Transmission Dynamics and Optimal Control Strategies of a Hand-Foot-Mouth Disease Model with Treatment and Vaccination Interventions

In this article, the transmission dynamics of a Hand-Foot-Mouth disease model with treatment and vaccination interventions are studied. We calculated the basic reproduction number and proved the global stability of disease-free equilibrium when R0 R0 > 1. Meanwhile, we obtained the optimal control strategies minimizing the cost of intervention and minimizing the infected person. We also give some numerical simulations to verify our theoretical results.

Effect of diagenetic variation on the static and dynamic mechanical behavior of coral reef limestone

Coral reef limestone at different depositional depths and facies differ remarkably on the textural and mineralogical characteristics,owing to the complex sedimentary diagenesis.To explore the effects of pore structure and mineral composition associated with diagenetic variation on the mechanical behavior of reef limestone,a series of quasi-static and dynamic compression tests along with microscopic examinations were performed on the reef limestone at shallow and deep burial depths.It is revealed that the shallow reef limestone(SRL)is classified as a porous aragonite-type carbonate rock with high porosity(55.3±3.2)%and pore connectivity.In comparison,the deep reef limestone(DRL)is mainly composed of dense calcite-type calcium carbonate with low porosity(4.9±1.6)%and pore connectivity.The DRL strengthened and stiffened by the tight grain framework consistently displays much higher values of the dynamic compressive strength,elastic modulus,brittleness index,and specific energy absorption than those of the SRL.The gap between two types of limestone further increases with an increase in strain rate.It appears that the failure pattern of SRL is dominated by the inherent defects like weak bonding interfaces and growth lines,revealed by the intricate fracturing network and mixed failure.Likewise,although the preexisting megapores in DRL may affect the crack propagation on pore tips to a certain distance,it hardly alters the axial splitting failure of DRL under impacts.The stress wave propagation and attenuation in SRL is primarily controlled by the reflection and diffusion caused by plenty mesopores,as well as an energy dissipation in layer-wise pore collapse and adjacent grain crushing,while the stress wave in DRL is highly hinged on the insulation and diffraction induced by the isolated megapores.This process is accompanied by the energy dissipation behavior of inelastic deformation resulted from the pore-emanated microcracking.

The protective role of prebiotics and probiotics on diarrhea and gut damage in the rotavirus-infected piglets

Rotavirus is one of the pathogenic causes that induce diarrhea in young animals, especially piglets, worldwide. However, nowadays, there is no specific drug available to treat the disease, and the related vaccines have no obvious efficiency in some countries. Via analyzing the pathogenesis of rotavirus, it inducing diarrhea is mainly due to disturb enteric nervous system, destroy gut mucosal integrity, induce intracellular electrolyte imbalance, and impair gut microbiota and immunity. Many studies have already proved that prebiotics and probiotics can mitigate the damage and diarrhea induced by rotavirus infection in hosts. Based on these, the current review summarizes and discusses the effects and mechanisms of prebiotics and probiotics on rotavirus-induced diarrhea in piglets. This information will highlight the basis for the swine production utilization of prebiotics and probiotics in the prevention or treatment of rotavirus infection in the future.

Study on the Relationship between Structural Aspects and Aerodynamic Characteristics of Archimedes Spiral Wind Turbines

A combined experimental and numerical research study is conducted to investigate the complex relationship between the structure and the aerodynamic performances of an Archimedes spiral wind turbine(ASWT).Two ASWTs are considered,a prototypical version and an improved version.It is shown that the latter achieves the best aerodynamic performance when the spread angles at the three sets of blades areα_(1)=30°,α_(2)=55°,α3=60°,respectively and the blade thickness is 4 mm.For a velocity V=10 m/s,a tip speed ratio(TSR)=1.58 and 2,the maximum CP values are 0.223 and 0.263 for the prototypical ASWT and improved ASWT,respectively,and the maximum C_(P) enhancement is 17.93%.For V=10 m/s and TSR=2,the CP values of the prototypical ASWT and improved ASWT are 0.225 and 0.263,respectively,with an aerodynamic performance enhancement of 16.88%.Through mutual verification of the test outcomes and numerical results,it is concluded that the proposed approach can effectively lead to aerodynamic performance improvement.

The Results Observation on Adjuvant Chemotherapy with Microwave Hyperthermia and Stereotactic Radiotherapy in Retreated Elderly Patients with Advanced (III/IV Stage) Lung Cancer

Objective: To evaluate the significance of adjuvant chemotherapy and radiotherapy (Gamma-knife) in the elderly patients with retreated advance lung cancer. Methods 83 patients (age 50 to 81 years) with retreating advanced (III/IV stage) lung cancer were divided into three groups according to patients received treating by different methods. The cases were treated by synchronous chemo-radiotherapy (A group), sequentially chemo-radiotherapy (B group) and continuous systematized chemotherapy alone (C group). The systemic 3-dimensional orientation apparatus was used in radiotherapy. The chemotherapy regimen in combined radiotherapy was given by common first line regimen on lung cancer. The regimen of chemotherapy combated with whole body hyperthermia by using micro-wave on abodeman about 2 or 3 line was used in C group only. Results: The overall responses rates (RR) of A, B and C groups were 17.1%, 11.5% and 31.8%, but it was non-significance difference (P > 0.05). Overall responses rates (RR) of III and IV stage groups were 18.2% and 20.0%. The average overall survival time (OS) and median survival time (MST) of the patients treated by chemotherapy (C group) were highest about 14.2 and 9.3 months (respectively at A group 6.7 and 6.0 months. P < 0.01), in which B group was longer than A group (P < 0.05), and 95.5% CI value was not overlap. The total survival time of postoperative patients was longer in the various groups by different treated than that in non-operations. Conclusion: The rates (RR) of III and IV stage groups were non-significance difference. The higher of ORR, OS and MST in a few patients of re-treated advanced lung cancer was presented in case with treated by continuous system chemotherapy. There were survival superiority in initial postoperative patients groups by different treated. It is a profitable and effect treatment that the pure reasonable systemic chemotherapy was used for elderly case with advanced retreated lung cancer.

羧酸根功能化的PVP-CdS同质结及其高效的光催化析氢性能

光催化制氢是一种十分绿色、环保可持续的产氢方式。为了构建高效的光催化体系,对光催化剂进行表面修饰可以提高反应分子的吸附/活化的能力和电荷转移的效率。在本文中,我们通过γ-射线辐射还原法一步合成了聚乙烯吡咯烷酮包裹的硫化镉(P-CdS)同质结纳米粒子,之后通过室温下的碱化后处理,将P-CdS表面的PVP水解成为具有羧酸根和铵根的MPVP,而CdS的WZ-ZB同质结的晶体结构并未受到影响。一方面,由于MPVP在碱性溶液中的溶解度的提高,一部分MPVP溶解于溶液中,最终从MP-CdS表面去除,从而暴露出更多WZ-ZB同质结的活性位点。另一方面,水解后的MPVP保留在CdS表面,其羧酸根离子与CdS的配位作用,会影响到催化剂的价带结构,进而促进光催化析氢过程。在二者的协同作用下,当碱化NaOH浓度为1 mol·L^(-1)时,MP-CdS-3碱化样品的光催化析氢速率达到477μmol·g^(−1)·h^(−1),是未碱化样品的2倍。这种碱化后处理的策略简单且廉价,可以引申到合成一些PVP包裹的各类光催化剂的表面修饰当中,有利于促进硫化镉材料的光催化应用。

Lentinan administration alleviates diarrhea of rotavirus-infected weaned pigs via regulating intestinal immunity

Background:Lentinan(LNT)may regulate many important physiological functions of human and animals.This study aimed to verify whether LNT administration could relieve diarrhea via improving gut immunity in rotavirus(RV)-challenged weaned pigs.Methods:Twenty-eight weaned pigs were randomly fed 2 diets containing 0 or 84 mg/kg LNT product for 19 d(n=14).RV infection was executed on d 15.After extracting polysaccharides from LNT product,its major monosaccharides were analyzed.Then,LNT polysaccharide was used to administrate RV-infected IPEC-J2 cells.Results:Dietary LNT supplementation supported normal function of piglets even when infected with RV,as reflected by reduced growth performance loss and diarrhea prevalence,and maintained gut immunity(P<0.05).The polysaccharide was isolated from LNT product,which molecular weight was 5303 Da,and major monosaccharides included glucose,arabinose and galactose.In RV-infected IPEC-J2 cells,this polysaccharide significantly increased cell viability(P<0.05),and significantly increased anti-virus immunity via regulating pattern recognition receptors and host defense peptides(P<0.05).Conclusion:Those results suggest that LNT administration increases the piglets’resistance to RV-induced stress,likely by supporting intestinal immunity.

Effects of a multi-enzyme complex on growth performance,nutrient utilization and bone mineralization of meat duck

Background： Previous studies with broiler have shown dietary supplementation with multi-enzyme complex containing non-starch polysaccharides （NSP） degrading enzymes and phytase is efficient in releasing phosphorus （P）, calcium （Ca）, energy and amino acids from corn-soybean meal diets or corn-sorghum diets, hence compensating considerable levels of nutrients in formulation. Notwithstanding, such potentials have not been well defined in duck nutrition. Giving China being the largest duck producing country, we conducted this study to establish adequate specifications of major nutrients along with multi-enzyme complex to meat duck from day-old to slaughter, focusing on performance, utilization of nutrients and bone mineralization. Five dietary treatments were： Positive control （PC,T1）： the nutrients concentration of diet for 1 to 14 d of age were apparent metabolizable energy（AME） 2,800 kcal/kg, crude protein （CP）1 9.39%, Ca 0.85%, available phosphorus （avP） 0.42%; for 15 to 35 d of age these parameters were AME 2,900 kcal/kg, CP 16.47%,Ca 0.76%,avP 0.38%; Negative control 1（NC1,7-2）, the AME and digestible amino acids （DAA） were reduced by 70 kcal/kg and 2.0%, avP and Ca by 1.0 g/kg from PC diet; Negative control 2（NC2,T4）, the down- spec from PC diet was AME 100 kcal/kg, DAA 2.5%, avP 1.5 g/kg and Ca 1.2 g/kg; The enzyme complex was added at the same dosage （200 mL/1,000 kg） on NC1 （T3） and NC2 （T5） diets. Results： Comparing with the ducks fed on T1, T3 and T5 diets, the birds fed on NC2 diet showed the lowest （P 〈 0.05） body weight （ d 14 and 35）, feed intake （d 35）, tibia ash, Ca and P contents （d 14 and 35）, and the utilization of nutrients （P 〈 0.05）. The supplementation with the enzyme complex to the NC diets restored growth rate, utilization of nutrients and bone mineralization to the level of the PC diet, and increased AME by 60 kcal/kg and 117 kcal/kg, respectively for the NC1 and NC2 diets. Conclusion： These results suggest that down-spec AME by 100 kcal/kg, DAA by 2.5%, avP by 1.5 g/kg and Ca by 1.2 g/kg caused detrimental effects on duck performance compared with those fed on the PC diet, and these performance losses can be compensated by the addition of the multiple-enzyme complex.

Identifying genomic regions controlling ratoon stunting disease resistance in sugarcane(Saccharum spp.) clonal F_(1) population

The ratoon stunting disease (RSD) of sugarcane,caused by the bacterium Leifsonia xyli subsp.xyli,is one of the major concerns to sugarcane production and breeding programs worldwide.Due to no obvious external symptoms,RSD cannot be easily detected by the growers,hence has reduced the world’s sugarcane production significantly.This study aimed to identify quantitative trait loci (QTL) associated with RSD resistance and to assist in the development of linked molecular markers for marker-assisted breeding to minimize the reduction in sugarcane yield by the RSD infection.A set of 146 individuals derived from a self-crossing of CP80-1827 were evaluated for RSD resistance in a mechanically duplicated inoculated field trial from 2014 to 2017 using tissue blot immunoassay.Leveraging the genetic data and the four years phenotyping data of CP80-1827 selfing population,linkage map construction and QTL analysis were conducted based on clonal F_1 and F_2 mapping population types with GACD V.1.2 and Ici Mapping V.3.3,respectively.A total of 23 QTL associated with RSD resistance were identified,which explained 6%to13%of the phenotypic variation with the two types of software.A total of 82 disease resistance genes were identified by searching these 23 QTL regions on their corresponding regions on the Sorghum bicolor genome (44 genes),sugarcane R570 genome (20 genes),and S.spontaneum genome (18 genes),respectively.Compared with Ici Mapping V.3.3,GACD V.1.2 identified more major (6 vs.3) and stable QTL (2vs.0),and more disease resistance genes (51 vs.31),indicating GACD V.1.2 (clonal F_1 mapping type) is most likely to be more efficient than Ici Mapping (F_2 mapping type) for QTL analysis of a sefling population or clonal F_1 population in clonal species.The identified QTL controlling RSD resistance along with the associated SNP markers will assist sugarcane molecular breeding programs in combating this disease.

Threshold Dynamics of a Vector-Borne Epidemic Model for Huanglongbing with Impulsive Control

In this paper, the basic reproduction number is calculated for Huanglongbing (HLB) model with impulses which is a vector-borne epidemic model with impulses. For controlling HLB, farmers’ experience is replanting of healthy plants and removing infected plants. To reflect the real world, we construct an impulsive control model which considers replanting of healthy plants and removing infected plants at one fixed time. By analyzing the model, we conclude that the disease-free equilibrium is globally asymptotically stable if the basic reproduction number Ro 1, and we prove that the HLB is permanence if the basic reproduction number Ro > 1.

Separate Least Mean Square Based Equalizer with Joint Optimization for Multi-CAP Visible Light Communication

Visible light communication(VLC) is expected to be a potential candidate of the key technologies in the sixth generation(6G) wireless communication system to support Internet of Things(IoT) applications. In this work, a separate least mean square(S-LMS) equalizer is proposed to compensate lowpass frequency response in VLC system. Joint optimization is employed to realize the proposed S-LMS equalizer with pre-part and post-part by introducing Lagrangian. For verification, the performance of VLC system based on multi-band carrier-less amplitude and phase(m-CAP) modulation with S-LMS equalizer is investigated and compared with that without equalizer,with LMS equalizer and with recursive least squares(RLS)-Volterra equalizer. Results indicate the proposed equalizer shows significant improved bit error ratio(BER) performance under the same conditions. Compared to the RLS-Volterra equalizer, SLMS equalizer achieves better performance under low data rate or high signal noise ratio(SNR) conditions with obviously lower computational complexity.

Drimane sesquiterpenoids from a wetland soil-derived fungus Aspergillus calidoustus TJ403-EL05

Soil-derived fungi represent an insufficiently tapped reservoir for discovering new and bioactive natural products(NPs),and despite an ever-increasing number of unknown NPs have been discovered over the past few decades,much of the hidden biosynthetic potential is still in an urgent need to be disclosed.In this research,a chemical inves-tigation was performed on a wetland soil-derived fungus Aspergillus calidoustus TJ403-EL05,leading to the isolation of a total of fourteen drimane sesquiterpenoids(1-14),incorporating three new ones,namely ustusols F-H(1-3).Their structures,comprising absolute configurations,were completely authenticated by widespread spectroscopic data,quantum chemical 13C NMR and ECD calculations,and X-ray crystallography experiments.Compound 14 exhibited moderate anti-inflammatory activity by inhibiting the LPS-induced NO release(IC_(50)=25.6μM).

Integrated parallel forecasting model based on modified fuzzy time series and SVM

A dynamic parallel forecasting model is proposed, which is based on the problem of current forecasting models and their combined model. According to the process of the model, the fuzzy C-means clustering algorithm is improved in outliers operation and distance in the clusters and among the clusters. Firstly, the input data sets are optimized and their coherence is ensured, the region scale algorithm is modified and non-isometric multi scale region fuzzy time series model is built. At the same time, the particle swarm optimization algorithm about the particle speed, location and inertia weight value is improved, this method is used to optimize the parameters of support vector machine, construct the combined forecast model, build the dynamic parallel forecast model, and calculate the dynamic weight values and regard the product of the weight value and forecast value to be the final forecast values. At last, the example shows the improved forecast model is effective and accurate.

The structures of floral organs and reproductive characteristics of an ornamental bamboo species,Pleioblastus pygmaeus

As a woody grass,bamboo has special reproductive habits with an extremely long vegetative phase.Pleioblastus pygmaeus is a kind of ornamental dwarf bamboo species with high ecological and economic value in China.There was no documentary record of the flowering of P.pygmaeus until 2015,which bloomed in the Bamboo Garden of Nanjing Forestry University.Generally,bamboo plants rarely bear fruit or have a low seed setting rate,but this species has a high seed production.This study explores developmental reasons using anatomical methods.The process of flower bud differentiation and a series of important reproductive development processes including anther wall development,microsporogenesis,megasporogenesis,male and female gametophyte development,and embryonic development were investigated sequentially.Each stamen contained three tetrasporangiate anthers and the development of anther wall was of Monocotyledonous type.The microspores finally matured into 3-celled pollen grains by two successive mitoses.The pistil was composed of three carpels,with an anatropous,tenuinucellate and bitegmic ovule in a single ovary.The formation of embryo sac belonged to Polygonum type.With three mitoses,functional megaspore developed into the embryo sac with eight nuclei within seven cells.The development of stamen and pistil was synchronous in the same floret.The development of embryo followed Grass type and the development of endosperm belonged to Nuclear type.The development of endosperm was earlier than that of embryo.The study enriches basic knowledge of reproductive biology of bamboo plants and is of great fundamental significance to furtherly explore flowering mechanism of P.pygmaeus and to cultivate bamboo plants sustainably.

Physiological and anatomical changes in two rapeseed (Brassica napus L.) genotypes under drought stress conditions

Understanding the mechanisms of drought resistance in crop species is crucial for the selection and breeding of tolerant rapeseed(Brassica napus L.)varieties.The present study aimed to assess the physiological and anatomical responses of two rapeseed genotypes,P287(drought-tolerant)and T88(drought-sensitive)under three intensities of drought stress.All physiological and anatomical parameters related to drought acclimation were significantly altered in both genotypes under stress conditions.At the fourth-leaf stage,the relative water content,chlorophyll content,protein content,malondialdehyde content,and the activities of peroxidase and catalase in P287 were significantly higher than those in T88,particularly under severe drought conditions.After rehydration,all physiological indexes recovered rapidly,especially in P287.In addition,under drought stress,compared with T88,P287 had thicker palisade tissue,thinner spongy tissue,higher ratio of chloroplast length to chloroplast width,higher stomatal density and stomatal closure rate.Overall,the interaction between physiological and anatomical features improved the drought tolerance of P287 under drought stress conditions.

Fault Diagnosis of the LAMOST Fiber Positioner Based on a Long Short-term Memory(LSTM)Deep Neural Network

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST)has been in normal operation for more than 10 yr,and routine maintenance is performed on the fiber positioner every summer.The positioning accuracy of the fiber positioner directly affects the observation performance of LAMOST,and incorrect fiber positioner positioning accuracy will not only increase the interference probability of adjacent fiber positioners but also reduces the observation efficiency of LAMOST.At present,during the manual maintenance process of the positioner,the fault cause of the positioner is determined and analyzed when the positioning accuracy does not meet the preset requirements.This causes maintenance to take a long time,and the efficiency is low.To quickly locate the fault cause of the positioner,the repeated positioning accuracy and open-loop calibration curve data of each positioner are obtained in this paper through the photographic measurement method.Based on a systematic analysis of the operational characteristics of the faulty positioner,the fault causes are classified.After training a deep learning model based on long short-term memory,the positioner fault causes can be quickly located to effectively improve the efficiency of positioner fault cause analysis.The relevant data can also provide valuable information for annual routine maintenance methods and positioner designs in the future.The method of using a deep learning model to analyze positioner operation failures introduced in this paper is also of general significance for the maintenance and design optimization of fiber positioners using a similar double-turn gear transmission system.

Assessment of Serum PRL,MLT,TSH,FSH and LH Concentrations in the Goat (Capra hircus) Exposing to Different Photoperiod Regimes

In many seasonally breeding species, photoperiod is an important factor involved in reproduction. Capra hircus breeds are normally considered short-day breeders. An experiment was carried out to evaluate whether or not photoperiodic regimens influence circulating hormone levels （prolactin, melatonin, thyrotropin stimulating hormine, luteinizing hormone,follicle stimulating hormone） of Henan huai local goat exposing to different photoperiodic regimens. The results showed that plasma levels of prolactin, melatonin, thyrotropin stimulating hormine, luteinizing hormone and follicle stimulating hormone were higher in the 8 L∶ 16 D photoperiodic regimen than that in the 16 L∶ 8 D photoperiodic regimen. Levels of those hormones decreased on day 7 and day 28 when the 16 L∶ 8 D photoperiodic regimen was used continuously. It was concluded that serum concentrations of the hormones increased in summer when short day （8 L∶ 16 D） was used and decreased when the goats were transferred from short day for 42 d to long day exposure for 28 d. We suggest that in summer, levels of hormones changing may be due to short day animals. Changing of related hormones is still determined by the mechanism of internal regulation of short day animal s exposure to light changes. Shortening light may also help increase the reproductive activity of goat and thus increase productivity.

Effect of dietary canthaxanthin and 25-hydroxycholecalciferol supplementation on the performance of duck breeders under two different vitamin regimens

Background： Dietary canthaxanthin（CX）, 25-hydroxycholecalciferol（25-OH-D3） and vitamins have been widely reported to be involved in productive and reproductive performance of broiler breeders. However, limited information is available for duck breeders. In this study, a total of 1,560 Cherry Valley SM3 duck breeder females and 312 males were used to assess if the addition of CX and 25-OH-D3 could increase the performance of duck breeders under two different dietary vitamin regimens. Four diets were used under a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes（REGULAR and HIGH; HIGH premix had higher levels of all vitamins except K3 than REGULAR premix）, and with or without the supplementation of the mixture of CX（6 mg/kg） and 25-OH-D3（0.069 mg/kg）. The ducks were fed ad libitum with pelleted diets based on corn-soybean meal from 38 to 77 wk of age.Results： HIGH vitamin premix decreased malondialdehyde（MDA） level（P 〈 0.001） of egg yolk, increased hatchability of fertile eggs（P = 0.029）, increased hatchability of total eggs（P = 0.029）, and decreased serum protein carbonyl level（P = 0.037） of breeder males. The mixture of CX and 25-OH-D3 increased serum calcium of breeder females（P = 0.010）, decreased the cracked egg rate（P = 0.001）, increased the pigmentation of egg yolk（P 〈 0.001）and male bill（P 〈 0.001）, and decreased MDA level of egg yolk（P 〈 0.001） and male serum（P = 0.034）. Interactive effects were observed in cracked egg rate（P = 0.038）, shell thickness（P = 0.011） and serum phosphorus（P = 0.026）of breeder females. HIGH vitamin premix together with the mixture of CX and 25-OH-D3 decreased cracked egg rate and increased shell thickness of duck breeders. Serum phosphorus was decreased in duck breeder females fed REGULAR vitamin premix without the addition of the CX and 25-OH-D3 mixture.Conclusions： Dietary HIGH vitamin premix increased antioxidant status of eggs and breeder males, and increased hatchability. The mixture of CX and 25-OH-D3 enhanced egg shell quality, and promoted pigmentation and antioxidant status of eggs and breeder males.

Physiological and histological responses of Phascolosoma esculenta (Sipuncula: Phascolosomatidea) to acute heat stress

Temperature is an important factor affecting the growth,development,and survival of organisms.The effects of temperature stress on aquatic organisms have received increasing attention,as these organisms are mostly poikilotherms and their body temperature are directly corresponding changes with ambient temperature,resulting in they are easily exposed in temperature stress.However,little is known about the effects of high temperature on Sipuncula.In this study,we investigated the effects of acute heat stress on malondialdehyde(MDA)concentration,the activities of antioxidant(superoxide dismutase and glutathione peroxidase)and immunity-related(acidic and alkaline phosphatase)enzymes,heat shock protein 70(hsp70)and hsp90 gene expression,and the histological structure of the sipunculid Phascolosoma esculenta.Within the coelom fl uid,the MDA concentration and all detected antioxidant enzyme activities increased during high temperature stress;signifi cant increases were also observed here and in the intestine in the hsp70 and hsp90 mRNA expression levels.These results indicated that acute heat stress caused oxidative stress;antioxidants and heat shock proteins probably act to protect P.esculenta against oxidative damage,constituting part of its physiological mechanism for adaptation to high temperatures.In addition,the increased activity of the acidic and alkaline phosphatases indicated eff ects on its nonspecifi c immune system.Furthermore,damaged tissue structures were observed in the body wall,retractor muscle,intestine,and nephridium after 96 h of 40-℃ stress.The damaged cells of these tissues showed obvious condensed chromatin around the nuclear membrane.This histological damage suggests that heat stress could affect movement,food absorption,digestion,and excretion in P.esculenta.These results elucidate the effects of temperature stress on P.esculenta and its physiological response mechanisms and provide practical indicators for assessing heat stress status and determining suitable culture temperatures for P.esculenta.

Maternal organic selenium supplementation during gestation enhances muscle fiber area and muscle fiber maturation of offspring in porcine model

Background:Organic selenium supplementation during gestation improves the antioxidant status and reproduc-tive performance of sows and increases the antioxidative capacity of the intestines of their offspring.This study was conducted to investigate the effect of maternal basel diet(control)supplemented with an organic Se,2-hydroxy-4-methylselenobutanoic acid(HMSeBA),or inorganic sodium selenite(Na_(2)SeO_(3))during gestation on the antioxidant status and development of muscle in newborn and weaned piglets.Newborn piglets before colostrum intake and weaned piglets were selected for longissimus dorsi(LD)muscle collection and analysis.Results:The results showed that maternal HMSeBA supplementation increased the muscle area and content of Se in the LD muscle of newborn piglets,improved gene expression of selenoproteins,and decreased oxidative status in the LD muscle of both newborn and weaned piglets compared with the control.The expression of muscle development-related genes of newborn piglets in the HMSeBA group was lower than in the control group,whereas the expression of MRF4 in weaned piglets was higher in the HMSeBA group than in the control and Na_(2)SeO_(3)groups.In addition,HMSeBA supplementation decreased the mRNA expressions of myosin heavy chains(MyHC)IIx and MyHC IIb and the percentage of MyHC IIb;increased the expression of PGC-1αin the LD muscle of newborn piglets;increased the gene expression of MyHC IIa;and decreased the protein expression of slow MyHC and the activity of malate dehydrogenase in the LD muscle of weaned piglets compared with the control group.Conclusions:Maternal HMSeBA supplementation during gestation can improve the antioxidative capacity of the muscle of their offspring and promote the maturity of muscle fibres in weaned offspring.