16 research outputs found
Biological parameters estimate for the sickle pomfret (Taractichthys steindachneri) in the west-central and eastern Pacific Ocean
373-381This study was undertaken to provide some preliminary biological information for Sickle pomfrets Taractichthys steindachneri from length frequency data (LFD) obtained through the Chinese Longline Fisheries Observer Programme in the Pacific Ocean obtained from August 2016 to March 2017. We fitted the seasonally oscillating von Bertalanffy Growth Function (so VBGF) by applying two optimized ELEFAN approaches ('simulated annealing' ELEFAN S.A. and 'genetic algorithm' ELEFAN G.A.). ELEFAN S.A. presented the best score and was later used to obtain the following results: FL∞ = 101 cm, k = 0.52 yr−1, t_anchor = 0.73, C = 0.75, ts = 0.2, and growth performance index of ∅ = 3.72; natural mortality M = 0.55 yr−1, total mortality Z = 1.37 yr−1, fishing mortality F = 0.82 yr−1, exploitation rate E = 0.59, length at first sexual maturity Lm = 67.5 cm corresponding to 2.47 years (age at first sexual maturity); major recruitment and highest catch rate occurred in January. F and E at maximum sustainable yield were Fmsy = 1.7 yr-1 and Emsy = 0.754, respectively. In this study, E and results of yield-per-recruit models indicate that these fisheries are sustainably harvested, and maximum sustainable yield could be acquired, if F is increased to Fmsy
Length-Based Assessment Methods for the Conservation of a Pelagic Shark, <i>Carcharhinus falciformis</i> from the Tropical Pacific Ocean
The silky shark, Carcharhinus falciformis is one of the most heavily exploited sharks, being the main by-catch species in both tuna longline and purse-seine fisheries in tropical waters worldwide. Despite this severe exploitation, little is known about the species’ life history and population status. Silky sharks, like many other sharks, exhibit slow growth and low fecundity, indicating the urgency of developing assessment studies to aid in the implementation of conservation plans for their stocks. Because information on the catch and effort of this species is scarce, some length-based data-limited methods were applied in the present study to provide estimates of the status of the tropical Pacific silky shark population. As evident from the LBSPR analysis, the current spawning potential ratio (SPR) was found to be below the target reference point of SPR 40% and slightly above the limit reference point of SPR 20%. In addition, the LBB model also confirmed that this stock’s status is overfished with relatively low biomass levels. Furthermore, both models showed estimates of size selectivity at 50% and 95% that were lower than the estimated size at sexual maturity. In conclusion, the data-limited models developed in this study indicated that the silky shark stock in the tropical Pacific Ocean may be at risk of further decline. Additionally, the results show that growth and recruitment overfishing may be occurring in the silky shark’s population calling for immediate intensification of monitoring programs for these sharks as a pre-requisite to develop efficient management and conservation plans in the Pacific Ocean
A highly efficient single site Rh-POL-PPh3 catalyst for heterogeneous methanol carbonylation
In Contrast to the Monsanto homogeneous system, the Rh heterogeneous methanol carbonylation universally displays lower activity and stability. Here, a single site catalyst Rh-POL-PPh3 was successfully prepared by impregnation of the Rh-2(CO)(4)C-12 dichloromethane solution, and applied to heterogeneous methanol carbonylation in a continuous fixed-bed reactor for the first time. Due to single site Rh species and the electron-donating effect of P ligands and the strong multicoordination bonds between Rh and P, the Rh-POL-PPh3 catalyst exhibited a little higher TOF of 1550 h(-1) than that of optimized Monsanto process and maintained relatively stable activity for near 180 h under 2.5 MPa, 195 degrees C. Thus, POL-PPh3 not only acts as a stable support but also a promotion of methanol carbonylation process. (C) 2017 Elsevier B.V. All rights reserved
La-Stabilized, Single-Atom Ir/AC Catalyst for Heterogeneous Methanol Carbonylation to Methyl Acetate
Although homogeneous methanol carbonylation is industrialized to produce acetic acid, it still suffers from the problems of difficult separation and metal leaching. Here, we report a heterogeneous single atom Ir-La/AC catalyst to produce methyl acetate in a fixed-bed reactor. A high TOF of 2200h(-1) and high selectivity over 90% for methyl acetate with space time yield of 8200 g/(kg(cat) h) were achieved over the Ir-La/AC catalyst. Furthermore, the effects of reaction temperature, partial pressure of CO and CH3OH, weight ratio of CH3I/CH3OH, total LHSV as well as the role of La on the catalytic performance of Ir/AC were tested in this paper. In addition, we proposed a reasonable mechanism for heterogeneous methanol carbonylation over La stabilized single atom Ir/AC catalyst. Our work provides a reference for the further scale-up of the process and a stable, supported, single-atom system as a substitution for other homogeneous catalyst
Environmental Characteristics Associated with the Presence of the Pelagic Stingray (<i>Pteroplatytrygon violacea</i>) in the Pacific High Sea
The pelagic stingray (Pteroplatytrygon violacea), perhaps the only stingray to inhabit open ocean waters, is highly interactive with longline and purse seine fisheries. The threat to P. violacea posed by high bycatch mortality has received widespread attention. To date, the environmental preference of P. violacea, which is important in designing conservation and management measures, has not been well studied. Based on data collected during a 2016–2019 survey in the Pacific Ocean by national observers of tuna longline fisheries, the relationship between the presence of P. violacea and spatiotemporal and environmental variables was first analyzed using the Generalized Additive Model. The results showed that geographic location (latitude and longitude) was the most influential variable. Monthly, P. violacea is frequently present in the Pacific high sea from December to May. The El Niño–Southern Oscillation had a significant impact on the presence of P. violacea in the Pacific high sea, with both the cold (Ocean Nino Index 1) phases leading to a decrease in its presence. Regarding the environmental factors, we found that high presence was associated with low salinity (33.0~34.5 psu), a relatively high concentration of chlorophyll (0.2–0.35 mg/m3), and warm water (>20 °C). P. violacea was most likely observed in the waters offshore, closer to seamounts, and with water depths between 4000 and 5000 m. Four areas, including those east of the Solomon Islands and east of Kiribati, areas west of the Galapagos Islands, and areas near the coastal upwelling of northern Peru, related to upwelling systems or seamounts, were identified as the potential key habitats of P. violacea. Predicted distribution maps showed a significant seasonal variation in the presence of P. violacea. Moreover, the yearly change in the presence of P. violacea in the Pacific high sea indicated a possible decreasing trend in recent years. The information first provided here is essential for developing conservation and management measures for P. violacea to prevent the unavoidable ecological consequences of bycatch or other anthropogenic factors
Auditory and speech outcomes of cochlear implantation in patients with Waardenburg syndrome: a meta-analysis
ObjectiveThis study aims to assess the potential efficacy of cochlear implantation as a treatment for patients with Waardenburg syndrome (WS) and to guide clinical work by comparing the effect of auditory and speech recovery after cochlear implantation in patients with WS and non-WS.MethodsPubMed, the Cochrane Library, CNKI, and Wanfang Data were sources for retrieving literature on cochlear implantation in WS, and clinical data meeting the inclusion criteria were meta-analyzed using RevMan5.41.ResultsA total of nine articles were included in this study, including 132 patients with WS and 815 patients in the control group. Meta-analysis showed that there are no significant differences in the scores for categories of audit performance (CAP), speech intelligibility rating (SIR), and parents’ evaluation of aural/oral performance of children (PEACH) between the WS group and the control group.ConclusionCochlear implantation demonstrates comparable auditory and speech recovery outcomes for WS patients and non-WS patients
Single-atom Rh based bipyridine framework porous organic polymer: A high active and superb stable catalyst for heterogeneous methanol carbonylation
A novel Rh based porous composed N polymer with hierarchical pore, high surface area and high thermal stability (Rh-POL-2BPY) was successfully obtained by impregnation of Rh-2(CO)(4)Cl-2 solution of dichloromethane. And based on Rh species as the most active carbonylation site, Rh-POL-2BPY was selected as a catalyst applied in heterogeneous methanol carbonylation system and behaved excellent carbonylation activity (TOF approximate to 1400 h(-1)) under 195 degrees C, 2.5 MPa, higher than the corresponding homogeneous system without acetic acid. In addition, contrast to the most reported unstable heterogeneous methanol carbonylation systems, Rh-POL-2BPY could maintain incredibly outstanding stability for near 400 h owing to the firm coordination bond between Rh and N and high exposed N content in the polymer. Here, POL-2BPY apart from its heat-resisting property acts as massive rivets to immobilize the Rh species in its framework solidly during carbonylation process. XPS, XANES, HAADF-STEM and EXAFS results verify the N species of bipyridine, the single atom dispersion of Rh and Rh-N coordination bond. And above all, the novel five coordinated Rh center is proposed as the real active site of methanol carbonylation by EXAFS spectra. (C) 2018 Elsevier Inc. All rights reserved
KAP1 Positively Modulates Influenza A Virus Replication by Interacting with PB2 and NS1 Proteins in Human Lung Epithelial Cells
Influenza virus only encodes a dozen of viral proteins, which need to use host machinery to complete the viral life cycle. Previously, KAP1 was identified as one host protein that potentially interacts with influenza viral proteins in HEK 293 cells. However, the role of KAP1 in influenza virus replication in human lung alveolar epithelial cells and the underlying mechanism remains unclear. In this study, we first generated KAP1 KO A549 cells by CRISPR/Cas9 gene editing. KAP1 deletion had no significant effect on the cell viability and lack of KAP1 expression significantly reduced the influenza A virus replication. Moreover, we demonstrated that KAP1 is involved in the influenza virus entry, transcription/replication of viral genome, and viral protein synthesis in human lung epithelial cells and confirmed that KAP1 interacted with PB2 and NS1 viral proteins during the virus infection. Further study showed that KAP1 inhibited the production of type I IFN and overexpression of KAP1 significantly reduced the IFN-β production. In addition, influenza virus infection induces the deSUMOylation and enhanced phosphorylation of KAP1. Our results suggested that KAP1 is required for the replication of influenza A virus and mediates the replication of influenza A virus by facilitating viral infectivity and synthesis of viral proteins, enhancing viral polymerase activity, and inhibiting the type I IFN production
A Glycolipid α-GalCer Derivative, 7DW8-5 as a Novel Mucosal Adjuvant for the Split Inactivated Influenza Vaccine
Influenza virus infects the host and transmits through the respiratory tract (i.e., the mouth and nose); therefore, the development of intranasal influenza vaccines that mimic the natural infection, coupled with an efficient mucosal adjuvant, is an attractive alternative to current parenteral vaccines. However, with the withdrawal of cholera toxin and Escherichia coli heat-labile endotoxin from clinical use due to side effects, there are no approved adjuvants for intranasal vaccines. Therefore, safe and effective mucosal adjuvants are urgently needed. Previously, we reported that one derivative of α-Galactosylceramide (α-GalCer), 7DW8-5, could enhance the protective efficacy of split influenza vaccine by injection administration. However, the mucosal adjuvanticity of 7DW8-5 is still unclear. In this study, we found that 7DW8-5 promotes the production of secret IgA antibodies and IgG antibodies and enhances the protective efficacy of the split influenza vaccine by intranasal administration. Furthermore, co-administration of 7DW8-5 with the split influenza vaccine significantly reduces the virus shedding in the upper and lower respiratory tract after lethal challenge. Our results demonstrate that 7DW8-5 is a novel mucosal adjuvant for the split influenza vaccine