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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

EXAMINATION OF THE <em>SNSAG</em> SURFACE ANTIGEN GENE FAMILY IN <em>SARCOCYSTIS NEURONA</em>

Gautam, Ablesh 01 January 2014 (has links)
Sarcocystis neurona is a protozoan parasite that causes the serious neurologic disease equine protozoal myeloencephalitis (EPM). The life cycle of S. neurona progresses through multiple developmental stages that differ morphologically and molecularly. The S. neurona merozoite surface is covered by multiple related proteins, which are orthologous to the surface antigen (SAG) gene family of Toxoplasma gondii. The SAG surface antigens in T. gondii and another related parasite Neospora caninum are life cycle stage-specific and seem necessary for parasite transmission and persistence of infection. The present research was conducted to explore the gene family of SnSAGs in S. neurona. Specifically, the project identified new SnSAGs in the draft genome sequence of S. neurona and examined the stage-specific expression and potential function of these surface antigens. For the first part of the study, expression of the S. neurona merozoite surface antigens was evaluated in the sporozoite and bradyzoite stages. The studies revealed that SnSAG2, SnSAG3 and SnSAG4 are expressed by sporozoites, while SnSAG5 appeared to be downregulated in this life cycle stage. In S. neurona bradyzoites, SnSAG2, SnSAG3, SnSAG4 and SnSAG5 were either absent or expression was greatly reduced. For the second part of the study, the draft sequence of the S. neurona genome was searched for potential new SnSAGs. Multiple searches revealed sixteen potential new SnSAG genes, and bioinformatic analyses of the sequences revealed characteristics consistent with the SAG gene family. Two of the new SnSAGs, designated SnSAG7 and SnSAG8, have been characterized in detail. The studies showed that SnSAG7 is expressed by the merozoite stage, while SnSAG8 is expressed by the bradyzoite stage. The third part of the study assessed the role of SnSAGs in host cell attachment and/or invasion by S. neurona. Serum neutralization assays using polyclonal serum raised against SnSAG1, SnSAG2, SnSAG3, and SnSAG4 suggested that SnSAG1 and SnSAG4 play a role in host cell attachment and/or invasion; treatment with antibodies against SnSAG2 and SnSAG3 were inconclusive. The information acquired about the stage-specific expression of the SnSAGs, identification of new SnSAG paralogues, and their functional characterization will help to understand the importance of the SnSAG proteins for parasite survival and could lead to improved methods for EPM prevention and/or treatment.
412

The ecology of Arctic cod (Boreogadus saida) and interactions with seabirds, seals, and whales in the Canadian Arctic

Matley, Jordan January 2012 (has links)
This thesis investigates the foraging of Arctic cod (Boreogadus saida) and its predators during the summer in the Canadian Arctic. Findings included the identification of Arctic cod, ringed seal (Pusa hispida), beluga (Delphinapterus leucas), and narwhal (Monodon monoceros) diet shifts in response to seasonal prey availability; calculation of isotopic diet-tissue discrimination factors for Arctic cod, ringed seals, and whales based on local tissue and stomach content sampling; and determination of predatory cues to optimize foraging, such as the presence of schools. Additionally, I quantified seabird feeding and interspecific interactions such kleptoparasitism and found that black-legged kittiwakes (Rissa tridactyla) and northern fulmars (Fulmarus glacialis) captured cod directly but lost many to parasitic jaegers (Stercorarius parasiticus) and glaucous gulls (Larus hyperboreus). Finally, I determined that schools of cod were important prey sources for northern fulmars, glaucous gulls, and whales however non-schooling cod were a significant source for black-legged kittiwakes and ringed seals.
413

Aspectos ecológicos, biológicos e de resistência de Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) na região de Jaboticabal, São Paulo, Brasil / Ecological, biological and resistance aspects of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) in the region of Jaboticabal, state of São Paulo, Brazil

Cruz, Breno Cayeiro 27 October 2017 (has links)
Submitted by BRENO CAYEIRO CRUZ null (breno.c.cruz@hotmail.com) on 2017-12-04T11:58:38Z No. of bitstreams: 1 - TESE -.pdf: 3422888 bytes, checksum: a396717b2b2074de76c0871a37c4eebb (MD5) / Submitted by BRENO CAYEIRO CRUZ null (breno.c.cruz@hotmail.com) on 2017-12-04T14:43:23Z No. of bitstreams: 1 - TESE -.pdf: 3422888 bytes, checksum: a396717b2b2074de76c0871a37c4eebb (MD5) / Submitted by BRENO CAYEIRO CRUZ null (breno.c.cruz@hotmail.com) on 2017-12-05T14:11:14Z No. of bitstreams: 1 - TESE -.pdf: 3422888 bytes, checksum: a396717b2b2074de76c0871a37c4eebb (MD5) / Submitted by BRENO CAYEIRO CRUZ null (breno.c.cruz@hotmail.com) on 2017-12-11T18:47:11Z No. of bitstreams: 1 - TESE -.pdf: 3422888 bytes, checksum: a396717b2b2074de76c0871a37c4eebb (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2017-12-13T11:26:46Z (GMT) No. of bitstreams: 1 cruz_bc_dr_jabo.pdf.pdf: 3422888 bytes, checksum: a396717b2b2074de76c0871a37c4eebb (MD5) / Made available in DSpace on 2017-12-13T11:26:46Z (GMT). No. of bitstreams: 1 cruz_bc_dr_jabo.pdf.pdf: 3422888 bytes, checksum: a396717b2b2074de76c0871a37c4eebb (MD5) Previous issue date: 2017-10-27 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Rhipicephalus (Boophilus) microplus (Canestrini, 1888) é o mais importante ectoparasito da pecuária brasileira, cujo controle exige conhecimentos comportamentais de seu ciclo biológico para melhor sucesso na atuação sobre e fora do hospedeiro, combatendo-o em épocas do ano desfavoráveis ao mesmo. A maioria das informações sobre sua biologia e ecologia foi originada em outros países ou então há muito tempo. Baseado nas mudanças climáticas recentes e ausência de informações sobre ecologia e biologia deste ixodídeo na região, este estudo, conduzido em bioma de Cerrado e clima tropical com estação seca (Aw), obteve tais dados pela observação, ao longo de dois anos, dos fatores envolvidos nas suas fases de vida parasitária e não parasitária, além de avaliar o comportamento desta cepa quanto à evolução do perfil de resistência/susceptibilidade aos acaricidas. Observando a fase de vida parasitária deste carrapato, foi possível perceber sua adaptação às mudanças climáticas, com cinco gerações anuais registradas em dois anos consecutivos pela primeira vez na literatura. Constatou-se que não houve correlações significativas entre seu ciclo parasitando bovinos e os níveis de chuva, temperaturas ambiental e ao nível do solo e umidade relativa do ar. Já a fase de vida livre foi influenciada pelos fatores climáticos, com correlação positiva entre pluviosidade/pré-postura, correlações negativas entre temperatura/pré-postura, incubação e pré-eclosão, entre umidade relativa do ar/incubação e pré-eclosão. Os dados obtidos indicaram que o período de seca (outono e inverno) é mais favorável à manutenção do carrapato bovino no ambiente, além de albergar as maiores cargas parasitárias nos hospedeiros. A dinâmica populacional calculada reforça a adaptação deste ixodídeo às mudanças climáticas, culminando na existência de 5,212 gerações anuais mesmo em condições climáticas e ambientais distintas, oscilando entre 2,6 e 8,3 gerações/ano. Considerando estes dados, foi proposta uma metodologia de controle estratégico específica, tratando os animais entre a segunda metade da primavera e a primeira metade do verão (outubro a fevereiro). Estes tratamentos na estação chuvosa levariam a populações menores na estação seca, reduzindo também o “spring rise”. A análise da eficácia de diferentes compostos químicos por meio do Teste de Pacote de Larvas gerou resultados contraditórios, com alta eficácia registrada para piretróides e organofosforados, e oscilações na eficácia do amitraz. Estes valores levantaram questionamentos sobre a aplicabilidade desta técnica no monitoramento da resistência. Futuros estudos devem ser propostos, analisando a real eficácia dos Testes de Pacote de Larvas, confrontando diferentes metodologias in vivo e in vitro; comparando a dinâmica populacional deste ixodídeo em diferentes pastagens, formas de manejo, taxas de lotação, altitudes e biomas; atestando a eficácia da metodologia de controle estratégico proposta e, principalmente, confirmando a possibilidade de observarem-se mais de oito gerações de R. microplus por ano em condições climáticas ideais. / Rhipicephalus (Boophilus) microplus (Canestrini, 1888) is the main ectoparasite in Brazilian cattle industry, and its control demands behavioral knowledge of its biologic cycle, for increased success in actions over and out of the hosts, with treatments in periods of the year less favorable to this tick. Most of the information about its biology and ecology was originated in other countries or a long time ago. Based in recent climate changes and absence of ecologic and biologic data on this region, the present study, conducted in the Brazilian “Cerrado” biome and tropical savanna climate (Aw), obtained such data through the observation, during two consecutive years, of factors involved on parasitic and free living phases of its cycle, also evaluating the behavior of this strain regarding evolution of its resistance/susceptibility profile against acaricides. Observing the parasitic phase of the Southern Cattle Tick, it was possible to detect adaptations of this ixodid to climate changes, with five annual generations in two consecutive years being registered for the first time in literature, without significant correlations between its period parasitizing bovines and rain levels, environmental and soil level temperatures and relative air humidity. The free living period of its cycle was affected by climatic variables, with positive correlation between rainfall and the period before oviposition, and negative correlations between temperatures and the period before oviposition, egg incubation and period before hatching, and between relative air humidity and egg incubation and the period before larval hatching. Obtained data indicate that the dry season (autumn and winter) is more favorable for maintenance of the Southern Cattle Tick on the environment, as well as presenting highest parasitic burdens in hosts. Population dynamics calculated reinforces the adaptations of such ixodid to climate changes, leading to the existence of 5.212 yearly generations even in distinct climatic and environmental conditions, varying between 2.6 and 8.3 generations per year. Considering such data, a specific strategic control methodology was proposed, treating animals between the second half of spring and the first half of summer (October to February). Such treatments in rainy seasons would lead to smaller populations on the dry season, also reducing the “spring rise”. Analysis of efficacy of different chemical compounds using the Larval Packet Test generated contrasting results, with high efficacy indexes registered for pyrethroids and organophosphates, with variations in amitraz efficiency. Such values lead to a questioning of the applicability of such technique in monitoring resistance. Future studies must be proposed, analyzing the real efficacy of Larval Packet Tests, confronting different in vivo and in vitro methodologies; comparing population dynamics of such ixodid in different pastures, husbandry methods, stocking rates, altitudes and biomes; confirming the efficacy of the proposed strategic control method and, above all, confirming the possibility of observing more than eight R. microplus yearly generations in ideal climatic conditions. / 2014/14820-2
414

Relação da expressão do tlr-2, da enzima iNOS, das citocinas IL-10, TNF-α e TGF-β com a carga parasitária da pele de cães naturalmente acometidos por leishmaniose visceral: Dandara Camila Morais Pereira. -

Pereira, Dandara Camila Morais [UNESP] 13 August 2015 (has links) (PDF)
Made available in DSpace on 2016-05-17T16:51:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-08-13. Added 1 bitstream(s) on 2016-05-17T16:54:16Z : No. of bitstreams: 1 000864272_20160704.pdf: 706780 bytes, checksum: 4d6888c37d677fae1dd7bf418a013985 (MD5) Bitstreams deleted on 2016-07-25T13:17:41Z: 000864272_20160704.pdf,. Added 1 bitstream(s) on 2016-07-25T13:18:48Z : No. of bitstreams: 1 000864272.pdf: 941126 bytes, checksum: 0602961cda7c25695afee5dc324562ba (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The progression of the canine visceral leishmaniasis (CVL) is related to the immune response profile. The effective cellular immunity is related to the predominance of Th1 cytokines such as TNF-α and the disease is related to an exacerbated humoral immune response, with the predominance of Th2 cytokines such as IL-10 and TGF-β. TLR-2 is an important receptor of the innate immunity involved in the induction of the cytokines production and the activation of iNOS in visceral leishmaniasis. To understand how the skin may become a permissive microenvironment for the multiplication of this parasite, the expression of genes encoding to TLR-2, to the iNOS enzyme and to the cytokines IL-10, TNF-α and TGF-β was evaluated in skin of dogs naturally affected by CVL and were then was related to the parasite load of this tissue. We observed that the skin of dogs naturally affected by visceral leishmaniasis has a mixed Th1/Th2 immune response profile, with an increased expression of TLR-2, IL-10 and TNF-α that correlates to the increasing of the parasitic load in this tissue, giving these mediators an important role in the pathogenesis of CVL
415

An evaluation of UK sheep farmers' attitudes and behaviours towards sustainable roundworm control

Jack, Corin Malcolm January 2018 (has links)
One of the major constraints limiting the efficiency of sheep production is the control of gastrointestinal nematode parasites. Parasite control by strategic use of anthelmintics is threatened by the emergence of nematode populations that are resistant to the drugs available. It is therefore increasingly apparent that steps toward maintaining sustainable productivity in the growing face of anthelmintic resistance (AR) is required by farmers. To facilitate the uptake of sustainable approaches to parasite management, a comprehensive understanding of the various factors that may influence farmers’ decision-making processes is required. In order to establish which factors are influential, and determine their impact on farmers’ roundworm control behaviours, both qualitative and quantitative research methods were used including focus groups as well as attitudinal and behavioural questionnaires. A retrospective analysis was initially conducted of historical surveys designed to identify farm specific characteristics and parasite management practices including anthelmintic usage. The objectives of the analysis were to identify factors associated with uptake of best practice advice including farm characteristics and information sourcing. In addition, the implementation of sustainable roundworm control practices was investigated using two surveys conducted in 2000 and 2010. Logistic regression models were applied for univariable and multivariable analysis of dependent and independent variables. The next step was to conduct a series of focus groups in different geographic regions of Scotland. The main purposes were to explore sheep farmers’ attitudes towards different aspects of roundworm management, as well as to identify potential motivators and barriers to uptake of sustainable parasite control practices. The findings aided in the development of an attitudinal questionnaire used to canvass opinions representative on a national level. The concluding study involved a telephone survey of 400 Scottish sheep farmers, designed to elicit attitudes regarding roundworm control, AR and sustainable roundworm control practices. A quantitative statistical analysis technique (Structural Equation Modelling) was then used to test the relationships between socio-psychological factors and the uptake of sustainable roundworm control practices. The analysis of historical questionnaire data demonstrated evidence of a shift towards the use of practices to reduce the rate of AR development, most notably a decline in the practice of ‘dose and move’ as well as an overall reduction in treatment frequency. Statistical analysis identified significant associations between farm characteristics and specific treatment strategies. For example, larger farms were more likely to adopt a set treatment regimen (P=0.036), compared with smaller farms, which were more likely to treat based on clinical signs of infection (P=0.021). Sourcing of roundworm control information primarily from veterinarians was most associated with treatment timings with no parallels between time points. From the qualitative focus group studies conducted we identified four overarching themes impacting on sheep producers’ attitudes to roundworm control and best practice advice. These themes comprised: a lack of perceived need to change, the complexity of advice, the ease of implementation of recommended practices and the effectiveness of extension approaches. Additionally, the most important and implementable guidelines identified by sheep farmers were: ‘working out a roundworm control strategy with an advisor’ and ‘administering anthelmintics effectively’ with regard to correct drenching practice i.e. appropriate dosing, administration and drug storage procedures. These findings exhibited similarities with veterinarians’ rankings with also, ‘testing for AR’, ‘preserving susceptible parasites’ and ‘reducing dependence on anthelmintics’ receiving the lowest rankings for importance and implementability. The quantitative analysis from the attitudinal/behavioural questionnaire identified eleven factors with significant influences on the adoption of sustainable roundworm control practices. The key influences on overall adoption were farmers’ baseline understanding about roundworm control and self-reported confirmation of anthelmintic resistance in their flock. Additional positive influences included, positive attitudes to veterinary services, enterprise type and perceived risk of AR. Factors that were shown to have the greatest relative effects on individual parasite control practices included; the perceived resource requirements for implementing a quarantine strategy, farmers’ AR suspicions for instigating AR testing and the confirmation of AR for adopting faecal egg count monitoring. The findings have highlighted several factors which can influence sheep farmers’ decisions to reject or adopt recommended roundworm control practices. It is evident that the perceived complexity, lack of need and practicality of the current recommendations necessitates changes to how extension is designed and disseminated to farmers. The findings also suggest that improving farmers’ acceptance and uptake of diagnostic testing and improving underlying knowledge and awareness about nematode control is a significant target to influencing adoption of best practice behaviours. The importance of veterinarians as highly-trusted information resources validates the need for further engagement with veterinarians concerning sustainable parasite control approaches, to facilitate collaboration with farmers. The need for interaction between farmers and their advisors is key to resolving the issues raised to enable the necessary explanation, justification and execution of recommended practices to suit farmers’ needs and farming conditions.
416

Antiresonance and Noise Suppression Techniques for Digital Power Distribution Networks

Davis, Anto K January 2015 (has links) (PDF)
Power distribution network (PDN) design was a non-existent entity during the early days of microprocessors due to the low frequency of operation. Once the switching frequencies of the microprocessors started moving towards and beyond MHz regions, the parasitic inductance of the PCB tracks and planes started playing an important role in determining the maximum voltage on a PDN. Voltage regulator module (VRM) sup-plies only the DC power for microprocessors. When the MOSFETs inside a processor switches, it consumes currents during transition time. If this current is not provided, the voltage on the supply rails can go below the specifications of the processor. For lower MHz processors few ceramic-capacitors known as ‘decoupling capacitors’ were connected between power and ground to provide this transient current demand. When the processor frequency increased beyond MHz, the number of capacitors also increased from few numbers to hundreds of them. Nowadays, the PDN is said to be comprising all components from VRM till the die location. It includes VRM, bulk capacitors, PCB power planes, capacitor mounting pads and vias, mount for the electronic package, package capacitors, die mount and internal die capacitance. So, the PDN has evolved into a very complex system over the years. A PDN should provide three distinct roles; 1) provide transient current required by the processor 2) act as a stable reference voltage for processor 3) filter out the noise currents injected by the processor. The first two are required for the correct operation of the processor. Third one is a requirement from analog or other sensitive circuits connected to the same PDN. If the noise exits the printed circuit board (PCB), it can result in conducted and radiated EMI, which can in turn result in failure of a product in EMC testing. Every PDN design starts with the calculation of a target impedance which is given as the ratio of maximum allowed ripple voltage to the maximum transient current required by the processor. The transient current is usually taken as half the average input current. The definition of target impedance assumes that the PDN is flat over the entire frequency of operation, which is true only for a resistive network. This is seldom true for a practical PDN, since it contains inductances and capacitances. Because of this, a practical PDN has an uneven impedance versus frequency envelope. Whenever two capacitors with different self resonant frequencies are connected in parallel, their equivalent impedance produces a pole between the self resonant frequencies known as antiresonance peaks. Because of this, a PDN will have phase angles associated with them. Also, these antiresonance peaks are energy reservoirs which will be excited during the normal operation of a processor by the varying currents. The transient current of a microprocessor is modeled as a gamma function, but for practical cases it can be approximated as triangular waveforms during the transition time which is normally 10% of the time period. Depending upon the micro-operations running inside the processor, the peak value of this waveform varies. This is filtered by the on-chip capacitors, package inductance and package capacitors. Due to power gating, clock gating, IO operations, matrix multiplications and magnetic memory readings the waveforms at the board will be like pulse type, and their widths are determined by these operations. In literatures, these two types of waveforms are used for PDN analysis, depending upon at which point the study is conducted. Chapter 1 introduces the need for PDN design and the main roles of a PDN. The issue of antiresonance is introduced from a PDN perspective. Different types of capacitors used on a PDN are discussed with their strengths and limitations. The general nature of the switching noise injected by a microprocessor is also discussed. This chapter discusses the thesis contributions, and the existing work related to the field. Chapter 2 introduces a new method to calculate the target impedance (Zt ) by including the phase angles of a PDN which is based on a maximum voltage calculation. This new Zt equals to conventional Zt for symmetrical triangular switching current waveforms. The value of new Zt is less than the conventional Zt for trapezoidal excitation patterns. By adding the resonance effects into this, a maximum voltage value is obtained in this chapter. The new method includes the maximum voltage produced on a PDN when multiple antiresonance peaks are present. Example simulations are provided for triangular and pulse type excitations. A measured input current wave-form for PIC16F677 microcontroller driving eight IO ports is provided to prove the assumption of pulse type waveforms. For triangular excitation waveform, the maximum voltage predicted based on the expression was ¡0.6153 V, and the simulated maximum voltage was found to be at ¡0.5412 V which is less than the predicted value. But the predicted value based on Zt method was 1.9845 V. This shows that the conventional as well as the new target impedance method leads to over estimating the maximum voltage in certain cases. This is because most of the harmonics are falling on the minimum impedance values on a PDN. If the PDN envelope is changed by temperature and component tolerances, the maximum voltage can vary. So the best option is to design with the target impedance method. When pulse current excitation was studied for a particular PDN, the maximum voltage produced was -139.39 mV. The target impedance method produced a value of -100.24 mV. The maximum voltage predicted by the equation was -237 mV. So this shows that some times the conventional target impedance method leads to under estimating the PDN voltage. From the studies, it is shown that the time domain analysis is as important as frequency domain analysis. Another important observation is that the antiresonance peaks on a PDN should be damped both in number and peak value. Chapter 3 studies the antiresonance peak suppression methods for general cases. As discussed earlier, the antiresonance peaks are produced when two capacitors with different self resonant frequencies are connected in parallel. This chapter studies the effect of magnetic coupling between the mounting loops of two capacitors in parallel. The mounting loop area contribute to the parasitic inductance of a capacitor, and it is the major contributing factor to it. Other contributing factors are equivalent series inductance (ESL) and plane spreading inductance. The ESL depends on the size and on how the internal plates of the capacitors are formed. The spreading inductance is the inductance contributed by the parts of the planes connecting the capacitor connector vias to the die connections or to other capacitor vias. If the power and ground planes are closer, the spreading inductance is lower. On one/two layer boards dedicated power/ground planes are absent. So the spreading inductance is replaced by PCB track inductances. The inductance contributed by the mounted area of the capacitor is known as mounting inductance. On one/two layer boards dedicated power/ground planes are absent. So the spreading inductance is replaced by PCB track inductances. The dependencies of various circuit parameters on antiresonance peak are studied using circuit theory. A general condition for damping the antiresonance is formulated. The antiresonance peak reduces with Q factor. The conventional critical condition for antiresonance peak damping needs modification when magnetic coupling is present between the mounting loops of two parallel unequal value capacitors. By varying the connection geometry it is possible to obtain negative and positive coupling coefficients. The connection geometries to obtain these two are shown. An example is shown for positive and negative coupling coefficient cases with simulation and experimental results. For the example discussed, RC Æ 32 - for k Æ Å0.6 and RC Æ 64 - for k Æ ¡0.6, where RC is the critical damping value and k is the magnetic coupling coefficient between the two mounting loops. The reason for this is that, the antiresonance peak impedance value is higher for negative coupling coefficient case than that for positive coupling coefficient case. Above the self resonant frequencies of both the capacitors, the equivalent impedance of the parallel capacitors become inductive. This case is studied with two equal value capacitors in parallel. It is shown that the equivalent inductance is lower for negative coupling coefficient case as compared to positive coupling coefficient case. An example is provided with simulation and experimental results. In the experimental results, parasitic inductance is observed to be 2.6 times lower for negative coupling coefficient case than that for positive coupling coefficient case. When equal value capacitors are connected in parallel, it is advantageous to use a negative coupling geometry due to this. Chapter 4 introduces a new method to damp the antiresonance peak using a magnet-ically coupled resistive loop. Reducing the Q factor is an option to suppress the peak. In this new method, the Q factor reduction is achieved by introducing losses by mag-netically coupling a resistive loop. The proposed circuit is analyzed with circuit-theory, and governing equations are obtained. The optimum value of resistance for achieving maximum damping is obtained through analysis. Simulation and experimental results are shown to validate the theory. From the experimental results approximately 247 times reduction in antiresonance peak is observed with the proposed method. Effectiveness of the new method is limited by the magnetic coupling coefficient between the two mounting loops of capacitors. The method can be further improved if the coupling coefficient can be increased at the antiresonance frequency. Chapter 5 focuses on the third objective of a PDN, that is to reduce the noise injected by the microprocessor. A new method is proposed to reduce the conducted noise from a microprocessor with switched super capacitors. The conventional switched capacitor filters are based on the concept that the flying capacitor switching at high frequency looks like a resistor at low frequency. So for using at audio frequencies the flying capacitors were switching at MHz frequencies. In this chapter the opposite of this scenario is studied; the flying capacitors are the energy storage elements of a switched capacitor converter and they switch at lower frequencies as compared to the noise frequencies. Two basic circuits (1:1 voltage conversion ratio) providing noise isolation were discussed. They have distinct steady state input current waveforms and are explained with PSPICE simulations. The inrush current through switches are capable of destroying them in a practical implementation. A practical solution was proposed using PMOS-PNP pair. The self introduced switching noise of the converter is lower when switching frequency is low and turn ON-OFF time is higher. If power metal oxide semiconductor field effect transistor (MOSFET)s are used, the turn ON and turn OFF are slow. The switching frequency can be lowered based on the voltage drop power loss. The governing equations were formulated and simulated. It is found that the switching frequency can be lowered by increasing the capacitance value without affecting the voltage drop and power loss. From the equations, it is found that the design parameters have a cyclic dependency. Noise can short through the parasitic capacitance of the switches. Two circuits were proposed to improve the noise isolation: 1) T switch 2) ¦ switch. Of these, the ¦ switch has the higher measured transfer impedance. Experimental results showed a noise reduction of (40-20) dB for the conducted frequency range of 150 kHz - 30 MHz with the proposed 1:1 switched capacitor converter. One possible improvement of this method is to combine the noise isolation with an existing switched capacitor converter (SCC) topology. The discussed example had a switching frequency of 700 Hz, and it is shown that this can isolate the switching noise in kHz and MHz regions. In a PDN there are antiresonance peaks in kHz regions. If the proposed circuit is kept close to a microprocessor, it can reduce the excitation currents of these low frequency antiresonance peaks. Chapter 6 concludes the thesis by stating the major contributions and applications of the concepts introduced in the thesis. This chapter also discusses the future scope of these concepts.
417

Helmintofauna monogenética e as táticas reprodutivas da biquara Haemulon plumierii (Lacepède, 1802) / Helmintofauna monogenétic and the reproductive tactics of white grunt Haemulon plumierii (Lacepède, 1802)

Fernandes, Bruna Laura de França 21 February 2017 (has links)
Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-06-29T12:11:05Z No. of bitstreams: 1 BrunaLFF_DISSERT.pdf: 1489360 bytes, checksum: b80c12e94b27433d39f8e4d7c7b1d47e (MD5) / Made available in DSpace on 2017-06-29T12:11:06Z (GMT). No. of bitstreams: 1 BrunaLFF_DISSERT.pdf: 1489360 bytes, checksum: b80c12e94b27433d39f8e4d7c7b1d47e (MD5) Previous issue date: 2017-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Haemulon plumierii are coastal fish that inhabit waters from the Chesapeake Bay - US, Gulf of Mexico, Caribbean and the entire coast of Brazil. Fish are the aquatic vertebrates that have the highest rates of parasitism and use different reproductive tactics in their life strategy to maximize reproduction and ensure the survival of their offspring to adulthood. The present work verified whether the ectoparasitism by monogenetic can influence the reproductive tactics of H. plumierii in marine waters in the North Atlantic Ocean Southwest (4º 50'57 ''S and 37º51'36''O), near the Rio Grande do Norte / Brazil, for that, the parasitic research of monogenetic was carried out and the study of the reproductive tactics of H. Plumierii. 240 copies were captured of H. plumierii hosts in the period from august 2015 to july 2016, with amplitudes of total weight between 84.5 to 517.5g and total length of 175 to 315mm. Monogenetics parasitized 106 H. plumierii fish among 240 examined, and 162 parasites were collected that were distributed in two subclasses: Monopisthocotylea and Polyopisthocotylea. Monopisthocotylea of the family Capsalidae in the genus Encotyllabe (75 in the gills and 9 in the skin) and Entobdella (1 in the gills and 17 in the skin); Polyopisthocotylea in the family Diclidophoridae in the genus Choricotyle (51 in the gills and 9 in the skin). H. plumierii was identified as a new host for the monogenéticos Encotyllabe sp., Entobdella hipoglossi, and Choricotyle sp., being the first record of the genus Entobdella in the family Haemulidae. The monogenetic parasites had a higher parasite preference for the gills, presenting low parasitic ecological indices. It was determined that H. plumierii are seasonal strategist fish in which males present greater total weight, total length and number in relation to females, however, there were no significant differences. It was recorded that the H. plumierii species has the following reproductive tactics: growth of the negative allometric type indicating a greater body increase in length than in weight; independent of this immature (young) stage it was verified macroscopically that adults have three stages of gonadal development (in maturation, mature and emptied) during the reproductive cycle; this animal altered its reproductive strategy, initiating reproductive development with precocity where the absolute fecundity was 52,123 oocytes with a synchronous spawning type in more than two groups; the reproductive period is comprised throughout the year with the highest occurrence in two moments in the months of march to june and the second of august to October. The present work reported that the species Haemulon plumierii is parasitized by monogenetic Monopisthocotylea and Polyopisthocotylea with low prevalence rates, medium intensity and average abundance, and that H. plumierii is a seasonal strategist where his reproductive tactics were not influenced by the parasitism of monogenetics in conditions of low parasitic ecological indices / Haemulon plumierii são peixes costeiros que habitam águas desde a Baía de Chesapeake - EUA, Golfo do México, Caribe e toda a costa do Brasil. Os peixes são os vertebrados aquáticos que apresentam os maiores índices de parasitismo e usam diferentes táticas reprodutivas em sua estratégia de vida para maximizar a reprodução e garantir a sobrevivência dos seus descendentes até a idade adulta. O presente trabalho verificou se o ectoparasitismo por monogenéticos pode influenciar as táticas reprodutivas de H. plumierii nas águas marinhas no Norte do Oceano Atlântico Sudoeste (4º 50’57’’S e 37º51’36’’O), próximo ao Rio Grande do Norte/Brasil, para isso, realizou-se a pesquisa parasitária de monogenéticos e o estudo das táticas reprodutivas de H. plumierii. Foram capturados 240 exemplares de hospedeiros H. plumierii no período de agosto de 2015 a julho de 2016, com amplitudes de peso total entre 84,5 a 517,5g e comprimento total de 175 a 315mm. Os Monogenéticos parasitaram 106 peixes H. plumierii entre 240 examinados, sendo coletados 162 parasitos que estavam distribuídos em duas subclasses: Monopisthocotylea e Polyopisthocotylea. Monopisthocotylea da família Capsalidae nos gêneros Encotyllabe (75 nas brânquias e 9 no tegumento) e Entobdella (1 nas brânquias e 17 no tegumento); Polyopisthocotylea na família Diclidophoridae no gênero Choricotyle (51 nas brânquias e 9 no tegumento). H. plumierii foi identificado como um novo hospedeiro para os monogenéticos Encotyllabe sp., Entobdella hipoglossi, e Choricotyle sp., sendo o primeiro registro do gênero Entobdella na família Haemulidae. Os parasitos monogenéticos apresentaram uma maior preferência parasitária pelas brânquias, apresentando baixos índices ecológicos parasitários. Determinou-se que H. plumierii são peixes estrategistas sazonais no qual os machos apresentam maior peso total, comprimento total e número em relação as fêmeas, contudo não ocorreram diferenças significativas. Registrou-se que a espécie H. plumierii possui as seguintes táticas reprodutivas: crescimento do tipo alométrico negativo indicando um incremento corporal maior em comprimento do que em peso; independente deste estádio imaturo (jovens) foi verificado macroscopicamente que os adultos possuem três estádios de desenvolvimento gonadal (em maturação, maduro e esvaziado) durante o ciclo reprodutivo; este animal alterou sua estratégia reprodutiva iniciando o desenvolvimento reprodutivo com precocidade onde a fecundidade absoluta foi de 52.123 ovócitos com um tipo de desova sincrônico em mais de dois grupos; o período reprodutivo está compreendido durante todo o ano com maior ocorrência em dois momentos nos meses de março a junho e o segundo de agosto a outubro. O presente trabalho registrou que a espécie Haemulon plumierii é parasitado por monogenéticos Monopisthocotylea e Polyopisthocotylea com baixos índices de prevalência, intensidade média e abundância média, e que H. plumierii é um estrategista sazonal onde suas táticas reprodutivas não sofreram influência pelo parasitismo de monogenéticos nas condições de baixos índices ecológicos parasitários / 2017-06-29
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Monitoring a regulace parazitického roztoče Varroa destructor v chovech včely medonosné (Apis mellifera

KLEČKOVÁ, Romana January 2018 (has links)
The aim of this thesis was to monitor the Varroa destructor parasitic mite in correlation with the microclimatic conditions of the Carniolan honey bee (Apis mellifera carnica). The rate of infestation of selected bee colonies at different locations was assessed in three-day intervals. At the same time, the microclimate in the hives was observed. The monitoring took place from April to mid-October. Also, the effect of the microclimate on the mite fall count was evaluated. During the whole evaluation, the highest average daily fall count was 2.08 mites per day at honeybee colonies at location 1 and 2; 1.97 at location 3. There was no statistically significant difference (P > 0.05) between those locations. The comparison of fall count between the moths of observation revealed, that highest fall count was during September (3.03 mites per day) and the lowest fall count was in April (0.41 mites per day; P 0.001). The rates of dependence (assessed by correlation analysis) between the fall count and microclimatic conditions in individual colonies varied. The strongest correlation between hive temperature and fall count (r = -0.45, P 0.05) was found at location 2. A low correlation was found at location 1 (r = -0.17, P 0.05). On the other hand, location 3 showed an insignificant and inconclusive correlation between hive temperature and fall count (r = 0.003, P > 0.05). The aggregate data (without distinction of location or month) showed significant (P 0.05) correlation between fall count and hive temperature (r = -0.14). The correlation between relative air humidity in hive and the fall count was statistically insignificant and low (r = -0.02, P > 0.05). The results revealed that the degree of correlation between the hive microclimate and the development (fall count respectively) of the Varroa destructor population is different for each colony. The monitoring of the dead Varroa destructor females is an appropriate complementary tool to diagnose a colony's infestation. The statistical analysis confirmed that with the decreasing summer and end-of-summer temperatures the Varroa destructor population grows and it is necessary to take measures to suppress its growth due to the development of the honey bee long-term winter generation.
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Obtenção de membranas de hidrógeis para tratamento alternativo da Leishmaniose tegumentar / Obtaining membranes for alternative treatment hydrogeis of cutaneous Leishmaniasis

OLIVEIRA, MARIA J.A. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:41:20Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:03Z (GMT). No. of bitstreams: 0 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP / FAPESP:09/50926-1
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Relação da expressão do tlr-2, da enzima iNOS, das citocinas IL-10, TNF-α e TGF-β com a carga parasitária da pele de cães naturalmente acometidos por leishmaniose visceral / Dandara Camila Morais Pereira. -

Pereira, Dandara Camila Morais. January 2015 (has links)
Orientador:Caris Maroni Nunes / Co-orientador:Valéria Marçal Félix de Lima / Banca:Gisele Fabrino Machado / Banca:Marcia Dalastra Laurenti / Resumo:A progressão da leishmaniose visceral canina (LVC) depende do perfil da resposta imune, sendo que a imunidade celular efetiva está relacionada à predominância de citocinas Th1, como o TNF-α, e o desenvolvimento da doença está mais relacionado à resposta imune humoral exacerbada, com predominância de citocinas Th2, como a IL-10 e o TGF-β. O TLR-2, por sua vez, é um receptor da imunidade inata que tem importante papel na leishmaniose visceral por participar na indução da produção de citocinas e ativação da iNOS. Para entender como a pele pode se tornar um microambiente permissivo à multiplicação do parasita, a expressão dos genes que codificam o TLR-2, a enzima iNOS e as citocinas IL-10, TNF-α e TGF-β foi avaliada na pele de cães naturalmente acometidos por LVC e relacionada à carga parasitária deste tecido, em comparação a cães não infectados. Observou-se que a pele de cães naturalmente acometidos por leishmaniose visceral apresenta perfil misto Th1/Th2 de resposta imune, com aumento da expressão do TLR-2, da IL-10 e do TNF-α, aumento este que se correlaciona com o aumento da carga parasitária neste tecido, atribuindo a estes mediadores um papel importante na patogênese da LVC / Abstract:The progression of the canine visceral leishmaniasis (CVL) is related to the immune response profile. The effective cellular immunity is related to the predominance of Th1 cytokines such as TNF-α and the disease is related to an exacerbated humoral immune response, with the predominance of Th2 cytokines such as IL-10 and TGF-β. TLR-2 is an important receptor of the innate immunity involved in the induction of the cytokines production and the activation of iNOS in visceral leishmaniasis. To understand how the skin may become a permissive microenvironment for the multiplication of this parasite, the expression of genes encoding to TLR-2, to the iNOS enzyme and to the cytokines IL-10, TNF-α and TGF-β was evaluated in skin of dogs naturally affected by CVL and were then was related to the parasite load of this tissue. We observed that the skin of dogs naturally affected by visceral leishmaniasis has a mixed Th1/Th2 immune response profile, with an increased expression of TLR-2, IL-10 and TNF-α that correlates to the increasing of the parasitic load in this tissue, giving these mediators an important role in the pathogenesis of CVL / Mestre

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