Effect of Curing Treatments on Seven Key Farmers’ Yams (<i>Dioscorea</i>spp.) in Ghana

Curing of freshly harvested yams (Dioscorea spp.) is a process for wounded yams during harvest to heal. In this work the effectiveness of straw, polypropylene and jute sack on curing of seven key farmers’ yam varieties over a duration of 7, 14 and 21 days was studied. Seven key farmers’ yam varieties identified as Pona, Lariboko, Dente, Mutwumudoo, Serwah belonging to D. rotundata, Matches and Akaba belonging to D. alata were studied under different curing treatments. The percentage weight loss of yam tubers varied among the treatments over curing period. Curing under jute sack showed all yam varieties had weight losses less than 2.0%, within 7 days of curing. Five different varieties had weight loss less than 2.0% except Dente under the straw treatment. Mutwumudoo variety showed the highest water loss (8.4%) for polypropylene sheet and 6.9% for Lariboko in the control treatment. During 7 days curing the control and polypropylene treatment did not support yam curing. After 14 days of curing of tubers, similar tends were observed as in 7 days curing. After 14 days of curing under jute sack, percentage weight loss of the tubers ranges from 2.0% - 3.7%. In the straw treatment, the percentage weight loss ranges between 1.0% - 4.7% in all other varieties except Dente (D. rotundata) (8.2%). Polypropylene sheet treatment showed the highest percentage weight loss in Mutwumudoo variety (18.4%). A similar trend was observed for the yam tubers cured for 21days as percentage weight loss of tubers under jute sacks was 2.5 – 9.8%. Curing temperature and humidity ranged between 27&degC - 40&degC and 87% - 100% rh for yam tubers under the three different treatments of polypropylene, jute and straw. However, the control treatment recorded lower humidity of 60% - 80% rh. Curing material, duration, climatic conditions and yam varieties influenced curing and Serwah variety, which is a D. rotundata is the best bet yam variety to cure under jute sack for 7, 14 and 21 days of curing.

Effect of Climate Variability on Yams (<i>Dioscorea spp</i>.) Production in Central and Northern Benin

Climate change poses an important constraint to agricultural sector and food security in tropical African countries dominated by rain-fed agriculture. This research focuses on the effects of climate variability on yam production in central and northern Benin. Daily climate data such as temperatures, precipitation, potential evapotranspiration, relative humidity and insolation from 1981 to 2016 were collected at the direction of METEO-Benin. A survey was then conducted with 351 producers to collect their perceptions of the effect of climate variability on the yams production. Descriptive statistics, principal component analysis (PCA) followed by trend analyses, Lamb index calculations and the agro-climatic stress index were carried out. The distribution of rain during the yam cycle (91.5% of those surveyed), the ambient temperature (84.9%), insolation (83.5%), the amount of rainwater that fell during the rainy season (82.2%) and the harmattan (53.3%) are perceived by sociolinguistic groups as climatic factors affecting the growth, the tuberization and yield of yams according to the producers. The results indicate an upward trend in temperature over the period 2001 to 2016 in the transition zone (28.4°C) and in the Northeast (27.76°C) and over the period from 2001 to 2011 in the North-West of Benin (27.71°C), where the average annual temperature during these periods is higher than normal (27.82°C in the center, 27.44°C in the Northeast and 27.42°C to the northwest). This research also shows an instability of the rains with a regular decrease in the rainfall in the Centre and the North-East of the country. The agro-climatic stress index (ISA) and above all the annual rainfall constitute the main climatic factors which determine the yield of yam in the various growing areas in Benin. The average annual temperature and that of January in the transition zone, the rains of January and April in the North-East zone and the relative humidity in the North-West zone also probability determine the yield of the yam.

Production of Yam Tubers Using Seed Tubers from Vitroplants Regenerated from Aerial Stems in the Yam Species Dioscorea alata (L.) and Dioscorea cayenensis-rotundata (L. & P.) in Côte d’Ivoire

The aim of this study is to produce large quantities of yam tubers in the field from seed tubers derived from vitroplants regenerated from aerial stem cuttings and farmers’ tuber seeds. Seed tubers from ten yam cultivars, including five from Dioscorea alata (cDa083, cDa053, cDa115, cDa150 and cDa266) and five from Dioscorea cayenensis-rotundata (cDr015, cDr027, cDr150, cDr206 and cDr148) with distinct agro-morphological characteristics, were used as material. A completely randomized block design with 3 replications was used. In each block, all cultivars and seed types were represented. When put into cultivation, the tubers produced by the vitroplants all germinated and gave 100% healthy plants, compared with 86% to 100% healthy plants for the seed tubers produced by the farmers. Yields per hectare ranged from 10 to 25 tonnes for seed tubers produced by in vitro plants, and from 4 to 9 tons for seed tubers produced by farmers. Seed tubers from vitroplants can therefore be recommended to farmers as a solution to the problem of seed tuber unavailability.

用于高风险环境安全监测和可调热管理的具有分层核壳结构的耐化学品纱线

Chemical resistant textiles are vital for safeguarding humans against chemical hazards in various settings.such as industrialproduction,chemicalaccidents,laboratory activities,and road transportation.However,the ideal integration of chemical resistance,thermal and moisture management,and wearer condition monitoring in conventional chemically protective textiles remains challenging.Herein,the design,manufacturing,and use of stretchable hierarchical core-shell yarns(HCSYs)for integrated chemical resistance,moisture regulation,and smart sensing textiles are demonstrated.These yarns con-tain helically elastic spandex,wrapped silver-plated nylon,and surface-structuredpolytetrafluo-roethylene(PTFE)yarns and are designed and manufactured based on a scalable fabrication process.In addition to their ideal chemical resistance performance,HCSYs can function as multifunctional stretch-able electronics for real-time human motion monitoring and as the basic element of intelligent textiles.Furthermore,a desirable dynamic thermoregulation function is achieved by exploiting the fabric structure with stretching modulation.Our HCSYs may provide prospective opportunities for the future development of smart protective textiles with high durability,flexibility,and scalability.

Efficiency of Legumes in Increasing Yam Yield under Sandy Ferrasol in the Forest Zone of Southwestern Côte d’Ivoire

The cropping system is based on traditional farming in rural areas. In this way, yields of some food crops like yam are very low considering their high need for nutrients. The nutrient-rich land is under high land pressure as it is occupied by cash crops such as oil palm and rubber at the expense of food crops and soil fertility is declining. The study was conducted in Grand-Lahou to assess the effect of organic matter provided by legumes in increasing yam yield. The randomized complete block design included four (4) treatments: Arachis hypogaea + yam association (T1), Acacia mangium + yam association (T2), Arachis + Acacia mangium + yam association (T3) and pure yam crop (T0). The parameters measured were: the soil nutrients content, the rate of mineralization of organic matter through the C/N ratio as well as the yield of yam through different techniques that allowed the objective of the study to be achieved. It was noted a slight improvement of nitrogen and organic carbon in all treatments with a higher value recorded in the T2 treatment. The C/N ratio decreased to 12 in all treatments compared to the control, which reflects a normal decomposition of the organic matter. Treatment T1 increased yam yield (8.4 t/ha) in contrast to treatments T2 (4.1 t/ha) and T3 (2.8 t/ha). Legume-based treatments T2 and T3 were associated with a significant decrease in yam yield, resulting in losses of −46.34% to −25.09%, while treatment T1 resulted in a gain of 28.57%. As a result, the treatments involving legumes contributed to normalizing the organic matter content of the soil. The simultaneous association of these two legumes led to a decrease in yam production, contrary to the treatment associating only groundnut.

First Report of a Successful Development of Yam Hybrids(Dioscorea alata L.)from Lyophilized and Long-Term Stored Pollens

Various biological constraints including erratic and asynchronous flowering between male and female plants hinder successful hybrid development and genetic gains in greater yam breeding programs.Therefore,pollen storage has gained much attention to facilitate artificial pollinations and increase the genetic gains.This 4-year study aimed at developing a practical long-term pollen storage technique for the successful development of yam hybrids.Fresh pollens were collected from two Dioscorea alata males,then lyophilized(two lyophilization treatments were applied),followed by storage at room temperature(24℃–25℃)for 12 months.Moreover,the lyophilized and stored pollens were tested for viability by crossing with four female varieties.Our results showed that lyophilization is effective for achieving viable pollens after 12 months of storage.Treatment 1(48 h drying)showed higher pollen germination and fertility rates than Treatment 2(72 h drying).Although we observed a reduction in viability of lyophilized pollens after 12 months of storage,we generated hybrid seedlings with success rates from 12%to 21%compared to 21%–31%when using fresh pollens.Paternity testing based on molecular genotyping confirmed the hybrid status of the obtained seedlings,which grew well in a greenhouse.Lyophilization is a practical approach for a long-term storage of greater yam pollen samples.This protocol will positively impact yam breeding programs particularly in developing countries.

一种新的QoS约束的多播路由协议

网络技术和多媒体技术的发展使得未来的Internet对具有QoS(QualityofService)需求的多播应用的支持变得更加迫切 .为了解决现有QoS多播路由协议消息复杂度高、寻路成功率低以及连接建立时间比较长等问题 ,作者提出了一种新的QoS多播约束路由协议MRPQoS(MulticastRoutingProtocolwithQoSconstraints) .它完全分布式运行 ,将局部搜索与全局搜索、单分支搜索与多分支搜索有机地结合在一起 ,较好地解决了上述问题 .仿真结果证明 :MR PQoS较其它协议更适合于网络状态变化比较频繁的环境以及实时多媒体应用 .

铁棍山药水溶性粗多糖提取工艺的研究

研究确立了山药多糖微波辅助水浴法提取工艺与提取率的数学模型。在单因素试验的基础上,通过响应曲面法研究分析了微波功率、微波时间、料液比对山药多糖提取率的影响,并建立了微波辅助水浴法提取山药多糖的最佳工艺∶料液比1∶25、微波时间93 s、微波功率500 W、水浴温度80℃、水浴时间2.5 h;在此条件下山药多糖的提取率达到10.56%。

新型有机螯合捕收剂YAM2的选矿特性研究

通过一系列浮选数据介绍了由云南大学矿产研究所最新开发的代号为YAM2的n-辛基-异羟肟酸钾有机螯合捕收剂在浮选复杂难选氧化铜矿的显著优势和此药剂与常规捕收剂组合使用时的协同增效作用。对人工硅孔雀石富矿试样的试验结果表明，当调整矿浆的pH值为7．5～10．5时，YAM2是硅孔雀石矿物的有效捕收剂。对实际难选氧化铜矿的试验结果表明，YAM2可单独使用，也可与其他硫化矿捕收剂组合使用，当YAM2与常规硫化矿捕收剂组合使用时，明显加强了其协同增效作用，在精矿品位略有提高的基础上，精矿回收率提高了15—20个百分点。

麻沙山药1号特征特性及其栽培技术

介绍山药新品种麻沙山药1号的特征特性,从播种育苗、移栽定植、田间管理、病虫害防治、采收贮藏等方面总结其关键栽培技术。

Synthesis of carbon nanofibers@MnO_2 3D structures over copper foil as binder free anodes for lithiumion batteries

A 3D structured composite of carbon nanofibers @ MnO2 on copper foil is reported here as a binder free anode of lithium ion batteries, with high capacity, fast charge/discharge rate and good stability. Carbon nanofiber yarns were synthesized directly over copper foil through a floating catalyst method. The growth of carbon nanofiber yarns was significantly enhanced by mechanical polishing of the copper foils, which can be attributed to the increased surface roughness and surface area of the copper foils. MnO2 was then grown over carbon nanofibers through spontaneous reduction of potassium permanganate by the carbon nanofibers. The obtained composites of carbon nanofibers@MnO2 over copper foil were tested as an anode in lithium ion batteries and they show superior electrochemical performance. The initial reversible capacity of carbon nanofibers@MnO2 reaches up to around 998 mAh.g-1 at a rate of 60 mmA.g-l based on the mass of carbon nanofibers and MnO2. The carbon nanofibers @ MnO2 electrodes could deliver a capacity of 630 mAh.g-1 at the beginning and maintain a capacity of 440 mmAh.g-1 after 105 cycles at a rate of 600 mA.g-~. The high initial capacity can be attributed to the presence of porous carbon nanofiber yarns which have good electrical conductivity and the MnO2 thin film which makes the entire materials electrochemically active. The high cyclic stability of carbon nanofibers@MnO2 can be ascribed to the MnO2 thin film which can accommodate the volume expansion and shrinking during charge and discharge and the good contact of carbon nanofibers with MnO2 and copper foil.

ZrB_2复合材料表面YAM涂层制备

以硝酸铝和硝酸钇摩尔配比混合溶液为前躯体,采用共沉淀法及随后热处理在ZrB_2复合材料表面制备YAM涂层。研究了基体材料表面处理状态、浸涂次数和煅烧温度对涂层结构的影响。借助X射线衍射仪和扫面电镜分析了涂层热处理后的物相、形貌和涂层与基体之间的结合情况。研究结构表明:经过1750℃真空煅烧,基体表面形成YAM涂层,涂层厚度随浸涂次数增加而增加,浸涂两次的涂层表面光滑程度最好,而经过粗化能够提高涂层与基体间良好结合。

Structures and Properties of Composite Yarns of Filaments and Wool Staple Fibers

More and more composite yarns of filament and wool staple fiber have been applied to develop the new type of fabrics. However, the great difference in yarn structures between the composite yarns and conventional staple yarns does affect the properties of yarns and fabrics. In this paper, it has been studied that the differences of the composite yarn properties of tensile, bending rigidity, torsional rigidity, the hairiness and irregularity etc.

一种基于Yarn云计算平台与NMF的大数据聚类算法

为了改进Map Reduce早期版本在大数据聚类算法方面的性能,文章提出了基于Yarn(Yet Another Resource Negotiator)云计算平台与非负矩阵分解NMF(Nonnegative Matrix Factorization)的大数据聚类方法。文章讨论了高维数据相似性聚类与非负矩阵分解的结合及其面向Map Reduce的数据聚类的任务划分方式。该方法的实现采用Hadoop2.0的Yarn平台,利用Hadoop的HDFS(Hadoop Distributed File System)来存储大容量的外部数据;描述了基于NMF的大数据相似性聚类方法的编码与实现过程,并以电信运营商的大数据作为案例程序进行了测试。实验结果表明,Yarn云平台比传统用于数据聚类的非负矩阵方法具有更好的运行时间与加速比,能够在可以接受的时间范围内完成电信运营商的大数据处理。

Comprehensive characterization of yam tuber nutrition and medicinal quality of Dioscorea opposita and D.alata from different geographic groups in China

China is an important domestication center of yams,and two main yam species of Dioscorea opposita and D.alata are commonly cultivated in China.However,the differences of nutritional and medicinal characteristics between the two species and their subgroups remain unclear,which would greatly affect the resource conservation and commercial utilization of yams.In this study,typical yam resources including the species of D.opposita(wild and cultivated Ruichang yam from southern China,and Tiegun yam from northern China)and two landraces of D.alata(Longyan yam and Anyuan yam from southern China)were selected as materials.Nutritional traits and medicinal characteristics were determined and analyzed respectively.The results showed that there was no significant differences in the content of most nutrients between D.opposita and D.alata,but most cultivated Ruichang yam of D.opposita showed higher levels of starch,soluble sugar,sucrose,and ascorbate in tuber than that in yam from D.alata.Moreover,an UPLC-MS method was developed for identification and determination of medicinal characteristics in the two species.The results showed that allantoin can be detected in all selected samples.Cultivated Ruichang yam of D.opposita possessed the highest allantoin content among the tested materials,and was significantly different with that in Tiegun yam and D.alata.Dioscin was not detected in D.alata.Overall,there was little difference in nutritional composition between D.opposita and D.alata,but the medicinal quality of D.opposita was better than that of D.alata.Due to the outstanding comprehensive quality,the local variety of cultivated Ruichang yam can be further developed and utilized.

Fiber Migration and Distribution of Twist at Different Radial Positions of Rotor Yarn-by Hi-Scope Video Microscope System

This paper describes systematic measurement of fiber migration and distribution pattern of twist at different radial positions of rotor spun yarn mixed tracer fiber by Hi-Scope Video Microscope System. The positions of tracer fibers were measured in three dimensions accurately, and the migration index and the twist distribution at different radial positions of rotor yarn were calculated and analyzed. This research result serves to provide useful references for further study on the structural mechanics of rotor spun yarn.

Isolation of Nine Microorganisms from Rotten <i>Dioscorea rotundata</i>(White Yam) and Antimicrobial Sensitivity Test with Five Plant Extracts

Five yam tuber varieties were investigated for microorganisms that cause yam tuber rot from five local government areas of Benue State, Nigeria, between the months of March 2014 to March 2015. Five fungi species: Aspergillus niger, Rhizopus stolonifera, Botryodiplodia theobromae, Fusarium oxysporum, Penicillium marnessei and four bacteria species: Serratia marcescens, Erwinia caro-tovora, Klebsiella oxytoca and Pseudomonas aeruginosa were consistently isolated. Pathogenicity test carried out confirmed these organisms as the pathological agent of the rot. Antimicrobial activity of five plant aqueous extracts: Terminalia catapa (common name fruit), Passiflora edulis (passion fruit), Daniella oliveri (Chiha-Tiv), Ceiba pentandra (Vambe-Tiv), Jatropha tanjorensis (Catholic plant) was carried out on the isolated microorganims and they showed varing degrees of inhibition, the aqueous extract from Passiflora edulis, Ceiba pentandra and Jatropha tanjorensis were able to inhibit all the fungi completely.

In vitro modulation of TH1 and TH2 cytokine expression by edible tuber of Dioscorea alata and study of correlation patterns of the cytokine expression

The underground tuber of Dioscorea alata is a palatable food and is also claimed to have therapeutic effects.Various groups of researchers demonstrated different activities of this tuber such as antioxidant,hepatoprotective,anti-ulcer and anti-diabetic activities.Therefore,the aim of the present study was to evaluate the immunomodulatory potentialities of 70%hydro-methanolic extract of D.alata underground tubers by investigating different parameters like the expression of interferon gamma(IFN-),interleukin(IL)-2,IL-4 and IL-10,in addition to its effect on the proliferation of murine splenic T-lymphocytes in vitro.Results demonstrated that D.alata can actively polarize the TH0 lymphocyte population towards the expression of TH1 immune response by up-regulating the IFN-and IL-2 expression and down-regulating the IL-4 and IL-10 expression.The tuber extract also proved to possess mitogenic activity as evidenced by the proliferation of lymphocytes in vitro.©2014 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Effect of Incorporation of Yam Flour and Moringa Powder in Wheat Bread on Glycemic Response

This study aimed to investigate the effect of yam flour substitution (Dioscorea alata L.) and moringa powder in wheat bread on glycemic response. Glycemic index (GI) and glycemic load (GL) of pieces of bread were determined. A mixture plan design was used to determine the optimal formulation of bread made of yam flour, wheat flour and moringa powder. The mixture of 79.4% soft wheat flour, 20% yam flour and 0.6% moringa leaves powder has a good potential in bread preparation and was used in this study. 100% wheat bread was used as control. Postprandial blood glucose response (glycemic response) was evaluated with the glucose used as a reference food. Blood glucose responses were measured at different intervals for 2 hours. The results indicated that composite bread had low GI and GL values than wheat bread. Values are GI = 80 and GL = 61.2 for wheat bread and GI = 37.78 and GL = 29.65 for the composite bread. This study demonstrated that the inclusion of yam flour of moringa leaves powder in bread production might not pose a threat to blood glucose response compared to wheat bread. These pieces of bread could be included easily in diabetics’ and non-diabetics diet.

DPPH Radical Scavenging Capacity of Phenolic Extracts from African Yam Bean (<i>Sphenostylis stenocarpa</i>)

The phenolic extracts of the seeds of African yam bean (Sphenostylis stenocarpa) were studied using different extraction solvents (70% ethanol, 80% acetone and acidic 70% acetone) and two heat treatment methods (dry heating on a hot plate with acid-washed sea sand at 135℃ for 25 min and wet heating in an autoclave at 120℃ for 20 min). The study examined the total phenolic content (TPC), total flavonoid content (TFC), and condensed tannin content (CTC) of the seed extracts, as well as their free radical scavenging and antioxidant properties. The raw African yam bean seed was dry heated in air oven at 100℃ for 5 min (control). Heat treatments application affected the phenolic contents of the seeds significantly (p < 0.05). The free radical scavenging activity of the phenolics were done using 2,2-diphenyl- 1-picrylhydrazyl (DPPH). The effectiveness of the extract was determined using DPPH at 50 mg/g, 10 mg/g and 5 mg/g of the extracts. At 5 mg/g, the extract was most effective indicating that higher concentration of extract gave higher antioxidant activity. The seed has high antioxidant capacity and an appreciable amount of phenolic extracts.