Distribución del tamaño y variación mensual del desarrollo ovárico del cangrejo azul hembra, Portunus pelagicus en el golfo de Beibu, frente al sur de China

The present study was conducted to investigate the size distribution and seasonality variation of ovarian development for females of the blue swimmer crab, Portunus pelagicus, from Beibu Gulf, China. The results show that, based on pubertal moult, gonadosomatic index (GSI), morphology and histological configurations, the ovarian development cycle of P. pelagicus can be divided into five stages; Stage I, dominated by oogonia with some previtellogenic oocytes and endogenous vitellogeic oocytes; Stage II, dominated by endogenous vitellogenic oocytes with some previtellogeic oocytes and oogonia; Stage III, dominated by exogenous vitellogeic oocytes; Stage IV, of nearly mature oocytes; and Stage V, of mature oocytes with fully ripened ovary. GSI increased significantly during the ovarian development (P < 0.05), while the hepatosomatic index (HSI) appeared to decrease. Thus, a significant negative correlation was found between GSI and HSI (P < 0.01). The smallest carapace width of a mature female and that at which 50% of females reach maturity were 79.2 mm and 108.2 mm, respectively. The carapace width and body weight of the dominant size class ranged between 86 and 115 mm and 40 and 120 g, respectively. Furthermore, the highest GSI of female P. pelagicus was found in March, while the peak of ovigerous females was found in April.Este estudio se realizó para investigar la distribución del tamaño y la estacionalidad de desarrollo ovárico del cangrejo azul hembra, Portunus pelagicus en el golfo de Beibu, China. Los resultados muestran que, sobre la base de la muda de la pubertad, el GSI (índice gonadosomático), la morfología y las configuraciones histológicos y el ciclo del desarrollo ovárico de P. pelagicus puede dividirse en cinco etapas. Etapa I: La fase de oogonia (OG) dominaba con algunos ovocitos previtelogeicos (PR) y ovocitos vitelogeicos endógenos (EN); Etapa II: fase de EN dominaba con algunos PR y OG; Etapa III: la fase de ovocitos vitelogeicos exógenos (EX) era dominante; Etapa IV: fase de ovocitos casi maduros (NO); Etapa V: fase de ovocitos maduros (MO) y maduración completa del ovario. El índice gonadosomático (GSI) aumentó significativamente durante el desarrollo del ovario (P < 0.05), mientras que el índice hepatosomático (HSI) parecía disminuir. Por lo tanto, se encontró una correlación negativa significativa entre GSI y HSI (P < 0.01). La menor anchura del caparazón (CW) de una hembra madura y CW del 50% de las hembras maduras eran 79.2 mm y 108.2 mm, respectivamente. La CW y el peso corporal de la clase de tamaño dominante oscilaban entre 86-115 mm y 40-120 g respectivamente. Por otra parte, el GSI de la hembra más grande de P. pelagicus se encontró en marzo, mientras que el pico de las hembras ovígeras se produjo en abril en la población del golfo de Beibu

Performance analysis of hybrid UAV networks for probabilistic content caching

Caching content in small-cell networks can reduce the traffic congestion in backhaul. In this article, we develop a hybrid caching network comprising of unmanned aerial vehicles (UAVs) and ground small-cell base stations (SBSs), where UAVs are preferred because of their flexibility and elevated platform for line of sight. First, we derive the association probability for the ground user affiliated with a UAV and ground SBS. Then, we derive the successful content delivery probability by considering both the intercell and intracell interference. We also analyze the energy efficiency of the hybrid network and compare it with the separate UAV and ground networks. We further propose the caching scheme to improve the successful content delivery by managing the content popularity, where the part of the caching capacity in each UAV and ground SBS is reserved to store the most popular content (MPC), while the remaining stores less popular contents. Numerical results unveil that the proposed caching scheme has an improvement of 26.6% in content delivery performance over the MPC caching, which overlooks the impact of content diversity during caching

Satellite-MEC Integration for 6G Internet of Things: Minimal Structures, Advances, and Prospects

The sixth-generation (6G) network is envisioned to shift its focus from the service requirements of human beings' to those of Internet-of-Things (IoT) devices'. Satellite communications are indispensable in 6G to support IoT devices operating in rural or disastrous areas. However, satellite networks face the inherent challenges of low data rate and large latency, which may not support computation-intensive and delay-sensitive IoT applications. Mobile Edge Computing (MEC) is a burgeoning paradigm by extending cloud computing capabilities to the network edge. By utilizing MEC technologies, the resource-limited IoT devices can access abundant computation resources with low latency, which enables the highly demanding applications while meeting strict delay requirements. Therefore, an integration of satellite communications and MEC technologies is necessary to better enable 6G IoT. In this survey, we provide a holistic overview of satellite-MEC integration. We first discuss the main challenges of the integrated satellite-MEC network and propose three minimal integrating structures. For each minimal structure, we summarize the current advances in terms of their research topics, after which we discuss the lessons learned and future directions of the minimal structure. Finally, we outline potential research issues to envision a more intelligent, more secure, and greener integrated satellite-MEC network

Proteomic Analysis of the Hepatopancreas of Chinese Mitten Crabs (Eriocheir sinensis) Fed With a Linoleic Acid or α-Linolenic Acid Diet

As representatives of n-6 and n-3 fatty acids, many studies have analyzed the use of soybean oil and linseed oil rich in linoleic acid (18:2n-6, LA) and α-linolenic acid (18:3n-3, LNA) as better substitutes for fish oil. In aquatic animals, different dietary ratios of LA and LNA could have significant effects on growth, lipid metabolism, immune response, and reproduction. To assess the nutritive value of these two fatty acids in Chinese mitten crab (Eriocheir sinensis), we performed transcriptome analysis and label-free quantification proteomic analysis of the hepatopancreas from mitten crabs fed with LA or LNA diet. Parallel reaction monitoring was used to confirm the reliability of the proteomic analysis. A total of 186 proteins were differentially expressed with fold change ≥1.5 or ≤0.666. Among the 186 proteins, 116 were upregulated and 70 were downregulated in the LA than LNA. Most of these proteins participate in cellular process and metabolism process and have molecular functions such as binding and catalytic activity; the cellular component of these proteins are cell, cell part, membrane, and membrane part. A total of 18 proteins were identified to be related to lipid, carbohydrate, and protein metabolism, and they mainly participate in digestive enzyme activities, fatty acid transport, and glycolysis. Our results provide new insights for further investigation into the replacement of fish oil from mitten crabs with vegetable oils and enable us to better understand the different roles and nutrition value of LA and LNA in mitten crabs

Genome Characterization and Phylogenetic Analysis of Bovine Hepacivirus in Inner Mongolia, Northeastern China

Bovine hepacivirus (BovHepV) is a new member of the genus Hepacivirus in the family Flaviviridae , which has been detected in cattle in more than seven countries. The purpose of this study was to identify and genetically characterize BovHepV in cattle in Inner Mongolia, northeastern (NE) China. A total of 116 serum samples from cattle were collected from HulunBuir in Inner Mongolia from April to May, 2021, and were divided into three pools for metagenomic sequencing. The samples were verified with semi-nested RT-PCR with primers based on the BovHepV sequences obtained from metagenomic sequencing. The complete genomes of BovHepV were amplified, and were used for genome characterization and phylogenetic analysis. BovHepV was detected in two pools through metagenomic sequencing. Five BovHepV positive samples were identified in Yakeshi of HulunBuir, thus indicating a prevalence of 8.8% (5/57). Two 8840 nucleotide long BovHepV strains YKS01/02 were amplified from the positive samples and showed 79.3%–91.9% nucleotide sequence identity with the discovered BovHepV strains. Phylogenetic analysis classified the YKS01/02 strains into BovHepV subtype G group. This study reports the first identification of BovHepV in cattle in northeastern China, and expands the known geographical distribution and genetic diversity of BovHepV in the country

Size distribution and monthly variation of ovarian development for the female blue swimmer crab, <em>Portunus pelagicus</em> in Beibu Gulf, off south China

The present study was conducted to investigate the size distribution and seasonality variation of ovarian development for females of the blue swimmer crab, Portunus pelagicus, from Beibu Gulf, China. The results show that, based on pubertal moult, gonadosomatic index (GSI), morphology and histological configurations, the ovarian development cycle of P. pelagicus can be divided into five stages; Stage I, dominated by oogonia with some previtellogenic oocytes and endogenous vitellogeic oocytes; Stage II, dominated by endogenous vitellogenic oocytes with some previtellogeic oocytes and oogonia; Stage III, dominated by exogenous vitellogeic oocytes; Stage IV, of nearly mature oocytes; and Stage V, of mature oocytes with fully ripened ovary. GSI increased significantly during the ovarian development (P < 0.05), while the hepatosomatic index (HSI) appeared to decrease. Thus, a significant negative correlation was found between GSI and HSI (P < 0.01). The smallest carapace width of a mature female and that at which 50% of females reach maturity were 79.2 mm and 108.2 mm, respectively. The carapace width and body weight of the dominant size class ranged between 86 and 115 mm and 40 and 120 g, respectively. Furthermore, the highest GSI of female P. pelagicus was found in March, while the peak of ovigerous females was found in April

Effects of the complete replacement of fish oil with linseed oil on growth, fatty acid composition, and protein expression in the Chinese mitten crab (Eriocheir sinensis)

Abstract Background The finite marine resources make it difficult for us to obtain enough fish oil (FO) used in aquatic feeds. Another sustainable ingredients should be found to substitute FO. The effects of replacing FO with vegetable oil have been studied in a variety of crustaceans, but most studies have focused on the phenotypic effects. Little is known about the mechanisms of the effects. Methods To understand the molecular responses during the replacement of FO in Eriocheir sinensis, we investigated the effects of feeding FO or linseed oil (LO) on growth performance, digestive enzyme activity, fatty acid composition and protein expression in E. sinensis. Twenty-four juvenile crabs were fed diets containing FO or LO for 112 days. Weight, carapace length and width were recorded. Fatty acid composition of the diets and the hepatopancreas and protein expression in the hepatopancreas were analyzed. Results Growth performance and molting interval were unchanged by diet. Crabs fed FO and LO had same activity of lipase and amylase, but comparing with crabs fed LO, crabs fed FO had higher trypsin activity and lower pepsin activity. Hepatopancreas fatty acid composition changed to reflect the fatty acid composition of the diets. In total, 194 proteins were differentially expressed in the hepatopancreas between the diets. Expression of heat shock proteins was higher in crabs fed LO. Expression of fatty acid synthase, long-chain fatty acid transport protein 4, acyl-CoA delta-9 desaturase, and fatty acid-binding protein 1, was higher in crabs fed FO. Conclusions The substitution of FO with LO didn’t have any effects on the growth and molting of mitten crab, but could significantly decrease the ability of mitten crab to cope with stress. The high content of HUFAs in the hepatopancreas of mitten crab fed FO is due to the high abundance of the proteins relative to the transport of the HUFAs. These findings provide a reason of the high content of EPA and DHA in crabs fed with FO, and provide new information for the replacement of FO in diets of mitten crab

Altered spontaneous brain activity in patients with hemifacial spasm: a resting-state functional MRI study.

Resting-state functional magnetic resonance imaging (fMRI) has been used to detect the alterations of spontaneous neuronal activity in various neurological and neuropsychiatric diseases, but rarely in hemifacial spasm (HFS), a nervous system disorder. We used resting-state fMRI with regional homogeneity (ReHo) analysis to investigate changes in spontaneous brain activity of patients with HFS and to determine the relationship of these functional changes with clinical features. Thirty patients with HFS and 33 age-, sex-, and education-matched healthy controls were included in this study. Compared with controls, HFS patients had significantly decreased ReHo values in left middle frontal gyrus (MFG), left medial cingulate cortex (MCC), left lingual gyrus, right superior temporal gyrus (STG) and right precuneus; and increased ReHo values in left precentral gyrus, anterior cingulate cortex (ACC), right brainstem, and right cerebellum. Furthermore, the mean ReHo value in brainstem showed a positive correlation with the spasm severity (r = 0.404, p = 0.027), and the mean ReHo value in MFG was inversely related with spasm severity in HFS group (r = -0.398, p = 0.028). This study reveals that HFS is associated with abnormal spontaneous brain activity in brain regions most involved in motor control and blinking movement. The disturbances of spontaneous brain activity reflected by ReHo measurements may provide insights into the neurological pathophysiology of HFS

Comparative transcriptome analysis reveals osmotic-regulated genes in the gill of Chinese mitten crab (Eriocheir sinensis).

Salinity is one of the most important abiotic factors directly affecting the reproduction, molting, growth, immune, physiological and metabolic activities of Chinese mitten crab (Eriocheir sinensis). This species has strong osmoregulatory capacity and can maintain stringent internal homeostasis. However, the mechanisms conferring tolerance to salinity fluctuations are not well understood. To reveal the genes and pathways involved in osmoregulation, adult male crabs (body weight = 110 ± 5 g) were acclimated for 144 h in freshwater (FW, 0 ppt) or seawater (SW, 25 ppt). Changes in the transcriptome of crab gills were then analysed by RNA-Seq, and 174,903 unigenes were obtained. Comparison of genes between FW- SW-acclimated groups identified 932 genes that were significantly differentially expressed in the gill, comprising 433 and 499 up- and downregulated transcripts. Gene Ontology functional enrichment analysis revealed that important biological processes related to salt stress were significantly enriched, including energy metabolism, ion transport, signal transduction and antioxidant activity. Kyoto Encyclopaedia of Genes and Genomes enrichment analysis mapped the differentially expressed genes to 241 specific metabolic pathways, and pathways related to energy metabolism, oxidative phosphorylation and the tricarboxylic acid (TCA)/citrate cycle were significantly enriched. Salinity stress altered the expression of many enzymes involved in energy metabolism, ion transport, signal transduction and antioxidant pathways, including citrate synthase (CS), Na+/K+-ATPase (NKA), Na+-K+-2Cl cotransporter-1 (NKCC1), dopamine receptor D1 (DRD1), synaptic binding protein 1 (STXBP1), Cu2+/Zn2+ superoxide dismutase (SOD1) and glutathione S-transferase (GST). Additionally, the obtained transcriptomic sequencing data provided a useful resource for identification of novel genes, and further physiological analysis of Chinese mitten crab