Endogenous resistance to insect pests in alfalfa: engineering for enhanced resistance

Alfalfa (Medicago sativa) is a valuable forage crop grown throughout the World. While the crop is resistant to attack by many insect pests, it is subject to potentially severe losses through the action of several specific pests, which are adapted to alfalfa as a host. The most economically damaging of these pests is the alfalfa weevil, Hypera postica. This thesis investigates the endogenous defences of alfalfa against insects, which are responsible for its resistance to non-pest species, and develops a strategy for increasing the resistance of alfalfa towards pest species, specifically alfalfa weevil. The role of saponins in the resistance of alfalfa towards non-pest species has been investigated by using successive insect bioassays, carried out with extracts, mixtures of compounds, and purified compounds, to identify which compounds present in alfalfa tissues are responsible for toxicity towards insects. Crude saponin extracts, in 80% methanol, from alfalfa seedling tissues were bioassayed against the cowpea seed weevil, Callosobruchus maculatus. Both extracts from shoot and root tissues caused larval mortality and delayed development when incorporated into an artificial diet at levels comparable to those found in alfalfa, but lower levels of root saponin extracts showed probiotic effects, whereas lower levels of shoot saponins were still toxic. Hydrolysis of the saponins present in these extracts decreased their toxicity. Purified saponin mixtures were prepared by butanol partition and ether precipitation, and were bioassayed against potato aphid (Aulacorthum solani) in a liquid artificial diet, which allowed quantitative effects to be accurately assayed. Shoot saponins showed a concentration-dependent toxic effect, decreasing survival over an initial 5 day period, decreasing growth, and inhibiting fecundity (measured by nymph production) in these insects. Alfalfa root saponins showed no deleterious effects below a threshold level, but caused complete mortality above this level. The alfalfa saponin mixtures were separated into fractions by chromatography on a reverse phase column. Bioassays showed that the toxicity towards potato was associated only with fractions containing saponins, and that fractions containing a component identified as soyasaponin I were more toxic to the aphids than others. Finally, two saponins purified from alfalfa, soyasaponin I and medicoside A, were assayed. These assays showed that soyasaponin was consistently more toxic in effects on mortality, growth and fecundity. It was concluded that alfalfa saponins, and in particular soyasaponin I, were major factors in the resistance of alfalfa towards potato aphid, and other insects. A saponin mixture from another species, sugar beet {Beta vulgaris) was also toxic to aphids, supporting the view that saponins have a general role in resistance to insects. Inhibition of insect digestive proteolysis by expression of a foreign protein protease inhibitor was selected as a strategy to protect transgenic alfalfa against alfalfa weevil. The major protease activity in larvae of this msect was shown to be due to cysteine proteases, which could be inhibited by cystatins. Rice cystatin was produced in large quantity using a recombinant protein expression system in E. coli for use in a "proving" experiment. Incorporation of the rice cystatin into an alfalfa weevil larvae artificial diet decreased survival, showing that this approach was feasible

The Determinants Of Medical Tourists’ Satisfaction In Iran

Medical tourism industry has considerably progressed in Iran over the past few years. The present study has aimed to investigate Iran’s significant factors through medical tourists’ satisfaction. Since medical tourists’ positive perception will lead to a greater number of health tourists, superior global ranking and eventually more development of this industry

The effects of different grain sources on gut evacuation rate and nutrient digestibility in common carp, Cyprinus carpio

The main objective of this study was to investigate whether dietary cereal grains of different carbohydrate sources can change nutrient digestibility, evacuation rate and the number of bacterial colony in gut. Common carp with an average weight of 244.7±6.3 g were divided randomly into sixteen 500-L tanks with a stocking density of 18 fish per tank. Four experimental diets were formulated by inclusion of four cereal grains (wheat meal, barley meal, corn meal and rice meal) in a basal diet in a ratio of 40%. The four experimental treatments with four replicates were assigned in 16 tanks. Inclusion of different types of cereal grain affected growth related parameters in C. carpio. Corn and wheat diets led to larger weight gains and better feed conversion ratios compared to barley diet (324 and 321 versus 305 g for final weight; 1.93 and 1.90 versus 2.25 for fed conversion ratio). Protein and dry matter digestibility in the common carp fed rice diet were lower in comparison to other cereal grains (73 and 58 versus 79-82 and 67-70%). The maximum and minimum bacterial colony numbers (133 and 63 cfu.gr-1×10-7) were observed in fish fed wheat and corn diets, respectively. Evacuation time showed a delay by feeding on barley diet and almost all dry matter left in part I of the intestine after 30 min (first sampling), but this rate was recorded 70% for corn diet .In conclusion, although dietary grains change evacuation time and bacterial colonial number in common carp, this condition does not have a great impact on nutrient digestibility

Mechanical Properties of A356 Matrix Composites Reinforced with Nano-SiC Particles

Metal matrix composites form one group of the new engineered materials in which a strong ceramic reinforcement is incorporated into a metal matrix to improve its properties including specific strength, specific stiffness, wear resistance, excellent corrosion resistance and high elastic modulus. A compocasting method was employed to incorporate SiC nano-particles into the aluminum alloy and fabricate metal matrix nanocomposites with uniform reinforcement distribution. Microstructural characterization of compocast composites show a uniform distribution of nano-particles, grain refinement of aluminum matrix, and presence of the minimal porosity. It was revealed that the presence of nano-SiC reinforcement led to significant improvement in hardness, 0.2% yield strength and UTS while the ductility of the aluminum matrix is retained.Композиты с металлической матрицей образуют группу новых искусственно спроектированных материалов, в металлическую матрицу которых вводятся керамические упрочняющие компоненты с целью улучшения ее механических свойств, включая удельную прочность и удельную жесткость, а также износостойкость, и обеспечения высокой коррозионной устойчивости и высокого модуля упругости. Метод композиционного литья использовался для введения наночастиц SiC в алюминиевый сплав и изготовления нанокомпозитов с металлической матрицей и однородным распределением упрочняющих компонентов. Микроструктурный анализ композитов, полученных методом композиционного литья, показал однородное распределение наночастиц, уменьшение размеров зерен матрицы из алюминиевого сплава и минимальную пористость материала. Установлено, что наличие наночастиц карбида кремния существенно повышает твердость, условный предел текучести и предел прочности при сохранении исходной пластичности алюминиевой матрицы.Композити з металічною матрицею утворюють групу нових штучно спроектованих матеріалів, у металічну матрицю яких вводяться керамічні зміцнювальні компоненти з метою покращання її механічних властивостей, включаючи питомі міцність і жорсткість, а також зносостійкість, та забезпечення високої корозійної стійкості і високого модуля пружності. Метод композиційного лиття використовувався для введення наночастинок SiC у алюмінієвий сплав та виготовлення нанокомпозитів із металічною матрицею й однорідним розподілом зміцнюваних компонентів. Мікроструктурний аналіз композит ів, що отримані методом композиційною лиття, показав однорідний розподіл наночастинок, зменшення розмірів зерен матриці з алюмінієвого сплаву та мінімальну пористість матеріалу. Установлено, що наявність наночастинок карбіду кремнію суттєво підвищує твердість, умовну границю текучості і границю міцності при збереженні початкової пластичності алюмінієвої матриці

Resistance mechanisms and protein expression of screening genotypes of alfalfa field germplasm to alfalfa weevil (Hypera postica Gyll) (Col ., Curculionidae)

The alfalfa weevil (Hypera postica Gyll) is a serious pest that adversely affects alfalfa forage yield and completely destroys the harvest in the early season every year. In this study, we evaluated the mechanisms of antixenosis, antibiosis and tolerance of 16 genotypes obtained from the screening field, between 18 and 27 °C in April and May 2014 in a completely randomized design with four replications at the greenhouse condition. The rate of expressed proteins and their differences within genotypes were analyzed using SDS-PAGE method. The trichome density and leaf chlorophyll content and their impact on the quantity of weevil larvae were evaluated. We used Mantel test to determine the correlation between greenhouse features and data from one-dimensional SDS-PAGE electrophoresis. No significant correlation was observed between the traits in the greenhouse and molecular data. Using ward method, the studied genotypes were divided into three groups: resistant, moderately susceptible and susceptible. The genotypes "Mahali-Bami", "Talents 2"," Hamadani 106" and "code 108" can be further investigated in the future for their potential resistance to alfalfa weevil larvae

Higher Mediterranean diet score is associated with longer time between relapses in Australian females with multiple sclerosis

A higher Mediterranean diet score has been associated with lower likelihood of multiple sclerosis. However, evidence regarding its association with disease activity and progression is limited. Using data from the AusLong Study, we tested longitudinal associations (over 10 years follow-up) between the alternate Mediterranean diet score (aMED) and aMED-Red (including moderate consumption of unprocessed red meat) and time between relapses and disability measured by Expanded Disability Status Scale (EDSS) (n=132; 27 males, 105 females). We used covariate-adjusted survival analysis for time between relapses, and time series mixed-effects negative binomial regression for EDSS. After adjusting for covariates, both higher aMED (aHR=0.94, 95%CI: 0.90, 0.99, p=0.009) and higher aMED-Red (aHR=0.93, 95%CI: 0.89, 0.97, p=0.001) were associated with significantly longer time between relapses in females. Whether specific dietary components of a Mediterranean diet are important in relation to relapses merits further study.Comment: Original article, Brief communication, 13 pages, 2 tables (one main table and one supplementary table

Data-mining modeling for the prediction of wear on forming-taps in the threading of steel components

An experimental approach is presented for the measurement of wear that is common in the threading of cold-forged steel. In this work, the first objective is to measure wear on various types of roll taps manufactured to tapping holes in microalloyed HR45 steel. Different geometries and levels of wear are tested and measured. Taking their geometry as the critical factor, the types of forming tap with the least wear and the best performance are identified. Abrasive wear was observed on the forming lobes. A higher number of lobes in the chamber zone and around the nominal diameter meant a more uniform load distribution and a more gradual forming process. A second objective is to identify the most accurate data-mining technique for the prediction of form-tap wear. Different data-mining techniques are tested to select the most accurate one: from standard versions such as Multilayer Perceptrons, Support Vector Machines and Regression Trees to the most recent ones such as Rotation Forest ensembles and Iterated Bagging ensembles. The best results were obtained with ensembles of Rotation Forest with unpruned Regression Trees as base regressors that reduced the RMS error of the best-tested baseline technique for the lower length output by 33%, and Additive Regression with unpruned M5P as base regressors that reduced the RMS errors of the linear fit for the upper and total lengths by 25% and 39%, respectively. However, the lower length was statistically more difficult to model in Additive Regression than in Rotation Forest. Rotation Forest with unpruned Regression Trees as base regressors therefore appeared to be the most suitable regressor for the modeling of this industrial problem.ThisinvestigationwaspartiallysupportedbyProjects TIN2011-24046,IPT-2011-1265-020000andDPI2009- 06124-E/DPIoftheSpanishMinistryofEconomyand Competitiveness.WethanktheUFIinMechanicalEngineer- ing oftheUPV/EHU(UFIMECA-1.0.2016(ext))forits support

Development of high-performance aluminium 6061/SiC nanocomposites by ultrasonic aided rheo-squeeze casting method

In the modern era, the need for new products with novel processing and multipurpose materials is increased. The current market requirements for engineering applications are lightweight, high strength and low-cost materials. This paper explores the novel development process of high-performance nano cermet material for aerospace applications. Herein, lightweight aluminium 6061 + 2% of SiC (40 nm) nano cermet was fabricated through the casting method. The effects of ultrasonication, double stir casting or rheocasting, and squeezing pressure on nano cermet fabrication were successfully investigated by comparing their physical, thermal and mechanical properties. Scanning electron microscopy was employed to analyse the morphology of the cermets, and the presence of reinforcements was verified through EDS. The reinforcement of SiC into Al 6061 improved density, hardness, and reduction in porosity and grain refinement. This study reveals a novel fabrication process of ultrasonic-aided rheo-squeeze casting technique which enhanced the mechanical properties of the cermets compared to Al 6061 alloy due to nanoparticles homogeneous distribution, nominal agglomeration and porosity

Vitamin D and omega-3 fatty acid supplements in children with autism spectrum disorder: a study protocol for a factorial randomised, double-blind, placebo-controlled trial

Background: There is strong mechanistic evidence to suggest that vitamin D and omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFAs), specifically docosahexaenoic acid (DHA), have the potential to significantly improve the symptoms of autism spectrum disorder (ASD). However, there are no trials that have measured the effect of both vitamin D and n-3 LCPUFA supplementation on autism severity symptoms. The objective of this 2 × 2 factorial trial is to investigate the effect of vitamin D, n-3 LCPUFAs or a combination of both on core symptoms of ASD. Methods/design Children with ASD living in New Zealand (n = 168 children) will be randomised to one of four treatments daily: vitamin D (2000 IU), n-3 LCPUFAs (722 mg DHA), vitamin D (2000 IU) + n-3 LCPUFAs (722 mg DHA) or placebo for 12 months. All researchers, participants and their caregivers will be blinded until the data analysis is completed, and randomisation of the active/placebo capsules and allocation will be fully concealed from all mentioned parties. The primary outcome measures are the change in social-communicative functioning, sensory processing issues and problem behaviours between baseline and 12 months. A secondary outcome measure is the effect on gastrointestinal symptoms. Baseline data will be used to assess and correct basic nutritional deficiencies prior to treatment allocation. For safety measures, serum 25-hydroxyvitamin D 25(OH)D and calcium will be monitored at baseline, 6 and 12 months, and weekly compliance and gastrointestinal symptom diaries will be completed by caregivers throughout the study period. Discussion To our knowledge there are no randomised controlled trials assessing the effects of both vitamin D and DHA supplementation on core symptoms of ASD. If it is shown that either vitamin D, DHA or both are effective, the trial would reveal a non-invasive approach to managing ASD symptoms. Trial registration Australian New Zealand Clinical Trial Registry, ACTRN12615000144516. Registered on 16 February 2015. Electronic supplementary material The online version of this article (doi:10.1186/s13063-016-1428-8) contains supplementary material, which is available to authorized users

Vitamin D Receptor Gene Polymorphisms Modify Cardiometabolic Response to Vitamin D Supplementation in T2DM Patients

There is conflicting evidence on the favorable effects of vitamin D supplementation on metabolic profile in Type 2 diabetes mellitus (T2DM) patients and this might be due to genetic variations in vitamin D receptors (VDRs). Thus, we studied the metabolic effects of a 12-month vitamin D supplementation in T2DM patients according to VDR polymorphisms. A total of 204 T2DM subjects received 2000 IU vitamin D3 daily for 12 months. Serum 25(OH)D and metabolic profiles were measured at baseline and after 12 months. VDR polymorphisms (Taq-I, Bsm-I, Apa-I and Fok-I) were identified using TaqMan genotyping assays. Vitamin D supplementation significantly increased HOMA β-cell function (p = 0.003) as well as significantly decreased triglycerides, total and LDL-cholesterol (p < 0.001). The lowest increment in 25(OH)D levels was detected in patients with Fok-I CC genotypes (p < 0.0001). With vitamin D supplementation, Taq-I GG genotype carriers showed significant improvements in triglycerides, LDL- and total cholesterol, insulin, HbA1c and HOMA-IR (p < 0.005, 0.01, < 0.001, < 0.005, 0.03 and 0.01, respectively). Similarly, Bsm-I TT genotype carriers showed significant improvements in triglycerides (p = 0.01), insulin and HOMA-IR (p-values < 0.05). In conclusion, improvements in metabolic profile due to vitamin D supplementation is influenced by VDR polymorphisms, specifically for carriers of Taq-I GG and Bsm-I TT genotypes