aspartate aminotransferase were independently and positively correlated with alanine aminotransferase in lean PCOS (B = 0.251, 0.605 respectively, P < 0.05). Higher level of ALT was identified in the lean PCOS. BMI, white blood cell count, lymphocyte count, aspartate aminotransferase, uric acid, and total testosterone were positively correlated with ALT in lean PCOS. Total testosterone and aspartate aminotransferase were independently and positively associated with ALT in lean PCOS after multiple linear regression. There might exist a potential risk of afflicting liver impairment for the lean PCOS women in the earlier period. Early examination and intervention might be necessary to prevent or delay the progression of the liver disease as soon as the diagnosis of PCOS.

Chemically mediated rheotaxis of endangered tri-spine horseshoe crab: potential dispersing mechanism to vegetated nursery habitats along the coast.

Background: An enhanced understanding of larval ecology is fundamental to improve the management of locally depleted horseshoe crab populations in Asia. Recent studies in the northern Beibu Gulf, China demonstrated that nesting sites of Asian horseshoe crabs are typically close to their nursery beaches with high-density juveniles distributed around mangrove, seagrass and other structured habitats. Methods: A laboratory Y-maze chamber was used to test whether the dispersal of early-stage juvenile tri-spine horseshoe crab Tachypleus tridentatus is facilitated by chemical cues to approach suitable nursery habitats. The juvenile orientation to either side of the chamber containing controlled seawater or another with various vegetation cues, as well as their movement time, the largest distance and displacement were recorded. Results: The juveniles preferred to orient toward seagrass Halophila beccarii cues when the concentration reached 0.5 g l-1, but ceased at 2 g l-1. The results can be interpreted as a shelter-seeking process to get closer to the preferred settlement habitats. However, the juveniles exhibited avoidance behaviors in the presence of mangrove Avicennia marina and invasive saltmarsh cordgrass Spartina alterniflora at 2 g l-1. The juveniles also spent less time moving in the presence of the A. marina cue, as well as reduced displacement in water containing the S. alterniflora cue at 1 and 2 g l-1. These results may explain the absence of juvenile T. tridentatus within densely vegetated areas, which have generally higher organic matter and hydrogen sulfide. Conclusion: Early-stage juvenile T. tridentatus are capable of detecting and responding to habitat chemical cues, which can help guide them to high-quality settlement habitats. Preserving and restoring seagrass beds in the intertidal areas should be prioritized when formulating habitat conservation and management initiatives for the declining horseshoe crab populations.

AI ethics with Chinese characteristics? Concerns and preferred solutions in Chinese academia.

Since Chinese scholars are playing an increasingly important role in shaping the national landscape of discussion on AI ethics, understanding their ethical concerns and preferred solutions is essential for global cooperation on governance of AI. This article, therefore, provides the first elaborated analysis on the discourse on AI ethics in Chinese academia, via a systematic literature review. This article has three main objectives. (1) to identify the most discussed ethical issues of AI in Chinese academia and those being left out (the question of "what"); (2) to analyze the solutions proposed and preferred by Chinese scholars (the question of "how"); and (3) to map out whose voices are dominating and whose are in the marginal (the question of "who"). Findings suggest that in terms of short-term implications, Chinese scholars' concerns over AI resemble predominantly the content of international ethical guidelines. Yet in terms of long-term implications, there are some significant differences needed to be further addressed in a cultural context. Further, among a wide range of solution proposals, Chinese scholars seem to prefer strong-binding regulations to those weak ethical guidelines. In addition, this article also found that the Chinese academic discourse was dominated by male scholars and those who are from elite universities, which arguably is not a unique phenomenon in China. Supplementary Information: The online version contains supplementary material available at 10.1007/s00146-022-01578-w.

Tetrodotoxin in Asian horseshoe crabs Carcinoscorpius rotundicauda and Tachypleus tridentatus across different life stages from northern Beibu Gulf, China.

Horseshoe crabs (HSCs) are a group of ancient chelicerates with great ecological and biomedical importance. Food poisonings caused by the consumption of Asian HSCs have significant impacts on public health and safety. This study measured tetrodotoxin (TTX) concentrations in two HSC species across various life stages in May 2020 from the northern Beibu Gulf, their most important spawning and nursery habitats in China. The average TTX contents in both Carcinoscorpius rotundicauda and Tachypleus tridentatus ranged 6.2-8.0 µg/kg and 3.8-8.4 µg/kg, respectively. While sampling location, growth and molt stages have little influence on TTX distribution in both species, significantly higher levels of TTX were detected in hemolymph, but lower in pooled tissues of early-instar juvenile T. tridentatus. These results provide a regional view of TTX occurrence and distribution in HSCs during their spawning season, which are critical for future studies to enhance understanding of TTX dynamics and formation in HSCs.

Community structure of benthic macroinvertebrates in native and introduced mangroves of northern Beibu Gulf, China: Implication for restoring mangrove ecosystems.

Introduced mangroves are widely used to restore mangrove ecosystems in South China. Results of potential impacts on indicative benthic macroinvertebrates are divergent. We explored the community structure of benthic macroinvertebrates in the mangrove ecosystem of northern Beibu Gulf, China across four habitats: native Avicennia marina mangrove, introduced Laguncularia racemosa mangrove, native-introduced mixed mangrove, and unvegetated intertidal flat. Based on the Hill number, community structure was estimated from the dimensions of estimated species richness, diversity, evenness, and species composition similarity. Benthic macroinvertebrates in the unvegetated flat significantly differed from the other three assemblages in mangroves; introduced L. racemosa mangrove had relatively distinct benthic macroinvertebrate assemblage from the native A. marina and the mixed mangroves, with lower species richness and similarity but higher diversity and evenness. Considering the lack of unanimous conclusion of potential impact on benthic macroinvertebrates under complex species interactions, native mangroves should be of top priority in ecosystem restoration.

Impact of Different Diets on Adult Tri-Spine Horseshoe Crab, Tachypleus tridentatus.

Effective culture and management of adult tri-spine horseshoe crab, Tachypleus tridentatus can ensure that stock enhancement programs and aquaculture systems are maintained. To explore suitable feed for animals during the breeding season, Pacific oyster (Ostrea gigas) (oyster group; OG) and frozen sharpbelly fish (Hemiculter leucisculus) (frozen fish group; FG) were selected to feed 20 T. tridentatus male and female pairs, respectively. At the end of the experiment, intestinal samples were obtained to measure digestive enzymes activities. The intestinal flora were determined by 16S rDNA sequencing. No eggs were observed in the FG and one T. tridentatus adult died. No animals died in the OG, and 9.7 × 104 eggs were obtained. These results show that oysters are more suitable for the development and reproduction of adult T. tridentatus than frozen fish. Additionally, the digestive enzyme activity analysis revealed that animals in the OG exhibited higher protein digestibility than those in the FG, but no significant differences in lipid and carbohydrate uptake were observed between the groups. Furthermore, the intestinal flora analysis showed that operational taxonomic units (OTUs) and the Chao1 index were significantly higher in the OG than in the FG, but no significant difference was observed in the Shannon or Simpson indices between the groups. Our data indicate that the oyster diet improved the intestinal microbial diversity of T. tridentatus. We hypothesize that nutrients, such as oyster-based taurine, proteins, and highly unsaturated fatty acids, improve protease activity in the T. tridentatus digestive tract, alter the intestinal floral structure, and improve the reproductive performance of T. tridentatus.

Spatiotemporal Distribution of Asian Horseshoe Crab Eggs Are Highly Intermingled with Anthropogenic Structures in Northern Beibu Gulf, China.

Identification, protection and restoration of spawning habitats are vital for protecting the depleted species. Asian horseshoe crabs are ecologically important macroinvertebrates in coastal and estuarine ecosystems. However, their spawning habitat studies were limited to several reports in tropical regions, possibly due to the lack of modified survey methods, particularly in habitats with a lower density of spawning adults, and/or intermingled with anthropogenic structures. In this study, the year-round egg distribution and spawning habitat baselines of Carcinoscorpius rotundicauda and Tachypleus tridentatus were determined in the northern Beibu Gulf, China. Our findings demonstrated that the peak spawning occurred in June-July and ceased in November-January when the average water temperature dropped below 20 °C. Egg aggregations were found < 10 cm beneath the sediment surface with regular tidal inundation, regardless of seasonal changes, in the vicinity of natural and artificial structures with elevated, mildly sloping substratum within the high tide zones. The nests were characterized by medium-sized sediment grains (0.5-0.9 mm), high temperatures (31-34°C), low water contents (0.8%-0.9%), and total organic carbon contents (0.5%-0.7%), which might maximize the hatching success. The identified nesting beaches were close to nursery habitats for juveniles, and tidal creeks were present as the possible corridor connecting these two important habitats through the dominant mangrove forests. The findings provide valuable insights in the scope of spawning behavior and nest-site selection of Asian horseshoe crabs under a mixture of natural and artificial structures, which could benefit future management efforts for the exploited spawning populations.

Animal models of Kashin-Beck disease exposed to environmental risk factors: Methods and comparisons.

The main etiological mechanism for Kashin-Beck disease (KBD) is deep chondrocyte necrosis induced by environmental risk factors (ERFs). The scholars have conducted several epidemiological, cellular, and animal model studies on ERFs. Gradually, four etiological hypotheses have been formed, including water of organic poisoning hypothesis represented by fulvic acid (FA), biogeochemical hypothesis represented by selenium (Se) deficiency, food mycotoxin poisoning hypothesis represented by T-2 toxin poisoning and compound etiology theory hypothesis. The animal models of KBD have been replicated based on the previous etiological hypotheses. The different species of animals (monkey, rat, dog, pig, chicken, and rabbit) were treated with different ERFs interventions, and the clinical manifestations and pathological changes of articular cartilages were observed. The animals in the experimental group were fed with endemic water, endemic grain, low nutrition, thallium sulfate, FA, Se, T-2 toxin, and iodine. The dose of thallium sulfate was 1154 µg/d; the doses range of FA were 5, 50, 150, 200, and 211 mg/kg; the doses range of Se were 0.00035, 0.00175, 0.005, 0.02, 0.031, 0.1, 0.15, 0.314, 0.5, and 10 mg/kg; the doses range of T-2 toxin were 40, 100, 200, 600, 1000, 1500, 3000, 6000, and 9000 ng/g; and the doses range of iodine were 0.04, 0.18, and 0.4-0.5 µg/g. The sample size ranged from 9 to 230 depending on the interventions and grouping; the follow-up duration ranged from 1 week to 18 months. Moreover, the methods and comparisons of different animal models of KBD had been summarized to provide a useful basis for studying the pathogenesis of KBD. In conclusion, the rhesus monkeys administrated endemic water and grain were susceptible animals to replicate KBD. The rats treated with T-2 toxin combined with Se/nutrition deficiency could be a suitable and widely used animal model.

The first complete mitochondrial genome of the genus Dendronereis, represented by D. chipolini Hsueh, 2019 (Annelida, Nereididae) from Beibu Gluf, China.

The genus Dendronereis Peters, 1854 is characterized in the polychaete family Nereididae by its feather-shaped branchiae on the anterior segments. In this study, we present the first complete mitogenome of Dendronereis, represented by D. chipolini Hsueh, 2019, collected from Beibu Gulf, China. The nucleotide composition is biased toward A + T nucleotides, accounting 31.5% for A, 22.3% for C, 14.7% for G and 31.5% for T. The assembled mitogenome is 15,763 bp in length, with a typical set of 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA), 2 ribosomal RNA (rRNA), and 1 non-coding control region. All genes are encoded on H-strand. The control region is 1260 bp in length and located between tRNA-Gly and tRNA-Met. Phylogenetic study showed that D. chipolini is arranged with high support into the clade of Namanereidinae. The complete mitogenome provides important molecular data for investigating the phylogeny and evolution of the nereid animals.

Novel biallelic mutations in MEI1: expanding the phenotypic spectrum to human embryonic arrest and recurrent implantation failure.

STUDY QUESTION: Are any novel mutations and corresponding new phenotypes, other than recurrent hydatidiform moles, seen in patients with MEI1 mutations? SUMMARY ANSWER: We identified several novel mutations in MEI1 causing new phenotypes of early embryonic arrest and recurrent implantation failure. WHAT IS KNOWN ALREADY: It has been reported that biallelic mutations in MEI1, encoding meiotic double-stranded break formation protein 1, cause azoospermia in men and recurrent hydatidiform moles in women. STUDY DESIGN, SIZE, DURATION: We first focused on a pedigree in which two sisters were diagnosed with recurrent hydatidiform moles in December 2018. After genetic analysis, two novel mutations in MEI1 were identified. We then expanded the mutational screening to patients with the phenotype of embryonic arrest, recurrent implantation failure, and recurrent pregnancy loss, and found another three novel MEI1 mutations in seven new patients from six families recruited from December 2018 to May 2020. PARTICIPANTS/MATERIALS, SETTING, METHODS: Nine primary infertility patients were recruited from the reproduction centers in local hospitals. Genomic DNA from the affected individuals, their family members, and healthy controls was extracted from peripheral blood. The MEI1 mutations were screened using whole-exome sequencing and were confirmed by the Sanger sequencing. In silico analysis of mutations was performed with Sorting Intolerant From Tolerant (SIFT) and Protein Variation Effect Analyzer (PROVEAN). The influence of the MEI1 mutations was determined by western blotting and minigene analysis in vitro. MAIN RESULTS AND THE ROLE OF CHANCE: In this study, we identified five novel mutations in MEI1 in nine patients from seven independent families. Apart from recurrent hydatidiform moles, biallelic mutations in MEI1 were also associated with early embryonic arrest and recurrent implantation failure. In addition, we demonstrated that protein-truncating and missense mutations reduced the protein level of MEI1, while the splicing mutations caused abnormal alternative splicing of MEI1. LIMITATIONS, REASONS FOR CAUTION: Owing to the lack of in vivo data from the oocytes of the patients, the exact molecular mechanism(s) involved in the phenotypes remains unknown and should be further investigated using knock-out or knock-in mice. WIDER IMPLICATIONS OF THE FINDINGS: Our results not only reveal the important role of MEI1 in human oocyte meiosis and early embryonic development, but also extend the phenotypic and mutational spectrum of MEI1 and provide new diagnostic markers for genetic counseling of clinical patients. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Key Research and Development Program of China (2018YFC1003800, 2017YFC1001500, and 2016YFC1000600), the National Natural Science Foundation of China (81725006, 81822019, 81771581, 81971450, and 81971382), the project supported by the Shanghai Municipal Science and Technology Major Project (2017SHZDZX01), the Project of the Shanghai Municipal Science and Technology Commission (19JC1411001), the Natural Science Foundation of Shanghai (19ZR1444500), the Shuguang Program of the Shanghai Education Development Foundation and the Shanghai Municipal Education Commission (18SG03), the Shanghai Health and Family Planning Commission Foundation (20154Y0162), the Strategic Collaborative Research Program of the Ferring Institute of Reproductive Medicine, Ferring Pharmaceuticals and the Chinese Academy of Sciences (FIRMC200507) and the Chongqing Key Laboratory of Human Embryo Engineering (2020KFKT008). No competing interests are declared. TRIAL REGISTRATION NUMBER: N/A.

Ontogenetic resource use and trophic dynamics of endangered juvenile Tachypleus tridentatus among diversified nursery habitats in the northern Beibu Gulf, China.

Horseshoe crabs, the most well-known example of "living fossils", are iconic and ecologically important macroinvertebrates in coastal and estuarine ecosystems. Their blood is a crucial resource for manufacturing Limulus or Tachypleus amebocyte lysate to detect bacterial endotoxins or fungal contamination in drug and medical devices. An enhanced understanding of their ecological roles and trophic interactions in the food webs is fundamental to facilitate resource management for the declining populations in Asia. Foraging information of the Asian species, however, is mainly derived from preliminary, scattered reports from a limited number of study locations. In this study, resource utilization, trophic niche dynamics, and trophic interaction of the juvenile tri-spine horseshoe crab, Tachypleus tridentatus (instars 1-12, approximately 0.5-8 years old) across ontogeny was assessed in diversified nursery habitats along the northern Beibu Gulf, China, using carbon and nitrogen stable isotopes. Our results suggest that: (i) T. tridentatus are ecological generalists given the vast range of carbon isotopic values and trophic niche width estimates exhibited between multiple instar groups; (ii) juvenile T. tridentatus across most habitat types predominantly assimilated energy from a variety of basal production sources in the food web, but primarily depended on sedimentary organic matter and seagrass resource pools; (iii) ontogenetic shifts in juvenile dietary proportions were evident, with decreased reliance on sedimentary organic matter, coupled with increased reliance on benthic macroinvertebrate grazers, detritivores, and omnivores with age; and (iv) nearly all juvenile instars occupied similar trophic positions in the food web with slight shifts in trophic position present with increasing size. Our findings indicate that resource availability and ontogenetic diet shifts strongly influence horseshoe crab trophic dynamics, and age should be accounted when formulating habitat conservation measures based on resource use for Asian horseshoe crabs.

Analysis and Classification of Sleep Stages Based on Common Frequency Pattern From a Single-Channel EEG Signal.

One crucial key of developing an automatic sleep stage scoring method is to extract discriminative features. In this paper, we present a novel technique, termed common frequency pattern (CFP), to extract the variance features from a single-channel electroencephalogram (EEG) signal for sleep stage classification. The learning task is formulated by finding significant frequency patterns that maximize variance for one class and that at the same time, minimize variance for the other class. The proposed methodology for automated sleep scoring is tested on the benchmark Sleep-EDF database and finally achieves 97.9%, 94.22%, and 90.16% accuracy for two-state, three-state, and five-state classification of sleep stages. Experimental results demonstrate that the proposed method identifies discriminative characteristics of sleep stages robustly and achieves better performance as compared to the state-of-the-art sleep staging algorithms. Apart from the enhanced classification, the frequency patterns that are determined by the CFP algorithm is able to find the most significant bands of frequency for classification and could be helpful for a better understanding of the mechanisms of sleep stages.