The Dynamics of a Diffusive Nutrient-Algae Model Based upon the Sanyang Wetland

The stability and spatiotemporal dynamics of a diffusive nutrient-algae model are investigated mathematically and numerically. Mathematical theoretical studies have considered the positivity and boundedness of the solution and the existence, local stability, and global stability of equilibria. Turing instability has also been studied. Furthermore, a series of numerical simulations was performed and a complex Turing pattern found. These results indicate that the nutrient input rate has an important influence on the density and spatial distribution of algae populations. This may help us to obtain a better understanding of the interactions of nutrient and algae and to investigate plankton dynamics in aquatic ecosystems

A Study of the Mechanism of the Congruence of Leader–Follower Power Distance Orientation on Employees’ Task Performance

Based on implicit leadership theory, we examine the congruence effect of leader–follower power distance orientation (PDO) on follower trust in supervisor and work engagement, which in turn influences employees’ task performance. Results of polynomial regressions on 526 dyads supported the congruence effect hypothesis. The results show that (1) the congruence of leader–follower PDO leads to better performance; (2) under the condition of congruence, subordinate task performance is higher when leader–follower PDO matching in low–low ratings congruence than it is in high–high ratings congruence; (3) under the condition of asymmetrical incongruence, the follower had higher task performance when a leader’s PDO is lower than a follower’s PDO; (4) trust in supervisor and the work engagement mediate the effect of congruence of leader–follower PDO on employees’ task performance; (5) trust in supervisor also mediates the effect of congruence of leader–follower PDO on employees’ work engagement

Informal status and taking charge: the different roles of OBSE, P-J fit, and P-S fit

Status in an organization is considered a significant antecedent to an employee’s work-related behaviors. However, the relationship between knowledge workers’ informal status and “taking charge” has been ignored in previous human resource management research. Based on the self-consistency theory, this study examines the mechanisms underlying the influence of knowledge workers’ informal status on taking charge. Data were collected from 337 dyads of employees and their immediate supervisors in 24 enterprises and companies. The results of moderated-mediation analysis indicate organization-based self-esteem (OBSE) fully mediated the positive relationship between knowledge workers’ informal status and taking charge, whereas person-job fit (P-J fit) and person-supervisor fit (P-S fit) each moderated the relationship between knowledge workers’ informal status and OBSE, in addition to the indirect effect of knowledge workers’ informal status on taking charge. Specifically, the indirect effect was strongest when P-J fit or P-S fit was high. The theoretical and managerial implications of the findings, limitations of the study, and future research directions are discussed

Constitutively active BRS3 is a genuinely orphan GPCR in placental mammals.

G protein-coupled receptors (GPCRs) play an important role in physiology and disease and represent the most productive drug targets. Orphan GPCRs, with their endogenous ligands unknown, were considered a source of drug targets and consequently attract great interest to identify their endogenous cognate ligands for deorphanization. However, a contrary view to the ubiquitous existence of endogenous ligands for every GPCR is that there might be a significant overlooked fraction of orphan GPCRs that function constitutively in a ligand-independent manner only. Here, we investigated the evolution of the bombesin receptor-ligand family in vertebrates in which one member-bombesin receptor subtype-3 (BRS3)-is a potential orphan GPCR. With analysis of 17 vertebrate BRS3 structures and 10 vertebrate BRS3 functional data, our results demonstrated that nonplacental vertebrate BRS3 still connects to the original ligands-neuromedin B (NMB) and gastrin-releasing peptide (GRP)-because of adaptive evolution, with significantly changed protein structure, especially in three altered key residues (Q127R, P205S, and R294H) originally involved in ligand binding/activation, whereas the placental mammalian BRS3 lost the binding affinity to NMB/GRP and constitutively activates Gs/Gq/G12 signaling in a ligand-independent manner. Moreover, the N terminus of placental mammalian BRS3 underwent positive selection, exhibiting significant structural differences compared to nonplacental vertebrate BRS3, and this domain plays an important role in constitutive activity of placental mammalian BRS3. In conclusion, constitutively active BRS3 is a genuinely orphan GPCR in placental mammals, including human. To our knowledge, this study identified the first example that might represent a new group of genuinely orphan GPCRs that will never be deorphanized by the discovery of a natural ligand and provided new perspectives in addition to the current ligand-driven GPCR deorphanization

A study of the mechanism of the congruence of leader–follower power distance orientation on employees’ task performance

Based on implicit leadership theory, we examine the congruence effect of leader–follower power distance orientation (PDO) on follower trust in supervisor and work engagement, which in turn influences employees’ task performance. Results of polynomial regressions on 526 dyads supported the congruence effect hypothesis. The results show that (1) the congruence of leader–follower PDO leads to better performance; (2) under the condition of congruence, subordinate task performance is higher when leader–follower PDO matching in low–low ratings congruence than it is in high–high ratings congruence; (3) under the condition of asymmetrical incongruence, the follower had higher task performance when a leader’s PDO is lower than a follower’s PDO; (4) trust in supervisor and the work engagement mediate the effect of congruence of leader–follower PDO on employees’ task performance; (5) trust in supervisor also mediates the effect of congruence of leader–follower PDO on employees’ work engagement

Effect of a magnetic field on macro segregation of the primary silicon phase in hypereutectic Al-Si alloy during directional solidification

International audienceEffect of static magnetic field on longitudinal macro segregation of primary silicon phase has been investigated in directionally solidified hypereutectic Al-Si alloy. Experimental and numerical simulation results indicate that the melt flow of Al-21 wt% Si alloy under magnetic field is the dominant factor leading to macro segregation of primary silicon phase. The intense melt flow, i.e., recirculation loops and microscopic flow, promotes solute Si to the mushy zone and sidewall of the crucible where the temperature is low and the primary silicon is more likely to precipitate, resulting in the formation of the U-shaped interface. The precipitated primary silicon tends to disappear during directional solidification, which induces the transition from the U-shaped interface to the planar interface. The increase of magnetic field intensity accelerates this transition process and increases the macro segregation. Furthermore, the freely drifted fine silicon particles in the bulk melt are transported to mushy zone by the forced flow, which contributes to macro segregation. This work facilitates the understanding of forced flow greatly changing the solidification structures of alloys under the magnetic field during directional solidification

Antimicrobial resistance and multilocus sequence typing analysis of Vibrio parahaemolyticus from seafood in Chengdu

Objective To find out the contamination, antimicrobial resistance, virulence gene distribution and genotyping of Vibrio parahaemolyticus in different kinds of marine products in Chengdu. Increase the basic data on the prevalence and risk assessment of foodborne Vibrio parahaemolyticus in Chengdu. Methods According to GB 4789.7-2013, suspected strains of Vibrio parahaemolyticus were isolated from different marine products and accurately identified by biochemical tests and 16S rDNA sequencing. The antimicrobial resistance test of the isolated strains was carried out by Kirby-Bauer disk diffusion method. Two virulence genes related to its pathogenicity were detected by polymerase chain reaction (PCR), and then the isolated strains were typed by multilocus sequence typing. Results A total of 104 strains of Vibrio parahaemolyticus were isolated from 380 seafood samples collected, with an overall detection rate of 27.4%. Antimicrobial resistance test showed that 97.1% (101/104) of the isolates had resistance, of which the drug resistance rate to ampicillin was the highest (95.2%, 99/104). The harboring rate of trh gene among the isolated strains was 12.5% (13/104), and was 0.1% (1/104) for tdh gene.104 isolates were divided into 38 ST types, of which ST1801, ST392 and ST413 were at high level. No epidemic clone group was found in the isolates. Conclusion There were differences in the contamination rate, antimicrobial resistance, and virulence genes distribution of Vibrio parahaemolyticus in different kinds of marine products, which might be related to the breeding environment and transportation conditions

Study on the welding properties of modified N50 CICC jacket for future fusion applications

The modified N50 (N50H) cable-in-conduit conductor CICC jacket developed by China will be applied in China Fusion Engineering Test Reactor (CFETR). Building upon the N50H material, China has developed a corresponding welding material and conducted R&D work on N50H jacket welding. We simulated the N50H jacket welded joint to replicate the entire process of CICC preparation, which includes extrusion, bending, straightening and aging. The magnetic properties of welded joints were evaluated at various temperatures using a physical property measurement system. In addition, the microstructure of the welded joint was studied by various microscopic analysis techniques, and the welded joint showed a stable austenitic structure. Furthermore, mechanical properties of the welded joints were investigated at different temperatures with particular emphasis on their behavior at 4.2 K. The circle-in-square ReBCO conductor jackets welding joint showed a yield strength greater than 1500 MPa, a fracture toughness KIC better than 260 MPa m1/2 and the elongation at break is more than 30 % at 4.2 K. However, a decrease in strength, ductility, and fracture toughness is observed within the welded joints of Nb3Sn conductor jackets after undergoing an aging process. This study will present experimental data on welding joints and discuss the feasibility of N50H as a high-magnetic field jacket material for next-generation fusion reactors

DataSheet_2_Gut microbiota composition is associated with disease severity and host immune responses in COVID-19.pdf

BackgroundHuman gut microbiota play a crucial role in the immune response of the host to respiratory viral infection. However, evidence regarding the association between the gut microbiome, host immune responses, and disease severity in coronavirus disease 2019 (COVID-19) remains insufficient.MethodsTo better comprehend the interactions between the host and gut microbiota in COVID-19, we conducted 16S rRNA sequencing and characterized the gut microbiome compositions in stool samples from 40 COVID-19 patients and 33 non-pneumonia controls. We assessed several hematological parameters to determine the immune status.ResultsWe found that the gut microbial composition was significantly changed in COVID-19 patients, which was characterized by increased opportunistic pathogens and decreased commensal bacteria. The frequency of prevalent opportunistic pathogens Enterococcus and Lactobacillus increased, especially in severe patients; yet the abundance of butyrate-producing bacteria, Faecalibacterium, Roseburia, and Anaerostipes, decreased significantly, and Faecalibacterium prausnitzii might help discriminate severe patients from moderate patients and non-pneumonia people. Furthermore, we then obtained a correlation map between the clinical characteristics of COVID-19 and severity-related gut microbiota. We observed a notable correlation between the abundance of Enterococcus faecium and abnormal neutrophil or lymphocyte percentage in all COVID-19 patients. Faecalibacterium was positively correlated with lymphocyte counts, while negatively correlated with neutrophil percentage.ConclusionThese results suggested that the gut microbiome could have a potential function in regulating host immune responses and impacting the severity or consequences of diseases.</p

DataSheet_1_Gut microbiota composition is associated with disease severity and host immune responses in COVID-19.pdf

BackgroundHuman gut microbiota play a crucial role in the immune response of the host to respiratory viral infection. However, evidence regarding the association between the gut microbiome, host immune responses, and disease severity in coronavirus disease 2019 (COVID-19) remains insufficient.MethodsTo better comprehend the interactions between the host and gut microbiota in COVID-19, we conducted 16S rRNA sequencing and characterized the gut microbiome compositions in stool samples from 40 COVID-19 patients and 33 non-pneumonia controls. We assessed several hematological parameters to determine the immune status.ResultsWe found that the gut microbial composition was significantly changed in COVID-19 patients, which was characterized by increased opportunistic pathogens and decreased commensal bacteria. The frequency of prevalent opportunistic pathogens Enterococcus and Lactobacillus increased, especially in severe patients; yet the abundance of butyrate-producing bacteria, Faecalibacterium, Roseburia, and Anaerostipes, decreased significantly, and Faecalibacterium prausnitzii might help discriminate severe patients from moderate patients and non-pneumonia people. Furthermore, we then obtained a correlation map between the clinical characteristics of COVID-19 and severity-related gut microbiota. We observed a notable correlation between the abundance of Enterococcus faecium and abnormal neutrophil or lymphocyte percentage in all COVID-19 patients. Faecalibacterium was positively correlated with lymphocyte counts, while negatively correlated with neutrophil percentage.ConclusionThese results suggested that the gut microbiome could have a potential function in regulating host immune responses and impacting the severity or consequences of diseases.</p