981 resultados para Propeller Jets, Scour, Ports, Dock and Harbours, Hydraulics
Resumo:
Les mouvements nationalistes flamands et qubcois divergent en concernant leur structure; par exemple le nationalisme flamand s'est dvelopp comme un mouvement chrtien-dmocrate, alors que le nationalisme qubcois contemporain sest galvanis autour d'une idologie laque de gauche. Par ailleurs, il existe un contraste entre les poids sociodmographique, politique et conomique ports par la rgion de Flandres en Belgique, et ceux ports dans la province du Qubec au Canada. Cependant, malgr les influences divergentes structurelles et systmiques, les mouvements nationalistes flamand et qubcois ont dvelopp et maintenu des profils trs similaires. Par exemple, les deux mouvements nationalistes se dfinissent par une distinction ethnolinguistique, les deux ont un discours nationaliste parallle ax sur la ncessit de prserver et de protger la langue et la culture de la communaut nationale, et les deux se concentrent sur l'obtention d'une redistribution des pouvoirs culturels et politiques. Dans ce mmoire, nous proposons que le profil nationaliste ressemblant du mouvement nationaliste flamand et qubcois puisse tre expliqu par le dveloppement d'un nationalisme ethnolinguistique de contestation , qui tait initialement mis en place par les nationalistes flamands et qubcois cherchant corriger les effets d'une division culturelle du travail . Ce sentiment dun nationalisme de contestation ethnolinguistique est instrumentalis et perptu par les nationalistes flamands et qubcois en voquant certains souvenirs partags , qui sont trouvs dans le rcit historique de la communaut nationale. Ces souvenirs partags, ainsi que leurs reprsentations symboliques, refltent les sentiments de protestation, injustice et victimisation, qui sont vitaux pour les nationalistes flamands et qubcois dans le maintien de leur expression paralllement un nationalisme de contestation ethnolinguistique en Flandres et au Qubec.
Resumo:
Dock1 (aussi nomm Dock180) est le membre prototypique de la famille Dock dactivateurs des petites GTPases de la famille Rho. Dock1 agit au sein dune voie de signalisation conserve au cours de lvolution et des tudes gntiques ont dmontr que les orthologues de Dock1, myoblast city (mbc) chez la drosophile et Ced-5 chez le nmatode, activent Rac dans divers processus biologiques. Notamment, mbc est un important rgulateur de la fusion des myoblastes lors de la formation des fibres musculaires de drosophile. Mbc est aussi essentiel la migration collective dun groupe de cellules, appeles cellules de bordures, lors de leur migration dans la chambre de loeuf suite lactivation de rcepteurs activit tyrosine kinase (RTK). La migration collective des cellules de bordures rcapitule certains des vnements observs lorsque des cellules tumorales envahissent le tissu environnant lors de la formation de mtastases. Chez les mammifres, des tudes ralises en lignes cellulaires suggrent que Dock1 est aussi un rgulateur du cytosquelette lors de la migration cellulaire. De plus, certaines tudes ont dmontr que la voie Dock1/Rac agit en aval de RTKs lors de linvasion de cellules de glioblastome. Nanmoins, les fonctions in vivo de Dock1 chez les mammifres demeurent mconnues et le but de cette thse est didentifier et de caractriser certaines de ses fonctions. Guids par la fonction de mbc, nous dmontrons dans lobjectif no 1 un rle essentiel pour ce gne au cours du dveloppement embryonnaire grce la caractrisation dune souris Dock1 knock-out. Des dfauts svres de fusion des myoblastes sont observs en absence de lexpression de Dock1 et ils contribuent la rduction de la masse musculaire des souris mutantes. De plus, nous avons constat une contribution du gne Dock5, un membre de la famille Dock proche de Dock1, au dveloppement des fibres musculaires. Dans lobjectif no 2, nous avons observ que des hauts niveaux dexpression de DOCK1 corrlent avec un mauvais pronostic chez les patientes atteintes de cancer du sein possdant une forte expression du gne codant pour le RTK HER2. Une surexpression ou une amplification du locus codant pour le rcepteur HER2 est associe prs de 20% des cas de cancer du sein. Les cancers de ces patientes dveloppent frquemment des mtastases et sont associs un mauvais pronostic. Des tudes biochimiques ont rvl que DOCK1 interagit avec le rcepteur HER2 dans des cellules de cancer du sein. De plus, DOCK1 est essentiel lactivation de RAC et la migration cellulaire induite par HER2 dans ces cellules. Lutilisation dun modle de cancer du sein mdi par HER2 chez la souris combin avec linactivation du gne Dock1 dans les glandes mammaires, nous a permis didentifier Dock1 et Rac comme de nouveaux effecteurs de la croissance tumorale et de la formation de mtastases rgules par loncogne HER2. Nous concluons que lutilisation de diffrents modles de souris knock-out pour le gne Dock1 nous a permis didentifier des fonctions cls de ce gne. Tout comme son orthologue mbc, Dock1 joue un rle important lors du dveloppement embryonnaire en rgulant notamment la fusion des myoblastes. Nos tudes ont galement contribu dmontrer un important degr de conservation des mcanismes molculaires de fusion entre les espces. De plus, DOCK1 agit en aval du RTK HER2 et son expression dans les cellules pithliales de glandes mammaires contribue au dveloppement tumoral et la formation de mtastases induits par cet oncogne.
Resumo:
Lvolution rcente des commutateurs de slection de longueurs donde (WSS -Wavelength Selective Switch) favorise le dveloppement du multiplexeur optique dinsertionextraction reconfigurable (ROADM - Reconfigurable Optical Add/Drop Multiplexers) plusieurs degrs sans orientation ni coloration, considr comme un quipement fort prometteur pour les rseaux maills du futur relativement au multiplexage en longueur donde (WDM -Wavelength Division Multiplexing ). Cependant, leur proprit de commutation asymtrique complique la question de lacheminement et de lattribution des longueur dondes (RWA - Routing andWavelength Assignment). Or la plupart des algorithmes de RWA existants ne tiennent pas compte de cette proprit dasymtrie. Linterruption des services cause par des dfauts dquipements sur les chemins optiques (rsultat provenant de la rsolution du problme RWA) a pour consquence la perte dune grande quantit de donnes. Les recherches deviennent ainsi incontournables afin dassurer la survie fonctionnelle des rseaux optiques, savoir, le maintien des services, en particulier en cas de pannes dquipement. La plupart des publications antrieures portaient particulirement sur lutilisation dun systme de protection permettant de garantir le reroutage du trafic en cas dun dfaut dun lien. Cependant, la conception de la protection contre le dfaut dun lien ne savre pas toujours suffisante en termes de survie des rseaux WDM partir de nombreux cas des autres types de pannes devenant courant de nos jours, tels que les bris dquipements, les pannes de deux ou trois liens, etc. En outre, il y a des dfis considrables pour protger les grands rseaux optiques multidomaines composs de rseaux associs un domaine simple, interconnects par des liens interdomaines, o les dtails topologiques internes dun domaine ne sont gnralement pas partags lextrieur. La prsente thse a pour objectif de proposer des modles doptimisation de grande taille et des solutions aux problmes mentionns ci-dessus. Ces modles-ci permettent de gnrer des solutions optimales ou quasi-optimales avec des carts doptimalit mathmatiquement prouve. Pour ce faire, nous avons recours la technique de gnration de colonnes afin de rsoudre les problmes inhrents la programmation linaire de grande envergure. Concernant la question de lapprovisionnement dans les rseaux optiques, nous proposons un nouveau modle de programmation linaire en nombres entiers (ILP - Integer Linear Programming) au problme RWA afin de maximiser le nombre de requtes acceptes (GoS - Grade of Service). Le modle rsultant constitue celui de loptimisation dun ILP de grande taille, ce qui permet dobtenir la solution exacte des instances RWA assez grandes, en supposant que tous les noeuds soient asymtriques et accompagns dune matrice de connectivit de commutation donne. Ensuite, nous modifions le modle et proposons une solution au problme RWA afin de trouver la meilleure matrice de commutation pour un nombre donn de ports et de connexions de commutation, tout en satisfaisant/maximisant la qualit dcoulement du trafic GoS. Relativement la protection des rseaux dun domaine simple, nous proposons des solutions favorisant la protection contre les pannes multiples. En effet, nous dveloppons la protection dun rseau dun domaine simple contre des pannes multiples, en utilisant les p-cycles de protection avec un chemin indpendant des pannes (FIPP - Failure Independent Path Protecting) et de la protection avec un chemin dpendant des pannes (FDPP - Failure Dependent Path-Protecting). Nous proposons ensuite une nouvelle formulation en termes de modles de flots pour les p-cycles FDPP soumis des pannes multiples. Le nouveau modle soulve un problme de taille, qui a un nombre exponentiel de contraintes en raison de certaines contraintes dlimination de sous-tour. Par consquent, afin de rsoudre efficacement ce problme, on examine : (i) une dcomposition hirarchique du problme auxiliaire dans le modle de dcomposition, (ii) des heuristiques pour grer efficacement le grand nombre de contraintes. propos de la protection dans les rseaux multidomaines, nous proposons des systmes de protection contre les pannes dun lien. Tout dabord, un modle doptimisation est propos pour un systme de protection centralise, en supposant que la gestion du rseau soit au courant de tous les dtails des topologies physiques des domaines. Nous proposons ensuite un modle distribu de loptimisation de la protection dans les rseaux optiques multidomaines, une formulation beaucoup plus raliste car elle est base sur lhypothse dune gestion de rseau distribu. Ensuite, nous ajoutons une bande pasiv sante partage afin de rduire le cot de la protection. Plus prcisment, la bande passante de chaque lien intra-domaine est partage entre les p-cycles FIPP et les p-cycles dans une premire tude, puis entre les chemins pour lien/chemin de protection dans une deuxime tude. Enfin, nous recommandons des stratgies parallles aux solutions de grands rseaux optiques multidomaines. Les rsultats de ltude permettent dlaborer une conception efficace dun systme de protection pour un trs large rseau multidomaine (45 domaines), le plus large examin dans la littrature, avec un systme la fois centralis et distribu.
Resumo:
A dual-port dual-polarized compact microstrip antenna for avoiding cross coupling between the two frequency bands is proposed and analyzed. This antenna offers channel isolation better than 25 dB, and is more compact compared to a conventional rectangular patch. Analytical equations for calculating the resonant frequencies at both ports are also presented. The theoretical calculations are verified using experimental results
Resumo:
Data centre is a centralized repository,either physical or virtual,for the storage,management and dissemination of data and information organized around a particular body and nerve centre of the present IT revolution.Data centre are expected to serve uniinterruptedly round the year enabling them to perform their functions,it consumes enormous energy in the present scenario.Tremendous growth in the demand from IT Industry made it customary to develop newer technologies for the better operation of data centre.Energy conservation activities in data centre mainly concentrate on the air conditioning system since it is the major mechanical sub-system which consumes considerable share of the total power consumption of the data centre.The data centre energy matrix is best represented by power utilization efficiency(PUE),which is defined as the ratio of the total facility power to the IT equipment power.Its value will be greater than one and a large value of PUE indicates that the sub-systems draw more power from the facility and the performance of the data will be poor from the stand point of energy conservation. PUE values of 1.4 to 1.6 are acievable by proper design and management techniques.Optimizing the air conditioning systems brings enormous opportunity in bringing down the PUE value.The air conditioning system can be optimized by two approaches namely,thermal management and air flow management.thermal management systems are now introduced by some companies but they are highly sophisticated and costly and do not catch much attention in the thumb rules.
Resumo:
This thesis Entitled Marine actinomycetes as source of antimicrobial compounds and as probiotics and single cell protein for application in penaeid peawn culture systems. Ocean harbours more than 80% of all life on earth and remains our greatest untapped natural resource. The study revealed the potential of marine actinomycetes as a source of antimicrobial compounds. The selected streptomycetes were found to be capable of inhibiting most of the pathogenic vibrios, whichis a major problem both in hatcheries and grow out systems. The bioactive principle can be incorporated with commercial feeds and applied as medicated diet for the control of vibrios in culture systems.The hydrolytic potential inhibitory property against pathogens and nonpathogenicity to penaeid prawns make the selected Streptomycesspp.an effective probioic in aquaculture. Since there is considerably less inhibition to the natural in pond ecosystem the microbial diversityis being maintained and thereby the water quality. Actinomycetes was found to be a good source of single cell protein as an ingredient inaquaculture feed formulations. Large amount of mycelial waste (actinomycete biomassO is produced from antibiotic industries and this nutrient rich waste can be effectively used as a protein source in aquaculture feeds.This study reveals the importance of marine actinomycetes as a source of antimicrobial compounds and as a probiotic and single cell protein for aquaculture applications.
Resumo:
This work identifies the importance of plenum pressure on the performance of the data centre. The present methodology followed in the industry considers the pressure drop across the tile as a dependant variable, but it is shown in this work that this is the only one independent variable that is responsible for the entire flow dynamics in the data centre, and any design or assessment procedure must consider the pressure difference across the tile as the primary independent variable. This concept is further explained by the studies on the effect of dampers on the flow characteristics. The dampers have found to introduce an additional pressure drop there by reducing the effective pressure drop across the tile. The effect of damper is to change the flow both in quantitative and qualitative aspects. But the effect of damper on the flow in the quantitative aspect is only considered while using the damper as an aid for capacity control. Results from the present study suggest that the use of dampers must be avoided in data centre and well designed tiles which give required flow rates must be used in the appropriate locations. In the present study the effect of hot air recirculation is studied with suitable assumptions. It identifies that, the pressure drop across the tile is a dominant parameter which governs the recirculation. The rack suction pressure of the hardware along with the pressure drop across the tile determines the point of recirculation in the cold aisle. The positioning of hardware in the racks play an important role in controlling the recirculation point. The present study is thus helpful in the design of data centre air flow, based on the theory of jets. The air flow can be modelled both quantitatively and qualitatively based on the results.
Resumo:
In the present study the effect of hot air recirculation is studied with suitable assumptions. It identifies that, the pressure drop across the tile is a dominant parameter which governs the recirculation. The rack suction pressure of the hardware along with the pressure drop across the tile determines the point of recirculation in the cold aisle. The positioning of hardware in the racks play an important role in controlling the recirculation point. The present study is thus helpful in the design of data centre air flow, based on the theory of jets. The air flow can be modelled both quantitatively and qualitatively based on the results
Resumo:
The present investigation has looked exclusively into the aspect of the biological phenomenon of settling behaviour by two serious fouling offenders encountered in the tropical seas mainly on the hulls of ships and stationary structures in the harbours. The cue to study the behaviour was adopted from the observations so far made by scientists on the epizoic growth of these organisms on the surfaces of algal fronds of variegated shape, texture, size etc. The results do indicate that there are sufficient qualities of bioactive substances produced by plants occupying the lowest categories in organic evolution and curiously enough these substances have withstood the test of time.
Resumo:
Tsunamis are water waves generated by a sudden vertical displacement of the water surface. They are waves generated in the ocean by the disturbance associated with seismic activity, under sea volcanic eruptions, submarine landslides, nuclear explosion or meteorite impacts with the ocean. These waves are generated in the ocean and travel into coastal bays, gulfs, estuaries and rivers. These waves travel as gravity waves with a velocity dependent on water depth. The term tsunami is Japanese and means harbour (tsu) and wave (nami). It has been named so because such waves often develop resonant phenomena in harbours after offshore earthquakes.
Resumo:
Developments in laser technology over the past few years have made it possible to do experiments with focused intensities of IO"-102' Wcm'z. Short-pulse high-intensity lasers are able to accelerate protons and heavier ions to multi-MeV energies during their interaction with solid targets, gas jets and clusters. When such a laser radiation is focused at the intensity above 10 Wcm'2, local electric field strength will be almost equivalent to that within an atom. Hence, new nonlinear optical phenomena will be expected in the field of light matter interaction. Most of the research in the material interaction using high power lasers, especially related to plasma interaction, has been directed to the short pulse x-ray generation- Nanosecond laser interactions with solid targets also generate plasmas which emit radiation mainly in the optical region, the understanding of which is far from satisfactory. This thesis deals with a detailed study of some of the dynamical processes in plasmas generated by nanosecond and femtosecond lasers
Resumo:
Maritime ports are inevitable for Indias economic development. The very existence and sustainable development of ports depend on clean port environment. There is a notion that shipping is an over regulated industry. But in India, it is being operated under sub- standard conditions, raising crucial issues of environmental pollution in the countrys ports. The negative impacts of vessel sourced pollution on the eco-fragile coastal peninsula can be detrimental to the living conditions, health and interests of the coastal population. It can disturb marine life and imbalance the aquatic ecosystem. The present study analyses control of vessel sourced pollution in Indian ports from an economic and ecological perspective. The study investigates legal reasons behind the weak control, regulation and monitoring over vessel sourced pollution in Indian ports. The loopholes in the legal system are identified and suggestion made to implement stronger enforcement. Unless, vessel operations are properly regulated in ports, the trade and economic prospects of India will be jeopardized.
Resumo:
The resurgence of the enteric pathogen Vibrio cholerae, the causative organism of epidemic cholera, remains a major health problem in many developing countries like India. The southern Indian state of Kerala is endemic to cholera. The outbreaks of cholera follow a seasonal pattern in regions of endemicity. Marine aquaculture settings and mangrove environments of Kerala serve as reservoirs for V. cholerae. The non-O1/non-O139 environmental isolates of V. cholerae with incomplete virulence casette are to be dealt with caution as they constitute a major reservoir of diverse virulence genes in the marine environment and play a crucial role in pathogenicity and horizontal gene transfer. The genes coding cholera toxin are borne on, and can be infectiously transmitted by CTX, a filamentous lysogenic vibriophages. Temperate phages can provide crucial virulence and fitness factors affecting cell metabolism, bacterial adhesion, colonization, immunity, antibiotic resistance and serum resistance. The present study was an attempt to screen the marine environments like aquafarms and mangroves of coastal areas of Alappuzha and Cochin, Kerala for the presence of lysogenic V. cholerae, to study their pathogenicity and also gene transfer potential. Phenotypic and molecular methods were used for identification of isolates as V. cholerae. The thirty one isolates which were Gram negative, oxidase positive, fermentative, with or without gas production on MOF media and which showed yellow coloured colonies on TCBS (Thiosulfate Citrate Bile salt Sucrose) agar were segregated as vibrios. Twenty two environmental V. cholerae strains of both O1 and non- O1/non-O139 serogroups on induction with mitomycin C showed the presence of lysogenic phages. They produced characteristic turbid plaques in double agar overlay assay using the indicator strain V. cholerae El Tor MAK 757. PCR based molecular typing with primers targeting specific conserved sequences in the bacterial genome, demonstrated genetic diversity among these lysogen containing non-O1 V. cholerae . Polymerase chain reaction was also employed as a rapid screening method to verify the presence of 9 virulence genes namely, ctxA, ctxB, ace, hlyA, toxR, zot,tcpA, ninT and nanH, using gene specific primers. The presence of tcpA gene in ALPVC3 was alarming, as it indicates the possibility of an epidemic by accepting the cholera. Differential induction studies used ALPVC3, ALPVC11, ALPVC12 and EKM14, underlining the possibility of prophage induction in natural ecosystems, due to abiotic factors like antibiotics, pollutants, temperature and UV. The efficiency of induction of prophages varied considerably in response to the different induction agents. The growth curve of lysogenic V. cholerae used in the study drastically varied in the presence of strong prophage inducers like antibiotics and UV. Bacterial cell lysis was directly proportional to increase in phage number due to induction. Morphological characterization of vibriophages by Transmission Electron Microscopy revealed hexagonal heads for all the four phages. Vibriophage ALPVC3 exhibited isometric and contractile tails characteristic of family Myoviridae, while phages ALPVC11 and ALPVC12 demonstrated the typical hexagonal head and non-contractile tail of family Siphoviridae. EKM14, the podophage was distinguished by short non-contractile tail and icosahedral head. This work demonstrated that environmental parameters can influence the viability and cell adsorption rates of V. cholerae phages. Adsorption studies showed 100% adsorption of ALPVC3 ALPVC11, ALPVC12 and EKM14 after 25, 30, 40 and 35 minutes respectively. Exposure to high temperatures ranging from 50C to 100C drastically reduced phage viability. The optimum concentration of NaCl required for survival of vibriophages except EKM14 was 0.5 M and that for EKM14 was 1M NaCl. Survival of phage particles was maximum at pH 7-8. V. cholerae is assumed to have existed long before their human host and so the pathogenic clones may have evolved from aquatic forms which later colonized the human intestine by progressive acquisition of genes. This is supported by the fact that the vast majority of V. cholerae strains are still part of the natural aquatic environment. CTX has played a critical role in the evolution of the pathogenicity of V. cholerae as it can transmit the ctxAB gene. The unusual transformation of V. cholerae strains associated with epidemics and the emergence of V. cholera O139 demonstrates the evolutionary success of the organism in attaining greater fitness. Genetic changes in pathogenic V. cholerae constitute a natural process for developing immunity within an endemically infected population. The alternative hosts and lysogenic environmental V. cholerae strains may potentially act as cofactors in promoting cholera phage blooms within aquatic environments, thereby influencing transmission of phage sensitive, pathogenic V. cholerae strains by aquatic vehicles. Differential induction of the phages is a clear indication of the impact of environmental pollution and global changes on phage induction. The development of molecular biology techniques offered an accessible gateway for investigating the molecular events leading to genetic diversity in the marine environment. Using nucleic acids as targets, the methods of fingerprinting like ERIC PCR and BOX PCR, revealed that the marine environment harbours potentially pathogenic group of bacteria with genetic diversity. The distribution of virulence associated genes in the environmental isolates of V. cholerae provides tangible material for further investigation. Nucleotide and protein sequence analysis alongwith protein structure prediction aids in better understanding of the variation inalleles of same gene in different ecological niche and its impact on the protein structure for attaining greater fitness of pathogens. The evidences of the co-evolution of virulence genes in toxigenic V. cholerae O1 from different lineages of environmental non-O1 strains is alarming. Transduction studies would indicate that the phenomenon of acquisition of these virulence genes by lateral gene transfer, although rare, is not quite uncommon amongst non-O1/non-O139 V. cholerae and it has a key role in diversification. All these considerations justify the need for an integrated approach towards the development of an effective surveillance system to monitor evolution of V. cholerae strains with epidemic potential. Results presented in this study, if considered together with the mechanism proposed as above, would strongly suggest that the bacteriophage also intervenes as a variable in shaping the cholera bacterium, which cannot be ignored and hinting at imminent future epidemics.
Resumo:
The Sultanate of Oman is located on the south-eastern coast of the Arabian Peninsula, which lies on the south-western tip of the Asian continent. The strategic geographical locations of the Sultanate with its many maritime ports distributed on the Indian Ocean have historically made it one of the Arabian Peninsula leaders in the international maritime trade sector. Intensive trading relationships over long time periods have contributed to the high plant diversity seen in Oman where agricultural production depends entirely on irrigation from groundwater sources. As a consequence of the expansion of the irrigated area, groundwater depletion has increased, leading to the intrusion of seawater into freshwater aquifers. This phenomenon has caused water and soil salinity problems in large parts of the Al-Batinah governorate of Oman and threatens cultivated crops, including banana (Musa spp.). According to the Ministry of Agriculture and Fisheries, the majority of South Al-Batinah farms are affected by salinity (ECe > 4 dS m-1). As no alternative farmland is available, the reclamation of salt-affected soils using simple cultural practices is of paramount importance, but in Oman little scientific research has been conducted to develop such methods of reclamation. This doctoral study was initiated to help filling this research gap, particularly for bananas. A literature review of the banana cultivation history revealed that the banana germplasm on the Arabian Peninsula is probably introduced from Indonesia and India via maritime routes across the Indian Ocean and the Red Sea. In a second part of this dissertation, two experiments are described. A laboratory trial conducted at the University of Kassel, in Witzenhausen, Germany from June to July 2010. This incubation experiment was done to explore how C and N mineralization of composted dairy manure and date palm straw differed in alkaline non-saline and saline soils. Each soil was amended with four organic fertilizers: 1) composted dairy manure, 2) manure + 10% date palm straw, 3) manure + 30% date palm straw or 4) date palm straw alone, in addition to un-amended soils as control. The results showed that the saline soil had a lower soil organic C content and microbial biomass C than the non-saline soil. This led to lower mineralization rates of manure and date palm straw in the saline soil. In the non-saline soil, the application of manure and straw resulted in significant increases of CO2 emissions, equivalent to 2.5 and 30% of the added C, respectively. In the non-amended control treatment of the saline soil, the sum of CO2-C reached only 55% of the soil organic C in comparison with the non-saline soil. In which 66% of the added manure and 75% of the added straw were emitted, assuming that no interactions occurred between soil organic C, manure C and straw C during microbial decomposition. The application of straw always led to a net N immobilization compared to the control. Salinity had no specific effect on N mineralization as indicated by the CO2-C to Nmin ratio of soil organic matter and manure. However, N immobilization was markedly stronger in the saline soil. Date palm straw strongly promoted saprotrophic fungi in contrast to manure and the combined application of manure and date palm straw had synergistic positive effects on soil microorganisms. In the last week of incubation, net-N mineralization was observed in nearly all treatments. The strongest increase in microbial biomass C was observed in the manure + straw treatment. In both soils, manure had no effect on the fungi-specific membrane component ergosterol. In contrast, the application of straw resulted in strong increases of the ergosterol content. A field experiment was conducted on two adjacent fields at the Agricultural Research Station, Rumais (234115 N, 57591 E) in the South of Al-Batinah Plain in Oman from October 2007 to July 2009. In this experiment, the effects of 24 soil and fertilizer treatments on the growth and productivity of Musa AAA cv. 'Malindi' were evaluated. The treatments consisted of two soil types (saline and amended non-saline), two fertilizer application methods (mixed and ring applied), six fertilizer amendments (1: fresh dairy manure, 2: composted dairy manure, 3: composted dairy manure and 10% date palm straw, 4: composted dairy manure and 30% date palm straw, 5: only NPK, and 6: NPK and micronutrients). Sandy loam soil was imported from another part of Oman to amended the soil in the planting holes and create non-saline conditions in the root-zone. The results indicate that replacing the saline soil in the root zone by non-saline soil improved plant growth and yield more than fertilizer amendments or application methods. Particularly those plants on amended soil where NPK was applied using the ring method and which received micronutrients grew significantly faster to harvest (339 days), had a higher average bunch weight (9.5 kg/bunch) and were consequently more productive (10.6 tonnes/hectare/cycle) compared to the other treatments.
Resumo:
Monty, el perro con gafas est siempre dispuesto a echar una pata una ayuda a su familia. Lo mismo suplanta a un osito de peluche en una tarta de cumpleaos que hace de portero en un partido de ftbol.
