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Dynamical modelling of cardiac electrical activity using bidomain approach: The effects of variation of ionic model parameters

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Journal of Biomedical Science and engineering 2013年第6期6卷 598-608页

作者： Adebisi o. Ibrahim Adejumobi I. Adediji dada J. olufemi Department of electrical and electronics engineering Federal University of Agriculture Abeokuta Nigeria Manchester Institute of Biotechnology School of Computer Science The University of Manchester Manchester UK

This work presents the dynamical modelling of cardiac electrical activity using bidomain approach. It focuses on the effects of variation of the ionic model parameters on cardiac wave propagation. Cardiac electrical activity is governed by partial differential equations coupled to a system of ordinary differential equations. Numerical simulation of these equations is computationally expensive due to their non-linearity and stiffness. Nevertheless, we adopted the bidomain model due to its ability to reflect the actual cardiac wave propagation. The derived bidomain equations coupled with FitzHugh-Nagumo’s ionic equations were time-discretized using explicit forward euler method and space-discretized using 2-D network modelling to obtain linearized equations for transmembrane potential Vm, extracellular potential φe and gating variable w. We implemented the discretized model and performed simulation experiments to study the effects of variation of ionic model parameters on the propagation of electrical wave across the cardiac tissue. Time characteristic of transmembrane potential, Vm, in the normal cardiac tissue was obtained by setting the values of ionic model parameters to 0.2, 0.2, 0.7 and 0.8 for excitation rate constant ε1, recovery rate constant ε2, recovery decay constant γ and excitation decay constant β respectively. Changing the values of ε1, ε2 to 0.04 and 0.28 respectively, the obtained Vm showed a time dilation at 0.04 indicating cardiac arrhythmia but no significant change to Vm was observed at 0.28. Also, changing β to 0.3 and 1.1 and γ to 0.4 and 1.2 sequentially, there was no significant change to the time characteristic of Vm. The obtained results revealed that only decrease in ε1, ε2 impacted significantly on the cardiac wave propagation.

关键词： Dynamical Modelling Cardiac electrical Activity Bidomain Model Ionic Model Parameters Discretization Transmembrane Potential

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Language Policy in Nigeria and Nigerian Language Policy： Implications for effective Communication in Non-Monolingual Nations

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Sino-US english Teaching 2012年第11期9卷 1676-1685页

作者： Dare owolabi Samuel Ayodele dada ekiti State University Ado Ekiti Nigeria

In Nigeria, almost 500 indigenous languages continue to compete with the english language that has assumed the status of a global linguistic code. The contact, in different domains between english and indigenous languages in the country continues to affect performance in english and contact languages, making effective communication in either english or any of the indigenous languages unattainable. The purpose of this study is to show that although no particular document, so named, exists expressing the nation＇s policy on language, nonetheless, the country has a policy on language that accommodates the indigenous languages as substrates, while the english language holds sway in various linguistic domains. Using a simple descriptive survey with data from previous studies, this paper examines the linguistic implications of the contact between english and indigenous languages on the younger generations who are losing contact with the mother tongue, and also not demonstrating enough proficiency in the english language. It is recommended that the opportunities that competence and maturation afforded a second language learner should be latched onto to gain the needed proficiency in english thus making them effective bilinguals and communicators in a world that is fast becoming a global village, and the inhabitants global citizens.

关键词： language policy multilingualism bilingualism language contact effective communication

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Dietary effects of African walnut(Tetracarpidium conophorum)on the reproductive indices in male African catifsh(Clarias gariepinus)broodstock

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Journal of Coastal Life Medicine 2015年第6期 471-475页

作者： Adekunle dada oluwafunmilayo Aguda Department of Fisheries and Aquaculture Technology Federal University of TechnologyAkureOndo StateNigeria

objective:To investigate the effect of Tetracarpidium conophorum(***)seed powder as dietary supplementation on the reproductive indices in male Clarias gariepinus(***)***:Fifteen outdoor concrete tanks consisting of triplicates for each treatment group were *** groups of male ***[(303.22±1.89)g body weight]were fed with four diets supplemented *** seed powder respectively,a control diet without *** seed powder 2 times a day at 3%of body weight for 70 *** *** broodstocks[average individual weight,(303.22±1.89)g]were randomly distributed with density of 10 fish into 15 outdoor concrete *** the end of the 70-day experiment,gonado-somatic index and reproductive indices were ***:Fish fed experimental diets showed significantly improved gonado-somatic index and reproductive indices over the control *** gonado-somatic index and reproductive indices were recorded for the fish fed diet of 200 mg/kg *** seed powder compared to other experimental *** results indicated that supplement diets with medicinal plant(***)enhanced growth and improved gonado-somatic index,and reproductive indices of male *** ***:*** have a potential pro-fertility property which can be exploited in fish seed production by hatchery operators.

关键词： Medicinal plant Mudfish Gonadosomatic index Milt quality

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考虑资源灵活性的多区域综合能源系统协同调度

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电网与清洁能源 2024年第9期40卷 148-154页

作者：张浩陆海罗恩博李远陈淑敏王达达云南电网有限责任公司

为充分挖掘区域综合能源系统的运行灵活性，针对各类型灵活性资源进行建模，研究了多区域系统的协同调度方法。将区域综合能源系统内的灵活性资源分为固定和可移动两类，并对各类资源的灵活性特征进行数学表征；描述了考虑各类型设备的... 详细信息

为充分挖掘区域综合能源系统的运行灵活性，针对各类型灵活性资源进行建模，研究了多区域系统的协同调度方法。将区域综合能源系统内的灵活性资源分为固定和可移动两类，并对各类资源的灵活性特征进行数学表征；描述了考虑各类型设备的运行特性和多能网络的能流传输特性，并对多区域综合能源系统的各类型运行成本进行建模；建立了考虑资源灵活性的多区域综合能源系统协同调度模型。通过3类算例模型的仿真对比，论证了各类型灵活性资源及其可移动特性对于提升系统运行经济性、改善系统供能质量的有效作用，进一步挖掘了多区域综合能源系统的协调互补能力。

关键词：多区域综合能源系统灵活性资源能量枢纽协同调度

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Byrsocarpus coccineus Schumach.&Thonn.(Connaraceae)叶子提取物的降血糖和抗氧化活性(英文)

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中国天然药物 2013年第6期11卷 628-637页

作者： oluwakemi K.dada Abidemi J.Akindele olufemi A.Morakinyo Margaret o.Sofidiya Duncan ota Department of Pharmacology Faculty of Basic Medical SciencesCollege of MedicineUniversity of Lagos Department of Physiology Faculty of Basic Medical SciencesCollege of MedicineUniversity of Lagos Department of Pharmacognosy Faculty of PharmacyUniversity of Lagos

AIM: Diabetes Mellitus is associated with significant morbidity and mortality worldwide. The need for enhanced efficacy and safety, and cheaper and more readily available new drugs has increased the search for new antidiabetic drugs from plants. This study was conducted to investigate the antidiabetic activity of the hydroethanolic leaf extract of B. coccineus in rats. MeTHoDS: The effect of B. coccineus extract(100–800 mg·kg–1, p.o.) on blood glucose levels in normal and glucose loaded rats, and alloxan-induced diabetic rats was determined. After 10 days of treatment, blood samples were collected from rats for lipid and insulin profiling. Animals were thereafter sacrificed and the kidneys, heart, and liver were harvested for antioxidant indices assay. ReSULTS: In normal rats, B. coccineus did not cause significant reduction in blood glucose. At the dose of 800 mg·kg–1, significant increase in blood glucose level was not observed 30 min. after glucose load. B. coccineus administered acutely did not generally produce significant reduction in blood glucose level in diabetic rats. Administered subacutely, the extract significantly reduced blood glucose level in diabetic rats from the 3rdday with peak effect observed at the dose of 800 mg·kg–1on the 10thday. The extract generally preserved in vivo antioxidant levels in the kidneys, heart, and liver, increased the level of high density lipoprotein and insulin, and reduced the level of triglycerides and low density lipoprotein compared to diabetic control. CoNCLUSIoN: The findings in this study suggest that the hydroethanolic leaf extract Byrsocarpus coccineus possesses antidiabetic activity possibly mediated through inhibition of intestinal glucose absorption, in vivo antioxidant activity, and enhancement of regeneration of beta cells of the pancreas and insulin secretion.

关键词： Byrsocarpus coccineus Connaraceae Hypoglycemic activity Antioxidant activity Diabetes

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effects of soil physical properties on soil loss due to manual yam harvesting under a sandy loam environment

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International Soil and Water Conservation Research 2016年第2期4卷 121-125页

作者： Pius olufemi olusegun dada olusegun Rasheed Adeyanju olayemi Johnson Adeosun Johnson Kayode Adewumi Department of Agricultural engineering Federal University of AgricultureAbeokuta P.M.B.2240AbeokutaOgun StateNigeria

Soil degradation is a growing problem worldwide because it reduces the fertile top layer of the soil available for food production and one such degradative action is soil erosion due to the harvesting of *** loss due to crop harvesting with particular reference to yam tubers has not been quantified globally despite the fact that yam is a major staple food consumed worldwide and it is prevalent in many parts of *** yams in our environment is usually done with the soil attached to the yams due to the fact that farmers do not want additional work of removing soil attached to the *** study investigates the soil physical properties that influence soil loss due to yam harvesting in Abeokuta,South-Western Nigeria and to assess the quantity of soil loss due to yam *** on representative sampling area per location,yam tubers were harvested manually within the entire yam farmland from october to December *** weight,net weight and the amount of soil adhering to the yams were *** of soil physical properties such as soil moisture content,heap bulk density,inter-heap bulk density and soil texture were investigated with respect to soil *** results showed that moisture content ranged from 4%to 15%,heap bulk density ranged from 0.93 to 1.29 g cm^(-3) and inter-heap bulk density ranged from 1.03 to 1.50 g cm^(-3).They all had a positive correlation with soil *** particle size analysis for Federal University of Agricultural,Abeokuta(FUNAAB)and Alabata revealed that sand content was(86.78%and 88.32%),clay content(10.69%and 7.6%)and silt content,(2.53%and 4.08%)*** also revealed that clay content of the soil positively influenced the total soil loss during the yam *** mean soil losses in Federal University of Agriculture,Abeokuta(FUNAAB)and Alabata village yam farms were 4303 and 2125 kg/ha/harvest *** study also revealed that soil moisture content at harvesting time and clay

关键词： Heap bulk density Manual yam harvesting Soil degradation Soil loss Soil physical properties

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Implications of Cytogenetic Abnormalities and Azoospermia Factor Microdeletions in Assisted Procreation

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Journal of Reproduction and Contraception 2007年第3期18卷 231-235页

作者： Rima dada R Kumar M Bilal Shamsi Sarabpreet Singh Col R K Sharma A Varshney Laboratory of Molecular Reproduction and Genetics Department of AnatomyAIIMS N Delhi 110029 India Anatomy Department AIIMSN Delhi 110029 India ART centre Obstretics and Gynaecology Department Army Research and Referral hospitalNew Delhi India AIIMS N Delhi 110029 India

Assisted procreation techniques have revolutionized the management of infertility and have offered hope to millions of infertile couples. The main aim of these procedures is to produce healthy offspring. However recent studies on short term outcome of ART have reported a higher incidence of low birth weight, development delay, imprinting defects, sex and autosomal structural abnormalities, major and minor congenital malformation and certain cancers in babies conceived via ART. Further the health of ART conceived children beyond the neonatal period have been less well evaluated. A large number of infertile couples opting for ART have an underlying genetic aetiology. These genetic aberrations are iatrogenitically transmitted via ART. Thus it is important that all couples undergo a detailed and comprehensive genetic evaluation prior to ART.

关键词： genetics chromosomal abnormality AZF yq microdeletion assisted reproduction ART

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Growth, Nutrient Uptake efficiency and yield of Upland Rice as Influenced by Two Compost Types in Tropical Rainforest-Derived Savannah Transition Zone

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Agricultural Sciences 2014年第5期5卷 383-393页

作者： oyeyemi Adigun dada Adeniyi olumuyiwa Togun James Alabi Adediran Francis e. Nwilene African Rice Center International Institute of Tropical Agriculture (IITA) Ibadan Nigeria Department of Botany University of Ibadan Ibadan Nigeria Department of Crop Protection and environmental Biology University of Ibadan Ibadan Nigeria Institute of Agriculture Research and Training Ibadan Nigeria

Cultivating traditional upland rice cultivars on nutrient depleted soil causes poor and low yield. Little attention is paid to performance of inter-specific NeRICA cultivars grown on nutrient deficient soil augmented with different types of compost. Therefore, field trials were conducted during 2010 and 2011 planting seasons in Ibadan to evaluate growth, dry matter, nutrient uptake efficiency and grain yield of upland rice grown on nutrient deficient soil augmented with different types of compost. There were nine treatments comprising of three upland rice cultivars: NeRICA I, NeRICA II and ofada, two compost types applied at the rate of 8 t·ha-1: poultry dropping + maize stover (PDMC) and cattle dung + maize stover (CDMC) and control. The treatments were laid out in randomized complete block design and replicated three times. CDMC enhanced growth, nutrient use efficiency, dry matter and grain yield of upland rice cultivars. Performance of ofada was better than NeRICA cultivars. N (24.55 g), P (12.45 g) and K (35.41 g) uptake concentration and grain yield (5.45 t/ha) were highest in ofada plots augmented with CDMC. Residual effect of compost on growth, yield and nutrient uptake efficiency of upland rice on nutrient deficient soil was marginal.

关键词： NeRICA Compost Poor Soil Dry Matter Nutrient Uptake efficiency

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Case report：Cryptorchidism and AZF microdeletion

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Asian Journal of Andrology 2002年第2期4卷 148-148页

作者： R.dada N.P.Gupta 等 GeneticsDivision DepartmentofAnatomy DepartmentofUrology AllIndiaInstituteofMedicalSciencesNewDelhi－110029India

Cryptorchidism or undescended hidden testis is the most common disorder of sexual differentiation in man with an incidence of 4.5 % at birth and decreases to 0.8 % at 1 year of age until adulthood. Cryptorchidism is associated with impaired spermatogenesis due to high intra-abdominal temperature and increased incidence of testicular cancer. Cryptorchidism can be considered as a cause of infertility in 2 %~9 % of infertile patients, and in testicular cancer 5 %~10 % of men have a history of cryptor-chidism. It is known that the long arm of the y chromosome contains genes critical for spermatogenesis, the azoospermia factor (AZF)- AZFa, AZFb and AZFc. Deletion of any of these loci is associated with spermatogenic arrest at a particular stage of germ cell development and a characteristic testicular phenotype. During polymerase chain reaction (PCR) micro-deletion analysis of cytogenetically normal idiopathic male infertility patients, we found two cryptorchid cases with AZF microdeletion. Both cases (case 1 and 2) were azoo-spermic and had abdominal testis in the lumbar region. Follicular stimulating hormone (FSH) levels of the two cases were 6.8 and 41.3 mIU/ml, respectively. PCR microdeletion analysis was done using the guidelines and primers as prescribed by Simoni et al [1]. Case 1 showed deletion of AZFc loci ( STS deleted- sy254, sy255) and case 2, deletion of AZFb loci (STS deleted- sy127, sy134). Screening of literature showed only two published reports of AZF microdeletion in cryptorchidism by Foresta et al [2,3]. They found AZF microdeletions in all the 3 loci in 27.5% of the cryptorchid patients. Thus results of our preliminary study support findings of Foresta et al [2,3] that AZF microdeletions may lead to altered testicular response to mechanisms regulating testicular descent and finally lead to cryptorchidism. AZF microdeletion may lead to partial or complete spermatogenic arrest and the effect of a high testicular temperature may further worsen this cond

关键词：隐睾症合并症 AZF微缺失病例报告

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Analysis of Labour-Use Patterns among Small-Holder Cocoa Farmers in South Western Nigeria

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Journal of Agricultural Science and Technology(B) 2012年第1期2卷 107-113页

作者： Kassim Adekunle Akanni Alfred olayinka dada Department of Agricultural economics College of Agricultural Sciences Olabisi Onabanjo University Ago-lwoye Ogun StateNigeria

Labour is generally in short supply in peasant production particularly in the rural areas in Nigeria. There is also an unpredictable pattern of use of labour in cocoa farms. This has a negative implication on the level and quality of farm output among small holder farmers. The study investigated the effects of labour use patterns on productivity of cocoa farms in south western Nigeria. Multi-stage random sampling technique was used to select the respondents and the data were analyzed with the use of descriptive statistics and stochastic efficiency frontier function. Many farms （80%） were less than 5 hectares in size and sharecropping was the most dominant of the labour types on the farms. Adult male labour constituted about 69% of the total labour- use on the plantations and the majority of the labour was involved in the application of agrochemicals and harvesting of cocoa pods. The quantity of harvested cocoa beans, size of cleared understoreys and quantity of applied agrochemicals significantly affected （at 5% level） the labour-use efficiency in cocoa plantations. Poor remunerations often discourage prospective farm labour from participating in cocoa production. Better farm labour supply level could be achieved if the remuneration for farm labour is handsomely increased.

关键词： Farm labour productivity cocoa farms efficiency sharecropper.

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