The aging and declining birthrate is a common challenge faced by many countries in the world today,especially those with relatively developed economies.As close neighbors in East Asia,Japan and China are particularly ...The aging and declining birthrate is a common challenge faced by many countries in the world today,especially those with relatively developed economies.As close neighbors in East Asia,Japan and China are particularly prominent in this issue.Japan is one of the countries with the highest degree of aging globally,and its process is characterized by“getting rich first and aging later”;while China is known for its“aging before getting rich”and its ultra-large elderly population,and is experiencing a similar demographic transition at a faster pace.This paper aims to systematically compare the current characteristics of aging and declining birthrate issues in China and Japan,and deeply analyze the similarities and differences in the underlying economic,social,and cultural reasons.The study finds that the two countries are similar in overall trends such as low fertility rates and inverted population structures,but there are significant differences in the timing of the problem’s outbreak,its severity,and specific causes.Japan’s predicament is rooted in its long-term economic stagnation,mature welfare social system,and profound individualization trend;while China’s challenges are closely related to unique family planning policies,rapid socioeconomic changes,and significant urban-rural regional differences,as well as the deep penetration of the declining birthrate phenomenon from urban to rural areas,and the accelerated disintegration of traditional fertility concepts.展开更多
[Objective] The research aimed to provide theoretical basis for the cultivation and production of peach.[Method] The three-year-old seedling peach tree was used as the materials,and NH4NO3 was used as the experimental...[Objective] The research aimed to provide theoretical basis for the cultivation and production of peach.[Method] The three-year-old seedling peach tree was used as the materials,and NH4NO3 was used as the experimental nitrogen fertilizer.Three nitrogen levels,0,3,6 g per pot respectively were set to study the effects of different nitrogen fertilizer on the contents of soluble sugar,starch and internal structure of the root of the peaches.[Result] The contents of soluble sugar of roots and leaves increased with the increase of nitrogen fertilizer level,and the level of 6 g per pot was the highest,which showed extreme differences between the level of 3 g per pot and the control.However,starch contents showed opposite results,which decreased as the level of nitrogen fertilizer increased.Compared with the 3 g per pot level of nitrogen fertilizer and the control,the internal structure of root applied with nitrogen fertilizer of 6 g per pot level had larger fibrovascularcylinder,advanced vascular bundle,small-spaced thin-walled cells,smooth and full cells with smooth cell wall.[Conclusion]Appropriate nitrogen levels can accelerate the accumulation of soluble sugar and the growth of root tissue structure.展开更多
A growing global demand exists to formulate plans to lessen the greenhouse gas emissions produced by agricultural activities.The purpose of this study was to uncovered the changes in soil CO_(2)fluxes under varying sc...A growing global demand exists to formulate plans to lessen the greenhouse gas emissions produced by agricultural activities.The purpose of this study was to uncovered the changes in soil CO_(2)fluxes under varying scenarios including nitrogen fertilization rates,irrigation rates,and air temperatures in the Hetao Irrigation District(HID)over the 38-year period.DAYCENT model was used to predict carbon dioxide(CO_(2))fluxes from cultivated soils in the HID,Inner Mongolia from^(2)023 to 2060(the year of achieving the"carbon neutrality"goal)in this study.Results showed that mean soil CO_(2)fluxes in the sunflower field[1035.13 g/(m^(2).yr)]were significantly lower than those in the maize field[1405.54 g/(m^(2).yr)].An increase in nitrogen fertilization rate led to a significant escalation in soil CO_(2)fluxes.Moreover,elevating irrigation rates for washing salts by irrigation(WSBI)diminished soil CO_(2)fluxes in the sunflower field while amplifying them in the maize field.A rise in air temperature resulted in an increase in soil CO_(2)fluxes from the maize field,with annual increases observed,but a reduction in soil CO_(2)fluxes from the sunflower field.The sunflower fields in the HID have a more substantial advantage than the corn fields in mitigating soil CO_(2)emissions.展开更多
The longstanding debate persists:is the economy for the people,or are people for the economy?Technological advancements have increasingly reduced the need for physical human labor in economic activities.However,the de...The longstanding debate persists:is the economy for the people,or are people for the economy?Technological advancements have increasingly reduced the need for physical human labor in economic activities.However,the demand for human resources is expected to persist at some level.Historically,the necessary human resources for national economies have been sustained through birth rates or immigration.This study explores whether maintaining a stable fertility rate of 2.1 in modern EU member states can be achieved in the long term while adhering to constitutional and human rights standards.展开更多
Fertilizers are heavily applied in orchards of the hilly and mountainous topography of South China and may increase nutrient loadings to receiving waters.A simple runoff collecting system was used to measure the effec...Fertilizers are heavily applied in orchards of the hilly and mountainous topography of South China and may increase nutrient loadings to receiving waters.A simple runoff collecting system was used to measure the effects of different fertilization treatments on total N and P concentrations of surface runoff in a Chinese chestnut (Castanea mollissima Blume) orchard in Dongyuan County,Guangdong Province,China.In such orchards,fertilizer was typically applied in two short furrows or pits on either side of each tree.Treatments included three application depths (surface,10cm and 20 cm),and three application rates (low,median and high).Results showed that 90.5% of the runoff water samples had a total N concentration higher than 0.35 mgL^(-1) and 54.2% had a total P concentration higher than 0.1 mgL^(-1).Fertilizer application at all depths and at all but the lowest rate significantly increased total N and P concentrations in runoff water.Fertilization with chemical compound fertilizer at a soil depth of 20cm produced significantly lower (P<0.05) total N concentration in runoff than both surface and 10-cm depth fertilization,and significantly lower (P<0.05) total P concentration in runoff than surface fertilization.Total N and P concentrations in runoff significantly increased with the application rate of organic fertilizers.With the exception of total P concentrations,which were not significantly different between the control and fertilization at a rate of 119 kg P ha-1 in organic form,all the other fertilization treatments produced significantly higher total N and total P concentrations in runoff than the control.A fertilization depth≥20cm and an application rate≤72 kg N ha^(-1) or 119 kg P ha^(-1) for compound organic fertilizer was suggested to substantially reduce N and P runoff losses from hillslope orchards and to protect receiving waters in South China.展开更多
This paper studied the fertilizer rate(FR), fertilizer use efficiency(FUE) and fertilizer overuse rate(FOR) of rice, corn and wheat in China from 1998 to 2018 and briefly analysed the reasons why farmers were willing ...This paper studied the fertilizer rate(FR), fertilizer use efficiency(FUE) and fertilizer overuse rate(FOR) of rice, corn and wheat in China from 1998 to 2018 and briefly analysed the reasons why farmers were willing to apply more fertilizers.(1) The FR of grain in China reached 373.7 kg/ha in 2018, an increase of 26.8% compared to that in 1998. In 2018, the FR for corn was the highest, at 411.2 kg/ha, compared to the values of 338.3 kg/ha for rice and 371.7 kg/ha for wheat.(2) In recent years, the FUE of grain in China has obviously improved, with values of 32.9% in 1998, 36.7% in 2008, and 39.3% in 2018. In 2018, the FUE for rice was the highest(41.2%), followed by that for corn(39.9%), and the FUE for wheat was the lowest(36.0%).(3) By 2018, fertilizer was overused in all zones of rice, corn and wheat. In 2018, the average FOR for wheat reached 69.0%, which was 35.9% higher than that for corn and 42.8% higher than that for rice.(4) The lower price of chemical fertilizers was the main reason leading to overapplication.(5) Establishing market mechanisms and adjusting regional planting structures can be effective in reducing the application of chemical fertilizers.展开更多
Ammonia oxidation, the first and rate-limiting step of nitrification, is carried out by both ammonia-oxidizing bacteria （AOB） and ammonia-oxidizing archaea （AOA）. However, the relative importance of AOB and AOA to...Ammonia oxidation, the first and rate-limiting step of nitrification, is carried out by both ammonia-oxidizing bacteria （AOB） and ammonia-oxidizing archaea （AOA）. However, the relative importance of AOB and AOA to nitrification in terrestrial ecosystems is not well understood. The aim of this study was to investigate the effect of the nitrogen input amount on abundance and community composition of AOB and AOA in red paddy soil. Soil samples of 10-20 cm （root layer soil） and 0-5 cm （surface soil） depths were taken from a red paddy. Rice in the paddy was fertilized with different rates of N as urea of N1 （75 kg N ha＂ yr-1）, N2 （150 kg N ha~ yrl）, N3 （225 kg N ha1 yrl） and CK （without fertilizers） in 2009, 2010 and 2011. Abundance and community composition of ammonia oxidizers was analyzed by real-time PCR and denaturing gradient gel electrophoresis （DGGE） based on amoA （the unit A of ammonia monooxygenase） gene. Archaeal amoA copies in N3 and N2 were significantly （P〈0.05） higher than those in CK and N1 in root layer soil or in surface soil under tillering and heading stages of rice, while the enhancement in bacterial amoA gene copies with increasing of N fertilizer rates only took on in root layer soil. N availability and soil NO3--N content increased but soil NH4＋-N content didn＇t change with increasing of N fertilizer rates. Otherwise, the copy numbers of archaeal amoA gene were higher （P〈0.05） than those of bacterial amoA gene in root lary soil or in surface soil. Redundancy discriminate analysis based on DGGE bands showed that there were no obvious differs in composition of AOA or AOB communities in the field among different N fertilizer rates. Results of this study suggested that the abundance of ammonia-oxidizers had active response to N fertilizer rates and the response of AOA was more obvious than that of AOB. Similarity in the community composition of AOA or AOB among different N fertilizer rates indicate that the community composition of ammonia-oxidizers was relatively stable in the paddy soil at least in short term for three years.展开更多
Field experiments were conducted with five rates （0, 75, 150, 225, and 450 kg P205 ha^-1） of seedbed P fertilizer application to investigate the yield of tomato in response to fertilizer P rate on calcareous soils w...Field experiments were conducted with five rates （0, 75, 150, 225, and 450 kg P205 ha^-1） of seedbed P fertilizer application to investigate the yield of tomato in response to fertilizer P rate on calcareous soils with widely different levels of Olsen P （13-142 mg kg^-1） at 15 sites in some suburban counties of Beijing in 1999. Under the condition of no P fertilizer application, tomato yield generally increased with an increase in soil test P levels, and the agronomic level for soil testing P measured with Olsen method was 50 or 82 mg kg^-1 soil to achieve 85% or 95% of maximum tomato yield, respectively. With regard to marketable yield, in the fields where Olsen-P levels were 〈 50 mg kg^-1, noticeable responses to applied P were observed. On the basis of a linear plateau regression, the optimum seedbed P application rate in the P-insufflcient fields was 125 kg P205 ha^-1 or about 1.5-2 times the P removal from harvested tomato plants. In contrast, in fields with moderate （50 〈 Olsen P 〈 90 mg kg^-1） or high （Olsen P 〉 90 mg kg^-1） available P, there was no marked effect on tomato fruit yield. Field survey data indicated that in most fields with conventional P management, a P surplus typically occurred. Thus, once the soil test P level reached the optimum for crop yield, it was recommended that P fertilizer application be restricted or eliminated to minimize negative environmental effects.展开更多
The present study aimed to evaluate the clinical outcomes of magnetic-activated cell sorting(MACS)in sperm preparation for male subjects with a sperm DNA fragmentation index(DFI)≥30%.A total of 86 patients who had un...The present study aimed to evaluate the clinical outcomes of magnetic-activated cell sorting(MACS)in sperm preparation for male subjects with a sperm DNA fragmentation index(DFI)≥30%.A total of 86 patients who had undergone their first long-term long protocol were selected.The protocol involved in vitro fertilization(IVF)and intracytoplasmic sperm injection(ICSI)cycles,and the patients were divided into the MACS or control groups.The MACS group included sperm samples analyzed with MACS that were combined with density gradient centrifugation(DGC)and the swim-up(SU)technique(n=39),and the control group included sperm samples prepared using standard techniques(DGC and SU;n=41).No differences were noted with regard to basic clinical characteristics,number of oocytes retrieved,normal fertilization rate,cleavage rate,or transplantable embryo rate between the two groups in IVF/ICSI.In addition,the clinical pregnancy and implantation rates of the first embryo transfer cycles indicated no significant differences between the two groups.However,there was a tendency to improve the live birth rate(LBR)of the first embryo transfer cycle(63.2%vs 53.9%)and the cumulative LBR(79.5%vs 70.7%)in the MACS group compared with the control group.Moreover,the number of transferred embryos(mean±standard deviation[s.d.]:1.7±0.7 vs 2.3±1.6)and the transfer number of each retrieved cycle(mean±s.d.:1.2±0.5 vs 1.6±0.8)were significantly lower in the MACS group than those in the control group.Thus,the selection of nonapoptotic spermatozoa by MACS for higher sperm DFI could improve assisted reproductive clinical outcomes.展开更多
Excessive use of N fertilizer in intensive agriculture can increase crop yield and at the same time cause high carbon（C） emissions.This study was conducted to determine optimized N fertilizer application for high gr...Excessive use of N fertilizer in intensive agriculture can increase crop yield and at the same time cause high carbon（C） emissions.This study was conducted to determine optimized N fertilizer application for high grain yield and lower C emissions in summer corn（Zea mays L.）.A field experiment, including 0（N0）, 75（N75）, 150（N150）, 225（N225）, and 300（N300） kg N ha–1 treatments, was carried out during 2010–2012 in the North China Plain（NCP）.The results showed that grain yield, input energy, greenhouse gas（GHG） emissions, and carbon footprint（CF） were all increased with the increase of N rate, except net energy yield（NEY）.The treatment of N225 had the highest grain yield（10 364.7 kg ha–1） and NEY（6.8%）, but the CF（0.25） was lower than that of N300, which indicates that a rate of 225 kg N ha–1 can be optimal for summer corn in NCP.Comparing GHG emision compontents, N fertilizer（0–51.1%） was the highest and followed by electricity for irrigation（19.73–49.35%）.We conclude that optimazing N fertilizer application rate and reducing electricity for irrigation are the two key measures to increase crop yield, improve energy efficiency and decrease GHG emissions in corn production.展开更多
Effects of residues of 9 plants, lemon eucalyptus (Eucalyptus citriodoraHook., P_1), robust eucalyptus (E. robusta Smith, P_2), Nepal camphortree (Cinnamomum glanduliferum(Wall.) Nees, P_3), tea (Camellia sinensis (Li...Effects of residues of 9 plants, lemon eucalyptus (Eucalyptus citriodoraHook., P_1), robust eucalyptus (E. robusta Smith, P_2), Nepal camphortree (Cinnamomum glanduliferum(Wall.) Nees, P_3), tea (Camellia sinensis (Linn.) O. Ktze. f., P_4), oleander (Nerium indicum Mill,P_5), rape (Brassica campestris L., P_g), Chinese tallow tree (Sapium sebiferum L., P_7), tung(Vernicia fordii (Hemsl.), P_8), and croton (Croton tiglium L., P_9), 7 chemicals, boric acid (C_1),borax (C_2), oxalic acid (C_3), sodium oxalite (C_4), sodium dihydrogen phosphate (C_6), sodiumsilicate (C_7) and sodium citrate (C_8), and a natural organic substance, humic acid (C_5), onurease activity of a neutral purple soil and recovery of urea nitrogen by maize were studied throughincubation and pot experiments. Hydroquinone (HQ) was applied as the reference inhibitor. Afterincubation at 37℃ for 24 h, 7 inhibitors with higher ability to inhibit urease activity wereselected and then incubated for 14 days at 25℃. Results of the incubation experiments showed thatsoil urease activity was greatly inhibited by them, and the inhibition effect followed an order ofP_2>P_4>C_3>C_2>P_3>C_1>HQ>P_1. The 7 selected materials reduced the accumulative amounts of Nreleased from urea and the maximum urease activity by 11.7%～28.4% and 26.7%～39.7%, respectively,and postponed the N release peak by 2～4 days in the incubation period of 14 days under constanttemperature, as compared to the control (no inhibitor). In the pot experiment with the 7 materialsat two levels of addition, low (L) and high (H), the C_1 (H), C_3 (H), C_1 (L), P_4 (L) and C_2 (L)treatments could significantly increase the dry weights of the aboveground parts and the totalbiomass of the maize plants and the apparent recovery rate of urea-N was increased by 6.3%～32.4% ascompared to the control (no hibitor).展开更多
This study was conducted to reveal the effects of silicon(Si) application on nutrient utilization efficiency by rice and on soil nutrient availability and soil microorganisms in a hybrid rice double-cropping planting ...This study was conducted to reveal the effects of silicon(Si) application on nutrient utilization efficiency by rice and on soil nutrient availability and soil microorganisms in a hybrid rice double-cropping planting system. A series of field experiments were conducted during 2017 and 2018. The results showed that Si nutrient supply improved grain yield and the utilization rates of nitrogen(N) and phosphorus(P) to an appropriate level for both early and late plantings, reaching a maximum at 23.4 kg/ha Si. The same trends were found for the ratios of available N(AN) to total N(TN) and available P(AP) to total P(TP), the soil microbial biomass carbon(MBC), microbial biomass nitrogen(MBN), microbial biomass phosphorus(MBP), and the ratios of MBN to TN and MBP to TP, at different levels of Si. Statistical analysis further revealed that Si application enhanced rice growth and increased the utilization rate of fertilizer due to an ecological mechanism, i.e., Si supply significantly increased the total amount of soil microorganisms in paddy soil compared to the control. This promoted the mineralization of soil nutrients and improved the availability and reserves of easily mineralized organic nutrients.展开更多
Fertility policies consist of not only the legal definition of"procreation",but also the"maternity"protection system,the complete set of selfconsistent social relations and policy systems formed ar...Fertility policies consist of not only the legal definition of"procreation",but also the"maternity"protection system,the complete set of selfconsistent social relations and policy systems formed around"fertility".Gender,labor and intergenerational relations are the cornerstones of a fertility policy system.In this framework,we focus on women of childbearing age as the main actors of reproductive behaviors,to research how drastic social changes have altered women,the above-mentioned relations,and policy support and analyze the structural factors that restrict women’s reproductive intentions.The traditional male breadwinner model,which can no longer prevail and the relatively slow development of maternity protection policies and service systems leave women of childbearing age in a dilemma between working hours and birth timing.Therefore,maternity protection policies should focus on improved decommodification of maternity insurance and the construction of women and children’s social welfare systems including childcare social service systems.展开更多
Influenced by animal welfare requirements and expensive labor cost, producers tend to feed layers in non-cage system such as floor rearing. With the development of commercial lines of dwarf layers, the property of dwa...Influenced by animal welfare requirements and expensive labor cost, producers tend to feed layers in non-cage system such as floor rearing. With the development of commercial lines of dwarf layers, the property of dwarf layers＇ natural mating is drawing more and more attention. In this study, the authors hybridized Nongda Ill dwarf layers with White Leghorn chickens in floor-rearing system to research whether dwarf layers had defect in natural mating. Two steps of experiments were performed. The authors detected the fertilization rate of collected eggs, observed chickens＇ behavior in step I when a hen from other group was suddenly put into and recorded copulation number of every group in step II from 7：30 to 19：30. The results indicated that drawf cocks were as good as Leghorn cocks in natrual mating under floor-rearing system while drawf hens were better than Leghorn hens. Observation results showed no difference on reaction to intermixed hens between drawf layers and Leghorn layers. The best proportion of male to female for drawf layers was 1：8 in this experiment and dwarf cocks tended to mate dwarf hens rather than Leghorn hens.展开更多
Determination of crop growth parameters of maize helps assess the performance of the crop for food security. A study was conducted in two seasons covering 2012 and 2013 to establish optimal irrigation and nitrogen fer...Determination of crop growth parameters of maize helps assess the performance of the crop for food security. A study was conducted in two seasons covering 2012 and 2013 to establish optimal irrigation and nitrogen fertilizer rates for drought tolerant hybrid maize （Zea mays L.）, DK8031 variety, in sandy loam soils using furrow irrigation. Four additive irrigation levels （119.05 mm, 238.10 mm, 357.15 mm and 476.2 mm） were allocated the main plots while five nitrogen fertilizer rates （0 kg/ha, 60, 75 kg/ha, 90 kg/ha and 100 kg/ha） were allocated the sub-plots. Both irrigation and nitrogen fertilizer treatments significantly enhanced crop growth parameters under consideration. Stand count per treatment plot, plant height and number of leaves per ranged from 45-59 plants/plot, 215-238 cm and 14-16 leaves respectively. It was concluded that use of supplementary irrigation and phased nitrogen fertilizer rates for maize growing in areas such as Embu can greatly promote crop growth.展开更多
This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a signifi...This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a significant and systematic difference between the application rates of the two discs （about 20%）. This difference had to be corrected by the manufacturer that carried out the necessary changes to the electric actuators. The fertilizer spreader had good distribution homogeneity, considering different working velocities and different positions in the parcel. The pattern distribution curve for 18% super phosphate fertilizer led to an effective working width of 28 meters, with a coefficient of variation of 15%. The longitudinal test, under experimental working conditions led to a machine delay time of 6-7 seconds. The results show an actual fertilization application density between 74%-90% of that determined for each location. These results confirm that the spreader can be used to spread fertilizer differentially in the field.展开更多
Reliable molecular biomarkers to predict fertility remain scarce.The current study investigated the potential of testis-specific circBOULE RNAs as biomarkers for male infertility and sperm quality.Using reverse transc...Reliable molecular biomarkers to predict fertility remain scarce.The current study investigated the potential of testis-specific circBOULE RNAs as biomarkers for male infertility and sperm quality.Using reverse transcription-PCR and real-time reverse transcription-PCR assays,we identified seven circular RNAs from the human BOULE gene in human sperm.We observed that the expression level of circEx3-6 was significantly reduced in asthenozoospermia,while the expression levels of both circEx2-6 and circEx2-7 were decreased in terato-zoospermia,compared with the controls.Furthermore,we demonstrated that the expression level of circEx2-6 was negatively correlated with the sperm DNA fragmentation index,and the expression level of circEx2-7 was correlated with both fertilization and cleavage rates in those treated with the assisted reproductive technologies.Further functional analyses in a transgenic fly model supported the roles of circBOULE RNAs in sperm development and human male fertility.Collectively,our findings support that sperm circBOULE RNAs may serve as diagnostic biomarkers for assessing sperm motility and DNA quality.Therefore,clinical application and significance of sperm circBOULE RNAs in the assisted reproductive technologies warrant further investigation.展开更多
The clinical applications of acrosin activity are limited.We analyzed 61578 male partners in infertile couples who visited the outpatient department of the Reproductive and Genetic Hospital of CITIC-Xiangya(Changsha,C...The clinical applications of acrosin activity are limited.We analyzed 61578 male partners in infertile couples who visited the outpatient department of the Reproductive and Genetic Hospital of CITIC-Xiangya(Changsha,China)between August 2014 and December 2019 to determine the reference ranges and thresholds for acrosin activity in infertile Chinese men;to determine whether correlations exist between acrosin activity and age,sperm concentration,sperm morphology,or sperm motility;and to evaluate whether acrosin activity could serve as an effective prognostic indicator for choosing between in vitro fertilization(IvF)and intracytoplasmic sperm injection(icsl)in the clinic.The cut-off value for the normal reference range of acrosin activity for male partners in infertile couples was 24.78μlU per 106 sperm.There was no significant association between acrosin activity and age,sperm concentration,semen volume,total sperm count,progressive motility,or total motile spermatozoa.A weak positive correlation was found between acrosin activity and normal sperm morphology.There was a statistically significant difference in abnormal acrosome morphology between the group with high acrosin activity(>24.78μlU per 106 sperm)and the group with low acrosin activity(<24.78μlU per 106 sperm).The group with a low IVF fertilization rate had a high index of abnormal acrosomal morphology at 21.2%,while the group with a high IVF fertilization rate had a low index of 0.2%.At an acrosin activity of<24.78μlU per 10 sperm,in one cycle of the same patient,the fertilization rate,normal fertilization rate,and good-quality embryo rate for Icsl were significantly higher than those for IVF.Therefore,the most promising application of acrosin activity could be in the selection of IcsI over IVF for infertile male patients with complete fertilization failure or a low fertilization rate.展开更多
[Objective]The paper was to improve the quality and growth rate of native yellow cattle in Wenzhou.[Method]Three groups of cattle were subjected to artificial insemination using frozen semen from Wagyu bull.The groups...[Objective]The paper was to improve the quality and growth rate of native yellow cattle in Wenzhou.[Method]Three groups of cattle were subjected to artificial insemination using frozen semen from Wagyu bull.The groups consisted of 20 native yellow cattle,20 Angus catle,and 20 Luxi yellow cattle.The heifers were subsequently evaluated for body size and body weight,and underwent treatment with estrus synchronization,artificial insemination,and early pregnancy diagnosis.[Result]The mean body size and body weight of native yellow cattle were found to be significantly lower than those of Angus cattle and Luxi yellow cattle(P<0.05).The estrus synchronization rate and mating rate of native yellow cattle were both 100%,while the corresponding rates for Angus cattle and Luxi yellow cattle were 90%and 95%,respectively.The ultrasound examination conducted on the 32m day following the mating revealed a distinct image of gestation sac,which,when considered alongside the findings of the rectal examination,may be indicative of pregnancy.The conception rates were 75%,72%,and 74%for native yllow cattle,Angus cattle,and Luxi yellow cattle,respectively.[Conclusion]The reproductive performance of native beef cattle is relatively superior.展开更多
Excessive fertilizer application is common in the management of winter wheat (Triticum aestivum L.) in northwest China. However, this practice does not necessarily guarantee higher wheat yield and also causes a waste ...Excessive fertilizer application is common in the management of winter wheat (Triticum aestivum L.) in northwest China. However, this practice does not necessarily guarantee higher wheat yield and also causes a waste of resources and environmental pollution. The nitrogen (N), phosphorus (P), and potassium (K) fertilizer application rates need to be optimized to reduce the nitrate residue in the soil while maintaining a high wheat yield. Field experiments were conducted in three consecutive growth seasons (2018-2021) on winter wheat in Northern Xinjiang of China with four reduced fertilization (N-P_(2)O_(5)- K_(2)O) rates (FS1: 166-80-30 kg/hm^(2), FS2: 0-80-30 kg/hm^(2), FS3: 166-0-30 kg/hm^(2), FS4: 166-80-0 kg/hm^(2)) and the local fertilization rate (CK: 240-105-38). The soil nutrients, nutrient uptake content of organ, dry matter accumulation, yield, and fertilization use efficiency were investigated. The results showed increasing NH_(4)^(+)-N concentrations in the soil over the three growing seasons, while NO_(3)^(-)-N concentrations decreased in the later experimental years. High soil NH_(4)^(+)-N concentration and low soil NH_(4)^(+)-N residues were observed in FS3. When the control fertilization (CK) was applied, the grains had a higher proportion of N and P, while the N content in grains was relatively low at the high fertilization rate. When the fertilizer supply was insufficient (FS2, FS3, and FS4), the proportion of vegetative organs to the total biomass was relatively low. Lower fertilization rates resulted in higher N, P, and K use efficiencies in 2019-2020 and 2020-2021, in comparison to those at higher rates, while FS2 exhibited the highest fertilizer use efficiency. When fertilization (CK) was sufficient, the dry matter accumulation decreased by 3.33%- 17.08%, and the harvest index increased by 0.87%-47.40%. FS1 had the highest spike number, which significantly increased by 17.98%, 17.80%, and 9.64% compared with CK during 2018-2019, 2019-2020, and 2020-2021, respectively. In conclusion, a reduction in fertilizer application compared with CK could provide excellent production results. The optimal drip fertigation approach for winter wheat production in the arid regions of northwest China was determined to be the N-P_(2)O_(5)-K_(2)O application rate of 166-80-30 kg/hm^(2) when comprehensively considering the winter wheat yield, soil NH_(4)^(+)-N, and NH_(4)^(+)-N, N use efficiency, P use efficiency, and K use efficiency. This research can provide a scientific basis for the responses of winter wheat production to nutrient uptake of drip-irrigated winter wheat in arid and semi-arid regions.展开更多
文摘The aging and declining birthrate is a common challenge faced by many countries in the world today,especially those with relatively developed economies.As close neighbors in East Asia,Japan and China are particularly prominent in this issue.Japan is one of the countries with the highest degree of aging globally,and its process is characterized by“getting rich first and aging later”;while China is known for its“aging before getting rich”and its ultra-large elderly population,and is experiencing a similar demographic transition at a faster pace.This paper aims to systematically compare the current characteristics of aging and declining birthrate issues in China and Japan,and deeply analyze the similarities and differences in the underlying economic,social,and cultural reasons.The study finds that the two countries are similar in overall trends such as low fertility rates and inverted population structures,but there are significant differences in the timing of the problem’s outbreak,its severity,and specific causes.Japan’s predicament is rooted in its long-term economic stagnation,mature welfare social system,and profound individualization trend;while China’s challenges are closely related to unique family planning policies,rapid socioeconomic changes,and significant urban-rural regional differences,as well as the deep penetration of the declining birthrate phenomenon from urban to rural areas,and the accelerated disintegration of traditional fertility concepts.
文摘[Objective] The research aimed to provide theoretical basis for the cultivation and production of peach.[Method] The three-year-old seedling peach tree was used as the materials,and NH4NO3 was used as the experimental nitrogen fertilizer.Three nitrogen levels,0,3,6 g per pot respectively were set to study the effects of different nitrogen fertilizer on the contents of soluble sugar,starch and internal structure of the root of the peaches.[Result] The contents of soluble sugar of roots and leaves increased with the increase of nitrogen fertilizer level,and the level of 6 g per pot was the highest,which showed extreme differences between the level of 3 g per pot and the control.However,starch contents showed opposite results,which decreased as the level of nitrogen fertilizer increased.Compared with the 3 g per pot level of nitrogen fertilizer and the control,the internal structure of root applied with nitrogen fertilizer of 6 g per pot level had larger fibrovascularcylinder,advanced vascular bundle,small-spaced thin-walled cells,smooth and full cells with smooth cell wall.[Conclusion]Appropriate nitrogen levels can accelerate the accumulation of soluble sugar and the growth of root tissue structure.
基金Supported by Natural Science Foundation of the Inner Mongolia Autonomous Region(2020MS04001)Inner Mongolia Autonomous Region Science and Technology Program Project+1 种基金Hetao College Science and Technology Research Project(HYYB202303)Hetao College Science and Technology Innovation Team.
文摘A growing global demand exists to formulate plans to lessen the greenhouse gas emissions produced by agricultural activities.The purpose of this study was to uncovered the changes in soil CO_(2)fluxes under varying scenarios including nitrogen fertilization rates,irrigation rates,and air temperatures in the Hetao Irrigation District(HID)over the 38-year period.DAYCENT model was used to predict carbon dioxide(CO_(2))fluxes from cultivated soils in the HID,Inner Mongolia from^(2)023 to 2060(the year of achieving the"carbon neutrality"goal)in this study.Results showed that mean soil CO_(2)fluxes in the sunflower field[1035.13 g/(m^(2).yr)]were significantly lower than those in the maize field[1405.54 g/(m^(2).yr)].An increase in nitrogen fertilization rate led to a significant escalation in soil CO_(2)fluxes.Moreover,elevating irrigation rates for washing salts by irrigation(WSBI)diminished soil CO_(2)fluxes in the sunflower field while amplifying them in the maize field.A rise in air temperature resulted in an increase in soil CO_(2)fluxes from the maize field,with annual increases observed,but a reduction in soil CO_(2)fluxes from the sunflower field.The sunflower fields in the HID have a more substantial advantage than the corn fields in mitigating soil CO_(2)emissions.
文摘The longstanding debate persists:is the economy for the people,or are people for the economy?Technological advancements have increasingly reduced the need for physical human labor in economic activities.However,the demand for human resources is expected to persist at some level.Historically,the necessary human resources for national economies have been sustained through birth rates or immigration.This study explores whether maintaining a stable fertility rate of 2.1 in modern EU member states can be achieved in the long term while adhering to constitutional and human rights standards.
基金Project supported by the Science and Technology Department of Guangdong Province,China (No.2004B33301007)the Rockefeller Brothers Fund,America.
文摘Fertilizers are heavily applied in orchards of the hilly and mountainous topography of South China and may increase nutrient loadings to receiving waters.A simple runoff collecting system was used to measure the effects of different fertilization treatments on total N and P concentrations of surface runoff in a Chinese chestnut (Castanea mollissima Blume) orchard in Dongyuan County,Guangdong Province,China.In such orchards,fertilizer was typically applied in two short furrows or pits on either side of each tree.Treatments included three application depths (surface,10cm and 20 cm),and three application rates (low,median and high).Results showed that 90.5% of the runoff water samples had a total N concentration higher than 0.35 mgL^(-1) and 54.2% had a total P concentration higher than 0.1 mgL^(-1).Fertilizer application at all depths and at all but the lowest rate significantly increased total N and P concentrations in runoff water.Fertilization with chemical compound fertilizer at a soil depth of 20cm produced significantly lower (P<0.05) total N concentration in runoff than both surface and 10-cm depth fertilization,and significantly lower (P<0.05) total P concentration in runoff than surface fertilization.Total N and P concentrations in runoff significantly increased with the application rate of organic fertilizers.With the exception of total P concentrations,which were not significantly different between the control and fertilization at a rate of 119 kg P ha-1 in organic form,all the other fertilization treatments produced significantly higher total N and total P concentrations in runoff than the control.A fertilization depth≥20cm and an application rate≤72 kg N ha^(-1) or 119 kg P ha^(-1) for compound organic fertilizer was suggested to substantially reduce N and P runoff losses from hillslope orchards and to protect receiving waters in South China.
基金The Second Tibetan Plateau Scientific Expedition and Research Program,No.2019QZKK0603Strategic Priority Research Program of Chinese Academy of Sciences,No.XDA20040000,No.XDA20090000。
文摘This paper studied the fertilizer rate(FR), fertilizer use efficiency(FUE) and fertilizer overuse rate(FOR) of rice, corn and wheat in China from 1998 to 2018 and briefly analysed the reasons why farmers were willing to apply more fertilizers.(1) The FR of grain in China reached 373.7 kg/ha in 2018, an increase of 26.8% compared to that in 1998. In 2018, the FR for corn was the highest, at 411.2 kg/ha, compared to the values of 338.3 kg/ha for rice and 371.7 kg/ha for wheat.(2) In recent years, the FUE of grain in China has obviously improved, with values of 32.9% in 1998, 36.7% in 2008, and 39.3% in 2018. In 2018, the FUE for rice was the highest(41.2%), followed by that for corn(39.9%), and the FUE for wheat was the lowest(36.0%).(3) By 2018, fertilizer was overused in all zones of rice, corn and wheat. In 2018, the average FOR for wheat reached 69.0%, which was 35.9% higher than that for corn and 42.8% higher than that for rice.(4) The lower price of chemical fertilizers was the main reason leading to overapplication.(5) Establishing market mechanisms and adjusting regional planting structures can be effective in reducing the application of chemical fertilizers.
基金the National Natural Science Foundation of China(40801097)the Natural Science Foundation of Fujian Province,China(2012J01107)
文摘Ammonia oxidation, the first and rate-limiting step of nitrification, is carried out by both ammonia-oxidizing bacteria （AOB） and ammonia-oxidizing archaea （AOA）. However, the relative importance of AOB and AOA to nitrification in terrestrial ecosystems is not well understood. The aim of this study was to investigate the effect of the nitrogen input amount on abundance and community composition of AOB and AOA in red paddy soil. Soil samples of 10-20 cm （root layer soil） and 0-5 cm （surface soil） depths were taken from a red paddy. Rice in the paddy was fertilized with different rates of N as urea of N1 （75 kg N ha＂ yr-1）, N2 （150 kg N ha~ yrl）, N3 （225 kg N ha1 yrl） and CK （without fertilizers） in 2009, 2010 and 2011. Abundance and community composition of ammonia oxidizers was analyzed by real-time PCR and denaturing gradient gel electrophoresis （DGGE） based on amoA （the unit A of ammonia monooxygenase） gene. Archaeal amoA copies in N3 and N2 were significantly （P〈0.05） higher than those in CK and N1 in root layer soil or in surface soil under tillering and heading stages of rice, while the enhancement in bacterial amoA gene copies with increasing of N fertilizer rates only took on in root layer soil. N availability and soil NO3--N content increased but soil NH4＋-N content didn＇t change with increasing of N fertilizer rates. Otherwise, the copy numbers of archaeal amoA gene were higher （P〈0.05） than those of bacterial amoA gene in root lary soil or in surface soil. Redundancy discriminate analysis based on DGGE bands showed that there were no obvious differs in composition of AOA or AOB communities in the field among different N fertilizer rates. Results of this study suggested that the abundance of ammonia-oxidizers had active response to N fertilizer rates and the response of AOA was more obvious than that of AOB. Similarity in the community composition of AOA or AOB among different N fertilizer rates indicate that the community composition of ammonia-oxidizers was relatively stable in the paddy soil at least in short term for three years.
基金Project supported by the National Natural Science Foundation of China (No. 30230250) the Ministry of Agriculture, China (No. 2003-Z53).
文摘Field experiments were conducted with five rates （0, 75, 150, 225, and 450 kg P205 ha^-1） of seedbed P fertilizer application to investigate the yield of tomato in response to fertilizer P rate on calcareous soils with widely different levels of Olsen P （13-142 mg kg^-1） at 15 sites in some suburban counties of Beijing in 1999. Under the condition of no P fertilizer application, tomato yield generally increased with an increase in soil test P levels, and the agronomic level for soil testing P measured with Olsen method was 50 or 82 mg kg^-1 soil to achieve 85% or 95% of maximum tomato yield, respectively. With regard to marketable yield, in the fields where Olsen-P levels were 〈 50 mg kg^-1, noticeable responses to applied P were observed. On the basis of a linear plateau regression, the optimum seedbed P application rate in the P-insufflcient fields was 125 kg P205 ha^-1 or about 1.5-2 times the P removal from harvested tomato plants. In contrast, in fields with moderate （50 〈 Olsen P 〈 90 mg kg^-1） or high （Olsen P 〉 90 mg kg^-1） available P, there was no marked effect on tomato fruit yield. Field survey data indicated that in most fields with conventional P management, a P surplus typically occurred. Thus, once the soil test P level reached the optimum for crop yield, it was recommended that P fertilizer application be restricted or eliminated to minimize negative environmental effects.
基金supported by the National Natural Science Foundation of China(No.81801518 and No.82071646).
文摘The present study aimed to evaluate the clinical outcomes of magnetic-activated cell sorting(MACS)in sperm preparation for male subjects with a sperm DNA fragmentation index(DFI)≥30%.A total of 86 patients who had undergone their first long-term long protocol were selected.The protocol involved in vitro fertilization(IVF)and intracytoplasmic sperm injection(ICSI)cycles,and the patients were divided into the MACS or control groups.The MACS group included sperm samples analyzed with MACS that were combined with density gradient centrifugation(DGC)and the swim-up(SU)technique(n=39),and the control group included sperm samples prepared using standard techniques(DGC and SU;n=41).No differences were noted with regard to basic clinical characteristics,number of oocytes retrieved,normal fertilization rate,cleavage rate,or transplantable embryo rate between the two groups in IVF/ICSI.In addition,the clinical pregnancy and implantation rates of the first embryo transfer cycles indicated no significant differences between the two groups.However,there was a tendency to improve the live birth rate(LBR)of the first embryo transfer cycle(63.2%vs 53.9%)and the cumulative LBR(79.5%vs 70.7%)in the MACS group compared with the control group.Moreover,the number of transferred embryos(mean±standard deviation[s.d.]:1.7±0.7 vs 2.3±1.6)and the transfer number of each retrieved cycle(mean±s.d.:1.2±0.5 vs 1.6±0.8)were significantly lower in the MACS group than those in the control group.Thus,the selection of nonapoptotic spermatozoa by MACS for higher sperm DFI could improve assisted reproductive clinical outcomes.
基金supported by the National Basic Research Program of China(973 Program,2010CB951502)the Special Fund for Agro-Scientific Research in the Public Interest in China(201103001)
文摘Excessive use of N fertilizer in intensive agriculture can increase crop yield and at the same time cause high carbon（C） emissions.This study was conducted to determine optimized N fertilizer application for high grain yield and lower C emissions in summer corn（Zea mays L.）.A field experiment, including 0（N0）, 75（N75）, 150（N150）, 225（N225）, and 300（N300） kg N ha–1 treatments, was carried out during 2010–2012 in the North China Plain（NCP）.The results showed that grain yield, input energy, greenhouse gas（GHG） emissions, and carbon footprint（CF） were all increased with the increase of N rate, except net energy yield（NEY）.The treatment of N225 had the highest grain yield（10 364.7 kg ha–1） and NEY（6.8%）, but the CF（0.25） was lower than that of N300, which indicates that a rate of 225 kg N ha–1 can be optimal for summer corn in NCP.Comparing GHG emision compontents, N fertilizer（0–51.1%） was the highest and followed by electricity for irrigation（19.73–49.35%）.We conclude that optimazing N fertilizer application rate and reducing electricity for irrigation are the two key measures to increase crop yield, improve energy efficiency and decrease GHG emissions in corn production.
基金the Laboratory of Material Cycling in Pedosphere,the Chinese Academy of Sciences the Chongqing Science and Technology Commission,China.
文摘Effects of residues of 9 plants, lemon eucalyptus (Eucalyptus citriodoraHook., P_1), robust eucalyptus (E. robusta Smith, P_2), Nepal camphortree (Cinnamomum glanduliferum(Wall.) Nees, P_3), tea (Camellia sinensis (Linn.) O. Ktze. f., P_4), oleander (Nerium indicum Mill,P_5), rape (Brassica campestris L., P_g), Chinese tallow tree (Sapium sebiferum L., P_7), tung(Vernicia fordii (Hemsl.), P_8), and croton (Croton tiglium L., P_9), 7 chemicals, boric acid (C_1),borax (C_2), oxalic acid (C_3), sodium oxalite (C_4), sodium dihydrogen phosphate (C_6), sodiumsilicate (C_7) and sodium citrate (C_8), and a natural organic substance, humic acid (C_5), onurease activity of a neutral purple soil and recovery of urea nitrogen by maize were studied throughincubation and pot experiments. Hydroquinone (HQ) was applied as the reference inhibitor. Afterincubation at 37℃ for 24 h, 7 inhibitors with higher ability to inhibit urease activity wereselected and then incubated for 14 days at 25℃. Results of the incubation experiments showed thatsoil urease activity was greatly inhibited by them, and the inhibition effect followed an order ofP_2>P_4>C_3>C_2>P_3>C_1>HQ>P_1. The 7 selected materials reduced the accumulative amounts of Nreleased from urea and the maximum urease activity by 11.7%～28.4% and 26.7%～39.7%, respectively,and postponed the N release peak by 2～4 days in the incubation period of 14 days under constanttemperature, as compared to the control (no inhibitor). In the pot experiment with the 7 materialsat two levels of addition, low (L) and high (H), the C_1 (H), C_3 (H), C_1 (L), P_4 (L) and C_2 (L)treatments could significantly increase the dry weights of the aboveground parts and the totalbiomass of the maize plants and the apparent recovery rate of urea-N was increased by 6.3%～32.4% ascompared to the control (no hibitor).
基金Project supported by the National Key Research and Development Project of China(No.2016YFD0200800)the National Natural Science foundation of China(No.41571226)。
文摘This study was conducted to reveal the effects of silicon(Si) application on nutrient utilization efficiency by rice and on soil nutrient availability and soil microorganisms in a hybrid rice double-cropping planting system. A series of field experiments were conducted during 2017 and 2018. The results showed that Si nutrient supply improved grain yield and the utilization rates of nitrogen(N) and phosphorus(P) to an appropriate level for both early and late plantings, reaching a maximum at 23.4 kg/ha Si. The same trends were found for the ratios of available N(AN) to total N(TN) and available P(AP) to total P(TP), the soil microbial biomass carbon(MBC), microbial biomass nitrogen(MBN), microbial biomass phosphorus(MBP), and the ratios of MBN to TN and MBP to TP, at different levels of Si. Statistical analysis further revealed that Si application enhanced rice growth and increased the utilization rate of fertilizer due to an ecological mechanism, i.e., Si supply significantly increased the total amount of soil microorganisms in paddy soil compared to the control. This promoted the mineralization of soil nutrients and improved the availability and reserves of easily mineralized organic nutrients.
文摘Fertility policies consist of not only the legal definition of"procreation",but also the"maternity"protection system,the complete set of selfconsistent social relations and policy systems formed around"fertility".Gender,labor and intergenerational relations are the cornerstones of a fertility policy system.In this framework,we focus on women of childbearing age as the main actors of reproductive behaviors,to research how drastic social changes have altered women,the above-mentioned relations,and policy support and analyze the structural factors that restrict women’s reproductive intentions.The traditional male breadwinner model,which can no longer prevail and the relatively slow development of maternity protection policies and service systems leave women of childbearing age in a dilemma between working hours and birth timing.Therefore,maternity protection policies should focus on improved decommodification of maternity insurance and the construction of women and children’s social welfare systems including childcare social service systems.
文摘Influenced by animal welfare requirements and expensive labor cost, producers tend to feed layers in non-cage system such as floor rearing. With the development of commercial lines of dwarf layers, the property of dwarf layers＇ natural mating is drawing more and more attention. In this study, the authors hybridized Nongda Ill dwarf layers with White Leghorn chickens in floor-rearing system to research whether dwarf layers had defect in natural mating. Two steps of experiments were performed. The authors detected the fertilization rate of collected eggs, observed chickens＇ behavior in step I when a hen from other group was suddenly put into and recorded copulation number of every group in step II from 7：30 to 19：30. The results indicated that drawf cocks were as good as Leghorn cocks in natrual mating under floor-rearing system while drawf hens were better than Leghorn hens. Observation results showed no difference on reaction to intermixed hens between drawf layers and Leghorn layers. The best proportion of male to female for drawf layers was 1：8 in this experiment and dwarf cocks tended to mate dwarf hens rather than Leghorn hens.
文摘Determination of crop growth parameters of maize helps assess the performance of the crop for food security. A study was conducted in two seasons covering 2012 and 2013 to establish optimal irrigation and nitrogen fertilizer rates for drought tolerant hybrid maize （Zea mays L.）, DK8031 variety, in sandy loam soils using furrow irrigation. Four additive irrigation levels （119.05 mm, 238.10 mm, 357.15 mm and 476.2 mm） were allocated the main plots while five nitrogen fertilizer rates （0 kg/ha, 60, 75 kg/ha, 90 kg/ha and 100 kg/ha） were allocated the sub-plots. Both irrigation and nitrogen fertilizer treatments significantly enhanced crop growth parameters under consideration. Stand count per treatment plot, plant height and number of leaves per ranged from 45-59 plants/plot, 215-238 cm and 14-16 leaves respectively. It was concluded that use of supplementary irrigation and phased nitrogen fertilizer rates for maize growing in areas such as Embu can greatly promote crop growth.
文摘This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a significant and systematic difference between the application rates of the two discs （about 20%）. This difference had to be corrected by the manufacturer that carried out the necessary changes to the electric actuators. The fertilizer spreader had good distribution homogeneity, considering different working velocities and different positions in the parcel. The pattern distribution curve for 18% super phosphate fertilizer led to an effective working width of 28 meters, with a coefficient of variation of 15%. The longitudinal test, under experimental working conditions led to a machine delay time of 6-7 seconds. The results show an actual fertilization application density between 74%-90% of that determined for each location. These results confirm that the spreader can be used to spread fertilizer differentially in the field.
基金supported by the National Natural Science Foundation of China(Grant Nos.31970792 and 31771652).
文摘Reliable molecular biomarkers to predict fertility remain scarce.The current study investigated the potential of testis-specific circBOULE RNAs as biomarkers for male infertility and sperm quality.Using reverse transcription-PCR and real-time reverse transcription-PCR assays,we identified seven circular RNAs from the human BOULE gene in human sperm.We observed that the expression level of circEx3-6 was significantly reduced in asthenozoospermia,while the expression levels of both circEx2-6 and circEx2-7 were decreased in terato-zoospermia,compared with the controls.Furthermore,we demonstrated that the expression level of circEx2-6 was negatively correlated with the sperm DNA fragmentation index,and the expression level of circEx2-7 was correlated with both fertilization and cleavage rates in those treated with the assisted reproductive technologies.Further functional analyses in a transgenic fly model supported the roles of circBOULE RNAs in sperm development and human male fertility.Collectively,our findings support that sperm circBOULE RNAs may serve as diagnostic biomarkers for assessing sperm motility and DNA quality.Therefore,clinical application and significance of sperm circBOULE RNAs in the assisted reproductive technologies warrant further investigation.
基金This study was supported by the Hunan Province Municipal Natural Science Foundation(2022JJ30018)to WNLHunan Province Health Commission Science Foundation(B202301037899)to WNLResearch Grant of CITIC-Xiangya(YNXM-201904)to WNL.
文摘The clinical applications of acrosin activity are limited.We analyzed 61578 male partners in infertile couples who visited the outpatient department of the Reproductive and Genetic Hospital of CITIC-Xiangya(Changsha,China)between August 2014 and December 2019 to determine the reference ranges and thresholds for acrosin activity in infertile Chinese men;to determine whether correlations exist between acrosin activity and age,sperm concentration,sperm morphology,or sperm motility;and to evaluate whether acrosin activity could serve as an effective prognostic indicator for choosing between in vitro fertilization(IvF)and intracytoplasmic sperm injection(icsl)in the clinic.The cut-off value for the normal reference range of acrosin activity for male partners in infertile couples was 24.78μlU per 106 sperm.There was no significant association between acrosin activity and age,sperm concentration,semen volume,total sperm count,progressive motility,or total motile spermatozoa.A weak positive correlation was found between acrosin activity and normal sperm morphology.There was a statistically significant difference in abnormal acrosome morphology between the group with high acrosin activity(>24.78μlU per 106 sperm)and the group with low acrosin activity(<24.78μlU per 106 sperm).The group with a low IVF fertilization rate had a high index of abnormal acrosomal morphology at 21.2%,while the group with a high IVF fertilization rate had a low index of 0.2%.At an acrosin activity of<24.78μlU per 10 sperm,in one cycle of the same patient,the fertilization rate,normal fertilization rate,and good-quality embryo rate for Icsl were significantly higher than those for IVF.Therefore,the most promising application of acrosin activity could be in the selection of IcsI over IVF for infertile male patients with complete fertilization failure or a low fertilization rate.
基金Supported by Wenzhou Science and Technology Commissioner Special Project(X2023070)Science and Technology Program Project of Taishun County(2023TSXM0028)Heilongjiang Provincial Natural Science Foundation-Jointly Guided Project(LH2022C092).
文摘[Objective]The paper was to improve the quality and growth rate of native yellow cattle in Wenzhou.[Method]Three groups of cattle were subjected to artificial insemination using frozen semen from Wagyu bull.The groups consisted of 20 native yellow cattle,20 Angus catle,and 20 Luxi yellow cattle.The heifers were subsequently evaluated for body size and body weight,and underwent treatment with estrus synchronization,artificial insemination,and early pregnancy diagnosis.[Result]The mean body size and body weight of native yellow cattle were found to be significantly lower than those of Angus cattle and Luxi yellow cattle(P<0.05).The estrus synchronization rate and mating rate of native yellow cattle were both 100%,while the corresponding rates for Angus cattle and Luxi yellow cattle were 90%and 95%,respectively.The ultrasound examination conducted on the 32m day following the mating revealed a distinct image of gestation sac,which,when considered alongside the findings of the rectal examination,may be indicative of pregnancy.The conception rates were 75%,72%,and 74%for native yllow cattle,Angus cattle,and Luxi yellow cattle,respectively.[Conclusion]The reproductive performance of native beef cattle is relatively superior.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFD1900805 and Grant No.2018YFD020040608).
文摘Excessive fertilizer application is common in the management of winter wheat (Triticum aestivum L.) in northwest China. However, this practice does not necessarily guarantee higher wheat yield and also causes a waste of resources and environmental pollution. The nitrogen (N), phosphorus (P), and potassium (K) fertilizer application rates need to be optimized to reduce the nitrate residue in the soil while maintaining a high wheat yield. Field experiments were conducted in three consecutive growth seasons (2018-2021) on winter wheat in Northern Xinjiang of China with four reduced fertilization (N-P_(2)O_(5)- K_(2)O) rates (FS1: 166-80-30 kg/hm^(2), FS2: 0-80-30 kg/hm^(2), FS3: 166-0-30 kg/hm^(2), FS4: 166-80-0 kg/hm^(2)) and the local fertilization rate (CK: 240-105-38). The soil nutrients, nutrient uptake content of organ, dry matter accumulation, yield, and fertilization use efficiency were investigated. The results showed increasing NH_(4)^(+)-N concentrations in the soil over the three growing seasons, while NO_(3)^(-)-N concentrations decreased in the later experimental years. High soil NH_(4)^(+)-N concentration and low soil NH_(4)^(+)-N residues were observed in FS3. When the control fertilization (CK) was applied, the grains had a higher proportion of N and P, while the N content in grains was relatively low at the high fertilization rate. When the fertilizer supply was insufficient (FS2, FS3, and FS4), the proportion of vegetative organs to the total biomass was relatively low. Lower fertilization rates resulted in higher N, P, and K use efficiencies in 2019-2020 and 2020-2021, in comparison to those at higher rates, while FS2 exhibited the highest fertilizer use efficiency. When fertilization (CK) was sufficient, the dry matter accumulation decreased by 3.33%- 17.08%, and the harvest index increased by 0.87%-47.40%. FS1 had the highest spike number, which significantly increased by 17.98%, 17.80%, and 9.64% compared with CK during 2018-2019, 2019-2020, and 2020-2021, respectively. In conclusion, a reduction in fertilizer application compared with CK could provide excellent production results. The optimal drip fertigation approach for winter wheat production in the arid regions of northwest China was determined to be the N-P_(2)O_(5)-K_(2)O application rate of 166-80-30 kg/hm^(2) when comprehensively considering the winter wheat yield, soil NH_(4)^(+)-N, and NH_(4)^(+)-N, N use efficiency, P use efficiency, and K use efficiency. This research can provide a scientific basis for the responses of winter wheat production to nutrient uptake of drip-irrigated winter wheat in arid and semi-arid regions.
