In eukaryotic cells,organelles in the secretory,lysosomal,and endocytic pathways actively exchange biological materials with each other through intracellular membrane trafficking,which is the process of transporting t...In eukaryotic cells,organelles in the secretory,lysosomal,and endocytic pathways actively exchange biological materials with each other through intracellular membrane trafficking,which is the process of transporting the cargo of proteins,lipids,and other molecules to appropriate compartments via transport vesicles or intermediates.These processes are strictly regulated by various small GTPases such as the RAS-like in rat brain(RAB)protein family,which is the largest subfamily of the RAS superfamily.Dysfunction of membrane trafficking affects tissue homeostasis and leads to a wide range of diseases,including neurological disorders and neurodegenerative diseases.Therefore,it is important to understand the physiological and pathological roles of RAB proteins in brain function.RAB35,a member of the RAB family,is an evolutionarily conserved protein in metazoans.A wide range of studies using cultured mammalian cells and model organisms have revealed that RAB35 mediates various processes such as cytokinesis,endocytic recycling,actin bundling,and cell migration.RAB35 is also involved in neurite outgrowth and turnover of synaptic vesicles.We generated brain-specific Rab35 knockout mice to study the physiological roles of RAB35 in brain development and function.These mice exhibited defects in anxiety-related behaviors and spatial memory.Strikingly,RAB35 is required for the precise positioning of pyramidal neurons during hippocampal development,and thereby for normal hippocampal lamination.In contrast,layer formation in the cerebral cortex occurred superficially,even in the absence of RAB35,suggesting a predominant role for RAB35 in hippocampal development rather than in cerebral cortex development.Recent studies have suggested an association between RAB35 and neurodegenerative diseases,including Parkinson's disease and Alzheimer's disease.In this review,we provide an overview of the current understanding of subcellular functions of RAB35.We also provide insights into the physiological role of RAB35 in mammalian brain development and function,and discuss the involvement of RAB35 dysfunction in neurodegenerative diseases.展开更多
Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-li...Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-like organoids,to more accurately model early human brain development and disease.To enable more consistent and intuitive reproduction of early brain development,in this study,we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture.This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation,resulting in a new type of human brain organoid system.This cerebral organoid system replicated the temporospatial characteristics of early human brain development,including neuroepithelium derivation,neural progenitor cell production and maintenance,neuron differentiation and migration,and cortical layer patterning and formation,providing more consistent and reproducible organoids for developmental modeling and toxicology testing.As a proof of concept,we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins.Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns,including bursts of cortical cell death and premature differentiation.Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity,accompanied by compensatory cell proliferation at ectopic locations.The convenience,flexibility,and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental,neurological,and neurotoxicological studies.展开更多
The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures.However,the lack of systematic and contin...The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures.However,the lack of systematic and continuous comparison between in vivo retinal development and the organotypic retinal explant culture makes this model controversial in postnatal retinal development studies.Thus,we aimed to verify the feasibility of using this model for postnatal retinal development studies by comparing it with the in vivo retina.In this study,we showed that postnatal retinal explants undergo normal development,and exhibit a consistent structure and timeline with retinas in vivo.Initially,we used SOX2 and PAX6 immunostaining to identify retinal progenitor cells.We then examined cell proliferation and migration by immunostaining with Ki-67 and doublecortin,respectively.Ki-67-and doublecortin-positive cells decreased in both in vivo and explants during postnatal retinogenesis,and exhibited a high degree of similarity in abundance and distribution between groups.Additionally,we used Ceh-10 homeodomain-containing homolog,glutamate-ammonia ligase(glutamine synthetase),neuronal nuclei,and ionized calcium-binding adapter molecule 1 immunostaining to examine the emergence of bipolar cells,Müller glia,mature neurons,and microglia,respectively.The timing and spatial patterns of the emergence of these cell types were remarkably consistent between in vivo and explant retinas.Our study showed that the organotypic retinal explant culture model had a high degree of consistency with the progression of in vivo early postnatal retina development.The findings confirm the accuracy and credibility of this model and support its use for long-term,systematic,and continuous observation.展开更多
Tyrosine phosphorylation is crucial for controlling normal cell growth,survival,intercellular communication,gene transcription,immune responses,and other processes.protein tyrosine phosphatase(PTP)and protein tyrosine...Tyrosine phosphorylation is crucial for controlling normal cell growth,survival,intercellular communication,gene transcription,immune responses,and other processes.protein tyrosine phosphatase(PTP)and protein tyrosine kinases(PTK)can achieve this goal by regulating multiple signaling pathways.Oedaleus decorus asiaticus is an important pest that infests the Mongolian Plateau grassland.We aimed to evaluate the survival rate,growth rate,overall performance,and ovarian developmental morphology of the 4th instar nymphs of O.decorus asiaticus while inhibiting the activity of protein tyrosine phosphatase-1B(PTP1B)and PTK.In addition,the expression and protein phosphorylation levels of key genes in the MAPK signaling pathway and antioxidant enzyme activity were assessed.The results showed no significant differences in survival rate,growth rate,or overall performance between PTP1B inhibitor treatment and control.However,after PTK inhibitor treatment,these indexes were significantly lower than those in the control.The ovarian size of female larvae after 15 days of treatment with PTK inhibitors showed significantly slower development,while female larvae treated with PTP1B exhibited faster ovarian growth than the control group.In comparison to controls and nymphs treated with PTK inhibitors,the expression and phosphorylation levels of key genes in the MAPK signaling pathway under PTP1B inhibitor treatments were significantly higher in 4th instar nymphs.However,reactiveoxygen(ROS)species levels and the activities of NADPH oxidase and other antioxidant enzymes were considerably reduced,although they were significantly greater in the PTK inhibitor treatment.The results suggest that PTP1B and PTK feedback inhibition in the mitogen-activated-protein kinases(MAPK)signal transfer can regulate the physiological metabolism of the insect as well as its developmental rate.These findings can facilitate future uses of PTP1B and PTK inhibitors in controlling insect development to help control pest populations.展开更多
Objective:To investigate the effects of coenzyme Q10(CoQ10)supplementation on post-vitrification embryo development and gross morphology.Methods:Balb/c mouse embryos were cultured in potassium simplex optimised medium...Objective:To investigate the effects of coenzyme Q10(CoQ10)supplementation on post-vitrification embryo development and gross morphology.Methods:Balb/c mouse embryos were cultured in potassium simplex optimised medium(KSOM)with varying CoQ10 concentrations[0(control),20,40,and 60μM].The most effective CoQ10 concentration(40μM)was selected for subsequent post-vitrification morphology study.Embryos were randomly divided into four groups:Group A(non-vitrified without CoQ10),Group B(non-vitrified with CoQ10),Group C(vitrified without CoQ10),and Group D(vitrified with CoQ10),followed by vitrification at the 8-cell stage.Survival rates and development until the blastocyst stage were evaluated through morphological examinations using ASEBIR's system,distinguishing normal and abnormal embryos.Results:Supplementation of 40μM CoQ10 significantly increased blastocyst formation(95%)compared to the control group(92%),20μM(62%),and 60μM(56%)(P<0.001).Following vitrification,Group D exhibited a significant increase in blastocyst formation(92%)compared to Group C(82%)(P<0.05).Morphological assessments indicated superior embryo quality in Group B over Group D during the cleavage stage,morula,and blastocyst(P<0.05).Conclusions:CoQ10 supplementation exhibits promising potential to enhance preimplantation embryo development,increase blastocyst formation rates,and improve embryo quality post-vitrification.This offers a promising approach to mitigate oxidative stress on embryos,potentially improving overall assisted reproductive technology outcomes.展开更多
With the aim of reducing the cost of developing internal combustion engines,while at the same time investigating different geometries,layouts and fuels,3D-CFD-CHT simulations represent an indispensable part for the de...With the aim of reducing the cost of developing internal combustion engines,while at the same time investigating different geometries,layouts and fuels,3D-CFD-CHT simulations represent an indispensable part for the development of new technologies.These tools are increasingly used by manufacturers,as a screening process before building the first prototype.This paper presents an innovative methodology for virtual engine development.The 3D-CFD tool QuickSim,developed at FKFS,allows both a significant reduction in computation time and an extension of the simulated domain for complete engine systems.This is possible thanks to a combination of coarse meshes and self-developed internal combustion engine models,which simultaneously ensure high predictability.The present work demonstrates the capabilities of this innovative methodology for the design and optimization of different engines and fuels with the goal of achieving the highest possible combustion efficiencies and pollutant reductions.The analysis focuses on the influence of different fuels such as hydrogen,methanol,synthetic gasolines and methane on different engine geometries,in combination with suitable injection and ignition systems,including passive and active pre-chambers.Lean operations as well as knock reduction are discussed,particularly for methane and hydrogen injection.Finally,it is shown how depending on the chosen fuel,an appropriate ad-hoc engine layout can be designed to increase the indicated efficiency of the respective engines.展开更多
Castor is one of the top 10 oil crops in the world and has extremely valuable uses.Castor inflorescences directly affect yield,so the study of inflorescence development is very important in increasing castor yield.Our...Castor is one of the top 10 oil crops in the world and has extremely valuable uses.Castor inflorescences directly affect yield,so the study of inflorescence development is very important in increasing castor yield.Our previous studies have shown that the PIP5K gene family(PIP5Ks)is associated with inflorescence development.In this study,to determine the function of each PIP5K gene in castor,a female Lm-type castor line,aLmAB2,was used to determine the relative expression levels of the PIP5Ks in castor inflorescences.Six PIP5K genes were heterologously overexpressed in Arabidopsis thaliana,the relative expression of each gene and the effect on plants was determined in A.thaliana,and the relationships among the PIP5Ks in castor were inferred.The expression levels of the PIP5Ks in the female Lm-type castor line aLmAB2 were analyzed.The relative expression levels of the PIP5K9 and PIP5K11 genes were high(p<0.05)in isofemale inflorescences,and those of PIP5K1,PIP5K2,PIP5K6,and PIP5K8 were high(p<0.05)in female inflorescences but low(p<0.05)in bisexual inflorescences.The PIP5Ks were heterologously overexpressed in A.thaliana,and T3-generation plants with stable genetic resistance,i.e.,AT-PIP5K^(+)plants(AT-PIP5K1^(+),AT-PIP5K2^(+),AT-PIP5K6^(+),AT-PIP5K8^(+),AT-PIP5K9^(+),and ATPIP5K11^(+) plants),were obtained.Biological tests of the AT-PIP5K+plants showed that the growth of the main stem was significantly delayed in AT-PIP5K+plants compared with Columbia wild-type(WT)A.thaliana plants;the PIP5K1 and PIP5K2 genes promoted lateral stem growth and flower and silique development;and the PIP5K6,PIP5K8,PIP5K9 and PIP5K11 genes inhibited lateral stem growth and flower and silique development.The correlations among PIP5Ks in castor suggest that there may be a synergistic relationship among PIP5K1,PIP5K2,and PIP5K6 in castor inflorescences,and PIP5K8,PIP5K9,and PIP5K11 are complementary to the other three genes.展开更多
Utilizing provincial panel data from 2014 to 2020,this study employs a fixed effect model,a threshold effect model,and a spatial lag model to empirically examine the correlation between digital economic development an...Utilizing provincial panel data from 2014 to 2020,this study employs a fixed effect model,a threshold effect model,and a spatial lag model to empirically examine the correlation between digital economic development and carbon productivity.The findings indicate that digital economic development significantly contributes to the enhancement of carbon productivity in the long term.Furthermore,through instrumental variable method,replacement of explanatory variables and other methods to test its endogeneity and stability,the results remain robust.In terms of regional heterogeneity,the impact of digital economic development on carbon productivity is less pronounced in the central and western regions compared to the eastern region.Additionally,further investigation reveals that industrial structure upgrading and science and technology investment level exhibit different threshold effects on the influence of digital economy development level on carbon productivity.Moreover,there is a significant spatial spillover effect of digital economy development on carbon productivity with H-H and L-L agglomeration spatial correlation.展开更多
[Objectives]The paper was to explore the effects of different doses of water-retaining agent on the growth and development indicators,yield and quality of soybean plants subjected to drought stress.[Methods]The effect...[Objectives]The paper was to explore the effects of different doses of water-retaining agent on the growth and development indicators,yield and quality of soybean plants subjected to drought stress.[Methods]The effects of drought stress(MDS)and drought stress with low(MDS-L),medium(MDS-M)and high doses(MDS-H)of the water-retaining agent on the growth and development indicators,root activity,MDA content,antioxidant enzyme activity,yield and quality of soybean were studied by field plot test,with the normal water supply serving as the control(CK).[Results]In response to drought stress,the plant height,stem diameter,and yield of soybean exhibited a notable decline.Additionally,the contents of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a significant reduction.Conversely,the root activity and antioxidant enzyme activity exhibited a noticeable decline,while the MDA content exhibited an increase.The application of varying doses of the water-retaining agent was found to significantly enhance soybean growth,stimulate root activity,and elevate antioxidant enzyme activity,while concurrently reducing MDA content.The observed effects were found to be dose-dependent,with the greatest effects observed at the highest dose.In comparison to MDS,the yields of soybean in the MDS-L,MDS-M,and MDS-H treatments exhibited a 18.38%,25.58%,and 46.26%increase,respectively.Additionally,the content of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a notable enhancement.[Conclusions]The application of the water-retaining agent has been demonstrated to significantly promote the growth of soybean plants under conditions of drought stress,resulting in an improvement in both the yield and the quality of the soybean crop.The recommended dosage of the water-retaining agent is 3.3 kg/667 m 2.展开更多
Female grasshoppers can affect the fitness of their offspring through their selection of oviposition site. Knowledge of soil type on oviposition, and its effects on subsequent development can provide guidelines for ha...Female grasshoppers can affect the fitness of their offspring through their selection of oviposition site. Knowledge of soil type on oviposition, and its effects on subsequent development can provide guidelines for habitat manipulations that reduce the harmful effects of these pests on farmers fields. The influence of soil types on the oviposition site preference of variegated grasshopper (Zonocerus variegatus L.) reared some cassava (Manihot esculenta Crantz) varieties, was investigated in a cage trial carried out at the Bio factory laboratory, School of Agriculture and Food Sciences, Njala University, Sierra Leone during 2022/2023. The treatments comprised three soil types (Sandy, Loamy and Clay), each with three replications laid out in a randomized complete block design (RCBD) in wooden cages. Data were collected on the following development parameters including, Net reproductive growth ratio (R0), Generation time (Tc), Intrinsic rate of increase (rm), Finite rate of increase (), Doubling time (Dt), and overall survivorship. Findings revealed that, Z. variegatus L. preferred sandy soil in which, on average, most eggs were deposited (338, 6.62 4.40), followed by loamy soil, 286 (5.53 3.96), and then, clayey soil, 200 (3.91 3.85);though, the differences were not significant. This study established that Z. variegatus deposited more eggs in sandy soil > loamy soil > clayey soil, respectively;and subsequent survivorship of the immature unto mature adult insect, revealed a similar order. This indicates that the sandy soil is the most preferred substrate for oviposition and subsequent development into adult insects.展开更多
Seedling quality is a prerequisite for successful field performance and therefore influences crop yields. Temperature and illumination are two major factors affecting seedling quality during nursery propagation. Subop...Seedling quality is a prerequisite for successful field performance and therefore influences crop yields. Temperature and illumination are two major factors affecting seedling quality during nursery propagation. Suboptimal temperature or light of nurseries generally result in leggy or weak seedlings and great economic loss. However, production of healthy seedlings is challenging due to the lack of knowledge in systemic management of nursery environments. In this study, we have established simulation models to predict how temperature and illumination coordinately influence the growth of tomato and cabbage seedlings. Specifically, correlation between seedling quality characteristics(root-shoot ratio, G value(growth function: defined as ratio of whole plant dry weight to days of seedling), healthy indexes) and TEP(thermal effectiveness and photosynthetically active radiation) were explored to establish the models, which were validated with independent test data. Our results suggested that the curve of healthy index 1(HI1) and TEP fitted well with high coefficient of determination(R2) in both species, indicating that the model is highly reliable. The HI1 simulation models for tomato and cabbage are HI1=0.0009e0.0308TEP-0.0015 and HI1= 0.0003e0.0671TEP-0.0003, respectively, which can be used for predicting vigors of tomato and cabbage seedlings grown under different temperature and light conditions.展开更多
The market development and policy matching of existing building energy-saving retrofits determine the effectiveness of policies in promoting the operation of existing building energy-saving retrofit market.Based on th...The market development and policy matching of existing building energy-saving retrofits determine the effectiveness of policies in promoting the operation of existing building energy-saving retrofit market.Based on the perspective of market development to evaluate the effectiveness of existing building energy-saving transformation policy,it is necessary to clarify the basic connotation of the effectiveness of existing building energy-saving transformation policy,systematically analyze the evaluation content,construct a multi-level evaluation index system,and select scientific and effective quantitative evaluation methods to implement a strict evaluation process.展开更多
The increasing of development failure on highland urges the professionals to develop solution on mitigating the problems. This paper discusses on land development process and legislation on highland development in Mal...The increasing of development failure on highland urges the professionals to develop solution on mitigating the problems. This paper discusses on land development process and legislation on highland development in Malaysia and Hong Kong. This study is focus on land use planning, laws and regulations pertaining to land development process. Hence, this research is to review the current development process including mechanism and legislation pertaining land development on highland in Malaysia and Hong Kong. Hong Kong is chosen as an example based on the fact that for its successfulness in managing highland developments. The main aim of this research is to evaluate the effectiveness of land development legislations and development approaches for highland development. This research reveals the effects and consequences of implementation regulations and development process on highland that have been used at Malaysia and Hong Kong. In Malaysia, land development process on highland is still in questionable;why present property laws and regulations are fail to achieve highland development standards as compared to Hong Kong. There are weaknesses that need to be overcome such as on the implementation and the intensity of the provision in property laws and regulation that can ensure the achievement of required land development process.展开更多
The source structure of students in Xinjiang higher vocational colleges is complicated; most of the students have multi-variant ideologies and weak self-control ability. Under such background, the struggle of anti-ces...The source structure of students in Xinjiang higher vocational colleges is complicated; most of the students have multi-variant ideologies and weak self-control ability. Under such background, the struggle of anti-cession and anti-osmosis in the ideological field of Xinjiang higher vocational colleges will become more severe. As the domestic and foreign hostile forces conduct more and more osmosis means in the ideological field of Xinjiang higher vocational colleges and the situations become more and more complicated, the splittism of Xinjiang nations gradually escalates. They have not only made some violent and terrorist activities in the society, but also used the religion to split and permeate the students in higher vocational colleges and some teenagers. Higher vocational colleges are the main export to transmit talents to the nation and the society, so we have to pay enough attention to ideological cultivation and education of students.展开更多
[Objective] The paper was to explore the effect of different sowing dates and densities on individual morphological development of super short-season insect-resistant cotton,confirm their effects on vegetative and rep...[Objective] The paper was to explore the effect of different sowing dates and densities on individual morphological development of super short-season insect-resistant cotton,confirm their effects on vegetative and reproductive growth of cotton,so as to provide theoretical and practical guidance for sowing date and density management of cotton planting in Jidong cotton growing region in Yellow River Basin.[Method] With super short-season insect-resistant cotton"546"as materials,the effects of different sowing dates(sowing dateⅠ:May 20;sowing dateⅡ:June 2;sowing date Ⅲ:June 14)and densities(low density:120 000 plants/hm2;middle density:150 000 plants/hm2;high density:180 000 plants/hm2)on individual morphological development of super short-season insect-resistant cotton were explored.[Result] Different sowing dates and density treatments significantly affected the individual morphological development of super short-season insect-resistant cotton"546".The effectiveness of sowing date was higher than the effectiveness of density,and the effectiveness of sowing date on development of number of individual fruit branches was higher than that on plant height and stem diameter.[Conclusion] The regulation of sowing date and density during the cultivation process of super short-season insect-resistant cotton "546" in Jidong cotton growing region in Yellow River Basin could effectively promote vegetative and reproductive growth of cotton,strengthening its production base.展开更多
[Objective] This study aimed to explore an optimum application amount of nitrogen for cotton cultivation. [Method] In this study, a field experiment was conducted to investigate the effects of nitrogen application amo...[Objective] This study aimed to explore an optimum application amount of nitrogen for cotton cultivation. [Method] In this study, a field experiment was conducted to investigate the effects of nitrogen application amount on the growth characteristics, boll development and lint yield of high quality cotton line FZ-1. [Result] Compared with the nitrogen level of 225 kg/hm2, the lint yield had increased by 28.46% and 18.73%, respectively, with the nitrogen application amount of 300 and 375 kg/hm2. When the nitrogen application amount had increased from 225 to 300 kg/hm2, boll number per plant, boll weight and lint yield had significantly increased. At the nitrogen level of 375 kg/hm2, however, the effects of increasing lint yield were significantly less than that at the nitrogen level of 300 kg/hm2. Compared with the nitrogen levels of 225 and 375, 300 kg/hm2 of nitrogen was the optimum application amount to improve the plant height, daily increment of plant height, number of fruit branches, number ratio of nodes to fruit branches, boll volume and seed cotton weight per boll. [Conclusion] The rational management of nitrogen is the most effective way to promote the growth and development of cotton plants, ensure high yielding ability and minimize the environmental pollution caused by the overuse of nitrogen. This study had provided a sound nitrogen application strategy for the cultivation of this high-quality cotton line in the field plantation.展开更多
Effects of light intensity on growth, development and formation on Fagopy- rum cymosum were explored with natural light intensities at 100%(A), 85.2%(B), 75.8%(C) and 59.7%(D). The results showed that the decl...Effects of light intensity on growth, development and formation on Fagopy- rum cymosum were explored with natural light intensities at 100%(A), 85.2%(B), 75.8%(C) and 59.7%(D). The results showed that the decline of light intensity re- duced nutrient growth period, so that plant growth stage entered in advance and extended, which indicated that the decline of light intensity would lower leaf number and area, the number of twigs from the stem, as well as photosynthate. Further- more, the reduction degree increased upon light intensity decrease degree, and the proper shading improved stem height and leaf area enhanced before growth term.展开更多
The research analyzed social and economic development around Chao Lake as well as changes of water quality in Chao Lake and explored the relation- ships of local population and GDP with water chemical oxygen demand (...The research analyzed social and economic development around Chao Lake as well as changes of water quality in Chao Lake and explored the relation- ships of local population and GDP with water chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN), chlorophyll and eutrophication index. The re- sults showed that population around Chao Lake and GDP kept growing from 2001 to 2013, and water quality was improving. In addition, correlation analysis indicated that except of water eutrophication, GDP and population showed inverse correlation with other indices, demonstrating that water quality has been effectively controlled in Chao Lake recently.展开更多
This paper reports on a study investigating the impact of collaborative assessment on language development and learning. It involves two groups of sophomore students at Dalian Finance University. Two questions were ex...This paper reports on a study investigating the impact of collaborative assessment on language development and learning. It involves two groups of sophomore students at Dalian Finance University. Two questions were explored: 1) what benefits and difficulties exist in collaborative assessment? 2) what effects does collaborative assessment have on learning?The paper begins with an account of the procedures adopted for the study, followed by its finding and discussion of the findings which is a evidence which points to a shift of participants' role from passive learner to active participant as well as change in the use of learning strategies.展开更多
Polychlorinated biphenyls (PCBs) are widespread environmental contaminants that are possible health hazards for human beings through a variety of pathways.In the present study,50 time mated pregnant rats were divided ...Polychlorinated biphenyls (PCBs) are widespread environmental contaminants that are possible health hazards for human beings through a variety of pathways.In the present study,50 time mated pregnant rats were divided into five groups and injected daily from gestational days 7 to 18 with either 2,2′,4,4′- tetrachlorobiphenyl (PCB 47) or 3,3′,4,4′- tetrachlorobiphenyl (PCB 77) or seseme oil (control) to evaluate the effects of these PCBs on prenatal and postnatal development.Offspring were examined for malformations of genitalia at birth and in adulthood.Body weight gains of these animals were checked every 7 days through postnatal day (PND) 119.There were no clinical signs of toxicity in the PCB-treated dams or their offspring throughout the experiment.Litter size and sex ratio of the litters were not affected.Both PCBs produced a significant increase in the females' anogenital distance,suggesting a modification of androgen responsiveness in females resulting from PCB exposure during development.Similar effects were not seen with the males.The proportion of individuals with eyes open by PND 15 was significantly reduced by both PCBs.Exposure to 1 mg/kg body weight of PCB 77 significantly reduced body weight gains in male pups from PND 35 to 119.However,no significant differences were found in body weight gains of the pups exposed to PCB 47.展开更多
基金supported by the Japan Society for the Promotion of Science KAKENHI(grant Nos.23K05678 to IM,19H05711 and 20H00466 to KS)the Joint Research Program of Institute for Molecular and Cellular Regulation,Gunma University(to KS)。
文摘In eukaryotic cells,organelles in the secretory,lysosomal,and endocytic pathways actively exchange biological materials with each other through intracellular membrane trafficking,which is the process of transporting the cargo of proteins,lipids,and other molecules to appropriate compartments via transport vesicles or intermediates.These processes are strictly regulated by various small GTPases such as the RAS-like in rat brain(RAB)protein family,which is the largest subfamily of the RAS superfamily.Dysfunction of membrane trafficking affects tissue homeostasis and leads to a wide range of diseases,including neurological disorders and neurodegenerative diseases.Therefore,it is important to understand the physiological and pathological roles of RAB proteins in brain function.RAB35,a member of the RAB family,is an evolutionarily conserved protein in metazoans.A wide range of studies using cultured mammalian cells and model organisms have revealed that RAB35 mediates various processes such as cytokinesis,endocytic recycling,actin bundling,and cell migration.RAB35 is also involved in neurite outgrowth and turnover of synaptic vesicles.We generated brain-specific Rab35 knockout mice to study the physiological roles of RAB35 in brain development and function.These mice exhibited defects in anxiety-related behaviors and spatial memory.Strikingly,RAB35 is required for the precise positioning of pyramidal neurons during hippocampal development,and thereby for normal hippocampal lamination.In contrast,layer formation in the cerebral cortex occurred superficially,even in the absence of RAB35,suggesting a predominant role for RAB35 in hippocampal development rather than in cerebral cortex development.Recent studies have suggested an association between RAB35 and neurodegenerative diseases,including Parkinson's disease and Alzheimer's disease.In this review,we provide an overview of the current understanding of subcellular functions of RAB35.We also provide insights into the physiological role of RAB35 in mammalian brain development and function,and discuss the involvement of RAB35 dysfunction in neurodegenerative diseases.
基金supported by the National Key R&D Program of China,No.2019YFA0110300(to ZG)the National Natural Science Foundation of China,Nos.81773302(to YF),32070862(to ZG).
文摘Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-like organoids,to more accurately model early human brain development and disease.To enable more consistent and intuitive reproduction of early brain development,in this study,we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture.This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation,resulting in a new type of human brain organoid system.This cerebral organoid system replicated the temporospatial characteristics of early human brain development,including neuroepithelium derivation,neural progenitor cell production and maintenance,neuron differentiation and migration,and cortical layer patterning and formation,providing more consistent and reproducible organoids for developmental modeling and toxicology testing.As a proof of concept,we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins.Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns,including bursts of cortical cell death and premature differentiation.Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity,accompanied by compensatory cell proliferation at ectopic locations.The convenience,flexibility,and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental,neurological,and neurotoxicological studies.
基金supported by the National Natural Science Foundation of China,Nos.81901156(to ZZ),82271200(to ZZ),82171308(to XC)the Fundamental Research Funds for the Central Universities,No.xzy012022035(to ZZ)+1 种基金the Natural Science Foundation of Shaanxi Province,Nos.2021JM-261(to QK),2023-YBSF-303(to ZZ)Traditional Chinese Medicine Project of Shaanxi Province,No.2019-ZZ-JC047(to QK)。
文摘The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures.However,the lack of systematic and continuous comparison between in vivo retinal development and the organotypic retinal explant culture makes this model controversial in postnatal retinal development studies.Thus,we aimed to verify the feasibility of using this model for postnatal retinal development studies by comparing it with the in vivo retina.In this study,we showed that postnatal retinal explants undergo normal development,and exhibit a consistent structure and timeline with retinas in vivo.Initially,we used SOX2 and PAX6 immunostaining to identify retinal progenitor cells.We then examined cell proliferation and migration by immunostaining with Ki-67 and doublecortin,respectively.Ki-67-and doublecortin-positive cells decreased in both in vivo and explants during postnatal retinogenesis,and exhibited a high degree of similarity in abundance and distribution between groups.Additionally,we used Ceh-10 homeodomain-containing homolog,glutamate-ammonia ligase(glutamine synthetase),neuronal nuclei,and ionized calcium-binding adapter molecule 1 immunostaining to examine the emergence of bipolar cells,Müller glia,mature neurons,and microglia,respectively.The timing and spatial patterns of the emergence of these cell types were remarkably consistent between in vivo and explant retinas.Our study showed that the organotypic retinal explant culture model had a high degree of consistency with the progression of in vivo early postnatal retina development.The findings confirm the accuracy and credibility of this model and support its use for long-term,systematic,and continuous observation.
基金the National Key R&D Program of China(2022YFD1400500)the earmarked fund for China Agriculture Research System(CARS-34)the Central Public-interest Scientific Institution Basal Research Fund of China(S2022XM21)。
文摘Tyrosine phosphorylation is crucial for controlling normal cell growth,survival,intercellular communication,gene transcription,immune responses,and other processes.protein tyrosine phosphatase(PTP)and protein tyrosine kinases(PTK)can achieve this goal by regulating multiple signaling pathways.Oedaleus decorus asiaticus is an important pest that infests the Mongolian Plateau grassland.We aimed to evaluate the survival rate,growth rate,overall performance,and ovarian developmental morphology of the 4th instar nymphs of O.decorus asiaticus while inhibiting the activity of protein tyrosine phosphatase-1B(PTP1B)and PTK.In addition,the expression and protein phosphorylation levels of key genes in the MAPK signaling pathway and antioxidant enzyme activity were assessed.The results showed no significant differences in survival rate,growth rate,or overall performance between PTP1B inhibitor treatment and control.However,after PTK inhibitor treatment,these indexes were significantly lower than those in the control.The ovarian size of female larvae after 15 days of treatment with PTK inhibitors showed significantly slower development,while female larvae treated with PTP1B exhibited faster ovarian growth than the control group.In comparison to controls and nymphs treated with PTK inhibitors,the expression and phosphorylation levels of key genes in the MAPK signaling pathway under PTP1B inhibitor treatments were significantly higher in 4th instar nymphs.However,reactiveoxygen(ROS)species levels and the activities of NADPH oxidase and other antioxidant enzymes were considerably reduced,although they were significantly greater in the PTK inhibitor treatment.The results suggest that PTP1B and PTK feedback inhibition in the mitogen-activated-protein kinases(MAPK)signal transfer can regulate the physiological metabolism of the insect as well as its developmental rate.These findings can facilitate future uses of PTP1B and PTK inhibitors in controlling insect development to help control pest populations.
基金supported by the Fundamental Research Grant Scheme(FRGS)[FRGS/1/2020/SKK06/UNIKL/02/1],from the Ministry of Higher Education,Malaysia.
文摘Objective:To investigate the effects of coenzyme Q10(CoQ10)supplementation on post-vitrification embryo development and gross morphology.Methods:Balb/c mouse embryos were cultured in potassium simplex optimised medium(KSOM)with varying CoQ10 concentrations[0(control),20,40,and 60μM].The most effective CoQ10 concentration(40μM)was selected for subsequent post-vitrification morphology study.Embryos were randomly divided into four groups:Group A(non-vitrified without CoQ10),Group B(non-vitrified with CoQ10),Group C(vitrified without CoQ10),and Group D(vitrified with CoQ10),followed by vitrification at the 8-cell stage.Survival rates and development until the blastocyst stage were evaluated through morphological examinations using ASEBIR's system,distinguishing normal and abnormal embryos.Results:Supplementation of 40μM CoQ10 significantly increased blastocyst formation(95%)compared to the control group(92%),20μM(62%),and 60μM(56%)(P<0.001).Following vitrification,Group D exhibited a significant increase in blastocyst formation(92%)compared to Group C(82%)(P<0.05).Morphological assessments indicated superior embryo quality in Group B over Group D during the cleavage stage,morula,and blastocyst(P<0.05).Conclusions:CoQ10 supplementation exhibits promising potential to enhance preimplantation embryo development,increase blastocyst formation rates,and improve embryo quality post-vitrification.This offers a promising approach to mitigate oxidative stress on embryos,potentially improving overall assisted reproductive technology outcomes.
文摘With the aim of reducing the cost of developing internal combustion engines,while at the same time investigating different geometries,layouts and fuels,3D-CFD-CHT simulations represent an indispensable part for the development of new technologies.These tools are increasingly used by manufacturers,as a screening process before building the first prototype.This paper presents an innovative methodology for virtual engine development.The 3D-CFD tool QuickSim,developed at FKFS,allows both a significant reduction in computation time and an extension of the simulated domain for complete engine systems.This is possible thanks to a combination of coarse meshes and self-developed internal combustion engine models,which simultaneously ensure high predictability.The present work demonstrates the capabilities of this innovative methodology for the design and optimization of different engines and fuels with the goal of achieving the highest possible combustion efficiencies and pollutant reductions.The analysis focuses on the influence of different fuels such as hydrogen,methanol,synthetic gasolines and methane on different engine geometries,in combination with suitable injection and ignition systems,including passive and active pre-chambers.Lean operations as well as knock reduction are discussed,particularly for methane and hydrogen injection.Finally,it is shown how depending on the chosen fuel,an appropriate ad-hoc engine layout can be designed to increase the indicated efficiency of the respective engines.
基金National Natural Science Foundation of China(31860071)Ministry of Education New Agricultural Research and Reform Practice Program(2020114)+4 种基金Surface Program of Inner Mongolia Natural Science Foundation(2021MS03008)Inner Mongolia Autonomous Region Grassland Talent Innovation Team-Rolling Support Program for Castor Molecular Breeding Research Innovation Talent Teams(2022)2023 Inner Mongolia Autonomous Region Science and Technology Department Establishes the Project of Key Laboratory Construction of Castor Breeding and Comprehensive Utilization in Inner Mongolia Autonomous RegionInner Mongolia University for Nationalities 2022 Basic Research Operating Expenses of Colleges and Universities directly under the Autonomous Region Project(237)Open Fund Project of Castor Industry Collaborative Innovation Center of Inner Mongolia Autonomous Region(MDK2021011,MDK2022014).
文摘Castor is one of the top 10 oil crops in the world and has extremely valuable uses.Castor inflorescences directly affect yield,so the study of inflorescence development is very important in increasing castor yield.Our previous studies have shown that the PIP5K gene family(PIP5Ks)is associated with inflorescence development.In this study,to determine the function of each PIP5K gene in castor,a female Lm-type castor line,aLmAB2,was used to determine the relative expression levels of the PIP5Ks in castor inflorescences.Six PIP5K genes were heterologously overexpressed in Arabidopsis thaliana,the relative expression of each gene and the effect on plants was determined in A.thaliana,and the relationships among the PIP5Ks in castor were inferred.The expression levels of the PIP5Ks in the female Lm-type castor line aLmAB2 were analyzed.The relative expression levels of the PIP5K9 and PIP5K11 genes were high(p<0.05)in isofemale inflorescences,and those of PIP5K1,PIP5K2,PIP5K6,and PIP5K8 were high(p<0.05)in female inflorescences but low(p<0.05)in bisexual inflorescences.The PIP5Ks were heterologously overexpressed in A.thaliana,and T3-generation plants with stable genetic resistance,i.e.,AT-PIP5K^(+)plants(AT-PIP5K1^(+),AT-PIP5K2^(+),AT-PIP5K6^(+),AT-PIP5K8^(+),AT-PIP5K9^(+),and ATPIP5K11^(+) plants),were obtained.Biological tests of the AT-PIP5K+plants showed that the growth of the main stem was significantly delayed in AT-PIP5K+plants compared with Columbia wild-type(WT)A.thaliana plants;the PIP5K1 and PIP5K2 genes promoted lateral stem growth and flower and silique development;and the PIP5K6,PIP5K8,PIP5K9 and PIP5K11 genes inhibited lateral stem growth and flower and silique development.The correlations among PIP5Ks in castor suggest that there may be a synergistic relationship among PIP5K1,PIP5K2,and PIP5K6 in castor inflorescences,and PIP5K8,PIP5K9,and PIP5K11 are complementary to the other three genes.
文摘Utilizing provincial panel data from 2014 to 2020,this study employs a fixed effect model,a threshold effect model,and a spatial lag model to empirically examine the correlation between digital economic development and carbon productivity.The findings indicate that digital economic development significantly contributes to the enhancement of carbon productivity in the long term.Furthermore,through instrumental variable method,replacement of explanatory variables and other methods to test its endogeneity and stability,the results remain robust.In terms of regional heterogeneity,the impact of digital economic development on carbon productivity is less pronounced in the central and western regions compared to the eastern region.Additionally,further investigation reveals that industrial structure upgrading and science and technology investment level exhibit different threshold effects on the influence of digital economy development level on carbon productivity.Moreover,there is a significant spatial spillover effect of digital economy development on carbon productivity with H-H and L-L agglomeration spatial correlation.
基金Supported by Science and Technology Program of the Fourth Division Kekedala City(2023GG11).
文摘[Objectives]The paper was to explore the effects of different doses of water-retaining agent on the growth and development indicators,yield and quality of soybean plants subjected to drought stress.[Methods]The effects of drought stress(MDS)and drought stress with low(MDS-L),medium(MDS-M)and high doses(MDS-H)of the water-retaining agent on the growth and development indicators,root activity,MDA content,antioxidant enzyme activity,yield and quality of soybean were studied by field plot test,with the normal water supply serving as the control(CK).[Results]In response to drought stress,the plant height,stem diameter,and yield of soybean exhibited a notable decline.Additionally,the contents of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a significant reduction.Conversely,the root activity and antioxidant enzyme activity exhibited a noticeable decline,while the MDA content exhibited an increase.The application of varying doses of the water-retaining agent was found to significantly enhance soybean growth,stimulate root activity,and elevate antioxidant enzyme activity,while concurrently reducing MDA content.The observed effects were found to be dose-dependent,with the greatest effects observed at the highest dose.In comparison to MDS,the yields of soybean in the MDS-L,MDS-M,and MDS-H treatments exhibited a 18.38%,25.58%,and 46.26%increase,respectively.Additionally,the content of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a notable enhancement.[Conclusions]The application of the water-retaining agent has been demonstrated to significantly promote the growth of soybean plants under conditions of drought stress,resulting in an improvement in both the yield and the quality of the soybean crop.The recommended dosage of the water-retaining agent is 3.3 kg/667 m 2.
文摘Female grasshoppers can affect the fitness of their offspring through their selection of oviposition site. Knowledge of soil type on oviposition, and its effects on subsequent development can provide guidelines for habitat manipulations that reduce the harmful effects of these pests on farmers fields. The influence of soil types on the oviposition site preference of variegated grasshopper (Zonocerus variegatus L.) reared some cassava (Manihot esculenta Crantz) varieties, was investigated in a cage trial carried out at the Bio factory laboratory, School of Agriculture and Food Sciences, Njala University, Sierra Leone during 2022/2023. The treatments comprised three soil types (Sandy, Loamy and Clay), each with three replications laid out in a randomized complete block design (RCBD) in wooden cages. Data were collected on the following development parameters including, Net reproductive growth ratio (R0), Generation time (Tc), Intrinsic rate of increase (rm), Finite rate of increase (), Doubling time (Dt), and overall survivorship. Findings revealed that, Z. variegatus L. preferred sandy soil in which, on average, most eggs were deposited (338, 6.62 4.40), followed by loamy soil, 286 (5.53 3.96), and then, clayey soil, 200 (3.91 3.85);though, the differences were not significant. This study established that Z. variegatus deposited more eggs in sandy soil > loamy soil > clayey soil, respectively;and subsequent survivorship of the immature unto mature adult insect, revealed a similar order. This indicates that the sandy soil is the most preferred substrate for oviposition and subsequent development into adult insects.
基金supported by the National Key Research and Development Program of China (2018YFD0201203)the Independent Innovation of Agricultural Science and Technology in Jiangsu Province, China (CX (15)1015)the Priority Academic Program Development of Jiangsu Higher Education Institutions, China
文摘Seedling quality is a prerequisite for successful field performance and therefore influences crop yields. Temperature and illumination are two major factors affecting seedling quality during nursery propagation. Suboptimal temperature or light of nurseries generally result in leggy or weak seedlings and great economic loss. However, production of healthy seedlings is challenging due to the lack of knowledge in systemic management of nursery environments. In this study, we have established simulation models to predict how temperature and illumination coordinately influence the growth of tomato and cabbage seedlings. Specifically, correlation between seedling quality characteristics(root-shoot ratio, G value(growth function: defined as ratio of whole plant dry weight to days of seedling), healthy indexes) and TEP(thermal effectiveness and photosynthetically active radiation) were explored to establish the models, which were validated with independent test data. Our results suggested that the curve of healthy index 1(HI1) and TEP fitted well with high coefficient of determination(R2) in both species, indicating that the model is highly reliable. The HI1 simulation models for tomato and cabbage are HI1=0.0009e0.0308TEP-0.0015 and HI1= 0.0003e0.0671TEP-0.0003, respectively, which can be used for predicting vigors of tomato and cabbage seedlings grown under different temperature and light conditions.
基金supported by the National Natural Fund of China(Grant No.71872122)Later Stage Support Project of Philosophy and Social Sciences Research of the Ministry of Education of China(Grant No.16JHQ031)+1 种基金Later Stage Support Project of Tianjin Social Science Planning(Grant No.TJGLHQ1403)Higher Education Innovation Team of Tianjin(Grant No.TD13-5006)。
文摘The market development and policy matching of existing building energy-saving retrofits determine the effectiveness of policies in promoting the operation of existing building energy-saving retrofit market.Based on the perspective of market development to evaluate the effectiveness of existing building energy-saving transformation policy,it is necessary to clarify the basic connotation of the effectiveness of existing building energy-saving transformation policy,systematically analyze the evaluation content,construct a multi-level evaluation index system,and select scientific and effective quantitative evaluation methods to implement a strict evaluation process.
文摘The increasing of development failure on highland urges the professionals to develop solution on mitigating the problems. This paper discusses on land development process and legislation on highland development in Malaysia and Hong Kong. This study is focus on land use planning, laws and regulations pertaining to land development process. Hence, this research is to review the current development process including mechanism and legislation pertaining land development on highland in Malaysia and Hong Kong. Hong Kong is chosen as an example based on the fact that for its successfulness in managing highland developments. The main aim of this research is to evaluate the effectiveness of land development legislations and development approaches for highland development. This research reveals the effects and consequences of implementation regulations and development process on highland that have been used at Malaysia and Hong Kong. In Malaysia, land development process on highland is still in questionable;why present property laws and regulations are fail to achieve highland development standards as compared to Hong Kong. There are weaknesses that need to be overcome such as on the implementation and the intensity of the provision in property laws and regulation that can ensure the achievement of required land development process.
文摘The source structure of students in Xinjiang higher vocational colleges is complicated; most of the students have multi-variant ideologies and weak self-control ability. Under such background, the struggle of anti-cession and anti-osmosis in the ideological field of Xinjiang higher vocational colleges will become more severe. As the domestic and foreign hostile forces conduct more and more osmosis means in the ideological field of Xinjiang higher vocational colleges and the situations become more and more complicated, the splittism of Xinjiang nations gradually escalates. They have not only made some violent and terrorist activities in the society, but also used the religion to split and permeate the students in higher vocational colleges and some teenagers. Higher vocational colleges are the main export to transmit talents to the nation and the society, so we have to pay enough attention to ideological cultivation and education of students.
基金Supported by Natural Science Foundation of Heibei Province(C2007000444)Hebei Science and Technology Support Program(10220208)~~
文摘[Objective] The paper was to explore the effect of different sowing dates and densities on individual morphological development of super short-season insect-resistant cotton,confirm their effects on vegetative and reproductive growth of cotton,so as to provide theoretical and practical guidance for sowing date and density management of cotton planting in Jidong cotton growing region in Yellow River Basin.[Method] With super short-season insect-resistant cotton"546"as materials,the effects of different sowing dates(sowing dateⅠ:May 20;sowing dateⅡ:June 2;sowing date Ⅲ:June 14)and densities(low density:120 000 plants/hm2;middle density:150 000 plants/hm2;high density:180 000 plants/hm2)on individual morphological development of super short-season insect-resistant cotton were explored.[Result] Different sowing dates and density treatments significantly affected the individual morphological development of super short-season insect-resistant cotton"546".The effectiveness of sowing date was higher than the effectiveness of density,and the effectiveness of sowing date on development of number of individual fruit branches was higher than that on plant height and stem diameter.[Conclusion] The regulation of sowing date and density during the cultivation process of super short-season insect-resistant cotton "546" in Jidong cotton growing region in Yellow River Basin could effectively promote vegetative and reproductive growth of cotton,strengthening its production base.
基金Supported by Natural Science Foundation of China(NSFC No.30771272,31171483)the Priority Academic Development Program of Jiangsu Higher Education Institutions+1 种基金Jiangsu Innovation Project for Agriculture Science and Technology(cx(11)2054)Jiangsu Agriculture Science and Technology Support Program(SBE2010307)~~
文摘[Objective] This study aimed to explore an optimum application amount of nitrogen for cotton cultivation. [Method] In this study, a field experiment was conducted to investigate the effects of nitrogen application amount on the growth characteristics, boll development and lint yield of high quality cotton line FZ-1. [Result] Compared with the nitrogen level of 225 kg/hm2, the lint yield had increased by 28.46% and 18.73%, respectively, with the nitrogen application amount of 300 and 375 kg/hm2. When the nitrogen application amount had increased from 225 to 300 kg/hm2, boll number per plant, boll weight and lint yield had significantly increased. At the nitrogen level of 375 kg/hm2, however, the effects of increasing lint yield were significantly less than that at the nitrogen level of 300 kg/hm2. Compared with the nitrogen levels of 225 and 375, 300 kg/hm2 of nitrogen was the optimum application amount to improve the plant height, daily increment of plant height, number of fruit branches, number ratio of nodes to fruit branches, boll volume and seed cotton weight per boll. [Conclusion] The rational management of nitrogen is the most effective way to promote the growth and development of cotton plants, ensure high yielding ability and minimize the environmental pollution caused by the overuse of nitrogen. This study had provided a sound nitrogen application strategy for the cultivation of this high-quality cotton line in the field plantation.
基金Special Funds for Fundamental Work of Ministry of Science and Technology(2006BAD13B02-13)~~
文摘Effects of light intensity on growth, development and formation on Fagopy- rum cymosum were explored with natural light intensities at 100%(A), 85.2%(B), 75.8%(C) and 59.7%(D). The results showed that the decline of light intensity re- duced nutrient growth period, so that plant growth stage entered in advance and extended, which indicated that the decline of light intensity would lower leaf number and area, the number of twigs from the stem, as well as photosynthate. Further- more, the reduction degree increased upon light intensity decrease degree, and the proper shading improved stem height and leaf area enhanced before growth term.
基金Supported by Anhui Environmental Protection Scientific Research Program(2014-004)~~
文摘The research analyzed social and economic development around Chao Lake as well as changes of water quality in Chao Lake and explored the relation- ships of local population and GDP with water chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN), chlorophyll and eutrophication index. The re- sults showed that population around Chao Lake and GDP kept growing from 2001 to 2013, and water quality was improving. In addition, correlation analysis indicated that except of water eutrophication, GDP and population showed inverse correlation with other indices, demonstrating that water quality has been effectively controlled in Chao Lake recently.
文摘This paper reports on a study investigating the impact of collaborative assessment on language development and learning. It involves two groups of sophomore students at Dalian Finance University. Two questions were explored: 1) what benefits and difficulties exist in collaborative assessment? 2) what effects does collaborative assessment have on learning?The paper begins with an account of the procedures adopted for the study, followed by its finding and discussion of the findings which is a evidence which points to a shift of participants' role from passive learner to active participant as well as change in the use of learning strategies.
文摘Polychlorinated biphenyls (PCBs) are widespread environmental contaminants that are possible health hazards for human beings through a variety of pathways.In the present study,50 time mated pregnant rats were divided into five groups and injected daily from gestational days 7 to 18 with either 2,2′,4,4′- tetrachlorobiphenyl (PCB 47) or 3,3′,4,4′- tetrachlorobiphenyl (PCB 77) or seseme oil (control) to evaluate the effects of these PCBs on prenatal and postnatal development.Offspring were examined for malformations of genitalia at birth and in adulthood.Body weight gains of these animals were checked every 7 days through postnatal day (PND) 119.There were no clinical signs of toxicity in the PCB-treated dams or their offspring throughout the experiment.Litter size and sex ratio of the litters were not affected.Both PCBs produced a significant increase in the females' anogenital distance,suggesting a modification of androgen responsiveness in females resulting from PCB exposure during development.Similar effects were not seen with the males.The proportion of individuals with eyes open by PND 15 was significantly reduced by both PCBs.Exposure to 1 mg/kg body weight of PCB 77 significantly reduced body weight gains in male pups from PND 35 to 119.However,no significant differences were found in body weight gains of the pups exposed to PCB 47.