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1.
In 1982,Alice Walker’s The Color Purple,was published and became one of the best sellers.As the novel progressed,Celie's acquiescent behavior transformed into one of resilience and dignity.By incorporating the literary techniques of tone,symbolism,and juxtaposition into her novel,Alice Walker was able to develop Celie's character,emphasizing her progression from subservience to independence.  相似文献   

2.
The Jilting of Granny Weatherall is one of Katherine Anne Porter’s most famous and successful short stories which shows her use of the stream-of-consciousness techniques substantially.This thesis tries to focus on the use of interior monologue and narrated monologue in this story especially.  相似文献   

3.
Algeria like many of its Middle Eastern and North African(MENA) counterparts,rely heavily on the industry of fossil fuels,such as gas and petroleum.This big reliance of Algerian economy on hydrocarbon exports revenue makes it very vulnerable to external shocks.So since the late 1990s different measures had been adopted to help promote the diversification of exports,but so far the adoption of these measures,has mixed results and has failed to boost foreign trade out of Hydrocarbons exports in a significant way.But unlike Algeria,China has been the most successful developing country in this modern era of globalization.It was one of the poorest countries in the world in 1980s,and since initiating economic reform after 1978 its GDP has expanded at a steady rate over 10% and it`s foreign trade is considered as one of the most important in the world.Given these facts the purpose of this paper is to analyze,why Algeria struggles to develop and diversify its exports out of Hydrocarbons.And what are the engines of the impressive growth of china’s foreign trade,if any;lessons can Algeria take from china’s foreign trade experience.  相似文献   

4.
5.
There is a dialogue between the developing conceptus (embryo-fetus and associated placental membranes) and maternal uterus which must be established during the peri-implantation period for pregnancy recognition signaling, implantation, regulation of gene expression by uterine epithelial and stromal cells, placentation and exchange of nutrients and gases. The uterus provide a microenvironment in which molecules secreted by uterine epithelia or transported into the uterine lumen represent histotroph required for growth and development of the conceptus and receptivity of the uterus to implantation. Pregnancy recognition signaling mechanisms sustain the functional lifespan of the corpora lutea (CL) which produce progesterone, the hormone of pregnancy essential for uterine functions that support implantation and placentation required for a successful outcome of pregnancy. It is within the peri-implantation period that most embryonic deaths occur due to deficiencies attributed to uterine functions or failure of the conceptus to develop appropriately, signal pregnancy recognition and/or undergo implantation and placentation. With proper placentation, the fetal fluids and fetal membranes each have unique functions to ensure hematotrophic and histotrophic nutrition in support of growth and development of the fetus. The endocrine status of the pregnant female and her nutritional status are critical for successful establishment and maintenance of pregnancy. This review addresses the complexity of key mechanisms that are characteristic of successful reproduction in sheep and pigs and gaps in knowledge that must be the subject of research in order to enhance fertility and reproductive health of livestock species.  相似文献   

6.
《饲料工业》2010,(3):29-30,32,33
The majority of micronutrients and pharmacologically active substances are extremely sensitive to the surrounding environment. Microcapsulation is utilized in many countries to increase the production stability and prevent mutual interference of all kinds of component. Therefore, microcapsule technology is a research focus and widely used in many fields, such as cosmetics, food industry, producers of photographic materials, computers, pesticides, fertilizer and feed industry.  相似文献   

7.
Background: Salmonella enterica serovar Enteritidis (SE), as a major cause of foodborn illness, infects humans mainly through the egg. However, the symptom of laying hens usually is not typical and hard to diagnosis. In the present study, it is studied that the influences of SE infection on layers' performance, egg quality and blood biochemical indicators. It will help us to improve the strategy to control SE infection in commercial layers. One hundred layers at 20 wk of age were divided into 2 groups, 60 hens for experiment and others for control. The experiment group was fed with the dosage of 108 CFU SE per hen. The specific PCR was used to detect the deposition of SE. On the 8 d after SE infection, 10 hens from the control group and 30 hens from the experimenta group were slaughtered to detect the SE colonization. The production performance, egg quality and blood biochemical indices were also analyzed. Results: The results showed that the colonization rate of SE was highest in caecum contents (55.17%) and lowest in vagina (17.24%). For the eggs the detection rate of SE was highest on the eggshell (80.00%) and lowest in yolk (18.81%). SE infection had no significant influence on production performance and egg qualities (P 〉 0.05). The difference of laying rate between the experimental and control groups was less than 0.30%, and both were approximately equal to 82.00%. The blood analysis showed that the aspartic aminotransferase (AST) and alanine aminotransferase (ALT) of experimental group was significantly higher than those of control group (P 〈 0.05). For experimental and control groups AST values were 236.22 U/I and 211.84 U/I respectively, and ALT values were 32.19 U/I and 24.55 U/I. All of coefficients were less than 20%. The colonization of SE in organs increases the enzyme activities of AST and ALT in blood. Conclusions: SE in feed could invade the oviduct and infect the forming eggs. It significantly increased the concentration of ALT and AST in blood. Ho  相似文献   

8.
Background: Endoplasmic reticulum(ER) stress is associated with multiple pathological processes of intestinal diseases. Despite a critical role of mechanistic target of rapamycin complex 1(m TORC1) in regulating cellular stress response, the crosstalk between m TORC1 and ER stress signaling and its contribution to the intestinal barrier function is unknown.Results: In the present study, we showed that intestinal epithelial cells(IEC-6) incubated with tunicamycin led to caspase-3-dependent apoptotic cell death. The induction of cell death was accompanied by activation of unfolded protein response as evidenced by increased protein levels for Bi P, p-IRE1α, p-e IF2α, p-JNK, and CHOP. Further study demonstrated that tunicamycin-induced cell death was enhanced by rapamycin, a specific inhibitor of m TORC1.Consistently, tunicamycin decreased transepithelial electrical resistance(TEER) and increased permeability of the cells. These effects of tunicamycin were exacerbated by m TORC1 inhibitor.Conclusions: Taken together, the data presented here identified a previously unknown crosstalk between an unfold protein response and m TORC1 signaling in the intestinal epithelium. This feed-back loop regulation on ER stress signaling by m TORC1 is critical for cell survival and intestinal permeability in epithelial cells.  相似文献   

9.
《饲料工业》2010,(3):11-11
Recently, the Veterinary Bureau of Ministry of Agriculture publicized the plan on animal drug supervision in the latter half of 2010, requiring more stringent measures to be taken by the veterinary departments at all levels in an all-round way, focusing on the guaranteed quality of key vaccines for animal diseases and quality safety of animal products, so as to ensure the healthy development of animal husbandry and safeguard the safety of public hygiene.  相似文献   

10.
The majority of pregnancy loss in ruminants occurs during the first three weeks after conception, particularly during the period of conceptus elongation that occurs prior to pregnancy recognition and implantation. This review integrates established and new information on the biological role of ovarian progesterone(P4), prostaglandins(PGs),interferon tau(IFNT) and cortisol in endometrial function and conceptus elongation. Progesterone is secreted by the ovarian corpus luteum(CL) and is the unequivocal hormone of pregnancy. Prostaglandins(PGs) and cortisol are produced by both the epithelial cells of the endometrium and the trophectoderm of the elongating conceptus. In contrast, IFNT is produced solely by the conceptus trophectoderm and is the maternal recognition of pregnancy signal that inhibits production of luteolytic pulses of PGF2αby the endometrium to maintain the CL and thus production of P4. Available results in sheep support the idea that the individual, interactive, and coordinated actions of P4, PGs, IFNT and cortisol regulate conceptus elongation and implantation by controlling expression of genes in the endometrium and/or trophectoderm. An increased knowledge of conceptus-endometrial interactions during early pregnancy in ruminants is necessary to understand and elucidate the causes of infertility and recurrent early pregnancy loss and provide new strategies to improve fertility and thus reproductive efficiency.  相似文献   

11.
In order to understand the distribution and change of stable carbon isotope13C in grassland plants and the effects of soil moisture and temperature on the stable carbon isotope13 C composition (δ13 C), w e measured the δ13 C of shoots and living roots which both had two treatments, 13 C pulse labeling treatment and control treatment, and analyzed the effect of soil moisture content, air temperature and ground temperature on the δ13 C of plants body during the fast-growing stage (July-September) of the Leymus chinensis grassland in Inner Mongolia. The results showed that the δ13C of the living roots was 1-2% higher than the δ13C of the shoots in control treatments, and the δ13C of the shoots in13C pulse labeling treatment was significantly greater than the δ13C of the living roots. The variation trends of the δ13C value of shoots and living roots in labeling and control treatments were both in good consistency with time, which showed that the value of13C in shoots and living roots decreased at first, then increased, and then decreased during the growing season of plants. The δ13 C of the shoots and living roots in control group and living roots in13 C pulse labeling treatment had a linear negative correlation with soil moisture content in the layer of 0-20 cm, but the δ13C of shoots in13C pulse labeling treatment had Quadratic function relation with the soil moisture content in the layer of 0-20 cm, which indicated that the δ13C increased with increasing soil moisture content when it had a low soil moisture content, and the δ13C decreased when there was a high soil moisture content. In13 C pulse labeling treatment and control treatment, there were significant positive correlation between temperature and the δ13C of the shoots and living roots, the δ13C of the shoots and living roots increased with increasing the temperature. © 2019 China Agricultural University. All rights reserved.  相似文献   

12.
《饲料工业》2009,(1):7-9
China's State Council issued Regulations on Supervision and Administration of the Quality Safety of Dairy Products (hereinafter referred to as Regulations) on Oct 9, 2008. In order to fully implement the requirements of the Regulations, ensure the safety of dairy products, thoroughly overhaul and revive dairy industry and promote the steady and healthy development of dairy industry, Ministry of Agriculture (MOA) published Circular of the Ministry of Agriculture on Implementing the Circular of State Council on Regulations on Supervision and Administration of the Quality Safety of Dairy Products on Oct 10, conducting overall arrangement for the implementation of the Regulations.  相似文献   

13.
<正>The histological characteristics,distribution and variability of epidermal growth factor(EGF) and epidermal growth factor receptor(EGFR) during development of skin in the goat fetus were studied with histological and immunohistochemical methods.The results showed that the epidermis formed at the 6th gestational week,the thickness increased gradually because of transition from simple epithelium to stratified epithelium,and then decreased after the 15th week.The dermis was present at the 10th week,and the dermal derivatives appeared after the 11th week.All structures of the skin matured gradually during prenatal development.Low expression of EGF and EGFR could be observed at the 6th week and increased thereafter.Before the 11th week,EGF was mainly located in the cytoplasm of the basal layer of cells of epidermis,hair follicular epithelial cells and fibroblasts,and EGFR was mainly located on cell membranes of these cells.From the 11th to 16th week,the expression of EGF and EGFR extended from basal layer cells,prickle cells,hair follicular epithelial cells and fibroblasts to vascular endothelial cells,epithelial cells of sweat glands and arrector pili muscle.EGF was mainly detected cytoplasmically,and EGFR was located on membranes of these cells.From the 17th week to birth,EGF was mainly located in cells of the basal layer and hair follicular epithelial cells as the skin thinned and staining intensity continued to increase.The expressed amount of EGF and EGFR tended to increase throughout the whole development stage encompassed by gestational weeks 6 to 21 and the two components of the EGF signaling system were highly correlated.The results suggest that EGF and EGFR play important roles in the development of skin and its derivatives.  相似文献   

14.
In order to explore the effect of Leymus chinensis transplanting on the biodiversity and productivity of saline alkali grassland in Songnen Plain,a comparative experiment was conducted in the transplanting Leymus chinensis grassland. The results showed that the transplanting of Leymus chinensis enhanced plant species and the density of the grassland community. The total plant density under the transplanting of Leymus chinensis was 566.20 plant·m-2,6.85 times as much as that in the control (82.60 plant·m-2),and the difference between the treatments was significant (P<0.05),and the transplanting of Leymus chinensis increased the diversity index of Shannon-Wiener,the evenness index of Pielou and the richness of Margalf species. The total biomass of the community was higher than that in the control. In addition,the total biomass of the transplanting of Leymus chinensis was 357.77 g· m-2,2.14 times as much as that in the control (167.34 g·m-2),and the difference between the treatments was significant (P<0.05),which indicated that the transplanting Leymus chinensis increased the productivity of the plant community,and greatly increased the grassland output benefit, The total income was 3938.00 yuan·hm-2 for the transplanting of Leymus chinensis,7.37 times higher than that in the control (534.40 yuan·hm-2),and the difference between treatments was very significant (P<0.01).Transplanting technology of Leymus chinensis not only improved the biodiversity of the system,but also doubly increased the biomass and economic benefits,So it was a technical model which was worth of popularizing and applying in the saline alkali area of the Western Songnen Plain. © 2019 China Agricultural University. All rights reserved.  相似文献   

15.
南铭  李晶  赵桂琴  柴继宽  刘彦明 《草业学报》2022,31(11):172-180
Lodging is one of the important factors affecting yield and quality in oat crops. This research studied the physiological mechanisms of lodging resistance in oats,with a view to guiding future breeding. Mengyan 1 and Bayan 6 oat were included in this study as lodging-resistant varieties,while Dingyan 2 and Qingyin 2 were included as lodging-susceptible varieties. Data were collected on the morphological characteristics of basal elongation and differences in the contents of acid detergent fiber,neutral detergent fiber,cellulose and lignin and activities of key enzymes,for these oat cultivars with different lodging susceptibilities,so as to investigate the relationship between the lodging resistance of oats and the morphological characteristics and lignin content and synthase activity in the second-phase elongation at the base of stem. It was found that the amount of lodging among resistant cultivars was lighter and the lodging rate was lower than that of cultivars. The lengths of the second internode at the stem base of lodging easy cultivars were 34. 17% higher than those of lodging resistant cultivars. The internode diameter,stem wall thickness,stem weight,density,diameter,force and stem puncture force values of lodging resistant cultivars at the second internode of the stem base were,respectively,29.11%,26. 18%,25.80%,27.97%,34.61%,36.23% and 36. 60% higher than those of lodging-susceptible cultivars. The stem lignin and cellulose contents of cultivars resistant to lodging were significantly (P<0. 05) higher than those of cultivars susceptible to lodging. Lignin content was significantly (P<0. 01) positively correlated with the internode breaking force and puncture strength of the second internode at the stem base (r=0.9862 and r=0.9638,respectively),and significantly negatively correlated with the observed lodging rate(P<0.05,r=−0.9407). Lignin synthetase tyrosine ammonialyase,phenylalanine aminotransferase,cinnamyl alcohol dehydrogenase and 4-coumaric acid of CoA ligase in stems of lodging-resistant cultivars showed higher activities,resulting in accumulation of lignin at the internodes of the second elongation at the base of stem,which increased the lignification of cell walls and the mechanical strength of stems,and thus enhanced lodging resistance of the oats. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.  相似文献   

16.
刘志鹏  任广朋 《草业学报》2022,31(11):191-203
This review investigates the disordered status of the classification of Medicago genus,both domestically and internationally. Several definitions of a taxonomic species were considered and the names and characteristics of 13 Medicago species in China are reported,together with a detailed summary of the names,life forms,chromosome numbers,pollination methods and natural distribution of about 90 Medicago species worldwide,including the classification of 14 sections and 10 subsections in Medicago. The molecular evolutionary relationships between different species,and the geographical origin of Medicago are discussed,and the genetic relationships between different subspecies in the alfalfa complex are further explained. This study puts forward a method of identifying Medicago species on the basis of deep understanding of the concept of species. A wide collection of global Medicago germplasm resources,aiming to further clarify the evolutionary relationship among different sections and different species by molecular evolution methods is proposed. This review provides a reference framework for future Medicago classification and alfalfa cross breeding. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.  相似文献   

17.
Background: Flight is the central avian adaptation in evolution. Wing muscles form an important anatomical basis for avian flight, affecting wing performance and determine modes of flight. However, the roles of distal muscles in adjusting the wing, as well as their functional specializations, remain largely unknown. The importance of muscle fiber architecture has long been recognized. In this study, we provide quantitative anatomical data on the muscle architecture of the forelimb of the Golden Pheasant(Chrysolophus pictus), with an emphasis on brachial,antebrachial and manual segments.Methods: The forelimbs of five Golden Pheasants were dissected and detailed measurements of all muscles were made, including muscle mass, muscle belly length, fascicle length. From these values, muscle volume, physiological cross-sectional area(PCSA) and maximum isometric force were derived.Results: General trends such as the distribution of muscle mass, fascicle length and the ratio of tendon length/belly length are revealed. Comparing PCSAs between antebrachial depressors and elevators and between intrinsics of the alular digit and major digit yielded significant differences(p < 0.05). Pronounced development of the antebrachial depressors suggests that ventral rotation of the distal half of the wing is a pivotal factor in shape change and orientation modulation. Large PCSAs in tandem with the force generation capability of the major digit intrinsics may help stabilize the digits while enhancing support of the primary feathers. The architectural properties of the alular digit confirm that alular adjustment is essential to rapid adduction and abduction.Conclusions: These observations illustrate the underlying structural basis for the functional capacities of the distal forelimb muscles and may provide additional information useful in further biomechanical and in vivo investigations.  相似文献   

18.
王德利  王岭  韩国栋 《草业学报》2022,31(12):191-199
With the development of human understanding of the multi-functionality of grassland, coupled with the increasing demand for grassland ecological services, animal production and pastoral living, it is necessary to update the concept of grassland management, develop higher level livestock grazing and feeding technology based on multidisciplinary theories, and establish a more effective grassland grazing management paradigm. This study considers both the background and characteristics of the grassland resources and modern multi-dimensional social demands, and develops the concept of precise grassland grazing management which encompasses the versatility and stability of the grassland ecosystem and sustainability as the goal and the use of grassland science, animal science, ecology and other multi-disciplinary theories, based on the habitat conditions, especially the vegetation characteristics, livestock classes and their requirements, and livestock-vegetation interactions. Through multi-dimensional, effective and directional regulation of the livestock grazing process, the grassland management and utilization paradigm of synergistic balance between production and ecological functions can be finally realized. Also, the concepts and connotations of precise grazing and its relevant theoretical bases are systematically explained, including the plant compensatory growth mechanism, the intermediate disturbance hypothesis, the theory of diversifying grazing livestock, mechanisms of plant-animal interactions, nutrition regulation principles and versatility synergy. These concepts form a scientific basis for the regulation of grazing pressure and livestock assembly. In conjunction with this coverage, the key points in precision grazing are reviewed, such as dynamic optimal stocking rate(threshold), mixed grazing(species and proportion), remote sensing information options(satellite, unmanned aerial vehicle monitoring, large scale data processing)and other related supporting technologies. Finally, the authors sum up the concept of grassland multifunctionality as a goal of “combining productive function and ecological service in a win-win manner”, so providing a precise grazing management paradigm. This approach provides a principle for the integration of natural grassland grazing, grassland grazing with supplementary feeding, and drylot feeding, reflecting region-wide whole industry regulation of livestock grazing pressure/assembly and provision for animal nutrition, while aiming for grassland grazing systems to achieve an overall “livestock-vegetation balance”. Such a system will generate high quality animal products and sustainable ecological services. Precise grazing management of grassland is advanced, practical and extensive, and therefore is a desirable choice for future grassland management with great potential and prospect. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.  相似文献   

19.
Background: Feathers are a defining feature of birds with multiple functions such as flight, insulation, protection against predation and signaling. Feathers are lost during the annual molt while the rate of such loss at other times of the year and its fitness consequences remain poorly known.Methods: I used information on the number and the mass of feathers for 160 individuals belonging to 85 species of birds in general linear mixed models to analyze allometry of feathers and to investigate possible factors explaining variation in the number of feathers. A phylogenetic effect was assessed by quantifying the random effect of genus.Results: The total mass of feathers increased isometrically with body mass, while the total number of feathers and the mean mass of feathers showed negative allometry. Negative allometry implied that small-sized species had relatively many small feathers. There was a negative association between the number of feathers and migration distance. The total number of feathers initially increased during fall and winter, consistent with individuals growing more feathers later during the year or with individuals with fewer feathers selectively disappearing from the population. In contrast, the number of feathers decreased from winter through spring and summer.Conclusions: These findings suggest that thermoregulation has affected the evolution of the number and the size of feathers, there is selection against feather loss, and that the number of feathers varies across seasons.  相似文献   

20.
Background:Galacto-oligosaccharides(GOS)have been shown to modulate the intestinal microbiota of suckling piglets to exert beneficial effects on intestinal function.However,the modulation of intestinal microbiota and intestinal function by GOS in intestinal inflammation injury models has rarely been reported.In this study,we investigated the effects of GOS on the colonic mucosal microbiota composition,barrier function and inflammatory response of lipopolysaccharides(LPS)-challenged suckling piglets.Methods:A total of 18 newborn suckling piglets were divided into three groups,the CON group,the LPS-CON group and the LPS-GOS group.Piglets in the LPS-GOS group were orally fed with 1 g/kg body weight of GOS solution every day.On the d 14,piglets in the LPS-CON and LPS-GOS group were challenged intraperitoneally with LPS solution.All piglets were slaughtered 2 h after intraperitoneal injection and sampled.Results:We found that the colonic mucosa of LPS-challenged piglets was significantly injured and shedding,while the colonic mucosa of the LPS-GOS group piglets maintained its structure.Moreover,GOS significantly reduced the concentration of malondialdehyde(MDA)and the activity of reactive oxygen species(ROS)in the LPS-challenged suckling piglets,and significantly increased the activity of total antioxidant capacity(T-AOC).GOS significantly increased the relative abundance of norank_f_Muribaculaceae and Romboutsia,and significantly decreased the relative abundance of Alloprevotella,Campylobacter and Helicobacter in the colonic mucosa of LPS-challenged suckling piglets.In addition,GOS increased the concentrations of acetate,butyrate and total short chain fatty acids(SCFAs)in the colonic digesta of LPS-challenged suckling piglets.GOS significantly reduced the concentrations of interleukin 1β(IL-1β),interleukin 6(IL-6),tumor necrosis factor-α(TNF-α)and cluster of differentiation 14(CD14),and the relative mRNA expression of Toll-like receptor 4(TLR4)and myeloid differentiation primary response 88(MyD88)in the LPS-challenged suckling piglets.In addition,GOS significantly reduced the relative mRNA expression of mucin2(MUC2),and significantly increased the protein expression of Claudin-1 and zonula occluden-1(ZO-1)in LPS-challenged suckling piglets.Conclusions:These results suggested that GOS can modulate the colonic mucosa-associated microbiota composition and improve the intestinal function of LPS-challenged suckling piglets.  相似文献   

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