Energy flow analysis of grass carp pond system based on Ecopath model.

Grass carp (Ctenopharyngodon idellus) is the most productive freshwater fish in China, but its traditional aquaculture model still has problems, such as poor water quality and frequent diseases. We have taken monoculture and 80:20 polyculture grass carp ponds as the research object and used EwE software to build the Ecopath model of two ponds. We analyzed and compared the characteristics of ecological structure and energy flow in two ponds. The result showed the highest effective trophic level in the polyculture pond that was higher than that in the monoculture pond, and fish in polyculture had higher EE values which showed the production of fish in polyculture contributed more to the energy conversion efficiency of the ecosystem. Flows into detritus were the largest component of TST both in the two ponds, which accounted for 49.34% and 50.37%. And the average transfer efficiency in monoculture was 13.07%, while that in polyculture was 15.6%. The ascendency/total development capacity (A/TDC) and overhead/total development capacity (O/TDC) were 0.35 and 0.65 both in the two ponds, respectively, which indicated that both systems had a strong anti-perturbation ability, but the stability could be improved. Finn's cycling index (FCI) in polyculture was higher and showed that the polyculture pond was more mature and stable. Unused energy of functional groups will flow to detritus, and that in the monoculture pond was higher, the energy of C. idellus that flowed to detritus in monoculture was 48.17% higher than that in polyculture; unused energy of bacteria and phytoplankton were also high. The result showed that polyculture could improve energy utilization, increase transfer efficiency, and raise the stability of the ecosystem. Grass carp ponds still need to be improved in the aspects of mixed species and energy consumption. It is necessary to improve the ecological and economic benefits of grass carp ponds by optimizing the aquaculture structure and adjusting the aquaculture proportion.

Occurrence of microplastic pollution in rivers globally: Driving factors of distribution and ecological risk assessment.

Microplastics, as global emerging pollutants, have received significant attention worldwide due to their ubiquitous presence in the rivers. However, there is still a lack of clarity on the occurrence, driving factors, and ecological risks of microplastics in rivers worldwide. In this study, a global microplastic dataset based on 862 water samples and 445 sediment samples obtained from 63 articles was constructed, which revealed the temporal and spatial distribution of abundance and morphological characteristics of microplastics in rivers across the globe. In global rivers, the abundance of MPs in both water and sediment spans across 10 and 4 orders of magnitude, respectively. The MP comprehensive diversity index based on the physical morphological characteristics of MPs indicated a significant positive correlation between the pollution sources of MPs in different environmental media. Based on the data was aligned to the full-scale MPs, a novel framework was provided to evaluate the ecological risk of MPs and the interaction effects between the influencing factors driving the distribution characteristics of MPs in rivers around the world. The results obtained demonstrated a wide variation in the key driving factors affecting the distribution of microplastics in different environmental media (water and sediment) in rivers globally. The diversity indices of the morphological characteristics of MPs in densely populated areas of lower-middle income countries in Asia were significantly higher, implying that the sources of microplastics in these regions are more complex and extensive. More than half of the rivers are exposed to potential ecological risks of MPs; however, microplastics may pose only immediate risks to aquatic species in Burigang River, Bangladesh. This can provide valuable insights for formulating more effective scientific strategies for the management of MP pollution in rivers.

Molecular characterization and immune efficacy of fructose-1,6-bisphosphate aldolase from Haemaphysalis longicornis (Acari: Ixodidae).

BACKGROUND: Ticks are obligate hematophagous ectoparasites that transmit a variety of pathogens to humans, wildlife and domestic animals. Vaccination is an effective and environmentally friendly method for tick control. Fructose-1,6-bisphosphate aldolase (FBA) is an important glycometabolism enzyme that is a candidate vaccine against parasites. However, the immune protection of FBA in ticks is unclear. METHODS AND RESULTS: The 1092-bp open reading frame (ORF) of FBA from Haemaphysalis longicornis (HlFBA), encoding a 363-amino acid protein, was cloned using PCR methodology. The prokaryotic expression vector pET32a(+)-HlFBA was constructed and transformed into cells of Escherichia coli BL21(DE3) strain for protein expression. The recombinant HlFBA protein (rHlFBA) was purified by affinity chromatography, and the western blot results suggested that the rHlFBA protein was immunogenic. RESULTS: Results of the enzyme-linked immunosorbent assay showed that rabbits immunized with rHlFBA produced a humoral immune response specific to rHlFBA. A tick infestation trial indicated that, compared to the ticks in the histidine-tagged thioredoxin (Trx) group, the engorged tick weight and oviposition of female ticks and egg hatching rate of those in the rHlFBA group was reduced by 22.6%, 45.6% and 24.1%, respectively. Based on the cumulative effect of the these three parameters, the overall immune efficacy of rHlFBA was estimated to be 68.4%. CONCLUSIONS: FBA is a candidate anti-tick vaccine that can significantly reduce the engorged tick weight, oviposition, and egg hatching rate. The use of enzymes involved in glucose metabolism is a new strategy in the development of anti-tick vaccines.

Evaluation of Trophic Structure and Energy Flow in a Pelteobagrus fulvidraco Integrated Multi-Trophic Aquaculture System.

An integrated multi-trophic aquaculture system (IMTA) combined muti-trophic organism cultivation with ecological engineering facilities effectively improves energy utilization efficiency and reduces pollution emission, which promotes the development of the aquaculture industry. In this study, an Ecopath model was used to analyze the Pelteobagrus fulvidraco-integrated multi-trophic aquaculture system (FMRP). The results showed that the effective trophic level range of FMRP was low (1~2.566), and the energy throughput was mainly concentrated in trophic level I (65.39%). The utilization rate of commercial fish feed was high. Due to the lack of predators for detritus and primary producers (Oryza sativa L. and hydrophyte), the energy throughput of detritus and the primary production were not fully utilized. The ascendency/total development capacity (A/TDC) and overhead/total development capacity (O/TDC) were 0.29 and 0.59, respectively, which indicated that the aquaculture system had high elasticity and strong anti-perturbation ability, but the stability could be substantially improved. The results of the carrying capacity assessment showed that the maximal single increments of Pelteobagrus fulvidraco fry and juvenile were 0.12 g/m2 and 0.42 g/m2, respectively, and the maximal common increments of Pelteobagrus fulvidraco fry and juvenile were 0.10 g/m2 and 0.10 g/m2, respectively, which indicated that there was insufficient space for increment. The study showed that the FMRP still needed to be improved in the aspects of polyculture species, energy consumption and stability. It would be necessary for the FMRP to perform further optimization and enhancement on the energy utilization efficiency, system stability and comprehensive benefits.

Factors influencing the burden on spousal caregivers of breast cancer survivors.

PURPOSE: To examine the status of spouses' burdens of caring for breast cancer survivors and explore the relationships between social support, family resilience, breast cancer survivors' individual resilience, and caregiver burden. METHODS: A cross-sectional study on 315 young and middle-aged breast cancer survivors and their spousal caregivers was conducted at eight comprehensive Southwest China hospitals. The caregivers completed the Chinese Version of the Family Resilience Assessment Scale, the Perceived Social Support Scale, and the Zarit Caregiver Burden Interview, while breast cancer survivors completed the shortened Chinese version of the Connor-Davidson Resilience Scale. Structural equation modeling was used to evaluate the relationships among social support, family resilience, survivors' individual resilience, and caregiver burden. RESULTS: Caregiver burden (45.76 ± 14.66) was found to be severe. Social support, family resilience, and individual resilience were significantly negatively associated with caregiver burden (ß = - 0.421, P < 0.001; ß = - 0.208, P < 0.001; and ß = - 0.444, P < 0.001, respectively). Individual resilience not only partially mediated the relationship between family resilience and caregiver burden (b = - 0.052; 95% confidence interval, - 0.110, - 0.018), but also partially mediated the relationship between support and caregiver burden (b = - 0.045; 95% confidence interval, - 0.102, - 0.011). CONCLUSIONS: The findings suggest that higher social support, family resilience, and individual resilience tend to ease caregivers' burden. Healthcare workers should have an in-depth understanding of the care needs of survivors, actively contact social security departments and social organizations to provide financial, technical, and emotional support, and provide family-based care-skills training and psychological counseling to reduce spousal caregivers' burdens.

Evaluation on two types of paramyosin vaccines for the control of Haemaphysalis longicornis infestations in rabbits.

BACKGROUND: Haemaphysalis longicornis is an obligate hematophagous ectoparasite that transmits a variety of pathogens causing life-threatening diseases in humans and animals. Paramyosin (Pmy) is not only an invertebrate-specific myofibrillar protein but also an important immunomodulatory protein. Therefore, it is one of the ideal candidate antigens for vaccines. METHODS: We conducted two vaccine trials to evaluate the protective efficacy of Pmy recombinant protein (rPmy) and peptide vaccine (KLH-LEE). Each rabbit was immunized with three doses of rPmy or KLH-LEE adjuvanted with Freund's complete/incomplete at 500 µg/dose at 2-week intervals before challenge with 40 female H. longicornis/rabbit. PBS plus adjuvant, Trx or KLH was used as control group. The antibodies of rabbits were detected by ELISA. Then, female ticks were fed on the rabbits until detachment. RESULTS: ELISA results showed that both vaccines induced rabbits to produce antibodies. Compared with the Trx group, the engorgement weight, oviposition and hatchability of the rPmy group decreased by 8.87%, 26.83% and 38.86%, respectively. On the other hand, engorgement weight, oviposition and hatchability of female ticks in the KLH-LEE group correspondingly resulted in 27.03%, 53.15% and 38.40% reduction compared with that of the KLH group. Considering the cumulative effect of vaccination on the evaluated parameters, results showed 60.37% efficacy of the rPmy vaccine formulation and 70.86% efficacy in the KLH-LEE group. CONCLUSIONS: Pmy and particularly epitope LEE have potential for further development of an effective candidate vaccine to protect the host against tick infection. GRAPHIC ABSTARCT.

Gene cloning, analysis and effect of a new lipocalin homologue from Haemaphysalis longicornis as a protective antigen for an anti-tick vaccine.

Haemaphysalis longicornis is distributed worldwide and transmits a variety of pathogens, causing human and animal disease. Use of chemical acaricides, as a primary tick control method, has several disadvantages, including acaricide resistance, environmental damage and residue accumulation in livestock. Development of a livestock vaccination aimed at a tick protective antigen could be an effective, labor-saving and environmentally-friendly method of reducing tick infestation and transmission of tick-borne pathogens. Lipocalins are low molecular weight proteins that play important roles in blood feeding, immune response and reproduction in ticks. In our study, the open reading frame (ORF) of a lipocalin homologue from H. longicornis (HlLIP) was successfully cloned, which consisted of 387 bp encoding a protein of 128 amino acids. The HlLIP protein sequence showed a close sequence homology with Ixodes persulcatus lipocalin. The HlLIP gene was constitutively detected in all developmental stages and in all tissues of the unfed female tick. The ORF of the HlLIP gene was sub-cloned into pET-32a (+) to obtain the recombinant protein (rHlLIP) and its immunogenicity was comfirmed by western blot. A vaccination trial on rabbits against H. longicornis infestation demonstrated that the rHlLIP protein could significantly prolong the period of tick blood feeding, and reduce tick engorged weight, oviposition and egg hatching rate. The vaccination efficacy of the rHlLIP protein was 60.17 % based on engorged weight, oviposition and egg hatching rate of ticks. The results obtained in this study demonstrate that rHlLIP protein is a promising antigen that could potentially be developed as a vaccine against H. longicornis infestation.

Highly efficient selective hydrogenation of levulinic acid to γ-valerolactone over Cu-Re/TiO2 bimetallic catalysts.

Highly active and thermally stable Cu-Re bimetallic catalysts supported on TiO2 with 2.0 wt% loading of Cu were prepared via an incipient wetness impregnation method and were applied for liquid phase selective hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) in H2. The effect of the molar ratios of Cu : Re on the physico-chemical properties and the catalytic performance of the Cu-Re/TiO2 catalysts was investigated. Moreover, the influence of various reaction parameters on the hydrogenation of LA to GVL was studied. The results showed that the Cu-Re/TiO2 catalyst with a 1 : 1 molar ratio of Cu to Re (Cu-Re(1 : 1)/TiO2) exhibited the highest performance for the reaction. Complete conversion of LA with a 100% yield of GVL was achieved in 1,4-dioxane solvent under the reaction conditions of 180 °C, 4.0 MPa H2 for 4 h, and the catalyst could be reused at least 6 times with only a slight loss of activity. Combined with the characterization results, the high performance of the catalyst was mainly attributed to the well-dispersed Cu-Re nanoparticles with a very fine average size (ca. 0.69 nm) and the co-presence of Cu-Re bimetal and ReO x on the catalyst surface.

The Effects of Gold Nanoparticles on Leydig Cells and Male Reproductive Function in Mice.

BACKGROUND: Gold nanoparticles (AuNPs) have shown great promise in various biomedical applications, but their effects on male reproductive function remain to be ascertained. The aim of this study was to investigate the uptake, cytotoxicity and testosterone production inhibition of AuNPs in mouse Leydig cells, as well as their accumulation in the testes of male mice and their effects on male reproductive function. RESULTS: AuNPs (5 nm) were able to be internalized into the endosomes/lysosomes of TM3 Leydig cells, induce the formation of autophagosomes, increase the production of reactive oxygen species (ROS), and disrupt the cell cycle in S phase, resulting in concentration-dependent cytotoxicity and DNA damage. Interestingly, AuNPs significantly reduced testosterone production in TM3 cells by inhibiting the expression of 17α-hydroxylase, an important enzyme in androgen synthesis. After repeated intravenous injection, AuNPs gradually accumulated and retained in the testes of male BALB/c mice in a dose-dependent manner. One week after withdrawal, the level of plasma testosterone in the 0.5 mg/kg AuNPs group was significantly reduced compared to that in the PBS control group, accompanied by the decreased expression of 17α-hydroxylase in the testes. In addition, AuNPs treatment significantly increased the rate of epididymal sperm malformation, but without affecting fertility. CONCLUSION: Our results suggest that AuNPs can accumulate in the testes and reduce testosterone production in Leydig cells by down-regulating the expression of 17α-hydroxylase, thus affecting the quality of epididymal sperm.

Query-biased Self-attentive Network for Query-focused Video Summarization.

This paper addresses the task of query-focused video summarization, which takes user queries and long videos as inputs and generates query-focused video summaries. Compared to video summarization, which mainly concentrates on finding the most diverse and representative visual contents as a summary, the task of query-focused video summarization considers the user's intent and the semantic meaning of generated summary. In this paper, we propose a method, named query-biased self-attentive network (QSAN) to tackle this challenge. Our key idea is to utilize the semantic information from video descriptions to generate a generic summary and then to combine the information from the query to generate a query-focused summary. Specifically, we first propose a hierarchical self-attentive network to model the relative relationship at three levels, which are different frames from a segment, different segments of the same video, textual information of video description and its related visual contents. We train the model on video caption dataset and employ a reinforced caption generator to generate a video description, which can help us locate important frames or shots. Then we build a query-aware scoring module to compute the query-relevant score for each shot and generate the query-focused summary. Extensive experiments on the benchmark dataset demonstrate the competitive performance of our approach compared to some methods.

Open-Ended Video Question Answering via Multi-Modal Conditional Adversarial Networks.

As a challenging task in visual information retrieval, open-ended long-form video question answering automatically generates the natural language answer from the referenced video content according to the given question. However, the existing video question answering works mainly focus on the short-form video, which may be ineffectively applied for long-form video question answering directly, due to the insufficiency of modeling the semantic representation of long-form video content. In this paper, we study the problem of open-ended long-form video question answering from the viewpoint of hierarchical multimodal conditional adversarial network learning. We propose the hierarchical attentional encoder network to learn the joint representation of long-form video content and given question with adaptive video segmentation. We then devise the reinforced decoder network to generate the natural language answer for openended video question answering with multi-modal conditional adversarial network learning. We construct three large-scale open-ended video question answering datasets. The extensive experiments validate the effectiveness of our method.

Long-Form Video Question Answering via Dynamic Hierarchical Reinforced Networks.

Open-ended long-form video question answering is a challenging task in visual information retrieval, which automatically generates a natural language answer from the referenced long-form video contents according to a given question. However, the existing works mainly focus on short-form video question answering, due to the lack of modeling semantic representations from long-form video contents. In this paper, we introduce a dynamic hierarchical reinforced network for open-ended long-form video question answering, which employs an encoder-decoder architecture with a dynamic hierarchical encoder and a reinforced decoder. Concretely, we first propose a frame-level dynamic long-short term memory (LSTM) network with binary segmentation gate to learn frame-level semantic representations according to the given question. We then develop a segment-level highway LSTM network with a question-aware highway gate for segment-level semantic modeling. Furthermore, we devise the reinforced decoder with a hierarchical attention mechanism to generate natural language answers. We construct a large-scale long-form video question answering dataset. The extensive experiments on the long-form dataset and another public short-form dataset show the effectiveness of our method.

Size- and cell type-dependent cellular uptake, cytotoxicity and in vivo distribution of gold nanoparticles.

BACKGROUND: Gold nanoparticles (AuNPs) have shown great promise in biomedical applications. However, the interaction of AuNPs with biological systems, its underlying mechanisms and influencing factors need to be further elucidated. PURPOSE: The aim of this study was to systematically investigate the effects of particle size on the uptake and cytotoxicity of AuNPs in normal cells and cancer cells as well as their biological distribution in vivo. RESULTS: Our data demonstrated that the uptake of AuNPs increased in HepG2 cancer cells but decreased in L02 normal cells, with the increase of particle size (5-50 nm). In both cancer cells and normal cells, small (5 nm) AuNPs exhibited greater cytotoxicity than large ones (20 and 50 nm). Interestingly, 5 nm AuNPs induced both apoptosis and necrosis in HepG2 cells through the production of reactive oxygen species (ROS) and the activation of pro-caspase3, whereas it mainly induced necrosis in L02 cells through the overexpression of TLR2 and the release of IL-6 and IL-1a cytokines. Among them, 50 nm AuNPs showed the longest blood circulation and highest distribution in liver and spleen, and the treatment of 5 nm AuNPs  but not 20 nm and 50 nm AuNPs resulted in the increase of neutrophils and slight hepatotoxicity in mice. CONCLUSION: Our results indicate that the particle size of AuNPs and target cell type are critical determinants of cellular uptake, cytotoxicity and underlying mechanisms, and biological distribution in vivo, which deserves careful consideration in the future biomedical applications.