Root-knot nematodes: abundance in organic farming, differentiation among populations, microbes attached to juveniles in soil, and bacterial antagonists

In zwei umfassenden Untersuchungen im Herbst 2009 und 2011 wurde die Verbreitung und die Abundanz pflanzenparasitärer Nematoden an den verschiedenen Feldfrüchten in einer Bio-Farm in Ägypten erfasst. Insgesamt wurden elf Genera gefunden, von denen Wurzelgallen-Nematoden (Meloidogyne spp.) in beiden Untersuchungen am häufigsten und mit der höchsten Anzahl in den Proben gefunden wurde. Weitere oft gefundene Genera waren Tylenchorhynchus, Rotylenchulus, Helicotylenchus und Pratylenchus. Davon ausgehend beschäftigten sich die weiteren Arbeiten mit Meloidogyne, und zwar mit der Differenzierung von Populationen, der Anheftung von Mikroorganismen an die Juvenile (J2) im Boden, und der biologischen Kontrolle durch Bakterienstämme, die als Antagonisten von pilzlichen Pathogenen bekannt sind. Die untersuchten Populationen und/oder Rassen von Meloidogyne incognita zeigten phänotypische Unterschiede in ihren Vermehrungsmustern an einem Set von Wirtspflanzen. Damit einhergehend konnten auch genetische Unterschiede anhand einer neu entwickelten Methode zur Amplifikation des Pathogenitätsgens msp1 und der elektrophoretischen Auftrennung der PCR-Produkte von Genvarianten im Denaturierungsgradienten (DGGE) nachgewiesen werden. Für drei Ackerböden aus verschiedenen Regionen in Deutschland wurde unterschiedliche Suppressivität ihrer mikrobiellen Gemeinschaften gegen Meloidogyne hapla im Gewächshaus gezeigt. Mit Kultivierungs-unabhängigen Methoden wurde untersucht, welche Mikroorganismen an die J2 in den Böden anheften, um die zu identifizieren, die mit J2 im suppressivsten der drei Böden spezifisch interagierten (Kleinwanzleben). Die Mikroorganismen, die an den J2 nach Inkubation im Boden haften blieben, unterschieden sich zwischen den drei Böden. In PCR-DGGE Fingerprints von ITS-Fragmenten bzw. 16S rRNA Genen wurden viele Pilze und Bakterien detektiert, die an den J2 aber nicht im umgebenden Boden abundant waren. Während sich einige davon in allen drei Böden an den J2 anreicherten, waren andere spezifisch für einen Bodentyp. Mittels Pyrosequenzierung von 16S rRNA Gen-Amplikons konnten die mit J2 im suppressivsten Boden assoziierten abundantesten Bakterienarten beschrieben werden. Viele davon waren verwandt mit infektiösen Arten wie Shigella spp., während Malikia spinosa und Rothia amarae am häufigsten detektiert wurden. Krankheitskomplexe aus Nematode und Pilz können erhebliche synergistische Ertragsverluste verursachen. Bakterienstämme, die als Antagonisten von phytopathogenen Pilzen bekannt sind, wurden auf ihr Potential zur biologischen Kontrolle von M. incognita untersucht. Sameninokulation führte bei den meisten Stämmen zu einer signifikanten Reduktion der Vermehrung des Nematoden an Tomatenwurzeln. Für die drei besten Isolate, Bacillus subtilis Sb4-23, Mc2-Re2 und Mc5- Re2, wurden die zugrundeliegenden Mechanismen untersucht. Die Stämme konnten den Nematoden sowohl direkt durch Metabolite beeinträchtigen, die im Kulturüberstand zu finden sind, als auch indirekt über Induktion systemischer Resistenz der Pflanze. Im experimentellen Vergleich der direkten und Pflanzenvermittelten Effekte zeigte sich, dass letzteres der dominierende Kontrollmechanismus dieser Antagonisten ist. Zusammen genommen könnten diese Befunde als Basis für eine verbesserte Strategie zum integrierten Management von Wurzelgallen-Nematoden im biologischen Landbau dienen.Two surveys were conducted to determine the frequency and abundance of plantparasitic nematodes associated with different crops at an organic farm in Egypt, during autumn 2009 and 2011. Eleven genera of plant-parasitic nematodes were detected. Root-knot nematodes (Meloidogyne spp.) showed the highest abundance and frequency of all plant-parasitic nematodes during the two surveys. Commonly detected genera were Tylenchorhynchus, Rotylenchulus, Helicotylenchus and Pratylenchus. Further studies on Meloidogyne were carried out with regard to discrimination among populations, attachment of microbes to juveniles (J2) in soil, and biocontrol through bacterial strains which were known as antagonists of fungal pathogens. Meloidogyne incognita populations and/or races that showed differential pattern of reproduction on a set of host plants, could be differentiated based on a newly developed PCR-DGGE system to electrophorecically separate variants of the pathogenicity gene msp1. Three arable soils from different regions of Germany were shown to vary in the suppressiveness of their indigenous microbial communities against Meloidogyne hapla. Attachment of microbes to J2 in these three soils was investigated by cultivation-independent methods to identify those which specifically interacted with J2 in the most suppressive soil (Kleinwanzleben). The three soils differed in the microbes attached to J2. PCR-DGGE fingerprints of amplified ITS fragments or 16S rRNA genes showed many fungi and bacteria that were abundant on J2 but not in the surrounding soil, some of which seemed to be present in all three soils while most were soil type specific. Many bacteria associated with J2 from the most suppressive soil were closely related to infectious species like Shigella spp., while most abundant were Malikia spinosa and Rothia amarae as determined by 16S rRNA gene amplicon pyrosequencing. Nematode-fungus disease complexes can cause dramatic synergistic yield losses. Bacterial strains known as antagonists of phytopathogenic fungi were evaluated with respect to their biocontrol potential towards M. incognita. Seed inoculation with most of the strains significantly reduced propagation of nematode on tomato roots. The best strains Bacillus subtilis Sb4-23, Mc2-Re2, and Mc5- Re2 were further studied for their mode-of-action. The strains were able to affect the nematodes directly by metabolites present in culture supernatants and indirectly by induced systemic resistance of the plant. Experimental comparison of direct and plantmediated effects suggested that the latter was the major control mechanism of these antagonists. Overall, these findings may improve the basis for integrated management strategies of root-knot nematodes in organic farming

DETERMINATION OF THE AREA AFFECTED BY THE SPREAD OF BURNING FUEL DUE TO BOILOVER

Boilover is one of the most dangerous accidents that can happen in an atmospheric hydrocarbons storage tank, it happens when the water at the bottom of the storage tank is heated to a temperature where it is evaporate and push’s the hydrocarbons out of the tank causing a ground fire and flame enlargements. And the main objective of this study is determination of the area affected by the spread of ejected hydrocarbons from the storage tank due to boilover causing a ground fire which is extremely dangerous. And for achieving this objective a set of experiments have been performed on a hydrocarbons mixture consisting of 50 % Diesel oil and 50% Gasoline is used. This mixture has been chosen after running some experiments on three different types of mixtures. Tow set of experiments have been performed and from the result analysis we were able to find equation relating the volume of the mixture in the storage tank to the area affected. And from both set of experiments we found that the relation between the fuel volume and the area affected is best described as a polynomial relationship. Moreover a different set of experiments is also performed using crude oil which gave an unpromising result and we were unable to find an equation relating the area affected to the crude oil volume in the storage tank

Rural women participation in the agricultural activities in the Gezira Scheme, Sudan

   أجريت هذه الدراسة لتقييم مشاركة المرأة الريفية في التنمية الزراعية بالمناطق المروية. شملت دراسة حالة المرأة بمشروع الجزيرة. اختيرت عينة الدراسة من خمس قرى، واستخدمت طريقة الكوتة لاختيار100 امرأة يمثلون عينة الدراسة. المعلومات الأولية جمعت عن طريق المقابلة الشخصية باستخدام استبانة معدة لذلك الغرض. وتم استخدام عدد من الطرق الإحصائية لتحليل المعلومات و لاختبار فروض الدراسة من بينها  الجداول والتكرارات. ومن النتائج التي توصلت إليها الدراسة أن النساء المزارعات بالجزيرة ذوى خبرة في أداء العمليات الزراعية، إضافة إلى ممارستهن للأعمال غير مدفوعة الأجر. واشتملت الدراسة تأسيسا على النتائج عدة توصيات من شانها أن تسهم في تحسين مشاركة المرأة في التنمية الزراعية بصفة عامة، بجانب توفير الخدمات الزراعية للنساء، وأهمها المدخلات (أسمدة، تقاوي ومبيدات) إضافة لتوفير الخدمات العامة للمرأة الريفية لكي تخفف من الأعباء التي تقوم بها مثل خدمات التعليم، الصحة وتوفير مياه الشرب. &nbsp

Simulation of ship motion and deck-wetting due to steep random seas

The extreme motion and load of ships have been assessed using a linear frequency domain method or a linear energy spectral method and RAOs, which may be too approximate to be used for estimation of ship motion in severest seas. The new technology uses simulation in the time domain to deal with the non-linear responses to the random seas. However, the current simulation technique has been successful only up to the sea state of 7 (high seas), defined by the significant wave height of 9 meters. The above cannot provide the extreme wave loads and motions for seas higher than the sea state 7. The ultimate goal of this work would be to develop a new technique that can simulate responses to the seas of states 8 and 9. The objective of the present study is to simulate the vertical relative motion and wave topping of a moored ship in the time domain by varying the significant wave heights. The analysis was able to predict with a fair accuracy the relative motion characteristics of a freely floating body in the head and beam sea conditions. The resonance aspects and its significance in the overall response are also analyzed

Towards a cosmopolitan theory of modernity : a comparative historical analysis of emerging Buddhist, Islamic and Post-Christian modernities

Current theories of modernity, an international phenomenon, have been criticized for being Eurocentric, and attempts to address their problem of Eurocentrism are at best semi-Eurocentric. This thesis suggests a new theory of modernity, the Theory of Transhistorical Modernity (TTM), that is arguably more empirically robust and, being non-ethnocentric and cosmopolitan, normatively sounder. Taking an interdisciplinary approach, this theory is underpinned by a rethinking of the dichotomies of tradition/modernity, religion/secularity, and collectivism/individualism. This thesis takes a historical–sociological International Relations approach to the study of modernity, employing the comparative historical methods for data collection and analysis. Through the lens of this new theoretical framework, the post-Christian nationalist modernity is but one among many modernities in history. Out of this plurality, three cases are selected, analyzed, and then compared to illustrate the theory and reach a better understanding of modernity in general and of these cases in particular: Axial Buddhist modernity (6th–3rd centuries BCE), early Islamic modernity (7th–13th centuries CE), and the post-Christian nationalist modernity (17th–20th centuries CE). Analysis of these cases shows that modernity is a transhistorical phenomenon with different historical manifestations. Early Buddhism and early Islam, for instance, are not the antitypes of Western modernity but were themselves modernities. Through this new theory, I argue that intercultural influence is transhistorical, and the agency to enact innovative social change or modernize is not a Western invention but a transhistorical human capacity. TTM reclaims the West’s theft of the cosmopolitan, transhistorical value and agency of modernization.M-I

Soil compaction loosener

Soil compaction is a potential problem in many agricultural soils due to the increasing mass of agricultural vehicles and equipment and tendency of farmers to work fields when soil is wet. A review of literature showed that some control measures can be taken such as controlling traffic to reduce compaction or use of tillage to remove the effects of compaction. Many implements have been used to loosen compacted soil, but in their design compaction depth was not considered and also these implements are designed for full width tillage as opposed to tillage only in the zone that has been compacted by traffic. A controllable device that would remove soil compaction immediately after being trafficked by the agricultural vehicle is needed;A relationship between compaction depth and sinkage depth was developed from literature describing previous research. Laboratory and field experiments were conducted to verify this relationship. In the laboratory experiment soil at varying water contents was compacted with a metal plate made to simulate the tractor tire. Different stresses were used to create different sinkage depths. Bulk density and sinkage depth formed as a result of stress applied were measured. Bulk density of the control soil was subtracted from bulk density of the compacted soil and the difference was used to determine the depth at which the stress applied increased bulk density by 0.05 Mg/m[superscript]3. In the field experiment, a tractor with different tire inflation pressures and with different axle loads was used to traffic plots to create different sinkage depths. Bulk density samples were taken and analyzed as in the laboratory experiment to determine the compaction depth. A curve fitting technique was used to determine the best curve to represent the data. Results showed that compaction depth, Y, can be related to sinkage depth, X, by the empirical relationship, Y = bX[superscript] m where b and m are constants. The laboratory experiment on Webster silty clay loam soil showed compaction depth to be related to sinkage depth by Y = 52.5X[superscript]0.32 with R[superscript]2 of 0.82. The field experiment on Nicollet loam soil showed compaction depth to be related to sinkage depth by Y = 13.9X[superscript]0.73 with R[superscript]2 of 0.50;A double layer soil compaction loosener was developed. The design chosen was selected from three models tested on dry and wet soil in an indoor soil bin. A field experiment to measure sinkages formed by a tractor with different inflation pressures on the rear tires and different axle loads was conducted to evaluate the performance of the loosener. Depth of tillage with the loosener was controlled by the equation Y = 13.9X[superscript]0.73. Tillage of the trafficked soil with the soil loosener reduced bulk density from 1.48 to 1.26 Mg/m[superscript]3 and cone index from 406 to 55 kPa