利用AhMITE1转座子分子标记鉴定花生F_1代杂种

对杂交后代进行杂种的真实性鉴定是杂交育种成功的前提。AhMITE1转座子标记是一类基于PCR的分子标记,其在花生中扩增的产物片段差异大,多态性强,采用琼脂糖凝胶电泳即可区分。本研究用7对多态性转座子引物对6个花生组合的166个F1单株进行了真实性鉴定。根据杂种植株含有父母本带型为依据共鉴定出了77个单株为真杂种,真杂种植株数占植株总数的比率为44.86%;收获时根据田间表型鉴定出了79个单株为真杂种,真杂种比率为47.59%。

利用荧光标记SSR技术鉴定花生F1代杂交种

杂种真实性的鉴定对花生杂交育种和遗传群体构建是非常重要的。利用IRD荧光标记SSR对亲本D145和D089及其F1单株进行分析。结果表明,在可扩增的41对引物中,6对在两亲本中表现多态性,多态性引物比率为14.6%。7个F1单株中,3株表现杂合带型,为真杂种,4株为假杂种,表现母本带型或新带型。根据F2:3家系的网斑病抗性分离表现和农艺性状可知,表现杂合带型的为真杂种,表现母本带型或新带型的为假杂种,与SSR标记鉴定的结果一致。证明应用荧光标记SSR技术鉴定真假杂种是切实可行的。

花生微卫星DNA分离方法的研究

比较了2种从AFLP扩增片段中分离花生微卫星DNA(SSR)的方法,结果表明,从预扩增的AFLP片段中富集SSR的方法简便,获得较多的含简单重复序列的片段;而从选择性扩增的AFLP片段中分离SSR后直接从电泳胶上切取差异片段进行测序的方法效率低,不适用于分离花生的微卫星DNA。

农杆菌介导的花生遗传转化条件优化

为建立花生快速高效的遗传转化体系,以浸泡吸水后的花生半粒种子为转化受体,利用根癌农杆菌介导法,以除草剂Basta抗性筛选及基因组DNA的bar基因PCR检测为指标,优化花生遗传转化体系。研究结果表明,在侵染悬浮液中加入1mmol/L二硫苏糖醇(DTT)提高了农杆菌介导的转化效率(最高提升36.5%);与YEB培养液相比,AB重悬液的使用显著提高了农杆菌的转化效率(最高提升19.3%);农杆菌菌液OD_(600)为0.7时转化效率最高;基因型显著影响转化效率,EXP27-1516的转化效率为69.03%,显著高于14AU01(56.67%);以花生半粒种子为转化受体,从种子培养到形成茁壮根系仅需8周,明显短于子叶节转化所需的13周。优化后的农杆菌介导的花生遗传转化体系为花生转基因研究提供了重要的研究工具。

Microsatellite Enrichment from AFLP Fragments by Magnetic Beads

A simple and efficient method was presented for isolating microsatellite DNA markers from peanut (Arachis hypogaea L.) genome. The genomic DNA was converted into pre-amplified AFLP fragments and hybridized with biotin-labeled SSR probes. Then the hybrid mixture was used to incubate with magnetic beads coated with streptavidin. After washing to remove the non-SSR fragments, the eluted single-strand DNA, which was cloned and sequenced, was largely enriched for microsatellites. Primers can then be designed according to the sequence flanking the repeat motifs and used for polymorphism analysis. The whole experiment can be completed within one week and can be employed as a reliable option for any molecular laboratory to develop SSR markers.

Research on Time Synchronization Method Under Arbitrary Network Delay in Wireless Sensor Networks

To cope with the arbitrariness of the network delays,a novel method,referred to as the composite particle filter approach based on variational Bayesian(VB-CPF),is proposed herein to estimate the clock skew and clock offset in wireless sensor networks.VB-CPF is an improvement of the Gaussian mixture kalman particle filter(GMKPF)algorithm.In GMKPF,Expectation-Maximization(EM)algorithm needs to determine the number of mixture components in advance,and it is easy to generate overfitting and underfitting.Variational Bayesian EM(VB-EM)algorithm is introduced in this paper to determine the number of mixture components adaptively according to the observations.Moreover,to solve the problem of data packet loss caused by unreliable links,we propose a robust time synchronization(RTS)method in this paper.RTS establishes an autoregressive model for clock skew,and calculates the clock parameters based on the established autoregressive model in case of packet loss.The final simulation results illustrate that VB-CPF yields much more accurate results relative to GMKPF when the network delays are modeled in terms of an asymmetric Gaussian distribution.Moreover,RTS shows good robustness to the continuous and random dropout of time messages.

The effects of tannins-containing ground pine bark diet upon nutrient digestion,nitrogen balance,and mineral retention in meat goats

Background： Pine bark is a rich source of phytochemical compounds including tannins, phenolic acids, anthocyanins, and fatty acids. These phytochemicals have potential to significantly impact on animal health and animal production. The goal of this work is to measure the effects of tannins in ground pine bark as a partial feed replacement on feed intake, dietary apparent digestibility, nitrogen balance, and mineral retention in meat goats. Results： Eighteen Kiko cross goats （initial BW = 31.8 ± 1.49 kg） were randomly assigned to three treatment groups （n = 6）. Dietary treatments were tested： control （0 % pine bark powder （PB） and 30 % wheat straw （WS））; ] 5 % PB and 15 % WS, and 30 % PB and 0 % WS. Although dry matter （DM） intake and digestibility were not affected （P〉 0.10） by feeding PB, neutral detergent fiber （linear; P= 0.01）, acid detergent fiber （linear; P= 0.001） and lignin digestibility （linear; P= 0.01） decreased, and crude protein （CP） digestibility tended to decrease （P=0.09） as PB increased in the diet, apparent retention of Ca （P= 0.09）, P （P=0.03）, Mg （P= 0.01）, Mn （P= 0.01）, Zn （P= 0.01） and Fe （P= 0.09） also increased linearly. Nitrogen intake and fecal N excretion were not affected （P〉 0.05） by addition of PB in the diet, but N balance in the body was quadratically increased （P〈 0.01） in the 15 % PB diet compared to other diets. This may be due to more rumen escape protein and less excreted N in the urine with the 15 % PB diet. The study showed that a moderate level of tannin-containing pine bark supplementation could improve gastrointestinal nitrogen balance with the aim of improving animal performance. Conclusion： These results suggest that tannin-containing PB has negative impact on fiber, lignin, and protein digestibility, but positively impacted on N-balance.

Prediction of Feed Intake and Its Relationships with Chemical Composition of Diets in Goats Consuming Concentrate, Bahiagrass Pasture and Mimosa Browse

An indoor and a grazing experiment was conducted to determine how estimated feed intake and digestion by grazing goats consuming concentrate, bahaigrass pasture, and mimosa browse changed with body weight (BW), level of supplementation, and forage chemical composition. Twenty four Boer wether goats were assigned in a completely randomized design with repeated measures on the following 3 treatments: concentrate, mimosa browse, and bahiagrass pasture. Internal markers used to estimate both dry matter (DM) digestibility (DMD) and DM intake (DMI) included acid detergent lignin (ADL) and acid insoluble ash (AIA). Marker-derived estimates of DMD and DMI were compared with DMD measured by total fecal collection or directly measured by in vivo feed intake rate. Both ADL and AIA-based markers in mimosa and bahiagrass diets were similar from those derived by in vivo DMD;however, AIA-based marker in concentrate was under-estimated (P in vivo DMD in mimosa and bahiagrass, although AIA concentration in mimosa seemed to be low compared to others. All markers yielded feed intake estimates that differed from those derived by ADL (P in vivo control, with ADL (P in vivo intake methods for digestibility studies. Both ADL and AIA occur in common forages at readily measurable levels and laboratory procedures are not difficult or time consuming. Therefore, both ADL and AIA have possible use in digestibility studies where other methods may not be applicable.

Noise Removal in Speech Processing Using Spectral Subtraction

Spectral subtraction is used in this research as a method to remove noise from noisy speech signals in the frequency domain. This method consists of computing the spectrum of the noisy speech using the Fast Fourier Transform (FFT) and subtracting the average magnitude of the noise spectrum from the noisy speech spectrum. We applied spectral subtraction to the speech signal “Real graph”. A digital audio recorder system embedded in a personal computer was used to sample the speech signal “Real graph” to which we digitally added vacuum cleaner noise. The noise removal algorithm was implemented using Matlab software by storing the noisy speech data into Hanning time-widowed half-overlapped data buffers, computing the corresponding spectrums using the FFT, removing the noise from the noisy speech, and reconstructing the speech back into the time domain using the inverse Fast Fourier Transform (IFFT). The performance of the algorithm was evaluated by calculating the Speech to Noise Ratio (SNR). Frame averaging was introduced as an optional technique that could improve the SNR. Seventeen different configurations with various lengths of the Hanning time windows, various degrees of data buffers overlapping, and various numbers of frames to be averaged were investigated in view of improving the SNR. Results showed that using one-fourth overlapped data buffers with 128 points Hanning windows and no frames averaging leads to the best performance in removing noise from the noisy speech.

Some Sharpening and Generalizations of a Result of T. J. Rivlin

Let p（z） = a0＋a1z＋a2z^2＋a3z3＋…＋anz^n be a polynomial of degree n. Rivlin [12] proved that if p （z） ≠ 0 in the unit disk, then for 0 〈 r ≤ 1,max（｜r＋1｜/2）^n max｜p（z）｜.｜z｜=1In this paper, we prove a sharpening and generalization of this result and show by means of examples that for some polynomials our result can significantly improve the bound obtained by the Rivlin＇s Theorem.

Effect of Environmental Conditions on Tin (Sn) Whisker Growth

This research focuses on tin whisker growth under two different environmental conditions namely hygrothermal and a salt solution. Tin coated brass coupons were used for this study to analyze the growth of tin whiskers over time. Their growth rates were examined periodically using optical and scanning electron microscopy. The physical characteristics of the tin whiskers were identified for each environmental condition. It was discovered that submersion of tin coated brass substrates in 5% salt solution considerably increased the density (number of whiskers per unit area), and the length of the whiskers. In addition, it was found that the geometry and aspect ratio of tin whiskers were different for each environment.

Effects of Plant Tannin Extracts Supplementation on Animal Performance and Gastrointestinal Parasites Infestation in Steers Grazing Winter Wheat

Twenty-six stocker cattle (286.1 ± 25.7 kg) were used to quantify the effect of commercial plant tannin extracts (control vs. mimosa and chestnut tannins) on animal performance, gastrointestinal parasites control and plasma metabolite changes in heifers grazing winter wheat forage (Triticum aestivum L. var. “cutter”). The forage biomass and crude protein content were generally similar among treatments. Initial live-weight (LW) was similar among treatments, although final LW (P = 0.1) and average daily gain (ADG;P P Ostertagia was lower (P P P < 0.02) for chestnut tannins group than for control, and intermediate for mimosa tannins. However, cholesterol level was similar among treatment after 20 days cessation of tannins treatments. Our data suggest that heifers grazing winter wheat forage supplemented with plant tannins rather than control (non-tannins group) increased ADG (8% to 19%) for mimosa and chestnut tannins groups, respectively with no detectable detrimental effects on animal health. The increase in ADG may be due to decrease fecal parasites infections.

Improvement in Mechanical and Thermo-Mechanical Properties of Epoxy Composite Using Two Different Functionalized Multi-Walled Carbon Nanotubes

In this study, two types of functionalized multi-walled carbon nanotubes were dispersed in an epoxy resin system (SC-15) at room and elevated temperatures using a combination of sonication and high shear mixing methods to determine optimal mechanical and thermal properties. At first, 0.1 wt% - 0.3 wt% of amino-functionalized multi-walled carbon nanotubes (MWCNT-NH2) and carboxyl-functionalized multi-walled carbon nanotubes (MWCNT-COOH) were dispersed in part-A of SC-15 resin using a combination method. The mixture was then added to part-B of epoxy resin and cured using two different cycles (cycle A: at room temperature for 24 hours and post-cure at 93.33?C for 4 hours, cycle B: at 65.56?C for 5 hours). In addition, control samples (without MWCNTs) were also fabricated for baseline consideration under similar conditions. In all cases, epoxy with MWCNTs showed improved performance. Improvements in properties in MWCNT/epoxy samples prepared using cycle A were comparatively lower than samples prepared with cycle B. Flexural and thermo-mechanical results demonstrated maximum improvement in 0.2 wt% MWCNT-COOH modified epoxy samples prepared using cycle B. Improvements in performance for samples cured at elevated temperatures were attributed to better dispersion of MWCNTs due to reduced viscosity. On the other hand, increased number of functional groups present in MWCNT-COOH contributed to higher crosslinking resulting in the highest observed properties.

Effect of Carboxyl Functionalized MWCNTs on the Cure Behavior of Epoxy Resin

Effects of carboxyl functionalized MWCNTs on the cure behavior of epoxy resin (EPIKOTETM resin 862 and EPICURETM curing agent W) were investigated by using differential scanning calorimeter in dynamic scan mode. Results indicated that nanotubes could initiate cure reaction at lower temperature while only 0.1 wt% samples were able to suppress the peak temperature (Tp) consistently regardless of different heating rate due to their higher reaction rate, other two batches (0.2 wt% and 0.3 wt% CNT) showed hardly any change in Tp compared to neat samples. Furthermore, addition of small amount (0.1 wt%) of CNTs significantly reduced the activation energy of the system but further addition elevated that due to their retarding effect. Also, a correlation was established between the dispersion state of CNTs in epoxy and total heat of reaction (ΔH) where lower ΔH was considered as an indication of better interfacial interaction of CNTs with matrix and hence, better dispersion. The difference in curing behavior of three different CNT percentages was discussed in terms of their steric hindrance and state of dispersion in the matrix.

Effect of Preheating Temperature on the Mechanical and Fracture Properties of Welded Pearlitic Rail Steels

The effect of preheating temperature on the mechanical and fracture behavior, hardness, and the microstructure of slot welded pearlitic rail steel were studied. Railhead sections with slots were preheated to 200℃, 300℃, 350℃ and 400℃?before gas metal arc filling to simulate defects repair. Another sample, welded at room temperature (RT) with no preheat, was studied in comparison. The parent rail steel has ultimate strength, yield strength and strain to failure of 1146 MPa, 717 MPa and 9.3%, respectively. Optimum values of these properties for the welded rail steels were found to be 1023 MPa, 655 MPa and 4.7%, respectively, for the 200℃ preheat temperature. On this basis, the optimum weld efficiency was found to be 89.2%. The average apparent fracture toughness KI for the parent rail was 127 MPa.m0.5, while that for the optimum welded joint (200℃ preheat) was 116.5 MPa.m0.5. In addition, the average hardness values of the weld, fusion zone, and heat affected zone (HAZ) were 313.5, 332 and 313.6 HB, respectively, while that for parent rail steel was about 360 HB. Dominance of bainite and acicular ferrite phase in the weld microstructure was observed at 200℃ preheat.

Effect of Zinc Galvanization on the Microstructure and Fracture Behavior of Low and Medium Carbon Structural Steels

Microstructure and fracture behavior of ASTM 572 Grade 65 steels used for wind tower applications have been studied. Steels of two carbon level chemistries designed for this grade were used in the study. Fracture toughness of the steels was studied using 3-point bend test on samples coated with zinc and not coated with zinc. Lower carbon steel showed higher resistance to fracture than medium carbon steel after zinc galvanization. SEM study suggests that zinc and zinc bath additives that migrated to crack tips are responsible for the loss in ductility. The phenomenon of Liquid Metal Embrittlement (LME) is suggested to have taken place. Zinc bath additives traced at crack zones are suggested to have migrated at the zinc galvanizing temperatures.

The Digital Age of Campus Maps on Mobile Devices

Developing mobile applications have always been a rising topic in the technology world. With the recent development in technology, mobile applications play an important role in various applications throughout the world. Mobile applications are constantly evolving. There are several ongoing research and developments in both industry and academia. In this paper, we present the design and implementation of a mobile application that creates an electronic map or e-map application for the campus of Tuskegee University. The goals for this mobile application are to make the campus map easier and user-friendly for parents, visitors, and students using mobile devices. With this mobile application, the users will be able to search and find campus buildings, as well as give feedback on the application to eliminate the need for paper documentation.

Diet-nutrition-related cancer prevention knowledge and beliefs of Sudanese in Khartoum: A descriptive study

Cancer appears to pose a major threat to the health of the Sudanese population. It is the third leading cause of death in the Sudan after malaria and pneumonia, accounting for 5% of all deaths. In 2005, approximately 22,000 people in the Sudan died from cancer and 17,000 of these people were less than 70 years old. This study was designed to: 1) assess nutrition knowledge and selected dietary beliefs related to cancer in Sudanese residing in Khartoum;2) identify perceived barriers to the adoption of eating behaviors consistent with those recommended for cancer prevention;and 3) describe the food preferences and dietary practices in Sudanese residing in Khartoum. An interviewer-administered questionnaire elicited demographic information, cancer-related food and nutrition knowledge, food preferences, selected dietary beliefs, barriers to healthy eating and food practices from 182 participants between the ages of 18 and 35 years. More than 50% of females and males correctly identified the food lowest in fiber from a given list. Respondents were knowledgeable about the fat content of their traditional foods, but unaware of the different types of fat. Only 8.8% of the respondents thought that consumption of fruits and vegetables reduced cancer risk. Resondents perceived nutritionists as the most reliable source of information about nutrition and cancer, and the media as the best source of information on nutrition and healthy cooking. “Samin”, feta cheese, a variety of stews, “Zalabia”, lean meat, brown bread, sesame oil, dried okra, fried fish, and chicken were described as preferred food items by respondents. Daily salt/ sodium intake was described by 44% and 39% of the male and female respondents, respectively, as “high” (>2400 mg/day). The findings of this study have clear implications for aggressive nutrition education intervention programs with emphasis on the traditional foods of the Sudan.

Relative Property (T) for Topological Groups

In this paper, we investigate Kazhdan’s relative Property (T) for pairs , where is a topological group and is any subset of . We show that the pair has Property (FH) and every function conditionally of negative type on is X-bounded if the pair has relative Property (T). We also prove that has Property (T) whenis a s -compact locally compact group generated by its subgroups and the pair has relative Property (T) for all .