Assessment of Sudanese sunflower hybrids for yield, yield components and stability

Development of local sunflower hybrids with superior yields and stable across different environments is the main objective in our breeding program. For this purpose, ten local Sudanese sunflower hybrids designated as SFH32, SFH36, SFH37, SFH310, SFH313, SFH314, SFH341, SFH345, SFH302, and SFH325 were evaluated against Hysun-33 for yield potential and its components at Sennar, Wad Medani, Rahad, New Halfa and Suki. The experiment over all irrigated environments was laid out in RCBD with three replicates during the winter season of 2008. There was considerable variation for yield and its components among hybrids and locations. Genotype-environment interactions through different parameters and the performance of six traits of hybrids were studied. The six traits were plant height (cm), number of seeds per head, percentage of empty seeds,    100-seed weight (g),seed yield (kg ha-1) and oil yield (kg ha-1).Significant differences were observed for hybrids (G), locations (E) and G xE interaction for these six traits. Stability analysis after Eberhart and Russell’s model suggested that the hybrids used in this study were all, more or less, responsive to environmental changes. Most of the hybrids performed better in E4 (New Halfa). Stability analysis identified SFH37 and SFH310 as stable hybrids for plant height, SFH345 and SFH302 were identified as stable for number of seeds per head, whereas, Hysun-33, SFH310 and SFH341 were found stable for low percentage of empty seeds and heavy seed weight, respectively. Three hybrids; SFH310, SFH313 and SFH341 performed better than Hysun-33 and other hybrids across five environments and were considered as most stable hybrids for seed and oil yields. In contrast, hybrids such as SFH32 and SFH37 with regression coefficients greater than one were regarded as sensitive to environmental changes for seed and oil yields. The hybrid SFH310 was identified as stable hybrid for various yield components. The three promising local hybrids were released in June 2009 for commercial production and the local seed production of the hybrid SFH310 (Bohooth-1) was adopted by some seed producers in the country. تطوير هجن محلية من محصول زهرة الشمس ذات إنتاجية عالية وثابته  فى مختلف البيئات ، يعتبر من أهم أهداف برنامج التربية. أجريت هذه التجربة للتقييم عشرة هجن محلية بالرموز SFH32، SFH36 ، SFH37، SFH310، SFH313، SFH314، SFH341، SFH345، SFH3302، و25SFH3 واختبارها مع الشاهد Hysun-33 فى خمسة بيئات مروية هى سنار ، واد مدني، الرهد، حلفا الجديدة، والسوكي لمعرفة مقدرتها الإنتاجية الكامنة. أستخدم تصميم القطاعات العشوائية الكاملة بثلاثة مكررات لتنفيذ التجربة فى كل موقع خلال الموسم الشتوي 2008/2009. أوضحت النتائج وجود فروقات كبيرة فى الإنتاجية و مكوناتها بين الهجن والمواقع. كما أوضح تفاعل الطرز الوراثية مع البيئة ((genotype x environment interactions وجود فروقات معنوية عالية لسته صفات تمت دراستها وهى أطوال النباتات (سنتمترات) وعدد البذور بالقرص والنسبة المئوية للبذور الفارغة ووزن المائة بذرة (جرامات) وإنتاجية البذور(كيلوجرامات/هكتار) وإنتاجية الزيت (كيلوجرامات/هكتار).أوضح تحليل ثبات الإنتاجية  stability analysis بإســـــــتخدام نموذج Eberhart and Russell’s model بان جميع الهجن لها استجابات متباينة مع المتغيرات البيئية فى المواقع الخمسة وكان أفضل الأداء فى حلفا الجديدة (.(E4 كما أوضح التحليل بان الهجينين SFH37  و SFH310 هما من الهجن المستقرة و الثابتة الأداء لصفة أطوال النباتات و الهجينين SFH345  و SFH302 لصفة عدد البذور بالقرص ، بينما الهجن Hysun-33  ، SFH310، وSFH341 لصفتي النسبة المنخفضة من البذور الفارغة والوزن المرتفع للمائة بذرة علي التوالي. أوضحت الدراسة ان ثلاثة هجن محلية  (SFH310، SFH313 و SFH341) وخاصة الهجين SFH310 ، لها مقدرة إنتاجية عالية من البذور والزيت وثبات الإنتاجية فى البيئات الخمسة مقارنة مع الشاهد Hysun-33 وباقي الهجن ، بينما هجن اخرى مثل الهجينين SFH32  وSFH37  تعتبر حساسة للتغيرات البيئة فى إنتاجيتها من البذور والزيت. تم التعرف على الهجين SFH310 بأنه أكثر ثباتاً للإنتاجية ومكوناتها. الهجن السودانية الثلاثة الواعدة تمت إجازتها في يونيو 2009 للإنتاج التجاري والأنتاج المحلي لبذور الهجين SFH310 (بحوث-1= Bohooth-1) تم تبنيه من بعض منتجي البذور فى السودان. &nbsp

Turbulent flow in an idealized wing-body junction

Imperial Users onl

Different toughening strategies for UV-cured epoxy resins

Owing to their outstanding properties, epoxy resins are widely used in different industries and recently used in novel applications such as semiconductors and lithographic inks. Due to their low fracture toughness, Toughening of epoxy is widely discussed in literature during last decades. Many toughening agents including organic and inorganic materials are used to accomplish this purpose. The objectives of this research are to synthesize and use different toughening agents and study the influence of these modifiers on the mechanical and thermal properties in general and the fracture toughness in particular of the UV-cured cycloaliphatic epoxy resins. Particularly, we desired to improve the fracture toughness of modified epoxies cured via UV light without sacrificing their thermal and other mechanical properties. Polymeric molecules or ceramic nanoparticles have been introduced; (1) Hyperstar polymers based on hyperbranched polyester core with or without hydroxyl reactive groups in their arms (2) reactive core/shell polymeric nanoparticles prepared by seeded emulsion polymerization (3) reactive or nonreactive diblock copolymer prepared via ATRP and based on polyethylene oxide and (4) commercial alumina nanoparticles as inorganic particles. The effect of the addition of these toughening agents on the rate of UV-curing process and glass transition temperature, Tg, have been investigated. Subsequently, the morphology of the facture surfaces has been studied carefully using FE-SEM. The stress intensity factor, KIC, measurements which is an indicator for fracture toughness was evaluated in terms of single-edge-notch three-point-bending (SENB). Cationic UV-curing technique was utilized for the preparation of the modified epoxy composites. Specifically, the cationic photopolymerization of cycloaliphatic epoxy is known to proceed through nucleophilic attack of neutral monomer to oxonium cation, which is active chain end of the polymerization. The UV induced polymerization technique is a solvent free method occurring at room temperature which is eco-friendly. It is indeed a polymerization process used for industrial applications because of the high production rate and the low energy consumption compared to thermal processes. The rapid UV-curing process helps to maintain good dispersion of modified particles avoiding further aggregation that could occur during longer thermal treatment

Study of heterosis in single-cross hybrids of sunflower

    This study was conducted to estimate the genetic variability and heterosis of 40 F1 hybrids of sunflower for seed yield and its components over two seasons (summer and winter) in 2007 at Sennar Research Station Farm in central Sudan. The plant material consisted of 14 sunflower parents            (4 females and 10 males) and their 40 F1-hybrids. The experiment was arranged in a randomized complete block design with three replicates. The traits measured were days to 50% flowering, plant height, head diameter, number of seeds per head, one thousand seed weight and seed yield.  Hybrids showed high genetic variability for all traits studied than their parents which suggested some degree of hybrid vigor. The direction and magnitude of heterosis varied from cross to cross. Over two seasons, the average mid-parent heterosis in preferred direction and magnitude depicted that the hybrid SA2 x SR41 followed by SA3 x SR41 for days to flowering, SA1 x SR14 for plant height, SA2 x SR14 for head diameter, SA2 x SR13 followed by SA3 x SR13 for number of seeds per head, and SA3 x SR7 for one thousand seed weight. With regard to seed yield, the best hybrids with positive average heterosis were SA3 x SR41 (53.42%), SA4 x SR45 (52.75%), SA4 x SR1 (52.25%) and SA3 x SR10 (40.63%) which also combined with high seed yield of 1581 kg/ha, 1479 kg/ha, 1474 kg/ha, and 1457 kg/ha, respectively. These hybrids (involving the female line SA3 or SA4 and the male lines (SR10, SR13, SR41 and SR45) can be used in our breeding program in an attempt to develop local sunflower hybrid (s) with high seed yield and other important agronomic traits and for testing their yield potential and stability across locations and seasons.  أجريت هذه الدراسة بهدف تقدير التباين الوراثي و قوة الهجن  للإنتاجية ومكوناتها لأربعين هجين مفرد من محصول زهرة الشمس، نتجت من تهجين أربعة أمهات ذات عقم ذكرى سايتوبلازمى مع عشرة آباء معيدة للخصوبة. أجريت التجربة بمحطة بحوث سنار فى وسط السودان بالقطاع المروي لموسين             (صيف وشتاء2007). أستخدم تصميم القطاعات العشوائية الكاملة بثلاثة مكررات. كانت الصفات المدروسة هى عدد الايام حتى 50% إزهار، طول النبات، قطر القرص، عدد البذور بالقرص، وزن الآلف حبة، وانتاج البذور. أظهرت النتائج فروقات معنوية لكل الصفات في الموسمين مع تفوق الهجن وتباينها وراثياً مقارنة بالآباء. وفي التحليل المشترك لحساب قوة الهجين لكل الصفات كنسبة زيادة أو نقصان من متوسط الأبويين، ظهر أنّ الهــجينينSA2 x SR41  وSA3 x SR 41 هما الأفضل للإزهار والنضج المبكر، الهجين SA1 x SR14 لطول النبات، الهـجين SA2 x SR14 لقطر القرص ، الهجينين SA2 x SR13  و SA3 x SR13 لعدد البذور بالقرص، الهجين SA3 x SR7 لوزن الألف بذرة. أما بخصوص إنتاجية البذور أظهرت بعض الهجن نسبة قوة هجين موجبة SA3 x SR41 ) (53.42%، (52.73% ) SA4 x SR45،   SA4 x SR1   (52.25%)و SA3 x SR10 ((40.63% وإنتاجية بذور تقدر بـ 1581 كيلوجرام للهكتار، 1479 كيلوجرام للهكتار، 1474 كيلوجرام للهكتار و1459 كيلوجرام للهكتار علي التوالي. ويستنتج من هذه الدراسة ان الهجن التي يدخل في تركبيها الأم SA3 أو الأم SA4 مع الآباء SR41 ، SR45، SR13      و SR10 هى هجن متفوقة لإنتاجية البذور والصفات الأخرى ، ويمكن استخدام تلك الأمهات والآباء في تطوير هجن محلية مفردة من محصول الزهرة واختبار ثبات إنتاجيتها عبر المواسم والمواقع المختلفة

The power of some standard tests of stationarity against changes in the unconditional variance

Abrupt changes in the unconditional variance of returns have been recently revealed in many empirical studies. In this paper, we show that traditional KPSS-based tests have a low power against nonstationarities stemming from changes in the unconditional variance. More precisely, we show that even under very strong abrupt changes in the unconditional variance, the asymptotic moments of the statistics of these tests remain unchanged. To overcome this problem, we use some CUSUM-based tests adapted for small samples. These tests do not compete with KPSS-based tests and can be considered as complementary. CUSUM-based tests confirm the presence of strong abrupt changes in the unconditional variance of stock returns, whereas KPSS-based tests do not. Consequently, traditional stationary models are not always appropriate to describe stock returns. Finally, we show how a model allowing abrupt changes in the unconditional variance is well appropriate for CAC 40 stock returns.KPSS test, panel stationarity test, unconditional variance, abrupt changes, stock returns, size-power curve.

Surface Acoustic Wave (Saw) Delay Lines & Rfid on Silicon/ Aluminium Nitride

Surface Acoustic Wave (SAW) devices exploit the principle of transducing radio frequency waves into mechanical sound waves propagating across surface of piezoelectric material. These mechanical waves are generated, detected, or reflected by set of metal electrodes. Physical phenomena or unique identification code information can be extracted from the measured /reflected waves based on its different properties such as time delay, phase change or frequency change. Radio identification code implementation methods as well as simulation of SAW device are reviewed in this report. Time pulse position coding is chosen because it provides less sensitivity to variations in temperature and SAW wave velocity. In addition, it is straightforward to implement and simplifies the reader design. To successfully implement the device, proper modeling and simulation is carried out to extract device physical and response parameters such as centre frequency, finger pairs’ number, spacing, scattering parameters and frequency response of the system. The equivalent circuit model is used in this study due to faster simulation speed and efficiency. Aluminum nitride (AlN) is chosen as piezoelectric material due to its high SAW velocity speed, higher coupling factor, cheaper fabrication cost and its chemical characteristics close to that of Silicon Non-reactive with normal semiconductor process chemicals and gases. Data processing and analysis is performed on SAW delay lines implemented on Aluminum nitride to extract device characteristics such as surface acoustic wave velocity, coupling coefficient and center resonance frequency

Natural Products Chemistry of Leads Acting on MRSA, HCV, Malaria, and Depression Disorders

Nature has proven to be an endless source of abundant diversity of chemical entities with varying biological activities. The World Health Organization (WHO) estimates that 80% of the world\u27s population depends on traditional medicine for treating their everyday health problems. According to Gordon Cragg, former director of the natural products branch of the NCI, ″Nature has produced wonderfully complex molecules that no synthetic chemist could ever dream up.″ Moreover, he emphasized that over 60% of cancer therapeutics have been derived from nature whether directly through isolation or indirectly through semi-synthesis. Various examples have been reported such as extracts from Catharanthus roseus (Rosy Periwinkle) used for treatment of Hodgkin\u27s disease and leukemia, digitalis from Digitalis purpurea (foxglove) for treatment of heart disease, galantamine from Galanthus caucasicus (snowdrops) for treatment of Alzheimer\u27s disease, and paclitaxel from the bark of the Pacific yew tree to treat cancer. During the course of these studies, we researched the potential of natural products to provide drugs for treatment of human and plant diseases for which no adequate therapy exists. For instance, methicillin-resistant Staphylococcus aureus (MRSA) is a destructive pathogen with a high patient mortality rate. Over 50% of the Staph. aureus infections around the world are caused by MRSA. In the first chapter, we will address the bioassay-guided isolation and characterization of a series of anti-MRSA active glycosides that exhibit a high degree of selectivity for MRSA from the leaves of the comAmerican sycamore, Platanus occidentalis. The isolated metabolites; E,E-platanoside [kaempferol 3-O-α-L-(2\u27\u27,3\u27\u27-di-E-pcoumaroyl)rhamnoside, IC50 2.0 µg/mL], E,Z-platanoside [kaempferol 3-O-α-L-(2\u27\u27-E-pcoumaroyl-3\u27\u27-Z-p-coumaroyl)rhamnoside, IC50 0.8 µg/mL], Z,E-platanoside [kaempferol 3-O-αL-(2\u27\u27-Z-p-coumaroyl-3\u27\u27-E-p-coumaroyl)rhamnoside, IC50 0.7 µg/mL], and Z,Z-platanoside [kaempferol 3-O-α-L-(2\u27\u27,3\u27\u27-di-Z-p-coumaroyl)rhamnoside, IC50 0.4 µg/mL] have been shown to prevent growth of MRSA on surfaces and systemically. The in vitro anti-MRSA activity of these metabolites indicated that changing the configuration of the double bond in the p-comaroyl units greatly affects the MRSA activity. This, in turn, encouraged us to establish economic methods to transform the less active E,Eplatanoside to the more active Z, Z-platanoside. Light-mediated isomerization in platanosides provides a precise, noninvasive, and “green” approach for controlling MRSA activity. In the second chapter, the development of a simple “green” chemistry approach is described that uses light induced photoisomerization for transforming the thermodynamically stable E,E-platanoside to the Z,E-, E,Z- and Z,Z-platanosides. This provided support for the light mediated photoisomerization over the enzymatic control theory for the biosynthesis formation of the Zisomers. American sycamore is significant to the forest products industry due to its use as pulpwood for making paper and fiberboard, and sawlogs for manufacturing butcher\u27s blocks, furniture, interior trim, boxes, and flooring. Historically, American sycamore has held, and continues to hold, good potential as a dedicated biofuels crop grown on short rotations in plantations. However, the growth and productivity of sycamore plantations is hampered by bacterial leaf scorch disease (BLS) caused by Xylella fastidiosa. Strains of this bacterium are the major cause of various plant diseases such as phony peach disease (PPD), plum leaf scald (PLS), and Pierce\u27s disease (PD) of grapes, citrus variegated chlorosis (CVC), and leaf scorch of almond, oleander, and pear. The isolated anti-MRSA metabolites are found in greater concentrations in healthy sycamore trees versus diseased trees suggesting an ecological link between tree health and glycoside content. The third chapter describes this ecological link and presents data that demonstrates the ability of the metabolites to inhibit X. fastidiosa at nanomolar concentrations (MIC ≤ 17-67 nM). The presence of these metabolites in sycamore has the potential to be a useful analytical tool for selecting disease-resistant strains. Depression is the most comdisease of the central nervous system affecting approximately 17% of Americans each year. According to the National Institute of Mental Health (NIMH), every year about 40 million American adults suffer from anxiety disorders that frequently co-occur with other psychiatric illnesses like depression. Recently, our group reported the isolation of several marine indole alkaloids and evaluated their biological activity in the forced swim (FST) and locomotor activity tests, revealing their potential to become new antidepressant drug leads. Among the isolated compounds, 5-bromo-N,N-dimethyltryptamine was found to display a high sedative effect in the locomotor activity test. Owing to the limited amounts of this compound obtained from isolation, a synthetic approach was adopted to prepare 5-bromo-N,N-dimethyltryptamine and its derivatives to study the structure activity relationships (SAR) and complete the dose-response experiments. In the fourth chapter, the synthesis is described of a series of 2-(5-halo-1H-indol-3-yl)-N,N-dimethylethanamines, as is the evaluation of their in vivo antidepressant and sedative activities using the FST and locomotor activity tests. Of the synthetically prepared compounds, 2-(1H-indol-3-yl)-N,N-dimethyl-2-oxoacetamide, 2- (5-chloro-1H-indol-3-yl)-N,N-dimethyl-2-oxoacetamide, 2-(1H-indol-3-yl)-N,Ndimethylethanamine, 2-(5-chloro-1H-indol-3-yl)-N,N-dimethylethanamine, and 2-(5-iodo-1Hindol-3-yl)-N,N-dimethylethanamine have been shown to possess antidepressant-like action. Dose response studies were completed for the active compounds. Manzamine A is an alkaloid that contains a unique multi-heterocyclic ring system coupled to a β-carboline moiety. Manzamine A shopotent in vitro antimalarial activity against P. falciparum D6 and W2 (0.017-0.020 µM), but its toxicity hindered its development as a drug lead. Malaria, a major tropical infectious disease caused primarily by the protozoan parasite Plasmodium falciparum, is responsible for the death of more than 1.12 million individuals every year. Recently, Ihara reported that the π-delocalized lipophilic cationic (DLC) structures of various β-carboline natural products, display reasonable antimalarial activity against P. falciparum with low cytotoxicity against mammalian cells. The fifth chapter describes the synthesis of mono- and di-methylated quaternary carbolinium cations of manzamine A and evaluations of their in vitro antimalarial and antimicrobial activities, cytotoxicity, and also their potential for glycogen synthase kinase (GSK-3β) inhibition using molecular docking studies. Among the analogs, 2-N-methylmanzamine A exhibited antimalarial activity (IC50 0.7 – 1.0 µM), but was less potent than manzamine A. However, the compound was significantly less cytotoxic to mammalian kidney fibroblasts with a selectivity index in the same range as manzamine A. One of the most serious threats to humans is hepatitis C virus (HCV) infections affecting approximately 4 million individuals in the United States, and 200-300 million individuals worldwide, causing over 8,000 deaths each year. HCV can progress to severe liver disorders such as fibrosis, cirrhosis, and hepatocellular carcinoma. A rare Latin American plant extract provided through collaboration with the National Cancer Institute (NCI) repository (No. 77951) shopotent anti-HCV activity. Diplostephium rhododendroides (family Asteraceae) is only found between Ecuador and Colombia and has not been subjected to phytochemical screening. The last chapter describes the isolation and identification from this rare plant of anti-HCV oleanane-triterpenes complex glycosides with m/z of 1700-1800. The isolated rhododendrosaponins I-III have shown exceptional activity (EC50 0.2 µg/mL) against HCV and warrant further evaluations

A non-invasive diagnostic system for early assessment of acute renal transplant rejection.

Early diagnosis of acute renal transplant rejection (ARTR) is of immense importance for appropriate therapeutic treatment administration. Although the current diagnostic technique is based on renal biopsy, it is not preferred due to its invasiveness, recovery time (1-2 weeks), and potential for complications, e.g., bleeding and/or infection. In this thesis, a computer-aided diagnostic (CAD) system for early detection of ARTR from 4D (3D + b-value) diffusion-weighted (DW) MRI data is developed. The CAD process starts from a 3D B-spline-based data alignment (to handle local deviations due to breathing and heart beat) and kidney tissue segmentation with an evolving geometric (level-set-based) deformable model. The latter is guided by a voxel-wise stochastic speed function, which follows from a joint kidney-background Markov-Gibbs random field model accounting for an adaptive kidney shape prior and for on-going visual kidney-background appearances. A cumulative empirical distribution of apparent diffusion coefficient (ADC) at different b-values of the segmented DW-MRI is considered a discriminatory transplant status feature. Finally, a classifier based on deep learning of a non-negative constrained stacked auto-encoder is employed to distinguish between rejected and non-rejected renal transplants. In the “leave-one-subject-out” experiments on 53 subjects, 98% of the subjects were correctly classified (namely, 36 out of 37 rejected transplants and 16 out of 16 nonrejected ones). Additionally, a four-fold cross-validation experiment was performed, and an average accuracy of 96% was obtained. These experimental results hold promise of the proposed CAD system as a reliable non-invasive diagnostic tool