The environmental analysis and site selection of mussel and large yellow croaker aquaculture areas based on high resolution remote sensing

Mussel aquaculture and large yellow croaker aquaculture areas and their environmental characteristics in Zhoushan were analyzed using satellite data and in-situ surveys.A new two-step remote sensing method was proposed and applied to determine the basic environmental characteristics of the best mussel and large yellow croaker aquaculture areas.This methodology includes the first step of extraction of the location distribution and the second step of the extraction of internal environmental factors.The fishery ranching index(FRI1,FRI2)was established to extract the mussel and the large yellow croaker aquaculture area in Zhoushan,using Gaofen-1(GF-1)and Gaofen-6(GF-6)satellite data with a special resolution of 2 m.In the second step,the environmental factors such as sea surface temperature(SST),chlorophyll a(Chl-a)concentration,current and tide,suspended sediment concentration(SSC)in mussel aquaculture area and large yellow croaker aquaculture area were extracted and analyzed in detail.The results show the following three points.(1)For the extraction of the mussel aquaculture area,FRI1 and FRI2 are complementary,and the combination of FRI1 and FRI2 is suitable to extract the mussel aquaculture area.As for the large yellow croaker aquaculture area extraction,FRI2 is suitable.(2)Mussel aquaculture and the large yellow croaker aquaculture area in Zhoushan are mainly located on the side near the islands that are away from the eastern open waters.The water environment factor template suitable for mussel and large yellow croaker aquaculture was determined.(3)This two-step remote sensing method can be used for the preliminary screening of potential site selection for the mussels and large yellow croaker aquaculture area in the future.the fishery ranching index(FRI1,FRI2)in this paper can be applied to extract the mussel and large yellow croaker aquaculture areas in coastal waters around the world.

Study of coexisting upstream solitary wave packet and downstream wakes induced by Diaoyu Dao and its affiliated islands detected by satellite sun glitter

Taking the advantage of sun glitter(SG)observed from high-resolution satellites Gaofen-1(GF-1)and Gaofen-6(GF-6),a new method named Shield and Vortex 1-2(SAV1-2)for extracting spatial texture information from sun glitter was established.Sea surface texture detail information around Diaoyu Dao and its affiliated islands was extracted using SAV1-2.Meanwhile,the dynamic characteristics of the water environment were analyzed by combining the water color,temperature and dynamic data.The results show the following information.(1)Stable westward shield effect and eastward Karman vortex streets,extracted from SG,appear upstream(westward)and downstream(eastward)of the Diaoyu Dao and its affiliated islands respectively.(2)The dominant direction of the Kuroshio Current in the Diaoyu Dao and its affiliated islands area is east,the Diaoyu Dao and its affiliated islands interacting with Kuroshio,inducing western shield and eastern shelter and wake.Furthermore,wave intervals of the shield in front of the island range from hundreds to thousands of metres,and extend wider than the island itself.(3)Combining with high-resolution sea surface temperature(SST)and chlorophyll a(Chl a)concentration,the directional changes of water color elements are mutually supported and proved with the stable shield(wave packet)effect in the west and vortex street effect in the east.The change of SST upstream of the island(western shield area)is not significant,the temperature in the downstream shelter area decreases slightly,and the SST in the downstream wake area shows a general trend of obvious decrease.The wake area is dominated by Karman vortex streets in shape,supplementing by vortices.The concentration of Chl a in the west shield of island is as low as that in downstream shelter area,while it increases significantly in the downstream wake area with shape in eddy or ribbon.(4)The SAV methods of extracting sea surface texture detail using SG can be widely used in different sea areas and water quality.This paper can provide reference for the protection and development of Diaoyu Dao and its affiliated islands and its surrounding waters.It is suggested that some kind of current buffer,such as marine wind farm,should be established in the western waters of Diaoyu Dao and its affiliated islands to protect the islands,and marine pasture should be developed in the downstream of eastern waters of Diaoyu Dao and its affiliated islands.

Carnosine concentration and expression profiles of carnosine related genes in Mytilus after beta-alanine injection

Carnosine and its analogues are histidine-containing dipeptides(HCDs)playing diverse functions in vertebrates.However,the distribution and the metabolism of carnosine in invertebrates are still unknown.In this study,Mytilus coruscus,a shellfish with important economic value in China,was selected for the investigation of HCD content and the expression profiling of carnosine-related genes in various mussel tissues.Quantification of HCD by amino acids analyzer revealed a low concentration of anserine in muscular tissues in Mytilus,indicating the presence of HCD even in an invertebrate.mRNA expression of five carnosine metabolic-related genes was profiled in various tissues,and the results highlighted the relative higher expression level of these genes in muscular tissues.Considering the fact that beta-alanine supplementation can increase the HCD content in vertebrates,a beta-alanine injection was performed and the changes of HCD concentration and the mRNA expression of carnosine related genes were investigated in five mussel tissues.The results revealed the increase of HCD concentration,as well as the up-regulated expression level of related genes,in tested tissues of beta-alanine injected mussels.Transcriptomic analysis for the whole soft tissue of mussel before and after beta-alanine injection were performed,and 3569 differential expression genes(DEGs)were identified in the beta-alanine injected group when compared to their expression levels in the control.These data indicated the complex eff ects of betaalanine on M.coruscus metabolism,and those DEGs enriched in pathways of cancers,muscle contraction,and tyrosine metabolism highlighted the possible functions of beta-alanine in cell proliferation,sports,and melanogenesis,respectively.

HY-1C Coastal Zone Imager observations of the suspended sediment content distribution details in the sea area near Hong Kong-Zhuhai-Macao Bridge in China

The impacts of the Hong Kong-Zhuhai-Macao Bridge(HKZMB)on suspended sediment content(SSC)were analysed in the Zhujiang River Estuary based on data from HY-1C,which was launched in September 2018 in China,carrying Coastal Zone Imager(CZI)and Chinese Ocean Color and Temperature Scanner on it.A new SSC inversion model was established based on the relationship between in-situ SSC and the remote sensing reflectance in red and near-infrared bands of CZI image.HY-1C satellite data obtained from October to December 2019 were applied to retrieve SSC in the Zhujiang River Estuary.The results show that SSC around the HKZMB is ranging from 20 mg/L to 95 mg/L.SSC change obviously on two sides of the bridge.During flooding and ebbing period,SSC increases obviously downstream of the bridge.SSC difference between upstream and downstream is ranging from 5 mg/L to 20 mg/L.Currents flowing across the HKZMB,the change trend of SSC in most places upstream and downstream is almost the same that SSC downstream of the bridge is higher than SSC upstream.The tidal currents interact with bridge piers,inducing vortexes downstream,leading the sediment to re-suspend downstream of the bridge piers.Other factors,including seafloor topography and wind,can also contribute to the distribution of SSC in the Zhujiang River Estuary.

Zooplankton community size-structure change and mesh size selection under the thermal stress caused by a power plant in a semi-enclosed bay

Zooplankton samples were collected using 505, 160 and 77 μm mesh nets around a power plant during four seasons in 2011. We measured total length of zooplankton and divided zooplankton into seven size classes in order to explore how zooplankton community size-structure might be altered by thermal discharge from power plant. The total length of zooplankton varied from 93.7 to 40 074.7 μm. The spatial distribution of mesozooplankton(200-2 000 μm) populations were rarely affected by thermal discharge, while macro-(2 000-10 000 μm)and megalo-zooplankton(>10 000 μm) had an obvious tendency to migrate away from the outfall of power plant.Thus, zooplankton community tended to become smaller and biodiversity reduced close to power plant.Moreover, we compared the zooplankton communities in three different mesh size nets. Species richness,abundance, evenness index and Shannon-Wiener diversity index of the 505 μm mesh size were significantly lower than those recorded from the 160 and 77 μm mesh size. Average zooplankton abundance was highest in the 77 μm mesh net((27 690.0±1 633.7) ind./m^3), followed by 160 μm mesh net((9 531.1±1 079.5) ind./m^3), and lowest in 505 μm mesh net((494.4±104.7) ind./m^3). The ANOSIM and SIMPER tests confirmed that these differences were mainly due to small zooplankton and early developmental stages of zooplankton. It is the first time to use the 77 μm mesh net to sample zooplankton in such an environment. The 77 μm mesh net had the overwhelming abundance of the copepod genus Oithona, as an order of magnitude greater than recorded for 160 μm mesh net and 100% loss through the 505 μm mesh net. These results indicate that the use of a small or even multiple sampling net is necessary to accurately quantify entire zooplankton community around coastal power plant.

Engineering two-dimensional pores in freestanding TiO_2/graphene gel film for high performance lithium ion battery

As the key component of electrochemical energy storage devices, an electrode with superior ions transport pores is the important premise for high electrochemical performance. In this paper, we developed a unique solution process to prepare freestanding TiO_2/graphene hydrogel electrode with tunable density and porous structures. By incorporating room temperature ionic liquids（RTILs）, even upon drying, the non-volatile RTILs that remained in the gel film would preserve the efficient ion transport channels and prevent the electrode from closely stacking, to develop dense yet porous structures. As a result, the dense TiO_2/graphene gel film as an electrode for lithium ion battery displayed a good gravimetric electrochemical performance and more importantly a high volumetric performance.

Controlled flight of a self-powered micro blimp driven by insect-sized flapping-wing thrusters

Micro aerial platforms face significant challenges in achieving long controlled endurance as most of the energy is consumed to overcome the weight of the body.In this study,we present a controllable micro blimp that addresses this issue through the use of a helium-filled balloon.The micro blimp has a long axis of 23 cm and is propelled by four insect-sized flapping-wing thrusters,each weighing 80 mg and with a wingspan of 3.5 cm.These distributed thrusters enable controlled motions and provide the micro blimp with an advantage in flight endurance compared to multirotors or flapping-wing micro aerial vehicles at the same size scale.To enhance the performance of the controlled flight,we propose a wireless control module that enables manipulation from a distance of up to 100 m.Additionally,a smartphone application is developed to send instructions to the circuit board,allowing the blimp to turn left and right,ascend and descend,and achieve a combination of these movements separately.Our findings demonstrate that this micro blimp is one of the smallest controlled self-powered micro blimps to date.

Tissue-engineered mesenchymal stem cell constructs alleviate tendinopathy by suppressing vascularization

Tendinopathy leads to low-grade tissue inflammation and chronic damage,which progresses due to pathological imbalance in angiogenesis.Reducing early path-ological vascularization may be a new approach in helping to regenerate tendon tissue.Conventional stem cell therapy and tissue engineering scaffolds have not been highly effective at treating tendinopathy.In this study,tissue engineered stem cells(TSCs)generated using human umbilical cord mesenchymal stem cells(hUC-MSCs)were combined with microcarrier scaffolds to limit excessive vascularization in tendinopathy.By preventing VEGF receptor activation through their paracrine function,TSCs reduced in vitro angiogenesis and the proliferation of vascular endothelial cells.TSCs also decreased the inflammatory expression of tenocytes while promoting their anabolic and tenogenic characteristics.Furthermore,local injection of TSCs into rats with collagenase-induced tendinopathy substantially reduced early inflammation and vascularization.Mechanistically,transcriptome sequencing revealed that TSCs could reduce the progression of pathological angiogenesis in tendon tissue,attributed to Rap1-mediated vascular inhibition.TSCs may serve as a novel and practical approach for suppressing tendon vascularization,and provide a promising therapeutic agent for early-stage clinical tendinopathy.

The repression of oncoprotein SET by the tumor suppressor p53 reveals a p53-SET-PP2A feedback loop for cancer therapy

The oncoprotein SET is frequently overexpressed in many types of tumors and contributes to malignant initiation and progression through multiple mechanisms,including the hijacking of the tumor suppressors p53 and PP2A.Targeting aberrant SET represents a promising strategy for cancer intervention.However,the mechanism by which endogenous SET is regulated in cancer cells remains largely unknown.Here,we identified the tumor suppressor p53 as a key regulator that transcriptionally repressed the expression of SET in both normal and cancer cells.In addition,p53 stimulated PP2A phosphatase activity via p53-mediated transcriptional repression of SET,whereby SET-mediated inhibition of PP2A was alleviated.Moreover,targeting the interaction between SET and PP2A catalytic subunit(PP2Ac)with FTY720 enhanced stress-induced p53 activation via PP2A-mediated dephosphorylation of p53 on threonine 55(Thr55).Therefore,our findings uncovered a previously unknown p53-SETPP2A regulatory feedback loop.To functionally potentiate this feedback loop,we designed a combined therapeutic strategy by simultaneously administrating a p53 activator and SET antagonist in cancer cells and observed a dramatic synergistic effect on tumor suppression.Our study reveals mechanistic insight into the regulation of the oncoprotein SET and raises a potential strategy for cancer therapy by stimulating the p53-SET-PP2A feedback loop.

Passive attitude stabilization of ionic-wind-powered micro air vehicles

The ionic-wind-powered Micro Air Vehicles(MAVs)can achieve a higher thrust-toweight ratio than other MAVs.However,this kind of MAV has not yet achieved controlled flight because of the unstable thrust produced by the ionic wind and the dynamic instability related to the small size.In this paper,a passive attitude stabilization method of the ionic-wind-powered MAV using air dampers is introduced.The key factors that influence the performance of the air dampers,including the layout,position,and area of the air dampers,are theoretically studied.The appropriate optimal position of the air dampers is also obtained by Monte Carlo stochastic simulations.Then the proposed passive attitude stabilization method is applied to the ionic-wind-powered MAVs of different wingspan(2 cm and 6.3 cm).Finally,the experimental results show that using the proposed method,attitude stabilization is achieved for the first time for the ionic-wind-powered MAV.Moreover,the altitude control of an ionic-wind-powered MAV with a wingspan of 6.3 cm is also demonstrated.

Biomaterials as carrier, barrier and reactor for cell-based regenerative medicine

Cell therapy has achieved tremendous success in regenerative medicine in the past several decades. However, challenges such as cell loss, death and immune-rejection after transplantation still persist. Bio- materials have been designed as carriers to deliver cells to desirable region for local tissue regeneration; as barriers to protect transplanted cells from host immune attack; or as reactors to stimulate host cell recruitment, homing and differentiation. With the assistance of bio- materials, improvement in treatment efficiency has been demonstrated in numerous animal models of degener- ative diseases compared with routine free cell-based therapy. Emerging clinical applications of biomaterial assisted cell therapies further highlight their great pro- mise in regenerative therapy and even cure for complex diseases, which have been failed to realize by conven- tional therapeutic approaches.

The effects of DS blade's geometry features on material's creep strength

Because of the better creep performance,the directional solidification(DS)Nickel-based turbine blades have been widely used in advanced aero-engines.However,the DS turbine blade's different abrupt geometrical changes at different regions cause a variation of temperature field at those regions.Subsequently,the variable temperature field is very likely to lead to a different grain structures at those different region,and those different grain structure finally give rise to a variation in material's creep performance at different region in DS turbine blade.To study the variation in creep strength among different regions of a DS turbine blade,this article designed and manufactured three types of DS specimens to simulate the geometry features of platform,shroud and body part of a typical DS turbine blade.Creep tests on these specimens were conducted under the stress level of 608 MPa and temperature of 850。C,the creep rupture life of platform-like and shroud-like specimens are 93%and 73%of body-like specimens'respectively,which support the assumption that there exists a certain variation in material's creep strength among different regions in DS turbine blades.The fracture positions of these specimens also support above conclusion.It is suggested that the material's creep strength variation among different locations of DS turbine blades should be considered in future turbine blade life design and prediction.

Moving Mechanism of a High-speed Insect-scale Microrobot via Electro-magnetically Induced Vibration

This paper presents the moving mechanism of a high-speed insect-scale microrobot via electromagnetically induced vibration of two simply supported beams.The microrobot,which has a body length of 12.3 mm and a total mass of 137 mg,can achieve reciprocating lift motion of forelegs without any intermediate linkage mechanisms due to the design of an obliquely upward body tilt angle.The gait study shows that the body tilt angle prevents the forelegs from swinging backward when the feet contact the ground,which results in a forward friction force applied on the feet.During forward movement,the microrobot utilizes the elastic deformation of the simply supported beams as driving force to slide forward and its forelegs and rear legs work as pivots alternatively in a way similar to the movement of soft worms.The gait analysis also indicates that the moving direction of the microrobot is determined by whether its body tilt angle is obliquely upward or downward,and its moving speed is also related to the body tilt angle and as well as the body height.Under an applied AC voltage of 4 V,the microrobot can achieve a moving speed at 23.2 cm s1(18.9 body lengths per second),which is comparable to the fastest speed(20 cm s-1 or 20 body lengths per second)among the published insect-scale microrobots.The high-speed locomotion performance of the microrobot validates the feasibility of the presented actuation scheme and moving mechanism.

Processing micrometer-sized particles in crumpled graphene network for freestanding membrane enabled by freeze casting

Graphene oxide(GO)is widely used in the construction and application of various 2 D membrane-based materials due to its unique colloidal structure.Herein,we demonstrate that micrometer-sized particles can make up freestanding membranes enabled by the extraordinary amphiphilic and polymer-like properties of graphene oxide through freeze casting.The 2 D macromolecule,GO could well wrap the particles for better uniformity and stability in either dispersion or membrane.Importantly,freeze casting plays an important role in avoiding the severe aggregation of micrometer-sized particles in the solventremoving process.After reduction,the membrane exhibits good electrical conductivity while maintaining its integral structure,which can be directly used as a freestanding binder-free electrode.This work provides a universal approach to fabricate freestanding membranes with various micrometersized materials for energy storage.