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Studies on Vegetative and Reproductive Ecology of Paris polyphylla Smith: A Vulnerable Medicinal Plant 被引量:2
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作者 Chitta Ranjan Deb Sakutemsu L. Jamir Nangshimeren Sakutemsu Jamir 《American Journal of Plant Sciences》 2015年第16期2561-2568,共8页
Paris polyphylla Smith is an important medicinal plant that is considered vulnerable in many parts of the world. The species exhibits poor adaptability to changed environment and susceptible to climatic conditions for... Paris polyphylla Smith is an important medicinal plant that is considered vulnerable in many parts of the world. The species exhibits poor adaptability to changed environment and susceptible to climatic conditions for reproductive vigor. During the present study the species was studied in four different natural niches as well as synthetic habitats to check the adaptability to artificial conditions, its morphological and physiological characters and its interaction in its community so that conservation strategies could be worked out. The present study indicates that P. polyphylla exhibits healthy growth as well as reproduction in undisturbed area with canopy covers over 80%. The plant grows in well-drained rich humus soil and grows well with certain key associated species such as Quercus species, Taxus baccata, Aconitum species, Eupatorium adenophorum, Smilax species etc. Many plants were non-flowering and more than 60% were found non-flowering in its habitat during its flowering season in any particular year. There are clear morphological changes as the flowers stages from pre-fertilization to post-fertilization. Arrangement of anthers in two whorls shows a distinct and unique floral display. Light is an important factor during seed setting and less than 50% shade lowers the seed productivity very significantly. Predators such as slugs and snails are found on the plant. Urgent conservation and new innovative ways are necessary to propagate this economically important plant to ensure its continuity. 展开更多
关键词 Associated Species FLORAL BIOLOGY NICHE Characterization Primary Habitat reproductive BIOLOGY
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Exploring the reproductive ecology of the tropical semifossorial snake Ninia atrata
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作者 Teddy Angarita-Sierra Cesar Alejandro Lopez-Hurtado 《Zoological Research》 SCIE CAS CSCD 2020年第2期157-171,共15页
Based on histological analyses and field studies,this research describes the reproductive ecology of a population of Ninia atrata snakes inhabiting an oil palm plantation.Furthermore,through a multivariate approach,we... Based on histological analyses and field studies,this research describes the reproductive ecology of a population of Ninia atrata snakes inhabiting an oil palm plantation.Furthermore,through a multivariate approach,we explored the main drivers of reproductive output in N.atrata.Results showed that prey abundance and food intake were crucial variables contributing to reproductive output.Multiple linear regression models showed that neonates had high sensitivity(R2=55.29%)to extreme changes in climate,which was strongly related to slug and snail abundance variability and microhabitat quality.Reproductive cycles were markedly different between the sexes,being continuous in males and cyclical in females.Despite this variation,reproductive cycles at the population level were seasonal semi-synchronous.Constant recruitment of neonates all year,multiple clutches,high mating frequency,and continuous sperm production characterized the reproductive phenology of N.atrata.In addition,a significant number of previtellogenic females presented oviductal sperm as well as uterine scars,suggesting a high precocity in the species.The main drivers of reproductive output also differed between the sexes.In females,clutch size and secondary follicle variability were highly related to stomach bolus volume,fat body area,and body mass.In males,height of piles of palm leaves and body mass,rather than intrinsic reproductive traits,were the main drivers of sperm production.Nevertheless,in both cases,the relationship between body mass,prey abundance,and food intake suggests that N.atrata follows the income breeding strategy to compensate for reproductive costs and to maximize fitness. 展开更多
关键词 Continuous male reproduction Clutch mass Income breeding Iteroparity SPERMATOGENESIS OOGENESIS reproductive effort El Nino-Southern Oscillation(ENSO)
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Smart Approaches to Efficient Text Mining for Categorizing Sexual Reproductive Health Short Messages into Key Themes
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作者 Tobias Makai Mayumbo Nyirenda 《Open Journal of Applied Sciences》 2024年第2期511-532,共22页
To promote behavioral change among adolescents in Zambia, the National HIV/AIDS/STI/TB Council, in collaboration with UNICEF, developed the Zambia U-Report platform. This platform provides young people with improved a... To promote behavioral change among adolescents in Zambia, the National HIV/AIDS/STI/TB Council, in collaboration with UNICEF, developed the Zambia U-Report platform. This platform provides young people with improved access to information on various Sexual Reproductive Health topics through Short Messaging Service (SMS) messages. Over the years, the platform has accumulated millions of incoming and outgoing messages, which need to be categorized into key thematic areas for better tracking of sexual reproductive health knowledge gaps among young people. The current manual categorization process of these text messages is inefficient and time-consuming and this study aims to automate the process for improved analysis using text-mining techniques. Firstly, the study investigates the current text message categorization process and identifies a list of categories adopted by counselors over time which are then used to build and train a categorization model. Secondly, the study presents a proof of concept tool that automates the categorization of U-report messages into key thematic areas using the developed categorization model. Finally, it compares the performance and effectiveness of the developed proof of concept tool against the manual system. The study used a dataset comprising 206,625 text messages. The current process would take roughly 2.82 years to categorise this dataset whereas the trained SVM model would require only 6.4 minutes while achieving an accuracy of 70.4% demonstrating that the automated method is significantly faster, more scalable, and consistent when compared to the current manual categorization. These advantages make the SVM model a more efficient and effective tool for categorizing large unstructured text datasets. These results and the proof-of-concept tool developed demonstrate the potential for enhancing the efficiency and accuracy of message categorization on the Zambia U-report platform and other similar text messages-based platforms. 展开更多
关键词 Knowledge Discovery in Text (KDT) Sexual reproductive Health (SRH) Text Categorization Text Classification Text Extraction Text Mining Feature Extraction Automated Classification Process Performance Stemming and Lemmatization Natural Language Processing (NLP)
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现代集约化肉羊业主要关键技术研究与应用 被引量:1
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作者 赵有璋 李发弟 +11 位作者 姚军 张子军 王玉琴 蔡原 陈亚明 祝淑英 李永连 赵宗蕾 王敏芬 冯涛 郭健 杨富民 《中国草食动物》 2005年第2期3-9,共7页
专门化肉用种羊选定、引进后,通过适应性研究,在较大规模养羊业生产实践中,对现代集约化肉羊业的主要关键技术进行研究、完善和创新,组装集成并应用于生产。技术研究应用结果既为市场提供了大批专门化肉用种羊和优质安全的杂种肉羊,取... 专门化肉用种羊选定、引进后,通过适应性研究,在较大规模养羊业生产实践中,对现代集约化肉羊业的主要关键技术进行研究、完善和创新,组装集成并应用于生产。技术研究应用结果既为市场提供了大批专门化肉用种羊和优质安全的杂种肉羊,取得了高水平的研究成果及显著的经济效益和社会效益,又为我国目前正在迅速发展的集约化肉羊业提供了可靠的技术支持和理想的生产模式:从适宜的专门化肉羊品种到运用高效母羊快速扩繁技术,建立和完善有效的肉羊杂交利用体系,普遍应用种羊鲜、冻精生产大批肉用杂种羔羊,种植高产优质饲草及其科学加工调制和利用,建立严格兽医防疫制度,实行放牧+补饲或全舍饲的精细管理和集约化育肥,至生产优质、安全、标准肉羊,获得显著的经济效益和社会效益。 展开更多
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氧氟沙星对小鼠生殖毒性和致畸性的研究 被引量:1
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作者 沈红 吴国娟 +2 位作者 李焕荣 崔胜 程颖 《中国实验动物学报》 CAS CSCD 2005年第2期124-126,共3页
目的研究氧氟沙星对昆明系小鼠胚胎和胎鼠发育的影响,确定其是否存在生殖毒性和致畸性。方法①雄鼠分别灌服各剂量氧氟沙星,连续10d,末次给药24h后与母鼠合笼,在妊娠第三天取胚胎,记录各剂量组胚胎发育率。②孕鼠妊娠零天给药,分别经口... 目的研究氧氟沙星对昆明系小鼠胚胎和胎鼠发育的影响,确定其是否存在生殖毒性和致畸性。方法①雄鼠分别灌服各剂量氧氟沙星,连续10d,末次给药24h后与母鼠合笼,在妊娠第三天取胚胎,记录各剂量组胚胎发育率。②孕鼠妊娠零天给药,分别经口灌服高、中、低剂量[36、72和360mg(kg.bw)]氧氟沙星溶液,连续给药3d,在妊娠第三天收集胚胎,记录胚胎发育率。③孕鼠妊娠零天给药,分别经口灌服各剂量氧氟沙星溶液,连续给药10d,在妊娠第16天取出胎鼠,记录胎鼠体重、胎盘重、活胎数、胎鼠外观畸形和内脏畸形等指标。结果给药组与对照组相比,雄鼠服用高剂量组360mg(kg.bw)氧氟沙星对着床前胚胎发育影响显著(P<0.05),而中等剂量和低剂量组对着床前胚胎发育的影响不显著(P>0.05)。雌鼠服用不同剂量氧氟沙星对着床前胚胎发育影响不显著(P>0.05)。氧氟沙星对受孕鼠的活胎数和吸收胎数均无明显影响,给药组的活鼠体重、胎盘重均未见明显差异(P>0.05);药物组和对照组均未出现外观畸形和内脏畸形,也不存在剂量和效应关系。结论孕鼠服用不同剂氧氟沙星对昆明系小鼠胚胎和胎鼠发育无明显的影响,表明氧氟沙星对雌性鼠不具有明显的生殖毒性和致畸性;但雄鼠服用高剂量氧氟沙星对着床前胚胎发育影响显著。 展开更多
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Development and Validation of an Objective Risk Scoring System for Assessing the Likelihood of Virus Introduction in Porcine Reproductive and Respiratory Syndrome Virus-Free Sow Farms in the US
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作者 Derald J. Holtkamp Hui Lin +1 位作者 Chong Wang Dale D. Polson 《Open Journal of Veterinary Medicine》 2013年第2期168-175,共8页
The lack of validated tools to predict how long sow farms will remain PRRS virus-free following successful elimination of the virus has deterred veterinarians and producers from attempting to eliminate the PRRS virus ... The lack of validated tools to predict how long sow farms will remain PRRS virus-free following successful elimination of the virus has deterred veterinarians and producers from attempting to eliminate the PRRS virus from sow farms. The aim of this study was to use the database of PRRS Risk Assessments for the Breeding Herd in PADRAP to develop and validate an objective risk scoring system for predicting the likelihood of virus introduction in PRRS virus-free sow farms in the US. To overcome the challenges of dealing with a large number of variables, group lasso for logistic regression (GLLR) was applied to a retrospective dataset of PRRS Risk Assessment for the Breeding Herd surveys completed for 704 farms to develop the risk scoring system. The validity of the GLLR risk scoring system was then evaluated by testing its predictive ability on a dataset from a long-term prospective study of 196 sow farms to assess risk factors associated with how long PRRS virus-free sow farms remained PRRS virus-free. Receiver operator characteristic(ROC) curves were estimated to compare the performance of the GLLR risk scoring system to the risk scoring system based on expert opinion (EO), currently used in the PRRS Risk Assessment for the Breeding Herd, for predicting whether herds remained PRRS virus-free for 130 weeks. The GLLR risk scoring system (AUC, 0.76;95% CI, 0.67 - 0.84) performed significantly better than the EO risk scoring system (AUC, 0.36;95% CI, 0.27 - 0.46) for predicting whether to sow farms in the prospective study survived for 130 weeks (p 0.001). Dividing farms into 3 risk groups (low, medium and high) using a low and high cutoff values for the GLLR risk score was informative as the differences in the KM survival curves for the 3 groups were both clinically meaningful and statistically significant. The GLLR risk scoring system used in conjunction with the PRRS Risk Assessment for the Breeding Herd survey delivered through PADRAP appears to have the potential to help veterinarians predict the likelihood of virus introduction in PRRS virus-free sow farms in the US. 展开更多
关键词 Porcine reproductive and Respiratory Syndrome (PRRS) Group Lasso Logistic Regression Risk SCORING System Area under the ROC Curve
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Semantics Interaction Control for Constructing Intelligent Ecology of Internet of Things and Critical Component Research
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作者 Haijun Zhang Yinghui Chen 《Journal of Computer and Communications》 2018年第11期23-42,共20页
Intelligent equipment is a kind of device that is characterized by intelligent sensor interconnections, big data processing, new types of displays, human-machine interaction and so on for the new generation of informa... Intelligent equipment is a kind of device that is characterized by intelligent sensor interconnections, big data processing, new types of displays, human-machine interaction and so on for the new generation of information technology. For this purpose, in this paper, first, we present a type of novel intelligent deep hybrid neural network algorithm based on a deep bidirectional recurrent neural network integrated with a deep backward propagation neural network. It has realized acoustic analysis, speech recognition and natural language understanding for jointly constituting human-machine voice interactions. Second, we design a voice control motherboard using an embedded chip from the ARM series as the core, and the onboard components include ZigBee, RFID, WIFI, GPRS, a RS232 serial port, USB interfaces and so on. Third, we take advantage of algorithms, software and hardware to make machines “understand” human speech and “think” and “comprehend” human intentions to structure critical components for intelligent vehicles, intelligent offices, intelligent service robots, intelligent industries and so on, which furthers the structure of the intelligent ecology of the Internet of Things. At last, the experimental results denote that the study of the semantics interaction controls based on an embedding has a very good effect, fast speed and high accuracy, consequently realizing the intelligent ecology construction of the Internet of Things. 展开更多
关键词 DEEP Hybrid NEURAL Networks DEEP Bidirectional RECURSIVE NEURAL Network Speech Recognition Semantic Control Embedded Internet of THINGS INTELLIGENT ecology Construction
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广东佛山机场鸟类群落生态及鸟撞预防的研究 被引量:11
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作者 朱世杰 常弘 《中国媒介生物学及控制杂志》 CAS CSCD 北大核心 2005年第3期195-198,共4页
目的研究广东佛山机场及周边地区鸟类的生态规律和特征,提出切实可行的综合预防鸟撞措施,为鸟撞预防工作提供科学依据。方法按鸟类分布的生境选择固定样线,观察1年,数据分析采用密度、重要性值、分布系数等参数。结果通过对佛山机场及附... 目的研究广东佛山机场及周边地区鸟类的生态规律和特征,提出切实可行的综合预防鸟撞措施,为鸟撞预防工作提供科学依据。方法按鸟类分布的生境选择固定样线,观察1年,数据分析采用密度、重要性值、分布系数等参数。结果通过对佛山机场及附近6种生境的6条样带调查,记录到鸟类49种,分属10目23科。重要性值分析表明,最重要的种类有6种,即池鹭、白鹭、小白腰雨燕、家燕、金腰燕、白头鹎。按鸟类的生境分布系数划分,广性分布有16种,占总种数的32.7%,构成了佛山机场各生境鸟类群落组成的主体。结论根据佛山机场和附近的鸟类组成及时空特征分析,构成鸟撞隐患的种类主要是水鸟和其他湿地鸟类。每年春季(3~5月)和秋季(9~11月)是鸟撞事件发生几率最大的季节。 展开更多
关键词 广 湿
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高丹草新品种在河北平原农区的引进筛选 被引量:7
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作者 刘贵波 乔仁甫 《中国农学通报》 CSCD 2005年第6期383-386,394,共5页
在河北平原农区,通过对国内外11个高丹草新品种的产草量、粗蛋白产量、物候期、分蘖力、再生性、株高等性状的研究分析,结果表明:以青饲、青贮饲喂牛为目的,表现最好的品种为健宝,不仅产草量高、粗蛋白产量、分蘖能力、再生性、长势均... 在河北平原农区,通过对国内外11个高丹草新品种的产草量、粗蛋白产量、物候期、分蘖力、再生性、株高等性状的研究分析,结果表明:以青饲、青贮饲喂牛为目的,表现最好的品种为健宝,不仅产草量高、粗蛋白产量、分蘖能力、再生性、长势均较好。其次为晋草1号、瑞奥3号。高丹草在河北平原农区春播、夏播均可,春播可刈割三次,夏播可刈割二次。 展开更多
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Dietary supplementation of laminarin improves the reproductive performance of sows and the growth of suckling piglets
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作者 Pengguang Zhang Guoyuan Jiang +6 位作者 Chenghong Ma Yubo Wang Enfa Yan Linjuan He Jianxin Guo Xin Zhang Jingdong Yin 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第1期329-343,共15页
Background Maternal nutrition is essential in keeping a highly efficient production system in the pig industry.Laminarin has been shown to improve antioxidant capacity,reduce the inflammatory response,and favor the ho... Background Maternal nutrition is essential in keeping a highly efficient production system in the pig industry.Laminarin has been shown to improve antioxidant capacity,reduce the inflammatory response,and favor the homeostasis of intestinal microbiota.However,the effect of dietary supplementation of laminarin on the reproductive performance of sows and the growth of suckling offspring remains unknown.Methods A total of 40 Landrace×Yorkshire multiparous sows on d 85 of gestation,similar in age,body weight(BW),parity and reproductive performance,were randomly divided into four dietary treatments with 10 sows per treatment,receiving a control diet(basal pregnancy or lactating diets)and a basal diet supplemented with 0.025%,0.05%and 0.10%laminarin,respectively.The experiment lasted from d 85 of gestation to d 21 of lactation.Results Laminarin supplementation linearly increased number born alive per litter(P=0.03),average daily feed intake(ADFI,P<0.01),and total milk yield of sows during the lactation of 1–21 d(P=0.02).Furthermore,maternal laminarin supplementation increased the average daily gain(ADG)of piglets while tending to reduce the culling and death rate before weaning.In addition,alterations to the composition of colostrum and milk,as well as to serum inflammatory cytokines and immunoglobulins of sows were observed.The fecal microbiota profile of sows supported the improvement of reproductive performance in sows and the growth performance in suckling offspring.Conclusions Dietary supplementation of laminarin during late pregnancy and lactation could significantly improve reproductive performance of sows and growth performance of piglets. 展开更多
关键词 Fecal microbiota LAMINARIN MILK PIGLETS reproductive performance SOWS
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波尔山羊批量胚胎移植莎能奶山羊 被引量:3
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作者 沈文正 马建涛 严飞 《西北农业学报》 CAS CSCD 北大核心 2005年第2期1-4,共4页
采用阴道栓+FSH超数排卵,经产供体波尔山羊22只,在放栓后第9~11天,连续4d递减量肌肉注射FSH。22只供体羊发情与纯种波尔山羊种公羊配种后第7天,手术回收输卵管中早期发育胚胎再经手术移入同期发情的受体奶山羊输卵管内妊娠产仔。结果表... 采用阴道栓+FSH超数排卵,经产供体波尔山羊22只,在放栓后第9~11天,连续4d递减量肌肉注射FSH。22只供体羊发情与纯种波尔山羊种公羊配种后第7天,手术回收输卵管中早期发育胚胎再经手术移入同期发情的受体奶山羊输卵管内妊娠产仔。结果表明:1获得373枚早期胚胎,其中A级胚胎占31.1%(85/273),B级胚胎占49.5%(135/273),异常胚胎占19.4%(53/273)。2将167枚7日龄可用胚胎(A级和B级)移植147只受体羊输卵管内,移植后35d,妊娠98只,妊娠率为67%(98/147),83只羊足月产羔为89只,产羔率为85%(89/98),20只受体移植了两枚胚胎,只有6只产双羔。3羔羊出生重平均为3.7±0.54kg。每只供体羊平均产羔4.05只。胚胎移植所得羔羊的初生重与自然繁殖波尔羔羊无显著差异(P>0.05)。试验证明,山羊胚胎移植计划可使良种群体繁殖率提高3~5倍,优秀个体繁殖力提高6~8倍,从而加快纯种山羊的繁殖。 展开更多
关键词 FSH
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Sexual Dimorphism and Female Reproductive Characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China
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作者 Yu DU Xiaming ZHU +2 位作者 Chixian LIN Yuntao YAO Xiang JI 《Asian Herpetological Research》 SCIE CSCD 2024年第1期49-58,共10页
We studied sexual dimorphism in body size and shape and female reproductive characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China.In our sample the largest female and male were 61.1 ... We studied sexual dimorphism in body size and shape and female reproductive characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China.In our sample the largest female and male were 61.1 and 55.2 mm snout-vent length(SVL),respectively.The mean SVL was larger in adult females(52.0 mm)than in adult males(48.3 mm).Juveniles were sexually dimorphic in head length but not in other examined morphological variables.Adult males were longer in head length and shorter in abdomen length and fore-limb length than adult females of the same SVL.Ontogenetic shifts in sexual dimorphism in body shape were evident,as revealed by the fact that morphological differences between the sexes were more pronounced in adults than in juveniles.Females produced a single litter of 3–6 offspring per season from early August to early September.Litter size,litter mass and offspring(neonate)mass were positively related to female SVL.Neonate mass was independent of relative fecundity.From the above findings we draw three main conclusions.First,females are the larger sex in T.hainanus,and sexual dimorphism in body shape is more pronounced in adults than in juveniles.Second,larger female T.hainanus produce more and larger offspring and thus heavier litters than smaller ones.Third,the offspring size-number trade-off does is not evident in T.hainanus. 展开更多
关键词 FECUNDITY morphology offspring size-number trade-off REPRODUCTION SCINCIDAE sexual dimorphism
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Sexual and Reproductive Health Knowledge and Behaviour among Adolescents in Rural Burkina Faso
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作者 Yobi Alexis Sawadogo Issa Ouédraogo +6 位作者 Sibraogo Kiemtoré Ali Sie Clarisse Dah Adama Ouattara Hulda W. Nana Emmanuel Ouedraogo Charlemagne Ouedraogo 《Open Journal of Obstetrics and Gynecology》 2024年第9期1422-1430,共9页
Background: Adolescents in developing countries have limited knowledge about the prevention of STIs and unwanted pregnancies. In several African countries, risky sexual behaviour persists, including early sexual debut... Background: Adolescents in developing countries have limited knowledge about the prevention of STIs and unwanted pregnancies. In several African countries, risky sexual behaviour persists, including early sexual debut, multiple sexual partners, economic and sexual exchange, and low condom and contraceptive use. The purpose of this study is to assess the sexual and reproductive health knowledge and behaviour of adolescents in rural Burkina Faso in order to improve their sexual and reproductive health. Method: This was a descriptive cross-sectional study with prospective data collection conducted from 07 March to 04 April 2022 in the area of the Demographic and Health Surveillance System of the Nouna Research Centre. A questionnaire was administered to a randomly selected sample of 1202 adolescents. Results: The mean age of the adolescents was 14.1 years and 56.6% were male. Only 58.2% of the adolescents had ever heard of HIV/AIDS. Of these, 95.7% did not know their HIV status. In addition, 15.8% had ever had sexual intercourse and 2.4% had been sexually active at an early age. Almost 45% had not used any contraceptive method the last time they had sex. Condoms were the most frequently used contraceptive method (47.4%). Among teenagers, 27.6% had been pregnant at least once, 7.3% were married and the average age at marriage was 18.45 years. Almost 7% (6.9%) of teenagers had more than one sexual partner. Conclusion: Adolescents have limited knowledge about reproductive health. Risky sexual behaviour persists. Awareness campaigns need to be intensified to improve their sexual and reproductive health. 展开更多
关键词 KNOWLEDGE BEHAVIOUR reproductive Health Adolescents Nouna Burkina Faso
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Feeding ecology and interactions with mammal hosts in a symbiotic genus of birds(Buphagus spp.)in Namibia
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作者 Michael S.Lukubwe Daniel Velarde-Garcéz +3 位作者 Fernando Sequeira Susana Lopes Adrian J.F.K.Craig Vanessa A.Mata 《Avian Research》 SCIE CSCD 2024年第3期336-344,共9页
As the sole obligate symbiotic birds in Africa,oxpeckers offer a unique model for studying symbiotic relationships.Due to the multitrophic level they occupy and the context dependent foraging behavior they exhibit,the... As the sole obligate symbiotic birds in Africa,oxpeckers offer a unique model for studying symbiotic relationships.Due to the multitrophic level they occupy and the context dependent foraging behavior they exhibit,the type of symbiotic relationship can be variable.In addition to providing a cleaning service to the host by removing ticks,oxpeckers frequently feed on blood,mucus,and saliva,inflicting potential damage on the host.Here,we used DNA metabarcoding on faecal samples to analyze the taxonomic composition of the trophic interactions of the Yellow-billed Oxpecker(Buphagus africanus)and Red-billed Oxpecker(B.erythrorhynchus)in northeastern Namibia.In contrast to conventional methods,DNA metabarcoding allows for a detailed identification of dietary resources encompassing both mammal hosts and consumed arthropods within the same samples.With this information,we examined differences in the diet composition between oxpecker species and localities,as well as the co-occurrence between host and arthropod species.Our findings revealed that oxpeckers predominantly source their diet from mammals,ticks,and flies;however,ticks and flies rarely co-occur in the diet of an individual.We observed variability among individuals in their feeding ecology,which is strongly correlated with locality and,to a lesser extent,with the mammal host.We noted a high degree of mobility between hosts within relatively short periods,with 32%of the samples showing traces of at least two mammal hosts.This study illustrates the dynamic foraging behavior of these specialized symbiotic birds,shedding light on their potential role in pest control services and disease transmission. 展开更多
关键词 COMMENSALISM Diet DNA metabarcoding Oxpeckers PARASITISM Trophic ecology
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Reproductive Biology of a Blue-tail Skinks(Plestiodon)Population from a Temperate Forest,East-central Puebla,México
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作者 Manuel FERIA-ORTIZ Isaías hazarmabeth SALGADO-UGARTE 《Asian Herpetological Research》 SCIE CSCD 2024年第3期183-193,共11页
We studied the cycles of reproduction and fat bodies of a blue-tailed skink population of an undescribed species of the Plestiodon brevirostris group.Sexual maturity is attained by females and males as they both reach... We studied the cycles of reproduction and fat bodies of a blue-tailed skink population of an undescribed species of the Plestiodon brevirostris group.Sexual maturity is attained by females and males as they both reach about 59 mm of SVL.Vitellogenesis started in June-July,with ovulation occurring during late-October to mid-November,and parturition in mid-spring.Litter size varied from two to six,with a mean of 3.86±0.15 embryos in uterus,and showed a positive correlation with female body mass and SVL.During gestation,a significant increase in the average wet mass of embryos in uterus was evident.In comparison,there were no notable changes in the average dry mass.Juvenile growth data suggest that sexual maturity,both males and females,is reached at 16-17 months of age.Testicles and epididymides exhibited maximal weight during August-September.Testicular regression occurred in September.Mating apparently takes place from mid-summer to early fall.Lipids stored in female fat bodies are used for vitellogenesis and for nutrition during the winter months.In males,the stored lipids appear to be used in reproductive activities during the mating season. 展开更多
关键词 growth litter size minimum size at maturity reproduction SCINCIDAE VIVIPARITY
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Genome-wide SNP markers provided insights into the reproductive strategy and genetic diversity of the green tide causative species Ulva prolifera in China
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作者 Song SUN Weiwei MA +2 位作者 Nan WANG Song FENG Yan SUN 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第2期533-543,共11页
Ulva prolifera is the causative species of the annually occurring large-scale green tides in China since 2007.Its specific biological features on reproductivity strategies,as well as intra-species genetic diversity,ar... Ulva prolifera is the causative species of the annually occurring large-scale green tides in China since 2007.Its specific biological features on reproductivity strategies,as well as intra-species genetic diversity,are still largely unknown,especially at the genome level,despite their importance in understanding the formation and outbreak of massive green tides.In the present study,the restriction site-associated DNA genotyping approach(2b-RAD)was adopted to identify the genome-wide single-nucleotide polymorphisms(SNPs)of 54 individual thalli including samples collected from Subei Shoal in 2019 and Qingdao coast from 2019 to 2021.SNPs genotype results revealed that most of the thalli in 2019 and 2020 were haploid gametophytes,while only half of the thalli were gametophytes in 2021,indicating flexibility in the reproductive strategies for the formation of the green tides among different years and the dominance of asexual and vegetative reproductive mode for the floating period.Besides,population analysis was conducted,and it revealed a very low genetic diversity among samples from Subei Shoal and the Qingdao coast in the same year and a higher divergence among samples in different years.The results showed the efficiency of 2b-RAD in the exploration of SNPs in U.prolifera and provided the first genome-wide scale evidence for the origin of the large-scale green tides on the Qingdao coast.This study improved our understanding of the reproductive strategy and genetic diversity of the green tide causative species and will help further reveal the biological causes of the green tide in China. 展开更多
关键词 green tide Ulva prolifera 2b-RAD single-nucleotide polymorphism(SNP) reproductive strategy genetic diversity
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寄主植物对甜菜夜蛾的发育和繁殖及体内酯酶活性的影响 被引量:17
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作者 李子玲 韦绥概 +3 位作者 韦飚 梁忠毅 杨海菊 王仕红 《昆虫知识》 CAS CSCD 北大核心 2005年第3期284-289,共6页
在恒温(2 8±1 )℃条件下考察了葱、苋菜、豇豆、蕹菜、菜心5种寄主植物对甜菜夜蛾SpodopteraexiguaH櫣bner的营养效应及体内羧酸酯酶、乙?铛ッ富钚缘挠跋?,结果表明,不同寄主植物对甜菜夜蛾幼虫和蛹的发育历期、存活率、蛹... 在恒温(2 8±1 )℃条件下考察了葱、苋菜、豇豆、蕹菜、菜心5种寄主植物对甜菜夜蛾SpodopteraexiguaH櫣bner的营养效应及体内羧酸酯酶、乙?铛ッ富钚缘挠跋?,结果表明,不同寄主植物对甜菜夜蛾幼虫和蛹的发育历期、存活率、蛹重、雌成虫产卵量等有显著影响,其中对雌成虫产卵量的影响最大。雌成虫产卵量最高为取食菜心的处理,其次是取食葱的处理。寄主植物对甜菜夜蛾体内羧酸酯酶、乙酰胆碱酯酶活性也有显著影响,但这些酶的活性与发育历期、存活率、产卵量无明显相关性。在进行预测预报、田间防治时应充分考虑寄主植物对甜菜夜蛾发育历期、产卵量、解毒酶活性的影响。 展开更多
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几种生态种植模式的环境生态经济效应研究 被引量:3
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作者 姚荣江 何丙辉 《中国农学通报》 CSCD 2005年第4期295-299,333,共6页
在三峡库区典型紫色土坡耕地,设置了四种生态种植模式,进行经济和生态环境效应的研究。结果表明:投入产出比,梨×连翘/花生>桃×连翘/花生>桃/花生>梨/花生>CK,其中梨×连翘/花生与桃×连翘/花生模式分别... 在三峡库区典型紫色土坡耕地,设置了四种生态种植模式,进行经济和生态环境效应的研究。结果表明:投入产出比,梨×连翘/花生>桃×连翘/花生>桃/花生>梨/花生>CK,其中梨×连翘/花生与桃×连翘/花生模式分别比对照提高69.9%和65.5%,;影响果树冠幅的主要因子是土层厚度、坡位与种植模式;套种连翘的二种模式须根量明显比其它模式高,树种根系分布特征、种植密度和土层厚度是影响须根量的主要因素;种植模式和坡位均显著影响土壤孔隙度的发育,各种植模式的土壤孔隙度顺序:梨×连翘/花生>桃×连翘/花生>桃/花生>梨/花生>CK,随坡位的升高土壤孔隙度呈降低的趋势;各生态种植模式土壤肥力均比对照有所提高,乔、灌、草结合是一种较好的维持土壤肥力模式。结合生态、经济指标,三峡库区紫色土丘陵区可推广梨×连翘/花生模式与桃×连翘/花生两种模式。 展开更多
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大亚湾海域营养盐与叶绿素含量的变化趋势及其对生态环境的影响 被引量:66
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作者 丘耀文 王肇鼎 朱良生 《台湾海峡》 CAS CSCD 北大核心 2005年第2期131-139,共9页
分析了近20a来大亚湾海域营养盐和叶绿素a含量的时空变化规律及其对生态环境的影响.结果表明:大亚湾海域水体中NH3N、NO3N、NO2N、PO4P、SiO3Si、DIN、叶绿素a的多年平均含量分别为1.73±0.89、1.55±0.86、0.30±0.25、3.5... 分析了近20a来大亚湾海域营养盐和叶绿素a含量的时空变化规律及其对生态环境的影响.结果表明:大亚湾海域水体中NH3N、NO3N、NO2N、PO4P、SiO3Si、DIN、叶绿素a的多年平均含量分别为1.73±0.89、1.55±0.86、0.30±0.25、3.57±1.55、0.33±0.35、22.03±9.40μmol/dm3和2.47±1.28μg/dm3.自1991年以来,水体中活性磷酸盐的含量有较大幅度的下降,溶解态的无机氮的含量则上升,活性硅酸盐的含量变化较小.大亚湾大部分水体属于贫营养水平,养殖海区水体属于中营养水平.大亚湾海域水体的N/P平均值为21.69±19.38.浮游植物的生长从过去的氮限制转变为现在的磷限制.大亚湾海域营养盐含量和结构的改变,已对该海湾生态系统产生了一定的影响,如浮游植物的小型化和渔获量的大幅下降等. 展开更多
关键词 绿 绿a NH3-N NO3-N 1991 20a DIN mol
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生态旅游区容量控制的三维框架 被引量:3
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作者 戴光全 张骁鸣 《规划师》 2004年第11期101-105,共5页
设计生态旅游区容量控制体系需正确处理旅游区内自然生态本底特征与居民基本利益的相互关系,以及正确处理旅游区经营主体基本利益和游客基本利益的相互关系。广东省韶关市曲江县韶石山生态旅游区在旅游产品的设计上,一方面要从区域合作... 设计生态旅游区容量控制体系需正确处理旅游区内自然生态本底特征与居民基本利益的相互关系,以及正确处理旅游区经营主体基本利益和游客基本利益的相互关系。广东省韶关市曲江县韶石山生态旅游区在旅游产品的设计上,一方面要从区域合作的角度出发,考虑整个丹霞山风景名胜区的整体特色和可持续发展;另一方面要从旅游营销的角度准确定位目标市场,确立“独特卖点”。 展开更多
关键词 广
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