This research has focused on the determination of natural populations in the fields, the effect of different inoculum densities on lettuce growth and a study of the association of this fungus with two nematodes (Pratylenchus penetrans Cobb and Meliodogyne hapla Chitwood). Under conditions of artificial infestation of soil the results were satisfactory, but in trials with naturally infested soil the fungus could not be detected. The effect of different inoculum densities was measured at different stages of growth, and only in those plants inoculated 2 weeks after seeding were differences significant and consistent. Some evidence of the detrimental effect of wounding the root system prior to attack by the fungus led to studies of the relationship between this fungus with either P. penetrans or M. hapla. In the first case a negative interaction seemed to exist; no significant increase of the damage caused to the lettuce was observed. In contrast, when the root-knot nematodes and P. tracheiphilum were combined there was a marked reduction of lettuce growth. The interaction was found to be additive.

Skandinavijos krypties aktualumas vežant krovinius iš Lietuvos per 2008-2010 m.m. itin sparčiai augo - kasmet vidutiniškai fiksuojamas 15 % еksporto srauto didėjimas. Rinkos pataruklumą įrodo jos aukšti ekonominiai rodikliai: bendrai Švedijos, Norvegijos ir Danijos - dvigubai aukštesni nei Lietuvos bei Baltijos šalių bei trečdaliu - nei Vakarų Europos. Infliacija siekia vos 2 %, nedarbo lygis svyruoja 4-6%, BVP augimas 3.4 %, pagal pasaulinį ekonomikos vertinimą minėtos trys Skandinavijos šalys patenka į penkioliktuką. Nepaisant to, šios rinkos įsisavinimo barjerai vis dar jaučiami tiek Lietuvos kelių transporto operatorių, tiek skandinavijos verslininkų. Šio magistro baigiamojo darbo tema - Skandinavijos krypties patrauklumo Lietuvos vežėjams kelių transportu tyrimas. Analizuojama problema - barjerai, trukdantys įėjimą į Skandinavijos rinką. Pirmoje darbo dalyje analizuojami Baileyss (2007), Robbins (2003), Coyle (1992), Eksportuojančiosios Lietuvos bei kitų autorių straipsniai ir apžvalgos, kurios kreipia i pagrindinius įėjimo į šią rinką barjerus: nepakankama informacija apie Lietuvos vežėjus, jų nežinomumas,rinkoje, tiesioginio kontakto prioritetas (parodų, susitikimų pas potencialius klientus metu), aukšti aplinkosauginiai ("draugiški gamtai" reikalavimai). Antrojoje darbo dalyje pasirenkamas mokslinis tyrimas, anketuojant 15 ekspertų pagal numatytus kriterijus. Analizuojama lyginamosios analizės bei rangavimo metodų svarba ir aktualumas, sudaromi anketos klausimai... [toliau žr. visą tekstą] / The relevant of Scandinavia market for carrying goods by road transport from Lithuania past years (2008-2010) was growing progresivly. Annual growth of export to Scandinavia market was fixed 15 % on average. The attractiveness of Scandinavian market identifies its indicators: 2 % of inflation, 4-6% of unemployment, GDP growth of 3.4 %. Sweden, Norway and Denmark have double higher economy than Lithuania and one third higher than West Europe. Despite this, the entrance barriers to the market are still causing issues for Lithuanian road transport operators. The thesis of this master project is Research on Scandinavian targeted direction attractiveness to Lithuanian carriers by road transport. In the first part of this project research articles by Bayless (2007), Robbins (2003), Coyle (1992), Export of Lithuania and others are being analyzed. All the articles direct to main barriers of Scandinavia market input: insufficient information about Lithuanian carriers,not very well-known in international market, lack of direct communication (during the exhibitions, visits), high environmental requirements (environmentally-friendly). In the second part of the project science research is chosen by questionnaire 15 experts.Each of the chosen expert conform required criteria s. The analysis was based on comparative and rankings analysis', identifying the importance and relevance of each criteria's. The questionnaire was made. In the third part of the project all the analysis with data was... [to full text]

Amblyomma americanum, the lone star tick, is an indigenous tick species in southern Indiana that harbors a diverse group of pathogenic and nonpathogenic microorganisms, including Borrelia lonestari, the putative agent for the southern tick associated rash illness (START) and a spotted fever group rickettsial endosymbiont. The purpose of this study was to implement the real-time polymerase chain reaction (real-time PCR) as a molecular technique to examine the microbial diversity in A. americanum ticks by estimating abundances of different microorgansisms. A SYBR Green real-time PCR assay was designed to detect and quantify B. lonestari in A. americanum ticks, and a previously published TaqMan real-time PCR assay, designed to detect (not quantify) Rickettsia species in ticks, was validated for the detection and quantification of the spotted fever group rickettsial endosymbiont in A. americanum ticks. Many pitfalls associated with real-time PCR were experienced in this study, such as difficulties in assay design and problems with contamination, and appropriate modifications are recommended to laboratories routinely performing real-time PCR. / Department of Biology

Human monocytotropic ehrlichiosis (HME) is a tick-borne infectious disease caused by the bacterium Ehrlichia chaffeensis and transmitted by the lone star tick, Amblyomma americanum. The disease was recognized in Indiana for the first time in 1994. Since 1999, 11 cases have been confirmed in Indiana and two additional cases are under investigation. In the past five years, the cases have been reported from Crawford, Harrison, Warrick, Martin, Perry, Spencer, and Madison counties.A total of 2765 adult Amblyomma americanum ticks were collected from eight counties in southern Indiana during two field trips in May 2000. Ticks were pooled and examined for the presence of Ehrlichia chaffeensis using nested PCR with primers HE1 and HE3, specific for the 16S rRNA gene of the pathogen. Ninety-six pools of A. americanum specimens tested positive for E. chaffeensis DNA. This represented a minimum infection rate (MIR) of 3.5%.To identify different genetic forms (strains) of E. chaffeensis, the positive tick pools were probed for the Variable Length PCR Target (VLPT) gene of E. chaffeensis. The data were used to develop a geographic map of the distribution of the different strains of the pathogen. Overall, nine different genetic variants (91HE17, Arkansas, Jax, Liberty, Osceola, Sapulpa, St. Vincent, Wakulla, West Paces) of E. chaffeensis were identified from pools of ticks collected in four counties (Harrison, Perry, Pike, Warrick). All samples positive for the 16S rRNA were also positive for the VLPT gene.E. chaffeensis isolates are polymorphic in the number of repetitive sequences within the genes encoding the VLPT, and the isolates obtained illustrate this phenomenon. The high concordance rate between the 16S rRNA and the VLPT gene reveals that the VLPT gene is a very sensitive tool for detecting E. chaffeensis in the lone star ticks. We found no clear correlation between geographic distribution of different genetic variants of E. chaffeensis and the genetic polymorphism of the VLPT gene. Further study with a relatively larger sample size from a wider geographical area might be able to detect such a pattern. / Department of Physiology and Health Science

Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / Department of Physiology and Health Science

Das akute Lungenversagen (Adult Respiratory Distress Syndrome: ARDS) stellt ein in der Intensivmedizin häufig auftretendes Krankheitsbild dar und weist trotz intensiver Bemühungen nach wie vor eine hohe Letalität auf. Ein wichtiger pathophysiologischer Faktor bei der mit dem ARDS verbundenen schweren Gasaustauschstörung ist der intrapulmonale Rechts-links-Shunt mit daraus resultierender Abnahme des Oxygenierungsindex. Um therapeutisch eine Verbesserung der Oxygenierung zu erreichen, wurde unter anderem von Gallart et al. ein Konzept entwickelt, bei dem durch den kombinierten Einsatz eines intravenös gegebenen pulmonalen Vasokonstriktors (Almitrine) und eines inhalativ gegebenen pulmonalen Vasodilatators (inhalatives Stickstoffmonoxid: iNO) die Shuntfraktion verkleinert wird (Gallart et al. 1998). Im Rahmen dieser Arbeit wurde die Kombination von iNO mit der intravenösen Gabe von zellfreiem Hämoglobin (Hemoglobin Based Oxygen Carrier, HBOC) als Vasokonstriktor am Tiermodell des akuten Lungenversagens hinsichtlich hämodynamischer Parameter und der arteriellen Oxygenierung untersucht. Die Ergebnisse wurden verglichen mit einer zweiten Versuchsgruppe, in der die Tiere lediglich iNO und Hydroxyethylstärke als Kontrollsubstanz erhielten. In Pilotversuchen wurden dafür ein Tiermodell des akuten Lungenversagens etabliert und die Auswirkungen der Gabe von HBOC bei vorbestehendem Lungenschaden untersucht. Anhand der durchgeführten Versuche konnte gezeigt werden, dass sich durch die HBOC-Gabe sowohl der systemische als auch der pulmonalarterielle Blutdruck signifikant erhöhte. Durch die zusätzliche Gabe von iNO ließ sich dieser Effekt antagonisieren. Ein additiver Effekt auf die arterielle Oxygenierung durch den kombinierten Einsatz von HBOC und iNO -im Vergleich zur alleinigen Gabe von iNO- war nachweisbar, die Unterschiede waren jedoch nicht signifikant. Weitere Untersuchungen werden zeigen müssen, ob sich dieser Effekt bei größerer Fallzahl als signifikant erweist, oder ob dieser tatsächlich nicht vorhanden sein sollte.

Ingestion of contaminated chicken meat is a major cause of Campylobacteriosis in Europe and the USA. The environment, including wild birds, is considered to be an important reservoir for chicken colonization. The aims of this study were to determine the population structure of Campylobacter amongst chicken and wild bird sources on a single farm, and to establish the extent to which genotypes flow between them and ultimately infect humans, using MLST and antigen sequence typing. A pilot study amongst farm animals and wild birds in Lancashire demonstrated that Campylobacter genotypes from human disease were common on the farm and could be isolated from more than one animal source. Between 30-50% of wild geese and Starlings were shedding Campylobacter, with a seasonal peak in shedding rate in Spring. Genotypes were divergent from those previously isolated from human disease, retail meat and farm animal sources, with the majority being restricted to the host source. The carriage rate of Campylobacter was between 70- 100% amongst 78 free-range poultry flocks tested at 56 days of age. Up to seven genotypes were found to co-exist within a flock, and genotypes varied throughout the year on a random basis. Some Campylobacter strains were isolated from one farm site only, but a small percentage of them had spread nationally and were stable over a period of a decade. A total of 23% of Campylobacter isolates from free-range chickens were indistinguishable to those from human disease, and 5% were indistinguishable from wild birds. A total of 6% of genotypes isolated from wild birds were indistinguishable from those isolated from human disease. Wild birds could not be completely disregarded as a potential reservoir of Campylobacter for both humans and poultry, but their role is likely to be limited.

Glucose was present in substantially greater concentrations in whole body extracts of fourth instar Aedes aegypti L. larvae than was trehalose; in contrast, trehalose was more abundant than glucose in haemolymph extracts. Preliminary studies suggested that infection of Ae. aegypti by the entomopathogenic digenean Plagiorchis elegans Rudolphi alters the carbohydrate metabolism of fourth instar larvae. Within 24 hours of cercarial penetration, total body extracts of infected fourth instar larvae exhibited decreased trehalase activity, increased trehalose-6-phosphatase activity, and an accumulation of trehalose in comparison to uninfected larvae. Concentrations of glucose, glycogen and lipids, and the activity of glycogen phosphorylase a were similar in extracts of infected and control larvae. The predominant fatty acids, in both control and infected larvae, were C 18:0, C 18:1 and C 18:3. There were no significant differences in the types and proportions of fatty acids found in control and infected larvae. Parasitic infection is discussed in terms of impaired trehalose metabolism.

Nanofibres have been the subject of recent intensive research due to their unique properties, especially their large surface-area-to-volume ratio, which is about one thousand times higher than that of a human hair. They also have several other remarkable characteristics, such as flexibility in surface functionality, superior mechanical properties such as stiffness and tensile strength, their capacity to be formed into a variety of shapes, and the fact that they can be produced from a wide range of organic and inorganic polymers. These outstanding properties make polymer nanofibres the optimal candidates for providing significant improvement in current technology and for opening the door to novel applications in many research areas. Electrospinning is a straightforward and inexpensive process that produces continuous nanofibres from submicron diameters down to nanometre diameters. Many researchers have successfully electrospun a variety of polymer solutions into nanofibres. However, electrospinning any polymer solution directly is not straightforward or simple because of the number of parameters that influence the electrospinning process. The characteristics of the electrospun jet and the morphology of the resultant fibres are highly dependent on the properties of the polymer solution. In addition, what are favourable processing conditions for one polymer solution may not be suitable for another solution. A literature review revealed that there is no clear understanding of the behaviour of the electrospun jet and the way in which fibre morphology varies with variations in influential parameters. In addition, reported results contain significant inconsistencies and very little research has examined the effects of electrical parameters such as the electric field, the polarity of the electrode, and the conductivity and permittivity of the solution. Furthermore, no research has been conducted with respect to optimizing the electrospinning process. In this thesis, a comprehensive study was carried out by giving a special attention to the effects of electric field that have not been thoroughly investigated in the past. The electric field between the needle tip and the collector plate was altered by varying the applied voltage, distance between the needle tip and the collector plate, the inner diameter of the needle, and polarity of the voltage. Based on the experimental work, it was found that the behavior of Taylor cone, the length of the straight jet portion, and whipping jet region is highly influenced by the distribution of the electric field between the needle tip and the collector plate. Based on the stability of the Taylor cone, it was concluded that the stable operating region of the electrospun jet is a very narrow region and it is between 0.9 – 1.1kV/mm for the range of experiments that were carried out in this study. The length of the straight jet portion of the electrospun jet shows a linear relationship to the applied electric field at the tip of the fluid droplet and the whipping jet region is influenced by both the electric field at the tip of the fluid droplet and the distance between the needle and the collector plate. A confirmation were made that there must be enough distance between the needle tip and the collector plate (>200mm) to operate over the complete range of voltages without affecting drying of nanofibres. It was also concluded that the morphology and diameter of the collected nanofibres depend significantly on both the length of the straight jet portion and size of the whipping region. The effects of polarity of the applied voltage on the electrospinning process and nanofibre morphology were investigated using the positive, negative, and AC voltages. However, it was found that the electrospinning can not be achieved with the application of 60Hz AC voltage. It was observed that the behavior of Taylor cone, the straight jet portion, and the whipping jet region depend on the polarity of the applied voltage. During the study, it was accomplished that the reason for this different behavior is the disparity of ionization in the polymer solution with the application of positive and negative high voltages. In this thesis, the effects of multi-needle arrangements on the electrospinning process and fibre morphology were also explained. Finite element method (FEM) simulation results revealed that the local electric field strength around each needle tip weakens significantly in the case of multi-needle schemes due to the mutual influence of other needles in the arrangement compared to the single-needle system. The spacing between the needles was varied, and the effects of the needle spacing were examined. The experimental and simulation results were concealed the correlation between the degree of field distortion and the variation in the measured vertical angle of the straight jet portion for different needle spacing. It was concluded that the local field deterioration at the needle tips in multi-needle schemes degrades the electrospinning process significantly and produces considerable variation in the fibre morphology even though the influence of needle spacing on the average jet current and the fibre diameter are not very significant. In this work, the effects of conductivity and ionic carriers on the process of electrospinning and hence on the morphology of nanofibres were studied using polyethylene oxide (PEO) and polyacrylic acid (PAA) aqueous solutions. Different salts including lithium chloride (LiCl), sodium chloride (NaCl), sodium fluoride (NaF), sodium bicarbonate (NaHCO3), potassium chloride (KCl), and cesium chloride (CsCl) were added in different concentrations to the polymer solutions for introducing different ionic carriers into the solution. The results showed that the average fiber diameter decreases with increase in the conductivity of the solution. In addition, it was discovered that the formation of Taylor cone highly depends on the conductivity in the polymer solution. Formation of multi-jets at the fluid droplet when the conductivity of the polymer solution is increased during the electrospinning was also observed. These behaviors were completely explained using the distribution of the surface charge around the electrospun jet and the variation in the tangential electric field along the surface of the fluid droplet. The stretching of the polymer jet can be related to the amount of ionic carries and the size and mobility of positive and negative ions. The increasing amount of ionic carriers and smaller size positive ions enhance the stretching of the electrospun jet. In contrast, the lesser diameter negative ions decrease the stretching of the electrospun jet. The morphology of electrospun nanofibres can also be varied by altering the type of ionic carriers. A charge modifier, which is a container that is used to hold a solvent surrounding the needle tip during the electrospinning, was introduced to facilitate the electrospinning of insulating and high conductivity polymer solutions. The co-axial flow of the filled solvent on the outer surface of the polymer solution helps to induce enough surface charges during electrospinning and it also keeps the electric field tangential to the fluid surface during the process. Therefore, the introduction of charge modifier greatly enhanced the electrospinning behavior of highly insulating and conductive polymer solutions and liquids. The developed charge modifier method was verified by using sodium alginate which is a biopolymer that cannot electrospin alone due to its high electrical conductivity and silicone rubber which is an insulating liquid polymer at room temperature. One of the most commonly used theoretical model of the electrospinning process was modified to incorporate the non-uniform characteristics of the electric field at the tip of the needle. The non-uniform electric field between the needle tip (spinneret) and the collector plate was calculated based on the charge simulation technique (CST). It gives a better representation of the true electrospinning environment compared to the uniform field calculation in the existing model. In addition, a localized approximation was used to calculate the bending electric force acting on the electrospinning jet segments. It was also introduced a constant velocity to initiate the electrospinning jet during simulation. The incorporated modifications gave better results that closely match with the real electrospinning jet. The modified electrospinning model was used to understand the effects of parameters on the electrospinning process and fibre morphology.

No description available.