107 research outputs found
Genetic diversity based on SSR markers, heterosis and yield performance of Brassica rapa for biomass production
Die Erzeugung von Biogas gewinnt in Europa
zunehmend an Bedeutung. Als Substrat dienen dabei ĂŒberwiegend
Energiepflanzen, und zur Zeit werden etwa 2% der
landwirtschaftlichen FlĂ€che in Deutschland fĂŒr den Anbau von
Pflanzen zur Biogaserzeugung verwendet. Etwa 80 % davon ist Mais,
eine ursprĂŒnglich subtropische Pflanze mit niedriger KĂŒhletoleranz,
die erst Ende April gesÀt werden kann. Zur Erzeugung hoher
BiomasseertrÀge ist es daher sinnvoll, den Anbau von Mais oder
anderer wÀrmeliebender Arten wie Hirse oder Sonnenblume zu
kombinieren mit dem Anbau von Arten mit hoher Biomasseproduktion
auch unter niedrigen Temperaturen wie Getreidearten, GrÀsern, oder
Brassica-Arten. So können zwei Kulturen in einer Saison angebaut
werden: die erste wird im Herbst gesĂ€t und im FrĂŒhjahr geerntet,
und die zweite wird anschlieĂend im FrĂŒhjahr gesĂ€t und im Herbst
geerntet.
RĂŒbsen (Brassica rapa) ist eine traditionelle Ălfrucht in Mittel-
und Nordeuropa, aber ihr Anbau ist heute nahezu erloschen.
Allerdings gibt es ein erneutes Interesse am Anbau von B. rapa in
Europa zur Erzeugung von Biomasse, da es kaum eine andere Fruchtart
mit Àhnlich hohen Wachstumsraten unter niedrigen Temperaturen im
zeitigen FrĂŒhjahr gibt. Die Entwicklung von Zuchtprogrammen fĂŒr B.
rapa zur Erzeugung von Biomasse erfordert aber eine bessere
Kenntnis der genetischen Variation im europÀischen Genpool dieser
Art.
Bisher hat sich die ZĂŒchtung von RĂŒbsen vor allem auf die
Verbesserung der QualitĂ€t fĂŒr die menschliche ErnĂ€hrung oder zur
Verwendung als Futtermittel konzentriert, wofĂŒr die
ErucasÀurefreiheit und ein niedriger Glucosinolatgehalt von
Bedeutung sind. Diese Zuchtziele unterscheiden sich stark von den
Anforderungen an eine Sorte fĂŒr die Biogaserzeugung. Die
QualitĂ€tszĂŒchtung hat dazu gefĂŒhrt, dass das Zuchtmaterial fĂŒr
heutige Sorten zweimal durch eine genetischen âFlaschenhalsâ gehen
musste, wodurch möglicherweise die genetische Variation reduziert
wurde. Daher ist es von Interesse, auch das Potential Àlterer
Sorten zu untersuchen.Diese Arbeit hatte die folgenden
Zielsetzungen: (1) die Entwicklung einer ZĂŒchtungsstrategie fĂŒr B.
rapa zur Biogaserzeugung unter besonderer BerĂŒcksichtigung von
Kombinationseignung und Heterosis; (2) die Bestimmung von
Biomasseertrag und Heterosis in Kreuzungen innerhalb und zwischen
EuropĂ€ischen RĂŒbsensorten.; (3) die Untersuchung des Einflusses der
QualitĂ€tszĂŒchtung auf die genetische DiversitĂ€t mit Hilfe von
molekularen Markern.
Zur Untersuchung von Kombinationseignung und Heterosis wurden 15
europĂ€ische WinterrĂŒbsensorten verwendet. Durch diallele
Durchkreuzung dieser Elternsorten wurden 105 Keuzungskombinationen
erzeugt. Die Eltern und ihren Kreuzungen wurden in einer
Gitteranlage mit zwei Wiederholungen in zwei Jahren an zwei Orten
geprĂŒft. Dabei wurden die Merkmale Tage bis BlĂŒhbeginn (DTF),
Frischmasseertrag (FBY), Trockenmassegehalt (DMC) und
Trockenmasseertrag (TBY) erfasst.
Die Kreuzungen hatten gegenĂŒber ihren Eltern eine Mehrleistung von
7,6 % fĂŒr FBY und 5,9 % fĂŒr DBY. Die höchsten relativen
Heterosiswerte waren 21,0 % FBY und 30,4 % fĂŒr DBY. Die
Varianzanalyse zeigte, dass vor allem die spezifische
KombinationsfÀhigkeit (SCA) von Bedeutung war. Die Korrelation
zwischen allgemeiner KombinationsfÀhigkeit (GCA) und Elternleistung
betrug 0.42** fĂŒr FBY und 0,53** fĂŒr DBY. Durch eine Selektion von
Elternkombinationen mit hoher SCA fĂŒr die Herstellung synthetischer
Sorten sollte eine schnelle Steigerung der Biomasseleistung von
RĂŒbsen möglich sein.
Die Leistung synthetischer Sorten im Vergleich zu
Vollgeschwister-Nachkommenschaften innerhalb bzw. zwischen Sorten
wurde an drei europĂ€ischen WinterrĂŒbsensorten nĂ€her untersucht. Die
Vollgeschwister ĂŒbertrafen die Leistung der Eltern in den meisten
Merkmalen. Die Vollgeschwister aus Kreuzungen zwischen Sorten
hatten einen signifikant höheren Frisch- und Trockenmasseertrag als
die Vollgeschwister aus Kreuzungen innerhalb der Sorten.
Die Heterosis der Vollgeschwister zwischen Sorten im Vergleich zu
den Vollgeschwistern innerhalb Sorten betrug 9,2 % fĂŒr DBY, 4,4 %
fĂŒr FBY, und 3,0 % fĂŒr DMC. Die Korrelation zwischen DBY betrug FBY
war 0,61** und die zwischen DBY und DMC 0,86**. Insgesamt gesehen
war die Heterosis relativ gering, was darauf hinweist, dass die
untersuchten Elternsorten eine geringe DiversitÀt hatten.
Um zu untersuchen, ob die ZĂŒchtung zu einer Einengung der
genetischen DiversitĂ€t gefĂŒhrt hat, wurden drei unterschiedlich
alte Sorten verglichen, die verschiedene ZĂŒchtungsperioden
reprÀsentieren. Ihre DiversitÀt wurden an je 32 Pflanzen mit Hilfe
von Mikrosatelliten (SSR) untersucht, die alle Kopplungsgruppen des
Genoms abdecken. Es wurde nur eine sehr leichte, nicht signifikante
Abnahme der DiversitÀt beobachtet, gemessen an der Allelanzahl, dem
Informationsindex, und der erwarteten Heterozygotie. Die
QualitĂ€tszĂŒchtung hat daher bei RĂŒbsen kaum zu einem Verlust an
genetischer Variation gefĂŒhrt.
Eine Analyse der molekularen Variation (AMOVA) zeigte, dass 83 %
der genetischen Variation innerhalb der Sorten und nur 17 %
zwischen den Sorten auftrat. Einzelpflanzen der drei Sorten wurden
durch Hauptkoordinatenanalyse sowie durch ein Dendrogram aua einer
Clusteranalyse charakterisiert. Auch hier zeigte sich, dass die
genetische Variation vor allem innerhalb der Sorten auftrat,
wodurch sich der relativ geringe Heterosiszuwachs in Kreuzungen
zwischen Sorten erklÀren lÀsst. Dennoch trat bei einigen
Kombinationen eine deutliche Heterosis auf, die sich zur Steigerung
der Biomasseleistung relativ einfach durch die Entwicklung von
synthetischen Sorten nutzen lÀsst
Biocatalytic cascades involving LmrR-based artificial enzyme
A key challenge of integrating non-natural catalytic residues into proteins to design artificial enzymes for novel reactions lies in achieving in vivo reactivity due to issues such as metal cofactor toxicity and catalyst susceptibility to the biological milieu. Proposed solutions include compartmentalization strategies and incorporation of non-natural amino acids as catalytic moieties within biomolecular scaffolds.To address this challenge of in vivo reactivity, this thesis is dedicated to the integration of specific unnatural amino acids. The results promise insights into the potential of hybrid enzymatic approaches to revolutionize biocatalysis for emerging applications.This includes integrating para-amino-phenylalanine (pAF), an unnatural amino acid, into the LmrR protein. The modified protein functions as an artificial enzyme for cascade reactions, resulting in successful in vivo hydrazone formation. By coupling natural enzyme pathways with engineered LmrR-pAF, the study demonstrates intricate cascade catalysis, enabling biosynthesis of aromatic aldehydes.Expanding the investigation, the research navigates complex reactions, exemplified by the Friedel-Crafts alkylation. Orchestrating a cascade involving artificial and natural enzymes, the study achieves controlled chemical product formation in vitro. While challenges remain for in vivo translation, the study identifies areas for refinement.Furthermore, the study explores creating novel artificial enzymes by introducing non-canonical amino acids (N-Methyl Histidine and 3-Pyridyl Alanine) into the LmrR scaffold. Catalytic activity is successfully demonstrated in ester hydrolysis, with future trajectories including intricate chemical transformations.In summary, this research pioneers hybrid enzyme systems, propelling the development of novel metabolic pathways in living cells
Morphing Wings Using Macro Fiber Composites
Macro Fiber Composites (MFC) are smart materials that have one or more properties that can be altered by an external stimulus such as magnetic and electric fields, temperature and pH, in order to meet specific requirements or conditions. Today, smart materials are used in a variety of applications in the aerospace industry, locomotives, and in the medical field to generate better performance for its devices. The objective of this paper is to describe an experiment on morphing a wing using MFCs. The materials needed to achieve this project are illustrated in the experimental setup of this paper. Additionally, the author expects to be able to morph the wing of the aircraft and compare its acquired data to that of a general aircraft to determine which one has the best performance
Enhancing service quality in the maritime industry : a case study of Tema Port
This dissertation is an analysis of service quality in the maritime industry with emphasis on enhancing service quality in Tema Port in Ghana. A general overview of service quality is examined at the beginning of the study. This is further narrowed down to service quality amongst the various service providers in the maritime industry with specific focus on those operating in Tema Port. To gain a holistic understanding of the existing service quality in Tema Port and how it can be enhanced: the study, obtained information from shippers/freight forwarders and leading executives in the maritime industry in Ghana, from operational and managerial perspectives. The study revealed that, on a whole, service quality in Tema Port was at best average. Thus for it to be enhanced, the industry had to adopt a mix of both short and long term seaside and shore-side solutions. This study helps to provide an informative and well-rounded view of service quality in Tema Port. The study also brings together the various fragmented writings on improving service quality in Tema Port. It also demonstrates how service quality is assessed in the maritime industry and how the recurrent problems of port congestion, lack of equipment, delays in the clearance of goods, poor customer services, uncapped shipping agency charges, allegations of bribery and corruption and lack of innovation bedeviling service providers in Tema Port can be tackled. Additionally, it shows how the Ghanaian maritime industry can be positioned as a model of excellence in West Africa and beyond
Weak Diffusive Stability of Roll Solutions at the Zigzag Boundary
Roll solutions at the zigzag boundary, typically selected by patterns and
defects in numerical simulations, are shown to be nonlinearly stable. This
result also serves as an example that linear decay weaker than the classical
diffusive decay, together with quadratic nonlinearity, still gives nonlinear
stability of spatially periodic patterns. Linear analysis reveals that, instead
of the classical diffusive decay rate, small perturbations of roll
solutions at the zigzag boundary decay with a rate along with time,
due to the degeneracy of the quadratic term of the continuation of the
translational mode of the linearized operator in the Bloch-Fourier spaces. The
nonlinear stability proof is based on a decomposition of the neutral
translational mode and the faster decaying modes in the Bloch-Fourier space,
and a fixed-point argument, demonstrating the irrelevancy of the nonlinear
terms.Comment: 54 pages, 1 figur
Financial development, remittances and economic growth: A threshold analysis
Sources of economic growth in Ghana have not been clear. Several
studies have contributed to the finance and growth literature with little
attention on remittances and the joint effect of financial sector development and remittances. This paper uses macrodata to examine the linkages between financial development, remittances and economic growth in Ghana. We estimate a dynamic heterogeneous Autoregressive Distributed Lag (ARDL) model to show that financial booms are not, in general, growth-enhancing, and a certain level of financial development can drag down economic growth in the long term and the combined effect of financial development and remittances
should be of concern to policymakers
The Relevance of Accounting Information in the Management of Small Scale Businesses in the Yilo Krobo District in Ghana
The aim of the study is to examine the relevance of accounting information in the management of small-scale enterprises in the Yilo Krobo District. The motivation for this study emerged as a result of the need to highlight the importance or significance of accounting information in the planning and controlling of small scale business activities. A sample of 40 Small-scale businesses registered with the National Board for Small-Scale Industries (NBSSI) was selected. Self-administered questionnaire was used to solicit information from the respondents and the data was analyzed using tables, pie chart and graphs. The main findings of the study were that these small scale enterprises in Yilo Krobo District were found to have no accounting system. Instead, they rather had a self-designed record-keeping system which generally shows inadequate documentation of transactions or financial records. The records kept by these small scale business operators were often not separated from the personal affairs and accounts of owners. There was also no full time trained accounting employee or the use of external management/accounting advisor who could design and review accounting systems. It was recommended that the owners of these small-scale enterprises should engage the service of qualified accountants to improve the accounting practices such as budgets preparation, cash book recordings etc. The NBSSI should liaise with the executives of these small-scale enterprises to organize refresher courses to improve their level of competency in cash flow management. Keywords: Accounting Information, Small Scale Business, Ghan
Psychological Factors That Influence Teachersâ Perception of Head Teachersâ Leadership Styles in the Dormaa East District
The activities in the schools as well as the interactions that took place in the schools influenced teachersâ perception of head teachersâ leadership styles the most. The purpose of the study was to investigate the psychological factors that influence teachersâ perception of head teachersâ leadership styles. The study adopted an exploratory approach using a descriptive survey design. The study was carried out in 50 basic schools with a sample size of 217 teachers. The proportional random sampling method was used to select the respondents. The study showed that situation-specific factors namely; school culture, relationship with other teachers, interpersonal relationship with the head teacher, head teacher support, and GES policies being implemented influenced teachersâ perception of head teachersâ leadership styles. The study found no statistically significant difference between males and females in terms of factors influencing teachersâ perception of head teachersâ leadership style. It was recommended that the training of head teachers should include how to build healthy school culture in the schools. Keywords: Headteacher, Leadership style, Perception, Situation-Specific Factors DOI: 10.7176/JEP/13-21-08 Publication date:June 30th 202
Economic Impact of COVID-19 on Seventh-day Adventist College of Education Students in Ghana: Did the Lockdown Status of a District Matter?
This article examined the economic effects of the coronavirus disease on college of education students based on their location in the lockdown and non-lockdown districts. A total of 198 students from the Seventh-day Adventist College of Education, Agona-Ashanti, Ghana, were selected using a simple random sampling. A questionnaire and semi-structured thematic guide were used for data collection. Quantitative data analysis was performed using IBM SPSS (version 25) while direct quotes from in-depth interviews were used to support quantitative data. The results show that students and parents mainly engaged in trading and farming as their main sources of income. The chi-square test of independence showed no statistically significant differences in the self-supporting livelihood activities pursued by students from lockdown and non-lockdown districts (PË.05). It also showed no statistically significant differences in the effect of the pandemic on both parents' and students' livelihood activities based on their location (PË.05). The economic consequences of the pandemic on studentsâ academic activities in both lockdown and non-lockdown districts were, thus, similar. It is recommended that the Ghanaian government's measures to mitigate the economic effects of the pandemic should not be limited to the lockdown districts but should be extended to all districts across the country
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