311 research outputs found

    Poultry manure effect on growth and yield of maize

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    The effect of poultry manure application on maize (Zea mays) growth and yields was studied on a Ferric Acrisol in the semi-deciduous rain forest zone of Ghana. Eight treatments of 0, 2, 4, 6, 8 tons of poultry manure (pm) per hectare, 60-40-40 kg NPK/ha, 2 × 2 t pm/ha and 2 t pm + 30-20-20 kg NPK/ha were used in a randomized complete block design (RCBD) with five replications. The study showed that poultry manure is a valuable fertilizer and can serve as a suitable alternative to chemical fertilizer in the forest zone of Ghana. Poultry manure treatments produced higher values for height, leaf area index and biomass. The 4 t pm/ha rate produced maize grain yield of 2.07 t/ha which was statistically not different from that of the chemical fertilizer rate (2.29 t/ha) and 6 t pm/ha (2.60 t/ha), while the 6 t pm/ha was not statistically different from the 8 t pm/ha rate. Split application of 4 t pm/ha (i.e. 2 × 2 t pm/ha) and 2 t pm/ha + 30-20-20 kg NPK/ha gave similar biomass and grain yields as the 4 t pm/ha. Poultry manure application registered over 53% increases of N levels in the soil, from 0.09% to 0.14%. Exchangeable cations increased with manure application. The study recommends an application rate of 4 t pm/ha for maize on this type of soil in this agro-ecolog

    Introduction: Early Modern Scottish-Scandinavian Studies

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    First paragraph: In a field which has always been a by-word for internationalism, it is only appropriate that the foundational volume of modern Scottish-Scandinavian studies was written neither by a Scot nor a Scandinavian, but rather by the Lübeck-born historian and translator, Thomas Alfred Fischer (1844-1906). By the time Fischer came to write his Scots in Sweden: Being a Contribution Towards the History of the Scot Abroad (posthumously published in 1907), he had already established a name for himself as Europe’s leading authority on the early modern Scottish diaspora. In 1902, he had published The Scots in Germany, which was rapidly followed by The Scots in Eastern and Western Prussia in the following year

    English and Scottish Exiles in Northwest Germany c. 1683–1709

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    The politically and culturally diverse north western territories of the Holy Roman Empires so far lack an analysis of Scottish exile communities which could hold up to the work published on seventeenth century exiles communities in the United Provinces or Poland-Lithuania. This is unfortunate as some German territories and cities received intensive attention from English and Scottish religious and political exiles who had left or were in the process of leaving the British Isles during the Restoration period seeking refuge on the continent. Although a majority of these exiles found support within expatriate communities established in Dutch cities, some Scots and Englishmen aimed to relocate to other Northern European locations due to safety issues or economic opportunities. In November 1683 the Englishman Sir William Waller, accompanied by the Scots Adam Freer and Sir George Melville, led negotiations with the senate of the Calvinist and Imperial city of Bremen for the settlement of Scottish and English exiles. When these failed due to pressure exerted by Charles II, talks continued with the Lutheran duke Georg Wilhelm of Braunschweig-Lüneburg. On 9 August 1684, the latter issued religious and economic privileges to families and individuals of reformed faith belonging to any nation who were willing to settle in the city of Lüneburg. These freedoms led not only to English and Scottish but also to French and Dutch migration of religious and political exiles as well as of economic opportunists. This article analyses the aims of the exiles and their negotiations with the local authorities in North West Germany. It also examines the success and failure of the communities in Bremen and Lüneburg and their long-term impact on individuals such as the Scottish entrepreneur Robert Hog. Furthermore, the articles analyses if the diverse migration of individuals of several nationalities resulted in the formation of a single British or multi-ethnic religious community or if the migrants organised themselves in several groups, divided by nationality or other criteria.Le rôle des communautés d’exilés écossais dans les territoires politiquement et culturellement diversifiés du Saint-Empire romain germanique n’a pas fait l’objet d’études, à l’opposé de celles qui existent sur les communautés d’exilés aux Provinces-Unies ou en Pologne-Lituanie au xviie siècle. Cela est regrettable car certains territoires et villes allemands suscitaient un très vif intérêt chez les exilés religieux et politiques de l’Écosse et de l’Angleterre qui quittaient les Îles Britanniques pendant la Restauration afin de trouver refuge sur le continent. Bien que la majorité de ces exilés fussent accueillis au sein des communautés d’expatriés des villes néerlandaises, certains Écossais et Anglais espéraient s’installer dans d’autres villes du nord de l’Europe pour des raisons de sécurité ou des motifs économiques. En novembre 1683, un Anglais, Sir William Waller, accompagné par deux Écossais, Adam Freer et Sir George Melville, mena des négociations avec le Sénat de Brême, ville impériale et calviniste, au sujet de l’installation d’exilés écossais et anglais. Suite à l’échec de ces pourparlers, dû à la pression exercée par Charles II, des négociations se poursuivirent avec le duc luthérien Georg Willhelm de Braunschweig-Lüneburg. Le 9 août 1684, ce dernier accorda des privilèges religieux et économiques aux familles et aux particuliers adhérant à la foi protestante qui souhaitaient s’installer à Lüneburg, sans considération de leur pays d’origine. Ces libertés ont attiré nombre d’exilés religieux et politiques d’origine anglaise et écossaise, mais aussi française et néerlandaise, venant s’ajouter à ceux qui s’exilaient pour des raisons économiques. Cet article cherche à analyser les objectifs des exilés ainsi que leurs négociations avec les autorités locales dans le nord-ouest de l’Allemagne. Nous étudions également la réussite et l’échec des communautés de Brême et de Lüneburg ainsi que leur impact durable sur des individus comme l’entrepreneur écossais Robert Hog. En dernier lieu, cet article cherche à savoir si la migration de ressortissants de nationalités différentes résultait en la création d’une seule communauté religieuse britannique ou multiethnique, ou si les migrants s’organisaient en différents groupes selon des critères nationaux ou autres

    Structure of a Complete ATP Synthase Dimer Reveals the Molecular Basis of Inner Mitochondrial Membrane Morphology

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    We determined the structure of a complete, dimeric F1Fo-ATP synthase from yeast Yarrowia lipolytica mitochondria by a combination of cryo-EM and X-ray crystallography. The final structure resolves 58 of the 60 dimer subunits. Horizontal helices of subunit a in Fo wrap around the c-ring rotor, and a total of six vertical helices assigned to subunits a, b, f, i, and 8 span the membrane. Subunit 8 (A6L in human) is an evolutionary derivative of the bacterial b subunit. On the lumenal membrane surface, subunit f establishes direct contact between the two monomers. Comparison with a cryo-EM map of the F1Fo monomer identifies subunits e and g at the lateral dimer interface. They do not form dimer contacts but enable dimer formation by inducing a strong membrane curvature of ∼100°. Our structure explains the structural basis of cristae formation in mitochondria, a landmark signature of eukaryotic cell morphology

    Nitrogen use efficiency of poultry manure by maize

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    Nitrogen use efficiency is a measure of the extent to which a crop transforms available N to economic yield. Poultry manure is often reported to have lower N use efficiency than mineral fertilizer in the first year of application. However, under certain conditions such as rate of application, N mineralization rate, type of soil and crop, the converse may be the case. Will a farmer be better off in applying poultry manure at a particular rate than mineral fertilizer? A study was conducted on a forest acrisol to determine the physiological and apparent N efficiencies of poultry manure (PM) applied at various rates and mineral fertilizer to maize. Poultry manure rates of 2, 4, 6, 8 and 2 x 2 t ha-1 (i.e. split application) showed higher physiological N use efficiencies than the mineral fertilizer rate of 60-40-40 kg NPK ha-1 and 2 t PM ha-1 + 30-20-20 kg NPK ha-1. However, the mineral fertilizers (including combined half rate plus 2 t poultry manure) had the highest apparent N use efficiencies of 58% and 40% respectively, but low physiological N use efficiency. Among the poultry manure treatments, 4 t ha-1 with the highest N content of 2.17% in the maize ear leaves and grain N content of 12.56 g kg-1, had the highest physiological N use efficiency of 60 kg ha-1 making it the most efficient rate in the transformation of N into grain yield. Journal of Science and Technology (Ghana) Vol. 27 (2) 2007: pp. 71-7

    Tunnel dynamics of quinone derivatives and its coupling to protein conformational rearrangements in respiratory complex I

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    Respiratory complex I in mitochondria and bacteria catalyzes the transfer of electrons from NADH to quinone (Q). The free energy available from the reaction is used to pump protons and to establish a membrane proton electrochemical gradient, which drives ATP synthesis. Even though several high-resolution structures of complex I have been resolved, how Q reduction is linked with proton pumping, remains unknown. Here, microsecond long molecular dynamics (MD) simulations were performed on Yarrowia lipolytica complex I structures where Q molecules have been resolved in the similar to 30 angstrom long Q tunnel. MD simulations of several different redox/protonation states of Q reveal the coupling between the Q dynamics and the restructuring of conserved loops and ion pairs. Oxidized quinone stabilizes towards the N2 FeS cluster, a binding mode not previously described in Yarrowia lipolytica complex I structures. On the other hand, reduced (and protonated) species tend to diffuse towards the Q binding sites closer to the tunnel entrance. Mechanistic and physiological relevance of these results are discussed.Peer reviewe

    Beanspruchungsmerkmale des heutigen Spitzentennis und Anforderungen an die Trainingspraxis

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    Abstract Die vorliegende Arbeit befasst sich mit dem Beanspruchungsprofil des modernen Spitzentennis und den daraus resultierenden Anforderungen an die Trainingspraxis unter besonderer Berücksichtigung des langfristigen Leistungsaufbaus. Im Rahmen des ersten Untersuchungsabschnitts wird in einer praxisnahen Studie mithilfe von 20 Leistungstennisspielern der Einfluss von Veränderungen der Belastungsnormative auf den Trainingserfolg mithilfe zahlreich erhobener Parameter systematisch überprüft. Hierbei wird eine intensive Trainingsmethode einer matchorientierten Trainingsmethode am Beispiel von zwei verschiedenen Ballmaschinentests sowie einer matchsimulativen freien Spielform gegenübergestellt. Ergänzend hierzu liefern die Resultate einer Expertenbefragung von 16 qualifizierten und erfahrenen Tennistrainern wichtige Erkenntnisse aus der Trainingspraxis im Leistungstennis. Innerhalb des zweiten Untersuchungsabschnitts werden Ergebnisse einer umfassenden Testreihe zur Diagnostik von tennisspezifischer Schnelligkeit und Kraft jugendlicher Nachwuchsathleten (n=160/Jahr) im Rahmen des DTB-Talent-Cups (U12) in den Jahren 2004 bis 2007 präsentiert. Der zentrale Fokus dieser Studie richtet sich dabei auf die Entwicklung der Schnelligkeits- und Kraftleistungen in dem Beobachtungszeitraum und deren Stellenwert im Hinblick auf das Beanspruchungsprofil im modernen Spitzentennis. Darüber hinaus werden geschlechtsspezifische Unterschiede sowie ein möglicher Zusammenhang zwischen den Platzierungen bei den Diagnostiken und den Platzierungen auf den jeweiligen DTB-Ranglisten überprüft. Aus den vorliegenden Befunden der durchgeführten Untersuchungsreihen lassen sich zahlreiche praxisrelevante Erkenntnisse gewinnen. Die zunehmende Professionalisierung und die damit verbundenen gesteigerten Anforderungen im heutigen Spitzentennis erfordern moderne Trainingskonzepte. Um den hohen Ansprüchen des derzeitigen Leistungstennis gerecht zu werden, muss frühzeitig sehr systematisch, individuell und überwiegend intensiv trainiert werden. Eine Optimierung der Trainingsqualität kann dabei einen ausschlaggebenden Beitrag hinsichtlich einer erfolgreichen Tenniskarriere leisten. Abstract The present work addresses the task profile of the modern world-class tennis and the resulting requirements on the training practice, with special attention to the long-term performance. A first empiric part reviewed systematically the impact of changes in the training load by numerous upraised parameters in 20 semi-professional tennis players. In this context an intensive training method and a match-related training method are compared by two different ball machine tests and a match-simulated training form. In addition the results of an expert's questioning of 16 certified and experienced tennis trainers provide important information of training practice in high performance tennis. The second part results of a comprehensive test battery regarding the diagnosis of tennis specific running speed and strength of cadre athletes (n=160/year). Results of the DTB-Talent-Cup (U12) in the years 2004 to 2007 are presented. This part focused on the development of speed and strength performance in the observation period and their significance in relation to the task profile in the modern top tennis. In addition, gender differences and a possible association between the rankings in the diagnostics and the placements on the respective DTB rankings are reviewed. The present findings offer a numerous relevant practical insights. The high professionalization and the increased task profile in today's top tennis require advanced training concepts. It is imperative to start professional training since childhood and to exercise very systematically, individually and predominantly intensely. The optimization of the training quality can make a decisive contribution with regard to a successful tennis career

    Ion transfer mechanisms in Mrp-type antiporters from high resolution cryoEM and molecular dynamics simulations

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    Multiple resistance and pH adaptation (Mrp) cation/proton antiporters are essential for growth of a variety of halophilic and alkaliphilic bacteria under stress conditions. Mrp-type antiporters are closely related to the membrane domain of respiratory complex I. We determined the structure of the Mrp antiporter from Bacillus pseudofirmus by electron cryo-microscopy at 2.2 angstrom resolution. The structure resolves more than 99% of the sidechains of the seven membrane subunits MrpA to MrpG plus 360 water molecules, including similar to 70 in putative ion translocation pathways. Molecular dynamics simulations based on the high-resolution structure revealed details of the antiport mechanism. We find that switching the position of a histidine residue between three hydrated pathways in the MrpA subunit is critical for proton transfer that drives gated trans-membrane sodium translocation. Several lines of evidence indicate that the same histidine-switch mechanism operates in respiratory complex I.Peer reviewe

    Docking and molecular simulations reveal a quinone-binding site on the surface of respiratory complex I

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    The first component of the mitochondrial electron transport chain is respiratory complex I. Several high-resolution structures of complex I from different species have been resolved. However, despite these significant achievements, the mechanism of redox-coupled proton pumping remains elusive. Here, we combined atomistic docking, molecular dynamics simulations, and site-directed mutagenesis on respiratory complex I from Yarrowia lipolytica to identify a quinone (Q)-binding site on its surface near the horizontal amphipathic helices of ND1 and NDUFS7 subunits. The surface-bound Q makes stable interactions with conserved charged and polar residues, including the highly conserved Arg72 from the NDUFS7 subunit. The binding and dynamics of a Q molecule at the surface-binding site raise interesting possibilities about the mechanism of complex I, which are discussed.Peer reviewe

    Essential role of accessory subunit LYRM6 in the mechanism of mitochondrial complex I

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    Respiratory complex I catalyzes electron transfer from NADH to ubiquinone (Q) coupled to vectorial proton translocation across the inner mitochondrial membrane. Despite recent progress in structure determination of this very large membrane protein complex, the coupling mechanism is a matter of ongoing debate and the function of accessory subunits surrounding the canonical core subunits is essentially unknown. Concerted rearrangements within a cluster of conserved loops of central subunits NDUFS2 (beta 1-beta 2(S2) loop), ND1 (TMH5-6(ND1) loop) and ND3 (TMH1-2(ND3) loop) were suggested to be critical for its proton pumping mechanism. Here, we show that stabilization of the TMH1-2(ND3) loop by accessory subunit LYRM6 (NDUFA6) is pivotal for energy conversion by mitochondrial complex I. We determined the high-resolution structure of inactive mutant F89A(LYRM6) of eukaryotic complex I from the yeast Yarrowia lipolytica and found long-range structural changes affecting the entire loop cluster. In atomistic molecular dynamics simulations of the mutant, we observed conformational transitions in the loop cluster that disrupted a putative pathway for delivery of substrate protons required in Q redox chemistry. Our results elucidate in detail the essential role of accessory subunit LYRM6 for the function of eukaryotic complex I and offer clues on its redox-linked proton pumping mechanism. Respiratory complex I plays a key role in energy metabolism. Cryo-EM structure of a mutant accessory subunit LYRM6 from the yeast Yarrowia lipolytica and molecular dynamics simulations reveal conformational changes at the interface between LYRM6 and subunit ND3, propagated further into the complex. These findings offer insight into the mechanism of proton pumping by respiratory complex I.Peer reviewe
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